Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/31/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
918 AM MST SUN JAN 29 2012
.UPDATE...
&&
.AVIATION...VFR THRU TONIGHT WITH ONLY SOME MID AND HIGH LEVEL
CLOUDINESS. LATEST RUC AND HRRR DISAGREE SOMEWHAT ON WIND
DIRECTIONS BY MID TO LATE AFTN. THE RUC SHOWS SSW WINDS BECOMING
WNW BY 18Z AND THEN KEEPS THE SAME DIRECTION THRU THE AFTN WHILE
THE HRRR SHOWS A WEAK LONGMONT ANTICYCLONE DEVELOPING WITH WNW
WINDS BECOMING LIGHT ELY BY 22Z. FOR NOW WILL KEEP A WNW DIRECTION
LIKE THE RUC SHOWS FOR THE AFTN HOURS.
&&
.PREV DISCUSSION... /ISSUED 335 AM MST SUN JAN 29 2012/
SHORT TERM...WILL SEE A WARMER BUT LESS BREEZY DAY TODAY AS AN
UPPER RIDGE OVER THE SOUTHWEST MOVES SLIGHTLY EAST TO ADVECT IN
WARMER TEMPERATURES. THIS WILL PRODUCE TEMPERATURES ABOUT 10 TO
15 DEGREES WARMER THAN YESTERDAY. HIGH LEVEL MOISTURE IN THE FORM
OF CIRRUS CLOUDS ARE MOVING OVER THE STATE FROM THE PACIFIC
NORTHWEST. EXPECT PERIODS OF HIGH CLOUDS THROUGH THE DAY INCLUDING
A DEVELOPING WAVE CLOUD THIS AFTERNOON. A SLIGHT INCREASE IN
MOISTURE WILL KEEP HUMIDITIES SLIGHTLY HIGHER THAN YESTERDAY AND
WINDS ARE EXPECTED TO BE SLIGHTLY LESS THAN YESTERDAY FOR THE
PLAINS. THEREFORE NO FIRE WEATHER HIGHLIGHTS ARE NEEDED FOR TODAY.
A STABLE LAYER AT MOUNTAIN TOP AND TIGHT PRESSURE GRADIENT IS
PRODUCING STRONG AND GUSTY WINDS OVER THE HIGHER TERRAIN DOWN
INTO THE FOOTHILLS THIS MORNING. THIS WIND IS EXPECTED TO
DECREASE THROUGH THE DAY BUT SHOULD STILL SEE GUSTS IN THE 25 TO
40 MPH RANGE AS A LEESIDE SURFACE TROUGH REMAINS.
LIGHTER BUT STILL BREEZY WEST WINDS TONIGHT ALONG WITH WARMER AIR
ADVECTED ALOFT WILL MODERATE MINIMUM TEMPERATURES WITH READINGS IN
THE MID 20S TO MID 30S FOR THE PLAINS AND IN THE TEENS TO NEAR 20
FOR THE MOUNTAINS.
LONG TERM...ANOTHER MILD DAY CAN BE EXPECTED MONDAY WITH WARM MID
LEVEL TEMPS AND BREEZY DOWNSLOPE FLOW. LEE SURFACE TROUGH AND A
MILD START TO THE DAY WILL HELP OFFSET THE INCREASE IN CLOUD
COVER...SO HIGH TEMPS AT OR SLIGHTLY ABOVE 60F ARE FORECAST FOR
THE PLAINS. IN THE HIGH COUNTRY...LOOK FOR A MILD DAY AS WELL
BEFORE WEAK COLD ADVECTION AND INCREASING MOISTURE BRING A CHANCE
OF LIGHT SNOW BY MONDAY NIGHT. THE CURRENT SATELLITE IMAGES ARE
FAIRLY IMPRESSIVE WITH THIS NEXT SHORT WAVE...BUT MODELS DO NOT
INDICATE MUCH MOISTURE REACHING COLORADO. THERE IS SOME WEAK Q-G
VERTICAL MOTION...SO THINK THE MODELS MAY BE A BIT TOO DRY
ESPECIALLY CONSIDERING THE CURRENT SATELLITE PICS. HOWEVER...ANY
SNOW THAT DOES FALL SHOULD BE LIGHT WITH ALMOST DUE WESTERLY
OROGRAPHIC FLOW.
ON TUESDAY...WE EXPECT SOME DRYING IN THE HIGH COUNTRY IN BETWEEN
WEATHER SYSTEMS. BY TUESDAY NIGHT AND WEDNESDAY...MODELS SOLUTIONS
DIFFER SIGNIFICANTLY WITH TIMING AND INTENSITY OF SHORT WAVES AND
CONSIDERABLE RUN TO RUN DISCREPANCIES EXIST. AS A RESULT...FORECAST
CONFIDENCE IN TIMING THESE IS LACKING SO A PROLONGED PERIOD OF
CONSERVATIVE POPS FOR THE HIGH COUNTRY IS REASONABLE. THE BEST
CHANCE SEEMS TO BE CENTERING ON WEDNESDAY NIGHT INTO THURSDAY WITH
POTENTIAL FOR A STRONGER SHORT WAVE DROPPING ACROSS THE FORECAST
AREA IN DEVELOPING NORTHWEST FLOW ALOFT. TEMPERATURES WILL STILL
AVERAGE A FEW DEGREES ABOVE NORMAL TUESDAY AND WEDNESDAY...WITH
COOLER READINGS EXPECTED BY THURSDAY WITH STRONGER COLD ADVECTION
NOTED IN MOST MEDIUM RANGE MODEL SOLUTIONS. LATEST TRENDS ARE
POINTING TOWARD A DEEPER TROUGH...WHICH MAY BE ENOUGH TO BRING A
CHANCE OF SNOW TO THE PLAINS.
AFTER THAT TROUGH...A LARGE AND WARM RIDGE IS EXPECTED TO BUILD
OVER THE CENTRAL ROCKIES. THE WARMUP MAY TAKE A COUPLE DAYS WITH
COLD AIR EAST OF THE ROCKIES GRADUALLY ABATING...BUT ABOVE NORMAL
TEMPS WILL LIKELY RETURN BY NEXT WEEKEND.
AVIATION...
VFR CONDITIONS EXPECTED THROUGH MONDAY WITH ONLY HIGH LEVEL
CLOUDS. GUSTY WEST WINDS ARE EXPECTED TO CONTINUE OVER KBJC AND
AT TIMES KDEN AS THE MOUNTAIN WAVE PATTERN AND TIGHT SURFACE
PRESSURE GRADIENT REMAINS THIS MORNING. SHOULD SEE THESE WINDS
RELAX THROUGH THE DAY AS THE GRADIENT DECREASES. WESTERLY
COMPONENT TO WINDS WILL DOMINATE THROUGH MONDAY AS A LEE SURFACE
TROUGH REMAINS OVER THE EASTERN PLAINS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KRIEDERMAN
LONG TERM....BARJENBRUCH
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
509 PM EST SUN JAN 29 2012
.SYNOPSIS...
A COLD FRONT PASSES THROUGH LATE TONIGHT. HIGH PRESSURE RETURNS ON
MONDAY. A WARM FRONT APPROACHES MONDAY NIGHT AND LIFTS NORTH OF
THE AREA TUESDAY MORNING. A COLD FRONT APPROACHES THE AREA
WEDNESDAY AND THEN MOVES THROUGH WEDNESDAY NIGHT. HIGH PRESSURE
BUILDS IN BRIEFLY ON THURSDAY. UNSETTLED FOR THURSDAY NIGHT
THROUGH SUNDAY WITH POTENTIAL IMPACTS FROM SEVERAL STORM SYSTEMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
INCREASING PRESSURE GRADIENT BETWEEN HIGH OFFSHORE AND LOW
APPROACHING FROM GREAT LAKES. POTENT SHORTWAVE ALOFT WITH 500 MB
VORT MAX AXIS MOVING THROUGH THE REGION LATE THIS EVENING AND THEN
EXITING TO THE EAST LATER OVERNIGHT. CLOUDS THICKEN AND LOWER THIS
EVENING AHEAD OF A COLD FRONT AT THE SURFACE. THE FRONT IS
FORECAST TO MOVE THROUGH SHORTLY AFTER MIDNIGHT. LOW LEVEL JET
INCREASES QUITE A BIT WITH 925 MB WINDS OF 40 TO 45 KT MOVING
ACROSS JUST AHEAD OF THE FRONT WITH BEST MIXING OVER THE WATER.
MAX WINDS LOOK TO BE GENERALLY 4Z TO 8Z...WITH WIND GUSTS MOSTLY
NEAR 30 MPH OVER LAND.
CONCERNING POPS...THE FORCING FROM THE SHORTWAVE ALONE KEEPS THE
FORECAST AT CHANCE...BUT NOT ANY HIGHER CONSIDERING THE DRY LOW
LEVELS AND MODEL SOLUTIONS. THE LARGE LIFTED INDEX TENDENCY AND
STEEPER LAPSE RATES IN THE LOWER LEVELS GO INTO THE FORCING
FACTORS. PRECIP TYPE WILL BE MAINLY SNOW SHOWERS NORTH AND WEST
OF NEW YORK CITY AND RAIN SHOWERS MIXING WITH SNOW SHOWERS FOR THE
REMAINDER OF THE AREA. THERE IS A CHANCE SNOW SHOWERS COULD BE
LOCALLY MODERATE TO HEAVY IN THE FORM OF SNOW SQUALLS BUT WILL BE
QUITE BRIEF IN DURATION. THIS IS MAINLY ACROSS THE COLDER
LOCATIONS IN LOWER HUDSON VALLEY...INTERIOR NORTHEAST NEW JERSEY
AND INTERIOR SOUTHWEST CONNECTICUT. JUST HAVE A FEW TENTHS OF AN
INCH OF SNOW IN NORTHERN ORANGE WHERE CONFIDENCE IS A BIT HIGHER
WITH SNOWFALL BUT IN THOSE OTHER LOCATIONS MENTIONED
PREVIOUSLY...COULD ALSO HAVE A QUICK COATING OF SNOW. MESOSCALE
MODELS OF NSSL WRF AND HRRR DEPICT A DETERIORATING LINE OF
REFLECTIVITY REPRESENTING THE SHOWERS APPROACHING LATER THIS
EVENING AND MOVING THROUGH BETWEEN 4 AND 8Z. AGAIN...THIS IS A
QUICK DURATION AND THINKING THAT IF TURNS OUT THIS LINE OF SHOWERS
IS LONGER LIVED AND STRONGER MORE PLACES COULD GET A QUICK COATING
OF SNOW...MAINLY ON THE GRASSY SURFACES WITH SOME QUICK 1 INCH
SNOW AMOUNTS MAINLY ON HIGHER ELEVATIONS. HOWEVER...CONFIDENCE IS
NOT THAT HIGH WITH MODEL POPS BEING SO LOW.
MODEL QPF FIELDS ARE VERY LOW THOUGH ON THE ORDER OF JUST A FEW
HUNDREDTHS OF AN INCH AND AGAIN DRY LOW LEVELS WILL ACT TO
DIMINISH THE PRECIP COMING IN FROM THE WEST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
WINDS WILL BE DECREASING AS THE LOW PUSHES TO THE EAST OFFSHORE AND
SOUTH OF NOVA SCOTIA ON MONDAY. DRIER AIR MOVES INTO PLACE AS HIGH
PRESSURE FROM THE SOUTH WILL BE BUILDING IN WITH SOME RIDGING.
HOWEVER...COLDER 850 TEMPS DOWN TO -9 TO -13 C LEAD TO A GREATER
WEIGHT OF THE COLDER MET GUIDANCE FOR HIGH TEMPS. IN
ADDITION...LESS VERTICAL MIXING IS EXPECTED THAN TODAY WITH MIXING
UP TO A LITTLE ABOVE 850 HPA. FLOW ALOFT BECOMES QUASI-ZONAL.
MONDAY NIGHT...AN APPROACHING WARM FRONT FROM THE WEST WILL MOVE
INTO THE AREA. MOST PRECIP WILL BE IN THE FORM OF SNOW SHOWERS
MOSTLY IN THE NORTHERN ZONES. QPF AGAIN IS ONLY ON THE ORDER OF A
FEW HUNDREDTHS OF AN INCH AND FORCING IS EVEN WEAKER THAN FORCING
TONIGHT. THEREFORE...JUST LEFT SLIGHT CHANCE POPS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
WARM FRONT LIFTS NORTH OF THE AREA EARLY TUESDAY WITH UNSEASONABLY
MILD TEMPS EXPECTED FOR TUESDAY AND WEDNESDAY. CHANCE OF SHOWERS
BEGINNING LATE TUESDAY NIGHT AS A COLD FRONT APPROACHES...WITH THE
BEST CHANCE FOR RAIN ARRIVING WEDNESDAY AFTERNOON AHEAD OF THE
FRONT. COLD FRONT PASSAGE EXPECTED OVERNIGHT WEDNESDAY...WITH COOLER
BUT STILL ABOVE AVERAGE TEMPS ON THURSDAY.
AFTER THURSDAY...THE PICTURE BECOMES MUCH LESS CERTAIN WITH WIDE
DIVERGENCE IN MODEL SOLUTIONS CONTINUING. ECMWF HAS COME IN EVEN
QUICKER WITH ITS HANDLING OF A SURFACE LOW MOVING OUT OF THE OHIO
VALLEY...LATEST RUN MOVES THE LOW JUST SOUTH OF THE AREA THURSDAY
NIGHT AND DEEPENS IT EAST OF THE AREA ON FRIDAY. THIS SYSTEM IS
FOLLOWED BY A COLDER SYSTEM WITH SECONDARY COASTAL LOW DEVELOPMENT
STARTING LATE SUNDAY. THE CURRENT CANADIAN RUN MOVES A PRECIP SHIELD
INTO THE AREA ON SATURDAY AHEAD OF A SOUTHERN STREAM LOW OVER THE
MISSISSIPPI VALLEY AND DEVELOPING SECONDARY LOW. THE OPERATIONAL GFS
IS DRY OVER THE SAME PERIOD WITH SURFACE LOWS PASSING TO THE SOUTH
AND EAST OF THE AREA ON FRIDAY AND SUNDAY. KEPT HIGHEST POPS IN FOR
SATURDAY CLOSER TO PREVIOUS ECWMF RUNS AND AS A NOD TO THE CANADIAN
SOLUTION. THIS IS EMPHATICALLY A LOW CONFIDENCE FORECAST FOR THE
THURSDAY NIGHT THROUGH SUNDAY PERIOD.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
RIDGE OF HIGH PRESSURE TO THE EAST WEAKENS AS A COLD FRONT
APPROACHES THROUGH EARLY THIS EVENING. THE FRONT CROSSES THE
TERMINALS FROM ABOUT 05Z THROUGH 10Z. HIGH PRESSURE BUILDS BEHIND
THE FRONT MONDAY.
VFR THROUGH THE TAF PERIOD. MAINLY DRY...HOWEVER THERE IS A CHANCE
OF SCATTERED SNOW SHOWERS WITH THE FRONT. BEST CHANCE WILL BE AT
KSWF WHERE LOW END VFR TO HIGH END MVFR CONDITIONS WILL BE POSSIBLE
FROM 05Z TO 08Z.
GUSTY SOUTHWESTERLY WINDS SHIFT BACK TO WEST WITH THE PASSAGE OF THE
FRONT...AND GUSTS INCREASE FOR A TIME...NEARING 30 KTS. SOME
UNCERTAINTY WITH THE TIMING OF THE WIND SHIFT AND MAY BE AN HOUR OR
SO EITHER SIDE OF THE FORECAST TIME.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
MONDAY THROUGH TUESDAY...VFR. GUSTY WESTERLY WINDS MONDAY.
WEDNESDAY...SUB-VFR POSSIBLE IN RAIN.
THURSDAY...VFR.
FRIDAY...LOW CHANCE OF SUB VFR.
&&
.MARINE...
GALES EXPECTED TO DEVELOP BETWEEN 0Z AND 6Z MON ACROSS THE WATERS
AND THEN DIMINISH TOWARDS MONDAY MORNING AS LOW PRESSURE
APPROACHES FROM THE WEST. HIGHEST WINDS AND SEAS EXPECTED NEAR
AND SHORTLY AFTER MIDNIGHT WITH BEST LOW TO MID LEVEL FORCING NEAR
THAT TIME. SCA THEREAFTER LATER ON MONDAY AS LOW PULLS AWAY
OFFSHORE.
SCA LEVEL SEAS FOR THE ATLANTIC ZONES EXPECTED ON TUESDAY WITH
STRONG SOUTHERLY FLOW FOLLOWING WARM FRONTAL PASSAGE. SEAS MAY
BRIEFLY SUBSIDE BELOW SCA CRITERIA TUESDAY NIGHT INTO WEDNESDAY
BEFORE BUILDING BACK LATE WEDNESDAY AHEAD OF A COLD FRONT. ROUGH
SEAS CONTINUING WEDNESDAY NIGHT INTO THURSDAY MORNING FOLLOWING COLD
FRONT PASSAGE...BEFORE DIMINISHING LATE THURSDAY AND FRIDAY.
&&
.HYDROLOGY...
ANY LIQUID EQUIVALENT PRECIPITATION THROUGH WEDNESDAY IS EXPECTED
TO BE GENERALLY LESS THAN A TENTH OF AN INCH ON AVERAGE.
&&
.EQUIPMENT...
THE WEATHER OBSERVATION FROM CENTRAL PARK WILL BE UNAVAILABLE
UNTIL FURTHER NOTICE. THIS IS DUE TO A SIGNIFICANT POWER
INTERRUPTION TO THE CENTRAL PARK AUTOMATED SURFACE OBSERVING
STATION /ASOS/ AND BACKUP STATION. UTILITY WORKERS ARE ADDRESSING
THE PROBLEM...BUT THERE IS CURRENTLY NO ESTIMATED TIME FOR RETURN
TO SERVICE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST MONDAY FOR ANZ330-335-338-340-345-
350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-
340-350-353.
&&
$$
SYNOPSIS...JM/MAS
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MAS
AVIATION...MET
MARINE...JM/MAS
HYDROLOGY...JM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
419 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING CLIPPER TYPE SYSTEM WILL BRING SOME SNOW TO A GOOD
PORTION OF OUR REGION TONIGHT WITH SOME GUSTY WINDS AND SNOW
SQUALLS ALSO POSSIBLE. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD
INTO THE REGION ON MONDAY. THIS WILL BE FOLLOWED BY A WARM FRONT
WHICH WILL APPROACH OUR REGION FROM THE SOUTHWEST MONDAY NIGHT...
BRINGING ANOTHER ROUND OF SNOW TO OUR REGION MONDAY NIGHT INTO
TUESDAY MORNING.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 4 PM EST...FIRST BATCH OF SNOW MOVING THROUGH THE
ADIRONDACKS WITH THE FIRST BOUNDARY WITH THE MAIN EVENT YET TO
FOLLOW AS THE LEADING EDGE OF SNOW AHEAD OF THE CLIPPER SYSTEM
MOVING INTO WESTERN NEW YORK. THE WINTER WEATHER ADVISORY
CONTINUES FOR THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY
UNTIL 10 AM MONDAY MORNING. EXPECT SNOWFALL AMOUNTS RANGING FROM 3
TO 8 INCHES IN THE ADVISORY AREA ALONG WITH BLOWING SNOW AS WEST
TO NORTHWEST WINDS OF 10 TO 20 MPH WITH GUSTS UP TO 25 MPH WILL BE
COMMON WITH HIGHER GUSTS POSSIBLE WITH SOME SNOW SQUALLS LATER
THIS EVENING. THIS CLIPPER TYPE SYSTEM HAS SOME FAIRLY GOOD
DYNAMICS WITH IT INCLUDING A STRONG VORT AXIS AND LATEST IR SAT
PICS ARE INDICATING COOLING CLOUD TOPS. THERE ALSO COULD BE SOME
EMBEDDED SNOW SQUALLS THIS EVENING AND EVEN AN ISOLATED CHC OF
SOME THUNDER SNOW ESPECIALLY CLOSER TO LAKE ONTARIO AS THE
SHOWALTER INDICES BRIEFLY GET BELOW ZERO. BOTH THE HIRESWRF MODEL
COMPOSITE REFLECTIVITY AND THE HRRR COL MAX REFLECTIVITY HAVE
REFLECTIVITY VALUES INDICATIVE OF SNOW SQUALLS DURING THE LATE
EVENING TO AROUND MIDNIGHT TIME FRAME. IF THESE SNOW SQUALLS
BECOME MORE CERTAIN SPS WILL LIKELY BE ISSUED. LOWS TONIGHT ARE
EXPECTED TO RANGE FROM THE MID TO UPPER TEENS NORTHWEST TO UPPER
20S SOUTHEAST.
LATE TONIGHT AND MONDAY...IN THE WAKE OF THE CLIPPER TYPE SYSTEM
A LAKE EFFECT BAND WILL SET UP WHICH WILL INITIALLY BE ORIENTED
TOWARD THE WESTERN ADIRONDACKS AND THEN SLIDE SOUTHEASTWARD INTO
THE MOHAWK VALLEY. AS THIS BAND WILL BE SHORT LIVED WITH A RIDGE
OF HIGH PRESSURE BUILDING QUICKLY INTO THE REGION BY
LATE MORNING...EXPECT THE GREATEST ACCUMULATIONS WILL BE ACROSS
SOUTHERN PORTIONS WESTERN ADIRONDACKS AND THE WESTERN MOHAWK
VALLEY. THIS ADDITIONAL SNOW IN THE WESTERN MOHAWK VALLEY SHOULD
BE ENOUGH TO RESULT IN THE AREA AVERAGING OVER 4 INCHES OF SNOW
WHEN COUPLED WITH THE SNOW FROM THE CLIPPER TYPE SYSTEM. BY MONDAY
AFTERNOON THE RIDGE OF HIGH PRESSURE IS ALREADY CRESTING ACROSS
THE FA AND THEN SLIDING EAST OF THE FA BY EVENING. EXPECT HIGHS ON
MONDAY TO RANGE FROM THE LOW TO MID 20S NORTHWEST TO MID TO UPPER
30S SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
MONDAY NIGHT INTO TUESDAY MORNING THE FA IS EXPECTED TO BE
IMPACTED BY A WARM FRONT LIFTING NE FROM THE OHIO VALLEY. LIGHT
SNOW IS EXPECTED TO OVERSPREAD MUCH OF THE FA FROM SOUTHWEST TO
NORTHEAST MONDAY EVENING WITH THE HIGHEST QPF FROM THE MOHAWK
VALLEY NORTH IN NEW YORK AND ACROSS SOUTHERN VERMONT. THIS EVENT
GENERALLY LOOKS LIKE 2 TO 4 INCHES TOTAL ACROSS NORTHWEST PORTIONS
OF THE FA WITH MOST OTHER AREAS HAVING AROUND AN INCH OF
SNOW...ALTHOUGH THE MOUNTAINS EITHER SIDE OF THE GREATER CAPITAL
DISTRICT MAY PICK UP A COUPLE OF INCHES. EXPECT LOWS MONDAY NIGHT
TO BE IN THE MID TEENS TO MID 20S.
TUESDAY AFTERNOON INTO TUESDAY NIGHT EXPECT THE WARM FRONT TO BE
NORTH OF THE BULK OF THE FA BY TUESDAY EVENING WITH THE FA LEFT IN
THE WARM SECTOR. THERE WILL STILL BE A CHANCE OF PCPN TUESDAY
AFTERNOON INTO TUESDAY NIGHT MAINLY ACROSS THE NORTHERN HALF OF
THE FA UNTIL THE COLD FRONT ARRIVES ON WEDNESDAY. EXPECT HIGHS ON
TUESDAY TO RANGE FROM THE MID 30S NORTHWEST TO UPPER 40S TO AROUND
50 SOUTHEAST WITH LOWS TUESDAY NIGHT RANGING FROM THE UPPER 20S TO
LOWER 30S NORTH TO MID 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST STARTS OUT VERY MILD MID WEEK...AND THEN
BECOMES VERY UNSETTLED WITH CONTINUED MEDIUM RANGE DETERMINISTIC AND
ENSEMBLE MODEL UNCERTAINTY...WITH A LOW CONFIDENCE FORECAST FROM
THURSDAY INTO WEEKEND. WE WENT CLOSE TO THE HPC GUIDANCE...HOWEVER
THE LATEST 12Z ECMWF WOULD INDICATE THAT TWO SEPARATE SYSTEMS IN THE
W/SW FLOW COULD IMPACT THE NORTHEAST THU NIGHT THROUGH FRIDAY...AND
ANOTHER SYSTEM LATER ON THE WEEKEND WITH SOME SNOW. THE CANADIAN
GGEM IS ALSO HINTING AT ANOTHER SYSTEM DEVELOPING SATURDAY NEXT
WEEKEND OVER THE CNTRL MS RIVER VALLEY THAT COULD IMPACT THE
NORTHEAST FOR SUNDAY TOO. MEANWHILE...THE GFS IS COLD AND DRY LATE
IN THE WEEK WITH A SHORT-WAVE TROUGH IN THE NW FLOW THAT COULD
PRODUCE SOME SOME SNOW SHOWERS LATER NEXT WEEKEND.
WED-WED NIGHT...HIGH PRESSURE RETREATS OFF THE MID ATLANTIC
COAST...AS A WAVE OF LOW PRESSURE MOVES ACROSS SRN QUEBEC. MOST OF
THE FCST AREA GETS INTO A WARM SECTOR WITH H850 TEMPS JUMPING UP TO
+1 TO +5C. MAX TEMPS COULD BE 10 TO 20 DEGREES ABOVE NORMAL WITH
HIGHS IN THE M40S TO L50S IN THE VALLEYS...AND LOWER TO M40S OVER
THE HILLS AND MTNS. THE COLD FRONT QUICKLY APPROACHES LATE IN THE
DAY INTO THE EVENING WITH A GOOD CHANCE OF SHOWERS...TRANSITIONING
TO SNOW SHOWERS WITH THE COLD AIR ADVECTION. WE KEPT THE TREND OF
LIKELY POPS NORTH OF THE CAPITAL REGION CLOSER TO THE BETTER
CONVERGENCE AND LIFT WITH THE WAVE AND FRONT. LOWS WILL RANGE FROM
THE LOWER TO M20S OVER THE MTNS...AND U20S TO L30S IN THE VALLEYS.
THU-THU NIGHT...THE GFS HAS HIGH PRESSURE BUILDING IN FROM SRN
QUEBEC WITH A BROAD LONGWAVE TROUGH OVER THE NRN TIER. THE ECMWF
HAS A SHORT-WAVE IN THE SRN STREAM PHASING INTO THE NRN STREAM NEAR
THE CNTRL MS RIVER VALLEY...AND MOVES IT INTO THE OHIO VALLEY BY
THURSDAY MORNING. THIS SYSTEM MOVES ALONG THE BAROCLINIC ZONE FROM
THE FRONTAL PASSAGE ON WED NIGHT. THE SFC WAVE MOVES NORTHEAST INTO
PA AND UPSTATE NY BY LATE IN THE DAY ON THU VIA THE ECMWF. THE HPC
GUIDANCE...AND GFS HAVE A SECONDARY COLD FRONT SLIP SOUTH OF THE
REGION DURING THE DAY...AND THE WAVE IS MUCH FLATTER PASSING SOUTH
OF THE REGION. WE KEPT MUCH OF THE DAY DRY ON THU WITH HIGH
PRESSURE IN CONTROL. WE DID ADD A SLIGHT CHC OF SNOW THU NIGHT
OVER MOST OF THE REGION IN THE GRIDDED FCST JUST IN CASE THE ECMWF
IS CORRECT HERE. LATER RUNS OF THE GFS COULD TREND FURTHER NORTHWARD
WITH THE ACTIVE W/SW FLOW ALOFT.
FRI-FRI NIGHT...THIS IS WHERE THE MEDIUM RANGE GUIDANCE CONTINUES TO
DIVERGE. THE HPC GUIDANCE AND GFS HAVE A COLD FRONT MOVING SOUTH
WITH HIGH PRESSURE RIDGING BACK IN WITH A NRN STREAM DISTURBANCE
DIGGING S/SE FROM THE UPPER MIDWEST. THE SUBTROPICAL JET/SRN STREAM
DISTURBANCE IS EJECTING OUT OF TX. WE KEPT SOME SLIGHT OR LOW CHC
POPS IN FOR SNOW SHOWERS OR LIGHT SNOW DURING THIS TIME FRAME WITH
THE FIRST WAVE MOVING INTO GULF OF MAINE AND THE CANADIAN
MARITIMES. THE ECMWF/CANADIAN GGEM/SOME GLOBAL ENSEMBLES MEMBERS
HAVE A AN IMPRESSIVE SYSTEM FORMING OVER THE SRN PLAINS/LOWER MS
RIVER VALLEY FRI NIGHT WITH A POSITIVELY TILTED LONGWAVE TROUGH
BEING CARVED OUT OVER THE CNTRL PLAINS.
SAT-SUN...VERY LOW CONFIDENCE FORECAST CONTINUES. CAN GGEM AND
ECMWF CONTINUES TO HAVE COASTAL WAVE MOVING NORTHEAST INTO MID
ATLANTIC REGION...AND SOUTH OF LONG ISLAND BY SUNDAY. THE 18Z HPC
GUIDANCE IS TRENDING FURTHER NORTH LATE SAT INTO SUNDAY WITH THE
WAVE. WE KEPT SLIGHT TO LOW CHC POPS IN FOR THE WEEKEND WITH SNOW
AS THE MAIN PTYPE /AS SUFFICIENTLY COLD ENOUGH AIR IS IMPLIED/. THE
TIMING AND EVOLUTION OF THE LATE WEEK INTO THE WEEKEND SYSTEMS IS
VERY UNCERTAIN. IT COULD BE VERY ACTIVE. TEMPS LOOK TO AVERAGE
NEAR NORMAL FOR FEBRUARY DURING THIS STRETCH.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BRIEFLY RIDGING IN FROM THE SOUTH THIS
AFTERNOON...BUT A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A
CLIPPER LOW IS APPROACHING FROM THE LOWER GREAT REGION. THE CLIPPER
AND ITS COLD FRONT WILL QUICKLY MOVE ACROSS ERN NY AND WRN NEW
ENGLAND TONIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN
QUEBEC FOR MONDAY.
VFR CONDITIONS ARE EXPECTED TO LAST INTO THE EARLY EVENING WITH
THICKENING CIRRUS AND A HIGH STRATUS DECK AT 5-6 KFT AGL AHEAD OF
THE CLIPPER. THE BEST CHANCE OF SNOW SHOWERS OR ISOLD SNOW SQUALLS
IMPACTING ANY TERMINALS WILL BE NORTH OF KALB TOWARD KGFL. WE
INCLUDED A PERIOD OF AT LEAST MVFR CONDITIONS THERE BTWN 05Z-09Z. WE
USED VCSH GROUPS STARTING AT 02Z THERE. FURTHER SOUTH WE KEPT A
VCSH GROUP AT KALB. TEMPOS MAY BE ADDED LATER TO ACCOUNT FOR A
BRIEF PERIOD OF MVFR/IFR CONDITIONS WITH ANY SNOW SHOWERS OR
SQUALLS. KPOU LOOKS TO BE FURTHER SOUTH AWAY FROM THE BETTER
CONVERGENCE WITH THE CLIPPER AND COLD FRONT...WHERE IT IS UNCERTAIN
OF ANY REDUCTION BELOW VFR LEVELS OR A VCSH IS NEEDED AT THIS TIME.
THE SNOW SHOWERS...FLURRIES AND ISOLD SQUALLS SHOULD BE EAST OF THE
HUDSON RIVER VALLEY AT 09Z. THE WINDS WILL INCREASE FROM THE W/NW
WITH VFR CONDITIONS AND SCT-BKN CIGS 4-5 KFT AGL.
THE WINDS WILL BE FROM THE W/SW THIS AFTERNOON AT 8-13 KTS WITH A
FEW GUSTS 20-25 KTS...AND THEN BACK TO THE S/SW AT AROUND 10 KTS
AHEAD OF THE CLIPPER. EXPECT THE WINDS TO SHIFT TO THE W/NW AT 8-15
KTS WITH THE COLD FRONTAL PASSAGE SHORTLY AFTER MIDNIGHT...AND
PERSIST INTO THE LATE MORNING. SOME GUSTS TO AROUND 25 KTS WILL BE
POSSIBLE AT KALB THROUGH THE MORNING IN THE WAKE OF THE FRONT.
OUTLOOK...
MON..VFR...SLIGHT CHC -SHSNS KALB-KGFL.
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE...ALTHOUGH SOME GAGE SITES REMAIN
IMPACTED BY ICE INCLUDING MCKN6. NO MAJOR PROBLEMS ARE EXPECTED ON
THE RIVERS THROUGH THE MID WEEK PERIOD...OTHER THAN THOSE AREAS
SUCH AS MCKN6 WHERE ICE JAMS ARE STILL A POSSIBILITY. THE
PRECIPITATION THROUGH THE MID WEEK PERIOD IS EXPECTED TO BE MAINLY
IN THE FORM OF SNOW WITH QPF AMOUNTS RANGING FROM A FEW HUNDREDTHS
OF AN INCH TO A QUARTER TO A THIRD OF AN INCH ACROSS NORTHWEST
PORTIONS OF THE HSA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ032-033-
038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11
NEAR TERM...11
SHORT TERM...11
LONG TERM...WASULA
AVIATION...WASULA
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
127 PM EST SUN JAN 29 2012
.SYNOPSIS...
THE PARADE OF FAST MOVING WEATHER SYSTEMS WILL CONTINUE ACROSS
THE NORTHEAST. HIGH PRESSURE RIDGED ALONG THE MID ATLANTIC COAST
WILL MOVE OFFSHORE THIS AFTERNOON...AS TWO COLD FRONTS WILL MOVE
ACROSS THE REGION THIS EVENING AND OVERNIGHT. ON MONDAY...HIGH
PRESSURE WILL BRIEFLY MOVE OVER THE NORTHEAST...THEN IT WILL SHIFT
OFFSHORE MONDAY NIGHT...AND A WARM FRONT WILL SET UP FROM THE
UPPER GREAT LAKES TO CAPE COD BY TUESDAY...PRODUCING SOME LIGHT
SNOW FOR THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1 PM EST...HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE
WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY FROM 4 PM THIS
AFTERNOON UNTIL 10 AM MONDAY MORNING. EXPECT SNOWFALL AMOUNTS
RANGING FROM 3 TO 8 INCHES IN THE ADVISORY AREA ALONG WITH BLOWING
SNOW AS WEST TO NORTHWEST WINDS OF 10 TO 20 MPH WITH GUSTS UP TO
25 MPH WILL BE COMMON WITH HIGHER GUSTS POSSIBLE WITH SOME SNOW
SQUALLS LATER THIS EVENING. THE NEXT CLIPPER TYPE SYSTEM HAS SOME
FAIRLY GOOD DYNAMICS WITH IT INCLUDING A STRONG VORT AXIS AND
LATEST IR SAT PICS ARE INDICATING COOLING CLOUD TOPS. THERE ALSO
COULD BE SOME EMBEDDED SNOW SQUALLS THIS EVENING AND EVEN AN
ISOLATED CHC OF SOME THUNDER SNOW ESPECIALLY CLOSER TO LAKE
ONTARIO AS THE SHOWALTER INDICES BRIEFLY GET BELOW ZERO. BOTH THE
HIRESWRF MODEL COMPOSITE REFLECTIVITY AND THE HRRR COL MAX
REFLECTIVITY HAVE REFLECTIVITY VALUES INDICATIVE OF SNOW SQUALLS
DURING THE LATE EVENING TO AROUND MIDNIGHT TIME FRAME. IF THESE
SNOW SQUALLS BECOME MORE CERTAIN SPS WILL LIKELY BE ISSUED.
AS OF 950 AM EST...WE CANCELED THE LAKE EFFECT SNOW ADVISORY FOR
NRN HERKIMER CTY...AS THE BAND AS SHIFTED NORTH OF THE AREA IN THE
BACKING LOW-LEVEL FLOW TO THE SW. THE BAND IS NOW IN THE ST
LAWRENCE RIVER VALLEY. SNOW TOTALS FROM THE LAKE EFFECT AND SNOW
SQUALLS THE PAST 12 TO 15 HOURS HAVE RANGED FROM 3 TO 7 INCHES
WITH SOME ISOLATED HIGHER AMOUNTS POSSIBLE. PLEASE SEE OUR LATEST
PNS STATEMENT.
THE TREND WILL BE FOR A BRIEF BREAK IN THE LATE MORNING INTO THE
EARLY PM FOR MOST OF THE REGION WITH THE RIDGING FROM THE SOUTH.
HOWEVER...ANOTHER POTENT SHORT-WAVE TROUGH IS APPROACHING FROM NRN
IL THIS MORNING. THIS STRONG UPPER LEVEL DISTURBANCE AND ITS
ASSOCIATED COLD FRONT WILL INCREASE THE CHANCE OF SNOW SHOWERS AND
ISOLD SQUALLS FROM WEST TO EAST LATE THIS AFTERNOON INTO THE
OVERNIGHT PERIOD. ONCE AGAIN...BASED ON THE 3-KM REF PRODUCT FROM
THE HRRR AND THE HIRES WRF FAVORS 00Z-03Z. THE HRRR IS FASTER WITH
A 22Z-01Z TIMING WITH THE FIRST BOUNDARY. A SECOND STRONGER
BOUNDARY WITH THE UPPER TROUGH...THE HRRR HAS APPROACHING
BTWN 03Z-06Z FOR THE FCST AREA. WE TRENDED THE SKY COVER TO PARTLY
TO MOSTLY SUNNY FROM THE HUDSON RIVER VALLEY EASTWARD INTO THE
EARLY TO MID PM...BEFORE THE CLOUD INCREASE AHEAD OF THE FIRST
FRONT. MAX TEMPS WILL STILL RUN ABOVE NORMAL WITH U30S TO L40S IN
THE VALLEYS...AND U20S TO M30S OVER THE MTNS. T/TD/RH/APPARENT
TEMP TRENDS WE REDONE BASED ON OBSERVATIONS. THE HIGHEST SNOW
ACCUMULATIONS WITH THIS DISTURBANCE LOOK LIKE THEY WILL BE NORTH
AND WEST OF OF THE CAPITAL REGION WITH 1 TO 4 INCHES POSSIBLE
/ESPECIALLY THE WRN DACKS AND WRN MOHAWK VALLEY/.
PREVIOUS NEAR TERM...
LAKE EFFECT BAND STILL PERSISTENT...AND SHOULD CONTINUE UNTIL WARM
ADVECTION BEGINS LATER THIS MORNING...WHEN THE BAND SHOULD BECOME
DISRUPTED. ALSO SOME ISOLATED SNOW SHOWERS AND FLURRIES STILL INTO
THE SCHOHARIE VALLEY. KEEPING THE SNOW IN THE FORECAST FOR THE
NEXT COUPLE OF HOURS IN THE SCHOHARIE VALLEY AND WESTERN MOHAWK
VALLEY...WHILE KEEPING THE NORTHERN HERKIMER AREA IN BETTER
CHANCES THROUGH THE MORNING. ONE REPORT OF JUST OVER A FOOT
WAS JUST RECEIVED...BUT KEEPING ADVISORY UP AS MOST AREAS SHOULD
SEE 7 INCHES OR LESS.
CLOUD COVER HIGHLY DEPENDENT ON LAKE EFFECT MOISTURE THIS MORNING
BUT THERE SHOULD BE LESS CLOUD COVER ONCE THE LAKE EFFECT BAND IS
DISRUPTED THIS AFTERNOON. SO...JUST SOME MINOR ADJUSTMENTS TO SKY
COVER AND TEMPERATURES THROUGH THIS MORNING.
PREV AFD BELOW...
LAKE EFFECT BAND STILL EXTENDING INTO THE WESTERN MOHAWK VALLEY AND
SOUTHERN ADIRONDACKS. IT IS A BIT CELLULAR AS THE DEPTH OF THE
MOISTURE AND INSTABILITY IS RELATIVELY DEEP...EVIDENT IN THE 00Z BUF
SOUNDING. THE BAND SHOULD CONTINUE TO BRING SNOW INTO THE AREA
THROUGH THE EXPIRATION OF THE WINTER WEATHER ADVISORY. SOME ISOLATED
REFLECTIVITIES ARE RESPECTABLE BUT BASED ON THERMAL PROFILES AND THE
RAPIDLY CHANGING CHARACTER OF THE BAND...SNOW RATIOS AND DURATION OF
HEAVIEST SNOW SEEMS TO SUGGEST SNOW SHOULD STAY WITHIN THE ADVISORY
RANGE. SNOWFALL AMOUNTS STILL LOOK TO BE UP TO 7 INCHES. SOME
ISOLATED SNOW SHOWER ACTIVITY ALSO EXTENDING INTO THE SCHOHARIE
VALLEY THROUGH THE EARLY MORNING HOURS BUT LIGHTER AND MORE
SCATTERED THAN THE SINGLE BAND TO THE NORTH.
WARM ADVECTION WILL BEGIN BY LATE MORNING...SO THE SINGLE BAND AND
THE SCATTERED ACTIVITY TO THE SOUTH IN THE SCHOHARIE VALLEY SHOULD
GET DISRUPTED AROUND OR SHORTLY AFTER SUNRISE. THERE SHOULD BE SOME
PERIODS OF SUN THROUGH AT LEAST THE MORNING...MAYBE INTO THE
AFTERNOON...ESPECIALLY IN EASTERN AREAS...DEPENDING ON HOW QUICKLY
THE NEXT SYSTEM APPROACHES FROM THE GREAT LAKES. BASED ON MIXING
POTENTIAL TODAY...HIGHS IN THE UPPER 30S TO MID 40S BEFORE CLOUD
COVER ARRIVES. HIGHS IN THE LOWER TO MID 30S IN THE SOUTHERN
ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS.
NEXT QUICK MOVING NORTHERN STREAM SYSTEM TRACKS THROUGH THE REGION
TONIGHT...WHICH LOOKS TO BE RELATIVELY MOISTURE STARVED...EXCEPT FOR
WHAT COULD BE PICKED UP OFF THE GREAT LAKES. STILL...MOSTLY CLOUDY
MUCH OF THE NIGHT...WITH THE MOST WIDESPREAD SNOW SHOWER ACTIVITY IN
THE WESTERN MOHAWK VALLEY AND SOUTHERN ADIRONDACKS. SCATTERED
ACTIVITY SHOULD MAKE IT INTO MOST OF THE REGION...WITH MORE ISOLATED
ACTIVITY IN THE MID HUDSON VALLEY..SOUTHERN BERKSHIRES AND NW CT.
THERE COULD BE 1 TO 3 INCHES OF SNOW IN THE NORTHERN AREAS WITH
LOCAL DUSTINGS POSSIBLE ACROSS THE REST OF THE REGION. SOME PARTIAL
CLEARING IS POSSIBLE TOWARD SUNRISE...BUT GUSTY WEST TO NORTHWEST
WINDS SHOULD BEGIN AS THE SYSTEM EXITS LATE TONIGHT. LOWS IN THE
20S...BUT A LITTLE HIGHER THAN GUIDANCE NUMBERS DUE TO THE WINDS AND
MIXING. SOME LOWS IN THE TEENS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
BACK DOOR CDFNT PUSHES SOUTH INTO FCA AS 500HPA SHORT WVS MOVE
EAST ACROSS NEW YORK NEW ENG. THIS WILL BRING A BRIEF PERIOD OF
COLD AIR AND REINVIGORATE LK EFFECT BAND INTO TUG HILL/W ADNDKS.
BY MON NT. LATE MONDAY INTO TUES EASTERN TROF DEPARTS...RIDGING
BUILDS FROM GRTLKS TO SE STATES AND A 500HPA SHORT WAVE EJECTS INTO
NORTHERN GREAT PLAINS. THIS SETS UP FRONTOGENESIS AS WMFNT ORGANIZES
DLH-BOS. MONDAY AND MONDAY NIGHTS CLOUDS BLOOM ALL ALONG AND AHEAD OF
IT...AND OVERRUNNING SNOW BREAKS OUT ACROSS THE GRTLKS.
MON NT INTO TUE MORNING THIS -SN SPREADS ACROSS NY/NEW ENG. THE
NAM/GFS/ECMWF ARE SIMILAR BUT NAM QPF IS DEFINITELY LIGHTER. THE
GEM HAS BULK OF PCPN N OF FCA. AS THE 500HPA FLOW TURNS SW THE
MODEL SUIT GENERALLY LIFTS TO WMFNT OUT OF THE FCA TUE
EVNG...LEAVING AREA IN WARM SECTOR WITH -SHRA THREAT TILL CDFNT
MOVES THROUGH WED. THEY ALL TAKE MAJOR CYCLONE WITH THIS SYSTEM
WELL NORTH INTO ONT/QB.
TEMPS ARE GENERALLY ABV NORMAL TO MUCH ABV DURING THIS PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE FAST MOVING PATTERN CONTINUES WITH A SHORT WV MOVING THROUGH
THUR TRIGGERING ISOLD TO SCT -SHSN...MORE NEAR THE LAKE. HIGH
PRESSURE RIDGES SOUTH TO END THE WEEK WITH DRY CONDS...THEN THE
MODELS TAKE THE BIG DIVERGE. THE GFS PRODUCES A SIGNIFICANT
COASTAL LOW...AS USUAL BASED ON THE PHASING OF SHORT WAVES THAT
ARE SCATTERED ALL OVER EAST ASIA. THE ECMWF TAKES THIS STORM...NOT
UP THE EAST COAST...BUT UP THE ST LAWRENCE VLY. THE MODEL SUITE
HAS BEEN ALL OVER WITH THIS SYSTEM FROM IN THE WEST ATLC. FOR NOW
CARRIED CHC OR SLIGHT CHC. THERE`S 6 DAYS TO THE MODELS TO DEBATE
WITH THEMSELVES HOW THE SHORT WVS WILL PHASE. TEMPS DURING THE EFO
WILL BEGIN ABV NORMALS THU AND END THE PERIOD NEAR NORMAL.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BRIEFLY RIDGING IN FROM THE SOUTH THIS
AFTERNOON...BUT A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A
CLIPPER LOW IS APPROACHING FROM THE LOWER GREAT REGION. THE CLIPPER
AND ITS COLD FRONT WILL QUICKLY MOVE ACROSS ERN NY AND WRN NEW
ENGLAND TONIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN
QUEBEC FOR MONDAY.
VFR CONDITIONS ARE EXPECTED TO LAST INTO THE EARLY EVENING WITH
THICKENING CIRRUS AND A HIGH STRATUS DECK AT 5-6 KFT AGL AHEAD OF
THE CLIPPER. THE BEST CHANCE OF SNOW SHOWERS OR ISOLD SNOW SQUALLS
IMPACTING ANY TERMINALS WILL BE NORTH OF KALB TOWARD KGFL. WE
INCLUDED A PERIOD OF AT LEAST MVFR CONDITIONS THERE BTWN 05Z-09Z. WE
USED VCSH GROUPS STARTING AT 02Z THERE. FURTHER SOUTH WE KEPT A
VCSH GROUP AT KALB. TEMPOS MAY BE ADDED LATER TO ACCOUNT FOR A
BRIEF PERIOD OF MVFR/IFR CONDITIONS WITH ANY SNOW SHOWERS OR
SQUALLS. KPOU LOOKS TO BE FURTHER SOUTH AWAY FROM THE BETTER
CONVERGENCE WITH THE CLIPPER AND COLD FRONT...WHERE IT IS UNCERTAIN
OF ANY REDUCTION BELOW VFR LEVELS OR A VCSH IS NEEDED AT THIS TIME.
THE SNOW SHOWERS...FLURRIES AND ISOLD SQUALLS SHOULD BE EAST OF THE
HUDSON RIVER VALLEY AT 09Z. THE WINDS WILL INCREASE FROM THE W/NW
WITH VFR CONDITIONS AND SCT-BKN CIGS 4-5 KFT AGL.
THE WINDS WILL BE FROM THE W/SW THIS AFTERNOON AT 8-13 KTS WITH A
FEW GUSTS 20-25 KTS...AND THEN BACK TO THE S/SW AT AROUND 10 KTS
AHEAD OF THE CLIPPER. EXPECT THE WINDS TO SHIFT TO THE W/NW AT 8-15
KTS WITH THE COLD FRONTAL PASSAGE SHORTLY AFTER MIDNIGHT...AND
PERSIST INTO THE LATE MORNING. SOME GUSTS TO AROUND 25 KTS WILL BE
POSSIBLE AT KALB THROUGH THE MORNING IN THE WAKE OF THE FRONT.
OUTLOOK...
MON..VFR...SLIGHT CHC -SHSNS KALB-KGFL.
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE. A CLIPPER LOW PRESSURE SYSTEM AND
TWO COLD FRONTS WILL IMPACT THE REGION THIS EVENING INTO MONDAY
MORNING. SOME SCATTERED SNOW SHOWERS AND FLURRIES WILL BE COMMON
WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW INCHES IN THE SOUTHERN
ADIRONDACKS. A WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY
NIGHT INTO TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK
ADN ANY RAINFALL THAT OCCURS WILL BE LIGHT AND MOST PRECIPITATION
DURING THE WEEK WILL BE LIGHT SNOW.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ032-033-
038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER/WASULA
NEAR TERM...11/NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...WASULA
HYDROLOGY...NAS/WASULA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
117 PM EST SUN JAN 29 2012
.SYNOPSIS...
HIGH PRESSURE WILL BE SITUATED OVER THE TRI STATE AREA TODAY. A
COLD FRONT PASSES THROUGH TONIGHT. HIGH PRESSURE RETURNS ON
MONDAY. A WARM FRONT APPROACHES MONDAY NIGHT AND LIFTS NORTH OF US
TUESDAY MORNING. A COLD FRONT FOLLOWS WEDNESDAY INTO WEDNESDAY
NIGHT. ADDITIONAL STORM SYSTEMS MAY AFFECT THE REGION LATE IN THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LITTLE CHANGE TO TEMPS/DEWPOINTS AS THEY SEEM TO BE ON TRACK THIS
AFTERNOON. WINDS ADJUSTED SLIGHTLY DOWNWARD TO ACCOUNT FOR CURRENT
TRENDS.
HIGH PRESSURE FROM THE SOUTH AND WEST BUILDS IN TODAY AND OFFSHORE
GOING INTO THIS EVENING. WEST TO SOUTHWEST WINDS WITH GOOD
VERTICAL MIXING UP TO ABOUT 800 MB STILL EXPECTED. ACARS SOUNDINGS
INDICATE MIXING UP TO 900 MB SO FAR AND GFS AND RUC BUFKIT
SOUNDINGS INDICATE A JUMP IN VERTICAL MIXING TO AROUND 800 MB AT
LEAST FOR THIS AFTERNOON BETWEEN 3 AND 5 PM. ADIABATICALLY MIXING
DOWN TO SURFACE TEMPS WITH SOME LOWERING FACTORS CONSIDERING MID
AND HIGH LEVEL CLOUDS COMING IN FROM THE WEST...YIELDS A END
RESULT RANGING OF HIGHS FROM LOWER 40S ACROSS INTERIOR ELEVATED
LOCATIONS TO THE MID AND UPPER 40S ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
LONGWAVE TROUGH AXIS APPROACHES US TONIGHT WITH A VIGOROUS
SHORTWAVE MOVING ALONG ITS BASE. THIS SHORTWAVE IS PROGGED TO
PASS RIGHT OVER THE CWA TONIGHT. AN ACCOMPANYING COLD FRONT WILL
ALSO BE MOVING THROUGH THE REGION. HAVE GONE ABOVE GUIDANCE POPS
AND WENT WITH A 30 PERCENT CHANCE OF PRECIP. WITH SUCH A VIGOROUS
SHORTWAVE MOVING THROUGH...INSTABILITY ALOFT WILL INCREASE WITH
THE STRONG COLD ADVECTION. MODELS SHOWING LAPSE RATES OF AROUND
8-9 C/KM IN THE 850-500MB LAYER PASSING THROUGH TONIGHT. ALTHOUGH
MODELS DO NOT NECESSARILY SHOW DEEP MOISTURE DURING THE TIME THAT
THIS SYSTEM MOVES THROUGH...THINKING IS THAT THIS INSTABILITY AND
LIFT WILL BE ABLE TO MAKE EFFICIENT USE OF THE AVAILABLE MOISTURE.
00Z SPC WRF AND NAM FORECAST 1KM REFLECTIVITY EVEN DEPICT A
BROKEN SQUALL LINE MOVING THROUGH THE REGION TONIGHT...PICKING UP
MOISTURE APPARENTLY FROM THE COASTAL WATERS AS IT PASSES THROUGH.
THERMAL PROFILES SUPPORT SNOW SHOWERS NORTH OF THE CITY...AND A
RAIN/SNOW SHOWER MIX FOR THE CITY/ADJACENT SUBURBS AND LONG
ISLAND. WHERE IT DOES REMAIN ALL SNOW...A LIGHT COATING OF SNOW
WILL BE POSSIBLE. 30-35 MPH GUSTS WILL BE POSSIBLE TO BEHIND THE
COLD FRONT WITH THE STRONG COLD ADVECTION.
HIGH PRESSURE AND DRY WEATHER FOR MONDAY. MAV/NAM MOS BLEND LOOKED
GOOD AGAIN FOR TEMPS. A WARM FRONT THEN APPROACHES MONDAY
NIGHT...AND WITH THE NAM TYPICALLY BETTER AT HOLDING IN COLD AIR
DUE TO DAMMING...WILL GO WITH ITS IDEA THAT THE FRONT DOES NOT
MOVE NORTH OF US UNTIL TUESDAY MORNING. ISENTROPIC LIFT AHEAD OF
THE FRONT MAY PRODUCE SOME LIGHT SNOWFALL FOR PART OF THE CWA.
KEPT IN SLIGHT CHANCE POPS MONDAY NIGHT...BUT DRY OVER THE SW
CORNER OF THE CWA AS PER MODEL AGREEMENT. A NON DIURNAL
TEMPERATURE TREND WAS USED...CONSIDERING CLOUDS THICKENING THROUGH
THE NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
A MILD AND DRY DAY ANTICIPATED ON TUESDAY WITH A WARM FRONT LIFTING
TO THE NORTH. HIGHS REACHING THE MID 50S ACROSS THE WARMEST
SPOTS. A COLD FRONT THEN APPROACHES FROM THE WEST...BRINGING A
CHANCE OF RAIN SHOWERS LATE TUESDAY NIGHT. MODELS AGREE THAT THE
FRONT MOVES THROUGH LATE WEDNESDAY INTO WEDNESDAY NIGHT WITH A
CONTINUED THREAT OF SHOWERS.
MODELS CONTINUE TO DIVERGE REGARDING THE FORECAST FROM THURSDAY ON.
AFTER COLLABORATION WITH THE SURROUNDING OFFICES...HAVE MOSTLY LEFT
THIS PORTION OF THE FORECAST ALONE. GENERALLY LEANING TOWARDS THE
IDEA DEPICTED BY HPC...WHERE WEAK LOW PRESSURE APPROACHES FROM THE
WEST ON THURSDAY...THEN PASSES NEARBY THURSDAY NIGHT INTO FRIDAY.
LONGWAVE TROUGHING OVER THE REGION WOULD THEN FOLLOW ON
SATURDAY...WITH A COLD FRONT OR LOW PRESSURE SYSTEM POTENTIALLY
AFFECTING THE AREA.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
RIDGE OF HIGH PRESSURE TO THE EAST WEAKENS AS A COLD FRONT
APPROACHES THROUGH EARLY THIS EVENING. THE FRONT CROSSES THE
TERMINALS FROM ABOUT 05Z THROUGH 10Z. HIGH PRESSURE BUILDS BEHIND
THE FRONT MONDAY.
VFR THROUGH THE TAF PERIOD. MAINLY DRY...HOWEVER THERE IS A CHANCE
OF SCATTERED SNOW SHOWERS WITH THE FRONT. BEST CHANCE WILL BE AT
KSWF WHERE LOW END VFR TO HIGH END MVFR CONDITIONS WILL BE POSSIBLE
FROM 05Z TO 08Z.
GUSTY WESTERLY WINDS GRADUALLY BECOME MORE SOUTHWEST BY LATE
AFTERNOON. WITH THE PASSAGE OF THE FRONT WINDS SHIFT BACK TO WEST
AND GUSTS INCREASE FOR A TIME...NEARING 30 KTS.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
MONDAY THROUGH TUESDAY...VFR. GUSTY WESTERLY WINDS MONDAY.
WEDNESDAY...SUB-VFR POSSIBLE IN RAIN.
THURSDAY...VFR.
FRIDAY...LOW CHANCE OF SUB VFR.
&&
.MARINE...
LAST UPDATE...WITH LOWERING TREND TO WINDS AND SEAS BELOW
SCA...DROPPED SCA FOR WESTERN WATERS...BUT KEPT IT FOR EASTERN LI
SOUND AND BAYS AS WELL AS OCEAN WATERS SOUTH OF LONG ISLAND EAST
OF FIRE ISLAND INLET FOR REMAINDER OF AFTERNOON.
IN THE WAKE OF A COLD FRONT CROSSING THE WATERS THIS
EVENING...WINDS VEER TO THE W...WITH GUSTS LIKELY REACHING GALE
FORCE OVERNIGHT. AS A RESULT HAVE ISSUED A GALE WATCH FOR ALL
WATERS TONIGHT.
WIND GUSTS SHOULD DIMINISH TO SCA LEVELS BY MONDAY
MORNING...EXCEPT ON THE COASTAL OCEAN ZONES...WHERE GALES SHOULD
COULD LINGER THROUGH THE MORNING. SCA GUSTS COULD QUITE POSSIBLY
CONTINUE THROUGH THE DAY ON ALL WATERS MONDAY.
MONDAY NIGHT SHOULD SEE ALL BUT THE TWO EASTERN COASTAL OCEAN
ZONES HAVE CONDITIONS FALL BELOW SCA LEVELS. STILL COULD SEE SCA
GUSTS AT LEAST INTO THE EVENING IN THE EASTERN COASTAL
WATERS...WITH FAR EASTERN WATERS POSSIBLY MAINTAINING SCA LEVEL
GUSTS AND SEAS THROUGH THE NIGHT.
THE BATTLE IS THEN ON BETWEEN STRONG WINDS 950-850 HPA AND A LOW
LEVEL INVERSION TUESDAY-WEDNESDAY FOR NOW KEEP GUSTS TO AT MOST
SCA LEVELS...BUT POTENTIAL FOR GALES CANNOT BE COMPLETELY RULED
OUT IN THIS TIME FRAME.
HIGH PRESSURE BUILDS IN WEDNESDAY NIGHT-THURSDAY...SO SUB-SCA
CONDITIONS FORECAST.
&&
.HYDROLOGY...
ANY LIQUID EQUIVALENT PRECIPITATION THROUGH WEDNESDAY IS EXPECTED
TO BE ON THE LIGHT SIDE.
&&
.EQUIPMENT...
THE WEATHER OBSERVATION FROM CENTRAL PARK WILL BE UNAVAILABLE
UNTIL FURTHER NOTICE. THIS IS DUE TO A SIGNIFICANT POWER
INTERRUPTION TO THE CENTRAL PARK AUTOMATED SURFACE OBSERVING
STATION /ASOS/ AND BACKUP STATION. UTILITY WORKERS ARE ADDRESSING
THE PROBLEM...BUT THERE IS CURRENTLY NO ESTIMATED TIME FOR RETURN
TO SERVICE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WATCH FROM 6 PM EST THIS EVENING THROUGH LATE TONIGHT FOR
ANZ330-335-338-340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-
340-350-353.
&&
$$
SYNOPSIS...
NEAR TERM...JM
SHORT TERM...
LONG TERM...
AVIATION...MET
MARINE...JM/MALOIT
HYDROLOGY...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
104 PM EST SUN JAN 29 2012
.SYNOPSIS...
THE PARADE OF FAST MOVING WEATHER SYSTEMS WILL CONTINUE
ACROSS THE NORTHEAST. HIGH PRESSURE RIDGED ALONG THE MID ATLANTIC
COAST WILL MOVE OFFSHORE THIS AFTERNOON...AS TWO COLD FRONTS WILL
MOVE ACROSS THE REGION THIS EVENING AND OVERNIGHT. ON MONDAY...HIGH
PRESSURE WILL BRIEFLY MOVE OVER THE NORTHEAST...THEN IT WILL SHIFT
OFFSHORE MONDAY NIGHT...AND A WARM FRONT WILL SET UP FROM THE UPPER
GREAT LAKES TO CAPE COD BY TUESDAY...PRODUCING SOME LIGHT SNOW FOR
THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EST...WE CANCELED THE LAKE EFFECT SNOW ADVISORY FOR
NRN HERKIMER CTY...AS THE BAND AS SHIFTED NORTH OF THE AREA IN THE
BACKING LOW-LEVEL FLOW TO THE SW. THE BAND IS NOW IN THE ST
LAWRENCE RIVER VALLEY. SNOW TOTALS FROM THE LAKE EFFECT AND SNOW
SQUALLS THE PAST 12 TO 15 HOURS HAVE RANGED FROM 3 TO 7 INCHES
WITH SOME ISOLATED HIGHER AMOUNTS POSSIBLE. PLEASE SEE OUR LATEST
PNS STATEMENT.
THE TREND WILL BE FOR A BRIEF BREAK IN THE LATE MORNING INTO THE
EARLY PM FOR MOST OF THE REGION WITH THE RIDGING FROM THE SOUTH.
HOWEVER...ANOTHER POTENT SHORT-WAVE TROUGH IS APPROACHING FROM NRN
IL THIS MORNING. THIS STRONG UPPER LEVEL DISTURBANCE AND ITS
ASSOCIATED COLD FRONT WILL INCREASE THE CHANCE OF SNOW SHOWERS AND
ISOLD SQUALLS FROM WEST TO EAST LATE THIS AFTERNOON INTO THE
OVERNIGHT PERIOD. ONCE AGAIN...BASED ON THE 3-KM REF PRODUCT FROM
THE HRRR AND THE HIRES WRF FAVORS 00Z-03Z. THE HRRR IS FASTER WITH
A 22Z-01Z TIMING WITH THE FIRST BOUNDARY. A SECOND STRONGER
BOUNDARY WITH THE UPPER TROUGH...THE HRRR HAS APPROACHING
BTWN 03Z-06Z FOR THE FCST AREA. WE TRENDED THE SKY COVER TO PARTLY
TO MOSTLY SUNNY FROM THE HUDSON RIVER VALLEY EASTWARD INTO THE
EARLY TO MID PM...BEFORE THE CLOUD INCREASE AHEAD OF THE FIRST
FRONT. MAX TEMPS WILL STILL RUN ABOVE NORMAL WITH U30S TO L40S IN
THE VALLEYS...AND U20S TO M30S OVER THE MTNS. T/TD/RH/APPARENT
TEMP TRENDS WE REDONE BASED ON OBSERVATIONS. THE HIGHEST SNOW
ACCUMULATIONS WITH THIS DISTURBANCE LOOK LIKE THEY WILL BE NORTH
AND WEST OF OF THE CAPITAL REGION WITH 1 TO 4 INCHES POSSIBLE
/ESPECIALLY THE WRN DACKS AND WRN MOHAWK VALLEY/.
PREVIOUS NEAR TERM...
LAKE EFFECT BAND STILL PERSISTENT...AND SHOULD CONTINUE UNTIL WARM
ADVECTION BEGINS LATER THIS MORNING...WHEN THE BAND SHOULD BECOME
DISRUPTED. ALSO SOME ISOLATED SNOW SHOWERS AND FLURRIES STILL INTO
THE SCHOHARIE VALLEY. KEEPING THE SNOW IN THE FORECAST FOR THE
NEXT COUPLE OF HOURS IN THE SCHOHARIE VALLEY AND WESTERN MOHAWK
VALLEY...WHILE KEEPING THE NORTHERN HERKIMER AREA IN BETTER
CHANCES THROUGH THE MORNING. ONE REPORT OF JUST OVER A FOOT
WAS JUST RECEIVED...BUT KEEPING ADVISORY UP AS MOST AREAS SHOULD
SEE 7 INCHES OR LESS.
CLOUD COVER HIGHLY DEPENDENT ON LAKE EFFECT MOISTURE THIS MORNING
BUT THERE SHOULD BE LESS CLOUD COVER ONCE THE LAKE EFFECT BAND IS
DISRUPTED THIS AFTERNOON. SO...JUST SOME MINOR ADJUSTMENTS TO SKY
COVER AND TEMPERATURES THROUGH THIS MORNING.
PREV AFD BELOW...
LAKE EFFECT BAND STILL EXTENDING INTO THE WESTERN MOHAWK VALLEY AND
SOUTHERN ADIRONDACKS. IT IS A BIT CELLULAR AS THE DEPTH OF THE
MOISTURE AND INSTABILITY IS RELATIVELY DEEP...EVIDENT IN THE 00Z BUF
SOUNDING. THE BAND SHOULD CONTINUE TO BRING SNOW INTO THE AREA
THROUGH THE EXPIRATION OF THE WINTER WEATHER ADVISORY. SOME ISOLATED
REFLECTIVITIES ARE RESPECTABLE BUT BASED ON THERMAL PROFILES AND THE
RAPIDLY CHANGING CHARACTER OF THE BAND...SNOW RATIOS AND DURATION OF
HEAVIEST SNOW SEEMS TO SUGGEST SNOW SHOULD STAY WITHIN THE ADVISORY
RANGE. SNOWFALL AMOUNTS STILL LOOK TO BE UP TO 7 INCHES. SOME
ISOLATED SNOW SHOWER ACTIVITY ALSO EXTENDING INTO THE SCHOHARIE
VALLEY THROUGH THE EARLY MORNING HOURS BUT LIGHTER AND MORE
SCATTERED THAN THE SINGLE BAND TO THE NORTH.
WARM ADVECTION WILL BEGIN BY LATE MORNING...SO THE SINGLE BAND AND
THE SCATTERED ACTIVITY TO THE SOUTH IN THE SCHOHARIE VALLEY SHOULD
GET DISRUPTED AROUND OR SHORTLY AFTER SUNRISE. THERE SHOULD BE SOME
PERIODS OF SUN THROUGH AT LEAST THE MORNING...MAYBE INTO THE
AFTERNOON...ESPECIALLY IN EASTERN AREAS...DEPENDING ON HOW QUICKLY
THE NEXT SYSTEM APPROACHES FROM THE GREAT LAKES. BASED ON MIXING
POTENTIAL TODAY...HIGHS IN THE UPPER 30S TO MID 40S BEFORE CLOUD
COVER ARRIVES. HIGHS IN THE LOWER TO MID 30S IN THE SOUTHERN
ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS.
NEXT QUICK MOVING NORTHERN STREAM SYSTEM TRACKS THROUGH THE REGION
TONIGHT...WHICH LOOKS TO BE RELATIVELY MOISTURE STARVED...EXCEPT FOR
WHAT COULD BE PICKED UP OFF THE GREAT LAKES. STILL...MOSTLY CLOUDY
MUCH OF THE NIGHT...WITH THE MOST WIDESPREAD SNOW SHOWER ACTIVITY IN
THE WESTERN MOHAWK VALLEY AND SOUTHERN ADIRONDACKS. SCATTERED
ACTIVITY SHOULD MAKE IT INTO MOST OF THE REGION...WITH MORE ISOLATED
ACTIVITY IN THE MID HUDSON VALLEY..SOUTHERN BERKSHIRES AND NW CT.
THERE COULD BE 1 TO 3 INCHES OF SNOW IN THE NORTHERN AREAS WITH
LOCAL DUSTINGS POSSIBLE ACROSS THE REST OF THE REGION. SOME PARTIAL
CLEARING IS POSSIBLE TOWARD SUNRISE...BUT GUSTY WEST TO NORTHWEST
WINDS SHOULD BEGIN AS THE SYSTEM EXITS LATE TONIGHT. LOWS IN THE
20S...BUT A LITTLE HIGHER THAN GUIDANCE NUMBERS DUE TO THE WINDS AND
MIXING. SOME LOWS IN THE TEENS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
BACK DOOR CDFNT PUSHES SOUTH INTO FCA AS 500HPA SHORT WVS MOVE
EAST ACROSS NEW YORK NEW ENG. THIS WILL BRING A BRIEF PERIOD OF
COLD AIR AND REINVIGORATE LK EFFECT BAND INTO TUG HILL/W ADNDKS.
BY MON NT. LATE MONDAY INTO TUES EASTERN TROF DEPARTS...RIDGING
BUILDS FROM GRTLKS TO SE STATES AND A 500HPA SHORT WAVE EJECTS INTO
NORTHERN GREAT PLAINS. THIS SETS UP FRONTOGENESIS AS WMFNT ORGANIZES
DLH-BOS. MONDAY AND MONDAY NIGHTS CLOUDS BLOOM ALL ALONG AND AHEAD OF
IT...AND OVERRUNNING SNOW BREAKS OUT ACROSS THE GRTLKS.
MON NT INTO TUE MORNING THIS -SN SPREADS ACROSS NY/NEW ENG. THE
NAM/GFS/ECMWF ARE SIMILAR BUT NAM QPF IS DEFINITELY LIGHTER. THE
GEM HAS BULK OF PCPN N OF FCA. AS THE 500HPA FLOW TURNS SW THE
MODEL SUIT GENERALLY LIFTS TO WMFNT OUT OF THE FCA TUE
EVNG...LEAVING AREA IN WARM SECTOR WITH -SHRA THREAT TILL CDFNT
MOVES THROUGH WED. THEY ALL TAKE MAJOR CYCLONE WITH THIS SYSTEM
WELL NORTH INTO ONT/QB.
TEMPS ARE GENERALLY ABV NORMAL TO MUCH ABV DURING THIS PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE FAST MOVING PATTERN CONTINUES WITH A SHORT WV MOVING THROUGH
THUR TRIGGERING ISOLD TO SCT -SHSN...MORE NEAR THE LAKE. HIGH
PRESSURE RIDGES SOUTH TO END THE WEEK WITH DRY CONDS...THEN THE
MODELS TAKE THE BIG DIVERGE. THE GFS PRODUCES A SIGNIFICANT
COASTAL LOW...AS USUAL BASED ON THE PHASING OF SHORT WAVES THAT
ARE SCATTERED ALL OVER EAST ASIA. THE ECMWF TAKES THIS STORM...NOT
UP THE EAST COAST...BUT UP THE ST LAWRENCE VLY. THE MODEL SUITE
HAS BEEN ALL OVER WITH THIS SYSTEM FROM IN THE WEST ATLC. FOR NOW
CARRIED CHC OR SLIGHT CHC. THERE`S 6 DAYS TO THE MODELS TO DEBATE
WITH THEMSELVES HOW THE SHORT WVS WILL PHASE. TEMPS DURING THE EFO
WILL BEGIN ABV NORMALS THU AND END THE PERIOD NEAR NORMAL.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BRIEFLY RIDGING IN FROM THE SOUTH THIS
AFTERNOON...BUT A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A
CLIPPER LOW IS APPROACHING FROM THE LOWER GREAT REGION. THE CLIPPER
...AND ITS COLD FRONT WILL QUICKLY MOVE ACROSS ERN NY AND WRN NEW
ENGLAND TONIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN
QUEBEC FOR MONDAY.
VFR CONDITIONS ARE EXPECTED TO LAST INTO THE EARLY EVENING WITH
THICKENING CIRRUS AND A HIGH STRATUS DECK AT 5-6 KFT AGL AHEAD OF
THE CLIPPER. THE BEST CHANCE OF SNOW SHOWERS OR ISOLD SNOW SQUALLS
IMPACTING ANY TERMINALS WILL BE NORTH OF KALB TOWARD KGFL. WE
INCLUDED A PERIOD OF AT LEAST MVFR CONDITIONS THERE BTWN 05Z-09Z. WE
USED VCSH GROUPS STARTING AT 02Z THERE. FURTHER SOUTH WE KEPT A
VCSH GROUP AT KALB. TEMPOS MAY BE ADDED LATER TO ACCOUNT FOR A
BRIEF PERIOD OF MVFR/IFR CONDITIONS WITH ANY SNOW SHOWERS OR
SQUALLS. KPOU LOOKS TO BE FURTHER SOUTH AWAY FROM THE BETTER
CONVERGENCE WITH THE CLIPPER AND COLD FRONT...WHERE IT IS UNCERTAIN
OF ANY REDUCTION BELOW VFR LEVELS OR A VCSH IS NEEDED AT THIS TIME.
THE SNOW SHOWERS...FLURRIES AND ISOLD SQUALLS SHOULD BE EAST OF THE
HUDSON RIVER VALLEY AT 09Z. THE WINDS WILL INCREASE FROM THE W/NW
WITH VFR CONDITIONS AND SCT-BKN CIGS 4-5 KFT AGL.
THE WINDS WILL BE FROM THE W/SW THIS AFTERNOON AT 8-13 KTS WITH A
FEW GUSTS 20-25 KTS...AND THEN BACK TO THE S/SW AT AROUND 10 KTS
AHEAD OF THE CLIPPER. EXPECT THE WINDS TO SHIFT TO THE W/NW AT 8-15
KTS WITH THE COLD FRONTAL PASSAGE SHORTLY AFTER MIDNIGHT...AND
PERSIST INTO THE LATE MORNING. SOME GUSTS TO AROUND 25 KTS WILL BE
POSSIBLE AT KALB THROUGH THE MORNING IN THE WAKE OF THE FRONT.
OUTLOOK...
MON..VFR...SLIGHT CHC -SHSNS KALB-KGFL.
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE. A CLIPPER LOW PRESSURE SYSTEM AND
TWO COLD FRONTS WILL IMPACT THE REGION THIS EVENING INTO MONDAY
MORNING. SOME SCATTERED SNOW SHOWERS AND FLURRIES WILL BE COMMON
WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW INCHES IN THE SOUTHERN
ADIRONDACKS. A WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY
NIGHT INTO TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK
ADN ANY RAINFALL THAT OCCURS WILL BE LIGHT AND MOST PRECIPITATION
DURING THE WEEK WILL BE LIGHT SNOW.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ032-033-
038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER/WASULA
NEAR TERM...NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...WASULA
HYDROLOGY...NAS/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1013 AM EST SUN JAN 29 2012
.SYNOPSIS...
THE PARADE OF FAST MOVING WEATHER SYSTEMS WILL CONTINUE
ACROSS THE NORTHEAST. HIGH PRESSURE RIDGED ALONG THE MID ATLANTIC
COAST WILL MOVE OFFSHORE THIS AFTERNOON...AS TWO COLD FRONTS WILL
MOVE ACROSS THE REGION THIS EVENING AND OVERNIGHT. ON MONDAY...HIGH
PRESSURE WILL BRIEFLY MOVE OVER THE NORTHEAST...THEN IT WILL SHIFT
OFFSHORE MONDAY NIGHT...AND A WARM FRONT WILL SET UP FROM THE UPPER
GREAT LAKES TO CAPE COD BY TUESDAY...PRODUCING SOME LIGHT SNOW FOR
THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EST...WE CANCELED THE LAKE EFFECT SNOW ADVISORY FOR
NRN HERKIMER CTY...AS THE BAND AS SHIFTED NORTH OF THE AREA IN THE
BACKING LOW-LEVEL FLOW TO THE SW. THE BAND IS NOW IN THE ST
LAWRENCE RIVER VALLEY. SNOW TOTALS FROM THE LAKE EFFECT AND SNOW
SQUALLS THE PAST 12 TO 15 HOURS HAVE RANGED FROM 3 TO 7 INCHES
WITH SOME ISOLATED HIGHER AMOUNTS POSSIBLE. PLEASE SEE OUR LATEST
PNS STATEMENT.
THE TREND WILL BE FOR A BRIEF BREAK IN THE LATE MORNING INTO THE
EARLY PM FOR MOST OF THE REGION WITH THE RIDGING FROM THE SOUTH.
HOWEVER...ANOTHER POTENT SHORT-WAVE TROUGH IS APPROACHING FROM NRN
IL THIS MORNING. THIS STRONG UPPER LEVEL DISTURBANCE AND ITS
ASSOCIATED COLD FRONT WILL INCREASE THE CHANCE OF SNOW SHOWERS AND
ISOLD SQUALLS FROM WEST TO EAST LATE THIS AFTERNOON INTO THE
OVERNIGHT PERIOD. ONCE AGAIN...BASED ON THE 3-KM REF PRODUCT FROM
THE HRRR AND THE HIRES WRF FAVORS 00Z-03Z. THE HRRR IS FASTER WITH
A 22Z-01Z TIMING WITH THE FIRST BOUNDARY. A SECOND STRONGER
BOUNDARY WITH THE UPPER TROUGH...THE HRRR HAS APPROACHING
BTWN 03Z-06Z FOR THE FCST AREA. WE TRENDED THE SKY COVER TO PARTLY
TO MOSTLY SUNNY FROM THE HUDSON RIVER VALLEY EASTWARD INTO THE
EARLY TO MID PM...BEFORE THE CLOUD INCREASE AHEAD OF THE FIRST
FRONT. MAX TEMPS WILL STILL RUN ABOVE NORMAL WITH U30S TO L40S IN
THE VALLEYS...AND U20S TO M30S OVER THE MTNS. T/TD/RH/APPARENT
TEMP TRENDS WE REDONE BASED ON OBSERVATIONS. THE HIGHEST SNOW
ACCUMULATIONS WITH THIS DISTURBANCE LOOK LIKE THEY WILL BE NORTH
AND WEST OF OF THE CAPITAL REGION WITH 1 TO 4 INCHES POSSIBLE
/ESPECIALLY THE WRN DACKS AND WRN MOHAWK VALLEY/.
PREVIOUS NEAR TERM...
LAKE EFFECT BAND STILL PERSISTENT...AND SHOULD CONTINUE UNTIL WARM
ADVECTION BEGINS LATER THIS MORNING...WHEN THE BAND SHOULD BECOME
DISRUPTED. ALSO SOME ISOLATED SNOW SHOWERS AND FLURRIES STILL INTO
THE SCHOHARIE VALLEY. KEEPING THE SNOW IN THE FORECAST FOR THE
NEXT COUPLE OF HOURS IN THE SCHOHARIE VALLEY AND WESTERN MOHAWK
VALLEY...WHILE KEEPING THE NORTHERN HERKIMER AREA IN BETTER
CHANCES THROUGH THE MORNING. ONE REPORT OF JUST OVER A FOOT
WAS JUST RECEIVED...BUT KEEPING ADVISORY UP AS MOST AREAS SHOULD
SEE 7 INCHES OR LESS.
CLOUD COVER HIGHLY DEPENDENT ON LAKE EFFECT MOISTURE THIS MORNING
BUT THERE SHOULD BE LESS CLOUD COVER ONCE THE LAKE EFFECT BAND IS
DISRUPTED THIS AFTERNOON. SO...JUST SOME MINOR ADJUSTMENTS TO SKY
COVER AND TEMPERATURES THROUGH THIS MORNING.
PREV AFD BELOW...
LAKE EFFECT BAND STILL EXTENDING INTO THE WESTERN MOHAWK VALLEY AND
SOUTHERN ADIRONDACKS. IT IS A BIT CELLULAR AS THE DEPTH OF THE
MOISTURE AND INSTABILITY IS RELATIVELY DEEP...EVIDENT IN THE 00Z BUF
SOUNDING. THE BAND SHOULD CONTINUE TO BRING SNOW INTO THE AREA
THROUGH THE EXPIRATION OF THE WINTER WEATHER ADVISORY. SOME ISOLATED
REFLECTIVITIES ARE RESPECTABLE BUT BASED ON THERMAL PROFILES AND THE
RAPIDLY CHANGING CHARACTER OF THE BAND...SNOW RATIOS AND DURATION OF
HEAVIEST SNOW SEEMS TO SUGGEST SNOW SHOULD STAY WITHIN THE ADVISORY
RANGE. SNOWFALL AMOUNTS STILL LOOK TO BE UP TO 7 INCHES. SOME
ISOLATED SNOW SHOWER ACTIVITY ALSO EXTENDING INTO THE SCHOHARIE
VALLEY THROUGH THE EARLY MORNING HOURS BUT LIGHTER AND MORE
SCATTERED THAN THE SINGLE BAND TO THE NORTH.
WARM ADVECTION WILL BEGIN BY LATE MORNING...SO THE SINGLE BAND AND
THE SCATTERED ACTIVITY TO THE SOUTH IN THE SCHOHARIE VALLEY SHOULD
GET DISRUPTED AROUND OR SHORTLY AFTER SUNRISE. THERE SHOULD BE SOME
PERIODS OF SUN THROUGH AT LEAST THE MORNING...MAYBE INTO THE
AFTERNOON...ESPECIALLY IN EASTERN AREAS...DEPENDING ON HOW QUICKLY
THE NEXT SYSTEM APPROACHES FROM THE GREAT LAKES. BASED ON MIXING
POTENTIAL TODAY...HIGHS IN THE UPPER 30S TO MID 40S BEFORE CLOUD
COVER ARRIVES. HIGHS IN THE LOWER TO MID 30S IN THE SOUTHERN
ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS.
NEXT QUICK MOVING NORTHERN STREAM SYSTEM TRACKS THROUGH THE REGION
TONIGHT...WHICH LOOKS TO BE RELATIVELY MOISTURE STARVED...EXCEPT FOR
WHAT COULD BE PICKED UP OFF THE GREAT LAKES. STILL...MOSTLY CLOUDY
MUCH OF THE NIGHT...WITH THE MOST WIDESPREAD SNOW SHOWER ACTIVITY IN
THE WESTERN MOHAWK VALLEY AND SOUTHERN ADIRONDACKS. SCATTERED
ACTIVITY SHOULD MAKE IT INTO MOST OF THE REGION...WITH MORE ISOLATED
ACTIVITY IN THE MID HUDSON VALLEY..SOUTHERN BERKSHIRES AND NW CT.
THERE COULD BE 1 TO 3 INCHES OF SNOW IN THE NORTHERN AREAS WITH
LOCAL DUSTINGS POSSIBLE ACROSS THE REST OF THE REGION. SOME PARTIAL
CLEARING IS POSSIBLE TOWARD SUNRISE...BUT GUSTY WEST TO NORTHWEST
WINDS SHOULD BEGIN AS THE SYSTEM EXITS LATE TONIGHT. LOWS IN THE
20S...BUT A LITTLE HIGHER THAN GUIDANCE NUMBERS DUE TO THE WINDS AND
MIXING. SOME LOWS IN THE TEENS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
BACK DOOR CDFNT PUSHES SOUTH INTO FCA AS 500HPA SHORT WVS MOVE
EAST ACROSS NEW YORK NEW ENG. THIS WILL BRING A BRIEF PERIOD OF
COLD AIR AND REINVIGORATE LK EFFECT BAND INTO TUG HILL/W ADNDKS.
BY MON NT. LATE MONDAY INTO TUES EASTERN TROF DEPARTS...RIDGING
BUILDS FROM GRTLKS TO SE STATES AND A 500HPA SHORT WAVE EJECTS INTO
NORTHERN GREAT PLAINS. THIS SETS UP FRONTOGENESIS AS WMFNT ORGANIZES
DLH-BOS. MONDAY AND MONDAY NIGHTS CLOUDS BLOOM ALL ALONG AND AHEAD OF
IT...AND OVERRUNNING SNOW BREAKS OUT ACROSS THE GRTLKS.
MON NT INTO TUE MORNING THIS -SN SPREADS ACROSS NY/NEW ENG. THE
NAM/GFS/ECMWF ARE SIMILAR BUT NAM QPF IS DEFINITELY LIGHTER. THE
GEM HAS BULK OF PCPN N OF FCA. AS THE 500HPA FLOW TURNS SW THE
MODEL SUIT GENERALLY LIFTS TO WMFNT OUT OF THE FCA TUE
EVNG...LEAVING AREA IN WARM SECTOR WITH -SHRA THREAT TILL CDFNT
MOVES THROUGH WED. THEY ALL TAKE MAJOR CYCLONE WITH THIS SYSTEM
WELL NORTH INTO ONT/QB.
TEMPS ARE GENERALLY ABV NORMAL TO MUCH ABV DURING THIS PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE FAST MOVING PATTERN CONTINUES WITH A SHORT WV MOVING THROUGH
THUR TRIGGERING ISOLD TO SCT -SHSN...MORE NEAR THE LAKE. HIGH
PRESSURE RIDGES SOUTH TO END THE WEEK WITH DRY CONDS...THEN THE
MODELS TAKE THE BIG DIVERGE. THE GFS PRODUCES A SIGNIFICANT
COASTAL LOW...AS USUAL BASED ON THE PHASING OF SHORT WAVES THAT
ARE SCATTERED ALL OVER EAST ASIA. THE ECMWF TAKES THIS STORM...NOT
UP THE EAST COAST...BUT UP THE ST LAWRENCE VLY. THE MODEL SUITE
HAS BEEN ALL OVER WITH THIS SYSTEM FROM IN THE WEST ATLC. FOR NOW
CARRIED CHC OR SLIGHT CHC. THERE`S 6 DAYS TO THE MODELS TO DEBATE
WITH THEMSELVES HOW THE SHORT WVS WILL PHASE. TEMPS DURING THE EFO
WILL BEGIN ABV NORMALS THU AND END THE PERIOD NEAR NORMAL.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
JUST SOME SCATTERED CLOUDS ABOVE 3000 FEET THROUGH THE MORNING...
THEN MID AND HIGH CLOUDS MOVE IN AHEAD OF THE NEXT SYSTEM THIS
AFTERNOON. SOME SCATTERED SNOW SHOWER ACTIVITY IS POSSIBLE AT KGFL
AND KALB AFTER 00Z SO ACKNOWLEDGING VCSH THERE. MOST OF THE SNOW
SHOWER ACTIVITY SHOULD STAY NORTH OF THE KPOU AREA. THE SNOW
SHOWERS SHOULD EXIT AFTER MIDNIGHT.
LIGHT WEST TO SOUTHWEST WINDS WILL INCREASE TO 10 TO 15 MPH AROUND
MID MORNING. GUSTY SOUTHWEST TO WEST WINDS SHOULD CONTINUE
THROUGH EARLY AFTERNOON AT 10 TO 15 MPH...WITH GUSTS OVER 20 MPH.
WINDS WILL BECOME SOUTH TO SOUTHWEST THIS AFTERNOON AT 10 MPH OR
LESS. ONCE THE SNOW SHOWER ACTIVITY MOVES OUT TONIGHT...WINDS
SHOULD SHIFT TO WEST AND NORTHWEST AT 10 TO 15 MPH...AND COULD GET
GUSTY.
OUTLOOK...
SUN NIGHT...VFR/MVFR. CHC -SHSN.
MON-TUE...VFR. NO SIG WX.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA/-SHSN.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE. A CLIPPER LOW PRESSURE SYSTEM AND
TWO COLD FRONTS WILL IMPACT THE REGION THIS EVENING INTO MONDAY
MORNING. SOME SCATTERED SNOW SHOWERS AND FLURRIES WILL BE COMMON
WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW INCHES IN THE SOUTHERN
ADIRONDACKS. A WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY
NIGHT INTO TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK
ADN ANY RAINFALL THAT OCCURS WILL BE LIGHT AND MOST PRECIPITATION
DURING THE WEEK WILL BE LIGHT SNOW.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER/WASULA
NEAR TERM...NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...NAS
HYDROLOGY...NAS/WASULA
PREVIOUS FORECAST DISCUSSION IS BELOW...
AS OF 400 PM EST...THE WATER VAPOR LOOP THIS AFTERNOON CONTINUES
TO SHOW A SHORT-WAVE IN THE W/SW FLOW APPROACHING FROM THE GREAT
LAKES REGION AND LAKE ERIE. A FASTING MOVING SFC LOW OR A CLIPPER
ROTATING AROUND A CLOSED H500 CIRCULATION OVER HUDSONS BAY IS
MOVING ACROSS SE ONTARIO INTO SRN QUEBEC. THE COLD FRONT TO THE
CLIPPER HAS MOVED ACROSS OH AND MI AND IS MOVING INTO WRN NY AND
WRN PA. CLOUDS WILL CONTINUE TO THICKEN AND LOWER AHEAD OF THE
FRONT. THERE IS A BAND OF SNOW SHOWERS MOVING INTO THE TUG HILL
PLATEAU REGION...THAT WILL MOVE INTO THE WRN DACKS OVER THE NEXT
FEW HOURS. THE BEST LOW-LEVEL CONVERGENCE IS ALONG THE FRONTAL
BOUNDARY...AND MAINLY NORTH OF THE MOHAWK RIVER VALLEY. MOISTURE
WILL BE TAPPED FROM THE ERN GREAT LAKES WITH THE BEST MOISTURE
CONVERGENCE NORTHWEST OF THE CAPITAL REGION ALONG THE NOSE OF A
50-60 KT H850 LLJ. THE LATEST HRRR 3KM COLUMNAR MAX REF CONTINUES
TO SHOW A BROKEN BAND OF CELLS WITH SOME 30-40 DBZ ECHOES MOVE
ACROSS THE FCST AREA AHEAD OF THE FRONT BTWN 00Z-02Z. THERE COULD
BE SOME ISOLD SNOW SQUALLS THAT PUT OUT A BRIEF BURST OF SNOW.
WE KEPT THE HIGHEST POPS TO THE NORTH AND WEST OF THE CAPITAL
REGION...AND SLIGHT CHC TO LOW CHC FURTHER SOUTH AND EAST.
THE WINDS INCREASE IN THE WAKE OF THE FRONT FROM THE W/NW AT 15 TO
25 MPH WITH A FEW GUSTS IN THE 30-40 MPH RANGE...AND THE LAKE EFFECT
POTENTIAL INCREASES FOR THE WRN DACKS. THE NAM AND CAN REGIONAL
CONTINUE TO PRODUCE A QUARTER TO FOUR TENTHS OF AN INCH OF QPF WITH
A FAVORABLE 260 DEGREE LAKE TRAJECTORY IN THIS AREA. THE SFC-H850
WINDS ALIGN WELL FROM THE WEST WITH LITTLE DIRECTIONAL SHEAR. THE
INVERSION IS WELL ABOVE 10KFT AGL BASED ON NAM SOUNDING PROFILES
OVER NRN HERKIMER COUNTY...AND THEN SLOWLY LOWER TO ABOUT 7-8 KFT
AGL AROUND 12Z- 15Z. THE INSTABILITY CLASS OFF THE BUFKIT PROFILES
CONTINUES TO BE CONDITIONAL WITH MARGINAL DELTA T/S. WE PUT OUT A
LAKE EFFECT ADVISORY FOR NRN HERKIMER CTY FROM 00Z/SUN TO 15/SUN FOR
NRN HERKIMER CTY. THE LOCATIONS IMPACTED WILL GENERALLY BE FROM THE
RT 28/OLD FORGE CORRIDOR NORTHWARD WITH 3 TO 7 INCHES OF
ACCUMULATION. THERE COULD ALSO BE SOME BLOWING SNOW TONIGHT. FURTHER
EAST INTO HAMILTON COUNTY EXPECT 2 TO 5 INCHES OF SNOWFALL WITH THE
BAND EXTENSION IN QUESTION. ELSEWHERE FROM THE SCT SNOW SHOWERS AND
ISOLD SQUALLS...A COATING TO HALF AN INCH WILL BE POSSIBLE. COLD
ADVECTION OCCURS OVERNIGHT WITH H850 TEMPS FALLING BACK TO -8C TO
-12C. EXPECT LOWS TO BE A LITTLE COLDER TONIGHT THAN LAST NIGHT WITH
LOWS IN THE MID AND U20S IN THE VALLEYS...AND UPPER TEENS AND LOWER
20S OVER THE MTNS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
TOMORROW...THE LAKE EFFECT BEGINS TO DIMINISH WITH THE LOWERING
INVERSION...AND THE LOW LEVEL FLOW BACKING TO THE SOUTH/SOUTHWEST
AHEAD OF THE NEXT DISTURBANCE APPROACHING FROM THE LOWER GREAT
LAKES REGION. HIGH PRESSURE WILL BRIEFLY RIDGE IN FROM THE SOUTH.
THE SHORT-WAVE IS A BIT STRONGER THAN THE ONE TONIGHT. THE STRONG
CYCLONIC VORTICITY ADVECTION COUPLED WITH STEEP LAPSE RATES MAY
FOCUS A ROBUST BAND OF SNOW SHOWERS APPROACHING FROM W-CNTRL NY
LATE IN THE AFTERNOON. WE INCREASED THE POPS PREDOMINANTLY WEST OF
THE HUDSON VALLEY IN THE MID TO LATE AFTERNOON WITH SLIGHT CHC TO
CHC VALUES...EXCEPT LIKELY AND CATEGORICAL VALUES OVER THE WRN
MOHAWK VALLEY...AND SRN DACKS. WE WENT CLOSE TO GFSMOS MAX TEMPS
WITH HIGHS IN THE U30S TO L40S IN THE VALLEYS /A FEW M40S IN THE
MID HUDSON VALLEY/...AND U20S TO M30S OVER THE MTNS.
TOMORROW NIGHT...THE POTENT VORT MAX AND ITS ASSOCIATED COLD FRONT
TIED TO THE TROUGH OF LOW PRESSURE/CLIPPER MOVING ACROSS SE QUEBEC
WILL MOVE ACROSS THE REGION BTWN 00Z-06Z. THE STRONG CONVERGENCE
ALONG THE BOUNDARY MAY PRODUCE MORE WIDESPREAD ONE INCH AMOUNTS
WITH THIS SYSTEM. THE WRN DACKS COULD GET ANOTHER 1 TO 4
INCHES...AS LAKE EFFECT STARTS AGAIN. LOWS WILL GENERALLY BE IN
THE TEENS OVER THE HILLS AND MTNS...AND L20S IN THE VALLEYS...AS
STRONG COLD ADVECTION SWEEPS OVER THE REGION.
MONDAY...ANOTHER BRIEF LAKE CONNECTION IS EXPECTED MONDAY MORNING.
THIS TIME A 290 DEGREE LOW-LEVEL TRAJECTORY WOULD BE FAVORED WITH
THE SW DACKS...W-CNTRL MOHAWK VALLEY...AND NRN CATSKILLS IMPACTED.
WE COULD SEE A BAND SNEAK DOWN THE MOHAWK RIVER VALLEY EARLY IN
THE DAY...AND WE KEPT SOME SLIGHT-LOW CHC POPS IN FOR THE CAPITAL
REGION...TACONICS...AND BERKSHIRES. RIGHT NOW...SNOW ACCUMULATIONS
WEST OF ALBANY WOULD BE IN THE 1 TO 3 INCH RANGE. THE NAM
CONTINUES TO SHOW THE LAKE EFFECT POTENTIAL WEAKENING DURING THE
DAY WITH THE FLOW BEGINNING TO BACK AGAIN...AND THE INVERSION
LOWERING...AS HIGH PRESSURE BRIEFLY BUILDS IN AGAIN. H850 TEMPS
TUMBLE CLOSER TO SEASONABLE LEVELS AT -13C TO -16C OVER THE REGION
WITH HIGHS IN THE U20S TO M30S IN THE VALLEYS AND LOWER
ELEVATIONS...AND LOWER TO M20S OVER THE MTNS.
MONDAY NIGHT...A WARM FRONT WILL MOVE INTO THE REGION FROM THE
OHIO VALLEY AND THE LOWER GREAT LAKES REGION. THE ISENTROPIC LIFT
INCREASES ON THE 295K SFC. OVERRUNNING LIGHT SNOWFALL WILL
OVERSPREAD THE REGION. THE BETTER QG LIFT IS FROM THE HUDSON
VALLEY WESTWARD. WE KEPT HIGH CHC POPS IN THE FORECAST FOR THIS
TIME FRAME. THE WARM FRONT SLOWLY LIFT NORTHWARD OF THE I-90
CORRIDOR BY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AT THE START OF THE EXTENDED PERIOD...A WARM FRONT WILL BE MOVING
NORTH THROUGH THE REGION DURING TUESDAY MORNING. THIS WILL CONTINUE
TO BRING SOME LIGHT SNOW FOR AREAS MAINLY TO THE NORTH OF I-90. BY
AFTERNOON...MUCH OF THE PRECIPITATION SHOULD BE DONE ACROSS THE
REGION....WITH THE EXCEPTION ACROSS PARTS OF THE SOUTHERN
ADIRONDACKS/LAKE GEORGE AREA.
BEHIND THIS WARM FRONT...A WARMER SOUTHERLY FLOW WILL TAKE OVER.
THIS WILL ALLOW FOR TUESDAY NIGHT MIN TEMPS NOT TO BE AS COOL AS
RECENT NIGHTS...WITH MUCH OF THE CAPITAL REGION REMAINING ABOVE
FREEZING EVEN DURING THE OVERNIGHT. TEMPS WILL CONTINUE TO BE ABOVE
NORMAL RIGHT INTO WEDNESDAY...WITH 40S ACROSS THE ENTIRE AREA BY WED
AFTN. SOME RAIN SHOWERS WILL BE POSSIBLE...ESP FOR WEDNESDAY...AS A
STORM SYSTEM MOVES ACROSS SOUTHERN CANADA AND THE STORM/S COLD FRONT
PROVIDES SOME LIFT FOR SHOWERS ACROSS OUR AREA.
THE MODELS DISAGREE ON WHAT OCCURS FOR WEDNESDAY NIGHT AND BEYOND.
THE 12 UTC ECMWF ATTEMPTS TO DEVELOP A WAVE ALONG THE FRONTAL
BOUNDARY AS IT MOVES OFF THE EASTERN SEABOARD...WHICH COULD BRING
SOME ADDITIONAL LIGHT PRECIP /RAIN OR SNOW/ TO SOUTHEASTERN PARTS OF
THE AREA FOR WED NIGHT INTO THURSDAY. MEANWHILE...THE GFS IS MUCH
MORE PROGRESSIVE AND KEEPS IT FAIRLY DRY WITH JUST SOME CYCLONIC
FLOW RAIN/SNOW SHOWER FOR NORTHWESTERN PARTS OF THE AREA. THE GFS
HAS BEEN PERSISTENT IN GOING AGAINST THE IDEA OF A BIG STORM DURING
THIS PERIOD...AND THE 12 UTC GEFS ONLY SUPPORTS LIGHT PRECIP FROM
WRAP AROUND OF THE CANADIAN LOW PRESSURE DURING THIS TIME FRAME AS
WELL. EVEN THE ECMWF IS STARTING TO BACK OFF ON THE IDEA OF A
STRONGER SECONDARY WAVE DURING THIS PERIOD...AS IT ONLY HAS A WEAK
LOW ALONG THE FRONT...WITH THE STORM WAITING UNTIL ITS MUCH FURTHER
OFFSHORE BEFORE RAPID DEEPENING. FOR NOW...WITH GO WITH LOW POPS
FOR WED NIGHT/THURS AND CONTINUE TO SHOW TEMPS ABOVE NORMAL.
TEMPS WILL CONTINUE TO BE SOMEWHAT ABOVE NORMAL FOR FRIDAY INTO
SATURDAY ACROSS THE AREA. FOR NOW...WILL GO WITH SLIGHT CHC POPS AS
SOME WEAK UPPER LEVEL DISTURBANCES MAY ALLOW FOR A RAIN OR SNOW
SHOWER...ESP FOR THE HIGHER TERRAIN...BEFORE A STRONG AREA OF HIGH
PRESSURE MOVES TOWARDS THE AREA FOR LATER IN THE WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITONS EXPECTED THROUGH THE PERIOD WITH SOME BRIEF VFR
CEILINGS...SO GOING PREDOMINANT SCATTERED CLOUDS. SOME FLURRIES
ARE POSSIBLE AROUND KGFL AND KALB THROUGH ABOUT 11Z...BUT TOO
ISOLATED AND LIGHT TO ACKNOWLEDGE IN TAF. SOME SCATTERED SNOW
SHOWERS ARE POSSIBLE THIS EVENING...BUT AGAIN...TOO SCATTERED
TO MENTION IN TAFS YET.
GUSTY WEST WINDS WILL CONTINUE THROUGH EARLY AFTERNOON AT 10 TO 15
MPH...WITH GUSTS OVER 20 MPH. WINDS WILL BECOME SOUTH TO
SOUTHWEST THIS AFTERNOON AT 10 MPH OR LESS.
OUTLOOK...
SUN NIGHT...VFR/MVFR. CHC -SHSN.
MON-TUE...VFR. NO SIG WX.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA/-SHSN.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE FROM THE RAIN AND MIXED
PRECIPITATION YESTERDAY. THE FLOOD WARNING WAS CANCELED FOR
MCKEEVER ON THE MOOSE RIVER...AS THE ICE JAM HAS BROKEN...AND WATER
IS FREELY FLOWING AGAIN.
A COUPLE OF CLIPPER LOW PRESSURE SYSTEMS AND THEIR ASSOCIATED COLD
FRONTS WILL IMPACT THE REGION LATE TODAY AND TONIGHT...AND SUNDAY
NIGHT INTO MONDAY MORNING. SOME SCATTERED SNOW SHOWERS AND
FLURRIES WILL BE COMMON WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW
INCHES IN THE SOUTHERN ADIRONDACKS. SOME MODERATE SNOW
ACCUMULATIONS WILL BE POSSIBLE TONIGHT IN THE WESTERN ADIRONDACKS. A
WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY NIGHT INTO
TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ032.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...NAS
NEAR TERM...NAS
AVIATION...NAS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
645 AM EST SUN JAN 29 2012
.AVIATION /12 UTC TAFS/...
CONT VERY SIMILAR WRT RAPIDLY DETERIORATION OF MET CONDS LTR THIS AM
WITH ARRIVAL OF UPSTREAM WAVE. SLIGHT MOD TO LTR TIMING WITH REGARD
TO LWST CONDS...THOUGH STILL BRIEF MENTION AT LIFR CONDS AT KSBN AND
IFR AT KFWA APPEARS BEST PER UPSTREAM TRENDS AND LATEST AVBL HRRR
AND RUC TRENDS. ANTICIPATE HIGH VARIABILITY IN OVERALL CONDS BEFORE
SETLLING BACK ABOVE FUEL ALT BY ERLY AFTN.
&&
.SHORT TERM...
YET ANOTHER DIFFICULT FCST WRT SHORT TERM...ESP FIRST PD WITH
ATYPICAL CLIPPER SYSTEM WITH LOWER THAN AVG CONFIDENCE AND BUST
POTNL/HIGH RANGE OF REASONABLE EXPECTATIONS ATTM. DISTINCTLY
CRIMPED SHORTWAVE/TROPOSPHERIC FOLD NEAR KALO ATTM PER NAM/WV
IMAGERY DIGGING THROUGH BASE OF PRIMARY HUDSON/JAMES BAY VORTEX
WITH ASSOCD EXTENSION TO ARCTIC/JUST NORTH OF 70N PARALLEL/VCNTY
BARROW. STRONG 8H-5H COLD POOL POISED NORTH OF IA VORTICY TO
PLUNGE SEWD INTO SRN LAKE MICHIGAN AROUND 15 UTC. CURRENT
HORIZONTAL ROLLS AIDED BY LEADING E-W BURST OF MIDLVL FGEN LARGELY
SHOULD RMN NORTH OF CWA IN PREFRONTAL WRLY FLOW ACRS SRN LK MI AND
WHERE GRTR LK/8H THERMAL INSTABILITY AND MSTR DEPTH RESIDE.
CONTINGENCIES ALSO INCLUDE HEDGED BETS TOWARD BREVITY IN SYNOPTIC
SCALE CONVECTIVE BURSTS ALONG AND IMMEDIATELY POST CLIPPER INTO
NWRN CWA AROUND 12 UTC. SFC REFECTION CONTS TO GARNER STRENGTH PER
INCRG FALL/RISE PRES COUPLET NRN IL/SRN MN ALREADY TO 5MB/3 HR
CHNG. DOWNSTREAM 0-0.5KM THETA-E STREAM FM ECNTL MO INTO WRN
CWA SHOULD HELP TO PRECONDITION/MAINTAIN MFLUX GAINS AS IT MOVES
ACRS SRN LK MI. BEST STACKED UVM/MSTR DEPTH/THERMAL INSTABILITY
ACRS FAR NWRN/NRN CWA. SATURATED DEPTH WANES WITH SRN/SERN CWA
EXTENT AS WELL AS COLLOCATION OF MIDLVL ASCENT PER INCRSG SLANTED
UPDRAFTS. ALSO BEST INTERLACE OF FINER RANGE MODEL SIGNALS OF
MIDLVL FGEN/DPVA/STRONGEST DEFORMATION BAND ACRS NRN/NWRN
CWA...OPTED FOR POTNL FOR BRIEFLY HEAVY SHSN MENTION MID-LATE AM
AS WELL. TEMPORAL PERSISTENCE SHOULD LIMIT ACCUMS TO 2-3 INCH AMOUNTS
ACRS NWRN/NRN AREAS AND SIMILARLY DCRSG TO LESS THAN AN INCH FAR
SRN CWA OWING LARGELY TO LESS DVLPD MSTR PROFILE. THOUGH FAR
NRN/NWRN CWA COULD SEE MORE SHOULD CBL VEER TOO GREAT POST
CLIPPER THIS AFTN AS HAVE HIGH RELIANCE ON DRIER/SINGLE DIGIT SFC
DPS POOLED INTO WRN WI ALREADY AS TO NEGATE SUSTAINABILITY OF AFTN
LES. WL ALLOW DAY SHIFT TIME TO ASSESS AFTN POTNL THAT WOULD PSBLY
NECESSITATE ADVISORY LEVEL AMOUNTS IN THIS REGN. LAKE INDUCED EQL
CRASH TOWARD EVENING AND TRANSITION TO SLGHT CHC EVE ACRS MI
COUNTIES.
LEE ROCKIES/PLAINS FOEHN TO ESTABLISH SHARP WARM FNTL BNDRY PUSHING
ENEWD OUT OF CNTL PLAINS SUNDAY NIGHT AND INTO WRN GRTLKS MONDAY.
SOME CONCERN WITH SATURATED MIDLVLS/THERMAL PROFILE AMID ELEVATED
WARM LYR ASCENDING COLD BLYR FOR MIX SLEET/SNOW ACRS FAR NRN/NERN
CWA WITH SIG I285-290K ASCENT. HAVE SLIGHT ADJUSTMENT TO WX WITH
ONLY LOW CHC POPS MON. ALSO CONCERN WITH SNOWMELT/SATURATION OF
BLYR FOR STRATUS/DRIZZLE/FOG POTNL MON NIGHT...HOWEVER NO
CONFIDENCE FOR MORE THAN CLOUD COVER INCRS WITH A FAINT INDIRECT
NOD TOWARD PSBLTY.
&&
.LONG TERM...
TUESDAY THROUGH SATURDAY
PERSISTENT DEEP UPPER TROUGH OVER THE NORTHERN PAC INTO NE
RUSSIA...WILL CONTINUE TO SUPPORT FAST NW FLOW THROUGH MUCH OF THE
EXTENDED PERIOD...WITH MILD PAC DOWNSLOPE FLOW. INHERENT DIFFICULTY
IN RESOLVING THIS TYPE OF FLOW PATTERN IN THE LONG TERM PERIOD WILL
CONTINUE TO SUPPORT A STRONG SIDE TOWARD FORECAST
CONSISTENCY/PERSISTENCE PER POPS/TEMPS. THIS IS ESPECIALLY TRUE
GIVEN POORLY ANALYZED TURBULENT NORTHERN STREAM FLOW WITH ROCKIES
INTERACTION. JET CORES/ASSOCIATED SUBTLE WAVES/AND CAA PROCESSES ARE
FAR FROM BEING RESOLVED...AND ATTM WILL SIDE HEAVY TOWARD FORECAST
PERSISTENCE...WHICH INCLUDES A WX MENTION FOR THE THE TWO IMPULSES
EXPECTED TO ADVECT THROUGH THE FLOW. THE ECMWF REMAINS THE MODEL OF
CHOICE. HOWEVER...IT/S SOLUTIONS CONTINUE TO EXHIBIT TRACK/STRENGTH
DIFFERENCES PER THE THUR PERIOD AS THE 00Z RUN HAS RE-INTRODUCED A
POTENT SW EJECTING UPPER TROUGH. THE PRIMARY IMPETUS FOR SUCH A
RADICAL SHIFT IN RUN-RUN SOLUTIONS IS THE JUXTAPOSITION OF A LONG
LATITUDINAL JET CORE...WITH THE NOSE OF THIS JET INTERACTING WITH
THE ROCKIES. EXPECT CONTINUED FLOW ADJUSTMENT WITH POP ADJUSTMENT.
FORECAST MODELS ARE BEGINNING TO TREND TOWARD POSITIVE HEIGHT
ANOMALIES OVER GREENLAND BY NEXT WEEKEND...A SOLUTION THAT WOULD
SUPPORT NEGATIVE AO INDICES WITH A STAUNCH CP/MODIFIED ARCTIC
AIRMASS INTRUSION POSSIBLE BEHIND THE FRI-SAT TROUGH PASSAGE.
TUE-THUR...WARM/MILD CONDITIONS WITH PASSING IMPULSES EXPECTED TO
SUPPORT PRECIP AT TIMES. BEST CHANCE FOR PRECIP LOOKS TO BE IN
THE TUE NIGHT PERIOD GIVEN CONTINUED PROGGED SUFFICIENT LL MOISTURE
AHEAD OF THE EXPECTED UPPER IMPULSE. DRY CONDITIONS STILL FAVORED
WED...GIVEN WIDESPREAD MODEL SUPPORT FOR WEAK SFC RIDGING. THUR
STILL REMAINS QUESTIONABLE GIVEN A POTENTIAL EJECTING SW CONUS UPPER
TROUGH. WILL NOT THROW OUT THE 00Z ECMWF...WHICH REMAINS A STRONG
OUTLIER. COMPLICATED FLOW WARRANTS STRONG CONSIDERATION OF THE
ECMWF...IN ADDITION TO THE FACT THE ECWMF CONTINUES TO HIGHLY OUT
PERFORM ALL OTHER LONG RANGE FORECAST MODELS. HENCE...LEFT PREVIOUS
FORECAST NUMBERS WHICH COVER THESE CONCERNS. AGAIN...MILD CONDITIONS
EXPECTED AS TEMPS WILL EXCEED 50 IN THE PERIOD MANY PLACES...ESP IF
ENOUGH INSOLATION IS ATTAINED. HAVE CONTINUED ABOVE NORMAL TEMPS.
FRI-SAT...SIGNALS FOR SIG FLOW ADJUSTMENT SUPPORTS A DOWNTREND IN
TEMPS BY THE WEEKEND BACK TO CLIMO...WITH SIGNIFICANTLY COOLER
NUMBERS POSSIBLE BY SUN IF SUBSTANTIAL GREENLAND RIDGING DEVELOPS.
OTHERWISE...RETAINED LOW CHANCE SNOW MENTION SAT GIVEN A LIKELY FLOW
ADJUSTING IMPULSE/CP FRONT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR LMZ043-046.
&&
$$
SHORT TERM...MURPHY
LONG TERM...JC
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
734 AM CST SUN JAN 29 2012
.UPDATE...
RADAR RETURNS SHOW THE BULK OF THE SNOW IS NOW EAST OF THE CWFA
WITH ONLY LINGERING FLURRIES REMAINING. RUC TRENDS AGREE WITH
WATER VAPOR IN PLACING THE MAIN VORT MAX OVER NORTHEAST ILLINOIS.
A SECONDARY VORT WAS APPROACHING THE MISSISSIPPI RIVER PER THE RUC
WITH A VORT LOBE INTO NORTHEAST IOWA. THE VORT LOBE IS HELPING TO
MAINTAIN FLURRIES AND THE AXIS OF THIS LOBE WILL BE EAST OF THE
MISSISSIPPI BY MID MORNING. AT THIS TIME STRONG DOWNWARD MOTION
WILL BE ACROSS THE CWFA WHICH WILL END THE PRECIPITATION THREAT.
AN UPDATE TO THE FCST TO REFLECT THE CURRENT TRENDS HAS BEEN SENT.
..08..
&&
.PREV DISCUSSION... /ISSUED 533 AM CST SUN JAN 29 2012/
AVIATION...
OVERALL RADAR TRENDS INDICATE THE BULK OF THE -SN IS GENERALLY
DONE. SOME FLURRIES WILL BE POSSIBLE THROUGH 15Z/29 AT KDBQ WITH
MVFR CONDITIONS. OTHERWISE...VFR CONDITIONS WILL BE SEEN AT
KCID/KMLI/KBRL WITH VFR DVLPG THROUGH 18Z/29 AT KDBQ. AFT 03Z/30
STRONG SOUTHWEST FLOW ALOFT WILL BRING MID AND HIGH LEVEL CLOUDS
INTO EASTERN IOWA AND NORTHERN ILLINOIS BUT VFR CONDITIONS ARE
EXPECTED AT ALL TAF SITES.
.08..
PREV DISCUSSION... /ISSUED 339 AM CST SUN JAN 29 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A WEAK INFERRED LOW WEST OF KONA WITH A WARM
FRONT EAST INTO CENTRAL WISCONSIN. A COLD FRONT EXTENDS WEST FROM
THE LOW INTO NORTHEAST SOUTH DAKOTA. A TROF RAN SOUTH FROM THE LOW
TO KFNB. DEW POINTS WERE GENERALLY IN THE TEENS AND 20S ACROSS THE
MIDWEST WITH SINGLE DIGITS IN PARTS OF THE UPPER MIDWEST AND
PLAINS. RADAR SHOWS -SN MOVING EAST SOUTH FROM MINNESOTA INTO
SOUTHERN WISCONSIN WITH PATCHY SNOW ACROSS PARTS OF IOWA.
SHORT TERM...TODAY AND TONIGHT...
RUC TRENDS HAVE BEEN VERY USEFUL IN DEPICTING THE IMMEDIATE SHORT
TERM.
THE BULK OF THE SNOW ASSOCIATED WITH THE CLIPPER SYSTEM IS FALLING
GENERALLY ALONG AND NORTH OF THE VORT MAX TRACK WHICH FITS
CONCEPTUALLY WHERE THE STRONGEST FORCING WOULD BE LOCATED. THE
VORT MAX WILL MOVE EAST SOUTHEAST INTO NORTHERN ILLINOIS AND
SHOULD BE OVER NORTHEAST ILLINOIS AT SUNRISE. THUS THE BEST SNOW
WILL BE JUST OUTSIDE OF THE CWFA BUT A TRAILING VORT LOBE WITH LOW
850-700MB CONDENSATION PRESSURE DEFICITS AND RESPECTABLE FORCING
SHOULD ALLOW SOME -SN TO MOVE INTO THE HWY 20 CORRIDOR...
ESPECIALLY ALONG AND EAST OF DUBUQUE. F VECTOR CONVERGENCE AND
SOMEWHAT LOW CONDENSATION PRESSURE DEFICITS WITH SOME FORCING
SHOULD ALLOW -SN TO BE SEEN DOWN TO HWY 30 WITH FLURRIES IN THE
I-80 CORRIDOR. BASED ON OVERALL TIMING FROM RADAR...A MAJORITY OF
THE -SN AND FLURRIES SHOULD BE DONE BETWEEN 8 AND 9 AM THIS
MORNING.
FROM MID MORNING THROUGH NOON SOME LINGERING FLURRIES MAY BE
POSSIBLE IN THE FAR EASTERN PARTS OF THE CWFA AS FORCING WEAKENS
AND CONDENSATION PRESSURE DEFICITS RISE.
CLEARING SKIES AND DRY CONDITIONS WILL BE SEEN THIS AFTERNOON.
WHAT WAS THOUGHT TO BE A DRY SUNDAY NIGHT HAS SEVERAL SIGNALS
SUGGESTING THAT MAY NOT BE THE CASE.
THE EARLY EVENING HOURS WILL BE DRY AS THE SFC RIDGE IS OVER THE
CWFA AND MOVES EAST OF THE AREA. TEMPERATURES SHOULD DROP QUICKLY
AFTER SUNSET BEFORE LEVELING OUT AND THEN STARTING A SLOW RISE.
STARTING AROUND MID EVENING STRONG WAA ALOFT BEGINS MOVING INTO
THE WESTERN CWFA WITH AN APPROACHING TROF/FRONT. THE STRENGTH OF
THE WAA COMBINED WITH LOWERING 850-700MB CONDENSATION PRESSURE
DEFICITS SUGGESTS THE POTENTIAL FOR PRECIPITATION. INDEED LOOKING
AT THE HEAVY RAIN AND LIFT TOOLS SHOWS RESPECTABLE SPEED AND
MOISTURE CONVERGENCE AROUND 850MB. MODEL FCST SOUNDINGS SHOW THE
MID LEVELS SATURATING TO VARYING AMOUNTS.
TAKING ALL THIS INTO CONSIDERATION AND NOTING THAT THE ATMOSPHERE
REMAINS FAIRLY DRY BELOW 850MB SUGGESTS THAT FLURRIES MAY BE
POSSIBLE STARTING AROUND MID EVENING WEST OF THE MISSISSIPPI AND
NORTH OF HWY 30 WITH THE ACTIVITY SPREADING EAST OF THE MISSISSIPPI
AND NORTH OF HWY 30 AFTER MIDNIGHT. FCST SOUNDINGS VERY LATE
TONIGHT DEVELOP A PRONOUNCED WARM LAYER ALOFT WHILE LOW LEVEL TEMPERATURES
REMAIN BELOW FREEZING. IF THE LOW LEVELS WERE CLOSE TO SATURATION
THIS WOULD BE A CLASSIC FREEZING RAIN PROFILE. HOWEVER...THE LOW
LEVELS REMAIN DRY OR DRY OUT EVEN FURTHER. THUS WILL KEEP ONLY A
MENTION OF FLURRIES GOING AFTER MIDNIGHT AS ANY PRECIPITATION
FALLING MAY HAVE TROUBLE REACHING THE SFC AND WOULD RESULT IN
EVAPORATIVE COOLING AS WELL.
08..
LONG TERM...MONDAY THROUGH NEXT SATURDAY...
SEMI-ZONAL FLOW WITH MUCH ABOVE NORMAL TEMPS TO TRANSITION TO NORTHWEST
FLOW LATE WEEK WITH COLDER TEMPS INTO NEXT WEEKEND.
MON... TEMPS WILL BE WELL ABOVE NORMAL. WARM FRONTAL PASSAGE EXPECTED
EARLY AM ACCOMPANIED BY CLOUDS WITH FLURRIES POSSIBLE NORTH... THEN
DECREASING CLOUDS AND GUSTY SW WINDS BY PM TO FUEL WARM-UP. 00Z NAM
IS CONSIDERABLY WARMER AT 925 MB (OVER 2 STANDARD DEVIATIONS ABOVE
NORMAL) ESPECIALLY ACROSS THE SOUTH WHERE IT SHOWS TEMPS AROUND 14C
BY 21Z. MEANWHILE... GFS AND ECMWF SHOW 925 MB TEMPS ONLY AROUND 8-9C
ACROSS SOUTH. NAM WOULD EASILY SUPPORT UPPER 50S TO MID 60S SOUTH
AND AROUND 50F NORTH ONLY MIXING TO 925 MB AND WOULD PUT RECORD HIGHS
IN SERIOUS JEOPARDY... ESPECIALLY OVER SOUTHEAST IA... WEST CENTRAL IL
AND NORTHEAST MO. GIVEN TIME OF YEAR AND LIKELIHOOD OF CONSIDERABLE
MID CLOUDINESS FOR A WHILE MON AM WITH STRONG MID LEVEL THETA-E ADVECTION
HAVE OPTED TOWARD MORE CONSERVATIVE GFS AND ECMWF... ESPECIALLY OVER THE
SNOW PACK NORTH OF HWY 30. REASONABLE AGREEMENT NOW EXISTS WITH
DETERMINISTIC MODELS AND ENSEMBLES MOVING A PROGRESSIVE SHORTWAVE
THROUGH NORTHERN PLAINS AND UPPER MIDWEST ON TUE. ATTENDANT FRONT
OR MORE LIKELY JUST A WIND SHIFT WILL PUSH THROUGH WESTERN AND TOWARD
CENTRAL IA LATE MON NGT. CWA WILL RESIDE IN WARM SECTOR WITH
S/SW WINDS AND INCREASING HIGH CLOUDINESS WITH POSSIBLY LOWER CLOUDS
ARRIVING LATE TO KEEP LOWS ON MILD SIDE AND ABOVE WARM SIDE OF GUIDANCE.
TUE... MODELS WHICH HAD BEEN CONSISTENT WITH LOW MEASURABLE QPF SIGNAL
ARE NOW OVERALL TRENDING DRIER INCLUDING SREF WHICH NOW SHOWS
PROBABILITY OF MEASURABLE PCPN AT OR BELOW 15 PERCENT AND ONLY FAR S/E.
THIS LIKELY DUE TO LOW LEVEL FLOW VEERING AHEAD OF FRONT OR WIND SHIFT
THEREBY REDUCING LOW LEVEL CONVERGENCE. WILL THEREFORE KEEP POPS ONLY AT
SLIGHT CHC ALL BUT FAR N/W FOR LIGHT RAIN WITH NAM...GFS AND ECMWF
SOUNDINGS ACTUALLY MORE SUPPORTIVE OF DRIZZLE WITH CONTINUED LOW LEVEL
MOISTURE ADVECTION. HIGHS TUE STILL WELL ABOVE NORMAL AS WEAK FRONT
OR WIND SHIFT GRADUALLY PASSES INTO TUE NGT. DESPITE CLOUDY SKIES ON TUE
HIGHS SHOULD STILL BE IN THE 50S SOUTHEAST 1/2 OR SO DUE TO MOISTURE
ADVECTION.
WED-SAT... FCST CONFIDENCE EXTREMELY LOW HEADING INTO LATE WEEK AND NEXT
WEEKEND. OVERALL PATTERN LOOKS TO BECOME HIGHLY AMPLIFIED BY THU-FRI
WITH RIDGING DEVELOPING OVER WESTERN NOAM. IN RESPONSE AN
AMPLIFYING DEEP TROUGH LIKELY OVER CENTRAL AND EVENTUALLY EASTERN CONUS.
ENSEMBLE SPREADS REMAIN QUITE LARGE DURING THIS TRANSITION PERIOD AND
DETERMINISTIC MEDIUM RANGE MODELS SHOWING VERY POOR RUN TO RUN CONTINUITY
AND LARGE VARIABILITY FROM MODEL TO MODEL ALL MAKING FOR EXTREMELY LOW
CONFIDENCE ON FCST DETAILS. MAIN CULPRIT FOR MODEL UNCERTAINTY LIES WITH
EVOLUTION OF SHORTWAVE ENERGY IN EVOLVING DEEP TROUGH. BOTTOM LINE... THE
GENERAL IDEA OF TRANSITION TO HIGHLY AMPLIFIED PATTERN BY NEXT WEEKEND
WITH SHARP WESTERN NOAM RIDGE LOOKS GOOD... BUT THE DEVIL LIES WITH THE
DETAILS AND HANDLING OF DOWNSTREAM SHORTWAVE ENERGY PACKETS. IT DOES SEEM
THAT THE MODELS WANT TO DEVELOP A CLOSED UPPER LOW AND CONCEPTUALLY FITS
WITH MAGNITUDE OF JET ENERGY AND BAROCLINICITY. ON SIDE NOTE... BRUTAL
COLD CONTINUES OVER AK WITH FAIRBANKS HAVING HIT -50F YSTDY FOR FIRST TIME
SINCE 2006. TYPICALLY BITTER COLD IN AK PORTENDS COLD COMING TO THE
LOWER 48... AND RECENT LOWERING TRENDS OF NAO/AO FROM DETERMINISTIC MODEL
RUNS OF GFS AND ECMWF WOULD CORROBORATE IDEA OF TURNING COLDER IN FEB
AFTER AN ABOVE NORMAL START. ..05..
CLIMATE...
RECORD HIGHS FOR JANUARY 30...
MOLINE.........59 IN 1988
CEDAR RAPIDS...55 IN 1988
DUBUQUE........52 IN 1890
BURLINGTON.....60 IN 1988
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
541 PM CST MON JAN 30 2012
...UPDATE TO AVIATION...
.DISCUSSION...
21Z WATER VAPOR IMAGERY SHOWS A SHORTWAVE MOVING ACROSS MT AND ID
AND INTO THE NORTHERN PLAINS. MEANWHILE SURFACE OBS SHOW A BROAD
TROUGH OF LOW PRESSURE FROM THE SOUTHERN HIGH PLAINS INTO THE
NORTHERN PLAINS. THIS HAS ALLOWED FOR HIGHS TO WARM INTO THE MID
AND UPPER 60S WHILE DEWPOINTS INCREASED INTO THE 30S ACROSS THE
FORECAST AREA.
FOR TONIGHT AND TUESDAY...THE MAIN CONCERN IS WHAT THE STRONG
MOISTURE ADVECTION WILL DO OVERNIGHT AND EARLY TUESDAY MORNING.
MODELS ARE KEEPING THE FORCING FROM THE NORTHERN PLAINS SHORTWAVE TO
THE NORTH OF THE FORECAST AREA...AND A DECENT ELEVATED MIXED LAYER
IS PROGGED TO KEEP THE BOUNDARY LAYER CAPPED. THEREFORE CHANCES FOR
MEASURABLE PRECIP LOOK PRETTY SLIM AS A COLD FRONT ASSOCIATED WITH
THE NORTHERN PLAINS WAVE PUSHES THROUGH THE AREA DURING THE DAY
TUESDAY. HOWEVER LOW LEVEL MOISTURE IS EXPECTED TO CONTINUE TO
ADVECT NORTH INTO EASTERN KS THROUGH THE NIGHT WITH READINGS
POSSIBLY IN THE MID 40S BY SUNRISE. THE LATEST RUC AND NAM FORECAST
SOUNDINGS CONTINUE TO SHOW THE BOUNDARY LAYER SATURATING BY 12Z
AHEAD OF THE SFC COLD FRONT. THERE ALSO APPEARS TO BE SOME WEAK LIFT
ON THE 285K ISENTROPIC SFC AHEAD OF THE FRONT. THEREFORE DID NOT SEE
ANY REASON TO CHANGE THE MENTION OF FOG AND DRIZZLE FROM THE
PREVIOUS FORECAST. WINDS SHOULD STAY UP FAVORING MORE STRATUS THAN
FOG SO DO NOT ANTICIPATE THERE BEING A SEVERE RESTRICTION TO
VISIBILITIES AT THIS TIME. OVERNIGHT LOWS WILL BE MILD DUE TO THE
WARM AIR AND MOISTURE MOVING NORTH. FOR HIGHS TUESDAY...THE MODELS
ARE MIXING THE BOUNDARY LAYER TO AT LEAST 900 MB WITH NOT A WHOLE
LOT OF COLD AIR BEHIND THE FRONT. BECAUSE OF THIS...HAVE BUMPED HIGHS
UP INTO THE UPPER 50S AND AROUND 60 THINKING THERE SHOULD BE ENOUGH
INSOLATION IN THE AFTERNOON TO HELP TEMPS WARM.
WOLTERS
FOR TUESDAY NIGHT THROUGH THURSDAY...MID AND HIGH LEVEL CLOUDS COULD
BE RATHER PERSISTENT...WITH A BRIEF BREAK LATE WEDNESDAY...WITH MID
AND LOW LEVELS STILL ON THE DRY SIDE BEHIND THE COLD FRONT. AS
MENTIONED ABOVE...AIRMASS COMING IN BEHIND IS ONLY SLIGHTLY COOLER
THAN TUESDAY...BUT MIXING WILL BE MORE LIMITED FOR WEDNESDAY SO
EXPECT SOMEWHAT COOLER TEMPS. FAVORING THE MORE-AGREED-UPON SLOWER
MODELS OVER THE NAM FOR THURSDAY...WITH WEAK MID LEVEL WARM AIR
ADVECTION BRINGING IN DEEPENING HIGH CLOUDS THURSDAY AFTERNOON AS
THE WESTERN UPPER TROF DIGS INTO THE ROCKIES. TEMPS IN THE LOW TO
MID 50S STILL EXPECTED UNDER EASTERLY WINDS.
MEDIUM RANGE MODELS CONTINUE TO COME TOGETHER WITH THE UPPER TROF AT
LEAST PARTIALLY CUTTING OFF FROM THE FLOW FOR THE LATE WEEK AND
WEEKEND PERIODS. OF COURSE ANY SPECIFICS ARE FAR FROM CERTAIN...BUT
PRECIPITATION FALLING ON MOST LOCATIONS AT LEAST ONCE IN THIS PERIOD
IS BECOMING A GOOD BET. STILL APPEARS TEMPS MAY BE COLD ENOUGH TO
SUPPORT SOME SNOW...BUT AGAIN MUCH TO BE DETERMINED HERE. OVERALL
TEMPS NOT EXPECTED TO STRAY FAR FROM EARLY FEBRUARY NORMALS.
65
&&
.AVIATION...
WEAK MOISTURE ADVECTION TONIGHT WILL CAUSE SOME LIGHT FOG AND MVFR
STRATUS...PERHAPS IFR STRATUS AT KTOP AND KFOE...TO DEVELOP AFTER
9Z. IF STRATUS AND LIGHT FOG DOES DEVELOP IT SHOULD MIX OUT BY 17Z
TUE. A COLD FRONT WILL SHIFT WINDS TO THE NORTHWEST AT THE TAF
SITES BY 18Z TUE...WIND SPEEDS WILL BE UNDER 11KTS BEHIND THE FRONT.
GARGAN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1207 PM EST SUN JAN 29 2012
...Updated Aviation Discussion...
...Forecast Update...
Winds have begun to become gusty over the last hour with a couple of
sites gusting to around 30 mph already. For now will keep the wind
advisory in place where it is and watch observations to see if it
needs to be expanded later. Made some minor tweaks to the grids to
update them based on current conditions. Also removed the pops from
the far northern part of the forecast area this afternoon. While a
few flurries or sprinkles are not out of the question, the main area
of precipitation should remain to our north. Other than that, no
major changes. Updates will be out soon.
&&
.Short Term (Today and Tonight)...
...A Windy Day Ahead...
The main challenges in the short term period are gusty winds today
and the slight chance for precip over southeast Indiana and the
northern Bluegrass. These challenges are courtesy of an upper level
wave crossing the Great Lakes and associated sfc front passing
through our area this afternoon.
First of all, light precip may fall over southeast Indiana and the
northern Bluegrass from 18Z-0Z. The latest RR model has the best
handle on this precip which was over southern MN, central Iowa, and
western WI as of 730Z. This clipper will push a thin band of low
level moisture into the Ohio Valley this afternoon. Model soundings
indicate temps will be cold enough aloft for ice crystal
production. However, sfc temps will be in the upper 30s and low 40s
by the afternoon hours, so precip should reach the sfc as just plain
rain with maybe some ice pellets mixing in. Precip will exit the
area by 0Z.
As for winds, a 35-40 kt LLJ will push through our area just ahead
of the front today. This will create the potential for wind gusts
in the 30-40 mph range over southern Indiana and central KY. Will
go ahead and issue an SPS for most of this area. Over the Bluegrass
region, however, it looks like the LLJ will cross during peak mixing
which may cause peak wind gusts in the 40 to 45 mph range. GFS,
SREF, and NAM soundings all indicate gusts into this range,
therefore, felt confident enough to issue a wind advisory along and
east of a line from Scott County to Casey County in KY. This
matches well with ILN wind advy and JKL lake wind advy. The
Bluegrass advy will be valid from 16Z-23Z.
As for temps, we should see a gradient of highs from north to south
today with the colder, cloudier southern Indiana/northern KY area
only reaching the lower 40s for highs while the warmer, sunnier
south central KY area reaches the upper 40s. Low temps tonight
should cool into the mid 20s to around 30.
.Long Term (Monday through Saturday)...
We`ll sit under a fairly flat flow early in the long term, until a
weak wave moves into the Great Lakes Tuesday night...then a slightly
stronger one enters the Ohio Valley Wednesday night, and then a much
deeper upper trof dives into much of the eastern United States
Friday-Saturday. This should translate into tranquil weather early
in the long term and then increasingly unsettled conditions (not to
mention model disagreement) in later periods.
Will lean, with great trepidation, towards a blend of the
operational GFS/GFS ensemble mean/GEM ensemble mean, which are in
decent (albeit tenuous) agreement with each other. The operational
ECMWF goes off on its own by late in the week and is not in good
agreement with its own ensemble mean (which has some similarities to
the above mentioned suite of models). Unfortunately since there is
so much disagreement among the models it`s difficult to put much
faith in any solution.
Forging ahead anyway, at this time we will go with high pressure
over the southeast U.S. Monday-Tuesday. A tight gradient on the
backside of the high will pump warm air northward on stiff SSW
breezes. As a result, we went with rather warm temperatures for the
first couple of days of the new work week, including at night since
it appears the breezes will keep up around 10mph even after sunset.
Tuesday night should be especially warm ahead of an approaching cold
front. We should see gusts to at least 25 mph Monday afternoon and
30 mph Tuesday afternoon.
That cold front will approach from the northwest Tuesday night and
push through the LMK CWA on Wednesday, weakening as it does so.
Showers look likely with this feature Tuesday night-Wednesday,
tapering off Wednesday evening. No thunder is expected.
Thursday through Saturday are a mess in the model data. Inkling
right now is that Thursday may be dry as we sit between systems,
but given the Euro`s strong precipitation signal and in attempting
to blend with surrounding offices, will need to hang on to a small
POP.
Thursday night into Saturday a deep upper trof will dig into the
eastern U.S. and will bring chances of light, spotty precipitation
Thursday night into the weekend. Most of the precip should be in
the form of rain, though some snow could mix in late Friday night
into Saturday morning.
&&
.Aviation (18Z TAF Issuance)...
The forecast for this TAF period is mainly a wind forecast. Winds
have become gusty late this morning ahead of a cold front moving
through this afternoon. Winds will remain out of the southwest until
the front passes through the TAF sites, then shift to the west
behind the front. Peak gusts this afternoon will be in the 25-30
knot range at SDF and BWG and in the 30-35 knot range at LEX. For
tonight winds will become light and variable as high pressure slides
across the region. Winds will quickly shift back to the southwest
tomorrow morning with gusty winds once again expected through the
late morning and afternoon. Ceilings will be VFR through the TAF
period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR
KYZ036-037-040>043-
047>049-055>057-066-067.
$$
Update...........EER
Short Term.......AMS
Long Term........13
Aviation.........EER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1019 AM EST SUN JAN 29 2012
...Forecast Update...
Winds have begun to become gusty over the last hour with a couple of
sites gusting to around 30 mph already. For now will keep the wind
advisory in place where it is and watch observations to see if it
needs to be expanded later. Made some minor tweaks to the grids to
update them based on current conditions. Also removed the pops from
the far northern part of the forecast area this afternoon. While a
few flurries or sprinkles are not out of the question, the main area
of precipitation should remain to our north. Other than that, no
major changes. Updates will be out soon.
&&
.Short Term (Today and Tonight)...
...A Windy Day Ahead...
The main challenges in the short term period are gusty winds today
and the slight chance for precip over southeast Indiana and the
northern Bluegrass. These challenges are courtesy of an upper level
wave crossing the Great Lakes and associated sfc front passing
through our area this afternoon.
First of all, light precip may fall over southeast Indiana and the
northern Bluegrass from 18Z-0Z. The latest RR model has the best
handle on this precip which was over southern MN, central Iowa, and
western WI as of 730Z. This clipper will push a thin band of low
level moisture into the Ohio Valley this afternoon. Model soundings
indicate temps will be cold enough aloft for ice crystal
production. However, sfc temps will be in the upper 30s and low 40s
by the afternoon hours, so precip should reach the sfc as just plain
rain with maybe some ice pellets mixing in. Precip will exit the
area by 0Z.
As for winds, a 35-40 kt LLJ will push through our area just ahead
of the front today. This will create the potential for wind gusts
in the 30-40 mph range over southern Indiana and central KY. Will
go ahead and issue an SPS for most of this area. Over the Bluegrass
region, however, it looks like the LLJ will cross during peak mixing
which may cause peak wind gusts in the 40 to 45 mph range. GFS,
SREF, and NAM soundings all indicate gusts into this range,
therefore, felt confident enough to issue a wind advisory along and
east of a line from Scott County to Casey County in KY. This
matches well with ILN wind advy and JKL lake wind advy. The
Bluegrass advy will be valid from 16Z-23Z.
As for temps, we should see a gradient of highs from north to south
today with the colder, cloudier southern Indiana/northern KY area
only reaching the lower 40s for highs while the warmer, sunnier
south central KY area reaches the upper 40s. Low temps tonight
should cool into the mid 20s to around 30.
.Long Term (Monday through Saturday)...
We`ll sit under a fairly flat flow early in the long term, until a
weak wave moves into the Great Lakes Tuesday night...then a slightly
stronger one enters the Ohio Valley Wednesday night, and then a much
deeper upper trof dives into much of the eastern United States
Friday-Saturday. This should translate into tranquil weather early
in the long term and then increasingly unsettled conditions (not to
mention model disagreement) in later periods.
Will lean, with great trepidation, towards a blend of the
operational GFS/GFS ensemble mean/GEM ensemble mean, which are in
decent (albeit tenuous) agreement with each other. The operational
ECMWF goes off on its own by late in the week and is not in good
agreement with its own ensemble mean (which has some similarities to
the above mentioned suite of models). Unfortunately since there is
so much disagreement among the models it`s difficult to put much
faith in any solution.
Forging ahead anyway, at this time we will go with high pressure
over the southeast U.S. Monday-Tuesday. A tight gradient on the
backside of the high will pump warm air northward on stiff SSW
breezes. As a result, we went with rather warm temperatures for the
first couple of days of the new work week, including at night since
it appears the breezes will keep up around 10mph even after sunset.
Tuesday night should be especially warm ahead of an approaching cold
front. We should see gusts to at least 25 mph Monday afternoon and
30 mph Tuesday afternoon.
That cold front will approach from the northwest Tuesday night and
push through the LMK CWA on Wednesday, weakening as it does so.
Showers look likely with this feature Tuesday night-Wednesday,
tapering off Wednesday evening. No thunder is expected.
Thursday through Saturday are a mess in the model data. Inkling
right now is that Thursday may be dry as we sit between systems,
but given the Euro`s strong precipitation signal and in attempting
to blend with surrounding offices, will need to hang on to a small
POP.
Thursday night into Saturday a deep upper trof will dig into the
eastern U.S. and will bring chances of light, spotty precipitation
Thursday night into the weekend. Most of the precip should be in
the form of rain, though some snow could mix in late Friday night
into Saturday morning.
&&
.Aviation (12Z TAF Issuance)...
The main aviation concern for today will be winds as a weak clipper
passing over the Great Lakes will drag a weak cold front over the
TAF sites this afternoon. Along and just ahead of the front, a good
LLJ is ongoing. These strong winds aloft will give BWG, SDF, and
LEX gusty conditions today. SSW winds will pick up after sunrise
with gusts in the 20-25kt range through late morning. By the
afternoon hours, 0Z NAM Bufkit soundings indicate gusts into the
25-30 kt range...higher than that at LEX. Looking at winds in the
lower levels, the potential is there for peak gusts into the 30-38
kt range with the strongest gusts at LEX this afternoon. Have
increased TAF forecast gusts for LEX. Felt that ongoing forecast
gusts at SDF/BWG were pretty close although actual peak gusts for
the day will likely be a bit higher. A distinct wind shift from SW
to W with the weak front should occur at SDF and LEX around 21Z and
22Z respectively. The front should be too weak at BWG to create a
distinct wind shift...it may be more gradual during the early
evening hours. Gusts should decrease around or just after sunset.
VFR CIGS/VSBYs are expected through the TAF period. Any isld light
precip with the clipper system should stay to the north of the TAF
sites although LEX would stand the best chance at any isld rain
showers.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR
KYZ036-037-040>043-
047>049-055>057-066-067.
$$
Update...........EER
Short Term.......AMS
Long Term........13
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
543 AM EST SUN JAN 29 2012
...Updated Aviation Discussion...
.Short Term (Today and Tonight)...
...A Windy Day Ahead...
The main challenges in the short term period are gusty winds today
and the slight chance for precip over southeast Indiana and the
northern Bluegrass. These challenges are courtesy of an upper level
wave crossing the Great Lakes and associated sfc front passing
through our area this afternoon.
First of all, light precip may fall over southeast Indiana and the
northern Bluegrass from 18Z-0Z. The latest RR model has the best
handle on this precip which was over southern MN, central Iowa, and
western WI as of 730Z. This clipper will push a thin band of low
level moisture into the Ohio Valley this afternoon. Model soundings
indicate temps will be cold enough aloft for ice crystal
production. However, sfc temps will be in the upper 30s and low 40s
by the afternoon hours, so precip should reach the sfc as just plain
rain with maybe some ice pellets mixing in. Precip will exit the
area by 0Z.
As for winds, a 35-40 kt LLJ will push through our area just ahead
of the front today. This will create the potential for wind gusts
in the 30-40 mph range over southern Indiana and central KY. Will
go ahead and issue an SPS for most of this area. Over the Bluegrass
region, however, it looks like the LLJ will cross during peak mixing
which may cause peak wind gusts in the 40 to 45 mph range. GFS,
SREF, and NAM soundings all indicate gusts into this range,
therefore, felt confident enough to issue a wind advisory along and
east of a line from Scott County to Casey County in KY. This
matches well with ILN wind advy and JKL lake wind advy. The
Bluegrass advy will be valid from 16Z-23Z.
As for temps, we should see a gradient of highs from north to south
today with the colder, cloudier southern Indiana/northern KY area
only reaching the lower 40s for highs while the warmer, sunnier
south central KY area reaches the upper 40s. Low temps tonight
should cool into the mid 20s to around 30.
.Long Term (Monday through Saturday)...
We`ll sit under a fairly flat flow early in the long term, until a
weak wave moves into the Great Lakes Tuesday night...then a slightly
stronger one enters the Ohio Valley Wednesday night, and then a much
deeper upper trof dives into much of the eastern United States
Friday-Saturday. This should translate into tranquil weather early
in the long term and then increasingly unsettled conditions (not to
mention model disagreement) in later periods.
Will lean, with great trepidation, towards a blend of the
operational GFS/GFS ensemble mean/GEM ensemble mean, which are in
decent (albeit tenuous) agreement with each other. The operational
ECMWF goes off on its own by late in the week and is not in good
agreement with its own ensemble mean (which has some similarities to
the above mentioned suite of models). Unfortunately since there is
so much disagreement among the models it`s difficult to put much
faith in any solution.
Forging ahead anyway, at this time we will go with high pressure
over the southeast U.S. Monday-Tuesday. A tight gradient on the
backside of the high will pump warm air northward on stiff SSW
breezes. As a result, we went with rather warm temperatures for the
first couple of days of the new work week, including at night since
it appears the breezes will keep up around 10mph even after sunset.
Tuesday night should be especially warm ahead of an approaching cold
front. We should see gusts to at least 25 mph Monday afternoon and
30 mph Tuesday afternoon.
That cold front will approach from the northwest Tuesday night and
push through the LMK CWA on Wednesday, weakening as it does so.
Showers look likely with this feature Tuesday night-Wednesday,
tapering off Wednesday evening. No thunder is expected.
Thursday through Saturday are a mess in the model data. Inkling
right now is that Thursday may be dry as we sit between systems,
but given the Euro`s strong precipitation signal and in attempting
to blend with surrounding offices, will need to hang on to a small
POP.
Thursday night into Saturday a deep upper trof will dig into the
eastern U.S. and will bring chances of light, spotty precipitation
Thursday night into the weekend. Most of the precip should be in
the form of rain, though some snow could mix in late Friday night
into Saturday morning.
&&
.Aviation (12Z TAF Issuance)...
The main aviation concern for today will be winds as a weak clipper
passing over the Great Lakes will drag a weak cold front over the
TAF sites this afternoon. Along and just ahead of the front, a good
LLJ is ongoing. These strong winds aloft will give BWG, SDF, and
LEX gusty conditions today. SSW winds will pick up after sunrise
with gusts in the 20-25kt range through late morning. By the
afternoon hours, 0Z NAM Bufkit soundings indicate gusts into the
25-30 kt range...higher than that at LEX. Looking at winds in the
lower levels, the potential is there for peak gusts into the 30-38
kt range with the strongest gusts at LEX this afternoon. Have
increased TAF forecast gusts for LEX. Felt that ongoing forecast
gusts at SDF/BWG were pretty close although actual peak gusts for
the day will likely be a bit higher. A distinct wind shift from SW
to W with the weak front should occur at SDF and LEX around 21Z and
22Z respectively. The front should be too weak at BWG to create a
distinct wind shift...it may be more gradual during the early
evening hours. Gusts should decrease around or just after sunset.
VFR CIGS/VSBYs are expected through the TAF period. Any isld light
precip with the clipper system should stay to the north of the TAF
sites although LEX would stand the best chance at any isld rain
showers.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM EST THIS EVENING
FOR THE BLUEGRASS.
$$
Short Term.......AMS
Long Term........13
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
306 AM EST SUN JAN 29 2012
.Short Term (Today and Tonight)...
...A Windy Day Ahead...
The main challenges in the short term period are gusty winds today
and the slight chance for precip over southeast Indiana and the
northern Bluegrass. These challenges are courtesy of an upper level
wave crossing the Great Lakes and associated sfc front passing
through our area this afternoon.
First of all, light precip may fall over southeast Indiana and the
northern Bluegrass from 18Z-0Z. The latest RR model has the best
handle on this precip which was over southern MN, central Iowa, and
western WI as of 730Z. This clipper will push a thin band of low
level moisture into the Ohio Valley this afternoon. Model soundings
indicate temps will be cold enough aloft for ice crystal
production. However, sfc temps will be in the upper 30s and low 40s
by the afternoon hours, so precip should reach the sfc as just plain
rain with maybe some ice pellets mixing in. Precip will exit the
area by 0Z.
As for winds, a 35-40 kt LLJ will push through our area just ahead
of the front today. This will create the potential for wind gusts
in the 30-40 mph range over southern Indiana and central KY. Will
go ahead and issue an SPS for most of this area. Over the Bluegrass
region, however, it looks like the LLJ will cross during peak mixing
which may cause peak wind gusts in the 40 to 45 mph range. GFS,
SREF, and NAM soundings all indicate gusts into this range,
therefore, felt confident enough to issue an wind advisory from
along and east of a line from Scott County to Casey County in KY.
This matches well with ILN wind advy and JKL lake wind advy. The
Bluegrass advy will be valid from 16Z-23Z.
As for temps, we should see a gradient of highs from north to south
today with the colder, cloudier southern Indiana/northern KY area
only reaching the lower 40s for highs while the warmer, sunnier
south central KY area reaches the upper 40s. Low temps tonight
should cool into the mid 20s to around 30.
.Long Term (Monday through Saturday)...
We`ll sit under a fairly flat flow early in the long term, until a
weak wave moves into the Great Lakes Tuesday night...then a slightly
stronger one enters the Ohio Valley Wednesday night, and then a much
deeper upper trof dives into much of the eastern United States
Friday-Saturday. This should translate into tranquil weather early
in the long term and then increasingly unsettled conditions (not to
mention model disagreement) in later periods.
Will lean, with great trepidation, towards a blend of the
operational GFS/GFS ensemble mean/GEM ensemble mean, which are in
decent (albeit tenuous) agreement with each other. The operational
ECMWF goes off on its own by late in the week and is not in good
agreement with its own ensemble mean (which has some similarities to
the above mentioned suite of models). Unfortunately since there is
so much disagreement among the models it`s difficult to put much
faith in any solution.
Forging ahead anyway, at this time we will go with high pressure
over the southeast U.S. Monday-Tuesday. A tight gradient on the
backside of the high will pump warm air northward on stiff SSW
breezes. As a result, we went with rather warm temperatures for the
first couple of days of the new work week, including at night since
it appears the breezes will keep up around 10mph even after sunset.
Tuesday night should be especially warm ahead of an approaching cold
front. We should see gusts to at least 25 mph Monday afternoon and
30 mph Tuesday afternoon.
That cold front will approach from the northwest Tuesday night and
push through the LMK CWA on Wednesday, weakening as it does so.
Showers look likely with this feature Tuesday night-Wednesday,
tapering off Wednesday evening. No thunder is expected.
Thursday through Saturday are a mess in the model data. Inkling
right now is that Thursday may be dry as we sit between systems,
but given the Euro`s strong precipitation signal and in attempting
to blend with surrounding offices, will need to hang on to a small
POP.
Thursday night into Saturday a deep upper trof will dig into the
eastern U.S. and will bring chances of light, spotty precipitation
Thursday night into the weekend. Most of the precip should be in
the form of rain, though some snow could mix in late Friday night
into Saturday morning.
&&
.Aviation (06Z TAF Issuance)...
The main aviation concern for the next 24-30 hrs will be winds as a
weak clipper passing over the Great Lakes today will drag a weak
cold front over the TAF sites this afternoon. Ahead of the front, a
good LLJ will get going overnight. However, as noted with the
evening update, models are a little slower with the system and thus
the LLJ will be delayed into SDF. By the time it reaches SDF around
13-15Z, good mixing will have already begun and thus decided to take
the LLWS out of SDF TAF. Nevertheless, SW winds will certainly pick
up after sunrise with gusts in the 20-25kt range through late
morning. By the afternoon hours, 0Z NAM Bufkit soundings indicate
gusts into the 25-30 kt range. Looking at winds in the lower
levels, the potential is there for gusts into the 30-35 kt range.
Gusts in the 6Z TAFs are more of an average afternoon range, but it
should be noted that peak gusts for the day will likely be higher.
A distinct wind shift from SW to W with the weak front should occur
at SDF and LEX around 21Z and 22Z respectively. The front should be
too weak at BWG to create a distinct wind shift...it may be more
gradual during the late afternoon/early evening hours. Gusts should
decrease around or just after sunset. VFR CIGS/VSBYs are expected
through the TAF period. Any isld light precip with the clipper
system should stay to the north of the TAF sites.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM EST THIS EVENING
FOR THE BLUEGRASS REGION.
$$
Short Term.......AMS
Long Term........13
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
624 PM EST MON JAN 30 2012
.SYNOPSIS...
WITH A WARM FRONT HAVING GONE NORTH TO THE GREAT LAKES, EXPECT DRY
AND MILD CONDITIONS TONIGHT AND TUESDAY. A COLD FRONT WILL BRING
RAIN SHOWERS TUESDAY NIGHT AND WEDNESDAY AND RETURN TEMPERATURES
TO SEASONABLE LEVELS.
&&
.NEAR TERM /THROUGH TUESDAY/...
NO CHANGES FOR THE EARLY EVE UPDATE OTHER THAN TO TWEAK HOURLY TRENDS.
RECENT SATELLITE DATA SHOWS THICK CLOUDS, ASSOCIATED WITH A
NORTHWARD-MOVING WARM FRONT, PASSING EASTWARD ACROSS THE I-80
CORRIDOR THIS EVENING, SO HAVE MAINTAINED MENTION OF ISOLATED
FLURRIES FOR THAT AREA.
THE REST OF THE UPPER OHIO VALLEY CAN EXPECT CLOUDS TO DECREASE
OVERNIGHT. WITH THE UPPER OHIO VALLEY IN THE SO-CALLED WARM SECTOR
DAYTIME TUESDAY, EXPECT THERE TO MORE FREQUENT PERIODS OF
SUNSHINE.
FORECASTED TEMPERATURES FOR TONIGHT, USING BLEND OF HRRR AND GFS
LAMP MODEL OUTPUT. THIS SHOWED TEMPERATURES WILL ONLY DROP A
COUPLE DEGREES OVERNIGHT, MAKING LOWS AT LEAST 10 DEGREES WARMER
THAN NORMAL.
FOR TEMPERATURES TUESDAY, RELIED MORE ON NAM AND GFS MOS OUTPUT
WHICH SHOWED AFTERNOON HIGHS CAN BE UP TO 15-20 DEGREES WARMER
THAN NORMAL.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW A LOW PRESSURE SYSTEM,
COMING SOUTHEAST FROM ALBERTA, PUSHING A COLD FRONTAL BAND OF SHOWERS
THROUGH THE UPPER OHIO VALLEY LATE TUESDAY NIGHT AND WEDNESDAY
MORNING. IN THE PREFRONTAL SOUTHWEST FLOW, BLEND OF GFS AND NAM
MOS SHOWED LOW TEMPERATURES TUESDAY NIGHT CAN BE WARMER THAN
NORMAL JANUARY HIGHS.
WITH THE UPPER LEVEL JETSTREAM BECOMING MORE WESTERLY MID-WEEK,
EXPECT A WEAK POST FRONTAL COOL DOWN WEDNESDAY AFTERNOON. HENCE FORECASTED
TEMPERATURES WEDNESDAY, AGAIN USING BLEND OF GFS AND NAM MOS, TO
YIELD EARLY AFTERNOON HIGHS UP TO 15 DEGREES WARMER THAN NORMAL.
THERE CAN BE LINGERING COLD POOL STRATOCUMULUS WEDNESDAY NIGHT AND THURSDAY,
WITH PERHAPS A MIX OF LIGHT RAIN AND SNOW SHOWERS ACROSS ON THE
WINDWARD SLOPES OF THE MOUNTAINS.
GFS AND NAM MOS SHOWED TEMPERATURES THURSDAY NOT AS WARM AS
WEDNESDAY, BUT STILL 5-8 DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR THIS PERIOD REMAINS DIFFICULT DESPITE COMMON
LONG WAVE PATTERN SIMILARITIES BETWEEN THE DETERMINISTIC MODELS.
AS HAS BEEN THE CASE OVER THE LAST FEW DAYS...A DEEP POSITIVELY
TILTED TROUGH WILL DEVELOP OVER THE EASTERN EDGE OF THE
ROCKIES...WITH A STRONG FOLD-OVER RIDGE OVER THE WESTERN U.S.
WHERE THE MODELS DIFFER IS IN TIMING. SOME OF THE MODELS SUGGEST
THAT THE LOW WILL REMAIN ESSENTIALLY CUTOFF FROM THE REST OF THE
FLOW WHILE OTHERS EJECT THE LOW EASTWARD FAIRLY QUICKLY. THE SPLIT
FLOW PATTERN IS WHAT IS MAKING THE SMALLER SHORTWAVE TIMING AND
PLACEMENT DIFFICULT.
HAVE OPTED TO REMAIN CLOSEST TO HPC AND IN TURN ACCOUNT FOR GENERAL
SHORTWAVE PATTERN SIMILARITIES BETWEEN THE 00Z ECMWF AND 06/12Z GFS
THROUGH THE PERIOD. MAINTAINED ONLY LOW CHANCE POPS THROUGH MOST OF
THE PERIOD WITH SUCH MODEL UNCERTAINTY AND TEMPERATURES CLOSE TO AN
HPC/MEX BLEND.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD AS AS A WARM
FRONT PUSHES NORTH OF THE REGION.
WINDS TONIGHT WILL BE LIGHT SOUTHERLY WITH AT THE SURFACE WITH LOW
LEVEL WIND SHEAR LIKELY AS MODEL PROFILES SHOW A STABLE SURFACE
LAYER WITH WINDS INCREASING TO 45 TO 50 KTS AROUND 2 KFT AGL
OVERNIGHT INTO EARLY TUESDAY. MIXING WILL BRING SOME GUSTS DOWN TO
THE SURFACE MID MORNING TUESDAY WITH GUSTS TO 25KTS POSSIBLE.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
VFR CONDITIONS WILL CONTINUE TUESDAY EVENING. A COLD FRONTAL BAND
OF SHOWERS WILL PROVIDE RESTRICTIONS LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING. POST FRONTAL STRATOCUMULUS MAY CAUSE CEILING
RESTRICTIONS TO LINGER INTO THURSDAY. VFR CONDITIONS WILL RETURN TO
THE TERMINALS ON FRIDAY AS HIGH PRESSURE BUILDS INTO THE AREA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/10
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
600 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT CAN BRING STRONG WIND GUSTS AND A MIX OF
LIGHT RAIN SLEET AND SNOW SHOWERS THIS EVENING. HIGH PRESSURE PASSING
TO THE SOUTH WILL THEN PROVIDE DRY SEASONABLE CONDITIONS MONDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
QUICK EARLY EVE UPDATE ISSUED BASED ON CURRENT TRENDS OF +SNOW
SHOWERS AND ACCUMULATION TO AROUND AN INCH.
HAVE CONTINUED THE WIND ADVISORY FOR GUSTS OVER 45 MPH THIS
EVENING WITH THE PASSAGE OF THE COLD FRONT. TIMING AND WIND GUSTS
BASED ON RADAR AND OBS. TRENDS. WIND WILL DIMINISH IN THE WAKE OF
THE FRONT.
BASED ON RECENT NAM AND HRRR MODEL VALUES, FORECASTED LOW
TEMPERATURES TO BE NEAR NORMAL,
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
ON MONDAY, SREF MODEL OUTPUT SHOWS THE UPPER JETSTREAM FLOW BACKING
SLIGHTLY INTO THE WEST SOUTHWEST. HENCE THE NEXT SHORT WAVE WILL
TO PASS EASTWARD THROUGH THE GREAT LAKES SHOULD HAVE LESS IMPACT
ON THE UPPER OHIO VALLEY. STILL INCLUDED A CHANCE OF SHOWERS OF
SNOW, BUT MAINLY NORTH. REST OF THE UPPER OHIO VALLEY WILL STAY
DRY THROUGH DAYTIME TUESDAY.
SREF MODEL OUTPUT THEN SHOWS THE NORTHERN JETSTREAM BRANCH GAINING
MORE INFLUENCE. THIS WILL STEER A LOW PRESSURE SYSTEM TO MOVE
SOUTHEAST FROM THE CANADIAN ROCKIES TO PUSH A COLD FRONT WITH RAIN
SHOWERS THROUGH THE UPPER OHIO VALLEY DAYTIME WEDNESDAY.
FORECAST TEMPERATURES THIS PERIOD USING BLEND OF GFS AND NAM MOS.
THIS GUIDANCE SHOWED HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN
NORMAL, AND LOWS AND HIGHS TUESDAY AND WEDNESDAY TO BE NEARLY 15
DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS WAS THE CASE YESTERDAY...MODELS CONTINUE TO HAVE TROUBLE
RESOLVING THE PLACEMENT AND TIMING OF SYSTEMS DURING THIS PERIOD.
WHILE ALL THE MODELS CONTINUE TO SUGGEST A DEEPENING LONG WAVE
PATTERN...WITH A STRONG RIDGE OVER THE WESTERN U.S AND A DEEP TROUGH
OVER THE EASTERN U.S...THE SHORTWAVE PATTERN AND IN TURN LOW
PLACEMENT REMAINS INCONSISTENT FROM RUN TO RUN.
IN GENERAL...MODELS SUGGEST THAT THE COLD FRONT...PROGGED TO CROSS
THE OHIO VALLEY DURING THE DAY WEDNESDAY...WILL HANG UP AROUND THE
MASON-DIXON LINE AND EVENTUALLY MOVE NORTHWARD AS A WARM FRONT. THE
QUESTION IS WHEN AND HOW FAR NORTH WILL THE SYSTEM MAKE IT AT THIS
POINT.
CONTINUED TO REMAIN CLOSE TO HPC GUIDANCE WITH ONLY LOW CHANCE POPS
THROUGH MOST OF THE PERIOD WITH SUCH MODEL UNCERTAINTY AND
TEMPERATURES CLOSE TO AN HPC MEX BLEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE FOR A FEW MORE HOURS BEFORE ANOTHER
FAST MOVING COLD FRONT IMPACTS THE TERMINALS LATER THIS AFTERNOON.
MAINTAINED MOSTLY MVFR CIGS/VSBY AT ALL SITES WITH THE SYSTEM...BUT
IFR VSBY WILL BE POSSIBLE IN SNOW SHOWERS ESPECIALLY AT KFKL AND
KDUJ. WILL GRADUALLY IMPROVE SITES BACK TO VFR OVERNIGHT PER SREF
AND LAMP GUIDANCE HOWEVER...STRATOCUMULUS MAY REMAIN UNTIL MONDAY
MORNING AS W-NW WINDS ALLOWING FOR SOME LAKE INDUCED CLOUDS.
OUT AHEAD OF AND JUST BEHIND THE SYSTEM WINDS WILL VEER FROM S-SW TO
MORE W-NW AND INCREASE TO NEAR 15-20KTS SUSTAINED WITH GUSTS TO
35KTS POSSIBLE.
OUTLOOK...MONDAY THROUGH FRIDAY...
ANOTHER CLIPPER TYPE SYSTEM MAY CAUSE SOME RESTRICTIONS TO THE
NORTHERN TAF SITES MONDAY AFTERNOON BUT MOISTURE IS RATHER LIMITED.
ELSEWHERE...VFR IS EXPECTED THROUGH WEDNESDAY. A COLD FRONT WILL
THEN BRING A GREATER CHANCE FOR RESTRICTIONS AT ALL SITES WEDNESDAY
AND THURSDAY. RESTRICTIONS MAY BE POSSIBLE FRIDAY BUT THERE IS MUCH
UNCERTAINTY IN THE FORECAST AT THIS POINT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR MDZ001.
OH...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR WVZ001>004-012-
021>023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
340 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT CAN BRING STRONG WIND GUSTS AND A MIX OF
LIGHT RAIN SLEET AND SNOW SHOWERS THIS EVENING. HIGH PRESSURE PASSING
TO THE SOUTH WILL THEN PROVIDE DRY SEASONABLE CONDITIONS MONDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
HAVE EXPANDED WIND ADVISORY FOR GUSTS OVER 45 MPH THIS EVENING
WITH THE PASSAGE OF A COLD FRONTAL BAND OF SHOWERS OF RAIN AND
SNOW AND POSSIBLY SLEET. TIMING AND WIND GUSTS BASED ON HRRR MODEL
OUTPUT. WINDS WILL DIE DOWN OVERNIGHT.
TO BE TECHNICAL, THE WEATHER TYPE OF SLEET IS REALLY GRAUPEL OR
SNOW PELLETS.
RECENT HRRR AND NAM MODEL OUTPUT THEN SHOW POST FRONTAL COOLING
PRODUCING NO MORE THAN SCATTERED LIGHT SNOW SHOWERS, MAINLY NORTH
AND MOUNTAINS. ANY SNOW ACCUMULATIONS WILL BE LESS THAN 0.5
INCHES.
BASED ON RECENT NAM AND HRRR MODEL VALUES, FORECASTED LOW
TEMPERATURES TO BE NEAR NORMAL,
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
ON MONDAY, SREF MODEL OUTPUT SHOWS THE UPPER JETSTREAM FLOW BACKING
SLIGHTLY INTO THE WEST SOUTHWEST. HENCE THE NEXT SHORT WAVE WILL
TO PASS EASTWARD THROUGH THE GREAT LAKES SHOULD HAVE LESS IMPACT
ON THE UPPER OHIO VALLEY. STILL INCLUDED A CHANCE OF SHOWERS OF
SNOW, BUT MAINLY NORTH. REST OF THE UPPER OHIO VALLEY WILL STAY
DRY THROUGH DAYTIME TUESDAY.
SREF MODEL OUTPUT THEN SHOWS THE NORTHERN JETSTREAM BRANCH GAINING
MORE INFLUENCE. THIS WILL STEER A LOW PRESSURE SYSTEM TO MOVE
SOUTHEAST FROM THE CANADIAN ROCKIES TO PUSH A COLD FRONT WITH RAIN
SHOWERS THROUGH THE UPPER OHIO VALLEY DAYTIME WEDNESDAY.
FORECAST TEMPERATURES THIS PERIOD USING BLEND OF GFS AND NAM MOS.
THIS GUIDANCE SHOWED HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN
NORMAL, AND LOWS AND HIGHS TUESDAY AND WEDNESDAY TO BE NEARLY 15
DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS WAS THE CASE YESTERDAY...MODELS CONTINUE TO HAVE TROUBLE
RESOLVING THE PLACEMENT AND TIMING OF SYSTEMS DURING THIS PERIOD.
WHILE ALL THE MODELS CONTINUE TO SUGGEST A DEEPENING LONG WAVE
PATTERN...WITH A STRONG RIDGE OVER THE WESTERN U.S AND A DEEP TROUGH
OVER THE EASTERN U.S...THE SHORTWAVE PATTERN AND IN TURN LOW
PLACEMENT REMAINS INCONSISTENT FROM RUN TO RUN.
IN GENERAL...MODELS SUGGEST THAT THE COLD FRONT...PROGGED TO CROSS
THE OHIO VALLEY DURING THE DAY WEDNESDAY...WILL HANG UP AROUND THE
MASON-DIXON LINE AND EVENTUALLY MOVE NORTHWARD AS A WARM FRONT. THE
QUESTION IS WHEN AND HOW FAR NORTH WILL THE SYSTEM MAKE IT AT THIS
POINT.
CONTINUED TO REMAIN CLOSE TO HPC GUIDANCE WITH ONLY LOW CHANCE POPS
THROUGH MOST OF THE PERIOD WITH SUCH MODEL UNCERTAINTY AND
TEMPERATURES CLOSE TO AN HPC MEX BLEND.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE FOR A FEW MORE HOURS BEFORE ANOTHER
FAST MOVING COLD FRONT IMPACTS THE TERMINALS LATER THIS AFTERNOON.
MAINTAINED MOSTLY MVFR CIGS/VSBY AT ALL SITES WITH THE SYSTEM...BUT
IFR VSBY WILL BE POSSIBLE IN SNOW SHOWERS ESPECIALLY AT KFKL AND
KDUJ. WILL GRADUALLY IMPROVE SITES BACK TO VFR OVERNIGHT PER SREF
AND LAMP GUIDANCE HOWEVER...STRATOCUMULUS MAY REMAIN UNTIL MONDAY
MORNING AS W-NW WINDS ALLOWING FOR SOME LAKE INDUCED CLOUDS.
OUT AHEAD OF AND JUST BEHIND THE SYSTEM WINDS WILL VEER FROM S-SW TO
MORE W-NW AND INCREASE TO NEAR 15-20KTS SUSTAINED WITH GUSTS TO
35KTS POSSIBLE.
OUTLOOK...MONDAY THROUGH FRIDAY...
ANOTHER CLIPPER TYPE SYSTEM MAY CAUSE SOME RESTRICTIONS TO THE
NORTHERN TAF SITES MONDAY AFTERNOON BUT MOISTURE IS RATHER LIMITED.
ELSEWHERE...VFR IS EXPECTED THROUGH WEDNESDAY. A COLD FRONT WILL
THEN BRING A GREATER CHANCE FOR RESTRICTIONS AT ALL SITES WEDNESDAY
AND THURSDAY. RESTRICTIONS MAY BE POSSIBLE FRIDAY BUT THERE IS MUCH
UNCERTAINTY IN THE FORECAST AT THIS POINT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR MDZ001.
OH...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR WVZ001>004-012-
021>023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1216 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT WILL BRING GUSTY WINDS AND A MIX OF LIGHT RAIN
SLEET AND SNOW SHOWERS INTO EARLY EVENING. HIGH PRESSURE PASSING
TO THE SOUTH WILL THEN PROVIDE DRY SEASONABLE CONDITIONS MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AFTERNOON UPDATE, BASED ON BLEND OF RECENT SURFACE AND SATELLITE
DATA, AND HRRR AND NAM MODEL OUTPUT, HAS ADJUSTED ONSET TIMING OF
FRONTAL BAND OF SHOWERS TO MID AND LATE AFTERNOON. PER NAM MODEL
PROFILES, WHICH SHOW DEEP BUT NARROW INSTABILITY, HAVE ADDED
MENTION OF A SLIGHT CHANCE OF SLEET. THIS WILL BE SIMILAR TO WHAT
HAPPENED YESTERDAY AFTERNOON.
IN REALITY, THE WEATHER TYPE IS REALLY GRAUPEL OR SNOW PELLETS,
BUT CALLING IT SLEET WILL SUFFICE.
LIKEWISE HAVE ADJUSTED WIND GUSTS, MAINTAINING WIND ADVISORY FOR
THE HIGHER MOUNTAINS. WILL CONTINUE TO MONITOR THIS SITUATION AS
RECENT HRRR MODEL OUTPUT DID SHOW GUSTS TO 45-50 MPH POSSIBLE WITH
THE COLD FRONTAL PASSAGE.
EXPECT TEMPERATURES TO BE A BIT COLDER THAN SATURDAY, HENCE LIGHT SNOW
SHOWERS CAN OCCUR FARTHER SOUTH THIS AFTERNOON. HOWEVER, MOST
TEMPERATURES WILL BE WARMER THAN FREEZING, SO SNOW ACCUMULATIONS
WILL AGAIN BE MINIMAL. AS THE UPPER LEVEL SHORT WAVES MOVES OFF
RAPIDLY TO THE EAST TONIGHT...SNOW SHOWERS WILL END.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
ON MONDAY, WITH UPPER JETSTREAM FLOW BACKING SLIGHTLY INTO THE
WEST SOUTHWEST, THE NEXT SHORT WAVE WILL TO PASS EASTWARD THROUGH
THE GREAT LAKES MAY HAVE LESS IMPACT ON THE UPPER OHIO VALLEY.
STILL INCLUDED A CHANCE OF SHOWERS OF RAIN AND SNOW, BUT MAINLY
NORTH.
FORECAST HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN SUNDAY.
RECENT ECMWF MODEL OUTPUT SHOWS A DRY BREAK MONDAY NIGHT AND
TUESDAY WITH SOUTHWEST WINDS PROVIDING A WARM UP TO 10 DEGREES
ABOVE NORMAL, PER GFS AND NAEFS VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT ON A COLD FRONT PASSAGE
WEDNESDAY AS THE ASSOCIATED LOW PRESSURE SYSTEM CROSSES NORTH OF THE
GREAT LAKES. BEYOND WEDNESDAY...THERE ARE INCONSISTENCIES FROM
RUN TO RUN WITH THE DETERMINISTIC MODELS KEEPING CONFIDENCE
RELATIVELY LOW ESPECIALLY INTO FRIDAY AND SATURDAY.
ALL MODELS SUGGEST A GRADUAL DEEPENING LONG WAVE TROUGH OVER THE
CENTRAL U.S WITH THE GFS THE STRONGEST AND THE ECMWF AND GEFS
ENSEMBLES REMAINING LESS AMPLIFIED. THIS IN TURN MAKES LOW
PLACEMENT SIGNIFICANTLY DIFFERENT BETWEEN THE MODELS. WITH SUCH A
WIDE SPREAD...OPTED TO REMAIN CLOSE TO HPC GUIDANCE FOR THE PERIOD
FROM THURSDAY THROUGH SATURDAY...WHICH IS CLOSEST TO THE 00/12Z
ECMWF AND GEFS. THIS WOULD BRING A SURFACE LOW SOUTH ALONG THE
APPALACHIANS AND OFF THE COAST BY FRIDAY.
KEPT TEMPERATURES CLOSE TO AN HPC MEX BLEND WHICH SEEMED TO MATCH UP
WELL WITH NAEFS TRENDS.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE FOR A FEW MORE HOURS BEFORE ANOTHER
FAST MOVING COLD FRONT IMPACTS THE TERMINALS LATER THIS AFTERNOON.
MAINTAINED MOSTLY MVFR CIGS/VSBY AT ALL SITES WITH THE SYSTEM...BUT
IFR VSBY WILL BE POSSIBLE IN SNOW SHOWERS ESPECIALLY AT KFKL AND
KDUJ. WILL GRADUALLY IMPROVE SITES BACK TO VFR OVERNIGHT PER SREF
AND LAMP GUIDANCE HOWEVER...STRATOCUMULUS MAY REMAIN UNTIL MONDAY
MORNING AS W-NW WINDS ALLOWING FOR SOME LAKE INDUCED CLOUDS.
OUT AHEAD OF AND JUST BEHIND THE SYSTEM WINDS WILL VEER FROM S-SW TO
MORE W-NW AND INCREASE TO NEAR 15-20KTS SUSTAINED WITH GUSTS TO
35KTS POSSIBLE.
OUTLOOK...MONDAY THROUGH FRIDAY...
ANOTHER CLIPPER TYPE SYSTEM MAY CAUSE SOME RESTRICTIONS TO THE
NORTHERN TAF SITES MONDAY AFTERNOON BUT MOISTURE IS RATHER LIMITED.
ELSEWHERE...VFR IS EXPECTED THROUGH WEDNESDAY. A COLD FRONT WILL
THEN BRING A GREATER CHANCE FOR RESTRICTIONS AT ALL SITES WEDNESDAY
AND THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR MDZ001.
OH...NONE.
PA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR PAZ074-076.
WV...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
449 PM EST SUN JAN 29 2012
.SHORT TERM /TONIGHT AND MONDAY/...
WV IMAGERY AND RUC ANALYSIS SHOWS THE UPPER TROUGH THAT HAS BEEN
OVER THE UPPER GREAT LAKES OVER THE LAST DAY STARTING TO SHIFT TO
THE EAST. UPSTREAM...BROAD MOISTURE PLUME RUNNING OVER THE RIDGE
OVER THE US/CANADIAN ROCKIES AND MOVING INTO THE NRN PLAINS. CLOSER
TO HOME...VIS SATELLITE SHOWING LAKE EFFECT CLOUDS HANGING ON OVER
MUCH OF UPPER MICHIGAN...BUT DRIER AIR FROM THE APPROACHING SFC
RIDGE IN MN HAS QUICKLY ATE AWAY AT THE CLOUDS/SHOWERS OVER WRN LK
SUPERIOR. OVER THE ERN LK...LES CONTINUES...ALTHOUGH THE DRIER AIR
HAS STARTED TO DIMINISH THE INTENSITY OF THE SHOWERS...WHICH KMQT
RADAR IS SHOWING MAINLY 1HR SNOWFALL RATES OF 0.5 IN/HR. THE
STRONGEST SWRN BAND NEAR MUNISING HAS PICKED UP SLIGHTLY OVER THE
LAST HOUR...AS LLVL WINDS OFF MARQUETTE COUNTY HAVE SHIFTED SLIGHTLY
TO THE WNW AND INCREASED CONVERGENCE.
TONIGHT...WITH THE UPPER TROUGH CONTINUING TO PUSH E...SFC RIDGE
CURRENTLY OVER THE MN WILL PUSH INTO THE AREA. H850-700 SUBSIDENCE
AND DRY AIR ALREADY TAKEN HOLD OVER WRN LK SUPERIOR AND DIMINISHED
THE -SHSN OVER THE WRN CWA. AS SFC HIGH BUILDS INTO UPPER MI THIS
EVENING...WINDS WILL BE BACKING THROUGH THE EVENING HOURS AND END UP
FOCUSING ANY LINGERING LES OVER THE KEWEENAW PENINSULA BY MIDNIGHT.
SINCE INVERSION HEIGHTS ON BUFKIT SOUNDINGS OVER THE KEWEENAW ARE
ONLY AROUND 3KFT...DON/T EXPECT MUCH FOR ACCUMULATIONS...ESPECIALLY
WITH THE TRANSIENT NATURE OF THE LES.
OVER ERN ALGER AND LUCE COUNTIES...EXPECT LES TO BE ONGOING AT THE
START OF THE TONIGHT PERIOD WITH THE NW FLOW AND -18C H850 TEMPS.
DEEPER MOISTURE WILL DEPART LATE THIS AFTN AS SUBSIDENCE FROM
H850-700 WITH THE UPPER RIDGING WILL CAUSE INVERSION HEIGHTS TO FALL
TO 4-5KFT. STILL SHOULD SEE LES CONTINUING IN THE NW WIND SNOW BELTS
FROM MUNISING E THIS EVENING...BUT INTENSITY WILL BE LOWER THAN
TODAY. IN ADDITION...WITH WINDS BACKING TO THE W BY MIDNIGHT AND
THEN SW BY DAYBREAK...THE BANDS SHOULD BE SHIFTING TO THE ENE FROM
LATE EVENING ON. THUS...EXPECT LIMITED ACCUMULATION DUE TO THE
TRANSIENT NATURE OF THE BANDS AND WILL LET THE WARNING CONTINUE
UNTIL 00Z.
LOWS TONIGHT ARE VERY TRICKY...SINCE CLEARING SKIES...WEAKENING
WINDS WITH THE SFC RIDGE...AND PWATS AROUND 35 PERCENT OF NORMAL
LEAD TO A FAVORABLE RADIATION COOLING NIGHT. FORECAST IS DIFFICULT
DUE TO THE APPROACHING HIGH CLOUDS CURRENTLY MOVING INTO WRN MN.
THESE SHOULD START TO ARRIVE AFTER MIDNIGHT AND CAUSE FOR STEADY OR
RISING TEMPS LATE. WENT WITH A NON-DIURNAL TREND AND HAVE LOWS ALONG
THE WI BORDER IN THE MID SINGLE DIGITS BELOW ZERO AND WOULD NOT BE
SURPRISED IF THEY GET EVEN COLDER IF CLOUDS ARE DELAYED.
LATE TONIGHT INTO MONDAY...CLIPPER SYSTEM CURRENTLY TAKING SHAPE IN
ALBERTA WILL SLIDE A WARM FRONT ACROSS MN AND WI ON MON. H700-500
WAA AND MOISTURE...ALONG WITH ISENTROPIC ASCENT ON THE 275-300K SFCS
PUSHES ACROSS THE AREA FROM SW TO NE BETWEEN 09Z AND 18Z MON. BEST
MID LVL WAA LOOKS TO FOCUS OVER THE S HALF OF UPPER MI...MAINLY OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE. WILL FOLLOW THAT SOLN FOR
QPF AMNTS FOR LATE TONIGHT INTO MON MORNING. WITH A GOOD CONSENSUS
ON FORCING/QPF/TIMING...HAVE BUMPED POPS UP TO LIKELY FOR MOST OF
THE LAND AREAS.
12Z NAM/GFS/GEM-REG CONSISTENT ON 0.12-0.2IN OF QPF OVER THE SRN
HALF OF UPPER MI BY MON EVENING AND MADE SOME MINOR ADJUSTMENTS UP
FROM PREVIOUS SHIFT. COBB OUTPUT FOR KESC/KIMT SHOWING HIGH RATIOS
AROUND 15/18-1 INITIALLY...THEN FALLING BELOW 10-1 HEADING INTO THE
AFTN AS THE DEEPER MOISTURE IS CUT OUT REMAINING FORCING/MOISTURE IS
BELOW THE DGZ. THINK MUCH OF THE SNOW WILL FALL IN THE HIGHER SNOW
RATIO PERIOD AND USED THAT AS THE STARTING POINT FOR SNOWFALL.
EXPECT A PERIOD OF LK ENHANCEMENT AFTER 15Z ON MON...WHEN LLVL
MOISTURE PROFILES FINALLY MOISTEN UP AND SRLY WINDS TAKE HOLD. WITH
H850 TEMPS AROUND -11C DURING THE PCPN PERIOD...SHOULD BE ENOUGH
LLVL INSTABILITY TO PROVIDE ENHANCEMENT OVER DELTA/SCHOOLCRAFT/LUCE
COUNTIES AND HAVE BUMPED UP QPF AMNTS SLIGHTLY IN THOSE
AREAS...ESPECIALLY SCHOOLCRAFT/LUCE. OVERALL...HAVE A GENERAL 1-2IN
OVER MUCH OF THE CWA. COULD BE SOME ISOLATED ADVY AMNTS OF 3IN OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE...BUT THE OVERALL AVG WILL
BE BELOW ADVY AND WILL NOT ISSUE ANYTHING AT THIS TIME.
FINALLY...WITH THE MAIN FORCING AND DEEPER MOISTURE PULLING NE IN
THE AFTN...COULD SEE A PERIOD OF FZDZ. THIS IS DUE TO THE LINGERING
FORCING/MOISTURE BELOW THE ICE CRYSTAL AREA /ISENTROPIC ASCENT ON
275-280K SFCS AND H925-800 MOISTURE/. ADDED THIS TO THE GRIDS IN THE
AFTN FROM SW TO NE AS THE DEEP MOISTURE PULLS OUT...AND MAY BE MOST
PRONOUNCED OVER THE HIGHER TERRAIN NCNTRL...WHERE THE SSE UPSLOPE
FLOW WOULD FAVOR IT.
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG FCST QUESTION FOR MONDAY NIGHT INTO TUESDAY TIME FRAME WILL BE
THE POTENTIAL FOR FZDZ IN THE WAKE OF MONDAYS TROUGH/WARM FRONT.
FCST SNDGS...ESPECIALLY THE NAM BUFR SNDGS...SHOW LINGERING SHALLOW
MOIST LAYER NEAR THE SFC AS DRYING/SUBSIDENCE OCCURS IN MID-LVLS IN
THE WAKE OF THE WARM FRONT. EXPECT LOCATIONS AFFECTED BY AN UPSLOPE
SRLY FLOW WILL BE MOST SUSCEPTIBLE TO PATCHY FZDZ MON NIGHT INTO
TUESDAY MORNING BUT WILL INCLUDE A MENTION FOR MOST OF THE CWA. ANY
LINGERING FZDZ SHOULD TURN TO DZ TUE AFTERNOON AS MOIST LOW-LVLS
WARM ABV FREEZING.
ANOTHER SHORTWAVE AND ASSOC COLD FRONT WILL MOVE THROUGH TUE
AFTERNOON AND TUE NIGHT. TRACK OF THE SHORTWAVE AND THE ASSOC SFC
LOW WOULD FAVOR MAINLY THE NRN TIER FOR SOME LIGHT RAIN OR SNOW AS
THIS IS WHERE MODELS INDICATE DEEPER MOISTURE AND CLOSER PROXIMITY
TO MODERATE Q-VECT CONV AND LIFT ASSOC WITH SHORTWAVE. RAIN/SNOW MIX
ALONG THE NRN TIER SHOULD TURN OVER TO ALL SNOW LATE TUE NIGHT WITH
CAA BEHIND FRONT AND WOULD EXPECT A DIMINISH TREND AS SHORTWAVE/SFC
LOW DEPART QUICKLY EAST.
WEAK RDGG BUILDING IN FROM THE WEST SHOULD RESULT IN MAINLY DRY
CONDITIONS ON WEDNESDAY.
FOR THE EXTENDED /THURSDAY THROUGH SUNDAY/...
MODEL DISAGREEMENTS WILL CONTINUE THROUGHOUT THE REMAINDER OF THE
FORECAST PERIOD PERTAINING TO THE LOCATION AND TIMING OF SHORTWAVES
AFFECTING THE AREA...SO HAVE NOT DIVERGED MUCH FROM CONSENSUS THIS
FAR OUT. MODELS ARE IN FAIRLY GOOD AGREEMENT...HOWEVER...THAT STRONG
RIDGING OFF THE PACIFIC NORTHWEST WEDNESDAY NIGHT/THURSDAY MORNING
WILL ALLOW THE JET STREAM TO TRANSITION TO A MERIDIONAL FLOW ON THE
DESCENDING BRANCH...CREATING AN ENHANCED TROUGHING PATTERN OVER THE
CENTRAL CONUS. GFS IS THE MOST PROGRESSIVE OF THE MODELS...KEEPING
THE TROUGH PLACEMENT FARTHER NORTH AND HAVING IT MOVE EAST MORE
QUICKLY THAN ECMWF/GEM. AS HIGH PRESSURE CONTINUES TO BUILD IN WEST
THROUGH SUNDAY...DESCENDING BRANCH OF TROUGH WILL BEGIN TO
RETROGRADE AND BECOME POSITIVELY TILTED.
TRANSLATING THIS TO THE UPPER GREAT LAKES REGION...OVERALL...THIS
WILL CREATE A FAIRLY BENIGN SYNOPTIC WEATHER PATTERN AS MUCH OF THE
SHORTWAVES WILL PASS TO OUR SOUTH TRAVERSING THE DESCENDING EDGE OF
THE TROUGH. HOWEVER...IF THE MORE NORTHERN PLACEMENT OF THE GFS PANS
OUT...AS THE TROUGH BECOMES POSITIVELY TILTED OVER THE UPPER GREAT
LAKES ON FRIDAY...EXPECT SHORTWAVE TO DEVELOP AND TRAVERSE THE AREA.
THIS WILL BRING THE BEST CHANCE FOR PRECIP DURING THE PERIOD
WITH STRONG QVECTOR CONVERGENCE AND FAIRLY MOIST PROFILE/STEEP LAPSE
RATES DURING ITS PASSAGE. THE ECMWF AND THE GEM ON THE OTHER HAND
HAVE THIS SYSTEM DEVELOPING MUCH FARTHER SOUTH AND THEREBY NOT
IMPACTING THE FORECAST PERIOD AT ALL...SO DIDN`T GO ANY HIGHER THAN
SLIGHT CHANCES. OTHERWISE...PREDOMINATE W AND SW WINDS ALOFT AHEAD
OF DESCENDING JET WILL KEEP TEMPERATURES WELL ABOVE NORMAL THURSDAY.
WITH LOW CONFIDENCE ON PLACEMENT AND STRENGTH OF JET AS IT NEARS THE
AREA...WILL KEEP WITH THE LOWERING TREND OF TEMPS AS WINDS TURN MORE
NORTHERLY BY THE END OF THE PERIOD...BUT MAGNITUDE OF THIS COLD AIR
INTRUSION IS YET TO BE DETERMINED. IF THE MORE AMPLIFIED TROF AND
COLDER SOLN OF THE ECMWF SOLUTION VERIFIES...THEN TEMPS WILL
PROBABLY NEED TO BE LOWERED AND POPS MAY NEED TO BE INCREASED FOR
NEXT WEEKEND FOR AREAS DOWNWIND OF LAKE SUPERIOR IN N-NW FLOW.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
LES WILL DIMINISH AT ALL OF THE TAF SITES THROUGH THE AFTERNOON AND
LEAD TO IMPROVING CONDITIONS...TOWARDS VFR. THE SITE THAT MAY BOUNCE
BETWEEN VFR/MVFR THROUGH THE AFTN INTO THE OVERNIGHT HOURS IS
KCMX...DUE TO WINDS BACKING TO A FAVORABLE WRLY DIRECTION. THIS WILL
LIKELY LEAD TO ANOTHER PERIOD OF LOWER VSBYS TOWARDS MIDNIGHT.
ATTENTION THEN TURNS TO WARM FRONT APPROACHING THE AREA LATE TONIGHT
INTO MON. SNOW AHEAD OF THIS FRONT WILL SPREAD FROM SW TO NE ACROSS
UPPER MI...IMPACTING KIWD BEFORE DAY BREAK AND KSAW/KCMX MID-LATE
MORNING. SHOULD SEE VSBYS DROPPING TO ALT LANDING MINS AS THIS SNOW
MOVES INTO THE AREA...ESPECIALLY AT KIWD.
&&
.MARINE /FOR THE 4PM LAKE SUPERIOR FORECAST ISSUANCE/...
HIGH PRESSURE RIDGE SHIFTING OVER LAKE SUPERIOR TONIGHT WILL BRING
DECREASING WINDS TONIGHT...BELOW 20KTS. A CLIPPER SYSTEM DEVELOPING
IN ALBERTA WILL BEGIN TO MOVE INTO THE NORTHERN PLAINS ON MONDAY
AFTERNOON AND EVENING BEFORE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY NIGHT. SOUTHERLY WINDS AHEAD OF THIS SYSTEM COULD PRODUCE
GUSTS TO 30KTS OVER THE ERN LK ON MONDAY AFTN AND EVENING. THE LOW
WILL SHIFT E ON WED...ALLOWING WEAK HIGH PRESSURE TO BUILD OVER THE
UPPER GREAT LAKES THROUGH THURS. A LOW PRESSURE SYSTEM WILL MOVE
THROUGH THE OHIO RIVER VALLEY ON FRI...BUT SHOULD HAVE LIMITED
EFFECTS ON LK SUPERIOR. EXPECT WINDS TO BE BELOW 25KTS FROM TUESDAY
MORNING THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ006-
007-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
EXTENDED...JMW
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1252 PM EST SUN JAN 29 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...(415 AM EST SUN JAN 29 2012)
ANOTHER WAVE OF LOW PRESSURE WILL ZIP BY THE AREA THIS MORNING...AND
WILL BRING ANOTHER ROUND OF SNOW TO THE AREA. THE HIGHEST
ACCUMULATIONS WILL BE ACROSS THE SOUTHWEST CORNER OF THE AREA...
INCLUDING ALLEGAN...HASTINGS...AND KALAMAZOO. 2 TO LOCALLY 4 INCHES
OF ADDITIONAL ACCUMULATION IS LIKELY FOR THESE AREAS WILL LESS
ELSEWHERE. A BRIEF BREAK IN THE WEATHER IS EXPECTED TONIGHT...BEFORE
A FRONT MOVES IN ACROSS THE AREA ON MONDAY. THIS WILL INITIALLY
BRING LIGHT SNOW TO THE AREA...WITH IT CHANGING OVER TO RAIN BY
MONDAY EVENING. MUCH WARMER TEMPERATURES IN THE 40S CAN BE EXPECTED
BY TUESDAY.
&&
.SHORT TERM...(852 AM EST SUN JAN 29 2012)
(TODAY THROUGH TUESDAY)
THE WINTER WEATHER ADVISORY IS ON TRACK.
BASED ON THE LATEST IR AND WATER VAPOR LOOPS PLUS OUR RADAR MOSAIC
WITH CONSIDERATION TO THE 10Z HRRR IT SEEMS THE HEAVIEST SNOWFALL IN
THE NEXT THREE HOURS (TILL NOON) WILL BE OVER OTTAWA...SOUTHERN
KENT...NORTHERN ALLEGAN AND BARRY COUNTIES AS THAT IS WERE THE
DEFORMATION BAND SEEMS TO BE SETTING UP. BASED ON THIS THE ADVISORY
AS IT IS SEEMS FINE. I WOULD EXPECT SNOWFALL RATES OF UP TO AN INCH
AN HOUR IN THOSE FOUR COUNTIES.
REST OF THE EARLIER DISCUSSION...WE SHOULD SEE THE SYSTEM IN THE
PROCESS OF MOVING EAST OF THE AREA AT 18Z...AND IT SHOULD BE GONE BY
21Z. W/NW FLOW WILL HOLD IN AND DELTA T/S WILL REMAIN IN THE MID
TEENS. THIS WOULD SUPPORT ONGOING LAKE EFFECT WITH ACCUMS. HOWEVER
SUBSIDENCE IN THE WAKE OF THE MORNING WAVE WILL LOWER INVERSION
HEIGHTS TO AROUND 3K FT ALONG WITH THE UPPER FLOW EXPECTED TO BE
TRANSITIONING TO ANTI-CYCLONIC. THE LATTER FACTORS MENTIONED LOOK TO
BE SIGNIFICANT ENOUGH TO DIMINISH LAKE EFFECT CHCS LATE THIS
AFTERNOON INTO THE EVENING. THE FLOW WILL TRANSITION FROM W/NW TO SW
BY OVERNIGHT TONIGHT.
AFTER A SHORT BREAK WITH LAKE EFFECT WINDING DOWN...AND SFC RIDGING
MOVING ACROSS TONIGHT...WE WILL SEE PCPN CHCS INCREASE DURING THE
DAY ON MON. THIS OCCURS AS HEIGHTS BUILD...AND AN ELEVATED
BAROCLINIC/FRONTAL ZONE PUSHES TO THE NE AS AN ELEVATED WARM FRONT.
ALL MODELS ARE BREAKING OUT PCPN ALONG THE FRONT ACROSS CENTRAL AND
NRN LOWER MI. THE BETTER CHC OF PCPN WILL BE AS YOU HEAD FURTHER TO
THE NE AS PCPN BECOMES MORE ORGANIZED. PCPN WILL START OUT AS ALL
SNOW THE FIRST PART OF MON. PCPN WILL TRANSITION TO MORE LIQUID THEN
MON AFTERNOON AS WARMER AIR ALOFT MOVES IN...AND WE GET SOME
BOUNDARY LAYER HEATING. WE COULD SEE SOME SLEET MIX IN MON AFTERNOON
AS A SMALL COLD LAYER AROUND 1-3K FT AGL WILL TAKE SHAPE RESULTING
FROM THE SFC HEATING AND THE WAA ALOFT.
THE FRONT MOVES OUT MON EVENING...LEAVING LOWER MICHIGAN DRY UNTIL
TUE AFTERNOON AS WE SEE THE PV ANOMALY/UPPER WAVE APPROACH. PCPN IN
THE FORM OF LIGHT RAIN/SHOWERS WILL DEVELOP TUE AFTERNOON WHEN WE
SEE GOOD WARM AND MOIST ADVECTION AND THE SYNOPTIC FORCING MOVE IN
AHEAD OF THE WAVE.
&&
.LONG TERM...(415 AM EST SUN JAN 29 2012)
(TUESDAY NIGHT THROUGH SATURDAY)
HAVE OPTED TO FOLLOW THE GFS THROUGH THE LONG TERM. THE ECMWF SPINS
UP A SYSTEM AND PUSHES SIGNIFICANT PRECIPITATION INTO THE SOUTHERN
GREAT LAKES ON THURSDAY. THE PMDHMD DISCUSSION FROM HPC FAVORS THE
GFS AT 84 HOURS EXPLAINING THAT THE ECMWF AS AN OUTLIER. WITH THIS
IN MIND...THE GFS HAS A FAIRLY BENIGN LONG TERM PERIOD.
A COLD FRONT SLIDES EAST ACROSS LOWER MICHIGAN TUESDAY NIGHT WITH
RAIN. 850MB TEMPERATURES APPEAR WARM ENOUGH FOR MAINLY RAIN BEFORE
THE PRECIPITATION SHUTS OFF ALONG THE FRONT OVERNIGHT.
BEYOND TUESDAY NIGHT...HAVE A DRY FORECAST WEDNESDAY THROUGH
SATURDAY. FAIRLY TOUGH TO HAVE A DRY FORECAST THIS TIME OF YEAR IN
THE MID LATITUDES...BUT NOTHING SIGNIFICANT ENOUGH TO INCLUDE IN THE
FORECAST AT THIS TIME. THE PATTERN ESSENTIALLY IS ZONAL TO BEGIN THE
LONG TERM TRENDING TOWARD AND UPPER TROUGH BY LATE IN THE WEEK.
A WEAK SHORTWAVE ALOFT PASSES THROUGH THE AREA ON THURSDAY...BUT
VERY LIMITED MOISTURE SHOULD KEEP US DRY. ANOTHER SHORTWAVE PASSES
WELL OFF TO OUR SOUTH THURSDAY NIGHT AND FRIDAY AGAIN MISSING THE
AREA WITH PRECIPITATION.
TEMPERATURES THROUGH THE PERIOD WILL BE ABOVE NORMAL WITH HIGHS UP
AROUND 40 DURING THE WEEK. BY SATURDAY...COLDER AIR IS FILTERING IN
WITH THE DEEPENING TROUGH. TEMPS OVER THE WEEKEND LOOK TO BE
TRENDING BACK TOWARD NORMALS.
&&
.AVIATION...(1252 PM EST SUN JAN 29 2012)
IFR/LIFR WAS IMPACTING THE TAF SITES AS OF 1730Z IN MODERATE TO
HEAVY SNOW. SNOWFALL WILL DIMINISH FROM WEST TO EAST OVER THE THREE
HOURS...MOVING OUT OF THE JXN AREA BY 21Z. IMPROVEMENT FROM THE
WEST...BEHIND THE SNOW...WILL BE QUICK WITH VFR CONDITIONS
DEVELOPING WITHIN A COUPLE HOURS AFTER THE SNOW HAS ENDED. VFR IS
EXPECTED TO CONTINUE THROUGH THE OVERNIGHT PERIOD.
ANOTHER AREA OF SNOW IS EXPECTED TO SPREAD INTO THE AREA MONDAY
MORNING. THIS APPEARS TO BE MOST LIKELY ACROSS THE NORTHERN TAF
SITES...ALONG I-96. IFR WILL LIKELY REDEVELOP THERE AFTER 15Z
MONDAY. IFR WILL ALSO BE POSSIBLE ALONG I-94...HOWEVER IT SHOULD BE
SLIGHTLY LATER AND SHOULD BE MORE PATCHY. THE SNOW SHOULD BEGIN TO
SWITCH OVER TO A MIX RAIN/SNOW AFTER 18Z.
&&
.MARINE...(415 AM EST SUN JAN 29 2012)
WE WILL MAINTAIN THE SMALL CRAFT ADVISORY THAT REPLACED THE GALE
WARNING LAST EVENING. WINDS HAVE COME DOWN A FAIR AMOUNT SINCE THE
EVENING UPDATE...AND THE THREAT FOR GALES HAS ENDED. WE MAY DROP
BELOW THE WIND CRITERIA FOR SMALL CRAFT ADVISORIES THIS
AFTERNOON...HOWEVER WAVES WILL REMAIN UP UNTIL THE WINDS INCREASE
AGAIN LATER TODAY. THE SAME THING WILL LIKELY HAPPEN TONIGHT INTO
MONDAY. WE WILL HOLD THE SCA THROUGH 12Z MON...AND THIS WILL MOST
LIKELY NEED TO BE EXTENDED AT SOME POINT.
&&
.HYDROLOGY...(415 AM EST SUN JAN 29 2012)
ONLY POTENTIAL HYDROLOGY ISSUE THIS WEEKEND WOULD BE SOME ICE
DEVELOPMENT/ICE JAMS AS SOMEWHAT COLDER AIR HAS MOVED IN PLACE. THIS
AIR IS NOT SIGNIFICANTLY COLD...AND WE SHOULD NOT DEVELOP A LOT OF
ICE.
THE OTHER ISSUE THAT COULD DEVELOP WOULD BE INCREASING RIVER LEVELS
DUE TO MELTING SNOW WITH THE WARMER TEMPERATURES MOVING IN AND
MELTING SNOW ALONG WITH SOME RAIN. WE DO NOT HAVE A SIGNIFICANT
SNOWPACK IN PLACE...AND WE ARE NOT EXPECTING SIGNIFICANT AMOUNTS OF
RAIN. THIS SHOULD KEEP THE FLOODING POTENTIAL FAIRLY LOW THROUGH MID
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FOR OTTAWA...KENT...IONIA...
ALLEGAN...BARRY...EATON...VAN BUREN...KALAMAZOO AND CALHOUN
COUNTIES.
LM...SMALL CRAFT ADVISORY IN EFFECT THROUGH 7 AM MONDAY FOR THE
ENTIRE NEARSHORE.
&&
$$
SYNOPSIS: NJJ
SHORT TERM: NJJ WDM
LONG TERM: DUKE
AVIATION: JK
MARINE: NJJ
HYDROLOGY: NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
852 AM EST SUN JAN 29 2012
LATEST UPDATE...SHORT TERM...
.SYNOPSIS...(415 AM EST SUN JAN 29 2012)
ANOTHER WAVE OF LOW PRESSURE WILL ZIP BY THE AREA THIS MORNING...AND
WILL BRING ANOTHER ROUND OF SNOW TO THE AREA. THE HIGHEST
ACCUMULATIONS WILL BE ACROSS THE SOUTHWEST CORNER OF THE AREA...
INCLUDING ALLEGAN...HASTINGS...AND KALAMAZOO. 2 TO LOCALLY 4 INCHES
OF ADDITIONAL ACCUMULATION IS LIKELY FOR THESE AREAS WILL LESS
ELSEWHERE. A BRIEF BREAK IN THE WEATHER IS EXPECTED TONIGHT...BEFORE
A FRONT MOVES IN ACROSS THE AREA ON MONDAY. THIS WILL INITIALLY
BRING LIGHT SNOW TO THE AREA...WITH IT CHANGING OVER TO RAIN BY
MONDAY EVENING. MUCH WARMER TEMPERATURES IN THE 40S CAN BE EXPECTED
BY TUESDAY.
&&
.SHORT TERM...(852 AM EST SUN JAN 29 2012)
(TODAY THROUGH TUESDAY)
THE WINTER WEATHER ADVISORY IS ON TRACK.
BASED ON THE LATEST IR AND WATER VAPOR LOOPS PLUS OUR RADAR MOSAIC
WITH CONSIDERATION TO THE 10Z HRRR IT SEEMS THE HEAVIEST SNOWFALL IN
THE NEXT THREE HOURS (TILL NOON) WILL BE OVER OTTAWA...SOUTHERN
KENT...NORTHERN ALLEGAN AND BARRY COUNTIES AS THAT IS WERE THE
DEFORMATION BAND SEEMS TO BE SETTING UP. BASED ON THIS THE ADVISORY
AS IT IS SEEMS FINE. I WOULD EXPECT SNOWFALL RATES OF UP TO AN INCH
AN HOUR IN THOSE FOUR COUNTIES.
REST OF THE EARLIER DISCUSSION...WE SHOULD SEE THE SYSTEM IN THE
PROCESS OF MOVING EAST OF THE AREA AT 18Z...AND IT SHOULD BE GONE BY
21Z. W/NW FLOW WILL HOLD IN AND DELTA T/S WILL REMAIN IN THE MID
TEENS. THIS WOULD SUPPORT ONGOING LAKE EFFECT WITH ACCUMS. HOWEVER
SUBSIDENCE IN THE WAKE OF THE MORNING WAVE WILL LOWER INVERSION
HEIGHTS TO AROUND 3K FT ALONG WITH THE UPPER FLOW EXPECTED TO BE
TRANSITIONING TO ANTI-CYCLONIC. THE LATTER FACTORS MENTIONED LOOK TO
BE SIGNIFICANT ENOUGH TO DIMINISH LAKE EFFECT CHCS LATE THIS
AFTERNOON INTO THE EVENING. THE FLOW WILL TRANSITION FROM W/NW TO SW
BY OVERNIGHT TONIGHT.
AFTER A SHORT BREAK WITH LAKE EFFECT WINDING DOWN...AND SFC RIDGING
MOVING ACROSS TONIGHT...WE WILL SEE PCPN CHCS INCREASE DURING THE
DAY ON MON. THIS OCCURS AS HEIGHTS BUILD...AND AN ELEVATED
BAROCLINIC/FRONTAL ZONE PUSHES TO THE NE AS AN ELEVATED WARM FRONT.
ALL MODELS ARE BREAKING OUT PCPN ALONG THE FRONT ACROSS CENTRAL AND
NRN LOWER MI. THE BETTER CHC OF PCPN WILL BE AS YOU HEAD FURTHER TO
THE NE AS PCPN BECOMES MORE ORGANIZED. PCPN WILL START OUT AS ALL
SNOW THE FIRST PART OF MON. PCPN WILL TRANSITION TO MORE LIQUID THEN
MON AFTERNOON AS WARMER AIR ALOFT MOVES IN...AND WE GET SOME
BOUNDARY LAYER HEATING. WE COULD SEE SOME SLEET MIX IN MON AFTERNOON
AS A SMALL COLD LAYER AROUND 1-3K FT AGL WILL TAKE SHAPE RESULTING
FROM THE SFC HEATING AND THE WAA ALOFT.
THE FRONT MOVES OUT MON EVENING...LEAVING LOWER MICHIGAN DRY UNTIL
TUE AFTERNOON AS WE SEE THE PV ANOMALY/UPPER WAVE APPROACH. PCPN IN
THE FORM OF LIGHT RAIN/SHOWERS WILL DEVELOP TUE AFTERNOON WHEN WE
SEE GOOD WARM AND MOIST ADVECTION AND THE SYNOPTIC FORCING MOVE IN
AHEAD OF THE WAVE.
&&
.LONG TERM...(415 AM EST SUN JAN 29 2012)
(TUESDAY NIGHT THROUGH SATURDAY)
HAVE OPTED TO FOLLOW THE GFS THROUGH THE LONG TERM. THE ECMWF SPINS
UP A SYSTEM AND PUSHES SIGNIFICANT PRECIPITATION INTO THE SOUTHERN
GREAT LAKES ON THURSDAY. THE PMDHMD DISCUSSION FROM HPC FAVORS THE
GFS AT 84 HOURS EXPLAINING THAT THE ECMWF AS AN OUTLIER. WITH THIS
IN MIND...THE GFS HAS A FAIRLY BENIGN LONG TERM PERIOD.
A COLD FRONT SLIDES EAST ACROSS LOWER MICHIGAN TUESDAY NIGHT WITH
RAIN. 850MB TEMPERATURES APPEAR WARM ENOUGH FOR MAINLY RAIN BEFORE
THE PRECIPITATION SHUTS OFF ALONG THE FRONT OVERNIGHT.
BEYOND TUESDAY NIGHT...HAVE A DRY FORECAST WEDNESDAY THROUGH
SATURDAY. FAIRLY TOUGH TO HAVE A DRY FORECAST THIS TIME OF YEAR IN
THE MID LATITUDES...BUT NOTHING SIGNIFICANT ENOUGH TO INCLUDE IN THE
FORECAST AT THIS TIME. THE PATTERN ESSENTIALLY IS ZONAL TO BEGIN THE
LONG TERM TRENDING TOWARD AND UPPER TROUGH BY LATE IN THE WEEK.
A WEAK SHORTWAVE ALOFT PASSES THROUGH THE AREA ON THURSDAY...BUT
VERY LIMITED MOISTURE SHOULD KEEP US DRY. ANOTHER SHORTWAVE PASSES
WELL OFF TO OUR SOUTH THURSDAY NIGHT AND FRIDAY AGAIN MISSING THE
AREA WITH PRECIPITATION.
TEMPERATURES THROUGH THE PERIOD WILL BE ABOVE NORMAL WITH HIGHS UP
AROUND 40 DURING THE WEEK. BY SATURDAY...COLDER AIR IS FILTERING IN
WITH THE DEEPENING TROUGH. TEMPS OVER THE WEEKEND LOOK TO BE
TRENDING BACK TOWARD NORMALS.
&&
.AVIATION...(650 AM EST SUN JAN 29 2012)
COMPACT UPPER DISTURBANCE WILL SWING ACROSS THE TAF SITES THIS
MORNING BRINGING WITH IT SNOW. THE SNOW WILL GET A BOOST FROM LAKE
MICHIGAN AS WELL. CONDITIONS WILL TREND DOWN RAPIDLY THIS MORNING AS
THE PRECIPITATION MOVES ON SHORE. EXPECTING MODERATE TO OCCASIONALLY
HEAVY SNOW AT THE TAF SITES BETWEEN 13Z AND 21Z. KMKG...KGRR AND
KAZO WILL BE MOST IMPACTED. VFR CONDITIONS ARE IN PLACE AT MOST
SITES ACROSS THE AREA AT 12Z. BY MID MORNING MVFR WILL HAVE MOVED
IN...WITH A TREND TOWARD IFR...ESPECIALLY VISIBILITIES.
THIS AFTERNOON AND EVENING...VISIBILITIES AND CEILINGS WILL
IMPROVE...TO AT LEAST MVFR IF NOT VFR. EXPECT 2500-3500FT CEILINGS
AND FLURRIES FOR MUCH OF THIS EVENING AND TONIGHT.
&&
.MARINE...(415 AM EST SUN JAN 29 2012)
WE WILL MAINTAIN THE SMALL CRAFT ADVISORY THAT REPLACED THE GALE
WARNING LAST EVENING. WINDS HAVE COME DOWN A FAIR AMOUNT SINCE THE
EVENING UPDATE...AND THE THREAT FOR GALES HAS ENDED. WE MAY DROP
BELOW THE WIND CRITERIA FOR SMALL CRAFT ADVISORIES THIS
AFTERNOON...HOWEVER WAVES WILL REMAIN UP UNTIL THE WINDS INCREASE
AGAIN LATER TODAY. THE SAME THING WILL LIKELY HAPPEN TONIGHT INTO
MONDAY. WE WILL HOLD THE SCA THROUGH 12Z MON...AND THIS WILL MOST
LIKELY NEED TO BE EXTENDED AT SOME POINT.
&&
.HYDROLOGY...(415 AM EST SUN JAN 29 2012)
ONLY POTENTIAL HYDROLOGY ISSUE THIS WEEKEND WOULD BE SOME ICE
DEVELOPMENT/ICE JAMS AS SOMEWHAT COLDER AIR HAS MOVED IN PLACE. THIS
AIR IS NOT SIGNIFICANTLY COLD...AND WE SHOULD NOT DEVELOP A LOT OF
ICE.
THE OTHER ISSUE THAT COULD DEVELOP WOULD BE INCREASING RIVER LEVELS
DUE TO MELTING SNOW WITH THE WARMER TEMPERATURES MOVING IN AND
MELTING SNOW ALONG WITH SOME RAIN. WE DO NOT HAVE A SIGNIFICANT
SNOWPACK IN PLACE...AND WE ARE NOT EXPECTING SIGNIFICANT AMOUNTS OF
RAIN. THIS SHOULD KEEP THE FLOODING POTENTIAL FAIRLY LOW THROUGH MID
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FOR OTTAWA...KENT...IONIA...
ALLEGAN...BARRY...EATON...VAN BUREN...KALAMAZOO AND CALHOUN
COUNTIES.
LM...SMALL CRAFT ADVISORY IN EFFECT THROUGH 7 AM MONDAY FOR THE
ENTIRE NEARSHORE.
&&
$$
SYNOPSIS: NJJ
SHORT TERM: NJJ WDM
LONG TERM: DUKE
AVIATION: DUKE
MARINE: NJJ
HYDROLOGY: NJJ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
339 PM CST SUN JAN 29 2012
.DISCUSSION...
ANOTHER MILD WEEK IS AHEAD OF US...WITH HIGHS IN THE MID 30S TO
LOWER 40S COMING FOR MONDAY THROUGH THURSDAY. IMPRESSIVE WARM
FRONT COMING THROUGH TONIGHT WILL BRING ABOUT THE CHANCE FOR
ANOTHER DUSTING OF SNOW...WHILE A LOW PASSING ACROSS NRN MN
TUESDAY MAY BRING SOME LIGHT PRECIP TO NRN SECTIONS OF THE CWA.
AFTER THAT...THE REST OF THE FORECAST IS DRY...WITH ONLY A MODEST
COOL DOWN EXPECTED FOR THE WEEKEND.
STRONG WARM FRONT THIS AFTERNOON STRETCHES FROM KC TO NE MONTANA.
TO GO ALONG WITH THIS...UPPER RIDGE IS WORKING INTO THE
PLAINS...WITH THE RUC SWINGING 160M 12 HR H5 HEIGHT RISES ACROSS
THE AREA THIS AFTERNOON. COMBINATION OF A SHORTWAVE MOVING INTO
MT...ALONG WITH STRONG ISENTROPIC/FGEN FORCING TO THE NORTH OF THE
FRONT HAS RESULTED IN THE GENERATION OF A NICE BAND OF SNOW ACROSS
NODAK. SHORT TERM HI RES GUIDANCE ALL SIMILAR WITH THIS BAND OF
SNOW REACHING THE NW CWA BETWEEN 2Z AND 4Z AND QUICKLY WORKING
EAST THROUGH THE NIGHT...EXITING THE WI CWA AROUND 15Z MON
MORNING. ONE ISSUE TO WATCH FOR TONIGHT IS A DRY LAYER OF AIR THAT
IS DEVELOPING THIS AFTERNOON BETWEEN H9 AND H7. INDICATIONS FROM
BUFKIT SOUNDINGS IS THAT WE WILL BE MOISTENING THIS LAYER FROM
TOP-DOWN...SO MUCH OF THE SNOW MAY BE LOST TO SUBLIMATION. ARW
1 KM AGL REFLECTIVITY FORECASTS ARE SPOTTY/NON-EXISTENT ACROSS
MUCH OF THE MPX CWA...AND THIS DRY LAYER LIKELY HAS A LOT TO DO
WITH IT. STILL...SREF PROBS ARE UP OVER 80 PERCENT FROM CENTRAL MN
INTO WRN WI...WHICH MATCHES UP WELL WITH BEST THALER QG FORCING.
THEREFORE...HAVE CATEGORICAL POPS ALONG AND NORTH OF AN
AXN/STC/EAU LINE FOR TONIGHT...WHERE FORCING AND MOISTURE LOOK
MOST LIKELY TO COINCIDE. CERTAINLY LOOKING GRIM FOR ANYONE ALONG
AND SOUTH OF THE MN RIVER TO SEE MUCH PRECIP. AS FOR
P-TYPE...STILL SEEING A SIGNIFICANT WARM NOSE COMING IN WITH THE
WARM FRONT...BUT MODELS CONTINUE TO SHOW THE PRECIP REMAINING OUT
AHEAD OF THE WARM NOSE...WITH ONLY AN HOUR OR TWO OF A WINTRY MIX
POSSIBLE AS THE PRECIP PULLS OUT. LOOKS TO BE YET ANOTHER SYSTEM
THIS YEAR THAT LAYS DOWN A QUICK HALF INCH TO AN INCH WHERE
CATEGORICAL POPS ARE LOCATED.
BESIDE THE PRECIP COMING IN...ALL GUIDANCE SIMILAR WITH A NON-
DIURNAL TREND FOR TONIGHT...WITH HIGHS STEADILY RISING THROUGH THE
NIGHT. IN FACT...GFSLAMP HAS ABOUT 10 DEGREES OF WARMING FOR ALL
MN LOCATIONS THROUGH THE NIGHT. EVEN IN WI...TEMPS SHOULD ONLY
FALL THROUGH ABOUT 3Z BEFORE GOING STEADY AND THEN RISING.
BIG QUESTION FOR MONDAY IS WHERE DOES THE WARM FRONT SET UP. 12Z
GUIDANCE HAS THE FRONT SOMEWHERE BETWEEN I-94 AND A HINCKLEY TO
FARGO LINE AT 6PM MONDAY. THIS WILL LEAD TO SOME UNCERTAINTY FOR
HIGHS ON MONDAY...AS AREAS SOUTH OF THE WARM FRONT WILL LIKELY
MAKE A RUN INTO THE 40S...WHILE AREAS ALONG AND NORTH REMAIN
CLOUDY WITH HIGHS LIKELY ONLY TOPPING OUT AROUND FREEZING. IN
ADDITION...THERE IS SOME CONCERN FOR DRIZZLE NORTH OF THE FRONT
GIVEN THE AMOUNT OF LOW LEVEL MOISTURE EXPECTED. HOWEVER...NAM/GFS
BUFKIT SOUNDINGS OVER CENTRAL MN SHOW A SHALLOW MIXED BOUNDARY
LAYER DEVELOPING DURING THE AFTERNOON...WITH A BIT OF A TEMP/DEWP
SPREAD NOTED ON THE SOUNDINGS. BECAUSE OF THIS...NOT TOO CONFIDENT
THAT WE WILL SEE THAT MUCH DZ GENERATION ACROSS CENTRAL
MN...DESPITE PERSISTENT LIFT ALONG THE FRONT. OTHER VARIABLE TO
CONTEND WITH FOR TEMPS ON MONDAY WILL BE SNOW COVER. SATELLITE
IMAGES THIS MORNING SHOWED MOST OF YELLOW MEDICINE AND LAC QUI
PARLE COUNTIES ARE SNOW FREE...AND GIVEN FAVORABLE WSW FLOW ON
MONDAY...PLACES SUCH AS MADISON AND MONTEVIDEO COULD SEE HIGHS TOP
OUT IN THE LOW 50S. SOUTH CENTRAL MN HAS THE OPPOSITE PROBLEM...AS
COOP OBSERVES THIS MORNING REPORTED 3 TO 5 INCHES OF SNOW ON THE
GROUND DOWN THERE...THIS MAY RESULT IN HIGHS BEING A BIT OVER DONE
DOWN THERE. AT ANY RATE...A BLEND OF THE MET/MAV BIAS CORRECTED
DATA WAS USED FOR HIGHS TOMORROW.
THE MILD CONDITIONS WILL REMAIN IN PLACE MONDAY NIGHT THROUGH
THURSDAY. MODELS SWING A COLD FRONT ACROSS THE AREA TUESDAY
MORNING...WITH LOWS IN THE WARM SECTOR OUT AHEAD OF IT MONDAY
NIGHT LIKELY STRUGGLING TO FALL BELOW FREEZING. H85 TEMPS LOOKS TO
ONLY GET KNOCKED DOWN TO AROUND 0C BEHIND THE FRONT...WITH HIGHS
TUESDAY THROUGH THURSDAY LOOKING TO BE A DEGREE OR TWO COLDER THAN
THE PREVIOUS DAY. IN FACT...OVERNIGHT LOWS LOOK TO ONLY FALL BACK
TO AROUND THE AVERAGE HIGHS FOR THIS TIME OF YEAR. BY THE TIME
JANUARY IS ALL SAID AND DONE...SHOULD HAVE AN AVERAGE TEMPERATURE
DEPARTURE AT MSP SOMEWHERE IN THE NEIGHBORHOOD OF 8 DEGREES...WITH
JANUARY OF 2012 POSSIBLY REPLACING JANUARY OF 1933 AS 8TH WARMEST
ALL TIME /23.1 WAS THE AVE TEMP FOR JAN OF 1933/.
ONLY OTHER CHANCE FOR PRECIP LOOKS TO COME LATE MONDAY NIGHT INTO
TUESDAY AS A SFC LOW TRACKS ACROSS NRN MN. UNFORTUNATELY...THIS
LOW AND ITS ASSOCIATED COLD FRONT WILL BE ENCOUNTERING QUITE A BIT
OF DRY AIR OVER THE MPX CWA...WITH BEST PRECIP SIGNAL BEING UP
ACROSS NRN MN. STILL...SLIGHT SOUTHWARD SHIFT IN MODELS THIS
MORNING PROMPTED AN INTRODUCTION FOR SOME SLIGHT CHANCE POPS
ACROSS FAR NRN CWA LATE MONDAY NIGHT THAT LAST THROUGH THE DAY ON
TUESDAY. AN PRECIP AMOUNTS LOOK LIGHT...WITH P-TYPE BEING A RA/SN
MIX INTO TUESDAY MORNING THAT TRANSITIONS TO MAINLY RA DURING THE
DAY.
AS WE END THE WEEK...THE BIG STORY HERE WILL BE THE SIGNIFICANT
PATTERN SHIFT THE MEDIUM RANGE MODELS ARE SHOWING GOING INTO THE
WEEKEND. OUR CURRENT FAST WNW FLOW LOOKS TO BECOME MORE AMPLIFIED
BY THE WEEKEND...WITH A STRONG UPPER RIDGE DEVELOPING OVER WRN
NOAM AND THE PATTERN RESEMBLING MORE A LA NINA SITUATION FOR
ONCE. THOUGH THIS DOES OPEN US UP TO N/NW FLOW THIS WEEKEND...THE
ASSOCIATED COOL DOWN LOOKS TO ONLY TAKE ABOUT 10 DEGREES OFF OF
HIGHS...WITH READINGS GOING FROM 15 TO 20 DEGREES ABOVE NORMAL BACK
DOWN TO 5 TO 10 DEGREES ABOVE NORMAL. THERE ARE NO INDICATIONS OF
SIGNIFICANT COLD AIR SHOWING UP UNTIL THE SECOND WEEK OF
FEB...WHEN BOTH THE GFS/ECMWF SHOW A POLAR VORTEX SHOWING UP OVER
SRN HUDSON BAY. EVEN THEN THOUGH...MN LOOKS TO BE ON THE BOUNDARY
BETWEEN THE ARCTIC AIR TO THE EAST AND THE MILD PACIFIC AIR TO THE
WEST.
&&
.AVIATION.../18Z TAF ISSUANCE/
SHORT TERM CONCERNS... OR THRU 00Z DEPENDS UPON MVFR CLDS ACROSS
SW MN...AND IF THEY CONTINUE TO DEVELOP ACROSS SW...INTO SC MN
THIS AFTN WHICH WOULD BRING SOME MVFR CIGS TO RWF...AND POSSIBLY
AS FAR EAST AT MSP. AFT 00Z...AVIATION CONCERNS SHIFT TO THE WARM
FRONT MOVING ACROSS THE DAKOTAS THIS MORNING...AND HOW
PRECIPITATION SPREADS EASTWARD AND HOW LOW CIGS/VSBYS BECOME AS
LOW LEVELS SATURATE THIS EVENING.
TIMING OF THE -SN REMAINS CLOSE TO PREVIOUS TAFS WITH AXN ARND
00-01Z...WITH THE HEAVIEST BETWEEN 2-6Z. CIGS WILL TEMPO LOWER TO
LOW END MVFR WITH VSBYS ARND 1-2SM. RWF WILL LIKELY BE ON THE EDGE
OF THE SATURATED DENDRITIC ZONE WHICH WILL KEEP ANY TYPE OF VSBY
RESTRICTIONS TO A MINIMUM. CIGS COULD BRIEF LOWER TO MVFR IF
HEAVIER SN DEVELOPS. STC WILL BE SIMILAR TO AXN WITH TIMING OFF BY
1-2 HRS. RNH/EAU WILL LIKELY NOT SEE ANY TYPE OF RESTRICTIONS TO
VSBY UNTIL AFT 6Z WHICH WILL ALLOW FOR ONE MORE TAF PERIOD BEFORE
ANY TYPE OF SIGNIFICANT CHGS. WNDS WILL SHIFT TO THE SW/S THIS
AFTN FROM WEST TO EAST...WITH S/SE THIS EVENING WITH GUSTS OF 18
TO 22 KTS IN THE TYPICAL AREAS OF RWF/AXN/STC. WNDS SHOULD BECOME
TO DECREASE AFT MIDNIGHT...WITH MORE SW WNDS BY 12Z.
MSP...AS PREVIOUSLY STATED...MVFR CIGS ASSOCIATED WITH MOISTURE
ACROSS SW MN WILL BE LIMITED AS IT MOVES TO THE NE AS WNDS SHIFT
TO THE SW THIS AFTN. WILL ONLY ADVERTISE FEW025 ATTM BASED ON
CURRENT SATELLITE TRENDS. TIMING WHEN -SN STARTS IS SIMILAR TO
PREVIOUS TAFS...WITH THE HEAVIEST ACTIVITY LIKELY BETWEEN 4-7Z.
CIGS/VSBYS WILL LOWER AS -SN DEVELOPS. DENDRITIC ZONE WHERE THE
BEST LIFT OCCURS WILL BE BRIEF...AND WILL LIKELY END ABRUPTLY AFT
6Z. HOWEVER...THERE REMAINS SOME LIFT AFT 6Z WITH PRECIPITATION
TYPE A CONCERN. WILL INTRODUCE PL AT THIS TIME...BUT IT COULD BE
MORE -FZDZ/-FZRA DUE TO THE DEPTH OF THE WARM LAYER MOVING IN
RAPIDLY THIS EVENING. AFT 12-15Z/30...VFR CONDITIONS SHOULD
PREVAIL WITH WNDS BECOMING MORE S/SW UNDER 8 KTS.
.TUE...VFR.
.WED...MVFR/PRECIPITATION POSSIBLE.
.THU...VFR.
..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/JLT
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
321 PM CST SUN JAN 29 2012
.DISCUSSION...
Short Term (Tonight through Tuesday Night)...
Near record warmth and fire weather concerns Monday remain the short
term weather highlights.
Recent satellite imagery shows the bulk of mid-high cloud cover
already beginning to shift north as upper flow begins to flatten
under the influence of weak upstream ridging. More prevalent
sunshine has allowed temperatures to reach the 50 degree mark yet
again, with the exception of far northeast Missouri where light snow
cover has kept readings in the upper 30s.
A dramatic increase in lower tropospheric temperatures will continue
through tonight as westerly winds spread across the Plains. With
cloud cover now expected to be a non-issue on Monday, the potential
for near-record highs looks much more certain. Have nudged up maxes
another degree or two, and given 925mb temp progs would not be
surprised to see a few isolated upper 60s given the favored
southwest surface winds. The record of 68 at Kansas City is one of
the longest standing records left (set in 1890) to this would be
quite a feat.
Dewpoint forecast remains the most challenging, with models having
grossly overforecast dewpoints on day 1 of nearly every warm spell
this season. Current surface analysis shows 30F+ dewpoints
restricted to Deep South Texas, with offshore or shore-parallel flow
prevailing across the western Gulf. Simply put, with -10 to -20C
dewpoints atop the boundary layer, models are simply off their
rockers with upper 30s to lower 40F dewpoints advecting into the
area tomorrow, especially given the continental wind
vectors...nevermind vertical mixing. Have made dramatic cuts to
dewpoints tomorrow with modified Gulf return not anticipated until
later Monday night. Given ambient conditions and mixing potential,
these cuts may still not be enough, and thus the potential for RH
values to plummet to near 20%. Therefore, went ahead with a fire
weather watch for tomorrow afternoon for all but northeast Missouri.
Should my hunch be correct, would expect a red flag warning to be
posted tonight.
Otherwise, moisture will begin to surge into the area ahead of a
weak front later Monday night, accompanied by a rapidly broadening
expanse of stratus. Low clouds, drizzle and fog will likely restrict
warming into the day Tuesday, and the current forecast looked
reasonable in these aspects. Clearing should take place from the
northwest Tuesday night, but with high pressure spilling off the
Colorado Rockies and a weak pressure gradient, the cool down will be
modest at best.
Bookbinder
Medium Range (Wednesday - Sunday):
Confidence in regards to the extended forecast remains low as models
are still struggling with the timing/location/intensity of a pattern
change from quasi-zonal to very meridional flow. There is general
agreement that a ridge will begin to build across the eastern
Pacific later this week and spread eastward into the western CONUS
Thursday into Friday. The response to this ridging is for troughing
to develop across the eastern half to two-thirds of the CONUS. And
this is where models are struggling, both run to run and amongst
themselves and their ensembles. By Friday, ensemble standard
deviation really increases across the region with values approaching
10 decameters and there could be a closed low anywhere from roughly
the Four Corners area to the Great Lakes. Given the huge uncertainty
for this period did not deviate much from the forecast
initialization. One minor change was to reduce precipitation chances
as confidence is just not high enough to justify mentioning a chance
of anything at this time. Also, even though there is poor agreement
regarding the details of the Eastern CONUS troughing there is
general agreement that the area should remain in or be close to the
cyclonic flow aloft which favors a cooling trend and we should be
more likely to see temperatures closer to normal heading into the
weekend.
CDB
&&
.CLIMATE...
Record high temperatures for January 30:
Kansas City...68 set in 1890
St. Joseph....64 set in 1988
&&
.AVIATION...
Blanket of mid cloud cover not handled well by all but the RUC model
has continued to spread southeast, topped by additional
cirro-stratus further upstream. Broken cloud cover should persist
through early evening, affecting mainly MCI/STJ with an overall
dissipating trend as the moisture is gradually shunted north and
east between 10-25kft.
Otherwise, light/variable flow will continue this afternoon, with a
trend toward light southeast and then south winds overnight. Winds
should finally settle around to the southwest before daybreak with
an increase in speed to 10-12 knots by mid morning.
In concert with strong warm advection tonight, better flow develops
aloft after midnight, but the vertical shear progs and degree of
boundary layer mixing later tonight lead me to believe that low
level wind shear will not be a major concern at this time. Certainly
if the near surface winds do not return as expected, then LLWS may
need to be included for the 00Z TAFs.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...FIRE WEATHER WATCH MONDAY AFTERNOON FOR MOZ001>005-011>015-
020>023-028>031-037>039-043>046-053-054.
KS...FIRE WEATHER WATCH MONDAY AFTERNOON FOR KSZ025-057-060-102>105.
&&
$$
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1121 AM CST SUN JAN 29 2012
...UPDATED AVIATION...
.DISCUSSION...
Water vapor imagery shows a subtle short wave tracking across the
Upper Midwest early this morning. Any appreciable moisture and
associated chances for light snow will stay to the northeast of the
forecast area with only a few mid/high clouds expected across
northern and central Missouri. As this system tracks into the Great
Lakes later this morning, veering low level winds behind it will
result in weak cold air advection across much of the forecast area
through at least 18Z. As a result, nudged max temperatures down a
degree or two for today, though they will still be well above
average, especially across the western CWA.
Warm air advection will get underway tonight as a broad upper ridge
spreads into the Plains. Resulting downslope westerly low-level flow
will spread much-above average temperatures into the region on
Monday, with 925 hPa temperatures forecast to be over 2 standard
deviations above average. These temperatures will be further boosted
by weak confluent/compressional low-level trajectories and a
favorable environment for boundary layer mixing. As a result, near-
record highs in the lower to middle 60s appear in store for the
western half of the forecast area (reference climate section below).
Utilized biased-corrected versions of the NAM/MET/ECMWF which appear
to handle forecast temperatures well, especially if the BL mixes a
bit higher than indicated by NAM forecast soundings.
A weak front will drop into the area on Tuesday with slightly
"cooler" temperatures in the upper 50s to near 60. Will need to watch
for potential low stratus and even a few rain showers developing
early Tuesday particularly across the eastern CWA in a region of
strong low-level moisture transport. However, with warm skin
temperatures and strongly veered low-level flow, would expect stratus
to struggle to develop and if it does, it should quickly scatter out
by afternoon.
Forecast confidence then deteriorates rapidly beyond 84 hours as
a highly meridional ridge begins to build into the West Coast with
downstream mean troughing across the eastern 2/3 of North America.
Subtle yet hard-to-resolve features developing downstream of the
upper ridge are plaguing medium range models with high run-to-run
variability. At some point a developing southwest system will likely
kick out into the Plains in the Weds night to early Friday time
frame. For now, made little deviation from model consensus PoPs
keeping the highest likelihood for precip across the south Thursday
evening. Despite the eventual outcome, large scale patterns support
northerly flow and temperatures returning closer to average by the
end of the extended.
Hawblitzel
&&
.CLIMATE...
Record high temperatures for January 30:
Kansas City...68 set in 1890
St. Joseph....64 set in 1988
&&
.AVIATION...
Blanket of mid cloud cover not handled well by all but the RUC model
has continued to spread southeast, topped by additional
cirro-stratus further upstream. This cloud cover should persist
through early evening before shifting north and east as the upper
ridge builds in.
Otherwise, light/variable flow will continue this afternoon, with a
trend toward light southeast and then south overnight, ultimately
becoming southwest before daybreak with an increase in speed to
10-12 knots by mid morning.
Better flow develops aloft overnight as strong warm advection
ensues, but the vertical shear progs and degree of boundary layer
mixing later tonight don`t lead me to believe that low level wind
shear will not be a major concern at this time. Certainly if the
near surface winds do not return as expected, then LLWS may need to
be included for the 00Z TAFs.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...CORRECTED
NWS GLASGOW MT
402 PM MST MON JAN 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
A WEST TO NORTHWEST FLOW RESIDES OVER THE AREA WITH A WEAK
DISTURBANCE MOVING EAST THROUGH MONTANA TODAY. RADAR ECHOES OVER
THE STATE HAVE BEEN SPOTTY IN THE PAST 12 TO 18 HOURS BUT SOME
INCREASES ARE SHOWING UP IN NORTH-CENTRAL MONTANA AND A BIT INTO
THE WESTERN AND CENTRAL ZONES EARLY THIS AFTERNOON.
THESE ECHOES ARE EXPECTED TO INCREASE IN INTENSITY INTO THE LATE
AFTERNOON THEN BEGIN TO DIMINISH THIS EVENING. THE NAM AND GFS
SHOW IT TO HIT MAINLY THE CENTRAL ZONES...AND HAVE INCREASED POPS
ACCORDINGLY. THE HRRR SHOWED IT PRODUCE THE GREATEST QPF OVER THE
SE ZONES THAN THE GFS. HAVE LEANED MORE WITH THE GFS THOUGH BASED
ON RECENT PERFORMANCE. THE NAM HAS BEEN MUCH TOO WET WITH RECENT
SYSTEMS. ALBEIT BRIEF...THE SYSTEM LOOKS INTENSE WITH MOST OF THE
LIFT OCCURRING JUST ABOVE 700 MB AND WHERE TEMPS ARE AROUND -15C
(AND GOOD DENDREDIC GROWTH). PRECIP TYPE LOOKS TRICKY WITH MODEL
NAM SOUNDINGS SHOWING A POSSIBLE MIX WITH SNOW WHILE THE GFS IS
WARMER AND KEEPS THE PRECIP ALL LIQUID.
SYSTEM PASSES OFF TO OUR SOUTHEAST TONIGHT. WITH POSSIBLE WET
ROADWAYS...CLEARING SKIES AND TEMPS DROPPING BELOW FREEZING...ICY
ROADS ARE A GOOD POSSIBILITY. HAVE HIGHLIGHTED THIS IN AN HWO.
AFTERWARDS...IT LOOKS TO REMAIN PARTLY CLOUDY WITH CONTINUED ABOVE
NORMAL TEMPS. WENT ABOVE MAV AND MET GUIDANCE ON TEMPS...CLOSER
TO BIAS CORRECTED NUMBERS. CLOUDS LOOK TO BEGIN INCREASING
WEDNESDAY AFTERNOON WITH THE NEXT SYSTEM COMING IN. JAMBA
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
MORE SPRING-LIKE WEATHER IN THE OFFING. IN THE MIDST OF AN
AMPLIFYING PATTERN...THE LAST IN A SERIES OF SHORTWAVES MOVES SE
ACROSS THE AREA WED NIGHT...WITH SOME SPLITTING MOTION THOUGH. WILL
RAISE POPS TO A SLIGHT CHANCE OF SNOW SHOWERS.
THEN...AN UNUSUALLY STRONG UPPER RIDGE TAKES HOLD OVER THE WESTERN
STATES...THEN CLOSING OFF A CENTER OVER THE NORTHERN ROCKIES TO
THE PACIFIC NW. THIS GIVES SEVERAL DAYS OF DRY AND MAINLY SUNNY
WEATHER...WITH WINDS ON THE LIGHT SIDE. TEMPS LIKELY TO REMAIN
WELL ABOVE NORMAL WITH THICKNESSES OFTEN IN THE 540S DM...BUT 850
MB FORECAST TEMPS AND MODEL SPECTRUM DO SHOW SIGNIFICANT
DIFFERENCES...SEEMING TO INDICATE POSSIBLE STRONG INVERSIONS.
WITHOUT SNOWCOVER THOUGH...PREFER TO STAY ON THE WARM SIDE OF
GUIDANCE.
LATE IN THE PERIOD...SIGNS OF THE RIDGE SHARPENING...AND A LITTLE
FARTHER W. THIS MAY ALLOW AN ARCTIC COLD FRONT FROM THE N TO
BRUSH OUR AREA. MUCH MODEL DIFFERENCE ON TIMING...BEING ANYWHERE
FROM SUNDAY TO TUESDAY...AND ON INTENSITY OF THE FRONT AND UPPER
SUPPORT AS WELL. THEREFORE AM STAYING CONSERVATIVE AS IT IS STILL
OUT THERE ON DAYS 6 TO 8. SIMONSEN
PREVIOUS LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... MODELS
CONTINUE TO INDICATE TRANSITION FROM ZONAL PATTERN TO A HIGH
AMPLITUDE BLOCKING PATTERN EARLY IN THE EXTENDED PERIOD. NEW
WRINKLE IS TAKING THE SHORTWAVE DROPPING THROUGH THE GREAT BASIN
WEDNESDAY/WEDNESDAY NIGHT AND DEVELOPING A CLOSED LOW OVER THE
SOUTHWEST STATES. RIDGE STILL EXPECTED OVER THE NORTHERN ROCKIES
BUT WILL GET CLOSED OR PINCHED OFF BY LOW TO THE SOUTH AND TROF IN
THE EAST PACIFIC.
INITIAL PUSH OF WARM AIR INTO THE REGION WITH RIDGE WILL GRADUALLY
MODERATE AS SHORTWAVES PUSH THROUGH THE TOP OF THE RIDGE. OVERALL
STILL EXPECTING WELL ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. EBERT
&&
.AVIATION...
CEILINGS LOWERING TO AROUND 4K FT AGL OVERCAST LATE THIS AFTERNOON AND
EVENING WITH RAIN SHOWERS DEVELOPING AND MOVING E. THESE WILL
LIKELY TURN TO SNOW SHOWERS THIS EVENING BEFORE ENDING...WHICH
COULD REDUCE VISIBILITY TO 2 TO 4 MILES AND CEILINGS TO 2-3K FT AGL
FOR A SHORT TIME. VFR WITH SCATTERED TO BROKEN LAYERS ABOVE 8K FT
AGL FOR TUE. SIMONSEN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1005 AM MST SUN JAN 29 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY...
STRONG...BUT DRY WARM FRONT PUSHING E ACROSS OUR AREA THIS
MORNING...WITH TEMPS IN THE 20S AND LOWER 30S ON ONE SIDE AT 9
AM...40S AND LOWER 50S ON THE OTHER SIDE. THE WARMER AIR TO SPREAD
ACROSS THE ENTIRE CWA DURING THE REST OF THE LATE MORNING AND
AFTERNOON.
NO PRECIP REPORTED WITH THE FRONT...ALTHOUGH 88D RADAR RETURNS
INDICATING PROBABLY A FEW SNOWFLAKES AND SPRINKLES...MAINLY IN
OUR E. ALL MODELS TOO MOIST WITH THIS SYSTEM. THERE WILL BE A WEAK
SHORTWAVE FROM THE WNW THIS AFTERNOON...BUT EXPECTING MAINLY
JUST SPRINKLES IN THE WARMER AIRMASS. 850 MB TEMPS AS HIGH AS 10C
IN OUR SW TODAY.
HIGH WIND WARNING FOR SW PHILLIPS COUNTY VERIFIED WITH 70 MPH GUST
AT MALTA DOT. THE RESPONSIBLE 50-60 KT WINDS AT 850 MB MOVES
ACROSS OUR ENTIRE CWA TODAY. MODEL FORECAST SOUNDINGS SHOW
PROFILES NOT FAVORABLE TO MIX THESE SPEEDS TO SURFACE...HOWEVER
THE SOUNDINGS DO LOOK QUITE CLOSE FOR PARTS OF PETROLEUM...S
PHILLIPS AND W GARFIELD COUNTIES. UPDATE MADE EARLIER...NO FURTHER
UPDATE NEEDED. SIMONSEN
PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH
TUESDAY...WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWING A
BROAD TWO- THEMED WEATHER PATTERN ACROSS THE CONUS. THE HUDSON BAY
UPPER LOW CONTINUES TO PINWHEEL A FEW SMALLER SCALE SHORT WAVE
TROUGHS THROUGH THE GREAT LAKES AND NORTHEASTERN CONUS REGIONS.
GENERAL BROAD SCALE UPPER LEVEL TROUGHING IS IN PLACE OVER THE
REMAINDER OF THE EASTERN CONUS. A WEAK UPPER LEVEL RIDGE OVER THE
SOUTHWESTERN CONUS REGION CONTINUES TO WEAKEN UNDER A
STRENGTHENING STORM SYSTEM NOW MOVING ON SHORE OVER THE PACIFIC
NORTHWEST AND QUICKLY MOVING EASTWARD THROUGH THE NORTHERN ROCKIES
REGION. A FEW VERY SMALL SCALE SHORT WAVE TROUGHS ARE SETTING OFF
SOME THUNDERSTORMS EARLY THIS MORNING OVER THE OLYMPIC PENINSULA
OF WASHINGTON STATE.
PLENTIFUL MOISTURE IS STREAMING ALONG AND OVER THE CONTINENTAL
DIVIDE...MAKING ITS WAY OVER NORTHEAST MONTANA THIS MORNING. AN
AREA OF STRATIFORM SNOW FALL HAS SPREAD ACROSS THE CWA OVERNIGHT
AND THROUGH THE EARLY MORNING HOURS WITH JUST A FEW HIGHER
EMBEDDED AREAS OF MODERATE SNOW WHICH LASTED ONLY FOR SUDDEN
SPURTS. LOOKS LIKE THE NAM WAS MORE CORRECT IN THE PRECIP
PLACEMENT BUT A LITTLE TOO BULLISH ON THE PRECIP AMOUNTS.
FORECAST CHALLENGES INVOLVE THE PROGRESSION OF THIS STORM SYSTEM AS IT
MOVES ACROSS NORTHEAST MONTANA...INCLUDING THE EXTENT OF SNOW FALL
OVER OUR EASTERN ZONES...THE TRANSITION FROM SNOW TO A RAIN AND
SNOW MIX TO RAIN THROUGHOUT THE DAY TODAY FROM SOUTHWEST TO
NORTHEAST...AND THE HIGH WINDS OVER THE LITTLE ROCKIES AND HIGHWAY
191 TODAY.
THE INITIAL PUSH OF SNOWFALL ACROSS NORTHEAST MONTANA HAS ALREADY
MADE ITS WAY ACROSS OUR CWA. ACCORDING TO THE LATEST HRRR MODEL
RUNS...THERE MAY BE ANOTHER PUSH OR BAND OF SNOWFALL SET TO MOVE
ACROSS THE CWA LATER THIS MORNING...BUT IT LOOKS TO AMOUNT TO NOT MUCH.
TEMPERATURES A LITTLE TRICKY THIS MORNING. WE MAY HAVE ALREADY
REACHED OUR MORNING LOWS DURING THE MIDNIGHT HOUR. SURFACE
OBSERVATION TRENDS SHOWING STEADILY INCREASING TEMPERATURES EARLY
THIS MORNING BEHIND THE WARM FRONT JUST WEST AND SOUTHWEST OF OUR
CWA BORDER. TRIED TO SHOW A NON-DIURNAL TEMPERATURE TREND THIS
MORNING TO REPRESENT THIS THINKING. AS THE FRONT PUSHES THROUGH
OUR CWA TODAY...SNOW WILL TRANSITION OVER TO A RAIN AND SNOW
MIX...THEN BECOME ALL RAIN THIS AFTERNOON AS TEMPERATURES QUICKLY
CLIMB TO WELL ABOVE NORMAL LEVELS FOR THIS TIME OF YEAR. EXPECT
THE RAIN AND SNOW MIX TO BE AN ISSUE ONLY FOR THE 6 HOUR PERIOD
TODAY BETWEEN EARLY MORNING AND MID DAY.
WESTERLY WINDS ALREADY EARLY THIS MORNING AT ZORTMAN MINE AND THE
DOT SITE SOUTH OF MALTA ARE GUSTING IN THE 40 TO 50 MPH RANGE. THE
HIGH WIND WARNING LOOKS TO BE WELL PLACED AND WELL TIMED. KEEP AN
EYE ON ADDITIONAL SURROUNDING AREAS OF HIGHER TERRAIN IN CASE A
STRAY HIGH WIND GUST MIXES DOWN TO THE SURFACE...SAY IN PETROLEUM
COUNTY.
TONIGHT...THE STORM SYSTEM MAKES A QUICK EXIT TO THE EAST AS AN
UPPER LEVEL SHORT WAVE RIDGE SUSTAINS THE WARM UP TODAY AND MONDAY
TO THE TUNE OF NEARLY 20 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
LATE MONDAY INTO EARLY TUESDAY...ANOTHER UPPER LEVEL DISTURBANCE
QUICKLY SLIDES OVER THE NORTHERN ROCKIES AND THROUGH NORTHEAST
MONTANA...BRINGING A SPOTTY AND DISORGANIZED CHANCE FOR RAIN AND
SNOW TO PORTIONS OF OUR CWA. BMICKELSON
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
PATTERN TRANSITIONS FROM ACTIVE ZONAL FLOW TO A HIGH AMPLITUDE
RIDGE ACROSS THE WESTERN STATES DURING THE EARLY DAYS OF THE
EXTENDED PERIOD. MODELS INDICATE TWO SHORTWAVES SLIDING ACROSS
EASTERN MONTANA WITH REASONABLE AGREEMENT ON TIMING. THE FIRST
WAVE CROSSES NORTHEAST MONTANA TUESDAY NIGHT BUT IS VERY WEAK WITH
NOT MUCH MOISTURE SO EXPECT DRY CONDITIONS. SECOND WAVE FOLLOWS
CLOSE BEHIND ON WEDNESDAY/WEDNESDAY NIGHT. THIS WAVE IS STRONGER
WITH BETTER DYNAMICS AND MOISTURE BUT MODELS STILL SUGGESTING BEST
CHANCES FOR PRECIPITATION WILL BE ACROSS SOUTHWEST MONTANA WITH
UPPER FLOW VEERING AS RIDGE BUILDS TO THE WEST. WILL KEEP WITH
CONSENSUS FOR NOW AND STAY WITH DRY FORECAST.
RIDGE BEGINS TO DOMINATE THE NORTHERN ROCKIES BY THURSDAY WITH
WARM AIR PUSHING EAST OF THE DIVIDE. BY THE WEEKEND THE WARM AIR
WILL BE FIRMLY IN PLACE OVER MONTANA...ALTHOUGH WITH LITTLE WIND
MIXING WILL BE DIFFICULT. EBERT
&&
.AVIATION...
VFR. A BAND OF LIGHT SNOW MAY BRIEFLY AFFECT GLENDIVE AND SIDNEY
THIS MORNING...OTHERWISE MID AND HIGH CLOUDS ARE EXPECTED TO STICK
AROUND TODAY. SOME LOW LEVEL WIND SHEAR IS POSSIBLE AS LIGHT WINDS
AT THE SURFACE INCREASE DRAMATICALLY OFF THE GROUND ESPECIALLY
FROM GLASGOW TO MILES CITY CORRIDOR TODAY. MID LEVEL WINDS SHOULD
DIMINISH TONIGHT. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR SOUTHWEST
PHILLIPS.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
345 AM MST SUN JAN 29 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWING A BROAD TWO-
THEMED WEATHER PATTERN ACROSS THE CONUS. THE HUDSON BAY UPPER LOW
CONTINUES TO PINWHEEL A FEW SMALLER SCALE SHORT WAVE TROUGHS
THROUGH THE GREAT LAKES AND NORTHEASTERN CONUS REGIONS. GENERAL
BROAD SCALE UPPER LEVEL TROUGHING IS IN PLACE OVER THE REMAINDER
OF THE EASTERN CONUS. A WEAK UPPER LEVEL RIDGE OVER THE
SOUTHWESTERN CONUS REGION CONTINUES TO WEAKEN UNDER A
STRENGTHENING STORM SYSTEM NOW MOVING ON SHORE OVER THE PACIFIC
NORTHWEST AND QUICKLY MOVING EASTWARD THROUGH THE NORTHERN ROCKIES
REGION. A FEW VERY SMALL SCALE SHORT WAVE TROUGHS ARE SETTING OFF
SOME THUNDERSTORMS EARLY THIS MORNING OVER THE OLYMPIC PENINSULA
OF WASHINGTON STATE.
PLENTIFUL MOISTURE IS STREAMING ALONG AND OVER THE CONTINENTAL
DIVIDE...MAKING ITS WAY OVER NORTHEAST MONTANA THIS MORNING. AN
AREA OF STRATIFORM SNOW FALL HAS SPREAD ACROSS THE CWA OVERNIGHT
AND THROUGH THE EARLY MORNING HOURS WITH JUST A FEW HIGHER
EMBEDDED AREAS OF MODERATE SNOW WHICH LASTED ONLY FOR SUDDEN
SPURTS. LOOKS LIKE THE NAM WAS MORE CORRECT IN THE PRECIP
PLACEMENT BUT A LITTLE TOO BULLISH ON THE PRECIP AMOUNTS.
FORECAST CHALLENGES INVOLVE THE PROGRESSION OF THIS STORM SYSTEM AS IT
MOVES ACROSS NORTHEAST MONTANA...INCLUDING THE EXTENT OF SNOW FALL
OVER OUR EASTERN ZONES...THE TRANSITION FROM SNOW TO A RAIN AND
SNOW MIX TO RAIN THROUGHOUT THE DAY TODAY FROM SOUTHWEST TO
NORTHEAST...AND THE HIGH WINDS OVER THE LITTLE ROCKIES AND HIGHWAY
191 TODAY.
THE INITIAL PUSH OF SNOWFALL ACROSS NORTHEAST MONTANA HAS ALREADY
MADE ITS WAY ACROSS OUR CWA. ACCORDING TO THE LATEST HRRR MODEL
RUNS...THERE MAY BE ANOTHER PUSH OR BAND OF SNOWFALL SET TO MOVE
ACROSS THE CWA LATER THIS MORNING...BUT IT LOOKS TO AMOUNT TO NOT MUCH.
TEMPERATURES A LITTLE TRICKY THIS MORNING. WE MAY HAVE ALREADY
REACHED OUR MORNING LOWS DURING THE MIDNIGHT HOUR. SURFACE
OBSERVATION TRENDS SHOWING STEADILY INCREASING TEMPERATURES EARLY
THIS MORNING BEHIND THE WARM FRONT JUST WEST AND SOUTHWEST OF OUR
CWA BORDER. TRIED TO SHOW A NON-DIURNAL TEMPERATURE TREND THIS
MORNING TO REPRESENT THIS THINKING. AS THE FRONT PUSHES THROUGH
OUR CWA TODAY...SNOW WILL TRANSITION OVER TO A RAIN AND SNOW
MIX...THEN BECOME ALL RAIN THIS AFTERNOON AS TEMPERATURES QUICKLY
CLIMB TO WELL ABOVE NORMAL LEVELS FOR THIS TIME OF YEAR. EXPECT
THE RAIN AND SNOW MIX TO BE AN ISSUE ONLY FOR THE 6 HOUR PERIOD
TODAY BETWEEN EARLY MORNING AND MID DAY.
WESTERLY WINDS ALREADY EARLY THIS MORNING AT ZORTMAN MINE AND THE
DOT SITE SOUTH OF MALTA ARE GUSTING IN THE 40 TO 50 MPH RANGE. THE
HIGH WIND WARNING LOOKS TO BE WELL PLACED AND WELL TIMED. KEEP AN
EYE ON ADDITIONAL SURROUNDING AREAS OF HIGHER TERRAIN IN CASE A
STRAY HIGH WIND GUST MIXES DOWN TO THE SURFACE...SAY IN PETROLEUM
COUNTY.
TONIGHT...THE STORM SYSTEM MAKES A QUICK EXIT TO THE EAST AS AN
UPPER LEVEL SHORT WAVE RIDGE SUSTAINS THE WARM UP TODAY AND MONDAY
TO THE TUNE OF NEARLY 20 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
LATE MONDAY INTO EARLY TUESDAY...ANOTHER UPPER LEVEL DISTURBANCE
QUICKLY SLIDES OVER THE NORTHERN ROCKIES AND THROUGH NORTHEAST
MONTANA...BRINGING A SPOTTY AND DISORGANIZED CHANCE FOR RAIN AND
SNOW TO PORTIONS OF OUR CWA. BMICKELSON
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
PATTERN TRANSITIONS FROM ACTIVE ZONAL FLOW TO A HIGH AMPLITUDE
RIDGE ACROSS THE WESTERN STATES DURING THE EARLY DAYS OF THE
EXTENDED PERIOD. MODELS INDICATE TWO SHORTWAVES SLIDING ACROSS
EASTERN MONTANA WITH REASONABLE AGREEMENT ON TIMING. THE FIRST
WAVE CROSSES NORTHEAST MONTANA TUESDAY NIGHT BUT IS VERY WEAK WITH
NOT MUCH MOISTURE SO EXPECT DRY CONDITIONS. SECOND WAVE FOLLOWS
CLOSE BEHIND ON WEDNESDAY/WEDNESDAY NIGHT. THIS WAVE IS STRONGER
WITH BETTER DYNAMICS AND MOISTURE BUT MODELS STILL SUGGESTING BEST
CHANCES FOR PRECIPITATION WILL BE ACROSS SOUTHWEST MONTANA WITH
UPPER FLOW VEERING AS RIDGE BUILDS TO THE WEST. WILL KEEP WITH
CONSENSUS FOR NOW AND STAY WITH DRY FORECAST.
RIDGE BEGINS TO DOMINATE THE NORTHERN ROCKIES BY THURSDAY WITH
WARM AIR PUSHING EAST OF THE DIVIDE. BY THE WEEKEND THE WARM AIR
WILL BE FIRMLY IN PLACE OVER MONTANA...ALTHOUGH WITH LITTLE WIND
MIXING WILL BE DIFFICULT. EBERT
&&
.AVIATION...
VFR. CLOUDS WILL LOWER THIS MORNING AS A DISTURBANCE TRACKS INTO
NORTHEAST MONTANA. OCCASIONAL MVFR CONDITIONS ARE POSSIBLE WITH A
LITTLE LIGHT SNOW THIS MORNING. WINDS WILL BECOME WESTERLY BY LATE
MORNING AT 10 TO 20 KTS THEN DIMINISH IN THE EVENING. RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR SOUTHWEST
PHILLIPS.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
959 PM EST MON JAN 30 2012
.SYNOPSIS...
A WARM FRONT WILL CROSS THE REGION OVERNIGHT...BRINGING A SHOT OF
LIGHT SNOW. IN THE WAKE OF THIS SYSTEM...MILDER TEMPERATURES WILL
BE WITH US ON TUESDAY AND WEDNESDAY. THE BEST CHANCE OF LIGHT RAIN
DURING THIS TIME FRAME WILL BE TUESDAY NIGHT INTO WEDNESDAY...WHEN
A WEAK COLD FRONT CROSSES CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
10PM UPDATE...FORECAST IS STILL ON TRACK WITH A WARM FRONT MOVING
THROUGH TONIGHT. IT IS CURRENTLY BRINGING SOME LIGHT SNOW SHOWERS
TO THE CWA. THE HRRR AND THE RUC SEEM TO BE HANDLING IT QUITE
WELL. OTHER MODELS ALSO LOOK TO BE IN GOOD AGREEMENT. THIS FRONT
WILL LIFT OUT OVER THE NEXT SEVERAL HOURS, TAKING THE SNOW SHOWERS
WITH IT. HAVE BACKED OF ON POPS BEHIND THE FRONT AS ALL MODELS
HAVE THE PRECIP ENDING IN THE EARLY MORNING HOURS. STILL KEPT IN
SOME LOW POPS FOR AN ISOLATED SHOWER, BUT PROBABLY WONT BE MORE
THEN SOME FLURRIES. LOOKING UPSTREAM, TEMPS ARE ALREADY BEGINNING
TO VERY SLOWLY RISE IN WESTERN PA. THIS SHOULD BE THE OVERALL TREND
TONIGHT BEHIND THE FRONT. THIS WILL ALLOW SOME VERY WARM TEMPS TO
COME IN TOMORROW, AND IF ANY SUN BREAKS OUT, TEMPS COULD BE HIGHER
THAN FORECAST. THIS WILL ALLOW ANY PRECIP THAT DOES FALL TOMORROW
TO CHANGE OVER TO RAIN, MAINLY AFTER DAYBREAK.
4 PM UPDATE... OVERRUNNING/WAA LGT SNOW IS ALREADY ENTERING WRN NY
ATTM. THIS PCPN SHIELD WILL MAKE STEADY EWD PROGRESS THE NEXT FEW
HRS...AND SHOULD ENVELOPE MUCH OF THE FA (EXCEPT PERHAPS THE FAR
SRN ZNS)...BY 00-02Z. THE SUPPORTING AREA OF ISEN LIFT...DUE TO
ITS RAPID MOVEMENT HOWEVER...WILL ALSO EXIT MOST OF THE CWA JUST
ABT AS QUICKLY. THUS...WE`RE LOOKING FOR STEADIER -SN TO TAPER OFF
ACRS THE TWIN TIERS BY 04-07Z...WITH -SN PROBABLY HANGING ON UNTIL
EARLY TUE IN THE FAR N. IN GENERAL...AN INCH OR LESS IS EXPECTED
OVER THE TWIN TIERS...WITH 1-3" ACRS THE NRN FINGER LKS...THE SRN
TUG HILL RGN...AND THE WRN MOHAWK VLY.
TEMPS WILL EXHIBIT A NON-DIURNAL TREND OVERNIGHT...GENERALLY
RISING SLOWLY AFTER ABT 02-03Z. IN FACT...IN SOME OF OUR NORMALLY
MILDER LAKE PLAIN AREAS...TEMPS SHOULD INCH ABV FRZG LATE
TNT...AND A -RA/-SN MIX COULD OCCUR IN THESE LOCALES.
PREV DISC... 1 PM UPDATE... THE LES ADVSY HAS EXPIRED ON
SCHEDULE. LOW- LVL WAA AND BACKING FLOW HAVE TAKEN THEIR
TOLL...AND THE BAND CONTINUES TO LOOK LESS ORGANIZED ATTM.
THE ONLY OTHER CHGS THIS UPDATE WERE MINOR TWEAKS TO EARLY TO MID-
AFTN TEMPS AND OUR MAX TEMP GRID.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
410 PM UPDATE... THE LOW-LVL WARM FRNT SHOULD REMAIN NEARLY
STATIONARY JUST N OF THE FA TUE AND TUE EVE. THE BEST CHC FOR ANY
-RA/-DZ WILL BE UP CLOSER TO THIS BNDRY...ACRS OUR NRN/ERN ZNS.
ELSEWHERE...CONDS SHOULD STAY LARGELY PCPN-FREE.
A MUCH MILDER AMS WILL BUILD IN ON TUE...AND EVEN WITH ABUNDANT
CLD COVER...HIGHS SHOULD REACH WELL INTO THE 40S...AND MAY TOUCH
50 OVER SXNS OF NE PA. IF ANY SUNSHINE WERE TO BREAK
THROUGH...READINGS COULD GET EVEN WARMER (WELL INTO THE 50S)...BUT
THIS WILL PROBABLY BE TOUGH...GIVEN ALL THE LOW-LVL MOIST IN
PLACE.
TUE NGT...AS A FAST MOVG UPPER TROUGH AND WEAK SFC WAVE MOVE ACRS
ONT/QUE...A COLD FRONT WILL CROSS CNY/NE PA FROM NW TO SE. SCTD
-SHRA SHOULD ACCOMPANY THIS SYSTEM...AS IT APPCHS AND PUSHES
THROUGH.
WED AND WED NGT...VERY WEAK CAA WILL ENSUE BEHIND THE
FRNT...LIKELY INSUFFICIENT FOR ANY REAL LAKE RESPONSE. BY THU...A
SRN STREAM SYSTEM IS PROGGED TO TRACK FM THE LWR MS VLY ENEWD INTO
THE SERN STATES. ALTHOUGH THERE IS CERTAINLY MODEL UNCERTAINTY IN
THE POSITIONING/EVOLUTION OF THIS SYSTEM...CURRENT CONSENSUS
SUGGESTS IT WILL STAY PRIMARILY S OF THE FA. FOR NOW...WE BRING IN
A CHANCE OF -RA/-SN...MOSTLY ACRS NE PA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS BEGIN IN DECENT AGREEMENT FOR THE EXTENDED FORECAST PERIOD.
THE GFS AND THE ECMWF, BOTH SHOW A WEAK UPPER LEVEL TROUGH OVER
THE CWA AT 00Z FRIDAY. THEY BOTH THEN SHOW A FLAT UPPER LEVEL
RIDGE BUILDING BY 00Z SAT. MODELS THEN DIVERGE FOR THE WEEKEND.
THE GFS HAS A SFC RIDGE BUILDING, KEEPING THE AREA MOSTLY DRY,
WITH POSSIBLY SOME LAKE EFFECT FLURRIES. THE ECMWF HAS A LOW
PRESSURE SYSTEM SKIMMING BY THE CWA TO THE SOUTH AND GOING OUT TO
SEA. THE ECMWF HAS BEEN BOUNCING SYSTEMS ALL OVER LATELY, WHICH
HAS BROUGHT CONFIDENCE DOWN IN ITS SOLUTIONS, SO HAVE KEPT POPS
BELOW SLIGHT CHANCE FOR NOW.
BY SUNDAY NIGHT, BOTH MODELS HAVE SOME TYPE OF SYSTEM DEVELOPING
AND MOVING NEAR THE AREA. THE GFS HAS A STRONG LOW OVER THE GREAT
LAKES AND RAIN MOVING INTO THE CWA MONDAY NIGHT WITH A CHANGE TO
MIXED AND THEN SNOW, BEHIND A COLD FRONT BY MONDAY AFTERNOON. THE
ECMWF HAS A WEAK LOW MOVING OF THE COAST OF SOUTHERN NJ AND THEN
OUT TO SEA. IT BRINGS SOME LIGHT SNOW TO THE AREA. HAVE CHC POPS
FOR SUNDAY NIGHT AND DROP TO SLIGHT CHC FOR MOST OF THE CWA
MONDAY, WITH A MIX OF SNOW/RAIN AS THE PTYPE.
HIGH TEMPS FOR THE WEEKEND AND BEGINNING OF THE WEEK LOOK TO BE
ABOVE NORMAL, REACHING INTO THE MID TO UPPER 30S, TO POSSIBLY
AROUND FOR IN NEPA. LOWS EACH NIGHT LOOK TO BE IN THE MID 20S.
SUNDAY NIGHT DOES LOOK AS THOUGH WARM ADVECTION WILL CAUSE A NON
DIURNAL CYCLE, WITH THE LOW HAPPENING IN THE LATE EVENING, EARLY
MORNING HOURS, IF THE GFS IS CORRECT.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SNOW IS SPREADING FROM WEST TO EAST ACROSS THE TERMINALS THIS
EVENING, AHEAD OF AN APPROACHING WARM AIR PUSH. CEILINGS ARE
MAINLY IN THE 4000-8000 FOOT RANGE, BUT MAY FALL TO BETWEEN 2500
AND 4000 FEET IN SNOW SHOWERS. VISIBILITIES MAY FLUCTUATE BETWEEN
3SM AND P6SM AS WELL.
THE SNOW SHOWERS WILL SPREAD FROM NEAR ELM AT 0Z, TO ITH-BGM-SYR
AT 1Z, AND RME AT 2Z. AVP WILL BE BARELY SKIRTED BY THE SNOW
SHOWERS, SO WE EXPECT VFR CONDITIONS AT THE TERMINAL.
THE SNOW SHOWERS WILL TAPER OFF BETWEEN 3Z AND 6Z.
SKIES WILL BE MOSTLY CLOUDY WITH A VFR DECK ON TUESDAY AND TUESDAY
NIGHT. WINDS WILL SHIFT TO THE SOUTHWEST AT 8 TO 12 KNOTS TUESDAY
AFTERNOON, WITH A FEW HIGHER GUSTS POSSIBLE.
.OUTLOOK...
WED...MVFR. OCCASIONAL RAIN SHOWERS.
WED NIGHT...VFR.
THUR...VFR. CHC MVFR SNOW SHOWERS VCNTY KSYR-KRME.
FRI THRU SAT...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...MLJ/SLI
SHORT TERM...MLJ
LONG TERM...SLI
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
353 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING WAVE OF LOW PRESSURE WILL MOVE ACROSS THE REGION
THROUGH THIS EVENING...BRINGING A BRIEF PERIOD OF HEAVY SNOW TO MOST
LOCATIONS. THIS WILL BE FOLLOWED BY LAKE SNOWS EAST OF THE LAKES
TONIGHT AS A WESTERLY FLOW OF BRIEFLY COLDER AIR SPREADS ACROSS THE
LOWER LAKES. AN APPROACHING WARM FRONT WILL THEN BRING ANOTHER ROUND
OF WIDESPREAD LIGHT SNOW TO THE AREA LATE MONDAY AND MONDAY NIGHT...
FOLLOWED BY A SIGNIFICANT WARMUP FOR TUESDAY AND ESPECIALLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
FOR THE REMAINDER OF THIS AFTERNOON...LAKE SNOWS WILL LINGER EAST OF
LAKE ONTARIO. IR SHOWS LEFT OVER MOISTURE FROM THIS MORNINGS ROUND
OF SNOWS OF LAKE ERIE. THIS MOISTURE IS NOW MOVING ACROSS WHAT WAS A
WEAK LAKE EFFECT BAND...AND ENHANCING IT. EXPECT COUPLE HOURS OF
FAIRLY WIDESPREAD SNOWS...WITH LOCALLY HEAVY SNOWFALL ALONG A LAKE
CONVERGENCE BAND EXTENDING FROM NEAR WATER TOWN TO FORT DRUM. THIS
ALL SHOULD DIMINISH IN INTENSITY LATE AFTERNOON...BRIEFLY...BEFORE
THE NEXT SYSTEM COMES EARLY THIS EVENING.
A QUITE VIGOROUS SHORTWAVE AN WEAK SURFACE REFLECTION WILL QUICKLY
MOVE ACROSS THE REGION THROUGH THIS EVENING. THIS WILL CAUSE TWO
PERIODS OF SNOW...ONE WITH THE SHORTWAVE...AND THEN ANOTHER IN LAKE
EFFECT BEHIND HIT.
THROUGH THIS EVENING (THE SHORTWAVE)...A QUITE DISTINCT VORT MAX
EMBEDDED IN A CYCLONIC 500 MB TROF WILL CROSS THE REGION BETWEEN 500
PM AND 1000 PM. THIS SHORTWAVE IS PRODUCING AMPLE LIFT IN ITS OWN
RIGHT...WITH FAIRLY WIDESPREAD 1/4SM TO 1/2SM VSBY IN MODERATE TO
HEAVY SNOW ACROSS SOUTHEASTERN MICHIGAN. IF ANYTHING...SNOWFALL
SHOULD BE ENHANCED BY LAKE MOISTURE AND MODEST AMOUNTS OF LAKE
INDUCED INSTABILITY AHEAD OF THE BOUNDARY. THE SHORTWAVE WILL COOL
TEMPERATURES ALOFT...WITH EQUILIBRIUM LEVELS RISING TO NEAR 20K
FEET. MID LEVEL LAPSE RATES DROP TO AROUND 8 C/KM ALOFT. THIS ALL
INCREASES CONFIDENCE IN A TWO OR THREE HOUR PERIOD OF QUITE INTENSE
SNOWFALL ACROSS MUCH OF THE CWA. AS ONE MIGHT EXPECT...THIS RESULTS
IN A PERIOD OF VERY GOOD SNOW GROWTH...WITH A NEARLY CLASSIC
SIGNATURE OF BEST LIFT ALIGNED WITH -12C TO -20C TEMPERATURES ALOFT.
WHILE THE BRIEF NATURE OF THE EVENT WILL LIMIT SNOWFALL
TOTALS...EXPECT IT WILL HAVE A SIGNIFICANT IMPACT DURING THAT TIME.
FOR THIS REASON...WILL GO WITH A WINTER WEATHER ADVISORY ACROSS MOST
OF THE CWA. GENERALLY SPEAKING...THIS FEATURE SHOULD BRING A QUICK 2
TO 4 INCHES OF SNOW THROUGH THIS EVENING. AMOUNTS WILL TAPER OFF
FURTHER SOUTH AND EAST...AND FOR NOW WILL KEEP
ALLEGHENY/LIVINGSTON/ONTARIO COUNTIES OUT OF THE ADVISORY...AS THE
LACK OF LAKE ENHANCEMENT SHOULD LIMIT SNOWS TO AROUND 2 INCHES.
FINALLY...ITS WORTH NOTING THAT A BRIEF PERIOD OF GUSTY WINDS IS
LIKELY IMMEDIATELY BEHIND THE LOW...WHICH MAY CAUSE AREAS OF BLOWING
AND DRIFTING SNOW.
AFTER MIDNIGHT (LAKE EFFECT) WHILE THE LOW WILL QUICKLY EXIT EAST
LATE THIS EVENING...THERE WILL BE A SECOND ROUND OF LAKE SNOWS ON
THE BACK OF THE SYSTEM. WINDS WILL SHIFT TO THE WNW BEHIND THE
SYSTEM. OFF LAKE ERIE...EXPECT AMOUNTS TO BE MODEST...WITH A CAP AT
AROUND 7000 FT...AND A LIMITED FETCH OFF THE LAKE. HERE...BEST SNOWS
SHOULD COME LATE EVENING INTO THE EARLY MORNING HOURS...WHEN
MOISTURE LINGERS BEHIND THE EXITING SHORTWAVE. OFF LAKE
ONTARIO...CONSENSUS WIND FORECASTS POINT TO THE BEST LAKE SNOWS
ACROSS OSWEGO COUNTY...AND IN NORTHERN PORTIONS OF WAYNE AND CAYUGA
COUNTIES. HERE...THE CAP WILL BE MORE LIKE 9000 FT...WITH A LONGER
FETCH OFF THE LAKE. THE BAND MAY BRIEFLY DISRUPT DURING THE EARLY
MORNING HOURS...BUT WINDS ARE AT A NEARLY IDEAL SPEED...AND THEY
BECOME BETTER ALIGNED TOWARD DAYBREAK. ALL THIS POINTS TO A QUITE
INTENSE LAKE EFFECT BAND TO DEVELOP AT THIS TIME...WITH SNOWFALL
RATES TO 2 INCHES PER HOUR POSSIBLE. THIS SHOULD BE FAIRLY SHORT
LIVED...AS WINDS BECOME MORE SHEARED ON MONDAY MORNING...BUT THIS
AREA DOES BEAR WATCHING FOR A POSSIBLE UPGRADE TO WARNING.
FINALLY...THERE IS THE ISSUE OF THE LAKE ONTARIO SOUTH SHORES FROM
NIAGARA COUNTY TO MONROE COUNTY. IT IS POSSIBLE A BAND WILL MEANDER
ONSHORE THERE FROM TIME TO TIME...ESPECIALLY DURING THE LAKE EVENING
HOURS. THIS BEARS WATCHING...BUT FOR NOW WILL FOCUS THE ADVISORY IN
THESE COUNTIES ON THE SHORTWAVE...AND NOT THE LAKE EFFECT AFTERWARD.
AS HAS BEEN THE CASE FOR THE PAST SEVERAL DAYS...THE BREAK BETWEEN
SYSTEMS WILL BE BRIEF. ACTUALLY...SNOWS FROM THE NEXT SYSTEM MAY
START BEFORE THE LAKE EFFECT ON EASTERN LAKE ONTARIO IS COMPLETELY
DONE. HOWEVER...THIS SYSTEM WILL BE VERY DIFFERENT FROM THE LAST.
SNOW WILL BE CAUSED BY MORE OF A BROAD AREA OF MID-LEVEL WARM AIR
ADVECTION. THIS SHOULD RESULT IN A MORE GENERAL SNOWFALL...MUCH LESS
INTENSE THAN EARLIER SYSTEMS. EXPECT AROUND AN INCH OF ACCUMULATION
FROM THIS ACROSS FAR WESTERN NEW YORK FROM THIS THROUGH SUNSET.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
THE AXIS OF HIGH PRESSURE WILL BE WELL EAST OF THE FORECAST AREA
MONDAY NIGHT WITH AS STRONG WARM ADVECTION PATTERN DEVELOPING.
BOUNDARY LAYER TEMPS WILL REMAIN BELOW FREEZING EARLY ON AS THE
ELEVATED WARM FRONT CROSSES THE REGION WITH A BAND OF ASSOCIATED
LIGHT SNOW. USE OF THE WARM LAYER ALOFT PRECIP TYPE TOOL INDICATES
THAT THERE MAY BE SOME MIXED WINTRY PRECIP ALONG THE TRAILING EDGE
OF THE SNOW...ALTHOUGH THE VERTICAL MOISTURE PROFILE IS RATHER
NARROW AND MAY OUTRUN THE WARMING LEADING TO A DRIER PROFILE BY THE
TIME THAT THE WARM AIR ALOFT ARRIVES. WILL SHOW CHANCE POPS FOR
LIGHT MIX OF FREEZING RAIN AND SLEET BETWEEN MIDNIGHT AND DAYBREAK
ON TUESDAY...AND SHORT LIVED FOR ANY ONE AREA AS THIS TRAILING EDGE
OR PRECIP LIFTS THROUGH.
TUESDAY WILL BE CHARACTERIZED BY WARMER TEMPS AND BREEZY SOUTH TO
SOUTHWEST WINDS...TEMPS RISING TO THE MID TO UPPER 40S FOR MOST
LOCALES...AND IN THE MID 30S TO AROUND 40 FOR THE EASTERN LAKE
ONTARIO REGION. THE PRECIP WILL HAVE BEEN SHUNTED TO THE NORTH AND
THERE WILL REMAIN A CHANCE OF LIGHT RAIN OR A MIX OF RAIN AND WET
SNOW...BUT EXPECT IT TO BE DRY FOR THE REST OF THE REGION.
LOW PRESSURE MOVING NEAR WEST TO EAST ACROSS THE CENTRAL GREAT LAKES
AND TO THE NORTH OF LAKE ONTARIO WILL BRING A COLD FRONT TO THE WEST
OF THE REGION TUESDAY NIGHT...THE WARM SECTOR REMAINING IN PLACE
THROUGH THE NIGHT. WILL SEE LEFT FRONT EXIT REGION OF UPPER JET
ENHANCING PRECIP AHEAD OF THE COLD FRONT WITH LIKELY POPS FOR LIGHT
RAIN DURING THE NIGHT. THE TEMPS WILL ALSO REMAIN ON THE WARM SIDE
WITH OVERNIGHT LOWS NOT FALLING BELOW 40 DEGREES FOR MUCH OF THE
FORECAST AREA...SOME MIDDLE TO LOWER 30S FOR THE NORTH COUNTRY AND
THAT WILL BE EARLY IN THE EVENING WITH TEMPS RISING OVERNIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE SURFACE COLD FRONT TRAILING THE LOW TO OUR NORTH WILL CROSS THE
REGION WEDNESDAY MORNING WITH VERY MILD MORNING TEMPS GIVING WAY TO
FALLING TEMPS DURING AFTERNOON. BEST RAIN CHANCES WILL BE
EARLY...WITH DRYING EXPECTED BY AFTERNOON IF THE CURRENT MODEL
TIMING HOLDS.
COLD ADVECTION BEHIND THE SYSTEM WILL BRING TEMPS DOWN...BUT STILL
ABOVE CLIMO FOR THURSDAY WITH A FEW LIGHT SNOW SHOWERS POSSIBLE EAST
OF THE LAKES.
THURSDAY NIGHT INTO NEXT WEEKEND BECOME MORE UNCERTAIN WITH THE
LATEST GFS AND ECMWF RAPIDLY BECOMING DRAMATICALLY DIFFERENT IN THE
SYNOPTIC DETAILS AND EVEN THE LARGE SCALE PATTERN. THE GFS IS MUCH
LESS AMPLIFIED WITH A FLAT TROUGH ON THURSDAY NIGHT WITH A DIGGING
TROUGH SHOWING STRONGER AMPLIFICATION ON SATURDAY. THE ECMWF IS MORE
AMPLIFIED EVEN ON THE FAST MOVING SHORT WAVES THURSDAY THROUGH
FRIDAY...AND DEPICTS A DEEP AMPLITUDE 500MB TROUGH IN THE LEE OF THE
ROCKIES ON FRIDAY MORNING...TRYING TO BECOME A CUTOFF LOW ON
SATURDAY...THEN A POSITIVELY TILTED AND DEEP AMPLITUDE WAVE ON
SUNDAY.
GIVEN THE LACK OF MODEL CONSISTENCY...WILL STICK CLOSE TO THE
CONTINUITY FORECAST FOR LATE IN THE WEEK INTO NEXT WEEKEND...WITH A
CLIPPER PASSING TO THE WEST AND SOUTH OF US ON FRIDAY NIGHT AND
SATURDAY BRINGING SOME SNOW SHOWERS AND FLURRIES TO THE FORECAST
AREA. THE COMPLEXITY OF THE PATTERN EVOLUTION LATE NEXT WEEK WILL
LIKELY RESULT IN ONGOING MODEL UNCERTAINTY FOR SEVERAL MORE DAYS
UNTIL MODELS BEGIN TO CONVERGE ON A COMMON SOLUTION.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FOR THE 21Z TAFS...A SIGNIFICANT SHORTWAVE WILL MOVE ACROSS THE
REGION. BASED ON UPSTREAM OBSERVATIONS...AND NUMERICAL
GUIDANCE...HAVE AMPLE CONFIDENCE TO CARRY A PERIOD OF HEAVY SNOW
WITH 1/4SM VSBY AT MOST TAF SITES. TIMING BASED ON A COMBINATION
OF THE HRRR MODEL AND RADAR TRENDS.
CONDITIONS WILL IMPROVE WITH THE EXIT OF THIS SYSTEM...WITH MAINLY
MVFR CONDITIONS OVERNIGHT. THE EXCEPTION WILL BE IN LAKE EFFECT
BANDS...BUT IN THE WNW FLOW THESE TYPICALLY HAVE ONLY MINOR
IMPACTS ON TAF SITES...THOUGH LOCAL AND BRIEF PERIODS OF LOWER
CONDITIONS ARE POSSIBLE.
OUTLOOK...
MONDAY NIGHT...IFR WITH LIGHT SNOW LIKELY.
TUESDAY...IFR WITH LIGHT SNOW LIKELY EAST OF LAKE ONTARIO...
ELSEWHERE IMPROVING TO MAINLY VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
FRIDAY...VFR.
&&
.MARINE...
MODERATELY STRONG SOUTHWESTERLIES AND WESTERLIES WILL CONTINUE
ACROSS THE LOWER LAKES REGION RIGHT INTO MONDAY. THIS WILL RESULT
IN CONDITIONS REMAINING SOLIDLY IN THE SMALL CRAFT ADVISORY RANGE
THROUGH MONDAY MORNING...BEFORE AN APPROACHING WARM FRONT RESULTS
IN DIMINISHING WINDS MONDAY AFTERNOON AND EVENING.
LOW PRESSURE PASSING TO THE NORTH ON WEDNESDAY WILL CAUSE
SOUTHWESTERLY WINDS TO INCREASE. WINDS MAY APPROACH GALES FOR A
PERIOD.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ007-
008.
WINTER WEATHER ADVISORY UNTIL NOON EST MONDAY FOR NYZ004>006.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ001>003-010-011.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR NYZ012-019-
020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1235 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING WAVE OF LOW PRESSURE WILL CROSS THE REGION LATE
AFTERNOON THROUGH THIS EVENING...BRINGING A BRIEF PERIOD OF HEAVY
SNOW TO MOST LOCATIONS. THIS WILL BE FOLLOWED BY LAKE SNOWS EAST
OF THE LAKES TONIGHT AS A WESTERLY FLOW OF BRIEFLY COLDER AIR
SPREADS ACROSS THE LOWER LAKES. AN APPROACHING WARM FRONT WILL
THEN BRING ANOTHER ROUND OF WIDESPREAD LIGHT SNOW TO THE AREA LATE
MONDAY AND MONDAY NIGHT... FOLLOWED BY A SIGNIFICANT WARMUP FOR
TUESDAY AND ESPECIALLY WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE FOR WINTER WEATHER ADVISORIES. HAVE ISSUED WINTER WEATHER
ADVISORIES FOR MOST OF THE CWA...WITH THE GREATEST AMOUNTS EAST OF
LAKE ONTARIO...WHERE 4 TO 8 INCHES OF ADDITIONAL SNOWFALL IS
EXPECTED. LESSER AMOUNTS ELSEWHERE...TAPERING DOWN TO AN ADDITIONAL
2 TO 5 INCHES WEST OF ROCHESTER. BECAUSE A SIGNIFICANT SNOW BURST
IS EXPECTED...AND BECAUSE A COUPLE INCHES OF SNOW HAS ALREADY
FALLEN IN THIS AREA...HAVE OPTED TO HANDLE THIS WITH AN ADVISORY.
ALSO...BECAUSE THE EVENT IS BEING INFLUENCED BY BOTH SYNOPTIC AND
LAKE FACTORS...HAVE CARRIED A WINTER WEATHER ADVISORY FOR ALL TO
KEEP OUR MESSAGE SIMPLE. THE MAJORITY OF THE EVENT WILL BE
SYNOPTIC...WITH THE EXCEPTION OF OSWEGO/NORTHERN CAYUGA/WAYNE
COUNTIES...WHERE SIGNIFICANT LAKE SNOWS WILL LINGER LATE TONIGHT
INTO MONDAY.
AS OF NOON...RADAR SHOWS A BAND OF SNOW EXTENDING NORTH OF THE
BUFFALO AND ROCHESTER METRO AREAS. THIS BAND HAS CONTINUED TO
WEAKEN OVER THE PAST COUPLE HOURS...AND IT WILL CONTINUE TO WEAKEN
THROUGH EARLY AFTERNOON. MODELS HAVE NOT HANDLED THIS BAND WELL
AT ALL...WITH THE LIKELY CAUSE A COMBINATION OF MID- LEVEL WARM
AIR ADVECTION AND LAKE EFFECT ENHANCEMENT. EXPECT MOISTURE FROM
THIS BAND TO ADVECT ACROSS LAKE ONTARIO...WHICH WILL LIKELY ENHANCE
SNOWFALL EAST OF LAKE ONTARIO...DESPITE MODEL QPFS.
MODELS ARE CONSISTENT IN BRINGING A SHORTWAVE ACROSS THE REGION
LATE AFTERNOON. THE HRRR AND 12Z RUNS OF THE NAM12/RGEM/GFS BRING A
DECENT SNOW BURST LATE AFTERNOON INTO THIS EVENING. QPFS ARE
GENERALLY BETWEEN .10 AND .25 WITH THIS...WHICH IS MARGINAL FOR
ADVISORIES. HOWEVER...GIVEN THE POTENTIAL SNOWFALL RATES...AND THE
ANTICIPATED FLUFF FACTOR OF THE SNOW...OPTED TO GO WITH THE
ADVISORY.
IMMEDIATELY FOLLOWING THE DEPARTURE OF THE SURFACE WAVE THIS
EVENING...A WESTERLY TO WEST-NORTHWESTERLY FLOW OF COLDER AIR WILL
ONCE AGAIN SET UP ACROSS THE LOWER LAKES...WITH 850 MB TEMPS
DROPPING FROM AROUND -10C/-11C EARLY THIS EVENING TO AROUND -14C
BY MIDNIGHT. THIS WILL TRIGGER A RENEWED ROUND OF LAKE SNOWS EAST
/EAST-SOUTHEAST OF BOTH LAKES. OFF LAKE ERIE...THE RELATIVELY
SHALLOW MOISTURE FIELD AND LOW CAPPING INVERSION HEIGHT OF 5 KFT
SHOULD HELP KEEP THE LAKE SNOWS FAIRLY MINIMAL IN NATURE EAST OF
THE LAKE...WHERE ABOUT 1 TO 3 INCHES OF FRESH ACCUMULATION WILL BE
POSSIBLE THROUGH THE END OF THE NIGHT. OFF LAKE ONTARIO...THINGS
WILL BE A DIFFERENT STORY AS A MUCH DEEPER MOISTURE
FIELD...STRONGER LIFT...AND A CAPPING INVERSION OF AROUND 9-10 KFT
SHOULD ALLOW FOR ANOTHER ROUND OF ADVISORY-CRITERIA SNOWS. THE
MAIN QUESTION AT THIS POINT IS EXACTLY WHERE THESE WILL BE...AS
THE MODELS CONTINUE TO SHOW SOME VARIATION IN THE EXACT LOCATION
OF THE LAKE SNOW BAND...RANGING FROM THE 00Z NAM`S DEPICTION OF A
BAND EAST-SOUTHEAST OF THE LAKE...TO THE 00Z RGEM`S TUG HILL
POSITIONING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
AT THE START OF THE PERIOD SOME LAKE EFFECT SNOW WILL PERSIST ON
MONDAY EAST OF THE LAKES WITH 850MB TEMPS BOTTOMING OUT AROUND -14C
DURING THE MORNING.
OFF LAKE ERIE...A SURFACE RIDGE WILL BUILD ACROSS THE LAKE DURING
THE MORNING AND DISRUPT/BACK THE LOW LEVEL FLOW AND ALSO DRY OUT THE
LOW LEVELS. THIS SHOULD BRING A QUICK END TO LAKE EFFECT WITH
LINGERING SCATTERED SNOW SHOWERS ACROSS THE WESTERN SOUTHERN TIER
LIFTING NORTH TOWARDS THE BUF SOUTHTOWNS AND FALLING APART WITH ONLY
VERY MINOR DUSTING TO AN INCH ACCUMULATIONS ON THE HILLS IN THE
EARLY MORNING.
OFF LAKE ONTARIO...CONDITIONS WILL STILL BE MORE FAVORABLE THROUGH
THE MORNING HOURS WITH LAKE INDUCED EQUILIBRIUM LEVELS AROUND 10K
FEET...DETERIORATING TO LESS THAN 7K FEET BY AFTERNOON AS THE
SURFACE RIDGE BUILDS ACROSS LAKE ONTARIO. THERE REMAINS SOME SPREAD
WITH BAND PLACEMENT IN THE LATEST 00Z MODEL SUITE WITH THE CANADIAN
GEM HOLDING THE LAKE EFFECT ACROSS NORTHERN OSWEGO COUNTY AND THE
SOUTHERN TUG HILL...WHILE THE NAM DROPS THE BAND INTO SOUTHERN
OSWEGO COUNTY AND EVEN CLIPS N.CAYUGA AND NE WAYNE COUNTY FOR
AWHILE. FOR NOW HAVE PLACED THE BAND ACROSS CENTRAL OSWEGO COUNTY
BUT THIS MAY NEED TO BE TWEAKED AS SHORT TERM MODEL GUIDANCE
CONVERGES ON A COMMON SOLUTION FOR BAND PLACEMENT. SYNOPTIC SCALE
MOISTURE IS DRYING OUT BY MONDAY MORNING...BUT MODERATE INSTABILITY
AND LONG FETCH SUGGEST THE POTENTIAL FOR SEVERAL MORE INCHES IN
PERSISTENT BANDS THROUGH THE FIRST HALF OF MONDAY. AN ADVISORY WILL
LIKELY BE NEEDED FOR THIS INTO MONDAY...BUT AS STATED IN THE NEAR
TERM DISCUSSION WE WILL WAIT UNTIL THE CURRENT ADVISORY EXPIRES
BEFORE RAISING A NEW ONE TO AVOID CONFUSION.
THE LAKE ONTARIO LAKE EFFECT WILL WEAKEN AND END MONDAY AFTERNOON AS
THE SURFACE RIDGE CROSSES THE LAKE AND DISRUPTS THE LOW LEVEL FLOW.
OUR ATTENTION THEN QUICKLY TURNS BACK TO THE SYNOPTIC SCALE. PAST
FEW RUNS OF THE GFS AND SREF HAVE BEEN CONSISTENT IN DEVELOPING AN
AREA OF LIGHT SNOW LATE MONDAY AFTERNOON ACROSS WESTERN NY...THEN
SPREADING EAST ACROSS THE REST OF THE AREA MONDAY NIGHT. THIS AREA
OF SNOW WILL BE SUPPORTED BY A MODERATE TO STRONG WARM ADVECTION
REGIME WITH AMPLE ISENTROPIC UPGLIDE AND MOISTURE CONVERGENCE ON THE
NOSE OF A 60 KNOT 700MB JET SUPPORTING A 3-5 HOUR PERIOD OF SNOW.
THE QUALITY OF DYNAMICS AND MOISTURE COMING TOGETHER SUGGEST THIS
MAY PRODUCE A GENERAL 1-3 INCH SNOW ACROSS MUCH OF THE REGION.
THE SNOW THAT FALLS OVER THE NEXT FEW DAYS WILL BE A THING OF THE
PAST BY MIDWEEK AS ANOTHER UNSEASONABLY STRONG WARM-UP ARRIVES
BEGINNING TUESDAY. IN FACT...FOLLOWING THE GENERAL SNOW MONDAY
EVENING TEMPERATURES WILL RISE OVERNIGHT IN THE MODERATE TO STRONG
WARM ADVECTION REGIME...AND WILL BE WELL ABOVE FREEZING ALREADY BY
TUESDAY MORNING FROM THE FINGER LAKES WESTWARD. ONGOING WARM
ADVECTION WILL SUPPORT HIGHS IN THE MID TO UPPER 40S ACROSS MUCH OF
WESTERN AND CENTRAL NY WITH A MAINLY DRY DAY AS THE WARM SECTOR
MIXES NORTHWARD.
THE WARM FRONT WILL HANG UP EAST OF LAKE ONTARIO WITH LIGHT SNOW
LINGERING ACROSS THE NORTH COUNTRY ON TUESDAY. MAY SEE A LITTLE MORE
MINOR ACCUMULATION TUESDAY MORNING...BUT BY AFTERNOON EVEN THERE THE
WARM AIR WILL BEGIN TO WIN OUT WITH TEMPERATURES RISING ABOVE
FREEZING AND ALLOWING RAIN TO MIX IN WITH ANY LEFTOVER LIGHT SNOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT THE HEART OF THE WARM SECTOR WILL BUILD INTO THE LOWER
LAKES AS A SURFACE LOW MOVES FROM THE UPPER LAKES TO WESTERN QUEBEC
BY WEDNESDAY MORNING. THIS WILL SUPPORT A VERY MILD NIGHT WITH MANY
LOCATIONS NOT DROPPING OUT OF THE 40S...WITH MID 30S EAST OF LAKE
ONTARIO. THE APPROACH OF THE MID LEVEL TROUGH AND BELT OF ENHANCED
LOW/MID LEVEL FLOW WILL SUPPORT INCREASING LARGE SCALE FORCING FOR
ASCENT...WITH RAIN CHANCES GOING UP OVERNIGHT. THE SURFACE COLD
FRONT WILL CROSS THE REGION WEDNESDAY MORNING WITH VERY MILD TEMPS
JUST AHEAD GIVING WAY TO FALLING TEMPS BY AFTERNOON. BEST RAIN
CHANCES WILL BE EARLY...WITH DRYING EXPECTED BY AFTERNOON IF THE
CURRENT MODEL TIMING HOLDS.
COLD ADVECTION BEHIND THE SYSTEM WILL BRING TEMPS DOWN...BUT STILL
ABOVE CLIMO FOR THURSDAY WITH A FEW LIGHT SNOW SHOWERS POSSIBLE EAST
OF THE LAKES.
LATER THURSDAY INTO NEXT WEEKEND FORECAST UNCERTAINTY QUICKLY
INCREASES WITH THE LATEST GFS AND ECMWF RAPIDLY BECOMING
DRAMATICALLY DIFFERENT IN THE SYNOPTIC DETAILS AND EVEN THE LARGE
SCALE PATTERN. THE GFS KEEPS A FLAT TROUGH ON THURSDAY WITH A
GRADUAL AMPLIFICATION NEXT WEEKEND WHICH WOULD TAKE A SOUTHERN
STREAM LOW TOO FAR SOUTH AND EAST TO HAVE MUCH IMPACT ON THE LOWER
LAKES...RESULTING IN A TURN TO COLDER TEMPS NEXT WEEKEND BUT MAINLY
DRY. THE ECMWF ON THE OTHER HAND BRINGS A STRONGER SOUTHERN STREAM
LOW OVER THE LOWER LAKES LATE THURSDAY AND THURSDAY NIGHT WITH RAIN
AND WET SNOW CHANGING TO SNOW. THIS IS FOLLOWED BY A MORE
SIGNIFICANT TROUGH AMPLIFICATION BY SATURDAY NIGHT AND SUNDAY WITH
SOME SEMBLANCE OF ANOTHER OHIO VALLEY LOW BRINGING A GENERAL
SNOWFALL TO THE REGION FOR THE SECOND HALF OF THE WEEKEND.
GIVEN THE LACK OF MODEL CONSISTENCY...WILL STICK CLOSE TO THE
PREVIOUS FORECAST FOR LATE IN THE WEEK INTO NEXT WEEKEND. THE
COMPLEXITY OF THE PATTERN EVOLUTION LATE NEXT WEEK WILL LIKELY
RESULT IN ONGOING MODEL UNCERTAINTY FOR SEVERAL MORE DAYS UNTIL
MODELS BEGIN TO CONVERGE ON A COMMON SOLUTION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FOR THE 18Z TAFS...EXPECT VARIABLE CONDITIONS THROUGH ABOUT 21Z.
BY LARGE...IT SHOULD BE PREDOMINANTLY MVFR-VFR CONDITIONS.
HOWEVER...PERIODIC LAKE SNOWS WILL DRASTICALLY LOWER CONDITIONS AT
BUF/IAG/ART AT TIMES. AT 1230 PM...RADAR SHOWS A FAIRLY INTENSE
LAKE EFFECT BAND JUST NORTH OF ART...WHICH WILL LIKELY MEANDER
JUST ENOUGH SOUTH TO IMPACT THE TERMINAL AT TIMES THROUGH MID-AFTERNOON.
AFTER THIS...A SIGNIFICANT SHORTWAVE WILL MOVE ACROSS. THIS WILL
LIKELY PRODUCE A PERIOD OF LIFR CONDITIONS AT ALL SITES...WHICH
WILL LAST A COUPLE HOURS. VSBY BELOW 1/2SM IS LIKELY.
CONDITIONS WILL IMPROVE WITH THE EXIT OF THIS SYSTEM...WITH MAINLY
MVFR CONDITIONS OVERNIGHT. THE EXCEPTION WILL BE IN LAKE EFFECT
BANDS...BUT IN THE WNW FLOW THESE TYPICALLY HAVE ONLY MINOR
IMPACTS ON TAF SITES...THOUGH LOCAL AND BRIEF PERIODS OF LOWER
CONDITIONS ARE POSSIBLE.
OUTLOOK...
MONDAY NIGHT...IFR WITH LIGHT SNOW LIKELY.
TUESDAY...IFR WITH LIGHT SNOW LIKELY EAST OF LAKE ONTARIO...
ELSEWHERE IMPROVING TO MAINLY VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
FRIDAY...VFR.
&&
.MARINE...
MODERATELY STRONG SOUTHWESTERLIES AND WESTERLIES WILL CONTINUE
ACROSS THE LOWER LAKES REGION RIGHT INTO MONDAY. THIS WILL RESULT
IN CONDITIONS REMAINING SOLIDLY IN THE SMALL CRAFT ADVISORY RANGE
THROUGH MONDAY MORNING...BEFORE AN APPROACHING WARM FRONT RESULTS
IN DIMINISHING WINDS MONDAY AFTERNOON AND EVENING.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ007-
008.
WINTER WEATHER ADVISORY UNTIL NOON EST MONDAY FOR NYZ004>006.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ001>003-010-011.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ012-019-020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...JJR
NEAR TERM...APFFEL/JJR
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1210 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING WAVE OF LOW PRESSURE WILL CROSS THE REGION LATE
AFTERNOON THROUGH THIS EVENING...BRINGING A BRIEF PERIOD OF HEAVY
SNOW TO MOST LOCATIONS. THIS WILL BE FOLLOWED BY LAKE SNOWS EAST
OF THE LAKES TONIGHT AS A WESTERLY FLOW OF BRIEFLY COLDER AIR
SPREADS ACROSS THE LOWER LAKES. AN APPROACHING WARM FRONT WILL
THEN BRING ANOTHER ROUND OF WIDESPREAD LIGHT SNOW TO THE AREA LATE
MONDAY AND MONDAY NIGHT... FOLLOWED BY A SIGNIFICANT WARMUP FOR
TUESDAY AND ESPECIALLY WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE FOR WINTER WEATHER ADVISORIES. HAVE ISSUED WINTER WEATHER
ADVISORIES FOR MOST OF THE CWA...WITH THE GREATEST AMOUNTS EAST OF
LAKE ONTARIO...WHERE 4 TO 8 INCHES OF ADDITIONAL SNOWFALL IS
EXPECTED. LESSER AMOUNTS ELSEWHERE...TAPERING DOWN TO AN ADDITIONAL
2 TO 5 INCHES WEST OF ROCHESTER. BECAUSE A SIGNIFICANT SNOW BURST
IS EXPECTED...AND BECAUSE A COUPLE INCHES OF SNOW HAS ALREADY
FALLEN IN THIS AREA...HAVE OPTED TO HANDLE THIS WITH AN ADVISORY.
ALSO...BECAUSE THE EVENT IS BEING INFLUENCED BY BOTH SYNOPTIC AND
LAKE FACTORS...HAVE CARRIED A WINTER WEATHER ADVISORY FOR ALL TO
KEEP OUR MESSAGE SIMPLE. THE MAJORITY OF THE EVENT WILL BE
SYNOPTIC...WITH THE EXCEPTION OF OSWEGO/NORTHERN CAYUGA/WAYNE
COUNTIES...WHERE SIGNIFICANT LAKE SNOWS WILL LINGER LATE TONIGHT
INTO MONDAY.
AS OF NOON...RADAR SHOWS A BAND OF SNOW EXTENDING NORTH OF THE
BUFFALO AND ROCHESTER METRO AREAS. THIS BAND HAS CONTINUED TO
WEAKEN OVER THE PAST COUPLE HOURS...AND IT WILL CONTINUE TO WEAKEN
THROUGH EARLY AFTERNOON. MODELS HAVE NOT HANDLED THIS BAND WELL
AT ALL...WITH THE LIKELY CAUSE A COMBINATION OF MID- LEVEL WARM
AIR ADVECTION AND LAKE EFFECT ENHANCEMENT. EXPECT MOISTURE FROM
THIS BAND TO ADVECT ACROSS LAKE ONTARIO...WHICH WILL LIKELY ENHANCE
SNOWFALL EAST OF LAKE ONTARIO...DESPITE MODEL QPFS.
MODELS ARE CONSISTENT IN BRINGING A SHORTWAVE ACROSS THE REGION
LATE AFTERNOON. THE HRRR AND 12Z RUNS OF THE NAM12/RGEM/GFS BRING A
DECENT SNOW BURST LATE AFTERNOON INTO THIS EVENING. QPFS ARE
GENERALLY BETWEEN .10 AND .25 WITH THIS...WHICH IS MARGINAL FOR
ADVISORIES. HOWEVER...GIVEN THE POTENTIAL SNOWFALL RATES...AND THE
ANTICIPATED FLUFF FACTOR OF THE SNOW...OPTED TO GO WITH THE
ADVISORY.
IMMEDIATELY FOLLOWING THE DEPARTURE OF THE SURFACE WAVE THIS
EVENING...A WESTERLY TO WEST-NORTHWESTERLY FLOW OF COLDER AIR WILL
ONCE AGAIN SET UP ACROSS THE LOWER LAKES...WITH 850 MB TEMPS
DROPPING FROM AROUND -10C/-11C EARLY THIS EVENING TO AROUND -14C
BY MIDNIGHT. THIS WILL TRIGGER A RENEWED ROUND OF LAKE SNOWS EAST
/EAST-SOUTHEAST OF BOTH LAKES. OFF LAKE ERIE...THE RELATIVELY
SHALLOW MOISTURE FIELD AND LOW CAPPING INVERSION HEIGHT OF 5 KFT
SHOULD HELP KEEP THE LAKE SNOWS FAIRLY MINIMAL IN NATURE EAST OF
THE LAKE...WHERE ABOUT 1 TO 3 INCHES OF FRESH ACCUMULATION WILL BE
POSSIBLE THROUGH THE END OF THE NIGHT. OFF LAKE ONTARIO...THINGS
WILL BE A DIFFERENT STORY AS A MUCH DEEPER MOISTURE
FIELD...STRONGER LIFT...AND A CAPPING INVERSION OF AROUND 9-10 KFT
SHOULD ALLOW FOR ANOTHER ROUND OF ADVISORY-CRITERIA SNOWS. THE
MAIN QUESTION AT THIS POINT IS EXACTLY WHERE THESE WILL BE...AS
THE MODELS CONTINUE TO SHOW SOME VARIATION IN THE EXACT LOCATION
OF THE LAKE SNOW BAND...RANGING FROM THE 00Z NAM`S DEPICTION OF A
BAND EAST-SOUTHEAST OF THE LAKE...TO THE 00Z RGEM`S TUG HILL
POSITIONING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
AT THE START OF THE PERIOD SOME LAKE EFFECT SNOW WILL PERSIST ON
MONDAY EAST OF THE LAKES WITH 850MB TEMPS BOTTOMING OUT AROUND -14C
DURING THE MORNING.
OFF LAKE ERIE...A SURFACE RIDGE WILL BUILD ACROSS THE LAKE DURING
THE MORNING AND DISRUPT/BACK THE LOW LEVEL FLOW AND ALSO DRY OUT THE
LOW LEVELS. THIS SHOULD BRING A QUICK END TO LAKE EFFECT WITH
LINGERING SCATTERED SNOW SHOWERS ACROSS THE WESTERN SOUTHERN TIER
LIFTING NORTH TOWARDS THE BUF SOUTHTOWNS AND FALLING APART WITH ONLY
VERY MINOR DUSTING TO AN INCH ACCUMULATIONS ON THE HILLS IN THE
EARLY MORNING.
OFF LAKE ONTARIO...CONDITIONS WILL STILL BE MORE FAVORABLE THROUGH
THE MORNING HOURS WITH LAKE INDUCED EQUILIBRIUM LEVELS AROUND 10K
FEET...DETERIORATING TO LESS THAN 7K FEET BY AFTERNOON AS THE
SURFACE RIDGE BUILDS ACROSS LAKE ONTARIO. THERE REMAINS SOME SPREAD
WITH BAND PLACEMENT IN THE LATEST 00Z MODEL SUITE WITH THE CANADIAN
GEM HOLDING THE LAKE EFFECT ACROSS NORTHERN OSWEGO COUNTY AND THE
SOUTHERN TUG HILL...WHILE THE NAM DROPS THE BAND INTO SOUTHERN
OSWEGO COUNTY AND EVEN CLIPS N.CAYUGA AND NE WAYNE COUNTY FOR
AWHILE. FOR NOW HAVE PLACED THE BAND ACROSS CENTRAL OSWEGO COUNTY
BUT THIS MAY NEED TO BE TWEAKED AS SHORT TERM MODEL GUIDANCE
CONVERGES ON A COMMON SOLUTION FOR BAND PLACEMENT. SYNOPTIC SCALE
MOISTURE IS DRYING OUT BY MONDAY MORNING...BUT MODERATE INSTABILITY
AND LONG FETCH SUGGEST THE POTENTIAL FOR SEVERAL MORE INCHES IN
PERSISTENT BANDS THROUGH THE FIRST HALF OF MONDAY. AN ADVISORY WILL
LIKELY BE NEEDED FOR THIS INTO MONDAY...BUT AS STATED IN THE NEAR
TERM DISCUSSION WE WILL WAIT UNTIL THE CURRENT ADVISORY EXPIRES
BEFORE RAISING A NEW ONE TO AVOID CONFUSION.
THE LAKE ONTARIO LAKE EFFECT WILL WEAKEN AND END MONDAY AFTERNOON AS
THE SURFACE RIDGE CROSSES THE LAKE AND DISRUPTS THE LOW LEVEL FLOW.
OUR ATTENTION THEN QUICKLY TURNS BACK TO THE SYNOPTIC SCALE. PAST
FEW RUNS OF THE GFS AND SREF HAVE BEEN CONSISTENT IN DEVELOPING AN
AREA OF LIGHT SNOW LATE MONDAY AFTERNOON ACROSS WESTERN NY...THEN
SPREADING EAST ACROSS THE REST OF THE AREA MONDAY NIGHT. THIS AREA
OF SNOW WILL BE SUPPORTED BY A MODERATE TO STRONG WARM ADVECTION
REGIME WITH AMPLE ISENTROPIC UPGLIDE AND MOISTURE CONVERGENCE ON THE
NOSE OF A 60 KNOT 700MB JET SUPPORTING A 3-5 HOUR PERIOD OF SNOW.
THE QUALITY OF DYNAMICS AND MOISTURE COMING TOGETHER SUGGEST THIS
MAY PRODUCE A GENERAL 1-3 INCH SNOW ACROSS MUCH OF THE REGION.
THE SNOW THAT FALLS OVER THE NEXT FEW DAYS WILL BE A THING OF THE
PAST BY MIDWEEK AS ANOTHER UNSEASONABLY STRONG WARM-UP ARRIVES
BEGINNING TUESDAY. IN FACT...FOLLOWING THE GENERAL SNOW MONDAY
EVENING TEMPERATURES WILL RISE OVERNIGHT IN THE MODERATE TO STRONG
WARM ADVECTION REGIME...AND WILL BE WELL ABOVE FREEZING ALREADY BY
TUESDAY MORNING FROM THE FINGER LAKES WESTWARD. ONGOING WARM
ADVECTION WILL SUPPORT HIGHS IN THE MID TO UPPER 40S ACROSS MUCH OF
WESTERN AND CENTRAL NY WITH A MAINLY DRY DAY AS THE WARM SECTOR
MIXES NORTHWARD.
THE WARM FRONT WILL HANG UP EAST OF LAKE ONTARIO WITH LIGHT SNOW
LINGERING ACROSS THE NORTH COUNTRY ON TUESDAY. MAY SEE A LITTLE MORE
MINOR ACCUMULATION TUESDAY MORNING...BUT BY AFTERNOON EVEN THERE THE
WARM AIR WILL BEGIN TO WIN OUT WITH TEMPERATURES RISING ABOVE
FREEZING AND ALLOWING RAIN TO MIX IN WITH ANY LEFTOVER LIGHT SNOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT THE HEART OF THE WARM SECTOR WILL BUILD INTO THE LOWER
LAKES AS A SURFACE LOW MOVES FROM THE UPPER LAKES TO WESTERN QUEBEC
BY WEDNESDAY MORNING. THIS WILL SUPPORT A VERY MILD NIGHT WITH MANY
LOCATIONS NOT DROPPING OUT OF THE 40S...WITH MID 30S EAST OF LAKE
ONTARIO. THE APPROACH OF THE MID LEVEL TROUGH AND BELT OF ENHANCED
LOW/MID LEVEL FLOW WILL SUPPORT INCREASING LARGE SCALE FORCING FOR
ASCENT...WITH RAIN CHANCES GOING UP OVERNIGHT. THE SURFACE COLD
FRONT WILL CROSS THE REGION WEDNESDAY MORNING WITH VERY MILD TEMPS
JUST AHEAD GIVING WAY TO FALLING TEMPS BY AFTERNOON. BEST RAIN
CHANCES WILL BE EARLY...WITH DRYING EXPECTED BY AFTERNOON IF THE
CURRENT MODEL TIMING HOLDS.
COLD ADVECTION BEHIND THE SYSTEM WILL BRING TEMPS DOWN...BUT STILL
ABOVE CLIMO FOR THURSDAY WITH A FEW LIGHT SNOW SHOWERS POSSIBLE EAST
OF THE LAKES.
LATER THURSDAY INTO NEXT WEEKEND FORECAST UNCERTAINTY QUICKLY
INCREASES WITH THE LATEST GFS AND ECMWF RAPIDLY BECOMING
DRAMATICALLY DIFFERENT IN THE SYNOPTIC DETAILS AND EVEN THE LARGE
SCALE PATTERN. THE GFS KEEPS A FLAT TROUGH ON THURSDAY WITH A
GRADUAL AMPLIFICATION NEXT WEEKEND WHICH WOULD TAKE A SOUTHERN
STREAM LOW TOO FAR SOUTH AND EAST TO HAVE MUCH IMPACT ON THE LOWER
LAKES...RESULTING IN A TURN TO COLDER TEMPS NEXT WEEKEND BUT MAINLY
DRY. THE ECMWF ON THE OTHER HAND BRINGS A STRONGER SOUTHERN STREAM
LOW OVER THE LOWER LAKES LATE THURSDAY AND THURSDAY NIGHT WITH RAIN
AND WET SNOW CHANGING TO SNOW. THIS IS FOLLOWED BY A MORE
SIGNIFICANT TROUGH AMPLIFICATION BY SATURDAY NIGHT AND SUNDAY WITH
SOME SEMBLANCE OF ANOTHER OHIO VALLEY LOW BRINGING A GENERAL
SNOWFALL TO THE REGION FOR THE SECOND HALF OF THE WEEKEND.
GIVEN THE LACK OF MODEL CONSISTENCY...WILL STICK CLOSE TO THE
PREVIOUS FORECAST FOR LATE IN THE WEEK INTO NEXT WEEKEND. THE
COMPLEXITY OF THE PATTERN EVOLUTION LATE NEXT WEEK WILL LIKELY
RESULT IN ONGOING MODEL UNCERTAINTY FOR SEVERAL MORE DAYS UNTIL
MODELS BEGIN TO CONVERGE ON A COMMON SOLUTION.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
FOR THE 15Z AMD...EXPECT VARIABLE CONDITIONS THROUGH MID-
AFTERNOON. PREDOMINANTLY MVFR-VFR CONDITIONS ARE EXPECTED.
HOWEVER...PERIODIC LAKE SNOWS WILL DRASTICALLY LOWER CONDITIONS AT
BUF/IAG/ART AT TIMES THIS MORNING. TAFS BASICALLY FOLLOWING RADAR
TRENDS DURING THIS TIME...WITH PERIODS OF VSBY BELOW 1SM POSSIBLE
AT THESE TAF LOCATIONS.
AFTER 20Z...A SIGNIFICANT SHORTWAVE WILL MOVE ACROSS. THIS WILL
LIKELY PRODUCE A PERIOD OF LIFR CONDITIONS AT ALL SITES...WHICH
WILL LAST A COUPLE HOURS. VSBY BELOW 1/2SM IS LIKELY.
CONDITIONS WILL IMPROVE WITH THE EXIT OF THIS SHORTWAVE...WITH
MAINLY MVFR CONDITIONS OVERNIGHT. THE EXCEPTION WILL BE IN LAKE
EFFECT BANDS...BUT IN THE WNW FLOW THESE TYPICALLY HAVE ONLY MINOR
IMPACTS ON TAF SITES...THOUGH LOCAL AND BRIEF PERIODS OF LOWER
CONDITIONS ARE POSSIBLE.
OUTLOOK...
MONDAY...MVFR/IFR IN DIMINISHING LAKE SNOWS EAST OF THE LAKES...
MAINLY VFR ELSEWHERE.
MONDAY NIGHT...IFR WITH LIGHT SNOW LIKELY.
TUESDAY...IFR WITH LIGHT SNOW LIKELY EAST OF LAKE ONTARIO...
ELSEWHERE IMPROVING TO MAINLY VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
MODERATELY STRONG SOUTHWESTERLIES AND WESTERLIES WILL CONTINUE
ACROSS THE LOWER LAKES REGION RIGHT INTO MONDAY. THIS WILL RESULT
IN CONDITIONS REMAINING SOLIDLY IN THE SMALL CRAFT ADVISORY RANGE
THROUGH MONDAY MORNING...BEFORE AN APPROACHING WARM FRONT RESULTS
IN DIMINISHING WINDS MONDAY AFTERNOON AND EVENING.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ007-
008.
WINTER WEATHER ADVISORY UNTIL NOON EST MONDAY FOR NYZ004>006.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ001>003-010-011.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ012-019-020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...JJR
NEAR TERM...APFFEL/JJR
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...APFFEL/JJR
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1023 AM EST SUN JAN 29 2012
.SYNOPSIS...
ANOTHER FAST MOVING WAVE OF LOW PRESSURE WILL TRACK ACROSS THE
REGION THIS AFTERNOON AND EVENING...BRINGING A WIDESPREAD LIGHT
SNOWFALL...FOLLOWED BY RENEWED LAKE SNOWS EAST OF THE LAKES TONIGHT
AS A WESTERLY FLOW OF BRIEFLY COLDER AIR SPREADS ACROSS THE LOWER
LAKES. AN APPROACHING WARM FRONT WILL THEN BRING ANOTHER ROUND OF
WIDESPREAD LIGHT SNOW TO THE AREA LATE MONDAY AND MONDAY NIGHT...
FOLLOWED BY A SIGNIFICANT WARMUP FOR TUESDAY AND ESPECIALLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM...RADAR SHOWS A BAND OF SNOW EXTENDING NORTH OF THE
BUFFALO AND ROCHESTER METRO AREAS. THIS BAND HAS BEEN QUITE
IMPRESSIVE AT TIMES THIS MORNING...BRINGING A QUICK TWO INCHES OF
SNOW TO SOME LOCATIONS. THE BAND HAS SINCE WEAKENED A BIT. MODELS
HAVE NOT HANDLED THIS BAND WELL AT ALL...WITH THE LIKELY CAUSE A
COMBINATION OF MID-LEVEL WARM AIR ADVECTION AND LAKE EFFECT
ENHANCEMENT. IR SHOWS LESS MOISTURE IN THE MID-LEVELS
UPSTREAM...WHICH SUGGESTS THAT THE BAND WILL CONTINUE TO WEAKEN.
THIS SAID...WILL MAINTAIN LIKELY POPS BUFFALO NORTHWARD THROUGH
MID-AFTERNOON...WITH AN ADDITIONAL INCH OR TWO POSSIBLE FROM THIS
BAND THROUGH MID-AFTERNOON. MEANWHILE...OFF LAKE ONTARIO...THE
LAKE EFFECT BAND PROMPTING ADVISORIES HAS DISSIPATED...AND THIS
ADVISORY HAS BEEN ALLOWED TO EXPIRE. DESPITE THIS...ADDITIONAL
SNOW IS ON THE WAY...WITH ANOTHER HEADLINE POSSIBLE IN THE NEAR
FUTURE. AN ADDITIONAL CONCERN FOR THIS AREA IS AS MOISTURE FROM
THE LAKE ERIE BAND WORKS ACROSS LAKE ONTARIO...THERE MAY BE
ADDITIONAL ENHANCEMENT THIS AFTERNOON. SEE DISCUSSION BELOW.
MODELS ARE CONSISTENT IN BRINGING A SHORTWAVE ACROSS THE REGION
LATE AFTERNOON. THE HRRR HAS JOINED THE RGEM/NAM12 OF BRINGING A
DECENT SNOW BURST LATE AFTERNOON INTO THIS EVENING. QPFS ARE
GENERALLY BETWEEN .10 AND .25 WITH THIS...WHICH IS MARGINAL FOR
ADVISORIES. HOWEVER...GIVEN THE POTENTIAL SNOWFALL RATES...WILL
CONSIDER AN ADVISORY FOR MARGINAL AMOUNTS...BASED ON IMPACT. THERE
ALSO WILL BE LAKE EFFECT AFTER THIS...WHICH FURTHER COMPLICATES
THE ISSUE. WOULD LIKE TO LOOK AT 12Z RUNS BEFORE MAKING HEADLINE
DECISIONS...BUT WILL LIKELY MAKE HEADLINE DECISIONS BEFORE THE
SCHEDULED 300 PM UPDATE.
IMMEDIATELY FOLLOWING THE DEPARTURE OF THE SURFACE WAVE THIS
EVENING...A WESTERLY TO WEST-NORTHWESTERLY FLOW OF COLDER AIR WILL
ONCE AGAIN SET UP ACROSS THE LOWER LAKES...WITH 850 MB TEMPS
DROPPING FROM AROUND -10C/-11C EARLY THIS EVENING TO AROUND -14C
BY MIDNIGHT. THIS WILL TRIGGER A RENEWED ROUND OF LAKE SNOWS EAST
/EAST-SOUTHEAST OF BOTH LAKES. OFF LAKE ERIE...THE RELATIVELY
SHALLOW MOISTURE FIELD AND LOW CAPPING INVERSION HEIGHT OF 5 KFT
SHOULD HELP KEEP THE LAKE SNOWS FAIRLY MINIMAL IN NATURE EAST OF
THE LAKE...WHERE ABOUT 1 TO 3 INCHES OF FRESH ACCUMULATION WILL BE
POSSIBLE THROUGH THE END OF THE NIGHT. OFF LAKE ONTARIO...THINGS
WILL BE A DIFFERENT STORY AS A MUCH DEEPER MOISTURE
FIELD...STRONGER LIFT...AND A CAPPING INVERSION OF AROUND 9-10 KFT
SHOULD ALLOW FOR ANOTHER ROUND OF ADVISORY-CRITERIA SNOWS. THE
MAIN QUESTION AT THIS POINT IS EXACTLY WHERE THESE WILL BE...AS
THE MODELS CONTINUE TO SHOW SOME VARIATION IN THE EXACT LOCATION
OF THE LAKE SNOW BAND...RANGING FROM THE 00Z NAM`S DEPICTION OF A
BAND EAST-SOUTHEAST OF THE LAKE...TO THE 00Z RGEM`S TUG HILL
POSITIONING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
AT THE START OF THE PERIOD SOME LAKE EFFECT SNOW WILL PERSIST ON
MONDAY EAST OF THE LAKES WITH 850MB TEMPS BOTTOMING OUT AROUND -14C
DURING THE MORNING.
OFF LAKE ERIE...A SURFACE RIDGE WILL BUILD ACROSS THE LAKE DURING
THE MORNING AND DISRUPT/BACK THE LOW LEVEL FLOW AND ALSO DRY OUT THE
LOW LEVELS. THIS SHOULD BRING A QUICK END TO LAKE EFFECT WITH
LINGERING SCATTERED SNOW SHOWERS ACROSS THE WESTERN SOUTHERN TIER
LIFTING NORTH TOWARDS THE BUF SOUTHTOWNS AND FALLING APART WITH ONLY
VERY MINOR DUSTING TO AN INCH ACCUMULATIONS ON THE HILLS IN THE
EARLY MORNING.
OFF LAKE ONTARIO...CONDITIONS WILL STILL BE MORE FAVORABLE THROUGH
THE MORNING HOURS WITH LAKE INDUCED EQUILIBRIUM LEVELS AROUND 10K
FEET...DETERIORATING TO LESS THAN 7K FEET BY AFTERNOON AS THE
SURFACE RIDGE BUILDS ACROSS LAKE ONTARIO. THERE REMAINS SOME SPREAD
WITH BAND PLACEMENT IN THE LATEST 00Z MODEL SUITE WITH THE CANADIAN
GEM HOLDING THE LAKE EFFECT ACROSS NORTHERN OSWEGO COUNTY AND THE
SOUTHERN TUG HILL...WHILE THE NAM DROPS THE BAND INTO SOUTHERN
OSWEGO COUNTY AND EVEN CLIPS N.CAYUGA AND NE WAYNE COUNTY FOR
AWHILE. FOR NOW HAVE PLACED THE BAND ACROSS CENTRAL OSWEGO COUNTY
BUT THIS MAY NEED TO BE TWEAKED AS SHORT TERM MODEL GUIDANCE
CONVERGES ON A COMMON SOLUTION FOR BAND PLACEMENT. SYNOPTIC SCALE
MOISTURE IS DRYING OUT BY MONDAY MORNING...BUT MODERATE INSTABILITY
AND LONG FETCH SUGGEST THE POTENTIAL FOR SEVERAL MORE INCHES IN
PERSISTENT BANDS THROUGH THE FIRST HALF OF MONDAY. AN ADVISORY WILL
LIKELY BE NEEDED FOR THIS INTO MONDAY...BUT AS STATED IN THE NEAR
TERM DISCUSSION WE WILL WAIT UNTIL THE CURRENT ADVISORY EXPIRES
BEFORE RAISING A NEW ONE TO AVOID CONFUSION.
THE LAKE ONTARIO LAKE EFFECT WILL WEAKEN AND END MONDAY AFTERNOON AS
THE SURFACE RIDGE CROSSES THE LAKE AND DISRUPTS THE LOW LEVEL FLOW.
OUR ATTENTION THEN QUICKLY TURNS BACK TO THE SYNOPTIC SCALE. PAST
FEW RUNS OF THE GFS AND SREF HAVE BEEN CONSISTENT IN DEVELOPING AN
AREA OF LIGHT SNOW LATE MONDAY AFTERNOON ACROSS WESTERN NY...THEN
SPREADING EAST ACROSS THE REST OF THE AREA MONDAY NIGHT. THIS AREA
OF SNOW WILL BE SUPPORTED BY A MODERATE TO STRONG WARM ADVECTION
REGIME WITH AMPLE ISENTROPIC UPGLIDE AND MOISTURE CONVERGENCE ON THE
NOSE OF A 60 KNOT 700MB JET SUPPORTING A 3-5 HOUR PERIOD OF SNOW.
THE QUALITY OF DYNAMICS AND MOISTURE COMING TOGETHER SUGGEST THIS
MAY PRODUCE A GENERAL 1-3 INCH SNOW ACROSS MUCH OF THE REGION.
THE SNOW THAT FALLS OVER THE NEXT FEW DAYS WILL BE A THING OF THE
PAST BY MIDWEEK AS ANOTHER UNSEASONABLY STRONG WARM-UP ARRIVES
BEGINNING TUESDAY. IN FACT...FOLLOWING THE GENERAL SNOW MONDAY
EVENING TEMPERATURES WILL RISE OVERNIGHT IN THE MODERATE TO STRONG
WARM ADVECTION REGIME...AND WILL BE WELL ABOVE FREEZING ALREADY BY
TUESDAY MORNING FROM THE FINGER LAKES WESTWARD. ONGOING WARM
ADVECTION WILL SUPPORT HIGHS IN THE MID TO UPPER 40S ACROSS MUCH OF
WESTERN AND CENTRAL NY WITH A MAINLY DRY DAY AS THE WARM SECTOR
MIXES NORTHWARD.
THE WARM FRONT WILL HANG UP EAST OF LAKE ONTARIO WITH LIGHT SNOW
LINGERING ACROSS THE NORTH COUNTRY ON TUESDAY. MAY SEE A LITTLE MORE
MINOR ACCUMULATION TUESDAY MORNING...BUT BY AFTERNOON EVEN THERE THE
WARM AIR WILL BEGIN TO WIN OUT WITH TEMPERATURES RISING ABOVE
FREEZING AND ALLOWING RAIN TO MIX IN WITH ANY LEFTOVER LIGHT SNOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT THE HEART OF THE WARM SECTOR WILL BUILD INTO THE LOWER
LAKES AS A SURFACE LOW MOVES FROM THE UPPER LAKES TO WESTERN QUEBEC
BY WEDNESDAY MORNING. THIS WILL SUPPORT A VERY MILD NIGHT WITH MANY
LOCATIONS NOT DROPPING OUT OF THE 40S...WITH MID 30S EAST OF LAKE
ONTARIO. THE APPROACH OF THE MID LEVEL TROUGH AND BELT OF ENHANCED
LOW/MID LEVEL FLOW WILL SUPPORT INCREASING LARGE SCALE FORCING FOR
ASCENT...WITH RAIN CHANCES GOING UP OVERNIGHT. THE SURFACE COLD
FRONT WILL CROSS THE REGION WEDNESDAY MORNING WITH VERY MILD TEMPS
JUST AHEAD GIVING WAY TO FALLING TEMPS BY AFTERNOON. BEST RAIN
CHANCES WILL BE EARLY...WITH DRYING EXPECTED BY AFTERNOON IF THE
CURRENT MODEL TIMING HOLDS.
COLD ADVECTION BEHIND THE SYSTEM WILL BRING TEMPS DOWN...BUT STILL
ABOVE CLIMO FOR THURSDAY WITH A FEW LIGHT SNOW SHOWERS POSSIBLE EAST
OF THE LAKES.
LATER THURSDAY INTO NEXT WEEKEND FORECAST UNCERTAINTY QUICKLY
INCREASES WITH THE LATEST GFS AND ECMWF RAPIDLY BECOMING
DRAMATICALLY DIFFERENT IN THE SYNOPTIC DETAILS AND EVEN THE LARGE
SCALE PATTERN. THE GFS KEEPS A FLAT TROUGH ON THURSDAY WITH A
GRADUAL AMPLIFICATION NEXT WEEKEND WHICH WOULD TAKE A SOUTHERN
STREAM LOW TOO FAR SOUTH AND EAST TO HAVE MUCH IMPACT ON THE LOWER
LAKES...RESULTING IN A TURN TO COLDER TEMPS NEXT WEEKEND BUT MAINLY
DRY. THE ECMWF ON THE OTHER HAND BRINGS A STRONGER SOUTHERN STREAM
LOW OVER THE LOWER LAKES LATE THURSDAY AND THURSDAY NIGHT WITH RAIN
AND WET SNOW CHANGING TO SNOW. THIS IS FOLLOWED BY A MORE
SIGNIFICANT TROUGH AMPLIFICATION BY SATURDAY NIGHT AND SUNDAY WITH
SOME SEMBLANCE OF ANOTHER OHIO VALLEY LOW BRINGING A GENERAL
SNOWFALL TO THE REGION FOR THE SECOND HALF OF THE WEEKEND.
GIVEN THE LACK OF MODEL CONSISTENCY...WILL STICK CLOSE TO THE
PREVIOUS FORECAST FOR LATE IN THE WEEK INTO NEXT WEEKEND. THE
COMPLEXITY OF THE PATTERN EVOLUTION LATE NEXT WEEK WILL LIKELY
RESULT IN ONGOING MODEL UNCERTAINTY FOR SEVERAL MORE DAYS UNTIL
MODELS BEGIN TO CONVERGE ON A COMMON SOLUTION.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
FOR THE 15Z AMD...EXPECT VARIABLE CONDITIONS THROUGH MID-
AFTERNOON. PREDOMINANTLY MVFR-VFR CONDITIONS ARE EXPECTED.
HOWEVER...PERIODIC LAKE SNOWS WILL DRASTICALLY LOWER CONDITIONS AT
BUF/IAG/ART AT TIMES THIS MORNING. TAFS BASICALLY FOLLOWING RADAR
TRENDS DURING THIS TIME...WITH PERIODS OF VSBY BELOW 1SM POSSIBLE
AT THESE TAF LOCATIONS.
AFTER 20Z...A SIGNIFICANT SHORTWAVE WILL MOVE ACROSS. THIS WILL
LIKELY PRODUCE A PERIOD OF LIFR CONDITIONS AT ALL SITES...WHICH
WILL LAST A COUPLE HOURS. VSBY BELOW 1/2SM IS LIKELY.
CONDITIONS WILL IMPROVE WITH THE EXIT OF THIS SHORTWAVE...WITH
MAINLY MVFR CONDITIONS OVERNIGHT. THE EXCEPTION WILL BE IN LAKE
EFFECT BANDS...BUT IN THE WNW FLOW THESE TYPICALLY HAVE ONLY MINOR
IMPACTS ON TAF SITES...THOUGH LOCAL AND BRIEF PERIODS OF LOWER
CONDITIONS ARE POSSIBLE.
OUTLOOK...
MONDAY...MVFR/IFR IN DIMINISHING LAKE SNOWS EAST OF THE LAKES...
MAINLY VFR ELSEWHERE.
MONDAY NIGHT...IFR WITH LIGHT SNOW LIKELY.
TUESDAY...IFR WITH LIGHT SNOW LIKELY EAST OF LAKE ONTARIO...
ELSEWHERE IMPROVING TO MAINLY VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
MODERATELY STRONG SOUTHWESTERLIES AND WESTERLIES WILL CONTINUE
ACROSS THE LOWER LAKES REGION RIGHT INTO MONDAY. THIS WILL RESULT
IN CONDITIONS REMAINING SOLIDLY IN THE SMALL CRAFT ADVISORY RANGE
THROUGH MONDAY MORNING...BEFORE AN APPROACHING WARM FRONT RESULTS
IN DIMINISHING WINDS MONDAY AFTERNOON AND EVENING.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...JJR
NEAR TERM...APFFEL/JJR
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...APFFEL/JJR
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
259 AM EST SUN JAN 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...THEN ANOTHER
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST MONDAY
THROUGH WEDNESDAY. A FRONTAL BOUNDARY WILL SLOWLY MOVE THROUGH THE
AREA THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM SUN...MINOR UPDATE FOR CLOUD COVER WITH SHRT WV MOVING
THROUGH AREA LATER TONIGHT INTO SUN MORNING. MODERATE CAA URGE
DEVELOPING OVER AREA IN WAKE OF DRY COLD FRONT MOVING OFFSHORE WHILE
MID CLOUDS WITH UPR LVL FEATURE ARE SLOWER TO MOVE E. LATEST GDNC
INDICATES THIS ACTVTY MOVING ACROSS LATER TONIGHT INTO SUN MORNING.
MINOR ADJUSTMENTS FOR CURRENT TEMP TRENDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM/...
AS OF 3 PM SAT...STRONG HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE DEEP SOUTH AND SE STATES. COOLER CONDITIONS EXPECTED SUN WITH
N FLOW EARLY BEHIND THE FRONT...BECOMING W/SW IN THE AFTERNOON.
LOW LEVEL THICKNESS VALUES AND MOSTLY SUNNY SKIES SUPPORT HIGH
TEMPS IN THE 50S...MUCH CLOSER TO CLIMO NORMS FOR LATE JAN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
SFC HIGH PRES MOVES ACRS THE FCST AREA MONDAY UNDER ZONAL FLOW
ALOFT. PLENTIFUL SUNSHINE BUT WITH LIGHT WINDS/LIMITED MIXING
AND A LOW LEVEL THICKNESS TROF OVER THE AREA...WILL UNDERCUT
MOS TEMPERATURE GUIDANCE A FEW DEGS.
A STRENGTHENING LOW LEVEL RETURN FLOW WILL BRING MODERATING
TEMPERATURES AS ZONAL FLOW REMAINS DOMINANT WITH DRY WEATHER THRU
WED.
A DECENT MODEL CONCENSUS IS DEVELOPING FOR A WEAK BACK DOOR COLD
FRONT TO DROP INTO THE AREA LATE WED NIGHT/EARLY THU BUT
THEREAFTER LONGER RANGE DETERMINISTIC MODEL CONSISTENCY IS
LACKING. RELUCTANT TO MAKE WHOLESALE CHANGES FOR THE LATE WEEK
INTO EARLY NEXT WEEKEND UNTIL BETTER MODEL CONSISTENCY/CONTINUITY
CAN BE ESTABLISHED.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /06Z SUNDAY THROUGH 06Z MONDAY/
AS OF 1230 AM SUN...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
WINDS HAVE SHIFTED TO NW IN WAKE OF DRY FRONTAL PASSAGE AND MAY SEE
BRIEF PERIOD OF GUSTS TO 15-20KT NEXT FEW HOUR. SCT MID CLOUDS
MOVING ACROSS 09Z-12Z...OTRW CLEAR.
LONG TERM /MONDAY THROUGH THURSDAY/...
OUTSIDE OF THE USUAL LATE NIGHT AND EARLY MORNING GROUND FOG THAT
COULD CAUSE TEMPORARY REDUCTIONS IN VISIBILITIES...PREVAILING VFR
CONDITIONS ARE EXPECTED THROUGH WEDNESDAY AS HIGH PRESSURE
INFLUENCES THE WEATHER THROUGH WEDNESDAY. SCTD SHOWERS WITH THE
POSSIBILITY OF SUB VFR CONDITIONS LATER WED NIGHT INTO THU AS A
BACKDOOR COLD FRONT DROPS INTO THE REGION.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1230 AM SUN...NO CHANGES WITH UPDATE. CAA SURGE DEVELOPING AS
EXPECTED IN WAKE OF DRY FRONTAL PASSAGE.
/PREVIOUS DISCUSSION/
AS OF 10 PM SAT...FORECAST LOOKS TO BE ON TRACK. CURRENT OBS
ILLUSTRATE A WSWLY FLOW AROUND 5-10KTS WITH SEAS HOVERING AROUND 3FT
ACROSS THE COASTAL WATERS. WINDS HAVE BEEN GUSTING AOA 20KT TO THE W
BEHIND FRONT AND MDLS SHOW GUSTY WINDS DEVELOPING ALONG THE COAST
AFTER FROPA. BASED ON LATEST RUC13 AND LOCAL WRF MDL HAVE ADDED SCA
FOR ALBEMARLE SOUND AS BOTH SHOW BRIEF PD OF 20 TO 25 KTS LATER
TONIGHT. WINDS WILL BE FAIRLY QUICK TO DIMINISH MID SUNDAY MORNING
AS FRONT MOVES FURTHER OFFSHORE. N WINDS WILL BACK THROUGH THE DAY
AND BECOME W/NW IN THE AFTERNOON.
LONG TERM /MONDAY THROUGH THURSDAY/...
WINDS/SEAS WILL BE DECREASING MONDAY AS HIGH PRES BUILDS TOWARD
THE NC WATERS. THEREAFTER...A S/SW RETIRN FLOW WILL DEVELOP AND
STRENGTHEN AS HIGH PRES MOVES OFF THE COAST THEN BUILDS OFFSHORE.
WINDS MAY REACH NEAR SMALL CRAFT ADVISORY LEVELS BY WED AFTN AND
CONTINUE INTO WED NIGHT AHEAD OF A BACKDOOR COLD FRONT MOVING DOWN
THE MID ATLC COAST. LOW CONFIDENCE FORECAST FOR THURSDAY DUE TO
THE UNCERTAINTY OF THE SOUTHWARD EXTENT OF BACK DOOR FRONT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
AMZ130.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ150-
152-154.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ156-
158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...JBM
SHORT TERM...CQD
LONG TERM...BTC
AVIATION...JBM/BTC/JME
MARINE...JBM/BTC/RF
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1240 AM EST SUN JAN 29 2012
.SYNOPSIS...
A DRY COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...THEN ANOTHER
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST MONDAY
THROUGH WEDNESDAY. A FRONTAL BOUNDARY WILL SLOWLY MOVE THROUGH THE
AREA THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1230 AM SUN...MINOR UPDATE FOR CLOUD COVER WITH SHRT WV MOVING
THROUGH AREA LATER TONIGHT INTO SUN MORNING. MODERATE CAA URGE
DEVELOPING OVER AREA IN WAKE OF DRY COLD FRONT MOVING OFFSHORE WHILE
MID CLOUDS WITH UPR LVL FEATURE ARE SLOWER TO MOVE E. LATEST GDNC
INDICATES THIS ACTVTY MOVING ACROSS LATER TONIGHT INTO SUN MORNING.
MINOR ADJUSTMENTS FOR CURRENT TEMP TRENDS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 3 PM SAT...STRONG HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE DEEP SOUTH AND SE STATES. COOLER CONDITIONS EXPECTED SUN WITH
N FLOW EARLY BEHIND THE FRONT...BECOMING W/SW IN THE AFTERNOON.
LOW LEVEL THICKNESS VALUES AND MOSTLY SUNNY SKIES SUPPORT HIGH
TEMPS IN THE 50S...MUCH CLOSER TO CLIMO NORMS FOR LATE JAN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...THE NORTHERN STREAM JET WILL DOMINATE EARLY
IN THE PERIOD WITH THE PASSAGE OF A SHORT WAVE TROUGH AND
ASSOCIATED SECONDARY DRY SURFACE COLD FRONT AGAIN SUNDAY NIGHT.
NEAR NORMAL HIGHS IN THE UPPER LOWER TO MIDDLE 50S ARE FORECAST ON
MONDAY AS AS COLD ADVECTION OCCURS WITH HIGH PRESSURE CRESTING
OVER THE AREA. A MODERATION IN TEMPERATURES INTO THE LOWER 60S
WILL OCCUR TUESDAY AS THE SURFACE HIGH MOVES OFF THE COAST AND
SOUTHERLY RETURN FLOW DEVELOPS. SOUTHERLY FLOW AND MILD
TEMPERATURES WELL INTO THE 60S WILL CONTINUE WEDNESDAY AND
THURSDAY. WEDNESDAY NIGHT A BACK DOOR COLD FRONT WILL STALL JUST
NORTH OF THE REGION THEN LIFT BACK TO THE NORTH THURSDAY AS
DEVELOPING LOW PRESSURE MOVES FROM THE TENNESSEE VALLEY TO OFF THE
MID ATLANTIC COAST. THIS SYSTEM WILL CIRCULATE MOISTURE FROM OFF
OF THE GULF OF MEXICO ACROSS THE CAROLINAS AND BRING A CHANCE OF
SHOWERS TO OUR REGION ON THURSDAY.
A COMPLEX PATTERN APPEARS TO BE SETTING UP FOR LATE NEXT INTO NEXT
WEEKEND AS A MEAN EASTERN UPPER TROUGH EVOLVES. A COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY NIGHT...CROSSING THE REGION ON
FRIDAY BUT STALLING JUST SOUTH OF EASTERN NC. MILD TEMPERATURES ARE
EXPECTED TO CONTINUE FRIDAY AHEAD OF THE FRONT ALONG WITH A DECENT
CHANCE FOR SHOWERS. A SERIES OF WEAK LOW PRESSURE AREAS ARE FORECAST
TO MOVE ALONG THE STALLED FRONTAL BOUNDARY PRODUCING A COOLER AND
WET PATTERN ACROSS THE AREA OVER THE WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /06Z SUNDAY THROUGH 06Z MONDAY/
AS OF 1230 AM SUN...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
WINDS HAVE SHIFTED TO NW IN WAKE OF DRY FRONTAL PASSAGE AND MAY SEE
BRIEF PERIOD OF GUSTS TO 15-20KT NEXT FEW HOUR. SCT MID CLOUDS
MOVING ACROSS 09Z-12Z...OTRW CLEAR.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...OUTSIDE OF THE USUAL LATE NIGHT AND EARLY
MORNING GROUND FOG THAT COULD CAUSE TEMPORARY REDUCTIONS IN
VISIBILITIES...PREVAILING VFR CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY. A DRY COLD FRONT WILL CROSS THE AREA SUNDAY NIGHT. DRY
HIGH PRESSURE WILL THEN INFLUENCE THE WEATHER MONDAY THROUGH
WEDNESDAY. SOUTHERLY FLOW OFF OF THE GULF OF MEXICO AHEAD OF AN
APPROACHING COLD FRONT THURSDAY WILL BRING A CHANCE OF A FEW
SHOWERS WITH THE POSSIBILITY OF SUB VFR CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1230 AM SUN...NO CHANGES WITH UPDATE. CAA SURGE DEVELOPING AS
EXPECTED IN WAKE OF DRY FRONTAL PASSAGE.
/PREVIOUS DISCUSSION/
AS OF 10 PM SAT...FORECAST LOOKS TO BE ON TRACK. CURRENT OBS
ILLUSTRATE A WSWLY FLOW AROUND 5-10KTS WITH SEAS HOVERING AROUND 3FT
ACROSS THE COASTAL WATERS. WINDS HAVE BEEN GUSTING AOA 20KT TO THE W
BEHIND FRONT AND MDLS SHOW GUSTY WINDS DEVELOPING ALONG THE COAST
AFTER FROPA. BASED ON LATEST RUC13 AND LOCAL WRF MDL HAVE ADDED SCA
FOR ALBEMARLE SOUND AS BOTH SHOW BRIEF PD OF 20 TO 25 KTS LATER
TONIGHT. WINDS WILL BE FAIRLY QUICK TO DIMINISH MID SUNDAY MORNING
AS FRONT MOVES FURTHER OFFSHORE. N WINDS WILL BACK THROUGH THE DAY
AND BECOME W/NW IN THE AFTERNOON.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...MARGINAL SMALL CRAFT ADVISORY CONDITIONS
ARE EXPECTED AGAIN LATE SUNDAY NIGHT/EARLY MONDAY AS A SECONDARY
SURGE OF COOLER AIR PUSHES ACROSS THE WATERS. FREQUENT GUSTS TO 25
KT AND 5 TO 6 FT SEAS OVER THE OUTER WATERS WILL BE FORECAST.
CONDITIONS WILL IMPROVE AGAIN MONDAY AFTERNOON AND NIGHT AS A
STRONGER AND MORE PERSISTENT HIGH PRESSURE SYSTEM BUILDS OVER THE
WATERS. NW WINDS WILL DECREASE TO LESS THAN 15 KT MONDAY
AFTERNOON...AND 10 KT OR LESS MONDAY EVENING BEFORE BECOMING SW
10-15 KT LATE. SEAS WILL SUBSIDE TO 2 TO 3 FT MONDAY
AFTERNOON...AND 1-2 FT FOR MOST OF MONDAY NIGHT. SW WINDS 10-15 KT
WILL OCCUR TUESDAY AND TUESDAY NIGHT AS THE HIGH MOVES OFF THE
COAST WITH SEAS 2-3 FT TUESDAY BUILDING TO 3-4 FT TUESDAY NIGHT.
SW WINDS WILL INCREASE TO 15 TO 20 KT WEDNESDAY AHEAD OF A BACK
DOOR COLD FRONT WHOSE SOUTHERN EXTENT IS STILL UNDETERMINED.
CONSENSUS OF THE MODELS KEEP IT JUST NORTH OF THE NC WATERS.
MAGNITUDE AND DIRECTION OF WINDS FOR WEDNESDAY NIGHT INTO THURSDAY
STILL A LITTLE UNCERTAIN AS SOUTHWARD EXTENT OF BACK DOOR FRONT
UNKNOWN AND THERE WILL BE AN APPROACH OF A COLD FRONT FROM THE
WEST LATE. FOR NOW WILL FORECAST SW WINDS AROUND 15 KT AND SEAS
AROUND 3 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...JBM
SHORT TERM...CQD
LONG TERM...JME
AVIATION...JBM/JME
MARINE...JBM/RF/JME
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1240 PM EST SUN JAN 29 2012
.SYNOPSIS...
A CLIPPER WILL WORK ITS WAY ACROSS THE SOUTHERN GREAT LAKES TODAY
AND BRING ANOTHER SHOT OF LIGHT SNOW TO THE AREA. A RIDGE MOVES
ACROSS TONIGHT. A WARM FRONT WILL LIFT NORTH MONDAY AND MONDAY
EVENING AND WILL BRING TEMPERATURES FOR MID WEEK BACK WELL ABOVE
NORMAL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE LOW MOVING INTO SOUTH CENTRAL MICHIGAN WITH TROF/COLD
FRONT EXTENDING SSW FROM THE LOW. ALOFT MODELS SHOW A FAIRLY
VIGOROUS SHORT WAVE ASSOCIATED WITH THE SYSTEM WHICH WILL TRANSIT
NORTHERN OHIO THIS AFTERNOON. RADAR AND OBS SHOW ASSOCIATED SNOW
MOVING INTO FAR NWRN OHIO THIS HOUR WITH DEFIANCE NOW REPORTING
3/4SM VISIBILITY IN SNOW. EXPECT SNOW TO BEGIN IN TOL THIS HOUR
WITH SNOW REACHING KCLE VICINITY AROUND 3PM BASED ON RADAR TIMING.
HAVE ADJUSTED POPS AND WX IN GRIDS TO REFLECT THIS. ALTHOUGH POPS
ARE HIGH THIS WILL NOT BE AN ALL DAY EVENT AND IN FACE EXPECT ONLY
A LIGHT ACCUM...WITH MOST PLACES AROUND AN INCH. SOME OF THE
HIGHER ELEVATIONS FROM MFD NE ACROSS THE SNOW BELT COULD SEE
BETWEEN 1 AND 2 OF SNOWFALL HOWEVER TEMPS CURRENTLY IN THE MID
30S SO ACTUAL ACCUMS WILL STRUGGLE...AT LEAST DURING THE DAY.
ALSO...SNOW BEING BEING ENHANCED OFF LAKE MICHIGAN AND THIS WILL
LIKELY OCCUR THIS EVENING AND TONIGHT OFF LAKE ERIE INTO NERN OHIO
AND NWRN PA...BUT WILL NOT MAKE CHANGES THIS UPDATE. OTHER ISSUE
IS THE WIND. THE RUC SHOWS THE CORE OF THE HIGH WINDS AT 850MB
WILL MOVE ACROSS SOUTHERN OHIO...ALTHOUGH AT 925MB MODEL SHOWS THE
HIGHEST CORE (40KTS) MOVES ACROSS NRN OHIO. AT THIS TIME WILL
CONTINUE WITH THE WIND ADVISORY GIVEN THE EXPECTATION THAT THE
AIRMASS IS MORE UNSTABLE AND WILL ALLOW FOR DEEPER MIXING THAN
YDAY BUT THINKING THIS WILL BE A MARGINAL EVENT AND LIKELY
CONFINED TO THE VICINITY OF THE FRONT.
PREVIOUS...A CLIPPER TO COME ACROSS THE SOUTHERN GREAT LAKES AND
OHIO VALLEY TODAY WILL BRING ANOTHER QUICK AND LIGHT SNOW TO THE
ENTIRE FORECAST AREA. AS SHORTWAVE CROSSES AND TROUGH
SHARPENS...WINDS WILL PICK UP AND GUST. HAVE ISSUED A WIND
ADVISORY FOR THE SOUTHERN HALF OF THE AREA. THIS IS WHERE GUSTS TO
50 MPH LOOK MORE LIKELY. MIXING POTENTIAL IS GOOD TODAY. AS FAR AS
SNOW TIMING GOES...LOOKING AT 11 AM TO 5 PM FOR THE BULK OF IT.
ACROSS NE OHIO/NW PA...BETTER SNOW WILL START THIS AFTERNOON AND
LINGER INTO THE EVENING WITH SOME BETTER CONVERGENCE ALONG THE
LAKESHORE/SNOWBELT. MOST PLACES WILL BE AROUND AN INCH...BUT THE
SNOWBELT MAY GET UPWARDS OF 3 INCHES. WENT ON THE WARMER SIDE OF
TEMPS...THINKING WE COULD GAIN SEVERAL DEGREES BEFORE THE SNOW
BEGINS. WILL MENTION POSSIBLE RAIN/SNOW MIX...BUT SNOW LOOKS LIKE
THE BETTER OPTION WITH TEMPS LIKELY DROPPING A FEW DEGREES WITH
THE ARRIVAL OF THE PRECIPITATION. NO EARLY MORNING CHANGES MADE TO
THE FORECAST FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SNOW MAY BE LINGERING ACROSS THE EAST HALF DURING THE EVENING
HOURS...THEN TRANSITION TO SOME LIGHT LAKE EFFECT. AFTER ABOUT
03Z TEMPS GET COLD ENOUGH TO HAVE A DECENT LAKE INFLUENCE. WILL
HAVE LIKELY POPS FOR THE FAR EASTERN SNOWBELT THROUGH MOST OF THE
NIGHT. ONLY LIGHT AMOUNTS FORECAST THOUGH AS WE GET SOME
SIGNIFICANT DRYING IN AT THE SAME TIME AS THE COLDER AIR.
A WARM FRONT LIFTS ACROSS THE AREA MONDAY AND MONDAY EVENING.
TEMPERATURES ONCE AGAIN WARM AND WILL BE FORECAST TO TOP 40 IN
MANY PLACES MONDAY. THE ENTIRE AREA LOOKS TO BE WELL INTO THE 40S
FOR TUESDAY. MODELS HAVE BEEN FAIRLY CONSISTENT IN BRINGING SOME
WARM FRONTAL PRECIP INTO THE FAR NORTHEAST MONDAY. HAVE CONTINUED
THE CHANCE POPS AND DEPENDING ON TEMPS MAY BE LIGHT SNOW OR RAIN.
A FEW SPRINKLES OR FLURRIES MAY OCCUR ON THE FRINGES.
TUESDAY WILL LIKELY BE DRY AS WE ARE STILL A WAYS FROM ANY
FORCING. COLD FRONT TIMING APPEARS TO BE EARLY WEDNESDAY MORNING.
SCATTERED SHOWERS WILL ACCOMPANY THE FRONT OVERNIGHT TUESDAY. WE
GET HIGH PRESSURE AND DRYING TO BUILD IN QUICKLY ON WEDNESDAY. THE
FRONT DOES NOT HAVE A TIGHT GRADIENT IN TEMPERATURE AND NO REAL
COLD AIR PUSH AS THE FLOW FLATTENS OUT AGAIN. WILL KEEP TEMPS IN
THE 40S STILL.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MODELS ARE CONTINUING TO STRUGGLE IN THE EXTENDED. HAVE ENDED UP
GOING WITH A HPC AND ECMWF BLEND. THIS WOULD BRING A CHANCE OF RAIN
TO THE AREA ON THURSDAY AS LOW PRESSURE TRACKS ACROSS OHIO. WE THEN
AWAIT ANOTHER PIECE OF JET ENERGY TO DIVE INTO A TROUGH THAT WILL BE
LOCATED OVER THE EASTERN HALF OF THE US. A TROUGH IN THIS POSITION
WILL EVENTUALLY DUMP SOME COLD AIR INTO THE REGION. HOWEVER IT
APPEARS THIS WONT OCCUR UNTIL SATURDAY NIGHT INTO SUNDAY.
HIGHS WILL CONTINUE ON THE WARM SIDE ON THURSDAY WITH HIGHS INTO THE
40S. COOLER FOR FRIDAY AND SATURDAY WITH HIGHS CLOSER TO SEASONAL
AVERAGES.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
CLIPPER SYSTEM NOW INTO SE LOWER MICHIGAN WILL MOVE EAST OF THE
AREA THIS EVENING...THEN MOVE OFF THE MID ATLANTIC COAST
OVERNIGHT. THAT SAID EXPECT SNOW NOW INTO NW OHIO TO SPREAD EAST
ACROSS ENTIRE AREA THIS AFTERNOON/EVENING AND TO BE EAST OF THE
AREA BY LATE EVENING. MAY LINGER SOME EXTREME NE OH/NW PA. EXPECT
A WIDESPREAD INCH OR SO BEFORE SNOW ENDS.
EXPECT SW WINDS AHEAD OF FRONT GUSTING INTO MID 30S. WINDS TURN TO
THE WEST BEHIND THE FRONT. WINDS WILL BEGIN TO DIMINISH AFTER
SUNSET AND THEN TURN BACK TO THE SOUTH-SOUTHWEST OVERNIGHT.
ANOTHER CLIPPER WILL SWING ACROSS THE CENTRAL GREAT LAKES TODAY.
EXPECT TO SEE CEILINGS LOWER THROUGH THE MORNING WITH SNOW
ARRIVING IN NW OHIO NEAR 16Z...CENTRAL AREAS AROUND 17Z AND
EASTERN AREAS AROUND 19Z. AS THE SNOW ARRIVES EXPECT TO SEE
CEILINGS DROP TO MVFR LEVELS. THERE WILL BE A 2 TO 3 HOUR WINDOW OF
MODERATE SNOWFALL WITH IFR CONDITIONS LIKELY. THE SNOW MAY LINGER
A BIT LONGER ACROSS THE EASTERN THIRD OF THE REGION...POSSIBLY
INTO THE EVENING.
THE OTHER CONCERN FOR THE DAY WILL BE GUSTY WINDS...ESPECIALLY
ACROSS THE SOUTHERN TAF SITES. SOUTHWEST TO WEST WINDS MAY GUST
OVER 40 KNOTS SOUTH OF A KFDY TO KYNG LINE. NORTH OF THIS LINE 30
TO 35 KNOT GUSTS WILL BE POSSIBLE. THE WINDS WILL LIKELY BE THE
STRONGEST JUST AHEAD OF THE AREA OF SNOWFALL AND IN THE WAKE OF THE
FRONT THAT WILL MOVE ACROSS THE AREA THROUGH THE AFTERNOON. THE
GUSTY WINDS WILL SUBSIDE BY EARLY EVENING.
.OUTLOOK...NON-VFR CONDITIONS ARE POSSIBLE TUESDAY AFTERNOON
THROUGH WEDNESDAY AFTERNOON IN PERIODS OF RAIN.
&&
.MARINE...
ANOTHER CLIPPER TYPE STORM SYSTEM WILL SWEEP ACROSS THE CENTRAL
GREAT LAKES TODAY WITH A COLD FRONT CROSSING THE LAKE THIS
AFTERNOON. WINDS WILL REMAIN SOUTHWEST AHEAD OF THIS CLIPPER BUT
WILL SHIFT TO THE WEST AS THE FRONT PASSES. SOUTHWEST WINDS OF 15
TO 25 KNOTS WILL PICK UP TO AROUND 30 KNOTS AS THE FRONT PASSES.
SO WITH THE LIGHTER WINDS THIS MORNING WE WILL BE ABLE TO DROP THE
GALE WARNING AND THE LOW WATER ADVISORY. HOWEVER WIND SPEEDS AND
WAVES WILL REMAIN HIGH ENOUGH TO KEEP A SMALL CRAFT ADVISORY GOING
THROUGH THE DAY. ACTUALLY WIND SPEEDS WILL REMAIN HIGH ENOUGH TO
KEEP A SMALL CRAFT ADVISORY GOING INTO AT LEAST EARLY MONDAY
MORNING.
THE NEXT STORM SYSTEM WILL BRING INCREASING SOUTH TO SOUTHWEST WINDS
TO THE LAKE BY TUESDAY AFTERNOON AND WILL LIKELY GET STRONGER IN
THE WAKE OF A COLD FRONT ON WEDNESDAY. THIS STORM SYSTEM MAY END UP
REQUIRING A GALE WARNING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ017-020>023-
027>033-036>038-047.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...TK/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...MULLEN
AVIATION...DJB
MARINE...MULLEN
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
1221 PM EST SUN JAN 29 2012
.SYNOPSIS...
A CLIPPER WILL WORK ITS WAY ACROSS THE SOUTHERN GREAT LAKES TODAY
AND BRING ANOTHER SHOT OF LIGHT SNOW TO THE AREA. A RIDGE MOVES
ACROSS TONIGHT. A WARM FRONT WILL LIFT NORTH MONDAY AND MONDAY
EVENING AND WILL BRING TEMPERATURES FOR MID WEEK BACK WELL ABOVE
NORMAL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE LOW MOVING INTO SOUTH CENTRAL MICHIGAN WITH TROF/COLD
FRONT EXTENDING SSW FROM THE LOW. ALOFT MODELS SHOW A FAIRLY
VIGOROUS SHORT WAVE ASSOCIATED WITH THE SYSTEM WHICH WILL TRANSIT
NORTHERN OHIO THIS AFTERNOON. RADAR AND OBS SHOW ASSOCIATED SNOW
MOVING INTO FAR NWRN OHIO THIS HOUR WITH DEFIANCE NOW REPORTING
3/4SM VISIBILITY IN SNOW. EXPECT SNOW TO BEGIN IN TOL THIS HOUR
WITH SNOW REACHING KCLE VICINITY AROUND 3PM BASED ON RADAR TIMING.
HAVE ADJUSTED POPS AND WX IN GRIDS TO REFLECT THIS. ALTHOUGH POPS
ARE HIGH THIS WILL NOT BE AN ALL DAY EVENT AND IN FACE EXPECT ONLY
A LIGHT ACCUM...WITH MOST PLACES AROUND AN INCH. SOME OF THE
HIGHER ELEVATIONS FROM MFD NE ACROSS THE SNOW BELT COULD SEE
BETWEEN 1 AND 2 OF SNOWFALL HOWEVER TEMPS CURRENTLY IN THE MID
30S SO ACTUAL ACCUMS WILL STRUGGLE...AT LEAST DURING THE DAY.
ALSO...SNOW BEING BEING ENHANCED OFF LAKE MICHIGAN AND THIS WILL
LIKELY OCCUR THIS EVENING AND TONIGHT OFF LAKE ERIE INTO NERN OHIO
AND NWRN PA...BUT WILL NOT MAKE CHANGES THIS UPDATE. OTHER ISSUE
IS THE WIND. THE RUC SHOWS THE CORE OF THE HIGH WINDS AT 850MB
WILL MOVE ACROSS SOUTHERN OHIO...ALTHOUGH AT 925MB MODEL SHOWS THE
HIGHEST CORE (40KTS) MOVES ACROSS NRN OHIO. AT THIS TIME WILL
CONTINUE WITH THE WIND ADVISORY GIVEN THE EXPECTATION THAT THE
AIRMASS IS MORE UNSTABLE AND WILL ALLOW FOR DEEPER MIXING THAN
YDAY BUT THINKING THIS WILL BE A MARGINAL EVENT AND LIKELY
CONFINED TO THE VICINITY OF THE FRONT.
PREVIOUS...A CLIPPER TO COME ACROSS THE SOUTHERN GREAT LAKES AND
OHIO VALLEY TODAY WILL BRING ANOTHER QUICK AND LIGHT SNOW TO THE
ENTIRE FORECAST AREA. AS SHORTWAVE CROSSES AND TROUGH
SHARPENS...WINDS WILL PICK UP AND GUST. HAVE ISSUED A WIND
ADVISORY FOR THE SOUTHERN HALF OF THE AREA. THIS IS WHERE GUSTS TO
50 MPH LOOK MORE LIKELY. MIXING POTENTIAL IS GOOD TODAY. AS FAR AS
SNOW TIMING GOES...LOOKING AT 11 AM TO 5 PM FOR THE BULK OF IT.
ACROSS NE OHIO/NW PA...BETTER SNOW WILL START THIS AFTERNOON AND
LINGER INTO THE EVENING WITH SOME BETTER CONVERGENCE ALONG THE
LAKESHORE/SNOWBELT. MOST PLACES WILL BE AROUND AN INCH...BUT THE
SNOWBELT MAY GET UPWARDS OF 3 INCHES. WENT ON THE WARMER SIDE OF
TEMPS...THINKING WE COULD GAIN SEVERAL DEGREES BEFORE THE SNOW
BEGINS. WILL MENTION POSSIBLE RAIN/SNOW MIX...BUT SNOW LOOKS LIKE
THE BETTER OPTION WITH TEMPS LIKELY DROPPING A FEW DEGREES WITH
THE ARRIVAL OF THE PRECIPITATION. NO EARLY MORNING CHANGES MADE TO
THE FORECAST FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SNOW MAY BE LINGERING ACROSS THE EAST HALF DURING THE EVENING
HOURS...THEN TRANSITION TO SOME LIGHT LAKE EFFECT. AFTER ABOUT
03Z TEMPS GET COLD ENOUGH TO HAVE A DECENT LAKE INFLUENCE. WILL
HAVE LIKELY POPS FOR THE FAR EASTERN SNOWBELT THROUGH MOST OF THE
NIGHT. ONLY LIGHT AMOUNTS FORECAST THOUGH AS WE GET SOME
SIGNIFICANT DRYING IN AT THE SAME TIME AS THE COLDER AIR.
A WARM FRONT LIFTS ACROSS THE AREA MONDAY AND MONDAY EVENING.
TEMPERATURES ONCE AGAIN WARM AND WILL BE FORECAST TO TOP 40 IN
MANY PLACES MONDAY. THE ENTIRE AREA LOOKS TO BE WELL INTO THE 40S
FOR TUESDAY. MODELS HAVE BEEN FAIRLY CONSISTENT IN BRINGING SOME
WARM FRONTAL PRECIP INTO THE FAR NORTHEAST MONDAY. HAVE CONTINUED
THE CHANCE POPS AND DEPENDING ON TEMPS MAY BE LIGHT SNOW OR RAIN.
A FEW SPRINKLES OR FLURRIES MAY OCCUR ON THE FRINGES.
TUESDAY WILL LIKELY BE DRY AS WE ARE STILL A WAYS FROM ANY
FORCING. COLD FRONT TIMING APPEARS TO BE EARLY WEDNESDAY MORNING.
SCATTERED SHOWERS WILL ACCOMPANY THE FRONT OVERNIGHT TUESDAY. WE
GET HIGH PRESSURE AND DRYING TO BUILD IN QUICKLY ON WEDNESDAY. THE
FRONT DOES NOT HAVE A TIGHT GRADIENT IN TEMPERATURE AND NO REAL
COLD AIR PUSH AS THE FLOW FLATTENS OUT AGAIN. WILL KEEP TEMPS IN
THE 40S STILL.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
MODELS ARE CONTINUING TO STRUGGLE IN THE EXTENDED. HAVE ENDED UP
GOING WITH A HPC AND ECMWF BLEND. THIS WOULD BRING A CHANCE OF RAIN
TO THE AREA ON THURSDAY AS LOW PRESSURE TRACKS ACROSS OHIO. WE THEN
AWAIT ANOTHER PIECE OF JET ENERGY TO DIVE INTO A TROUGH THAT WILL BE
LOCATED OVER THE EASTERN HALF OF THE US. A TROUGH IN THIS POSITION
WILL EVENTUALLY DUMP SOME COLD AIR INTO THE REGION. HOWEVER IT
APPEARS THIS WONT OCCUR UNTIL SATURDAY NIGHT INTO SUNDAY.
HIGHS WILL CONTINUE ON THE WARM SIDE ON THURSDAY WITH HIGHS INTO THE
40S. COOLER FOR FRIDAY AND SATURDAY WITH HIGHS CLOSER TO SEASONAL
AVERAGES.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
ANOTHER CLIPPER WILL SWING ACROSS THE CENTRAL GREAT LAKES TODAY.
EXPECT TO SEE CEILINGS LOWER THROUGH THE MORNING WITH SNOW
ARRIVING IN NW OHIO NEAR 16Z...CENTRAL AREAS AROUND 17Z AND
EASTERN AREAS AROUND 19Z. AS THE SNOW ARRIVES EXPECT TO SEE
CEILINGS DROP TO MVFR LEVELS. THERE WILL BE A 2 TO 3 HOUR WINDOW OF
MODERATE SNOWFALL WITH IFR CONDITIONS LIKELY. THE SNOW MAY LINGER
A BIT LONGER ACROSS THE EASTERN THIRD OF THE REGION...POSSIBLY
INTO THE EVENING.
THE OTHER CONCERN FOR THE DAY WILL BE GUSTY WINDS...ESPECIALLY
ACROSS THE SOUTHERN TAF SITES. SOUTHWEST TO WEST WINDS MAY GUST
OVER 40 KNOTS SOUTH OF A KFDY TO KYNG LINE. NORTH OF THIS LINE 30
TO 35 KNOT GUSTS WILL BE POSSIBLE. THE WINDS WILL LIKELY BE THE
STRONGEST JUST AHEAD OF THE AREA OF SNOWFALL AND IN THE WAKE OF THE
FRONT THAT WILL MOVE ACROSS THE AREA THROUGH THE AFTERNOON. THE
GUSTY WINDS WILL SUBSIDE BY EARLY EVENING.
.OUTLOOK...NON-VFR CONDITIONS ARE POSSIBLE TUESDAY AFTERNOON
THROUGH WEDNESDAY AFTERNOON IN PERIODS OF RAIN.
&&
.MARINE...
ANOTHER CLIPPER TYPE STORM SYSTEM WILL SWEEP ACROSS THE CENTRAL
GREAT LAKES TODAY WITH A COLD FRONT CROSSING THE LAKE THIS
AFTERNOON. WINDS WILL REMAIN SOUTHWEST AHEAD OF THIS CLIPPER BUT
WILL SHIFT TO THE WEST AS THE FRONT PASSES. SOUTHWEST WINDS OF 15
TO 25 KNOTS WILL PICK UP TO AROUND 30 KNOTS AS THE FRONT PASSES.
SO WITH THE LIGHTER WINDS THIS MORNING WE WILL BE ABLE TO DROP THE
GALE WARNING AND THE LOW WATER ADVISORY. HOWEVER WIND SPEEDS AND
WAVES WILL REMAIN HIGH ENOUGH TO KEEP A SMALL CRAFT ADVISORY GOING
THROUGH THE DAY. ACTUALLY WIND SPEEDS WILL REMAIN HIGH ENOUGH TO
KEEP A SMALL CRAFT ADVISORY GOING INTO AT LEAST EARLY MONDAY
MORNING.
THE NEXT STORM SYSTEM WILL BRING INCREASING SOUTH TO SOUTHWEST WINDS
TO THE LAKE BY TUESDAY AFTERNOON AND WILL LIKELY GET STRONGER IN
THE WAKE OF A COLD FRONT ON WEDNESDAY. THIS STORM SYSTEM MAY END UP
REQUIRING A GALE WARNING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ017-020>023-
027>033-036>038-047.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...TK/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1004 PM EST MON JAN 30 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE ACROSS THE STATE TONIGHT...USHERING IN VERY
MILD TEMPERATURES FOR MUCH OF THE WEEK. THE WEATHER WILL REMAIN
MAINLY DRY...EXCEPT FOR A CHANCE OF LIGHT SNOW SHOWERS TONIGHT IN
THE NORTHERN MOUNTAINS...AND SCATTERED RAIN SHOWERS WEDNESDAY AND
THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
RADAR RETURNS ACROSS NORTHERN PA CONTINUE TO YIELD LITTLE IF ANY
GROUND TRUTH. BEST UPWARD VERTICAL MOTION FROM WAA WILL REMAIN
OVER THE FINGERLAKES NORTHWARD...AND HAVE HALVED PREVIOUS LIGHT
SNOW AMOUNTS FOR AREAS ALONG SR 6 AND POINTS NORTH.
WITH THE WARM ADVECTION AND CLOUDINESS OVERNIGHT...LOWS WILL ONLY
DIP INTO THE MID AND UPPER 20S...AND WILL LIKELY BEGIN TO SLOWLY
RISE AFTER 06Z ACROSS THE WEST BEHIND FROPA.
WARM FRONT BY TUE WILL BE ACROSS NY STATE...AND BROAD WSW FLOW
WILL KEEP PENNSYLVANIA DRY THRU TUESDAY. VERY MILD TEMPS WILL BE
SEEN AS 500MB HEIGHTS REACH 560 AND 850MB TEMPS RISE TO 5C+. THIS
SHOULD TRANSLATE INTO HIGHS TUESDAY APPROACHING 60F OVER SOME
SOUTHERN LOCATIONS...WITH UPPER 40S TO MID 50S FURTHER NORTH. THIS
WILL BE AS MUCH AS 15 TO 20 DEG ABOVE SEASONAL NORMS. WESTERLY
WINDS WILL BE BREEZY...ESP IN THE WESTERN HIGHER TERRAIN...BUT
NOTHING APPROACHING WHAT WE/VE SEEN OVER THE PAST COUPLE OF DAYS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A NRN STREAM SHORTWAVE TROUGH WILL PROGRESS EWD FROM THE NRN PLAINS
TO THE NORTHEAST TUE-WED. THE LOW-AMPLITUDE FAST-MOVG MID/UPPER
SYSTEM WILL BE ACCOMPANIED BY A WEAK SFC LOW TRACKING EWD ALONG THE
U.S./CANADIAN BORDER FROM MINNESOTA TO MAINE BY 0000 UTC 2 FEB 2012.
A BREEZY AND UNSEASONABLY MILD SWLY FLOW IN THE WARM SECTOR
PRECEDING THE TRAILING COLD FRONT WILL HELP BOOST TEMPERATURES
WELL-ABOVE CLIMATOLOGY /15-25 DEGREES/ PRIOR TO FROPA WHICH SHOULD
SLIDE NW-SE ACROSS THE COMMONWEALTH BY WED EVE. DESPITE FAIRLY
STRONG NEWD MOISTURE TRANSPORT INTO THE AREA VIA 40-50KT SWLY LLJ
THROUGH THE OH VALLEY...PCPN COVERAGE AND AMTS LOOK TO BE ON THE
LIGHTER SIDE GIVEN PROGRESSIVE NATURE OF THE SYSTEM...NWD
DISPLACEMENT OF BEST FORCING AND WEAK LOW-LEVEL CONVERGENCE. THE
SURFACE BOUNDARY WILL STALL-OUT NEAR OR SOUTH OF THE MASON DIXON
LINE AS THE FOCUS SHIFTS TO SPLIT FLOW TROUGH CROSSING THE PLAINS/MS
VLY AND ENTERING THE TN VLY/MID-ATLC REGION ON THURS. THIS FEATURE
SHOULD INDUCE A WEAK SFC WAVE TO TRACK EWD ALONG THE QUASI-STNRY
BAROCLINIC FRONTAL ZONE TO THE SOUTH OF PA.
CONCERNING THE FRONTAL WAVE FORECAST TO TRACK SOUTH OF PA WED
NGT-THURS...THE 12Z NAM IS THE MOST PROGRESSIVE SOLUTION THROUGHOUT
AND APPEARS TO BE AN OUTLIER COMPARED TO THE REST OF THE GUIDANCE.
THERE IS SLIGHT SPREAD WITH THE 12Z GFS/UKMET/ECMWF AND 00Z ECMWF ON
THE PROGRESSION BUT NOT AMPLIFICATION OF THE TROUGH AXIS HEADING
DOWNSTREAM. THE 12Z ECMWF DOES TREND A BIT WEAKER ALOFT WITH THIS
FEATURE THROUGH THE ERN PORTION OF THE COUNTRY BUT OVERALL NO LARGE
SCALE DIFFERENCES. HPC MODEL DIAGS PREFERRED A BLEND/COMPROMISE OF
THE OPERATIONAL GFS/UKMET AND ECMWF. THESE MODELS QPF FIELDS ARE IN
REASONABLY GOOD AGREEMENT SHOWING A RELATIVELY TIGHT GRADIENT OF
POSSIBLY ENHANCED PCPN ALONG/NORTH OF THE LOW TRACK FROM ERN KY ACRS
THE VIRGINIAS TO THE DELMARVA...AS UPPER LEVEL JET STREAK BECOMES
WELL-DEFINED. THIS SYSTEM SHOULD EXIT OFFSHORE THURS NGT AS HIGH
PRES OVERSPREADS THE REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODEL AND ENSEMBLE GUID STARTS THE PERIOD IN MUCH
BETTER AGREEMENT COMPARED TO YESTERDAY...SHOWING A HIGHLY AMPLIFIED
WEST COAST RIDGE/ROCKIES-PLAINS TROUGH CONFIGURATION WITH CONFLUENT
ZONAL FLOW DOWNSTREAM IN THE EAST. INDIVIDUAL SOLUTION SPREAD GROWS
QUICKLY IN TIME AND THE GUIDANCE BECOMES RATHER CHAOTIC WITH
VIRTUALLY NO RUN-TO-RUN CONSISTENCY. THE GFS/GEFS ARE QUICKER TO
EJECT THE PLAINS ENERGY EWD INTO THE OH VLY BY THE END OF THE PD
WHILE THE ECMWF LEAVES BEHIND SIGNIFICANT ENERGY IN THE SWRN CONUS.
GIVEN THE HIGH UNCERTAINTY IN THE EVOLUTION OF THE LARGE SCALE FLOW
FORECASTER CONFIDENCE REMAINS LOW. THEREFORE...THE LONG TERM GRIDS
WERE DERIVED USING A NEAR EQUAL BLEND OF HPC/GMOS AND GFS/ECMWF
GUIDANCE WHICH FAVORS NEAR TO ABOVE AVG TEMPERATURES AND A GRADUAL
INCREASE IN POPS FROM LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
A WARM FRONT OVR THE OHIO VALLEY WILL LIFT NORTHEAST THRU CENTRAL
PA LATE TONIGHT. JUST ENOUGH LIFT AHEAD OF THIS BOUNDARY TO
PERHAPS PRODUCE A BIT OF VERY LIGHT SNOW AT BFD THIS EVENING.
OTHERWISE...MDL DATA AND UPSTREAM OBS BOTH STRONGLY INDICATING VFR
CONDS OVERNIGHT WITH CLOUD BASES ARND 10KFT. BIGGEST AVIATION
CONCERN TONIGHT WILL BE DEVELOPING LLWS...THE RESULT OF STRONG
WSWRLY LOW LVL JET OVERSPREADING THE AREA...IN CONJUNCTION WITH
MUCH LIGHTER SOUTHERLY WINDS AT GROUND LEVEL. LATEST RUC 0-0.5KM
BULK SHEAR SUGGESTS ONSET OF LLWS CRITERIA WILL RANGE FROM
00Z-04Z FROM WEST TO EAST. SFC WARM FRONT MAY WORK INTO JST BY
ARND MIDNIGHT...RESULTING IN GUSTY SW WINDS AND DIMINISHED LLWS
THERE LATE TONIGHT.
FOR THE BULK OF CENTRAL PA...WARM FRONT WILL LIFT NORTH OF THE
AREA BY LATE AM...RESULTING IN A DECREASING THREAT OF LLWS BUT
INCREASING SW WINDS AT THE SFC /MDL SOUNDINGS SUPPORT GUSTS TO NR
25KTS/. ALL MDL DATA POINTING TOWARD A HIGH DEGREE OF CONFIDENCE IN
VFR CONDS TUESDAY WITH THE POSSIBLE EXCEPTION OF LATE DAY MVFR
CIGS AT BFD.
OUTLOOK...
WED...AM LOW CIGS/SHRA POSS W MTNS.
THU...AM FOG POSSIBLE...ESP W MTNS.
FRI-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...DEVOIR/RXR
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
800 PM EST MON JAN 30 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE ACROSS THE STATE TONIGHT...USHERING IN VERY
MILD TEMPERATURES FOR MUCH OF THE WEEK. THE WEATHER WILL REMAIN
MAINLY DRY...EXCEPT FOR A CHANCE OF LIGHT SNOW SHOWERS TONIGHT IN
THE NORTHERN MOUNTAINS...AND SCATTERED RAIN SHOWERS WEDNESDAY AND
THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
RADAR RETURNS ACROSS NORTHERN PA YIELDING LITTLE IF ANY GROUND
TRUTH. WELLSBORO HAD A BRIEF LIGHT SNOW SHOWER. WAA CONTS TO BRUSH
THE NORTHERN TIER THIS EVENING...WITH A TRACE TO LESS THAN AN INCH
OF ACCUMULATION GENERALLY NORTH OF SR 6. SW-W 850MB JET OF 50KTS
NOSES IN FROM THE WEST WITH THE WARM FRONT LEADING THE PUSH OF
MILDER AIR BACK INTO CENTRAL PA. AS A RESULT...LOWS TONIGHT WILL ONLY
DIP INTO THE MID AND UPPER 20S...AND WILL LIKELY BEGIN TO SLOWLY
RISE AFTER 06Z ACROSS THE WEST BEHIND FROPA.
WARM FRONT BY TUE WILL BE ACROSS NY STATE...AND BROAD WSW FLOW
WILL KEEP PENNSYLVANIA DRY THRU TUESDAY. VERY MILD TEMPS WILL BE
SEEN AS 500MB HEIGHTS REACH 560 AND 850MB TEMPS RISE TO 5C+. THIS
SHOULD TRANSLATE INTO HIGHS TUESDAY APPROACHING 60F OVER SOME
SOUTHERN LOCATIONS...WITH UPPER 40S TO MID 50S FURTHER NORTH. THIS
WILL BE AS MUCH AS 15 TO 20 DEG ABOVE SEASONAL NORMS. WESTERLY
WINDS WILL BE BREEZY...ESP IN THE WESTERN HIGHER TERRAIN...BUT
NOTHING APPROACHING WHAT WE/VE SEEN OVER THE PAST COUPLE OF DAYS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A NRN STREAM SHORTWAVE TROUGH WILL PROGRESS EWD FROM THE NRN PLAINS
TO THE NORTHEAST TUE-WED. THE LOW-AMPLITUDE FAST-MOVG MID/UPPER
SYSTEM WILL BE ACCOMPANIED BY A WEAK SFC LOW TRACKING EWD ALONG THE
U.S./CANADIAN BORDER FROM MINNESOTA TO MAINE BY 0000 UTC 2 FEB 2012.
A BREEZY AND UNSEASONABLY MILD SWLY FLOW IN THE WARM SECTOR
PRECEDING THE TRAILING COLD FRONT WILL HELP BOOST TEMPERATURES
WELL-ABOVE CLIMATOLOGY /15-25 DEGREES/ PRIOR TO FROPA WHICH SHOULD
SLIDE NW-SE ACROSS THE COMMONWEALTH BY WED EVE. DESPITE FAIRLY
STRONG NEWD MOISTURE TRANSPORT INTO THE AREA VIA 40-50KT SWLY LLJ
THROUGH THE OH VALLEY...PCPN COVERAGE AND AMTS LOOK TO BE ON THE
LIGHTER SIDE GIVEN PROGRESSIVE NATURE OF THE SYSTEM...NWD
DISPLACEMENT OF BEST FORCING AND WEAK LOW-LEVEL CONVERGENCE. THE
SURFACE BOUNDARY WILL STALL-OUT NEAR OR SOUTH OF THE MASON DIXON
LINE AS THE FOCUS SHIFTS TO SPLIT FLOW TROUGH CROSSING THE PLAINS/MS
VLY AND ENTERING THE TN VLY/MID-ATLC REGION ON THURS. THIS FEATURE
SHOULD INDUCE A WEAK SFC WAVE TO TRACK EWD ALONG THE QUASI-STNRY
BAROCLINIC FRONTAL ZONE TO THE SOUTH OF PA.
CONCERNING THE FRONTAL WAVE FORECAST TO TRACK SOUTH OF PA WED
NGT-THURS...THE 12Z NAM IS THE MOST PROGRESSIVE SOLUTION THROUGHOUT
AND APPEARS TO BE AN OUTLIER COMPARED TO THE REST OF THE GUIDANCE.
THERE IS SLIGHT SPREAD WITH THE 12Z GFS/UKMET/ECMWF AND 00Z ECMWF ON
THE PROGRESSION BUT NOT AMPLIFICATION OF THE TROUGH AXIS HEADING
DOWNSTREAM. THE 12Z ECMWF DOES TREND A BIT WEAKER ALOFT WITH THIS
FEATURE THROUGH THE ERN PORTION OF THE COUNTRY BUT OVERALL NO LARGE
SCALE DIFFERENCES. HPC MODEL DIAGS PREFERRED A BLEND/COMPROMISE OF
THE OPERATIONAL GFS/UKMET AND ECMWF. THESE MODELS QPF FIELDS ARE IN
REASONABLY GOOD AGREEMENT SHOWING A RELATIVELY TIGHT GRADIENT OF
POSSIBLY ENHANCED PCPN ALONG/NORTH OF THE LOW TRACK FROM ERN KY ACRS
THE VIRGINIAS TO THE DELMARVA...AS UPPER LEVEL JET STREAK BECOMES
WELL-DEFINED. THIS SYSTEM SHOULD EXIT OFFSHORE THURS NGT AS HIGH
PRES OVERSPREADS THE REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODEL AND ENSEMBLE GUID STARTS THE PERIOD IN MUCH
BETTER AGREEMENT COMPARED TO YESTERDAY...SHOWING A HIGHLY AMPLIFIED
WEST COAST RIDGE/ROCKIES-PLAINS TROUGH CONFIGURATION WITH CONFLUENT
ZONAL FLOW DOWNSTREAM IN THE EAST. INDIVIDUAL SOLUTION SPREAD GROWS
QUICKLY IN TIME AND THE GUIDANCE BECOMES RATHER CHAOTIC WITH
VIRTUALLY NO RUN-TO-RUN CONSISTENCY. THE GFS/GEFS ARE QUICKER TO
EJECT THE PLAINS ENERGY EWD INTO THE OH VLY BY THE END OF THE PD
WHILE THE ECMWF LEAVES BEHIND SIGNIFICANT ENERGY IN THE SWRN CONUS.
GIVEN THE HIGH UNCERTAINTY IN THE EVOLUTION OF THE LARGE SCALE FLOW
FORECASTER CONFIDENCE REMAINS LOW. THEREFORE...THE LONG TERM GRIDS
WERE DERIVED USING A NEAR EQUAL BLEND OF HPC/GMOS AND GFS/ECMWF
GUIDANCE WHICH FAVORS NEAR TO ABOVE AVG TEMPERATURES AND A GRADUAL
INCREASE IN POPS FROM LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
A WARM FRONT OVR THE OHIO VALLEY WILL LIFT NORTHEAST THRU CENTRAL
PA LATE TONIGHT. JUST ENOUGH LIFT AHEAD OF THIS BOUNDARY TO
PERHAPS PRODUCE A BIT OF VERY LIGHT SNOW AT BFD THIS EVENING.
OTHERWISE...MDL DATA AND UPSTREAM OBS BOTH STRONGLY INDICATING VFR
CONDS OVERNIGHT WITH CLOUD BASES ARND 10KFT. BIGGEST AVIATION
CONCERN TONIGHT WILL BE DEVELOPING LLWS...THE RESULT OF STRONG
WSWRLY LOW LVL JET OVERSPREADING THE AREA...IN CONJUNCTION WITH
MUCH LIGHTER SOUTHERLY WINDS AT GROUND LEVEL. LATEST RUC 0-0.5KM
BULK SHEAR SUGGESTS ONSET OF LLWS CRITERIA WILL RANGE FROM
00Z-04Z FROM WEST TO EAST. SFC WARM FRONT MAY WORK INTO JST BY
ARND MIDNIGHT...RESULTING IN GUSTY SW WINDS AND DIMINISHED LLWS
THERE LATE TONIGHT.
FOR THE BULK OF CENTRAL PA...WARM FRONT WILL LIFT NORTH OF THE
AREA BY LATE AM...RESULTING IN A DECREASING THREAT OF LLWS BUT
INCREASING SW WINDS AT THE SFC /MDL SOUNDINGS SUPPORT GUSTS TO NR
25KTS/. ALL MDL DATA POINTING TOWARD A HIGH DEGREE OF CONFIDENCE IN
VFR CONDS TUESDAY WITH THE POSSIBLE EXCEPTION OF LATE DAY MVFR
CIGS AT BFD.
OUTLOOK...
WED...AM LOW CIGS/SHRA POSS W MTNS.
THU...AM FOG POSSIBLE...ESP W MTNS.
FRI-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...DEVOIR/RXR
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
652 PM EST MON JAN 30 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE ACROSS THE STATE TONIGHT...USHERING IN VERY
MILD TEMPERATURES FOR MUCH OF THE WEEK. THE WEATHER WILL REMAIN
MAINLY DRY...EXCEPT FOR A CHANCE OF LIGHT SNOW SHOWERS TONIGHT IN
THE NORTHERN MOUNTAINS...AND SCATTERED RAIN SHOWERS WEDNESDAY AND
THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
HIGH PRESSURE OVER PENNSYLVANIA CEDES TO APPROACHING WARM FRONT
OVERNIGHT. WAA OVER GLAKES GENERATING JUST ENOUGH LIFT FOR A
NARROW AREA OF LIGHT SNOW. THIS WILL SLIDE EASTWARD THIS
EVENING...BRUSHING NORTHERN PA WITH JUST LIGHT ACCUMS AT MOST.
SW-W 850MB JET OF 50KTS NOSES IN FROM THE WEST WITH THE WARM FRONT
TONIGHT...LEADING THE PUSH OF MILDER AIR BACK INTO CENTRAL PA.
LOWS TONIGHT WILL ONLY DIP INTO THE MID AND UPPER 20S...AND WILL
LIKELY BEGIN TO SLOWLY RISE AFTER 06Z ACROSS THE WEST BEHIND
FROPA.
WARM FRONT BY TUE WILL BE ACROSS NY STATE...AND BROAD WSW FLOW
WILL KEEP PENNSYLVANIA DRY THRU TUESDAY. VERY MILD TEMPS WILL BE
SEEN AS 500MB HEIGHTS REACH 560 AND 850MB TEMPS RISE TO 5C+. THIS
SHOULD TRANSLATE INTO HIGHS TUESDAY APPROACHING 60F OVER SOME
SOUTHERN LOCATIONS...WITH UPPER 40S TO MID 50S FURTHER NORTH. THIS
WILL BE AS MUCH AS 15 TO 20 DEG ABOVE SEASONAL NORMS. WESTERLY
WINDS WILL BE BREEZY...ESP IN THE WESTERN HIGHER TERRAIN...BUT
NOTHING APPROACHING WHAT WE/VE SEEN OVER THE PAST COUPLE OF DAYS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A NRN STREAM SHORTWAVE TROUGH WILL PROGRESS EWD FROM THE NRN PLAINS
TO THE NORTHEAST TUE-WED. THE LOW-AMPLITUDE FAST-MOVG MID/UPPER
SYSTEM WILL BE ACCOMPANIED BY A WEAK SFC LOW TRACKING EWD ALONG THE
U.S./CANADIAN BORDER FROM MINNESOTA TO MAINE BY 0000 UTC 2 FEB 2012.
A BREEZY AND UNSEASONABLY MILD SWLY FLOW IN THE WARM SECTOR
PRECEDING THE TRAILING COLD FRONT WILL HELP BOOST TEMPERATURES
WELL-ABOVE CLIMATOLOGY /15-25 DEGREES/ PRIOR TO FROPA WHICH SHOULD
SLIDE NW-SE ACROSS THE COMMONWEALTH BY WED EVE. DESPITE FAIRLY
STRONG NEWD MOISTURE TRANSPORT INTO THE AREA VIA 40-50KT SWLY LLJ
THROUGH THE OH VALLEY...PCPN COVERAGE AND AMTS LOOK TO BE ON THE
LIGHTER SIDE GIVEN PROGRESSIVE NATURE OF THE SYSTEM...NWD
DISPLACEMENT OF BEST FORCING AND WEAK LOW-LEVEL CONVERGENCE. THE
SURFACE BOUNDARY WILL STALL-OUT NEAR OR SOUTH OF THE MASON DIXON
LINE AS THE FOCUS SHIFTS TO SPLIT FLOW TROUGH CROSSING THE PLAINS/MS
VLY AND ENTERING THE TN VLY/MID-ATLC REGION ON THURS. THIS FEATURE
SHOULD INDUCE A WEAK SFC WAVE TO TRACK EWD ALONG THE QUASI-STNRY
BAROCLINIC FRONTAL ZONE TO THE SOUTH OF PA.
CONCERNING THE FRONTAL WAVE FORECAST TO TRACK SOUTH OF PA WED
NGT-THURS...THE 12Z NAM IS THE MOST PROGRESSIVE SOLUTION THROUGHOUT
AND APPEARS TO BE AN OUTLIER COMPARED TO THE REST OF THE GUIDANCE.
THERE IS SLIGHT SPREAD WITH THE 12Z GFS/UKMET/ECMWF AND 00Z ECMWF ON
THE PROGRESSION BUT NOT AMPLIFICATION OF THE TROUGH AXIS HEADING
DOWNSTREAM. THE 12Z ECMWF DOES TREND A BIT WEAKER ALOFT WITH THIS
FEATURE THROUGH THE ERN PORTION OF THE COUNTRY BUT OVERALL NO LARGE
SCALE DIFFERENCES. HPC MODEL DIAGS PREFERRED A BLEND/COMPROMISE OF
THE OPERATIONAL GFS/UKMET AND ECMWF. THESE MODELS QPF FIELDS ARE IN
REASONABLY GOOD AGREEMENT SHOWING A RELATIVELY TIGHT GRADIENT OF
POSSIBLY ENHANCED PCPN ALONG/NORTH OF THE LOW TRACK FROM ERN KY ACRS
THE VIRGINIAS TO THE DELMARVA...AS UPPER LEVEL JET STREAK BECOMES
WELL-DEFINED. THIS SYSTEM SHOULD EXIT OFFSHORE THURS NGT AS HIGH
PRES OVERSPREADS THE REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODEL AND ENSEMBLE GUID STARTS THE PERIOD IN MUCH
BETTER AGREEMENT COMPARED TO YESTERDAY...SHOWING A HIGHLY AMPLIFIED
WEST COAST RIDGE/ROCKIES-PLAINS TROUGH CONFIGURATION WITH CONFLUENT
ZONAL FLOW DOWNSTREAM IN THE EAST. INDIVIDUAL SOLUTION SPREAD GROWS
QUICKLY IN TIME AND THE GUIDANCE BECOMES RATHER CHAOTIC WITH
VIRTUALLY NO RUN-TO-RUN CONSISTENCY. THE GFS/GEFS ARE QUICKER TO
EJECT THE PLAINS ENERGY EWD INTO THE OH VLY BY THE END OF THE PD
WHILE THE ECMWF LEAVES BEHIND SIGNIFICANT ENERGY IN THE SWRN CONUS.
GIVEN THE HIGH UNCERTAINTY IN THE EVOLUTION OF THE LARGE SCALE FLOW
FORECASTER CONFIDENCE REMAINS LOW. THEREFORE...THE LONG TERM GRIDS
WERE DERIVED USING A NEAR EQUAL BLEND OF HPC/GMOS AND GFS/ECMWF
GUIDANCE WHICH FAVORS NEAR TO ABOVE AVG TEMPERATURES AND A GRADUAL
INCREASE IN POPS FROM LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
A WARM FRONT OVR THE OHIO VALLEY WILL LIFT NORTHEAST THRU CENTRAL
PA LATE TONIGHT. JUST ENOUGH LIFT AHEAD OF THIS BOUNDARY TO
PERHAPS PRODUCE A BIT OF VERY LIGHT SNOW AT BFD THIS EVENING.
OTHERWISE...MDL DATA AND UPSTREAM OBS BOTH STRONGLY INDICATING VFR
CONDS OVERNIGHT WITH CLOUD BASES ARND 10KFT. BIGGEST AVIATION
CONCERN TONIGHT WILL BE DEVELOPING LLWS...THE RESULT OF STRONG
WSWRLY LOW LVL JET OVERSPREADING THE AREA...IN CONJUNCTION WITH
MUCH LIGHTER SOUTHERLY WINDS AT GROUND LEVEL. LATEST RUC 0-0.5KM
BULK SHEAR SUGGESTS ONSET OF LLWS CRITERIA WILL RANGE FROM
00Z-04Z FROM WEST TO EAST. SFC WARM FRONT MAY WORK INTO JST BY
ARND MIDNIGHT...RESULTING IN GUSTY SW WINDS AND DIMINISHED LLWS
THERE LATE TONIGHT.
FOR THE BULK OF CENTRAL PA...WARM FRONT WILL LIFT NORTH OF THE
AREA BY LATE AM...RESULTING IN A DECREASING THREAT OF LLWS BUT
INCREASING SW WINDS AT THE SFC /MDL SOUNDINGS SUPPORT GUSTS TO NR
25KTS/. ALL MDL DATA POINTING TOWARD A HIGH DEGREE OF CONFIDENCE IN
VFR CONDS TUESDAY WITH THE POSSIBLE EXCEPTION OF LATE DAY MVFR
CIGS AT BFD.
OUTLOOK...
WED...AM LOW CIGS/SHRA POSS W MTNS.
THU...AM FOG POSSIBLE...ESP W MTNS.
FRI-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...RXR
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
924 PM CST MON JAN 30 2012
.SHORT TERM UPDATE...
SHORTWAVE DISTURBANCE MOVING ACROSS THE EASTERN DAKOTAS INTO
CENTRAL MINNESOTA GENERATING SOME SCATTERED VERY LIGHT MIX WEST
OF DLH THIS EVENING. LATEST MODEL GUIDANCE STILL INSISTS THAT BULK
OF MEASURABLE LIGHT PRECIPITATION WILL GENERALLY REMAIN NORTH OF
THE WISCONSIN MICHIGAN BORDER OVERNIGHT. GRB...MPX...DVN AND ILX
SOUNDINGS RATHER DRY AND APPEARS BEST LIFT...ALBEIT WEAK SHOULD
REMAIN NORTH OF THE FORECAST AREA. HOWEVER WILL CONTINUE TO
MONITOR RADAR TRENDS UPSTREAM FOR SMALL PROBABILITY PRECIP CLIPS
FAR NORTHERN COUNTIES.
ELSEWHERE...DID LOWER TEMPS A FEW DEGREES OVERNIGHT AS THIN HIGH
CLOUDS AND LIGHTS WINDS HAVE ALLOWED TEMPS TO FALL INTO THE UPPER
TEENS OVER PARTS OF LINCOLN AND LANGLADE COUNTIES AND INTO THE LOW
TO MID 20S IN PARTS OF THE CENTRAL AND NORTHEAST FORECAST AREA. AS
UPPER SYSTEM CONTINUES TO APPROACH THE FORECAST AREA
OVERNIGHT...EXPECT HIGH-MID CLOUDS TO THICKEN SOME AND TEMPS
SHOULD BECOME STEADY OR PERHAPS RISE AFTER MIDNIGHT.
ESB
&&
.PREV DISCUSSION...ISSUED AT 628 PM CST MON JAN 30 2012...
SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LIGHT SNOW
ASSOCIATED WITH A MID-LEVEL FGEN BAND ALONG AN ELEVATED WARM FRONT
HAS RAPIDLY PUSHED TO THE EAST EARLY THIS AFTERNOON LEAVING
WIDESPREAD MID AND HIGH CLOUDS OVERHEAD. THE SURFACE WARM FRONT IS
STILL LAGGING BEHIND FROM MINNEAPOLIS TO CHICAGO...BUT SE WINDS
NORTH OF THE BOUNDARY HAS BROUGHT WARMER MARINE AIR INTO
NORTHEAST WISCONSIN WHERE TEMPS HAVE REACHED INTO THE MIDDLE 30S.
DESPITE THE WARM ADVECTION...NO SIGN OF ANY STRATUS/DRIZZLE/FOG
DEVELOPMENT UPSTREAM SO FAR...BUT THE ABOVE 30F DEWPOINTS ARE NOW
REACHING INTO EASTERN IOWA AND NORTHERN ILLINOIS. AS WARM ADVECTION
CONTINUES UNABATED AHEAD OF LOW PRESSURE DEVELOPING OVER THE
NORTHERN ROCKIES...LOW STRATUS AND FOG POTENTIAL ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...A SHORTWAVE TROUGH WILL MOVE ACROSS THE DAKOTAS AND PUSH
SURFACE LOW PRESSURE OVER THE NORTHERN MISSISSIPPI VALLEY. AHEAD OF
THE LOW...H850 WARM FRONT WILL LIFT ACROSS THE U.P. INTO
LAKE SUPERIOR. THE THREAT OF PRECIP WILL BE LOCATED ALONG THIS
BOUNDARY AND NORTH OF THE FORECAST AREA...SO HAVE REMOVED POPS FOR
TONIGHT. WILL STILL HAVE PLENTY OF MID AND UPPER MOISTURE AROUND
CARRIED IN BY THE JET STREAM TO MAKE FOR A PARTLY TO MOSTLY CLOUDY
NIGHT. THE BIGGEST FORECAST CHALLENGE TONIGHT WILL BE THE
POSSIBILITY OF FOG OR LOW STRATUS DEVELOPMENT LATE. SSW WILL CARRY
DEWPOINTS IN THE UPPER 20S TO LOWER 30S OVER THE MID-MISSISSIPPI
VALLEY INTO THE REGION TONIGHT. THE NAM IN PARTICULAR IS BULLISH ON
CREATING LOW STRATUS OR FOG BUT COULD BE ONE OF THOSE SCENARIOS
WHERE TEMPS JUST ABOVE THE SURFACE RISE COINCIDENT WITH DEW POINTS
WHICH WOULD CREATE SOME LOWER VSBYS AND FROST DEPOSITS BUT WITHOUT
ANY FOG OR STRATUS. NOT SEEING MUCH POTENTIAL FOR DRIZZLE AS THE
MOISTURE DOESNT APPEAR DEEP ENOUGH. SO WILL PUNT IT OFF TO THE
EVENING CREW UNTIL CAN SEE THE WHITES OF ITS EYES. WITH THE WARM
ADVECTION...LOW TEMPS WILL NOT FALL MUCH...FROM THE MID 20S NORTH TO
LOW 30S SE.
TUESDAY...LOW PRESSURE WILL CONTINUE TO TRACK EAST ALONG THE WARM
FRONT OVER THE U.P. SOUTH OF THE LOW TRACK...GULF MOISTURE WILL
SURGE NORTHEAST BUT LOOKS TO BYPASS THE REGION INTO LOWER MICHIGAN.
AS A RESULT...OUR AIR WILL ARRIVE FROM THE DRIER SOUTHERN GREAT
PLAINS WHICH WILL KEEP THE MID-LEVELS DRY DESPITE A WEAK PACIFIC
COOL FRONT PASSING ACROSS THE AREA IN THE AFTERNOON. AFTER SOME
MORNING MIST OR LOW STRATUS...SHOULD SEE PARTLY TO MOSTLY CLOUDY
SKIES ACROSS THE AREA IN THE AFTERNOON. HIGHS WILL BE WARM AFTER A
MILD START TO THE DAY...WITH HIGHS RANGING FROM THE UPPER 30S NORTH
TO MIDDLE 40S SOUTH.
LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. MILD WEATHER WILL
CONTINUE THROUGH THE REMAINDER OF THE WEEK AND INTO EARLY NEXT
WEEK. CLOUD COVER AND TEMPERATURES ARE THE PRIMARY CHALLENGE
THROUGH SATURDAY AS THERE IS LITTLE CHANCE OF ANY PRECIPITATION.
THE VERY MILD TEMPERATURES AND MELTING SNOW WILL LIKELY PRODUCE
LOW CLOUDS AND FOG AT SOME POINT...ESPECIALLY IN NORTHERN
WISCONSIN WHERE SNOW COVER IS A FOOT OR SO. BUT NOT CERTAIN ENOUGH
ABOUT WHEN THIS MIGHT OCCUR SO DID NOT MENTION ANY FOG IN THE
FORECAST. WE DO EXPECT SOME BY LATER IN THE WEEK.
THE MODELS DO BRING SOME SOUTHERN STREAM JET ENERGY FROM FOUR
CORNERS AREA FRIDAY INTO THE CENTRAL PLAINS SATURDAY AND SUNDAY.
THE EVOLUTION OF THE SYSTEM IS DIFFERENT FROM MODEL TO MODEL AND
RUN TO RUN SO DO NOT HAVE A LOT OF CONFIDENCE AT THIS POINT. THE
GFS SOLUTIONS COULD PRODUCE CONSIDERABLE SNOW OVER WESTERN
WISCONSIN IF IT WOULD VERIFY. THERE IS SOME DECENT AGREEMENT NOW
THAT AN UPPER RIDGE WILL FORM OVER THE WESTERN PART OF NORTH
AMERICA WITH A TROUGH EAST OF ROCKIES. THE MODELS HAVE ADVERTISED
THIS A COUPLE OF TIMES THIS WINTER BUT IT HAS NOT MATERIALIZED.
&&
.AVIATION...SURFACE WARM FRONT POSITIONED NW-SE ACROSS THE
SOUTHERN PORTION OF WISCONSIN FROM NEAR MKE-MSP EARLY THIS
EVENING. LITTLE LARGE-SCALE FORCING AND WITH MID-LEVELS RATHER
DRY...MAINLY JUST BROKEN HIGH CLOUDS WITH SOME SCT MID-LEVEL
CLOUDS. SOUTH OF THE WARM FRONT...SURFACE DEW POINTS STARTING TO CREEP UP
ACROSS SOUTHERN WISCONSIN ON LIGHT SOUTH WINDS. WILL CONTINUE TO
MONITOR POSSIBILITY OF LOW STRATUS FORMATION LATER TONIGHT...BUT
CONFIDENCE REMAINS LOW...THUS DID NOT INCLUDE IN 00Z TAFS.
VFR CONDITIONS EXPECTED ON TUESDAY. OTHER THAN SOME BKN MID-LEVEL
CLOUDINESS AND A GRADUALLY VEERING BOUNDARY LAYER WIND TO WESTERLY
ACCOMPANING A WEAK FRONTAL PASSAGE LATER IN THE
AFTERNOON...WEATHER GENERALLY NIL.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
628 PM CST MON JAN 30 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LIGHT SNOW
ASSOCIATED WITH A MID-LEVEL FGEN BAND ALONG AN ELEVATED WARM FRONT
HAS RAPIDLY PUSHED TO THE EAST EARLY THIS AFTERNOON LEAVING
WIDESPREAD MID AND HIGH CLOUDS OVERHEAD. THE SURFACE WARM FRONT IS
STILL LAGGING BEHIND FROM MINNEAPOLIS TO CHICAGO...BUT SE WINDS
NORTH OF THE BOUNDARY HAS BROUGHT WARMER MARINE AIR INTO
NORTHEAST WISCONSIN WHERE TEMPS HAVE REACHED INTO THE MIDDLE 30S.
DESPITE THE WARM ADVECTION...NO SIGN OF ANY STRATUS/DRIZZLE/FOG
DEVELOPMENT UPSTREAM SO FAR...BUT THE ABOVE 30F DEWPOINTS ARE NOW
REACHING INTO EASTERN IOWA AND NORTHERN ILLINOIS. AS WARM ADVECTION
CONTINUES UNABATED AHEAD OF LOW PRESSURE DEVELOPING OVER THE
NORTHERN ROCKIES...LOW STRATUS AND FOG POTENTIAL ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...A SHORTWAVE TROUGH WILL MOVE ACROSS THE DAKOTAS AND PUSH
SURFACE LOW PRESSURE OVER THE NORTHERN MISSISSIPPI VALLEY. AHEAD OF
THE LOW...H850 WARM FRONT WILL LIFT ACROSS THE U.P. INTO
LAKE SUPERIOR. THE THREAT OF PRECIP WILL BE LOCATED ALONG THIS
BOUNDARY AND NORTH OF THE FORECAST AREA...SO HAVE REMOVED POPS FOR
TONIGHT. WILL STILL HAVE PLENTY OF MID AND UPPER MOISTURE AROUND
CARRIED IN BY THE JET STREAM TO MAKE FOR A PARTLY TO MOSTLY CLOUDY
NIGHT. THE BIGGEST FORECAST CHALLENGE TONIGHT WILL BE THE
POSSIBILITY OF FOG OR LOW STRATUS DEVELOPMENT LATE. SSW WILL CARRY
DEWPOINTS IN THE UPPER 20S TO LOWER 30S OVER THE MID-MISSISSIPPI
VALLEY INTO THE REGION TONIGHT. THE NAM IN PARTICULAR IS BULLISH ON
CREATING LOW STRATUS OR FOG BUT COULD BE ONE OF THOSE SCENARIOS
WHERE TEMPS JUST ABOVE THE SURFACE RISE COINCIDENT WITH DEW POINTS
WHICH WOULD CREATE SOME LOWER VSBYS AND FROST DEPOSITS BUT WITHOUT
ANY FOG OR STRATUS. NOT SEEING MUCH POTENTIAL FOR DRIZZLE AS THE
MOISTURE DOESNT APPEAR DEEP ENOUGH. SO WILL PUNT IT OFF TO THE
EVENING CREW UNTIL CAN SEE THE WHITES OF ITS EYES. WITH THE WARM
ADVECTION...LOW TEMPS WILL NOT FALL MUCH...FROM THE MID 20S NORTH TO
LOW 30S SE.
TUESDAY...LOW PRESSURE WILL CONTINUE TO TRACK EAST ALONG THE WARM
FRONT OVER THE U.P. SOUTH OF THE LOW TRACK...GULF MOISTURE WILL
SURGE NORTHEAST BUT LOOKS TO BYPASS THE REGION INTO LOWER MICHIGAN.
AS A RESULT...OUR AIR WILL ARRIVE FROM THE DRIER SOUTHERN GREAT
PLAINS WHICH WILL KEEP THE MID-LEVELS DRY DESPITE A WEAK PACIFIC
COOL FRONT PASSING ACROSS THE AREA IN THE AFTERNOON. AFTER SOME
MORNING MIST OR LOW STRATUS...SHOULD SEE PARTLY TO MOSTLY CLOUDY
SKIES ACROSS THE AREA IN THE AFTERNOON. HIGHS WILL BE WARM AFTER A
MILD START TO THE DAY...WITH HIGHS RANGING FROM THE UPPER 30S NORTH
TO MIDDLE 40S SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. MILD WEATHER WILL
CONTINUE THROUGH THE REMAINDER OF THE WEEK AND INTO EARLY NEXT
WEEK. CLOUD COVER AND TEMPERATURES ARE THE PRIMARY CHALLENGE
THROUGH SATURDAY AS THERE IS LITTLE CHANCE OF ANY PRECIPITATION.
THE VERY MILD TEMPERATURES AND MELTING SNOW WILL LIKELY PRODUCE
LOW CLOUDS AND FOG AT SOME POINT...ESPECIALLY IN NORTHERN
WISCONSIN WHERE SNOW COVER IS A FOOT OR SO. BUT NOT CERTAIN ENOUGH
ABOUT WHEN THIS MIGHT OCCUR SO DID NOT MENTION ANY FOG IN THE
FORECAST. WE DO EXPECT SOME BY LATER IN THE WEEK.
THE MODELS DO BRING SOME SOUTHERN STREAM JET ENERGY FROM FOUR
CORNERS AREA FRIDAY INTO THE CENTRAL PLAINS SATURDAY AND SUNDAY.
THE EVOLUTION OF THE SYSTEM IS DIFFERENT FROM MODEL TO MODEL AND
RUN TO RUN SO DO NOT HAVE A LOT OF CONFIDENCE AT THIS POINT. THE
GFS SOLUTIONS COULD PRODUCE CONSIDERABLE SNOW OVER WESTERN
WISCONSIN IF IT WOULD VERIFY. THERE IS SOME DECENT AGREEMENT NOW
THAT AN UPPER RIDGE WILL FORM OVER THE WESTERN PART OF NORTH
AMERICA WITH A TROUGH EAST OF ROCKIES. THE MODELS HAVE ADVERTISED
THIS A COUPLE OF TIMES THIS WINTER BUT IT HAS NOT MATERIALIZED.
&&
.AVIATION...SURFACE WARM FRONT POSITIONED NW-SE ACROSS THE
SOUTHERN PORTION OF WISCONSIN FROM NEAR MKE-MSP EARLY THIS
EVENING. LITTLE LARGE-SCALE FORCING AND WITH MID-LEVELS RATHER
DRY...MAINLY JUST BROKEN HIGH CLOUDS WITH SOME SCT MID-LEVEL
CLOUDS. SOUTH OF THE WARM FRONT...SURFACE DEW POINTS STARTING TO CREEP UP
ACROSS SOUTHERN WISCONSIN ON LIGHT SOUTH WINDS. WILL CONTINUE TO
MONITOR POSSIBILITY OF LOW STRATUS FORMATION LATER TONIGHT...BUT
CONFIDENCE REMAINS LOW...THUS DID NOT INCLUDE IN 00Z TAFS.
VFR CONDITIONS EXPECTED ON TUESDAY. OTHER THAN SOME BKN MID-LEVEL
CLOUDINESS AND A GRADUALLY VEERING BOUNDARY LAYER WIND TO WESTERLY
ACCOMPANING A WEAK FRONTAL PASSAGE LATER IN THE
AFTERNOON...WEATHER GENERALLY NIL.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
EB
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
219 PM CST SUN JAN 29 2012
.SYNOPSIS...MORE MILD WEATHER.
MODEST LARGE SCALE TROF OVER THE ERN CONUS WL SHIFT NEWD THE NEXT
COUPLE DAYS...PUTTING US BACK INTO WHAT HAS BECOME THE PATTERN OF
THE WINTER...A BROAD SOMEWHAT SPLIT ZONAL REGIME. HEIGHTS OVER WRN
CANADA WL GRADUALLY RISE LATER THIS WK. THAT WL EVENTUALLY FAVOR A
RETURN TO AN ERN TROF. MODELS OFFERED VARYING IDEAS ON HOW
SHARP/STG THE WRN RIDGE WL BECOME...AND THAT WILL MODULATE THE
STRENGTH OF THE DOWNSTREAM TROF. PERSISTENCE WOULD FAVOR THE
LESS AMPLIFIED OF THE GUIDANCE SOLUTIONS.
AFTER A RELATIVELY COLD NGT TNGT...TEMPS WL WARM TO SIGNIFICANTLY
ABV NORMAL LEVELS AGAIN FOR THE EARLY PART OF THE FCST PERIOD.
THEY WL DROP BACK CLOSER TO NORMAL BY NEXT WEEKEND...BUT UNLESS
ERN TROF GETS A LOT DEEPER THAN NOW EXPECTED...IT/S HARD TO SEE
THEM GOING BLO NORMAL. THE FCST AREA WL PROBABLY HAVE A COUPLE LGT
PCPN EVENTS...WITH AMNTS PROBABLY ENDING UP BLO NORMAL FOR THE
PERIOD AS A WHOLE.
&&
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE WORKING EASTWARD ACROSS THE NORTHERN MISSISSIPPI VALLEY
EARLY THIS AFTERNOON. LOW STRATO-CU CLOUD DECK IS SLOWLY LIFTING
OFF TO THE NORTHEAST OVER NORTHEAST WISCONSIN...WHILE THE REST OF
THE REGION REMAINS SUNNY. LOOKING UPSTREAM...PRETTY EXPANSIVE CLOUD
SHIELD IS PRESSING EAST ACROSS THE DAKOTAS...JUST AHEAD OF A
DEVELOPING SURFACE WARM FRONT. AS THE WARM FRONT MOVES EAST ACROSS
THE REGION LATE TONIGHT INTO MONDAY...PRECIP TIMING AND AMOUNTS ARE
THE MAIN FORECAST CONCERNS.
TONIGHT...THE HIGH PRESSURE RIDGE AXIS WILL SLIDE ACROSS THE STATE
DURING THE EVENING HOURS. SHOULD SEE A PERIOD OF CLEAR SKIES AND
LIGHT WINDS THAT WOULD ALLOW TEMPS TO TAKE A TUMBLE. WENT ON THE
COLD SIDE OF GUIDANCE FOR THIS REASON...AS IT USUALLY DOESNT TAKE
MUCH TIME FOR TEMPS TO FALL 20 DEGREES...ESPECIALLY OVER
NORTH-CENTRAL WISCONSIN. THEREAFTER...A 850MB WARM FRONT OVER THE
NORTHERN PLAINS WILL SHIFT EAST INTO SOUTHWEST WISCONSIN AFTER
MIDNIGHT. MODELS HAVE A VARIETY OF ARRIVAL TIMINGS OF THE LIGHT
SNOW AS IT SPREADS SE ALONG THE FRONT INTO CENTRAL WISCONSIN LATE.
DONT REALLY HAVE A GOOD FEEL IF THE FASTER PACE OF THE GFS COMPARED
TO THE NAM IS LIKELY TO BE CORRECT. SO WENT MIDDLE OF THE ROAD FOR
POPS/QPF WHICH PLACES LIKELY POPS OVER NORTH-CENTRAL AND CENTRAL
WISCONSIN. PERHAPS CENTRAL WISCONSIN COULD SEE A QUICK HALF INCH OF
FLUFF BY 12Z. TEMPS SHOULD REBOUND ONCE THE CLOUDS ROLL IN...SO
MIDNIGHT LOWS WILL CREEP BACK UP THROUGH THE OVERNIGHT.
MONDAY...THE WARM FRONT WILL CONTINUE TO MOVE EAST ACROSS THE REGION
ON MONDAY. WILL SEE THE MOST WIDESPREAD SNOW DURING THE MORNING
HOURS WHEN A DECENT BAND OF MID-LEVEL FGEN MOVES OVERHEAD. MOST
PLACES WILL SEE 1-2 INCHES OF SNOW. THE PRIMARY UNCERTAINTY OF THE
EVENT WILL BE THE PTYPE ON THE BACK EDGE OF THE PRECIPITATION SHIELD
WHEN MOISTURE FALLS BELOW -10C...WHICH INCREASES THE PROBABILITY OF
THE ABSENCE OF ICE CRYSTALS IN THE CLOUD. WITH CLOUD COVER AND
PRECIP HOLDING BACK SURFACE TEMPS...THINK THERE COULD BE A RIBBON OF
FREEZING DRIZZLE...MAINLY OVER CENTRAL AND EAST-CENTRAL WISCONSIN ON
THE BACK EDGE. BUT DONT THINK IT WILL POSE A HAZARD AS THE FRONT IS
RELATIVELY FAST MOVING AND SHARP...AS OPPOSED TO A LONG DURATION
OVER-RUNNING EVENT. TEMPS MAY REACH ABOVE FREEZING OVER CENTRAL AND
E-C WISCONSIN AS THE PRECIP ENDS AND CLOUDS ERODE HERE FIRST LATE IN
THE AFTERNOON.
.LONG TERM...MON NGT THROUGH NEXT SUN. THE MESO WRF RUNS FM NCEP
SUGGESTED SOME LGT PCPN COULD STILL LINGER IN THE THE NE EARLY MON
NGT...BUT WITH LITTLE SUPPORT FM ANY OF THE OTHER MODELS STUCK
WITH A DRY FCST. MILD SLY FLOW WL PREVENT MUCH DROP IN TEMPS...SO
BUILT 3 HOURLY TEMP GRIDS FROM A ROBUST BLEND OF GUID PRODUCTS AND
THEN GENERATED MIN GRID FROM THAT.
TUE WAS THE MOST CHALLENGING DAY OF THE FCST PERIOD. WK CYCLONE WL
BE TRACKING EWD ALONG THE U.S. CANADIAN BORDER TOWARD LAKE
SUPERIOR...WITH FCST AREA BASICALLY IN THE WARM SECTOR. OVERALL...
FORCING FOR PCPN WEAK. BUT SOME QG FORCING FM UPR SHRTWV COULD
GENERATE SOME LGT PCPN ACRS THE NW PART OF THE FCST AREA DURING
THE AFTN. CONTD SLGT CHC OF RA/SN TO ACCOUNT FOR THAT. MAIN
QUESTION HOWEVER IS THE CLDS AND THEIR IMPACT ON TEMPS. IT COULD
BE A VERY MILD DAY IF WE CAN ESCAPE HAVING ST FORM ACRS THE AREA.
IF THE ST DOES FORM...IT WL LIMIT TEMPS AND DAMP SLY FLOW WL
PROBABLY MAKE IT SEEM COLDER THAN IT IS. STUCK WITH MAX TEMPS FM
PREV FCST WHICH WERE GENERALLY BLO WHAT BEST PERFORMING GUID WOULD
SUGGEST FOR HIGH TEMPS. INCOMING DWPTS IN THE LOWER TO MIDDLE 30S
MARGINAL FOR ST FORMATION...AND DIDN/T WANT TO TAKE TEMPS BEYOND
WHAT WE HAD GOING WITHOUT HAVING MORE CONFIDENCE THAT WE WOULDN/T
GET STUCK WITH LOW CLDS.
QUIET WX THEN EXPECTED TUE NGT AND WED AS THE CYCLONE PASSES OFF
TO THE E OF THE RGN.
&&
.AVIATION...HIGH PRESSURE WILL MOVE AND DRIFT OVER THE AREA THROUGH
THIS EVENING. AS THE HIGH APPROACHES...MVFR CLOUD DECK OVER
NORTHERN AND NORTHEAST WISCONSIN WILL LIFT OFF TO THE NORTHEAST THIS
AFTERNOON LEAVING VFR CONDITIONS IN ITS WAKE. VFR CONDITIONS THIS
EVENING BEFORE CLOUDS WILL BE ON THE INCREASE AND LOWERING AHEAD OF
A WARM FRONT. LIGHT SNOW IS EXPECTED TO DEVELOP AND EXPAND ALONG
THE FRONT LATE TONIGHT INTO TOMORROW MORNING ACROSS THE REGION.
THOUGH MODELS GENERALLY AGREE WITH THE SNOW AMOUNTS...THEY DIFFER IN
REGARDS TO THE ARRIVAL OF THE SNOW. TRIED TO PLAY THE MIDDLE OF THE
ROAD...WHICH BRINGS THE SNOW INTO CENTRAL WISCONSIN LATE TONIGHT AND
INTO EASTERN WISCONSIN TOMORROW MORNING. CIGS AND VSBYS SHOULD
EASILY FALL TO IFR LEVELS IN THE SNOW...AND PROBABLY LIFR OVER
CENTRAL AND NORTHERN WISCONSIN. SOME PATCHY FREEZING DRIZZLE
POSSIBLE ON THE BACKSIDE OF THE SNOW OVER CENTRAL WISCONSIN BY
MIDDAY.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/SKOWRONSKI
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1051 PM CST SAT JAN 28 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SYNOPSIS...MORE OF WHAT HAS COME TO BE THE NORM FOR THIS
WINTER...ABOVE NORMAL TEMPERATURES WITH ONLY A COUPLE MODEST PCPN
EVENTS.
UPR PATTERN CURRENTLY FEATURES MODEST TROF OVER THE N-C CONUS...
BUT FLOW WL FLATTEN BACK TO ZONAL REGIME DURING THE NEXT COUPLE
DAYS. MED RANGE MODELS AGREEDED IN GRADUALLY BUILDING SOME RIDGING
OVER WRN CANADA DURING THE LATTER PART OF THE FCST PERIOD. BUT RIDGE
NEVER SEEMS TO GET STG/SHARP ENOUGH TO FORCE A DISTINCT DOWNSTREAM
TROF OVER ERN CONUS. SO WL PROBABLY CONT WITH GENERAL WLY FLOW AND
FAIRLY HIGH UPR HGTS.
OTHER THAN A COUPLE GLANCING SHOTS OF COLDER AIR BEHIND INDIVIDUAL
WX SYSTEMS...THE FCST AREA WL PRIMARILY BE DOMINATED BY PACIFIC
AIR. THAT WL RESULT IN ABV NORMAL TEMPS. PATTERN WL SUPPORT A FEW
PCPN PRODUCING SYSTEMS...BUT NO STG STORMS IN THE OFFING.
&&
.SHORT TERM...TONIGHT AND SUNDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE STATE
OF WISCONSIN LOCATED BETWEEN LOW PRESSURE OVER THE ONTARIO/QUEBEC
BORDER AND HIGH PRESSURE SITUATED OVER THE SOUTHERN PLAINS.
CYCLONIC FLOW AND THERMAL TROUGHING BETWEEN THESE FEATURES ARE
CONTRIBUTING TO A WIDESPREAD STRATO-CU FIELD STRETCHING FROM
NORTHERN MINNESOTA TO LOWER MICHIGAN. PLENTY OF SNOW SHOWER ACTIVITY
WITHIN THE COLDER CLOUD TOPS OVER NORTH-CENTRAL WISCONSIN AND THE
WESTERN UPPER PENINSULA EARLY THIS AFTERNOON. THE NEXT SHORTWAVE IS
OBSERVED PUSHING INTO NORTH DAKOTA WHICH WILL HEAD FOR THE REGION
TONIGHT. PRECIP CHANCES WITH THIS FEATURE AND CLOUD COVER ARE THE
MAIN FORECAST CONCERNS OVER THE NEXT 24 HOURS.
TONIGHT...SHORTWAVE TROUGH OVER THE DAKOTAS IS NOW EXPECTED TO TAKE
A SLIGHTLY MORE SOUTHERLY TRACK THAN PROJECTED YESTERDAY...FROM
ABOUT EASTERN SOUTH DAKOTA TO NORTHERN ILLINOIS. THOUGH THE WAVE
WILL STILL HAVE GOOD QG FORCING WITH IT...THE MORE SOUTHERLY TRACK
WILL SHIFT THE COMMA HEAD OF THE COMPACT WAVE OVER SOUTHERN
WISCONSIN RATHER THAN CENTRAL WISCONSIN. AS A RESULT...HAVE REMOVED
POPS FROM CENTRAL AND EAST-CENTRAL WISCONSIN TONIGHT.
OTHERWISE...CYCLONIC FLOW SUBTLY BROADENS OUT TONIGHT...WHICH SHOULD
ALLOW THE LOW STRATO-CU TO RETREAT TO THE NORTH. PLENTY OF FLURRY
ACTIVITY UPSTREAM WILL FORCE ME TO KEEP A MENTION OVER N-C
WISCONSIN. LOW LEVEL WINDS ARE TOO WESTERLY HOWEVER TO HAVE MUCH OF
A LAKE INFLUENCE. LOWS WILL RANGE FROM THE MIDDLE SINGLE DIGITS
ABOVE ZERO NORTH TO THE MID TEENS SOUTHEAST.
SUNDAY...MID-LEVEL CLOUDS FROM THE SHORTWAVE WILL DEPART TO THE
SOUTHEAST EARLY SUNDAY MORNING WHICH MAY LEAVE A PERIOD OF MOSTLY
SUNNY CONDITIONS OVER CENTRAL AND EAST-CENTRAL WISCONSIN TO START
THE DAY. LOW LEVEL WINDS WILL TURN BACK TO THE NORTHWEST BEHIND THE
DEPARTING WAVE. AS THIS OCCURS...COLD ADVECTION WILL RESUME WHICH
SHOULD LEAD TO ANOTHER SURGE SOUTHEAST OF THE LOW STRATO-CU LATE
MORNING INTO EARLY AFTERNOON. WINDS THEN BACK AROUND TO THE WEST MID
TO LATE AFTERNOON AS THE SURFACE RIDGE APPROACHES. SHOULD SEE THE
STRATO-CU BREAK UP SOME AS DRIER AIR PUSHES IN FROM THE WEST. HIGH
TEMPS RANGING FROM THE MID TEENS NORTH TO THE LOWER 20S SOUTHEAST.
.LONG TERM...SUN NGT THROUGH NEXT SAT. TEMPS WL PROBABLY FALL OFF
FAIRLY QUICKLY EARLY SUN NGT WITH SFC RIDGE COMING ACRS THE
AREA...BUT THEN START TO RISE AS CLDS INCR. ISENT LIFT WL SWEEP
EWD ACRS THE AREA LATE AT NGT AND MON MORNING. MODELS SEEMED A BIT
SLOWER WITH THE PCPN...SO TWEAKED TIMING BACK A BIT. TOOK THE N UP
TO LIKELIES MON MORNING. WL PROBABLY GET A COUPLE INCHES OF SNOW
ACRS THE N...AND MAYBE AN INCH OR SO IN THE S. PCPN WL PROBABLY
TAPER OFF TO FZDZ/DZ AS MIDDLE LEVEL MOISTURE GETS STRIPPED OFF TO
THE NE.
12Z RUN OF THE ECMWF BACKED OFF WITH PCPN CHCS TUE. THE OTHER
MODELS ALREADY WERE TAMER. MAY VERY WELL GET BY WITHOUT ANY PCPN
AS FCST AREA WL JUST BE IN THE WARM SECTOR OF WK CYCLONE TRACKING
ALONG THE U.S/CANADIAN BORDER. BUT DIDN/T WANT TO COMPLETELY PULL
PCPN WITH SYSTEM CROSSING THE RGN...SO SETTLED FOR TRENDING POPS
DOWN.
&&
.AVIATION...
UPPER-LEVEL DISTURBANCE OVER SOUTHERN MINNESOTA WILL PASS SOUTH OF
THE FORECAST AREA OVERNIGHT. GENERALLY VFR CIGS WITH SOME
SCATTERED MVFR AFTER 09Z ESPECIALLY AT RHI...CWA AND AUW.
VFR CONDITIONS TO PREVIAL AFTER ABOUT 16Z SUNDAY AS HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
EB
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
403 AM EST TUE JAN 31 2012
.SHORT TERM...TODAY THROUGH THURSDAY...
EARLY THIS MORNING...HIGH PRESSURE RIDGE STILL HANGING ON WITH DRY
ENOUGH AIRMASS TO ALLOW FOR TEMPS IN THE 30S ACROSS INLD SE GA AND
INLD NE FL WITH SOME PATCHY FROST ACROSS SOME LOCATIONS. A FEW WISPS
OF CIRRUS JUST STARTING TO PUSH INTO THE REGION. NO DOUBT SOME
PATCHY SMOKE NEAR WILDFIRE LOCATIONS IN INLD NE FL...BUT NOT ENOUGH
CONFIDENCE TO ISSUE ANY SPECIFIC DENSE SMOKE ADVISORY AT THIS
TIME...WILL CONTINUE TO MONITOR FOR POSSIBLE ADVISORY AROUND SUNRISE
OR ISSUE SPS TO COVER ANY LOCALIZED SMOKE ISSUES.
TODAY...HIGH CLOUDS TO OVERSPREAD THE REGION WITH LLVL FLOW BECOMING
SOUTHEAST AND TEMPS WARMING INTO THE LOWER/MID 70S INLAND AND 60S
ALONG THE COAST.
TONIGHT...CLOUDS CONTINUE TO INCREASE AHEAD OF NEXT SYSTEM WITH MUCH
MILDER OVERNIGHT LOWS IN THE 40S/50S. PATCHY FOG/SMOKE POSSIBLE
DURING THE LATE NIGHT HOURS.
WEDNESDAY...MODELS STILL IN GOOD AGREEMENT WITH PCPN BREAKING OUT
AHEAD OF DEVELOPING WEAK LOW IN THE NORTHERN GOMEX AND SPREADING
INTO THE REGION WHICH APPEARS TO BE MAINLY LIGHT AT THIS TIME. MORE
CLOUD COVER HAS TRENDED MAX TEMP FORECAST SLIGHTLY DOWNWARD...MAINLY
IN THE LOWER/MID 70S.
WED NIGHT...GOOD ISENTROPIC LIFT AHEAD OF SYSTEM AND RR QUAD OF
UPPER LEVEL JET WILL ENHANCE RAINFALL CHANCES WITH LIKELY POPS
ACROSS SE GA AND AT LEAST CHANCE POPS FOR NE FL. RAINFALL AMOUNTS OF
A TENTH TO A QUARTER OF AN INCH ARE EXPECTED.
THURSDAY...AS WEAK LOW TRACKS ACROSS THE FORECAST AREA...SCATTERED
TO NUMEROUS SHOWERS IN THE MORNING WILL SLOWLY DECREASE IN COVERAGE
DURING THE AFTERNOON HOURS. MAX TEMPS EXPECTED INTO THE 70S...BUT
WILL DEPEND ON HOW FAST LOW TRACKS ACRS THE REGION AND AMOUNT OF
PARTIAL CLEARING EXPECTED DURING THE AFTERNOON HOURS.
.LONG TERM...FRIDAY THROUGH MONDAY...
FRIDAY...WITH TRAILING FRONT STALLED ACROSS CNTRL FL IN THE
MORNING...ONLY A SLIGHT CHANCE OF SHOWERS BY THE AFTERNOON/EVENING
AS ISENTROPIC LIFT BEGINS ALONG FRONTAL BOUNDARY AS IT LIFTS TO THE
NORTH. MAX TEMPS STILL ABOVE NORMAL IN THE LOWER TO MID 70S.
SATURDAY...FRONT SHOULD LIFT NORTH INTO MIDDLE/SOUTH GEORGIA REGION
WITH SOME SCTD SHOWER/ISOLD TSTM ACTIVITY POSSIBLE IN THE WARM
SECTOR ACROSS THE FORECAST AREA. MAX TEMPS WELL INTO THE 70S BUT
WITH UNCERTAINTY IN SCENARIO WILL KEEP POPS IN THE 20-30% RANGE.
SUNDAY...LOW PRESSURE DEVELOPMENT NORTH OF THE REGION SHOULD DRAG
FRONTAL BOUNDARY INTO THE REGION WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS POSSIBLE AREA-WIDE. AGAIN CONFIDENCE/TIMING STILL
LOW/MODERATE AT THIS TIME SO HAVE KEPT POPS AROUND 30% ALTHOUGH HIGH
ENOUGH CONFIDENCE IN WARMER THAN NORMAL TEMPS CONTINUING IN THE 70S.
MONDAY...TRAILING COLD FRONT SHOULD SLOWLY PUSH THROUGH THE FORECAST
AREA AND MAY END UP BEING A DRY DAY WITH LINGERING CLOUDS BUT FOR
NOW HAVE KEPT JUST A SLIGHT CHANCE OF SHOWERS IN THE FORECAST AND
HAVE STAYED CLOSER TO THE SLIGHTLY WARMER MEX GUIDANCE WITH HIGHS
70-75 BUT WILL DEPEND ON FRONTAL TIMING.
&&
.AVIATION...OCNL MVFR VSBY IN SMOKE AT GNV TIL 12Z. OTHERWISE
PREVAILING VFR.
&&
.MARINE...
NO HEADLINES THROUGH THE SHORT TERM AS RIDGE REMAINS NORTH OF THE
WATERS. NEXT INCREASE OF WINDS WILL OCCUR ON FRIDAY IN THE WAKE OF
DEPARTING LOW PRESSURE AND HIGH PRESSURE RIDGE BUILDING IN FROM THE
NORTH WITH NE/E WINDS INCREASING TO 20 KNOTS WITH SEAS AT 5-7 FT
POSSIBLE.
RIP CURRENTS: LOW RISK CONTINUES AS ONSHORE FLOW REMAINS ON THE WEAK
SIDE AND NO SIGNIFICANT SWELLS WITH 2-3 FT BREAKERS POSSIBLE.
&&
.FIRE WEATHER...
BOUNDARY LAYER WILL CONTINUE TO MOISTEN TODAY AND RH VALUES WILL
REMAIN ABOVE CRITICAL LEVELS ACROSS NORTHEAST FLORIDA. MIN RH VALUES
WILL DROP INTO THE 30-35% RANGE ACROSS INLD SE GA...BUT WINDS WILL
REMAIN LESS THAN 10 MPH...SO NO HEADLINES ARE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 72 48 70 53 / 0 10 30 60
SSI 67 55 66 57 / 0 10 20 50
JAX 71 50 72 55 / 0 10 20 50
SGJ 69 54 70 57 / 0 10 10 40
GNV 74 50 73 55 / 0 10 20 40
OCF 77 52 76 57 / 0 10 10 30
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
HESS/PETERSON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
319 AM CST TUE JAN 31 2012
.DISCUSSION...
317 AM CST
THE ATTENTION ON THIS FORECAST WAS PRIMARILY DIRECTED TO
TEMPERATURES...WITH AN EMPHASIS ON TODAY AS NEAR RECORD TO RECORD
WARMTH IS ON PAR AGAIN FOR THE AREA. QUITE A DIFFERENCE FROM ONE
YEAR AGO TODAY...WHICH SAW THE AREA PREPARING FOR THE THIRD
LARGEST SNOWSTORM ON RECORD. AN ADDITIONAL CHALLENGE IN THE
FORECAST IS THAT BOTH WEDNESDAY AND THURSDAY ALSO ARE APPEARING
LIKELY TO BE WARMER THAN INITIALLY THOUGHT.
TEMPERATURES ARE STARTING NEARLY 30 DEGREES ABOVE NORMAL THIS
FINAL DAY OF JANUARY...WHICH IS FITTING FOR THIS MONTH THAT IS
AVERAGING 5 TO 6 DEGREES ABOVE NORMAL. SOUTHERLY WINDS AND
INCREASING LOW-LEVEL MOISTURE THROUGHOUT LAST NIGHT INTO THIS
MORNING HAVE AIDED THESE MILD READINGS. THE ANTICIPATED
STRATUS/STRATOCU IS DEVELOPING QUICKLY NORTHEAST FROM THE SOUTHERN
PLAINS/OZARKS EARLY THIS MORNING...LINING UP WELL WITH MODEL
DIAGNOSTIC SOLUTIONS OF MOISTURE TRANSPORT AND CONVERGENCE IN THE
LOW LEVELS /ROUGHLY 850-925MB/.
EVEN AHEAD OF THESE LOW CLOUDS...MODEL GUIDANCE CONTINUES TO SHOW
BOTH A TOO MOIST AND COOL BIAS IN THE LOW-LEVELS...SOME LIKELY DUE
TO FALSE SNOW COVER AND/OR TOO COLD OF GROUND COVER. JUST THE
31.00 GFS AND NAMELY THE NAM SOUNDINGS ACROSS THE AREA REVEALED
THIS BIAS ALMOST IMMEDIATELY AFTER THEIR INITIALIZATION HOURS. SO
HAVE GUIDED MORE ON ABSOLUTE MOISTURE VALUES AND SATURATION NEAR
THE TOP OF THE ADAPTED MIXED-LAYER LATER THIS MORNING /~4000 FT/
FOR CLOUD INDICATIONS. THE MOISTURE CONVERGENCE FORECAST FROM THE
RUC AND NAM LINE UP WELL FROM SOUTHEAST IA INTO NORTHERN IL AND
EXPECT THE CLOUDS TO EXPAND INTO THAT AREA DURING THE LATE
MORNING. RUC PARCEL TRAJECTORIES WOULD INDICATE NEAR A 12 PM
ARRIVAL IN CHICAGO BASED ON CURRENT PLACEMENT OF THE LOW
CLOUDS...BUT SOME LEAD SATURATION MAY CAUSE IT TO BE A LITTLE
QUICKER. THE STRATUS PLUME AND HOW QUICKLY IT MOVES IN WILL LIKELY
IMPACT TEMPERATURES A FEW DEGREES.
AS FOR THOSE TEMPERATURES TODAY...LOCAL ANALYSIS HERE HAS SHOWN
THAT BIAS-CORRECTED GUIDANCE IS WORKING VERY WELL IN THESE VERY
MILD STRETCHES THIS WINTER...PARTICULARLY THE GEM AND THE EC. HAVE
BLENDED OUR GOING FORECAST HEAVILY TOWARDS THESE SOLUTIONS...AND
EVEN ADJUSTED UP FROM THERE IN SOME AREAS. WHILE THE CLOUDS WILL
EXPAND IN...CONTINUED LOW-LEVEL WARM ADVECTION WILL LIKELY
SUPPORT INCREASING SURFACE TEMPERATURES INTO THE
AFTERNOON...ALBEIT AT A SLOWER RATE. SO HAVE SOME QUICK MORNING
WARMING FORECAST FROM THE HIGH STARTING POINT VALUES...AND THEN
GRADUAL INCREASE THIS AFTERNOON. THIS APPROACH YIELDS REMARKABLY
MILD UPPER 50S TO LOWER 60 DEGREE READINGS BEING LIKELY IN SEVERAL
AREAS. EVEN MID 60S COULD BE TOUCHED IN THE EASTERN HALF OF THE
AREA IF THE RATE OF WARMING AFTER THE CLOUDS ARRIVE IS HIGHER THAN
INDICATED. PLEASE SEE THE CLIMATE SECTION BELOW FOR RECORD
INFORMATION.
AS FOR PRECIPITATION CHANCES THIS AFTERNOON INTO TONIGHT...THE
DEPTH OF THE CLOUDS INCREASE QUICKLY LATE THIS AFTERNOON INTO THE
EVENING. MARGINAL SATURATED ISENTROPIC ASCENT AND CONVERGENCE
AHEAD OF A COLD FRONT MOVING THROUGH...MAY OFFER SPORADIC LIGHT
RAIN OR DRIZZLE IN THE SOUTHEAST HALF OF THE FORECAST AREA DURING
THE LATE AFTERNOON AND EVENING. THE LIGHT RAIN MAY ACTUALLY BE
MORE SHOWERY...BUT LIMITED FORCING WILL PREVENT ANYTHING
APPRECIABLE.
WEDNESDAY AND THURSDAY...WHILE LOW-LEVEL TEMPERATURES ARE FORECAST
TO COOL DURING THIS PERIOD...THEY ARE STILL ON THE WARMER THAN
NORMAL SIDE. THE LACK OF SNOW COVER TOO SHOULD AID IN THE WARMER
BIAS-CORRECTED GUIDANCE BEING MORE ON TRACK. CLOUDS ALSO LOOK
LIMITED...ALTHOUGH CONFIDENCE IS CURRENTLY LOW ON WEDNESDAY
MORNING WITH A SOMEWHAT LIMITED SURGE BEHIND THIS FRONT MEANING
LINGERING STRATUS IS POSSIBLE. IF NOT THOUGH...TEMPERATURES
GETTING TO 50 ON WEDNESDAY SEEM PROBABLE...AND THEN WELL INTO THE
40S ON THURSDAY. RIDGING SHOULD ALLOW FOR ONLY CIRRUS BY THURSDAY.
LATE THIS WEEK INTO THE WEEKEND...THE PROGRESSIVE WESTERLY PATTERN
IS EXPECTED TO SLOW DOWN WITH A CUT OFF LOW AND A GENERAL BLOCKING
PATTERN DEVELOPING TO OUR WEST. DETAILS HAVE VARIED
SIGNIFICANTLY...BUT A CLEAR TREND IN THE GUIDANCE IS SLOWER WITH
PROGRESSING FORCING FOR PRECIPITATION EAST INTO OUR AREA. GIVEN
THAT PATTERN...THAT SEEMS REASONABLE AND HAVE ADJUSTED THE BLENDED
GUIDANCE FORECAST THAT WAY. THE SLOWER 31.00 EC WAS FOLLOWED
CLOSELY FOR DETAILS. SOME FORM OF INVERTED TROUGH OR WEAK SURFACE
LOW IS LIKELY TO DEVELOP AS THE CLOSED UPPER CIRCULATION WORKS
EAST...AND SUCH A FEATURE WOULD ALSO NOT FAVOR PRECIP FAR TO ITS
EAST. SO ONLY HAVE SMALL CHANCES DURING THE WEEKEND...WITH
FORECAST SOUNDINGS AND GENERAL THICKNESSES SLIGHTLY MORE
SUPPORTIVE OF RAIN THAN SNOW IF PRECIP OCCURS. IT IS STILL
FAVORED THAT NO PRECIPITATION WILL OCCUR THIS WEEKEND...ESPECIALLY
IF THE EC SOUTHERN TRACK OF THE CLOSED LOW WERE TO COME TO
FRUITION.
&&
.CLIMATE...
THE RECORD HIGH TODAY FOR CHICAGO IS 65 IN 1989. THE HIGH
TEMPERATURE IS MOST LIKELY TO BE 3 TO 7 DEGREES SHY OF THIS...BUT
IT COULD END UP GETTING VERY CLOSE. THE GOING FORECAST IS FOR THIS
TO BE THE WARMEST DAY THIS METEOROLOGICAL WINTER SO FAR. THIS WILL
BE THE TENTH DAY IN AT LEAST THE 50S SINCE DECEMBER 1ST /BASICALLY
ONE DAY A WEEK THIS WINTER SO FAR/. AS FOR ROCKFORD THE RECORD
HIGH IS 63 ALSO IN 1989. THE HIGH TEMPERATURE IS EXPECTED TO FALL
SEVERAL DEGREES SHORT...BUT CONFIDENCE IS LOWER AT ROCKFORD
DEPENDING ON HOW THE STRATUS EVOLVES IN /IT MAY REMAIN SOUTH OF
ROCKFORD/. THIS WILL BE THE NINTH DAY IN AT LEAST THE 50S THIS
METEOROLOGICAL WINTER AT ROCKFORD.
MTF
&&
.CLIMATE...
RECORD HIGHS FOR JANUARY 30...
* CHICAGO....55 SET IN 1988
* ROCKFORD...52 TIED IN 1944 AND 1926
RECORD HIGHS FOR JANUARY 31...
* CHICAGO....65 SET IN 1989
* ROCKFORD...63 SET IN 1989 /ALSO THE HIGHEST JANUARY RECORDED/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* LLWS THROUGH EARLY MORNING
* GUSTY SSW WINDS MID MORNING THROUGH AFTERNOON
* MVFR CIGS PROBABLE TUESDAY AFTERNOON
SHEA
//DISCUSSION...UPDATED 06Z...
LLWS REMAINS LIKELY THROUGH EARLY TUES MORNING AS STRONG LOW LEVEL
JET PERSISTS ABOVE NOCTURNAL INVERSION RIGHT OFF THE DECK. RECENT
ACARS SOUNDINGS OUT OF ORD SHOW 55KT+ WINDS WITHIN 1500 FT AGL NOW
SO HAVE BUMPED UP THE MAGNITUDE OF THE LLWS IN THE TAFS. BY MID
MORNING TUESDAY THREAT OF LLWS SHOULD SUBSIDE AND TRANSITION MORE
TO LOW LEVEL TURBULENCE AS SURFACE WARMS AND MIXING BEGINS TO
TRANSPORT SOME OF THAT HIGHER MOMENTUM AIR TO THE SURFACE IN
GUSTS. EXPECT SSW WINDS TO GUST TO AT LEAST 25KT BY MID-LATE
MORNING...THOUGH COULD SEE GUSTS BEGIN TO WANE A BIT DURING THE
AFTERNOON IF STRATUS DECK MOVES IN.
SPEAKING OF STRATUS...MODELS REMAIN OBLIVIOUS TO WHAT BOUNDARY
LAYER CONDITIONS ARE ACTUALLY LIKE AND CONTINUE TO UNREALISTICALLY
COOL AND SATURATE THE BOUNDARY LAYER MAKING FORECAST SOUNDINGS
USELESS. SATELLITE IMAGERY DOES SHOW LOW LEVEL MOISTURE AND
STRATUS OVER ARKLATEX REGION BEGINNING TO DEVELOP AND ADVECT
NORTHWARD. ANTICIPATE THIS TREND TO CONTINUE AND PROBABLY
ACCELERATE A BIT OVERNIGHT AS LOW LEVEL JET PULLS THE MOISTURE
NORTHWARD. BASED ON OBS WELL UPSTREAM AND EXPECTATION OF VERY WARM
CONDITIONS WOULD ANTICIPATE BASES OF ANY STRATUS OR STRATOCUMULUS
DECK TO BE MORE IN THE HIGHER END MVFR/LOW END VFR RANGE. GIVEN
THE TRAJECTORY OF THE LOW LEVEL FLOW ITS POSSIBLE THAT THE BRUNT
OF THE NORTHWARD SURGING STRATUS COULD END UP MISSING CHICAGO JUST
TO THE SOUTHEAST...BUT WITH SO MUCH UNCERTAINTY HAVE MAINTAIN IDEA
OF PREVIOUS TAFS WITH MVFR CIGS TUES AFTERNOON.
WINDS SHIFT TO MORE WESTERLY DIRECTION WITH DRIER AIR MOVING IN
AND ANY STRATUS THAT DOES DEVELOP WOULD MOST LIKELY BE SHOVED EAST
IN THE WAKE OF THE WEAK FRONTAL PASSAGE TUESDAY EVENING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* LOW CONFIDENCE ON CIG TRENDS
* LOW CONFIDENCE ON ANY -DZ LATE AFTERNOON
* HIGH CONFIDENCE ALL OTHER FORECAST ELEMENTS
SHEA
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...MVFR CIGS POSSIBLE EARLY.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...SLIGHT CHANCE OF RAIN OR SNOW.
IZZI
&&
.MARINE...
253 AM...LOW PRESSURE OVER THE UPPER MIDWEST WILL MOVE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND INTO QUEBEC WEDNESDAY MORNING.
A WARM FRONT EXTENDING ACROSS NORTH CENTRAL LAKE MICHIGAN THIS
MORNING WILL LIFT NORTH AS THE LOW APPROACHES AND THE GRADIENT
WILL ALSO CONTINUE TO TIGHTEN...FROM SOUTH TO NORTH AS THE LOW
APPROACHES. SOUTHERLY WINDS CONTINUE TO GUST AS HIGH AS 30 KTS
ACROSS FAR SOUTHERN LAKE MICHIGAN EARLY THIS MORNING AND EXPECT
THESE HIGHER WINDS/GUSTS TO CONTINUE NORTH DURING THE DAY. COULD
BE SOME HIGHER GUSTS TO 35 KT GALES BUT RATHER LOW CONFIDENCE
REGARDING HOW PREVAILING THESE MAY BECOME AND WILL NEED TO BE
MONITORED THROUGH THE MORNING.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS THE LAKE
EARLY THIS EVENING... SHIFTING WINDS WESTERLY WITH 30 KTS
POSSIBLE BEHIND THE FRONT... ESPECIALLY ACROSS THE NORTH HALF OR
SO OF THE LAKE. BROAD HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
TONIGHT INTO WEDNESDAY AND THEN ACROSS THE SOUTHERN GREAT LAKES
REGION WEDNESDAY AFTERNOON INTO THURSDAY. NEW LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS THURSDAY NIGHT INTO
FRIDAY AND THEN MOVE NORTHEAST ACROSS THE SOUTHERN LAKES THIS
WEEKEND. WHILE WINDS WILL SHIFT TO THE NORTHEAST AS THIS LOW
APPROACHES...THERE STILL REMAINS QUITE A BIT OF UNCERTAINTY
REGARDING THE TRACK...STRENGTHEN AND TIMING OF THIS SYSTEM. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
459 AM EST TUE JAN 31 2012
.SHORT TERM...
TODAY THROUGH WEDNESDAY NIGHT. FEW CHNGS REQRD WITH AM ISSUANCE.
PREFERENCE LIES TOWARD NAM/HRRR IN SHORT TERM WITH BETTER LOW LEVEL
RESOLUTION. CWA FIRMLY IN WARM SECTOR TODAY AND WITH SIG WARMER
START AND AT LEAST AM INSOLATION SHOULD AFFORD TEMPS CLOSE TO HIR
NAM GUID/HRRR 2M VALUES...AND IN LINE WITH RESPONSE SEEN YDAY
UPSTREAM. SLIGHT DLAY TO PRECIP ONSET WITH ANTICIPATED SLOWER
FNT/MSTR APPROACH WITH SFC FNTL WAVE CRNTLY ACRS OK/KS. SHALLOW
NATURE OF FNTL CONVERGENCE AXIS AND PREFNTL THETA-E POOL SHOULD
PRECLUDE SIG RAFL AMOUNTS AND CONT WITH HIGH POP/LOW QPF FCST WITH
BEST CHCS ACRS SRN/SERN CWA COINCIDENT WITH TONGUE OF HIR/7-8G/KG
0-0.5KM MIXING RATIOS. SHALLOW NATURE OF FNT/LOW AMPLITUDE POST FNTL
RIDGE OVER CNTL/SRN PLAINS TO PRECLUDE STRONG COOLING INTO WED STILL
WELL ABOVE NORMAL. NEXT UPSTREAM WAVE/WEAK PAC NW ENERGY PER WV
IMAGERY THIS AM TO EJECT EWD THROUGH NRN PLAINS...THOUGH WL MINOR
SUBSTANTIALLY IN RESPONSE TO ARDENT HGHT RISES ACRS EPAC ON DY2
WITH NO SENSIBLE WX ANTICIPATED WED/WED NIGHT.
.&&
.LONG TERM...
THURSDAY THROUGH MONDAY
MASSIVE WESTERN NOAM RIDGE WITH REX BLOCKING TENDENCIES CONTINUES TO
OFFER MIXED DETERMINISTIC MODEL SOLUTIONS IN THE PERIOD...WITH
DIFFICULTY ARISING IN THE WEEKEND PERIOD. HOWEVER...THE 00Z ECMWF
SEEMS TO BE THE MOST REASONABLE SOLUTION OF ALL PER MID LEVEL FLOW
DURING THE WEEKEND TIME FRAME /GIVEN THE CONSENSUS TREND TOWARD
PROGRESSIVE NORTHERN ATLANTIC FLOW/ OFFERING A NE BIAS TO HEIGHT
FALLS OVER THE NE CONUS. HENCE...THIS WOULD SUGGEST A CONTINUED
SPLIT FLOW PATTERN WITH A RETAINED CUT OFF LOW OVER THE CENTRAL
CONUS. WILL TREND THE FORECAST IN THE DIRECTION...WITH VERY LITTLE
CHANGE MADE TO THE PREVIOUS FORECAST.
AS STATED ABOVE...SPLIT FLOW IS EXPECTED THROUGH MOST OF THE
PERIOD...ESP IF REX BLOCKING /AS INDICATED IN THE 00Z ECMWF/ COMES
TO FRUITION. HAVE RETAINED LOW CHANCES FOR RAIN-SNOW IN THE SAT/SUN
PERIOD DUE TO A WEAK LINGERING CONCERN DOWNSTREAM FLOW DOES BECOME
LESS PROGRESSIVE AS ADVERTISED IN THE GEM AND GFS..SUPPORTING
PARTIAL MID LEVEL TROUGH PHASING. EVEN SO...LIKELY WEAK MID LEVEL
FLOW ASSOCIATED WITH THE SOUTHERN STREAM IMPULSE...WITH AMPLE LL
MOISTURE PER AN OPEN GOMEX WOULD SUPPORT A HEAVY CONVECTIVE
INFLUENCE TO THE REFLECTED LL TROUGH...IMPARTING A SOUTHERN BIAS TO
A THE SFC LOW TRACK AS INDICATED IN THE ECMWF AND GEM. HIGHLY
ANOMALOUS HEIGHT PATTERN FOR JANUARY WILL OFFER MUCH ABOVE NORMAL
TEMPS THROUGH MOST OF THE PERIOD...WITH FAIRLY DRY CONDITIONS...ESP
IF REX TYPE RIDGE SHIFTS EAST INTO THE GREAT LAKES AS DEPICTED IN
THE ECMWF AND TO A LESSER EXTENT THE GEM. RETAINED DRY WEATHER IN
THE SUN NIGHT/MON PERIOD...GIVEN CONCERNS ON BLOCKED UPSTREAM
FLOW...WITH A STRONG NORTHER BIAS TO ANY NORTHERN STREAM IMPULSES.
&&
.AVIATION /06 UTC TAFS/...
SLIGHT INCRS IN 2KFT WINDS WITH SIG SPEED AND APPROX 30 DEGREES
VEERING IN LLVLS TO CONTINUE UNTIL MIDDAY MIXOUT OF STOUT SFC BASED
INVERSION. LOW CONFIDENCE ON WRT DEVELOPMENT OF STRATOCU DECK TIMING
AND HGHT AND AS SUCH HAVE FAVORED MORE OPTIMISTIC LOW END VFR DECK
DVLPG MIDDAY...IN REASONABLE AGREEMENT WITH HRRR OUTPUT/FAVORED MOS
CATEGORIES. MSTR POOLING AHEAD OF FNT TO MOVE EWD THRU NRN IN THIS
EVE/ERLY TNGHT PROMPTING REDUCTION INTO FUEL ALT CONDS COINCIDENT
WITH MOST PROBABLE PD OF RAFL.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...MURPHY
LONG TERM...JC
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
103 AM EST TUE JAN 31 2012
.AVIATION /06 UTC TAFS/...
SLIGHT INCRS IN 2KFT WINDS WITH SIG SPEED AND APPROX 30 DEGREES
VEERING IN LLVLS TO CONTINUE UNTIL MIDDAY MIXOUT OF STOUT SFC BASED
INVERSION. LOW CONFIDENCE ON WRT DEVELOPMENT OF STRATOCU DECK TIMING
AND HGHT AND AS SUCH HAVE FAVORED MORE OPTIMISTIC LOW END VFR DECK
DVLPG MIDDAY...IN REASONABLE AGREEMENT WITH HRRR OUTPUT/FAVORED MOS
CATEGEGORIES. MSTR POOLING AHEAD OF FNT TO MOVE EWD THRU NRN IN THIS
EVE/ERLY TNGHT PROMPTING REDUCTION INTO FUEL ALT CONDS COINCIDENT
WITH MOST PROBABLE PD OF RAFL.
&&
.UPDATE...
SOME HIGH CLOUDS TO OVERSPREAD ESPECIALLY SOUTHERN SECTIONS OF THE
FORECAST AREA DURING THE LATE EVENING AND OVERNIGHT HOURS IN
ASSOCIATION WITH A WEAK SHORT WAVE EVIDENT ON WATER VAPOR IMAGERY
THIS EVENING ACROSS NORTHERN MISSOURI. DESPITE PARTLY
CLOUDY/MOSTLY CLEAR SKIES FOR THE OVERNIGHT...DIURNAL SWINGS WILL
BE RATHER MINIMAL AS A TIGHT SFC PRESSURE GRADIENT AND AN
UNSEASONABLY MILD AIR MASS CONTINUE TO AFFECT THE AREA. QUITE A
RANGE OF TEMPERATURE READINGS ACROSS THE AREA AT 01Z WITH THE
WARMEST TEMPS CURRENTLY ACROSS THE NORTHWEST WHERE SFC GRADIENT
REMAINS A BIT STRONGER WITH WIND GUSTS AT KSBN OVER PAST FEW HOURS
STILL UP AROUND 25 TO 30 MPH. JUST MINOR TWEAKS MADE TO HOURLY
TEMPS AND PERHAPS SOME SLIGHT DOWNWARD ADJUSTMENT TO MINS IN SOME
SPOTS BASED ON CURRENT TRENDS. MINS FROM LOWER 40S SOUTHWEST TO
UPPER 30S NORTHEAST STILL APPEAR TO BE REASONABLE GIVEN
ORIENTATION OF LOW LEVEL THERMAL RIDGING. CONTINUED NORTHWARD
PROGRESSION OF THE LOW LEVEL WARM FRONT SHOULD EVENTUALLY ALLOW
GRADIENT TO TIGHTEN IN THE FAR NORTHEAST...AND THUS WILL LIKELY
SEE TEMPS BOTTOM OUT OVER THE NEXT FEW HOURS ACROSS THESE
LOCATIONS BEFORE A STEADY OR SLOWLY RISING TEMP TREND OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 301 PM EST MON JAN 30 2012/
SHORT TERM... / TONIGHT THROUGH TUESDAY NIGHT /
WARM FRONT NOW OVER THE CWA WILL LIFT NWD TOWARDS THE NORTHERN GREAT
LAKES TONIGHT INTO TUESDAY...WITH DEEP SOUTHWESTERLY FLOW SUPPORTING
UNSEASONABLY MILD TEMPS THIS PERIOD. MID LVL CLOUD DECK ASSOCIATED
WITH STRONG 50 KT CROSS ISOBARIC FLOW AND REDUCED CPD`S ON THE 295K
SFC WILL EXIT FROM W TO E LATE THIS AFTERNOON WITH JUST SOME PASSING
CIRRUS FOR MUCH OF TONIGHT. THE MAIN FCST CONCERN THIS PACKAGE
CONTINUES TO REVOLVE AROUND STRATUS/FOG/DRIZZLE POTENTIAL LATER
TONIGHT INTO TUESDAY GIVEN 1000-850 HPA THETA-E RISES OVER A MELTING
SNOW PACK...RESULTING IN BOUNDARY LAYER SATURATION AND A
STRENGTHENING LOW LVL INVERSION. THE NAM CONTINUES TO APPEAR TOO
AGGRESSIVE WITH THIS OCCURRING TONIGHT...ESPECIALLY GIVEN THE FACT
THAT UPSTREAM SFC DEWPOINTS ARE RUNNING A LITTLE LOWER THAN PROGGED
BY THIS MODEL. AS A RESULT FAVOR THE SREF AND GFS SOLUTIONS WITH
STRATUS/DRIZZLE NOT REALLY SETTLING IN UNTIL LATE TUESDAY MORNING OR
AFTERNOON...MAINLY WESTERN/NORTHERN AREAS. IF AND HOW FAST THIS
DEVELOPS WILL HAVE A PROFOUND EFFECT ON HIGH TEMPS TOMORROW. TRENDED
TEMPS THROUGH PERIOD WARMER THAN CLIMO BIASED MOS GUIDANCE GIVEN
RECENT MODEL PERFORMANCE IN WAA REGIMES.
SHORTWAVE TROUGH OVER MONTANA THIS AFTERNOON WILL PROPAGATE EWD
INTO THE NORTHERN GREAT LAKES BY LATE TUESDAY/TUESDAY NIGHT...
FORCING A COLD FRONT THROUGH DURING THIS TIME. LOW LVL THETA-E
PLUME ALONG AND AHEAD OF THIS FEATURE SHOULD ALLOW A BAND OF LIGHT
RAIN/DRIZZLE TO DEVELOP AND WORK THROUGH...BEST CHANCES IN THE
SOUTH AND EAST. RAINFALL AMOUNTS SHOULD BE LIGHT AS STRONGER
MID/UPPER LEVEL ASCENT / PER MODEL Q-VECTOR AND PVA CHARTS /
BYPASSES TO THE NORTH WITH MOISTURE LOOKING RELATIVELY SHALLOW.
CONTINUED WITH POPS ABOVE MOS GUIDANCE WITH A LOW QPF/HIGH POP
EVENT ANTICIPATED.
LONG TERM... / WEDNESDAY THROUGH MONDAY /
EXTREME VOLATILITY CONTS THIS PD W/CERTAIN PATTN CHG IN STORE AND
EXEMPLIFIED BY DIZZING ARRAY OF MODEL SOLUTIONS OF NOAM FLW.
FURTHER...12Z MED RANGE GUIDANCE AS A WHOLE LOOKS DEFICIENT IN
DEPTH OF PLAINS HGT FALLS/TROUGH DEPTH LT WEEK ALTHOUGH 12Z GEFS
MEANS REMAIN SUPPORTIVE OF YDAS 12Z ECMWF/GEM LOOK OF DEEPER SRN
PLAINS CYCLOGENESIS AND THAT RATIONAL REMAINS THE FVRD OPTION
GOING FORWARD. THUS THIS YIELDS NO DETERMINISTIC DETAIL OF NOTE TO
WARRANT SIG SPECIFIC CHGS TO PRIOR GRIDS THIS PD. HOPEFULLY
PLANNED NEPAC RECON FLIGHTS WILL LEAD TO SOME MITIGATION OVER THE
COURSE OF THIS WEEK AS OMINOUS SIGNALS REMAIN W/POTENTIAL SIG FLW
PERTURBATIONS OVR THE CNTRL/ERN US LATE WEEK AS WRN RIDGE/ERN
TROUGH PATTN DVLPS. TELECONNECTIONS WOULD FAVOR DVLPMNT OF SIG
SYNOPTIC WAVE OVR THE SRN PLAINS AND SUBSEQUENT NEWD EJECTION UP
THROUGH THE OH VALLEY.
OTHERWISE MORE CERTAIN WRN RIDGE EXPANSION NWD THROUGH WRN
CANADA/ALASKA PORTENDS A LIKELY ARCTIC INVASION INTO THE CNTRL/ERN
US BY LATE NXT WEEK.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...MURPHY
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
323 AM CST TUE JAN 31 2012
.SYNOPSIS...
DOUBLE BARREL SFC LOW OVER WESTERN MN WITH WARM FRONT EXTENDING THROUGH
CENTRAL WI AND MI... AND WEAK COLD FRONT EXTENDING SWD AND JUST MOVING
INTO WESTERN IA ATTIM. GUSTY S/SW WINDS PRE-FRONTAL PUMPING IN THE
MILD AIR WITH TEMPS AT 08Z RUNNING 15-20 DEGS ABOVE THOSE OF YSTDY AT
THIS TIME FOR MOST AREAS... WITH TEMPS RANGING FROM THE M/U 30S IN THE
NORTH TO THE L50S PORTIONS OF THE SOUTH. THESE VALUES ARE 10-18 DEGS
ABOVE NORMAL HIGHS FOR TDY! SKIES MOSTLY CLEAR ATTIM WITH JUST SOME
HIGH THIN CIRRUS PASSING ACROSS THE NORTH WITH RIGHT ENTRANCE REGION
OF JET FROM GREAT LAKES TO NEW ENGLAND. LOW LEVEL MOISTURE CONTINUES TO
SURGE NWD THROUGH THE SOUTHERN PLAINS ON 50+ KT LOW LEVEL JET WITH
MUCH OF STRATUS WITHIN AND JUST NORTH OF 50 DEG ISODROSOTHERM WHICH IS
NOSING INTO SOUTHEAST KS ATTIM. ..05..
&&
.SHORT TERM...TODAY AND TONIGHT...
CLOUD TRENDS... PCPN CHCS AND HIGH TEMPS MAIN FCST CHALLENGES. MID LEVEL
SHORTWAVE AND ATTENDANT SFC LOW COMPLEX WILL SHIFT INTO THE GREAT
LAKES BY TNGT... AND AS RESULT WILL DRAG WEAK COLD FRONT THROUGH THE
REGION LATE THIS AFTN AND EVE. COMBINATION OF INCREASING LOW LEVEL
MOISTURE AND CONVERGENCE IN 925-850 MB LAYER AHEAD OF FRONT EXPECTED TO
GENERATE LOW CLOUDS THIS AM THROUGH AFTN SOUTHEAST 1/2 TO POSSIBLY 2/3
OF CWA... WITH FEW SPRINKLES OR PATCHY LIGHT RAIN POSSIBLE THIS AFTN
MAINLY S/E OF QUAD CITIES WHERE CONVERGENCE OVERLAPS MOIST AXIS. HIGHS
TDY WILL BE RATHER CHALLENGING AND COMPOUNDED BY POOR MODEL PERFORMANCE
WITH RUC STILL SHOWING 6 INCHES OF SNOW ACROSS THE NORTH... WHILE
NEARLY ALL MODELS OVERDONE WITH NORTHERN EXTENT OF LOW LEVEL RH AT 06Z.
MIXING TO NEAR 925 MB OR A LITTLE DEEPER PER YSTDY WOULD YIELD WIDESPREAD
50S FOR HIGHS TDY. RACE WILL BE EXTENT OF MIXING BEFORE ARRIVAL OF THE
LOW CLOUDS. THOUGHTS ATTIM ARE SOME LOW CLOUDS INTO FAR SOUTH AROUND 12Z
POSSIBLE BUT MOST DVLPMNT BY 15-18Z. WITH TEMPS CURRENTLY IN THE M/U 40S
MOST AREAS EXCEPT FAR NORTH... NOT FAR FROM WARMEST GUIDANCE ALREADY AND
WITH FEW HRS OF SOLAR INSOLATION AND GUSTY SW WINDS HARD NOT SEEING MOST
AREAS GOING ABOVE TO MUCH ABOVE WARMEST GUIDANCE LIKE YSTDY. HI-RES
ECMWF AND GGEM TEMPS VERIFIED BETTER YSTDY AND FOLLOWED MORE CLOSELY TDY
FOR GENERAL RANGE OF L50S TO L60S.
TNGT... SKIES EXPECTED TO GENERALLY BECOMING MOSTLY CLEAR WITH PASSAGE
OF WEAK FRONT AND SFC RIDGE/SUBSIDENCE BUILDING IN. LOWS WIDESPREAD 20S
TO L30S. WILL HAVE TO WATCH N/W SECTIONS WHERE WINDS COULD GO NEAR CALM
FOR SEVERAL HRS LATE AND WITH CLEARING SKIES AND DRIER AIR TEMPS COULD END
UP BEING FEW DEGS COLDER. ..05..
.LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...
DRY CONDITIONS WILL BE SEEN WED/WED NIGHT AS ANOTHER FRONT/BOUNDARY
MOVES THROUGH THE AREA. TEMPERATURES WILL CONTINUE TO AVERAGE ABOVE
NORMAL. HIGH PRESSURE WILL MOVE THROUGH THE AREA THURSDAY AND
THURSDAY NIGHT WHICH WILL CONTINUE THE DRY AND WARMER THAN NORMAL
CONDITIONS.
FRIDAY ON...
MODEL CONSENSUS HAS A FAIRLY SUBSTANTIAL MID LATITUDE CYCLONE
AFFECTING THE MIDWEST FRIDAY THROUGH SUNDAY THAT GENERATES SCHC TO
CHC POPS. HOWEVER...THERE ARE PROBLEMS WITH THIS CONSENSUS.
DPROG/DT OF THE MODELS SHOW THE SYSTEM SLOWING DOWN WHICH MAKES
SENSE GIVEN THE SYSTEM IS CUT OFF FROM THE RESPECTIVE STREAMS.
DPROG/DT ALSO SHOWS THE SFC HIGH FROM THE NORTHERN PLAINS INTO THE
UPPER MIDWEST TRENDING STRONGER WHICH DEVELOPS DEEP AND DRY LOW
LEVEL EASTERLY TO NORTHEAST FLOW ACROSS THE AREA. ADDITIONALLY...
THERE IS NOT AS MUCH PHASING OCCURRING WITH THE RESPECTIVE STREAMS.
ALL OF THIS WOULD POINT TO A SLOWER ARRIVAL OF THE SYSTEM AND THE
POTENTIAL FOR MUCH OF THE AREA REMAINING DRY.
UNFORTUNATELY...THERE CONTINUES TO BE VARIABILITY BETWEEN THE MODELS
AND RUN TO RUN CONTINUITY WITH EACH MODEL. THIS VARIABILITY
INDICATES THERE ARE STILL ISSUES ON HOW MUCH PHASING OF THE
RESPECTIVE ENERGIES WILL TAKE PLACE. THE ENERGY THAT IS PROGGED TO
DEVELOP THE CUT OFF SYSTEM IS STILL OVER THE OCEAN SO UNTIL IT COMES
ONSHORE AND GETS SAMPLED BY THE MORE DENSE LAND NETWORKS I EXPECT
THIS VARIABILITY TO CONTINUE.
SUNDAY NIGHT THROUGH MONDAY THE MODEL CONSENSUS HAS DRY CONDITIONS
WITH A COOL DOWN OCCURRING AS A DEEP TROF DEVELOPS OVER THE EASTERN
CONUS. ..08..
&&
.AVIATION... /ISSUED 1137 PM CST MON JAN 30 2012/
VFR CONDITIONS TO CONTINUE THIS EVENING AND MOST OF OVERNIGHT.
THERE IS SOME STRATUS OVER TEXAS AND OKLAHOMA...WHICH SHOULD
STREAM NORTH ON THE 925-850MB SOUTHWEST FLOW OF 40-50KTS. AT THIS
TIME IT APPEARS THAT THE STRATUS WILL MISS THE TERMINALS TO THE
EAST...BUT IT WILL HAVE TO BE MONITORED FOR TRENDS. SOUTHWEST
WINDS AROUND 10 KTS SHOULD INCREASE TO 10-15KTS DURING THE
MORNING. A COLD FRONT WILL PASS ACROSS THE AREA DURING THE
AFTERNOON HOURS...SWEEPING ALL POTENTIAL FOR STRATUS OFF TO THE
EAST...AND TURNING WINDS TO THE WEST AT 10-15KTS. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1141 PM CST MON JAN 30 2012
...UPDATE TO AVIATION...
.DISCUSSION...
21Z WATER VAPOR IMAGERY SHOWS A SHORTWAVE MOVING ACROSS MT AND ID
AND INTO THE NORTHERN PLAINS. MEANWHILE SURFACE OBS SHOW A BROAD
TROUGH OF LOW PRESSURE FROM THE SOUTHERN HIGH PLAINS INTO THE
NORTHERN PLAINS. THIS HAS ALLOWED FOR HIGHS TO WARM INTO THE MID
AND UPPER 60S WHILE DEWPOINTS INCREASED INTO THE 30S ACROSS THE
FORECAST AREA.
FOR TONIGHT AND TUESDAY...THE MAIN CONCERN IS WHAT THE STRONG
MOISTURE ADVECTION WILL DO OVERNIGHT AND EARLY TUESDAY MORNING.
MODELS ARE KEEPING THE FORCING FROM THE NORTHERN PLAINS SHORTWAVE TO
THE NORTH OF THE FORECAST AREA...AND A DECENT ELEVATED MIXED LAYER
IS PROGGED TO KEEP THE BOUNDARY LAYER CAPPED. THEREFORE CHANCES FOR
MEASURABLE PRECIP LOOK PRETTY SLIM AS A COLD FRONT ASSOCIATED WITH
THE NORTHERN PLAINS WAVE PUSHES THROUGH THE AREA DURING THE DAY
TUESDAY. HOWEVER LOW LEVEL MOISTURE IS EXPECTED TO CONTINUE TO
ADVECT NORTH INTO EASTERN KS THROUGH THE NIGHT WITH READINGS
POSSIBLY IN THE MID 40S BY SUNRISE. THE LATEST RUC AND NAM FORECAST
SOUNDINGS CONTINUE TO SHOW THE BOUNDARY LAYER SATURATING BY 12Z
AHEAD OF THE SFC COLD FRONT. THERE ALSO APPEARS TO BE SOME WEAK LIFT
ON THE 285K ISENTROPIC SFC AHEAD OF THE FRONT. THEREFORE DID NOT SEE
ANY REASON TO CHANGE THE MENTION OF FOG AND DRIZZLE FROM THE
PREVIOUS FORECAST. WINDS SHOULD STAY UP FAVORING MORE STRATUS THAN
FOG SO DO NOT ANTICIPATE THERE BEING A SEVERE RESTRICTION TO
VISIBILITIES AT THIS TIME. OVERNIGHT LOWS WILL BE MILD DUE TO THE
WARM AIR AND MOISTURE MOVING NORTH. FOR HIGHS TUESDAY...THE MODELS
ARE MIXING THE BOUNDARY LAYER TO AT LEAST 900 MB WITH NOT A WHOLE
LOT OF COLD AIR BEHIND THE FRONT. BECAUSE OF THIS...HAVE BUMPED HIGHS
UP INTO THE UPPER 50S AND AROUND 60 THINKING THERE SHOULD BE ENOUGH
INSOLATION IN THE AFTERNOON TO HELP TEMPS WARM.
WOLTERS
FOR TUESDAY NIGHT THROUGH THURSDAY...MID AND HIGH LEVEL CLOUDS COULD
BE RATHER PERSISTENT...WITH A BRIEF BREAK LATE WEDNESDAY...WITH MID
AND LOW LEVELS STILL ON THE DRY SIDE BEHIND THE COLD FRONT. AS
MENTIONED ABOVE...AIRMASS COMING IN BEHIND IS ONLY SLIGHTLY COOLER
THAN TUESDAY...BUT MIXING WILL BE MORE LIMITED FOR WEDNESDAY SO
EXPECT SOMEWHAT COOLER TEMPS. FAVORING THE MORE-AGREED-UPON SLOWER
MODELS OVER THE NAM FOR THURSDAY...WITH WEAK MID LEVEL WARM AIR
ADVECTION BRINGING IN DEEPENING HIGH CLOUDS THURSDAY AFTERNOON AS
THE WESTERN UPPER TROF DIGS INTO THE ROCKIES. TEMPS IN THE LOW TO
MID 50S STILL EXPECTED UNDER EASTERLY WINDS.
MEDIUM RANGE MODELS CONTINUE TO COME TOGETHER WITH THE UPPER TROF AT
LEAST PARTIALLY CUTTING OFF FROM THE FLOW FOR THE LATE WEEK AND
WEEKEND PERIODS. OF COURSE ANY SPECIFICS ARE FAR FROM CERTAIN...BUT
PRECIPITATION FALLING ON MOST LOCATIONS AT LEAST ONCE IN THIS PERIOD
IS BECOMING A GOOD BET. STILL APPEARS TEMPS MAY BE COLD ENOUGH TO
SUPPORT SOME SNOW...BUT AGAIN MUCH TO BE DETERMINED HERE. OVERALL
TEMPS NOT EXPECTED TO STRAY FAR FROM EARLY FEBRUARY NORMALS.
65
&&
.AVIATION...
SOUTHWEST SURFACE WINDS WILL ADVECT MOISTURE NORTHWARD...CAUSING LOW
STRATUS TO DEVELOP AT THE TAF SITES AROUND 9Z AND LASTING THROUGH
MOST OF TUESDAY MORNING. ATTM...I KEPT LOW END MVFR CEILINGS OF
1,000 TO 1,200 FEET. THERE MAY BE SOME PERIODS OF IFR CEILINGS
BETWEEN 11Z AND 15Z. AFTER 17Z TUE...THE STRATUS SHOULD MIX OUT. A
WEAK COLD FRONT WILL MOVE SOUTHEAST ACROSS THE TAF SITES EARLY TUESDAY
AFTERNOON SWITCHING WINDS FROM THE SOUTHWEST AND WEST TO THE
NORTH. WIND SPEEDS WILL BE UNDER 11 KTS TODAY AT THE TAF SITES.
GARGAN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
937 PM MST MON JAN 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
OVERALL THE FORECAST IS IN GOOD SHAPE. ONLY TWEAKS WERE TO REFLECT
THE BACK EDGE OF THE PRECIPITATION AREA IN THE POP FORECAST. ALSO
PUT IN SOME LOW POTENTIAL FOR FREEZING RAIN AFTER MIDNIGHT ACROSS
THE SOUTHEAST AS TEMPS AT THE SURFACE MAY FALL BELOW FREEZING
BEFORE THE RAIN EXITS.
PREVIOUS DISCUSSION...A WEST TO NORTHWEST FLOW RESIDES OVER THE
AREA WITH A WEAK DISTURBANCE MOVING EAST THROUGH MONTANA TODAY.
RADAR ECHOES OVER THE STATE HAVE BEEN SPOTTY IN THE PAST 12 TO 18
HOURS BUT SOME INCREASES ARE SHOWING UP IN NORTH-CENTRAL MONTANA
AND A BIT INTO THE WESTERN AND CENTRAL ZONES EARLY THIS AFTERNOON.
THESE ECHOES ARE EXPECTED TO INCREASE IN INTENSITY INTO THE LATE
AFTERNOON THEN BEGIN TO DIMINISH THIS EVENING. THE NAM AND GFS
SHOW IT TO HIT MAINLY THE CENTRAL ZONES...AND HAVE INCREASED POPS
ACCORDINGLY. THE HRRR SHOWED IT PRODUCE THE GREATEST QPF OVER THE
SE ZONES THAN THE GFS. HAVE LEANED MORE WITH THE GFS THOUGH BASED
ON RECENT PERFORMANCE. THE NAM HAS BEEN MUCH TOO WET WITH RECENT
SYSTEMS. ALBEIT BRIEF...THE SYSTEM LOOKS INTENSE WITH MOST OF THE
LIFT OCCURRING JUST ABOVE 700 MB AND WHERE TEMPS ARE AROUND -15C
(AND GOOD DENDRITIC GROWTH). PRECIP TYPE LOOKS TRICKY WITH MODEL
NAM SOUNDINGS SHOWING A POSSIBLE MIX WITH SNOW WHILE THE GFS IS
WARMER AND KEEPS THE PRECIP ALL LIQUID.
SYSTEM PASSES OFF TO OUR SOUTHEAST TONIGHT. WITH POSSIBLE WET
ROADWAYS...CLEARING SKIES AND TEMPS DROPPING BELOW FREEZING...ICY
ROADS ARE A GOOD POSSIBILITY. HAVE HIGHLIGHTED THIS IN AN HWO.
AFTERWARDS...IT LOOKS TO REMAIN PARTLY CLOUDY WITH CONTINUED ABOVE
NORMAL TEMPS. WENT ABOVE MAV AND MET GUIDANCE ON TEMPS...CLOSER
TO BIAS CORRECTED NUMBERS. CLOUDS LOOK TO BEGIN INCREASING
WEDNESDAY AFTERNOON WITH THE NEXT SYSTEM COMING IN. JAMBA
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
MORE SPRING-LIKE WEATHER IN THE OFFING. IN THE MIDST OF AN
AMPLIFYING PATTERN...THE LAST IN A SERIES OF SHORTWAVES MOVES SE
ACROSS THE AREA WED NIGHT...WITH SOME SPLITTING MOTION THOUGH. WILL
RAISE POPS TO A SLIGHT CHANCE OF SNOW SHOWERS.
THEN...AN UNUSUALLY STRONG UPPER RIDGE TAKES HOLD OVER THE WESTERN
STATES...THEN CLOSING OFF A CENTER OVER THE NORTHERN ROCKIES TO
THE PACIFIC NW. THIS GIVES SEVERAL DAYS OF DRY AND MAINLY SUNNY
WEATHER...WITH WINDS ON THE LIGHT SIDE. TEMPS LIKELY TO REMAIN
WELL ABOVE NORMAL WITH THICKNESSES OFTEN IN THE 540S DM...BUT 850
MB FORECAST TEMPS AND MODEL SPECTRUM DO SHOW SIGNIFICANT
DIFFERENCES...SEEMING TO INDICATE POSSIBLE STRONG INVERSIONS.
WITHOUT SNOW COVER THOUGH...PREFER TO STAY ON THE WARM SIDE OF
GUIDANCE.
LATE IN THE PERIOD...SIGNS OF THE RIDGE SHARPENING...AND A LITTLE
FARTHER W. THIS MAY ALLOW AN ARCTIC COLD FRONT FROM THE N TO
BRUSH OUR AREA. MUCH MODEL DIFFERENCE ON TIMING...BEING ANYWHERE
FROM SUNDAY TO TUESDAY...AND ON INTENSITY OF THE FRONT AND UPPER
SUPPORT AS WELL. THEREFORE AM STAYING CONSERVATIVE AS IT IS STILL
OUT THERE ON DAYS 6 TO 8. SIMONSEN
PREVIOUS LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... MODELS
CONTINUE TO INDICATE TRANSITION FROM ZONAL PATTERN TO A HIGH
AMPLITUDE BLOCKING PATTERN EARLY IN THE EXTENDED PERIOD. NEW
WRINKLE IS TAKING THE SHORTWAVE DROPPING THROUGH THE GREAT BASIN
WEDNESDAY/WEDNESDAY NIGHT AND DEVELOPING A CLOSED LOW OVER THE
SOUTHWEST STATES. RIDGE STILL EXPECTED OVER THE NORTHERN ROCKIES
BUT WILL GET CLOSED OR PINCHED OFF BY LOW TO THE SOUTH AND TROF IN
THE EAST PACIFIC.
INITIAL PUSH OF WARM AIR INTO THE REGION WITH RIDGE WILL GRADUALLY
MODERATE AS SHORTWAVES PUSH THROUGH THE TOP OF THE RIDGE. OVERALL
STILL EXPECTING WELL ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. EBERT
&&
.AVIATION...
MID LEVEL CEILINGS 4K FT TO 6K FT AGL SPREADING EASTWARD TONIGHT WITH
RAIN SHOWERS DEVELOPING TOWARD N DAKOTA. THESE WILL LIKELY TURN TO SNOW
SHOWERS LATE TONIGHT BEFORE ENDING...WHICH MAY REDUCE VISIBILITY TO
2 TO 4 MILES AND CEILINGS TO 2-3K FT AGL FOR A SHORT TIME. KEEP AN
EYE OUT FOR MVFR TO BORDERLINE IFR CONDITIONS THROUGH THE
OVERNIGHT HOURS. FOR TUESDAY...EXPECT VFR CONDITIONS WITH
SCATTERED TO BROKEN LAYERS ABOVE 8K FT AGL. SIMONSEN/BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1250 AM EST TUE JAN 31 2012
.SYNOPSIS...
A WARM FRONT WILL CROSS THE REGION OVERNIGHT...BRINGING A SHOT OF
LIGHT SNOW. IN THE WAKE OF THIS SYSTEM...MILDER TEMPERATURES WILL
BE WITH US ON TUESDAY AND WEDNESDAY. THE BEST CHANCE OF LIGHT RAIN
DURING THIS TIME FRAME WILL BE TUESDAY NIGHT INTO WEDNESDAY...WHEN
A WEAK COLD FRONT CROSSES CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
10PM UPDATE...FORECAST IS STILL ON TRACK WITH A WARM FRONT MOVING
THROUGH TONIGHT. IT IS CURRENTLY BRINGING SOME LIGHT SNOW SHOWERS
TO THE CWA. THE HRRR AND THE RUC SEEM TO BE HANDLING IT QUITE
WELL. OTHER MODELS ALSO LOOK TO BE IN GOOD AGREEMENT. THIS FRONT
WILL LIFT OUT OVER THE NEXT SEVERAL HOURS, TAKING THE SNOW SHOWERS
WITH IT. HAVE BACKED OF ON POPS BEHIND THE FRONT AS ALL MODELS
HAVE THE PRECIP ENDING IN THE EARLY MORNING HOURS. STILL KEPT IN
SOME LOW POPS FOR AN ISOLATED SHOWER, BUT PROBABLY WONT BE MORE
THEN SOME FLURRIES. LOOKING UPSTREAM, TEMPS ARE ALREADY BEGINNING
TO VERY SLOWLY RISE IN WESTERN PA. THIS SHOULD BE THE OVERALL TREND
TONIGHT BEHIND THE FRONT. THIS WILL ALLOW SOME VERY WARM TEMPS TO
COME IN TOMORROW, AND IF ANY SUN BREAKS OUT, TEMPS COULD BE HIGHER
THAN FORECAST. THIS WILL ALLOW ANY PRECIP THAT DOES FALL TOMORROW
TO CHANGE OVER TO RAIN, MAINLY AFTER DAYBREAK.
4 PM UPDATE... OVERRUNNING/WAA LGT SNOW IS ALREADY ENTERING WRN NY
ATTM. THIS PCPN SHIELD WILL MAKE STEADY EWD PROGRESS THE NEXT FEW
HRS...AND SHOULD ENVELOPE MUCH OF THE FA (EXCEPT PERHAPS THE FAR
SRN ZNS)...BY 00-02Z. THE SUPPORTING AREA OF ISEN LIFT...DUE TO
ITS RAPID MOVEMENT HOWEVER...WILL ALSO EXIT MOST OF THE CWA JUST
ABT AS QUICKLY. THUS...WE`RE LOOKING FOR STEADIER -SN TO TAPER OFF
ACRS THE TWIN TIERS BY 04-07Z...WITH -SN PROBABLY HANGING ON UNTIL
EARLY TUE IN THE FAR N. IN GENERAL...AN INCH OR LESS IS EXPECTED
OVER THE TWIN TIERS...WITH 1-3" ACRS THE NRN FINGER LKS...THE SRN
TUG HILL RGN...AND THE WRN MOHAWK VLY.
TEMPS WILL EXHIBIT A NON-DIURNAL TREND OVERNIGHT...GENERALLY
RISING SLOWLY AFTER ABT 02-03Z. IN FACT...IN SOME OF OUR NORMALLY
MILDER LAKE PLAIN AREAS...TEMPS SHOULD INCH ABV FRZG LATE
TNT...AND A -RA/-SN MIX COULD OCCUR IN THESE LOCALES.
PREV DISC... 1 PM UPDATE... THE LES ADVSY HAS EXPIRED ON
SCHEDULE. LOW- LVL WAA AND BACKING FLOW HAVE TAKEN THEIR
TOLL...AND THE BAND CONTINUES TO LOOK LESS ORGANIZED ATTM.
THE ONLY OTHER CHGS THIS UPDATE WERE MINOR TWEAKS TO EARLY TO MID-
AFTN TEMPS AND OUR MAX TEMP GRID.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
410 PM UPDATE... THE LOW-LVL WARM FRNT SHOULD REMAIN NEARLY
STATIONARY JUST N OF THE FA TUE AND TUE EVE. THE BEST CHC FOR ANY
-RA/-DZ WILL BE UP CLOSER TO THIS BNDRY...ACRS OUR NRN/ERN ZNS.
ELSEWHERE...CONDS SHOULD STAY LARGELY PCPN-FREE.
A MUCH MILDER AMS WILL BUILD IN ON TUE...AND EVEN WITH ABUNDANT
CLD COVER...HIGHS SHOULD REACH WELL INTO THE 40S...AND MAY TOUCH
50 OVER SXNS OF NE PA. IF ANY SUNSHINE WERE TO BREAK
THROUGH...READINGS COULD GET EVEN WARMER (WELL INTO THE 50S)...BUT
THIS WILL PROBABLY BE TOUGH...GIVEN ALL THE LOW-LVL MOIST IN
PLACE.
TUE NGT...AS A FAST MOVG UPPER TROUGH AND WEAK SFC WAVE MOVE ACRS
ONT/QUE...A COLD FRONT WILL CROSS CNY/NE PA FROM NW TO SE. SCTD
-SHRA SHOULD ACCOMPANY THIS SYSTEM...AS IT APPCHS AND PUSHES
THROUGH.
WED AND WED NGT...VERY WEAK CAA WILL ENSUE BEHIND THE
FRNT...LIKELY INSUFFICIENT FOR ANY REAL LAKE RESPONSE. BY THU...A
SRN STREAM SYSTEM IS PROGGED TO TRACK FM THE LWR MS VLY ENEWD INTO
THE SERN STATES. ALTHOUGH THERE IS CERTAINLY MODEL UNCERTAINTY IN
THE POSITIONING/EVOLUTION OF THIS SYSTEM...CURRENT CONSENSUS
SUGGESTS IT WILL STAY PRIMARILY S OF THE FA. FOR NOW...WE BRING IN
A CHANCE OF -RA/-SN...MOSTLY ACRS NE PA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS BEGIN IN DECENT AGREEMENT FOR THE EXTENDED FORECAST PERIOD.
THE GFS AND THE ECMWF, BOTH SHOW A WEAK UPPER LEVEL TROUGH OVER
THE CWA AT 00Z FRIDAY. THEY BOTH THEN SHOW A FLAT UPPER LEVEL
RIDGE BUILDING BY 00Z SAT. MODELS THEN DIVERGE FOR THE WEEKEND.
THE GFS HAS A SFC RIDGE BUILDING, KEEPING THE AREA MOSTLY DRY,
WITH POSSIBLY SOME LAKE EFFECT FLURRIES. THE ECMWF HAS A LOW
PRESSURE SYSTEM SKIMMING BY THE CWA TO THE SOUTH AND GOING OUT TO
SEA. THE ECMWF HAS BEEN BOUNCING SYSTEMS ALL OVER LATELY, WHICH
HAS BROUGHT CONFIDENCE DOWN IN ITS SOLUTIONS, SO HAVE KEPT POPS
BELOW SLIGHT CHANCE FOR NOW.
BY SUNDAY NIGHT, BOTH MODELS HAVE SOME TYPE OF SYSTEM DEVELOPING
AND MOVING NEAR THE AREA. THE GFS HAS A STRONG LOW OVER THE GREAT
LAKES AND RAIN MOVING INTO THE CWA MONDAY NIGHT WITH A CHANGE TO
MIXED AND THEN SNOW, BEHIND A COLD FRONT BY MONDAY AFTERNOON. THE
ECMWF HAS A WEAK LOW MOVING OF THE COAST OF SOUTHERN NJ AND THEN
OUT TO SEA. IT BRINGS SOME LIGHT SNOW TO THE AREA. HAVE CHC POPS
FOR SUNDAY NIGHT AND DROP TO SLIGHT CHC FOR MOST OF THE CWA
MONDAY, WITH A MIX OF SNOW/RAIN AS THE PTYPE.
HIGH TEMPS FOR THE WEEKEND AND BEGINNING OF THE WEEK LOOK TO BE
ABOVE NORMAL, REACHING INTO THE MID TO UPPER 30S, TO POSSIBLY
AROUND FOR IN NEPA. LOWS EACH NIGHT LOOK TO BE IN THE MID 20S.
SUNDAY NIGHT DOES LOOK AS THOUGH WARM ADVECTION WILL CAUSE A NON
DIURNAL CYCLE, WITH THE LOW HAPPENING IN THE LATE EVENING, EARLY
MORNING HOURS, IF THE GFS IS CORRECT.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
1 AM UPDATE...
THE BACK EDGE OF SNOW IS ALMOST THROUGH KRME...WITH SOME IFR
POSSIBLE HERE FOR ABOUT ANOTHER 30 MINUTES OR SO. OBSERVATIONS
BACK TO THE WEST AT KSYR AND KFZY ARE ALREADY VFR SO EXPECT
IMPROVING CONDITIONS AT KRME TO MOVE IN SOON.
ELSEWHERE VFR CONDITIONS ARE EXPECTED TODAY AS A DECK OF CLOUDS
AROUND 10KFT NOW SLOWLY ERODES TOWARD DAYBREAK ACROSS THE
SOUTHERN 2/3RDS OF THE TERMINALS...AND BY MID-MORNING ACROSS THE
FAR NORTH. SOME MOISTURE MAY TRY TO REFORM EARLY TONIGHT...PERHAPS
EVEN PRODUCING MVFR CIGS LATER TONIGHT...BUT TOO LITTLE CONFIDENCE
TO INCLUDE IN THE TAFS AT THIS MOMENT.
WINDS WILL BE OUT OF THE SOUTH/SOUTHWEST AT 5 TO 10 KTS THROUGH
THE END OF THE TAF PERIOD...EXCEPT LIGHT EAST-SOUTHEAST AT KRME.
.OUTLOOK...
WED...MVFR. OCCASIONAL RAIN SHOWERS.
WED NIGHT...VFR.
THUR...VFR. CHC MVFR SNOW SHOWERS VCNTY KSYR-KRME.
FRI THRU SAT...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...MLJ/SLI
SHORT TERM...MLJ
LONG TERM...SLI
AVIATION...HEDEN
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
136 AM CST TUE JAN 31 2012
.DISCUSSION...
QUICK UPDATE FOR EARLY MORNING GRIDDS (06Z-12Z) TO MENTION MORE
ICE THAN SNOW AS RUC SHOWS WARM 850 MB TEMPS IN THE AREA TIL
12Z...
&&
.PREV DISCUSSION... /ISSUED 848 PM CST MON JAN 30 2012/
DISCUSSION...FORECAST CHALLENGE CONCERNS ONGOING HEADLINES
..ADDITIONAL PCPN AND TEMPERATURES. QUICK SHOT OF LIGHT FREEZING
RAIN JUST PRIOR TO DARK GREASED UP GFK ROADWAYS SO NEEDED TO DROP
ADVISORY SOUTH A SET OF COUNTIES DOWN STREAM IN NW MN. CURRENT
RADAR RETURNS ORIENTED ALONG AND AHEAD OF A WARM FRONT EXTENDING
FROM SURFACE LOW ALONG ND/CANADIAN BORDER NORTH OF MOT THROUGH GFK
TO FSE/BJI. THIS GENERALLY IN AREA OF CURRENT ADVISORY. SOUTH OF
WARM FRONT TEMPERATURES ABOVE FREEZING AND MINIMAL RADAR RETURNS
SO TRAVEL PROBLEMS NOT AS MUCH OF A CONCERN. QUESTION WILL BE IF
WARM FRONT LIFTS ANY FARTHER NORTH. TEMPERATURES CONTINUE SLOWLY
RISE VCNTY OF WARM FRONT WITH GFK APPROACHING 32. NOT MUCH OF A
SURFACE PRESSURE RISE/FALL COUPLET BUT EXPECT LOW TO RIDE ALONG
WARM FRONT SO DO NOT THINK WARMER TEMPERATURES WILL GET MUCH
FARTHER NORTH. WHILE RETURNS WEAKENING WILL CONTINUE WITH ADVISORY
AS SECONDARY BAND OF PCPN ASSOCIATED WITH APPROACHING COLD FRONT
COULD ALSO ARRIVE AS -RA AS COLUMN REMAINS WARM THROUGH 06Z.
COLUMN DOES COOL ALONG MN/CANADIAN BORDER AFT MIDNIGHT SO COULD
STILL SEE SOME MINOR SNOW ACCUMULATIONS ALONG WITH -ZR. THIS
COVERED WELL SO NOT MANY CHANGES NEEDED TO NEXT UPDATE.
AVIATION...CIGS/VSBY WILL CONTINUE IN VFR RANGE OVERNIGHT. COULD
SEE SOME MVFR VSBY LATER TONIGHT IN -SN ALONG INTERNATIONAL BORDER
AREA AS COLUMN COOLS. OTHERWISE ANY ADDITIONAL PCPN PRIOR TO EARLY
AM WILL BE LIKELY LIQUID MAKING FOR SLIPPERY CONDITIONS ACROSS
NORTHERN FORECAST AREA.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
NDZ008-016.
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
MNZ001-004>009-013>017.
&&
$$
RIDDLE/VOELKER
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1057 PM CST MON JAN 30 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM UPDATE...
SHORTWAVE DISTURBANCE MOVING ACROSS THE EASTERN DAKOTAS INTO
CENTRAL MINNESOTA GENERATING SOME SCATTERED VERY LIGHT MIX WEST
OF DLH THIS EVENING. LATEST MODEL GUIDANCE STILL INSISTS THAT BULK
OF MEASURABLE LIGHT PRECIPITATION WILL GENERALLY REMAIN NORTH OF
THE WISCONSIN MICHIGAN BORDER OVERNIGHT. GRB...MPX...DVN AND ILX
SOUNDINGS RATHER DRY AND APPEARS BEST LIFT...ALBEIT WEAK SHOULD
REMAIN NORTH OF THE FORECAST AREA. HOWEVER WILL CONTINUE TO
MONITOR RADAR TRENDS UPSTREAM FOR SMALL PROBABILITY PRECIP CLIPS
FAR NORTHERN COUNTIES.
ELSEWHERE...DID LOWER TEMPS A FEW DEGREES OVERNIGHT AS THIN HIGH
CLOUDS AND LIGHTS WINDS HAVE ALLOWED TEMPS TO FALL INTO THE UPPER
TEENS OVER PARTS OF LINCOLN AND LANGLADE COUNTIES AND INTO THE LOW
TO MID 20S IN PARTS OF THE CENTRAL AND NORTHEAST FORECAST AREA. AS
UPPER SYSTEM CONTINUES TO APPROACH THE FORECAST AREA
OVERNIGHT...EXPECT HIGH-MID CLOUDS TO THICKEN SOME AND TEMPS
SHOULD BECOME STEADY OR PERHAPS RISE AFTER MIDNIGHT.
ESB
.PREV DISCUSSION...ISSUED AT 628 PM CST MON JAN 30 2012...
SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LIGHT SNOW
ASSOCIATED WITH A MID-LEVEL FGEN BAND ALONG AN ELEVATED WARM FRONT
HAS RAPIDLY PUSHED TO THE EAST EARLY THIS AFTERNOON LEAVING
WIDESPREAD MID AND HIGH CLOUDS OVERHEAD. THE SURFACE WARM FRONT IS
STILL LAGGING BEHIND FROM MINNEAPOLIS TO CHICAGO...BUT SE WINDS
NORTH OF THE BOUNDARY HAS BROUGHT WARMER MARINE AIR INTO
NORTHEAST WISCONSIN WHERE TEMPS HAVE REACHED INTO THE MIDDLE 30S.
DESPITE THE WARM ADVECTION...NO SIGN OF ANY STRATUS/DRIZZLE/FOG
DEVELOPMENT UPSTREAM SO FAR...BUT THE ABOVE 30F DEWPOINTS ARE NOW
REACHING INTO EASTERN IOWA AND NORTHERN ILLINOIS. AS WARM ADVECTION
CONTINUES UNABATED AHEAD OF LOW PRESSURE DEVELOPING OVER THE
NORTHERN ROCKIES...LOW STRATUS AND FOG POTENTIAL ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...A SHORTWAVE TROUGH WILL MOVE ACROSS THE DAKOTAS AND PUSH
SURFACE LOW PRESSURE OVER THE NORTHERN MISSISSIPPI VALLEY. AHEAD OF
THE LOW...H850 WARM FRONT WILL LIFT ACROSS THE U.P. INTO
LAKE SUPERIOR. THE THREAT OF PRECIP WILL BE LOCATED ALONG THIS
BOUNDARY AND NORTH OF THE FORECAST AREA...SO HAVE REMOVED POPS FOR
TONIGHT. WILL STILL HAVE PLENTY OF MID AND UPPER MOISTURE AROUND
CARRIED IN BY THE JET STREAM TO MAKE FOR A PARTLY TO MOSTLY CLOUDY
NIGHT. THE BIGGEST FORECAST CHALLENGE TONIGHT WILL BE THE
POSSIBILITY OF FOG OR LOW STRATUS DEVELOPMENT LATE. SSW WILL CARRY
DEWPOINTS IN THE UPPER 20S TO LOWER 30S OVER THE MID-MISSISSIPPI
VALLEY INTO THE REGION TONIGHT. THE NAM IN PARTICULAR IS BULLISH ON
CREATING LOW STRATUS OR FOG BUT COULD BE ONE OF THOSE SCENARIOS
WHERE TEMPS JUST ABOVE THE SURFACE RISE COINCIDENT WITH DEW POINTS
WHICH WOULD CREATE SOME LOWER VSBYS AND FROST DEPOSITS BUT WITHOUT
ANY FOG OR STRATUS. NOT SEEING MUCH POTENTIAL FOR DRIZZLE AS THE
MOISTURE DOESNT APPEAR DEEP ENOUGH. SO WILL PUNT IT OFF TO THE
EVENING CREW UNTIL CAN SEE THE WHITES OF ITS EYES. WITH THE WARM
ADVECTION...LOW TEMPS WILL NOT FALL MUCH...FROM THE MID 20S NORTH TO
LOW 30S SE.
TUESDAY...LOW PRESSURE WILL CONTINUE TO TRACK EAST ALONG THE WARM
FRONT OVER THE U.P. SOUTH OF THE LOW TRACK...GULF MOISTURE WILL
SURGE NORTHEAST BUT LOOKS TO BYPASS THE REGION INTO LOWER MICHIGAN.
AS A RESULT...OUR AIR WILL ARRIVE FROM THE DRIER SOUTHERN GREAT
PLAINS WHICH WILL KEEP THE MID-LEVELS DRY DESPITE A WEAK PACIFIC
COOL FRONT PASSING ACROSS THE AREA IN THE AFTERNOON. AFTER SOME
MORNING MIST OR LOW STRATUS...SHOULD SEE PARTLY TO MOSTLY CLOUDY
SKIES ACROSS THE AREA IN THE AFTERNOON. HIGHS WILL BE WARM AFTER A
MILD START TO THE DAY...WITH HIGHS RANGING FROM THE UPPER 30S NORTH
TO MIDDLE 40S SOUTH.
LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. MILD WEATHER WILL
CONTINUE THROUGH THE REMAINDER OF THE WEEK AND INTO EARLY NEXT
WEEK. CLOUD COVER AND TEMPERATURES ARE THE PRIMARY CHALLENGE
THROUGH SATURDAY AS THERE IS LITTLE CHANCE OF ANY PRECIPITATION.
THE VERY MILD TEMPERATURES AND MELTING SNOW WILL LIKELY PRODUCE
LOW CLOUDS AND FOG AT SOME POINT...ESPECIALLY IN NORTHERN
WISCONSIN WHERE SNOW COVER IS A FOOT OR SO. BUT NOT CERTAIN ENOUGH
ABOUT WHEN THIS MIGHT OCCUR SO DID NOT MENTION ANY FOG IN THE
FORECAST. WE DO EXPECT SOME BY LATER IN THE WEEK.
THE MODELS DO BRING SOME SOUTHERN STREAM JET ENERGY FROM FOUR
CORNERS AREA FRIDAY INTO THE CENTRAL PLAINS SATURDAY AND SUNDAY.
THE EVOLUTION OF THE SYSTEM IS DIFFERENT FROM MODEL TO MODEL AND
RUN TO RUN SO DO NOT HAVE A LOT OF CONFIDENCE AT THIS POINT. THE
GFS SOLUTIONS COULD PRODUCE CONSIDERABLE SNOW OVER WESTERN
WISCONSIN IF IT WOULD VERIFY. THERE IS SOME DECENT AGREEMENT NOW
THAT AN UPPER RIDGE WILL FORM OVER THE WESTERN PART OF NORTH
AMERICA WITH A TROUGH EAST OF ROCKIES. THE MODELS HAVE ADVERTISED
THIS A COUPLE OF TIMES THIS WINTER BUT IT HAS NOT MATERIALIZED.
&&
.AVIATION...
FVR CONDITIONS EXPECTED OVERNIGHT OVER FORECAST AREA AS AIRMASS
AHEAD OF APPROACHING UPPER-LEVEL DISTURBANCE QUITE DRY AND BEST
LARGE-SCALE LIFT WILL BE CONFINED GENERALLY NORTH OF THE
WISCONSIN/MICHIGAN BORDER. EXCEPTION OVERNIGHT WILL BE AROUND IMT
EASTWARD TO LAKE MICHIGAN WHERE SCT MVFR CONDITIONS WILL PERSIST
INTO TUESDAY MORNING. SCATTERED VSBYS OF 3-5 MILES ALSO POSSIBLE
NEAR GRB AND THE FOX VALLEY SOUTHWARD AS LIGHT WINDS...THIN HIGH
CLOUDS AND INCREASING SURFACE DEW POINTS MAY LEAD TO SOME LIGHT FOG.
VFR CONDITIONS CAN BE EXPECTED ON TUESDAY...DESPITE PASSAGE OF
WEAK FRONTAL BOUNDARY ACROSS THE FORECAST AREA LATE INI THE
AFTERNOON. SOME SCATTERED MVFR CONDITIONS POSSIBLE RHI...CWA AND
AUW IMMEDIATELY IN THE WAKE OF FROPA AS WEAK CAA DEVELOPS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
EB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
959 AM CST TUE JAN 31 2012
.DISCUSSION...
317 AM CST
THE ATTENTION ON THIS FORECAST WAS PRIMARILY DIRECTED TO
TEMPERATURES...WITH AN EMPHASIS ON TODAY AS NEAR RECORD TO RECORD
WARMTH IS ON PAR AGAIN FOR THE AREA. QUITE A DIFFERENCE FROM ONE
YEAR AGO TODAY...WHICH SAW THE AREA PREPARING FOR THE THIRD
LARGEST SNOWSTORM ON RECORD. AN ADDITIONAL CHALLENGE IN THE
FORECAST IS THAT BOTH WEDNESDAY AND THURSDAY ALSO ARE APPEARING
LIKELY TO BE WARMER THAN INITIALLY THOUGHT.
TEMPERATURES ARE STARTING NEARLY 30 DEGREES ABOVE NORMAL THIS
FINAL DAY OF JANUARY...WHICH IS FITTING FOR THIS MONTH THAT IS
AVERAGING 5 TO 6 DEGREES ABOVE NORMAL. SOUTHERLY WINDS AND
INCREASING LOW-LEVEL MOISTURE THROUGHOUT LAST NIGHT INTO THIS
MORNING HAVE AIDED THESE MILD READINGS. THE ANTICIPATED
STRATUS/STRATOCU IS DEVELOPING QUICKLY NORTHEAST FROM THE SOUTHERN
PLAINS/OZARKS EARLY THIS MORNING...LINING UP WELL WITH MODEL
DIAGNOSTIC SOLUTIONS OF MOISTURE TRANSPORT AND CONVERGENCE IN THE
LOW LEVELS /ROUGHLY 850-925MB/.
EVEN AHEAD OF THESE LOW CLOUDS...MODEL GUIDANCE CONTINUES TO SHOW
BOTH A TOO MOIST AND COOL BIAS IN THE LOW-LEVELS...SOME LIKELY DUE
TO FALSE SNOW COVER AND/OR TOO COLD OF GROUND COVER. JUST THE
31.00 GFS AND NAMELY THE NAM SOUNDINGS ACROSS THE AREA REVEALED
THIS BIAS ALMOST IMMEDIATELY AFTER THEIR INITIALIZATION HOURS. SO
HAVE GUIDED MORE ON ABSOLUTE MOISTURE VALUES AND SATURATION NEAR
THE TOP OF THE ADAPTED MIXED-LAYER LATER THIS MORNING /~4000 FT/
FOR CLOUD INDICATIONS. THE MOISTURE CONVERGENCE FORECAST FROM THE
RUC AND NAM LINE UP WELL FROM SOUTHEAST IA INTO NORTHERN IL AND
EXPECT THE CLOUDS TO EXPAND INTO THAT AREA DURING THE LATE
MORNING. RUC PARCEL TRAJECTORIES WOULD INDICATE NEAR A 12 PM
ARRIVAL IN CHICAGO BASED ON CURRENT PLACEMENT OF THE LOW
CLOUDS...BUT SOME LEAD SATURATION MAY CAUSE IT TO BE A LITTLE
QUICKER. THE STRATUS PLUME AND HOW QUICKLY IT MOVES IN WILL LIKELY
IMPACT TEMPERATURES A FEW DEGREES.
AS FOR THOSE TEMPERATURES TODAY...LOCAL ANALYSIS HERE HAS SHOWN
THAT BIAS-CORRECTED GUIDANCE IS WORKING VERY WELL IN THESE VERY
MILD STRETCHES THIS WINTER...PARTICULARLY THE GEM AND THE EC. HAVE
BLENDED OUR GOING FORECAST HEAVILY TOWARDS THESE SOLUTIONS...AND
EVEN ADJUSTED UP FROM THERE IN SOME AREAS. WHILE THE CLOUDS WILL
EXPAND IN...CONTINUED LOW-LEVEL WARM ADVECTION WILL LIKELY
SUPPORT INCREASING SURFACE TEMPERATURES INTO THE
AFTERNOON...ALBEIT AT A SLOWER RATE. SO HAVE SOME QUICK MORNING
WARMING FORECAST FROM THE HIGH STARTING POINT VALUES...AND THEN
GRADUAL INCREASE THIS AFTERNOON. THIS APPROACH YIELDS REMARKABLY
MILD UPPER 50S TO LOWER 60 DEGREE READINGS BEING LIKELY IN SEVERAL
AREAS. EVEN MID 60S COULD BE TOUCHED IN THE EASTERN HALF OF THE
AREA IF THE RATE OF WARMING AFTER THE CLOUDS ARRIVE IS HIGHER THAN
INDICATED. PLEASE SEE THE CLIMATE SECTION BELOW FOR RECORD
INFORMATION.
AS FOR PRECIPITATION CHANCES THIS AFTERNOON INTO TONIGHT...THE
DEPTH OF THE CLOUDS INCREASE QUICKLY LATE THIS AFTERNOON INTO THE
EVENING. MARGINAL SATURATED ISENTROPIC ASCENT AND CONVERGENCE
AHEAD OF A COLD FRONT MOVING THROUGH...MAY OFFER SPORADIC LIGHT
RAIN OR DRIZZLE IN THE SOUTHEAST HALF OF THE FORECAST AREA DURING
THE LATE AFTERNOON AND EVENING. THE LIGHT RAIN MAY ACTUALLY BE
MORE SHOWERY...BUT LIMITED FORCING WILL PREVENT ANYTHING
APPRECIABLE.
WEDNESDAY AND THURSDAY...WHILE LOW-LEVEL TEMPERATURES ARE FORECAST
TO COOL DURING THIS PERIOD...THEY ARE STILL ON THE WARMER THAN
NORMAL SIDE. THE LACK OF SNOW COVER TOO SHOULD AID IN THE WARMER
BIAS-CORRECTED GUIDANCE BEING MORE ON TRACK. CLOUDS ALSO LOOK
LIMITED...ALTHOUGH CONFIDENCE IS CURRENTLY LOW ON WEDNESDAY
MORNING WITH A SOMEWHAT LIMITED SURGE BEHIND THIS FRONT MEANING
LINGERING STRATUS IS POSSIBLE. IF NOT THOUGH...TEMPERATURES
GETTING TO 50 ON WEDNESDAY SEEM PROBABLE...AND THEN WELL INTO THE
40S ON THURSDAY. RIDGING SHOULD ALLOW FOR ONLY CIRRUS BY THURSDAY.
LATE THIS WEEK INTO THE WEEKEND...THE PROGRESSIVE WESTERLY PATTERN
IS EXPECTED TO SLOW DOWN WITH A CUT OFF LOW AND A GENERAL BLOCKING
PATTERN DEVELOPING TO OUR WEST. DETAILS HAVE VARIED
SIGNIFICANTLY...BUT A CLEAR TREND IN THE GUIDANCE IS SLOWER WITH
PROGRESSING FORCING FOR PRECIPITATION EAST INTO OUR AREA. GIVEN
THAT PATTERN...THAT SEEMS REASONABLE AND HAVE ADJUSTED THE BLENDED
GUIDANCE FORECAST THAT WAY. THE SLOWER 31.00 EC WAS FOLLOWED
CLOSELY FOR DETAILS. SOME FORM OF INVERTED TROUGH OR WEAK SURFACE
LOW IS LIKELY TO DEVELOP AS THE CLOSED UPPER CIRCULATION WORKS
EAST...AND SUCH A FEATURE WOULD ALSO NOT FAVOR PRECIP FAR TO ITS
EAST. SO ONLY HAVE SMALL CHANCES DURING THE WEEKEND...WITH
FORECAST SOUNDINGS AND GENERAL THICKNESSES SLIGHTLY MORE
SUPPORTIVE OF RAIN THAN SNOW IF PRECIP OCCURS. IT IS STILL
FAVORED THAT NO PRECIPITATION WILL OCCUR THIS WEEKEND...ESPECIALLY
IF THE EC SOUTHERN TRACK OF THE CLOSED LOW WERE TO COME TO
FRUITION.
&&
.CLIMATE...
THE RECORD HIGH TODAY FOR CHICAGO IS 65 IN 1989. THE HIGH
TEMPERATURE IS MOST LIKELY TO BE 3 TO 7 DEGREES SHY OF THIS...BUT
IT COULD END UP GETTING VERY CLOSE. THE GOING FORECAST IS FOR THIS
TO BE THE WARMEST DAY THIS METEOROLOGICAL WINTER SO FAR. THIS WILL
BE THE TENTH DAY IN AT LEAST THE 50S SINCE DECEMBER 1ST /BASICALLY
ONE DAY A WEEK THIS WINTER SO FAR/. AS FOR ROCKFORD THE RECORD
HIGH IS 63 ALSO IN 1989. THE HIGH TEMPERATURE IS EXPECTED TO FALL
SEVERAL DEGREES SHORT...BUT CONFIDENCE IS LOWER AT ROCKFORD
DEPENDING ON HOW THE STRATUS EVOLVES IN /IT MAY REMAIN SOUTH OF
ROCKFORD/. THIS WILL BE THE NINTH DAY IN AT LEAST THE 50S THIS
METEOROLOGICAL WINTER AT ROCKFORD.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SSWLY WINDS GUSTING TO 25KT VEERING SWLY THIS AFTERNOON.
* ANTICIPATED MVFR CIGS THIS AFTERNOON LOOKING LESS LIKELY.
KREIN
//DISCUSSION...UPDATED 12Z...
MORNING FORECAST HAS A FEW CHALLENGES. THE FIRST WILL BE WITH LLWS
LIKELIHOOD THROUGH THE EARLY MORNING HOURS. ORD/MDW 1 MINUTE ASOS
DATA HAS BEEN HAVING ON AND OFF GUSTS IN THE 17-20KT RANGE
OVERNIGHT...WITH SUSTAINED 10-15KT WINDS. 12Z SOUNDINGS FROM ILX
AND DVN MAINTAINED A GENERAL 55KT WIND OUT OF ROUGHLY 240 AT 1.9
KFT. EXPECT THE THREAT TO CONTINUE INTO THROUGH ROUGHLY 15Z OR SO
WHEN HIGHER SURFACE GUSTS BEGIN AND AS THE HIGHEST LOWER LEVEL
WINDS SHIFT EAST. A FRONT WILL MOVE ACROSS THE AIRSPACE LATE THIS
EVENING SHIFTING WINDS FROM WEST TO NORTHWEST.
THE SECOND CHALLENGE WILL BE WITH CLOUD COVER. CONTINUED RUN AFTER
RUN OF ALL FORECAST GUIDANCE HAS BEEN OVERDOING THE LOWEST LEVEL
RH FIELDS...AND BRINGING IN HIGH IFR TO LOW MVFR STRATUS ACROSS
THE EASTERN TERMINALS INTO THE LATE MORNING HOURS. STILL BELIEVE
THAT WE WILL SEE A HIGHER END MVFR TO LOWER END VFR CIG SWING
ACROSS THE REGION BEYOND THE 19Z HOUR TODAY. A MANUAL TIME OF
ARRIVAL OF THE PRESENT FIELD ACROSS NORTHWEST MISSOURI WOULD BRING
THE DECK INTO ORD BY 17Z...AND MET/MAV WOULD LEAD YOU TO BELIEVE
THAT THE TERMINALS WOULD SEE CIGS BELOW 015. DISCOUNTING THAT FOR
A FEW REASONS. FIRST IS DUE TO HIGHER RH BIAS THAT HAS BEEN
ONGOING...AND ALSO FEEL WITH DAYTIME MIXING...CIGS SHOULD BEGIN TO
RAISE. ALSO...H92-95 FLOW WILL TURN A LITTLE MORE WESTERLY THIS
MORNING...AND THE MAIN MOISTURE AXIS SHOULD TURN A LITTLE MORE
EASTERLY. WITH THE BULK OF THE MOISTURE STAYING TO THE SOUTH OF
ORD/MDW...FEEL THAT THE TERMINALS SHOULD NOT SEE ANY -DZ OUTSIDE
OF GYY...WHERE A LATE EVENING TIMING LOOKS BEST AT THIS
POINT...BUT CONFIDENCE REMAINS LOW ENOUGH THAT WILL ONLY CARRY A
PROB30 FOR LIGHT RAIN AT THIS POINT.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MODERATE CONFIDENCE THAT CIGS WILL REMAIN VFR THROUGH EARLY
THIS EVENING UNTIL FROPA...LOWER CONFIDENCE IN CHANCES FOR MVFR
CIGS FOR A SHORT TIME AFTER FROPA.
* LOW CONFIDENCE IN -DZ POTENTIAL IN THE LATE AFTERNOON.
* MODERATE-HIGH CONFIDENCE ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH FRIDAY...VFR
* SATURDAY AND SUNDAY...SLIGHT CHANCE OF RAIN OR SNOW
* MONDAY...VFR
SHEA
&&
.MARINE...
253 AM...LOW PRESSURE OVER THE UPPER MIDWEST WILL MOVE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND INTO QUEBEC WEDNESDAY MORNING.
A WARM FRONT EXTENDING ACROSS NORTH CENTRAL LAKE MICHIGAN THIS
MORNING WILL LIFT NORTH AS THE LOW APPROACHES AND THE GRADIENT
WILL ALSO CONTINUE TO TIGHTEN...FROM SOUTH TO NORTH AS THE LOW
APPROACHES. SOUTHERLY WINDS CONTINUE TO GUST AS HIGH AS 30 KTS
ACROSS FAR SOUTHERN LAKE MICHIGAN EARLY THIS MORNING AND EXPECT
THESE HIGHER WINDS/GUSTS TO CONTINUE NORTH DURING THE DAY. COULD
BE SOME HIGHER GUSTS TO 35 KT GALES BUT RATHER LOW CONFIDENCE
REGARDING HOW PREVAILING THESE MAY BECOME AND WILL NEED TO BE
MONITORED THROUGH THE MORNING.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS THE LAKE
EARLY THIS EVENING... SHIFTING WINDS WESTERLY WITH 30 KTS
POSSIBLE BEHIND THE FRONT... ESPECIALLY ACROSS THE NORTH HALF OR
SO OF THE LAKE. BROAD HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
TONIGHT INTO WEDNESDAY AND THEN ACROSS THE SOUTHERN GREAT LAKES
REGION WEDNESDAY AFTERNOON INTO THURSDAY. NEW LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS THURSDAY NIGHT INTO
FRIDAY AND THEN MOVE NORTHEAST ACROSS THE SOUTHERN LAKES THIS
WEEKEND. WHILE WINDS WILL SHIFT TO THE NORTHEAST AS THIS LOW
APPROACHES...THERE STILL REMAINS QUITE A BIT OF UNCERTAINTY
REGARDING THE TRACK...STRENGTHEN AND TIMING OF THIS SYSTEM. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
823 AM CST TUE JAN 31 2012
.DISCUSSION...
317 AM CST
THE ATTENTION ON THIS FORECAST WAS PRIMARILY DIRECTED TO
TEMPERATURES...WITH AN EMPHASIS ON TODAY AS NEAR RECORD TO RECORD
WARMTH IS ON PAR AGAIN FOR THE AREA. QUITE A DIFFERENCE FROM ONE
YEAR AGO TODAY...WHICH SAW THE AREA PREPARING FOR THE THIRD
LARGEST SNOWSTORM ON RECORD. AN ADDITIONAL CHALLENGE IN THE
FORECAST IS THAT BOTH WEDNESDAY AND THURSDAY ALSO ARE APPEARING
LIKELY TO BE WARMER THAN INITIALLY THOUGHT.
TEMPERATURES ARE STARTING NEARLY 30 DEGREES ABOVE NORMAL THIS
FINAL DAY OF JANUARY...WHICH IS FITTING FOR THIS MONTH THAT IS
AVERAGING 5 TO 6 DEGREES ABOVE NORMAL. SOUTHERLY WINDS AND
INCREASING LOW-LEVEL MOISTURE THROUGHOUT LAST NIGHT INTO THIS
MORNING HAVE AIDED THESE MILD READINGS. THE ANTICIPATED
STRATUS/STRATOCU IS DEVELOPING QUICKLY NORTHEAST FROM THE SOUTHERN
PLAINS/OZARKS EARLY THIS MORNING...LINING UP WELL WITH MODEL
DIAGNOSTIC SOLUTIONS OF MOISTURE TRANSPORT AND CONVERGENCE IN THE
LOW LEVELS /ROUGHLY 850-925MB/.
EVEN AHEAD OF THESE LOW CLOUDS...MODEL GUIDANCE CONTINUES TO SHOW
BOTH A TOO MOIST AND COOL BIAS IN THE LOW-LEVELS...SOME LIKELY DUE
TO FALSE SNOW COVER AND/OR TOO COLD OF GROUND COVER. JUST THE
31.00 GFS AND NAMELY THE NAM SOUNDINGS ACROSS THE AREA REVEALED
THIS BIAS ALMOST IMMEDIATELY AFTER THEIR INITIALIZATION HOURS. SO
HAVE GUIDED MORE ON ABSOLUTE MOISTURE VALUES AND SATURATION NEAR
THE TOP OF THE ADAPTED MIXED-LAYER LATER THIS MORNING /~4000 FT/
FOR CLOUD INDICATIONS. THE MOISTURE CONVERGENCE FORECAST FROM THE
RUC AND NAM LINE UP WELL FROM SOUTHEAST IA INTO NORTHERN IL AND
EXPECT THE CLOUDS TO EXPAND INTO THAT AREA DURING THE LATE
MORNING. RUC PARCEL TRAJECTORIES WOULD INDICATE NEAR A 12 PM
ARRIVAL IN CHICAGO BASED ON CURRENT PLACEMENT OF THE LOW
CLOUDS...BUT SOME LEAD SATURATION MAY CAUSE IT TO BE A LITTLE
QUICKER. THE STRATUS PLUME AND HOW QUICKLY IT MOVES IN WILL LIKELY
IMPACT TEMPERATURES A FEW DEGREES.
AS FOR THOSE TEMPERATURES TODAY...LOCAL ANALYSIS HERE HAS SHOWN
THAT BIAS-CORRECTED GUIDANCE IS WORKING VERY WELL IN THESE VERY
MILD STRETCHES THIS WINTER...PARTICULARLY THE GEM AND THE EC. HAVE
BLENDED OUR GOING FORECAST HEAVILY TOWARDS THESE SOLUTIONS...AND
EVEN ADJUSTED UP FROM THERE IN SOME AREAS. WHILE THE CLOUDS WILL
EXPAND IN...CONTINUED LOW-LEVEL WARM ADVECTION WILL LIKELY
SUPPORT INCREASING SURFACE TEMPERATURES INTO THE
AFTERNOON...ALBEIT AT A SLOWER RATE. SO HAVE SOME QUICK MORNING
WARMING FORECAST FROM THE HIGH STARTING POINT VALUES...AND THEN
GRADUAL INCREASE THIS AFTERNOON. THIS APPROACH YIELDS REMARKABLY
MILD UPPER 50S TO LOWER 60 DEGREE READINGS BEING LIKELY IN SEVERAL
AREAS. EVEN MID 60S COULD BE TOUCHED IN THE EASTERN HALF OF THE
AREA IF THE RATE OF WARMING AFTER THE CLOUDS ARRIVE IS HIGHER THAN
INDICATED. PLEASE SEE THE CLIMATE SECTION BELOW FOR RECORD
INFORMATION.
AS FOR PRECIPITATION CHANCES THIS AFTERNOON INTO TONIGHT...THE
DEPTH OF THE CLOUDS INCREASE QUICKLY LATE THIS AFTERNOON INTO THE
EVENING. MARGINAL SATURATED ISENTROPIC ASCENT AND CONVERGENCE
AHEAD OF A COLD FRONT MOVING THROUGH...MAY OFFER SPORADIC LIGHT
RAIN OR DRIZZLE IN THE SOUTHEAST HALF OF THE FORECAST AREA DURING
THE LATE AFTERNOON AND EVENING. THE LIGHT RAIN MAY ACTUALLY BE
MORE SHOWERY...BUT LIMITED FORCING WILL PREVENT ANYTHING
APPRECIABLE.
WEDNESDAY AND THURSDAY...WHILE LOW-LEVEL TEMPERATURES ARE FORECAST
TO COOL DURING THIS PERIOD...THEY ARE STILL ON THE WARMER THAN
NORMAL SIDE. THE LACK OF SNOW COVER TOO SHOULD AID IN THE WARMER
BIAS-CORRECTED GUIDANCE BEING MORE ON TRACK. CLOUDS ALSO LOOK
LIMITED...ALTHOUGH CONFIDENCE IS CURRENTLY LOW ON WEDNESDAY
MORNING WITH A SOMEWHAT LIMITED SURGE BEHIND THIS FRONT MEANING
LINGERING STRATUS IS POSSIBLE. IF NOT THOUGH...TEMPERATURES
GETTING TO 50 ON WEDNESDAY SEEM PROBABLE...AND THEN WELL INTO THE
40S ON THURSDAY. RIDGING SHOULD ALLOW FOR ONLY CIRRUS BY THURSDAY.
LATE THIS WEEK INTO THE WEEKEND...THE PROGRESSIVE WESTERLY PATTERN
IS EXPECTED TO SLOW DOWN WITH A CUT OFF LOW AND A GENERAL BLOCKING
PATTERN DEVELOPING TO OUR WEST. DETAILS HAVE VARIED
SIGNIFICANTLY...BUT A CLEAR TREND IN THE GUIDANCE IS SLOWER WITH
PROGRESSING FORCING FOR PRECIPITATION EAST INTO OUR AREA. GIVEN
THAT PATTERN...THAT SEEMS REASONABLE AND HAVE ADJUSTED THE BLENDED
GUIDANCE FORECAST THAT WAY. THE SLOWER 31.00 EC WAS FOLLOWED
CLOSELY FOR DETAILS. SOME FORM OF INVERTED TROUGH OR WEAK SURFACE
LOW IS LIKELY TO DEVELOP AS THE CLOSED UPPER CIRCULATION WORKS
EAST...AND SUCH A FEATURE WOULD ALSO NOT FAVOR PRECIP FAR TO ITS
EAST. SO ONLY HAVE SMALL CHANCES DURING THE WEEKEND...WITH
FORECAST SOUNDINGS AND GENERAL THICKNESSES SLIGHTLY MORE
SUPPORTIVE OF RAIN THAN SNOW IF PRECIP OCCURS. IT IS STILL
FAVORED THAT NO PRECIPITATION WILL OCCUR THIS WEEKEND...ESPECIALLY
IF THE EC SOUTHERN TRACK OF THE CLOSED LOW WERE TO COME TO
FRUITION.
&&
.CLIMATE...
THE RECORD HIGH TODAY FOR CHICAGO IS 65 IN 1989. THE HIGH
TEMPERATURE IS MOST LIKELY TO BE 3 TO 7 DEGREES SHY OF THIS...BUT
IT COULD END UP GETTING VERY CLOSE. THE GOING FORECAST IS FOR THIS
TO BE THE WARMEST DAY THIS METEOROLOGICAL WINTER SO FAR. THIS WILL
BE THE TENTH DAY IN AT LEAST THE 50S SINCE DECEMBER 1ST /BASICALLY
ONE DAY A WEEK THIS WINTER SO FAR/. AS FOR ROCKFORD THE RECORD
HIGH IS 63 ALSO IN 1989. THE HIGH TEMPERATURE IS EXPECTED TO FALL
SEVERAL DEGREES SHORT...BUT CONFIDENCE IS LOWER AT ROCKFORD
DEPENDING ON HOW THE STRATUS EVOLVES IN /IT MAY REMAIN SOUTH OF
ROCKFORD/. THIS WILL BE THE NINTH DAY IN AT LEAST THE 50S THIS
METEOROLOGICAL WINTER AT ROCKFORD.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LLWS THROUGH LATE MORNING.
* POSSIBLE MVFR CIGS IN STRATUS BY LATE MORNING/EARLY AFTERNOON.
KREIN
//DISCUSSION...UPDATED 12Z...
MORNING FORECAST HAS A FEW CHALLENGES. THE FIRST WILL BE WITH LLWS
LIKELIHOOD THROUGH THE EARLY MORNING HOURS. ORD/MDW 1 MINUTE ASOS
DATA HAS BEEN HAVING ON AND OFF GUSTS IN THE 17-20KT RANGE
OVERNIGHT...WITH SUSTAINED 10-15KT WINDS. 12Z SOUNDINGS FROM ILX
AND DVN MAINTAINED A GENERAL 55KT WIND OUT OF ROUGHLY 240 AT 1.9
KFT. EXPECT THE THREAT TO CONTINUE INTO THROUGH ROUGHLY 15Z OR SO
WHEN HIGHER SURFACE GUSTS BEGIN AND AS THE HIGHEST LOWER LEVEL
WINDS SHIFT EAST. A FRONT WILL MOVE ACROSS THE AIRSPACE LATE THIS
EVENING SHIFTING WINDS FROM WEST TO NORTHWEST.
THE SECOND CHALLENGE WILL BE WITH CLOUD COVER. CONTINUED RUN AFTER
RUN OF ALL FORECAST GUIDANCE HAS BEEN OVERDOING THE LOWEST LEVEL
RH FIELDS...AND BRINGING IN HIGH IFR TO LOW MVFR STRATUS ACROSS
THE EASTERN TERMINALS INTO THE LATE MORNING HOURS. STILL BELIEVE
THAT WE WILL SEE A HIGHER END MVFR TO LOWER END VFR CIG SWING
ACROSS THE REGION BEYOND THE 19Z HOUR TODAY. A MANUAL TIME OF
ARRIVAL OF THE PRESENT FIELD ACROSS NORTHWEST MISSOURI WOULD BRING
THE DECK INTO ORD BY 17Z...AND MET/MAV WOULD LEAD YOU TO BELIEVE
THAT THE TERMINALS WOULD SEE CIGS BELOW 015. DISCOUNTING THAT FOR
A FEW REASONS. FIRST IS DUE TO HIGHER RH BIAS THAT HAS BEEN
ONGOING...AND ALSO FEEL WITH DAYTIME MIXING...CIGS SHOULD BEGIN TO
RAISE. ALSO...H92-95 FLOW WILL TURN A LITTLE MORE WESTERLY THIS
MORNING...AND THE MAIN MOISTURE AXIS SHOULD TURN A LITTLE MORE
EASTERLY. WITH THE BULK OF THE MOISTURE STAYING TO THE SOUTH OF
ORD/MDW...FEEL THAT THE TERMINALS SHOULD NOT SEE ANY -DZ OUTSIDE
OF GYY...WHERE A LATE EVENING TIMING LOOKS BEST AT THIS
POINT...BUT CONFIDENCE REMAINS LOW ENOUGH THAT WILL ONLY CARRY A
PROB30 FOR LIGHT RAIN AT THIS POINT.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN LLWS FORECAST THROUGH THE MORNING
* MODERATE CONFIDENCE IN CIG TRENDS
* LOW CONFIDENCE IN -DZ POTENTIAL IN THE LATE AFTERNOON
* MODERATE-HIGH CONFIDENCE ALL OTHER FORECAST ELEMENTS
SHEA/KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH FRIDAY...VFR
* SATURDAY AND SUNDAY...SLIGHT CHANCE OF RAIN OR SNOW
* MONDAY...VFR
SHEA
&&
.MARINE...
253 AM...LOW PRESSURE OVER THE UPPER MIDWEST WILL MOVE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND INTO QUEBEC WEDNESDAY MORNING.
A WARM FRONT EXTENDING ACROSS NORTH CENTRAL LAKE MICHIGAN THIS
MORNING WILL LIFT NORTH AS THE LOW APPROACHES AND THE GRADIENT
WILL ALSO CONTINUE TO TIGHTEN...FROM SOUTH TO NORTH AS THE LOW
APPROACHES. SOUTHERLY WINDS CONTINUE TO GUST AS HIGH AS 30 KTS
ACROSS FAR SOUTHERN LAKE MICHIGAN EARLY THIS MORNING AND EXPECT
THESE HIGHER WINDS/GUSTS TO CONTINUE NORTH DURING THE DAY. COULD
BE SOME HIGHER GUSTS TO 35 KT GALES BUT RATHER LOW CONFIDENCE
REGARDING HOW PREVAILING THESE MAY BECOME AND WILL NEED TO BE
MONITORED THROUGH THE MORNING.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS THE LAKE
EARLY THIS EVENING... SHIFTING WINDS WESTERLY WITH 30 KTS
POSSIBLE BEHIND THE FRONT... ESPECIALLY ACROSS THE NORTH HALF OR
SO OF THE LAKE. BROAD HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
TONIGHT INTO WEDNESDAY AND THEN ACROSS THE SOUTHERN GREAT LAKES
REGION WEDNESDAY AFTERNOON INTO THURSDAY. NEW LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS THURSDAY NIGHT INTO
FRIDAY AND THEN MOVE NORTHEAST ACROSS THE SOUTHERN LAKES THIS
WEEKEND. WHILE WINDS WILL SHIFT TO THE NORTHEAST AS THIS LOW
APPROACHES...THERE STILL REMAINS QUITE A BIT OF UNCERTAINTY
REGARDING THE TRACK...STRENGTHEN AND TIMING OF THIS SYSTEM. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
621 AM CST TUE JAN 31 2012
.DISCUSSION...
317 AM CST
THE ATTENTION ON THIS FORECAST WAS PRIMARILY DIRECTED TO
TEMPERATURES...WITH AN EMPHASIS ON TODAY AS NEAR RECORD TO RECORD
WARMTH IS ON PAR AGAIN FOR THE AREA. QUITE A DIFFERENCE FROM ONE
YEAR AGO TODAY...WHICH SAW THE AREA PREPARING FOR THE THIRD
LARGEST SNOWSTORM ON RECORD. AN ADDITIONAL CHALLENGE IN THE
FORECAST IS THAT BOTH WEDNESDAY AND THURSDAY ALSO ARE APPEARING
LIKELY TO BE WARMER THAN INITIALLY THOUGHT.
TEMPERATURES ARE STARTING NEARLY 30 DEGREES ABOVE NORMAL THIS
FINAL DAY OF JANUARY...WHICH IS FITTING FOR THIS MONTH THAT IS
AVERAGING 5 TO 6 DEGREES ABOVE NORMAL. SOUTHERLY WINDS AND
INCREASING LOW-LEVEL MOISTURE THROUGHOUT LAST NIGHT INTO THIS
MORNING HAVE AIDED THESE MILD READINGS. THE ANTICIPATED
STRATUS/STRATOCU IS DEVELOPING QUICKLY NORTHEAST FROM THE SOUTHERN
PLAINS/OZARKS EARLY THIS MORNING...LINING UP WELL WITH MODEL
DIAGNOSTIC SOLUTIONS OF MOISTURE TRANSPORT AND CONVERGENCE IN THE
LOW LEVELS /ROUGHLY 850-925MB/.
EVEN AHEAD OF THESE LOW CLOUDS...MODEL GUIDANCE CONTINUES TO SHOW
BOTH A TOO MOIST AND COOL BIAS IN THE LOW-LEVELS...SOME LIKELY DUE
TO FALSE SNOW COVER AND/OR TOO COLD OF GROUND COVER. JUST THE
31.00 GFS AND NAMELY THE NAM SOUNDINGS ACROSS THE AREA REVEALED
THIS BIAS ALMOST IMMEDIATELY AFTER THEIR INITIALIZATION HOURS. SO
HAVE GUIDED MORE ON ABSOLUTE MOISTURE VALUES AND SATURATION NEAR
THE TOP OF THE ADAPTED MIXED-LAYER LATER THIS MORNING /~4000 FT/
FOR CLOUD INDICATIONS. THE MOISTURE CONVERGENCE FORECAST FROM THE
RUC AND NAM LINE UP WELL FROM SOUTHEAST IA INTO NORTHERN IL AND
EXPECT THE CLOUDS TO EXPAND INTO THAT AREA DURING THE LATE
MORNING. RUC PARCEL TRAJECTORIES WOULD INDICATE NEAR A 12 PM
ARRIVAL IN CHICAGO BASED ON CURRENT PLACEMENT OF THE LOW
CLOUDS...BUT SOME LEAD SATURATION MAY CAUSE IT TO BE A LITTLE
QUICKER. THE STRATUS PLUME AND HOW QUICKLY IT MOVES IN WILL LIKELY
IMPACT TEMPERATURES A FEW DEGREES.
AS FOR THOSE TEMPERATURES TODAY...LOCAL ANALYSIS HERE HAS SHOWN
THAT BIAS-CORRECTED GUIDANCE IS WORKING VERY WELL IN THESE VERY
MILD STRETCHES THIS WINTER...PARTICULARLY THE GEM AND THE EC. HAVE
BLENDED OUR GOING FORECAST HEAVILY TOWARDS THESE SOLUTIONS...AND
EVEN ADJUSTED UP FROM THERE IN SOME AREAS. WHILE THE CLOUDS WILL
EXPAND IN...CONTINUED LOW-LEVEL WARM ADVECTION WILL LIKELY
SUPPORT INCREASING SURFACE TEMPERATURES INTO THE
AFTERNOON...ALBEIT AT A SLOWER RATE. SO HAVE SOME QUICK MORNING
WARMING FORECAST FROM THE HIGH STARTING POINT VALUES...AND THEN
GRADUAL INCREASE THIS AFTERNOON. THIS APPROACH YIELDS REMARKABLY
MILD UPPER 50S TO LOWER 60 DEGREE READINGS BEING LIKELY IN SEVERAL
AREAS. EVEN MID 60S COULD BE TOUCHED IN THE EASTERN HALF OF THE
AREA IF THE RATE OF WARMING AFTER THE CLOUDS ARRIVE IS HIGHER THAN
INDICATED. PLEASE SEE THE CLIMATE SECTION BELOW FOR RECORD
INFORMATION.
AS FOR PRECIPITATION CHANCES THIS AFTERNOON INTO TONIGHT...THE
DEPTH OF THE CLOUDS INCREASE QUICKLY LATE THIS AFTERNOON INTO THE
EVENING. MARGINAL SATURATED ISENTROPIC ASCENT AND CONVERGENCE
AHEAD OF A COLD FRONT MOVING THROUGH...MAY OFFER SPORADIC LIGHT
RAIN OR DRIZZLE IN THE SOUTHEAST HALF OF THE FORECAST AREA DURING
THE LATE AFTERNOON AND EVENING. THE LIGHT RAIN MAY ACTUALLY BE
MORE SHOWERY...BUT LIMITED FORCING WILL PREVENT ANYTHING
APPRECIABLE.
WEDNESDAY AND THURSDAY...WHILE LOW-LEVEL TEMPERATURES ARE FORECAST
TO COOL DURING THIS PERIOD...THEY ARE STILL ON THE WARMER THAN
NORMAL SIDE. THE LACK OF SNOW COVER TOO SHOULD AID IN THE WARMER
BIAS-CORRECTED GUIDANCE BEING MORE ON TRACK. CLOUDS ALSO LOOK
LIMITED...ALTHOUGH CONFIDENCE IS CURRENTLY LOW ON WEDNESDAY
MORNING WITH A SOMEWHAT LIMITED SURGE BEHIND THIS FRONT MEANING
LINGERING STRATUS IS POSSIBLE. IF NOT THOUGH...TEMPERATURES
GETTING TO 50 ON WEDNESDAY SEEM PROBABLE...AND THEN WELL INTO THE
40S ON THURSDAY. RIDGING SHOULD ALLOW FOR ONLY CIRRUS BY THURSDAY.
LATE THIS WEEK INTO THE WEEKEND...THE PROGRESSIVE WESTERLY PATTERN
IS EXPECTED TO SLOW DOWN WITH A CUT OFF LOW AND A GENERAL BLOCKING
PATTERN DEVELOPING TO OUR WEST. DETAILS HAVE VARIED
SIGNIFICANTLY...BUT A CLEAR TREND IN THE GUIDANCE IS SLOWER WITH
PROGRESSING FORCING FOR PRECIPITATION EAST INTO OUR AREA. GIVEN
THAT PATTERN...THAT SEEMS REASONABLE AND HAVE ADJUSTED THE BLENDED
GUIDANCE FORECAST THAT WAY. THE SLOWER 31.00 EC WAS FOLLOWED
CLOSELY FOR DETAILS. SOME FORM OF INVERTED TROUGH OR WEAK SURFACE
LOW IS LIKELY TO DEVELOP AS THE CLOSED UPPER CIRCULATION WORKS
EAST...AND SUCH A FEATURE WOULD ALSO NOT FAVOR PRECIP FAR TO ITS
EAST. SO ONLY HAVE SMALL CHANCES DURING THE WEEKEND...WITH
FORECAST SOUNDINGS AND GENERAL THICKNESSES SLIGHTLY MORE
SUPPORTIVE OF RAIN THAN SNOW IF PRECIP OCCURS. IT IS STILL
FAVORED THAT NO PRECIPITATION WILL OCCUR THIS WEEKEND...ESPECIALLY
IF THE EC SOUTHERN TRACK OF THE CLOSED LOW WERE TO COME TO
FRUITION.
&&
.CLIMATE...
THE RECORD HIGH TODAY FOR CHICAGO IS 65 IN 1989. THE HIGH
TEMPERATURE IS MOST LIKELY TO BE 3 TO 7 DEGREES SHY OF THIS...BUT
IT COULD END UP GETTING VERY CLOSE. THE GOING FORECAST IS FOR THIS
TO BE THE WARMEST DAY THIS METEOROLOGICAL WINTER SO FAR. THIS WILL
BE THE TENTH DAY IN AT LEAST THE 50S SINCE DECEMBER 1ST /BASICALLY
ONE DAY A WEEK THIS WINTER SO FAR/. AS FOR ROCKFORD THE RECORD
HIGH IS 63 ALSO IN 1989. THE HIGH TEMPERATURE IS EXPECTED TO FALL
SEVERAL DEGREES SHORT...BUT CONFIDENCE IS LOWER AT ROCKFORD
DEPENDING ON HOW THE STRATUS EVOLVES IN /IT MAY REMAIN SOUTH OF
ROCKFORD/. THIS WILL BE THE NINTH DAY IN AT LEAST THE 50S THIS
METEOROLOGICAL WINTER AT ROCKFORD.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* MORNING LLWS
* LATE MORNING MVFR STRATUS POTENTIAL
SHEA
//DISCUSSION...UPDATED 12Z...
MORNING FORECAST HAS A FEW CHALLENGES. THE FIRST WILL BE WITH LLWS
LIKELIHOOD THROUGH THE EARLY MORNING HOURS. ORD/MDW 1 MINUTE ASOS
DATA HAS BEEN HAVING ON AND OFF GUSTS IN THE 17-20KT RANGE
OVERNIGHT...WITH SUSTAINED 10-15KT WINDS. 12Z SOUNDINGS FROM ILX
AND DVN MAINTAINED A GENERAL 55KT WIND OUT OF ROUGHLY 240 AT 1.9
KFT. EXPECT THE THREAT TO CONTINUE INTO THROUGH ROUGHLY 15Z OR SO
WHEN HIGHER SURFACE GUSTS BEGIN AND AS THE HIGHEST LOWER LEVEL
WINDS SHIFT EAST. A FRONT WILL MOVE ACROSS THE AIRSPACE LATE THIS
EVENING SHIFTING WINDS FROM WEST TO NORTHWEST.
THE SECOND CHALLENGE WILL BE WITH CLOUD COVER. CONTINUED RUN AFTER
RUN OF ALL FORECAST GUIDANCE HAS BEEN OVERDOING THE LOWEST LEVEL
RH FIELDS...AND BRINGING IN HIGH IFR TO LOW MVFR STRATUS ACROSS
THE EASTERN TERMINALS INTO THE LATE MORNING HOURS. STILL BELIEVE
THAT WE WILL SEE A HIGHER END MVFR TO LOWER END VFR CIG SWING
ACROSS THE REGION BEYOND THE 19Z HOUR TODAY. A MANUAL TIME OF
ARRIVAL OF THE PRESENT FIELD ACROSS NORTHWEST MISSOURI WOULD BRING
THE DECK INTO ORD BY 17Z...AND MET/MAV WOULD LEAD YOU TO BELIEVE
THAT THE TERMINALS WOULD SEE CIGS BELOW 015. DISCOUNTING THAT FOR
A FEW REASONS. FIRST IS DUE TO HIGHER RH BIAS THAT HAS BEEN
ONGOING...AND ALSO FEEL WITH DAYTIME MIXING...CIGS SHOULD BEGIN TO
RAISE. ALSO...H92-95 FLOW WILL TURN A LITTLE MORE WESTERLY THIS
MORNING...AND THE MAIN MOISTURE AXIS SHOULD TURN A LITTLE MORE
EASTERLY. WITH THE BULK OF THE MOISTURE STAYING TO THE SOUTH OF
ORD/MDW...FEEL THAT THE TERMINALS SHOULD NOT SEE ANY -DZ OUTSIDE
OF GYY...WHERE A LATE EVENING TIMING LOOKS BEST AT THIS
POINT...BUT CONFIDENCE REMAINS LOW ENOUGH THAT WILL ONLY CARRY A
PROB30 FOR LIGHT RAIN AT THIS POINT.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN LLWS FORECAST THROUGH THE MORNING
* MODERATE CONFIDENCE IN CIG TRENDS
* LOW CONFIDENCE IN -DZ POTENTIAL IN THE LATE AFTERNOON
* MODERATE-HIGH CONFIDENCE ALL OTHER FORECAST ELEMENTS
SHEA
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH FRIDAY...VFR
* SATURDAY AND SUNDAY...SLIGHT CHANCE OF RAIN OR SNOW
* MONDAY...VFR
SHEA
&&
.MARINE...
253 AM...LOW PRESSURE OVER THE UPPER MIDWEST WILL MOVE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND INTO QUEBEC WEDNESDAY MORNING.
A WARM FRONT EXTENDING ACROSS NORTH CENTRAL LAKE MICHIGAN THIS
MORNING WILL LIFT NORTH AS THE LOW APPROACHES AND THE GRADIENT
WILL ALSO CONTINUE TO TIGHTEN...FROM SOUTH TO NORTH AS THE LOW
APPROACHES. SOUTHERLY WINDS CONTINUE TO GUST AS HIGH AS 30 KTS
ACROSS FAR SOUTHERN LAKE MICHIGAN EARLY THIS MORNING AND EXPECT
THESE HIGHER WINDS/GUSTS TO CONTINUE NORTH DURING THE DAY. COULD
BE SOME HIGHER GUSTS TO 35 KT GALES BUT RATHER LOW CONFIDENCE
REGARDING HOW PREVAILING THESE MAY BECOME AND WILL NEED TO BE
MONITORED THROUGH THE MORNING.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS THE LAKE
EARLY THIS EVENING... SHIFTING WINDS WESTERLY WITH 30 KTS
POSSIBLE BEHIND THE FRONT... ESPECIALLY ACROSS THE NORTH HALF OR
SO OF THE LAKE. BROAD HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
TONIGHT INTO WEDNESDAY AND THEN ACROSS THE SOUTHERN GREAT LAKES
REGION WEDNESDAY AFTERNOON INTO THURSDAY. NEW LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS THURSDAY NIGHT INTO
FRIDAY AND THEN MOVE NORTHEAST ACROSS THE SOUTHERN LAKES THIS
WEEKEND. WHILE WINDS WILL SHIFT TO THE NORTHEAST AS THIS LOW
APPROACHES...THERE STILL REMAINS QUITE A BIT OF UNCERTAINTY
REGARDING THE TRACK...STRENGTHEN AND TIMING OF THIS SYSTEM. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1051 AM EST TUE JAN 31 2012
.UPDATE...
MAIN REASON FOR UPDATE WAS TO INCREASE WIND GUSTS TODAY. FREQUENT
GUSTS ALREADY THIS MORNING IN THE 22-27KT RANGE AND EXPECT THAT TO
CONTINUE AS HEATING/MIXING THIS AFTN WEAKENS SFC BASED INVERSION. ALSO
BUMPED TEMPS UP A BIT BASED ON LATEST OBS/LAV GUIDANCE... BUT
STILL EXPECTING HIGHS IN THE M-U50S ACROSS THE CWA THIS AFTN WHICH
IS BLO FWA/SBN RECORDS IN THE L-M60S.
&&
.PREV DISCUSSION... /ISSUED 645 AM EST TUE JAN 31 2012/
AVIATION /12 UTC TAFS/...
MINOR CHNGS WRT 12 UTC TAFS PER LATEST HRRR AND SAT TRENDS. MVFR
SHOULD ADVECT/DEVLP BY ERLY AFTN INTO NCNTL IN PER INCRSG 1000-850MB
MSTR INCRS. BETTER POOLED MSTR ACRS NERN IN COINCIDENT WITH TIMING
OF SHALLOW FNTL FORCING LATER THIS EVE AS SFC FNT APPROACHES...
SUFFCNT ENOUGH SIGNALS TO INTRO TEMPO IFR AT KFWA ONLY ATTM. DRY
ADVECTION POST FNT SHOULD ALLOW CIGS TO RETURN ABOVE FUEL ALT LATE
IN FCST PD.
SHORT TERM...
TODAY THROUGH WEDNESDAY NIGHT. FEW CHNGS REQRD WITH AM ISSUANCE.
PREFERENCE LIES TOWARD NAM/HRRR IN SHORT TERM WITH BETTER LOW LEVEL
RESOLUTION. CWA FIRMLY IN WARM SECTOR TODAY AND WITH SIG WARMER
START AND AT LEAST AM INSOLATION SHOULD AFFORD TEMPS CLOSE TO HIR
NAM GUID/HRRR 2M VALUES...AND IN LINE WITH RESPONSE SEEN YDAY
UPSTREAM. SLIGHT DLAY TO PRECIP ONSET WITH ANTICIPATED SLOWER
FNT/MSTR APPROACH WITH SFC FNTL WAVE CRNTLY ACRS OK/KS. SHALLOW
NATURE OF FNTL CONVERGENCE AXIS AND PREFNTL THETA-E POOL SHOULD
PRECLUDE SIG RAFL AMOUNTS AND CONT WITH HIGH POP/LOW QPF FCST WITH
BEST CHCS ACRS SRN/SERN CWA COINCIDENT WITH TONGUE OF HIR/7-8G/KG
0-0.5KM MIXING RATIOS. SHALLOW NATURE OF FNT/LOW AMPLITUDE POST FNTL
RIDGE OVER CNTL/SRN PLAINS TO PRECLUDE STRONG COOLING INTO WED STILL
WELL ABOVE NORMAL. NEXT UPSTREAM WAVE/WEAK PAC NW ENERGY PER WV
IMAGERY THIS AM TO EJECT EWD THROUGH NRN PLAINS...THOUGH WL MINOR
SUBSTANTIALLY IN RESPONSE TO ARDENT HGHT RISES ACRS EPAC ON DY2
WITH NO SENSIBLE WX ANTICIPATED WED/WED NIGHT.
&&
LONG TERM...
THURSDAY THROUGH MONDAY
MASSIVE WESTERN NOAM RIDGE WITH REX BLOCKING TENDENCIES CONTINUES TO
OFFER MIXED DETERMINISTIC MODEL SOLUTIONS IN THE PERIOD...WITH
DIFFICULTY ARISING IN THE WEEKEND PERIOD. HOWEVER...THE 00Z ECMWF
SEEMS TO BE THE MOST REASONABLE SOLUTION OF ALL PER MID LEVEL FLOW
DURING THE WEEKEND TIME FRAME /GIVEN THE CONSENSUS TREND TOWARD
PROGRESSIVE NORTHERN ATLANTIC FLOW/ OFFERING A NE BIAS TO HEIGHT
FALLS OVER THE NE CONUS. HENCE...THIS WOULD SUGGEST A CONTINUED
SPLIT FLOW PATTERN WITH A RETAINED CUT OFF LOW OVER THE CENTRAL
CONUS. WILL TREND THE FORECAST IN THE DIRECTION...WITH VERY LITTLE
CHANGE MADE TO THE PREVIOUS FORECAST.
AS STATED ABOVE...SPLIT FLOW IS EXPECTED THROUGH MOST OF THE
PERIOD...ESP IF REX BLOCKING /AS INDICATED IN THE 00Z ECMWF/ COMES
TO FRUITION. HAVE RETAINED LOW CHANCES FOR RAIN-SNOW IN THE SAT/SUN
PERIOD DUE TO A WEAK LINGERING CONCERN DOWNSTREAM FLOW DOES BECOME
LESS PROGRESSIVE AS ADVERTISED IN THE GEM AND GFS..SUPPORTING
PARTIAL MID LEVEL TROUGH PHASING. EVEN SO...LIKELY WEAK MID LEVEL
FLOW ASSOCIATED WITH THE SOUTHERN STREAM IMPULSE...WITH AMPLE LL
MOISTURE PER AN OPEN GOMEX WOULD SUPPORT A HEAVY CONVECTIVE
INFLUENCE TO THE REFLECTED LL TROUGH...IMPARTING A SOUTHERN BIAS TO
A THE SFC LOW TRACK AS INDICATED IN THE ECMWF AND GEM. HIGHLY
ANOMALOUS HEIGHT PATTERN FOR JANUARY WILL OFFER MUCH ABOVE NORMAL
TEMPS THROUGH MOST OF THE PERIOD...WITH FAIRLY DRY CONDITIONS...ESP
IF REX TYPE RIDGE SHIFTS EAST INTO THE GREAT LAKES AS DEPICTED IN
THE ECMWF AND TO A LESSER EXTENT THE GEM. RETAINED DRY WEATHER IN
THE SUN NIGHT/MON PERIOD...GIVEN CONCERNS ON BLOCKED UPSTREAM
FLOW...WITH A STRONG NORTHER BIAS TO ANY NORTHERN STREAM IMPULSES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...MURPHY
LONG TERM...JC
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
554 AM CST TUE JAN 31 2012
.AVIATION...
EARLIER AMENDED TAFS TO ADD LLWS AND HAVE MAINTAINED MENTION THROUGH
MID AM WITH KDVN 12Z RAOB SHOWING STRONG WINDS OF 23048KT AT 1900 FT.
STRATUS WITH GENERALLY MVFR CIGS CONTINUES STREAMING NWD ON 40-50 KT
LOW LEVEL JET... AND IS APPROACHING SOUTHEAST IA ATTIM. EXPECT
THE STRATUS TO CONTINUE MOVING NE AND WILL OVERSPREAD KBRL AND KMLI
TERMINALS BY MID AM... AND PERSIST THROUGH THE AFTN. THE STRATUS
IS SHOWN BY LATEST MODELS TO STAY MOSTLY SOUTH OF KCID AND KDBQ
TERMINALS... AS LOW LEVEL FLOW CONTINUES VEERING TO SW AHEAD OF AN
APPROACHING WEAK COLD FRONT... BUT THIS WILL NEED TO BE MONITORED.
PATCHY LIGHT RAIN AND/OR SPRINKLES WILL BE POSSIBLE THIS AFTN THROUGH
SUNSET ALONG AND ESPECIALLY SE OF KBRL-KMLI. CONFIDENCE TOO LOW
FOR INCLUSION IN 12Z TAFS DUE TO WEAKENING LOW LEVEL CONVERGENCE.
ANY PCPN LIKELY TO BE VERY LIGHT AND NOT CAUSE A REDUCTION IN VSBYS.
AFOREMENTIONED WEAK COLD FRONT TO PASS LATE THIS AFTN AND EARLY THIS
EVE WITH CONDITIONS LIKELY BECOMING VFR WITHIN A FEW HRS OF PASSAGE AS
WINDS SHIFT TO W/NW AOB 10 KTS. WINDS LIKELY TO DROP OFF LATE TNGT WITH
SFC RIDGE SETTLING IN... AND MAY SEE SOME FOG DUE TO RADIATIONAL COOLING
WITH VSBYS 2-6SM.
&&
.PREV DISCUSSION... /ISSUED 323 AM CST TUE JAN 31 2012/
SYNOPSIS...
DOUBLE BARREL SFC LOW OVER WESTERN MN WITH WARM FRONT EXTENDING THROUGH
CENTRAL WI AND MI... AND WEAK COLD FRONT EXTENDING SWD AND JUST MOVING
INTO WESTERN IA ATTIM. GUSTY S/SW WINDS PRE-FRONTAL PUMPING IN THE
MILD AIR WITH TEMPS AT 08Z RUNNING 15-20 DEGS ABOVE THOSE OF YSTDY AT
THIS TIME FOR MOST AREAS... WITH TEMPS RANGING FROM THE M/U 30S IN THE
NORTH TO THE L50S PORTIONS OF THE SOUTH. THESE VALUES ARE 10-18 DEGS
ABOVE NORMAL HIGHS FOR TDY! SKIES MOSTLY CLEAR ATTIM WITH JUST SOME
HIGH THIN CIRRUS PASSING ACROSS THE NORTH WITH RIGHT ENTRANCE REGION
OF JET FROM GREAT LAKES TO NEW ENGLAND. LOW LEVEL MOISTURE CONTINUES TO
SURGE NWD THROUGH THE SOUTHERN PLAINS ON 50+ KT LOW LEVEL JET WITH
MUCH OF STRATUS WITHIN AND JUST NORTH OF 50 DEG ISODROSOTHERM WHICH IS
NOSING INTO SOUTHEAST KS ATTIM. ..05..
SHORT TERM...TODAY AND TONIGHT...
CLOUD TRENDS... PCPN CHCS AND HIGH TEMPS MAIN FCST CHALLENGES. MID LEVEL
SHORTWAVE AND ATTENDANT SFC LOW COMPLEX WILL SHIFT INTO THE GREAT
LAKES BY TNGT... AND AS RESULT WILL DRAG WEAK COLD FRONT THROUGH THE
REGION LATE THIS AFTN AND EVE. COMBINATION OF INCREASING LOW LEVEL
MOISTURE AND CONVERGENCE IN 925-850 MB LAYER AHEAD OF FRONT EXPECTED TO
GENERATE LOW CLOUDS THIS AM THROUGH AFTN SOUTHEAST 1/2 TO POSSIBLY 2/3
OF CWA... WITH FEW SPRINKLES OR PATCHY LIGHT RAIN POSSIBLE THIS AFTN
MAINLY S/E OF QUAD CITIES WHERE CONVERGENCE OVERLAPS MOIST AXIS. HIGHS
TDY WILL BE RATHER CHALLENGING AND COMPOUNDED BY POOR MODEL PERFORMANCE
WITH RUC STILL SHOWING 6 INCHES OF SNOW ACROSS THE NORTH... WHILE
NEARLY ALL MODELS OVERDONE WITH NORTHERN EXTENT OF LOW LEVEL RH AT 06Z.
MIXING TO NEAR 925 MB OR A LITTLE DEEPER PER YSTDY WOULD YIELD WIDESPREAD
50S FOR HIGHS TDY. RACE WILL BE EXTENT OF MIXING BEFORE ARRIVAL OF THE
LOW CLOUDS. THOUGHTS ATTIM ARE SOME LOW CLOUDS INTO FAR SOUTH AROUND 12Z
POSSIBLE BUT MOST DVLPMNT BY 15-18Z. WITH TEMPS CURRENTLY IN THE M/U 40S
MOST AREAS EXCEPT FAR NORTH... NOT FAR FROM WARMEST GUIDANCE ALREADY AND
WITH FEW HRS OF SOLAR INSOLATION AND GUSTY SW WINDS HARD NOT SEEING MOST
AREAS GOING ABOVE TO MUCH ABOVE WARMEST GUIDANCE LIKE YSTDY. HI-RES
ECMWF AND GGEM TEMPS VERIFIED BETTER YSTDY AND FOLLOWED MORE CLOSELY TDY
FOR GENERAL RANGE OF L50S TO L60S.
TNGT... SKIES EXPECTED TO GENERALLY BECOMING MOSTLY CLEAR WITH PASSAGE
OF WEAK FRONT AND SFC RIDGE/SUBSIDENCE BUILDING IN. LOWS WIDESPREAD 20S
TO L30S. WILL HAVE TO WATCH N/W SECTIONS WHERE WINDS COULD GO NEAR CALM
FOR SEVERAL HRS LATE AND WITH CLEARING SKIES AND DRIER AIR TEMPS COULD END
UP BEING FEW DEGS COLDER. ..05..
LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...
DRY CONDITIONS WILL BE SEEN WED/WED NIGHT AS ANOTHER FRONT/BOUNDARY
MOVES THROUGH THE AREA. TEMPERATURES WILL CONTINUE TO AVERAGE ABOVE
NORMAL. HIGH PRESSURE WILL MOVE THROUGH THE AREA THURSDAY AND
THURSDAY NIGHT WHICH WILL CONTINUE THE DRY AND WARMER THAN NORMAL
CONDITIONS.
FRIDAY ON...
MODEL CONSENSUS HAS A FAIRLY SUBSTANTIAL MID LATITUDE CYCLONE
AFFECTING THE MIDWEST FRIDAY THROUGH SUNDAY THAT GENERATES SCHC TO
CHC POPS. HOWEVER...THERE ARE PROBLEMS WITH THIS CONSENSUS.
DPROG/DT OF THE MODELS SHOW THE SYSTEM SLOWING DOWN WHICH MAKES
SENSE GIVEN THE SYSTEM IS CUT OFF FROM THE RESPECTIVE STREAMS.
DPROG/DT ALSO SHOWS THE SFC HIGH FROM THE NORTHERN PLAINS INTO THE
UPPER MIDWEST TRENDING STRONGER WHICH DEVELOPS DEEP AND DRY LOW
LEVEL EASTERLY TO NORTHEAST FLOW ACROSS THE AREA. ADDITIONALLY...
THERE IS NOT AS MUCH PHASING OCCURRING WITH THE RESPECTIVE STREAMS.
ALL OF THIS WOULD POINT TO A SLOWER ARRIVAL OF THE SYSTEM AND THE
POTENTIAL FOR MUCH OF THE AREA REMAINING DRY.
UNFORTUNATELY...THERE CONTINUES TO BE VARIABILITY BETWEEN THE MODELS
AND RUN TO RUN CONTINUITY WITH EACH MODEL. THIS VARIABILITY
INDICATES THERE ARE STILL ISSUES ON HOW MUCH PHASING OF THE
RESPECTIVE ENERGIES WILL TAKE PLACE. THE ENERGY THAT IS PROGGED TO
DEVELOP THE CUT OFF SYSTEM IS STILL OVER THE OCEAN SO UNTIL IT COMES
ONSHORE AND GETS SAMPLED BY THE MORE DENSE LAND NETWORKS I EXPECT
THIS VARIABILITY TO CONTINUE.
SUNDAY NIGHT THROUGH MONDAY THE MODEL CONSENSUS HAS DRY CONDITIONS
WITH A COOL DOWN OCCURRING AS A DEEP TROF DEVELOPS OVER THE EASTERN
CONUS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
655 AM EST TUE JAN 31 2012
UPDATED FOR 12Z AVIATION DISCUSSION
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL FLOW ACROSS THE
NRN CONUS WITH A SHORTWAVE FROM NW MN INTO CNTRL SD. AT THE SFC...A
LOW PRES WAS LOCATED OVER NW MN WITH A WARM FRONT FROM CNTRL MN INTO
SRN WI. RADAR INDICATED PATCHY RETURNS OVER LAKE SUPERIOR AND WRN
UPPER MI SUPPORTED BY ISENTROPIC LIFT NORTH OF THE WARM FRONT.
HOWEVER...LITTLE IF ANY WAS REACHING THE GROUND AS OBS INDICATED
MAINLY JUST MID CLOUDS WITH NO PCPN.
&&
.SHORT TERM...TODAY AND TONIGHT
TODAY...EXPECT THE BEST CHANCE OF MEASURABLE PCPN TO REMAIN NORTH
OF THE CWA THIS MORNING WHERE THE GREATEST LIFT (285-295K LAYER) AND
DEEPER SATURATION OCCURS. OTHERWISE...A SUBSTANTIAL 925-750 MB DRY
LAYER WILL LIMIT ANY CHANCE OF RAIN/SNOW OVER UPPER MI. THERE MAY
STILL BE ENOUGH LOW LEVEL MOISTURE OVER THE NORTH HALF OF THE CWA FOR
SOME PATCHY -FZDZ...ESPECIALLY WHERE SRLY UPSLOPE FLOW PREVAILS. AS
THE SHORTWAVE MOVES THROUGH THIS AFTERNOON A PERIOD OF 700-500 MB
FGEN MAY PRODUCE ADDITIONAL LIFT BUT IS NOT EXPECTED TO BE STRONG
ENOUGH TO OVERCOME THE DRY LAYER BENEATH THE MID CLOUDS. EXPECT CLOUD
COVER TO BE THICK ENOUGH TO LIMIT MAX READINGS TO THE MID AND UPPER
30S DESPITE 900 MB TEMPS TO AROUND 5C.
TONIGHT...CAA IN THE WAKE OF THE SFC LOW DROPPING 850 MB TEMPS TO
NEAR -7C WITH INCREASING WNW WINDS MAY BE ENOUGH TO SUPPORT SOME
LIGHT LAKE ENHANCED PCPN INTO WRN UPPER MI DURING THE EVENING AND
FOR LOCATIONS EAST OF MARQUETTE OVERNIGHT. SINCE TEMPS IN THE CLOUD
LAYER (DOWN TO -7C TO -10C) WILL ONLY BE MARGINAL FOR ICE
CRYSTALS...-FZDZ POTENTIAL WILL CONTINUE.
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE WILL DOMINATE MUCH OF THIS PERIOD...WITH ONLY A
SLIGHT CHANCE OF OFF AND ON PRECIPITATION. WEATHER TYPE WILL REMAIN
TRICKY WITH AFTERNOON HIGH TEMPS IN THE 30S...LOWS MAINLY IN THE
20S...AND LOW LEVEL MOISTURE STUCK BELOW A STRONG INVERSION.
DRIZZLE OR FREEZING DRIZZLE WILL AGAIN BE A CONCERN TO START US OFF
ON WEDNESDAY. WHILE THE BULK OF MOISTURE WILL EXIT WITH THE SFC LOW
OVER FAR SE ONTARIO/S QUEBEC BY 12Z WEDNESDAY...A SFC TROUGH WILL
REMAIN THROUGH THE KEWEENAW PENINSULA/ISLE ROYALE AREA. LINGERING
LOW LEVEL MOISTURE UNDER NW FLOW WILL BE A CONCERN. THIS TROUGH WILL
SLOWLY ERODE WEST TO EAST THROUGH 00Z THURSDAY AS A RIDGE SLIDES IN.
ALTHOUGH LOW LEVEL MOISTURE REMAINS WEDNESDAY NIGHT /WITH THE
SHORTWAVE SLIDING ACROSS THE CWA/...IT DID NOT SEEM LIKE ENOUGH TO
WARRANT THE LOW POPS. ADDED FLURRIES INSTEAD...AFTER MIDNIGHT TO THE
KEWEENAW PENINSULA AND EAST OF MUNISING NEAR LAKE SUPERIOR WHEN SFC
WINDS BECOME MORE WNW.
THURSDAY NIGHT THROUGH MONDAY...
FORECAST MODELS DIVERGE SIGNIFICANTLY TOWARD THE END OF THE WORK
WEEK...PARTICULARLY WITH THE HANDLING OF LOW PRESSURE TO OUR SOUTH.
THE RESULT IS LOWER CONFIDENCE IN THE ONGOING FORECAST FROM FRIDAY
THROUGH MONDAY. THE 30/18Z GFS IS BACKED UP BY THE 30/12Z CANADIAN
AND TO A MUCH LESSER EXTENT THE DGEX. THEY SUPPORT THE SFC LOW
ORGANIZING OUT OF THE 4 CORNERS REGION THURSDAY...SLIDING OVER KS
FRIDAY NIGHT...IA SATURDAY NIGHT...AND SOUTHERN WI BY SUNDAY MORNING.
STRONG HIGH PRESSURE OVER S ONTARIO/QUEBEC AND LAKE SUPERIOR WILL
ACT TO KEEP MAINLY DRY AIR IN PLACE OVER OUR REGION THROUGH AT LEAST
SATURDAY.
WITH ALL THE DIFFERENCES BETWEEN THE ECMWF AND THE OVERALL
CONSENSUS...THEY DO MERGE IN ON HAVING THE SFC LOW JUST SE OF THE
CWA BY 00Z MONDAY...WITH THE GFS BEING MORE PROGRESSIVE THEREAFTER
AS THE SOUTHERN LOW NEARLY MERGES WITH THE NORTHERN STREAM LOW OVER
HUDSON BAY.
JUST HOW MUCH COLD AIR FILTERS IN BEHIND THE LOW IS A QUESTION. THE
30/18Z GFS SUGGESTS 850MB TEMPS WARMING TO AROUND -1C 00Z SUNDAY
PRIOR TO ANY PRECIP...WITH -2 TO -6C AIR NEAR THE LOW ITSELF. THE
COOL NNW FLOW BEHIND THE SYSTEM SUNDAY NIGHT INTO MONDAY BEING LESS
THAN IMPRESSIVE WITH -6C ABOUT THE COLDEST AIR AVAILABLE. THE COLDER
AIR /BELOW -12C LOOKS/ TO REMAIN OVER N MANITOBA/ONTARIO THROUGH
MONDAY. RUN TO RUN CONSISTENCY WITH THE GFS IS ALSO A BIT OF AN
ISSUE...AS THE 12Z GFS DID MERGE WITH THE NORTHERN STREAM A BIT
EARLIER RESULTING IN COLDER AIR OF -12C TO -14C BY MONDAY ACROSS THE
NW COUNTIES.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
ALTHOUGH THE LOW LEVEL MOISTURE/CLOUDS HAVE MOVED OUT EARLY THIS
MORNING...LEAVING MAINLY MID CLOUDS OVER THE AREA...EXPECT MVFR CIGS
MAY REDEVELOP WITH CONTINUED MOIST SRLY FLOW INTO THE AREA. A PAIR
OF COLD FNTS WILL THEN CROSS THE AREA LATER TDAY. THERE WL BE A
RETURN OF MVFR CIGS OVER THE W WITH UPSLOPE WLY FLOW IN THE WAKE OF
THE FROPA...BUT DOWNSLOPING FLOW WL LIKELY CAUSE CIGS TO RISE TO VFR
AT SAW. THE SECOND STRONGER COLD FROPA WL OCCUR IN THE EARLY
EVENVING. CONDITIONS SHOULD DETERIORATE WITH THE INFLUX OF COLDER
AIR BEHIND THIS FNT...WITH MVFR CIGS AT CMX WITH FAVORABLE UPSLOPE
AND GUSTY WNW FLOW.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE ACROSS NORTHERN MINNESOTA WILL DRIFT OVER EASTERN UPPER
MICHIGAN BY LATE AFTERNOON...BEFORE EXITING TO THE NEW ENGLAND
STATES WEDNESDAY...WITH A FEW GUSTS NEARING 30KTS OVER EASTERN LAKE
SUPERIOR LATE TONIGHT INTO EARLY WEDNESDAY. OTHERWISE...WINDS SHOULD
REMAIN BELOW 30KTS THROUGH SUNDAY. A WEAK LOW WILL SLIDE ACROSS LAKE
SUPERIOR WEDNESDAY NIGHT INTO EARLY THURSDAY...FOLLOWED BY A RIDGE
THAT WILL SLOWLY BUILD OVER THE AREA THROUGH SATURDAY MORNING. LOW
PRESSURE WILL THEN NEAR LAKE SUPERIOR SATURDAY NIGHT INTO SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
520 AM EST TUE JAN 31 2012
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL FLOW ACROSS THE
NRN CONUS WITH A SHORTWAVE FROM NW MN INTO CNTRL SD. AT THE SFC...A
LOW PRES WAS LOCATED OVER NW MN WITH A WARM FRONT FROM CNTR MN INTO
SRN WI. RADAR INDICATED PATCHY RETURNS OVER LAKE SUPERIOR AND WRN
UPPER MI SUPPORTED BY ISENTROPIC LIFT NORTH OF THE WARM FRONT.
HOWEVER...LITTLE IF ANY WAS REACHING THE GROUND AS OBS INDICATED
MAINLY JUST MID CLOUDS WITH NO PCPN.
&&
.SHORT TERM...TODAY AND TONIGHT
TODAY...EXPECT THE BEST CHANCE OF MEASURABLE PCPN TO REMAIN NORTH
OF THE CWA THIS MORNING WHERE THE GREATEST LIFT (285-295K LAYER) AND
DEEPER SATURATION OCCURS. OTHERWISE...A SUBSTANTIAL 925-750 MB DRY
LAYER WILL LIMIT ANY CHANCE OF RAIN/SNOW OVER UPPER MI. THERE MAY
STILL BE ENOUGH LOW LEVEL MOISTURE OVER THE NORTH HALF OF THE CWA FOR
SOME PATCHY -FZDZ...ESPECIALLY WHERE SRLY UPSLOPE FLOW PREVAILS. AS
THE SHORTWAVE MOVES THROUGH THIS AFTERNOON A PERIOD OF 700-500 MB
FGEN MAY PRODUCE ADDITIONAL LIFT BUT IS NOT EXPECTED TO BE STRONG
ENOUGH TO OVERCOME THE DRY LAYER BENEATH THE MID CLOUDS. EXPECT CLOUD
COVER TO BE THICK ENOUGH TO LIMIT MAX READINGS TO THE MID AND UPPER
30S DESPITE 900 MB TEMPS TO AROUND 5C.
TONIGHT...CAA IN THE WAKE OF THE SFC LOW DROPPING 850 MB TEMPS TO
NEAR -7C WITH INCREASEING WNW WINDS MAY BE ENOUGH TO SUPPORT SOME
LIGHT LAKE ENHANCED PCPN INTO WRN UPPER MI DURING THE EVENING AND
FOR LOCATIONS EAST OF MARQUETTE OVERNIGHT. SINCE TEMPS IN THE CLOUD
LAYER (DOWN TO -7C TO -10C) WILL ONLY BE MARGINAL FOR ICE
CRYSTALS...-FZDZ POTENTIAL WILL CONTINUE.
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE WILL DOMINATE MUCH OF THIS PERIOD...WITH ONLY A
SLIGHT CHANCE OF OFF AND ON PRECIPITATION. WEATHER TYPE WILL REMAIN
TRICKY WITH AFTERNOON HIGH TEMPS IN THE 30S...LOWS MAINLY IN THE
20S...AND LOW LEVEL MOISTURE STUCK BELOW A STRONG INVERSION.
DRIZZLE OR FREEZING DRIZZLE WILL AGAIN BE A CONCERN TO START US OFF
ON WEDNESDAY. WHILE THE BULK OF MOISTURE WILL EXIT WITH THE SFC LOW
OVER FAR SE ONTARIO/S QUEBEC BY 12Z WEDNESDAY...A SFC TROUGH WILL
REMAIN THROUGH THE KEWEENAW PENINSULA/ISLE ROYALE AREA. LINGERING
LOW LEVEL MOISTURE UNDER NW FLOW WILL BE A CONCERN. THIS TROUGH WILL
SLOWLY ERODE WEST TO EAST THROUGH 00Z THURSDAY AS A RIDGE SLIDES IN.
ALTHOUGH LOW LEVEL MOISTURE REMAINS WEDNESDAY NIGHT /WITH THE
SHORTWAVE SLIDING ACROSS THE CWA/...IT DID NOT SEEM LIKE ENOUGH TO
WARRANT THE LOW POPS. ADDED FLURRIES INSTEAD...AFTER MIDNIGHT TO THE
KEWEENAW PENINSULA AND EAST OF MUNISING NEAR LAKE SUPERIOR WHEN SFC
WINDS BECOME MORE WNW.
THURSDAY NIGHT THROUGH MONDAY...
FORECAST MODELS DIVERGE SIGNIFICANTLY TOWARD THE END OF THE WORK
WEEK...PARTICULARLY WITH THE HANDLING OF LOW PRESSURE TO OUR SOUTH.
THE RESULT IS LOWER CONFIDENCE IN THE ONGOING FORECAST FROM FRIDAY
THROUGH MONDAY. THE 30/18Z GFS IS BACKED UP BY THE 30/12Z CANADIAN
AND TO A MUCH LESSER EXTENT THE DGEX. THEY SUPPORT THE SFC LOW
ORGANIZING OUT OF THE 4 CORNERS REGION THURSDAY...SLIDING OVER KS
FRIDAY NIGHT...IA SATURDAY NIGHT...AND SOUTHERN WI BY SUNDAY MORNING.
STRONG HIGH PRESSURE OVER S ONTARIO/QUEBEC AND LAKE SUPERIOR WILL
ACT TO KEEP MAINLY DRY AIR IN PLACE OVER OUR REGION THROUGH AT LEAST
SATURDAY.
WITH ALL THE DIFFERENCES BETWEEN THE ECMWF AND THE OVERALL
CONSENSUS...THEY DO MERGE IN ON HAVING THE SFC LOW JUST SE OF THE
CWA BY 00Z MONDAY...WITH THE GFS BEING MORE PROGRESSIVE THEREAFTER
AS THE SOUTHERN LOW NEARLY MERGES WITH THE NORTHERN STREAM LOW OVER
HUDSON BAY.
JUST HOW MUCH COLD AIR FILTERS IN BEHIND THE LOW IS A QUESTION. THE
30/18Z GFS SUGGESTS 850MB TEMPS WARMING TO AROUND -1C 00Z SUNDAY
PRIOR TO ANY PRECIP...WITH -2 TO -6C AIR NEAR THE LOW ITSELF. THE
COOL NNW FLOW BEHIND THE SYSTEM SUNDAY NIGHT INTO MONDAY BEING LESS
THAN IMPRESSIVE WITH -6C ABOUT THE COLDEST AIR AVAILABLE. THE COLDER
AIR /BELOW -12C LOOKS/ TO REMAIN OVER N MANITOBA/ONTARIO THROUGH
MONDAY. RUN TO RUN CONSISTENCY WITH THE GFS IS ALSO A BIT OF AN
ISSUE...AS THE 12Z GFS DID MERGE WITH THE NORTHERN STREAM A BIT
EARLIER RESULTING IN COLDER AIR OF -12C TO -14C BY MONDAY ACROSS THE
NW COUNTIES.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
AS A DISTURANCE AND ASSOCIATED WARM FNT APRCHS UPR MI EARLY THIS
MRNG...SOME -FZDZ MAY FALL...ESPECIALLY AT CMX WHERE THE AIR ABV
SHALLOW MOIST LYR IS NOT QUITE AS DRY AS AT SAW AND ESPECIALLY IWD.
BUT UPSLOPE S WIND WL BE MORE CONDUCIVE TO MAINTAINING A LO IFR/
MVFR CIG AT SAW THAN AT THE OTHER 2 SITES. EXPECT MORE LO CLDS/ MVFR
CIGS TO ROLL BACK INTO CMX BY DAYBREAK FOLLOWING THE MOISTENING FM
THE LGT PCPN. A PAIR OF COLD FNTS WILL THEN CROSS THE AREA LATER
TDAY. THERE WL BE A RETURN OF MVFR CIGS OVER THE W WITH UPSLOPE WLY
FLOW IN THE WAKE OF THE FROPA...BUT DOWNSLOPING FLOW WL LIKELY CAUSE
CIGS TO RISE TO VFR AT SAW. THE SECOND STRONGER COLD FROPA WL OCCUR
IN THE EARLY EVNG. CONDITIONS SHOULD DETERIORATE WITH THE INFLUX OF
COLDER AIR BEHIND THIS FNT...WITH CIGS FALLING TO IFR AT CMX WITH
FAVORABLE UPSLOPE AND GUSTY WNW FLOW.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE ACROSS NORTHERN MINNESOTA WILL DRIFT OVER EASTERN UPPER
MICHIGAN BY LATE AFTERNOON...BEFORE EXITING TO THE NEW ENGLAND
STATES WEDNESDAY...WITH A FEW GUSTS NEARING 30KTS OVER EASTERN LAKE
SUPERIOR LATE TONIGHT INTO EARLY WEDNESDAY. OTHERWISE...WINDS SHOULD
REMAIN BELOW 30KTS THROUGH SUNDAY. A WEAK LOW WILL SLIDE ACROSS LAKE
SUPERIOR WEDNESDAY NIGHT INTO EARLY THURSDAY...FOLLOWED BY A RIDGE
THAT WILL SLOWLY BUILD OVER THE AREA THROUGH SATURDAY MORNING. LOW
PRESSURE WILL THEN NEAR LAKE SUPERIOR SATURDAY NIGHT INTO SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS DULUTH MN
606 AM CST TUE JAN 31 2012
.AVIATION...
A LOW PRESSURE SYSTEM WILL TRACK EAST OVER THE REGION THROUGH THE
AFTERNOON. VFR CIGS THIS MORNING WILL LOWER TO MVFR WITH -DZ OR
-RASN WITH THE COLD FRONT/LOW PASSAGE. AS THE LOW DEPARTS TO OVER THE
GREAT LAKES OVERNIGHT...WRAP AROUND MOISTURE AND COOLER AIR WILL
BRING LOWERING CEILINGS AND A POSSIBILITY FOR REDUCED VSBYS AND
BR. THE DRIER AIR ALOFT MAY RESULT IN SOME FZDZ LATE TONIGHT.
HOWEVER...HAVE LEFT ANY MENTION OF FZDZ OUT OF TAFS AT THIS TIME
DUE TO UNCERTAINTIES THAT FAR OUT.
&&
.PREV DISCUSSION... /ISSUED 417 AM CST TUE JAN 31 2012/
SHORT TERM...
A LOW PRESSURE SYSTEM OVER NORTH CENTRAL MINNESOTA WILL MOVE EASTWARD
TODAY AND CONTINUE TO BRING FREEZING RAIN OVER THE IRON RANGE AND
ARROWHEAD THIS MORNING. CONTINUED THE WINTER WEATHER ADVISORY FOR
AREAS BASICALLY NORTH OF HIGHWAY 2 IN MINNESOTA THROUGH NOON. A
PUSH OF DRIER AIR TO THE SOUTHWEST OF THE LOW HAS PARTIALLY
CLEARED THE SKIES ACROSS WEST CENTRAL MINNESOTA. THE PATCHY
FREEZING RAIN SOUTH OF HIGHWAY 2 HAS MOVED EAST OF THE FORECAST
AREA AND DIMINISHED AND THEREFORE DROPPED THE WINTER WEATHER
ADVISORY FOR THOSE LOCATIONS. A COLD FRONTAL BOUNDARY DRAPED OVER
EXTREME NORTHWESTERN MINNESOTA AND EASTERN NORTH DAKOTA IS THE
FOCUS OF THE NEXT ROUND OF PRECIPITATION. PER SURFACE
OBSERVATIONS...MOST OF THE PRECIPITATION IS FALLING AS FREEZING
RAIN. 4 KM WRF AND HRRR HAVE THIS BAND OF PRECIPITATION
DISSIPATING AS IT MOVES EASTWARD. TEMPERATURES WILL BE WARM
ENOUGH BY 18Z THAT WILL BRING THE PRECIPITATION TO MAINLY A
LIQUID STATE IF IT HOLDS TOGETHER. AS THE FRONTAL BOUNDARY MOVES
INTO NORTHWESTERN WISCONSIN...SOME PATCHY FREEZING DRIZZLE IS
POSSIBLE ALONG THE SOUTH SHORE OF LAKE SUPERIOR...EAST OF
SUPERIOR...IN THE EARLY EVENING WITH THE LOSS OF DIURNAL WARMING.
THERE STILL WILL BE A CHANCE OF PRECIPITATION ON THE BACK SIDE OF
THE LOW EARLY TONIGHT IN THE FORM OF LIGHT SNOW ALONG THE
BORDERLAND. TEMPERATURES BEHIND THE FRONT WILL BE MODIFIED BY
PACIFIC AIR ALLOWING FOR THE 30S TO CONTINUE INTO WEDNESDAY. A
WEAK SHORTWAVE WILL MOVE OUT OF CANADA WEDNESDAY AFTERNOON THAT
WILL BRING A SLIGHT CHANCE OF LIGHT SNOW TO THE NORTHWESTERN PART
OF THE FORECAST AREA.
EXTENDED...WEDNESDAY NIGHT THROUGH TUESDAY.
A WAVY ZONAL FLOW KEEPS CLOUDS AND A FEW PERIODS OF SCHC POPS FOR
-SN IN THE FCST THROUGH THE REMAINDER OF THE WEEK. A LONG WAVE
TROUGH DEEPENS INTO A CLOSED LOW OVER THE SRN/CENTRAL PLAINS THROUGH THE
WEEKEND. LATEST GFS/ECM/GEM HAVE SIMILAR SOLUTIONS SUGGESTING THE
BUILDING RIDGE BEHIND THE LOW BECOMES PINCHED OFF OVER THE NRN
PLAINS/SRN CANADA DURING THIS TIME. THIS WOULD BRING QUITE WEATHER
AND ANOTHER STRETCH OF WELL ABOVE NORMAL TEMPS WITH DAYTIME HIGHS IN
THE 30S FOR THE DLH CWA. MODELS CONTINUE TO SHOW DIFFERENCES IN HOW
FAR NORTH THE CUT OFF LOW MIGRATES INTO THE BEGINNING OF NEXT WEEK
WITH THE GFS THE MOST PROGRESSIVE AND FURTHEST NORTH WITH THE LOW
LIFTING OVER THE SRN GREAT LAKES BY SUNDAY. ATTM...THE PRECIP
ASSOCIATED WITH THE SRN STREAM LOW LOOKS TO REMAIN SOUTH OF THE
FA.
AVIATION...01/31/06Z ISSUANCE...
VFR WITH AREAS OF HIGH-END MVFR IN CLOUDS AND FREEZING DRIZZLE OR
FREEZING RAIN. FREEZING RAIN MAY MIX WITH LIGHT SNOW FROM
LONG VILLE-DULUTH ON NORTH TUESDAY MORNING. LOW-END VFR WITH A
LITTLE HIGH-END MVFR IN CLOUDS WILL PERSIST TUESDAY AFTERNOON AND
EVENING.
&&
.POINT TEMPS/POPS...
DLH 36 22 34 22 / 20 10 10 10
INL 32 21 34 20 / 50 20 20 10
BRD 36 24 38 20 / 10 10 10 0
HYR 39 24 36 21 / 10 10 10 0
ASX 38 25 36 23 / 20 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ010>012-
018>021-026.
WI...NONE.
&&
$$
SHORT TERM...KK
LONG TERM....GRANING
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS DULUTH MN
417 AM CST TUE JAN 31 2012
.SHORT TERM...
A LOW PRESSURE SYSTEM OVER NORTH CENTRAL MINNESOTA WILL MOVE EASTWARD
TODAY AND CONTINUE TO BRING FREEZING RAIN OVER THE IRON RANGE AND
ARROWHEAD THIS MORNING. CONTINUED THE WINTER WEATHER ADVISORY FOR
AREAS BASICALLY NORTH OF HIGHWAY 2 IN MINNESOTA THROUGH NOON. A
PUSH OF DRIER AIR TO THE SOUTHWEST OF THE LOW HAS PARTIALLY
CLEARED THE SKIES ACROSS WEST CENTRAL MINNESOTA. THE PATCHY
FREEZING RAIN SOUTH OF HIGHWAY 2 HAS MOVED EAST OF THE FORECAST
AREA AND DIMINISHED AND THEREFORE DROPPED THE WINTER WEATHER
ADVISORY FOR THOSE LOCATIONS. A COLD FRONTAL BOUNDARY DRAPED OVER
EXTREME NORTHWESTERN MINNESOTA AND EASTERN NORTH DAKOTA IS THE
FOCUS OF THE NEXT ROUND OF PRECIPITATION. PER SURFACE
OBSERVATIONS...MOST OF THE PRECIPITATION IS FALLING AS FREEZING
RAIN. 4 KM WRF AND HRRR HAVE THIS BAND OF PRECIPITATION
DISSIPATING AS IT MOVES EASTWARD. TEMPERATURES WILL BE WARM
ENOUGH BY 18Z THAT WILL BRING THE PRECIPITATION TO MAINLY A
LIQUID STATE IF IT HOLDS TOGETHER. AS THE FRONTAL BOUNDARY MOVES
INTO NORTHWESTERN WISCONSIN...SOME PATCHY FREEZING DRIZZLE IS
POSSIBLE ALONG THE SOUTH SHORE OF LAKE SUPERIOR...EAST OF
SUPERIOR...IN THE EARLY EVENING WITH THE LOSS OF DIURNAL WARMING.
THERE STILL WILL BE A CHANCE OF PRECIPITATION ON THE BACK SIDE OF
THE LOW EARLY TONIGHT IN THE FORM OF LIGHT SNOW ALONG THE
BORDERLAND. TEMPERATURES BEHIND THE FRONT WILL BE MODIFIED BY
PACIFIC AIR ALLOWING FOR THE 30S TO CONTINUE INTO WEDNESDAY. A
WEAK SHORTWAVE WILL MOVE OUT OF CANADA WEDNESDAY AFTERNOON THAT
WILL BRING A SLIGHT CHANCE OF LIGHT SNOW TO THE NORTHWESTERN PART
OF THE FORECAST AREA.
EXTENDED...WEDNESDAY NIGHT THROUGH TUESDAY.
A WAVY ZONAL FLOW KEEPS CLOUDS AND A FEW PERIODS OF SCHC POPS FOR
-SN IN THE FCST THROUGH THE REMAINDER OF THE WEEK. A LONG WAVE
TROUGH DEEPENS INTO A CLOSED LOW OVER THE SRN/CENTRAL PLAINS THROUGH THE
WEEKEND. LATEST GFS/ECM/GEM HAVE SIMILAR SOLUTIONS SUGGESTING THE
BUILDING RIDGE BEHIND THE LOW BECOMES PINCHED OFF OVER THE NRN
PLAINS/SRN CANADA DURING THIS TIME. THIS WOULD BRING QUITE WEATHER
AND ANOTHER STRETCH OF WELL ABOVE NORMAL TEMPS WITH DAYTIME HIGHS IN
THE 30S FOR THE DLH CWA. MODELS CONTINUE TO SHOW DIFFERENCES IN HOW
FAR NORTH THE CUT OFF LOW MIGRATES INTO THE BEGINNING OF NEXT WEEK
WITH THE GFS THE MOST PROGRESSIVE AND FURTHEST NORTH WITH THE LOW
LIFTING OVER THE SRN GREAT LAKES BY SUNDAY. ATTM...THE PRECIP
ASSOCIATED WITH THE SRN STREAM LOW LOOKS TO REMAIN SOUTH OF THE
FA.
&&
.AVIATION...01/31/06Z ISSUANCE...
VFR WITH AREAS OF HIGH-END MVFR IN CLOUDS AND FREEZING DRIZZLE OR
FREEZING RAIN. FREEZING RAIN MAY MIX WITH LIGHT SNOW FROM
LONGVILLE-DULUTH ON NORTH TUESDAY MORNING. LOW-END VFR WITH A
LITTLE HIGH-END MVFR IN CLOUDS WILL PERSIST TUESDAY AFTERNOON AND
EVENING.
&&
.POINT TEMPS/POPS...
DLH 36 22 34 22 / 20 10 10 10
INL 32 21 34 20 / 50 20 20 10
BRD 36 24 38 20 / 10 10 10 0
HYR 39 24 36 21 / 10 10 10 0
ASX 38 25 36 23 / 20 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ010>012-
018>021-026.
WI...NONE.
&&
$$
SHORT TERM...KK
LONG TERM....GRANING
AVIATION...EOM
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
216 PM CST TUE JAN 31 2012
.DISCUSSION...
1054 AM CST
FOR MORNING UPDATE...
SOME MINOR TWEAKS TO GOING TEMP/SKY AND WX/POP GRIDS...THOUGH
FORECAST REMAINS LARGELY ON TRACK.
LOW PRESSURE POISED TO MOVE EAST ACROSS THE UPPER PENINSULA OF
MICHIGAN THIS AFTERNOON IN RESPONSE TO RATHER PRONOUNCED MID LEVEL
SHORT WAVE TROUGH PROPAGATING ACROSS THE UPPER MIDWEST. WARM SECTOR
SOUTH OF THE LOW ALREADY WARMING INTO THE LOW-MID 50S ACROSS THE CWA
AS OF 16Z. PERUSAL OF UPSTREAM SOUNDINGS AND LATEST MODEL LOW LEVEL
THERMAL PROGS CONTINUE TO SUGGEST MAX TEMPS ACROSS THE FORECAST AREA
POTENTIALLY RANGING FROM THE UPPER 50S NORTH TO THE MID 60S SOUTH...
HOWEVER GOES VISIBLE SATELLITE IMAGERY DOES DEPICT DEVELOPMENT OF
SOME STRATUS/STRATO CU ACROSS MO/IL IN REGION OF LOW LEVEL MOIST
ADVECTION AHEAD OF APPROACHING SHORT WAVE AND SURFACE TROUGH/COLD
FRONT. THIS CONTINUES TO MAKE FOR SOMEWHAT TRICKY AFTERNOON TEMP
FORECAST...WITH SOME VARIABLE COVERAGE IN OVERCAST CONDITIONS BUT AN
OVERALL INCREASE IN CLOUDINESS THROUGH THE AFTERNOON. HAVE TWEAKED
TEMPS UP JUST A LITTLE IN SOME SPOTS BASED ON TRENDS AND EXTRAPOLATED
NEAR TERM CLOUD TRENDS...BUT CANT ARGUE TOO MUCH WITH GOING
FORECAST.
IN ADDITION...POTENTIAL FOR DRIZZLE/SPRINKLES NOT LOOKING VERY
IMPRESSIVE AT THIS TIME...THOUGH GUIDANCE CONTINUES TO SUGGEST SOME
INCREASE IN POTENTIAL FOR SOME PATCHY LIGHT PRECIP ACROSS MAINLY THE
SOUTHEAST CWA VERY LATE THIS AFTERNOON/EVENING. HAVE ADJUSTED
LOCATION/COVERAGE ACCORDINGLY.
RATZER
//PREV DISCUSSION...
317 AM CST
THE ATTENTION ON THIS FORECAST WAS PRIMARILY DIRECTED TO
TEMPERATURES...WITH AN EMPHASIS ON TODAY AS NEAR RECORD TO RECORD
WARMTH IS ON PAR AGAIN FOR THE AREA. QUITE A DIFFERENCE FROM ONE
YEAR AGO TODAY...WHICH SAW THE AREA PREPARING FOR THE THIRD
LARGEST SNOWSTORM ON RECORD. AN ADDITIONAL CHALLENGE IN THE
FORECAST IS THAT BOTH WEDNESDAY AND THURSDAY ALSO ARE APPEARING
LIKELY TO BE WARMER THAN INITIALLY THOUGHT.
TEMPERATURES ARE STARTING NEARLY 30 DEGREES ABOVE NORMAL THIS
FINAL DAY OF JANUARY...WHICH IS FITTING FOR THIS MONTH THAT IS
AVERAGING 5 TO 6 DEGREES ABOVE NORMAL. SOUTHERLY WINDS AND
INCREASING LOW-LEVEL MOISTURE THROUGHOUT LAST NIGHT INTO THIS
MORNING HAVE AIDED THESE MILD READINGS. THE ANTICIPATED
STRATUS/STRATOCU IS DEVELOPING QUICKLY NORTHEAST FROM THE SOUTHERN
PLAINS/OZARKS EARLY THIS MORNING...LINING UP WELL WITH MODEL
DIAGNOSTIC SOLUTIONS OF MOISTURE TRANSPORT AND CONVERGENCE IN THE
LOW LEVELS /ROUGHLY 850-925MB/.
EVEN AHEAD OF THESE LOW CLOUDS...MODEL GUIDANCE CONTINUES TO SHOW
BOTH A TOO MOIST AND COOL BIAS IN THE LOW-LEVELS...SOME LIKELY DUE
TO FALSE SNOW COVER AND/OR TOO COLD OF GROUND COVER. JUST THE
31.00 GFS AND NAMELY THE NAM SOUNDINGS ACROSS THE AREA REVEALED
THIS BIAS ALMOST IMMEDIATELY AFTER THEIR INITIALIZATION HOURS. SO
HAVE GUIDED MORE ON ABSOLUTE MOISTURE VALUES AND SATURATION NEAR
THE TOP OF THE ADAPTED MIXED-LAYER LATER THIS MORNING /~4000 FT/
FOR CLOUD INDICATIONS. THE MOISTURE CONVERGENCE FORECAST FROM THE
RUC AND NAM LINE UP WELL FROM SOUTHEAST IA INTO NORTHERN IL AND
EXPECT THE CLOUDS TO EXPAND INTO THAT AREA DURING THE LATE
MORNING. RUC PARCEL TRAJECTORIES WOULD INDICATE NEAR A 12 PM
ARRIVAL IN CHICAGO BASED ON CURRENT PLACEMENT OF THE LOW
CLOUDS...BUT SOME LEAD SATURATION MAY CAUSE IT TO BE A LITTLE
QUICKER. THE STRATUS PLUME AND HOW QUICKLY IT MOVES IN WILL LIKELY
IMPACT TEMPERATURES A FEW DEGREES.
AS FOR THOSE TEMPERATURES TODAY...LOCAL ANALYSIS HERE HAS SHOWN
THAT BIAS-CORRECTED GUIDANCE IS WORKING VERY WELL IN THESE VERY
MILD STRETCHES THIS WINTER...PARTICULARLY THE GEM AND THE EC. HAVE
BLENDED OUR GOING FORECAST HEAVILY TOWARDS THESE SOLUTIONS...AND
EVEN ADJUSTED UP FROM THERE IN SOME AREAS. WHILE THE CLOUDS WILL
EXPAND IN...CONTINUED LOW-LEVEL WARM ADVECTION WILL LIKELY
SUPPORT INCREASING SURFACE TEMPERATURES INTO THE
AFTERNOON...ALBEIT AT A SLOWER RATE. SO HAVE SOME QUICK MORNING
WARMING FORECAST FROM THE HIGH STARTING POINT VALUES...AND THEN
GRADUAL INCREASE THIS AFTERNOON. THIS APPROACH YIELDS REMARKABLY
MILD UPPER 50S TO LOWER 60 DEGREE READINGS BEING LIKELY IN SEVERAL
AREAS. EVEN MID 60S COULD BE TOUCHED IN THE EASTERN HALF OF THE
AREA IF THE RATE OF WARMING AFTER THE CLOUDS ARRIVE IS HIGHER THAN
INDICATED. PLEASE SEE THE CLIMATE SECTION BELOW FOR RECORD
INFORMATION.
AS FOR PRECIPITATION CHANCES THIS AFTERNOON INTO TONIGHT...THE
DEPTH OF THE CLOUDS INCREASE QUICKLY LATE THIS AFTERNOON INTO THE
EVENING. MARGINAL SATURATED ISENTROPIC ASCENT AND CONVERGENCE
AHEAD OF A COLD FRONT MOVING THROUGH...MAY OFFER SPORADIC LIGHT
RAIN OR DRIZZLE IN THE SOUTHEAST HALF OF THE FORECAST AREA DURING
THE LATE AFTERNOON AND EVENING. THE LIGHT RAIN MAY ACTUALLY BE
MORE SHOWERY...BUT LIMITED FORCING WILL PREVENT ANYTHING
APPRECIABLE.
WEDNESDAY AND THURSDAY...WHILE LOW-LEVEL TEMPERATURES ARE FORECAST
TO COOL DURING THIS PERIOD...THEY ARE STILL ON THE WARMER THAN
NORMAL SIDE. THE LACK OF SNOW COVER TOO SHOULD AID IN THE WARMER
BIAS-CORRECTED GUIDANCE BEING MORE ON TRACK. CLOUDS ALSO LOOK
LIMITED...ALTHOUGH CONFIDENCE IS CURRENTLY LOW ON WEDNESDAY
MORNING WITH A SOMEWHAT LIMITED SURGE BEHIND THIS FRONT MEANING
LINGERING STRATUS IS POSSIBLE. IF NOT THOUGH...TEMPERATURES
GETTING TO 50 ON WEDNESDAY SEEM PROBABLE...AND THEN WELL INTO THE
40S ON THURSDAY. RIDGING SHOULD ALLOW FOR ONLY CIRRUS BY THURSDAY.
LATE THIS WEEK INTO THE WEEKEND...THE PROGRESSIVE WESTERLY PATTERN
IS EXPECTED TO SLOW DOWN WITH A CUT OFF LOW AND A GENERAL BLOCKING
PATTERN DEVELOPING TO OUR WEST. DETAILS HAVE VARIED
SIGNIFICANTLY...BUT A CLEAR TREND IN THE GUIDANCE IS SLOWER WITH
PROGRESSING FORCING FOR PRECIPITATION EAST INTO OUR AREA. GIVEN
THAT PATTERN...THAT SEEMS REASONABLE AND HAVE ADJUSTED THE BLENDED
GUIDANCE FORECAST THAT WAY. THE SLOWER 31.00 EC WAS FOLLOWED
CLOSELY FOR DETAILS. SOME FORM OF INVERTED TROUGH OR WEAK SURFACE
LOW IS LIKELY TO DEVELOP AS THE CLOSED UPPER CIRCULATION WORKS
EAST...AND SUCH A FEATURE WOULD ALSO NOT FAVOR PRECIP FAR TO ITS
EAST. SO ONLY HAVE SMALL CHANCES DURING THE WEEKEND...WITH
FORECAST SOUNDINGS AND GENERAL THICKNESSES SLIGHTLY MORE
SUPPORTIVE OF RAIN THAN SNOW IF PRECIP OCCURS. IT IS STILL
FAVORED THAT NO PRECIPITATION WILL OCCUR THIS WEEKEND...ESPECIALLY
IF THE EC SOUTHERN TRACK OF THE CLOSED LOW WERE TO COME TO
FRUITION.
&&
.CLIMATE...
THE RECORD HIGH TODAY FOR CHICAGO IS 65 IN 1989. THE HIGH
TEMPERATURE IS MOST LIKELY TO BE 3 TO 7 DEGREES SHY OF THIS...BUT
IT COULD END UP GETTING VERY CLOSE. THE GOING FORECAST IS FOR THIS
TO BE THE WARMEST DAY THIS METEOROLOGICAL WINTER SO FAR. THIS WILL
BE THE TENTH DAY IN AT LEAST THE 50S SINCE DECEMBER 1ST /BASICALLY
ONE DAY A WEEK THIS WINTER SO FAR/. AS FOR ROCKFORD THE RECORD
HIGH IS 63 ALSO IN 1989. THE HIGH TEMPERATURE IS EXPECTED TO FALL
SEVERAL DEGREES SHORT...BUT CONFIDENCE IS LOWER AT ROCKFORD
DEPENDING ON HOW THE STRATUS EVOLVES IN /IT MAY REMAIN SOUTH OF
ROCKFORD/. THIS WILL BE THE NINTH DAY IN AT LEAST THE 50S THIS
METEOROLOGICAL WINTER AT ROCKFORD.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS THROUGH EARLY THIS EVENING.
* SWLY GUSTS TO 25KT DROPPING OFF LATE THIS AFTERNOON.
* SLIGHT CHANCE OF VIS DROPPING TO MVFR IN HZ/BR DURG EARLY
MORNING HOURS.
LENNING
//DISCUSSION...UPDATED 18Z...
GUSTY SWLY WINDS WILL CONTINUE INTO THE AFTERNOON AHEAD OF A WEAK
COLD FRONT MOVING INTO ERN IOWA. A PLUME OF LOW LEVEL MOISTURE
AHEAD OF THE FRONT HAS ALLOWED THE FORMATION OF A BKN STRATOCU
DECK EXTENDING FROM NRN MO TO NRN IL/IN. BASES OF THE CLOUD DECK
SHOULD STAY AT ARND 2.5KFT. AT ISSUANCE TIME...ORD/DPA/GYY WE JUST
TO THE NORTH OF THE BKN MVFR CIGS...AND ANTICIPATE THAT THE
COVERAGE SHOULD INCREASE TO BKN WITHIN THE HOUR OF ISSUANCE.
THE FRONT WILL STEADILY PUSH EWD THIS AFTERNOON...KEEPING WINDS
BRISK AND GUSTY UNTIL THE ASSOCIATED TROUGH CROSSES THE AREA LATE
THIS AFTERNOON AND EARLY THIS EVENING...RELAXING THE PRESSURE
GRADIENT OVER THE REGION. FOLLOWING THE FROPA...HIGH PRESSURE WILL
SPREAD ACROSS THE CENTRAL PLAINS AND INTO THE MIDWEST...ALLOWING
WINDS TO QUICKLY DROP OFF. DRIER AIR BEHIND THE FRONT SHOULD BRING
QUICKLY CLEARING SKIES. THE MAIN CONCERN FOR THE OVERNIGHT HOURS
WILL SHIFT TO VISIBILITY. SOME OF THE NUMERICAL GUIDANCE IS
INDICATING A CHANCE FOR VISBY REDUCTION TO MVFR AS SKIES CLEAR AND
WINDS DECREASE. THE ONE LIMITING FACTOR FOR VISIBILITY WILL BE LOW
LEVEL MOISTURE. THE AIRMASS BEHIND THE FRONT WILL BE RATHER DRY
AND IT IS UNCERTAIN THAT THERE WILL BE ENOUGH COOLING TO DROP THE
TEMPERATURE CLOSE ENOUGH TO THE DEWPOINT TO LEAD TO BR FORMATION.
SO...HAVE ONLY GONE WITH 6SM HZ FOR THE EARLY MORNING HOURS TO
BEGIN A TREND AND WILL MONITOR CONDITIONS CLOSELY TO SEE IF A
LOWER VISIBILITY FORECAST WILL BE WARRANTED FOR THE MORNING RUSH
HOURS. OTHERWISE...TOMORROW IS SHAPING UP TO BE A QUIET DAY WITH
NO OPERATIONALLY SIGNIFICANT WEATHER CONCERNS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE ON CEILING TRENDS. UPSTREAM OBS MAY BE
SOMEWHAT MORE OPTIMISTIC THAN TRENDS IN LATEST TAFS. THIS WOULD
RESULT IN SHORTER PERIOD OF MVFR.
* MEDIUM CONFIDENCE IN GUST SPEEDS AND TIME THAT THEY WOULD BE
DIMINISHING THIS AFTERNOON.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH FRIDAY...VFR
* SATURDAY AND SUNDAY...SLIGHT CHANCE OF RAIN OR SNOW
* MONDAY...VFR
SHEA
&&
.MARINE...
216 PM CST
LOW PRESSURE ACROSS NORTH CENTRAL WI AND FAR SOUTH CENTRAL LAKE
SUPERIOR EARLY THIS AFTERNOON CONTINUES TO LIFT A WARM FRONT
NORTHWARD ACROSS THE NORTHERN PORTION OF LAKE MICHIGAN. TO THE SOUTH
OF THIS FRONT WINDS ARE GUSTY UP TO 30 KT AT TIMES FROM THE
SOUTHWEST. THIS LOW WILL CONTINUE EASTWARD TO THE UPPER PENINSULA OF
MICHIGAN LATER THIS AFTERNOON AND EVENING. AS THIS HAPPENS...A COLD
FRONT WILL MOVE ACROSS LAKE MICHIGAN BY MID TO LATE EVENING. THIS
WILL PRODUCE A WIND SHIFT TO THE WEST NORTHWEST LATER THIS EVENING
AND OVERNIGHT. THESE WINDS WILL GRADUALLY ABATE ON WEDNESDAY AS A
BROAD AREA OF HIGH PRESSURE BUILDS IN FROM THE WEST. THIS BROAD HIGH
LOOKS TO PRODUCE A PERIOD OF LIGHT AND VARIABLE WINDS ACROSS LAKE
MICHIGAN ON THURSDAY INTO FRIDAY.
AS WE HEAD INTO THE COMING WEEKEND A RATHER COMPLEX WEATHER PATTERN
IS FORECAST TO OCCUR ACROSS THE WESTERN AND CENTRAL CONUS. THIS
PATTERN WILL LIKELY LEAD TO THE DEVELOPMENT OF LOW PRESSURE ACROSS
THE PLAINS. HOWEVER...DUE TO THE COMPLEX NATURE OF THE EVOLVING
UPPER LEVEL WEATHER PATTERN DURING THIS TIME...UNCERTAINTY ON THE
TIMING AND TRACK OF THIS LOW INTO THIS COMING WEEKEND REMAINS HIGHER
THAN AVERAGE. ULTIMATELY...THIS WILL HAVE LARGE IMPACTS ON THE WIND
SPEEDS AND DIRECTIONS ACROSS THE LAKE THIS WEEKEND INTO EARLY NEXT
WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
214 PM CST TUE JAN 31 2012
.DISCUSSION...
1054 AM CST
FOR MORNING UPDATE...
SOME MINOR TWEAKS TO GOING TEMP/SKY AND WX/POP GRIDS...THOUGH
FORECAST REMAINS LARGELY ON TRACK.
LOW PRESSURE POISED TO MOVE EAST ACROSS THE UPPER PENINSULA OF
MICHIGAN THIS AFTERNOON IN RESPONSE TO RATHER PRONOUNCED MID LEVEL
SHORT WAVE TROUGH PROPAGATING ACROSS THE UPPER MIDWEST. WARM SECTOR
SOUTH OF THE LOW ALREADY WARMING INTO THE LOW-MID 50S ACROSS THE CWA
AS OF 16Z. PERUSAL OF UPSTREAM SOUNDINGS AND LATEST MODEL LOW LEVEL
THERMAL PROGS CONTINUE TO SUGGEST MAX TEMPS ACROSS THE FORECAST AREA
POTENTIALLY RANGING FROM THE UPPER 50S NORTH TO THE MID 60S SOUTH...
HOWEVER GOES VISIBLE SATELLITE IMAGERY DOES DEPICT DEVELOPMENT OF
SOME STRATUS/STRATO CU ACROSS MO/IL IN REGION OF LOW LEVEL MOIST
ADVECTION AHEAD OF APPROACHING SHORT WAVE AND SURFACE TROUGH/COLD
FRONT. THIS CONTINUES TO MAKE FOR SOMEWHAT TRICKY AFTERNOON TEMP
FORECAST...WITH SOME VARIABLE COVERAGE IN OVERCAST CONDITIONS BUT AN
OVERALL INCREASE IN CLOUDINESS THROUGH THE AFTERNOON. HAVE TWEAKED
TEMPS UP JUST A LITTLE IN SOME SPOTS BASED ON TRENDS AND EXTRAPOLATED
NEAR TERM CLOUD TRENDS...BUT CANT ARGUE TOO MUCH WITH GOING
FORECAST.
IN ADDITION...POTENTIAL FOR DRIZZLE/SPRINKLES NOT LOOKING VERY
IMPRESSIVE AT THIS TIME...THOUGH GUIDANCE CONTINUES TO SUGGEST SOME
INCREASE IN POTENTIAL FOR SOME PATCHY LIGHT PRECIP ACROSS MAINLY THE
SOUTHEAST CWA VERY LATE THIS AFTERNOON/EVENING. HAVE ADJUSTED
LOCATION/COVERAGE ACCORDINGLY.
RATZER
//PREV DISCUSSION...
317 AM CST
THE ATTENTION ON THIS FORECAST WAS PRIMARILY DIRECTED TO
TEMPERATURES...WITH AN EMPHASIS ON TODAY AS NEAR RECORD TO RECORD
WARMTH IS ON PAR AGAIN FOR THE AREA. QUITE A DIFFERENCE FROM ONE
YEAR AGO TODAY...WHICH SAW THE AREA PREPARING FOR THE THIRD
LARGEST SNOWSTORM ON RECORD. AN ADDITIONAL CHALLENGE IN THE
FORECAST IS THAT BOTH WEDNESDAY AND THURSDAY ALSO ARE APPEARING
LIKELY TO BE WARMER THAN INITIALLY THOUGHT.
TEMPERATURES ARE STARTING NEARLY 30 DEGREES ABOVE NORMAL THIS
FINAL DAY OF JANUARY...WHICH IS FITTING FOR THIS MONTH THAT IS
AVERAGING 5 TO 6 DEGREES ABOVE NORMAL. SOUTHERLY WINDS AND
INCREASING LOW-LEVEL MOISTURE THROUGHOUT LAST NIGHT INTO THIS
MORNING HAVE AIDED THESE MILD READINGS. THE ANTICIPATED
STRATUS/STRATOCU IS DEVELOPING QUICKLY NORTHEAST FROM THE SOUTHERN
PLAINS/OZARKS EARLY THIS MORNING...LINING UP WELL WITH MODEL
DIAGNOSTIC SOLUTIONS OF MOISTURE TRANSPORT AND CONVERGENCE IN THE
LOW LEVELS /ROUGHLY 850-925MB/.
EVEN AHEAD OF THESE LOW CLOUDS...MODEL GUIDANCE CONTINUES TO SHOW
BOTH A TOO MOIST AND COOL BIAS IN THE LOW-LEVELS...SOME LIKELY DUE
TO FALSE SNOW COVER AND/OR TOO COLD OF GROUND COVER. JUST THE
31.00 GFS AND NAMELY THE NAM SOUNDINGS ACROSS THE AREA REVEALED
THIS BIAS ALMOST IMMEDIATELY AFTER THEIR INITIALIZATION HOURS. SO
HAVE GUIDED MORE ON ABSOLUTE MOISTURE VALUES AND SATURATION NEAR
THE TOP OF THE ADAPTED MIXED-LAYER LATER THIS MORNING /~4000 FT/
FOR CLOUD INDICATIONS. THE MOISTURE CONVERGENCE FORECAST FROM THE
RUC AND NAM LINE UP WELL FROM SOUTHEAST IA INTO NORTHERN IL AND
EXPECT THE CLOUDS TO EXPAND INTO THAT AREA DURING THE LATE
MORNING. RUC PARCEL TRAJECTORIES WOULD INDICATE NEAR A 12 PM
ARRIVAL IN CHICAGO BASED ON CURRENT PLACEMENT OF THE LOW
CLOUDS...BUT SOME LEAD SATURATION MAY CAUSE IT TO BE A LITTLE
QUICKER. THE STRATUS PLUME AND HOW QUICKLY IT MOVES IN WILL LIKELY
IMPACT TEMPERATURES A FEW DEGREES.
AS FOR THOSE TEMPERATURES TODAY...LOCAL ANALYSIS HERE HAS SHOWN
THAT BIAS-CORRECTED GUIDANCE IS WORKING VERY WELL IN THESE VERY
MILD STRETCHES THIS WINTER...PARTICULARLY THE GEM AND THE EC. HAVE
BLENDED OUR GOING FORECAST HEAVILY TOWARDS THESE SOLUTIONS...AND
EVEN ADJUSTED UP FROM THERE IN SOME AREAS. WHILE THE CLOUDS WILL
EXPAND IN...CONTINUED LOW-LEVEL WARM ADVECTION WILL LIKELY
SUPPORT INCREASING SURFACE TEMPERATURES INTO THE
AFTERNOON...ALBEIT AT A SLOWER RATE. SO HAVE SOME QUICK MORNING
WARMING FORECAST FROM THE HIGH STARTING POINT VALUES...AND THEN
GRADUAL INCREASE THIS AFTERNOON. THIS APPROACH YIELDS REMARKABLY
MILD UPPER 50S TO LOWER 60 DEGREE READINGS BEING LIKELY IN SEVERAL
AREAS. EVEN MID 60S COULD BE TOUCHED IN THE EASTERN HALF OF THE
AREA IF THE RATE OF WARMING AFTER THE CLOUDS ARRIVE IS HIGHER THAN
INDICATED. PLEASE SEE THE CLIMATE SECTION BELOW FOR RECORD
INFORMATION.
AS FOR PRECIPITATION CHANCES THIS AFTERNOON INTO TONIGHT...THE
DEPTH OF THE CLOUDS INCREASE QUICKLY LATE THIS AFTERNOON INTO THE
EVENING. MARGINAL SATURATED ISENTROPIC ASCENT AND CONVERGENCE
AHEAD OF A COLD FRONT MOVING THROUGH...MAY OFFER SPORADIC LIGHT
RAIN OR DRIZZLE IN THE SOUTHEAST HALF OF THE FORECAST AREA DURING
THE LATE AFTERNOON AND EVENING. THE LIGHT RAIN MAY ACTUALLY BE
MORE SHOWERY...BUT LIMITED FORCING WILL PREVENT ANYTHING
APPRECIABLE.
WEDNESDAY AND THURSDAY...WHILE LOW-LEVEL TEMPERATURES ARE FORECAST
TO COOL DURING THIS PERIOD...THEY ARE STILL ON THE WARMER THAN
NORMAL SIDE. THE LACK OF SNOW COVER TOO SHOULD AID IN THE WARMER
BIAS-CORRECTED GUIDANCE BEING MORE ON TRACK. CLOUDS ALSO LOOK
LIMITED...ALTHOUGH CONFIDENCE IS CURRENTLY LOW ON WEDNESDAY
MORNING WITH A SOMEWHAT LIMITED SURGE BEHIND THIS FRONT MEANING
LINGERING STRATUS IS POSSIBLE. IF NOT THOUGH...TEMPERATURES
GETTING TO 50 ON WEDNESDAY SEEM PROBABLE...AND THEN WELL INTO THE
40S ON THURSDAY. RIDGING SHOULD ALLOW FOR ONLY CIRRUS BY THURSDAY.
LATE THIS WEEK INTO THE WEEKEND...THE PROGRESSIVE WESTERLY PATTERN
IS EXPECTED TO SLOW DOWN WITH A CUT OFF LOW AND A GENERAL BLOCKING
PATTERN DEVELOPING TO OUR WEST. DETAILS HAVE VARIED
SIGNIFICANTLY...BUT A CLEAR TREND IN THE GUIDANCE IS SLOWER WITH
PROGRESSING FORCING FOR PRECIPITATION EAST INTO OUR AREA. GIVEN
THAT PATTERN...THAT SEEMS REASONABLE AND HAVE ADJUSTED THE BLENDED
GUIDANCE FORECAST THAT WAY. THE SLOWER 31.00 EC WAS FOLLOWED
CLOSELY FOR DETAILS. SOME FORM OF INVERTED TROUGH OR WEAK SURFACE
LOW IS LIKELY TO DEVELOP AS THE CLOSED UPPER CIRCULATION WORKS
EAST...AND SUCH A FEATURE WOULD ALSO NOT FAVOR PRECIP FAR TO ITS
EAST. SO ONLY HAVE SMALL CHANCES DURING THE WEEKEND...WITH
FORECAST SOUNDINGS AND GENERAL THICKNESSES SLIGHTLY MORE
SUPPORTIVE OF RAIN THAN SNOW IF PRECIP OCCURS. IT IS STILL
FAVORED THAT NO PRECIPITATION WILL OCCUR THIS WEEKEND...ESPECIALLY
IF THE EC SOUTHERN TRACK OF THE CLOSED LOW WERE TO COME TO
FRUITION.
&&
.CLIMATE...
THE RECORD HIGH TODAY FOR CHICAGO IS 65 IN 1989. THE HIGH
TEMPERATURE IS MOST LIKELY TO BE 3 TO 7 DEGREES SHY OF THIS...BUT
IT COULD END UP GETTING VERY CLOSE. THE GOING FORECAST IS FOR THIS
TO BE THE WARMEST DAY THIS METEOROLOGICAL WINTER SO FAR. THIS WILL
BE THE TENTH DAY IN AT LEAST THE 50S SINCE DECEMBER 1ST /BASICALLY
ONE DAY A WEEK THIS WINTER SO FAR/. AS FOR ROCKFORD THE RECORD
HIGH IS 63 ALSO IN 1989. THE HIGH TEMPERATURE IS EXPECTED TO FALL
SEVERAL DEGREES SHORT...BUT CONFIDENCE IS LOWER AT ROCKFORD
DEPENDING ON HOW THE STRATUS EVOLVES IN /IT MAY REMAIN SOUTH OF
ROCKFORD/. THIS WILL BE THE NINTH DAY IN AT LEAST THE 50S THIS
METEOROLOGICAL WINTER AT ROCKFORD.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS THROUGH EARLY THIS EVENING.
* SWLY GUSTS TO 25KT DROPPING OFF LATE THIS AFTERNOON.
* SLIGHT CHANCE OF VIS DROPPING TO MVFR IN HZ/BR DURG EARLY
MORNING HOURS.
LENNING
//DISCUSSION...UPDATED 18Z...
GUSTY SWLY WINDS WILL CONTINUE INTO THE AFTERNOON AHEAD OF A WEAK
COLD FRONT MOVING INTO ERN IOWA. A PLUME OF LOW LEVEL MOISTURE
AHEAD OF THE FRONT HAS ALLOWED THE FORMATION OF A BKN STRATOCU
DECK EXTENDING FROM NRN MO TO NRN IL/IN. BASES OF THE CLOUD DECK
SHOULD STAY AT ARND 2.5KFT. AT ISSUANCE TIME...ORD/DPA/GYY WE JUST
TO THE NORTH OF THE BKN MVFR CIGS...AND ANTICIPATE THAT THE
COVERAGE SHOULD INCREASE TO BKN WITHIN THE HOUR OF ISSUANCE.
THE FRONT WILL STEADILY PUSH EWD THIS AFTERNOON...KEEPING WINDS
BRISK AND GUSTY UNTIL THE ASSOCIATED TROUGH CROSSES THE AREA LATE
THIS AFTERNOON AND EARLY THIS EVENING...RELAXING THE PRESSURE
GRADIENT OVER THE REGION. FOLLOWING THE FROPA...HIGH PRESSURE WILL
SPREAD ACROSS THE CENTRAL PLAINS AND INTO THE MIDWEST...ALLOWING
WINDS TO QUICKLY DROP OFF. DRIER AIR BEHIND THE FRONT SHOULD BRING
QUICKLY CLEARING SKIES. THE MAIN CONCERN FOR THE OVERNIGHT HOURS
WILL SHIFT TO VISIBILITY. SOME OF THE NUMERICAL GUIDANCE IS
INDICATING A CHANCE FOR VISBY REDUCTION TO MVFR AS SKIES CLEAR AND
WINDS DECREASE. THE ONE LIMITING FACTOR FOR VISIBILITY WILL BE LOW
LEVEL MOISTURE. THE AIRMASS BEHIND THE FRONT WILL BE RATHER DRY
AND IT IS UNCERTAIN THAT THERE WILL BE ENOUGH COOLING TO DROP THE
TEMPERATURE CLOSE ENOUGH TO THE DEWPOINT TO LEAD TO BR FORMATION.
SO...HAVE ONLY GONE WITH 6SM HZ FOR THE EARLY MORNING HOURS TO
BEGIN A TREND AND WILL MONITOR CONDITIONS CLOSELY TO SEE IF A
LOWER VISIBILITY FORECAST WILL BE WARRANTED FOR THE MORNING RUSH
HOURS. OTHERWISE...TOMORROW IS SHAPING UP TO BE A QUIET DAY WITH
NO OPERATIONALLY SIGNIFICANT WEATHER CONCERNS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE ON CEILING TRENDS. UPSTREAM OBS MAY BE
SOMEWHAT MORE OPTIMISTIC THAN TRENDS IN LATEST TAFS. THIS WOULD
RESULT IN SHORTER PERIOD OF MVFR.
* MEDIUM CONFIDENCE IN GUST SPEEDS AND TIME THAT THEY WOULD BE
DIMINISHING THIS AFTERNOON.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH FRIDAY...VFR
* SATURDAY AND SUNDAY...SLIGHT CHANCE OF RAIN OR SNOW
* MONDAY...VFR
SHEA
&&
.MARINE...
253 AM...LOW PRESSURE OVER THE UPPER MIDWEST WILL MOVE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND INTO QUEBEC WEDNESDAY MORNING.
A WARM FRONT EXTENDING ACROSS NORTH CENTRAL LAKE MICHIGAN THIS
MORNING WILL LIFT NORTH AS THE LOW APPROACHES AND THE GRADIENT
WILL ALSO CONTINUE TO TIGHTEN...FROM SOUTH TO NORTH AS THE LOW
APPROACHES. SOUTHERLY WINDS CONTINUE TO GUST AS HIGH AS 30 KTS
ACROSS FAR SOUTHERN LAKE MICHIGAN EARLY THIS MORNING AND EXPECT
THESE HIGHER WINDS/GUSTS TO CONTINUE NORTH DURING THE DAY. COULD
BE SOME HIGHER GUSTS TO 35 KT GALES BUT RATHER LOW CONFIDENCE
REGARDING HOW PREVAILING THESE MAY BECOME AND WILL NEED TO BE
MONITORED THROUGH THE MORNING.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS THE LAKE
EARLY THIS EVENING... SHIFTING WINDS WESTERLY WITH 30 KTS
POSSIBLE BEHIND THE FRONT... ESPECIALLY ACROSS THE NORTH HALF OR
SO OF THE LAKE. BROAD HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
TONIGHT INTO WEDNESDAY AND THEN ACROSS THE SOUTHERN GREAT LAKES
REGION WEDNESDAY AFTERNOON INTO THURSDAY. NEW LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS THURSDAY NIGHT INTO
FRIDAY AND THEN MOVE NORTHEAST ACROSS THE SOUTHERN LAKES THIS
WEEKEND. WHILE WINDS WILL SHIFT TO THE NORTHEAST AS THIS LOW
APPROACHES...THERE STILL REMAINS QUITE A BIT OF UNCERTAINTY
REGARDING THE TRACK...STRENGTHEN AND TIMING OF THIS SYSTEM. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1140 AM CST TUE JAN 31 2012
.DISCUSSION...
1054 AM CST
FOR MORNING UPDATE...
SOME MINOR TWEAKS TO GOING TEMP/SKY AND WX/POP GRIDS...THOUGH
FORECAST REMAINS LARGELY ON TRACK.
LOW PRESSURE POISED TO MOVE EAST ACROSS THE UPPER PENINSULA OF
MICHIGAN THIS AFTERNOON IN RESPONSE TO RATHER PRONOUNCED MID LEVEL
SHORT WAVE TROUGH PROPAGATING ACROSS THE UPPER MIDWEST. WARM SECTOR
SOUTH OF THE LOW ALREADY WARMING INTO THE LOW-MID 50S ACROSS THE CWA
AS OF 16Z. PERUSAL OF UPSTREAM SOUNDINGS AND LATEST MODEL LOW LEVEL
THERMAL PROGS CONTINUE TO SUGGEST MAX TEMPS ACROSS THE FORECAST AREA
POTENTIALLY RANGING FROM THE UPPER 50S NORTH TO THE MID 60S SOUTH...
HOWEVER GOES VISIBLE SATELLITE IMAGERY DOES DEPICT DEVELOPMENT OF
SOME STRATUS/STRATO CU ACROSS MO/IL IN REGION OF LOW LEVEL MOIST
ADVECTION AHEAD OF APPROACHING SHORT WAVE AND SURFACE TROUGH/COLD
FRONT. THIS CONTINUES TO MAKE FOR SOMEWHAT TRICKY AFTERNOON TEMP
FORECAST...WITH SOME VARIABLE COVERAGE IN OVERCAST CONDITIONS BUT AN
OVERALL INCREASE IN CLOUDINESS THROUGH THE AFTERNOON. HAVE TWEAKED
TEMPS UP JUST A LITTLE IN SOME SPOTS BASED ON TRENDS AND EXTRAPOLATED
NEAR TERM CLOUD TRENDS...BUT CANT ARGUE TOO MUCH WITH GOING
FORECAST.
IN ADDITION...POTENTIAL FOR DRIZZLE/SPRINKLES NOT LOOKING VERY
IMPRESSIVE AT THIS TIME...THOUGH GUIDANCE CONTINUES TO SUGGEST SOME
INCREASE IN POTENTIAL FOR SOME PATCHY LIGHT PRECIP ACROSS MAINLY THE
SOUTHEAST CWA VERY LATE THIS AFTERNOON/EVENING. HAVE ADJUSTED
LOCATION/COVERAGE ACCORDINGLY.
RATZER
//PREV DISCUSSION...
317 AM CST
THE ATTENTION ON THIS FORECAST WAS PRIMARILY DIRECTED TO
TEMPERATURES...WITH AN EMPHASIS ON TODAY AS NEAR RECORD TO RECORD
WARMTH IS ON PAR AGAIN FOR THE AREA. QUITE A DIFFERENCE FROM ONE
YEAR AGO TODAY...WHICH SAW THE AREA PREPARING FOR THE THIRD
LARGEST SNOWSTORM ON RECORD. AN ADDITIONAL CHALLENGE IN THE
FORECAST IS THAT BOTH WEDNESDAY AND THURSDAY ALSO ARE APPEARING
LIKELY TO BE WARMER THAN INITIALLY THOUGHT.
TEMPERATURES ARE STARTING NEARLY 30 DEGREES ABOVE NORMAL THIS
FINAL DAY OF JANUARY...WHICH IS FITTING FOR THIS MONTH THAT IS
AVERAGING 5 TO 6 DEGREES ABOVE NORMAL. SOUTHERLY WINDS AND
INCREASING LOW-LEVEL MOISTURE THROUGHOUT LAST NIGHT INTO THIS
MORNING HAVE AIDED THESE MILD READINGS. THE ANTICIPATED
STRATUS/STRATOCU IS DEVELOPING QUICKLY NORTHEAST FROM THE SOUTHERN
PLAINS/OZARKS EARLY THIS MORNING...LINING UP WELL WITH MODEL
DIAGNOSTIC SOLUTIONS OF MOISTURE TRANSPORT AND CONVERGENCE IN THE
LOW LEVELS /ROUGHLY 850-925MB/.
EVEN AHEAD OF THESE LOW CLOUDS...MODEL GUIDANCE CONTINUES TO SHOW
BOTH A TOO MOIST AND COOL BIAS IN THE LOW-LEVELS...SOME LIKELY DUE
TO FALSE SNOW COVER AND/OR TOO COLD OF GROUND COVER. JUST THE
31.00 GFS AND NAMELY THE NAM SOUNDINGS ACROSS THE AREA REVEALED
THIS BIAS ALMOST IMMEDIATELY AFTER THEIR INITIALIZATION HOURS. SO
HAVE GUIDED MORE ON ABSOLUTE MOISTURE VALUES AND SATURATION NEAR
THE TOP OF THE ADAPTED MIXED-LAYER LATER THIS MORNING /~4000 FT/
FOR CLOUD INDICATIONS. THE MOISTURE CONVERGENCE FORECAST FROM THE
RUC AND NAM LINE UP WELL FROM SOUTHEAST IA INTO NORTHERN IL AND
EXPECT THE CLOUDS TO EXPAND INTO THAT AREA DURING THE LATE
MORNING. RUC PARCEL TRAJECTORIES WOULD INDICATE NEAR A 12 PM
ARRIVAL IN CHICAGO BASED ON CURRENT PLACEMENT OF THE LOW
CLOUDS...BUT SOME LEAD SATURATION MAY CAUSE IT TO BE A LITTLE
QUICKER. THE STRATUS PLUME AND HOW QUICKLY IT MOVES IN WILL LIKELY
IMPACT TEMPERATURES A FEW DEGREES.
AS FOR THOSE TEMPERATURES TODAY...LOCAL ANALYSIS HERE HAS SHOWN
THAT BIAS-CORRECTED GUIDANCE IS WORKING VERY WELL IN THESE VERY
MILD STRETCHES THIS WINTER...PARTICULARLY THE GEM AND THE EC. HAVE
BLENDED OUR GOING FORECAST HEAVILY TOWARDS THESE SOLUTIONS...AND
EVEN ADJUSTED UP FROM THERE IN SOME AREAS. WHILE THE CLOUDS WILL
EXPAND IN...CONTINUED LOW-LEVEL WARM ADVECTION WILL LIKELY
SUPPORT INCREASING SURFACE TEMPERATURES INTO THE
AFTERNOON...ALBEIT AT A SLOWER RATE. SO HAVE SOME QUICK MORNING
WARMING FORECAST FROM THE HIGH STARTING POINT VALUES...AND THEN
GRADUAL INCREASE THIS AFTERNOON. THIS APPROACH YIELDS REMARKABLY
MILD UPPER 50S TO LOWER 60 DEGREE READINGS BEING LIKELY IN SEVERAL
AREAS. EVEN MID 60S COULD BE TOUCHED IN THE EASTERN HALF OF THE
AREA IF THE RATE OF WARMING AFTER THE CLOUDS ARRIVE IS HIGHER THAN
INDICATED. PLEASE SEE THE CLIMATE SECTION BELOW FOR RECORD
INFORMATION.
AS FOR PRECIPITATION CHANCES THIS AFTERNOON INTO TONIGHT...THE
DEPTH OF THE CLOUDS INCREASE QUICKLY LATE THIS AFTERNOON INTO THE
EVENING. MARGINAL SATURATED ISENTROPIC ASCENT AND CONVERGENCE
AHEAD OF A COLD FRONT MOVING THROUGH...MAY OFFER SPORADIC LIGHT
RAIN OR DRIZZLE IN THE SOUTHEAST HALF OF THE FORECAST AREA DURING
THE LATE AFTERNOON AND EVENING. THE LIGHT RAIN MAY ACTUALLY BE
MORE SHOWERY...BUT LIMITED FORCING WILL PREVENT ANYTHING
APPRECIABLE.
WEDNESDAY AND THURSDAY...WHILE LOW-LEVEL TEMPERATURES ARE FORECAST
TO COOL DURING THIS PERIOD...THEY ARE STILL ON THE WARMER THAN
NORMAL SIDE. THE LACK OF SNOW COVER TOO SHOULD AID IN THE WARMER
BIAS-CORRECTED GUIDANCE BEING MORE ON TRACK. CLOUDS ALSO LOOK
LIMITED...ALTHOUGH CONFIDENCE IS CURRENTLY LOW ON WEDNESDAY
MORNING WITH A SOMEWHAT LIMITED SURGE BEHIND THIS FRONT MEANING
LINGERING STRATUS IS POSSIBLE. IF NOT THOUGH...TEMPERATURES
GETTING TO 50 ON WEDNESDAY SEEM PROBABLE...AND THEN WELL INTO THE
40S ON THURSDAY. RIDGING SHOULD ALLOW FOR ONLY CIRRUS BY THURSDAY.
LATE THIS WEEK INTO THE WEEKEND...THE PROGRESSIVE WESTERLY PATTERN
IS EXPECTED TO SLOW DOWN WITH A CUT OFF LOW AND A GENERAL BLOCKING
PATTERN DEVELOPING TO OUR WEST. DETAILS HAVE VARIED
SIGNIFICANTLY...BUT A CLEAR TREND IN THE GUIDANCE IS SLOWER WITH
PROGRESSING FORCING FOR PRECIPITATION EAST INTO OUR AREA. GIVEN
THAT PATTERN...THAT SEEMS REASONABLE AND HAVE ADJUSTED THE BLENDED
GUIDANCE FORECAST THAT WAY. THE SLOWER 31.00 EC WAS FOLLOWED
CLOSELY FOR DETAILS. SOME FORM OF INVERTED TROUGH OR WEAK SURFACE
LOW IS LIKELY TO DEVELOP AS THE CLOSED UPPER CIRCULATION WORKS
EAST...AND SUCH A FEATURE WOULD ALSO NOT FAVOR PRECIP FAR TO ITS
EAST. SO ONLY HAVE SMALL CHANCES DURING THE WEEKEND...WITH
FORECAST SOUNDINGS AND GENERAL THICKNESSES SLIGHTLY MORE
SUPPORTIVE OF RAIN THAN SNOW IF PRECIP OCCURS. IT IS STILL
FAVORED THAT NO PRECIPITATION WILL OCCUR THIS WEEKEND...ESPECIALLY
IF THE EC SOUTHERN TRACK OF THE CLOSED LOW WERE TO COME TO
FRUITION.
&&
.CLIMATE...
THE RECORD HIGH TODAY FOR CHICAGO IS 65 IN 1989. THE HIGH
TEMPERATURE IS MOST LIKELY TO BE 3 TO 7 DEGREES SHY OF THIS...BUT
IT COULD END UP GETTING VERY CLOSE. THE GOING FORECAST IS FOR THIS
TO BE THE WARMEST DAY THIS METEOROLOGICAL WINTER SO FAR. THIS WILL
BE THE TENTH DAY IN AT LEAST THE 50S SINCE DECEMBER 1ST /BASICALLY
ONE DAY A WEEK THIS WINTER SO FAR/. AS FOR ROCKFORD THE RECORD
HIGH IS 63 ALSO IN 1989. THE HIGH TEMPERATURE IS EXPECTED TO FALL
SEVERAL DEGREES SHORT...BUT CONFIDENCE IS LOWER AT ROCKFORD
DEPENDING ON HOW THE STRATUS EVOLVES IN /IT MAY REMAIN SOUTH OF
ROCKFORD/. THIS WILL BE THE NINTH DAY IN AT LEAST THE 50S THIS
METEOROLOGICAL WINTER AT ROCKFORD.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CHANCE OF MVFR CIGS THROUGH EARLY THIS EVENING.
* SWLY WINDS GUSTING TO 25KT THROUGH MID-AFTERNOON.
* SLIGHT CHANCE OF VIS DROPPING TO MVFR IN HZ/BR DURG EARLY
MORNING HOURS.
KREIN
//DISCUSSION...UPDATED 18Z...
GUSTY SWLY WINDS WILL CONTINUE INTO THE AFTERNOON AHEAD OF A WEAK
COLD FRONT MOVING INTO ERN IOWA. A PLUME OF LOW LEVEL MOISTURE
AHEAD OF THE FRONT HAS ALLOWED THE FORMATION OF A BKN STRATOCU
DECK EXTENDING FROM NRN MO TO NRN IL/IN. BASES OF THE CLOUD DECK
SHOULD STAY AT ARND 2.5KFT. AT ISSUANCE TIME...ORD/DPA/GYY WE JUST
TO THE NORTH OF THE BKN MVFR CIGS...AND ANTICIPATE THAT THE
COVERAGE SHOULD INCREASE TO BKN WITHIN THE HOUR OF ISSUANCE.
THE FRONT WILL STEADILY PUSH EWD THIS AFTERNOON...KEEPING WINDS
BRISK AND GUSTY UNTIL THE ASSOCIATED TROUGH CROSSES THE AREA LATE
THIS AFTERNOON AND EARLY THIS EVENING...RELAXING THE PRESSURE
GRADIENT OVER THE REGION. FOLLOWING THE FROPA...HIGH PRESSURE WILL
SPREAD ACROSS THE CENTRAL PLAINS AND INTO THE MIDWEST...ALLOWING
WINDS TO QUICKLY DROP OFF. DRIER AIR BEHIND THE FRONT SHOULD BRING
QUICKLY CLEARING SKIES. THE MAIN CONCERN FOR THE OVERNIGHT HOURS
WILL SHIFT TO VISIBILITY. SOME OF THE NUMERICAL GUIDANCE IS
INDICATING A CHANCE FOR VISBY REDUCTION TO MVFR AS SKIES CLEAR AND
WINDS DECREASE. THE ONE LIMITING FACTOR FOR VISIBILITY WILL BE LOW
LEVEL MOISTURE. THE AIRMASS BEHIND THE FRONT WILL BE RATHER DRY
AND IT IS UNCERTAIN THAT THERE WILL BE ENOUGH COOLING TO DROP THE
TEMPERATURE CLOSE ENOUGH TO THE DEWPOINT TO LEAD TO BR FORMATION.
SO...HAVE ONLY GONE WITH 6SM HZ FOR THE EARLY MORNING HOURS TO
BEGIN A TREND AND WILL MONITOR CONDITIONS CLOSELY TO SEE IF A
LOWER VISIBILITY FORECAST WILL BE WARRANTED FOR THE MORNING RUSH
HOURS. OTHERWISE...TOMORROW IS SHAPING UP TO BE A QUIET DAY WITH
NO OPERATIONALLY SIGNIFICANT WEATHER CONCERNS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MODERATE CONFIDENCE IN CEILING AND VISIBILITY TRENDS.
* MODERATE TO HIGH CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH FRIDAY...VFR
* SATURDAY AND SUNDAY...SLIGHT CHANCE OF RAIN OR SNOW
* MONDAY...VFR
SHEA
&&
.MARINE...
253 AM...LOW PRESSURE OVER THE UPPER MIDWEST WILL MOVE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND INTO QUEBEC WEDNESDAY MORNING.
A WARM FRONT EXTENDING ACROSS NORTH CENTRAL LAKE MICHIGAN THIS
MORNING WILL LIFT NORTH AS THE LOW APPROACHES AND THE GRADIENT
WILL ALSO CONTINUE TO TIGHTEN...FROM SOUTH TO NORTH AS THE LOW
APPROACHES. SOUTHERLY WINDS CONTINUE TO GUST AS HIGH AS 30 KTS
ACROSS FAR SOUTHERN LAKE MICHIGAN EARLY THIS MORNING AND EXPECT
THESE HIGHER WINDS/GUSTS TO CONTINUE NORTH DURING THE DAY. COULD
BE SOME HIGHER GUSTS TO 35 KT GALES BUT RATHER LOW CONFIDENCE
REGARDING HOW PREVAILING THESE MAY BECOME AND WILL NEED TO BE
MONITORED THROUGH THE MORNING.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS THE LAKE
EARLY THIS EVENING... SHIFTING WINDS WESTERLY WITH 30 KTS
POSSIBLE BEHIND THE FRONT... ESPECIALLY ACROSS THE NORTH HALF OR
SO OF THE LAKE. BROAD HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
TONIGHT INTO WEDNESDAY AND THEN ACROSS THE SOUTHERN GREAT LAKES
REGION WEDNESDAY AFTERNOON INTO THURSDAY. NEW LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS THURSDAY NIGHT INTO
FRIDAY AND THEN MOVE NORTHEAST ACROSS THE SOUTHERN LAKES THIS
WEEKEND. WHILE WINDS WILL SHIFT TO THE NORTHEAST AS THIS LOW
APPROACHES...THERE STILL REMAINS QUITE A BIT OF UNCERTAINTY
REGARDING THE TRACK...STRENGTHEN AND TIMING OF THIS SYSTEM. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1055 AM CST TUE JAN 31 2012
.DISCUSSION...
1054 AM CST
FOR MORNING UPDATE...
SOME MINOR TWEAKS TO GOING TEMP/SKY AND WX/POP GRIDS...THOUGH
FORECAST REMAINS LARGELY ON TRACK.
LOW PRESSURE POISED TO MOVE EAST ACROSS THE UPPER PENINSULA OF
MICHIGAN THIS AFTERNOON IN RESPONSE TO RATHER PRONOUNCED MID LEVEL
SHORT WAVE TROUGH PROPAGATING ACROSS THE UPPER MIDWEST. WARM SECTOR
SOUTH OF THE LOW ALREADY WARMING INTO THE LOW-MID 50S ACROSS THE CWA
AS OF 16Z. PERUSAL OF UPSTREAM SOUNDINGS AND LATEST MODEL LOW LEVEL
THERMAL PROGS CONTINUE TO SUGGEST MAX TEMPS ACROSS THE FORECAST AREA
POTENTIALLY RANGING FROM THE UPPER 50S NORTH TO THE MID 60S SOUTH...
HOWEVER GOES VISIBLE SATELLITE IMAGERY DOES DEPICT DEVELOPMENT OF
SOME STRATUS/STRATO CU ACROSS MO/IL IN REGION OF LOW LEVEL MOIST
ADVECTION AHEAD OF APPROACHING SHORT WAVE AND SURFACE TROUGH/COLD
FRONT. THIS CONTINUES TO MAKE FOR SOMEWHAT TRICKY AFTERNOON TEMP
FORECAST...WITH SOME VARIABLE COVERAGE IN OVERCAST CONDITIONS BUT AN
OVERALL INCREASE IN CLOUDINESS THROUGH THE AFTERNOON. HAVE TWEAKED
TEMPS UP JUST A LITTLE IN SOME SPOTS BASED ON TRENDS AND EXTRAPOLATED
NEAR TERM CLOUD TRENDS...BUT CANT ARGUE TOO MUCH WITH GOING
FORECAST.
IN ADDITION...POTENTIAL FOR DRIZZLE/SPRINKLES NOT LOOKING VERY
IMPRESSIVE AT THIS TIME...THOUGH GUIDANCE CONTINUES TO SUGGEST SOME
INCREASE IN POTENTIAL FOR SOME PATCHY LIGHT PRECIP ACROSS MAINLY THE
SOUTHEAST CWA VERY LATE THIS AFTERNOON/EVENING. HAVE ADJUSTED
LOCATION/COVERAGE ACCORDINGLY.
RATZER
&&
.PREV DISCUSSION...
317 AM CST
THE ATTENTION ON THIS FORECAST WAS PRIMARILY DIRECTED TO
TEMPERATURES...WITH AN EMPHASIS ON TODAY AS NEAR RECORD TO RECORD
WARMTH IS ON PAR AGAIN FOR THE AREA. QUITE A DIFFERENCE FROM ONE
YEAR AGO TODAY...WHICH SAW THE AREA PREPARING FOR THE THIRD
LARGEST SNOWSTORM ON RECORD. AN ADDITIONAL CHALLENGE IN THE
FORECAST IS THAT BOTH WEDNESDAY AND THURSDAY ALSO ARE APPEARING
LIKELY TO BE WARMER THAN INITIALLY THOUGHT.
TEMPERATURES ARE STARTING NEARLY 30 DEGREES ABOVE NORMAL THIS
FINAL DAY OF JANUARY...WHICH IS FITTING FOR THIS MONTH THAT IS
AVERAGING 5 TO 6 DEGREES ABOVE NORMAL. SOUTHERLY WINDS AND
INCREASING LOW-LEVEL MOISTURE THROUGHOUT LAST NIGHT INTO THIS
MORNING HAVE AIDED THESE MILD READINGS. THE ANTICIPATED
STRATUS/STRATOCU IS DEVELOPING QUICKLY NORTHEAST FROM THE SOUTHERN
PLAINS/OZARKS EARLY THIS MORNING...LINING UP WELL WITH MODEL
DIAGNOSTIC SOLUTIONS OF MOISTURE TRANSPORT AND CONVERGENCE IN THE
LOW LEVELS /ROUGHLY 850-925MB/.
EVEN AHEAD OF THESE LOW CLOUDS...MODEL GUIDANCE CONTINUES TO SHOW
BOTH A TOO MOIST AND COOL BIAS IN THE LOW-LEVELS...SOME LIKELY DUE
TO FALSE SNOW COVER AND/OR TOO COLD OF GROUND COVER. JUST THE
31.00 GFS AND NAMELY THE NAM SOUNDINGS ACROSS THE AREA REVEALED
THIS BIAS ALMOST IMMEDIATELY AFTER THEIR INITIALIZATION HOURS. SO
HAVE GUIDED MORE ON ABSOLUTE MOISTURE VALUES AND SATURATION NEAR
THE TOP OF THE ADAPTED MIXED-LAYER LATER THIS MORNING /~4000 FT/
FOR CLOUD INDICATIONS. THE MOISTURE CONVERGENCE FORECAST FROM THE
RUC AND NAM LINE UP WELL FROM SOUTHEAST IA INTO NORTHERN IL AND
EXPECT THE CLOUDS TO EXPAND INTO THAT AREA DURING THE LATE
MORNING. RUC PARCEL TRAJECTORIES WOULD INDICATE NEAR A 12 PM
ARRIVAL IN CHICAGO BASED ON CURRENT PLACEMENT OF THE LOW
CLOUDS...BUT SOME LEAD SATURATION MAY CAUSE IT TO BE A LITTLE
QUICKER. THE STRATUS PLUME AND HOW QUICKLY IT MOVES IN WILL LIKELY
IMPACT TEMPERATURES A FEW DEGREES.
AS FOR THOSE TEMPERATURES TODAY...LOCAL ANALYSIS HERE HAS SHOWN
THAT BIAS-CORRECTED GUIDANCE IS WORKING VERY WELL IN THESE VERY
MILD STRETCHES THIS WINTER...PARTICULARLY THE GEM AND THE EC. HAVE
BLENDED OUR GOING FORECAST HEAVILY TOWARDS THESE SOLUTIONS...AND
EVEN ADJUSTED UP FROM THERE IN SOME AREAS. WHILE THE CLOUDS WILL
EXPAND IN...CONTINUED LOW-LEVEL WARM ADVECTION WILL LIKELY
SUPPORT INCREASING SURFACE TEMPERATURES INTO THE
AFTERNOON...ALBEIT AT A SLOWER RATE. SO HAVE SOME QUICK MORNING
WARMING FORECAST FROM THE HIGH STARTING POINT VALUES...AND THEN
GRADUAL INCREASE THIS AFTERNOON. THIS APPROACH YIELDS REMARKABLY
MILD UPPER 50S TO LOWER 60 DEGREE READINGS BEING LIKELY IN SEVERAL
AREAS. EVEN MID 60S COULD BE TOUCHED IN THE EASTERN HALF OF THE
AREA IF THE RATE OF WARMING AFTER THE CLOUDS ARRIVE IS HIGHER THAN
INDICATED. PLEASE SEE THE CLIMATE SECTION BELOW FOR RECORD
INFORMATION.
AS FOR PRECIPITATION CHANCES THIS AFTERNOON INTO TONIGHT...THE
DEPTH OF THE CLOUDS INCREASE QUICKLY LATE THIS AFTERNOON INTO THE
EVENING. MARGINAL SATURATED ISENTROPIC ASCENT AND CONVERGENCE
AHEAD OF A COLD FRONT MOVING THROUGH...MAY OFFER SPORADIC LIGHT
RAIN OR DRIZZLE IN THE SOUTHEAST HALF OF THE FORECAST AREA DURING
THE LATE AFTERNOON AND EVENING. THE LIGHT RAIN MAY ACTUALLY BE
MORE SHOWERY...BUT LIMITED FORCING WILL PREVENT ANYTHING
APPRECIABLE.
WEDNESDAY AND THURSDAY...WHILE LOW-LEVEL TEMPERATURES ARE FORECAST
TO COOL DURING THIS PERIOD...THEY ARE STILL ON THE WARMER THAN
NORMAL SIDE. THE LACK OF SNOW COVER TOO SHOULD AID IN THE WARMER
BIAS-CORRECTED GUIDANCE BEING MORE ON TRACK. CLOUDS ALSO LOOK
LIMITED...ALTHOUGH CONFIDENCE IS CURRENTLY LOW ON WEDNESDAY
MORNING WITH A SOMEWHAT LIMITED SURGE BEHIND THIS FRONT MEANING
LINGERING STRATUS IS POSSIBLE. IF NOT THOUGH...TEMPERATURES
GETTING TO 50 ON WEDNESDAY SEEM PROBABLE...AND THEN WELL INTO THE
40S ON THURSDAY. RIDGING SHOULD ALLOW FOR ONLY CIRRUS BY THURSDAY.
LATE THIS WEEK INTO THE WEEKEND...THE PROGRESSIVE WESTERLY PATTERN
IS EXPECTED TO SLOW DOWN WITH A CUT OFF LOW AND A GENERAL BLOCKING
PATTERN DEVELOPING TO OUR WEST. DETAILS HAVE VARIED
SIGNIFICANTLY...BUT A CLEAR TREND IN THE GUIDANCE IS SLOWER WITH
PROGRESSING FORCING FOR PRECIPITATION EAST INTO OUR AREA. GIVEN
THAT PATTERN...THAT SEEMS REASONABLE AND HAVE ADJUSTED THE BLENDED
GUIDANCE FORECAST THAT WAY. THE SLOWER 31.00 EC WAS FOLLOWED
CLOSELY FOR DETAILS. SOME FORM OF INVERTED TROUGH OR WEAK SURFACE
LOW IS LIKELY TO DEVELOP AS THE CLOSED UPPER CIRCULATION WORKS
EAST...AND SUCH A FEATURE WOULD ALSO NOT FAVOR PRECIP FAR TO ITS
EAST. SO ONLY HAVE SMALL CHANCES DURING THE WEEKEND...WITH
FORECAST SOUNDINGS AND GENERAL THICKNESSES SLIGHTLY MORE
SUPPORTIVE OF RAIN THAN SNOW IF PRECIP OCCURS. IT IS STILL
FAVORED THAT NO PRECIPITATION WILL OCCUR THIS WEEKEND...ESPECIALLY
IF THE EC SOUTHERN TRACK OF THE CLOSED LOW WERE TO COME TO
FRUITION.
&&
.CLIMATE...
THE RECORD HIGH TODAY FOR CHICAGO IS 65 IN 1989. THE HIGH
TEMPERATURE IS MOST LIKELY TO BE 3 TO 7 DEGREES SHY OF THIS...BUT
IT COULD END UP GETTING VERY CLOSE. THE GOING FORECAST IS FOR THIS
TO BE THE WARMEST DAY THIS METEOROLOGICAL WINTER SO FAR. THIS WILL
BE THE TENTH DAY IN AT LEAST THE 50S SINCE DECEMBER 1ST /BASICALLY
ONE DAY A WEEK THIS WINTER SO FAR/. AS FOR ROCKFORD THE RECORD
HIGH IS 63 ALSO IN 1989. THE HIGH TEMPERATURE IS EXPECTED TO FALL
SEVERAL DEGREES SHORT...BUT CONFIDENCE IS LOWER AT ROCKFORD
DEPENDING ON HOW THE STRATUS EVOLVES IN /IT MAY REMAIN SOUTH OF
ROCKFORD/. THIS WILL BE THE NINTH DAY IN AT LEAST THE 50S THIS
METEOROLOGICAL WINTER AT ROCKFORD.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SSWLY WINDS GUSTING TO 25KT VEERING SWLY THIS AFTERNOON.
* ANTICIPATED MVFR CIGS THIS AFTERNOON LOOKING LESS LIKELY.
KREIN
//DISCUSSION...UPDATED 12Z...
MORNING FORECAST HAS A FEW CHALLENGES. THE FIRST WILL BE WITH LLWS
LIKELIHOOD THROUGH THE EARLY MORNING HOURS. ORD/MDW 1 MINUTE ASOS
DATA HAS BEEN HAVING ON AND OFF GUSTS IN THE 17-20KT RANGE
OVERNIGHT...WITH SUSTAINED 10-15KT WINDS. 12Z SOUNDINGS FROM ILX
AND DVN MAINTAINED A GENERAL 55KT WIND OUT OF ROUGHLY 240 AT 1.9
KFT. EXPECT THE THREAT TO CONTINUE INTO THROUGH ROUGHLY 15Z OR SO
WHEN HIGHER SURFACE GUSTS BEGIN AND AS THE HIGHEST LOWER LEVEL
WINDS SHIFT EAST. A FRONT WILL MOVE ACROSS THE AIRSPACE LATE THIS
EVENING SHIFTING WINDS FROM WEST TO NORTHWEST.
THE SECOND CHALLENGE WILL BE WITH CLOUD COVER. CONTINUED RUN AFTER
RUN OF ALL FORECAST GUIDANCE HAS BEEN OVERDOING THE LOWEST LEVEL
RH FIELDS...AND BRINGING IN HIGH IFR TO LOW MVFR STRATUS ACROSS
THE EASTERN TERMINALS INTO THE LATE MORNING HOURS. STILL BELIEVE
THAT WE WILL SEE A HIGHER END MVFR TO LOWER END VFR CIG SWING
ACROSS THE REGION BEYOND THE 19Z HOUR TODAY. A MANUAL TIME OF
ARRIVAL OF THE PRESENT FIELD ACROSS NORTHWEST MISSOURI WOULD BRING
THE DECK INTO ORD BY 17Z...AND MET/MAV WOULD LEAD YOU TO BELIEVE
THAT THE TERMINALS WOULD SEE CIGS BELOW 015. DISCOUNTING THAT FOR
A FEW REASONS. FIRST IS DUE TO HIGHER RH BIAS THAT HAS BEEN
ONGOING...AND ALSO FEEL WITH DAYTIME MIXING...CIGS SHOULD BEGIN TO
RAISE. ALSO...H92-95 FLOW WILL TURN A LITTLE MORE WESTERLY THIS
MORNING...AND THE MAIN MOISTURE AXIS SHOULD TURN A LITTLE MORE
EASTERLY. WITH THE BULK OF THE MOISTURE STAYING TO THE SOUTH OF
ORD/MDW...FEEL THAT THE TERMINALS SHOULD NOT SEE ANY -DZ OUTSIDE
OF GYY...WHERE A LATE EVENING TIMING LOOKS BEST AT THIS
POINT...BUT CONFIDENCE REMAINS LOW ENOUGH THAT WILL ONLY CARRY A
PROB30 FOR LIGHT RAIN AT THIS POINT.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MODERATE CONFIDENCE THAT CIGS WILL REMAIN VFR THROUGH EARLY
THIS EVENING UNTIL FROPA...LOWER CONFIDENCE IN CHANCES FOR MVFR
CIGS FOR A SHORT TIME AFTER FROPA.
* LOW CONFIDENCE IN -DZ POTENTIAL IN THE LATE AFTERNOON.
* MODERATE-HIGH CONFIDENCE ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH FRIDAY...VFR
* SATURDAY AND SUNDAY...SLIGHT CHANCE OF RAIN OR SNOW
* MONDAY...VFR
SHEA
&&
.MARINE...
253 AM...LOW PRESSURE OVER THE UPPER MIDWEST WILL MOVE ACROSS
LAKE SUPERIOR THIS AFTERNOON AND INTO QUEBEC WEDNESDAY MORNING.
A WARM FRONT EXTENDING ACROSS NORTH CENTRAL LAKE MICHIGAN THIS
MORNING WILL LIFT NORTH AS THE LOW APPROACHES AND THE GRADIENT
WILL ALSO CONTINUE TO TIGHTEN...FROM SOUTH TO NORTH AS THE LOW
APPROACHES. SOUTHERLY WINDS CONTINUE TO GUST AS HIGH AS 30 KTS
ACROSS FAR SOUTHERN LAKE MICHIGAN EARLY THIS MORNING AND EXPECT
THESE HIGHER WINDS/GUSTS TO CONTINUE NORTH DURING THE DAY. COULD
BE SOME HIGHER GUSTS TO 35 KT GALES BUT RATHER LOW CONFIDENCE
REGARDING HOW PREVAILING THESE MAY BECOME AND WILL NEED TO BE
MONITORED THROUGH THE MORNING.
A TRAILING COLD FRONT FROM THIS LOW WILL MOVE ACROSS THE LAKE
EARLY THIS EVENING... SHIFTING WINDS WESTERLY WITH 30 KTS
POSSIBLE BEHIND THE FRONT... ESPECIALLY ACROSS THE NORTH HALF OR
SO OF THE LAKE. BROAD HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
TONIGHT INTO WEDNESDAY AND THEN ACROSS THE SOUTHERN GREAT LAKES
REGION WEDNESDAY AFTERNOON INTO THURSDAY. NEW LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS THURSDAY NIGHT INTO
FRIDAY AND THEN MOVE NORTHEAST ACROSS THE SOUTHERN LAKES THIS
WEEKEND. WHILE WINDS WILL SHIFT TO THE NORTHEAST AS THIS LOW
APPROACHES...THERE STILL REMAINS QUITE A BIT OF UNCERTAINTY
REGARDING THE TRACK...STRENGTHEN AND TIMING OF THIS SYSTEM. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
542 PM EST TUE JAN 31 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY
LATE TONIGHT AND WEDNESDAY, WILL BRING SHOWERS. TEMPERATURES
BEHIND THE FRONT WILL BE COOLER BUT STILL ABOVE NORMAL.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
ONLY CHANGE TO FORECAST WAS TO SPEED UP ARRIVAL OF RAIN SHOWERS
LATER THIS EVENING AS 18Z MODEL RUNS DEVELOP SHOWERS EARLIER ACROSS
OHIO TONIGHT AND RADAR RETURNS SHOW DEVELOPMENT AT THIS HOUR
ALONG THE OHIO RIVER. NO OTHER SIGNIFICANT CHANGES AND PREVIOUS
DISCUSSION FOLLOWS...
RECENT NAM AND SREF MODEL OUTPUT SHOW THE COLD FRONT WILL BE
PRECEDED BY TWO BANDS OF SHOWERS, WHICH WILL MOVE THROUGH THE
UPPER OHIO VALLEY LATE TONIGHT AND WEDNESDAY MORNING. THERE CAN BE
LINGERING SHOWERS ACROSS THE WV- MD-PA MOUNTAINS INTO LATE
AFTERNOON.
BECAUSE OF THE MILD PREFRONTAL SOUTHWEST WINDS, FORECASTED
TEMPERATURES, USING RECENT GFS LAMP AND MOS, TO BE AS MUCH AS 20-25
DEGREES WARMER THAN NORMAL TONIGHT.
WESTERLY JETSTREAM ALOFT WILL MINIMIZE STRENGTH OF POST FRONTAL
COOLING WEDNESDAY. HENCE, AS SUGGESTED BY GFS AND NAM MOS, EXPECT
HIGHS WEDNESDAY AFTERNOON TO STILL BE 15-20 DEGREES WARMER THAN
NORMAL.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW A WESTERLY JETSTREAM
ALOFT THIS PERIOD, WHICH WILL RESTRICT THE STRENGTH OF ANY COLD
AIR INTRUSION. A WEAK TROUGH PASSING THROUGH THE UPPER OHIO
VALLEY THURSDAY SHOULD ENSURE MOSTLY CLOUDY SKIES THROUGH THE
PERIOD. HOWEVER, EXPECT LITTLE IF ANY PRECIPITATION, EVEN ACROSS
THE WINDWARD MOUNTAIN SLOPES.
HAVE FORECASTED TEMPERATURES TO BE COOLER THAN WEDNESDAY, BUT
STILL CAN BE 10 DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MORE SO THAN THE LAST FEW DAYS...THE DETERMINISTIC MODELS AND
ENSEMBLE MEANS HAVE BEGUN TO SUGGEST VERY SIMILAR SCENARIOS IN
EJECTION OF THE 500HPA LOW THROUGH THE CENTRAL U.S AND TOWARDS THE
REGION. THE MODELS THAT YESTERDAY SUGGESTED A NEARLY STATIONARY
CUTOFF LOW OVER THE EASTERN ROCKIES...HAVE SPED UP TO A CLOSER
GEFS/GFS SOLUTION THAT HAS BE PREVALENT FOR A FEW DAYS. THE SPLIT
FLOW CONTINUES TO MAKE SOME OF THE FORECAST VARIABLES DIFFICULT
HOWEVER...ESPECIALLY IN REGARDS TO TIMING AND LOCATION OF THE
SURFACE LOW AS IT CROSSES THE OHIO VALLEY.
CONTINUED TO FOLLOW CLOSELY TO HPC GUIDANCE, BUT TOOK THE MOST RECENT
RUNS OF THE GEFS...GFS...AND ECMWF INTO ACCOUNT. KEPT CHANCE POPS IN
THE FORECAST SATURDAY THROUGH SUNDAY AS THE LOW CROSSES. USED A
BLEND OF HPC AND TO A GREATER EXTENT MEX GUIDANCE THROUGH TUESDAY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL CONTINUE THIS EVE BUT WL BE MARRED BY
INCREASING...AND LOWERING MID LVL CLDINESS AS STRNG...WARM...MOIST
ADVCTN CONTS IN ADVN OF STRNG LOW PRES MOVG ACRS THE NRN LAKES.
-SHRA ACTIVITY WL ALSO BE ON THE INCRS...BUT RESTRICTIONS ARE NOT
ANTICIPATED UNTIL THE LLVLS GET CLOSER TO SATURATION LTR TNGT. MVFR
IS CONFIDENTLY FORECAST IN THE POST MIDNGT PD...AND SHOULD DOMINATE
AREA TAFS UNTIL FRONTAL PASSAGE LTR ON WEDNESDAY MRNG.
ALSO OF CONCERN IS THE INCREASING INDICATIONS OF MORE LLWS AS
PROGGED VIA THE LATEST NAM AND RUC MDL SOUNDINGS. HAVE THUS ADDED
THIS POTENTIAL FOR THE EVE TAF ISSUANCES WITH NR 50 KTS FORECAST
ABOVE THE INVERSION LEVEL...I.E. ARND 2 KFT...AGAIN UNTIL FRONTAL
PASSAGE LTR ON WED MRNG.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
LATEST DETERMINISTIC MDL SOLNS INDICATE THAT LOW PRES MOVING ALNG
FRONTAL BOUNDARY SHOULD PASS SUFFICIENTLY SOUTH OF UPR OH VALLEY
TERMINALS TO PRECLUDE WIDESPREAD RESTRICTIONS ON WED NGT. SFC WND
WL SHIFT TO THE NW IN THE WAKE OF THAT SYS ON THURSDAY WITH COLD
ADVCTN SPAWNING SOME LAKE/UPSLOPE ENHANCED STRATOCUMULUS. VFR
CONDITIONS ARE EXPECTED TO RTN FRIDAY...BUT ANOTHER LOW MAY DEGRADE
CONDTIONS AGAIN FOR THE WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1135 AM EST TUE JAN 31 2012
UPDATED FOR 18Z AVIATION DISCUSSION
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL FLOW ACROSS THE
NRN CONUS WITH A SHORTWAVE FROM NW MN INTO CNTRL SD. AT THE SFC...A
LOW PRES WAS LOCATED OVER NW MN WITH A WARM FRONT FROM CNTRL MN INTO
SRN WI. RADAR INDICATED PATCHY RETURNS OVER LAKE SUPERIOR AND WRN
UPPER MI SUPPORTED BY ISENTROPIC LIFT NORTH OF THE WARM FRONT.
HOWEVER...LITTLE IF ANY WAS REACHING THE GROUND AS OBS INDICATED
MAINLY JUST MID CLOUDS WITH NO PCPN.
&&
.SHORT TERM...TODAY AND TONIGHT
TODAY...EXPECT THE BEST CHANCE OF MEASURABLE PCPN TO REMAIN NORTH
OF THE CWA THIS MORNING WHERE THE GREATEST LIFT (285-295K LAYER) AND
DEEPER SATURATION OCCURS. OTHERWISE...A SUBSTANTIAL 925-750 MB DRY
LAYER WILL LIMIT ANY CHANCE OF RAIN/SNOW OVER UPPER MI. THERE MAY
STILL BE ENOUGH LOW LEVEL MOISTURE OVER THE NORTH HALF OF THE CWA FOR
SOME PATCHY -FZDZ...ESPECIALLY WHERE SRLY UPSLOPE FLOW PREVAILS. AS
THE SHORTWAVE MOVES THROUGH THIS AFTERNOON A PERIOD OF 700-500 MB
FGEN MAY PRODUCE ADDITIONAL LIFT BUT IS NOT EXPECTED TO BE STRONG
ENOUGH TO OVERCOME THE DRY LAYER BENEATH THE MID CLOUDS. EXPECT CLOUD
COVER TO BE THICK ENOUGH TO LIMIT MAX READINGS TO THE MID AND UPPER
30S DESPITE 900 MB TEMPS TO AROUND 5C.
TONIGHT...CAA IN THE WAKE OF THE SFC LOW DROPPING 850 MB TEMPS TO
NEAR -7C WITH INCREASING WNW WINDS MAY BE ENOUGH TO SUPPORT SOME
LIGHT LAKE ENHANCED PCPN INTO WRN UPPER MI DURING THE EVENING AND
FOR LOCATIONS EAST OF MARQUETTE OVERNIGHT. SINCE TEMPS IN THE CLOUD
LAYER (DOWN TO -7C TO -10C) WILL ONLY BE MARGINAL FOR ICE
CRYSTALS...-FZDZ POTENTIAL WILL CONTINUE.
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE WILL DOMINATE MUCH OF THIS PERIOD...WITH ONLY A
SLIGHT CHANCE OF OFF AND ON PRECIPITATION. WEATHER TYPE WILL REMAIN
TRICKY WITH AFTERNOON HIGH TEMPS IN THE 30S...LOWS MAINLY IN THE
20S...AND LOW LEVEL MOISTURE STUCK BELOW A STRONG INVERSION.
DRIZZLE OR FREEZING DRIZZLE WILL AGAIN BE A CONCERN TO START US OFF
ON WEDNESDAY. WHILE THE BULK OF MOISTURE WILL EXIT WITH THE SFC LOW
OVER FAR SE ONTARIO/S QUEBEC BY 12Z WEDNESDAY...A SFC TROUGH WILL
REMAIN THROUGH THE KEWEENAW PENINSULA/ISLE ROYALE AREA. LINGERING
LOW LEVEL MOISTURE UNDER NW FLOW WILL BE A CONCERN. THIS TROUGH WILL
SLOWLY ERODE WEST TO EAST THROUGH 00Z THURSDAY AS A RIDGE SLIDES IN.
ALTHOUGH LOW LEVEL MOISTURE REMAINS WEDNESDAY NIGHT /WITH THE
SHORTWAVE SLIDING ACROSS THE CWA/...IT DID NOT SEEM LIKE ENOUGH TO
WARRANT THE LOW POPS. ADDED FLURRIES INSTEAD...AFTER MIDNIGHT TO THE
KEWEENAW PENINSULA AND EAST OF MUNISING NEAR LAKE SUPERIOR WHEN SFC
WINDS BECOME MORE WNW.
THURSDAY NIGHT THROUGH MONDAY...
FORECAST MODELS DIVERGE SIGNIFICANTLY TOWARD THE END OF THE WORK
WEEK...PARTICULARLY WITH THE HANDLING OF LOW PRESSURE TO OUR SOUTH.
THE RESULT IS LOWER CONFIDENCE IN THE ONGOING FORECAST FROM FRIDAY
THROUGH MONDAY. THE 30/18Z GFS IS BACKED UP BY THE 30/12Z CANADIAN
AND TO A MUCH LESSER EXTENT THE DGEX. THEY SUPPORT THE SFC LOW
ORGANIZING OUT OF THE 4 CORNERS REGION THURSDAY...SLIDING OVER KS
FRIDAY NIGHT...IA SATURDAY NIGHT...AND SOUTHERN WI BY SUNDAY MORNING.
STRONG HIGH PRESSURE OVER S ONTARIO/QUEBEC AND LAKE SUPERIOR WILL
ACT TO KEEP MAINLY DRY AIR IN PLACE OVER OUR REGION THROUGH AT LEAST
SATURDAY.
WITH ALL THE DIFFERENCES BETWEEN THE ECMWF AND THE OVERALL
CONSENSUS...THEY DO MERGE IN ON HAVING THE SFC LOW JUST SE OF THE
CWA BY 00Z MONDAY...WITH THE GFS BEING MORE PROGRESSIVE THEREAFTER
AS THE SOUTHERN LOW NEARLY MERGES WITH THE NORTHERN STREAM LOW OVER
HUDSON BAY.
JUST HOW MUCH COLD AIR FILTERS IN BEHIND THE LOW IS A QUESTION. THE
30/18Z GFS SUGGESTS 850MB TEMPS WARMING TO AROUND -1C 00Z SUNDAY
PRIOR TO ANY PRECIP...WITH -2 TO -6C AIR NEAR THE LOW ITSELF. THE
COOL NNW FLOW BEHIND THE SYSTEM SUNDAY NIGHT INTO MONDAY BEING LESS
THAN IMPRESSIVE WITH -6C ABOUT THE COLDEST AIR AVAILABLE. THE COLDER
AIR /BELOW -12C LOOKS/ TO REMAIN OVER N MANITOBA/ONTARIO THROUGH
MONDAY. RUN TO RUN CONSISTENCY WITH THE GFS IS ALSO A BIT OF AN
ISSUE...AS THE 12Z GFS DID MERGE WITH THE NORTHERN STREAM A BIT
EARLIER RESULTING IN COLDER AIR OF -12C TO -14C BY MONDAY ACROSS THE
NW COUNTIES.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
CONFIDENCE IS LOW WITH THIS FORECAST AS LOW CLOUDS THAT HAD CLEARED
OUT EARLY THIS MORNING CAME BACK WITH FOG AT KSAW AND KCMX. WITH A
LOW PRESSURE SYSTEM AND WARM FRONT NEAR THE AREA EARLY THIS
AFTERNOON...THIS WILL CONTINUE TO BE A TRICKY FORECAST. WRAPAROUND
SECTION OF THE STORM SHOULD COME INTO THE AREA THIS AFTERNOON AND
SHOULD LEAD TO VFR CONDITIONS GOING BACK TO MVFR AT KIWD AND KCMX.
SLOW IMPROVEMENT SHOULD OCCUR AT KSAW AS THICK FOG STARTS TO SLOWLY
MIX OUT. BY EVENING AS A COLD FRONT MOVES THROUGH...CONDITIONS WILL
IMPROVE TO MVFR AS CIGS RISE WITH DRIER AIR AND DOWNSLOPE WEST WINDS
OCCUR AT KSAW.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE ACROSS NORTHERN MINNESOTA WILL DRIFT OVER EASTERN UPPER
MICHIGAN BY LATE AFTERNOON...BEFORE EXITING TO THE NEW ENGLAND
STATES WEDNESDAY...WITH A FEW GUSTS NEARING 30KTS OVER EASTERN LAKE
SUPERIOR LATE TONIGHT INTO EARLY WEDNESDAY. OTHERWISE...WINDS SHOULD
REMAIN BELOW 30KTS THROUGH SUNDAY. A WEAK LOW WILL SLIDE ACROSS LAKE
SUPERIOR WEDNESDAY NIGHT INTO EARLY THURSDAY...FOLLOWED BY A RIDGE
THAT WILL SLOWLY BUILD OVER THE AREA THROUGH SATURDAY MORNING. LOW
PRESSURE WILL THEN NEAR LAKE SUPERIOR SATURDAY NIGHT INTO SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1137 AM CST TUE JAN 31 2012
.AVIATION...18Z TAFS
A COLD FRONT WILL PASS THROUGH FAR EASTERN MINNESOTA THIS
AFTERNOON...AND CONTINUE EAST THROUGH WISCONSIN. WINDS WILL REMAIN
OR SWITCH TO THE WEST/NORTHWEST AND IFR OR LOW MVFR CEILINGS WILL
CONTINUE TO SPREAD TO THE EAST WITH THE CAA. THERE MAY BE A BRIEF
PERIOD OF RAIN OR SNOW AS THE FRONT MOVES THROUGH. TONIGHT...LOW
MVFR OR IFR CEILINGS WILL CONTINUE ALONG WITH SOME FOG WITH VSBYS 3
TO 5SM. THE LOWER CEILINGS WILL GRADUALLY LIFT ON ACROSS THE
SOUTHERN HALF OF THE NORTHLAND WEDNESDAY AS WINDS BACK TO MORE
S/SW.
&&
.PREV DISCUSSION... /ISSUED 1032 AM CST TUE JAN 31 2012/
UPDATE...
THE MAIN AREA OF FREEZING RAIN AND/OR SLEET HAS MOVED OFF TO THE
EAST THIS MORNING...AND SKIES HAVE CLEARED OFF MORE THAN
ANTICIPATED OVER MUCH OF THE NORTHLAND. SO...DECIDED TO CANCEL THE
WINTER WEATHER ADVISORY. THERE IS A CHANCE OF SOME LIGHT SNOW
ACCUMULATION ACROSS THE NORTH...WITH A RAIN SNOW MIX POSSIBLE
AROUND THE TWIN PORTS AREA. ONLY A LIGHT SLUSHY MIX WILL BE
POSSIBLE. THE COLD FRONT WILL LIKELY SLIDE BY TO THE
NORTH...SPARING DULUTH OF ANY SIGNIFICANT PRECIP.
PREV DISCUSSION... /ISSUED 417 AM CST TUE JAN 31 2012/
SHORT TERM...
A LOW PRESSURE SYSTEM OVER NORTH CENTRAL MINNESOTA WILL MOVE EASTWARD
TODAY AND CONTINUE TO BRING FREEZING RAIN OVER THE IRON RANGE AND
ARROWHEAD THIS MORNING. CONTINUED THE WINTER WEATHER ADVISORY FOR
AREAS BASICALLY NORTH OF HIGHWAY 2 IN MINNESOTA THROUGH NOON. A
PUSH OF DRIER AIR TO THE SOUTHWEST OF THE LOW HAS PARTIALLY
CLEARED THE SKIES ACROSS WEST CENTRAL MINNESOTA. THE PATCHY
FREEZING RAIN SOUTH OF HIGHWAY 2 HAS MOVED EAST OF THE FORECAST
AREA AND DIMINISHED AND THEREFORE DROPPED THE WINTER WEATHER
ADVISORY FOR THOSE LOCATIONS. A COLD FRONTAL BOUNDARY DRAPED OVER
EXTREME NORTHWESTERN MINNESOTA AND EASTERN NORTH DAKOTA IS THE
FOCUS OF THE NEXT ROUND OF PRECIPITATION. PER SURFACE
OBSERVATIONS...MOST OF THE PRECIPITATION IS FALLING AS FREEZING
RAIN. 4 KM WRF AND HRRR HAVE THIS BAND OF PRECIPITATION
DISSIPATING AS IT MOVES EASTWARD. TEMPERATURES WILL BE WARM
ENOUGH BY 18Z THAT WILL BRING THE PRECIPITATION TO MAINLY A
LIQUID STATE IF IT HOLDS TOGETHER. AS THE FRONTAL BOUNDARY MOVES
INTO NORTHWESTERN WISCONSIN...SOME PATCHY FREEZING DRIZZLE IS
POSSIBLE ALONG THE SOUTH SHORE OF LAKE SUPERIOR...EAST OF
SUPERIOR...IN THE EARLY EVENING WITH THE LOSS OF DIURNAL WARMING.
THERE STILL WILL BE A CHANCE OF PRECIPITATION ON THE BACK SIDE OF
THE LOW EARLY TONIGHT IN THE FORM OF LIGHT SNOW ALONG THE
BORDERLAND. TEMPERATURES BEHIND THE FRONT WILL BE MODIFIED BY
PACIFIC AIR ALLOWING FOR THE 30S TO CONTINUE INTO WEDNESDAY. A
WEAK SHORTWAVE WILL MOVE OUT OF CANADA WEDNESDAY AFTERNOON THAT
WILL BRING A SLIGHT CHANCE OF LIGHT SNOW TO THE NORTHWESTERN PART
OF THE FORECAST AREA.
EXTENDED...WEDNESDAY NIGHT THROUGH TUESDAY.
A WAVY ZONAL FLOW KEEPS CLOUDS AND A FEW PERIODS OF SCHC POPS FOR
-SN IN THE FCST THROUGH THE REMAINDER OF THE WEEK. A LONG WAVE
TROUGH DEEPENS INTO A CLOSED LOW OVER THE SRN/CENTRAL PLAINS THROUGH THE
WEEKEND. LATEST GFS/ECM/GEM HAVE SIMILAR SOLUTIONS SUGGESTING THE
BUILDING RIDGE BEHIND THE LOW BECOMES PINCHED OFF OVER THE NRN
PLAINS/SRN CANADA DURING THIS TIME. THIS WOULD BRING QUITE WEATHER
AND ANOTHER STRETCH OF WELL ABOVE NORMAL TEMPS WITH DAYTIME HIGHS IN
THE 30S FOR THE DLH CWA. MODELS CONTINUE TO SHOW DIFFERENCES IN HOW
FAR NORTH THE CUT OFF LOW MIGRATES INTO THE BEGINNING OF NEXT WEEK
WITH THE GFS THE MOST PROGRESSIVE AND FURTHEST NORTH WITH THE LOW
LIFTING OVER THE SRN GREAT LAKES BY SUNDAY. ATTM...THE PRECIP
ASSOCIATED WITH THE SRN STREAM LOW LOOKS TO REMAIN SOUTH OF THE
FA.
&&
.POINT TEMPS/POPS...
DLH 35 20 34 22 / 20 10 10 10
INL 31 18 34 20 / 50 10 20 10
BRD 36 22 39 20 / 10 10 10 0
HYR 39 22 35 21 / 10 10 10 0
ASX 37 23 36 23 / 10 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....GRANING
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1032 AM CST TUE JAN 31 2012
.UPDATE...
THE MAIN AREA OF FREEZING RAIN AND/OR SLEET HAS MOVED OFF TO THE
EAST THIS MORNING...AND SKIES HAVE CLEARED OFF MORE THAN
ANTICIPATED OVER MUCH OF THE NORTHLAND. SO...DECIDED TO CANCEL THE
WINTER WEATHER ADVISORY. THERE IS A CHANCE OF SOME LIGHT SNOW
ACCUMULATION ACROSS THE NORTH...WITH A RAIN SNOW MIX POSSIBLE
AROUND THE TWIN PORTS AREA. ONLY A LIGHT SLUSHY MIX WILL BE
POSSIBLE. THE COLD FRONT WILL LIKELY SLIDE BY TO THE
NORTH...SPARING DULUTH OF ANY SIGNIFICANT PRECIP.
&&
.PREV DISCUSSION... /ISSUED 606 AM CST TUE JAN 31 2012/
AVIATION...
A LOW PRESSURE SYSTEM WILL TRACK EAST OVER THE REGION THROUGH THE
AFTERNOON. VFR CIGS THIS MORNING WILL LOWER TO MVFR WITH -DZ OR
-RASN WITH THE COLD FRONT/LOW PASSAGE. AS THE LOW DEPARTS TO OVER THE
GREAT LAKES OVERNIGHT...WRAP AROUND MOISTURE AND COOLER AIR WILL
BRING LOWERING CEILINGS AND A POSSIBILITY FOR REDUCED VSBYS AND
BR. THE DRIER AIR ALOFT MAY RESULT IN SOME FZDZ LATE TONIGHT.
HOWEVER...HAVE LEFT ANY MENTION OF FZDZ OUT OF TAFS AT THIS TIME
DUE TO UNCERTAINTIES THAT FAR OUT.
PREV DISCUSSION... /ISSUED 417 AM CST TUE JAN 31 2012/
SHORT TERM...
A LOW PRESSURE SYSTEM OVER NORTH CENTRAL MINNESOTA WILL MOVE EASTWARD
TODAY AND CONTINUE TO BRING FREEZING RAIN OVER THE IRON RANGE AND
ARROWHEAD THIS MORNING. CONTINUED THE WINTER WEATHER ADVISORY FOR
AREAS BASICALLY NORTH OF HIGHWAY 2 IN MINNESOTA THROUGH NOON. A
PUSH OF DRIER AIR TO THE SOUTHWEST OF THE LOW HAS PARTIALLY
CLEARED THE SKIES ACROSS WEST CENTRAL MINNESOTA. THE PATCHY
FREEZING RAIN SOUTH OF HIGHWAY 2 HAS MOVED EAST OF THE FORECAST
AREA AND DIMINISHED AND THEREFORE DROPPED THE WINTER WEATHER
ADVISORY FOR THOSE LOCATIONS. A COLD FRONTAL BOUNDARY DRAPED OVER
EXTREME NORTHWESTERN MINNESOTA AND EASTERN NORTH DAKOTA IS THE
FOCUS OF THE NEXT ROUND OF PRECIPITATION. PER SURFACE
OBSERVATIONS...MOST OF THE PRECIPITATION IS FALLING AS FREEZING
RAIN. 4 KM WRF AND HRRR HAVE THIS BAND OF PRECIPITATION
DISSIPATING AS IT MOVES EASTWARD. TEMPERATURES WILL BE WARM
ENOUGH BY 18Z THAT WILL BRING THE PRECIPITATION TO MAINLY A
LIQUID STATE IF IT HOLDS TOGETHER. AS THE FRONTAL BOUNDARY MOVES
INTO NORTHWESTERN WISCONSIN...SOME PATCHY FREEZING DRIZZLE IS
POSSIBLE ALONG THE SOUTH SHORE OF LAKE SUPERIOR...EAST OF
SUPERIOR...IN THE EARLY EVENING WITH THE LOSS OF DIURNAL WARMING.
THERE STILL WILL BE A CHANCE OF PRECIPITATION ON THE BACK SIDE OF
THE LOW EARLY TONIGHT IN THE FORM OF LIGHT SNOW ALONG THE
BORDERLAND. TEMPERATURES BEHIND THE FRONT WILL BE MODIFIED BY
PACIFIC AIR ALLOWING FOR THE 30S TO CONTINUE INTO WEDNESDAY. A
WEAK SHORTWAVE WILL MOVE OUT OF CANADA WEDNESDAY AFTERNOON THAT
WILL BRING A SLIGHT CHANCE OF LIGHT SNOW TO THE NORTHWESTERN PART
OF THE FORECAST AREA.
EXTENDED...WEDNESDAY NIGHT THROUGH TUESDAY.
A WAVY ZONAL FLOW KEEPS CLOUDS AND A FEW PERIODS OF SCHC POPS FOR
-SN IN THE FCST THROUGH THE REMAINDER OF THE WEEK. A LONG WAVE
TROUGH DEEPENS INTO A CLOSED LOW OVER THE SRN/CENTRAL PLAINS THROUGH THE
WEEKEND. LATEST GFS/ECM/GEM HAVE SIMILAR SOLUTIONS SUGGESTING THE
BUILDING RIDGE BEHIND THE LOW BECOMES PINCHED OFF OVER THE NRN
PLAINS/SRN CANADA DURING THIS TIME. THIS WOULD BRING QUITE WEATHER
AND ANOTHER STRETCH OF WELL ABOVE NORMAL TEMPS WITH DAYTIME HIGHS IN
THE 30S FOR THE DLH CWA. MODELS CONTINUE TO SHOW DIFFERENCES IN HOW
FAR NORTH THE CUT OFF LOW MIGRATES INTO THE BEGINNING OF NEXT WEEK
WITH THE GFS THE MOST PROGRESSIVE AND FURTHEST NORTH WITH THE LOW
LIFTING OVER THE SRN GREAT LAKES BY SUNDAY. ATTM...THE PRECIP
ASSOCIATED WITH THE SRN STREAM LOW LOOKS TO REMAIN SOUTH OF THE
FA.
AVIATION...01/31/06Z ISSUANCE...
VFR WITH AREAS OF HIGH-END MVFR IN CLOUDS AND FREEZING DRIZZLE OR
FREEZING RAIN. FREEZING RAIN MAY MIX WITH LIGHT SNOW FROM
LONG VILLE-DULUTH ON NORTH TUESDAY MORNING. LOW-END VFR WITH A
LITTLE HIGH-END MVFR IN CLOUDS WILL PERSIST TUESDAY AFTERNOON AND
EVENING.
&&
.POINT TEMPS/POPS...
DLH 35 20 34 22 / 20 10 10 10
INL 31 18 34 20 / 50 10 20 10
BRD 36 22 39 20 / 10 10 10 0
HYR 39 22 35 21 / 10 10 10 0
ASX 37 23 36 23 / 10 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TENTINGER
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
237 PM CST TUE JAN 31 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A MOISTURE
STARVED LOW PRESSURE SYSTEM MOVING OVER THE CENTRAL UPPER PENINSULA
EARLY THIS AFTERNOON...AND ITS ASSOCIATED COOL FRONT PUSHING ACROSS
CENTRAL WISCONSIN. THE COLDER AIR IS LAGGING BEHIND THE FRONT AND
CAN BE MARKED BY THE LEADING EDGE OF A LOW STRATUS DECK THAT IS
SHIFTING SE OVER MINNESOTA AND ALMOST TO THE WI BORDER. DESPITE THE
SHALLOW NATURE OF THE LOW MOISTURE ON 12Z RAOBS...MIXING HAS NOT
DETERRED ITS PROGRESS SO FAR TODAY. WILL MAKE SOME LAST MINUTE
ADJUSTMENTS TO SPEED UP ITS FORWARD MOTION IF THIS CONTINUES TO BE
THE CASE. AS THESE CLOUDS ADVANCE TOWARDS NORTHERN
WISCONSIN...CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...LOW PRESSURE WILL CONTINUE TO TRACK TO THE EAST OVER THE
EASTERN UPPER PENINSULA INTO SOUTHEAST ONTARIO. MID AND HIGH CLOUDS
WILL DEPART THIS EVENING WITH THE ELONGATED SHORTWAVE TROUGH...BUT
PLENTY OF LOW CLOUDS UPSTREAM WILL SHIFT SE WITHIN A COOLER AIRMASS
WRAPPING AROUND THE LOW AND INTO THE NORTHERN HALF OF THE STATE.
ALTHOUGH THE MOISTURE IS SHALLOW AND SOME EROSION IS EXPECTED...THE
COOLER AIRMASS WILL PROMOTE ITS ADVANCEMENT ACROSS NORTH-CENTRAL AND
CENTRAL WISCONSIN TONIGHT. THINK DOWNSLOPING SHOULD PREVENT THE
STRATUS FROM MAKING IT INTO THE FOX VALLEY AND NORTHEAST
WISCONSIN...SO HAVE KEPT PARTLY CLOUDY WORDING THERE. NO REAL
CHANCE OF DECOUPLING TONIGHT...SO LOWS WILL BE MILD AND RANGE FROM
THE LOWER 20S NORTH TO AROUND 30 SOUTHEAST.
WEDNESDAY...STRATUS WILL LIKELY HANG AROUND FOR MUCH OF THE MORNING
OVER NORTHERN WISCONSIN THOUGH SOME EROSION IS LIKELY OVER CENTRAL
WISCONSIN WITH DAYTIME HEATING. THE COOLER AIRMASS WILL CONTINUE TO
MODERATE THROUGH THE AFTERNOON SO EXPECTING CLOUDS TO RETREAT TO THE
NORTH OR NORTHEAST THROUGH THE DAY. ALSO IN THE AFTERNOON...THE
NEXT SHORTWAVE TROUGH WILL MOVE INTO WESTERN WISCONSIN. MID-LEVELS
HAVE A DRY WEDGE SO NO REAL THREAT OF PRECIP. HIGHS WILL BE COOLER
THAN TODAY...AND WILL GO WITH MID TO UPPER 30S.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. SOUNDS LIKE A
BROKEN RECORD...BUT MORE MILD AND DRY WEATHER EXPECTED FOR THE
NEXT WEEK OR SO. THE SPLIT FLOW PATTER WILL CONTINUE WITH WEAK
SHORTWAVE TROUGHS MOVING BY TO THE NORTH THROUGH WITH LITTLE
MOISTURE WHILE MORE SIGNIFICANT SYSTEMS IN THE SOUTHERN STREAM STAY
TO OUR SOUTH. ANY PHASING THAT TAKES PLACE IS WELL TO OUR EAST.
THE BEST CHANCE OF ANY PRECIPITATION LOOKS TO BE SUNDAY OR SUNDAY
NIGHT AS SYSTEM IN THE SOUTHERN STREAM PASSES BY TO THE SOUTH. IT
MAY CLIP CENTRAL AND NORTHERN WISCONSIN WITH SOME LIGHT SNOW OR
RAIN BUT THAT/S ABOUT IT.
&&
.AVIATION...
LOW PRESSURE WILL BE PASSING OVER THE U.P. THIS AFTERNOON WITH ONLY
WIDESPREAD MID AND HIGH CLOUDS THAT WILL DEPART LATE THIS AFTERNOON
INTO THIS EVENING. BIGGER CONCERN FOR THE TAF DEPARTMENT IS THE
LARGE AREA OF IFR CIGS BEHIND THE LOW OVER THE DAKOTAS AND
MINNESOTA. COOLER AIR BEHIND THE LOW WILL FILTER ACROSS NORTHERN
WISCONSIN TONIGHT WHICH WILL PROMOTE THE ADVANCEMENT OF THIS IFR
STRATUS DECK. SOME MIXING WILL LIKELY CAUSE THE STRATUS TO BREAK UP
THIS AFTERNOON...WHICH WILL ONLY SERVE TO DELAY ITS ARRIVAL. DO NOT
SEE MUCH TO STOP IT GETTING INTO RHI THIS EVENING. CENTRAL
WISCONSIN IS ON THE EDGE OF THIS COOLER AIRMASS SO BELIEVE THE
STRATUS WILL MAKE A RUN AT AUW/CWA. THREW A TEMPO IN THE TAFS FOR
TONIGHT TO ACCOUNT FOR THIS. AM COUNTING ON DOWNSLOPING TO KEEP THE
STRATUS OUT OF THE FOX VALLEY AND NE WISCONSIN. STRATUS SHOULD
RETREAT TOMORROW MORNING WITH DAYTIME HEATING BUT SHOULD HANG AROUND
NORTHERN WISCONSIN THROUGH THE REST OF THE TAF PERIOD.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/RDM