Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/22/12
AREA FORECAST DISCUSSION
NWS LINCOLN IL
900 PM CST SAT JAN 21 2012
.DISCUSSION...
ISSUED 850 PM CST SAT JAN 21 2012
HIGH PRESSURE OVER THE EASTERN GREAT LAKES WILL CONTINUE TO PUSH
AWAY FROM THE AREA TONIGHT. THIS SHOULD ALLOW WINDS TO SHIFT MORE
INTO THE SOUTHEAST LATER TONIGHT AND INCREASE IN SPEED. THAT
COMBINED WITH CLOUDS MOVING BACK ACROSS THE ENTIRE FORECAST AREA
SHOULD PUT A HALT TO THE EARLY EVENING TEMP DECLINE. RUC SOUNDINGS
SHOWING THE POTENTIAL FOR SOME FREEZING DRIZZLE TOWARDS SUNDAY
MORNING WITH THE DEPTH OF THE LOW LEVEL MOISTURE INCREASING TO
BETWEEN 2500-3000 FEET...WITH DRY AIR LOCATED ABOVE. TEMPS..EXCPT
IN THE FAR NORTH WHERE THE CLOUDS HAVE NOT REACHED YET...SHOULD
BE STEADY OR SLOWLY RISE THE REST OF THE NIGHT. UPDATED EARLIER
TO ADJUST THE OVERNIGHT LOW TEMPS ACRS THE NORTH DUE TO THE LIGHT
SNOW COVER...CLEAR SKIES AND LIGHT WINDS.
QUICK LOOK AT THE NEW NAM-WRF NOT SHOWING MUCH CHANGE REGARDING THE
STORM SYSTEM FOR TOMORROW. OUR BEST CHANCE FOR STRONG TO SEVERE
THUNDERSTORMS WILL BE ALONG AND SOUTHEAST OF AN EFFINGHAM TO PARIS
LINE. STILL SEEING TREMENDOUS WIND FIELDS ASSOCIATED WITH THE DEEPENING
UPPER AND SURFACE WAVES WITH 500 MB WINDS OF 95KTS OVR SOUTHERN IL
TOMORROW EVENING. LOOKS TO BE A CLASSIC COOL SEASON SEVERE WEATHER
EVENT WITH LOW CAPE/HIGH SHEAR VALUES. ONCE THE STORMS DEVELOP EARLY
TOMORROW EVENING...IT SHOULDN`T TAKE LONG FOR THEM TO PUSH NNE THRU
SOUTHEAST IL WITH CELL MOTION BEING NE AT 60 KTS. PRIMARY TIME FRAME
FOR ACTIVE WEATHER OVER SOUTHEAST IL WOULD BE FROM 6PM UNTIL MIDNIGHT.
SMITH
&&
.AVIATION...
ISSUED 530 PM CST SAT JAN 21 2012
MOVEMENT OF MVFR CLOUD SHIELD JUST TO OUR SOUTH THE MAIN FORECAST
CONCERN TONIGHT...IN ADDITION TO WIND AND RAIN CHANCES ON SUNDAY.
LEADING EDGE OF STRATUS DECK IS NOW BEGINNING TO MAKE A TURN MORE
TOWARDS THE NORTHWEST AS BOUNDARY LAYER TO 925 MB WINDS SLOWLY
TURN MORE INTO AN EAST TO SOUTHEAST DIRECTION. FORECAST SOUNDINGS
INDICATE THE POTENTIAL FOR LOW LEVEL WIND SHEARLOW LEVEL WINDS WILL
BE CLOSE TO LLWS CRITERIA AFTR 09Z ACRS PIA AND SPI BUT AT THIS TIME
IT APPEARS THE STRONGEST CORE OF WINDS WILL REMAIN JUST WEST OF
BOTH SITES. NEXT STORM SYSTEM WILL START TO DRAW WARN MOIST AIR
NORTHWARD INTO OUR AREA ON SUNDAY WITH A DEVELOPING WARM FRONT
TO OUR SOUTH. THIS WILL LEAD TO WIDESPREAD MVFR AND LOCAL IFR
CIGS WITH POSSIBLY SOME LIGHT DRIZZLE/FZDZ IN THE MORNING ACRS
PIA AND BMI. FOR NOW...PROBABILITIES TOO LOW TO INCLUDE IN TAFS
AT THIS TIME. THE STRONGEST DYNAMICS WITH THIS STORM WILL PUSH
INTO OUR AREA AFTER THIS FORECAST PERIOD BUT WE MAY SEE SOME
ISOLD SHOWERS DEVELOP IN THE BROAD LOW LEVEL WARM ADVECTION PATTERN
AHEAD OF THE MAIN SURFACE LOW.
WINDS WILL BE EAST TONIGHT AT 10 TO 15 KTS AND THEN BEGIN TO VEER
MORE INTO THE SOUTHEAST LATER TONIGHT AND ESPECIALLY ON SUNDAY.
WINDS WILL INCREASE AS THE STORM DRAWS CLOSER TO THE AREA WITH
GUSTS ARND 25 KTS POSSIBLE BY AFTN.
SMITH
&&
.PREV DISCUSSION...
ISSUED 300 PM CST SAT JAN 21 2012
SHORT TERM...TONIGHT THROUGH TUESDAY...
FORECAST FOCUS IN THE SHORT TERM WILL BE ON THE EVOLUTION OF THE
STRONG UPPER WAVE NOW MOVING THROUGH NV. THE TROUGH WILL DEEPEN AND
INDUCE RAPID CYCLOGENESIS IN THE AREA OF KS/NEB BY SUNDAY MORNING.
THE RESULTANT PRESSURE FALLS WILL SPREAD EASTWARD THROUGH THE DAY
WITH INCREASING SOUTHERLY LOW LEVEL FLOW BRINGING STRONG MOISTURE
FLUX FROM A WIDE-OPEN GULF OF MEXICO. EXPECT LOW CLOUDS TO INCREASE
AGAIN LATER TONIGHT WELL AHEAD OF THE SYSTEM WITH TEMPERATURES
RISING AFTER MIDNIGHT. SOME FREEZING DRIZZLE WILL BE POSSIBLE IN THE
MORNING UNTIL THE TEMPERATURES WARM ABOVE FREEZING...WHICH SHOULD BE
BY NOON. BY AFTERNOON...SOME SCATTERED ELEVATED SHOWERS WILL BE
POSSIBLE WITHIN THE LARGELY UNFOCUSED WARM ADVECTION REGIME OVER IL.
BY 00Z MONDAY...THUNDERSTORMS WILL BE INCREASING ALONG THE PACIFIC
FRONT ASSOCIATED WITH THE UPPER TROUGH WHICH WILL BE TAKING ON A
NEGATIVE TILT AS IT MOVES ACROSS THE MIDDLE MS VALLEY. THE NEGATIVE
TILT CONFIGURATION WILL CAUSE STRONG DIFFERENTIAL PVA WHICH WILL
ENHANCE LARGE-SCALE ASCENT...WHILE A STRONG/VEERING WIND PROFILE
PROMOTES LARGE VALUES OF BULK SHEAR AND LOW LEVEL HELICITY.
INSTABILITY WILL NOT BE PARTICULARLY HIGH BUT IT WILL BE ADEQUATE
FOR VIGOROUS UPDRAFTS WITHIN THE STRONGLY FORCED AIRMASS...WITH
SHEAR PROFILES FAVORING MESOCYCLONE/TORNADO FORMATION. TORNADOES
WILL BE MOST PREVALENT DURING THE INITIAL PHASES OF STORM FORMATION
TO OUR SOUTHWEST...BUT SUPERCELLS AND QLCS STORMS WILL BE POSSIBLE
IN THE EARLY TO MID EVENING AS FAR NORTHEAST AS THE INTERSTATE 70
CORRIDOR. WILL THEREFORE GO CATEGORICAL FOR POPS AND THUNDER FOR THE
EVENING HOURS. THE SHORT RANGE MODELS HAVE DIFFERENCES IN TIMING...
WITH SOME SUGGESTING THE STORMS WILL BE INTO INDIANA BY 06Z...AND
OTHERS ON THE SLOWER SIDE. WILL KEEP SOME CHANCE POPS FOR SHOWERS
AFTER 06Z MONDAY IN THE FAR EASTERN COUNTIES.
GUSTY WEST/NORTHWEST WINDS WILL BRING COLD ADVECTION INTO THE AREA
AS THE SURFACE/UPPER LOW DEEPENS AND BECOMES VERTICALLY STACKED OVER
THE GREAT LAKES ON MONDAY. AN EXTENSIVE AREA OF WRAP-AROUND MOISTURE
WILL BE LIKELY WITH A SLIGHT CHANCE OF SOME LIGHT SNOW OVER THE
NORTHERN AREAS ALONG INTERSTATE 74. TUESDAY SHOULD BE DRY AS HIGH
PRESSURE MOVES THROUGH THE MIDWEST.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
ACTIVE NORTHERN AND SOUTHERN STREAMS WILL BE THE RULE THROUGH THE
EXTENDED PERIOD. MODELS ARE STARTING TO COME TOGETHER WITH KEEPING
THE TWO STREAMS MOSTLY SEPARATED. NORTHERN STREAM WAVES ARE FORECAST
TO MOVE ACROSS THE US/CANADIAN BORDER INTO THE GREAT LAKES WITH
ASSOCIATED COLD FRONTS MOVING THROUGH IL BOTH THURSDAY AND FRIDAY.
THESE FRONTS SHOULD BE DRY AS THEY PASS THROUGH THE AREA AS THE
DYNAMICS REMAIN TO THE NORTH AND QUALITY MOISTURE STAYS BOTTLED UP
OVER THE GULF STATES AND APPALACHIANS. A WAVE ALONG THE THURSDAY
FRONT MAY BRING SOME RAIN TO SOUTHERN IL...SO WILL HAVE SOME CHANCE
AND SLIGHT CHANCE POPS FOR THE SOUTHEASTERN COUNTIES WEDNESDAY
NIGHT.
MEANWHILE IN THE SOUTHERN STREAM...A CUTOFF LOW OVER MEXICO
JUST SOUTHWEST OF THE RIO GRANDE IS FORECAST TO WEAKEN AS IT MOVES
EAST-NORTHEAST TOWARD THE LOWER MS VALLEY BY THE END OF NEXT WEEK.
THERE REMAINS SOME MODEL DIFFERENCES WITH THIS FEATURE...BUT EVEN
THE NORTHERN-MOST DGEX MODEL KEEPS MOST OF THE PRECIPITATION TO THE
SOUTH OF THE FORECAST AREA. THE GFS AND ECMWF MODELS KEEP THE
PRECIPITATION EVEN FURTHER SOUTH. SO THE BOTTOM LINE WILL BE A DRY
EXTENDED PERIOD WITH THE EXCEPTION OF THE CHANCE POPS OVER THE
SOUTHEAST WEDNESDAY NIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1243 PM EST FRI JAN 20 2012
.UPDATE...
REGIONAL RADAR MOSAIC CONTINUES TO SHOW INTENSIFYING BAND OF SNOW
FROM EAST CENTRAL IOWA INTO NORTH CENTRAL ILLINOIS. THIS ZONE OF
STRONGER ISENTROPIC ASCENT WILL OVERSPREAD NORTHERN HALF OF AREA
LATER THIS AFTERNOON INTO TONIGHT. A FEW REPORTS OF 5 TO 6 INCHES
OF SNOW ACCUMULATION ALREADY HAVE BEEN REPORTED ACROSS NORTHWEST
IOWA. STILL SOME CONCERN FOR SOME AREAS RECEIVING WARNING CRITERIA
ACCUMULATIONS BY LATE EVENING. NAM/GFS ISENTROPIC PROGS CONTINUE
TO INDICATE SOME SLIGHT WEAKENING OF ISENTROPIC UPGLIDE AS
STRONGEST FORCING FROM EASTERN IOWA/NORTHERN ILLINOIS TRACKS INTO
NORTHERN INDIANA AS NORTHERN VORT MAX ACROSS IOWA/SOUTHERN
MINNESOTA TENDS TO GET MORE SHEARED ACROSS THE SOUTHERN GREAT
LAKES REGION. WILL CONTINUE TO ASSESS 12Z DATA AND OBSERVATIONAL
TRENDS BUT AT THIS TIME WILL MAINTAIN A HIGHER END WINTER WEATHER
ADVISORY FOR SNOW ACCUMULATIONS OF 4 TO 7 INCHES. PERIOD OF MOST
INTENSE SNOWFALL RATES STILL APPEARS TO BE IN THE 21Z-03Z
TIMEFRAME WHEN ISENTROPIC LIFT IS MAXIMIZED ALONG WITH AN
INCREASINGLY FAVORABLE COLOCATION OF DENDRITIC GROWTH ZONE AND
UPWARD MOTION. ONLY OTHER TWEAK TO FORECAST WAS TO CONTINUE TREND
OF INCREASING SNOWFALL AMOUNTS ACROSS SOUTHERN HALF OF CWA. SOME
INDICATIONS IN HRRR OUTPUT OF SECONDARY BANDED AREA OF SNOW DEVELOPING
LATER THIS EVENING ACROSS LOCATIONS FURTHER SOUTH AS LOW LEVEL
FRONTOGENESIS BEGINS TO INCREASE IN RESPONSE TO SECONDARY UPPER
LEVEL WAVE PROGRESSING THROUGH THE CENTRAL PLAINS THIS AFTERNOON.
&&
.AVIATION...
18Z TAFS...DETERIORATING CONDITIONS FOR AVIATION WEATHER THROUGH
THE REMAINDER OF THE AFTERNOON. LOW LEVELS WILL CONTINUE TO
SATURATE OVER THE NEXT FEW HOURS AS AN AREA OF STRONG WARM
ADVECTION SHIFTS EASTWARD FROM THE WESTERN GREAT LAKES REGION.
STRONGEST FORCING STILL APPEARS TO BE IN THE 22Z-03Z TIMEFRAME
WHEN THE HEAVIEST SNOWFALL RATES ARE EXPECTED ALONG WITH PERIODS
OF LIFR CONDITIONS IN HEAVIER SNOWFALL. SYSTEM SHOULD BEGIN TO
EXIT TO THE EAST AFTER 06Z...ALTHOUGH SNOW MAY LINGER INTO MUCH OF
THE OVERNIGHT AT KFWA AS A SECONDARY UPPER LEVEL SHORT WAVE LIFTS
NORTHEAST FROM THE CENTRAL PLAINS. TREND TO VFR CONDITIONS IS THEN
EXPECTED FOR SATURDAY MORNING AS THE SYSTEM EXITS THE AREA. EAST
SOUTHEAST WINDS THIS AFTERNOON WILL BACK MORE NORTHERLY TOWARD THE
END OF THE PERIOD AS THE SFC LOW ASSOCIATED WITH THIS SYSTEM TRACK
SOUTH OF THE AREA.
&&
PREV DISCUSSION... /ISSUED 422 AM EST FRI JAN 20 2012/
SHORT TERM.../TODAY THROUGH SATURDAY NIGHT/
SHRTWV MOVG ACROSS THE ROCKIES THIS MORNING RESULTING IN AN AREA
OF SNOW OVER SD/MN/IA. THIS SYSTEM WILL MOVE RAPIDLY EAST TODAY
AND TONIGHT CAUSING SNOW TO OVERSPREAD OUR AREA. STRONG H85
THETA-E ADVECTION AND DECENT UPR LEVEL DIVERGENCE IN RIGHT
ENTRANCE REGION OF JET AHEAD OF THE SHRTWV ALONG WITH MODEST
H85-H7 FRONTOGENESIS APPEAR TO BE MAIN FORCING MECHANISMS FOR
PRECIP SPREADING INTO OUR AREA. MODELS SIMILAR IN MOVG A MODERATE
AREA OF SNOW ACROSS THE AREA TODAY. GFS/SREF ARE A BIT FASTER TO
MOVE THE PRECIP INTO THE CWA... AND APPEAR TO BE HANDLING THE
EASTWARD PROGRESSION BETTER THAN THE NAM. THUS, CONTD WITH LIKELY
POPS BY MIDDAY ACROSS NW 1/3 OF CWA WITH SNOW EXPECTED TO
OVERSPREAD THE ENTIRE AREA THIS AFTN. EMPIRICAL SNOWFALL FCSTG
METHODS AND MODEL QPF CONT TO SUGGEST 5-7 INCHES IN 12-18HRS
ACROSS NRN PORTION OF THE CWA. MODELS HAVE ALSO TRENDED FARTHER
SOUTH WITH SGFNT QPF SUGGESTING 2-4 INCHES OF ACCUMS ACROSS SRN
PORTION OF CWA AS WELL SO EXPANDED EARLIER ISSUED WINTER WX
ADVISORY ACROSS REMAINDER OF THE CWA. TEMPS OFF TO A COLD START
THIS MORNING...GENERALLY IN THE SINGLE DIGITS AND DESPITE FAIRLY
STRONG H85 WAA DVLPG TODAY WILL STRUGGLE TO REACH THE L20S AS
DVLPG SFC EASTERLY FLOW...CLOUD COVER AND PRECIP HINDER RISES. WK
CAA BEHIND THE SHRTWV OVERNIGHT ALONG WITH LINGERING CLOUD COVER
SHOULD ONLY ALLOW TEMPS TO FALL 5-10F FROM AFTN HIGHS. SFC HIGH
PRESSURE WILL MOVE ACROSS THE GRTLKS SATURDAY/SATURDAY NIGHT
PROVIDING FAIR WX. WAA WILL GRADUALLY STRENGTHEN DURING THIS
PERIOD BUT WITH FRESH SNOW COVER IN PLACE EXPECT TEMPS WILL REMAIN
RATHER COLD WITH HIGHS IN THE M20S AND LOWS IN THE TEENS.
LONG TERM... / SUNDAY THROUGH THURSDAY /
PROGRESSIVE FLOW PATTERN FROM EAST ASIA TO NOAM WILL ALLOW PACIFIC
AIR TO FLOOD INTO MUCH OF THE LOWER 48 THIS PERIOD AS POLAR VORTEX
RE-FOCUSES INTO THE GULF OF ALASKA. THIS WILL SUPPORT TEMPS
GENERALLY ABOVE NORMAL AND SEVERAL CHANCES FOR PCPN SUNDAY INTO NEXT
WEEK. OPTED TO TAILOR GRIDS/FCST TOWARDS THE MORE CONSISTENT 12/00Z
ECMWF DAYS 3/4 AND CLOSER TO A MODEL CONSENSUS THEREAFTER.
A POTENT SHORTWAVE TROUGH WILL LIKELY EJECT INTO THE CENTRAL PLAINS
ON SUNDAY AND THEN TAKE ON A NEGATIVE TILT AS IT PIVOTS INTO THE MID
MS VALLEY AND GREAT LAKES BY SUNDAY NIGHT/MONDAY. MID LVL HEIGHT
FALLS WITH THIS FEATURE WILL INDUCE SFC CYCLOGENESIS WITH A
DEEPENING CYCLONE PROGGED TO TRACK WEST OF THE FA TOWARDS THE
WESTERN GREAT LAKES DURING THIS TIME...WITH A DEVELOPING 50-60 KT
LLJ SUPPORTING SIGNIFICANT LOW LVL MOISTURE/THETA-E ADVECTION NWD
INTO THE AREA. GEM/ECMWF PROGS BRING SFC DEWPOINTS INTO THE MID 40S
TO LOW 50S TOWARDS DAYBREAK MONDAY. THIS LOOKS TO BE CONCURRENT WITH
THE ARRIVAL OF STEEP MID LVL LAPSE RATES WHICH SUPPORTS THE
INHERITED SLIGHT CHC FOR THUNDER AND HVY RAIN LATER SUNDAY NIGHT
INTO MONDAY MORNING. ISSUED A ESF TO COVER HYDRO CONCERNS GIVEN SNOW
MELT...RECENT HEAVY RAINFALL IN THE SOUTH/EAST...AND THE POTENTIAL
FOR LOCALIZED HEAVIER RAIN. OTHERWISE...EXPECT MAINLY DRY CONDITIONS
DURING THE DAY ON SUNDAY WITH A COMBINATION OF MELTING
SNOW...MOISTURE ADVECTION...AND THE RESULTING INVERSION SUPPORTING
INCREASING/LOWERING STRATUS AND THE POTENTIAL FOR SOME
DRIZZLE/FOG/LIGHT SHOWERS BY LATE SUNDAY AFTERNOON INTO SUNDAY
EVENING BEFORE STRONGER FORCING ARRIVES.
LOW LEVEL CAA IN THE WAKE OF THE SYSTEM CDFNT MONDAY MORNING SHOULD
ALLOW FOR FALLING TEMPS MONDAY AFTERNOON...WITH SCT RAIN SHOWERS
CHANGING TO SNOW SHOWERS BY MONDAY AFTN/EVE AS WRAP AROUND MOISTURE
PIVOTS THROUGH. ONLY MINOR ACCUMS EXPECTED...MAINLY NW. DRY WITH
NEAR NORMAL TEMPS TUESDAY AS SHORTWAVE TROUGH LIFTS OUT. A MODEL
CONSENSUS KEEPS THE NEXT UPPER TROUGH IN PROGRESSIVE FLOW FRACTURED
AND UNPHASED RESULTING IN A WEAKER SYSTEM AND ONLY LOWER CHC POPS
FOR SOME LIGHT RAIN OR SNOW BY WEDNESDAY/THURSDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 7 AM EST /6 AM CST/ SATURDAY FOR
INZ003>009-012>018-020-022>027-032>034.
MI...WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR MIZ077>081.
OH...WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR OHZ001-002-
004-005-015-016-024-025.
LM...NONE.
&&
$$
SHORT TERM...JT
LONG TERM...STEINWEDEL
AVIATION...MARSILI
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1224 AM EST FRI JAN 20 2012
.AVIATION..../06Z TAFS/
MVFR DECK TO E-SE OF LM APPEARS TO BE EXPANDING ON SATELLITE
IMAGERY EARLY THIS MORNING. WITH LOW LEVEL FLOW BECOMING
LIGHT/VARIABLE AS HIGH PRESSURE MOVES ACROSS THE AREA EARLY THIS
MORNING...THIS CLOUD DECK MAY NOT FULLY DISSIPATE BEFORE CIGS
LOWER AGAIN IN THE AFTERNOON AS ANOTHER SHRTWV BRINGS WIDESPREAD
ACCUMULATING SNOW BACK INTO NRN INDIANA RESULTING IN IFR/LIFR
CONDITIONS FRI AFTN/EVE.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
SIGNIFICANT SNOW ACCUMULATIONS FRIDAY/FRIDAY NIGHT WILL BE THE MAIN
CONCERN FOR THE SHORT TERM. A WINTER WEATHER ADVISORY WILL BE ISSUED
FOR LATE MORNING FRIDAY THROUGH FRIDAY NIGHT FOR APPROXIMATELY
NORTHERN TWO THIRDS OF THE FORECAST AREA.
ACCUMULATING LIGHT SNOW THIS AFTERNOON HAS SHIFTED WELL SOUTH OF
ROUTE 30 LATE THIS AFTERNOON...AND WILL CONTINUE TO SAG SOUTHWARD
THROUGH THE REMAINDER OF THE LATE AFTERNOON HOURS AS AXIS OF LOW
LEVEL FRONTOGENESIS PUSHES SOUTH OF THE FORECAST AREA. FURTHER TO
THE NORTH...LAKE EFFECT SNOW SHOWERS HAVE BEEN INCREASING IN
INTENSITY WITH FAIRLY STRONG 850 HPA/LAKE DELTA TEMPS ON THE ORDER
OF 20 TO 23 DEGREES. RUC SOUNDINGS SUGGEST A NEARLY ISOTHERMAL LAYER
FROM 850 TO 700 HPA WHICH IS LIMITING DEPTH OF THIS LAKE GENERATED
INSTABILITY WITH LAKE INDUCED EQUILIBRIUM HEIGHTS ON THE ORDER OF
ABOUT 5K FT. ANOTHER NEGATIVE FACTOR POINTING AGAINST SIGNIFICANT
LAKE EFFECT SNOW ACCUMULATIONS IS MUCH DRIER MID LEVEL AIR THAT WAS
WORKED INTO THE SOUTHERN GREAT LAKES REGION BEHIND THE SYSTEM WHICH
BROUGHT THE ACCUMULATING SNOW TODAY. THIS MARGINAL LAKE EFFECT SETUP
WILL CONTINUE FOR MUCH OF THE EVENING AND INTO THE OVERNIGHT...AND A
FEW LOCATIONS MAY PICK UP A HALF INCH TO AN INCH OF ADDITIONAL
ACCUMULATION BEFORE INVERSION HEIGHTS CRASH MORE SUBSTANTIALLY
DURING THE OVERNIGHT HOURS. AREAS AWAY FROM LAKE EFFECT
CLOUDS/PRECIP SHOULD CLEAR THIS EVENING. A WEAKENING GRADIENT WITH
SFC RIDGE AXIS BUILDING IN COMBINED WITH THIS CLEARING SHOULD
ALLOW FOR VERY COLD TEMPS TONIGHT INTO THE SINGLE DIGITS ABOVE
ZERO. SOME INCREASE IN HIGH CLOUDS IS EXPECTED LATE TONIGHT THAT
MAY LEVEL OUT TEMPERATURES AFTER 09Z.
ATTENTION WILL THEN TURN TO WHAT WILL BE A VERY FAST MOVING UPPER
LEVEL SYSTEM THAT IS APPROACHING THE PACIFIC NORTHWEST COAST AT THIS
TIME. LOW LEVEL WINDS WILL BACK SOUTHWESTERLY ON FRIDAY AHEAD OF
THIS TROUGH WHICH WILL SET UP A PERIOD OF INTENSE ISENTROPIC UPGLIDE
FRIDAY AFTERNOON/EARLY EVENING OVER THE SHALLOW RETREATING ARCTIC
AIR MASS. STRONG FRONTOGENETIC FORCING ALSO TO DEVELOP IN THE
850/700 LAYER AS THIS LOW LEVEL FLOW RAMPS UP. 12Z NAM REMAINS A
SLIGHTLY SLOWER AND FURTHER NORTH OUTLIER IN REGARDS TO THIS
SYSTEM...WITH 09Z SREF GENERALLY LENDING SUPPORT TO THE MORE RUN TO
RUN CONSISTENT GFS/ECMWF. GENERALLY UTILIZED A PREDOMINATELY
SREF/GFS/ECMWF BLEND FOR THIS FORECAST WITH A MUCH SMALLER
WEIGHTING TOWARD NAM. PERIOD OF MOST INTENSE SNOWFALL APPEARS TO
BE SHAPING UP IN THE 21Z-03Z TIMEFRAME WITH BEST COLOCATION OF
STRONGER SYNOPTIC LIFT WITH FAVORABLE DENDRITIC GROWTH ZONE.
MODEL QPF FROM 12Z SUITE OF MODELS STILL TEND TO SUPPORT MAINLY
HIGH END ADVISORY LEVEL SNOW ACCUMULATIONS WHEN CONSIDERING
EXPECTED SNOW TO LIQUID RATIOS ON THE ORDER OF 15:1 ACROSS THE
NORTH.
CONCERN WITH THESE TYPE OF INTENSE LOW/MID LEVEL BAROCLINIC ZONES IS
FOR AREAS OF ENHANCED BANDING WHICH COULD PUSH SOME AREAS INTO LOW
END WARNING ACCUMULATIONS. 12Z GFS MODEL CROSS SECTIONS STILL
INDICATE RELATIVELY HIGH STATIC STABILITY ATOP THIS LOW LEVEL
FRONTOGENESIS FORCING WHICH MAY TEND TO DISCOURAGE SMALLER SCALE
INTENSE BANDING...AND A BROADER RESPONSE IN UPWARD VERTICAL MOTION
FIELDS. SYSTEM ALSO WILL BE VERY PROGRESSIVE WITH SOME INDICATIONS
OF ISENTROPIC UPGLIDE WEAKENING SLIGHTLY FROM WEST TO EAST INTO
NORTHEAST INDIANA BY EVENING. TAKING THE ABOVE FACTORS INTO
CONSIDERATION HAVE OPTED TO GO WITH A HIGH END WINTER WEATHER
ADVISORY FOR SNOW ACCUMULATIONS OF 3 TO 7 INCHES NORTHERN TWO
THIRDS...WITH THE HIGHER ACCUMULATIONS EXPECTED FAR NORTHERN
INDIANA/SOUTHERN LOWER MICHIGAN. WINDS NOT EXPECTED TO BE AN OVERLY
HUGE CONCERN WITH THIS SYSTEM...BUT A BRIEF PERIOD IN THE 21Z-03Z
TIMEFRAME OF 1 TO 2 INCH PER HOUR SNOWFALL RATES APPEARS TO BE A
GOOD POSSIBILITY. IN TRENDING MORE TOWARD GFS...HAVE CONFINED MIXED
PRECIP MENTION TO A CHANCE OF SLEET ACROSS THE SOUTH BUT THIS WILL
NEED TO BE WATCHED IN FUTURE FORECASTS ONCE CONFIDENCE IN LOW LEVEL
THERMAL FIELDS INCREASES. SNOW WILL BEGIN TO WANE LATE FRIDAY NIGHT
WITH INDICATIONS OF FAR SOUTHEAST GETTING INTO SOME ENHANCED
SNOWFALL AS A PIECE OF EASTERN PACIFIC SHORT WAVE DIGS MORE
AGGRESSIVELY INTO THE OHIO RIVER VALLEY.
LONG TERM...
SUNDAY THROUGH THURSDAY
SIG PATTERN ADJUSTMENT TO OCCUR IN THE LONG TERM PERIOD AS REX BLOCK
RIDGING SHIFTS WEST OVER ALASKA...WITH SUBSTANTIAL UPPER LEVEL
TROUGHING EXPECTED THERE BY THIS WEEKEND. THIS WILL RESULT IN A
SWITCH BACK TO FAST WESTERLY GENERALLY MILD FLOW...WITH EMBEDDED
FAST MOVING IMPULSES PROVIDING PERIODIC CHANCES FOR RAIN/SNOW. THIS
WILL OCCUR AFTER THE ADVECTION OF A POTENT MID LATITUDE CYCLONE
EARLY NEXT WEEK...A SYSTEM WHICH COULD BRING A SUBSTANTIAL AMOUNT OF
RAIN/WIND/AND EVEN THUNDERSTORMS TO THE AREA SUNDAY NIGHT INTO
MONDAY MORNING. ECMWF/GFS/AND GEFS SOLUTIONS CONTINUE TO REMAIN
NEARLY PHASED PER HEIGHT SOLUTIONS IN THE PERIOD...WITH INCREASED
FORECAST CONFIDENCE IN THE PERIOD.
SAT-MON...FRIDAY SYSTEM WILL BE IN THE PROCESSES OF EXITING THE
REGION WITH A LOW CHANCE FOR LINGERING LIGHT SNOW FAR SE SAT AM.
WEAK SUBSIDENT REGIME WITH SFC RIDGING WILL SUPPORT GRADUAL EROSION
OF LINGERING LOW CLOUDS...WITH WINDS VEERING SE THROUGH THE SAT
PERIOD. MEANWHILE...A SIG MID LEVEL TROUGH IS EXPECTED TO DIG INTO
THE SW CONUS AND BEGIN TO EJECT TOWARD THE REGION. SYSTEM INFLUENCE
TO THE LOCAL AREA WILL BEGIN ON SUNDAY...WITH REFLECTED LL SOUTHERLY
FLOW INCREASING THROUGH THE SUNDAY DAY PERIOD. LINGERING BAROCLINIC
ZONE IN PLACE OVER THE CENTRAL PLAINS WILL INTERACT WITH THE
EJECTING MID LEVEL DISTURBANCE TO SUPPORT ROBUST SFC PRESSURE
FALLS...SUPPORTING RAPID SFC CYCLOGENESIS. THIS WILL ALLOW SIG LL
THETA-E ADV TO ENSUE SUNDAY IN THE REGION WITH SIG SFC LAYER
DEWPOINT RISES INTO SUNDAY NIGHT. STAUNCH LL FLOW WITH A 60 TO 70
KNOT LLJ PROGGED IN THE ECMWF...WILL BE MORE THAN ENOUGH TO SUPPORT
DEEP LAYER THETA-E RISES. SNOWPACK IN PLACE WILL LIKELY SUPPORT A
SATURATED BL WITH DRIZZLE AND FOG EXPECTED TO DEVELOP SUNDAY
AFTERNOON INTO THE EVENING...LIKELY PERSISTING THROUGH SUNDAY NIGHT.
ECMWF H7-H3 LAYER ANALYSIS REVEALS A RATHER IMPRESSIVE EML WITH
STEEP MID LEVEL LAPSE RATES GIVEN STRONG LOW CENTERED WAA. H85
THETA-E APPROACHES 325K BY LATE SUNDAY NIGHT...WITH SW INDICES
NEGATIVE...INDICATING A GOOD ENVIRONMENT FOR ELEVATED THUNDERSTORMS.
HAVE INTRODUCED A LOW CHANCE THUNDER AT THIS POINT. ALBEIT
SMALL...THERE IS A CONCERN FOR SEVERE WEATHER GIVEN INDICATED H5
JETLET IN EXCESS OF 90 KNOTS...WHICH WOULD BE CAPABLE QLCS JET
DRIVEN CELLS. PERHAPS THE BIGGEST CONCERN ATTM IS FOR INCREASED
FLOODING CONCERNS GIVEN FULL SNOWPACK MELT WITH THE POTENTIAL FOR
HEAVY RAIN. WILL HIGHLIGHT IN AN ESF. NEGATIVE TROUGH TILT INDICATED
IN FORECAST MODELS SUGGEST A NW TRACK ADJUSTMENT PER THE SFC
LOW...WITH A SLOWER SYSTEM ARRIVAL POSSIBLE...IN ADDITION TO WARMER
THERMAL FIELDS. HENCE DROPPED THE SNOW MENTION SUN NIGHT/TRIMMED
MONDAY SNOW MENTION/AND ADJUSTED TEMPS UP. CAA WILL DOMINATE MONDAY
WITH FALLING TEMPS IN THE DAYTIME PERIOD LIKELY. LINGERING LIGHT
SNOW SHOWERS WILL BE POSSIBLE MAINLY NW.
TUE-THUR...FAST WNW PAC ORIGIN FLOW IS EXPECTED INTO THE REGION WITH
ROCKIES ENHANCED IMPULSES EXPECTED. STRONGEST PROGGED IMPULSE
REMAINS IN THE WED PERIOD AND HAVE RETAINED POPS THEN...OPTING TO
KEEP THE RAIN/SNOW WORDING GIVEN WARM THERMAL FIELDS.
OTHERWISE...ADJUSTED TEMPS UP SOME...WITH ABOVE NORMAL TEMPS LIKELY
ONCE AGAIN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 10 AM EST /9 AM CST/ THIS MORNING
TO 7 AM EST /6 AM CST/ SATURDAY FOR INZ003>009-012-014-
016>018.
MI...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 7 AM EST
SATURDAY FOR MIZ077>081.
OH...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 7 AM EST
SATURDAY FOR OHZ001-002-004-005-015-016.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
LMZ043-046.
&&
$$
SHORT TERM...MARSILI
LONG TERM...JC
AVIATION...JT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
825 PM MST SAT JAN 21 2012
.DISCUSSION...
825 PM MST SAT JAN 21 2012
LATEST 00Z NAM SHOWING THE UPPER TROUGH THAT IS TO MOVE ACROSS THE
AREA SUNDAY A BIT SLOWER THAN PREVIOUSLY FORECAST. ITS ALSO
SHOWING STRONGER LOW LEVEL NORTH WINDS AND SLIGHTLY COLDER 850MB
TEMPERATURES. 00Z MET GUIDANCE WINDS AND POPS HAVE INCREASED AS
WELL WITH NEAR CATEGORICAL POPS AT KMCK. 21Z SREF POPS AND WINDS
ALSO RATHER BULLISH. 00Z RUC SHOWING A BIT MORE WIDESPREAD QPF AS
WELL. NO 00Z GFS TO LOOK AT QUITE YET.
IN A NUTSHELL...MAY SEE A BIT MORE WIDESPREAD PRECIPITATION WITH
PERHAPS A BIT MORE SNOW VS A RAIN/SNOW MIX...MAINLY ALONG AND
NORTH OF THE INTERSTATE. ALSO...WINDS MAY BE A BIT HIGHER THEN
CURRENTLY ADVERTISED AND WITH THE POSSIBLE MORE COMMON PRECIP-TYPE
AS SNOW PRODUCE SOME RESTRICTED VISIBILITIES.
007
&&
.AVIATION...
430 PM MST SAT JAN 21 2012
FOR THE 00Z TAFS AT KGLD...VFR EXPECTED. GUSTY S/SW WINDS EXPECTED
THROUGH 12Z BEFORE SHIFTING TO THE NORTHWEST AS A COLD FRONT AND
UPPER LEVEL SYSTEM MOVE THROUGH. BY 15Z WINDS ON THE BACKSIDE OF THE
SYSTEM RAMP UP INTO THE 30-35KT RANGE WITH GUSTS CLOSE TO 50KTS.
BEST CHANCE AT SOME PRECIPITATION NEAR THE TERMINAL AND POSSIBLY A
CIG FLIRTING WITH MVFR WOULD BE BETWEEN 15Z-18Z. BY 23Z WINDS SLOWLY
FALL INTO THE 20G30KT RANGE UNDER A BROKEN MID LEVEL CLOUD DECK.
FOR KMCK EXPECT VFR THROUGH 14Z BEFORE LOWERING INTO THE MVFR RANGE
(CIGS) FROM 14Z-23Z. SHOWERS WILL BE AROUND AND WILL BEGIN AS SNOW
THEN SLOWLY TRANSITION TO RAIN LATER IN THE DAY. NORTHWEST WINDS
WILL RAMP UP BY 14Z PEAKING AROUND 18Z WITH GUSTS OF 45KTS OR SO
BEFORE FALLING INTO THE 22G32KT RANGE BY 23Z. CIGS ALSO RISE BACK
INTO THE VFR RANGE AT THIS TIME.
007
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY FROM 6 AM MST /7 AM CST/ TO 5 PM MST /6 PM CST/
SUNDAY FOR KSZ002>004-015-016-027>029-041-042.
HIGH WIND WATCH FROM 6 AM MST /7 AM CST/ SUNDAY THROUGH SUNDAY
AFTERNOON FOR KSZ001-013-014.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON
FOR KSZ013-027-041.
NE...WIND ADVISORY FROM 6 AM MST /7 AM CST/ TO 5 PM MST /6 PM CST/
SUNDAY FOR NEZ079>081.
CO...WIND ADVISORY FROM 6 AM TO 5 PM MST SUNDAY FOR COZ092.
HIGH WIND WATCH FROM 6 AM MST SUNDAY THROUGH SUNDAY AFTERNOON
FOR COZ090-091.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON
FOR COZ252>254.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
844 PM CST SAT JAN 21 2012
.UPDATE...
UPDATED THE FORECAST TO INSERT SOME PATCHY LIGHT FREEZING DRIZZLE TO
THE FORECAST LATE TONIGHT.
&&
.DISCUSSION...
THE 00Z RUC AND NAM HAVE COME IN CONTINUING TO SHOW STRONG LOW LEVEL
WARM AIR ADVECTION. WITHIN THIS PATTERN AN AREA OF LOW CLOUDS IS
EXPECTED TO DEVELOP AND ADVECT NORTH INTO EASTERN KS WITH DECENT
ISENTROPIC LIFT WITHIN THE STABLE LAYER OF THE STRATUS. THIS COULD
DEVELOP SOME PATCHY DRIZZLE DURING THE MORNING SUNDAY. THE WARM AIR
ADVECTION AT THE SURFACE IS EXPECTED TO CAUSE TEMPS TO GRADUALLY
WARM THROUGH THE NIGHT...BUT THINK THE DRIZZLE COULD DEVELOP BEFORE
TEMPS WARM ABOVE FREEZING. FORECAST SOUNDINGS ALL SHOW SFC TEMPS
ABOVE FREEZING AROUND 7AM. WITH THIS IN MIND AND LITTLE OR NO
ACCUMULATIONS ANTICIPATED IN THE PRE DAWN HOURS...WILL NOT ISSUE ANY
HEADLINE OTHER THAN TO UPDATE THE HAZARDOUS WEATHER OUTLOOK.
OTHERWISE THE FORECAST LOOKS TO BE ON TRACK WITH RESPECT TO THE NEW
NAM REGARDING THE UPPER WAVE FOR SUNDAY AFTERNOON AND SUNDAY
EVENING.
WOLTERS
&&
.AVIATION...
18Z NAM AND 21Z RUC ARE IN GOOD AGREEMENT THAT STRONG WARM AIR
ADVECTION WILL OCCUR WITHIN THE BOUNDARY LAYER AND A STRATUS DECK
WILL ADVECT INTO THE TERMINALS. WITH GOOD AGREEMENT IS FORECAST
SOUNDINGS...CONFIDENCE IS REASONABLE AND WENT AHEAD AND INSERTED IFR
CIGS. MAIN CONCERN IS WHETHER THERE WILL BE ANY DRIZZLE AS THERE
APPEARS TO BE STRONG ISENTROPIC LIFT AND WHETHER TEMPS WILL BE BELOW
FREEZING. AT THIS POINT CONFIDENCE IS MARGINAL SINCE FORECAST
SOUNDINGS ARE RELATIVELY SHALLOW WITH THE STRATUS DECK. NEVERTHELESS
THIS WILL BE SOMETHING CLOSELY WATCHED WITH THE 00Z MODEL RUNS.
WINDS WILL BECOME GUSTY OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS.
THE INCREASING SFC WINDS SHOULD PRECLUDE ANY LOW LEVEL WINDS SHEER
ISSUES.
WOLTERS
&&
.PREV DISCUSSION... /329 PM CST SAT JAN 21 2012/
THROUGH SUNDAY NIGHT...WEAK LOW LEVEL ISENTROPIC ASCENT WORKED WITH
LIMITED MOISTURE TODAY TO PRODUCE A STUBBORN STRATUS CLOUD DECK
ACROSS MUCH OF THE AREA. INCREASED MIXING AND WARM ADVECTION HAS
FINALLY BEGUN TO ERODE THE CLOUDS FROM SOUTHWEST TO NORTHEAST WITH
THE INCREASING SUNSHINE AND SOUTH WINDS HELPING TO WARM TEMPS TO 30
DEGREES AND ABOVE. THE INCREASING SOUTH WINDS ARE IN RESPONSE TO AN
INCOMING UPPER LEVEL STORM SYSTEM AND ASSOCIATED SURFACE LOW
PRESSURE. THE SURFACE LOW WAS RAPIDLY DEEPENING IN THE HIGH PLAINS
WITH PRESSURE FALLS AT 2 MB PER HOUR THIS AFTERNOON. WINDS WILL
INCREASE ACROSS THE AREA OVERNIGHT AND BECOME GUSTY WITH STRONG WARM
ADVECTION ACROSS THE PLAINS. THUS...LOW TEMPS TONIGHT WILL LIKELY
OCCUR SHORTLY AFTER SUNSET WITH TEMPERATURES THEN RISING FROM
MIDNIGHT THROUGH SUNDAY AFTERNOON.
THE STORM SYSTEM AS A WHOLE WILL BE FAST MOVING WITH THE COLD FRONT
ENTERING THE FORECAST AREA AROUND NOON AND PUSHING INTO MISSOURI BY
7 PM. NORTHWEST WINDS WILL BE STRONG IMMEDIATELY BEHIND THE FRONT
AND MAY FLIRT WITH WIND ADVISORY CRITERIA BUT HAVE NOT ISSUED
ANYTHING AT THIS POINT AS IT WILL BE BORDERLINE. TEMPERATURES WILL
ALSO REMAIN FAIRLY WARM BEHIND THE FRONT. THERE WILL BE PLENTY OF
COLD ADVECTION ALOFT IN RELATION TO THE VERY WARM TEMPS IN PLACE BUT
STILL A PACIFIC AIRMASS AND NOT PARTICULARLY COLD RELATIVE TO
TYPICAL JANUARY TEMPS.
AS FAR AS PRECIP CHANCES ARE CONCERNED...IT APPEARS THAT DRIZZLE
WILL BE POSSIBLE ACROSS EASTERN KANSAS DURING THE MORNING HOURS IN
THE WARM MOIST ADVECTION REGIME WITH AMPLE ISENTROPIC ASCENT IN THE
LOW LEVELS. A BETTER CHANCE FOR MEASURABLE PRECIP WILL COME BEHIND
THE COLD FRONT AS THE MAIN UPPER PV ANOMALY MOVES OVERHEAD. DEEP
MOISTURE IS LIMITED...ESPECIALLY WITHIN THE DENDRITIC ZONE BUT LIFT
MAY BE SUFFICIENT TO BRING A BAND OF PRECIP ACROSS THE AREA. THE
BEST CHANCES APPEAR TO BE NORTH OF I-70 BUT COULD EXTEND SOUTH IF
MOISTURE QUALITY IS SUFFICIENT. TEMPERATURE PROFILES ARE BORDERLINE
FOR RAIN CHANGING TO SNOW...AGAIN WITH THE BEST CHANCE FOR LIGHT
SNOW NORTH OF I-70. LITTLE TO NO ACCUMULATION IS EXPECTED. ANY
PRECIP WILL MOVE EAST OF THE AREA BY MIDNIGHT.
BARJENBRUCH
MONDAY THROUGH SATURDAY...EXPECT PRECIP TO COME TO AN END BY EARLY
MONDAY MORNING AS THE UPPER LOW SLIDES OFF TO THE EAST...ALLOWING
FOR LARGE SCALE SUBSIDENCE TO TAKE OVER. FOR THE FIRST HALF OF NEXT
WEEK SHORT WAVE RIDGING WILL MOVE INTO NORTHEAST KANSAS WHICH SHOULD
KEEP MILD TEMPERATURES ACROSS THE AREA FOR MOST OF THE WEEK.
SOUTHERLY WINDS IN RESPONSE TO AN INVERTED TROUGH WHICH WILL LIKELY
TAKE SHAPE OVER THE FAR SOUTHERN HIGH PLAINS. THE WARM UP WILL BE
TEMPERED...ESPECIALLY IN FAR NORTHERN KANSAS AS THE WEAKLY DEFINED
WARM FRONT WILL HAVE A TOUGH TIME REACHING THE KS/NE BORDER.
NONETHELESS THE ENTIRE NORTHEASTERN KANSAS AREA WILL LIKELY SEE
ABOVE NORMAL TEMPS THROUGHOUT THE WEEK WITH HIGHS REGULARLY REACHING
THE MID 40S TO LOWER 50S. NEXT CHANCE FOR PRECIPITATION WILL COME ON
TUESDAY NIGHT OR WEDNESDAY MORNING AS A QUICKLY MOVING NORTHERN
STREAM TROUGH GLIDES THROUGH THE AREA. WITH LOW LEVEL DRY AIR
REMAINING IN PLACE AND MEAGER LIFT DO NOT EXPECT MUCH IN THE WAY OF
PRECIP FROM THIS FLEETING SYSTEM. A SOUTHERN STREAM CUTOFF LOW WILL
BE A BIT MORE DISCERNIBLE DURING THIS TIME PERIOD...HOWEVER MODELS
HAVE BEEN TRENDING THIS CUTOFF LOW FURTHER SOUTH WITH EACH RUN...SO
DO NOT EXPECT ANNY PRECIP FROM THIS TROUGH. ASIDE FROM THIS SLIGHT
CHANCE FOR PRECIP MIDWEEK EXPECT THE REMAINING PORTION OF THE
EXTENDED FORECAST TO REMAIN EVENT FREE WITH MILD TEMPS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
645 PM CST SAT JAN 21 2012
.UPDATE...
HAVE UPDATED THE NPW/HWO TO ACCOUNT FOR THE EXPIRATION OF THE WIND ADVISORY
THAT OCCURRED AT 00Z. WILL CONTINUE HEADLINES FOR TOMORROW AS IS. HAVE
INCREASED WINDS IN THE HIGH WIND WATCH FOR TOMORROW TO ALIGN THE FORECAST
WITH THE RESPECTIVE WIND MAGNITUDE CRITERIA. 18Z NAM STILL SUPPORTS
TOMORROWS HEADLINES AS WELL. 00Z DATA MIGHT CHANGE (HIGHER OR LOWER)
BUT WILL DEFER THAT TO THE MID SHIFT. -SUGDEN
&&
.PREV DISCUSSION... /ISSUED 500 PM CST SAT JAN 21 2012/
AVIATION...
FOR THE 00Z TAF ISSUANCE...MAIN CONCERN IN THE AVIATION WORLD IS
WINDS. FOLLOWED RECENT HRRR GUIDANCE WHICH KEEPS SOUTHERLY WINDS 15
TO 20 KT THROUGH THE OVERNIGHT. MEANWHILE, AN APPROACHING COLD FRONT
IS EXPECTED TO TRAVERSE ACROSS THE REGION BY TOMORROW MORNING. SO
WINDS WILL VEER TO THE SW THEN FINALLY TO THE NW AFTER THE FRONT
PASSES THROUGH. ALL GUIDANCE SUPPORTS STRONG WINDS SO HAVE
INCREASED WINDS IN THE 26-32KT RANGE WITH GUSTS TO 35-40KT BY AND
AFTER 15Z TOMORROW. OTHERWISE, VFR CIGS WILL PREVAIL. -SUGDEN
PREV DISCUSSION... /ISSUED 303 PM CST SAT JAN 21 2012/
DISCUSSION...
DAYS 1-2...
THE MAIN FORECAST FOCUS WILL ON THE CHANCE FOR PRECIP DURING THE
PERIOD AND TEMPERATURES.
WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE A WEAK UPPER LEVEL
RIDGE OF HIGH PRESSURE TRANSITIONING EAST ACROSS THE CENTRAL PLAINS.
MEANWHILE, AN UPPER LEVEL TROUGH OF LOW PRESSURE IS PUSHING ASHORE
IN NORTHERN CALIFORNIA. NEAR THE SURFACE, A LEE SIDE TROUGH OF LOW
PRESSURE PREVAILS ACROSS EASTERN COLORADO.
SHORT RANGE MODELS INDICATE THE UPPER LEVEL TROUGH PUSHING EAST
ACROSS THE FOUR CORNERS REGION TONIGHT AND INTO THE WESTERN HIGH
PLAINS SUNDAY BRINGING THE POSSIBILITY FOR PRECIP TO PORTIONS OF
WESTERN AND CENTRAL KANSAS BY SUNDAY AFTERNOON. A STRONG H5 VORT
MAX IS PROGGED TO PASS THROUGH WESTERN KANSAS BY 18Z IN CONJUNCTION
WITH A COLD FRONT ASSOCIATED WITH THE UPPER TROUGH AXIS. HOWEVER
THE STRONG JET CORE ASSOCIATED WITH THE SYSTEM WILL REMAIN JUST
OFF TO OUR SOUTH ACROSS WEST TEXAS. ADDITIONALLY, LOW LEVEL
MOISTURE WILL BE LACKING WITH H85 DEWPOINTS PROJECTED TO REMAIN
WELL BELOW 0C, NOT TO MENTION A LACK OF MID LEVEL INSTABILITY.
STILL, THE NAM, GFS, AND ECMWF SHOW INCREASED MOISTURE ADVECTION
IN THE MID LEVELS ALONG WITH A POST FRONTAL H7 BAROCLINIC ZONE
PASSING ACROSS WESTERN KANSAS SUNDAY AFTERNOON. CANNOT RULE OUT A
FEW PASSING SPRINKLES OR AN ISOLATED SHOWER OR TWO ACROSS WESTERN
AND CENTRAL KANSAS. AT THE VERY LEAST INCREASED CLOUDINESS WITH
VIRGA WILL BE POSSIBLE CONSIDERING THE DRIER LOW LEVELS. WILL
LOWER POPS DOWN TO SLIGHT CATEGORY ACROSS SOUTH CENTRAL AND
EXTREME SOUTHWEST KANSAS WHILE LEAVING LOW END CHANCE CATEGORY
POPS IN NEAR THE I-70 CORRIDOR.
TEMPERATURES WILL BE MUCH WARMER TONIGHT AS LEE SIDE TROUGHING
STRENGTHENS OVERNIGHT. THIS WILL ENHANCE WARM AIR ADVECTION INTO
WESTERN KANSAS WITHIN A LOW LEVEL SOUTHWESTERLY FLOW RAISING H85
TEMPERATURES UP TO AROUND 10C TO 12C. ADDITIONALLY, MOISTURE
ADVECTION WILL INCREASE SURFACE DEWPOINTS UP INTO THE 20S(F)
ACROSS SOUTH CENTRAL AND SOUTHWEST KANSAS. LOOK FOR LOWS MAINLY
DOWN INTO THE 30S(F) WITH THE WARMER TEMPERATURES ACROSS OUR EXTREME
SOUTHWEST WHERE DOWNSLOPING WILL BE MORE OF A FACTOR TOWARD 12Z.
FOR SUNDAY, A COLD FRONT WILL QUICKLY PUSH EAST ACROSS WESTERN
KANSAS BY LATE MORNING TURNING WINDS NORTHWESTERLY. EVEN SO,
DOWNSLOPING COMBINED WITH THE INITIAL MIXING OF WARMER AIR JUST
OFF THE DECK (H85 TEMPERATURES AROUND 10C) AS THE FRONT MOVES
THROUGH, WILL ALLOW TEMPERATURES TO CLIMB WELL UP INTO THE 40S(F)
WITH SOME LOWER TO MID 50S(F) POSSIBLE BY EARLY AFTERNOON. LOW
TEMPERATURES ARE EXPECTED TO FALL BACK BELOW FREEZING SUNDAY NIGHT
AS DECREASING WINDS AND CLOUDS ACCOMPANY A SMALL AREA OF SURFACE
HIGH PRESSURE MOVING EAST ACROSS SOUTHWEST KANSAS. AS FOR MONDAY,
LEE SIDE TROUGHING WILL QUICKLY DEVELOP ACROSS EASTERN COLORADO
HELPING TO RETURN SOUTHERLY WINDS TO WESTERN KANSAS BY MONDAY
AFTERNOON. THE NAM, GFS, AND ECMWF SHOW H85 TEMPERATURES RANGING
FROM JUST ABOVE 0C ACROSS CENTRAL KANSAS TO NEAR 5C ALONG THE
COLORADO BORDER. ALONG WITH PLENTY OF SUNSHINE, LOOK FOR HIGHS UP
INTO THE 50S(F) MONDAY.
WINDS WILL BE FAIRLY STRONG OUT OF THE NORTHWEST LATE SUNDAY MORNING
AND AFTERNOON. ALL MODELS SHOW H85-H7 WINDS AROUND 40 TO 50KT JUST
BEHIND THE FRONT. WITH SOME MIXING EXPECTED AS THE FRONT MOVES
THROUGH, WIND ADVISORY WINDS ARE EXPECTED TO BE MET. HOWEVER,
LESS CERTAINTY REMAINS AS TO WHERE A BRIEF HIGH WIND GUST MAY
OCCUR TO WARRANT A HIGH WIND WARNING. WILL DEFER TO THE NEXT SHIFT
WITH A HIGH WIND WATCH ALREADY ALERTING THE PUBLIC TO THE POTENTIAL
OF STRONGER WINDS.
DAYS 3-7...
FOR TUESDAY AN UPPER LEVEL SHORTWAVE TROUGH WILL BE GOING THROUGH
THE NORTHERN PLAINS WHILE AN UPPER CLOSED LOW CONTINUES TO DIG INTO
SOUTHERN NEW MEXICO. KANSAS WILL BE IN BETWEEN THESE TWO SYSTEMS
WITH ONLY SOME HIGH LEVEL CLOUDINESS EXPECTED. LOWS ON TUESDAY
MORNING WILL RANGE FROM THE MID TO UPPER 20S. HIGHS WILL BE IN THE
MID TO UPPER 40S, TO AROUND 50 SOUTHEAST FA AROUND MEDICINE LODGE.
FOR WEDNESDAY ANOTHER NORTHERN BRANCH WAVE MOVES ACROSS THE PLAINS
WITH WINDS SHIFTING NORTHERLY WHILE THE SOUTHERN UPPER LOW GETS
CUTOFF IN NORTHERN MEXICO. NEAR THE WIND SHIFT IN THE SOUTHEAST
AROUND MEDICINE LODGE THE DEWPOINTS RISE INTO THE MID 30S WITH A
SLIGHT CHANCE FOR RAIN EARLY WEDNESDAY MORNING. NOT MUCH CHANGE IN
THE TEMPERATURES FOR WEDNESDAY WITH MORNING LOWS IN THE UPPER 20S
NORTH TO MID 3OS SOUTHEAST. HIGHS WILL BE AROUND 50. ON THURSDAY DRY
NORTHWESTERLY FLOW CONTINUES WITH A LEE TROUGH DEVELOPING. LOWS WILL
BE AROUND 30 WITH WARMER HIGHS IN THE MID 50S. FOR FRIDAY A STRONGER
NORTHERN BRANCH SHORTWAVE TROUGH MOVE INTO THE NORTHERN AND CENTRAL
PLAINS WITH COOLER HIGH PRESSURE MOVING INTO THE PLAINS. MORNING
LOWS WILL BE IN THE LOW TO MID 30S WITH HIGH TEMPS A BIT COOLER AND
AROUND 50. ON SATURDAY THE EC MODEL HAS A DEEPER TROUGH MOVING
THROUGH THE UPPER MIDWEST IN THE MORNING, WHILE THE GFS IS FLATTER
WITH A MORE ZONAL FLOW. LOWS LOOK TO BE IN THE MID 20S NORTH TO
AROUND 30 SOUTH WITH COOLER HIGHS IN THE MID 40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 50 22 53 / 0 30 0 0
GCK 35 50 20 52 / 0 30 0 0
EHA 41 52 23 53 / 0 20 0 0
LBL 39 53 20 55 / 0 20 0 0
HYS 31 48 20 50 / 0 30 0 0
P28 32 55 25 55 / 0 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM CST /9 AM MST/ TO 4 PM CST /3 PM MST/
SUNDAY FOR KSZ030-031-045-046-061-064>066-074-078>081-084-
088>090.
HIGH WIND WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON FOR
KSZ043-044-062-063-075>077-085>087.
&&
$$
FN36
AREA FORECAST DISCUSSION
NWS TOPEKA KS
536 PM CST SAT JAN 21 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
18Z NAM AND 21Z RUC ARE IN GOOD AGREEMENT THAT STRONG WARM AIR
ADVECTION WILL OCCUR WITHIN THE BOUNDARY LAYER AND A STRATUS DECK
WILL ADVECT INTO THE TERMINALS. WITH GOOD AGREEMENT IS FORECAST
SOUNDINGS...CONFIDENCE IS REASONABLE AND WENT AHEAD AND INSERTED IFR
CIGS. MAIN CONCERN IS WHETHER THERE WILL BE ANY DRIZZLE AS THERE
APPEARS TO BE STRONG ISENTROPIC LIFT AND WHETHER TEMPS WILL BE BELOW
FREEZING. AT THIS POINT CONFIDENCE IS MARGINAL SINCE FORECAST
SOUNDINGS ARE RELATIVELY SHALLOW WITH THE STRATUS DECK. NEVERTHELESS
THIS WILL BE SOMETHING CLOSELY WATCHED WITH THE 00Z MODEL RUNS.
WINDS WILL BECOME GUSTY OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS.
THE INCREASING SFC WINDS SHOULD PRECLUDE ANY LOW LEVEL WINDS SHEER
ISSUES.
WOLTERS
&&
.PREV DISCUSSION... /329 PM CST SAT JAN 21 2012/
THROUGH SUNDAY NIGHT...WEAK LOW LEVEL ISENTROPIC ASCENT WORKED WITH
LIMITED MOISTURE TODAY TO PRODUCE A STUBBORN STRATUS CLOUD DECK
ACROSS MUCH OF THE AREA. INCREASED MIXING AND WARM ADVECTION HAS
FINALLY BEGUN TO ERODE THE CLOUDS FROM SOUTHWEST TO NORTHEAST WITH
THE INCREASING SUNSHINE AND SOUTH WINDS HELPING TO WARM TEMPS TO 30
DEGREES AND ABOVE. THE INCREASING SOUTH WINDS ARE IN RESPONSE TO AN
INCOMING UPPER LEVEL STORM SYSTEM AND ASSOCIATED SURFACE LOW
PRESSURE. THE SURFACE LOW WAS RAPIDLY DEEPENING IN THE HIGH PLAINS
WITH PRESSURE FALLS AT 2 MB PER HOUR THIS AFTERNOON. WINDS WILL
INCREASE ACROSS THE AREA OVERNIGHT AND BECOME GUSTY WITH STRONG WARM
ADVECTION ACROSS THE PLAINS. THUS...LOW TEMPS TONIGHT WILL LIKELY
OCCUR SHORTLY AFTER SUNSET WITH TEMPERATURES THEN RISING FROM
MIDNIGHT THROUGH SUNDAY AFTERNOON.
THE STORM SYSTEM AS A WHOLE WILL BE FAST MOVING WITH THE COLD FRONT
ENTERING THE FORECAST AREA AROUND NOON AND PUSHING INTO MISSOURI BY
7 PM. NORTHWEST WINDS WILL BE STRONG IMMEDIATELY BEHIND THE FRONT
AND MAY FLIRT WITH WIND ADVISORY CRITERIA BUT HAVE NOT ISSUED
ANYTHING AT THIS POINT AS IT WILL BE BORDERLINE. TEMPERATURES WILL
ALSO REMAIN FAIRLY WARM BEHIND THE FRONT. THERE WILL BE PLENTY OF
COLD ADVECTION ALOFT IN RELATION TO THE VERY WARM TEMPS IN PLACE BUT
STILL A PACIFIC AIRMASS AND NOT PARTICULARLY COLD RELATIVE TO
TYPICAL JANUARY TEMPS.
AS FAR AS PRECIP CHANCES ARE CONCERNED...IT APPEARS THAT DRIZZLE
WILL BE POSSIBLE ACROSS EASTERN KANSAS DURING THE MORNING HOURS IN
THE WARM MOIST ADVECTION REGIME WITH AMPLE ISENTROPIC ASCENT IN THE
LOW LEVELS. A BETTER CHANCE FOR MEASURABLE PRECIP WILL COME BEHIND
THE COLD FRONT AS THE MAIN UPPER PV ANOMALY MOVES OVERHEAD. DEEP
MOISTURE IS LIMITED...ESPECIALLY WITHIN THE DENDRITIC ZONE BUT LIFT
MAY BE SUFFICIENT TO BRING A BAND OF PRECIP ACROSS THE AREA. THE
BEST CHANCES APPEAR TO BE NORTH OF I-70 BUT COULD EXTEND SOUTH IF
MOISTURE QUALITY IS SUFFICIENT. TEMPERATURE PROFILES ARE BORDERLINE
FOR RAIN CHANGING TO SNOW...AGAIN WITH THE BEST CHANCE FOR LIGHT
SNOW NORTH OF I-70. LITTLE TO NO ACCUMULATION IS EXPECTED. ANY
PRECIP WILL MOVE EAST OF THE AREA BY MIDNIGHT.
BARJENBRUCH
MONDAY THROUGH SATURDAY...EXPECT PRECIP TO COME TO AN END BY EARLY
MONDAY MORNING AS THE UPPER LOW SLIDES OFF TO THE EAST...ALLOWING
FOR LARGE SCALE SUBSIDENCE TO TAKE OVER. FOR THE FIRST HALF OF NEXT
WEEK SHORT WAVE RIDGING WILL MOVE INTO NORTHEAST KANSAS WHICH SHOULD
KEEP MILD TEMPERATURES ACROSS THE AREA FOR MOST OF THE WEEK.
SOUTHERLY WINDS IN RESPONSE TO AN INVERTED TROUGH WHICH WILL LIKELY
TAKE SHAPE OVER THE FAR SOUTHERN HIGH PLAINS. THE WARM UP WILL BE
TEMPERED...ESPECIALLY IN FAR NORTHERN KANSAS AS THE WEAKLY DEFINED
WARM FRONT WILL HAVE A TOUGH TIME REACHING THE KS/NE BORDER.
NONETHELESS THE ENTIRE NORTHEASTERN KANSAS AREA WILL LIKELY SEE
ABOVE NORMAL TEMPS THROUGHOUT THE WEEK WITH HIGHS REGULARLY REACHING
THE MID 40S TO LOWER 50S. NEXT CHANCE FOR PRECIPITATION WILL COME ON
TUESDAY NIGHT OR WEDNESDAY MORNING AS A QUICKLY MOVING NORTHERN
STREAM TROUGH GLIDES THROUGH THE AREA. WITH LOW LEVEL DRY AIR
REMAINING IN PLACE AND MEAGER LIFT DO NOT EXPECT MUCH IN THE WAY OF
PRECIP FROM THIS FLEETING SYSTEM. A SOUTHERN STREAM CUTOFF LOW WILL
BE A BIT MORE DISCERNIBLE DURING THIS TIME PERIOD...HOWEVER MODELS
HAVE BEEN TRENDING THIS CUTOFF LOW FURTHER SOUTH WITH EACH RUN...SO
DO NOT EXPECT ANNY PRECIP FROM THIS TROUGH. ASIDE FROM THIS SLIGHT
CHANCE FOR PRECIP MIDWEEK EXPECT THE REMAINING PORTION OF THE
EXTENDED FORECAST TO REMAIN EVENT FREE WITH MILD TEMPS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1045 AM MST FRI JAN 20 2012
.DISCUSSION...
220 AM MST FRI JAN 20 2012
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS CONTINUES TO SHOW LONG
FETCH OF W/NW FLOW ACROSS THE CENTRAL US WITH TROUGH OVER THE
NORTHEAST. AT THE SURFACE A STRONG COLD FRONT CONTINUES TO LINGER
ALONG THE COLORADO/KANSAS STATE LINE WITH A 15-20F SPREAD IN TEMPS
FROM THE EAST TO THE WEST ACROSS THE CWA.
TODAY-SATURDAY...MAIN FOCUS DURING THESE PERIODS CONTINUES TO BE ON
TEMPS ACROSS THE CWA...COMPLICATED BY LINGERING FRONT. THE FRONT IS
EXPECTED TO BEGIN TO LIFT EAST THIS MORNING. WESTERLY FLOW AT THE
SURFACE SHOULD BRING MILD TEMPS INTO THE WESTERN HALF OF THE
CWA...WITH COLD TEMPS LINGER ALL DAY ACROSS THE EASTERN PART OF
THE CWA. A WEAK SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS
LATER TODAY WILL PUSH A REINFORCING SHOT OF COLD AIR SOUTH
TOWARDS THE CWA...RESULTING IN THE COLD FRONT SWINGING BACK
TOWARDS THE W/SW THIS AFTERNOON/EVENING. HIGH TEMPS TODAY MAY BE
REACHED BEFORE NOON OVER CENTRAL PARTS OF THE CWA...WITH A NON-
DIURNAL COOLING TREND POSSIBLE THIS AFTERNOON OVER PARTS OF THE
CWA. CURRENTLY EXPECTING ABOUT A 30F SPREAD IN HIGH TEMPS FROM THE
EAST TO THE WEST...WITH HIGHS NEAR 60F IN EASTERN COLORADO...AND
IN THE UPPER 20S NEAR NORTON. S/SW FLOW DEVELOPS SATURDAY...WHICH
WILL HELP SOUR OUT THE COLDEST AIR FROM MOST OF THE CWA...THOUGH
EASTERN LOCATIONS WILL STILL LIKELY REMAIN BELOW NORMAL.
SUNDAY...A TROUGH DEVELOPING OVER GREAT BASIN WILL PUSH
EAST...WITH THE MEAN TROUGH AXIS OVER WESTERN KANSAS BY 18Z
SUNDAY. LARGE SCALE ASCENT COMBINED WITH INCREASING MOISTURE AHEAD
OF TROUGH AXIS WILL WILL OVERSPREAD CWA SUNDAY MORNING...QUICKLY
PUSHING E/NE OF THE CWA DURING THE AFTERNOON. ECMWF CONTINUES TO
BE THE WETTEST SOLUTION...THOUGH GFS AT LEAST SHOWS SOME SUPPORT
FOR PRECIP IN THE NE CWA. MAIN CHANGE TO PREVIOUS FORECAST WAS TO
BUMP UP POPS UP IN THE N/NE...AND SPEED UP THE EXIT OF PRECIP
DURING THE AFTERNOON FROM THE WEST TO THE EAST. VERY DRY AIR WILL
ADVECT INTO THE CWA FROM THE WEST DURING THE AFTERNOON...WITH
WINDY CONDITIONS DEVELOPING BY MIDDAY. WE MAY NEED TO ISSUE A RED
FLAG WARNING FOR WESTERN PARTS OF THE CWA AND A WIND ADVISORY FOR
THE MAJORITY OF THE CWA...HOWEVER ITS STILL TOO EARLY FOR THIS
FORECAST CYCLE.
DR
FOR THE PERIOD MONDAY THROUGH THURSDAY...A COLD FRONT WILL MOVE
THROUGH THE REGION ON TUESDAY WITH BREEZY NORTHWEST WINDS AND COLDER
TEMPERATURES. MODELS SHOW SOME LIGHT PRECIPITATION WITH THE FRONT
WHICH MAY END UP NOTHING MORE THAN FLURRIES. TEMPERATURES REBOUND
QUICKLY WITH ABOVE NORMAL TEMPERATURES WEDNESDAY AND THURSDAY.
024
&&
.AVIATION...
1006 AM MST FRI JAN 20 2012
FOR THE 18Z TAFS...VFR CONDITIONS ARE EXPECTED THROUGH THE
PREVAILING PERIOD. MODEL SOUNDING ANALYSIS INDICATES SURFACE
SATURATION AFTER 03Z THIS EVENING...INDICATING A CHANCE FOR FOG
DEVELOPMENT. WILL LET NEXT SHIFT EVALUATE. OTHERWISE...GUSTY
NORTHWEST WINDS WILL BECOME CALM OVERNIGHT AS PRESSURE GRADIENT
RELAXES AND SURFACE HIGH MOVES EASTWARD. GUSTY WINDS WILL RETURN
BY MID MORNING AS PRESSURE GRADIENT TIGHTENS ACROSS THE HIGH
PLAINS.
PMM
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
430 AM MST FRI JAN 20 2012
.DISCUSSION...
220 AM MST FRI JAN 20 2012
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS CONTINUES TO SHOW LONG
FETCH OF W/NW FLOW ACROSS THE CENTRAL US WITH TROUGH OVER THE
NORTHEAST. AT THE SURFACE A STRONG COLD FRONT CONTINUES TO LINGER
ALONG THE COLORADO/KANSAS STATE LINE WITH A 15-20F SPREAD IN TEMPS
FROM THE EAST TO THE WEST ACROSS THE CWA.
TODAY-SATURDAY...MAIN FOCUS DURING THESE PERIODS CONTINUES TO BE ON
TEMPS ACROSS THE CWA...COMPLICATED BY LINGERING FRONT. THE FRONT IS
EXPECTED TO BEGIN TO LIFT EAST THIS MORNING. WESTERLY FLOW AT THE
SURFACE SHOULD BRING MILD TEMPS INTO THE WESTERN HALF OF THE
CWA...WITH COLD TEMPS LINGER ALL DAY ACROSS THE EASTERN PART OF
THE CWA. A WEAK SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS
LATER TODAY WILL PUSH A REINFORCING SHOT OF COLD AIR SOUTH
TOWARDS THE CWA...RESULTING IN THE COLD FRONT SWINGING BACK
TOWARDS THE W/SW THIS AFTERNOON/EVENING. HIGH TEMPS TODAY MAY BE
REACHED BEFORE NOON OVER CENTRAL PARTS OF THE CWA...WITH A NON-
DIURNAL COOLING TREND POSSIBLE THIS AFTERNOON OVER PARTS OF THE
CWA. CURRENTLY EXPECTING ABOUT A 30F SPREAD IN HIGH TEMPS FROM THE
EAST TO THE WEST...WITH HIGHS NEAR 60F IN EASTERN COLORADO...AND
IN THE UPPER 20S NEAR NORTON. S/SW FLOW DEVELOPS SATURDAY...WHICH
WILL HELP SOUR OUT THE COLDEST AIR FROM MOST OF THE CWA...THOUGH
EASTERN LOCATIONS WILL STILL LIKELY REMAIN BELOW NORMAL.
SUNDAY...A TROUGH DEVELOPING OVER GREAT BASIN WILL PUSH
EAST...WITH THE MEAN TROUGH AXIS OVER WESTERN KANSAS BY 18Z
SUNDAY. LARGE SCALE ASCENT COMBINED WITH INCREASING MOISTURE AHEAD
OF TROUGH AXIS WILL WILL OVERSPREAD CWA SUNDAY MORNING...QUICKLY
PUSHING E/NE OF THE CWA DURING THE AFTERNOON. ECMWF CONTINUES TO
BE THE WETTEST SOLUTION...THOUGH GFS AT LEAST SHOWS SOME SUPPORT
FOR PRECIP IN THE NE CWA. MAIN CHANGE TO PREVIOUS FORECAST WAS TO
BUMP UP POPS UP IN THE N/NE...AND SPEED UP THE EXIT OF PRECIP
DURING THE AFTERNOON FROM THE WEST TO THE EAST. VERY DRY AIR WILL
ADVECT INTO THE CWA FROM THE WEST DURING THE AFTERNOON...WITH
WINDY CONDITIONS DEVELOPING BY MIDDAY. WE MAY NEED TO ISSUE A RED
FLAG WARNING FOR WESTERN PARTS OF THE CWA AND A WIND ADVISORY FOR
THE MAJORITY OF THE CWA...HOWEVER ITS STILL TOO EARLY FOR THIS
FORECAST CYCLE.
DR
FOR THE PERIOD MONDAY THROUGH THURSDAY...A COLD FRONT WILL MOVE
THROUGH THE REGION ON TUESDAY WITH BREEZY NORTHWEST WINDS AND COLDER
TEMPERATURES. MODELS SHOW SOME LIGHT PRECIPITATION WITH THE FRONT
WHICH MAY END UP NOTHING MORE THAN FLURRIES. TEMPERATURES REBOUND
QUICKLY WITH ABOVE NORMAL TEMPERATURES WEDNESDAY AND THURSDAY.
024
&&
.AVIATION...
430 AM MST FRI JAN 20 2012
FOR THE 12Z TAFS...VFR THROUGH THE PERIOD. A COLD FRONT WILL MOVE
ACROSS THE REGION LATER THIS MORNING WHICH WILL CAUSE WINDS TO VEER
FROM THE SOUTHEAST TO THE NORTHWEST WITH TIME AND BECOME GUSTY.
GUSTS WILL DIMINISH CLOSE TO 00Z. MID/HIGH CLOUDS WILL CONTINUE TO
OVERSPREAD THE REGION WITH BASES 10K-15K FEET.
024
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
220 AM MST FRI JAN 20 2012
.DISCUSSION...
220 AM MST FRI JAN 20 2012
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS CONTINUES TO SHOW LONG
FETCH OF W/NW FLOW ACROSS THE CENTRAL US WITH TROUGH OVER THE
NORTHEAST. AT THE SURFACE A STRONG COLD FRONT CONTINUES TO LINGER
ALONG THE COLORADO/KANSAS STATE LINE WITH A 15-20F SPREAD IN TEMPS
FROM THE EAST TO THE WEST ACROSS THE CWA.
TODAY-SATURDAY...MAIN FOCUS DURING THESE PERIODS CONTINUES TO BE ON
TEMPS ACROSS THE CWA...COMPLICATED BY LINGERING FRONT. THE FRONT IS
EXPECTED TO BEGIN TO LIFT EAST THIS MORNING. WESTERLY FLOW AT THE
SURFACE SHOULD BRING MILD TEMPS INTO THE WESTERN HALF OF THE
CWA...WITH COLD TEMPS LINGER ALL DAY ACROSS THE EASTERN PART OF
THE CWA. A WEAK SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS
LATER TODAY WILL PUSH A REINFORCING SHOT OF COLD AIR SOUTH
TOWARDS THE CWA...RESULTING IN THE COLD FRONT SWINGING BACK
TOWARDS THE W/SW THIS AFTERNOON/EVENING. HIGH TEMPS TODAY MAY BE
REACHED BEFORE NOON OVER CENTRAL PARTS OF THE CWA...WITH A NON-
DIURNAL COOLING TREND POSSIBLE THIS AFTERNOON OVER PARTS OF THE
CWA. CURRENTLY EXPECTING ABOUT A 30F SPREAD IN HIGH TEMPS FROM THE
EAST TO THE WEST...WITH HIGHS NEAR 60F IN EASTERN COLORADO...AND
IN THE UPPER 20S NEAR NORTON. S/SW FLOW DEVELOPS SATURDAY...WHICH
WILL HELP SOUR OUT THE COLDEST AIR FROM MOST OF THE CWA...THOUGH
EASTERN LOCATIONS WILL STILL LIKELY REMAIN BELOW NORMAL.
SUNDAY...A TROUGH DEVELOPING OVER GREAT BASIN WILL PUSH
EAST...WITH THE MEAN TROUGH AXIS OVER WESTERN KANSAS BY 18Z
SUNDAY. LARGE SCALE ASCENT COMBINED WITH INCREASING MOISTURE AHEAD
OF TROUGH AXIS WILL WILL OVERSPREAD CWA SUNDAY MORNING...QUICKLY
PUSHING E/NE OF THE CWA DURING THE AFTERNOON. ECMWF CONTINUES TO
BE THE WETTEST SOLUTION...THOUGH GFS AT LEAST SHOWS SOME SUPPORT
FOR PRECIP IN THE NE CWA. MAIN CHANGE TO PREVIOUS FORECAST WAS TO
BUMP UP POPS UP IN THE N/NE...AND SPEED UP THE EXIT OF PRECIP
DURING THE AFTERNOON FROM THE WEST TO THE EAST. VERY DRY AIR WILL
ADVECT INTO THE CWA FROM THE WEST DURING THE AFTERNOON...WITH
WINDY CONDITIONS DEVELOPING BY MIDDAY. WE MAY NEED TO ISSUE A RED
FLAG WARNING FOR WESTERN PARTS OF THE CWA AND A WIND ADVISORY FOR
THE MAJORITY OF THE CWA...HOWEVER ITS STILL TOO EARLY FOR THIS
FORECAST CYCLE.
DR
FOR THE PERIOD MONDAY THROUGH THURSDAY...A COLD FRONT WILL MOVE
THROUGH THE REGION ON TUESDAY WITH BREEZY NORTHWEST WINDS AND COLDER
TEMPERATURES. MODELS SHOW SOME LIGHT PRECIPITATION WITH THE FRONT
WHICH MAY END UP NOTHING MORE THAN FLURRIES. TEMPERATURES REBOUND
QUICKLY WITH ABOVE NORMAL TEMPERATURES WEDNESDAY AND THURSDAY.
024
&&
.AVIATION...
931 PM MST THU JAN 19 2012
FOR THE 06Z TAFS...VFR THROUGH THE PERIOD. GUSTY WINDS CURRENTLY
AT KGLD WILL SUBSIDE THE NEXT FEW HOURS. A COLD FRONT WILL MOVE
ACROSS THE REGION LATER THIS MORNING WHICH WILL CAUSE WINDS TO
VEER FROM THE SOUTHEAST TO THE NORTHWEST WITH TIME AND BECOME
GUSTY. GUSTS WILL DIMINISH CLOSE TO 00Z. MID/HIGH CLOUDS WILL
CONTINUE TO OVERSPREAD THE REGION WITH BASES 10K-15K FEET.
BAS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
520 PM EST FRI JAN 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT AS LOW PRESSURE
APPROACHES NEW ENGLAND FROM THE SOUTHWEST. LOW PRESSURE WILL PASS
OUT TO SEA WELL SOUTH OF NEW ENGLAND ON SATURDAY. HIGH PRESSURE
WILL BUILD IN FROM THE NORTHWEST SATURDAY NIGHT AND WILL GRADUALLY
SHIFT INTO THE MARITIMES ON SUNDAY. A WARM FRONT WILL LIFT INTO
SOUTHERN NEW ENGLAND ON MONDAY AND WILL BE QUICKLY FOLLOWED BY A
COLD FRONT MONDAY NIGHT. A TRAILING TROUGH OF LOW PRESSURE WILL
SLOWLY MOVE THROUGH NEW ENGLAND ON TUESDAY. HIGH PRESSURE WILL
BUILD IN FROM THE WEST WEDNESDAY THROUGH THURSDAY..CRESTING OVER
THE AREA ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
VERY LITTLE CHANGE TO THE CURRENT PACKAGE. WITH LOW TDS AND A VERY
DRY SOUNDING...TEMPS WILL TAKE A NOSEDIVE LATER THIS EVENING AS
THE GRADIENT COLLAPSES.
LATEST 3 KM HRRR BRINGS SNOW TO THE FAR WESTERN REACHES OF NH BY
07Z...REACHING MAINE BY AROUND 09Z WHICH APPEARS TOO FAST
CONSIDERING OUR DRY/ARCTIC AIR IN PLACE.
PREV DISC...
CLEAR AND VERY COLD FIRST HALF OF THE NIGHT AS HIGH PRESSURE
CRESTS OVER THE REGION...BUT CLOUDS WILL QUICKLY PUSH BACK INTO
THE REGION AS LOW PRESSURE APPROACHES NEW ENGLAND FROM THE
SOUTHWEST. CLOUDS WILL GRADUALLY LOWER AND THICKEN FROM WEST TO
EAST AND SOME LIGHT SNOW OR SNOW SHOWERS WILL EDGE INTO THE
CONNECTICUT VALLEY AND SOUTHERN NEW HAMPSHIRE TOWARD DAYBREAK. NOT
LOOKING FOR MUCH IN THE WAY OF ACCUMULATION THROUGH 12Z WITH JUST
A DUSTING LIKELY IN FAR SOUTHWEST ZONES. EXPECTING LOWS 5 TO 15
BELOW IN THE NORTH AND 5 BELOW TO 5 ABOVE IN THE SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
LIGHT SNOW WILL PERSIST IN SOUTHERN ZONES MAINLY DURING THE MORNING
HOURS BEFORE TAPERING OFF IN THE AFTERNOON. MODELS NOT PUTTING
OUT MUCH IN THE WAY OF QPF WITH MOST AREAS SEEING A TENTH OF AN INCH
OR LESS BUT A DECENT FLUFF FACTOR MAY PRODUCE UP TO TWO INCHES OF
SNOW IN FAR SOUTHERN NEW HAMPSHIRE. LOOKING FOR AROUND AN INCH OR
LESS ACROSS THE REMAINDER OF THE FORECAST AREA. EXPECT PARTIAL
CLEARING FROM NORTHWEST TO SOUTHEAST LATER IN THE AFTERNOON AS
LOW PRESSURE HEADS OUT TO SEA SOUTH OF NEW ENGLAND. HIGH
TEMPERATURES WON`T GET PAST THE TEENS IN THE NORTH AND MID TEENS
TO LOWER 20S IN THE SOUTH.
COLD HIGH PRESSURE WILL BUILD SOUTHEAST FROM CANADA SATURDAY NIGHT
CLEARING SKIES AND ALLOWING TEMPERATURES TO PLUMMET ONCE AGAIN.
LOOKING FOR LOWS 5 TO 15 BELOW IN THE NORTH AND 5 BELOW TO 10
ABOVE IN THE SOUTH.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRES BRINGS FAIR WX SUNDAY. LOW PRES AND A TRAILING CD FRONT
APPROACH FROM THE W SUNDAY NGT AS A WRM FNT EXTENDING E FROM THE
LOW HAS ANOTHER WEAKER LOW FORM ALONG THE COAST. AS THIS SYSTEM
MOVES TOWARD NEW ENGLAND THE COASTAL LOW WILL COMBINE WITH THE
HIGH TO THE NE TO HELP KEEP COLDER AIR IN OVER THE FCST AREA
ESPECIALLY WHEN THE COASTAL FNT FORMS.
GRADUALLY THOUGH THE WRM AIR STREAMING NE IN AN INCREASINGLY
STRONGER S SW FLOW ALOFT EVENTUALLY ERODES THE CD AIR FORCING SN
TO CHANGE TO MIX THEN TO RA FROM SW TO NE ACROSS THE FCST AREA. SN
AMOUNTS MAY BE LIMITED TO MORE NRN AND NE AREAS AND AMOUNTS, IF
ANY, WOULD LIKELY BE MINIMAL. ICING FROM SLEET AND FREEZING RA MAY
BE MORE OF AN ISSUE DEPENDING ON HOW LONG THE CD AIR HOLDS IN AT
LOW LEVELS AND AT THE SFC.
MODELS VARY ON QPF AMOUNTS BUT AN INCH OF QPF THRU THE EVENT
APPEARS VERY PSBL WITH A MAJORITY OF IT LIKELY FALLING AS RA. THE
GFS IS SHOWING EVEN HIGHER QPF WHILE NAM AND ECMWF SHOW
CONSIDERABLY LESS..AT LEAST THRU 00Z TUESDAY.
THE CD FNT SWEEPS THRU MONDAY NGT WITH PRCP ENDING OR AT LEAST
TAPERING OFF FROM SW TO NE. ON TUESDAY COLDER AIR FILTERS IN AND
AN UPR LEVEL TROF ALONG WITH UPSLOPE LOW LVL FLOW WILL HELP
PRODUCE -SHSN ACTIVITY..ESPECIALLY ACROSS THE N/MT ZONES.
HIGH PRES BRINGS FAIR WX WEDNESDAY. A WEAK UPR LVL SHORT WAVE
TROF MOVING THRU IN AN UPR LVL NW FLOW MAY BRING THE CHC OF SOME
-SHSN ON THURSDAY...MAINLY ACROSS MORE NRN AND NE AREAS. HIGH PRES
TRIES TO BUILD IN BRIEFLY FOR FRIDAY.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR SUNDAY
THRU SUNDAY NGT. USED GMOS FOR REST OF THE LONG TERM FCST... EXCEPT
USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX AND MIN TEMPS.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR TONIGHT WITH SOME AREAS OF MVFR CEILINGS/VSBY
DEVELOPING OVER SOUTHERN NEW HAMPSHIRE TOWARD MORNING. MVFR/IFR
CEILINGS AND VSBY MAINLY IN SOUTHERN AREAS ON SATURDAY...IMPROVING
IN THE AFTERNOON. VFR SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...IFR OR LIFR IN MIXED PRCP
DEVELOPING SUNDAY NGT...CONTINUING THRU MONDAY AND ENDING MONDAY
NGT AS IT TRANSITIONS OVER TO RA.
&&
.MARINE...
SHORT TERM...SCA IN EFFECT THROUGH EARLY EVENING. SCA`S WILL LIKELY
BE NEEDED LATE SATURDAY AFTERNOON THROUGH MIDNIGHT SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...WINDS AND SEAS INCREASE ON
MONDAY...REACHING SCA LEVELS WITH WINDS POSSIBLY REACHING GALE
FORCE...AHEAD OF LOW PRES AND A TRAILING CD FNT. CONDITIONS
BRIEFLY LET UP LATE MONDAY NGT AS THE CD FNT MOVES THRU...ONLY TO
INCREASE TO SCA OR GALE FORCE TUESDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ150>154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
153 AM EST FRI JAN 20 2012
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE EAST THROUGH NEW ENGLAND AND THE GULF
OF MAINE OVERNIGHT. LOW PRESSURE WILL SHIFT INTO THE MARITIMES ON
FRIDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST. HIGH PRESSURE
WILL SHIFT EAST FRIDAY NIGHT AS WEAK LOW PRESSURE APPROACHES NEW
ENGLAND FROM THE SOUTHWEST. LOW PRESSURE WILL PASS OUT TO SEA
SOUTH OF NEW ENGLAND ON SATURDAY. HIGH PRESSURE WILL BUILD IN FROM
THE NORTHWEST SATURDAY NIGHT AND SUNDAY. LOW PRESSURE LIFTING
NORTHEAST OUT OF THE NORTHERN GREAT LAKES WILL DRIVE A COLD FRONT
TOWARD NEW ENGLAND ON MONDAY. THE FRONT WILL CROSS THE AREA MONDAY
NIGHT WITH A TRAILING TROUGH OF LOW PRESSURE MOVING THROUGH THE
REGION ON TUESDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST
ON WEDNESDAY. LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND ON
THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
2AM UPDATE...
SNOWFALL RATES HAVE INCREASED AS LOW PRESSURE HAS DEVELOPED AND
PUSHED OFFSHORE OF MASSACHUSETTS AND INTO THE GULF OF MAINE. SNOW
RATIOS HAVE BEEN IN THE 15 TO 20 TO 1 RANGE... ALLOWING SNOWFALL
TO PILE UP QUICKLY. HAVE SOME CONCERNS THAT AREAS FROM CENTRAL
CUMBERLAND COUNTY EASTWARD THROUGH ANDROSCOGGIN AND KENNEBEC COUNTY
MAY RECEIVE 6 TO 7 INCHES OF SNOW AS HEAVIER SNOW CONTINUES FOR
THE NEXT SEVERAL HOURS. ONSHORE FLOW CONTINUES TO SLING MORE
MOISTURE INTO WESTERN MAINE... AND IS BEING LIFTED ALONG AND
INLAND OF THE COASTAL FRONT. BIGGEST REASON FOR NOT UPGRADING TO A
WINTER STORM WARNING IS DUE TO THE LIMITED SNOWFALL AMOUNTS THAT
HAVE LIKELY FALLEN SO FAR ACROSS KENNEBEC COUNTY AND EASTWARD. THIS
WILL CHANGE QUICKLY AS HEAVY SNOW MOVES EAST. AT THE OFFICE IN
GRAY 1.8 INCHES FELL BETWEEN MIDNIGHT AND 1AM... FOR A TOTAL OF
AROUND 3 INCHES. EXPECT ANOTHER 3 INCHES TO BE POSSIBLE BEFORE THE
ACCUMULATIONS END. SNOWFALL TOTALS WILL FLIRT WITH THE 6 INCH
WARNING CRITERIA... BUT MAY NOT BE WIDESPREAD ENOUGH FOR AN UPGRADE.
0123Z UPDATE...
LATEST RADAR IMAGERY CONTINUES TO SHOW BANDS OF LIGHT SNOW SHOWERS
MOVING ONSHORE FROM THE GULF OF MAINE THIS EVENING. MUCH OF THIS
PRECIPITATION HAS BEEN VERY LIGHT IN NATURE. MEANWHILE...THE
TIMING OF THE STEADY SNOWFALL ENTERING THE FORECAST AREA IS IN
GOOD AGREEMENT WITH THE SHORT TERM FORECAST FROM THE LATEST HRRR
RUN.
WILL KEEP WINTER WEATHER ADVISORIES IN EFFECT FOR THE SOUTHEASTERN
PORTION OF OUR FORECAST AREA. MUCH OF THE PRECIPITATION ENTERING
THE FORECAST AREA REMAINS LIGHT...HOWEVER THERE SHOULD BE MODERATE
SNOWBANDS EMBEDDED WITHIN THIS PRECIPITATION FIELD AS NOTED
ENTERING THE CT/RI COASTLINE. WITH SURFACE WAVE ALREADY BEGINNING
TO FORM NEAR JFK AT 01Z...IN COMBINATION WITH A BRIEF PERIOD OF
ENHANCED VERITICAL MOTION (INCLUDING THE SNOW GROWTH
REGION)...EXPECT AREAS OF 3-6 INCHES SNOWFALLS SOUTHEASTERN ZONES.
HIGHEST SNOWFALL TOTALS SHOULD BE NEAR THE PENOBSCOT RIVER VALLEY.
PREV UPDATE...
ALSO...LATEST HRRR MODEL UPDATE HAS A GOOD HANDLE WITH OCEAN
EFFECT SNOW SHOWERS ENTERING ROCKINGHAM AND YORK COUNTIES THIS
HOUR. HAVE UPPED POPS QUITE A BIT FOR THIS AREA TO ACCOUNT FOR
THIS LOCAL PCPN. -SHSN WILL SPREAD NORTHWARD IN THE NEXT HOUR OR
TWO INTO THE PWM AND POSSIBLY THE NHZ AREAS.
HAVE UPDATED GRIDS TO INCREASE CLOUD COVER OVERNIGHT TO OVERCAST
CONDITIONS WITH ADVISORIES IN EFFECT. REST OF THE GRIDS WILL
REMAIN RELATIVELY UNCHANGED WITH ADVISORIES CONTINUING FOR THE ERN
HALF OF THE FORECAST AREA.
PREV DISC...
WEAK LOW PRESSURE APPROACHING FROM THE WEST WILL BRING A
BRIEF ROUND OF LIGHT TO MODERATE SNOW TO THE REGION OVERNIGHT. LOW
PRESSURE STILL FORECAST TO RE-DEVELOP OVER SOUTHERN NEW ENGLAND
AND MOVE INTO THE GULF OF MAINE BUT MODELS NOT AS STRONG WITH THIS
SYSTEM TODAY AND QPF FOR THE EVENT HAS DROPPED OFF SOMEWHAT.
EXPECT SNOW TO PUSH INTO THE CONNECTICUT VALLEY EARLY THIS EVENING
AND QUICKLY OVER-SPREAD THE REMAINDER OF THE FORECAST AREA THROUGH
MIDNIGHT. WILL STILL BE GOING WITH THE CURRENT ADVISORIES FOR
SOUTHERN AND COASTAL MAINE EXCLUDING YORK COUNTY FOR THE OVERNIGHT
HOURS. HAVE NOT CHANGED ACCUMULATIONS MUCH FROM YESTERDAY WITH 2
TO 4 INCHES OF ACCUMULATION EXPECTED ACROSS MUCH OF NEW HAMPSHIRE
AND EXTREME SOUTHWEST MAINE. REMAINDER OF SOUTHERN AND COASTAL
MAINE WILL SEE 3 TO 6 INCHES OF SNOWFALL THROUGH EARLY FRIDAY
MORNING. EXPECT SNOW TO QUICKLY END IN NEW HAMPSHIRE AND SOUTHWEST
MAINE BEFORE DAYBREAK ON FRIDAY. SHOULD BE A MUCH WARMER NIGHT
WITH TEMPS IN THE LOWER TO MID TEENS IN THE NORTH AND MID TEENS TO
LOWER 20S IN THE SOUTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM SATURDAY/...
HIGH PRESSURE BUILDING IN FROM THE WEST WILL BRINGING CLEARING
SKIES AND MOSTLY SUNNY WEATHER TO MOST OF THE AREA ON FRIDAY.
SHOULD SEE MORNING CLOUDS CLEARING OUT OF THE MOUNTAINS AND FAR
EASTERN ZONES BY NOON. EXPECT TEMPS TO RANGE THROUGH THE TEENS IN
THE NORTH AND THROUGH THE 20S AND LOWER 30S IN THE SOUTH.
MID HIGH LEVEL CLOUDINESS WILL BE ON THE INCREASE FRIDAY NIGHT AS
WEAK OVER-RUNNING PATTERN SHIFTS INTO THE NORTHEAST AHEAD OF LOW
PRESSURE MOVING INTO THE MID ATLANTIC STATES. WILL INTRODUCE
LOW CHANCE POPS INTO SOUTHERN NEW HAMPSHIRE AFTER MIDNIGHT BUT
EXPECT LITTLE IF ANY ACCUMULATION THROUGH SATURDAY MORNING. LOW
TEMPS WILL RANGE FROM ZERO TO 10 BELOW IN THE NORTH AND 5 TO 15
ABOVE IN THE SOUTH.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
MODELS TRACK WEAK SFC LOW OFF THE MID ATLANTIC COAST E AND OUT TO
SEA ON SATURDAY. THIS WILL PRODUCE -SN ACROSS THE FCST AREA WITH
LGT ACCUMULATIONS PSBL. HIGHEST CHC OF SN AND HIGHEST
ACCUMULATIONS OVER MORE SRN AREAS CLOSER TO THE LOW WITH LOWEST
CHC AND ACCUMULATION TO THE N. VERTICAL TEMP PROFILE CD ENOUGH TO
SUPPORT ALL SN FOR THIS EVENT.
THE LOW MOVES OUT TO SEA FAIRLY QUICKLY WITH -SN ENDING FROM W TO E
IN THE AFTERNOON. HIGH PRES FOLLOWS WITH FAIR WX SATURDAY NGT AND
SUNDAY. THE HIGH MOVES OUT TO THE E SUNDAY NGT AS THE UPR LVL
RIDGE CRESTS ALONG THE E COAST. A STRONG UPR LVL CUTOFF SYSTEM
OVER THE UPPER MID WEST CREATES A FAIRLY STRONG SFC LOW OVER THE
GREAT LAKES THAT WILL TRACK SLOWLY E WITH A TRAILING CD FNT
EXTENDING TO THE S. AHEAD OF THIS SYSTEM INCREASING S SW FLOW FROM
SFC TO H5 BRINGS IN MUCH WARMER AIR ALOFT AND EVENTUALLY TO THE
SFC AS PRCP EVENTUALLY MOVES IN LATE SUNDAY NGT AND MONDAY. MAY BE
SOME -SN OR MIXED SN AND ICE TO BEGIN WITH BUT GRADUALLY PRPC
CHANGES OVER TO RA FOR MONDAY AND MONDAY NGT THOUGH SOME -FZRA
STILL PSBL ACROSS THE NRN TIER OF ZONES WHERE IT WILL TAKE THE
LONGEST TO SCOUR OUT THE CD AIR AT THE SFC.
THE CD FNT MOVES THRU BY TUESDAY MORNING WITH COLDER AIR FOLLOWING
THE FNT AS TEMPS LIKELY TO FALL DURING THE DAY AFTER MILD PREDAWN
READINGS. A SECONDARY UPR LVL TROF MOVES THRU WHICH MAY PRODUCE A
FEW -SHSN BUT THE N/MT ZONES HAVE THE BEST CHC OF -SHSN DUE TO
DEVELOPING UPSLOPE FLOW IN THE CD AIR ADVECTION BEHIND THE FNT.
HIGH PRES BRINGS FAIR WX WEDNESDAY FOLLOWED BY A FAST MOVING SFC
LOW THAT WILL TRACK TO OUR S BRINGING THE CHC OF -SN WEDNESDAY NGT
AND THURSDAY.
GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR SATURDAY
THRU SATURDAY NGT. USED GMOS FOR REST OF THE LONG TERM FCST...
EXCEPT USED A BLEND OF GFS40 AND MEX MOS GUIDANCE FOR MAX AND MIN
TEMPS.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...MVFR/IFR CEILINGS AND VSBY DEVELOPING THIS
EVENING...IMPROVING TO VFR ON FRIDAY. VFR FRIDAY NIGHT.
LONG TERM /SATURDAY THROUGH MONDAY/...IFR PSBL WITH -SN SATURDAY.
IFR OR LIFR PSBL WITH MIXED PRCP DEVELOPING LATE SUNDAY NGT AND
CONTINUING THRU MONDAY.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORY IN EFFECT THIS EVENING THROUGH FRIDAY.
LONG TERM /SATURDAY THROUGH MONDAY/...CONDITIONS BELOW SCA LEVELS
SATURDAY THRU SUNDAY NGT...THEN INCREASE TO SCA LEVELS OR PSBL
GALES MONDAY INTO MONDAY NGT IN STRENGTHEN S SW FLOW AHEAD OF THE
CD FNT. WINDS SHIFT TO THE W AS THE FNT MOVES OUT TO SEA AND CONT AT
SCA OR PSBL GALE LEVELS ON TUESDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
MEZ012>014-019>022-024>028.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ150>154.
&&
$$
NEAR TERM UPDATE... KIMBLE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
700 PM EST SAT JAN 21 2012
UPDATED FOR 00Z AVIATION DISCUSSION
.SYNOPSIS...
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR LKS BTWN ARCTIC VORTEX CENTERED OVER HUDSON BAY ASSOCIATED
WITH RECENT INTENSE CHILL AND PROGRESSIVE UPR RDG SHIFTING E THRU
THE NRN PLAINS. SFC/H85 RDG AXIS HAS BROUGHT RELATIVELY TRANQUIL WX
TO THE FA TDAY WITH MID LVL DRY AIR SHOWN ON THE 12Z GRB RAOB. TEMPS
HAVE RISEN STEADILY FM MRNG LOWS ARND -25F OVER THE INTERIOR W. SOME
LES LINGERS EARLY THIS AFTN OVER THE KEWEENAW AND IN AREAS WELL E OF
MQT WITH H85 TEMPS STILL AOB -15C...BUT BACKING LLVL FLOW TO THE SW
THAT SIGNALS A RETREAT OF THE ARCTIC AIR IS CAUSING THE SHSN TO
DRIFT TO THE NE. IN FACT...WAD MID CLD BEST DEPICTED BY THE RH SHOWN
ON THE 12Z NAM 290-295K ISENTROPIC SFCS/H6-7/ AND WELL IN ADVANCE OF
SHARP H85 WARM FNT PUSHING THRU THE NRN PLAINS IS ALREADY MOVING FM
NRN MN INTO THE WRN CWA. BUT GENERALLY DRYNESS OF THE 12Z INL RAOB
IS PREVENTING ANY PCPN. SOME -SN IS SHOWING UP NEAR LK WINNIPEG. TO
THE S...THERE IS QUITE A BIT OF LO CLD S OF THE HI CENTER IN
WI...AND THIS ST/SC IS STARTING TO STREAM NWD INTO SW MN. FARTHER
W...12Z H85 TEMPS WERE UP TO 6C IN THE LEE OF THE ROCKIES BEHIND THE
WARM FNT. A VIGOROUS SHRTWV IS DIGGING SEWD INTO THE SW STATES.
THERE HAVE BEEN A FEW LTG STRIKES NEAR THE TRACK OF THIS
FEATURE...AND NEARBY PIREPS INDICATE H3 WIND SPEEDS UP TO 175KT
WITHIN SUPPORTING UPR JET THAT IS WELL DEFINED ON WV IMAGERY.
&&
.SHORT TERM DISCUSSION /TNGT AND SUN/...
MAIN FCST CONCERNS IN THIS PERIOD ARE IMPACT OF RETURNING WARM AIR
IN VIGOROUS WAD PATTERN THAT WL SET UP IN RETURN SLY FLOW BTWN
DEPARTING HI PRES RDG TO THE E AND DVLPG LO PRES IN THE PLAINS
ASSOCIATED WITH VIGOROUS HGT FALLS IN ADVANCE OF SHRTWV NOW MOVING
INTO THE SW STATES.
TNGT...WITH STRENGTHENING LLVL SLY FLOW...EXPECT ANY LES NEAR LK SUP
TO DRIFT OFFSHORE BY LATE IN THE AFTN. SINCE THE AIRMASS WL STILL BE
COLD ENUF FOR LES EARLY WITH H85 TEMPS ARND -12C...GOING FCST OF
SOME LK CLD/SHSN OFF LK MI INTO THE FM ISQ-ERY STILL LOOKS ON TRACK.
BUT THIS PCPN SHOULD DIMINISH AS TEMPS RISE THRU THE NGT. IN FACT...
H85 WIND INCRSG UP TO 50KTS TOWARD WRN LK SUP BY 12Z SUN ARE FCST TO
PUSH H85 TEMPS NEAR 0C IN THAT AREA TOWARD DAYBREAK. THIS
STRENGTHENING SSW FLOW WL ALSO DRAW THE LO CLD NOW WELL TO THE S
INTO THE WRN AND CNTRL CWA. BUT DOWNSLOPE NATURE OF THE FLOW OVER
THE W AND NCNTRL SHOULD RESULT IN SOME DISSIPATION OF THIS CLD
COVER. TO THE NW...THE AREA OF SN NOW NEAR LK WINNIPEG WL LIKELY
SHIFT NEAR ISLE ROYALE WITH PERSISTENT ISENTROPIC ASCENT SHOWN ON
THE 290-295K SFCS...MORE SATURATED PROFILE DOWN TO THE SFC...AND
INCRSG UPR DVGC IN RRQ OF H3 JET MAX IN ONTARIO AND IN EXIT REGION
OF ANOTHER UPR JET EMERGING ON THE E SIDE OF DEEPENING UPR TROF IN
THE PLAINS. WITH 5-6K FT DEEP DRY WEDGE SHOWN ON FCST SDNGS FOR
CMX...SUSPECT THE BULK OF THIS PCPN WL REMAIN TO THE NW OF THE
KEWEENAW. SO CUT POPS INTO THE CHC CATEGORY FOR THAT AREA WITH HIER
POPS TO THE N. EXPECT THE LOWEST TEMPS EARLY TNGT...WITH THE MERCURY
RISING LATER AS INCRSG S WIND ADVECTS MORE LLVL MSTR INTO THE AREA.
TENDED TO LOWER EARLY EVNG TEMPS OVER THE INTERIOR CNTRL BEFORE
ARRIVAL OF THICKER CLD COVER/ONSET OF STRONGER WINDS CAUSES TEMPS TO
RISE OVERNGT.
SUN...THE WX WL BE DOMINATED BY THE ARRIVAL OF INCRSG LLVL MSTR IN
STEADY SSE WIND BTWN DEPARTING HI PRES RDG AND DVLPG LO IN THE
PLAINS. ALTHOUGH CONTINUED WAD WL TEND TO RESULT IN INCRSG MID LVL
MSTR AS WELL...MODEL GUIDANCE INDICATES A PERSISTENT DRY WEDGE
CENTERED ARND H85 THRU THE DAY BTWN THE LLVL AND HIER LVL
MOISTENING. MAINTAINED MAINLY SCHC POPS FOR LARGER SCALE PCPN...HIER
TO THE NW. ANY PCPN WL LIKELY BE SN AND PSBLY SLEET WITH WARM
WEDGE/H85 TEMPS POTENTIALLY UP TO 5C IN THE DRY LYR THAT MIGHT MELT
SN FLAKES ABV RESIDUAL COLD AIR JUST ABV THE SFC...WHERE TEMPS ARE
FCST TO REMAIN AS LO AS -6C TO -8C. ALSO INCLUDED MENTION OF FZDZ
MAINLY OVER THE SCNTRL WHERE GUIDANCE SHOWS INCRSG SFC DEWPTS IN
AREA OF UPSLOPE SSE FLOW. LIMITING FACTOR WL BE FAIRLY HI SFC DEWPT
DEPRESSIONS NOW OBSVD TO THE S/STRONG WINDS THAT MIGHT MAINTAIN A
SLIGHT INVERTED V LLVL THERMAL/MSTR PROFILE.
.LONG TERM /SUNDAY NIGHT THROUGH NEXT SATURDAY/...
DEEPENING LOW PRESSURE OVER THE UPPER LAKES AND MIXED PRECIPITATION
ISSUES IS THE MAIN CONCERN OF THE LONG TERM.
BY SUNDAY EVENING...SHORTWAVE TROUGH WITH AT LEAST TWO EMBEDDED
SHORTWAVES/PV ANOMALIES WILL BE OVER THE CNTRL PLAINS. MAJORITY OF
MODELS AGREE IN THIS IDEA. 12Z NAM IS ON ITS OWN SHOWING STRONGER
PIECE OF ENERGY SHOOTING NORTH INTO MN. ALL OTHER GUIDANCE...SAVE
THE SREF WHICH HAS MANY NAM MEMBERS WITHIN IT...KEEPS STRONGEST
ENERGY MORE OVR SOUTHERN PLAINS. BASED ON POSITION OF UPPER JET
AHEAD OF TROUGH...THINK NAM IS TOO STRONG WITH SHORTWAVE OVR MN.
THIS LEADS TO A MUCH FARTHER NORTH TRACK TO SFC LOW ON MONDAY
(NORTHERN LK SUPERIOR MONDAY MORNING INSTEAD OF OVR SOUTHERN LK
MICHIGAN). SO AS MUCH AS WOULD HAVE LIKED TO HAVE THE HIGHER
RESOLUTION NAM THERMAL PROFILES TO USE IN THIS FCST...HAVE TO
DISCOUNT THE NAM AT THIS TIME. SHOULD NOTE THAT IT APPEARS THE 12Z
NAM IS TRENDING TOWARD MAJORITY OF OTHER MODELS...SO MAYBE IT WILL
BE MORE USEFUL IN 24 HRS. MOVING ON THAT LEAVES THE ECMWF AND UKMET
IDEA (WHICH HAVE BEEN CONSISTENT AND PREFERRED WITH THIS SYSTEM FOR
SOME TIME NOW) AS WELL AS THE GFS WHICH BEGAN TRENDING TOWARD
ECMWF/UKMET IDEA WITH THE 18Z RUN ON 1/20. CANADIAN ALSO PRETTY MUCH
IN LINE NOW AS WELL...THOUGH RUN-TO-RUN CONSISTENCY WITH SFC LOW
TRACK ON MONDAY STILL NOT THE GREATEST. SHOULD NOTE...12Z GFS DID
TREND A BIT TOWARD NAM IDEA AND WAS NOT PREFERRED BY HPC. 12Z
ECMWF/CANADIAN/UKMET REMAIN CONSISTENT WITH PREVIOUS MODEL RUNS.
APPEARS THAT THOUGH THERE IS SOME INTERACTION WITH NORTHERN STREAM
LATER MONDAY AND MONDAY NIGHT...THIS SYSTEM WILL BE MAINLY SOUTHERN
STREAM ORIGIN. WITH THAT WILL COME GOOD TAP OF GULF MOISTURE WITH
PWATS OVR 250 PCT OF NORMAL BY 12Z MONDAY OVR MOST OF THE CWA.
POSITION OF H85 TROUGH AND SRLY H85 WINDS PUT STRONGEST H85 THETA-E
ADVECTION OVER EAST HALF OF CWA BTWN 09Z-15Z MONDAY. HEAVIEST QPF IS
FCST OVR CNTRL AND EAST CWA. RUN TOTAL QPF THROUGH 00Z TUESDAY (WHEN
DEEPER MOISTURE/HIGHER PWATS SHIFT TO THE NORTHEAST INTO
ONTARIO/QUEBEC) RANGE FROM 0.50-0.90 OF AN INCH WITH CANADIAN UP OVR
1 INCH...HEAVIEST CNTRL CWA DUE TO DEFORMATION ON BACK EDGE OF
H85-H7 LOWS AND IT IS ALSO WHERE THERE IS A HINT OF A TROWAL HANGING
BACK OVR THE AREA AS H85-H7 LOWS MAINTAIN STEADY STRENGTH WHILE
HEADING INTO ONTARIO.
LOW-LEVEL THERMAL PROFILES WILL BE CRITICAL COMPONENT WITH THIS
SYSTEM...ESPECIALLY THROUGH NOON ON MONDAY. BASED ON 0C H85
LINE...RAIN WILL BE MAIN PTYPE EAST OF MARQUETTE AND DICKINSON
COUNTIES...WITH SNOW TO THE WEST. TROUBLE IS THAT SFC-BLYR TEMPS
WILL BE VERY CLOSE TO FREEZING AS THE RAIN ARRIVES FM THE SOUTH LATE
SUNDAY NIGHT. COULD EVEN BE SLEET OR SNOW RIGHT AT THE ONSET OF
PRECIPITATION SUNDAY NIGHT AS WELL AS COLD AIR ALOFT SLOWLY EVADES.
BELIEVE FREEZING RAIN WILL BE BIGGEST CONCERN TOWARD DAYBREAK MONDAY
AND THROUGH ABOUT MID MORNING...THEN BLYR WARMING IN THE EAST SHOULD
CHANGE PTYPE TO JUST RAIN. DUE TO COLD SPELL LATELY...WARMING OF
GROUND SFC TEMPS WILL LAG THE AIR TEMPS...SO MAY BE SITUATION WHERE
TEMPS AT OBSERVATION PLATFORMS (ASOS/AWOS/RAWS) ARE IN THE MID 30S
BUT THERE IS STILL ICING OCCURRING ON COLDER UNTREATED SURFACES.
UNFORTUNATELY...THESE THERMAL QUESTIONS ABOUND THE FIRST PART OF
MONDAY WHEN BULK OF HEAVIER QPF IS FCST WITH WARM AIR ADVECTION
ALOFT AT ITS PEAK. DO THINK THERE IS A GREATER THAN 50 PCT CHANCE
OF SIGNIFICANT ICING LATE SUNDAY NIGHT AND MONDAY MORNING...
ESPECIALLY AWAY FM THE IMMEDIATE SHORELINES OF LK SUPERIOR AND LK
MICHIGAN.
EVENTUALLY...BLYR WARMING WILL RESULT IN MOSTLY RAIN BY LATE MORNING
EAST OF MUNISING TO MENOMINEE AS SFC LOW IS FCST TO DEEPEN AND MOVE
FM SOUTHEAST WI TO SCNTRL UPR MI AND EVENTUALLY OUT OVR SOUTHEAST LK
SUPERIOR BY MONDAY EVENING. SITUATION COULD BECOME VERY FAVORABLE
FOR HEAVIER SNOW OVR CNTRL CWA THOUGH...MAINLY OVR HIGHER TERRAIN
JUST WEST OF MARQUETTE INTO PORTIONS OF KEWEENAW AND AS FAR SOUTH
AS WI BORDER...EVENTUALLY SPREADING INTO ALGER AND DELTA COUNTIES BY
LATE AFTN. PRIMARY DRIVER FOR POTENTIALLY HEAVIER SNOW IS VERY TIGHT
H85 TEMPERATURE GRADIENT OVR CNTRL CWA/INCREASING DEFORMATION ON
WEST SIDE OF CLOSED OFF H85-H7 LOWS AND LINGERING TROWAL REGION MOST
NOTED 950-750MB. NORTHERN STREAM WAVE DIGGING INTO THE SOUTHERN
STREAM SYSTEM WILL ALSO LEAD TO STRONGER DEFORMATION PRECIP REGION.
HEADLINES...GIVEN THIS SYSTEM WILL BE AFFECTING THE AREA ON A MONDAY
WHEN THERE IS LOT OF TRAVEL WITH WORK/SCHOOL/ETC AND SINCE THIS
SYSTEM HAS POTENTIAL TO BE HIGHER IMPACT DUE TO AMOUNT OF MOISTURE
AVAILABLE...THINK GOING WITH A WATCH RIGHT NOW IS A GOOD IDEA. MAIN
ISSUE FOR ALGER AND DELTA COUNTY EASTWARD IS THE INITIAL ICE THREAT
LATER SUNDAY NIGHT INTO MONDAY MORNING. A MIXED BAG OF ICE AND SNOW
AND SOME SLEET IS MAIN ISSUE FOR AREAS OVR CNTRL UPR MI...BASICALLY
MARQUETTE AND DICKINSON/MENOMINEE COUNTIES. FARTHER WEST...IT WOULD
BE GENERALLY A SNOW EVENT. ONLY PLACE WHERE WINTER STORM WATCH WILL
NOT BE ISSUED IS FAR WEST CWA AS MODELS ARE VERY INSISTENT IN SHOWING
THEM BEING MISSED BY INITIAL WARM AIR ADVECTION PRECIPITATION LATE
SUNDAY NIGHT/MONDAY MORNING AND GENERALLY KEEPING THE PRIMARY
DEFORMATION AXIS TO THE EAST OF THOSE AREAS ON MONDAY AFTN/MONDAY
EVENING. WATCHES WILL RUN FM LATE SUNDAY NIGHT THROUGH MONDAY
EVENING FOR MARQUETTE AND DICKINSON COUNTIES WESTWARD BUT WILL KEEP
ENDING TIME SHORTER FARTHER EAST AS MOST PTYPE BY AFTN WILL BE
RAIN/DRIZZLE AND SNOW SHOULD NOT BE SIGNIFICANT...ESPECIALLY IN FAR
EAST TOWARD KERY.
LK EFFECT...POSSIBLY ENHANCED BY DEPARTING SYSTEM WILL TARGET NW
FLOW AREAS LATER MONDAY NIGHT INTO TUESDAY MORNING. GUSTY NW WINDS
WILL LEAD TO BLSN ISSUES AS WELL. WILL GO AHEAD AND RUN WATCHES
THROUGH 12Z WHERE LK EFFECT/BLSN WILL BE HAZARD LATER MONDAY NIGHT.
COORD WITH DLH...GRB...APX AND ALSO HPC ON THIS SYSTEM.
FOR THE EXTENDED /TUESDAY NIGHT THROUGH SATURDAY/...
A SLIGHTLY AMPLIFIED FLOW WITH A BROAD EASTERLY TROUGH AND WEAK
WESTERN RIDGE WILL DEVELOP AND LEAD TO A GENERALLY SUSTAINED WNW/NW
FLOW OVER THE UPPER GREAT LAKES THROUGH MOST OF THE PERIOD. A SERIES
OF SHORTWAVE TROUGHS AND RIDGES WILL PROGRESS ALONG THE WESTERN SIDE
OF THE EASTERN TROUGH AND ALLOW FOR PERSISTENT BUT SMALL PRECIP
CHANCES. HOWEVER...THERE IS DISAGREEMENT IN THE GUIDANCE WITH THE
TIMING OF EACH OF THESE PULSES.
CAA ON THE BACKSIDE OF MONDAYS DEPARTING LOW WILL CEASE TUESDAY
EVENING AS SFC/850MB WINDS BACK TO THE WEST WITH THE PASSAGE OF A
SHARP MID LEVEL RIDGE. SOME LES WILL REMAIN EARLY IN THE EVENING
ACROSS EASTERN PARTS OF THE CWA...AND THROUGHOUT THE EVENING IN THE
KEWEENAW PENINSULA. THERE WILL BE A BRIEF BREAK AFTER THE RIDGE
PASSES BEFORE THE FIRST IMPULSE DIGS SOUTHEAST OUT OF SOUTH CENTRAL
CANADA WEDNESDAY NIGHT THROUGH THURSDAY. THE GFS AND ECMWF WERE IN
DECENT AGREEMENT WITH THE STRENGTH OF THIS WAVE...BUT THE 12Z GFS
HAS TRENDED STRONGER. AT THE SAME TIME...THE GEM HAS NEARLY ZONAL
FLOW WEDNESDAY BEFORE DEVELOPING A WEAK SHORTWAVE THURSDAY
AFTERNOON. ALL THREE MODELS DO KEEPS MUCH OF THE PRECIPITATION OVER
LAKE SUPERIOR AND THE EASTERN HALF OF THE CWA...SO WILL KEEP CHANCES
IN THE FORECAST FOR WEDNESDAY NIGHT. ONLY A VERY SHORT PERIOD OF
LES...6 TO 12 HOURS...IS POSSIBLE FOR WNW FAVORED WIND BELTS
THURSDAY AS BOTH THE GFS AND ECMWF ARE VERY AGGRESSIVE IN BRINGING
DRY AIR AND A SHARP LOW LEVEL RIDGE ACROSS LAKE SUPERIOR THURSDAY
EVENING. EVEN MORE...RAPIDLY LOWERING INVERSION HEIGHTS TO BELOW
3KFT AND TEMPERATURES BELOW THE INVERSION GENERALLY >-12C WILL LOWER
GOOD LES CHANCES.
MORE DISAGREEMENT RESIDES WITH THE NEXT WAVE PROGGED TO PASS TO THE
NORTH OF THE CWA ON FRIDAY. THE 00Z ECMWF SHOWS AN OPEN WAVE AT
500MB OVER WESTERN ONTARIO 18Z FRIDAY...WHEREAS THE GFS HAS A CLOSED
500MB LOW OVER NORTHERN MANITOBA. THE GFS HAS BEEN RATHER CONSISTENT
WITH THIS FEATURE FOR THE LAST DAY WHILE THE ECMWF PULLED THE TROUGH
FURTHER SOUTH. ATTM...THE GFS SEEMS TO BE THE BETTER CHOICE...THOUGH
BOTH HAVE A COLD FRONT MOVING ACROSS CWA DURING THE DAY FRIDAY. AS
THIS OCCURS...THE SURFACE LOW WILL BE TRACKING JUST AHEAD OF THE
MIDLEVEL LOW ALONG THE SOUTHWEST SHORE OF HUDSON BAY. NEAR THE CWA
THE FORCING WILL BE PURELY FRONTAL...WITH THE STRONGEST BAND OF
FRONTOGENESIS NORTH OF LAKE SUPERIOR BETWEEN 500 AND 700MB.
THERE IS ALSO CONCERN ABOUT THE LACK OF MOISTURE WITH THIS FRONTAL
PASSAGE AS AIR AHEAD OF THE FRONT WILL BE PULLED FROM DRY
CONTINENTAL AIR IN THE LEE OF THE NORTHERN ROCKIES.
AIR BEHIND THE COLD FRONT ON FRIDAY WILL BE OF WARMER PACIFIC
ORIGIN...WITH INVERSION HEIGHTS DROPPING INTO THE EVENING. NW FLOW
LES WILL STILL BE A POSSIBILITY...BUT WILL BE GREATLY SUPPRESSED BY
LOW INVERSIONS AND HIGH 850/925MB TEMPERATURES. AIR OF MORE ARCTIC
ORIGIN COMES IN BEHIND A SECONDARY COLD FRONT ON SATURDAY
MORNING...THOUGH MOISTURE IS LACKING WITH THIS FRONT AS WELL. WILL
STAY GENERALLY DRY IN TERMS ON POTENTIAL FRONTAL AND LES PRECIP
EXCEPT ALONG THE KEWEENAW PENINSULA.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
EXPECT VFR CONDITIONS THIS EVENING...THEN STEADY S WIND WILL ADVECT
ABUNDANT LOW LEVEL MOISTURE AND LOW CLOUDS INTO UPPER MI LATE
TONIGHT THROUGH SUNDAY MORNING. EXPECT DOWNSLOPING WIND COMPONENT AT
IWD/CMX MAY BREAK UP SOME OF THE CLOUDS TIL LATE TONIGHT OR SUNDAY
MORNING. EXPECT A BETTER CHANCE OF MVFR CIGS IMPACTING KSAW WITH
MORE OF AN UPSLOPE WIND COMPONENT.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
OPTED TO UPGRADE GALE WATCH TO A WARNING OVER THE E PART OF LK SUP
FOR LATE TONIGHT THRU SUN WITH STRENGTHENING SLY FLOW UNDER
SHARPENING PRES GRADIENT BETWEEN DEPARTING HI PRES RIDGE TO THE E
AND DEVELOPING LO IN THE PLAINS. A NNW GALE IS LOOKING MORE LIKELY
FOR MON NIGHT/TUE AS DEEPENING LO PRES TRACKING JUST TO THE E MOVES
INTO SE CANADA. THE WINDS WILL DIMINISH BY TUE NIGHT WITH APPROACH
OF HI PRES RIDGE. ALTHOUGH ANOTHER LO PRES MAY IMPACT THE LAKE ON
THU...NO GALES APPEAR LIKELY ATTM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT
FOR MIZ001-003-004.
WINTER STORM WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY
NIGHT FOR MIZ005-006-011>014-085.
WINTER STORM WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY
AFTERNOON FOR MIZ007.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST SUNDAY FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
EXTENDED...TK
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
646 AM EST FRI JAN 20 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...(330 AM EST FRI JAN 20 2012)
AN UPPER LEVEL DISTURBANCE WILL BRING ANOTHER ROUND OF SNOW TO THE
AREA TODAY INTO TONIGHT...AFFECTING THE FRIDAY EVENING COMMUTE.
COLD AIR WILL EXIT THE AREA SATURDAY AND THEN THE FOLLOWING WORK
WEEK WILL SEE ABOVE NORMAL TEMPERATURES WITH RAIN EXPECTED SUNDAY
NIGHT INTO MONDAY AND AGAIN IN THE MIDDLE OF THE WEEK.
&&
.SHORT TERM...(330 AM EST FRI JAN 20 2012)
(TODAY THROUGH SATURDAY)
NO SIGNIFICANT CHANGES WERE MADE TO THE INHERITED FORECAST. THE
WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SOUTHERN HALF OF THE
FORECAST AREA FOR 3 TO 5 INCHES OF SNOW TODAY AND TONIGHT.
ADVISORY HEADLINES STILL LOOK ON TRACK. ALTHOUGH MOST OF THE SNOW
SHOULD FALL AROUND THE GENERAL TIME OF THE AFTERNOON COMMUTE...
MODEST SNOWFALL RATES AROUND HALF AN INCH PER HOUR WILL MINIMIZE
IMPACTS. THE GENERAL SETUP /A SHALLOW DGZ WAY UP ABOVE 10KFT/
CERTAINLY DOES NOT FAVOR HEAVY SNOWFALL. GIVEN A DEEP SATURATED
LAYER BENEATH THE DGZ ALONG WITH DEEP UPWARD VERTICAL MOTION...SNOW
RATIOS SHOULD BE QUITE LOW /10-15:1/...WHICH IS SUPPORTED BY THE
SNOW TOOL. THE RELATIVELY DENSE FLAKES COMBINED WITH LIGHT WINDS
SHOULD PREVENT SIGNIFICANT VISIBILITY RESTRICTIONS FROM BEING AN
ISSUE. SNOW IS EXPECTED TO END FRIDAY NIGHT SHORTLY AFTER MIDNIGHT.
SNOW TOTALS STILL LOOK TO BE 4-5 INCHES ALONG AND SOUTH OF I-96...
WITH GENERALLY 2-4 INCHES BETWEEN US-10 AND I-96.
&&
.LONG TERM...(400 AM EST FRI JAN 20 2012)
(SUNDAY THROUGH THURSDAY)
THERE ARE TWO STORM EVENTS TO WATCH THIS COMING WEEK. THE
FIRST IS THE SYSTEM SUNDAY NIGHT INTO TUESDAY MORNING. THEN
THERE IS THE POTENTIAL FOR ANOTHER SIGNIFICANT STORM IN THE
WEDNESDAY TO THURSDAY TIME FRAME.
ZONAL FLOW RETURNS THIS COMING WEEK...DISPLACING THE ARCTIC AIR. A
RETROGRADING UPPER LOW OVER CENTRAL CANADA DUMPS MOST OF ITS ENERGY
INTO A DEVELOPING SYSTEM OVER THE GULF OF ALASKA BY MONDAY. THAT
RESULTS IN A MORE ZONAL FLOW OVER THE CONUS UNTIL THE PACIFIC LONG
WAVE TROUGH MOVES EAST INTO THE CENTRAL UNITED STATES (BEYOND OUR
FORECAST RANGE).
THAT IN TURN LOCKS THE ARCTIC AIR WELL NORTH IN CENTRAL CANADA AND
ALASKA MOST OF THIS COMING WEEK AND WILL BRING ABOVE NORMAL
TEMPERATURES. WITH THIS PATTERN WE WILL SEE FREQUENT PERIODS OF
PRECIPITATION AS THE STORM TRACK WILL REMAIN NEAR MICHIGAN.
AS FOR THE SUNDAY NIGHT AND MONDAY STORM...CONTINUITY IS BEST WITH
THE ECMWF THE FOUR MOST RECENT RUNS OF THE ECMWF SHOW A VERY SIMILAR
SOLUTION... WHICH IS A MUCH MORE WRAPPED UP SYSTEM THAT TAKES UNTIL
TUESDAY MORNING TO CLEAR THE AREA. IT IS ALSO SLOWER TO BRING THE
PRECIPITATION INTO THE AREA SUNDAY. I FAVORED THE ECMWF SO I PUSHED
THE POPS TOWARD A SLOWER SOLUTION OF THE ECMWF. THIS WOULD BRING A
SIGNIFICANT AMOUNT OF RAIN TO THE AREA AS THE SURFACE LOW TRACKS
WELL WEST OF SOUTHWEST LOWER MICHIGAN. THERE WOULD BE AROUND A HALF
INCH OF RAIN WITH THIS SYSTEM NO MATTER WHICH MODEL IS CORRECT.
HOWEVER WITH THE ECMWF BEING SLOWER TO START THE PRECIPITATION AND A
TOUCH WETTER WE COULD SEE A HALF TO ONE INCH OF QPF. THE PCPN THAT
FALLS MON AFTERNOON INTO MONDAY NIGHT WOULD BE RAIN TO SNOW ON
EITHER MODEL. THE ECMWF WOULD PRODUCE MEASURABLE SNOW MONDAY NIGHT
ACROSS THE CWA.
THE NEXT SYSTEM IN THE WED/THURSDAY TIME FRAME IS A PHASING ISSUE
WITH THE NORTHERN AND SOUTHERN STREAM. THE LATEST VERSION OF THE GFS
PHASES THE NORTHERN AND SOUTHERN STREAM WAVES WHILE ECMWF DOES NOT.
NEITHER MODEL HAS A DECENT CONTINUITY WITH THIS SYSTEM SO WE WILL
STICK WITH LOW POPS FOR NOW AND SEE HOW THIS PLAYS OUT.
NO MATTER WHAT HAPPENS TEMPERATURES WILL RUN WELL ABOVE NORMAL ALL
WEEK.
&&
.AVIATION...(645 AM EST FRI JAN 20 2012)
THE LOW CLOUDS (MVFR CIGS FROM LAKE EFFECT CLOUDS) HAVE DRIFTED TO
THE I-69 AREA AS OF 1130Z. THESE WILL COVER THE CWA BY 13Z ONLY TO
DISSIPATE BY LATE MORNING LAKE CLOUD LEVEL WINDS BECOME MORE SOUTH
SOUTHEAST (NOT OFF LAKE MICHIGAN). I EXPECT ALL TAF SITES (JXN
SHOULD BE IN THE CLOUDS SOON) WILL BE MVFR FOR SEVERAL HOURS THIS
MORNING.
THE SNOW AREA WILL MOVE INTO SOUTHWEST LOWER MICHIGAN BY MID
AFTERNOON. MY TIMING WAS BASED ON THE HRRR TIMING AND SOME
CONSIDERATION WAS GIVEN TO THE 09Z RUN ISENTROPIC LIFT NEAR 700 MB.
THIS SEEMS TO MATCH THE PROGRESSION OF THE SNOW ACROSS IOWA EARLY
THIS MORNING NICELY. THE HEAVIEST SNOW WILL BE BETWEEN 5 PM AND 9 PM
THIS EVENING. JXN SHOULD BE THE LAST SITE TO LOSS THE SNOW. ONCE THE
SNOW ENDS... MVFR CIGS SHOULD PERSIST INTO SATURDAY MORNING.
&&
.MARINE...(330 AM EST FRI JAN 20 2012)
WILL BE ENDING THE SMALL CRAFT ADVISORY WITH THIS FORECAST PACKAGE
AS WINDS AND WAVES SHOULD CONTINUE TO RAPIDLY SUBSIDE. NO HEADLINES
ARE EXPECTED UNTIL POSSIBLY SATURDAY NIGHT NORTH OF MUSKEGON WHEN
SOUTHEAST WINDS WILL STRENGTHEN CONSIDERABLY IN ADVANCE OF THE NEXT
APPROACHING LOW PRESSURE SYSTEM.
&&
.HYDROLOGY...(330 AM EST FRI JAN 20 2012)
SOME FLUCTUATIONS DUE TO ICE EFFECTS ARE POSSIBLE THROUGH SATURDAY.
A RAPID WARM UP BEGINNING SUNDAY ACCOMPANIED WITH RAIN SUNDAY NIGHT
COULD SEND RIVER LEVELS BACK UP EARLY NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WX ADVISORY ALONG AND SOUTH OF INTERSTATE 96 TODAY
AND TONIGHT.
LM...NONE.
&&
$$
SYNOPSIS: TJT
SHORT TERM: TJT
LONG TERM: WDM
AVIATION: WDM
MARINE: TJT
HYDROLOGY: TJT
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
956 PM CST Sat Jan 21 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Pesky strato-cu layer finally beginning to erode from the south and
west as warmer air aloft and increased mixing eat away at the
shallow saturated zone around H9. Only RUC H9 condensation pressure
deficit forecasts have accurately depicted this cloud deck today,
and show the layer finally giving way just before sunset. Still
expecting temperatures to go nowhere this evening, then actually
begin a slow climb after midnight with waa and mixing. New stratus
layer currently over NE TX/SE OK will advect north with the leading
edge of the moisture tongue, and could potentially see some fog and
drizzle in this band. However, believe forecast soundings and
numerical guidance are underestimating soil temperatures and tend to
favor more light fog/haze with dew deposition versus reduced
visibilities/drizzle in a well mixed boundary layer. Have introduced
a patchy drizzle mention later in the morning as soundings begin to
look a bit more favorable (in addition to model qpf output), but not
expecting a persistent or widespread drizzle.
Rather potent shortwave now crossing the Sierra Nevada will eject
into the central plains Sunday afternoon allowing a nice surge of
warm, moist air throughout the forecast area. Surprisingly with
better raob sampling at 12Z, there are still discrepancies among
operational models, though the general trend is for a weaker system
ejecting and lifting out further to the northwest (roughly a
KMHK-KDSM-KMSN line). Still prefer a somewhat slower and further
south timing and position per consistent ECMWF solutions given the
jet streak remaining on the south and west side of the trough base.
This should keep the majority, if not all of the cwa in the warm
sector through most of the day, and have correspondingly went
towards the warmer guidance numbers for high temps. Some locations
could spike even warmer if more than a few peaks of sun are
realized, and would not be surprised if some locations pushed above
60F.
For the most part, warm sector rainfall and convection should remain
relegated to the middle and lower Mississippi River valley Sunday
evening, with weak frontogenesis/deformation trailing through
central Kansas. Much of the local area will be dealing with the
dryslot and downslope westerly component Sunday evening, only seeing
meager wrap around moisture and precipitation potential with the
wave lifting to the northwest. Have generally cut pops and qpf
amounts given model trends, and would not expect much more than a
dusting or few tenths of rain/snow mix over northwest and north
central Missouri by Monday morning.
Virtually no cold air exists behind this system for early next week,
such that post frontal lows Monday morning will remain above average
in a well mixed boundary layer. Dry weather can be expect Monday
with the only real concern revolving around the potential of an
elevated fire danger given dry westerly downslope sfc wind, lowering
relative humidity values, and warmer than average temperatures.
21
Medium range (Tuesday through Saturday)...
For the later half of the forecast, medium range models continue to
show a fair amount of agreement on the large scale features for next
week`s forecast. A quasi-zonal flow regime is advertised to persist
across the continent as the flow across the eastern Pacific remains
rather flat. This will continue to allow fast moving shortwaves to
jet across the nation, with a few expected to periodically
cutting-off over the Desert Southwest. This would indicate that
temperatures should remain above average over the last half of the
forecast as the majority of the cold air remains sequestered to our
north, allowing afternoon highs to range from the 40s into the 50s,
with overnight lows in the mid 20s to mid 30s.
Looking closer at the forecast specifics, mid-range models of late
have begun to settle on a solution which cuts-off a low across the
Desert Southwest early in the coming work week as energy gets dumped
from the Pacific jet into a 500mb weakness noted across northern
Mexico. This is counter to other recent solutions which advertised a
more progressive track for the shortwave energy, ultimately hinting
at precipitation chances across Kansas and Missouri in the Tuesday
to Wednesday time frame. However, with the growing consensus that
the cutoff low will develop and eject through the southern Plains,
the needed moisture and lift for any precipitation looks like it
will pass to our south, thus have only kept a silent 20% POP in for
Tuesday night.
Cutter
&&
.AVIATION...
For the 06Z TAFs...Increasing southerly low level jet will continue
to advect low clouds out of the Ozarks into northwest Missouri by
sunrise. This feature will also lead to some LLWS concerns overnight.
Forecast soundings continue to suggest potential for widespread IFR
ceilings with this moisture, but confidence on this is not high given
strong warm air advection and the fact that cigs are almost all MVFR
upstream. For now, will continue to forecast MVFR cigs below 2000
feet through mid morning, which may lift above 2000 feet by
afternoon. Cold front will sweep through the region early Sunday
evening. Any precip with this feature will be very light with the
best coverage to the north of the KC terminals.
Hawblitzel
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
525 PM CST Sat Jan 21 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Pesky strato-cu layer finally beginning to erode from the south and
west as warmer air aloft and increased mixing eat away at the
shallow saturated zone around H9. Only RUC H9 condensation pressure
deficit forecasts have accurately depicted this cloud deck today,
and show the layer finally giving way just before sunset. Still
expecting temperatures to go nowhere this evening, then actually
begin a slow climb after midnight with waa and mixing. New stratus
layer currently over NE TX/SE OK will advect north with the leading
edge of the moisture tongue, and could potentially see some fog and
drizzle in this band. However, believe forecast soundings and
numerical guidance are underestimating soil temperatures and tend to
favor more light fog/haze with dew deposition versus reduced
visibilities/drizzle in a well mixed boundary layer. Have introduced
a patchy drizzle mention later in the morning as soundings begin to
look a bit more favorable (in addition to model qpf output), but not
expecting a persistent or widespread drizzle.
Rather potent shortwave now crossing the Sierra Nevada will eject
into the central plains Sunday afternoon allowing a nice surge of
warm, moist air throughout the forecast area. Surprisingly with
better raob sampling at 12Z, there are still discrepancies among
operational models, though the general trend is for a weaker system
ejecting and lifting out further to the northwest (roughly a
KMHK-KDSM-KMSN line). Still prefer a somewhat slower and further
south timing and position per consistent ECMWF solutions given the
jet streak remaining on the south and west side of the trough base.
This should keep the majority, if not all of the cwa in the warm
sector through most of the day, and have correspondingly went
towards the warmer guidance numbers for high temps. Some locations
could spike even warmer if more than a few peaks of sun are
realized, and would not be surprised if some locations pushed above
60F.
For the most part, warm sector rainfall and convection should remain
relegated to the middle and lower Mississippi River valley Sunday
evening, with weak frontogenesis/deformation trailing through
central Kansas. Much of the local area will be dealing with the
dryslot and downslope westerly component Sunday evening, only seeing
meager wrap around moisture and precipitation potential with the
wave lifting to the northwest. Have generally cut pops and qpf
amounts given model trends, and would not expect much more than a
dusting or few tenths of rain/snow mix over northwest and north
central Missouri by Monday morning.
Virtually no cold air exists behind this system for early next week,
such that post frontal lows Monday morning will remain above average
in a well mixed boundary layer. Dry weather can be expect Monday
with the only real concern revolving around the potential of an
elevated fire danger given dry westerly downslope sfc wind, lowering
relative humidity values, and warmer than average temperatures.
21
Medium range (Tuesday through Saturday)...
For the later half of the forecast, medium range models continue to
show a fair amount of agreement on the large scale features for next
week`s forecast. A quasi-zonal flow regime is advertised to persist
across the continent as the flow across the eastern Pacific remains
rather flat. This will continue to allow fast moving shortwaves to
jet across the nation, with a few expected to periodically
cutting-off over the Desert Southwest. This would indicate that
temperatures should remain above average over the last half of the
forecast as the majority of the cold air remains sequestered to our
north, allowing afternoon highs to range from the 40s into the 50s,
with overnight lows in the mid 20s to mid 30s.
Looking closer at the forecast specifics, mid-range models of late
have begun to settle on a solution which cuts-off a low across the
Desert Southwest early in the coming work week as energy gets dumped
from the Pacific jet into a 500mb weakness noted across northern
Mexico. This is counter to other recent solutions which advertised a
more progressive track for the shortwave energy, ultimately hinting
at precipitation chances across Kansas and Missouri in the Tuesday
to Wednesday time frame. However, with the growing consensus that
the cutoff low will develop and eject through the southern Plains,
the needed moisture and lift for any precipitation looks like it
will pass to our south, thus have only kept a silent 20% POP in for
Tuesday night.
Cutter
&&
.AVIATION...
For the 00Z TAFs...Back edge of MVFR deck is very close to a STJ-
MCI-MKC line and expect this back edge to move through the terminals
within the hour. Increasing low level jet will lead to some LLWS
concerns overnight, and will also act to advect low clouds from
southeast Oklahoma into northwest Missouri by sunrise. Current
thinking is that strong warm air advection may make it difficult to
achieve widespread IFR ceilings as forecast soundings are suggesting.
Similar pattern last week resulted in a scattered to broken MVFR
deck, and believe this may be more realistic. For now will keep
ceilings MVFR below 2000 feet through mid morning, though this may
end up being pessimistic. Cold front will arrive late in the period
with improving sky conditions and veering low level winds.
Hawblitzel
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
343 PM CST FRI JAN 20 2012
.DISCUSSION...
/336 PM CST FRI JAN 20 2012/
A WINTER WEATHER ADVISORY FOR FREEZING DRIZZLE/RAIN WAS ISSUED
EARLIER THIS AFTN BASED ON MODEL DEPICTIONS OF WEAK LIFT OCCURRING
WITHIN AN INCREASINGLY SATURATED ATMOSPHERE /SFC TO ABOUT 10KFT/.
REGIONAL OBSERVATIONS FROM ASOS/AWOS...INCREASING SATURATION
INFERRED FROM VAD WIND PROFILES...AND SATELLITE IMAGERY ALL SUPPORT
THE IDEA THAT THE LOWER ATMOSPHERE IS BECOMING SATURATED WITH
TIME. WITH A MODIFIED ARCTIC AIR MASS IN PLACE...SFC TEMPERATURES
HAVE BEEN BELOW FREEZING FOR LONG ENOUGH THAT ANY LIQUID PCPN
SHOULD FREEZE ON CONTACT WITH ELEVATED AND UNTREATED SURFACES. IN
OTHER WORDS...A LIGHT GLAZE IS EXPECTED TO FORM ON UNTREATED AND
ELEVATED SURFACES AND AFFECT THE EVENING RUSH HOUR COMMUTE. PCPN
SHOULD END BY MIDNIGHT AS FORCING MOVES EAST OF THE AREA.
SFC HIGH BUILDS ACROSS THE REGION LATER TONIGHT AND PERSISTS THROUGH
TOMORROW NIGHT AS THE UPPER LEVEL FLOW BECOMES INCREASINGLY
DIFFLUENT AHEAD OF THE NEXT SHORTWAVE. LATEST MODEL RUNS ARE NEARLY
UNANIMOUS IN DEPICTING A STRONG TROF BECOMING NEGATIVELY TILTED AS
IT LIFTS THROUGH THE REGION ON SUNDAY AFTN AND EVENING ALTHOUGH
THERE IS SOME MODEL DISAGREEMENT ABOUT WHERE THE SRN SFC LOW WILL
DVLP /GEM DEPICTS SFC CYCLOGENESIS IN NEBRASKA WHILE THE GFS PUTS IT
IN OKLAHOMA/. REGARDLESS...SFC LOW WILL LIFT A WARM FRONT THROUGH
THE CWA ON SUNDAY CAUSING TEMPERATURES TO WARM NEARLY 15 DEGREES
ABOVE AVERAGE FOR THIS TIME OF YEAR. DIFFLUENT FLOW ALOFT AND A LLJ
RIDING OVER THE LIFTING WMFNT MAY PRODUCE SOME SPOTTY TO SCT RAIN
SHOWERS ON SUNDAY MORNING HOWEVER THE MAIN PCPN EVENT WILL PROBABLY
OCCUR ON SUNDAY AFTERNOON AND EVENING. FACTORS SUPPORTING
THUNDERSTORMS OVER PART OF THE AREA ON SUNDAY NIGHT INCLUDE
INCREASING LAPSE RATES...PW VALUES AROUND 0.7 IN...DECREASED
STABILITY FROM THE COLD AIR ALOFT WITHIN A NEGATIVELY TILTED
TROF...AND FAVORABLE PLACEMENT BENEATH THE LEFT EXIT REGIONS OF
CYCLONICALLY CURVED JET STREAKS AT H5 AND H3. PCPN SHOULD END AFTER
THE COLD FRONT MOVES THROUGH WITH PERHAPS SOME CLOUDS PERSISTING DUE
TO CYCLONIC FLOW ALOFT.
AFTER A BRIEF PD OF RIDGING ON MON NIGHT AND TUE...MODELS SHOW
ANOTHER SYSTEM CUTTING OFF OVER NRN MEXICO OR SWRN TEXAS ON TUE
NIGHT. LOW CONFIDENCE ATTM IN THE FORECAST FOR THE MIDDLE AND END OF
NEXT WEEK GIVEN MODEL VARIABILITY WITH THIS SYSTEM OVER THE PAST
COUPLE OF DAYS.
KANOFSKY/BRITT
&&
.AVIATION...
/1101 AM CST FRI JAN 20 2012/
LOCAL WRF AND RUC MODEL RUNS THIS MORNING ARE TRENDING THE
FORECAST TOWARD A MORE ICY LATE AFTERNOON/EVENING SOLUTION FOR
LOCATIONS ALONG AND SOUTH OF I-44 CORRIDOR IN MISSOURI AND I-70 IN
ILLINOIS. ATMOSPHERE WILL CONTINUE TO SATURATE THIS AFTERNOON WITH
PERSISTENT LOW LEVEL MOISTURE CONVERGENCE. RIGHT ENTRANCE REGION
OF THE UPPER LEVEL JET WILL PROVIDE ADDITIONAL LIFT LATE THIS
AFTERNOON TO PRODUCE A BAND OF FREEZING DRIZZLE OR LIGHT FREEZING
RAIN FROM THE OZARKS NORTHEAST TOWARD THE ST. LOUIS METRO AREA.
THIS BAND WILL EXPAND WITH TIME THIS EVENING TO THE EAST ACROSS
SOUTHERN ILLINOIS BEFORE EXITING THE CWA AROUND 06Z. ICE
ACCUMULATION SHOULD REMAIN BELOW ONE TENTH OF AN INCH.
OTHERWISE...EAST WIND WILL BECOME NORTH THROUGH THE PERIOD. SHOULD
SEE IMPROVING CONDITIONS AFTER MIDNIGHT WITH SKIES SCT OUT.
SPECIFICS FOR KSTL...
FREEZING DRIZZLE OR LIGHT FREEZING RAIN WILL DEVELOP THIS
AFTERNOON AND IMPACT THE TERMINAL THIS EVENING BETWEEN 23Z AND
02Z. CEILING WILL FALL TO LOW END MVFR WITH LOCAL REDUCTIONS IN
VISIBILITY THIS EVENING. EAST WIND WILL BECOME NORTH THROUGH THE
PERIOD. ICE ACCUMULATION SHOULD REMAIN LESS THAN A TENTH OF AN
INCH...BUT AMBIENT TEMPERATURES IN THE 20S WILL CAUSE UNTREATED
RUNWAYS TO BECOME VERY SLICK.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CRAWFORD
MO-FRANKLIN MO-IRON MO-JEFFERSON MO-MADISON MO-REYNOLDS MO-
ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS
MO-STE. GENEVIEVE MO-WASHINGTON MO.
IL...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BOND IL-
CLINTON IL-FAYETTE IL-JERSEY IL-MACOUPIN IL-MADISON IL-
MARION IL-MONROE IL-MONTGOMERY IL-RANDOLPH IL-ST. CLAIR IL-
WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1137 AM CST FRI JAN 20 2012
.UPDATE...
/1137 AM CST FRI JAN 20 2012/
...WINTER WEATHER ADVISORY ISSUED FOR LIGHT ACCUMULATION OF ICE...
HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE SOUTHEASTERN HALF OF
THE CWA FOR LATE THIS AFTERNOON AND THIS EVENING. RUC...NAM AND
LOCAL WRF SOUNDINGS ARE ALL INDICATING THE LOW CLOUDS OVER THE
AREA SHOULD THICKEN THROUGH THE AFTERNOON...WITH THE RUC SOUNDING
SHOWING SATURATION BETWEEN THE SURFACE TO 10K FT AT FAM BY 3 PM
AND STL BY 5 PM. THIS STRONGLY SUGGESTS THE POTENTIAL FOR AT LEAST
DRIZZLE FORMATION. MODELS ARE ALSO SHOWING THAT THERE WILL BE
INCREASED ASCENT OVER THE AREA DURING THIS SAME TIME FRAME CAUSED
BY SHORTWAVE MOVING QUICKLY EASTWARD FROM THE CENTRAL PLAINS.
MODEL QPF FIELDS ALSO ARE SHOWING AROUND A TENTH OF AN INCH OF QPF
OVER THE SOUTHERN CWA. EASTERLY WINDS AND LOW CLOUDS WILL LIMIT
TEMPERATURE RISES...SO EXPECT PRECIPITATION TO FALL AS MAINLY
FREEZING DRIZZLE OR LIGHT FREEZING RAIN. TEMPERATURES OVER THE FAR
SOUTHERN PART OF THE CWA MAY ALLOW FOR A BRIEF CHANGEOVER TO
LIQUID. OTHERWISE...HAVE LEFT ONLY CHANCES FOR SNOW OVER THE THE
NORTHERN CWA AS MAIN SNOW BAND IS STAYING WELL NORTH OF THE AREA.
BRITT
&&
.DISCUSSION...
/340 AM CST FRI JAN 20 2012/
DEALING WITH A NORTHERN STREAM AND SOUTHERN STREAM SYSTEM...THAT
WILL TRY TO CONVERGE OVER THE FORECAST AREA LATER TODAY.
STARTING OFF RATHER COLD THIS MORNING WITH TEMPS IN THE SINGLE
DIGITS FAR NORTH TO THE MID 20S FAR SOUTH. IN THE MEANTIME...SC DECK
ADVECTING NORTHWARD INTO SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS...AND COULD REACH METRO AREA BY MID MORNING. THEN IN THE
NORTH...MID CLOUD DECK WITH NORTHERN STREAM SYSTEM HAS BEGUN TO MOVE
IN. THIS COULD STIFLE TEMPS TODAY. SO BACKED OFF ON HIGH TEMPS...
RANGING FROM THE MID 20S FAR NORTH TO THE MID 30S SOUTH...THOUGH
COULD SEE UPPER 30S OVER CENTRAL MO...SINCE THEY WILL SEE A BIT MORE
SUN TODAY.
AS FOR PCPN CHANCES...SOME LIGHT SNOW WILL BE POSSIBLE OVER
NORTHEAST MO...WEST CENTRAL ILLINOIS THIS MORNING AS FIRST IN A
SERIES OF SHORTWAVES MOVES THROUGH. SOME CONCERN ABOUT FREEZING
DRIZZLE OVER SOUTHERN MISSOURI THIS MORNING AS SC DECK SLIDES IN.
CONDENSATION PRESSURE DEFICITS ARE FAIRLY HIGH...BUT DO BEGIN TO
LOWER TOWARDS MIDDAY...WITH SOME WEAK WAA WHICH COULD HELP TO
PRODUCE SOME FREEZING DRIZZLE/DRIZZLE. FOR NOW KEPT THAT AREA DRY
TIL THIS AFTERNOON. AS FOR THIS AFTERNOON...START TO SEE SYSTEMS
CONVERGE OVER REGION...WITH AREAS ALONG I-70 POSSIBLY IN THE DRY
SLOT BETWEEN THE TWO SYSTEMS. KEPT MENTION OF PATCHY FREEZING
DRIZZLE/DRIZZLE ALONG I-70 CORRIDOR...MAINLY FOR AREAS EAST OF A
MEXICO TO MONTGOMERY CITY TO OWENSVILLE LINE. THIS INCLUDES THE ST.
LOUIS METRO AREA. OTHERWISE...REST OF AREA TO SEE ONLY LIGHT QPF AS
WELL...BUT ENOUGH TO KEEP LOW CHANCE POPS GOING...AND DID RAISE THEM
A BIT OVER SOUTHEAST MO AND SOUTHERN IL. COULD SEE UP TO A TENTH OF
AN INCH OF LIGHT SNOW OVER NORTHEAST MO/WEST CENTRAL IL THIS
AFTERNOON. AS FOR ANY ICE ACCUMULATION...CAN JUST EXPECT A VERY
LIGHT GLAZE AT THIS TIME.
BYRD
THINGS WILL REACH A CRESCENDO EARLY THIS EVENING AS ALL OF THE
ELEMENTS...AS BEST THEY CAN...TRY TO COME TOGETHER OVER THE FA. NAM
IS A BIT SLOWER AND AN OUTLIER WITH THE FORWARD SPEED WHICH IS HARD
TO UNDERSTAND GIVEN SUCH A ZONAL MID LEVEL FLOW...AND PREFER A RAPID
TRANSIT THRU THE FA THIS EVENING OF THE LIFT AND MOISTURE. DEEPER
MOISTURE...THAT WILL BE ABLE TO RESULT IN ICE PRODUCTION...WILL
REMAIN LARGELY TO OUR N...LEAVING BEHIND A MOSTLY DRIZZLE SETUP OVER
THE FA THAT WILL BE DRIVEN PRIMARILY BY A WEAK INVERTED TROF
TRAVELLING THRU THE CNTRL/SRN FA...BEFORE A MORE CONGEALED SFC LO
CAN FORM TO OUR E. SFC TEMPS OVER MUCH OF THE AREA ARE EXPECTED TO
BE AT OR BELOW 32F FROM THE START OF TONIGHT...AND THIS WILL
ULTIMATELY RESULT IN FREEZING DRIZZLE. THANKS TO THE RAPID SPEED OF
ANY SOURCES OF LIFT...AMOUNTS WILL STRUGGLE TO MEASURE AND HAVE GONE
WITH POPS AT OR BELOW 50PCT FOR THE REGION. BY 9PM...PCPN IS
EXPECTED TO LEAVE OR COME TO AN END OVER THE STL METRO AREA AND
AREAS TO THE NW...WHILE THE PCPN SHOULD END BY MIDNIGHT FOR AREAS TO
THE SE. NAM SUGGESTS THAT PCPN MAY BE MORE SUBSTANTIAL AND HANG ON
LONGER DUE TO THE SLOWER EWD MOVEMENT OF THE DEVELOPING SFC LO...
WHICH WILL LINGER LO LEVEL CONVERGENCE FOR LONGER WHICH WILL DRIVE
THE FZDZ. THIS SOLUTION OVERALL REJECTED FOR ITS SLOWER MOVEMENT...
BUT CONSIDERING HOW THE SYSTEM WAS STILL JUST COMING ONSHORE AT 00Z
THIS EVENING...IF THIS PLAYS OUT...IT WILL RESULT IN MORE
SUBSTANTIAL ICE ACCRETION.
PREFERRED WARMER MOS TEMPS ON SATURDAY AS DECENT AMOUNT OF SUNSHINE
EXPECTED. STRENGTHENING S FLOW ON SUNDAY WILL ALLOW TEMPS TO SURGE
WELL ABOVE AVERAGE THANKS TO RISING TEMPS THE NIGHT BEFORE.
QUESTIONABLE AMOUNTS OF STRATUS WITH INCREASED MOISTURE MAY RESULT
IN LOWER MET MOS NUMBERS PANNING OUT. CDFNT WILL THEN COME THRU
LATE IN THE DAY...AND SIMILAR TO WHAT WE ARE GOING TO SEE TODAY...
EVERYTHING COMES TOGETHER BRIEFLY FOR A SHORT-LIVED PCPN EVENT LATE
IN THE DAY...BUT WITH MUCH WARMER TEMPS...THIS WILL BE RAIN. ECMWF
EVEN GOES SO FAR TO SUGGEST THUNDER POTENTIAL.
AFTER ANOTHER QUIET PERIOD EARLY NEXT WEEK...ECMWF AND GFS DIVERGE
SIGNIFICANTLY ON WHAT TO DO WITH THE NEXT BIG WRN CONUS SYSTEM.
ECMWF CUTS IT OFF INTO NRN OLD MEXICO...WHILE GFS KEEPS IT AS A
STRONG PROGRESSIVE WAVE THAT WILL PUSH THRU THE FA DURING
WEDNESDAY-THURSDAY. WHILE ECMWF EVEN PUSHES THRU A GREATLY REDUCED
NRN STREAM SYSTEM AT THIS TIME...NEEDLESS TO SAY...LO CONFIDENCE
CONTINUES FOR THE MEDIUM RANGE. MAINTAINED LO CHC POPS FROM
PREVIOUS FCST. TEMPS SHOULD BE NOT TOO FAR AWAY FROM AVERAGE.
TES
&&
.AVIATION...
/1101 AM CST FRI JAN 20 2012/
LOCAL WRF AND RUC MODEL RUNS THIS MORNING ARE TRENDING THE
FORECAST TOWARD A MORE ICY LATE AFTERNOON/EVENING SOLUTION FOR
LOCATIONS ALONG AND SOUTH OF I-44 CORRIDOR IN MISSOURI AND I-70 IN
ILLINOIS. ATMOSPHERE WILL CONTINUE TO SATURATE THIS AFTERNOON WITH
PERSISTENT LOW LEVEL MOISTURE CONVERGENCE. RIGHT ENTRANCE REGION
OF THE UPPER LEVEL JET WILL PROVIDE ADDITIONAL LIFT LATE THIS
AFTERNOON TO PRODUCE A BAND OF FREEZING DRIZZLE OR LIGHT FREEZING
RAIN FROM THE OZARKS NORTHEAST TOWARD THE ST. LOUIS METRO AREA.
THIS BAND WILL EXPAND WITH TIME THIS EVENING TO THE EAST ACROSS
SOUTHERN ILLINOIS BEFORE EXITING THE CWA AROUND 06Z. ICE
ACCUMULATION SHOULD REMAIN BELOW ONE TENTH OF AN INCH.
OTHERWISE...EAST WIND WILL BECOME NORTH THROUGH THE PERIOD. SHOULD
SEE IMPROVING CONDIITONS AFTER MIDNIGHT WITH SKIES SCT OUT.
SPECIFICS FOR KSTL...
FREEZING DRIZZLE OR LIGHT FREEZING RAIN WILL DEVELOP THIS
AFTERNOON AND IMPACT THE TERMINAL THIS EVENING BETWEEN 23Z AND
02Z. CEILING WILL FALL TO LOW END MVFR WITH LOCAL REDUCTIONS IN
VISIBILITY THIS EVENING. EAST WIND WILL BECOME NORTH THROUGH THE
PERIOD. ICE ACCUMULATION SHOULD REMAIN LESS THAN A TENTH OF AN
INCH...BUT AMBIENT TEMPERATURES IN THE 20S WILL CAUSE UNTREATED
RUNWAYS TO BECOME VERY SLICK.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST
TONIGHT FOR CRAWFORD MO-FRANKLIN MO-IRON MO-JEFFERSON MO-
MADISON MO-REYNOLDS MO-ST. CHARLES MO-ST. FRANCOIS MO-ST.
LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WASHINGTON MO.
IL...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST
TONIGHT FOR BOND IL-CLINTON IL-FAYETTE IL-JERSEY IL-
MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL-
RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1118 AM CST FRI JAN 20 2012
.DISCUSSION...
/340 AM CST FRI JAN 20 2012/
DEALING WITH A NORTHERN STREAM AND SOUTHERN STREAM SYSTEM...THAT
WILL TRY TO CONVERGE OVER THE FORECAST AREA LATER TODAY.
STARTING OFF RATHER COLD THIS MORNING WITH TEMPS IN THE SINGLE
DIGITS FAR NORTH TO THE MID 20S FAR SOUTH. IN THE MEANTIME...SC DECK
ADVECTING NORTHWARD INTO SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS...AND COULD REACH METRO AREA BY MID MORNING. THEN IN THE
NORTH...MID CLOUD DECK WITH NORTHERN STREAM SYSTEM HAS BEGUN TO MOVE
IN. THIS COULD STIFLE TEMPS TODAY. SO BACKED OFF ON HIGH TEMPS...
RANGING FROM THE MID 20S FAR NORTH TO THE MID 30S SOUTH...THOUGH
COULD SEE UPPER 30S OVER CENTRAL MO...SINCE THEY WILL SEE A BIT MORE
SUN TODAY.
AS FOR PCPN CHANCES...SOME LIGHT SNOW WILL BE POSSIBLE OVER
NORTHEAST MO...WEST CENTRAL ILLINOIS THIS MORNING AS FIRST IN A
SERIES OF SHORTWAVES MOVES THROUGH. SOME CONCERN ABOUT FREEZING
DRIZZLE OVER SOUTHERN MISSOURI THIS MORNING AS SC DECK SLIDES IN.
CONDENSATION PRESSURE DEFICITS ARE FAIRLY HIGH...BUT DO BEGIN TO
LOWER TOWARDS MIDDAY...WITH SOME WEAK WAA WHICH COULD HELP TO
PRODUCE SOME FREEZING DRIZZLE/DRIZZLE. FOR NOW KEPT THAT AREA DRY
TIL THIS AFTERNOON. AS FOR THIS AFTERNOON...START TO SEE SYSTEMS
CONVERGE OVER REGION...WITH AREAS ALONG I-70 POSSIBLY IN THE DRY
SLOT BETWEEN THE TWO SYSTEMS. KEPT MENTION OF PATCHY FREEZING
DRIZZLE/DRIZZLE ALONG I-70 CORRIDOR...MAINLY FOR AREAS EAST OF A
MEXICO TO MONTGOMERY CITY TO OWENSVILLE LINE. THIS INCLUDES THE ST.
LOUIS METRO AREA. OTHERWISE...REST OF AREA TO SEE ONLY LIGHT QPF AS
WELL...BUT ENOUGH TO KEEP LOW CHANCE POPS GOING...AND DID RAISE THEM
A BIT OVER SOUTHEAST MO AND SOUTHERN IL. COULD SEE UP TO A TENTH OF
AN INCH OF LIGHT SNOW OVER NORTHEAST MO/WEST CENTRAL IL THIS
AFTERNOON. AS FOR ANY ICE ACCUMULATION...CAN JUST EXPECT A VERY
LIGHT GLAZE AT THIS TIME.
BYRD
THINGS WILL REACH A CRESCENDO EARLY THIS EVENING AS ALL OF THE
ELEMENTS...AS BEST THEY CAN...TRY TO COME TOGETHER OVER THE FA. NAM
IS A BIT SLOWER AND AN OUTLIER WITH THE FORWARD SPEED WHICH IS HARD
TO UNDERSTAND GIVEN SUCH A ZONAL MID LEVEL FLOW...AND PREFER A RAPID
TRANSIT THRU THE FA THIS EVENING OF THE LIFT AND MOISTURE. DEEPER
MOISTURE...THAT WILL BE ABLE TO RESULT IN ICE PRODUCTION...WILL
REMAIN LARGELY TO OUR N...LEAVING BEHIND A MOSTLY DRIZZLE SETUP OVER
THE FA THAT WILL BE DRIVEN PRIMARILY BY A WEAK INVERTED TROF
TRAVELLING THRU THE CNTRL/SRN FA...BEFORE A MORE CONGEALED SFC LO
CAN FORM TO OUR E. SFC TEMPS OVER MUCH OF THE AREA ARE EXPECTED TO
BE AT OR BELOW 32F FROM THE START OF TONIGHT...AND THIS WILL
ULTIMATELY RESULT IN FREEZING DRIZZLE. THANKS TO THE RAPID SPEED OF
ANY SOURCES OF LIFT...AMOUNTS WILL STRUGGLE TO MEASURE AND HAVE GONE
WITH POPS AT OR BELOW 50PCT FOR THE REGION. BY 9PM...PCPN IS
EXPECTED TO LEAVE OR COME TO AN END OVER THE STL METRO AREA AND
AREAS TO THE NW...WHILE THE PCPN SHOULD END BY MIDNIGHT FOR AREAS TO
THE SE. NAM SUGGESTS THAT PCPN MAY BE MORE SUBSTANTIAL AND HANG ON
LONGER DUE TO THE SLOWER EWD MOVEMENT OF THE DEVELOPING SFC LO...
WHICH WILL LINGER LO LEVEL CONVERGENCE FOR LONGER WHICH WILL DRIVE
THE FZDZ. THIS SOLUTION OVERALL REJECTED FOR ITS SLOWER MOVEMENT...
BUT CONSIDERING HOW THE SYSTEM WAS STILL JUST COMING ONSHORE AT 00Z
THIS EVENING...IF THIS PLAYS OUT...IT WILL RESULT IN MORE
SUBSTANTIAL ICE ACCRETION.
PREFERRED WARMER MOS TEMPS ON SATURDAY AS DECENT AMOUNT OF SUNSHINE
EXPECTED. STRENGTHENING S FLOW ON SUNDAY WILL ALLOW TEMPS TO SURGE
WELL ABOVE AVERAGE THANKS TO RISING TEMPS THE NIGHT BEFORE.
QUESTIONABLE AMOUNTS OF STRATUS WITH INCREASED MOISTURE MAY RESULT
IN LOWER MET MOS NUMBERS PANNING OUT. CDFNT WILL THEN COME THRU
LATE IN THE DAY...AND SIMILAR TO WHAT WE ARE GOING TO SEE TODAY...
EVERYTHING COMES TOGETHER BRIEFLY FOR A SHORT-LIVED PCPN EVENT LATE
IN THE DAY...BUT WITH MUCH WARMER TEMPS...THIS WILL BE RAIN. ECMWF
EVEN GOES SO FAR TO SUGGEST THUNDER POTENTIAL.
AFTER ANOTHER QUIET PERIOD EARLY NEXT WEEK...ECMWF AND GFS DIVERGE
SIGNIFICANTLY ON WHAT TO DO WITH THE NEXT BIG WRN CONUS SYSTEM.
ECMWF CUTS IT OFF INTO NRN OLD MEXICO...WHILE GFS KEEPS IT AS A
STRONG PROGRESSIVE WAVE THAT WILL PUSH THRU THE FA DURING
WEDNESDAY-THURSDAY. WHILE ECMWF EVEN PUSHES THRU A GREATLY REDUCED
NRN STREAM SYSTEM AT THIS TIME...NEEDLESS TO SAY...LO CONFIDENCE
CONTINUES FOR THE MEDIUM RANGE. MAINTAINED LO CHC POPS FROM
PREVIOUS FCST. TEMPS SHOULD BE NOT TOO FAR AWAY FROM AVERAGE.
TES
&&
.AVIATION...
/1101 AM CST FRI JAN 20 2012/
LOCAL WRF AND RUC MODEL RUNS THIS MORNING ARE TRENDING THE
FORECAST TOWARD A MORE ICY LATE AFTERNOON/EVENING SOLUTION FOR
LOCATIONS ALONG AND SOUTH OF I-44 CORRIDOR IN MISSOURI AND I-70 IN
ILLINOIS. ATMOSPHERE WILL CONTINUE TO SATURATE THIS AFTERNOON WITH
PERSISTENT LOW LEVEL MOISTURE CONVERGENCE. RIGHT ENTRANCE REGION
OF THE UPPER LEVEL JET WILL PROVIDE ADDITIONAL LIFT LATE THIS
AFTERNOON TO PRODUCE A BAND OF FREEZING DRIZZLE OR LIGHT FREEZING
RAIN FROM THE OZARKS NORTHEAST TOWARD THE ST. LOUIS METRO AREA.
THIS BAND WILL EXPAND WITH TIME THIS EVENING TO THE EAST ACROSS
SOUTHERN ILLINOIS BEFORE EXITING THE CWA AROUND 06Z. ICE
ACCUMULATION SHOULD REMAIN BELOW ONE TENTH OF AN INCH.
OTHERWISE...EAST WIND WILL BECOME NORTH THROUGH THE PERIOD. SHOULD
SEE IMPROVING CONDIITONS AFTER MIDNIGHT WITH SKIES SCT OUT.
SPECIFICS FOR KSTL...
FREEZING DRIZZLE OR LIGHT FREEZING RAIN WILL DEVELOP THIS
AFTERNOON AND IMPACT THE TERMINAL THIS EVENING BETWEEN 23Z AND
02Z. CEILING WILL FALL TO LOW END MVFR WITH LOCAL REDUCTIONS IN
VISIBILITY THIS EVENING. EAST WIND WILL BECOME NORTH THROUGH THE
PERIOD. ICE ACCUMULATION SHOULD REMAIN LESS THAN A TENTH OF AN
INCH...BUT AMBIENT TEMPERATURES IN THE 20S WILL CAUSE UNTREATED
RUNWAYS TO BECOME VERY SLICK.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST
TONIGHT FOR CRAWFORD MO-FRANKLIN MO-IRON MO-JEFFERSON MO-
MADISON MO-REYNOLDS MO-ST. CHARLES MO-ST. FRANCOIS MO-ST.
LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WASHINGTON MO.
IL...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST
TONIGHT FOR BOND IL-CLINTON IL-FAYETTE IL-JERSEY IL-
MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL-
RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
358 AM CST Fri Jan 20 2012
.DISCUSSION...
Forecast challenges continue aplenty thanks to the many shortwaves
within the prevailing zonal flow that is currently dominating the
nation. Water vapor imagery from early this morning shows one of the
shortwaves of note, shifting through the central Rockies, accompanied
by a fair amount of mid and high level Pacific moisture, as noted by
the cloud cover spilling over the continental divide. Another
shortwave that will be effecting our weather over the Sunday/Monday
periods is noted shifting through the eastern Pacific under a low
anchored in the Gulf of Alaska. Closer to home, a cold surface high
is seen shifting from the Northern Plains into the Great Lakes.
For today, verity of models all advertise that the shortwave
shifting through the Rocky Mountains will continue due east across
the Central and Northern Plains States today, undergoing only minor
amplification as it crosses the Nation. Isentropic lift on surfaces
from 280K and up has already begun to result in bands of snow across
western Iowa this morning. This activity is expected to shift off to
the east through the day along with the parent shortwave. A dry
easterly surface wind should limit how far south the snow will
settle as top down saturation through the dry boundary layer will be
difficult, but not impossible. Have kept a modest chance of snow and
flurries for today along the Iowa border as a result. Otherwise, low
clouds could be an issue farther south as a weak inverted trough
tries to focus some moisture along the backside of the exiting
surface high. Some fleeting sprinkles or - if cold enough - flurries
could fall from the clouds as far south as central Missouri today as
a result, though have opted not to include in the forecast at this
time owing to the low potential.
For the weekend, it looks like a bit of a roller coaster ride for
our temperatures, among other things. Saturday, temperatures will
stay around to below normal as another cold surface high oozes
through the region behind the shortwave bringing snow to Iowa
today. However, our attention then turns towards the East Pacific
shortwave, and Sunday. At this time, both mid and short range models
advertise the Pacific shortwave amplifying as it cross the United
States, allowing a quick return flow to spread into the Southern and
Central Plains. This will result in our jumping from below normal
temperatures Saturday, to above normal temperatures Sunday. The
accompanying moisture return will also result in the potential for
more precipitation during the afternoon and overnight hours of
Sunday.
Looking at next work week, mid range models continue to hint at
another amplifying shortwave moving across the nation. Confidence in
any particular solution is a bit low, but the consensus is
sufficient to warrant keeping some POPs in for Tuesday into
Wednesday, with the emphasis on Tuesday night.
Cutter
&&
.AVIATION...
For the 06z TAF...Will continue VFR conditions overnight but changes
now considered after 12z Friday. Short range models, NAM/GFS Bufr
and RUC soundings now more adamant that MVFR cigs will develop
around sunrise Friday over northwest MO as an inverted surface trof
extends through west central MO. With an east to ese boundary layer
wind this sets up the potential for warm air advection which would
allow the stratus deck to form. Confidence has improved enough to
warrant adding MVFR cigs until the inverted surface trough is pushed
east in the afternoon in response to a fast moving shortwave
streaking through KS. Should see drier air/subsidence flow back into
the terminals after sunset which should scatter out the stratus deck
leaving VFR conditions for tomorrow night.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1132 PM CST THU JAN 19 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
/305 PM CST THU JAN 19 2012/
High momentum quasi-zonal flow will persist across the conus through
the weekend, becoming more amplified yet still in a progressive
state by Sunday. Shortwave trough and attendant rich Pacific
moisture source affecting the Pacific NW today will shear eastward
across the Rockies inducing weak lee cyclogenesis Friday with a
modified boundary layer return flow pulling into the mid Mississippi
River valley. The vast majority of elevated waa and top down
saturation via Pacific moisture should be relegated to the I-80
corridor and points north, though flurries/light snow could
potentially affect far northern/northeast Missouri as weak
uvv/isentropic ascent in the cold cloud bearing layer supportive for
ice crystal growth clip this region. Overall, would expect little if
any accumulation.
Will also need to watch trajectories of return flow from the south
and the potential for extensive low clouds and drizzle through a
largely part of the cwa. Am quite skeptical of model moisture
profile initializations this morning; and consequently this leads to
higher uncertainty regarding any saturation in the boundary layer
Friday morning. NAM-WRF is most aggressive with low clouds north of
a developing warm front, with other models only partially becoming
saturated. Feel central Missouri stands the best chance for low
clouds and possible some drizzle, yet sounding profiles are not
quite indicative of drizzle. Further west, more veered wind profiles
just below the H8 inversion layer suggest drier air precluding
saturation. Have hedged towards the drier solutions feeling modeled
soil/atmosphere interface is too cold and saturated versus reality.
Nevertheless, with or without low clouds, more extensive mid/high
clouds streaming over the Rockies should limit overall insolation,
and have kept forecast temps near a model blend around climatology,
or about a category lower than previously advertised.
Dry and cool high pressure will maintain its influence over the
region on Saturday insuring temperatures once again near or slightly
below the climatological average. Renewed stronger lee cyclogenesis
late Saturday afternoon will allow sfc winds to back around to a sly
direction, strengthening through the evening and overnight hours.
Thus, expect temperatures to actually begin to rise not long after
sunset Saturday into Sunday morning.
21
Sunday - Wednesday:
Models continue to struggle with the timing and intensity of a
system for the early part of next week. However there has been
increased consistency for a few runs in bringing the system into the
area Sunday into Monday. Both the ECMWF and the GFS show a rather
strong wave moving through the Central Plains Sunday and this has
some support from the GFS ensemble mean and the ECMWF ensemble mean.
The GEM looks to be a bit too fast compared to the other models but
also moves a wave through the area Sunday. The placement of the wave
from the current suite of models brings the main energy associated
with the system a bit further north but again there is agreement
amongst the deterministic models and their ensemble partners. With
the placement possibly a bit further north and with the wave
currently looking rather robust, have increased temperatures for
Sunday. There is the potential to see temperatures in the 60s for at
least southern zones but if trends continue we could see more
widespread 60+ degree readings. In fact, if this were springtime and
not mid January the warm sector dynamics would be fairly conducive
for severe weather. Fortunately it is still January and it should
just lead to a warm and windy day with perhaps a few showers during
the afternoon before the system lifts away and temperatures begin to
drop on the backside of the low. Models produce a well pronounced
deformation area which for now would affect mainly northern Kansas
through Nebraska and Iowa. Some wrap around precipitation is likely
though, given current forecast track and as cold air advects into
the region, in the wake of the departing low, a transition to some
light snow is expected. This should mainly impact northern Missouri.
Models show another wave entering the region Wednesday into Thursday
but the GFS seems too intense with its QPF given that the wave tries
to split into a northern stream wave and southwestern closed low.
Given this have eased up on POPs for the middle of the week which
were fairly heavily influenced by the going forecast and the and GFS.
CDB
&&
.AVIATION...
For the 06z TAF...Will continue VFR conditions overnight but changes
now considered after 12z Friday. Short range models, NAM/GFS Bufr
and RUC soundings now more adamant that MVFR cigs will develop
around sunrise Friday over northwest MO as an inverted surface trof
extends through west central MO. With an east to ese boundary layer
wind this sets up the potential for warm air advection which would
allow the stratus deck to form. Confidence has improved enough to
warrant adding MVFR cigs until the inverted surface trough is pushed
east in the afternoon in response to a fast moving shortwave
streaking through KS. Should see drier air/subsidence flow back into
the terminals after sunset which should scatter out the stratus deck
leaving VFR conditions for tomorrow night.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
945 PM CST SAT JAN 21 2012
.UPDATE...
UPDATED TO REFLECT CURRENT CONDITIONS. WINDS HAVE FALLEN OFF SOME
CLOUDS HAVE INCREASED AND TEMPERATURES ARE AT OR NEAR OVERNIGHT
LOW. LOWERED TEMPERATURES OVER NORTH CENTRAL ZONES WHERE
TEMPERATURES HAVE FALLEN THE MOST.
&&
.PREV DISCUSSION... /ISSUED 605 PM CST SAT JAN 21 2012/
AVIATION...
A WINTER STORM IS APPROACHING WESTERN AND NORTH CENTRAL NEBRASKA
FROM THE WEST TONIGHT. MID AND HIGH CLOUDS PRESENT WITH VISUAL
FLIGHT RULES. SNOW WILL BEGIN OVER THE NORTHERN NEBRASKA PANHANDLE
AFTER MIDNIGHT AND SPREAD EAST ACROSS NORTHERN NEBRASKA THROUGH THE
DAY ON SUNDAY WITH MVFR CEILINGS AND VISIBILITIES IN SNOW AND
BLOWING SNOW FROM KIEN TO KVTN TO KONL AND NORTH OF A LINE FROM KAIA
TO KLBF. STRONG NORTHWEST WINDS WILL PICK UP AFTER 2212Z AT 25 TO 35
MPH WITH GUSTS TO AROUND 45 MPH.
PREV DISCUSSION... /ISSUED 249 PM CST SAT JAN 21 2012/
DISCUSSION...
THE RUC CONTINUES TO INDICATE WIND ADVISORY CONDITIONS DEVELOPING
ACROSS NCNTL NEB THIS AFTERNOON AS LOW PRESSURE DEEPENS ACROSS THE
HIGH PLAINS. WIND SPEEDS SHOULD PEAK DURING THE LATE AFTERNOON AND
THEN FALL OFF WITH THE LOSS OF DAYTIME HEATING.
SOUTH WINDS CONTINUE OVERNIGHT AS A STRONG PACIFIC COLD FRONT
APPROACHES THE PLAINS. THIS FRONT WILL SWEEP THROUGH THE FCST AREA
SUNDAY MORNING AND LOW PRESSURE WILL CONSOLIDATE ACROSS THE
MIDWEST. STRONG NORTHWEST WINDS WILL DEVELOP BEHIND THE SFC LOW
ASSOCIATED WITH PACIFIC HIGH PRESSURE. A BLEND OF MAV AND MET
GUIDANCE PRODUCED HIGH END WIND ADVISORY CONDITIONS. DEUEL COUNTY
COULD PERHAPS REACH HIGH WIND CATEGORY BUT THAT IS LIKELY A RESULT
OF WEIGHTING FACTORS ASSOCIATED WITH THE DATA FROM KSNY. THE NAM
INDICATED GUSTS TO 55 MPH BUT ONLY ACROSS A SMALL PART OF CHERRY
COUNTY. WINDS ARE EXPECTED TO STAY UP EAST OF HIGHWAY 83 SUNDAY
EVENING FOR A FEW HOURS AS WRAP AROUND STRATUS PRODUCES A SHALLOW
MIXED LAYER. WIND SPEEDS SHOULD DECLINE BETWEEN 03Z AND 06Z AS THE
SFC LOW WILL PRESUMABLY BE FAR ENOUGH EAST FOR THE WINDS TO RELAX.
ELSEWHERE WINDS SHOULD DROP OFF QUICKLY AS A CLEARING LINE MOVES
EAST TO NEAR HIGHWAY 83 BY 00Z MONDAY.
A BLEND OF ECMWF...GEM REGIONAL...NAM AND GFS WAS USED FOR QPF
AMOUNTS WHICH ARE GENERALLY 1/10 OF INCH OR LESS. NOTE THE QPF IS
POST FRONTAL AND THE PTYPE IS SNOW. WITH THE H700MB LOW TRACKING
THROUGH THE NRN PLAINS...SNOW SHOWERS WOULD APPEAR TO BE THE
DOMINANT STORM MODE BUT WE MAY BE DEALING WITH A MIXED MODE AT TIMES.
THE NAM AND GFS ALSO KEEP THE FCST AREA MOSTLY DRY SO POPS ARE CHC
CATEGORY. HPC FAVORED THE GEM MODEL AND THE UKMET. THE ECMWF
APPEARED TO BE THE WETTER SOLN. THE GEM REGIONAL DEVELOPS A WEDGE
OF WARP AROUND QPF ACROSS THE ERN ZONES AMOUNTING TO 1/3 OF AN
INCH. GIVEN THE STRONG WINDS...SIGNIFICANT BLOWING SNOW WOULD
DEVELOP IF THAT WERE TO VERIFY.
HIGH PRESSURE SETTLES OVER THE FCST AREA MONDAY MORNING THROUGH TUESDAY.
A SPLIT IN THE WESTERLIES DEVELOPS SENDING A LARGE UPPER LEVEL CUTOFF
LOW THROUGH THE SRN PLAINS TUESDAY THROUGH FRIDAY. THIS SYSTEM
WILL HAVE LITTLE OR NO EFFECT ON THE SENSIBLE WEATHER ACROSS THE FCST
AREA EXCEPT TO HOLD PACIFIC HIGH PRESSURE IN PLACE. DEEP LOW PRESSURE
CIRCULATING THROUGH CNTL AND SRN CANADA WILL ALSO DRAW PACIFIC
HIGH PRESSURE THROUGH THE CNTL PLAINS WEDNESDAY AND THURSDAY
BEFORE ANOTHER STRONG PACIFIC COLD FRONT DROPS THROUGH THURSDAY
NIGHT OR FRIDAY.
THE FCST IS DRY MONDAY THROUGH SUNDAY. THE GFS IS AMPLIFYING A
DISTURBANCE THRU THE FCST AREA SATURDAY BUT IT APPEARS TO BE TOO
FAST. THE ECMWF HOLDS THAT FEATURE OFFSHORE IN THE PACIFIC.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY
FROM 6 AM CST /5 AM MST/ TO 6 PM CST /5 PM MST/ SUNDAY FOR
NEZ004-005-022>025-035>037-056>059-069>071-094.
WIND ADVISORY FROM 9 AM TO 9 PM CST SUNDAY FOR NEZ006>010-
026>029-038.
&&
$$
SHORT TERM/EXTENDED...POWER/CDC
AVIATION...POWER
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
605 PM CST SAT JAN 21 2012
.AVIATION...
A WINTER STORM IS APPROACHING WESTERN AND NORTH CENTRAL NEBRASKA
FROM THE WEST TONIGHT. MID AND HIGH CLOUDS PRESENT WITH VISUAL
FLIGHT RULES. SNOW WILL BEGIN OVER THE NORTHERN NEBRASKA PANHANDLE
AFTER MIDNIGHT AND SPREAD EAST ACROSS NORTHERN NEBRASKA THROUGH THE
DAY ON SUNDAY WITH MVFR CEILINGS AND VISIBILITIES IN SNOW AND
BLOWING SNOW FROM KIEN TO KVTN TO KONL AND NORTH OF A LINE FROM KAIA
TO KLBF. STRONG NORTHWEST WINDS WILL PICK UP AFTER 2212Z AT 25 TO 35
MPH WITH GUSTS TO AROUND 45 MPH.
&&
.PREV DISCUSSION... /ISSUED 249 PM CST SAT JAN 21 2012/
DISCUSSION...
THE RUC CONTINUES TO INDICATE WIND ADVISORY CONDITIONS DEVELOPING
ACROSS NCNTL NEB THIS AFTERNOON AS LOW PRESSURE DEEPENS ACROSS THE
HIGH PLAINS. WIND SPEEDS SHOULD PEAK DURING THE LATE AFTERNOON AND
THEN FALL OFF WITH THE LOSS OF DAYTIME HEATING.
SOUTH WINDS CONTINUE OVERNIGHT AS A STRONG PACIFIC COLD FRONT
APPROACHES THE PLAINS. THIS FRONT WILL SWEEP THROUGH THE FCST AREA
SUNDAY MORNING AND LOW PRESSURE WILL CONSOLIDATE ACROSS THE
MIDWEST. STRONG NORTHWEST WINDS WILL DEVELOP BEHIND THE SFC LOW
ASSOCIATED WITH PACIFIC HIGH PRESSURE. A BLEND OF MAV AND MET
GUIDANCE PRODUCED HIGH END WIND ADVISORY CONDITIONS. DEUEL COUNTY
COULD PERHAPS REACH HIGH WIND CATEGORY BUT THAT IS LIKELY A RESULT
OF WEIGHTING FACTORS ASSOCIATED WITH THE DATA FROM KSNY. THE NAM
INDICATED GUSTS TO 55 MPH BUT ONLY ACROSS A SMALL PART OF CHERRY
COUNTY. WINDS ARE EXPECTED TO STAY UP EAST OF HIGHWAY 83 SUNDAY
EVENING FOR A FEW HOURS AS WRAP AROUND STRATUS PRODUCES A SHALLOW
MIXED LAYER. WIND SPEEDS SHOULD DECLINE BETWEEN 03Z AND 06Z AS THE
SFC LOW WILL PRESUMABLY BE FAR ENOUGH EAST FOR THE WINDS TO RELAX.
ELSEWHERE WINDS SHOULD DROP OFF QUICKLY AS A CLEARING LINE MOVES
EAST TO NEAR HIGHWAY 83 BY 00Z MONDAY.
A BLEND OF ECMWF...GEM REGIONAL...NAM AND GFS WAS USED FOR QPF
AMOUNTS WHICH ARE GENERALLY 1/10 OF INCH OR LESS. NOTE THE QPF IS
POST FRONTAL AND THE PTYPE IS SNOW. WITH THE H700MB LOW TRACKING
THROUGH THE NRN PLAINS...SNOW SHOWERS WOULD APPEAR TO BE THE
DOMINANT STORM MODE BUT WE MAY BE DEALING WITH A MIXED MODE AT TIMES.
THE NAM AND GFS ALSO KEEP THE FCST AREA MOSTLY DRY SO POPS ARE CHC
CATEGORY. HPC FAVORED THE GEM MODEL AND THE UKMET. THE ECMWF
APPEARED TO BE THE WETTER SOLN. THE GEM REGIONAL DEVELOPS A WEDGE
OF WARP AROUND QPF ACROSS THE ERN ZONES AMOUNTING TO 1/3 OF AN
INCH. GIVEN THE STRONG WINDS...SIGNIFICANT BLOWING SNOW WOULD
DEVELOP IF THAT WERE TO VERIFY.
HIGH PRESSURE SETTLES OVER THE FCST AREA MONDAY MORNING THROUGH TUESDAY.
A SPLIT IN THE WESTERLIES DEVELOPS SENDING A LARGE UPPER LEVEL CUTOFF
LOW THROUGH THE SRN PLAINS TUESDAY THROUGH FRIDAY. THIS SYSTEM
WILL HAVE LITTLE OR NO EFFECT ON THE SENSIBLE WEATHER ACROSS THE FCST
AREA EXCEPT TO HOLD PACIFIC HIGH PRESSURE IN PLACE. DEEP LOW PRESSURE
CIRCULATING THROUGH CNTL AND SRN CANADA WILL ALSO DRAW PACIFIC
HIGH PRESSURE THROUGH THE CNTL PLAINS WEDNESDAY AND THURSDAY
BEFORE ANOTHER STRONG PACIFIC COLD FRONT DROPS THROUGH THURSDAY
NIGHT OR FRIDAY.
THE FCST IS DRY MONDAY THROUGH SUNDAY. THE GFS IS AMPLIFYING A
DISTURBANCE THRU THE FCST AREA SATURDAY BUT IT APPEARS TO BE TOO
FAST. THE ECMWF HOLDS THAT FEATURE OFFSHORE IN THE PACIFIC.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY
FROM 6 AM CST /5 AM MST/ TO 6 PM CST /5 PM MST/ SUNDAY FOR
NEZ004-005-022>025-035>037-056>059-069>071-094.
WIND ADVISORY FROM 9 AM TO 9 PM CST SUNDAY FOR NEZ006>010-
026>029-038.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
318 PM CST FRI JAN 20 2012
.SHORT TERM...THROUGH 00Z SUNDAY. MORNING UPPER AIR ANALYSIS
INDICATES ZONAL TO NORTHWESTERLY UPPER LEVEL FLOW PERSISTING
ACROSS MUCH OF THE CONUS. A 90KT MID LEVEL JET AXIS IS ALSO NOTED
EXTENDING FROM THE NORTHERN PLAINS TO THE MID-ATLANTIC. WATER
VAPOR IMAGERY INDICATES INCREASED MID LEVEL MOISTURE ACROSS THE
NORTHERN HALF OF THE CONUS...WITH A TROPICAL MID LEVEL MOISTURE
TAP ALSO NOTED APPROACHING NORTHWESTERN MEXICO FROM THE PACIFIC.
AT THE SURFACE A RIDGE OF HIGH PRESSURE REMAINS ANCHORED ACROSS
MUCH OF THE PLAINS...WITH AFTERNOON TEMPERATURES REMAINING IN THE
20S ACROSS MUCH OF THE CENTRAL PLAINS. WARMER AIR IS NOT FAR AWAY
HOWEVER AS A STRONG LOW LEVEL BAROCLINIC ZONE CURRENTLY EXTENDS
ALONG MUCH OF THE HIGH PLAINS...WITH A 20-30 DEGREE TEMPERATURE
GRADIENT CURRENTLY EXISTING WITHIN ABOUT 50 MILES ACROSS THE LOW
LEVEL BAROCLINIC ZONE.
MID AFTERNOON SATELLITE IMAGERY INDICATES ALTO-STRATUS OVER SOUTH
DAKOTA...MOVING SOUTH/SOUTHEAST INTO NORTHERN NEBRASKA. SATELLITE
IMAGERY ALSO INDICATES THE WESTERN EDGE OF THIS CLOUD DECK IS
ERODING...THUS MAKING IT APPEAR AS THOUGH WE STAND A BETTER CHANCE
OF RECEIVING A GLANCING BLOW ACROSS OUR NORTHEASTERN CWA RATHER THAN
BE COMPLETELY OVERTAKEN BY CLOUDS THIS EVENING. THIS ALSO FITS
WELL WITH THE LATEST RUC GUIDANCE...WHICH INDICATES ISENTROPIC
DOWN GLIDE IS INFILTRATING MUCH OF THE REGION. GIVEN ALL
THIS...WILL KEEP MOSTLY CLOUDY SKIES GOING ACROSS OUR NORTHEAST
THROUGH LATE EVENING...WITH LOCATIONS FARTHER SOUTHWEST HOPEFULLY
REMAINING WEST/SOUTHWEST OF THE CLOUD DECK. THIS WILL BE SOMETHING
FOR THE EVENING SHIFT TO MONITOR HOWEVER...JUST IN CASE THE CLOUD
DECK DOES MANAGE TO PUSH FARTHER SOUTHWEST THAN CURRENTLY
FORECAST.
CLEARING SKIES...DECREASING LOW LEVEL WINDS AND WEAK SURFACE RIDGING
SHOULD PROMOTE A DECENT DROP OFF IN TEMPERATURES TONIGHT AND
CURRENTLY HAVE 20-25 DEGREE DROP OFFS IN THE FORECAST...WHICH YIELDS
OVERNIGHT LOWS IN THE SINGLE DIGITS. THE SURFACE RIDGE IS EXPECTED
TO PUSH OFF TO THE EAST EARLY SATURDAY MORNING...WITH LOW LEVEL
RETURN FLOW REESTABLISHED ACROSS THE CENTRAL PLAINS BY SUNRISE
SATURDAY. THIS LOW LEVEL RETURN FLOW WILL PROMOTE WEAK LOW LEVEL
WAA WITHIN A SOUTH/SOUTHEASTERLY LOW LEVEL WIND FIELD. ~25 DEGREE
RISES ARE EXPECTED FOR THE MOST PART SATURDAY...WHICH YIELDS
SATURDAY AFTERNOON HIGHS IN THE UPPER 20S TO UPPER 30S ACROSS THE
CWA.
.LONG TERM...00Z SUNDAY THROUGH FRIDAY. THE START OF THE LONG TERM
PERIOD WILL FEATURE AN H5 RIDGE ACROSS THE CENTRAL UNITED STATES
WITH A LARGE TROUGH IN THE WEST. THERE IS GENERAL CONSENSUS THAT
THE WESTERN U.S. TROUGH WILL MOVE ACROSS THE CENTRAL PLAINS LATE
SATURDAY NIGHT INTO SUNDAY...HOWEVER FINDING AGREEMENT IN THE
DETAILS REMAINS ELUSIVE. DIFFERENCES REMAIN AMONGST THE VARIOUS
MODEL SOLUTIONS IN THE OVERALL STRENGTH/TIMING WHICH OBVIOUSLY HAVE
LARGE IMPACTS IN REGARDS TO POPS AND PRECIPITATION TYPE. AT THIS
POINT...HAVE CONTINUED TO CARRY A BLENDED MODEL SOLUTION WHICH GIVES
POPS GENERALLY IN THE 30 PERCENT RANGE ON SUNDAY. THIS ALSO LINGERS
A POP IN THE FAR EAST FOR SUNDAY EVENING WHICH ACCOUNTS FOR SOME OF
THE SLOWER MODEL SOLUTIONS...IN PARTICULAR THE ECMWF.
TEMPERATURES AND THE OVERALL THERMAL PROFILE REMAINS UNCERTAIN
THOUGH THE GENERAL TREND SEEMS TO KEEP WARMER H85 TEMPERATURES IN
THE MORNING...FOLLOWED BY COLDER AIR ARRIVING BEHIND A COLD FRONT IN
THE AFTERNOON. IF PRECIPITATION STARTS EARLY ENOUGH ON
SUNDAY...COULD SEE SOME POTENTIAL FOR LIGHT FREEZING RAIN DUE TO THE
EXPECTED BELOW FREEZING SURFACE TEMPERATURES...BUT WITH CONFIDENCE
STILL SO LOW IN THE DETAILS...WILL INSTEAD OPT FOR A RAIN/SNOW MIX.
IN FACT...COULD SEE SOME JUSTIFICATION FOR A RAIN/SNOW MIX MUCH OF
THE DAY DEPENDING ON THE TIMING OF THE COLDER AIR ALOFT. IN REGARDS
TO SUNDAY EVENING...WILL GO WITH SNOW SINCE MOST SOLUTIONS HAVE THE
COLD AIR IN PLACE BY THAT TIME.
ANOTHER CONCERN ON SUNDAY WILL BE STRONG WINDS BEHIND THE COLD
FRONT. STRONG PRESSURE RISES ARE SHOWN ACROSS THE FORECAST AREA.
MOMENTUM TRANSFER FROM NAM BUFR SOUNDINGS SUGGEST GUSTS COULD
APPROACH 40 KTS ACROSS MUCH OF THE FORECAST AREA...WITH EVEN
STRONGER WINDS POTENTIALLY TAKING HOLD IN THE SOUTHWEST. CURRENTLY
WE ARE HIGHLIGHTING THE STRONGER WINDS IN THE HAZARDOUS WEATHER
OUTLOOK...AND WILL LET THAT WORDING CONTINUE.
A DRY PERIOD TAKES HOLD AGAIN FOR OVERNIGHT SUNDAY INTO AT LEAST
EARLY TUESDAY AS ANOTHER H5 RIDGE DOMINATES THE CENTRAL PORTION OF
THE COUNTRY. THE NEXT WAVE MOVES THROUGH THE AREA TUESDAY INTO
TUESDAY NIGHT...HOWEVER AGAIN THERE ARE DIFFERENCES IN TIMING
AMONGST THE MODELS. WILL MAINTAIN CONTINUITY FOR NOW AND HOLD ONTO
THE MAIN PRECIPITATION CHANCES TUESDAY NIGHT. PRECIPITATION TYPE
COULD AGAIN BE AN WITH THE GFS COLDER THAN THE ECMWF. HAVE GONE
WITH A RAIN/SNOW COMBINATION IN THE SOUTH...BUT WILL GO ALL SNOW IN
THE NORTH WHERE EVEN THE WARMER ECMWF DROPS H85 TEMPERATURES BELOW
FREEZING TUESDAY EVENING.
THE REMAINDER OF THE FORECAST PERIOD APPEARS TO BE GENERALLY SUPPORT
ABOVE NORMAL TEMPERATURES WITH HIGHS PRIMARILY IN THE 40S. THE
WARMEST DAY COULD TURN OUT TO BE THURSDAY WITH SOME LOCATIONS
POTENTIALLY PUSHING THE 50 DEGREE MARK.
&&
.PREV DISCUSSION... /ISSUED 1143 AM CST FRI JAN 20 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS EXPECTED THROUGH THE NEXT
24 HOURS. HIGH LEVEL DECKS WILL LIKELY PERSIST THROUGH THIS
EVENING...WITH DIMINISHING CLOUDS EXPECTED THEREAFTER. SURFACE
WINDS WILL GENERALLY REMAIN LIGHT AND VARIABLE THROUGH THE NEXT
FEW HOURS...BUT BECOME MORE ESTABLISHED FROM THE NORTH AT AROUND
13KTS TOWARDS 21Z. SURFACE WINDS WILL THEN BECOME LIGHT AND
VARIABLE OVERNIGHT...AND THEN INCREASE FROM THE SOUTH DURING THE
DAY SATURDAY. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE
NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...BRYANT
LONG TERM...KING
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1253 PM EST FRI JAN 20 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE MIDWEST WILL MOVE TO THE EAST AND SETTLE OVER
NEW YORK STATE THIS AFTERNOON. ANY ONGOING LAKE EFFECT FLURRIES WILL
END AS THE HIGH BUILDS ACROSS THE AREA. LOW PRESSURE TRACKING
ACROSS THE LOWER OHIO VALLEY WILL BRING ANOTHER BATCH OF SNOWFALL
TONIGHT...BEFORE HIGH PRESSURE BRINGS ANOTHER PERIOD OF QUIETER
WEATHER WITH A WARM UP BY THE END OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE CONTINUES MOVE ACROSS THE REGION THIS AFTERNOON WITH
LOWERING INVERSION HEIGHTS WITH MAINLY FLURRIES NEAR THE LAKES.
TONIGHT...THE RIDGE WILL SLIDE OFF THE NEW ENGLAND COAST WHILE
LOW PRESSURE LIFTS NORTHEAST TOWARD THE LOWER OHIO VALLEY. WILL BE
SPEEDING UP THE TIMING OF THE PRECIP BY A FEW HOURS WITH THE NEXT
FORECAST UPDATE BASED OFF OF OBSERVATIONS AND HRRR RUNS. FORECAST SNOW
AMOUNTS LOOK GOOD...WITH A SUBTLE BUMP LATE TONIGHT ALONG THE
IMMEDIATE LAKE ONTARIO SHORE DUE TO SOME LAKE ENHANCEMENT...BUT
WITH GENERALLY LIGHT WINDS...THIS WILL BE HARDLY NOTICEABLE.
AN INVERTED SURFACE TROUGH EXTENDING NORTH OF THE PARENT LOW WILL
HELP TO FOCUS LOW LEVEL MOISTURE WHICH WILL BE INCREASING ON THE
NOSE OF A 40 TO 50 KNOT LOW LEVEL JET. THE INCREASING LOW LEVEL
THETA-E ADVECTION WILL COMBINE WITH ADDED LIFT FROM AN UPPER LEVEL
JET THAT WILL BE IN PLACE OVER NEW YORK STATE. THE RESULTING LARGE
SCALE LIFT WILL ALLOW SNOW TO SPREAD NORTH ACROSS THE AREA THIS
EVENING. STILL LOOKS LIKE THE HIGHEST SNOW ACCUMULATIONS WILL BE
SEEN ACROSS OUR THREE SOUTHERN TIER COUNTIES...WHERE A WINTER
WEATHER ADVISORY WILL BE ISSUED FOR LOW END ADVISORY
ACCUMULATIONS.
EAST OF LAKE ONTARIO...EXPECT A GENERAL SOUTH TO NORTH DECREASE IN
SNOWFALL TOTALS. A RELATIVELY WEAK PRESSURE GRADIENT OVER THE
LOWER LAKES MEANS THAT WINDS WILL NOT HAVE ANYWHERE NEAR THE
IMPACT THAT WAS FELT FELT THURSDAY.
WITH THE SYSTEM RACING EAST...WILL ALSO SPEED UP THE END TIME OF
THE PRECIP OVERNIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
LOW PRESSURE WILL CONTINUE TO TRACK EASTWARD ON SATURDAY...WITH
LINGERING SNOW EXPECTED TO END QUITE QUICKLY. MODEL SOUNDING
INDICATE A PERIOD OF LOW LEVEL MOISTURE WITH A WEAK UPSLOPE
NORTHERLY FLOW WHILE UPPER LEVEL MOISTURE RACES OFF TO THE EAST.
WILL ADD A POSSIBILITY OF SOME FREEZING DRIZZLE TO THE FORECAST.
WITH LACKING MOISTURE ALOFT...DO NOT EXPECT ANY LAKE EFFECT SATURDAY.
HIGH PRESSURE WILL BUILD ACROSS THE REGION SATURDAY NIGHT...THEN
THE HIGH WILL MOVE EASTWARD ACROSS NEW ENGLAND ON SUNDAY. LOWS ON
SATURDAY NIGHT ARE A BIT TRICKY...WITH THE NAM HANGING ONTO LOW
LEVEL MOISTURE THROUGH MUCH OF THE NIGHT...WHILE THE GFS IS MORE
BULLISH IN CLEARING THINGS OUT. FOR NOW...WILL HEDGE LOWS A
BIT...WITH BOTH LOW AND HIGH CLOUDS POSSIBLY LIMITING RADIATIONAL
COOLING. THE PERIOD WILL BE DRY...WITH WARMER TEMPERATURES BEHIND
THE HIGH ON SUNDAY. HIGHS SHOULD RISE INTO THE 30S ACROSS THE
REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A SIGNIFICANT AREA OF LOW PRESSURE WILL TRACK ACROSS THE UPPER LAKES
EARLY IN THE LONG TERM PERIOD...HOWEVER THE EXACT TRACK AND TIMING
OF THE LOW REMAINS UNCERTAIN. THE MAIN CHALLENGE HERE IS THAT SOME
MODELS (00Z EUROPEAN/GGEM) CLOSE OFF THE LOW ALOFT QUITE
QUICKLY...WHICH SLOWS THE TRACK AND INTENSIFIES THE LOW.
MEANWHILE...OTHER MODELS (00Z GFS/NAM) KEEP IT AN OPEN WAVE ALOFT
LONGER...LIFTING THE LOW TO OUR NORTH SIGNIFICANTLY FASTER. ITS
INTERESTING TO NOTE THAT LOOKING AT THE GFS ENSEMBLE MEMBERS...FEW
IF ANY ARE IN AGREEMENT WITH THE GGEM/EURO. THE EVENTUAL IMPACT ON
OUR REGION WILL LARGELY BE THE SAME...WITH TIMING THE MAIN ISSUE.
WILL CONTINUE TO USE A CONSENSUS AMONG THE GFS/GGEM/EUROPEAN.
REGARDLESS OF WHICH MODEL IS CORRECT ON TIMING...THIS SYSTEM WILL
BRING THREE THINGS TO WESTERN NEW YORK...WINDY CONDITIONS...RAIN
SHOWERS...AND WARM TEMPERATURES. MUCH LIKE LOW PRESSURE EARLIER THIS
WEEK...A STRONG SSE FLOW ALOFT WILL MOVE IN AHEAD OF THIS SYSTEM.
WINDS WILL INCREASE SUNDAY NIGHT AND MONDAY AHEAD OF THE
FRONT...MAINLY ACROSS HIGHER TERRAIN...AND IN FAVORABLE FUNNELING
LOCATIONS NEAR THE CHAUTAUQUA RIDGE AND BLACK RIVER VALLEYS. THEN
WINDS WILL SHIFT TO THE SW BEHIND THE FRONT...FOCUSING STRONGEST
WINDS ALONG THE NIAGARA FRONTIER. IN EACH CASE...WIND GUSTS TO
ADVISORY CRITERIA (IN EXCESS OF 45 MPH) ARE POSSIBLE...WITH EVEN
STRONGER GUSTS POSSIBLE DEPENDING ON HOW CLOSE THE LOW TRACKS...AND
HOW STRONG IT TURNS OUT TO BE.
AHEAD OF THIS FRONT...TEMPERATURES WILL WARM SIGNIFICANTLY. AS IS
OFTEN THE CASE...EXPECT ALL GUIDANCE IS UNDER-DOING THIS. EXPECT
WARMEST TEMPERATURES WILL LIKELY BE MONDAY MORNING...JUST AHEAD OF
THE CONSENSUS TIMING OF FROPA. WILL FORECAST WIDESPREAD UPPER
40S...WITH LOWER 50S ALONG THE LAKE ERIE SHORELINE AND NIAGARA
FRONTIER...WHERE DOWNSLOPING SHOULD AID IN WARMING.
OTHERWISE...EXPECT A ROUND OF SHOWERS WITH THE FRONT. THIS WILL POSE
A MODEST THREAT FOR FLOODING...AS RECENT SNOWFALL IS LIKELY TO MELT.
HOWEVER...QPF WITH THE FROPA DOES NOT APPEAR TO BE TOO GREAT...WHICH
MAY LIMIT RISES IN THE CREEKS. WILL ALSO HAVE TO WATCH FOR ICE BUILD
UP...WITH RECENT CREEK RISES CAUSING SOME MODEST ICE BUILD UPS ON A
FEW CREEKS. THIS EVENT MAY SWEEP OUT THE CREEKS...LEAVING MANY ICE
FREE IN LATE JANUARY.
FOLLOWING THE PASSAGE OF MONDAY`S COLD FRONT...SEASONABLY COOLER AIR
WILL FILTER BACK INTO THE REGION MONDAY NIGHT AND TUESDAY ALONG WITH
A CYCLONIC FLOW OF FAIRLY DEEP WRAPAROUND MOISTURE. THIS WILL RESULT
IN A CONTINUATION OF SCATTERED SHOWERS...WITH PTYPE TRANSITIONING
BACK FROM RAIN TO SNOW SHOWERS AS TEMPS COOL. THIS SAID...TEMPS
ALOFT NOW ONLY LOOK TO DROP TO ABOUT -10C AT THEIR COLDEST ON
TUESDAY...WHICH MAY MAKE IT TOUGH FOR ANY LAKE RESPONSE AT ALL TO
DEVELOP...EVEN OFF OF LAKE ONTARIO.
AFTER THIS...INCREASING RIDGING AND SUBSIDENCE WILL THEN BRING A
RETURN TO DRY CONDITIONS TUESDAY NIGHT AND WEDNESDAY...BEFORE THE
NEXT IN A SERIES OF QUICK-MOVING SYSTEMS APPROACHES THE AREA ON
THURSDAY. WITH A GENERALLY MILD AND PROGRESSIVE ZONAL FLOW
CONTINUING THROUGH MID TO LATE NEXT WEEK...TEMPS THROUGH THE BALANCE
OF THE EXTENDED WILL TEND TO REMAIN ON THE MILD SIDE OF NORMAL AND
FAVORABLE FOR MORE OF A RAIN OR RAIN/SNOW MIX...AND RATHER
UNFAVORABLE FOR ADDITIONAL LAKE EFFECT SNOW.
A SLOW MOVING LOW IS LIKELY TO DEVELOP IN THE GULF STATES ON
WEDNESDAY AND THURSDAY. THIS LOW MAY LIFT TOWARD OUR REGION...OR IT
MAY STAY TO THE SOUTH ON THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL DETERIORATE THIS EVENING TO IFR IN -SN AS A LOW
PRESSURE SYSTEM MOVES ACROSS THE TN RIVER VALLEY AND OFF THE MID
ATLANTIC COAST BY 18Z SATURDAY. SOME FZDZ IS POSSIBLE FOR A FEW
HOURS ON THE BACK SIDE OF THE SYSTEM WITH CONTINUED IFR CONDITIONS
IN AN NORTHERLY UPSLOPE FLOW. SOME IMPROVEMENT POSSIBLE LATE
SATURDAY.
OUTLOOK...
SUNDAY...VFR.
MONDAY...MVFR/IFR WITH RAIN SHOWERS LIKELY.
TUESDAY...MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR.
&&
.MARINE...
HIGH PRESSURE OVER THE MIDWEST WILL MOVE TO THE EAST AND CREST OF
NEW YORK STATE THIS AFTERNOON. THIS WILL ALLOW NORTHWEST WINDS TO
SUBSIDE FROM WEST TO EAST AS THE DAY WEARS ON.
AN AREA OF LOW PRESSURE IS FORECAST TO LIFT NORTH TOWARD THE LOWER
OHIO VALLEY TONIGHT...THEN SLIDE OFF THE VIRGINA COAST ON SATURDAY.
BASED ON THIS TRACK...LOOKS LIKE THE PRESSURE GRADIENT OVER THE
LOWER LAKES WILL STAY WEAK ENOUGH TO PRECLUDE SMALL CRAFT ADVISORY
CONDITIONS FROM SETTING UP. SOUTHERLY WINDS WILL START TO PICK UP
AGAIN ON SUNDAY AHEAD OF YET ANOTHER APPROACHING LOW PRESSURE
SYSTEM.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 6 AM EST
SATURDAY FOR NYZ019>021.
MARINE...NONE.
&&
$$
SYNOPSIS...TJP/ZAFF
NEAR TERM...TJP/ZAFF
SHORT TERM...APFFEL/ZAFF
LONG TERM...APFFEL/JJR
AVIATION...ZAFF
MARINE...APFFEL/TJP/ZAFF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
348 AM EST FRI JAN 20 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW SQUALLS TO THE REGION TONIGHT AND
EARLY FRIDAY MORNING. FRIDAY NIGHT, A STRONGER STORM WILL MOVE
THROUGH THE MID ATLANTIC STATES. THIS STORM WILL BRING MODERATE
ACCUMULATING SNOW TO THE SOUTHERN TIER AND CATSKILLS OF NEW YORK,
AND NORTHEASTERN PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 PM UPDATE...SOME BIG CHANGES WITH THIS UPDATE. FIRST OFF...WE
GOT A REPORT OF 8" OF SNOW IN BOONVILLE FROM A SPOTTER THROUGH
FACEBOOK. WE CONFIRMED THIS AMOUNT WITH A FEW REPORTS OF AROUND 6"
IN THE SAME AREA. WITH CRITERIA FOR A WARNING BEING 7" IN 12 HOURS
OR 9" IN 24 HOURS...AND EXPECTING MORE SNOW DUE TO LAKE EFFECT
LATER TONIGHT...AN UPGRADE TO A WARNING WAS AN EASY CALL. TOUGHER
CALL ON WHAT TO CALL IT (LAKE EFFECT VS. WINTER STORM). AFTER
COORDINATION WITH BUFFALO AND ALBANY...DECIDED TO GO THE WINTER
STORM ROUTE SINCE THIS WOULD BE AN UPGRADE FROM THE ADVISORY WE
ALREADY HAD OUT...AND JUST MENTION THE TRANSITION TO LAKE EFFECT
SNOW IN THE PRODUCT ITSELF. FARTHER SOUTH AND EAST...AN AREA OF
SNOW HAS PRODUCED 1 TO 3 INCHES OF SNOW IN ISOLATED AREAS OF
CORTLAND...CHENANGO...BROOME...DELAWARE COUNTIES ALONG WITH SOME
OF NEPA. THIS IS IN ASSOCIATION WITH THE LEFT EXIT REGION OF A
JET. THESE AREAS MAY APPROACH 4" IN ISOLATED AREA WITH ANOTHER
INCH EXPECTED OVERNIGHT FROM A SQUALL LINE...BUT THE AVERAGE FOR
THIS WHOLE AREA WILL BE CLOSER TO 1 TO 2 INCHES...THUS NO
ADVISORY WILL BE ISSUED.
LAST BUT NOT LEAST...THE SQUALL LINE WE HAVE BEEN TRACKING IS NOW
MOVING THROUGH CENTRAL NY. THE LINE HAS HELD TOGETHER QUITE NICELY
AND WE STILL EXPECT A QUICK HALF TO 1.5 INCHES OF SNOW IN A BURST.
WE CONTINUE TO STRESS THAT THESE AMOUNTS ARE NOT HIGH BUT WILL
CREATE SLICK TRAVEL IN A SHORT PERIOD OF TIME. THE PREVIOUS AFD IS
BELOW...
730 PM UPDATE...THE FORECAST IS IN PRETTY GOOD SHAPE. SOME SNOW
HAS DEVELOPED NEAR THE BINGHAMTON AND NORWICH AREAS RECENTLY. THIS
IS RESPONSE TO A JET STREAK AT AROUND 400 MB ACROSS WEST CENTRAL
PA. THE SNOW OVER CENTRAL PA IS BEING CAUSED BY THE RIGHT ENTRANCE
REGION TO THE JET...WITH OUR LIGHT SNOW BEING CAUSED BY THE LEFT
EXIT REGION. AS THIS JET STREAK SLIDES SOUTHEAST AND WEAKENS
THROUGH 9 PM...EXPECT THE SNOW TO DIMINISH AND MOVE EAST.
NOW TO THE REAL ACTION. AN INTENSE LINE OF SNOW CONTINUES TO MARCH
EAST ACROSS WESTERN NY AND IS JUST ON THE DOORSTEPS OF OUR AREA.
OUR FIRST SPS HAS BEEN ISSUED AND WE WILL LIKELY TO CONTINUE TO
ISSUE SPECIAL WEATHER STATEMENTS THROUGH MIDNIGHT AS THE LINE HEADS
EAST. SNOWFALL AMOUNTS OF AN INCH OR SO ARE POSSIBLE WITH THE
LINE...BUT IT WILL BE THE FACT THAT THE SNOW WILL FALL IN SUCH A
SHORT PERIOD OF TIME THAT IS CAUSE FOR CONCERN. ROUGH TIMING IS
BETWEEN 8 PM AND 10 PM FOR THE WESTERN PART OF THE CWA...ALONG
I-81 IN NY BETWEEN 10 PM AND MIDNIGHT...AND THE SOUTHEASTERN CWA
BETWEEN MIDNIGHT AND 3 AM. THE MODELS DO SHOW THE LINE WEAKENING A
BIT AS IT MARCHES EAST...SO WE MAY SEE THE BIGGEST IMPACT TO OUR
CWA COMING BETWEEN NOW AND MIDNIGHT. THE REST OF THE FORECAST IS
IN GOOD SHAPE REGARDING THE TRANSITION TO LAKE EFFECT SNOW LATER
TONIGHT. THE PREVIOUS AFD IS BELOW...
EVENT #1 IS VISIBLE ON RADAR, WITH BUF SHOWING ENHANCED RETURNS
OVER THE WESTERN EDGE OF LAKE ONTARIO. THIS SHARP COLD FRONT IS
WELL DEPICTED BY THE LATEST RUC13 LOW LEVEL LAPSE RATES, AND WE
ARE USING THIS MESOSCALE MODEL TO FORECAST A POTENTIAL SQUALL
MOVING THROUGH THE FINGER LAKES AND CENTRAL SOUTHERN TIER BY 2-4Z.
BASED ON CURRENT RADAR UPSTREAM AND THE STEEP LAPSE RATES, I CAN
SEE A QUICK INCH OR TWO FROM THIS SQUALL ALONE BEING POSSIBLE. WE
WILL NEED TO CONTINUE TO MONITOR THIS FOR A POTENTIAL SPS TONIGHT.
ONCE THE COLD FRONT MOVES THROUGH, WINDS SHIFT OFF THE LAKE
OVERNIGHT AND BRING A SOLID 2 TO 4 INCHES OF ADDITIONAL SNOW TO
NORTHERN ONEIDA.
NOW BELIEVE THE BAND WILL AFFECT EXTREME NORTHERN ONONDAGA,
NORTHWESTERN MADISON, AND SOUTHWESTERN ONEIDA WITH 1 TO 3 INCHES
OF SNOW. THIS ON TOP OF THE 1 TO 2 INCHES OF SYNOPTIC SNOWFALL
JUSTIFIES AN ADVISORY, THOUGH ONLY A SMALL PORTION OF THE NEW
ADVISORY COUNTIES WILL BE AFFECTED.
A COMBINATION OF SHEAR AND DECREASING LAPSE RATES IN ASSOCIATION
WITH FAST APPROACHING ANTICYCLONE WILL KILL OFF THE LAKE MACHINE
BY MID MORNING. A FEW LIGHT SNOW SHOWERS MAY PERSIST INTO EARLY
AFTERNOON, BUT THE ADVISORY WILL NO LONGER BE NEEDED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
EVENT #2 HAS A STORM SYSTEM SLIDING THROUGH THE MID ATLANTIC
REGION FRIDAY NIGHT INTO SATURDAY. GFS REMAINS THE QUICKEST TO
MOVE SNOW IN FRIDAY EVENING, WITH THE EURO AND NAM A FEW HOURS
SLOWER. HOWEVER THERE IS GOOD AGREEMENT IN STORM TRACK, STRENGTH,
AND QPF.
THE MODELS WERE COLDER THIS MORNING, BUT THE TREND ALL WINTER HAS
BEEN FOR THE MODELS TO BRING THE STORM CENTERS TO THE NORTH IN THE
FINAL RUNS, WITH WARM AIR ENCROACHING FROM THE SOUTH. THERE ARE
SOME HINTS THAT SOME SLEET COULD MIX IN WITH THE SNOW OVER OUR FAR
SOUTHERN FA, BUT RIGHT NOW THE MODEL SOUNDINGS ARE MOST INDICATIVE
OF SNOW.
THE MODEL QPF LOOKS A LITTLE ON THE HIGH SIDE. HOWEVER EVEN WITH A
REDUCTION IN QPF WE ARE VERY CLOSE TO ADVISORY ACCUMS OVER THE
SOUTHERN THIRD OF THE FA.
THE STORM PULLS OUT QUICKEST ON THE GFS, WITH THE EURO AND NAM
AGAIN A FEW HOURS SLOWER. EITHER WAY THE EVENT SHOULD BE DONE BY
LATE AFTERNOON SATURDAY, IF NOT SOONER. WINDS SHIFT AROUND TO A
NORTHEASTERLY DIRECTION, SO IT DOES NOT APPEAR AS THOUGH OUR FA
WILL BE DEALING WITH POST EVENT LAKE SNOWS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
330 PM UPDATE...
HGTS BLD SUN NGT WITH MID AND LL WAA AHD OF A WRN LAKES LOW. LGT
PCPN SEEM PSBL WITH MUCH UNCERTAINTY ABT THE TEMP PROFILE. MIXED
PCPN SEEMS LIKELY WITH SFC TEMPS NEAR OR BLO FRZG...SO SOME FRZG
RAIN PSBL. LOW MVES SLWLY EAST AS AN OCCLUDED FNT RACES EWRD THRU
THE OH VLY AND WRN NY. TIMING PUSHES THE FNT THRU THE AREA MON
EVE...BUT WITH MODIFIED COLD AIR PUSHING IN FROM THE SW...DO NOT
XPCT A DRAMATIC TEMP DROP LATE MON INTO TUE. UPR LOW LIFTS NORTH
TUE AS THE TROF AXIS PASSES. AIR IS JUST NOT THAT COLD WITH H8
TEMPS FCSTD IN THE -6C TO -8C RANGE. XPCT SOME MOISTURE WITH THE
UPR TROF AND SOME MRGNL LE SNOW SHWRS INTO WED. LATE WED A SFC HI
OVER THE OH VLY BLDS IN BUT WITH ZONAL FLOW OVER THE FCST
AREA...TEMPS RATHER NEUTRAL AND WITH A WEAK SFC TROF AND APRCHG
WC...JUST SOME LGT PCPN IN THE AREA FOR THE END OF THE PD.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
A BRIEF PERIOD OF HIGH PRESSURE WILL BUILD LATER THIS MORNING.
HOWEVER, BEFORE IT DOES, A LAKE EFFECT SNOW BAND WILL MOVE SOUTH
FROM NORTHERN ONEIDA COUNTY AND AFFECT RME AND SYR TAFS SITES. SO
FAR, IT HAS BEEN STUBBORN TO MOVE, SO TIMING HAS BECOME VERY
UNCERTAIN. STILL EXPECTING IT TO MOVE SOUTH BEFORE SUNRISE. AS IT
DOES, IT WILL WEAKEN, THEN DISSIPATE. THIS WILL ALLOW FOR VFR
CONDITIONS FOR MOST OF THE DAY TODAY. ANOTHER LOW PRESSURE SYSTEM
WILL BRING ANOTHER ROUND OF SNOW SHOWERS TONIGHT. THIS LOW,
HOWEVER, IS EXPECTED TO STAY WELL SOUTH OF THE FORECAST AREA. THIS
WILL CAUSE THE HEAVIER SNOW TO BE IN THE AVP AREA. BGM AND ELM
WILL ALSO LIKELY SEE A FEW INCHES OF SNOW TONIGHT. THIS SYSTEM
WILL TAKE MOST OF SATURDAY TO MOVE THROUGH BEFORE HIGH PRESSURE
BUILD AGAIN SATURDAY NIGHT.
WINDS WILL BE OUT OF THE WEST TO NORTHWEST THIS MORNING AROUND
10KTS, WITH SOME LOCATIONS CLOSER TO 15KTS. AS HIGH PRESSURE
BUILDS IN TODAY, THE WINDS WILL TAPER OFF AND, SHOULD GO TO LIGHT
AND VARIABLE TONIGHT.
.OUTLOOK...
FRI NGT...VFR BECOMING IFR AFTER MIDNIGHT WITH WIDESPREAD SNOW
MOVES IN.
SAT...IFR IN SNOW DURING THE MORNING IMPROVING TO VFR DURING THE
AFTN.
SAT NGT AND SUN...MAINLY VFR.
SUN NGT TO MON NGT..MVFR POSSIBLE IN RAIN OR SNOW.
TUE...MVFR IN SNOW SHWRS
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
NYZ018-036-037.
WINTER STORM WARNING UNTIL 9 AM EST THIS MORNING FOR NYZ009.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP/HEDEN
SHORT TERM...DJP
LONG TERM...DGM
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
940 PM EST SAT JAN 21 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH AND MOVE ACROSS THE COASTAL CAROLINAS
LATE TONIGHT...STALLING WELL SOUTH OF THE AREA SUNDAY. COOL AND
MOIST CONDITIONS WILL PREVAIL ON SUNDAY AS HIGH PRESSURE WEDGES IN
FROM THE NORTH. THE STALLED FRONT EARLIER WILL RETURN NORTH AS A
WARM FRONT...CROSSING THE AREA MONDAY. THE NEXT COLD FRONT IS
EXPECTED TO CROSS THE REGION MONDAY NIGHT. HIGH PRESSURE WILL FOLLOW
TUESDAY INTO MID WEEK...WITH ANOTHER FRONTAL SYSTEM APPROACHING FROM
THE WEST LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM SATURDAY...LOW LEVEL STABILITY ACROSS THE ILM CWA HAS
DIMINISHED THE THUNDER THREAT...LEAVING LIGHT RAIN AND EMBEDDED
HEAVIER SHOWERS AHEAD OF THE APPROACHING COLD FRONT DROPPING
SOUTHWARD. THE MAJORITY OF THE PCPN WILL END BY MID EVENING...
LEAVING PATCHY LIGHT RAIN OR DRIZZLE...ESPECIALLY AFTER THE COLD
FRONTAL PASSAGE. THE FRONTAL INVERSION WILL RESULT WITH A STRATUS
DECK AROUND 1 K FT INTO THE EARLY SUNDAY MORNING HRS. N-NE SFC WINDS
IN THE WAKE OF THE CFP WILL INCREASE TO 5 TO 10 MPH WITH A FEW GUSTS
APPROACHING 15 MPH. THIS LOW LEVEL MIXING WILL KEEP ANY FOG FROM
BECOMING WIDESPREAD AND A SERIOUS THREAT TO VSBY. LOOKING AT THE
LATEST HRRR WIND FIELD...IT WILL TAKE ROUGHLY FROM 10 PM THIS
EVENING TIL 3 AM SUNDAY FOR THE COLD FRONT TO PUSH ENTIRELY
ACROSS THE ENTIRE ILM CWA. CURRENT MIN FORECAST HAS BEEN MASSAGED
AND TWEAKED TOWARD THE LOWER SIDE OF MOS GUIDANCE...WITH SFC
DEWPOINTS ALSO FOLLOWING SUIT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 PM SATURDAY...COOL...CLOUDY AND MOIST DAY IN STORE FOR
SUNDAY AS A SHORT-LIVED COLD AIR DAMMING SITUATION SETS UP. STEADY
NE FLOW AT THE SURFACE AND EXTENSIVE CLOUD COVER WILL KEEP
AFTERNOON TEMPERATURES A DEGREE OR SO EITHER SIDE OF 50 MOST
LOCATIONS. AS IS TYPICAL FOR THIS TYPE OF PATTERN...EXPECT PATCHY
DRIZZLE OR LIGHT RAIN TO MAKE APPEARANCES AT TIMES...WITH MINIMAL
QPF DUE TO WEAK FORCING AND SHALLOW NATURE OF MOISTURE. THERE WILL
BE A LIMITED DIURNAL RANGE OF TEMPERATURES...WITH LOWS MAINLY IN
THE 40S OVERNIGHT.
WEDGE PATTERN WILL ERODE EARLY ON MONDAY AS A COLD FRONT AND
ASSOCIATED UPPER TROUGH APPROACH FROM THE WEST. FLOW WILL TURN TO
THE SOUTH AND THEN SW MONDAY AFTERNOON...ALLOWING FOR A BIG WARM
UP FROM THE PREVIOUS DAY. EXPECT HIGHS IN THE UPPER 60S TO AROUND
70...ABOUT 20 DEGREES HIGHER THAN ON SUNDAY. FRONT WILL MOVE
ACROSS THE EASTERN CAROLINAS MONDAY EVENING AND OVERNIGHT AND WILL
BE OFFSHORE BY AROUND DAYBREAK ON TUESDAY. MOISTURE WILL BE
LIMITED WITH THIS SYSTEM AND BEST UPPER SUPPORT WILL PASS WELL TO
THE NORTH...SO EXPECT ONLY ISOLATED TO SCATTERED CONVECTION TO
ACCOMPANY FROPA. NOT MUCH IN THE WAY OF COLD ADVECTION WITH THIS
FRONT...SO EXPECT LOWS WILL RANGE FROM THE MID 40S INLAND TO
AROUND 50 AT THE COAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 2:30 PM SATURDAY...MAIN FEATURE FOR THE EXTENDED CONTINUES
TO BE THE CUTOFF MEANDERING ABOUT THE SOUTHWEST AND WHEN IT GETS
KICKED OUT. THE LATEST OPERATIONAL RUN OF THE GFS HAS TRENDED MUCH
SLOWER WHILE PREVIOUS RUNS MAINTAINED MORE OF A ZONAL FLOW. HPC
CONTINUES TO FAVOR THE ECMWF SUITE OF PRODUCTS BASED ON MORE
CONSISTENCY. THESE ARE A BIT SLOWER WITH THE SYSTEM BUT OVERALL
ARE SIMILAR TO THIS TIME YESTERDAY. THE ONLY FORECAST CHANGES WITH
THIS PACKAGE WERE TO DELAY THE POPS SLIGHTLY MAINTAINING THE SAME
STRATEGY AS YESTERDAY WITH INCREASING VALUES FROM LATE THURSDAY
THROUGH THE NEW DAY SATURDAY. ONLY MINOR TWEAKS TO TEMPERATURES
WITH A SLIGHT INCREASE ACROSS THE BOARD TO MATCH HPC NUMBERS AND
ADJACENT OFFICES.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...BACK END OF THE PRECIP IS PROGRESSING A BIT FASTER TO
THE EAST THAN PREVIOUSLY THOUGHT. LOOK FOR MOST OF THE PRECIP TO
EXIT THE COAST BY 02Z...WITH A WIND SHIFT TO THE NORTH SHORTLY
AFTER. FAIRLY HIGH CONFIDENCE FOR POST FRONTAL STRATUS TO SETTLE IN
AT ALL TERMINALS BY 04-05Z...CONTINUING FOR MOST OF THE FORECAST
PERIOD. THERE IS A SLIGHT CHANCE THAT THERE WILL BE ENOUGH MIXING TO
SCATTER OUT THE IFR BY SUNDAY AFTERNOON...BUT IT SHOULD BE BRIEF.
WINDS WILL CONTINUE TO VEER TO THE NORTHEAST BY SUNDAY
MORNING...GUSTY AT TIMES...BUT FAIRLY STEADY FOR MOST GIVEN THE POST
WEDGE SITUATION.
EXTENDED OUTLOOK...IFR WILL PERSIST THROUGH MONDAY MORNING.
ANTICIPATE VFR TO DEVELOP MONDAY LATE WITH A SLIGHT CHANCE OF
SHOWERS. VFR TUESDAY. LOW CONFIDENCE FOR MORNING FOG WEDNESDAY AND
THURSDAY MORNINGS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM SATURDAY...SMALL CRAFT EXERCISE CAUTION IS IN EFFECT.
THE COLD FRONT LIES JUST ON THE NORTHERN DOORSTEPS OF THE ILM CWA
PER LATEST MSAS. HRRR HOURLY WIND FORECAST HIGHLIGHTS THE COLD
FRONTAL PASSAGE TO OCCUR BETWEEN 10 PM TONIGHT AND 3 AM SUNDAY.
SFC WINDS AHEAD OF THE CF...HAVE ALREADY BEGUN TO VEER FROM SW TO W
FROM CAPE FEAR NORTHWARD. DURING THE TRANSITIONING PHASE DURING THE
COLD FRONTS PASSAGE...SPEEDS COULD DROP TO 10-15 KT. SFC PG TO
TIGHTEN QUICKLY AFTER THE CFP...AND WILL RESULT IN 15 TO 20 KT
SPEEDS WITH A FEW GUSTS UP TO 25 KT. THE SCEC MAY NEED TO BE
EXPANDED INTO SUNDAY DAYLIGHT HRS IF THE SFC PG REMAINS TIGHTENED
FROM THE 1030+ HIGH RIDGING SOUTHWARD. THREE TO 5 FT WIND DRIVEN
WAVES WILL DOMINATE THE SIGNIFICANT SEAS ACROSS THE COASTAL
WATERS...WITH PERIODS AVERAGING 5 TO 7 SECONDS. CAN NOT RULE OUT AN
ISOLATED 6 FOOTER ACROSS THE OUTER WATERS VICINITY OF FRYING PAN
SHOALS BUT NOT ENOUGH OCCURRENCE TO PLACE 6 FOOTERS IN SIG SEAS.
SEAS WILL BE ADVERTIZED IN THE 3-5 FT RANGE THRUOUT OVERNIGHT. WITH
A DIFFERENT FETCH DIRECTION AND LENGTH AFTER FROPA...SEA HEIGHTS
WILL NEED TO BE ADJUSTED. PATCHY LIGHT RAIN OR DRIZZLE WILL DOMINATE
THE PCPN THREAT OVERNIGHT. LOW STRATUS CLOUD DECK MAY LIMIT VSBYS TO
WHERE GPS AND DEPTH FINDERS ARE UTILIZED FOR THE NEAR SHORE WATERS
AND THE INTRA-COASTAL WATERWAY.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 PM SATURDAY...NELY FLOW OVER THE WATERS ON SUNDAY WILL
TURN SWLY ON MONDAY AS A COLD FRONT APPROACHES FROM THE WEST.
WINDS WILL RANGE FROM 15 TO 20 KTS EARLY ON SUNDAY BEFORE BECOMING
LIGHT AND VEERING TO THE SE OVERNIGHT WITH THE APPROACH OF THE
COLD FRONT. WINDS WILL PICK UP AGAIN MONDAY AFTERNOON BACK IN THE
15 TO 20 KT RANGE FROM THE SW. COLD FRONT MAY MOVE OFFSHORE BY
AROUND DAYBREAK ON TUESDAY. SEAS WILL RANGE FROM 3 TO 5 FT FOR
MUCH OF THE PERIOD.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 2:30 PM SATURDAY...WESTERLY FLOW INITIALLY IN THE WAKE OF THE
COLD FRONT. A SECONDARY PUSH OCCURS LATE TUESDAY INTO WEDNESDAY
WHICH WILL TURN WINDS TO THE NORTHEAST. FINALLY RETURN FLOW SETS UP
THURSDAY AS A SYSTEM TAKES SHAPE WELL TO THE SOUTHWEST. OVERALL WIND
SPEEDS SHOULD REMAIN MODEST WITH THE POSSIBLE EXCEPTION OF LATE INT
HE PERIOD WHEN THE SOUTHWEST FLOW SURGES. SEAS WILL REFLECT THE
MODEST WINDS WITH AROUND TWO FEET FOR TUESDAY AND WEDNESDAY
INCREASING SLIGHTLY THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DOUGH
SHORT TERM...RICHARDK
LONG TERM...STEPHENK
AVIATION...HENRYL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
640 PM EST SAT JAN 21 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH AND MOVE ACROSS THE COASTAL CAROLINAS
LATE TONIGHT...STALLING WELL SOUTH OF THE AREA SUNDAY. COOL AND
MOIST CONDITIONS WILL PREVAIL ON SUNDAY AS HIGH PRESSURE WEDGES IN
FROM THE NORTH. THE STALLED FRONT EARLIER WILL RETURN NORTH AS A
WARM FRONT...CROSSING THE AREA MONDAY. THE NEXT COLD FRONT IS
EXPECTED TO CROSS THE REGION MONDAY NIGHT. HIGH PRESSURE WILL FOLLOW
TUESDAY INTO MID WEEK...WITH ANOTHER FRONTAL SYSTEM APPROACHING FROM
THE WEST LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM SATURDAY...LOW LEVEL STABILITY ACROSS THE ILM CWA HAS
DIMINISHED THE THUNDER THREAT...LEAVING LIGHT RAIN AND EMBEDDED
HEAVIER SHOWERS AHEAD OF THE APPROACHING COLD FRONT FROM THE NORTH.
CLOSEST THUNDER WILL BE ACROSS THE CHS CWA AND THE OFFSHORE WATERS
ALONG THE WEST WALL OF THE GULF STREAM. AS THE COLD FRONT DROPS
THROUGH THE FA OVERNIGHT...LOOK FOR POST FRONTAL PATCHY LIGHT RAIN
OR DRIZZLE TO PREVAIL. DUE TO THE RAIN COOLED AIR ESPECIALLY OVER
THE WESTERN HALF OF THE ILM CWA...ADJUSTED INITIAL...23-00Z...HOURLY
TEMPS/DEWPOINTS LOWER AND THEN TRENDED TOWARDS OVERNIGHT LOWS. HRRR
MODEL HAS BEEN FOLLOWED CLOSELY TO ACCOUNT THE PLACEMENT OF THE
HIGHER POPS DURING THE OVERNIGHT.
PREVIOUS DISCUSSION.................................................
AS OF 300 PM SATURDAY...POTENT SHORTWAVE CLEARLY EVIDENT ON WV
IMAGERY PUSHING ACROSS NORTH GEORGIA ATTM WILL PIVOT THROUGH THE
AREA TONIGHT. ADDITIONALLY...COLD FRONT MOVING EAST THROUGH UPSTATE
SC WILL BECOME MORE E-W ORIENTED AND DROP SOUTHWARD OVERNIGHT. THESE
TWO WILL WORK TOGETHER TO CONTINUE THUNDERSTORMS THROUGH TONIGHT.
LATEST REGIONAL MOSAIC SHOWS A LINE OF STRONGER THUNDERSTORMS FROM
APPROXIMATELY COLUMBIA, SC SOUTHWEST TO MACON, GA. THE STRONGEST
STORMS ARE COLLOCATED WITH ENHANCED LIFT FROM THE PUNCH OF THE S/W
TROUGH...AND EXPECT THE DEEPEST CONVECTION WILL PERSIST IN THIS
MANNER. ALTHOUGH THE SHORTWAVE IS PROGGED TO WEAKEN AS IT MOVES
NORTHEAST TONIGHT...IT APPEARS TO BE SLIGHTLY STRONGER THAN GUIDANCE
HAD SUGGESTED WHICH MAY PERMIT CONVECTION TO CONTINUE LONGER. LATEST
RUC AND HRRR ENSEMBLE REFLECTIVITY HAVE A GOOD HANDLE ON ONGOING
SITUATION...SO HAVE USED A BLEND OF THESE FOR TIMING OF CONVECTION.
VERY LITTLE INSTABILITY...LI`S GREATER THAN 0...AND WINDS ON THE LTX
VWP OF ONLY 30 KTS AT 2 KFT ALL PROMOTE THE CONTINUED IDEA OF ONLY
LIMITED SEVERE POTENTIAL DURING THE NEXT SEVERAL HOURS...EVEN THOUGH
THE SOUTHERN HALF OF THE CWA REMAINS IN A SLIGHT RISK.
STILL...FORECAST GUIDANCE DEVELOPS SOME 7 C/KM ML LAPSE RATES...LI`S
TO -2...AND 0-6 KM SHEAR SUPPORTIVE OF MULTICELL STRUCTURES. HAVE
KEPT SCT TSTMS IN WX GRIDS WITH CATEGORICAL POP FROM WEST TO EAST
THROUGH 10 PM. CANNOT RULE OUT ONE OR TWO WARNINGS TONIGHT...BUT
EXPECT PRIMARILY SUB-SEVERE WIND AND ISOLATED SMALL HAIL.
FROPA OCCURS OVERNIGHT...AND HAVE ADJUSTED MIN TEMPS DOWNWARD A FEW
DEGREES TO ACCOUNT FOR SLIGHTLY FASTER PROGRESSION. WINDS WILL TURN
TO THE NORTH AT LBT BY 10PM...WILMINGTON AROUND MIDNIGHT...AND
GEORGETOWN BY MORNING. VERY LITTLE DRYING BEHIND THE FRONT DUE TO
MOISTURE BECOMING TRAPPED BENEATH THE FRONTAL INVERSION...SO VERY
LIGHT RAIN SHOWERS AND DRIZZLE WILL PERSIST THROUGH MORNING. MINS
TONIGHT WILL RANGE FROM THE LOWER 40S ACROSS THE EXTREME NORTH...TO
AROUND 50 IN THE FAR SOUTH.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 PM SATURDAY...COOL...CLOUDY AND MOIST DAY IN STORE FOR
SUNDAY AS A SHORT-LIVED COLD AIR DAMMING SITUATION SETS UP. STEADY
NE FLOW AT THE SURFACE AND EXTENSIVE CLOUD COVER WILL KEEP
AFTERNOON TEMPERATURES A DEGREE OR SO EITHER SIDE OF 50 MOST
LOCATIONS. AS IS TYPICAL FOR THIS TYPE OF PATTERN...EXPECT PATCHY
DRIZZLE OR LIGHT RAIN TO MAKE APPEARANCES AT TIMES...WITH MINIMAL
QPF DUE TO WEAK FORCING AND SHALLOW NATURE OF MOISTURE. THERE WILL
BE A LIMITED DIURNAL RANGE OF TEMPERATURES...WITH LOWS MAINLY IN
THE 40S OVERNIGHT.
WEDGE PATTERN WILL ERODE EARLY ON MONDAY AS A COLD FRONT AND
ASSOCIATED UPPER TROUGH APPROACH FROM THE WEST. FLOW WILL TURN TO
THE SOUTH AND THEN SW MONDAY AFTERNOON...ALLOWING FOR A BIG WARM
UP FROM THE PREVIOUS DAY. EXPECT HIGHS IN THE UPPER 60S TO AROUND
70...ABOUT 20 DEGREES HIGHER THAN ON SUNDAY. FRONT WILL MOVE
ACROSS THE EASTERN CAROLINAS MONDAY EVENING AND OVERNIGHT AND WILL
BE OFFSHORE BY AROUND DAYBREAK ON TUESDAY. MOISTURE WILL BE
LIMITED WITH THIS SYSTEM AND BEST UPPER SUPPORT WILL PASS WELL TO
THE NORTH...SO EXPECT ONLY ISOLATED TO SCATTERED CONVECTION TO
ACCOMPANY FROPA. NOT MUCH IN THE WAY OF COLD ADVECTION WITH THIS
FRONT...SO EXPECT LOWS WILL RANGE FROM THE MID 40S INLAND TO
AROUND 50 AT THE COAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 2:30 PM SATURDAY...MAIN FEATURE FOR THE EXTENDED CONTINUES
TO BE THE CUTOFF MEANDERING ABOUT THE SOUTHWEST AND WHEN IT GETS
KICKED OUT. THE LATEST OPERATIONAL RUN OF THE GFS HAS TRENDED MUCH
SLOWER WHILE PREVIOUS RUNS MAINTAINED MORE OF A ZONAL FLOW. HPC
CONTINUES TO FAVOR THE ECMWF SUITE OF PRODUCTS BASED ON MORE
CONSISTENCY. THESE ARE A BIT SLOWER WITH THE SYSTEM BUT OVERALL
ARE SIMILAR TO THIS TIME YESTERDAY. THE ONLY FORECAST CHANGES WITH
THIS PACKAGE WERE TO DELAY THE POPS SLIGHTLY MAINTAINING THE SAME
STRATEGY AS YESTERDAY WITH INCREASING VALUES FROM LATE THURSDAY
THROUGH THE NEW DAY SATURDAY. ONLY MINOR TWEAKS TO TEMPERATURES
WITH A SLIGHT INCREASE ACROSS THE BOARD TO MATCH HPC NUMBERS AND
ADJACENT OFFICES.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...BACK END OF THE PRECIP IS PROGRESSING A BIT FASTER TO
THE EAST THAN PREVIOUSLY THOUGHT. LOOK FOR MOST OF THE PRECIP TO
EXIT THE COAST BY 02Z...WITH A WIND SHIFT TO THE NORTH SHORTLY
AFTER. FAIRLY HIGH CONFIDENCE FOR POST FRONTAL STRATUS TO SETTLE IN
AT ALL TERMINALS BY 04-05Z...CONTINUING FOR MOST OF THE FORECAST
PERIOD. THERE IS A SLIGHT CHANCE THAT THERE WILL BE ENOUGH MIXING TO
SCATTER OUT THE IFR BY SUNDAY AFTERNOON...BUT IT SHOULD BE BRIEF.
WINDS WILL CONTINUE TO VEER TO THE NORTHEAST BY SUNDAY
MORNING...GUSTY AT TIMES...BUT FAIRLY STEADY FOR MOST GIVEN THE POST
WEDGE SITUATION.
EXTENDED OUTLOOK...IFR WILL PERSIST THROUGH MONDAY MORNING.
ANTICIPATE VFR TO DEVELOP MONDAY LATE WITH A SLIGHT CHANCE OF
SHOWERS. VFR TUESDAY. LOW CONFIDENCE FOR MORNING FOG WEDNESDAY AND
THURSDAY MORNINGS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM SATURDAY...SMALL CRAFT ADVISORY HAS BEEN LOWERED TO
SMALL CRAFT EXERCISE CAUTION WHICH WILL LAST THROUGH 3 AM.
SW WINDS HAVING BASICALLY PEAKED AND WILL BEGIN TO VEER TO THE NW AT
THE APPROACH OF THE COLD FRONT...THEN VEER TO THE N-NE AFTER THE
CFP. WILL HOLD SPEEDS IN THE 15-20 KT. DURING THE TRANSITION OR
VEERING PHASE ALONG THE COLD FRONT...SPEEDS COULD DROP TO 10-15 KT.
THREE TO 5 FT WIND DRIVEN WAVES WILL DOMINATE THE SIGNIFICANT SEAS
ACROSS THE COASTAL WATERS...WITH PERIODS AVERAGING 5 TO 7 SECONDS.
CAN NOT RULE OUT AN ISOLATED 6 FOOTER ACROSS THE OUTER WATERS
VICINITY OF FRYING PAN SHOALS BUT NOT ENOUGH TO PLACE 6 FOOTERS IN
SIG SEAS. SEAS WILL BE ADVERTIZED IN THE 4-5 FT RANGE BETWEEN CAPE
FEAR AND LITTLE RIVER DUE TO THE LONGER SW-W FETCH COMPARED TO THE
OTHER MARINE ZONES.
PREVIOUS DISCUSSION................................................
AS OF 300 PM SATURDAY...WINDS AND SEAS ARE FINALLY INCREASING SO
SMALL CRAFT ADVISORY WILL CONTINUE THROUGH TONIGHT. SEAS HAVE ONLY
REACHED 6 FT AT FRYING PAN SHOALS SO FAR TODAY...MOSTLY BECAUSE THE
COLD SHELF WATERS HAVE INHIBITED THE STRONGEST WINDS FROM MIXING
DOWN TO THE SURFACE. WINDS HAVE BUMPED TO 20 KTS AT 41110 LAST HOUR
WITH SEAS APPROACHING 5 FT. SWAN AND WNAWAVE BOTH STILL EXPECTING
5-7 FT SEAS ACROSS AMZ250 AND AMZ252...WITH 4-6 FT IN THE SOUTHERN
WATERS. WITH WIND INCREASE...FEEL THIS IS PRUDENT...AND WILL KEEP
SCA AS IS. SMALL CRAFT CONDITIONS WILL IMPROVE RATHER QUICKLY
TONIGHT...BECOMING ONLY AROUND 10 KTS AND VEERING TO THE NORTH THEN
NORTHEAST BY SUNDAY MORNING. CONSEQUENTLY...SEAS FALL TO 3-4
FT...WITH A CONFUSED WAVE SPECTRUM DUE TO CHANGING WINDS.
SCATTERED SHOWERS AND THUNDERSTORMS WILL CROSS THE WATERS LATE
TONIGHT CREATING LOCALLY HIGHER WINDS AND SEAS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 PM SATURDAY...NELY FLOW OVER THE WATERS ON SUNDAY WILL
TURN SWLY ON MONDAY AS A COLD FRONT APPROACHES FROM THE WEST.
WINDS WILL RANGE FROM 15 TO 20 KTS EARLY ON SUNDAY BEFORE BECOMING
LIGHT AND VEERING TO THE SE OVERNIGHT WITH THE APPROACH OF THE
COLD FRONT. WINDS WILL PICK UP AGAIN MONDAY AFTERNOON BACK IN THE
15 TO 20 KT RANGE FROM THE SW. COLD FRONT MAY MOVE OFFSHORE BY
AROUND DAYBREAK ON TUESDAY. SEAS WILL RANGE FROM 3 TO 5 FT FOR
MUCH OF THE PERIOD.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 2:30 PM SATURDAY...WESTERLY FLOW INITIALLY IN THE WAKE OF THE
COLD FRONT. A SECONDARY PUSH OCCURS LATE TUESDAY INTO WEDNESDAY
WHICH WILL TURN WINDS TO THE NORTHEAST. FINALLY RETURN FLOW SETS UP
THURSDAY AS A SYSTEM TAKES SHAPE WELL TO THE SOUTHWEST. OVERALL WIND
SPEEDS SHOULD REMAIN MODEST WITH THE POSSIBLE EXCEPTION OF LATE INT
HE PERIOD WHEN THE SOUTHWEST FLOW SURGES. SEAS WILL REFLECT THE
MODEST WINDS WITH AROUND TWO FEET FOR TUESDAY AND WEDNESDAY
INCREASING SLIGHTLY THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/JDW
SHORT TERM...REK
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
605 PM EST SAT JAN 21 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TODAY AND WILL MOVE
ACROSS THE COASTAL CAROLINAS LATE TONIGHT. COOL AND MOIST
CONDITIONS WILL PREVAIL ON SUNDAY AS HIGH PRESSURE BUILDS FROM THE
NORTH. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE REGION MONDAY
NIGHT. HIGH PRESSURE WILL FOLLOW TUESDAY INTO MID WEEK...WITH
ANOTHER FRONTAL SYSTEM APPROACHING FROM THE WEST LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SATURDAY...POTENT SHORTWAVE CLEARLY EVIDENT ON WV
IMAGERY PUSHING ACROSS NORTH GEORGIA ATTM WILL PIVOT THROUGH THE
AREA TONIGHT. ADDITIONALLY...COLD FRONT MOVING EAST THROUGH UPSTATE
SC WILL BECOME MORE E-W ORIENTED AND DROP SOUTHWARD OVERNIGHT. THESE
TWO WILL WORK TOGETHER TO CONTINUE THUNDERSTORMS THROUGH TONIGHT.
LATEST REGIONAL MOSAIC SHOWS A LINE OF STRONGER THUNDERSTORMS FROM
APPROXIMATELY COLUMBIA, SC SOUTHWEST TO MACON, GA. THE STRONGEST
STORMS ARE COLLOCATED WITH ENHANCED LIFT FROM THE PUNCH OF THE S/W
TROUGH...AND EXPECT THE DEEPEST CONVECTION WILL PERSIST IN THIS
MANNER. ALTHOUGH THE SHORTWAVE IS PROGGED TO WEAKEN AS IT MOVES
NORTHEAST TONIGHT...IT APPEARS TO BE SLIGHTLY STRONGER THAN GUIDANCE
HAD SUGGESTED WHICH MAY PERMIT CONVECTION TO CONTINUE LONGER. LATEST
RUC AND HRRR ENSEMBLE REFLECTIVITY HAVE A GOOD HANDLE ON ONGOING
SITUATION...SO HAVE USED A BLEND OF THESE FOR TIMING OF CONVECTION.
VERY LITTLE INSTABILITY...LI`S GREATER THAN 0...AND WINDS ON THE LTX
VWP OF ONLY 30 KTS AT 2 KFT ALL PROMOTE THE CONTINUED IDEA OF ONLY
LIMITED SEVERE POTENTIAL DURING THE NEXT SEVERAL HOURS...EVEN THOUGH
THE SOUTHERN HALF OF THE CWA REMAINS IN A SLIGHT RISK.
STILL...FORECAST GUIDANCE DEVELOPS SOME 7 C/KM ML LAPSE RATES...LI`S
TO -2...AND 0-6 KM SHEAR SUPPORTIVE OF MULTICELL STRUCTURES. HAVE
KEPT SCT TSTMS IN WX GRIDS WITH CATEGORICAL POP FROM WEST TO EAST
THROUGH 10 PM. CANNOT RULE OUT ONE OR TWO WARNINGS TONIGHT...BUT
EXPECT PRIMARILY SUB-SEVERE WIND AND ISOLATED SMALL HAIL.
FROPA OCCURS OVERNIGHT...AND HAVE ADJUSTED MIN TEMPS DOWNWARD A FEW
DEGREES TO ACCOUNT FOR SLIGHTLY FASTER PROGRESSION. WINDS WILL TURN
TO THE NORTH AT LBT BY 10PM...WILMINGTON AROUND MIDNIGHT...AND
GEORGETOWN BY MORNING. VERY LITTLE DRYING BEHIND THE FRONT DUE TO
MOISTURE BECOMING TRAPPED BENEATH THE FRONTAL INVERSION...SO VERY
LIGHT RAIN SHOWERS AND DRIZZLE WILL PERSIST THROUGH MORNING. MINS
TONIGHT WILL RANGE FROM THE LOWER 40S ACROSS THE EXTREME NORTH...TO
AROUND 50 IN THE FAR SOUTH.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 PM SATURDAY...COOL...CLOUDY AND MOIST DAY IN STORE FOR
SUNDAY AS A SHORT-LIVED COLD AIR DAMMING SITUATION SETS UP. STEADY
NE FLOW AT THE SURFACE AND EXTENSIVE CLOUD COVER WILL KEEP
AFTERNOON TEMPERATURES A DEGREE OR SO EITHER SIDE OF 50 MOST
LOCATIONS. AS IS TYPICAL FOR THIS TYPE OF PATTERN...EXPECT PATCHY
DRIZZLE OR LIGHT RAIN TO MAKE APPEARANCES AT TIMES...WITH MINIMAL
QPF DUE TO WEAK FORCING AND SHALLOW NATURE OF MOISTURE. THERE WILL
BE A LIMITED DIURNAL RANGE OF TEMPERATURES...WITH LOWS MAINLY IN
THE 40S OVERNIGHT.
WEDGE PATTERN WILL ERODE EARLY ON MONDAY AS A COLD FRONT AND
ASSOCIATED UPPER TROUGH APPROACH FROM THE WEST. FLOW WILL TURN TO
THE SOUTH AND THEN SW MONDAY AFTERNOON...ALLOWING FOR A BIG WARM
UP FROM THE PREVIOUS DAY. EXPECT HIGHS IN THE UPPER 60S TO AROUND
70...ABOUT 20 DEGREES HIGHER THAN ON SUNDAY. FRONT WILL MOVE
ACROSS THE EASTERN CAROLINAS MONDAY EVENING AND OVERNIGHT AND WILL
BE OFFSHORE BY AROUND DAYBREAK ON TUESDAY. MOISTURE WILL BE
LIMITED WITH THIS SYSTEM AND BEST UPPER SUPPORT WILL PASS WELL TO
THE NORTH...SO EXPECT ONLY ISOLATED TO SCATTERED CONVECTION TO
ACCOMPANY FROPA. NOT MUCH IN THE WAY OF COLD ADVECTION WITH THIS
FRONT...SO EXPECT LOWS WILL RANGE FROM THE MID 40S INLAND TO
AROUND 50 AT THE COAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 2:30 PM SATURDAY...MAIN FEATURE FOR THE EXTENDED CONTINUES
TO BE THE CUTOFF MEANDERING ABOUT THE SOUTHWEST AND WHEN IT GETS
KICKED OUT. THE LATEST OPERATIONAL RUN OF THE GFS HAS TRENDED MUCH
SLOWER WHILE PREVIOUS RUNS MAINTAINED MORE OF A ZONAL FLOW. HPC
CONTINUES TO FAVOR THE ECMWF SUITE OF PRODUCTS BASED ON MORE
CONSISTENCY. THESE ARE A BIT SLOWER WITH THE SYSTEM BUT OVERALL
ARE SIMILAR TO THIS TIME YESTERDAY. THE ONLY FORECAST CHANGES WITH
THIS PACKAGE WERE TO DELAY THE POPS SLIGHTLY MAINTAINING THE SAME
STRATEGY AS YESTERDAY WITH INCREASING VALUES FROM LATE THURSDAY
THROUGH THE NEW DAY SATURDAY. ONLY MINOR TWEAKS TO TEMPERATURES
WITH A SLIGHT INCREASE ACROSS THE BOARD TO MATCH HPC NUMBERS AND
ADJACENT OFFICES.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...BACK END OF THE PRECIP IS PROGRESSING A BIT FASTER TO
THE EAST THAN PREVIOUSLY THOUGHT. LOOK FOR MOST OF THE PRECIP TO
EXIT THE COAST BY 02Z...WITH A WIND SHIFT TO THE NORTH SHORTLY
AFTER. FAIRLY HIGH CONFIDENCE FOR POST FRONTAL STRATUS TO SETTLE IN
AT ALL TERMINALS BY 04-05Z...CONTINUING FOR MOST OF THE FORECAST
PERIOD. THERE IS A SLIGHT CHANCE THAT THERE WILL BE ENOUGH MIXING TO
SCATTER OUT THE IFR BY SUNDAY AFTERNOON...BUT IT SHOULD BE BRIEF.
WINDS WILL CONTINUE TO VEER TO THE NORTHEAST BY SUNDAY
MORNING...GUSTY AT TIMES...BUT FAIRLY STEADY FOR MOST GIVEN THE POST
WEDGE SITUATION.
EXTENDED OUTLOOK...IFR WILL PERSIST THROUGH MONDAY MORNING.
ANTICIPATE VFR TO DEVELOP MONDAY LATE WITH A SLIGHT CHANCE OF
SHOWERS. VFR TUESDAY. LOW CONFIDENCE FOR MORNING FOG WEDNESDAY AND
THURSDAY MORNINGS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SATURDAY...WINDS AND SEAS ARE FINALLY INCREASING SO
SMALL CRAFT ADVISORY WILL CONTINUE THROUGH TONIGHT. SEAS HAVE ONLY
REACHED 6 FT AT FRYING PAN SHOALS SO FAR TODAY...MOSTLY BECAUSE THE
COLD SHELF WATERS HAVE INHIBITED THE STRONGEST WINDS FROM MIXING
DOWN TO THE SURFACE. WINDS HAVE BUMPED TO 20 KTS AT 41110 LAST HOUR
WITH SEAS APPROACHING 5 FT. SWAN AND WNAWAVE BOTH STILL EXPECTING
5-7 FT SEAS ACROSS AMZ250 AND AMZ252...WITH 4-6 FT IN THE SOUTHERN
WATERS. WITH WIND INCREASE...FEEL THIS IS PRUDENT...AND WILL KEEP
SCA AS IS. SMALL CRAFT CONDITIONS WILL IMPROVE RATHER QUICKLY
TONIGHT...BECOMING ONLY AROUND 10 KTS AND VEERING TO THE NORTH THEN
NORTHEAST BY SUNDAY MORNING. CONSEQUENTLY...SEAS FALL TO 3-4
FT...WITH A CONFUSED WAVE SPECTRUM DUE TO CHANGING WINDS.
SCATTERED SHOWERS AND THUNDERSTORMS WILL CROSS THE WATERS LATE
TONIGHT CREATING LOCALLY HIGHER WINDS AND SEAS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 PM SATURDAY...NELY FLOW OVER THE WATERS ON SUNDAY WILL
TURN SWLY ON MONDAY AS A COLD FRONT APPROACHES FROM THE WEST.
WINDS WILL RANGE FROM 15 TO 20 KTS EARLY ON SUNDAY BEFORE BECOMING
LIGHT AND VEERING TO THE SE OVERNIGHT WITH THE APPROACH OF THE
COLD FRONT. WINDS WILL PICK UP AGAIN MONDAY AFTERNOON BACK IN THE
15 TO 20 KT RANGE FROM THE SW. COLD FRONT MAY MOVE OFFSHORE BY
AROUND DAYBREAK ON TUESDAY. SEAS WILL RANGE FROM 3 TO 5 FT FOR
MUCH OF THE PERIOD.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 2:30 PM SATURDAY...WESTERLY FLOW INITIALLY IN THE WAKE OF THE
COLD FRONT. A SECONDARY PUSH OCCURS LATE TUESDAY INTO WEDNESDAY
WHICH WILL TURN WINDS TO THE NORTHEAST. FINALLY RETURN FLOW SETS UP
THURSDAY AS A SYSTEM TAKES SHAPE WELL TO THE SOUTHWEST. OVERALL WIND
SPEEDS SHOULD REMAIN MODEST WITH THE POSSIBLE EXCEPTION OF LATE INT
HE PERIOD WHEN THE SOUTHWEST FLOW SURGES. SEAS WILL REFLECT THE
MODEST WINDS WITH AROUND TWO FEET FOR TUESDAY AND WEDNESDAY
INCREASING SLIGHTLY THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
AMZ254- 256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ250-
252.
&&
$$
NEAR TERM...JDW
SHORT TERM...REK
LONG TERM...SHK
AVIATION...43
MARINE...REK/JDW/SHK
AREA FORECAST DISCUSSION
NWS NORMAN OK
528 AM CST FRI JAN 20 2012
.AVIATION...
LOW CLOUDS...WITH CEILING AROUND 400 FT...HAVE MOVED INTO
FAR SOUTHEAST OKLAHOMA THIS MORNING. EXTRAPOLATION MOVES
LOW CLOUDS INTO/NEAR OUN/OKC AROUND 14Z. WILL ADD A MENTION
OF IFR CEILINGS AT OUN/OKC AROUND 800 FEET FOR A FEW HOURS
AFTER 14Z BUT OVERALL CONFIDENCE THAT THIS WILL OCCUR IS NOT
HIGH. FLOW SHOULD LIMIT LOW CLOUD COVER TO EASTERN OKLAHOMA
BY MID TO LATE MORNING. A COLD FRONT AND NORTH WINDS WILL GRADUALLY
MOVE SOUTH TODAY BRINGING NORTH WINDS TO ALL TAF SITES BY 22Z.
&&
.PREV DISCUSSION... /ISSUED 416 AM CST FRI JAN 20 2012/
DISCUSSION...
SKIES ARE GENERALLY CLEAR ACROSS THE FA EARLY THIS MORNING...HOWEVER
LOW CLOUDS AND AREAS OF FOG ARE CLOSE TO FAR SOUTHEAST OKLAHOMA.
THE LATEST RUC SLOWLY ADVECTS HIGHER DEWPOINT AIR INTO BRYAN AND
ATOKA COUNTIES SHORTLY AFTER SUNRISE WHICH MAY RESULT IN SOME FOG
AND OR/VERY LOW CEILINGS. FARTHER NORTH...SEVERAL MODELS INCREASE
9H HUMIDITY INTO CENTRAL AND NORTH CENTRAL OKLAHOMA DURING THE
EARLY TO MID MORNING HOURS. JUST ENOUGH UPGLIDE MAY BE PRESENT FOR
LOW CLOUDS TO FORM MAINLY EAST OF I-35. FLOW SHOULD VEER ENOUGH
AHEAD OF ANOTHER FRONT TO CLEAR CLOUDS (IF ANY) BY LATE MORNING.
HAVE FOLLOWED 6Z NAM12 FOR GUIDANCE ON DAYTIME HIGHS TODAY...WHICH
IS COLDER ACROSS THE NORTH THAN THE 00Z RUN. STILL SHOULD SEE VERY
WARM TEMPS ACROSS SOUTHERN THIRD OF THE AREA...ESPECIALLY TEXAS
COUNTIES. THIS WILL RESULT IN A HIGHER RISK OF WILDFIRES AS
HUMIDITY LEVELS DROP BELOW 20% FOR AWHILE DURING THE AFTERNOON. NORTH
WINDS AND MORE HUMID AIR SHOULD REACH SOUTHWEST OK/WESTERN N
TEXAS BY LATE AFTERNOON HOWEVER.
THE COLD FRONT TODAY SHOULD BE THE LAST ONE THAT WILL TAP INTO MUCH
COLDER AIR ACROSS SOUTHERN CANADA AND THE NORTHERN PLAINS.
SATURDAY WILL BE CHILLY MOST AREAS BUT SOUTH WINDS WILL RETURN
MOST AREAS DURING THE AFTERNOON. WIND SPEEDS WILL INCREASE
OVERNIGHT WHICH WILL HOLD TEMPERATURES UP...AS A STRONG TROUGH
MOVES ACROSS THE CENTRAL AND SOUTHERN ROCKIES. THE EC MODEL IS A
LITTLE SLOWER WITH THE MOVEMENT OF THIS TROUGH WHICH WILL BRING
RATHER GUSTY NORTHWEST WINDS AND MUCH DRIER AIR. ALTHOUGH THE
FORCING WILL BRING RATHER STRONG...LITTLE IF ANY PRECIPITATION IS
EXPECTED. THE MAIN CONCERN WITH THIS SYSTEM WILL BE AN INCREASE
RISK OF WILDFIRES WITH GUSTY WINDS AND RELATIVELY LOW HUMIDITY
(ESPECIALLY WEST).
WIND SPEEDS SHOULD DIMINISH QUICKLY SUNDAY NIGHT AS THE UPPER SYSTEM
MOVES EAST AND SURFACE GRADIENT DECREASES.
WILL KEEP THE CHANCES FOR RAIN NEXT WEEK HIGHEST ON TUESDAY. STILL SOME
UNCERTAINTIES WITH THIS SYSTEM. EC HAS MUCH STRONGER FLOW ON WESTERN
SIDE OF TROUGH AND EVENTUALLY DEVELOPS A CLOSED LOW OVER
SOUTHWEST TEXAS BY WEDNESDAY. GFS MORE PROGRESSIVE AND BALANCED AND
MOVES THIS TROUGH EAST BY MID TO LATE WEDNESDAY. THE GFS SEEMS
MORE REALISTIC BUT SEVERAL ENSEMBLE MEMBERS ARE CLOSE TO 00Z EC
RUN. EVEN IF EC IS CLOSER...MAIN IMPACT WOULD ALSO BE TUESDAY
INTO EARLY WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 22 44 37 / 0 0 0 10
HOBART OK 61 22 45 37 / 0 0 0 0
WICHITA FALLS TX 68 27 50 38 / 0 0 0 0
GAGE OK 49 18 45 39 / 0 0 0 0
PONCA CITY OK 47 17 40 35 / 0 10 0 10
DURANT OK 69 33 51 43 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
416 AM CST FRI JAN 20 2012
.DISCUSSION...
SKIES ARE GENERALLY CLEAR ACROSS THE FA EARLY THIS MORNING...HOWEVER
LOW CLOUDS AND AREAS OF FOG ARE CLOSE TO FAR SOUTHEAST OKLAHOMA.
THE LATEST RUC SLOWLY ADVECTS HIGHER DEWPOINT AIR INTO BRYAN AND
ATOKA COUNTIES SHORTLY AFTER SUNRISE WHICH MAY RESULT IN SOME FOG
AND OR/VERY LOW CEILINGS. FARTHER NORTH...SEVERAL MODELS INCREASE
9H HUMIDITY INTO CENTRAL AND NORTH CENTRAL OKLAHOMA DURING THE
EARLY TO MID MORNING HOURS. JUST ENOUGH UPGLIDE MAY BE PRESENT FOR
LOW CLOUDS TO FORM MAINLY EAST OF I-35. FLOW SHOULD VEER ENOUGH
AHEAD OF ANOTHER FRONT TO CLEAR CLOUDS (IF ANY) BY LATE MORNING.
HAVE FOLLOWED 6Z NAM12 FOR GUIDANCE ON DAYTIME HIGHS TODAY...WHICH
IS COLDER ACROSS THE NORTH THAN THE 00Z RUN. STILL SHOULD SEE VERY
WARM TEMPS ACROSS SOUTHERN THIRD OF THE AREA...ESPECIALLY TEXAS
COUNTIES. THIS WILL RESULT IN A HIGHER RISK OF WILDFIRES AS
HUMIDITY LEVELS DROP BELOW 20% FOR AWHILE DURING THE AFTERNOON. NORTH
WINDS AND MORE HUMID AIR SHOULD REACH SOUTHWEST OK/WESTERN N
TEXAS BY LATE AFTERNOON HOWEVER.
THE COLD FRONT TODAY SHOULD BE THE LAST ONE THAT WILL TAP INTO MUCH
COLDER AIR ACROSS SOUTHERN CANADA AND THE NORTHERN PLAINS.
SATURDAY WILL BE CHILLY MOST AREAS BUT SOUTH WINDS WILL RETURN
MOST AREAS DURING THE AFTERNOON. WIND SPEEDS WILL INCREASE
OVERNIGHT WHICH WILL HOLD TEMPERATURES UP...AS A STRONG TROUGH
MOVES ACROSS THE CENTRAL AND SOUTHERN ROCKIES. THE EC MODEL IS A
LITTLE SLOWER WITH THE MOVEMENT OF THIS TROUGH WHICH WILL BRING
RATHER GUSTY NORTHWEST WINDS AND MUCH DRIER AIR. ALTHOUGH THE
FORCING WILL BRING RATHER STRONG...LITTLE IF ANY PRECIPITATION IS
EXPECTED. THE MAIN CONCERN WITH THIS SYSTEM WILL BE AN INCREASE
RISK OF WILDFIRES WITH GUSTY WINDS AND RELATIVELY LOW HUMIDITY
(ESPECIALLY WEST).
WIND SPEEDS SHOULD DIMINISH QUICKLY SUNDAY NIGHT AS THE UPPER SYSTEM
MOVES EAST AND SURFACE GRADIENT DECREASES.
WILL KEEP THE CHANCES FOR RAIN NEXT WEEK HIGHEST ON TUESDAY. STILL SOME
UNCERTAINTIES WITH THIS SYSTEM. EC HAS MUCH STRONGER FLOW ON WESTERN
SIDE OF TROUGH AND EVENTUALLY DEVELOPS A CLOSED LOW OVER
SOUTHWEST TEXAS BY WEDNESDAY. GFS MORE PROGRESSIVE AND BALANCED AND
MOVES THIS TROUGH EAST BY MID TO LATE WEDNESDAY. THE GFS SEEMS
MORE REALISTIC BUT SEVERAL ENSEMBLE MEMBERS ARE CLOSE TO 00Z EC
RUN. EVEN IF EC IS CLOSER...MAIN IMPACT WOULD ALSO BE TUESDAY
INTO EARLY WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 22 44 37 / 0 0 0 10
HOBART OK 61 22 45 37 / 0 0 0 0
WICHITA FALLS TX 68 27 50 38 / 0 0 0 0
GAGE OK 49 18 45 39 / 0 0 0 0
PONCA CITY OK 47 17 40 35 / 0 10 0 10
DURANT OK 69 33 51 43 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
908 PM CST SAT JAN 21 2012
.UPDATE...
WITH NEW 00Z NAM AND LAST COUPLE RUNS OF THE HRRR POINTING TOWARD
MORE PCPN FOR SOUTHERN COUNTIES...DECIDED TO ADD THEM TO THE
WINTER WEATHER ADVISORY. LOOKS LIKE MORE SNOW VS EARLIER
PREDICTIONS...AND BLOWING SNOW COULD BE AN ISSUE ON SUNDAY. UPDATES
ALREADY ISSUED.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
BLOWING SNOW CONTINUES ACROSS A LARGE PORTION OF THE CWA THIS
AFTERNOON AS GUSTY SOUTH WINDS OF 20 TO 35 MPH ARE BEING OBSERVED.
AREAS OF LIGHT SNOW CONTINUE ACROSS THE EASTERN CWA AS WELL SO
WILL KEEP MENTION OF THESE ELEMENTS IN GRIDS THROUGH LATE
AFTERNOON AND INTO THE EVENING. BREEZY SOUTH WINDS PERSIST OVER
THE EASTERN COUNTIES FOR A GOOD CHUNK OF THE NIGHT SO OPTED TO
KEEP MENTION OF BLOWING SNOW IN THE GRIDS.
FOCUS REMAINS ON THE STORM SYSTEM IMPACTING THE AREA TONIGHT
THROUGH TOMORROW NIGHT. STILL APPEARS THREAT IS THERE FOR FREEZING
RAIN AND SLEET AHEAD OF THE LOW OVERNIGHT...BUT MODELS BACKING OFF
A BIT AND KEEPING THINGS FURTHER NORTH. DO NOT EXPECT MAJOR ICE
ACCUMS BUT ANYWHERE THAT DOES SEE FREEZING RAIN MAY RECEIVE A FEW
HUNDREDTHS ICE ACCUMULATION. MODELS BEGINNING TO LATCH ONTO A
SOLUTION NOW WHICH HIGHLIGHTS THE WRAP AROUND DEFORMATION SNOWFALL
ON SUNDAY. LOOKS LIKE MUCH OF THE AREA WILL RECEIVE ABOUT 2 TO 4
INCHES OF SNOWFALL WITH A FEW HIGHER AMOUNTS POSSIBLE. MODELS
TRYING TO STRENGTHEN THINGS A BIT IN REGARDS TO SNOWFALL TOMORROW.
A DECENT LITTLE SYSTEM SLIDING THROUGH IT APPEARS. NORTHWEST WINDS
WILL BEGIN TO INCREASE SUNDAY MORNING ACROSS WESTERN AND CENTRAL
SOUTH DAKOTA...THEN FINALLY ACROSS THE EASTERN CWA BY SUNDAY
AFTERNOON AND EVENING. THIS WILL CREATE AREAS OF BLOWING SNOW WITH
REDUCED VSBYS. WILL LET THE WINTER WX ADVISORY RIDE AS IS FOR NOW
AND MID SHIFT MAY NEED TO CONSIDER ADDING THE SOUTHWEST CWA.
APPEARS AMOUNTS WILL BE LIGHTER IN THIS AREA THOUGH. WINDS MAY
REACH ADVISORY CRITERIA TOMORROW AFTERNOON ACROSS THE WESTERN CWA
SO ANOTHER THING TO CONSIDER. THE ADVISORY WINDS CAN BE INCLUDED
IN THE CURRENT WSW...BUT IF THE SOUTHWEST CWA IS LEFT OUT OF THE
WSW...ONE MAY CONSIDER THROWING THEM INTO A WIND ADVISORY FOR THE
AFTERNOON TOMORROW AND MENTION BLOWING SNOW ISSUES.
.LONG TERM...TUESDAY THROUGH SATURDAY
THE OPERATIONAL MODELS AND GFS ENSEMBLES SHOW GOOD AGREEMENT
THROUGH THE LONG TERM. AN UPPER LEVEL HIGH PRESSURE AREA WILL BE
SITUATED OFF THE CA COAST WITH FAST WESTERLY FLOW COMING OFF THE
PACIFIC ACROSS THE NORTHWEST AND ACROSS OUR REGION. THIS MEANS WE
WILL HAVE ABOVE TO MUCH ABOVE NORMAL TEMPERATURES AGAIN ACROSS THE
CWA FOR THE LONG TERM. THE ONLY THING THAT WILL AFFECT THE WARM UP
THIS TIME AROUND WILL BE THE EXTENSIVE SNOW COVER IN PLACE ACROSS
THE REGION. THUS...TEMPERATURES MAY NOT BE QUITE AS WARM.
OTHERWISE...IT IS EXPECTED TO BE DRY WITH SEVERAL FAST MOVING
SHORT WAVES MOVING ACROSS THE REGION WITH LITTLE MOISTURE
AVAILABLE.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
AT KABR/KATY A MIX OF IFR/MVFR CIGS WILL OCCUR THROUGH MOST OF THE
NIGHT. VSBYS WILL FAVOR VFR/MVFR THROUGH THE NIGHT. MOST OF THE
PRECIPITATION AT THESE TWO TAF SITES MAY HOLD OFF TILL WELL AFTER
MIDNIGHT.
AT KPIR/KMBG VFR CIGS AND VSBYS SHOULD GRADUALLY LOWER TOWARD
IFR/MVFR LATE THIS EVENING AS PCPN GRADUALLY SPREADS TOWARD THE MO
RVR VALLEY. A MIX OF FREEZING RAIN AND/OR SLEET IS EXPECTED
OVERNIGHT...TURNING TO ALL SNOW ON SUNDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ SUNDAY
NIGHT FOR BROWN-BUFFALO-CAMPBELL-CORSON-DEWEY-EDMUNDS-FAULK-
HAND-HUGHES-HYDE-JONES-LYMAN-MCPHERSON-POTTER-STANLEY-SULLY-
WALWORTH.
WINTER WEATHER ADVISORY FROM 3 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR CLARK-CODINGTON-DAY-DEUEL-GRANT-HAMLIN-MARSHALL-
ROBERTS-SPINK.
MN...WINTER WEATHER ADVISORY FROM 3 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR BIG STONE-TRAVERSE.
&&
$$
UPDATE...TDK
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
736 PM MST SAT JAN 21 2012
.DISCUSSION...CURRENT SURFACE MAP SHOWS ELONGATED AREA OF LOW
PRESSURE ACROSS EASTERN MONTANA INTO NORTHEAST COLORADO. AREA OF
LIGHT RAIN/FREEZING RAIN SPREADING NORTHWARD EAST AND NORTH OF THE
BLACK HILLS. SURFACE TEMPERATURES ACROSS NORTHWEST SOUTH DAKOTA
REMAIN BELOW FREEZING. SEVERAL FORECAST CHALLENGES OVERNIGHT.
00Z KUNR/KBIS SOUNINGS AND 00Z RUC SOUNDINGS SUPPORT MAINLY
FREEZING RAIN THIS EVENING ACROSS NORTHWEST SOUTH DAKOTA. AS
STRONGER LIFT SPREADS ACROSS THIS AREA AROUND 06Z...SUFFICIENT
COOLING IN THE MID LEVELS WILL ALLOW FOR TRANSITION TO SNOW.
PRECIPITATION HAS BEEN A LITTLE SLOWER TO DEVELOP ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA THIS EVENING. 00Z RUC/NAM
SHOW UPPER LEVEL DIVERGENCE INCREASING THROUGH 06Z WITH DECENT JET
COUPLING. 18Z NAM/GFS AND 00Z RUC STILL MAINTAIN HIGHEST SNOW
AMOUNTS ACROSS NORTHEAST WYOMING/NORTHWEST SOUTH DAKOTA. 00Z NAM
COMING IN...AND SHIFTS HIGHER AMOUNTS INTO SOUTHWEST THROUGH
CENTRAL SOUTH DAKOTA. WILL NOT MAKE SIGNIFICANT CHANGES TO SNOW
AMOUNTS AT THIS TIME.
STRONG WINDS STILL ON TRACK FOR LATE TONIGHT AND SUNDAY. 00Z
NAM/00Z RUC STILL SHOWING 40-50KT BOUNDARY LAYER WINDS ACROSS THE
PLAINS OF WESTERN SOUTH DAKOTA. MOMENTUM TRANSFER ON FORECAST
SOUNDNIGS SUGGEST 55KT GUSTS POSSIBLE...ESPECIALLY FOR THE RAPID
CITY AREA.
OVERALL...CURRENT HEADLINES LOOK GOOD. SNOW WILL TAKE A LITTLE BIT
LONGER TO DEVELOP ACROSS THE BLACK HILLS...BUT WILL NOT ADJUST THE
TIMING OF THE WARNING AT THIS TIME.
&&
.AVIATION...00Z TAFS UPDATE
AREA OF -RA/-FZRA LIFTING NORTHWARD INTO NW SD. AS THIS AREA
WIDESPREAD SNOW EXPECTED TONIGHT ACROSS NORTHEAST WYOMING/NORTHERN
BLACK HILLS/NORTHWEST SOUTH DAKOTA. AS A COLD FRONT SWEEPS
THROUGH THE AREA TONIGHT...VERY STRONG NORTHWEST WINDS WILL OCCUR
ON THE PLAINS NORTH AND EAST OF THE BLACK HILLS...WITH 50-55KT
GUSTS LIKELY AT KRAP. COMBINATION OF WIND AND SNOW WILL RESULT IN
WIDESPREAD IFR/LIFR VSBY. CONDITIONS WILL SLOWLY IMPROVE SUNDAY
MORNING.
PREV DISCUSSION... /ISSUED 330 PM MST SAT JAN 21 2012/
DISCUSSION...22Z SURFACE ANALYSIS SHOWS THE WARM FRONT CURRENTLY
EXTENDING FROM SOUTHEASTERN MONTANA TO NORTH OF THE BLACK
HILLS...THEN TOWARD SOUTHEASTERN SOUTH DAKOTA. TEMPERATURES TO THE
NORTH OF THE WARM FRONT ARE STILL IN THE MID 20S...WITH 40S AND
50S SOUTH OF THE FRONT. THE SFC LOW PRESSURE CENTER WILL DROP INTO
SOUTH CENTRAL SOUTH DAKOTA BY 12Z SUNDAY...FOLLOWED BY A COLD
FRONT AND GUSTY WINDS DUE TO THE TIGHT SURFACE PRESSURE GRADIENT.
FOR TONIGHT...A RELATIVELY STRONG UPPER TROUGH WILL CROSS THE AREA
TONIGHT WITH THE 700MB LOW PROGGED TO TRACK FROM JUST NORTH OF THE
BLACK HILLS EASTWARD TONIGHT. ISENTROPIC LIFT AND FRONTOGENESIS
SHOULD PLACE THE BAND OF HEAVIEST SNOW ACROSS CAMPBELL COUNTY IN
NORTHEASTERN WYOMING TO THE NORTHERN BLACK HILLS AND THEN
NORTHEASTWARD ACROSS NORTHWESTERN SOUTH DAKOTA WITH 3-5 INCHES OF
SNOW THROUGH THAT AREA. DUE TO UPSLOPE ENHANCEMENT HAVE PLACED 5 TO
8 INCH SNOW AMOUNTS IN THE FAVORED AREAS OF THE NORTHERN BLACK
HILLS. MODEL SOUNDINGS SHOW A VERY SHALLOW COLD LAYER OVER
NORTHWESTERN SOUTH DAKOTA WHICH WILL LEAD TO THE POSSIBILITY OF
SOME LIGHT FREEZING RAIN THERE TONIGHT. WINDS BEHIND THE COLD
FRONT ARE EXPECTED TO REACH HIGH WIND WARNING CRITERIA IN THE
RAPID CITY AREA AROUND 09Z. AFTER A SLIGHT LULL IN THE MORNING...WINDS
WILL INCREASE TO NEAR WARNING CRITERIA AGAIN ON SUNDAY ACROSS
NORTHWESTERN AND WEST CENTRAL SOUTH DAKOTA AS SUBSIDENCE TAKES
OVER. DUE TO THE STRONG WINDS COMBINED WITH THE EXPECTED SNOWFALL
AND MIXED PRECIP HAVE ISSUED A WINTER STORM WARNING OVER
NORTHWESTERN SOUTH DAKOTA. WINDS WILL BE SOMEWHAT LIGHTER OVER
NORTHEASTERN WYOMING SO A WINTER WEATHER ADVISORY SHOULD SUFFICE
THERE. MESO MODELS SHOW A DOWNSLOPE HOLE IN THE PRECIPITATION OVER
THE RAPID CITY AREA AND THE ADJACENT PLAINS SO HAVE DECIDED TO
ISSUED A HIGH WIND WARNING OVER THOSE AREAS WITH A MENTION OF SOME
SNOW AND BLOWING SNOW.
THE SNOW IS EXPECTED TO TAPER OFF FROM WEST TO EAST ON SUNDAY BUT
THE GUSTY WINDS AND AREAS OF BLOWING SNOW WILL CONTINUE THROUGH THE
DAY SO WILL KEEP THE HIGHLIGHTS GOING THROUGH SUNDAY.
DRY WEATHER ALONG WITH DECREASING WIND AND CLOUDS EXPECTED ON
SUNDAY NIGHT WITH LOWS IN THE TEENS.
AN AREA OF HIGH PRESSURE WILL MOVE EAST OF THE REGION ON MONDAY...
WITH MOSTLY SUNNY SKIES AND HIGHS MOSTLY IN THE 30S. CLOUDS WILL
INCREASE FROM THE WEST LATE IN THE DAY AND INTO MONDAY NIGHT AS A
WEAK DISTURBANCE CROSSES MT AND WY. WILL KEEP SLIGHT CHANCE FOR SNOW
MONDAY NIGHT INTO EARLY TUESDAY FOR NORTHEASTERN WY AND THE BLACK
HILLS.
EXTENDED...MILDER WEATHER WILL CONTINUE ACROSS THE AREA FOR THE
MIDDLE AND LATTER PART OF NEXT WEEK AS WESTERLY FLOW ALOFT REMAINS
OVER THE REGION. TEMPERATURES WILL GENERALLY REMAIN ABOVE AVERAGE
THROUGH THE PERIOD...WITH THE WARMEST DAYS EXPECTED TO BE WEDNESDAY
AND THURSDAY. A SERIES OF WEAK DISTURBANCES WILL PASS THROUGH THE
REGION DURING THIS TIME...BRINGING SOME CLOUDINESS...CHANCES FOR
SHOWERS...AND OCCASIONAL GUSTY WINDS...MAINLY TO WESTERN PORTIONS OF
THE AREA. TIMING OF THESE WAVES IS STILL RATHER UNCERTAIN IN THIS
FLOW...BUT HAVE KEPT SLIGHT CHANCES FOR WEDNESDAY AND THURSDAY INTO
THURSDAY NIGHT FOR NORTHERN AND WESTERN PORTIONS OF THE CWA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM MST SUNDAY FOR BUTTE-CENTRAL
BLACK HILLS-HARDING-NORTHERN BLACK HILLS-NORTHERN FOOT
HILLS-NORTHERN MEADE CO PLAINS-PERKINS-SOUTHERN MEADE CO
PLAINS-STURGIS/PIEDMONT FOOT HILLS.
WIND ADVISORY FROM 1 AM MST /2 AM CST/ TO 6 PM MST /7 PM CST/
SUNDAY FOR BENNETT-MELLETTE-TODD-TRIPP.
WINTER WEATHER ADVISORY FROM 1 AM TO 6 PM MST SUNDAY FOR HAAKON-
JACKSON-SHANNON.
HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO 6 PM MST SUNDAY FOR
CUSTER CO PLAINS-HERMOSA FOOT HILLS-PENNINGTON CO PLAINS-
RAPID CITY.
WINTER WEATHER ADVISORY UNTIL 6 PM MST SUNDAY FOR ZIEBACH.
WY...WINTER STORM WARNING UNTIL 6 PM MST SUNDAY FOR NORTHEASTERN
CROOK-WYOMING BLACK HILLS.
WINTER WEATHER ADVISORY UNTIL NOON MST SUNDAY FOR NORTHERN
CAMPBELL-SOUTHERN CAMPBELL-WESTERN CROOK-WESTON.
&&
$$
SHORT TERM...07
LONG TERM....WFO UNR
AVIATION...07
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
301 AM MST FRI JAN 20 2012
.DISCUSSION...09Z SURFACE ANALYSIS HAD SHARP ARCTIC BOUNDARY FROM
WEST CENTRAL MT INTO EAST CENTRAL WY INTO SOUTHWEST NE.
TEMPERATURE CONTRAST ACROSS THE FRONT STUNNING...AND VERY SHALLOW
EVIDENCED BY READINGS IN THE LOWER TO MID 30S IN THE BLACK HILLS
AND READINGS AROUND ZERO ON THE ADJACENT PLAINS. WATER VAPOUR
SHOWED SHORTWAVE ENERGY MOVING INTO EASTERN MT WITH ISENTROPIC
LIFT AHEAD OF WAVE PRODUCING A BAND OF -SN FROM CENTRAL MT INTO
EASTERN SD. 00Z NAM/06Z RUC IN GOOD AGREEMENT WITH RADAR
RETURNS/FORECAST...WHICH MEANS -SN WILL END THIS MORNING IN
NORTHWEST SD WITH MINOR ACCUMULATIONS. HIGHS TRICKY TODAY AGAIN
WITH STRONG CONTRAST ACROSS CWA.
TONIGHT...UPPER RIDGE BUILDS TOWARD THE NORTHERN PLAINS WITH
ARCTIC BOUNDARY MORPHING INTO A STRONG WARM FRONT...MAKING IT
THROUGH HALF THE CWA BY MORNING WITH NON-DIURNAL TEMPERATURES
WHERE ARCTIC AIR IS IN PLACE TODAY.
SATURDAY...RIDGE SHIFTS EAST AS UPPER LEVEL TROUGH MOVES INTO THE
ROCKIES. GRADIENT TIGHTENS AS LEE TROUGH/LOW DEVELOPS. 50KT 850MB
WINDS EXPECTED OVER EASTERN PORTIONS OF THE CWA. AMOUNT OF MIXING
BIG QUESTION THOUGH...AS 1KM VISIBLE SATELLITE IMAGERY FROM
THURSDAY SHOWED SNOW COVER OVER THESE AREAS. WILL SPLIT THE
DIFFERENCE AND GO WITH 20-30G40 FOR SOUTHERLY WINDS. WINDS WON/T
BE AS STRONG IN THE WEST. TEMPERATURES WILL BE DRAMATICALLY
WARMER. LIFT AHEAD OF TROUGH MAY PRODUCE SOME -SNRA IN THE FAR
WEST.
SATURDAY NIGHT...MODEST QG-FORCING WILL COMBINE WITH PACIFIC
MOISTURE TO BRING A NICE BAND OF -RASN THROUGH THE CWA. HAVE
INCREASED POPS TO LIKELY. ACCUMULATIONS LOOKED TO BE MINOR GIVEN
RAIN/SNOW MIX.
SUNDAY...COLD FRONT MOVES THROUGH AS SURFACE LOW SHIFTS EAST OF
THE AREA. STRONG GRADIENT EXPECTED WITH GUSTY NORTHWEST WINDS.
TEMPERATURES WILL BE SOMEWHAT COOLER THAN SATURDAY.
EXTENDED...AN UPPER TROUGH WILL CROSS THE WESTERN CONUS
MONDAY...BRINGING CHANCES FOR PRECIP MONDAY NIGHT. NOT MUCH MOISTURE
WILL BE ASSOCIATED WITH THIS SYSTEM...SO QPF IS EXPECTED TO REMAIN
LIGHT. DRIER WEATHER IS EXPECTED TUESDAY AS UPPER RIDGING BUILDS
BEHIND THE DEPARTING TROUGH. A FAST MOVING WAVE IS PROGGED TO CROSS
THE AREA WEDNESDAY BRINGING A RETURN OF LIGHT PRECIP. A SERIES OF
WAVES MAY BRING ADDITIONAL CHANCES FOR LIGHT PRECIP FOR THE SECOND
HALF OF THE WEEK...BUT AT THIS TIME THERE REMAINS MUCH UNCERTAINTY.
TEMPERATURES ARE EXPECTED TO REMAIN NEAR TO SLIGHTLY ABOVE AVERAGE
THROUGH MOST OF THE EXTENDED PERIOD.
&&
.AVIATION...12Z TAFS
LIGHT SNOW WILL CONTINUE THIS MORNING PRIMARILY ACROSS NORTHWEST
INTO CENTRAL SOUTH DAKOTA...RESULTING IN IFR CONDITIONS. CIGS AND
VSBY WILL IMPROVE TO VFR HEADING INTO THE AFTERNOON AS PRECIP SHIFTS
EASTWARD. VFR CONDITIONS ARE THEN EXPECTED TO REMAIN THROUGH FRIDAY
NIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...HELGESON
LONG TERM....CALDERON
AVIATION...CALDERON
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1229 PM CST FRI JAN 20 2012
.DISCUSSION...SYNOPTIC UPDATE AND AVIATION DISCUSSION BELOW.
.UPDATE...FOG AND HAZE PERSIST EARLY THIS AFTERNOON ACROSS LA
SALLE AND WEBB COUNTIES. SURFACE BOUNDARY EXPECTED TO DRIFT
EASTWARD THIS AFTERNOON AND CROSS RIO GRANDE RESULTING IN CLEARING
SKIES AND QUICKLY WARMING TEMPS. HAVE LOWERED FORECAST HIGHS FOR
WESTERN ZONES DUE TO DELAYED WARMING TODAY. HAVE ALSO LOWERED
WINDS ACROSS WESTERN HALF OF CWA AND INCREASED WINDS ACROSS
COASTAL LOCATIONS. STRONG LOW LEVEL JET OF 35 TO 40 KTS AT H925
EXISTS FROM KBRO NORTHEASTWARD TO KPKV AND SOME OF THESE HIGHER
WINDS ARE MIXING TO THE SURFACE. EXPECTING WINDS TO DECREASE BY
LATE AFTERNOON ACROSS EASTERN AREAS AS JET PULLS EASTWARD. UPDATED
PRODUCTS ALREADY OUT.
&&
.AVIATION...MIX OF MVFR/VFR CONDITIONS THIS AFTERNOON ALL
TERMINALS THEN BECOMING IFR/LIFR LATER TONIGHT...THEN BACK TO MVFR
BY LATE IN THE TAF FCST PERIOD. LOW STRATUS WITH IFR CIGS AT KLRD
EARLY THIS AFTERNOON SHOULD MIX OUT WITH SCT TO BKN CU TO EXIST AT
REMAINING TERMINALS. TONIGHT TO FEATURE LOW STRATUS AND FOG/BR
DEVELOPING...ESPECIALLY AFTER 06Z WITH IFR/LIFR CIGS/VSBYS
OCCURRING. WEAK FRONTAL BOUNDARY TO DRIFT SWRD THROUGH REGION
AROUND/SHORTLY AFTER 12Z SATURDAY WITH INCREASING VSBYS AND MVFR
CIGS AFTER FROPA. LIGHT AND VARIABLE WINDS THIS AFTN AT KLRD AND
SSW AND GUSTY ELSEWHERE. TONIGHT WINDS SHOULD BECOME LIGHT AND
THEN NRLY AFTER FROPA SAT MRNG.
&&
.PREV DISCUSSION... /ISSUED 1021 AM CST FRI JAN 20 2012/
DISCUSSION...DENSE FOG ADVISORY HAS BEEN EXTENDED/EXPANDED FOR
WESTERN TWO COUNTIES UNTIL 11AM CST. MOISTURE HAS POOLED THIS
MORNING ALONG HIGHER TERRAIN OF OLD MEX AND ALONG A BOUNDARY
LOCATED JUST WEST OF THE RIO GRANDE. RESULTANT FOG HAS DEVELOPED
DUE TO HIGH MOISTURE AND LIGHT WINDS. RUC AND NAM BOTH INDICATE
BOUNDARY SHOULD BEGIN TO MOVE EASTWARD SHORTLY ACTING AS A QUASI-
DRYLINE THIS AFTERNOON WITH FOG QUICKLY MIXING OUT BETWEEN 17 AND
18Z. AREA OBS AND WEBCAMS INDICATE FOG MAY BE BEGINNING TO MIX OUT
AS OF WRITING AND WILL CONTINUE TO MONITOR TRENDS. OTHER UPDATES
TO FORECAST THIS MORNING HAVE BEEN TO INCREASE DEWPOINT VALUES FOR
TODAY AND TO ALTER SKY COVER. MAX TEMPS ACROSS WESTERN AREAS WILL
BE DEPENDENT ON HOW FAR EAST SAID BOUNDARY MOVES THIS AFTERNOON
BUT FOR NOW HAVE LEFT FORECAST VALUES INTACT. ADDITIONAL UPDATES
POSSIBLE AROUND MIDDAY. UPDATED PRODUCTS ALREADY SENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 82 64 78 62 79 / 10 10 10 10 10
VICTORIA 78 62 74 58 77 / 10 10 10 10 10
LAREDO 85 62 83 63 84 / 0 0 10 10 10
ALICE 85 63 81 61 82 / 10 0 10 10 10
ROCKPORT 74 64 72 62 73 / 10 10 10 10 10
COTULLA 80 55 81 57 81 / 0 0 10 10 10
KINGSVILLE 84 63 79 63 82 / 10 10 10 10 10
NAVY CORPUS 75 64 73 64 74 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
UPDATE/AVIATION...HART/79
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1021 AM CST FRI JAN 20 2012
.DISCUSSION...DENSE FOG ADVISORY HAS BEEN EXTENDED/EXPANDED FOR
WESTERN TWO COUNTIES UNTIL 11AM CST. MOISTURE HAS POOLED THIS
MORNING ALONG HIGHER TERRAIN OF OLD MEX AND ALONG A BOUNDARY
LOCATED JUST WEST OF THE RIO GRANDE. RESULTANT FOG HAS DEVELOPED
DUE TO HIGH MOISTURE AND LIGHT WINDS. RUC AND NAM BOTH INDICATE
BOUNDARY SHOULD BEGIN TO MOVE EASTWARD SHORTLY ACTING AS A QUASI-
DRYLINE THIS AFTERNOON WITH FOG QUICKLY MIXING OUT BETWEEN 17 AND
18Z. AREA OBS AND WEBCAMS INDICATE FOG MAY BE BEGINNING TO MIX OUT
AS OF WRITING AND WILL CONTINUE TO MONITOR TRENDS. OTHER UPDATES
TO FORECAST THIS MORNING HAVE BEEN TO INCREASE DEWPOINT VALUES FOR
TODAY AND TO ALTER SKY COVER. MAX TEMPS ACROSS WESTERN AREAS WILL
BE DEPENDENT ON HOW FAR EAST SAID BOUNDARY MOVES THIS AFTERNOON
BUT FOR NOW HAVE LEFT FORECAST VALUES INTACT. ADDITIONAL UPDATES
POSSIBLE AROUND MIDDAY. UPDATED PRODUCTS ALREADY SENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 82 64 78 62 79 / 10 10 10 10 10
VICTORIA 78 62 74 58 77 / 10 10 10 10 10
LAREDO 87 62 83 63 84 / 0 0 10 10 10
ALICE 85 63 81 61 82 / 10 0 10 10 10
ROCKPORT 74 64 72 62 73 / 10 10 10 10 10
COTULLA 85 55 81 57 81 / 0 0 10 10 10
KINGSVILLE 84 63 79 63 82 / 10 10 10 10 10
NAVY CORPUS 75 64 73 64 74 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 11 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: LA SALLE...WEBB.
GM...NONE.
&&
$$
UPDATE...HART/79
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
926 PM CST SAT JAN 21 2012
.SHORT TERM...UDPATE FOR OVERNIGHT INTO TOMORROW
926 PM CST SAT JAN 21 2012
THE MAIN FOCUS CONTINUES TO BE ON THE FREEZING DRIZZLE THAT LOOKS
PROBABLE VERY LATE TONIGHT INTO TOMORROW AND HOW WIDESPREAD IT
WILL BECOME.
MUCH OF WHAT WAS MENTIONED EARLIER TODAY STILL HOLDS TRUE NOW WITH
THE PAST FEW RUNS OF RUC SOUNDINGS STILL SHOWING SOME FREEZING
DRIZZLE DEVELOPING THROUGH TOMORROW. THE 20.20Z TO 21.01Z RUC
SOUNDINGS SHOW A SATURATED LAYER FROM THE SURFACE UP TO AROUND
900MB TONIGHT THROUGH THE EARLY MORNING HOURS ACROSS MUCH OF THE
REGION WITH A SUBSTANTIAL DRY LAYER LOCATED AT THE TOP OF THIS LOW
LEVEL INVERSION WHICH ENDS AROUND 800MB. OMEGA LOOKS DECENT ENOUGH
IN THE MID LEVELS OVERNIGHT...BUT IT IS JUST WORKING ON DRY AIR AT
THOSE LEVELS. ITS GOING TO TAKE SOME LOW LEVEL FORCING TO START
PRODUCING ANY DRIZZLE AND THAT DOES NOT APPEAR TO COME IN UNTIL
12Z OR SO FROM THE WEST AS THE SURFACE LOW APPROACHES AND
ISENTROPIC LIFT INCREASES ON THE 280K TO 290K SURFACES. ANOTHER
ISSUE IS THAT THESE SOUNDINGS...ALONG WITH THE 22.00Z NAM THAT IS
JUST COMING IN...ALSO SHOW 925MB TEMPERATURES DOWN AROUND -8C TO
-10C ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA THROUGH 18Z
SUNDAY WHICH MAY BE COLD ENOUGH TO PROMOTE ICE DEVELOPMENT.
SO...INSTEAD OF SEEING JUST FREEZING DRIZZLE ACROSS THIS REGION
SUNDAY MORNING...IT COULD BE A MIX OF FREEZING DRIZZLE...SNOW
GRAINS...AND SLEET. 22.00Z MPX SOUNDING BACKS UP THESE -10C LOW
LEVEL TEMPERATURES...BUT CONFIDENCE IS NOT HIGH ENOUGH THAT THESE
WILL STILL BE COLD ENOUGH TO PRODUCE THE ICE/SNOW IN THE MORNING...SO
HAVE LEFT THE FREEZING DRIZZLE AS THE MAIN PRECIPITATION TYPE. DUE
TO THIS UNCERTAINTY...CONFIDENCE IS LOW ENOUGH THAT A FREEZING
RAIN ADVISORY WILL NOT BE ISSUED THIS EVENING FOR SUNDAY.
THE OTHER NEAR TERM CONSIDERATION WITH THE DRIZZLE WAS WITH
WHETHER TO PUSH IT INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA A
LITTLE FASTER OVERNIGHT...MAINLY AROUND 9-12Z FROM FLOYD COUNTY
IOWA NORTH TO DODGE COUNTY MINNESOTA. THIS IS BASED ON THE 21.01Z
RUC SOUNDINGS FROM MCW SHOWING SOME LOW LEVEL OMEGA GETTING IN
DURING THAT TIME FRAME. STILL THINK THAT THE BETTER FORCING WILL
COME IN LATER...SO NO UPDATES WERE MADE IN THIS AREA.
ONE LAST CONSIDERATION WAS WHETHER TO ADD ANY BLOWING SNOW TO THE
FORECAST FOR OVERNIGHT AS WINDS HAVE PICKED UP TO BETWEEN 20-30KTS
ACROSS MUCH OF THE AREA ALONG AND WEST OF THE MISSISSIPPI RIVER.
DESPITE THE POWDERY SNOW THAT FELL YESTERDAY...A FULL DAY OF
COMPACTION AND SUNLIGHT SEEMS TO BE KEEPING MUCH OF THE SNOW IN
PLACE EXCEPT FOR FURTHER WEST ACROSS NORTHWEST IOWA AND SOUTHWEST
MINNESOTA WHERE VISIBILITY IS DOWN BETWEEN 3/4SM AND 2SM. HAVE
MADE SOME CALLS OUT TO SOUTHEAST MINNESOTA AND NORTHEAST IOWA AND
THE COUNTY SHERIFFS ARE REPORTING THAT THEY HAVE NOT HAD ANY
ISSUES WITH BLOWING SNOW...BUT THAT IT IS JUST DRIFTING SNOW
RUNNING OVER THE TOP OF ROADWAYS. THUS...NO BLOWING SNOW WILL BE
ADDED TO THE FORECAST FOR OVERNIGHT.
TEMPERATURES WILL STICK TO RIGHT AROUND 20 DEGREES OVERNIGHT WITH
LOW LEVEL STRATUS FILLING IN FROM THE WEST AND GUSTY SOUTHEAST
WINDS PROMOTING LOW LEVEL MIXING.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
319 PM CST SAT JAN 21 2012
AFTER AN ACTIVE SHORT TERM PERIOD...LONG TERM FORECAST AT LEAST AT
THIS TIME LOOKS FAIRLY BENIGN. IN THE MEAN...ALL MODELS ARE IN
AGREEMENT OF A FAST WEST-NORTHWEST PATTERN FROM THE PACIFIC
NORTHWEST INTO OUR REGION...WHICH MAY BECOME A LITTLE MORE
NORTHWESTERLY ON SATURDAY WITH INDICATIONS OF A SHORTWAVE TROUGH
DIGGING DOWN INTO THE FORECAST AREA. THIS PATTERN WILL SUPPORT A
FLOW OF MILD PACIFIC AIR INTO THE FORECAST AREA...NOTED BY 850MB
TEMPS THAT STRUGGLE TO GET COLDER THAN -6C FOR THE MOST PART UNTIL
SATURDAY. THERE ARE A FEW SHORTWAVE TROUGHS PROGGED TO MOVE THROUGH
THE AREA...ONE TUESDAY NIGHT AND WEDNESDAY...AND ANOTHER ON
THURSDAY. NEITHER OF THESE FEATURES PRODUCE MUCH QPF IN MODEL
OUTPUT...PRIMARILY BECAUSE THEY DO NOT HAVE MUCH MOISTURE TO WORK
WITH. THE SYSTEM IN THE SHORT TERM PERIOD PRETTY MUCH SHUNTS ALL
MOISTURE SOUTH AND EAST OF THE AREA. THEREFORE...ONLY SOME SLIGHT
CHANCES REMAIN FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
PRECIPITATION TYPE MAY HAVE TO BE WATCHED FOR THIS TIME
PERIOD...GIVEN THE MILDER 850MB TEMPS. WOULD NOT BE SURPRISED TO SEE
EITHER MIXES WITH RAIN...OR WORSE A LOSS OF ICE RESULTING IN
RAIN/FREEZING RAIN VERSUS SNOW. KEPT PRECIPITATION TYPES AS SNOW
SINCE BOTH DETAILS ARE VERY UNCERTAIN AT THIS TIME.
FOR MUCH OF THE LONG TERM PERIOD...FOLLOWED A CONSENSUS BLEND OF
GUIDANCE FOR BOTH TEMPERATURES AND PRECIPITATION THROUGHOUT THE
LONG TERM PERIOD.
&&
.AVIATION...TONIGHT AND SUNDAY
553 PM CST SAT JAN 21 2012
TOUGH FORECAST TONIGHT GOING INTO SUNDAY WITH DETERIORATING
CONDITIONS TO OCCUR AT BOTH TAF SITES. MVFR TO IFR CEILINGS HAVE
SET UP ACROSS MUCH OF MINNESOTA AND WESTERN WISCONSIN...THOUGH
SOME DRY AIR HAS WORKED IN ON THE EASTERN EDGE OF THE LOW LEVEL
STRATUS ACROSS ILLINOIS. THERE COULD BE SOME BRIEF JUMPS UP TO
VFR AT LSE WHICH IS CURRENTLY MVFR AND UP TO MVFR AT RST WHICH HAS
GONE BACK AND FORTH BETWEEN IFR AND MVFR. AS THE LOW LEVEL JET
STRENGTHENS THIS EVENING...MORE LOW LEVEL MOISTURE SHOULD ADVECT
INTO THE REGION AND SEND CEILINGS BACK DOWN TO MVFR/IFR OR LOWER
POSSIBLY.
AS THE PRESSURE GRADIENT TIGHTENS UP OVERNIGHT...WINDS WILL PICK
UP OUT OF THE SOUTHEAST WITH SUSTAINED WINDS IN THE 15-18KT RANGE
AT RST WITH SOME GUSTS POSSIBLY IN THE 20 TO 25KT RANGE. THESE
GUSTY WINDS MAY LEAD TO SOME BLOWING SNOW AND ADD SOME VISIBILITY
ISSUES TO THE ALREADY IFR CEILINGS. VISIBILITY HAS DROPPED INTO
THE 1 TO 3SM RANGE ACROSS WESTERN MINNESOTA WHERE THESE WINDS HAVE
ALREADY STRENGTHENED. CONFIDENCE IS NOT HIGH WITH WHETHER THESE
LOWER VISIBILITIES WILL GET INTO RST...BUT IT IS POSSIBLE THIS
EVENING AND OVERNIGHT.
AS CEILINGS CONTINUE TO LOWER THROUGH THE DAY TOMORROW...THERE
WILL BE INCREASING CHANCES FOR PRECIPITATION TO START FALLING AT
THE TAF SITES. BASED ON FORECAST SOUNDINGS FROM THE 21.18Z NAM/GFS
AND 21.22Z RUC...IT APPEARS THAT THE DOMINANT PRECIPITATION TYPE
WILL BE FREEZING DRIZZLE STARTING TOMORROW MORNING...BUT THERE
COULD BE A BRIEF PERIOD WHERE SOME SNOW MIXES IN EARLY ON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
319 PM CST SAT JAN 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
553 PM CST SAT JAN 21 2012
.SHORT TERM...TONIGHT THROUGH MONDAY
319 PM CST SAT JAN 21 2012
MAIN FOCUS IS ON A VARIETY OF PRECIPITATION TYPES FOR LATER TONIGHT
THROUGH MONDAY.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OVER THE WESTERN U.S....RIDGING ACROSS MUCH OF THE
PLAINS...AND TROUGHING OVER SOUTHEAST CANADA. 500MB HEIGHT FALLS IN
12 HOURS ARE AS MUCH AS 170 METERS WITH THE WESTERN TROUGH ACCORDING
TO THE RUC...CENTERED OVER EASTERN NEVADA. THE FORECAST AREA RESIDES
ON THE EAST SIDE OF THE RIDGING...FAVORING HIGH PRESSURE AT THE
SURFACE. THIS HIGH WAS CENTERED OVER LAKE MICHIGAN...AFTER BEING
OVER THE FORECAST AREA EARLY THIS MORNING WHICH ALLOWED FOR THE 10
TO 20 BELOW ZERO READINGS. SOUTHERLY FLOW IS INCREASING ON THE BACK
SIDE OF THE HIGH...ESPECIALLY ACROSS THE PLAINS AHEAD OF A LEE
TROUGH. 850MB PROFILER AND RUC WIND DATA SHOWED SOUTHWEST WINDS OF
35-50 KT FROM KANSAS INTO THE EASTERN DAKOTAS AND WESTERN MINNESOTA.
SOUNDINGS SHOW SOME STRONG WARMING AT 850MB AS A RESULT OF THE
INCREASING WINDS. BETWEEN 00Z AND 12Z...850MB TEMPS ROSE FROM -11C
TO -2C AT OAX...-11C TO +2C AT LBF AND -14C TO +6C AT UNR. THE
SOUTHERLY FLOW IS ALSO ADVECTING STRATUS THAT WAS JUST SOUTH OF THE
FORECAST AREA THIS MORNING BACK TO THE NORTHWEST. THE STRATUS DECK
NOW COVERS MUCH OF IOWA AND THE WESTERN HALF OF MINNESOTA. LAST ITEM
OF NOTE IS A LARGE AREA OF STRATUS ALONG THE GULF COAST...AS WELL AS
HIGHER SURFACE DEWPOINTS. THIS MOISTURE IS IMPORTANT FOR TOMORROW.
MODEL ANALYSIS...MODELS ARE STILL HAVING SOME ISSUES WITH THE
TROUGHING OVER THE WESTERN U.S. AS IT TRACKS INTO THE PLAINS ON
SUNDAY. THE GFS/ECMWF/CANADIAN ARE BY FAR THE DEEPEST... ESPECIALLY
WHEN IT COMES TO THE SHORTWAVE AT THE BASE OF THE TROUGH WHICH
CROSSES THE SOUTHERN PLAINS. THE ECMWF HAS BEEN EXTREMELY CONSISTENT
WITH THE GFS AND CANADIAN TRENDING RAPIDLY TOWARDS THE ECMWF. AS
SUCH...THESE MODELS ALLOW FOR THAT SHORTWAVE TO TURN NEGATIVE TILT
AND LIFT INTO ILLINOIS SUNDAY NIGHT. IMMEDIATELY AHEAD OF THIS
SHORTWAVE THERE IS A DEEPENING SURFACE LOW...WHICH ENDS UP TRACKING
FROM OKLAHOMA ON SUNDAY TO NEAR MILWAUKEE AT 12Z MONDAY. THE 21.12Z
NAM CONTINUES TO SUGGEST A LITTLE MORE PROGRESSIVE TROUGH AND LESS
FOCUS ON THE NEGATIVELY TILT SHORTWAVE...RESULTING IN THE SURFACE
LOW TRACKING FROM SOUTH DAKOTA ON SUNDAY TO THUNDER BAY ONTARIO BY
12Z MONDAY. BASED ON HOW POTENT THE TROUGH LOOKS CROSSING NEVADA
THIS AFTERNOON...NOTED TOO BY THE LIGHTNING ASSOCIATED WITH IT...
THINK THE DEEPER GFS/ECMWF SCENARIOS ARE MORE LIKELY TO OCCUR.
TONIGHT...LOW LEVEL SOUTHERLY FLOW WILL INCREASE TONIGHT AS THE
WESTERN U.S. TROUGH BEGINS TO MOVE INTO THE WESTERN SIDE OF THE
PLAINS. AS THIS SOUTHERLY FLOW INCREASES...THE STRATUS TO OUR SOUTH
AND WEST WILL GRADUALLY OVERSPREAD THE FORECAST AREA...TAKING THE
LONGEST OVER WISCONSIN. IN ADDITION...TEMPERATURES AND DEWPOINTS
SHOULD RISE AS THE WARMER READINGS TO THE SOUTH ADVECT NORTHWARD.
A BIG CONCERN IS SOME OF THE FLURRY ACTIVITY THAT HAS ALREADY
OCCURRED IN THE STRATUS DECK. THERE ARE INDICATIONS THAT THE LIFT
PRODUCING THESE FLURRIES WILL OCCUR AT LEAST OVER NORTHWEST SECTIONS
OF THE FORECAST AREA AFTER MIDNIGHT...AND PERHAPS WESTERN SECTIONS
TOO. HOWEVER...AS THE TEMPERATURES IN THE STRATUS DECK
WARM...WORRIED THAT WE MAY LOSE ICE PRODUCTION...RESULTING IN
FREEZING DRIZZLE. PLACED BOTH A MENTION OF FLURRIES AND PATCHY
FREEZING DRIZZLE AFTER MIDNIGHT OVER NORTHWEST SECTIONS.
SUNDAY...STRONG SOUTHERLY FLOW LOOKS TO CONTINUE WITH THE AREA STILL
AHEAD OF THE UPPER TROUGH MOVING INTO THE PLAINS...AS WELL AS THE
ASSOCIATED SURFACE TROUGH/LOW. THIS SOUTH FLOW SHOULD BRING THE
WARMER AND MORE MOIST AIR ALONG THE GULF COAST NORTHWARD INTO THE
FORECAST AREA. AS A RESULT...THE STRATUS DECK OVER THE FORECAST AREA
SHOULD DEEPEN THROUGH THE DAY. WITH THE STRATUS DECK WARMER THAN
-10C OVER MUCH OF THE AREA THROUGH THE ENTIRE DAY...ENVISIONING ONLY
DRIZZLE. THERE ARE INDICATIONS OF MID AND UPPER LEVEL CLOUDS COMING
ACROSS...WITH LIFT THERE TOO TO PRODUCE ICE...BUT THE DRY LAYER
BETWEEN THESE CLOUDS AND THE LOW STRATUS IS DEEPER AND DRIER THAN
PROGGED TWO DAYS AGO. THEREFORE...ANY ICE PRODUCED ALOFT SHOULD
EVAPORATE BEFORE REACHING THE STRATUS. EVEN IF IT DID REACH THE
STRATUS...THE DRY LAYER HAS TEMPERATURES PROGGED AT 3-6C WHICH WOULD
TEND TO MELT THE ICE. LIFT WITHIN THE STRATUS DECK IS PROGGED TO
INCREASE TOO THROUGH THE DAY...NOTED ON 280-285K SURFACES...WHICH
MAY RESULT IN A CHANGE FROM DRIZZLE TO RAIN. HOWEVER...NONE OF THE
LIFT IS ALL THAT STRONG...SO KEPT THINGS SIMPLE AND STATED DRIZZLE
ALL DAY. QPF/ICE AMOUNTS LIKELY TO BE ONE TO THREE HUNDREDTHS. WHERE
FREEZING DRIZZLE AND DRIZZLE OCCURS WILL BE DICTATED BY SURFACE
TEMPERATURE...TO SOME DEGREE. ONE ISSUE IS THAT WE HAVE HAD A LOT OF
COLD TEMPERATURES RECENTLY...SO EVEN WHERE TEMPERATURES CLIMB ABOVE
FREEZING...UNTREATED SURFACES MAY ICE UP. KEPT PRECIPITATION CHANCES
LOW SINCE THERE STILL IS UNCERTAINTY ON HOW MUCH DRIZZLE WILL FALL.
MOS GUIDANCE QUITE LOW ON NUMBERS...THOUGH 21.15Z SREF DOES INDICATE
60-70 PERCENT OF MEMBERS PRODUCING A 0.01 OR MORE OF QPF. WITH
PRECIPITATION CHANCES RIGHT NOW FORECAST AT BELOW 60 PERCENT...AND
PER COLLABORATION WITH SURROUNDING OFFICES...HELD OFF ON ANY
FREEZING RAIN ADVISORY FOR NOW. DO FEEL THAT AN ADVISORY WILL BE
NEEDED.
SUNDAY NIGHT INTO MONDAY...AS THE LOW DEEPENS AND LIFTS OFF TO THE
NORTHEAST SUNDAY NIGHT...COLDER AIR WILL GRADUALLY FILTER SOUTHEAST
INTO THE FORECAST AREA FROM THE NORTHERN PLAINS. HOW FAST THIS
OCCURS DEPENDS ON THE EXACT TRACK OF THE LOW...WHICH IS STILL FAR
FROM CERTAIN. THEREFORE...POTENTIAL REMAINS FOR DRIZZLE/FREEZING
RAIN UNTIL THE LOW PASSES. EVEN THEN...DEPENDING ON THE LOW
TRACK...THERE COULD STILL BE A WARM LAYER ALOFT THAT HAS TO COOL..
RESULTING IN MIXED PRECIPITATION TYPES. FOR NOW...JUST STUCK WITH A
DRIZZLE/FREEZING DRIZZLE EVENING CHANGING OVER TO RAIN/SNOW AFTER
MIDNIGHT. NEEDLESS TO SAY MORE MODIFICATION WILL BE NEEDED FOR
SUNDAY NIGHT...POSSIBLY INTO EARLY MONDAY AS WELL. SNOW SHOULD
SLOWLY TAPER OFF SOUTHWEST TO NORTHEAST MONDAY AS THE LOW PULLS AWAY
FROM THE AREA. DID RAISE PRECIPITATION CHANCES MONDAY
MORNING...THOUGH...WITH GOOD CONSENSUS OF WRAP AROUND PRECIPITATION
IN THE AREA. SHOULD SEE TEMPERATURES CLIMB SOME SUNDAY NIGHT AS THE
LOW APPROACHES...THEN SLOWLY FALL ON MONDAY AS THE LOW MOVES AWAY.
WINDS SHOULD PICK UP TOO ON MONDAY...ESPECIALLY OVER THE WIND
FAVORED AREAS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA. LOOKS LIKE
WINDS SHOULD STAY WELL BELOW ADVISORY...THOUGH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
319 PM CST SAT JAN 21 2012
AFTER AN ACTIVE SHORT TERM PERIOD...LONG TERM FORECAST AT LEAST AT
THIS TIME LOOKS FAIRLY BENIGN. IN THE MEAN...ALL MODELS ARE IN
AGREEMENT OF A FAST WEST-NORTHWEST PATTERN FROM THE PACIFIC
NORTHWEST INTO OUR REGION...WHICH MAY BECOME A LITTLE MORE
NORTHWESTERLY ON SATURDAY WITH INDICATIONS OF A SHORTWAVE TROUGH
DIGGING DOWN INTO THE FORECAST AREA. THIS PATTERN WILL SUPPORT A
FLOW OF MILD PACIFIC AIR INTO THE FORECAST AREA...NOTED BY 850MB
TEMPS THAT STRUGGLE TO GET COLDER THAN -6C FOR THE MOST PART UNTIL
SATURDAY. THERE ARE A FEW SHORTWAVE TROUGHS PROGGED TO MOVE THROUGH
THE AREA...ONE TUESDAY NIGHT AND WEDNESDAY...AND ANOTHER ON
THURSDAY. NEITHER OF THESE FEATURES PRODUCE MUCH QPF IN MODEL
OUTPUT...PRIMARILY BECAUSE THEY DO NOT HAVE MUCH MOISTURE TO WORK
WITH. THE SYSTEM IN THE SHORT TERM PERIOD PRETTY MUCH SHUNTS ALL
MOISTURE SOUTH AND EAST OF THE AREA. THEREFORE...ONLY SOME SLIGHT
CHANCES REMAIN FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
PRECIPITATION TYPE MAY HAVE TO BE WATCHED FOR THIS TIME
PERIOD...GIVEN THE MILDER 850MB TEMPS. WOULD NOT BE SURPRISED TO SEE
EITHER MIXES WITH RAIN...OR WORSE A LOSS OF ICE RESULTING IN
RAIN/FREEZING RAIN VERSUS SNOW. KEPT PRECIPITATION TYPES AS SNOW
SINCE BOTH DETAILS ARE VERY UNCERTAIN AT THIS TIME.
FOR MUCH OF THE LONG TERM PERIOD...FOLLOWED A CONSENSUS BLEND OF
GUIDANCE FOR BOTH TEMPERATURES AND PRECIPITATION THROUGHOUT THE
LONG TERM PERIOD.
&&
.AVIATION...TONIGHT AND SUNDAY
553 PM CST SAT JAN 21 2012
TOUGH FORECAST TONIGHT GOING INTO SUNDAY WITH DETERIORATING
CONDITIONS TO OCCUR AT BOTH TAF SITES. MVFR TO IFR CEILINGS HAVE
SET UP ACROSS MUCH OF MINNESOTA AND WESTERN WISCONSIN...THOUGH
SOME DRY AIR HAS WORKED IN ON THE EASTERN EDGE OF THE LOW LEVEL
STRATUS ACROSS ILLINOIS. THERE COULD BE SOME BRIEF JUMPS UP TO
VFR AT LSE WHICH IS CURRENTLY MVFR AND UP TO MVFR AT RST WHICH HAS
GONE BACK AND FORTH BETWEEN IFR AND MVFR. AS THE LOW LEVEL JET
STRENGTHENS THIS EVENING...MORE LOW LEVEL MOISTURE SHOULD ADVECT
INTO THE REGION AND SEND CEILINGS BACK DOWN TO MVFR/IFR OR LOWER
POSSIBLY.
AS THE PRESSURE GRADIENT TIGHTENS UP OVERNIGHT...WINDS WILL PICK
UP OUT OF THE SOUTHEAST WITH SUSTAINED WINDS IN THE 15-18KT RANGE
AT RST WITH SOME GUSTS POSSIBLY IN THE 20 TO 25KT RANGE. THESE
GUSTY WINDS MAY LEAD TO SOME BLOWING SNOW AND ADD SOME VISIBILITY
ISSUES TO THE ALREADY IFR CEILINGS. VISIBILITY HAS DROPPED INTO
THE 1 TO 3SM RANGE ACROSS WESTERN MINNESOTA WHERE THESE WINDS HAVE
ALREADY STRENGTHENED. CONFIDENCE IS NOT HIGH WITH WHETHER THESE
LOWER VISIBILITIES WILL GET INTO RST...BUT IT IS POSSIBLE THIS
EVENING AND OVERNIGHT.
AS CEILINGS CONTINUE TO LOWER THROUGH THE DAY TOMORROW...THERE
WILL BE INCREASING CHANCES FOR PRECIPITATION TO START FALLING AT
THE TAF SITES. BASED ON FORECAST SOUNDINGS FROM THE 21.18Z NAM/GFS
AND 21.22Z RUC...IT APPEARS THAT THE DOMINANT PRECIPITATION TYPE
WILL BE FREEZING DRIZZLE STARTING TOMORROW MORNING...BUT THERE
COULD BE A BRIEF PERIOD WHERE SOME SNOW MIXES IN EARLY ON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
319 PM CST SAT JAN 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
254 PM CST FRI JAN 20 2012
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
254 PM CST FRI JAN 20 2012
MAIN FORECAST CONCERNS THIS PACKAGE...SN/FZRA CHANCES SUN...MAINLY
SNOW CHANCES SUN NIGHT/MON...TEMPERATURES THRU THE PERIOD.
18Z DATA ANALYSIS HAD A BROAD AREA OF LIGHT TO MDT SNOW MOVING EAST
ACROSS SOUTHERN MN/WI AND NORTHERN IA INTO NORTHERN IL. SNOW
TAPERING OFF ALONG/WEST OF I-35 EARLY THIS AFTERNOON AS LOWER LEVEL
MOISTURE TRANSPORT/WARM ADVECTION INTO A RATHER TIGHT/COLD THERMAL
ZONE AND DIVERGENCE ALOFT IN RIGHT ENTRANCE REGION OF A 500 AND
300MB JET MAX TRANSLATE EAST OF THE AREA. WV IMAGERY SHOWED THE WEAK
MID LEVEL SHORTWAVE AND TROUGH MOVING ACROSS MN/IA. WITH DEEP CLOUDS
AND LIGHT WINDS...18-19Z TEMPS ACROSS MUCH OF MN/IA/WI REMAINED ON
THE COLD SIDE...MOSTLY IN THE SINGLE DIGITS ABOVE ZERO.
NO LARGE ERRORS NOTED IN 20.12Z MODELS INITIALIZATIONS. SOLUTIONS
REASONABLY SIMILAR THRU 12Z SUN. FOR SUN THRU MON NIGHT MODELS THEN
DIVERGE INTO TWO CAMPS WITH THE HANDLING OF THE NEXT STRONGER SYSTEM
TO IMPACT THE UPPER MIDWEST...THE FASTER NCEP VS. SLOWER/STRONGER
NON-NCEP SOLUTIONS. DPROG/DT OF 500MB HGTS AT 20.12ZS SHOWED MODEL
RUNS OF 18.12Z AND 19.12Z VERIFIED RATHER WELL ACROSS NOAM/EASTERN
PAC...WITH A TREND TOWARD A BLEND OF THE EARLIER RUNS. THRU TONIGHT/
SAT MODELS TREND IS TOWARD STRONGER OF THE EARLIER RUNS WITH THE
NEXT TROUGH DIGGING INTO THE CENTRAL/SOUTHERN ROCKIES. GOOD
CONSISTENCY FOR SHORTWAVE RIDGING TO BUILD ACROSS THE UPPER MIDWEST
TONIGHT/SAT. TREND CONTINUES TO FAVOR STRONGER OF EARLIER SOLUTIONS
SAT NIGHT/SUN AS THE ROCKIES TROUGH EJECTS INTO THE CENTRAL/SOUTHERN
PLAINS. MODELS QUICKLY DIVERGE WITH THE EVOLUTION OF THE TROUGH AS
IT LIFTS ACROSS THE MID/UPPER MS VALLEY SUN NIGHT/MON...WITH NAM/GFS
OFFERING A FASTER/MORE OPEN WAVE SOLUTION AND UKMET/ECMWF/GEM
OFFERING A SLOWER/STRONGER MORE CLOSED 500MB LOW SOLUTION. TREND
SEEMS TO FAVOR THE SLOWER/STRONGER SOLUTIONS SUN NIGHT/MON. THE
BETTER RUN-TO-RUN CONSISTENCY IN THE SUN-MON TIME-FRAME SHOWN BY
ECMWF. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED ALL QUITE GOOD SFC
MASS FIELDS OVER THE CENTRAL CONUS AND WITH THE SNOW MOVING ACROSS
THE REGION TODAY. PER WV IMAGERY...MODEL HAVE THE GENERAL IDEA OF
THE SHORTWAVE TROUGH MOVING ACROSS MN/IA BUT DIFFER ON ACTUAL
SHORTWAVE DETAILS. ALL APPEAR REASONABLE WITH THE NEXT ENERGY
APPROACHING THE WEST COAST. NO CLEAR MODEL FAVORITE BASED ON THE 18Z
ANALYSIS...BUT WITH THE BETTER RUN-TO-RUN CONSISTENCY SHOWN BY THE
ECMWF...FAVORED A MODEL COMPROMISE WEIGHTED TOWARD THE ECMWF
ESPECIALLY IN THE SUN NIGHT/MON TIME-FRAME. SHORT TERM FCST
CONFIDENCE GENERALLY GOOD TONIGHT INTO SUN...THEN AVERAGE SUN
NIGHT INTO MON NIGHT WITH THE MODELS IN TWO CAMPS.
FOR THE SHORT TERM...FORCING/LIFT/SNOW EXITING EAST OF THE AREA
RATHER QUICKLY AT MID AFTERNOON AND WAS ALREADY ENDING WEST OF A
KEAU-KALO LINE AS OF 20Z. WILL CANCEL WESTERN PORTIONS OF THE
WINTER WEATHER ADVISORY WEST/NORTH OF KLSE WITH THE AFTERNOON
PACKAGE ISSUANCE IF NOT BEFORE. BIG QUESTION TONIGHT BECOME CLOUD
COVER NOT AND IMPACTS ON LOW TEMPS. SFC RIDGE AXIS WITH LIGHT/CALM
WINDS OVER THE FRESH SNOW COVER WOULD ALLOW TEMPS TO PLUMMET WELL
BELOW ZERO TONIGHT. IF CLOUD COVER WOULD REMAIN ALL NIGHT...LOWS
WOULD BE MORE IN THE ZERO TO -5F RANGE. LOOKING UPSTREAM...PLENTY OF
LOW TO MID CLOUDS PRESENT...AND PLENTY OF THIN SPOTS/HOLES IN THOSE
CLOUD DECKS. WILL TREND TOWARD THE MIDDLE FOR NOW AND PASS ALONG
CONCERNS TO EVENING CREW TO WATCH THE CLOUD TRENDS AND POTENTIAL
LOWS TONIGHT. SOUTH/SOUTHWEST FLOW AND MDT/STRONG LOW LEVEL WARM
ADVECTION QUICKLY RETURN ON SAT AS THE NEXT LEE TROUGH DEVELOPS IN
THE CENTRAL/NORTHERN PLAINS. 850MB TEMPS CLIMB TO NEAR/ABOVE 0C BY
LATE SAT AND FOR SAT NIGHT AS THE SFC-MID LEVEL TROUGH MOVE EAST.
MID/HIGH LEVEL MOISTURE/INCREASING HIGH CLOUDS AHEAD OF THE TROUGH
SPREAD ACROSS THE AREA FOR SAT AFTERNOON/NIGHT. MODEL SOUNDINGS
INDICATE A STRENGTHENING LOW LEVEL INVERSION NEAR 900MB OVER THE
AREA SAT/SAT NIGHT. THIS WITH THE INCREASING CLOUDS WILL LIMIT THE
WARMUP OVER THE SNOWCOVER SAT. WITH CONTINUED SOUTHERLY FLOW AND
POTENTIAL FOR A LOW CLOUD BLANKET SAT NIGHT...LOWS LIKELY TO BE
EARLY IN THE EVENING WITH STEADY/SLOWLY RISING TEMPS MUCH OF THE
NIGHT. FIRST IMPACTS/PRECIP CHANCES WITH THE NEXT TROUGH ARRIVE SUN.
WITH THE SNOW COVER AND CLOUDS...HAVE DOUBTS ABOUT SUN HIGHS RISING
MUCH ABOVE UPPER 20S/LOW 30S. WITH POTENTIAL FOR 850MB TEMPS TO BE
ABOVE 0C AHEAD OF THE TROUGH ON SUN...AND COLD/FROZEN GROUND
SURFACES...CONTINUED THE -FZRA CHANCE OVER THE SOUTH 3/4 OF THE FCST
AREA. MID LEVEL TROUGH MOVES INTO THE REGION SUN NIGHT WITH THE
COLUMN COOLING TO BELOW 0C. BULK OF ANY PRECIP SUN NIGHT LOOKING TO
BE SNOW BUT CONTINUED A -FZRA CHANCE OVER THE SOUTHEAST END OF THE
FCST AREA WHERE THE COOLING WILL BE LAST TO OCCUR. WITH DIVERGENCE
OF SOLUTIONS...FAST NAM/GFS VS. SLOWER UKMET/GEM/ECMWF...VAST
DIFFERENCES IN POTENTIAL SENSIBLE WEATHER LATER SUN NIGHT INTO MON
NIGHT. WITH TREND FAVORING THE MORE CONSISTENT ECMWF...RAISED PRECIP
CHANCES SUN NIGHT INTO THE 45 TO 65 PERCENT RANGE AND SNOW CHANCES
MON INTO THE 25 TO 45 PERCENT RANGE FOR NOW. IF TREND CONTINUES
STRONGLY TOWARD THE ECMWF CAMP SUN NIGHT/MON...PRECIP CHANCES THESE
PERIODS WILL NEED TO BE TRENDED TO 70 PERCENT OR HIGHER FOR MUCH OF
THE FCST AREA. FOR NOW THE MID-RANGE PROBABILITIES SUN NIGHT/MON
BLEND WELL WITH THE NEIGHBORING GRIDS. TROUGH AXIS LIFTS NORTHEAST
OF THE AREA MON NIGHT WITH SUBSIDENCE/DRYING SPREADING ACROSS MN/IA
AND MUCH OF WI.
FAVORED COLDER OF GUIDANCE LOWS/HIGHS TONIGHT THRU SAT NIGHT.
FAVORED A BLEND OF GUIDANCE HIGHS/LOWS FOR SUN THRU MON NIGHT.
.LONG TERM...TUESDAY THROUGH FRIDAY
254 PM CST FRI JAN 20 2012
20.00Z MEDIUM RANGE MODELS IN REASONABLY GOOD AGREEMENT TUE AS ONE
TROUGH EXITS EAST OF THE REGION AND SHORTWAVE RIDGING ALOFT BUILDS
ACROSS THE UPPER MIDWEST. GFS REMAINS A MORE PROGRESSIVE SOLUTION
BUT ITS 20.06Z RUN TRENDED SLOWER/CLOSER TO THE GEM/UKMET/ECMWF
CONSENSUS. CONSENSUS IMPROVING FOR A MDT MID LEVEL TROUGH TO MOVE
ACROSS THE REGION WED. SOLUTIONS BEGIN TO DIVERGE ON THE DETAILS
THU/FRI BUT SOME CONSENSUS FOR A SECOND NORTHERN STREAM TROUGH
TO PUSH ACROSS THE UPPER MIDWEST THU THEN YET ANOTHER SHORTWAVE
TROUGH TO APPROACH ALONG THE US/CAN BORDER IN QUASI-ZONAL FLOW
FRI. BETTER RUN-TO-RUN CONSISTENCY THRU THE TUE-FRI TO ECMWF. WITH
BETTER CONSISTENCY...GFS TRENDING TOWARD IT AND PMDEPD SIDING TOWARD
THE ECMWF/ENSEMBLE MEAN...ALSO FAVORED A BLEND WEIGHTED TOWARD THE
ECMWF. GIVEN WED-FRI PORTION OF THE FCST DEPENDENT ON PROGRESSIVE
SHORTWAVES IN A RATHER FLAT...FAST FLOW...LONG TERM FCST CONFIDENCE
AVERAGE AT BEST THIS CYCLE. TUE LOOKS DRY/SEASONAL WITH SFC HIGH
PRESSURE RIDGING AND THE SHORTWAVE RIDGING ALOFT OVER THE WESTERN
GREAT LAKES. -SN CHANCE CENTERED ON WED REASONABLE WITH THE BETTER
CONSENSUS FOR A MDT STRENGTH MID LEVEL SHORTWAVE TROUGH TO BE MOVING
ACROSS THE REGION. PLENTY OF MODEL DETAIL DIFFERENCE WITH
STRENGTH/TIMING OF THE NEXT WEAK TO MDT SHORTWAVE IN THE FLOW FOR
THU...GFS FASTER/WEAKER...ECMWF SLOWER/STRONGER. 20.12Z GFS/ECMWF
SUPPORT THEIR RESPECTIVE TRENDS THU. SOME CONSISTENCY FOR A SFC
TROUGH/FRONT TO BE PUSHING ACROSS THE AREA FRI. MODEL CONSENSUS
LEAVES MUCH OF THU/FRI DRY FOR NOW AND THIS REASONABLE PENDING
BETTER/MORE CONSISTENT MODEL SIGNALS IN THE DAY 6/7 TIME-FRAME. WITH
MORE OF A ZONAL FLOW ACROSS THE NORTHERN CONUS NEXT WEEK AND NO
INTRUSIONS OF ARCTIC AIR...TEMPS FOR TUE-FRI LOOKING TO BE
NEAR/ABOVE NORMAL. THIS WELL TRENDED BY THE MODEL CONSENSUS DATA
SETS.
&&
.AVIATION...THROUGH 18Z SATURDAY
1127 AM CST FRI JAN 20 2012
SHORT WAVE TROUGH MOVING OVER THE REGION THIS MORNING WILL BEGIN
TO PASS TO THE EAST DURING THE AFTERNOON AND EVENING. THE 20.12Z
NAM AND SEVERAL RUNS OF THE RUC INDICATE THE FORCING FROM THE SHORT
WAVE TROUGH IS AT IS MAXIMUM NOW AND WILL BE DECREASING FOR THE
REMAINDER OF THE DAY AS THE WAVE BEGINS TO MOVE AWAY. BASED ON RADAR
TRENDS...EXPECT THE VISIBILITY AT KRST TO COME UP TO AROUND A MILE
AND THEN HOLD THERE OR SLOWLY IMPROVE...BUT REMAIN IFR...UNTIL THE
SNOW ENDS LATE THIS AFTERNOON. KLSE WILL SEE THE VISIBILITY REMAIN
UNDER A MILE FOR A COUPLE OF MORE HOURS...BEFORE ALSO IMPROVING TO
AROUND A MILE. THE SNOW AT KLSE IS ALSO EXPECTED TO END VERY LATE
THIS AFTERNOON. CEILINGS EXPECTED TO COME UP TO MVFR AS THE
VISIBILITY GO TO A MILE AND THEN HOLD THERE THROUGH THE EVENING
UNTIL THE SURFACE RIDGE BUILDS IN FROM THE WEST TO SCATTER THE
CLOUDS OUT. ONCE THIS HAPPENS...VFR CONDITIONS THEN EXPECTED THROUGH
SATURDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
254 PM CST FRI JAN 20 2012
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
WIZ042>044-053>055-061.
MN...NONE.
IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
IAZ011-029-030.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1127 AM CST FRI JAN 20 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
300 AM CST FRI JAN 20 2012
ITS GOING TO SNOW ACROSS THE FORECAST AREA TODAY...WITH THE MAIN
QUESTIONS BEING HOW MUCH AND WHERE THE HIGHER TOTALS WILL BE FOUND.
THE UPPER LEVEL SHORTWAVE TROUGH HELPING TO BRING THE SNOW IS NOT
OVERLY APPARENT VIA THE LATEST WATERVAPOR IMAGERY...AND 20.00Z
MODEL RUNS POINT TO A SOMEWHAT WEAK...WEST-EAST ORIENTATED ELONGATED
WAVE MOVING ACROSS THE FORECAST AREA BETWEEN 15-00Z. QG CONVERGENCE
ISN/T ALL THAT IMPRESSIVE...BEST IN THE 850-700 MB LAYER AND ACROSS
IA/NORTHERN ILL. GOOD LOW LEVEL THERMODYNAMICS THOUGH...WITH
ISENTROPIC UPGLIDE ON THE 275-295 K SFC AND WARM AIR ADVECTION IN
THE 925-700 MB LAYER. AGAIN THOUGH...THIS IS STRONGEST ACROSS
IA/NORTHERN ILL. A NORTHEAST-SOUTHWEST RUNNING X-SECTION DOES
INDICATE SLOPING 2-D FRONTOGENETIC LIFT ACROSS THE FORECAST
AREA...STRONGEST THIS MORNING. SOME HINTS OF -EPV ACROSS THE TOP OF
THIS FRONTOGENETIC FORCING ACROSS THE SOUTHERN 1/2 OF THE
AREA...SUGGESTIVE THAT SOME ENHANCED BANDING COULD DEVELOP.
OVERALL...FORCING POINTS TO THE HIGHER ACCUMULATIONS ACROSS
NORTHEAST IA/SOUTHWEST WI TODAY. HOWEVER...A COUPLE QUESTIONS ADD
SOME COMPLEXITY TO THE SNOW POTENTIAL - OVERCOMING THE DRY AIR
ACROSS THE REGION AND WHERE THE DEEPER DENDRITIC GROWTH ZONE WILL
LIE.
20.00Z DVN/MPX SOUNDINGS SHOW A VERY DRY LOW LAYER THAT WILL HAVE TO
BE SATURATED BEFORE ANY SNOW CAN REACH THE GROUND. SECOND...BUFKIT
SOUNDINGS SHOW A VERY DEEP DENDRITIC ZONE GROWTH REGION...UPWARDS OF
15 KFT TO THE SFC...BUT THIS IS SHIFTED NORTH OF THE BETTER
FORCING...MORE AROUND THE I-90 CORRIDOR. 19.21Z SREF HAS THE HIGHEST
PROBABILITIES FOR 2 INCH/HOUR SNOW RATES ALSO IN THIS REGION. SO...A
SLIGHT DISCONNECT BETWEEN WHERE THE BETTER FORCING IS EXPECTED...AND
WHERE THE MORE FAVORABLE HIGH SNOW RATIO REGION WILL BE. AND
AGAIN...SNOW AMOUNTS WILL HAVE TO TAKE INTO CONSIDERATION THE
SATURATION THAT NEEDS TO OCCUR FIRST.
ALL THAT SAID...BELIEVE THE HIGHER TOTALS STILL LOOK GOOD ACROSS
NORTHEAST IA/SOUTHWEST WI. THERE IS A BIT LESS DRY AIR TO OVERCOME
IN THIS REGION AND IT WILL HAVE THE STRONGER FORCING THROUGH THE
DAY. 4 TO 6 INCHES ALSO LOOKS PROBABLE...BUT A FEW 7 INCH
TOTALS WOULD NOT SURPRISE. WILL STAY WITH THE ADVISORY FOR NOW...BUT
TRENDS WILL HAVE TO BE MONITORED. THE BULK OF THE SNOW SHOULD FALL
THIS MORNING.
SUNDAY PRESENTS ANOTHER FORECAST CHALLENGE AS A STRONGER UPPER LEVEL
TROUGH WORKS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY...AND WARMER
AIR BRINGS THE THREAT OF MIXED WINTER PCPN INTO THE PICTURE. THERE
ARE DIFFERENCES WITH HOW THE MODELS HANDLE THIS SYSTEM...AND THEY
WOULD HAVE AN IMPACT ON THE FORECAST AREA. THE 20.00Z NAM AND GFS
ARE MORE PROGRESSIVE/NOT AS STRONG COMPARED TO THE EC/GEM...WITH THE
NAM THE QUICKEST OF THE MODELS. THE STRONGER AND SLOWER EC/GEM
RESULTS IN A DEEPENING SFC LOW CLOSER TO THE FORECAST AREA...AND AN
ENHANCED PCPN REGION AROUND/WEST OF THE LOW. BOTH OF THESE MODELS
HAVE PCPN IMPACTING AT LEAST THE EASTERN 1/2 OF THE FORECAST AREA
THROUGH 12Z MON WHILE THE GFS/NAM HAVE SHIFTED MOST OF THE
PCPN...AND MUCH SMALLER QPF AMOUNTS...EAST. TRENDS HAVE BEEN FARTHER
SOUTH IN THE GFS/EC OVER THE PAST FEW DAYS...THE GEM HAS JUMPED
AROUND A LOT...WHILE THE NAM HAS STAYED NORTH/WEAKER. CONFIDENCE
SHAKY WITH SUCH A VARIETY OF POSSIBILITIES...BUT WILL LEAN ON THE
MORE FAVORED SOUTHERN TRACK. THE EC LOOKS A BIT OVERDONE AND
ALTHOUGH PROBABLY TOO FAST...THE GFS SEEMS LIKE A DECENT COMPROMISE.
WILL LEAN ON A GFS/CONSENSUS SOLUTION IN THIS TIME FRAME FOR NOW.
ON THE FRONT END OF THIS SUNDAY SYSTEM...NORTHEAST-SOUTHWEST RUNNING
X-SECTIONS AND BUFKIT SOUNDINGS SUGGEST THAT THE MOISTURE WILL BE
SHALLOW...AND DEVOID OF ANY ICE. ANY PCPN WOULD BE LIQUID -
POTENTIALLY FREEZING BASED ON SFC TEMPS. HOWEVER...THIS DOESN/T LAST
LONG AS UPWARD SATURATION INTO ICE IS RATHER QUICK. SNOW APPEARS TO
BE THE MOST LIKELY PCPN TYPE WHEN THE BEST FORCING MOVES IN...SUNDAY
NIGHT. COULD STILL SEE A PERIOD OF SOME FREEZING PCPN OVER SOUTHWEST
WI SUN AFTERNOON/EVENING AS SOME LOW LEVEL WARMING COULD RESULT IN
RAIN...BUT HITS COLD GROUNDS FROM THE RECENT COLD SNAP ACROSS THE
REGION. CONFIDENCE IS LOW FOR THE VARIETY OF TYPES WITH THIS
SYSTEM...AND EXPECT REFINEMENT TO THE FORECAST OVER THE NEXT DAY OR
TWO AS MODELS BUILD SOME CONSENSUS.
.LONG TERM...MONDAY THROUGH THURSDAY
300 AM CST FRI JAN 20 2012
ANOTHER SHORTWAVE TROUGH LOOKS TO TRACK EAST ACROSS THE
PLAINS...EVENTUALLY SPINNING ACROSS THE REGION TUE-WED.
DIFFERENCES ON TIMING WITH THIS FEATURE...WITH THE GFS QUICKER THAN
THE EC. QPF IS KIND OF MEAGER VIA BOTH SOLUTIONS...BUT IT DOES LOOK
COLD ENOUGH FOR JUST SNOW. COULD SEE AN INCH OUT OF THIS QUICK
MOVING SHORTWAVE. WILL LEAN ON THE CONSENSUS SOLUTION FOR TIMING.
TEMPERATURES LOOK TO HOLD NEAR OR ABOVE NORMAL FOR MUCH OF THE NEW
WORK WEEK.
&&
.AVIATION...THROUGH 18Z SATURDAY
1127 AM CST FRI JAN 20 2012
SHORT WAVE TROUGH MOVING OVER THE REGION THIS MORNING WILL BEGIN
TO PASS TO THE EAST DURING THE AFTERNOON AND EVENING. THE 20.12Z
NAM AND SEVERAL RUNS OF THE RUC INDICATE THE FORCING FROM THE
SHORT WAVE TROUGH IS AT IS MAXIMUM NOW AND WILL BE DECREASING FOR
THE REMAINDER OF THE DAY AS THE WAVE BEGINS TO MOVE AWAY. BASED ON
RADAR TRENDS...EXPECT THE VISIBILITY AT KRST TO COME UP TO AROUND
A MILE AND THEN HOLD THERE OR SLOWLY IMPROVE...BUT REMAIN
IFR...UNTIL THE SNOW ENDS LATE THIS AFTERNOON. KLSE WILL SEE THE
VISIBILITY REMAIN UNDER A MILE FOR A COUPLE OF MORE HOURS...BEFORE
ALSO IMPROVING TO AROUND A MILE. THE SNOW AT KLSE IS ALSO EXPECTED
TO END VERY LATE THIS AFTERNOON. CEILINGS EXPECTED TO COME UP TO
MVFR AS THE VISIBILITY GO TO A MILE AND THEN HOLD THERE THROUGH
THE EVENING UNTIL THE SURFACE RIDGE BUILDS IN FROM THE WEST TO
SCATTER THE CLOUDS OUT. ONCE THIS HAPPENS...VFR CONDITIONS THEN
EXPECTED THROUGH SATURDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 AM CST FRI JAN 20 2012
WI...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TODAY FOR
WIZ041>044-053>055-061.
MN...WINTER WEATHER ADVISORY TO 6 PM CST TODAY FOR
MNZ086>088-094>096.
IA...WINTER WEATHER ADVISORY TO 6 PM CST TODAY FOR
IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1130 PM CST THU JAN 19 2012
.SHORT TERM...TONIGHT THROUGH TOMORROW
903 PM CST THU JAN 19 2012
MAIN CONCERN CONTINUES TO BE WITH THE SNOW FOR TOMORROW WITH NO
CHANGES PLANNED FOR THE HEADLINES THIS EVENING.
A MID LEVEL SHORTWAVE TROUGH IS MAKING ITS WAY ACROSS ROCKIES WITH
SOME MID TO UPPER LEVEL CLOUD COVER STARTING TO ADVECT INTO THE
REGION ALONG A STRONG UPPER LEVEL JET STREAK OF ABOUT 160KTS AT
250MB BASED ON 20.00Z RAOBS.
AS THIS TROUGH EJECTS OUT OF THE ROCKIES INTO THE PLAINS...SNOW
WILL BEGIN TO FORM OVERNIGHT AND START SPREADING INTO THE
REGION AROUND 3AM OR SO. THE 20.00Z NAM AND 19.21Z SREF HAVE
TRICKLED IN AND ARE STILL PAINTING A SIMILAR PICTURE TO THEIR
PREVIOUS RUNS. THE 19.21Z SREF IS SHOWING SOME HIGHER
PROBABILITIES OF 4 INCHES OR MORE IN A 12 HOUR PERIOD ALONG THE
AXIS OF WHERE THE CURRENT ADVISORY IS LAID OUT WITH 0 PERCENT
PROBABILITIES OF 8 INCHES OR MORE. THE NAM CONTINUES TO BE THE
WORRISOME MODEL WITH HIGHER SNOWFALL TOTALS ALONG A NARROW BAND
ACROSS NORTHEAST IOWA WHERE THE QPF AMOUNTS CAME UP A BIT WITH THE
20.00Z RUN. THE OTHER ISSUE IS WITH THE 750MB WARM LAYER AND HOW
WARM IT WILL BE TOMORROW WHICH WILL DIRECTLY AFFECT HOW DEEP THE
DENDRITIC GROWTH ZONE IS. THE NAM HAS TRENDED TO BE WARMER IN THIS
LAYER WHILE THE GFS HAS BEEN COOLER WITH MUCH OF THE THERMAL
PROFILE FROM THE SURFACE UP TO 550MB IN THE DGZ. THE 19.22Z TO
20.01Z RUC FORECAST SOUNDINGS HAVE NOT HELPED MUCH TO THIS POINT
IN DETERMINING WHICH WAY TO TREND AS EARLIER THEY HAD GONE WITH A
COOLER WARM LAYER...BUT THE LATEST COUPLE OF RUNS HAVE GONE TOWARD
THE NAM THINKING SO PERHAPS THAT IS THE WAY TO TREND.
LONG STORY SHORT...HAVE COLLABORATED WITH NEIGHBORING OFFICES AND
HAVE DECIDED TO HOLD OFF ON ANY UPGRADES OR EXPANSIONS OF THE
CURRENT HEADLINED AREA. THE MAIN CONCERNS WERE WHETHER TO UPGRADE
NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN TO A WINTER STORM
WARNING FOR SOME POSSIBLE BANDING AND HIGHER SNOWFALL
TOTALS IN THE 6 TO 8 INCH RANGE...ALONG WITH PUSHING THE ADVISORY
NORTH A TIER OF COUNTIES FROM WABASHA COUNTY TO JACKSON COUNTY.
WITH MUCH OF THE OTHER 20.00Z GUIDANCE NOT IN YET...HAVE DECIDED
THAT IT WOULD BE MORE PRUDENT TO LET THE MIDNIGHT CREW GET SOME
MORE INFORMATION TO TAKE A BETTER SHOT AT HOW THE SYSTEM LOOKS AS
IT GETS OUT OF THE ROCKIES.
PLEASE SEE THE PREVIOUS AFD FOR COMMENTS ON THE WEATHER BEYOND
TOMORROW.
20.00Z NAM AND 19.21Z SREF GUIDANCE HAS STARTED TRICKLING
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
320 PM CST THU JAN 19 2012
UPPER TROUGH OVER THE PLAINS LOOKS TO LIFT NORTHEAST THROUGH THE
AREA SUNDAY NIGHT AND AWAY FROM THE AREA ON MONDAY. CERTAINLY THIS
BEARS WATCHING FOR TIMING GIVEN THE TREND FOR THIS TROUGH TO BE
AMPLIFIED AND SLOWER. IN FACT THE NEW 19.12Z ECMWF SLOWED DOWN THE
TROUGH A BIT MORE. SHOULD SEE ANY RAIN/FREEZING RAIN CHANGE OVER TO
SNOW THROUGH THE NIGHT SUNDAY NIGHT...WITH ALL SNOW MONDAY...THOUGH
AGAIN THE PRECIPITATION SHOULD BE WINDING DOWN MONDAY. MAY HAVE TO
WATCH FOR POTENTIAL ADVISORY SNOW SUNDAY NIGHT...AND POSSIBLY INTO
MONDAY IF THE NEW ECMWF IS CORRECT.
REST OF NEXT WEEK CONTINUES TO SHOW A SOMEWHAT ACTIVE PATTERN...WITH
MODELS IN VERY GOOD AGREEMENT SHOWING SHORTWAVE TROUGHS MOVING
THROUGH TUESDAY NIGHT INTO WEDNESDAY...AS WELL AS ON THURSDAY.
HOWEVER...NONE OF THESE TROUGHS LOOK TO HAVE A LOT OF MOISTURE WITH
THEM...LIKELY SHUNTED OFF BY THE DEEPER SUNDAY NIGHT/MONDAY TROUGH.
FOLLOWED A CONSENSUS APPROACH GIVEN THE GOOD AGREEMENT...RESULTING
IN MOSTLY 20-40 PERCENT CHANCES FOR THESE TROUGHS. TEMPERATURES WILL
BE WARMER NEXT WEEK THAN THIS WEEK...THANKS TO THE MAIN POLAR
WESTERLIES SHIFTING WELL NORTH INTO CANADA. IT DOES NOT APPEAR THAT
ENOUGH WARM AIR ENTERS ANY OF THE TROUGHS TO RESULT IN LIQUID
PRECIPITATION...THOUGH.
&&
.AVIATION...THROUGH 06Z SATURDAY
1130 PM CST THU JAN 19 2012
CONTINUED FOCUS IS FOR THE SNOW ON FRIDAY...MAINLY WHEN IT WILL
START AND STOP ALONG WITH WHEN THE HEAVIEST SNOW WILL FALL. 20.00Z
UPPER AIR SOUNDINGS FROM MPX AND DVN SHOW A FAIRLY DRY LOW LEVEL
LAYER FROM THE SURFACE ON UP TO 800MB THAT WILL HAVE TO BE WORKED
ON BEFORE THE SNOW CAN REACH THE GROUND. THE LATEST TREND IN THE
SHORT TERM GUIDANCE IS TO PUSH THE START TIME BACK A FEW HOURS DUE
TO THE LOW LEVEL DRY LAYER THAT THE SNOW WILL HAVE TO WORK ON
INITIALLY. OTHERWISE...SNOWFALL RATES WILL LIKELY BE THE STRONGEST
FROM LATE MORNING INTO THE EARLY AFTERNOON WITH VISIBILITY
DROPPING TO 1/4SM TO 1/2SM OVER THIS PERIOD. THIS SNOW SHOULD COME
TO AN END LATE IN THE AFTERNOON AT RST AND EARLY IN THE EVENING AT
LSE...BUT SOME MVFR TO IFR CEILINGS MAY HANG ON THROUGH THE
NIGHT...SO HAVE PLAYED IT A BIT PESSIMISTIC ON CIGS GOING TO 6Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
320 PM CST THU JAN 19 2012
WI...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST FRIDAY FOR
WIZ041>044-053>055-061.
MN...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST FRIDAY FOR
MNZ086>088-094>096.
IA...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST FRIDAY FOR
IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1146 PM CST SAT JAN 21 2012
.DISCUSSION...
ISSUED 850 PM CST SAT JAN 21 2012
HIGH PRESSURE OVER THE EASTERN GREAT LAKES WILL CONTINUE TO PUSH
AWAY FROM THE AREA TONIGHT. THIS SHOULD ALLOW WINDS TO SHIFT MORE
INTO THE SOUTHEAST LATER TONIGHT AND INCREASE IN SPEED. THAT
COMBINED WITH CLOUDS MOVING BACK ACROSS THE ENTIRE FORECAST AREA
SHOULD PUT A HALT TO THE EARLY EVENING TEMP DECLINE. RUC SOUNDINGS
SHOWING THE POTENTIAL FOR SOME FREEZING DRIZZLE TOWARDS SUNDAY
MORNING WITH THE DEPTH OF THE LOW LEVEL MOISTURE INCREASING TO
BETWEEN 2500-3000 FEET...WITH DRY AIR LOCATED ABOVE. TEMPS..EXCPT
IN THE FAR NORTH WHERE THE CLOUDS HAVE NOT REACHED YET...SHOULD
BE STEADY OR SLOWLY RISE THE REST OF THE NIGHT. UPDATED EARLIER
TO ADJUST THE OVERNIGHT LOW TEMPS ACRS THE NORTH DUE TO THE LIGHT
SNOW COVER...CLEAR SKIES AND LIGHT WINDS.
QUICK LOOK AT THE NEW NAM-WRF NOT SHOWING MUCH CHANGE REGARDING THE
STORM SYSTEM FOR TOMORROW. OUR BEST CHANCE FOR STRONG TO SEVERE
THUNDERSTORMS WILL BE ALONG AND SOUTHEAST OF AN EFFINGHAM TO PARIS
LINE. STILL SEEING TREMENDOUS WIND FIELDS ASSOCIATED WITH THE DEEPENING
UPPER AND SURFACE WAVES WITH 500 MB WINDS OF 95KTS OVR SOUTHERN IL
TOMORROW EVENING. LOOKS TO BE A CLASSIC COOL SEASON SEVERE WEATHER
EVENT WITH LOW CAPE/HIGH SHEAR VALUES. ONCE THE STORMS DEVELOP EARLY
TOMORROW EVENING...IT SHOULDN`T TAKE LONG FOR THEM TO PUSH NNE THRU
SOUTHEAST IL WITH CELL MOTION BEING NE AT 60 KTS. PRIMARY TIME FRAME
FOR ACTIVE WEATHER OVER SOUTHEAST IL WOULD BE FROM 6PM UNTIL MIDNIGHT.
&&
.AVIATION...
ISSUED 1135 PM CST SAT JAN 21 2012
LITTLE CHANGE FROM PREVIOUS DISCUSSION. IFR CIGS HAVE MOVED OVER
THE ENTIRE AREA AND ARE EXPECTED TO BE AROUND THRU SUNDAY EVENING.
STRONG STORM EXPECTED TO IMPACT THE AREA LATER TOMORROW AFTN THRU
EARLY EVENING WITH GUSTY WINDS AND SHOWERS...ESPECIALLY IN AREAS
ALONG AND EAST OF I-55 WITH ISOLD STRONG CONVECTION MAY OCCUR
BETWN 23Z AND 04Z. MAIN THREAT WITH ANY STORMS WILL BE WITH
STRONG WINDS AS FORECAST SOUNDINGS INDICATE 50-60 KT WINDS WILL
BE COMMON BTWN 1000-2000 FEET AGL. FOR NOW WILL INDICATE VCTS AS
COVERAGE OF STORMS LOOKS LIMITED IN OUR AREA WITH THE MAIN AREA
OF CONVECTION OCCURRING JUST SOUTH AND EAST OF DEC AND CMI.
LOW LEVEL WIND SHEAR IS BORDERLINE FOR SPI AND PIA AND THAT WOULD
BE AFTR 09Z. BUT IT APPEARS WE MAY SEE SOME GUSTS OCCURRING AT THE
SFC BY DAWN SO WILL HOLD OFF FOR NOW. COLD FRONT EXPECTED TO MOVE
ACROSS THE AREA BTWN 00Z-04Z WITH WINDS AHEAD OF THE FRONT OUT OF
THE SE AND THEN SHOULD VEER MORE INTO THE SOUTH AND THEN SOUTHWEST
AS THE FRONT SHIFTS OFF TO OUR EAST AFTR 06Z. WINDS WILL AVERAGE
FROM 15 TO 20 KTS BY MID TO LATE MORNING AND CONTINUE THRU THE AFTN
WITH GUSTS ARND 30 KTS AT TIMES.
SMITH
&&
.PREV DISCUSSION...
ISSUED 300 PM CST SAT JAN 21 2012
SHORT TERM...TONIGHT THROUGH TUESDAY...
FORECAST FOCUS IN THE SHORT TERM WILL BE ON THE EVOLUTION OF THE
STRONG UPPER WAVE NOW MOVING THROUGH NV. THE TROUGH WILL DEEPEN AND
INDUCE RAPID CYCLOGENESIS IN THE AREA OF KS/NEB BY SUNDAY MORNING.
THE RESULTANT PRESSURE FALLS WILL SPREAD EASTWARD THROUGH THE DAY
WITH INCREASING SOUTHERLY LOW LEVEL FLOW BRINGING STRONG MOISTURE
FLUX FROM A WIDE-OPEN GULF OF MEXICO. EXPECT LOW CLOUDS TO INCREASE
AGAIN LATER TONIGHT WELL AHEAD OF THE SYSTEM WITH TEMPERATURES
RISING AFTER MIDNIGHT. SOME FREEZING DRIZZLE WILL BE POSSIBLE IN THE
MORNING UNTIL THE TEMPERATURES WARM ABOVE FREEZING...WHICH SHOULD BE
BY NOON. BY AFTERNOON...SOME SCATTERED ELEVATED SHOWERS WILL BE
POSSIBLE WITHIN THE LARGELY UNFOCUSED WARM ADVECTION REGIME OVER IL.
BY 00Z MONDAY...THUNDERSTORMS WILL BE INCREASING ALONG THE PACIFIC
FRONT ASSOCIATED WITH THE UPPER TROUGH WHICH WILL BE TAKING ON A
NEGATIVE TILT AS IT MOVES ACROSS THE MIDDLE MS VALLEY. THE NEGATIVE
TILT CONFIGURATION WILL CAUSE STRONG DIFFERENTIAL PVA WHICH WILL
ENHANCE LARGE-SCALE ASCENT...WHILE A STRONG/VEERING WIND PROFILE
PROMOTES LARGE VALUES OF BULK SHEAR AND LOW LEVEL HELICITY.
INSTABILITY WILL NOT BE PARTICULARLY HIGH BUT IT WILL BE ADEQUATE
FOR VIGOROUS UPDRAFTS WITHIN THE STRONGLY FORCED AIRMASS...WITH
SHEAR PROFILES FAVORING MESOCYCLONE/TORNADO FORMATION. TORNADOES
WILL BE MOST PREVALENT DURING THE INITIAL PHASES OF STORM FORMATION
TO OUR SOUTHWEST...BUT SUPERCELLS AND QLCS STORMS WILL BE POSSIBLE
IN THE EARLY TO MID EVENING AS FAR NORTHEAST AS THE INTERSTATE 70
CORRIDOR. WILL THEREFORE GO CATEGORICAL FOR POPS AND THUNDER FOR THE
EVENING HOURS. THE SHORT RANGE MODELS HAVE DIFFERENCES IN TIMING...
WITH SOME SUGGESTING THE STORMS WILL BE INTO INDIANA BY 06Z...AND
OTHERS ON THE SLOWER SIDE. WILL KEEP SOME CHANCE POPS FOR SHOWERS
AFTER 06Z MONDAY IN THE FAR EASTERN COUNTIES.
GUSTY WEST/NORTHWEST WINDS WILL BRING COLD ADVECTION INTO THE AREA
AS THE SURFACE/UPPER LOW DEEPENS AND BECOMES VERTICALLY STACKED OVER
THE GREAT LAKES ON MONDAY. AN EXTENSIVE AREA OF WRAP-AROUND MOISTURE
WILL BE LIKELY WITH A SLIGHT CHANCE OF SOME LIGHT SNOW OVER THE
NORTHERN AREAS ALONG INTERSTATE 74. TUESDAY SHOULD BE DRY AS HIGH
PRESSURE MOVES THROUGH THE MIDWEST.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
ACTIVE NORTHERN AND SOUTHERN STREAMS WILL BE THE RULE THROUGH THE
EXTENDED PERIOD. MODELS ARE STARTING TO COME TOGETHER WITH KEEPING
THE TWO STREAMS MOSTLY SEPARATED. NORTHERN STREAM WAVES ARE FORECAST
TO MOVE ACROSS THE US/CANADIAN BORDER INTO THE GREAT LAKES WITH
ASSOCIATED COLD FRONTS MOVING THROUGH IL BOTH THURSDAY AND FRIDAY.
THESE FRONTS SHOULD BE DRY AS THEY PASS THROUGH THE AREA AS THE
DYNAMICS REMAIN TO THE NORTH AND QUALITY MOISTURE STAYS BOTTLED UP
OVER THE GULF STATES AND APPALACHIANS. A WAVE ALONG THE THURSDAY
FRONT MAY BRING SOME RAIN TO SOUTHERN IL...SO WILL HAVE SOME CHANCE
AND SLIGHT CHANCE POPS FOR THE SOUTHEASTERN COUNTIES WEDNESDAY
NIGHT.
MEANWHILE IN THE SOUTHERN STREAM...A CUTOFF LOW OVER MEXICO
JUST SOUTHWEST OF THE RIO GRANDE IS FORECAST TO WEAKEN AS IT MOVES
EAST-NORTHEAST TOWARD THE LOWER MS VALLEY BY THE END OF NEXT WEEK.
THERE REMAINS SOME MODEL DIFFERENCES WITH THIS FEATURE...BUT EVEN
THE NORTHERN-MOST DGEX MODEL KEEPS MOST OF THE PRECIPITATION TO THE
SOUTH OF THE FORECAST AREA. THE GFS AND ECMWF MODELS KEEP THE
PRECIPITATION EVEN FURTHER SOUTH. SO THE BOTTOM LINE WILL BE A DRY
EXTENDED PERIOD WITH THE EXCEPTION OF THE CHANCE POPS OVER THE
SOUTHEAST WEDNESDAY NIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
314 AM CST SUN JAN 22 2012
.DISCUSSION...
TODAY-TONIGHT:
INITIAL ISSUE IS EVOLUTION OF LOW CLOUDS...WITH RUC STRUGGLING TO
STAY IN THE BALLPARK AND OTHERS EVEN WORSE. GIVEN TRENDS...SHOULD
SEE SLOW IMPROVEMENT THROUGHOUT THE MORNING ON WESTERN EDGE...BUT
SOUTHEAST KS WILL BE VERY SLOW TO CLEAR. SOME PATCHY DRIZZLE IS
POSSIBLE IN SOUTHEAST KS...FORTUNATELY TEMPERATURES WILL BE ABOVE
FREEZING. ALL MODELS SHOW SIGNIFICANT DRY SLOT WORKING ACROSS
SOUTHERN SECTIONS DURING THE AFTERNOON AHEAD OF COLD AIR
ADVECTION. MEANWHILE SURFACE PRESSURE GRADIENT AND LAPSE RATES
SHOULD SPREAD LOW END WIND ADVISORY CRITERIA OVER THE AREA WEST OF
A SLN-HARPER LINE FOR A FEW HOURS THIS AFTERNOON. WITH ARRIVAL OF
850MB MOISTURE...SHOULD SEE SPRINKLES/LIGHT RAIN DEVELOP THIS
AFTERNOON IN CENTRAL KS...AND SPREAD INTO THE FLINT HILLS FOR A
FEW HOURS THIS EVENING. LOOKS LIKE TEMPERATURES WILL BE WARM
ENOUGH THIS AFTERNOON/EVENING FOR PRECIPITATION TO REMAIN LIQUID.
DOWNGLIDE SHOULD QUICKLY SHUT DOWN PRECIPITATION IN THE EVENING.
WINDS WILL LIKELY REMAIN BRISK FOR MUCH OF THE NIGHT. A TOUGH CALL
ON LOWS GIVEN THE OPPOSITE IMPACTS OF WINDS AND COLD AIR ADVECTION.
MON-MON NIGHT:
RELATIVELY QUIET WEATHER ANTICIPATED WITH TEMPERATURES STILL
REMAINING AT OR ABOVE NORMAL.
TUE-TUE NIGHT:
PLAN TO STAY THE COURSE ON PRECIPITATION THIS PERIOD. MODELS
STILL STRUGGLING TO CONVERGE AS TO HOW FAR NORTH LOW LEVEL
MOISTURE WILL GO. HOWEVER BOTH GFS/ECMWF HAVE BEEN CONSISTENT THAT
EXTENSIVE HIGH CLOUDS WILL COVER THE AREA DURING THE DAY ON TUE.
USUALLY AM NOT AS CONFIDENT IN HIGH LEVEL MOISTURE MODEL
FORECASTS BEYOND DAYS 1-2...BUT THIS SEEMS REASONABLE GIVEN THE
DIFFLUENT UPPER FLOW NE OF UPPER LOW. GIVEN THE COOL START...LIGHT
SOUTHEAST WINDS AND EXTENSIVE CLOUDS...TEMPERATURES SHOULD STRUGGLE.
WED-SUN:
00 UTC RUN OF THE ECMWF HAS BROKE CONTINUITY...WITH NEW RUN
RESEMBLING THE 20/12 UTC RUN. THIS IS A FASTER/DEEPER SOLN. GFS
MEANWHILE HAS BEEN STRUGGLING AS WELL...ALTHOUGH FORECAST AREA
REMAINS IN BETWEEN THE US-CANADIAN BORDER SURFACE LOW AND
INCONSISTENT WEAK UPPER LOW IN THE SOUTHERN PLAINS. NET RESULT AT
LEAST FOR NOW IS DRY AND ABOVE NORMAL TEMPERATURES. OTHERWISE WILL
NEED TO WAIT FOR MORE CONSISTENCY BEFORE MAKING ANY SUBSTANTIAL
CHANGES. -HOWERTON
&&
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
STRATUS CLOUDS HAVE ARRIVED AHEAD OF SCHEDULE MAINLY EAST OF THE
KANSAS TURNPIKE LATE THIS EVENING. AREAS MOST LIKELY TO BE IMPACTED
BY MVFR CIGS THROUGH THE MORNING HOURS ON SUNDAY WILL BE KICT AND
KCNU. IFR/LIFR WILL BE POSSIBLE THROUGH THE EARLY MORNING HOURS AT
KCNU WITH AREAS OF DRIZZLE WITHIN AN AREA OF LOW LEVEL
WAA/MOISTURE ADVECTION. INCREASING LARGE-SCALE FORCING FOR
SUBSIDENCE AND LOW LEVEL DRY AIR WILL SWEEP ACROSS THE AREA IN THE
WAKE OF A PRE-FRONTAL TROUGH DURING THE EARLY AFTERNOON HOURS WITH
A RETURN TO VFR ACROSS THE AREA. IN ADDITION...STRONG
WEST/NORTHWEST WINDS AROUND 25-35 KNOTS WILL BE POSSIBLE ACROSS
PORTIONS OF CENTRAL AND SOUTH CENTRAL KANSAS THROUGH THE AFTERNOON
HOURS.
MWM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 48 25 51 27 / 20 10 0 0
HUTCHINSON 46 26 49 27 / 30 10 0 0
NEWTON 48 27 48 27 / 30 10 0 0
ELDORADO 53 27 50 27 / 10 10 0 0
WINFIELD-KWLD 57 27 56 29 / 10 10 0 0
RUSSELL 45 22 50 22 / 30 10 0 0
GREAT BEND 43 22 50 22 / 30 10 0 0
SALINA 46 26 51 23 / 30 10 0 0
MCPHERSON 46 26 50 25 / 30 10 0 0
COFFEYVILLE 59 31 53 29 / 10 10 0 0
CHANUTE 53 29 50 26 / 10 10 0 0
IOLA 50 30 49 27 / 10 10 0 0
PARSONS-KPPF 56 27 52 26 / 10 10 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM CST THIS EVENING
FOR KSZ032-033-047>051-067-082-091.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1145 PM MST SAT JAN 21 2012
.UPDATE...
1110 PM MST SAT JAN 21 2012
NEEDED TO GET AN UPDATE ALREADY FOR TOMORROWS WIND AND WEATHER.
LATEST MODEL DATA SLOWER...STRONGER...AND COLDER WITH INCOMING
SYSTEM. NO MATTER WHICH MODELS WAS CHOSEN...HIGH WIND WARNING
CRITERIA LOOKS TO BE MET ACROSS THE ENTIRE AREA WITH THE HIGHEST
SPEEDS AND GUSTS IN THE WESTERN PORTION OF MY AREA. SO HAVE ISSUED
A HIGH WIND WARNING FROM 13Z TO 01Z FOR ALL OF MY CWA. SINCE MODELS
ARE COLDER...NOT ONLY IS IT PRODUCING WIDESPREAD LIGHT PRECIPITATION
BUT HAS THE PHASE AS SNOW...ESPECIALLY ALONG AND NORTH OF THE
INTERSTATE. WITH THE WIND OCCURRING...THAT WILL ALSO CAUSE AREAS
OF BLOWING SNOW. CHOSE TO KEEP THE PACKAGE/FORECAST AS SIMPLE AS
POSSIBLE AND HANDLED THE SNOW/BLOWING SNOW WITH ENHANCED WORDING
IN THE HWO AND NPW. WITH THE UPDATE...WILL BE DOING FINE TUNING OF
THOSE GRIDS ALREADY SENT AS NEEDED.
BULLER
&&
.DISCUSSION...
825 PM MST SAT JAN 21 2012
LATEST 00Z NAM SHOWING THE UPPER TROUGH THAT IS TO MOVE ACROSS THE
AREA SUNDAY A BIT SLOWER THAN PREVIOUSLY FORECAST. ITS ALSO
SHOWING STRONGER LOW LEVEL NORTH WINDS AND SLIGHTLY COLDER 850MB
TEMPERATURES. 00Z MET GUIDANCE WINDS AND POPS HAVE INCREASED AS
WELL WITH NEAR CATEGORICAL POPS AT KMCK. 21Z SREF POPS AND WINDS
ALSO RATHER BULLISH. 00Z RUC SHOWING A BIT MORE WIDESPREAD QPF AS
WELL. NO 00Z GFS TO LOOK AT QUITE YET.
IN A NUTSHELL...MAY SEE A BIT MORE WIDESPREAD PRECIPITATION WITH
PERHAPS A BIT MORE SNOW VS A RAIN/SNOW MIX...MAINLY ALONG AND
NORTH OF THE INTERSTATE. ALSO...WINDS MAY BE A BIT HIGHER THEN
CURRENTLY ADVERTISED AND WITH THE POSSIBLE MORE COMMON PRECIP-TYPE
AS SNOW PRODUCE SOME RESTRICTED VISIBILITIES.
007
&&
.AVIATION...
1020 PM MST SAT JAN 21 2012
FOR THE 06Z TAFS AT KGLD AND KMCK...VFR EXPECTED THROUGH 15Z BEFORE
LOWERING TO IFR FROM 16Z-22Z (BOTH CIGS AND VIS) AS A POTENT BUT
QUICK MOVING UPPER LEVEL TROUGH AND COLD FRONT MOVE THROUGH. BY 00Z
AT BOTH TERMINALS SHOULD SEE CIGS AND VIS QUICKLY RISE TO VFR AND
CONTINUE THROUGH THE REST OF THE PERIOD. NORTHWEST WINDS OF 30-40KTS
WITH HIGHER GUSTS WILL BE COMMON. AT KGLD GUSTS OVER 50KTS EXPECTED
BETWEEN 16Z-21Z IN BOTH PRECIPITATION AND SUBSIDENCE BEHIND
DEPARTING WAVE. DURING THE TIME OF EXPECTED PRECIP SHOULD SEE
SHARPLY LOWER VISIBILITIES IN SNOW AND BLOWING SNOW.
007
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WARNING FROM 6 AM MST /7 AM CST/ TO 6 PM MST /7 PM
CST/ SUNDAY FOR KSZ001>004-013>016-027>029-041-042.
FIRE WEATHER WATCH FROM 11 AM MST SUNDAY THROUGH SUNDAY
AFTERNOON FOR KSZ013-027-041.
NE...HIGH WIND WARNING FROM 6 AM MST /7 AM CST/ TO 6 PM MST /7 PM
CST/ SUNDAY FOR NEZ079>081.
CO...HIGH WIND WARNING FROM 6 AM TO 6 PM MST SUNDAY FOR COZ090>092.
FIRE WEATHER WATCH FROM 11 AM MST SUNDAY THROUGH SUNDAY
AFTERNOON FOR COZ252>254.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1120 PM CST SAT JAN 21 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
AREA OF STRATUS SEEN ON SATELLITE MOVING NORTH WHILE LATEST
RUC/NAM/GFS FORECAST SOUNDINGS CONTINUE TO SHOW STRONG WARM AIR
ADVECTION AND ISENTROPIC LIFT INCREASING. BECAUSE OF THIS WILL
MAINTAIN PREV FORECAST WITH SOME ADJUSTMENTS ON TIMING THE ENTRANCE
OF LOW CIGS BASED ON SATELLITE. CONFIDENCE IS ABOUT 50/50 THAT CIGS
WILL BE IFR SINCE OBS UP STREAM OVER NORTHERN OK ARE GENERALLY MVFR.
NEVERTHELESS WITH STRONG ISENTROPIC LIFT CLOSE TO THE SFC THERE IS
THE POTENTIAL FOR IFR CIGS. WITH THE STRATUS LAYER RELATIVELY
SHALLOW AM NOT SURE HOW WIDESPREAD ANY DRIZZLE MAY BE. THEREFORE
WILL ONLY MENTION SOME BR BUT EVEN IF THERE IS SOME DRIZZLE WOULD
ANTICIPATE VSBY REMAINING 3SM OR BETTER. THE NAM/GFS ARE A LITTLE
SLOWER IN BRINGING THE WIND SHIFT THROUGH THE TERMINALS...SO THE LOW
STRATUS COULD STAY WITH US FOR A GOOD CHUNK OF THE DAY SUNDAY.
WOLTERS
&&
.PREV DISCUSSION... /844 PM CST SAT JAN 21 2012/
THE 00Z RUC AND NAM HAVE COME IN CONTINUING TO SHOW STRONG LOW LEVEL
WARM AIR ADVECTION. WITHIN THIS PATTERN AN AREA OF LOW CLOUDS IS
EXPECTED TO DEVELOP AND ADVECT NORTH INTO EASTERN KS WITH DECENT
ISENTROPIC LIFT WITHIN THE STABLE LAYER OF THE STRATUS. THIS COULD
DEVELOP SOME PATCHY DRIZZLE DURING THE MORNING SUNDAY. THE WARM AIR
ADVECTION AT THE SURFACE IS EXPECTED TO CAUSE TEMPS TO GRADUALLY
WARM THROUGH THE NIGHT...BUT THINK THE DRIZZLE COULD DEVELOP BEFORE
TEMPS WARM ABOVE FREEZING. FORECAST SOUNDINGS ALL SHOW SFC TEMPS
ABOVE FREEZING AROUND 7AM. WITH THIS IN MIND AND LITTLE OR NO
ACCUMULATIONS ANTICIPATED IN THE PRE DAWN HOURS...WILL NOT ISSUE ANY
HEADLINE OTHER THAN TO UPDATE THE HAZARDOUS WEATHER OUTLOOK.
OTHERWISE THE FORECAST LOOKS TO BE ON TRACK WITH RESPECT TO THE NEW
NAM REGARDING THE UPPER WAVE FOR SUNDAY AFTERNOON AND SUNDAY
EVENING.
WOLTERS
/329 PM CST SAT JAN 21 2012/
THROUGH SUNDAY NIGHT...WEAK LOW LEVEL ISENTROPIC ASCENT WORKED WITH
LIMITED MOISTURE TODAY TO PRODUCE A STUBBORN STRATUS CLOUD DECK
ACROSS MUCH OF THE AREA. INCREASED MIXING AND WARM ADVECTION HAS
FINALLY BEGUN TO ERODE THE CLOUDS FROM SOUTHWEST TO NORTHEAST WITH
THE INCREASING SUNSHINE AND SOUTH WINDS HELPING TO WARM TEMPS TO 30
DEGREES AND ABOVE. THE INCREASING SOUTH WINDS ARE IN RESPONSE TO AN
INCOMING UPPER LEVEL STORM SYSTEM AND ASSOCIATED SURFACE LOW
PRESSURE. THE SURFACE LOW WAS RAPIDLY DEEPENING IN THE HIGH PLAINS
WITH PRESSURE FALLS AT 2 MB PER HOUR THIS AFTERNOON. WINDS WILL
INCREASE ACROSS THE AREA OVERNIGHT AND BECOME GUSTY WITH STRONG WARM
ADVECTION ACROSS THE PLAINS. THUS...LOW TEMPS TONIGHT WILL LIKELY
OCCUR SHORTLY AFTER SUNSET WITH TEMPERATURES THEN RISING FROM
MIDNIGHT THROUGH SUNDAY AFTERNOON.
THE STORM SYSTEM AS A WHOLE WILL BE FAST MOVING WITH THE COLD FRONT
ENTERING THE FORECAST AREA AROUND NOON AND PUSHING INTO MISSOURI BY
7 PM. NORTHWEST WINDS WILL BE STRONG IMMEDIATELY BEHIND THE FRONT
AND MAY FLIRT WITH WIND ADVISORY CRITERIA BUT HAVE NOT ISSUED
ANYTHING AT THIS POINT AS IT WILL BE BORDERLINE. TEMPERATURES WILL
ALSO REMAIN FAIRLY WARM BEHIND THE FRONT. THERE WILL BE PLENTY OF
COLD ADVECTION ALOFT IN RELATION TO THE VERY WARM TEMPS IN PLACE BUT
STILL A PACIFIC AIRMASS AND NOT PARTICULARLY COLD RELATIVE TO
TYPICAL JANUARY TEMPS.
AS FAR AS PRECIP CHANCES ARE CONCERNED...IT APPEARS THAT DRIZZLE
WILL BE POSSIBLE ACROSS EASTERN KANSAS DURING THE MORNING HOURS IN
THE WARM MOIST ADVECTION REGIME WITH AMPLE ISENTROPIC ASCENT IN THE
LOW LEVELS. A BETTER CHANCE FOR MEASURABLE PRECIP WILL COME BEHIND
THE COLD FRONT AS THE MAIN UPPER PV ANOMALY MOVES OVERHEAD. DEEP
MOISTURE IS LIMITED...ESPECIALLY WITHIN THE DENDRITIC ZONE BUT LIFT
MAY BE SUFFICIENT TO BRING A BAND OF PRECIP ACROSS THE AREA. THE
BEST CHANCES APPEAR TO BE NORTH OF I-70 BUT COULD EXTEND SOUTH IF
MOISTURE QUALITY IS SUFFICIENT. TEMPERATURE PROFILES ARE BORDERLINE
FOR RAIN CHANGING TO SNOW...AGAIN WITH THE BEST CHANCE FOR LIGHT
SNOW NORTH OF I-70. LITTLE TO NO ACCUMULATION IS EXPECTED. ANY
PRECIP WILL MOVE EAST OF THE AREA BY MIDNIGHT.
BARJENBRUCH
MONDAY THROUGH SATURDAY...EXPECT PRECIP TO COME TO AN END BY EARLY
MONDAY MORNING AS THE UPPER LOW SLIDES OFF TO THE EAST...ALLOWING
FOR LARGE SCALE SUBSIDENCE TO TAKE OVER. FOR THE FIRST HALF OF NEXT
WEEK SHORT WAVE RIDGING WILL MOVE INTO NORTHEAST KANSAS WHICH SHOULD
KEEP MILD TEMPERATURES ACROSS THE AREA FOR MOST OF THE WEEK.
SOUTHERLY WINDS IN RESPONSE TO AN INVERTED TROUGH WHICH WILL LIKELY
TAKE SHAPE OVER THE FAR SOUTHERN HIGH PLAINS. THE WARM UP WILL BE
TEMPERED...ESPECIALLY IN FAR NORTHERN KANSAS AS THE WEAKLY DEFINED
WARM FRONT WILL HAVE A TOUGH TIME REACHING THE KS/NE BORDER.
NONETHELESS THE ENTIRE NORTHEASTERN KANSAS AREA WILL LIKELY SEE
ABOVE NORMAL TEMPS THROUGHOUT THE WEEK WITH HIGHS REGULARLY REACHING
THE MID 40S TO LOWER 50S. NEXT CHANCE FOR PRECIPITATION WILL COME ON
TUESDAY NIGHT OR WEDNESDAY MORNING AS A QUICKLY MOVING NORTHERN
STREAM TROUGH GLIDES THROUGH THE AREA. WITH LOW LEVEL DRY AIR
REMAINING IN PLACE AND MEAGER LIFT DO NOT EXPECT MUCH IN THE WAY OF
PRECIP FROM THIS FLEETING SYSTEM. A SOUTHERN STREAM CUTOFF LOW WILL
BE A BIT MORE DISCERNIBLE DURING THIS TIME PERIOD...HOWEVER MODELS
HAVE BEEN TRENDING THIS CUTOFF LOW FURTHER SOUTH WITH EACH RUN...SO
DO NOT EXPECT ANNY PRECIP FROM THIS TROUGH. ASIDE FROM THIS SLIGHT
CHANCE FOR PRECIP MIDWEEK EXPECT THE REMAINING PORTION OF THE
EXTENDED FORECAST TO REMAIN EVENT FREE WITH MILD TEMPS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1020 PM MST SAT JAN 21 2012
.DISCUSSION...
825 PM MST SAT JAN 21 2012
LATEST 00Z NAM SHOWING THE UPPER TROUGH THAT IS TO MOVE ACROSS THE
AREA SUNDAY A BIT SLOWER THAN PREVIOUSLY FORECAST. ITS ALSO
SHOWING STRONGER LOW LEVEL NORTH WINDS AND SLIGHTLY COLDER 850MB
TEMPERATURES. 00Z MET GUIDANCE WINDS AND POPS HAVE INCREASED AS
WELL WITH NEAR CATEGORICAL POPS AT KMCK. 21Z SREF POPS AND WINDS
ALSO RATHER BULLISH. 00Z RUC SHOWING A BIT MORE WIDESPREAD QPF AS
WELL. NO 00Z GFS TO LOOK AT QUITE YET.
IN A NUTSHELL...MAY SEE A BIT MORE WIDESPREAD PRECIPITATION WITH
PERHAPS A BIT MORE SNOW VS A RAIN/SNOW MIX...MAINLY ALONG AND
NORTH OF THE INTERSTATE. ALSO...WINDS MAY BE A BIT HIGHER THEN
CURRENTLY ADVERTISED AND WITH THE POSSIBLE MORE COMMON PRECIP-TYPE
AS SNOW PRODUCE SOME RESTRICTED VISIBILITIES.
007
&&
.AVIATION...
1020 PM MST SAT JAN 21 2012
FOR THE 06Z TAFS AT KGLD AND KMCK...VFR EXPECTED THROUGH 15Z BEFORE
LOWERING TO IFR FROM 16Z-22Z (BOTH CIGS AND VIS) AS A POTENT BUT
QUICK MOVING UPPER LEVEL TROUGH AND COLD FRONT MOVE THROUGH. BY 00Z
AT BOTH TERMINALS SHOULD SEE CIGS AND VIS QUICKLY RISE TO VFR AND
CONTINUE THROUGH THE REST OF THE PERIOD. NORTHWEST WINDS OF 30-40KTS
WITH HIGHER GUSTS WILL BE COMMON. AT KGLD GUSTS OVER 50KTS EXPECTED
BETWEEN 16Z-21Z IN BOTH PRECIPITATION AND SUBSIDENCE BEHIND
DEPARTING WAVE. DURING THE TIME OF EXPECTED PRECIP SHOULD SEE
SHARPLY LOWER VISIBILITIES IN SNOW AND BLOWING SNOW.
007
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY FROM 6 AM MST /7 AM CST/ TO 5 PM MST /6 PM CST/
SUNDAY FOR KSZ002>004-015-016-027>029-041-042.
HIGH WIND WATCH FROM 6 AM MST /7 AM CST/ SUNDAY THROUGH SUNDAY
AFTERNOON FOR KSZ001-013-014.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON
FOR KSZ013-027-041.
NE...WIND ADVISORY FROM 6 AM MST /7 AM CST/ TO 5 PM MST /6 PM CST/
SUNDAY FOR NEZ079>081.
CO...WIND ADVISORY FROM 6 AM TO 5 PM MST SUNDAY FOR COZ092.
HIGH WIND WATCH FROM 6 AM MST SUNDAY THROUGH SUNDAY AFTERNOON
FOR COZ090-091.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON
FOR COZ252>254.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1212 AM EST SUN JAN 22 2012
UPDATED FOR 06Z AVIATION DISCUSSION
.SYNOPSIS... ISSUED AT 352 PM EST
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR LKS BTWN ARCTIC VORTEX CENTERED OVER HUDSON BAY ASSOCIATED
WITH RECENT INTENSE CHILL AND PROGRESSIVE UPR RDG SHIFTING E THRU
THE NRN PLAINS. SFC/H85 RDG AXIS HAS BROUGHT RELATIVELY TRANQUIL WX
TO THE FA TDAY WITH MID LVL DRY AIR SHOWN ON THE 12Z GRB RAOB. TEMPS
HAVE RISEN STEADILY FM MRNG LOWS ARND -25F OVER THE INTERIOR W. SOME
LES LINGERS EARLY THIS AFTN OVER THE KEWEENAW AND IN AREAS WELL E OF
MQT WITH H85 TEMPS STILL AOB -15C...BUT BACKING LLVL FLOW TO THE SW
THAT SIGNALS A RETREAT OF THE ARCTIC AIR IS CAUSING THE SHSN TO
DRIFT TO THE NE. IN FACT...WAD MID CLD BEST DEPICTED BY THE RH SHOWN
ON THE 12Z NAM 290-295K ISENTROPIC SFCS/H6-7/ AND WELL IN ADVANCE OF
SHARP H85 WARM FNT PUSHING THRU THE NRN PLAINS IS ALREADY MOVING FM
NRN MN INTO THE WRN CWA. BUT GENERALLY DRYNESS OF THE 12Z INL RAOB
IS PREVENTING ANY PCPN. SOME -SN IS SHOWING UP NEAR LK WINNIPEG. TO
THE S...THERE IS QUITE A BIT OF LO CLD S OF THE HI CENTER IN
WI...AND THIS ST/SC IS STARTING TO STREAM NWD INTO SW MN. FARTHER
W...12Z H85 TEMPS WERE UP TO 6C IN THE LEE OF THE ROCKIES BEHIND THE
WARM FNT. A VIGOROUS SHRTWV IS DIGGING SEWD INTO THE SW STATES.
THERE HAVE BEEN A FEW LTG STRIKES NEAR THE TRACK OF THIS
FEATURE...AND NEARBY PIREPS INDICATE H3 WIND SPEEDS UP TO 175KT
WITHIN SUPPORTING UPR JET THAT IS WELL DEFINED ON WV IMAGERY.
&&
.SHORT TERM /TNGT AND SUN/... ISSUED AT 352 PM EST
MAIN FCST CONCERNS IN THIS PERIOD ARE IMPACT OF RETURNING WARM AIR
IN VIGOROUS WAD PATTERN THAT WL SET UP IN RETURN SLY FLOW BTWN
DEPARTING HI PRES RDG TO THE E AND DVLPG LO PRES IN THE PLAINS
ASSOCIATED WITH VIGOROUS HGT FALLS IN ADVANCE OF SHRTWV NOW MOVING
INTO THE SW STATES.
TNGT...WITH STRENGTHENING LLVL SLY FLOW...EXPECT ANY LES NEAR LK SUP
TO DRIFT OFFSHORE BY LATE IN THE AFTN. SINCE THE AIRMASS WL STILL BE
COLD ENUF FOR LES EARLY WITH H85 TEMPS ARND -12C...GOING FCST OF
SOME LK CLD/SHSN OFF LK MI INTO THE FM ISQ-ERY STILL LOOKS ON TRACK.
BUT THIS PCPN SHOULD DIMINISH AS TEMPS RISE THRU THE NGT. IN FACT...
H85 WIND INCRSG UP TO 50KTS TOWARD WRN LK SUP BY 12Z SUN ARE FCST TO
PUSH H85 TEMPS NEAR 0C IN THAT AREA TOWARD DAYBREAK. THIS
STRENGTHENING SSW FLOW WL ALSO DRAW THE LO CLD NOW WELL TO THE S
INTO THE WRN AND CNTRL CWA. BUT DOWNSLOPE NATURE OF THE FLOW OVER
THE W AND NCNTRL SHOULD RESULT IN SOME DISSIPATION OF THIS CLD
COVER. TO THE NW...THE AREA OF SN NOW NEAR LK WINNIPEG WL LIKELY
SHIFT NEAR ISLE ROYALE WITH PERSISTENT ISENTROPIC ASCENT SHOWN ON
THE 290-295K SFCS...MORE SATURATED PROFILE DOWN TO THE SFC...AND
INCRSG UPR DVGC IN RRQ OF H3 JET MAX IN ONTARIO AND IN EXIT REGION
OF ANOTHER UPR JET EMERGING ON THE E SIDE OF DEEPENING UPR TROF IN
THE PLAINS. WITH 5-6K FT DEEP DRY WEDGE SHOWN ON FCST SDNGS FOR
CMX...SUSPECT THE BULK OF THIS PCPN WL REMAIN TO THE NW OF THE
KEWEENAW. SO CUT POPS INTO THE CHC CATEGORY FOR THAT AREA WITH HIER
POPS TO THE N. EXPECT THE LOWEST TEMPS EARLY TNGT...WITH THE MERCURY
RISING LATER AS INCRSG S WIND ADVECTS MORE LLVL MSTR INTO THE AREA.
TENDED TO LOWER EARLY EVNG TEMPS OVER THE INTERIOR CNTRL BEFORE
ARRIVAL OF THICKER CLD COVER/ONSET OF STRONGER WINDS CAUSES TEMPS TO
RISE OVERNGT.
SUN...THE WX WL BE DOMINATED BY THE ARRIVAL OF INCRSG LLVL MSTR IN
STEADY SSE WIND BTWN DEPARTING HI PRES RDG AND DVLPG LO IN THE
PLAINS. ALTHOUGH CONTINUED WAD WL TEND TO RESULT IN INCRSG MID LVL
MSTR AS WELL...MODEL GUIDANCE INDICATES A PERSISTENT DRY WEDGE
CENTERED ARND H85 THRU THE DAY BTWN THE LLVL AND HIER LVL
MOISTENING. MAINTAINED MAINLY SCHC POPS FOR LARGER SCALE PCPN...HIER
TO THE NW. ANY PCPN WL LIKELY BE SN AND PSBLY SLEET WITH WARM
WEDGE/H85 TEMPS POTENTIALLY UP TO 5C IN THE DRY LYR THAT MIGHT MELT
SN FLAKES ABV RESIDUAL COLD AIR JUST ABV THE SFC...WHERE TEMPS ARE
FCST TO REMAIN AS LO AS -6C TO -8C. ALSO INCLUDED MENTION OF FZDZ
MAINLY OVER THE SCNTRL WHERE GUIDANCE SHOWS INCRSG SFC DEWPTS IN
AREA OF UPSLOPE SSE FLOW. LIMITING FACTOR WL BE FAIRLY HI SFC DEWPT
DEPRESSIONS NOW OBSVD TO THE S/STRONG WINDS THAT MIGHT MAINTAIN A
SLIGHT INVERTED V LLVL THERMAL/MSTR PROFILE.
.LONG TERM /SUNDAY NIGHT THROUGH NEXT SATURDAY/...
DEEPENING LOW PRESSURE OVER THE UPPER LAKES AND MIXED PRECIPITATION
ISSUES IS THE MAIN CONCERN OF THE LONG TERM.
BY SUNDAY EVENING...SHORTWAVE TROUGH WITH AT LEAST TWO EMBEDDED
SHORTWAVES/PV ANOMALIES WILL BE OVER THE CNTRL PLAINS. MAJORITY OF
MODELS AGREE IN THIS IDEA. 12Z NAM IS ON ITS OWN SHOWING STRONGER
PIECE OF ENERGY SHOOTING NORTH INTO MN. ALL OTHER GUIDANCE...SAVE
THE SREF WHICH HAS MANY NAM MEMBERS WITHIN IT...KEEPS STRONGEST
ENERGY MORE OVR SOUTHERN PLAINS. BASED ON POSITION OF UPPER JET
AHEAD OF TROUGH...THINK NAM IS TOO STRONG WITH SHORTWAVE OVR MN.
THIS LEADS TO A MUCH FARTHER NORTH TRACK TO SFC LOW ON MONDAY
(NORTHERN LK SUPERIOR MONDAY MORNING INSTEAD OF OVR SOUTHERN LK
MICHIGAN). SO AS MUCH AS WOULD HAVE LIKED TO HAVE THE HIGHER
RESOLUTION NAM THERMAL PROFILES TO USE IN THIS FCST...HAVE TO
DISCOUNT THE NAM AT THIS TIME. SHOULD NOTE THAT IT APPEARS THE 12Z
NAM IS TRENDING TOWARD MAJORITY OF OTHER MODELS...SO MAYBE IT WILL
BE MORE USEFUL IN 24 HRS. MOVING ON THAT LEAVES THE ECMWF AND UKMET
IDEA (WHICH HAVE BEEN CONSISTENT AND PREFERRED WITH THIS SYSTEM FOR
SOME TIME NOW) AS WELL AS THE GFS WHICH BEGAN TRENDING TOWARD
ECMWF/UKMET IDEA WITH THE 18Z RUN ON 1/20. CANADIAN ALSO PRETTY MUCH
IN LINE NOW AS WELL...THOUGH RUN-TO-RUN CONSISTENCY WITH SFC LOW
TRACK ON MONDAY STILL NOT THE GREATEST. SHOULD NOTE...12Z GFS DID
TREND A BIT TOWARD NAM IDEA AND WAS NOT PREFERRED BY HPC. 12Z
ECMWF/CANADIAN/UKMET REMAIN CONSISTENT WITH PREVIOUS MODEL RUNS.
APPEARS THAT THOUGH THERE IS SOME INTERACTION WITH NORTHERN STREAM
LATER MONDAY AND MONDAY NIGHT...THIS SYSTEM WILL BE MAINLY SOUTHERN
STREAM ORIGIN. WITH THAT WILL COME GOOD TAP OF GULF MOISTURE WITH
PWATS OVR 250 PCT OF NORMAL BY 12Z MONDAY OVR MOST OF THE CWA.
POSITION OF H85 TROUGH AND SRLY H85 WINDS PUT STRONGEST H85 THETA-E
ADVECTION OVER EAST HALF OF CWA BTWN 09Z-15Z MONDAY. HEAVIEST QPF IS
FCST OVR CNTRL AND EAST CWA. RUN TOTAL QPF THROUGH 00Z TUESDAY (WHEN
DEEPER MOISTURE/HIGHER PWATS SHIFT TO THE NORTHEAST INTO
ONTARIO/QUEBEC) RANGE FROM 0.50-0.90 OF AN INCH WITH CANADIAN UP OVR
1 INCH...HEAVIEST CNTRL CWA DUE TO DEFORMATION ON BACK EDGE OF
H85-H7 LOWS AND IT IS ALSO WHERE THERE IS A HINT OF A TROWAL HANGING
BACK OVR THE AREA AS H85-H7 LOWS MAINTAIN STEADY STRENGTH WHILE
HEADING INTO ONTARIO.
LOW-LEVEL THERMAL PROFILES WILL BE CRITICAL COMPONENT WITH THIS
SYSTEM...ESPECIALLY THROUGH NOON ON MONDAY. BASED ON 0C H85
LINE...RAIN WILL BE MAIN PTYPE EAST OF MARQUETTE AND DICKINSON
COUNTIES...WITH SNOW TO THE WEST. TROUBLE IS THAT SFC-BLYR TEMPS
WILL BE VERY CLOSE TO FREEZING AS THE RAIN ARRIVES FM THE SOUTH LATE
SUNDAY NIGHT. COULD EVEN BE SLEET OR SNOW RIGHT AT THE ONSET OF
PRECIPITATION SUNDAY NIGHT AS WELL AS COLD AIR ALOFT SLOWLY EVADES.
BELIEVE FREEZING RAIN WILL BE BIGGEST CONCERN TOWARD DAYBREAK MONDAY
AND THROUGH ABOUT MID MORNING...THEN BLYR WARMING IN THE EAST SHOULD
CHANGE PTYPE TO JUST RAIN. DUE TO COLD SPELL LATELY...WARMING OF
GROUND SFC TEMPS WILL LAG THE AIR TEMPS...SO MAY BE SITUATION WHERE
TEMPS AT OBSERVATION PLATFORMS (ASOS/AWOS/RAWS) ARE IN THE MID 30S
BUT THERE IS STILL ICING OCCURRING ON COLDER UNTREATED SURFACES.
UNFORTUNATELY...THESE THERMAL QUESTIONS ABOUND THE FIRST PART OF
MONDAY WHEN BULK OF HEAVIER QPF IS FCST WITH WARM AIR ADVECTION
ALOFT AT ITS PEAK. DO THINK THERE IS A GREATER THAN 50 PCT CHANCE
OF SIGNIFICANT ICING LATE SUNDAY NIGHT AND MONDAY MORNING...
ESPECIALLY AWAY FM THE IMMEDIATE SHORELINES OF LK SUPERIOR AND LK
MICHIGAN.
EVENTUALLY...BLYR WARMING WILL RESULT IN MOSTLY RAIN BY LATE MORNING
EAST OF MUNISING TO MENOMINEE AS SFC LOW IS FCST TO DEEPEN AND MOVE
FM SOUTHEAST WI TO SCNTRL UPR MI AND EVENTUALLY OUT OVR SOUTHEAST LK
SUPERIOR BY MONDAY EVENING. SITUATION COULD BECOME VERY FAVORABLE
FOR HEAVIER SNOW OVR CNTRL CWA THOUGH...MAINLY OVR HIGHER TERRAIN
JUST WEST OF MARQUETTE INTO PORTIONS OF KEWEENAW AND AS FAR SOUTH
AS WI BORDER...EVENTUALLY SPREADING INTO ALGER AND DELTA COUNTIES BY
LATE AFTN. PRIMARY DRIVER FOR POTENTIALLY HEAVIER SNOW IS VERY TIGHT
H85 TEMPERATURE GRADIENT OVR CNTRL CWA/INCREASING DEFORMATION ON
WEST SIDE OF CLOSED OFF H85-H7 LOWS AND LINGERING TROWAL REGION MOST
NOTED 950-750MB. NORTHERN STREAM WAVE DIGGING INTO THE SOUTHERN
STREAM SYSTEM WILL ALSO LEAD TO STRONGER DEFORMATION PRECIP REGION.
HEADLINES...GIVEN THIS SYSTEM WILL BE AFFECTING THE AREA ON A MONDAY
WHEN THERE IS LOT OF TRAVEL WITH WORK/SCHOOL/ETC AND SINCE THIS
SYSTEM HAS POTENTIAL TO BE HIGHER IMPACT DUE TO AMOUNT OF MOISTURE
AVAILABLE...THINK GOING WITH A WATCH RIGHT NOW IS A GOOD IDEA. MAIN
ISSUE FOR ALGER AND DELTA COUNTY EASTWARD IS THE INITIAL ICE THREAT
LATER SUNDAY NIGHT INTO MONDAY MORNING. A MIXED BAG OF ICE AND SNOW
AND SOME SLEET IS MAIN ISSUE FOR AREAS OVR CNTRL UPR MI...BASICALLY
MARQUETTE AND DICKINSON/MENOMINEE COUNTIES. FARTHER WEST...IT WOULD
BE GENERALLY A SNOW EVENT. ONLY PLACE WHERE WINTER STORM WATCH WILL
NOT BE ISSUED IS FAR WEST CWA AS MODELS ARE VERY INSISTENT IN SHOWING
THEM BEING MISSED BY INITIAL WARM AIR ADVECTION PRECIPITATION LATE
SUNDAY NIGHT/MONDAY MORNING AND GENERALLY KEEPING THE PRIMARY
DEFORMATION AXIS TO THE EAST OF THOSE AREAS ON MONDAY AFTN/MONDAY
EVENING. WATCHES WILL RUN FM LATE SUNDAY NIGHT THROUGH MONDAY
EVENING FOR MARQUETTE AND DICKINSON COUNTIES WESTWARD BUT WILL KEEP
ENDING TIME SHORTER FARTHER EAST AS MOST PTYPE BY AFTN WILL BE
RAIN/DRIZZLE AND SNOW SHOULD NOT BE SIGNIFICANT...ESPECIALLY IN FAR
EAST TOWARD KERY.
LK EFFECT...POSSIBLY ENHANCED BY DEPARTING SYSTEM WILL TARGET NW
FLOW AREAS LATER MONDAY NIGHT INTO TUESDAY MORNING. GUSTY NW WINDS
WILL LEAD TO BLSN ISSUES AS WELL. WILL GO AHEAD AND RUN WATCHES
THROUGH 12Z WHERE LK EFFECT/BLSN WILL BE HAZARD LATER MONDAY NIGHT.
COORD WITH DLH...GRB...APX AND ALSO HPC ON THIS SYSTEM.
FOR THE EXTENDED /TUESDAY NIGHT THROUGH SATURDAY/...
A SLIGHTLY AMPLIFIED FLOW WITH A BROAD EASTERLY TROUGH AND WEAK
WESTERN RIDGE WILL DEVELOP AND LEAD TO A GENERALLY SUSTAINED WNW/NW
FLOW OVER THE UPPER GREAT LAKES THROUGH MOST OF THE PERIOD. A SERIES
OF SHORTWAVE TROUGHS AND RIDGES WILL PROGRESS ALONG THE WESTERN SIDE
OF THE EASTERN TROUGH AND ALLOW FOR PERSISTENT BUT SMALL PRECIP
CHANCES. HOWEVER...THERE IS DISAGREEMENT IN THE GUIDANCE WITH THE
TIMING OF EACH OF THESE PULSES.
CAA ON THE BACKSIDE OF MONDAYS DEPARTING LOW WILL CEASE TUESDAY
EVENING AS SFC/850MB WINDS BACK TO THE WEST WITH THE PASSAGE OF A
SHARP MID LEVEL RIDGE. SOME LES WILL REMAIN EARLY IN THE EVENING
ACROSS EASTERN PARTS OF THE CWA...AND THROUGHOUT THE EVENING IN THE
KEWEENAW PENINSULA. THERE WILL BE A BRIEF BREAK AFTER THE RIDGE
PASSES BEFORE THE FIRST IMPULSE DIGS SOUTHEAST OUT OF SOUTH CENTRAL
CANADA WEDNESDAY NIGHT THROUGH THURSDAY. THE GFS AND ECMWF WERE IN
DECENT AGREEMENT WITH THE STRENGTH OF THIS WAVE...BUT THE 12Z GFS
HAS TRENDED STRONGER. AT THE SAME TIME...THE GEM HAS NEARLY ZONAL
FLOW WEDNESDAY BEFORE DEVELOPING A WEAK SHORTWAVE THURSDAY
AFTERNOON. ALL THREE MODELS DO KEEPS MUCH OF THE PRECIPITATION OVER
LAKE SUPERIOR AND THE EASTERN HALF OF THE CWA...SO WILL KEEP CHANCES
IN THE FORECAST FOR WEDNESDAY NIGHT. ONLY A VERY SHORT PERIOD OF
LES...6 TO 12 HOURS...IS POSSIBLE FOR WNW FAVORED WIND BELTS
THURSDAY AS BOTH THE GFS AND ECMWF ARE VERY AGGRESSIVE IN BRINGING
DRY AIR AND A SHARP LOW LEVEL RIDGE ACROSS LAKE SUPERIOR THURSDAY
EVENING. EVEN MORE...RAPIDLY LOWERING INVERSION HEIGHTS TO BELOW
3KFT AND TEMPERATURES BELOW THE INVERSION GENERALLY >-12C WILL LOWER
GOOD LES CHANCES.
MORE DISAGREEMENT RESIDES WITH THE NEXT WAVE PROGGED TO PASS TO THE
NORTH OF THE CWA ON FRIDAY. THE 00Z ECMWF SHOWS AN OPEN WAVE AT
500MB OVER WESTERN ONTARIO 18Z FRIDAY...WHEREAS THE GFS HAS A CLOSED
500MB LOW OVER NORTHERN MANITOBA. THE GFS HAS BEEN RATHER CONSISTENT
WITH THIS FEATURE FOR THE LAST DAY WHILE THE ECMWF PULLED THE TROUGH
FURTHER SOUTH. ATTM...THE GFS SEEMS TO BE THE BETTER CHOICE...THOUGH
BOTH HAVE A COLD FRONT MOVING ACROSS CWA DURING THE DAY FRIDAY. AS
THIS OCCURS...THE SURFACE LOW WILL BE TRACKING JUST AHEAD OF THE
MIDLEVEL LOW ALONG THE SOUTHWEST SHORE OF HUDSON BAY. NEAR THE CWA
THE FORCING WILL BE PURELY FRONTAL...WITH THE STRONGEST BAND OF
FRONTOGENESIS NORTH OF LAKE SUPERIOR BETWEEN 500 AND 700MB.
THERE IS ALSO CONCERN ABOUT THE LACK OF MOISTURE WITH THIS FRONTAL
PASSAGE AS AIR AHEAD OF THE FRONT WILL BE PULLED FROM DRY
CONTINENTAL AIR IN THE LEE OF THE NORTHERN ROCKIES.
AIR BEHIND THE COLD FRONT ON FRIDAY WILL BE OF WARMER PACIFIC
ORIGIN...WITH INVERSION HEIGHTS DROPPING INTO THE EVENING. NW FLOW
LES WILL STILL BE A POSSIBILITY...BUT WILL BE GREATLY SUPPRESSED BY
LOW INVERSIONS AND HIGH 850/925MB TEMPERATURES. AIR OF MORE ARCTIC
ORIGIN COMES IN BEHIND A SECONDARY COLD FRONT ON SATURDAY
MORNING...THOUGH MOISTURE IS LACKING WITH THIS FRONT AS WELL. WILL
STAY GENERALLY DRY IN TERMS ON POTENTIAL FRONTAL AND LES PRECIP
EXCEPT ALONG THE KEWEENAW PENINSULA.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
EXPECT VFR TO GIVE WAY TO MVFR CIGS AS A STRONG LOW LEVEL JET
ADVECTS ABUNDANT LOW LEVEL MOISTURE AND LOW CLOUDS INTO UPPER MI
OVERNIGHT THROUGH THE MORNING. DOWNSLOPING WIND COMPONENT AT IWD/CMX
MAY BREAK UP SOME OF THE CLOUDS TIL LATE IN THE NIGHT OR THE MORNING
HRS. EXPECT A BETTER CHANCE OF MVFR CIGS IMPACTING KSAW WITH MORE OF
AN UPSLOPE WIND COMPONENT. BY LATER IN THE AFTERNOON...IFR CIGS ARE
EXPECTED AT KSAW WITH SOME -FZDZ ALSO DEVELOPING DURING THE EVENING
AS STRONG MOISTURE ADVECTION CONTINUES.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
OPTED TO UPGRADE GALE WATCH TO A WARNING OVER THE E PART OF LK SUP
FOR LATE TONIGHT THRU SUN WITH STRENGTHENING SLY FLOW UNDER
SHARPENING PRES GRADIENT BETWEEN DEPARTING HI PRES RIDGE TO THE E
AND DEVELOPING LO IN THE PLAINS. A NNW GALE IS LOOKING MORE LIKELY
FOR MON NIGHT/TUE AS DEEPENING LO PRES TRACKING JUST TO THE E MOVES
INTO SE CANADA. THE WINDS WILL DIMINISH BY TUE NIGHT WITH APPROACH
OF HI PRES RIDGE. ALTHOUGH ANOTHER LO PRES MAY IMPACT THE LAKE ON
THU...NO GALES APPEAR LIKELY ATTM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT
FOR MIZ001-003-004.
WINTER STORM WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY
NIGHT FOR MIZ005-006-011>014-085.
WINTER STORM WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY
AFTERNOON FOR MIZ007.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST SUNDAY FOR LSZ266-267.
LAKE MICHIGAN...NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
EXTENDED...TK
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1141 PM CST SAT JAN 21 2012
.AVIATION...
A WINTER STORM IS APPROACHING WESTERN NEBRASKA FROM THE WEST
TONIGHT. MID AND HIGH CLOUDS PRESENT WITH VISUAL FLIGHT RULES. SNOW
WILL BEGIN OVER THE NORTHERN NEBRASKA PANHANDLE AFTER MIDNIGHT AND
SPREAD EAST ACROSS NORTHERN NEBRASKA THROUGH THE DAY ON SUNDAY WITH
MVFR CEILINGS AND LIFR VISIBILITIES IN SNOW AND BLOWING SNOW FROM
KIEN TO KVTN TO KONL AND NORTH OF A LINE FROM KAIA TO KLBF. STRONG
NORTHWEST WINDS WILL PICK UP AFTER 2212Z AT 25 TO 35 MPH WITH GUSTS
TO AROUND 50 MPH. STRONGER WINDS ARE EXPECTED FROM KOGA TO KIML AND
ACROSS PORTIONS OF THE SOUTHEAST NEBRASKA PANHANDLE.
&&
.PREV DISCUSSION... /ISSUED 945 PM CST SAT JAN 21 2012/
UPDATE...
UPDATED TO REFLECT CURRENT CONDITIONS. WINDS HAVE FALLEN OFF SOME
CLOUDS HAVE INCREASED AND TEMPERATURES ARE AT OR NEAR OVERNIGHT
LOW. LOWERED TEMPERATURES OVER NORTH CENTRAL ZONES WHERE
TEMPERATURES HAVE FALLEN THE MOST.
PREV DISCUSSION... /ISSUED 249 PM CST SAT JAN 21 2012/
DISCUSSION...
THE RUC CONTINUES TO INDICATE WIND ADVISORY CONDITIONS DEVELOPING
ACROSS NCNTL NEB THIS AFTERNOON AS LOW PRESSURE DEEPENS ACROSS THE
HIGH PLAINS. WIND SPEEDS SHOULD PEAK DURING THE LATE AFTERNOON AND
THEN FALL OFF WITH THE LOSS OF DAYTIME HEATING.
SOUTH WINDS CONTINUE OVERNIGHT AS A STRONG PACIFIC COLD FRONT
APPROACHES THE PLAINS. THIS FRONT WILL SWEEP THROUGH THE FCST AREA
SUNDAY MORNING AND LOW PRESSURE WILL CONSOLIDATE ACROSS THE
MIDWEST. STRONG NORTHWEST WINDS WILL DEVELOP BEHIND THE SFC LOW
ASSOCIATED WITH PACIFIC HIGH PRESSURE. A BLEND OF MAV AND MET
GUIDANCE PRODUCED HIGH END WIND ADVISORY CONDITIONS. DEUEL COUNTY
COULD PERHAPS REACH HIGH WIND CATEGORY BUT THAT IS LIKELY A RESULT
OF WEIGHTING FACTORS ASSOCIATED WITH THE DATA FROM KSNY. THE NAM
INDICATED GUSTS TO 55 MPH BUT ONLY ACROSS A SMALL PART OF CHERRY
COUNTY. WINDS ARE EXPECTED TO STAY UP EAST OF HIGHWAY 83 SUNDAY
EVENING FOR A FEW HOURS AS WRAP AROUND STRATUS PRODUCES A SHALLOW
MIXED LAYER. WIND SPEEDS SHOULD DECLINE BETWEEN 03Z AND 06Z AS THE
SFC LOW WILL PRESUMABLY BE FAR ENOUGH EAST FOR THE WINDS TO RELAX.
ELSEWHERE WINDS SHOULD DROP OFF QUICKLY AS A CLEARING LINE MOVES
EAST TO NEAR HIGHWAY 83 BY 00Z MONDAY.
A BLEND OF ECMWF...GEM REGIONAL...NAM AND GFS WAS USED FOR QPF
AMOUNTS WHICH ARE GENERALLY 1/10 OF INCH OR LESS. NOTE THE QPF IS
POST FRONTAL AND THE PTYPE IS SNOW. WITH THE H700MB LOW TRACKING
THROUGH THE NRN PLAINS...SNOW SHOWERS WOULD APPEAR TO BE THE
DOMINANT STORM MODE BUT WE MAY BE DEALING WITH A MIXED MODE AT TIMES.
THE NAM AND GFS ALSO KEEP THE FCST AREA MOSTLY DRY SO POPS ARE CHC
CATEGORY. HPC FAVORED THE GEM MODEL AND THE UKMET. THE ECMWF
APPEARED TO BE THE WETTER SOLN. THE GEM REGIONAL DEVELOPS A WEDGE
OF WARP AROUND QPF ACROSS THE ERN ZONES AMOUNTING TO 1/3 OF AN
INCH. GIVEN THE STRONG WINDS...SIGNIFICANT BLOWING SNOW WOULD
DEVELOP IF THAT WERE TO VERIFY.
HIGH PRESSURE SETTLES OVER THE FCST AREA MONDAY MORNING THROUGH TUESDAY.
A SPLIT IN THE WESTERLIES DEVELOPS SENDING A LARGE UPPER LEVEL CUTOFF
LOW THROUGH THE SRN PLAINS TUESDAY THROUGH FRIDAY. THIS SYSTEM
WILL HAVE LITTLE OR NO EFFECT ON THE SENSIBLE WEATHER ACROSS THE FCST
AREA EXCEPT TO HOLD PACIFIC HIGH PRESSURE IN PLACE. DEEP LOW PRESSURE
CIRCULATING THROUGH CNTL AND SRN CANADA WILL ALSO DRAW PACIFIC
HIGH PRESSURE THROUGH THE CNTL PLAINS WEDNESDAY AND THURSDAY
BEFORE ANOTHER STRONG PACIFIC COLD FRONT DROPS THROUGH THURSDAY
NIGHT OR FRIDAY.
THE FCST IS DRY MONDAY THROUGH SUNDAY. THE GFS IS AMPLIFYING A
DISTURBANCE THRU THE FCST AREA SATURDAY BUT IT APPEARS TO BE TOO
FAST. THE ECMWF HOLDS THAT FEATURE OFFSHORE IN THE PACIFIC.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY
FROM 6 AM CST /5 AM MST/ TO 6 PM CST /5 PM MST/SUNDAY FOR
NEZ004-005-022>025-035>037-056>059-069>071-094.
WIND ADVISORY FROM 9 AM TO 9 PM CST SUNDAY FOR NEZ006>010-
026>029-038.
&&
$$
SHORT TERM/EXTENDED...POWER/CDC
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1250 AM EST SUN JAN 22 2012
.SYNOPSIS...
A COLD FRONT WILL SWEEP ACROSS THE AREA TONIGHT. COOL AND MOIST
CONDITIONS WILL PREVAIL TODAY AS HIGH PRESSURE WEDGES IN FROM THE
NORTH. A WARM FRONT WILL LIFT NORTH ACROSS THE REGION MONDAY. A COLD
FRONT IS EXPECTED TO CROSS THE AREA MONDAY NIGHT. HIGH PRESSURE WILL
FOLLOW TUESDAY THROUGH MID WEEK...WITH A FRONTAL SYSTEM APPROACHING
FROM THE WEST LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 AM SUNDAY...PATCHY LIGHT RAIN AND DRIZZLE EXPECTED
OVERNIGHT AS A COLD FRONTAL PASSAGE WORKS SOUTH. THE FRONTAL
INVERSION WILL RESULT IN A STRATUS DECK BELOW 1000 FEET INTO EARLY
SUNDAY. N-NE SFC WINDS WILL INCREASE TO 10 MPH WITH A FEW GUSTS OF
20 MPH. THIS LOW LEVEL MIXING WILL KEEP ANY FOG FROM BECOMING
WIDESPREAD THOUGH DRIZZLE AND MIST CAN BE ANTICIPATED. TEMPS WILL
DROP INTO THE 40S AREA WIDE BY DAYBREAK.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 PM SATURDAY...COOL...CLOUDY AND MOIST DAY IN STORE FOR
SUNDAY AS A SHORT-LIVED COLD AIR DAMMING SITUATION SETS UP. STEADY
NE FLOW AT THE SURFACE AND EXTENSIVE CLOUD COVER WILL KEEP
AFTERNOON TEMPERATURES A DEGREE OR SO EITHER SIDE OF 50 MOST
LOCATIONS. AS IS TYPICAL FOR THIS TYPE OF PATTERN...EXPECT PATCHY
DRIZZLE OR LIGHT RAIN TO MAKE APPEARANCES AT TIMES...WITH MINIMAL
QPF DUE TO WEAK FORCING AND SHALLOW NATURE OF MOISTURE. THERE WILL
BE A LIMITED DIURNAL RANGE OF TEMPERATURES...WITH LOWS MAINLY IN
THE 40S OVERNIGHT.
WEDGE PATTERN WILL ERODE EARLY ON MONDAY AS A COLD FRONT AND
ASSOCIATED UPPER TROUGH APPROACH FROM THE WEST. FLOW WILL TURN TO
THE SOUTH AND THEN SW MONDAY AFTERNOON...ALLOWING FOR A BIG WARM
UP FROM THE PREVIOUS DAY. EXPECT HIGHS IN THE UPPER 60S TO AROUND
70...ABOUT 20 DEGREES HIGHER THAN ON SUNDAY. FRONT WILL MOVE
ACROSS THE EASTERN CAROLINAS MONDAY EVENING AND OVERNIGHT AND WILL
BE OFFSHORE BY AROUND DAYBREAK ON TUESDAY. MOISTURE WILL BE
LIMITED WITH THIS SYSTEM AND BEST UPPER SUPPORT WILL PASS WELL TO
THE NORTH...SO EXPECT ONLY ISOLATED TO SCATTERED CONVECTION TO
ACCOMPANY FROPA. NOT MUCH IN THE WAY OF COLD ADVECTION WITH THIS
FRONT...SO EXPECT LOWS WILL RANGE FROM THE MID 40S INLAND TO
AROUND 50 AT THE COAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 2:30 PM SATURDAY...MAIN FEATURE FOR THE EXTENDED CONTINUES
TO BE THE CUTOFF MEANDERING ABOUT THE SOUTHWEST AND WHEN IT GETS
KICKED OUT. THE LATEST OPERATIONAL RUN OF THE GFS HAS TRENDED MUCH
SLOWER WHILE PREVIOUS RUNS MAINTAINED MORE OF A ZONAL FLOW. HPC
CONTINUES TO FAVOR THE ECMWF SUITE OF PRODUCTS BASED ON MORE
CONSISTENCY. THESE ARE A BIT SLOWER WITH THE SYSTEM BUT OVERALL
ARE SIMILAR TO THIS TIME YESTERDAY. THE ONLY FORECAST CHANGES WITH
THIS PACKAGE WERE TO DELAY THE POPS SLIGHTLY MAINTAINING THE SAME
STRATEGY AS YESTERDAY WITH INCREASING VALUES FROM LATE THURSDAY
THROUGH THE NEW DAY SATURDAY. ONLY MINOR TWEAKS TO TEMPERATURES
WITH A SLIGHT INCREASE ACROSS THE BOARD TO MATCH HPC NUMBERS AND
ADJACENT OFFICES.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...POST FRONTAL IFR STRATUS EXPECTED MAJORITY OF THE 6Z TAF
CYCLE. THERE MAY BE A BRIEF PERIOD OF IFR VISIBILITIES INTO THE
PRE-DAWN HOURS THIS MORNING. ALONG LEADING EDGE OF THE COLD AIR
ADVECTION EXPECT GUSTY N UP TO 18 KNOTS. TRANSITIONED TO MVFR CIGS
AROUND 18Z BUT LOWERING TO IFR AFTER NIGHTFALL IN MOIST NE FLOW.
EXTENDED OUTLOOK...IFR WILL PERSIST THROUGH MONDAY MORNING. VFR TO
DEVELOP MONDAY LATE WITH A SLIGHT CHANCE OF SHOWERS AS A WARM FRONT
WORKS NORTH. LOW CONFIDENCE FOR MORNING FOG WEDNESDAY AND THURSDAY
MORNINGS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM SATURDAY...SMALL CRAFT EXERCISE CAUTION IS IN EFFECT.
THE COLD FRONT LIES JUST ON THE NORTHERN DOORSTEPS OF THE ILM CWA
PER LATEST MSAS. HRRR HOURLY WIND FORECAST HIGHLIGHTS THE COLD
FRONTAL PASSAGE TO OCCUR BETWEEN 10 PM TONIGHT AND 3 AM SUNDAY.
SFC WINDS AHEAD OF THE CF...HAVE ALREADY BEGUN TO VEER FROM SW TO W
FROM CAPE FEAR NORTHWARD. DURING THE TRANSITIONING PHASE DURING THE
COLD FRONTS PASSAGE...SPEEDS COULD DROP TO 10-15 KT. SFC PG TO
TIGHTEN QUICKLY AFTER THE CFP...AND WILL RESULT IN 15 TO 20 KT
SPEEDS WITH A FEW GUSTS UP TO 25 KT. THE SCEC MAY NEED TO BE
EXPANDED INTO SUNDAY DAYLIGHT HRS IF THE SFC PG REMAINS TIGHTENED
FROM THE 1030+ HIGH RIDGING SOUTHWARD. THREE TO 5 FT WIND DRIVEN
WAVES WILL DOMINATE THE SIGNIFICANT SEAS ACROSS THE COASTAL
WATERS...WITH PERIODS AVERAGING 5 TO 7 SECONDS. CAN NOT RULE OUT AN
ISOLATED 6 FOOTER ACROSS THE OUTER WATERS VICINITY OF FRYING PAN
SHOALS BUT NOT ENOUGH OCCURRENCE TO PLACE 6 FOOTERS IN SIG SEAS.
SEAS WILL BE ADVERTIZED IN THE 3-5 FT RANGE THRUOUT OVERNIGHT. WITH
A DIFFERENT FETCH DIRECTION AND LENGTH AFTER FROPA...SEA HEIGHTS
WILL NEED TO BE ADJUSTED. PATCHY LIGHT RAIN OR DRIZZLE WILL DOMINATE
THE PCPN THREAT OVERNIGHT. LOW STRATUS CLOUD DECK MAY LIMIT VSBYS TO
WHERE GPS AND DEPTH FINDERS ARE UTILIZED FOR THE NEAR SHORE WATERS
AND THE INTRA-COASTAL WATERWAY.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 2:30 PM SATURDAY...NELY FLOW OVER THE WATERS ON SUNDAY WILL
TURN SWLY ON MONDAY AS A COLD FRONT APPROACHES FROM THE WEST.
WINDS WILL RANGE FROM 15 TO 20 KTS EARLY ON SUNDAY BEFORE BECOMING
LIGHT AND VEERING TO THE SE OVERNIGHT WITH THE APPROACH OF THE
COLD FRONT. WINDS WILL PICK UP AGAIN MONDAY AFTERNOON BACK IN THE
15 TO 20 KT RANGE FROM THE SW. COLD FRONT MAY MOVE OFFSHORE BY
AROUND DAYBREAK ON TUESDAY. SEAS WILL RANGE FROM 3 TO 5 FT FOR
MUCH OF THE PERIOD.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 2:30 PM SATURDAY...WESTERLY FLOW INITIALLY IN THE WAKE OF THE
COLD FRONT. A SECONDARY PUSH OCCURS LATE TUESDAY INTO WEDNESDAY
WHICH WILL TURN WINDS TO THE NORTHEAST. FINALLY RETURN FLOW SETS UP
THURSDAY AS A SYSTEM TAKES SHAPE WELL TO THE SOUTHWEST. OVERALL WIND
SPEEDS SHOULD REMAIN MODEST WITH THE POSSIBLE EXCEPTION OF LATE INT
HE PERIOD WHEN THE SOUTHWEST FLOW SURGES. SEAS WILL REFLECT THE
MODEST WINDS WITH AROUND TWO FEET FOR TUESDAY AND WEDNESDAY
INCREASING SLIGHTLY THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DOUG/MICHAELJAY
SHORT TERM...RICHARD
LONG TERM...STEPHEN
AVIATION...MICHAELJAY
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1140 PM CST SAT JAN 21 2012
.UPDATE...
AVIATION DISCUSSION UPDATED FOR 06Z TAF ISSUANCE.
WITH NEW 00Z NAM AND LAST COUPLE RUNS OF THE HRRR POINTING TOWARD
MORE PCPN FOR SOUTHERN COUNTIES...DECIDED TO ADD THEM TO THE
WINTER WEATHER ADVISORY. LOOKS LIKE MORE SNOW VS EARLIER
PREDICTIONS...AND BLOWING SNOW COULD BE AN ISSUE ON SUNDAY. UPDATES
ALREADY ISSUED.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
BLOWING SNOW CONTINUES ACROSS A LARGE PORTION OF THE CWA THIS
AFTERNOON AS GUSTY SOUTH WINDS OF 20 TO 35 MPH ARE BEING OBSERVED.
AREAS OF LIGHT SNOW CONTINUE ACROSS THE EASTERN CWA AS WELL SO
WILL KEEP MENTION OF THESE ELEMENTS IN GRIDS THROUGH LATE
AFTERNOON AND INTO THE EVENING. BREEZY SOUTH WINDS PERSIST OVER
THE EASTERN COUNTIES FOR A GOOD CHUNK OF THE NIGHT SO OPTED TO
KEEP MENTION OF BLOWING SNOW IN THE GRIDS.
FOCUS REMAINS ON THE STORM SYSTEM IMPACTING THE AREA TONIGHT
THROUGH TOMORROW NIGHT. STILL APPEARS THREAT IS THERE FOR FREEZING
RAIN AND SLEET AHEAD OF THE LOW OVERNIGHT...BUT MODELS BACKING OFF
A BIT AND KEEPING THINGS FURTHER NORTH. DO NOT EXPECT MAJOR ICE
ACCUMS BUT ANYWHERE THAT DOES SEE FREEZING RAIN MAY RECEIVE A FEW
HUNDREDTHS ICE ACCUMULATION. MODELS BEGINNING TO LATCH ONTO A
SOLUTION NOW WHICH HIGHLIGHTS THE WRAP AROUND DEFORMATION SNOWFALL
ON SUNDAY. LOOKS LIKE MUCH OF THE AREA WILL RECEIVE ABOUT 2 TO 4
INCHES OF SNOWFALL WITH A FEW HIGHER AMOUNTS POSSIBLE. MODELS
TRYING TO STRENGTHEN THINGS A BIT IN REGARDS TO SNOWFALL TOMORROW.
A DECENT LITTLE SYSTEM SLIDING THROUGH IT APPEARS. NORTHWEST WINDS
WILL BEGIN TO INCREASE SUNDAY MORNING ACROSS WESTERN AND CENTRAL
SOUTH DAKOTA...THEN FINALLY ACROSS THE EASTERN CWA BY SUNDAY
AFTERNOON AND EVENING. THIS WILL CREATE AREAS OF BLOWING SNOW WITH
REDUCED VSBYS. WILL LET THE WINTER WX ADVISORY RIDE AS IS FOR NOW
AND MID SHIFT MAY NEED TO CONSIDER ADDING THE SOUTHWEST CWA.
APPEARS AMOUNTS WILL BE LIGHTER IN THIS AREA THOUGH. WINDS MAY
REACH ADVISORY CRITERIA TOMORROW AFTERNOON ACROSS THE WESTERN CWA
SO ANOTHER THING TO CONSIDER. THE ADVISORY WINDS CAN BE INCLUDED
IN THE CURRENT WSW...BUT IF THE SOUTHWEST CWA IS LEFT OUT OF THE
WSW...ONE MAY CONSIDER THROWING THEM INTO A WIND ADVISORY FOR THE
AFTERNOON TOMORROW AND MENTION BLOWING SNOW ISSUES.
.LONG TERM...TUESDAY THROUGH SATURDAY
THE OPERATIONAL MODELS AND GFS ENSEMBLES SHOW GOOD AGREEMENT
THROUGH THE LONG TERM. AN UPPER LEVEL HIGH PRESSURE AREA WILL BE
SITUATED OFF THE CA COAST WITH FAST WESTERLY FLOW COMING OFF THE
PACIFIC ACROSS THE NORTHWEST AND ACROSS OUR REGION. THIS MEANS WE
WILL HAVE ABOVE TO MUCH ABOVE NORMAL TEMPERATURES AGAIN ACROSS THE
CWA FOR THE LONG TERM. THE ONLY THING THAT WILL AFFECT THE WARM UP
THIS TIME AROUND WILL BE THE EXTENSIVE SNOW COVER IN PLACE ACROSS
THE REGION. THUS...TEMPERATURES MAY NOT BE QUITE AS WARM.
OTHERWISE...IT IS EXPECTED TO BE DRY WITH SEVERAL FAST MOVING
SHORT WAVES MOVING ACROSS THE REGION WITH LITTLE MOISTURE
AVAILABLE.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
AT KABR/KATY A MIX OF MVFR/VFR CIGS WILL OCCUR THROUGH MOST OF
THE NIGHT. VSBYS WILL FAVOR VFR/MVFR THROUGH THE NIGHT. MOST OF
THE PRECIPITATION AT THESE TWO TAF SITES MAY HOLD OFF TILL LATE NIGHT.
AT KPIR/KMBG VFR CIGS AND VSBYS SHOULD GRADUALLY LOWER TOWARD
IFR/MVFR OVERNIGHT AS PCPN GRADUALLY SPREADS TOWARD THE MO RVR
VALLEY. A MIX OF FREEZING RAIN AND/OR SLEET IS EXPECTED
OVERNIGHT...TURNING TO ALL SNOW ON SUNDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ SUNDAY
NIGHT FOR BROWN-BUFFALO-CAMPBELL-CORSON-DEWEY-EDMUNDS-FAULK-
HAND-HUGHES-HYDE-JONES-LYMAN-MCPHERSON-POTTER-STANLEY-SULLY-
WALWORTH.
WINTER WEATHER ADVISORY FROM 3 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR CLARK-CODINGTON-DAY-DEUEL-GRANT-HAMLIN-MARSHALL-
ROBERTS-SPINK.
MN...WINTER WEATHER ADVISORY FROM 3 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR BIG STONE-TRAVERSE.
&&
$$
UPDATE...TDK
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1016 PM MST SAT JAN 21 2012
.AVIATION...06Z TAFS
AREA OF -RA/-FZRA LIFTING NORTHWARD INTO NW SD. -RA/FZRA WILL
TRANSITION TO SNOW OVER THE NEXT FEW HOURS. WIDESPREAD SNOW
EXPECTED OVERNIGHT ACROSS NORTHEAST WYOMING/NORTHERN BLACK
HILLS/NORTHWEST SOUTH DAKOTA....WITH SNOW SPREADING INTO CENTRAL
SOUTH DAKOTA DURING THE DAY SUNDAY. AS A COLD FRONT SWEEPS
THROUGH THE AREA TONIGHT...VERY STRONG NORTHWEST WINDS WILL DEVELOP ON
THE PLAINS NORTH AND EAST OF THE BLACK HILLS...WITH 50-55KT GUSTS
LIKELY AT KRAP. COMBINATION OF WIND AND SNOW WILL RESULT IN
WIDESPREAD IFR/LIFR VSBY. CONDITIONS WILL SLOWLY FROM WEST TO EAST
DURING THE DAY SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 736 PM MST SAT JAN 21 2012/
DISCUSSION...CURRENT SURFACE MAP SHOWS ELONGATED AREA OF LOW
PRESSURE ACROSS EASTERN MONTANA INTO NORTHEAST COLORADO. AREA OF
LIGHT RAIN/FREEZING RAIN SPREADING NORTHWARD EAST AND NORTH OF THE
BLACK HILLS. SURFACE TEMPERATURES ACROSS NORTHWEST SOUTH DAKOTA
REMAIN BELOW FREEZING. SEVERAL FORECAST CHALLENGES OVERNIGHT.
00Z KUNR/KBIS SOUNDINGS AND 00Z RUC SOUNDINGS SUPPORT MAINLY
FREEZING RAIN THIS EVENING ACROSS NORTHWEST SOUTH DAKOTA. AS
STRONGER LIFT SPREADS ACROSS THIS AREA AROUND 06Z...SUFFICIENT
COOLING IN THE MID LEVELS WILL ALLOW FOR TRANSITION TO SNOW.
PRECIPITATION HAS BEEN A LITTLE SLOWER TO DEVELOP ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA THIS EVENING. 00Z RUC/NAM
SHOW UPPER LEVEL DIVERGENCE INCREASING THROUGH 06Z WITH DECENT JET
COUPLING. 18Z NAM/GFS AND 00Z RUC STILL MAINTAIN HIGHEST SNOW
AMOUNTS ACROSS NORTHEAST WYOMING/NORTHWEST SOUTH DAKOTA. 00Z NAM
COMING IN...AND SHIFTS HIGHER AMOUNTS INTO SOUTHWEST THROUGH
CENTRAL SOUTH DAKOTA. WILL NOT MAKE SIGNIFICANT CHANGES TO SNOW
AMOUNTS AT THIS TIME.
STRONG WINDS STILL ON TRACK FOR LATE TONIGHT AND SUNDAY. 00Z
NAM/00Z RUC STILL SHOWING 40-50KT BOUNDARY LAYER WINDS ACROSS THE
PLAINS OF WESTERN SOUTH DAKOTA. MOMENTUM TRANSFER ON FORECAST
SOUNDINGS SUGGEST 55KT GUSTS POSSIBLE...ESPECIALLY FOR THE RAPID
CITY AREA.
OVERALL...CURRENT HEADLINES LOOK GOOD. SNOW WILL TAKE A LITTLE BIT
LONGER TO DEVELOP ACROSS THE BLACK HILLS...BUT WILL NOT ADJUST THE
TIMING OF THE WARNING AT THIS TIME.
PREV DISCUSSION... /ISSUED 330 PM MST SAT JAN 21 2012/
DISCUSSION...22Z SURFACE ANALYSIS SHOWS THE WARM FRONT CURRENTLY
EXTENDING FROM SOUTHEASTERN MONTANA TO NORTH OF THE BLACK
HILLS...THEN TOWARD SOUTHEASTERN SOUTH DAKOTA. TEMPERATURES TO THE
NORTH OF THE WARM FRONT ARE STILL IN THE MID 20S...WITH 40S AND
50S SOUTH OF THE FRONT. THE SFC LOW PRESSURE CENTER WILL DROP INTO
SOUTH CENTRAL SOUTH DAKOTA BY 12Z SUNDAY...FOLLOWED BY A COLD
FRONT AND GUSTY WINDS DUE TO THE TIGHT SURFACE PRESSURE GRADIENT.
FOR TONIGHT...A RELATIVELY STRONG UPPER TROUGH WILL CROSS THE AREA
TONIGHT WITH THE 700MB LOW PROGGED TO TRACK FROM JUST NORTH OF THE
BLACK HILLS EASTWARD TONIGHT. ISENTROPIC LIFT AND FRONTOGENESIS
SHOULD PLACE THE BAND OF HEAVIEST SNOW ACROSS CAMPBELL COUNTY IN
NORTHEASTERN WYOMING TO THE NORTHERN BLACK HILLS AND THEN
NORTHEASTWARD ACROSS NORTHWESTERN SOUTH DAKOTA WITH 3-5 INCHES OF
SNOW THROUGH THAT AREA. DUE TO UPSLOPE ENHANCEMENT HAVE PLACED 5 TO
8 INCH SNOW AMOUNTS IN THE FAVORED AREAS OF THE NORTHERN BLACK
HILLS. MODEL SOUNDINGS SHOW A VERY SHALLOW COLD LAYER OVER
NORTHWESTERN SOUTH DAKOTA WHICH WILL LEAD TO THE POSSIBILITY OF
SOME LIGHT FREEZING RAIN THERE TONIGHT. WINDS BEHIND THE COLD
FRONT ARE EXPECTED TO REACH HIGH WIND WARNING CRITERIA IN THE
RAPID CITY AREA AROUND 09Z. AFTER A SLIGHT LULL IN THE MORNING...WINDS
WILL INCREASE TO NEAR WARNING CRITERIA AGAIN ON SUNDAY ACROSS
NORTHWESTERN AND WEST CENTRAL SOUTH DAKOTA AS SUBSIDENCE TAKES
OVER. DUE TO THE STRONG WINDS COMBINED WITH THE EXPECTED SNOWFALL
AND MIXED PRECIP HAVE ISSUED A WINTER STORM WARNING OVER
NORTHWESTERN SOUTH DAKOTA. WINDS WILL BE SOMEWHAT LIGHTER OVER
NORTHEASTERN WYOMING SO A WINTER WEATHER ADVISORY SHOULD SUFFICE
THERE. MESO MODELS SHOW A DOWNSLOPE HOLE IN THE PRECIPITATION OVER
THE RAPID CITY AREA AND THE ADJACENT PLAINS SO HAVE DECIDED TO
ISSUED A HIGH WIND WARNING OVER THOSE AREAS WITH A MENTION OF SOME
SNOW AND BLOWING SNOW.
THE SNOW IS EXPECTED TO TAPER OFF FROM WEST TO EAST ON SUNDAY BUT
THE GUSTY WINDS AND AREAS OF BLOWING SNOW WILL CONTINUE THROUGH THE
DAY SO WILL KEEP THE HIGHLIGHTS GOING THROUGH SUNDAY.
DRY WEATHER ALONG WITH DECREASING WIND AND CLOUDS EXPECTED ON
SUNDAY NIGHT WITH LOWS IN THE TEENS.
AN AREA OF HIGH PRESSURE WILL MOVE EAST OF THE REGION ON MONDAY...
WITH MOSTLY SUNNY SKIES AND HIGHS MOSTLY IN THE 30S. CLOUDS WILL
INCREASE FROM THE WEST LATE IN THE DAY AND INTO MONDAY NIGHT AS A
WEAK DISTURBANCE CROSSES MT AND WY. WILL KEEP SLIGHT CHANCE FOR SNOW
MONDAY NIGHT INTO EARLY TUESDAY FOR NORTHEASTERN WY AND THE BLACK
HILLS.
EXTENDED...MILDER WEATHER WILL CONTINUE ACROSS THE AREA FOR THE
MIDDLE AND LATTER PART OF NEXT WEEK AS WESTERLY FLOW ALOFT REMAINS
OVER THE REGION. TEMPERATURES WILL GENERALLY REMAIN ABOVE AVERAGE
THROUGH THE PERIOD...WITH THE WARMEST DAYS EXPECTED TO BE WEDNESDAY
AND THURSDAY. A SERIES OF WEAK DISTURBANCES WILL PASS THROUGH THE
REGION DURING THIS TIME...BRINGING SOME CLOUDINESS...CHANCES FOR
SHOWERS...AND OCCASIONAL GUSTY WINDS...MAINLY TO WESTERN PORTIONS OF
THE AREA. TIMING OF THESE WAVES IS STILL RATHER UNCERTAIN IN THIS
FLOW...BUT HAVE KEPT SLIGHT CHANCES FOR WEDNESDAY AND THURSDAY INTO
THURSDAY NIGHT FOR NORTHERN AND WESTERN PORTIONS OF THE CWA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM MST SUNDAY FOR BUTTE-CENTRAL
BLACK HILLS-HARDING-NORTHERN BLACK HILLS-NORTHERN FOOT
HILLS-NORTHERN MEADE CO PLAINS-PERKINS-SOUTHERN MEADE CO
PLAINS-STURGIS/PIEDMONT FOOT HILLS.
WIND ADVISORY UNTIL 6 PM MST /7 PM CST/ SUNDAY FOR BENNETT-
MELLETTE-TODD-TRIPP.
WINTER WEATHER ADVISORY UNTIL 6 PM MST SUNDAY FOR HAAKON-JACKSON-
SHANNON.
HIGH WIND WARNING UNTIL 6 PM MST SUNDAY FOR CUSTER CO PLAINS-
HERMOSA FOOT HILLS-PENNINGTON CO PLAINS-RAPID CITY.
WINTER WEATHER ADVISORY UNTIL 6 PM MST SUNDAY FOR ZIEBACH.
WY...WINTER STORM WARNING UNTIL 6 PM MST SUNDAY FOR NORTHEASTERN
CROOK-WYOMING BLACK HILLS.
WINTER WEATHER ADVISORY UNTIL NOON MST SUNDAY FOR NORTHERN
CAMPBELL-SOUTHERN CAMPBELL-WESTERN CROOK-WESTON.
&&
$$
SHORT TERM...07
LONG TERM....WFO UNR
AVIATION...07
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
230 AM CST SUN JAN 22 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
230 AM CST SUN JAN 22 2012
FREEZING DRIZZLE IS THE FORECAST FOCUS TODAY/TONIGHT...WITH A NEED
FOR HEADLINES.
LATEST WATERVAPOR IMAGERY POINTED TO AN UPPER LEVEL TROUGH/SHORTWAVE
ENERGY MOVING EAST OUT OF THE DESERT SOUTHWEST. THE TROUGH WILL
TRACK OVER THE PLAINS...THEN CURVE NORTHEAST ACROSS THE GREAT
LAKES FOR TONIGHT/MON MORNING. THIS HAS BEEN A CONSISTENT SIGNAL IN
THE MODELS...ALTHOUGH THE TIMING AND POSITION OF THE SYSTEM HAS NOT.
HOWEVER...22.00Z RUNS STARTING TO SHOW MORE AGREEMENT WITH THE EC
AND GEM...DRIVING THE SYSTEM/S SFC LOW TO LOT BY 12Z SUN...WHILE THE
GFS IS SHIFTED A BIT FARTHER NORTH INTO SOUTHCENTRAL WI. THE NAM HAS
BEEN THE ODD MODEL OUT...BUT ITS RECENT RUN IS STARTING TO TREND
TOWARD THE SLOWER SOLUTIONS...ALTHOUGH STILL OVER NORTHERN WI BY 12Z
MON. GIVEN THE CONSISTENCY OF THE EC...WILL CONTINUE TO FAVOR THIS
SOLUTION...BLENDING IN THE GEM/GFS.
MAIN CONCERN WITH THIS SYSTEM IS THE POTENTIAL FOR FREEZING DRIZZLE.
NORTHWEST-SOUTHEAST X-SECTIONS AND BUFKIT SOUNDINGS CONTINUE TO SHOW
ONLY A LOW SATURATION IN PLACE INTO THIS EVENING...GENERALLY BELOW
850 MB. GOOD LOW LEVEL WARMING IN THE 925-850 MB LAYER ALONG WITH
ISENTROPIC UPGLIDE ALONG THE 275-290 K SFCS. RUC13 BUFKIT SOUNDINGS
SHOW A DECENT AMOUNT OF UPWARD OMEGA IN THE SATURATED LAYER THROUGH
THIS EVENING WHILE THE X-SECTIONS VIA THE GFS40 AND RUC13 POINT TO
SOME FRONTOGENETIC LIFT ALONG THE TOP OF THE SATURATED LAYER. ALL
MODELS SHOW SOME LIGHT QPF DEVELOPING BY AT LEAST THE AFTERNOON FOR
THE FORECAST AREA....PERSISTING INTO THE EVENING AND THEN INCREASING
TONIGHT AS THE SHORTWAVE TROUGH/SFC LOW MOVES IN. BEFORE THAT
THOUGH...THE EXPECTED LOW CLOUDS WILL LACK ANY ICE...THUS MAKING ANY
PCPN THE LIFT CAN SQUEEZE OUT OF THEM LIQUID...AND EITHER FREEZING
DRIZZLE OR DRIZZLE...SFC TEMP DEPENDENT. THAT SAID...WITH TEMPS
EXPECTED TO WARM INTO THE EARLY EVENING THANKS TO THE STRONG WARM
AIR ADVECTIVE SIGNAL...GROUND TEMPS WILL LIKELY STILL STAY BELOW
FREEZING DUE TO THE SEVERAL DAYS OF COLD CONDITIONS. SO...FREEZING
COULD STILL RESULT ON UNTREATED ROADS AND OTHER EXPOSED SFCS EVEN IF
THE AIR TEMP RISES ABOVE FREEZING.
WITH ALL THIS IN MIND...FEEL THE THREAT FOR AREAS OF FREEZING
DRIZZLE IS HIGH ENOUGH FOR A FREEZING RAIN ADVISORY TODAY INTO THIS
EVENING. SOUNDINGS AND X-SECTIONS DON/T REALLY DISCRIMINATE TOO MUCH
BETWEEN WHERE THE CHANCES WOULD BE BEST...SO WILL GO WITH THE ENTIRE
FORECAST AREA. THE AFTERNOON INTO EARLY EVENING WOULD APPEAR TO BE
THE MAIN THREAT TIME...BUT CAN/T RULE OUT PERIODS OF FREEZING
DRIZZLE THIS MORNING...SO WILL START IT EARLY.
THE SATURATION DEEPENS OVERNIGHT ENOUGH THAT ICE WOULD BE INTRODUCED
INTO THE CLOUD...AND SNOW BECOMES THE PCPN TYPE. THIS CORRESPONDS
WITH THE APPROACH OF THE UPPER LEVEL TROUGH/SFC LOW...AND BETTER
UPPER LEVEL FORCING. QPF INCREASES IN THE MODELS AS A RESULT...AND
SOME MINOR SNOW ACCUMULATIONS ARE PROBABLE. WHILE ITS BELIEVED THE
EC HAS THE BEST HANDLE ON THIS SYSTEM AT THIS TIME...ITS DEFORMATION
PCPN REGION LIES ON TOP OF ITS SFC LOW. MEANWHILE THE GFS AND GEM IS
DISPLACED A BIT MORE NORTH-WEST OF THE LOW TRACK...AND SEEMS MORE
REASONABLE. WILL TREND THE SNOW CHANCES THIS WAY OVERNIGHT. WILL GO
WITH 1 TO 3 INCHES OF SNOW ACCUMULATION...WITH THE HIGHER AMOUNTS
MORE LIKELY NORTH OF I-94.
SNOW WILL GRADUALLY SHIFT NORTHEAST AS THE LOW PRESSURE SYSTEM
SHIFTS INTO SOUTHEAST CANADA. IT WILL BE A WINDY DAY WITH AN
INCREASING SFC PRESSURE GRADIENT POST THE LOW. IN ADDITION...COLD
AIR ADVECTION WILL RESULT IN STEADY OF SLOWLY FALLING TEMPERATURES.
MONDAY/S HIGH WILL LIKELY BE DURING THE EARLY MORNING HOURS.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
230 AM CST SUN JAN 22 2012
FAIRLY ACTIVE NEARLY ZONAL UPPER LEVEL FLOW WILL PERSIST INTO THE
UPCOMING WEEKEND...SPINNING SEVERAL SHORTWAVE TROUGHS ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY. HOWEVER...BOTH THE GFS AND ECMWF
KEEP THE BULK OF ANY ASSOCIATED PCPN ACROSS NORTHERN PORTIONS OF THE
REGION. SO OVERALL...IT LOOKS FAIRLY DRY THROUGH THE PERIOD...WITH
THE BETTER...ALBEIT SMALL SNOW CHANCES...ACROSS THE NORTH.
TEMPERATURES SHOULD BE AT OR ABOVE THE SEASONABLE NORMALS.
&&
.AVIATION...THROUGH 06Z MONDAY
1135 PM CST SAT JAN 21 2012
SUB VFR CONDITIONS AND THE ONSET OF PRECIPITATION CONTINUE TO BE
THE MAIN FOCUS AT THE TAF SITES THROUGH SUNDAY NIGHT. A 1KFT TO
2KFT STRATUS DECK SETTLED IN ACROSS MUCH OF MINNESOTA AND IOWA
WITH THE EASTERN EDGE OF THIS DECK ERODING ACROSS WISCONSIN ALONG
THE MISSISSIPPI RIVER. THIS DRY SLOT SHOULD GET INTO LSE AROUND
630-7Z AND WILL LIKELY PERSIST UNTIL 12Z WHEN LOW LEVEL MOISTURE
RETURN STRENGTHENS AND BRINGS ANOTHER LOW LEVEL CLOUD DECK UP FROM
MISSOURI/ILLINOIS. AT RST...HAVE LOW END MVFR RIGHT NOW WITH
CEILINGS AT 1300FT AND VISIBILITY AT 6SM DUE TO SOME DRIFTING
SNOW.
WHEN CONDITIONS WILL LOWER AND WHEN THE PRECIPITATION STARTS UP IS
THE TOUGHEST PART OF THE FORECAST RIGHT NOW. FOR
PRECIPITATION...THE MAIN TYPE WILL LIKELY BE FREEZING DRIZZLE WITH
SIGNS POINTING TO A LATE MORNING START UP OF THE DRIZZLE WITH THIS
TIMING ALSO COINCIDING WITH CEILINGS AND VISIBILITY DROPPING DOWN
TO IFR OR LOWER. THE ONLY CHANGES THAT WILL COME LATE IN THE
AFTERNOON AND EVENING IS WITH WINDS DIMINISHING OUT OF THE
SOUTHEAST AND A CHANGE OVER TO SNOW AT RST AROUND 4Z WITH
VISIBILITY POSSIBLY DROPPING BELOW A MILE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 AM CST SUN JAN 22 2012
WI...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR WIZ017-029-032>034-041>044-053>055-061.
MN...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR MNZ079-086>088-094>096.
IA...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION..... HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 PM CST SAT JAN 21 2012
.SHORT TERM...UDPATE FOR OVERNIGHT INTO TOMORROW
926 PM CST SAT JAN 21 2012
THE MAIN FOCUS CONTINUES TO BE ON THE FREEZING DRIZZLE THAT LOOKS
PROBABLE VERY LATE TONIGHT INTO TOMORROW AND HOW WIDESPREAD IT
WILL BECOME.
MUCH OF WHAT WAS MENTIONED EARLIER TODAY STILL HOLDS TRUE NOW WITH
THE PAST FEW RUNS OF RUC SOUNDINGS STILL SHOWING SOME FREEZING
DRIZZLE DEVELOPING THROUGH TOMORROW. THE 20.20Z TO 21.01Z RUC
SOUNDINGS SHOW A SATURATED LAYER FROM THE SURFACE UP TO AROUND
900MB TONIGHT THROUGH THE EARLY MORNING HOURS ACROSS MUCH OF THE
REGION WITH A SUBSTANTIAL DRY LAYER LOCATED AT THE TOP OF THIS LOW
LEVEL INVERSION WHICH ENDS AROUND 800MB. OMEGA LOOKS DECENT ENOUGH
IN THE MID LEVELS OVERNIGHT...BUT IT IS JUST WORKING ON DRY AIR AT
THOSE LEVELS. ITS GOING TO TAKE SOME LOW LEVEL FORCING TO START
PRODUCING ANY DRIZZLE AND THAT DOES NOT APPEAR TO COME IN UNTIL
12Z OR SO FROM THE WEST AS THE SURFACE LOW APPROACHES AND
ISENTROPIC LIFT INCREASES ON THE 280K TO 290K SURFACES. ANOTHER
ISSUE IS THAT THESE SOUNDINGS...ALONG WITH THE 22.00Z NAM THAT IS
JUST COMING IN...ALSO SHOW 925MB TEMPERATURES DOWN AROUND -8C TO
-10C ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA THROUGH 18Z
SUNDAY WHICH MAY BE COLD ENOUGH TO PROMOTE ICE DEVELOPMENT.
SO...INSTEAD OF SEEING JUST FREEZING DRIZZLE ACROSS THIS REGION
SUNDAY MORNING...IT COULD BE A MIX OF FREEZING DRIZZLE...SNOW
GRAINS...AND SLEET. 22.00Z MPX SOUNDING BACKS UP THESE -10C LOW
LEVEL TEMPERATURES...BUT CONFIDENCE IS NOT HIGH ENOUGH THAT THESE
WILL STILL BE COLD ENOUGH TO PRODUCE THE ICE/SNOW IN THE MORNING...SO
HAVE LEFT THE FREEZING DRIZZLE AS THE MAIN PRECIPITATION TYPE. DUE
TO THIS UNCERTAINTY...CONFIDENCE IS LOW ENOUGH THAT A FREEZING
RAIN ADVISORY WILL NOT BE ISSUED THIS EVENING FOR SUNDAY.
THE OTHER NEAR TERM CONSIDERATION WITH THE DRIZZLE WAS WITH
WHETHER TO PUSH IT INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA A
LITTLE FASTER OVERNIGHT...MAINLY AROUND 9-12Z FROM FLOYD COUNTY
IOWA NORTH TO DODGE COUNTY MINNESOTA. THIS IS BASED ON THE 21.01Z
RUC SOUNDINGS FROM MCW SHOWING SOME LOW LEVEL OMEGA GETTING IN
DURING THAT TIME FRAME. STILL THINK THAT THE BETTER FORCING WILL
COME IN LATER...SO NO UPDATES WERE MADE IN THIS AREA.
ONE LAST CONSIDERATION WAS WHETHER TO ADD ANY BLOWING SNOW TO THE
FORECAST FOR OVERNIGHT AS WINDS HAVE PICKED UP TO BETWEEN 20-30KTS
ACROSS MUCH OF THE AREA ALONG AND WEST OF THE MISSISSIPPI RIVER.
DESPITE THE POWDERY SNOW THAT FELL YESTERDAY...A FULL DAY OF
COMPACTION AND SUNLIGHT SEEMS TO BE KEEPING MUCH OF THE SNOW IN
PLACE EXCEPT FOR FURTHER WEST ACROSS NORTHWEST IOWA AND SOUTHWEST
MINNESOTA WHERE VISIBILITY IS DOWN BETWEEN 3/4SM AND 2SM. HAVE
MADE SOME CALLS OUT TO SOUTHEAST MINNESOTA AND NORTHEAST IOWA AND
THE COUNTY SHERIFFS ARE REPORTING THAT THEY HAVE NOT HAD ANY
ISSUES WITH BLOWING SNOW...BUT THAT IT IS JUST DRIFTING SNOW
RUNNING OVER THE TOP OF ROADWAYS. THUS...NO BLOWING SNOW WILL BE
ADDED TO THE FORECAST FOR OVERNIGHT.
TEMPERATURES WILL STICK TO RIGHT AROUND 20 DEGREES OVERNIGHT WITH
LOW LEVEL STRATUS FILLING IN FROM THE WEST AND GUSTY SOUTHEAST
WINDS PROMOTING LOW LEVEL MIXING.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
319 PM CST SAT JAN 21 2012
AFTER AN ACTIVE SHORT TERM PERIOD...LONG TERM FORECAST AT LEAST AT
THIS TIME LOOKS FAIRLY BENIGN. IN THE MEAN...ALL MODELS ARE IN
AGREEMENT OF A FAST WEST-NORTHWEST PATTERN FROM THE PACIFIC
NORTHWEST INTO OUR REGION...WHICH MAY BECOME A LITTLE MORE
NORTHWESTERLY ON SATURDAY WITH INDICATIONS OF A SHORTWAVE TROUGH
DIGGING DOWN INTO THE FORECAST AREA. THIS PATTERN WILL SUPPORT A
FLOW OF MILD PACIFIC AIR INTO THE FORECAST AREA...NOTED BY 850MB
TEMPS THAT STRUGGLE TO GET COLDER THAN -6C FOR THE MOST PART UNTIL
SATURDAY. THERE ARE A FEW SHORTWAVE TROUGHS PROGGED TO MOVE THROUGH
THE AREA...ONE TUESDAY NIGHT AND WEDNESDAY...AND ANOTHER ON
THURSDAY. NEITHER OF THESE FEATURES PRODUCE MUCH QPF IN MODEL
OUTPUT...PRIMARILY BECAUSE THEY DO NOT HAVE MUCH MOISTURE TO WORK
WITH. THE SYSTEM IN THE SHORT TERM PERIOD PRETTY MUCH SHUNTS ALL
MOISTURE SOUTH AND EAST OF THE AREA. THEREFORE...ONLY SOME SLIGHT
CHANCES REMAIN FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
PRECIPITATION TYPE MAY HAVE TO BE WATCHED FOR THIS TIME
PERIOD...GIVEN THE MILDER 850MB TEMPS. WOULD NOT BE SURPRISED TO SEE
EITHER MIXES WITH RAIN...OR WORSE A LOSS OF ICE RESULTING IN
RAIN/FREEZING RAIN VERSUS SNOW. KEPT PRECIPITATION TYPES AS SNOW
SINCE BOTH DETAILS ARE VERY UNCERTAIN AT THIS TIME.
FOR MUCH OF THE LONG TERM PERIOD...FOLLOWED A CONSENSUS BLEND OF
GUIDANCE FOR BOTH TEMPERATURES AND PRECIPITATION THROUGHOUT THE
LONG TERM PERIOD.
&&
.AVIATION...THROUGH 06Z MONDAY
1135 PM CST SAT JAN 21 2012
SUB VFR CONDITIONS AND THE ONSET OF PRECIPITATION CONTINUE TO BE
THE MAIN FOCUS AT THE TAF SITES THROUGH SUNDAY NIGHT. A 1KFT TO
2KFT STRATUS DECK SETTLED IN ACROSS MUCH OF MINNESOTA AND IOWA
WITH THE EASTERN EDGE OF THIS DECK ERODING ACROSS WISCONSIN ALONG
THE MISSISSIPPI RIVER. THIS DRY SLOT SHOULD GET INTO LSE AROUND
630-7Z AND WILL LIKELY PERSIST UNTIL 12Z WHEN LOW LEVEL MOISTURE
RETURN STRENGTHENS AND BRINGS ANOTHER LOW LEVEL CLOUD DECK UP FROM
MISSOURI/ILLINOIS. AT RST...HAVE LOW END MVFR RIGHT NOW WITH
CEILINGS AT 1300FT AND VISIBILITY AT 6SM DUE TO SOME DRIFTING
SNOW.
WHEN CONDITIONS WILL LOWER AND WHEN THE PRECIPITATION STARTS UP IS
THE TOUGHEST PART OF THE FORECAST RIGHT NOW. FOR
PRECIPITATION...THE MAIN TYPE WILL LIKELY BE FREEZING DRIZZLE WITH
SIGNS POINTING TO A LATE MORNING START UP OF THE DRIZZLE WITH THIS
TIMING ALSO COINCIDING WITH CEILINGS AND VISIBILITY DROPPING DOWN
TO IFR OR LOWER. THE ONLY CHANGES THAT WILL COME LATE IN THE
AFTERNOON AND EVENING IS WITH WINDS DIMINISHING OUT OF THE
SOUTHEAST AND A CHANGE OVER TO SNOW AT RST AROUND 4Z WITH
VISIBILITY POSSIBLY DROPPING BELOW A MILE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
319 PM CST SAT JAN 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
601 AM MST SUN JAN 22 2012
.UPDATE...
QUICK UPDATE TO DROP THE SOUTHERN VALLEY HIGHLIGHTS AS SNOWFALL
CONTINUES TO DIMINISH IN COVERAGE AND INTENSITY. BACK EDGE OF
PRECIP GRADUALLY SHIFTING EAST WITH ONLY SCATTERED SHOWERS
EXPECTED ON THE BACK SIDE. REMAINDER OF CURRENT HIGHLIGHTS WILL
REMAIN IN EFFECT...ALTHOUGH MOST WILL LIKELY COME DOWN AS
SCHEDULED BASED ON CURRENT SPEED OF THE SYSTEM.
&&
.AVIATION /FOR 12Z TAF ISSUANCE/...
EXPECT WIDESPREAD MVFR CONDITIONS ACROSS WESTERN COLORADO THROUGH
19Z THIS AFTERNOON WITH PERIODS OF IFR CIGS AND VSBYS IN SNOW
SHOWERS. MOUNTAINS AND HIGH PASSES WILL BE OBSCD. SLOW
CLEARING WILL OCCUR FROM WEST TO EAST TODAY AS THE STORM
RESPONSIBLE FOR THE SNOW MOVES OUT OF THE REGION...WITH VFR
CONDITIONS RETURNING BY MID EVENING.
&&
.PREV DISCUSSION /ISSUED 410 AM MST SUN JAN 22 2012/...
SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
COLD FRONT WAS WORKING THROUGH THE SOUTHERN ZONES THIS MORNING AS
THE UPPER TROUGH WAS SHIFTING EAST OF THE FORECAST AREA. Q
CONVERGENT FILED WILL BE EAST OF THE DIVIDE BY SUNRISE SIGNALING AN
END TO DYNAMICAL SUPPORT...BUT MOIST COLD ADVECTION IN NW OROGRAPHIC
FLOW WILL CONTINUE TO PRODUCE SNOWFALL THIS MORNING IN THE COLORADO
MOUNTAINS AND HIGH VALLEYS. THE LATEST HRRR AND RUC MODELS ARE
EMPHASIZING MORNING SNOW OVER THE CENTRAL COLORADO MTNS ESPECIALLY
THE NW SAN JUANS. HEAVY WET SNOW FELL SATURDAY INTO THE EVENING BUT
QUICKLY DROPPING MOUNTAIN TEMPERATURES ARE PRODUCING HIGHER RATIO
FLUFFY SNOW THIS MORNING FOR RIGHT-SIDE-UP SNOW CONDITIONS. THE
VALLEYS HAVE STAYED SURPRISINGLY MILD AND ONLY FLIRTING WITH
FREEZING LIMITING SNOW ACCUMULATIONS IN THE CENTRAL AND SOUTHERN
VALLEYS.
SUN COMES OUT THIS AFTERNOON FOR MOST LOCATIONS AS NW GRADIENT
WINDS RELAX SOMEWHAT. LIGHT SHOWERS EXPECTED TO CONTINUE THIS
AFTERNOON IN THE EASTERN PORTION OF THE FORECAST AREA. LOW LEVEL
MOISTURE NEVER FULLY ERODES UNDER WEAK RIDGING TONIGHT INTO
MONDAY. THE NEXT SPLITTING STORM COMES ONSHORE ON MONDAY WITH THE
BRUNT OF DYNAMICS DIGGING THROUGH SOUTHERN AZ MONDAY NIGHT.
SNOWFALL WILL INCREASE OVER NORTH FACING SLOPES...BUT ACCUMULATIONS
ARE EXPECTED TO BE LIGHT.
LONG TERM /TUESDAY THROUGH SUNDAY/...
SPLITTING TROUGH HEADED ACROSS THE GREAT BASIN WILL BE SENDING
ENERGY NORTH AND SOUTH OF THE FORECAST AREA AS WE START OFF THIS
PERIOD. BEST MOISTURE AND FORCING APPEARS TO BE OVER THE SAN JUANS
WITH THIS STORM...BUT AMOUNTS LOOKING MORE AND MORE MEAGER WITH
EACH RUN. SHOULD SEE A FEW INCHES OF NEW SNOW...BUT MAY NOT EVEN
REACH ADVISORY CRITERIA. WILL JUST MAINTAIN THE HIGH CHANCE TO LOW
LIKELY POPS WE CURRENTLY HAVE RUNNING. THIS SYSTEM EXITS TUESDAY
NIGHT...WITH FLAT DIRTY RIDGE LEFT IN ITS WAKE. THE FLAT RIDGING
WILL KEEP THE MAJORITY OF THE FORECAST AREA DRY...WITH THE EXCEPTION
BEING THE NORTHERN MOUNTAINS WHERE OCCASIONAL WEAK WAVES PASS...
SQUEEZING OUT A FEW SNOW SHOWERS. NO SIGNIFICANT ACCUMULATIONS
EXPECTED THROUGH THURSDAY ACROSS OUR FORECAST AREA. THAT LOOKS TO
CHANGE BY FRIDAY AS BOTH THE ECMWF AND GFS ADVERTISING ANOTHER
STRONG PACIFIC SYSTEM TO SLIDE SOUTHEAST ACROSS THE GREAT BASIN AND
INTO WESTERN COLORADO AS HEIGHTS RISE ALONG THE WEST COAST. THIS
COULD BRING ANOTHER ROUND OF MORE SIGNIFICANT PRECIP...FAVORING THE
NORTHERN AND CENTRAL MOUNTAINS. FOR NOW...WILL JUST RAMP UP POPS
SLIGHTLY. TEMPS REMAIN SEASONAL THROUGH THIS PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL NOON MST TODAY FOR ZONES 002>005-
008>010-012-013.
WINTER WEATHER ADVISORY UNTIL 9 AM MST THIS MORNING FOR ZONE 014.
WINTER STORM WARNING UNTIL 9 AM MST THIS MORNING FOR ZONES 018-
019.
UT...NONE.
&&
$$
UPDATE.......JDC
SHORT TERM...JOE
LONG TERM....JDC
AVIATION.....TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
410 AM MST SUN JAN 22 2012
.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
COLD FRONT WAS WORKING THROUGH THE SOUTHERN ZONES THIS MORNING AS
THE UPPER TROUGH WAS SHIFTING EAST OF THE FORECAST AREA. Q
CONVERGENT FILED WILL BE EAST OF THE DIVIDE BY SUNRISE SIGNALING AN
END TO DYNAMICAL SUPPORT...BUT MOIST COLD ADVECTION IN NW OROGRAPHIC
FLOW WILL CONTINUE TO PRODUCE SNOWFALL THIS MORNING IN THE COLORADO
MOUNTAINS AND HIGH VALLEYS. THE LATEST HRRR AND RUC MODELS ARE
EMPHASIZING MORNING SNOW OVER THE CENTRAL COLORADO MTNS ESPECIALLY
THE NW SAN JUANS. HEAVY WET SNOW FELL SATURDAY INTO THE EVENING BUT
QUICKLY DROPPING MOUNTAIN TEMPERATURES ARE PRODUCING HIGHER RATIO
FLUFFY SNOW THIS MORNING FOR RIGHT-SIDE-UP SNOW CONDITIONS. THE
VALLEYS HAVE STAYED SURPRISINGLY MILD AND ONLY FLIRTING WITH
FREEZING LIMITING SNOW ACCUMULATIONS IN THE CENTRAL AND SOUTHERN
VALLEYS.
SUN COMES OUT THIS AFTERNOON FOR MOST LOCATIONS AS NW GRADIENT
WINDS RELAX SOMEWHAT. LIGHT SHOWERS EXPECTED TO CONTINUE THIS
AFTERNOON IN THE EASTERN PORTION OF THE FORECAST AREA. LOW LEVEL
MOISTURE NEVER FULLY ERODES UNDER WEAK RIDGING TONIGHT INTO
MONDAY. THE NEXT SPLITTING STORM COMES ONSHORE ON MONDAY WITH THE
BRUNT OF DYNAMICS DIGGING THROUGH SOUTHERN AZ MONDAY NIGHT.
SNOWFALL WILL INCREASE OVER NORTH FACING SLOPES...BUT ACCUMULATIONS
ARE EXPECTED TO BE LIGHT.
.LONG TERM /TUESDAY THROUGH SUNDAY/...
SPLITTING TROUGH HEADED ACROSS THE GREAT BASIN WILL BE SENDING
ENERGY NORTH AND SOUTH OF THE FORECAST AREA AS WE START OFF THIS
PERIOD. BEST MOISTURE AND FORCING APPEARS TO BE OVER THE SAN JUANS
WITH THIS STORM...BUT AMOUNTS LOOKING MORE AND MORE MEAGER WITH
EACH RUN. SHOULD SEE A FEW INCHES OF NEW SNOW...BUT MAY NOT EVEN
REACH ADVISORY CRITERIA. WILL JUST MAINTAIN THE HIGH CHANCE TO LOW
LIKELY POPS WE CURRENTLY HAVE RUNNING. THIS SYSTEM EXITS TUESDAY
NIGHT...WITH FLAT DIRTY RIDGE LEFT IN ITS WAKE. THE FLAT RIDGING
WILL KEEP THE MAJORITY OF THE FORECAST AREA DRY...WITH THE EXCEPTION
BEING THE NORTHERN MOUNTAINS WHERE OCCASIONAL WEAK WAVES PASS...
SQUEEZING OUT A FEW SNOW SHOWERS. NO SIGNIFICANT ACCUMULATIONS
EXPECTED THROUGH THURSDAY ACROSS OUR FORECAST AREA. THAT LOOKS TO
CHANGE BY FRIDAY AS BOTH THE ECMWF AND GFS ADVERTISING ANOTHER
STRONG PACIFIC SYSTEM TO SLIDE SOUTHEAST ACROSS THE GREAT BASIN AND
INTO WESTERN COLORADO AS HEIGHTS RISE ALONG THE WEST COAST. THIS
COULD BRING ANOTHER ROUND OF MORE SIGNIFICANT PRECIP...FAVORING THE
NORTHERN AND CENTRAL MOUNTAINS. FOR NOW...WILL JUST RAMP UP POPS
SLIGHTLY. TEMPS REMAIN SEASONAL THROUGH THIS PERIOD.
&&
.AVIATION /FOR 12Z TAF ISSUANCE/...
EXPECT WIDESPREAD MVFR CONDITIONS ACROSS WESTERN COLORADO THROUGH
19Z THIS AFTERNOON WITH PERIODS OF IFR CIGS AND VSBYS IN SNOW
SHOWERS. MOUNTAINS AND HIGH PASSES WILL BE OBSCD. SLOW
CLEARING WILL OCCUR FROM WEST TO EAST TODAY AS THE STORM
RESPONSIBLE FOR THE SNOW MOVES OUT OF THE REGION...WITH VFR
CONDITIONS RETURNING BY MID EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL NOON MST TODAY FOR ZONES
002>005-008>010-012-013.
WINTER WEATHER ADVISORY UNTIL 9 AM MST THIS MORNING FOR
ZONE 014.
WINTER STORM WARNING UNTIL 9 AM MST THIS MORNING FOR
ZONES 018-019.
WINTER WEATHER ADVISORY UNTIL 6 AM MST EARLY THIS MORNING FOR
ZONES 020>023.
UT...NONE.
&&
$$
SHORT TERM...JOE
LONG TERM....JDC
AVIATION.....TGJT
AREA FORECAST DISCUSSION...CORRECTED
NWS GRAND JUNCTION CO
407 AM MST SUN JAN 22 2012
.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
COLD FRONT WAS WORKING THROUGH THE SOUTHERN ZONES THIS MORNING AS
THE UPPER TROUGH WAS SHIFTING EAST OF THE FORECAST AREA. Q
CONVERGENT FILED WILL BE EAST OF THE DIVIDE BY SUNRISE SIGNALING AN
END TO DYNAMICAL SUPPORT...BUT MOIST COLD ADVECTION IN NW OROGRAPHIC
FLOW WILL CONTINUE TO PRODUCE SNOWFALL THIS MORNING IN THE COLORADO
MOUNTAINS AND HIGH VALLEYS. THE LATEST HRRR AND RUC MODELS ARE
EMPHASIZING MORNING SNOW OVER THE CENTRAL COLORADO MTNS ESPECIALLY
THE NW SAN JUANS. HEAVY WET SNOW FELL SATURDAY INTO THE EVENING BUT
QUICKLY DROPPING MOUNTAIN TEMPERATURES ARE PRODUCING HIGHER RATIO
FLUFFY SNOW THIS MORNING FOR RIGHT-SIDE-UP SNOW CONDITIONS. THE
VALLEYS HAVE STAYED SURPRISINGLY MILD AND ONLY FLIRTING WITH
FREEZING LIMITING SNOW ACCUMULATIONS IN THE CENTRAL AND SOUTHERN
VALLEYS.
SUN COMES OUT THIS AFTERNOON FOR MOST LOCATIONS AS NW GRADIENT
WINDS RELAX SOMEWHAT. LIGHT SHOWERS EXPECTED TO CONTINUE THIS
AFTERNOON IN THE EASTERN PORTION OF THE FORECAST AREA. LOW LEVEL
MOISTURE NEVER FULLY ERODES UNDER WEAK RIDGING TONIGHT INTO
MONDAY. THE NEXT SPLITTING STORM COMES ONSHORE ON MONDAY WITH THE
BRUNT OF DYNAMICS DIGGING THROUGH SOUTHERN AZ MONDAY NIGHT.
SNOWFALL WILL INCREASE OVER NORTH FACING SLOPES...BUT ACCUMULATIONS
ARE EXPECTED TO BE LIGHT.
.LONG TERM /TUESDAY THROUGH SUNDAY/...
SPLITTING TROUGH HEADED ACROSS THE GREAT BASIN WILL BE SENDING
ENERGY NORTH AND SOUTH OF THE FORECAST AREA AS WE START OFF THIS
PERIOD. BEST MOISTURE AND FORCING APPEARS TO BE OVER THE SAN JUANS
WITH THIS STORM...BUT AMOUNTS LOOKING MORE AND MORE MEAGER WITH
EACH RUN. SHOULD SEE A FEW INCHES OF NEW SNOW...BUT MAY NOT EVEN
REACH ADVISORY CRITERIA. WILL JUST MAINTAIN THE HIGH CHANCE TO LOW
LIKELY POPS WE CURRENTLY HAVE RUNNING. THIS SYSTEM EXITS TUESDAY
NIGHT...WITH FLAT DIRTY RIDGE LEFT IN ITS WAKE. THE FLAT RIDGING
WILL KEEP THE MAJORITY OF THE FORECAST AREA DRY...WITH THE EXCEPTION
BEING THE NORTHERN MOUNTAINS WHERE OCCASIONAL WEAK WAVES PASS...
SQUEEZING OUT A FEW SNOW SHOWERS. NO SIGNIFICANT ACCUMULATIONS
EXPECTED THROUGH THURSDAY ACROSS OUR FORECAST AREA. THAT LOOKS TO
CHANGE BY FRIDAY AS BOTH THE ECMWF AND GFS ADVERTISING ANOTHER
STRONG PACIFIC SYSTEM TO SLIDE SOUTHEAST ACROSS THE GREAT BASIN AND
INTO WESTERN COLORADO AS HEIGHTS RISE ALONG THE WEST COAST. THIS
COULD BRING ANOTHER ROUND OF MORE SIGNIFICANT PRECIP...FAVORING THE
NORTHERN AND CENTRAL MOUNTAINS. FOR NOW...WILL JUST RAMP UP POPS
SLIGHTLY. TEMPS REMAIN SEASONAL THROUGH THIS PERIOD.
&&
.AVIATION /FOR 12Z TAF ISSUANCE/...
EXPECT WIDESPREAD MVFR CONDITIONS ACROSS WESTERN COLORADO THROUGH
19Z THIS AFTERNOON WITH PERIODS OF IFR CIGS AND VSBYS IN SNOW
SHOWERS. MOUNTAINS AND HIGH PASSES WILL BE OBSCD. SLOW
CLEARING WILL OCCUR FROM WEST TO EAST TODAY AS THE STORM
RESPONSIBLE FOR THE SNOW MOVES OUT OF THE REGION...WITH VFR
CONDITIONS RETURNING BY MID EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL NOON MST TODAY FOR ZONES
002>005-008>010-012-013.
WINTER WEATHER ADVISORY UNTIL 9 AM MST THIS MORNING FOR
ZONE 014.
WINTER STORM WARNING UNTIL 9 AM MST THIS MORNING FOR
ZONES 018-019.
WINTER WEATHER ADVISORY UNTIL 6 AM MST EARLY THIS MORNING FOR
ZONES 020>023.
UT...NONE.
&&
$$
SHORT TERM...JOE
LONG TERM....JDC
AVIATION.....TGJT
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
940 AM EST Sun Jan 22 2012
.UPDATE (Rest of today through tonight)...
14Z water vapor and H4 RUC analysis shows an amplifying upper level
pattern across the CONUS. Main feature of note is a sharp and
energetic upper trough ejecting eastward from the inter-mountain
west across the central/southern Plains. This energy is forecast to
result in a potentially significant severe weather outbreak across
portions of the southern/central MS valley later today and this
evening. As a result of the significant height falls spreading
across the central portion of the country, we have seen downstream
ridging amplify over the SE Conus during the past 12-18 hours. The
influence of this strengthening ridge can clearly be seen in the 12Z
KTLH sounding profile, which shows a well defined subsidence
inversion above 700mb. Below this level the column is nearly
saturated. This setup of dry descending air overtop a moist boundary
layer is classic for fog formation. In addition, the high dewpoint
air moving northward over the relatively cooler shelf waters gave an
additional boost to the overall coverage of fog. Just now starting
to see visibility observations begin to improve, and this trend will
continue as diurnal mixing strengthens into the midday.
Closer to the surface, analysis indicates a fairly well-defined warm
frontal feature extending west to east in the proximity of the I-10
corridor. Low level upglide along the 295-305K surface over this
boundary is proving to be enough forcing to result in a scattering
of shallow showers across the Big Bend and Panhandle zones this
morning. Have update the PoPs for these southern zones the next few
hours to account for guidance/radar trends.
Heading into the afternoon, upper ridge axis will rapidly push east
of the region as a lead southern stream impulse ejects along the
northern Gulf Coast. Surface warm front will begin a slow retreat
northward as well reaching a position closer to KDHN and KABY by
early evening. As the front move north, so will the best associated
upglide. For this reason expect to see most of the shower activity
over our FL zones move north into AL/GA. Over these AL/GA zones
later today, the low level upglide will be aided by overspread large
scale ascent ahead of the approaching shortwave. With this in mind
have bumped up PoPs to around 40% this afternoon/early evening, and
added a chance of thunder. This scenario is consistent with
solutions from most of the hi-res CAM guidance.
Tonight,
Lead southern stream shortwave will pass our longitude during the
evening hours as the more impressive upper trough pivots across the
MS/TN valleys. Surface cold front will slowly be approaching from
the west, reaching western AL toward sunrise Monday. Momentum ahead
of this front will continue the warm frontal retreat well to our
north during the night. Continued the chance for showers/isolated
storms north of the FL border for a period this evening, however as
the surface front exits, and the upper trough passes by, should see
most activity/convection come to an end for a large portion of the
overnight. Have updated PoP/Wx/QPF grids to account for this
generally drier forecast after 03-05Z. Pre-frontal convection
associated with the cold front may begin to effect our far western
zones late tonight, however guidance consensus now shows that the
majority of this activity will remain just to our west until very
late tonight, and more likely the daylight hours of Monday. As of
now, the slight risk area for severe storms remains just to the NW
of our zones, however wind fields will be strengthening, allowing
the possibility for a stronger thunderstorm in the vicinity of
Coffee/Geneva/Walton counties late tonight.
&&
.MARINE...
A warm front north of the waters will retreat northward overnight.
A cold front will approach from the west later tonight into Monday,
but is expected to wash out before crossing the area. Without a
frontal passage, onshore flow will continue through the middle of
the week. Winds and seas will stay below headline criteria at least
through Wednesday. Winds and seas are expected to elevate late in
the week as a strong cold front approaches and passes through the
marine area. Areas of dense fog will be a concern the next few days
especially over the nearshore waters.
&&
.AVIATION (THROUGH 12Z MONDAY)...
The VIS/CIG restrictions will gradually improving to MVFR.
Conditions do not favor ceilings rising to VFR today...except
potentially late around KTLH and KECP. Scattered showers and
isolated thunderstorms will be possible as well today. Best chances
will be around KTLH and KECP this morning, and then shifting
northward into AL/GA this afternoon/evening. A better chance for TS
will come late tonight into Monday morning at KDHN. Otherwise, IFR
conditions are forecast to re-develop during the overnight hours.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 78 54 76 56 73 / 30 10 20 20 30
Panama City 74 60 73 60 70 / 30 20 30 20 30
Dothan 78 61 74 56 68 / 40 40 40 30 40
Albany 74 57 72 57 68 / 40 50 30 30 40
Valdosta 78 56 76 55 74 / 30 40 20 10 20
Cross City 79 52 76 54 74 / 10 10 10 10 20
Apalachicola 71 59 71 59 69 / 20 10 20 20 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...Dense Fog Advisory until 10 AM EST /9 AM CST/ Monday for
Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal
Franklin-Coastal Gulf-Coastal Jefferson-Coastal
Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland
Dixie-Inland Franklin-Inland Gulf-Inland Jefferson-Inland
Taylor-Inland Wakulla-Inland Walton-Jackson-Lafayette-
Leon-Liberty-Madison-South Walton-Washington.
GM...Dense Fog Advisory until 1 PM EST Monday for Apalachee Bay-
Coastal waters From Ochlockonee River to Apalachicola FL
out to 20 NM-Coastal waters from Suwannee River to Keaton
Beach FL out 20 NM-Coastal waters from Apalachicola to
Destin FL out 20 NM-Waters from Suwannee River to
Apalachicola FL from 20 to 60 NM.
&&
$$
MROCZKA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
812 AM MST SUN JAN 22 2012
.UPDATE...
803 AM MST SUN JAN 22 2012
UPDATED GRIDS AND ZONES TO ADJUST PRECIPITATION TYPES. FORECAST
SOUNDINGS FOR THE FA INDICATE ALL RAIN FOR MOST OF THE MORNING AND
THEN A POSSIBLE MIX WITH SNOW AROUND NOON. SINCE THIS IS A FAST
MOVING SYSTEM EXITING THE FA BY EARLY AFTERNOON DO NOT EXPECT ANY
ACCUMULATION OTHER THAN SOME MINOR LOCALIZED AMOUNTS IN EXTREME
SOUTHWEST NEBRASKA ZONES. OTHERWISE NO OTHER CHANGES TO THE
CURRENT FORECAST.
FS
&&
.DISCUSSION...
339 AM MST SUN JAN 22 2012
MAIN FORECAST PROBLEM WILL BE TODAY. SATELLITE CONTINUING TO SHOW A
PROGRESSIVE AND ACTIVE WAVE TRAIN FROM THE PACIFIC INTO THE WESTERN
ATLANTIC. VERY STRONG SHORTWAVE APPROACHING FROM THE WEST THIS
MORNING WILL CAUSE A RATHER ACTIVE WEATHER DAY ACROSS THE REGION.
NEXT SYSTEM TO AFFECT THE AREA IS APPROACHING THE WEST COAST.
AT JET LEVEL THE NAM AND ECWMF WERE HANDLING THE STRONG SOUTHERN JET
APPROACHING OUR AREA AT THIS TIME. THIS WAS ESPECIALLY TRUE WITH
THE SEGMENT OVER THE OCEAN. AT MID LEVELS THE MODELS WERE HAVING A
LITTLE TROUBLE WITH THE INCOMING SYSTEM. THIS SYSTEM IS VERY STRONG
NOW AND IS LOOKING LIKE IT IS STILL STRENGTHENING. IMPRESSIVE AND
WIDESPREAD HEIGHT FALLS OF A LEAST 100 METERS TO ALMOST 200 METER
IN THE 700 TO 500 MB LAYER. THE NAM...CANADIAN AND ECMWF WERE DOING
THE BEST WITH THE SYSTEM AND WERE THE DEEPEST/SLOWEST.
TODAY/TONIGHT...00Z MODEL DATA CAME IN AND WAS STRONGER...SLOWER...
AND COLDER WITH INCOMING SYSTEM. PV ANALYSIS SHOWS THE 1.5 VALUE
DOWN AS LOW AS NEAR 500 MB. SIGNIFICANT SUBSIDENCE IS OCCURRING ON
THE BACKSIDE OF THE SYSTEM. LIGHTNING ALSO HAS OCCURRED WITH THE
SYSTEM. NO MATTER WHICH MODEL ONE CHOOSES...THEY ALL PRODUCE HIGH
WIND WARNING CRITERIA WINDS ACROSS THE ENTIRE AREA WITH THE GFS THE
STRONGEST. THE WESTERN PORTION OF THE AREA WILL HAVE THE HIGH
SPEEDS AND GUSTS DUE TO VERY HIGH LAPSE RATES...STRONGEST DOWNWARD
MOTION...AND HIGHEST THREE HOUR PRESSURE RISES. ALREADY HAVE ISSUED
AN UPDATE TO HAVE A HIGH WIND WARNING FOR THE ENTIRE AREA FROM 13Z
TO 01Z. COMPARISONS BETWEEN DIFFERENT STORMS IS NEVER PERFECT.
HOWEVER...THIS SETUP IS SIMILAR TO HIGH WIND EVENT THAT AREA
EXPERIENCED ON DECEMBER 31.
WHAT MAKES THIS SITUATION EVEN MORE INTERESTING IS THE PRECIPITATION
FORECAST. WIDESPREAD LIGHT PRECIPITATION LOOKS LIKE IT WILL OCCUR
OVER THE ENTIRE AREA. MODELS ARE NOW COLDER AND SHOWING SNOW WILL
BE POSSIBLE...ESPECIALLY ALONG AND NORTH OF THE INTERSTATE. THIS
WILL CREATE BLOWING SNOW PROBLEMS. CHOSE TO HANDLE THIS SITUATION
WITH ENHANCED WARNING FOR THE SNOW IN THE NPW. DAY SHIFT WILL NEED
TO TAKE A CLOSE LOOK AT THIS. WILL WATCH THE TEMPERATURES FOR AS
LONG AS POSSIBLE TONIGHT AND MAKE FINAL ADJUSTMENTS ON THE MAXES...
WHICH LOOK TO BE EARLY IN THE DAY. LATEST CANADIAN AND ESPECIALLY
THE HRRR CAPTURING REALITY WELL AND ADJUSTED ACCORDINGLY. THIS ALSO
MAY CAUSE ADJUSTMENTS TO THE PRECIPITATION PHASE. LATEST OBSERVATIONS
AND MODEL DATA SUPPORT THE WEATHER AND POP FORECAST PUT IN BY THE
EVENING SHIFT. NEWER DATA DOES SUPPORT A LITTLE MORE QPF THAN EARLIER
WAS THINKING. SO DID RAISE QPF AND SNOW AMOUNTS A LITTLE.
NEXT QUESTION IS WHAT TO DO WITH THE FIRE WEATHER WATCH. NEWER MODEL
GUIDANCE DOES NOT DROP DEWPOINTS AS MUCH AS BEFORE. PLUS
TEMPERATURES LOOK TO NOT BE AS WARM DUE TO THE SLOWER PROGRESSION
OF THE SYSTEM. ALSO EXPECT SOME LIGHT PRECIPITATION TO HAVE OCCURRED
AS WELL. AT PRESENT...THERE ONLY APPEARS TO BE AN EXTREMELY SMALL
WINDOW WHERE FIRE WEATHER CONCERNS CAN BE MET. ALSO BY THE
TIME THE DEWPOINTS COME DOWN...TEMPERATURES HAVE ALSO COOLED FROM
EARLY DAY MAXES. SO WILL CANCEL THE FIRE WEATHER WATCH.
WINDS LOOK TO DECOUPLE RATHER QUICKLY AND WILL HAVE LOW DEWPOINTS.
LOWERED MINS A LITTLE BUT STILL MAY NEED TO BE LOWERED.
MONDAY/MONDAY NIGHT...LIGHTER WINDS AND A DECENT AMOUNT OF SUN
BEHIND EXITING SYSTEM AND SURFACE RIDGE. THINKING IS THAT THERE WILL
BE MORE COLD AIR WITH THIS SYSTEM THAN CURRENTLY ADVERTISED PLUS
MAY BE SOME MINOR SNOW COVER ON THE GROUND. MODEL GUIDANCE NOT TOO
DIFFERENT BUT TRENDED TOWARD THE COOLER GUIDANCE. CLOUD COVER STARTS
INCREASING DURING THE NIGHT IN ADVANCE OF OUR NEXT SYSTEM.
TUESDAY/TUESDAY NIGHT...STRONG NORTH TO SOUTH JET EXISTS BEHIND
INCOMING SYSTEM. MAIN UPPER SYSTEM IS NOW FURTHER SOUTH THAN
YESTERDAY WITH MODELS IN GENERAL AGREEMENT ON ITS LOCATION OVER NEW
MEXICO. HOWEVER...THE CANADIAN IS FURTHER SOUTH THAN THAT WITH THE
SREF IN BETWEEN THE CANADIAN AND THE REMAINING GUIDANCE. MORE OPEN
BUT STILL MODERATE TO STRONG NORTHERN PORTION OF THIS SYSTEM MOVES
ACROSS AREA WITH SMALL SCALE 700 MB CIRCULATIONS IN FAVORABLE
LOCATIONS. MODELS BRING A GREAT DEAL OF MID LEVEL MOISTURE OVER THE
AREA DURING THE DAY WITH THE LOWER LEVELS BEING SLOWER TO MOISTEN
UP. HOWEVER...MODELS ARE SHOWING RATHER STRONG MESOSCALE AND
SYNOPTIC SCALE FORCING WITH FAVORABLE THETA-E LAPSE RATES IN PLACE.
MOST MODEL OUTPUT SHOWING VERY LIGHT QPF AND CONSIDERING ALL
PARAMETERS THAT MAKES SENSE. THINKING THE LIKELIHOOD OF MEASURABLE
IS LOW BUT THE PROBABILITY OF SOMETHING FALLING FROM THE SKY IS
RATHER HIGH. SO INSERTED SPRINKLES AND FLURRIES INTO THE FORECAST
FOR THE ENTIRE DAY AND INTO EARLY IN THE EVENING. DAY SHIFT WILL
HAVE TO TAKE ANOTHER CLOSE LOOK AT THIS DAY. CONSIDERING THE
THICKENING CLOUD COVER...UNFAVORABLE WIND DIRECTION...AND SOME COLD
AIR ADVECTION...TEMPERATURES SHOULD NOT DO MUCH THROUGH THE DAY.
THE NAM WAS MUCH COLDER THAN THE REST BUT AM NOT READY TO GO THERE
YET. DID LOWER MAXES SOME TO START TRENDING IN THAT DIRECTION.
BULLER
WEDNESDAY THROUGH SATURDAY...SHORTWAVE RIDGE EXPECTED TO BUILD OVER
CWA AS TROUGH SHIFT EAST. RESULT WILL BE DRY CONDITIONS AND WARMING
TREND THROUGH THURSDAY. ABOVE NORMAL TEMPS EXPECTED BOTH WED AND
THU...WITH MID/UPPER 50S ON THURSDAY. SHORTWAVE TROUGH PUSHES ACROSS
NORTHERN PLAINS FRI/SAT WITH ASSOCIATED COLD FRONT PUSHING SOUTH
OVER CWA. SIGNIFICANT DIFFERENCES IN DETERMINISTIC GUIDANCE ON
TIMING OF THESE FEATURES...WITH ECMWF CURRENTLY FASTER AND WETTER.
CONSIDERING POSITION OF SHORTWAVE AND LITTLE IN THE WAY OF ENSEMBLE
SUPPORT FOR ECMWF SOLUTION...IVE KEPT FORECAST DRY. I ALSO KEPT
TEMPS CLOSER TO CLIMATE NORMALS SHOWING A TEMPERED COOING TREND
FRI/SAT RATHER THAN THE COLDER ECMWF SOLUTION. IN ANY
CASE...CONFIDENCE BELOW NORMAL FOR DAYS 6/7.
DR
THANKS TO ALL THAT COLLABORATED.
&&
.AVIATION...
410 AM MST SUN JAN 22 2012
FOR THE 12Z TAFS...CONDITIONS ARE EXPECTED TO DETERIORATE AFTER 15Z
AS STRONG STORM SYSTEM MOVES INTO THE PLAINS FROM THE WEST. STRONG
WINDS AND LIGHT SNOW WILL OVERSPREAD BOTH TERMINALS FROM THE WEST TO
THE EAST DURING THE MORNING HOURS. MVFR CONDITIONS WILL BE
ASSOCIATED WITH LIGHT SNOW AND BLOWING SNOW AFTER 16Z AT KGLD AND
17Z AT KMCK. WHILE POSSIBLE...CONFIDENCE WAS TOO LOW TO INCLUDE IFR
CIGS IN TAFS THIS CYCLE WITH THESE CONDITIONS NOT EXPECTED TO
PREVAIL. BY 00Z BOTH TERMINALS SHOULD SEE CIGS AND VIS QUICKLY RISE
TO VFR AND CONTINUE THROUGH THE REST OF THE PERIOD. NORTHWEST WINDS
OF 30-40KTS WITH HIGHER GUSTS WILL BE COMMON DURING THE DAY. AT KGLD
GUSTS AROUND 55KTS OR HIGHER ARE EXPECTED BETWEEN 16Z-21Z...WITH
GUSTS UP TO 50KTS OVER KMCK 18Z-00Z.
DR
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
KSZ001>004-013>016-027>029-041-042.
NE...HIGH WIND WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
NEZ079>081.
CO...HIGH WIND WARNING UNTIL 6 PM MST THIS EVENING FOR COZ090>092.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
709 AM CST SUN JAN 22 2012
.UPDATE...
LIGHT PRECIPITATION BEGINNING TO SPREAD INTO NORTHWEST KANSAS
BASED ON MOSAIC RADAR. BASED ON THE RUC THE HIGHER RETURNS
APPEARS TO BE ASSOCIATED WITH AN AREA OF 850-700MB FRONTOGENESIS
UNDER THE 500MB DEFORMATION ZONE. THIS BAND OF FRONTOGENESIS IS
CURRENTLY FORECAST TO MOVE TO NEAR SYRACUSE AND SCOTT CITY BY 15Z
AND THEN CROSS THE REMAINDER OF SOUTHWEST KANSAS BETWEEN 15Z AND
21Z. HAVE THEREFORE ADJUSTED TIMING OF INCREASING CLOUDS AND
DEVELOPING PRECIPITATION. LEFT EXIT REGION OF A 250 JET CONTINUES
TO HIGHLIGHT NORTH CENTRAL KANSAS AS AN AREA OF BETTER LIFT
BETWEEN 18Z AND 21Z SO WILL ALSO INCREASE PRECIPITATION CHANCES IN
THIS REGION LATER THIS AFTERNOON. -RB
&&
.PREV DISCUSSION... /ISSUED 512 AM CST SUN JAN 22 2012/
AVIATION...
FOR THE 12Z TAF ISSUANCE...
NAM12 AND RUC40 WERE IN DECENT AGREEMENT WITH COLD FRONTAL
PASSAGE EARLY THIS MORNING. AS OF 9Z THESE MODELS WERE NOT DOING
THAT BAD WITH THE FRONTS POSITION ACROSS NORTHWEST KANSAS. AS A
RESULT WILL FOLLOW THE TIMING OF THESE MODELS, AS WELL AS
INCREASING WINDS THAT WILL FOLLOW THE FRONTAL PASSAGE. BASED ON
BOUNDARY LAYER, 0-0.5KM MEAN WINDS, AND 850MB WINDS DEVELOPING BY
18Z WILL TREND TOWARDS THE STRONGER MAV GUIDANCE ON WIND SPEEDS.
THESE STRONG WINDS WILL BEGIN TO SUBSIDE AFTER 23Z.
IN ADDITION TO THESE STRONG WINDS MOISTURE ACCOMPANYING A 850-700
BAROCLINIC ZONE WILL SPREAD SOUTHEAST ACROSS WESTERN KANSAS
BETWEEN 15Z AND 21Z. IMPROVING FRONTOGENESIS WILL OCCUR IN THIS
AREA WHICH WILL BE LOCATED AHEAD OF A 500MB UPPER LEVEL TROUGH.
THIS WILL BE ENOUGH FOR A PERIOD OF LOWER VFR CIGS LATE THIS
MORNING/EARLY THIS AFTERNOON. A FEW SPRINKLES/LIGHT RAIN SHOWERS
ALSO CAN NOT BE RULED OUT BUT AT THIS TIME WIDESPREAD
PRECIPITATION IS NOT ANTICIPATED. WILL THEREFORE KEEP VICINITY
WORDING FOR THE POSSIBILITY OF LIGHT PRECIPITATION LATER TODAY AS
THE 850-700MB BAROCLINIC ZONE CROSSES THE AREA.-RB
PREV DISCUSSION... /ISSUED 242 AM CST SUN JAN 22 2012/
DISCUSSION...
SHORT TERM /TODAY THROUGH MONDAY NIGHT/
THE REGIONAL AND SYNOPTIC SCALE FEATURES THIS MORNING INCLUDE A
RAPIDLY ADVANCING UPPER LEVEL TROUGH/PV ANOMALY FROM THE WESTERN
STATES THROUGH THE CENTRAL ROCKIES THIS MORNING. MEANWHILE, STEADY
SURFACE PRESSURE FALLS HAVE BECOME NEARLY NEUTRAL ON MSAS ACROSS THE
HIGH PLAINS FROM WYOMING THROUGH WESTERN KANSAS. SOUTHERLY, BETTER
THAN EXPECTED MIXED SURFACE WINDS ACROSS THE FAR WESTERN COUNTIES
HAVE HELPED MAINTAIN MILD TEMPERATURES OVERNIGHT IN THE LOW 50S AND
UPPER 40S. AS THE UPPER TROUGH APPROACHES, INCREASING PERIODICITY OF
MID LEVEL CLOUD BANDS ARE BEGINNING TO DEVELOP WHICH ARE BEING
OBSERVED IN THE REGIONAL 11-3.9 MICRON AND INFRARED SATELLITE
IMAGERY.
THE CURRENT MODELS RUNS HAVE COME TOGETHER WITH MUCH STRONGER 2
METER WIND SPEEDS THAN A FEW RUNS AGO, AND ALL OF THE MODELS SEEM TO
BE INCREASING MAGNITUDE WITH TIME. THERE IS NOT A SIGNIFICANTLY
DEEP UNSTABLE LAYER, BUT THE NAM DOES INDICATE VERY IMPRESSIVE LOW
LEVEL 0-1 KM LAPSE RATES LATE THIS MORNING AND THIS AFTERNOON NEAR
10 DEG C/KM IN AN ENVIRONMENT WITH 40 KNOT SUSTAINED WINDS JUST
OFF THE SURFACE. EVEN THE 40KM GFS IS INDICATING 25 TO 30 KNOT 2
METER WINDS TODAY. GFS MOS IS PRODUCING SUSTAINED WIND SPEEDS
ACROSS THE WESTERN COUNTIES AROUND 40+ KNOTS SUSTAINED LATE
MORNING AND EARLY AFTERNOON. AS A RESULT, WE HAVE INCREASED
CONFIDENCE IN HOISTING A HIGH WIND WARNING FOR ALL AREAS ALONG
WEST OF GENERALLY THE HIGHWAY 283 CORRIDOR. A RAPIDLY COOLING
BOUNDARY LAYER SHOULD BRING THE WIND SPEEDS DOWNS IN THE MID TO
LATE AFTERNOON, BUT CONDITIONS MAY REMAIN BREEZY THROUGH THE LATE
AFTERNOON AND EVEN THE EARLY EVENING IN THE EASTERN COUNTIES. A
DECENT LAYER OF 800-700 MB MOISTURE TRANSPORT DOES SHOW UP IN
MODEL FIELDS BEHIND THIS BOUNDARY AND MODEL SOUNDINGS SHOW AN
IMPRESSIVE SATURATED LAYER BEHIND THE PV ANOMALY IN THE COLD POOL
OF AIR. THERMAL FIELDS INDICATE SOME DENDRITIC PRODUCTION IS
POSSIBLE AND EVEN LIKELY, BUT LOW LEVEL TEMPERATURES MAY NOT
SUPPORT THAT AND RAIN SHOWERS ARE PROBABLY THE MORE LIKELY
PRECIPITATION TYPE WITH THIS WAVE.
POPS AND WINDS WILL DIMINISH RAPIDLY IN THE EVENING. THE EXTENT TO
HOW COLD IT GETS OVERNIGHT WILL DEPEND ON THE MAGNITUDE OF COLD
ADVECTION, BUT THE COLDER MOS SEEMS THE BEST CHOICE TONIGHT.
TEMPERATURES ARE NOT EXPECTED TO REBOUND SIGNIFICANTLY IN MONDAY
OTHER THAN USUAL DIURNAL HEATING AS WEAK SOUTHERLY RETURN FLOW OF
COLD ANTICYLONE AIR REMAINS. ANOTHER RELATIVELY COOL NIGHT WITH GOOD
RADIATIONAL COOLING IN THE LOW 20S IS ANTICIPATED MONDAY
NIGHT.
LONG TERM...
BY TUESDAY NIGHT OUR NEXT PACIFIC UPPER LEVEL STORM SYSTEM WILL BE
DIGGING INTO SOUTHEAST NEW MEXICO. THIS UPPER LEVEL TROUGH WAS ALSO
STARTING TO BECOME CUT OFF FROM THE MEAN FLOW AS WELL. THE NEW 00Z
MODELS NOT DIFFERING MUCH FROM THE PREVIOUS MODEL RUNS IN THIS UPPER
LOW DEVELOPING NEAR THE MEXICO/SOUTHWEST TEXAS BORDER BY EARLY
WEDNESDAY AND THEN SLOWLY DRIFTING EAST THROUGH LATE WEEK. AHEAD OF
THIS SYSTEM ABUNDANT MID TO UPPER LEVEL MOISTURE IS ANTICIPATED TO
SPREAD INTO WESTERN KANSAS. GIVEN THE MOISTURE EXPECTED AND
DIFLUENT FLOW DEVELOPING WITH THE 500MB DEFORMATION ZONE WILL
INCREASE CLOUD COVER AND AS A RESULT OF THIS LOWER TEMPERATURES
TUESDAY AFTERNOON.
ON TUESDAY NIGHT THE 500MB DEFORMATION ZONE WILL MOVE
SOUTH/SOUTHEAST OF THE AREA. BEHIND THIS DEFORMATION ZONE
ANTICYCLONIC FLOW DEVELOPS ACROSS WESTERN KANSAS WITH LIMITED
MOISTURE PRESENT. GIVEN THE CLEARING SKIES AND 900-850MB TEMPERATURE
TRENDS THE PREVIOUS TEMPERATURE FORECAST STILL LOOKS ON TRACK WITH
WARMER TEMPERATURES RETURNING TO WESTERN KANSAS. THIS WARMUP HOWEVER
WILL BE SHORT LIVED AS ANOTHER COLD FRONT IS FORECAST TO BEGIN TO
DROP SOUTH ACROSS THE NORTHERN PLAINS LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 20 50 23 / 40 0 0 0
GCK 45 18 49 22 / 30 0 0 0
EHA 50 19 50 25 / 20 0 0 0
LBL 50 18 50 23 / 20 0 0 0
HYS 45 18 49 20 / 40 0 0 0
P28 50 22 53 26 / 30 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 10 AM CST /9 AM MST/ THIS MORNING TO 5 PM
CST /4 PM MST/ THIS AFTERNOON FOR KSZ030-043>045-061>064-074>078-
084>088.
WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR KSZ031-046-065-066-079>081-089-090.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
548 AM CST SUN JAN 22 2012
.AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
STRONG MOISTURE ADVECTION HAS RESULTED IN WIDESPREAD IFR CIGS
EARLY THIS MORNING OVER EASTERN KS. AT KCNU THEY SHOULD GRADUALLY
LIFT TO MVFR BY LATE MORNING. THINKING IFR CIGS WILL FLIRT WITH
KICT-KSLN-KHUT THROUGH LATE MORNING...BUT BRUNT OF THESE CIGS
SHOULD REMAIN EAST OF I-135 CORRIDOR. STRONG SOUTHWESTERLY LOW-
LEVEL JET OF 45-55 KTS IS AFFECTING THE AREA THIS MORNING...BUT
LLWS IS MARGINAL AT ALL TAF SITES DUE TO STRONG GROUND-LEVEL
WINDS. OTHERWISE...A STRONG COLD FRONT WILL BLAST SOUTHEAST ACROSS
THE AREA THIS AFTERNOON/EVENING. STRONG NORTHWEST WINDS ARE
ANTICIPATED BEHIND THE FRONT...ALONG WITH WIDESPREAD MVFR TO LOW
VFR CIGS AND SCATTERED RAIN SHOWERS. CIGS/SHOWERS SHOULD EXIT TO
THE EAST BY MID TO LATE EVENING...WITH WINDS SLACKENING SOME.
KLEINSASSER
&&
.PREV DISCUSSION... /ISSUED 314 AM CST SUN JAN 22 2012/
DISCUSSION...
TODAY-TONIGHT:
INITIAL ISSUE IS EVOLUTION OF LOW CLOUDS...WITH RUC STRUGGLING TO
STAY IN THE BALLPARK AND OTHERS EVEN WORSE. GIVEN TRENDS...SHOULD
SEE SLOW IMPROVEMENT THROUGHOUT THE MORNING ON WESTERN EDGE...BUT
SOUTHEAST KS WILL BE VERY SLOW TO CLEAR. SOME PATCHY DRIZZLE IS
POSSIBLE IN SOUTHEAST KS...FORTUNATELY TEMPERATURES WILL BE ABOVE
FREEZING. ALL MODELS SHOW SIGNIFICANT DRY SLOT WORKING ACROSS
SOUTHERN SECTIONS DURING THE AFTERNOON AHEAD OF COLD AIR
ADVECTION. MEANWHILE SURFACE PRESSURE GRADIENT AND LAPSE RATES
SHOULD SPREAD LOW END WIND ADVISORY CRITERIA OVER THE AREA WEST OF
A SLN-HARPER LINE FOR A FEW HOURS THIS AFTERNOON. WITH ARRIVAL OF
850MB MOISTURE...SHOULD SEE SPRINKLES/LIGHT RAIN DEVELOP THIS
AFTERNOON IN CENTRAL KS...AND SPREAD INTO THE FLINT HILLS FOR A
FEW HOURS THIS EVENING. LOOKS LIKE TEMPERATURES WILL BE WARM
ENOUGH THIS AFTERNOON/EVENING FOR PRECIPITATION TO REMAIN LIQUID.
DOWNGLIDE SHOULD QUICKLY SHUT DOWN PRECIPITATION IN THE EVENING.
WINDS WILL LIKELY REMAIN BRISK FOR MUCH OF THE NIGHT. A TOUGH CALL
ON LOWS GIVEN THE OPPOSITE IMPACTS OF WINDS AND COLD AIR ADVECTION.
MON-MON NIGHT:
RELATIVELY QUIET WEATHER ANTICIPATED WITH TEMPERATURES STILL
REMAINING AT OR ABOVE NORMAL.
TUE-TUE NIGHT:
PLAN TO STAY THE COURSE ON PRECIPITATION THIS PERIOD. MODELS
STILL STRUGGLING TO CONVERGE AS TO HOW FAR NORTH LOW LEVEL
MOISTURE WILL GO. HOWEVER BOTH GFS/ECMWF HAVE BEEN CONSISTENT THAT
EXTENSIVE HIGH CLOUDS WILL COVER THE AREA DURING THE DAY ON TUE.
USUALLY AM NOT AS CONFIDENT IN HIGH LEVEL MOISTURE MODEL
FORECASTS BEYOND DAYS 1-2...BUT THIS SEEMS REASONABLE GIVEN THE
DIFFLUENT UPPER FLOW NE OF UPPER LOW. GIVEN THE COOL START...LIGHT
SOUTHEAST WINDS AND EXTENSIVE CLOUDS...TEMPERATURES SHOULD STRUGGLE.
WED-SUN:
00 UTC RUN OF THE ECMWF HAS BROKE CONTINUITY...WITH NEW RUN
RESEMBLING THE 20/12 UTC RUN. THIS IS A FASTER/DEEPER SOLN. GFS
MEANWHILE HAS BEEN STRUGGLING AS WELL...ALTHOUGH FORECAST AREA
REMAINS IN BETWEEN THE US-CANADIAN BORDER SURFACE LOW AND
INCONSISTENT WEAK UPPER LOW IN THE SOUTHERN PLAINS. NET RESULT AT
LEAST FOR NOW IS DRY AND ABOVE NORMAL TEMPERATURES. OTHERWISE WILL
NEED TO WAIT FOR MORE CONSISTENCY BEFORE MAKING ANY SUBSTANTIAL
CHANGES. -HOWERTON
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
STRATUS CLOUDS HAVE ARRIVED AHEAD OF SCHEDULE MAINLY EAST OF THE
KANSAS TURNPIKE LATE THIS EVENING. AREAS MOST LIKELY TO BE IMPACTED
BY MVFR CIGS THROUGH THE MORNING HOURS ON SUNDAY WILL BE KICT AND
KCNU. IFR/LIFR WILL BE POSSIBLE THROUGH THE EARLY MORNING HOURS AT
KCNU WITH AREAS OF DRIZZLE WITHIN AN AREA OF LOW LEVEL
WAA/MOISTURE ADVECTION. INCREASING LARGE-SCALE FORCING FOR
SUBSIDENCE AND LOW LEVEL DRY AIR WILL SWEEP ACROSS THE AREA IN THE
WAKE OF A PRE-FRONTAL TROUGH DURING THE EARLY AFTERNOON HOURS WITH
A RETURN TO VFR ACROSS THE AREA. IN ADDITION...STRONG
WEST/NORTHWEST WINDS AROUND 25-35 KNOTS WILL BE POSSIBLE ACROSS
PORTIONS OF CENTRAL AND SOUTH CENTRAL KANSAS THROUGH THE AFTERNOON
HOURS.
MWM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 48 25 51 27 / 20 10 0 0
HUTCHINSON 46 26 49 27 / 30 10 0 0
NEWTON 48 27 48 27 / 30 10 0 0
ELDORADO 53 27 50 27 / 10 10 0 0
WINFIELD-KWLD 57 27 56 29 / 10 10 0 0
RUSSELL 45 22 50 22 / 30 10 0 0
GREAT BEND 43 22 50 22 / 30 10 0 0
SALINA 46 26 51 23 / 30 10 0 0
MCPHERSON 46 26 50 25 / 30 10 0 0
COFFEYVILLE 59 31 53 29 / 10 10 0 0
CHANUTE 53 29 50 26 / 10 10 0 0
IOLA 50 30 49 27 / 10 10 0 0
PARSONS-KPPF 56 27 52 26 / 10 10 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM CST THIS EVENING
FOR KSZ032-033-047>051-067-082-091.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
339 AM MST SUN JAN 22 2012
.DISCUSSION...
339 AM MST SUN JAN 22 2012
MAIN FORECAST PROBLEM WILL BE TODAY. SATELLITE CONTINUING TO SHOW A
PROGRESSIVE AND ACTIVE WAVE TRAIN FROM THE PACIFIC INTO THE WESTERN
ATLANTIC. VERY STRONG SHORTWAVE APPROACHING FROM THE WEST THIS
MORNING WILL CAUSE A RATHER ACTIVE WEATHER DAY ACROSS THE REGION.
NEXT SYSTEM TO AFFECT THE AREA IS APPROACHING THE WEST COAST.
AT JET LEVEL THE NAM AND ECWMF WERE HANDLING THE STRONG SOUTHERN JET
APPROACHING OUR AREA AT THIS TIME. THIS WAS ESPECIALLY TRUE WITH
THE SEGMENT OVER THE OCEAN. AT MID LEVELS THE MODELS WERE HAVING A
LITTLE TROUBLE WITH THE INCOMING SYSTEM. THIS SYSTEM IS VERY STRONG
NOW AND IS LOOKING LIKE IT IS STILL STRENGTHENING. IMPRESSIVE AND
WIDESPREAD HEIGHT FALLS OF A LEAST 100 METERS TO ALMOST 200 METER
IN THE 700 TO 500 MB LAYER. THE NAM...CANADIAN AND ECMWF WERE DOING
THE BEST WITH THE SYSTEM AND WERE THE DEEPEST/SLOWEST.
TODAY/TONIGHT...00Z MODEL DATA CAME IN AND WAS STRONGER...SLOWER...
AND COLDER WITH INCOMING SYSTEM. PV ANALYSIS SHOWS THE 1.5 VALUE
DOWN AS LOW AS NEAR 500 MB. SIGNIFICANT SUBSIDENCE IS OCCURRING ON
THE BACKSIDE OF THE SYSTEM. LIGHTNING ALSO HAS OCCURRED WITH THE
SYSTEM. NO MATTER WHICH MODEL ONE CHOOSES...THEY ALL PRODUCE HIGH
WIND WARNING CRITERIA WINDS ACROSS THE ENTIRE AREA WITH THE GFS THE
STRONGEST. THE WESTERN PORTION OF THE AREA WILL HAVE THE HIGH
SPEEDS AND GUSTS DUE TO VERY HIGH LAPSE RATES...STRONGEST DOWNWARD
MOTION...AND HIGHEST THREE HOUR PRESSURE RISES. ALREADY HAVE ISSUED
AN UPDATE TO HAVE A HIGH WIND WARNING FOR THE ENTIRE AREA FROM 13Z
TO 01Z. COMPARISONS BETWEEN DIFFERENT STORMS IS NEVER PERFECT.
HOWEVER...THIS SETUP IS SIMILAR TO HIGH WIND EVENT THAT AREA
EXPERIENCED ON DECEMBER 31.
WHAT MAKES THIS SITUATION EVEN MORE INTERESTING IS THE PRECIPITATION
FORECAST. WIDESPREAD LIGHT PRECIPITATION LOOKS LIKE IT WILL OCCUR
OVER THE ENTIRE AREA. MODELS ARE NOW COLDER AND SHOWING SNOW WILL
BE POSSIBLE...ESPECIALLY ALONG AND NORTH OF THE INTERSTATE. THIS
WILL CREATE BLOWING SNOW PROBLEMS. CHOSE TO HANDLE THIS SITUATION
WITH ENHANCED WARNING FOR THE SNOW IN THE NPW. DAY SHIFT WILL NEED
TO TAKE A CLOSE LOOK AT THIS. WILL WATCH THE TEMPERATURES FOR AS
LONG AS POSSIBLE TONIGHT AND MAKE FINAL ADJUSTMENTS ON THE MAXES...
WHICH LOOK TO BE EARLY IN THE DAY. LATEST CANADIAN AND ESPECIALLY
THE HRRR CAPTURING REALITY WELL AND ADJUSTED ACCORDINGLY. THIS ALSO
MAY CAUSE ADJUSTMENTS TO THE PRECIPITATION PHASE. LATEST OBSERVATIONS
AND MODEL DATA SUPPORT THE WEATHER AND POP FORECAST PUT IN BY THE
EVENING SHIFT. NEWER DATA DOES SUPPORT A LITTLE MORE QPF THAN EARLIER
WAS THINKING. SO DID RAISE QPF AND SNOW AMOUNTS A LITTLE.
NEXT QUESTION IS WHAT TO DO WITH THE FIRE WEATHER WATCH. NEWER MODEL
GUIDANCE DOES NOT DROP DEWPOINTS AS MUCH AS BEFORE. PLUS
TEMPERATURES LOOK TO NOT BE AS WARM DUE TO THE SLOWER PROGRESSION
OF THE SYSTEM. ALSO EXPECT SOME LIGHT PRECIPITATION TO HAVE OCCURRED
AS WELL. AT PRESENT...THERE ONLY APPEARS TO BE AN EXTREMELY SMALL
WINDOW WHERE FIRE WEATHER CONCERNS CAN BE MET. ALSO BY THE
TIME THE DEWPOINTS COME DOWN...TEMPERATURES HAVE ALSO COOLED FROM
EARLY DAY MAXES. SO WILL CANCEL THE FIRE WEATHER WATCH.
WINDS LOOK TO DECOUPLE RATHER QUICKLY AND WILL HAVE LOW DEWPOINTS.
LOWERED MINS A LITTLE BUT STILL MAY NEED TO BE LOWERED.
MONDAY/MONDAY NIGHT...LIGHTER WINDS AND A DECENT AMOUNT OF SUN
BEHIND EXITING SYSTEM AND SURFACE RIDGE. THINKING IS THAT THERE WILL
BE MORE COLD AIR WITH THIS SYSTEM THAN CURRENTLY ADVERTISED PLUS
MAY BE SOME MINOR SNOW COVER ON THE GROUND. MODEL GUIDANCE NOT TOO
DIFFERENT BUT TRENDED TOWARD THE COOLER GUIDANCE. CLOUD COVER STARTS
INCREASING DURING THE NIGHT IN ADVANCE OF OUR NEXT SYSTEM.
TUESDAY/TUESDAY NIGHT...STRONG NORTH TO SOUTH JET EXISTS BEHIND
INCOMING SYSTEM. MAIN UPPER SYSTEM IS NOW FURTHER SOUTH THAN
YESTERDAY WITH MODELS IN GENERAL AGREEMENT ON ITS LOCATION OVER NEW
MEXICO. HOWEVER...THE CANADIAN IS FURTHER SOUTH THAN THAT WITH THE
SREF IN BETWEEN THE CANADIAN AND THE REMAINING GUIDANCE. MORE OPEN
BUT STILL MODERATE TO STRONG NORTHERN PORTION OF THIS SYSTEM MOVES
ACROSS AREA WITH SMALL SCALE 700 MB CIRCULATIONS IN FAVORABLE
LOCATIONS. MODELS BRING A GREAT DEAL OF MID LEVEL MOISTURE OVER THE
AREA DURING THE DAY WITH THE LOWER LEVELS BEING SLOWER TO MOISTEN
UP. HOWEVER...MODELS ARE SHOWING RATHER STRONG MESOSCALE AND
SYNOPTIC SCALE FORCING WITH FAVORABLE THETA-E LAPSE RATES IN PLACE.
MOST MODEL OUTPUT SHOWING VERY LIGHT QPF AND CONSIDERING ALL
PARAMETERS THAT MAKES SENSE. THINKING THE LIKELIHOOD OF MEASURABLE
IS LOW BUT THE PROBABILITY OF SOMETHING FALLING FROM THE SKY IS
RATHER HIGH. SO INSERTED SPRINKLES AND FLURRIES INTO THE FORECAST
FOR THE ENTIRE DAY AND INTO EARLY IN THE EVENING. DAY SHIFT WILL
HAVE TO TAKE ANOTHER CLOSE LOOK AT THIS DAY. CONSIDERING THE
THICKENING CLOUD COVER...UNFAVORABLE WIND DIRECTION...AND SOME COLD
AIR ADVECTION...TEMPERATURES SHOULD NOT DO MUCH THROUGH THE DAY.
THE NAM WAS MUCH COLDER THAN THE REST BUT AM NOT READY TO GO THERE
YET. DID LOWER MAXES SOME TO START TRENDING IN THAT DIRECTION.
BULLER
WEDNESDAY THROUGH SATURDAY...SHORTWAVE RIDGE EXPECTED TO BUILD OVER
CWA AS TROUGH SHIFT EAST. RESULT WILL BE DRY CONDITIONS AND WARMING
TREND THROUGH THURSDAY. ABOVE NORMAL TEMPS EXPECTED BOTH WED AND
THU...WITH MID/UPPER 50S ON THURSDAY. SHORTWAVE TROUGH PUSHES ACROSS
NORTHERN PLAINS FRI/SAT WITH ASSOCIATED COLD FRONT PUSHING SOUTH
OVER CWA. SIGNIFICANT DIFFERENCES IN DETERMINISTIC GUIDANCE ON
TIMING OF THESE FEATURES...WITH ECMWF CURRENTLY FASTER AND WETTER.
CONSIDERING POSITION OF SHORTWAVE AND LITTLE IN THE WAY OF ENSEMBLE
SUPPORT FOR ECMWF SOLUTION...IVE KEPT FORECAST DRY. I ALSO KEPT
TEMPS CLOSER TO CLIMATE NORMALS SHOWING A TEMPERED COOING TREND
FRI/SAT RATHER THAN THE COLDER ECMWF SOLUTION. IN ANY
CASE...CONFIDENCE BELOW NORMAL FOR DAYS 6/7.
DR
THANKS TO ALL THAT COLLABORATED.
&&
.AVIATION...
1020 PM MST SAT JAN 21 2012
FOR THE 06Z TAFS AT KGLD AND KMCK...VFR EXPECTED THROUGH 15Z BEFORE
LOWERING TO IFR FROM 16Z-22Z (BOTH CIGS AND VIS) AS A POTENT BUT
QUICK MOVING UPPER LEVEL TROUGH AND COLD FRONT MOVE THROUGH. BY 00Z
AT BOTH TERMINALS SHOULD SEE CIGS AND VIS QUICKLY RISE TO VFR AND
CONTINUE THROUGH THE REST OF THE PERIOD. NORTHWEST WINDS OF 30-40KTS
WITH HIGHER GUSTS WILL BE COMMON. AT KGLD GUSTS OVER 50KTS EXPECTED
BETWEEN 16Z-21Z IN BOTH PRECIPITATION AND SUBSIDENCE BEHIND
DEPARTING WAVE. DURING THE TIME OF EXPECTED PRECIP SHOULD SEE
SHARPLY LOWER VISIBILITIES IN SNOW AND BLOWING SNOW.
007
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WARNING FROM 6 AM MST /7 AM CST/ TO 6 PM MST /7 PM
CST/ SUNDAY FOR KSZ001>004-013>016-027>029-041-042.
NE...HIGH WIND WARNING FROM 6 AM MST /7 AM CST/ TO 6 PM MST /7 PM
CST/ SUNDAY FOR NEZ079>081.
CO...HIGH WIND WARNING FROM 6 AM TO 6 PM MST SUNDAY FOR COZ090>092.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
951 AM EST SUN JAN 22 2012
.SYNOPSIS...
COOL AND MOIST CONDITIONS WILL PREVAIL TODAY AS HIGH PRESSURE
WEDGES IN FROM THE NORTH. A WARM FRONT WILL LIFT NORTH ACROSS THE
REGION MONDAY. A COLD FRONT IS EXPECTED TO CROSS THE AREA MONDAY
NIGHT INTO TUESDAY. HIGH PRESSURE WILL FOLLOW LATE TUESDAY THROUGH
MID WEEK. ANOTHER FRONT WILL APPROACH FROM THE NORTH LATE THURSDAY
WHILE A MORE POTENT LOW PRESSURE SYSTEM MOVES IN FROM THE GULF COAST
FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SUNDAY...COLD FRONT HAS PUSHED AS FAR SOUTH AS THE
GA/FL STATE LINE...AND HIGH PRESSURE CONTINUES TO WEDGE DOWN THROUGH
THE MID ATLANTIC AND INTO THE CAROLINAS. WIDESPREAD OVERCAST LOW
CLOUDINESS AND DRIZZLE ONGOING ACROSS MUCH OF THE AREA WILL
CONTINUE...AND POSSIBLY EXPAND IN COVERAGE THIS AFTERNOON. TIME
HEIGHTS AND FORECAST SOUNDINGS DEPICT FULL SATURATION BENEATH THE
FRONTAL INVERSION...WHICH IS BEING WRUNG OUT BY ANY WEAK IMPULSES
THAT PUSH THROUGH IN THE MID LEVELS. ADDITIONALLY...ISENTROPIC
ANALYSIS REVEALS ONLY WEAK LIFT ON THE 290K SURFACE...BUT IN A FULLY
SATURATED ENVIRONMENT THIS IS ENOUGH TO PRODUCE DRIZZLE. HAVE KEPT
POP SILENT SINCE IT IS DOUBTFUL ANY PLACES WILL MEASURE MORE THAN A
TRACE...BUT A FEW SPOTS MAY MEASURE 0.01 INCHES.
LATEST MSAS ANALYSIS HAS THE WEDGE STRENGTHENING...AND HRRR 3-HR
PRESSURE TENDENCIES CONTINUE TO RISE. THIS INCREASING
PRESSURE...STRENGTHENING WEDGE...WILL KEEP THE AREA LOCKED IN WITH
LOW CLOUDS AND DRIZZLE THROUGH TONIGHT. BECAUSE OF THIS...DIURNAL
TEMPERATURE SWINGS WILL BE QUITE MINIMAL...AND HAVE BUMPED MAX TEMPS
DOWN A BIT BASED OFF CURRENT OBS. EXPECT HIGHS ONLY INTO THE LOWER
40S WELL NW...TO THE UPPER 40S MOST OF THE AREA. A FEW 50 DEGREE
READINGS MAY BE REACHED ALONG THE SOUTH COAST.
WEDGE BEGINS TO BREAK DOWN TONIGHT AS WINDS BECOME MORE
EASTERLY...AND WAA ALOFT BEGINS. CONTINUED ATYPICAL DIURNAL CURVE
TONIGHT...WITH MINS LIKELY BE REACHED BEFORE MIDNIGHT...AND THEN
RISING TOWARDS DAYBREAK MONDAY. AGAIN...VERY LITTLE SWING IN TEMPS
WITH LOWS IN THE LOW/MID 40S BY MIDNIGHT...RISING TO THE MID/UPPER
40S BY 7AM MONDAY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...WITH PROGRESSIVE NATURE TO THE FLOW...THE
SHALLOW COLD WEDGE SHOULD BREAK MONDAY MORNING AS LOW PRESSURE
SYSTEM PUSHES EAST ACROSS THE UPPER MID WEST DRAGGING A COLD FRONT
TOWARD THE AREA. WINDS WILL COME AROUND TO THE SOUTHEAST AND THEN
SOUTH THROUGH MON IN A DEEPER RETURN FLOW. THIS WILL DRIVE TEMPS
BACK UP INTO THE 60S CLOSE TO 70 MON AFTN. SOME UNCERTAINTY EXISTS
AS TO HOW MUCH IN THE WAY OF CLOUDS AND PCP WILL EXIST THROUGH
MONDAY INTO TUESDAY. SHOULD BE SOME LIFT EARLIER ON MONDAY AS WARM
FRONT LIFTS NORTH AND THEN AGAIN AHEAD AND ALONG COLD FRONT AS IT
MOVES INTO AREA. LATEST MODEL RUNS SHOW FRONT LACKING MOISTURE AS IT
MOVES INTO AREA LATE MONDAY BUT IT MAY LINGER ACROSS OR JUST SOUTH
OF AREA AS MID TO UPPER RIDGE BUILDS UP FROM THE GULF INTO MID
WEEK. THEREFORE MAY BE CLOUDS AND SLIM CHC OF PCP LINGERING INTO
TUES AND MID TO HIGH CLOUDS WILL STREAM INTO AREA IN WESTERLY FLOW
ALOFT AS ANOTHER SYSTEM DEVELOPS ALONG WESTERN GULF COAST. AFTER
WAA ON MONDAY...850 TEMPS LEVEL OFF THROUGH THE REMAINDER OF THE
PERIOD. MAY SEE A SHALLOW COOL POOL OF AIR MOVE IN FINALLY LATE
TUES INTO EARLY WED BUT OVERALL EXPECT TEMPS TO MAKE IT INTO THE
60S ON TUES AGAIN.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...MID TO UPPER RIDGE WILL SLIP OFF THE COAST
WITH A DEEP SW FLOW SETTING UP WED THROUGH FRI AS LOW PRESSURE
SYSTEM MOVES EAST THROUGH THE GULF COAST STATES INTO THE
SOUTHEAST. LIGHT NORTHERLY SFC WINDS BEHIND COLD FRONT EARLY WED WILL
SHIFT AROUND ONCE AGAIN AS RETURN FLOW SETS UP LATE WED. THIS WILL
PROVIDE DEEPER LAYER MOISTURE WITH PCP WATER VALUES REMAINING
ABOVE AN INCH THROUGH MUCH OF THE PERIOD. MOST OF THIS MOISTURE
WILL BE IN THE WAY OF MID TO UPPER LEVEL CLOUDS STREAMING INTO THE
AREA UNTIL THURS NIGHT WHEN ANOTHER COLD FRONT MAKES IT WAY DOWN
FROM THE NORTH. THIS FRONT WILL MOVE SOUTH BUT WILL NOT MAKE IT
MUCH FARTHER THAN LOCAL AREA BEFORE STORM SYSTEM MOVES EAST FROM
THE GULF PUSHING THIS BOUNDARY BACK NORTH. THE BEST CHC OF PCP
WILL COME FRI INTO SAT AS SHORTWAVE DRIVES THIS SYSTEM INTO AND
THROUGH THE CAROLINAS FROM THE WEST SOUTHWEST. COLD AND DRY HIGH
PRESSURE WILL MOVE IN BEHIND COLD FRONT LATE SAT INTO SUN. TEMPS
WILL REMAIN ABOVE 60 FOR HIGHS UNTIL FRONT MOVES THROUGH ON SAT
ALLOWING COLDER AIR TO MAKE ITS WAY IN FOR LATE SAT INTO SUNDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...WIDESPREAD LOW CEILINGS ARE OCCURRING THIS MORNING.
LOWEST CEILINGS OF 300-600 FEET ARE OCCURRING AT THE COASTAL
TERMINALS...WITH CEILINGS 600-900 FEET AT THE INLAND TERMINALS.
PATCHY DRIZZLE AND FOG ARE RESULTING IN MVFR VISIBILITIES.
EXPECT THE SURFACE HIGH TO FURTHER BUILD INTO THE TERMINALS EARLY
TODAY. CONFIDENCE IS HIGH THAT CEILINGS WILL LIFT TO MVFR LEVELS
LATE MORNING/EARLY AFTERNOON...BUT CONFIDENCE IN EXACT TIMING IS
LOW. NORTH TO NORTHEAST WINDS AROUND 10 KNOTS ARE EXPECTED THROUGH
THE DAY.
AS THE SURFACE HIGH RETREATS BACK TO THE NORTH LATER TODAY THE
FRONTAL INVERSION WILL LOWER. WITH COPIOUS MOISTURE TRAPPED AT THE
INVERSION LEVEL CONFIDENCE IS MODERATE TO HIGH THAT CEILINGS WILL
DROP BACK TO IFR LEVELS THIS EVENING...WITH LIFR CEILINGS/MVFR
VISIBILITIES DEVELOPING AROUND MIDNIGHT. CONFIDENCE IS LOW...BUT
IN THE PRE-DAWN HOURS CEILINGS AND VISIBILITIES COULD APPROACH
TERMINAL MINIMUMS.
EXTENDED OUTLOOK...VFR TO DEVELOP MONDAY LATE WITH A SLIGHT CHANCE
OF SHOWERS AS A WARM FRONT WORKS NORTH. LOW CONFIDENCE FOR MORNING
FOG WEDNESDAY AND THURSDAY MORNINGS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SUNDAY...SCEC CONTINUES FOR AMZ250 AND AMZ252 WITH THE
BUOYS REPORTING WINDS STILL GUSTING TO 25 KTS ON NE SURGE. SEAS ARE
MOSTLY 3-4 FT...BUT WITH FRYING PAN REPORTING 6 FT...EXPECT WAVE
HEIGHTS NEAR THE 20 NM BOUNDARY ARE CRESTING AT 5 FT IF NOT SLIGHTLY
HIGHER...WITH A SHORT PERIOD NE WIND WAVE CONTROLLING THE SPECTRUM.
STILL EXPECT TO DROP THE SCEC AROUND NOON...BUT IF WEDGE CONTINUES
TO STRENGTHEN THIS COULD KEEP WINDS AND SEAS ELEVATED..AND PROMPT AN
EXTENSION. ATTM EXPECT WINDS TO EASE TO 10-15 KTS THIS AFTN AND
TONIGHT...PRODUCING NE WIND WAVES OF 3-4 FT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...WINDS WILL SHIFT AROUND TO THE SOUTHEAST AND
THEN SOUTH IN AN INCREASING RETURN FLOW ONCE AGAIN MON. WIND WILL
REACH 15 TO 20 KTS LATE MON. THIS WILL PUSH SEAS UP AGAIN INTO THE 3
TO 5 FT RANGE BUT LATEST WNA RUNS KEEP SEAS BELOW SCA THRESHOLDS
FOR MON NIGHT AS COLD FRONT APPROACHES AND MOVES THROUGH. COLD
FRONT MAY BE SLOWER TO MOVE THROUGH WITH LONGER PERIOD OF SW TO W
WINDS BEFORE FINALLY VEERING AROUND LATE TUES. SEAS WILL DECREASE BY
LATE TUES INTO TUES NIGHT AS FRONT MOVES SOUTH WITH DIMINISHING
NORTHERLY FLOW.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...WINDS WILL VEER AROUND FROM THE NORTHEAST TO
EAST AND EVENTUALLY SOUTH WEDNESDAY INTO THURSDAY AS FRONT PUSHES
BACK NORTH AND STORM SYSTEM APPROACHES FROM THE GULF COAST. SEAS
DOWN TO LESS THAN 3 FT WEDNESDAY WILL INCREASE AGAIN AS SOUTHERLY
RETURN FLOW INCREASES UP TO 15 TO 20 KTS ONCE AGAIN LATE THURS. THIS
WILL DRIVE SEAS BACK UP TO 3 TO 5 FT THURSDAY INTO FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WEISS
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS NORMAN OK
536 AM CST SUN JAN 22 2012
.AVIATION...MOIST RETURN FLOW FOR A FEW HOURS THIS MORNING WILL
YIELD LIGHT FOG AND IFR STRATUS AT CENTRAL OKLAHOMA SITES. WINDS
BEGIN THE PERIOD ABOVE 12 KT AT MOST LOCATIONS. LIGHT AND BACKED
SURFACE WINDS AT KLAW WILL CONTINUE TO PROMOTE LLWS UNTIL DEEPER
MIXING BEGINS AROUND 22/15Z. WINDS SET TO VEER TO WESTERLY AND
INCREASE MARKEDLY BEHIND A PACIFIC COLD FRONT...WITH GUSTS ABOVE
30 KT BY 22/18Z. A STRONGER WIND SHIFT WILL FOLLOW IN THE
AFTERNOON HOURS...RESULTING IN A BRIEF PERIOD OF INTENSE WIND...
ESPECIALLY WESTERN OKLAHOMA SITES...WHERE GUSTS MAY EXCEED 45 KT.
SPEEDS WILL DIMINISH RATHER QUICKLY LATE IN THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 405 AM CST SUN JAN 22 2012/
DISCUSSION...ACTIVE WEATHER TODAY WITH HIGH WINDS AND EXTREME FIRE
WEATHER CONDITIONS.
LOW PRESSURE APPROACHING 995 MB WILL TRACK EASTWARD NEAR THE
KANSAS BORDER DURING THE DAYLIGHT HOURS...WHILE A COMPACT MID
LEVEL JET MAX EJECTS SOUTH OF THE SURFACE LOW ACROSS OKLAHOMA AND
NORTH TEXAS. THIS SCENARIO OFTEN LEADS TO SEVERE WIND GUSTS EVEN
IN MID WINTER.
THERE ARE TWO NOTEWORTHY SURFACE BOUNDARIES. A PACIFIC FRONT WILL
REACH INTERSTATE 35 BY NOON TO 1 PM AND CONTINUE EASTWARD.
ALTHOUGH THE LOW LEVEL JET WILL MAKE FOR A BREEZY MORNING...THE
WIND WILL INCREASE MARKEDLY BEHIND THE PACIFIC FRONT...WHERE DEEP
MIXING WILL OCCUR. WE EXPANDED THE WIND ADVISORY TO ACCOUNT FOR
THIS. MEANWHILE...A SECOND COLD FRONT EMANATING FROM THE
ROCKIES/HIGH PLAINS WILL DIVE INTO WESTERN OK AND WESTERN NORTH TX
THIS AFTERNOON. TRENDS IN THE NAM AND RUC SUGGEST GUSTS ABOVE 50
OR 60 MPH WILL OCCUR WITH THIS FRONT...AND WE HAVE ISSUED A HIGH
WIND WARNING FOR PORTIONS OF WESTERN OKLAHOMA.
THE RUC ALSO SUGGESTS HIGH WIND CRITERIA COULD BE MET OVER FAR
WESTERN NORTH TEXAS BENEATH THE MID LEVEL JET...AND EVEN PRIOR TO
THE ARRIVAL OF THE SECOND...STRONGER FRONT. WE WERE NOT QUITE
CONVINCED BECAUSE MOST OF THE COLD ADVECTION BEHIND THE PACIFIC
FRONT OCCURS PRIOR TO DEEP MIXING IN THAT AREA...AND THE TIGHTER
GRADIENTS ASSOCIATED WITH THE SECOND FRONT WILL PASS NORTH THROUGH
OKLAHOMA. THE DAY SHIFT MAY NEED TO EXPAND THE HIGH WIND WARNING
INTO TEXAS IF THE OBSERVATIONS SUGGEST IT IS NEEDED. WE ADJUSTED
THE RED FLAG WARNING BASED ON THE HUMIDITY FORECAST...ADDING ONLY
CLAY COUNTY.
THE WIND WILL QUIET DOWN BY MONDAY MORNING...AND WE GO BACK TO OUR
ACTIVE WESTERLY JET ALOFT WITH SEASONABLE OR RELATIVELY MILD
TEMPERATURES FOR THE WEEK AHEAD. THE JET WILL BUCKLE ENOUGH FOR A
CLOSED LOW TO PRODUCE RAIN OVER TEXAS AND OKLAHOMA MID
WEEK...BEFORE IT IS RE-ABSORBED IN THE FLOW. IT HAS BEEN DIFFICULT
THIS WINTER TO PREDICT EXACTLY WHERE THE LOW WILL CLOSE OFF...AND
HOW QUICKLY IT WILL BE RE-ABSORBED. IT DOES LOOK...THOUGH...AS IF
THERE IS A FAIRLY GOOD CHANCE OF SOME RAIN ACCUMULATION TUESDAY
NIGHT AND EARLY WEDNESDAY FROM NORTH TEXAS INTO SOUTHERN OKLAHOMA.
THE OPERATIONAL MODEL SOLUTIONS WOULD BRING GREATER RAIN COVERAGE
AND AMOUNTS FARTHER NORTHWARD INTO OKLAHOMA...BUT WE DID NOT
COMMIT IN THAT DIRECTION...AS THE OPERATIONAL RUNS ARE QUITE A BIT
FARTHER NORTH THEN THE VAST MAJORITY OF THE GFS ENSEMBLE MEMBERS.
THE NEXT SHOT OF COLDER WEATHER IS EXPECTED EARLY NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 30 57 35 / 10 0 0 0
HOBART OK 64 31 58 34 / 0 0 0 0
WICHITA FALLS TX 69 34 62 39 / 0 0 0 0
GAGE OK 59 23 54 25 / 20 0 0 0
PONCA CITY OK 62 29 55 31 / 10 10 0 0
DURANT OK 70 39 61 40 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR OKZ007-008-012-013-018>020-023>030-036>038-044.
HIGH WIND WARNING FROM 11 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR OKZ004>006-009>011-014>017-021-022-033>035.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
OKZ031-032-039>042-045-046-050.
TX...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR TXZ083>089.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
TXZ090.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
26/22/22
BURKE
AREA FORECAST DISCUSSION
NWS NORMAN OK
405 AM CST SUN JAN 22 2012
.DISCUSSION...ACTIVE WEATHER TODAY WITH HIGH WINDS AND EXTREME FIRE
WEATHER CONDITIONS.
LOW PRESSURE APPROACHING 995 MB WILL TRACK EASTWARD NEAR THE
KANSAS BORDER DURING THE DAYLIGHT HOURS...WHILE A COMPACT MID
LEVEL JET MAX EJECTS SOUTH OF THE SURFACE LOW ACROSS OKLAHOMA AND
NORTH TEXAS. THIS SCENARIO OFTEN LEADS TO SEVERE WIND GUSTS EVEN
IN MID WINTER.
THERE ARE TWO NOTEWORTHY SURFACE BOUNDARIES. A PACIFIC FRONT WILL
REACH INTERSTATE 35 BY NOON TO 1 PM AND CONTINUE EASTWARD.
ALTHOUGH THE LOW LEVEL JET WILL MAKE FOR A BREEZY MORNING...THE
WIND WILL INCREASE MARKEDLY BEHIND THE PACIFIC FRONT...WHERE DEEP
MIXING WILL OCCUR. WE EXPANDED THE WIND ADVISORY TO ACCOUNT FOR
THIS. MEANWHILE...A SECOND COLD FRONT EMANATING FROM THE
ROCKIES/HIGH PLAINS WILL DIVE INTO WESTERN OK AND WESTERN NORTH TX
THIS AFTERNOON. TRENDS IN THE NAM AND RUC SUGGEST GUSTS ABOVE 50
OR 60 MPH WILL OCCUR WITH THIS FRONT...AND WE HAVE ISSUED A HIGH
WIND WARNING FOR PORTIONS OF WESTERN OKLAHOMA.
THE RUC ALSO SUGGESTS HIGH WIND CRITERIA COULD BE MET OVER FAR
WESTERN NORTH TEXAS BENEATH THE MID LEVEL JET...AND EVEN PRIOR TO
THE ARRIVAL OF THE SECOND...STRONGER FRONT. WE WERE NOT QUITE
CONVINCED BECAUSE MOST OF THE COLD ADVECTION BEHIND THE PACIFIC
FRONT OCCURS PRIOR TO DEEP MIXING IN THAT AREA...AND THE TIGHTER
GRADIENTS ASSOCIATED WITH THE SECOND FRONT WILL PASS NORTH THROUGH
OKLAHOMA. THE DAY SHIFT MAY NEED TO EXPAND THE HIGH WIND WARNING
INTO TEXAS IF THE OBSERVATIONS SUGGEST IT IS NEEDED. WE ADJUSTED
THE RED FLAG WARNING BASED ON THE HUMIDITY FORECAST...ADDING ONLY
CLAY COUNTY.
THE WIND WILL QUIET DOWN BY MONDAY MORNING...AND WE GO BACK TO OUR
ACTIVE WESTERLY JET ALOFT WITH SEASONABLE OR RELATIVELY MILD
TEMPERATURES FOR THE WEEK AHEAD. THE JET WILL BUCKLE ENOUGH FOR A
CLOSED LOW TO PRODUCE RAIN OVER TEXAS AND OKLAHOMA MID
WEEK...BEFORE IT IS RE-ABSORBED IN THE FLOW. IT HAS BEEN DIFFICULT
THIS WINTER TO PREDICT EXACTLY WHERE THE LOW WILL CLOSE OFF...AND
HOW QUICKLY IT WILL BE RE-ABSORBED. IT DOES LOOK...THOUGH...AS IF
THERE IS A FAIRLY GOOD CHANCE OF SOME RAIN ACCUMULATION TUESDAY
NIGHT AND EARLY WEDNESDAY FROM NORTH TEXAS INTO SOUTHERN OKLAHOMA.
THE OPERATIONAL MODEL SOLUTIONS WOULD BRING GREATER RAIN COVERAGE
AND AMOUNTS FARTHER NORTHWARD INTO OKLAHOMA...BUT WE DID NOT
COMMIT IN THAT DIRECTION...AS THE OPERATIONAL RUNS ARE QUITE A BIT
FARTHER NORTH THEN THE VAST MAJORITY OF THE GFS ENSEMBLE MEMBERS.
THE NEXT SHOT OF COLDER WEATHER IS EXPECTED EARLY NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 30 57 35 / 10 0 0 0
HOBART OK 64 31 58 34 / 0 0 0 0
WICHITA FALLS TX 69 34 62 39 / 0 0 0 0
GAGE OK 59 23 54 25 / 20 0 0 0
PONCA CITY OK 62 29 55 31 / 10 10 0 0
DURANT OK 70 39 61 40 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR OKZ007-008-012-013-018>020-023>030-036>038-044.
HIGH WIND WARNING FROM 11 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR OKZ004>006-009>011-014>017-021-022-033>035.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
OKZ031-032-039>042-045-046-050.
TX...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR TXZ083>089.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
TXZ090.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
26/22
BURKE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
541 AM CST SUN JAN 22 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
230 AM CST SUN JAN 22 2012
FREEZING DRIZZLE IS THE FORECAST FOCUS TODAY/TONIGHT...WITH A NEED
FOR HEADLINES.
LATEST WATER VAPOR IMAGERY POINTED TO AN UPPER LEVEL TROUGH/SHORTWAVE
ENERGY MOVING EAST OUT OF THE DESERT SOUTHWEST. THE TROUGH WILL
TRACK OVER THE PLAINS...THEN CURVE NORTHEAST ACROSS THE GREAT
LAKES FOR TONIGHT/MON MORNING. THIS HAS BEEN A CONSISTENT SIGNAL IN
THE MODELS...ALTHOUGH THE TIMING AND POSITION OF THE SYSTEM HAS NOT.
HOWEVER...22.00Z RUNS STARTING TO SHOW MORE AGREEMENT WITH THE EC
AND GEM...DRIVING THE SYSTEM/S SFC LOW TO LOT BY 12Z SUN...WHILE THE
GFS IS SHIFTED A BIT FARTHER NORTH INTO SOUTHCENTRAL WI. THE NAM HAS
BEEN THE ODD MODEL OUT...BUT ITS RECENT RUN IS STARTING TO TREND
TOWARD THE SLOWER SOLUTIONS...ALTHOUGH STILL OVER NORTHERN WI BY 12Z
MON. GIVEN THE CONSISTENCY OF THE EC...WILL CONTINUE TO FAVOR THIS
SOLUTION...BLENDING IN THE GEM/GFS.
MAIN CONCERN WITH THIS SYSTEM IS THE POTENTIAL FOR FREEZING DRIZZLE.
NORTHWEST-SOUTHEAST X-SECTIONS AND BUFKIT SOUNDINGS CONTINUE TO SHOW
ONLY A LOW SATURATION IN PLACE INTO THIS EVENING...GENERALLY BELOW
850 MB. GOOD LOW LEVEL WARMING IN THE 925-850 MB LAYER ALONG WITH
ISENTROPIC UPGLIDE ALONG THE 275-290 K SFCS. RUC13 BUFKIT SOUNDINGS
SHOW A DECENT AMOUNT OF UPWARD OMEGA IN THE SATURATED LAYER THROUGH
THIS EVENING WHILE THE X-SECTIONS VIA THE GFS40 AND RUC13 POINT TO
SOME FRONTOGENETIC LIFT ALONG THE TOP OF THE SATURATED LAYER. ALL
MODELS SHOW SOME LIGHT QPF DEVELOPING BY AT LEAST THE AFTERNOON FOR
THE FORECAST AREA....PERSISTING INTO THE EVENING AND THEN INCREASING
TONIGHT AS THE SHORTWAVE TROUGH/SFC LOW MOVES IN. BEFORE THAT
THOUGH...THE EXPECTED LOW CLOUDS WILL LACK ANY ICE...THUS MAKING ANY
PCPN THE LIFT CAN SQUEEZE OUT OF THEM LIQUID...AND EITHER FREEZING
DRIZZLE OR DRIZZLE...SFC TEMP DEPENDENT. THAT SAID...WITH TEMPS
EXPECTED TO WARM INTO THE EARLY EVENING THANKS TO THE STRONG WARM
AIR ADVECTIVE SIGNAL...GROUND TEMPS WILL LIKELY STILL STAY BELOW
FREEZING DUE TO THE SEVERAL DAYS OF COLD CONDITIONS. SO...FREEZING
COULD STILL RESULT ON UNTREATED ROADS AND OTHER EXPOSED SFCS EVEN IF
THE AIR TEMP RISES ABOVE FREEZING.
WITH ALL THIS IN MIND...FEEL THE THREAT FOR AREAS OF FREEZING
DRIZZLE IS HIGH ENOUGH FOR A FREEZING RAIN ADVISORY TODAY INTO THIS
EVENING. SOUNDINGS AND X-SECTIONS DON/T REALLY DISCRIMINATE TOO MUCH
BETWEEN WHERE THE CHANCES WOULD BE BEST...SO WILL GO WITH THE ENTIRE
FORECAST AREA. THE AFTERNOON INTO EARLY EVENING WOULD APPEAR TO BE
THE MAIN THREAT TIME...BUT CAN/T RULE OUT PERIODS OF FREEZING
DRIZZLE THIS MORNING...SO WILL START IT EARLY.
THE SATURATION DEEPENS OVERNIGHT ENOUGH THAT ICE WOULD BE INTRODUCED
INTO THE CLOUD...AND SNOW BECOMES THE PCPN TYPE. THIS CORRESPONDS
WITH THE APPROACH OF THE UPPER LEVEL TROUGH/SFC LOW...AND BETTER
UPPER LEVEL FORCING. QPF INCREASES IN THE MODELS AS A RESULT...AND
SOME MINOR SNOW ACCUMULATIONS ARE PROBABLE. WHILE ITS BELIEVED THE
EC HAS THE BEST HANDLE ON THIS SYSTEM AT THIS TIME...ITS DEFORMATION
PCPN REGION LIES ON TOP OF ITS SFC LOW. MEANWHILE THE GFS AND GEM IS
DISPLACED A BIT MORE NORTH-WEST OF THE LOW TRACK...AND SEEMS MORE
REASONABLE. WILL TREND THE SNOW CHANCES THIS WAY OVERNIGHT. WILL GO
WITH 1 TO 3 INCHES OF SNOW ACCUMULATION...WITH THE HIGHER AMOUNTS
MORE LIKELY NORTH OF I-94.
SNOW WILL GRADUALLY SHIFT NORTHEAST AS THE LOW PRESSURE SYSTEM
SHIFTS INTO SOUTHEAST CANADA. IT WILL BE A WINDY DAY WITH AN
INCREASING SFC PRESSURE GRADIENT POST THE LOW. IN ADDITION...COLD
AIR ADVECTION WILL RESULT IN STEADY OF SLOWLY FALLING TEMPERATURES.
MONDAY/S HIGH WILL LIKELY BE DURING THE EARLY MORNING HOURS.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
230 AM CST SUN JAN 22 2012
FAIRLY ACTIVE NEARLY ZONAL UPPER LEVEL FLOW WILL PERSIST INTO THE
UPCOMING WEEKEND...SPINNING SEVERAL SHORTWAVE TROUGHS ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY. HOWEVER...BOTH THE GFS AND ECMWF
KEEP THE BULK OF ANY ASSOCIATED PCPN ACROSS NORTHERN PORTIONS OF THE
REGION. SO OVERALL...IT LOOKS FAIRLY DRY THROUGH THE PERIOD...WITH
THE BETTER...ALBEIT SMALL SNOW CHANCES...ACROSS THE NORTH.
TEMPERATURES SHOULD BE AT OR ABOVE THE SEASONABLE NORMALS.
&&
.AVIATION...TODAY AND TONIGHT
541 AM CST SUN JAN 22 2012
STRONG SOUTH/SOUTHEAST FLOW WAS IN PLACE ACROSS THE REGION AHEAD
OF STRENGTHENING LOW PRESSURE OVER THE PLAINS. THIS WAS ADVECTING
MOISTURE AND LOW-LEVEL MVFR/IFR STRATUS AND FOG INTO THE AREA. AS
THIS FLOW CONTINUES THIS MORNING...EXPECTING DRIZZLE/FREEZING DRIZZLE TO
BECOME WIDESPREAD ALONG WITH CIG/VIS LOWERING INTO IFR/LIFR
CATEGORY. LOOK FOR THESE CONDITIONS TO PERSIST THROUGH TODAY AND
INTO THIS EVENING AS LOW PRESSURE TRACKS TOWARD NORTHEAST
IA/SOUTHERN WI. AS THE LOW PULLS FARTHER EAST INTO EASTERN WI
AFTER MIDNIGHT...LOOK FOR THE PRECIPITATION TO CHANGE OVER TO SNOW
WITH CIGS/VIS REMAINING IN IFR/LIFR CATEGORY. RIGHT NOW IT APPEARS
AROUND A TENTH OF AN INCH OF ICE ACCUMULATION IS POSSIBLE WITH
SNOW ACCUMULATIONS AFTER MIDNIGHT TO AROUND SUNRISE OF ABOUT AN
INCH. BLUSTERY WEST/NORTHWEST WINDS WILL BEE SEEN ON MONDAY AS THE
DEEPENING LOW PULLS INTO UPPER MICHIGAN. ACCUMULATING SNOW STILL
LIKELY INTO MONDAY MORNING BEHIND THE LOW IN ADDITION TO THE
WIND. WILL HAVE TO WATCH THIS CLOSELY FOR FLIGHT OPERATION
IMPACTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 AM CST SUN JAN 22 2012
WI...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR WIZ017-029-032>034-041>044-053>055-061.
MN...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR MNZ079-086>088-094>096.
IA...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1026 AM MST SUN JAN 22 2012
.UPDATE...TO REMOVE WINTER WEATHER HEADLINES FOR THE NORTHWEST
COLORADO PLATEAUS. SNOWFALL CONTINUES OVER THE HIGHER ELEVATIONS
OF THE COLORADO NORTHERN AND CENTRAL MOUNTAINS.
&&
.SHORT TERM /REST OF TODAY THROUGH MONDAY NIGHT/...
COLD FRONT WAS WORKING THROUGH THE SOUTHERN ZONES THIS MORNING AS
THE UPPER TROUGH WAS SHIFTING EAST OF THE FORECAST AREA. Q
CONVERGENT FILED WILL BE EAST OF THE DIVIDE BY SUNRISE SIGNALING AN
END TO DYNAMICAL SUPPORT...BUT MOIST COLD ADVECTION IN NW OROGRAPHIC
FLOW WILL CONTINUE TO PRODUCE SNOWFALL THIS MORNING IN THE COLORADO
MOUNTAINS AND HIGH VALLEYS. THE LATEST HRRR AND RUC MODELS ARE
EMPHASIZING MORNING SNOW OVER THE CENTRAL COLORADO MTNS ESPECIALLY
THE NW SAN JUANS. HEAVY WET SNOW FELL SATURDAY INTO THE EVENING BUT
QUICKLY DROPPING MOUNTAIN TEMPERATURES ARE PRODUCING HIGHER RATIO
FLUFFY SNOW THIS MORNING FOR RIGHT-SIDE-UP SNOW CONDITIONS. THE
VALLEYS HAVE STAYED SURPRISINGLY MILD AND ONLY FLIRTING WITH
FREEZING LIMITING SNOW ACCUMULATIONS IN THE CENTRAL AND SOUTHERN
VALLEYS.
SUN COMES OUT THIS AFTERNOON FOR MOST LOCATIONS AS NW GRADIENT
WINDS RELAX SOMEWHAT. LIGHT SHOWERS EXPECTED TO CONTINUE THIS
AFTERNOON IN THE EASTERN PORTION OF THE FORECAST AREA. LOW LEVEL
MOISTURE NEVER FULLY ERODES UNDER WEAK RIDGING TONIGHT INTO
MONDAY. THE NEXT SPLITTING STORM COMES ONSHORE ON MONDAY WITH THE
BRUNT OF DYNAMICS DIGGING THROUGH SOUTHERN AZ MONDAY NIGHT.
SNOWFALL WILL INCREASE OVER NORTH FACING SLOPES...BUT ACCUMULATIONS
ARE EXPECTED TO BE LIGHT.
.LONG TERM /TUESDAY THROUGH SATURDAY/...
SPLITTING TROUGH HEADED ACROSS THE GREAT BASIN WILL BE SENDING
ENERGY NORTH AND SOUTH OF THE FORECAST AREA AS WE START OFF THIS
PERIOD. BEST MOISTURE AND FORCING APPEARS TO BE OVER THE SAN JUANS
WITH THIS STORM...BUT AMOUNTS LOOKING MORE AND MORE MEAGER WITH
EACH RUN. SHOULD SEE A FEW INCHES OF NEW SNOW...BUT MAY NOT EVEN
REACH ADVISORY CRITERIA. WILL JUST MAINTAIN THE HIGH CHANCE TO LOW
LIKELY POPS WE CURRENTLY HAVE RUNNING. THIS SYSTEM EXITS TUESDAY
NIGHT...WITH FLAT DIRTY RIDGE LEFT IN ITS WAKE. THE FLAT RIDGING
WILL KEEP THE MAJORITY OF THE FORECAST AREA DRY...WITH THE EXCEPTION
BEING THE NORTHERN MOUNTAINS WHERE OCCASIONAL WEAK WAVES PASS...
SQUEEZING OUT A FEW SNOW SHOWERS. NO SIGNIFICANT ACCUMULATIONS
EXPECTED THROUGH THURSDAY ACROSS OUR FORECAST AREA. THAT LOOKS TO
CHANGE BY FRIDAY AS BOTH THE ECMWF AND GFS ADVERTISING ANOTHER
STRONG PACIFIC SYSTEM TO SLIDE SOUTHEAST ACROSS THE GREAT BASIN AND
INTO WESTERN COLORADO AS HEIGHTS RISE ALONG THE WEST COAST. THIS
COULD BRING ANOTHER ROUND OF MORE SIGNIFICANT PRECIP...FAVORING THE
NORTHERN AND CENTRAL MOUNTAINS. FOR NOW...WILL JUST RAMP UP POPS
SLIGHTLY. TEMPS REMAIN SEASONAL THROUGH THIS PERIOD.
&&
.AVIATION /FOR 18Z TAF ISSUANCE/...
CLOUDS AND SHOWERS ARE DECREASING THIS MORNING ACROSS THE
REGION...HOWEVER ENOUGH LINGERING MOISTURE AND INSTABILITY WILL
LEAD TO BRIEF LOCAL MVFR TO IFR CONDITIONS. OTHERWISE VFR CONDITIONS
ARE EXPECTED OVER THE ENTIRE FORECAST AREA...ALTHOUGH MOUNTAIN
OBSCURATION WILL LINGER OVER THE HIGHER PEAKS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL NOON MST TODAY FOR ZONES 004-009-010-
012.
UT...NONE.
&&
$$
UPDATE.......CJC
SHORT TERM...JDC
LONG TERM....JDC
AVIATION.....MC
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
943 AM MST SUN JAN 22 2012
.SHORT TERM /REST OF TODAY THROUGH MONDAY NIGHT/...
COLD FRONT WAS WORKING THROUGH THE SOUTHERN ZONES THIS MORNING AS
THE UPPER TROUGH WAS SHIFTING EAST OF THE FORECAST AREA. Q
CONVERGENT FILED WILL BE EAST OF THE DIVIDE BY SUNRISE SIGNALING AN
END TO DYNAMICAL SUPPORT...BUT MOIST COLD ADVECTION IN NW OROGRAPHIC
FLOW WILL CONTINUE TO PRODUCE SNOWFALL THIS MORNING IN THE COLORADO
MOUNTAINS AND HIGH VALLEYS. THE LATEST HRRR AND RUC MODELS ARE
EMPHASIZING MORNING SNOW OVER THE CENTRAL COLORADO MTNS ESPECIALLY
THE NW SAN JUANS. HEAVY WET SNOW FELL SATURDAY INTO THE EVENING BUT
QUICKLY DROPPING MOUNTAIN TEMPERATURES ARE PRODUCING HIGHER RATIO
FLUFFY SNOW THIS MORNING FOR RIGHT-SIDE-UP SNOW CONDITIONS. THE
VALLEYS HAVE STAYED SURPRISINGLY MILD AND ONLY FLIRTING WITH
FREEZING LIMITING SNOW ACCUMULATIONS IN THE CENTRAL AND SOUTHERN
VALLEYS.
SUN COMES OUT THIS AFTERNOON FOR MOST LOCATIONS AS NW GRADIENT
WINDS RELAX SOMEWHAT. LIGHT SHOWERS EXPECTED TO CONTINUE THIS
AFTERNOON IN THE EASTERN PORTION OF THE FORECAST AREA. LOW LEVEL
MOISTURE NEVER FULLY ERODES UNDER WEAK RIDGING TONIGHT INTO
MONDAY. THE NEXT SPLITTING STORM COMES ONSHORE ON MONDAY WITH THE
BRUNT OF DYNAMICS DIGGING THROUGH SOUTHERN AZ MONDAY NIGHT.
SNOWFALL WILL INCREASE OVER NORTH FACING SLOPES...BUT ACCUMULATIONS
ARE EXPECTED TO BE LIGHT.
.LONG TERM /TUESDAY THROUGH SATURDAY/...
SPLITTING TROUGH HEADED ACROSS THE GREAT BASIN WILL BE SENDING
ENERGY NORTH AND SOUTH OF THE FORECAST AREA AS WE START OFF THIS
PERIOD. BEST MOISTURE AND FORCING APPEARS TO BE OVER THE SAN JUANS
WITH THIS STORM...BUT AMOUNTS LOOKING MORE AND MORE MEAGER WITH
EACH RUN. SHOULD SEE A FEW INCHES OF NEW SNOW...BUT MAY NOT EVEN
REACH ADVISORY CRITERIA. WILL JUST MAINTAIN THE HIGH CHANCE TO LOW
LIKELY POPS WE CURRENTLY HAVE RUNNING. THIS SYSTEM EXITS TUESDAY
NIGHT...WITH FLAT DIRTY RIDGE LEFT IN ITS WAKE. THE FLAT RIDGING
WILL KEEP THE MAJORITY OF THE FORECAST AREA DRY...WITH THE EXCEPTION
BEING THE NORTHERN MOUNTAINS WHERE OCCASIONAL WEAK WAVES PASS...
SQUEEZING OUT A FEW SNOW SHOWERS. NO SIGNIFICANT ACCUMULATIONS
EXPECTED THROUGH THURSDAY ACROSS OUR FORECAST AREA. THAT LOOKS TO
CHANGE BY FRIDAY AS BOTH THE ECMWF AND GFS ADVERTISING ANOTHER
STRONG PACIFIC SYSTEM TO SLIDE SOUTHEAST ACROSS THE GREAT BASIN AND
INTO WESTERN COLORADO AS HEIGHTS RISE ALONG THE WEST COAST. THIS
COULD BRING ANOTHER ROUND OF MORE SIGNIFICANT PRECIP...FAVORING THE
NORTHERN AND CENTRAL MOUNTAINS. FOR NOW...WILL JUST RAMP UP POPS
SLIGHTLY. TEMPS REMAIN SEASONAL THROUGH THIS PERIOD.
&&
.AVIATION /FOR 18Z TAF ISSUANCE/...
CLOUDS AND SHOWERS ARE DECREASING THIS MORNING ACROSS THE
REGION...HOWEVER ENOUGH LINGERING MOISTURE AND INSTABILITY WILL
LEAD TO BRIEF LOCAL MVFR TO IFR CONDITIONS. OTHERWISE VFR CONDITIONS
ARE EXPECTED OVER THE ENTIRE FORECAST AREA...ALTHOUGH MOUNTAIN
OBSCURATION WILL LINGER OVER THE HIGHER PEAKS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL NOON MST TODAY FOR ZONES 002>005-
008>010-012-013.
UT...NONE.
&&
$$
SHORT TERM...CC
LONG TERM....CC
AVIATION.....MC
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1152 AM CST SUN JAN 22 2012
.DISCUSSION...
ISSUED 1015 AM CST SUN JAN 22 2012
AS WARM/MOIST AIR FLOWS NORTHWARD OVER THE COLD GROUND...WIDESPREAD
DRIZZLE AND FOG HAVE DEVELOPED ACROSS CENTRAL ILLINOIS THIS MORNING.
12Z KILX UPPER AIR SOUNDING REVEALS A VERY STRONG LOW-LEVEL
INVERSION AT AROUND 900MB...ESSENTIALLY TRAPPING MOISTURE NEAR THE
SURFACE. WITH FORECAST SOUNDINGS SHOWING THIS INVERSION REMAINING
IN PLACE...DRIZZLE AND FOG WILL PERSIST THROUGHOUT THE DAY. 12Z
NAM AND HRRR BOTH SHOW MOSTLY DRY CONDITIONS TODAY...WITH
SHOWERS/STORMS DEVELOPING ALONG AN ADVANCING COLD FRONT BETWEEN
00Z AND 03Z. THERE IS SOME HINT THAT INCREASING SYNOPTIC LIFT
AHEAD OF THE APPROACHING UPPER TROUGH WILL TRIGGER A FEW LIGHT
RAIN SHOWERS AS EARLY AS THIS AFTERNOON...HOWEVER THE STRONGEST
LIFT WILL HOLD OFF UNTIL EVENING. HAVE UPDATED THE FORECAST TO
INCLUDE DRIZZLE AND FOG THROUGH THE AFTERNOON AND TO MENTION JUST
A SLIGHT CHANCE FOR A SHOWER LATER IN THE DAY. HAVE ALSO ADDED
SEVERE MENTION TO AREAS ALONG AND SOUTH OF I-70 FOR THIS
EVENING...AS LATEST DAY 1 OUTLOOK FROM SPC PLACES THIS AREA UNDER
A MODERATE RISK FOR SEVERE.
&&
.AVIATION...
ISSUED 1152 AM CST SUN JAN 22 2012
LIFR CONDITIONS WILL PERSIST AT THE TERMINALS FOR THE NEXT COUPLE
OF HOURS...BEFORE CEILINGS GRADUALLY IMPROVE INTO THE IFR CATEGORY
LATER THIS AFTERNOON/EVENING. A FEW SHOWERS MAY DEVELOP AROUND THE
AREA THIS AFTERNOON AS WELL...HOWEVER STRONGEST LIFT ASSOCIATED
WITH APPROACHING COLD FRONT WILL NOT ARRIVE UNTIL EVENING. BASED
ON LATEST MODEL DATA...IT APPEARS A LINE OF THUNDERSTORMS WILL
DEVELOP ALONG THE I-55 CORRIDOR AROUND 02Z...THEN WILL TRACK
EASTWARD INTO INDIANA SHORTLY AFTER 06Z. HAVE THEREFORE INCLUDED A
TEMPO GROUP FOR THUNDER AT KBMI...KSPI...AND KDEC BETWEEN 03Z AND
05Z AND BETWEEN 04Z AND 06Z AT KCMI. ONCE THE FRONT SWINGS
THROUGH...WINDS WILL VEER TO THE SOUTH OVERNIGHT...THEN TO THE
SOUTHWEST BY MONDAY MORNING. WITH DRIER AIR TRYING TO MOVE IN FROM
THE SOUTHWEST...HAVE IMPROVED CEILINGS INTO THE MVFR CATEGORY AT
THE I-72 TERMINALS AFTER 11Z. FURTHER NORTHWEST...LOWER CLOUDS
WILL LINGER AT BOTH KPIA AND KBMI THROUGH THE REMAINDER OF THE 18Z
TAF PERIOD.
BARNES
&&
.PREV DISCUSSION...
ISSUED 330 AM CST SUN JAN 22 2012
BIGGEST FORECAST CONCERN IS SLIGHT RISK OF SEVERE THUNDERSTORMS
THIS EVENING OVER SE IL. WILL USE A BLEND OF THE 00Z MODELS FOR
THIS FORECAST PACKAGE AND MODELS HAVE TRENDED SLOWER WITH STRONG
LOW PRESSURE AND COLD FRONT TONIGHT. NEXT WEATHER SYSTEM TO AFFECT
SE IL WED NIGHT. OTHERWISE MOST OF THE UPCOMING WORK WEEK EXPECTED
TO HAVE QUIETER WEATHER WITH ABOVE NORMAL TEMPERATURES AS SPLIT
UPPER LEVEL FLOW TAKES SHAPE AGAIN OVER THE COUNTRY DURING MID AND
LATE WEEK.
SHORT TERM...TODAY THROUGH TUESDAY NIGHT
LOW STRATUS CLOUDS AROUND 500 FT OR LESS HAVE DRIFTED NORTHWARD IN
SE LOW LEVEL FLOW OVER IL ALONG WITH SOME FOG ESPECIALLY FROM I-70
NORTH WHERE VISIBILITIES 1-3 MILES. TEMPERATURES SLOWLY INCREASING
IN THE 20S EARLY THIS MORNING WITH COOLEST READINGS OVER THE 1-2
INCH SNOW COVER FROM I-74 NORTH. 1033 MB HIGH PRESSURE WAS OVER
NEW ENGLAND WHILE STRONG 986 MB LOW PRESSURE WAS OVER THE EASTERN
CO/WY BORDER.
LATEST SHORT RANGE MODELS HAVE BACKED OFF ON QPF THIS AFTERNOON AS
MODELS INDICATE LIFT IN WARM AIR ADVECTION PATTERN WILL BE RATHER
DISORGANIZED. PLUS MOST OF THE SATURATED CONDITIONS ARE IN THE
LOWER LEVELS. SO ONLY EXPECTING ISOLATED LIGHT RAIN SHOWERS OR
SPRINKLES/DRIZZLE TO DEVELOP DURING TODAY. TEMPS INTO MID MORNING
STILL BELOW FREEZING WITH PATCHY FREEZING DRIZZLE POSSIBLE NORTH
OF I-70. GUIDANCE HAS TRENDED COOLER ON DAYTIME HIGHS TODAY
REACHED AT 00Z/6 PM IN THE LOWER 40S FROM I-74 NORTH AND AROUND 50F
IN SE IL. TEMPS WILL LIKELY CLIMB AHEAD OF APPROACHING STRONG COLD
FRONT FROM THE WEST THIS EVENING INTO THE UPPER 40S AND LOWER 50S.
CONTINUE HIGH CHANCES OF SHOWERS THIS EVENING WITH THUNDERSTORMS
POSSIBLE EAST OF THE IL RIVER WITH STRONG SURFACE LOW MOVING NE
INTO SE IA BY MIDNIGHT TONIGHT AND DEEPENING INTO SE WI BY DAWN
TUE. SHOWERS DIMINISH QUICKLY BEHIND THE COLD FRONT AND LINGERING
NEAR THE INDIANA BORDER EARLY OVERNIGHT. THEN WRAP AROUND LIGHT
RAIN CHANGING TO LIGHT SNOW MOVES INTO THE IL RIVER VALLEY LATER
TONIGHT AND CONTINUE SMALL CHANCE OF LIGHT SNOW AND FLURRIES OVER
NE COUNTIES MON MORNING MAINLY FROM I-74 NE.
SPC CONTINUES A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING
SE OF I-70 WITH YET ANOTHER COOL SEASON SEVERE WX THREAT IMPACTING
THIS PART OF IL LIKE LAST MONDAY NIGHT. A MODERATE RISK FURTHER
SOUTH OVER WEST TN...EASTERN AR AND NORTHERN MS. PER SPC DAY 1
OUTLOOK FOR THIS EVENING...A POWERFUL UPPER LEVEL TROUGH OVER THE
ROCKIES WILL MOVE EAST INTO THE MS VALLEY THIS EVENING. THE TROUGH
WILL BECOME NEGATIVELY- TILTED AS AN UPPER LEVEL LOW CLOSES OFF
OVER THE UPPER MIDWEST. AHEAD OF THE SYSTEM...A 50 TO 70 KT LOW
LEVEL JET WILL EXPAND NORTHWARD ACROSS THE MID MS VALLEY TODAY
WITH STRONG MOISTURE ADVECTION TAKING PLACE IN THE LOWER MS
VALLEY. A POWERFUL UPPER LEVEL TROUGH WILL MOVE ACROSS THE OZARK
PLATEAU EARLY THIS EVENING AS NUMEROUS THUNDERSTORMS INITIATE IN
THE MID MS VALLEY. VERY STRONG LARGE SCALE ASCENT ASSOCIATED WITH
THE UPPER LEVEL TROUGH AND UNIDIRECTIONAL WIND PROFILES EVIDENT ON
FORECAST SOUNDINGS SHOULD RESULT IN RAPID LINEAR DEVELOPMENT THIS
EVENING FROM EASTERN/SE IL SOUTHWARD INTO WESTERN KY. A WIND
DAMAGE THREAT SHOULD DEVELOP AS THE LINE SURGES QUICKLY EWD ACROSS
THE OH VALLEY DURING THE MID TO LATE EVENING. FORECAST SOUNDINGS
ACROSS MUCH OF THE OH VALLEY DURING THE 03Z TO 06Z TIMEFRAME
SUGGEST THAT A COOL SURFACE INVERSION WILL EXIST IN SPITE OF
STRONG MOISTURE ADVECTION. FOR THIS REASON...THE TORNADO THREAT IS
EXPECTED TO REMAIN MARGINAL EXCEPT IN SOUTHERN KY WHERE SFC
DEWPOINTS COULD APPROACH 60F.
INCREASED THE WINDS MONDAY WITH VERY TIGHT PRESSURE GRADIENT OVER
CENTRAL IL FROM DEEPENING LOW PRESSURE DEPARTING TO THE NE. TEMPS
WILL LIKELY SLIP DURING MONDAY MORNING WITH NOT MUCH RECOVERY
MONDAY AFTERNOON. CLOUDS DECREASE OVER SW AREAS MONDAY AFTERNOON
AND REST OF AREA MONDAY EVENING. WEAK HIGH PRESSURE OF 1023 MB
MOVES INTO KY/TN BY DAWN TUE AND RIDGES OVER IL DURING TUE. THIS
TO BRING FAIR WX MONDAY NIGHT AND TUE AS WINDS DIMINISH AND CLOUDS
DECREASE.
LONG TERM...WEDNESDAY THROUGH SATURDAY
00Z ECMWF MODEL HAS TRENDED FURTHER NORTH WITH QPF INTO CENTRAL
AND SE IL WED AFTERNOON THROUGH THU WHILE 00Z GFS SHOWS QPF OVER
JUST SE IL WED NIGHT WHICH CURRENT FORECAST AND ALLBLEND REFLECTS.
00Z GEM MODELS MAINLY KEEPS CENTRAL AND SE IL DRY DURING THIS TIME.
SPLIT UPPER LEVEL FLOW STILL PROJECTED DURING MID AND LATE WEEK
WITH STRONGER SOUTHERN STREAM SYSTEM/CUTOFF LOW TO STAY SOUTH OF
IL AND GETS ITS QPF CLOSEST TO SE IL WED NIGHT. DID NOT FOLLOW
ECMWF MODEL SINCE IT WAS A SHIFT FROM ITS PREVIOUS RUNS AND NOT IN
GOOD AGREEMENT WITH OTHER EXTENDED MODELS. WEAKER NORTHERN STREAM
TO KEEPS ITS LIGHT SNOW CHANCES NORTH OF CENTRAL IL OVER THE GREAT
LAKES. TEMPS OVERALL STILL APPEAR TO AVERAGE ABOVE NORMAL DURING
THIS TIME PERIOD.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1015 AM CST SUN JAN 22 2012
.DISCUSSION...
ISSUED 1015 AM CST SUN JAN 22 2012
AS WARM/MOIST AIR FLOWS NORTHWARD OVER THE COLD GROUND...WIDESPREAD
DRIZZLE AND FOG HAVE DEVELOPED ACROSS CENTRAL ILLINOIS THIS MORNING.
12Z KILX UPPER AIR SOUNDING REVEALS A VERY STRONG LOW-LEVEL
INVERSION AT AROUND 900MB...ESSENTIALLY TRAPPING MOISTURE NEAR THE
SURFACE. WITH FORECAST SOUNDINGS SHOWING THIS INVERSION REMAINING
IN PLACE...DRIZZLE AND FOG WILL PERSIST THROUGHOUT THE DAY. 12Z
NAM AND HRRR BOTH SHOW MOSTLY DRY CONDITIONS TODAY...WITH
SHOWERS/STORMS DEVELOPING ALONG AN ADVANCING COLD FRONT BETWEEN
00Z AND 03Z. THERE IS SOME HINT THAT INCREASING SYNOPTIC LIFT
AHEAD OF THE APPROACHING UPPER TROUGH WILL TRIGGER A FEW LIGHT
RAIN SHOWERS AS EARLY AS THIS AFTERNOON...HOWEVER THE STRONGEST
LIFT WILL HOLD OFF UNTIL EVENING. HAVE UPDATED THE FORECAST TO
INCLUDE DRIZZLE AND FOG THROUGH THE AFTERNOON AND TO MENTION JUST
A SLIGHT CHANCE FOR A SHOWER LATER IN THE DAY. HAVE ALSO ADDED
SEVERE MENTION TO AREAS ALONG AND SOUTH OF I-70 FOR THIS
EVENING...AS LATEST DAY 1 OUTLOOK FROM SPC PLACES THIS AREA UNDER
A MODERATE RISK FOR SEVERE.
BARNES
&&
.AVIATION...
ISSUED 548 AM CST SUN JAN 22 2012...FOR THE 12Z TAFS
VLIFR CONDITIONS WILL CONTINUE AT BMI THRU AT LEAST 15Z...AND
POSSIBLY UNTIL 17Z...WHEN THE WARM FRONT LIFTS NORTH AND HELPS TO
INCREASE THE LIFTED CONDENSATION LEVEL. THE OTHER TERMINALS WILL
BE LIFR DUE TO CLOUDS AND/OR VIS THROUGH THE MORNING AS WELL... OR
UNTIL THE WARM FRONT LIFTS NORTH BETWEEN 15Z AND 18Z. THE PASSAGE
OF THE WARM FRONT WILL NOT CHANGE WIND DIRECTIONS MUCH...AS
SOUTHEAST WINDS CONTINUE THRU THE DAY AT 15 TO 20 GUSTING NEAR
30KT.
RAIN AND STORMS WILL DEVELOP LATE THIS AFTERNOON AND THIS
EVENING...AS A COLD FRONT MOVES EAST ACROSS THE AREA. THE BEST
CHANCE OF SHOWERS AND STORMS WILL BE FOR THE EASTERN TERMINALS OF
CMI/DEC...WITH SPI/BMI MORE MARGINAL AND PIA THE LOWEST CHANCES.
THE TERMINALS MAY ALL LIFT TO IFR FOR A SHORT TIME THIS
AFTERNOON...BEFORE CLOUD LEVELS DROP TO LIFR AGAIN AHEAD OF THE
COLD FRONT. ANY STORMS THAT DO AFFECT DEC/CMI MAY CONTAIN VERY
STRONG WINDS NEAR 50KT. HOWEVER...CHANCES FOR THOSE WINDS ARE
BETTER SOUTH OF I-70 WITH THE HIGHER SEVERE STORM CHANCES.
WINDS WILL VEER TO THE SOUTHWEST AFTER MIDNIGHT...AS COLDER AIR
BEGINS TO MAKE A RETURN TO CENTRAL IL.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 330 AM CST SUN JAN 22 2012
BIGGEST FORECAST CONCERN IS SLIGHT RISK OF SEVERE THUNDERSTORMS
THIS EVENING OVER SE IL. WILL USE A BLEND OF THE 00Z MODELS FOR
THIS FORECAST PACKAGE AND MODELS HAVE TRENDED SLOWER WITH STRONG
LOW PRESSURE AND COLD FRONT TONIGHT. NEXT WEATHER SYSTEM TO AFFECT
SE IL WED NIGHT. OTHERWISE MOST OF THE UPCOMING WORK WEEK EXPECTED
TO HAVE QUIETER WEATHER WITH ABOVE NORMAL TEMPERATURES AS SPLIT
UPPER LEVEL FLOW TAKES SHAPE AGAIN OVER THE COUNTRY DURING MID AND
LATE WEEK.
SHORT TERM...TODAY THROUGH TUESDAY NIGHT
LOW STRATUS CLOUDS AROUND 500 FT OR LESS HAVE DRIFTED NORTHWARD IN
SE LOW LEVEL FLOW OVER IL ALONG WITH SOME FOG ESPECIALLY FROM I-70
NORTH WHERE VISIBILITIES 1-3 MILES. TEMPERATURES SLOWLY INCREASING
IN THE 20S EARLY THIS MORNING WITH COOLEST READINGS OVER THE 1-2
INCH SNOW COVER FROM I-74 NORTH. 1033 MB HIGH PRESSURE WAS OVER
NEW ENGLAND WHILE STRONG 986 MB LOW PRESSURE WAS OVER THE EASTERN
CO/WY BORDER.
LATEST SHORT RANGE MODELS HAVE BACKED OFF ON QPF THIS AFTERNOON AS
MODELS INDICATE LIFT IN WARM AIR ADVECTION PATTERN WILL BE RATHER
DISORGANIZED. PLUS MOST OF THE SATURATED CONDITIONS ARE IN THE
LOWER LEVELS. SO ONLY EXPECTING ISOLATED LIGHT RAIN SHOWERS OR
SPRINKLES/DRIZZLE TO DEVELOP DURING TODAY. TEMPS INTO MID MORNING
STILL BELOW FREEZING WITH PATCHY FREEZING DRIZZLE POSSIBLE NORTH
OF I-70. GUIDANCE HAS TRENDED COOLER ON DAYTIME HIGHS TODAY
REACHED AT 00Z/6 PM IN THE LOWER 40S FROM I-74 NORTH AND AROUND 50F
IN SE IL. TEMPS WILL LIKELY CLIMB AHEAD OF APPROACHING STRONG COLD
FRONT FROM THE WEST THIS EVENING INTO THE UPPER 40S AND LOWER 50S.
CONTINUE HIGH CHANCES OF SHOWERS THIS EVENING WITH THUNDERSTORMS
POSSIBLE EAST OF THE IL RIVER WITH STRONG SURFACE LOW MOVING NE
INTO SE IA BY MIDNIGHT TONIGHT AND DEEPENING INTO SE WI BY DAWN
TUE. SHOWERS DIMINISH QUICKLY BEHIND THE COLD FRONT AND LINGERING
NEAR THE INDIANA BORDER EARLY OVERNIGHT. THEN WRAP AROUND LIGHT
RAIN CHANGING TO LIGHT SNOW MOVES INTO THE IL RIVER VALLEY LATER
TONIGHT AND CONTINUE SMALL CHANCE OF LIGHT SNOW AND FLURRIES OVER
NE COUNTIES MON MORNING MAINLY FROM I-74 NE.
SPC CONTINUES A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING
SE OF I-70 WITH YET ANOTHER COOL SEASON SEVERE WX THREAT IMPACTING
THIS PART OF IL LIKE LAST MONDAY NIGHT. A MODERATE RISK FURTHER
SOUTH OVER WEST TN...EASTERN AR AND NORTHERN MS. PER SPC DAY 1
OUTLOOK FOR THIS EVENING...A POWERFUL UPPER LEVEL TROUGH OVER THE
ROCKIES WILL MOVE EAST INTO THE MS VALLEY THIS EVENING. THE TROUGH
WILL BECOME NEGATIVELY- TILTED AS AN UPPER LEVEL LOW CLOSES OFF
OVER THE UPPER MIDWEST. AHEAD OF THE SYSTEM...A 50 TO 70 KT LOW
LEVEL JET WILL EXPAND NORTHWARD ACROSS THE MID MS VALLEY TODAY
WITH STRONG MOISTURE ADVECTION TAKING PLACE IN THE LOWER MS
VALLEY. A POWERFUL UPPER LEVEL TROUGH WILL MOVE ACROSS THE OZARK
PLATEAU EARLY THIS EVENING AS NUMEROUS THUNDERSTORMS INITIATE IN
THE MID MS VALLEY. VERY STRONG LARGE SCALE ASCENT ASSOCIATED WITH
THE UPPER LEVEL TROUGH AND UNIDIRECTIONAL WIND PROFILES EVIDENT ON
FORECAST SOUNDINGS SHOULD RESULT IN RAPID LINEAR DEVELOPMENT THIS
EVENING FROM EASTERN/SE IL SOUTHWARD INTO WESTERN KY. A WIND
DAMAGE THREAT SHOULD DEVELOP AS THE LINE SURGES QUICKLY EWD ACROSS
THE OH VALLEY DURING THE MID TO LATE EVENING. FORECAST SOUNDINGS
ACROSS MUCH OF THE OH VALLEY DURING THE 03Z TO 06Z TIMEFRAME
SUGGEST THAT A COOL SURFACE INVERSION WILL EXIST IN SPITE OF
STRONG MOISTURE ADVECTION. FOR THIS REASON...THE TORNADO THREAT IS
EXPECTED TO REMAIN MARGINAL EXCEPT IN SOUTHERN KY WHERE SFC
DEWPOINTS COULD APPROACH 60F.
INCREASED THE WINDS MONDAY WITH VERY TIGHT PRESSURE GRADIENT OVER
CENTRAL IL FROM DEEPENING LOW PRESSURE DEPARTING TO THE NE. TEMPS
WILL LIKELY SLIP DURING MONDAY MORNING WITH NOT MUCH RECOVERY
MONDAY AFTERNOON. CLOUDS DECREASE OVER SW AREAS MONDAY AFTERNOON
AND REST OF AREA MONDAY EVENING. WEAK HIGH PRESSURE OF 1023 MB
MOVES INTO KY/TN BY DAWN TUE AND RIDGES OVER IL DURING TUE. THIS
TO BRING FAIR WX MONDAY NIGHT AND TUE AS WINDS DIMINISH AND CLOUDS
DECREASE.
LONG TERM...WEDNESDAY THROUGH SATURDAY
00Z ECMWF MODEL HAS TRENDED FURTHER NORTH WITH QPF INTO CENTRAL
AND SE IL WED AFTERNOON THROUGH THU WHILE 00Z GFS SHOWS QPF OVER
JUST SE IL WED NIGHT WHICH CURRENT FORECAST AND ALLBLEND REFLECTS.
00Z GEM MODELS MAINLY KEEPS CENTRAL AND SE IL DRY DURING THIS TIME.
SPLIT UPPER LEVEL FLOW STILL PROJECTED DURING MID AND LATE WEEK
WITH STRONGER SOUTHERN STREAM SYSTEM/CUTOFF LOW TO STAY SOUTH OF
IL AND GETS ITS QPF CLOSEST TO SE IL WED NIGHT. DID NOT FOLLOW
ECMWF MODEL SINCE IT WAS A SHIFT FROM ITS PREVIOUS RUNS AND NOT IN
GOOD AGREEMENT WITH OTHER EXTENDED MODELS. WEAKER NORTHERN STREAM
TO KEEPS ITS LIGHT SNOW CHANCES NORTH OF CENTRAL IL OVER THE GREAT
LAKES. TEMPS OVERALL STILL APPEAR TO AVERAGE ABOVE NORMAL DURING
THIS TIME PERIOD.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
417 PM EST SUN JAN 22 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA TONIGHT AND
MONDAY...BRINGING POTENTIALLY SEVERE THUNDERSTORMS...STRONG
WINDS...AND HEAVY RAIN. MUCH COLDER AIR WILL FLOW IN BEHIND THE
FRONT. DRY WEATHER WILL THEN CONTINUE UNTIL MID TO LATE WEEK WHEN A
COUPLE OF SYSTEMS COULD BRING SOME LIGHT PRECIPITATION.
&&
.NEAR TERM /TONIGHT/...
LOTS OF ISSUES TO DEAL WITH IN THE NEAR TERM. MOST POTENT WILL BE
THE POTENTIAL FOR SEVERE CONVECTIVE WEATHER OVERNIGHT AHEAD OF
STRONG COLD FRONT.
ALTHOUGH WARM AIR IS SLOW IN COMING...LOOKING UPSTREAM SOME OF IT
SHOULD STILL GET HERE IN TIME FOR THE FORCING AHEAD OF THE FRONT.
TEMPERATURES MAY NOT BE QUITE AS WARM AS MODEL SHOWS...ESPECIALLY
NORTH WHERE THE SNOW COVER IS. BEST INSTABILITY WILL BE ALOFT
ANYWAY. ALTHOUGH EVEN THAT INSTABILITY WILL BE RELATIVELY
WEAK...THE VERY STRONG WINDS ALOFT WILL CREATE STRONG SHEAR.
850MB WINDS WILL BE UP TO 6 STANDARD DEVIATIONS ABOVE AVERAGE. EVEN
925MB WINDS WILL BE OVER 50KT...WITH GFS SHOWING 60-70KT IN
SOUTHWEST INDIANA. THUS THE SHEAR PLUS THE STRONG LIFT SHOULD
OVERCOME THE LACK OF INSTABILITY FOR STRONG THUNDERSTORMS...ESPECIALLY
ACROSS THE SOUTHERN FORECAST AREA WHERE BEST SHEAR WILL BE.
THE STORMS WILL HAVE TO PUSH THROUGH A DECENT INVERSION TO GET THE
DAMAGING WINDS TO THE SURFACE. THIS WILL AGAIN WILL BE EASIEST
ACROSS THE SOUTHERN FORECAST AREA WHERE TEMPERATURES WILL BE WARMER.
KEEP IN MIND THIS INVERSION HAS THE POTENTIAL TO LIMIT THE SEVERE
WEATHER IF IT IS STRONG ENOUGH. HOWEVER EVEN IF THE WINDS THAT
MAKE IT TO THE SURFACE ARE NON SEVERE...THE WET GROUND MAY ALLOW
TREES TO FALL DOWN EASIER.
THUS WILL MENTION SEVERE STORMS IN THE FORECAST. CURRENT TIMING
LOOKS TO BE 05-10Z. PRIMARY THREAT WILL BE THE DAMAGING WINDS...BUT
WITH THE STRONG SHEAR CANNOT RULE OUT TORNADOES.
THE OTHER PROBLEM WILL BE FLOODING POTENTIAL. EVEN A HALF INCH OF
RAIN MAY CAUSE AREAL FLOODING...AND THIS LINE DEFINITELY HAS THE
POTENTIAL TO DROP A HALF INCH. WILL CONTINUE TO MENTION FLOODING
POTENTIAL IN HWO.
TEMPERATURE FORECAST WILL BE TRICKY...WITH THE SLOW MOVEMENT OF THE
WARM AIR NORTH THIS AFTERNOON. WILL USE RUC AS A PART OF THE FIRST
GUESS AS LOW TEMPERATURES SHOULD OCCUR AT 00Z. READINGS WILL RISE
OVERNIGHT AND PERHAPS BEGIN TO FALL LATE TONIGHT.
WARM AIR MOVING OVER THE SNOW COVER ACROSS THE NORTH COULD LEAD TO
PATCHY DENSE FOG TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
FOCUS IS ON WINDS ON MONDAY. MODELS ARE SIMILAR ENOUGH SO THAT A
BLEND CAN BE USED FOR THE MOST PART.
ACTUAL COLD FRONT WILL PASS ACROSS THE AREA EARLY ON MONDAY. STRONG
WINDS COULD STILL MIX DOWN WITH ANY SHOWERS THAT DEVELOP ALONG THIS
FRONT. ALSO...WITH STRONG PRESSURE RISES BEHIND THE FRONT...THERE
WILL BE GUSTY WINDS THROUGHOUT THE DAY. BUFKIT SHOWS GUSTS NEAR 45
MPH POSSIBLE...ESPECIALLY ACROSS THE NORTHERN FORECAST AREA.
THUS WILL ISSUE A WIND ADVISORY ON MONDAY FOR 12Z-22Z. FAR SOUTHERN
FORECAST AREA IS MORE BORDERLINE...BUT WOULD RATHER BE
PESSIMISTIC...ESPECIALLY WITH POTENTIAL GUSTS ALONG FRONT ITSELF.
THERE LOOKS TO BE ENOUGH FORCING ALONG THE FRONT AND EVEN BEHIND IT
FOR A CHANCE FOR SHOWERS MONDAY MORNING. DURING THE AFTERNOON
MOISTURE AND FORCING ARE LIMITED. BY AFTERNOON ALSO TEMPERATURES
WILL BE COLD ENOUGH FOR SOME SNOW AS WELL. THUS WILL GO WITH
SPRINKLES OR FLURRIES MONDAY AFTERNOON.
TEMPERATURES WILL FALL ON MONDAY WITH HIGHS AT 12Z JUST AHEAD OF THE
FRONT.
DRY WEATHER WILL THEN MOVE IN MONDAY NIGHT INTO TUESDAY NIGHT WITH
HIGH PRESSURE MOVING IN. A BLEND OF MOS LOOKS OK FOR TEMPERATURES.
A SOUTHERN SYSTEM WILL MOVE NORTH ON WEDNESDAY WITH RAIN TRYING TO
WORK INTO THE AREA. THE MOISTURE WILL HAVE TO DISPLACE DRIER AIR
ASSOCIATED WITH HIGH PRESSURE TO THE NORTH. FOR NOW WILL JUST PUT
SLIGHT CHANCES FOR RAIN ACROSS THE FAR SOUTH DURING THE AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE MAIN CONCERN IN THE EXTENDED WILL BE POPS WEDNESDAY NIGHT AND
THURSDAY AS WELL AS FRIDAY NIGHT AS SEPARATE SYSTEMS IMPACT CENTRAL
INDIANA.
ALTHOUGH THE MODELS HAVE SOME TIMING ISSUES AS WELL AS ISSUES ABOUT
HOW FAR NORTH THE PRECIPITATION SHIELD WILL MAKE IT WEDNESDAY NIGHT
AND THURSDAY. BASIC SCENARIO HAS MOIST AIR RETURNING NORTHWARD FROM
THE GULF OF MEXICO OVERTOP A SOUTHERN WARM FRONT AND BEING LIFTED BY
A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS. CENTRAL REGION
INITIALIZATION SEEMS TO HANDLE THINGS OK BRINGING CHANCE POPS TO ALL
OF CENTRAL INDIANA WEDNESDAY NIGHT AND THURSDAY SIDING MORE WITH THE
00Z AND 12Z ECMWF. WENT WITH A MIX WEDNESDAY NIGHT AND THURSDAY
MORNING AS TEMPERATURES LOOK TO BOTTOM OUT IN THE UPPER 20S AND
LOWER 30S. WILL ONLY GO WITH RAIN ON THURSDAY AFTERNOON WITH
TEMPERATURES IN THE 40S.
LOOKS LIKE ANOTHER CHANCE FOR A RAIN AND SNOW MIX FRIDAY NIGHT AS
ANOTHER COLD FRONT DROPS DOWN FROM THE NORTHWEST. OTHERWISE...HIGH
PRESSURE SHOULD KEEP IT DRY. JET STREAM FLOW OFF THE PACIFIC
SUGGESTS WARMER THAN NORMAL TEMPERATURES THROUGH FRIDAY BUT BECOMING
MORE NEAR NORMAL STARTING SATURDAY AS INTERIOR CANADIAN WAVE DROPS
DOWN ACROSS THE LOWER GREAT LAKES.
&&
.AVIATION /DISCUSSION FOR THE 222100Z TAF UPDATE/...
MAIN CHANGE TO THE TERMINALS AT THE UPDATE IS TO KEEP VLIFR
CONDITIONS IN LONGER BASED ON CURRENT OBS. DO NOT ANTICIPATE
IMPROVING CONDITIONS UNTIL THIS EVENING.
18Z DISCUSSION FOLLOWS.
POOR FLYING CONDITIONS WITH IFR OR WORSE THROUGH THIS EVENING.
ALSO...LOW LEVEL WIND SHEAR EXPECTED AS A 45 PLUS KNOT LOW LEVEL JET
POINTS INTO CENTRAL INDIANA AFTER 22Z UNDERNEATH A STRONG INVERSION
WITH SOUTHEAST SURFACE WINDS AROUND 15 KNOTS. THE INVERSION WILL
BREAK AS A STRONG TO SEVERE LINE OF THUNDERSTORMS IS EXPECTED TO
REACH THE WESTERN TAF SITES AFTER 04Z AND EASTERN SITES AFTER 06Z.
LEFT A FOUR HOUR WINDOW OF VCTS AND CB WITH SOME UNCERTAINTY IN THE
AMOUNT OF INSTABILITY...BUT ADDED 3SM SHRA. THE COLD FRONT SHOULD
REACH THE WESTERN SITES AROUND 08Z AND EASTERN SITES AROUND 10Z.
THERE COULD ALSO BE A FEW SHOWERS PRIOR TO THE MAIN LINE...SO KEPT
VCSH GOING AFTER 22Z. FINALLY...CONDITIONS SHOULD IMPROVE TO MVFR
WITH THE FRONTAL PASSAGE AND WINDS SHOULD PICK UP TO AROUND 25 KNOTS
WITH GUSTS TO 35 KNOTS AFTER 13Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 7 AM TO 5 PM EST MONDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...MK/RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
250 PM EST SUN JAN 22 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN
UPDATED BELOW
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA TONIGHT AND
MONDAY...BRINGING POTENTIALLY SEVERE THUNDERSTORMS...STRONG
WINDS...AND HEAVY RAIN. MUCH COLDER AIR WILL FLOW IN BEHIND THE
FRONT. DRY WEATHER WILL THEN CONTINUE UNTIL MID TO LATE WEEK WHEN A
COUPLE OF SYSTEMS COULD BRING SOME LIGHT PRECIPITATION.
&&
.NEAR TERM /TONIGHT/...
LOTS OF ISSUES TO DEAL WITH IN THE NEAR TERM. MOST POTENT WILL BE
THE POTENTIAL FOR SEVERE CONVECTIVE WEATHER OVERNIGHT AHEAD OF
STRONG COLD FRONT.
ALTHOUGH WARM AIR IS SLOW IN COMING...LOOKING UPSTREAM SOME OF IT
SHOULD STILL GET HERE IN TIME FOR THE FORCING AHEAD OF THE FRONT.
TEMPERATURES MAY NOT BE QUITE AS WARM AS MODEL SHOWS...ESPECIALLY
NORTH WHERE THE SNOW COVER IS. BEST INSTABILITY WILL BE ALOFT
ANYWAY. ALTHOUGH EVEN THAT INSTABILITY WILL BE RELATIVELY
WEAK...THE VERY STRONG WINDS ALOFT WILL CREATE STRONG SHEAR.
850MB WINDS WILL BE UP TO 6 STANDARD DEVIATIONS ABOVE AVERAGE. EVEN
925MB WINDS WILL BE OVER 50KT...WITH GFS SHOWING 60-70KT IN
SOUTHWEST INDIANA. THUS THE SHEAR PLUS THE STRONG LIFT SHOULD
OVERCOME THE LACK OF INSTABILITY FOR STRONG THUNDERSTORMS...ESPECIALLY
ACROSS THE SOUTHERN FORECAST AREA WHERE BEST SHEAR WILL BE.
THE STORMS WILL HAVE TO PUSH THROUGH A DECENT INVERSION TO GET THE
DAMAGING WINDS TO THE SURFACE. THIS WILL AGAIN WILL BE EASIEST
ACROSS THE SOUTHERN FORECAST AREA WHERE TEMPERATURES WILL BE WARMER.
KEEP IN MIND THIS INVERSION HAS THE POTENTIAL TO LIMIT THE SEVERE
WEATHER IF IT IS STRONG ENOUGH. HOWEVER EVEN IF THE WINDS THAT
MAKE IT TO THE SURFACE ARE NON SEVERE...THE WET GROUND MAY ALLOW
TREES TO FALL DOWN EASIER.
THUS WILL MENTION SEVERE STORMS IN THE FORECAST. CURRENT TIMING
LOOKS TO BE 05-10Z. PRIMARY THREAT WILL BE THE DAMAGING WINDS...BUT
WITH THE STRONG SHEAR CANNOT RULE OUT TORNADOES.
THE OTHER PROBLEM WILL BE FLOODING POTENTIAL. EVEN A HALF INCH OF
RAIN MAY CAUSE AREAL FLOODING...AND THIS LINE DEFINITELY HAS THE
POTENTIAL TO DROP A HALF INCH. WILL CONTINUE TO MENTION FLOODING
POTENTIAL IN HWO.
TEMPERATURE FORECAST WILL BE TRICKY...WITH THE SLOW MOVEMENT OF THE
WARM AIR NORTH THIS AFTERNOON. WILL USE RUC AS A PART OF THE FIRST
GUESS AS LOW TEMPERATURES SHOULD OCCUR AT 00Z. READINGS WILL RISE
OVERNIGHT AND PERHAPS BEGIN TO FALL LATE TONIGHT.
WARM AIR MOVING OVER THE SNOW COVER ACROSS THE NORTH COULD LEAD TO
PATCHY DENSE FOG TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
FOCUS IS ON WINDS ON MONDAY. MODELS ARE SIMILAR ENOUGH SO THAT A
BLEND CAN BE USED FOR THE MOST PART.
ACTUAL COLD FRONT WILL PASS ACROSS THE AREA EARLY ON MONDAY. STRONG
WINDS COULD STILL MIX DOWN WITH ANY SHOWERS THAT DEVELOP ALONG THIS
FRONT. ALSO...WITH STRONG PRESSURE RISES BEHIND THE FRONT...THERE
WILL BE GUSTY WINDS THROUGHOUT THE DAY. BUFKIT SHOWS GUSTS NEAR 45
MPH POSSIBLE...ESPECIALLY ACROSS THE NORTHERN FORECAST AREA.
THUS WILL ISSUE A WIND ADVISORY ON MONDAY FOR 12Z-22Z. FAR SOUTHERN
FORECAST AREA IS MORE BORDERLINE...BUT WOULD RATHER BE
PESSIMISTIC...ESPECIALLY WITH POTENTIAL GUSTS ALONG FRONT ITSELF.
THERE LOOKS TO BE ENOUGH FORCING ALONG THE FRONT AND EVEN BEHIND IT
FOR A CHANCE FOR SHOWERS MONDAY MORNING. DURING THE AFTERNOON
MOISTURE AND FORCING ARE LIMITED. BY AFTERNOON ALSO TEMPERATURES
WILL BE COLD ENOUGH FOR SOME SNOW AS WELL. THUS WILL GO WITH
SPRINKLES OR FLURRIES MONDAY AFTERNOON.
TEMPERATURES WILL FALL ON MONDAY WITH HIGHS AT 12Z JUST AHEAD OF THE
FRONT.
DRY WEATHER WILL THEN MOVE IN MONDAY NIGHT INTO TUESDAY NIGHT WITH
HIGH PRESSURE MOVING IN. A BLEND OF MOS LOOKS OK FOR TEMPERATURES.
A SOUTHERN SYSTEM WILL MOVE NORTH ON WEDNESDAY WITH RAIN TRYING TO
WORK INTO THE AREA. THE MOISTURE WILL HAVE TO DISPLACE DRIER AIR
ASSOCIATED WITH HIGH PRESSURE TO THE NORTH. FOR NOW WILL JUST PUT
SLIGHT CHANCES FOR RAIN ACROSS THE FAR SOUTH DURING THE AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE MAIN CONCERN IN THE EXTENDED WILL BE POPS WEDNESDAY NIGHT AND
THURSDAY AS WELL AS FRIDAY NIGHT AS SEPARATE SYSTEMS IMPACT CENTRAL
INDIANA.
ALTHOUGH THE MODELS HAVE SOME TIMING ISSUES AS WELL AS ISSUES ABOUT
HOW FAR NORTH THE PRECIPITATION SHIELD WILL MAKE IT WEDNESDAY NIGHT
AND THURSDAY. BASIC SCENARIO HAS MOIST AIR RETURNING NORTHWARD FROM
THE GULF OF MEXICO OVERTOP A SOUTHERN WARM FRONT AND BEING LIFTED BY
A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS. CENTRAL REGION
INITIALIZATION SEEMS TO HANDLE THINGS OK BRINGING CHANCE POPS TO ALL
OF CENTRAL INDIANA WEDNESDAY NIGHT AND THURSDAY SIDING MORE WITH THE
00Z AND 12Z ECMWF. WENT WITH A MIX WEDNESDAY NIGHT AND THURSDAY
MORNING AS TEMPERATURES LOOK TO BOTTOM OUT IN THE UPPER 20S AND
LOWER 30S. WILL ONLY GO WITH RAIN ON THURSDAY AFTERNOON WITH
TEMPERATURES IN THE 40S.
LOOKS LIKE ANOTHER CHANCE FOR A RAIN AND SNOW MIX FRIDAY NIGHT AS
ANOTHER COLD FRONT DROPS DOWN FROM THE NORTHWEST. OTHERWISE...HIGH
PRESSURE SHOULD KEEP IT DRY. JET STREAM FLOW OFF THE PACIFIC
SUGGESTS WARMER THAN NORMAL TEMPERATURES THROUGH FRIDAY BUT BECOMING
MORE NEAR NORMAL STARTING SATURDAY AS INTERIOR CANADIAN WAVE DROPS
DOWN ACROSS THE LOWER GREAT LAKES.
&&
.AVIATION /DISCUSSION FOR THE 221800Z TAFS/...
POOR FLYING CONDITIONS WITH IFR OR WORSE THROUGH THIS EVENING.
ALSO...LOW LEVEL WIND SHEAR EXPECTED AS A 45 PLUS KNOT LOW LEVEL JET
POINTS INTO CENTRAL INDIANA AFTER 22Z UNDERNEATH A STRONG INVERSION
WITH SOUTHEAST SURFACE WINDS AROUND 15 KNOTS. THE INVERSION WILL
BREAK AS A STRONG TO SEVERE LINE OF THUNDERSTORMS IS EXPECTED TO
REACH THE WESTERN TAF SITES AFTER 04Z AND EASTERN SITES AFTER 06Z.
LEFT A FOUR HOUR WINDOW OF VCTS AND CB WITH SOME UNCERTAINTY IN THE
AMOUNT OF INSTABILITY...BUT ADDED 3SM SHRA. THE COLD FRONT SHOULD
REACH THE WESTERN SITES AROUND 08Z AND EASTERN SITES AROUND 10Z.
THERE COULD ALSO BE A FEW SHOWERS PRIOR TO THE MAIN LINE...SO KEPT
VCSH GOING AFTER 22Z. FINALLY...CONDTIONS SHOULD IMPROVE TO MVFR
WITH THE FRONTAL PASSAGE AND WINDS SHOULD PICK UP TO AROUND 25 KNOTS
WITH GUSTS TO 35 KNOTS AFTER 13Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 7 AM TO 5 PM EST MONDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...MK
AREA FORECAST DISCUSSION
NWS WICHITA KS
1147 AM CST SUN JAN 22 2012
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
STRONG LOW PRESSURE AND COLD FRONT WILL MOVE EAST ACROSS THE AREA
THIS EVENING. GUSTY SOUTH WINDS AHEAD OF THE FRONT WILL BECOME
STRONG AND GUSTY FROM THE NORTHWEST BEHIND THE FRONT. POST-FRONTAL
SHOWERS OF RAIN AND POSSIBLE SOME MIXED PRECIP/SNOW IS EXPECTED
LATE THIS AFTERNOON THROUGH THE EVENING...THOUGH CONDITIONS ARE
EXPECTED TO REMAIN PRIMARILY VFR WITH BRIEF PERIODS OF MVFR
POSSIBLE. WINDS WILL DIMINISH LATER TONIGHT INTO MONDAY MORNING.
KED
&&
.PREV DISCUSSION... /ISSUED 548 AM CST SUN JAN 22 2012/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
STRONG MOISTURE ADVECTION HAS RESULTED IN WIDESPREAD IFR CIGS
EARLY THIS MORNING OVER EASTERN KS. AT KCNU THEY SHOULD GRADUALLY
LIFT TO MVFR BY LATE MORNING. THINKING IFR CIGS WILL FLIRT WITH
KICT-KSLN-KHUT THROUGH LATE MORNING...BUT BRUNT OF THESE CIGS
SHOULD REMAIN EAST OF I-135 CORRIDOR. STRONG SOUTHWESTERLY LOW-
LEVEL JET OF 45-55 KTS IS AFFECTING THE AREA THIS MORNING...BUT
LLWS IS MARGINAL AT ALL TAF SITES DUE TO STRONG GROUND-LEVEL
WINDS. OTHERWISE...A STRONG COLD FRONT WILL BLAST SOUTHEAST ACROSS
THE AREA THIS AFTERNOON/EVENING. STRONG NORTHWEST WINDS ARE
ANTICIPATED BEHIND THE FRONT...ALONG WITH WIDESPREAD MVFR TO LOW
VFR CIGS AND SCATTERED RAIN SHOWERS. CIGS/SHOWERS SHOULD EXIT TO
THE EAST BY MID TO LATE EVENING...WITH WINDS SLACKENING SOME.
KLEINSASSER
PREV DISCUSSION... /ISSUED 314 AM CST SUN JAN 22 2012/
DISCUSSION...
TODAY-TONIGHT:
INITIAL ISSUE IS EVOLUTION OF LOW CLOUDS...WITH RUC STRUGGLING TO
STAY IN THE BALLPARK AND OTHERS EVEN WORSE. GIVEN TRENDS...SHOULD
SEE SLOW IMPROVEMENT THROUGHOUT THE MORNING ON WESTERN EDGE...BUT
SOUTHEAST KS WILL BE VERY SLOW TO CLEAR. SOME PATCHY DRIZZLE IS
POSSIBLE IN SOUTHEAST KS...FORTUNATELY TEMPERATURES WILL BE ABOVE
FREEZING. ALL MODELS SHOW SIGNIFICANT DRY SLOT WORKING ACROSS
SOUTHERN SECTIONS DURING THE AFTERNOON AHEAD OF COLD AIR
ADVECTION. MEANWHILE SURFACE PRESSURE GRADIENT AND LAPSE RATES
SHOULD SPREAD LOW END WIND ADVISORY CRITERIA OVER THE AREA WEST OF
A SLN-HARPER LINE FOR A FEW HOURS THIS AFTERNOON. WITH ARRIVAL OF
850MB MOISTURE...SHOULD SEE SPRINKLES/LIGHT RAIN DEVELOP THIS
AFTERNOON IN CENTRAL KS...AND SPREAD INTO THE FLINT HILLS FOR A
FEW HOURS THIS EVENING. LOOKS LIKE TEMPERATURES WILL BE WARM
ENOUGH THIS AFTERNOON/EVENING FOR PRECIPITATION TO REMAIN LIQUID.
DOWNGLIDE SHOULD QUICKLY SHUT DOWN PRECIPITATION IN THE EVENING.
WINDS WILL LIKELY REMAIN BRISK FOR MUCH OF THE NIGHT. A TOUGH CALL
ON LOWS GIVEN THE OPPOSITE IMPACTS OF WINDS AND COLD AIR ADVECTION.
MON-MON NIGHT:
RELATIVELY QUIET WEATHER ANTICIPATED WITH TEMPERATURES STILL
REMAINING AT OR ABOVE NORMAL.
TUE-TUE NIGHT:
PLAN TO STAY THE COURSE ON PRECIPITATION THIS PERIOD. MODELS
STILL STRUGGLING TO CONVERGE AS TO HOW FAR NORTH LOW LEVEL
MOISTURE WILL GO. HOWEVER BOTH GFS/ECMWF HAVE BEEN CONSISTENT THAT
EXTENSIVE HIGH CLOUDS WILL COVER THE AREA DURING THE DAY ON TUE.
USUALLY AM NOT AS CONFIDENT IN HIGH LEVEL MOISTURE MODEL
FORECASTS BEYOND DAYS 1-2...BUT THIS SEEMS REASONABLE GIVEN THE
DIFFLUENT UPPER FLOW NE OF UPPER LOW. GIVEN THE COOL START...LIGHT
SOUTHEAST WINDS AND EXTENSIVE CLOUDS...TEMPERATURES SHOULD STRUGGLE.
WED-SUN:
00 UTC RUN OF THE ECMWF HAS BROKE CONTINUITY...WITH NEW RUN
RESEMBLING THE 20/12 UTC RUN. THIS IS A FASTER/DEEPER SOLN. GFS
MEANWHILE HAS BEEN STRUGGLING AS WELL...ALTHOUGH FORECAST AREA
REMAINS IN BETWEEN THE US-CANADIAN BORDER SURFACE LOW AND
INCONSISTENT WEAK UPPER LOW IN THE SOUTHERN PLAINS. NET RESULT AT
LEAST FOR NOW IS DRY AND ABOVE NORMAL TEMPERATURES. OTHERWISE WILL
NEED TO WAIT FOR MORE CONSISTENCY BEFORE MAKING ANY SUBSTANTIAL
CHANGES. -HOWERTON
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
STRATUS CLOUDS HAVE ARRIVED AHEAD OF SCHEDULE MAINLY EAST OF THE
KANSAS TURNPIKE LATE THIS EVENING. AREAS MOST LIKELY TO BE IMPACTED
BY MVFR CIGS THROUGH THE MORNING HOURS ON SUNDAY WILL BE KICT AND
KCNU. IFR/LIFR WILL BE POSSIBLE THROUGH THE EARLY MORNING HOURS AT
KCNU WITH AREAS OF DRIZZLE WITHIN AN AREA OF LOW LEVEL
WAA/MOISTURE ADVECTION. INCREASING LARGE-SCALE FORCING FOR
SUBSIDENCE AND LOW LEVEL DRY AIR WILL SWEEP ACROSS THE AREA IN THE
WAKE OF A PRE-FRONTAL TROUGH DURING THE EARLY AFTERNOON HOURS WITH
A RETURN TO VFR ACROSS THE AREA. IN ADDITION...STRONG
WEST/NORTHWEST WINDS AROUND 25-35 KNOTS WILL BE POSSIBLE ACROSS
PORTIONS OF CENTRAL AND SOUTH CENTRAL KANSAS THROUGH THE AFTERNOON
HOURS.
MWM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 56 25 51 27 / 30 20 0 0
HUTCHINSON 50 26 49 27 / 40 30 0 0
NEWTON 53 27 48 27 / 40 30 0 0
ELDORADO 56 27 50 27 / 30 30 0 0
WINFIELD-KWLD 60 27 56 29 / 30 20 0 0
RUSSELL 47 22 50 22 / 50 30 0 0
GREAT BEND 47 22 50 22 / 50 20 0 0
SALINA 50 26 51 23 / 50 50 0 0
MCPHERSON 50 26 50 25 / 50 40 0 0
COFFEYVILLE 62 31 53 29 / 10 20 0 0
CHANUTE 58 29 50 26 / 10 20 0 0
IOLA 58 30 49 27 / 10 30 0 0
PARSONS-KPPF 60 27 52 26 / 10 20 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ032-033-047>051-
067-082-091.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1018 AM MST SUN JAN 22 2012
.UPDATE...
803 AM MST SUN JAN 22 2012
UPDATED GRIDS AND ZONES TO ADJUST PRECIPITATION TYPES. FORECAST
SOUNDINGS FOR THE FA INDICATE ALL RAIN FOR MOST OF THE MORNING AND
THEN A POSSIBLE MIX WITH SNOW AROUND NOON. SINCE THIS IS A FAST
MOVING SYSTEM EXITING THE FA BY EARLY AFTERNOON DO NOT EXPECT ANY
ACCUMULATION OTHER THAN SOME MINOR LOCALIZED AMOUNTS IN EXTREME
SOUTHWEST NEBRASKA ZONES. OTHERWISE NO OTHER CHANGES TO THE
CURRENT FORECAST.
FS
&&
.DISCUSSION...
339 AM MST SUN JAN 22 2012
MAIN FORECAST PROBLEM WILL BE TODAY. SATELLITE CONTINUING TO SHOW A
PROGRESSIVE AND ACTIVE WAVE TRAIN FROM THE PACIFIC INTO THE WESTERN
ATLANTIC. VERY STRONG SHORTWAVE APPROACHING FROM THE WEST THIS
MORNING WILL CAUSE A RATHER ACTIVE WEATHER DAY ACROSS THE REGION.
NEXT SYSTEM TO AFFECT THE AREA IS APPROACHING THE WEST COAST.
AT JET LEVEL THE NAM AND ECWMF WERE HANDLING THE STRONG SOUTHERN JET
APPROACHING OUR AREA AT THIS TIME. THIS WAS ESPECIALLY TRUE WITH
THE SEGMENT OVER THE OCEAN. AT MID LEVELS THE MODELS WERE HAVING A
LITTLE TROUBLE WITH THE INCOMING SYSTEM. THIS SYSTEM IS VERY STRONG
NOW AND IS LOOKING LIKE IT IS STILL STRENGTHENING. IMPRESSIVE AND
WIDESPREAD HEIGHT FALLS OF A LEAST 100 METERS TO ALMOST 200 METER
IN THE 700 TO 500 MB LAYER. THE NAM...CANADIAN AND ECMWF WERE DOING
THE BEST WITH THE SYSTEM AND WERE THE DEEPEST/SLOWEST.
TODAY/TONIGHT...00Z MODEL DATA CAME IN AND WAS STRONGER...SLOWER...
AND COLDER WITH INCOMING SYSTEM. PV ANALYSIS SHOWS THE 1.5 VALUE
DOWN AS LOW AS NEAR 500 MB. SIGNIFICANT SUBSIDENCE IS OCCURRING ON
THE BACKSIDE OF THE SYSTEM. LIGHTNING ALSO HAS OCCURRED WITH THE
SYSTEM. NO MATTER WHICH MODEL ONE CHOOSES...THEY ALL PRODUCE HIGH
WIND WARNING CRITERIA WINDS ACROSS THE ENTIRE AREA WITH THE GFS THE
STRONGEST. THE WESTERN PORTION OF THE AREA WILL HAVE THE HIGH
SPEEDS AND GUSTS DUE TO VERY HIGH LAPSE RATES...STRONGEST DOWNWARD
MOTION...AND HIGHEST THREE HOUR PRESSURE RISES. ALREADY HAVE ISSUED
AN UPDATE TO HAVE A HIGH WIND WARNING FOR THE ENTIRE AREA FROM 13Z
TO 01Z. COMPARISONS BETWEEN DIFFERENT STORMS IS NEVER PERFECT.
HOWEVER...THIS SETUP IS SIMILAR TO HIGH WIND EVENT THAT AREA
EXPERIENCED ON DECEMBER 31.
WHAT MAKES THIS SITUATION EVEN MORE INTERESTING IS THE PRECIPITATION
FORECAST. WIDESPREAD LIGHT PRECIPITATION LOOKS LIKE IT WILL OCCUR
OVER THE ENTIRE AREA. MODELS ARE NOW COLDER AND SHOWING SNOW WILL
BE POSSIBLE...ESPECIALLY ALONG AND NORTH OF THE INTERSTATE. THIS
WILL CREATE BLOWING SNOW PROBLEMS. CHOSE TO HANDLE THIS SITUATION
WITH ENHANCED WARNING FOR THE SNOW IN THE NPW. DAY SHIFT WILL NEED
TO TAKE A CLOSE LOOK AT THIS. WILL WATCH THE TEMPERATURES FOR AS
LONG AS POSSIBLE TONIGHT AND MAKE FINAL ADJUSTMENTS ON THE MAXES...
WHICH LOOK TO BE EARLY IN THE DAY. LATEST CANADIAN AND ESPECIALLY
THE HRRR CAPTURING REALITY WELL AND ADJUSTED ACCORDINGLY. THIS ALSO
MAY CAUSE ADJUSTMENTS TO THE PRECIPITATION PHASE. LATEST OBSERVATIONS
AND MODEL DATA SUPPORT THE WEATHER AND POP FORECAST PUT IN BY THE
EVENING SHIFT. NEWER DATA DOES SUPPORT A LITTLE MORE QPF THAN EARLIER
WAS THINKING. SO DID RAISE QPF AND SNOW AMOUNTS A LITTLE.
NEXT QUESTION IS WHAT TO DO WITH THE FIRE WEATHER WATCH. NEWER MODEL
GUIDANCE DOES NOT DROP DEWPOINTS AS MUCH AS BEFORE. PLUS
TEMPERATURES LOOK TO NOT BE AS WARM DUE TO THE SLOWER PROGRESSION
OF THE SYSTEM. ALSO EXPECT SOME LIGHT PRECIPITATION TO HAVE OCCURRED
AS WELL. AT PRESENT...THERE ONLY APPEARS TO BE AN EXTREMELY SMALL
WINDOW WHERE FIRE WEATHER CONCERNS CAN BE MET. ALSO BY THE
TIME THE DEWPOINTS COME DOWN...TEMPERATURES HAVE ALSO COOLED FROM
EARLY DAY MAXES. SO WILL CANCEL THE FIRE WEATHER WATCH.
WINDS LOOK TO DECOUPLE RATHER QUICKLY AND WILL HAVE LOW DEWPOINTS.
LOWERED MINS A LITTLE BUT STILL MAY NEED TO BE LOWERED.
MONDAY/MONDAY NIGHT...LIGHTER WINDS AND A DECENT AMOUNT OF SUN
BEHIND EXITING SYSTEM AND SURFACE RIDGE. THINKING IS THAT THERE WILL
BE MORE COLD AIR WITH THIS SYSTEM THAN CURRENTLY ADVERTISED PLUS
MAY BE SOME MINOR SNOW COVER ON THE GROUND. MODEL GUIDANCE NOT TOO
DIFFERENT BUT TRENDED TOWARD THE COOLER GUIDANCE. CLOUD COVER STARTS
INCREASING DURING THE NIGHT IN ADVANCE OF OUR NEXT SYSTEM.
TUESDAY/TUESDAY NIGHT...STRONG NORTH TO SOUTH JET EXISTS BEHIND
INCOMING SYSTEM. MAIN UPPER SYSTEM IS NOW FURTHER SOUTH THAN
YESTERDAY WITH MODELS IN GENERAL AGREEMENT ON ITS LOCATION OVER NEW
MEXICO. HOWEVER...THE CANADIAN IS FURTHER SOUTH THAN THAT WITH THE
SREF IN BETWEEN THE CANADIAN AND THE REMAINING GUIDANCE. MORE OPEN
BUT STILL MODERATE TO STRONG NORTHERN PORTION OF THIS SYSTEM MOVES
ACROSS AREA WITH SMALL SCALE 700 MB CIRCULATIONS IN FAVORABLE
LOCATIONS. MODELS BRING A GREAT DEAL OF MID LEVEL MOISTURE OVER THE
AREA DURING THE DAY WITH THE LOWER LEVELS BEING SLOWER TO MOISTEN
UP. HOWEVER...MODELS ARE SHOWING RATHER STRONG MESOSCALE AND
SYNOPTIC SCALE FORCING WITH FAVORABLE THETA-E LAPSE RATES IN PLACE.
MOST MODEL OUTPUT SHOWING VERY LIGHT QPF AND CONSIDERING ALL
PARAMETERS THAT MAKES SENSE. THINKING THE LIKELIHOOD OF MEASURABLE
IS LOW BUT THE PROBABILITY OF SOMETHING FALLING FROM THE SKY IS
RATHER HIGH. SO INSERTED SPRINKLES AND FLURRIES INTO THE FORECAST
FOR THE ENTIRE DAY AND INTO EARLY IN THE EVENING. DAY SHIFT WILL
HAVE TO TAKE ANOTHER CLOSE LOOK AT THIS DAY. CONSIDERING THE
THICKENING CLOUD COVER...UNFAVORABLE WIND DIRECTION...AND SOME COLD
AIR ADVECTION...TEMPERATURES SHOULD NOT DO MUCH THROUGH THE DAY.
THE NAM WAS MUCH COLDER THAN THE REST BUT AM NOT READY TO GO THERE
YET. DID LOWER MAXES SOME TO START TRENDING IN THAT DIRECTION.
BULLER
WEDNESDAY THROUGH SATURDAY...SHORTWAVE RIDGE EXPECTED TO BUILD OVER
CWA AS TROUGH SHIFT EAST. RESULT WILL BE DRY CONDITIONS AND WARMING
TREND THROUGH THURSDAY. ABOVE NORMAL TEMPS EXPECTED BOTH WED AND
THU...WITH MID/UPPER 50S ON THURSDAY. SHORTWAVE TROUGH PUSHES ACROSS
NORTHERN PLAINS FRI/SAT WITH ASSOCIATED COLD FRONT PUSHING SOUTH
OVER CWA. SIGNIFICANT DIFFERENCES IN DETERMINISTIC GUIDANCE ON
TIMING OF THESE FEATURES...WITH ECMWF CURRENTLY FASTER AND WETTER.
CONSIDERING POSITION OF SHORTWAVE AND LITTLE IN THE WAY OF ENSEMBLE
SUPPORT FOR ECMWF SOLUTION...IVE KEPT FORECAST DRY. I ALSO KEPT
TEMPS CLOSER TO CLIMATE NORMALS SHOWING A TEMPERED COOING TREND
FRI/SAT RATHER THAN THE COLDER ECMWF SOLUTION. IN ANY
CASE...CONFIDENCE BELOW NORMAL FOR DAYS 6/7.
DR
THANKS TO ALL THAT COLLABORATED.
&&
.AVIATION...
1018 AM MST SUN JAN 22 2012
FOR THE 18Z TAFS...STRONG NORTHWESTERLY WINDS WILL CONTINUE THIS
AFTERNOON...TAPERING OFF DURING THE EVENING. THERE IS ALSO THE
POTENTIAL FOR MIXED PRECIPITATION WITH THE TROUGH MOVING OVER THE
AREA. CURRENT OBS SHOW DRIZZLE AND LIGHT SNOW UPSTREAM OF
KGLD...AND DRIZZLE UPSTREAM OF KMCK. BASED ON THESE OBS AND THE
LATEST HRRR...HAVE INCLUDED VCSH AT KGLD WITH A TEMPO GROUP EARLY
IN THE AFTERNOON FOR LIGHT RAIN/SNOW...AND BROUGHT VCSH IN LATER
THIS AFTERNOON AT KMCK. MVFR CEILINGS SHOULD CONTINUE THROUGH THE
AFTERNOON AT KGLD...AND MVFR CEILINGS SHOULD MAKE IT TO KMCK EARLY
IN THE PERIOD.
CJS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
KSZ001>004-013>016-027>029-041-042.
NE...HIGH WIND WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
NEZ079>081.
CO...HIGH WIND WARNING UNTIL 6 PM MST THIS EVENING FOR COZ090>092.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1117 AM CST SUN JAN 22 2012
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
EXPECT VFR CONDITIONS THROUGH MUCH OF THIS TAF PERIOD. A STRONG
UPPER LEVEL SHORTWAVE TROUGH AXIS WILL MOVE OVER THE TAF SITES
AROUND NOON WITH MID LEVEL CIGS LOWERING TO AROUND 4KFT WITH SOME
LIGHT RAIN SHOWERS BY 20-22Z WITH SOME AREAS OF MVFR CIGS. ALSO
EXPECT NORTHWEST WINDS TO INCREASE TO 30KT WITH GUSTS TO 45KTS
AROUND THE SAME TIME PERIOD AND LAST THROUGH 23-01Z. AFTER THAT
TIME FRAME AS THE UPPER LEVEL WAVE CONTINUES TO MOVE EAST LOOK FOR
CLEARING SKIES AND NORTHWEST WINDS DECREASING TO 20KTS BY SUNSET
AND BECOMING WEST AROUND 10KT AFTER 09Z.
&&
.PREV DISCUSSION... /ISSUED 709 AM CST SUN JAN 22 2012/
UPDATE...
LIGHT PRECIPITATION BEGINNING TO SPREAD INTO NORTHWEST KANSAS
BASED ON MOSAIC RADAR. BASED ON THE RUC THE HIGHER RETURNS
APPEARS TO BE ASSOCIATED WITH AN AREA OF 850-700MB FRONTOGENESIS
UNDER THE 500MB DEFORMATION ZONE. THIS BAND OF FRONTOGENESIS IS
CURRENTLY FORECAST TO MOVE TO NEAR SYRACUSE AND SCOTT CITY BY 15Z
AND THEN CROSS THE REMAINDER OF SOUTHWEST KANSAS BETWEEN 15Z AND
21Z. HAVE THEREFORE ADJUSTED TIMING OF INCREASING CLOUDS AND
DEVELOPING PRECIPITATION. LEFT EXIT REGION OF A 250 JET CONTINUES
TO HIGHLIGHT NORTH CENTRAL KANSAS AS AN AREA OF BETTER LIFT
BETWEEN 18Z AND 21Z SO WILL ALSO INCREASE PRECIPITATION CHANCES IN
THIS REGION LATER THIS AFTERNOON. -RB
PREV DISCUSSION... /ISSUED 242 AM CST SUN JAN 22 2012/
DISCUSSION...
SHORT TERM /TODAY THROUGH MONDAY NIGHT/
THE REGIONAL AND SYNOPTIC SCALE FEATURES THIS MORNING INCLUDE A
RAPIDLY ADVANCING UPPER LEVEL TROUGH/PV ANOMALY FROM THE WESTERN
STATES THROUGH THE CENTRAL ROCKIES THIS MORNING. MEANWHILE, STEADY
SURFACE PRESSURE FALLS HAVE BECOME NEARLY NEUTRAL ON MSAS ACROSS THE
HIGH PLAINS FROM WYOMING THROUGH WESTERN KANSAS. SOUTHERLY, BETTER
THAN EXPECTED MIXED SURFACE WINDS ACROSS THE FAR WESTERN COUNTIES
HAVE HELPED MAINTAIN MILD TEMPERATURES OVERNIGHT IN THE LOW 50S AND
UPPER 40S. AS THE UPPER TROUGH APPROACHES, INCREASING PERIODICITY OF
MID LEVEL CLOUD BANDS ARE BEGINNING TO DEVELOP WHICH ARE BEING
OBSERVED IN THE REGIONAL 11-3.9 MICRON AND INFRARED SATELLITE
IMAGERY.
THE CURRENT MODELS RUNS HAVE COME TOGETHER WITH MUCH STRONGER 2
METER WIND SPEEDS THAN A FEW RUNS AGO, AND ALL OF THE MODELS SEEM TO
BE INCREASING MAGNITUDE WITH TIME. THERE IS NOT A SIGNIFICANTLY
DEEP UNSTABLE LAYER, BUT THE NAM DOES INDICATE VERY IMPRESSIVE LOW
LEVEL 0-1 KM LAPSE RATES LATE THIS MORNING AND THIS AFTERNOON NEAR
10 DEG C/KM IN AN ENVIRONMENT WITH 40 KNOT SUSTAINED WINDS JUST
OFF THE SURFACE. EVEN THE 40KM GFS IS INDICATING 25 TO 30 KNOT 2
METER WINDS TODAY. GFS MOS IS PRODUCING SUSTAINED WIND SPEEDS
ACROSS THE WESTERN COUNTIES AROUND 40+ KNOTS SUSTAINED LATE
MORNING AND EARLY AFTERNOON. AS A RESULT, WE HAVE INCREASED
CONFIDENCE IN HOISTING A HIGH WIND WARNING FOR ALL AREAS ALONG
WEST OF GENERALLY THE HIGHWAY 283 CORRIDOR. A RAPIDLY COOLING
BOUNDARY LAYER SHOULD BRING THE WIND SPEEDS DOWNS IN THE MID TO
LATE AFTERNOON, BUT CONDITIONS MAY REMAIN BREEZY THROUGH THE LATE
AFTERNOON AND EVEN THE EARLY EVENING IN THE EASTERN COUNTIES. A
DECENT LAYER OF 800-700 MB MOISTURE TRANSPORT DOES SHOW UP IN
MODEL FIELDS BEHIND THIS BOUNDARY AND MODEL SOUNDINGS SHOW AN
IMPRESSIVE SATURATED LAYER BEHIND THE PV ANOMALY IN THE COLD POOL
OF AIR. THERMAL FIELDS INDICATE SOME DENDRITIC PRODUCTION IS
POSSIBLE AND EVEN LIKELY, BUT LOW LEVEL TEMPERATURES MAY NOT
SUPPORT THAT AND RAIN SHOWERS ARE PROBABLY THE MORE LIKELY
PRECIPITATION TYPE WITH THIS WAVE.
POPS AND WINDS WILL DIMINISH RAPIDLY IN THE EVENING. THE EXTENT TO
HOW COLD IT GETS OVERNIGHT WILL DEPEND ON THE MAGNITUDE OF COLD
ADVECTION, BUT THE COLDER MOS SEEMS THE BEST CHOICE TONIGHT.
TEMPERATURES ARE NOT EXPECTED TO REBOUND SIGNIFICANTLY IN MONDAY
OTHER THAN USUAL DIURNAL HEATING AS WEAK SOUTHERLY RETURN FLOW OF
COLD ANTICYLONE AIR REMAINS. ANOTHER RELATIVELY COOL NIGHT WITH GOOD
RADIATIONAL COOLING IN THE LOW 20S IS ANTICIPATED MONDAY
NIGHT.
LONG TERM...
BY TUESDAY NIGHT OUR NEXT PACIFIC UPPER LEVEL STORM SYSTEM WILL BE
DIGGING INTO SOUTHEAST NEW MEXICO. THIS UPPER LEVEL TROUGH WAS ALSO
STARTING TO BECOME CUT OFF FROM THE MEAN FLOW AS WELL. THE NEW 00Z
MODELS NOT DIFFERING MUCH FROM THE PREVIOUS MODEL RUNS IN THIS UPPER
LOW DEVELOPING NEAR THE MEXICO/SOUTHWEST TEXAS BORDER BY EARLY
WEDNESDAY AND THEN SLOWLY DRIFTING EAST THROUGH LATE WEEK. AHEAD OF
THIS SYSTEM ABUNDANT MID TO UPPER LEVEL MOISTURE IS ANTICIPATED TO
SPREAD INTO WESTERN KANSAS. GIVEN THE MOISTURE EXPECTED AND
DIFLUENT FLOW DEVELOPING WITH THE 500MB DEFORMATION ZONE WILL
INCREASE CLOUD COVER AND AS A RESULT OF THIS LOWER TEMPERATURES
TUESDAY AFTERNOON.
ON TUESDAY NIGHT THE 500MB DEFORMATION ZONE WILL MOVE
SOUTH/SOUTHEAST OF THE AREA. BEHIND THIS DEFORMATION ZONE
ANTICYCLONIC FLOW DEVELOPS ACROSS WESTERN KANSAS WITH LIMITED
MOISTURE PRESENT. GIVEN THE CLEARING SKIES AND 900-850MB TEMPERATURE
TRENDS THE PREVIOUS TEMPERATURE FORECAST STILL LOOKS ON TRACK WITH
WARMER TEMPERATURES RETURNING TO WESTERN KANSAS. THIS WARMUP HOWEVER
WILL BE SHORT LIVED AS ANOTHER COLD FRONT IS FORECAST TO BEGIN TO
DROP SOUTH ACROSS THE NORTHERN PLAINS LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 22 50 23 / 40 0 0 0
GCK 50 20 49 22 / 30 0 0 0
EHA 52 23 50 25 / 20 0 0 0
LBL 52 20 50 23 / 20 0 0 0
HYS 48 20 49 20 / 60 0 0 0
P28 55 25 53 26 / 30 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 5 PM CST /4 PM MST/ THIS AFTERNOON FOR
KSZ030-043>045-061>064-074>078-084>088.
WIND ADVISORY UNTIL 7 PM CST THIS EVENING FOR KSZ031-046-065-066-
079>081-089-090.
&&
$$
FN06
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
316 PM CST SUN JAN 22 2012
.DISCUSSION...
/316 PM CST SUN JAN 22 2012/
MAIN CONCERN CONTINUES TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS
OVER THE AREA THIS EVENING. MOST RECENT SURFACE ANALYSIS IS SHOWING
AN OCCLUDING SURFACE LOW OVER KANSAS WITH A WARM FRONT EXTENDING
FROM CENTRAL OKLAHOMA INTO THE MID SOUTH. TEMPERATURES AND DEWPOINTS
HAVE BEEN SLOWLY RISING OVER THE CWA TODAY AND WILL CONTINUE TO DO
SO INTO EARLY THIS EVENING AS THETA-E ADVECTION INCREASES FROM THE
SOUTH IN RESPONSE TO CENTRAL PLAINS UPPER TROUGH. STILL APPEARS
THAT SHOWERS AND THUNDERSTORMS MAY DEVELOP OVER SOUTHEAST MISSOURI
INTO SOUTHERN ILLINOIS BETWEEN 22-02Z IN AREA OF STRONG 925-850MB
MOISTURE ADVECTION. MAIN CHANCE FOR SEVERE THUNDERSTORMS WILL LIKELY
OCCUR THIS EVENING WHEN VERY STRONG/DEEP ASCENT CAUSED BY THE NEGATIVELY
TILTING MID LEVEL TROUGH WILL COINCIDE WITH MODEST INSTABILITY AND
VERY STRONG DEEP LAYER SHEAR. HRRR RUNS HAVE BEEN CONSISTENT TODAY
AND REASONABLY DEPICT A LINE OF STORMS DEVELOPING QUICKLY AROUND
02Z OVER SOUTHEASTERN MISSOURI THAT MOVES NORTHEASTWARD INTO THE
FAR EASTERN CWA BY 04Z. RUC SOUNDINGS DEPICT THAT THE LOW LEVEL
INVERSION WILL WEAKEN DURING THIS PERIOD WHICH SHOULD ALLOW FOR A
DAMAGING WIND THREAT WITH THE LINE. THERE IS ALSO SOME TORNADO
THREAT WITHIN THE LINE GIVEN 0-1KM BULK SHEAR VALUES BETWEEN
0-1KM.
PRECIPITATION WILL QUICKLY MOVE OUT OF THE AREA AFTER 06Z AS THE TROUGH/
SURFACE FRONT MOVES EAST OF THE AREA. LEFT THE CHANCE OF FLURRIES OVER
NORTHERN MISSOURI INTO WEST CENTRAL ILLINOIS LATE TONIGHT INTO LATE
MORNING MONDAY ON THE SOUTH SIDE OF THE DEEPENING UPPER LOW. THEN
EXPECT DRY WEATHER UNTIL EARLY WEDNESDAY. 12Z GFS BROUGHT STRONGER
ASCENT ALONG WITH SOME QPF UP TO I-70 DURING THE DAY WEDNESDAY.
THE 12Z NAM SUPPRESSED WITH PRECIPITATION TO THE SOUTH...MOST LIKELY
BECAUSE IT IS BRINGING A NORTHERN STREAM SHORTWAVE ACROSS THE
GREAT LAKES TOO QUICKLY. THE 18Z VERSION OF THE NAM AND THE 12Z
ECMWF FAVOR THE NORTHERN PLACEMENT. PRECIPITATION ON THE NORTHERN
FRINGE OF THIS SYSTEM WILL BE LIGHT AS THERE WILL BE STEADY DRY
AIR ADVECTING INTO IT. THIS WILL ALSO LIKELY ALLOW THE RAIN TO MIX
WITH OR CHANGEOVER TO SNOW AT TIMES AS THE WET BULB REMAINS NEAR
OR BELOW ZERO.
BRITT/KANOFSKY
&&
.AVIATION...
/1136 AM CST SUN JAN 22 2012/
LOW STRATUS AND FOG WITH PATCHY DRIZZLE WILL PERSIST FOR THE NEXT
SEVERAL HOURS WITH DAYTIME MIXING CAUSING ONLY LIMITED
IMPROVEMENT HOWEVER SFC TEMPERATURES HAVE RISEN ABOVE ZERO
THEREFORE THE THREAT OF FREEZING DRIZZLE HAS ENDED. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE REGION LATE THIS
AFTERNOON AND TONIGHT AHEAD OF A STRONG COLD FRONT. ATTM IT LOOKS
LIKE THUNDERSTORMS WILL DEVELOP NEAR KUIN/KSUS/KCPS BETWEEN
00-04Z. WINDS TURN WLY BEHIND THE FRONT WITH GUSTS AROUND 30 KTS
EXPECTED TOMORROW MORNING AS STRONGER WINDS ALOFT MIX DOWN TO THE
SURFACE.
SPECIFICS FOR KSTL...LOW STRATUS AND FOG WITH PATCHY DRIZZLE WILL
PERSIST FOR THE NEXT SEVERAL HOURS. ATTM IT LOOKS LIKE
THUNDERSTORMS WILL DEVELOP NEAR KSTL BETWEEN 00-04Z. WINDS TURN
WLY BEHIND THE FRONT WITH GUSTS AROUND 30 KTS EXPECTED TOMORROW
AS STRONGER WINDS ALOFT MIX DOWN TO THE SURFACE.
KANOFSKY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
310 PM CST SUN JAN 22 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY.
MAIN FORECAST CHALLENGE AND CONCERN CENTERS AROUND SNOW AND
BLOWING SNOW OVERNIGHT.
STRONG MID/UPPER LEVEL TROF AXIS NOW EXTENDS ACROSS THE CENTRAL
PLAINS WITH A WEAKER SECONDARY SHORTWAVE AXIS EXTENDING ACROSS
ERN MT INTO ERN WY. AT THE SFC...LOW PRESSURE IS QUICKLY MOVING
EAST ACROSS CENTRAL KANSAS WITH AN INVERTED TROF/CDFNT EXTENDING
UP THE MISSOURI RIVER VALLEY AT 21Z. REGIONAL MOSIAC RADAR LOOP
SHOWS A WIDENING NARROW MID LEVEL FRONTOGENETICAL BAND OF LIGHT TO
MODERATE PCPN OCCURING JUST BEHIND THE BOUNDARY WITH
LIGHTER/WIDESPREAD SNOWFALL OCCURING IN BROADSCALE VERTICAL MOTION
ASSOCIATED DEFORMATION ZONE BEHIND THE FRONTOGENETIC BAND. THE DRY
SLOT OVER PORTIONS OF SOUTHEAST NEB AS EVIDENT ON SATELLITE
IMAGERY CONTINUES TO SLOWLY FILL IN THIS AFTERNOON. TEMPERATURES
AHEAD OF THE BOUNDARY HAVE JUMPED INTO THE MID TO UPPER 40S WITH
LOWER TO MID 50S IN EXTREME SOUTHEAST NEBRASKA. COLD POCKET AT
850MB IS DIRECTLY TO OUR NORTH ACROSS ERN SD PER UPPER AIR
ANALYSIS AND RUC GUIDANCE. THIS COLD POCKET WILL CONTINUE TO DRIFT
SOUTH INTO THE FORECAST AREA THROUGH EARLY EVENING...AIDING IN
QUICKLY DROPPING SFC TEMPS BELOW FREEZING BEHIND THE BOUNDARY.
PCPN WILL CONTINUE TO INCREASE FROM WEST TO EAST ACROSS THE CWA AS
THE MID/UPPER LEVEL TROF CONTINUES TO DRIFT EWD AND
BECOMES NEGATIVELY TILTED AS IT MOVES TOWARD THE MISSISSIPPI VALLEY.
FIRST PUSH IS ALREADY APPROACHING OUR FAR NWRN COUNTIES IN WELL
DEFINED MID LEVEL FRONTOGENETIC BAND EXTENDING FROM NERN NEB INTO
WRN KS. PCPN TYPE WITH THIS WILL BE TRICKY BUT AS WE LOOSE DAYLIGHT
AND ABOVE MENTIONED COLD PUSH FROM ERN SD ADVECTS DOWN...WE SHOULD
BEGIN TO TURN ANY LIQUID PCPN OVER TO SNOW RATHER QUICKLY AS WE
PROGRESS THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS. SECOND
PUSH OF LIGHT SNOW WILL COME WITH THE MORE BROADSCALE LIFT BEHIND
THE TROF IN DEFORMATION AREA. LINGERING PCPN WILL LIKELY OCCUR
AHEAD OF THE SECONDARY NRN HIGH PLAINS SHORTWAVE THROUGH THE EARLY
MONDAY MORNING HOURS.
QPF AMOUNTS ARE GENERALLY LESS THAN 0.20" IN THE NORTH AT
MOST...WITH LESS THAN 0.10" IN OUR SOUTH. GOING FORECAST HAS A
GOOD HANDLE ON SNOWFALL AMOUNTS AND CONTINUE TO THINK THAT A 1-2"
SWATH ACROSS THE NORTHERN COUNTIES WITH ABOUT 0.5" TOWARD THE I-80
CORRIDOR.
NORTHWEST WINDS WILL PICK UP BEHIND THE BOUNDARY AFTER SUNSET WITH
GUSTS NEAR 40 MPH LIKELY INTO THE OVERNIGHT. IN THE NORTH...THIS
WILL CREATE AREAS OF BLOWING SNOW AND SO GOING WINTER WEATHER
ADVISORY FOR SNOW AND BLOWING SNOW THRU 12Z STILL LOOKS GOOD. HAVE
EXPANDED THE ADVISORY SLIGHTLY SOUTH AND EAST. WITH NEAR OR LESS
THAN AN INCH OF SNOW TO THE SOUTH OF THE ADVISORY AREA...WILL HOLD
OFF ON ANY ADVISORY BUT ROADS MAY STILL BECOME SLICK WITH JUST
MINOR SNOWFALL ACCUMULATIONS.
THE SYSTEM MOVES EAST OF THE AREA ON MONDAY AND FORECAST AREA
LOOKS DRY AS WEAK UPPER RIDGING MOVES OVERHEAD. PATTERN EVOLVES
INTO A SPLIT FLOW REGIME BY TUESDAY NIGHT WITH SOUTHERN CLOSED
LOW MOVING ACROSS TEXAS AND A WEAK SHORTWAVE AXIS CROSSING THE
FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY. HAVE REMOVED POPS
TUESDAY NIGHT AS SOUTHERN STREAM SYSTEM APPEARS TO BE FAR REMOVED
FROM THE FORECAST AREA TO INDUCE ANY PCPN.
KERN
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY.
PATTERN IN THE EXTENDED PERIOD BEGINS MILD AND APPEARS IT
WILL BECOME MORE NORTHWESTERLY AND COOLER TOWARD NEXT
WEEKEND...ALTHOUGH SOME QUESTION ON WHETHER IT WILL BEGIN TO
MODERATE BY DAY 7. FORECAST GENERALLY LOOKS DRY...ALTHOUGH A SMALL
PRECIP CHANCE WILL BE CARRIED IN FRIDAY PERIOD NERN ZONES. VERY
GOOD AGREEMENT EXISTED BETWEEN 12Z GFS/CMC AND 12Z/00Z ECMWF WITH A
SHORTWAVE THROUGH DRIVING A COLD FRONT ACROSS FORECAST AREA
EARLY FRIDAY. EVEN 00Z GFS ENSEMBLE MEAN WAS IN ACCORDANCE. SEVERAL
DIFFERENCES EXISTED...HOWEVER...IN EXACTLY HOW WARM WILL THURSDAY
BE...WITH CANADIAN EXCEPTIONALLY MILD...CLOSE TO +10 DEG C AT H85.
MEANWHILE 00Z ECMWF HAD FLIPPED TO A LITTLE BELOW ZERO FROM WARMER
SOLUTION YESTERDAY AND THEN BACK TO A WARMER ONE THIS MORNING. GFS
APPEARED TO BE A DECENT COMPROMISE AND COULD YIELD READINGS PER
PREVIOUS FORECAST AND LITTLE CHANGES WERE MADE. MILD TEMPERATURES
ALOFT AHEAD OF FRONT FRIDAY COULD MIX DOWN JUST AHEAD OF OR WITH
FROPA. SO ALTHOUGH MAX TEMPS WILL PROBABLY BE COOLER THAN
THURSDAY...GENERALLY LEFT HIGHS MOSTLY ABOVE 12Z MEX NUMBERS.
COOLING TREND WAS CONTINUED INTO SATURDAY AND TO SOME DEGREE INTO
SUNDAY EVEN THOUGH LATEST GFS/ECMWF SUGGESTED MODERATION BY DAY 7.
WITH UPPER FLOW STARTING NEXT WEEKEND NORTHWESTERLY...DIDN/T WANT TO
BE OVERLY OPTIMISTIC JUST YET WAITING FOR A MODERATING WAVE TO SHIFT
FLOW TO MORE WESTERLY.
CHERMOK
&&
.AVIATION...18Z TAFS FOR KOMA...KLNK...KOFK.
LOOK FOR SOME SIGNIFICANT CHANGES OVER THE NEXT 6HRS AS A COLD
FRONT MOVES THROUGH. THE WIND SHIFT IS STARTING AT KOFK TO THE
NORTHWEST...SOUTHWEST AT KLNK AND STILL FROM THE SOUTHEAST AT
KOMA. GUSTY NORTHWEST WINDS WILL EVENTUALLY MAKE THEIR WAY TO ALL
OF THE TAF SITES THROUGH 01Z AND WILL REMAIN STRONG AT 15 TO 24KTS
SUSTAINED...WITH GUSTS 25 TO 32KTS THROUGH MONDAY MORNING.
VARIABLE CIGS ARE EXPECTED THROUGH EARLY EVENING AS MVFR CIGS
BREAK OUT TO VFR AT TIMES. EVENTUALLY MVFR/IFR CIGS AND VSBYS WILL
SETTLE IN. SOME OF THE PRECIPITATION MAY START AS RAIN...THEN
CHANGE OVER TO SNOW THIS EVENING AND OVERNIGHT. THE STRONG WINDS
COMBINED WITH THE SNOW SHOULD REDUCE VSBYS TO IFR AND LOCALLY
LIFR. THE BULK OF THE FALLING SNOW SHOULD BE EAST OF THE TAFS BY
12Z WITH MVFR CIGS FOR MUCH OF THE MORNING.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR NEZ011-012-
015>018-030>034-042-043.
IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR IAZ043.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1237 PM CST SUN JAN 22 2012
.UPDATE...
ADJUSTED TEMPS...WX...HAZARDS AND CLDS BASED ON CURRENT TRENDS.
&&
.DISCUSSION...
BY 18Z...TEMPS HAS WARMED TO FREEZING OR WARMER ACROSS THE CWA
WITH 40S FOR MUCH AREA AND 50 AT FNB. A LINE OF SHOWERS/LIGHT RAIN
HAD DEVELOPED WITH THE WIND SHIFT FROM LEXING TO ORD TO ONL...WITH
THE SNOW LAGGING BACK TOWARD VTN. THE ISENTROPIC LIFT ON THE 280
DEGREE SURFACE SATURATES PARTS OF NORTHEAST NEBRASKA FIRST AND
THEN INTO OUR WRN CWA. THE LATEST HRRR HAS THE BAND OF LIGHT
RAIN/SHOWERS PROGRESSING EAST...WITH THE RAIN/SNOW IN THE NORTH
THRU THE AFTERNOON.THE NAM/GFS ARE SIMILAR WITH DYNAMIC COOLING
CHANGING THE RAIN OVER TO SNOW IN THE WRN CWA. LEFT SOME LOW POPS
IN THE FAR EAST PART OF THE FORECAST AREA THIS AFTERNOON...WITH
DRY CONDITIONS WHERE THE CLDS HAVE CLEARED...THEN PICK UP THE
POPS AGAIN IN THE WEST WITH A GRADIENT OF HIGH POPS AND RAIN
CHANGING TO SNOW. THE NORTHWEST SHOULD SEE A LITTLE QUICKER
CHANGEOVER TO SNOW AND BLOWING SNOW AND COULD SEE SOME LIGHT INCH
OR LESS ACCUMULATIONS IN THE NORTHWEST BY EARLY EVENING. HEADLINES
WILL NEED TO BE LOOKED AT FURTHER FOR THE AFTERNOON PACKAGE...BUT
FOR NOW INCLUDED A FEW COUNTIES SOUTH AND EAST...AND EXTENDED THE
TIME TO 12Z. THE STRONG WINDS AND FALLING SNOW SHOULD CONTINUE
AFTER MIDNIGHT...THUS FELT IT PRUDENT TO CONTINUE THE ADVISORY
WITH THE BLOWING SNOW EXPECTED. THE WINDSHIFT HAS MADE IT TO BVN
AND WINDS ARE GUSTING 26-42KTS FROM AINSWORTH WESTWARD.
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK...KOFK.
LOOK FOR SOME SIGNIFICANT CHANGES OVER THE NEXT 6HRS AS A COLD
FRONT MOVES THROUGH. THE WIND SHIFT IS STARTING AT KOFK TO THE
NORTHWEST...SOUTHWEST AT KLNK AND STILL FROM THE SOUTHEAST AT
KOMA. GUSTY NORTHWEST WINDS WILL EVENTUALLY MAKE THEIR WAY TO ALL
OF THE TAF SITES THROUGH 01Z AND WILL REMAIN STRONG AT 15 TO 24KTS
SUSTAINED...WITH GUSTS 25 TO 32KTS THROUGH MONDAY MORNING.
VARIABLE CIGS ARE EXPECTED THROUGH EARLY EVENING AS MVFR CIGS
BREAK OUT TO VFR AT TIMES. EVENTUALLY MVFR/IFR CIGS AND VSBYS WILL
SETTLE IN. SOME OF THE PRECIPITATION MAY START AS RAIN...THEN
CHANGE OVER TO SNOW THIS EVENING AND OVERNIGHT. THE STRONG WINDS
COMBINED WITH THE SNOW SHOULD REDUCE VSBYS TO IFR AND LOCALLY
LIFR. THE BULK OF THE FALLING SNOW SHOLD BE EAST OF THE TAFS BY
12Z WITH MVFR CIGS FOR MUCH OF THE MORNING.
&&
.PREV DISCUSSION... /ISSUED 549 AM CST SUN JAN 22 2012/
AVIATION...
12Z TAFS FOR KOMA...KLNK...KOFK.
APPROACHING COLD FRONT WILL RESULT IN DETERIORATING CONDITIONS
THIS AFTERNOON. AT KOMA THOUGH...WARM/MOIST OVERRUNNING SITUATION
THIS MORNING CREATING FAVORABLE CONDITIONS FOR -FZDZ AND IFR CIGS
BTWN 12Z-15Z. OTHERWISE...AFOREMENTIONED COLD FRONT WILL BE
PUSHING ACROSS ERN NEB BY EARLY AFTERNOON. SOUTHERLY WIND GUSTS
AROUND 30KT EXPECTED WITH A GRADUAL SHIFT TO NORTHWEST LEADING UP
TO FRONTAL PASSAGE...18Z AT KOFK...21Z AT KOMA...19Z AT KLNK.
BTWN 23/00Z-06Z -SN/BLSN WILL DROP CONDITIONS DOWN TO IFR CAT. VFR
CIGS THEN PREVAILING THRU THE RST OF THE FCST PD WITH NW WINDS
REMAINING GUSTY AROUND 25KT. CROSS WIND ACTIVITY MAY BE AN ISSUE
AT ALL TERMINALS LEADING UP TO FRONTAL PASSAGE.
DEE
PREV DISCUSSION... /ISSUED 336 AM CST SUN JAN 22 2012/
PRECIPITATION CHANCES/TYPES/AMOUNTS THROUGH TONIGHT REMAIN THE
PRIMARY FORECAST CONCERNS.
STRONG MID LEVEL SHORTWAVE TROUGH WAS MOVING THROUGH THE FOUR
CORNERS REGION THIS MORNING. TROUGH AXIS IS EXPECTED TO SHARPEN THIS
MORNING THEN MOVE INTO EASTERN NEBRASKA LATE THIS AFTERNOON. MODELS
HAVE COME INTO BETTER CONSENSUS REGARDING TIMING OF THIS SYSTEM...
AND ONLY DIFFER SLIGHTLY REGARDING STRENGTH. STRONG SOUTHWEST MID
LEVEL JET WAS INDUCING LOWERING PRESSURES ALONG THE LEE OF THE
ROCKIES THIS MORNING...AND IN TURN WAS PRODUCING MOIST SOUTHEAST
FLOW ACROSS EASTERN NEBRASKA AND WESTERN IOWA. STRATUS HAS FORMED
ACROSS AND ADVECTED INTO PARTS OF THE CWA AS OF 3 AM...AND SHOULD
COVER MOST OF OUR AREA BY SUNRISE. STRONG 50KT LOW LEVEL JET WAS
HELPING TO PRODUCE WEAK UPWARD VERTICAL MOTION ACROSS THE
CWA...BUT AS OF YET HAS FAILED TO PRODUCE DRIZZLE. VISIBILITIES
HAVE BEEN SLOWLY COMING DOWN...BUT IT LOOKS LIKE IT WILL TAKE A
WHILE BEFORE POTENTIAL DRIZZLE FORMS. STILL IS A POSSIBILITY THIS
MORNING...SO WILL INCLUDE PATCHY FREEZING DRIZZLE FOR MOST OF THE
AREA.
MORE WIDESPREAD PRECIPITATION LOOKS TO HOLD OFF UNTIL THE AFTERNOON
WITH APPROACH OF MID LEVEL SYSTEM. SURFACE LOW IS FORECAST TO MOVE
ACROSS NORTHERN KANSAS TODAY AND REACH NORTHWEST MISSOURI BY THIS
EVENING. INVERTED TROUGH/COLD FRONT SHOULD BE THROUGH THE CWA BY
THEN. AHEAD OF THE TROUGH/FRONT...DRY SLOT WILL LIKELY SQUELCH
PRECIPITATION FOR AT LEAST THE EARLY AFTERNOON AND COULD BRING A FEW
BREAKS IN CLOUD COVER. HOWEVER SURFACE FRONT AND UPPER TROUGH WILL
INVADE OUR WESTERN CWA EARLY IN THE AFTERNOON...THEN REACH THE
MISSOURI RIVER BY 00Z. MOST OF THE PRECIPITATION WILL LAG THE COLD
FRONT...NEARER MID LEVEL DEFORMATION ZONE...AND WILL FOCUS ON
NORTHEAST NEBRASKA BY LATE AFTERNOON AND SWEEPING THROUGH THE REST
OF EASTERN NEBRASKA AND WESTERN IOWA DURING THE EVENING. HAVE
INCREASED POPS IN OUR WESTERN CWA THIS AFTERNOON THEN ACROSS THE
REST OF OUR AREA THIS EVENING. TEMPERATURE PROFILES ON MODEL
SOUNDINGS AND PARTIAL THICKNESSES SUGGEST MAINLY A SNOW EVENT IN OUR
NORTHWEST CWA...GENERALLY WEST AND NORTH OF NORFOLK...WITH
NEAR-SURFACE WARM LAYER KEEPING A RAIN SNOW MIX POSSIBLE IN THE REST
OF EASTERN NEBRASKA AND SOUTHWEST IOWA MUCH OF THE AFTERNOON.
FOCUSED LIFT IN OUR NORTHWEST CWA LATE IN THE DAY COULD PRODUCE A
QUICK INCH OF SNOW THERE...THEN ANOTHER INCH DURING THE EARLY
EVENING AS SYSTEM SWINGS EAST. AREAS TO THE EAST AND SOUTH COULD SEE
AN INCH OF SNOW DURING THE EVENING AFTER LOW LAYERS COOL...BUT
MUCH ACCUMULATION BEFORE THE SUN GOES DOWN AND COLD AIR PLUNGES
SOUTHEAST WILL BE HARD TO COME BY.
COINCIDENT WITH SNOWFALL IN NORTHEAST NEBRASKA...NORTHWEST WINDS OF
20 TO 30 MPH WITH HIGHER GUSTS WILL OCCUR...AND COULD CAUSE A PERIOD
OF DRASTICALLY REDUCED VISIBILITIES DURING THE LATE AFTERNOON AND
EVENING. DESPITE SNOW AMOUNTS EXPECTED TO BE LESS THAN 3 INCHES...
WILL ISSUE A WINTER WEATHER ADVISORY FOR PARTS OF NORTHEAST NEBRASKA
GENERALLY NORTH OF NORFOLK.
MOST OF THE SNOW SHOULD BE MOVING OUT OF OUR AREA AFTER
MIDNIGHT...WITH WEST CENTRAL IOWA POTENTIALLY SEEING LINGERING SNOWS
THROUGH SUNRISE MONDAY. CLOUDS WILL BE CLEARING WEST TO EAST MONDAY
MORNING WITH WINDS GRADUALLY DIMINISHING AS PRESSURE GRADIENT
SLACKENS. WITH ANY NEW SNOWFALL AND LACK OF STRONG WARM
ADVECTION...EXPECT TEMPERATURES WILL STRUGGLE TO REACH FREEZING IN
THE NORTH AND EAST. THEN A QUICK COOL DOWN MONDAY EVENING WITH LIGHT
WINDS AND CLEAR SKIES WILL ALLOW TEMPS IN THE NORTH TO DROP BELOW
ZERO OVER FRESH SNOW COVER.
A WARMING TREND IS EXPECTED TUESDAY AS SOUTH WINDS KICK IN AHEAD OF
OUR NEXT SHORTWAVE SWINGING THROUGH THE PLAINS. FOCUS FOR
PRECIPITATION WITH THIS SYSTEM WILL BE TO OUR SOUTH WHERE CORE OF
UPPER SYSTEM WILL BE...BUT MODELS ARE STILL KICKING OUT LIGHT
PRECIPITATION ACROSS OUR AREA. SO SEE NO REASON TO REMOVE SMALL
CHANCES TUESDAY NIGHT.
THE REST OF THE WEEK INTO THE WEEKEND LOOKS DRY WITH TEMPERATURES AT
OR ABOVE NORMAL. UPPER FLOW IS GENERALLY ZONAL WITH RIPPLES OF
ENERGY MOVING ACROSS THE NORTHERN PLAINS BRINGING SLIGHT
WARMING/COOLING AHEAD/BEHIND EACH WAVE.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM CST
MONDAY FOR NEZ011-012-016>018-030>032-042.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1237 PM EST SUN JAN 22 2012
.SYNOPSIS...
COOL AND MOIST CONDITIONS WILL PREVAIL TODAY AS HIGH PRESSURE
WEDGES IN FROM THE NORTH. A WARM FRONT WILL LIFT NORTH ACROSS THE
REGION MONDAY. A COLD FRONT IS EXPECTED TO CROSS THE AREA MONDAY
NIGHT INTO TUESDAY. HIGH PRESSURE WILL FOLLOW LATE TUESDAY THROUGH
MID WEEK. ANOTHER FRONT WILL APPROACH FROM THE NORTH LATE THURSDAY
WHILE A MORE POTENT LOW PRESSURE SYSTEM MOVES IN FROM THE GULF COAST
FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1200 PM SUNDAY...NO MAJOR CHANGES OTHER THAN TO CONTINUE TO
ADJUST TEMPS DOWNWARD TODAY. ALWAYS TRICKY TO DETERMINE JUST HOW
WARM IT WILL GET IN THESE WEDGE SCENARIOS...AND THIS CASE IS NO
DIFFERENT. EXPECT MAX TEMPS THIS AFTN TO REMAIN BELOW 45 ACROSS MOST
OF THE REGION...WITH SOME UPPER 40S ALONG THE SOUTHEAST COAST.
OTHERWISE...FORECAST REMAINS ON TRACK WITH PREVIOUS DISCUSSION BELOW:
AS OF 930 AM SUNDAY...COLD FRONT HAS PUSHED AS FAR SOUTH AS THE
GA/FL STATE LINE...AND HIGH PRESSURE CONTINUES TO WEDGE DOWN THROUGH
THE MID ATLANTIC AND INTO THE CAROLINAS. WIDESPREAD OVERCAST LOW
CLOUDINESS AND DRIZZLE ONGOING ACROSS MUCH OF THE AREA WILL
CONTINUE...AND POSSIBLY EXPAND IN COVERAGE THIS AFTERNOON. TIME
HEIGHTS AND FORECAST SOUNDINGS DEPICT FULL SATURATION BENEATH THE
FRONTAL INVERSION...WHICH IS BEING WRUNG OUT BY ANY WEAK IMPULSES
THAT PUSH THROUGH IN THE MID LEVELS. ADDITIONALLY...ISENTROPIC
ANALYSIS REVEALS ONLY WEAK LIFT ON THE 290K SURFACE...BUT IN A FULLY
SATURATED ENVIRONMENT THIS IS ENOUGH TO PRODUCE DRIZZLE. HAVE KEPT
POP SILENT SINCE IT IS DOUBTFUL ANY PLACES WILL MEASURE MORE THAN A
TRACE...BUT A FEW SPOTS MAY MEASURE 0.01 INCHES.
LATEST MSAS ANALYSIS HAS THE WEDGE STRENGTHENING...AND HRRR 3-HR
PRESSURE TENDENCIES CONTINUE TO RISE. THIS INCREASING
PRESSURE...STRENGTHENING WEDGE...WILL KEEP THE AREA LOCKED IN WITH
LOW CLOUDS AND DRIZZLE THROUGH TONIGHT. BECAUSE OF THIS...DIURNAL
TEMPERATURE SWINGS WILL BE QUITE MINIMAL...AND HAVE BUMPED MAX TEMPS
DOWN A BIT BASED OFF CURRENT OBS. EXPECT HIGHS ONLY INTO THE LOWER
40S WELL NW...TO THE UPPER 40S MOST OF THE AREA. A FEW 50 DEGREE
READINGS MAY BE REACHED ALONG THE SOUTH COAST.
WEDGE BEGINS TO BREAK DOWN TONIGHT AS WINDS BECOME MORE
EASTERLY...AND WAA ALOFT BEGINS. CONTINUED ATYPICAL DIURNAL CURVE
TONIGHT...WITH MINS LIKELY BE REACHED BEFORE MIDNIGHT...AND THEN
RISING TOWARDS DAYBREAK MONDAY. AGAIN...VERY LITTLE SWING IN TEMPS
WITH LOWS IN THE LOW/MID 40S BY MIDNIGHT...RISING TO THE MID/UPPER
40S BY 7AM MONDAY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...WITH PROGRESSIVE NATURE TO THE FLOW...THE
SHALLOW COLD WEDGE SHOULD BREAK MONDAY MORNING AS LOW PRESSURE
SYSTEM PUSHES EAST ACROSS THE UPPER MID WEST DRAGGING A COLD FRONT
TOWARD THE AREA. WINDS WILL COME AROUND TO THE SOUTHEAST AND THEN
SOUTH THROUGH MON IN A DEEPER RETURN FLOW. THIS WILL DRIVE TEMPS
BACK UP INTO THE 60S CLOSE TO 70 MON AFTN. SOME UNCERTAINTY EXISTS
AS TO HOW MUCH IN THE WAY OF CLOUDS AND PCP WILL EXIST THROUGH
MONDAY INTO TUESDAY. SHOULD BE SOME LIFT EARLIER ON MONDAY AS WARM
FRONT LIFTS NORTH AND THEN AGAIN AHEAD AND ALONG COLD FRONT AS IT
MOVES INTO AREA. LATEST MODEL RUNS SHOW FRONT LACKING MOISTURE AS IT
MOVES INTO AREA LATE MONDAY BUT IT MAY LINGER ACROSS OR JUST SOUTH
OF AREA AS MID TO UPPER RIDGE BUILDS UP FROM THE GULF INTO MID
WEEK. THEREFORE MAY BE CLOUDS AND SLIM CHC OF PCP LINGERING INTO
TUES AND MID TO HIGH CLOUDS WILL STREAM INTO AREA IN WESTERLY FLOW
ALOFT AS ANOTHER SYSTEM DEVELOPS ALONG WESTERN GULF COAST. AFTER
WAA ON MONDAY...850 TEMPS LEVEL OFF THROUGH THE REMAINDER OF THE
PERIOD. MAY SEE A SHALLOW COOL POOL OF AIR MOVE IN FINALLY LATE
TUES INTO EARLY WED BUT OVERALL EXPECT TEMPS TO MAKE IT INTO THE
60S ON TUES AGAIN.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...MID TO UPPER RIDGE WILL SLIP OFF THE COAST
WITH A DEEP SW FLOW SETTING UP WED THROUGH FRI AS LOW PRESSURE
SYSTEM MOVES EAST THROUGH THE GULF COAST STATES INTO THE
SOUTHEAST. LIGHT NORTHERLY SFC WINDS BEHIND COLD FRONT EARLY WED WILL
SHIFT AROUND ONCE AGAIN AS RETURN FLOW SETS UP LATE WED. THIS WILL
PROVIDE DEEPER LAYER MOISTURE WITH PCP WATER VALUES REMAINING
ABOVE AN INCH THROUGH MUCH OF THE PERIOD. MOST OF THIS MOISTURE
WILL BE IN THE WAY OF MID TO UPPER LEVEL CLOUDS STREAMING INTO THE
AREA UNTIL THURS NIGHT WHEN ANOTHER COLD FRONT MAKES IT WAY DOWN
FROM THE NORTH. THIS FRONT WILL MOVE SOUTH BUT WILL NOT MAKE IT
MUCH FARTHER THAN LOCAL AREA BEFORE STORM SYSTEM MOVES EAST FROM
THE GULF PUSHING THIS BOUNDARY BACK NORTH. THE BEST CHC OF PCP
WILL COME FRI INTO SAT AS SHORTWAVE DRIVES THIS SYSTEM INTO AND
THROUGH THE CAROLINAS FROM THE WEST SOUTHWEST. COLD AND DRY HIGH
PRESSURE WILL MOVE IN BEHIND COLD FRONT LATE SAT INTO SUN. TEMPS
WILL REMAIN ABOVE 60 FOR HIGHS UNTIL FRONT MOVES THROUGH ON SAT
ALLOWING COLDER AIR TO MAKE ITS WAY IN FOR LATE SAT INTO SUNDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...WIDESPREAD IFR LEVEL CEILINGS ARE CONTINUING EARLY THIS
AFTERNOON...EXCEPT AT CRE WHERE CEILINGS HAVE LIFTED TO BORDERLINE
MVFR. AREAS OF FOG ARE DECREASING...WITH MVFR VISIBILITIES AT ILM
EXPECTED TO BECOME VFR SHORTLY.
CONFIDENCE HAS LOWERED BUT STILL EXPECT IFR CEILINGS TO LIFT AT
TIMES TO LOW MVFR LEVELS AROUND 1K THIS AFTERNOON. NORTH TO
NORTHEAST WINDS 5-8 KNOTS ARE EXPECTED TO CONTINUE THROUGH THE
AFTERNOON HOURS. THE IMPROVEMENT IN CEILINGS WILL BE TEMPORARY AS
THE SURFACE HIGH IS EXPECTED TO RETREAT BACK TO THE NORTH LATER
TODAY. AS IT DOES THE FRONTAL INVERSION IS EXPECTED TO LOWER. WITH
COPIOUS MOISTURE TRAPPED AT THE INVERSION LEVEL CONFIDENCE IS
MODERATE TO HIGH THAT CEILINGS WILL DROP BACK TO IFR LEVELS BY THIS
EVENING. CEILINGS WILL LIKELY DROP TO CAT B CEILINGS AROUND
MIDNIGHT.
AS WINDS BECOME EAST TO SOUTHEAST MONDAY MORNING CONFIDENCE IS
MODERATE TO HIGH VISIBILITIES WILL IMPROVE TO VFR AS CEILINGS LIFT
TO MVFR LEVELS BY MID-MORNING. COULD BE SOME LIGHT RAIN NEAR THE
FLO/LBT TERMINALS BY MID-MORNING
EXTENDED OUTLOOK...VFR TO DEVELOP MONDAY LATE WITH A SLIGHT CHANCE
OF SHOWERS AS A WARM FRONT WORKS NORTH. LOW CONFIDENCE FOR MORNING
FOG WEDNESDAY AND THURSDAY MORNINGS. CHANCE OF SHOWERS/TEMPO IFR
FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1200 PM SUNDAY...HAVE EXPIRED SCEC FOR NORTHERN WATERS DUE TO
RELAXING OF WINDS AND SEAS. FORECAST REMAINS ON TRACK WITH SEAS
DROPPING TO 3-4 FT THROUGH TONIGHT. PREVIOUS DISCUSSION BELOW:
AS OF 930 AM SUNDAY...SCEC CONTINUES FOR AMZ250 AND AMZ252 WITH THE
BUOYS REPORTING WINDS STILL GUSTING TO 25 KTS ON NE SURGE. SEAS ARE
MOSTLY 3-4 FT...BUT WITH FRYING PAN REPORTING 6 FT...EXPECT WAVE
HEIGHTS NEAR THE 20 NM BOUNDARY ARE CRESTING AT 5 FT IF NOT SLIGHTLY
HIGHER...WITH A SHORT PERIOD NE WIND WAVE CONTROLLING THE SPECTRUM.
STILL EXPECT TO DROP THE SCEC AROUND NOON...BUT IF WEDGE CONTINUES
TO STRENGTHEN THIS COULD KEEP WINDS AND SEAS ELEVATED..AND PROMPT AN
EXTENSION. ATTM EXPECT WINDS TO EASE TO 10-15 KTS THIS AFTN AND
TONIGHT...PRODUCING NE WIND WAVES OF 3-4 FT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...WINDS WILL SHIFT AROUND TO THE SOUTHEAST AND
THEN SOUTH IN AN INCREASING RETURN FLOW ONCE AGAIN MON. WIND WILL
REACH 15 TO 20 KTS LATE MON. THIS WILL PUSH SEAS UP AGAIN INTO THE 3
TO 5 FT RANGE BUT LATEST WNA RUNS KEEP SEAS BELOW SCA THRESHOLDS
FOR MON NIGHT AS COLD FRONT APPROACHES AND MOVES THROUGH. COLD
FRONT MAY BE SLOWER TO MOVE THROUGH WITH LONGER PERIOD OF SW TO W
WINDS BEFORE FINALLY VEERING AROUND LATE TUES. SEAS WILL DECREASE BY
LATE TUES INTO TUES NIGHT AS FRONT MOVES SOUTH WITH DIMINISHING
NORTHERLY FLOW.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...WINDS WILL VEER AROUND FROM THE NORTHEAST TO
EAST AND EVENTUALLY SOUTH WEDNESDAY INTO THURSDAY AS FRONT PUSHES
BACK NORTH AND STORM SYSTEM APPROACHES FROM THE GULF COAST. SEAS
DOWN TO LESS THAN 3 FT WEDNESDAY WILL INCREASE AGAIN AS SOUTHERLY
RETURN FLOW INCREASES UP TO 15 TO 20 KTS ONCE AGAIN LATE THURS. THIS
WILL DRIVE SEAS BACK UP TO 3 TO 5 FT THURSDAY INTO FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WEISS
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS NORMAN OK
1155 AM CST SUN JAN 22 2012
.UPDATE...
WILL BE EXPANDING RED FLAG WARNING UP INTO SOUTHWEST OKLAHOMA.
30
&&
.PREV DISCUSSION... /ISSUED 1115 AM CST SUN JAN 22 2012/
.AVIATION...
MAIN ISSUE FOR THIS PERIOD WILL BE VERY STRONG WINDS WITH TWO FRONTS
MOVING THROUGH EARLY IN THE PERIOD. PAC FRONT ALONG THE WRN OK
BORDER LATE THIS MORNING WILL MOVE THROUGH AREA SITES BY MID
AFTERNOON WITH WINDS BECOMING MORE WESTERLY AND INCREASING.
SECONDARY FRONT FROM NE NM INTO WRN KS LATE MORNING WILL DROP SEWD
INTO NW OK EARLY THIS AFTERNOON THEN SWEEP THROUGH THE REMAINDER OF
THE AREA BY EARLY EVENING. WINDS WILL BE VERY STRONG BEHIND BOTH
FRONTS WITH GUSTS OF 35 TO 45 KTS COMMON. WIDESPREAD BLOWING DUST
EMANATING FROM W TX WILL LIKELY SPREAD INTO PARTS OF WRN OK AND N TX
AND WILL INCLUDE VSBY RESTRICTIONS FOR A FEW HOURS THIS AFTERNOON.
ALSO A FEW HIGH BASED SHOWERS MAY IMPACT NRN OK SITES THIS AFTERNOON
AND EARLY EVENING BENEATH COLD UPPER LOW. A REL BRIEF PERIOD OF
VFR/MVFR CIGS MAY BRIEFLY SPREAD INTO PARTS OF NRN CENTRAL OK LATE
AFTERNOON/EARLY EVENING BEFORE CLEARING FROM THE SW AS SURFACE LOW
LIFTS RAPIDLY NEWD.
&&
.PREV DISCUSSION... /ISSUED 1040 AM CST SUN JAN 22 2012/
.UPDATE...
WILL DO A QUICK UPDATE TO INTRO SOME BLOWING DUST INTO GRIDS ACROSS
SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS.
NO CHANGES TO TODAY GRIDS AT THIS TIME. HOWEVER WILL NEED TO CLOSELY
MONITOR TEMPS/DEWPOINTS ACROSS SOUTHWEST OK TODAY FOR THE
POSSIBILITY OF DEVELOPMENT OF RED FLAG CONDITIONS INTO SOUTHWEST
OKLAHOMA. SHORT RANGE MODELS SHOW LOWER DEWPOINTS MOVING INTO THE
AREA THIS AFTN AND THIS WOULD ALLOW RH TO DROP BELOW 20% THRESHOLD.
MORNING MODELS ALSO INDICATE THAT THE STRONGEST WINDS WILL LIKELY
OCCUR DURING THE MIDDLE PART OF THE AFTN ACROSS PORTIONS OF WESTERN
AND NORTHWESTERN OKLAHOMA WITH THE PASSAGE OF SECONDARY FRONT...
WHICH WILL SHIFT THE SFC WINDS MORE TO THE NORTHWEST. AT THAT POINT
WE COULD SEE A PERIOD OF A FEW HOURS WITH GUSTS OVER 50 MPH WITH A
GRADUAL SHIFT TOWARD NORTH-CENTRAL OKLAHOMA TOWARD SUNSET. WINDS
SHOULD DIMINISH RATHER QUICKLY AS WE DECOUPLE AROUND THIS TIME.
SO... EVEN WITH POSSIBLE LATER START TO THE STRONGEST WINDS... DO
NOT ANTICIPATE ANY CHANGES TO THE WIND ADVISORY/HIGH WIND WARNING
HEADLINES AT THIS TIME.
30
&&
.PREV DISCUSSION... /ISSUED 536 AM CST SUN JAN 22 2012/
.AVIATION...MOIST RETURN FLOW FOR A FEW HOURS THIS MORNING WILL
YIELD LIGHT FOG AND IFR STRATUS AT CENTRAL OKLAHOMA SITES. WINDS
BEGIN THE PERIOD ABOVE 12 KT AT MOST LOCATIONS. LIGHT AND BACKED
SURFACE WINDS AT KLAW WILL CONTINUE TO PROMOTE LLWS UNTIL DEEPER
MIXING BEGINS AROUND 22/15Z. WINDS SET TO VEER TO WESTERLY AND
INCREASE MARKEDLY BEHIND A PACIFIC COLD FRONT...WITH GUSTS ABOVE
30 KT BY 22/18Z. A STRONGER WIND SHIFT WILL FOLLOW IN THE
AFTERNOON HOURS...RESULTING IN A BRIEF PERIOD OF INTENSE WIND...
ESPECIALLY WESTERN OKLAHOMA SITES...WHERE GUSTS MAY EXCEED 45 KT.
SPEEDS WILL DIMINISH RATHER QUICKLY LATE IN THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 405 AM CST SUN JAN 22 2012/
DISCUSSION...ACTIVE WEATHER TODAY WITH HIGH WINDS AND EXTREME FIRE
WEATHER CONDITIONS.
LOW PRESSURE APPROACHING 995 MB WILL TRACK EASTWARD NEAR THE
KANSAS BORDER DURING THE DAYLIGHT HOURS...WHILE A COMPACT MID
LEVEL JET MAX EJECTS SOUTH OF THE SURFACE LOW ACROSS OKLAHOMA AND
NORTH TEXAS. THIS SCENARIO OFTEN LEADS TO SEVERE WIND GUSTS EVEN
IN MID WINTER.
THERE ARE TWO NOTEWORTHY SURFACE BOUNDARIES. A PACIFIC FRONT WILL
REACH INTERSTATE 35 BY NOON TO 1 PM AND CONTINUE EASTWARD.
ALTHOUGH THE LOW LEVEL JET WILL MAKE FOR A BREEZY MORNING...THE
WIND WILL INCREASE MARKEDLY BEHIND THE PACIFIC FRONT...WHERE DEEP
MIXING WILL OCCUR. WE EXPANDED THE WIND ADVISORY TO ACCOUNT FOR
THIS. MEANWHILE...A SECOND COLD FRONT EMANATING FROM THE
ROCKIES/HIGH PLAINS WILL DIVE INTO WESTERN OK AND WESTERN NORTH TX
THIS AFTERNOON. TRENDS IN THE NAM AND RUC SUGGEST GUSTS ABOVE 50
OR 60 MPH WILL OCCUR WITH THIS FRONT...AND WE HAVE ISSUED A HIGH
WIND WARNING FOR PORTIONS OF WESTERN OKLAHOMA.
THE RUC ALSO SUGGESTS HIGH WIND CRITERIA COULD BE MET OVER FAR
WESTERN NORTH TEXAS BENEATH THE MID LEVEL JET...AND EVEN PRIOR TO
THE ARRIVAL OF THE SECOND...STRONGER FRONT. WE WERE NOT QUITE
CONVINCED BECAUSE MOST OF THE COLD ADVECTION BEHIND THE PACIFIC
FRONT OCCURS PRIOR TO DEEP MIXING IN THAT AREA...AND THE TIGHTER
GRADIENTS ASSOCIATED WITH THE SECOND FRONT WILL PASS NORTH THROUGH
OKLAHOMA. THE DAY SHIFT MAY NEED TO EXPAND THE HIGH WIND WARNING
INTO TEXAS IF THE OBSERVATIONS SUGGEST IT IS NEEDED. WE ADJUSTED
THE RED FLAG WARNING BASED ON THE HUMIDITY FORECAST...ADDING ONLY
CLAY COUNTY.
THE WIND WILL QUIET DOWN BY MONDAY MORNING...AND WE GO BACK TO OUR
ACTIVE WESTERLY JET ALOFT WITH SEASONABLE OR RELATIVELY MILD
TEMPERATURES FOR THE WEEK AHEAD. THE JET WILL BUCKLE ENOUGH FOR A
CLOSED LOW TO PRODUCE RAIN OVER TEXAS AND OKLAHOMA MID
WEEK...BEFORE IT IS RE-ABSORBED IN THE FLOW. IT HAS BEEN DIFFICULT
THIS WINTER TO PREDICT EXACTLY WHERE THE LOW WILL CLOSE OFF...AND
HOW QUICKLY IT WILL BE RE-ABSORBED. IT DOES LOOK...THOUGH...AS IF
THERE IS A FAIRLY GOOD CHANCE OF SOME RAIN ACCUMULATION TUESDAY
NIGHT AND EARLY WEDNESDAY FROM NORTH TEXAS INTO SOUTHERN OKLAHOMA.
THE OPERATIONAL MODEL SOLUTIONS WOULD BRING GREATER RAIN COVERAGE
AND AMOUNTS FARTHER NORTHWARD INTO OKLAHOMA...BUT WE DID NOT
COMMIT IN THAT DIRECTION...AS THE OPERATIONAL RUNS ARE QUITE A BIT
FARTHER NORTH THEN THE VAST MAJORITY OF THE GFS ENSEMBLE MEMBERS.
THE NEXT SHOT OF COLDER WEATHER IS EXPECTED EARLY NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 30 57 35 / 10 0 0 0
HOBART OK 64 31 58 34 / 0 0 0 0
WICHITA FALLS TX 69 34 62 39 / 0 0 0 0
GAGE OK 59 23 54 25 / 20 0 0 0
PONCA CITY OK 62 29 55 31 / 10 10 0 0
DURANT OK 70 39 61 40 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR OKZ007-008-012-013-018>020-023>030-036>038-044.
HIGH WIND WARNING FROM 11 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR OKZ004>006-009>011-014>017-021-022-033>035.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
OKZ031-032-039>042-045-046-050.
TX...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR TXZ083>089.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
TXZ090.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
26/22/22
BURKE
AREA FORECAST DISCUSSION
NWS NORMAN OK
1115 AM CST SUN JAN 22 2012
.AVIATION...
MAIN ISSUE FOR THIS PERIOD WILL BE VERY STRONG WINDS WITH TWO FRONTS
MOVING THROUGH EARLY IN THE PERIOD. PAC FRONT ALONG THE WRN OK
BORDER LATE THIS MORNING WILL MOVE THROUGH AREA SITES BY MID
AFTERNOON WITH WINDS BECOMING MORE WESTERLY AND INCREASING.
SECONDARY FRONT FROM NE NM INTO WRN KS LATE MORNING WILL DROP SEWD
INTO NW OK EARLY THIS AFTERNOON THEN SWEEP THROUGH THE REMAINDER OF
THE AREA BY EARLY EVENING. WINDS WILL BE VERY STRONG BEHIND BOTH
FRONTS WITH GUSTS OF 35 TO 45 KTS COMMON. WIDESPREAD BLOWING DUST
EMANATING FROM W TX WILL LIKELY SPREAD INTO PARTS OF WRN OK AND N TX
AND WILL INCLUDE VSBY RESTRICTIONS FOR A FEW HOURS THIS AFTERNOON.
ALSO A FEW HIGH BASED SHOWERS MAY IMPACT NRN OK SITES THIS AFTERNOON
AND EARLY EVENING BENEATH COLD UPPER LOW. A REL BRIEF PERIOD OF
VFR/MVFR CIGS MAY BRIEFLY SPREAD INTO PARTS OF NRN CENTRAL OK LATE
AFTERNOON/EARLY EVENING BEFORE CLEARING FROM THE SW AS SURFACE LOW
LIFTS RAPIDLY NEWD.
&&
.PREV DISCUSSION... /ISSUED 1040 AM CST SUN JAN 22 2012/
.UPDATE...
WILL DO A QUICK UPDATE TO INTRO SOME BLOWING DUST INTO GRIDS ACROSS
SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS.
NO CHANGES TO TODAY GRIDS AT THIS TIME. HOWEVER WILL NEED TO CLOSELY
MONITOR TEMPS/DEWPOINTS ACROSS SOUTHWEST OK TODAY FOR THE
POSSIBILITY OF DEVELOPMENT OF RED FLAG CONDITIONS INTO SOUTHWEST
OKLAHOMA. SHORT RANGE MODELS SHOW LOWER DEWPOINTS MOVING INTO THE
AREA THIS AFTN AND THIS WOULD ALLOW RH TO DROP BELOW 20% THRESHOLD.
MORNING MODELS ALSO INDICATE THAT THE STRONGEST WINDS WILL LIKELY
OCCUR DURING THE MIDDLE PART OF THE AFTN ACROSS PORTIONS OF WESTERN
AND NORTHWESTERN OKLAHOMA WITH THE PASSAGE OF SECONDARY FRONT...
WHICH WILL SHIFT THE SFC WINDS MORE TO THE NORTHWEST. AT THAT POINT
WE COULD SEE A PERIOD OF A FEW HOURS WITH GUSTS OVER 50 MPH WITH A
GRADUAL SHIFT TOWARD NORTH-CENTRAL OKLAHOMA TOWARD SUNSET. WINDS
SHOULD DIMINISH RATHER QUICKLY AS WE DECOUPLE AROUND THIS TIME.
SO... EVEN WITH POSSIBLE LATER START TO THE STRONGEST WINDS... DO
NOT ANTICIPATE ANY CHANGES TO THE WIND ADVISORY/HIGH WIND WARNING
HEADLINES AT THIS TIME.
30
&&
.PREV DISCUSSION... /ISSUED 536 AM CST SUN JAN 22 2012/
.AVIATION...MOIST RETURN FLOW FOR A FEW HOURS THIS MORNING WILL
YIELD LIGHT FOG AND IFR STRATUS AT CENTRAL OKLAHOMA SITES. WINDS
BEGIN THE PERIOD ABOVE 12 KT AT MOST LOCATIONS. LIGHT AND BACKED
SURFACE WINDS AT KLAW WILL CONTINUE TO PROMOTE LLWS UNTIL DEEPER
MIXING BEGINS AROUND 22/15Z. WINDS SET TO VEER TO WESTERLY AND
INCREASE MARKEDLY BEHIND A PACIFIC COLD FRONT...WITH GUSTS ABOVE
30 KT BY 22/18Z. A STRONGER WIND SHIFT WILL FOLLOW IN THE
AFTERNOON HOURS...RESULTING IN A BRIEF PERIOD OF INTENSE WIND...
ESPECIALLY WESTERN OKLAHOMA SITES...WHERE GUSTS MAY EXCEED 45 KT.
SPEEDS WILL DIMINISH RATHER QUICKLY LATE IN THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 405 AM CST SUN JAN 22 2012/
DISCUSSION...ACTIVE WEATHER TODAY WITH HIGH WINDS AND EXTREME FIRE
WEATHER CONDITIONS.
LOW PRESSURE APPROACHING 995 MB WILL TRACK EASTWARD NEAR THE
KANSAS BORDER DURING THE DAYLIGHT HOURS...WHILE A COMPACT MID
LEVEL JET MAX EJECTS SOUTH OF THE SURFACE LOW ACROSS OKLAHOMA AND
NORTH TEXAS. THIS SCENARIO OFTEN LEADS TO SEVERE WIND GUSTS EVEN
IN MID WINTER.
THERE ARE TWO NOTEWORTHY SURFACE BOUNDARIES. A PACIFIC FRONT WILL
REACH INTERSTATE 35 BY NOON TO 1 PM AND CONTINUE EASTWARD.
ALTHOUGH THE LOW LEVEL JET WILL MAKE FOR A BREEZY MORNING...THE
WIND WILL INCREASE MARKEDLY BEHIND THE PACIFIC FRONT...WHERE DEEP
MIXING WILL OCCUR. WE EXPANDED THE WIND ADVISORY TO ACCOUNT FOR
THIS. MEANWHILE...A SECOND COLD FRONT EMANATING FROM THE
ROCKIES/HIGH PLAINS WILL DIVE INTO WESTERN OK AND WESTERN NORTH TX
THIS AFTERNOON. TRENDS IN THE NAM AND RUC SUGGEST GUSTS ABOVE 50
OR 60 MPH WILL OCCUR WITH THIS FRONT...AND WE HAVE ISSUED A HIGH
WIND WARNING FOR PORTIONS OF WESTERN OKLAHOMA.
THE RUC ALSO SUGGESTS HIGH WIND CRITERIA COULD BE MET OVER FAR
WESTERN NORTH TEXAS BENEATH THE MID LEVEL JET...AND EVEN PRIOR TO
THE ARRIVAL OF THE SECOND...STRONGER FRONT. WE WERE NOT QUITE
CONVINCED BECAUSE MOST OF THE COLD ADVECTION BEHIND THE PACIFIC
FRONT OCCURS PRIOR TO DEEP MIXING IN THAT AREA...AND THE TIGHTER
GRADIENTS ASSOCIATED WITH THE SECOND FRONT WILL PASS NORTH THROUGH
OKLAHOMA. THE DAY SHIFT MAY NEED TO EXPAND THE HIGH WIND WARNING
INTO TEXAS IF THE OBSERVATIONS SUGGEST IT IS NEEDED. WE ADJUSTED
THE RED FLAG WARNING BASED ON THE HUMIDITY FORECAST...ADDING ONLY
CLAY COUNTY.
THE WIND WILL QUIET DOWN BY MONDAY MORNING...AND WE GO BACK TO OUR
ACTIVE WESTERLY JET ALOFT WITH SEASONABLE OR RELATIVELY MILD
TEMPERATURES FOR THE WEEK AHEAD. THE JET WILL BUCKLE ENOUGH FOR A
CLOSED LOW TO PRODUCE RAIN OVER TEXAS AND OKLAHOMA MID
WEEK...BEFORE IT IS RE-ABSORBED IN THE FLOW. IT HAS BEEN DIFFICULT
THIS WINTER TO PREDICT EXACTLY WHERE THE LOW WILL CLOSE OFF...AND
HOW QUICKLY IT WILL BE RE-ABSORBED. IT DOES LOOK...THOUGH...AS IF
THERE IS A FAIRLY GOOD CHANCE OF SOME RAIN ACCUMULATION TUESDAY
NIGHT AND EARLY WEDNESDAY FROM NORTH TEXAS INTO SOUTHERN OKLAHOMA.
THE OPERATIONAL MODEL SOLUTIONS WOULD BRING GREATER RAIN COVERAGE
AND AMOUNTS FARTHER NORTHWARD INTO OKLAHOMA...BUT WE DID NOT
COMMIT IN THAT DIRECTION...AS THE OPERATIONAL RUNS ARE QUITE A BIT
FARTHER NORTH THEN THE VAST MAJORITY OF THE GFS ENSEMBLE MEMBERS.
THE NEXT SHOT OF COLDER WEATHER IS EXPECTED EARLY NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 30 57 35 / 10 0 0 0
HOBART OK 64 31 58 34 / 0 0 0 0
WICHITA FALLS TX 69 34 62 39 / 0 0 0 0
GAGE OK 59 23 54 25 / 20 0 0 0
PONCA CITY OK 62 29 55 31 / 10 10 0 0
DURANT OK 70 39 61 40 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR OKZ007-008-012-013-018>020-023>030-036>038-044.
HIGH WIND WARNING FROM 11 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR OKZ004>006-009>011-014>017-021-022-033>035.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
OKZ031-032-039>042-045-046-050.
TX...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR TXZ083>089.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
TXZ090.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
26/22/22
BURKE
AREA FORECAST DISCUSSION
NWS NORMAN OK
1040 AM CST SUN JAN 22 2012
.UPDATE...
WILL DO A QUICK UPDATE TO INTRO SOME BLOWING DUST INTO GRIDS ACROSS
SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS.
NO CHANGES TO TODAY GRIDS AT THIS TIME. HOWEVER WILL NEED TO CLOSELY
MONITOR TEMPS/DEWPOINTS ACROSS SOUTHWEST OK TODAY FOR THE
POSSIBILITY OF DEVELOPMENT OF RED FLAG CONDITIONS INTO SOUTHWEST
OKLAHOMA. SHORT RANGE MODELS SHOW LOWER DEWPOINTS MOVING INTO THE
AREA THIS AFTN AND THIS WOULD ALLOW RH TO DROP BELOW 20% THRESHOLD.
MORNING MODELS ALSO INDICATE THAT THE STRONGEST WINDS WILL LIKELY
OCCUR DURING THE MIDDLE PART OF THE AFTN ACROSS PORTIONS OF WESTERN
AND NORTHWESTERN OKLAHOMA WITH THE PASSAGE OF SECONDARY FRONT...
WHICH WILL SHIFT THE SFC WINDS MORE TO THE NORTHWEST. AT THAT POINT
WE COULD SEE A PERIOD OF A FEW HOURS WITH GUSTS OVER 50 MPH WITH A
GRADUAL SHIFT TOWARD NORTH-CENTRAL OKLAHOMA TOWARD SUNSET. WINDS
SHOULD DIMINISH RATHER QUICKLY AS WE DECOUPLE AROUND THIS TIME.
SO... EVEN WITH POSSIBLE LATER START TO THE STRONGEST WINDS... DO
NOT ANTICIPATE ANY CHANGES TO THE WIND ADVISORY/HIGH WIND WARNING
HEADLINES AT THIS TIME.
30
&&
.PREV DISCUSSION... /ISSUED 536 AM CST SUN JAN 22 2012/
.AVIATION...MOIST RETURN FLOW FOR A FEW HOURS THIS MORNING WILL
YIELD LIGHT FOG AND IFR STRATUS AT CENTRAL OKLAHOMA SITES. WINDS
BEGIN THE PERIOD ABOVE 12 KT AT MOST LOCATIONS. LIGHT AND BACKED
SURFACE WINDS AT KLAW WILL CONTINUE TO PROMOTE LLWS UNTIL DEEPER
MIXING BEGINS AROUND 22/15Z. WINDS SET TO VEER TO WESTERLY AND
INCREASE MARKEDLY BEHIND A PACIFIC COLD FRONT...WITH GUSTS ABOVE
30 KT BY 22/18Z. A STRONGER WIND SHIFT WILL FOLLOW IN THE
AFTERNOON HOURS...RESULTING IN A BRIEF PERIOD OF INTENSE WIND...
ESPECIALLY WESTERN OKLAHOMA SITES...WHERE GUSTS MAY EXCEED 45 KT.
SPEEDS WILL DIMINISH RATHER QUICKLY LATE IN THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 405 AM CST SUN JAN 22 2012/
DISCUSSION...ACTIVE WEATHER TODAY WITH HIGH WINDS AND EXTREME FIRE
WEATHER CONDITIONS.
LOW PRESSURE APPROACHING 995 MB WILL TRACK EASTWARD NEAR THE
KANSAS BORDER DURING THE DAYLIGHT HOURS...WHILE A COMPACT MID
LEVEL JET MAX EJECTS SOUTH OF THE SURFACE LOW ACROSS OKLAHOMA AND
NORTH TEXAS. THIS SCENARIO OFTEN LEADS TO SEVERE WIND GUSTS EVEN
IN MID WINTER.
THERE ARE TWO NOTEWORTHY SURFACE BOUNDARIES. A PACIFIC FRONT WILL
REACH INTERSTATE 35 BY NOON TO 1 PM AND CONTINUE EASTWARD.
ALTHOUGH THE LOW LEVEL JET WILL MAKE FOR A BREEZY MORNING...THE
WIND WILL INCREASE MARKEDLY BEHIND THE PACIFIC FRONT...WHERE DEEP
MIXING WILL OCCUR. WE EXPANDED THE WIND ADVISORY TO ACCOUNT FOR
THIS. MEANWHILE...A SECOND COLD FRONT EMANATING FROM THE
ROCKIES/HIGH PLAINS WILL DIVE INTO WESTERN OK AND WESTERN NORTH TX
THIS AFTERNOON. TRENDS IN THE NAM AND RUC SUGGEST GUSTS ABOVE 50
OR 60 MPH WILL OCCUR WITH THIS FRONT...AND WE HAVE ISSUED A HIGH
WIND WARNING FOR PORTIONS OF WESTERN OKLAHOMA.
THE RUC ALSO SUGGESTS HIGH WIND CRITERIA COULD BE MET OVER FAR
WESTERN NORTH TEXAS BENEATH THE MID LEVEL JET...AND EVEN PRIOR TO
THE ARRIVAL OF THE SECOND...STRONGER FRONT. WE WERE NOT QUITE
CONVINCED BECAUSE MOST OF THE COLD ADVECTION BEHIND THE PACIFIC
FRONT OCCURS PRIOR TO DEEP MIXING IN THAT AREA...AND THE TIGHTER
GRADIENTS ASSOCIATED WITH THE SECOND FRONT WILL PASS NORTH THROUGH
OKLAHOMA. THE DAY SHIFT MAY NEED TO EXPAND THE HIGH WIND WARNING
INTO TEXAS IF THE OBSERVATIONS SUGGEST IT IS NEEDED. WE ADJUSTED
THE RED FLAG WARNING BASED ON THE HUMIDITY FORECAST...ADDING ONLY
CLAY COUNTY.
THE WIND WILL QUIET DOWN BY MONDAY MORNING...AND WE GO BACK TO OUR
ACTIVE WESTERLY JET ALOFT WITH SEASONABLE OR RELATIVELY MILD
TEMPERATURES FOR THE WEEK AHEAD. THE JET WILL BUCKLE ENOUGH FOR A
CLOSED LOW TO PRODUCE RAIN OVER TEXAS AND OKLAHOMA MID
WEEK...BEFORE IT IS RE-ABSORBED IN THE FLOW. IT HAS BEEN DIFFICULT
THIS WINTER TO PREDICT EXACTLY WHERE THE LOW WILL CLOSE OFF...AND
HOW QUICKLY IT WILL BE RE-ABSORBED. IT DOES LOOK...THOUGH...AS IF
THERE IS A FAIRLY GOOD CHANCE OF SOME RAIN ACCUMULATION TUESDAY
NIGHT AND EARLY WEDNESDAY FROM NORTH TEXAS INTO SOUTHERN OKLAHOMA.
THE OPERATIONAL MODEL SOLUTIONS WOULD BRING GREATER RAIN COVERAGE
AND AMOUNTS FARTHER NORTHWARD INTO OKLAHOMA...BUT WE DID NOT
COMMIT IN THAT DIRECTION...AS THE OPERATIONAL RUNS ARE QUITE A BIT
FARTHER NORTH THEN THE VAST MAJORITY OF THE GFS ENSEMBLE MEMBERS.
THE NEXT SHOT OF COLDER WEATHER IS EXPECTED EARLY NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 30 57 35 / 10 0 0 0
HOBART OK 64 31 58 34 / 0 0 0 0
WICHITA FALLS TX 69 34 62 39 / 0 0 0 0
GAGE OK 59 23 54 25 / 20 0 0 0
PONCA CITY OK 62 29 55 31 / 10 10 0 0
DURANT OK 70 39 61 40 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR OKZ007-008-012-013-018>020-023>030-036>038-044.
HIGH WIND WARNING FROM 11 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR OKZ004>006-009>011-014>017-021-022-033>035.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
OKZ031-032-039>042-045-046-050.
TX...WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CST THIS EVENING
FOR TXZ083>089.
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
TXZ090.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
26/22/22
BURKE
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
336 PM CST SUN JAN 22 2012
.DISCUSSION.../ISSUED AT 336 PM CST/
CHALLENGE IS AT HIGH LEVEL WITH SYSTEM IN THE SHORT TERM...DEALING
WITH A HEALTHY SPLIT FLOW. WATER VAPOR IMAGERY SHOWING FULL LATITUDE
TROUGH PUSH ACROSS THE CENTRAL U.S...WITH SEVERAL PIECES OF ENERGY.
FIRST HAS MOVED PAST AND INTO NORTHWEST MN...SECOND IS LIFTING
THROUGH CENTRAL NEBRASKA...AND THIRD /THE STRONGEST/ LIFTING AROUND
THE BASE IN SOUTHERN KS. THE LATTER WILL DRIVE INTENSE CYCLOGENESIS
WELL EAST OF THE AREA LATER TONIGHT AND MONDAY WITH ITS OWN IMPACT
BEING WINDS...BUT FOCUS WILL BE ON THE MID FEATURE FOR THE EVENING.
LEADING BOUNDARY/INVERTED TROUGH NOW SHIFTED TO NEAR A KRWF TO KSUX
LINE...AND COLLAPSING SOUTHEAST AS ENERGY IN SOUTHERN TROUGH LIFTS
NORTHWARD. TEMPS AHEAD ACROSS NORTHWEST IOWA AREA ALL AT OR ABOVE
FREEZING NOW...WITH THE ONLY AREA STILL HAVING SOME PATCHY FREEZING
DRIZZLE FAR EASTERN SECTIONS OF SW MN AROUND KMWM/KMJQ/KOTG.
SNOWFALL ACROSS MUCH OF THE STATE OTHER THAN THE FAR SOUTHEAST AT
MID AFTERNOON...IN BROAD DIV Q ASSOCIATED WITH THE TROUGH.
PRECIPITATION IS ALSO BREAKING OUT ALONG THE LEADING PV SUPPORT
THROUGH NEBRASKA INTO SOUTHEAST SOUTH DAKOTA. EARLIER MINOR WARM
NOTCH NOTED ON MORNING RAOBS HAS APPARENTLY BEEN WORKED OUT
WITH PRECIPITATION ALL SNOW AT YANKTON PER LATEST WEBCAM IMAGE.
SHORT RANGE MODELS FAIL ON QPF BEING IN THE RIGHT PLACE...BUT HAVE
LESSER PROBLEMS WITH THE DYNAMICS IN MOST...ESPECIALLY IN PLACEMENT
OF THE SIGNIFICANT PV FEATURES. CLOSELY FOLLOWED RUC/NAM ON
THESE...AND RESULT WAS A QUICKER EASTWARD DEVELOPMENT ALONG THE PV
ADVECTION. QUICK PEEK AT LATEST HRRR WOULD SUGGEST THE PROGRESSION
MAY BE EVEN GREATER...AS WILL BE DEMISE OF THE WESTERN SNOW AREA IN
FAVOR OF THIS DEVELOPMENT ACROSS NEBRASKA.
THERMODYNAMICALLY...THIS IS FAR FROM THE MOST EFFICIENT PROFILE WITH
MUCH OF THE LOWER PROFILES IN THE -5 TO -8C RANGE...AND THE LIFT
FAIRLY HIGH. DENDRITIC DEPTH IS LESS THAN 100 HPA...AND REALLY DO
NOT NOTE ANY SIGNIFICANT INSTABILITY TO MAKE USE OF UNTIL MID TO
LATE EVENING WITH SOME APPEARING ABOVE OF MID LEVEL FRONT...SO LOOKS
MORE OF A BROAD AND LESSER FOCUSED EVENT UNTIL BAND DEVELOPS TOWARD
THE EAST. HOWEVER...FAIRLY QUICK PERIOD OF DYNAMIC/THERMODYNAMIC
OVERLAP...SO ANY ENHANCEMENT SHOULD BE SOMEWHAT SHORT TERM...BUT
COULD GET A LITTLE TIME BOOST BY THE SLOWING OF FEATURES DURING MID
LEVEL DEVELOPMENT TO EAST. IMPACT OVERALL WAS TO LOWER SNOWFALL
AMOUNTS BY AN INCH OR SO WEST...AND RAISE BY A HALF INCH TO INCH IN
THE EAST. WHILE MOST...IF NOT ALL OF THE AREA IS LIKELY TO STAY AT
OR BELOW SNOWFALL CRITERIA FOR AN ADVISORY... IT WILL BE THE
COMBINATION OF THE SNOW AND BLOWING SNOW THAT SUPPORTS THE ADVISORY.
THIS INCLUDES AREAS FARTHER EASTWARD WHICH RECEIVED SOME HEAVIER
SNOWFALL IN LAST EVENT. MAIN PUSH OF WINDS LOOKS TO GET GOING IN
THE FAR WEST LATE AFTERNOON TO EARLY EVENING...TOWARD THE I29
CORRIDOR TOWARD MIDNIGHT...SW MN BETWEEN 06Z AND 09Z. APPEARS THAT
GUSTY 20 TO 35 MPH WIND CAN BE EXPECTED AFTER INITIAL PRESSURE RISE
SURGE...AND MORE TYPICAL THROUGH THE EAST BY MONDAY AS THE CYCLONE
STRENGTHENS TO THE EAST. CONTINUED CURRENT ADVISORY...BUT DID EXTEND
THE END TIME TO COVER THE STRONGER WINDS. ADDITIONAL AREA WAS ADDED
OVER THE REMAINDER OF THE AREA FOR THE SNOW/WIND THREAT...BUT
STARTED AS ONE GROUP RATHER THAN PIECEMEAL TO KEEP IT SIMPLE...AND
TO PICK UP ANY LINGERING FREEZING DRIZZLE IN THE FAR EAST.
ON MONDAY...CONDITIONS WILL IMPROVE SOMEWHAT OUTSIDE ANY LINGERING
SNOWFALL WHICH IS LIMITED TO THE FAR EASTERN AREA AS UPPER LOW
DEVELOPS TO THE EAST. THIS DEVELOPMENT WILL KEEP THE GRADIENT
HOLDING ON STRONG THROUGH SW MN AND INTO NW IA THROUGH AT LEAST
MIDDAY IF NOT MID AFTERNOON. FOR THIS REASON...CONTINUED ADVISORY TO
COVER THE BLOWING SNOW POTENTIAL IN THE EASTERN GROUP. TEMPERATURES
LIKELY TO STRUGGLE WITH FRESH SNOW AND MIXED START...SO DO NOT LOOK
FOR MORE THAN A 4-6 DEGREE CLIMB AS SURFACE RIDGE FROM WEST FINALLY
STARTS TO DROP OFF THE WINDS IN THE WEST DURING THE AFTERNOON.
/CHAPMAN
BRISK NORTHWEST WINDS TAPER OFF BY MONDAY NIGHT...AS THE LOW MOVES
WELL EAST OF THE FORECAST AREA AND ARCTIC HIGH PRESSURE SLIPS INTO
THE REGION. WITH A FRESH SNOWPACK...MOSTLY CLEAR SKIES AND WINDS
BECOMING LIGHT...TEMPERATURES SHOULD PLUMMET OVERNIGHT. CONTINUED TO
GO WELL BELOW GUIDANCE WHICH IS NOTORIOUS FOR BEING TOO WARM IN
THESE EVENTS. LOWS SHOULD FALL INTO THE LOWER TEENS AND SINGLE
DIGITS BELOW ZERO.
HIGH PRESSURE SHIFTS EASTWARD ON TUESDAY WHILE THE UPPER FLOW
BECOMES MORE ZONAL. MODEST WARM AIR ADVECTION WILL ALLOW
TEMPERATURES TO IMPROVE INTO THE 20S TO LOWER 30S. A WEAK UPPER
LEVEL WAVE SLIDES THROUGH THE REGION TUESDAY NIGHT WITH LITTLE
IMPACT OTHER THAN AN INCREASE IN CLOUDS.
THE MILDER PATTERN CONTINUE INTO FRIDAY WITH WEST AND SOUTHWEST
WINDS AND LOW LEVEL TEMPERATURES NEAR OR ABOVE FREEZING. EVEN WITH
925 MB TEMPERATURES AS WARM AS +6 OR +8C...IT WILL BE DIFFICULT TO
MIX TO THE SURFACE WITH THE RECENT SNOWPACK IN PLACE. HOWEVER...DO
EXPECT HIGHS TO RISE BACK ABOVE AVERAGE AND HOVER IN THE LOWER TO
MID 30S FOR MUCH OF THE FORECAST AREA. AGAIN...WENT A BIT BELOW
GUIDANCE NUMBERS DURING THE PERIOD WITH THIS IN MIND. A MID LEVEL
WAVE SLIPS ACROSS THE MISSOURI RIVER AREA THURSDAY NIGHT AND EARLY
FRIDAY WITH MEAGER MOISTURE AND LIFT. COULD SQUEEZE OUT A LITTLE
LIGHT PRECIPITATION ACROSS THE SOUTH SO WILL LEAVE MENTION OF A
SLIGHT CHANCE. A REINFORCING SHOT OF COOLER AIR WILL FOLLOW FRIDAY
NIGHT AND SATURDAY WITH BRISK NORTHWEST WINDS.
&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
MESSY WINTRY SCENARIO CONTINUES FOR THIS TAF ISSUANCE. OF IMMEDIATE
CONCERN IS THE ICING THREAT...AND THIS LOOKS TO CONTINUE AT THE
SURFACE FOR AREAS GENERALLY ALONG AND EAST OF HIGHWAY 60 IN
SOUTHWEST MINNESOTA AND NORTHWEST IOWA THROUGH THE EARLY AFTERNOON.
SHALLOW MOISTURE OVER MUCH OF THE AREA WEST TO THE JAMES VALLEY AT
LATE MORNING...WITH CEILINGS IN THE IFR TO LIFR RANGE...AS WELL FOR
VISIBILITIES ALONG AND EAST OF INTERSTATE 29 AREA. AREA OF
PRECIPITATION APPROACHING FROM THE WEST FORCED BY APPROACHING LARGE
SCALE SYSTEM LIKELY HAS ALMOST UNMENTIONABLE WINDOW FOR ANYTHING
OTHER THAN SNOW AS TEMPERATURES COOLING ALOFT ALONG WITH EVAPORATIVE
IMPACTS ABOVE THE SHALLOW MOIST LAYER REMOVE THE 25-50 HPA OF
PROFILE ABOVE FREEZING ON THE MORNING ABR/BIS RAOBS. SNOW BAND WILL
THEN WORK EASTWARD THROUGH TONIGHT...AND FEATURE WIDESPREAD 1/2 TO
1SM VISIBILITIES FOR SEVERAL HOURS. OF ADDED CONCERN WILL BE THE
GUSTY NORTHWEST WINDS DEVELOPING BEHIND THE FRONTAL ZONE...WHICH
WILL LIKELY CONTINUE TO PRODUCE MVFR CONDITIONS IN BLOWING SNOW ON
THE AVERAGE INTO MONDAY MIDDAY ALONG AND EAST OF INTERSTATE 29...AND
LIKELY PERIODS OF IFR OR WORSE VISIBILITIES HEADING TOWARD SW MN AND
THE IOWA GREAT LAKES... ESPECIALLY AS SNOW CONTINUES IN THOSE AREA
INTO MID MORNING. /CHAPMAN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR IAZ001>003-
012>014-020>022-031-032.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR MNZ071-072-
080-081-089-090-097-098.
NE...WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR NEZ013-014.
SD...WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR SDZ056-062-
066-067-069>071.
WINTER WEATHER ADVISORY UNTIL 4 AM CST MONDAY FOR SDZ038-050-
052-053-057>060-063>065-068.
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR SDZ039-040-
054-055-061.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 AM CST SUN JAN 22 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
230 AM CST SUN JAN 22 2012
FREEZING DRIZZLE IS THE FORECAST FOCUS TODAY/TONIGHT...WITH A NEED
FOR HEADLINES.
LATEST WATER VAPOR IMAGERY POINTED TO AN UPPER LEVEL TROUGH/SHORTWAVE
ENERGY MOVING EAST OUT OF THE DESERT SOUTHWEST. THE TROUGH WILL
TRACK OVER THE PLAINS...THEN CURVE NORTHEAST ACROSS THE GREAT
LAKES FOR TONIGHT/MON MORNING. THIS HAS BEEN A CONSISTENT SIGNAL IN
THE MODELS...ALTHOUGH THE TIMING AND POSITION OF THE SYSTEM HAS NOT.
HOWEVER...22.00Z RUNS STARTING TO SHOW MORE AGREEMENT WITH THE EC
AND GEM...DRIVING THE SYSTEM/S SFC LOW TO LOT BY 12Z SUN...WHILE THE
GFS IS SHIFTED A BIT FARTHER NORTH INTO SOUTHCENTRAL WI. THE NAM HAS
BEEN THE ODD MODEL OUT...BUT ITS RECENT RUN IS STARTING TO TREND
TOWARD THE SLOWER SOLUTIONS...ALTHOUGH STILL OVER NORTHERN WI BY 12Z
MON. GIVEN THE CONSISTENCY OF THE EC...WILL CONTINUE TO FAVOR THIS
SOLUTION...BLENDING IN THE GEM/GFS.
MAIN CONCERN WITH THIS SYSTEM IS THE POTENTIAL FOR FREEZING DRIZZLE.
NORTHWEST-SOUTHEAST X-SECTIONS AND BUFKIT SOUNDINGS CONTINUE TO SHOW
ONLY A LOW SATURATION IN PLACE INTO THIS EVENING...GENERALLY BELOW
850 MB. GOOD LOW LEVEL WARMING IN THE 925-850 MB LAYER ALONG WITH
ISENTROPIC UPGLIDE ALONG THE 275-290 K SFCS. RUC13 BUFKIT SOUNDINGS
SHOW A DECENT AMOUNT OF UPWARD OMEGA IN THE SATURATED LAYER THROUGH
THIS EVENING WHILE THE X-SECTIONS VIA THE GFS40 AND RUC13 POINT TO
SOME FRONTOGENETIC LIFT ALONG THE TOP OF THE SATURATED LAYER. ALL
MODELS SHOW SOME LIGHT QPF DEVELOPING BY AT LEAST THE AFTERNOON FOR
THE FORECAST AREA....PERSISTING INTO THE EVENING AND THEN INCREASING
TONIGHT AS THE SHORTWAVE TROUGH/SFC LOW MOVES IN. BEFORE THAT
THOUGH...THE EXPECTED LOW CLOUDS WILL LACK ANY ICE...THUS MAKING ANY
PCPN THE LIFT CAN SQUEEZE OUT OF THEM LIQUID...AND EITHER FREEZING
DRIZZLE OR DRIZZLE...SFC TEMP DEPENDENT. THAT SAID...WITH TEMPS
EXPECTED TO WARM INTO THE EARLY EVENING THANKS TO THE STRONG WARM
AIR ADVECTIVE SIGNAL...GROUND TEMPS WILL LIKELY STILL STAY BELOW
FREEZING DUE TO THE SEVERAL DAYS OF COLD CONDITIONS. SO...FREEZING
COULD STILL RESULT ON UNTREATED ROADS AND OTHER EXPOSED SFCS EVEN IF
THE AIR TEMP RISES ABOVE FREEZING.
WITH ALL THIS IN MIND...FEEL THE THREAT FOR AREAS OF FREEZING
DRIZZLE IS HIGH ENOUGH FOR A FREEZING RAIN ADVISORY TODAY INTO THIS
EVENING. SOUNDINGS AND X-SECTIONS DON/T REALLY DISCRIMINATE TOO MUCH
BETWEEN WHERE THE CHANCES WOULD BE BEST...SO WILL GO WITH THE ENTIRE
FORECAST AREA. THE AFTERNOON INTO EARLY EVENING WOULD APPEAR TO BE
THE MAIN THREAT TIME...BUT CAN/T RULE OUT PERIODS OF FREEZING
DRIZZLE THIS MORNING...SO WILL START IT EARLY.
THE SATURATION DEEPENS OVERNIGHT ENOUGH THAT ICE WOULD BE INTRODUCED
INTO THE CLOUD...AND SNOW BECOMES THE PCPN TYPE. THIS CORRESPONDS
WITH THE APPROACH OF THE UPPER LEVEL TROUGH/SFC LOW...AND BETTER
UPPER LEVEL FORCING. QPF INCREASES IN THE MODELS AS A RESULT...AND
SOME MINOR SNOW ACCUMULATIONS ARE PROBABLE. WHILE ITS BELIEVED THE
EC HAS THE BEST HANDLE ON THIS SYSTEM AT THIS TIME...ITS DEFORMATION
PCPN REGION LIES ON TOP OF ITS SFC LOW. MEANWHILE THE GFS AND GEM IS
DISPLACED A BIT MORE NORTH-WEST OF THE LOW TRACK...AND SEEMS MORE
REASONABLE. WILL TREND THE SNOW CHANCES THIS WAY OVERNIGHT. WILL GO
WITH 1 TO 3 INCHES OF SNOW ACCUMULATION...WITH THE HIGHER AMOUNTS
MORE LIKELY NORTH OF I-94.
SNOW WILL GRADUALLY SHIFT NORTHEAST AS THE LOW PRESSURE SYSTEM
SHIFTS INTO SOUTHEAST CANADA. IT WILL BE A WINDY DAY WITH AN
INCREASING SFC PRESSURE GRADIENT POST THE LOW. IN ADDITION...COLD
AIR ADVECTION WILL RESULT IN STEADY OF SLOWLY FALLING TEMPERATURES.
MONDAY/S HIGH WILL LIKELY BE DURING THE EARLY MORNING HOURS.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
230 AM CST SUN JAN 22 2012
FAIRLY ACTIVE NEARLY ZONAL UPPER LEVEL FLOW WILL PERSIST INTO THE
UPCOMING WEEKEND...SPINNING SEVERAL SHORTWAVE TROUGHS ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY. HOWEVER...BOTH THE GFS AND ECMWF
KEEP THE BULK OF ANY ASSOCIATED PCPN ACROSS NORTHERN PORTIONS OF THE
REGION. SO OVERALL...IT LOOKS FAIRLY DRY THROUGH THE PERIOD...WITH
THE BETTER...ALBEIT SMALL SNOW CHANCES...ACROSS THE NORTH.
TEMPERATURES SHOULD BE AT OR ABOVE THE SEASONABLE NORMALS.
&&
.AVIATION...TONIGHT AND MONDAY
1135 AM CST SUN JAN 22 2012
A STRONG AND MOIST SFC TO MID LEVEL LOW WILL LIFT NORTHEAST TOWARD/
ACROSS THE WESTERN GREAT LAKES REGION TONIGHT/MON. SFC-850MB
MOISTURE...LOW CLOUDS/BR AND PATCHY -FZDZ WITH MAINLY IFR CIGS/VSBYS
HAVE ALREADY SPREAD ACROSS THE TAF SITES. THESE CONDITIONS WILL
CONTINUE THRU THIS EVENING AS INCREASING MOISTURE CONTINUES TO BE
PUSHED NORTH INTO THE AREA. THE MID/UPPER LEVEL TROUGH AXIS WILL
PASS AFTER MIDNIGHT...WITH BROAD/DEEP LIFT COOLING THE COLUMN AND
CHANGING THE PRECIP TO SNOW. MAINLY IFR CIGS/VSBYS IN SNOW/BR WILL
CONTINUE AT THE TAF SITES THRU MON MORNING. FCST MODELS DIFFER ON
THE DETAILS/AMOUNTS BUT APPEARS SOME ACCUMULATING SNOW WILL OCCUR AT
THE TAF SITES IN THE 09-18Z TIME-FRAME...IMPACTING RUNWAYS AND
AIRPORT OPS. WINDS WILL INCREASE FROM THE NORTHWEST AS WELL MON
MORNING AS THE LOW CONTINUES TO DEEPEN AND LIFT NORTH ACROSS EASTERN
WI...CREATING SOME BLOWING/DRIFTING SNOW AT SITES LIKE KRST. THE LOW
WILL LIFT INTO THE MI U.P. MON AFTERNOON...WITH THE SNOW DIMINISHING
AND VSBYS IMPROVING TO MVFR THRU MON AFTERNOON. WITH ABUNDANT
MOISTURE WRAPPED AROUND THE LOW...IFR CIGS LOOK TO PERSIST INTO MON
NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 AM CST SUN JAN 22 2012
WI...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR WIZ017-029-032>034-041>044-053>055-061.
MN...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR MNZ079-086>088-094>096.
IA...FREEZING RAIN ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....RRS