Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/22/13
SEE THE FORECAST DISCUSSION BELOW FOR ADDITIONAL DETAILS
CONCERNING THE SYNOPSIS OF THIS SYSTEM.
&&
.SHORT TERM /MIDNIGHT THROUGH 6 PM TUESDAY/...
AN ELONGATED DISTURBANCE THRU THE LONGWAVE BAROCLINIC FLOW SLIDING
EAST WILL CAPTURE WARMER SOUTHERLY WESTERN ATLANTIC FETCH INVOKING
THE DEVELOPMENT OF A SFC LOW OFF THE S COAST OF LONG ISLAND. AS THIS
LOW AMPLIFIES TO THE EAST AND OUT TO SEA...A NEARLY STATIONARY
CONVERGENT BOUNDARY ELONGATES EAST...MEETING UP WITH A WEAK LOW PRES
CENTER OVER THE GREAT LAKES REGION.
THE SYNOPTIC SETUP HAS CHARACTERISTICS OF A NORLUN TROUGH IN WHERE
AN UNSTABLE ENVIRONMENT IS PRESENT IN A REGION OF FOCUS ALONG A
NEARLY STATIONARY CONVERGENT BOUNDARY AND SIGNIFICANT MOISTURE LIFT
TO ALLOW FOR PERSISTENT SNOW SQUALLS OVER A GIVEN AREA. SUCH EVENTS
HAVE RESULTED IN SNOW SQUALLS PRODUCING 2 TO 4 INCH SNOWFALL RATES
AN HOUR!
GOING CLOSER TO THE GFS AND WRF-NMM /WHILE WATCHING THE LATEST RAP
GUIDANCE WHICH HAS BEEN WONKY THE PAST COUPLE OF MODEL RUNS/ SEVERAL
FACTORS ARE OBSERVED: WITH THE AFOREMENTIONED SHORTWAVE...
POSITIVE VORTICITY ADVECTION IS PREVALENT AND COLOCATED IN
PROXIMITY OF THE LEFT-EXIT REGION OF AN UPPER LEVEL JET. THIS
ALLOWS FOR DEEP LAYER ASCENT WITHIN FAVORABLE SNOW GROWTH REGIONS
/-12 TO -18C/ ON THE ORDER OF 25 TO 50 UBAR/S! THIS ACTIVITY
FOCUSES ALONG A NW-SE INVERTED TROUGH SETUP /NORLUN/ SOMEWHERE
BETWEEN ESSEX COUNTY MA UP TO PORTLAND ME...IMPACTING THE EASTERN
HALF OF THE CAPE AS WELL... FOR AT LEAST A 6-HR PERIOD WHERE THE
H85 FLOW IS MODELED TO BE PARALLEL TO THE TROUGH. AN ONSHORE MOIST
FLOW /MAINLY N OF THE AFOREMENTIONED TROUGH/ COUPLED WITH COLD AIR
ADVECTION ALOFT MAKES FOR A VERY /CONDITIONALLY/ UNSTABLE LAPSE
RATE PROFILE FROM THE SFC UP TO AROUND H8! TOTAL- TOTALS VALUES
AROUND 50 COLOCATED WITH THE ANTICIPATED TROUGH SETUP /CANT RULE
OUT THE POSSIBILITY OF THUNDERSNOW ALONG AND N OF THE TROUGH/.
ALL THESE FACTORS COMBINED...THERE IS GROWING CONFIDENCE FOR THE
EXPECTATION FOR A TRAINING OF SNOW SQUALLS CONTINUALLY OVER A
PARTICULAR AREA ALONG THE E COAST OF NEW ENGLAND...CENTERED AROUND
COASTAL NEW HAMPSHIRE...AND WITH THE FLUFF FACTOR /AROUND 15:1 IN
THIS CASE/ OF THE SNOW ANTICIPATED...AMOUNTS UP TO A FOOT ARE NOT
OUT OF THE QUESTION.
BUT THE MOST IMPORTANT QUESTION IS WHERE EXACTLY THIS WILL SETUP
WHICH REMAINS VERY UNCERTAIN...KEEPING IN MIND THAT THIS BANDING IS
TYPICALLY 5-10 MILES IN WIDTH /VERY LOCALIZED/ AND THERE IS STILL
PLAUSIBILITY THAT ACTIVITY COULD REMAIN OFFSHORE.
FOR THE FORECAST...
LATE TONIGHT INTO TUESDAY MORNING...THE AXIS OF HEAVIEST SNOW PIVOTS
AROUND THE DEVELOPING LOW S AND E OF NEW ENGLAND. THE INVERTED
TROUGH /NORLUN/ SETUP BEGINS RESULTING IN THE HEAVIEST SNOWFALLS
ALONG THE IMMEDIATE COAST OF E NEW ENGLAND...PARTICULARLY ESSEX
COUNTY AND THE EASTERN HALF OF CAPE COD. WINTER STORM WARNINGS HAVE
BEEN ISSUED WITH THE EXPECTATION OF 6 TO 10 INCHES ENDING TUESDAY
MIDDAY.
INTO TUESDAY...ACTIVITY WILL TAPER OFF AS STRONG W/NW WINDS BUILD
INTO THE REGION. LAPSE RATES WILL REMAIN STEEP FROM THE NIGHT
PREVIOUS RESULTING IN THE MIX-DOWN OF GUSTS ACROSS THE INTERIOR
AROUND 30 MPH...WITH 45 MPH GUSTS AROUND THE CAPE AND ISLANDS. HAVE
ISSUED A WIND ADVISORY ACCORDINGLY...GALE WARNINGS OVER THE WATERS.
WITH THE PRIOR LIGHT SNOWFALL...STRONG W/NW WINDS WILL RESULT IN THE
BLOWING AND DRIFTING OF SNOW. QUITE PLAUSIBLE THE DRIFTING OF SNOW
WILL ALLOW FOR POOR VISIBILITIES AT TIMES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* BITTERLY COLD TEMPERATURES EXPECTED THROUGH THURSDAY
* COASTAL LOW PRESSURE BRINGS ANOTHER ROUND OF ACCUMULATING SNOWS
* REINFORCING COLD AIR RETURNS FOR THE WEEKEND
* TEMPERATURES SLOWLY MODERATE EARLY NEXT WEEK
MODEL DISCUSSION AND PREFERENCES...
MEDIUM RANGE MODEL SUITE IN GOOD AGREEMENT WITH MEAN LONG WAVE
TROUGH IN PLACE ALONG EASTERN SEABOARD THROUGH THURSDAY. THEY THEN
START TO DIVERGE LATE THIS WEEK WITH MODELS TRYING TO BREAK DOWN THE
LONG WAVE THROUGH...WHILE SURFACE LOW PRESSURE MOVES OUT OF THE OHIO
VALLEY TOWARD THE EAST COAST. 00Z ECMWF AND 12Z GGEM APPEAR TO BE IN
PRETTY GOOD AGREEMENT...WHILE THE 12Z GFS LAGS BACK. IN GENERAL...
THOUGH...ALL APPEAR TO KEEP THIS LOW S OF THE REGION AS ONE WOULD
EXPECT WITH SUCH A COLD AIRMASS ACROSS EASTERN CANADA. MODELS HAVE
BEEN SIGNALING THIS FEATURE SINCE LATE LAST WEEK...SO HAVE MODERATE
CONFIDENCE /AT LEAST/ FOR POTENTIAL ACCUMULATING SNOWS. THIS SYSTEM
REINFORCES EAST COAST LONG WAVE TROUGHING...SO EXPECT ANOTHER SHOT
OF COLD AIR INTO THIS WEEKEND.
OVERALL...USED A GENERAL BLEND OF THE GFS AND ECMWF...AS SUGGESTED
BY HPC. ALSO USED HPC AND PREVIOUS FORECAST FOR TEMPS TO KEEP
CONTINUITY...KEEPING READINGS ON THE VERY COLD SIDE FOR THE MOST
PART.
DETAILS...
TUESDAY NIGHT...HIGH PRES STARTS TO BUILD SE OUT OF CENTRAL CANADA
WITH HEART OF ARCTIC AIR CROSSING THE NORTHEAST. GFS AND ECMWF BOTH
AGREE H85 TEMPS WILL DROP TO BETWEEN -18C AND -25C WITH W-NW FLOW IN
PLACE. THIS WIND DIRECTION NOT A GOOD TRAJECTORY FOR OCEAN EFFECT
SNOWS ACROSS CAPE COD AND THE ISLANDS...BUT CAN NOT RULE OUT ISOLD
SNOW SHOWERS DEVELOPING ACROSS CAPE COD BAY OR NANTUCKET SOUND AND
POSSIBLY HITTING THE OUTER CAPE AND NANTUCKET.
WINDS WILL BE DIMINISHING OVERNIGHT...THOUGH WILL REMAIN AROUND 10-
15 MPH ALONG THE IMMEDIATE COAST. BIG QUESTION WILL BE WHETHER WIND
CHILL HEADLINES WILL BE NEEDED. EXPECT LOWS TO FALL BACK TO THE
SINGLE DIGITS FOR MOST AREAS...EXCEPT BETWEEN 10 AND 15 ALONG THE
IMMEDIATE COAST...OUTER CAPE COD AND THE ISLANDS.
WEDNESDAY...LARGE HIGH PRES BUILDS OUT OF ONTARIO TO THE EASTERN
SEABOARD. WITH COLD CORE OF AIR OVER REGION...WILL STILL SEE GOOD
MIXING IN PLACE...SO W-NW WINDS WILL PICK UP DURING THE DAY. IT WILL
BE FRIGID...HOWEVER...WITH HIGHS ONLY IN THE TEENS...EXCEPT THE
UPPER TEENS TO MID 20S ALONG THE IMMEDIATE COAST. SOME LOCALES
ACROSS THE HIGHER INLAND TERRAIN MAY NOT EVEN CRACK 10 DEGREES.
AGAIN...MAY NEED WIND CHILL HEADLINES FOR SOME INLAND LOCATIONS...
THOUGH WINDS WILL DROP OFF DURING THE DAY AS THE CENTER OF THE HIGH
APPROACHES.
FOR WED NIGHT...WINDS WILL BE LIGHTER THOUGH NOT CALM...BUT THE COLD
CORE IS STILL ACROSS THE REGION SO EXPECT LOWS TO FALL BACK TO BELOW
ZERO ACROSS THE GOOD PORTION OF INLAND AREAS AND THE SINGLE DIGITS
AS FAR S AS THE MID CAPE AND MARTHAS VINEYARD...HOLDING IN THE TEENS
ON THE OUTER CAPE...NANTUCKET AND BLOCK ISLAND.
THURSDAY...SURFACE HIGH WILL CROSS THE REGION LATE THU/THU NIGHT...
KEEPING COLD TEMPS BUT DRY CONDITIONS IN PLACE. WILL START TO SEE
CLOUDS INCREASE THU NIGHT AS NEXT SYSTEM STARTS TO APPROACH.
FRIDAY...POTENT DIGGING H5 SHORT WAVE DIVES INTO THE MEAN TROUGH
POSITION ALONG THE EASTERN SEABOARD AS SURFACE RIDGE AXIS MOVES
OFFSHORE. ALL MEDIUM RANGE MODELS BRING LOW PRES OUT OF THE OHIO
VALLEY TOWARD THE NJ COAST. APPEARS THIS LOW WILL MOVE OFF THE NJ
COAST...REMAINING S OF NEW ENGLAND LATE FRI/FRI NIGHT. WITH SUCH
COLD AIR IN PLACE... NO QUESTION THE PTYPE WILL BE SNOW BUT THE
QUESTION IS...HOW MUCH. LATEST QPF VALUES ARE A BIT HIGHER THAN
PREVIOUS FORECAST AND...WITH HIGH SNOW TO RAIN RATIOS EXPECTED...
MAY SEE A LOW TO MODERATE EVENT. SOMETHING TO KEEP A CLOSE EYE ON.
WILL CONTINUE TO MENTION MODERATE CONFIDENCE IN THE HAZARDOUS
WEATHER OUTLOOK.
SATURDAY...AS LOW PRES MOVES S OF NOVA SCOTIA...LEFTOVER SNOW WILL
FALL ACROSS E MA...LIKELY OCEAN ENHANCED ACROSS CAPE COD AND THE
ISLANDS AS WINDS TURN TO THE N. LARGE HIGH PRES BUILDS E...EXTENDING
FROM CENTRAL CANADA TO THE GULF COAST. EXPECT ANOTHER SHOT OF COLD
AIR...THOUGH NOT AS COLD AS MID WEEK....ON ORDER OF -10C TO -20C AT
H85. LOWS SAT NIGHT WILL DROP TO THE SINGLE DIGITS FOR MOST
AREAS...AND THE LOWER-MID TEENS ALONG THE IMMEDIATE COAST. SCT OCEAN
EFFECT SNOW SHOWERS ACROSS CAPE COD AND THE ISLANDS WITH CONTINUED N
WINDS INTO SAT NIGHT.
SUNDAY-MONDAY...ANOTHER LARGE HIGH BUILDS TO THE EASTERN SEABOARD
SUNDAY WITH ANOTHER COLD...DRY DAY THOUGH WINDS DIMINISHING. AS
RIDGE AXIS MOVES ACROSS NEW ENGLAND TO THE WESTERN ATLC ON MONDAY...
MAY SEE TEMPS START TO MODERATE.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
INTO LATE TUESDAY /0Z WEDNESDAY/...MODERATE CONFIDENCE.
TONIGHT...MAINLY MVFR-IFR CIGS/VSBYS IN -SN AND PATCHY
FOG...EXPECTED TO LOWER TO IFR-LIFR. MAY SEE POCKETS OF VLIFR
ACROSS E MA COAST...CAPE ANN AND CAPE COD AFTER 06Z. LIGHT/VRBL
WINDS BECOMING E-SE THEN NE OVERNIGHT...GENERALLY LESS THAN 10 KT.
EXPECT LIGHT AREA OF SNOW TO SHIFT E OVERNIGHT...THEN START TO
FOCUS INTO BANDS OF LOCALLY HEAVY SNOW TO THE EASTERN HALF OF NEW
ENGLAND...WHICH CAN BE ON THE ORDER OF 5 TO 10 MILES IN WIDTH.
DETAILED SPECIFICS REMAIN UNCERTAIN...AND THUS HAVE GONE WITH A
CONSERVATIVE FORECAST IN PREVAILING LOW IFR. WHILE THE BANDS OF
HEAVY SNOW MAY BE UNCERTAIN...HAVE CONFIDENCE THAT A BREADTH OF
SNOW SHOULD BE ANTICIPATED.
AM ASSURED THAT BEGINNING AROUND MIDNIGHT INTO THE MORNING HOURS
TUESDAY THAT TERMINALS WITHIN RI...E MA...AND S NH WILL
SPORATICALLY SEE HEAVY SNOW AT TIMES WITH 1/2 TO 1/4 SM +SN AND
VV002. EXACT HOUR-BY-HOUR SPECIFICS REMAIN UNCERTAIN.
WINDS WILL BE VARIABLE DURING THE TRANSITION OF THE LOW INTO
TUESDAY MORNING. WILL SEE INCREASING W-NW FLOW WITH GUSTS UP TO
40 KTS PSBL /ESPECIALLY FOR TERMINALS CLOSER TO SHORE/ AROUND OR
AFTER SUNRISE TUE. CIGS AND VSBYS WILL QUICKLY IMPROVE WITH HIGHER
W-NW FLOW.
KBOS TAF...AT THIS TIME...THE PERIOD OF FAVORABLE BANDING EXTENDS
BETWEEN 05Z-13Z TUESDAY. IT IS DURING THIS TIME THAT CONDITIONS AT
THE TERMINAL MAY BECOME VLIFR.
KBDL TAF...EXPECT HEAVIER SNOW TO REMAIN E OF TERMINAL. -SN SHOULD
CONTINUE TO ABOUT MIDNIGHT BUT CIGS WILL REMAIN MAINLY MVFR-IFR
THROUGH 06Z-08Z. CIGS SHOULD IMPROVE BY AROUND 12Z.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
TUESDAY NIGHT-THURSDAY...GENERALLY VFR. OCEAN EFFECT SNOW SHOWERS
CONTINUE NEAR CAPE COD WITH LOCAL MVFR CIGS.
FRIDAY...VFR TO START WITH CIGS/VSBYS CONDITIONS LOWERING TO
MVFR-IFR IN DEVELOPING SNOW FRIDAY MORNING OVER THE CT
VALLEY...SHIFTING E DURING THE AFTERNOON.
FRIDAY NIGHT-SATURDAY...MAINLY MVFR-IFR FRI NIGHT...LOWEST
CONDITIONS ACROSS N CT/RI/E MA IN SNOW. PRECIP ENDS FROM W-E AS
SNOW SHOWERS SAT...BUT MAY LINGER AS OCEAN EFFECT SNOW SHOWERS
ACROSS CAPE COD AND NANTUCKET SAT NIGHT WITH AREAS MVFR-IFR
CONDITIONS.
&&
.MARINE...
INTO LATE TUESDAY...MODERATE CONFIDENCE.
GALE WARNINGS ARE IN EFFECT AS IT IS EXPECTED THAT AN AREA OF LOW
PRES MOVING S OF NEW ENGLAND WILL DEEPEN AS IT PROGRESSES EAST. AS
IT DOES SO...WILL SEE A STRONG W/NW FETCH WITH GUSTS UP TO 40 KTS
FOR THE TUESDAY TIMEFRAME. SEAS OF 8 TO 10 FEET WILL BE POSSIBLE
ACROSS THE OUTER WATERS.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
TUESDAY NIGHT...GALE FORCE NW WINDS WILL CONTINUE UP TO 9 FT ON
THE OUTER WATERS. LIGHT FREEZING SPRAY ALONG WITH OCEAN EFFECT
SNOW SHOWERS.
WEDNESDAY...NW WINDS WILL GUST UP TO 30 KNOTS ESPECIALLY ON THE
OUTER WATERS. CONTINUED FREEZING SPRAY AND OCEAN EFFECT SNOW
SHOWERS UNTIL WINDS DIMINISH ON THURSDAY. SEAS WILL BE SLOW TO
RESPOND BEFORE DROPPING BELOW SCA LATE THURSDAY.
THURSDAY...NW WINDS GUSTING TO 30 KT...BUT WILL DIMINISH AS THEY
START TO SHIFT TO SW THU NIGHT. SEAS REMAIN AOA 5 FT.
FRIDAY...LOW PRES WILL CROSS THE SOUTHERN WATERS LATE FRI/FRI
NIGHT. SNOW IS LIKELY WITH NE WIND GUSTING UP TO 25 KT...MAINLY ON
THE EASTERN WATERS. VSBY LOWERING ON SNOW.
SATURDAY...WIND SHIFTS TO N AND GUSTS UP TO GALE FORCE MAINLY OVER
THE EASTERN WATERS. SEAS BUILD UP TO 8 FT. OCEAN EFFECT SNOW
SHOWERS AND FREEZING SPRAY ARE LIKELY.
&&
.CLIMATE...
BOS LOW MIN LOW MAX
JAN 22 -3F 1888 13F 1888
JAN 23 -6F 1882 13F 1882
JAN 24 -13F 1882 8F 1907
PVD LOW MIN LOW MAX
JAN 22 -10F 1976 15F 2000
JAN 23 -13F 1976 10F 1976
JAN 24 -9F 1907 9F 1907
BDL LOW MIN LOW MAX
JAN 22 -26F 1961 13F 2000
JAN 23 -19F 1961 7F 1976
JAN 24 -19F 1961 9F 1907
ORH LOW MIN LOW MAX
JAN 22 -10F 1976 9F 2000
JAN 23 -13F 1976 7F 1976
JAN 24 -14F 1948 4F 1907
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR CTZ004.
MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MAZ004-005-
012>021-023-024-026.
WINTER STORM WARNING UNTIL 1 PM EST TUESDAY FOR MAZ006-007-022.
NH...WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR NHZ012-015.
RI...WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR RIZ001>008.
MARINE...GALE WARNING FROM 4 AM TO 3 PM EST TUESDAY FOR ANZ232>235-237.
SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST TUESDAY FOR ANZ230.
GALE WARNING FROM 7 AM TO 3 PM EST TUESDAY FOR ANZ231-251.
GALE WARNING FROM 4 AM TO 1 PM EST TUESDAY FOR ANZ236.
GALE WARNING FROM 7 AM TO 7 PM EST TUESDAY FOR ANZ250-254.
GALE WARNING FROM 4 AM TO 7 PM EST TUESDAY FOR ANZ255-256.
&&
$$
SYNOPSIS...SIPPRELL/EVT
NEAR TERM...DOODY/SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...EVT
AVIATION...SIPPRELL/EVT
MARINE...SIPPRELL/EVT
CLIMATE...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
357 AM EST SUN JAN 20 2013
.DISCUSSION...
CURRENTLY...
HI PRES RIDGE OVR THE DEEP SOUTH HAS WEAKENED CONSIDERABLY OVER THE
PAST 24HRS. ERLY FLOW ACRS CENTRAL FL HAS DIMINISHED AS A RESULT. AN
H100-H85 TROF EXTENDS FROM THE NRN BAHAMAS TO THE SE GOMEX. THE USAF
CAPE PROFILER AND THE KTBW VAD WIND PROFILE CONTINUE TO HOLD 15-20KT
ENE WINDS THRU 4KFT. THIS IS LIKELY DUE TO THE INTERACTION BTWN THE
RIDGE AND THE TROF AS VAD WINDS AT KJAX/KMFL THRU 4KFT DIMINISH AOB
10KTS. HIGH REGIONAL MOISTURE THRU THE H100-H85 LYR PER SATELLITE
IMAGERY AND LATEST RAP ANALYSIS...MEAN RH VALUES BTWN 75-95PCT. THE
00Z KMFL/KTBW SOUNDINGS REMAIN SATURATED THRU THE H100-H80 LYR WITH
PWAT VALUES BTWN 1.0"-1.2"...UP FROM 0.8" ON THE 19/00Z RUN. A SHARP
SUBSIDENCE INVERSION REMAINS ABV H80 WITH VERY DRY AIR ALOFT. RADAR
SHOWS AREAS OF -RA MVG ONSHORE S OF CAPE CANAVERAL. PATCHY DENSE FOG
NOTED ALONG THE TREASURE COAST.
TODAY-TONIGHT...
MCLDY SKIES TO CONTINUE AS THE LOW LVL MOISTURE POOLS WITHIN THE
TROF WHILE REMAINING TRAPPED BELOW THE SUBSIDENCE INVERSION. STEADY
STATE E/NE FLOW THRU THE H100-H85 LYR WILL CONTINUE TO PUSH POCKETS
OF -RA ONSHORE...QPF BTWN 0.10"-0.25" S OF SEBASTIAN INLET...AOB
0.10" ELSEWHERE. FOR TODAY...WILL GO WITH 30 POPS ROUGHLY S OF LINE
FROM KISSIMMEE TO TITUSVILLE...20 POPS TO THE N. MAX TEMPS SIMILAR
TO SAT...GENERALLY L/M70S THOUGH AREAS AROUND LAKE OKEECHOBEE
COULD PUSH INTO THE U70S.
H100-H85 LYR WILL REMAIN SATURATED OVERNIGHT AS A CANADIAN HI PRES
RIDGE PUSHES OUT OF ALBERTA AND ABSORBS THE WEAK RIDGE OVER THE DEEP
SOUTH. THE NE FLOW WILL DIMINISH AS A RESULT...WHICH WILL MAKE IT
MORE DIFFICULT FOR SHRAS TO PUSH ONSHORE...LET ALONE INTO THE
INTERIOR. WILL KEEP SMALL POPS IN FOR THE SPACE/TREASURE COASTS AS
WELL AS OKEECHOBEE AND SRN OSCEOLA COUNTIES...BLO MENTIONABLE POPS
ELSEWHERE. DESPITE BLANKETING CLOUD COVER...THE DIMINISHED ONSHORE
FLOW SHOULD ALLOW MIN TEMPS TO COOL L/M50S ALONG AND N OF I-4 AND
M/U50S TO THE S...IMMEDIATE SPACE/TREASURE COASTS WILL HOLD IN THE
L/M60S.
MON-TUE...00Z GFS AND ECMWF MODELS BOTH SHOW MOISTURE LINGERING A
BIT LONGER AND A SLIGHT DELAY IN COOLER/DRIER AIRMASS
OVERSPREADING THE AREA. AS A RESULT...HAVE EXPANDED LOW RAIN
CHANCES FOR MONDAY TO ENCOMPASS MOST OF EC FL EXCEPT FAR NORTH
LAKE/VOLUSIA. FOCUSED RAIN CHANCES (30 POP) SOUTH OF THE CAPE NEAR
THE COAST. FORECAST MODEL SOUNDINGS SHOW CONTINUED CONSIDERABLE
STRATOCUMULUS CLOUDS MONDAY WITH INCREASING CIRRUS SHIELD FROM
RIGHT ENTRANCE REGION OF VERY STRONG (130 KT) UPPER JET.
THEN HIGH PRESSURE BUILDING SE FROM THE NORTHERN PLAINS WILL BRING
A SLIGHTLY COOLER BUT MUCH DRIER AIRMASS INTO THE AREA DURING
TUESDAY. THIS WILL SUPPRESS RAIN CHANCES TO THE FAR SOUTH...MARTIN
COAST. MAX TEMPS LOOK ONLY 3-5 DEGREES COOLER WITH INCREASING
SUNSHINE AS CIRRUS THINS AND NOTICEABLY LOWER DEWPOINTS. LOWS TUE
NIGHT/WED MORNING MAY REACH AS LOW AS THE UPPER 30S ACROSS FAR
NORTHERN LAKE AND NW VOLUSIA COUNTIES WITH WIDESPREAD UPPER
40S/LOWER 50S ELSEWHERE.
WED-SAT...COOL AND DRY CONDITIONS EXPECTED WED-THU AS HIGH
PRESSURE CENTER SHIFTS EAST ACROSS NORTH FL. TEMPERATURES FORECAST
TO BE AT OR SLIGHTLY BELOW NORMAL WEDNESDAY AND WED NIGHT BUT NO
FREEZING TEMPS ARE EXPECTED. MAX TEMPS BEGIN TO REBOUND THU...VERY
CLOSE TO SEASONAL NORMS IN THE LOWER TO MID 70S. HIGH PRESSURE
PUSHES OFFSHORE THU NIGHT SETTING UP A WARMER FRIDAY WITH SOUTHERLY
FLOW...A FAIR AMOUNT OF SUN AND MAX TEMPS IN THE MID TO UPPER 70S.
THE 00Z ECMWF PULLS A SLUG OF DEEP MOISTURE NORTHWARD ACROSS THE
FL PENINSULA FRI AND GENERATES A LARGE AREA OF RAINFALL AHEAD OF
THE NEXT COLD FRONT. BUT HAVE LEANED TOWARD THE 00Z GFS IN
KEEPING FRI RAIN-FREE. BOTH GFS AND ECMWF MODELS SWEEP THE COLD
FRONT THROUGH THE AREA EARLY SAT. PREFER THE GFS SOLUTION SHOWING
A THIN BAND OF FAST MOVING SHOWERS ASSOCD WITH THE FRONT WITH
SOME GUSTY WINDS. BOTH MODELS SHOW VEERING LOW LEVEL FLOW TO THE
W/SW AHEAD OF THE FRONT WHICH...AMONG OTHER THINGS...LOOKS TO
KEEP THE SEVERE WEATHER THREAT TO A MINIMUM.
&&
.AVIATION...
THRU 20/15Z...PREVAILING CIGS BTWN FL030-040...AREAS MVFR/LCL IFR
VSBYS/CIGS IN PATCHY FOG/STRATUS...-RA ALNG THE COAST S OF KTIX.
AFT 20/15Z...PREVAILING CIGS BTWN FL040-060...S OF KTIX-KISM SCT
MVFR SHRAS...N OF KTIX-KISM ISOLD MVFR SHRAS.
&&
.MARINE...
TODAY-TONIGHT...WEAK LOW LVL TROF EXTENDING FROM THE NRN BAHAMAS TO
THE SE GOMEX WILL INTERACT WITH A WEAK HI PRES RIDGE OVER THE DEEP
SOUTH TO MAINTAIN A GENTLE TO MODERATE NERLY BREEZE ACRS THE LCL
ATLC. THESE WINDS WILL PUSH A 3-4FT SWELL INTO THE E FL COAST...
KEEPING SEAS IN THE 4-6FT RANGE THRU LATE THIS EVNG. SWELL WILL
GRADUALLY DAMPEN OUT OVERNIGHT WITH SEAS FALLING TO 3-5FT BY
DAYBREAK MON.
BUOY009 MEASURING A DOMINANT PD ARND 7SEC. THIS IS MOST LIKELY A
REFLECTION OF THE INTERACTION BTWN THE GULF STREAM AND THE
PREVAILING NE BREEZE AS ALL OTHER BUOYS HAVE DOMINANT PDS AOA 10SEC.
AS SUCH...WILL ALLOW THE SCA TO EXPIRE BUT WILL KEEP A CAUTIONARY
STATEMENT FOR THE GULF STREAM.
MON-THU...PRETTY FAVORABLE BOATING CONDITIONS MONDAY WITH LIGHT NE
WINDS AROUND 10 KNOTS AND A 3 FT NE SWELL. HIGH PRESSURE BUILDING
SE FROM THE UPPER PLAINS WILL INCREASE THE NORTHERLY GRAD WIND
15-20 KNOTS EARLY TUE THRU TUE NIGHT WITH BOATING CONDITIONS
BECOMING LESS FAVORABLE. SEAS WILL BUILD TO 5 FT BY LATE TUE AND
MAY SEE 6 FT IN THE GULF STREAM TUE NIGHT INTO EARLY WED SO WILL
LIKELY NEED AT LEAST A CAUTION HEADLINE. WINDS WILL DECREASE BY
THU ESP ACROSS NORTH/CENTRAL WATERS AS HIGH PRESSURE CENTER TRACKS
EAST ACROSS NORTH FL.
&&
.FIRE WEATHER...
NO LOW RH CONCERNS THROUGH MONDAY. COOLER AND MUCH DRIER AIR IS
FORECAST TO OVERSPREAD THE AREA TUE INTO WED AND PRODUCE MIN RH
VALUES BELOW 35 PERCENT EACH AFTN. N/NW WINDS DO NOT LOOK QUITE
AS STRONG NOW BEHIND THE FRONT TUE BUT THERE SHOULD BE SOME GUSTS
UP TO 20 MPH IN THE AFTN. LIGHTER WINDS WED AND THU WILL NOT
MODIFY THE DRY AIRMASS MUCH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 71 57 73 52 / 20 10 20 10
MCO 75 58 76 56 / 20 10 20 10
MLB 74 64 77 61 / 30 20 30 20
VRB 75 63 77 60 / 30 20 30 20
LEE 75 55 74 53 / 20 10 10 10
SFB 75 57 75 54 / 20 10 20 10
ORL 75 58 75 56 / 20 10 20 10
FPR 76 63 77 60 / 30 20 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....KELLY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
829 PM EST MON JAN 21 2013
.UPDATE/AVIATION...
MULTI BAND LK EFFECT CONTS UNABATED THIS EVENING IN RESPONSE TO
EXTREME LK INDUCED INSTABILITY. PRIMARY LIMITING FCTR TO ACCUMS
CONTS TO BE POOR MICROPHYSICAL THERMO ENVIRONMENT W/LL ASCENT
MAXIMUM CNTRD ARND -20C. THUS XPC FINE POWDER SMALL PLATE CRYSTAL
TYPE TO DOMINATE W/SUBSEQUENT ACCUMS SIGLY LIMITED. OTRWS HRRR/RUC
MODEL FCST TRENDS DOVETAIL IN NICELY W/OBSVD RADAR/SAT TRENDS THIS
EVENING W/GENERAL SLOW VEER AND SLOW SWD SUPPRESSION OF STRONGEST
INLAND PENETRATING CONVERGENT BAND. XPC UPTICK IN BAND EVOLUTION
OVERNIGHT W/BTR LK INDUCED SATURATION DVLPG WITHIN SHALLOW CLD
GROWTH LYR. IN FACT BASED ON RUC CROSS-SECTIONS DEEPENING UVM MAY
YIELD A PD OF LARGER SECTORED PLATE GROWTH TWD DAYBREAK TOMORROW.
HWVR AS IT STANDS NOW WILL LEAVE ADVISORY AREA AS IS BUT CONCEDE
SOME THREAT EXISTS SWD OF THE STATELINE ACRS ST. JOE...ELKHART AND
LAGRANGE TO GET IN ON SOME DECENT SNOW ACCUMULATION LT TONIGHT
THROUGH TUES. REGARDLESS PRIMARY OVERNIGHT GRID CHG SHIFTS HIGHEST
POPS ABT 20 MILES SWD OF AFTN FCST. REMAINDER OF NR TERM GRIDS
DEEMED ON TRACK AND LEFT UNCHGD.
PROLONGED PD OF IFR/LIFR CONDS AT KSBN W/ORGANIZING SNOWBANDS
OVERNIGHT...VFR AT KFWA.
&&
.SHORT TERM...THROUGH TUESDAY NIGHT.
LAKE EFFECT MACHINE HAS BEEN UNDERWAY ACROSS MUCH OF WESTERN LOWER
MICHIGAN INTO PORTIONS OF NORTHERN INDIANA TODAY. ONE BAND SET UP
FOR SEVERAL HOURS FROM BERRIEN INTO ST JOE COUNTIES IN MI BEFORE
UNDULATING ACROSS THE AREA. DESPITE OCCASIONAL RETURNS UPWARDS OF 30
DBZ THAT WOULD SUGGEST 1 TO 2 INCH PER HOUR OR MORE SNOW RATES
AMOUNTS THAT HAVE BEEN TRICKLING IN HAVE ONLY BEEN AN INCH OR LESS
WITH SOME ISOLATED HIGHER AMOUNTS. ROADS HAVE BEEN REPORTED SNOW
COVERED AND SLIPPERY ACROSS BERRIEN AND CASS COUNTIES WITH NO SIG
IMPACTS ACROSS THE REMAINDER OF THE LAKE EFFECT ADVISORY AREA.
HOWEVER...THE HEAVIER BANDS ARE STILL IMPACTING VSBYS...DOWN BELOW A
HALF MILE AT TIMES...WITH BLOWING SNOW. RADAR TRENDS SUGGEST A LULL
IN ACTIVITY MAY TRANSPIRE THIS EVENING AS WEAK SUBSIDENCE BEHIND THE
DEPARTING WAVE KEEPS BANDS RATHER DISORGANIZED. GIVEN IMPACTS
EXPECTED INTO THE EVENING AND LOWERING WIND CHILLS...WILL EXTEND
LAKE EFFECT SNOW ADVISORY FOR WESTERN 3 MI COUNTIES THROUGH 5 AM BUT
DROP BRANCH AND HILLSDALE. HI-RES MODELS INDICATE SNOW SHOWERS MAY
PICK UP ONCE AGAIN LATER THIS EVENING INTO THE OVERNIGHT HOURS AND
ESPECIALLY TUESDAY WITH ANOTHER SHOT OF MSTR AND INCREASED LIFT.
SFC-850 MB DELTA T`S REMAIN MORE THAN FAVORABLE WELL INTO THE 20S
BUT DGZ ONCE AGAIN WILL BE AT OR JUST ABOVE GROUND LEVEL...SETTING
UP A SIMILAR SCENARIO TO TODAY WITH LACK OF DENDRITIC GROWTH AND
RESULTANT LOW ACCUM POTENTIAL. SOME CHANGES MADE OVERNIGHT TO POPS
TO ALIGN BETTER WITH CURRENT MODEL OUTPUT BUT NO SIG CHANGES MADE TO
TUES/TUES NGT IN TERMS OF POPS/QPF/SNOWFALL.
IN TERMS OF TEMPS AND WIND CHILLS...TEMPS TODAY HAVE FLUCTUATED BY
SEVERAL DEGREES ACROSS THE AREA...WITH BRIEF RISES UNDER POCKETS OF
SUNSHINE FOLLOWED BY A QUICK DROP BACK WITH CLOUD COVER ARRIVAL.
UPSTREAM SIMILAR TRENDS ARE SEEN BUT MOST NOTABLE IS DECREASING
DEWPTS...WELL INTO THE NEGATIVE TEENS. THESE SHOULD HEAD TOWARDS THE
AREA TONIGHT. DESPITE LACK OF DECOUPLING TONIGHT OF WINDS...STRENGTH
OF CAA WILL STILL ALLOW FOR A DROP OFF IN TEMPS INTO THE 0 TO 5
DEGREE ABOVE RANGE. WOULD NOT BE SURPRISED TO SEE A SPOT OR 2 GO SUB
ZERO FOR A PERIOD. WIND CHILLS WILL STILL RANGE FROM -12 TO -18 IN
MANY AREAS EVEN CLOSER TO THE LAKE. AS A RESULT WIND CHILL ADVISORY
WILL CONTINUE WITH ONLY CHANGE BEING TO ADD BRANCH AND HILLSDALE
COUNTIES. ONLY MODEST INCREASE IN TEMPS EXPECTED ON TUESDAY WITH
HIGHS STRUGGLING INTO THE TEENS AND A QUICK DROP OFF BACK INTO THE
SINGLE DIGITS TUES NGT. WIND CHILLS COULD HEAD TOWARDS CRITERIA ONCE
AGAIN TUES NGT BUT WILL HOLD OFF ON ANY CHANGES/ADDITIONS TO THE
CURRENT HEADLINES.
&&
.LONG TERM.../WED-MON/
LONG WAVE TROF OVER ERN CANADA/U.S. WILL MAINTAIN NW FLOW ALOFT
ACROSS THE GRTLKS AT START OF THIS PERIOD. ARCTIC AIRMASS WILL
REMAIN IN PLACE WITH H85 TEMPS AROUND -20C WED MORNING. SHRTWV
ROTATING AROUND CLOSED LOW OVER SE CANADA WILL DROP SE INTO THE WRN
GRTLKS WED AND MAY PROVIDE SUFFICIENT FORCING TO CAUSE A FEW SNOW
SHOWERS BEYOND JUST LAKE EFFECT AREAS. AS THE SHRTWV MOVES SE ACROSS
THE GRTLKS WED NGT... WLY LOW LEVEL WINDS OVER SRN LM WILL VEER TO
NE. IN THE PROCESS A BRIEF LONG NLY FETCH MAY ENHANCE LAKE EFFECT
SNOW SHOWER ACTIVITY IN NW INDIANA... BUT PRBLY TOO SMALL A WINDOW
TO RESULT IN SGFNT ACCUMS...ESPECIALLY CONSIDERING WARMING ALOFT AND
LOWERING INVERSION OVERNIGHT.
CLOSED LOW OVER NERN PAC EXPECTED TO KICK OUT A SHRTWV WHICH WILL
BREAK DOWN WEST COAST RIDGE AND MOVE ACROSS PAC NW WED AND INTO THE
PLAINS THU. CONSIDERABLE SPREAD IN LATEST MODELS ON
TIMING/STRENGTH/TRACK OF THIS SYSTEM. ECMWF AND GFS OVER THE PAST
24HRS HAVE SLOWED EASTWARD MOVEMENT OF THE SHRTWV ACROSS THE COUNTRY
AND AS SUCH HAVE LOWERED POPS FOR THU. UPR TROF SHOULD RESULT IN TWO
SFC LOWS MOVG INTO THE PLAINS THU... WITH ONE MOVG SE FROM THE NRN
PLAINS AND THE OTHER MOVG NE FROM THE SRN PLAINS THROUGH FRI. SRN
LOW WILL HAVE MUCH MORE MOISTURE TO WORK WITH AND THUS GREATER
POTENTIAL TO PRODUCE BAND OF SGFNT SNOW IN OR CLOSE TO OUR CWA.
GIVEN RATHER LARGE MODEL DIFFERENCES ON TRACK OF SRN LOW...
CONSIDERABLE UNCERTAINTY REMAINS AS TO WHERE THIS WILL BE... BUT
APPEARS ATTM SRN PORTION OF OUR CWA OR POINTS FARTHER SOUTH HAVE
GREATEST POTENTIAL.
ANOTHER SURGE OF COLD AIR SHOULD FOLLOW THU NGT`S LOW INTO THE AREA
WITH BLO NORMAL TEMPS AND SOME LES FRI-SAT. SFC HIGH PASSING TO THE
EAST WITH MORE ZONAL FLOW ALOFT SHOULD RESULT IN A WARMING TREND
SUNDAY-MONDAY. MEDIUM RANGE MODELS INDICATE A WK SHRTWV MAY MOVE
THROUGH THE AREA IN THIS TIMEFRAME BUT GIVEN DISAGREEMENTS ON TIMING
WITH SUCH A WK FEATURE... OPTED TO LEAVE PRECIP CHANCES OUT
OF FCST FOR NOW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND CHILL ADVISORY FROM 8 PM EST /7 PM CST/ THIS EVENING TO 11
AM EST /10 AM CST/ TUESDAY FOR INZ003>009-012>018-020-
022>027-032>034.
MI...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM EST TUESDAY
FOR MIZ080-081.
LAKE EFFECT SNOW ADVISORY UNTIL 5 AM EST TUESDAY FOR MIZ077>079.
OH...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM EST TUESDAY
FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...FISHER
LONG TERM...JT
UPDATE/AVIATION...T
AREA FORECAST DISCUSSION
NWS GOODLAND KS
455 PM MST MON JAN 21 2013
.UPDATE...
ISSUED AT 449 PM MST MON JAN 21 2013
ALREADY SEEING STRATUS/MINOR FOG BEGINNING TO SHIFT TO THE WEST AT
MCK AND WITH LOW LEVEL FLOW SHIFTING TO THE EAST OVER THE NEXT FEW
HOURS EXPECT THIS TREND TO CONTINUE. HAVE SPED UP FOG DEVELOPMENT
IN FORECAST AS WELL AS INCREASED AREAL COVERAGE ACROSS NORTHERN
HALF OF CWA. A BIT TOO EARLY TO DETERMINE THE MAGNITUDE OF VISBY
RESTRICTION AS IT COULD BE MORE OF A LOW STRATUS VS FOG TYPE
SCENARIO SO FOR NOW WILL NOT ISSUE ANY KIND OF FOG ADVISORY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 159 PM MST MON JAN 21 2013
AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE AREA WERE
MOSTLY CLEAR. SOME LINGERING CLOUDS WERE STILL AROUND
NORTON...KANSAS BUT THESE CLOUDS CONTINUE ON A SLOW DISSIPATION
TREND. TEMPERATURES RANGED FROM THE LOW 30S NEAR MCCOOK NEBRASKA TO
THE LOW TO MID 50S IN PORTIONS OF EASTERN COLORADO. WINDS WERE LIGHT
AND VARIABLE ACROSS THE FORECAST AREA. A LEE TROUGH WAS PRESENT
ALONG THE FRONT RANGE IN CENTRAL COLORADO.
NO PRECIPITATION IS EXPECTED THROUGH TUESDAY. A RIDGE OF HIGH
PRESSURE WILL REMAIN IN PLACE ACROSS THE WESTERN UNITED
STATES...BLOCKING ANY WEATHER MAKING SYSTEMS FROM MOVING ACROSS THE
PLAINS. A COUPLE SHORTWAVES WILL ROTATE AROUND THE LARGE TROUGH OF
LOW PRESSURE TO THE EAST BUT ANY SNOW PRODUCED BY THESE WILL REMAIN
WELL TO THE EAST...ACROSS THE DAKOTAS...EASTERN NEBRASKA...IOWA AND
MINNESOTA.
THE MAIN FORECAST CONCERN FOR THE NEXT 24 HOURS WILL BE THE CHANCES
FOR FOG TONIGHT. GFS LAMP GUIDANCE CONTINUES TO SUGGEST THE CHANCE
FOR FOG TONIGHT WHILE THE SREF MODEL HAS BACKED OFF TO A DEGREE.
MODEL SOUNDINGS SHOW A STRONG INVERSION WITH SOME MOISTURE ADVECTING
BACK INTO NORTHEAST PORTIONS OF THE COUNTY WARNING AREA DUE TO
PERSISTENT EAST WINDS. HAVE CONTINUED THE MENTION OF PATCHY FOG BUT
THERE ARE CONCERNS THAT MORE LOW STRATUS WILL DEVELOP THAN FOG.
STRATUS AND FOG...IF ANY...WILL QUICKLY BURN OFF DURING THE LATE
MORNING HOURS...SIMILAR TO WHAT HAPPENED TODAY. THIS WILL LEAD TO
MOSTLY CLEAR SKIES THROUGHOUT THE DAY. 850 MB TEMPERATURES WARM UP
SEVERAL DEGREES FOR TOMORROW AFTERNOON. THERE WILL BE A LARGE
TEMPERATURE RANGE ACROSS THE AREA SINCE A COLD AIR MASS REMAINS JUST
EAST ACROSS THE CENTRAL PLAINS. HIGH TEMPERATURES WILL BE IN THE LOW
40S NEAR MCCOOK NEBRASKA AND HILL CITY KANSAS...WHILE HIGH TEMPS
WILL BE NEAR 60 ACROSS PORTIONS OF EAST COLORADO. WINDS WILL LIKELY
REMAIN LIGHT THROUGHOUT THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 100 PM MST MON JAN 21 2013
TUESDAY NIGHT-THURSDAY...UPPER RIDGE TO MOVE ACROSS THE AREA THROUGH
WEDNESDAY BEFORE A PACIFIC NORTHWEST TROUGH AND COLD FRONT MOVE INTO
THE AREA THURSDAY.
DISCREPANCIES SHOW UP IN THE TEMPERATURE FORECAST WEDNESDAY AND
THURSDAY. NAM AND MET GUIDANCE KEEP A BACKDOOR FRONT OUT OF THE AREA
WEDNESDAY WHILE GFS/ECMWF/UKMET PUSH IT THROUGH. WILL TREND TOWARD
THE MAJORITY WHICH WILL ALSO BE RATHER CLOSE TO CURRENT FORECAST OF
UPPER 40S TO LOW 60S (EAST TO WEST) WEDNESDAY. ON THURSDAY THE NAM
PUSHES THE PACIFIC NORTHWEST COLD FRONT COMPLETELY THROUGH THE AREA
WHILE THE GFS IS ABOUT 6 HOURS LATER. HAVE TRENDED TOWARD THE GFS
WHICH WILL RESULT IN LESSER WIND THEN EXPECTED THE PREVIOUS FEW DAYS
AND A BIT WARMER HIGHS THEN PREVIOUSLY FORECAST.
NO PRECIPITATION IS EXPECTED.
FRIDAY-MONDAY...UPPER RIDGE REBUILDS OVER THE AREA FROM THE WEST
FRIDAY AND SATURDAY WITH A LARGE SCALE TROUGH OVER THE AREA SUNDAY
AND MONDAY. TEMPERATURES WILL BE WARMEST OVER THE WEEKEND WITH
SLIGHTLY COOLER BUT STILL ABOVE NORMAL TEMPERATURES RETURNING
MONDAY. NO PRECIPITATION IS EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 440 PM MST MON JAN 21 2013
ANOTHER COMPLICATED SET OF TAFS WITH CONFLICTING SIGNALS FROM THE
VARIOUS SMALL SCALE MODEL OUTPUT. MODELS WITH THE EXCEPTION OF
THE RUC...WHICH DOING THE BEST AT THIS TIME...AND TO A LESSER
EXTENT THE HRRR AND ECMWF DO NOT HAVE THE FRONT THAT HAS SAGGED
OVER THE NORTHERN HALF OF THE AREA...FAR ENOUGH SOUTH AND WEST.
STRATUS NOT THAT FAR AWAY AND ALREADY COMING BACKING INTO KMCK AT
THIS TIME. SO WENT WITH A COMBINATION OF REALITY THEN LEANING
HEAVILY ON THE RUC/RAP AND TO LESSER EXTENT THE ECMWF.
SO HAVE BROUGHT KMCK INTO THE MVFR CATEGORY AND OCCASIONALLY
BRINGING IT DOWN INTO IFR. AT KMCK DID NOT GO DOWN AS FAR AS WHAT
THE MODEL IS INDICATING SINCE CONFIDENCE IS LOW BASED ON CURRENT
AND YESTERDAYS MODEL PERFORMANCE. IT IS POSSIBLE THAT PREVAILING
IFR AND EVEN LIFR WILL BE POSSIBLE THERE. AT KGLD I BRING MVFR
CONDITIONS IN DURING THE EVENING AND RETURN VFR AT 12Z.
HOWEVER...MODELS DISAGREE HOW FAR WEST TO BRING THE LOWEST
CONDITIONS AND IS POSSIBLE THAT IFR CONDITIONS COULD OCCUR AT KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...RRH
LONG TERM...99
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
448 PM MST MON JAN 21 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 159 PM MST MON JAN 21 2013
AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE AREA WERE
MOSTLY CLEAR. SOME LINGERING CLOUDS WERE STILL AROUND
NORTON...KANSAS BUT THESE CLOUDS CONTINUE ON A SLOW DISSIPATION
TREND. TEMPERATURES RANGED FROM THE LOW 30S NEAR MCCOOK NEBRASKA TO
THE LOW TO MID 50S IN PORTIONS OF EASTERN COLORADO. WINDS WERE LIGHT
AND VARIABLE ACROSS THE FORECAST AREA. A LEE TROUGH WAS PRESENT
ALONG THE FRONT RANGE IN CENTRAL COLORADO.
NO PRECIPITATION IS EXPECTED THROUGH TUESDAY. A RIDGE OF HIGH
PRESSURE WILL REMAIN IN PLACE ACROSS THE WESTERN UNITED
STATES...BLOCKING ANY WEATHER MAKING SYSTEMS FROM MOVING ACROSS THE
PLAINS. A COUPLE SHORTWAVES WILL ROTATE AROUND THE LARGE TROUGH OF
LOW PRESSURE TO THE EAST BUT ANY SNOW PRODUCED BY THESE WILL REMAIN
WELL TO THE EAST...ACROSS THE DAKOTAS...EASTERN NEBRASKA...IOWA AND
MINNESOTA.
THE MAIN FORECAST CONCERN FOR THE NEXT 24 HOURS WILL BE THE CHANCES
FOR FOG TONIGHT. GFS LAMP GUIDANCE CONTINUES TO SUGGEST THE CHANCE
FOR FOG TONIGHT WHILE THE SREF MODEL HAS BACKED OFF TO A DEGREE.
MODEL SOUNDINGS SHOW A STRONG INVERSION WITH SOME MOISTURE ADVECTING
BACK INTO NORTHEAST PORTIONS OF THE COUNTY WARNING AREA DUE TO
PERSISTENT EAST WINDS. HAVE CONTINUED THE MENTION OF PATCHY FOG BUT
THERE ARE CONCERNS THAT MORE LOW STRATUS WILL DEVELOP THAN FOG.
STRATUS AND FOG...IF ANY...WILL QUICKLY BURN OFF DURING THE LATE
MORNING HOURS...SIMILAR TO WHAT HAPPENED TODAY. THIS WILL LEAD TO
MOSTLY CLEAR SKIES THROUGHOUT THE DAY. 850 MB TEMPERATURES WARM UP
SEVERAL DEGREES FOR TOMORROW AFTERNOON. THERE WILL BE A LARGE
TEMPERATURE RANGE ACROSS THE AREA SINCE A COLD AIR MASS REMAINS JUST
EAST ACROSS THE CENTRAL PLAINS. HIGH TEMPERATURES WILL BE IN THE LOW
40S NEAR MCCOOK NEBRASKA AND HILL CITY KANSAS...WHILE HIGH TEMPS
WILL BE NEAR 60 ACROSS PORTIONS OF EAST COLORADO. WINDS WILL LIKELY
REMAIN LIGHT THROUGHOUT THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 100 PM MST MON JAN 21 2013
TUESDAY NIGHT-THURSDAY...UPPER RIDGE TO MOVE ACROSS THE AREA THROUGH
WEDNESDAY BEFORE A PACIFIC NORTHWEST TROUGH AND COLD FRONT MOVE INTO
THE AREA THURSDAY.
DISCREPANCIES SHOW UP IN THE TEMPERATURE FORECAST WEDNESDAY AND
THURSDAY. NAM AND MET GUIDANCE KEEP A BACKDOOR FRONT OUT OF THE AREA
WEDNESDAY WHILE GFS/ECMWF/UKMET PUSH IT THROUGH. WILL TREND TOWARD
THE MAJORITY WHICH WILL ALSO BE RATHER CLOSE TO CURRENT FORECAST OF
UPPER 40S TO LOW 60S (EAST TO WEST) WEDNESDAY. ON THURSDAY THE NAM
PUSHES THE PACIFIC NORTHWEST COLD FRONT COMPLETELY THROUGH THE AREA
WHILE THE GFS IS ABOUT 6 HOURS LATER. HAVE TRENDED TOWARD THE GFS
WHICH WILL RESULT IN LESSER WIND THEN EXPECTED THE PREVIOUS FEW DAYS
AND A BIT WARMER HIGHS THEN PREVIOUSLY FORECAST.
NO PRECIPITATION IS EXPECTED.
FRIDAY-MONDAY...UPPER RIDGE REBUILDS OVER THE AREA FROM THE WEST
FRIDAY AND SATURDAY WITH A LARGE SCALE TROUGH OVER THE AREA SUNDAY
AND MONDAY. TEMPERATURES WILL BE WARMEST OVER THE WEEKEND WITH
SLIGHTLY COOLER BUT STILL ABOVE NORMAL TEMPERATURES RETURNING
MONDAY. NO PRECIPITATION IS EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 440 PM MST MON JAN 21 2013
ANOTHER COMPLICATED SET OF TAFS WITH CONFLICTING SIGNALS FROM THE
VARIOUS SMALL SCALE MODEL OUTPUT. MODELS WITH THE EXCEPTION OF
THE RUC...WHICH DOING THE BEST AT THIS TIME...AND TO A LESSER
EXTENT THE HRRR AND ECMWF DO NOT HAVE THE FRONT THAT HAS SAGGED
OVER THE NORTHERN HALF OF THE AREA...FAR ENOUGH SOUTH AND WEST.
STRATUS NOT THAT FAR AWAY AND ALREADY COMING BACKING INTO KMCK AT
THIS TIME. SO WENT WITH A COMBINATION OF REALITY THEN LEANING
HEAVILY ON THE RUC/RAP AND TO LESSER EXTENT THE ECMWF.
SO HAVE BROUGHT KMCK INTO THE MVFR CATEGORY AND OCCASIONALLY
BRINGING IT DOWN INTO IFR. AT KMCK DID NOT GO DOWN AS FAR AS WHAT
THE MODEL IS INDICATING SINCE CONFIDENCE IS LOW BASED ON CURRENT
AND YESTERDAYS MODEL PERFORMANCE. IT IS POSSIBLE THAT PREVAILING
IFR AND EVEN LIFR WILL BE POSSIBLE THERE. AT KGLD I BRING MVFR
CONDITIONS IN DURING THE EVENING AND RETURN VFR AT 12Z.
HOWEVER...MODELS DISAGREE HOW FAR WEST TO BRING THE LOWEST
CONDITIONS AND IS POSSIBLE THAT IFR CONDITIONS COULD OCCUR AT KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...99
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS WICHITA KS
546 PM CST MON JAN 21 2013
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD.
A DRY NORTHWEST FLOW REGIME ALOFT WILL CONTINUE AS A SHALLOW POLAR
AIRMASS CONTINUES TO GRIP THE PLAINS. STRATOCU CIGS WITH THE MORE
FIRMLY ENTRENCHED COLD AIR IS EXPECTED TO REMAIN JUST NORTH AND
EAST OF THE AREA WITH THE SURFACE FLOW TAKING ON A GENERAL LIGHT
EASTERLY COMPONENT.
KED
&&
.PREV DISCUSSION... /ISSUED 320 PM CST MON JAN 21 2013/
DISCUSSION...
TODAY-WED:
COMPLEX SURFACE PATTERN WITH REALLY COLD AIR SLOWLY BACKDOORING
INTO FORECAST AREA...AND SOME RETURN FLOW DEVELOPING IN FAR
WESTERN SECTIONS. NOT A LOT OF CONFIDENCE IN ANY OF THE MODELS
ABILITY TO RESOLVE LOCATION OF COLDEST AIR AND RESULTANT LOW
CLOUDS. BEST GUESS IS FOR COLD AIR TO CONTINUE TO SAG AT LEAST
OVERNIGHT... POTENTIALLY LEAVING A SHARP BOUNDARY SOMEWHERE ACROSS
THE AREA ON TUE. ANTICIPATE ANY LOW CLOUDS EARLY IN THE MORNING
WILL BE ERODED FAIRLY QUICKLY AND WILL HAVE FAIR AMOUNT OF
MODIFICATION OF COLD AIR NEAR BOUNDARY. BEST GUESS FOR WED IS
LITTLE SURFACE FLOW... PROBABLY OUT OF THE EAST. THIS SHOULD
RECIRCULATE COOL AIR...SO NOT EXPECTING MUCH RECOVERY AT THIS TIME.
WED NIGHT-FRI:
RETURN FLOW BEGINS TO DEVELOP ON BOTH ECMWF/GFS...WITH BOTH
SHOWING 850MB MOISTURE WORKING NORTH...PRIMARY AFFECTING SOUTHERN
SECTIONS DURING THE PERIOD. REMAINS TO BE SEEN WHETHER THERE WILL
BE ENOUGH LIFT/MOISTURE TO OVERCOME DRY AIR NEAR SURFACE. BEST
LIFT COMES THU AFTERNOON AND ESPECIALLY FRI MORNING. BEST CHANCE
FOR PRECIPITATION THU WILL LIKELY BE IN SOUTHEAST KS IN THE
AFTERNOON. BY FRI MORNING DRIER AIR WILL HAVE OVERSPREAD THE
ENTIRE AREA. COLDER AIR SHOULD BE SPILLING INTO THE AREA ON
FRI...WITH HIGH TEMPERATURES LOWER THAN ON THU.
SAT-MON:
GOOD AGREEMENT THAT LARGE SURFACE HIGH WILL DROP SOUTH ACROSS THE
PLAINS ON SAT...WITH RETURN FLOW DEVELOPING ON SUN. HOWEVER SPREAD
BETWEEN GFS/ECMWF STARTS TO INCREASE SIGNIFICANTLY DUE TO HANDLING
OF SHORTWAVE MOVING THROUGH AND LONG WAVE TROUGH IN THE WESTERN
US. BOTH APPEAR TO BE OVERLY AGRESSIVE WITH RETURN MOISTURE ON SUN
AND MON AND HAVE OPTED TO KEEP FORECAST DRY FOR NOW. GIVEN SOUTHERN
EXTENT OF SURFACE HIGH AND SURFACE TRAJECTORIES DURING THE PERIOD...
SEEMS UNLIKELY TO GET SUFFICIENT MOISTURE THIS FAR NORTH THAT QUICK.
SHOULD SEE TEMPERATURES REBOUND NICELY GIVEN RELATIVELY DRY AIR/DRY
GROUND/SUNSHINE AND RETURN FLOW. -HOWERTON
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
KRSL-KSLN-KCNU WILL BE FLIRTING WITH LOW VFR TO HIGH MVFR CIGS
THIS AFTERNOON-EVENING...AND POSSIBLY THROUGH TONIGHT...AS
SHALLOW COLD AIR TIED TO ARCTIC HIGH PRESSURE ENCROACHES FROM THE
NORTHEAST. FOR NOW PLAYED THE CONSERVATIVE APPROACH...ALTHOUGH IF
LATEST RUC BUFR SOUNDINGS VERIFY CIGS LESS THAN 2000 FT AGL COULD
PREVAIL AS FAR SOUTH AS KHUT AND KICT BY MIDNIGHT. MODELS TEND TO
NOT HANDLE SHALLOW COLD AIRMASSES VERY WELL...SO WILL CONTINUE TO
MONITOR.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 20 45 26 52 / 0 0 0 0
HUTCHINSON 19 44 25 51 / 0 0 0 0
NEWTON 19 42 25 50 / 0 0 0 0
ELDORADO 18 41 25 52 / 0 0 0 0
WINFIELD-KWLD 21 46 27 57 / 0 0 0 0
RUSSELL 17 40 22 51 / 0 0 0 0
GREAT BEND 20 44 25 52 / 0 0 0 0
SALINA 17 38 22 49 / 0 0 0 0
MCPHERSON 18 42 24 50 / 0 0 0 0
COFFEYVILLE 19 44 27 58 / 0 0 10 10
CHANUTE 17 39 24 53 / 0 0 10 10
IOLA 17 37 24 51 / 0 0 0 0
PARSONS-KPPF 16 42 24 57 / 0 0 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
505 PM EST SUN JAN 20 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT TO CROSS THE REGION THIS EVENING. LOW PRESSURE
PASSES SOUTH OF THE AREA TUESDAY WITH A COLD AIR MASS TO REMAIN
ACROSS THE AREA ALL WEEK.&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE 1700L: PRIMARY ARCTIC BNDRY EXITING THE FA ATTM W/ SECONDARY
BNDRY ENTERING FAR NWRN AREAS. THIS SECONDARY BNSRY IS EXPECTED TO
SWEEP SEWRD ACROSS THE FA DURING THE EVE HRS AND WILL BE
ACCOMPANIED BY SOME SNOW SHOWERS SPCLY NRN AREAS. THIS FRONT WILL
BE FOLLOWED BY STRONG GUSTY NW WNDS AND STRONG CAA ALLOWING TEMPS
TO FALL RAPIDLY LATER THIS EVE AND THRU THE OVERNGT HRS. HAVE
ADJUSTED POPS TO BETTER FIT CURRENT AND EXPECTED TRENDS W/ ALL WND
CHILL WRNGS/ADVS AND THE WND ADV CONTG...
INTENSE AREA OF LOW PRESSURE CURRENTLY MOVING TO THE NORTH OF THE
STATE. LINE OF SNOW SHOWERS CURRENTLY MOVING THROUGH. SECONDARY
COLD FRONT STILL TO THE WEST OF NEW ENGLAND AND SHOULD MOVE ACROSS
THE STATE IN THE EARLY EVENING. EXPECT GUSTY CONDITIONS TO DEVELOP
AS COLD AIR MOVES IN. WILL KEEP WIND ADVISORY IN PLACE. HAVE
ADJUSTED WIND GUSTS A LITTLE LOWER FOR LATE AFTERNOON. FOR POP AND
WEATHER GRIDS HAVE INITIALIZED POPS WITH RUC13 THEN MANUALLY
ADJUSTED INCREASE POPS A LITTLE FURTHER TO SOUTH. LATER TONIGHT
EXPECT RAPID TEMPERATURE DROP ACCOMPANIED BY STRONG WINDS AND
GUSTY CONDITIONS SO WILL ALSO KEEP WIND CHILL ADVISORY FOR NORTH
AND WIND CHILL WATCH IN FAR NORTHWEST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
THE MAIN STORY FOR THIS PORTION OF THE FORECAST WILL BE BITTERLY
COLD TEMPERATURES. COMBINED WITH WITH THE BREEZY CONDITIONS WHICH
WILL CONTINUE MONDAY THIS WILL CREATE VERY LOW WIND CHILLS,
ESPECIALLY NORTH, WHERE VALUES WILL BE IN THE MINUS 20S AND MINUS
30S. HIGHS MONDAY IN THE NORTH WILL RANGE FROM 5 BELOW TO 5 ABOVE
ZERO WITH SOUTHERN AREAS SEEING HIGHS IN THE TEENS.
WINDS WILL ABATE FOR MONDAY NIGHT WITH TEMPERATURES DIPPING TO NEAR
OR BELOW MINUS 20 NORTH. ACROSS THE SOUTH, CLOUDS WILL INCREASE AS
A LOW PRESSURE SYSTEM DEVELOPS OFF THE MID ATLANTIC COAST AND
MOVES NORTH AND EAST. THE NORTHERN EDGE OF THE PRECIPITATION SHIELD
LOOKS TO SET UP VERY CLOSE TO COASTAL AREAS OF THE CWA WITH THE
NEW GFS TAKING THE SYSTEM SLIGHTLY FARTHER NORTH. IF THIS SOLUTION
WERE TO VERIFY IT COULD RESULT IN A COUPLE INCHES OF SNOW RIGHT
ALONG THE COAST. HOWEVER THE CANADIAN AND THE ECMWF REMAIN A BIT
FARTHER SOUTH SO AT THIS POINT OPTED TO MAINTAIN CONTINUITY WITH
PREVIOUS FORECAST KEEPING JUST CHANCE POPS IN ALONG THE COAST FOR
LATE MONDAY NIGHT INTO TUESDAY. OTHERWISE TUESDAY WILL FEATURE
MAINLY CLOUDY SKIES WITH VERY COLD TEMPERATURES. HIGHS LOOK TO BE
A COUPLE DEGREES COLDER THAN MONDAY`S VALUES MEANING MANY AREAS IN
THE NORTH WILL STAY AT OR BELOW ZERO.
AS THE AFOREMENTIONED LOW MOVES OFF TO THE NORTHEAST HEADING INTO TUESDAY
NIGHT AND WEDNESDAY THIS WILL DRAG THE CORE OF THE COLDEST AIR
DOWN OVER THE CWA. IN ADDITION, WINDS WILL PICK UP AGAIN WEDNESDAY
DUE TO THE GRADIENT BETWEEN THE DEPARTING LOW TO THE EAST AND HIGH
PRESSURE TO THE WEST. THIS WILL ONCE AGAIN RESULT IN BITTER WIND
CHILLS LIKELY REACHING AT LEAST ADVISORY LEVELS IN THE NORTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
IT LOOKS LIKE WE WILL GET A REPRIEVE FROM THIS LATEST ARCTIC
BLAST COME LATE WEEK AND THEN A RETURN TO ANOTHER POTENTIAL SHOT
OF ARCTIC AIR BY THE WEEKEND.
AN UPPER LEVEL IS FORECAST TO SWING ACROSS THE REGION BY WEDNESDAY
EVENING W/ANOTHER SHOT OF VERY COLD ARCTIC AIR TO INVADE THE
REGION. CLOUDS AND SCATTERED SNOW SHOWERS/FLURRIES WILL END BY
LATE EVENING W/SKIES CLEARING LATE IN THE NIGHT. THIS WILL SET THE
STAGE FOR ANOTHER VERY COLD NIGHT W/WINDS GRADUALLY DROP OFF AS
SFC HIGH PRES MOVES E FROM CANADA. WE COULD BE SEEING WIND CHILLS
HEADLINES AGAIN IN THURSDAY MORNING. A CAVEAT TO THIS IS THE ECMWF
AND THE CANADIAN GLOBAL AS THEY BOTH KEEP THE CENTER OF THE SFC
HIGH WELL W OF THE STATE BACK IN OTTAWA W/A WNW WIND CONTINUING.
THIS WOULD MEAN OVERNIGHT TEMPERATURES WEDNESDAY NIGHT WOULD BE A
BIT WARMER ALTHOUGH WELL BELOW NORMAL AND DAYTIME HIGH TEMPERATURES
FOR THURSDAY WILL BE COLDER AS WELL. ATTM, DECIDED TO BLEND THE
GMOS AND ECMWF FOR MINS WEDNESDAY NIGHT AND FOR MAXES ON THURSDAY
TAKING THIS INTO ACCOUNT.
THINGS LOOK TO BE INTERESTING COME FRIDAY INTO SATURDAY AS THE
LAST 2 RUNS OF THE ECMWF SHOW A LOW PRES SYSTEM COMING OUT OF THE
OHIO VALLEY AND MOVING ACROSS THE GULF OF MAINE. THE CANADIAN
GLOBAL INDICATES THE SAME IDEA AND BRING SIGNIFICANT SNOWFALL TO
EASTERN AND DOWNEAST MAINE AND POSSIBLY NORTHERN AREAS. THE GFS IS
WEAKER AND FASTER W/THE SFC LOW AND KEEPS THE LOW FURTHER S. SOME
OF THE INDIVIDUAL MEMBERS OF THE GFS DO SUPPORT THE ECMWF AND
CANADIAN GLOBAL SETUP. THEREFORE, A BLEND OF THE GMOS AND ECMWF
WAS USED FOR THIS TIME FRAME WHICH MEANS AN INCREASE IN POPS TO 40%
AND WENT W/SNOW INSTEAD OF SNOW SHOWERS. DECIDED TO BRING
TEMPERATURES UP AS WELL FOR FRIDAY INTO SATURDAY W/LOWER TEENS
ACROSS THE NORTH AND MID TEENS TO AROUND 20 CENTRAL AND DOWNEAST.
IT WILL INTERESTING TO SEE HOW THE LATER RUNS TREAT THIS POTENTIAL
SYSTEM.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: IFR CONDITIONS EARLY IN SNOW SQUALLS THEN VFR
CONDITIONS LATER TONIGHT INTO MONDAY.
SHORT TERM: VFR EXPECTED MONDAY INTO TUESDAY WITH THE EXCEPTION
OF KBHB AND POSSIBLY KBGR TUE AS -SN MAY PRODUCE A PERIOD OF
MVFR/IFR. A FEW PATCHES OF HIGHER END MVFR MAY BE FLOATING AROUND
IN THE COLD AIR IN THE NORTH WED-THU...BUT VFR SHOULD BY FAR BE
THE PREVAILING CONDITION.
&&
.MARINE...
NEAR TERM: EXPECT WINDS TO GRADUALLY BECOME OFF-SHORE LATER
TONIGHT. GRADIENT SLACKENS OFF BEFORE EXTREMELY COLD AIR GETS OVER
COASTAL WATERS SO NOT ENOUGH MIXING TO GET STORM WINDS TO SURFACE.
FOR WAVES: SOUTHWEST FETCH WILL END AS WINDS BECOME OFFSHORE. WAVE
HEIGHTS COULD TOP OFF AROUND 15 FEET BEFORE FETCH ENDS.
SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY NEED TO CONTINUE
INTO AT LEAST MONDAY MORNING BEFORE THE WIND DIMINISHES BELOW
ADVISORY LEVELS BY AFTERNOON. ANOTHER PERIOD OF SCA LEVEL WINDS
POSSIBLE BY LATE MONDAY NIGHT AS LOW PRESSURE PASSES SOUTH OF THE
WATERS. THERE WILL PROBABLY BE ENOUGH OF A PRESSURE GRADIENT IN
THE WAKE OF THE LOW AS HIGH PRESSURE BEGINS TO BUILD TOWARD THE
WATERS FOR BORDERLINE SCA WIND RIGHT THROUGH THURSDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MEZ001>006-010-
011-015>017-029>032.
WIND CHILL ADVISORY FROM 1 AM TO 1 PM EST MONDAY FOR MEZ002-
004>006-010.
WIND CHILL WARNING FROM 1 AM TO 1 PM EST MONDAY FOR MEZ001-003.
MARINE...GALE WARNING UNTIL 7 AM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...MIGNONE/KHW
SHORT TERM...FITZSIMMONS
LONG TERM...HEWITT
AVIATION...MIGNONE
MARINE...MIGNONE/KHW/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
343 PM EST SUN JAN 20 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT TO CROSS THE REGION THIS EVENING. LOW PRESSURE
PASSES SOUTH OF THE AREA TUESDAY WITH A COLD AIR MASS TO REMAIN
ACROSS THE AREA ALL WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
INTENSE AREA OF LOW PRESSURE CURRENTLY MOVING TO THE NORTH OF THE
STATE. LINE OF SNOW SHOWERS CURRENTLY MOVING THROUGH. SECONDARY
COLD FRONT STILL TO THE WEST OF NEW ENGLAND AND SHOULD MOV ACROSS
THE STATE IN THE EARLY EVENING. EXPECT GUSTY CONDITIONS TO DEVELOP
AS COLD AIR MOVES IN. WILL KEEP WIND ADVISORY IN PLACE. HAVE
ADJUSTED WIND GUSTS A LITTLE LOWER FOR LATE AFTERNOON. FOR POP AND
WEATHER GRIDS HAVE INITIALIZED POPS WITH RUC13 THEN MANUALLY
ADJUSTED INCREASE POPS A LITTLE FURTHER TO SOUTH. LATER TONIGHT
EXPECT RAPID TEMPERATURE DROP ACCOMPANIED BY STRONG WINDS AND
GUSTY CONDITIONS SO WILL ALSO KEEP WIND CHILL ADVISORY FOR NORTH
AND WIND CHILL WATCH IN FAR NORTHWEST.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
THE MAIN STORY FOR THIS PORTION OF THE FORECAST WILL BE BITTERLY
COLD TEMPERATURES. COMBINED WITH WITH THE BREEZY CONDITIONS WHICH
WILL CONTINUE MONDAY THIS WILL CREATE VERY LOW WIND CHILLS,
ESPECIALLY NORTH, WHERE VALUES WILL BE IN THE MINUS 20S AND MINUS
30S. HIGHS MONDAY IN THE NORTH WILL RANGE FROM 5 BELOW TO 5 ABOVE
ZERO WITH SOUTHERN AREAS SEEING HIGHS IN THE TEENS.
WINDS WILL ABATE FOR MONDAY NIGHT WITH TEMPERATURES DIPPING TO NEAR
OR BELOW MINUS 20 NORTH. ACROSS THE SOUTH, CLOUDS WILL INCREASE AS
A LOW PRESSURE SYSTEM DEVELOPS OFF THE MID ATLANTIC COAST AND
MOVES NORTH AND EAST. THE NORTHERN EDGE OF THE PRECIPITATION SHIELD
LOOKS TO SET UP VERY CLOSE TO COASTAL AREAS OF THE CWA WITH THE
NEW GFS TAKING THE SYSTEM SLIGHTLY FARTHER NORTH. IF THIS SOLUTION
WERE TO VERIFY IT COULD RESULT IN A COUPLE INCHES OF SNOW RIGHT
ALONG THE COAST. HOWEVER THE CANADIAN AND THE ECMWF REMAIN A BIT
FARTHER SOUTH SO AT THIS POINT OPTED TO MAINTAIN CONTINUITY WITH
PREVIOUS FORECAST KEEPING JUST CHANCE POPS IN ALONG THE COAST FOR
LATE MONDAY NIGHT INTO TUESDAY. OTHERWISE TUESDAY WILL FEATURE
MAINLY CLOUDY SKIES WITH VERY COLD TEMPERATURES. HIGHS LOOK TO BE
A COUPLE DEGREES COLDER THAN MONDAY`S VALUES MEANING MANY AREAS IN
THE NORTH WILL STAY AT OR BELOW ZERO.
AS THE AFOREMENTIONED LOW MOVES OFF TO THE NORTHEAST HEADING INTO TUESDAY
NIGHT AND WEDNESDAY THIS WILL DRAG THE CORE OF THE COLDEST AIR
DOWN OVER THE CWA. IN ADDITION, WINDS WILL PICK UP AGAIN WEDNESDAY
DUE TO THE GRADIENT BETWEEN THE DEPARTING LOW TO THE EAST AND HIGH
PRESSURE TO THE WEST. THIS WILL ONCE AGAIN RESULT IN BITTER WIND
CHILLS LIKELY REACHING AT LEAST ADVISORY LEVELS IN THE NORTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
IT LOOKS LIKE WE WILL GET A REPRIEVE FROM THIS LATEST ARCTIC
BLAST COME LATE WEEK AND THEN A RETURN TO ANOTHER POTENTIAL SHOT
OF ARCTIC AIR BY THE WEEKEND.
AN UPPER LEVEL IS FORECAST TO SWING ACROSS THE REGION BY WEDNESDAY
EVENING W/ANOTHER SHOT OF VERY COLD ARCTIC AIR TO INVADE THE
REGION. CLOUDS AND SCATTERED SNOW SHOWERS/FLURRIES WILL END BY
LATE EVENING W/SKIES CLEARING LATE IN THE NIGHT. THIS WILL SET THE
STAGE FOR ANOTHER VERY COLD NIGHT W/WINDS GRADUALLY DROP OFF AS
SFC HIGH PRES MOVES E FROM CANADA. WE COULD BE SEEING WIND CHILLS
HEADLINES AGAIN IN THURSDAY MORNING. A CAVEAT TO THIS IS THE ECMWF
AND THE CANADIAN GLOBAL AS THEY BOTH KEEP THE CENTER OF THE SFC
HIGH WELL W OF THE STATE BACK IN OTTAWA W/A WNW WIND CONTINUING.
THIS WOULD MEAN OVERNIGHT TEMPERATURES WEDNESDAY NIGHT WOULD BE A
BIT WARMER ALTHOUGH WELL BELOW NORMAL AND DAYTIME HIGH TEMPERATURES
FOR THURSDAY WILL BE COLDER AS WELL. ATTM, DECIDED TO BLEND THE
GMOS AND ECMWF FOR MINS WEDNESDAY NIGHT AND FOR MAXES ON THURSDAY
TAKING THIS INTO ACCOUNT.
THINGS LOOK TO BE INTERESTING COME FRIDAY INTO SATURDAY AS THE
LAST 2 RUNS OF THE ECMWF SHOW A LOW PRES SYSTEM COMING OUT OF THE
OHIO VALLEY AND MOVING ACROSS THE GULF OF MAINE. THE CANADIAN
GLOBAL INDICATES THE SAME IDEA AND BRING SIGNIFICANT SNOWFALL TO
EASTERN AND DOWNEAST MAINE AND POSSIBLY NORTHERN AREAS. THE GFS IS
WEAKER AND FASTER W/THE SFC LOW AND KEEPS THE LOW FURTHER S. SOME
OF THE INDIVIDUAL MEMBERS OF THE GFS DO SUPPORT THE ECMWF AND
CANADIAN GLOBAL SETUP. THEREFORE, A BLEND OF THE GMOS AND ECMWF
WAS USED FOR THIS TIMEFRAME WHICH MEANS AN INCREASE IN POPS TO 40%
AND WENT W/SNOW INSTEAD OF SNOW SHOWERS. DECIDED TO BRING
TEMPERATURES UP AS WELL FOR FRIDAY INTO SATURDAY W/LOWER TEENS
ACROSS THE NORTH AND MID TEENS TO AROUND 20 CENTRAL AND DOWNEAST.
IT WILL INTERESTING TO SEE HOW THE LATER RUNS TREAT THIS POTENTIAL
SYSTEM.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: IFR CONDITIONS EARLY IN SNOW SQUALLS THEN VFR
CONDITIONS LATER TONIGHT INTO MONDAY.
SHORT TERM: VFR EXPECTED MONDAY INTO TUESDAY WITH THE EXCEPTION
OF KBHB AND POSSIBLY KBGR TUE AS -SN MAY PRODUCE A PERIOD OF
MVFR/IFR. A FEW PATCHES OF HIGHER END MVFR MAY BE FLOATING AROUND
IN THE COLD AIR IN THE NORTH WED-THU...BUT VFR SHOULD BY FAR BE
THE PREVAILING CONDITION.
&&
.MARINE...
NEAR TERM: EXPECT WINDS TO GRADUALLY BECOME OFF-SHORE LATER
TONIGHT. GRADIENT SLACKENS OFF BEFORE EXTREMELY COLD AIR GETS OVER
COASTAL WATERS SO NOT ENOUGH MIXING TO GET STORM WINDS TO SURFACE.
FOR WAVES: SOUTHWEST FETCH WILL END AS WINDS BECOME OFFSHORE. WAVE
HEIGHTS COULD TOP OFF AROUND 15 FEET BEFORE FETCH ENDS.
SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY NEED TO CONTINUE
INTO AT LEAST MONDAY MORNING BEFORE THE WIND DIMINISHES BELOW
ADVISORY LEVELS BY AFTERNOON. ANOTHER PERIOD OF SCA LEVEL WINDS
POSSIBLE BY LATE MONDAY NIGHT AS LOW PRESSURE PASSES SOUTH OF THE
WATERS. THERE WILL PROBABLY BE ENOUGH OF A PRESSURE GRADIENT IN
THE WAKE OF THE LOW AS HIGH PRESSURE BEGINS TO BUILD TOWARD THE
WATERS FOR BORDERLINE SCA WIND RIGHT THROUGH THURSDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MEZ001>006-010-
011-015>017-029>032.
WIND CHILL ADVISORY FROM 1 AM TO 1 PM EST MONDAY FOR MEZ002-
004>006-010.
WIND CHILL WARNING FROM 1 AM TO 1 PM EST MONDAY FOR MEZ001-003.
MARINE...GALE WARNING UNTIL 7 AM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...MIGNONE
SHORT TERM...FITZSIMMONS
LONG TERM...HEWITT
AVIATION...MIGNONE
MARINE...MIGNONE/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
631 PM EST MON JAN 21 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 432 PM EST MON JAN 21 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A HIGH AMPLITUDE
PATTERN OVER NAMERICA WITH A RIDGE ALONG THE W COAST THRU AK AND A
DEEP TROF OVER ERN NAMERICA. BEHIND SHORTWAVE THAT HAS PASSED ACROSS
THE AREA...BITTER COLD ARCTIC AIR IS FLOWING OVER THE UPPER GREAT
LAKES. PER 12Z RAOBS...CORE OF THE COLDEST AIR THIS MORNING WAS JUST
UPSTREAM AS KINL SOUNDING SHOWED 850MB TEMP AT A VERY LOW -35C. JUST
N AT CWPL...850MB TEMP WAS AN UNUSUALLY LOW -38C. WITH CAA TODAY...
TEMPS HAVE STRUGGLED TO RISE WITH SUBZERO READINGS THE RULE OVER
ROUGHLY THE W HALF OF UPPER MI JUST INLAND FROM LAKE SUPERIOR. AT
KIWD...TEMP HAS ONLY REACHED -11F. OVER THE E...TEMPS HAVE HELD IN
THE SINGLE DIGITS ABOVE ZERO. WIND CHILLS REMAIN GENERALLY IN THE
-20 TO -35F RANGE OVER THE W HALF AND -10 TO -20F E. WITH EXTREME
INSTABILITY OVER THE LAKE...LES OBVIOUSLY CONTINUES FOR MAINLY THE
SNOWBELTS FAVORED BY NW WINDS. AS EXPECTED...WITH VERY COLD AIR
ELIMINATING THE DGZ...SNOWFLAKE SIZE HAS BEEN VERY SMALL. THE SMALL
SNOWFLAKES ARE VERY EFFECTIVE AT REDUCING VIS...SO WHERE LES IS
OCCURRING...WHITE-OUTS ARE COMMON. SMALL FLAKES ARE LIMITING
ACCUMULATIONS WITH MOST SPOTTER/COOP REPORTS INDICATING MOSTLY
1-3IN/12HR SNOWFALL RATES. EXCEPTION IS OVER THE FAR NE FCST
AREA...THOUGH REPORTS ARE DIFFICULT TO OBTAIN. ONE REPORT AT UPPER
TAHQUAMENON FALLS WHICH HAS BEEN UNDER A NEARLY STEADY DOMINANT BAND
INDICATED ABOUT 7 INCHES OF SNOW SINCE EARLY THIS MORNING. STRONG
CONVERGENCE ZONE OWING TO LAKE INDUCED TROFFING AND STRENGTHENED BY
STRONG LAND BREEZES IS LIKELY ALLOWING ENOUGH LAKE MODERATION TO
PUSH DGZ UP INTO AT LEAST A PORTION OF THE CONVECTIVE LAYER.
SO...SOME RATHER SIGNIFICANT SNOW ACCUMULATIONS HAVE PROBABLY
OCCURRED OVER THE LAST 12-18HRS OVER SOME PORTIONS OF ERN ALGER/NRN
SCHOOLCRAFT/NRN LUCE COUNTIES.
CORE OF ARCTIC AIR WILL DROP ACROSS THE AREA TONIGHT. IN THE WAKE OF
THE SHORTWAVE THAT PASSED TODAY AND WITHOUT ANY ADDITIONAL
SHORTWAVES APPROACHING...FCST SOUNDINGS SHOW A GRADUAL DECREASE IN
CONVECTIVE/MOIST LAYER...ESPECIALLY DURING THE DAY TUE AS HEIGHTS
BEGIN TO RISE. SO...TONIGHT WILL ESSENTIALLY BE JUST A CONTINUATION
OF WHAT HAS BEEN HAPPENING TODAY. OVER THE W...EXPECT MOSTLY 1-3IN
ACCUMULATIONS TONIGHT...THOUGH LOCALIZED 4 INCH AMOUNTS COULD OCCUR
BTWN KIWD AND THE VCNTY OF THE PORCUPINE MTNS DUE TO ENHANCED
CONVERGENCE FROM STRENGTHENING LAND BREEZE OFF NW WI. POOR VIS WILL
BE THE BIGGER STORY WITH THE SNOW AS WHITE-OUTS WILL CONTINUE TO BE
COMMON DUE TO THE VERY SMALL SNOWFLAKE SIZE. TO THE E...
STRENGTHENING LAND BREEZES WILL AGAIN STRENGTHEN THE CONVERGENCE
ZONE OVER SCNTRL AND ERN LAKE SUPERIOR INTO PORTIONS OF
ALGER/LUCE/NRN SCHOOLCRAFT COUNTIES. MOST GUIDANCE INDICATES A SHARP
SFC TROF RATHER THAN MESOLOW DEVELOPMENT...SO THERE IS MORE
CONFIDENCE IN MAINTAINING MDT/HVY SNOW STREAMING ONSHORE IN THAT
AREA THRU THE NIGHT RATHER THAN HAVING SNOW SHIFT N AND POSSIBLY
MOSTLY OFFSHORE IF A MESOLOW DEVELOPED. WHERE HEAVIEST SNOW IS MOST
PERSISTENT...MAY SEE UPWARDS OF 8 INCHES TONIGHT.
OTHER OBVIOUS STORY IS THE COLD. GIVEN HOW LOW 850MB TEMPS ARE...
SFC TEMPS WOULD TANK TO READINGS NOT SEEN IN UPPER MI FOR MANY YEARS
IF WINDS WERE TO DROP OFF TO CALM TONIGHT. HOWEVER...SINCE WINDS
STAY UP...TEMPS WON`T FALL SIGNIFICANTLY TONIGHT. OVER ROUGHLY THE W
HALF INLAND FROM LES...TEENS BLO ZERO SHOULD BE THE RULE WITH A FEW
SPOTS POSSIBLY FALLING TO AROUND -20F. ELSEWHERE...EXPECT SINGLE
DIGITS BLO ZERO. ONLY LOCATIONS THAT PROBABLY WON`T FALL BLO ZERO
WILL BE RIGHT ALONG THE SHORE E OF MUNISING. WINDS SHOULD STAY UP
NEAR THE 10MPH THRESHOLD FOR WIND CHILL ADVY...SO ADVYS WILL REMAIN
UP FOR -25 TO -35F WIND CHILLS. WILL BE FLIRTING WITH WARNING
CRITERIA (-35F OR LWR) TOWARD THE WI BORDER W OF KIMT.
AIR MASS BEGINS TO SLOWLY MODERATE TUE...BUT STILL REMAINS COLD
ENOUGH TO KEEP DGZ OUT OF THE CONVECTIVE LAYER. SO...MORE FINE VIS
RESTRICTING LES IS EXPECTED. SMALL FLAKES COMBINED WITH HEIGHT RISES
AND DECREASING CONVECTIVE/MOIST LAYER WILL CONTINUE TO KEEP
ACCUMULATIONS ON THE LIGHT SIDE...ESPECIALLY OVER THE W. WILL
PROBABLY BEGIN TO SEE MORE GAPS/SEPARATION BTWN LES BANDS AS
LOW-LEVEL DRY AIR MAY BEGIN TO MAKE MORE OF AN IMPACT. OVER THE
E...MDT/HVY LES IN THE MORNING SHOULD ALSO BEGIN TO DIMINISH GIVEN
LARGER SCALE NEGATIVES PREVIOUSLY MENTIONED. TEMPS SHOULD RISE ABOVE
0F IN MOST AREAS...THOUGH OVER THE W HALF...SOME READINGS WILL
LIKELY FALL JUST SHORT OF 0F.
AS FOR HEADLINES...WILL BE ADDING MENOMINEE/DELTA TO WIND CHILL ADVY
TONIGHT/TUE MORNING AND WILL BE EXTENDING LES WARNING FOR
ALGER/LUCE/NRN SCHOOLCRAFT THRU TUE AFTN.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 432 PM EST MON JAN 21 2013
GIVEN THE PERSISTENT 500MB LOW SET UP THROUGH WEDNESDAY...EXPECT THE
COLD WEATHER TO LINGER THROUGH AT LEAST WEDNESDAY MORNING. LES WILL
CONTINUE TO BE A NUISANCE THROUGH WEDNESDAY EVENING.
TUESDAY NIGHT AND WEDNESDAY...
DOUBLE DIGIT BELOW ZERO READINGS WILL BE THE RULE AGAIN TUESDAY
NIGHT. PERSISTENT W TO WNW FLOW OVER THE WARM WATERS OF LAKE
SUPERIOR...AND SLIGHTLY WARMER TEMPS JUST ABOVE THE SFC /850MB
WARMING FROM -27/-24C TO AROUND -23/-22C OVERNIGHT BASED OFF THE
ECMWF/GFS/. WITH DIMINISHING WINDS OVERNIGHT...WIND CHILLS READINGS
WILL BE LESS IMPRESSIVE THAN THE LAST COUPLE OF NIGHTS...BOTTOMING
OUT NEAR -25 TO -28F NEAR IWD...WITH THE COLDEST VALUES PRIOR TO
MIDNIGHT. THE DGZ WILL PUSH FROM THE SFC UP THROUGH 900MB...AND
LINGER AT THOSE LEVELS THROUGH WEDNESDAY. WITH PLENTY OF LINGERING
MOISTURE...EXPECT SOME MODERATE ACCUMULATIONS TUESDAY NIGHT OVER THE
KEWEENAW PENINSULA AND NEAR AND E OF GRAND MARAIS...TRANSITIONING TO
ALL AREAS NEAR LAKE SUPERIOR ON BY LATE WEDNESDAY WITH ENHANCEMENT
FROM THE EXITING SFC LOW SWITCHING WINDS TO A W/NW DIRECTION AND A
PASSING WAVE ALOFT. ALSO EXPECT MODERATING TEMPS WEDNESDAY...AS
850MB TEMPS REMAIN NEAR -21C. AN ADDITIONAL 4-7IN OF SNOW MAY BE
POSSIBLE ACROSS PORTIONS OF THE KEWEENAW PENINSULA...WITH LESSER
AMOUNTS ELSEWHERE NEAR LAKE SUPERIOR.
WEDNESDAY NIGHT...
THE MODERATE LAKE TO 700 AND 850MB TEMP DIFFERENCES WILL REMAIN. THE
LATEST INDICATIONS ARE THAT THE BEST CONVERGENT WINDS N AT THE SFC
WILL BE FROM BIG BAY THROUGH MQT/SAW AND MUNISING EARLY IN THE
EVENING...BEFORE LIGHT AND MORE VARIABLE WINDS ATTEMPT TAKE HOLD
OVERNIGHT. MODEL CONSISTENCY PAST LATE EVENING IS STILL A BIT FLAKY
AT THIS POINT...SO WILL HOLD OFF ON GOING ADDING TOO MUCH DETAIL TO
THE EXPECTED SNOW AMOUNTS EXCEPT TO HIGHLIGHT N CENTRAL AND AREAS
FROM IWD TO ROCKLAND.
TOTAL SNOWFALL FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT /36HRS/
WILL LIKELY TOP OUT IN THE 7 TO 10IN RANGE E OF MUNISING TO
WHITEFISH PT...AND FROM ONTONAGON UP THROUGH TWIN LAKES AND
PAINESDALE. ADVISORIES...ALTHOUGH NOT POSTED AT THIS TIME DUE TO
CURRENT HEADLINES AND DISTANCE OUT...WILL PROBABLY BE
NEEDED...PARTICULARLY IF THE LAKE INDUCED MESO LOW DEVELOPS OVER FAR
EAST AS HAS BEEN SHOWN OVER THE PAST DAY OR SO. MODERATE TO HEAVY
SNOW WOULD BE LIKELY OVER LUCE AND POSSIBLY FAR E ALGER COUNTY.
THURSDAY THROUGH NEXT MONDAY...
WILE THE 21/06 GFS DIVERGED SIGNIFICANTLY FROM THE THE
NAM/ECMWF/CANADIAN DIVERGE FROM THE GFS THURSDAY...WITH ITS SOLUTION
BEING ROUGHLY 12HRS SLOWER WITH THE NEXT SHORTWAVE OVER SW CANADA.
THE 21/12Z GFS SEEMS TO HAVE CORRECTED THIS ISSUE FOR THE MOST
PART...WITH LESS DEVIATION BETWEEN SOLUTIONS THROUGH THE PASSAGE OF
THE TROUGH OVER THE UPPER GREAT LAKES THURSDAY NIGHT INTO FRIDAY.
KEPT EXTENDED POPS IN THE CHANCE RANGE AT THE HIGHEST FOR NOW GIVEN
THE OVERALL LIGHTER FLOW. LOW TEMPS WILL BRIEFLY RETURN TO BELOW
ZERO VALUES FRIDAY NIGHT OVER THE INTERIOR W HALF...BEFORE SLOWLY
RISING. HAVE HIGH TEMPS RISING TO AROUND FREEZING MONDAY AFTERNOON
AS 850MB TEMPS RISE INTO THE SINGLE DIGITS BELOW 0C.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 630 PM EST MON JAN 21 2013
LAKE EFFECT SNOW SHOWERS WILL CONTINUE OVER MAINLY THE IWD AND CMX
TAF SITES THROUGH TUESDAY AFTERNOON. VISIBILITY WILL BE REDUCED TO
1/4 MILE AT TIMES AS THE HEAVIER SNOWBANDS MOVE THROUGH. IWD WILL
LIKELY SEE A BRIEF BREAK IN THE SNOW SHOWERS EARLY THIS EVENING
BEFORE THE NEXT AREA OF SNOW SHOWERS BUILDS SOUTHWARD INTO THE SITE.
WINDS WILL ALSO BE GUSTING TO 20 KTS OR BETTER ALLOWING FOR
INCREASED BLSN POTENTIAL...ALSO HELPING TO REDUCE VSBY. CEILINGS ARE
EXPECTED TO REMAIN AROUND 1500 TO 2000 FT AT CMX AND IWD.
KSAW WILL REMAIN AT MVFR THROUGH TUESDAY MORNING AS INCREASED
MOISTURE MOVES INTO THE TAF SITE. DOWNSLOPING WESTERLY WINDS WILL
HELP TO ERODE THE CLOUD COVER THROUGH THE LATE MORNING AND EARLY
AFTERNOON HOURS...POSSIBLY SCATTERING OUT BY 19Z. VSBY SHOULD REMAIN
VFR THROUGH THE TAF PERIOD WITH ONLY MINOR REDUCTION IN VSBY THIS
EVENING WITH GUSTY WINDS CREATING BLSN. WEST TO NORTHWEST WINDS ARE
NOT A FAVORED LAKE EFFECT DIRECTION FOR KSAW...THEREFORE HAVE KEPT
-SHSN OUT OF THE TAF ALTHOUGH A FEW SNOW SHOWERS ARE STILL POSSIBLE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EST MON JAN 21 2013
WITH VERY COLD ARCTIC AIR FLOWING OVER LAKE SUPERIOR...NW WINDS WILL
STAY IN THE 20-30KT RANGE TONIGHT. EXPECT SOME GALE FORCE GUSTS OVER
THE CNTRL PORTION OF THE LAKE JUST W OF SFC TROFFING OVER ERN LAKE
SUPERIOR. WINDS WILL ONLY DIMINISH SLIGHTLY INTO MOSTLY THE 15-25KT
RANGE TUE. VERY COLD AIR WILL COMBINE WITH WINDS/WAVES TO PRODUCE
PERIODS OF HEAVY FREEZING SPRAY TONIGHT/TUE. HEAVY FREEZING SPRAY
WILL CONTINUE THROUGH WEDNESDAY EVENING...MAINLY ACROSS THE S
SHORELINE OF LAKE SUPERIOR. WITH HIGH PRESSURE PUSHING IN THURSDAY
WIND WILL BECOME LIGHT AND VARIABLE...WITH LITTLE WAVES AND A SLIGHT
WARM UP /LIMITING THE POTENTIAL FOR FREEZING SPRAY/. N-NW WILL
INCREASE FRIDAY...WITH A FEW GUSTS NEARING 20-25KTS. OTHERWISE LIGHT
WINDS LESS THAN 20KTS CAN BE EXPECTED FROM THURSDAY THROUGH SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ TUESDAY FOR
MIZ001>003-009-084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST TUESDAY FOR MIZ006-007-
085.
WIND CHILL ADVISORY UNTIL 1 PM EST /NOON CST/ TUESDAY FOR MIZ004-
005-010-011.
WIND CHILL ADVISORY UNTIL 1 PM EST /NOON CST/ TUESDAY FOR MIZ012-
013.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ WEDNESDAY
FOR LSZ240>251-263>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ TUESDAY
FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...KEC
MARINE...ROLFSON/KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
500 PM EST SUN JAN 20 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 455 PM EST SUN JAN 20 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGH AMPLITUDE PATTERN
OVER NAMERICA WITH A RIDGE ALONG THE W COAST THRU AK AND A DEEP TROF
COVERING MUCH OF CNTRL/ERN CANADA INTO THE NCNTRL CONUS/GREAT LAKES.
BEHIND LAST NIGHTS SHORTWAVE PASSAGE...INCREASINGLY COLDER ARCTIC
AIR IS FLOWING INTO THE AREA. LATEST RUC ANALYSIS SHOWS 850MB TEMPS
OF -22 TO -24C OVER UPPER MI/LAKE SUPERIOR. UPSTREAM 850MB TEMPS ON
12Z ROABS WERE -25C/-26C/-27C AT KINL/CWPL/CYQD RESPECTIVELY.
FARTHER UPSTREAM...POOL OF SUB -30C AIR AT 850MB IS JUST NW OF CYQD
AS 00Z RAOB AT CYSM SHOWED -34C AT 850MB. THAT CORE OF ARCTIC AIR
WILL BE SETTLING INTO THE UPPER LAKES MON/MON NIGHT BEHIND SHORTWAVE
CURRENTLY DROPPING SSE THRU MANITOBA. ANOTHER WEAKER SHORTWAVE IS
PASSING THRU THE UPPER GREAT LAKES ATTM. HOWEVER...WAVE HAS HAD NO
DISCERNIBLE INFLUENCE ON LES PER RADAR IMAGERY. MOST INTENSE LES
BAND IS STREAMING INTO WRN ALGER COUNTY AS LAND BREEZE COMPONENT
STRENGTHENS CONVERGENCE OFF MARQUETTE COUNTY. TO THE W...WIND
PARALLEL LES BANDS ARE STREAMING INTO WRN UPPER MI. WEBCAMS SHOW
HIGHLY VARIABLE VIS AS -SHSN PASS. SINCE ARCTIC AIR HAS PUSHED DGZ
TO NEAR THE SFC...SNOWFLAKE SIZE IS SMALL...MAKING THE -SHSN VERY
EFFECTIVE AT REDUCING VIS. THIS IS ALSO KEEPING NEW SNOW
ACCUMULTIONS ON THE LIGHT SIDE OVER THE W.
AFOREMENTIONED SHORTWAVE IN MANITOBA WILL DROP ACROSS THE UPPER
LAKES OVERNIGHT TONIGHT THRU MON MORNING. FORCING ASSOCIATED WITH
WAVE PER DEEP LAYER QVECTOR CONVERGENCE WILL GIVE A BOOST TO LES
TONIGHT THRU MID MORNING MON AS MOISTURE DEPTH INCREASES AND
INVERSION RISES TO AROUND 10KFT. NORMALLY WITH SUCH SYNOPTIC
ENHANCEMENT...WOULD BE CONCERNED ABOUT A SIGNIFICANT INCREASE IN HVY
LES/SNOW ACCUMULATIONS. HOWEVER...WITH INCREASINGLY COLDER AIR
CONTINUING TO PUSH DGZ TOWARD THE SFC OR MORE LIKELY ELIMINATING IT
ALTOGETHER...SNOW ACCUMULATIONS WILL BE LIMITED BY SMALL SNOWFLAKE
SIZE. ONLY AREAS LIKELY TO SEE MORE SIGNIFICANT SNOW ACCUMULATIONS
WILL BE THOSE THAT ARE IMPACTED BY LES WITHIN STRONGER CONVERGENCE
ZONES AS THE CONVERGENCE WILL PROVIDE AN OPPORTUNITY FOR MORE
SIGNIFICANT LAKE MODERATION AND THUS POSSIBLY RAISE DGZ INTO A
PORTION OF THE CONVECTIVE LAYER. THOSE ENHANCED CONVERGENCE ZONES
WILL BE DIFFICULT TO PIN DOWN EXACTLY...BUT THERE SHOULD BE 2 OR 3.
ONE SHOULD OCCUR IN ONTONAGON COUNTY...PROBABLY AROUND THE VCNTY OF
THE PORCUPINE MTNS DUE TO STRENGTHENING LAND BREEZE OFF NW WI. THE
OTHERS SHOULD BE IN ERN ALGER COUNTY AND A PORTION OF LUCE COUNTY
DUE TO STRENGTHENING LAND BREEZES OFF MARQUETTE/WRN ALGER COUNTY AND
ALSO OFF ONTARIO. ALL HIGH RES MODEL GUIDANCE POINT TOWARD THE
PROGRESSING LAND BREEZES OVER SCNTRL/ERN LAKE SUPERIOR LEADING TO
EITHER MESO LOW DEVELOPMENT OR SHARP SFC TROFFING SOMEWHERE IN THE
AREA BTWN GRAND MARAIS/CARIBOU ISLAND AND WHITEFISH PT. IF A MESO
LOW DEVELOPS FAR ENOUGH OFFSHORE...IT`S POSSIBLE MOST OF THE LES
WILL ALSO SHIFT OFFSHORE. IF A SHARP CONVERGENCE ZONE DEVELOPS...
MDT/HVY LES COULD STREAM ONSHORE INTO A SMALL PART OF ERN ALGER/NW
LUCE FOR SEVERAL HRS. WITH PASSAGE OF SHORTWAVE...AT SOME POINT MON
MORNING/EARLY AFTN...THE SHARP SFC TROF/MESO LOW WILL BE PUSHED
ONSHORE. GIVEN THE UNCERTAINTY ON THE MESOSCALE DETAILS...WILL
CONTINUE TO HIGHLIGHT ERN ALGER/NRN LUCE CLOSE THE LAKE FOR GREATEST
ACCUMULATIONS TONIGHT/MON WITH POSSIBLE LOCALIZED 6-11 INCH AMOUNTS.
IF SOMETHING SETS UP AND REMAINS STATIONARY...COULD EASILY SEE OVER
A FOOT OF SNOW. OVER THE W...BITTER COLD ARCTIC AIR IS MORE LIKELY
TO ELIMINATE DGZ ALTOGETHER...RESULTING IN VERY SMALL SNOWFLAKES AND
LIMITING SNOW ACCUMULATIONS TO PROBABLY NOTHING MORE THAN 1-2 TO
PERHAPS 3 INCHES PER 12HR PERIOD. LOCALIZED ACCUMULATIONS OF MAYBE
4-5 INCHES WILL BE POSSIBLE IN THE EXPECTED CONVERGENCE ZONE IN
ONTONAGON COUNTY. RATHER THAN SNOW ACCUMULATIONS...THE BIGGER
CONCERN WILL BE VERY LOW VIS AS THE SMALL SNOWFLAKES WILL BE
EXTREMELY EFFECTIVE AT REDUCING VISIBILITY. MAY END UP WITH VERY LOW
VIS/NEAR WHITE-OUT CONDITIONS WHENEVER SNOW SHOWERS PASS DUE TO THE
CONSIDERABLE AMOUNT OF FINE SNOWFLAKES IN THE AIR. THIS TYPE OF FINE
SNOW IS ALSO VERY EASILY BLOWN ABOUT BY VEHICLES...SO VIS ON ROADS
WILL BE ESPECIALLY LOW IN THE VCNTY OF OTHER VEHICLES...MAKING
TRAVEL DANGEROUS DESPITE THE LACK OF SIGNIFICANT SNOW ACCUMULATIONS.
CONSIDERING VIS IMPACTS RATHER THAN SNOW IMPACTS...WILL BE ISSUING A
WINTER WX ADVY FOR ONTONAGON/HOUGHTON/KEWEENAW THRU TUE MORNING TO
HIGHLIGHT VERY POOR VIS IN SHSN AND ALSO TO COVER WIND CHILLS WHICH
WILL BE FALLING TO AROUND THE WIND CHILL ADVY CRITERIA OF -25F.
OTHER CONCERN TONIGHT/MON WILL BE THE BITTER COLD AIR. POOL OF SUB
-30C AIR AT 850MB ADVECTING INTO THE UPPER LAKES MON SUGGESTS MOST
OF THE W HALF OF UPPER MI AWAY FROM IMMEDIATE LAKE SUPERIOR
INFLUENCE WILL STAY BLO ZERO DURING THE DAY MON. IN FACT...IT MAY BE
A STRUGGLE TO RISE MUCH ABOVE -10F ACROSS GOGEBIC COUNTY WHERE LAKE
MODERATION WILL BE LEAST. OTHERWISE...SINGLE DIGITS BLO ZERO SHOULD
BE THE RULE FOR HIGHS OVER THE W MON. WHILE IT`S OFTEN TOUGH TO KEEP
WINDS AOA THE 10MPH THRESHOLD AT NIGHT...CAA MAY BE ENOUGH TO KEEP
WINDS UP SUFFICIENTLY TO SATISFY WIND CHILL CRITERIA LATER TONIGHT.
HAVE EXPANDED WIND CHILL ADVY TO COVER ROUGHLY THE W HALF OF UPPER
MI OUTSIDE OF AFOREMENTIONED WINTER WX ADVY AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 455 PM EST SUN JAN 20 2013
AGREEMENT REMAINS GOOD IN THE LARGE SCALE PATTERN FOR THE UPCOMING
WEEK. MODELS ARE NOW EVEN IN OKAY AGREEMENT IN THEIR HANDLING OF
BREAKING DOWN THE DEEP TROUGH OVER THE AREA TO START THE WEEK AND
RESULTING SFC LOW MOVING FROM CENTRAL PLAINS ACROSS THE OHIO VALLEY
THURSDAY INTO FRIDAY.
BY LATE MONDAY GRIP OF COLD WILL BE IN FULL FORCE WITH H85 TEMPS
NEAR -30C OVER FAR WEST AND H95 TEMPS BLO -20C. NO REAL CHANGE TO
EXPECTED MSLP PATTERN WITH LAKE INDUCED TROUGHING AS FAR NORTH AS
EASTERN LK SUPERIOR WHILE HIGH PRESSURE IS CENTERED FROM SOUTHERN
SASKATCHEWAN INTO SOUTHERN MN AND IOWA. RESULT IS PERSISTENT
UNIDIRECTIONAL NW FLOW SFC-H5 ALLOWING LK EFFECT TO CONTINUE. AS IT
HAS APPEARED LAST COUPLE DAYS...MOST CONCENTRATED AND HEAVIEST LK
EFFECT WILL BE OVER FAR NORTHEAST CWA ALONG LK SUPERIOR...EAST OF
MUNISING TO NORTH OF SENEY AND NEWBERRY. AVAILABLE HIGHER RESOLUTION
MODELS STILL PEGGING QPF AMOUNTS OVER 0.20 INCH/12 HR FOR MON NIGHT
AND TUESDAY AND TUESDAY NIGHT. NO DOUBT CONVERGENCE WILL BE
MAXIMIZED DUE TO LARGE SCALE LAKE INDUCED TROUGHING AND ASSOCIATED
MESOLOW FORMING OVER SOUTHEAST LK SUPERIOR DUE TO LAND BREEZES OFF
UPR MICHIGAN AND ONTARIO. AS ALLUDED TO IN SHORT TERM DISCUSSION...
EXACTLY WHERE HEAVIER SNOW BANDS TIED TO THIS MESOSCALE FEATURE SET
UP IS HARD TO PIN DOWN.
MAIN ADJUSTMENT TO QPF/SNOW WAS TO KEEP HIGHER AMOUNTS CLOSER TO
SHORE THAN WHAT MODELS SHOW AS USUALLY LAND BREEZE DOMINATED
CONVERGENCE ZONE ENDS UP CLOSER TO THE LAKE THAN MODELS PORTRAY.
GIVEN THE VERY COLD AIRMASS...SLR/S WILL BE LESS THAN 15:1. OUTSIDE
OF AREAS WHERE STRONGEST CONVERGENCE/MOISTURE FLUXES OCCUR SLR/S
PROBABLY END UP MORE TOWARD 10:1 AS VERY FINE SNOWFLAKES DOMINATE.
SNOW AMOUNTS LIKELY END UP 3-5 INCHES EVERY 12 HRS UNDER DOMINATE
BAND IN THE EAST...BUT FOR REST OF AREAS FAVORED BY NW FLOW ALONG LK
SUPERIOR EXPECT JUST A FEW INCHES EVERY 12 HRS. DUE TO MODERATE SNOW
AMOUNTS SNOW AND POOR VSBY ALONG WITH POSSIBILITY OF DOMINATE BAND
ENHANCING SNOW AMOUNTS...COORD WITH SHORT TERM FORECASTER AND
EXTENDED LK EFFECT SNOW WARNING FOR EASTERN AREAS THROUGH 12Z
TUESDAY. FOR MOST LOCATIONS NEAR LK SUPERIOR IT WILL BE THE POOR VSBY
INSTEAD OF THE SNOW AMOUNTS THAT WILL BE THE HIGHER IMPACT ISSUE.
FREQUENT WHITEOUT CONDITIONS ARE EXPECTED AS THE SMALL SNOW FLAKES
FALLING WITH EVEN 10-20 MPH WINDS WILL BE VERY PROFICIENT IN LEADING
TO LOWER VSBY.
BITTER COLD WIND CHILLS ARE THE OTHER ISSUE EARLY THIS WEEK. AS IT
APPEARED YDY...TIGHTEST PRESSURE GRADIENT IS PRESENT TO BEGIN THE
LONG TERM BUT IT GRADUALLY RELAXES BY TUESDAY MORNING AND EVEN
FURTHER BY WEDNESDAY MORNING. EXPECT MIN TEMPS MONDAY NIGHT TO FALL
LESS THAN 10 BLO OVER A MAJORITY OF WEST HALF OF UPR MICHIGAN WITH
WIND CHILL READINGS DOWN TO 25-30 BLO ZERO. POSSIBLE THAT WINDS MAY
NOT TECHNICALLY REACH CRITERIA /SUSTAINED AT 10 MPH/ BUT IT IS
CERTAINLY CLOSE ENOUGH TO ISSUE A HEADLINE. AFTER COORD WITH SHORT
TERM FORECASTER...DECIDED TO ISSUE CATCH ALL WINTER WEATHER ADVY
OVER WESTERN TIER OF CWA FOR LK EFFECT SNOW/POOR VSBY AND THE BITTER
COLD WIND CHILLS. THIS HEADLINE WILL RUN THROUGH MIDDAY TUESDAY.
ELSEWHERE OVER WEST HALF OF UPR MICHIGAN...GOING TO ISSUE WIND CHILL
ADVY THROUGH MIDDAY TUESDAY. FURTHER REFINEMENTS MAY BE NEEDED TO
HEADLINES AS WE GET INTO MONDAY/TUESDAY...BUT THIS WILL BE OUR
STARTING POINT.
WORKING INTO TUESDAY NIGHT AND WEDNESDAY CONDITIONS CHANGE A BIT.
MAIN CHANGE IS BLYR WINDS BACKING MORE WSW TUESDAY NIGHT AND H925
WINDS BACKING WESTERLY. CHANGE IN WIND WILL PUSH ONGOING LK EFFECT
AND CLOUDS OVER THE WEST FARTHER TO THE NORTH. LK EFFECT STAYS IN
PLACE MOSTLY OVER THE EAST...STILL FALLING MODERATE AT TIMES...AS
THE STATIONARY MESOLOW REMAINS PRIMARY FEATURE DRIVING THE SNOW
THERE. THINKING THAT WITH WEAK PRESSURE GRADIENT AND LOSS OF CLOUDS
SHOULD ALLOW FOR WINDS OVER INTERIOR TO BECOME CALM AND PRIME
RADIATIONAL COOLING TO DEVELOP. LOWERED MIN TEMPS TOWARD LOWEST
GUIDANCE NUMBERS AROUND 20 BLO ZERO. MAY EVEN SEE LOWER TEMPS AT THE
FAVORED COLD SPOTS...BUT WILL JUST TREND IN THE COLDER DIRECTION FOR
NOW. ONLY CONCERN IN MIN TEMP FCST IS POSSIBLE INCREASING CLOUDS
ALOFT AHEAD OF ANOTHER TROUGH THAT DROPS IN ON WEDNESDAY. THINK
THOSE MID CLOUDS WILL HOLD OFF LONG ENOUGH TO ALLOW TEMPS TO TANK ON
TUESDAY NIGHT.
AS UPPER TROUGH BEGINS TO LOSE GRIP OVER AREA ON WEDNESDAY...MODELS
SHOWING SHORTWAVE DIPPING FROM NORTHERN PLAINS ON WEDNESDAY NIGHT TO
ACROSS LOWER GREAT LAKES LATER THURSDAY. MAJORITY OF SYNOPTIC SNOW
FROM THE SYSTEM PROBABLY MISSES UPR MICHIGAN...PERHAPS JUST TO THE
SOUTH THOUGH ACROSS WI AND LOWER MICHIGAN. INDICATION IS THAT FLOW
WILL BE SPLIT AND THE SOUTHERN SHORTWAVE DRIVES THE MAIN SYSTEM TO
THE SOUTH...BUT THERE IS ALSO NORTHERN STREAM WAVE DROPPING ACROSS
UPR LAKES THURSDAY NIGHT INTO FRIDAY. THIS MAY KEEP AN INVERTED SFC
TROUGH WELL TO NORTHWEST OF MAIN SFC LOW WHICH COULD LEAD TO SCT
SNOW SHOWERS OVR UPR LAKES ENHANCED FURTHER BY ONSHORE FLOW OFF LK
SUPERIOR. CONSENSUS POPS LOOKED OKAY...BUT DID INCREASE THEM
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT NEAR LK SUPERIOR. BASED ON
MSLP AND H85 RH/TEMPS...LK EFFECT CONTINUES THROUGH FRIDAY AND
EVEN INTO SATURDAY OVER THE EASTERN CWA...THOUGH INCREASING LOW-MID
LEVEL RIDGING WILL LEAD TO INCREASINGLY HOSTILE CONDITIONS FOR THE
LK EFFECT.
HEIGHTS FURTHER FLATTEN OUT THROUGH NEXT WEEKEND LEADING TO WARMER
AIR SPILLING ACROSS NORTHERN PLAINS AND UPR LAKES. COULD BE WARM AIR
ADVECTION TYPE SYSTEM SNOW BUT GFS AND ECMWF DIFFER ON TRACK OF
SHORTWAVE AND SFC TROUGH TO ENHANCE THAT SNOW POTENTIAL /ECMWF
FARTHER NORTH WHILE GFS MOVES FOCUS ACROSS UPR MICHIGAN/ SO WILL NOT
ALTER THE SLIGHT CHANCES THAT CONSENSUS GAVE FOR POPS. AFTER A
BITTER COLD START TO THE WEEK...APPEARS THAT TEMPS TO END THE WEEK
INTO NEXT WEEKEND WILL SHOW WARMING TREND WITH READINGS CLOSE TO
NORMAL BY NEXT SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1246 PM EST SUN JAN 20 2013
NORTHWEST FLOW CONTINUES TO BRING LAKE EFFECT SNOW SHOWERS TO THE
TAF SITES...CHIEFLY CMX AND IWD. EXPECTATION IS THAT CIGS WILL
REMAIN FAIRLY STEADY AT MVFR THROUGH MUCH OF THE PERIOD FOR IWD AND
CMX. BLOWING SNOW SHOULD DIMINISH FOR THE MOST PART AT CMX AS WINDS
RELAX THIS AFTERNOON...BUT AN UPTICK IN LES INTENSITY THIS EVENING
WILL BRING VIS TO CONSISTENT LIFR LEVELS. MEANWHILE...BACKING WINDS
TO A MORE WESTERLY DIRECTION WILL KEEP THE MAJORITY OF LES ACTIVITY
JUST NORTH OF IWD.
FOR SAW...DO NOT EXPECT MUCH MORE THAN A FEW SNOW SHOWERS OFF AND ON
THROUGHOUT THE PERIOD. EXPECTING MAINLY BROKEN CLOUDS PUSHING UP TO
VFR CIGS...BUT THERE COULD BE EXTENDED PERIODS WHERE CLOUDS SCATTER
OUT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 PM EST SUN JAN 20 2013
NW WINDS OF 15-30KT WILL DOMINATE LAKE SUPERIOR TONIGHT THRU MON AS
INCREASINGLY COLDER ARCTIC AIR FLOWS OVER THE LAKE. ONLY EXCEPTION
WILL BE OVER THE FAR E WHERE LAND BREEZES OFF UPPER MI AND ONTARIO
MAY YIELD A SHARP SFC TROF OR MESOLOW. AS A RESULT...WINDS MAY SHIFT
TO A LIGHTER OFFSHORE DIRECTION EAST OF GRAND MARAIS TONIGHT WHILE
LAND BREEZE E TO NE WINDS PUSH OVER THE LAKE FROM ONTARIO INTO THE
AREA S OF CARIBOU ISLAND. SFC TROF/MESO LOW WILL MOVE S OR SE MON...
BRINGING STRONGER N OR NW WINDS BACK TO THAT AREA. HVY FREEZING
SPRAY WILL CONTINUE UNDER BITTER COLD AIR FLOWING INTO THE AREA.
EXPECT WINDS TO STAY IN THE 20 TO 30 KT RANGE THROUGH MIDDLE OF WEEK
THEN WINDS FINALLY RELAX AS HIGH PRESSURE BEGINS TO BUILD ACROSS REGION.
HEAVY FREEZING SPRAY WILL SUBSIDE...BUT NOT UNTIL WEDNESDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ001>003-
084.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR MIZ006-007-
085.
WIND CHILL ADVISORY FROM 1 AM EST /MIDNIGHT CST/ MONDAY TO 1 PM
EST /NOON CST/ TUESDAY FOR MIZ004-005-009>011.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ WEDNESDAY
FOR LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...TK
MARINE...ROLFSON/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1247 PM EST SUN JAN 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EST SUN JAN 20 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR
TROF DOMINATING MOST OF CNTRL AND ERN NAMERICA DOWNWIND OF RDG ALONG
THE W COAST. COLDEST AIRMASS OF THE SEASON HAS SURGED INTO THE UPR
LKS IN THE WAKE OF POTENT SHRTWV/SFC LO NOW MOVING INTO SE ONTARIO
ON THE HEELS OF NW WINDS GUSTS TO ARND 50KT AS OBSVD AT SOME OF THE
HIER MARINE PLATFORMS. BUT WITH PASSAGE OF MAIN PRES RISE CENTER
EARLY THIS MRNG...THE SHARP CYC NW FLOW IS BEGINNING TO WEAKEN. 00Z
H85/H5 TEMPS WERE AS LO AS -25C/-40C AT YPL. NO SURPRISE THIS
INCOMING AIRMASS IS ALSO QUITE DRY WITH PWATS AOB 0.10 INCH. BUT
PASSAGE OF THIS FRIGID AIRMASS OVER THE RELATIVE WARM WATERS OF LK
SUP HAS RESULTED IN PLENTY OF LK CLDS AND LES...PRIMARILY IN THE NW
WIND SN BELTS E OF MQT AND OVER THE W. EVEN THOUGH WINDS ARE
BEGINNING TO DIMINISH...LINGERING GUSTY WINDS ARE BLOWING THE FINE
SN FLAKES AND RESULTING IN SHAPRLY REDUCED VSBY AS LO AS 1/4SM AT
SOME PLACES. TWO MORE SHRTWVS ARE DIGGING SEWD THRU SCNTRL CANADA
IN THE NW FLOW ALF ON CYC SIDE OF SHARP UPR JET AXIS ON THE WRN
FLANK OF THE DEEP TROF. OF THESE TWO...THE ONE FARTHER W IN
ALBERTA/SASKATCHEWAN LOOKS THE MOST IMPRESSIVE WITH 100KT H5 JET MAX
SHOWN IN NE BRITISH COLUMBIA AT 00Z.
TODAY...AS DEEP SHRTWV/SFC LO TO THE E EXIT FARTHER AWAY...PRES
GRADIENT WL SLACKEN AND WINDS DIMINISH. BUT LES WL CONTINUE MAINLY
IN THE NW WIND SN BELTS WITH ARRIVAL OF COLDER AIR/H85 TEMPS FALLING
TOWARD -25C OVER THE W BY 00Z DESPITE SOME MID LVL DRYING/
STRENGTHENING INVRN ARND 5K FT OVER THE W BUT AS HI AS 7-8FT OVER
THE E. THE LO H85 TEMPS WL LIMIT SN GROWTH AND RESULT IN FINE SN
FLAKES. THIS EFFECT SHOULD BE MAGNIFIED WITH SHORTER FETCH/LESS
MOISTENING OVER THE W BUT MITIGATED A BIT OVER THE E WITH LONGER
FETCH LENGTH. ALTHOUGH WINDS WL DIMINISH... SOME BLSN WL CONT
ESPECIALLY IN OPEN AREAS NEAR LK SUP AS THE FINE FLAKES WL BE BLOWN
EFFICIENTLY. WITH ARRIVAL OF FIRST OF 2 SHRTWVS UPSTREAM/
ACCOMPANYING DPVA...LLVL FLOW IS PROGGED TO BACK A BIT THIS
AFTN...WITH SOME MID LVL MOISTENING/INCRSG CONVECTIVE DEPTH SHOWING
UP AGAIN BY LATE THIS AFTN OVER THE W. EXPECT LTL DIURNAL RISE IN
TEMP WITH SURGE OF LLVL COLD AIR.
TONIGHT...2ND SHRTWV UPSTREAM/ACCOMPANYING DPVA ARE PROGGED TO
ARRIVE...WITH WEAKENING AND RISING INVRN/DEEPENING MSTR. AS CYC WNW
FLOW SHARPENS AS WELL...EXPECT INCRSG INTENSITY OF SHSN/BLSN. BULK
OF NUMERICAL MODELS SHOW SHARPEST LLVL CNVGC NEAR ONTONAGON COUNTY
AND IN AREAS NEAR LK SUP E OF MUNISING DUE TO LAND BREEZE EFFECTS
AND PERSISTENT LK INDUCED TROFFING OVER ERN LK SUP. WL FOCUS HIER
POPS/SN AMOUNTS IN THESE AREAS...ESPECIALLY OVER THE E WHERE LONGER
FETCH/MORE LK WARMING/MOISTENING WL IMPROVE SN/WATER RATIOS.
ALTHOUGH THE HEAVIER SHSN MIGHT DRIFT OUT OF NRN SCHOOLCRAFT COUNTY
LATE TNGT WITH BACKING FLOW...OPTED TO KEEP GOING WARNING FOR THE
ERN CWA GOING THRU 12Z MON. EXPECTED SN FALL OVER ONTONAGON COUNTY
LOOKS AT 4 TO 6 INCHES. SINCE THIS IS A MARGINAL ADVY AMOUNT AND
THERE IS LIKELY TO BE A BREAK IN THE SHSN/BLSN INTENSITY TODAY FOR
AT LEAST A TIME...DECIDED NOT TO EXTEND THE HEADLINE FOR ONTONAGON
COUNTY INTO TNGT. ANOTHER CONCERN WL BE POTENTIAL FOR AT LEAST ADVY
THRESHOLD WIND CHILLS AS THIS SHRTWV DRAGS H85 TEMPS AS LO AS -30C
TO IWD BY 12Z MON. SINCE THE H925 FLOW WL BE 280-290 DEGREES...CAD
WL ALLOW FOR MORE MIXING OF THE 20-25KT H925 WINDS...AND NEAR SFC
FLOW WL BACK FURTHER AND ALLOW FOR ADVECTION OF MORE UNMODIFIED
ARCTIC AIR DUE TO LAND BREEZE COMPONENT WITHIN BITTERLY COLD
AIRMASS...EXPECT WIND CHILLS TO FALL INTO THE ADVY RANGE AT LEAST
NEAR THE WI BORDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 512 AM EST SUN JAN 20 2013
GOING INTO MON...A TROUGH WILL ROTATE THROUGH THE CWA DURING THE
DAY. MODELS SHOW THAT DYNAMICS WITH THE TROUGH WILL NOT BRING MUCH
IF ANYTHING IN THE WAY OF SYNOPTIC SNOW...BUT WILL ACT TO INTENSIFY
NW WIND LES AND CAUSE THE SFC TROUGH OVER ERN LAKE SUPERIOR TO CLOSE
OFF. HIGHER RES MODELS SUGGEST THAT THE LOW WILL FOCUS LES BANDS
INTO A MORE DOMINANT BAND MOVING ONSHORE ACROSS ALGER AND/OR LUCE
COUNTIES...DEPENDING ON MESOSCALE CONDITIONS THAT WILL HAVE TO BE
DETERMINED MUCH CLOSER TO THE TIME OF OCCURRENCE. GIVEN 725MB
INVERSION TOP TEMPERATURES AROUND -35C AND LAKE WATER TEMPS AROUND
2C...LAKE INDUCED EQUILIBRIUM LEVELS OF 12-15KFT SHOULD BE REALIZED
OVER ERN LAKE SUPERIOR. THE DGZ WILL BE VERY LOW...SO SLR/S WILL NOT
BE AS HIGH AS THE COULD BE IN WARMER CONDITIONS. EVEN SO...IF A
HEAVIER BAND DOES FORM...SNOWFALL RATES COULD APPROACH AN INCH AN
HOUR UNDER THE BAND. OVER WRN LAKE SUPERIOR...INVERSION TOPS WILL
NOT BE AS HIGH FARTHER AWAY FROM THE TROUGH.
THE REALLY COLD AIR /850MB TEMPS -27C TO -30C/ BEGINS TO PUSH E LATE
TUE...SO THE COLDEST SFC TEMPS OF THE SEASON /AREA WIDE/ WILL BE MON
THROUGH TUE NIGHT...WITH A CONCERN OF WIND CHILLS. WIND CHILL
ADVISORY CRITERIA IS WIND CHILLS LESS THAN -25F WITH WINDS AT LEAST
10MPH...WHICH SHOULD BE REACHED OVER PORTIONS OF THE WRN HALF OF THE
U.P. SUN NIGHT THROUGH MON AND AGAIN TUE NIGHT /MON NIGHT THE WINDS
ARE FORECAST TO BE BELOW THE 10MPH CRITERIA/. WARNING CRITERIA OF
-35F SHOULD BE HARDER TO ACHIEVE...WITH THE BEST CHANCE OF
OCCURRENCE SUN NIGHT INTO MON MORNING AND MON NIGHT INTO TUE MORNING
OVER THE FAR W. COLDEST ACTUAL TEMPS LOOK TO BE MON NIGHT OVER
PORTIONS OF GOGEBIC AND IRON COUNTIES WITH A LOW FORECAST OF -20F.
DECIDED TO ISSUE WIND CHILL ADVISORY FOR THE FAR W MON.
LOW LEVEL TEMPS GENERALLY WARM SLOWLY TO -15C TO -20C BY SAT WITH NW
LOW LEVEL WINDS THROUGH MOST OF THE PERIOD. A SHORTWAVE LOOKS TO
MOVE THROUGH ON WED...SO LES SHOULD BE INTENSIFIED THEN...BUT
OTHERWISE MORE RIDGING WORKS INTO THE AREA THROUGH THE REST OF THE
PERIOD...MAKING FOR MORE HOSTILE CONDITIONS FOR LES THU THROUGH SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1246 PM EST SUN JAN 20 2013
NORTHWEST FLOW CONTINUES TO BRING LAKE EFFECT SNOW SHOWERS TO THE
TAF SITES...CHIEFLY CMX AND IWD. EXPECTATION IS THAT CIGS WILL
REMAIN FAIRLY STEADY AT MVFR THROUGH MUCH OF THE PERIOD FOR IWD AND
CMX. BLOWING SNOW SHOULD DIMINISH FOR THE MOST PART AT CMX AS WINDS
RELAX THIS AFTERNOON...BUT AN UPTICK IN LES INTENSITY THIS EVENING
WILL BRING VIS TO CONSISTENT LIFR LEVELS. MEANWHILE...BACKING WINDS
TO A MORE WESTERLY DIRECTION WILL KEEP THE MAJORITY OF LES ACTIVITY
JUST NORTH OF IWD.
FOR SAW...DO NOT EXPECT MUCH MORE THAN A FEW SNOW SHOWERS OFF AND ON
THROUGHOUT THE PERIOD. EXPECTING MAINLY BROKEN CLOUDS PUSHING UP TO
VFR CIGS...BUT THERE COULD BE EXTENDED PERIODS WHERE CLOUDS SCATTER
OUT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EST SUN JAN 20 2013
EXPECT NW GALES TO 40 KTS THIS MORNING OVER MAINLY THE E HALF TO
DIMINISH BY EARLY AFTERNOON AS LO PRES OVER SE CANADA CONTINUES TO
MOVE FARTHER TO THE E. BUT WITH ARCTIC AIR DOMINATING INTO MID
WEEK...THERE WILL BE PERIODS OF HEAVY FREEZING SPRAY EVEN THOUGH THE
NW WINDS WILL BE MAINLY IN THE 15 TO 30 KT RANGE. THE ARRIVAL OF A
WEAKER PRES GRADIENT/LIGHTER WINDS BY LATER WED/THU WILL FINALLY END
THE THREAT OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST MONDAY FOR MIZ006-007-
085.
WIND CHILL ADVISORY FROM 3 AM TO 6 PM CST MONDAY FOR MIZ009.
WIND CHILL ADVISORY FROM 4 AM EST /3 AM CST/ TO 1 PM EST /NOON
CST/ MONDAY FOR MIZ002-010.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST TUESDAY FOR
LSZ245>251-265>267.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ245>251-
265>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ MONDAY
FOR LSZ162-240>244-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...TK
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
635 AM EST SUN JAN 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EST SUN JAN 20 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR
TROF DOMINATING MOST OF CNTRL AND ERN NAMERICA DOWNWIND OF RDG ALONG
THE W COAST. COLDEST AIRMASS OF THE SEASON HAS SURGED INTO THE UPR
LKS IN THE WAKE OF POTENT SHRTWV/SFC LO NOW MOVING INTO SE ONTARIO
ON THE HEELS OF NW WINDS GUSTS TO ARND 50KT AS OBSVD AT SOME OF THE
HIER MARINE PLATFORMS. BUT WITH PASSAGE OF MAIN PRES RISE CENTER
EARLY THIS MRNG...THE SHARP CYC NW FLOW IS BEGINNING TO WEAKEN. 00Z
H85/H5 TEMPS WERE AS LO AS -25C/-40C AT YPL. NO SURPRISE THIS
INCOMING AIRMASS IS ALSO QUITE DRY WITH PWATS AOB 0.10 INCH. BUT
PASSAGE OF THIS FRIGID AIRMASS OVER THE RELATIVE WARM WATERS OF LK
SUP HAS RESULTED IN PLENTY OF LK CLDS AND LES...PRIMARILY IN THE NW
WIND SN BELTS E OF MQT AND OVER THE W. EVEN THOUGH WINDS ARE
BEGINNING TO DIMINISH...LINGERING GUSTY WINDS ARE BLOWING THE FINE
SN FLAKES AND RESULTING IN SHAPRLY REDUCED VSBY AS LO AS 1/4SM AT
SOME PLACES. TWO MORE SHRTWVS ARE DIGGING SEWD THRU SCNTRL CANADA
IN THE NW FLOW ALF ON CYC SIDE OF SHARP UPR JET AXIS ON THE WRN
FLANK OF THE DEEP TROF. OF THESE TWO...THE ONE FARTHER W IN
ALBERTA/SASKATCHEWAN LOOKS THE MOST IMPRESSIVE WITH 100KT H5 JET MAX
SHOWN IN NE BRITISH COLUMBIA AT 00Z.
TODAY...AS DEEP SHRTWV/SFC LO TO THE E EXIT FARTHER AWAY...PRES
GRADIENT WL SLACKEN AND WINDS DIMINISH. BUT LES WL CONTINUE MAINLY
IN THE NW WIND SN BELTS WITH ARRIVAL OF COLDER AIR/H85 TEMPS FALLING
TOWARD -25C OVER THE W BY 00Z DESPITE SOME MID LVL DRYING/
STRENGTHENING INVRN ARND 5K FT OVER THE W BUT AS HI AS 7-8FT OVER
THE E. THE LO H85 TEMPS WL LIMIT SN GROWTH AND RESULT IN FINE SN
FLAKES. THIS EFFECT SHOULD BE MAGNIFIED WITH SHORTER FETCH/LESS
MOISTENING OVER THE W BUT MITIGATED A BIT OVER THE E WITH LONGER
FETCH LENGTH. ALTHOUGH WINDS WL DIMINISH... SOME BLSN WL CONT
ESPECIALLY IN OPEN AREAS NEAR LK SUP AS THE FINE FLAKES WL BE BLOWN
EFFICIENTLY. WITH ARRIVAL OF FIRST OF 2 SHRTWVS UPSTREAM/
ACCOMPANYING DPVA...LLVL FLOW IS PROGGED TO BACK A BIT THIS
AFTN...WITH SOME MID LVL MOISTENING/INCRSG CONVECTIVE DEPTH SHOWING
UP AGAIN BY LATE THIS AFTN OVER THE W. EXPECT LTL DIURNAL RISE IN
TEMP WITH SURGE OF LLVL COLD AIR.
TONIGHT...2ND SHRTWV UPSTREAM/ACCOMPANYING DPVA ARE PROGGED TO
ARRIVE...WITH WEAKENING AND RISING INVRN/DEEPENING MSTR. AS CYC WNW
FLOW SHARPENS AS WELL...EXPECT INCRSG INTENSITY OF SHSN/BLSN. BULK
OF NUMERICAL MODELS SHOW SHARPEST LLVL CNVGC NEAR ONTONAGON COUNTY
AND IN AREAS NEAR LK SUP E OF MUNISING DUE TO LAND BREEZE EFFECTS
AND PERSISTENT LK INDUCED TROFFING OVER ERN LK SUP. WL FOCUS HIER
POPS/SN AMOUNTS IN THESE AREAS...ESPECIALLY OVER THE E WHERE LONGER
FETCH/MORE LK WARMING/MOISTENING WL IMPROVE SN/WATER RATIOS.
ALTHOUGH THE HEAVIER SHSN MIGHT DRIFT OUT OF NRN SCHOOLCRAFT COUNTY
LATE TNGT WITH BACKING FLOW...OPTED TO KEEP GOING WARNING FOR THE
ERN CWA GOING THRU 12Z MON. EXPECTED SN FALL OVER ONTONAGON COUNTY
LOOKS AT 4 TO 6 INCHES. SINCE THIS IS A MARGINAL ADVY AMOUNT AND
THERE IS LIKELY TO BE A BREAK IN THE SHSN/BLSN INTENSITY TODAY FOR
AT LEAST A TIME...DECIDED NOT TO EXTEND THE HEADLINE FOR ONTONAGON
COUNTY INTO TNGT. ANOTHER CONCERN WL BE POTENTIAL FOR AT LEAST ADVY
THRESHOLD WIND CHILLS AS THIS SHRTWV DRAGS H85 TEMPS AS LO AS -30C
TO IWD BY 12Z MON. SINCE THE H925 FLOW WL BE 280-290 DEGREES...CAD
WL ALLOW FOR MORE MIXING OF THE 20-25KT H925 WINDS...AND NEAR SFC
FLOW WL BACK FURTHER AND ALLOW FOR ADVECTION OF MORE UNMODIFIED
ARCTIC AIR DUE TO LAND BREEZE COMPONENT WITHIN BITTERLY COLD
AIRMASS...EXPECT WIND CHILLS TO FALL INTO THE ADVY RANGE AT LEAST
NEAR THE WI BORDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 512 AM EST SUN JAN 20 2013
GOING INTO MON...A TROUGH WILL ROTATE THROUGH THE CWA DURING THE
DAY. MODELS SHOW THAT DYNAMICS WITH THE TROUGH WILL NOT BRING MUCH
IF ANYTHING IN THE WAY OF SYNOPTIC SNOW...BUT WILL ACT TO INTENSIFY
NW WIND LES AND CAUSE THE SFC TROUGH OVER ERN LAKE SUPERIOR TO CLOSE
OFF. HIGHER RES MODELS SUGGEST THAT THE LOW WILL FOCUS LES BANDS
INTO A MORE DOMINANT BAND MOVING ONSHORE ACROSS ALGER AND/OR LUCE
COUNTIES...DEPENDING ON MESOSCALE CONDITIONS THAT WILL HAVE TO BE
DETERMINED MUCH CLOSER TO THE TIME OF OCCURRENCE. GIVEN 725MB
INVERSION TOP TEMPERATURES AROUND -35C AND LAKE WATER TEMPS AROUND
2C...LAKE INDUCED EQUILIBRIUM LEVELS OF 12-15KFT SHOULD BE REALIZED
OVER ERN LAKE SUPERIOR. THE DGZ WILL BE VERY LOW...SO SLR/S WILL NOT
BE AS HIGH AS THE COULD BE IN WARMER CONDITIONS. EVEN SO...IF A
HEAVIER BAND DOES FORM...SNOWFALL RATES COULD APPROACH AN INCH AN
HOUR UNDER THE BAND. OVER WRN LAKE SUPERIOR...INVERSION TOPS WILL
NOT BE AS HIGH FARTHER AWAY FROM THE TROUGH.
THE REALLY COLD AIR /850MB TEMPS -27C TO -30C/ BEGINS TO PUSH E LATE
TUE...SO THE COLDEST SFC TEMPS OF THE SEASON /AREA WIDE/ WILL BE MON
THROUGH TUE NIGHT...WITH A CONCERN OF WIND CHILLS. WIND CHILL
ADVISORY CRITERIA IS WIND CHILLS LESS THAN -25F WITH WINDS AT LEAST
10MPH...WHICH SHOULD BE REACHED OVER PORTIONS OF THE WRN HALF OF THE
U.P. SUN NIGHT THROUGH MON AND AGAIN TUE NIGHT /MON NIGHT THE WINDS
ARE FORECAST TO BE BELOW THE 10MPH CRITERIA/. WARNING CRITERIA OF
-35F SHOULD BE HARDER TO ACHIEVE...WITH THE BEST CHANCE OF
OCCURRENCE SUN NIGHT INTO MON MORNING AND MON NIGHT INTO TUE MORNING
OVER THE FAR W. COLDEST ACTUAL TEMPS LOOK TO BE MON NIGHT OVER
PORTIONS OF GOGEBIC AND IRON COUNTIES WITH A LOW FORECAST OF -20F.
DECIDED TO ISSUE WIND CHILL ADVISORY FOR THE FAR W MON.
LOW LEVEL TEMPS GENERALLY WARM SLOWLY TO -15C TO -20C BY SAT WITH NW
LOW LEVEL WINDS THROUGH MOST OF THE PERIOD. A SHORTWAVE LOOKS TO
MOVE THROUGH ON WED...SO LES SHOULD BE INTENSIFIED THEN...BUT
OTHERWISE MORE RIDGING WORKS INTO THE AREA THROUGH THE REST OF THE
PERIOD...MAKING FOR MORE HOSTILE CONDITIONS FOR LES THU THROUGH SAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 634 AM EST SUN JAN 20 2013
EXPECT PREDOMINANT IFR TO LIFR CONDITIONS TO DOMINATE CMX THIS FCST
PERIOD WITH GUSTY NW FLOW OF ARCTIC AIR BRINGING PERSISTENT SHSN/
BLSN. ALTHOUGH IFR WX WL PREDOMINATE AT IWD THIS MRNG...EXPECT
IMPROVEMENT AS THE LLVL FLOW SLOWLY BACKS TOWARD THE W AND BRINGS
DRIER AIR/PREDOMINANT MVFR CONDITIONS. ALTHOUGH THERE MAY BE LINGERING
MVFR WX AT SAW THIS MRNG...VFR CONDITIONS SHOULD DOMINATE THERE BY
THIS AFTN WITH DOWNSLOPING FLOW AND DRY ADVECTION.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EST SUN JAN 20 2013
EXPECT NW GALES TO 40 KTS THIS MORNING OVER MAINLY THE E HALF TO
DIMINISH BY EARLY AFTERNOON AS LO PRES OVER SE CANADA CONTINUES TO
MOVE FARTHER TO THE E. BUT WITH ARCTIC AIR DOMINATING INTO MID
WEEK...THERE WILL BE PERIODS OF HEAVY FREEZING SPRAY EVEN THOUGH THE
NW WINDS WILL BE MAINLY IN THE 15 TO 30 KT RANGE. THE ARRIVAL OF A
WEAKER PRES GRADIENT/LIGHTER WINDS BY LATER WED/THU WILL FINALLY END
THE THREAT OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST MONDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR MIZ001>003-009.
WIND CHILL ADVISORY FROM 3 AM TO 6 PM CST MONDAY FOR MIZ009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ005.
WIND CHILL ADVISORY FROM 4 AM EST /3 AM CST/ TO 1 PM EST /NOON
CST/ MONDAY FOR MIZ002-010.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST TUESDAY FOR
LSZ245>251-265>267.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ245>251-
265>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ MONDAY
FOR LSZ162-240>244-263-264.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ244-264.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
240>243-263.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING UNTIL 9 AM EST THIS MORNING FOR
LMZ248-250.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ221-248-250.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EST SUN JAN 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EST SUN JAN 20 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR
TROF DOMINATING MOST OF CNTRL AND ERN NAMERICA DOWNWIND OF RDG ALONG
THE W COAST. COLDEST AIRMASS OF THE SEASON HAS SURGED INTO THE UPR
LKS IN THE WAKE OF POTENT SHRTWV/SFC LO NOW MOVING INTO SE ONTARIO
ON THE HEELS OF NW WINDS GUSTS TO ARND 50KT AS OBSVD AT SOME OF THE
HIER MARINE PLATFORMS. BUT WITH PASSAGE OF MAIN PRES RISE CENTER
EARLY THIS MRNG...THE SHARP CYC NW FLOW IS BEGINNING TO WEAKEN. 00Z
H85/H5 TEMPS WERE AS LO AS -25C/-40C AT YPL. NO SURPRISE THIS
INCOMING AIRMASS IS ALSO QUITE DRY WITH PWATS AOB 0.10 INCH. BUT
PASSAGE OF THIS FRIGID AIRMASS OVER THE RELATIVE WARM WATERS OF LK
SUP HAS RESULTED IN PLENTY OF LK CLDS AND LES...PRIMARILY IN THE NW
WIND SN BELTS E OF MQT AND OVER THE W. EVEN THOUGH WINDS ARE
BEGINNING TO DIMINISH...LINGERING GUSTY WINDS ARE BLOWING THE FINE
SN FLAKES AND RESULTING IN SHAPRLY REDUCED VSBY AS LO AS 1/4SM AT
SOME PLACES. TWO MORE SHRTWVS ARE DIGGING SEWD THRU SCNTRL CANADA
IN THE NW FLOW ALF ON CYC SIDE OF SHARP UPR JET AXIS ON THE WRN
FLANK OF THE DEEP TROF. OF THESE TWO...THE ONE FARTHER W IN
ALBERTA/SASKATCHEWAN LOOKS THE MOST IMPRESSIVE WITH 100KT H5 JET MAX
SHOWN IN NE BRITISH COLUMBIA AT 00Z.
TODAY...AS DEEP SHRTWV/SFC LO TO THE E EXIT FARTHER AWAY...PRES
GRADIENT WL SLACKEN AND WINDS DIMINISH. BUT LES WL CONTINUE MAINLY
IN THE NW WIND SN BELTS WITH ARRIVAL OF COLDER AIR/H85 TEMPS FALLING
TOWARD -25C OVER THE W BY 00Z DESPITE SOME MID LVL DRYING/
STRENGTHENING INVRN ARND 5K FT OVER THE W BUT AS HI AS 7-8FT OVER
THE E. THE LO H85 TEMPS WL LIMIT SN GROWTH AND RESULT IN FINE SN
FLAKES. THIS EFFECT SHOULD BE MAGNIFIED WITH SHORTER FETCH/LESS
MOISTENING OVER THE W BUT MITIGATED A BIT OVER THE E WITH LONGER
FETCH LENGTH. ALTHOUGH WINDS WL DIMINISH... SOME BLSN WL CONT
ESPECIALLY IN OPEN AREAS NEAR LK SUP AS THE FINE FLAKES WL BE BLOWN
EFFICIENTLY. WITH ARRIVAL OF FIRST OF 2 SHRTWVS UPSTREAM/
ACCOMPANYING DPVA...LLVL FLOW IS PROGGED TO BACK A BIT THIS
AFTN...WITH SOME MID LVL MOISTENING/INCRSG CONVECTIVE DEPTH SHOWING
UP AGAIN BY LATE THIS AFTN OVER THE W. EXPECT LTL DIURNAL RISE IN
TEMP WITH SURGE OF LLVL COLD AIR.
TONIGHT...2ND SHRTWV UPSTREAM/ACCOMPANYING DPVA ARE PROGGED TO
ARRIVE...WITH WEAKENING AND RISING INVRN/DEEPENING MSTR. AS CYC WNW
FLOW SHARPENS AS WELL...EXPECT INCRSG INTENSITY OF SHSN/BLSN. BULK
OF NUMERICAL MODELS SHOW SHARPEST LLVL CNVGC NEAR ONTONAGON COUNTY
AND IN AREAS NEAR LK SUP E OF MUNISING DUE TO LAND BREEZE EFFECTS
AND PERSISTENT LK INDUCED TROFFING OVER ERN LK SUP. WL FOCUS HIER
POPS/SN AMOUNTS IN THESE AREAS...ESPECIALLY OVER THE E WHERE LONGER
FETCH/MORE LK WARMING/MOISTENING WL IMPROVE SN/WATER RATIOS.
ALTHOUGH THE HEAVIER SHSN MIGHT DRIFT OUT OF NRN SCHOOLCRAFT COUNTY
LATE TNGT WITH BACKING FLOW...OPTED TO KEEP GOING WARNING FOR THE
ERN CWA GOING THRU 12Z MON. EXPECTED SN FALL OVER ONTONAGON COUNTY
LOOKS AT 4 TO 6 INCHES. SINCE THIS IS A MARGINAL ADVY AMOUNT AND
THERE IS LIKELY TO BE A BREAK IN THE SHSN/BLSN INTENSITY TODAY FOR
AT LEAST A TIME...DECIDED NOT TO EXTEND THE HEADLINE FOR ONTONAGON
COUNTY INTO TNGT. ANOTHER CONCERN WL BE POTENTIAL FOR AT LEAST ADVY
THRESHOLD WIND CHILLS AS THIS SHRTWV DRAGS H85 TEMPS AS LO AS -30C
TO IWD BY 12Z MON. SINCE THE H925 FLOW WL BE 280-290 DEGREES...CAD
WL ALLOW FOR MORE MIXING OF THE 20-25KT H925 WINDS...AND NEAR SFC
FLOW WL BACK FURTHER AND ALLOW FOR ADVECTION OF MORE UNMODIFIED
ARCTIC AIR DUE TO LAND BREEZE COMPONENT WITHIN BITTERLY COLD
AIRMASS...EXPECT WIND CHILLS TO FALL INTO THE ADVY RANGE AT LEAST
NEAR THE WI BORDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 512 AM EST SUN JAN 20 2013
GOING INTO MON...A TROUGH WILL ROTATE THROUGH THE CWA DURING THE
DAY. MODELS SHOW THAT DYNAMICS WITH THE TROUGH WILL NOT BRING MUCH
IF ANYTHING IN THE WAY OF SYNOPTIC SNOW...BUT WILL ACT TO INTENSIFY
NW WIND LES AND CAUSE THE SFC TROUGH OVER ERN LAKE SUPERIOR TO CLOSE
OFF. HIGHER RES MODELS SUGGEST THAT THE LOW WILL FOCUS LES BANDS
INTO A MORE DOMINANT BAND MOVING ONSHORE ACROSS ALGER AND/OR LUCE
COUNTIES...DEPENDING ON MESOSCALE CONDITIONS THAT WILL HAVE TO BE
DETERMINED MUCH CLOSER TO THE TIME OF OCCURRENCE. GIVEN 725MB
INVERSION TOP TEMPERATURES AROUND -35C AND LAKE WATER TEMPS AROUND
2C...LAKE INDUCED EQUILIBRIUM LEVELS OF 12-15KFT SHOULD BE REALIZED
OVER ERN LAKE SUPERIOR. THE DGZ WILL BE VERY LOW...SO SLR/S WILL NOT
BE AS HIGH AS THE COULD BE IN WARMER CONDITIONS. EVEN SO...IF A
HEAVIER BAND DOES FORM...SNOWFALL RATES COULD APPROACH AN INCH AN
HOUR UNDER THE BAND. OVER WRN LAKE SUPERIOR...INVERSION TOPS WILL
NOT BE AS HIGH FARTHER AWAY FROM THE TROUGH.
THE REALLY COLD AIR /850MB TEMPS -27C TO -30C/ BEGINS TO PUSH E LATE
TUE...SO THE COLDEST SFC TEMPS OF THE SEASON /AREA WIDE/ WILL BE MON
THROUGH TUE NIGHT...WITH A CONCERN OF WIND CHILLS. WIND CHILL
ADVISORY CRITERIA IS WIND CHILLS LESS THAN -25F WITH WINDS AT LEAST
10MPH...WHICH SHOULD BE REACHED OVER PORTIONS OF THE WRN HALF OF THE
U.P. SUN NIGHT THROUGH MON AND AGAIN TUE NIGHT /MON NIGHT THE WINDS
ARE FORECAST TO BE BELOW THE 10MPH CRITERIA/. WARNING CRITERIA OF
-35F SHOULD BE HARDER TO ACHIEVE...WITH THE BEST CHANCE OF
OCCURRENCE SUN NIGHT INTO MON MORNING AND MON NIGHT INTO TUE MORNING
OVER THE FAR W. COLDEST ACTUAL TEMPS LOOK TO BE MON NIGHT OVER
PORTIONS OF GOGEBIC AND IRON COUNTIES WITH A LOW FORECAST OF -20F.
DECIDED TO ISSUE WIND CHILL ADVISORY FOR THE FAR W MON.
LOW LEVEL TEMPS GENERALLY WARM SLOWLY TO -15C TO -20C BY SAT WITH NW
LOW LEVEL WINDS THROUGH MOST OF THE PERIOD. A SHORTWAVE LOOKS TO
MOVE THROUGH ON WED...SO LES SHOULD BE INTENSIFIED THEN...BUT
OTHERWISE MORE RIDGING WORKS INTO THE AREA THROUGH THE REST OF THE
PERIOD...MAKING FOR MORE HOSTILE CONDITIONS FOR LES THU THROUGH SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1209 AM EST SUN JAN 20 2013
GUSTY NW WINDS WILL CONTINUE INTO THE EARLY OVERNIGHT AT ALL TAF
SITES IN THE WAKE OF A CLIPPER SYSTEM AND ASSOCIATED COLD FRONT.
EXPECT IFR/LIFR CONDITIONS AT ALL SITES IN LAKE EFFECT SNOW AND
BLOWING SNOW INTO THE EARLY OVERNIGHT. CONDITIONS SHOULD
SLOWLY IMPROVE LATE TONIGHT INTO SUNDAY MORNING AS THE WIND DIES
DOWN. CONDITIONS AT KSAW SHOULD RETURN TO VFR SUNDAY AFTERNOON AS
WINDS BACK WNW AND LAKE CLOUDS PUSH EAST. CONDITIONS AT KIWD AND
KCMX WILL AGAIN LOWER DOWN TO IFR/LIFR LATE SUNDAY AFTERNOON AND
EVENING AS CONDITIONS OVER LAKE SUPERIOR BECOME MORE UNSTABLE AND
MOISTURE DEEPENS ALLOWING FOR MORE INTENSE LAKE EFFECT SNOW BANDS TO
FORM.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EST SUN JAN 20 2013
EXPECT NW GALES TO 40 KTS THIS MORNING OVER MAINLY THE E HALF TO
DIMINISH BY EARLY AFTERNOON AS LO PRES OVER SE CANADA CONTINUES TO
MOVE FARTHER TO THE E. BUT WITH ARCTIC AIR DOMINATING INTO MID
WEEK...THERE WILL BE PERIODS OF HEAVY FREEZING SPRAY EVEN THOUGH THE
NW WINDS WILL BE MAINLY IN THE 15 TO 30 KT RANGE. THE ARRIVAL OF A
WEAKER PRES GRADIENT/LIGHTER WINDS BY LATER WED/THU WILL FINALLY END
THE THREAT OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST MONDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR MIZ001>003-009.
WIND CHILL ADVISORY FROM 3 AM TO 6 PM CST MONDAY FOR MIZ009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ005.
WIND CHILL ADVISORY FROM 4 AM EST /3 AM CST/ TO 1 PM EST /NOON
CST/ MONDAY FOR MIZ002-010.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST TUESDAY FOR
LSZ245>251-265>267.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ245>251-
265>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ MONDAY
FOR LSZ162-240>244-263-264.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ244-264.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
240>243-263.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING UNTIL 9 AM EST THIS MORNING FOR
LMZ248-250.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ221-248-250.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1132 PM CST SAT JAN 19 2013
.AVIATION...06Z TAFS.
A WEAK SFC TROF OVER NORTHERN MN IS THE DIVIDING LINE BETWEEN VFR
AND MVFR. INL IS VFR BEING ON THE NORTH SIDE OF THE TROF WHILE THE
OTHER SITES HAVE MVFR CIGS. DLH IS VFR DUE TO ITS PROXIMITY TO
LAKE SUPERIOR WHERE DRY AIR HAS ERODED THE MVFR CIGS. EXPECT AN
IMPROVEMENT AT MVFR SITES TO VFR BY 12Z. ANOTHER BATCH OF LOW END
VFR CLOUDS ARRIVES AROUND 19Z IN ADVANCE OF THE SHORT WAVE
DROPPING THROUGH THE AREA.
&&
.PREV DISCUSSION... /ISSUED 822 PM CST SAT JAN 19 2013/
UPDATE...PUSHED THE WIND ADVISORY START TIME TO NOW AS IT WAS NOT
DUE TO START UNTIL 03Z. GNA HAS GUSTED TO 57 MPH IN THE LAST HALF
HOUR. REST OF THE FORECAST ON TRACK.
PREV DISCUSSION... /ISSUED 631 PM CST SAT JAN 19 2013/
UPDATE...DROPPED THE WIND ADVISORY FROM THE SOUTHERN MN ZONES.
GUSTY WINDS STILL EXPECTED UNTIL NEAR 06Z. WITH THE EXPECTED
CLEARING TREND...DROP MIN TEMPS A BIT. NO OTHER CHANGES TO
HEADLINES.
PREV DISCUSSION... /ISSUED 525 PM CST SAT JAN 19 2013/
AVIATION...00Z TAFS.
TIGHT PRESSURE GRADIENT OVER THE FA AT THE BEGINNING OF THE
FORECAST...BUT WILL LOOSEN ITS GRIP THROUGH THE EVENING AND GUSTY
WINDS WILL DIMINISH AROUND 06Z. MVFR WITH AREAS OF IFR WILL
IMPROVE TO VFR ABOUT THE SAME TIME THE GUSTY WINDS DIMINISH.
EXPECT A MID DECK OF CLOUDS AFTER 18Z SUNDAY AHEAD OF A SHORT WAVE
TROF MOVING THROUGH THE FA.
PREV DISCUSSION... /ISSUED 336 PM CST SAT JAN 19 2013/
SHORT TERM.../NOW - SUNDAY NIGHT/
THE MAIN CHALLENGES FOR THIS FORECAST INCLUDE 1) THE THREAT OF
STRONG WINDS ACROSS THE NORTHLAND THROUGH TONIGHT IN THE WAKE OF A
STRONG COLD FRONT...2) THE THREAT OF LAKE EFFECT SNOW FOR THE
GOGEBIC RANGE AND 3) THE THREAT OF HAZARDOUS WIND CHILL VALUES
TONIGHT AND TOMORROW MORNING. THE MODELS ARE IN REASONABLE
AGREEMENT...SO LEANED ON A BLEND. THE LATEST HIGH RESOLUTIONS
MODELS INDICATE STRONG WIND GUSTS ALONG THE NORTH SHORE
TONIGHT...SO ISSUED A WIND ADVISORY FOR THE NORTH SHORE THAT IS
SEPARATE FROM THE WIND ADVISORY FOR PARTS OF EAST CENTRAL
MINNESOTA AND NORTHWESTERN WISCONSIN.
AT 2130Z...THERE WAS A STRONG CLIPPER SYSTEM CENTERED OVER UPPER
PENINSULA MICHIGAN. THE NORTHLAND HAD STRONG W TO NW WINDS...WHICH
WERE GENERALLY STRENGTHENING IN THE WAKE OF THE CLIPPER. THE
NORTHLAND HAD CLOUDY SKIES. TEMPERATURES RANGED FROM THE LOW TO
MID 30S IN THE FAR EASTERN FA TO THE SINGLE DIGITS IN THE FAR NW
FA.
THROUGH TONIGHT...THE CLIPPER SYSTEM WILL CONTINUE TO MOVE EAST.
THE STRONG NW WINDS CARRYING QUITE THE ARCTIC BLAST WILL CONTINUE
TO INCREASE LATE THIS AFTERNOON...PERHAPS PEAK EARLY THIS
EVENING...THEN GRADUALLY RELAX THROUGH THE REST OF THE NIGHT. THE
EXCEPTION COULD BE ALONG THE IMMEDIATE NORTH SHORE WHERE
WINDS...ESPECIALLY GUSTS...WILL LIKELY STRENGTHEN INTO THIS
EVENING AND PEAK AROUND MIDNIGHT. THIS IS BASED ON THE LATEST RUNS
OF THE HRRR AND LOCAL WRF MODELS. THOSE MODELS SUGGEST WIND GUSTS
UP TO 50 KT. NOT SURE IF THE GUSTS WILL BE THAT STRONG...BUT
DECIDED TO ISSUE A WIND ADVISORY FOR THE NORTH SHORE THROUGH 09Z
TONIGHT FOR GUSTS UP TO 50 MPH. THE CURRENT WIND ADVISORY FROM
SOUTHERN CASS COUNTY TO BURNETT COUNTY STILL LOOKS GOOD THROUGH
03Z. WIND CHILL VALUES WILL PLUMMET TONIGHT WITH THE FALLING
TEMPERATURES...AND THE CURRENT WIND CHILL ADVISORY FOR TONIGHT AND
INTO TOMORROW MORNING DOES NOT NEED ANY CHANGES. LAKE EFFECT SNOW
SHOWERS WILL INCREASE ACROSS THE SOUTH SHORE TONIGHT...ESPECIALLY
THE GOGEBIC RANGE IN IRON COUNTY...AS THE STRONG COLD NW WINDS
DEVELOP OVER WESTERN LAKE SUPERIOR. WILL NOT BE MAKING CHANGES TO
THE CURRENT LAKE EFFECT SNOW ADVISORY FOR IRON COUNTY AS PARTS OF
THE COUNTY COULD GET SEVERAL INCHES OF SNOW THROUGH SUNDAY
MORNING.
SUNDAY AND SUNDAY NIGHT...IT WILL BE A PARTICULARLY COLD DAY
ACROSS THE NORTHLAND WITH MUCH OF REGION NOT EVEN REACHING ZERO
DEGREES. LAKE EFFECT SNOW SHOWERS WILL LIKELY CONTINUE FOR THE
SOUTH SHORE. ANOTHER WIND CHILL ADVISORY OR WARNING WILL LIKELY BE
NEEDED. SOME PARTS OF FAR NORTHERN MINNESOTA COULD HAVE WIND CHILL
VALUES APPROACHING 50 DEGREES BELOW ZERO.
LONG TERM.../MONDAY - FRIDAY NIGHT/
MODELS SHOWING GOOD AGREEMENT THAT THE CORE OF COLDEST H85-H50 AIR
PUSHES INTO THE NORTHERN AREAS EARLY MONDAY MORNING...SWINGING
THROUGH THE NORTHLAND THROUGH 00Z TUESDAY. AT THIS TIME WIND CHILL
VALUES IN THE NEIGHBORHOOD OF NEGATIVE 30 TO 50 ARE EXPECTED EARLY
MONDAY MORNING WITH VERY LITTLE IMPROVEMENT THROUGH THE DAY. THE
LATEST ECM/GFS SUGGEST THAT THE WRN LAKE SUPERIOR REGION REMAINS ON
THE BACK EDGE OF THE ARCTIC AIR MASS THROUGH MUCH OF THE WEEK WITH A
PERSIST ANT NORTHWEST FLOW. HAVE KEPT POPS ACROSS THE SOUTH SHORE
ZONES FOR AN ONGOING PERIOD OF LAKE EFFECT SNOW AS WELL.
AVIATION.../18Z TAF ISSUANCE/
MVFR CIGS WITH -SN AND BLSN WILL PREVAIL THROUGH 00Z..THEN
GRADUALLY IMPROVING TO VFR GENERALLY AFTER 06Z. NORTHWEST WINDS
WILL INCREASE THROUGH THE AFTERNOON WITH GUSTS OF 30 TO 35 KTS
COMMON ACROSS THE FORECAST ARES THROUGH THE 20Z TO 06Z PERIOD.
HIGHER GUSTS AROUND 40 KT WILL BE POSSIBLE AT THE KBRD AND KDLH
TERMINALS AROUND 00Z...WITH THE STRONGEST GUSTS OF 45-50 KT
EXPECTED ALONG THE NORTH SHORE OF LAKE SUPERIOR AFTER 03Z.
&&
.POINT TEMPS/POPS...
DLH -10 0 -21 -9 / 10 10 10 10
INL -20 -5 -30 -12 / 10 10 10 10
BRD -12 1 -22 -10 / 10 10 10 0
HYR -9 3 -18 -7 / 20 10 10 10
ASX -3 6 -13 -4 / 60 30 50 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL NOON CST SUNDAY FOR MNZ010>012-018>021-
025-026-033>038.
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR MNZ020-021.
WI...WIND CHILL ADVISORY UNTIL NOON CST SUNDAY FOR WIZ001>004-006>009.
LAKE EFFECT SNOW ADVISORY UNTIL NOON CST SUNDAY FOR WIZ004.
LS...NONE.
&&
$$
AVIATION...GSF
AREA FORECAST DISCUSSION...UPDATED
NWS HASTINGS NE
957 PM CST MON JAN 21 2013
.UPDATE...THE RUC CONTINUES TO GENERATE LIGHT SNOW ACROSS OUR
NORTHEAST ZONES THIS EVENING...WHICH THUS FAR HAS FAILED TO
MATERIALIZE. THE NAM PUTS THE BEST CHANCE OF LIGHT SNOW JUST TO
THE NORTHEAST OF OUR CWA AFTER MIDNIGHT. OVERALL CONFIDENCE IN
SEEING LIGHT SNOWFALL ACCUMULATIONS ACROSS OUR NORTHEAST ZONES HAS
DECREASED AND THEREFORE HAVE TRENDED SLIGHTLY LOWER WITH POPS.
&&
.PREV DISCUSSION... /ISSUED 549 PM CST MON JAN 21 2013/
AVIATION...00Z KGRI TAF. CLOUDS WILL LIKELY STICK AROUND
THROUGHOUT THE TAF VALID PERIOD WITH CEILINGS VARYING FROM MVFR
TO LOW END VFR AS A JET STREAK RESULTS IN ENOUGH LIFT TO PERHAPS
SQUEEZE OUT A FEW SNOW FLURRIES OVERNIGHT. THE WIND WILL BE LIGHT
AND GENERALLY OUT OF THE EAST THIS EVENING...BUT WILL BECOME MORE
SOUTHEAST DURING THE DAY TOMORROW.
PREV DISCUSSION... /ISSUED 245 PM CST MON JAN 21 2013/
SHORT TERM...TONIGHT AND TUESDAY. FOCUS IS ON LIGHT SNOW POTENTIAL
FOR TONIGHT. THE PATTERN ALOFT PLACED AN UPPER RIDGE AXIS ALONG THE
WEST COAST STATES...NORTHWEST FLOW ACROSS THE INTERIOR CONUS WITH
AN UPPER LOW ORIENTED FM ONTARIO SOUTH THRU THE OHIO VALLEY. AN
ARCTIC AIRMASS HAD SETTLED ACROSS THE DAKOTAS THRU THE EASTERN
PORTIONS OF THE CENTRAL PLAINS STATES...AND AT THE SURFACE...A 1032MB
SURFACE HIGH WAS ORIENTED ALONG THE MISSOURI RIVER.
BANDS OF SNOW DEVELOPED THIS MORNING ACROSS OUR NORTHERN/EASTERN
ZONES AS A 150KT JET STREAK NOSED SOUTH ALONG THE MISSOURI
RIVER...DRIVING SHEARED ENERGY SOUTH ACROSS THE PLAINS. THE SNOW
DEVELOPED IN AN AREA OF MID LEVEL FRONTOGENESIS AND THE AREA OF LIFT
WAS ALSO DEPICTED WELL ON THE 290K ISENTROPIC SURFACE. HAD A REPORT
OF SOME AREAS PICKING UP SNOW OF A HALF INCH TO THREE QUARTERS OF AN
INCH IN THE HEAVIER BANDS...AND VSBYS DROPPED BELOW TWO MILES AT
TIMES.
MODELS ARE PRETTY CONSISTENT INDICATING THAT THIS INITIAL ROUND OF
SNOW WILL CONTINUE TO WIND DOWN THIS AFTERNOON IN DECREASING
LIFT/DYNAMICS...WITH ANOTHER ROUND OF SNOW SETTING UP THIS
EVENING/TONIGHT. LIFT INCREASES AGAIN TONIGHT WITH A 130KT JET
STREAK NOSING SOUTH THRU EASTERN NEBRASKA...AGAIN NEAR THE MISSOURI
RIVER. THIS AGAIN DRIVES SHEARED ENERGY SOUTH AND ISENTROPIC LIFT
INCREASES THIS EVENING WITH BETTER LIFT HEADING INTO TONIGHT. SNOW
IS EXPECTED TO REDEVELOP ACROSS OUR NORTHERN ZONES INITIALLY AND
SPREAD SOUTH AND AFFECT OUR EAST/NORTHEAST ZONES OVERNIGHT...OR
GENERALLY PRETTY MUCH ACROSS THE SAME AREAS WHICH SAW SNOWFALL
TODAY. SNOWFALL ACCUMULATIONS ARE EXPECTED TO REMAIN RATHER
LIGHT...GENERALLY A DUSTING TO UP TO ONE INCH. THE LIGHT SNOWFALL
POTENTIAL IS BEST SUPPORTED BY SREF...12Z SPC WRF AND RUC/RAP.
DECIDED TO HANDLE THIS EVENT WITH HIGH POPS AND LOW SNOWFALL
ACCUMULATIONS. SET UP LOOKS GOOD FOR SNOW BUT AMOUNTS SHOULD NOT
BE HIGH.
CURRENT FORECAST HAS FOG POTENTIAL TONIGHT...AND LEFT THIS IN AS
DEVELOPMENT STILL LOOKS POSSIBLE ALONG OUR SOUTHERN/WESTERN ZONES IN
LIGHT EASTERLY RETURN FLOW FM SFC HIGH TO THE EAST AND THESE
LOCATIONS WILL ALSO BE ON THE EDGE/PERIPHERY OF THE STRATUS. HRRR
VSBY PROGS ACTUALLY INDICATE POTENTIAL FOR DENSE FOG ACROSS PORTIONS
OF WESTERN NEB/KS WITH OUR WESTERN ZONES ON THE EDGE OF THIS.
DEFINITELY SOMETHING TO KEEP AN EYE ON TONIGHT.
SOME FLURRIES MAY LINGER FOR A FEW HOURS TUESDAY MORNING IN OUR
NORTHEAST...WITH POTENTIAL FOR FOG REMAINING IN THE MORNING IN OUR
SOUTH/WEST. THE SURFACE RIDGE AXIS CONTINUES TO GRADUALLY SHIFT EAST
AND HEIGHTS BEGIN TO RISE ACROSS THE PLAINS. LOW CLOUDS BEGIN TO
ERODE FM WEST/EAST BUT STILL NOT LOOKING FOR A WHOLE LOT OF
IMPROVEMENT IN TEMPS TOMORROW AFTN IN OUR EAST...ALTHOUGH SOME LOW
20S ARE POSSIBLE. TO THE WEST...IN INCREASING INSOLATION AND
PROXIMITY TO WARMER AIR...READINGS NEAR 40F ARE POSSIBLE.
LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN LIES WITH
TEMPERATURES.
NORTHWESTERLY FLOW IN THE UPPER LEVELS IS EXPECTED TO BE IN PLACE AT
THE START OF THE LONG TERM PERIOD...WITH BROAD TROUGHING IN PLACE
OVER THE MIDWEST/EAST COAST AND A RIDGE AXIS EXTENDING THROUGH THE
ROCKIES AND INTO CANADA. THE SURFACE PATTERN STARTS OUT WITH LIGHT
GENERALLY SOUTHERLY WINDS ACROSS THE CWA...AS HIGH PRESSURE
ENCOMPASSES MUCH OF THE CONUS EAST OF THE MO RIVER...AND A TROUGH OF
LOW PRESSURE REMAINS OVER THE HIGH PLAINS.
THE FORECAST THROUGH WEDNESDAY NIGHT REMAINS DRY WITH NO NOTABLE
SYSTEMS TAKING AIM ON THE REGION...THOUGH AN UPPER LEVEL DISTURBANCE
SWINGING OUT OF CANADA AND INTO THE GREAT LAKES REGION DURING THE
DAYTIME HOURS ON WEDNESDAY WILL HAVE SOME IMPACT ON OUR CWA. A
BACKDOOR FRONT WILL WORK ITS WAY INTO THE AREA FROM THE
N/NE...BRINGING NE/E WINDS AND IS EXPECTED TO KEEP ROUGHLY THE
NORTHEASTERN HALF OF THE CWA IN THE MID/UPPER 30S FOR HIGHS...WITH
THE SOUTH AND WEST IN THE 40S.
A LITTLE MORE UNCERTAINTY IN THE FORECAST ARISES AS WE GET INTO
THURSDAY...MAINLY WITH THE TIMING OF ANOTHER COLD FRONT EXPECTED TO
PUSH THROUGH THE NRN/CENTRAL PLAINS. ANOTHER...STRONGER UPPER LEVEL
DISTURBANCE WILL AGAIN PUSH OUT OF CENTRAL CANADA AND MOVE SOUTHEAST
THROUGH THE NORTHERN PLAINS AND EVENTUALLY INTO THE MIDWEST. THE
12Z NAM WAS AN OUTLIER COMPARED TO OTHER MODELS WITH THE TIMING OF
THE FRONT...ALREADY MAKING A GOOD PUSH THROUGH THE CWA BY MIDDAY
THURSDAY...WITH THE EC/GFS/SREF ALL SLOWER AND BRINGING THE FRONT
TROUGH MORE DURING THE THURS EVENING/OVERNIGHT HOURS. KEPT THE
FORECAST CLOSER TO THOSE SLOWER SOLUTIONS. AS HAS BEEN THE CASE THE
PAST FEW DAYS...MODELS CONTINUING TO SHOW BETTER PRECIPITATION
CHANCES REMAINING WELL TO THE SOUTH OF THE CWA CLOSER TO THE MAIN
SFC WARM FRONT...AND TO THE NORTH WITH THE BETTER UPPER LEVEL
FORCING. THIS FRONT WILL USHER IS COLDER AIR AND LOWER TEMPERATURES
FOR FRIDAY...AND FORECAST HIGHS RANGE FROM THE LOWER 20S IN THE
NORTHEAST TO THE UPPER 30S IN THE SOUTHWEST.
ALREADY FRIDAY NIGHT...MODELS IN GOOD AGREEMENT SHOWING THIS LATEST
BATCH OF COLDER STARTING TO SHIFT OFF TO THE EAST OF THE CWA...AS
RIDGING STARTS TO REAMPLIFY OVER THE ROCKIES WITH ANOTHER UPPER
LEVEL TROUGH OF THE WEST COAST. THIS RIDGE LOOKS TO REMAIN THE MAIN
PLAYER IN THE UPPER LEVELS THROUGH AT LEAST THE UPCOMING
WEEKEND...WITH A LITTLE MORE UNCERTAINTY WHETHER IT CONTINUES INTO
MONDAY LIKE THE 12Z EC IS SHOWING /THE GFS SHOWS ANOTHER FRONT
MOVING THROUGH/. FORECAST CURRENTLY CALLING FOR MID 30S/MID 40S FOR
HIGHS ON SAT...WITH MID 40S/LOWER 50S FOR SUN/MON. IF THE ECMWF
SOLUTION IS THE ONE OTHER MODELS TREND TOO...MAY NEED UPWARD TWEAKS
FOR SUN/MON TEMPS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1243 PM CST SUN JAN 20 2013
.UPDATE...JUST SHIPPED ANOTHER UPDATE ADDRESSING ONLY THIS
AFTERNOON...AS LATEST OBSERVATIONS AND SHORT TERM MODELS/GUIDANCE SUCH
AS HRRR AND GFS LAMP UNFORTUNATELY CONFIRM THAT MORE CUTS IN HIGH
TEMPERATURES WERE NEEDED ACROSS THE CWA. IN GENERAL...TOOK ANOTHER
2-5 DEGREES OFF NEARLY ALL AREAS...MEANING THAT HIGHS ARE NOW
FORECAST TO END UP GENERALLY 5-10 DEGREES COOLER THAN ORIGINAL
EARLY MORNING FORECAST. THIS NOW MEANS THAT ROUGHLY THE NORTHEAST 1/2
OF THE CWA IS UNLIKELY TO REACH 30...WITH FAR NORTH/NORTHEAST
COUNTIES UNLIKELY TO REACH 25. ACROSS SOUTHWESTERN-MOST NEB ZONES
AND NORTH CENTRAL KS...MOST AREAS ARE NOW EXPECTED TO TOP OUT
SOMEWHERE IN THE 30S...WITH ANY LOW 40S MOST FAVORED IN SOUTHERN
PARTS OF ROOKS/OSBORNE COUNTIES. OTHERWISE...OTHER ELEMENTS OF
AFTERNOON FORECAST REMAIN LARGELY ON TRACK...WITH NORTH WINDS
EVENTUALLY PICKING UP TOWARD 10-20 MPH ESPECIALLY NEAR/AFTER 3 PM
AND SKIES CONTINUING TO AVERAGE MOSTLY CLOUDY DUE TO A COMBINATION
OF PASSING MID-HIGH CLOUDS AND GRADUALLY INCREASING PATCHES OF
LOWER CLOUDS.
&&
.PREV DISCUSSION... /ISSUED 1130 AM CST SUN JAN 20 2013/
AVIATION...18Z KGRI TAF. CONFIDENCE IN CEILING TRENDS IS NOT ALL
THAT HIGH THROUGH THE NEXT 24 HOURS...BUT ITS LOOKING INCREASINGLY
LIKELY THAT A GOOD CHUNK OF THIS TIME FRAME COULD BE DOMINATED BY
AN MVFR CEILING. LATEST VISIBLE SATELLITE AND SHORT TERM MODEL
TRENDS INDICATE THAT MVFR CLOUDS SOMEWHERE BETWEEN 1500 AND 3000
FT AGL SHOULD DEVELOP INTO THE TERMINAL AREA EARLY THIS
AFTERNOON...AND COULD VERY WELL STICK AROUND ON AT LEAST AN OFF/ON
BASIS THROUGH THE REST OF THE PERIOD. INSTEAD OF TRYING TO PIN
DOWN ANY POSSIBLE TIME FRAMES WHERE CEILING MIGHT LIFT OR SCATTER
INTO VFR...WILL SIMPLY KEEP A PREVAILING MVFR TREND GOING FOR
NOW...KNOWING THAT FUTURE UPDATES/DISCUSSIONS WILL ADDRESS THE
LATEST SHORT TERM TRENDS. THERE IS EVEN SOME INDICATION THAT THE
LATTER HALF OF THE PERIOD COULD SEE CEILINGS DROP TOWARD IFR
LEVELS...BUT CONFIDENCE IS NOT HIGH ENOUGH TO GO THIS LOW YET. AS
FOR VISIBILITIES...CONFIDENCE REMAINS RATHER HIGH IN CONTINUED
VFR. SURFACE BREEZES WILL START OUT LIGHT/VARIABLE BEFORE AT LEAST
A BRIEF PERIOD OF STRONGER NORTH WINDS MOVE IN THIS AFTERNOON WITH
GUST POTENTIAL 15-20KT. A GENERALLY NORTH BREEZE NEAR/LESS THAN
10KT SHOULD THEN PREVAIL THIS EVENING THROUGH MONDAY MORNING.
FINALLY...WILL LEAVE OUT ANY MENTION OF SNOW...ALTHOUGH A FEW
FLURRIES CANNOT BE RULED OUT LATE TONIGHT INTO MONDAY MORNING.
PREV DISCUSSION... /ISSUED 1046 AM CST SUN JAN 20 2013/
UPDATE...FOR NOT HAVING HIGH IMPACT WEATHER...TODAY/S FORECAST
REMAINS CHALLENGING ESPECIALLY REGARDING TEMPERATURE TRENDS.
ALTHOUGH CONFIDENCE IN THE HOURLY DETAILS REMAINS SOMEWHAT BELOW
AVERAGE...THE OVERALL MESSAGE FROM VARIOUS MODEL/GUIDANCE SOURCES
SUCH AS HRRR...RAP AND GFS LAMP STRONGLY SUGGESTED THAT PREVIOUS
HIGHS WERE AT LEAST A BIT TOO WARM. AS A RESULT...TRIMMED AT LEAST
1-2 DEGREES OFF HIGHS FOR GENERALLY THE SOUTHWESTERN 2/3 OF THE
CWA...BUT MADE MORE SIGNIFICANT 5-7 DEGREE CUTS TO ESPECIALLY THE
NORTHEAST 1/4 OF OUR AREA...OR ESPECIALLY NORTHEAST OF AN ORD-YORK
LINE. IN THESE NORTHEAST AREAS...TEMPS WILL BE LUCKY TO REACH THE
MID-UPPER 20S...WHILE AT LEAST LOW-MID 30S STILL LOOK POSSIBLE
ACROSS MOST OF THE REMAINDER OF OUR NEB ZONES. KS ZONES COULD
STILL MAKE A RUN AT THE LOW 40S...ALTHOUGH EVEN HERE MAY CONSIDER
LOWERING A BIT IN A FUTURE UPDATE. OTHERWISE...A GENERALLY LIGHT
AND VARIABLE WIND REGIME WILL REMAIN IN PLACE ALL AREAS UNTIL AT
LEAST EARLY AFTERNOON...BUT THEREAFTER A GRADUAL INCREASE IN
NORTHERLY SPEEDS WILL START OVERTAKING THE CWA FROM WEST TO
EAST...WITH AT LEAST A SHORT PERIOD OF 20+ MPH GUSTS EXPECTED TO
AFFECT MOST ALL AREAS BY MID-LATE AFTERNOON. PRECIP-WISE...WILL
CONTINUE TO LEAVE FLURRIES OUT OF THIS AFTERNOON/S FORECAST FOR
OUR FAR NORTHEAST COUNTIES...AS RADAR TRENDS AND SHORT TERM MODELS
CONTINUE TO SUGGEST THAT ANY SUCH ACTIVITY SHOULD LARGELY SLIDE BY
JUST TO OUR NORTHEAST.
PREV DISCUSSION... /ISSUED 414 AM CST SUN JAN 20 2013/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. PRIMARY FORECAST
CONCERN LIES WITH TEMPERATURES.
QUIET CONDITIONS REMAIN IN PLACE ACROSS THE REGION EARLY THIS
MORNING...WITH SATELLITE AND UPPER AIR PROFILER DATA SHOWING
NORTHWESTERLY FLOW IN PLACE. RIDGING CONTINUES ALONG THE WEST
COAST...WHILE A COUPLE OF DISTURBANCES WORK THEIR WAY THROUGH THE
NWRLY FLOW...ONE OVER THE GREAT LAKES REGION AND THE OTHER OVER SC
CANADA. AT THE SURFACE...HIGH PRESSURE CONTINUES TO SLIDE SOUTH
OUT OF THE DAKOTAS INTO THE AREA...BEHIND A COLD FRONT WHICH
PASSED THROUGH THE REGION LATE SAT AFTN/EVENING. WITH TIME...WINDS
HAVE GRADUALLY BECOME MORE EASTERLY ACROSS THE CWA...AND HAVE
DIMINISHED IN SPEED.
LOOKING AT THE REST OF TODAY AND INTO MONDAY...THE MAIN STORY LIES
WITH THE PASSAGE OF YET ANOTHER COLD FRONT...AND ITS AFFECT ON
TEMPERATURES. MODELS REMAIN IN GOOD AGREEMENT SHOWING THE ABOVE
MENTIONED UPPER LEVEL DISTURBANCE OVER SC CANADA CONTINUING TO
SLIDE SOUTHEAST THROUGH THE DAY TODAY...WITH THE TIMING OF THE
ACCOMPANYING SFC COLD FRONT/NORTHWESTERLY WINDS STILL EXPECTED TO
PASS THROUGH THE CWA DURING THE AFTERNOON HOURS. THE TIMING MAKES
TEMPERATURES TODAY PRETTY DIFFICULT...ESP WITH MODELS/GUIDANCE NOT
IN VERY GOOD AGREEMENT...MAINLY FOR THOSE NORTHWESTERN PORTIONS OF
THE CWA...WHICH WILL PROB SEE THEIR HIGHS CLOSER TO MIDDAY/EARLY
AFTN VS MID AFTN FURTHER SOUTH. OVERALL DIDNT MAKE MANY CHANGES TO
THE INHERITED FORECAST...WHICH CONTINUES TO CALL FOR GENERALLY MID
30S ACROSS SC NEB...WITH LOWER 40S IN NC KS. CERTAINLY SOMETHING
FOR THE DAYSHIFT TO KEEP AN EYE ON.
AS FAR AS THE POSSIBILITY OF FLURRIES GOES...DECIDED TO KEEP THE
MENTION OUT OF THE FORECAST. AS THAT DISTURBANCE SWINGS SOUTH...IT
WILL BRING ALONG MORE CLOUD COVER AND COLDER TEMPERATURES...AND
WHILE MODELS DO SHOW SOME BATCHES OF INCREASED LOWER LEVEL /BELOW
700MB/ MOISTURE MOVING INTO THE REGION...MAINLY THIS
AFTERNOON...THERE IS ALSO PRETTY GOOD AGREEMENT WITH KEEPING THE
BETTER RH AND COLDER TEMPS MORE FAVORABLE FOR FLURRIES
NORTH/NORTHEAST OF THE CWA...BARELY. THE OPER NAM/GFS/EC CONTINUE
TO SHOW THE CWA DRY...AS DOES THE HRRR. THE RAP AND ONE RUN OF THE
4 KM SHOW PERHAPS THE FAR N/NE EDGE OF THE CWA MAYBE SEEING A
FEW...BUT AM GOING TO CONTINUE TO EXCLUDE THE MENTION.
REALLY THE BRUNT OF THE COLDER AIR HOLDS OFF FROM MOVING INTO THE
CWA UNTIL LATER TODAY AND MAINLY THIS EVENING/TONIGHT. AS HAS BEEN
THE CASE OVER THE PAST FEW DAYS...MODELS CONTINUE TO SHOW THE
MAIN AXIS OF THE TROUGH...AND THUS THE COLDEST AIR...SETTING UP
JUST EAST OF THE CWA TONIGHT/THROUGH MONDAY. WHILE THE CWA MAY
CATCH A BRIEF BREAK FROM CLOUD COVER TONIGHT...EXPECTING TO SEE
ADDITIONAL CLOUD COVER /MAINLY UPPER LEVEL/ STREAMING IN FROM THE
NORTHWEST...KEEPING MAINLY THE NORTHEASTERN HALF OF THE CWA UNDER
PARTLY/MOSTLY CLOUDY SKIES ON MONDAY. DIDNT MAKE ANY NOTABLE
CHANGES TO MONDAYS HIGHS...WHICH RANGE FROM THE LOWER 20S IN THE
NORTHEAST TO LOWER 30S IN THE SOUTHWEST. SURFACE HIGH PRESSURE
SLIDING IN FROM THE NORTHWEST WILL BRING FAIRLY LIGHT WINDS FOR
MOST LOCATIONS.
MONDAY NIGHT THROUGH TUESDAY...THE MAIN UPPER LEVEL TROUGH/COLDEST
AIR ALREADY STARTS ITS EASTWARD SHIFT MONDAY NIGHT...WHICH WILL
BRING A REBOUND IN TEMPS FOR TUESDAY. THE POSSIBILITY OF GETTING
CLIPPED IN THE NORTH BY MORE FLURRIES OR LIGHT SNOW WILL BE
SOMETHING TO CONSIDER WITH UPCOMING MODEL RUNS. CURRENTLY AM
KEEPING THE MENTION OUT OF THE FORECAST...WITH MODELS SHOWING THE
COLDER TEMPS AND BETTER POTENTIAL /MAINLY MONDAY NIGHT INTO THE
FIRST HALF OF TUESDAY/...DRIVEN BY A STRONG UPPER LEVEL JET
STREAK NOSING IN FROM THE N/NW...REMAINING ONCE AGAIN JUST OUTSIDE
THE N/NE EDGE OF THE CWA. WITH THE WARMER AIR STARTING TO BUILD
BACK IN FROM THE WEST...HIGHS CURRENTLY RANGE FROM THE UPPER 20S
IN THE NORTHEAST TO LOWER 40S IN THE WEST...AND SOME MODELS
SUGGEST THE WEST SHOULD BE WARMER. OVERNIGHT LOWS EXPECTED TO
REBOUND FROM THE SINGLE DIGITS/TEENS MONDAY NIGHT TO THE
TEENS/NEAR 20 TUESDAY NIGHT.
LONG TERM...(WEDNESDAY THRU SATURDAY)
THE MAIN STORY: BONE DRY PATTERN CONTINUES WITH RE-AMPLIFYING NW
FLOW STUNTING TEMP RECOVERY...BUT SIGNALS CONTINUE FOR SOME PRECIP
POTENTIAL VERY LATE THIS MONTH.
PATTERN: THE HIGHLY AMPLIFIED WRN N AMERICA RIDGE/ERN TROF WILL
MEET ITS DEMISE NEXT WEEK AS A PACIFIC SHRTWV TROF MOVES ONSHORE
IN THE PAC NW WED AND MOVES THRU THE RIDGE. AS THIS TROF MOVES
INTO THE LGWV TROF THU-FRI...THE PATTERN WILL RE-AMPLIFY
SOMEWHAT...CURBING OUR WARM-UP FRI-SAT. RIDGING THEN ADVANCES OVER
THE PLAINS NEXT WEEKEND...FOLLOWED BY LOWERING HGTS OVER WRN N
AMERICA THE LAST WEEK OF JAN...SUGGESTING A PERIOD OF STORMINESS
AND PCPN POTENTIAL.
MODELS: THERE IS GOOD AGREEMENT AMONGST THE 00Z EC/GFS/GEM ON THIS
SCENARIO THRU 00Z/SAT. THE ONE CAVEAT...THE OPERATIONAL 18Z/00Z GFS
ARE NOT AS AMPLIFIED WITH THE TEMPORARILY REINVIGORATED RIDING OVER
WRN N AMERICA. IN FACT...THE GFS ENSEMBLE MEAN IS CLOSER TO THE
MORE AMPLIFIED 12Z/00Z EC CYCLES. THIS FCST INCORPORATES
EC/GFS/GEM/HPC GUIDANCE THRU 00Z/SAT. BEYOND THAT ITS HPC/EC AND
EC/GFS ENSEMBLE MEANS.
TEMPS: ESSENTIALLY NEAR NORMAL THRU SAT WITH ONE DAY OF BELOW
NORMAL FRI.
HAZARDS: NONE ENVISIONED ATTM.
UPCOMING PCPN OPPORTUNITIES: NOTHING NOTABLE THRU AT LEAST SAT AND
PROBABLY TO MON 1/28. HOWEVER...ODDS ARE INCREASING FOR A MDT
PCPN EVENT AS WE CLOSE THE BOOKS ON JAN.
THE DAILY DETAILS...
WED: M/SUNNY. PROBABLY NEAR NORMAL TEMPS. LEE TROF INTENSIFIES
WITH TROF MOVING INTO PAC NW...AIDING IN MODEST TEMP RECOVERY.
TEMP CONFIDENCE GRAPHICS SHOW ABOVE NORMAL SPREAD IN TEMPS.
THU: P/CLOUDY. A DRY COLD FRONTAL PASSAGE IN THE PRE-DAWN HRS. LOW
PRES EJECTS OUT OF CO ACROSS KS/OK. SOME DIFF/S IN TIMING REMAIN
WITH THE EC/GEM FASTER AND MORE POTENT THAN THE GFS. THE 00Z EC
ENSEMBLES HAVE COME INTO MUCH BETTER AGREEMENT ON SLP SINCE ITS
12Z RUN. HPC IS IN AGREEMENT SO WE/LL ROLL WITH THIS SCENARIO.
ABOVE NORMAL UNCERTAINTY IN TEMPS.
THU HAS POTENTIAL TO BE A BREEZY DAY. HOWEVER...SOME BAGGINESS IN
THE PRES TROF OF A REINFORCING SHOT OF COLD AIR COULD MITIGATE.
THU NGT: ANOTHER PUSH OF COLDER AIR MOVES THRU AS THE SHRTWV TROF
PASSES...BUT THE WORST OF IT REMAINS OFF TO THE N AND E.
FRI: P/CLOUDY. ARCTIC HIGH PRES EXPANDS OVER THE MS VALLEY. IF THE
EC IS RIGHT ANOTHER WEAK LOW MOVES THRU DELIVERING ANOTHER PUSH OF
MARGINALLY COLD AIR. CONFIDENCE IS ABOVE NORMAL ON A COOL DOWN.
TEMPS PROBABLY CLOSE TO 10F BELOW NORMAL.
SAT: SUNNY AS YET ANOTHER ARCTIC HIGH EXPANDS OVER THE MS VALLEY.
HGTS BEGIN RISING AS BROAD RIDGING ADVANCES TOWARD THE PLAINS. WAA
BEGINS WITH A NEW LEE TROF DEVELOPING.
BEYOND SAT...
A VERY NICE WARM-UP COMMENCES SUN THAT COULD LINGER INTO EARLY THE
FOLLOWING WEEK 1/28-29 DEPENDENT ON HOW THE PATTERN SHAPES UP.
WE COULD SEE 1 OR 2 DAYS OF MUCH ABOVE NORMAL TEMPS (+10F OR
MORE). IF WE ROLL WITH THE OPERATIONAL EC AND THE EC/GFS ENSEMBLES
LATE THIS WEEK...THEN WE MUST GO SLOWER THAN THE OPERATIONAL GFS
FOR EARLY THE FOLLOWING WEEK. THE GREATER AMPLIFIED SCENARIO WILL
SLOW THINGS DOWN UPSTREAM. EITHER WAY...THE NEXT PAC TROF WILL DIG
INTO THE DESERT SW THE LAST WEEK OF JAN. THIS IS A FAVORABLE SETUP
FOR A DECENT PCPN EVENT HERE AND WITH THE LOW TRACKING S OF THE
FCST AREA...THIS COULD END UP BEING THE WINTRY VARIETY. HOPEFULLY
WE/LL HAVE TIME TO ENTRAIN GOOD MSTR AFTER MULTIPLE EPISODES OF
CONTINENTAL POLAR AIR HAVE PLUNGED INTO THE GULF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATES/AVIATION...PFANNKUCH
SHORT TERM...ADO
LONG TERM...HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1130 AM CST SUN JAN 20 2013
.AVIATION...18Z KGRI TAF. CONFIDENCE IN CEILING TRENDS IS NOT ALL
THAT HIGH THROUGH THE NEXT 24 HOURS...BUT ITS LOOKING INCREASINGLY
LIKELY THAT A GOOD CHUNK OF THIS TIME FRAME COULD BE DOMINATED BY
AN MVFR CEILING. LATEST VISIBLE SATELLITE AND SHORT TERM MODEL
TRENDS INDICATE THAT MVFR CLOUDS SOMEWHERE BETWEEN 1500 AND 3000
FT AGL SHOULD DEVELOP INTO THE TERMINAL AREA EARLY THIS
AFTERNOON...AND COULD VERY WELL STICK AROUND ON AT LEAST AN OFF/ON
BASIS THROUGH THE REST OF THE PERIOD. INSTEAD OF TRYING TO PIN
DOWN ANY POSSIBLE TIME FRAMES WHERE CEILING MIGHT LIFT OR SCATTER
INTO VFR...WILL SIMPLY KEEP A PREVAILING MVFR TREND GOING FOR
NOW...KNOWING THAT FUTURE UPDATES/DISCUSSIONS WILL ADDRESS THE
LATEST SHORT TERM TRENDS. THERE IS EVEN SOME INDICATION THAT THE
LATTER HALF OF THE PERIOD COULD SEE CEILINGS DROP TOWARD IFR
LEVELS...BUT CONFIDENCE IS NOT HIGH ENOUGH TO GO THIS LOW YET. AS
FOR VISIBILITIES...CONFIDENCE REMAINS RATHER HIGH IN CONTINUED
VFR. SURFACE BREEZES WILL START OUT LIGHT/VARIABLE BEFORE AT LEAST
A BRIEF PERIOD OF STRONGER NORTH WINDS MOVE IN THIS AFTERNOON WITH
GUST POTENTIAL 15-20KT. A GENERALLY NORTH BREEZE NEAR/LESS THAN
10KT SHOULD THEN PREVAIL THIS EVENING THROUGH MONDAY MORNING.
FINALLY...WILL LEAVE OUT ANY MENTION OF SNOW...ALTHOUGH A FEW
FLURRIES CANNOT BE RULED OUT LATE TONIGHT INTO MONDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 1046 AM CST SUN JAN 20 2013/
UPDATE...FOR NOT HAVING HIGH IMPACT WEATHER...TODAY/S FORECAST
REMAINS CHALLENGING ESPECIALLY REGARDING TEMPERATURE TRENDS.
ALTHOUGH CONFIDENCE IN THE HOURLY DETAILS REMAINS SOMEWHAT BELOW
AVERAGE...THE OVERALL MESSAGE FROM VARIOUS MODEL/GUIDANCE SOURCES
SUCH AS HRRR...RAP AND GFS LAMP STRONGLY SUGGESTED THAT PREVIOUS
HIGHS WERE AT LEAST A BIT TOO WARM. AS A RESULT...TRIMMED AT LEAST
1-2 DEGREES OFF HIGHS FOR GENERALLY THE SOUTHWESTERN 2/3 OF THE
CWA...BUT MADE MORE SIGNIFICANT 5-7 DEGREE CUTS TO ESPECIALLY THE
NORTHEAST 1/4 OF OUR AREA...OR ESPECIALLY NORTHEAST OF AN ORD-YORK
LINE. IN THESE NORTHEAST AREAS...TEMPS WILL BE LUCKY TO REACH THE
MID-UPPER 20S...WHILE AT LEAST LOW-MID 30S STILL LOOK POSSIBLE
ACROSS MOST OF THE REMAINDER OF OUR NEB ZONES. KS ZONES COULD
STILL MAKE A RUN AT THE LOW 40S...ALTHOUGH EVEN HERE MAY CONSIDER
LOWERING A BIT IN A FUTURE UPDATE. OTHERWISE...A GENERALLY LIGHT
AND VARIABLE WIND REGIME WILL REMAIN IN PLACE ALL AREAS UNTIL AT
LEAST EARLY AFTERNOON...BUT THEREAFTER A GRADUAL INCREASE IN
NORTHERLY SPEEDS WILL START OVERTAKING THE CWA FROM WEST TO
EAST...WITH AT LEAST A SHORT PERIOD OF 20+ MPH GUSTS EXPECTED TO
AFFECT MOST ALL AREAS BY MID-LATE AFTERNOON. PRECIP-WISE...WILL
CONTINUE TO LEAVE FLURRIES OUT OF THIS AFTERNOON/S FORECAST FOR
OUR FAR NORTHEAST COUNTIES...AS RADAR TRENDS AND SHORT TERM MODELS
CONTINUE TO SUGGEST THAT ANY SUCH ACTIVITY SHOULD LARGELY SLIDE BY
JUST TO OUR NORTHEAST.
PREV DISCUSSION... /ISSUED 414 AM CST SUN JAN 20 2013/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. PRIMARY FORECAST
CONCERN LIES WITH TEMPERATURES.
QUIET CONDITIONS REMAIN IN PLACE ACROSS THE REGION EARLY THIS
MORNING...WITH SATELLITE AND UPPER AIR PROFILER DATA SHOWING
NORTHWESTERLY FLOW IN PLACE. RIDGING CONTINUES ALONG THE WEST
COAST...WHILE A COUPLE OF DISTURBANCES WORK THEIR WAY THROUGH THE
NWRLY FLOW...ONE OVER THE GREAT LAKES REGION AND THE OTHER OVER SC
CANADA. AT THE SURFACE...HIGH PRESSURE CONTINUES TO SLIDE SOUTH
OUT OF THE DAKOTAS INTO THE AREA...BEHIND A COLD FRONT WHICH
PASSED THROUGH THE REGION LATE SAT AFTN/EVENING. WITH TIME...WINDS
HAVE GRADUALLY BECOME MORE EASTERLY ACROSS THE CWA...AND HAVE
DIMINISHED IN SPEED.
LOOKING AT THE REST OF TODAY AND INTO MONDAY...THE MAIN STORY LIES
WITH THE PASSAGE OF YET ANOTHER COLD FRONT...AND ITS AFFECT ON
TEMPERATURES. MODELS REMAIN IN GOOD AGREEMENT SHOWING THE ABOVE
MENTIONED UPPER LEVEL DISTURBANCE OVER SC CANADA CONTINUING TO
SLIDE SOUTHEAST THROUGH THE DAY TODAY...WITH THE TIMING OF THE
ACCOMPANYING SFC COLD FRONT/NORTHWESTERLY WINDS STILL EXPECTED TO
PASS THROUGH THE CWA DURING THE AFTERNOON HOURS. THE TIMING MAKES
TEMPERATURES TODAY PRETTY DIFFICULT...ESP WITH MODELS/GUIDANCE NOT
IN VERY GOOD AGREEMENT...MAINLY FOR THOSE NORTHWESTERN PORTIONS OF
THE CWA...WHICH WILL PROB SEE THEIR HIGHS CLOSER TO MIDDAY/EARLY
AFTN VS MID AFTN FURTHER SOUTH. OVERALL DIDNT MAKE MANY CHANGES TO
THE INHERITED FORECAST...WHICH CONTINUES TO CALL FOR GENERALLY MID
30S ACROSS SC NEB...WITH LOWER 40S IN NC KS. CERTAINLY SOMETHING
FOR THE DAYSHIFT TO KEEP AN EYE ON.
AS FAR AS THE POSSIBILITY OF FLURRIES GOES...DECIDED TO KEEP THE
MENTION OUT OF THE FORECAST. AS THAT DISTURBANCE SWINGS SOUTH...IT
WILL BRING ALONG MORE CLOUD COVER AND COLDER TEMPERATURES...AND
WHILE MODELS DO SHOW SOME BATCHES OF INCREASED LOWER LEVEL /BELOW
700MB/ MOISTURE MOVING INTO THE REGION...MAINLY THIS
AFTERNOON...THERE IS ALSO PRETTY GOOD AGREEMENT WITH KEEPING THE
BETTER RH AND COLDER TEMPS MORE FAVORABLE FOR FLURRIES
NORTH/NORTHEAST OF THE CWA...BARELY. THE OPER NAM/GFS/EC CONTINUE
TO SHOW THE CWA DRY...AS DOES THE HRRR. THE RAP AND ONE RUN OF THE
4 KM SHOW PERHAPS THE FAR N/NE EDGE OF THE CWA MAYBE SEEING A
FEW...BUT AM GOING TO CONTINUE TO EXCLUDE THE MENTION.
REALLY THE BRUNT OF THE COLDER AIR HOLDS OFF FROM MOVING INTO THE
CWA UNTIL LATER TODAY AND MAINLY THIS EVENING/TONIGHT. AS HAS BEEN
THE CASE OVER THE PAST FEW DAYS...MODELS CONTINUE TO SHOW THE
MAIN AXIS OF THE TROUGH...AND THUS THE COLDEST AIR...SETTING UP
JUST EAST OF THE CWA TONIGHT/THROUGH MONDAY. WHILE THE CWA MAY
CATCH A BRIEF BREAK FROM CLOUD COVER TONIGHT...EXPECTING TO SEE
ADDITIONAL CLOUD COVER /MAINLY UPPER LEVEL/ STREAMING IN FROM THE
NORTHWEST...KEEPING MAINLY THE NORTHEASTERN HALF OF THE CWA UNDER
PARTLY/MOSTLY CLOUDY SKIES ON MONDAY. DIDNT MAKE ANY NOTABLE
CHANGES TO MONDAYS HIGHS...WHICH RANGE FROM THE LOWER 20S IN THE
NORTHEAST TO LOWER 30S IN THE SOUTHWEST. SURFACE HIGH PRESSURE
SLIDING IN FROM THE NORTHWEST WILL BRING FAIRLY LIGHT WINDS FOR
MOST LOCATIONS.
MONDAY NIGHT THROUGH TUESDAY...THE MAIN UPPER LEVEL TROUGH/COLDEST
AIR ALREADY STARTS ITS EASTWARD SHIFT MONDAY NIGHT...WHICH WILL
BRING A REBOUND IN TEMPS FOR TUESDAY. THE POSSIBILITY OF GETTING
CLIPPED IN THE NORTH BY MORE FLURRIES OR LIGHT SNOW WILL BE
SOMETHING TO CONSIDER WITH UPCOMING MODEL RUNS. CURRENTLY AM
KEEPING THE MENTION OUT OF THE FORECAST...WITH MODELS SHOWING THE
COLDER TEMPS AND BETTER POTENTIAL /MAINLY MONDAY NIGHT INTO THE
FIRST HALF OF TUESDAY/...DRIVEN BY A STRONG UPPER LEVEL JET
STREAK NOSING IN FROM THE N/NW...REMAINING ONCE AGAIN JUST OUTSIDE
THE N/NE EDGE OF THE CWA. WITH THE WARMER AIR STARTING TO BUILD
BACK IN FROM THE WEST...HIGHS CURRENTLY RANGE FROM THE UPPER 20S
IN THE NORTHEAST TO LOWER 40S IN THE WEST...AND SOME MODELS
SUGGEST THE WEST SHOULD BE WARMER. OVERNIGHT LOWS EXPECTED TO
REBOUND FROM THE SINGLE DIGITS/TEENS MONDAY NIGHT TO THE
TEENS/NEAR 20 TUESDAY NIGHT.
LONG TERM...(WEDNESDAY THRU SATURDAY)
THE MAIN STORY: BONE DRY PATTERN CONTINUES WITH RE-AMPLIFYING NW
FLOW STUNTING TEMP RECOVERY...BUT SIGNALS CONTINUE FOR SOME PRECIP
POTENTIAL VERY LATE THIS MONTH.
PATTERN: THE HIGHLY AMPLIFIED WRN N AMERICA RIDGE/ERN TROF WILL
MEET ITS DEMISE NEXT WEEK AS A PACIFIC SHRTWV TROF MOVES ONSHORE
IN THE PAC NW WED AND MOVES THRU THE RIDGE. AS THIS TROF MOVES
INTO THE LGWV TROF THU-FRI...THE PATTERN WILL RE-AMPLIFY
SOMEWHAT...CURBING OUR WARM-UP FRI-SAT. RIDGING THEN ADVANCES OVER
THE PLAINS NEXT WEEKEND...FOLLOWED BY LOWERING HGTS OVER WRN N
AMERICA THE LAST WEEK OF JAN...SUGGESTING A PERIOD OF STORMINESS
AND PCPN POTENTIAL.
MODELS: THERE IS GOOD AGREEMENT AMONGST THE 00Z EC/GFS/GEM ON THIS
SCENARIO THRU 00Z/SAT. THE ONE CAVEAT...THE OPERATIONAL 18Z/00Z GFS
ARE NOT AS AMPLIFIED WITH THE TEMPORARILY REINVIGORATED RIDING OVER
WRN N AMERICA. IN FACT...THE GFS ENSEMBLE MEAN IS CLOSER TO THE
MORE AMPLIFIED 12Z/00Z EC CYCLES. THIS FCST INCORPORATES
EC/GFS/GEM/HPC GUIDANCE THRU 00Z/SAT. BEYOND THAT ITS HPC/EC AND
EC/GFS ENSEMBLE MEANS.
TEMPS: ESSENTIALLY NEAR NORMAL THRU SAT WITH ONE DAY OF BELOW
NORMAL FRI.
HAZARDS: NONE ENVISIONED ATTM.
UPCOMING PCPN OPPORTUNITIES: NOTHING NOTABLE THRU AT LEAST SAT AND
PROBABLY TO MON 1/28. HOWEVER...ODDS ARE INCREASING FOR A MDT
PCPN EVENT AS WE CLOSE THE BOOKS ON JAN.
THE DAILY DETAILS...
WED: M/SUNNY. PROBABLY NEAR NORMAL TEMPS. LEE TROF INTENSIFIES
WITH TROF MOVING INTO PAC NW...AIDING IN MODEST TEMP RECOVERY.
TEMP CONFIDENCE GRAPHICS SHOW ABOVE NORMAL SPREAD IN TEMPS.
THU: P/CLOUDY. A DRY COLD FRONTAL PASSAGE IN THE PRE-DAWN HRS. LOW
PRES EJECTS OUT OF CO ACROSS KS/OK. SOME DIFF/S IN TIMING REMAIN
WITH THE EC/GEM FASTER AND MORE POTENT THAN THE GFS. THE 00Z EC
ENSEMBLES HAVE COME INTO MUCH BETTER AGREEMENT ON SLP SINCE ITS
12Z RUN. HPC IS IN AGREEMENT SO WE/LL ROLL WITH THIS SCENARIO.
ABOVE NORMAL UNCERTAINTY IN TEMPS.
THU HAS POTENTIAL TO BE A BREEZY DAY. HOWEVER...SOME BAGGINESS IN
THE PRES TROF OF A REINFORCING SHOT OF COLD AIR COULD MITIGATE.
THU NGT: ANOTHER PUSH OF COLDER AIR MOVES THRU AS THE SHRTWV TROF
PASSES...BUT THE WORST OF IT REMAINS OFF TO THE N AND E.
FRI: P/CLOUDY. ARCTIC HIGH PRES EXPANDS OVER THE MS VALLEY. IF THE
EC IS RIGHT ANOTHER WEAK LOW MOVES THRU DELIVERING ANOTHER PUSH OF
MARGINALLY COLD AIR. CONFIDENCE IS ABOVE NORMAL ON A COOL DOWN.
TEMPS PROBABLY CLOSE TO 10F BELOW NORMAL.
SAT: SUNNY AS YET ANOTHER ARCTIC HIGH EXPANDS OVER THE MS VALLEY.
HGTS BEGIN RISING AS BROAD RIDGING ADVANCES TOWARD THE PLAINS. WAA
BEGINS WITH A NEW LEE TROF DEVELOPING.
BEYOND SAT...
A VERY NICE WARM-UP COMMENCES SUN THAT COULD LINGER INTO EARLY THE
FOLLOWING WEEK 1/28-29 DEPENDENT ON HOW THE PATTERN SHAPES UP.
WE COULD SEE 1 OR 2 DAYS OF MUCH ABOVE NORMAL TEMPS (+10F OR
MORE). IF WE ROLL WITH THE OPERATIONAL EC AND THE EC/GFS ENSEMBLES
LATE THIS WEEK...THEN WE MUST GO SLOWER THAN THE OPERATIONAL GFS
FOR EARLY THE FOLLOWING WEEK. THE GREATER AMPLIFIED SCENARIO WILL
SLOW THINGS DOWN UPSTREAM. EITHER WAY...THE NEXT PAC TROF WILL DIG
INTO THE DESERT SW THE LAST WEEK OF JAN. THIS IS A FAVORABLE SETUP
FOR A DECENT PCPN EVENT HERE AND WITH THE LOW TRACKING S OF THE
FCST AREA...THIS COULD END UP BEING THE WINTRY VARIETY. HOPEFULLY
WE/LL HAVE TIME TO ENTRAIN GOOD MSTR AFTER MULTIPLE EPISODES OF
CONTINENTAL POLAR AIR HAVE PLUNGED INTO THE GULF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION/UPDATE...PFANNKUCH
SHORT TERM...ADO
LONG TERM...HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1046 AM CST SUN JAN 20 2013
.UPDATE...FOR NOT HAVING HIGH IMPACT WEATHER...TODAY/S FORECAST
REMAINS CHALLENGING ESPECIALLY REGARDING TEMPERATURE TRENDS.
ALTHOUGH CONFIDENCE IN THE HOURLY DETAILS REMAINS SOMEWHAT BELOW
AVERAGE...THE OVERALL MESSAGE FROM VARIOUS MODEL/GUIDANCE SOURCES
SUCH AS HRRR...RAP AND GFS LAMP STRONGLY SUGGESTED THAT PREVIOUS
HIGHS WERE AT LEAST A BIT TOO WARM. AS A RESULT...TRIMMED AT LEAST
1-2 DEGREES OFF HIGHS FOR GENERALLY THE SOUTHWESTERN 2/3 OF THE
CWA...BUT MADE MORE SIGNIFICANT 5-7 DEGREE CUTS TO ESPECIALLY THE
NORTHEAST 1/4 OF OUR AREA...OR ESPECIALLY NORTHEAST OF AN ORD-YORK
LINE. IN THESE NORTHEAST AREAS...TEMPS WILL BE LUCKY TO REACH THE
MID-UPPER 20S...WHILE AT LEAST LOW-MID 30S STILL LOOK POSSIBLE
ACROSS MOST OF THE REMAINDER OF OUR NEB ZONES. KS ZONES COULD
STILL MAKE A RUN AT THE LOW 40S...ALTHOUGH EVEN HERE MAY CONSIDER
LOWERING A BIT IN A FUTURE UPDATE. OTHERWISE...A GENERALLY LIGHT
AND VARIABLE WIND REGIME WILL REMAIN IN PLACE ALL AREAS UNTIL AT
LEAST EARLY AFTERNOON...BUT THEREAFTER A GRADUAL INCREASE IN
NORTHERLY SPEEDS WILL START OVERTAKING THE CWA FROM WEST TO
EAST...WITH AT LEAST A SHORT PERIOD OF 20+ MPH GUSTS EXPECTED TO
AFFECT MOST ALL AREAS BY MID-LATE AFTERNOON. PRECIP-WISE...WILL
CONTINUE TO LEAVE FLURRIES OUT OF THIS AFTERNOON/S FORECAST FOR
OUR FAR NORTHEAST COUNTIES...AS RADAR TRENDS AND SHORT TERM MODELS
CONTINUE TO SUGGEST THAT ANY SUCH ACTIVITY SHOULD LARGELY SLIDE BY
JUST TO OUR NORTHEAST.
&&
.PREV DISCUSSION... /ISSUED 603 AM CST SUN JAN 20 2013/
AVIATION.../12Z GRI TAF THROUGH 12Z MONDAY MORNING/
EARLY THIS MRNG: VFR WITH MULTIPLE LAYERS OF MID-HIGH CIGS ABOVE
15K FT. HOWEVER...SATELLITE AND SFC OBS INDICATE IFR/LOW-END MVFR
STRATUS DEVELOPING ALONG A FRONT 100 SM W OF GRI. HAVE INDICATED
SCT015 BEGINNING AT 12Z TO ACCOUNT FOR WHAT WE BELIEVE WILL BE AN
EVENTUAL DECAY TO MVFR CIGS.
TODAY: WITH THE ON-GOING DEVELOPMENT OF STRATUS...CONFIDENCE HAS
INCREASED IN MVFR CIGS AND LATEST FCST SOUNDINGS ARE SUPPORTIVE.
SO MVFR CIGS ARE NOW IN THE TAF. THERE IS A LOW PROB FOR A PERIOD
OF IFR CIGS. WINDS WILL REMAIN LIGHT AND VARIABLE UNTIL ARCTIC
FROPA...WITHIN AN HOUR OR TWO OF 19Z. AFTER FROPA...EXPECT A WSHFT
TO N WITH GUSTS UP TO 20 KTS. THERE IS ALSO POTENTIAL FOR CIGS TO
IMPROVE TO 3500 FT.
TNGT: FCST SOUNDINGS CONTINUE TO INDICATE POTENTIAL FOR MVFR CIGS.
NOT ALL FCST GUIDANCE AGREES WHICH LOWERS CONFIDENCE. SOME
GUSTINESS CONTINUES INTO THE EVNG...THEN NNW WINDS SHOULD SETTLE
AROUND 8 KTS.
CIG CONFIDENCE: AVERAGE
VSBY CONFIDENCE: HIGH
WIND CONFIDENCE: AVERAGE. EXACT TIME OF FROPA UNCERTAIN. ALSO
UNSURE OF DEGREE OF GUSTINESS POST-FROPA.
WX CONFIDENCE: HIGH
PREV DISCUSSION... /ISSUED 414 AM CST SUN JAN 20 2013/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. PRIMARY FORECAST
CONCERN LIES WITH TEMPERATURES.
QUIET CONDITIONS REMAIN IN PLACE ACROSS THE REGION EARLY THIS
MORNING...WITH SATELLITE AND UPPER AIR PROFILER DATA SHOWING
NORTHWESTERLY FLOW IN PLACE. RIDGING CONTINUES ALONG THE WEST
COAST...WHILE A COUPLE OF DISTURBANCES WORK THEIR WAY THROUGH THE
NWRLY FLOW...ONE OVER THE GREAT LAKES REGION AND THE OTHER OVER SC
CANADA. AT THE SURFACE...HIGH PRESSURE CONTINUES TO SLIDE SOUTH
OUT OF THE DAKOTAS INTO THE AREA...BEHIND A COLD FRONT WHICH
PASSED THROUGH THE REGION LATE SAT AFTN/EVENING. WITH TIME...WINDS
HAVE GRADUALLY BECOME MORE EASTERLY ACROSS THE CWA...AND HAVE
DIMINISHED IN SPEED.
LOOKING AT THE REST OF TODAY AND INTO MONDAY...THE MAIN STORY LIES
WITH THE PASSAGE OF YET ANOTHER COLD FRONT...AND ITS AFFECT ON
TEMPERATURES. MODELS REMAIN IN GOOD AGREEMENT SHOWING THE ABOVE
MENTIONED UPPER LEVEL DISTURBANCE OVER SC CANADA CONTINUING TO
SLIDE SOUTHEAST THROUGH THE DAY TODAY...WITH THE TIMING OF THE
ACCOMPANYING SFC COLD FRONT/NORTHWESTERLY WINDS STILL EXPECTED TO
PASS THROUGH THE CWA DURING THE AFTERNOON HOURS. THE TIMING MAKES
TEMPERATURES TODAY PRETTY DIFFICULT...ESP WITH MODELS/GUIDANCE NOT
IN VERY GOOD AGREEMENT...MAINLY FOR THOSE NORTHWESTERN PORTIONS OF
THE CWA...WHICH WILL PROB SEE THEIR HIGHS CLOSER TO MIDDAY/EARLY
AFTN VS MID AFTN FURTHER SOUTH. OVERALL DIDNT MAKE MANY CHANGES TO
THE INHERITED FORECAST...WHICH CONTINUES TO CALL FOR GENERALLY MID
30S ACROSS SC NEB...WITH LOWER 40S IN NC KS. CERTAINLY SOMETHING
FOR THE DAYSHIFT TO KEEP AN EYE ON.
AS FAR AS THE POSSIBILITY OF FLURRIES GOES...DECIDED TO KEEP THE
MENTION OUT OF THE FORECAST. AS THAT DISTURBANCE SWINGS SOUTH...IT
WILL BRING ALONG MORE CLOUD COVER AND COLDER TEMPERATURES...AND
WHILE MODELS DO SHOW SOME BATCHES OF INCREASED LOWER LEVEL /BELOW
700MB/ MOISTURE MOVING INTO THE REGION...MAINLY THIS
AFTERNOON...THERE IS ALSO PRETTY GOOD AGREEMENT WITH KEEPING THE
BETTER RH AND COLDER TEMPS MORE FAVORABLE FOR FLURRIES
NORTH/NORTHEAST OF THE CWA...BARELY. THE OPER NAM/GFS/EC CONTINUE
TO SHOW THE CWA DRY...AS DOES THE HRRR. THE RAP AND ONE RUN OF THE
4 KM SHOW PERHAPS THE FAR N/NE EDGE OF THE CWA MAYBE SEEING A
FEW...BUT AM GOING TO CONTINUE TO EXCLUDE THE MENTION.
REALLY THE BRUNT OF THE COLDER AIR HOLDS OFF FROM MOVING INTO THE
CWA UNTIL LATER TODAY AND MAINLY THIS EVENING/TONIGHT. AS HAS BEEN
THE CASE OVER THE PAST FEW DAYS...MODELS CONTINUE TO SHOW THE
MAIN AXIS OF THE TROUGH...AND THUS THE COLDEST AIR...SETTING UP
JUST EAST OF THE CWA TONIGHT/THROUGH MONDAY. WHILE THE CWA MAY
CATCH A BRIEF BREAK FROM CLOUD COVER TONIGHT...EXPECTING TO SEE
ADDITIONAL CLOUD COVER /MAINLY UPPER LEVEL/ STREAMING IN FROM THE
NORTHWEST...KEEPING MAINLY THE NORTHEASTERN HALF OF THE CWA UNDER
PARTLY/MOSTLY CLOUDY SKIES ON MONDAY. DIDNT MAKE ANY NOTABLE
CHANGES TO MONDAYS HIGHS...WHICH RANGE FROM THE LOWER 20S IN THE
NORTHEAST TO LOWER 30S IN THE SOUTHWEST. SURFACE HIGH PRESSURE
SLIDING IN FROM THE NORTHWEST WILL BRING FAIRLY LIGHT WINDS FOR
MOST LOCATIONS.
MONDAY NIGHT THROUGH TUESDAY...THE MAIN UPPER LEVEL TROUGH/COLDEST
AIR ALREADY STARTS ITS EASTWARD SHIFT MONDAY NIGHT...WHICH WILL
BRING A REBOUND IN TEMPS FOR TUESDAY. THE POSSIBILITY OF GETTING
CLIPPED IN THE NORTH BY MORE FLURRIES OR LIGHT SNOW WILL BE
SOMETHING TO CONSIDER WITH UPCOMING MODEL RUNS. CURRENTLY AM
KEEPING THE MENTION OUT OF THE FORECAST...WITH MODELS SHOWING THE
COLDER TEMPS AND BETTER POTENTIAL /MAINLY MONDAY NIGHT INTO THE
FIRST HALF OF TUESDAY/...DRIVEN BY A STRONG UPPER LEVEL JET
STREAK NOSING IN FROM THE N/NW...REMAINING ONCE AGAIN JUST OUTSIDE
THE N/NE EDGE OF THE CWA. WITH THE WARMER AIR STARTING TO BUILD
BACK IN FROM THE WEST...HIGHS CURRENTLY RANGE FROM THE UPPER 20S
IN THE NORTHEAST TO LOWER 40S IN THE WEST...AND SOME MODELS
SUGGEST THE WEST SHOULD BE WARMER. OVERNIGHT LOWS EXPECTED TO
REBOUND FROM THE SINGLE DIGITS/TEENS MONDAY NIGHT TO THE
TEENS/NEAR 20 TUESDAY NIGHT.
LONG TERM...(WEDNESDAY THRU SATURDAY)
THE MAIN STORY: BONE DRY PATTERN CONTINUES WITH RE-AMPLIFYING NW
FLOW STUNTING TEMP RECOVERY...BUT SIGNALS CONTINUE FOR SOME PRECIP
POTENTIAL VERY LATE THIS MONTH.
PATTERN: THE HIGHLY AMPLIFIED WRN N AMERICA RIDGE/ERN TROF WILL
MEET ITS DEMISE NEXT WEEK AS A PACIFIC SHRTWV TROF MOVES ONSHORE
IN THE PAC NW WED AND MOVES THRU THE RIDGE. AS THIS TROF MOVES
INTO THE LGWV TROF THU-FRI...THE PATTERN WILL RE-AMPLIFY
SOMEWHAT...CURBING OUR WARM-UP FRI-SAT. RIDGING THEN ADVANCES OVER
THE PLAINS NEXT WEEKEND...FOLLOWED BY LOWERING HGTS OVER WRN N
AMERICA THE LAST WEEK OF JAN...SUGGESTING A PERIOD OF STORMINESS
AND PCPN POTENTIAL.
MODELS: THERE IS GOOD AGREEMENT AMONGST THE 00Z EC/GFS/GEM ON THIS
SCENARIO THRU 00Z/SAT. THE ONE CAVEAT...THE OPERATIONAL 18Z/00Z GFS
ARE NOT AS AMPLIFIED WITH THE TEMPORARILY REINVIGORATED RIDING OVER
WRN N AMERICA. IN FACT...THE GFS ENSEMBLE MEAN IS CLOSER TO THE
MORE AMPLIFIED 12Z/00Z EC CYCLES. THIS FCST INCORPORATES
EC/GFS/GEM/HPC GUIDANCE THRU 00Z/SAT. BEYOND THAT ITS HPC/EC AND
EC/GFS ENSEMBLE MEANS.
TEMPS: ESSENTIALLY NEAR NORMAL THRU SAT WITH ONE DAY OF BELOW
NORMAL FRI.
HAZARDS: NONE ENVISIONED ATTM.
UPCOMING PCPN OPPORTUNITIES: NOTHING NOTABLE THRU AT LEAST SAT AND
PROBABLY TO MON 1/28. HOWEVER...ODDS ARE INCREASING FOR A MDT
PCPN EVENT AS WE CLOSE THE BOOKS ON JAN.
THE DAILY DETAILS...
WED: M/SUNNY. PROBABLY NEAR NORMAL TEMPS. LEE TROF INTENSIFIES
WITH TROF MOVING INTO PAC NW...AIDING IN MODEST TEMP RECOVERY.
TEMP CONFIDENCE GRAPHICS SHOW ABOVE NORMAL SPREAD IN TEMPS.
THU: P/CLOUDY. A DRY COLD FRONTAL PASSAGE IN THE PRE-DAWN HRS. LOW
PRES EJECTS OUT OF CO ACROSS KS/OK. SOME DIFF/S IN TIMING REMAIN
WITH THE EC/GEM FASTER AND MORE POTENT THAN THE GFS. THE 00Z EC
ENSEMBLES HAVE COME INTO MUCH BETTER AGREEMENT ON SLP SINCE ITS
12Z RUN. HPC IS IN AGREEMENT SO WE/LL ROLL WITH THIS SCENARIO.
ABOVE NORMAL UNCERTAINTY IN TEMPS.
THU HAS POTENTIAL TO BE A BREEZY DAY. HOWEVER...SOME BAGGINESS IN
THE PRES TROF OF A REINFORCING SHOT OF COLD AIR COULD MITIGATE.
THU NGT: ANOTHER PUSH OF COLDER AIR MOVES THRU AS THE SHRTWV TROF
PASSES...BUT THE WORST OF IT REMAINS OFF TO THE N AND E.
FRI: P/CLOUDY. ARCTIC HIGH PRES EXPANDS OVER THE MS VALLEY. IF THE
EC IS RIGHT ANOTHER WEAK LOW MOVES THRU DELIVERING ANOTHER PUSH OF
MARGINALLY COLD AIR. CONFIDENCE IS ABOVE NORMAL ON A COOL DOWN.
TEMPS PROBABLY CLOSE TO 10F BELOW NORMAL.
SAT: SUNNY AS YET ANOTHER ARCTIC HIGH EXPANDS OVER THE MS VALLEY.
HGTS BEGIN RISING AS BROAD RIDGING ADVANCES TOWARD THE PLAINS. WAA
BEGINS WITH A NEW LEE TROF DEVELOPING.
BEYOND SAT...
A VERY NICE WARM-UP COMMENCES SUN THAT COULD LINGER INTO EARLY THE
FOLLOWING WEEK 1/28-29 DEPENDENT ON HOW THE PATTERN SHAPES UP.
WE COULD SEE 1 OR 2 DAYS OF MUCH ABOVE NORMAL TEMPS (+10F OR
MORE). IF WE ROLL WITH THE OPERATIONAL EC AND THE EC/GFS ENSEMBLES
LATE THIS WEEK...THEN WE MUST GO SLOWER THAN THE OPERATIONAL GFS
FOR EARLY THE FOLLOWING WEEK. THE GREATER AMPLIFIED SCENARIO WILL
SLOW THINGS DOWN UPSTREAM. EITHER WAY...THE NEXT PAC TROF WILL DIG
INTO THE DESERT SW THE LAST WEEK OF JAN. THIS IS A FAVORABLE SETUP
FOR A DECENT PCPN EVENT HERE AND WITH THE LOW TRACKING S OF THE
FCST AREA...THIS COULD END UP BEING THE WINTRY VARIETY. HOPEFULLY
WE/LL HAVE TIME TO ENTRAIN GOOD MSTR AFTER MULTIPLE EPISODES OF
CONTINENTAL POLAR AIR HAVE PLUNGED INTO THE GULF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...ADO
LONG TERM/AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
603 AM CST SUN JAN 20 2013
.AVIATION.../12Z GRI TAF THROUGH 12Z MONDAY MORNING/
EARLY THIS MRNG: VFR WITH MULTIPLE LAYERS OF MID-HIGH CIGS ABOVE
15K FT. HOWEVER...SATELLITE AND SFC OBS INDICATE IFR/LOW-END MVFR
STRATUS DEVELOPING ALONG A FRONT 100 SM W OF GRI. HAVE INDICATED
SCT015 BEGINNING AT 12Z TO ACCOUNT FOR WHAT WE BELIEVE WILL BE AN
EVENTUAL DECAY TO MVFR CIGS.
TODAY: WITH THE ON-GOING DEVELOPMENT OF STRATUS...CONFIDENCE HAS
INCREASED IN MVFR CIGS AND LATEST FCST SOUNDINGS ARE SUPPORTIVE.
SO MVFR CIGS ARE NOW IN THE TAF. THERE IS A LOW PROB FOR A PERIOD
OF IFR CIGS. WINDS WILL REMAIN LIGHT AND VARIABLE UNTIL ARCTIC
FROPA...WITHIN AN HOUR OR TWO OF 19Z. AFTER FROPA...EXPECT A WSHFT
TO N WITH GUSTS UP TO 20 KTS. THERE IS ALSO POTENTIAL FOR CIGS TO
IMPROVE TO 3500 FT.
TNGT: FCST SOUNDINGS CONTINUE TO INDICATE POTENTIAL FOR MVFR CIGS.
NOT ALL FCST GUIDANCE AGREES WHICH LOWERS CONFIDENCE. SOME
GUSTINESS CONTINUES INTO THE EVNG...THEN NNW WINDS SHOULD SETTLE
AROUND 8 KTS.
CIG CONFIDENCE: AVERAGE
VSBY CONFIDENCE: HIGH
WIND CONFIDENCE: AVERAGE. EXACT TIME OF FROPA UNCERTAIN. ALSO
UNSURE OF DEGREE OF GUSTINESS POST-FROPA.
WX CONFIDENCE: HIGH
&&
.PREV DISCUSSION... /ISSUED 414 AM CST SUN JAN 20 2013/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. PRIMARY FORECAST
CONCERN LIES WITH TEMPERATURES.
QUIET CONDITIONS REMAIN IN PLACE ACROSS THE REGION EARLY THIS
MORNING...WITH SATELLITE AND UPPER AIR PROFILER DATA SHOWING
NORTHWESTERLY FLOW IN PLACE. RIDGING CONTINUES ALONG THE WEST
COAST...WHILE A COUPLE OF DISTURBANCES WORK THEIR WAY THROUGH THE
NWRLY FLOW...ONE OVER THE GREAT LAKES REGION AND THE OTHER OVER SC
CANADA. AT THE SURFACE...HIGH PRESSURE CONTINUES TO SLIDE SOUTH
OUT OF THE DAKOTAS INTO THE AREA...BEHIND A COLD FRONT WHICH
PASSED THROUGH THE REGION LATE SAT AFTN/EVENING. WITH TIME...WINDS
HAVE GRADUALLY BECOME MORE EASTERLY ACROSS THE CWA...AND HAVE
DIMINISHED IN SPEED.
LOOKING AT THE REST OF TODAY AND INTO MONDAY...THE MAIN STORY LIES
WITH THE PASSAGE OF YET ANOTHER COLD FRONT...AND ITS AFFECT ON
TEMPERATURES. MODELS REMAIN IN GOOD AGREEMENT SHOWING THE ABOVE
MENTIONED UPPER LEVEL DISTURBANCE OVER SC CANADA CONTINUING TO
SLIDE SOUTHEAST THROUGH THE DAY TODAY...WITH THE TIMING OF THE
ACCOMPANYING SFC COLD FRONT/NORTHWESTERLY WINDS STILL EXPECTED TO
PASS THROUGH THE CWA DURING THE AFTERNOON HOURS. THE TIMING MAKES
TEMPERATURES TODAY PRETTY DIFFICULT...ESP WITH MODELS/GUIDANCE NOT
IN VERY GOOD AGREEMENT...MAINLY FOR THOSE NORTHWESTERN PORTIONS OF
THE CWA...WHICH WILL PROB SEE THEIR HIGHS CLOSER TO MIDDAY/EARLY
AFTN VS MID AFTN FURTHER SOUTH. OVERALL DIDNT MAKE MANY CHANGES TO
THE INHERITED FORECAST...WHICH CONTINUES TO CALL FOR GENERALLY MID
30S ACROSS SC NEB...WITH LOWER 40S IN NC KS. CERTAINLY SOMETHING
FOR THE DAYSHIFT TO KEEP AN EYE ON.
AS FAR AS THE POSSIBILITY OF FLURRIES GOES...DECIDED TO KEEP THE
MENTION OUT OF THE FORECAST. AS THAT DISTURBANCE SWINGS SOUTH...IT
WILL BRING ALONG MORE CLOUD COVER AND COLDER TEMPERATURES...AND
WHILE MODELS DO SHOW SOME BATCHES OF INCREASED LOWER LEVEL /BELOW
700MB/ MOISTURE MOVING INTO THE REGION...MAINLY THIS
AFTERNOON...THERE IS ALSO PRETTY GOOD AGREEMENT WITH KEEPING THE
BETTER RH AND COLDER TEMPS MORE FAVORABLE FOR FLURRIES
NORTH/NORTHEAST OF THE CWA...BARELY. THE OPER NAM/GFS/EC CONTINUE
TO SHOW THE CWA DRY...AS DOES THE HRRR. THE RAP AND ONE RUN OF THE
4 KM SHOW PERHAPS THE FAR N/NE EDGE OF THE CWA MAYBE SEEING A
FEW...BUT AM GOING TO CONTINUE TO EXCLUDE THE MENTION.
REALLY THE BRUNT OF THE COLDER AIR HOLDS OFF FROM MOVING INTO THE
CWA UNTIL LATER TODAY AND MAINLY THIS EVENING/TONIGHT. AS HAS BEEN
THE CASE OVER THE PAST FEW DAYS...MODELS CONTINUE TO SHOW THE
MAIN AXIS OF THE TROUGH...AND THUS THE COLDEST AIR...SETTING UP
JUST EAST OF THE CWA TONIGHT/THROUGH MONDAY. WHILE THE CWA MAY
CATCH A BRIEF BREAK FROM CLOUD COVER TONIGHT...EXPECTING TO SEE
ADDITIONAL CLOUD COVER /MAINLY UPPER LEVEL/ STREAMING IN FROM THE
NORTHWEST...KEEPING MAINLY THE NORTHEASTERN HALF OF THE CWA UNDER
PARTLY/MOSTLY CLOUDY SKIES ON MONDAY. DIDNT MAKE ANY NOTABLE
CHANGES TO MONDAYS HIGHS...WHICH RANGE FROM THE LOWER 20S IN THE
NORTHEAST TO LOWER 30S IN THE SOUTHWEST. SURFACE HIGH PRESSURE
SLIDING IN FROM THE NORTHWEST WILL BRING FAIRLY LIGHT WINDS FOR
MOST LOCATIONS.
MONDAY NIGHT THROUGH TUESDAY...THE MAIN UPPER LEVEL TROUGH/COLDEST
AIR ALREADY STARTS ITS EASTWARD SHIFT MONDAY NIGHT...WHICH WILL
BRING A REBOUND IN TEMPS FOR TUESDAY. THE POSSIBILITY OF GETTING
CLIPPED IN THE NORTH BY MORE FLURRIES OR LIGHT SNOW WILL BE
SOMETHING TO CONSIDER WITH UPCOMING MODEL RUNS. CURRENTLY AM
KEEPING THE MENTION OUT OF THE FORECAST...WITH MODELS SHOWING THE
COLDER TEMPS AND BETTER POTENTIAL /MAINLY MONDAY NIGHT INTO THE
FIRST HALF OF TUESDAY/...DRIVEN BY A STRONG UPPER LEVEL JET
STREAK NOSING IN FROM THE N/NW...REMAINING ONCE AGAIN JUST OUTSIDE
THE N/NE EDGE OF THE CWA. WITH THE WARMER AIR STARTING TO BUILD
BACK IN FROM THE WEST...HIGHS CURRENTLY RANGE FROM THE UPPER 20S
IN THE NORTHEAST TO LOWER 40S IN THE WEST...AND SOME MODELS
SUGGEST THE WEST SHOULD BE WARMER. OVERNIGHT LOWS EXPECTED TO
REBOUND FROM THE SINGLE DIGITS/TEENS MONDAY NIGHT TO THE
TEENS/NEAR 20 TUESDAY NIGHT.
LONG TERM...(WEDNESDAY THRU SATURDAY)
THE MAIN STORY: BONE DRY PATTERN CONTINUES WITH RE-AMPLIFYING NW
FLOW STUNTING TEMP RECOVERY...BUT SIGNALS CONTINUE FOR SOME PRECIP
POTENTIAL VERY LATE THIS MONTH.
PATTERN: THE HIGHLY AMPLIFIED WRN N AMERICA RIDGE/ERN TROF WILL
MEET ITS DEMISE NEXT WEEK AS A PACIFIC SHRTWV TROF MOVES ONSHORE
IN THE PAC NW WED AND MOVES THRU THE RIDGE. AS THIS TROF MOVES
INTO THE LGWV TROF THU-FRI...THE PATTERN WILL RE-AMPLIFY
SOMEWHAT...CURBING OUR WARM-UP FRI-SAT. RIDGING THEN ADVANCES OVER
THE PLAINS NEXT WEEKEND...FOLLOWED BY LOWERING HGTS OVER WRN N
AMERICA THE LAST WEEK OF JAN...SUGGESTING A PERIOD OF STORMINESS
AND PCPN POTENTIAL.
MODELS: THERE IS GOOD AGREEMENT AMONGST THE 00Z EC/GFS/GEM ON THIS
SCENARIO THRU 00Z/SAT. THE ONE CAVEAT...THE OPERATIONAL 18Z/00Z GFS
ARE NOT AS AMPLIFIED WITH THE TEMPORARILY REINVIGORATED RIDING OVER
WRN N AMERICA. IN FACT...THE GFS ENSEMBLE MEAN IS CLOSER TO THE
MORE AMPLIFIED 12Z/00Z EC CYCLES. THIS FCST INCORPORATES
EC/GFS/GEM/HPC GUIDANCE THRU 00Z/SAT. BEYOND THAT ITS HPC/EC AND
EC/GFS ENSEMBLE MEANS.
TEMPS: ESSENTIALLY NEAR NORMAL THRU SAT WITH ONE DAY OF BELOW
NORMAL FRI.
HAZARDS: NONE ENVISIONED ATTM.
UPCOMING PCPN OPPORTUNITIES: NOTHING NOTABLE THRU AT LEAST SAT AND
PROBABLY TO MON 1/28. HOWEVER...ODDS ARE INCREASING FOR A MDT
PCPN EVENT AS WE CLOSE THE BOOKS ON JAN.
THE DAILY DETAILS...
WED: M/SUNNY. PROBABLY NEAR NORMAL TEMPS. LEE TROF INTENSIFIES
WITH TROF MOVING INTO PAC NW...AIDING IN MODEST TEMP RECOVERY.
TEMP CONFIDENCE GRAPHICS SHOW ABOVE NORMAL SPREAD IN TEMPS.
THU: P/CLOUDY. A DRY COLD FRONTAL PASSAGE IN THE PRE-DAWN HRS. LOW
PRES EJECTS OUT OF CO ACROSS KS/OK. SOME DIFF/S IN TIMING REMAIN
WITH THE EC/GEM FASTER AND MORE POTENT THAN THE GFS. THE 00Z EC
ENSEMBLES HAVE COME INTO MUCH BETTER AGREEMENT ON SLP SINCE ITS
12Z RUN. HPC IS IN AGREEMENT SO WE/LL ROLL WITH THIS SCENARIO.
ABOVE NORMAL UNCERTAINTY IN TEMPS.
THU HAS POTENTIAL TO BE A BREEZY DAY. HOWEVER...SOME BAGGINESS IN
THE PRES TROF OF A REINFORCING SHOT OF COLD AIR COULD MITIGATE.
THU NGT: ANOTHER PUSH OF COLDER AIR MOVES THRU AS THE SHRTWV TROF
PASSES...BUT THE WORST OF IT REMAINS OFF TO THE N AND E.
FRI: P/CLOUDY. ARCTIC HIGH PRES EXPANDS OVER THE MS VALLEY. IF THE
EC IS RIGHT ANOTHER WEAK LOW MOVES THRU DELIVERING ANOTHER PUSH OF
MARGINALLY COLD AIR. CONFIDENCE IS ABOVE NORMAL ON A COOL DOWN.
TEMPS PROBABLY CLOSE TO 10F BELOW NORMAL.
SAT: SUNNY AS YET ANOTHER ARCTIC HIGH EXPANDS OVER THE MS VALLEY.
HGTS BEGIN RISING AS BROAD RIDGING ADVANCES TOWARD THE PLAINS. WAA
BEGINS WITH A NEW LEE TROF DEVELOPING.
BEYOND SAT...
A VERY NICE WARM-UP COMMENCES SUN THAT COULD LINGER INTO EARLY THE
FOLLOWING WEEK 1/28-29 DEPENDENT ON HOW THE PATTERN SHAPES UP.
WE COULD SEE 1 OR 2 DAYS OF MUCH ABOVE NORMAL TEMPS (+10F OR
MORE). IF WE ROLL WITH THE OPERATIONAL EC AND THE EC/GFS ENSEMBLES
LATE THIS WEEK...THEN WE MUST GO SLOWER THAN THE OPERATIONAL GFS
FOR EARLY THE FOLLOWING WEEK. THE GREATER AMPLIFIED SCENARIO WILL
SLOW THINGS DOWN UPSTREAM. EITHER WAY...THE NEXT PAC TROF WILL DIG
INTO THE DESERT SW THE LAST WEEK OF JAN. THIS IS A FAVORABLE SETUP
FOR A DECENT PCPN EVENT HERE AND WITH THE LOW TRACKING S OF THE
FCST AREA...THIS COULD END UP BEING THE WINTRY VARIETY. HOPEFULLY
WE/LL HAVE TIME TO ENTRAIN GOOD MSTR AFTER MULTIPLE EPISODES OF
CONTINENTAL POLAR AIR HAVE PLUNGED INTO THE GULF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...HALBLAUB
SHORT TERM...ADO
LONG TERM...HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
414 AM CST SUN JAN 20 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT. PRIMARY FORECAST
CONCERN LIES WITH TEMPERATURES.
QUIET CONDITIONS REMAIN IN PLACE ACROSS THE REGION EARLY THIS
MORNING...WITH SATELLITE AND UPPER AIR PROFILER DATA SHOWING
NORTHWESTERLY FLOW IN PLACE. RIDGING CONTINUES ALONG THE WEST
COAST...WHILE A COUPLE OF DISTURBANCES WORK THEIR WAY THROUGH THE
NWRLY FLOW...ONE OVER THE GREAT LAKES REGION AND THE OTHER OVER SC
CANADA. AT THE SURFACE...HIGH PRESSURE CONTINUES TO SLIDE SOUTH
OUT OF THE DAKOTAS INTO THE AREA...BEHIND A COLD FRONT WHICH
PASSED THROUGH THE REGION LATE SAT AFTN/EVENING. WITH TIME...WINDS
HAVE GRADUALLY BECOME MORE EASTERLY ACROSS THE CWA...AND HAVE
DIMINISHED IN SPEED.
LOOKING AT THE REST OF TODAY AND INTO MONDAY...THE MAIN STORY LIES
WITH THE PASSAGE OF YET ANOTHER COLD FRONT...AND ITS AFFECT ON
TEMPERATURES. MODELS REMAIN IN GOOD AGREEMENT SHOWING THE ABOVE
MENTIONED UPPER LEVEL DISTURBANCE OVER SC CANADA CONTINUING TO
SLIDE SOUTHEAST THROUGH THE DAY TODAY...WITH THE TIMING OF THE
ACCOMPANYING SFC COLD FRONT/NORTHWESTERLY WINDS STILL EXPECTED TO
PASS THROUGH THE CWA DURING THE AFTERNOON HOURS. THE TIMING MAKES
TEMPERATURES TODAY PRETTY DIFFICULT...ESP WITH MODELS/GUIDANCE NOT
IN VERY GOOD AGREEMENT...MAINLY FOR THOSE NORTHWESTERN PORTIONS OF
THE CWA...WHICH WILL PROB SEE THEIR HIGHS CLOSER TO MIDDAY/EARLY
AFTN VS MID AFTN FURTHER SOUTH. OVERALL DIDNT MAKE MANY CHANGES TO
THE INHERITED FORECAST...WHICH CONTINUES TO CALL FOR GENERALLY MID
30S ACROSS SC NEB...WITH LOWER 40S IN NC KS. CERTAINLY SOMETHING
FOR THE DAYSHIFT TO KEEP AN EYE ON.
AS FAR AS THE POSSIBILITY OF FLURRIES GOES...DECIDED TO KEEP THE
MENTION OUT OF THE FORECAST. AS THAT DISTURBANCE SWINGS SOUTH...IT
WILL BRING ALONG MORE CLOUD COVER AND COLDER TEMPERATURES...AND
WHILE MODELS DO SHOW SOME BATCHES OF INCREASED LOWER LEVEL /BELOW
700MB/ MOISTURE MOVING INTO THE REGION...MAINLY THIS
AFTERNOON...THERE IS ALSO PRETTY GOOD AGREEMENT WITH KEEPING THE
BETTER RH AND COLDER TEMPS MORE FAVORABLE FOR FLURRIES
NORTH/NORTHEAST OF THE CWA...BARELY. THE OPER NAM/GFS/EC CONTINUE
TO SHOW THE CWA DRY...AS DOES THE HRRR. THE RAP AND ONE RUN OF THE
4 KM SHOW PERHAPS THE FAR N/NE EDGE OF THE CWA MAYBE SEEING A
FEW...BUT AM GOING TO CONTINUE TO EXCLUDE THE MENTION.
REALLY THE BRUNT OF THE COLDER AIR HOLDS OFF FROM MOVING INTO THE
CWA UNTIL LATER TODAY AND MAINLY THIS EVENING/TONIGHT. AS HAS BEEN
THE CASE OVER THE PAST FEW DAYS...MODELS CONTINUE TO SHOW THE
MAIN AXIS OF THE TROUGH...AND THUS THE COLDEST AIR...SETTING UP
JUST EAST OF THE CWA TONIGHT/THROUGH MONDAY. WHILE THE CWA MAY
CATCH A BRIEF BREAK FROM CLOUD COVER TONIGHT...EXPECTING TO SEE
ADDITIONAL CLOUD COVER /MAINLY UPPER LEVEL/ STREAMING IN FROM THE
NORTHWEST...KEEPING MAINLY THE NORTHEASTERN HALF OF THE CWA UNDER
PARTLY/MOSTLY CLOUDY SKIES ON MONDAY. DIDNT MAKE ANY NOTABLE
CHANGES TO MONDAYS HIGHS...WHICH RANGE FROM THE LOWER 20S IN THE
NORTHEAST TO LOWER 30S IN THE SOUTHWEST. SURFACE HIGH PRESSURE
SLIDING IN FROM THE NORTHWEST WILL BRING FAIRLY LIGHT WINDS FOR
MOST LOCATIONS.
MONDAY NIGHT THROUGH TUESDAY...THE MAIN UPPER LEVEL TROUGH/COLDEST
AIR ALREADY STARTS ITS EASTWARD SHIFT MONDAY NIGHT...WHICH WILL
BRING A REBOUND IN TEMPS FOR TUESDAY. THE POSSIBILITY OF GETTING
CLIPPED IN THE NORTH BY MORE FLURRIES OR LIGHT SNOW WILL BE
SOMETHING TO CONSIDER WITH UPCOMING MODEL RUNS. CURRENTLY AM
KEEPING THE MENTION OUT OF THE FORECAST...WITH MODELS SHOWING THE
COLDER TEMPS AND BETTER POTENTIAL /MAINLY MONDAY NIGHT INTO THE
FIRST HALF OF TUESDAY/...DRIVEN BY A STRONG UPPER LEVEL JET
STREAK NOSING IN FROM THE N/NW...REMAINING ONCE AGAIN JUST OUTSIDE
THE N/NE EDGE OF THE CWA. WITH THE WARMER AIR STARTING TO BUILD
BACK IN FROM THE WEST...HIGHS CURRENTLY RANGE FROM THE UPPER 20S
IN THE NORTHEAST TO LOWER 40S IN THE WEST...AND SOME MODELS
SUGGEST THE WEST SHOULD BE WARMER. OVERNIGHT LOWS EXPECTED TO
REBOUND FROM THE SINGLE DIGITS/TEENS MONDAY NIGHT TO THE
TEENS/NEAR 20 TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THRU SATURDAY)
THE MAIN STORY: BONE DRY PATTERN CONTINUES WITH RE-AMPLIFYING NW
FLOW STUNTING TEMP RECOVERY...BUT SIGNALS CONTINUE FOR SOME PRECIP
POTENTIAL VERY LATE THIS MONTH.
PATTERN: THE HIGHLY AMPLIFIED WRN N AMERICA RIDGE/ERN TROF WILL
MEET ITS DEMISE NEXT WEEK AS A PACIFIC SHRTWV TROF MOVES ONSHORE
IN THE PAC NW WED AND MOVES THRU THE RIDGE. AS THIS TROF MOVES
INTO THE LGWV TROF THU-FRI...THE PATTERN WILL RE-AMPLIFY
SOMEWHAT...CURBING OUR WARM-UP FRI-SAT. RIDGING THEN ADVANCES OVER
THE PLAINS NEXT WEEKEND...FOLLOWED BY LOWERING HGTS OVER WRN N
AMERICA THE LAST WEEK OF JAN...SUGGESTING A PERIOD OF STORMINESS
AND PCPN POTENTIAL.
MODELS: THERE IS GOOD AGREEMENT AMONGST THE 00Z EC/GFS/GEM ON THIS
SCENARIO THRU 00Z/SAT. THE ONE CAVEAT...THE OPERATIONAL 18Z/00Z GFS
ARE NOT AS AMPLIFIED WITH THE TEMPORARILY REINVIGORATED RIDING OVER
WRN N AMERICA. IN FACT...THE GFS ENSEMBLE MEAN IS CLOSER TO THE
MORE AMPLIFIED 12Z/00Z EC CYCLES. THIS FCST INCORPORATES
EC/GFS/GEM/HPC GUIDANCE THRU 00Z/SAT. BEYOND THAT ITS HPC/EC AND
EC/GFS ENSEMBLE MEANS.
TEMPS: ESSENTIALLY NEAR NORMAL THRU SAT WITH ONE DAY OF BELOW
NORMAL FRI.
HAZARDS: NONE ENVISIONED ATTM.
UPCOMING PCPN OPPORTUNITIES: NOTHING NOTABLE THRU AT LEAST SAT AND
PROBABLY TO MON 1/28. HOWEVER...ODDS ARE INCREASING FOR A MDT
PCPN EVENT AS WE CLOSE THE BOOKS ON JAN.
THE DAILY DETAILS...
WED: M/SUNNY. PROBABLY NEAR NORMAL TEMPS. LEE TROF INTENSIFIES
WITH TROF MOVING INTO PAC NW...AIDING IN MODEST TEMP RECOVERY.
TEMP CONFIDENCE GRAPHICS SHOW ABOVE NORMAL SPREAD IN TEMPS.
THU: P/CLOUDY. A DRY COLD FRONTAL PASSAGE IN THE PRE-DAWN HRS. LOW
PRES EJECTS OUT OF CO ACROSS KS/OK. SOME DIFF/S IN TIMING REMAIN
WITH THE EC/GEM FASTER AND MORE POTENT THAN THE GFS. THE 00Z EC
ENSEMBLES HAVE COME INTO MUCH BETTER AGREEMENT ON SLP SINCE ITS
12Z RUN. HPC IS IN AGREEMENT SO WE/LL ROLL WITH THIS SCENARIO.
ABOVE NORMAL UNCERTAINTY IN TEMPS.
THU HAS POTENTIAL TO BE A BREEZY DAY. HOWEVER...SOME BAGGINESS IN
THE PRES TROF OF A REINFORCING SHOT OF COLD AIR COULD MITIGATE.
THU NGT: ANOTHER PUSH OF COLDER AIR MOVES THRU AS THE SHRTWV TROF
PASSES...BUT THE WORST OF IT REMAINS OFF TO THE N AND E.
FRI: P/CLOUDY. ARCTIC HIGH PRES EXPANDS OVER THE MS VALLEY. IF THE
EC IS RIGHT ANOTHER WEAK LOW MOVES THRU DELIVERING ANOTHER PUSH OF
MARGINALLY COLD AIR. CONFIDENCE IS ABOVE NORMAL ON A COOL DOWN.
TEMPS PROBABLY CLOSE TO 10F BELOW NORMAL.
SAT: SUNNY AS YET ANOTHER ARCTIC HIGH EXPANDS OVER THE MS VALLEY.
HGTS BEGIN RISING AS BROAD RIDGING ADVANCES TOWARD THE PLAINS. WAA
BEGINS WITH A NEW LEE TROF DEVELOPING.
BEYOND SAT...
A VERY NICE WARM-UP COMMENCES SUN THAT COULD LINGER INTO EARLY THE
FOLLOWING WEEK 1/28-29 DEPENDENT ON HOW THE PATTERN SHAPES UP.
WE COULD SEE 1 OR 2 DAYS OF MUCH ABOVE NORMAL TEMPS (+10F OR
MORE). IF WE ROLL WITH THE OPERATIONAL EC AND THE EC/GFS ENSEMBLES
LATE THIS WEEK...THEN WE MUST GO SLOWER THAN THE OPERATIONAL GFS
FOR EARLY THE FOLLOWING WEEK. THE GREATER AMPLIFIED SCENARIO WILL
SLOW THINGS DOWN UPSTREAM. EITHER WAY...THE NEXT PAC TROF WILL DIG
INTO THE DESERT SW THE LAST WEEK OF JAN. THIS IS A FAVORABLE SETUP
FOR A DECENT PCPN EVENT HERE AND WITH THE LOW TRACKING S OF THE
FCST AREA...THIS COULD END UP BEING THE WINTRY VARIETY. HOPEFULLY
WE/LL HAVE TIME TO ENTRAIN GOOD MSTR AFTER MULTIPLE EPISODES OF
CONTINENTAL POLAR AIR HAVE PLUNGED INTO THE GULF.
&&
.AVIATION...(06Z GRI TAF THROUGH 06Z SUNDAY NIGHT)
REST OF TNGT: VFR WITH MULTIPLE LAYERS OF MID-HIGH CIGS ABOVE 15K
FT. N WINDS WILL AVERAGE AROUND 10 KTS UNTIL 09Z WHEN WINDS WILL
GRADUALLY VEER TO E AND DECREASE TO 4 KTS OR LESS.
SUN: VFR WITH MULTIPLE MID-HIGH CIGS ABOVE 15K FT. LIGHT WINDS
WILL CONTINUE TO VEER TO SE-S-SW AT 5 KTS OR LESS...AS AN ARCTIC
COLD FRONT APPROACHES AND WEAK LOW PRES MOVES ALONG THE FRONT.
FROPA CURRENTLY EXPECTED 19-21Z. AFTER FROPA...EXPECT A WSHFT TO
N WITH GUSTS UP TO 22 KTS. SHOULD SEE LOW-END VFR OVC035 MOVE IN.
THERE IS A LOW PROB FOR MVFR CIGS.
SUN THRU 06Z: PROBABLY VFR. N-NNW WINDS DIMINISH AROUND 03Z WITH
BKN 3500 FT CIGS CONTINUING. THERE IS A LOW PROB FOR MVFR CIGS.
CIG CONFIDENCE: HIGH THRU 19Z. THEN AVERAGE THEREAFTER.
VSBY CONFIDENCE: HIGH
WIND CONFIDENCE: AVERAGE. EXACT TIME OF FROPA UNCERTAIN. ALSO
UNSURE OF DEGREE OF GUSTINESS POST-FROPA.
WX CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT...ADO
LONG/AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1029 PM EST MON JAN 21 2013
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL TAPER OFF THIS EVENING AS A WEAK AREA
OF LOW PRESSURE TRACKS OUT OF THE REGION. COLDER AIR WILL ARRIVE
ON GUSTY WEST TO NORTHWEST WINDS LATER TONIGHT...WHICH WILL ALLOW LAKE
EFFECT SNOWS TO DEVELOP. THIS ACTIVITY WILL DIMINISH ON THURSDAY
AS HIGH PRESSURE BRIEFLY MOVES INTO THE AREA. OUTSIDE OF THE LAKE
EFFECT SNOW...PARTLY TO MOSTLY CLOUDY SKIES AND SCATTERED SNOW
SHOWERS OR FLURRIES ARE EXPECTED.
&&
.NEAR TERM /THROUGH TUESDAY/...
1020 PM UPDATE...
LATEST HIGH-RES MODELS CONTINUE TO ADVERTISE LAKE BAND DEVELOPMENT
EAST OF LAKE ONTARIO THIS EVENING WITH RECENT RADAR TRENDS FROM BOTH
KBUF AND KTYX NOW SHOWING THE INITIAL STAGES OF BAND DEVELOPMENT.
THAT SAID...WE HAVE ELECTED TO EXTEND THE LAKE EFFECT SNOW WARNING
SOUTH TO INCLUDE ALL ONEIDA COUNTY BEGINNING AT 06Z THIS EVENING.
CONSIDERING THE BANDS ARE FORECAST BY HIGH-RES MODELS TO EXTEND
SOUTH INTO ONONDAGA AND MADISON COUNTIES...HAVE POSTED A LAKE
EFFECT SNOW WATCH FOR ZONES BEGINNING AT 15Z TUE WHERE 5 TO 9
INCHES OF NEW SNOW WILL BE POSSIBLE THROUGH TUE NIGHT. AS STATED
IN THE PREVIOUS UPDATE...MODELS CONTINUE TO SHOW A FAIR AMOUNT OF
BAND MOVEMENT DURING THE DAYLIGHT HOURS WHICH MAY BE A
MANIFESTATION OF CONVECTIVE OVERTURNING DUE TO A STRONGLY UNSTABLE
MIXED LAYER. ONCE THE BAND DOES FORM...WE EXPECT THE FEATURE TO BE
FAIRLY INTENSE WITH HOURLY SNOWFALL RATES OF 1-2"/HR DEFINITELY A
POSSIBILITY CONSIDERING HIGH INVERSION LEVELS (>14 KFT) AND STRONG
INSTABILITY. ELSEWHERE...EVERYTHING REMAINS ON TRACK AND NO MAJOR
ADJUSTMENTS ARE NEEDED AT THIS TIME.
820 PM UPDATE...
EARLIER SNOWS THAT WARRANTED THE ISSUANCE OF A QUICK WINTER WX
ADVISORY HAVE PUSHED EAST AND CONTINUE TO EXIT THE FORECAST AREA
STAGE RIGHT. UPSTREAM RADAR TRENDS FROM KBUF CONTINUE TO SHOW A
HEALTHY LAKE ERIE BAND WHICH HAS LED TO OVER A FOOT OF SNOW IN
LESS THAN 4 HOURS ACROSS PORTIONS OF CHAUTAUQUA COUNTY EARLIER
THIS EVENING. FORTUNATELY...THIS BAND WILL ONLY IMPACT PORTIONS OF
STEUBEN AND YATES COUNTIES WITH ACCUMULATIONS ACROSS THESE AREAS
LIKELY REMAINING BELOW ADVISORY THRESHOLDS. MAIN CONCERN THROUGH
THE REMAINDER OF THE OVERNIGHT CONTINUES TO BE DEVELOPING LAKE
SNOWS EAST OF LAKE ONTARIO AND POTENTIAL IMPACTS ACROSS PORTIONS
OF ONEIDA COUNTY. LATEST HIGH-RES MODEL SUITE CONTINUES TO SHOW
SOLID BAND ORGANIZATION AFTER THE 06Z TIME FRAME AS WESTERLY FLOW
BECOMES ALIGNED WITH THE LONG AXIS OF LAKE ONTARIO. QUICK LOOK AT
THE MOST RECENT 00Z BUF SOUNDING REVEALS MIXED LAYER HEIGHTS UP TO
ROUGHLY 14 KFT WITH MANUAL SKEW-T ADJUSTMENTS FOR CURRENT LAKE
TEMPS YIELDING CAPE VALUES IN EXCESS OF 500 J/KG. THIS COMBINED
850-MB TEMPS NEAR OF NEAR -20C WILL SET THE STAGE FOR WHAT SHOULD
BE A BONAFIDE SINGLE LAKE EFFECT BAND THROUGH THE EARLY MORNING
WITH THIS FEATURE THEN PERSISTING FOR MUCH OF THE DAY ON TUESDAY.
MAIN QUESTION CONTINUES TO BE JUST HOW FAR SOUTH THIS BAND WILL GO
AS CURRENT HIGH-RES MODELS SUGGEST BAND WILL OSCILLATE QUITE A BIT
THROUGH THE DAY WHICH MAY BE A RESULT OF EXTREME INSTABILITY IN
THE MIXED LAYER AND POTENTIAL CONVECTIVE OVERTURNING. THIS RAISES
OUR SUSPICIONS THAT SOUTHERN ONEIDA COUNTY MAY ALSO GET A FAIRLY
HEALTHY DOSE OF FRESH SNOW AS THE EVENT PROGRESSES AND FUTURE
FORECAST UPDATES MAY HAVE TO CONSIDER A SOUTHWARD EXTENSION TO THE
CURRENT LAKE EFFECT SNOW WARNING.
ELSEWHERE TONIGHT...EXPECT PASSING LIGHT SNOW SHOWERS FROM TIME TO
TIME WITH LITTLE TO NO ADDITIONAL ACCUMULATIONS ACROSS THE FINGER
LAKES AND POINTS SOUTH. TEMPS WILL CONTINUE TO FALL INTO THE
LOWER TO MIDDLE TEENS FOR OVERNIGHT LOWS.
450 PM UPDATE...
HAVE HOISTED A QUICK WINTER WX ADVISORY FROM THE CENTRAL SOUTHERN
TIER NORTHEAST THROUGH THE FINGER LAKES AND UPPER SUSQUEHANNA
VALLEY REGIONS AS A NOTABLE LOW-LEVEL CONVERGENT SIGNATURE AS
NOTED IN THE LATEST MSLP FIELD IS LEADING TO AN IMPRESSIVE LINEAR
SNOW BAND. HAVE RECEIVED MULTIPLE 3 TO 5 INCH REPORTS ACROSS THE
CENTRAL FINGER LAKES REGION AND BASED ON LATEST RR FORECASTS FROM
THE SPC MESO PAGE...WE EXPECT THIS LOW-LEVEL CONVERGENCE REGION
TO REMAIN IN PLACE FOR A FEW MORE HRS BEFORE FINALLY WINDING DOWN
AFTER 00Z. BASED ON THIS...HAVE INCREASED SNOWFALL TOTALS ACROSS
THE REGION WITH 4 TO 6 INCHES POSSIBLE FOR AREAS IN CLOSE PROXIMITY
TO THE LOW-LEVEL CONVERGENT MAXIMUM. NO OTHER CHANGES NEEDED AT
THIS TIME.
PREVIOUS NEAR TERM DISCUSSION...
FCST AREA WILL REMAIN UNDER NW FLOW ALOFT WITH A FEW EMBEDDED
S/WV`S TRAVERSING THE RGN. 1ST ONE IS CRNTLY AFFECTING THE FCST
AREA WITH AREAS OF LGT SNOW...AND 2ND ONE IS FCST TO MOVE INTO THE
RGN ON WED NGT. A MEANDERING FNTL BNDRY AND LES INFLUENCES WILL
CONTINUE TO MODULATE THE SHSN ACTIVITY ACRS THE FCST AREA INTO MID
WEEK.
LATER TNGT AS THE 1ST WAVE DEPARTS...LOW LVL FLOW WILL BCM WRLY AND
FOCUS LES EFFECTS INTO NRN ONEIDA COUNTY AS 850 TEMPS DROPS TO ARND
-20C. LOW LVL 270 FLOW BCMS ALIGNED BY 06Z. HIGH INVERSION LVL
(10K FT)...ALIGNED FLOW AND GOOD SNOW GROWTH PROFILE. CRNT FCST
HAS ACCUMS OF 6-10 INCHES PRIMARILY NEAR THE OSWEGO/LEWIS COUNTY
BORDER. BOTTOM LINE IS THAT SRN PERIPHERY OF THIS BAND IS XPCTD TO
BE OVER NRN ONEIDA WITH LOW END WARNING ACCUMS. THIS BAND IS FCST
TO DROP SWD LATE TUE AFTN INTO NRN ONON/MAD/SRN ONEIDA/NRN OTSEGO.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
LES BAND XPCTD TO MEANDER ACRS FAVORED 290-300 FLOW REGIONS INTO
WED MRNG...WHICH MAY BE ENHANCED BY LOW LVL CONVERGENCE ASSCD WITH
SAGGING ARCTIC BNDRY. THIS ACTIVITY SHUD WEAKEN BY WED AFTN.
PROFILES STILL LOOKING GOOD DURING THIS TIME FRAME...AS INVERSION
LVL REMAINS HIGH AT 9-10 K FT AND LOW LVL FLOW REMAINS ALIGNED
ARND 300 DEG...THEN THE INVERSION LOWERS AND FLOW WEAKENS BY WED
AFTN. INITIAL THOUGHTS ARE THAT WE`LL NEED LES ADVISORIES FOR THIS
TIME PERIOD. WE`LL DEFER ON THE POTNL HEADLINES ATTM...AND LET THE
EVNG/MID SHIFTS RE-ASSESS. HAVE MENTIONED POTNL IN THE UPDATED
HWO. OUTSIDE THE MAIN LES AREAS...SLGT CHC TO LOW CHC POPS...WITH
POTNL FOR LAKE ERIE ACTIVITY TO CUT ACRS PORTIONS OF THE SRN TIER
AND NE PA.
CONCERNING WIND CHILLS...GIVEN CRNT FCST TEMPS AND WINDS WE DO NOT
SHOW ANY VALUES BLO -15 UNTIL TMRW NGT ACRS ONEIDA COUNTY. PSBL
THAT A FEW OTHER LOCATIONS COULD APRCH VALUES. LATER SHIFTS CAN
RE-EVALUATE THIS.
ON WED XPCT LES ACTIVITY TO DIMINISH BUT APRCHNG S/WV COULD RESULT
IN DVLPMNT OF MORE --SHSN AS THE DAY PROGRESSES SO WE CONTINUE
WITH CHC POPS MOST LOCATIONS. BEST CHC FOR A DRY DAY WILL BE
THURSDAY AS SFC HIGH IS XPCTD TO CREST OVER THE RGN LATE IN THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED.
INITIALLY A SOUTHERN STREAM SYSTEM WILL TRACK THROUGH THE MID
ATLANTIC REGION ON FRIDAY. THE ECMWF/CANADIAN IS MUCH FASTER THAN
THE GFS, LEANED TOWARD THE ECMWF ENSEMBLE WHICH IS A GOOD
COMPROMISE. THURSDAY NIGHT BACKED OFF ON POPS TO JUST CHC THEN
CHC/LIKELY ON FRIDAY WITH LIKELY POPS ACROSS THE SOUTHERN TIER AND
NE PA. MODELS INDICATE ALL SNOW WITH NO HINT OF ANY WARM LAYER.
BEHIND THIS WAVE THE UPPER LEVEL TROF WILL AMPLIFY OVER THE
NORTHEAST MAKING FOR A COLD WEEKEND WITH SCATTERED SNOW SHOWERS IN
NORTH/NORTHWEST FLOW. BY SUNDAY/MONDAY, UPPER LEVEL HEIGHTS RISE
WITH THE AIRMASS EXPECTED TO MODIFY UNDER SOUTHWEST FLOW.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL DISTURBANCE AND ITS ASSOCIATED WEAK SFC FEATURE
WILL TRACK ACROSS CENTRAL PA LATE THIS AFTERNOON THROUGH THE EARLY
EVENING. THIS SYSTEM WILL PRODUCE WIDESPREAD MVFR CONDITIONS IN LIGHT
SNOW ACROSS ALL OF THE TERMINALS THIS AFTERNOON THROUGH THE EARLY
EVENING PERIOD. ACROSS THE SOUTHERN TERMINALS IFR CONDITIONS ARE
POSSIBLE BETWEEN 18Z-00Z, BUT MOST LIKELY AT KBGM/KAVP. BEHIND
THIS WAVE NORTHWEST FLOW WILL DEVELOP KEEPING PRIMARILY MVFR
CONDITIONS ACROSS THE REGION THROUGH 06Z WITH SCATTERED FLURRIES
AND SNOW SHOWERS. AFTER 06Z CONDITIONS WILL BE PRIMARILY VFR WITH
SOUTHWEST WINDS DEVELOPING. THE LAKE EFFECT SNOW IS EXPECTED TO
REMAIN NORTH OF THE KRME/KSYR TERMINALS THROUGH 18Z BUT AFTER 18Z
IT IS EXPECTED TO AFFECT THE AIRPORTS WITH IFR CONDITIONS LIKELY.
SOUTHWEST WINDS AROUND 5 KNOTS OT LIGHT AND VARIABLE BECOMING
NORTHWEST THIS EVENING AROUND 10 KNOTS SHIFTING TO THE SOUTHWEST
TOWARD DAYBREAK AND INCREASING TO 12-15 KNOTS WITH GUSTS AROUND 25
KNOTS.
.OUTLOOK...
TUE NIGHT THRU WED...MVFR/IFR IN SNOW SHOWERS FOR KRME/KSYR
OTHERWISE PRIMARILY VFR.
THURSDAY/THURSDAY NIGHT...PRIMARILY VFR.
FRI... IFR CONDITIONS POSSIBLE IN SNOW.
FRIDAY NIGHT/SATURDAY...MVFR SNOW SHOWERS RESTRICTIONS LIKELY FOR
CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WATCH FROM 10 AM EST TUESDAY THROUGH
WEDNESDAY MORNING FOR NYZ018-036.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST WEDNESDAY FOR NYZ009-
037.
&&
$$
SYNOPSIS...
NEAR TERM...CMG
SHORT TERM...
LONG TERM...RRM
AVIATION...MLJ/RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
830 PM EST MON JAN 21 2013
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL TAPER OFF THIS EVENING AS A WEAK AREA
OF LOW PRESSURE TRACKS OUT OF THE REGION. COLDER AIR WILL ARRIVE
ON GUSTY WEST TO NORTHWEST WINDS LATER TONIGHT...WHICH WILL ALLOW LAKE
EFFECT SNOWS TO DEVELOP. THIS ACTIVITY WILL DIMINISH ON THURSDAY
AS HIGH PRESSURE BRIEFLY MOVES INTO THE AREA. OUTSIDE OF THE LAKE
EFFECT SNOW...PARTLY TO MOSTLY CLOUDY SKIES AND SCATTERED SNOW
SHOWERS OR FLURRIES ARE EXPECTED.
&&
.NEAR TERM /THROUGH TUESDAY/...
820 PM UPDATE...
EARLIER SNOWS THAT WARRANTED THE ISSUANCE OF A QUICK WINTER WX
ADVISORY HAVE PUSHED EAST AND CONTINUE TO EXIT THE FORECAST AREA
STAGE RIGHT. UPSTREAM RADAR TRENDS FROM KBUF CONTINUE TO SHOW A
HEALTHY LAKE ERIE BAND WHICH HAS LED TO OVER A FOOT OF SNOW IN
LESS THAN 4 HOURS ACROSS PORTIONS OF CHAUTAUQUA COUNTY EARLIER
THIS EVENING. FORTUNATELY...THIS BAND WILL ONLY IMPACT PORTIONS OF
STEUBEN AND YATES COUNTIES WITH ACCUMULATIONS ACROSS THESE AREAS
LIKELY REMAINING BELOW ADVISORY THRESHOLDS. MAIN CONCERN THROUGH
THE REMAINDER OF THE OVERNIGHT CONTINUES TO BE DEVELOPING LAKE
SNOWS EAST OF LAKE ONTARIO AND POTENTIAL IMPACTS ACROSS PORTIONS
OF ONEIDA COUNTY. LATEST HIGH-RES MODEL SUITE CONTINUES TO SHOW
SOLID BAND ORGANIZATION AFTER THE 06Z TIME FRAME AS WESTERLY FLOW
BECOMES ALIGNED WITH THE LONG AXIS OF LAKE ONTARIO. QUICK LOOK AT
THE MOST RECENT 00Z BUF SOUNDING REVEALS MIXED LAYER HEIGHTS UP TO
ROUGHLY 14 KFT WITH MANUAL SKEW-T ADJUSTMENTS FOR CURRENT LAKE
TEMPS YIELDING CAPE VALUES IN EXCESS OF 500 J/KG. THIS COMBINED
850-MB TEMPS NEAR OF NEAR -20C WILL SET THE STAGE FOR WHAT SHOULD
BE A BONAFIDE SINGLE LAKE EFFECT BAND THROUGH THE EARLY MORNING
WITH THIS FEATURE THEN PERSISTING FOR MUCH OF THE DAY ON TUESDAY.
MAIN QUESTION CONTINUES TO BE JUST HOW FAR SOUTH THIS BAND WILL GO
AS CURRENT HIGH-RES MODELS SUGGEST BAND WILL OSCILLATE QUITE A BIT
THROUGH THE DAY WHICH MAY BE A RESULT OF EXTREME INSTABILITY IN
THE MIXED LAYER AND POTENTIAL CONVECTIVE OVERTURNING. THIS RAISES
OUR SUSPICIONS THAT SOUTHERN ONEIDA COUNTY MAY ALSO GET A FAIRLY
HEALTHY DOSE OF FRESH SNOW AS THE EVENT PROGRESSES AND FUTURE
FORECAST UPDATES MAY HAVE TO CONSIDER A SOUTHWARD EXTENSION TO THE
CURRENT LAKE EFFECT SNOW WARNING.
ELSEWHERE TONIGHT...EXPECT PASSING LIGHT SNOW SHOWERS FROM TIME TO
TIME WITH LITTLE TO NO ADDITIONAL ACCUMULATIONS ACROSS THE FINGER
LAKES AND POINTS SOUTH. TEMPS WILL CONTINUE TO FALL INTO THE
LOWER TO MIDDLE TEENS FOR OVERNIGHT LOWS.
450 PM UPDATE...
HAVE HOISTED A QUICK WINTER WX ADVISORY FROM THE CENTRAL SOUTHERN
TIER NORTHEAST THROUGH THE FINGER LAKES AND UPPER SUSQUEHANNA
VALLEY REGIONS AS A NOTABLE LOW-LEVEL CONVERGENT SIGNATURE AS
NOTED IN THE LATEST MSLP FIELD IS LEADING TO AN IMPRESSIVE LINEAR
SNOW BAND. HAVE RECEIVED MULTIPLE 3 TO 5 INCH REPORTS ACROSS THE
CENTRAL FINGER LAKES REGION AND BASED ON LATEST RR FORECASTS FROM
THE SPC MESO PAGE...WE EXPECT THIS LOW-LEVEL CONVERGENCE REGION
TO REMAIN IN PLACE FOR A FEW MORE HRS BEFORE FINALLY WINDING DOWN
AFTER 00Z. BASED ON THIS...HAVE INCREASED SNOWFALL TOTALS ACROSS
THE REGION WITH 4 TO 6 INCHES POSSIBLE FOR AREAS IN CLOSE PROXIMITY
TO THE LOW-LEVEL CONVERGENT MAXIMUM. NO OTHER CHANGES NEEDED AT
THIS TIME.
PREVIOUS NEAR TERM DISCUSSION...
FCST AREA WILL REMAIN UNDER NW FLOW ALOFT WITH A FEW EMBEDDED
S/WV`S TRAVERSING THE RGN. 1ST ONE IS CRNTLY AFFECTING THE FCST
AREA WITH AREAS OF LGT SNOW...AND 2ND ONE IS FCST TO MOVE INTO THE
RGN ON WED NGT. A MEANDERING FNTL BNDRY AND LES INFLUENCES WILL
CONTINUE TO MODULATE THE SHSN ACTIVITY ACRS THE FCST AREA INTO MID
WEEK.
LATER TNGT AS THE 1ST WAVE DEPARTS...LOW LVL FLOW WILL BCM WRLY AND
FOCUS LES EFFECTS INTO NRN ONEIDA COUNTY AS 850 TEMPS DROPS TO ARND
-20C. LOW LVL 270 FLOW BCMS ALIGNED BY 06Z. HIGH INVERSION LVL
(10K FT)...ALIGNED FLOW AND GOOD SNOW GROWTH PROFILE. CRNT FCST
HAS ACCUMS OF 6-10 INCHES PRIMARILY NEAR THE OSWEGO/LEWIS COUNTY
BORDER. BOTTOM LINE IS THAT SRN PERIPHERY OF THIS BAND IS XPCTD TO
BE OVER NRN ONEIDA WITH LOW END WARNING ACCUMS. THIS BAND IS FCST
TO DROP SWD LATE TUE AFTN INTO NRN ONON/MAD/SRN ONEIDA/NRN OTSEGO.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
LES BAND XPCTD TO MEANDER ACRS FAVORED 290-300 FLOW REGIONS INTO
WED MRNG...WHICH MAY BE ENHANCED BY LOW LVL CONVERGENCE ASSCD WITH
SAGGING ARCTIC BNDRY. THIS ACTIVITY SHUD WEAKEN BY WED AFTN.
PROFILES STILL LOOKING GOOD DURING THIS TIME FRAME...AS INVERSION
LVL REMAINS HIGH AT 9-10 K FT AND LOW LVL FLOW REMAINS ALIGNED
ARND 300 DEG...THEN THE INVERSION LOWERS AND FLOW WEAKENS BY WED
AFTN. INITIAL THOUGHTS ARE THAT WE`LL NEED LES ADVISORIES FOR THIS
TIME PERIOD. WE`LL DEFER ON THE POTNL HEADLINES ATTM...AND LET THE
EVNG/MID SHIFTS RE-ASSESS. HAVE MENTIONED POTNL IN THE UPDATED
HWO. OUSIDE THE MAIN LES AREAS...SLGT CHC TO LOW CHC POPS...WITH
POTNL FOR LAKE ERIE ACTIVITY TO CUT ACRS PORTIONS OF THE SRN TIER
AND NE PA.
CONCERNING WIND CHILLS...GIVEN CRNT FCST TEMPS AND WINDS WE DO NOT
SHOW ANY VALUES BLO -15 UNTIL TMRW NGT ACRS ONEIDA COUNTY. PSBL
THAT A FEW OTHER LOCATIONS COULD APRCH VALUES. LATER SHIFTS CAN
RE-EVALUATE THIS.
ON WED XPCT LES ACTIVITY TO DIMINISH BUT APRCHNG S/WV COULD RESULT
IN DVLPMNT OF MORE --SHSN AS THE DAY PROGRESSES SO WE CONTINUE
WITH CHC POPS MOST LOCATIONS. BEST CHC FOR A DRY DAY WILL BE
THURSDAY AS SFC HIGH IS XPCTD TO CREST OVER THE RGN LATE IN THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED.
INITIALLY A SOUTHERN STREAM SYSTEM WILL TRACK THROUGH THE MID
ATLANTIC REGION ON FRIDAY. THE ECMWF/CANADIAN IS MUCH FASTER THAN
THE GFS, LEANED TOWARD THE ECMWF ENSEMBLE WHICH IS A GOOD
COMPROMISE. THURSDAY NIGHT BACKED OFF ON POPS TO JUST CHC THEN
CHC/LIKELY ON FRIDAY WITH LIKELY POPS ACROSS THE SOUTHERN TIER AND
NE PA. MODELS INDICATE ALL SNOW WITH NO HINT OF ANY WARM LAYER.
BEHIND THIS WAVE THE UPPER LEVEL TROF WILL AMPLIFY OVER THE
NORTHEAST MAKING FOR A COLD WEEKEND WITH SCATTERED SNOW SHOWERS IN
NORTH/NORTHWEST FLOW. BY SUNDAY/MONDAY, UPPER LEVEL HEIGHTS RISE
WITH THE AIRMASS EXPECTED TO MODIFY UNDER SOUTHWEST FLOW.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL DISTURBANCE AND ITS ASSOCIATED WEAK SFC FEATURE
WILL TRACK ACROSS CENTRAL PA LATE THIS AFTERNOON THROUGH THE EARLY
EVENING. THIS SYSTEM WILL PRODUCE WIDESPREAD MVFR CONDITIONS IN LIGHT
SNOW ACROSS ALL OF THE TERMINALS THIS AFTERNOON THROUGH THE EARLY
EVENING PERIOD. ACROSS THE SOUTHERN TERMINALS IFR CONDITIONS ARE
POSSIBLE BETWEEN 18Z-00Z, BUT MOST LIKELY AT KBGM/KAVP. BEHIND
THIS WAVE NORTHWEST FLOW WILL DEVELOP KEEPING PRIMARILY MVFR
CONDITIONS ACROSS THE REGION THROUGH 06Z WITH SCATTERED FLURRIES
AND SNOW SHOWERS. AFTER 06Z CONDITIONS WILL BE PRIMARILY VFR WITH
SOUTHWEST WINDS DEVELOPING. THE LAKE EFFECT SNOW IS EXPECTED TO
REMAIN NORTH OF THE KRME/KSYR TERMINALS THROUGH 18Z BUT AFTER 18Z
IT IS EXPECTED TO AFFECT THE AIRPORTS WITH IFR CONDITIONS LIKELY.
SOUTHWEST WINDS AROUND 5 KNOTS OT LIGHT AND VARIABLE BECOMING
NORTHWEST THIS EVENING AROUND 10 KNOTS SHIFTING TO THE SOUTHWEST
TOWARD DAYBREAK AND INCREASING TO 12-15 KNOTS WITH GUSTS AROUND 25
KNOTS.
.OUTLOOK...
TUE NIGHT THRU WED...MVFR/IFR IN SNOW SHOWERS FOR KRME/KSYR
OTHERWISE PRIMARILY VFR.
THURSDAY/THURSDAY NIGHT...PRIMARILY VFR.
FRI... IFR CONDITIONS POSSIBLE IN SNOW.
FRIDAY NIGHT/SATURDAY...MVFR SNOW SHOWERS RESTRICTIONS LIKELY FOR
CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING FROM 1 AM TUESDAY TO 1 PM EST
WEDNESDAY FOR NYZ009.
&&
$$
SYNOPSIS...
NEAR TERM...CMG
SHORT TERM...
LONG TERM...RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
823 PM EST MON JAN 21 2013
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL TAPER OFF THIS EVENING AS A WEAK AREA
OF LOW PRESSURE TRACKS OUT OF THE REGION. COLDER AIR WILL ARRIVE
ON GUSTY WEST TO NORTHWEST WINDS LATER TONIGHT...WHICH WILL ALLOW LAKE
EFFECT SNOWS TO DEVELOP. THIS ACTIVITY WILL DIMINISH ON THURSDAY
AS HIGH PRESSURE BRIEFLY MOVES INTO THE AREA. OUTSIDE OF THE LAKE
EFFECT SNOW...PARTLY TO MOSTLY CLOUDY SKIES AND SCATTERED SNOW
SHOWERS OR FLURRIES ARE EXPECTED.
&&
.NEAR TERM /THROUGH TUESDAY/...
450 PM UPDATE...
HAVE HOISTED A QUICK WINTER WX ADVISORY FROM THE CENTRAL SOUTHERN
TIER NORTHEAST THROUGH THE FINGER LAKES AND UPPER SUSQUEHANNA
VALLEY REGIONS AS A NOTABLE LOW-LEVEL CONVERGENT SIGNATURE AS
NOTED IN THE LATEST MSLP FIELD IS LEADING TO AN IMPRESSIVE LINEAR
SNOW BAND. HAVE RECEIVED MULTIPLE 3 TO 5 INCH REPORTS ACROSS THE
CENTRAL FINGER LAKES REGION AND BASED ON LATEST RR FORECASTS FROM
THE SPC MESO PAGE...WE EXPECT THIS LOW-LEVEL CONVERGENCE REGION
TO REMAIN IN PLACE FOR A FEW MORE HRS BEFORE FINALLY WINDING DOWN
AFTER 00Z. BASED ON THIS...HAVE INCREASED SNOWFALL TOTALS ACROSS
THE REGION WITH 4 TO 6 INCHES POSSIBLE FOR AREAS IN CLOSE PROXIMITY
TO THE LOW-LEVEL CONVERGENT MAXIMUM. NO OTHER CHANGES NEEDED AT
THIS TIME.
PREVIOUS NEAR TERM DISCUSSION...
FCST AREA WILL REMAIN UNDER NW FLOW ALOFT WITH A FEW EMBEDDED
S/WV`S TRAVERSING THE RGN. 1ST ONE IS CRNTLY AFFECTING THE FCST
AREA WITH AREAS OF LGT SNOW...AND 2ND ONE IS FCST TO MOVE INTO THE
RGN ON WED NGT. A MEANDERING FNTL BNDRY AND LES INFLUENCES WILL
CONTINUE TO MODULATE THE SHSN ACTIVITY ACRS THE FCST AREA INTO MID
WEEK.
LATER TNGT AS THE 1ST WAVE DEPARTS...LOW LVL FLOW WILL BCM WRLY AND
FOCUS LES EFFECTS INTO NRN ONEIDA COUNTY AS 850 TEMPS DROPS TO ARND
-20C. LOW LVL 270 FLOW BCMS ALIGNED BY 06Z. HIGH INVERSION LVL
(10K FT)...ALIGNED FLOW AND GOOD SNOW GROWTH PROFILE. CRNT FCST
HAS ACCUMS OF 6-10 INCHES PRIMARILY NEAR THE OSWEGO/LEWIS COUNTY
BORDER. BOTTOM LINE IS THAT SRN PERIPHERY OF THIS BAND IS XPCTD TO
BE OVER NRN ONEIDA WITH LOW END WARNING ACCUMS. THIS BAND IS FCST
TO DROP SWD LATE TUE AFTN INTO NRN ONON/MAD/SRN ONEIDA/NRN OTSEGO.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
LES BAND XPCTD TO MEANDER ACRS FAVORED 290-300 FLOW REGIONS INTO
WED MRNG...WHICH MAY BE ENHANCED BY LOW LVL CONVERGENCE ASSCD WITH
SAGGING ARCTIC BNDRY. THIS ACTIVITY SHUD WEAKEN BY WED AFTN.
PROFILES STILL LOOKING GOOD DURING THIS TIME FRAME...AS INVERSION
LVL REMAINS HIGH AT 9-10 K FT AND LOW LVL FLOW REMAINS ALIGNED
ARND 300 DEG...THEN THE INVERSION LOWERS AND FLOW WEAKENS BY WED
AFTN. INITIAL THOUGHTS ARE THAT WE`LL NEED LES ADVISORIES FOR THIS
TIME PERIOD. WE`LL DEFER ON THE POTNL HEADLINES ATTM...AND LET THE
EVNG/MID SHIFTS RE-ASSESS. HAVE MENTIONED POTNL IN THE UPDATED
HWO. OUTSIDE THE MAIN LES AREAS...SLGT CHC TO LOW CHC POPS...WITH
POTNL FOR LAKE ERIE ACTIVITY TO CUT ACRS PORTIONS OF THE SRN TIER
AND NE PA.
CONCERNING WIND CHILLS...GIVEN CRNT FCST TEMPS AND WINDS WE DO NOT
SHOW ANY VALUES BLO -15 UNTIL TMRW NGT ACRS ONEIDA COUNTY. PSBL
THAT A FEW OTHER LOCATIONS COULD APRCH VALUES. LATER SHIFTS CAN
RE-EVALUATE THIS.
ON WED XPCT LES ACTIVITY TO DIMINISH BUT APRCHNG S/WV COULD RESULT
IN DVLPMNT OF MORE --SHSN AS THE DAY PROGRESSES SO WE CONTINUE
WITH CHC POPS MOST LOCATIONS. BEST CHC FOR A DRY DAY WILL BE
THURSDAY AS SFC HIGH IS XPCTD TO CREST OVER THE RGN LATE IN THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED.
INITIALLY A SOUTHERN STREAM SYSTEM WILL TRACK THROUGH THE MID
ATLANTIC REGION ON FRIDAY. THE ECMWF/CANADIAN IS MUCH FASTER THAN
THE GFS, LEANED TOWARD THE ECMWF ENSEMBLE WHICH IS A GOOD
COMPROMISE. THURSDAY NIGHT BACKED OFF ON POPS TO JUST CHC THEN
CHC/LIKELY ON FRIDAY WITH LIKELY POPS ACROSS THE SOUTHERN TIER AND
NE PA. MODELS INDICATE ALL SNOW WITH NO HINT OF ANY WARM LAYER.
BEHIND THIS WAVE THE UPPER LEVEL TROF WILL AMPLIFY OVER THE
NORTHEAST MAKING FOR A COLD WEEKEND WITH SCATTERED SNOW SHOWERS IN
NORTH/NORTHWEST FLOW. BY SUNDAY/MONDAY, UPPER LEVEL HEIGHTS RISE
WITH THE AIRMASS EXPECTED TO MODIFY UNDER SOUTHWEST FLOW.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
01Z TUE UPDATE... STEADIER SNOW IS IN THE PROCESS OF EXITING
NY`S SRN TIER AND NE PA ATTM. THUS...WE SHOULD BE MAINLY VFR FOR
THE REST OF THE NGT AT KITH/KBGM/KELM/KAVP. AT KRME/KSYR...A BRIEF
PD OF RESTRICTIVE SNOW IS STILL PSBL LTR THIS EVE...AS PIECES OF
MOISTURE BREAK AWAY FROM BOTH THE LK ERIE AND LK ONT BANDS
UPSTREAM...AND A WEAK UPR-LVL DISTURBANCE ALSO PASSES THROUGH.
EARLY TUE AM...AN INTENSIFYING LK ONT BAND IS STILL EXPECTED TO
DROP SWD...WITH IFR/LIFR CONDS FORESEEN AT KRME BY ARND 12Z. AT
KSYR...IT WILL PERHAPS TAKE UNTIL MIDDAY FOR THE LAKE SNOWS TO
KICK IN...SO IFR/LIFR IS DELAYED TIL 17Z. ONCE SNOW DVLPS AT EACH
OF THESE SITES...IFR SHOULD BE FAIRLY PERSISTENT THE BALANCE OF
THE DAY.
ELSEWHERE ON TUE...MOSTLY VFR SHOULD BE THE RULE...WITH JUST TRANSIENT
SNW SHWRS/FLRYS PASSING THROUGH FROM TIME TO TIME.
W TO SW WINDS 5-10 KT OVERNIGHT...WILL BECOME W TO NW ON TUE...AND
INCREASE TO ARND 15 KT...WITH OCNL 25-30 KT GUSTS LIKELY.
.OUTLOOK...
TUE NIGHT THRU WED...MVFR/IFR IN SNOW SHOWERS FOR KRME/KSYR...
OTHERWISE PRIMARILY VFR.
THURSDAY/THURSDAY NIGHT...PRIMARILY VFR.
FRI... IFR CONDITIONS POSSIBLE IN SNOW.
FRIDAY NIGHT/SATURDAY...MVFR SNOW SHOWERS RESTRICTIONS LIKELY FOR
CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING FROM 1 AM TUESDAY TO 1 PM EST
WEDNESDAY FOR NYZ009.
&&
$$
SYNOPSIS...
NEAR TERM...CMG
SHORT TERM...
LONG TERM...RRM
AVIATION...MLJ/RRM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
627 PM EST MON JAN 21 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL MOVE THROUGH THE REGION TONIGHT
FOLLOWED BY COLD HIGH PRESSURE BUILDING IN FROM THE NORTHWEST
TUESDAY THROUGH THURSDAY. THE HIGH WILL SHIFT OFFSHORE FRIDAY.
ANOTHER STRONG COLD FRONT WILL CROSS THE AREA FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 620 PM MONDAY...LEADING EDGE OF THE COLD AIR NOW LYING ON A
ROUGHLY DANVILLE TO HICKORY TO ASHEVILLE LINE AND PROGRESSING
EAST. GOOD AGREEMENT AMONGST THE LATEST RAP AND 12 KM NAM THAT THE
FRONT CROSSES OUR CWA BETWEEN ABOUT 05Z AND 08Z WITH INCREASING
GUSTY NORTHWEST WINDS DEVELOPING AND TEMPERATURES PLUNGING INTO
THE UPPER 20S AND LOWER 30S BY MORNING. NO MAJOR CHANGES TO THE
FORECAST EXCEPT TO RAISE TEMPERATURES/DEWPOINTS SLIGHTLY FOR THE
NEXT COUPLE OF HOURS IN THE SOUTHWESTERLY SURFACE FLOW AHEAD OF
THE FRONT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS OF 245 PM MON...MAIN STORY FOR TUESDAY WITH BE THE COLD TEMPS.
COLDEST AIR OF THE SEASON EXPECTED ACROSS NC TUE IN WAKE OF ARCTIC
COLD FRONT. LOW LEVEL THICKNESS VALUES AND 850MB TEMPS -6 TO -13C
SUPPORT HIGH TEMPS GENERALLY 35-40 DEG. HOWEVER WITH DECENT NW
WINDS...EXPECT IT TO FEEL MORE LIKE 20S/L30S. HIGHS ABOUT 15-20DEG
BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
AMPLIFYING UPPER TROUGH WILL LINGER ACROSS THE EASTERN US THROUGH
MID WEEK WHICH WILL MAINTAIN WELL BELOW NORMAL TEMPERATURES THRU
THURSDAY. VERY COLD OVERNIGHT LOWS IN THE UPPER TEENS AND LOWER
20S TUESDAY NIGHT AND HIGHS WILL BE NEAR 40F DEG ACRS SOUTHERN
PORTIONS OF THE AREA WITH MID 30S NORTH ZONES WEDNESDAY. A
SECONDARY DRY COLD FRONT WILL PASS THRU WEDNESDAY NIGHT BUT BNDRY
LAYER MIXING WILL KEEP OVERNIGHT LOWS IN THE 20S INLAND AND 30S
OBX. GOOD DOWNSLOPING AS UPPER FLOW BECOMES MORE WNW/ZONAL WILL
ALLOW A SLIGHT WARMING TREND WITH HIGHS ON THURSDAY IN THE 40S.
CLOUDS INCREASING AHEAD OF NEXT UPPER TROF ALONG WITH A DEVELOPING
LOW LEVEL RETURN FLOW WILL HELP HOLD TEMPS UP THU NIGHT IN THE
UPPER 20S TO LOWER 30S. ANOTHER STRONG COLD FRONT WILL APPROACH
THE AREA ON FRIDAY WITH A MODEL CONCENSUS FAVORING A LATE DAY OR
EVENING FROPA. AHEAD OF THE FRONT...HIGHS FRIDAY WILL BE REACH
INTO THE UPPER 50S (SLIGHTLY ABOVE NORMAL) BEFORE PLUNGING BACK
TO WELL BELOW NORMAL/BITTERLY COLD LEVELS AGAIN NEXT WEEKEND.
WILL CONTINUE TO INDICATE BEST PRECIP CHANCES WILL BE OCCURRING
ALONG AND BEHIND THE FRONT LATE FRIDAY INTO FRIDAY NIGHT BUT CAP
POPS AT HIGH CHANCE GIVEN CONTINUED MODEL TIMING DIFFERENCES. MAY
ALSO SEE A PERIOD OF FROZEN PRECIP BEFORE ENDING FRIDAY NIGHT OR
EARLY SATURDAY BUT WILL WAIT UNTIL BETTER MODEL CONCENSUS BEFORE
INTRODUCING INTO THE FCST.
A RETURN TO ZONAL FLOW AND RISING LOW LEVEL THICKNESS SUGGEST A
RETURN TO NEAR NORMAL TEMPS EARLY NEXT WEEK.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...
AS OF 620 PM MON...EXPECTING VFR CONDITIONS TO PREVAIL OVERNIGHT
AND TUESDAY. STRONG DRY COLD FRONT WILL CROSS THE REGION OVERNIGHT
WITH GUSTY NW WINDS OF UP TO 20 TO 25 MPH LIKELY BEGINNING EARLY
TUESDAY MORNING AND CONTINUING THROUGH LATE AFTERNOON.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
PREDOMINANT VFR CONDITIONS EXPECTED WITH DRY CONDITIONS AND
LIMITED LOW CLOUD COVER THROUGH THURSDAY. A MODERATE SLY FLOW
RETURNS LATE IN WEEK WITH INCREASING MOISTURE IN THE LOW LEVELS
AND THE POSSIBILITY OF SUB-VFR CONDS FRIDAY AND POSSIBLY LINGERING
INTO EARLY SATURDAY.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY/...
AS OF 625 PM MON...NO MAJOR CHANGES TO MARINE FORECAST AS STRONG
DRY COLD FRONT NOW MOVING ACROSS WESTERN NORTH CAROLINA SHOULD
MAKE IT TO THE COAST AROUND 09Z TO 11Z EARLY TUESDAY MORNING.
WINDS CURRENTLY S/SSW AT 10 KNOTS OR LESS WITH SEAS 2 TO 4 FEET.
THE WINDS VEER TO NW AND BECOME GUSTY BEHIND THE FRONT WITH STRONG
COLD AIR ADVECTION BY EARLY TUESDAY MORNING THROUGH THE DAY TUESDAY
BEFORE SUBSIDING BY TUESDAY EVENING.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
INITIAL COLD AIR SURGE BEHIND FRONT WILL SLOWLY DIMINISH TUESDAY
NIGHT AS HIGH PRESSURE BUILDS OVER THE WATERS WITH THE SMALL
CRAFT ADVISORY CONDITIONS FORECAST TO END BY EARLY WED. A
SECONDARY COLD FRONT WILL DROP THRU THE WATERS WED NIGHT WHICH MAY
BRIEFLY KICK UP WINDS AND SEAS TO NEAR SCA LEVELS ON THU. WINDS
BECOME SW THU NIGHT AND PRES GRAD TIGHTENS AHEAD OF THE NEXT
CDFNT. SCA CONDS ARE EXPECTED TO DEVELOP FRIDAY AND LINGER INTO
EARLY NEXT WEEKEND.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EST
TUESDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 1 PM EST
TUESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CQD/DAG
NEAR TERM...CTC
SHORT TERM...CQD
LONG TERM...BTC
AVIATION...CTC/BTC/CQD
MARINE...CTC/BTC/CQD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1022 PM EST MON JAN 21 2013
.SYNOPSIS...
ARCTIC AIR WILL POUR INTO CENTRAL PENNSYLVANIA TONIGHT BEHIND A
CLIPPER SYSTEM...PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS AND
A FEW SQUALLS. LAKE EFFECT SNOW WILL PRODUCE SEVERAL INCHES OF
ACCUMULATION OVER THE FAR NORTHWEST...WHILE WIND CHILLS WILL DROP
BELOW 15 BELOW ZERO OVER THE LAUREL HIGHLANDS LATER TONIGHT.
THE SURGE OF ARCTIC AIR WILL LAST THROUGH MID WEEK. LAKE EFFECT
SNOW SHOWERS WILL CONTINUE INTO TUESDAY EVENING BEFORE DECREASING.
A LOW PRESSURE SYSTEM WILL TRACK FROM THE SOUTHERN PLAINS TO THE
MID ATLANTIC COAST LATE IN THE WEEK BRINGING A CHANCE OF SNOW
TO MOST OF THE AREA.
&&
.NEAR TERM /UNTIL 8 AM TUESDAY MORNING/...
BIG OL LES BAND PARALLEL TO THE LAKE SHORE LINE IS BREAKING UP AS
THE FLOW IN THE LOWEST 5-10KFT BECOMES MORE NWRLY. THE PROGS
FROM THE NAM/RUC AND HRRR STILL POINT TO THIS BAND/AREA CONTINUING
TO SLIDE ESE AND PIVOT TO BE MORE WEST-EAST BEFORE FIZZLING AS IT
NEARS I-80. THE TRANSITORY NATURE SHOULD KEEP ACCUMS IN THE RANGE
WE HAVE GOING. FETCH IS ALL VERY FAVORABLE FOR SNOW TO PILE UP
OVER WARREN COUNTY AND ALSO ACCUMULATE ACROSS THE REST OF THE
NW/NRN MTS. CONSIDERED A BUMP TO LES WARNING FOR WARREN COUNTY
/AND PERHAPS ADVY IN MCKEAN CO/ WITH SOME HIGHER THAN 8 INCH
ACCUMS POSS IN THE NW SNOW BELT AND N OF ROUTE 6. BUT DECIDED TO
HOLD THE COURSE SINCE THERE HAS BEEN LITTLE SNOW IN WARREN COUNTY
THROUGH THE DAY. NEW NAM AND OTHER MESO MDLS ALSO HOLD NO BIG
REVELATIONS.
THE UPSLOPE FLOW IS ABOUT THE ONLY THING GOING FOR SNOW ACCUMS IN
THE LAURELS. LOTS OF LARGE BREAKS IN THE CLOUDS NOW...BUT IT TOO
SHOULD TREND TOWARD A CLIMO LOOK AS THE FLOW BECOMES WNW.
THE ARCTIC AIR HAS ALREADY BROUGHT TEMPS DOWN TO 10F IN THE WRN
MTS...AND WIND CHILLS ARE BELOW ZERO THERE AS WELL. WINDS JUST
PICKED UP IN THE VALLEYS OF THE EAST...AND WILL STAY UP ALL
NIGHT ACROSS THE AREA - WITH THE HIGHEST SPEEDS IN THE MTS.
THUS...THE WIND CHILL ADVY IS SOLID...AND WILL REMAIN. SPOTTY -15F
WIND CHILLS MAY BE HAD IN THE NRN MTS...BUT CLOUDS AND SLIGHTLY
LOWER WIND SPEEDS THERE SHOULD KEEP COUNTY-WIDE AREAS OF -15 FROM
OCCURRING. THIS IS ALREADY THE COLDEST NIGHT OF THE SEASON FOR
MOST OF PENNSYLVANIA.
&&
.SHORT TERM /8 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE UPPER TROF SWINGS ACROSS PA TONIGHT AND EARLY TUESDAY. A WELL
MIXED BLYR SHOULD ALLOW 25-30KT GUSTS TO MIX TO THE SFC
TUESDAY...PERSISTING THROUGHOUT THE DAY WITH WIND CHILLS REMAINING
BELOW ZERO FOR MUCH OF THE REGION. WIND CHILL ADVISORY WILL REMAIN
IN EFFECT OVER THE LAURELS THROUGHOUT THE DAY. ENS MEAN 850MB
TEMPS ARND -21C SHOULD TRANSLATE TO HIGHS ONLY NEAR 10F ACROSS THE
ALLEGHENY MTNS AND AROUND 20F ACROSS THE SUSQ VALLEY.
REGARDING LAKE EFFECT SNOW ADVISORY...BOUNDARY LAYER FLOW OF ARND
280 DEGREES WOULD PRECLUDE ANY HURON CONNECTION OR LONG FETCH WITH
THE HEAVIEST BANDS AND ACCUMS STAYING JUST NORTH OF MY AREA.
STILL...THE NEXT 24 HRS COULD HOLD 8 INCHES ACROSS NORTHWESTERN
WARREN COUNTY. A SLIGHT SOUTHWARD SHIFT IN BANDS COULD ALWAYS
OCCUR...AND WILL BE MONITORED. 20/1 RATIOS PRODUCE 6-8 INCHES OVER
THE SNOWBELT OF NW WARREN COUNTY BTWN THIS AFTN AND TUE EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
SOME SNOW SHOWERS WILL BE ACROSS NORTHERN AND WESTERN AREAS
TUE NIGHT AND WED...GIVEN NW FLOW OF COLD AIR.
MODELS HINT THAT ACTIVITY COULD BE A LITTLE MORE ACTIVE ON
WED...AS JET MAX MOVES ACROSS THE AREA.
DID NOT RUSH TO TAPER ACTIVITY WED NIGHT...GIVEN HOW COLD
THE AIRMASS IS.
THU WILL BE THE BEST DAY.
LEFT AMTS CLOSE TO WHAT WAS IN GRIDS FOR NEXT MODERATE
SNOW EVENT. YESTERDAY...MODELS WERE A LITTLE FASTER WITH
THE SYSTEM...TODAY THEY ARE SLOWER...SO MADE SOME TIMING
ADJUSTMENTS.
DID PUT SOME SLEET BACK IN...BUT JUST THE FAR SOUTH...GIVEN
POTENTIAL FOR SOME MID LVL WARMING. SYSTEM DOES NOT HAVE A
LOT OF GULF MOISTURE TO WORK WITH...BUT STRONG WARM ADVECTION
MAY AID IN BRIEF HEAVIER BURST OF SNOW.
MORE COLD AND SNOW SHOWERS FOR THE FIRST PART OF THE WEEKEND.
TEMPS MODERATE SOME FOR LATER SUNDAY INTO MONDAY.
SPEAKING OF TEMPS...COMBINATION OF WIND AND COLD SUPPORT
WIND CHILLS IN THE ADVISORY RANGE.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
BANDS OF SNOW SHOWERS AND ACCOMPANYING GUSTY WINDS CONTINUE CAUSE MVFR/OCNL
IFR CIGS AND VSBYS ACROSS EASTERN AREAS. BANDS OF HEAVIER SNOW
SHOWERS AND A FEW SQUALLS WILL ACCOMPANY LOW PRESSURE AND ITS
ASSOCIATED COLD FRONT THROUGH THIS EVENING. THOUGH MUCH COLDER AIR
WILL MOVE IN /-20C AT 850MB/...MOISTURE AGAIN LIMITED WHICH WILL
KEEP CIG/VSBY REDUCTIONS AND SNOW IMPACTS CONFINED MAINLY TO
HIGHER TERRAIN IN THE WEST. COLD FLOW ACROSS MUCH WARMER LAKES
WILL BRING LOWER CLOUDS INTO KBFD-KJST STARTING LATE TUESDAY MORNING
AND ENHANCE SNOW POTENTIAL IN THOSE SAME AREAS. BIGGEST SNOWFALL
WILL BE CONFINED CLOSER TO LAKE ERIE...BUT LIGHTER INTERMITTANT
BANDED SNOWS WILL IMPACT KBFD-KJST FOR NEXT COUPLE OF DAYS AS
PERSISTENT NW FLOW ESTABLISHES ITSELF. OCNL ENCROACHMENT OF MVFR
POSS INTO CENTRAL MTNS...WHILE DOWNSLOPE FLOW KEEPS WEATHER VFR IN
THE EAST.
WINDS WILL PICK BACK UP TODAY A BIT...ESPECIALLY OVER WESTERN
HIGHER TERRAIN WHERE GUSTS TO 20-30 MPH WILL AGAIN BECOME COMMON.
OUTLOOK...
TUE-THU AM...SHSN WITH MVFR/OCNL IFR W MTNS...SCT/LIKELY SHSN IN
MVFR CENTRAL MTNS...SCT SHSN AND PRIMARILY VFR SE.
THU PM-FRI...MVFR/IFR POSSIBLE LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR PAZ004.
WIND CHILL ADVISORY UNTIL 1 PM EST WEDNESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
753 PM EST MON JAN 21 2013
.SYNOPSIS...
ARCTIC AIR WILL POUR INTO CENTRAL PENNSYLVANIA TONIGHT BEHIND A
CLIPPER SYSTEM...PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS AND
A FEW SQUALLS. LAKE EFFECT SNOW WILL PRODUCE SEVERAL INCHES OF
ACCUMULATION OVER THE FAR NORTHWEST...WHILE WIND CHILLS WILL DROP
BELOW 15 BELOW ZERO OVER THE LAUREL HIGHLANDS LATER TONIGHT.
THE SURGE OF ARCTIC AIR WILL LAST THROUGH MID WEEK. LAKE EFFECT
SNOW SHOWERS WILL CONTINUE INTO TUESDAY EVENING BEFORE DECREASING.
A LOW PRESSURE SYSTEM WILL TRACK FROM THE SOUTHERN PLAINS TO THE
MID ATLANTIC COAST LATE IN THE WEEK BRINGING A CHANCE OF SNOW
TO MOST OF THE AREA.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
WEAK CLIPPER WITH LIGHT SNOW EXITING THE EASTERN PARTS OF THE
AREA AT 7 PM. LITTLE TO NO ADDITIONAL ACCUMS EXPECTED FROM THAT
AREA OF SNOW...BUT WILL HOLD ONTO HIGH POP WORDING FOR NOW SINCE
IT WILL BE FALLING FROM THE SKY FOR A LITTLE BIT LONGER. TURNING
TO THE REAL CONCERN...A MASSIVE LES BAND PARALLEL TO THE LAKE
SHORE LINE IS STARTING TO BE NUDGED INLAND BY THE MORE-NWRLY FLOW
MOVING ACROSS THE LAKE. THE PROGS FROM THE NAM/RUC AND HRRR ALL
POINT TO THIS BAND CONTINUING TO SLIDE ESE AND PIVOT TO BE MORE
WEST-EAST BEFORE FIZZLING AS IT NEARS I-80. THE TRANSITORY NATURE
SHOULD KEEP ACCUMS IN THE RANGE WE HAVE GOING. THEN THE BETTER
CROSS-LAKE FLOW BEGINS AFTER THE PASSAGE OF THE BIG BAND. FETCH IS
ALL VERY FAVORABLE FOR SNOW TO PILE UP OVER WARREN COUNTY AND ALSO
ACCUMULATE ACROSS THE REST OF THE NW/NRN MTS. CONSIDERING A BUMP
TO LES WARNING FOR WARREN COUNTY /AND PERHAPS ADVY IN MCKEAN CO/
WITH SOME HIGHER THAN 8 INCH ACCUMS POSS IN THE NW SNOW BELT AND
N OF ROUTE 6. WILL HOLD THAT THOUGHT UNTIL LATER TONIGHT WHEN FULL
SUITE OF NEW MDL DATA ARRIVES.
THE UPSLOPE FLOW IS ABOUT THE ONLY THING GOING FOR SNOW ACCUMS IN
THE LAURELS. EXPECT MUCH LOWER ACCUMS THERE TONIGHT...AND SOME
CLEARING MAY ALSO OCCUR TOWARD SUNRISE.
THE ARCTIC AIR WILL DROP TEMPS INTO THE SINGLE DIGITS IN THE WEST
TONIGHT...AND WINDS STAY UP ALL NIGHT. THUS...THE WIND CHILL ADVY
IS SOLID...AND WILL REMAIN. BOTTOM LINE...IT WILL BE COLDER THAN
WE HAVE SEEN ALL WINTER THUS FAR.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE UPPER TROF SWINGS ACROSS PA TONIGHT AND EARLY TUESDAY. A WELL
MIXED BLYR SHOULD ALLOW 25-30KT GUSTS TO MIX TO THE SFC
TUESDAY...PERSISTING THROUGHOUT THE DAY WITH WIND CHILLS REMAINING
BELOW ZERO FOR MUCH OF THE REGION. WIND CHILL ADVISORY WILL REMAIN
IN EFFECT OVER THE LAURELS THROUGHOUT THE DAY. ENS MEAN 850MB
TEMPS ARND -21C SHOULD TRANSLATE TO HIGHS ONLY NEAR 10F ACROSS THE
ALLEGHENY MTNS AND AROUND 20F ACROSS THE SUSQ VALLEY.
REGARDING LAKE EFFECT SNOW ADVISORY...BOUNDARY LAYER FLOW OF ARND
280 DEGREES WOULD PRECLUDE ANY HURON CONNECTION OR LONG FETCH WITH
THE HEAVIEST BANDS AND ACCUMS STAYING JUST NORTH OF MY AREA.
STILL...THE NEXT 24 HRS COULD HOLD 8 INCHES ACROSS NORTHWESTERN
WARREN COUNTY. A SLIGHT SOUTHWARD SHIFT IN BANDS COULD ALWAYS
OCCUR...AND WILL BE MONITORED. 20/1 RATIOS PRODUCE 6-8 INCHES OVER
THE SNOWBELT OF NW WARREN COUNTY BTWN THIS AFTN AND TUE EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
SOME SNOW SHOWERS WILL BE ACROSS NORTHERN AND WESTERN AREAS
TUE NIGHT AND WED...GIVEN NW FLOW OF COLD AIR.
MODELS HINT THAT ACTIVITY COULD BE A LITTLE MORE ACTIVE ON
WED...AS JET MAX MOVES ACROSS THE AREA.
DID NOT RUSH TO TAPER ACTIVITY WED NIGHT...GIVEN HOW COLD
THE AIRMASS IS.
THU WILL BE THE BEST DAY.
LEFT AMTS CLOSE TO WHAT WAS IN GRIDS FOR NEXT MODERATE
SNOW EVENT. YESTERDAY...MODELS WERE A LITTLE FASTER WITH
THE SYSTEM...TODAY THEY ARE SLOWER...SO MADE SOME TIMING
ADJUSTMENTS.
DID PUT SOME SLEET BACK IN...BUT JUST THE FAR SOUTH...GIVEN
POTENTIAL FOR SOME MID LVL WARMING. SYSTEM DOES NOT HAVE A
LOT OF GULF MOISTURE TO WORK WITH...BUT STRONG WARM ADVECTION
MAY AID IN BRIEF HEAVIER BURST OF SNOW.
MORE COLD AND SNOW SHOWERS FOR THE FIRST PART OF THE WEEKEND.
TEMPS MODERATE SOME FOR LATER SUNDAY INTO MONDAY.
SPEAKING OF TEMPS...COMBINATION OF WIND AND COLD SUPPORT
WIND CHILLS IN THE ADVISORY RANGE.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
BANDS OF SNOW SHOWERS AND ACCOMPANYING GUSTY WINDS CONTINUE CAUSE MVFR/OCNL
IFR CIGS AND VSBYS ACROSS EASTERN AREAS. BANDS OF HEAVIER SNOW
SHOWERS AND A FEW SQUALLS WILL ACCOMPANY LOW PRESSURE AND ITS
ASSOCIATED COLD FRONT THROUGH THIS EVENING. THOUGH MUCH COLDER AIR
WILL MOVE IN /-20C AT 850MB/...MOISTURE AGAIN LIMITED WHICH WILL
KEEP CIG/VSBY REDUCTIONS AND SNOW IMPACTS CONFINED MAINLY TO
HIGHER TERRAIN IN THE WEST. COLD FLOW ACROSS MUCH WARMER LAKES
WILL BRING LOWER CLOUDS INTO KBFD-KJST STARTING LATE TUESDAY MORNING
AND ENHANCE SNOW POTENTIAL IN THOSE SAME AREAS. BIGGEST SNOWFALL
WILL BE CONFINED CLOSER TO LAKE ERIE...BUT LIGHTER INTERMITTANT
BANDED SNOWS WILL IMPACT KBFD-KJST FOR NEXT COUPLE OF DAYS AS
PERSISTENT NW FLOW ESTABLISHES ITSELF. OCNL ENCROACHMENT OF MVFR
POSS INTO CENTRAL MTNS...WHILE DOWNSLOPE FLOW KEEPS WEATHER VFR IN
THE EAST.
WINDS WILL PICK BACK UP TODAY A BIT...ESPECIALLY OVER WESTERN
HIGHER TERRAIN WHERE GUSTS TO 20-30 MPH WILL AGAIN BECOME COMMON.
OUTLOOK...
TUE-THU AM...SHSN WITH MVFR/OCNL IFR W MTNS...SCT/LIKELY SHSN IN
MVFR CENTRAL MTNS...SCT SHSN AND PRIMARILY VFR SE.
THU PM-FRI...MVFR/IFR POSSIBLE LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR PAZ004.
WIND CHILL ADVISORY UNTIL 1 PM EST WEDNESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
705 PM EST MON JAN 21 2013
.SYNOPSIS...
ARCTIC AIR WILL POUR INTO CENTRAL PENNSYLVANIA TONIGHT BEHIND A
CLIPPER SYSTEM...PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS AND
A FEW SQUALLS. LAKE EFFECT SNOW WILL PRODUCE SEVERAL INCHES OF
ACCUMULATION OVER THE FAR NORTHWEST...WHILE WIND CHILLS WILL DROP
BELOW 15 BELOW ZERO OVER THE LAUREL HIGHLANDS LATER TONIGHT.
THE SURGE OF ARCTIC AIR WILL LAST THROUGH MID WEEK. LAKE EFFECT
SNOW SHOWERS WILL CONTINUE INTO TUESDAY EVENING BEFORE DECREASING.
A LOW PRESSURE SYSTEM WILL TRACK FROM THE SOUTHERN PLAINS TO THE
MID ATLANTIC COAST LATE IN THE WEEK BRINGING A CHANCE OF SNOW
TO MOST OF THE AREA.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
WEAK CLIPPER WITH LIGHT SNOW EXITING THE EASTERN PARTS OF THE
AREA AT 7 PM. LITTLE TO NO ADDITIONAL ACCUMS EXPECTED FROM THAT
AREA OF SNOW...BUT WILL HOLD ONTO HIGH POP WORDING FOR NOW SINCE
IT WILL BE FALLING FROM THE SKY FOR A LITTLE BIT LONGER. TURNING
TO THE REAL CONCERN...A MASSIVE LES BAND PARALLEL TO THE LAKE
SHORE LINE IS STARTING TO BE NUDGED INLAND BY THE MORE-NWRLY FLOW
MOVING ACROSS THE LAKE. THE PROGS FROM THE NAM/RUC AND HRRR ALL
POINT TO THIS BAND CONTINUING TO SLIDE ESE AND PIVOT TO BE MORE
WEST-EAST BEFORE FIZZLING AS IT NEARS I-80. THE TRANSITORY NATURE
SHOULD KEEP ACCUMS IN THE RANGE WE HAVE GOING. THEN THE BETTER
CROSS-LAKE FLOW BEGINS AFTER THE PASSAGE OF THE BIG BAND. FETCH IS
ALL VERY FAVORABLE FOR SNOW TO PILE UP OVER WARREN COUNTY AND ALSO
ACCUMULATE ACROSS THE REST OF THE NW/NRN MTS. CONSIDERING A BUMP
TO LES WARNING FOR WARREN COUNTY /AND PERHAPS ADVY IN MCKEAN CO/
WITH SOME HIGHER THAN 8 INCH ACCUMS POSS IN THE NW SNOW BELT AND
N OF ROUTE 6. WILL HOLD THAT THOUGHT UNTIL LATER TONIGHT WHEN FULL
SUITE OF NEW MDL DATA ARRIVES.
THE UPSLOPE FLOW IS ABOUT THE ONLY THING GOING FOR SNOW ACCUMS IN
THE LAURELS. EXPECT MUCH LOWER ACCUMS THERE TONIGHT...AND SOME
CLEARING MAY ALSO OCCUR TOWARD SUNRISE.
THE ARCTIC AIR WILL DROP TEMPS INTO THE SINGLE DIGITS IN THE WEST
TONIGHT...AND WINDS STAY UP ALL NIGHT. THUS...THE WIND CHILL ADVY
IS SOLID...AND WILL REMAIN. BOTTOM LINE...IT WILL BE COLDER THAN
WE HAVE SEEN ALL WINTER THUS FAR.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE UPPER TROF SWINGS ACROSS PA TONIGHT AND EARLY TUESDAY. A WELL
MIXED BLYR SHOULD ALLOW 25-30KT GUSTS TO MIX TO THE SFC
TUESDAY...PERSISTING THROUGHOUT THE DAY WITH WIND CHILLS REMAINING
BELOW ZERO FOR MUCH OF THE REGION. WIND CHILL ADVISORY WILL REMAIN
IN EFFECT OVER THE LAURELS THROUGHOUT THE DAY. ENS MEAN 850MB
TEMPS ARND -21C SHOULD TRANSLATE TO HIGHS ONLY NEAR 10F ACROSS THE
ALLEGHENY MTNS AND AROUND 20F ACROSS THE SUSQ VALLEY.
REGARDING LAKE EFFECT SNOW ADVISORY...BOUNDARY LAYER FLOW OF ARND
280 DEGREES WOULD PRECLUDE ANY HURON CONNECTION OR LONG FETCH WITH
THE HEAVIEST BANDS AND ACCUMS STAYING JUST NORTH OF MY AREA.
STILL...THE NEXT 24 HRS COULD HOLD 8 INCHES ACROSS NORTHWESTERN
WARREN COUNTY. A SLIGHT SOUTHWARD SHIFT IN BANDS COULD ALWAYS
OCCUR...AND WILL BE MONITORED. 20/1 RATIOS PRODUCE 6-8 INCHES OVER
THE SNOWBELT OF NW WARREN COUNTY BTWN THIS AFTN AND TUE EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
SOME SNOW SHOWERS WILL BE ACROSS NORTHERN AND WESTERN AREAS
TUE NIGHT AND WED...GIVEN NW FLOW OF COLD AIR.
MODELS HINT THAT ACTIVITY COULD BE A LITTLE MORE ACTIVE ON
WED...AS JET MAX MOVES ACROSS THE AREA.
DID NOT RUSH TO TAPER ACTIVITY WED NIGHT...GIVEN HOW COLD
THE AIRMASS IS.
THU WILL BE THE BEST DAY.
LEFT AMTS CLOSE TO WHAT WAS IN GRIDS FOR NEXT MODERATE
SNOW EVENT. YESTERDAY...MODELS WERE A LITTLE FASTER WITH
THE SYSTEM...TODAY THEY ARE SLOWER...SO MADE SOME TIMING
ADJUSTMENTS.
DID PUT SOME SLEET BACK IN...BUT JUST THE FAR SOUTH...GIVEN
POTENTIAL FOR SOME MID LVL WARMING. SYSTEM DOES NOT HAVE A
LOT OF GULF MOISTURE TO WORK WITH...BUT STRONG WARM ADVECTION
MAY AID IN BRIEF HEAVIER BURST OF SNOW.
MORE COLD AND SNOW SHOWERS FOR THE FIRST PART OF THE WEEKEND.
TEMPS MODERATE SOME FOR LATER SUNDAY INTO MONDAY.
SPEAKING OF TEMPS...COMBINATION OF WIND AND COLD SUPPORT
WIND CHILLS IN THE ADVISORY RANGE.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
WARM ADVECTION LIGHT SNOW REDUCING CONDITIONS TO MVFR/OCNL IFR
CIGS AND VSBYS ACROSS EASTERN AREAS. BANDS OF HEAVIER SNOW SHOWERS
AND A FEW SQUALLS WILL ACCOMPANY LOW PRESSURE AND ITS ASSOCIATED
COLD FRONT THROUGH THIS EVENING. THOUGH MUCH COLDER AIR WILL MOVE IN
/-20C AT 850MB/...MOISTURE AGAIN LIMITED WHICH WILL KEEP CIG/VSBY
REDUCTIONS AND SNOW IMPACTS CONFINED MAINLY TO HIGHER TERRAIN IN
THE WEST. COLD FLOW ACROSS MUCH WARMER LAKES WILL BRING LOWER
CLOUDS INTO KBFD-KJST STARTING LATER THIS MORNING AND ENHANCE SNOW
POTENTIAL IN THOSE SAME AREAS. BIGGEST SNOWFALL WILL BE CONFINED
CLOSER TO LAKE ERIE...BUT LIGHTER INTERMITTANT BANDED SNOWS WILL
IMPACT KBFD-KJST FOR NEXT COUPLE OF DAYS AS PERSISTENT NW FLOW
ESTABLISHES ITSELF. OCNL ENCROACHMENT OF MVFR POSS INTO CENTRAL
MTNS...WHILE DOWNSLOPE FLOW KEEPS WEATHER VFR IN THE EAST.
WINDS WILL PICK BACK UP TODAY A BIT...ESPECIALLY OVER WESTERN
HIGHER TERRAIN WHERE GUSTS TO 20-30 MPH WILL AGAIN BECOME COMMON.
OUTLOOK...
TUE-THU AM...SHSN WITH MVFR/OCNL IFR W MTNS...SCT/LIKELY SHSN IN
MVFR CENTRAL MTNS...SCT SHSN AND PRIMARILY VFR SE.
THU PM-FRI...MVFR/IFR POSSIBLE LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR PAZ004.
WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
WEDNESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
849 PM MST MON JAN 21 2013
.UPDATE...HAVE UPDATED FORECAST TO DROP LOW TEMPS IN A FEW
LOCATIONS. REST OF THE FORECAST REMAINS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 431 PM MST MON JAN 21 2013/
DISCUSSION...21Z SURFACE ANALYSIS HAD WARM FRONT FROM CENTRAL MT
INTO WESTERN NE. LIFT ALONG 140KT JET STREAK ON COLD SIDE OF WARM
FRONT CONTINUING TO PRODUCE -SN OVER WESTERN SD PER KUDX RADAR.
12Z GUIDANCE AS WELL AS 18Z RAP SHOW ACTIVITY WANING AND SLOWLY
MOVING EAST TONIGHT. MOST ACTIVITY SHOULD EXIT CWA BY 12Z TUESDAY.
ACCUMULATIONS WILL CONTINUE TO BE MINOR. TEMPERATURES NEAR
GUIDANCE LOOK REASONABLE.
TUESDAY...UPPER RIDGE BUILDS EAST INTO THE ROCKIES AS SURFACE WARM
FRONT WORKS ACROSS WESTERN SD. HOW FAR EAST IT GOES IT THE MAIN
QUESTION...BUT IT SHOULD AT LEAST MAKE IT TO A K2WX TO KVTN LINE.
BEHIND IT TEMPERATURES SHOULD REACH WELL INTO THE 30S TO LOWER 40S
GIVEN FORECAST LOWER TROPOSPHERIC PROFILES.
WEDNESDAY...UPPER RIDGE MOVES OVER THE NORTHERN PLAINS AND
DEAMPLIFIES AS SHORTWAVE TROUGHS MOVES INTO THE NORTHERN ROCKIES.
INITIAL TROUGH/COOL FRONT WILL SLIDE INTO THE CWA. TEMPERATURES
SHOULD ROCKET INTO THE 40S OVER WY/HIGHER ELEVATIONS...BUT AS AN
EASTERLY COMPONENT TO THE SURFACE WIND DEVELOPS ON THE SD PLAINS
BY AFTERNOON...EXPECT TEMPERATURES RISES TO BE HALTED MAINLY IN
THE 20S. ST/BR MAY DEVELOP WEDNESDAY NIGHT GIVEN WEAK UPSLOPE FLOW
AHEAD OF NEXT FRONT FOR THURSDAY.
EXTENDED...A FAST MOVING CLIPPER SYSTEM WILL MOVE THROUGH THE NRN
PLAINS ON THURSDAY...BRINGING GUSTY NORTHWEST WINDS ALONG WITH
CHANCES FOR PRECIP MAINLY OVER THE NRN CWA. RIDGE OVER THE WRN CONUS
WILL THEN SLOWLY SHIFT EAST...BRINGING MILD AND DRY CONDITIONS FOR
THE WEEKEND. MODELS START TO DIVERGE ON A SOLUTION TO START NEXT
WEEK THOUGH OVERALL PATTERN REMAINS UNSETTLED...SO WILL LEAVE LOW
POPS IN FOR NOW.
&&
AVIATION...00Z TAF FORECASTS
SNOW FLURRIES ON THE WESTERN SD PLAINS INTO EXTREME NERN WY WILL
CONTINUE THROUGH EARLY EVENING BRINGING MAINLY MVFR
CIGS/VIS...THOUGH LCL IFR VIS WILL BE POSSIBLE. -SN WILL SLOWLY
SHIFT EAST OVERNIGHT WITH CIGS IMPROVING TO VFR.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
431 PM MST MON JAN 21 2013
.DISCUSSION...21Z SURFACE ANALYSIS HAD WARM FRONT FROM CENTRAL MT
INTO WESTERN NE. LIFT ALONG 140KT JET STREAK ON COLD SIDE OF WARM
FRONT CONTINUING TO PRODUCE -SN OVER WESTERN SD PER KUDX RADAR.
12Z GUIDANCE AS WELL AS 18Z RAP SHOW ACTIVITY WANING AND SLOWLY
MOVING EAST TONIGHT. MOST ACTIVITY SHOULD EXIT CWA BY 12Z TUESDAY.
ACCUMULATIONS WILL CONTINUE TO BE MINOR. TEMPERATURES NEAR
GUIDANCE LOOK REASONABLE.
TUESDAY...UPPER RIDGE BUILDS EAST INTO THE ROCKIES AS SURFACE WARM
FRONT WORKS ACROSS WESTERN SD. HOW FAR EAST IT GOES IT THE MAIN
QUESTION...BUT IT SHOULD AT LEAST MAKE IT TO A K2WX TO KVTN LINE.
BEHIND IT TEMPERATURES SHOULD REACH WELL INTO THE 30S TO LOWER 40S
GIVEN FORECAST LOWER TROPOSPHERIC PROFILES.
WEDNESDAY...UPPER RIDGE MOVES OVER THE NORTHERN PLAINS AND
DEAMPLIFIES AS SHORTWAVE TROUGHS MOVES INTO THE NORTHERN ROCKIES.
INITIAL TROUGH/COOL FRONT WILL SLIDE INTO THE CWA. TEMPERATURES
SHOULD ROCKET INTO THE 40S OVER WY/HIGHER ELEVATIONS...BUT AS AN
EASTERLY COMPONENT TO THE SURFACE WIND DEVELOPS ON THE SD PLAINS
BY AFTERNOON...EXPECT TEMPERATURES RISES TO BE HALTED MAINLY IN
THE 20S. ST/BR MAY DEVELOP WEDNESDAY NIGHT GIVEN WEAK UPSLOPE FLOW
AHEAD OF NEXT FRONT FOR THURSDAY.
EXTENDED...A FAST MOVING CLIPPER SYSTEM WILL MOVE THROUGH THE NRN
PLAINS ON THURSDAY...BRINGING GUSTY NORTHWEST WINDS ALONG WITH
CHANCES FOR PRECIP MAINLY OVER THE NRN CWA. RIDGE OVER THE WRN CONUS
WILL THEN SLOWLY SHIFT EAST...BRINGING MILD AND DRY CONDITIONS FOR
THE WEEKEND. MODELS START TO DIVERGE ON A SOLUTION TO START NEXT
WEEK THOUGH OVERALL PATTERN REMAINS UNSETTLED...SO WILL LEAVE LOW
POPS IN FOR NOW.
&&
.AVIATION...00Z TAF FORECASTS
SNOW FLURRIES ON THE WESTERN SD PLAINS INTO EXTREME NERN WY WILL
CONTINUE THROUGH EARLY EVENING BRINGING MAINLY MVFR
CIGS/VIS...THOUGH LCL IFR VIS WILL BE POSSIBLE. -SN WILL SLOWLY
SHIFT EAST OVERNIGHT WITH CIGS IMPROVING TO VFR.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...HELGESON
LONG TERM...77
AVIATION...423
AREA FORECAST DISCUSSION
NWS AMARILLO TX
310 PM CST SUN JAN 20 2013
.DISCUSSION...
THROUGH TONIGHT: MAIN CONCERN TONIGHT REVOLVES AROUND POTENTIAL
DEVELOPMENT OF FREEZING FOG VS. LOW STRATUS. A DRY COLD FRONT
LOCATED ALONG THE CANADIAN RIVER VALLEY IS TRUCKING SOUTHWARD THIS
AFTERNOON. STRONG NORTHERLY WINDS HAVE DEVELOPED BEHIND THE FRONT
WITH A FEW GUSTS UP TO 35 MPH. THIS NORTHERLY SURGE OF GUSTY WINDS
WILL CONTINUE TO PUSH SOUTHWARD THROUGH THE AFTERNOON AND EVENING
HOURS, BUT IT SHOULD DIMINISH IN INTENSITY NEAR SUNSET. LOW-LEVEL
MOISTURE IS EXPECTED TO POOL BEHIND THE FRONT TONIGHT, BUT MODEL
GUIDANCE SHOWS VARYING DEGREES OF MOISTURE CONTENT. THE LATEST RUC
AND HRRR HAVE BACKED OFF ON THE POTENTIAL FOR WIDESPREAD FREEZING
FOG, BUT THE GFS AND NAM CONTINUE TO INDICATE THIS POTENTIAL. GIVEN
THE SYNOPTIC PATTERN, THIS SETUP IS LOCALLY FAVORABLE FOR SOME
PATCHY (FREEZING) FOG, SO WE LEFT THIS IN THE FORECAST. WE EXPECT
FREEZING FOG TO DEVELOP BETWEEN 3 AM ACROSS THE EASTERN PANHANDLES
AND SPREAD WESTWARD. OTHER MODEL GUIDANCE, INCLUDING THE TEXAS TECH
WRF, INDICATES THAT LOW STRATUS WILL BE MORE FAVORED THAN FOG. DUE
TO THESE UNCERTAINTIES, WE INCLUDED BOTH INCREASING CLOUDS AND PATCHY
FREEZING FOG IN THE FORECAST, BUT OUR FORECAST CONFIDENCE IS LOW.
OVERNIGHT LOW TEMPERATURES WILL RANGE FROM THE UPPER TEENS TO UPPER
20S. THE POTENTIAL FOR FREEZING DRIZZLE THAT WE DISCUSSED YESTERDAY
HAS DIMINISHED AS THE DEPTH OF THE MOIST LAYER WILL BE LESS THAN
2000 FEET.
MARTIN LUTHER KING, JR. DAY-NIGHT: ANY FREEZING FOG THAT DEVELOPS
OVERNIGHT SHOULD DISSIPATE BY 10 AM. LOW CLOUDS, IF THEY DEVELOP,
COULD HANG TOUGH INTO THE EARLY AFTERNOON HOURS, ESPECIALLY ACROSS
THE SOUTHEASTERN TEXAS PANHANDLE. SURFACE WINDS WILL QUICKLY SHIFT TO
THE SOUTH BY THE AFTERNOON HOURS, BUT HIGH TEMPERATURES WILL BE ABOUT
10-15 DEGREES COLDER THAN TODAY DUE TO THE MODIFIED ARCTIC AIR MASS.
TUESDAY-SUNDAY: A BACKDOOR COLD FRONT WILL SNEAK INTO THE
NORTHEASTERN HALF OF THE FORECAST AREA TUESDAY MORNING AND MAY BE
SLOW TO RETREAT NORTHWARD. THIS SHOULD KEEP AN UPSLOPE COMPONENT TO
THE WINDS FOR MUCH OF THE DAY. AS A RESULT, WE COOLED HIGHS OFF
SEVERAL DEGREES, AND THERE IS A POSSIBILITY WE MAY STILL BE TOO WARM.
THIS FRONT WILL LIFT OUT OF THE FORECAST AREA ON WEDNESDAY AS UPPER
RIDGING BUILDS ACROSS THE AREA. HIGHS ON WEDNESDAY ARE EXPECTED TO
WARM INTO THE LOWER 60S TO POSSIBLY NEAR 70. AN UPPER TROUGH MOVING
INTO NORTHERN PLAINS ON THURSDAY WILL SWING ANOTHER DRY COLD FRONT
SOUTHWARD. WE SPED UP THE TIMING OF THE FRONT GIVEN THAT IT WILL ALSO
BE A STRONG FRONT. AS A RESULT, HIGHS FOR THURSDAY HAVE BEEN TRIMMED
DOWNWARD AND WIND SPEEDS INCREASED, ESPECIALLY BEHIND THE FRONT.
COOLER TEMPERATURES WILL RETURN FOR FRIDAY, BUT A WARMING TREND WILL
RESUME FOR NEXT WEEKEND.
JACKSON
&&
.FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE ANTICIPATED
MONDAY THROUGH WEDNESDAY AS RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE 20 PERCENT AND/OR 20-FOOT WINDS WILL REMAIN BELOW 15 MPH.
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE WESTERN
TWO THIRDS OF THE PANHANDLES ON THURSDAY AS DRY NORTHERLY WINDS
INCREASE. ELEVATED FIRE WEATHER CONDITIONS WILL ALSO BE POSSIBLE
ACROSS THE FAR WESTERN PANHANDLES ON SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 23 50 28 58 30 / 0 0 0 0 0
BEAVER OK 19 47 23 51 24 / 0 0 0 0 0
BOISE CITY OK 18 51 25 58 26 / 0 0 0 0 0
BORGER TX 24 50 29 57 32 / 0 0 0 0 0
BOYS RANCH TX 24 50 27 59 28 / 0 0 0 0 0
CANYON TX 25 50 27 59 27 / 0 0 0 0 0
CLARENDON TX 26 48 30 58 34 / 0 0 0 0 0
DALHART TX 19 49 23 58 24 / 0 0 0 0 0
GUYMON OK 19 51 24 56 26 / 0 0 0 0 0
HEREFORD TX 26 50 25 60 28 / 0 0 0 0 0
LIPSCOMB TX 21 48 22 52 26 / 0 0 0 0 0
PAMPA TX 22 48 29 57 31 / 0 0 0 0 0
SHAMROCK TX 25 48 26 56 30 / 0 0 0 0 0
WELLINGTON TX 27 47 27 57 32 / 0 0 0 0 0
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
EA/JJ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
930 PM CST MON JAN 21 2013
.UPDATE...
TWEAKED CLOUD COVER DOWN WITH GENERALLY CLEAR SKIES EXPECTED
OVERNIGHT THOUGH TEMPERATURES CURRENTLY BEING HELD UP SOME BY LOW-
LEVEL MIXING...THOUGH WINDS HAVE EASED FROM DAYTIME GUSTINESS. THE
RELATIVE WEAKENING OF THE WINDS...ALONG WITH THE CURRENT
TEMPERATURES...HAVE WIND CHILL VALUES REMAINING JUST ABOVE
ADVISORY CRITERIA OVER MOST OF THE CWA....THOUGH GETTING CLOSE.
PER SHORT TERM/RAPID UPDATE MODELS
...DO EXPECT TEMPERATURES TO FALL OVERNIGHT...AND WITH THE SURFACE
GRADIENT SUPPORTING 10 TO 15 MPH WINDS...WILL SEE THE 20 BELOW TO
30 BELOW WIND CHILL VALUES CURRENTLY IN THE FORECAST OVERNIGHT
INTO THE TUESDAY MORNING RUSH.
&&
.AVIATION/06Z TAFS/...
CU RAPIDLY DIMINISHED OVER THE CWA AROUND/AFTER SUNSET...THOUGH
GETTING SOME OF THE LAKE CLOUDS BACKING UP INTO THE FAR EAST AHEAD
OF WEAK SURFACE TROUGH...WHICH SHOULD PUSH SOUTH OF SOUTHERN
WISCONSIN BY/AROUND 06Z. WITH LATEST NAM LOW-LEVEL RH FORECASTS
INDICATING LESS OF A CHANCE FOR MVFR CIGS TUESDAY...THOUGH LATEST
MET GUIDANCE HAS OVERCAST VFR. FEEL THIS A BIT OVERDONE AND WILL
AWAIT THE LATEST GFS BUT EXPECT VFR CONDITIONS THROUGH THE
PERIOD.
&&
.MARINE...
THOUGH GUSTS ARE CURRENTLY JUST BELOW CRITERIA AT THE REPORTING
SHORELINE OB SITES DUE TO OFFSHORE DIRECTION...BETTER MIXING OVER
THE RELATIVELY WARMER LAKE WATERS WILL EASILY TAP SMALL CRAFT
CRITERIA WINDS JUST OFF THE SURFACE. WILL CONTINUE HEADLINE AS IS
FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 255 PM CST MON JAN 21 2013/
TONIGHT AND TUESDAY - CONFIDENCE...MEDIUM TO HIGH
CORRIDOR OF ARCTIC CHILL CONTINUES THIS PERIOD. TIGHT PRESSURE
GRADIENT CONTINUES TONIGHT INTO AT LEAST EARLY TUESDAY. NOT THE BEST
RADIATIONAL CONDITIONS WITH THE MIXING. DECENT AGREEMENT AMONGST THE
MODELS ON 925 TEMPS OF -24 TO -26C. WILL DROP BELOW ZERO CWA WIDE
YIELDING DANGEROUS WIND CHILLS OF 20 TO 30 BELOW ZERO. RAP SOUNDINGS
SHOW A FAIRLY WELL MIXED LOWEST 2K FEET THROUGH 4 AM OR SO...THEN
SOUNDINGS SHOW LESS MIXING. DANGEROUS CONDITIONS THROUGH THE MORNING
COMMUTE GIVEN THE BITTER AIRMASS/WIND CHILLS. MODELS IN DECENT AGREEMENT
TO BRING READINGS ABOVE ZERO INTO THE LOW/MID SINGLE DIGITS FOR
TUESDAY. GRADIENT SHOWS SOME SLACKENING INTO THE AFTERNOON SO GOING
MIDDAY EXPIRATION SEEMS REASONABLE.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
EXPECT INCREASING CLOUDS LATER TUESDAY NIGHT AS A SHOT OF WARM
ADVECTION APPROACHES. THIS IS AHEAD OF A WEAK TROF/COLD FRONT
DROPPING IN FROM THE NORTHWEST. THE EARLY CLEAR SKIES TUESDAY
EVENING ALONG WITH LIGHT WINDS UNDER A RIDGE OF HIGH PRESSURE WILL
ALLOW TEMPS TO PLUMMET QUICKLY DURING THE EVENING. LOWS WILL RANGE
FROM 4 ABOVE TO 4 BELOW...THOUGH WIND CHILLS WON/T BE MUCH OF A
FACTOR. THE WARM ADVECTION WITH SOME ADDITIONAL MOISTURE COULD
BRING SOME SCATTERED FLURRIES TO THE AREA ON WEDNESDAY. THERE IS
AN OUTSIDE CHANCE A FEW SITES WILL MEASURE...BUT NOT ENOUGH TO
HAVE POPS ABOVE 14 PERCENT ATTM.
WEDNESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE WEAK COLD FRONT SHOULD HAVE EXITED SOUTHERN WISCONSIN BY
EVENING. HIGH PRESSURE AND COLD AIR SETTLE IN FOR THE NIGHT. SKIES
WILL ALSO CLEAR. SO...EXPECT LOWS IN THE SINGLE DIGITS THURSDAY
MORNING.
THURSDAY AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
THE MODELS HAVE BEEN STRUGGLING ON TIMING WITH REGARD TO LOW
PRESSURE MOVING THROUGH THE REGION LATE IN THE WEEK...LIKELY
BRINGING A LITTLE ACCUMULATING SNOW. THIS WOULD BE ON THE ORDER OF
1/2 TO POSSIBLY 2 INCHES...THURSDAY NIGHT INTO FRIDAY. NOTHING
MAJOR. THE MID LEVELS FEATURE A DECENT SHORT WAVE PUSHING OUT OF
THE PACIFIC NORTHWEST ON WEDNESDAY...THEN PHASING WITH THE LARGE
TROF OVER EASTERN CANADA ON THURSDAY. AS IT DIVES INTO THE
NORTHERN U.S. A RATHER LARGE LONG WAVE TROF FORMS FROM HUDSON BAY
CANADA TO NORTHERN IOWA BY FRIDAY MORNING. SFC CYCLOGENESIS OCCURS
OVER BOTH THE NORTHERN PLAINS AND THE SOUTHERN MS
VALLEY...EVENTUALLY THEY MERGE INTO ONE SFC LOW THAT MOVES WELL
SOUTH OF WI...TOWARD THE EAST COAST.
THE MODELS HAVE SLOWED ALL THIS DOWN BY A GOOD 6 TO 12 HOURS. HIGH
PRESSURE WILL KEEP IT QUIET FOR MOST OF THURSDAY. THEN THE WARM
AIR ADVECTION ARRIVES THURSDAY AFTERNOON INTO THURSDAY NIGHT...AND
THAT/S GOOD FOR A CHANCE OF SNOW. THEN THE WEAK NORTHERN LOW
SLIDES BY ON FRIDAY...KEEPING THE CHANCE OF SNOW ALIVE. THIS LOW
THEN MERGES WITH THE SOUTHERN LOW...BRINGING A SLOW END TO THE
LIGHT SNOW BY FRIDAY NIGHT.
AGAIN...ANY SNOW AMOUNTS WILL LIKELY BE KEPT AT BETWEEN 1/2 TO
MAYBE 2 INCHES.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM.
HIGH PRESSURE ARRIVES BY SATURDAY FOR A QUIET STRETCH INTO EARLY
SUNDAY. THEN A WEAK TROF PUSHES IN FROM THE WEST AND THIS COULD
LEAD TO SOME LIGHT SNOW CHANCES LATER ON SUNDAY.
AVIATION/00Z TAFS/...NW WINDS RAMPED UP WITH TIGHT PRESSURE
GRADIENT BETWEEN PLAINS SURFACE RIDGE AND LOW PRESSURE OVER EASTERN
UPPER MICHIGAN. STILL QUITE A BIT OF MVFR IN THE COLD CYCLONIC
REGIME. WOULD EXPECT KEEPING SOME OF THIS AROUND TONIGHT. LOW LEVEL
RH PROGS SHOWING CONSIDERABLY LESS CU POTENTIAL TUESDAY.
MARINE...NO CHANGE TO SMALL CRAFT ADVISORY A WINDS EXPECTED TO
REMAIN GUSTY WITH TIGHT PRESSURE GRADIENT. EXPECT WINDS TO EASE BY
MIDDAY TUESDAY AS GRADIENT LOOSENS UP SOME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR WIZ046-047-051-
052-056>060-062>072.
LM...SMALL CRAFT ADVISORY UNTIL NOON CST TUESDAY FOR LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...DAVIS
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
749 PM CST MON JAN 21 2013
.UPDATE...THE CORE OF THE COLDEST POOL OF AIR WL MOVE ACROSS THE
AREA THIS EVENING...THEN BEGIN EDGING OFF TO THE E LATE TNGT. BUT
THERE WL STILL BE SOME NOCTURNAL DROP OFF IN TEMPS TNGT...SO VERY
COLD READINGS ARE LIKELY BY TOMORROW MORNING.
UNLIKE YDA NGT WHEN SECONDARY PUSH OF CAA LATER IN THE NGT
STEEPENED LOW-LEVEL LAPSE RATES AND CAUSED WINDS TO PICK UP LATE
AT NGT AND DURING THE EARLY MORNING HRS...THINK WE WL SETTLE INTO
A MORE STEADY STATE 7-14 MPH WIND IN MOST AREAS OVERNIGHT. WINDS
WL PROBABLY DROP OUT AT TIMES IN SOME OF THE MORE PROTECTED AREAS
OF N-C WI. THAT WL PROBABLY CAUSE WIND CHILL INDICES TO BOUNCE
ARND SOME...AND THEY AREN/T GOING TO FIT CLEANLY INTO OUR
ADVISORY/WARNING CRITERIA AT ALL TIMES. BUT CURRENT HEADLINES SEEM
ON TARGET FOR HILIGHTING THE DANGER OF FROSTBITE TO ANYONE GOING
OUTDOORS WITHOUT TAKING APPROPRIATE PRECAUTIONS...SO SEE NO REASON
TO MAKE ANY CHANGES.
UPDATED PRODUCT SUITE OUT ASAP.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 448 PM CST MON JAN 21 2013...
SHORT TERM...TONIGHT AND TUESDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE STRETCHING SOUTHEAST ACROSS THE GREAT PLAINS EARLY THIS
AFTERNOON. WEAK SHORTWAVE IS DROPPING ACROSS THE STATE WHICH IS
CONTRIBUTING TO A STRATO-CU FIELD...WITH THE HELP FROM STEEP LOW
LEVEL LAPSE RATES. SCT FLURRIES ARE FALLING OUT OF THIS STRATO-CU
DECK FROM THE SOUTHERN FOX VALLEY TO CENTRAL AND NORTH-CENTRAL
WISCONSIN. TEMPERATURES AND WIND CHILL READINGS HAVE HARDLY BUDGED
SINCE EARLIER THIS MORNING...AND PLENTY OF 30-35 BELOW WIND CHILL
READINGS REMAIN OVER NORTH-CENTRAL WISCONSIN. FORECAST CONCERNS
INCLUDE CLOUD TRENDS AND WIND CHILL HEADLINES.
TONIGHT...ARCTIC HIGH PRESSURE WILL BE BUILDING SOUTHEAST ACROSS THE
NORTHERN MISSISSIPPI VALLEY THROUGH THE NIGHT. SHORTWAVE TROUGH
OVERHEAD WILL BE EXITING THE REGION BY LATE THIS AFTERNOON OR EARLY
THIS EVENING. WITH LOSS OF A SMALL DIURNAL COMPONENT...AM COUNTING
ON INCREASING SUBSIDENCE TO HELP GRADUALLY DISSIPATE MUCH OF THE
STRATO-CU FIELD OVER CENTRAL AND EAST-CENTRAL WISCONSIN THIS
EVENING. NORTH-CENTRAL WISCONSIN MAY NOT CLEAR OUT MUCH AT ALL...AS
LOW LEVEL WINDS VEER AROUND SLIGHTLY TO THE NORTHWEST AND PUSH LAKE
EFFECT CLOUDS SOUTHEAST BENEATH A FAIRLY SHARP INVERSION. TOO COLD
FOR MUCH ACCUMS...BUT POSSIBLY UP TO AN INCH OVER THE FAR NORTHERN
PART OF THE COUNTY. THE CLEARING SKIES WILL HELP TEMPS BECOME
COLDER TONIGHT COMPARED TO LAST NIGHT...BUT THIS WILL BE OFFSET BY A
WEAKENING PRESSURE GRADIENT AND WIND SPEEDS. APPARENT TEMP GRIDS
SHOW WIND CHILLS FALLING ONLY A FEW DEGREES THIS EVENING...BUT
READINGS HAVE REMAINED STEADY ACROSS NORTH-CENTRAL WISCONSIN
TODAY...SO WILL NOT TAKE MUCH OF A FALL TO REACH WARNING CRITERIA.
AFTER COORDINATING WITH SURROUNDING OFFICES...WILL ISSUE A WIND
CHILL WARNING WHERE AM MOST CONFIDENT IN REACHING CRITERIA...FROM
LINCOLN AND LANGLADE TO VILAS AND FOREST COUNTY STARTING THIS
EVENING AND GOING THROUGH MID-MORNING TUESDAY.
TUESDAY...ARCTIC HIGH PRESSURE WILL BE SLIDING TO THE OHIO VALLEY.
CORE OF THE COLDEST AIR WILL BE SHIFTING TO THE NORTHEAST...ALONG
WITH THE HIGHER LOW LEVEL HUMIDITY. BUT WILL ALREADY BE OFF TO A
VERY COLD START SO TEMPS WILL NOT BE SIGNIFICANTLY WARMER THAN
TODAYS READINGS. WITH WINDS BACKING TO THE WEST...SHOULD SEE MORE
SUNSHINE THAN TODAY. WINDS WILL ALSO BE LIGHTER...AND WIND CHILL
READINGS SHOULD BE IMPROVING RAPIDLY BY MID TO LATE MORNING. WILL
CONTINUE TO RUN WIND CHILL HEADLINES TO 18Z. HIGHS RANGING FROM 5
BELOW NORTH TO ABOUT 4 ABOVE NEAR LAKE MICHIGAN.
LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. PRIMARY ISSUE
CONTINUES TO BE THE DURATION OF THE COLD AIR THIS WEEK FOLLOWED BY
A CLIPPER TYPE SYSTEM LATER THIS WEEK.
COLD AIR INTRUSION CONTINUES TUESDAY NIGHT WITH THE LIKELY CHANCE
OF ADDITIONAL WIND CHILL HEADLINES ACROSS AT LEAST THE NORTH HALF
OF THE FORECAST AREA. A WEAK TROUGH IS PROGGED DROPS OVER THE GREAT
LAKES REGION IN THE NORTHWEST FLOW WED INTO WED EVENING...FOLLOWED
WITH ANOTHER BRIEF PERIOD OF CAA INTO THURSDAY MORNING.
THIS BIT LONGER DURATION OF COLDER AIR INTO WEDNESDAY NIGHT
PRECEDES THE TREND OF SLOWING DOWN THE CLIPPER TYPE SYSTEM FOR
LATER THURSDAY AND INTO FRIDAY MORNING...WHICH IS SUPPORTED BY THE
LAST FEW MODEL RUNS. WOULD NOT BE SURPRISED WITH LATER RUNS
INDICATING THE CLIPPER WILL LINGER MORE INTO FRIDAY AS THIS
CLIPPER SYSTEM PHASES WITH A SOUTHERN STREAM SYSTEM. COULD SEE A
FEW INCHES OF SNOW BY FRIDAY OVER MOST LOCATIONS.
AFTER A BRIEF PERIOD OF CAA IN THE WAKE OF THE CLIPPER...GRADUALLY
MODERATING TEMPERATURES TO NEAR SEASONAL NORMS STILL EXPECTED FOR
THE WEEKEND AND INTO MONDAY.
WAA FOR SUNDAY ALONG WITH A H850 TROUGH TRACKING OVER THE AREA
MAY WILL PROVIDE A CHANCE FOR LIGHT SNOW OR FLURRIES.
LAKE EFFECT POTENTIAL. THE CHANCE FOR LAKE EFFECT SNOWS INCREASE
TOWARD WEDNESDAY NIGHT OVER FAR NORTHERN WISCONSIN AS THE SHORT
WAVE TROUGH SWINGS THROUGH AND WINDS TURN BRIEFLY NORTHWEST AGAIN.
NORTHWEST WINDS WILL NOT LAST LONG AS THE COLD SURFACE HIGH
DROPS INTO THE REGION. BUT WINDS BEGIN TO TURN MORE EASTERLY
THURSDAY INTO THURSDAY NIGHT TO INCREASE THE POTENTIAL OF MORE
SNOW SHOWERS ALONG LAKE MICHIGAN..ESPECIALLY AS THE WEAK CLIPPER
TRACKS THROUGH TO PROVIDE SOME LIFT. COULD HAVE HIGHER SNOW
AMOUNTS ALONG THE LAKE MICHIGAN SHORELINE THURSDAY NIGHT INTO
FRIDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE. VFR CONDITIONS EXPECTED AS
ARCTIC AIR DOMINATES THE AREA. THE ONLY EXCEPTION WL BE NR THE
UPPER MICHIGAN BORDER WHERE CLDS OFF LAKE SUPERIOR WL DROP CIGS
INTO MVFR CAT AT TIMES.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR WIZ012-013-
020>022-030-031-035>040-045-048>050-073-074.
WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ005-010-011-018-
019.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
526 PM CST MON JAN 21 2013
.SHORT TERM...TONIGHT THROUGH THURSDAY
300 PM CST MON JAN 21 2013
MAIN FORECAST CONCERNS ARE ON HOW QUICK THE CURRENT ARCTIC AIRMASS
MODIFIES...IF SNOW CAN FORM OFF OF LAKE PEPIN AGAIN TONIGHT...AND
LIGHT SNOW CHANCES TUESDAY NIGHT THROUGH THURSDAY.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF THE U.S. INTO BRITISH
COLUMBIA...WHILE DEEP TROUGHING WAS IN PLACE OVER SOUTHEAST CANADA
INTO THE WESTERN GREAT LAKES REGION. UNDER THIS DEEP TROUGHING...
850MB TEMPS WERE -25C AT MPX...-27C AT GRB AND -35C AT INL PER 12Z
SOUNDINGS...OR 2 TO 2.5 STANDARD DEVIATIONS BELOW NORMAL. THESE COLD
READINGS...COMBINED WITH A NORTHWEST BREEZE RESULTING FROM A TIGHT
PRESSURE GRADIENT BETWEEN LOW PRESSURE IN NORTHERN LAKE HURON AND
ARCTIC HIGH PRESSURE IN THE DAKOTAS...HAVE RESULTED IN TEMPERATURES
ONLY SLOWLY RISING TODAY. STILL...WITH MOST OF THE AREA EXCLUDING
NORTH OF HIGHWAY 10 HAVING BARE GROUND...AND SUNSHINE THROUGH SOME
CONVECTIVELY INDUCED STRATOCUMULUS UNDER THE 850MB THERMAL TROUGH
HAS ALLOWED TEMPERATURES SOUTH OF HIGHWAY 10 TO CLIMB TO OR SLIGHTLY
ABOVE ZERO. WIND CHILLS ARE STILL 15 TO 30 BELOW...THOUGH. TO THE
WEST...RAP ANALYSIS SHOWED A 140KT JET AT THE TROPOPAUSE DROPPING
DOWN THROUGH THE EASTERN DAKOTAS. ALONG AND WEST OF THIS UPPER JET
STREAK...MID AND HIGH CLOUDS ARE PRESENT...REFLECTING THE UPPER
LEVEL MOISTURE SEEN ON WATER VAPOR. 850MB TEMPS WARM QUITE A BIT TOO
WEST OF THE UPPER JET...AS EXPECTED THROUGH THE THERMAL WIND
RELATIONSHIP...CLIMBING FROM -23C AT BIS TO -14C AT UNR PER 12Z
SOUNDINGS.
TONIGHT AND TUESDAY...THE UPPER LEVEL PATTERN IS NOT FORECAST TO
CHANGE MUCH OVER THE NEXT 24 HOURS...WITH PERHAPS ONLY A SLIGHT
EASTWARD PROGRESSION TO THE WESTERN RIDGE AND DEEP TROUGH.
HOWEVER...THIS PROGRESSION WILL BE ENOUGH TO SLIDE THE ARCTIC HIGH
OVER THE DAKOTAS INTO THE FORECAST AREA BY 00Z WEDNESDAY...ALONG
WITH THE UPPER JET STREAK AND THE MID/HIGH CLOUDS ACCOMPANYING THE
JET STREAK. OF INTEREST TONIGHT IS TO SEE IF ANOTHER NARROW BAND CAN
FORM OFF LAKE PEPIN...WHICH WILL DEPEND ON IF THE LAKE WAS ABLE TO
FREEZE OVER. LAST NIGHT...WITH THE ARCTIC AIR FLOWING IN...A NARROW
BAND FORMED WITH VISIBILITIES LESS THAN 1/4 MILE. SEE OUR NEWS STORY
ON OUR WEBSITE FOR MORE ABOUT THE BAND. THE 20.12Z HIRES-ARW
YESTERDAY SHOWED THE BAND HAPPENING LAST NIGHT...THOUGH THE THOUGHT
AT THE TIME WAS THAT THE ENTIRE MISSISSIPPI RIVER SYSTEM WAS FROZEN
OVER. THE 21.06Z/12Z HIRES-ARW SHOW A BAND FORMING AGAIN TONIGHT...
AND GIVEN THAT IT HAS STAYED BREEZY TODAY TO HELP PREVENT ICE
FORMATION ON LAKE PEPIN...HAVE THUS INCLUDED SOME SMALL
PRECIPITATION CHANCES FOR THE BAND BETWEEN 06-15Z TUESDAY. OTHERWISE
TEMPERATURES AND WIND CHILLS ARE THE MAIN ISSUE. THE 925MB THERMAL
TROUGH REMAINS IN PLACE TONIGHT WITH READINGS OF -24 TO -28C...
COLDEST NORTH OF I-94. SINCE WE MAINTAIN A BREEZE MOST OF THE
NIGHT...THE BOUNDARY LAYER SHOULD REMAIN MIXED AT LEAST UP TO 950MB
IF NOT TO THAT 925MB LEVEL...RESULTING IN LOWS BETWEEN 5 AND 15
BELOW. COLDEST READINGS WOULD OCCUR NORTH OF HIGHWAY 10 WHERE A
LITTLE SNOW PACK EXISTS. ON TUESDAY...GRADUAL WARMING TAKES PLACE TO
THE 925MB TEMPS WITH THE SHIFT EAST OF THE DEEP TROUGHING...CLIMBING
TO -19 TO -23C BY 21Z. THUS...WE SHOULD SEE HIGHS JUST A FEW DEGREES
WARMER THAN THOSE TODAY UNDER MOSTLY SUNNY SKIES.
TUESDAY NIGHT AND WEDNESDAY...THERE HAS BEEN A TREND TO SLOW UP THE
PATTERN MORE DURING THIS TIME PERIOD COMPARED TO PREVIOUS
FORECASTS...AND TO SOME DEGREE DRAMATICALLY. THE REASON FOR THE SLOW
DOWN IS THAT MODELS HAVE FOCUSED ON A POTENT SHORTWAVE DROPPING
SOUTH OUT OF NORTHERN MANITOBA. ALL MODELS HAVE IT DIGGING DOWN INTO
UPPER MICHIGAN AND EVEN NORTHERN WISCONSIN BY 00Z THURSDAY. THIS
HOLDS UP THE RIDGE OVER THE WESTERN U.S. FROM PUSHING EAST. IN
ADDITION...WE END UP NOW SEEING ANOTHER ARCTIC HIGH DROPPING DOWN
INTO THE RED RIVER VALLEY OF NORTH DAKOTA...WITH A COLD FRONTAL
PASSAGE COMING THROUGH THE FORECAST AREA AHEAD OF IT DURING THE DAY
WEDNESDAY. PRIOR TO THIS FRONTAL PASSAGE...THE 21.12Z CANADIAN/UKMET
AND 21.00Z ECMWF DEPICT A BAND OF LIGHT QPF COMING INTO THE FORECAST
AREA FROM THE WEST...REACHING ABOUT THE MISSISSIPPI RIVER SOUTH OF
I-90 BY 12Z WEDNESDAY. THIS BAND IS THAT SAME BAND OF MID/HIGH
CLOUDS TRAVERSING THE PLAINS WHICH ENDS UP MARCHING EAST. GIVEN THAT
THERE ARE OBSERVATIONS OF SNOW UNDER THE BAND...HAVE MAINTAINED
FLURRIES AND INCLUDED 20 PERCENT CHANCES. THE BAND DOES WEAKEN OVER
TIME AS THAT POTENT SHORTWAVE DIGS SOUTH...AND AFTER 18Z ANY
FLURRIES ASSOCIATED WITH IT SHOULD HAVE SHIFTED OFF TO THE
SOUTHEAST. SOME FLURRY ACTIVITY COULD OCCUR NORTH OF I-94 IN THE
AFTERNOON WITH THE SHORTWAVE. WITH MORE CLOUDS TUESDAY NIGHT...
EXPECT A WARMER NIGHT...AND IN FACT TEMPERATURES COULD RISE AFTER
MIDNIGHT AS 925MB TEMPS WARM WITH THE SOUTHWEST WINDS AHEAD OF THE
FRONT. THE WARMER NIGHT PLUS 925MB TEMPS OF -12 TO -18C AT 18Z
WEDNESDAY SHOULD YIELD HIGHS IN THE TEENS TO LOW 20S IN MOST
LOCATIONS.
WEDNESDAY NIGHT AND THURSDAY...GOOD AGREEMENT EXISTS AMONG THE
21.12Z GFS/ECMWF/UKMET/CANADIAN OF TAKING A POTENT SHORTWAVE TROUGH
COMING INTO THE PACIFIC NORTHWEST AT 00Z THURSDAY ACROSS THE
NORTHERN ROCKIES...THEN INTO THE DAKOTAS BY 00Z FRIDAY. AGAIN...THIS
IS QUITE A BIT SLOWER THAN YESTERDAYS FORECAST. THE NAM IS AN
OUTLIER BY ALMOST BRINGING IT INTO MN...BUT IS NOT DEEP ENOUGH
DIGGING THE WEDNESDAY SHORTWAVE. GIVEN THE SLOWER TREND...THE SPREAD
OF DPVA AND WARM ADVECTION / FRONTOGENESIS INDUCED SNOW DOWNSTREAM
IS SLOWER TOO...WITH DRY CONDITIONS NOW INDICATED THROUGH AT LEAST
18Z THURSDAY FOR THE FORECAST AREA. AFTER 18Z...MODELS CONTINUE TO
BACK OFF ON THE AMOUNT OF PRECIPITATION...PRIMARILY BECAUSE THIS
POTENT SHORTWAVE TROUGH IS MOISTURE STARVED. ALL THE BETTER MOISTURE
IS TIED UP WITH A SOUTHERN STREAM-TYPE SHORTWAVE AND SURFACE LOW
PRESSURE SYSTEM OVER THE SOUTHERN PLAINS. THERE STILL IS SOME LIGHT
SNOW INDICATED OVER THE AREA PER THE 27.12Z ECMWF...BUT THE 27.12Z
GFS IS DRY. THEREFORE...HAVE LOWERED CHANCES ABOUT 10 PERCENT. IF
TRENDS CONTINUE...LIKELY THURSDAY WILL END UP DRY WITH JUST SOME
INCREASING MID AND HIGH CLOUDS. DUE TO THE DEEPER WEDNESDAY
SHORTWAVE TROUGH...HAVE LOWERED LOWS A FEW DEGREES WEDNESDAY NIGHT
TO ACCOUNT FOR MORE CANADIAN AIR ADVECTING IN. 925MB TEMPS ACTUALLY
FALL TO AROUND -20C BY 12Z THURSDAY. WIND CHILLS LOOK TO STAY OUT OF
ADVISORY CRITERIA THIS TIME...THOUGH. WITH MORE CANADIAN AIR IN
PLACE ON THURSDAY...ENDING UP ALSO COOLING THURSDAY JUST
SLIGHTLY...BUT HAVING BARE GROUND AND A LITTLE MORE SUN WILL HELP
COUNTERACT THE COLDER 850MB TEMPS.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
300 PM CST MON JAN 21 2013
21.12Z ECMWF/CANADIAN/GFS AND ECMWF ENSEMBLES STILL IN PRETTY GOOD
AGREEMENT FOR THE LONG TERM FORECAST AND SHOW A SIMILAR SOLUTION TO
YESTERDAY. THERE ARE TWO MAIN DIFFERENCES:
1. THE THURSDAY NIGHT DEAL WITH RESPECT TO PRECIPITATION IS NOW
LOOKING A LOT LESS THAN WHAT THE 20.12Z ECMWF HAD...SINCE WE ARE
ONLY INFLUENCED BY THAT POTENT SHORTWAVE DROPPING THROUGH THE AREA
FRIDAY MORNING. ALL OF THE MOISTURE AGAIN IS TIED UP WITH THE
SOUTHERN STREAM SYSTEM...SO AT MOST WE END UP WITH A FEW HUNDREDTHS
OF LIQUID EQUIVALENT. GIVEN THE POTENT NATURE OF THE TROUGH...
DEFINITELY MAINTAINED SOME 30-40 PERCENT CHANCES OF PRECIPITATION
FOR THURSDAY NIGHT. FUTURE FORECASTS MAY HAVE TO RAISE THESE SINCE
IT IS LOOKING LIKE MOST LOCATIONS SHOULD BE ABLE TO GET A
HUNDREDTH. ALSO ADDED SOME LOW CHANCES OF PRECIPITATION TO FRIDAY
BEING UNDER THE SHORTWAVE TROUGH TO ALLOW FOR A MORE CONVECTIVE
SITUATION.
2. UPPER RIDGING IS STILL PROGGED TO BUILD TOWARDS THE AREA FOR THE
WEEKEND...BRINGING TEMPERATURES BACK UP TO NEAR AND EVEN ABOVE
NORMAL FOR SUNDAY. HOWEVER...NOW THERE ARE INDICATIONS OF A
SHORTWAVE TROUGH MOVING THROUGH THIS RIDGING...IMPACTING THE AREA ON
SUNDAY. FOLLOWED THE CONSENSUS AND ADDED 20 PERCENT CHANCES OF SNOW
TO THE FORECAST. THIS TROUGH ALSO HOLDS BACK SOME OF THE WARMING
THAT WOULD HAVE OCCURRED UNDER THE LOW LEVEL SOUTHWEST FLOW.
HEADING INTO MONDAY...MORE TROUGHING IS SUGGESTED ALONG THE WEST
COAST OF THE U.S....BUT UNCERTAINTY EXISTS ON WHETHER IT SPLITS INTO
TWO AS SHOWN BY THE 21.12Z ECMWF OR STAYS TOGETHER PER 21.12Z GFS.
21.12Z ECMWF ENSEMBLE MEAN SEEMS TO SUGGEST BOTH SCENARIOS ARE
PLAUSIBLE. EITHER SCENARIO AT LEAST FOR MONDAY DOES NOT RESULT IN
ANY PRECIPITATION FOR US...WITH WARMING COMING BACK INTO THE AREA IN
THE WAKE OF THE SUNDAY SHORTWAVE TROUGH. READINGS LOOK LIKE THEY
SHOULD GET BACK ABOVE FREEZING FOR HIGHS.
&&
.AVIATION...TONIGHT AND TUESDAY
525 PM CST MON JAN 21 2013
WEST TO NORTHWEST WINDS WILL CONTINUE AT THE TAF SITES THROUGH THE
PERIOD. CLOUD FORECAST RATHER CHALLENGING AS ALL THE MODELS HOLD
ON TO A RIBBON OF MOISTURE BETWEEN 015-025K FEET THROUGH THE
PERIOD. SATELLITE/SURFACE OBSERVATIONS SHOWING MAINLY SCATTERED
CONDITIONS...WITH SOME BROKEN CEILINGS AT TIMES. FEEL PREVAILING
CONDITIONS WILL BE SCATTERED CLOUDS...WITH BRIEF PERIODS OF BROKEN
MVFR CEILINGS. CERTAINLY CANNOT RULE OUT SOME FLURRIES FROM TIME TO TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 PM CST MON JAN 21 2013
WI...WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR MNZ079-086>088-
094>096.
IA...WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
250 PM CST SUN JAN 20 2013
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
250 PM CST SUN JAN 20 2013
MAIN FORECAST CONCERNS ARE ON TEMPERATURES/WIND CHILLS THROUGH
TUESDAY AND ANY POTENTIAL LIGHT PRECIPITATION THROUGHOUT THE SHORT
TERM.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE U.S. WEST COAST INTO WESTERN BRITISH
COLUMBIA...WHILE DEEP TROUGHING ENCOMPASSED THE EASTERN TWO-THIRDS
OF CANADA INTO THE UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES
REGIONS. 500MB HEIGHTS AS WELL AS 850MB TEMPS WERE 1-1.5 STANDARD
DEVIATIONS BELOW NORMAL OVER THE FORECAST AREA. REGARDING THE 850MB
TEMPS...RAP ANALYSIS SHOWED READINGS OF -16 TO -20C OVER THE
FORECAST AREA. WITHIN THE DEEP TROUGHING...A SHORTWAVE WAS EVIDENT
FROM EASTERN SOUTH DAKOTA INTO NORTHERN IOWA. DPVA ASSOCIATED WITH
THE SHORTWAVE...MID-LEVEL MOISTURE SEEN ON THE 12Z ABR SOUNDING...AS
WELL AS LOW TO MID LEVEL FRONTOGENESIS WAS SUPPORTING AN AREA OF
LIGHT SNOW JUST SOUTH OF THE SHORTWAVE ACROSS WESTERN AND CENTRAL
IOWA. ONLY SOME SCATTERED ALTOSTRATUS HAS OVERSPREAD THE FORECAST
AREA ASSOCIATED WITH THE SHORTWAVE. SUNSHINE THROUGH THESE CLOUDS
AND THE COLD 850MB TEMPS HAS ONLY ALLOWED TEMPERATURES TO CLIMB INTO
THE LOWER TO MID TEENS. ON THE WEST SIDE OF THE DEEP TROUGH...A
120-140 KT JET AT THE TROPOPAUSE WAS DROPPING DOWN THROUGH EASTERN
ALBERTA AND SASKATCHEWAN. THE STRENGTH OF THIS JET IS PARTLY DUE TO
ANOTHER SURGE OF ARCTIC AIR...WITH THE RAP SHOWING 850MB TEMPS OF
-25 TO -30C FROM NORTH DAKOTA INTO MANITOBA. THIS COLD AIR WAS ALSO
SITTING RIGHT BEHIND A COLD FRONT STRETCHING FROM NEAR ABERDEEN
SOUTH DAKOTA INTO THE MN ARROWHEAD.
TONIGHT AND MONDAY...THE 120-140 KT JET STREAK OVER EASTERN ALBERTA
INTO SASKATCHEWAN IS PROGGED TO DIG INTO THE DAKOTAS TONIGHT AND INTO
IOWA ON MONDAY. THE FORECAST AREA ENDS UP IN THE LEFT EXIT REGION OF
THIS JET MONDAY MORNING...WHILE THE TROPOPAUSE DROPS TO AROUND
375MB. THESE STRENGTHENING UPPER DYNAMICS WILL END UP TIGHTENING THE
SURFACE PRESSURE GRADIENT OVER THE FORECAST AREA TONIGHT...HELPING
TO BRING IN THAT VERY COLD 850MB AIR ACROSS NORTH DAKOTA. NOT
ANTICIPATING ANY PRECIPITATION FROM THE DYNAMICAL FORCING...
PRIMARILY BECAUSE THERE IS TOO MUCH MID-LEVEL DRY AIR ACCOMPANYING
THE COLD ADVECTION AS SHOWN ON FORECAST SOUNDINGS. IN ADDITION...
THERE ARE CLEAR SKIES CURRENTLY PRESENT OVER NORTHWEST NORTH DAKOTA
AND SOUTH CENTRAL CANADA IN THE LEFT EXIT REGION. ONLY PRECIPITATION
THAT MAY OCCUR WOULD BE LIMITED TO FLURRIES...ASSOCIATED WITH THE
LOW CLOUDS AHEAD OF THAT COLD FRONT DROPPING SOUTHEAST OUT OF
NORTHERN SOUTH DAKOTA INTO THE MN ARROWHEAD. ADDITIONAL FLURRIES
COULD OCCUR ON MONDAY NORTH OF I-94...ASSOCIATED WITH LOW TO MID
LEVEL MOISTURE MOVING THROUGH WHICH IS CURRENTLY IN NORTHERN
MANITOBA. REGARDING TEMPERATURES...THEY ARE TRICKY GIVEN THE LACK OF
SNOW COVER AND THE INCREASING WINDS PROMOTING MIXING. WE DEFINITELY
ARE NOT GOING TO GET AS COLD AS THE DAKOTAS AND NORTHERN MN WHERE
SNOW EXISTS. STILL...ADVECTION ALONE AND CLEARING SKIES...COMBINED
WITH THE FACT THAT THE INCOMING 850MB TEMPS ARE 2-2.5 STANDARD
DEVIATIONS BELOW NORMAL...SHOULD ALLOW TEMPERATURES IN MOST
LOCATIONS TO DROP BELOW ZERO. SOME LOCATIONS OVER NORTH CENTRAL
WISCONSIN AND SOUTHEAST MN COULD EVEN DROP TO 10 BELOW ZERO OR SO.
TEMPERATURES WILL STRUGGLE TO RECOVER ON MONDAY BEING UNDER THE
850MB THERMAL TROUGH...BUT SUN AND BARE GROUND SHOULD GET HIGHS TO
NEAR OR SLIGHTLY ABOVE ZERO PER THE ECMWF. THE ECMWF HAS DONE WELL
HANDLING HIGH TEMPERATURES WITH THE BARE GROUND AND THUS WAS THE
PREFERRED GUIDANCE. WIND CHILLS WILL SOLIDLY END UP IN THE WIND
CHILL ADVISORY RANGE FROM LATE TONIGHT INTO MUCH OF MONDAY... AND
MAY EVEN APPROACH WARNING MONDAY MORNING OVER PORTIONS OF SOUTHEAST
MN. CONFIDENCE IS STILL NOT HIGH ENOUGH TO GO WITH THE WARNING GIVEN
UNCERTAINTY ON LOW TEMPERATURES.
MONDAY NIGHT AND TUESDAY...THE DEEP UPPER TROUGH IS PROGGED TO SHIFT
SLIGHTLY EASTWARD DURING THIS PERIOD AS THE RIDGE ALONG THE U.S.
WEST COAST GETS A PUSH EAST. IN RESPONSE...THE ARCTIC HIGH PRESSURE
AREA CURRENTLY SITTING UP IN ALBERTA IS ALLOWED TO BUILD INTO THE
FORECAST AREA. MODELS ARE IN GOOD AGREEMENT OF THE HIGH PRESSURE
AREA ENCOMPASSING THE AREA AT 00Z WEDNESDAY. UNTIL THE HIGH BUILDS
IN...A SLOWLY WEAKENING PRESSURE GRADIENT WILL EXIST...MAINTAINING A
NORTHWESTERLY BREEZE AND KEEPING WIND CHILLS DOWN. THUS...HAVING THE
WIND CHILL ADVISORY GO TO 18Z TUESDAY STILL LOOKS GOOD. SKIES SHOULD
END UP CLEAR IN MOST AREAS BY 12Z TUESDAY...FAVORING GOOD
RADIATIONAL COOLING. AGAIN...THE LACK OF SNOW COVER AND BREEZE WILL
ACT AGAINST GETTING TOO COLD. GIVEN THE COLDER MONDAY COMPARED TO
TODAY...SHOULD SEE LOWS AT LEAST A FEW DEGREES COLDER...ESPECIALLY
OVER THE SNOWPACK NORTH OF HIGHWAY 10. 850MB AND 925MB TEMPERATURES
ARE PROGGED TO ONLY SLOWLY RECOVER...CLIMBING TO -18 TO -22C AND -16
TO -22C RESPECTIVELY BY 00Z. DESPITE PLENTY OF SUNSHINE MINUS SOME
INCREASING HIGH CLOUDS IN THE AFTERNOON...ONLY ANTICIPATING HIGHS 5
TO 10 DEGREES WARMER PER ECMWF.
TUESDAY NIGHT AND WEDNESDAY...MODELS PROG A POTENT SHORTWAVE TO DROP
SOUTH OUT OF NORTHERN MANITOBA LATE TUESDAY AND HAVE IT CROSS LAKE
SUPERIOR LATE WEDNESDAY. MEANWHILE...THE WESTERN UPPER RIDGE BREAKS
DOWN AND FLATTENS WHILE SPREADING EAST...IN RESPONSE TO A POTENT
SHORTWAVE TROUGH CROSSING THE PACIFIC NORTHWEST. THE RESULT OF ALL
THIS IS TO STRENGTHEN THE UPPER JET CORE AT THE TROPOPAUSE OVER OR
JUST NORTH OF THE FORECAST AREA...TOWARDS 150-170 KT. WITH THE
STRENGTHENING UPPER JET COMES AN ISENTROPIC LIFT AND LOW TO MID
LEVEL FRONTOGENESIS ZONE ON ITS SOUTHWEST SIDE. THIS RESULTS IN
INCREASING AND THICKENING MID AND HIGH CLOUDS OVER THE FORECAST
AREA. FORCING IS NOT ALL THAT STRONG PER MODEL DERIVED OMEGA
FIELDS...BUT THE LOW LEVELS DO SLOWLY SATURATE OVER TIME. THUS...
THINK FLURRIES AT A MINIMUM WILL OCCUR. 20.12Z NAM ACTUALLY PRODUCES
SOME LIGHT QPF...ALBEIT IS THE MOST DYNAMIC BY EVEN HAVING A SURFACE
LOW DROPPING THROUGH IOWA. FOR NOW JUST WENT WITH ADDING
FLURRIES...BUT SOME CHANCES OF PRECIPITATION MAY NEED TO BE ADDED IF
MODELS TREND TOWARDS THE NAM. WITH THE THICKENING CLOUD COVER
AND BARE GROUND...TEMPERATURES SHOULD NOT FALL ALL THAT MUCH TUESDAY
NIGHT. 925MB TEMPS WARM FURTHER ON WEDNESDAY WITH THE UPPER FLOW
TURNING MORE WEST-NORTHWESTERLY...CLIMBING TO -8C SOUTHWEST TO -16C
NORTHEAST BY 00Z. THUS...DESPITE CLOUD COVER...TEMPERATURES SHOULD
BE ABLE TO CLIMB INTO THE MID TEENS TO MID 20S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
250 PM CST SUN JAN 20 2013
VERY GOOD AGREEMENT EXISTS ON THE LONG TERM PATTERN FROM THE 20.12Z
ECMWF/GFS/CANADIAN AND ECMWF ENSEMBLES. THE SHORTWAVE TROUGH OVER
THE PACIFIC NORTHWEST TO START THE PERIOD DIGS INTO NEBRASKA AND
IOWA FOR THURSDAY. AN INVERTED TROUGH ACCOMPANIES THE SHORTWAVE...
WITH A COMBINATION OF MID-LEVEL FRONTOGENESIS...DPVA AND MOISTURE
EXPECTING TO BRING SOME SNOW ACROSS THE FORECAST AREA. HOWEVER...
THIS HAS BEEN A POINT OF CONTENTION FOR A FEW DAYS...WITH MODELS
VARYING ON HOW MUCH QPF WITH EVEN A FEW SUGGESTING DRY EITHER ON
THURSDAY AND/OR THURSDAY NIGHT. AS SUCH...HAVE KEPT A CONSENSUS
AROUND 30 PERCENT CHANCE FOR BOTH THURSDAY AND THURSDAY NIGHT.
CERTAINLY IF THE TREND IN THE 20.12Z ECMWF CONTINUES...WE WILL NEED
HIGHER CHANCES AS IT NOW SUGGESTS UPWARDS OF 2-3 INCHES OF SNOW.
THIS IS QUITE A BIT DIFFERENT FROM ITS PREVIOUS RUN...THOUGH.
ANOTHER SURGE OF CANADIAN AIR WITH HIGH PRESSURE IS STILL FORECAST
TO DROP INTO THE FORECAST AREA IN THE WAKE OF THIS SYSTEM FOR FRIDAY
AND FRIDAY NIGHT. HOWEVER...THE 850MB TEMPS ARE NOT NEARLY AS COLD
AS THE CURRENT ARCTIC AIR SURGE...ONLY PROGGED TO DIP DOWN TO -20C
AT MOST.
FOR THE WEEKEND...A DEEP TROUGH IS FORECAST TO FORM JUST OFF OR ON
THE WEST COAST OF THE U.S....SETTING UP A PATTERN CHANGE AS 500MB
HEIGHTS RISE DOWNSTREAM ACROSS THE REST OF THE U.S.. EVENTUALLY A
LOW PRESSURE SYSTEM FORMS IN THE VICINITY OF WYOMING AND COLORADO BY
LATE SUNDAY...BUT MOISTURE RETURN TOWARDS THE FORECAST AREA IS STILL
LIMITED. THUS...A DRY WEEKEND WITH WARMING TEMPERATURES IS IN STORE.
HOW WARM WILL DEPEND ON HOW MUCH SNOW OCCURS WITH THE THURSDAY
SYSTEM. FOLLOWED THE CONSENSUS FOR HIGH TEMPERATURES FOR THE
WEEKEND...BUT THESE MAY STILL BE TOO COOL GIVEN 925MB TEMPS
CLIMBING TO 0 TO -4C BY 18Z SUNDAY PER 20.12Z GFS/ECMWF.
&&
.AVIATION...THIS AFTERNOON THROUGH MONDAY
1131 AM CST SUN JAN 20 2013
WEAK SHORTWAVE AND FORCING/LIFT WERE PASSING SOUTH/WEST OF THE AREA
LATE THIS MORNING...WITH DRIER LOW/MID LEVEL AIR HOLDING OVER THE
TAF SITES. AFTERNOON LOOKING FLURRY-FREE WITH SCT TO LCL BKN CLOUDS
AROUND 10K FT.
AREA OF LOWER BKN-OVC POST-TROUGH CLOUDS OVER NORTHERN MN TO SLIDE
SOUTHEAST ACROSS THE TAF SITES VERY LATE THIS AFTERNOON AND THIS
EVENING. CIGS LOOKING MOSTLY TO BE IN THE 4K-6K FT RANGE WITH SCT
FLURRIES. ONLY CARRIED VCSH IN TAFS AS THIS CLOUD BAND PASSES.
UPSTREAM OF THIS GENERALLY CLEAR SKIES OVER ND/NORTHWEST MN AND THIS
AIRMASS TO BE OVER THE TAF SITES LATER TONIGHT/MON. GOOD VFR
CONDITIONS LATER TONIGHT/WED BUT SFC PRESSURE GRADIENT TIGHTENS UP
OVER THE AREA FOR TONIGHT/MON. NORTHWEST WINDS BY LATER TONIGHT AND
FOR MON LOOKING TO BE IN THE 12-18KT RANGE WITH GUSTS 20-25KTS. THIS
WILL PRODUCE WIND CHILLS OF 20 BELOW TO 30 BELOW AT THE TAF SITES FOR
LATER TONIGHT/MON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST SUN JAN 20 2013
WI...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY
FOR WIZ017-029-032>034-041>044-053>055-061.
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY
FOR MNZ079-086>088-094>096.
IA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
236 PM CST SUN JAN 20 2013
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE BUILDING SOUTHEAST ACROSS THE NORTHERN AND CENTRAL PLAINS
BENEATH NORTHWEST FLOW ALOFT. EMBEDDED SHORTWAVE TROUGH WITHIN THIS
NW FLOW IS MOVING OVER WESTERN LAKE SUPERIOR EARLY THIS AFTERNOON AND
IS HELPING TO PRODUCE SNOW SHOWERS AND FLURRIES OVER NORTHERN
MINNESOTA WHICH ARE PUSHING INTO NORTHWEST WISCONSIN. THE NEXT PUSH
OF BITTERLY COLD ARCTIC AIR EXISTS BEHIND THIS SHORTWAVE WHERE
TEMPERATURES REMAIN BELOW 0F. FORECAST CONCERNS INCLUDE SMALL
PRECIP CHANCES THIS EVENING...THEN TEMPERATURES AND ASSOCIATED
HEADLINES.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE ACROSS THE UPPER PENINSULA
OVER THE REST OF THE AFTERNOON AND EARLY THIS EVENING. TAIL OF THE
VORT MAX WILL PUSH AN AREA OF CLOUDS AND FLURRIES ACROSS THE AREA
LATE THIS AFTERNOON AND THIS EVENING. HAVE ADDED THE CHANCE OF
FLURRIES TO THE FORECAST. LOW LEVEL WINDS LOOK TOO WESTERLY FOR
LAKE EFFECT SNOW TO BE MUCH OF AN ISSUE FOR VILAS COUNTY. BUT WITH
ENHANCEMENT FROM THE SHORTWAVE THIS EVENING...WILL KEEP A CHANCE OF
SNOW SHOWERS OVER VILAS AND ACCUMS LESS THAN A HALF INCH. TIMING
THE DEPARTURE OF THE CLOUDS IS DIFFICULT SINCE RH IN THE 900-800MB
LAYER REMAINS FAIRLY HIGH. SATELLITE IMAGERY SHOWS CLEARING TAKING
PLACE OVER NORTHERN MINNESOTA AND ONTARIO...SO THINK SKIES WILL AT
LEAST PARTIALLY CLEAR FROM WEST TO EAST AFTER MIDNIGHT TONIGHT.
TEMPERATURES WERE FIRMLY IN THE TEENS BELOW ZERO OVER NORTHERN
MINNESOTA THIS MORNING. WILL HAVE COMPARATIVELY MORE WIND THAN
FARTHER WEST...BUT STILL THINK WILL REACH IN THE LOW TEENS BELOW
ZERO OVER NORTH-CENTRAL WISCONSIN. WITH NW WINDS 7-12 KTS
TONIGHT...WIND CHILL READINGS WILL APPROACH 20 BELOW OVER
NORTH-CENTRAL WISCONSIN AROUND 06Z...AND OVER THE FOX VALLEY BY
10Z. WILL BEGIN THE NEW WIND CHILL HEADLINES AT THOSE TIMES.
MONDAY...NORTHWEST WINDS WILL CONTINUE TO POUR BITTERLY COLD ARCTIC
AIR ACROSS THE REGION...DROPPING 850MB TEMPS TO 28-29C BELOW ZERO.
ANOTHER WEAK SHORTWAVE WILL BE SWINGING ACROSS THE STATE. SOME
FLURRIES OR LIGHT SNOW NORTH OF LAKE WINNIPEG WITH THIS FEATURE AND
WILL ADD TO THE FORECAST OVER NORTH-CENTRAL AND CENTRAL WISCONSIN.
NW WINDS WILL REMAIN BREEZY...AND TEMPS WILL STRUGGLE TO REACH ABOVE
0F. WIND CHILL READINGS MAY BRIEFLY RISE ABOVE ADVISORY CRITERIA
FOR A FEW HOURS DURING THE AFTERNOON OVER THE FOX VALLEY AND
ADJACENT TO GREEN BAY. BUT HEADLINES WILL HAVE TO BE ISSUED AGAIN
BY 23-24Z...SO WILL JUST RUN HEADLINES THROUGH MONDAY NIGHT. HIGHS
RANGING FROM 6 BELOW OVER N-C WISCONSIN...TO ABOUT 6 ABOVE NEAR LAKE
MICHIGAN.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. COLD ARCTIC AIR
INTRUSION WILL CONTINUE TO GRAB THE HEADLINES FOR THE FIRST HALF
OF THE WEEK. AN ONGOING WIND CHILL ADVISORY EXPECTED OVER WESTERN
AREAS TROUGH TUESDAY NOON. THE REST OF THE FORECAST AREA INCLUDING
THE LAKESHORE REGION WILL BE ADDED STARTING MONDAY EVENING AND
LASTING THROUGH NOON AS WELL AS THE CORE OF THE COLDEST AIR
FILTERS OVER THE AREA. MATTER OF FACT...LATER SHIFTS MAY POSSIBLY
NEED TO UPGRADE TO A WIND CHILL WARNING OVER PORTIONS OF NORTHERN
AND PARTS OF CENTRAL WISCONSIN MONDAY NIGHT. RESURGENT COLD AIR
AND NORTHWEST WINDS WILL CONTINUE LAKE EFFECT SNOW SHOWERS FAR
NORTH BUT DRY AIR MASS AND LOW INVERSIONS WILL LIKELY LIMIT PLUME
DEVELOPMENT.
WINDS WILL BE ON THE DECREASE LATER TUESDAY INTO WEDNESDAY AS A
COLD HIGH PRESSURE SYSTEM SETTLES OVER THE AREA. LAKE EFFECT SNOW
SHOWERS END AS WINDS TURN MORE SOUTHWEST...BUT ANOTHER COLD NIGHT
EXPECTED WITH THE LIGHTER WINDS UNDER THE HIGH PRESSURE SYSTEM.
MIN TEMPERATURES WILL BE IMPACTED BY CLOUDS THROUGH WEDNESDAY...BUT
GUIDANCE TENDS TO OVERDUE THE CLOUDS AT TIMES DUE TO THE RELATIVE
EASE TO SATURATE A COLD DRY AIR MASS. WITH SUCH A COLD AIR MASS
DROPPING IN FOR THE FIRST HALF OF THE WEEK...YOU WONDER HOW COLD
IT COULD HAVE BEEN WITH A FRESH DEEP SNOW COVER. WITH THE LIMITED
SNOW COVER...THE ARCTIC AIR WILL DRIVE AREA FROST DEPTHS DEEPER
THIS WEEK.
WEAK WAA STARTS ON WEDNESDAY AS A SHORT WAVE TROUGH DROPS INTO THE
NORTHERN GREAT LAKES REGION. MORE WIDESPREAD CLOUDS IN THE
BAROCLINIC ZONE FROM MT TO THE OHIO VALLEY TODAY MAY EDGE NORTH
INTO PARTS OF CENTRAL WISCONSIN WEDNESDAY AND CONTINUE TO SPREAD
NORTH THROUGH THURSDAY. LIGHT SNOW REMAINS IN THE FORECAST LATER
IN THE WEEK AS A CLIPPER SYSTEM DROPS INTO THE REGION AND PHASES
WITH SOME SOUTHERN STREAM ENERGY SOUTH AND EAST OF THE AREA. LAKE
EFFECT POTENTIAL INCREASES AGAIN THURSDAY NIGHT AND FRIDAY AS CAA
WITH NORTHWEST WINDS DEVELOP IN THE WAKE OF THE CLIPPER SYSTEM.
ANY LAKE EFFECT SNOW WILL END FRIDAY NIGHT AS A MODERATING
TEMPERATURE PATTERN STARTS WITH A RETURN TO A ZONAL FLOW WITH WAA
FOR THE WEEKEND.
&&
.AVIATION...THE STRONG WINDS THAT DEVELOPED IN THE WAKE OF THE
ARCTIC COLD FRONT HAVE SUBSIDED. LAKE EFFECT SNOW SHOWERS AND
ASSOCIATED MVFR/IFR CONDITIONS CAN BE EXPECTED ACROSS FAR NC WI
(ESPECIALLY VILAS COUNTY) THROUGH TONIGHT. MOST OF THE REMAINING
FORECAST AREA SHOULD HAVE VFR CONDITIONS...ALTHOUGH FLURRIES AND
PATCHY MVFR CIGS ARE POSSIBLE TONIGHT...AS AN UPPER LEVEL TROF AND
REINFORCING SHOT OF ARCTIC AIR ARRIVES.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 4 AM MONDAY TO NOON CST TUESDAY FOR
WIZ013-020-021-031-037>039-045-048-049-073-074.
WIND CHILL ADVISORY FROM 6 PM MONDAY TO NOON CST TUESDAY FOR
WIZ022-040-050.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY
FOR WIZ005-010>012-018-019-030-035-036.
&&
$$
MPC/TDH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1034 PM CST SAT JAN 19 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE AND ADD NEW UPDATE
SECTION
.UPDATE...ANTICIPATE BEING ABLE TO ALLOW THE WIND ADVISORY FOR
CENTRAL WI TO EXPIRE AS SCHEDULED AT MIDNIGHT. STILL WINDY
THERE...BUT IT SEEMS TO HAVE PEAKED AND WINDS WERE STARTING TO
SLOWLY DECR.
.PREV DISCUSSION...ISSUED AT 757 PM CST SAT JAN 19 2013...
UPDATE...GOING TO REPLACE THE WIND CHILL ADVISORY FOR VILAS
COUNTY WITH A WINTER WX ADVISORY AS A CATCH ALL FOR THE
SNOW...WIND...AND LOW WIND CHILLS LATER TONIGHT. VSBYS STILL LOW
BACK TO THE NW OF THERE AT IWD/ASX...AND TRAJ BECOMING MORE
FAVORABLE FOR ADDITIONAL LAKE-EFFECT. SUBSIDENCE/DRIER AIR
ARRIVING OVER THE LAKE WL EVENTUALLY SHUT THINGS DOWN. BUT GIVEN
THE SNOW THATS ALREADY FALLEN...THE WIND TO BLOW IT AROUND...AND
THE PLUMMETING TEMPS LIKELY RESULTING IN ICY ROADWAYS...IT SEEMS
THE MAIN HAZARD THE REST OF THE NGT WL BE MORE SN/BLSN RELATED
RATHER THAN WIND CHILL RELATED.
THE REST OF THE N WL HAVE TRAVEL PROBLEMS TOO...BUT ADDITIONAL
SNOWFALL WL BE MUCH LIGHTER AS LAKE-EFFECT WON/T BE A MAJOR FACTOR
AS IN VILAS.
THE OTHER HEADLINES SEEM TO BE ON TRACK...SO AT THIS POINT DON/T
PLAN ON MAKING ANY CHGS UNTIL WE GET CLOSER TO THE SCHEDULED
EXPIRATION OF THE WIND ADVSIORY OVER THE WRN PART OF THE AREA LATE
THIS EVENING.
SKOWRONSKI
DISCUSSION...ISSUED AT 600 PM CST SAT JAN 19 2013...
UPDATE...SPOTTER REPORT FROM ONEIDA COUNTY INDICATING VERY POOR
TRAVEL CONDITIONS. VSBY DOWN TO NEAR ZERO IN SN/BLSN. PLUS...TEMPS
PLUNGING BLO FZG WL LIKELY CAUSE ROADS TO ICE OVER AS WELL. THE
LOW VSBYS SHOULD BE RELATIVELY BRIEF...BUT THEIR SUDDEN ONSET WL
PROBABLY STILL CAUSE SIG PROBLEMS FOR ANYONE OUT ON THE ROADS.
SENT UPDATED SPS TO HIGHLIGHT THE SITN.
STILL NOT CERTAIN JUST HOW FAR S AND E THE POOR CONDITIONS WL
REACH. RADAR SHOWS A DEFINITE INCR IN SHSN ACTIVITY OVER CENTRAL
AND INTO E-C WI. BUT WE WERE WARM ENOUGH HERE AT THE OFFICE TO GET
SOME RAIN AS THE PCPN TYPE. ALTHOUGH CONDITIONS PROBABLY WON/T GET
QUITE AS BAD AS IN THE NW PART OF THE FCST AREA BECAUSE THE TEMP
DROP TO BLO FZG WL LAG A LITTLE FARTHER BEHIND THE PCPN...COULD
STILL GET SOME NASTY TRAVEL CONDITIONS AT TIMES.
UPDATED PRODUCT SUITE ALREADY SENT...THOUGH PREV FCST ALREADY HAD
THE GIST OF THE SITN PRETTY WELL SPELLED OUT.
SKOWRONSKI
DISCUSSION ISSUED AT 443 PM CST SAT JAN 19 2013...
SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG
SHORTWAVE DIVING SE OVER NORTHERN MINNESOTA...WHICH IS DRIVING A
SURFACE LOW OVER WESTERN LAKE SUPERIOR. ARCTIC COLD FRONT EXTENDS
WESTWARD FROM THIS LOW OVER CENTRAL MINNESOTA AND NORTHERN SOUTH
DAKOTA. RETURNS ON RADAR OVER WESTERN WISCONSIN MAY NOT BE HITTING
THE GROUND...BUT THERE IS SCATTERED SNOW SHOWERS OCCURRING ALONG THE
ARCTIC FRONT AND JUST AHEAD OF THE SHORTWAVE...WHICH ARE DROPPING
VISIBILITIES TO AROUND A MILE AT TIMES. WINDS ARE ALSO RAPIDLY
INCREASING BEHIND THE FRONT...WITH SOME WIDELY SCATTERED REPORTS
JUST HIGHER THAN 40 KTS. TEMPERATURES BEHIND THE FRONT ARE FALLING
QUICKLY INTO THE SINGLE DIGITS ABOVE ZERO...WHILE READINGS ARE IN
THE UPPER 30S TO LOWER 40S ACROSS NORTHERN WISCONSIN. WITH THE
PASSAGE OF THE ARCTIC FRONT THIS EVENING...TEMPERATURE AND WIND
HEADLINES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE STRONG SHORTWAVE WILL PUSH THE ARCTIC COLD FRONT
RAPIDLY SOUTHEAST ACROSS NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON...AND NORTHEAST WISCONSIN EARLY THIS EVENING. DESPITE
STRONG MID AND UPPER LEVEL FORCING IN THE FORM OF -DIVQ AND
DIVERGENCE AHEAD OF THE WAVE...MID-LEVELS STRUGGLE TO SATURATE. SO
THINK WILL SEE NOT MUCH MORE THAN A SCT LINE OF SNOW SHOWERS JUST
AHEAD OF THE SHORTWAVE...WHICH WILL PROVIDE A BRIEF BURST OF SNOW
AND REDUCE VISIBILITIES...BUT NOT MUCH IN THE WAY OF ACCUMS. SO
WILL KEEP POPS IN THE LOW CHANCE RANGE OVER NE WISCONSIN FOR EARLY
THIS EVENING WITH THE FRONTAL PASSAGE. CLOUDS EXTEND NORTH ACROSS
MINNESOTA TO THE CANADIAN BORDER WHERE SNOW SHOWERS CONTINUE TO FALL
UNDER A LOW OVERCAST. SO THINK SNOW SHOWERS WILL FALL OVER
NORTH-CENTRAL WISCONSIN FOR MUCH OF THE EVENING. BEHIND THE FRONT
BY LATE IN THE EVENING...LOW LEVEL WINDS WILL SHIFT TO THE NORTHWEST
WITH GOOD TRAJECTORIES FOR LAKE EFFECT SNOW ACCUMULATIONS.
HOWEVER...850MB TEMPS WILL BE PLUMMETING INTO THE LOWER 20S BELOW
ZERO WHICH IS GETTING TOO COLD FOR GOOD DENDRITIC SNOW GROWTH. AS A
RESULT...FLAKES WILL BE SMALL AND ACCUMS SHOULD BE HELD IN
CHECK...AND WILL CONTINUE TO GO WITH 1-3 INCH AMOUNTS TONIGHT IN THE
SNOW BELT OF N-C WISCONSIN. LITTLE TO NO ACCUM ELSEWHERE.
BIGGER IMPACTS WILL LIKELY BE WIND RELATED. STRONG DESCENT
IMMEDIATELY BEHIND THE FRONT IN A REGION OF STRONG COLD
ADVECTION...STEEPENING LOW LEVEL LAPSE RATES...AND GOOD ISALLABARIC
PUSH WILL CREATE STRONG GUSTY WEST TO NORTHWEST WINDS THAT SHOULD
APPROACH OR JUST EXCEED WIND ADVISORY CRITERIA LATE THIS AFTERNOON
AND THROUGH THE EVENING. STRONGEST WINDS IN THE MIXED LAYER OF
45-50KTS ARE PROGGED TO OCCUR OVER CENTRAL AND EAST-CENTRAL
WISCONSIN WHERE THE CURRENT WIND ADVISORY RESIDES...SO PLACEMENT OF
HEADLINES LOOK GOOD. THE GUSTY WINDS SEEM TO BE RUNNING AN HOUR OR
TWO LATE...AND WILL LIKELY HAVE TO WAIT UNTIL THE COLDER AIR ALOFT
ARRIVES TO STEEPEN THE LOW LEVEL LAPSE RATES FOR THE GUSTY WINDS TO
OCCUR...LIKELY IN THE 22-02Z TIME PERIOD. WILL KEEP HEADLINE TIMING
STATUS QUO. THE STRONG PRESSURE RISES SHIFT TO THE EAST BY
MIDNIGHT...AND WIND GUSTS SHOULD BE SUBSIDING BY THIS TIME. AS A
RESULT...STILL THINK THE EVENING OR MIDNIGHT CREW WILL BE ABLE TO
END WIND HEADLINES EARLY. THE COMBO OF GUSTY NW WINDS AND INCOMING
ARCTIC AIR WILL CREATE WIND CHILL READINGS OF 20-25 DEGREES BELOW
ZERO OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATE TONIGHT.
SUNDAY...ARCTIC AIR WILL CONTINUE TO POUR ACROSS THE REGION ON
SUNDAY. NORTHWEST WINDS WILL CONTINUE TO PRODUCE LAKE EFFECT SNOW
SHOWERS IN THE SNOW BELTS...BUT WINDS DO BACK A BIT SO SNOW SHOWERS
SHOULD BE GRADUALLY DIMINISHING OVER THE COURSE OF THE MORNING. AIR
WILL REMAIN TOO COLD FOR DENDRITIC SNOW GROWTH SO NOT EXPECTING MUCH
ACCUMS. OTHERWISE...STEEP LOW LEVEL LAPSE RATES AND FLOW OFF LAKE
SUPERIOR SHOULD KEEP SKIES PARTLY TO MOSTLY CLOUDY. TEMPS IN THE
SINGLE DIGITS TO LOWER TEENS.
LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. DURATION OF THE
ARCTIC BLAST OF AIR THIS WEEK ALONG WITH LIKELY ADDITIONAL WIND
CHILL HEADLINES WILL BE THE PRIMARY ISSUE FOR THE FIRST HALF OF
THE NEW WEEK. ANOTHER CLIPPER SYSTEM IS PROGGED TO DROP INTO THE
REGION AROUND THURSDAY FOLLOWED WITH A REINFORCING BUT MILDER
AND PERHAPS BRIEFER SHOT OF ARCTIC AIR. SOME MDM RANGE MODELS ARE
INDICATING A MODERATING TREND LATER NEXT WEEKEND.
ADDITIONAL WIND CHILL HEADLINES WILL LIKELY BE POSTED LATER THIS
WEEKEND AS THE SATURDAY NIGHT HEADLINES EXPIRE. FORECAST TEMPS
SUGGEST THE COLDEST AIR ARRIVES LATER MONDAY WITH SOME CURRENT
VALUES APPROACHING WIND CHILL WARNING CRITERIA MONDAY NIGHT.
TYPICAL WITH THE VERY COLD PATTERNS...MODELS LIKELY OVERDOING THE
COVERAGE OF CLOUDS. WILL TONE DOWN CLOUDS OVER MOST LOCATIONS
EXCEPT FOR AREAS JUST DOWNSTREAM FROM LAKE SUPERIOR.
LAKE EFFECT SNOWS EXPECTED OVER FAR NORTH CENTRAL WISCONSIN WITH
THE COLD AIR INTRUSION. BUT APPEARS TO BE LIMITED AT THIS TIME
DUE TO THE DRY AIR MASS...FALLING INVERSION HEIGHTS...AND A BIT
TOO WESTERLY WIND DIRECTION.
TEMPS TO MODERATE TO NEAR SEASONAL LEVELS LATER THIS WEEK WITH A
CLIPPER SYSTEM DROPPING SOUTH INTO THE NORTHERN AND CENTRAL PLAINS
THURSDAY BEFORE PHASING WITH SOME SOUTHERN STREAM ENERGY THURSDAY
NIGHT. GFS IS INDICATING A POSSIBLE ADVISORY SNOW OVER THE SOUTH
HALF OR THIRD OF THE STATE THURSDAY NIGHT WITH THIS PHASED SYSTEM.
WILL GLANCE AT THE ECMWF THIS AFTERNOON TOO SEE IF A SIMILAR
TREND IN ORDER TO MAKE ANY ADJUSTMENTS...BUT GOING FORECAST THAT
FAR OUT REASONABLE.
&&
.AVIATION...FOR 06Z TAF ISSUANCE. IMPROVING CONDITIONS
EXPECTED...EXCEPT IN THE SNOWBELT. THINK THE LOW CLDS WL ERODE
PRETTY QUICKLY LATER IN THE NGT ONCE DRY ARCTIC AIR BECOMES
ESTABLISHED ACRS THE AREA.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR WIZ038>040-048>050.
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ030-031-035>037-
045.
WIND CHILL ADVISORY UNTIL 9 AM CST SUNDAY FOR WIZ010-011-018-019-
030-035-036.
WIND ADVISORY UNTIL 6 AM CST SUNDAY FOR WIZ022.
WINTER WEATHER ADVISORY UNTIL 9 AM CST SUNDAY FOR WIZ005.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1240 AM EST TUE JAN 22 2013
.AVIATION...
LAKE EFFECT CONTINUES WITH A DOMINANT BAND FOCUSED OVER KSBN. RADAR
TRENDS SHOWS THIS BAND FAIRLY STATIONARY WITH RENEWED DEVELOPMENT
UPSTREAM. KEPT VIS BELOW 1SM THROUGH THE NIGHT WITH OCCASIONAL 1/4SM
AND HEAVY SNOW. THIS BAND MAY BEGIN TO SHIFT NORTH AFTER 12Z AS MEAN
FLOW BACKS JUST A FEW DEGREES. STILL EXPECT CONTINUED SNOW SHOWERS
WITH EXTREME INSTABILITY IN PLACE. VFR EXPECTED AT KFWA THOUGH
MODELS SUGGEST SOUTHERN FRINGE OF LAKE CLOUDS MAY EXTEND INTO
NORTHERN ALLEN COUNTY.
&&
.UPDATE...
MULTI BAND LK EFFECT CONTS UNABATED THIS EVENING IN RESPONSE TO
EXTREME LK INDUCED INSTABILITY. PRIMARY LIMITING FCTR TO ACCUMS
CONTS TO BE POOR MICROPHYSICAL THERMO ENVIRONMENT W/LL ASCENT
MAXIMUM CNTRD ARND -20C. THUS XPC FINE POWDER SMALL PLATE CRYSTAL
TYPE TO DOMINATE W/SUBSEQUENT ACCUMS SIGLY LIMITED. OTRWS HRRR/RUC
MODEL FCST TRENDS DOVETAIL IN NICELY W/OBSVD RADAR/SAT TRENDS THIS
EVENING W/GENERAL SLOW VEER AND SLOW SWD SUPPRESSION OF STRONGEST
INLAND PENETRATING CONVERGENT BAND. XPC UPTICK IN BAND EVOLUTION
OVERNIGHT W/BTR LK INDUCED SATURATION DVLPG WITHIN SHALLOW CLD
GROWTH LYR. IN FACT BASED ON RUC CROSS-SECTIONS DEEPENING UVM MAY
YIELD A PD OF LARGER SECTORED PLATE GROWTH TWD DAYBREAK TOMORROW.
HWVR AS IT STANDS NOW WILL LEAVE ADVISORY AREA AS IS BUT CONCEDE
SOME THREAT EXISTS SWD OF THE STATELINE ACRS ST. JOE...ELKHART AND
LAGRANGE TO GET IN ON SOME DECENT SNOW ACCUMULATION LT TONIGHT
THROUGH TUES. REGARDLESS PRIMARY OVERNIGHT GRID CHG SHIFTS HIGHEST
POPS ABT 20 MILES SWD OF AFTN FCST. REMAINDER OF NR TERM GRIDS
DEEMED ON TRACK AND LEFT UNCHGD.
PROLONGED PD OF IFR/LIFR CONDS AT KSBN W/ORGANIZING SNOWBANDS
OVERNIGHT...VFR AT KFWA.
&&
.SHORT TERM...THROUGH TUESDAY NIGHT.
LAKE EFFECT MACHINE HAS BEEN UNDERWAY ACROSS MUCH OF WESTERN LOWER
MICHIGAN INTO PORTIONS OF NORTHERN INDIANA TODAY. ONE BAND SET UP
FOR SEVERAL HOURS FROM BERRIEN INTO ST JOE COUNTIES IN MI BEFORE
UNDULATING ACROSS THE AREA. DESPITE OCCASIONAL RETURNS UPWARDS OF 30
DBZ THAT WOULD SUGGEST 1 TO 2 INCH PER HOUR OR MORE SNOW RATES
AMOUNTS THAT HAVE BEEN TRICKLING IN HAVE ONLY BEEN AN INCH OR LESS
WITH SOME ISOLATED HIGHER AMOUNTS. ROADS HAVE BEEN REPORTED SNOW
COVERED AND SLIPPERY ACROSS BERRIEN AND CASS COUNTIES WITH NO SIG
IMPACTS ACROSS THE REMAINDER OF THE LAKE EFFECT ADVISORY AREA.
HOWEVER...THE HEAVIER BANDS ARE STILL IMPACTING VSBYS...DOWN BELOW A
HALF MILE AT TIMES...WITH BLOWING SNOW. RADAR TRENDS SUGGEST A LULL
IN ACTIVITY MAY TRANSPIRE THIS EVENING AS WEAK SUBSIDENCE BEHIND THE
DEPARTING WAVE KEEPS BANDS RATHER DISORGANIZED. GIVEN IMPACTS
EXPECTED INTO THE EVENING AND LOWERING WIND CHILLS...WILL EXTEND
LAKE EFFECT SNOW ADVISORY FOR WESTERN 3 MI COUNTIES THROUGH 5 AM BUT
DROP BRANCH AND HILLSDALE. HI-RES MODELS INDICATE SNOW SHOWERS MAY
PICK UP ONCE AGAIN LATER THIS EVENING INTO THE OVERNIGHT HOURS AND
ESPECIALLY TUESDAY WITH ANOTHER SHOT OF MSTR AND INCREASED LIFT.
SFC-850 MB DELTA T`S REMAIN MORE THAN FAVORABLE WELL INTO THE 20S
BUT DGZ ONCE AGAIN WILL BE AT OR JUST ABOVE GROUND LEVEL...SETTING
UP A SIMILAR SCENARIO TO TODAY WITH LACK OF DENDRITIC GROWTH AND
RESULTANT LOW ACCUM POTENTIAL. SOME CHANGES MADE OVERNIGHT TO POPS
TO ALIGN BETTER WITH CURRENT MODEL OUTPUT BUT NO SIG CHANGES MADE TO
TUES/TUES NGT IN TERMS OF POPS/QPF/SNOWFALL.
IN TERMS OF TEMPS AND WIND CHILLS...TEMPS TODAY HAVE FLUCTUATED BY
SEVERAL DEGREES ACROSS THE AREA...WITH BRIEF RISES UNDER POCKETS OF
SUNSHINE FOLLOWED BY A QUICK DROP BACK WITH CLOUD COVER ARRIVAL.
UPSTREAM SIMILAR TRENDS ARE SEEN BUT MOST NOTABLE IS DECREASING
DEWPTS...WELL INTO THE NEGATIVE TEENS. THESE SHOULD HEAD TOWARDS THE
AREA TONIGHT. DESPITE LACK OF DECOUPLING TONIGHT OF WINDS...STRENGTH
OF CAA WILL STILL ALLOW FOR A DROP OFF IN TEMPS INTO THE 0 TO 5
DEGREE ABOVE RANGE. WOULD NOT BE SURPRISED TO SEE A SPOT OR 2 GO SUB
ZERO FOR A PERIOD. WIND CHILLS WILL STILL RANGE FROM -12 TO -18 IN
MANY AREAS EVEN CLOSER TO THE LAKE. AS A RESULT WIND CHILL ADVISORY
WILL CONTINUE WITH ONLY CHANGE BEING TO ADD BRANCH AND HILLSDALE
COUNTIES. ONLY MODEST INCREASE IN TEMPS EXPECTED ON TUESDAY WITH
HIGHS STRUGGLING INTO THE TEENS AND A QUICK DROP OFF BACK INTO THE
SINGLE DIGITS TUES NGT. WIND CHILLS COULD HEAD TOWARDS CRITERIA ONCE
AGAIN TUES NGT BUT WILL HOLD OFF ON ANY CHANGES/ADDITIONS TO THE
CURRENT HEADLINES.
&&
.LONG TERM.../WED-MON/
LONG WAVE TROF OVER ERN CANADA/U.S. WILL MAINTAIN NW FLOW ALOFT
ACROSS THE GRTLKS AT START OF THIS PERIOD. ARCTIC AIRMASS WILL
REMAIN IN PLACE WITH H85 TEMPS AROUND -20C WED MORNING. SHRTWV
ROTATING AROUND CLOSED LOW OVER SE CANADA WILL DROP SE INTO THE WRN
GRTLKS WED AND MAY PROVIDE SUFFICIENT FORCING TO CAUSE A FEW SNOW
SHOWERS BEYOND JUST LAKE EFFECT AREAS. AS THE SHRTWV MOVES SE ACROSS
THE GRTLKS WED NGT... WLY LOW LEVEL WINDS OVER SRN LM WILL VEER TO
NE. IN THE PROCESS A BRIEF LONG NLY FETCH MAY ENHANCE LAKE EFFECT
SNOW SHOWER ACTIVITY IN NW INDIANA... BUT PRBLY TOO SMALL A WINDOW
TO RESULT IN SGFNT ACCUMS...ESPECIALLY CONSIDERING WARMING ALOFT AND
LOWERING INVERSION OVERNIGHT.
CLOSED LOW OVER NERN PAC EXPECTED TO KICK OUT A SHRTWV WHICH WILL
BREAK DOWN WEST COAST RIDGE AND MOVE ACROSS PAC NW WED AND INTO THE
PLAINS THU. CONSIDERABLE SPREAD IN LATEST MODELS ON
TIMING/STRENGTH/TRACK OF THIS SYSTEM. ECMWF AND GFS OVER THE PAST
24HRS HAVE SLOWED EASTWARD MOVEMENT OF THE SHRTWV ACROSS THE COUNTRY
AND AS SUCH HAVE LOWERED POPS FOR THU. UPR TROF SHOULD RESULT IN TWO
SFC LOWS MOVG INTO THE PLAINS THU... WITH ONE MOVG SE FROM THE NRN
PLAINS AND THE OTHER MOVG NE FROM THE SRN PLAINS THROUGH FRI. SRN
LOW WILL HAVE MUCH MORE MOISTURE TO WORK WITH AND THUS GREATER
POTENTIAL TO PRODUCE BAND OF SGFNT SNOW IN OR CLOSE TO OUR CWA.
GIVEN RATHER LARGE MODEL DIFFERENCES ON TRACK OF SRN LOW...
CONSIDERABLE UNCERTAINTY REMAINS AS TO WHERE THIS WILL BE... BUT
APPEARS ATTM SRN PORTION OF OUR CWA OR POINTS FARTHER SOUTH HAVE
GREATEST POTENTIAL.
ANOTHER SURGE OF COLD AIR SHOULD FOLLOW THU NGT`S LOW INTO THE AREA
WITH BLO NORMAL TEMPS AND SOME LES FRI-SAT. SFC HIGH PASSING TO THE
EAST WITH MORE ZONAL FLOW ALOFT SHOULD RESULT IN A WARMING TREND
SUNDAY-MONDAY. MEDIUM RANGE MODELS INDICATE A WK SHRTWV MAY MOVE
THROUGH THE AREA IN THIS TIMEFRAME BUT GIVEN DISAGREEMENTS ON TIMING
WITH SUCH A WK FEATURE... OPTED TO LEAVE PRECIP CHANCES OUT
OF FCST FOR NOW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND CHILL ADVISORY FROM 8 PM EST /7 PM CST/ THIS EVENING TO 11
AM EST /10 AM CST/ TUESDAY FOR INZ003>009-012>018-020-
022>027-032>034.
MI...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM EST TUESDAY
FOR MIZ080-081.
LAKE EFFECT SNOW ADVISORY UNTIL 5 AM EST TUESDAY FOR MIZ077>079.
OH...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM EST TUESDAY
FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...FISHER
LONG TERM...JT
UPDATE...T
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS WICHITA KS
1147 PM CST MON JAN 21 2013
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD.
LITTLE CHANGE TO THE PREVIOUS FORECAST...AS A DRY NORTHWEST FLOW
REGIME ALOFT WILL CONTINUE AS A SHALLOW POLAR AIRMASS CONTINUES TO
GRIP THE PLAINS. STRATUS AND STRATOCU CIGS WITHIN THE MORE FIRMLY
ENTRENCHED COLD AIR IS EXPECTED TO REMAIN JUST NORTH AND EAST OF
THE AREA...THOUGH A FEW LOWER CLOUDS AND A PERIOD OF ALTOCU WILL
AFFECT PORTIONS OF CENTRAL AND EASTERN KANSAS OVERNIGHT. THE LIGHT
EASTERLY COMPONENT SURFACE FLOW WILL VEER MORE SOUTHEASTERLY ON
TUESDAY.
KED
&&
.PREV DISCUSSION... /ISSUED 546 PM CST MON JAN 21 2013/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD.
A DRY NORTHWEST FLOW REGIME ALOFT WILL CONTINUE AS A SHALLOW POLAR
AIRMASS CONTINUES TO GRIP THE PLAINS. STRATOCU CIGS WITH THE MORE
FIRMLY ENTRENCHED COLD AIR IS EXPECTED TO REMAIN JUST NORTH AND
EAST OF THE AREA WITH THE SURFACE FLOW TAKING ON A GENERAL LIGHT
EASTERLY COMPONENT.
KED
PREV DISCUSSION... /ISSUED 320 PM CST MON JAN 21 2013/
DISCUSSION...
TODAY-WED:
COMPLEX SURFACE PATTERN WITH REALLY COLD AIR SLOWLY BACKDOORING
INTO FORECAST AREA...AND SOME RETURN FLOW DEVELOPING IN FAR
WESTERN SECTIONS. NOT A LOT OF CONFIDENCE IN ANY OF THE MODELS
ABILITY TO RESOLVE LOCATION OF COLDEST AIR AND RESULTANT LOW
CLOUDS. BEST GUESS IS FOR COLD AIR TO CONTINUE TO SAG AT LEAST
OVERNIGHT... POTENTIALLY LEAVING A SHARP BOUNDARY SOMEWHERE ACROSS
THE AREA ON TUE. ANTICIPATE ANY LOW CLOUDS EARLY IN THE MORNING
WILL BE ERODED FAIRLY QUICKLY AND WILL HAVE FAIR AMOUNT OF
MODIFICATION OF COLD AIR NEAR BOUNDARY. BEST GUESS FOR WED IS
LITTLE SURFACE FLOW... PROBABLY OUT OF THE EAST. THIS SHOULD
RECIRCULATE COOL AIR...SO NOT EXPECTING MUCH RECOVERY AT THIS TIME.
WED NIGHT-FRI:
RETURN FLOW BEGINS TO DEVELOP ON BOTH ECMWF/GFS...WITH BOTH
SHOWING 850MB MOISTURE WORKING NORTH...PRIMARY AFFECTING SOUTHERN
SECTIONS DURING THE PERIOD. REMAINS TO BE SEEN WHETHER THERE WILL
BE ENOUGH LIFT/MOISTURE TO OVERCOME DRY AIR NEAR SURFACE. BEST
LIFT COMES THU AFTERNOON AND ESPECIALLY FRI MORNING. BEST CHANCE
FOR PRECIPITATION THU WILL LIKELY BE IN SOUTHEAST KS IN THE
AFTERNOON. BY FRI MORNING DRIER AIR WILL HAVE OVERSPREAD THE
ENTIRE AREA. COLDER AIR SHOULD BE SPILLING INTO THE AREA ON
FRI...WITH HIGH TEMPERATURES LOWER THAN ON THU.
SAT-MON:
GOOD AGREEMENT THAT LARGE SURFACE HIGH WILL DROP SOUTH ACROSS THE
PLAINS ON SAT...WITH RETURN FLOW DEVELOPING ON SUN. HOWEVER SPREAD
BETWEEN GFS/ECMWF STARTS TO INCREASE SIGNIFICANTLY DUE TO HANDLING
OF SHORTWAVE MOVING THROUGH AND LONG WAVE TROUGH IN THE WESTERN
US. BOTH APPEAR TO BE OVERLY AGRESSIVE WITH RETURN MOISTURE ON SUN
AND MON AND HAVE OPTED TO KEEP FORECAST DRY FOR NOW. GIVEN SOUTHERN
EXTENT OF SURFACE HIGH AND SURFACE TRAJECTORIES DURING THE PERIOD...
SEEMS UNLIKELY TO GET SUFFICIENT MOISTURE THIS FAR NORTH THAT QUICK.
SHOULD SEE TEMPERATURES REBOUND NICELY GIVEN RELATIVELY DRY AIR/DRY
GROUND/SUNSHINE AND RETURN FLOW. -HOWERTON
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
KRSL-KSLN-KCNU WILL BE FLIRTING WITH LOW VFR TO HIGH MVFR CIGS
THIS AFTERNOON-EVENING...AND POSSIBLY THROUGH TONIGHT...AS
SHALLOW COLD AIR TIED TO ARCTIC HIGH PRESSURE ENCROACHES FROM THE
NORTHEAST. FOR NOW PLAYED THE CONSERVATIVE APPROACH...ALTHOUGH IF
LATEST RUC BUFR SOUNDINGS VERIFY CIGS LESS THAN 2000 FT AGL COULD
PREVAIL AS FAR SOUTH AS KHUT AND KICT BY MIDNIGHT. MODELS TEND TO
NOT HANDLE SHALLOW COLD AIRMASSES VERY WELL...SO WILL CONTINUE TO
MONITOR.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 18 45 26 52 / 0 0 0 0
HUTCHINSON 17 44 25 51 / 0 0 0 0
NEWTON 17 42 25 50 / 0 0 0 0
ELDORADO 16 41 25 52 / 0 0 0 0
WINFIELD-KWLD 19 46 27 57 / 0 0 0 0
RUSSELL 15 40 22 51 / 0 0 0 0
GREAT BEND 18 44 25 52 / 0 0 0 0
SALINA 15 38 22 49 / 0 0 0 0
MCPHERSON 16 42 24 50 / 0 0 0 0
COFFEYVILLE 17 44 27 58 / 0 0 10 10
CHANUTE 15 39 24 53 / 0 0 10 10
IOLA 15 37 24 51 / 0 0 0 0
PARSONS-KPPF 14 42 24 57 / 0 0 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 AM EST TUE JAN 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 431 AM EST TUE JAN 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STEADY STATE HI
AMPLITUDE PATTERN WITH DEEP TROF OVER ERN NAMERICA DOWNSTREAM OF RDG
ALONG THE W COAST. CORE OF ARCTIC AIR AT 00Z WAS CENTERED IN NW
ONTARIO OVER YPL...WHICH REPORTED LOWEST H85 TEMP ON THE MAP WITH
-36C. INL/RB ALSO REPORTED NOTEWORTHY H85 TEMPS OF -30C/-31C AT 00Z.
FARTHER NW OF THIS CORE OF COLDEST AIR...00Z H85 TEMPS AT THE PAS
MANITOBA AND CHURCHILL MANITOBA WERE A MUCH MORE MODEST -23C. A FEW
PLACES OVER INTERIOR UPR MI HAVE SEEN SFC TEMPS FALL AS LO AS -15 TO
-20F...WITH LOWEST WIND CHILLS IN THE -30 TO -35F RANGE. WITH
LINGERING CYC NW FLOW OVER THE UPR LKS UNDER THIS BITTERLY COLD
AIR...LES CONTINUES MAINLY IN THE NW WIND SN BELTS. AS EXPECTED...
WITH VERY COLD AIR ELIMINATING THE DGZ...SNOWFLAKE SIZE HAS BEEN
VERY SMALL. THE SMALL FLAKES ARE VERY EFFECTIVE AT REDUCING VSBY...
SO WHERE LES IS OCCURRING...WHITE-OUTS ARE COMMON. FOR THE MOST
PART...SMALL FLAKES ARE LIMITING ACCUMS WITH MOST RECENT SPOTTER/
COOP REPORTS INDICATING MOSTLY 1-3IN/12HR SNOWFALL RATES. EXCEPTION
IS OVER THE FAR NE FCST AREA...WHERE MORE LONGER FETCH/MORE LK
MODERATION IS LIKELY ALLOWING THE DGZ INTO THE LOWEST LYRS AND
SHARPER LLVL CNVGC ENHANCED BY LAND BREEZES IS PROVIDING EXTRA LLVL
LIFT/FOCUS FOR SHSN. LOOKING JUST UPSTREAM TO THE NW...A WEAKER PRES
GRADIENT IS APPARENT UPSTREAM OF LK SUP.
TODAY...CWA WL REMAIN UNDER PERSISTENT NW FLOW ALF...BUT CORE OF
COLDEST AIR NOW IN PLACE IS PROGGED TO SHIFT TO THE E AS THE LLVL
FLOW BACKS...WITH H85 TEMPS FCST TO RISE TO WITHIN A FEW DEGREES OF
-25C BY 00Z THIS EVNG. COMBINATION OF CORE OF COLDEST AIR SHIFTING
TO THE E AND LIGHTER WINDS THAN YDAY WITH ARRIVAL OF WEAKER PRES
GRADIENT SHOULD ALLOW SOME MODERATION IN THE WIND CHILLS. SO GOING
ADVY EXPIRATION OF THOSE ADVYS AT 18Z LOOKS ON TRACK. HOWEVER...THE
AIRMASS WL REMAIN MORE THAN SUFFICIENTLY COLD FOR PERSISTENT LES/LK
CLDS DESPITE LARGER SCALE QVECTOR DVGC/SUBSIDENCE THAT IS FCST TO
LOWER INVRN BASE TOWARD 5K FT AND LIMIT DEPTH OF MSTR. BUT FCST
SDNGS STILL SHOW TEMPS WITHIN THE COLUMN WL REMAIN TOO LO FOR SN
FLAKE GROWTH...SO EXPECT FINER FLAKES TO REMAIN THE RULE. HEAVIER
LES WITH SOMEWHAT HIER TEMPS MODERATED BY LONGER FETCH OVER THE LK
AND LINGERING SHARPER LLVL CNVGC WL REMAIN THE RULE IN AREAS E OF
MUNISING. AS THE LARGER SCALE FLOW BACKS MORE WNW...EXPECT THE LES
OVER THE ERN CWA TO BECOME MORE CONFINED TO AREAS NEAR LK SUP E OF
MUNISING. OVER THE W...THE LES BANDS SHOULD SHIFT N OUT OF GOGEBIC
COUNTY BUT STILL IMPACT AREAS FM ONTONAGON THRU THE KEWEENAW.
TNGT...EXPECT A CONTINUED SLOW MODERATION AS LLVL WNW FLOW SHIFTS
COLDEST H85 AIR TO THE E. BY 12Z...H85 TEMPS ARE PROGGED TO BE ARND
-22C. LES SHOULD BE CONFINED TO MAINLY AREAS N OF ONTONAGON OVER THE
W AND TO NEAR LK SUP E OF PICTURED ROCKS OVER THE ERN CWA. WITH SOME
MODERATION IN THE CHILL...SN/WATER RATIOS WL LIKELY BECOME HIER WITH
EMERGENCE OF THE DGZ IN THE LOWEST FEW THOUSAND FEET OF THE
CONVECTIVE LYR. WITH THE MODERATING AIRMASS...MIN TEMPS WL NOT BE AS
LO AS THIS MRNG AT MOST SPOTS EXCEPT OVER THE INTERIO WCNTRL WHERE
LIGHTER WINDS AND AT LEAST SOME CLRG WL ALLOW MORE RADIATION
COOLING. SINCE WINDS OVER THE COLDER INTERIOR SHOULD GENERALLY BE
UNDER 10 MPH...SUSPECT WIND CHILLS FOR THE MOST PART WL REMAIN ABV
ADVY CRITERIA. OPTED TO EXTEND LES WRNG FOR ALGER/LUCE COUNTIES AND
WINTER WX ADVY FOR ONTONAGON COUNTY/THE KEWEENAW THRU TNGT TO
ACCOUNT FOR EXPECTED TRENDS NOTED ABV.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 431 AM EST TUE JAN 22 2013
MODELS ARE IN GOOD AGREEMENT THROUGH ALL BUT SUN/MON...SO FORECAST
CONFIDENCE IS HIGH THROUGH MOST OF THE LONG TERM.
WED AND WED NIGHT...AN UPPER TROUGH WILL PUSH THROUGH THE CWA
WED...HELPING FORM A MESO-LOW /AS INDICATED BY MAJORITY OF MODELS/
OVER FAR ERN LAKE SUPERIOR. WINDS WILL INITIALLY BE OUT OF THE WNW
WED MORNING...BUT WILL TURN NLY BY 00Z THU AFTER THE TROUGH
PASSES...THE MESO LOW DIMINISHES AND A SFC HIGH BEGINS PUSHING IN
FROM THE NW. 850MB TEMPS WILL START THE DAY AROUND -22C AND END THE
DAY AROUND -25C. EARLY IN THE DAY CONDITIONS WILL BE PRIME FOR
MODERATE TO LOCALLY HEAVY LES...BUT BY TIME WINDS TURN NLY...DRY AIR
AND LOWERING INVERSIONS WILL BEGIN TO LIMIT LES TO LIGHT TO MODERATE
INTENSITY. BY 12Z THU...WINDS WILL BE LIGHT AND QUITE ANTICYCLONIC
OVER LAKE SUPERIOR AS THE HIGH CENTER IS JUST NW OF THE LAKE. EXPECT
DIMINISHING LES THROUGH WED NIGHT. HIGHEST SNOWFALL AMOUNTS FOR WED
THROUGH WED NIGHT LOOK TO BE E OF MUNISING NEAR LAKE SUPERIOR WITH
OVER 6 INCHES AND FROM ONTONAGON TO TWIN LAKES WITH OVER 5 INCHES.
ELSEWHERE NEAR LAKE SUPERIOR...EXPECT 2-4 INCHES.
THU...THE SFC HIGH WILL SHIFT E OF THE CWA THROUGH THE
DAY...REACHING THE LOWER GREAT LAKES BY 00Z FRI. THIS PUTS THE
REGION UNDER S-SE LOW LEVEL FLOW BEHIND THE HIGH AND AHEAD OF A
TROUGH AND SFC LOW THAT WILL BE OVER THE DAKOTAS AT 00Z FRI.
THU NIGHT AND FRI...SLY FLOW CONTINUES AS THE TROUGH/SFC LOW MOVES
TO SE MN BY 12Z FRI...CAUSING 850MB TEMPS TO WARM TO THE MID TEENS
BELOW ZERO. SHOULD SEE LAKE EFFECT/ENHANCED SNOW OFF LAKE MI AHEAD
OF THE SYSTEM...HELPING TO BOOST SNOWFALL TOTALS IN SCHOOLCRAFT AND
LUCE COUNTIES DEPENDING ON EXACT WIND DIRECTION. THE INVERTED TROUGH
N OF THE SFC LOW WILL MOVE TO THE CENTRAL CWA AROUND 18Z FRI...THEN
TO THE ERN CWA BY 00Z SAT. MODELS SHOW AROUND 0.2 INCHES OF SYNOPTIC
QPF...AND NEARLY DOUBLE THAT DOWNWIND OF LAKE MICHIGAN. LOOKING AT
MODEL PROFILES...THE BEST LIFT WILL BE ABOVE THE FAIRLY SHALLOW
DGZ...SO SNOW TO LIQUID RATIOS WILL PROBABLY NOT BE THAT HIGH. AT
THIS POINT IT LOOKS LIKE MOST LOCATIONS WILL SEE AROUND 3 INCHES OF
SNOW WITH POSSIBLY 6 INCHES DOWNWIND OF LAKE MICHIGAN.
A SHORTWAVE TROUGH LOOKS TO MOVE THROUGH LATE FRI INTO EARLY SAT
NIGHT...WHICH SHOULD HELP GIVE A BRIEF BOOST TO LES IN THE NNW LOW
LEVEL WINDS AND 850MB TEMPS AROUND -17C. ANY GOOD LES SHOULD NOT
LAST LONG AS A SFC HIGH RIDGE MOVES TO WRN LAKE SUPERIOR AND 850MB
TEMPS INCREASE TO AROUND -13C BY 18Z. LOW LEVEL FLOW ONCE AGAIN
BECOMES SELY BEHIND THE RIDGE SAT NIGHT WITH 850MB TEMPS INCREASING
TO A BALMY -5 OR SO BY 12Z SUN. FOR SUN AND MON...MODELS DO NOT HAVE
GOOD AGREEMENT...BUT THEY SUGGEST THAT A SHORTWAVE MAY MOVE
SOMEWHERE NEAR OR OVER THE AREA SUN OR SUN NIGHT. JUST USED A
CONSENSUS OF MODELS FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 630 PM EST MON JAN 21 2013
LAKE EFFECT SNOW SHOWERS WILL CONTINUE OVER MAINLY THE IWD AND CMX
TAF SITES THROUGH TUESDAY AFTERNOON. VISIBILITY WILL BE REDUCED TO
1/4 MILE AT TIMES AS THE HEAVIER SNOWBANDS MOVE THROUGH. IWD WILL
LIKELY SEE A BRIEF BREAK IN THE SNOW SHOWERS EARLY THIS EVENING
BEFORE THE NEXT AREA OF SNOW SHOWERS BUILDS SOUTHWARD INTO THE SITE.
WINDS WILL ALSO BE GUSTING TO 20 KTS OR BETTER ALLOWING FOR
INCREASED BLSN POTENTIAL...ALSO HELPING TO REDUCE VSBY. CEILINGS ARE
EXPECTED TO REMAIN AROUND 1500 TO 2000 FT AT CMX AND IWD.
KSAW WILL REMAIN AT MVFR THROUGH TUESDAY MORNING AS INCREASED
MOISTURE MOVES INTO THE TAF SITE. DOWNSLOPING WESTERLY WINDS WILL
HELP TO ERODE THE CLOUD COVER THROUGH THE LATE MORNING AND EARLY
AFTERNOON HOURS...POSSIBLY SCATTERING OUT BY 19Z. VSBY SHOULD REMAIN
VFR THROUGH THE TAF PERIOD WITH ONLY MINOR REDUCTION IN VSBY THIS
EVENING WITH GUSTY WINDS CREATING BLSN. WEST TO NORTHWEST WINDS ARE
NOT A FAVORED LAKE EFFECT DIRECTION FOR KSAW...THEREFORE HAVE KEPT
-SHSN OUT OF THE TAF ALTHOUGH A FEW SNOW SHOWERS ARE STILL POSSIBLE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 AM EST TUE JAN 22 2013
EXPECT NW WINDS UP TO 20 TO 25 KTS THRU TONIGHT TO DRIVE ARCTIC AIR
OVER THE UPPER GREAT LAKES. THERE WILL BE PERIODS OF HEAVY FREEZING
SPRAY IN AREAS WHERE THE WINDS ARE STRONGEST. THE NW WINDS WILL
STRENGTHEN TO 25 TO 30 KTS ON WED FOLLOWING THE PASSAGE OF A
DISTRUBANCE...CAUSING MORE HEAVY FREEZING SPRAY THRU WED NIGHT. A
WEAKER PRES GRADIENT/LIGHTER WINDS AND SOME MODERATION OF THE CHILL
WILL END THE HEAVY FREEZING SPRAY BY THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001>003-
084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ085.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MIZ009.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST WEDNESDAY FOR MIZ006-007.
WIND CHILL ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR
MIZ004-005-010>014.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY
FOR LSZ240>251-263>267.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
THURSDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KEC
MARINE...KC
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
1206 AM CST TUE JAN 22 2013
.AVIATION.../06Z GRI TAF THROUGH 06Z TUESDAY NIGHT/
THRU 12Z: MVFR CIGS SEEM TO BE EXPANDING WHICH INCREASES
CONFIDENCE THAT MVFR CIGS WILL PREVAIL...BUT CONFIDENCE IS ONLY
AVERAGE BECAUSE THE EDGE IS BETWEEN ODX AND GRI. LIGHT SE WINDS 5
KTS OR LESS. UNRESTRICTED VSBYS.
TUE: MVFR OR LOW-END VFR OVC THRU 20Z...BUT AS TEMPS INCREASE
CLEARING WILL MOVE THRU AFTER 21Z. SE WINDS AT OR BELOW 10 KTS.
UNRESTRICTED VSBYS.
TUE EVE: ESSENTIALLY VFR SKC. SE WINDS AROUND 5 KTS.
CIG CONFIDENCE: AVERAGE THRU 21Z THEN HIGH
VSBY CONFIDENCE: HIGH
WIND CONFIDENCE: HIGH
WX CONFIDENCE: HIGH
&&
.PREV DISCUSSION... /ISSUED 957 PM CST MON JAN 21 2013/
UPDATE...THE RUC CONTINUES TO GENERATE LIGHT SNOW ACROSS OUR
NORTHEAST ZONES THIS EVENING...WHICH THUS FAR HAS FAILED TO
MATERIALIZE. THE NAM PUTS THE BEST CHANCE OF LIGHT SNOW JUST TO
THE NORTHEAST OF OUR CWA AFTER MIDNIGHT. OVERALL CONFIDENCE IN
SEEING LIGHT SNOWFALL ACCUMULATIONS ACROSS OUR NORTHEAST ZONES HAS
DECREASED AND THEREFORE HAVE TRENDED SLIGHTLY LOWER WITH POPS.
PREV DISCUSSION... /ISSUED 245 PM CST MON JAN 21 2013/
SHORT TERM...TONIGHT AND TUESDAY. FOCUS IS ON LIGHT SNOW POTENTIAL
FOR TONIGHT. THE PATTERN ALOFT PLACED AN UPPER RIDGE AXIS ALONG THE
WEST COAST STATES...NORTHWEST FLOW ACROSS THE INTERIOR CONUS WITH
AN UPPER LOW ORIENTED FM ONTARIO SOUTH THRU THE OHIO VALLEY. AN
ARCTIC AIRMASS HAD SETTLED ACROSS THE DAKOTAS THRU THE EASTERN
PORTIONS OF THE CENTRAL PLAINS STATES...AND AT THE SURFACE...A 1032MB
SURFACE HIGH WAS ORIENTED ALONG THE MISSOURI RIVER.
BANDS OF SNOW DEVELOPED THIS MORNING ACROSS OUR NORTHERN/EASTERN
ZONES AS A 150KT JET STREAK NOSED SOUTH ALONG THE MISSOURI
RIVER...DRIVING SHEARED ENERGY SOUTH ACROSS THE PLAINS. THE SNOW
DEVELOPED IN AN AREA OF MID LEVEL FRONTOGENESIS AND THE AREA OF LIFT
WAS ALSO DEPICTED WELL ON THE 290K ISENTROPIC SURFACE. HAD A REPORT
OF SOME AREAS PICKING UP SNOW OF A HALF INCH TO THREE QUARTERS OF AN
INCH IN THE HEAVIER BANDS...AND VSBYS DROPPED BELOW TWO MILES AT
TIMES.
MODELS ARE PRETTY CONSISTENT INDICATING THAT THIS INITIAL ROUND OF
SNOW WILL CONTINUE TO WIND DOWN THIS AFTERNOON IN DECREASING
LIFT/DYNAMICS...WITH ANOTHER ROUND OF SNOW SETTING UP THIS
EVENING/TONIGHT. LIFT INCREASES AGAIN TONIGHT WITH A 130KT JET
STREAK NOSING SOUTH THRU EASTERN NEBRASKA...AGAIN NEAR THE MISSOURI
RIVER. THIS AGAIN DRIVES SHEARED ENERGY SOUTH AND ISENTROPIC LIFT
INCREASES THIS EVENING WITH BETTER LIFT HEADING INTO TONIGHT. SNOW
IS EXPECTED TO REDEVELOP ACROSS OUR NORTHERN ZONES INITIALLY AND
SPREAD SOUTH AND AFFECT OUR EAST/NORTHEAST ZONES OVERNIGHT...OR
GENERALLY PRETTY MUCH ACROSS THE SAME AREAS WHICH SAW SNOWFALL
TODAY. SNOWFALL ACCUMULATIONS ARE EXPECTED TO REMAIN RATHER
LIGHT...GENERALLY A DUSTING TO UP TO ONE INCH. THE LIGHT SNOWFALL
POTENTIAL IS BEST SUPPORTED BY SREF...12Z SPC WRF AND RUC/RAP.
DECIDED TO HANDLE THIS EVENT WITH HIGH POPS AND LOW SNOWFALL
ACCUMULATIONS. SET UP LOOKS GOOD FOR SNOW BUT AMOUNTS SHOULD NOT
BE HIGH.
CURRENT FORECAST HAS FOG POTENTIAL TONIGHT...AND LEFT THIS IN AS
DEVELOPMENT STILL LOOKS POSSIBLE ALONG OUR SOUTHERN/WESTERN ZONES IN
LIGHT EASTERLY RETURN FLOW FM SFC HIGH TO THE EAST AND THESE
LOCATIONS WILL ALSO BE ON THE EDGE/PERIPHERY OF THE STRATUS. HRRR
VSBY PROGS ACTUALLY INDICATE POTENTIAL FOR DENSE FOG ACROSS PORTIONS
OF WESTERN NEB/KS WITH OUR WESTERN ZONES ON THE EDGE OF THIS.
DEFINITELY SOMETHING TO KEEP AN EYE ON TONIGHT.
SOME FLURRIES MAY LINGER FOR A FEW HOURS TUESDAY MORNING IN OUR
NORTHEAST...WITH POTENTIAL FOR FOG REMAINING IN THE MORNING IN OUR
SOUTH/WEST. THE SURFACE RIDGE AXIS CONTINUES TO GRADUALLY SHIFT EAST
AND HEIGHTS BEGIN TO RISE ACROSS THE PLAINS. LOW CLOUDS BEGIN TO
ERODE FM WEST/EAST BUT STILL NOT LOOKING FOR A WHOLE LOT OF
IMPROVEMENT IN TEMPS TOMORROW AFTN IN OUR EAST...ALTHOUGH SOME LOW
20S ARE POSSIBLE. TO THE WEST...IN INCREASING INSOLATION AND
PROXIMITY TO WARMER AIR...READINGS NEAR 40F ARE POSSIBLE.
LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN
LIES WITH TEMPERATURES.
NORTHWESTERLY FLOW IN THE UPPER LEVELS IS EXPECTED TO BE IN PLACE AT
THE START OF THE LONG TERM PERIOD...WITH BROAD TROUGHING IN PLACE
OVER THE MIDWEST/EAST COAST AND A RIDGE AXIS EXTENDING THROUGH THE
ROCKIES AND INTO CANADA. THE SURFACE PATTERN STARTS OUT WITH LIGHT
GENERALLY SOUTHERLY WINDS ACROSS THE CWA...AS HIGH PRESSURE
ENCOMPASSES MUCH OF THE CONUS EAST OF THE MO RIVER...AND A TROUGH OF
LOW PRESSURE REMAINS OVER THE HIGH PLAINS.
THE FORECAST THROUGH WEDNESDAY NIGHT REMAINS DRY WITH NO NOTABLE
SYSTEMS TAKING AIM ON THE REGION...THOUGH AN UPPER LEVEL DISTURBANCE
SWINGING OUT OF CANADA AND INTO THE GREAT LAKES REGION DURING THE
DAYTIME HOURS ON WEDNESDAY WILL HAVE SOME IMPACT ON OUR CWA. A
BACKDOOR FRONT WILL WORK ITS WAY INTO THE AREA FROM THE
N/NE...BRINGING NE/E WINDS AND IS EXPECTED TO KEEP ROUGHLY THE
NORTHEASTERN HALF OF THE CWA IN THE MID/UPPER 30S FOR HIGHS...WITH
THE SOUTH AND WEST IN THE 40S.
A LITTLE MORE UNCERTAINTY IN THE FORECAST ARISES AS WE GET INTO
THURSDAY...MAINLY WITH THE TIMING OF ANOTHER COLD FRONT EXPECTED TO
PUSH THROUGH THE NRN/CENTRAL PLAINS. ANOTHER...STRONGER UPPER LEVEL
DISTURBANCE WILL AGAIN PUSH OUT OF CENTRAL CANADA AND MOVE SOUTHEAST
THROUGH THE NORTHERN PLAINS AND EVENTUALLY INTO THE MIDWEST. THE
12Z NAM WAS AN OUTLIER COMPARED TO OTHER MODELS WITH THE TIMING OF
THE FRONT...ALREADY MAKING A GOOD PUSH THROUGH THE CWA BY MIDDAY
THURSDAY...WITH THE EC/GFS/SREF ALL SLOWER AND BRINGING THE FRONT
TROUGH MORE DURING THE THURS EVENING/OVERNIGHT HOURS. KEPT THE
FORECAST CLOSER TO THOSE SLOWER SOLUTIONS. AS HAS BEEN THE CASE THE
PAST FEW DAYS...MODELS CONTINUING TO SHOW BETTER PRECIPITATION
CHANCES REMAINING WELL TO THE SOUTH OF THE CWA CLOSER TO THE MAIN
SFC WARM FRONT...AND TO THE NORTH WITH THE BETTER UPPER LEVEL
FORCING. THIS FRONT WILL USHER IS COLDER AIR AND LOWER TEMPERATURES
FOR FRIDAY...AND FORECAST HIGHS RANGE FROM THE LOWER 20S IN THE
NORTHEAST TO THE UPPER 30S IN THE SOUTHWEST.
ALREADY FRIDAY NIGHT...MODELS IN GOOD AGREEMENT SHOWING THIS LATEST
BATCH OF COLDER STARTING TO SHIFT OFF TO THE EAST OF THE CWA...AS
RIDGING STARTS TO REAMPLIFY OVER THE ROCKIES WITH ANOTHER UPPER
LEVEL TROUGH OF THE WEST COAST. THIS RIDGE LOOKS TO REMAIN THE MAIN
PLAYER IN THE UPPER LEVELS THROUGH AT LEAST THE UPCOMING
WEEKEND...WITH A LITTLE MORE UNCERTAINTY WHETHER IT CONTINUES INTO
MONDAY LIKE THE 12Z EC IS SHOWING /THE GFS SHOWS ANOTHER FRONT
MOVING THROUGH/. FORECAST CURRENTLY CALLING FOR MID 30S/MID 40S FOR
HIGHS ON SAT...WITH MID 40S/LOWER 50S FOR SUN/MON. IF THE ECMWF
SOLUTION IS THE ONE OTHER MODELS TREND TOO...MAY NEED UPWARD TWEAKS
FOR SUN/MON TEMPS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...HALBLAUB 1206
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1137 PM CST MON JAN 21 2013
.AVIATION.../06Z GRI TAF THROUGH 06Z TUESDAY NIGHT/
THRU 12Z: MVFR CIGS SEEM TO BE EXPANDING WHICH INCREASES
CONFIDENCE THAT MVFR CIGS WILL PREVAIL...BUT CONFIDENCE IS ONLY
AVERAGE BECAUSE THE EDGE IS BETWEEN ODX AND GRI. LIGHT SE WINDS 5
KTS OR LESS. UNRESTRICTED VSBYS.
TUE: MVFR OR LOW-END VFR OVC THRU 20Z...BUT AS TEMPS INCREASE
CLEARING WILL MOVE THRU AFTER 21Z. SE WINDS AT OR BELOW 10 KTS.
UNRESTRICTED VSBYS.
TUE EVE: ESSENTIALLY VFR SKC. SE WINDS AROUND 5 KTS.
&&
.PREV DISCUSSION... /ISSUED 957 PM CST MON JAN 21 2013/
UPDATE...THE RUC CONTINUES TO GENERATE LIGHT SNOW ACROSS OUR
NORTHEAST ZONES THIS EVENING...WHICH THUS FAR HAS FAILED TO
MATERIALIZE. THE NAM PUTS THE BEST CHANCE OF LIGHT SNOW JUST TO
THE NORTHEAST OF OUR CWA AFTER MIDNIGHT. OVERALL CONFIDENCE IN
SEEING LIGHT SNOWFALL ACCUMULATIONS ACROSS OUR NORTHEAST ZONES HAS
DECREASED AND THEREFORE HAVE TRENDED SLIGHTLY LOWER WITH POPS.
PREV DISCUSSION... /ISSUED 245 PM CST MON JAN 21 2013/
SHORT TERM...TONIGHT AND TUESDAY. FOCUS IS ON LIGHT SNOW POTENTIAL
FOR TONIGHT. THE PATTERN ALOFT PLACED AN UPPER RIDGE AXIS ALONG THE
WEST COAST STATES...NORTHWEST FLOW ACROSS THE INTERIOR CONUS WITH
AN UPPER LOW ORIENTED FM ONTARIO SOUTH THRU THE OHIO VALLEY. AN
ARCTIC AIRMASS HAD SETTLED ACROSS THE DAKOTAS THRU THE EASTERN
PORTIONS OF THE CENTRAL PLAINS STATES...AND AT THE SURFACE...A 1032MB
SURFACE HIGH WAS ORIENTED ALONG THE MISSOURI RIVER.
BANDS OF SNOW DEVELOPED THIS MORNING ACROSS OUR NORTHERN/EASTERN
ZONES AS A 150KT JET STREAK NOSED SOUTH ALONG THE MISSOURI
RIVER...DRIVING SHEARED ENERGY SOUTH ACROSS THE PLAINS. THE SNOW
DEVELOPED IN AN AREA OF MID LEVEL FRONTOGENESIS AND THE AREA OF LIFT
WAS ALSO DEPICTED WELL ON THE 290K ISENTROPIC SURFACE. HAD A REPORT
OF SOME AREAS PICKING UP SNOW OF A HALF INCH TO THREE QUARTERS OF AN
INCH IN THE HEAVIER BANDS...AND VSBYS DROPPED BELOW TWO MILES AT
TIMES.
MODELS ARE PRETTY CONSISTENT INDICATING THAT THIS INITIAL ROUND OF
SNOW WILL CONTINUE TO WIND DOWN THIS AFTERNOON IN DECREASING
LIFT/DYNAMICS...WITH ANOTHER ROUND OF SNOW SETTING UP THIS
EVENING/TONIGHT. LIFT INCREASES AGAIN TONIGHT WITH A 130KT JET
STREAK NOSING SOUTH THRU EASTERN NEBRASKA...AGAIN NEAR THE MISSOURI
RIVER. THIS AGAIN DRIVES SHEARED ENERGY SOUTH AND ISENTROPIC LIFT
INCREASES THIS EVENING WITH BETTER LIFT HEADING INTO TONIGHT. SNOW
IS EXPECTED TO REDEVELOP ACROSS OUR NORTHERN ZONES INITIALLY AND
SPREAD SOUTH AND AFFECT OUR EAST/NORTHEAST ZONES OVERNIGHT...OR
GENERALLY PRETTY MUCH ACROSS THE SAME AREAS WHICH SAW SNOWFALL
TODAY. SNOWFALL ACCUMULATIONS ARE EXPECTED TO REMAIN RATHER
LIGHT...GENERALLY A DUSTING TO UP TO ONE INCH. THE LIGHT SNOWFALL
POTENTIAL IS BEST SUPPORTED BY SREF...12Z SPC WRF AND RUC/RAP.
DECIDED TO HANDLE THIS EVENT WITH HIGH POPS AND LOW SNOWFALL
ACCUMULATIONS. SET UP LOOKS GOOD FOR SNOW BUT AMOUNTS SHOULD NOT
BE HIGH.
CURRENT FORECAST HAS FOG POTENTIAL TONIGHT...AND LEFT THIS IN AS
DEVELOPMENT STILL LOOKS POSSIBLE ALONG OUR SOUTHERN/WESTERN ZONES IN
LIGHT EASTERLY RETURN FLOW FM SFC HIGH TO THE EAST AND THESE
LOCATIONS WILL ALSO BE ON THE EDGE/PERIPHERY OF THE STRATUS. HRRR
VSBY PROGS ACTUALLY INDICATE POTENTIAL FOR DENSE FOG ACROSS PORTIONS
OF WESTERN NEB/KS WITH OUR WESTERN ZONES ON THE EDGE OF THIS.
DEFINITELY SOMETHING TO KEEP AN EYE ON TONIGHT.
SOME FLURRIES MAY LINGER FOR A FEW HOURS TUESDAY MORNING IN OUR
NORTHEAST...WITH POTENTIAL FOR FOG REMAINING IN THE MORNING IN OUR
SOUTH/WEST. THE SURFACE RIDGE AXIS CONTINUES TO GRADUALLY SHIFT EAST
AND HEIGHTS BEGIN TO RISE ACROSS THE PLAINS. LOW CLOUDS BEGIN TO
ERODE FM WEST/EAST BUT STILL NOT LOOKING FOR A WHOLE LOT OF
IMPROVEMENT IN TEMPS TOMORROW AFTN IN OUR EAST...ALTHOUGH SOME LOW
20S ARE POSSIBLE. TO THE WEST...IN INCREASING INSOLATION AND
PROXIMITY TO WARMER AIR...READINGS NEAR 40F ARE POSSIBLE.
LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN LIES WITH
TEMPERATURES.
NORTHWESTERLY FLOW IN THE UPPER LEVELS IS EXPECTED TO BE IN PLACE AT
THE START OF THE LONG TERM PERIOD...WITH BROAD TROUGHING IN PLACE
OVER THE MIDWEST/EAST COAST AND A RIDGE AXIS EXTENDING THROUGH THE
ROCKIES AND INTO CANADA. THE SURFACE PATTERN STARTS OUT WITH LIGHT
GENERALLY SOUTHERLY WINDS ACROSS THE CWA...AS HIGH PRESSURE
ENCOMPASSES MUCH OF THE CONUS EAST OF THE MO RIVER...AND A TROUGH OF
LOW PRESSURE REMAINS OVER THE HIGH PLAINS.
THE FORECAST THROUGH WEDNESDAY NIGHT REMAINS DRY WITH NO NOTABLE
SYSTEMS TAKING AIM ON THE REGION...THOUGH AN UPPER LEVEL DISTURBANCE
SWINGING OUT OF CANADA AND INTO THE GREAT LAKES REGION DURING THE
DAYTIME HOURS ON WEDNESDAY WILL HAVE SOME IMPACT ON OUR CWA. A
BACKDOOR FRONT WILL WORK ITS WAY INTO THE AREA FROM THE
N/NE...BRINGING NE/E WINDS AND IS EXPECTED TO KEEP ROUGHLY THE
NORTHEASTERN HALF OF THE CWA IN THE MID/UPPER 30S FOR HIGHS...WITH
THE SOUTH AND WEST IN THE 40S.
A LITTLE MORE UNCERTAINTY IN THE FORECAST ARISES AS WE GET INTO
THURSDAY...MAINLY WITH THE TIMING OF ANOTHER COLD FRONT EXPECTED TO
PUSH THROUGH THE NRN/CENTRAL PLAINS. ANOTHER...STRONGER UPPER LEVEL
DISTURBANCE WILL AGAIN PUSH OUT OF CENTRAL CANADA AND MOVE SOUTHEAST
THROUGH THE NORTHERN PLAINS AND EVENTUALLY INTO THE MIDWEST. THE
12Z NAM WAS AN OUTLIER COMPARED TO OTHER MODELS WITH THE TIMING OF
THE FRONT...ALREADY MAKING A GOOD PUSH THROUGH THE CWA BY MIDDAY
THURSDAY...WITH THE EC/GFS/SREF ALL SLOWER AND BRINGING THE FRONT
TROUGH MORE DURING THE THURS EVENING/OVERNIGHT HOURS. KEPT THE
FORECAST CLOSER TO THOSE SLOWER SOLUTIONS. AS HAS BEEN THE CASE THE
PAST FEW DAYS...MODELS CONTINUING TO SHOW BETTER PRECIPITATION
CHANCES REMAINING WELL TO THE SOUTH OF THE CWA CLOSER TO THE MAIN
SFC WARM FRONT...AND TO THE NORTH WITH THE BETTER UPPER LEVEL
FORCING. THIS FRONT WILL USHER IS COLDER AIR AND LOWER TEMPERATURES
FOR FRIDAY...AND FORECAST HIGHS RANGE FROM THE LOWER 20S IN THE
NORTHEAST TO THE UPPER 30S IN THE SOUTHWEST.
ALREADY FRIDAY NIGHT...MODELS IN GOOD AGREEMENT SHOWING THIS LATEST
BATCH OF COLDER STARTING TO SHIFT OFF TO THE EAST OF THE CWA...AS
RIDGING STARTS TO REAMPLIFY OVER THE ROCKIES WITH ANOTHER UPPER
LEVEL TROUGH OF THE WEST COAST. THIS RIDGE LOOKS TO REMAIN THE MAIN
PLAYER IN THE UPPER LEVELS THROUGH AT LEAST THE UPCOMING
WEEKEND...WITH A LITTLE MORE UNCERTAINTY WHETHER IT CONTINUES INTO
MONDAY LIKE THE 12Z EC IS SHOWING /THE GFS SHOWS ANOTHER FRONT
MOVING THROUGH/. FORECAST CURRENTLY CALLING FOR MID 30S/MID 40S FOR
HIGHS ON SAT...WITH MID 40S/LOWER 50S FOR SUN/MON. IF THE ECMWF
SOLUTION IS THE ONE OTHER MODELS TREND TOO...MAY NEED UPWARD TWEAKS
FOR SUN/MON TEMPS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
144 AM EST TUE JAN 22 2013
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL CONTINUE OFF AND ON OVERNIGHT TONIGHT.
COLDER AIR WILL ARRIVE ON GUSTY WEST TO NORTHWEST WINDS LATER
TONIGHT...WHICH WILL ALLOW LAKE EFFECT SNOWS TO DEVELOP. THIS
ACTIVITY WILL DIMINISH ON THURSDAY AS HIGH PRESSURE BRIEFLY MOVES
INTO THE AREA. OUTSIDE OF THE LAKE EFFECT SNOW...PARTLY TO MOSTLY
CLOUDY SKIES AND SCATTERED SNOW SHOWERS OR FLURRIES ARE EXPECTED.
&&
.NEAR TERM /THROUGH TODAY/...
1220 AM UPDATE...
QUICK UPDATE TO GRIDS TO ACCNT FOR MODERATE TO HVY SNOW OVR NRN
ONONDAGA CNTY WITH 1-2.5 INCH PER HR AMNTS. THANKFULLY THIS SNOW
IS MVG QUICKLY INTO ONEIDA CNTY ATTM, THUS NO CHGS TO HEADLINES
NEEDED. ANOTHER BATCH OF SNOW IS MVG THRU THE TWIN TIERS DUE TO
LES OFF OF LK ERIE. EXPECT THIS TO CONTINUE FOR THE NEXT 1-2 HRS
AND HV INCRSD POPS TO LKLY TO ACCNT FOR THIS ACTIVITY AS IT HEADS
EAST. EXPECTING A QUICK HALF INCH TO ONE INCH OF SNOW WITH THESE
SNOW SHOWERS AS THEY PASS THRU THE REGION.
1020 PM UPDATE...
LATEST HIGH-RES MODELS CONTINUE TO ADVERTISE LAKE BAND DEVELOPMENT
EAST OF LAKE ONTARIO THIS EVENING WITH RECENT RADAR TRENDS FROM
BOTH KBUF AND KTYX NOW SHOWING THE INITIAL STAGES OF BAND
DEVELOPMENT. THAT SAID...WE HAVE ELECTED TO EXTEND THE LAKE EFFECT
SNOW WARNING SOUTH TO INCLUDE ALL ONEIDA COUNTY BEGINNING AT 06Z
THIS EVENING. CONSIDERING THE BANDS ARE FORECAST BY HIGH-RES
MODELS TO EXTEND SOUTH INTO ONONDAGA AND MADISON COUNTIES...HAVE
POSTED A LAKE EFFECT SNOW WATCH FOR ZONES BEGINNING AT 15Z TUE
WHERE 5 TO 9 INCHES OF NEW SNOW WILL BE POSSIBLE THROUGH TUE
NIGHT. AS STATED IN THE PREVIOUS UPDATE...MODELS CONTINUE TO SHOW
A FAIR AMOUNT OF BAND MOVEMENT DURING THE DAYLIGHT HOURS WHICH MAY
BE A MANIFESTATION OF CONVECTIVE OVERTURNING DUE TO A STRONGLY
UNSTABLE MIXED LAYER. ONCE THE BAND DOES FORM...WE EXPECT THE
FEATURE TO BE FAIRLY INTENSE WITH HOURLY SNOWFALL RATES OF 1-2"/HR
DEFINITELY A POSSIBILITY CONSIDERING HIGH INVERSION LEVELS (>14
KFT) AND STRONG INSTABILITY. ELSEWHERE...EVERYTHING REMAINS ON
TRACK AND NO MAJOR ADJUSTMENTS ARE NEEDED AT THIS TIME.
820 PM UPDATE...
EARLIER SNOWS THAT WARRANTED THE ISSUANCE OF A QUICK WINTER WX
ADVISORY HAVE PUSHED EAST AND CONTINUE TO EXIT THE FORECAST AREA
STAGE RIGHT. UPSTREAM RADAR TRENDS FROM KBUF CONTINUE TO SHOW A
HEALTHY LAKE ERIE BAND WHICH HAS LED TO OVER A FOOT OF SNOW IN
LESS THAN 4 HOURS ACROSS PORTIONS OF CHAUTAUQUA COUNTY EARLIER
THIS EVENING. FORTUNATELY...THIS BAND WILL ONLY IMPACT PORTIONS OF
STEUBEN AND YATES COUNTIES WITH ACCUMULATIONS ACROSS THESE AREAS
LIKELY REMAINING BELOW ADVISORY THRESHOLDS. MAIN CONCERN THROUGH
THE REMAINDER OF THE OVERNIGHT CONTINUES TO BE DEVELOPING LAKE
SNOWS EAST OF LAKE ONTARIO AND POTENTIAL IMPACTS ACROSS PORTIONS
OF ONEIDA COUNTY. LATEST HIGH-RES MODEL SUITE CONTINUES TO SHOW
SOLID BAND ORGANIZATION AFTER THE 06Z TIME FRAME AS WESTERLY FLOW
BECOMES ALIGNED WITH THE LONG AXIS OF LAKE ONTARIO. QUICK LOOK AT
THE MOST RECENT 00Z BUF SOUNDING REVEALS MIXED LAYER HEIGHTS UP TO
ROUGHLY 14 KFT WITH MANUAL SKEW-T ADJUSTMENTS FOR CURRENT LAKE
TEMPS YIELDING CAPE VALUES IN EXCESS OF 500 J/KG. THIS COMBINED
850-MB TEMPS NEAR OF NEAR -20C WILL SET THE STAGE FOR WHAT SHOULD
BE A BONAFIDE SINGLE LAKE EFFECT BAND THROUGH THE EARLY MORNING
WITH THIS FEATURE THEN PERSISTING FOR MUCH OF THE DAY ON TUESDAY.
MAIN QUESTION CONTINUES TO BE JUST HOW FAR SOUTH THIS BAND WILL GO
AS CURRENT HIGH-RES MODELS SUGGEST BAND WILL OSCILLATE QUITE A BIT
THROUGH THE DAY WHICH MAY BE A RESULT OF EXTREME INSTABILITY IN
THE MIXED LAYER AND POTENTIAL CONVECTIVE OVERTURNING. THIS RAISES
OUR SUSPICIONS THAT SOUTHERN ONEIDA COUNTY MAY ALSO GET A FAIRLY
HEALTHY DOSE OF FRESH SNOW AS THE EVENT PROGRESSES AND FUTURE
FORECAST UPDATES MAY HAVE TO CONSIDER A SOUTHWARD EXTENSION TO THE
CURRENT LAKE EFFECT SNOW WARNING.
ELSEWHERE TONIGHT...EXPECT PASSING LIGHT SNOW SHOWERS FROM TIME TO
TIME WITH LITTLE TO NO ADDITIONAL ACCUMULATIONS ACROSS THE FINGER
LAKES AND POINTS SOUTH. TEMPS WILL CONTINUE TO FALL INTO THE
LOWER TO MIDDLE TEENS FOR OVERNIGHT LOWS.
450 PM UPDATE...
HAVE HOISTED A QUICK WINTER WX ADVISORY FROM THE CENTRAL SOUTHERN
TIER NORTHEAST THROUGH THE FINGER LAKES AND UPPER SUSQUEHANNA
VALLEY REGIONS AS A NOTABLE LOW-LEVEL CONVERGENT SIGNATURE AS
NOTED IN THE LATEST MSLP FIELD IS LEADING TO AN IMPRESSIVE LINEAR
SNOW BAND. HAVE RECEIVED MULTIPLE 3 TO 5 INCH REPORTS ACROSS THE
CENTRAL FINGER LAKES REGION AND BASED ON LATEST RR FORECASTS FROM
THE SPC MESO PAGE...WE EXPECT THIS LOW-LEVEL CONVERGENCE REGION
TO REMAIN IN PLACE FOR A FEW MORE HRS BEFORE FINALLY WINDING DOWN
AFTER 00Z. BASED ON THIS...HAVE INCREASED SNOWFALL TOTALS ACROSS
THE REGION WITH 4 TO 6 INCHES POSSIBLE FOR AREAS IN CLOSE
PROXIMITY TO THE LOW-LEVEL CONVERGENT MAXIMUM. NO OTHER CHANGES
NEEDED AT THIS TIME.
PREVIOUS NEAR TERM DISCUSSION...
FCST AREA WILL REMAIN UNDER NW FLOW ALOFT WITH A FEW EMBEDDED
S/WV`S TRAVERSING THE RGN. 1ST ONE IS CRNTLY AFFECTING THE FCST
AREA WITH AREAS OF LGT SNOW...AND 2ND ONE IS FCST TO MOVE INTO THE
RGN ON WED NGT. A MEANDERING FNTL BNDRY AND LES INFLUENCES WILL
CONTINUE TO MODULATE THE SHSN ACTIVITY ACRS THE FCST AREA INTO MID
WEEK.
LATER TNGT AS THE 1ST WAVE DEPARTS...LOW LVL FLOW WILL BCM WRLY
AND FOCUS LES EFFECTS INTO NRN ONEIDA COUNTY AS 850 TEMPS DROPS
TO ARND -20C. LOW LVL 270 FLOW BCMS ALIGNED BY 06Z. HIGH INVERSION
LVL (10K FT)...ALIGNED FLOW AND GOOD SNOW GROWTH PROFILE. CRNT
FCST HAS ACCUMS OF 6-10 INCHES PRIMARILY NEAR THE OSWEGO/LEWIS
COUNTY BORDER. BOTTOM LINE IS THAT SRN PERIPHERY OF THIS BAND IS
XPCTD TO BE OVER NRN ONEIDA WITH LOW END WARNING ACCUMS. THIS BAND
IS FCST TO DROP SWD LATE TUE AFTN INTO NRN ONON/MAD/SRN ONEIDA/NRN
OTSEGO.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
LES BAND XPCTD TO MEANDER ACRS FAVORED 290-300 FLOW REGIONS INTO
WED MRNG...WHICH MAY BE ENHANCED BY LOW LVL CONVERGENCE ASSCD WITH
SAGGING ARCTIC BNDRY. THIS ACTIVITY SHUD WEAKEN BY WED AFTN.
PROFILES STILL LOOKING GOOD DURING THIS TIME FRAME...AS INVERSION
LVL REMAINS HIGH AT 9-10 K FT AND LOW LVL FLOW REMAINS ALIGNED
ARND 300 DEG...THEN THE INVERSION LOWERS AND FLOW WEAKENS BY WED
AFTN. INITIAL THOUGHTS ARE THAT WE`LL NEED LES ADVISORIES FOR THIS
TIME PERIOD. WE`LL DEFER ON THE POTNL HEADLINES ATTM...AND LET THE
EVNG/MID SHIFTS RE-ASSESS. HAVE MENTIONED POTNL IN THE UPDATED
HWO. OUTSIDE THE MAIN LES AREAS...SLGT CHC TO LOW CHC POPS...WITH
POTNL FOR LAKE ERIE ACTIVITY TO CUT ACRS PORTIONS OF THE SRN TIER
AND NE PA.
CONCERNING WIND CHILLS...GIVEN CRNT FCST TEMPS AND WINDS WE DO NOT
SHOW ANY VALUES BLO -15 UNTIL TMRW NGT ACRS ONEIDA COUNTY. PSBL
THAT A FEW OTHER LOCATIONS COULD APRCH VALUES. LATER SHIFTS CAN
RE-EVALUATE THIS.
ON WED XPCT LES ACTIVITY TO DIMINISH BUT APRCHNG S/WV COULD RESULT
IN DVLPMNT OF MORE --SHSN AS THE DAY PROGRESSES SO WE CONTINUE
WITH CHC POPS MOST LOCATIONS. BEST CHC FOR A DRY DAY WILL BE
THURSDAY AS SFC HIGH IS XPCTD TO CREST OVER THE RGN LATE IN THE
DAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MODELS SIMILAR. GRIDS LOOK GOOD. LITTLE CHANGE.
PREVIOUS DISCUSSION...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED.
INITIALLY A SOUTHERN STREAM SYSTEM WILL TRACK THROUGH THE MID
ATLANTIC REGION ON FRIDAY. THE ECMWF/CANADIAN IS MUCH FASTER THAN
THE GFS, LEANED TOWARD THE ECMWF ENSEMBLE WHICH IS A GOOD
COMPROMISE. THURSDAY NIGHT BACKED OFF ON POPS TO JUST CHC THEN
CHC/LIKELY ON FRIDAY WITH LIKELY POPS ACROSS THE SOUTHERN TIER AND
NE PA. MODELS INDICATE ALL SNOW WITH NO HINT OF ANY WARM LAYER.
BEHIND THIS WAVE THE UPPER LEVEL TROF WILL AMPLIFY OVER THE
NORTHEAST MAKING FOR A COLD WEEKEND WITH SCATTERED SNOW SHOWERS IN
NORTH/NORTHWEST FLOW. BY SUNDAY/MONDAY, UPPER LEVEL HEIGHTS RISE
WITH THE AIRMASS EXPECTED TO MODIFY UNDER SOUTHWEST FLOW.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
1230 AM UPDATE...
A SHORTWAVE GOING THROUGH NOW HAS PUSHED IFR SNOW SHOWERS THROUGH
BGM ITH AND SYR. THESE HAVE ENDED THERE. RME WILL HAVE IFR VSBYS
AND MAYBE CIGS FOR AN HOUR OR TWO BEFORE LIFTING NORTH OF THEM. A
SINGLE BAND OF LAKE EFFECT OFF OF LAKE ONTARIO WILL SET UP IN
OSWEGO AND LEWIS COUNTIES. THIS BAND WILL DROP SOUTH INTO RME
AROUND 12Z AND REMAIN MOST OF THE DAY. RME WILL HAVE IFR
CONDITIONS AND ALTERNATE MINIMUM. THE BAND WILL DROP FURTHER SOUTH
TO SYR MIDDAY AGAIN WITH IFR CONDITIONS AND BELOW ALTERNATE
MINIMUM.
WITH THIS WSW FLOW THE REST OF THE TAF SITES SHOULD BE MOSTLY VFR
AND FAR ENOUGH AWAY FROM LAKE ERIE TO CAUSE REDUCTIONS. EXCEPTION
IS KAVP AS THE SNOW THAT WENT THROUGH ITH AND BGM DROPS SOUTH.
SOME MVFR POSSIBLE THERE 8 TO 12Z.
WEST WINDS AROUND 10 KTS EARLY THIS MORNING. INCREASING TO 10 TO
15 KTS WITH GUSTS TO 25 KTS DURING THE DAY. WINDS DROPPING TO 10
KTS AT 23Z.
.OUTLOOK...
TUE NIGHT THRU WED...MVFR/IFR IN SNOW SHOWERS FOR KRME/KSYR
OTHERWISE PRIMARILY VFR.
THURSDAY/THURSDAY NIGHT...PRIMARILY VFR.
FRI... IFR CONDITIONS POSSIBLE IN SNOW.
FRIDAY NIGHT/SATURDAY...MVFR SNOW SHOWERS RESTRICTIONS LIKELY FOR
CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WATCH FROM 10 AM EST THIS MORNING THROUGH
WEDNESDAY MORNING FOR NYZ018-036.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST WEDNESDAY FOR NYZ009-
037.
&&
$$
SYNOPSIS...
NEAR TERM...CMG/PVN
SHORT TERM...
LONG TERM...RRM/TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1226 AM EST TUE JAN 22 2013
.SYNOPSIS...
PERIODS OF LIGHT SNOW WILL CONTINUE OFF AND ON OVERNIGHT TONIGHT. COLDER
AIR WILL ARRIVE ON GUSTY WEST TO NORTHWEST WINDS LATER TONIGHT...WHICH
WILL ALLOW LAKE EFFECT SNOWS TO DEVELOP. THIS ACTIVITY WILL
DIMINISH ON THURSDAY AS HIGH PRESSURE BRIEFLY MOVES INTO THE AREA.
OUTSIDE OF THE LAKE EFFECT SNOW...PARTLY TO MOSTLY CLOUDY SKIES
AND SCATTERED SNOW SHOWERS OR FLURRIES ARE EXPECTED.
&&
.NEAR TERM /THROUGH TODAY/...
1220 AM UPDATE...
QUICK UPDATE TO GRIDS TO ACCNT FOR MODERATE TO HVY SNOW OVR NRN
ONONDAGA CNTY WITH 1-2.5 INCH PER HR AMNTS. THANKFULLY THIS SNOW
IS MVG QUICKLY INTO ONEIDA CNTY ATTM, THUS NO CHGS TO HEADLINES
NEEDED. ANOTHER BATCH OF SNOW IS MVG THRU THE TWIN TIERS DUE TO
LES OFF OF LK ERIE. EXPECT THIS TO CONTINUE FOR THE NEXT 1-2 HRS
AND HV INCRSD POPS TO LKLY TO ACCNT FOR THIS ACTIVITY AS IT HEADS
EAST. EXPECTING A QUICK HALF INCH TO ONE INCH OF SNOW WITH THESE
SNOW SHOWERS AS THEY PASS THRU THE REGION.
1020 PM UPDATE...
LATEST HIGH-RES MODELS CONTINUE TO ADVERTISE LAKE BAND DEVELOPMENT
EAST OF LAKE ONTARIO THIS EVENING WITH RECENT RADAR TRENDS FROM BOTH
KBUF AND KTYX NOW SHOWING THE INITIAL STAGES OF BAND DEVELOPMENT.
THAT SAID...WE HAVE ELECTED TO EXTEND THE LAKE EFFECT SNOW WARNING
SOUTH TO INCLUDE ALL ONEIDA COUNTY BEGINNING AT 06Z THIS EVENING.
CONSIDERING THE BANDS ARE FORECAST BY HIGH-RES MODELS TO EXTEND
SOUTH INTO ONONDAGA AND MADISON COUNTIES...HAVE POSTED A LAKE
EFFECT SNOW WATCH FOR ZONES BEGINNING AT 15Z TUE WHERE 5 TO 9
INCHES OF NEW SNOW WILL BE POSSIBLE THROUGH TUE NIGHT. AS STATED
IN THE PREVIOUS UPDATE...MODELS CONTINUE TO SHOW A FAIR AMOUNT OF
BAND MOVEMENT DURING THE DAYLIGHT HOURS WHICH MAY BE A
MANIFESTATION OF CONVECTIVE OVERTURNING DUE TO A STRONGLY UNSTABLE
MIXED LAYER. ONCE THE BAND DOES FORM...WE EXPECT THE FEATURE TO BE
FAIRLY INTENSE WITH HOURLY SNOWFALL RATES OF 1-2"/HR DEFINITELY A
POSSIBILITY CONSIDERING HIGH INVERSION LEVELS (>14 KFT) AND STRONG
INSTABILITY. ELSEWHERE...EVERYTHING REMAINS ON TRACK AND NO MAJOR
ADJUSTMENTS ARE NEEDED AT THIS TIME.
820 PM UPDATE...
EARLIER SNOWS THAT WARRANTED THE ISSUANCE OF A QUICK WINTER WX
ADVISORY HAVE PUSHED EAST AND CONTINUE TO EXIT THE FORECAST AREA
STAGE RIGHT. UPSTREAM RADAR TRENDS FROM KBUF CONTINUE TO SHOW A
HEALTHY LAKE ERIE BAND WHICH HAS LED TO OVER A FOOT OF SNOW IN
LESS THAN 4 HOURS ACROSS PORTIONS OF CHAUTAUQUA COUNTY EARLIER
THIS EVENING. FORTUNATELY...THIS BAND WILL ONLY IMPACT PORTIONS OF
STEUBEN AND YATES COUNTIES WITH ACCUMULATIONS ACROSS THESE AREAS
LIKELY REMAINING BELOW ADVISORY THRESHOLDS. MAIN CONCERN THROUGH
THE REMAINDER OF THE OVERNIGHT CONTINUES TO BE DEVELOPING LAKE
SNOWS EAST OF LAKE ONTARIO AND POTENTIAL IMPACTS ACROSS PORTIONS
OF ONEIDA COUNTY. LATEST HIGH-RES MODEL SUITE CONTINUES TO SHOW
SOLID BAND ORGANIZATION AFTER THE 06Z TIME FRAME AS WESTERLY FLOW
BECOMES ALIGNED WITH THE LONG AXIS OF LAKE ONTARIO. QUICK LOOK AT
THE MOST RECENT 00Z BUF SOUNDING REVEALS MIXED LAYER HEIGHTS UP TO
ROUGHLY 14 KFT WITH MANUAL SKEW-T ADJUSTMENTS FOR CURRENT LAKE
TEMPS YIELDING CAPE VALUES IN EXCESS OF 500 J/KG. THIS COMBINED
850-MB TEMPS NEAR OF NEAR -20C WILL SET THE STAGE FOR WHAT SHOULD
BE A BONAFIDE SINGLE LAKE EFFECT BAND THROUGH THE EARLY MORNING
WITH THIS FEATURE THEN PERSISTING FOR MUCH OF THE DAY ON TUESDAY.
MAIN QUESTION CONTINUES TO BE JUST HOW FAR SOUTH THIS BAND WILL GO
AS CURRENT HIGH-RES MODELS SUGGEST BAND WILL OSCILLATE QUITE A BIT
THROUGH THE DAY WHICH MAY BE A RESULT OF EXTREME INSTABILITY IN
THE MIXED LAYER AND POTENTIAL CONVECTIVE OVERTURNING. THIS RAISES
OUR SUSPICIONS THAT SOUTHERN ONEIDA COUNTY MAY ALSO GET A FAIRLY
HEALTHY DOSE OF FRESH SNOW AS THE EVENT PROGRESSES AND FUTURE
FORECAST UPDATES MAY HAVE TO CONSIDER A SOUTHWARD EXTENSION TO THE
CURRENT LAKE EFFECT SNOW WARNING.
ELSEWHERE TONIGHT...EXPECT PASSING LIGHT SNOW SHOWERS FROM TIME TO
TIME WITH LITTLE TO NO ADDITIONAL ACCUMULATIONS ACROSS THE FINGER
LAKES AND POINTS SOUTH. TEMPS WILL CONTINUE TO FALL INTO THE
LOWER TO MIDDLE TEENS FOR OVERNIGHT LOWS.
450 PM UPDATE...
HAVE HOISTED A QUICK WINTER WX ADVISORY FROM THE CENTRAL SOUTHERN
TIER NORTHEAST THROUGH THE FINGER LAKES AND UPPER SUSQUEHANNA
VALLEY REGIONS AS A NOTABLE LOW-LEVEL CONVERGENT SIGNATURE AS
NOTED IN THE LATEST MSLP FIELD IS LEADING TO AN IMPRESSIVE LINEAR
SNOW BAND. HAVE RECEIVED MULTIPLE 3 TO 5 INCH REPORTS ACROSS THE
CENTRAL FINGER LAKES REGION AND BASED ON LATEST RR FORECASTS FROM
THE SPC MESO PAGE...WE EXPECT THIS LOW-LEVEL CONVERGENCE REGION
TO REMAIN IN PLACE FOR A FEW MORE HRS BEFORE FINALLY WINDING DOWN
AFTER 00Z. BASED ON THIS...HAVE INCREASED SNOWFALL TOTALS ACROSS
THE REGION WITH 4 TO 6 INCHES POSSIBLE FOR AREAS IN CLOSE PROXIMITY
TO THE LOW-LEVEL CONVERGENT MAXIMUM. NO OTHER CHANGES NEEDED AT
THIS TIME.
PREVIOUS NEAR TERM DISCUSSION...
FCST AREA WILL REMAIN UNDER NW FLOW ALOFT WITH A FEW EMBEDDED
S/WV`S TRAVERSING THE RGN. 1ST ONE IS CRNTLY AFFECTING THE FCST
AREA WITH AREAS OF LGT SNOW...AND 2ND ONE IS FCST TO MOVE INTO THE
RGN ON WED NGT. A MEANDERING FNTL BNDRY AND LES INFLUENCES WILL
CONTINUE TO MODULATE THE SHSN ACTIVITY ACRS THE FCST AREA INTO MID
WEEK.
LATER TNGT AS THE 1ST WAVE DEPARTS...LOW LVL FLOW WILL BCM WRLY AND
FOCUS LES EFFECTS INTO NRN ONEIDA COUNTY AS 850 TEMPS DROPS TO ARND
-20C. LOW LVL 270 FLOW BCMS ALIGNED BY 06Z. HIGH INVERSION LVL
(10K FT)...ALIGNED FLOW AND GOOD SNOW GROWTH PROFILE. CRNT FCST
HAS ACCUMS OF 6-10 INCHES PRIMARILY NEAR THE OSWEGO/LEWIS COUNTY
BORDER. BOTTOM LINE IS THAT SRN PERIPHERY OF THIS BAND IS XPCTD TO
BE OVER NRN ONEIDA WITH LOW END WARNING ACCUMS. THIS BAND IS FCST
TO DROP SWD LATE TUE AFTN INTO NRN ONON/MAD/SRN ONEIDA/NRN OTSEGO.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
LES BAND XPCTD TO MEANDER ACRS FAVORED 290-300 FLOW REGIONS INTO
WED MRNG...WHICH MAY BE ENHANCED BY LOW LVL CONVERGENCE ASSCD WITH
SAGGING ARCTIC BNDRY. THIS ACTIVITY SHUD WEAKEN BY WED AFTN.
PROFILES STILL LOOKING GOOD DURING THIS TIME FRAME...AS INVERSION
LVL REMAINS HIGH AT 9-10 K FT AND LOW LVL FLOW REMAINS ALIGNED
ARND 300 DEG...THEN THE INVERSION LOWERS AND FLOW WEAKENS BY WED
AFTN. INITIAL THOUGHTS ARE THAT WE`LL NEED LES ADVISORIES FOR THIS
TIME PERIOD. WE`LL DEFER ON THE POTNL HEADLINES ATTM...AND LET THE
EVNG/MID SHIFTS RE-ASSESS. HAVE MENTIONED POTNL IN THE UPDATED
HWO. OUTSIDE THE MAIN LES AREAS...SLGT CHC TO LOW CHC POPS...WITH
POTNL FOR LAKE ERIE ACTIVITY TO CUT ACRS PORTIONS OF THE SRN TIER
AND NE PA.
CONCERNING WIND CHILLS...GIVEN CRNT FCST TEMPS AND WINDS WE DO NOT
SHOW ANY VALUES BLO -15 UNTIL TMRW NGT ACRS ONEIDA COUNTY. PSBL
THAT A FEW OTHER LOCATIONS COULD APRCH VALUES. LATER SHIFTS CAN
RE-EVALUATE THIS.
ON WED XPCT LES ACTIVITY TO DIMINISH BUT APRCHNG S/WV COULD RESULT
IN DVLPMNT OF MORE --SHSN AS THE DAY PROGRESSES SO WE CONTINUE
WITH CHC POPS MOST LOCATIONS. BEST CHC FOR A DRY DAY WILL BE
THURSDAY AS SFC HIGH IS XPCTD TO CREST OVER THE RGN LATE IN THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED.
INITIALLY A SOUTHERN STREAM SYSTEM WILL TRACK THROUGH THE MID
ATLANTIC REGION ON FRIDAY. THE ECMWF/CANADIAN IS MUCH FASTER THAN
THE GFS, LEANED TOWARD THE ECMWF ENSEMBLE WHICH IS A GOOD
COMPROMISE. THURSDAY NIGHT BACKED OFF ON POPS TO JUST CHC THEN
CHC/LIKELY ON FRIDAY WITH LIKELY POPS ACROSS THE SOUTHERN TIER AND
NE PA. MODELS INDICATE ALL SNOW WITH NO HINT OF ANY WARM LAYER.
BEHIND THIS WAVE THE UPPER LEVEL TROF WILL AMPLIFY OVER THE
NORTHEAST MAKING FOR A COLD WEEKEND WITH SCATTERED SNOW SHOWERS IN
NORTH/NORTHWEST FLOW. BY SUNDAY/MONDAY, UPPER LEVEL HEIGHTS RISE
WITH THE AIRMASS EXPECTED TO MODIFY UNDER SOUTHWEST FLOW.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL DISTURBANCE AND ITS ASSOCIATED WEAK SFC FEATURE
WILL TRACK ACROSS CENTRAL PA LATE THIS AFTERNOON THROUGH THE EARLY
EVENING. THIS SYSTEM WILL PRODUCE WIDESPREAD MVFR CONDITIONS IN LIGHT
SNOW ACROSS ALL OF THE TERMINALS THIS AFTERNOON THROUGH THE EARLY
EVENING PERIOD. ACROSS THE SOUTHERN TERMINALS IFR CONDITIONS ARE
POSSIBLE BETWEEN 18Z-00Z, BUT MOST LIKELY AT KBGM/KAVP. BEHIND
THIS WAVE NORTHWEST FLOW WILL DEVELOP KEEPING PRIMARILY MVFR
CONDITIONS ACROSS THE REGION THROUGH 06Z WITH SCATTERED FLURRIES
AND SNOW SHOWERS. AFTER 06Z CONDITIONS WILL BE PRIMARILY VFR WITH
SOUTHWEST WINDS DEVELOPING. THE LAKE EFFECT SNOW IS EXPECTED TO
REMAIN NORTH OF THE KRME/KSYR TERMINALS THROUGH 18Z BUT AFTER 18Z
IT IS EXPECTED TO AFFECT THE AIRPORTS WITH IFR CONDITIONS LIKELY.
SOUTHWEST WINDS AROUND 5 KNOTS OT LIGHT AND VARIABLE BECOMING
NORTHWEST THIS EVENING AROUND 10 KNOTS SHIFTING TO THE SOUTHWEST
TOWARD DAYBREAK AND INCREASING TO 12-15 KNOTS WITH GUSTS AROUND 25
KNOTS.
.OUTLOOK...
TUE NIGHT THRU WED...MVFR/IFR IN SNOW SHOWERS FOR KRME/KSYR
OTHERWISE PRIMARILY VFR.
THURSDAY/THURSDAY NIGHT...PRIMARILY VFR.
FRI... IFR CONDITIONS POSSIBLE IN SNOW.
FRIDAY NIGHT/SATURDAY...MVFR SNOW SHOWERS RESTRICTIONS LIKELY FOR
CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WATCH FROM 10 AM EST THIS MORNING THROUGH
WEDNESDAY MORNING FOR NYZ018-036.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST WEDNESDAY FOR NYZ009-
037.
&&
$$
SYNOPSIS...PVN
NEAR TERM...CMG/PVN
SHORT TERM...
LONG TERM...RRM
AVIATION...MLJ/RRM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1212 AM EST TUE JAN 22 2013
.SYNOPSIS...
ARCTIC AIR WILL POUR INTO CENTRAL PENNSYLVANIA TONIGHT BEHIND A
CLIPPER SYSTEM...PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS AND
A FEW SQUALLS. LAKE EFFECT SNOW WILL PRODUCE SEVERAL INCHES OF
ACCUMULATION OVER THE FAR NORTHWEST...WHILE WIND CHILLS WILL DROP
BELOW 15 BELOW ZERO OVER THE LAUREL HIGHLANDS LATER TONIGHT.
THE SURGE OF ARCTIC AIR WILL LAST THROUGH MID WEEK. LAKE EFFECT
SNOW SHOWERS WILL CONTINUE INTO TUESDAY EVENING BEFORE DECREASING.
A LOW PRESSURE SYSTEM WILL TRACK FROM THE SOUTHERN PLAINS TO THE
MID ATLANTIC COAST LATE IN THE WEEK BRINGING A CHANCE OF SNOW
TO MOST OF THE AREA.
&&
.NEAR TERM /UNTIL 8 AM TUESDAY MORNING/...
BIG OL LES BAND PARALLEL TO THE LAKE SHORE LINE IS BREAKING UP AS
THE FLOW IN THE LOWEST 5-10KFT BECOMES MORE NWRLY. THE PROGS
FROM THE NAM/RUC AND HRRR STILL POINT TO THIS BAND/AREA CONTINUING
TO SLIDE ESE AND PIVOT TO BE MORE WEST-EAST BEFORE FIZZLING AS IT
NEARS I-80. THE TRANSITORY NATURE SHOULD KEEP ACCUMS IN THE RANGE
WE HAVE GOING. FETCH IS ALL VERY FAVORABLE FOR SNOW TO PILE UP
OVER WARREN COUNTY AND ALSO ACCUMULATE ACROSS THE REST OF THE
NW/NRN MTS. CONSIDERED A BUMP TO LES WARNING FOR WARREN COUNTY
/AND PERHAPS ADVY IN MCKEAN CO/ WITH SOME HIGHER THAN 8 INCH
ACCUMS POSS IN THE NW SNOW BELT AND N OF ROUTE 6. BUT DECIDED TO
HOLD THE COURSE SINCE THERE HAS BEEN LITTLE SNOW IN WARREN COUNTY
THROUGH THE DAY. NEW NAM AND OTHER MESO MDLS ALSO HOLD NO BIG
REVELATIONS.
THE UPSLOPE FLOW IS ABOUT THE ONLY THING GOING FOR SNOW ACCUMS IN
THE LAURELS. LOTS OF LARGE BREAKS IN THE CLOUDS NOW...BUT IT TOO
SHOULD TREND TOWARD A CLIMO LOOK AS THE FLOW BECOMES WNW.
THE ARCTIC AIR HAS ALREADY BROUGHT TEMPS DOWN TO 10F IN THE WRN
MTS...AND WIND CHILLS ARE BELOW ZERO THERE AS WELL. WINDS JUST
PICKED UP IN THE VALLEYS OF THE EAST...AND WILL STAY UP ALL
NIGHT ACROSS THE AREA - WITH THE HIGHEST SPEEDS IN THE MTS.
THUS...THE WIND CHILL ADVY IS SOLID...AND WILL REMAIN. SPOTTY -15F
WIND CHILLS MAY BE HAD IN THE NRN MTS...BUT CLOUDS AND SLIGHTLY
LOWER WIND SPEEDS THERE SHOULD KEEP COUNTY-WIDE AREAS OF -15 FROM
OCCURRING. THIS IS ALREADY THE COLDEST NIGHT OF THE SEASON FOR
MOST OF PENNSYLVANIA.
&&
.SHORT TERM /8 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE UPPER TROF SWINGS ACROSS PA TONIGHT AND EARLY TUESDAY. A WELL
MIXED BLYR SHOULD ALLOW 25-30KT GUSTS TO MIX TO THE SFC
TUESDAY...PERSISTING THROUGHOUT THE DAY WITH WIND CHILLS REMAINING
BELOW ZERO FOR MUCH OF THE REGION. WIND CHILL ADVISORY WILL REMAIN
IN EFFECT OVER THE LAURELS THROUGHOUT THE DAY. ENS MEAN 850MB
TEMPS ARND -21C SHOULD TRANSLATE TO HIGHS ONLY NEAR 10F ACROSS THE
ALLEGHENY MTNS AND AROUND 20F ACROSS THE SUSQ VALLEY.
REGARDING LAKE EFFECT SNOW ADVISORY...BOUNDARY LAYER FLOW OF ARND
280 DEGREES WOULD PRECLUDE ANY HURON CONNECTION OR LONG FETCH WITH
THE HEAVIEST BANDS AND ACCUMS STAYING JUST NORTH OF MY AREA.
STILL...THE NEXT 24 HRS COULD HOLD 8 INCHES ACROSS NORTHWESTERN
WARREN COUNTY. A SLIGHT SOUTHWARD SHIFT IN BANDS COULD ALWAYS
OCCUR...AND WILL BE MONITORED. 20/1 RATIOS PRODUCE 6-8 INCHES OVER
THE SNOWBELT OF NW WARREN COUNTY BTWN THIS AFTN AND TUE EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
SOME SNOW SHOWERS WILL BE ACROSS NORTHERN AND WESTERN AREAS
TUE NIGHT AND WED...GIVEN NW FLOW OF COLD AIR.
MODELS HINT THAT ACTIVITY COULD BE A LITTLE MORE ACTIVE ON
WED...AS JET MAX MOVES ACROSS THE AREA.
DID NOT RUSH TO TAPER ACTIVITY WED NIGHT...GIVEN HOW COLD
THE AIRMASS IS.
THU WILL BE THE BEST DAY.
LEFT AMTS CLOSE TO WHAT WAS IN GRIDS FOR NEXT MODERATE
SNOW EVENT. YESTERDAY...MODELS WERE A LITTLE FASTER WITH
THE SYSTEM...TODAY THEY ARE SLOWER...SO MADE SOME TIMING
ADJUSTMENTS.
DID PUT SOME SLEET BACK IN...BUT JUST THE FAR SOUTH...GIVEN
POTENTIAL FOR SOME MID LVL WARMING. SYSTEM DOES NOT HAVE A
LOT OF GULF MOISTURE TO WORK WITH...BUT STRONG WARM ADVECTION
MAY AID IN BRIEF HEAVIER BURST OF SNOW.
MORE COLD AND SNOW SHOWERS FOR THE FIRST PART OF THE WEEKEND.
TEMPS MODERATE SOME FOR LATER SUNDAY INTO MONDAY.
SPEAKING OF TEMPS...COMBINATION OF WIND AND COLD SUPPORT
WIND CHILLS IN THE ADVISORY RANGE.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
BANDS OF SNOW SHOWERS AND ACCOMPANYING GUSTY WINDS CONTINUE TO CAUSE
MVFR/OCNL IFR CIGS AND VSBYS ACROSS THE NORTH EASTERN AREAS.
BANDS OF HEAVIER SNOW SHOWERS AND A FEW SQUALLS WILL ACCOMPANY LOW
PRESSURE AND ITS ASSOCIATED COLD FRONT MAINLY THROUGH THE NW MTNS.
MUCH COLDER AIR WILL MOVE IN OVERNIGHT WITH /-20C AT 850MB/. MOISTURE
AGAIN WILL BE LIMITED WHICH WILL KEEP CIG/VSBY REDUCTIONS AND SNOW
IMPACTS CONFINED MAINLY TO HIGHER TERRAIN IN THE WEST. COLD FLOW
ACROSS MUCH WARMER LAKES WILL BRING LOWER CLOUDS INTO KBFD-KJST
STARTING LATE TUESDAY MORNING AND ENHANCE SNOW POTENTIAL IN THOSE
SAME AREAS. BIGGEST SNOWFALL WILL BE CONFINED CLOSER TO LAKE
ERIE...BUT LIGHTER INTERMITTANT BANDED SNOWS WILL IMPACT KBFD-KJST
FOR NEXT COUPLE OF DAYS AS PERSISTENT NW FLOW ESTABLISHES ITSELF.
OCNL ENCROACHMENT OF MVFR POSS INTO CENTRAL MTNS...WHILE DOWNSLOPE
FLOW KEEPS WEATHER VFR IN THE EAST.
WINDS WILL PICK BACK UP TODAY A BIT...ESPECIALLY OVER WESTERN
HIGHER TERRAIN WHERE GUSTS TO 20-30 MPH WILL AGAIN BECOME COMMON.
OUTLOOK...
TUE-THU AM...SHSN WITH MVFR/OCNL IFR W MTNS...SCT/LIKELY SHSN IN
MVFR CENTRAL MTNS...SCT SHSN AND PRIMARILY VFR SE.
THU PM-FRI...MVFR/IFR POSSIBLE LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR PAZ004.
WIND CHILL ADVISORY UNTIL 1 PM EST WEDNESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1008 PM MST MON JAN 21 2013
.AVIATION...06Z TAF FORECASTS
SNOW FLURRIES ON THE WESTERN SD PLAINS WILL GRADUALLY SHIFT EAST
AND TAPER OFF OVERNIGHT. AREAS OF MVFR CIGS OVER WESTERN SOUTH
DAKOTA WILL IMPROVE TO VFR TUESDAY MORNING.
&&
PREV DISCUSSION... /ISSUED 431 PM MST MON JAN 21 2013/
DISCUSSION...21Z SURFACE ANALYSIS HAD WARM FRONT FROM CENTRAL MT
INTO WESTERN NE. LIFT ALONG 140KT JET STREAK ON COLD SIDE OF WARM
FRONT CONTINUING TO PRODUCE -SN OVER WESTERN SD PER KUDX RADAR.
12Z GUIDANCE AS WELL AS 18Z RAP SHOW ACTIVITY WANING AND SLOWLY
MOVING EAST TONIGHT. MOST ACTIVITY SHOULD EXIT CWA BY 12Z TUESDAY.
ACCUMULATIONS WILL CONTINUE TO BE MINOR. TEMPERATURES NEAR
GUIDANCE LOOK REASONABLE.
TUESDAY...UPPER RIDGE BUILDS EAST INTO THE ROCKIES AS SURFACE WARM
FRONT WORKS ACROSS WESTERN SD. HOW FAR EAST IT GOES IT THE MAIN
QUESTION...BUT IT SHOULD AT LEAST MAKE IT TO A K2WX TO KVTN LINE.
BEHIND IT TEMPERATURES SHOULD REACH WELL INTO THE 30S TO LOWER 40S
GIVEN FORECAST LOWER TROPOSPHERIC PROFILES.
WEDNESDAY...UPPER RIDGE MOVES OVER THE NORTHERN PLAINS AND
DEAMPLIFIES AS SHORTWAVE TROUGHS MOVES INTO THE NORTHERN ROCKIES.
INITIAL TROUGH/COOL FRONT WILL SLIDE INTO THE CWA. TEMPERATURES
SHOULD ROCKET INTO THE 40S OVER WY/HIGHER ELEVATIONS...BUT AS AN
EASTERLY COMPONENT TO THE SURFACE WIND DEVELOPS ON THE SD PLAINS
BY AFTERNOON...EXPECT TEMPERATURES RISES TO BE HALTED MAINLY IN
THE 20S. ST/BR MAY DEVELOP WEDNESDAY NIGHT GIVEN WEAK UPSLOPE FLOW
AHEAD OF NEXT FRONT FOR THURSDAY.
EXTENDED...A FAST MOVING CLIPPER SYSTEM WILL MOVE THROUGH THE NRN
PLAINS ON THURSDAY...BRINGING GUSTY NORTHWEST WINDS ALONG WITH
CHANCES FOR PRECIP MAINLY OVER THE NRN CWA. RIDGE OVER THE WRN CONUS
WILL THEN SLOWLY SHIFT EAST...BRINGING MILD AND DRY CONDITIONS FOR
THE WEEKEND. MODELS START TO DIVERGE ON A SOLUTION TO START NEXT
WEEK THOUGH OVERALL PATTERN REMAINS UNSETTLED...SO WILL LEAVE LOW
POPS IN FOR NOW.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
420 AM EST TUE JAN 22 2013
.SYNOPSIS...
HIGH PRESSURE WITH VERY COLD AIR WILL COVER THE AREA TODAY AND
WEDNESDAY. A LOW PRESSURE SYSTEM WILL MOVE FROM THE PLAINS ON
THURSDAY INTO THE OHIO VALLEY AND MID ATLANTIC REGION ON FRIDAY.
HIGH PRESSURE AND MORE COLD AIR IS EXPECTED SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM EST TUESDAY...
A COUPLE OF WEAK SHORT WAVES AND STRING UPSLOPE IN EASTERN WET
VIRGINIA HAVE SQUEEZED ENOUGH LOW LEVEL MOISTURE OUT OF THIS
ARCTIC AIRMASS FOR LOW CLOUDS ALONG THE WESTERN SLOPES OF THE
MOUNTAINS FROM GREENBRIER COUNTY NORTH INTO CENTRAL PENNSYLVANIA.
AREA NATIONAL WEATHER SERVICE RADARS SHOWED ONLY MINIMAL SHOW
SHOWER COVERAGE IN SOUTHEAST WEST VIRGINIA.
SUBTLE SHORT WAVES WILL CONTINUE TO ROTATE THROUGH THE LONG WAVE
THROUGH TODAY AND TONIGHT. THE RUC AND OOZE WRF SUGGEST THE LOWER
CLOUDS MAY EXPAND SOUTH TO BLUEFIELD AND TAZEWELL COUNTY THIS
MORNING. OTHERWISE AS A JET STREAK CROSSES THE FORECAST AREA
EXPECT MOUNTAIN CIRRUS ON THE EAST SLOPES OF THE CENTRAL AND
SOUTHERN APPALACHIANS THIS EVENING. HAVE ADJUSTED CLOUD COVER
FORECAST FOR THESE TRENDS.
AIR MASS UPSTREAM AT 00Z HAD 850 MB TEMPERATURES FROM -15 TO -20
AND SURFACE DEW POINTS WELL BELOW ZERO. HAVE GONE COLDER THAN
GUIDANCE FOR BOTH HIGHS TODAY AND LOWS TONIGHT.
SURFACE PRESSURE CONTINUES TO RISE TODAY AND BY WEDNESDAY MORNING
THE CENTER OF THE HIGH WILL BE OVER EASTERN TENNESSEE. WIND WILL
BEGIN TO DIMINISH THIS MORNING AND WILL BE MUCH LIGHTER IN THE
VALLEYS TONIGHT. AT THE HIGHER ELEVATIONS OF BATH...GREENBRIER AND
ALLEGHANY VIRGINIA...WIND CHILLS STAY CLOSE TO THE ZERO TO -5
RANGE DESPITE THE DECREASING WIND SPEEDS. HAVE EXTENDED THE WIND
CHILL ADVISORY IN THESE COUNTIES THROUGH WEDNESDAY MORNING.
ANOTHER ADVISORY MADE BE NEEDED FOR LATE TONIGHT FOR THE WESTERN
PART OF THE FORECAST AREA.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EST TUESDAY...
COMPLEX FORECAST FOR THE LATER HALF OF THE WEEK. ARCTIC AIR WILL BE
FIRMLY ENTRENCHED ACROSS THE FORECAST AREA EARLY WEDNESDAY MORNING.
UPPER TROUGH/POLAR VORTEX OVER ERN CANADA WILL MOVE VERY LITTLE FROM
WEDNESDAY THROUGH FRIDAY...ALTHOUGH WILL SEE BRIEF RETREAT OF
COLDEST AIR WEDNESDAY AND AGAIN FRIDAY AHEAD OF TWO SEPARATE SHORT
WAVES THAT WILL CROSS THE REGION DURING THIS TIME FRAME.
THE FIRST WAVE WILL MOVE THROUGH THE GREAT LAKES AND ALONG THE MASON-
DIXON WEDNESDAY NIGHT. THIS WILL CAUSE WINDS TO BACK WITH
DEVELOPMENT OF ISENTROPIC LIFT ACROSS THE OHIO VALLEY WEDNESDAY...
THIS AREA OF FORCING SCOOTING BY TO OUR NORTH WEDNESDAY NIGHT. AT
THE VERY LEAST SHOULD SEE INCREASING CLOUDINESS WEDNESDAY...CLOUDS
THICKENING PRIOR TO THE PASSAGE OF THE SHORTWAVE WEDNESDAY NIGHT. A
BRIEF PERIOD OF LIGHT SNOW OR FLURRIES IS POSSIBLE...BUT MAINLY FOR
THE WV MTNS AND VA HIGHLANDS. FORECAST BUFKIT SOUNDINGS INDICATE
LITTLE IN THE WAY OF PRECIP REACHING THE GROUND PER VERY DRY AIRMASS
OVER THE FCST AREA. AS SUCH...RUNNING WITH VERY LOW POPS WEDNESDAY
NIGHT WITH LITTLE (UPWARDS OF AN INCH IN NW GREENBRIER?) OR NO SNOW
ACCUMULATION. PASSAGE OF THIS WAVE WILL BRING REINFORCING SURGE OF
ARCTIC AIR TO THE AREA THURSDAY.
THE SECOND SHORT WAVE IS FORECAST TO DIP A BIT FARTHER SOUTH...
TAPPING RIBBON OF GULF MOISTURE FOR FRIDAY. AREA OF ISENTROPIC LIFT
IS FORECAST TO PASS ALMOST DIRECTLY OVHD WITH ENOUGH LIFT TO
GENERATE UPWARDS OF A THIRD OF AN INCH OF QPF. THE SUBFREEZING
ANTECEDENT CONDITIONS SUGGEST WE WILL BE LOOKING AT P-TYPE ISSUES
WITH POTENTIAL FOR BOTH FREEZING AND FROZEN PRECIPITATION
AREAWIDE...AND COVERING A LARGE GEOGRAPHIC SWATH FROM THE OHIO
VALLEY EASTWARD THROUGH THE MID ATLANTIC AND POINTS NORTH. FOR OUR
CWA...ESP THE SOUTHERN HALF...MODEL FORECAST SOUNDINGS INDICATE WARM
NOSE (+1 TO +3 DEG C) VCNTY OF 800 MB TO OVERRIDE THE SHALLOW BUT
VERY COLD BOUNDARY LAYER. LATEST MODELS HAVE TRENDED COLDER WITH
THIS SYSTEM SUGGESTING A GOOD PORTION OF THE QPF MAY BE SNOW OR
SLEET B4 CHANGING TO FREEZING RAIN. ATTM THINK WE WILL BE LOOKING
AT WINTER WEATHER ADVISORY CONDITIONS FRIDAY. WOULD NEED A BIT MORE
QPF...OR...FOR ALL OF THE PRECIP TO FALL AS FREEZING RAIN IN ORDER
TO JUSTIFY A WATCH/WARNING SORT OF CONCERN. AT THE VERY
LEAST...THIS WILL BE A CONCERN FOR SCHOOLS/DOT/TRAVEL INTERESTS AS
THE GROUND WILL BE FROZEN ALLOWING FOR EASY ACCUMULATION FOR
WHATEVER WINTER PTYPE OCCURS.
TEMPERATURES THROUGH THE END OF THE WEEK WILL STRUGGLE TO REACH
FREEZING. EVEN FOR AREAS THAT MANAGE TO GET ABOVE FREEZING...THE
WETBULB WILL REMAIN BELOW 32. THIS SUGGESTS THE REMAINING SNOWCOVER
IN THE MOUNTAINS IS NOT GOING ANYWHERE FOR THE REST OF THIS WEEK.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 400 AM EST TUESDAY...
ANY WARM AIR THAT TRIES TO DISPLACE THE COLD AIR FRIDAY WILL GET
SQUASHED BY SATURDAY. NORTHWEST WINDS ARE FORECAST TO DEVELOP IN
THE WAKE OF FRIDAYS SYSTEM...85H TEMPS DIPPING BACK DOWN TO NEAR M15
BY SATURDAY MORNING. THIS SAME NORTHWEST FLOW WILL RESULT IN
PERSISTENT CLOUDS/-SHSN/FLURRIES OVER THE MOUNTAINS WITH DRY BUT
BRISK CONDITIONS ELSEWHERE.
SUNDAY WILL BRING TRANSITION BACK TO SUNNY SKIES...WINDS
DIMINISHING...1035 MB HIGH PRESSURE PASSING OVERHD. A WARMING TREND
IS EXPECTED TO GET UNDERWAY FOR THE FOLLOWING WEEK AS SOUTHERLY WINDS
DEVELOP AROUND THE DEPARTING ANTICYCLONE...TEMPERATURES TRENDING
BACK ABOVE NORMAL. THE PATTERN ALSO LOOKS WET...WINDFLOW COMING UP
FROM THE GULF COAST REGION.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
AS OF 125 AM EST TUESDAY...
COLD HIGH PRESSURE OVER THE NORTHERN PLAINS WILL MOVE
SOUTHEAST TO TENNESSEE VALLEY/EASTERN GULF COAST BY WEDNESDAY
MORNING. THE COLD AIR WILL FLOW OVER THE GREAT LAKES AIDING IN THE
DEVELOPMENT OF LAKE EFFECT SNOW DOWNWIND FROM THE GREAT LAKES
THROUGH WEDNESDAY MORNING. THIS WILL RESULT IN THE POTENTIAL FOR
MVFR CONDITIONS VCNTY OF BLF/LWB BY MID WEEK. EAST OF THE
MTNS...PRIMARILY VFR CONDITIONS EXPECTED THROUGH THE TAF PD.
WINDS WILL BE GUSTY ATTMS WITH SFC GUSTS APPROACHING 30KTS FROM
THE WEST OR NORTHWEST TONIGHT INTO TUESDAY MORNING.
ISENTROPIC LIFT/WARM FRONT MAY BRING LIGHT FREEZING DRIZZLE OR
FLURRIES TO LWB/BLF FOR A FEW HOURS ON THURSDAY OR THURSDAY NIGHT.
A LOW PRESSURE SYSTEM AND FRONT MOVING THROUGH THE TN VALLEY MAY
OVERSPREAD THE REGION WITH RAIN/FREEZING RAIN/SNOW/SLEET WITH IFR
CIGS BLF/LWB/BCB LATE FRIDAY OR FRIDAY NIGHT. WINDS MAY ALSO GUST
TO 30 KTS IN THE WAKE OF FRIDAYS WEATHER SYSTEM.
GUSTY WINDS CONTINUE SATURDAY WITH IFR CIGS/VIS POTENTIALLY WITH
SNOW SHOWERS AT LWB/BLF.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR VAZ007-009>018-
023-024.
WIND CHILL ADVISORY UNTIL NOON EST WEDNESDAY FOR VAZ019-020.
NC...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR NCZ001-002-018.
WV...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR WVZ042>044.
WIND CHILL ADVISORY UNTIL NOON EST WEDNESDAY FOR WVZ045.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PM
LONG TERM...PM/RCS
AVIATION...AMS/PM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1129 PM CST MON JAN 21 2013
.SHORT TERM...TONIGHT THROUGH THURSDAY
300 PM CST MON JAN 21 2013
MAIN FORECAST CONCERNS ARE ON HOW QUICK THE CURRENT ARCTIC AIRMASS
MODIFIES...IF SNOW CAN FORM OFF OF LAKE PEPIN AGAIN TONIGHT...AND
LIGHT SNOW CHANCES TUESDAY NIGHT THROUGH THURSDAY.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF THE U.S. INTO BRITISH
COLUMBIA...WHILE DEEP TROUGHING WAS IN PLACE OVER SOUTHEAST CANADA
INTO THE WESTERN GREAT LAKES REGION. UNDER THIS DEEP TROUGHING...
850MB TEMPS WERE -25C AT MPX...-27C AT GRB AND -35C AT INL PER 12Z
SOUNDINGS...OR 2 TO 2.5 STANDARD DEVIATIONS BELOW NORMAL. THESE COLD
READINGS...COMBINED WITH A NORTHWEST BREEZE RESULTING FROM A TIGHT
PRESSURE GRADIENT BETWEEN LOW PRESSURE IN NORTHERN LAKE HURON AND
ARCTIC HIGH PRESSURE IN THE DAKOTAS...HAVE RESULTED IN TEMPERATURES
ONLY SLOWLY RISING TODAY. STILL...WITH MOST OF THE AREA EXCLUDING
NORTH OF HIGHWAY 10 HAVING BARE GROUND...AND SUNSHINE THROUGH SOME
CONVECTIVELY INDUCED STRATOCUMULUS UNDER THE 850MB THERMAL TROUGH
HAS ALLOWED TEMPERATURES SOUTH OF HIGHWAY 10 TO CLIMB TO OR SLIGHTLY
ABOVE ZERO. WIND CHILLS ARE STILL 15 TO 30 BELOW...THOUGH. TO THE
WEST...RAP ANALYSIS SHOWED A 140KT JET AT THE TROPOPAUSE DROPPING
DOWN THROUGH THE EASTERN DAKOTAS. ALONG AND WEST OF THIS UPPER JET
STREAK...MID AND HIGH CLOUDS ARE PRESENT...REFLECTING THE UPPER
LEVEL MOISTURE SEEN ON WATER VAPOR. 850MB TEMPS WARM QUITE A BIT TOO
WEST OF THE UPPER JET...AS EXPECTED THROUGH THE THERMAL WIND
RELATIONSHIP...CLIMBING FROM -23C AT BIS TO -14C AT UNR PER 12Z
SOUNDINGS.
TONIGHT AND TUESDAY...THE UPPER LEVEL PATTERN IS NOT FORECAST TO
CHANGE MUCH OVER THE NEXT 24 HOURS...WITH PERHAPS ONLY A SLIGHT
EASTWARD PROGRESSION TO THE WESTERN RIDGE AND DEEP TROUGH.
HOWEVER...THIS PROGRESSION WILL BE ENOUGH TO SLIDE THE ARCTIC HIGH
OVER THE DAKOTAS INTO THE FORECAST AREA BY 00Z WEDNESDAY...ALONG
WITH THE UPPER JET STREAK AND THE MID/HIGH CLOUDS ACCOMPANYING THE
JET STREAK. OF INTEREST TONIGHT IS TO SEE IF ANOTHER NARROW BAND CAN
FORM OFF LAKE PEPIN...WHICH WILL DEPEND ON IF THE LAKE WAS ABLE TO
FREEZE OVER. LAST NIGHT...WITH THE ARCTIC AIR FLOWING IN...A NARROW
BAND FORMED WITH VISIBILITIES LESS THAN 1/4 MILE. SEE OUR NEWS STORY
ON OUR WEBSITE FOR MORE ABOUT THE BAND. THE 20.12Z HIRES-ARW
YESTERDAY SHOWED THE BAND HAPPENING LAST NIGHT...THOUGH THE THOUGHT
AT THE TIME WAS THAT THE ENTIRE MISSISSIPPI RIVER SYSTEM WAS FROZEN
OVER. THE 21.06Z/12Z HIRES-ARW SHOW A BAND FORMING AGAIN TONIGHT...
AND GIVEN THAT IT HAS STAYED BREEZY TODAY TO HELP PREVENT ICE
FORMATION ON LAKE PEPIN...HAVE THUS INCLUDED SOME SMALL
PRECIPITATION CHANCES FOR THE BAND BETWEEN 06-15Z TUESDAY. OTHERWISE
TEMPERATURES AND WIND CHILLS ARE THE MAIN ISSUE. THE 925MB THERMAL
TROUGH REMAINS IN PLACE TONIGHT WITH READINGS OF -24 TO -28C...
COLDEST NORTH OF I-94. SINCE WE MAINTAIN A BREEZE MOST OF THE
NIGHT...THE BOUNDARY LAYER SHOULD REMAIN MIXED AT LEAST UP TO 950MB
IF NOT TO THAT 925MB LEVEL...RESULTING IN LOWS BETWEEN 5 AND 15
BELOW. COLDEST READINGS WOULD OCCUR NORTH OF HIGHWAY 10 WHERE A
LITTLE SNOW PACK EXISTS. ON TUESDAY...GRADUAL WARMING TAKES PLACE TO
THE 925MB TEMPS WITH THE SHIFT EAST OF THE DEEP TROUGHING...CLIMBING
TO -19 TO -23C BY 21Z. THUS...WE SHOULD SEE HIGHS JUST A FEW DEGREES
WARMER THAN THOSE TODAY UNDER MOSTLY SUNNY SKIES.
TUESDAY NIGHT AND WEDNESDAY...THERE HAS BEEN A TREND TO SLOW UP THE
PATTERN MORE DURING THIS TIME PERIOD COMPARED TO PREVIOUS
FORECASTS...AND TO SOME DEGREE DRAMATICALLY. THE REASON FOR THE SLOW
DOWN IS THAT MODELS HAVE FOCUSED ON A POTENT SHORTWAVE DROPPING
SOUTH OUT OF NORTHERN MANITOBA. ALL MODELS HAVE IT DIGGING DOWN INTO
UPPER MICHIGAN AND EVEN NORTHERN WISCONSIN BY 00Z THURSDAY. THIS
HOLDS UP THE RIDGE OVER THE WESTERN U.S. FROM PUSHING EAST. IN
ADDITION...WE END UP NOW SEEING ANOTHER ARCTIC HIGH DROPPING DOWN
INTO THE RED RIVER VALLEY OF NORTH DAKOTA...WITH A COLD FRONTAL
PASSAGE COMING THROUGH THE FORECAST AREA AHEAD OF IT DURING THE DAY
WEDNESDAY. PRIOR TO THIS FRONTAL PASSAGE...THE 21.12Z CANADIAN/UKMET
AND 21.00Z ECMWF DEPICT A BAND OF LIGHT QPF COMING INTO THE FORECAST
AREA FROM THE WEST...REACHING ABOUT THE MISSISSIPPI RIVER SOUTH OF
I-90 BY 12Z WEDNESDAY. THIS BAND IS THAT SAME BAND OF MID/HIGH
CLOUDS TRAVERSING THE PLAINS WHICH ENDS UP MARCHING EAST. GIVEN THAT
THERE ARE OBSERVATIONS OF SNOW UNDER THE BAND...HAVE MAINTAINED
FLURRIES AND INCLUDED 20 PERCENT CHANCES. THE BAND DOES WEAKEN OVER
TIME AS THAT POTENT SHORTWAVE DIGS SOUTH...AND AFTER 18Z ANY
FLURRIES ASSOCIATED WITH IT SHOULD HAVE SHIFTED OFF TO THE
SOUTHEAST. SOME FLURRY ACTIVITY COULD OCCUR NORTH OF I-94 IN THE
AFTERNOON WITH THE SHORTWAVE. WITH MORE CLOUDS TUESDAY NIGHT...
EXPECT A WARMER NIGHT...AND IN FACT TEMPERATURES COULD RISE AFTER
MIDNIGHT AS 925MB TEMPS WARM WITH THE SOUTHWEST WINDS AHEAD OF THE
FRONT. THE WARMER NIGHT PLUS 925MB TEMPS OF -12 TO -18C AT 18Z
WEDNESDAY SHOULD YIELD HIGHS IN THE TEENS TO LOW 20S IN MOST
LOCATIONS.
WEDNESDAY NIGHT AND THURSDAY...GOOD AGREEMENT EXISTS AMONG THE
21.12Z GFS/ECMWF/UKMET/CANADIAN OF TAKING A POTENT SHORTWAVE TROUGH
COMING INTO THE PACIFIC NORTHWEST AT 00Z THURSDAY ACROSS THE
NORTHERN ROCKIES...THEN INTO THE DAKOTAS BY 00Z FRIDAY. AGAIN...THIS
IS QUITE A BIT SLOWER THAN YESTERDAYS FORECAST. THE NAM IS AN
OUTLIER BY ALMOST BRINGING IT INTO MN...BUT IS NOT DEEP ENOUGH
DIGGING THE WEDNESDAY SHORTWAVE. GIVEN THE SLOWER TREND...THE SPREAD
OF DPVA AND WARM ADVECTION / FRONTOGENESIS INDUCED SNOW DOWNSTREAM
IS SLOWER TOO...WITH DRY CONDITIONS NOW INDICATED THROUGH AT LEAST
18Z THURSDAY FOR THE FORECAST AREA. AFTER 18Z...MODELS CONTINUE TO
BACK OFF ON THE AMOUNT OF PRECIPITATION...PRIMARILY BECAUSE THIS
POTENT SHORTWAVE TROUGH IS MOISTURE STARVED. ALL THE BETTER MOISTURE
IS TIED UP WITH A SOUTHERN STREAM-TYPE SHORTWAVE AND SURFACE LOW
PRESSURE SYSTEM OVER THE SOUTHERN PLAINS. THERE STILL IS SOME LIGHT
SNOW INDICATED OVER THE AREA PER THE 27.12Z ECMWF...BUT THE 27.12Z
GFS IS DRY. THEREFORE...HAVE LOWERED CHANCES ABOUT 10 PERCENT. IF
TRENDS CONTINUE...LIKELY THURSDAY WILL END UP DRY WITH JUST SOME
INCREASING MID AND HIGH CLOUDS. DUE TO THE DEEPER WEDNESDAY
SHORTWAVE TROUGH...HAVE LOWERED LOWS A FEW DEGREES WEDNESDAY NIGHT
TO ACCOUNT FOR MORE CANADIAN AIR ADVECTING IN. 925MB TEMPS ACTUALLY
FALL TO AROUND -20C BY 12Z THURSDAY. WIND CHILLS LOOK TO STAY OUT OF
ADVISORY CRITERIA THIS TIME...THOUGH. WITH MORE CANADIAN AIR IN
PLACE ON THURSDAY...ENDING UP ALSO COOLING THURSDAY JUST
SLIGHTLY...BUT HAVING BARE GROUND AND A LITTLE MORE SUN WILL HELP
COUNTERACT THE COLDER 850MB TEMPS.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
300 PM CST MON JAN 21 2013
21.12Z ECMWF/CANADIAN/GFS AND ECMWF ENSEMBLES STILL IN PRETTY GOOD
AGREEMENT FOR THE LONG TERM FORECAST AND SHOW A SIMILAR SOLUTION TO
YESTERDAY. THERE ARE TWO MAIN DIFFERENCES:
1. THE THURSDAY NIGHT DEAL WITH RESPECT TO PRECIPITATION IS NOW
LOOKING A LOT LESS THAN WHAT THE 20.12Z ECMWF HAD...SINCE WE ARE
ONLY INFLUENCED BY THAT POTENT SHORTWAVE DROPPING THROUGH THE AREA
FRIDAY MORNING. ALL OF THE MOISTURE AGAIN IS TIED UP WITH THE
SOUTHERN STREAM SYSTEM...SO AT MOST WE END UP WITH A FEW HUNDREDTHS
OF LIQUID EQUIVALENT. GIVEN THE POTENT NATURE OF THE TROUGH...
DEFINITELY MAINTAINED SOME 30-40 PERCENT CHANCES OF PRECIPITATION
FOR THURSDAY NIGHT. FUTURE FORECASTS MAY HAVE TO RAISE THESE SINCE
IT IS LOOKING LIKE MOST LOCATIONS SHOULD BE ABLE TO GET A
HUNDREDTH. ALSO ADDED SOME LOW CHANCES OF PRECIPITATION TO FRIDAY
BEING UNDER THE SHORTWAVE TROUGH TO ALLOW FOR A MORE CONVECTIVE
SITUATION.
2. UPPER RIDGING IS STILL PROGGED TO BUILD TOWARDS THE AREA FOR THE
WEEKEND...BRINGING TEMPERATURES BACK UP TO NEAR AND EVEN ABOVE
NORMAL FOR SUNDAY. HOWEVER...NOW THERE ARE INDICATIONS OF A
SHORTWAVE TROUGH MOVING THROUGH THIS RIDGING...IMPACTING THE AREA ON
SUNDAY. FOLLOWED THE CONSENSUS AND ADDED 20 PERCENT CHANCES OF SNOW
TO THE FORECAST. THIS TROUGH ALSO HOLDS BACK SOME OF THE WARMING
THAT WOULD HAVE OCCURRED UNDER THE LOW LEVEL SOUTHWEST FLOW.
HEADING INTO MONDAY...MORE TROUGHING IS SUGGESTED ALONG THE WEST
COAST OF THE U.S....BUT UNCERTAINTY EXISTS ON WHETHER IT SPLITS INTO
TWO AS SHOWN BY THE 21.12Z ECMWF OR STAYS TOGETHER PER 21.12Z GFS.
21.12Z ECMWF ENSEMBLE MEAN SEEMS TO SUGGEST BOTH SCENARIOS ARE
PLAUSIBLE. EITHER SCENARIO AT LEAST FOR MONDAY DOES NOT RESULT IN
ANY PRECIPITATION FOR US...WITH WARMING COMING BACK INTO THE AREA IN
THE WAKE OF THE SUNDAY SHORTWAVE TROUGH. READINGS LOOK LIKE THEY
SHOULD GET BACK ABOVE FREEZING FOR HIGHS.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1129 PM CST MON JAN 21 2013
SIMILIAR CONDITIONS EXPECTED TO CONTINUE WITH MAINLY SCATTERED
STRATO CUMULUS WITH BASES BETWEEN 015K-025K FEET THROUGH 00Z
WEDNESDAY. WILL LIKELY BE SOME PERIODS OF BROKEN CEILINGS WHICH
COULD PRODUCE A FEW FLURRIES. MID LEVEL CLOUDS WILL INCREASE AFTER
00Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 PM CST MON JAN 21 2013
WI...WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR MNZ079-086>088-
094>096.
IA...WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1022 PM CST MON JAN 21 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.PREV DISCUSSION...ISSUED AT 749 PM CST MON JAN 21 2013...
UPDATE...THE CORE OF THE COLDEST POOL OF AIR WL MOVE ACROSS THE
AREA THIS EVENING...THEN BEGIN EDGING OFF TO THE E LATE TNGT. BUT
THERE WL STILL BE SOME NOCTURNAL DROP OFF IN TEMPS TNGT...SO VERY
COLD READINGS ARE LIKELY BY TOMORROW MORNING.
UNLIKE YDA NGT WHEN SECONDARY PUSH OF CAA LATER IN THE NGT
STEEPENED LOW-LEVEL LAPSE RATES AND CAUSED WINDS TO PICK UP LATE
AT NGT AND DURING THE EARLY MORNING HRS...THINK WE WL SETTLE INTO
A MORE STEADY STATE 7-14 MPH WIND IN MOST AREAS OVERNIGHT. WINDS
WL PROBABLY DROP OUT AT TIMES IN SOME OF THE MORE PROTECTED AREAS
OF N-C WI. THAT WL PROBABLY CAUSE WIND CHILL INDICES TO BOUNCE
ARND SOME...AND THEY AREN/T GOING TO FIT CLEANLY INTO OUR
ADVISORY/WARNING CRITERIA AT ALL TIMES. BUT CURRENT HEADLINES SEEM
ON TARGET FOR HILIGHTING THE DANGER OF FROSTBITE TO ANYONE GOING
OUTDOORS WITHOUT TAKING APPROPRIATE PRECAUTIONS...SO SEE NO REASON
TO MAKE ANY CHANGES.
UPDATED PRODUCT SUITE OUT ASAP.
SKOWRONSKI
DISCUSSION ISSUED AT 448 PM CST MON JAN 21 2013...
SHORT TERM...TONIGHT AND TUESDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE STRETCHING SOUTHEAST ACROSS THE GREAT PLAINS EARLY THIS
AFTERNOON. WEAK SHORTWAVE IS DROPPING ACROSS THE STATE WHICH IS
CONTRIBUTING TO A STRATO-CU FIELD...WITH THE HELP FROM STEEP LOW
LEVEL LAPSE RATES. SCT FLURRIES ARE FALLING OUT OF THIS STRATO-CU
DECK FROM THE SOUTHERN FOX VALLEY TO CENTRAL AND NORTH-CENTRAL
WISCONSIN. TEMPERATURES AND WIND CHILL READINGS HAVE HARDLY BUDGED
SINCE EARLIER THIS MORNING...AND PLENTY OF 30-35 BELOW WIND CHILL
READINGS REMAIN OVER NORTH-CENTRAL WISCONSIN. FORECAST CONCERNS
INCLUDE CLOUD TRENDS AND WIND CHILL HEADLINES.
TONIGHT...ARCTIC HIGH PRESSURE WILL BE BUILDING SOUTHEAST ACROSS THE
NORTHERN MISSISSIPPI VALLEY THROUGH THE NIGHT. SHORTWAVE TROUGH
OVERHEAD WILL BE EXITING THE REGION BY LATE THIS AFTERNOON OR EARLY
THIS EVENING. WITH LOSS OF A SMALL DIURNAL COMPONENT...AM COUNTING
ON INCREASING SUBSIDENCE TO HELP GRADUALLY DISSIPATE MUCH OF THE
STRATO-CU FIELD OVER CENTRAL AND EAST-CENTRAL WISCONSIN THIS
EVENING. NORTH-CENTRAL WISCONSIN MAY NOT CLEAR OUT MUCH AT ALL...AS
LOW LEVEL WINDS VEER AROUND SLIGHTLY TO THE NORTHWEST AND PUSH LAKE
EFFECT CLOUDS SOUTHEAST BENEATH A FAIRLY SHARP INVERSION. TOO COLD
FOR MUCH ACCUMS...BUT POSSIBLY UP TO AN INCH OVER THE FAR NORTHERN
PART OF THE COUNTY. THE CLEARING SKIES WILL HELP TEMPS BECOME
COLDER TONIGHT COMPARED TO LAST NIGHT...BUT THIS WILL BE OFFSET BY A
WEAKENING PRESSURE GRADIENT AND WIND SPEEDS. APPARENT TEMP GRIDS
SHOW WIND CHILLS FALLING ONLY A FEW DEGREES THIS EVENING...BUT
READINGS HAVE REMAINED STEADY ACROSS NORTH-CENTRAL WISCONSIN
TODAY...SO WILL NOT TAKE MUCH OF A FALL TO REACH WARNING CRITERIA.
AFTER COORDINATING WITH SURROUNDING OFFICES...WILL ISSUE A WIND
CHILL WARNING WHERE AM MOST CONFIDENT IN REACHING CRITERIA...FROM
LINCOLN AND LANGLADE TO VILAS AND FOREST COUNTY STARTING THIS
EVENING AND GOING THROUGH MID-MORNING TUESDAY.
TUESDAY...ARCTIC HIGH PRESSURE WILL BE SLIDING TO THE OHIO VALLEY.
CORE OF THE COLDEST AIR WILL BE SHIFTING TO THE NORTHEAST...ALONG
WITH THE HIGHER LOW LEVEL HUMIDITY. BUT WILL ALREADY BE OFF TO A
VERY COLD START SO TEMPS WILL NOT BE SIGNIFICANTLY WARMER THAN
TODAYS READINGS. WITH WINDS BACKING TO THE WEST...SHOULD SEE MORE
SUNSHINE THAN TODAY. WINDS WILL ALSO BE LIGHTER...AND WIND CHILL
READINGS SHOULD BE IMPROVING RAPIDLY BY MID TO LATE MORNING. WILL
CONTINUE TO RUN WIND CHILL HEADLINES TO 18Z. HIGHS RANGING FROM 5
BELOW NORTH TO ABOUT 4 ABOVE NEAR LAKE MICHIGAN.
LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. PRIMARY ISSUE
CONTINUES TO BE THE DURATION OF THE COLD AIR THIS WEEK FOLLOWED BY
A CLIPPER TYPE SYSTEM LATER THIS WEEK.
COLD AIR INTRUSION CONTINUES TUESDAY NIGHT WITH THE LIKELY CHANCE
OF ADDITIONAL WIND CHILL HEADLINES ACROSS AT LEAST THE NORTH HALF
OF THE FORECAST AREA. A WEAK TROUGH IS PROGGED DROPS OVER THE GREAT
LAKES REGION IN THE NORTHWEST FLOW WED INTO WED EVENING...FOLLOWED
WITH ANOTHER BRIEF PERIOD OF CAA INTO THURSDAY MORNING.
THIS BIT LONGER DURATION OF COLDER AIR INTO WEDNESDAY NIGHT
PRECEDES THE TREND OF SLOWING DOWN THE CLIPPER TYPE SYSTEM FOR
LATER THURSDAY AND INTO FRIDAY MORNING...WHICH IS SUPPORTED BY THE
LAST FEW MODEL RUNS. WOULD NOT BE SURPRISED WITH LATER RUNS
INDICATING THE CLIPPER WILL LINGER MORE INTO FRIDAY AS THIS
CLIPPER SYSTEM PHASES WITH A SOUTHERN STREAM SYSTEM. COULD SEE A
FEW INCHES OF SNOW BY FRIDAY OVER MOST LOCATIONS.
AFTER A BRIEF PERIOD OF CAA IN THE WAKE OF THE CLIPPER...GRADUALLY
MODERATING TEMPERATURES TO NEAR SEASONAL NORMS STILL EXPECTED FOR
THE WEEKEND AND INTO MONDAY.
WAA FOR SUNDAY ALONG WITH A H850 TROUGH TRACKING OVER THE AREA
MAY WILL PROVIDE A CHANCE FOR LIGHT SNOW OR FLURRIES.
LAKE EFFECT POTENTIAL. THE CHANCE FOR LAKE EFFECT SNOWS INCREASE
TOWARD WEDNESDAY NIGHT OVER FAR NORTHERN WISCONSIN AS THE SHORT
WAVE TROUGH SWINGS THROUGH AND WINDS TURN BRIEFLY NORTHWEST AGAIN.
NORTHWEST WINDS WILL NOT LAST LONG AS THE COLD SURFACE HIGH
DROPS INTO THE REGION. BUT WINDS BEGIN TO TURN MORE EASTERLY
THURSDAY INTO THURSDAY NIGHT TO INCREASE THE POTENTIAL OF MORE
SNOW SHOWERS ALONG LAKE MICHIGAN..ESPECIALLY AS THE WEAK CLIPPER
TRACKS THROUGH TO PROVIDE SOME LIFT. COULD HAVE HIGHER SNOW
AMOUNTS ALONG THE LAKE MICHIGAN SHORELINE THURSDAY NIGHT INTO
FRIDAY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE. VFR CONDITIONS EXPECTED AS
ARCTIC AIR DOMINATES THE AREA. THE ONLY EXCEPTION WL BE NR THE
UPPER MICHIGAN BORDER WHERE CLDS OFF LAKE SUPERIOR WL DROP CIGS
INTO MVFR CAT AT TIMES.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR WIZ012-013-
020>022-030-031-035>040-045-048>050-073-074.
WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ005-010-011-018-
019.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
944 AM CST TUE JAN 22 2013
.UPDATE...
MORNING UPDATE HAS LOWERED HIGHS SLIGHTLY AND LESSENED SNOW
WORDING. FORECAST SOUNDINGS VS CURRENT OBS SUGGEST HIGHS NEEDED TO
BE TRIMMED A BIT...MAINLY CENTRAL AND SW. CLOUDS SHOULD STAY IN
PLACE AND COLD AIR SEEMS TO STILL BE ENTRENCHED WITH 15Z OBJECTIVE
ANALYSIS STILL INDICATING WEAK PRESSURE RISES. WATER VAPOR IMAGERY
AND LATEST RAP OUTPUT ALSO SUGGEST WEAK SHORT WAVE/PV ANOMALY JUST
EXITING IA. VISIBLE IMAGERY ALSO SHOWS DEEPER TEXTURE ADVANCING
INTO MO WHICH IS SUPPORTED BY REGIONAL RADAR MOSAIC SO HAVE REDUCED
POPS AND ACCUMULATIONS. BETTER POTENTIAL MAY BE NORTH TONIGHT WHICH
WILL BE RE-EVALUATED WITH AFTERNOON PACKAGE.
REMNANTS OF WIND CHILL ADVISORY WILL BE ALLOWED TO EXPIRE AT 16Z.
&&
.SHORT TERM /TODAY/...
AREA OF SURFACE HIGH PRESSURE OVER THE AREA TO SLOWLY DRIFT EASTWARD
AND SOUTHWARD TODAY...WITH CONTINUED NORTHWEST FLOW ALOFT. WEAK
IMPULSES CONTINUE TO DROP SOUTHEASTWARD THROUGH THE STATE
TODAY...ALONG WITH ZONE OF WAA/MOISTURE ADVECTION IN THE LOW/MID
LEVELS MIGRATING OVER THE CWA THROUGH THE DAY SHOULD LEAD TO WEAK
LIFT IN THE LOW/MID LEVELS THROUGHOUT THE DAY. ALSO DECENT
ISENTROPIC LIFT SHOWING UP ACROSS EXTREME SOUTHWESTERN CWA THIS
MORNING...AND PUSHING EAST/NORTHEASTWARD THIS AFTERNOON. AMOUNT OF
MOISTURE BECOMES THE MAIN ISSUE...BUT SOUNDINGS SHOWING DECENT
SATURATION ACROSS MUCH OF THE EASTERN CWA AT VARIOUS TIMES
THROUGHOUT THE DAY. ALSO WITH COLD AIR IN PLACE BULK OF
LIFT/SATURATION IN THE DENDRITIC LAYER. THEREFORE EVEN THOUGH
MOISTURE IS LIMITED...SNOWFALL PRODUCTION WILL BE EFFICIENT THUS
HAVE GONE WITH HIGHER POPS ACROSS THE SOUTHWEST THIS MORNING AND
WEST/NORTHWEST THIS AFTERNOON. FEEL LIFT/MOISTURE AMOUNTS SHOULD BE
ABLE TO SQUEEZE OUT A FEW TENTHS TO HALF AN INCH OR SO THROUGHOUT
THE DAY. WAA WILL HELP TEMPS REBOUND SOME TODAY...BUT CLOUDS WILL
INHIBIT THE WARMING SOME. THEREFORE STILL KEPT TEMPS ON THE COLD
SIDE WITH HIGHS ONLY AROUND 10 ABOVE ACROSS THE NORTHEAST TO AROUND
20 SOUTH AND SOUTHWEST. BITTERLY COLD WIND CHILLS STILL EXPECTED
THIS MORNING...SO HAVE CONTINUED THE WIND CHILL ADVISORY ACROSS THE
NORTHEASTERN CWA THROUGH MID MORNING.
.LONG TERM /TONIGHT THROUGH MONDAY/...
WARM ADVECTION WILL INCREASE ACROSS THE STATE TONIGHT AS BAROCLINIC
ZONE MOVES EAST ACROSS THE STATE. ISENTROPIC LIFT IS EXPECTED TO
PERSIST THROUGH THE BOUNDARY WITH CLOUDS OVER MUCH OF CENTRAL IOWA
DURING THE NIGHT. THE EXCEPTION WOULD BE IN THE SOUTHWEST WHERE
LIFT SUBSIDES BY MIDNIGHT AS MAIN FORCING SHIFTS NORTHEAST. MODEL
SOUNDINGS AT MASON CITY AND WATERLOO SHOW LOWEST 250MB OF SOUNDINGS
CLOSE TO SATURATION IN THE DENDRITIC ZONE. ANTICIPATE SOME LIGHT
SNOW OVERNIGHT ACROSS FAR NORTH CENTRAL INTO NORTHEAST CORNER OF THE
FORECAST AREA AROUND WATERLOO. AMOUNTS WILL BE VERY LIGHT ALTHOUGH
HIGH SNOW RATIOS MAY LEAD TO AN HALF OF INCH OF SNOW IN SOME
LOCATIONS. THE STATE WILL SEE A BRIEF PERIOD OF WARMER TEMPERATURES
INTO WEDNESDAY...HOWEVER A FRONT MOVING THROUGH DURING THE DAY WILL
CURTAIL ANY WARMING ACROSS THE NORTH. READINGS FARTHER SOUTH WILL
HAVE MORE TIME TO RISE AND MAY CLIMB ABOVE FREEZING BY EARLY
AFTERNOON BEFORE COOLING ENSUES. GLANCING BLOW OF COOLER AIR INTO
THURSDAY AS SURFACE RIDGE SLIDES INTO THE GREAT LAKES WITH WARM
ADVECTION RE-INTENSIFYING BY THURSDAY AFTERNOON.
NEXT SYSTEM WILL PASS THROUGH NORTHERN ROCKIES AND APPROACH THURSDAY
NIGHT INTO FRIDAY. LIFT IS FORECAST TO INCREASE QUICKLY BY LATE
THURSDAY AS MOISTURE BEGINS TO RETURN. LIGHT SNOW IS EXPECTED TO
DEVELOP BY THURSDAY EVENING MAINLY ACROSS THE EASTERN HALF OF IOWA
AS MOISTURE EVENTUALLY RETURNS. SOME LIGHT ACCUMULATIONS WILL BE
POSSIBLE IN THE FAR EASTERN OF THE AREA BEFORE THE SYSTEM DEPARTS TO
THE EAST ON FRIDAY MORNING. THERE WILL BE A BRIEF BREAK FROM LATE
FRIDAY INTO SATURDAY EVENING AS HIGH PRESSURE PASSES THROUGH THE
STATE. THE NEXT IN A SERIES OF SYSTEM IS FORECAST TO ARRIVE ON
SUNDAY WITH THE THREAT OF RAIN OR SNOW AS THICKNESSES/TEMPERATURES
CONTINUE TO INCREASE.
&&
.AVIATION...22/12Z
STILL EXPECTING MID/HIGH CLOUDS TO SLOWLY TRANSLATE EASTWARD THROUGH
THE DAY...WITH SOME LOWER CLOUDS POSSIBLE ACROSS THE NORTHERN TAF
SITES TOWARD THE LATTER PORTION OF THE TAF PERIOD. SOME LIGHT
SNOW/FLURRIES ALSO POSSIBLE...WITH GREATEST CHANCES AT THE NORTHERN
TAF SITES TOWARD LATE THIS AFTERNOON INTO TONIGHT. UNCERTAINTY IN
HOW LOW CLOUD DECK WILL GET OR HOW MUCH VSBYS COULD BE REDUCED IN
THE LIGHT SNOW...BUT AN OCCASIONAL DIP INTO MVFR VSBYS/CIGS IS
POSSIBLE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...SMALL
SHORT TERM/AVIATION...BEERENDS
LONG TERM...COGIL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
632 AM EST TUE JAN 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 431 AM EST TUE JAN 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STEADY STATE HI
AMPLITUDE PATTERN WITH DEEP TROF OVER ERN NAMERICA DOWNSTREAM OF RDG
ALONG THE W COAST. CORE OF ARCTIC AIR AT 00Z WAS CENTERED IN NW
ONTARIO OVER YPL...WHICH REPORTED LOWEST H85 TEMP ON THE MAP WITH
-36C. INL/RB ALSO REPORTED NOTEWORTHY H85 TEMPS OF -30C/-31C AT 00Z.
FARTHER NW OF THIS CORE OF COLDEST AIR...00Z H85 TEMPS AT THE PAS
MANITOBA AND CHURCHILL MANITOBA WERE A MUCH MORE MODEST -23C. A FEW
PLACES OVER INTERIOR UPR MI HAVE SEEN SFC TEMPS FALL AS LO AS -15 TO
-20F...WITH LOWEST WIND CHILLS IN THE -30 TO -35F RANGE. WITH
LINGERING CYC NW FLOW OVER THE UPR LKS UNDER THIS BITTERLY COLD
AIR...LES CONTINUES MAINLY IN THE NW WIND SN BELTS. AS EXPECTED...
WITH VERY COLD AIR ELIMINATING THE DGZ...SNOWFLAKE SIZE HAS BEEN
VERY SMALL. THE SMALL FLAKES ARE VERY EFFECTIVE AT REDUCING VSBY...
SO WHERE LES IS OCCURRING...WHITE-OUTS ARE COMMON. FOR THE MOST
PART...SMALL FLAKES ARE LIMITING ACCUMS WITH MOST RECENT SPOTTER/
COOP REPORTS INDICATING MOSTLY 1-3IN/12HR SNOWFALL RATES. EXCEPTION
IS OVER THE FAR NE FCST AREA...WHERE MORE LONGER FETCH/MORE LK
MODERATION IS LIKELY ALLOWING THE DGZ INTO THE LOWEST LYRS AND
SHARPER LLVL CNVGC ENHANCED BY LAND BREEZES IS PROVIDING EXTRA LLVL
LIFT/FOCUS FOR SHSN. LOOKING JUST UPSTREAM TO THE NW...A WEAKER PRES
GRADIENT IS APPARENT UPSTREAM OF LK SUP.
TODAY...CWA WL REMAIN UNDER PERSISTENT NW FLOW ALF...BUT CORE OF
COLDEST AIR NOW IN PLACE IS PROGGED TO SHIFT TO THE E AS THE LLVL
FLOW BACKS...WITH H85 TEMPS FCST TO RISE TO WITHIN A FEW DEGREES OF
-25C BY 00Z THIS EVNG. COMBINATION OF CORE OF COLDEST AIR SHIFTING
TO THE E AND LIGHTER WINDS THAN YDAY WITH ARRIVAL OF WEAKER PRES
GRADIENT SHOULD ALLOW SOME MODERATION IN THE WIND CHILLS. SO GOING
ADVY EXPIRATION OF THOSE ADVYS AT 18Z LOOKS ON TRACK. HOWEVER...THE
AIRMASS WL REMAIN MORE THAN SUFFICIENTLY COLD FOR PERSISTENT LES/LK
CLDS DESPITE LARGER SCALE QVECTOR DVGC/SUBSIDENCE THAT IS FCST TO
LOWER INVRN BASE TOWARD 5K FT AND LIMIT DEPTH OF MSTR. BUT FCST
SDNGS STILL SHOW TEMPS WITHIN THE COLUMN WL REMAIN TOO LO FOR SN
FLAKE GROWTH...SO EXPECT FINER FLAKES TO REMAIN THE RULE. HEAVIER
LES WITH SOMEWHAT HIER TEMPS MODERATED BY LONGER FETCH OVER THE LK
AND LINGERING SHARPER LLVL CNVGC WL REMAIN THE RULE IN AREAS E OF
MUNISING. AS THE LARGER SCALE FLOW BACKS MORE WNW...EXPECT THE LES
OVER THE ERN CWA TO BECOME MORE CONFINED TO AREAS NEAR LK SUP E OF
MUNISING. OVER THE W...THE LES BANDS SHOULD SHIFT N OUT OF GOGEBIC
COUNTY BUT STILL IMPACT AREAS FM ONTONAGON THRU THE KEWEENAW.
TNGT...EXPECT A CONTINUED SLOW MODERATION AS LLVL WNW FLOW SHIFTS
COLDEST H85 AIR TO THE E. BY 12Z...H85 TEMPS ARE PROGGED TO BE ARND
-22C. LES SHOULD BE CONFINED TO MAINLY AREAS N OF ONTONAGON OVER THE
W AND TO NEAR LK SUP E OF PICTURED ROCKS OVER THE ERN CWA. WITH SOME
MODERATION IN THE CHILL...SN/WATER RATIOS WL LIKELY BECOME HIER WITH
EMERGENCE OF THE DGZ IN THE LOWEST FEW THOUSAND FEET OF THE
CONVECTIVE LYR. WITH THE MODERATING AIRMASS...MIN TEMPS WL NOT BE AS
LO AS THIS MRNG AT MOST SPOTS EXCEPT OVER THE INTERIO WCNTRL WHERE
LIGHTER WINDS AND AT LEAST SOME CLRG WL ALLOW MORE RADIATION
COOLING. SINCE WINDS OVER THE COLDER INTERIOR SHOULD GENERALLY BE
UNDER 10 MPH...SUSPECT WIND CHILLS FOR THE MOST PART WL REMAIN ABV
ADVY CRITERIA. OPTED TO EXTEND LES WRNG FOR ALGER/LUCE COUNTIES AND
WINTER WX ADVY FOR ONTONAGON COUNTY/THE KEWEENAW THRU TNGT TO
ACCOUNT FOR EXPECTED TRENDS NOTED ABV.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 431 AM EST TUE JAN 22 2013
MODELS ARE IN GOOD AGREEMENT THROUGH ALL BUT SUN/MON...SO FORECAST
CONFIDENCE IS HIGH THROUGH MOST OF THE LONG TERM.
WED AND WED NIGHT...AN UPPER TROUGH WILL PUSH THROUGH THE CWA
WED...HELPING FORM A MESO-LOW /AS INDICATED BY MAJORITY OF MODELS/
OVER FAR ERN LAKE SUPERIOR. WINDS WILL INITIALLY BE OUT OF THE WNW
WED MORNING...BUT WILL TURN NLY BY 00Z THU AFTER THE TROUGH
PASSES...THE MESO LOW DIMINISHES AND A SFC HIGH BEGINS PUSHING IN
FROM THE NW. 850MB TEMPS WILL START THE DAY AROUND -22C AND END THE
DAY AROUND -25C. EARLY IN THE DAY CONDITIONS WILL BE PRIME FOR
MODERATE TO LOCALLY HEAVY LES...BUT BY TIME WINDS TURN NLY...DRY AIR
AND LOWERING INVERSIONS WILL BEGIN TO LIMIT LES TO LIGHT TO MODERATE
INTENSITY. BY 12Z THU...WINDS WILL BE LIGHT AND QUITE ANTICYCLONIC
OVER LAKE SUPERIOR AS THE HIGH CENTER IS JUST NW OF THE LAKE. EXPECT
DIMINISHING LES THROUGH WED NIGHT. HIGHEST SNOWFALL AMOUNTS FOR WED
THROUGH WED NIGHT LOOK TO BE E OF MUNISING NEAR LAKE SUPERIOR WITH
OVER 6 INCHES AND FROM ONTONAGON TO TWIN LAKES WITH OVER 5 INCHES.
ELSEWHERE NEAR LAKE SUPERIOR...EXPECT 2-4 INCHES.
THU...THE SFC HIGH WILL SHIFT E OF THE CWA THROUGH THE
DAY...REACHING THE LOWER GREAT LAKES BY 00Z FRI. THIS PUTS THE
REGION UNDER S-SE LOW LEVEL FLOW BEHIND THE HIGH AND AHEAD OF A
TROUGH AND SFC LOW THAT WILL BE OVER THE DAKOTAS AT 00Z FRI.
THU NIGHT AND FRI...SLY FLOW CONTINUES AS THE TROUGH/SFC LOW MOVES
TO SE MN BY 12Z FRI...CAUSING 850MB TEMPS TO WARM TO THE MID TEENS
BELOW ZERO. SHOULD SEE LAKE EFFECT/ENHANCED SNOW OFF LAKE MI AHEAD
OF THE SYSTEM...HELPING TO BOOST SNOWFALL TOTALS IN SCHOOLCRAFT AND
LUCE COUNTIES DEPENDING ON EXACT WIND DIRECTION. THE INVERTED TROUGH
N OF THE SFC LOW WILL MOVE TO THE CENTRAL CWA AROUND 18Z FRI...THEN
TO THE ERN CWA BY 00Z SAT. MODELS SHOW AROUND 0.2 INCHES OF SYNOPTIC
QPF...AND NEARLY DOUBLE THAT DOWNWIND OF LAKE MICHIGAN. LOOKING AT
MODEL PROFILES...THE BEST LIFT WILL BE ABOVE THE FAIRLY SHALLOW
DGZ...SO SNOW TO LIQUID RATIOS WILL PROBABLY NOT BE THAT HIGH. AT
THIS POINT IT LOOKS LIKE MOST LOCATIONS WILL SEE AROUND 3 INCHES OF
SNOW WITH POSSIBLY 6 INCHES DOWNWIND OF LAKE MICHIGAN.
A SHORTWAVE TROUGH LOOKS TO MOVE THROUGH LATE FRI INTO EARLY SAT
NIGHT...WHICH SHOULD HELP GIVE A BRIEF BOOST TO LES IN THE NNW LOW
LEVEL WINDS AND 850MB TEMPS AROUND -17C. ANY GOOD LES SHOULD NOT
LAST LONG AS A SFC HIGH RIDGE MOVES TO WRN LAKE SUPERIOR AND 850MB
TEMPS INCREASE TO AROUND -13C BY 18Z. LOW LEVEL FLOW ONCE AGAIN
BECOMES SELY BEHIND THE RIDGE SAT NIGHT WITH 850MB TEMPS INCREASING
TO A BALMY -5 OR SO BY 12Z SUN. FOR SUN AND MON...MODELS DO NOT HAVE
GOOD AGREEMENT...BUT THEY SUGGEST THAT A SHORTWAVE MAY MOVE
SOMEWHERE NEAR OR OVER THE AREA SUN OR SUN NIGHT. JUST USED A
CONSENSUS OF MODELS FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 630 AM EST TUE JAN 22 2013
KIWD...AS THE LLVL FLOW BACKS MORE TO THE WSW...EXPECT LINGERING LES
TO SHIFT TO THE N OF THIS LOCATION. SO MVFR/OCNL IFR CONDITIONS THIS
MRNG SHOULD GIVE WAY TO VFR CIGS DURING THE AFTN AND TNGT.
KCMX...EXPECT PREDOMINANT IFR CONDITIONS THRU THE DAY WITH UPSLOPE
WNW FLOW OF ARCTIC AIR/LES. CONDITIONS SHOULD DETERIORATE TO LIFR
TNGT AS AXIS OF SHARP CNVGC GETS SITUATED OVER THE KEWEENAW AND
ENHANCES LES INTENSITY IN PERSISTENT UPSLOPE FLOW.
KSAW...EXPECT PREDOMINANT VFR CONDITIONS THRU THIS FCST PERIOD WITH
DOWNSLOPE WSW FLOW OF DRY AIR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 AM EST TUE JAN 22 2013
EXPECT NW WINDS UP TO 20 TO 25 KTS THRU TONIGHT TO DRIVE ARCTIC AIR
OVER THE UPPER GREAT LAKES. THERE WILL BE PERIODS OF HEAVY FREEZING
SPRAY IN AREAS WHERE THE WINDS ARE STRONGEST. THE NW WINDS WILL
STRENGTHEN TO 25 TO 30 KTS ON WED FOLLOWING THE PASSAGE OF A
DISTRUBANCE...CAUSING MORE HEAVY FREEZING SPRAY THRU WED NIGHT. A
WEAKER PRES GRADIENT/LIGHTER WINDS AND SOME MODERATION OF THE CHILL
WILL END THE HEAVY FREEZING SPRAY BY THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001>003-
084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ085.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MIZ009.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST WEDNESDAY FOR MIZ006-007.
WIND CHILL ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR
MIZ004-005-010>014.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY
FOR LSZ240>251-263>267.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
THURSDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1029 AM EST TUE JAN 22 2013
.SYNOPSIS...
COLDER AIR WILL ARRIVE ON GUSTY WEST TO NORTHWEST WINDS THIS
MORNING...WHICH WILL ALLOW LAKE EFFECT SNOWS TO DEVELOP NORTH OF
THE NEW YORK THRUWAY. OUTSIDE OF THE LAKE EFFECT SNOW...PARTLY TO
MOSTLY CLOUDY SKIES AND SCATTERED SNOW SHOWERS OR FLURRIES ARE
EXPECTED. THIS ACTIVITY WILL DIMINISH ON WEDNESDAY AS THE NEXT
CLIPPER MOVES IN. HIGH PRESSURE WILL THEN BUILD IN ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1020 AM UPDATE...
INTERESTING MESO WX DAY CONTINUES. SWD MVMNT OF LES SNOW BAND ACRS
ERN LAKE ONTARIO HAS SLOWED OVER THE PAST HR...WITH FETCH BEING
SOMEWHAT REDUCED. THIS HAS RESULTED IN THE WEAKENING OF THE BAND
ACRS NRN ONEIDA COUNTY. THERE ARE SOME HINTS IN RDR REFLEECTIVITY
THAT A MESO-VORTEX MAY BE DVLPNG ALONG THE BAND JUST W OF ROC. 00Z
MESO MDLS WERE HINTING AT THIS DVLPMNT. THIS REMAINS A LOW
CONFIDENCE FCST...BUT WE THINK THE BAND WILL REMAIN PRETTY MUCH
WHERE IT IS UNTIL DROPPING SWD LATER THIS AFTN (MAYBE WITH THE
PSSG OF THE MESO-VORT). NAM12 AND RUC STILL INDICATE A QUICKER SWD
MVMNT OF THE BAND (18-29Z INTO NRN CWA) ALBIET IN A WEAKER STATE.
GIVEN THE UNCERTAINTY...NO CHGS WILL BE MADE TO THE CRNT FCST. WE
WILL RE-EVALUATE ALL HEADLINES WITH THE AFTN PCKG. THANX BUF FOR
COLLAB. PREV BLO...
850 AM UPDATE...
LAKE BAND HAS BEGUN TO SHOW A SWD DRIFT ACRS SRN LAKE
ONTARIO...WITH LTL MVMNT NOTED THUS FAR ACRS THE ERN SXNS. SOME
INDICATIONS IN THE MESO-MDLS THAT WE`LL SEE ANOTHER MESO-VORTEX
MOVG EWD ALONG THE BNDRY THIS AFTN. SIG DIFFS IN THE SHORT TERM
GDNC W/ RESPECT TO THE SWD MVMNT OF THE BNDRY...WITH ARW
SUGGESTING THE SLOWEST MVMNT...WITH RUC SUGGESTING IT OVG INTO TEH
SYR AREA BY 18Z. WE WILL CONTINUE TO MONITOR BUT ARE THINKNG THAT THE
SWD DRIFT WILL BE A BIT LATER THAN CRNTLY FCST (LOW
CONFIDENCE)...SO WARNINGS HAVE BEEN DELAYED TIL 18Z FOR
ONON/MAD/SRN ONEIDA. IF ARW IS CORRECT...EVEN THIS TIMING WILL BE
TOO SLOW. NEEDLESS TO SAY...AN INTERESTING MESO MET DAY.
ELSEWHERE...SCT -SHSN OFF LAKE ERIE ACRS TNE SRN TIER INTO NE PA.
PREV BLO...
330 AM UPDATE...
COMPLICATED SFC PATTERN ACRS THE AREA TONIGHT. SFC LOW ACRS SRN
ONTARIO IS SLIDING EAST ALONG STATIONARY FRONT LURKING FM THE MAINE
COAST WWD INTO THE MOHAWK VLY. THIS FRNT SEPARATES WEST WINDS ACRS
FAR NRN ZONES FM EAST-NORTHEAST WINDS OVR THE DACKS AND SRN CANADA.
LK EFFECT BAND THAT TRAVERSED THRU SYRACUSE AND HAS LIFTED NORTH
INTO ONEIDA CNTY LKLY DUE TO UL WVS TRAVERSING ACRS THE AREA. MAIN
PART OF THE LAKE BAND TOOK ON NORTH TO SOUTH CONFIGURATION AS IT
DRIFTED THRU ONONDAGA CNTY AND IS NOW BECOMING MORE SINGULAR IN
ORIENTATION.
WEST-SOUTHWEST FLOW IS OCCURRING NOW WITH UPSTREAM CONNECTION TO LK
HURON. HIRES AND NAM12 INDICATES SFC LOW WL HEAD EAST BY 12Z DUE TO
PRESSURE FALLS AND AS IT PASSES INTO THE DACKS WINDS SHUD TURN MORE
NWRLY AS IT DOES SO. THIS WL LKLY START TO SHIFT THE LK BAND JUST A
TAD FURTHER SOUTH INTO NRN ONEIDA CNTY. HV GONE CATEGORICAL FOR
ONEIDA CNTY BTWN 12Z-18Z FOR SNOW SHOWERS WITH OCNLY HEAVY SNOW. LK
EFFECT SNOW SQUALLS CAN BE EXPECTED ACRS NRN ZONES NORTH OF THE NEW
YORK THRUWAY WITH TOTALS THRU 00Z WED APPCHG A FOOT ACRS NWRN ONEIDA
CNTY. LK EFFECT SNOW WARNING APPEARS REASONABLE FOR ALL OF ONEIDA
CNTY TDA. EXTREME INSTABILITY WL BE PRESENT WITH LK-INDUCED CAPES >
1000 J/KG WITH INVERSION DEPTHS OF ARND 10KFT. THIS MAY PRODUCE
SNOWFALL RATES OF ARND 2 INCHES PER HR AT TIMES TDA.
HIRES MODELS INDICATE BAND WL BEGIN TO SLIP SOUTH AFT 18Z THIS AFTN
INTO ONONDAGA/MADISON CNTYS THO HOW FAR SOUTH RMNS TO BE SEEN. 6-HR
AMNTS OF 2-5 INCHES IN THESE CNTYS WL BE POSSIBLE BY 00Z WED.
AFTN MAXES EXPECTED TO RISE INTO THE LWR TEENS TDA AS COLD AIRMASS
RMNS LOCKED IN ACRS CWA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
330 AM UPDATE...
SNOW BAND WILL DROP FURTHER SOUTH OVRNGT WITH HVY SNOW INTO
ONONDAGA/MADISON CNTYS AND HV UPGRADED THESE CNTYS TO WARNINGS.
OVRNGT MINS WL DIP IN THE SINGLE DIGITS AND WITH WINDS ARND 10 MPH,
WIND CHILL VALUES WILL DIP BLO -15F TONIGHT FOR NY COUNTIES EAST OF
I-81. THUS HV OPTED TO ISSUE A WIND CHILL ADVISORY FOR THESE LOCALES
FROM 05Z TONIGHT THRU 15Z WED.
ANOTHER CLIPPER ON TAP FOR WEDNESDAY WITH SNOW EXPECTED ONCE AGAIN
WITH AMNTS BTWN 0.5 AND 1 INCH. TEMPS WL ONCE AGAIN BE IN THE TEENS
ON WEDNESDAY AS NRLY FLOW PROVIDES A STEADY FLOW OF CLD AIR FM
CANADA.
HIPRES BUILDS IN BRIEFLY FOR THURSDAY SHUTTING OFF PCPN AND ALLOWING
TEMPS TO WARM SEVERAL DEGREES ABV VALUES EARLY IN THE WEEK. NEXT
SYSTEM WL MV IN FRI MRNG BUT IS SLOW TO ARRIVE WITH HIPRES HOLDING
TIGHT TO CWA THRU 12Z.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MODELS SIMILAR. GRIDS LOOK GOOD. LITTLE CHANGE.
PREVIOUS DISCUSSION...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED.
INITIALLY A SOUTHERN STREAM SYSTEM WILL TRACK THROUGH THE MID
ATLANTIC REGION ON FRIDAY. THE ECMWF/CANADIAN IS MUCH FASTER THAN
THE GFS, LEANED TOWARD THE ECMWF ENSEMBLE WHICH IS A GOOD
COMPROMISE. THURSDAY NIGHT BACKED OFF ON POPS TO JUST CHC THEN
CHC/LIKELY ON FRIDAY WITH LIKELY POPS ACROSS THE SOUTHERN TIER AND
NE PA. MODELS INDICATE ALL SNOW WITH NO HINT OF ANY WARM LAYER.
BEHIND THIS WAVE THE UPPER LEVEL TROF WILL AMPLIFY OVER THE
NORTHEAST MAKING FOR A COLD WEEKEND WITH SCATTERED SNOW SHOWERS IN
NORTH/NORTHWEST FLOW. BY SUNDAY/MONDAY, UPPER LEVEL HEIGHTS RISE
WITH THE AIRMASS EXPECTED TO MODIFY UNDER SOUTHWEST FLOW.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
630 AM UPDATE...
A COLD WNW FLOW WILL CONTINUE TO GENERATE LAKE EFFECT SNOW. TWO
BANDS AFFECTING ALL SITES. THE STRONGER, A SINGLE BAND OF LAKE
EFFECT OFF OF LAKE ONTARIO WILL AFFECT ROME ALL MORNING INTO THE
AFTN. RME WILL HAVE IFR CONDITIONS AND ALTERNATE MINIMUM. THE
BAND WILL DROP FURTHER SOUTH TO SYR MIDDAY AGAIN WITH IFR
CONDITIONS AND BELOW ALTERNATE MINIMUM. THIS WILL LAST THERE INTO
THE EVENING.
THE SECOND BAND OFF OF LAKE ERIE IS NOT AS INTENSE AND NOT
CONTINUOUS. THIS HAS BEEN WAVERING ACROSS THE TWIN TIERS AND
AFFECTING MOSTLY ELM OF LATE BUT HAS GOTTEN AVP BGM ITH TOO. AGAIN
SOME IFR VSBYS BUT NOT SURE IF IT WILL CONTINUE AT THIS RATE.
MODEL FORECASTS ONLY SHOW WEAK LAKE EFFECT BUT HAVE UNDERDONE
EARLY THIS MORNING. FOR THIS PACKAGE ISSUED ONLY PUT A TEMPO FOR
MVFR AT ELM.
WEST WINDS AROUND 10 KTS EARLY THIS MORNING. INCREASING TO 10 TO
15 KTS WITH GUSTS TO 25 KTS BY 15Z CONTINUING UNTIL 23Z. WINDS
DROPPING TO 10 KTS AT 23Z.
.OUTLOOK...
WED...MVFR/IFR IN SNOW SHOWERS FOR KRME/KSYR OTHERWISE PRIMARILY
VFR.
THURSDAY/THURSDAY NIGHT...PRIMARILY VFR.
FRI... IFR CONDITIONS POSSIBLE IN SNOW.
FRIDAY NIGHT/SATURDAY...MVFR SNOW SHOWERS RESTRICTIONS LIKELY FOR
CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
WEDNESDAY FOR NYZ009-036-037-045-046-057-062.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST WEDNESDAY FOR NYZ018-
036-037.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST WEDNESDAY FOR NYZ009.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...RRM/TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
857 AM EST TUE JAN 22 2013
.SYNOPSIS...
COLDER AIR WILL ARRIVE ON GUSTY WEST TO NORTHWEST WINDS THIS
MORNING...WHICH WILL ALLOW LAKE EFFECT SNOWS TO DEVELOP NORTH OF
THE NEW YORK THRUWAY. OUTSIDE OF THE LAKE EFFECT SNOW...PARTLY TO
MOSTLY CLOUDY SKIES AND SCATTERED SNOW SHOWERS OR FLURRIES ARE
EXPECTED. THIS ACTIVITY WILL DIMINISH ON WEDNESDAY AS THE NEXT
CLIPPER MOVES IN. HIGH PRESSURE WILL THEN BUILD IN ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
850 AM UPDATE...
LAKE BAND HAS BEGUN TO SHOW A SWD DRIFT ACRS SRN LAKE
ONTARIO...WITH LTL MVMNT NOTED THUS FAR ACRS THE ERN SXNS. SOME
INDICATIONS IN THE MESO-MDLS THAT WE`LL SEE ANOTHER MESO-VORTEX
MOVG EWD ALONG THE BNDRY THIS AFTN. SIG DIFFS IN THE SHORT TERM
GDNC W/ RESPECT TO THE SWD MVMNT OF THE BNDRY...WITH ARW
SUGGESTING THE SLOWEST MVMNT...WITH RUC SUGGESTING IT OVG INTO TEH
SYR AREA BY 18Z. WE WILL CONTINUE TO MONITOR BUT ARE THINKNG THAT THE
SWD DRIFT WILL BE A BIT LATER THAN CRNTLY FCST (LOW
CONFIDENCE)...SO WARNINGS HAVE BEEN DELAYED TIL 18Z FOR
ONON/MAD/SRN ONEIDA. IF ARW IS CORRECT...EVEN THIS TIMING WILL BE
TOO SLOW. NEEDLESS TO SAY...AN INTERESTING MESO MET DAY.
ELSEWHERE...SCT -SHSN OFF LAKE ERIE ACRS TNE SRN TIER INTO NE PA.
PREV BLO...
330 AM UPDATE...
COMPLICATED SFC PATTERN ACRS THE AREA TONIGHT. SFC LOW ACRS SRN
ONTARIO IS SLIDING EAST ALONG STATIONARY FRONT LURKING FM THE MAINE
COAST WWD INTO THE MOHAWK VLY. THIS FRNT SEPARATES WEST WINDS ACRS
FAR NRN ZONES FM EAST-NORTHEAST WINDS OVR THE DACKS AND SRN CANADA.
LK EFFECT BAND THAT TRAVERSED THRU SYRACUSE AND HAS LIFTED NORTH
INTO ONEIDA CNTY LKLY DUE TO UL WVS TRAVERSING ACRS THE AREA. MAIN
PART OF THE LAKE BAND TOOK ON NORTH TO SOUTH CONFIGURATION AS IT
DRIFTED THRU ONONDAGA CNTY AND IS NOW BECOMING MORE SINGULAR IN
ORIENTATION.
WEST-SOUTHWEST FLOW IS OCCURRING NOW WITH UPSTREAM CONNECTION TO LK
HURON. HIRES AND NAM12 INDICATES SFC LOW WL HEAD EAST BY 12Z DUE TO
PRESSURE FALLS AND AS IT PASSES INTO THE DACKS WINDS SHUD TURN MORE
NWRLY AS IT DOES SO. THIS WL LKLY START TO SHIFT THE LK BAND JUST A
TAD FURTHER SOUTH INTO NRN ONEIDA CNTY. HV GONE CATEGORICAL FOR
ONEIDA CNTY BTWN 12Z-18Z FOR SNOW SHOWERS WITH OCNLY HEAVY SNOW. LK
EFFECT SNOW SQUALLS CAN BE EXPECTED ACRS NRN ZONES NORTH OF THE NEW
YORK THRUWAY WITH TOTALS THRU 00Z WED APPCHG A FOOT ACRS NWRN ONEIDA
CNTY. LK EFFECT SNOW WARNING APPEARS REASONABLE FOR ALL OF ONEIDA
CNTY TDA. EXTREME INSTABILITY WL BE PRESENT WITH LK-INDUCED CAPES >
1000 J/KG WITH INVERSION DEPTHS OF ARND 10KFT. THIS MAY PRODUCE
SNOWFALL RATES OF ARND 2 INCHES PER HR AT TIMES TDA.
HIRES MODELS INDICATE BAND WL BEGIN TO SLIP SOUTH AFT 18Z THIS AFTN
INTO ONONDAGA/MADISON CNTYS THO HOW FAR SOUTH RMNS TO BE SEEN. 6-HR
AMNTS OF 2-5 INCHES IN THESE CNTYS WL BE POSSIBLE BY 00Z WED.
AFTN MAXES EXPECTED TO RISE INTO THE LWR TEENS TDA AS COLD AIRMASS
RMNS LOCKED IN ACRS CWA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
330 AM UPDATE...
SNOW BAND WILL DROP FURTHER SOUTH OVRNGT WITH HVY SNOW INTO
ONONDAGA/MADISON CNTYS AND HV UPGRADED THESE CNTYS TO WARNINGS.
OVRNGT MINS WL DIP IN THE SINGLE DIGITS AND WITH WINDS ARND 10 MPH,
WIND CHILL VALUES WILL DIP BLO -15F TONIGHT FOR NY COUNTIES EAST OF
I-81. THUS HV OPTED TO ISSUE A WIND CHILL ADVISORY FOR THESE LOCALES
FROM 05Z TONIGHT THRU 15Z WED.
ANOTHER CLIPPER ON TAP FOR WEDNESDAY WITH SNOW EXPECTED ONCE AGAIN
WITH AMNTS BTWN 0.5 AND 1 INCH. TEMPS WL ONCE AGAIN BE IN THE TEENS
ON WEDNESDAY AS NRLY FLOW PROVIDES A STEADY FLOW OF CLD AIR FM
CANADA.
HIPRES BUILDS IN BRIEFLY FOR THURSDAY SHUTTING OFF PCPN AND ALLOWING
TEMPS TO WARM SEVERAL DEGREES ABV VALUES EARLY IN THE WEEK. NEXT
SYSTEM WL MV IN FRI MRNG BUT IS SLOW TO ARRIVE WITH HIPRES HOLDING
TIGHT TO CWA THRU 12Z.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MODELS SIMILAR. GRIDS LOOK GOOD. LITTLE CHANGE.
PREVIOUS DISCUSSION...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED.
INITIALLY A SOUTHERN STREAM SYSTEM WILL TRACK THROUGH THE MID
ATLANTIC REGION ON FRIDAY. THE ECMWF/CANADIAN IS MUCH FASTER THAN
THE GFS, LEANED TOWARD THE ECMWF ENSEMBLE WHICH IS A GOOD
COMPROMISE. THURSDAY NIGHT BACKED OFF ON POPS TO JUST CHC THEN
CHC/LIKELY ON FRIDAY WITH LIKELY POPS ACROSS THE SOUTHERN TIER AND
NE PA. MODELS INDICATE ALL SNOW WITH NO HINT OF ANY WARM LAYER.
BEHIND THIS WAVE THE UPPER LEVEL TROF WILL AMPLIFY OVER THE
NORTHEAST MAKING FOR A COLD WEEKEND WITH SCATTERED SNOW SHOWERS IN
NORTH/NORTHWEST FLOW. BY SUNDAY/MONDAY, UPPER LEVEL HEIGHTS RISE
WITH THE AIRMASS EXPECTED TO MODIFY UNDER SOUTHWEST FLOW.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
630 AM UPDATE...
A COLD WNW FLOW WILL CONTINUE TO GENERATE LAKE EFFECT SNOW. TWO
BANDS AFFECTING ALL SITES. THE STRONGER, A SINGLE BAND OF LAKE
EFFECT OFF OF LAKE ONTARIO WILL AFFECT ROME ALL MORNING INTO THE
AFTN. RME WILL HAVE IFR CONDITIONS AND ALTERNATE MINIMUM. THE
BAND WILL DROP FURTHER SOUTH TO SYR MIDDAY AGAIN WITH IFR
CONDITIONS AND BELOW ALTERNATE MINIMUM. THIS WILL LAST THERE INTO
THE EVENING.
THE SECOND BAND OFF OF LAKE ERIE IS NOT AS INTENSE AND NOT
CONTINUOUS. THIS HAS BEEN WAVERING ACROSS THE TWIN TIERS AND
AFFECTING MOSTLY ELM OF LATE BUT HAS GOTTEN AVP BGM ITH TOO. AGAIN
SOME IFR VSBYS BUT NOT SURE IF IT WILL CONTINUE AT THIS RATE.
MODEL FORECASTS ONLY SHOW WEAK LAKE EFFECT BUT HAVE UNDERDONE
EARLY THIS MORNING. FOR THIS PACKAGE ISSUED ONLY PUT A TEMPO FOR
MVFR AT ELM.
WEST WINDS AROUND 10 KTS EARLY THIS MORNING. INCREASING TO 10 TO
15 KTS WITH GUSTS TO 25 KTS BY 15Z CONTINUING UNTIL 23Z. WINDS
DROPPING TO 10 KTS AT 23Z.
.OUTLOOK...
WED...MVFR/IFR IN SNOW SHOWERS FOR KRME/KSYR OTHERWISE PRIMARILY
VFR.
THURSDAY/THURSDAY NIGHT...PRIMARILY VFR.
FRI... IFR CONDITIONS POSSIBLE IN SNOW.
FRIDAY NIGHT/SATURDAY...MVFR SNOW SHOWERS RESTRICTIONS LIKELY FOR
CENTRAL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
WEDNESDAY FOR NYZ009-036-037-045-046-057-062.
LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
WEDNESDAY FOR NYZ018-036-037.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST WEDNESDAY FOR NYZ009.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...RRM/TAC
AVIATION...TAC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
829 AM MST TUE JAN 22 2013
.UPDATE...15Z SURFACE ANALYSIS HAD WARM FRONT FROM EAST CENTRAL MT
TO THE NE PANHANDLE. 12Z KUNR SOUNDING SHOWED STRONG INVERSION
WITH WARM AIR NOT FAR FROM THE SURFACE OVER THE HIGHER ELEVATIONS.
AS UPPER RIDGE OVER THE WEST INCHES EAST TODAY...WARM FRONT SHOULD
MAKE SOME PROGRESS INTO THE FAR WESTERN SD PLAINS. SHARP
TEMPERATURE GRADIENT EXPECTED BY AFTERNOON. 12Z RAP AS WELL AS
BUFKIT MOMENTUM TRANSFER GUIDANCE SUGGESTS A FEW BREEZY/GUSTY
SPOTS OVER NORTHEAST WY/HIGHER ELEVATIONS OF THE BLACK HILLS FOR
THIS AFTERNOON...SO HAVE ADJUSTED ACCORDINGLY. REST OF FORECAST IN
GOOD SHAPE.
&&
.AVIATION...12Z TAFS
FLURRIES OVER NORTHWEST INTO CENTRAL SOUTH DAKOTA WILL CONTINUE
TO MOVE EAST OUT OF THE AREA THIS MORNING. OTHERWISE VFR
CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 256 AM MST TUE JAN 22 2013/
DISCUSSION...STAUNCH WESTERN CONUS RIDGE CONTINUES TO SLOWLY PUSH
EAST...HOWEVER...THE ENTRENCHED ARCTIC AIR MASS IS REFUSING TO EXIT
EASY. ANOTHER STRONG COMPACT FAST MOVING MID LEVEL IMPULSE IS DIVING
SE ACROSS MB...AND WILL HELP REINFORCE THE CURRENT AIR MASS ACROSS
THE NORTHERN PLAINS. OTHERWISE...WAA IS ONGOING ACROSS THE
REGION...WITH VERY WARM TEMPS IN PLACE ACROSS NE WY AND THE BH PER A
DECENTLY MIXED BL. LIGHT SNOW/FLURRIES CONTINUE OVER THE EASTERN FA
PER THE WAA INDUCED UPGLIDE...WITH THIS AREA CONTINUING TO SHIFT
EAST. OTHERWISE....A RATHER STRONG NE PAC UPPER TROUGH IS ADVANCING
INTO THE WESTERN NOAM RIDGE AND WILL EVENTUALLY SPAWN A CLIPPER
SYSTEM INTO THE REGION...AFFECTING THE LOCAL AREA WED INTO THUR.
STRONG TEMP GRADIENT WILL CONTINUE ACROSS THE FA TODAY...WITH HIGHS
NEAR 50 IN NE WY TO THE LOWER 20S OVER THE EAST. SFC WARM FRONT WILL
STRUGGLE EAST OFF THE HIGHER TERRAIN GIVEN A RATHER STRONG WAA
INVERSION IN PLACE AND RELATIVELY POOR LL FLOW TO SUPPORT MIXING.
CONTINUED LIGHT SNOW SHOWER CHANCES THIS MORNING ACROSS THE FAR
EAST...WITH DRY CONDITIONS THIS AFTERNOON ALL PLACES. AMPLE
SUNSHINE EXPECTED WESTERN AREAS...WITH FGEN CLOUDS LINGERING OVER
THE EAST THROUGH MUCH OF THE DAY. LL FLOW WILL BEGIN TO RESPOND TO
THE ADVECTING NW CONUS UPPER IMPULSE WED...WITH SFC PRESSURE FALLS
UPTICKING OVER NE WY. MEANWHILE...TODAY/S MB TROUGH WILL SUPPORT A
COLD PUSH ACROSS THE EASTERN NORTHERN PLAINS TONIGHT...WHICH WILL
SETTLE WEST INTO THE FA GIVEN SFC PRESSURE FALLS IN THE LEE OF THE
ROCKIES SUPPORTING EASTERLY FLOW. FORECAST MODELS HAVE TRENDED
MUCH COLDER PER TEMPS OVER THE EASTERN 2/3 OF THE FA WED...AND
HAVE CUT HIGHS SIG FOR THIS. UPSLOPE COMPONENT TO THE FLOW
CERTAINLY WILL NOT HELP THINGS EITHER. LL EASTERLY UPSLOPE
/SUFFICIENTLY MOIST/ FLOW MAY SUPPORT LOW CLOUDS OVER THE SD
PLAINS BY WED AFTERNOON/EVENING...WITH FOG POSSIBLE OVER THE
EASTERN BH FOOTHILLS BY EVENING. HAVE INTRODUCED A PATCHY FOG
MENTION FOR THIS. MEANWHILE NE WY AND THE BH WILL REMAIN QUITE
WARM...AS THE LL COLD AIR MASS WILL REMAIN SHALLOW AND CONFINED TO
LOWER TERRAIN. KEPT WARM TEMPS IN THIS REGION THROUGH WED. CLIPPER
SYSTEM WILL SHIFT WINDS WESTERLY OVER THE ENTIRE FA THUR...WITH BL
WARM DOWNSLOPE FLOW EXPECTED TO MIX DOWN AT MOST PLACES...ESP THE
SW 3/4. HAVE CUT BACK ON POPS WITH THIS SYSTEM GIVEN LACK OF
APPRECIABLE MOISTURE WITH BEST LL AND MID LEVEL FORCING EXPECTED
TO REMAIN NORTH OF THE FA. REMOVED POPS WED NIGHT AND RETAINED A
LOW CHANCE MENTION ACROSS THE NORTH THUR. PERHAPS THE MAIN IMPACT
FROM THIS SYSTEM WILL BE WINDS ON THE BACKSIDE OF THIS SYSTEM THUR
AFTERNOON AND EVENING. DECENT PRESSURE RISE/CAA COMBO SHOULD
SUPPORT ADV TO NEAR ADV CRITERIA FOR MUCH OF NW SD. COLD AIR WILL
FILTER BACK INTO MUCH OF THE AREA THUR NIGHT...WITH WINDS SLOWLY
SUBSIDING.
EXTENDED...RIDGE OVER THE WRN CONUS WILL SLOWLY SHIFT EAST ACROSS
THE NORTHERN PLAINS THROUGH THE WEEKEND...BRINGING MILD AND DRY
CONDITIONS. MODELS START TO DIVERGE ON A SOLUTION TO START NEXT WEEK
THOUGH OVERALL PATTERN REMAINS UNSETTLED...SO WILL LEAVE LOW POPS IN
FOR NOW.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...HELGESON
LONG TERM...WFO UNR
AVIATION...WFO UNR
UPDATE...WFO UNR
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
645 AM EST TUE JAN 22 2013
.SYNOPSIS...
HIGH PRESSURE WITH VERY COLD AIR WILL COVER THE AREA TODAY AND
WEDNESDAY. A LOW PRESSURE SYSTEM WILL MOVE FROM THE PLAINS ON
THURSDAY INTO THE OHIO VALLEY AND MID ATLANTIC REGION ON FRIDAY.
HIGH PRESSURE AND MORE COLD AIR IS EXPECTED SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM EST TUESDAY...
A COUPLE OF WEAK SHORT WAVES AND STRING UPSLOPE IN EASTERN WET
VIRGINIA HAVE SQUEEZED ENOUGH LOW LEVEL MOISTURE OUT OF THIS
ARCTIC AIRMASS FOR LOW CLOUDS ALONG THE WESTERN SLOPES OF THE
MOUNTAINS FROM GREENBRIER COUNTY NORTH INTO CENTRAL PENNSYLVANIA.
AREA NATIONAL WEATHER SERVICE RADARS SHOWED ONLY MINIMAL SHOW
SHOWER COVERAGE IN SOUTHEAST WEST VIRGINIA.
SUBTLE SHORT WAVES WILL CONTINUE TO ROTATE THROUGH THE LONG WAVE
THROUGH TODAY AND TONIGHT. THE RUC AND OOZE WRF SUGGEST THE LOWER
CLOUDS MAY EXPAND SOUTH TO BLUEFIELD AND TAZEWELL COUNTY THIS
MORNING. OTHERWISE AS A JET STREAK CROSSES THE FORECAST AREA
EXPECT MOUNTAIN CIRRUS ON THE EAST SLOPES OF THE CENTRAL AND
SOUTHERN APPALACHIANS THIS EVENING. HAVE ADJUSTED CLOUD COVER
FORECAST FOR THESE TRENDS.
AIR MASS UPSTREAM AT 00Z HAD 850 MB TEMPERATURES FROM -15 TO -20
AND SURFACE DEW POINTS WELL BELOW ZERO. HAVE GONE COLDER THAN
GUIDANCE FOR BOTH HIGHS TODAY AND LOWS TONIGHT.
SURFACE PRESSURE CONTINUES TO RISE TODAY AND BY WEDNESDAY MORNING
THE CENTER OF THE HIGH WILL BE OVER EASTERN TENNESSEE. WIND WILL
BEGIN TO DIMINISH THIS MORNING AND WILL BE MUCH LIGHTER IN THE
VALLEYS TONIGHT. AT THE HIGHER ELEVATIONS OF BATH...GREENBRIER AND
ALLEGHANY VIRGINIA...WIND CHILLS STAY CLOSE TO THE ZERO TO -5
RANGE DESPITE THE DECREASING WIND SPEEDS. HAVE EXTENDED THE WIND
CHILL ADVISORY IN THESE COUNTIES THROUGH WEDNESDAY MORNING.
ANOTHER ADVISORY MADE BE NEEDED FOR LATE TONIGHT FOR THE WESTERN
PART OF THE FORECAST AREA.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EST TUESDAY...
COMPLEX FORECAST FOR THE LATER HALF OF THE WEEK. ARCTIC AIR WILL BE
FIRMLY ENTRENCHED ACROSS THE FORECAST AREA EARLY WEDNESDAY MORNING.
UPPER TROUGH/POLAR VORTEX OVER ERN CANADA WILL MOVE VERY LITTLE FROM
WEDNESDAY THROUGH FRIDAY...ALTHOUGH WILL SEE BRIEF RETREAT OF
COLDEST AIR WEDNESDAY AND AGAIN FRIDAY AHEAD OF TWO SEPARATE SHORT
WAVES THAT WILL CROSS THE REGION DURING THIS TIME FRAME.
THE FIRST WAVE WILL MOVE THROUGH THE GREAT LAKES AND ALONG THE MASON-
DIXON WEDNESDAY NIGHT. THIS WILL CAUSE WINDS TO BACK WITH
DEVELOPMENT OF ISENTROPIC LIFT ACROSS THE OHIO VALLEY WEDNESDAY...
THIS AREA OF FORCING SCOOTING BY TO OUR NORTH WEDNESDAY NIGHT. AT
THE VERY LEAST SHOULD SEE INCREASING CLOUDINESS WEDNESDAY...CLOUDS
THICKENING PRIOR TO THE PASSAGE OF THE SHORTWAVE WEDNESDAY NIGHT. A
BRIEF PERIOD OF LIGHT SNOW OR FLURRIES IS POSSIBLE...BUT MAINLY FOR
THE WV MTNS AND VA HIGHLANDS. FORECAST BUFKIT SOUNDINGS INDICATE
LITTLE IN THE WAY OF PRECIP REACHING THE GROUND PER VERY DRY AIRMASS
OVER THE FCST AREA. AS SUCH...RUNNING WITH VERY LOW POPS WEDNESDAY
NIGHT WITH LITTLE (UPWARDS OF AN INCH IN NW GREENBRIER?) OR NO SNOW
ACCUMULATION. PASSAGE OF THIS WAVE WILL BRING REINFORCING SURGE OF
ARCTIC AIR TO THE AREA THURSDAY.
THE SECOND SHORT WAVE IS FORECAST TO DIP A BIT FARTHER SOUTH...
TAPPING RIBBON OF GULF MOISTURE FOR FRIDAY. AREA OF ISENTROPIC LIFT
IS FORECAST TO PASS ALMOST DIRECTLY OVHD WITH ENOUGH LIFT TO
GENERATE UPWARDS OF A THIRD OF AN INCH OF QPF. THE SUBFREEZING
ANTECEDENT CONDITIONS SUGGEST WE WILL BE LOOKING AT P-TYPE ISSUES
WITH POTENTIAL FOR BOTH FREEZING AND FROZEN PRECIPITATION
AREAWIDE...AND COVERING A LARGE GEOGRAPHIC SWATH FROM THE OHIO
VALLEY EASTWARD THROUGH THE MID ATLANTIC AND POINTS NORTH. FOR OUR
CWA...ESP THE SOUTHERN HALF...MODEL FORECAST SOUNDINGS INDICATE WARM
NOSE (+1 TO +3 DEG C) VCNTY OF 800 MB TO OVERRIDE THE SHALLOW BUT
VERY COLD BOUNDARY LAYER. LATEST MODELS HAVE TRENDED COLDER WITH
THIS SYSTEM SUGGESTING A GOOD PORTION OF THE QPF MAY BE SNOW OR
SLEET B4 CHANGING TO FREEZING RAIN. ATTM THINK WE WILL BE LOOKING
AT WINTER WEATHER ADVISORY CONDITIONS FRIDAY. WOULD NEED A BIT MORE
QPF...OR...FOR ALL OF THE PRECIP TO FALL AS FREEZING RAIN IN ORDER
TO JUSTIFY A WATCH/WARNING SORT OF CONCERN. AT THE VERY
LEAST...THIS WILL BE A CONCERN FOR SCHOOLS/DOT/TRAVEL INTERESTS AS
THE GROUND WILL BE FROZEN ALLOWING FOR EASY ACCUMULATION FOR
WHATEVER WINTER PTYPE OCCURS.
TEMPERATURES THROUGH THE END OF THE WEEK WILL STRUGGLE TO REACH
FREEZING. EVEN FOR AREAS THAT MANAGE TO GET ABOVE FREEZING...THE
WETBULB WILL REMAIN BELOW 32. THIS SUGGESTS THE REMAINING SNOW
COVER IN THE MOUNTAINS IS NOT GOING ANYWHERE FOR THE REST OF THIS
WEEK.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 400 AM EST TUESDAY...
ANY WARM AIR THAT TRIES TO DISPLACE THE COLD AIR FRIDAY WILL GET
SQUASHED BY SATURDAY. NORTHWEST WINDS ARE FORECAST TO DEVELOP IN
THE WAKE OF FRIDAYS SYSTEM...85H TEMPS DIPPING BACK DOWN TO NEAR M15
BY SATURDAY MORNING. THIS SAME NORTHWEST FLOW WILL RESULT IN
PERSISTENT CLOUDS/-SHSN/FLURRIES OVER THE MOUNTAINS WITH DRY BUT
BRISK CONDITIONS ELSEWHERE.
SUNDAY WILL BRING TRANSITION BACK TO SUNNY SKIES...WINDS
DIMINISHING...1035 MB HIGH PRESSURE PASSING OVERHD. A WARMING TREND
IS EXPECTED TO GET UNDERWAY FOR THE FOLLOWING WEEK AS SOUTHERLY WINDS
DEVELOP AROUND THE DEPARTING ANTICYCLONE...TEMPERATURES TRENDING
BACK ABOVE NORMAL. THE PATTERN ALSO LOOKS WET...WIND FLOW COMING
UP FROM THE GULF COAST REGION.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 630 AM EST TUESDAY...
SATELLITE PICTURES SHOWED A SMALL PERSISTENT PATCH OF VFR CLOUDS
IN WESTERN GREENBRIER COUNTY THIS MORNING. EXPECT THIS CLOUD COVER
TO STAY WEST OF LWB TODAY. UPPER JET CROSSING THE SOUTHERN
APPALACHIANS THIS EVENING MAY PRODUCE A SCT TO BKN LAYER OF CIRRUS
EAST OF THE APPALACHIANS TONIGHT. HIGH CONFIDENCE THAT
BLF/LWB/BCB/ROA/LYH AND DAN WILL BE VFR THROUGH THE TAF FORECAST
PERIOD.
WINDS WILL BE GUSTY FROM 290 TO 310 TODAY WITH WIND SPEEDS
GRADUALLY DIMINISHING AFTER NOON. AS SURFACE HIGH PRESSURE BUILDS
IN TO THE AREA TONIGHT...WINDS WILL DECOUPLE IN THE WEST
VALLEYS...INCLUDING AT LWB...BECOMING CALM TO LIGHT AND VARIABLE.
ISENTROPIC LIFT AHEAD A DEVELOPING LOW PRESSURE SYSTEM TRACKING
FROM THE PLAINS TO THE TENNESSEE VALLEY ON THURSDAY WILL SPREAD
CLOUDS COVER ACROSS THE REGION BY THURSDAY NIGHT. MODELS HAVE
SLOWED DOWN ARRIVAL OF THE PRECIPITATION WITH MOST GUIDANCE
HOLDING OFF UNTIL AFTER 12Z/7AM FRIDAY. SOME FORM OF WINTER
PRECIPITATION IS LIKELY BUT THE CONFIDENCE ON WHICH PRECIPITATION
TYPE IS LOW. AT THIS TIME THE MOST LIKELY IS FOR SLEET AND
FREEZING RAIN WITH IFR CEILINGS ON FRIDAY.
AS THIS SYSTEM MOVES OFFSHORE BY SATURDAY MORNING...WIND GUST TO
30 KTS ARE POSSIBLE. CEILINGS AND POSSIBLY VISIBILITIES WILL
REMAIN MVFR WITH SNOW SHOWERS AT BLF AND LWB THROUGH FRIDAY
NIGHT..BUT WILL BE VFR AT ROA/DAN/LYH FRIDAY NIGHT AND SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR VAZ007-009>018-
023-024.
WIND CHILL ADVISORY UNTIL NOON EST WEDNESDAY FOR VAZ019-020.
NC...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR NCZ001-002-018.
WV...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR WVZ042>044.
WIND CHILL ADVISORY UNTIL NOON EST WEDNESDAY FOR WVZ045.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PM
LONG TERM...PM/RCS
AVIATION...AMS/PM
AREA FORECAST DISCUSSION
NWS ALBANY NY
144 PM EST TUE JAN 22 2013
.SYNOPSIS...
COLD TEMPERATURES WILL CONTINUE THROUGH THE UPCOMING WORK
WEEK...AS AN ARCTIC AIR MASS SETTLES OVER THE REGION. BITTER COLD IS
EXPECTED ACROSS THE REGION TODAY THROUGH THURSDAY. LOW PRESSURE MAY BRING
WIDESPREAD SNOW TO THE REGION ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 130 PM...POLAR VORTEX CONTUINUES TO SPIN ACROSS AREA. -41C
AT 500MB ON RUC ANALYSIS. KENX VAD WIND PROFILE SHOWS 15-30KTS WIND
BETWEEN 2000 AND 7000 FEET MSL...SO CONTINUED BREEZY CONDITIONS EXPECTED.
SUNS RADIATION COMBINED WITH COLD AIR ALOFT HAS LED TO CONVECTIVE
CLOUDS COVERING A GOOD PART OF AREA. LAKE EFFECT BAND ALSO NOW
POINTED RIGHT DOWN MOHAWK VALLEY...BUT VERY WEAK RETURNS...SO
LIGHT SNOW AT WORST SOUTHERN HERKIMER COUNTY WITH FLURRIES FURTHER
SOUTHEAST. TEMPS ARE COLD WITH SINGLE DIGITS IN THE HIGHER TERRAIN
TO AROUND 20 IN THE HUDSON VALLEY. LITTLE CHANGE EXPECTED THROUGH SUNSET.
THIS UPDATE CONTAINS COMPLETE REFRESH OF DATABASE THROUGH 7 AM
FRIDAY MORNING. FIRE WEATHER GRIDS ALSO UPDATED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
WIND CHILL ADVISORIES AND WARNINGS ARE IN EFFECT FOR TONIGHT AND
WEDNESDAY. WIND CHILL VALUES WILL VARY CONSIDERABLY FROM LOCATION TO
LOCATION...AND NOT ALL AREAS WITHIN EACH COUNTY WILL SEE THE WIND
CHILLS REACH ADVISORY OR WARNING CRITERIA.
LAKE EFFECT SNOW SHOWER ACTIVITY SHOULD CONTINUE TONIGHT...THEN
GRADUALLY DIMINISH WEDNESDAY THROUGH WEDNESDAY NIGHT. SOURCES OF
GUIDANCE SUGGEST BOUNDARY LAYER WINDS STAY RELATIVELY STRONG AND
SHOULD MIX TO THE SURFACE PERIODICALLY THROUGH TONIGHT...
ESPECIALLY IN HIGHER ELEVATIONS AND THROUGH THE MOHAWK VALLEY WITH
CHANNELING EFFECTS.
WIND CHILL WARNINGS IN EFFECT FOR THE SOUTHERN ADIRONDACKS. WIND
CHILLS SHOULD RISE TO ADVISORY RANGE THROUGH WEDNESDAY MORNING FOR
THE SOUTHERN ADIRONDACKS..BUT TO AVOID CONFUSION...JUST KEEPING
THE ONE HEADLINE AND EXPLAINING THE WIND CHILL TRENDS IN THE WSW.
WIND CHILL ADVISORIES IN EFFECT FOR THE WESTERN MOHAWK
VALLEY...SCHOHARIE VALLEY...EASTERN CATSKILLS...LAKE GEORGE AND
NORTHERN SARATOGA REGION...SOUTHERN VERMONT AND WESTERN
MASSACHUSETTS. THE WIND CHILLS SHOULD RISE OUT OF WIND CHILL
ADVISORY CRITERIA BY NOON WEDNESDAY...EVEN WITH POTENTIALLY BREEZY
CONDITIONS AT TIMES THROUGH THE DAY. THERE COULD BE ADDITIONAL WIND
CHILL HEADLINES NEEDED WEDNESDAY NIGHT...BUT WILL TREAT THAT AS A
SEPARATE EVENT IF NECESSARY AND THOSE DECISIONS WILL BE MADE LATER
TODAY OR TONIGHT.
TEMPERATURES ARE A LITTLE TRICKY. WITH SUCH AN ARCTIC AIR MASS...
USUALLY TEMPERATURES FALL BELOW GUIDANCE VALUES THROUGH THE
PERIOD. HOWEVER...WITH STEADY AND RELATIVELY STRONG BOUNDARY LAYER
WEST TO NORTHWEST FLOW...WITH WINDS OCCASIONALLY MIXING DOWN...
EVEN AT NIGHT...MIXING COULD PREVENT TEMPERATURES FROM BEING AS
COLD AS THEY COULD BE. ALSO...CENTER OF THE SURFACE HIGH PRESSURE
QUITE A DISTANCE WEST OF OUR REGION AND MAXIMUM SUBSIDENCE MAY NOT
AFFECT OUR REGION UNTIL LATE WEDNESDAY NIGHT...THURSDAY AND
THURSDAY NIGHT. IN ADDITION...INLAND EXTENT OF LAKE EFFECT CLOUDS
IN QUESTION...WHICH CAN PREVENT TEMPERATURES FROM BEING AS COLD AS
THEY COULD BE. ALSO...NOT MUCH SNOW PACK TO AID IN STEEP
TEMPERATURE DROPS.
WITH THESE UNCERTAINTIES...STAYING CLOSE TO COLDEST GUIDANCE BUT
NOT READY TO GO MUCH BELOW GUIDANCE THROUGH THE PERIOD UNTIL THE
EXTENT OF THE WINDS AND LAKE EFFECT CLOUDS CAN BE DETERMINED
BEYOND TODAY AND TONIGHT. STILL...WE CAN EXPECT THE COLDEST AIR
OF THE WINTER SO FAR.
HIGHS IN THE TEENS WEDNESDAY....WITH SINGLE NUMBER IN HIGHER
ELEVATIONS. HIGHS THURSDAY JUST A FEW DEGREES WARMER THAN
WEDNESDAY...IF THAT...DEPENDING ON WHETHER BOUNDARY LAYER
TEMPERATURES CAN WARM A DEGREE OR TWO. LOWS WELL BELOW ZERO IN
NORTHERN AREAS AND HIGHER ELEVATIONS...ZERO TO 10 IN THE
HUDSON RIVER VALLEY AND SOUTHERN AREAS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE MAIN FORECAST CHALLENGE FOR THE PERIOD IS A POSSIBLE LIGHT TO
MODERATE SNOW EVENT FOR MUCH OF THE FORECAST AREA FRIDAY THROUGH
FRIDAY NIGHT. VARIOUS SOURCES OF MODEL GUIDANCE HAVE SHOWN
DIFFERENCES AMONG EACH OTHER AND WITHIN THEMSELVES FROM RUN TO RUN.
WILL LEAN MORE TOWARDS THE ECMWF/GGEM CAMP AND AWAY FROM THE GFS FOR
THIS FORECAST. THE GFS HAS BEEN MORE INCONSISTENT AND IS NOW
DEPICTING MORE OF A WEAKER NORTHERN STREAM SYSTEM MOVING ACROSS THE
GREAT LAKES AND NORTHEAST...WHILE THE ECMWF/GGEM INDICATE SOUTHERN
STREAM ENERGY EMERGING FROM THE TENNESSEE/OHIO VALLEY REGIONS AND
POSSIBLY PHASING INTO A STRONGER SYSTEM NEAR THE SOUTHERN NEW
ENGLAND COAST. THE LATEST ECMWF HAS A NEW WRINKLE IN THAT IS HAS
EXPLOSIVE CYCLOGENESIS OCCURRING SATURDAY MORNING. SHOULD THE ECMWF
SOLUTION OCCUR...WE WOULD BE DEALING WITH A HEAVIER SNOW EVENT.
HOWEVER...THERE ARE QUITE A FEW VARIABLES TO CONSIDER AT THIS
TIME. ALL INDICATIONS ARE FOR AT LEAST THE SAME PTYPE OF SNOW
WITH TEMPS CONTINUED COLD.
STILL PLENTY OF TIME TO SORT OUT THE DETAILS...AND IT NOW LOOKS LIKE
ONSET OF SNOW WOULD BE DELAYED UNTIL FRIDAY AFTERNOON. WITH
UNCERTAINTY IN THE DEGREE/POSITION OF COASTAL DEVELOPMENT...HAVE
PAINTED THE HIGHEST POPS ACROSS SOUTHERN AREAS. WILL LINGER CHANCE
POPS INTO SATURDAY NOW FOR THE POSSIBILITY OF A STRONGER AND SLOWER
CYCLONE.
MODELS ARE IN GOOD AGREEMENT SHOWING DRY N-NW FLOW BEHIND THE
DEPARTING SYSTEM FOR SATURDAY NIGHT INTO SUNDAY WITH BRISK WINDS AND
CONTINUED BELOW NORMAL TEMPERATURES. IT LOOKS LIKE THE SURFACE RIDGE
WILL GRADUALLY MOVE ACROSS THE AREA THROUGH EARLY NEXT WEEK WITH A
MODERATING TREND. TEMPERATURES MAY WARM BACK TO NORMAL BY MONDAY.
THERE DOES NOT APPEAR TO BE MUCH OF A CHANCE FOR ANY PRECIP DURING
THIS TIME WITH HIGH PRESSURE MAINLY IN CONTROL.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD ENDING AT 18Z ON
WEDNESDAY.
SCT-BKN STRATOCU CLOUDS FROM LAKE EFFECT ACTIVITY WELL TO THE WEST
WILL WANDER ACROSS THE REGION THROUGH THE EVENING HOURS. WHILE NO
SNOW SHOWERS ARE EXPECTED AT THE TERMINALS...SOME LEFT OVER CLOUDS
WILL OCCUR FROM TIME TO TIME. IN ADDITION...W-NW WINDS WILL BE GUSTY
THROUGH THE EVENING HOURS...WITH A FEW GUSTS TO AROUND 25
KTS...MAINLY FOR KPSF/KALB.
WINDS WILL DIMINISH THIS EVENING...WITH FEW-SCT STRATOCU CONTINUING.
THE INVERSION HEIGHT WILL SLOWLY LOWER BY WEDNESDAY MORNING...BUT
FLYING CONDITIONS WILL STILL REMAIN VFR.
WEST WINDS OF 5-10 KTS WILL CONTINUE OVERNIGHT. DURING DAYTIME
MIXING ON WEDNESDAY...WIND SPEEDS WILL INCREASE WITH WINDS OF 10-15
KTS AND A FEW HIGHER GUSTS. SCT CU/STRATOCU WILL CONTINUE TO BE
AROUND ON WEDNESDAY AT 3-4 KFT.
OUTLOOK...
WED PM-FRI AM...VFR. NO SIG WX.
FRI PM-SAT...MVFR/IFR. CHC -SN.
SUN...VFR. NO SIG WX.
&&
.HYDROLOGY...
PRECIPITATION THAT FALLS OVER THE NEXT FIVE DAYS IS EXPECTED TO
BE IN THE FORM OF SNOW AS AN ARCTIC AIR MASS SETTLES IN.
TEMPERATURES WILL AVERAGE WELL BELOW NORMAL DURING THE UPCOMING
WEEK. THE PERSISTENT COLD WILL CAUSE ICE TO FORM ON MOST BODIES
OF WATER. THERE IS THE POSSIBILITY FOR FREEZE UP ICE JAMS TO
OCCUR ON SMALL STREAMS IN NORTHERN AREAS. THIS COULD RESULT IN SOME
MINOR LOCALIZED FLOODING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.CLIMATE...
WE ARE AT THE CLIMATOLOGICAL COLDEST TIME OF THE YEAR FOR OUR AREA.
NORMAL TEMPERATURES FOR JANUARY 22ND THROUGH 24TH:
ALBANY: HIGHS AROUND 30. LOWS IN THE MID TEENS.
GLENS FALLS: HIGHS IN THE UPPER 20S. LOWS IN THE SINGLE DIGITS.
POUGHKEEPSIE: HIGHS IN THE MID 30S. LOWS IN THE MID TEENS.
BENNINGTON: HIGHS AROUND 30. LOWS NEAR 10.
PITTSFIELD: HIGHS IN THE UPPER 20S. LOWS NEAR 10.
RECORD LOWS FOR ALBANY (DAILY RECORDS DATE BACK TO 1874)
JANUARY 22ND... -20 DEGREES 1984
JANUARY 23RD... -20 DEGREES 1970
JANUARY 24TH... -17 DEGREES 1948
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO NOON EST
WEDNESDAY FOR NYZ038-041-043-047-058-063-082-083.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 6 PM EST
WEDNESDAY FOR NYZ032-033-042.
MA...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO NOON EST
WEDNESDAY FOR MAZ001-025.
VT...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO NOON EST
WEDNESDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...SND/NAS
NEAR TERM...SND/FRUGIS
SHORT TERM...NAS
LONG TERM...JPV
AVIATION...FRUGIS
HYDROLOGY...GJM/JPV
CLIMATE...ALY
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1144 AM CST TUE JAN 22 2013
.UPDATE...
ADDED 18Z TAF DISCUSSION.
MORNING UPDATE HAS LOWERED HIGHS SLIGHTLY AND LESSENED SNOW
WORDING. FORECAST SOUNDINGS VS CURRENT OBS SUGGEST HIGHS NEEDED TO
BE TRIMMED A BIT...MAINLY CENTRAL AND SW. CLOUDS SHOULD STAY IN
PLACE AND COLD AIR SEEMS TO STILL BE ENTRENCHED WITH 15Z OBJECTIVE
ANALYSIS STILL INDICATING WEAK PRESSURE RISES. WATER VAPOR IMAGERY
AND LATEST RAP OUTPUT ALSO SUGGEST WEAK SHORT WAVE/PV ANOMALY JUST
EXITING IA. VISIBLE IMAGERY ALSO SHOWS DEEPER TEXTURE ADVANCING
INTO MO WHICH IS SUPPORTED BY REGIONAL RADAR MOSAIC SO HAVE REDUCED
POPS AND ACCUMULATIONS. BETTER POTENTIAL MAY BE NORTH TONIGHT WHICH
WILL BE RE-EVALUATED WITH AFTERNOON PACKAGE.
REMNANTS OF WIND CHILL ADVISORY WILL BE ALLOWED TO EXPIRE AT 16Z.
&&
.SHORT TERM /TODAY/...
AREA OF SURFACE HIGH PRESSURE OVER THE AREA TO SLOWLY DRIFT EASTWARD
AND SOUTHWARD TODAY...WITH CONTINUED NORTHWEST FLOW ALOFT. WEAK
IMPULSES CONTINUE TO DROP SOUTHEASTWARD THROUGH THE STATE
TODAY...ALONG WITH ZONE OF WAA/MOISTURE ADVECTION IN THE LOW/MID
LEVELS MIGRATING OVER THE CWA THROUGH THE DAY SHOULD LEAD TO WEAK
LIFT IN THE LOW/MID LEVELS THROUGHOUT THE DAY. ALSO DECENT
ISENTROPIC LIFT SHOWING UP ACROSS EXTREME SOUTHWESTERN CWA THIS
MORNING...AND PUSHING EAST/NORTHEASTWARD THIS AFTERNOON. AMOUNT OF
MOISTURE BECOMES THE MAIN ISSUE...BUT SOUNDINGS SHOWING DECENT
SATURATION ACROSS MUCH OF THE EASTERN CWA AT VARIOUS TIMES
THROUGHOUT THE DAY. ALSO WITH COLD AIR IN PLACE BULK OF
LIFT/SATURATION IN THE DENDRITIC LAYER. THEREFORE EVEN THOUGH
MOISTURE IS LIMITED...SNOWFALL PRODUCTION WILL BE EFFICIENT THUS
HAVE GONE WITH HIGHER POPS ACROSS THE SOUTHWEST THIS MORNING AND
WEST/NORTHWEST THIS AFTERNOON. FEEL LIFT/MOISTURE AMOUNTS SHOULD BE
ABLE TO SQUEEZE OUT A FEW TENTHS TO HALF AN INCH OR SO THROUGHOUT
THE DAY. WAA WILL HELP TEMPS REBOUND SOME TODAY...BUT CLOUDS WILL
INHIBIT THE WARMING SOME. THEREFORE STILL KEPT TEMPS ON THE COLD
SIDE WITH HIGHS ONLY AROUND 10 ABOVE ACROSS THE NORTHEAST TO AROUND
20 SOUTH AND SOUTHWEST. BITTERLY COLD WIND CHILLS STILL EXPECTED
THIS MORNING...SO HAVE CONTINUED THE WIND CHILL ADVISORY ACROSS THE
NORTHEASTERN CWA THROUGH MID MORNING.
.LONG TERM /TONIGHT THROUGH MONDAY/...
WARM ADVECTION WILL INCREASE ACROSS THE STATE TONIGHT AS BAROCLINIC
ZONE MOVES EAST ACROSS THE STATE. ISENTROPIC LIFT IS EXPECTED TO
PERSIST THROUGH THE BOUNDARY WITH CLOUDS OVER MUCH OF CENTRAL IOWA
DURING THE NIGHT. THE EXCEPTION WOULD BE IN THE SOUTHWEST WHERE
LIFT SUBSIDES BY MIDNIGHT AS MAIN FORCING SHIFTS NORTHEAST. MODEL
SOUNDINGS AT MASON CITY AND WATERLOO SHOW LOWEST 250MB OF SOUNDINGS
CLOSE TO SATURATION IN THE DENDRITIC ZONE. ANTICIPATE SOME LIGHT
SNOW OVERNIGHT ACROSS FAR NORTH CENTRAL INTO NORTHEAST CORNER OF THE
FORECAST AREA AROUND WATERLOO. AMOUNTS WILL BE VERY LIGHT ALTHOUGH
HIGH SNOW RATIOS MAY LEAD TO AN HALF OF INCH OF SNOW IN SOME
LOCATIONS. THE STATE WILL SEE A BRIEF PERIOD OF WARMER TEMPERATURES
INTO WEDNESDAY...HOWEVER A FRONT MOVING THROUGH DURING THE DAY WILL
CURTAIL ANY WARMING ACROSS THE NORTH. READINGS FARTHER SOUTH WILL
HAVE MORE TIME TO RISE AND MAY CLIMB ABOVE FREEZING BY EARLY
AFTERNOON BEFORE COOLING ENSUES. GLANCING BLOW OF COOLER AIR INTO
THURSDAY AS SURFACE RIDGE SLIDES INTO THE GREAT LAKES WITH WARM
ADVECTION RE-INTENSIFYING BY THURSDAY AFTERNOON.
NEXT SYSTEM WILL PASS THROUGH NORTHERN ROCKIES AND APPROACH THURSDAY
NIGHT INTO FRIDAY. LIFT IS FORECAST TO INCREASE QUICKLY BY LATE
THURSDAY AS MOISTURE BEGINS TO RETURN. LIGHT SNOW IS EXPECTED TO
DEVELOP BY THURSDAY EVENING MAINLY ACROSS THE EASTERN HALF OF IOWA
AS MOISTURE EVENTUALLY RETURNS. SOME LIGHT ACCUMULATIONS WILL BE
POSSIBLE IN THE FAR EASTERN OF THE AREA BEFORE THE SYSTEM DEPARTS TO
THE EAST ON FRIDAY MORNING. THERE WILL BE A BRIEF BREAK FROM LATE
FRIDAY INTO SATURDAY EVENING AS HIGH PRESSURE PASSES THROUGH THE
STATE. THE NEXT IN A SERIES OF SYSTEM IS FORECAST TO ARRIVE ON
SUNDAY WITH THE THREAT OF RAIN OR SNOW AS THICKNESSES/TEMPERATURES
CONTINUE TO INCREASE.
&&
.AVIATION...22/18Z
PERSISTENT BAND OF VFR CIGS FROM THE DAKOTAS INTO IA WILL CONTINUE
TO DRIFT EASTWARD THROUGH THE PERIOD. LIGHT SNOW UPSTREAM IS
EXPECTED TO MATURE BY EARLY EVENING AND BRUSH NRN IA 00-06Z...LIKELY
AFFECTING KFOD/KMCW/KALO. CONDITIONS SHOULD DROP TO MVFR DURING THE
LIGHT SNOW...AND POTENTIALLY LOWER...BUT CONFIDENCE IN THAT
OCCURRENCE IS NOT GREAT ENOUGH TO INCLUDE AS OF YET. WINDS WILL
BECOME NWLY AND INCREASE VERY LATE IN THE PERIOD AS WELL.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE/AVIATION...SMALL
SHORT TERM...BEERENDS
LONG TERM...COGIL
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1239 PM EST TUE JAN 22 2013
.SYNOPSIS...
FRIGID ARCTIC HIGH PRESSURE WILL BUILD IN FROM THE WEST THROUGH MID
WEEK THEN CREST OVER THE REGION ON FRIDAY. LOW PRESSURE WILL PASS
WELL SOUTH OF THE AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1220 PM UPDATE...ADJUSTED THE SKY FORECAST TO ACCOUNT FOR MORE
CLOUDS ADVANCING INTO OUR SWRN AREAS AND THAT SHIELD PUSHING NE
ACROSS EAST-CENTRAL AREAS W/THAT LOW OFFSHORE. THE CANADIAN GEM
WAS DOING WELL W/THIS SETUP AS WELL AS THE RUC WHICH WERE USED TO
INITIALIZE AT 12 PM. MOST OF THE CLOUDS ACROSS THE NORTHERN 1/2 OF
THE CWA WILL BE HIGH CLOUDINESS AND THIN. POPS NEEDED A FURTHER
ADJUSTMENT S AND W BASED ON THE LATEST RADAR TRENDS AND OBS.
LATEST VISIBLE SATL IMAGERY SHOWED A NICE EYE ON THE LOW OFFSHORE
INDICATIVE OF THE INSTABILITY AROUND THE CENTER OF THE LOW.
PREVIOUS DISCUSSION...
THE LOW IS TRACKING JUST SOUTH OF THE GULF OF MAINE THIS MORNING
AND WILL RAPIDLY MOVE NE TODAY PASSING JUST EAST OF GRAND BANK
NEWFOUNDLAND THIS EVENING. A NORLUN TROUGH EXTENDS FROM THE LOW TO
THE NH SEACOAST/SOUTHWEST MAINE COAST. THE HEAVIER SNOW (3 TO 6
INCHES) IS EXPECTED TO REMAIN SOUTH OF OUR CWA. THE POPS/QPF/SNOW
AMOUNTS WERE INCREASED ACROSS THE SOUTHERN HALF OF HANCOCK COUNTY
WITH UP TO 2 INCHES OF SNOW EXPECTED OVERNIGHT INTO THIS MORNING.
ONCE THE LOW KICKS OUT THIS AFTERNOON THE FLOOD GATES OPEN FOR THE
COLDEST AIR MASS OF THE WINTER TO SPILL INTO THE AREA TONIGHT AND
WEDNESDAY. THE HEART OF THE COLDEST AIR MASS IS CURRENTLY BACK
ACROSS NORTHERN ONTARIO WHERE SATELLITE INDICATES THAT THERE ARE
LIKELY SFC TEMPS AS LOW AS -50F. THE UPPER LOW ASSOCIATED WITH
THIS COLD BALL WILL MOVE EAST WITH THE TROUGH AXIS EXTENDING DOWN
INTO NORTHERN NEW ENGLAND. BY 12Z WEDNESDAY 850 MB TEMPS OF -30C
ARE EXPECTED ACROSS THE CROWN OF MAINE AND NOT MUCH WARMER ALONG
THE COAST. THE CYCLONIC FLOW AROUND THE TROUGH WILL KEEP SOME
CLOUD COVER AROUND AND PERHAPS EVEN A FEW WIDELY SCATTERED SNOW
SHOWERS ACROSS NORTHERN AND WESTERN MAINE. AN INCREASING PRESSURE
GRADIENT WILL PREVENT THE LOWER LEVELS FROM DECOUPLING. THE BIG
CONCERN WILL BE FOR DANGEROUSLY COLD WIND CHILLS BEGINNING AROUND
MIDNIGHT TONIGHT AND CONTINUING INTO THE SHORT TERM. A WIND CHILL
WATCH WILL BE ISSUED FOR THE NORTHERN HALF OF THE CWA STARTING AT
06Z TONIGHT. ADVISORIES WILL LIKELY BE NEEDED TOWARD 12Z WEDNESDAY
FOR INTERIOR DOWNEAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
THE CORE OF SOME BITTERLY COLD ARCTIC AIR WILL BE PRESSING INTO THE
REGION ON WEDNESDAY. THE GRADIENT BETWEEN HIGH PRESSURE BUILDING IN
FROM THE WEST AND LOWER PRESSURE IN EASTERN CANADA WILL BRING GUSTY
WEST TO NORTHWEST WINDS WEDNESDAY INTO THURSDAY WITH THE FRIGID COLD
LASTING INTO THURSDAY. WIND CHILLS ARE EXPECTED TO BE AS LOW AS 35
TO 40 BELOW ACROSS CENTRAL AND NORTHERN AREAS WHERE A WIND CHILL
WATCH HAS BEEN ISSUED WEDNESDAY INTO THURSDAY. SOME MOISTURE BACKING
AROUND THE EASTERN CANADIAN TROUGH WILL WORK ITS WAY INTO THE AREA
LATE WEDNESDAY THROUGH WEDNESDAY NIGHT. THIS WILL BRING A THIN
OVERCAST AND SOME VERY FINE POWDERY PATCHY LIGHT SNOW SHOWERS
ESPECIALLY ACROSS THE FAR NORTH AND NORTHWEST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ARCTIC HIGH PRESSURE WILL BUILD OVER THE AREA ON FRIDAY BRINGING
SUNSHINE AND LIGHTER WINDS BUT STILL VERY COLD TEMPS. LOW PRESSURE
WILL TRACK OFF THE MID ATLANTIC COAST FRIDAY NIGHT. MODELS ARE IN
DISAGREEMENT ABOUT THE TRACK OF THIS LOW. THE GFS SLIDES THE
SYSTEM OUT TO SEA BRUSHING THE DOWNEAST COAST WITH SOME LIGHT
SNOW. THE NEW ECMWF ALLOWS A NEW TROUGH DIGGING INTO THE GREAT
LAKES REGION TO CAPTURE THE LOW AND CARRY IT NORTH BRINGING
SIGNIFICANT SNOW TO OUR REGION. THIS IS A BIG CHANGE FROM PREVIOUS
RUNS. FOR NOW WILL FORECAST A CHANCE OF SNOW FOR SATURDAY WITH
BEST CHANCES DOWNEAST. COLD DRY WEATHER WILL FOLLOW FOR LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR AT THE NORTHERN TERMINALS TODAY WITH A FEW BRIEF
PERIODS OF MVFR TONIGHT IN ISO -SHSN. A BRIEF PERIOD OF MVFR
POSSIBLE AT KBHB IN -SN THIS MORNING...BUT NOW LOOKING MORE LIKE
IT WILL REMAIN VFR AS THE STEADIER SNOW REMAINS SOUTH OF THE
TERMINAL.
SHORT TERM: GENERALLY VFR CONDITIONS ARE EXPECTED WEDNESDAY
THROUGH THURSDAY ALTHOUGH PATCHY LIGHT SNOW SHOWERS MAY BRIEFLY
LOWER CONDITIONS TO MVFR ACROSS THE NORTH. VFR CONDITIONS ARE
EXPECTED ON FRIDAY. VFR CONDITIONS ACROSS THE NORTH AND MVFR
CONDITIONS IN LIGHT SNOW DOWNEAST ARE EXPECTED ON SATURDAY.
&&
.MARINE...
NEAR TERM: THE GLW WILL BE ABLE TO TRANSITION TO A SCA BY 19Z AS
WIND GUSTS HAVE DROPPED BELOW 35 KTS. THE WINDS WILL GET CRANKING
LATER TONIGHT AS THE STRONGER COLD AIR ADVECTION REACHES THE
COAST.
SHORT TERM: AN SCA IS EXPECTED WEDNESDAY THROUGH THURSDAY
WITH SIGNIFICANT FREEZING SPRAY IN BITTER COLD CONDITIONS. WINDS
SHOULD BE LIGHTER ON FRIDAY AS HIGH PRESSURE BUILDS OVER.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL WARNING FROM 3 AM WEDNESDAY TO 1 PM EST THURSDAY
FOR MEZ001>006-010.
WIND CHILL ADVISORY FROM 3 AM TO 5 PM EST WEDNESDAY FOR MEZ011-
015>017-029>032.
MARINE...GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1228 PM EST TUE JAN 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 431 AM EST TUE JAN 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STEADY STATE HI
AMPLITUDE PATTERN WITH DEEP TROF OVER ERN NAMERICA DOWNSTREAM OF RDG
ALONG THE W COAST. CORE OF ARCTIC AIR AT 00Z WAS CENTERED IN NW
ONTARIO OVER YPL...WHICH REPORTED LOWEST H85 TEMP ON THE MAP WITH
-36C. INL/RB ALSO REPORTED NOTEWORTHY H85 TEMPS OF -30C/-31C AT 00Z.
FARTHER NW OF THIS CORE OF COLDEST AIR...00Z H85 TEMPS AT THE PAS
MANITOBA AND CHURCHILL MANITOBA WERE A MUCH MORE MODEST -23C. A FEW
PLACES OVER INTERIOR UPR MI HAVE SEEN SFC TEMPS FALL AS LO AS -15 TO
-20F...WITH LOWEST WIND CHILLS IN THE -30 TO -35F RANGE. WITH
LINGERING CYC NW FLOW OVER THE UPR LKS UNDER THIS BITTERLY COLD
AIR...LES CONTINUES MAINLY IN THE NW WIND SN BELTS. AS EXPECTED...
WITH VERY COLD AIR ELIMINATING THE DGZ...SNOWFLAKE SIZE HAS BEEN
VERY SMALL. THE SMALL FLAKES ARE VERY EFFECTIVE AT REDUCING VSBY...
SO WHERE LES IS OCCURRING...WHITE-OUTS ARE COMMON. FOR THE MOST
PART...SMALL FLAKES ARE LIMITING ACCUMS WITH MOST RECENT SPOTTER/
COOP REPORTS INDICATING MOSTLY 1-3IN/12HR SNOWFALL RATES. EXCEPTION
IS OVER THE FAR NE FCST AREA...WHERE MORE LONGER FETCH/MORE LK
MODERATION IS LIKELY ALLOWING THE DGZ INTO THE LOWEST LYRS AND
SHARPER LLVL CNVGC ENHANCED BY LAND BREEZES IS PROVIDING EXTRA LLVL
LIFT/FOCUS FOR SHSN. LOOKING JUST UPSTREAM TO THE NW...A WEAKER PRES
GRADIENT IS APPARENT UPSTREAM OF LK SUP.
TODAY...CWA WL REMAIN UNDER PERSISTENT NW FLOW ALF...BUT CORE OF
COLDEST AIR NOW IN PLACE IS PROGGED TO SHIFT TO THE E AS THE LLVL
FLOW BACKS...WITH H85 TEMPS FCST TO RISE TO WITHIN A FEW DEGREES OF
-25C BY 00Z THIS EVNG. COMBINATION OF CORE OF COLDEST AIR SHIFTING
TO THE E AND LIGHTER WINDS THAN YDAY WITH ARRIVAL OF WEAKER PRES
GRADIENT SHOULD ALLOW SOME MODERATION IN THE WIND CHILLS. SO GOING
ADVY EXPIRATION OF THOSE ADVYS AT 18Z LOOKS ON TRACK. HOWEVER...THE
AIRMASS WL REMAIN MORE THAN SUFFICIENTLY COLD FOR PERSISTENT LES/LK
CLDS DESPITE LARGER SCALE QVECTOR DVGC/SUBSIDENCE THAT IS FCST TO
LOWER INVRN BASE TOWARD 5K FT AND LIMIT DEPTH OF MSTR. BUT FCST
SDNGS STILL SHOW TEMPS WITHIN THE COLUMN WL REMAIN TOO LO FOR SN
FLAKE GROWTH...SO EXPECT FINER FLAKES TO REMAIN THE RULE. HEAVIER
LES WITH SOMEWHAT HIER TEMPS MODERATED BY LONGER FETCH OVER THE LK
AND LINGERING SHARPER LLVL CNVGC WL REMAIN THE RULE IN AREAS E OF
MUNISING. AS THE LARGER SCALE FLOW BACKS MORE WNW...EXPECT THE LES
OVER THE ERN CWA TO BECOME MORE CONFINED TO AREAS NEAR LK SUP E OF
MUNISING. OVER THE W...THE LES BANDS SHOULD SHIFT N OUT OF GOGEBIC
COUNTY BUT STILL IMPACT AREAS FM ONTONAGON THRU THE KEWEENAW.
TNGT...EXPECT A CONTINUED SLOW MODERATION AS LLVL WNW FLOW SHIFTS
COLDEST H85 AIR TO THE E. BY 12Z...H85 TEMPS ARE PROGGED TO BE ARND
-22C. LES SHOULD BE CONFINED TO MAINLY AREAS N OF ONTONAGON OVER THE
W AND TO NEAR LK SUP E OF PICTURED ROCKS OVER THE ERN CWA. WITH SOME
MODERATION IN THE CHILL...SN/WATER RATIOS WL LIKELY BECOME HIER WITH
EMERGENCE OF THE DGZ IN THE LOWEST FEW THOUSAND FEET OF THE
CONVECTIVE LYR. WITH THE MODERATING AIRMASS...MIN TEMPS WL NOT BE AS
LO AS THIS MRNG AT MOST SPOTS EXCEPT OVER THE INTERIO WCNTRL WHERE
LIGHTER WINDS AND AT LEAST SOME CLRG WL ALLOW MORE RADIATION
COOLING. SINCE WINDS OVER THE COLDER INTERIOR SHOULD GENERALLY BE
UNDER 10 MPH...SUSPECT WIND CHILLS FOR THE MOST PART WL REMAIN ABV
ADVY CRITERIA. OPTED TO EXTEND LES WRNG FOR ALGER/LUCE COUNTIES AND
WINTER WX ADVY FOR ONTONAGON COUNTY/THE KEWEENAW THRU TNGT TO
ACCOUNT FOR EXPECTED TRENDS NOTED ABV.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 431 AM EST TUE JAN 22 2013
MODELS ARE IN GOOD AGREEMENT THROUGH ALL BUT SUN/MON...SO FORECAST
CONFIDENCE IS HIGH THROUGH MOST OF THE LONG TERM.
WED AND WED NIGHT...AN UPPER TROUGH WILL PUSH THROUGH THE CWA
WED...HELPING FORM A MESO-LOW /AS INDICATED BY MAJORITY OF MODELS/
OVER FAR ERN LAKE SUPERIOR. WINDS WILL INITIALLY BE OUT OF THE WNW
WED MORNING...BUT WILL TURN NLY BY 00Z THU AFTER THE TROUGH
PASSES...THE MESO LOW DIMINISHES AND A SFC HIGH BEGINS PUSHING IN
FROM THE NW. 850MB TEMPS WILL START THE DAY AROUND -22C AND END THE
DAY AROUND -25C. EARLY IN THE DAY CONDITIONS WILL BE PRIME FOR
MODERATE TO LOCALLY HEAVY LES...BUT BY TIME WINDS TURN NLY...DRY AIR
AND LOWERING INVERSIONS WILL BEGIN TO LIMIT LES TO LIGHT TO MODERATE
INTENSITY. BY 12Z THU...WINDS WILL BE LIGHT AND QUITE ANTICYCLONIC
OVER LAKE SUPERIOR AS THE HIGH CENTER IS JUST NW OF THE LAKE. EXPECT
DIMINISHING LES THROUGH WED NIGHT. HIGHEST SNOWFALL AMOUNTS FOR WED
THROUGH WED NIGHT LOOK TO BE E OF MUNISING NEAR LAKE SUPERIOR WITH
OVER 6 INCHES AND FROM ONTONAGON TO TWIN LAKES WITH OVER 5 INCHES.
ELSEWHERE NEAR LAKE SUPERIOR...EXPECT 2-4 INCHES.
THU...THE SFC HIGH WILL SHIFT E OF THE CWA THROUGH THE
DAY...REACHING THE LOWER GREAT LAKES BY 00Z FRI. THIS PUTS THE
REGION UNDER S-SE LOW LEVEL FLOW BEHIND THE HIGH AND AHEAD OF A
TROUGH AND SFC LOW THAT WILL BE OVER THE DAKOTAS AT 00Z FRI.
THU NIGHT AND FRI...SLY FLOW CONTINUES AS THE TROUGH/SFC LOW MOVES
TO SE MN BY 12Z FRI...CAUSING 850MB TEMPS TO WARM TO THE MID TEENS
BELOW ZERO. SHOULD SEE LAKE EFFECT/ENHANCED SNOW OFF LAKE MI AHEAD
OF THE SYSTEM...HELPING TO BOOST SNOWFALL TOTALS IN SCHOOLCRAFT AND
LUCE COUNTIES DEPENDING ON EXACT WIND DIRECTION. THE INVERTED TROUGH
N OF THE SFC LOW WILL MOVE TO THE CENTRAL CWA AROUND 18Z FRI...THEN
TO THE ERN CWA BY 00Z SAT. MODELS SHOW AROUND 0.2 INCHES OF SYNOPTIC
QPF...AND NEARLY DOUBLE THAT DOWNWIND OF LAKE MICHIGAN. LOOKING AT
MODEL PROFILES...THE BEST LIFT WILL BE ABOVE THE FAIRLY SHALLOW
DGZ...SO SNOW TO LIQUID RATIOS WILL PROBABLY NOT BE THAT HIGH. AT
THIS POINT IT LOOKS LIKE MOST LOCATIONS WILL SEE AROUND 3 INCHES OF
SNOW WITH POSSIBLY 6 INCHES DOWNWIND OF LAKE MICHIGAN.
A SHORTWAVE TROUGH LOOKS TO MOVE THROUGH LATE FRI INTO EARLY SAT
NIGHT...WHICH SHOULD HELP GIVE A BRIEF BOOST TO LES IN THE NNW LOW
LEVEL WINDS AND 850MB TEMPS AROUND -17C. ANY GOOD LES SHOULD NOT
LAST LONG AS A SFC HIGH RIDGE MOVES TO WRN LAKE SUPERIOR AND 850MB
TEMPS INCREASE TO AROUND -13C BY 18Z. LOW LEVEL FLOW ONCE AGAIN
BECOMES SELY BEHIND THE RIDGE SAT NIGHT WITH 850MB TEMPS INCREASING
TO A BALMY -5 OR SO BY 12Z SUN. FOR SUN AND MON...MODELS DO NOT HAVE
GOOD AGREEMENT...BUT THEY SUGGEST THAT A SHORTWAVE MAY MOVE
SOMEWHERE NEAR OR OVER THE AREA SUN OR SUN NIGHT. JUST USED A
CONSENSUS OF MODELS FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1228 PM EST TUE JAN 22 2013
KIWD...AS THE LLVL FLOW BACKS MORE TO THE SW...EXPECT VFR CONDITIONS
TO CONTINUE UNTIL A SHORTWAVE PASSES WED MORNING AND BRINGS BACK IN
MVFR LAKE EFFECT SNOW SHOWERS.
KCMX...EXPECT PREDOMINANT IFR CONDITIONS THRU THE DAY WITH UPSLOPE
WNW FLOW OF ARCTIC AIR/LES. CONDITIONS SHOULD DETERIORATE TO LIFR
TNGT AS AXIS OF SHARP CNVGC GETS SITUATED OVER THE KEWEENAW AND
ENHANCES LES INTENSITY IN PERSISTENT UPSLOPE FLOW.
KSAW...EXPECT PREDOMINANT VFR CONDITIONS THRU THIS FCST PERIOD WITH
DOWNSLOPE WSW FLOW OF DRY AIR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 AM EST TUE JAN 22 2013
EXPECT NW WINDS UP TO 20 TO 25 KTS THRU TONIGHT TO DRIVE ARCTIC AIR
OVER THE UPPER GREAT LAKES. THERE WILL BE PERIODS OF HEAVY FREEZING
SPRAY IN AREAS WHERE THE WINDS ARE STRONGEST. THE NW WINDS WILL
STRENGTHEN TO 25 TO 30 KTS ON WED FOLLOWING THE PASSAGE OF A
DISTRUBANCE...CAUSING MORE HEAVY FREEZING SPRAY THRU WED NIGHT. A
WEAKER PRES GRADIENT/LIGHTER WINDS AND SOME MODERATION OF THE CHILL
WILL END THE HEAVY FREEZING SPRAY BY THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001>003-
084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ085.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MIZ009.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST WEDNESDAY FOR MIZ006-007.
WIND CHILL ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR
MIZ004-005-010>014.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY
FOR LSZ240>251-263>267.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
THURSDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
116 PM EST TUE JAN 22 2013
.SYNOPSIS...
COLDER AIR WILL ARRIVE ON GUSTY WEST TO NORTHWEST WINDS THIS
MORNING...WHICH WILL ALLOW LAKE EFFECT SNOWS TO DEVELOP NORTH OF
THE NEW YORK THRUWAY. OUTSIDE OF THE LAKE EFFECT SNOW...PARTLY TO
MOSTLY CLOUDY SKIES AND SCATTERED SNOW SHOWERS OR FLURRIES ARE
EXPECTED. THIS ACTIVITY WILL DIMINISH ON WEDNESDAY AS THE NEXT
CLIPPER MOVES IN. HIGH PRESSURE WILL THEN BUILD IN ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1020 AM UPDATE...
INTERESTING MESO WX DAY CONTINUES. SWD MVMNT OF LES SNOW BAND ACRS
ERN LAKE ONTARIO HAS SLOWED OVER THE PAST HR...WITH FETCH BEING
SOMEWHAT REDUCED. THIS HAS RESULTED IN THE WEAKENING OF THE BAND
ACRS NRN ONEIDA COUNTY. THERE ARE SOME HINTS IN RDR REFLEECTIVITY
THAT A MESO-VORTEX MAY BE DVLPNG ALONG THE BAND JUST W OF ROC. 00Z
MESO MDLS WERE HINTING AT THIS DVLPMNT. THIS REMAINS A LOW
CONFIDENCE FCST...BUT WE THINK THE BAND WILL REMAIN PRETTY MUCH
WHERE IT IS UNTIL DROPPING SWD LATER THIS AFTN (MAYBE WITH THE
PSSG OF THE MESO-VORT). NAM12 AND RUC STILL INDICATE A QUICKER SWD
MVMNT OF THE BAND (18-29Z INTO NRN CWA) ALBIET IN A WEAKER STATE.
GIVEN THE UNCERTAINTY...NO CHGS WILL BE MADE TO THE CRNT FCST. WE
WILL RE-EVALUATE ALL HEADLINES WITH THE AFTN PCKG. THANX BUF FOR
COLLAB. PREV BLO...
850 AM UPDATE...
LAKE BAND HAS BEGUN TO SHOW A SWD DRIFT ACRS SRN LAKE
ONTARIO...WITH LTL MVMNT NOTED THUS FAR ACRS THE ERN SXNS. SOME
INDICATIONS IN THE MESO-MDLS THAT WE`LL SEE ANOTHER MESO-VORTEX
MOVG EWD ALONG THE BNDRY THIS AFTN. SIG DIFFS IN THE SHORT TERM
GDNC W/ RESPECT TO THE SWD MVMNT OF THE BNDRY...WITH ARW
SUGGESTING THE SLOWEST MVMNT...WITH RUC SUGGESTING IT OVG INTO TEH
SYR AREA BY 18Z. WE WILL CONTINUE TO MONITOR BUT ARE THINKNG THAT THE
SWD DRIFT WILL BE A BIT LATER THAN CRNTLY FCST (LOW
CONFIDENCE)...SO WARNINGS HAVE BEEN DELAYED TIL 18Z FOR
ONON/MAD/SRN ONEIDA. IF ARW IS CORRECT...EVEN THIS TIMING WILL BE
TOO SLOW. NEEDLESS TO SAY...AN INTERESTING MESO MET DAY.
ELSEWHERE...SCT -SHSN OFF LAKE ERIE ACRS TNE SRN TIER INTO NE PA.
PREV BLO...
330 AM UPDATE...
COMPLICATED SFC PATTERN ACRS THE AREA TONIGHT. SFC LOW ACRS SRN
ONTARIO IS SLIDING EAST ALONG STATIONARY FRONT LURKING FM THE MAINE
COAST WWD INTO THE MOHAWK VLY. THIS FRNT SEPARATES WEST WINDS ACRS
FAR NRN ZONES FM EAST-NORTHEAST WINDS OVR THE DACKS AND SRN CANADA.
LK EFFECT BAND THAT TRAVERSED THRU SYRACUSE AND HAS LIFTED NORTH
INTO ONEIDA CNTY LKLY DUE TO UL WVS TRAVERSING ACRS THE AREA. MAIN
PART OF THE LAKE BAND TOOK ON NORTH TO SOUTH CONFIGURATION AS IT
DRIFTED THRU ONONDAGA CNTY AND IS NOW BECOMING MORE SINGULAR IN
ORIENTATION.
WEST-SOUTHWEST FLOW IS OCCURRING NOW WITH UPSTREAM CONNECTION TO LK
HURON. HIRES AND NAM12 INDICATES SFC LOW WL HEAD EAST BY 12Z DUE TO
PRESSURE FALLS AND AS IT PASSES INTO THE DACKS WINDS SHUD TURN MORE
NWRLY AS IT DOES SO. THIS WL LKLY START TO SHIFT THE LK BAND JUST A
TAD FURTHER SOUTH INTO NRN ONEIDA CNTY. HV GONE CATEGORICAL FOR
ONEIDA CNTY BTWN 12Z-18Z FOR SNOW SHOWERS WITH OCNLY HEAVY SNOW. LK
EFFECT SNOW SQUALLS CAN BE EXPECTED ACRS NRN ZONES NORTH OF THE NEW
YORK THRUWAY WITH TOTALS THRU 00Z WED APPCHG A FOOT ACRS NWRN ONEIDA
CNTY. LK EFFECT SNOW WARNING APPEARS REASONABLE FOR ALL OF ONEIDA
CNTY TDA. EXTREME INSTABILITY WL BE PRESENT WITH LK-INDUCED CAPES >
1000 J/KG WITH INVERSION DEPTHS OF ARND 10KFT. THIS MAY PRODUCE
SNOWFALL RATES OF ARND 2 INCHES PER HR AT TIMES TDA.
HIRES MODELS INDICATE BAND WL BEGIN TO SLIP SOUTH AFT 18Z THIS AFTN
INTO ONONDAGA/MADISON CNTYS THO HOW FAR SOUTH RMNS TO BE SEEN. 6-HR
AMNTS OF 2-5 INCHES IN THESE CNTYS WL BE POSSIBLE BY 00Z WED.
AFTN MAXES EXPECTED TO RISE INTO THE LWR TEENS TDA AS COLD AIRMASS
RMNS LOCKED IN ACRS CWA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
330 AM UPDATE...
SNOW BAND WILL DROP FURTHER SOUTH OVRNGT WITH HVY SNOW INTO
ONONDAGA/MADISON CNTYS AND HV UPGRADED THESE CNTYS TO WARNINGS.
OVRNGT MINS WL DIP IN THE SINGLE DIGITS AND WITH WINDS ARND 10 MPH,
WIND CHILL VALUES WILL DIP BLO -15F TONIGHT FOR NY COUNTIES EAST OF
I-81. THUS HV OPTED TO ISSUE A WIND CHILL ADVISORY FOR THESE LOCALES
FROM 05Z TONIGHT THRU 15Z WED.
ANOTHER CLIPPER ON TAP FOR WEDNESDAY WITH SNOW EXPECTED ONCE AGAIN
WITH AMNTS BTWN 0.5 AND 1 INCH. TEMPS WL ONCE AGAIN BE IN THE TEENS
ON WEDNESDAY AS NRLY FLOW PROVIDES A STEADY FLOW OF CLD AIR FM
CANADA.
HIPRES BUILDS IN BRIEFLY FOR THURSDAY SHUTTING OFF PCPN AND ALLOWING
TEMPS TO WARM SEVERAL DEGREES ABV VALUES EARLY IN THE WEEK. NEXT
SYSTEM WL MV IN FRI MRNG BUT IS SLOW TO ARRIVE WITH HIPRES HOLDING
TIGHT TO CWA THRU 12Z.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE MODELS CONTINUE TO SHOW FAIR AGREEMENT THROUGH THE
EXTENDED PERIOD. INITIALLY THE PERIOD BEGINS WITH SFC LOW PRES IN
THE MID ATLANTIC REGION LIFTING NORTHEAST ALONG THE NEW ENGLAND
COAST. THE ECMWF IS MUCH STRONGER AND FARTHER NORTH THAN THE GFS
WITH THIS FEATURE BUT SYSTEM REMAINS RATHER WEAK UNTIL ITS WELL
EAST OF AREA. WILL CONTINUE WITH HIGH CHC/LIKELY POPS FRIDAY NIGHT
WITH HIGHEST POPS NE PA AND SOUTHERN TIER.
SATURDAY THROUGH SUNDAY, AREA WILL BE UNDER A COLD AIRMASS WITH
NW FLOW. SCATTERED SNOW SHOWERS WILL PERSIST FOR MUCH OF CENTRAL
NEW YORK AS TEMPS RUN 5 TO 10 DEGREES BELOW NORMAL.
MONDAY THROUGH TUESDAY...UPPER LEVEL TROF WILL LIFT OUT OF THE
NORTHEAST AS A FLAT RIDGE BUILDS IN. TEMPS WILL MODERATE BACK
TO SEASONAL OR SLIGHTLY ABOVE SEASONAL NORMALS. THERE ALSO IS THE
CHC FOR LIGHT SNOW SHOWERS DUE TO THE WARM AIR ADVECTION.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LAKE EFFECT SNOW BAND SOUTHEAST OF LAKE ONTARIO WILL CONTINUE
SLOW PROGRESS SOUTHWARD THROUGH EARLY EVENING THEN GRADUALLY
WEAKEN OVERNIGHT. AT KRME, LAKE BAND IS CURRENTLY OVER TERMINAL
WITH LOW MVFR CONDITIONS EXPECTED THROUGH EARLY EVENING WITH
OCCASIONAL IFR THROUGH LATE AFTERNOON. OVERNIGHT, BAND WILL RESIDE
SOUTH OF AREA WITH PRIMARILY VFR CONDITIONS EXPECTED.
AT KSYR, LAKE BAND WILL DROP INTO THE AIRPORT BY 21Z. FROM LATE
THIS AFTERNOON THROUGH LATE TONIGHT IFR CONDITIONS WILL PERSISTS
WITH OCCASIONAL BELOW AIRPORT MINS FROM LATE THIS AFTERNOON
THROUGH EARLY EVENING. AFTER 09Z, BAND IS EXPECTED TO WEAKEN WITH
CONDITIONS IMPROVING TO MVFR.
AT KITH/KBGM/KELM, DIURNAL SNOW SHOWERS HAVE DEVELOPED DUE TO VERY
UNSTABLE LOW LEVELS. FOR THIS REASON INCLUDED OCCASIONAL IFR SNOW
SHOWERS THROUGH LATE AFTERNOON. REMAINDER OF PERIOD SHOULD BE
PRIMARILY VFR WITH STRATO CU AROUND 3500 FT. AFTER 18Z WED MORE
SNOW SHOWERS ARE LIKELY WITH POSSIBLE IFR.
AT KAVP, CONDITIONS WILL BE PRIMARILY VFR WITH CIGS AROUND 4K FT.
WEST WINDS 15 TO 20 KTS WITH GUSTS TO 25-30 KTS. THIS EVENING
WINDS WILL DECREASE TO 5-10 KNOTS AND CONTINUE THROUGH WEDNESDAY.
.OUTLOOK...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...PRIMARILY VFR.
FRI... IFR CONDITIONS POSSIBLE IN SNOW.
FRIDAY NIGHT/SATURDAY...MVFR SNOW SHOWERS RESTRICTIONS LIKELY FOR
CENTRAL NY.
SUNDAY...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
WEDNESDAY FOR NYZ009-036-037-045-046-057-062.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST WEDNESDAY FOR NYZ018-
036-037.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST WEDNESDAY FOR NYZ009.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...RRM
AVIATION...RRM
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
955 AM MST TUE JAN 22 2013
.AVIATION...18Z TAFS
AREAS OF MVFR CIGS TOWARDS CTRL SD WILL IMPROVE TO VFR THRU THIS
AFTERNOON. OTHERWISE...VFR CONDITIONS WILL PREVAIL THRU THE
FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 829 AM MST TUE JAN 22 2013/
UPDATE...15Z SURFACE ANALYSIS HAD WARM FRONT FROM EAST CENTRAL MT
TO THE NE PANHANDLE. 12Z KUNR SOUNDING SHOWED STRONG INVERSION
WITH WARM AIR NOT FAR FROM THE SURFACE OVER THE HIGHER ELEVATIONS.
AS UPPER RIDGE OVER THE WEST INCHES EAST TODAY...WARM FRONT SHOULD
MAKE SOME PROGRESS INTO THE FAR WESTERN SD PLAINS. SHARP
TEMPERATURE GRADIENT EXPECTED BY AFTERNOON. 12Z RAP AS WELL AS
BUFKIT MOMENTUM TRANSFER GUIDANCE SUGGESTS A FEW BREEZY/GUSTY
SPOTS OVER NORTHEAST WY/HIGHER ELEVATIONS OF THE BLACK HILLS FOR
THIS AFTERNOON...SO HAVE ADJUSTED ACCORDINGLY. REST OF FORECAST IN
GOOD SHAPE.
PREV DISCUSSION... /ISSUED 256 AM MST TUE JAN 22 2013/
DISCUSSION...STAUNCH WESTERN CONUS RIDGE CONTINUES TO SLOWLY PUSH
EAST...HOWEVER...THE ENTRENCHED ARCTIC AIR MASS IS REFUSING TO EXIT
EASY. ANOTHER STRONG COMPACT FAST MOVING MID LEVEL IMPULSE IS DIVING
SE ACROSS MB...AND WILL HELP REINFORCE THE CURRENT AIR MASS ACROSS
THE NORTHERN PLAINS. OTHERWISE...WAA IS ONGOING ACROSS THE
REGION...WITH VERY WARM TEMPS IN PLACE ACROSS NE WY AND THE BH PER A
DECENTLY MIXED BL. LIGHT SNOW/FLURRIES CONTINUE OVER THE EASTERN FA
PER THE WAA INDUCED UPGLIDE...WITH THIS AREA CONTINUING TO SHIFT
EAST. OTHERWISE....A RATHER STRONG NE PAC UPPER TROUGH IS ADVANCING
INTO THE WESTERN NOAM RIDGE AND WILL EVENTUALLY SPAWN A CLIPPER
SYSTEM INTO THE REGION...AFFECTING THE LOCAL AREA WED INTO THUR.
STRONG TEMP GRADIENT WILL CONTINUE ACROSS THE FA TODAY...WITH HIGHS
NEAR 50 IN NE WY TO THE LOWER 20S OVER THE EAST. SFC WARM FRONT WILL
STRUGGLE EAST OFF THE HIGHER TERRAIN GIVEN A RATHER STRONG WAA
INVERSION IN PLACE AND RELATIVELY POOR LL FLOW TO SUPPORT MIXING.
CONTINUED LIGHT SNOW SHOWER CHANCES THIS MORNING ACROSS THE FAR
EAST...WITH DRY CONDITIONS THIS AFTERNOON ALL PLACES. AMPLE
SUNSHINE EXPECTED WESTERN AREAS...WITH FGEN CLOUDS LINGERING OVER
THE EAST THROUGH MUCH OF THE DAY. LL FLOW WILL BEGIN TO RESPOND TO
THE ADVECTING NW CONUS UPPER IMPULSE WED...WITH SFC PRESSURE FALLS
UPTICKING OVER NE WY. MEANWHILE...TODAY/S MB TROUGH WILL SUPPORT A
COLD PUSH ACROSS THE EASTERN NORTHERN PLAINS TONIGHT...WHICH WILL
SETTLE WEST INTO THE FA GIVEN SFC PRESSURE FALLS IN THE LEE OF THE
ROCKIES SUPPORTING EASTERLY FLOW. FORECAST MODELS HAVE TRENDED
MUCH COLDER PER TEMPS OVER THE EASTERN 2/3 OF THE FA WED...AND
HAVE CUT HIGHS SIG FOR THIS. UPSLOPE COMPONENT TO THE FLOW
CERTAINLY WILL NOT HELP THINGS EITHER. LL EASTERLY UPSLOPE
/SUFFICIENTLY MOIST/ FLOW MAY SUPPORT LOW CLOUDS OVER THE SD
PLAINS BY WED AFTERNOON/EVENING...WITH FOG POSSIBLE OVER THE
EASTERN BH FOOTHILLS BY EVENING. HAVE INTRODUCED A PATCHY FOG
MENTION FOR THIS. MEANWHILE NE WY AND THE BH WILL REMAIN QUITE
WARM...AS THE LL COLD AIR MASS WILL REMAIN SHALLOW AND CONFINED TO
LOWER TERRAIN. KEPT WARM TEMPS IN THIS REGION THROUGH WED. CLIPPER
SYSTEM WILL SHIFT WINDS WESTERLY OVER THE ENTIRE FA THUR...WITH BL
WARM DOWNSLOPE FLOW EXPECTED TO MIX DOWN AT MOST PLACES...ESP THE
SW 3/4. HAVE CUT BACK ON POPS WITH THIS SYSTEM GIVEN LACK OF
APPRECIABLE MOISTURE WITH BEST LL AND MID LEVEL FORCING EXPECTED
TO REMAIN NORTH OF THE FA. REMOVED POPS WED NIGHT AND RETAINED A
LOW CHANCE MENTION ACROSS THE NORTH THUR. PERHAPS THE MAIN IMPACT
FROM THIS SYSTEM WILL BE WINDS ON THE BACKSIDE OF THIS SYSTEM THUR
AFTERNOON AND EVENING. DECENT PRESSURE RISE/CAA COMBO SHOULD
SUPPORT ADV TO NEAR ADV CRITERIA FOR MUCH OF NW SD. COLD AIR WILL
FILTER BACK INTO MUCH OF THE AREA THUR NIGHT...WITH WINDS SLOWLY
SUBSIDING.
EXTENDED...RIDGE OVER THE WRN CONUS WILL SLOWLY SHIFT EAST ACROSS
THE NORTHERN PLAINS THROUGH THE WEEKEND...BRINGING MILD AND DRY
CONDITIONS. MODELS START TO DIVERGE ON A SOLUTION TO START NEXT WEEK
THOUGH OVERALL PATTERN REMAINS UNSETTLED...SO WILL LEAVE LOW POPS IN
FOR NOW.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...WFO UNR
LONG TERM....WFO UNR
AVIATION...77