Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/27/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
746 PM MST TUE FEB 26 2013
.UPDATE...
ISSUED AT 740 PM MST TUE FEB 26 2013
ISSUED A SHORT FUSED WINTER WEATHER ADVISORY FOR NORTHERN EL PASO
COUNTY...AS WINDS HAVE INCREASED AND BANDS OF MODERATE TO HEAVY
SNOW CONTINUE TO ROTATE SOUTH. LATEST HRRR KEEPS PRECIP GOING UNTIL
08Z...AND SHOWS WIND GUSTS OVER 30 KTS NEAR THE PALMER DIVIDE
UNTIL AT LEAST 10Z. HAVE HAD NUMEROUS REPORTS OF ROAD
CLOSURES/DIFFICULT TRAVEL DUE TO WIDESPREAD BLOWING/DRIFTING SNOW
NORTH AND EAST OF COS. FORECASTS FOR THE REMAINDER OF THE AREA
WERE REFRESHED TO ACCOUNT FOR ONGOING PRECIP.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 325 PM MST TUE FEB 26 2013
SHORT TERM METEOROLOGICAL ISSUES INCLUDE BUT ARE NOT LIMITED TO
POPS/SNOW AMOUNTS...WINDS AND TEMPERATURES. FORECAST DISTRICT
CURRENTLY NOTING SNOW ACTIVITY...ESPECIALLY OVER THE MOUNTAINS AND
HIGHER TERRAIN AREAS AS WELL AS OVER MANY PORTIONS OF THE I-25
CORRIDOR AS WELL AS AREAS OF GUSTY NORTH WINDS.
AS OF 3 PM MST...REPORTED SNOW AMOUNTS HAVE GENERALLY BEEN
UNDER 4 INCHES...I.E RECENTLY RECEIVED A SPOTTER SNOW REPORT OF
3.5 INCHES OF SNOW 11 MILES TO THE NORTH-NORTHEAST OF CRESTONE IN
CUSTER COUNTY(PUBLIC ZONE 72) WITH LIGHT SNOW CONTINUING.
LATEST SHORT/NEAR-TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS AND REAL-TIME DATA INDICATE THAT THE UPPER DISTURBANCE
WILL CONTINUE TO IMPACT MANY SECTIONS OF THE CWFA INTO TONIGHT
BEFORE SHIFTING EAST OF THE FORECAST DISTRICT BY WEDNESDAY MORNING.
STILL EXPECT THAT 4 TO 8 INCH SNOW TOTALS(INCLUDING SNOW THAT HAS
ALREADY FALLEN EARLIER TODAY...I.E. 12 TO 18 HOUR TIME-RANGE) WILL
BE POSSIBLE OVER MANY MOUNTAIN AND HIGHER FOOTHILL LOCATIONS WITH
2 TO 5 INCHES OF SNOW OVER NORTHERN EL PASO COUNTY AND 2 INCHES OR
LESS OF SNOW ELSEWHERE WILL BE NOTED BEFORE THIS EVENT ENDS LATER
TONIGHT. IN ADDITION...A FEW LOCALLY HIGHER SNOW AMOUNTS WILL ALSO
BE POSSIBLE BY SUNRISE WEDNESDAY.
IN ADDITION TO THE SNOW FROM THIS AFTERNOON INTO TONIGHT...GUSTY
NORTH WINDS AT TIMES ARE ALSO EXPECTED IN COMBINATION WITH CONTINUED
BELOW SEASONAL LATE FEBRUARY TEMPERATURES.
FOR WEDNESDAY...AS UPPER SYSTEM DEPARTS SOUTHERN
COLORADO...ANTICIPATE THAT GENERALLY DRY CONDITIONS IN COMBINATION
WITH CLEARING SKIES...DECREASING WINDS(EXCEPT FOR POSSIBLY FAR
EASTERN SECTIONS) AND WARMER TEMPERATURES(ALTHOUGH STILL BELOW LATE
FEBRUARY CLIMATOLOGICAL AVERAGES) WILL BE NOTED ACROSS THE FORECAST
DISTRICT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM MST TUE FEB 26 2013
WED NIGHT...GENERALLY DRY NW FLOW ALOFT WL BE OVR THE AREA...BUT
THERE COULD BE A FEW SHOWERS OVR THE CONTDVD MAINLY IN THE EVENING
HOURS. FORECAST MODELS DO NOT AGREE ON THE WEATHER FOR LATE THU AND
THU NIGHT. THE GFS HAS THE AREA MOSTLY DRY INTO THE EARLY
AFTERNOON...BUT LATE IN THE AFTERNOON A SHORTWAVE TROF DROPS INTO
SWRN WY AND AHEAD OF THIS SYSTEM...WITH MOISTURE INCREASING AND THE
GFS BRINGS CHANCES FOR SNOW TO THE CENTRAL MTS AND TO THE PIKES PEAK
TELLER COUNTY REGION. THEN THU NIGHT THAT SYSTEM DROP SOUTH THU
CO...SPREADING PCPN CHANCES SOUTHWARD AS WELL. THE NAM AND THE ECMWF
DO NOT HAVE THIS SHORTWAVE TROF AND IS KEEPING THE WEATHER DRY. WL
STICK WITH SOME PCPN IN THE CENTRAL MTS...WITH MAYBE JUST A FEW
SHOWERS OVR THE OTHER MTN PEAKS AND SEE WHAT FUTURE MODEL RUNS BRING.
FRI...AS AN UPR LOW DROPS INTO WRN MO AND ERN KS A FRONT BRING
SOME BREEZY NORTHERLY WINDS TO MUCH OF THE EASTERN CO PLAINS. THE
NAM IS MOSTLY DRY OVR THE AREA FOR FRI...WHILE THE GFS AND ECMWF
BOTH SHOW SOME POTENTIAL FOR PCPN OVR THE MTS AND ERN PLAINS. AN
UPR RIDGE THEN BUILD OVR THE AREA FOR THE WEEKEND...RESULTING IN
DRY WEATHER AND WARMER TEMPS. LATE SUN THE UPR RIDGE GETS
FLATTENED OVR THE AREA AS A NEW UPR LOW MOVES INTO WRN MT. THE
TRACK OF THAT UPR LOW IS THEN QUITE UNCERTAIN AS THE GFS BRINGS IT
SOUTHEASTWARD AND ACRS NORTHEAST CO BY MIDDAY MON WHILE THE ECMWF
STILL HAS IT OVR MT. BY 06Z TUE THE GFS MOVES THE LOW INTO NRN
MO...WHILE THE ECMWF HAS IT OVR SRN MT AND NRN WY. THUS ITS HARD
TO SAY EXACTLY WHAT IS IN STORE FOR THE FORECAST AREA SUN NIGHT
AND MON BUT FOR NOW BOTH MODELS AT LEAST HAVE SOME PCPN OVR THE
CENTRAL MTS. WL PROBABLY SEE A SHORTWAVE RIDGE AND MAINLY DRY
WEATHER OVR THE AREA ON TUE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 325 PM MST TUE FEB 26 2013
A WEATHER DISTURBANCE WILL CONTINUE TO PUSH ACROSS THE AVIATION
DISTRICT THROUGH TONIGHT...ALLOWING AREAS OF SNOW AND LOWER
CIGS...CAPABLE OF PRODUCING MVFR TO LIFR CONDITIONS AT TIMES...ESPECIALLY
AT KCOS AND KPUB. VFR CONDITIONS SHOULD THEN RETURN TO THE
KALS...KCOS AND KPUB TAF SITES BY WEDNESDAY MORNING AND CONTINUE
INTO WEDNESDAY AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM MST WEDNESDAY FOR COZ084.
&&
$$
UPDATE...PETERSEN
SHORT TERM...77
LONG TERM...28
AVIATION...77
AREA FORECAST DISCUSSION
NWS DES MOINES IA
543 PM CST TUE FEB 26 2013
...UPDATED FOR THE 00Z AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
WINTER STORM WILL PERSIST THROUGH WEDNESDAY MORNING AS LIGHT TO
MODERATE SNOW BANDING CONTINUES ON THE BACKSIDE OF THE SURFACE LOW
LOCATED IN SOUTHEAST MISSOURI. SURFACE LOW LOOKS TO SLOWLY MIGRATE
NORTHEAST FROM SOUTHEAST MISSOURI INTO CENTRAL ILLINOIS THIS EVENING
INTO TOMORROW MORNING. LEANED TOWARD A SREF/GFS/NAM12 BLEND FOR
TRENDS TONIGHT.
WEAK LIFT WITHIN THE DENDRITIC GROWTH ZONE CONTINUES THIS AFTERNOON
AND TONIGHT...AND EVEN PERSISTS INTO WEDNESDAY MORNING. HIGHER
CONFIDENCE WITH THE ADDITIONAL LIGHT SNOW AMOUNTS THROUGH WEDNESDAY
MORNING RESULTING IN ROUGHLY 1 TO 4 INCHES OF ADDITIONAL SNOW
THROUGH 12Z ACROSS THE WARNING AREA. THE SNOW BAND AXIS LOOKS TO
CONTINUE TO SLOWLY PIVOT COUNTERCLOCKWISE AROUND THE CENTRAL PORTION
OF THE FORECAST RESULTING IN SOME AREAS RECEIVING AN ELONGATED
PERIOD OF MODERATE TO BRIEF HEAVY SNOW THIS EVENING. WITH THE
CURRENT TRACK OF THE SURFACE LOW...NOT EXPECTING THIS BAND TO DRIFT
SOUTHEAST ALL THAT MUCH UNTIL EARLY WEDNESDAY MORNING.
GENERALLY EXPECTING A HALF TO POSSIBLY ONE INCH PER HOUR SNOWFALL
RATES THIS EVENING WITH THE WEAK LIFT IN THE DENDRITIC LAYER. SREF
100MB/50MB DENDRITE GROWTH ZONE PARAMETER DEPICTING 80-90 PERCENT
PROBABILITY OF DENDRITIC SNOW THROUGH TOMORROW AND MATCHES UP WELL
WITH PREVIOUSLY MENTION BAND PIVOTING ACROSS CENTRAL IOWA. BUFR
SOUNDINGS REMAIN DEEPLY SATURATED THROUGH WEDNESDAY MORNING...WITH
THE RAP SHOWING A MID LEVEL DRY LAYER ADVECTING INTO DSM TO ALO AND
MAY SEE A BRIEF BREAK IN THE SNOW MID TO LATE EVENING.
WINDS ATOP THE MIXED LAYER RANGE FROM 25 TO 30KTS THIS AFTERNOON AND
TONIGHT AND EXPECTING BLOWING SNOW IMPACTS TO CONTINUE AS WELL.
LEANED TOWARDS THE GFS/SREF QPF AMOUNTS TONIGHT AS NAM SEEMS TO HIGH
ACROSS THE EAST...ESPECIALLY WITH THE WEAKER FORCING.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
WEAKER LIFT WILL PERSIST INTO WEDNESDAY WITH THE SPC SREF INDICATING
DEEP DENDRITIC GROWTH LAYER CONTINUING THROUGH CENTRAL IOWA. ALL
SOUNDINGS CONTINUE TO ALSO SHOW DEEP SATURATION THROUGH AT LEAST
MIDDAY TOMORROW AND ANTICIPATE THE LIGHT SNOW TO CONTINUE. HAVE
GONE WITH LIKELY TO CATEGORICAL POPS FOR MUCH OF THE AREA UNDER THE
CURRENT HEADLINE WITH THE SHARP CUTOFF ON THE NORTHERN SIDE OF THE
PCPN AREA PERSISTING. WINDS WILL REMAIN RATHER STRONG THROUGH THE
DAY WITH BRISK NORTHWEST FLOW PERSISTING WITH DECENT PRESSURE
GRADIENT. EVENTUALLY...THE FORCING WILL BE DIMINISHING WITH THE
SNOW TAPERING TO FLURRIES BY LATER IN THE DAY. CLOUDINESS IS
EXPECTED TO PERSIST AS WELL IN CYCLONIC FLOW ON BACKSIDE INTO
WEDNESDAY NIGHT WITH AN APPROACHING SHORTWAVE ON THURSDAY AND
THURSDAY NIGHT HELPING THE CLOUDINESS TO MAINTAIN. IN FACT...SOME
WEAK LIFT WITH THIS PASSING WAVE ON FRIDAY MAY HELP TO PRODUCE SOME
FLURRIES IN SOUTHERN IOWA DURING THE DAY.
UPPER RIDGING WILL SLIDE THROUGH THE REGION INTO THE WEEKEND WITH
QUIET WEATHER DURING THIS TIME. TEMPERATURES WILL REMAIN BELOW
NORMAL WITH WIDESPREAD SNOW PACK AND ONLY WEAK ADVECTION UNTIL
SUNDAY NIGHT. THIS WARM ADVECTION IS IN ADVANCE OF THE NEXT SYSTEM
WHICH WILL PASS THROUGH THE REGION ON MONDAY INTO TUESDAY IN BROAD
NORTHWEST FLOW. BOTH GFS AND EURO HAVE INDICATED SOME DECENT
FORCING AND ANTICIPATE PCPN DEVELOPING AND SLIDING ACROSS THE STATE
ON MONDAY INTO EARLY TUESDAY. SOUNDINGS WOULD INDICATE GENERALLY
SNOW DURING THIS TIME ACROSS THE STATE WITH LIGHT TO MODERATE
ACCUMULATIONS EXPECTED.
&&
.AVIATION...26/18Z
AREAS OF LIGHT TO MODERATE SNOW WILL CONTINUE TO IMPACT THE
KDSM/KOTM/KALO AREAS THROUGH TONIGHT. A MIX OF MVFR TO IFR STRATUS
WILL ACCOMPANY THE SNOW. KFOD AND KMCW WILL HAVE LESS SNOW THOUGH
PERIODS OF MVFR STRATUS OR LOWER ARE POSSIBLE AT TIMES. GUSTY
NORTHERLY WINDS WILL PREVAIL THROUGH WEDNESDAY
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST WEDNESDAY FOR ADAIR-ADAMS-
APPANOOSE-BLACK HAWK-BOONE-CLARKE-DALLAS-DAVIS-DECATUR-GRUNDY-
HARDIN-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-
POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR AUDUBON-
BREMER-BUTLER-CASS-FRANKLIN-GREENE-GUTHRIE-HAMILTON.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS TOPEKA KS
509 AM CST MON FEB 25 2013
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
THE 09Z RAP AND 06Z NAM HAVE BEEN SHOWING DRY LOW LEVEL AIR
ENTRAINING FROM THE NORTHEAST THROUGH MUCH OF THE DAY TODAY.
ADDITIONALLY THE GFS AND NAM DO NOT BRING THE TROWAL WITH THE
HEAVIEST SNOWFALL INTO THE TERMINALS UNTIL AFTER 00Z. THEREFORE
EXPECT VFR CONDITIONS TO PREVAIL TODAY AND HAVE PUSHED BACK THE IFR
CIGS AND VSBY WITH -SN UNTIL THIS EVENING.
WOLTERS
&&
.PREV DISCUSSION... /402 AM CST MON FEB 25 2013/
FORECAST IS STILL ON TRACK FOR A POTENT WINTER SYSTEM...EXPECTED TO
AFFECT THE AREA WITH MODERATE TO HEAVY SNOW AND STRONG WINDS MONDAY
THROUGH INTO TUESDAY.
A VERY VIGOROUS MID LEVEL TROUGH IS CURRENTLY EVIDENT ON WATER VAPOR
IMAGERY AS IT SPINS ACROSS EASTERN NEW MEXICO INTO FAR WESTERN
TEXAS. THE TRACK OF THIS WAVE WILL LIKELY RUN ALONG THE RED RIVER TO
NEAR DFW BEFORE NEGATIVELY TILTING AND EJECTING NORTHEASTWARD
THROUGH OKLAHOMA INTO NW ARKANSAS. RADAR TRENDS SHOW INCREASING
REFLECTIVITY RETURNS FROM ACROSS WESTERN OKLAHOMA AND
TEXAS...INDICATING MORE INTENSE PRECIP WITH ACCOMPANYING THUNDER.
ALSO EVIDENT ON RADAR IS A DEFORMATION BAND TAKING SHAPE ACROSS
SOUTH CENTRAL KANSAS...EXTENDING NORTHEASTWARD INTO NORTH CENTRAL
AND NORTHEAST KANSAS. THIS DEFORMATION BAND WILL KICK OFF THE
PRECIPITATION EXPECTED FROM THIS WINTER STORM ACROSS THE REGION.
SURFACE OBSERVATIONS INDICATE ABOVE FREEZING TEMPS IN NORTHEAST AND
EAST CENTRAL KANSAS...AND AT OR BELOW FREEZING IN CENTRAL AND NORTH
CENTRAL KANSAS. EXPECT THE LIGHT PRECIP TO FALL AS LIGHT SNOW...OR
PERHAPS SOME LIGHT FREEZING RAIN...WITH MINOR TO NO ICE
ACCUMULATION.
THE AFOREMENTIONED MID LEVEL WAVE IS EXPECTED TO EJECT
NORTH/NORTHEAST INTO NORTHWEST ARKANSAS LATER TONIGHT TAKING WITH IT
A STRONG PV ANOMALY. THE PV ANOMALY WILL LIKELY TRAVERSE JUST SOUTH
OF THE FORECAST AREA. WITH THE LOW AND MID LEVEL TROUGHS EXPECTED TO
PASS THROUGH JUST SOUTH OF THE FORECAST AREA COLDER AIR WILL BE
ALLOWED TO FILTER IN...ALLOWING FOR A QUICKER COOLING OF THE THERMAL
PROFILE THROUGHOUT THE DAY. AREAS ALONG AND NORTH/NORTHWEST OF THE
KANSAS TURNPIKE WILL LIKELY GO STRAIGHT TO SNOW AS THE COLUMN
SATURATES...WITH AREAS SOUTH/SOUTHEAST OF THE TURNPIKE LIKELY
HOLDING ONTO A PERIOD OF LIGHT RAIN/FREEZING RAIN THROUGH THE
DAYTIME HOURS ON MONDAY. WITH SURFACE TEMPS HAVING A TOUGH TIME
GETTING BELOW FREEZING WHERE LIGHT RAIN IS EXPECTED ITS UNLIKELY AT
THIS TIME FOR FREEZING RAIN TO PRODUCE ANY KIND OF ACCUMULATION. BY
MID DAY FORECAST SOUNDINGS VIRTUALLY ACROSS THE ENTIRE AREA INDICATE
A GRADUAL MOISTENING OF THE THERMAL COLUMN AS IT COOLS. ISENTROPIC
SURFACES ALONG THE 290 TO 305 K SURFACES INDICATE THAT THE EASTERN
HALF OF THE CWA...TOWARD TOP/LWC/MCI WILL TAKE A WHILE TO OVERCOME
THE DRY AIR...AS CONDENSATION PRESSURE DEFICITS REMAIN AROUND 50 TO
100 MB UNTIL ABOUT 21Z. RIGHT NOW PEGGING BETWEEN 21Z AND 00Z AS
A LIKELY START TIME FOR LIGHT SNOW TO COMMENCE ALONG AND SOUTH OF
INTERSTATE 70. BY 00Z GFS/NAM INDICATE A VERY IMPRESSIVE TROWAL
SIGNATURE WITH CONDENSATION PRESSURE DEFICITS NEAR 0 ALONG THE
PREVIOUSLY MENTIONED ISENTROPIC SURFACES INDICATING STRONG
ISENTROPIC ASCENT AND SATURATION. AROUND 00Z NAM/GFS ALSO SHOW OFF
A VERY IMPRESSIVE AND PRONOUNCED PERIOD OF LOW AND MID LEVEL
FRONTOGENESIS...MAINLY SOUTHEAST OF A LINE BETWEEN HIAWATHA AND
COUNCIL GROVE. DURING THIS TIME OF ENHANCED LOW/MID LEVEL
FRONTOGENESIS THE COLUMN BECOMES SATURATED THROUGH THE DENDRITIC
GROWTH ZONE...INDICATING EFFICIENT SNOWFALL IN FAR NE AND EC
KANSAS. CONCURRENT WITH THE STRONG FRONTOGENESIS IS AN AREA OF
WEAKENED STABILITY...INDICATED BY A RIBBON OF EPV AROUND -.5 TO
-1.0 PVU...JUST ABOVE THE MAIN FRONTOGENESIS BULLS EYE. GIVEN THIS
PERIOD OF POTENTIAL CONVECTIVE DEVELOPMENT (00Z TO 09Z TUESDAY)
THE POTENTIAL EXISTS FOR HEAVY SNOWFALL IN EAST CENTRAL KANSAS
WITH 1 TO POTENTIALLY 3 INCH PER HOUR RATES. BY 12Z TUESDAY THE
FRONTOGENESIS AND EPV INFLUENCES MOVE OFF TO THE EAST...AND LIGHT
SNOW MAY PERSIST WITHIN THE DEPARTING TROWAL THROUGH 12Z-18Z
TUESDAY.
REGARDING SNOW AMOUNTS...THE FORECAST REMAINS VERY TRICKY AS THERE
WILL LIKELY BE A PRETTY TIGHT GRADIENT BETWEEN THE HIGHEST AMOUNTS
IN EC KANSAS AND THE NORTHERN/WESTERN PERIPHERY OF THE SNOW
ACCUMULATIONS. ALTHOUGH MODEL CONSENSUS ON GENERAL TRACK OF THE
SYSTEM REMAINS PRETTY DECENT THE SLIGHTEST SHIFT IN ANY DIRECTION
WOULD BRING UNEXPECTED TOTALS TO AREAS ALONG THE PERIPHERY OF THE
SNOW SWATH. OBTAINED SNOW AMOUNTS FOR THIS FORECAST BY TAKING A
GENERAL CONSENSUS OF MODEL QPF AND TONING IT BACK TO ABOUT 75
PERCENT OF ITS OUTPUT. WHEN MULTIPLIED BY SNOW RATIOS RANGING FROM
12-15:1 THROUGHOUT THE EVENT THE FINAL SNOW FALL FORECAST FOR THIS
EVENT MATERIALIZED. GENERALLY EXPECT A 10-13 INCH SWATH TO FORM
ACROSS EAST CENTRAL KANSAS...DECREASING RATHER RAPIDLY TO THE NORTH
AND WEST...TO AROUND 10 INCHES IN TOP/LWC...AND 7-9 INCHES IN
MHK...ABILENE...AND HIAWATHA...AND 3-5 INCHES ACROSS NORTH CENTRAL
KANSAS. WAS TEMPTED TO LOWER AMOUNTS EVEN MORE IN THE EASTERN
ZONES...CONSIDERING THE POSSIBILITY OF THE SYSTEM CREEPING EVEN
FURTHER SOUTH/EAST...BUT 00Z 4KM WRF INDICATED THAT THE TROWAL
PORTION OF THE SYSTEM MAY RESIDE OVER THE AREA...PRODUCING LIGHT TO
MODERATE SNOW THROUGH POTENTIALLY TUESDAY NIGHT...BRINGING EVEN MORE
ACCUMULATION.
A TIGHTENING SURFACE LOW PRESSURE GRADIENT WILL CAUSE WINDS OUT OF
THE NORTH/NORTHEAST TO INCREASE THROUGHOUT THE DAY...AND INTO
TONIGHT...PRODUCING STRONG WINDS APPROACHING 20 TO 25 MPH WITH GUSTS
NEARING 35 MPH. MODEL SOUNDINGS INDICATE STRONG LOW LEVEL WINDS
APPROACHING 50 KTS...BUT WITH LOW LEVEL LAPSE RATES NOT BEING
EXTREMELY STEEP DO NOT EXPECT ENOUGH MIXING TO ALLOW THOSE WINDS TO
REACH THE SURFACE...THEREFORE TRUE BLIZZARD CONDITIONS ARE NOT
EXPECTED...HOWEVER THE STRONG WINDS CONCURRENT WITH THE HEAVIEST
SNOW WILL LIKELY BRING A PERIOD OF NEAR WHITE OUT CONDITIONS BETWEEN
00Z AND 012Z TUESDAY MORNING.
AS A RESULT OF THIS FORECAST...WILL LEAVE THE
HEADLINES ALONE AND LET THE UPCOMING DAY SHIFT ASSESS THE SYSTEM AND
MAKE THE DECISION TO TWEAK THE WARNING/ADVISORY AREA.
MID RANGE TO EXTENDED FORECAST (WEDNESDAY THROUGH SUNDAY)...
COLD AIR WILL LIKELY STAY IN PLACE THROUGH THE REST OF THE FORECAST
PERIOD...AS A BROAD SURFACE HIGH SLIDES INTO PLACE. ANOTHER WEAK
TROUGH WILL COME THROUGH THE AREA ON WEDNESDAY AND MAY SQUEEZE OUT A
LITTLE BIT OF MOISTURE TO PRODUCE SOME VERY LIGHT SNOW FALL WITH
PERHAPS ANOTHER FEW TENTHS OF AN INCH OF ACCUMULATION. AFTER
WEDNESDAY THE FORECAST LOOKS DRY WITH COOL TEMPERATURES IN THE MID
30S TO LOWER 40S REMAIN THROUGH THE WEEK/WEEKEND.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 6 AM MONDAY TO NOON CST TUESDAY FOR
KSZ012-023-024-026-038>040-054>056-058-059.
WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR KSZ008-009-
020.
WINTER STORM WARNING UNTIL NOON CST TUESDAY FOR KSZ021-022-
034>037.
WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO NOON CST TUESDAY FOR
KSZ010-011.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1036 PM EST TUE FEB 26 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL PUSH INTO THE AREA OVERNIGHT...BRINGING A
WINTRY MIX OF PRECIPITATION TO THE AREA. COLDER AIR ALOFT WILL
THEN BRING A MIX OF RAIN AND SNOW SHOWERS TO THE AREA FOR THE
REMAINDER OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST RADAR AND SATELLITE TRENDS AS A DRY SLOT WORKS INTO
THE RIDGES OF WV/MD/PA.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED LOW CENTERED
ACROSS SOUTHERN ILLINOIS. 500MB VORT ENERGY IS SLIDING AROUND THE
LOW AND INTO THE UPPER OHIO VALLEY WHILE DRIER AIR ALOFT BEGINS TO
ADVECT FROM THE SOUTH INTO THE WV APPALACHIANS. 850MB ANALYSIS
INDICATES A WARM WEDGE OF 3-4C EXTENDING FROM NORTHERN WV INTO
SOUTHERN INDIANA COUNTY PENNSYLVANIA WITH A LOCALIZED AREA WITH
TEMPS 0-1C NORTHWEST OF PITTSBURGH. AT THE SURFACE...A 998MB LOW
IS CENTERED ACROSS THE OH/IN BORDER WITH AN OCCLUDED FRONT
EXTENDING FROM THIS FEATURE EASTWARD TO THE MASON-DIXON LINE.
00Z KPIT SOUNDING INDICATED A FREEZING 900-750MB LAYER WITH TEMPS
DROPPING TO -2C IN THE LAYER. ABOVE 750MB...THE MELTING LAYER HAS
WEAKENED...ONLY AROUND 1C. THIS SOUNDING WAS CONFIRMED EARLIER
FROM DUAL POLARIZATION RADAR REFLECTIVITY...CORRELATION
COEFFICIENT...AND DIFFERENTIAL REFLECTIVITY WHICH INDICATED AREAS
OF PREDOMINATELY SLEET WITH SNOW MIXING IN FOR THE PITTSBURGH
METRO AND AREAS NORTHWARD THIS EVENING. ALONG THE I-80
CORRIDOR...WET BULBING BROUGHT TEMPS DOWN TO NEAR FREEZING AND
THEY REMAIN STEADY THERE WITH AN EASTERLY LOW-LEVEL FLOW.
THUS...POCKETS OF FREEZING RAIN HAVE BEEN REPORTED THERE.
PRECIPITATION HAS MOSTLY COME TO AN END FOR THE LAUREL HIGHLANDS
AND ALLEGHENY FRONT AS THE DRY SLOT FINALLY WORKS INTO THE AREA.
OVERNIGHT...THE RAP/WRF-NMM INDICATE THE CLOSED LOW WILL SLIDE
NORTHEASTWARD ALONG THE OHIO RIVER...BECOMING CENTERED OVER THE
NORTHERN PANHANDLE OF WV BY 12Z WEDNESDAY. MEANWHILE...THE SURFACE
LOW WILL PUSH NORTHWARD INTO SOUTHERN MICHIGAN WITH THE OCCLUDED
FRONT EDGING SLOWLY NORTHEASTWARD INTO THE AREA. PRECIPITATION
WILL BE MORE FOCUSED NORTH OF PITTSBURGH AND ACROSS EASTERN OHIO
AS THE VORT LIFTS INTO THAT AREA. WRF SIMULATED GOES-R ABI
SATELLITE IMAGERY HINTS THAT A DRY SLOT WILL MOSTLY DIMINISH
PRECIP FOR LOCATIONS SOUTH AND WEST OF PITTSBURGH OVERNIGHT. 850MB
WARM WEDGE OF AIR WILL BECOME PINCHED OFF AS IT SLIDES INTO NORTH-
CENTRAL PA AND THE COLD POOL ASSOCIATED WITH THE UPPER LOW ADVECT
INTO THE AREA FROM THE SOUTHWEST. WITH THIS IN MIND...SFC TEMPS
ARE CLOSE TO A HRRR/LAMP BLEND...REMAINING IN THE LOWER TO MID 30S
ACROSS THE AREA. IN ADDITION...THE WEDGE PINCHING OFF WILL ALLOW
FOR A WINTRY MIX TO CONTINUE NORTH OF PITTSBURGH AND FOR THE
LAUREL HIGHLANDS/ALLEGHENY FRONT...WITH SNOW BEGINNING TO MIX IN
WITH RAIN SHOWERS SOUTHWEST OF PITTSBURGH BY DAWN. SNOW/SLEET
ACCUMULATIONS WILL BE LESS THAN AN INCH NORTH AND EAST OF
PITTSBURGH WITH ADDITIONAL LIGHT ICE ACCUMULATIONS WHERE TEMPS ARE
SUB-FREEZING.
WEDNESDAY...THE UPPER LOW WILL BECOME MORE ELONGATED AS IT EXTENDS
FROM SOUTHERN MICHIGAN INTO CENTRAL PA. THUS...COLD POOL ALOFT
WILL SUPPORT SNOW SHOWERS MIXING IN WITH RAIN EARLY. RAIN WILL MIX
BACK IN AS 1000-850MB LAYER WARMS ABOVE FREEZING. WITH SURFACE
TEMPS MOSTLY ABOVE FREEZING...THIS WILL LIMIT DAYTIME SNOWFALL
ACCUMULATIONS ACROSS THE AREA DESPITE VORT ENERGY SUPPORTING A
BROAD AREA OF LIFT PUSHING INTO THE AREA EARLY IN THE DAY. HIGH
TEMPS UNDERCUT A MAV/MET BLEND BY 3-5 DEGREES AS CLOUD COVERAGE
LIMITS TEMPS. HIGHS WILL RANGE FROM THE UPPER 30S TO LOWER 40S
ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
MATURE/STACKED AND COLD LOW PRES WL WOBBLE ACROSS THE REGION
THROUGH THURSDAY...AND DIG OFF THE COAST BY FRIDAY ACCORDING TO
THE LATEST MDL SOLNS. SCT TO NMRS SHSN WL THUS CONT TO PLAGUE THE
REGION FOR THE SHORT TERM PD...WITH UPSLOPE COMPONENT OF WIND
ENHANCING SN POTENTIAL IN THE RIDGES.
OVRALL ACCUMULATION POTENTIAL WL BE RETARDED OVR AREAS WHERE
DAYTIME TEMPS RISE ABOVE FREEZING...SO HEADLINE POTENTIAL IS
LIMITED. THE EXCEPTION MAY BE FOR THE RIDGES WHERE PROLONGED SHSN
MAY REQUIRE A COUPLE-DAY ADVISORY. FOR NOW...WL MENTION IN THE
HAZARDOUS WEATHER OUTLOOK AND TASK FUTURE SHIFTS TO MONITOR.
SHORT TERM TEMPS WERE FORECAST CLOSER TO COOLER GFS GUIDANCE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ECMWF AND GFS CONT TO INDICATE DEVELOPMENT OF AN ERN NORTH AMERICAN
TROF FOR THE LONG TERM PD. THE EXTENDED FORECAST THUS CONTINUES
TO FEATURE SUB AVERAGE TEMPS AND NR CLIMO...I.E. CHC POPS
DEPENDANT ON SPPRTG SHRTWV ENERGY FOR THE INTIAL PDS.
SHRTWV RIDGE IN ADVN OF MIDWRN LOW SHOULD REDUCE THOSE POPS BY
MONDAY...BUT THAT REPRIEVE LOOKS TO BE BRIEF AS PCPN FM THAT SYSTEM
IS CURRENTLY TIMED FOR A TUE INITIATION OVR THE UPR OH VALLEY.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
LOW CONFIDENCE FORECAST. AS OF 03Z...PRECIPITATION HAS BECOME
MORE SCATTERED ACROSS TERMINALS. FKL/DUJ MAY REMAIN COLD ENOUGH
FOR SNOW...BUT RAIN AT OTHER LOCATIONS SHOULD BE ALL RAIN. DRY
SLOT MOVING IN FROM WEST VIRGINIA HAS MANAGED TO BRING VFR
CIGS...WHILE FKL/DUJ CURRENTLY REMAIN IFR. FKL/DUJ COULD
EVENTUALLY LIFT...BUT EVEN NEWEST MODEL GUIDANCE STILL SAYS THAT
CONDITIONS SHOULD CURRENTLY BE IFR. THINK THAT CIGS WILL COME BACK
DOWN EVENTUALLY...BUT DO NOT HAVE A GOOD IDEA AT ALL AS TO WHEN
THAT WILL HAPPEN. AT THIS POINT...HAVE BROUGHT CONDITIONS DOWN TO
MVFR AT 06Z...BUT DO NOT HAVE MUCH CONFIDENCE IN THIS TIMING.
MVFR CIGS IN -RA DOMINATE WED...WITH PRECIPITATION EXPECTED TO
REMAIN SNOW AT FKL/DUJ. WITH 00Z TAFS...HAVE ADDED GUSTS TO 15-20
KTS IN ADDITION TO THE SW WINDS AROUND 10 KTS.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
BRIEF IFR RESTRICTIONS ARE POSSIBLE IN MODERATE RAIN OR SNOW
SHOWERS THROUGH FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR PAZ008-
009-015-016.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...TGREEN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
804 PM EST TUE FEB 26 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL PUSH INTO THE AREA OVERNIGHT...BRINGING A
WINTRY MIX OF PRECIPITATION TO THE AREA. COLDER AIR ALOFT WILL
THEN BRING A MIX OF RAIN AND SNOW SHOWERS TO THE AREA FOR THE
REMAINDER OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AN EVENING ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
EXTEND THE WINTER WEATHER ADVISORY NORTHEAST OF PITTSBURGH TO 06Z
AND TO PROLONG THE MENTION OF SLEET AND SNOW MIXING IN WITH RAIN
NORTH OF I-70.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED LOW CENTERED
ACROSS SOUTHERN ILLINOIS. 500MB VORT ENERGY IS SLIDING AROUND THE
LOW AND INTO THE UPPER OHIO VALLEY WHILE DRIER AIR ALOFT BEGINS TO
ADVECT FROM THE SOUTH INTO THE WV APPALACHIANS. 850MB ANALYSIS
INDICATES A WARM WEDGE OF 3-4C EXTENDING FROM NORTHERN WV INTO
SOUTHERN INDIANA COUNTY PENNSYLVANIA WITH A LOCALIZED AREA WITH
TEMPS 0-1C NORTHWEST OF PITTSBURGH. AT THE SURFACE...A 998MB LOW
IS CENTERED ACROSS THE OH/IN BORDER WITH AN OCCLUDED FRONT
EXTENDING FROM THIS FEATURE EASTWARD TO THE MASON-DIXON LINE.
00Z KPIT SOUNDING INDICATES A FREEZING 900-750MB LAYER WITH TEMPS
DROPPING TO -2C IN THE LAYER. ABOVE 750MB...THE MELTING LAYER HAS
WEAKENED...ONLY AROUND 1C. THIS SOUNDING HAS BEEN CONFIRMED FROM
DUAL POLARIZATION RADAR REFLECTIVITY...CORRELATION
COEFFICIENT...AND DIFFERENTIAL REFLECTIVITY WHICH HAVE INDICATED
AREAS ARE OF PREDOMINATELY SLEET WITH SNOW MIXING IN FOR THE
PITTSBURGH METRO AND AREAS NORTHWARD THIS EVENING. ALONG THE I-80
CORRIDOR...WET BULBING BROUGHT TEMPS DOWN TO NEAR FREEZING AND
THEY REMAIN STEADY THERE WITH AN EASTERLY LOW-LEVEL FLOW.
THUS...POCKETS OF FREEZING RAIN HAVE BEEN REPORTED THERE. THE
LAUREL HIGHLANDS AND ALLEGHENY FRONT HAVE CONTINUED TO HAVE MOSTLY
FREEZING RAIN IN THE WARM WEDGE...ALTHOUGH PRECIPITATION IS BECOMING
LIGHTER THERE AS A DRY SLOT FINALLY WORKS INTO THE AREA.
OVERNIGHT...THE RAP/WRF-NMM INDICATE A CLOSED LOW WILL SLIDE
NORTHEASTWARD ALONG THE OHIO RIVER...BECOMING CENTERED OVER THE
NORTHERN PANHANDLE OF WV BY 12Z WEDNESDAY. MEANWHILE...THE SURFACE
LOW WILL PUSH NORTHWARD INTO SOUTHERN MICHIGAN WITH THE OCCLUDED
FRONT EDGING SLOWLY NORTHEASTWARD INTO THE AREA. PRECIPITATION
WILL BE MORE FOCUSED NORTH OF PITTSBURGH AND ACROSS EASTERN OHIO
AS THE VORT LIFTS INTO THAT AREA. WRF SIMULATED GOES-R ABI
SATELLITE IMAGERY HINTS THAT A DRY SLOT WILL MOSTLY DIMINISH PRECIP
FOR LOCATIONS SOUTH AND WEST OF PITTSBURGH OVERNIGHT. 850MB WARM
WEDGE OF AIR WILL BECOME PINCHED OFF AS IT SLIDES INTO NORTH-
CENTRAL PA AND THE COLD POOL ASSOCIATED WITH THE UPPER LOW ADVECT
INTO THE AREA FROM THE SOUTHWEST. WITH THIS IN MIND...SFC TEMPS
ARE CLOSE TO A HRRR/LAMP BLEND...REMAINING IN THE LOWER TO MID 30S
ACROSS THE AREA. IN ADDITION...THE WEDGE PINCHING OFF WILL ALLOW
FOR A WINTRY MIX TO CONTINUE NORTH OF PITTSBURGH AND FOR THE
LAUREL HIGHLANDS/ALLEGHENY FRONT...WITH SNOW BEGINNING TO MIX IN
WITH RAIN SHOWERS SOUTHWEST OF PITTSBURGH BY DAWN. SNOW/SLEET
ACCUMULATIONS WILL BE LESS THAN AN INCH NORTH AND EAST OF
PITTSBURGH WITH ADDITIONAL LIGHT ICE ACCUMULATIONS WHERE TEMPS ARE
SUB-FREEZING.
WEDNESDAY...THE UPPER LOW WILL BECOME MORE ELONGATED AS IT EXTENDS
FROM SOUTHERN MICHIGAN INTO CENTRAL PA. THUS...COLD POOL ALOFT
WILL SUPPORT SNOW SHOWERS MIXING IN WITH RAIN EARLY. RAIN WILL MIX
BACK IN AS 1000-850MB LAYER WARMS ABOVE FREEZING. WITH SURFACE
TEMPS MOSTLY ABOVE FREEZING...THIS WILL LIMIT DAYTIME SNOWFALL
ACCUMULATIONS ACROSS THE AREA DESPITE VORT ENERGY SUPPORTING A
BROAD AREA OF LIFT PUSHING INTO THE AREA EARLY IN THE DAY. HIGH
TEMPS UNDERCUT A MAV/MET BLEND BY 3-5 DEGREES AS CLOUD COVERAGE
LIMITS TEMPS. HIGHS WILL RANGE FROM THE UPPER 30S TO LOWER 40S
ACROSS MUCH OF THE AREA.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
MATURE/STACKED AND COLD LOW PRES WL WOBBLE ACROSS THE REGION
THROUGH THURSDAY...AND DIG OFF THE COAST BY FRIDAY ACCORDING TO
THE LATEST MDL SOLNS. SCT TO NMRS SHSN WL THUS CONT TO PLAGUE THE
REGION FOR THE SHORT TERM PD...WITH UPSLOPE COMPONENT OF WIND
ENHANCING SN POTENTIAL IN THE RIDGES.
OVRALL ACCUMULATION POTENTIAL WL BE RETARDED OVR AREAS WHERE
DAYTIME TEMPS RISE ABOVE FREEZING...SO HEADLINE POTENTIAL IS
LIMITED. THE EXCEPTION MAY BE FOR THE RIDGES WHERE PROLONGED SHSN
MAY REQUIRE A COUPLE-DAY ADVISORY. FOR NOW...WL MENTION IN THE
HAZARDOUS WEATHER OUTLOOK AND TASK FUTURE SHIFTS TO MONITOR.
SHORT TERM TEMPS WERE FORECAST CLOSER TO COOLER GFS GUIDANCE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ECMWF AND GFS CONT TO INDICATE DEVELOPMENT OF AN ERN NORTH AMERICAN
TROF FOR THE LONG TERM PD. THE EXTENDED FORECAST THUS CONTINUES
TO FEATURE SUB AVERAGE TEMPS AND NR CLIMO...I.E. CHC POPS
DEPENDANT ON SPPRTG SHRTWV ENERGY FOR THE INTIAL PDS.
SHRTWV RIDGE IN ADVN OF MIDWRN LOW SHOULD REDUCE THOSE POPS BY
MONDAY...BUT THAT REPRIEVE LOOKS TO BE BRIEF AS PCPN FM THAT SYSTEM
IS CURRENTLY TIMED FOR A TUE INITIATION OVR THE UPR OH VALLEY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
LOW CONFIDENCE FORECAST. AS OF 00Z...DRY SLOT OF PRECIPITATION IS
MOVING INTO SOUTHWEST PENNSYLVANIA...WHICH SHOULD GIVE MOST
TERMINALS AT LEAST A TEMPORARY BREAK IN PRECIP. HOWEVER...WHERE
PRECIPITATION REMAINS...ALL PRECIPITATION TYPES HAVE BEEN REPORTED.
HAVE STUCK WITH RAIN IN THE TAFS THROUGH MUCH OF THE NIGHT EXCEPT AT
DUJ...WHERE FREEZING RAIN MAY PERSIST. DRY SLOT COULD ALSO WRECK
HAVOC ON CEILING FORECASTS TONIGHT. GUIDANCE INDICATES IFR/LIFR
CONDITIONS DEVELOPING...WHILE VFR CIGS ARE MOVING IN WITH THE DRY
SLOT. HAVE SPLIT THE BALANCE AT THIS POINT...GENERALLY KEEPING ALL
CIGS MVFR. AS TEMPERATURES DECREASE...HAVE DROPPED FKL/DUJ TO SNOW
WITH LIFR CIGS.
MVFR CIGS IN -RA DOMINATE WED...WITH PRECIPITATION EXPECTED TO
REMAIN SNOW AT FKL/DUJ. WITH 00Z TAFS...HAVE ADDED GUSTS TO 15-20
KTS IN ADDITION TO THE SW WINDS AROUND 10 KTS.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
BRIEF IFR RESTRICTIONS ARE POSSIBLE IN MODERATE RAIN OR SNOW
SHOWERS THROUGH FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR PAZ008-
009-015-016-023.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ074-076.
WV...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR WVZ023-
041.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...TGREEN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
653 PM EST TUE FEB 26 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 428 PM EST TUE FEB 26 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PRONOUNCED SPLIT FLOW
CONTINUING ACROSS NAMERICA. IN WHAT HAS BEEN A VERY ACTIVE SRN
STREAM RECENTLY...A WELL-DEFINED MID LEVEL LOW IS MOVING ENE INTO
THE LWR OHIO VALLEY. SRN STREAM RIDGING AHEAD OF FEATURE EXTENDS
FROM JUST OFF THE SE COAST TO SRN NEW ENGLAND AND THEN BACK INTO THE
UPPER LAKES. WITH NRN STREAM WELL N OF HERE...ARCTIC AIR HAS
RETREATED INTO NRN CANADA. CLOSER TO HOME...PESKY STRATOCU HAS
CONTINUED TO PLAGUE UPPER MI TODAY. HOWEVER...ROUGHLY THE W THIRD OF
THE FCST AREA HAS ENJOYED MOSTLY SUNNY SKIES FOR AT LEAST A PORTION
OF THE DAY. THE POCKET OF MOSTLY SUNNY SKIES CURRENTLY OVER THE W IS
SHOWING SIGNS OF EXPANDING EASTWARD AS STRONGER DAYTIME HEATING
UNDER HIGHER LATE FEB SUN ANGLE IS WORKING ON LOWER ALBEDO FORESTED
TERRAIN TO RAISE MIXED LAYER AND THUS MIX OUT THE SHALLOW MOIST
LAYER.
DURING THE SHORT TERM...MAIN FCST ISSUE WILL REVOLVE AROUND
NORTHWARD PROGESS OF A WEAKENING PCPN SHIELD SPREADING N AROUND SRN
STREAM MID LEVEL LOW AS IT TRACKS INTO THE UPPER OHIO VALLEY/LWR
LAKES REGION. EARLY ON...LOW CLOUDS WILL CONTINUE TO PRESENT SOME
ISSUES. CLEARING MAY CONTINUE TO EXPAND E FROM WRN UPPER MI OVER THE
NEXT COUPLE OF HRS...BUT WITH LOSS OF DAYTIME HEATING...STRATOCU
WILL PROBABLY TEND TO SPREAD BACK INTO THE AREAS THAT HAVE
CLEARED...ESPECIALLY IF THE STRATOCU TO THE E AND NE DOES NOT BREAK
UP DURING THE LATE AFTN/EVENING. LATEST VIS SATELLITE IMAGERY DOES
SHOW STRATOCU THINNING OVER ERN LAKE SUPERIOR...SO THERE MAY YET BE
SOME MORE CLEARING DURING THE EVENING. WILL BE A TREND TO MONITOR.
WHILE CLOUDS WILL AGAIN MAKE OR BREAK TEMP FCST...THERE WILL LIKELY
NOT BE AS GREAT OF A TEMP SPREAD TONIGHT AS IN PREVIOUS NIGHTS BTWN
AREAS WITH CLOUDS AND AREAS WITH LESS CLOUD SINCE INCREASING
GRADIENT WINDS WILL LIMIT RADIATIONAL COOLING. TRENDED TEMPS TOWARD
RAW MODEL GUIDANCE WHICH PUTS MIN TEMPS GENERALLY IN THE MID/UPPER
20S.
AS FOR PCPN...THE STRONG ISENTROPIC ASCENT COMPONENT TO PCPN SHIELD
SPREADING N INTO SRN WI/SRN MI ATTM WILL GRADUALLY FADE WITH TIME AS
THE ZONE OF STRONG ASCENT TRANSLATES EASTWARD...RESULTING IN ZONE OF
HEAVIEST PCPN SHIFTING E TOWARD THE LWR LAKES/SRN NEW ENGLAND
TONIGHT/WED MORNING. THUS...A DECAYING SHIELD OF PCPN WILL BE
LIFTING TOWARD UPPER MI TONIGHT/WED MORNING. RECENT MODEL TRENDS
GENERALLY POINT TOWARD A MORE AGGRESSIVE PUSH OF LIGHT SNOW INTO
UPPER MI. GIVEN THE STRONG NORTHWARD PUSH OF PCPN THRU LWR MI ATTM
AND THE LACK OF A LAYER OF VERY DRY AIR AT THE LOWER LEVELS TO THE N
ACROSS UPPER MI...HAVE OPTED TO TREND PCPN CHC SLIGHTLY FARTHER N
THAN PREVIOUS FCST TO ROUGHLY A KERY/KSAW/KIMT LINE AND RAISED POPS
TO HIGH CHC ALONG LAKE MI. WITH 850MB TEMPS NO LWR THAN -8/-9C...
IT`S VERY UNLIKELY THAT ANY LES WILL DEVELOP OFF LAKE SUPERIOR UNDER
STRONG NE CYCLONIC FLOW WED. IF SHIELD OF LIGHT SYNOPTIC SNOW DOES
REACH LAKE SUPERIOR...THEN A LITTLE LAKE COMPONENT WILL BE THERE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 428 PM EST TUE FEB 26 2013
LITTLE CHANGES TO THE LONG TERM FROM 24 HOURS AGO...WITH THE
MAIN ITEM OF DIFFERENCE A SLIGHT WOBBLE TO THE NORTHWEST WITH THE
SYSTEM CURRENTLY MOVING THROUGH THE MID MISSISSIPPI VALLEY THAT
WILL MOVE THROUGH THE LOWER GREAT LAKES. THIS SLIGHT
ADJUSTMENT...PUSHES THE PRECIPITATION A TOUCH FARTHER INLAND FROM
LAKE MICHIGAN. BUT AS THE LONG TERM PERIOD BEGINS...THE LOW WILL
START IT/S EASTWARD SHIFT TOWARDS NEW YORK AND DIMINISH THE SNOW
ALONG THE LAKE MICHIGAN SHORELINE.
ATTENTION THEN TURNS TO THE AMOUNT OF MOISTURE AND COLD AIR IN THE
LOWER LEVELS TO SUPPORT LAKE ENHANCED AND UPSLOPE SNOW SHOWERS.
LATEST TRENDS IN THE MOISTURE AND COLD AIR /850MB TEMPERATURES
FALLING FROM -9C AT WEDNESDAY NIGHT TO -13C BETWEEN 900-850MB BY
THURSDAY AFTERNOON/ LEADS TO GREATER CONFIDENCE IN SCATTERED SNOW
SHOWERS OCCURRING FOR LOCATIONS NEAR LAKE SUPERIOR FROM PICTURED
ROCKS AND WESTWARD. INVERSION HEIGHTS AROUND 3-4KFT SHOULD KEEP THE
INTENSITY IN CHECK AND HELPS KEEP LAKE INDUCED CAPES BELOW 200
J/KG. THUS...WILL BUMP POPS UP 5-10 PERCENT INTO HIGHER END CHANCE
CATEGORY. SNOWFALL AMOUNTS SHOULD BE FAIRLY LIGHT...SINCE CLOUD
DEPTH IS FAIRLY LIMITED. WITH THE INITIAL CLOUD LAYER MAINLY BEING
BELOW THE DGZ WEDNESDAY NIGHT...WOULD EXPECT FLAKES TO BE FAIRLY
SMALL. BUT AS THE COLDER AIR ARRIVES...IT DOES ATTEMPT TO PUSH THE
CLOUD LAYER INTO THE DGZ AND HELP SNOW RATIOS. BUT WITH THE LIMITED
CLOUD DEPTH/MOISTURE TO WORK WITH...WOULDN/T EXPECT MUCH MORE THAN
AN INCH OR TWO OF TOTAL ACCUMULATION BY THE TIME IT STARTS WINDING
DOWN ON FRIDAY. THE HIGHEST AMOUNTS WILL BE IN THE FAVORED UPSLOPE
LOCATIONS WITH NORTHEAST WINDS...ESPECIALLY IN/NEAR THE HURON
MOUNTAINS WHICH COULD APPROACH 3 INCHES.
A BUILDING CANADIAN HIGH OVER HUDSON BAY WILL SLIDE A RIDGE SOUTH
INTO THE UPPER GREAT LAKES REGION FRIDAY AND IT WILL REMAIN INTO THE
FIRST PART OF THE NEXT WEEK. THIS WILL WORK TO REDUCE THE INVERSION
HEIGHTS TO 2KFT AND SHOULD BRING AN END TO THE LAKE ENHANCED/EFFECT
BY FRIDAY NIGHT. WILL GO WITH PARTLY CLOUDY SKIES THROUGH THE
WEEKEND...BUT THERE IS SOME CONCERN THAT THERE COULD BE LINGERING
LOW CLOUDS BELOW THE STRENGTHENING INVERSION DURING THAT TIME.
MAIN QUESTION FOR NEXT WEEK WILL BE THE LOCATION OF A SHORTWAVE
CUTTING THROUGH THE UPPER RIDGE OVER THE WESTERN CONUS AND IT/S
INFLUENCE ON THE UPPER TROUGH ON THE EAST COAST. 00Z ECMWF HOLDS
THE TROUGH OVER THE AREA...WHILE THE GFS TRIES TO PUSH THE RIDGE
OVER THE AREA ON MONDAY. THIS HAS THE POTENTIAL FOR WEAKENING THE
SURFACE RIDGE AND PUSHING SOME PRECIPITATION INTO THE AREA ON THE
EAST SIDE OF A LOW MOVING THROUGH CENTRAL PLAINS OR UPPER
MISSISSIPPI VALLEY. WILL RESPECT THE CONSISTENCY SHOWN IN THE ECMWF
OVER THE LAST SEVERAL DAYS AND TRY TO KEEP MUCH OF THE AREA DRY.
HIGH TEMPERATURES ARE STILL LOOKING TO BE BELOW NORMAL THROUGH THE
LONG TERM PERIOD. LOOKING AT THE LONGER RANGE FORECASTS /EVEN THOUGH
SKILL IS FAIRLY LIMITED/...NOT TOO MANY SIGNS OF SPRING FOR THE
FIRST WEEK OR TWO OF MARCH. GFS/ECMWF ENS MEANS ARE SHOWING 850MB
TEMPS BELOW NORMAL THROUGH THE FIRST WEEK AND GFS ENS 500MB MEAN
HEIGHTS ARE SHOWING A TROUGH REMAINING OVER THE EASTERN CONUS
THROUGH THE MIDDLE OF MARCH. AFTER BEING SPOILED BY WARM
MARCH WEATHER IN 2010/2012...ITS LOOKING LIKE MARCH WILL
BE MORE TRADITIONAL TEMPERATURE WISE. UNFORTUNATELY FOR SOME OF THE
LOCATIONS OF CENTRAL UPPER MICHIGAN THAT HAVE SEEN PROLONGED
DRYNESS...THIS PATTERN WON/T BE SUPPORTIVE OF ANY SIGNIFICANT
PRECIPITATION AND MAINLY JUST LIGHT PRECIPITATION FROM CLIPPERS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 652 PM EST TUE FEB 26 2013
DEVELOPING UPSLOPE NE FLOW AT KIWD SHOULD LEAD TO MVFR CLOUDS MOVING
BACK IN LATE TONIGHT AFT 09Z AND THEN PERSISTING THROUGH WEDNESDAY.
DEVELOPING DOWNSLOPE NE FLOW AT KCMX SHOULD LEAD TO MVFR DECK
DISSIPATING LATER THIS EVENING. CONTINUING NE FLOW SHOULD MAINTAIN
VFR CONDITIONS THRU WEDNESDAY WITH SOME INCREASE IN MID-LVL CLOUDS
EXPECTED WITH APPROACH OF MOISTURE FM SYSTEM OVER THE LOWER LAKES.
NE UPSLOPE FLOW SHOULD MAINTAIN MVFR CONDITIONS AT KSAW THROUGH THE
FCST PD. TIGHTENING PRES GRADIENT WILL LEAD TO AN INCREASE IN NE
WIND GUSTS AOA 25 KTS ON WEDNESDAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 428 PM EST TUE FEB 26 2013
TIGHTENING PRES GRADIENT BTWN HIGH PRES TO THE N AND NW AND LOW PRES
TRACKING THRU THE LWR OHIO VALLEY TO LWR LAKES WILL RESULT IN
NORTHEASTERLY WINDS ACROSS LAKE SUPERIOR INCREASING TO 20-30KT
TONIGHT THRU WED. MIGHT SEE A FEW GALE FORCE GUSTS WED AFTN OVER THE
E HALF. EVEN THOUGH THE LOW CONTINUES TO MOVE E THU...THE HIGH
BUILDING TOWARD THE AREA FROM N WILL MAINTAIN A TIGHT PRES
GRADIENT...RESULTING IN CONTINUED 20-30KT WINDS WITH SOME GALE FORCE
GUSTS POSSIBLE OVER THE E HALF THRU THU MORNING. WINDS WILL THEN
VERY SLOWLY DIMINISH FROM W TO E FRI/SAT AS THE HIGH PRES MOVES
CLOSER...BUT IT WILL PROBABLY BE SAT BEFORE WINDS DROP BLO 20KT
ACROSS THE ENTIRE LAKE. THE PERIOD OF STRONG WINDS WED NIGHT THRU
FRI WILL ALSO BRING THE POTENTIAL FOR FREEZING SPRAY. LIGHT WINDS
UNDER 10KT ARE EXPECTED SUN AS SFC HIGH PRES RIDGE WILL EXTEND FROM
HUDSON BAY S ACROSS LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 PM EST MON FEB 25 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 413 PM EST MON FEB 25 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW PATTERN
ACROSS NAMERICA. IN THE SRN STREAM...A WELL-DEFINED MID LEVEL LOW
WAS OVER N TX. IN THE NRN STREAM...A SHORTWAVE TROF EXTENDS FROM
HUDSON BAY TO THE UPPER MISSISSIPPI VALLEY. SOME FLURRIES HAVE BEEN
NOTED IN WI TODAY IN AN AREA OF WEAK ISENTROPIC ASCENT. SOME OF
THOSE FLURRIES MAY HAVE SLIPPED INTO SCTNRL UPPER MI THIS AFTN
ALTHOUGH NO REPORTS HAVE BEEN NOTED. OTHERWISE...MOSTLY CLOUDY SKIES
HAVE BEEN THE RULE TODAY...THOUGH THERE WAS A PERIOD OF MOSTLY SUNNY
SKIES FOR A TIME EARLIER OVER THE FAR W AND NW.
ALTHOUGH THE SHORT TERM PORTION OF THE FCST WILL FEATURE TRANQUIL
WEATHER...CLOUDS AND TEMPS WILL OFFER SOME CHALLENGING ASPECTS TO
THE FCST. UNDER WEAK ISENTROPIC ASCENT...WILL MAINTAIN A MENTION OF
A FEW FLURRIES INTO THE EVENING HRS OVER THE SRN PORTION OF THE FCST
AREA. CLOUD FCST IS NOT CERTAIN AT ALL AND THAT OPENS THE DOOR TO
BIG TEMP BUST POTENTIAL TONIGHT. UNDER LIGHT SW FLOW INTO THE
EVENING...MULTI-LAYERED CLOUDS TO THE SW SHOULD AFFECT MUCH OF THE
FCST AREA. OVERNIGHT...LOW-LEVEL WIND FIELDS BECOME VERY LIGHT WITH
A TREND TO LIGHT EASTERLY LATE WHICH SUGGESTS LITTLE ADVECTION OF
DRIER AIR. THUS...IT WOULD SEEM THAT MUCH OF THE AREA WILL SEE
MOSTLY CLOUDY SKIES TONIGHT. HOWEVER...THE PROXIMITY OF CLEAR SKIES
JUST TO THE W SUGGESTS THE WRN FCST AREA MAY HAVE THE BEST SHOT OF
SEEING A PERIOD OF PARTLY CLOUDY AND POSSIBLY CLEAR SKIES TONIGHT.
ALL IN ALL...THERE IS VERY LOW CONFIDENCE ON SKY CONDITION THRU THE
NIGHT. WITH LIGHT/CALM WINDS AT THE SFC...TEMPS WILL FALL
SIGNIFICANTLY IN SOME AREAS IF SKIES BECOME CLEAR/PARTLY CLOUDY FOR
A TIME. THIS COULD ALSO LEAD TO SOME FOG DEVELOPMENT. AT THIS
POINT...WILL PLAY IT CONSERVATIVE UTILIZING A CONSENSUS APPROACH TO
TEMPS...BUT WILL GO WITH LOWEST MIN TEMPS OVER THE W (MID TEENS)
WHERE IT APPEARS THERE IS A BETTER SHOT OF SEEING LESS CLOUDS FOR AT
LEAST A PORTION OF THE NIGHT. COULD EASILY SEE TEMPS FALL INTO THE
SINGLE DIGITS IF ANY LOCATIONS END UP CLEAR FOR A FEW HRS.
E TO NE WINDS WILL DEVELOP TUE AS UPPER MI FALLS INTO THE NRN
PERIPHERY OF THE CIRCULATION AROUND SRN STREAM LOW. WINDS WILL BE
STRONGEST IN THE MENOMINEE AREA AS A STIFF NE WIND WILL BE THE RULE
IN THE AFTN DUE TO COASTAL CONVERGENCE/FUNNELING DOWN THE BAY.
STRATOCU SHOULD TEND TO BREAK UP AS MODELS SUGGEST SOME DRYING...
BUT THE LWR CLOUDS WILL PROBABLY HANG ON LONGEST WHERE EASTERLY
WINDS UPSLOPE. WHERE LOW CLOUDS SCATTER OUT OR CLEAR...THERE SHOULD
BE A FAIR AMOUNT OF SUNSHINE THRU ONLY SOME HIGH CLOUDS. EXPECT MAX
TEMPS IN THE 30S...COOLEST (LOW 30S) AT LOCATIONS WHERE WINDS ARE
OFF THE LAKES AND IN THE UPSLOPE AREAS. TEMPS COULD RISE TO NEAR 40
IN LOCATIONS THAT SEE DOWNSLOPING WITH EASTERLY WINDS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 413 PM EST MON FEB 25 2013
THREE SHORTWAVES WILL INFLUENCE THE WEATHER FOR MUCH OF THE EASTERN
HALF OF THE CONUS OVER THE NEXT SEVERAL DAYS AND SETUP THE WEATHER
PATTERN HEADING INTO THE FIRST WEEK OF MARCH.
THE FIRST WAVE IS CURRENTLY SPINNING IN THE SOUTHERN PLAINS AND WILL
EJECT TOWARDS THE LOWER GREAT LAKES ON TUESDAY INTO TUESDAY
NIGHT...WHILE THE NEXT WAVE DIVES SOUTHEAST ACROSS THE CENTRAL
ROCKIES. MODELS HAVE BECOME MUCH MORE CONSISTENT WITH THIS SYSTEM IN
THE LAST 24 HOURS...AS THERE WERE DIFFERENCES IN THE INTERACTION
BETWEEN THE FIRST AND SECOND WAVES...WITH THE MERGER AND NORTHWARD
EXTENT. EVERYTHING SEEMS TO HAVE COME INTO AGREEMENT WITH THE
CONSISTENT ECMWF ON A MORE SOUTHERN TRACK THAT JUST BRUSHES THE FAR
SOUTHEAST PART OF UPPER MICHIGAN /NEAR LAKE MICHIGAN/ WITH LIGHT
SNOW LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. ANY SLIGHT
DIFFERENCES IN THE NORTHWEST EXTENT OF THE TRACK WILL NOT ONLY
AFFECT THE SNOW NEAR LAKE MICHIGAN...BUT ALSO THE POTENTIAL FOR
LIGHT LAKE ENHANCEMENT OR UPSLOPE PRECIPITATION WITH THE
NORTH-NORTHEAST FLOW AROUND THE LOW. WITH THE LIMITED COLD AIR IN
PLACE AT THIS TIME...IT LOOKS LIKE 850MB TEMPS ON WEDNESDAY ARE ONLY
AROUND -5C...SO DELTA-T VALUES ARE FAIRLY MARGINAL. WHEN COMBINING
THAT WITH LIMITED MOISTURE...UNLESS THE FARTHER NW 06Z NAM IS
CORRECT...WOULDN/T THINK AREAS AWAY FROM LAKE MICHIGAN WOULD SEE
MUCH MORE THAN LOW CLOUDS AND UPSLOPE FLURRIES OR LIGHT SNOW OVER
THE NORTH CENTRAL ON WEDNESDAY PENDING ENOUGH MOISTURE. MODELS ARE
IN BETTER AGREEMENT ON LOW LEVEL MOISTURE MOVING IN ON WEDNESDAY
NIGHT AS THE LOW SHIFTS EAST INTO NEW YORK. THIS IS IN RESPONSE TO
ADDITIONAL MOISTURE ASSOCIATED WITH A NORTHERN STREAM SHORTWAVE
MOVING THROUGH SOUTHERN CANADA. THIS WILL LIKELY LEAD TO THE BEST
POTENTIAL FOR PRECIPITATION FOR AREAS NEAR LAKE SUPERIOR WEDNESDAY
NIGHT INTO THURSDAY. 850MB TEMPS ARE STILL MARGINAL THROUGH THIS
PERIOD...BUT DO DROP TO -10C. WITH THE MARGINAL DELTA-T VALUES AND
AN INVERSION HEIGHT SITTING AROUND 4KFT...THINKING THAT THE LIGHT
SNOW SHOWERS WILL REMAIN IN THE NORTH-NORTHEAST FAVORED LOCATIONS OF
NORTHERN UPPER MICHIGAN. STRONGEST SHOWERS SHOULD OCCUR OVER THE
HIGHER TERRAIN OF NORTH CENTRAL UPPER MICHIGAN...WHERE UPSLOPE FLOW
WILL AID THE FORCING SOME. WILL CONTINUE TO MENTION SLIGHTS AND LOW
CHANCE POPS IN THESE AREAS INTO THURSDAY NIGHT.
MEANWHILE...THE THIRD MAIN SHORTWAVE WILL BE DIVING SOUTHEAST
THROUGH THE ROCKIES ON WEDNESDAY NIGHT AND THURSDAY AND AMPLIFY THE
UPPER TROUGH OVER THE EASTERN CONUS. THIS WILL LEAD THE UPPER GREAT
LAKES INTO A COLDER THAN NORMAL PERIOD FOR THE LAST DAY OF FEBRUARY
AND THE FIRST WEEK OF MARCH. WHILE THIS BRINGS GRADUALLY COLDER AIR
/925-900MB TEMPS FALLING TOWARDS -12 TO -14C/...IT WILL ALSO PUSH A
HIGH PRESSURE RIDGE OVER THE AREA FROM A HIGH CENTERED OVER HUDSON
BAY. THIS SUBSIDENCE WILL WORK TO LOWER THE INVERSION HEIGHTS BELOW
3KFT BY FRIDAY MORNING. THEREFORE...WOULD JUST EXPECT LINGERING
LOW CLOUDS AND AN ISOLATED SNOW SHOWER FOR FRIDAY INTO SATURDAY
OVER LOCATIONS NEAR LAKE SUPERIOR. THERE ARE SOME DIFFERENCES IN
THE WIND DIRECTION ROTATING AROUND THE HIGH...BUT WILL MAINLY FOCUS
THE SLIGHT CHANCES OVER THE NORTH CENTRAL.
DIFFERENCES ARRIVE HEADING INTO THE SECOND HALF OF THE WEEKEND WITH
THE HANDLING OF A SHORTWAVE DROPPING THROUGH ON THE BACK SIDE OF
THE RIDGE OVER THE WESTERN CONUS. THE 00Z ECMWF KEEPS THE RIDGE
FARTHER TO THE WEST BEHIND THE SHORTWAVE...WHILE THE 12Z GFS PUSHES
IT INTO THE UPPER GREAT LAKES. DEPENDING ON THE SOLUTION...THIS
WILL EITHER KEEP THE AREA UNDER THE SURFACE RIDGE INTO THE FIRST
PART OF NEXT WEEK OR HAVE THE AREA INFLUENCED BY THE NEXT CLIPPER
SYSTEM APPROACHING FOR MONDAY. WILL GO WITH THE PERSISTENT HIGH AND
DRIER SOLUTION INTO MONDAY.
AFTER A FAIRLY ACTIVE PERIOD FOR THE LAST COUPLE OF WEEKS OF
FEBRUARY...IT/S LOOKING LIKE MARCH WILL COME IN LIKE A LAMB FOR
MUCH OF THE UPPER GREAT LAKES REGION. FORTUNATELY...THIS ACTIVE
PERIOD BROUGHT THE AREA CLOSER TO NORMAL SNOWFALL...ALTHOUGH SOME
LOCATIONS ARE STILL BELOW NORMAL ON SNOWFALL /OUR OFFICE/ AND SNOW
WATER EQUIVALENT /MICHIGAMME RIVER BASIN/. BUT LOOKING AT MODEL RUN
QPF...THE NEXT 10 DAYS DON/T APPEAR TO BE TOO PROMISING FOR
ADDITIONS TO THE SNOW PACK. 00Z ECMWF ONLY SHOWS 10 DAY ACCUMULATION
OF 0.02-0.08 INCH FOR THE ENTIRE CWA. 00Z GFS FOR THE
SIMILAR PERIOD KEEPS VALUES UNDER 0.25 OF AN INCH...WITH MUCH OF
THAT COMING FROM THE SYSTEM BRUSHING THE AREA ON WEDNESDAY AND
THURSDAY. ON THE POSITIVE SIDE...THE EXISTING SNOWPACK WILL REMAIN
IN PLACE AS TEMPERATURES TREND TOWARDS A COOLER THAN NORMAL PERIOD
FOR THE AREA FRIDAY INTO THE NEXT WORK WEEK /HIGHS IN THE 20S AND
LOWS IN THE SINGLE DIGITS ABOVE ZERO/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1237 PM EST MON FEB 25 2013
VFR CONDITIONS SHOULD PREVAIL THRU THE FCST PERIOD AT KIWD/KCMX...
THOUGH PROXIMITY OF LOWER CIGS JUST TO THE S AND SW MAY RESULT IN
MVFR CIGS DEVELOPING AT KIWD AND PERHAPS AT KCMX THIS AFTN/EVENING.
SHOULD SKIES CLEAR TONIGHT...FOG AND POSSIBLE IFR CONDITIONS COULD
DEVELOP AT KIWD/KCMX. AT KSAW...HIGH MVFR CIGS ARE LIKELY TO PREVAIL
INTO THE EVENING GIVEN UPSTREAM MVFR CIGS. IF CLOUDS SCATTER OUT
LATER TONIGHT...IFR CONDITIONS COULD ALSO DEVELOP AT KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 413 PM EST MON FEB 25 2013
ALTHOUGH HIGH PRES WILL BE DEPARTING...WINDS WILL REMAIN UNDER 20KT
PROBABLY THRU TUE AFTN. THEREAFTER...TIGHTENING PRES GRADIENT BTWN
HIGH PRES TO THE N AND NW AND LOW PRES TRACKING THRU THE LOWER OHIO
VALLEY TO LOWER LAKES TUE/WED WILL RESULT IN NORTHEASTERLY WINDS
INCREASING TO 20-30KT TUE NIGHT THRU WED. MIGHT SEE A FEW GALE FORCE
GUSTS WED OVER THE E HALF. EVEN THOUGH THE LOW CONTINUES TO MOVE E
THU...THE HIGH BUILDING TOWARD THE AREA FROM N WILL MAINTAIN A TIGHT
PRES GRADIENT...RESULTING IN CONTINUED 20-30KT WINDS WITH SOME
GALE FORCE GUSTS POSSIBLE OVER THE E HALF. WINDS WILL THEN VERY
SLOWLY DIMINISH FROM W TO E FRI/SAT AS THE HIGH PRES MOVES CLOSER...
BUT IT WILL PROBABLY BE SAT BEFORE WINDS DROP BLO 20KT ACROSS THE
ENTIRE LAKE. ALONG WITH THE PERIOD OF STRONGER WINDS MID
WEEK...FREEZING SPRAY IS ALSO EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1239 PM EST MON FEB 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM EST MON FEB 25 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW
DOMINATING THE FLOW OVER NAMERICA. RDG IN THE NRN BRANCH IS PRESENT
FM JAMES BAY INTO THE UPR GRT LKS TO THE W OF DEPARTING CLOSED LO IN
SE CANADA/NEW ENGLAND...AND A SFC HI PRES RDG EXTENDS FM NE ONTARIO
THRU ECENTRAL UPR MI INTO THE UPR MIDWEST. WITH DRY AIR AOA H8 AS
SHOWN ON 00Z APX/GRB RAOBS AND LARGER SCALE SUBSIDENCE UNDER THE
RDG...THERE IS NO PCPN IN THE AREA. EVEN LES IS ABSENT WITH LLVL
ACYC FLOW AND H85 TEMPS -6C AT INL AND GRB. DESPITE PASSAGE OF SFC
RDG AXIS...QUITE A BIT OF LO CLD LINGERS WITH SOME MSTR/RELATIVELY
HI SFC DEWPTS TRAPPED BLO SUBSIDENCE INVRN H825-875 SHOWN ON THE 00Z
APX/GRB RAOBS. SOME CLRG HAS OCCURRED OVER THE W AND NEAR THE WI
BORDER INTO NE MN/NRN WI...WHERE SOME LLVL DRY AIR SHOWN ON THE 00Z
GRB/MPX RAOBS HAS SHIFTED TO THE N. WHERE SKIES HAVE CLRD...TEMPS
FELL OFF SHARPLY IN THE PRESENCE OF NEAR CALM WINDS. SOME PATCHY
FOG/ST HAS ALSO DVLPD...SO THE CLRG HOLES ARE IN SOME CASES SHORT
LIVED. ALTHOUGH THERE ARE MORE HOLES IN THE LO CLDS OVER FAR NRN
WI/NE MN...MORE LO/MID CLDS ARE STREAMING NEWD INTO CNTRL MN/WI IN
THE LLVL SW FLOW BTWN RDG AXIS OVER UPR MI AND LO PRES TROF
EXTENDING FM LK WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH PAIR OF
NRN BRANCH DISTURBANCES. A POTENT DISTURBANCE IN THE THE SRN BRANCH
IS PRESENT OVER THE SRN ROCKIES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE TRICKY CLD TRENDS/IMPACT ON
TEMPS.
DESPITE SOME DIURNAL HEATING FM INCRSG SUN ANGLE AND SW FLOW ON THE
BACK SIDE OF HI PRES THAT WL ELIMINATE ANY LK SUP INFLUENCE AND
ADVECT SOME DRIER AIR THAT HAS CAUSED CLRG OVER NW WI...RECENT
TRENDS INDICATE LO CLDS MIGHT PROVE QUITE RESILIENT OVER THE CWA
WITH MORE MORE LO CLDS TENDING TO FORM OVER NRN WI. THE WINDOW FOR
CLRG WL BE RELATIVELY SHORT AS WELL BECAUSE BOTH 00Z NAM/GFS
INDICATE CLDS NOW STREAMING NEWD TOWARD CENTRAL WI AHEAD OF PAIR OF
SLOWLY APRCHG NRN BRANCH DISTURBANCES WL ARRIVE AT THE WI BORDER
LATER THIS MRNG. INCLUDED A MENTION OF FLURRIES OVER THE SCENTRAL
THIS AFTN WITH SOMEWHAT DEEPER MSTR UNDER AREA OF WEAK DEEP LYR
QVECTOR CNVGC. WITH ABUNDANT CLD COVER MORE LIKELY...WL TEND TOWARD
THE LOWER END OF GUIDANCE FOR MAX TEMPS...WHICH IS IN GOOD AGREEMENT
WITH GOING FCST. EXPECT THE HIER MAX TEMPS OVER THE NCENTRAL FM
BARAGA-MQT WHERE LLVL SSW FLOW DOWNSLOPES.
TNGT...AS PAIR OF NRN BRANCH SHRTWVS SHIFT E INTO THE UPR LKS...
GUIDANCE SHOWS THESE DISTURBANCES FADING UNDER LARGER SCALE HGT
RISES ASSOCIATED WITH BLDG UPR RDG ON NRN FLANK OF STRONGER SRN
BRANCH DISTURBANCE MOVING INTO THE MID-MS RIVER VALLEY. ALTHOUGH
LLVL FLOW TENDS ACYC...WINDS ARE FCST TO BE LGT. SO RATHER MOIST
LLVLS WL BE LINGERING IN THE ABSENCE OF SGNFT LLVL DRYING. THE
QUESTION IS WHETHER LARGER SCALE SUBSIDENCE WL RESULT IN THE BREAK
UP OF THIS LO CLD. IN THE ABSENCE OF SGNFT LLVL DRYING AND IN THE
PRESENCE OF DIURNAL COOLING...SUSPECT THE RESULT WL BE LINGERING LO
CLDS THRU THE NGT WITH SUBSIDENCE STRENGTHENING THE INVRN THAT TRAPS
THIS MSTR. CONSIDERING THE UNCERTAINTY...MADE FEW CHGS TO GOING MIN
TEMPS FCST. IF THE LO CLDS ARE MORE PERSISTENT...FCST MIN TEMPS IN
THE UPR TEENS/LO 20S WL HAVE TO BE RAISED.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 337 AM EST MON FEB 25 2013
UPPER MICHIGAN LOOK TO BE TAKING A BREAK FROM THE MODERATE TO HEAVY
SNOW THAT HAS BEEN COMMON PLACE OVER THE PAST WEEK OR SO.
THE CURRENT 500MB LOW SWINGING ACROSS NORTHERN TEXAS THIS MORNING
SHOULD BE OVER NORTHERN ARKANSAS/SOUTHERN MISSOURI BY 12Z
TUESDAY...WITH THE RIDGE EXTENDING FROM THE ATLANTIC BACK THROUGH
UPPER MICHIGAN/LAKE SUPERIOR/NORTHERN MINNESOTA.
THE 500MB RIDGE WILL BE QUICKLY PUSHED NORTH OF THE AREA DURING THE
DAY TUESDAY...WITH THE THEN NEARLY STACKED SFC-500MB SHOULD BE ABLE
TO LIFT TO SOUTHERN ILLINOIS/INDIANA. E-ENE WINDS WILL BE ON THE
INCREASE ACROSS UPPER MICHIGAN...AND IN PARTICULAR ALONG LAKE
MICHIGAN. WITH SURFACE TEMPERATURES IN THE LOW 30S...AND 850MB TEMPS
HOVERING AROUND -3C NO LAKE EFFECT SNOW IS EXPECTED. IN FACT...DRY
WEATHER SHOULD BE THE RULE THROUGH TUESDAY EVENING.
THE 25/00Z NAM IS A STRONGER FAR NORTHERN OUTLIER WITH THE 500MB
LOW...BRINGING THE 500MB LOW OVER CENTRAL LOWER MI BY 18Z WEDNESDAY.
THE CONSENSUS OF THE GFS/ECMWF/CANADIAN HAS THE FEATURE SOUTH OF
DETROIT... NORTHERN OHIO...OR ACROSS NORTHWESTERN PENNSYLVANIA. THE
DIVERGENCE OF THE NAM SOLUTION IS MOST DRAMATIC AFTER 00Z
WEDNESDAY...AND WILL THEREFORE NOT BE UTILIZED IN OUR ONGOING
FORECAST BEYOND THAT POINT. TO A LESSER EXTENT THE CANADIAN BRIDGES
THE GAP BETWEEN THE FASTER GFS/ECMWF AND THE NORTHWESTERLY NAM...BUT
ENDS UP RUNNING APPROXIMATELY 12HRS BEHIND THE ECMWF BY THURSDAY /AT
500MB ACROSS NEW YORK AND THE NEW ENGLAND STATES. MAY NEED TO ADD
FLURRIES FOR UPSLOPE AREAS OF NORTH CENTRAL UPPER MICHIGAN NEAR LAKE
SUPERIOR LATE WEDNESDAY AFTERNOON ON.
EXPECT A SHORTWAVE TO SWING ACROSS ONTARIO WEDNESDAY NIGHT INTO
THURSDAY...BUT HAVE LITTLE INFLUENCE ON OUR WEATHER OTHER THAN
KEEPING CLOUDS OVERHEAD. 850MB TEMPS WILL BE ABLE TO DROP TO AROUND
-8C THURSDAY AS COOLER AIR PUSHES IN BEHIND THE MAIN LOW. WITH N-NNE
WINDS OFF LAKE SUPERIOR THERE WILL BE AN INCREASED CHANCE OF LIGHT
LAKE EFFECT SNOW SHOWERS...WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...DESPITE A STRONG INVERSION NOTED OFF THE GFS HOVERING
NEAR 850MB. THE DGZ LOOKS TO REBOUND...ALTHOUGH THIN /ABOUT 50MB
THICK/ LATE WEDNESDAY NIGHT THROUGH SATURDAY MORNING.
ANOTHER 500MB RIDGE WILL BE ABLE TO PUSH ACROSS THE UPPER GREAT
LAKES THURSDAY THROUGH MUCH OF FRIDAY. EXPECT COOLER AIR TO FILTER
IN AGAIN FRIDAY NIGHT...AND TAKE HOLD OF THE UPPER GREAT LAKES BY
SUNDAY AS 850MB TEMPS FALL FROM AROUND -10C TO -13 OR -14C. WIND
DIRECTION DOES NOT CHANGE MUCH DURING THIS TIME...WITH FAIRLY STEADY
N-NE WINDS SLIDING IN OFF LAKE SUPERIOR. AS A RESULT...IT WILL BE
DIFFICULT TO TAKE OUT THE MENTION OF LIGHT SNOW SHOWERS NEAR LAKE
SUPERIOR /EVEN IF IT IS JUST A SLIGHT CHANCE/...DESPITE THE STRONG
SURFACE HIGH STRETCHING FROM NORTHERN HUDSON BAY THROUGH ONTARIO AND
PORTIONS OF LAKE SUPERIOR THURSDAY NIGHT THROUGH SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1237 PM EST MON FEB 25 2013
VFR CONDITIONS SHOULD PREVAIL THRU THE FCST PERIOD AT KIWD/KCMX...
THOUGH PROXIMITY OF LOWER CIGS JUST TO THE S AND SW MAY RESULT IN
MVFR CIGS DEVELOPING AT KIWD AND PERHAPS AT KCMX THIS AFTN/EVENING.
SHOULD SKIES CLEAR TONIGHT...FOG AND POSSIBLE IFR CONDITIONS COULD
DEVELOP AT KIWD/KCMX. AT KSAW...HIGH MVFR CIGS ARE LIKELY TO PREVAIL
INTO THE EVENING GIVEN UPSTREAM MVFR CIGS. IF CLOUDS SCATTER OUT
LATER TONIGHT...IFR CONDITIONS COULD ALSO DEVELOP AT KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 337 AM EST MON FEB 25 2013
A RIDGE OF HIGH PRESSURE JUST EAST OF LAKE SUPERIOR WILL REMAIN OVER
THE UPPER GREAT LAKES THROUGH TONIGHT. EXPECT LOW PRESSURE OVER THE
SOUTHERN PLAINS TO TRACK NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY
ON TUESDAY...BEFORE STALLING OVER THE LOWER GREAT LAKES ON
WEDNESDAY. A PROLONGED PERIOD OF N TO NE WINDS CAN BE
EXPECTED...WITH WINDS OF 15 TO 30KTS TUESDAY INTO FRIDAY. A FEW GALE
FORCE GUSTS TO 35 KNOTS WILL BE POSSIBLE THURSDAY OVER MAINLY
CENTRAL LAKE SUPERIOR. THE LOW WILL THEN MOVE EAST THURSDAY THROUGH
FRIDAY AS HIGH PRESSURE OF NOSES SOUTHWARD INTO NORTHERN
ONTARIO...WITH LIGHTER WINDS TAKING HOLD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
623 AM EST MON FEB 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM EST MON FEB 25 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW
DOMINATING THE FLOW OVER NAMERICA. RDG IN THE NRN BRANCH IS PRESENT
FM JAMES BAY INTO THE UPR GRT LKS TO THE W OF DEPARTING CLOSED LO IN
SE CANADA/NEW ENGLAND...AND A SFC HI PRES RDG EXTENDS FM NE ONTARIO
THRU ECENTRAL UPR MI INTO THE UPR MIDWEST. WITH DRY AIR AOA H8 AS
SHOWN ON 00Z APX/GRB RAOBS AND LARGER SCALE SUBSIDENCE UNDER THE
RDG...THERE IS NO PCPN IN THE AREA. EVEN LES IS ABSENT WITH LLVL
ACYC FLOW AND H85 TEMPS -6C AT INL AND GRB. DESPITE PASSAGE OF SFC
RDG AXIS...QUITE A BIT OF LO CLD LINGERS WITH SOME MSTR/RELATIVELY
HI SFC DEWPTS TRAPPED BLO SUBSIDENCE INVRN H825-875 SHOWN ON THE 00Z
APX/GRB RAOBS. SOME CLRG HAS OCCURRED OVER THE W AND NEAR THE WI
BORDER INTO NE MN/NRN WI...WHERE SOME LLVL DRY AIR SHOWN ON THE 00Z
GRB/MPX RAOBS HAS SHIFTED TO THE N. WHERE SKIES HAVE CLRD...TEMPS
FELL OFF SHARPLY IN THE PRESENCE OF NEAR CALM WINDS. SOME PATCHY
FOG/ST HAS ALSO DVLPD...SO THE CLRG HOLES ARE IN SOME CASES SHORT
LIVED. ALTHOUGH THERE ARE MORE HOLES IN THE LO CLDS OVER FAR NRN
WI/NE MN...MORE LO/MID CLDS ARE STREAMING NEWD INTO CNTRL MN/WI IN
THE LLVL SW FLOW BTWN RDG AXIS OVER UPR MI AND LO PRES TROF
EXTENDING FM LK WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH PAIR OF
NRN BRANCH DISTURBANCES. A POTENT DISTURBANCE IN THE THE SRN BRANCH
IS PRESENT OVER THE SRN ROCKIES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE TRICKY CLD TRENDS/IMPACT ON
TEMPS.
DESPITE SOME DIURNAL HEATING FM INCRSG SUN ANGLE AND SW FLOW ON THE
BACK SIDE OF HI PRES THAT WL ELIMINATE ANY LK SUP INFLUENCE AND
ADVECT SOME DRIER AIR THAT HAS CAUSED CLRG OVER NW WI...RECENT
TRENDS INDICATE LO CLDS MIGHT PROVE QUITE RESILIENT OVER THE CWA
WITH MORE MORE LO CLDS TENDING TO FORM OVER NRN WI. THE WINDOW FOR
CLRG WL BE RELATIVELY SHORT AS WELL BECAUSE BOTH 00Z NAM/GFS
INDICATE CLDS NOW STREAMING NEWD TOWARD CENTRAL WI AHEAD OF PAIR OF
SLOWLY APRCHG NRN BRANCH DISTURBANCES WL ARRIVE AT THE WI BORDER
LATER THIS MRNG. INCLUDED A MENTION OF FLURRIES OVER THE SCENTRAL
THIS AFTN WITH SOMEWHAT DEEPER MSTR UNDER AREA OF WEAK DEEP LYR
QVECTOR CNVGC. WITH ABUNDANT CLD COVER MORE LIKELY...WL TEND TOWARD
THE LOWER END OF GUIDANCE FOR MAX TEMPS...WHICH IS IN GOOD AGREEMENT
WITH GOING FCST. EXPECT THE HIER MAX TEMPS OVER THE NCENTRAL FM
BARAGA-MQT WHERE LLVL SSW FLOW DOWNSLOPES.
TNGT...AS PAIR OF NRN BRANCH SHRTWVS SHIFT E INTO THE UPR LKS...
GUIDANCE SHOWS THESE DISTURBANCES FADING UNDER LARGER SCALE HGT
RISES ASSOCIATED WITH BLDG UPR RDG ON NRN FLANK OF STRONGER SRN
BRANCH DISTURBANCE MOVING INTO THE MID-MS RIVER VALLEY. ALTHOUGH
LLVL FLOW TENDS ACYC...WINDS ARE FCST TO BE LGT. SO RATHER MOIST
LLVLS WL BE LINGERING IN THE ABSENCE OF SGNFT LLVL DRYING. THE
QUESTION IS WHETHER LARGER SCALE SUBSIDENCE WL RESULT IN THE BREAK
UP OF THIS LO CLD. IN THE ABSENCE OF SGNFT LLVL DRYING AND IN THE
PRESENCE OF DIURNAL COOLING...SUSPECT THE RESULT WL BE LINGERING LO
CLDS THRU THE NGT WITH SUBSIDENCE STRENGTHENING THE INVRN THAT TRAPS
THIS MSTR. CONSIDERING THE UNCERTAINTY...MADE FEW CHGS TO GOING MIN
TEMPS FCST. IF THE LO CLDS ARE MORE PERSISTENT...FCST MIN TEMPS IN
THE UPR TEENS/LO 20S WL HAVE TO BE RAISED.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 337 AM EST MON FEB 25 2013
UPPER MICHIGAN LOOK TO BE TAKING A BREAK FROM THE MODERATE TO HEAVY
SNOW THAT HAS BEEN COMMON PLACE OVER THE PAST WEEK OR SO.
THE CURRENT 500MB LOW SWINGING ACROSS NORTHERN TEXAS THIS MORNING
SHOULD BE OVER NORTHERN ARKANSAS/SOUTHERN MISSOURI BY 12Z
TUESDAY...WITH THE RIDGE EXTENDING FROM THE ATLANTIC BACK THROUGH
UPPER MICHIGAN/LAKE SUPERIOR/NORTHERN MINNESOTA.
THE 500MB RIDGE WILL BE QUICKLY PUSHED NORTH OF THE AREA DURING THE
DAY TUESDAY...WITH THE THEN NEARLY STACKED SFC-500MB SHOULD BE ABLE
TO LIFT TO SOUTHERN ILLINOIS/INDIANA. E-ENE WINDS WILL BE ON THE
INCREASE ACROSS UPPER MICHIGAN...AND IN PARTICULAR ALONG LAKE
MICHIGAN. WITH SURFACE TEMPERATURES IN THE LOW 30S...AND 850MB TEMPS
HOVERING AROUND -3C NO LAKE EFFECT SNOW IS EXPECTED. IN FACT...DRY
WEATHER SHOULD BE THE RULE THROUGH TUESDAY EVENING.
THE 25/00Z NAM IS A STRONGER FAR NORTHERN OUTLIER WITH THE 500MB
LOW...BRINGING THE 500MB LOW OVER CENTRAL LOWER MI BY 18Z WEDNESDAY.
THE CONSENSUS OF THE GFS/ECMWF/CANADIAN HAS THE FEATURE SOUTH OF
DETROIT... NORTHERN OHIO...OR ACROSS NORTHWESTERN PENNSYLVANIA. THE
DIVERGENCE OF THE NAM SOLUTION IS MOST DRAMATIC AFTER 00Z
WEDNESDAY...AND WILL THEREFORE NOT BE UTILIZED IN OUR ONGOING
FORECAST BEYOND THAT POINT. TO A LESSER EXTENT THE CANADIAN BRIDGES
THE GAP BETWEEN THE FASTER GFS/ECMWF AND THE NORTHWESTERLY NAM...BUT
ENDS UP RUNNING APPROXIMATELY 12HRS BEHIND THE ECMWF BY THURSDAY /AT
500MB ACROSS NEW YORK AND THE NEW ENGLAND STATES. MAY NEED TO ADD
FLURRIES FOR UPSLOPE AREAS OF NORTH CENTRAL UPPER MICHIGAN NEAR LAKE
SUPERIOR LATE WEDNESDAY AFTERNOON ON.
EXPECT A SHORTWAVE TO SWING ACROSS ONTARIO WEDNESDAY NIGHT INTO
THURSDAY...BUT HAVE LITTLE INFLUENCE ON OUR WEATHER OTHER THAN
KEEPING CLOUDS OVERHEAD. 850MB TEMPS WILL BE ABLE TO DROP TO AROUND
-8C THURSDAY AS COOLER AIR PUSHES IN BEHIND THE MAIN LOW. WITH N-NNE
WINDS OFF LAKE SUPERIOR THERE WILL BE AN INCREASED CHANCE OF LIGHT
LAKE EFFECT SNOW SHOWERS...WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...DESPITE A STRONG INVERSION NOTED OFF THE GFS HOVERING
NEAR 850MB. THE DGZ LOOKS TO REBOUND...ALTHOUGH THIN /ABOUT 50MB
THICK/ LATE WEDNESDAY NIGHT THROUGH SATURDAY MORNING.
ANOTHER 500MB RIDGE WILL BE ABLE TO PUSH ACROSS THE UPPER GREAT
LAKES THURSDAY THROUGH MUCH OF FRIDAY. EXPECT COOLER AIR TO FILTER
IN AGAIN FRIDAY NIGHT...AND TAKE HOLD OF THE UPPER GREAT LAKES BY
SUNDAY AS 850MB TEMPS FALL FROM AROUND -10C TO -13 OR -14C. WIND
DIRECTION DOES NOT CHANGE MUCH DURING THIS TIME...WITH FAIRLY STEADY
N-NE WINDS SLIDING IN OFF LAKE SUPERIOR. AS A RESULT...IT WILL BE
DIFFICULT TO TAKE OUT THE MENTION OF LIGHT SNOW SHOWERS NEAR LAKE
SUPERIOR /EVEN IF IT IS JUST A SLIGHT CHANCE/...DESPITE THE STRONG
SURFACE HIGH STRETCHING FROM NORTHERN HUDSON BAY THROUGH ONTARIO AND
PORTIONS OF LAKE SUPERIOR THURSDAY NIGHT THROUGH SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 620 AM EST MON FEB 25 2013
EXPECT VFR CONDITIONS TO PREDOMINATE TODAY WITH DAYTIME HEATING AND
ARRIVAL OF LLVL DRY AIR SHOWN ON THE 00Z GRB/MPX RAOBS IN GENERAL SW
FLOW. THE ONLY EXCEPTION MAY BE SOME FOG AT SAW EARLY UNDER SMALL
AREA OF MOCLR SKIES. CIGS MAY DIP INTO THE MVFR RANGE FOR A TIME
TNGT WITH ARRIVAL OF A BIT MORE LLVL MSTR IN THE PRESENCE OF DIURNAL
COOLING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 337 AM EST MON FEB 25 2013
A RIDGE OF HIGH PRESSURE JUST EAST OF LAKE SUPERIOR WILL REMAIN OVER
THE UPPER GREAT LAKES THROUGH TONIGHT. EXPECT LOW PRESSURE OVER THE
SOUTHERN PLAINS TO TRACK NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY
ON TUESDAY...BEFORE STALLING OVER THE LOWER GREAT LAKES ON
WEDNESDAY. A PROLONGED PERIOD OF N TO NE WINDS CAN BE
EXPECTED...WITH WINDS OF 15 TO 30KTS TUESDAY INTO FRIDAY. A FEW GALE
FORCE GUSTS TO 35 KNOTS WILL BE POSSIBLE THURSDAY OVER MAINLY
CENTRAL LAKE SUPERIOR. THE LOW WILL THEN MOVE EAST THURSDAY THROUGH
FRIDAY AS HIGH PRESSURE OF NOSES SOUTHWARD INTO NORTHERN
ONTARIO...WITH LIGHTER WINDS TAKING HOLD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
338 AM EST MON FEB 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM EST MON FEB 25 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW
DOMINATING THE FLOW OVER NAMERICA. RDG IN THE NRN BRANCH IS PRESENT
FM JAMES BAY INTO THE UPR GRT LKS TO THE W OF DEPARTING CLOSED LO IN
SE CANADA/NEW ENGLAND...AND A SFC HI PRES RDG EXTENDS FM NE ONTARIO
THRU ECENTRAL UPR MI INTO THE UPR MIDWEST. WITH DRY AIR AOA H8 AS
SHOWN ON 00Z APX/GRB RAOBS AND LARGER SCALE SUBSIDENCE UNDER THE
RDG...THERE IS NO PCPN IN THE AREA. EVEN LES IS ABSENT WITH LLVL
ACYC FLOW AND H85 TEMPS -6C AT INL AND GRB. DESPITE PASSAGE OF SFC
RDG AXIS...QUITE A BIT OF LO CLD LINGERS WITH SOME MSTR/RELATIVELY
HI SFC DEWPTS TRAPPED BLO SUBSIDENCE INVRN H825-875 SHOWN ON THE 00Z
APX/GRB RAOBS. SOME CLRG HAS OCCURRED OVER THE W AND NEAR THE WI
BORDER INTO NE MN/NRN WI...WHERE SOME LLVL DRY AIR SHOWN ON THE 00Z
GRB/MPX RAOBS HAS SHIFTED TO THE N. WHERE SKIES HAVE CLRD...TEMPS
FELL OFF SHARPLY IN THE PRESENCE OF NEAR CALM WINDS. SOME PATCHY
FOG/ST HAS ALSO DVLPD...SO THE CLRG HOLES ARE IN SOME CASES SHORT
LIVED. ALTHOUGH THERE ARE MORE HOLES IN THE LO CLDS OVER FAR NRN
WI/NE MN...MORE LO/MID CLDS ARE STREAMING NEWD INTO CNTRL MN/WI IN
THE LLVL SW FLOW BTWN RDG AXIS OVER UPR MI AND LO PRES TROF
EXTENDING FM LK WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH PAIR OF
NRN BRANCH DISTURBANCES. A POTENT DISTURBANCE IN THE THE SRN BRANCH
IS PRESENT OVER THE SRN ROCKIES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE TRICKY CLD TRENDS/IMPACT ON
TEMPS.
DESPITE SOME DIURNAL HEATING FM INCRSG SUN ANGLE AND SW FLOW ON THE
BACK SIDE OF HI PRES THAT WL ELIMINATE ANY LK SUP INFLUENCE AND
ADVECT SOME DRIER AIR THAT HAS CAUSED CLRG OVER NW WI...RECENT
TRENDS INDICATE LO CLDS MIGHT PROVE QUITE RESILIENT OVER THE CWA
WITH MORE MORE LO CLDS TENDING TO FORM OVER NRN WI. THE WINDOW FOR
CLRG WL BE RELATIVELY SHORT AS WELL BECAUSE BOTH 00Z NAM/GFS
INDICATE CLDS NOW STREAMING NEWD TOWARD CENTRAL WI AHEAD OF PAIR OF
SLOWLY APRCHG NRN BRANCH DISTURBANCES WL ARRIVE AT THE WI BORDER
LATER THIS MRNG. WITH ABUNDANT CLD COVER MORE LIKELY...WL TEND
TOWARD THE LOWER END OF GUIDANCE FOR MAX TEMPS...WHICH IS IN GOOD
AGREEMENT WITH GOING FCST. EXPECT THE HIER MAX TEMPS OVER THE
NCENTRAL FM BARAGA-MQT WHERE LLVL SSW FLOW DOWNSLOPES.
TNGT...AS PAIR OF NRN BRANCH SHRTWVS SHIFT E INTO THE UPR LKS...
GUIDANCE SHOWS THESE DISTURBANCES FADING UNDER LARGER SCALE HGT
RISES ASSOCIATED WITH BLDG UPR RDG ON NRN FLANK OF STRONGER SRN
BRANCH DISTURBANCE MOVING INTO THE MID-MS RIVER VALLEY. ALTHOUGH
LLVL FLOW TENDS ACYC...WINDS ARE FCST TO BE LGT. SO RATHER MOIST
LLVLS WL BE LINGERING IN THE ABSENCE OF SGNFT LLVL DRYING. THE
QUESTION IS WHETHER LARGER SCALE SUBSIDENCE WL RESULT IN THE BREAK
UP OF THIS LO CLD. IN THE ABSENCE OF SGNFT LLVL DRYING AND IN THE
PRESENCE OF DIURNAL COOLING...SUSPECT THE RESULT WL BE LINGERING LO
CLDS THRU THE NGT WITH SUBSIDENCE STRENGTHENING THE INVRN THAT TRAPS
THIS MSTR. CONSIDERING THE UNCERTAINTY...MADE FEW CHGS TO GOING MIN
TEMPS FCST. IF THE LO CLDS ARE MORE PERSISTENT...FCST MIN TEMPS IN
THE UPR TEENS/LO 20S WL HAVE TO BE RAISED.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 337 AM EST MON FEB 25 2013
UPPER MICHIGAN LOOK TO BE TAKING A BREAK FROM THE MODERATE TO HEAVY
SNOW THAT HAS BEEN COMMON PLACE OVER THE PAST WEEK OR SO.
THE CURRENT 500MB LOW SWINGING ACROSS NORTHERN TEXAS THIS MORNING
SHOULD BE OVER NORTHERN ARKANSAS/SOUTHERN MISSOURI BY 12Z
TUESDAY...WITH THE RIDGE EXTENDING FROM THE ATLANTIC BACK THROUGH
UPPER MICHIGAN/LAKE SUPERIOR/NORTHERN MINNESOTA.
THE 500MB RIDGE WILL BE QUICKLY PUSHED NORTH OF THE AREA DURING THE
DAY TUESDAY...WITH THE THEN NEARLY STACKED SFC-500MB SHOULD BE ABLE
TO LIFT TO SOUTHERN ILLINOIS/INDIANA. E-ENE WINDS WILL BE ON THE
INCREASE ACROSS UPPER MICHIGAN...AND IN PARTICULAR ALONG LAKE
MICHIGAN. WITH SURFACE TEMPERATURES IN THE LOW 30S...AND 850MB TEMPS
HOVERING AROUND -3C NO LAKE EFFECT SNOW IS EXPECTED. IN FACT...DRY
WEATHER SHOULD BE THE RULE THROUGH TUESDAY EVENING.
THE 25/00Z NAM IS A STRONGER FAR NORTHERN OUTLIER WITH THE 500MB
LOW...BRINGING THE 500MB LOW OVER CENTRAL LOWER MI BY 18Z WEDNESDAY.
THE CONSENSUS OF THE GFS/ECMWF/CANADIAN HAS THE FEATURE SOUTH OF
DETROIT... NORTHERN OHIO...OR ACROSS NORTHWESTERN PENNSYLVANIA. THE
DIVERGENCE OF THE NAM SOLUTION IS MOST DRAMATIC AFTER 00Z
WEDNESDAY...AND WILL THEREFORE NOT BE UTILIZED IN OUR ONGOING
FORECAST BEYOND THAT POINT. TO A LESSER EXTENT THE CANADIAN BRIDGES
THE GAP BETWEEN THE FASTER GFS/ECMWF AND THE NORTHWESTERLY NAM...BUT
ENDS UP RUNNING APPROXIMATELY 12HRS BEHIND THE ECMWF BY THURSDAY /AT
500MB ACROSS NEW YORK AND THE NEW ENGLAND STATES. MAY NEED TO ADD
FLURRIES FOR UPSLOPE AREAS OF NORTH CENTRAL UPPER MICHIGAN NEAR LAKE
SUPERIOR LATE WEDNESDAY AFTERNOON ON.
EXPECT A SHORTWAVE TO SWING ACROSS ONTARIO WEDNESDAY NIGHT INTO
THURSDAY...BUT HAVE LITTLE INFLUENCE ON OUR WEATHER OTHER THAN
KEEPING CLOUDS OVERHEAD. 850MB TEMPS WILL BE ABLE TO DROP TO AROUND
-8C THURSDAY AS COOLER AIR PUSHES IN BEHIND THE MAIN LOW. WITH N-NNE
WINDS OFF LAKE SUPERIOR THERE WILL BE AN INCREASED CHANCE OF LIGHT
LAKE EFFECT SNOW SHOWERS...WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...DESPITE A STRONG INVERSION NOTED OFF THE GFS HOVERING
NEAR 850MB. THE DGZ LOOKS TO REBOUND...ALTHOUGH THIN /ABOUT 50MB
THICK/ LATE WEDNESDAY NIGHT THROUGH SATURDAY MORNING.
ANOTHER 500MB RIDGE WILL BE ABLE TO PUSH ACROSS THE UPPER GREAT
LAKES THURSDAY THROUGH MUCH OF FRIDAY. EXPECT COOLER AIR TO FILTER
IN AGAIN FRIDAY NIGHT...AND TAKE HOLD OF THE UPPER GREAT LAKES BY
SUNDAY AS 850MB TEMPS FALL FROM AROUND -10C TO -13 OR -14C. WIND
DIRECTION DOES NOT CHANGE MUCH DURING THIS TIME...WITH FAIRLY STEADY
N-NE WINDS SLIDING IN OFF LAKE SUPERIOR. AS A RESULT...IT WILL BE
DIFFICULT TO TAKE OUT THE MENTION OF LIGHT SNOW SHOWERS NEAR LAKE
SUPERIOR /EVEN IF IT IS JUST A SLIGHT CHANCE/...DESPITE THE STRONG
SURFACE HIGH STRETCHING FROM NORTHERN HUDSON BAY THROUGH ONTARIO AND
PORTIONS OF LAKE SUPERIOR THURSDAY NIGHT THROUGH SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1231 AM EST MON FEB 25 2013
GIVEN FAIRLY LOW DEWPOINT DEPRESSIONS AND THE OBSERVANCE OF PATCHY
FOG FORMING OVER NRN WI...HAVE DECIDED TO INCLUDE A MENTION OF MVFR
OR EVEN IFR VSBYS IN FOG AT ALL TAF SITES LATER TONIGHT WITH MVFR
CIGS. ANY FOG SHOULD LIFT BY LATE MON MORNING AND EXPECT MVFR CLOUDS
TO LIFT BY AFTERNOON WITH ADVECTION OF DRIER AIR AT LOW-LVLS IN SW
FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 337 AM EST MON FEB 25 2013
A RIDGE OF HIGH PRESSURE JUST EAST OF LAKE SUPERIOR WILL REMAIN OVER
THE UPPER GREAT LAKES THROUGH TONIGHT. EXPECT LOW PRESSURE OVER THE
SOUTHERN PLAINS TO TRACK NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY
ON TUESDAY...BEFORE STALLING OVER THE LOWER GREAT LAKES ON
WEDNESDAY. A PROLONGED PERIOD OF N TO NE WINDS CAN BE
EXPECTED...WITH WINDS OF 15 TO 30KTS TUESDAY INTO FRIDAY. A FEW GALE
FORCE GUSTS TO 35 KNOTS WILL BE POSSIBLE THURSDAY OVER MAINLY
CENTRAL LAKE SUPERIOR. THE LOW WILL THEN MOVE EAST THURSDAY THROUGH
FRIDAY AS HIGH PRESSURE OF NOSES SOUTHWARD INTO NORTHERN
ONTARIO...WITH LIGHTER WINDS TAKING HOLD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS/KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
303 PM CST MON FEB 25 2013
.DISCUSSION...
A RATHER BENIGN FORECAST PERIOD IS AHEAD FOR THE LOCAL AREA...AS EYES
ARE FOCUSED TO THE SOUTH WITH THE POTENT WINTER STORM UNDERWAY.
FOR THE MPX CWA...THE PRIMARY CONCERNS THIS FORECAST PERIOD ARE
FOG TONIGHT AND SNOWFALL CHANCES FOR TOMORROW NIGHT INTO WEDNESDAY.
FOG AND LOW CLOUDS HAVE BEEN VERY SLOW TO ERODE TODAY...WITH THE
LIGHT WINDS AND LOITERING HIGH PRESSURE RIDGE FIRMLY IN PLACE.
HAVE FINALLY MADE SOME HEADWAY IN THE CLEARING THIS
AFTERNOON...BUT THINK FOG REDEVELOPMENT IS QUITE POSSIBLE AGAIN
TONIGHT...ESPECIALLY FROM CENTRAL INTO WEST CENTRAL MN WHERE
TEMP/DEWPOINT SPREADS ARE LOW AND WINDS WILL REMAIN LIGHT THROUGH
THE NIGHT. HAVE HIGHLIGHTED THE POTENTIAL FOR PATCHY DENSE FOG IN
THE HWO AND GRIDS...AND WILL MONITOR FOR THE POTENTIAL NEED FOR AN
ADVISORY THIS EVENING AS THE CLEARING EVOLVES.
ON TUESDAY...NORTHEAST WINDS INCREASE AS THE AFOREMENTIONED LOW
PRESSURE SYSTEM LIFTS ACROSS THE OH VALLEY. ON TUESDAY NIGHT INTO
WEDNESDAY...WEAK MID LEVEL ENERGY ON THE NORTHERN/WESTERN
PERIPHERY PIVOTS ACROSS CENTRAL WI AND SERN MN. WHILE THE LIFT AND
MOISTURE ARE MODEST...COULD BE SUFFICIENT TO SQUEEZE OUT A FEW
TENTHS OF AN INCH OF SNOW FROM NEAR ALBERT LEA TOWARD EAU
CLAIRE...WHERE SLIGHT CHANCE POPS HAVE BEEN INCLUDED FOR TUESDAY
NIGHT AND WEDNESDAY.
AFTER THAT...CHANCES FOR MEASURABLE SNOW REALLY DO NOT ARRIVE
UNTIL EARLY NEXT WEEK...AS A CLIPPER SYSTEM DIVES SOUTHEAST FROM
CANADA. THERE/S STILL A LARGE AMOUNT OF UNCERTAINTY WITH THE ROUTE
THIS TROUGH WILL TAKE...BUT WESTERN INTO SOUTH CENTRAL MN APPEARS
TO BE THE MORE FAVORED ROUTE FOR LIGHT SNOWFALL ON MONDAY INTO
TUESDAY.
TEMPERATURES WILL VARY LITTLE THROUGH THE FORECAST PERIOD...WITH
HIGHS GENERALLY FROM 25 TO 35...AND LOWS FROM 10 TO 25.
&&
.AVIATION.../18Z TAF ISSUANCE/
VERY COMPLICATED AVIATION FORECAST AS WINDS REMAIN NEARLY CALM UP
TO 500 METERS WHICH WILL LIMIT ANY MIXING. THE ONLY HELP THIS AFTN
IS THE HIGHER SUN ANGLE ALLOWING FOR BETTER ISOLATION WHICH WILL
LEAD TO SOME EROSION IN THE CLOUDS FROM TOP TO BOTTOM. REGIONAL
SATELLITE INDICATED THE BACK EDGE OF THE LOW CIGS ALONG THE ND/SD
BORDER WITH LITTLE MOVEMENT EASTWARD OVER THE PAST FEW HRS. BASED
ON THE LATEST RAP MIX LAYER UP TO 500 METERS...WINDS ARE NEARLY
CALM AS EXPLAINED BEFORE WITH A MORE SW ORIENTATION NORTH/NE OF
THE FA. A MORE N/NE FLOW ACROSS SW MN WHICH IS HAVING SOME AFFECTS
FROM THE STORM SYSTEM ACROSS THE SOUTH. THE MAIN DILEMMA IS
WHETHER TO SCATTER OUT THE CLOUD COVER THIS AFTN...AND TO LOWER
CIGS/VSBYS ONCE AGAIN OVERNIGHT IN THE TYPICAL AREAS IN THE MN
RIVER VALLEY TO AXN. ONE ITEM THAT DOES PLAY INTO THE FORECAST AFT
12Z TUE...IS THE INCREASING PRESSURE GRADIENT FROM THE STORM SYSTEM
TO THE SOUTH. EVENTUALLY THE PRESSURE GRADIENT WILL PRODUCE A MORE
EAST/NE FLOW TUE...AND ESPECIALLY TUE AFTN/EVENING. THIS WILL
ALLOW FOR MORE MIXING AND THE BETTER CHC OF VFR CONDS TO DEVELOP
AFT THIS TAF PERIOD. WILL CONTINUE PERSISTENCE WITH SOME VFR CONDS
DEVELOPING THIS AFTN AT AXN/RWF/STC. THIS COULD BE VERY SHORT
LIVED...OR EVEN NON-EXISTENT IF THE SUN ISOLATION IS NOT A FACTOR.
KMSP...
WILL CONTINUE THE MVFR CIGS THIS AFTN...WITH A POSSIBLE BREAK TO
VFR BY 00Z. CONFIDENCE IS LOW AS MIXING IN THE BOUNDARY LAYER IS
WEAK. EVENTUALLY WINDS WILL BECOME MORE E/NE LATE TONIGHT/TUESDAY
WHICH SHOULD BEGIN TO ERODE THE STAGNANT AIR MASS THAT HAS BEEN IN
PLACE OVER THE REGION. THE LATEST RAP/HOPWRF REMAINS VERY
PESSIMISTIC FOR THE MVFR CIGS TO CONTINUE WITH VSBYS ALSO
LOWERING OVERNIGHT. WILL CONTINUE THE SAME TREND WITH A PERIOD OF
VFR THIS EVENING...THEN BECOMING MVFR ONCE AGAIN AFT 6Z...WITH THE
POSSIBILITY OF VFR CONDS DEVELOPING AFT 18Z TUE. WINDS WILL BE
LIGHT AND VARIABLE THRU 6Z...WITH A MORE E/NE FLOW DEVELOPING
OVERNIGHT...AND BECOMING STRONGER FROM THE NE TUESDAY AFTN.
/OUTLOOK FOR KMSP/
WED...MVFR IN THE MORNING...THEN VFR. WINDS NNW 15KTS.
THU/FRI...VFR WITH MVFR CIGS POSSIBLE. WINDS N/NNE 5 TO 10KTS.
..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
LS/JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1126 AM CST MON FEB 25 2013
.DISCUSSION...
OVERVIEW...SNOWSTORM STILL ON TRACK FOR THE CENTRAL/SOUTHERN
PLAINS AND THE GREAT LAKES REGION OVER THE NEXT 48 HOURS. WE
REMAIN ON THE NORTHERN FRINGE FOR EVEN LIGHT SNOW AT THIS POINT.
BEST CHANCE FOR ANY SNOW REMAINS ACROSS PORTIONS OF WEST CENTRAL
WISCONSIN AND SOUTHEAST MINNESOTA TUESDAY NIGHT AND WEDNESDAY.
TEMPS WILL REMAIN NEAR CLIMATE NORMALS FOR THE NEXT SEVERAL DAYS.
WEAK 850-700MB WARM ADVECTION AND EVEN A SMALL AMOUNT OF FGEN IN
ROUGHLY THE SAME LAYER CONTRIBUTING TO THE LIGHT SNOW CURRENTLY
STRETCHING FROM EASTERN NE TO SOUTHWEST MN. MOST OF THIS IS
FALLING OUTSIDE OF THE FORECAST AREA...AND THERE IS EVEN LESS A
CHANCE FOR LIGHT SNOW AFTER 12Z. INCLUDED SCATTERED FLURRIES IN
WEST CENTRAL WI...BUT KEPT THE CHANCE FOR MEASURABLE UNDER 15%.
TEMPS THIS MORNING ARE BEING HELD IN CHECK DUE TO THE STEADY
STREAM OF MID AND HIGH CLOUDS FROM THE LOW CURRENTLY IN WESTERN
TEXAS...AND LOW CLOUDS THAT WERE ADVECTED INTO MN SUNDAY AFTERNOON
AND HAVE LINGERED SINCE. THE QUESTION IS IF AND OR WHEN DO WE
CLEAR OUT TODAY. INCLUDED FOG IN THE GRID IN WESTERN/NORTHERN
PORTIONS OF THE FORECAST AREA WHERE WE THINK THERE IS A BETTER
CHANCE OF BEING CLEAR TONIGHT. DEVELOPING INVERSION TONIGHT ALONG
HYDROLAPSE IN THE LOWEST 500 FT SUGGEST AREAS OF FOG ARE POSSIBLE.
THERE ARE A COUPLE SITES THIS MORNING REPORTING DENSE FOG AND WITH
A LITTLE MORE MELTING EXPECTED TODAY...FOG WILL REMAIN A PROBLEM
IF WE CLEAR OUT TONIGHT. THE GRADIENT REMAINS LIGHT OVER THE NEXT
18-24 HOURS...HOWEVER...AS THE SURFACE LOW LIFTS INTO SOUTHERN MO
LIGHT NORTHEAST WINDS ARE POSSIBLE BY 12Z TUESDAY ACROSS THE
SOUTHERN HALF OF THE CWA. NOT SURE THIS WILL BE ENOUGH TO
PROHIBIT FOG FORMATION.
IT`S FAIRLY CLEAR AFTER VIEWING THE GFS/NAM/ECMWF OVER THE PAST
FEW RUNS THAT THERE ISN`T MUCH CONCERN FOR SNOW IN THE FORECAST
AREA TUESDAY NIGHT AND WEDNESDAY. THE TREND HAS BEEN NEAR STEADY
TO A SLIGHT EASTWARD SHIFT WITH TIME. THE WEAK MID LEVEL
FRONTOGENESIS THAT HANGS BACK WELL WEST OF THE SURFACE LOW ISN`T
AS STRONG AS IT HAS LOOKED IN A COUPLE RUNS THIS PAST WEEKEND.
THE MAIN 500 MB LIFTS OUT OF THE PLAINS OVER THE NEXT 24
HOURS...BUT ANY HOPE FOR LIGHT SNOW HERE SEEMS TO REST WITH THE
SHORT WAVE NOW MOVING INLAND INTO WASHINGTON STATE AND BRITISH
COLUMBIA.
IN TERMS OF TEMPERATURES...REALLY STARTING TO SEE THE EFFECTS OF THE
ALBEDO DIFFERENCES ACROSS THE FORECAST AREA...WITH THE SNOW
COVERED PLAINS AND THE WOODED AREAS IN CENTRAL MN AND WI. EVEN THE
METRO AREAS ARE SHOWING UP AS MORE PRONOUNCED WARM SPOTS WITH THE
PROGRESSIVELY STRONGER LATE FEBRUARY SUNSHINE. THIS IS WHERE OUR
BIAS CORRECTED DATABASE TYPICALLY STARTS DOMINATING THE
VERIFICATION...BUT WE`LL HAVE TO WAIT FOR A MOSTLY SUNNY STRETCH
TO SEE THE FULL BENEFIT OF BIAS CORRECTED GRIDS AND WE MIGHT BE
FAIRLY CLOUDS THROUGH MID WEEK. HAVE TO ADMIT...NOT TERRIBLY
CONFIDENT WITH THE CURRENT SKY AND TEMP FORECAST IN THE COMING
DAYS. THERE IS SOME BUST POTENTIAL WITH THE HIGHS AND LOWS IN THE
COMING DAYS...FOR SUNNY DAYS IN OUR LOW ALBEDO AREAS AND CLEAR
NIGHTS WITH THE EXTENT OF OUR SNOW COVER.
&&
.AVIATION.../18Z TAF ISSUANCE/
VERY COMPLICATED AVIATION FORECAST AS WINDS REMAIN NEARLY CALM UP
TO 500 METERS WHICH WILL LIMIT ANY MIXING. THE ONLY HELP THIS AFTN
IS THE HIGHER SUN ANGLE ALLOWING FOR BETTER ISOLATION WHICH WILL
LEAD TO SOME EROSION IN THE CLOUDS FROM TOP TO BOTTOM. REGIONAL
SATELLITE INDICATED THE BACK EDGE OF THE LOW CIGS ALONG THE ND/SD
BORDER WITH LITTLE MOVEMENT EASTWARD OVER THE PAST FEW HRS. BASED
ON THE LATEST RAP MIX LAYER UP TO 500 METERS...WINDS ARE NEARLY
CALM AS EXPLAINED BEFORE WITH A MORE SW ORIENTATION NORTH/NE OF
THE FA. A MORE N/NE FLOW ACROSS SW MN WHICH IS HAVING SOME AFFECTS
FROM THE STORM SYSTEM ACROSS THE SOUTH. THE MAIN DILEMMA IS
WHETHER TO SCATTER OUT THE CLOUD COVER THIS AFTN...AND TO LOWER
CIGS/VSBYS ONCE AGAIN OVERNIGHT IN THE TYPICAL AREAS IN THE MN
RIVER VALLEY TO AXN. ONE ITEM THAT DOES PLAY INTO THE FORECAST AFT
12Z TUE...IS THE INCREASING PRESSURE GRADIENT FROM THE STORM SYSTEM
TO THE SOUTH. EVENTUALLY THE PRESSURE GRADIENT WILL PRODUCE A MORE
EAST/NE FLOW TUE...AND ESPECIALLY TUE AFTN/EVENING. THIS WILL
ALLOW FOR MORE MIXING AND THE BETTER CHC OF VFR CONDS TO DEVELOP
AFT THIS TAF PERIOD. WILL CONTINUE PERSISTENCE WITH SOME VFR CONDS
DEVELOPING THIS AFTN AT AXN/RWF/STC. THIS COULD BE VERY SHORT
LIVED...OR EVEN NON-EXISTENT IF THE SUN ISOLATION IS NOT A FACTOR.
KMSP...
WILL CONTINUE THE MVFR CIGS THIS AFTN...WITH A POSSIBLE BREAK TO
VFR BY 00Z. CONFIDENCE IS LOW AS MIXING IN THE BOUNDARY LAYER IS
WEAK. EVENTUALLY WINDS WILL BECOME MORE E/NE LATE TONIGHT/TUESDAY
WHICH SHOULD BEGIN TO ERODE THE STAGNANT AIR MASS THAT HAS BEEN IN
PLACE OVER THE REGION. THE LATEST RAP/HOPWRF REMAINS VERY
PESSIMISTIC FOR THE MVFR CIGS TO CONTINUE WITH VSBYS ALSO
LOWERING OVERNIGHT. WILL CONTINUE THE SAME TREND WITH A PERIOD OF
VFR THIS EVENING...THEN BECOMING MVFR ONCE AGAIN AFT 6Z...WITH THE
POSSIBILITY OF VFR CONDS DEVELOPING AFT 18Z TUE. WINDS WILL BE
LIGHT AND VARIABLE THRU 6Z...WITH A MORE E/NE FLOW DEVELOPING
OVERNIGHT...AND BECOMING STRONGER FROM THE NE TUESDAY AFTN.
/OUTLOOK FOR KMSP/
WED...MVFR IN THE MORNING...THEN VFR. WINDS NNW 15KTS.
THU/FRI...VFR WITH MVFR CIGS POSSIBLE. WINDS N/NNE 5 TO 10KTS.
..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CF/JLT
AREA FORECAST DISCUSSION
NWS GLASGOW MT
858 PM MST TUE FEB 26 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH THURSDAY...
MINOR TWEAKS TO SHORT TERM FORECAST FOR THIS UPDATE.
CURRENTLY...A SMALL MID-LEVEL WAVE IS MOVING EASTWARD FROM MONTANA
INTO NORTH DAKOTA. SOME VERY MILD DYNAMICAL LIFT WITH THIS WAVE
HAS GENERATED SOME SHOWERS IN SOUTHEAST SASKATCHEWAN ALONG WITH A
FEW SUB-TRACE SHOWERS IN NORTHEAST MONTANA. HRRR MODEL IS NOT
OPTIMISTIC ABOUT ANYTHING MORE THAN A TRACE WITH THIS WAVE
OVERNIGHT...SO HAVE LIGHT...BUT NOT NONEXISTENT...PPT IN THE
FORECAST FOR THE NORTHEAST CORNER OF THE CWA OVERNIGHT. OUTSIDE OF
THIS VERY LIMITED POSSIBILITY OF SHOWERS TONIGHT...SHORT TERM
FORECAST THROUGH THURSDAY HAS LITTLE CHANCE FOR ANY PPT DUE TO
WEAK AND ILL-DEFINED DYNAMICAL FEATURES.
CLOUDS LOOK LIKE THEY WILL CLEAR FROM WEST TO EAST OVERNIGHT...SO
SHADED TEMPERATURES LOWER IN THE WESTERN HALF OF THE CWA WHERE
CLEARING SKIES SEEMS LIKELY TO ALLOW TEMPERATURES TO FALL IN THE
EARLY MORNING HOURS.
WEDNESDAY STILL LOOKS SLIGHTLY COOLER THAN TUESDAY...THOUGH LESS
WINDY...WITH A WARMING TREND BEGINNING ON THURSDAY. MARTIN
PREVIOUS DISCUSSION...
A WEAK UPPER LEVEL TROUGH WILL DOMINATE THE WEATHER OF NORTHEAST
MONTANA THROUGH THE SHORT TERM. GUSTY NORTHWEST WINDS WILL TAPER
OFF THIS EVENING AS COLD AIR ADVECTION ENDS. SPLITTING ENERGY
UNDER THE TROUGH WILL KEEP CONDITIONS MAINLY DRY ACROSS THE AREA
TONIGHT. THE EXCEPTION TO THIS WILL BE THE NORTHEAST AND EAST
WHICH COULD SEE SOME LIGHT SNOW SHOWERS AS THE NORTHERN BRANCH OF
THE SPLITTING WAVE PUSHES THROUGH.
WEDNESDAY THE WEATHER WILL BE QUIET IN BETWEEN SHORTWAVE FEATURES
AND SKIES WILL AT LEAST PARTIALLY CLEAR. WEDNESDAY NIGHT A
SECOND SHORTWAVE FEATURE WILL PUSH IN FROM THE WEST-NORTHWEST.
MOISTURE IS LACKING WITH THIS FEATURE BUT IT COULD BRING SOME
ISOLATED SHOWERS TO THE SOUTHWEST AS IT PUSHES IN. WEDNESDAY THE
DISTURBANCE WILL EXIT THE REGION AS A NORTHWEST FLOW ALOFT BUILDS
IN ON THE BACK SIDE OF THE UPPER TROUGH. AGAIN CONDITIONS WILL
REMAIN MAINLY DRY...BUT AN ISOLATED SHOWER COULD POP UP AS THE
ATMOSPHERE DESTABILIZES...THUS KEPT THE ISOLATED POPS IN THE
SOUTHEAST. GILCHRIST
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE EXTENDED FORECAST REMAINS IN DECENT SHAPE. 12Z MODELS CONTINUE
TO SHOW AN UPPER RIDGE BUILDING INTO NORTHEAST MONTANA DRIVING IN
RISING 500MB HEIGHTS ALONG WITH WARMING 850MB TEMPERATURES
BEGINNING ON THURSDAY NIGHT. THUS...CONTINUED THE TREND OF WARMING
TEMPERATURES HEADING INTO SATURDAY. IN FACT...THE 12Z ECMWF HAS
850MB TEMPERATURES AS WARM AS +10C BY SATURDAY EVENING. IT IS NOT
OUT OF THE REALM OF POSSIBILITY THAT SOME OF THE SOUTHWESTERN
ZONES REACH HIGHS IN THE UPPER 50S. GIVEN THE RIDGE PARKED ACROSS
THE AREA AND LARGE SCALE SUBSIDENCE...DECIDED TO ALSO KEEP THE CWA
DRY.
SUNDAY NIGHT AND BEYOND...THE POTENTIAL EXISTS FOR A SIGNIFICANT
WINTER STORM TO AFFECT MONTANA LATE THIS WEEKEND INTO THE EARLY
PORTIONS OF NEXT WEEK. THE 12Z ECMWF AND GFS HAVE COME INTO MUCH
BETTER AGREEMENT ON TIMING SINCE PREVIOUS RUNS AND IT APPEARS NOW
THAT THE BEST CHANCES OF PRECIPITATION WILL OCCUR FROM LATE SUNDAY
EVENING LASTING PERHAPS AS LONG AS MONDAY NIGHT AS AN UPPER LEVEL
SHORTWAVE TROUGH DIVES THROUGH THE NORTHWESTERN U.S. AND THEN INTO
THE CENTRAL PLAINS. AN ASSOCIATED AREA OF SURFACE LOW PRESSURE
WILL PASS SOUTH OF THE FORECAST AREA SUNDAY NIGHT AND SLIDE
SOUTHEAST OF THE REGION MONDAY INTO MONDAY NIGHT. AS THIS
HAPPENS...MOISTURE WILL WRAP AROUND THIS LOW PRESSURE SYSTEM AND
INTO NORTHEAST MONTANA. THERMAL PROFILES ARE MARGINAL SUNDAY NIGHT AND
SO THE ONSET PRECIPITATION MAY BEGIN IN THE FORM OF RAIN...BUT
AS THE PRECIPITATION BECOMES STEADIER...DIABATIC COOLING WILL TAKE
PLACE WHICH WILL ACT TO COOL THE VERTICAL PROFILES. COLD AIR WILL
ALSO ADVECT INTO THE REGION BEHIND A COLD FRONTAL PASSAGE
ASSOCIATED WITH THE SURFACE LOW. THIS WILL ALLOW ANY RAIN TO
GRADUALLY TRANSITION TO ALL SNOW. AT THIS TIME IS WHEN THE BEST
CHANCES FOR SNOWFALL ACCUMULATIONS WILL OCCUR ACROSS THE FORECAST
REGION.
HAVING SAID ALL THAT...FINAL SNOW AMOUNTS WILL GREATLY DEPEND UPON THE
EXACT TRACK OF THE LOW PRESSURE SYSTEM AS WELL AS HOW MUCH OF THE
PRECIPITATION FALLS AS RAIN. VERTICAL PROFILES DO SHOW PLENTY OF
MOISTURE IN THE LOW AND MID LEVELS AND SO THE POTENTIAL EXISTS
FOR SIGNIFICANT SNOWFALL ACCUMULATIONS TO OCCUR. HOWEVER...MANY OF
THESE DETAILS DISCUSSED HERE ARE DIFFICULT TO DECIPHER THIS FAR
OUT IN THE FORECAST PERIOD. GIVEN INCREASED SUPPORT FROM GUIDANCE
ON THIS SYSTEM THOUGH...HAVE CERTAINLY INCREASED POPS ACROSS MUCH
OF THE CWA SUNDAY INTO MONDAY NIGHT AND DROPPED TEMPERATURES.
GUSTY WINDS ARE ALSO POSSIBLE ON THE BACKSIDE OF THIS LOW PRESSURE
SYSTEM AS IT PULLS AWAY FROM THE FORECAST AREA. MALIAWCO
PREVIOUS LONG TERM DISCUSSION...
LENGTHENING DAYS AND A HIGHER SUN ARE BEGINNING TO SHOW AS THE
WARMING CONTINUES. AN UPPER RIDGE BUILDING UP OVER THE WESTERN
STATES WILL PUSH THE STATIONARY BOUNDARY EAST. THIS BOUNDARY WILL
ACT AS A WARM FRONT THURSDAY NIGHT AND FRIDAY. EXPECT SOME
ASSOCIATED CLOUDINESS WITH THE FRONT AND A LEE SIDE SURFACE TROUGH
THROUGH FRIDAY NIGHT. 850MB TEMPERATURES WILL RAMP UP FROM AROUND
-4C AT 00Z FRIDAY TO +4C AT 12Z SATURDAY. DURING THE SAME TIME
FRAME 1000MB-500MB THICKNESS HEIGHTS INCREASE FROM 528DM TO 546DM.
THEREFORE BEGINNING FRIDAY LOOK FOR ANOTHER SIGNIFICANT WARMING.
GUIDANCE SUGGESTS TMAX ON SATURDAY REACHING THE UPPER 50S IN THE
SW TO AROUND 40 IN THE NE AS THE RIDGE AXIS PEAKS OVER EASTERN
MONTANA. WITH THE RAPIDLY DIMINISHING SNOW PACK THE HIGHS COULD
TREND HIGHER. THESE MILD TEMPERATURE WILL LAST INTO SUNDAY.
SUNDAY NIGHT AND BEYOND...A CLOSED PACIFIC LOW...CURRENTLY OUT
NEAR THE WESTERN END OF THE ALEUTIANS ISLANDS...WILL BEGIN TO
KNOCK DOWN THE RIDGE ON SUNDAY AS IT MOVES INTO THE NORTHERN
ROCKIES. THIS STORM HAS MUCH MORE ENERGY THAN RECENT STORMS. THE
UPPER LOW REMAINS CLOSED WHILE THE DEVELOPING LEE SURFACE TROUGH
SHOWS SIGNS OF ALSO CLOSING OFF. THIS STORM SHOULD BRING MUCH MORE
MOISTURE WITH IT...WHICH MIGHT FINALLY BRING IN SOME LOCAL
PRECIPITATION. THE GFS IS QUICKER WITH THIS WAVE THAN THE EC...SO
EXPECT THAT THE TIMING AND LOCATION HAVE NOT SETTLED IN
YET...ALTHOUGH LATE IN THE SHIFT THE 00Z EC CAME IN MORE IN SYNC
WITH THE 00Z GFS. THE TROUGH WILL SEND A DISTINCT COLD FRONT OVER
THE REGION. WITH INITIALLY WARM TEMPERATURES...PRECIPITATION
COULD BEGIN AS RAIN... THEN TURNING TO SNOW. BEYOND SUNDAY NIGHT
LOCATION BECOME MUCH LESS CLEAR...BUT MODELS SUGGEST THE LOWS
BEGIN TO STACK UP...WHICH COULD KEEP PRECIPITATION GOING WITH THE
MOISTURE WRAPPING AROUND THE BACKSIDE OF THE STORM. THIS SYSTEM
WILL LIKELY PRODUCE A SIGNIFICANT AMOUNT OF SNOW...BUT IT IS TOO
EARLY TO TELL IF IT WILL BE IN SOUTHERN CANADA OR MONTANA. SCT
&&
.AVIATION...
MVFR CEILINGS THROUGH THIS EVENING. FUEL LOADING MAY BE NEEDED.
CEILINGS WILL SHALLOW AND CLEAR DURING THE MID TO LATE MORNING
WITH VFR BY THE AFTERNOON HOURS.
WINDS WILL BE OUT OF THE NORTHWEST AROUND 5 TO 15 KTS OVERNIGHT
SWITCHING TO THE EAST AND SOUTHEAST AROUND NOON. GAH
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
314 PM EST MON FEB 25 2013
.SYNOPSIS...
LAKE EFFECT CLOUDS AND SCATTERED FLURRIES THIS MORNING...MAINLY IN
CENTRAL NEW YORK...WILL YIELD TO BUILDING HIGH PRESSURE THIS
AFTERNOON. THIS WILL HELP BREAK UP THE CLOUDS LATER TODAY...AND
KEEP THINGS DRY AND QUIET TONIGHT THROUGH MOST OF TUESDAY.
HOWEVER...A MIX OF WINTRY PRECIPITATION IS LIKELY LATE TUESDAY
THROUGH EARLY WEDNESDAY AS LOW PRESSURE MOVES TOWARDS THE REGION
FROM THE OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
1030 AM UPDATE... VSBL SAT ANIMATION INDICATES THAT CLDS ARE
HANGING TOUGH LATE THIS MRNG ACRS CNY/PTNS OF NE PA. THE LATEST
HI-RES NWP GUIDANCE STILL INDICATES THAT SOME DRYING WILL TAKE
PLACE DURG THE COURSE OF THE AFTN...SPCLY FROM THE TWIN TIERS SWD.
WE BLENDED IN THE LATEST RUC13 DATA...WHICH SEEMS TO HAVE A GOOD
HANDLE ON THE CURRENT EVOLUTION. ANY LINGERING FLRYS SHOULD BE
GONE BY 18-19Z.
BASED ON THE 12Z RAOBS AND WEAK ANTICIPATED THERMAL ADVECTION THIS
AFTN...OUR PRESENT HIGH TEMP FCST LOOKS GOOD...AND WAS ONLY
TWEAKED VERY SLIGHTLY.
PREV DISC... 630 AM UPDATE... GRIDS TWEAKED AS PER CURRENT
OBS...AND TO LINGER CLOUD COVER A BIT LONGER INTO THE AFTERNOON.
FORECAST GENERALLY ON TRACK...WITH ONLY SCATTERED FLURRIES
REMAINING DOWNWIND OF LAKE ONTARIO.
EARLIER DISCUSSION... ATMOSPHERIC COLUMN AS A WHOLE IS DRYING OUT...YET
MOISTURE REMAINS TRAPPED IN THE LOWEST FEW THOUSAND FEET AGL UNDER
A WEAK INVERSION. 850MB TEMPERATURES ARE ABOUT 9 OR 10 BELOW ZERO
CELSIUS...BARELY ENOUGH FOR THE WEAK LAKE RESPONSE OF SCATTERED
SNOW SHOWERS CURRENTLY DOWNWIND OF LAKE ONTARIO. WARM AIR
ADVECTION ALOFT WILL GRADUALLY RAISE 850MB TEMPERATURES HEADING
INTO THE DAY WHICH WILL ALLOW SNOW SHOWERS TO TAPER OFF TO A FEW
FLURRIES BEFORE ENDING. HOWEVER...STRATOCUMULUS WILL BE A BIT MORE
STUBBORN...ESPECIALLY CENTRAL NY. OVERALL...SUNSHINE WILL INCREASE
THROUGH THE DAY BUT WILL TAKE LONGER IN SOME PLACES THAN
OTHERS...AND HIGHS WILL BE RIGHT AROUND CLIMATOLOGICAL AVERAGES.
HIGH PRESSURE IN CHARGE TONIGHT FOR QUIET AND MOSTLY CLEAR
CONDITIONS. THE GOOD RADIATIONAL COOLING SET UP WILL YIELD MAINLY
LOWER 20S FOR LOWS...THOUGH SOME TEENS FOR THE MORE TYPICALLY
PRONE COLD AIR DRAINAGE VALLEYS. IN MANY CASES...AT OR SLIGHTLY
BELOW COLDEST MODEL GUIDANCE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
500 AM UPDATE...
TUESDAY....FAIRLY GOOD AGREEMENT AMONGST THE MODELS WITH REGARDS
TO SYNOPTIC FEATURES WITH A DOMINANT SURFACE LOW AROUND 995 MB
TRACKING THROUGH CENTRAL INDIANA WITH A NEW LOW FORMING OVER NORTH
CENTRAL NC BY 0Z WEDNESDAY. THIS IS THE EASIEST PART OF THE
FORECAST WITH THICKENING CLOUDS AND PRECIP HOLDING OFF UNTIL LATE
IN THE DAY. LOOKING FOR ARRIVAL OF PRECIP TOWARD 23Z FAR SOUTH AND
WEST. MODEL PROFILES SHOW WARM SURFACE TEMPS SO INITIAL SHOT OF
PRECIP COULD BE IN THE FORM OF SNOW...SLEET OR PLAIN RAIN.
TUESDAY NIGHT...UNCERTAINTY IS THE KEY WORD FOR THIS PART OF THE
FORECAST. DESPITE GOOD MODEL AGREEMENT WITH THE SYNOPTIC
PLAYERS...SUBTLE DIFFERENCES IN TEMP PROFILES GIVE US THE WHOLE
RANGE OF P-TYPE POSSIBILITIES DURING THE NIGHT. IF THAT WERE NOT
ENOUGH QPF AMOUNTS ARE ALSO HIGHER VARIABLE. WILL TACKLE EACH
ISSUE SEPARATELY FOR NOW.
P TYPE...THE EURO REMAINS THE COLDEST OF ALL MODELS SHOWING A
MOSTLY SNOW EVENT FOR MOST OF THE CWA UNTIL CLOSER TO DAYBREAK
WHEN WARMER AIR AROUND 850 MB MAKES ITS WAY INTO THE POCONOS.
MEANWHILE THE GFS AND NAM ARE FAIRLY SIMILAR IN THAT THEY SHOW A
TONGUE OF WARMER AIR AROUND 850 MB MOVE IN. THAT WOULD IMPLY ANY
SNOW WOULD EVENTUALLY MIX WITH SLEET/FREEZING RAIN AND PLAIN
RAIN. A FEW ITEMS THAT WE WILL BE WATCHING. THIS LAYER OF WARMER
AIR ALOFT MAY BE ABLE TO BE OVERCOME FOR A PERIOD DURING THE NIGHT
WHEN LIFT IS MAXIMIZED AND DYNAMIC COOLING ALLOWS FOR A SWITCH
OVER TO ALL SNOW. WITH TEMP PROFILES SO CLOSE..THIS MAY BE JUST
ENOUGH...ESPECIALLY OVER THE HIGHER TERRAIN OF THE CATSKILLS AND
WESTERN SOUTHERN TIER FOR A PERIOD OF HEAVIER SNOW. HOWEVER...IF THE NAM
AND GFS ARE CORRECT WITH THIS WARMER LAYER ALOFT...FREEZING RAIN
POTENTIAL WILL HAVE TO BE WATCHED CAREFULLY. MOST MODEL SOUNDINGS
SHOW SURFACE TEMPS NEAR OR BELOW FREEZING FROM ABOUT 04Z THROUGH
12Z...WITH MODEL QPFS AROUND A HALF OF AN INCH. CONFIDENCE HOWEVER
IN THIS ICE POTENTIAL IS LOW GIVEN THE MODEL UNCERTAINTY WITH
P-TYPE. IN ADDITION THOSE MODELS THAT SUGGEST THE WARMER LAYER
ALOFT...ALSO SHOW A FAIRLY DEEP LAYER OF COLDER AIR BELOW THIS WARM
NOSE WHICH WOULD SUGGEST PROLONGED SLEET VERSUS FREEZING RAIN. IF
THE FREEZING RAIN DOES PAN OUT...THE POSITION OF THE SURFACE HIGH
OVER NOVA SCOTIA WOULD GIVE US MORE OF AN EASTERLY COMPONENT TO
THE SURFACE WIND WHICH MAY NOT LOCK IN THE COLD AIR AS MUCH FOR
THE MAJORITY OF THE CWA...ASIDE FROM THE MOHAWK VALLEY WHERE IT IS
IDEAL. WITH SO MUCH UNCERTAINTY PLAYED THE GRIDS TO SHOW THIS.
PLAYED A WINTRY MIX FOR MOST OF THE AREA THROUGH THE NIGHT. BOTH
THE EURO/NAM/AND GFS DO SHOW WARMER AIR MOVING INTO NEPA SO HERE I
REMOVED THE MENTION OF SNOW OR SLEET IN THE WYOMING VALLEY TOWARD
12Z WITH ICE REMAINING IN THE POCONOS. WOULD LOVE TO BE MORE
SPECIFIC BUT SOMETIMES WE JUST DON`T KNOW THIS FAR OUT YET AND DO
NOT WANT TO CONVEY THAT WE KNOW THE EXACT P-TYPES THAT WILL FALL.
QPF...THE NAM APPEARS TO BE WAY OVERDONE WITH QPF WITH VALUES OF
BETWEEN .75" AND AN INCH BY 12Z WEDNESDAY. THE EURO IS ABOUT HALF
THAT OR AROUND A HALF OF AN INCH...WITH THE SREFS AND GFS IN THE
MIDDLE (.50-.75). PER COORDINATION WITH THE OTHER OFFICES DECIDED
TO HOLD OFF ON ANY WATCHES WITH TOO MUCH UNCERTAINTY REGARDING
P-TYPE.
WEDNESDAY....SURFACE COLD AIR MAY REMAIN ACROSS THE MOHAWK VALLEY
AND PARTS OF SULLIVAN COUNTY WITH THE EASTERLY FLOW...OTHERWISE
WARM BOUNDARY LAYER TEMPS SUPPORT A CHANGE TO MOSTLY RAIN DURING
THE DAY. TOWARD 0Z AS COLDER AIR MOVES IN FROM THE WEST SOME WET
SNOW IS POSSIBLE. STILL SOME UNCERTAINTY HERE HOWEVER GIVEN THE
EURO IS MUCH COLDER AND WOULD SUPPORT SNOW THROUGHOUT MOST OF THE DAY.
WILL STICK WITH CONTINUITY FROM THE PREVIOUS FORECAST AS IT IS
SUPPORTED BY THE GFS AND NAM...ALONG WITH MAIN SURFACE LOW TRACK
BEING TO OUR WEST AND NOT A FAVORABLE POSITION OF THE SURFACE
HIGH FOR ALL SNOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
XTNDD PD DOMINATED BY A MEANDERING UPR LVL LOW AND COOL AIR. LOW
INITIALLY DRIFTS EAST EARLY IN THE PD...BUT IS REPLACED BY A
SCNDRY LOW WHICH ROTATES BACK AROUND TROF INTO THE AREA. GFS IS A
BIT MORE PROGRESSIVE THRU THE PD BUT WLD STILL KEEP THE AREA IN A
NLY FLOW WITH DEEP MOISTURE. THERE/S NOT ANY STRONG LIFT WITH THE
UPR LOW SO PCPN WILL BE LGT...BUT PERSISTENT. ALSO...TEMPS UNDER
THE LOW SLOWLY MODIFY...WITH THE ECMWF BEING COOLER MAINTAINING
THE UPR TROF. GNRLY FLWD THE HPC GUID THRU THE PD WHICH WAS CLOSER
TO THE ECMWF...HWVR...DID ADJUST SLGTLY WRMR FOR COLLABORATION
AND TO EDGE TWRD THE GFS.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
18Z MON UPDATE... LWR CLDS (MVFR CIGS AT MOST SITES) WILL PERSIST
THROUGH THIS EVE. LTR TNT (GENERALLY IN THE 03-09Z TIME
FRAME)...SOME DRIER AIR AT LWR LVLS SHOULD BUILD IN...WITH
CLEARING SKIES ANTICIPATED AT THAT TIME.
VFR SHOULD THEN HOLD FOR THE REMAINDER OF THE VALID TAF PD (18Z
TUE). THE NEXT ROUND OF WINTRY PCPN SHOULD HOLD OFF TIL LATE IN
THE DAY TUE...OR EARLY IN THE EVE (22Z OR LATER).
N TO NW WINDS 5-10 KT THIS AFTN...WILL TURN LGT AND VRBL
TNT...BEFORE SHIFTING INTO THE SE TUE AM AT 5-10 KT.
.OUTLOOK...
TUE NGT/WED MRNG...MVFR TO IFR LIKELY...WITH A WINTRY MIX OF PCPN
TYPES (SNOW/SLEET/FRZG RAIN).
WED AFTN THRU FRI...RESTRICTIONS ARE LIKELY TO CONTINUE...WITH PDS
OF LIGHT RAIN OR SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MLJ/MDP
SHORT TERM...HEDEN
LONG TERM...DGM
AVIATION...MLJ
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1206 PM EST MON FEB 25 2013
.SYNOPSIS...
LAKE EFFECT CLOUDS AND SCATTERED FLURRIES THIS MORNING...MAINLY IN
CENTRAL NEW YORK...WILL YIELD TO BUILDING HIGH PRESSURE THIS
AFTERNOON. THIS WILL HELP BREAK UP THE CLOUDS LATER TODAY...AND
KEEP THINGS DRY AND QUIET TONIGHT THROUGH MOST OF TUESDAY.
HOWEVER...A MIX OF WINTRY PRECIPITATION IS LIKELY LATE TUESDAY
THROUGH EARLY WEDNESDAY AS LOW PRESSURE MOVES TOWARDS THE REGION
FROM THE OHIO VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE... VSBL SAT ANIMATION INDICATES THAT CLDS ARE
HANGING TOUGH LATE THIS MRNG ACRS CNY/PTNS OF NE PA. THE LATEST
HI-RES NWP GUIDANCE STILL INDICATES THAT SOME DRYING WILL TAKE
PLACE DURG THE COURSE OF THE AFTN...SPCLY FROM THE TWIN TIERS SWD.
WE BLENDED IN THE LATEST RUC13 DATA...WHICH SEEMS TO HAVE A GOOD
HANDLE ON THE CURRENT EVOLUTION. ANY LINGERING FLRYS SHOULD BE
GONE BY 18-19Z.
BASED ON THE 12Z RAOBS AND WEAK ANTICIPATED THERMAL ADVECTION THIS
AFTN...OUR PRESENT HIGH TEMP FCST LOOKS GOOD...AND WAS ONLY
TWEAKED VERY SLIGHTLY.
PREV DISC... 630 AM UPDATE... GRIDS TWEAKED AS PER CURRENT
OBS...AND TO LINGER CLOUD COVER A BIT LONGER INTO THE AFTERNOON.
FORECAST GENERALLY ON TRACK...WITH ONLY SCATTERED FLURRIES
REMAINING DOWNWIND OF LAKE ONTARIO.
EARLIER DISCUSSION... ATMOSPHERIC COLUMN AS A WHOLE IS DRYING OUT...YET
MOISTURE REMAINS TRAPPED IN THE LOWEST FEW THOUSAND FEET AGL UNDER
A WEAK INVERSION. 850MB TEMPERATURES ARE ABOUT 9 OR 10 BELOW ZERO
CELSIUS...BARELY ENOUGH FOR THE WEAK LAKE RESPONSE OF SCATTERED
SNOW SHOWERS CURRENTLY DOWNWIND OF LAKE ONTARIO. WARM AIR
ADVECTION ALOFT WILL GRADUALLY RAISE 850MB TEMPERATURES HEADING
INTO THE DAY WHICH WILL ALLOW SNOW SHOWERS TO TAPER OFF TO A FEW
FLURRIES BEFORE ENDING. HOWEVER...STRATOCUMULUS WILL BE A BIT MORE
STUBBORN...ESPECIALLY CENTRAL NY. OVERALL...SUNSHINE WILL INCREASE
THROUGH THE DAY BUT WILL TAKE LONGER IN SOME PLACES THAN
OTHERS...AND HIGHS WILL BE RIGHT AROUND CLIMATOLOGICAL AVERAGES.
HIGH PRESSURE IN CHARGE TONIGHT FOR QUIET AND MOSTLY CLEAR
CONDITIONS. THE GOOD RADIATIONAL COOLING SET UP WILL YIELD MAINLY
LOWER 20S FOR LOWS...THOUGH SOME TEENS FOR THE MORE TYPICALLY
PRONE COLD AIR DRAINAGE VALLEYS. IN MANY CASES...AT OR SLIGHTLY
BELOW COLDEST MODEL GUIDANCE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
500 AM UPDATE...
TUESDAY....FAIRLY GOOD AGREEMENT AMONGST THE MODELS WITH REGARDS
TO SYNOPTIC FEATURES WITH A DOMINANT SURFACE LOW AROUND 995 MB
TRACKING THROUGH CENTRAL INDIANA WITH A NEW LOW FORMING OVER NORTH
CENTRAL NC BY 0Z WEDNESDAY. THIS IS THE EASIEST PART OF THE
FORECAST WITH THICKENING CLOUDS AND PRECIP HOLDING OFF UNTIL LATE
IN THE DAY. LOOKING FOR ARRIVAL OF PRECIP TOWARD 23Z FAR SOUTH AND
WEST. MODEL PROFILES SHOW WARM SURFACE TEMPS SO INITIAL SHOT OF
PRECIP COULD BE IN THE FORM OF SNOW...SLEET OR PLAIN RAIN.
TUESDAY NIGHT...UNCERTAINTY IS THE KEY WORD FOR THIS PART OF THE
FORECAST. DESPITE GOOD MODEL AGREEMENT WITH THE SYNOPTIC
PLAYERS...SUBTLE DIFFERENCES IN TEMP PROFILES GIVE US THE WHOLE
RANGE OF P-TYPE POSSIBILITIES DURING THE NIGHT. IF THAT WERE NOT
ENOUGH QPF AMOUNTS ARE ALSO HIGHER VARIABLE. WILL TACKLE EACH
ISSUE SEPARATELY FOR NOW.
P TYPE...THE EURO REMAINS THE COLDEST OF ALL MODELS SHOWING A
MOSTLY SNOW EVENT FOR MOST OF THE CWA UNTIL CLOSER TO DAYBREAK
WHEN WARMER AIR AROUND 850 MB MAKES ITS WAY INTO THE POCONOS.
MEANWHILE THE GFS AND NAM ARE FAIRLY SIMILAR IN THAT THEY SHOW A
TONGUE OF WARMER AIR AROUND 850 MB MOVE IN. THAT WOULD IMPLY ANY
SNOW WOULD EVENTUALLY MIX WITH SLEET/FREEZING RAIN AND PLAIN
RAIN. A FEW ITEMS THAT WE WILL BE WATCHING. THIS LAYER OF WARMER
AIR ALOFT MAY BE ABLE TO BE OVERCOME FOR A PERIOD DURING THE NIGHT
WHEN LIFT IS MAXIMIZED AND DYNAMIC COOLING ALLOWS FOR A SWITCH
OVER TO ALL SNOW. WITH TEMP PROFILES SO CLOSE..THIS MAY BE JUST
ENOUGH...ESPECIALLY OVER THE HIGHER TERRAIN OF THE CATSKILLS AND
WESTERN SOUTHERN TIER FOR A PERIOD OF HEAVIER SNOW. HOWEVER...IF THE NAM
AND GFS ARE CORRECT WITH THIS WARMER LAYER ALOFT...FREEZING RAIN
POTENTIAL WILL HAVE TO BE WATCHED CAREFULLY. MOST MODEL SOUNDINGS
SHOW SURFACE TEMPS NEAR OR BELOW FREEZING FROM ABOUT 04Z THROUGH
12Z...WITH MODEL QPFS AROUND A HALF OF AN INCH. CONFIDENCE HOWEVER
IN THIS ICE POTENTIAL IS LOW GIVEN THE MODEL UNCERTAINTY WITH
P-TYPE. IN ADDITION THOSE MODELS THAT SUGGEST THE WARMER LAYER
ALOFT...ALSO SHOW A FAIRLY DEEP LAYER OF COLDER AIR BELOW THIS WARM
NOSE WHICH WOULD SUGGEST PROLONGED SLEET VERSUS FREEZING RAIN. IF
THE FREEZING RAIN DOES PAN OUT...THE POSITION OF THE SURFACE HIGH
OVER NOVA SCOTIA WOULD GIVE US MORE OF AN EASTERLY COMPONENT TO
THE SURFACE WIND WHICH MAY NOT LOCK IN THE COLD AIR AS MUCH FOR
THE MAJORITY OF THE CWA...ASIDE FROM THE MOHAWK VALLEY WHERE IT IS
IDEAL. WITH SO MUCH UNCERTAINTY PLAYED THE GRIDS TO SHOW THIS.
PLAYED A WINTRY MIX FOR MOST OF THE AREA THROUGH THE NIGHT. BOTH
THE EURO/NAM/AND GFS DO SHOW WARMER AIR MOVING INTO NEPA SO HERE I
REMOVED THE MENTION OF SNOW OR SLEET IN THE WYOMING VALLEY TOWARD
12Z WITH ICE REMAINING IN THE POCONOS. WOULD LOVE TO BE MORE
SPECIFIC BUT SOMETIMES WE JUST DON`T KNOW THIS FAR OUT YET AND DO
NOT WANT TO CONVEY THAT WE KNOW THE EXACT P-TYPES THAT WILL FALL.
QPF...THE NAM APPEARS TO BE WAY OVERDONE WITH QPF WITH VALUES OF
BETWEEN .75" AND AN INCH BY 12Z WEDNESDAY. THE EURO IS ABOUT HALF
THAT OR AROUND A HALF OF AN INCH...WITH THE SREFS AND GFS IN THE
MIDDLE (.50-.75). PER COORDINATION WITH THE OTHER OFFICES DECIDED
TO HOLD OFF ON ANY WATCHES WITH TOO MUCH UNCERTAINTY REGARDING
P-TYPE.
WEDNESDAY....SURFACE COLD AIR MAY REMAIN ACROSS THE MOHAWK VALLEY
AND PARTS OF SULLIVAN COUNTY WITH THE EASTERLY FLOW...OTHERWISE
WARM BOUNDARY LAYER TEMPS SUPPORT A CHANGE TO MOSTLY RAIN DURING
THE DAY. TOWARD 0Z AS COLDER AIR MOVES IN FROM THE WEST SOME WET
SNOW IS POSSIBLE. STILL SOME UNCERTAINTY HERE HOWEVER GIVEN THE
EURO IS MUCH COLDER AND WOULD SUPPORT SNOW THROUGHOUT MOST OF THE DAY.
WILL STICK WITH CONTINUITY FROM THE PREVIOUS FORECAST AS IT IS
SUPPORTED BY THE GFS AND NAM...ALONG WITH MAIN SURFACE LOW TRACK
BEING TO OUR WEST AND NOT A FAVORABLE POSITION OF THE SURFACE
HIGH FOR ALL SNOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
130 PM UPDATE...
AS FRONT MVS THRU ON WEDNESDAY, CWA WL BE UNDER THE INFLUENCE OF H5
LOW CLOSING OFF ACRS NERN U.S. MED RANGE GUIDANCE CONTS TO SUGGEST
THIS WL HAPPEN BY MID-WEEK AND EVENTUALLY HEAD EAST LATE IN THE
WEEK (PER 00Z/12Z EURO) OR HANG OUT THRU THE WEEKEND (PER 12Z GFS).
MAIN DIFFERENCES CNTR AROUND H5 HEIGHTS BEGINNING LATE IN THE
WEEK WITH EURO DROPPING WAVE INTO THE INTERMOUNTAIN WEST WHILE GFS
IS QUICKER WITH THIS WV AND MVS IT INTO THE DAKOTAS AT 12Z
THURSDAY. BY 00Z FRIDAY, ECMWF APPEARS TO TREAT IT AS A KICKER AND
KICKS THE UL TO THE EAST. GFS ALLOWS THIS WV TO GET ABSORBED AS IT
DROPS INTO THE TN VLY AND JUST RE-INTENSIFIES THE LOW OVR TOP OF
US. THE LATEST GFS IS QUITE A CHG FM ITS 06Z RUN AS IT APPEARED TO
BE IN LOCK-STEP WITH ECMWF. THUS, HV FOLLOWED 12Z EURO DUE TO ITS
CONSISTENCY WITH THE 00Z RUN.
EITHER WAY, SCTD POPS EXPECTED FM THURSDAY ON IN ONE FORM OR
ANOTHER, GENERALLY A RAIN/SNOW SHOWER MIX DRG THE DAYLIGHT HOURS
AND SNOW SHOWERS AT NIGHT. GIVEN THE EXTENSIVE CLD CVR EXPECTED
AND NW FLOW WORKING IN, TEMPS WL BE FAIRLY STEADY THRU THE PD WITH
ONLY A DEGREE OR TWO CHANGE BTWN THE OVRNGT LOWS AND AFTN HIGHS.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
18Z MON UPDATE... LWR CLDS (MVFR CIGS AT MOST SITES) WILL PERSIST
THROUGH THIS EVE. LTR TNT (GENERALLY IN THE 03-09Z TIME
FRAME)...SOME DRIER AIR AT LWR LVLS SHOULD BUILD IN...WITH
CLEARING SKIES ANTICIPATED AT THAT TIME.
VFR SHOULD THEN HOLD FOR THE REMAINDER OF THE VALID TAF PD (18Z
TUE). THE NEXT ROUND OF WINTRY PCPN SHOULD HOLD OFF TIL LATE IN
THE DAY TUE...OR EARLY IN THE EVE (22Z OR LATER).
N TO NW WINDS 5-10 KT THIS AFTN...WILL TURN LGT AND VRBL
TNT...BEFORE SHIFTING INTO THE SE TUE AM AT 5-10 KT.
.OUTLOOK...
TUE NGT/WED MRNG...MVFR TO IFR LIKELY...WITH A WINTRY MIX OF PCPN
TYPES (SNOW/SLEET/FRZG RAIN).
WED AFTN THRU FRI...RESTRICTIONS ARE LIKELY TO CONTINUE...WITH PDS
OF LIGHT RAIN OR SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MLJ/MDP
SHORT TERM...HEDEN
LONG TERM...PVN
AVIATION...MLJ
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1056 AM EST MON FEB 25 2013
.SYNOPSIS...
LAKE EFFECT CLOUDS AND SCATTERED FLURRIES THIS MORNING...MAINLY IN
CENTRAL NEW YORK...WILL YIELD TO BUILDING HIGH PRESSURE THIS
AFTERNOON. THIS WILL HELP BREAK UP THE CLOUDS LATER TODAY...AND
KEEP THINGS DRY AND QUIET TONIGHT THROUGH MOST OF TUESDAY.
HOWEVER...A MIX OF WINTRY PRECIPITATION IS LIKELY LATE TUESDAY
THROUGH EARLY WEDNESDAY AS LOW PRESSURE MOVES TOWARDS THE REGION
FROM THE OHIO VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE... VSBL SAT ANIMATION INDICATES THAT CLDS ARE
HANGING TOUGH LATE THIS MRNG ACRS CNY/PTNS OF NE PA. THE LATEST
HI-RES NWP GUIDANCE STILL INDICATES THAT SOME DRYING WILL TAKE
PLACE DURG THE COURSE OF THE AFTN...SPCLY FROM THE TWIN TIERS SWD.
WE BLENDED IN THE LATEST RUC13 DATA...WHICH SEEMS TO HAVE A GOOD
HANDLE ON THE CURRENT EVOLUTION. ANY LINGERING FLRYS SHOULD BE
GONE BY 18-19Z.
BASED ON THE 12Z RAOBS AND WEAK ANTICIPATED THERMAL ADVECTION THIS
AFTN...OUR PRESENT HIGH TEMP FCST LOOKS GOOD...AND WAS ONLY
TWEAKED VERY SLIGHTLY.
PREV DISC... 630 AM UPDATE... GRIDS TWEAKED AS PER CURRENT
OBS...AND TO LINGER CLOUD COVER A BIT LONGER INTO THE AFTERNOON.
FORECAST GENERALLY ON TRACK...WITH ONLY SCATTERED FLURRIES
REMAINING DOWNWIND OF LAKE ONTARIO.
EARLIER DISCUSSION... ATMOSPHERIC COLUMN AS A WHOLE IS DRYING OUT...YET
MOISTURE REMAINS TRAPPED IN THE LOWEST FEW THOUSAND FEET AGL UNDER
A WEAK INVERSION. 850MB TEMPERATURES ARE ABOUT 9 OR 10 BELOW ZERO
CELSIUS...BARELY ENOUGH FOR THE WEAK LAKE RESPONSE OF SCATTERED
SNOW SHOWERS CURRENTLY DOWNWIND OF LAKE ONTARIO. WARM AIR
ADVECTION ALOFT WILL GRADUALLY RAISE 850MB TEMPERATURES HEADING
INTO THE DAY WHICH WILL ALLOW SNOW SHOWERS TO TAPER OFF TO A FEW
FLURRIES BEFORE ENDING. HOWEVER...STRATOCUMULUS WILL BE A BIT MORE
STUBBORN...ESPECIALLY CENTRAL NY. OVERALL...SUNSHINE WILL INCREASE
THROUGH THE DAY BUT WILL TAKE LONGER IN SOME PLACES THAN
OTHERS...AND HIGHS WILL BE RIGHT AROUND CLIMATOLOGICAL AVERAGES.
HIGH PRESSURE IN CHARGE TONIGHT FOR QUIET AND MOSTLY CLEAR
CONDITIONS. THE GOOD RADIATIONAL COOLING SET UP WILL YIELD MAINLY
LOWER 20S FOR LOWS...THOUGH SOME TEENS FOR THE MORE TYPICALLY
PRONE COLD AIR DRAINAGE VALLEYS. IN MANY CASES...AT OR SLIGHTLY
BELOW COLDEST MODEL GUIDANCE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
500 AM UPDATE...
TUESDAY....FAIRLY GOOD AGREEMENT AMONGST THE MODELS WITH REGARDS
TO SYNOPTIC FEATURES WITH A DOMINANT SURFACE LOW AROUND 995 MB
TRACKING THROUGH CENTRAL INDIANA WITH A NEW LOW FORMING OVER NORTH
CENTRAL NC BY 0Z WEDNESDAY. THIS IS THE EASIEST PART OF THE
FORECAST WITH THICKENING CLOUDS AND PRECIP HOLDING OFF UNTIL LATE
IN THE DAY. LOOKING FOR ARRIVAL OF PRECIP TOWARD 23Z FAR SOUTH AND
WEST. MODEL PROFILES SHOW WARM SURFACE TEMPS SO INITIAL SHOT OF
PRECIP COULD BE IN THE FORM OF SNOW...SLEET OR PLAIN RAIN.
TUESDAY NIGHT...UNCERTAINTY IS THE KEY WORD FOR THIS PART OF THE
FORECAST. DESPITE GOOD MODEL AGREEMENT WITH THE SYNOPTIC
PLAYERS...SUBTLE DIFFERENCES IN TEMP PROFILES GIVE US THE WHOLE
RANGE OF P-TYPE POSSIBILITIES DURING THE NIGHT. IF THAT WERE NOT
ENOUGH QPF AMOUNTS ARE ALSO HIGHER VARIABLE. WILL TACKLE EACH
ISSUE SEPARATELY FOR NOW.
P TYPE...THE EURO REMAINS THE COLDEST OF ALL MODELS SHOWING A
MOSTLY SNOW EVENT FOR MOST OF THE CWA UNTIL CLOSER TO DAYBREAK
WHEN WARMER AIR AROUND 850 MB MAKES ITS WAY INTO THE POCONOS.
MEANWHILE THE GFS AND NAM ARE FAIRLY SIMILAR IN THAT THEY SHOW A
TONGUE OF WARMER AIR AROUND 850 MB MOVE IN. THAT WOULD IMPLY ANY
SNOW WOULD EVENTUALLY MIX WITH SLEET/FREEZING RAIN AND PLAIN
RAIN. A FEW ITEMS THAT WE WILL BE WATCHING. THIS LAYER OF WARMER
AIR ALOFT MAY BE ABLE TO BE OVERCOME FOR A PERIOD DURING THE NIGHT
WHEN LIFT IS MAXIMIZED AND DYNAMIC COOLING ALLOWS FOR A SWITCH
OVER TO ALL SNOW. WITH TEMP PROFILES SO CLOSE..THIS MAY BE JUST
ENOUGH...ESPECIALLY OVER THE HIGHER TERRAIN OF THE CATSKILLS AND
WESTERN SOUTHERN TIER FOR A PERIOD OF HEAVIER SNOW. HOWEVER...IF THE NAM
AND GFS ARE CORRECT WITH THIS WARMER LAYER ALOFT...FREEZING RAIN
POTENTIAL WILL HAVE TO BE WATCHED CAREFULLY. MOST MODEL SOUNDINGS
SHOW SURFACE TEMPS NEAR OR BELOW FREEZING FROM ABOUT 04Z THROUGH
12Z...WITH MODEL QPFS AROUND A HALF OF AN INCH. CONFIDENCE HOWEVER
IN THIS ICE POTENTIAL IS LOW GIVEN THE MODEL UNCERTAINTY WITH
P-TYPE. IN ADDITION THOSE MODELS THAT SUGGEST THE WARMER LAYER
ALOFT...ALSO SHOW A FAIRLY DEEP LAYER OF COLDER AIR BELOW THIS WARM
NOSE WHICH WOULD SUGGEST PROLONGED SLEET VERSUS FREEZING RAIN. IF
THE FREEZING RAIN DOES PAN OUT...THE POSITION OF THE SURFACE HIGH
OVER NOVA SCOTIA WOULD GIVE US MORE OF AN EASTERLY COMPONENT TO
THE SURFACE WIND WHICH MAY NOT LOCK IN THE COLD AIR AS MUCH FOR
THE MAJORITY OF THE CWA...ASIDE FROM THE MOHAWK VALLEY WHERE IT IS
IDEAL. WITH SO MUCH UNCERTAINTY PLAYED THE GRIDS TO SHOW THIS.
PLAYED A WINTRY MIX FOR MOST OF THE AREA THROUGH THE NIGHT. BOTH
THE EURO/NAM/AND GFS DO SHOW WARMER AIR MOVING INTO NEPA SO HERE I
REMOVED THE MENTION OF SNOW OR SLEET IN THE WYOMING VALLEY TOWARD
12Z WITH ICE REMAINING IN THE POCONOS. WOULD LOVE TO BE MORE
SPECIFIC BUT SOMETIMES WE JUST DON`T KNOW THIS FAR OUT YET AND DO
NOT WANT TO CONVEY THAT WE KNOW THE EXACT P-TYPES THAT WILL FALL.
QPF...THE NAM APPEARS TO BE WAY OVERDONE WITH QPF WITH VALUES OF
BETWEEN .75" AND AN INCH BY 12Z WEDNESDAY. THE EURO IS ABOUT HALF
THAT OR AROUND A HALF OF AN INCH...WITH THE SREFS AND GFS IN THE
MIDDLE (.50-.75). PER COORDINATION WITH THE OTHER OFFICES DECIDED
TO HOLD OFF ON ANY WATCHES WITH TOO MUCH UNCERTAINTY REGARDING
P-TYPE.
WEDNESDAY....SURFACE COLD AIR MAY REMAIN ACROSS THE MOHAWK VALLEY
AND PARTS OF SULLIVAN COUNTY WITH THE EASTERLY FLOW...OTHERWISE
WARM BOUNDARY LAYER TEMPS SUPPORT A CHANGE TO MOSTLY RAIN DURING
THE DAY. TOWARD 0Z AS COLDER AIR MOVES IN FROM THE WEST SOME WET
SNOW IS POSSIBLE. STILL SOME UNCERTAINTY HERE HOWEVER GIVEN THE
EURO IS MUCH COLDER AND WOULD SUPPORT SNOW THROUGHOUT MOST OF THE DAY.
WILL STICK WITH CONTINUITY FROM THE PREVIOUS FORECAST AS IT IS
SUPPORTED BY THE GFS AND NAM...ALONG WITH MAIN SURFACE LOW TRACK
BEING TO OUR WEST AND NOT A FAVORABLE POSITION OF THE SURFACE
HIGH FOR ALL SNOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
130 PM UPDATE...
AS FRONT MVS THRU ON WEDNESDAY, CWA WL BE UNDER THE INFLUENCE OF H5
LOW CLOSING OFF ACRS NERN U.S. MED RANGE GUIDANCE CONTS TO SUGGEST
THIS WL HAPPEN BY MID-WEEK AND EVENTUALLY HEAD EAST LATE IN THE
WEEK (PER 00Z/12Z EURO) OR HANG OUT THRU THE WEEKEND (PER 12Z GFS).
MAIN DIFFERENCES CNTR AROUND H5 HEIGHTS BEGINNING LATE IN THE
WEEK WITH EURO DROPPING WAVE INTO THE INTERMOUNTAIN WEST WHILE GFS
IS QUICKER WITH THIS WV AND MVS IT INTO THE DAKOTAS AT 12Z
THURSDAY. BY 00Z FRIDAY, ECMWF APPEARS TO TREAT IT AS A KICKER AND
KICKS THE UL TO THE EAST. GFS ALLOWS THIS WV TO GET ABSORBED AS IT
DROPS INTO THE TN VLY AND JUST RE-INTENSIFIES THE LOW OVR TOP OF
US. THE LATEST GFS IS QUITE A CHG FM ITS 06Z RUN AS IT APPEARED TO
BE IN LOCK-STEP WITH ECMWF. THUS, HV FOLLOWED 12Z EURO DUE TO ITS
CONSISTENCY WITH THE 00Z RUN.
EITHER WAY, SCTD POPS EXPECTED FM THURSDAY ON IN ONE FORM OR
ANOTHER, GENERALLY A RAIN/SNOW SHOWER MIX DRG THE DAYLIGHT HOURS
AND SNOW SHOWERS AT NIGHT. GIVEN THE EXTENSIVE CLD CVR EXPECTED
AND NW FLOW WORKING IN, TEMPS WL BE FAIRLY STEADY THRU THE PD WITH
ONLY A DEGREE OR TWO CHANGE BTWN THE OVRNGT LOWS AND AFTN HIGHS.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
12Z UPDATE...
MOISTURE REMAINS TRAPPED UNDER INVERSION...WITH LIGHT NORTHWEST
FLOW OFF OF LAKE ONTARIO ALLOWING AT LEAST MVFR CIGS TO
PERSIST...AND EVEN STILL BRIEFLY IFR CIG KBGM AND KRME. GRADUAL
IMPROVEMENT AND EVENTUAL SCATTERING OUT WILL OCCUR DURING THE
AFTERNOON AS DRY AIR AND NEUTRALIZING INVERSION WIN OUT. CLEARING
AND QUIET TONIGHT. THOUGH NOT IN TAFS DUE TO UNCERTAINTY...SOME
MIST NOT OUT OF THE QUESTION FOR VALLEY TERMINALS DURING PREDAWN
HOURS TUESDAY MORNING.
.OUTLOOK...
TUE...VFR...THEN MVFR ENCROACHING FROM SW LATE TUE AFTN.
TUE NGT/WED MRNG...IFR/MVFR AND WINTRY MIX FROM LARGE SYSTEM.
WED AFTN THRU FRI...IFR/MVFR IN INTERMITTENT SNOW AND RAIN SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MLJ/MDP
SHORT TERM...HEDEN
LONG TERM...PVN
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
731 PM EST TUE FEB 26 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH THE AREA FROM THE WEST OVERNIGHT...AS
LOW PRESSURE MOVES ACROSS TO THE WEST AND NORTH OF THE AREA. SLOW
MOVING LOW PRESSURE OVER THE NORTHEAST WILL CIRCULATE A WESTERLY
FLOW OF COLD AIR ACROSS THE REGION THURSDAY INTO THE WEEKEND. A
SERIES OF LOW PRESSURE SYSTEMS WILL DEVELOP OFF THE SOUTHEAST AND
MID ATLANTIC COASTS OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WATCHING CLOSELY THE CONVECTION THAT HAS DEVELOPED IN THE VCNTY
OF SFC TROF OVER THE PIEDMONT. NO LTG SEEN AS YET BUT THESE STORMS
HAD KNOCKED SOME TREES DOWN AS THEY MOVE NEAR FLORENCE SC EARLIER
THIS EVE BUT NO RECENT DAMAGE HAS BEEN REPORTED. VERY SHORT RANGE
MODEL GUIDANCE VIA HRRR AND RAP SUGGESTS THE STORMS WEAKEN AS
INSTABILITY REMAINS LACKING GOING INTO THE EVENING HOURS. VERY
STRONG WINDS OF 40-50KT ARE BEING OBSERVED JUST ABOVE THE SURFACE
AND ANY WEAK CONVECTION MAY BE ABLE TO BRING THESE DOWN AND CAUSE
SOME MINOR DAMAGE THIS EVE.
TEMPS WILL CONTINUE NON-DIURNAL TREND THIS EVENING...THEN WILL DROP
OVERNIGHT WITH PASSAGE OF COLD FRONT. WENT WITH MOS BLEND...UPR 40S
INLAND TO LOWER 50S COAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 330 PM WEDNESDAY...MOSTLY SUNNY AND DRYING CONDITIONS EXPECTED
WITH MODERATE SW WINDS...AS AREA WILL BE INFLUENCED BY BROAD
CIRCULATION AROUND CONSOLIDATING LOW PRES OVER NEW ENGLAND. OFFSHORE
WINDS WILL ALLOW TEMPS TO RISE BACK INTO LOW-MID 60S INLAND AS
COLDER AIR MASS IS HELD OFF UNTIL WED NIGHT AND THU.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 345 PM TUE...LOW PRES ACROSS THE GREAT LAKES WILL REMAIN
NEARLY STATIONARY WED NIGHT THROUGH THU WHICH WILL RESULT IN
TIGHTENED PRESSURE GRADIENT ACROSS EASTERN NC. FOR THUR...GUSTY
WESTERLY WINDS IN WELL MIXED BOUNDARY LAYER WILL SUPPORT HIGHS WELL
INTO THE 50S FOR THE AREA...AS DOWNSLOPING COMPONENT OFF SRN
APPALACHIANS HELPS DRY THE LOWER ATMS. FRONT/SHORTWAVE WILL MIGRATE
THROUGH THUR EVE. AT THIS TIME MOISTURE STILL APPEARS TO BE
LIMITED...SO WILL CONTINUE TO LEAVE OUT PRECIP MENTION...JUST AN
INCREASE IN CLOUD COVER AND COOLER AIRMASS. COOLER TEMPS EXPECTED
FRI GENERALLY UPPER 40S TO LOWER 50S FOR HIGHS...AND LOWS IN THE 30S
FRI MORNING.
ANOMALOUS DEEP TROUGHING WILL BE IN PLACE THIS COMING WEEKEND AND
TEMPS WILL BE QUITE A BIT COOLER THAN CLIMO. HAVE UNDERSHOT COOLEST
ECMWF MOS GUIDANCE BY SEVERAL DEGREES DUE TO WARM BIAS TOWARDS CLIMO
IN MOS OUTPUT. HIGH WILL GENERALLY BE IN THE 40S WITH LOWS NEAR
FREEZING. HAVE CONTINUED TO MENTION SLIGHT CHANCE POPS SAT INTO SAT
NIGHT AS DEEP UPPER LOW ROTATES THROUGH E NC...THOUGH ATTM MOISTURE
PRESENCE IS QUESTIONABLE AS NO REAL SFC FEATURE IS PRESENT. GFS
CONTINUES TO BE AN OUTLIER IN SPINNING UP SFC LOW NEAR THE COAST...
OPER GFS LACKS SUPPORT FROM ITS 26/00Z ENSEMBLE MEAN...OPER ECM AND
ECM ENSEMBLE MEAN SO HAVE CONTINUED TO KEEP NO HIGHER THAN 20 POPS
IN GRIDS. IF PRECIP OCCURS...COULD CERTAINLY BE A RAIN/SNOW MIX
INLAND AS BOUNDARY LAYER TEMPS COULD BE JUST COLD ENOUGH TO SUPPORT
THE WINTRY MIX SAT NIGHT. AT THIS TIME BELIEVE TEMPS WILL BE JUST
WARM ENOUGH TO KEEP PRECIP ALL RAIN ALONG THE COAST. UPPER TROUGH
WILL MOVE OFF THE EAST COAST SUN NIGHT INTO MON. A SLIGHT WARMUP
POSSIBLE BY TUE AS COLD UPPER LOW PULLS AWAY FROM THE REGION...
THOUGH INDICATIONS ARE TO BE REPLACED BY REINFORCING COLD BY MID
NEXT WEEK AS INDICIES INDICATE A CONTINUED BELOW NORMAL TEMP PATTERN.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH 18Z WEDNESDAY/...
CEILINGS HAVE LIFTED IN THE DEVELOPING DRY SLOT WORKING THRU
EASTERN NC ATTM WITH CIGS NOW MVFR OR VFR AND IMPROVING. CONVECTION
TO THE WEST SHUD BE WEAKENING BUT MAY SEE A BRIEF GUSTY SHOWER
MOVE THRU THE TERMINALS 02-04Z. EXPECTED A PERIOD OF LOW
CLOUDS/FOG TO BRIEFLY PRODUCE LIFR/IFR CONDITIONS DURING THE LATE
EVENING AND VERY EARLY MORN BEFORE DEEPER DRYING MOVES IN WITH
PASSAGE OF UPPER TROF IN THE 07-08Z TIME FRAME. VFR EXPECTED
THEREAFTER THRU WED AS HIGH PRES BUILDS IN ALTHO WIND GUSTS 20-25
LIKELY FROM MID MORNING THRU MID AFTN COINCIDENT WITH BEST MIXING.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 345 PM TUE...MAINLY VFR THROUGH THE EXTENDED PERIOD. SOME INC
IN CLOUDINESS WED NIGHT THOUGH SHOULD REMAIN VFR. GUSTY WESTERLY
WINDS EXPECTED THUR LATE MORNING AND AFTERNOON. LIGHTER WINDS FOR
THE FRI THROUGH WEEKEND TIME PERIOD... WITH WINDS IN THE NW TO N
DIRECTION.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 PM TUESDAY...STRONG SCA CONDITIONS CONTINUING TO SPREAD
OVER AREA LATE THIS AFTN WITH WARM FRONT LIFTING N AS LOW PRES MOVES
N OVER INLAND SECTIONS. LATEST GDNC SUPPORTS PREVIOUS FCST WITH
STRONG SE TO S WINDS THIS EVENING...BECOMING SW AND SUBSIDING
OVERNIGHT. GUSTY SW FLOW WILL CONTINUE OVER AREA WED...PRIMARILY
OVER SRN AND CENTRAL WATERS.
LATEST WW3 AND SWAN/NWPS SUPPORT PREVIOUS FCST WITH SEAS BUILDING TO
10-13 FT THIS EVENING...THEN GRADUALLY SUBSIDING OVERNIGHT AND WED.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 345 PM TUE...UNSETTLED MARINE CONDITIONS EXPECTED TO CONTINUE
INTO FRIDAY. LOW PRES WILL REMAIN NEARLY STATIONARY THROUGH THU.
THIS WILL RESULT IN A CONTINUED TIGHTENED PRESSURE GRADIENT ACROSS
THE WATERS WITH MODERATE TO STRONG WINDS AT TIMES. WSW WINDS 15-25KT
WED NIGHT BECOME WLY THU. ELEVATED SEAS WILL CONTINUE THROUGH THU
NIGHT/FRI. GRADIENT WILL BEGIN TO RELAX FRI NIGHT WITH WINDS AND
SEAS SLOWLY SUBSIDING AS LOW MOVES OFF THE NE COAST. AN AREA OF LOW
PRESSURE MAY DEVELOP OFF THE SE COAST SUN...THOUGH THERE IS STILL
QUITE A BIT OF UNCERTAINTY WITH THIS FEATURE IN REGARDS TO
POSITIONING...STRENGTH...OR IF THE SYSTEM DEVELOPS. SHOULD
DEVELOPMENT OCCUR...WINDS WOULD BE STRONGER THAN CURRENTLY
ADVERTISED FOR SUN INTO MON.
&&
.TIDES/COASTAL FLOODING...
NO CHANGE TO HIGH SURF ADVISORY FOR THIS EVENING. STRONG SOUTHEAST
TO SOUTH FLOW WILL PRODUCE DANGEROUS ROUGH SURF ALONG THE COAST WITH
6 TO 8 FT BREAKERS EXPECTED.
SOME MINOR WATER RISES OF 1-2 FT WILL OCCUR OVER PORTIONS OF
MAINLAND HYDE...MAINLAND DARE...BEAUFORT...AND PAMLICO COUNTIES
ADJACENT TO THE PAMLICO SOUND DUE TO THE STRONG SOUTHERLY FLOW BUT
NO SIGNIFICANT ISSUES ARE EXPECTED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...HIGH SURF ADVISORY UNTIL 1 AM EST WEDNESDAY FOR NCZ095-098-103-
104.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST WEDNESDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR AMZ150-152-154-
156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...JBM/BTC
SHORT TERM...JBM
LONG TERM...TL
AVIATION...BTC/TL/LEP
MARINE...JBM/TL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
105 AM EST MON FEB 25 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST TONIGHT THEN MOVE
OFF THE MID ATLANTIC COAST ON MONDAY. A WARM FRONT WILL APPROACH
FROM THE SOUTH MONDAY NIGHT. LOW PRESSURE WILL DEVELOP ON THE WARM
FRONT TUESDAY AND PASS TO THE WEST WITH ITS TRAILING COLD FRONT
CROSSING TUESDAY NIGHT. A COLD TROUGH OF LOW PRESSURE WILL SETTLE
OVER THE MID ATLANTIC STATES WEDNESDAY THROUGH THE END OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 100 AM MONDAY...A WEAK EAST-WEST BOUNDARY NEAR THE PAMLICO
RIVER AS SEEN AS A FINE LINE IN THE DOPPLER RADAR IMAGERY..IS
MOVING RAPIDLY SOUTHWARD ACROSS EASTERN NC LATE TONIGHT. MAIN
EFFECT IS FOR WINDS TO INCREASE OUT OF THE NORTH AND NORTHEAST
BEHIND IT WHICH IS DISSIPATING THE PATCHES OF LOCALLY DENSE FOG
WHICH HAVE FORMED ACROSS THE AREA LATE IN THE EVENING. EXPECT MOST
IF NOT ALL OF THE FOG TO DIMINISHED BY 09Z. SKIES WILL BE CLEAR
FOR THE REMAINDER OF THE NIGHT BEHIND THE BOUNDARY AS HIGH
PRESSURE BUILDS INTO THE AREA FROM THE NORTH. TEMPERATURES STILL
EXPECTED TO FALL INTO THE MIDDLE AND UPPER 30S RANGING TO THE
MIDDLE 40S ALONG THE OUTER BANKS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM TUESDAY/...
LOW AMPLITUDE RIDGE CROSSES THE AREA MONDAY AS SFC HIGH MOVES
OFFSHORE TO THE NE. SHUD SEE PLENTY OF SUN EARLY BUT INCREASING
AFTERNOON CLOUDS AHEAD OF A SOUTHERN STREAM SYSTEM AND DEVELOPING
ONSHORE BREEZE WILL HOLD HIGH TEMPS IN THE UPPER 40S TO LOWER 50S
MOST AREAS.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
AS OF 3 PM SUN...SFC HIGH PRES WILL BE RIDGING S INTO THE REGION
WITH RIDGING ALOFT TO START THE LONG TERM BUT CONDITIONS WILL
DETERIORATE MON NIGHT AS A ROBUST UPPER LEVEL CUT-OFF LOW CENTERED
NEAR THE ARKLATEX REGION AT 00Z TUE LIFTS NE TO THE OHIO RIVER
VALLEY THROUGH TUE NIGHT. CLOUDS WILL BE THICKENING AND LOWERING
THROUGH THE EVENING BUT MODELS IN GOOD AGREEMENT WITH PCPN HOLDING
OFF UNTIL AFTER MIDNIGHT...WITH STRONG ISENTROPIC LIFT SPREADING
FROM SOUTH TO NORTH AFTER 09Z. PERIODS OF MODERATE TO HEAVY RAIN
EXPECTED TUESDAY WITH A STRONG 50 KT LOW LEVEL JET TRANSPORTING
ABUNDANT MOISTURE ACROSS THE AREA...PW`S INCREASE TO 1.5"...AND GOOD
DIFLUENCE ALOFT AHEAD OF THE UPPER LOW. WIDESPREAD 1 TO 2" WILL BE
POSSIBLE WITH LOCALLY HIGHER AMOUNTS WHICH MAY BRING MINOR FLOODING
CONCERNS...ESPECIALLY ACROSS URBAN AND LOW LYING AREAS. THE WARM
FRONT WILL LIFT N ACROSS THE AREA TUE AFTERNOON WHICH WILL BRIEFLY
PLACE ERN NC IN THE WARM SECTOR OF THE SYSTEM WHICH MAY BRING JUST
ENOUGH INSTABILITY...MAINLY ELEVATED...TO PRODUCE A FEW
THUNDERSTORMS. WITH ABUNDANT SHEAR IN PLACE ANY THUNDERSTORMS THAT
DEVELOP COULD HAVE THE POTENTIAL TO PRODUCE DAMAGING WIND GUSTS AND
SPC HAS THE REGION IN A 5% PROBABILITY OF SEVERE. SHOWERS END TUE
EVENING WITH LOW PRES LIFTING NORTH AND ASSOCIATED COLD FRONT MOVING
ACROSS ERN NC.
THE CUT-OFF LOW WILL REMAIN QUASI-STATIONARY ACROSS THE NRN
MID-ATLANTIC STATES AND NEW ENGLAND THROUGH THE REST OF THE LONG
TERM. A MID LEVEL VORT MAX MOVES ACROSS THE AREA WED WHICH MAY BRING
AN ISOLATED SHOWER IF SUFFICIENT LOW LEVEL MOISTURE REMAINS...WHICH
WILL MAINLY BE NORTH OF HIGHWAY 70. TEMPS WILL BE SEASONABLE WITH
WRLY FLOW BRINGING HIGHS M50S TO AROUND 60 MOST AREAS. UPPER PATTERN
WILL BECOME HIGHLY AMPLIFIED ACROSS THE EASTERN CONUS BY THE WEEKEND
AS A ROBUST SHORTWAVE PIVOTS THROUGH THE FLOW ALOFT. A SERIES OF
MAINLY DRY COLD FRONTAL PASSAGES WILL MOVE THROUGH GIVEN THE
APPARENT LACK OF DEEP MOISTURE SOURCES IN THE OVERALL WESTERLY FLOW.
TEMPS WILL SHOW A GRADUAL COOLDOWN THROUGH THE END OF THE WEEK AND
WEEKEND WITH CAA BRINGING HEIGHT FALLS HIGHS IN THE MID 50S THU WILL
COOL DOWN 2-3 DEGREES EACH DAY WITH HIGHS SUNDAY EXPECTED IN THE MID
40S WITH H85 TEMPS COOLING TO AROUND -8C. LOWS LIKELY AT OR BLO
FREEZING INLAND THU NIGHT THROUGH SUN NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH MONDAY AFTERNOON/
AS OF 100 AM SUNDAY...PATCHES OF LOCALLY DENSE FOG WILL OCCUR AT
THE SOUTHERN TAF SITES THROUGH 08Z THEN A WEAK BOUNDARY MOVING
SOUTHWARD ACROSS THE AREA WILL CAUSE THE WINDS TO INCREASE OUT OF
THE NORTH AND NORTHEAST AND DISSIPATE THE FOG. THEREAFTER
EXPECTING VFR CONDITIONS FOR THE REMAINDER OF THE TAF PERIOD AS
HIGH PRESSURE BUILDS IN WITH HIGH CLOUDS THICKENING AND LOWERING
THIS AFTERNOON.
LONG TERM /MON NIGHT THROUGH THURSDAY/...
AS OF 3 PM SUN...VFR CONDITIONS TO START MON NIGHT BUT CONDITIONS
DETERIORATE AFTER MIDNIGHT AS A ROBUST LOW PRES SYSTEM LIFT NW OF
THE AREA. SUB-VFR CONDITIONS LIKELY LATE MON NIGHT INTO TUE
EVENING...WITH IFR POSSIBLE TUE WITH HEAVIEST RAIN. ISOLATED TSTMS
WILL BE POSSIBLE TUE AFTERNOON AND EVENING. COULD SEE S/SE WIND
GUSTS AROUND 20-30 KT TUE AFTERNOON WITH STRONGER GUSTS IN TSTMS IF
THEY DEVELOP. PRED VFR CONDITIONS WILL RETURN WED THROUGH FRI.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 100 AM MONDAY...LATEST RAP MODEL INDICATES A SURGE WILL WORK
ITS WAY DOWN THE COAST THROUGH THE OVERNIGHT HOURS. AS A RESULT...LIGHT
SW/W WILL BECOME NORTH AND INCREASE TO 15 TO 20 KNOTS WITH A GUSTS
TO 25 KTS AS HIGH PRESSURE OVER THE GREAT LAKES MOVES SOUTHEAST
AND THE CAA SURGE WORKS DOWN THE COAST. WINDS GRADUALLY VEER NE
AND DECREASE AS THE PRES GRADIENT EASES MON AFTERNOON. SEAS BUILD
TO 5-7 FT LATE TONIGHT IN THE MODERATE NORTH FLOW THEN SLOWLY
SUBSIDE MONDAY AFTN AS WINDS BEGIN TO VEER AND DECREASE. MAIN
CHANGE TO THE FORECAST WAS TO EXTEND THE ADVISORY SOUTH DOWN TO
CAPE LOOKOUT.
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SUN...UNSETTLED CONDITIONS EXPECTED THROUGH THE PERIOD.
CONDITIONS WILL QUICKLY DETERIORATE MON NIGHT INTO EARLY TUE MORNING
AS WARM FRONT AND AN AREA OF LOW PRESSURE LIFT INTO THE
AREA...FLOWING BECOMING SE AND INCREASING TO 15-25KT TUE WITH SEAS
BUILDING TO 7-12FT BY TUE EVENING. WINDS EXPECTED TO PEAK TUE
AFTERNOON AND EVENING WITH A PERIOD OF GALE FORCE CONDITIONS
POSSIBLE. A BRIEF PERIOD OF HIGH SURF CONDITIONS WILL ALSO BE
POSSIBLE GIVEN STRONG ONSHORE FLOW AND BREAKING WAVES 7-10FT. TUE
NIGHT THE SFC LOW WILL LIFT INTO THE MID-ATLANTIC WITH THE ATTENDANT
COLD FRONT MOVING THROUGH THE WATERS. GRADIENT WILL REMAIN TIGHTENED
THROUGH FRI WITH SW/W WINDS 15-25KT AND SEAS REMAINING AROUND 4-7 FT
THROUGH THU...THEN SUBSIDE TO BLO 6 FT FRI.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ135-
150-156.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC/JME
SHORT TERM...BTC
LONG TERM...SK
AVIATION...JME/SK
MARINE...CTC/BTC/JME/SK
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
848 PM CST TUE FEB 26 2013
.DISCUSSION...
LATE AFTERNOON AND EARLY EVENING SAW LOW CLOUDS HANG ON IN A STRIP
FROM CROOKSTON TO FARGO TO GWINNER AND FERGUS FALLS AND ELBOW
LAKE. FOG QUICKLY RE-FORMED IN THIS AREA AND BY 02Z MANY SITES HAD
DROPPED TO 1/4SM IN VSBY WITH FOG SPREADING TO HALLOCK AS WELL AND
WEST INTO PARTS OF GRAND FORKS COUNTY. LATEST RAP MODEL AND OTHER
SHORT RANGE MODELS INDICATE SFC-925 MB WINDS PICKING UP FROM THE
NORTH LATE TONIGHT INTO WEDNESDAY SO THIS MAY HELP BREAK UP THE
FOG A BIT EARLIER THAN OTHERWISE WOULD OCCUR. BUT AS USUAL WITH
FOG THAT TIMING IS HIGHLY SUSPECT. ANOTHER PROBLEM TONIGHT IS THAT
WIDESPREAD HIGH CLOUDS OVER THE AREA DUE TO THE LARGE STORM SYSTEM
OVER THE CHICAGO AREA IS MASKING THE LOW CLOUDS BENEATH MAKING IT
QUITE HARD TO SEE COVERAGE AND LOCATION OF LOW CLOUDS. TEMPS VARY
AS WELL WITH FEW SITES DOWN TO 10F WHILE OTHER SITES NR 20.
AVERAGE LOWS TONIGHT 10-15.
&&
.AVIATION...
TAF FORECASTS ARE VERY DIFFICULT TONIGHT INTO WEDNESDAY MORNING
DUE TO THE PATCHY NATURE OF THE 1/4SM VSBY AND DUE TO HIGH CLOUDS
MASKING THE LOW CLOUDS UNDERNEATH. GFK-FAR ESP VERY DIFFICULT AS
1/4SM VSBYS QUITE LIKELY BUT LENGTH OF TIME AT 1/4SM IS UNKNOWN
AND VSBY COULD VARY GREATLY. OBS AT TVF IS NOT GETTING INTO THE
COMMS SYSTEM THUS NO SKED AMENDMENTS FOR THAT SITE UNTIL COMMS
PROBLEM RESOLVED. TICKET OPENED UP WITH FAA. BJI MAY SEE
RADIATIONAL FOG LATER TONIGHT WHILE DVL REGION APPEARS LEAST PRONE
TO FOG FORMATION AS IN PAST NIGHTS.
.PREV DISCUSSION... /ISSUED 246 PM CST TUE FEB 26 2013/
SHORT TERM...
FOG/STRATUS AND TEMPS REMAIN THE MAIN FORECAST CHALLENGES. HARD
TO FIND A MODEL THAT HAS BEEN DEALING WELL WITH THE CURRENT
CONDITIONS SO WILL HAVE TO RELY MORE ON TRENDS IN THE IMMEDIATE
SHORT TERM.
TONIGHT...THE WORST OF THE STRATUS AND FOG SEEM CONFINED TO THE
IMMEDIATE RED RIVER VALLEY AND SOUTHEAST ND. IN THIS AREA TEMPS
TODAY HAVE BEEN QUITE A BIT LOWER THAN SURROUNDING AREAS TO THE
EAST AND WEST. LIKE THE PAST COUPLE OF DAYS THERE IS VERY LITTLE
LOW LEVEL FLOW TO HELP SCOUR THIS OUT. THEREFORE WHERE THE
STRATUS AND FOG ARE NOW MAY BE WHERE IT REMAINS FOR THE REST OF
THE NIGHT. NOT AS SURE ABOUT DENSE FOG AGAIN SO WILL HAVE TO LET
THE EVENING SHIFT MONITOR THAT ONCE AGAIN. AREAS WITH FOG AND LOW
CLOUDS WILL STAY WARMER AS USUAL.
WED-FRI...AMERICAN MODELS CONTINUE TO SHOW BETTER CHANCES FOR ANY
LIGHT SNOW OR FLURRIES ON WED/THU THAN THE ECMWF. VERY WEAK
FORCING SO WILL MATCH UP WITH NEIGHBORS AND GO WITH FLURRIES
RATHER THAN LIGHT SNOW. TEMPS CONTINUE TO LOOK MILD ALTHOUGH THE
RED RIVER VALLEY HAS TRENDED COOLER THAN PAST FEW DAYS. WILL NEED
BETTER MIXING WITH WEST OR SW WINDS TO PUSH THE WARMER TEMPS DOWN
INTO THE VALLEY AND REALLY DO NOT SEE THIS IN THE SHORT TERM. HARD
TO FORECAST FOG TOO FAR OUT BUT IT SEEMS WE ARE GETTING BACK TO
THE SPRING SNOWMELT SCENARIO WHERE MODELS FORECAST SUNNY DAYS BUT
FOG/STRATUS HANG AROUND ALL DAY.
LONG TERM (FRI NIGHT-TUE)...
THROUGH THE WEEKEND MID LEVEL RIDGE OVER ROCKIES WILL SHIFT SLOWLY
EAST. RIDGE AXIS REMAINS TO OUR WEST HOWEVER WEATHER TO BE QUIET
WITH TEMPERATURES AT OR A LITTLE ABOVE AVERAGE. SURFACE LOW DROPPING
INTO CENTRAL PLAINS EARLY NEXT WEEK WILL BRING FAVORED SNOW CHANCES
TO WESTERN AND SOUTHERN PORTIONS OF THE REGION.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 8 AM CST WEDNESDAY FOR NDZ008-016-027-
030-039-049-052-053.
MN...DENSE FOG ADVISORY UNTIL 8 AM CST WEDNESDAY FOR MNZ001>004-007-
027-029-030-040.
&&
$$
RIDDLE/GODON
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1255 PM EST MON FEB 25 2013
.SYNOPSIS...
NORTH OF A DEVELOPING WARM FRONT...MOISTURE WILL SPREAD ATOP OUR
REGION FROM THE GULF OF MEXICO. STRONG LOW PRESSURE WILL DRIVE
A COLD FRONT ACROSS OUR AREA ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...HIGH TEMPS HAVE BEEN LOWERED A FEW DEGREES. CAD
WEDGE AND THICK CIRRUS DECK HAVE KEPT TEMPS COOLER THAN PREV FCST SO
FAR TODAY. LATEST AVBL MOS GUIDANCE AS WELL AS RAW MODEL TEMPS KEPT
PRACTICALLY ALL OF THE CWA IN THE 40S THROUGH THE DAY. FEEL THIS IS
APPROPRIATE. AS FOR PRECIP...LATEST RAP INDICATES A WAVE OF PRECIP
EARLY THIS AFTN THEN A LULL BEFORE WARM FRONTAL PRECIP TONIGHT.
DISCOUNTING THIS AS MODEL CONSENSUS IS FOR STEADILY INCREASING LLVL
ISENTROPIC FORCING FROM AFTN INTO EVENING...THUS OUR STEADILY
INCREASING POPS LOOK GOOD.
PREVIOUS DISCUSSION...
A WELL DEFINED ULVL CONFLUENT ZONE HAS SET UP ACROSS THE NE CONUS
WHICH IS ALLOWING A 1025 MB OH VALLEY SFC HIGH TO RIDGE EAST AND
SOUTH INTO THE REGION. MEANWHILE...AN H5 S/W IS CROSSING TO THE
SOUTH AND BRINGING IN A WIDE AREA OF CI. THIS SCENARIO IS CAPTURED
WELL BY THE OP MODELS ALONG WITH A DEEPENING H5 CUTOFF LOW PROGGED
TO MOVE INTO THE SRN MS RIVER VALLEY THROUGH THE PERIOD.
A FAIRLY STRONG WEDGE WILL DEVELOP TODAY WHILE MOISTURE FLUX OFF
BOTH THE GOM AND THE ATL ADVECT INTO THE AREA. CROSS SECTIONS ARE
PRETTY CONSISTENT ON THE GFS/NAM/SREF WITH THE DEEPER MOISTURE AND
ISENT OMEGA REACHING THE SRN ZONES AROUND 00Z AND SPREADING PRECIP
OVER THE ENTIRE CWFA QUICKLY THROUGH 03Z. POPS WERE ADJ DOWN EARLY
FOR A SOMEWHAT LATER ONSET TIME...BUT ALL AREAS SHOULD BE AT OR NEAR
100 POP BY 06Z THROUGH THE PERIOD.
THERE IS NOT A LOT OF COOLING NOR LOW TD/S ASSOCIATED WITH THIS
WEDGE...SO PRECIP TYPES OVERNIGHT WILL REMAIN RAIN AT ALL
LOCALES...EXCEPT FOR THE HIGHER TERRAIN OF THE BLACK MTNS AND THE
NRN MTNS WHERE PERIODS -FZRA WILL DEVELOP IN DIURNAL COOLING. MOST
OF THESE LOCATIONS WONT SEE SIGFNT ICE ACCUMS...BUT ISOLATED PEAKS
AROUND BEECH MTN COULD SEE A COUPLE TENTHS OF ICE AS THEY WILL
EXPERIENCE THE LONGEST PERIOD OF ICING BEFORE LLVL WAA CHANGES ALL
PRECIP TO RAIN. RAINFALL AMOUNTS OVERNIGHT WILL BE FAIRLY UNIFORM
ACROSS THE NC ZONES...AROUND AN INCH...AND UP TO AN INCH AND A HALF
ACROSS THE SRN ZONES AND NE GA. THIS WONT CREATE ANY FLOODING
CONCERN DUE TO THE 12 HR TIMEFRAME...BUT ADDITIONAL RAINFALL THROUGH
TUE MAY BEGIN TO ELEVATE SMALL STREAM AND CREEK LEVELS.
ANOTHER ISSUE WITH THIS SYSTEM WILL BE THE HIGHLY DYNAMIC OCCLUDED
SFC LOW TO THE WEST AND THE STRENGTHENING SFC RIDGE EAST. THIS WILL
SET UP A RATHER STRONG P/GRAD...BUT THE SFC WINDS WONT BECOME OVERLY
GUSTY WITH THE STRONGER VELOCITIES REMAINING ABOVE THE WEDGE
INVERSION. THE HIGHER ELEVATIONS OF THE WRN NC MTNS WILL LIKELY SEE
A SE/LY MTN WAVE SET UP AND DAMAGING WIND GUSTS FORCED TO THE SFC.
THE MODELS ARE SHOWING VERY GOOD ISENT DECENT AND RELATIVELY DEEP
NEG OMEGA AFT 06Z ALIGNED WITH WIND SPEEDS OF 55 KTS ABOVE 3.5 K
FEET. BASED ON GOOD CONFIDENCE WITH THIS IMPENDING SCENARIO...A HIGH
WIND WARNING WILL BE ISSUED FOR THE WRN NC MTNS ABOVE 3.5 K.
MAX TEMPS TODAY WILL BE ON THE COOL SIDE WITH WEDGE AND CLOUD COVER.
BLENDED THE OFFICIAL FCST WITH LOWER END METMOS GUIDANCE...WHICH
GAVE MAXES IN THE L50S NON/MTNS...AND U40S MTN VALLEYS. CONTINUED
NE/LY FLOW AND COOLER AIR ALOFT GUSTING TO THE SFC...YET HIGH CLOUD
COVER...LOWS SHOULD DROP TO RIGHT AROUND NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EST MONDAY...THE SHORT RANGE WILL BE DOMINATED BY THE
PASSAGE OF A LARGE AND DYNAMIC UPPER LOW MOVING FROM THE MID MS
VALLEY...UP THE OH VALLEY...TO THE LOWER GREAT LAKES THROUGH THE
PERIOD. THE MAIN ACTION WILL BE TUESDAY...WITH A CLASSIC COLD AIR
DAMMING WEDGE IN PLACE AT SUNRISE WITH PRECIP FALLING ACROSS NEARLY
THE ENTIRE FCST AREA. THERE ARE MANY CONCERNS. HIGH WIND POTENTIAL
WILL REMAIN HIGH ALONG THE TN BORDER SO THE HIGH WIND WARNING WILL
BE RUN THROUGH NOON. ANY LINGERING PRECIP TYPE ISSUES NEAR THE BLUE
RIDGE OVER THE NRN MTNS AND NRN FOOTHILLS SHOULD GO AWAY QUICKLY
AFTER SUNRISE WITH TEMPS WARMING ABOVE FREEZING. HEAVY RAIN IS ONE
OF THE PRIMARY CONCERNS...AND THE OTHER IS SEVERE WEATHER. MUCH OF
THIS WILL DEPEND ON THE TRACK OF A TRIPLE POINT LOW. THE LATEST
MODEL GUIDANCE SHOWS THIS FEATURE MOVING ACROSS THE MIDDLE OF SC AND
NC...OFF TO OUR EAST...DURING THE DAY. THIS WOULD TEND TO DECREASE
THE HEAVY RAIN THREAT OVER THE MTNS AND BLUE RIDGE ALONG THE SC/NC
BORDER. PW ANOMALIES ARE NOT OVERLY HIGH EITHER. WILL NOT ISSUE A
FLOOD WATCH AT THIS TIME OWING TO THE DOWNWARD QPF TREND. AS FOR THE
SEVERE WEATHER...IF THE TRIPLE POINT LOW TAKES A MORE WESTWARD TRACK
AS SHOWN BY THE NAM...WE COULD GET THE SRN/ERN PARTS OF METRO CLT
INTO THE WARMER AIR ON THE COASTAL SIDE OF THE WEDGE BOUNDARY IN THE
LATE AFTERNOON...WHICH WOULD INCREASE THE THREAT FOR SEVERE STORMS.
FOR NOW...WILL INCLUDE SOME THUNDER IN THE FCST THERE.
THE PRECIP SHOULD EXIT THE REGION DURING THE LATE AFTERNOON AND
EARLY EVENING ON TUESDAY...AFTER WHICH ANY LINGERING POP IS
RELEGATED TO THE MTNS...MOSTLY NEAR THE TN BORDER. THE MAIN CULPRIT
WILL BE WRAP-AROUND SHOWERS THROUGH TUESDAY NIGHT AND INTO
WEDNESDAY. THE LOW LEVEL FLOW REMAINS SW INITIALLY AND IS ONLY
SLOWLY EXPECTED TO COME AROUND TO W AND THEN NW WEDNESDAY NIGHT.
THUS...PRECIP POTENTIAL WILL GRADUALLY IMPROVE WEDNESDAY NIGHT AS
COLDER AIR MOVES IN TO CHANGE THE P-TYPE TO SNOW TOWARD DAYBREAK ON
THURSDAY. SOME ACCUM SHOULD BE EXPECTED ON THE TN BORDER...AND THIS
IS EXPECTED TO CONTINUE INTO THE MEDIUM RANGE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 230 AM MONDAY...A DEEPENING LOW PRES SYSTEM WILL CONSOLIDATE
OVER WRN PA/NY EARLY THU. THERE IS GOOD MODEL CONSENSUS ON THE
LOCATION AND DEPTH OF THIS MAJOR FEATURE EARLY ON...BUT THEN VARYING
SOLUTIONS ON ADDITIONAL ENERGY PIVOTING AROUND THE LOW AND CROSSING
THE REGION FRI THROUGH SUN.
AS THE LOW SLOWLY DEPARTS PA AND NY AREA TO THE EAST THURS THROUGH
FRI...LOW LEVEL MOISTURE WILL BE IN PLACE OVER EAST TN UP AGAINST
THE NC MTNS. THIS MOISTURE WILL BE DEEPEST IN THIS MEDIUM RANGE
PERIOD ON THURS AND GRADUALLY DECREASE DEPENDING ON THE MODEL
REFERENCED INTO THE WEEKEND. 850MB TEMPS OVER THE MTNS WILL RANGE
FROM -5 TO -7C AT 12Z THURS BEING SLIGHTLY COLDEST IN THE ECMWF.
THESE 850MB TEMPS WARM A DEGREE OR TWO INTO FRI AND THEN COLDER
THROUGH THE WEEKEND DOWN TO -8 TO -11C 12Z SUNDAY. ALONG WITH THE
DEEPEST MOISTURE ON THURSDAY...THE WIND IS FORECAST TO BE FROM THE
WNW. AS THE LOW MOVES EAST ALONG WITH MORE SHALLOW MOISTURE...THE
WIND BECOMES NW WHICH IS MOST FAVORABLE FOR UPSLOPE SNOW SHOWERS.
SOME SHORTWAVE ENERGY ROUNDS THE BASE OF THE TROUGH LATE FRIDAY
ENHANCING THE UPSLOPE SNSH. ANOTHER SPOKE OF ENERGY CROSSES SAT PM
AND THE ECMWF CONTINUES TO HAVE A CUT OFF LOW WHICH KICKS OFF LIGHT
PRECIP OVER ALL OF THE WESTERN CAROLINAS AND NORTH GA SAT PM. THE
GFS HAS SOME PRECIP OVER NRN GA AND UPSTATE AND THE CMC LAYS OUT A
BROADER TROUGH AND SMALLER AMOUNTS OF SPOTTY PRECIP. THE UPPER
TROUGH AXIS IF FORECAST TO CROSS OUR AREA LATE SUNDAY. EXPECT MINS 5
TO 10 DEGREES BELOW NORMAL...WITH MAXES 10 TO 15 DEGREES BELOW
NORMAL...THROUGH THE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AT KCLT...CIRRUS CIG THIS AFTN WILL BEGIN TO LOWER BY LATE AFTN AS
ISENTROPIC LIFT OVER COLD SFC WEDGE RAMPS UP. LOW VFR LOOKS TO SET
IN BY ABOUT 01Z FOLLOWED BY RAPID LOWERING TO IFR CIG WITH ONSET OF
RAINFALL THAT WILL CONTINUE THROUGH THE END OF THE PERIOD. GUIDANCE
SUGGESTS MVFR VSBY WILL ACCOMPANY THE RAIN BUT FOG NOT EXPECTED WITH
NEAR SFC AIR REMAINING DRY. WINDS REMAIN NE TO ENE UNDER THE WEDGE
GRADUALLY INCREASING IN STRENGTH AS SFC LOW ENTERS OHIO VALLEY.
APPROACHING COLD FRONT WILL LIKELY SCOUR OUT THE WEDGE...TURN WINDS
SWLY AND END THE PRECIP...BUT CURRENT TIMING HAS THIS OCCURRING
AFTER 18Z.
ELSEWHERE...VFR CIGS THIS AFTN WILL LOWER FROM SOUTH TO NORTH AS
WARM FRONT/ISENTROPIC LIFT INCREASES AHEAD OF APPROACHING SFC LOW.
FAR SOUTHERN PART OF THE FCST AREA EXPECTED TO SEE MVFR CIG BY
AROUND SUNSET WHEN PRECIP SHOULD ALSO BEGIN. PRECIP WILL SPREAD
NORTHWARD ACROSS ALL SITES OVERNIGHT PEAKING IN COVERAGE AROUND
SUNRISE. RAIN WILL LIKELY LOWER VSBY TO MVFR...AND THOUGH SFC TEMPS
MAY REMAIN JUST ABOVE FREEZING IN THE MTNS SOME SNOW/SLEET MAY MIX
WITH THE RAIN THERE LATE TONIGHT. GUIDANCE GIVING FAIRLY STRONG
SIGNAL OF WIDESPREAD IFR CIGS ACROSS THE AREA FORMING AROUND 09Z.
THIS IS LIKELY TO LAST UNTIL COLD FRONT WORKS INTO THE REGION FROM
THE WEST NEAR THE END OF THE PERIOD. KAVL MAY SEE LIFTING TO VFR
JUST BEFORE 18Z. WINDS WILL REMAIN IN NE QUADRANT AT ALL SITES UNTIL
THE FRONT MOVES THROUGH...AGAIN THE ONLY SITE AFFECTED IS KAVL.
OUTLOOK...CLEARING SKIES ARE IN STORE TUESDAY NIGHT WITH VFR
EXPECTED THROUGH THURSDAY EAST OF THE MOUNTAINS. SOME POTENTIAL FOR
MVFR ACROSS THE NC MTNS WITH SNOW SHOWERS MID TO LATE WEEK.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% MED 72% HIGH 93%
KGSP HIGH 100% HIGH 81% MED 62% HIGH 89%
KAVL HIGH 100% HIGH 87% HIGH 83% HIGH 80%
KHKY HIGH 100% HIGH 100% MED 75% HIGH 89%
KGMU HIGH 100% MED 79% MED 62% HIGH 89%
KAND HIGH 100% MED 75% MED 77% HIGH 93%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST TUESDAY
FOR NCZ033-048>052-058-059.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EST TUESDAY FOR
NCZ033-048>052-058-059.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...SBK/WIMBERLEY
SHORT TERM...PM
LONG TERM...DEO
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
944 AM EST MON FEB 25 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE GREAT LAKES TODAY AS MOISTURE
SPREADS OVER OUR REGION FROM THE GULF OF MEXICO AHEAD OF A WARM
FRONT. STRONG LOW PRESSURE WILL MOVE FROM NORTHEAST TEXAS TODAY TO
WESTERN KENTUCKY LATE TUESDAY. A COLD FRONT WILL CROSS OUR AREA
WEDNESDAY EVENING.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...HIGH TEMPS HAVE BEEN LOWERED A FEW DEGREES. CAD
WEDGE AND THICK CIRRUS DECK HAVE KEPT TEMPS COOLER THAN PREV FCST SO
FAR TODAY. LATEST AVBL MOS GUIDANCE AS WELL AS RAW MODEL TEMPS KEPT
PRACTICALLY ALL OF THE CWA IN THE 40S THROUGH THE DAY. FEEL THIS IS
APPROPRIATE. AS FOR PRECIP...LATEST RAP INDICATES A WAVE OF PRECIP
EARLY THIS AFTN THEN A LULL BEFORE WARM FRONTAL PRECIP TONIGHT.
DISCOUNTING THIS AS MODEL CONSENSUS IS FOR STEADILY INCREASING LLVL
ISENTROPIC FORCING FROM AFTN INTO EVENING...THUS OUR STEADILY
INCREASING POPS LOOK GOOD.
PREVIOUS DISCUSSION...
A WELL DEFINED ULVL CONFLUENT ZONE HAS SET UP ACROSS THE NE CONUS
WHICH IS ALLOWING A 1025 MB OH VALLEY SFC HIGH TO RIDGE EAST AND
SOUTH INTO THE REGION. MEANWHILE...AN H5 S/W IS CROSSING TO THE
SOUTH AND BRINGING IN A WIDE AREA OF CI. THIS SCENARIO IS CAPTURED
WELL BY THE OP MODELS ALONG WITH A DEEPENING H5 CUTOFF LOW PROGGED
TO MOVE INTO THE SRN MS RIVER VALLEY THROUGH THE PERIOD.
A FAIRLY STRONG WEDGE WILL DEVELOP TODAY WHILE MOISTURE FLUX OFF
BOTH THE GOM AND THE ATL ADVECT INTO THE AREA. CROSS SECTIONS ARE
PRETTY CONSISTENT ON THE GFS/NAM/SREF WITH THE DEEPER MOISTURE AND
ISENT OMEGA REACHING THE SRN ZONES AROUND 00Z AND SPREADING PRECIP
OVER THE ENTIRE CWFA QUICKLY THROUGH 03Z. POPS WERE ADJ DOWN EARLY
FOR A SOMEWHAT LATER ONSET TIME...BUT ALL AREAS SHOULD BE AT OR NEAR
100 POP BY 06Z THROUGH THE PERIOD.
THERE IS NOT A LOT OF COOLING NOR LOW TD/S ASSOCIATED WITH THIS
WEDGE...SO PRECIP TYPES OVERNIGHT WILL REMAIN RAIN AT ALL
LOCALES...EXCEPT FOR THE HIGHER TERRAIN OF THE BLACK MTNS AND THE
NRN MTNS WHERE PERIODS -FZRA WILL DEVELOP IN DIURNAL COOLING. MOST
OF THESE LOCATIONS WONT SEE SIGFNT ICE ACCUMS...BUT ISOLATED PEAKS
AROUND BEECH MTN COULD SEE A COUPLE TENTHS OF ICE AS THEY WILL
EXPERIENCE THE LONGEST PERIOD OF ICING BEFORE LLVL WAA CHANGES ALL
PRECIP TO RAIN. RAINFALL AMOUNTS OVERNIGHT WILL BE FAIRLY UNIFORM
ACROSS THE NC ZONES...AROUND AN INCH...AND UP TO AN INCH AND A HALF
ACROSS THE SRN ZONES AND NE GA. THIS WONT CREATE ANY FLOODING
CONCERN DUE TO THE 12 HR TIMEFRAME...BUT ADDITIONAL RAINFALL THROUGH
TUE MAY BEGIN TO ELEVATE SMALL STREAM AND CREEK LEVELS.
ANOTHER ISSUE WITH THIS SYSTEM WILL BE THE HIGHLY DYNAMIC OCCLUDED
SFC LOW TO THE WEST AND THE STRENGTHENING SFC RIDGE EAST. THIS WILL
SET UP A RATHER STRONG P/GRAD...BUT THE SFC WINDS WONT BECOME OVERLY
GUSTY WITH THE STRONGER VELOCITIES REMAINING ABOVE THE WEDGE
INVERSION. THE HIGHER ELEVATIONS OF THE WRN NC MTNS WILL LIKELY SEE
A SE/LY MTN WAVE SET UP AND DAMAGING WIND GUSTS FORCED TO THE SFC.
THE MODELS ARE SHOWING VERY GOOD ISENT DECENT AND RELATIVELY DEEP
NEG OMEGA AFT 06Z ALIGNED WITH WIND SPEEDS OF 55 KTS ABOVE 3.5 K
FEET. BASED ON GOOD CONFIDENCE WITH THIS IMPENDING SCENARIO...A HIGH
WIND WARNING WILL BE ISSUED FOR THE WRN NC MTNS ABOVE 3.5 K.
MAX TEMPS TODAY WILL BE ON THE COOL SIDE WITH WEDGE AND CLOUD COVER.
BLENDED THE OFFICIAL FCST WITH LOWER END METMOS GUIDANCE...WHICH
GAVE MAXES IN THE L50S NON/MTNS...AND U40S MTN VALLEYS. CONTINUED
NE/LY FLOW AND COOLER AIR ALOFT GUSTING TO THE SFC...YET HIGH CLOUD
COVER...LOWS SHOULD DROP TO RIGHT AROUND NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EST MONDAY...THE SHORT RANGE WILL BE DOMINATED BY THE
PASSAGE OF A LARGE AND DYNAMIC UPPER LOW MOVING FROM THE MID MS
VALLEY...UP THE OH VALLEY...TO THE LOWER GREAT LAKES THROUGH THE
PERIOD. THE MAIN ACTION WILL BE TUESDAY...WITH A CLASSIC COLD AIR
DAMMING WEDGE IN PLACE AT SUNRISE WITH PRECIP FALLING ACROSS NEARLY
THE ENTIRE FCST AREA. THERE ARE MANY CONCERNS. HIGH WIND POTENTIAL
WILL REMAIN HIGH ALONG THE TN BORDER SO THE HIGH WIND WARNING WILL
BE RUN THROUGH NOON. ANY LINGERING PRECIP TYPE ISSUES NEAR THE BLUE
RIDGE OVER THE NRN MTNS AND NRN FOOTHILLS SHOULD GO AWAY QUICKLY
AFTER SUNRISE WITH TEMPS WARMING ABOVE FREEZING. HEAVY RAIN IS ONE
OF THE PRIMARY CONCERNS...AND THE OTHER IS SEVERE WEATHER. MUCH OF
THIS WILL DEPEND ON THE TRACK OF A TRIPLE POINT LOW. THE LATEST
MODEL GUIDANCE SHOWS THIS FEATURE MOVING ACROSS THE MIDDLE OF SC AND
NC...OFF TO OUR EAST...DURING THE DAY. THIS WOULD TEND TO DECREASE
THE HEAVY RAIN THREAT OVER THE MTNS AND BLUE RIDGE ALONG THE SC/NC
BORDER. PW ANOMALIES ARE NOT OVERLY HIGH EITHER. WILL NOT ISSUE A
FLOOD WATCH AT THIS TIME OWING TO THE DOWNWARD QPF TREND. AS FOR THE
SEVERE WEATHER...IF THE TRIPLE POINT LOW TAKES A MORE WESTWARD TRACK
AS SHOWN BY THE NAM...WE COULD GET THE SRN/ERN PARTS OF METRO CLT
INTO THE WARMER AIR ON THE COASTAL SIDE OF THE WEDGE BOUNDARY IN THE
LATE AFTERNOON...WHICH WOULD INCREASE THE THREAT FOR SEVERE STORMS.
FOR NOW...WILL INCLUDE SOME THUNDER IN THE FCST THERE.
THE PRECIP SHOULD EXIT THE REGION DURING THE LATE AFTERNOON AND
EARLY EVENING ON TUESDAY...AFTER WHICH ANY LINGERING POP IS
RELEGATED TO THE MTNS...MOSTLY NEAR THE TN BORDER. THE MAIN CULPRIT
WILL BE WRAP-AROUND SHOWERS THROUGH TUESDAY NIGHT AND INTO
WEDNESDAY. THE LOW LEVEL FLOW REMAINS SW INITIALLY AND IS ONLY
SLOWLY EXPECTED TO COME AROUND TO W AND THEN NW WEDNESDAY NIGHT.
THUS...PRECIP POTENTIAL WILL GRADUALLY IMPROVE WEDNESDAY NIGHT AS
COLDER AIR MOVES IN TO CHANGE THE P-TYPE TO SNOW TOWARD DAYBREAK ON
THURSDAY. SOME ACCUM SHOULD BE EXPECTED ON THE TN BORDER...AND THIS
IS EXPECTED TO CONTINUE INTO THE MEDIUM RANGE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 230 AM MONDAY...A DEEPENING LOW PRES SYSTEM WILL CONSOLIDATE
OVER WRN PA/NY EARLY THU. THERE IS GOOD MODEL CONSENSUS ON THE
LOCATION AND DEPTH OF THIS MAJOR FEATURE EARLY ON...BUT THEN VARYING
SOLUTIONS ON ADDITIONAL ENERGY PIVOTING AROUND THE LOW AND CROSSING
THE REGION FRI THROUGH SUN.
AS THE LOW SLOWLY DEPARTS PA AND NY AREA TO THE EAST THURS THROUGH
FRI...LOW LEVEL MOISTURE WILL BE IN PLACE OVER EAST TN UP AGAINST
THE NC MTNS. THIS MOISTURE WILL BE DEEPEST IN THIS MEDIUM RANGE
PERIOD ON THURS AND GRADUALLY DECREASE DEPENDING ON THE MODEL
REFERENCED INTO THE WEEKEND. 850MB TEMPS OVER THE MTNS WILL RANGE
FROM -5 TO -7C AT 12Z THURS BEING SLIGHTLY COLDEST IN THE ECMWF.
THESE 850MB TEMPS WARM A DEGREE OR TWO INTO FRI AND THEN COLDER
THROUGH THE WEEKEND DOWN TO -8 TO -11C 12Z SUNDAY. ALONG WITH THE
DEEPEST MOISTURE ON THURSDAY...THE WIND IS FORECAST TO BE FROM THE
WNW. AS THE LOW MOVES EAST ALONG WITH MORE SHALLOW MOISTURE...THE
WIND BECOMES NW WHICH IS MOST FAVORABLE FOR UPSLOPE SNOW SHOWERS.
SOME SHORTWAVE ENERGY ROUNDS THE BASE OF THE TROUGH LATE FRIDAY
ENHANCING THE UPSLOPE SNSH. ANOTHER SPOKE OF ENERGY CROSSES SAT PM
AND THE ECMWF CONTINUES TO HAVE A CUT OFF LOW WHICH KICKS OFF LIGHT
PRECIP OVER ALL OF THE WESTERN CAROLINAS AND NORTH GA SAT PM. THE
GFS HAS SOME PRECIP OVER NRN GA AND UPSTATE AND THE CMC LAYS OUT A
BROADER TROUGH AND SMALLER AMOUNTS OF SPOTTY PRECIP. THE UPPER
TROUGH AXIS IF FORECAST TO CROSS OUR AREA LATE SUNDAY. EXPECT MINS 5
TO 10 DEGREES BELOW NORMAL...WITH MAXES 10 TO 15 DEGREES BELOW
NORMAL...THROUGH THE PERIOD.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AT KCLT /15Z UPDATE/...LATEST PROG SOUNDINGS SHOW SOME MIXING
OCCURRING IN COLD WEDGE DESPITE MUCH SFC WARMING. SOME LOW END GUSTS
HAVE ALREADY OCCURRED AND MORE COULD OCCUR...BUT WINDS SHOULD
GRADUALLY INCREASE TO A STEADY 10KT OR SO REDUCING GUST FREQUENCY.
UPPER LEVEL CLOUDS WILL LOWER THROUGH THE PERIOD ALONG WITH PERHAPS
A FEW LOW VFR CLOUDS SEEN THIS AFTN. MVFR CIGS EXPECTED AFTER 03Z. A
CONTINUED LOWERING DECK TO IFR BY 10Z WILL BE ACCOMPANIED BY -SHRA.
THE WEDGE WILL STRENGTHEN AS THE PRECIP MOVES IN AND NE/LY WINDS
WILL VEER TO ENE/LY AROUND 00Z AND BECOME MODERATELY GUSTY THROUGH
THE REMAINDER OF THE TAF PERIOD.
ELSEWHERE...WITH A SFC WEDGE STRENGTHENING DURING THE DAY...WINDS
WILL BE MAINTAINED GENERALLY NE/LY AT ALL NON/MTN TAF SITES
BECOMING GUSTY AROUND 00Z. WINDS WILL HAVE LESS GUST
POTENTIAL...BUT STILL SUSTAINED AROUND 10 KTS...AT KAVL AND ALIGNED
SE/LY DOWN THE FRENCH BROAD VALLEY. ALL SITES WILL EXPERIENCE
LOWERING CIGS INTO MVFR ACCOMPANIED BY -SHRA BY 00Z WITH IFR
PROBABLE ACROSS THE UPSTATE AROUND 09Z.
OUTLOOK...CLEARING SKIES ARE IN STORE TUESDAY NIGHT WITH VFR
EXPECTED THROUGH THURSDAY EAST OF THE MOUNTAINS. SOME POTENTIAL FOR
MVFR ACROSS THE NC MTNS WITH SNOW SHOWERS MID TO LATE WEEK.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT HIGH 100% HIGH 100% HIGH 94% HIGH 94%
KGSP HIGH 100% HIGH 100% HIGH 86% HIGH 92%
KAVL HIGH 100% HIGH 100% HIGH 84% HIGH 92%
KHKY HIGH 100% HIGH 100% HIGH 95% HIGH 92%
KGMU HIGH 100% HIGH 100% HIGH 87% HIGH 92%
KAND HIGH 100% HIGH 83% HIGH 91% HIGH 85%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST TUESDAY
FOR NCZ033-048>052-058-059.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EST TUESDAY FOR
NCZ033-048>052-058-059.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...SBK/WIMBERLEY
SHORT TERM...PM
LONG TERM...DEO
AVIATION...SBK/WIMBERLEY
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
350 PM CST MON FEB 25 2013
.DISCUSSION...
POWERFUL WINTER STORM CONTINUES TO MOVE THROUGH THE SOUTHERN
PLAINS THIS AFTERNOON RESULTING IN PRIMARILY A WIND EVENT ACROSS
NORTH TEXAS...BUT SOME WINTRY WEATHER IS EXPECTED THROUGH THIS
EVENING FOR PARTS OF THE AREA. LATEST SURFACE ANALYSIS SHOWS THE
CENTER OF THE SURFACE LOW NEAR EL DORADO ARKANSAS WHERE 3 HOUR
PRESSURE FALLS ARE IN EXCESS OF 7MB. PRESSURE FALLS EXTEND ALL THE
WAY WESTWARD TOWARD WICHITA FALLS WHERE A SURFACE TROUGH HAS
PERSISTED ALL DAY. THESE PERSISTENT PRESSURE FALLS ARE AN
INDICATION THAT THE ENTIRE UPPER STORM SYSTEM IS DEEPENING. WATER
VAPOR IMAGERY SHOWS A WELL DEFINED CIRCULATION WHICH APPEARS TO
NOW BE MOVING DUE EAST TOWARD THE BEST SURFACE PRESSURE FALLS.
THIS IS CONCERNING BECAUSE SUBSTANTIAL WRAP AROUND PRECIPITATION
DRIVEN BY FRONTOGENETICAL FORCING WILL LIKELY TRACK FARTHER SOUTH
THAN EARLIER ANTICIPATED. SHORT TERM HIGH RESOLUTION GUIDANCE
APPEARS TO HAVE SOMEWHAT OF A HANDLE ON THE MOVEMENT OF THE UPPER
SYSTEM BUT PRECIPITATION IS QUICKLY ERODED DUE TO STRONG
SUBSIDENCE. MESOSCALE FRONTOGENETICAL FORCING IS LIKELY TO WIN OUT
AT LEAST FOR A FEW HOURS ON THE BACK SIDE OF THE SYSTEM RESULTING
IN PRECIPITATION ACROSS MAINLY THE NORTHWEST COUNTIES THROUGH MIDNIGHT.
CONCERNING THE PRECIPITATION...FORECAST SOUNDINGS FROM BOTH THE
HIGH RES 3KM TTU WRF AND RAP MODEL SUGGEST THAT THE THERMAL
PROFILE WILL BE SUFFICIENTLY COLD FOR SNOWFALL PRODUCTION
GENERALLY NORTH OF INTERSTATE 20 THROUGH LATE TONIGHT...DESPITE
THE WARM SURFACE TEMPERATURES. INITIAL CONVECTIVE SHOWERS
NORTHEAST OF THE METROPLEX SHOULD REMAIN ALL LIQUID. GIVEN THE
POTENTIAL FOR SNOWFALL...ALONG WITH STRONG GUSTY WINDS...HAVE
ISSUED A SHORT DURATION WINTER WEATHER ADVISORY FOR THE FAR
NORTHWEST COUNTIES THROUGH MIDNIGHT. WITH WARM GROUND TEMPERATURES
AND GENERALLY ABOVE FREEZING SURFACE TEMPERATURES...EXPECT ANY
ACCUMULATIONS TO BE CONFINED TO GRASSY SURFACES. THE PRIMARY
CONCERN WILL BE FOR BLOWING SNOW WHICH COULD REDUCE VISIBILITY TO
LESS THAN 1/2 MILE AT TIMES. ROADS SHOULD REMAIN IN GOOD SHAPE.
THE OTHER MAIN CONCERN IS WINDS THROUGH LATE TONIGHT. WITH THE
CENTER OF THE SURFACE LOW NEARBY FOR MUCH OF THE AFTERNOON...WINDS
HAVE GENERALLY BEEN HIGHEST ACROSS THE SOUTHERN COUNTIES WHERE
GUSTS TO 54 MPH HAVE BEEN REPORTED. WITH THE SURFACE LOW NOW
MOVING EAST...THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN
THROUGH EVENING. THE STRONGEST LOW LEVEL JET WILL BE CENTERED
ACROSS THE AREA RIGHT AROUND MIDNIGHT SO IT APPEARS THAT THE
STRONGEST WINDS ACROSS MUCH OF THE REGION ARE STILL TO COME.
ONE LIMITING FACTOR TO STRONGER WINDS WILL BE THE FACT THAT IT
WILL BE NIGHT WHEN THE STRONGEST WINDS ALOFT ARE OVERHEAD. THE CURRENT
WIND ADVISORY WILL REMAIN IN EFFECT THROUGH 4 AM FOR ALL OF NORTH
TEXAS.
WITH THE ENTIRE SYSTEM MOVING TO THE NORTHEAST TOMORROW...SKIES
SHOULD CLEAR AND WINDS WILL DIMINISH. A COUPLE OF REINFORCING
FRONTS...ONE ON WEDNESDAY AND ANOTHER LATE THURSDAY NIGHT...WILL
KEEP TEMPERATURES COOL THROUGH THE WEEK. NO SIGNIFICANT CHANGES TO
THE EXTENDED FORECAST AS IT APPEARS THAT IT WILL REMAIN DRY
THROUGH THE PERIOD.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 35 54 34 54 34 / 20 5 0 0 5
WACO, TX 35 61 34 60 33 / 5 0 0 0 5
PARIS, TX 36 49 31 51 31 / 40 5 0 0 5
DENTON, TX 35 53 30 51 31 / 30 5 0 0 5
MCKINNEY, TX 36 52 32 51 32 / 30 5 0 0 5
DALLAS, TX 37 56 35 55 35 / 20 5 0 0 5
TERRELL, TX 36 52 34 54 34 / 10 5 0 0 5
CORSICANA, TX 37 57 35 58 34 / 5 0 0 0 5
TEMPLE, TX 36 63 36 63 33 / 5 0 0 0 5
MINERAL WELLS, TX 34 57 30 54 29 / 40 0 0 0 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 AM CST TUESDAY FOR TXZ091>095-100>107-
115>123-129>135-141>148-156>162-174-175.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR TXZ091-
100-101-115.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1157 AM CST MON FEB 25 2013
.AVIATION...
FOR THE 18Z TAFS...AN AVIATION WEATHER WARNING REMAINS IN EFFECT FOR
KAMA AND TRADEWIND AIRPORT THROUGH 00Z TONIGHT DUE TO STRONG GUSTY WINDS.
SNOW...BLOWING SNOW...AND GUSTY WINDS WILL BE THE PRIMARY FOCUS
THROUGH EARLY EVENING. SNOW HAS STOPPED AT KDHT...WITH THE
POSSIBILITY FOR BLOWING SNOW THROUGH 21Z AS WINDS REMAIN GUSTY TO
45KTS. CEILINGS SHOULD CONTINUE TO IMPROVE THROUGH 03Z WHEN SKIES
WILL CLEAR
AT KAMA AND KGUY...SNOW AND BLOWING SNOW CONTINUE TO REDUCE
VISIBILITY BELOW 1 MILE...WITH KAMA VSBY AT 1/4SM TO 1/2SM WHILE SNOW
REMAINS HEAVY. SNOW SHOULD TAPER OFF BY 00Z. IFR CEILINGS SLOWLY
IMPROVING TO MVFR CEILINGS BY 21Z TO 00Z...BEFORE CLEARING AFTER 03Z.
NF
&&
.PREV DISCUSSION... /ISSUED 1057 AM CST MON FEB 25 2013/
UPDATE...
MADE MINOR ADJUSTMENTS TO THE SNOW AMOUNT GRIDS FROM NOON TO 6 PM TO
ACCOUNT FOR HIGHER SNOWFALL RATES AS THE UPPER LOW LIFTS TO THE NORTH
AND EAST. DURING THIS TIME FRAME 3 TO 6 ADDITIONAL INCHES OF SNOW
WILL BE POSSIBLE ACROSS THE EASTERN OKLAHOMA AND TEXAS PANHANDLE AND
THE SOUTH CENTRAL TEXAS PANHANDLE.
PREV DISCUSSION... /ISSUED 833 AM CST MON FEB 25 2013/
.CRIPPLING BLIZZARD ROARS ON...
UPDATE...
GOING FORECAST STILL ON TRACK. THE NWS OFFICE NOW HAS OVER 13 INCHES
ON THE GROUND WITH 3-4 FOOT DRIFTS AND A MAX GUST TO 58 MPH. THE SE
TX PANHANDLE HAS BEEN SLOW TO FILL IN WITH SNOW AFTER THE
THUNDERSTORMS THAT DROPPED HEAVY RAIN LAST NIGHT AND THESE AREAS
MIGHT END UP WITH AMOUNTS CLOSER TO THE 8 INCH SIDE THAN THE 14 INCH
SIDE OF THEIR RANGE. AT THE END OF THE DAY...THE HEAVIEST TOTALS
WILL ALMOST CERTAINLY BE ALONG A PALO DURO CANYON TO AMARILLO TO
STINNETT TO PERRYTON LINE.
SOME RECORDS SEEM TO BE IN A PRECARIOUS POSITION TODAY. THE FIRST IS
AN ALL-TIME 24 HOUR SNOWFALL RECORD AT AMARILLO OF 20.6 INCHES FROM
MARCH 25-26 1934. WE WILL LIKELY GET VERY CLOSE OR SURPASS THIS
NUMBER BY THIS AFTERNOON.
THE OTHER IS THE ALL-TIME STATE OF TEXAS 24 HOUR SNOWFALL RECORD OF
25 INCHES IN FOLLETT SET MARCH 28 2009. SOMEWHERE IN THE
PERRYTON/STINNETT/BORGER/AMARILLO AREA COULD APPROACH THIS VALUE BY
THIS AFTERNOON.
SIMPSON
PREV DISCUSSION... /ISSUED 541 AM CST MON FEB 25 2013/
AVIATION.../12Z TAFS/
VERY HAZARDOUS FLYING CONDITIONS EXPECTED TO CONTINUE THROUGH AT
LEAST 00Z AT ALL TERMINALS. HEAVIEST SNOW AND LOWEST VISIBILITIES
WILL BE AT KAMA 15-20Z. AWW REMAINS IN EFFECT FOR KAMA AND TRADEWINDS
AIRPORT UNTIL 00Z.
VFR CONDITIONS ARE EXPECTED TO RETURN TO ALL TERMINALS 00-02Z.
NW WINDS ARE EXPECTED TO SUBSIDE BELOW 12 KT AT ALL TERMINALS BY 04Z.
JACKSON
PREV DISCUSSION... /ISSUED 446 AM CST MON FEB 25 2013/
SNOW PILING UP...WINDS INCREASING AND CREATING FULL FLEDGED BLIZZARD
CONDITIONS AT THIS WRITING...
DISCUSSION...
MAIN CHANGE TO PREVIOUS FORECAST WAS TO ATTEMPT TO PIN POINT THE BAND
OF HIGHEST SNOW TOTALS...WHICH WILL LIKELY STRETCH ALONG AN ARC FROM
TULIA TO AMARILLO TO STINNETT TO SPEARMAN. LOCATIONS ON THIS ARC AND
30 MILES TO THE EAST AND WEST OF IT ARE SET TO RECEIVE AT LEAST A
FOOT OF SNOW...WITH TOTALS UP TO 2 FEET NOT COMPLETELY OUT OF THE
QUESTION. THE REST OF THE PANHANDLES WILL SEE SLIGHTLY LESSER
AMOUNTS...BUT STILL BLIZZARD CONDITIONS. SEE THE BLIZZARD WARNING AND
GRAPHICS ON WFO AMA HOMEPAGE AND FACEBOOK FOR A BETTER REPRESENTATION
OF THIS EVENT THAN CAN BE TYPED IN BLOCK TEXT.
THE NAM AND RUC HAVE DONE A GOOD JOB IN SHOWING A STRONG BAND OF
FRONTOGENETICAL FORCING...THOUGH THE PLACEMENT HAS BEEN TOO FAR EAST.
THIS BAND HAS SET UP OVER THE AFOREMENTIONED ARC AND CONVECTIVE
ENHANCEMENT WITH RATES TO 2-3 INCHES PER HOUR HAVE BEEN NOTED. IN
FACT...WE HAVE OBSERVED AT LEAST A HALF DOZEN CLOUD TO GROUND
STRIKES AT THE NWS AMA OFFICE OVERNIGHT...WITH ABOUT 6 INCHES
ALREADY ON THE GROUND AS OF 4 AM. INTENSE MESOSCALE BANDING SHOULD
PERSIST INTO THE MORING HOURS AND POSSIBLY INTO THE AFTERNOON...
THOUGH RATES WILL LIKELY SUBSIDE A BIT AFTER 18Z.
WINDS...
DOWNWARD MOMENTUM TRANSFER/MIXING OF A DEVELOPING 60-70KT LLJ WILL
RESULT IN FREQUENT GUSTS ABOVE 50 MPH AND POTENTIALLY A FEW GUSTS TO
65 MPH. THE WORST OF THE WINDS WILL OCCUR FROM 12-22Z TODAY.
ALL-IN-ALL...THE WELL ADVERTISED BLIZZARD IS COMING TO FRUITION
FOR THE VAST MAJORITY OF THE PANHANDLES. THE ONLY LOCATIONS THAT
WILL SEE REDUCED SNOWFALL AMOUNTS WILL BE THE FAR NW PANHANDLES...BUT
VERY STRONG WINDS WILL BLOW AROUND ANY MINOR SNOWFALL ACCUMULATIONS
AND STILL CREATE BRIEF BLIZZARD CONDITIONS.
TUESDAY THROUGH SUNDAY...
A COLD AND MAINLY DRY PERIOD WILL BE NOTED UNDER PREDOMINATELY NORTH
WINDS. A FEW WEAK UPR WAVES COULD KICK OFF A FLURRY TUE NIGHT AND
AGAIN THU...BUT NOTHING APPRECIABLE IS EXPECTED. WINDS MIGHT FINALLY
SWING AROUND TO THE SOUTH SAT NIGHT AND SUN...BUT QUICKLY COME BACK
TO THE NORTH BEHIND ANOTHER COLD FRONT ON SUNDAY NIGHT.
SIMPSON
FIRE WEATHER...
ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED
THROUGH NEXT GIVEN THE EXPECTED SNOW COVER.
SIMPSON
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF SMITH...
DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
BEAVER...CIMARRON...TEXAS.
&&
$$
06/14
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1057 AM CST MON FEB 25 2013
.UPDATE...
MADE MINOR ADJUSTMENTS TO THE SNOW AMOUNT GRIDS FROM NOON TO 6 PM TO
ACCOUNT FOR HIGHER SNOWFALL RATES AS THE UPPER LOW LIFTS TO THE NORTH
AND EAST. DURING THIS TIME FRAME 3 TO 6 ADDITIONAL INCHES OF SNOW
WILL BE POSSIBLE ACROSS THE EASTERN OKLAHOMA AND TEXAS PANHANDLE AND
THE SOUTH CENTRAL TEXAS PANHANDLE.
&&
.PREV DISCUSSION... /ISSUED 833 AM CST MON FEB 25 2013/
..CRIPPLING BLIZZARD ROARS ON...
UPDATE...
GOING FORECAST STILL ON TRACK. THE NWS OFFICE NOW HAS OVER 13 INCHES
ON THE GROUND WITH 3-4 FOOT DRIFTS AND A MAX GUST TO 58 MPH. THE SE
TX PANHANDLE HAS BEEN SLOW TO FILL IN WITH SNOW AFTER THE
THUNDERSTORMS THAT DROPPED HEAVY RAIN LAST NIGHT AND THESE AREAS
MIGHT END UP WITH AMOUNTS CLOSER TO THE 8 INCH SIDE THAN THE 14 INCH
SIDE OF THEIR RANGE. AT THE END OF THE DAY...THE HEAVIEST TOTALS
WILL ALMOST CERTAINLY BE ALONG A PALO DURO CANYON TO AMARILLO TO
STINNETT TO PERRYTON LINE.
SOME RECORDS SEEM TO BE IN A PRECARIOUS POSITION TODAY. THE FIRST IS
AN ALL-TIME 24 HOUR SNOWFALL RECORD AT AMARILLO OF 20.6 INCHES FROM
MARCH 25-26 1934. WE WILL LIKELY GET VERY CLOSE OR SURPASS THIS
NUMBER BY THIS AFTERNOON.
THE OTHER IS THE ALL-TIME STATE OF TEXAS 24 HOUR SNOWFALL RECORD OF
25 INCHES IN FOLLETT SET MARCH 28 2009. SOMEWHERE IN THE
PERRYTON/STINNETT/BORGER/AMARILLO AREA COULD APPROACH THIS VALUE BY
THIS AFTERNOON.
SIMPSON
PREV DISCUSSION... /ISSUED 541 AM CST MON FEB 25 2013/
AVIATION.../12Z TAFS/
VERY HAZARDOUS FLYING CONDITIONS EXPECTED TO CONTINUE THROUGH AT
LEAST 00Z AT ALL TERMINALS. HEAVIEST SNOW AND LOWEST VISIBILITIES
WILL BE AT KAMA 15-20Z. AWW REMAINS IN EFFECT FOR KAMA AND TRADEWINDS
AIRPORT UNTIL 00Z.
VFR CONDITIONS ARE EXPECTED TO RETURN TO ALL TERMINALS 00-02Z.
NW WINDS ARE EXPECTED TO SUBSIDE BELOW 12 KT AT ALL TERMINALS BY 04Z.
JACKSON
PREV DISCUSSION... /ISSUED 446 AM CST MON FEB 25 2013/
SNOW PILING UP...WINDS INCREASING AND CREATING FULL FLEDGED BLIZZARD
CONDITIONS AT THIS WRITING...
DISCUSSION...
MAIN CHANGE TO PREVIOUS FORECAST WAS TO ATTEMPT TO PIN POINT THE BAND
OF HIGHEST SNOW TOTALS...WHICH WILL LIKELY STRETCH ALONG AN ARC FROM
TULIA TO AMARILLO TO STINNETT TO SPEARMAN. LOCATIONS ON THIS ARC AND
30 MILES TO THE EAST AND WEST OF IT ARE SET TO RECEIVE AT LEAST A
FOOT OF SNOW...WITH TOTALS UP TO 2 FEET NOT COMPLETELY OUT OF THE
QUESTION. THE REST OF THE PANHANDLES WILL SEE SLIGHTLY LESSER
AMOUNTS...BUT STILL BLIZZARD CONDITIONS. SEE THE BLIZZARD WARNING AND
GRAPHICS ON WFO AMA HOMEPAGE AND FACEBOOK FOR A BETTER REPRESENTATION
OF THIS EVENT THAN CAN BE TYPED IN BLOCK TEXT.
THE NAM AND RUC HAVE DONE A GOOD JOB IN SHOWING A STRONG BAND OF
FRONTOGENETICAL FORCING...THOUGH THE PLACEMENT HAS BEEN TOO FAR EAST.
THIS BAND HAS SET UP OVER THE AFOREMENTIONED ARC AND CONVECTIVE
ENHANCEMENT WITH RATES TO 2-3 INCHES PER HOUR HAVE BEEN NOTED. IN
FACT...WE HAVE OBSERVED AT LEAST A HALF DOZEN CLOUD TO GROUND
STRIKES AT THE NWS AMA OFFICE OVERNIGHT...WITH ABOUT 6 INCHES
ALREADY ON THE GROUND AS OF 4 AM. INTENSE MESOSCALE BANDING SHOULD
PERSIST INTO THE MORING HOURS AND POSSIBLY INTO THE AFTERNOON...
THOUGH RATES WILL LIKELY SUBSIDE A BIT AFTER 18Z.
WINDS...
DOWNWARD MOMENTUM TRANSFER/MIXING OF A DEVELOPING 60-70KT LLJ WILL
RESULT IN FREQUENT GUSTS ABOVE 50 MPH AND POTENTIALLY A FEW GUSTS TO
65 MPH. THE WORST OF THE WINDS WILL OCCUR FROM 12-22Z TODAY.
ALL-IN-ALL...THE WELL ADVERTISED BLIZZARD IS COMING TO FRUITION
FOR THE VAST MAJORITY OF THE PANHANDLES. THE ONLY LOCATIONS THAT
WILL SEE REDUCED SNOWFALL AMOUNTS WILL BE THE FAR NW PANHANDLES...BUT
VERY STRONG WINDS WILL BLOW AROUND ANY MINOR SNOWFALL ACCUMULATIONS
AND STILL CREATE BRIEF BLIZZARD CONDITIONS.
TUESDAY THROUGH SUNDAY...
A COLD AND MAINLY DRY PERIOD WILL BE NOTED UNDER PREDOMINATELY NORTH
WINDS. A FEW WEAK UPR WAVES COULD KICK OFF A FLURRY TUE NIGHT AND
AGAIN THU...BUT NOTHING APPRECIABLE IS EXPECTED. WINDS MIGHT FINALLY
SWING AROUND TO THE SOUTH SAT NIGHT AND SUN...BUT QUICKLY COME BACK
TO THE NORTH BEHIND ANOTHER COLD FRONT ON SUNDAY NIGHT.
SIMPSON
FIRE WEATHER...
ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED
THROUGH NEXT GIVEN THE EXPECTED SNOW COVER.
SIMPSON
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF SMITH...
DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
BEAVER...CIMARRON...TEXAS.
&&
$$
99/14
AREA FORECAST DISCUSSION
NWS AMARILLO TX
833 AM CST MON FEB 25 2013
...CRIPPLING BLIZZARD ROARS ON...
.UPDATE...
GOING FORECAST STILL ON TRACK. THE NWS OFFICE NOW HAS OVER 13 INCHES
ON THE GROUND WITH 3-4 FOOT DRIFTS AND A MAX GUST TO 58 MPH. THE SE
TX PANHANDLE HAS BEEN SLOW TO FILL IN WITH SNOW AFTER THE
THUNDERSTORMS THAT DROPPED HEAVY RAIN LAST NIGHT AND THESE AREAS
MIGHT END UP WITH AMOUNTS CLOSER TO THE 8 INCH SIDE THAN THE 14 INCH
SIDE OF THEIR RANGE. AT THE END OF THE DAY...THE HEAVIEST TOTALS
WILL ALMOST CERTAINLY BE ALONG A PALO DURO CANYON TO AMARILLO TO
STINNETT TO PERRYTON LINE.
SOME RECORDS SEEM TO BE IN A PRECARIOUS POSITION TODAY. THE FIRST IS
AN ALL-TIME 24 HOUR SNOWFALL RECORD AT AMARILLO OF 20.6 INCHES FROM
MARCH 25-26 1934. WE WILL LIKELY GET VERY CLOSE OR SURPASS THIS
NUMBER BY THIS AFTERNOON.
THE OTHER IS THE ALL-TIME STATE OF TEXAS 24 HOUR SNOWFALL RECORD OF
25 INCHES IN FOLLETT SET MARCH 28 2009. SOMEWHERE IN THE
PERRYTON/STINNETT/BORGER/AMARILLO AREA COULD APPROACH THIS VALUE BY
THIS AFTERNOON.
SIMPSON
&&
.PREV DISCUSSION... /ISSUED 541 AM CST MON FEB 25 2013/
AVIATION.../12Z TAFS/
VERY HAZARDOUS FLYING CONDITIONS EXPECTED TO CONTINUE THROUGH AT
LEAST 00Z AT ALL TERMINALS. HEAVIEST SNOW AND LOWEST VISIBILITIES
WILL BE AT KAMA 15-20Z. AWW REMAINS IN EFFECT FOR KAMA AND TRADEWINDS
AIRPORT UNTIL 00Z.
VFR CONDITIONS ARE EXPECTED TO RETURN TO ALL TERMINALS 00-02Z.
NW WINDS ARE EXPECTED TO SUBSIDE BELOW 12 KT AT ALL TERMINALS BY 04Z.
JACKSON
PREV DISCUSSION... /ISSUED 446 AM CST MON FEB 25 2013/
.SNOW PILING UP...WINDS INCREASING AND CREATING FULL FLEDGED BLIZZARD
CONDITIONS AT THIS WRITING...
DISCUSSION...
MAIN CHANGE TO PREVIOUS FORECAST WAS TO ATTEMPT TO PIN POINT THE BAND
OF HIGHEST SNOW TOTALS...WHICH WILL LIKELY STRETCH ALONG AN ARC FROM
TULIA TO AMARILLO TO STINNETT TO SPEARMAN. LOCATIONS ON THIS ARC AND
30 MILES TO THE EAST AND WEST OF IT ARE SET TO RECEIVE AT LEAST A
FOOT OF SNOW...WITH TOTALS UP TO 2 FEET NOT COMPLETELY OUT OF THE
QUESTION. THE REST OF THE PANHANDLES WILL SEE SLIGHTLY LESSER
AMOUNTS...BUT STILL BLIZZARD CONDITIONS. SEE THE BLIZZARD WARNING AND
GRAPHICS ON WFO AMA HOMEPAGE AND FACEBOOK FOR A BETTER REPRESENTATION
OF THIS EVENT THAN CAN BE TYPED IN BLOCK TEXT.
THE NAM AND RUC HAVE DONE A GOOD JOB IN SHOWING A STRONG BAND OF
FRONTOGENETICAL FORCING...THOUGH THE PLACEMENT HAS BEEN TOO FAR EAST.
THIS BAND HAS SET UP OVER THE AFOREMENTIONED ARC AND CONVECTIVE
ENHANCEMENT WITH RATES TO 2-3 INCHES PER HOUR HAVE BEEN NOTED. IN
FACT...WE HAVE OBSERVED AT LEAST A HALF DOZEN CLOUD TO GROUND
STRIKES AT THE NWS AMA OFFICE OVERNIGHT...WITH ABOUT 6 INCHES
ALREADY ON THE GROUND AS OF 4 AM. INTENSE MESOSCALE BANDING SHOULD
PERSIST INTO THE MORING HOURS AND POSSIBLY INTO THE AFTERNOON...
THOUGH RATES WILL LIKELY SUBSIDE A BIT AFTER 18Z.
WINDS...
DOWNWARD MOMENTUM TRANSFER/MIXING OF A DEVELOPING 60-70KT LLJ WILL
RESULT IN FREQUENT GUSTS ABOVE 50 MPH AND POTENTIALLY A FEW GUSTS TO
65 MPH. THE WORST OF THE WINDS WILL OCCUR FROM 12-22Z TODAY.
ALL-IN-ALL...THE WELL ADVERTISED BLIZZARD IS COMING TO FRUITION
FOR THE VAST MAJORITY OF THE PANHANDLES. THE ONLY LOCATIONS THAT
WILL SEE REDUCED SNOWFALL AMOUNTS WILL BE THE FAR NW PANHANDLES...BUT
VERY STRONG WINDS WILL BLOW AROUND ANY MINOR SNOWFALL ACCUMULATIONS
AND STILL CREATE BRIEF BLIZZARD CONDITIONS.
TUESDAY THROUGH SUNDAY...
A COLD AND MAINLY DRY PERIOD WILL BE NOTED UNDER PREDOMINATELY NORTH
WINDS. A FEW WEAK UPR WAVES COULD KICK OFF A FLURRY TUE NIGHT AND
AGAIN THU...BUT NOTHING APPRECIABLE IS EXPECTED. WINDS MIGHT FINALLY
SWING AROUND TO THE SOUTH SAT NIGHT AND SUN...BUT QUICKLY COME BACK
TO THE NORTH BEHIND ANOTHER COLD FRONT ON SUNDAY NIGHT.
SIMPSON
FIRE WEATHER...
ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED
THROUGH NEXT GIVEN THE EXPECTED SNOW COVER.
SIMPSON
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF SMITH...
DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
BEAVER...CIMARRON...TEXAS.
&&
$$
13/09
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
541 AM CST MON FEB 25 2013
.AVIATION.../12Z TAFS/
VERY HAZARDOUS FLYING CONDITIONS EXPECTED TO CONTINUE THROUGH AT
LEAST 00Z AT ALL TERMINALS. HEAVIEST SNOW AND LOWEST VISIBILITIES
WILL BE AT KAMA 15-20Z. AWW REMAINS IN EFFECT FOR KAMA AND TRADEWINDS
AIRPORT UNTIL 00Z.
VFR CONDITIONS ARE EXPECTED TO RETURN TO ALL TERMINALS 00-02Z.
NW WINDS ARE EXPECTED TO SUBSIDE BELOW 12 KT AT ALL TERMINALS BY 04Z.
JACKSON
&&
.PREV DISCUSSION... /ISSUED 446 AM CST MON FEB 25 2013/
..SNOW PILING UP...WINDS INCREASING AND CREATING FULL FLEDGED BLIZZARD
CONDITIONS AT THIS WRITING...
DISCUSSION...
MAIN CHANGE TO PREVIOUS FORECAST WAS TO ATTEMPT TO PIN POINT THE BAND
OF HIGHEST SNOW TOTALS...WHICH WILL LIKELY STRETCH ALONG AN ARC FROM
TULIA TO AMARILLO TO STINNETT TO SPEARMAN. LOCATIONS ON THIS ARC AND
30 MILES TO THE EAST AND WEST OF IT ARE SET TO RECEIVE AT LEAST A
FOOT OF SNOW...WITH TOTALS UP TO 2 FEET NOT COMPLETELY OUT OF THE
QUESTION. THE REST OF THE PANHANDLES WILL SEE SLIGHTLY LESSER
AMOUNTS...BUT STILL BLIZZARD CONDITIONS. SEE THE BLIZZARD WARNING AND
GRAPHICS ON WFO AMA HOMEPAGE AND FACEBOOK FOR A BETTER REPRESENTATION
OF THIS EVENT THAN CAN BE TYPED IN BLOCK TEXT.
THE NAM AND RUC HAVE DONE A GOOD JOB IN SHOWING A STRONG BAND OF
FRONTOGENETICAL FORCING...THOUGH THE PLACEMENT HAS BEEN TOO FAR EAST.
THIS BAND HAS SET UP OVER THE AFOREMENTIONED ARC AND CONVECTIVE
ENHANCEMENT WITH RATES TO 2-3 INCHES PER HOUR HAVE BEEN NOTED. IN
FACT...WE HAVE OBSERVED AT LEAST A HALF DOZEN CLOUD TO GROUND
STRIKES AT THE NWS AMA OFFICE OVERNIGHT...WITH ABOUT 6 INCHES
ALREADY ON THE GROUND AS OF 4 AM. INTENSE MESOSCALE BANDING SHOULD
PERSIST INTO THE MORING HOURS AND POSSIBLY INTO THE AFTERNOON...
THOUGH RATES WILL LIKELY SUBSIDE A BIT AFTER 18Z.
WINDS...
DOWNWARD MOMENTUM TRANSFER/MIXING OF A DEVELOPING 60-70KT LLJ WILL
RESULT IN FREQUENT GUSTS ABOVE 50 MPH AND POTENTIALLY A FEW GUSTS TO
65 MPH. THE WORST OF THE WINDS WILL OCCUR FROM 12-22Z TODAY.
ALL-IN-ALL...THE WELL ADVERTISED BLIZZARD IS COMING TO FRUITION
FOR THE VAST MAJORITY OF THE PANHANDLES. THE ONLY LOCATIONS THAT
WILL SEE REDUCED SNOWFALL AMOUNTS WILL BE THE FAR NW PANHANDLES...BUT
VERY STRONG WINDS WILL BLOW AROUND ANY MINOR SNOWFALL ACCUMULATIONS
AND STILL CREATE BRIEF BLIZZARD CONDITIONS.
TUESDAY THROUGH SUNDAY...
A COLD AND MAINLY DRY PERIOD WILL BE NOTED UNDER PREDOMINATELY NORTH
WINDS. A FEW WEAK UPR WAVES COULD KICK OFF A FLURRY TUE NIGHT AND
AGAIN THU...BUT NOTHING APPRECIABLE IS EXPECTED. WINDS MIGHT FINALLY
SWING AROUND TO THE SOUTH SAT NIGHT AND SUN...BUT QUICKLY COME BACK
TO THE NORTH BEHIND ANOTHER COLD FRONT ON SUNDAY NIGHT.
SIMPSON
FIRE WEATHER...
ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED
THROUGH NEXT GIVEN THE EXPECTED SNOW COVER.
SIMPSON
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF SMITH...
DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
BEAVER...CIMARRON...TEXAS.
&&
$$
JJ/BJS
AREA FORECAST DISCUSSION
NWS AMARILLO TX
446 AM CST MON FEB 25 2013
...SNOW PILING UP...WINDS INCREASING AND CREATING FULL FLEDGED BLIZZARD
CONDITIONS AT THIS WRITING...
.DISCUSSION...
MAIN CHANGE TO PREVIOUS FORECAST WAS TO ATTEMPT TO PIN POINT THE BAND
OF HIGHEST SNOW TOTALS...WHICH WILL LIKELY STRETCH ALONG AN ARC FROM
TULIA TO AMARILLO TO STINNETT TO SPEARMAN. LOCATIONS ON THIS ARC AND
30 MILES TO THE EAST AND WEST OF IT ARE SET TO RECEIVE AT LEAST A
FOOT OF SNOW...WITH TOTALS UP TO 2 FEET NOT COMPLETELY OUT OF THE
QUESTION. THE REST OF THE PANHANDLES WILL SEE SLIGHTLY LESSER
AMOUNTS...BUT STILL BLIZZARD CONDITIONS. SEE THE BLIZZARD WARNING AND
GRAPHICS ON WFO AMA HOMEPAGE AND FACEBOOK FOR A BETTER REPRESENTATION
OF THIS EVENT THAN CAN BE TYPED IN BLOCK TEXT.
THE NAM AND RUC HAVE DONE A GOOD JOB IN SHOWING A STRONG BAND OF
FRONTOGENETICAL FORCING...THOUGH THE PLACEMENT HAS BEEN TOO FAR EAST.
THIS BAND HAS SET UP OVER THE AFOREMENTIONED ARC AND CONVECTIVE
ENHANCEMENT WITH RATES TO 2-3 INCHES PER HOUR HAVE BEEN NOTED. IN
FACT...WE HAVE OBSERVED AT LEAST A HALF DOZEN CLOUD TO GROUND
STRIKES AT THE NWS AMA OFFICE OVERNIGHT...WITH ABOUT 6 INCHES
ALREADY ON THE GROUND AS OF 4 AM. INTENSE MESOSCALE BANDING SHOULD
PERSIST INTO THE MORING HOURS AND POSSIBLY INTO THE AFTERNOON...
THOUGH RATES WILL LIKELY SUBSIDE A BIT AFTER 18Z.
WINDS...
DOWNWARD MOMENTUM TRANSFER/MIXING OF A DEVELOPING 60-70KT LLJ WILL
RESULT IN FREQUENT GUSTS ABOVE 50 MPH AND POTENTIALLY A FEW GUSTS TO
65 MPH. THE WORST OF THE WINDS WILL OCCUR FROM 12-22Z TODAY.
ALL-IN-ALL...THE WELL ADVERTISED BLIZZARD IS COMING TO FRUITION
FOR THE VAST MAJORITY OF THE PANHANDLES. THE ONLY LOCATIONS THAT
WILL SEE REDUCED SNOWFALL AMOUNTS WILL BE THE FAR NW PANHANDLES...BUT
VERY STRONG WINDS WILL BLOW AROUND ANY MINOR SNOWFALL ACCUMULATIONS
AND STILL CREATE BRIEF BLIZZARD CONDITIONS.
TUESDAY THROUGH SUNDAY...
A COLD AND MAINLY DRY PERIOD WILL BE NOTED UNDER PREDOMINATELY NORTH
WINDS. A FEW WEAK UPR WAVES COULD KICK OFF A FLURRY TUE NIGHT AND
AGAIN THU...BUT NOTHING APPRECIABLE IS EXPECTED. WINDS MIGHT FINALLY
SWING AROUND TO THE SOUTH SAT NIGHT AND SUN...BUT QUICKLY COME BACK
TO THE NORTH BEHIND ANOTHER COLD FRONT ON SUNDAY NIGHT.
SIMPSON
&&
.FIRE WEATHER...
ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED
THROUGH NEXT GIVEN THE EXPECTED SNOW COVER.
SIMPSON
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 30 12 35 18 38 / 100 20 5 20 5
BEAVER OK 30 4 35 18 34 / 100 60 5 10 5
BOISE CITY OK 34 12 40 16 35 / 70 5 5 20 5
BORGER TX 32 9 35 21 38 / 100 30 5 20 5
BOYS RANCH TX 34 8 40 21 40 / 100 10 5 20 5
CANYON TX 32 11 35 18 39 / 100 10 5 20 5
CLARENDON TX 31 17 35 22 39 / 100 30 5 10 5
DALHART TX 35 7 40 15 39 / 90 5 5 20 5
GUYMON OK 32 7 37 17 38 / 100 20 5 20 5
HEREFORD TX 33 9 38 18 39 / 100 5 5 20 5
LIPSCOMB TX 32 11 33 20 34 / 100 60 5 10 5
PAMPA TX 27 9 34 19 35 / 100 40 5 20 5
SHAMROCK TX 31 19 35 21 37 / 100 50 5 10 5
WELLINGTON TX 32 21 36 24 40 / 100 40 5 10 5
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF SMITH...
DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...BLIZZARD WARNING UNTIL 3 AM CST TUESDAY FOR THE FOLLOWING ZONES:
BEAVER...CIMARRON...TEXAS.
&&
$$
13/09
AREA FORECAST DISCUSSION
NWS SPOKANE WA
942 PM PST Sun Feb 24 2013
.SYNOPSIS...A winter storm system will affect the Inland Northwest
tonight into Monday, with accumulating snows and breezy winds
expected over most locations. Another quick-moving, weaker system
will affect the region midweek. Warmer weather will make an
appearance late this week, with Spring-like temperatures expected.
&&
.DISCUSSION...
Little if any changes made to current forecast. Majority of
significant precipitation begins roughly near 7Z near the
cascades and more toward 9-10Z for the Spokane area per the most
recent HRRR solutions and the grids and forecast already had a
good handle on that. Other issues of note would be the increase in
post frontal winds as the surface low passing near the Southern
British Columbia border along with the cold front passage increase
the pressure gradient. Perhaps may increase wind near the
Waterville Plateau a bit more upon further scrutiny toward near
Advisory wind gusts amounts. /Pelatti
&&
.AVIATION...
06Z TAFS: A storm system will bring mostly snow as far as
precipitation goes to all TAF sites tonight and continuing into
tomorrow morning. Ceilings associated with the snow should lower
to MVFR/IFR. Wind should increase and be gusty to 30KTS and
perhaps some speed shear type low level wind shear may occur in
the vicinity of east slopes of the Cascades and into some of the
lowlands overnight into tomorrow morning as well. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 41 26 38 28 40 / 60 100 20 0 20 30
Coeur d`Alene 31 38 27 38 26 40 / 50 100 30 10 20 40
Pullman 31 39 27 39 28 42 / 40 100 30 10 10 40
Lewiston 34 48 32 48 32 50 / 20 70 20 0 10 30
Colville 31 41 27 43 26 44 / 80 100 30 10 30 50
Sandpoint 32 37 28 37 24 37 / 60 100 60 10 20 60
Kellogg 30 34 27 36 24 39 / 40 100 80 20 20 60
Moses Lake 33 48 27 48 30 49 / 60 20 0 0 10 10
Wenatchee 31 44 28 46 31 47 / 60 20 10 0 10 10
Omak 25 38 22 37 24 42 / 80 60 0 10 40 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory from 4 AM to 10 PM PST Monday for
Central Panhandle Mountains.
Winter Weather Advisory until 10 AM PST Monday for Coeur d`Alene
Area-Idaho Palouse.
Winter Weather Advisory until 10 AM PST Monday for Northern
Panhandle.
WA...Winter Weather Advisory until 10 AM PST Monday for Spokane Area-
Washington Palouse.
Winter Weather Advisory until 10 AM PST Monday for Northeast
Mountains-Okanogan Highlands.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1059 AM CST MON FEB 25 2013
.SHORT TERM...UPDATE THROUGH THIS AFTERNOON
1031 AM CST MON FEB 25 2013
WATER VAPOR SATELLITE IMAGERY SHOWS A MID-LEVEL TROUGH PUSHING
EAST ACROSS MN AT THIS TIME. RAP SHOWING SOME WEAK ISENTROPIC
UPGLIDE ON THE 285K SURFACE BETWEEN 850-750MB INTO THIS AFTERNOON
MAINLY ACROSS NORTHEAST IA INTO SOUTHWEST WI IN RESPONSE TO THIS WAVE.
PERIODIC/VERY LIGHT SNOW FALLING IN RESPONSE TO THIS LIFT WITH
CHARLES CITY IA REPORTING A VERY LIGHT DUSTING THIS PAST HOUR.
HAVE ADJUSTED FORECAST ACCORDINGLY TO REFLECT THIS SCENARIO INTO
THE AFTERNOON HOURS.
.LONG TERM...THURSDAY THROUGH SUNDAY
320 AM CST MON FEB 25 2013
AFTER THE SYSTEM MOVES OFF TO THE EAST COAST BY MID WEEK...A BROAD
RIDGE OF HIGH PRESSURE WILL EXTEND DOWN FROM NORTH CENTRAL CANADA
DOWN TO THE GULF COAST AND REMAIN ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY REGION INTO NEXT WEEKEND. WHILE THE LOW TO UPPER
LEVEL FLOW WILL BE OUT OF THE NORTH...THERE IS NOT MUCH OF A COLD
SOURCE TO PULL FROM OUT OF CENTRAL CANADA...SO TEMPERATURES SHOULD
NOT TAKE MUCH OF A HIT THROUGH THE WEEK. CLEARING SKIES AND AN
INCREASING SUN ANGLE WILL HELP AS WELL TO KEEP TEMPERATURES NEAR
NORMAL.
&&
.AVIATION...THROUGH 18Z TUESDAY
1058 AM CST MON FEB 25 2013
FAIRLY DIFFICULT FORECAST THROUGH THE NEXT 24 HOURS WITH REGARD
TO LOW CLOUD/FOG POTENTIAL. CURRENTLY THERE IS A MID-LEVEL WAVE
PUSHING EAST ACROSS THE AREA AND THIS HAS BEEN RESPONSIBLE FOR
SOME PERIODIC VERY LIGHT SNOW IN WEAK ISENTROPIC UPGLIDE.
OTHERWISE...VIS/3.9MICRON IMAGERY SURFACE OBSERVATIONS SHOWING
QUITE A BIT OF IFR/LIFR STRATUS AND FOG OUT ACROSS SOUTH CENTRAL
MN/WESTERN IA. EASTERN PERIPHERY OF THIS WAS UNCOMFORTABLY CLOSE
TO KRST TAF SITE. THINKING WITH THE SURFACE RIDGE AXIS LAYING UP
W-E ACROSS THE AREA INTO THIS EVENING ALONG WITH PARTIAL
SNOWMELT LOADING THE LOWER BOUNDARY LAYER WITH ADDITIONAL
MOISTURE...POTENTIAL IS SETTING UP FOR SOME IFR/LIFR CONDITIONS AT
LEAST ACROSS SOUTHEAST MN INCLUDING THE KRST TAF SITE. DON/T THINK
THAT KLSE WILL BE AS BAD AND PLANNING ON CARRYING MVFR CONDITIONS
GOING INTO THIS EVENING. LOW PRESSURE SYSTEM MOVING ACROSS THE
SOUTHERN PLAINS INTO THE BOOTHEEL REGION OF MO OVERNIGHT WILL
BRING AN INCREASING/DRIER LOW LEVEL FLOW INTO THE AREA AFTER
MIDNIGHT AND THINKING THAT THIS WILL IMPROVE CONDITIONS INTO VFR
RANGE. WILL TAKE A CLOSER LOOK AT EVERYTHING BEFORE SENDING OUT
FINALIZED 18Z TAFS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
320 AM CST MON FEB 25 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....HALBACH
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 AM CST MON FEB 25 2013
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
230 AM CST MON FEB 25 2013
THE MAIN FOCUS THROUGH THE NEXT FEW DAYS IS ON THE SNOW
POTENTIAL...PARTICULARLY ON TUESDAY AS A LOW PRESSURE SYSTEM
TRACKS TO THE SOUTH OF THE REGION.
CURRENTLY TRACKING SOME SPOTTY LIGHT SNOW THAT HAS DEVELOPED ALONG
AN INVERTED SURFACE TROUGH AND AHEAD OF A MID LEVEL SHORTWAVE
TROUGH PUSHING INTO WESTERN MINNESOTA. THIS SNOW IS RUNNING INTO
AN AREA OF DRIER AIR AT THE SURFACE DUE TO A RIDGE AXIS THAT RUNS
ACROSS THE SOUTHERN GREAT LAKES TOWARD CENTRAL MINNESOTA. 25.07Z
RAP SOUNDINGS FROM ACROSS SOUTHEAST MINNESOTA INTO WESTERN
WISCONSIN SHOW A DEEPENING SATURATED LAYER THAT COINCIDES WITH THE
WEAK TO MODERATE LIFT FROM LOW LEVEL FRONTOGENESIS THIS MORNING
AND SHOULD HELP TO PROMOTE THE DEVELOPMENT OF THE LIGHT SNOW.
VISIBILITY HAS MAINLY BEEN IN THE 3-6SM RANGE ACROSS SOUTHEAST
MINNESOTA SO FAR THIS MORNING...BUT THERE HAVE BEEN TIMES WHEN IT
HAS DROPPED TO LESS THAN 2SM. REPORTS SO FAR FROM THIS AREA HAVE
BEEN THAT THERE HAS JUST BEEN A TRACE TO PERHAPS A TENTH OR TWO OF
SNOW ACCUMULATION. 25.00Z MESO-MODELS SUGGEST THAT THIS BAND WILL
LIFT TO THE NORTHEAST THIS MORNING TOWARD GREEN BAY AND GENERALLY
DISSIPATE IN COVERAGE AS THE LIFT WEAKENS. STILL KEPT SOME SMALL
CHANCES IN THROUGH 18Z WITH JUST THE TENTH OR TWO OF ACCUMULATION
EXPECTED. THE MAIN CONCERN IS JUST THE TIMING OF IT COMING IN
RIGHT BEFORE THIS MORNINGS COMMUTE WHICH COULD MAKE FOR A FEW
SLICK SPOTS IF IT CAN ACCUMULATE. THE 25.07Z RAP SOUNDINGS ALSO
INDICATE A POSSIBLE LOSS OF ICE LATER THIS MORNING...BUT THINK
THAT THE FORCING WILL HAVE CEASED AT THAT POINT AND IS LIKELY THE
REASON THE MID LEVEL SATURATION ENDS.
AS THE INVERTED SURFACE TROUGH WASHES OUT TODAY AND THE NEXT
SYSTEM TRACKS THROUGH THE OZARKS...THE SURFACE RIDGE AXIS WILL
LIFT NORTH OF THE REGION AND SHOULD KEEP ANY OF THE POTENTIAL FOG
THERE AS WELL. THE DRY LOW LEVEL AIR IN PLACE FROM THE RIDGE IS
ONE OF THE CONCERNS GOING INTO THE NEXT SYSTEM ON TUESDAY AND HOW
FAST THE COLUMN WILL BE ABLE TO SATURATE OUT.
CONFIDENCE REMAINS SOMEWHAT LOW IN HOW THE SYSTEM ON TUESDAY WILL PAN
OUT...BUT THE TREND STILL APPEARS TO BE FOR A SOUTHERN TRACK THAT
MAY KEEP MUCH OF THE FORECAST AREA ON THE DRY SIDE. THE 25.00Z NAM
IS A CONSIDERABLE OUTLIER WITH ITS TRACK TO THE NORTH AND HAS BEEN
CORRECTED WITH THE 25.06Z RUN. 25.00Z GFS/25.06Z NAM BUFKIT
SOUNDINGS SHOW A DRY LAYER BETWEEN 900MB AND 700MB THAT WILL TAKE
SOME TIME TO SATURATE OUT AS THE SYSTEM APPROACHES FROM THE
SOUTHWEST. HAVE REALLY SLOWED DOWN THE TIMING OF THE SNOW MOVING
IN ON TUESDAY FROM THE SOUTH AS THE DRY AIR APPEARS TO WIN OUT FOR
MUCH OF THE DAY. THROUGH 00Z WEDNESDAY...THE BEST CHANCES FOR ANY
SNOW APPEAR TO BE IN CLAYTON/GRANT COUNTIES...THOUGH THE ONLY
25.00Z MODEL THAT HAS ANY SNOW IN THERE BY THAT TIME IS THE GFS
WHICH IS NOTORIOUSLY HIGH ON ITS HUMIDITY AT TIMES. THUS...MORE
ADJUSTMENTS MAY BE NEEDED IN FORECAST AS CONFIDENCE INCREASES THAT
THE SNOW WILL NOT OCCUR. THIS 12Z TUESDAY THROUGH 00Z WEDNESDAY
PERIOD IS CRUCIAL BECAUSE IT IS GOING TO BE THE MAIN TIME FRAME
FOR ANY DECENT SNOWFALL ACCUMULATION. AFTER 00Z WEDNESDAY...THE
SYSTEM LOSES A LOT OF ITS DEEP/STRONG FORCING AS THE LOW FILLS
INTO THE NIGHT. FOR NOW...HAVE MAINTAINED SOME 2-4 INCH SNOW
AMOUNTS FOR CLAYTON/GRANT COUNTY WITH LESS THAN 2 INCHES NORTHWEST
OF THERE TUESDAY INTO TUESDAY NIGHT...BUT AS
MENTIONED...CONFIDENCE IN THIS OCCURRING IS FAIRLY LOW AND BASED
ON THIS WOULD NOT THINK THAT AN ADVISORY IS GOING TO BE NEEDED.
HOW LONG THE LIGHT SNOW MAY LINGER IS ALSO IN QUESTION AS 25.00Z
GFS/25.06Z NAM BUFKIT SOUNDINGS SHOW WEAK LIFT AND DIMINISHING
SATURATION OF THE COLUMN INTO WEDNESDAY NIGHT. MAINTAINED SOME
CHANCES OF SOME LIGHT SNOW WITH THE HIGHEST CHANCES ACROSS
SOUTHWEST WISCONSIN AND NORTHEAST IOWA WHERE THE CORE OF THE UPPER
LEVEL LOW WILL TRACK ACROSS. ANY SNOW AMOUNTS OVER THIS PERIOD
WOULD BE LIGHT AT LESS THAN AN INCH.
.LONG TERM...THURSDAY THROUGH SUNDAY
320 AM CST MON FEB 25 2013
AFTER THE SYSTEM MOVES OFF TO THE EAST COAST BY MID WEEK...A BROAD
RIDGE OF HIGH PRESSURE WILL EXTEND DOWN FROM NORTH CENTRAL CANADA
DOWN TO THE GULF COAST AND REMAIN ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY REGION INTO NEXT WEEKEND. WHILE THE LOW TO UPPER
LEVEL FLOW WILL BE OUT OF THE NORTH...THERE IS NOT MUCH OF A COLD
SOURCE TO PULL FROM OUT OF CENTRAL CANADA...SO TEMPERATURES SHOULD
NOT TAKE MUCH OF A HIT THROUGH THE WEEK. CLEARING SKIES AND AN
INCREASING SUN ANGLE WILL HELP AS WELL TO KEEP TEMPERATURES NEAR
NORMAL.
&&
.AVIATION...TODAY AND TONIGHT
530 AM CST MON FEB 25 2013
CLOUDS WILL BE THE RULE ACROSS THE TAF SITES TODAY/TONIGHT...BUT
MOSTLY BE AOA 3500 FT AS THE LOWER LEVEL AIRMASS ACROSS THE AREA
REMAINS ON THE DRY SIDE. DUE TO A MORE MOIST BOUNDARY LAYER AND WEAK
GRADIENT/LIGHT WINDS...SOME MVFR VSBYS IN BR WILL PREVAIL ACROSS THE
HIGHER TERRAIN AREAS OF NORTHEAST IA/SOUTHEAST MN THRU MUCH OF THIS
MORNING. WEAK FORCING/LIFT WILL CONTINUE TO SPREAD ACROSS THE AREA
EARLY THIS MORNING. THIS LIFT WAS PRODUCING SOME -SN AROUND KLSE
INTO WESTERN WI. AS THE LIFT WEAKENS/EXITS BY MID MORNING THIS -SN
WILL EXIT EAST OF THE KLSE AREA...WITH VFR VSBYS THEN EXPECTED TO
PREVAIL AT BOTH KRST/KLSE FOR THE LATE MORNING HOURS AND THRU
TONIGHT.
CLOUD COVER TONIGHT...AHEAD OF THE SYSTEM LIFTING OUT OF THE
SOUTHERN PLAINS...ALONG WITH INCREASING NORTHEAST WINDS AS THE SFC
LOW LIFTS INTO SOUTHERN MO...ARE EXPECTED TO PREVENT ANY MVFR BR
DEVELOPMENT TONIGHT INTO TUE MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
320 AM CST MON FEB 25 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
320 AM CST MON FEB 25 2013
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
230 AM CST MON FEB 25 2013
THE MAIN FOCUS THROUGH THE NEXT FEW DAYS IS ON THE SNOW
POTENTIAL...PARTICULARLY ON TUESDAY AS A LOW PRESSURE SYSTEM
TRACKS TO THE SOUTH OF THE REGION.
CURRENTLY TRACKING SOME SPOTTY LIGHT SNOW THAT HAS DEVELOPED ALONG
AN INVERTED SURFACE TROUGH AND AHEAD OF A MID LEVEL SHORTWAVE
TROUGH PUSHING INTO WESTERN MINNESOTA. THIS SNOW IS RUNNING INTO
AN AREA OF DRIER AIR AT THE SURFACE DUE TO A RIDGE AXIS THAT RUNS
ACROSS THE SOUTHERN GREAT LAKES TOWARD CENTRAL MINNESOTA. 25.07Z
RAP SOUNDINGS FROM ACROSS SOUTHEAST MINNESOTA INTO WESTERN
WISCONSIN SHOW A DEEPENING SATURATED LAYER THAT COINCIDES WITH THE
WEAK TO MODERATE LIFT FROM LOW LEVEL FRONTOGENESIS THIS MORNING
AND SHOULD HELP TO PROMOTE THE DEVELOPMENT OF THE LIGHT SNOW.
VISIBILITY HAS MAINLY BEEN IN THE 3-6SM RANGE ACROSS SOUTHEAST
MINNESOTA SO FAR THIS MORNING...BUT THERE HAVE BEEN TIMES WHEN IT
HAS DROPPED TO LESS THAN 2SM. REPORTS SO FAR FROM THIS AREA HAVE
BEEN THAT THERE HAS JUST BEEN A TRACE TO PERHAPS A TENTH OR TWO OF
SNOW ACCUMULATION. 25.00Z MESO-MODELS SUGGEST THAT THIS BAND WILL
LIFT TO THE NORTHEAST THIS MORNING TOWARD GREEN BAY AND GENERALLY
DISSIPATE IN COVERAGE AS THE LIFT WEAKENS. STILL KEPT SOME SMALL
CHANCES IN THROUGH 18Z WITH JUST THE TENTH OR TWO OF ACCUMULATION
EXPECTED. THE MAIN CONCERN IS JUST THE TIMING OF IT COMING IN
RIGHT BEFORE THIS MORNINGS COMMUTE WHICH COULD MAKE FOR A FEW
SLICK SPOTS IF IT CAN ACCUMULATE. THE 25.07Z RAP SOUNDINGS ALSO
INDICATE A POSSIBLE LOSS OF ICE LATER THIS MORNING...BUT THINK
THAT THE FORCING WILL HAVE CEASED AT THAT POINT AND IS LIKELY THE
REASON THE MID LEVEL SATURATION ENDS.
AS THE INVERTED SURFACE TROUGH WASHES OUT TODAY AND THE NEXT
SYSTEM TRACKS THROUGH THE OZARKS...THE SURFACE RIDGE AXIS WILL
LIFT NORTH OF THE REGION AND SHOULD KEEP ANY OF THE POTENTIAL FOG
THERE AS WELL. THE DRY LOW LEVEL AIR IN PLACE FROM THE RIDGE IS
ONE OF THE CONCERNS GOING INTO THE NEXT SYSTEM ON TUESDAY AND HOW
FAST THE COLUMN WILL BE ABLE TO SATURATE OUT.
CONFIDENCE REMAINS SOMEWHAT LOW IN HOW THE SYSTEM ON TUESDAY WILL PAN
OUT...BUT THE TREND STILL APPEARS TO BE FOR A SOUTHERN TRACK THAT
MAY KEEP MUCH OF THE FORECAST AREA ON THE DRY SIDE. THE 25.00Z NAM
IS A CONSIDERABLE OUTLIER WITH ITS TRACK TO THE NORTH AND HAS BEEN
CORRECTED WITH THE 25.06Z RUN. 25.00Z GFS/25.06Z NAM BUFKIT
SOUNDINGS SHOW A DRY LAYER BETWEEN 900MB AND 700MB THAT WILL TAKE
SOME TIME TO SATURATE OUT AS THE SYSTEM APPROACHES FROM THE
SOUTHWEST. HAVE REALLY SLOWED DOWN THE TIMING OF THE SNOW MOVING
IN ON TUESDAY FROM THE SOUTH AS THE DRY AIR APPEARS TO WIN OUT FOR
MUCH OF THE DAY. THROUGH 00Z WEDNESDAY...THE BEST CHANCES FOR ANY
SNOW APPEAR TO BE IN CLAYTON/GRANT COUNTIES...THOUGH THE ONLY
25.00Z MODEL THAT HAS ANY SNOW IN THERE BY THAT TIME IS THE GFS
WHICH IS NOTORIOUSLY HIGH ON ITS HUMIDITY AT TIMES. THUS...MORE
ADJUSTMENTS MAY BE NEEDED IN FORECAST AS CONFIDENCE INCREASES THAT
THE SNOW WILL NOT OCCUR. THIS 12Z TUESDAY THROUGH 00Z WEDNESDAY
PERIOD IS CRUCIAL BECAUSE IT IS GOING TO BE THE MAIN TIME FRAME
FOR ANY DECENT SNOWFALL ACCUMULATION. AFTER 00Z WEDNESDAY...THE
SYSTEM LOSES A LOT OF ITS DEEP/STRONG FORCING AS THE LOW FILLS
INTO THE NIGHT. FOR NOW...HAVE MAINTAINED SOME 2-4 INCH SNOW
AMOUNTS FOR CLAYTON/GRANT COUNTY WITH LESS THAN 2 INCHES NORTHWEST
OF THERE TUESDAY INTO TUESDAY NIGHT...BUT AS
MENTIONED...CONFIDENCE IN THIS OCCURRING IS FAIRLY LOW AND BASED
ON THIS WOULD NOT THINK THAT AN ADVISORY IS GOING TO BE NEEDED.
HOW LONG THE LIGHT SNOW MAY LINGER IS ALSO IN QUESTION AS 25.00Z
GFS/25.06Z NAM BUFKIT SOUNDINGS SHOW WEAK LIFT AND DIMINISHING
SATURATION OF THE COLUMN INTO WEDNESDAY NIGHT. MAINTAINED SOME
CHANCES OF SOME LIGHT SNOW WITH THE HIGHEST CHANCES ACROSS
SOUTHWEST WISCONSIN AND NORTHEAST IOWA WHERE THE CORE OF THE UPPER
LEVEL LOW WILL TRACK ACROSS. ANY SNOW AMOUNTS OVER THIS PERIOD
WOULD BE LIGHT AT LESS THAN AN INCH.
.LONG TERM...THURSDAY THROUGH SUNDAY
320 AM CST MON FEB 25 2013
AFTER THE SYSTEM MOVES OFF TO THE EAST COAST BY MID WEEK...A BROAD
RIDGE OF HIGH PRESSURE WILL EXTEND DOWN FROM NORTH CENTRAL CANADA
DOWN TO THE GULF COAST AND REMAIN ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY REGION INTO NEXT WEEKEND. WHILE THE LOW TO UPPER
LEVEL FLOW WILL BE OUT OF THE NORTH...THERE IS NOT MUCH OF A COLD
SOURCE TO PULL FROM OUT OF CENTRAL CANADA...SO TEMPERATURES SHOULD
NOT TAKE MUCH OF A HIT THROUGH THE WEEK. CLEARING SKIES AND AN
INCREASING SUN ANGLE WILL HELP AS WELL TO KEEP TEMPERATURES NEAR
NORMAL.
&&
.AVIATION...THROUGH 06Z TUESDAY
1149 PM CST SUN FEB 24 2013
CLOUDS ARE NOW FIRMLY ENTRENCHED AT THE TAF SITES. A THICK UPPER
CLOUD HAS ALSO FORMED ABOVE THE LOWEST CEILING LAYER...WHICH WILL
PREVENT IFR FOG FROM FORMING THROUGH MORNING. HOWEVER...SOME MVFR
BR AND LOWER MVFR CIGS ARE EXPECTED TO FORM AS A BAND OF LIFT
ACROSS KRST BEGINS TO CAUSE SOME -SHSN AND BETTER SATURATION IN THE
BOUNDARY LAYER. CURRENT THINKING ON THE -SNSH IS THAT IT WILL BE
SPOTTY NEAR KRST UNTIL THE NEAR-DAWN HOURS MONDAY WHEN A LIGHT
SNOW PERIOD IS POSSIBLE. THIS MAY CAUSE PERIODIC IFR SHOULD THE
LIFT BE STRONG ENOUGH TO SATURATE THE LOW-LEVELS. KLSE MAY SEE A
FEW -SHSN BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN THE
TAF.
THIS LIFT WILL PASS OF TO THE NORTHEAST BY LATER MORNING ENDING
THE SHSN ACTIVITY...WITH IMPROVING CONDITIONS TO VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
320 AM CST MON FEB 25 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 PM CST SUN FEB 24 2013
.SHORT TERM...
1008 PM CST SUN FEB 24 2013
TOUGH LITTLE FORECAST TONIGHT WITH DETAILS IN A MESSY
PATTERN. WAS WORKING TO TRY AND FIGURE OUT THE FORECAST OF THE BAND
OF WEAK ECHO FROM ROUGHLY OMAHA TO ROCHESTER MN AND ITS IMPACT
LATE TONIGHT. BIGGEST CONCERN IS A BIT OF LIGHT ACCUMULATING SNOW
AROUND COMMUTE TIME.
TWO LEVELS OF CLOUDS ARE SLOWLY WORKING INTO THE AREA FROM THE
SOUTHWEST. WEST OF THE MISS RIVER A LOWER LEVEL CLOUD DECK IS
KEEPING TEMPERATURES WARMER THAN FORECAST AND HAVE ADJUSTED THESE
AND WITH MORE CLOUD OVERNIGHT...HAVE RAISED OVERNIGHT LOWS BY
A2-3F THERE. CLEARING IN CENTRAL WI WILL CONTINUE TO PROMOTE
COOLING AND FOG IN THE RIDGE AXIS. WITH CLOUDS COMING IN
THOUGH...ANY DENSE FOG SHOULD BE SHORT LIVED SO CONTINUED THE
TREND OF NO FOG AFTER 09Z SOUTH OF I-94.
FRONTOGENETIC BAND BETWEEN NORTHERN SYSTEM AND SOUTHERN SYSTEM IS
CAUSING ENOUGH LIFT FOR THE ECHO BAND MENTIONED ABOVE FROM OMAHA
NORTHEAST. GUIDANCE HAVE MIXED REVIEWS ON THIS BAND BUT OVERALL IT
SHOULD INTENSIFY OVER IOWA AND SHIFT NORTHEAST OVERNIGHT. NEW
25.00Z NAM HAS ABOUT 0.5 INCHES ACROSS SERN MN/NERN IA BY MID-
MORNING. 24.18Z GFS AND RAP ALSO SHOW MEASURABLE SNOW. SO...HAVE
TAKEN A STEP TOWARD LIGHT SNOW MOVING IN BY SUNRISE. THEN...THE
SNOWS SHIFT NORTHEAST AND THE FORCING DOES WEAKEN.
THEREFORE...HAVE LEFT FLURRIES IN THE MORNING OVER THE NORTHWEST
FORECAST AREA. THE RAOB AT KMPX AT 00Z IS QUITE DRY...BUT IT IS
MORE MOIST FURTHER SOUTH.
SYSTEM TO THE SOUTH WILL BE VERY CLOSE WITH THE NEW 25.00Z NAM
COMING IN WITH HIGHER AMOUNTS. THE FAR SOUTH /GRANT AND FAYETTE
COUNTIES/ ARE VERY CLOSE TO A WATCH WITH SOME HIGHER WIND GUSTS
ALSO INVOLVED. WITH THE 24.18Z GFS SUGGESTING 8 INCHES AS THE
HIGH OUTLIER AS OF LATE. WILL NOT MAKE CHANGES NOW...BUT A HIGH
END ADVISORY IS A SURE BET IT APPEARS.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
306 PM CST SUN FEB 24 2013
THE LONG TERM FORECAST CONTINUES TO LOOK QUIET. GOOD MODEL AGREEMENT
CONTINUES AMONGST THE 24.12Z ECMWF/GFS/CANADIAN AND ECMWF
ENSEMBLES...WHICH SHOW RIDGING BUILDING UP OVER THE WESTERN U.S.
THROUGH SATURDAY WHILE TROUGHING HANGS IN PLACE OVER THE EASTERN
U.S.. THE FORECAST AREA IS CAUGHT IN THE MIDDLE BETWEEN THE
TWO...FAVORING A RIDGE OF HIGH PRESSURE WHICH SLOWLY BUILDS EAST
INTO THE FORECAST AREA DURING THIS PERIOD. THERE ARE INDICATIONS OF
A SHORTWAVE TROUGH DROPPING SOUTH THROUGH THE AREA ON FRIDAY...BUT
THERE ARE BOTH UNCERTAINTIES EXACTLY ON WHERE IT TRACKS AND WHETHER
IT WILL HAVE ENOUGH MOISTURE TO PRODUCE PRECIPITATION. THEREFORE...
AFTER SOME LINGERING SMALL PRECIPITATION CHANCES OVER WISCONSIN
AREAS WEDNESDAY NIGHT ASSOCIATED WITH THE SLOWLY DEPARTING AND
WEAKENING STORM TO OUR EAST...HAVE A DRY FORECAST FOR THURSDAY INTO
SATURDAY. HEADING INTO SUNDAY...A MORE POTENT SHORTWAVE TROUGH LOOKS
TO CRASH THROUGH THE WESTERN U.S. RIDGE...BUT ONLY MAKE IT INTO THE
NORTHERN ROCKIES BY 00Z MONDAY. IT SHOULD BE ENOUGH TO PUSH SOME OF
THE UPPER RIDGE EAST...ALLOWING THE SURFACE HIGH PRESSURE RIDGE TO
AT LEAST MOVE OVER IF NOT SHIFT OFF TO THE EAST FORECAST AREA.
NEEDLESS TO SAY...ANOTHER DRY DAY IS ANTICIPATED SUNDAY.
TEMPERATURES ARE A LITTLE TOUGH GIVEN A NORTHERLY FLOW PRESENT WHICH
BRINGS DOWN SOME COOLER AIR FOR MUCH OF THE PERIOD. HOWEVER...IT IS
NOT THAT COLD...NOTED BY 850MB TEMPS AT MOST DROPPING TO -8 TO -12C
BY FRIDAY. ANY SUNSHINE THAT OCCURS...WHICH MORE COULD HAPPEN IF THE
ECMWF IS RIGHT...WILL ALLOW FOR GOOD MIXING. THUS HAVE LEFT A
CONSENSUS APPROACH WHICH YIELDS HIGHS JUST SLIGHTLY BELOW NORMAL.
&&
.AVIATION...THROUGH 06Z TUESDAY
1149 PM CST SUN FEB 24 2013
CLOUDS ARE NOW FIRMLY ENTRENCHED AT THE TAF SITES. A THICK UPPER
CLOUD HAS ALSO FORMED ABOVE THE LOWEST CEILING LAYER...WHICH WILL
PREVENT IFR FOG FROM FORMING THROUGH MORNING. HOWEVER...SOME MVFR
BR AND LOWER MVFR CIGS ARE EXPECTED TO FORM AS A BAND OF LIFT
ACROSS KRST BEGINS TO CAUSE SOME -SHSN AND BETTER SATURATION IN THE
BOUNDARY LAYER. CURRENT THINKING ON THE -SNSH IS THAT IT WILL BE
SPOTTY NEAR KRST UNTIL THE NEAR-DAWN HOURS MONDAY WHEN A LIGHT
SNOW PERIOD IS POSSIBLE. THIS MAY CAUSE PERIODIC IFR SHOULD THE
LIFT BE STRONG ENOUGH TO SATURATE THE LOW-LEVELS. KLSE MAY SEE A
FEW -SHSN BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN THE
TAF.
THIS LIFT WILL PASS OF TO THE NORTHEAST BY LATER MORNING ENDING
THE SHSN ACTIVITY...WITH IMPROVING CONDITIONS TO VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 PM CST SUN FEB 24 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1008 PM CST SUN FEB 24 2013
.SHORT TERM...
1008 PM CST SUN FEB 24 2013
TOUGH LITTLE FORECAST TONIGHT WITH DETAILS IN A MESSY
PATTERN. WAS WORKING TO TRY AND FIGURE OUT THE FORECAST OF THE BAND
OF WEAK ECHO FROM ROUGHLY OMAHA TO ROCHESTER MN AND ITS IMPACT
LATE TONIGHT. BIGGEST CONCERN IS A BIT OF LIGHT ACCUMULATING SNOW
AROUND COMMUTE TIME.
TWO LEVELS OF CLOUDS ARE SLOWLY WORKING INTO THE AREA FROM THE
SOUTHWEST. WEST OF THE MISS RIVER A LOWER LEVEL CLOUD DECK IS
KEEPING TEMPERATURES WARMER THAN FORECAST AND HAVE ADJUSTED THESE
AND WITH MORE CLOUD OVERNIGHT...HAVE RAISED OVERNIGHT LOWS BY
A2-3F THERE. CLEARING IN CENTRAL WI WILL CONTINUE TO PROMOTE
COOLING AND FOG IN THE RIDGE AXIS. WITH CLOUDS COMING IN
THOUGH...ANY DENSE FOG SHOULD BE SHORT LIVED SO CONTINUED THE
TREND OF NO FOG AFTER 09Z SOUTH OF I-94.
FRONTOGENETIC BAND BETWEEN NORTHERN SYSTEM AND SOUTHERN SYSTEM IS
CAUSING ENOUGH LIFT FOR THE ECHO BAND MENTIONED ABOVE FROM OMAHA
NORTHEAST. GUIDANCE HAVE MIXED REVIEWS ON THIS BAND BUT OVERALL IT
SHOULD INTENSIFY OVER IOWA AND SHIFT NORTHEAST OVERNIGHT. NEW
25.00Z NAM HAS ABOUT 0.5 INCHES ACROSS SERN MN/NERN IA BY MID-
MORNING. 24.18Z GFS AND RAP ALSO SHOW MEASURABLE SNOW. SO...HAVE
TAKEN A STEP TOWARD LIGHT SNOW MOVING IN BY SUNRISE. THEN...THE
SNOWS SHIFT NORTHEAST AND THE FORCING DOES WEAKEN.
THEREFORE...HAVE LEFT FLURRIES IN THE MORNING OVER THE NORTHWEST
FORECAST AREA. THE RAOB AT KMPX AT 00Z IS QUITE DRY...BUT IT IS
MORE MOSIT FURTHER SOUTH.
SYSTEM TO THE SOUTH WILL BE VERY CLOSE WITH THE NEW 25.00Z NAM
COMING IN WITH HIGHER AMOUNTS. THE FAR SOUTH /GRANT AND FAYETTE
COUNTIES/ ARE VERY CLOSE TO A WATCH WITH SOME HIGHER WIND GUSTS
ALSO INVOLVED. WITH THE 24.18Z GFS SUGGESTING 8 INCHES AS THE
HIGH OUTLIER AS OF LATE. WILL NOT MAKE CHANGES NOW...BUT A HIGH
END ADVISORY IS A SURE BET IT APPEARS.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
306 PM CST SUN FEB 24 2013
THE LONG TERM FORECAST CONTINUES TO LOOK QUIET. GOOD MODEL AGREEMENT
CONTINUES AMONGST THE 24.12Z ECMWF/GFS/CANADIAN AND ECMWF
ENSEMBLES...WHICH SHOW RIDGING BUILDING UP OVER THE WESTERN U.S.
THROUGH SATURDAY WHILE TROUGHING HANGS IN PLACE OVER THE EASTERN
U.S.. THE FORECAST AREA IS CAUGHT IN THE MIDDLE BETWEEN THE
TWO...FAVORING A RIDGE OF HIGH PRESSURE WHICH SLOWLY BUILDS EAST
INTO THE FORECAST AREA DURING THIS PERIOD. THERE ARE INDICATIONS OF
A SHORTWAVE TROUGH DROPPING SOUTH THROUGH THE AREA ON FRIDAY...BUT
THERE ARE BOTH UNCERTAINTIES EXACTLY ON WHERE IT TRACKS AND WHETHER
IT WILL HAVE ENOUGH MOISTURE TO PRODUCE PRECIPITATION. THEREFORE...
AFTER SOME LINGERING SMALL PRECIPITATION CHANCES OVER WISCONSIN
AREAS WEDNESDAY NIGHT ASSOCIATED WITH THE SLOWLY DEPARTING AND
WEAKENING STORM TO OUR EAST...HAVE A DRY FORECAST FOR THURSDAY INTO
SATURDAY. HEADING INTO SUNDAY...A MORE POTENT SHORTWAVE TROUGH LOOKS
TO CRASH THROUGH THE WESTERN U.S. RIDGE...BUT ONLY MAKE IT INTO THE
NORTHERN ROCKIES BY 00Z MONDAY. IT SHOULD BE ENOUGH TO PUSH SOME OF
THE UPPER RIDGE EAST...ALLOWING THE SURFACE HIGH PRESSURE RIDGE TO
AT LEAST MOVE OVER IF NOT SHIFT OFF TO THE EAST FORECAST AREA.
NEEDLESS TO SAY...ANOTHER DRY DAY IS ANTICIPATED SUNDAY.
TEMPERATURES ARE A LITTLE TOUGH GIVEN A NORTHERLY FLOW PRESENT WHICH
BRINGS DOWN SOME COOLER AIR FOR MUCH OF THE PERIOD. HOWEVER...IT IS
NOT THAT COLD...NOTED BY 850MB TEMPS AT MOST DROPPING TO -8 TO -12C
BY FRIDAY. ANY SUNSHINE THAT OCCURS...WHICH MORE COULD HAPPEN IF THE
ECMWF IS RIGHT...WILL ALLOW FOR GOOD MIXING. THUS HAVE LEFT A
CONSENSUS APPROACH WHICH YIELDS HIGHS JUST SLIGHTLY BELOW NORMAL.
&&
.AVIATION...TONIGHT AND TUESDAY
626 PM CST SUN FEB 24 2013
A CHALLENGING CLOUD AND FOG FORECAST OVERNIGHT INTO MONDAY. AT
00Z...A NORTHEAST-SOUTHWEST ORIENTED MVFR STRATUS DECK IS LOCATED
FROM SERN MN TO OMAHA NEBRASKA. KRST NOW IS IN THIS STRATUS...
WHICH IS SPREADING SLOWLY NORTHEAST. THIS WILL WORK INTO KLSE
SHORTLY. SOME HIGHER CLOUD OVER THE TOP OF THE MVFR STRATUS IS ALSO
SPREADING NORTHEAST FROM THE BIGGER STORM SYSTEM OVER THE SOUTHERN
PLAINS. WITH LIGHT WINDS AND SURFACE RIDGING IN PLACE AND LIGHT
WINDS...AS OVERNIGHT TEMPERATURES COOL...THE STRATUS IS EXPECTED
TO SLOWLY LOWER AS THE BOUNDARY LAYER SATURATES.
AT THIS TIME THE NEW TAFS HAVE SLOWED THE DETERIORATION TO IFR AT
KRST TO AFTER 06Z. BUT HAVE ALSO LOWERED THE VSBYS TO 1 MILE BY
MORNING...AND IT COULD BE LIFR CIG/VSBY SHOULD THE CONDITIONS COME
TOGETHER RIGHT AND THE SECOND LAYER OF CLOUD ABOVE THE STRATUS IS
MINIMAL.
THOSE WITH FLYING INTERESTS IN THE MORNING SHOULD AT LEAST PLAN ON
LOWER MVFR...POSSIBLY DOWN TO LIFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 PM CST SUN FEB 24 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
150 AM MST WED FEB 27 2013
.UPDATE...
ISSUED AT 141 AM MST WED FEB 27 2013
ALTHOUGH STARTING TO TREND DOWNWARD...SNOW AND BLOWING SNOW CONTINUES
OVER THE PALMER DIVIDE. EXTENDED WINTER WEATHER ADVISORY FOR SNOW
AND BLOWING SNOW FOR THE DIVIDE THROUGH 5 AM. UPDATED SHORT TERM
FORECASTS TO REFLECT CURRENT OBSERVATIONS AND TRENDS. LW
UPDATE ISSUED AT 1022 PM MST TUE FEB 26 2013
SNOW GRADUALLY WINDING DOWN OVER NORTHERN EL PASO COUNTY...THOUGH
STILL A COUPLE MORE NARROW BANDS OF AT LEAST BRIEFLY MODERATE
SNOW POSSIBLE OVER EXTREME NERN PART OF THE COUNTY AS AREA OF
HIGHER REFLECTIVITY EAST OF DENVER METRO ROTATES SOUTH. EXPECT ANY
ADDITIONAL ACCUMULATIONS TO BE GENERALLY AN INCH OR LESS. WINDS
STILL GUSTING 25-35 KNOTS FROM KFLY AND KMNH EAST TO KLIC...AND
LATEST HRRR KEEPS GUSTS IN THE 25-30 KT RANGE UNTIL AROUND 09Z-
10Z. WILL KEEP ADVISORY IN PLACE UNTIL 09Z...AS LOCAL MEDIA/ROAD
REPORTS CONTINUE TO INDICATE VERY DIFFICULT TRAVEL EAST/NORTHEAST
OF COLORADO SPRINGS DUE TO LOW VIS AND DRIFTING SNOW.
ELSEWHERE...LIGHT SNOW WILL CONTINUE A FEW MORE HOURS MAINLY SOUTH
OF THE ARKANSAS RIVER AND OVER THE WETS/SANGRES...THOUGH
ADDITIONAL ACCUMS HERE LOOK LIGHT...LESS THAN AN INCH.
UPDATE ISSUED AT 740 PM MST TUE FEB 26 2013
ISSUED A SHORT FUSED WINTER WEATHER ADVISORY FOR NORTHERN EL PASO
COUNTY...AS WINDS HAVE INCREASED AND BANDS OF MODERATE TO HEAVY
SNOW CONTINUE TO ROTATE SOUTH. LATEST HRRR KEEPS PRECIP GOING UNTIL
08Z...AND SHOWS WIND GUSTS OVER 30 KTS NEAR THE PALMER DIVIDE
UNTIL AT LEAST 10Z. HAVE HAD NUMEROUS REPORTS OF ROAD
CLOSURES/DIFFICULT TRAVEL DUE TO WIDESPREAD BLOWING/DRIFTING SNOW
NORTH AND EAST OF COS. FORECASTS FOR THE REMAINDER OF THE AREA
WERE REFRESHED TO ACCOUNT FOR ONGOING PRECIP.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 325 PM MST TUE FEB 26 2013
SHORT TERM METEOROLOGICAL ISSUES INCLUDE BUT ARE NOT LIMITED TO
POPS/SNOW AMOUNTS...WINDS AND TEMPERATURES. FORECAST DISTRICT
CURRENTLY NOTING SNOW ACTIVITY...ESPECIALLY OVER THE MOUNTAINS AND
HIGHER TERRAIN AREAS AS WELL AS OVER MANY PORTIONS OF THE I-25
CORRIDOR AS WELL AS AREAS OF GUSTY NORTH WINDS.
AS OF 3 PM MST...REPORTED SNOW AMOUNTS HAVE GENERALLY BEEN
UNDER 4 INCHES...I.E RECENTLY RECEIVED A SPOTTER SNOW REPORT OF
3.5 INCHES OF SNOW 11 MILES TO THE NORTH-NORTHEAST OF CRESTONE IN
CUSTER COUNTY(PUBLIC ZONE 72) WITH LIGHT SNOW CONTINUING.
LATEST SHORT/NEAR-TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS AND REAL-TIME DATA INDICATE THAT THE UPPER DISTURBANCE
WILL CONTINUE TO IMPACT MANY SECTIONS OF THE CWFA INTO TONIGHT
BEFORE SHIFTING EAST OF THE FORECAST DISTRICT BY WEDNESDAY MORNING.
STILL EXPECT THAT 4 TO 8 INCH SNOW TOTALS(INCLUDING SNOW THAT HAS
ALREADY FALLEN EARLIER TODAY...I.E. 12 TO 18 HOUR TIME-RANGE) WILL
BE POSSIBLE OVER MANY MOUNTAIN AND HIGHER FOOTHILL LOCATIONS WITH
2 TO 5 INCHES OF SNOW OVER NORTHERN EL PASO COUNTY AND 2 INCHES OR
LESS OF SNOW ELSEWHERE WILL BE NOTED BEFORE THIS EVENT ENDS LATER
TONIGHT. IN ADDITION...A FEW LOCALLY HIGHER SNOW AMOUNTS WILL ALSO
BE POSSIBLE BY SUNRISE WEDNESDAY.
IN ADDITION TO THE SNOW FROM THIS AFTERNOON INTO TONIGHT...GUSTY
NORTH WINDS AT TIMES ARE ALSO EXPECTED IN COMBINATION WITH CONTINUED
BELOW SEASONAL LATE FEBRUARY TEMPERATURES.
FOR WEDNESDAY...AS UPPER SYSTEM DEPARTS SOUTHERN
COLORADO...ANTICIPATE THAT GENERALLY DRY CONDITIONS IN COMBINATION
WITH CLEARING SKIES...DECREASING WINDS(EXCEPT FOR POSSIBLY FAR
EASTERN SECTIONS) AND WARMER TEMPERATURES(ALTHOUGH STILL BELOW LATE
FEBRUARY CLIMATOLOGICAL AVERAGES) WILL BE NOTED ACROSS THE FORECAST
DISTRICT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM MST TUE FEB 26 2013
WED NIGHT...GENERALLY DRY NW FLOW ALOFT WL BE OVR THE AREA...BUT
THERE COULD BE A FEW SHOWERS OVR THE CONTDVD MAINLY IN THE EVENING
HOURS. FORECAST MODELS DO NOT AGREE ON THE WEATHER FOR LATE THU AND
THU NIGHT. THE GFS HAS THE AREA MOSTLY DRY INTO THE EARLY
AFTERNOON...BUT LATE IN THE AFTERNOON A SHORTWAVE TROF DROPS INTO
SWRN WY AND AHEAD OF THIS SYSTEM...WITH MOISTURE INCREASING AND THE
GFS BRINGS CHANCES FOR SNOW TO THE CENTRAL MTS AND TO THE PIKES PEAK
TELLER COUNTY REGION. THEN THU NIGHT THAT SYSTEM DROP SOUTH THU
CO...SPREADING PCPN CHANCES SOUTHWARD AS WELL. THE NAM AND THE ECMWF
DO NOT HAVE THIS SHORTWAVE TROF AND IS KEEPING THE WEATHER DRY. WL
STICK WITH SOME PCPN IN THE CENTRAL MTS...WITH MAYBE JUST A FEW
SHOWERS OVR THE OTHER MTN PEAKS AND SEE WHAT FUTURE MODEL RUNS BRING.
FRI...AS AN UPR LOW DROPS INTO WRN MO AND ERN KS A FRONT BRING
SOME BREEZY NORTHERLY WINDS TO MUCH OF THE EASTERN CO PLAINS. THE
NAM IS MOSTLY DRY OVR THE AREA FOR FRI...WHILE THE GFS AND ECMWF
BOTH SHOW SOME POTENTIAL FOR PCPN OVR THE MTS AND ERN PLAINS. AN
UPR RIDGE THEN BUILD OVR THE AREA FOR THE WEEKEND...RESULTING IN
DRY WEATHER AND WARMER TEMPS. LATE SUN THE UPR RIDGE GETS
FLATTENED OVR THE AREA AS A NEW UPR LOW MOVES INTO WRN MT. THE
TRACK OF THAT UPR LOW IS THEN QUITE UNCERTAIN AS THE GFS BRINGS IT
SOUTHEASTWARD AND ACRS NORTHEAST CO BY MIDDAY MON WHILE THE ECMWF
STILL HAS IT OVR MT. BY 06Z TUE THE GFS MOVES THE LOW INTO NRN
MO...WHILE THE ECMWF HAS IT OVR SRN MT AND NRN WY. THUS ITS HARD
TO SAY EXACTLY WHAT IS IN STORE FOR THE FORECAST AREA SUN NIGHT
AND MON BUT FOR NOW BOTH MODELS AT LEAST HAVE SOME PCPN OVR THE
CENTRAL MTS. WL PROBABLY SEE A SHORTWAVE RIDGE AND MAINLY DRY
WEATHER OVR THE AREA ON TUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1022 PM MST TUE FEB 26 2013
AT KCOS...STILL A FEW LIGHT -SHSN IN THE AREA AS OF 0530Z...THOUGH
INTENSITY HAS BEEN DECREASING THE LAST COUPLE HOURS. WILL CARRY
-SN IN THE TAF UNTIL AROUND 08Z...ALONG WITH OCCASIONAL MVFR VIS IN
BLOWING SNOW AS GUSTY NORTH WINDS PERSIST. VFR CONDITIONS THEN
EXPECTED FROM EARLY MORNING THROUGH THE DAY WEDNESDAY AS UPPER
SYSTEM PULLS AWAY. NORTH WINDS WILL DIMINISH THROUGH THE
MORNING...GRADUALLY TURNING TO THE SOUTH BY AFTERNOON.
AT KPUB AND KALS...KEPT A MENTION OF VCSH UNTIL 08Z...THOUGH ANY
-SHSN WILL BE VERY BRIEF AND HAVE LITTLE IMPACT. NORTH WINDS WILL
REMAIN GUSTY UNTIL 10-12Z...THEN DIMINISH. ON TUES...EXPECT VFR
CONDITONS WITH MUCH LIGHTER WINDS.
MOUNTAINS AND PALMER DIVIDE WILL CONTINUE TO BE OBSCURRED BY LOW
CLOUDS AND -SHSN THROUGH THE NIGHT...THEN SNOW ENDS AND SKIES
GRADUALLY CLEAR AROUND SUNRISE. OVER THE PLAINS...ISOLATED MVFR
CIGS/VIS IN -SHSN WILL COME TO AND END 08Z-10Z WITH VFR MOST AREAS
BY 12Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR
COZ084.
&&
$$
UPDATE...LW
SHORT TERM...77
LONG TERM...28
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1039 PM MST TUE FEB 26 2013
.UPDATE...
ISSUED AT 1022 PM MST TUE FEB 26 2013
SNOW GRADUALLY WINDING DOWN OVER NORTHERN EL PASO COUNTY...THOUGH
STILL A COUPLE MORE NARROW BANDS OF AT LEAST BRIEFLY MODERATE
SNOW POSSIBLE OVER EXTREME NERN PART OF THE COUNTY AS AREA OF
HIGHER REFLECTIVITY EAST OF DENVER METRO ROTATES SOUTH. EXPECT ANY
ADDITIONAL ACCUMULATIONS TO BE GENERALLY AN INCH OR LESS. WINDS
STILL GUSTING 25-35 KNOTS FROM KFLY AND KMNH EAST TO KLIC...AND
LATEST HRRR KEEPS GUSTS IN THE 25-30 KT RANGE UNTIL AROUND 09Z-
10Z. WILL KEEP ADVISORY IN PLACE UNTIL 09Z...AS LOCAL MEDIA/ROAD
REPORTS CONTINUE TO INDICATE VERY DIFFICULT TRAVEL EAST/NORTHEAST
OF COLORADO SPRINGS DUE TO LOW VIS AND DRIFTING SNOW.
ELSEWHERE...LIGHT SNOW WILL CONTINUE A FEW MORE HOURS MAINLY SOUTH
OF THE ARKANSAS RIVER AND OVER THE WETS/SANGRES...THOUGH
ADDITIONAL ACCUMS HERE LOOK LIGHT...LESS THAN AN INCH.
UPDATE ISSUED AT 740 PM MST TUE FEB 26 2013
ISSUED A SHORT FUSED WINTER WEATHER ADVISORY FOR NORTHERN EL PASO
COUNTY...AS WINDS HAVE INCREASED AND BANDS OF MODERATE TO HEAVY
SNOW CONTINUE TO ROTATE SOUTH. LATEST HRRR KEEPS PRECIP GOING UNTIL
08Z...AND SHOWS WIND GUSTS OVER 30 KTS NEAR THE PALMER DIVIDE
UNTIL AT LEAST 10Z. HAVE HAD NUMEROUS REPORTS OF ROAD
CLOSURES/DIFFICULT TRAVEL DUE TO WIDESPREAD BLOWING/DRIFTING SNOW
NORTH AND EAST OF COS. FORECASTS FOR THE REMAINDER OF THE AREA
WERE REFRESHED TO ACCOUNT FOR ONGOING PRECIP.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 325 PM MST TUE FEB 26 2013
SHORT TERM METEOROLOGICAL ISSUES INCLUDE BUT ARE NOT LIMITED TO
POPS/SNOW AMOUNTS...WINDS AND TEMPERATURES. FORECAST DISTRICT
CURRENTLY NOTING SNOW ACTIVITY...ESPECIALLY OVER THE MOUNTAINS AND
HIGHER TERRAIN AREAS AS WELL AS OVER MANY PORTIONS OF THE I-25
CORRIDOR AS WELL AS AREAS OF GUSTY NORTH WINDS.
AS OF 3 PM MST...REPORTED SNOW AMOUNTS HAVE GENERALLY BEEN
UNDER 4 INCHES...I.E RECENTLY RECEIVED A SPOTTER SNOW REPORT OF
3.5 INCHES OF SNOW 11 MILES TO THE NORTH-NORTHEAST OF CRESTONE IN
CUSTER COUNTY(PUBLIC ZONE 72) WITH LIGHT SNOW CONTINUING.
LATEST SHORT/NEAR-TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS AND REAL-TIME DATA INDICATE THAT THE UPPER DISTURBANCE
WILL CONTINUE TO IMPACT MANY SECTIONS OF THE CWFA INTO TONIGHT
BEFORE SHIFTING EAST OF THE FORECAST DISTRICT BY WEDNESDAY MORNING.
STILL EXPECT THAT 4 TO 8 INCH SNOW TOTALS(INCLUDING SNOW THAT HAS
ALREADY FALLEN EARLIER TODAY...I.E. 12 TO 18 HOUR TIME-RANGE) WILL
BE POSSIBLE OVER MANY MOUNTAIN AND HIGHER FOOTHILL LOCATIONS WITH
2 TO 5 INCHES OF SNOW OVER NORTHERN EL PASO COUNTY AND 2 INCHES OR
LESS OF SNOW ELSEWHERE WILL BE NOTED BEFORE THIS EVENT ENDS LATER
TONIGHT. IN ADDITION...A FEW LOCALLY HIGHER SNOW AMOUNTS WILL ALSO
BE POSSIBLE BY SUNRISE WEDNESDAY.
IN ADDITION TO THE SNOW FROM THIS AFTERNOON INTO TONIGHT...GUSTY
NORTH WINDS AT TIMES ARE ALSO EXPECTED IN COMBINATION WITH CONTINUED
BELOW SEASONAL LATE FEBRUARY TEMPERATURES.
FOR WEDNESDAY...AS UPPER SYSTEM DEPARTS SOUTHERN
COLORADO...ANTICIPATE THAT GENERALLY DRY CONDITIONS IN COMBINATION
WITH CLEARING SKIES...DECREASING WINDS(EXCEPT FOR POSSIBLY FAR
EASTERN SECTIONS) AND WARMER TEMPERATURES(ALTHOUGH STILL BELOW LATE
FEBRUARY CLIMATOLOGICAL AVERAGES) WILL BE NOTED ACROSS THE FORECAST
DISTRICT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM MST TUE FEB 26 2013
WED NIGHT...GENERALLY DRY NW FLOW ALOFT WL BE OVR THE AREA...BUT
THERE COULD BE A FEW SHOWERS OVR THE CONTDVD MAINLY IN THE EVENING
HOURS. FORECAST MODELS DO NOT AGREE ON THE WEATHER FOR LATE THU AND
THU NIGHT. THE GFS HAS THE AREA MOSTLY DRY INTO THE EARLY
AFTERNOON...BUT LATE IN THE AFTERNOON A SHORTWAVE TROF DROPS INTO
SWRN WY AND AHEAD OF THIS SYSTEM...WITH MOISTURE INCREASING AND THE
GFS BRINGS CHANCES FOR SNOW TO THE CENTRAL MTS AND TO THE PIKES PEAK
TELLER COUNTY REGION. THEN THU NIGHT THAT SYSTEM DROP SOUTH THU
CO...SPREADING PCPN CHANCES SOUTHWARD AS WELL. THE NAM AND THE ECMWF
DO NOT HAVE THIS SHORTWAVE TROF AND IS KEEPING THE WEATHER DRY. WL
STICK WITH SOME PCPN IN THE CENTRAL MTS...WITH MAYBE JUST A FEW
SHOWERS OVR THE OTHER MTN PEAKS AND SEE WHAT FUTURE MODEL RUNS BRING.
FRI...AS AN UPR LOW DROPS INTO WRN MO AND ERN KS A FRONT BRING
SOME BREEZY NORTHERLY WINDS TO MUCH OF THE EASTERN CO PLAINS. THE
NAM IS MOSTLY DRY OVR THE AREA FOR FRI...WHILE THE GFS AND ECMWF
BOTH SHOW SOME POTENTIAL FOR PCPN OVR THE MTS AND ERN PLAINS. AN
UPR RIDGE THEN BUILD OVR THE AREA FOR THE WEEKEND...RESULTING IN
DRY WEATHER AND WARMER TEMPS. LATE SUN THE UPR RIDGE GETS
FLATTENED OVR THE AREA AS A NEW UPR LOW MOVES INTO WRN MT. THE
TRACK OF THAT UPR LOW IS THEN QUITE UNCERTAIN AS THE GFS BRINGS IT
SOUTHEASTWARD AND ACRS NORTHEAST CO BY MIDDAY MON WHILE THE ECMWF
STILL HAS IT OVR MT. BY 06Z TUE THE GFS MOVES THE LOW INTO NRN
MO...WHILE THE ECMWF HAS IT OVR SRN MT AND NRN WY. THUS ITS HARD
TO SAY EXACTLY WHAT IS IN STORE FOR THE FORECAST AREA SUN NIGHT
AND MON BUT FOR NOW BOTH MODELS AT LEAST HAVE SOME PCPN OVR THE
CENTRAL MTS. WL PROBABLY SEE A SHORTWAVE RIDGE AND MAINLY DRY
WEATHER OVR THE AREA ON TUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1022 PM MST TUE FEB 26 2013
AT KCOS...STILL A FEW LIGHT -SHSN IN THE AREA AS OF 0530Z...THOUGH
INTENSITY HAS BEEN DECREASING THE LAST COUPLE HOURS. WILL CARRY
-SN IN THE TAF UNTIL AROUND 08Z...ALONG WITH OCCASIONAL MVFR VIS IN
BLOWING SNOW AS GUSTY NORTH WINDS PERSIST. VFR CONDITIONS THEN
EXPECTED FROM EARLY MORNING THROUGH THE DAY WEDNESDAY AS UPPER
SYSTEM PULLS AWAY. NORTH WINDS WILL DIMINISH THROUGH THE
MORNING...GRADUALLY TURNING TO THE SOUTH BY AFTERNOON.
AT KPUB AND KALS...KEPT A MENTION OF VCSH UNTIL 08Z...THOUGH ANY
-SHSN WILL BE VERY BRIEF AND HAVE LITTLE IMPACT. NORTH WINDS WILL
REMAIN GUSTY UNTIL 10-12Z...THEN DIMINISH. ON TUES...EXPECT VFR
CONDITONS WITH MUCH LIGHTER WINDS.
MOUNTAINS AND PALMER DIVIDE WILL CONTINUE TO BE OBSCURRED BY LOW
CLOUDS AND -SHSN THROUGH THE NIGHT...THEN SNOW ENDS AND SKIES
GRADUALLY CLEAR AROUND SUNRISE. OVER THE PLAINS...ISOLATED MVFR
CIGS/VIS IN -SHSN WILL COME TO AND END 08Z-10Z WITH VFR MOST AREAS
BY 12Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM MST WEDNESDAY FOR COZ084.
&&
$$
UPDATE...MW
SHORT TERM...77
LONG TERM...28
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
359 AM EST WED FEB 27 2013
.DISCUSSION...
TODAY-TONIGHT...COOL FRONT NEAR OKEECHOBEE SHOULD ONLY SLIDE A
LITTLE MORE TO THE SOUTH AS IT BECOMES NEARLY ALIGNED WITH FLOW
ALOFT. THE MODELS ARE SHOWING AN AREA OF RAINFALL BREAKING OUT
ACROSS THE SOUTHERN PENINSULA AS MOISTURE OVERRUNS THE BOUNDARY.
HOW FAR NORTH THIS OCCURS IS PROBLEMATIC.
THE GFS IS QUITE BULLISH WITH 60 POPS IN MARTIN COUNTY AND EVEN
30 PERCENT ALL THE WAY UP TO BREVARD...WHILE THE NAM HAS VALUES
ABOUT HALF THAT. WILL SIDE CLOSE TO THE NAM AS CURRENTLY THE ONLY
RAINFALL IS OVER FLORIDA BY AND FEEL MOST OF THE PRECIP SHOULD BE
FROM LAKE OKEECHOBEE SOUTHWARD.
MAX TEMPS WILL BE 5-10 DEGREES COOLER THAN YESTERDAY. DEW POINTS
WILL BE NOTICEABLY LOWER ESPECIALLY ACROSS THE NORTH HALF. THE
FRONTAL BOUNDARY WILL SLIDE FARTHER SOUTH TONIGHT WHICH WILL
ALLOW LOWS TONIGHT TO COOL A LITTLE FURTHER...INTO THE MID-UPPER
40S NORTH AND LOWER 50S SOUTH.
THU-FRI...ZONAL FLOW ALOFT EXPECTED OVER THE AREA INTO LATE WEEK
WITH DEEP LOW PRESSURE SYSTEM EVENTUALLY MOVING OFFSHORE OF THE
NORTHEAST U.S. COAST. LOW LEVEL NORTHWEST FLOW WILL CONTINUE TO
TRANSPORT DRIER AND COOLER AIR INTO CENTRAL FLORIDA. HIGHS THURSDAY
EXPECTED TO BE IN THE LOW/MID 70S AND THEN IN THE MID/UPPER 60S
FRIDAY. LOWS FORECAST TO RANGE FROM THE MID 40S TO LOW 50S THURSDAY
NIGHT AND LOW/MID 40S FRIDAY NIGHT. MAY SEE SOME GREATER CLOUD COVER
OVER THE AREA FRIDAY AS GFS INDICATES AN INCREASING MID/UPPER LEVEL
CLOUD DECK OVER THE REGION ASSOCIATED WITH STRONG 150+ KT JET OVER
THE SOUTHEAST UNITED STATES.
SAT-SUN...VIGOROUS SHORTWAVE TROUGH WILL DIG SOUTHWARD INTO THE
GULF OF MEXICO SATURDAY AND ACROSS FLORIDA SAT NIGHT INTO SUNDAY.
LOW LEVEL FLOW WILL REMAIN OUT OF THE W/NW WHICH WILL CONTINUE
GRADUAL COOLING INTO THE WEEKEND. TEMPERATURES WILL BE 10 TO 15
DEGREES BELOW NORMAL AND COULD POTENTIALLY SEE LOWS NEAR FREEZING
OVER FAR NORTHERN LAKE AND VOLUSIA COUNTIES LATE SUNDAY NIGHT.
THE OVERALL AIRMASS WILL REMAIN QUITE DRY WITH PW VALUES AROUND 0.50
INCHES OR LESS. DESPITE THIS THE GFS EXTENDED GUIDANCE KEEPS 20-30
PERCENT POPS OVER THE REGION...DUE TO STRONG TROUGH MOVING THROUGH
THE AREA AND INCREASING LOW LEVEL MOISTURE. STILL FEEL THESE POPS
ARE TOO HIGH...ESPECIALLY WITH THE GFS AND ECMWF NOT SHOWING ANY QPF
OVER EAST CENTRAL FLORIDA. WILL LEAN TOWARD THE ECMWF MOS GUIDANCE
AND KEEP A DRY FORECAST OVER THE AREA.
MON-TUE...UPPER LEVEL TROUGH PUSHES EAST OF THE AREA INTO EARLY NEXT
WEEK WITH HIGH PRESSURE AT THE SURFACE EVENTUALLY BUILDING OVER
FLORIDA. BELOW NORMAL TEMPERATURES EXPECTED TO CONTINUE INTO MON/MON
NIGHT WITH TEMPERATURES WARMING BACK INTO THE 70S TUESDAY. DRY
AIRMASS REMAINS OVER THE AREA...KEEPING RAIN CHANCES OUT OF THE
FORECAST.
&&
.AVIATION...
SOME MVFR CEILINGS HAVE BEEN OCCURRING EARLY THIS MORNING
ESPECIALLY IN THE SOUTH NEAR SLOW MOVING FRONTAL BOUNDARY. DRIER
AIR SLOWLY FILTERING IN SHOULD BRING VFR LATER THIS MORNING.
MVFR CEILINGS MAY RETURN OVER SOUTHERN AREAS BY AFTERNOON AS
MOISTURE OVERRUNS THE FRONTAL BOUNDARY...MAINLY KFPR-KSUA. THERE
COULD ALSO BE SOME LIGHT RAIN THERE.
&&
.MARINE...
TODAY-TONIGHT...WINDS AT 41009 FINALLY PICKED UP TO ADVISORY
LEVELS IN THE LAST FEW HOURS. SHORT RANGE GUIDANCE INDICATES A
WEAKENING PRESSURE GRADIENT BY LATE THIS MORNING AS HIGH PRESSURE
RIDGE NOSES IN BEHIND SLOW MOVING FRONTAL BOUNDARY THAT WILL
SETTLE JUST SOUTH OF THE WATERS.
DUE TO RECENT BUOY TRENDS...WILL EXTEND THE ADVISORY A LITTLE
LONGER FOR THE OFFSHORE WATERS. THE RAP AND LOCAL WRF MODELS SHOW
THE 20 KNOT WINDS ABATING AROUND 9 AM. WINDS SHOULD THEN DROP
BELOW 10 KNOTS THIS AFTERNOON AND INTO EARLY EVENING. THE FRONT
WILL SAG BACK TO THE SOUTH TONIGHT WITH THE MODELS INDICATING A
NORTHWEST WIND SURGE 15-20 KNOTS AFTER MIDNIGHT.
THU-SUN...W/NW WINDS WILL PERSIST INTO LATE WEEK AND THROUGH THE
WEEKEND. PERIODS OF INCREASING WINDS UP TO NEAR/AROUND 20 KNOTS WILL
OCCUR AND CREATE ROUGHER BOATING CONDITIONS...ESPECIALLY OFFSHORE.
&&
.FIRE WEATHER...
TODAY...MIN RH VALUES SHOULD FALL TO AROUND 35 PERCENT ACROSS THE
INTERIOR FROM OSCEOLA NORTH.
THU-FRI...DRY AIRMASS OVER THE AREA WILL PRODUCE MIN RH VALUES
AROUND 30 TO 35 PERCENT OVER MUCH OF THE AREA EACH AFTERNOON.
HOWEVER WIND SPEEDS EXPECTED TO REMAIN JUST BELOW 15 MPH BOTH DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 72 47 73 48 / 10 0 0 0
MCO 77 50 75 51 / 10 10 0 0
MLB 75 51 74 52 / 10 10 0 0
VRB 76 50 74 50 / 20 10 0 0
LEE 74 49 73 49 / 10 0 0 0
SFB 75 49 75 49 / 10 0 0 0
ORL 76 52 74 52 / 10 10 0 0
FPR 75 54 74 50 / 20 10 0 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 9 AM THIS MORNING FOR WATERS FROM
FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM
OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN
INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...LASCODY
LONG TERM....WEITLICH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1156 PM CST TUE FEB 26 2013
.UPDATE...
INITIAL UPPER LOW IS LIFTING NORTHEAST THROUGH THE LOWER OHIO
VALLEY THIS EVENING WHILE THE SECOND UPPER LEVEL SYSTEM IS
PROGRESSING EAST THROUGH KANSAS. SEVERAL IMPULSES AREA MOVING
AROUND THE CYCLONIC FLOW AND ARE HELPING FLARE UP BANDS OF SNOW AS
THEY PASS THROUGH CENTRAL IA. ONE IMPULSE HAS SETTLED SOUTH INTO
NORTHERN MISSOURI WHILE THE NEXT IS NOW MOVING INTO NORTHEAST IOWA
OUT OF WISCONSIN WHILE ANOTHER IS BACK FARTHER EAST AND JUST
MOVING WEST FROM LAKE SUPERIOR. BETWEEN THE ENERGY...DRIER AIR HAS
FILTERED SOUTH AND NOW COVERS NEARLY THE NORTHWEST HALF OF THE
STATE AND HAS TEMPORARILY BROUGHT AN END TO THE SNOW OVER
NORTHWEST HEADLINE AREAS. IMPULSE MOVING INTO NORTHEAST IOWA WILL
HELP SHIFT ANOTHER BAND OF SNOW WESTWARD ACROSS THESE REGIONS.
LATEST SREF 100 MB DEPTH DENDRITIC GROWTH ZONE REMAINS LOCKED ON
TO THESE ENHANCED BANDS. TRENDS CONTINUE TO SUGGEST THE FOCUS FOR
DENDRITIC SNOW IS OVER CENTRAL IOWA THROUGH NOON WEDNESDAY.
ANOTHER 1 TO 3 INCHES LIKELY THROUGH THIS TIME THROUGH THE WARNED
AREA.
&&
.SHORT TERM /TONIGHT/...
WINTER STORM WILL PERSIST THROUGH WEDNESDAY MORNING AS LIGHT TO
MODERATE SNOW BANDING CONTINUES ON THE BACKSIDE OF THE SURFACE LOW
LOCATED IN SOUTHEAST MISSOURI. SURFACE LOW LOOKS TO SLOWLY MIGRATE
NORTHEAST FROM SOUTHEAST MISSOURI INTO CENTRAL ILLINOIS THIS EVENING
INTO TOMORROW MORNING. LEANED TOWARD A SREF/GFS/NAM12 BLEND FOR
TRENDS TONIGHT.
WEAK LIFT WITHIN THE DENDRITIC GROWTH ZONE CONTINUES THIS AFTERNOON
AND TONIGHT...AND EVEN PERSISTS INTO WEDNESDAY MORNING. HIGHER
CONFIDENCE WITH THE ADDITIONAL LIGHT SNOW AMOUNTS THROUGH WEDNESDAY
MORNING RESULTING IN ROUGHLY 1 TO 4 INCHES OF ADDITIONAL SNOW
THROUGH 12Z ACROSS THE WARNING AREA. THE SNOW BAND AXIS LOOKS TO
CONTINUE TO SLOWLY PIVOT COUNTERCLOCKWISE AROUND THE CENTRAL PORTION
OF THE FORECAST RESULTING IN SOME AREAS RECEIVING AN ELONGATED
PERIOD OF MODERATE TO BRIEF HEAVY SNOW THIS EVENING. WITH THE
CURRENT TRACK OF THE SURFACE LOW...NOT EXPECTING THIS BAND TO DRIFT
SOUTHEAST ALL THAT MUCH UNTIL EARLY WEDNESDAY MORNING.
GENERALLY EXPECTING A HALF TO POSSIBLY ONE INCH PER HOUR SNOWFALL
RATES THIS EVENING WITH THE WEAK LIFT IN THE DENDRITIC LAYER. SREF
100MB/50MB DENDRITE GROWTH ZONE PARAMETER DEPICTING 80-90 PERCENT
PROBABILITY OF DENDRITIC SNOW THROUGH TOMORROW AND MATCHES UP WELL
WITH PREVIOUSLY MENTION BAND PIVOTING ACROSS CENTRAL IOWA. BUFR
SOUNDINGS REMAIN DEEPLY SATURATED THROUGH WEDNESDAY MORNING...WITH
THE RAP SHOWING A MID LEVEL DRY LAYER ADVECTING INTO DSM TO ALO AND
MAY SEE A BRIEF BREAK IN THE SNOW MID TO LATE EVENING.
WINDS ATOP THE MIXED LAYER RANGE FROM 25 TO 30KTS THIS AFTERNOON AND
TONIGHT AND EXPECTING BLOWING SNOW IMPACTS TO CONTINUE AS WELL.
LEANED TOWARDS THE GFS/SREF QPF AMOUNTS TONIGHT AS NAM SEEMS TO HIGH
ACROSS THE EAST...ESPECIALLY WITH THE WEAKER FORCING.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
WEAKER LIFT WILL PERSIST INTO WEDNESDAY WITH THE SPC SREF INDICATING
DEEP DENDRITIC GROWTH LAYER CONTINUING THROUGH CENTRAL IOWA. ALL
SOUNDINGS CONTINUE TO ALSO SHOW DEEP SATURATION THROUGH AT LEAST
MIDDAY TOMORROW AND ANTICIPATE THE LIGHT SNOW TO CONTINUE. HAVE
GONE WITH LIKELY TO CATEGORICAL POPS FOR MUCH OF THE AREA UNDER THE
CURRENT HEADLINE WITH THE SHARP CUTOFF ON THE NORTHERN SIDE OF THE
PCPN AREA PERSISTING. WINDS WILL REMAIN RATHER STRONG THROUGH THE
DAY WITH BRISK NORTHWEST FLOW PERSISTING WITH DECENT PRESSURE
GRADIENT. EVENTUALLY...THE FORCING WILL BE DIMINISHING WITH THE
SNOW TAPERING TO FLURRIES BY LATER IN THE DAY. CLOUDINESS IS
EXPECTED TO PERSIST AS WELL IN CYCLONIC FLOW ON BACKSIDE INTO
WEDNESDAY NIGHT WITH AN APPROACHING SHORTWAVE ON THURSDAY AND
THURSDAY NIGHT HELPING THE CLOUDINESS TO MAINTAIN. IN FACT...SOME
WEAK LIFT WITH THIS PASSING WAVE ON FRIDAY MAY HELP TO PRODUCE SOME
FLURRIES IN SOUTHERN IOWA DURING THE DAY.
UPPER RIDGING WILL SLIDE THROUGH THE REGION INTO THE WEEKEND WITH
QUIET WEATHER DURING THIS TIME. TEMPERATURES WILL REMAIN BELOW
NORMAL WITH WIDESPREAD SNOW PACK AND ONLY WEAK ADVECTION UNTIL
SUNDAY NIGHT. THIS WARM ADVECTION IS IN ADVANCE OF THE NEXT SYSTEM
WHICH WILL PASS THROUGH THE REGION ON MONDAY INTO TUESDAY IN BROAD
NORTHWEST FLOW. BOTH GFS AND EURO HAVE INDICATED SOME DECENT
FORCING AND ANTICIPATE PCPN DEVELOPING AND SLIDING ACROSS THE STATE
ON MONDAY INTO EARLY TUESDAY. SOUNDINGS WOULD INDICATE GENERALLY
SNOW DURING THIS TIME ACROSS THE STATE WITH LIGHT TO MODERATE
ACCUMULATIONS EXPECTED.
&&
.AVIATION...27/06Z
BANDS OF LIGHT TO MODERATE SNOW WILL CONTINUE OVERNIGHT ALONG WITH
MVFR TO IFR CIGS. THE CIGS SHOULD MOVE INTO THE KFOD/KMCW AREAS
OVERNIGHT AS WELL AFTER BEGINNING VFR. SNOW WILL GRADUALLY
DIMINISH AFTERNOON ON WEDNESDAY HOWEVER IFR TO MVFR CIGS LIKELY TO
CONTINUE THROUGH THE PERIOD. BREEZY NORTHERLY WINDS OVERNIGHT
WILL BECOME GUSTY AGAIN ON WEDNESDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST WEDNESDAY FOR ADAIR-ADAMS-
APPANOOSE-BLACK HAWK-BOONE-CLARKE-DALLAS-DAVIS-DECATUR-GRUNDY-
HARDIN-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-
POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR AUDUBON-
BREMER-BUTLER-CASS-FRANKLIN-GREENE-GUTHRIE-HAMILTON.
&&
$$
UPDATE...DONAVON
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1101 PM CST TUE FEB 26 2013
.UPDATE...
INITIAL UPPER LOW IS LIFTING NORTHEAST THROUGH THE LOWER OHIO
VALLEY THIS EVENING WHILE THE SECOND UPPER LEVEL SYSTEM IS
PROGRESSING EAST THROUGH KANSAS. SEVERAL IMPULSES AREA MOVING
AROUND THE CYCLONIC FLOW AND ARE HELPING FLARE UP BANDS OF SNOW AS
THEY PASS THROUGH CENTRAL IA. ONE IMPULSE HAS SETTLED SOUTH INTO
NORTHERN MISSOURI WHILE THE NEXT IS NOW MOVING INTO NORTHEAST IOWA
OUT OF WISCONSIN WHILE ANOTHER IS BACK FARTHER EAST AND JUST
MOVING WEST FROM LAKE SUPERIOR. BETWEEN THE ENERGY...DRIER AIR HAS
FILTERED SOUTH AND NOW COVERS NEARLY THE NORTHWEST HALF OF THE
STATE AND HAS TEMPORARILY BROUGHT AN END TO THE SNOW OVER
NORTHWEST HEADLINE AREAS. IMPULSE MOVING INTO NORTHEAST IOWA WILL
HELP SHIFT ANOTHER BAND OF SNOW WESTWARD ACROSS THESE REGIONS.
LATEST SREF 100 MB DEPTH DENDRITIC GROWTH ZONE REMAINS LOCKED ON
TO THESE ENHANCED BANDS. TRENDS CONTINUE TO SUGGEST THE FOCUS FOR
DENDRITIC SNOW IS OVER CENTRAL IOWA THROUGH NOON WEDNESDAY.
ANOTHER 1 TO 3 INCHES LIKELY THROUGH THIS TIME THROUGH THE WARNED
AREA.
&&
.SHORT TERM /TONIGHT/...
WINTER STORM WILL PERSIST THROUGH WEDNESDAY MORNING AS LIGHT TO
MODERATE SNOW BANDING CONTINUES ON THE BACKSIDE OF THE SURFACE LOW
LOCATED IN SOUTHEAST MISSOURI. SURFACE LOW LOOKS TO SLOWLY MIGRATE
NORTHEAST FROM SOUTHEAST MISSOURI INTO CENTRAL ILLINOIS THIS EVENING
INTO TOMORROW MORNING. LEANED TOWARD A SREF/GFS/NAM12 BLEND FOR
TRENDS TONIGHT.
WEAK LIFT WITHIN THE DENDRITIC GROWTH ZONE CONTINUES THIS AFTERNOON
AND TONIGHT...AND EVEN PERSISTS INTO WEDNESDAY MORNING. HIGHER
CONFIDENCE WITH THE ADDITIONAL LIGHT SNOW AMOUNTS THROUGH WEDNESDAY
MORNING RESULTING IN ROUGHLY 1 TO 4 INCHES OF ADDITIONAL SNOW
THROUGH 12Z ACROSS THE WARNING AREA. THE SNOW BAND AXIS LOOKS TO
CONTINUE TO SLOWLY PIVOT COUNTERCLOCKWISE AROUND THE CENTRAL PORTION
OF THE FORECAST RESULTING IN SOME AREAS RECEIVING AN ELONGATED
PERIOD OF MODERATE TO BRIEF HEAVY SNOW THIS EVENING. WITH THE
CURRENT TRACK OF THE SURFACE LOW...NOT EXPECTING THIS BAND TO DRIFT
SOUTHEAST ALL THAT MUCH UNTIL EARLY WEDNESDAY MORNING.
GENERALLY EXPECTING A HALF TO POSSIBLY ONE INCH PER HOUR SNOWFALL
RATES THIS EVENING WITH THE WEAK LIFT IN THE DENDRITIC LAYER. SREF
100MB/50MB DENDRITE GROWTH ZONE PARAMETER DEPICTING 80-90 PERCENT
PROBABILITY OF DENDRITIC SNOW THROUGH TOMORROW AND MATCHES UP WELL
WITH PREVIOUSLY MENTION BAND PIVOTING ACROSS CENTRAL IOWA. BUFR
SOUNDINGS REMAIN DEEPLY SATURATED THROUGH WEDNESDAY MORNING...WITH
THE RAP SHOWING A MID LEVEL DRY LAYER ADVECTING INTO DSM TO ALO AND
MAY SEE A BRIEF BREAK IN THE SNOW MID TO LATE EVENING.
WINDS ATOP THE MIXED LAYER RANGE FROM 25 TO 30KTS THIS AFTERNOON AND
TONIGHT AND EXPECTING BLOWING SNOW IMPACTS TO CONTINUE AS WELL.
LEANED TOWARDS THE GFS/SREF QPF AMOUNTS TONIGHT AS NAM SEEMS TO HIGH
ACROSS THE EAST...ESPECIALLY WITH THE WEAKER FORCING.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
WEAKER LIFT WILL PERSIST INTO WEDNESDAY WITH THE SPC SREF INDICATING
DEEP DENDRITIC GROWTH LAYER CONTINUING THROUGH CENTRAL IOWA. ALL
SOUNDINGS CONTINUE TO ALSO SHOW DEEP SATURATION THROUGH AT LEAST
MIDDAY TOMORROW AND ANTICIPATE THE LIGHT SNOW TO CONTINUE. HAVE
GONE WITH LIKELY TO CATEGORICAL POPS FOR MUCH OF THE AREA UNDER THE
CURRENT HEADLINE WITH THE SHARP CUTOFF ON THE NORTHERN SIDE OF THE
PCPN AREA PERSISTING. WINDS WILL REMAIN RATHER STRONG THROUGH THE
DAY WITH BRISK NORTHWEST FLOW PERSISTING WITH DECENT PRESSURE
GRADIENT. EVENTUALLY...THE FORCING WILL BE DIMINISHING WITH THE
SNOW TAPERING TO FLURRIES BY LATER IN THE DAY. CLOUDINESS IS
EXPECTED TO PERSIST AS WELL IN CYCLONIC FLOW ON BACKSIDE INTO
WEDNESDAY NIGHT WITH AN APPROACHING SHORTWAVE ON THURSDAY AND
THURSDAY NIGHT HELPING THE CLOUDINESS TO MAINTAIN. IN FACT...SOME
WEAK LIFT WITH THIS PASSING WAVE ON FRIDAY MAY HELP TO PRODUCE SOME
FLURRIES IN SOUTHERN IOWA DURING THE DAY.
UPPER RIDGING WILL SLIDE THROUGH THE REGION INTO THE WEEKEND WITH
QUIET WEATHER DURING THIS TIME. TEMPERATURES WILL REMAIN BELOW
NORMAL WITH WIDESPREAD SNOW PACK AND ONLY WEAK ADVECTION UNTIL
SUNDAY NIGHT. THIS WARM ADVECTION IS IN ADVANCE OF THE NEXT SYSTEM
WHICH WILL PASS THROUGH THE REGION ON MONDAY INTO TUESDAY IN BROAD
NORTHWEST FLOW. BOTH GFS AND EURO HAVE INDICATED SOME DECENT
FORCING AND ANTICIPATE PCPN DEVELOPING AND SLIDING ACROSS THE STATE
ON MONDAY INTO EARLY TUESDAY. SOUNDINGS WOULD INDICATE GENERALLY
SNOW DURING THIS TIME ACROSS THE STATE WITH LIGHT TO MODERATE
ACCUMULATIONS EXPECTED.
&&
.AVIATION...26/18Z
AREAS OF LIGHT TO MODERATE SNOW WILL CONTINUE TO IMPACT THE
KDSM/KOTM/KALO AREAS THROUGH TONIGHT. A MIX OF MVFR TO IFR STRATUS
WILL ACCOMPANY THE SNOW. KFOD AND KMCW WILL HAVE LESS SNOW THOUGH
PERIODS OF MVFR STRATUS OR LOWER ARE POSSIBLE AT TIMES. GUSTY
NORTHERLY WINDS WILL PREVAIL THROUGH WEDNESDAY
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST WEDNESDAY FOR ADAIR-ADAMS-
APPANOOSE-BLACK HAWK-BOONE-CLARKE-DALLAS-DAVIS-DECATUR-GRUNDY-
HARDIN-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-
POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR AUDUBON-
BREMER-BUTLER-CASS-FRANKLIN-GREENE-GUTHRIE-HAMILTON.
&&
$$
UPDATE...DONAVON
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
332 AM EST WED FEB 27 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 428 PM EST TUE FEB 26 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PRONOUNCED SPLIT FLOW
CONTINUING ACROSS NAMERICA. IN WHAT HAS BEEN A VERY ACTIVE SRN
STREAM RECENTLY...A WELL-DEFINED MID LEVEL LOW IS MOVING ENE INTO
THE LWR OHIO VALLEY. SRN STREAM RIDGING AHEAD OF FEATURE EXTENDS
FROM JUST OFF THE SE COAST TO SRN NEW ENGLAND AND THEN BACK INTO THE
UPPER LAKES. WITH NRN STREAM WELL N OF HERE...ARCTIC AIR HAS
RETREATED INTO NRN CANADA. CLOSER TO HOME...PESKY STRATOCU HAS
CONTINUED TO PLAGUE UPPER MI TODAY. HOWEVER...ROUGHLY THE W THIRD OF
THE FCST AREA HAS ENJOYED MOSTLY SUNNY SKIES FOR AT LEAST A PORTION
OF THE DAY. THE POCKET OF MOSTLY SUNNY SKIES CURRENTLY OVER THE W IS
SHOWING SIGNS OF EXPANDING EASTWARD AS STRONGER DAYTIME HEATING
UNDER HIGHER LATE FEB SUN ANGLE IS WORKING ON LOWER ALBEDO FORESTED
TERRAIN TO RAISE MIXED LAYER AND THUS MIX OUT THE SHALLOW MOIST
LAYER.
DURING THE SHORT TERM...MAIN FCST ISSUE WILL REVOLVE AROUND
NORTHWARD PROGESS OF A WEAKENING PCPN SHIELD SPREADING N AROUND SRN
STREAM MID LEVEL LOW AS IT TRACKS INTO THE UPPER OHIO VALLEY/LWR
LAKES REGION. EARLY ON...LOW CLOUDS WILL CONTINUE TO PRESENT SOME
ISSUES. CLEARING MAY CONTINUE TO EXPAND E FROM WRN UPPER MI OVER THE
NEXT COUPLE OF HRS...BUT WITH LOSS OF DAYTIME HEATING...STRATOCU
WILL PROBABLY TEND TO SPREAD BACK INTO THE AREAS THAT HAVE
CLEARED...ESPECIALLY IF THE STRATOCU TO THE E AND NE DOES NOT BREAK
UP DURING THE LATE AFTN/EVENING. LATEST VIS SATELLITE IMAGERY DOES
SHOW STRATOCU THINNING OVER ERN LAKE SUPERIOR...SO THERE MAY YET BE
SOME MORE CLEARING DURING THE EVENING. WILL BE A TREND TO MONITOR.
WHILE CLOUDS WILL AGAIN MAKE OR BREAK TEMP FCST...THERE WILL LIKELY
NOT BE AS GREAT OF A TEMP SPREAD TONIGHT AS IN PREVIOUS NIGHTS BTWN
AREAS WITH CLOUDS AND AREAS WITH LESS CLOUD SINCE INCREASING
GRADIENT WINDS WILL LIMIT RADIATIONAL COOLING. TRENDED TEMPS TOWARD
RAW MODEL GUIDANCE WHICH PUTS MIN TEMPS GENERALLY IN THE MID/UPPER
20S.
AS FOR PCPN...THE STRONG ISENTROPIC ASCENT COMPONENT TO PCPN SHIELD
SPREADING N INTO SRN WI/SRN MI ATTM WILL GRADUALLY FADE WITH TIME AS
THE ZONE OF STRONG ASCENT TRANSLATES EASTWARD...RESULTING IN ZONE OF
HEAVIEST PCPN SHIFTING E TOWARD THE LWR LAKES/SRN NEW ENGLAND
TONIGHT/WED MORNING. THUS...A DECAYING SHIELD OF PCPN WILL BE
LIFTING TOWARD UPPER MI TONIGHT/WED MORNING. RECENT MODEL TRENDS
GENERALLY POINT TOWARD A MORE AGGRESSIVE PUSH OF LIGHT SNOW INTO
UPPER MI. GIVEN THE STRONG NORTHWARD PUSH OF PCPN THRU LWR MI ATTM
AND THE LACK OF A LAYER OF VERY DRY AIR AT THE LOWER LEVELS TO THE N
ACROSS UPPER MI...HAVE OPTED TO TREND PCPN CHC SLIGHTLY FARTHER N
THAN PREVIOUS FCST TO ROUGHLY A KERY/KSAW/KIMT LINE AND RAISED POPS
TO HIGH CHC ALONG LAKE MI. WITH 850MB TEMPS NO LWR THAN -8/-9C...
IT`S VERY UNLIKELY THAT ANY LES WILL DEVELOP OFF LAKE SUPERIOR UNDER
STRONG NE CYCLONIC FLOW WED. IF SHIELD OF LIGHT SYNOPTIC SNOW DOES
REACH LAKE SUPERIOR...THEN A LITTLE LAKE COMPONENT WILL BE THERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 331 AM EST WED FEB 27 2013
THURSDAY THROUGH FRIDAY...VERTICALLY STACKED SURFACE AND UPPER LEVEL
500MB CLOSED LOW LOCATED OVER THE LOWER GREAT LAKES THURSDAY MORNING
WILL SHIFT EASTWARD INTO THE NORTHEASTERN U.S. BY THURSDAY NIGHT. IT
DOES APPEAR AS THOUGH ENOUGH MOISTURE WILL REMAIN IN PLACE DURING
THIS TIME PERIOD TO KEEP LAKE EFFECT SNOW SHOWERS OVER AREAS FAVORED
BY A NORTH-NORTHEAST WIND. H850 TEMPERATURES ARE EXPECTED TO COOL TO
AROUND -10 TO -12C WHICH WOULD BE SUPPORTIVE OF LAKE EFFECT SNOW
SHOWERS AS LAKE TEMPERATURES ARE AVERAGING BETWEEN 1 AND 2C. AS
MENTIONED BY THE PREVIOUS SHIFT INVERSION HEIGHTS LOOK TO REMAIN
AROUND 3-4KFT...THIS COUPLED WITH A FAIRLY SHALLOW CLOUD LAYER WOULD
HELP TO LIMIT SNOW ACCUMULATION AS LITTLE IF ANY MOISTURE/LIFT IS
COLLOCATED WITH THE DGZ. LATE THURSDAY NIGHT SURFACE HIGH PRESSURE
WILL BUILD FROM JAMES BAY INTO THE UPPER GREAT LAKES. AT THE SAME
TIME A 500MB RIDGE WILL BUILD ACROSS THE AREA AS WELL. THE
COMBINATION OF WARMING ALOFT ALONG WITH DRY AIR FROM CANADA WRAPPING
IN FROM THE NORTH WILL HELP DIMINISH THE SNOW SHOWERS THROUGH THE
EARLY MORNING HOURS FRIDAY. THE REMAINDER OF FRIDAY LOOKS TO BE
DRY AT THIS POINT.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...THE SURFACE RIDGE AND DRY AIR
ARE PROGGED TO REMAIN IN PLACE OVER MUCH OF THE UPPER GREAT LAKES
REGION THROUGH THIS TIME PERIOD HELPING TO LIMIT PRECIPITATION
CHANCES. THE LACK OF MOISTURE WILL ALSO HELP TO KEEP SKIES PARTLY
CLOUDY TO MOSTLY CLEAR THROUGH THIS TIME FRAME AS WELL. TEMPERATURES
ARE EXPECTED TO BE NEAR TO SLIGHTLY BELOW NORMAL THROUGH THIS TIME
PERIOD AS H850 TEMPS ARE EXPECTED TO BE BETWEEN -12C AND -14C.
MONDAY THROUGH TUESDAY NIGHT...UPPER LEVEL 500MB TROUGH IS EXPECTED
TO REMAIN IN PLACE OVER MUCH OF THE EASTERN SEABOARD THROUGH THIS
TIME PERIOD AS SHOWN BY THE 00Z GFS/EC/GEM. MONDAY MORNING A LOW
PRESSURE SYSTEMS IS PROGGED TO DEVELOP OVER THE CENTRAL PLAINS AT
THE SAME TIME THAT AN UPPER LEVEL 500MB TROUGH DIGS INTO THE PLAINS.
MODELS ARE IN GENERAL AGREEMENT THAT THE LOW WILL REMAIN SOUTH OF
THE UPPER PENINSULA AS THE SURFACE HIGH PRESSURE SYSTEM REMAINS IN
PLACE OVER MUCH OF THE UPPER MIDWEST...SHIFTING SLIGHTLY WEST MONDAY
NIGHT INTO TUESDAY MORNING. THE 00Z GFS/EC ALONG WITH THE GFS
ENSEMBLE MEMBERS KEEP THE LOW SOUTH OF THE AREA...WITH THE LOW
PASSING ALONG OR JUST NORTH OF THE AR/MO BORDER. MODELS ALSO
INDICATED COLDER AIR AT H850 SHIFTING INTO THE REGION WITH WINDS OUT
OF THE NORTH. H850 TEMPS ARE PROGGED TO BE BETWEEN -10 AND -13C
WHILE MOISTURE BETWEEN 1000-850MB IS EXPECTED TO INCREASE. THIS
SHOULD ALLOW LAKE EFFECT SNOW SHOWERS TO DEVELOP OVER NORTH WIND
FAVORED SNOW BELTS. DECIDED TO MENTION ONLY SLIGHT CHANCES MONDAY
NIGHT INTO TUESDAY AS THIS IS STILL SEVERAL DAYS OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1201 AM EST WED FEB 27 2013
MOIST NE FLOW SHOULD GENERALLY MAINTAIN MVFR CLOUDS THROUGH PD AT
ALL TAF SITES. DOWNSLOPING FLOW AT KCMX COULD PERHAPS LEAD TO BRIEF
BREAKS IN CLOUDS THERE...BUT OTHERWISE INCREASINGLY MOIST NE FLOW
SHOULD ENSURE LOW CLOUDS THROUGH FCST PD. KSAW COULD SEE SOME
AFTERNOON FLURRIES FROM DEEPER MOISTURE WRAPPING BACK INTO AREA FROM
SYSTEM LIFTING THROUGH LOWER LAKES. TIGHTENING PRES GRAD WILL ALLOW
NE WINDS TO GUST NEAR 25 KTS BY LATE WED MORNING/EARLY
AFTERNOON...ESPECIALLY AT KSAW
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 428 PM EST TUE FEB 26 2013
TIGHTENING PRES GRADIENT BTWN HIGH PRES TO THE N AND NW AND LOW PRES
TRACKING THRU THE LWR OHIO VALLEY TO LWR LAKES WILL RESULT IN
NORTHEASTERLY WINDS ACROSS LAKE SUPERIOR INCREASING TO 20-30KT
TONIGHT THRU WED. MIGHT SEE A FEW GALE FORCE GUSTS WED AFTN OVER THE
E HALF. EVEN THOUGH THE LOW CONTINUES TO MOVE E THU...THE HIGH
BUILDING TOWARD THE AREA FROM N WILL MAINTAIN A TIGHT PRES
GRADIENT...RESULTING IN CONTINUED 20-30KT WINDS WITH SOME GALE FORCE
GUSTS POSSIBLE OVER THE E HALF THRU THU MORNING. WINDS WILL THEN
VERY SLOWLY DIMINISH FROM W TO E FRI/SAT AS THE HIGH PRES MOVES
CLOSER...BUT IT WILL PROBABLY BE SAT BEFORE WINDS DROP BLO 20KT
ACROSS THE ENTIRE LAKE. THE PERIOD OF STRONG WINDS WED NIGHT THRU
FRI WILL ALSO BRING THE POTENTIAL FOR FREEZING SPRAY. LIGHT WINDS
UNDER 10KT ARE EXPECTED SUN AS SFC HIGH PRES RIDGE WILL EXTEND FROM
HUDSON BAY S ACROSS LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST THURSDAY FOR
LSZ244-245-248>250-264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1202 AM EST WED FEB 27 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 428 PM EST TUE FEB 26 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PRONOUNCED SPLIT FLOW
CONTINUING ACROSS NAMERICA. IN WHAT HAS BEEN A VERY ACTIVE SRN
STREAM RECENTLY...A WELL-DEFINED MID LEVEL LOW IS MOVING ENE INTO
THE LWR OHIO VALLEY. SRN STREAM RIDGING AHEAD OF FEATURE EXTENDS
FROM JUST OFF THE SE COAST TO SRN NEW ENGLAND AND THEN BACK INTO THE
UPPER LAKES. WITH NRN STREAM WELL N OF HERE...ARCTIC AIR HAS
RETREATED INTO NRN CANADA. CLOSER TO HOME...PESKY STRATOCU HAS
CONTINUED TO PLAGUE UPPER MI TODAY. HOWEVER...ROUGHLY THE W THIRD OF
THE FCST AREA HAS ENJOYED MOSTLY SUNNY SKIES FOR AT LEAST A PORTION
OF THE DAY. THE POCKET OF MOSTLY SUNNY SKIES CURRENTLY OVER THE W IS
SHOWING SIGNS OF EXPANDING EASTWARD AS STRONGER DAYTIME HEATING
UNDER HIGHER LATE FEB SUN ANGLE IS WORKING ON LOWER ALBEDO FORESTED
TERRAIN TO RAISE MIXED LAYER AND THUS MIX OUT THE SHALLOW MOIST
LAYER.
DURING THE SHORT TERM...MAIN FCST ISSUE WILL REVOLVE AROUND
NORTHWARD PROGESS OF A WEAKENING PCPN SHIELD SPREADING N AROUND SRN
STREAM MID LEVEL LOW AS IT TRACKS INTO THE UPPER OHIO VALLEY/LWR
LAKES REGION. EARLY ON...LOW CLOUDS WILL CONTINUE TO PRESENT SOME
ISSUES. CLEARING MAY CONTINUE TO EXPAND E FROM WRN UPPER MI OVER THE
NEXT COUPLE OF HRS...BUT WITH LOSS OF DAYTIME HEATING...STRATOCU
WILL PROBABLY TEND TO SPREAD BACK INTO THE AREAS THAT HAVE
CLEARED...ESPECIALLY IF THE STRATOCU TO THE E AND NE DOES NOT BREAK
UP DURING THE LATE AFTN/EVENING. LATEST VIS SATELLITE IMAGERY DOES
SHOW STRATOCU THINNING OVER ERN LAKE SUPERIOR...SO THERE MAY YET BE
SOME MORE CLEARING DURING THE EVENING. WILL BE A TREND TO MONITOR.
WHILE CLOUDS WILL AGAIN MAKE OR BREAK TEMP FCST...THERE WILL LIKELY
NOT BE AS GREAT OF A TEMP SPREAD TONIGHT AS IN PREVIOUS NIGHTS BTWN
AREAS WITH CLOUDS AND AREAS WITH LESS CLOUD SINCE INCREASING
GRADIENT WINDS WILL LIMIT RADIATIONAL COOLING. TRENDED TEMPS TOWARD
RAW MODEL GUIDANCE WHICH PUTS MIN TEMPS GENERALLY IN THE MID/UPPER
20S.
AS FOR PCPN...THE STRONG ISENTROPIC ASCENT COMPONENT TO PCPN SHIELD
SPREADING N INTO SRN WI/SRN MI ATTM WILL GRADUALLY FADE WITH TIME AS
THE ZONE OF STRONG ASCENT TRANSLATES EASTWARD...RESULTING IN ZONE OF
HEAVIEST PCPN SHIFTING E TOWARD THE LWR LAKES/SRN NEW ENGLAND
TONIGHT/WED MORNING. THUS...A DECAYING SHIELD OF PCPN WILL BE
LIFTING TOWARD UPPER MI TONIGHT/WED MORNING. RECENT MODEL TRENDS
GENERALLY POINT TOWARD A MORE AGGRESSIVE PUSH OF LIGHT SNOW INTO
UPPER MI. GIVEN THE STRONG NORTHWARD PUSH OF PCPN THRU LWR MI ATTM
AND THE LACK OF A LAYER OF VERY DRY AIR AT THE LOWER LEVELS TO THE N
ACROSS UPPER MI...HAVE OPTED TO TREND PCPN CHC SLIGHTLY FARTHER N
THAN PREVIOUS FCST TO ROUGHLY A KERY/KSAW/KIMT LINE AND RAISED POPS
TO HIGH CHC ALONG LAKE MI. WITH 850MB TEMPS NO LWR THAN -8/-9C...
IT`S VERY UNLIKELY THAT ANY LES WILL DEVELOP OFF LAKE SUPERIOR UNDER
STRONG NE CYCLONIC FLOW WED. IF SHIELD OF LIGHT SYNOPTIC SNOW DOES
REACH LAKE SUPERIOR...THEN A LITTLE LAKE COMPONENT WILL BE THERE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 428 PM EST TUE FEB 26 2013
LITTLE CHANGES TO THE LONG TERM FROM 24 HOURS AGO...WITH THE
MAIN ITEM OF DIFFERENCE A SLIGHT WOBBLE TO THE NORTHWEST WITH THE
SYSTEM CURRENTLY MOVING THROUGH THE MID MISSISSIPPI VALLEY THAT
WILL MOVE THROUGH THE LOWER GREAT LAKES. THIS SLIGHT
ADJUSTMENT...PUSHES THE PRECIPITATION A TOUCH FARTHER INLAND FROM
LAKE MICHIGAN. BUT AS THE LONG TERM PERIOD BEGINS...THE LOW WILL
START IT/S EASTWARD SHIFT TOWARDS NEW YORK AND DIMINISH THE SNOW
ALONG THE LAKE MICHIGAN SHORELINE.
ATTENTION THEN TURNS TO THE AMOUNT OF MOISTURE AND COLD AIR IN THE
LOWER LEVELS TO SUPPORT LAKE ENHANCED AND UPSLOPE SNOW SHOWERS.
LATEST TRENDS IN THE MOISTURE AND COLD AIR /850MB TEMPERATURES
FALLING FROM -9C AT WEDNESDAY NIGHT TO -13C BETWEEN 900-850MB BY
THURSDAY AFTERNOON/ LEADS TO GREATER CONFIDENCE IN SCATTERED SNOW
SHOWERS OCCURRING FOR LOCATIONS NEAR LAKE SUPERIOR FROM PICTURED
ROCKS AND WESTWARD. INVERSION HEIGHTS AROUND 3-4KFT SHOULD KEEP THE
INTENSITY IN CHECK AND HELPS KEEP LAKE INDUCED CAPES BELOW 200
J/KG. THUS...WILL BUMP POPS UP 5-10 PERCENT INTO HIGHER END CHANCE
CATEGORY. SNOWFALL AMOUNTS SHOULD BE FAIRLY LIGHT...SINCE CLOUD
DEPTH IS FAIRLY LIMITED. WITH THE INITIAL CLOUD LAYER MAINLY BEING
BELOW THE DGZ WEDNESDAY NIGHT...WOULD EXPECT FLAKES TO BE FAIRLY
SMALL. BUT AS THE COLDER AIR ARRIVES...IT DOES ATTEMPT TO PUSH THE
CLOUD LAYER INTO THE DGZ AND HELP SNOW RATIOS. BUT WITH THE LIMITED
CLOUD DEPTH/MOISTURE TO WORK WITH...WOULDN/T EXPECT MUCH MORE THAN
AN INCH OR TWO OF TOTAL ACCUMULATION BY THE TIME IT STARTS WINDING
DOWN ON FRIDAY. THE HIGHEST AMOUNTS WILL BE IN THE FAVORED UPSLOPE
LOCATIONS WITH NORTHEAST WINDS...ESPECIALLY IN/NEAR THE HURON
MOUNTAINS WHICH COULD APPROACH 3 INCHES.
A BUILDING CANADIAN HIGH OVER HUDSON BAY WILL SLIDE A RIDGE SOUTH
INTO THE UPPER GREAT LAKES REGION FRIDAY AND IT WILL REMAIN INTO THE
FIRST PART OF THE NEXT WEEK. THIS WILL WORK TO REDUCE THE INVERSION
HEIGHTS TO 2KFT AND SHOULD BRING AN END TO THE LAKE ENHANCED/EFFECT
BY FRIDAY NIGHT. WILL GO WITH PARTLY CLOUDY SKIES THROUGH THE
WEEKEND...BUT THERE IS SOME CONCERN THAT THERE COULD BE LINGERING
LOW CLOUDS BELOW THE STRENGTHENING INVERSION DURING THAT TIME.
MAIN QUESTION FOR NEXT WEEK WILL BE THE LOCATION OF A SHORTWAVE
CUTTING THROUGH THE UPPER RIDGE OVER THE WESTERN CONUS AND IT/S
INFLUENCE ON THE UPPER TROUGH ON THE EAST COAST. 00Z ECMWF HOLDS
THE TROUGH OVER THE AREA...WHILE THE GFS TRIES TO PUSH THE RIDGE
OVER THE AREA ON MONDAY. THIS HAS THE POTENTIAL FOR WEAKENING THE
SURFACE RIDGE AND PUSHING SOME PRECIPITATION INTO THE AREA ON THE
EAST SIDE OF A LOW MOVING THROUGH CENTRAL PLAINS OR UPPER
MISSISSIPPI VALLEY. WILL RESPECT THE CONSISTENCY SHOWN IN THE ECMWF
OVER THE LAST SEVERAL DAYS AND TRY TO KEEP MUCH OF THE AREA DRY.
HIGH TEMPERATURES ARE STILL LOOKING TO BE BELOW NORMAL THROUGH THE
LONG TERM PERIOD. LOOKING AT THE LONGER RANGE FORECASTS /EVEN THOUGH
SKILL IS FAIRLY LIMITED/...NOT TOO MANY SIGNS OF SPRING FOR THE
FIRST WEEK OR TWO OF MARCH. GFS/ECMWF ENS MEANS ARE SHOWING 850MB
TEMPS BELOW NORMAL THROUGH THE FIRST WEEK AND GFS ENS 500MB MEAN
HEIGHTS ARE SHOWING A TROUGH REMAINING OVER THE EASTERN CONUS
THROUGH THE MIDDLE OF MARCH. AFTER BEING SPOILED BY WARM
MARCH WEATHER IN 2010/2012...ITS LOOKING LIKE MARCH WILL
BE MORE TRADITIONAL TEMPERATURE WISE. UNFORTUNATELY FOR SOME OF THE
LOCATIONS OF CENTRAL UPPER MICHIGAN THAT HAVE SEEN PROLONGED
DRYNESS...THIS PATTERN WON/T BE SUPPORTIVE OF ANY SIGNIFICANT
PRECIPITATION AND MAINLY JUST LIGHT PRECIPITATION FROM CLIPPERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1201 AM EST WED FEB 27 2013
MOIST NE FLOW SHOULD GENERALLY MAINTAIN MVFR CLOUDS THROUGH PD AT
ALL TAF SITES. DOWNSLOPING FLOW AT KCMX COULD PERHAPS LEAD TO BRIEF
BREAKS IN CLOUDS THERE...BUT OTHERWISE INCREASINGLY MOIST NE FLOW
SHOULD ENSURE LOW CLOUDS THROUGH FCST PD. KSAW COULD SEE SOME
AFTERNOON FLURRIES FROM DEEPER MOISTURE WRAPPING BACK INTO AREA FROM
SYSTEM LIFTING THROUGH LOWER LAKES. TIGHTENING PRES GRAD WILL ALLOW
NE WINDS TO GUST NEAR 25 KTS BY LATE WED MORNING/EARLY
AFTERNOON...ESPECIALLY AT KSAW
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 428 PM EST TUE FEB 26 2013
TIGHTENING PRES GRADIENT BTWN HIGH PRES TO THE N AND NW AND LOW PRES
TRACKING THRU THE LWR OHIO VALLEY TO LWR LAKES WILL RESULT IN
NORTHEASTERLY WINDS ACROSS LAKE SUPERIOR INCREASING TO 20-30KT
TONIGHT THRU WED. MIGHT SEE A FEW GALE FORCE GUSTS WED AFTN OVER THE
E HALF. EVEN THOUGH THE LOW CONTINUES TO MOVE E THU...THE HIGH
BUILDING TOWARD THE AREA FROM N WILL MAINTAIN A TIGHT PRES
GRADIENT...RESULTING IN CONTINUED 20-30KT WINDS WITH SOME GALE FORCE
GUSTS POSSIBLE OVER THE E HALF THRU THU MORNING. WINDS WILL THEN
VERY SLOWLY DIMINISH FROM W TO E FRI/SAT AS THE HIGH PRES MOVES
CLOSER...BUT IT WILL PROBABLY BE SAT BEFORE WINDS DROP BLO 20KT
ACROSS THE ENTIRE LAKE. THE PERIOD OF STRONG WINDS WED NIGHT THRU
FRI WILL ALSO BRING THE POTENTIAL FOR FREEZING SPRAY. LIGHT WINDS
UNDER 10KT ARE EXPECTED SUN AS SFC HIGH PRES RIDGE WILL EXTEND FROM
HUDSON BAY S ACROSS LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1144 PM CST TUE FEB 26 2013
.AVIATION... /06Z TAF ISSUANCE/
LIFR OR LOWER CONDITIONS SHOULD REMAIN JUST WEST OF KAXN AND KRWF
OVERNIGHT AS DRIER AIR LOW LEVEL AIR CONTINUES TO STREAM IN FROM
THE NORTHEAST. VISIBILITIES BETWEEN 2 AND 4SM IN BR WILL BE
COMMON. MVFR CEILINGS (BKN-OVC020-025) HAVE SPREAD ACROSS KEAU
FROM THE EAST AND WILL SOON REACH KRNH AND KMSP BY 09Z. SHORT TERM
GUIDANCE SUGGESTS THAT THIS WILL LAST THROUGH THE DAY AND THE
UPCOMING NIGHT WITH A SMALL CHANCE FOR VFR LATE WEDNESDAY
AFTERNOON AND EARLY EVENING. HOWEVER...CONFIDENCE IS NOT HIGH
ENOUGH TO STRAY FROM MVFR ATTM. THERE WILL ALSO BE SOME LIGHT SNOW
AT KEAU WEDNESDAY MORNING AND EARLY AFTERNOON. THE BEST PERIOD FOR
SMALL ACCUMULATIONS LOOKS TO BE BETWEEN 14Z AND 20Z. SOME SNOW
SHOWERS COULD REACH KRNH. ALL SITES EXPECTED TO BE AOB 030
WEDNESDAY NIGHT WITH KAXN AOB 010. NORTHERLY WINDS OVERNIGHT NEAR
10 KNOTS INCREASING TO 12-15 KNOTS WITH GUSTS TO 22-25 KNOTS ON
WEDNESDAY.
KMSP...MVFR CEILINGS CURRENTLY ABOUT 50 MILES EAST OF THE
AIRFIELD. ITS DIFFICULT TO CALCULATE THEIR WESTWARD SPEED DUE TO
THE EXTENSIVE HIGH LEVEL OVERCAST ACROSS THE REGION. A ROUGH
ESTIMATE IS 25 KTS WHICH WOULD BRING THE CEILINGS IN BEFORE 07Z.
CHANCES ARE PRETTY HIGH THAT THE MVFR CEILINGS WILL CONTINUE
THROUGH THE TAF PERIOD ALTHOUGH THERE IS A SMALL CHANCE FOR
IMPROVEMENT WEDNESDAY AFTERNOON/EVENING AS THE LOW LEVEL NE FLOW
OFF OF LAKE SUPERIOR ENDS AND BECOMES MORE NORTHERLY. CHANCES THEN
INCREASE AGAIN FOR MVFR CEILINGS OVERNIGHT AND THURSDAY MORNING AS
A TROUGH OF LOW PRESSURE DROPS SOUTH ACROSS THE REGION.
/OUTLOOK FOR KMSP/
THU...MVFR CIGS. N WIND 10 KTS.
FRI...VFR WITH MVFR CIGS POSSIBLE. N WIND 5-10 KTS.
SAT...VFR. N WIND 5 KTS.
&&
.DISCUSSION... /ISSUED AT 233 PM CST TUE FEB 26 2013/
INITIAL CONCERN IS CLOUD COVER OVERNIGHT. DRIER WEDGE IN LOWER
LEVEL CIRCULATING AROUND STORM TO THE SOUTH WAS STRONG ENOUGH THIS
AFTERNOON TO ERODE CLOUDS SOME. ANOTHER SURGE OF MOISTURE APPEARS
TO BE WORKING ACROSS THE UP AND NORTHEAST WI AND IS NOW MOVING
ACROSS WEST CENTRAL WI. LATEST RAP HAS THIS WORKING SOUTHWEST LATE
AFTERNOON INTO THE EVENING...AFFECTING MAINLY SOUTH CENTRAL MN.
STRATUS AND FOG IS NOW ERODING FROM THE NORTH AS WELL...IN DRIER
AIR FLOW OVER NORTHEAST MN. DIFFICULT TO DISCERN HOW FAR SOUTH AND
WEST THIS WILL GO. MODELS TREND MUCH DRIER IN THE 925-850MB LAYER
OVER THE WESTERN AREAS. STILL BELIEVE SIGNIFICANT AMOUNT OF
MID/HIGH CLOUDS WILL CONTINUE TO STREAM NORTH AND WEST OVER NIGHT
AND SHOULD MAINTAIN AT LEAST A MOSTLY CLOUDY SKY OVER MOST OF THE
AREA. FOG SHOULD BE LIMITED TO THE FAR WEST INTO THE EVENING...AND
SHOULDNT BECOME DENSE OR AS WIDESPREAD WITH THE GRADIENT
INCREASING AS WELL AS THE SURFACE WINDS OVERNIGHT.
CONCERN NUMBER TWO REMAINS HOW FAR NORTHWEST SNOW WILL DEVELOP
MAINLY DURING THE DAY WEDNESDAY. MODELS FAIRLY CONSISTENT ON
DRAGGING SNOW INTO FAR SOUTHEAST CWA...WITH THE NAM REMAINING THE
DRIEST. THE GFS IS FARTHER WEST INTO OUR CWA...WITH THE 12Z GEM
AND ECMWF CONFINING POSSIBILITY TO THE FAR SOUTHEAST CORNER OF THE
AREA. IT ALL HINGES ON HOW THE SECONDARY UPPER TROUGH MOVES ACROSS
KANSAS AND MERGES WITH THE UPPER LOW MOVING OVER THE OHIO RIVER
RIVER VALLEY. WILL CONTINUE THE TREND OF LOW END CHANCE POPS OVER
THAT REGION THROUGH WEDNESDAY.
SHOULD SEE SOME CLEARING INTO WEDNESDAY NIGHT FOLLOWING THE STORM
SYSTEM TO THE SOUTHEAST...BUT MODELS TREND ANOTHER SHORT WAVE
DROPPING SOUTHEAST OVER THE DAKOTAS AND MINNESOTA...THURSDAY INTO
FRIDAY. THIS SHOULD YIELD AT LEAST MORE CLOUDS AND THE THREAT OF
SOME FLURRIES...MAINLY OVER THE WESTERN AREAS. THE 12Z ECMWF IS
NOT AS AMPLIFIED WITH THIS FEATURE AND IS A BIT DRIER...SO WILL
LEAVE FLURRY MENTION OUT FOR NOW.
HIGH TEMPERATURES FORECAST SLIGHTLY BELOW NORMAL INTO THE
WEEKEND. NEXT STRONG TROUGH MOVES ASHORE ON THE WEST COAST OVER
THE WEEKEND. LONGER TERM MODELS BRINGING THIS NEXT WAVE/TROUGH
INTO THE AREA MAINLY SUNDAY NIGHT INTO TUESDAY. HAVE INCLUDED
SMALL CHANCE POPS FOR THIS FEATURE AS IT MOVES THROUGH THE AREA
FOR NOW. COULD BE WARM ENOUGH FOR A POSSIBLY MIX AS THE SYSTEM
WORKS INTO THE AREA...AT LEAST INITIALLY.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/DWE
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML.
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1102 PM CST TUE FEB 26 2013
.UPDATE...
ADDED FOND DU LAC AND WASHINGTON COUNTIES TO WARNING AS PERSISTENT
SNOW BAND LINGERS WITH CALLS TO THE SHERIFF DEPARTMENTS INDICATING
THE FALLING SNOW AND GUSTY WINDS WERE MAKING ROADS NEARLY
IMPASSIBLE IN EASTERN FOND DU LAC COUNTY AND NORTHERN WASHINGTON.
HEAVIER SNOW BANDS NOT MAKING A LOT OF PROGRESS TO THE WEST AS
DRIER AIR...MARKED BY LOWER DEW POINTS...IS NOSING INTO NW
PORTIONS OF THE FORECAST AREA.
ALSO WATCHING THE FIRST OF NUMEROUS SNOW SHOWERS MOVING ONSHORE
OVER EXTREME NE IL/SE WI. WAUKEGAN IL DOWN TO 3/4 MILE...OR 1/2
INCH/HOUR SNOW RATE...WITH THIS LEAD SNOW SHOWER BAND.
&&
.AVIATION/06Z TAFS/...
WILL LIKELY KEEP TAF SITES AT IFR LEVELS...ESPECIALLY CIGS...THROUGH
THE FORECAST PERIOD ...THOUGH GFS GUIDANCE INDICATES KMSN MAY
IMPROVE TO MVFR EARLY WEDNESDAY EVENING IN SUBSIDENCE BEHIND
SPOKE OF VORTICITY ROTATING AROUND UPPER LOW. EXPECT STEADY
ACCUMULATING SNOW TO BECOME MORE OCCASIONAL THROUGH THE OVERNIGHT
AS FORM OF PRECIPITATION TURNS TO SNOW SHOWERS...WITH BREAKS
BETWEEN CELLS. NORTHEAST WINDS WILL TURN NORTH BUT REMAIN
GUSTY...WITH THE STRONGEST WINDS AT KMKE AND KENW...EASING SLOWLY
TO THE WEST AT KUES AND KMSN.
&&
.MARINE...
WILL BE EXTENDING GALE WARNING UNTIL 09Z AS BOTH RAP AND NAM
SOUNDINGS TAP 37 KNOT+ WINDS UNTIL AT LEAST 08Z. NOT SEEING GALE
GUSTS AT SOUTHERN LOCATIONS AT THIS TIME...BUT GRADIENT WILL
TIGHTEN FOR A TIME AS LOW LIFTS TOWARD SRN LOWER MICHIGAN AND
WINDS BECOME NORTH.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WARNING UNTIL NOON CST WEDNESDAY FOR WIZ051-052-059-
060-066-070>072.
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ058-
062>065-067>069.
LM...GALE WARNING UNTIL 3 AM CST WEDNESDAY FOR LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/WEDNESDAY AND AVIATION/MARINE...MEB
WEDNESDAY NIGHT THROUGH TUESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
324 AM MST WED FEB 27 2013
.SHORT TERM...VALID FOR TDY AND THU...
A COUPLE OF DYNAMICALLY-WEAK AND MOISTURE-STARVED WAVES ARE HEADED
OUR WAY THE NEXT TWO DAYS...BUT IMPACTS WITH THEM APPEAR MINIMAL.
TODAY...STRATUS BUILT SOUTHEAST INTO MILES CITY AND BAKER BEHIND A
WEAK COLD FRONT OVERNIGHT...SO A PRIMARY FORECAST CONSIDERATION IS
WHEN IT WILL BREAK UP. RAP-BASED SOLUTIONS HOLD THE STRATUS ACROSS
MUCH OF SOUTHEASTERN MT THROUGH THE DAY...WHICH KEEPS HIGHS IN THE
LOWER 30S F EVEN FOR MILES CITY IN THOSE MODEL SIMULATIONS. HAVING
SAID THAT...THE PLANETARY BOUNDARY LAYER PARAMETERIZATION THAT THE
RAP USES IS KNOWN TO BE TOO SLOW IN ERODING STRATUS...SO THAT IDEA
IS PROBABLY THE WORST-CASE SCENARIO. RECENT HRRR RUNS SEEM TO HAVE
A BETTER HANDLE ON THE STRATUS...TAKING IT OUT OF MILES CITY PRIOR
TO 18 UTC...AND LINGERING IT INTO THE AFTERNOON ONLY AROUND BAKER.
WE THUS REDUCED HIGHS INTO THE MID 30S F AT BAKER...BUT DECIDED TO
LEAVE THEM ALONE OVER THE REST OF SOUTHEASTERN MT. HIGHS OVER MOST
OF THE AREA ARE IN LINE WITH THE 00 UTC BIAS-CORRECTED MULTI-MODEL
CONSENSUS...WHICH SUPPORTS READINGS OF 40 TO 45 F AGAIN TODAY WITH
BARE GROUND HELPING OUT WARMING DESPITE MODEST MIXING.
TONIGHT...A WEAK 500-HPA SHORT WAVE TROUGH WILL CROSS THE AREA. WE
LEFT LOW-END POPS IN PLAY FOR CONTINUITY/S SAKE AND OUT OF RESPECT
TO THE 00 UTC GFS...WHICH DOES SIMULATE SOME SHOWERS. THE GFS IDEA
IS ADMITTEDLY A BIT OF AN OUTLIER THOUGH. OTHERWISE...WINDS SHOULD
INCREASE AT BOTH LIVINGSTON AND BIG TIMBER AS THE SURFACE GRADIENT
TIGHTENS WITH THE PASSAGE OF THE SHORT WAVE. IF THE GFS DOES PROVE
CORRECT...WE MAY ACTUALLY NEED TO FURTHER INCREASE WIND SPEEDS FOR
BIG TIMBER. FORECAST LOWS TONIGHT ARE BASED ALMOST ENTIRELY ON THE
00 UTC BIAS-CORRECTED GFS GRIDDED MOS OUTPUT...WHICH HAS PERFORMED
MUCH BETTER THAN MOST COLD-BIASED LOW TEMPERATURE GUIDANCE LATELY.
THU...WEAK COLD AIR ADVECTION ALOFT WILL YIELD MIXING UP TO AROUND
750 HPA IN MOST AREAS...WHICH WILL COMBINE WITH DOWNSLOPE WINDS IN
THE BOUNDARY LAYER TO PROMOTE ANOTHER SEASONABLY MILD DAY. THE GFS
AND WRF-BASED SOLUTIONS LIKE THE NAM AND SREF ARE AT ODDS WITH THE
NEXT WEAK 500-HPA SHORT WAVE...WITH THE LATTER MODELS SUPPORTING A
LOW-END SHOWER CHANCE AGAIN...ESPECIALLY BY THU EVENING. GIVEN THE
MODEL SPREAD...WE CHOSE TO LEAVE OUR MAINLY DRY FORECAST ALONE FOR
NOW. THAT ALSO SERVES TO LIMIT THE NUMBER OF PERIODS CONTAINING 20
OR 30 PERCENT POPS IN WHAT IS GENERALLY A BENIGN PATTERN. SCHULTZ
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
MODELS HAVING TROUBLE RESOLVING SMALLER FEATURES THROUGH THE
EXTENDED SO HAVE KEPT A BROADBRUSH APPROACH GOING WITH THIS
PACKAGE. MODELS ARE IN AGREEMENT WITH STRONG UPPER RIDGE
DEVELOPING FOR LATE THURSDAY INTO SUNDAY. DEEP TROF IN THE EASTERN
U.S. WILL BLOCK FLOW ACROSS THE REGION...ESPECIALLY THE NORTHERN
JET STREAM...RESULTING IN RIDGE DEVELOPMENT OVER THE AREA LATE
WEEK INTO THE WEEKEND. 850 TEMPERATURES PUSH DOUBLE DIGITS BY
FRIDAY INTO SATURDAY FOR HIGHS IN THE 50S TO LOWER 60S. THERE IS A
GOOD MOISTURE STREAM OVER RIDING THE RIDGE SO EXPECT A GOOD DEAL
OF MID AND HIGH CLOUD COVER AND A FEW SNOW SHOWERS FOR MOUNTAIN
AREAS. MODEL SPECTRUM DOES SHOW A VERY LARGE SPREAD FOR
TEMPERATURES FRIDAY INTO SATURDAY DUE TO A FEW MODEL SOLUTIONS
HOLDING ONTO COLDER SOLUTION FROM THE PAST FEW DAYS. LATEST RUNS
SEEM SOLIDLY IN THE WARM SIDE OF GUIDANCE AND RECENT MODEL
SOLUTIONS HAVE TRENDED TOO COLD BY 5 TO 10 DEGREES THUS PUSHED CURRENT
FORECAST TOWARD THE HIGH END OF GUIDANCE.
SUNDAY INTO WEDNESDAY LOOKS UNSETTLED AS SEVERAL PACIFIC SYSTEMS
TRY TO BUILD INTO THE AREA. BLOCKING BY DEEP TROF OVER THE EASTERN
U.S. WILL CONTINUE TO PRESENT A PROBLEM FOR EASTERLY MOVEMENT AND
HAVE SEEN MODELS JUMP AROUND FROM SOLUTIONS THAT SIT THESE PACIFIC
DISTURBANCES OVER THE AREA FOR A DAY OR TWO TO OTHER SOLUTIONS
THAT MOVE SYSTEMS IN FROM THE WEST THEN DEFLECT THEM SOUTHWARD
INTO WYOMING AND COLORADO. MODELS BRING THE FIRST OF THE SYSTEMS
INTO THE AREA SUNDAY AFTERNOON...BUT THIS MAY BE A BIT FAST GIVEN
UPSTREAM BLOCK. KEPT TEMPERATURES ON THE WARM END SUNDAY BUT DID
ADD MENTION OF CHANCE POPS TO WESTERN HALF OF FORECAST AREA.
MONDAY INTO WEDNESDAY LOOK UNSETTLED WITH BROADBRUSH 30 AND 40
POPS FOR LOWER ELEVATIONS AND LIKELY POPS FOR THE MOUNTAINS ON
MONDAY...AND CLIMO TYPE POPS AND TEMPERATURES FOR TUESDAY INTO
WEDNESDAY BASED ON MODEL INCONSISTENCY. CHAMBERS
&&
.AVIATION...
MVFR CEILINGS WILL PERSIST THIS MORNING EAST OF ROSEBUD
COUNTY INCLUDING KMLS AND KBHK...SLOWLY CLEARING FROM WEST TO
EAST THIS AFTERNOON. OTHERWISE VFR CONDITIONS WILL PREVAIL TODAY.
A WEAK DISTURBANCE WILL BRING ISOLATED RAIN/SNOW SHOWERS TO THE
AREA THIS AFTERNOON INTO TONIGHT. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 043 027/044 028/051 036/058 039/046 037/040 025/043
0/B 21/B 11/B 00/U 12/W 53/J 11/B
LVM 039 024/040 028/044 032/052 035/043 031/036 022/041
1/N 22/W 12/J 00/B 14/W 43/J 22/J
HDN 042 024/042 024/048 032/056 036/052 038/039 026/042
0/U 21/B 10/B 00/U 12/W 54/J 11/B
MLS 044 028/046 030/049 036/056 038/055 038/038 028/041
1/B 21/B 10/B 00/B 11/B 44/J 21/E
4BQ 040 023/040 026/046 034/054 035/052 037/038 027/041
0/B 22/J 10/B 00/B 02/W 44/J 31/E
BHK 034 023/039 024/044 033/051 036/050 033/034 025/035
1/E 12/W 11/B 00/B 01/B 44/J 31/E
SHR 036 013/037 018/042 028/052 029/051 026/035 020/039
0/U 11/B 11/B 10/U 02/W 53/J 21/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
530 AM CST WED FEB 27 2013
.DISCUSSION.../ISSUED AT 308 AM CST/
A MOSTLY CLOUDY AND BREEZY DAY IS IN STORE FOR THE AREA. LOW CLOUDS
SEEM TO BE BREAKING UP OVER MUCH OF THE AREA...BUT MID AND HIGH
CLOUDS WILL REMAIN ABUNDANT. NORTHWESTERLY WINDS WILL INCREASE
THROUGH THE DAY...WITH GUSTS AROUND 30 MPH THIS AFTERNOON. STRONGEST
WINDS ARE ANTICIPATED ALONG THE MISSOURI RIVER...AND ACROSS PORTIONS
OF NORTHWEST IOWA AND SOUTHWEST MINNESOTA...WHERE WE COULD SEE GUSTS
UP TO 35 MPH. HIGHS WILL CONTINUE TO RUN A FEW DEGREES BELOW
NORMAL...WITH READINGS MAINLY IN THE LOW TO MID 30S. LOOKS LIKE
STRATUS WILL MOVE BACK INTO THE AREA LATER TODAY INTO TONIGHT FROM
NORTHWEST TO SOUTHEAST IN A WEAK COLD AIR ADVECTION REGIME. THESE
CLOUDS AND A CONTINUED NORTHERLY BREEZE SHOULD KEEP LOWS IN THE LOW
20S. LOW LEVEL MOISTURE EVENTUALLY BECOMES PRETTY DEEP BY LATER
TONIGHT INTO THURSDAY MORNING...SUGGESTING WE COULD END UP SEEING
SOME SCATTERED FLURRIES FROM THE LOW CLOUDS. AREA OF UPPER LEVEL
DIVQ IS ALSO OVERHEAD THURSDAY...BUT ENOUGH MID LEVEL DRY AIR
EXISTS...THAT FEEL ANY FLURRIES THAT DO FALL WILL BE LOW STRATUS
BASED...AND NOT FROM THE UPPER LEVEL FORCING...AND THE BEST THREAT
OF THIS WILL PROBABLY BE ALONG AND NORTH OF INTERSTATE 90. HIGHS
THURSDAY LIKELY A BIT COOLER THAN TODAY...MAINLY UPPER 20S TO LOW
30S.
SOME SIGNS THAT WE SEE A FRONTAL BAND OF SNOW ON THURSDAY NIGHT INTO
FRIDAY MORNING AS A WAVE AND SURFACE LOW DROPS SOUTHEAST. NAM IS
MOST AGGRESSIVE WITH THIS FEATURE...BUT THE GFS...SREF AND ECMWF ALL
HINTING AT SOMETHING. THUS WILL ADD IN A SLIGHT CHANCE OF SNOW WEST
OF THE JAMES RIVER...WHERE BEST THREAT APPEARS TO BE. OTHERWISE MUCH
OF THE SAME FRIDAY...WITH PARTLY TO MOSTLY CLOUDY SKIES AND HIGHS IN
THE MID 20S TO LOWER 30S. WEST COAST RIDGE TRIES TO BUILD EAST OVER
THE WEEKEND. QUITE THE DIFFERENCE BETWEEN THE GFS AND ECMWF ON HOW
FAR EAST THE RIDGE BUILDS...WITH AROUND A 10C DIFFERENCE IN MODEL
850MB TEMPERATURES...ECMWF BEING WARMER. GEM SEEMS TO BE BETWEEN THE
TWO...AND THUS WILL CONTINUE WITH VALUES CLOSE TO CONSENSUS THROUGH
THE WEEKEND. EVEN IF THE WARMER ECMWF VERIFIES...WARMING WILL LIKELY
BE TEMPERED BY SNOW COVER AND CLOUDINESS. FOR NOW HIGHS IN THE 20S
EAST TO 40S WEST SEEM MOST LIKELY.
ATTENTION WILL THEN TURN TO A WAVE COMING ASHORE ALONG THE PACIFIC
NORTHWEST COAST...WHICH WILL DIVE SOUTHEAST INTO THE PLAINS MONDAY
INTO MONDAY NIGHT. ECMWF AND GEM A BIT STRONGER WITH THIS WAVE AND
THUS A LITTLE FURTHER SOUTH. WILL HAVE TO CONTINUE TO MONITOR
TRENDS...BUT AT THIS TIME FAVOR A SOLUTION CLOSER TO THE GEM AND
ECMWF. THIS SYSTEM DOES HAVE SOME DECENT MOISTURE TO WORK WITH...SO
WHILE NOT EXPECTING ANYTHING TOO SIGNIFICANT...THINK AN AREA OF
ACCUMULATING SNOW IS PROBABLE TO THE NORTH OF THE LOW TRACK. IN FACT
THE ECMWF SHOWS A LARGE SWATH OF 0.4 TO 0.7 INCHES OF QPF IN A BAND
NORTH OF THE LOW TRACK. EVEN IF THIS IS OVERDONE...WOULD EXPECT AT
LEAST LIGHT SNOW ACCUMULATIONS...WITH POTENTIALLY A NARROWER AREA OF
MORE MODERATE AMOUNTS. AGAIN WHERE THIS OCCURS IS STILL
UNCERTAIN...AND IF THE SOUTHWARD TREND ON THE ECMWF WERE TO
CONTINUE...MOST OF THE SNOW COULD EVEN END UP SOUTHWEST OF OUR CWA.
EITHER WAY SOMETHING TO WATCH OVER THE COMING DAYS. PRECIP TYPE MAY
INITIALLY BE RAIN OR SNOW...BUT WITH THE SOUTHWARD TREND...EXPECTING
MAINLY SNOW WITH ANYTHING THAT ENDS UP FALLING. TEMPERATURES SHOULD
STAY A LITTLE BELOW NORMAL BEHIND THIS SYSTEM INTO EARLY NEXT WEEK.
/CHENARD
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
THE SIOUX FALLS FORECAST AREA HAS NOW LOST ALL STRATUS EXCEPT FOR A
NARROW STRIPE OF IFR EXTENDING FROM KYKN TO KSUX. THE STRATUS IN
THIS AREA CONTINUES TO BE OBSCURED ON THE IR SATELLITE BY ABUNDANT
HIGH LEVEL CLOUDINESS. BUT WITH LOW LEVEL WINDS FROM THE NORTH AND
NORTHWEST...IT IS LIKELY THAT DRIER AIR WILL ALSO ENTRAIN INTO THESE
AREAS SHORTLY...AND THUS GIVE THE KSUX TAF SITE VFR CONDITIONS BY
EARLY THIS MORNING. TO THE WEST OF OUR FORECAST AREA...PLENTY OF
MVFR STRATUS EXISTS IN CENTRAL SD AND ND. EVENTUALLY...THIS STRATUS
WILL BEGIN TO MOVE INTO OUR WESTERN ZONES. BUT IT MAY TAKE AWHILE AS
WINDS AT 925MB WILL REMAIN DUE NORTHERLY THROUGH THE MORNING HOURS
IN OUR FORECAST AREA. BOTH THE NAM12 AND RAP MODELS STRONGLY SUGGEST
THAT THE MVFR CEILINGS WILL NOT GET INTO THE KHON TAF SITE UNTIL
ABOUT 20Z. THIS AFTERNOON...THE 925MB WINDS DO INDEED BECOME MORE
NORTHWESTERLY AS OPPOSED TO NORTH...SO THIS MAKES SENSE AT THIS
TIME. EXTRAPOLATING THE STRATUS FURTHER EASTWARD...GIVES AN MVFR
ARRIVAL OF AROUND 00Z/28 FOR KFSD...AND ABOUT 02Z/28 FOR KSUX.
LASTLY...NORTHWEST SURFACE WINDS WILL BE RATHER BREEZY IN THE LATE
MORNING AND AFTERNOON AT 15 TO 25 KNOTS EAST OF THE JAMES RIVER
VALLEY. HOWEVER DUE TO A WELL MIXED DAY TODAY...THERE WILL LIKELY
NOT BE ANY VISIBILITY RESTRICTIONS TONIGHT BELOW THE VFR OR MVFR
CATEGORY. /MJF
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1006 AM MST WED FEB 27 2013
.UPDATE...
&&
.SHORT TERM...CURRENT FORECASTS LOOK ON TRACK. NORTHERLY FLOW
FINALLY WEAKENING ACROSS THE PLAINS WITH SURFACE OBS SHOWING WINDS
DECREASING THOUGH STILL SOME GUSTS AROUND 25 KTS. COULD REMAIN A
BIT GUSTY FAR EASTERN ZONES THROUGH THE AFTERNOON AS MODELS STILL
SHOW A NORTHERLY GRADIENT. SOME MOISTURE STILL TRAPPED ACROSS THE
MOUNTAINS...WITH WEB CAMS SHOWING SOME LIGHT SNOW ALONG THE RIDGES
OF SUMMIT AND GRAND COUNTIES. COULD ALSO BE SOME LIGHT SNOW OVER
THE PARK AND GORE RANGES OF JACKSON COUNTY. LATEST RAP CROSS
SECTIONS MAINTAIN SOME MOISTURE THERE THROUGH THE AFTERNOON ALONG
WITH MODEST LAPSE RATES AND OROGRAPHICS. WILL KEEP SOME LIGHT SNOW
THERE THROUGH THE DAY. ANY ACCUMULATIONS TO BE MINIMAL. SLIGHT
WARMING EXPECTED TODAY WITH GOOD SUNSHINE...THOUGH RECENT SNOWFALL
WILL SLOW PROGRESS.
.AVIATION...SKIES HAVE CLEARED ACROSS THE AREA AIRPORTS AS DRIER
AIR HAS SPREAD OVER THE REGION. LATEST MODELS SHOWING WINDS
SHIFTING TO THE NORTHWEST AROUND 18 OR 19Z WITH SPEEDS AROUND
8 KTS...THEN WEAKENING AROUND 21Z AND A BIT MORE NORTHERLY. RAP
AND HRRR SUGGESTING NORTHEAST TO EAST WINDS AFTER 21Z WITH THE
DEVELOPMENT OF A WEAK ANTICYCLONE. WITH NORTHWEST FLOW ALOFT...
UNSURE ABOUT THE ANTICYCLONE DEVELOPING AND WILL MAINTAIN THE
CURRENT TAF TRENDS.
&&
.PREV DISCUSSION... /ISSUED 444 AM MST WED FEB 27 2013/
UPDATE...
SHORT TERM...UPDATED TO REMOVE THE EXPIRATION OF THE ADVISORY
FROM PORTIONS OF THE PLAINS. 88D SHOWING LIGHT ECHOES RAPIDLY
DIMINISHING.
PREV DISCUSSION... /ISSUED 309 AM MST WED FEB 27 2013/
SHORT TERM...THE AREA OF SNOW ACROSS THE NORTHEAST PLAINS IS EVER
SO SLOWLY BEGINNING TO SHRINK IN COVERAGE. EARLIER HAD EXTENDED
THE ADVISORY UNTIL 4 AM AND THINK THAT SHOULD BE FINE. THERE
STILL MAY BE SOME AREAS OF VERY LIGHT SNOW THROUGH THE EARLY
MORNING HOURS BUT ANY ADDITIONAL ACCUMULATION WILL BE UNDER A HALF
INCH. THERE ARE STILL SOME GUSTY WINDS ON THE PLAINS BUT THESE
WINDS WILL ALSO DECREASE THIS MORNING AS THE SURFACE GRADIENT
RELAXES. STILL QUITE A BIT OF CLOUD COVER UPSTREAM SO HAVE DELAYED
SOME OF THE CLEARING THIS MORNING. A SLOW MODERATION OF
TEMPERATURES THIS AFTERNOON WITH MOSTLY SUNNY SKIES. FOR
TONIGHT...WILL SOME INCREASING MID AND HIGH LEVEL CLOUDS IN
ADVANCE OF NEXT SYSTEM.
LONG TERM...YET ANOTHER DISTURBANCE IN THE NORTHWEST FLOW ALOFT
WILL SWING DOWN OVER NORTHEAST COLORADO THURSDAY INTO FRIDAY.
THIS SYSTEM SHOULD MAINLY AFFECT THE MOUNTAINS IN THE FAVORED
FLOW...HOWEVER SOME MODELS ARE PICKING UP ON A POSSIBILITY OF A
FEW SHOWERS MOVING OVER THE PLAINS. OVERALL...MODEL AGREEMENT IS
POOR ON THE UPPER LEVELS OF THIS DISTURBANCE...AND NORTHWEST FLOW
IS USUALLY MORE OF A DOWNSLOPE PATTERN FOR THE PLAINS. HOWEVER
CANNOT IGNORE ABOUT HALF OF THE MODELS VIEWED SHOWING LIGHT
PRECIPITATION. RUN TO RUN CONSISTENCY IS NOT THE BEST WITH THIS
PIECE OF ENERGY...WITH TIMING DIFFERENCES WITH EACH NEW RUN. THE
BEST TIME FRAME HOWEVER LOOKS TO BE THURSDAY EVENING FOR A FEW
SHOWERS OVER THE PLAINS. OTHERWISE...SNOW WILL BE INCREASING OVER
THE MOUNTAINS THROUGH THE DAY THURSDAY AND INTO THE NIGHT...BEFORE
EASING OFF FRIDAY. ACCUMULATIONS OVER THE MOUNTAINS WILL MAINLY BE
OROGRAPHICALLY DRIVEN...LEAVING THE HIGHEST AMOUNTS ON WEST TO
NORTHWEST FACING SLOPES. CURRENTLY EXPECT 3 TO 6 INCHES THURSDAY
THROUGH FRIDAY AFTERNOON. THURSDAY TEMPERATURES WILL BE SIMILAR TO
TODAYS WITH ONLY A DEGREE OR TWO OF WARMING. FRIDAY WILL SEE
TEMPERATURES WARM EVEN MORE WITH THE PLAINS FINALLY REACHING INTO
THE LOW 40S AND THE MOUNTAINS IN THE 20S. NORTHWESTERLY SURFACE WINDS
WILL BE INCREASING THURSDAY AND INTO FRIDAY AS A 115 KT N TO S JET
MOVES OVERHEAD AND AIDED BY SURFACE PRESSURE GRADIENT FROM HIGH
PRESSURE OVER SW WYOMING AND LOWER PRESSURE OVER TEXAS. NO
HIGHLIGHTS ARE NEEDED. GUSTS MAY REACH 40 TO 50 MPH IN THE
FOOTHILLS AND UP TO 30 MPH OVER THE PLAINS THURSDAY NIGHT INTO
FRIDAY.
FRIDAY NIGHT INTO SUNDAY AFTERNOON...AN UPPER RIDGE BUILDS
OVERHEAD TO BRING WARMER AND DRIER CONDITIONS. TEMPERATURES ARE
EXPECTED TO RETURN TO NEAR NORMAL READINGS WITH UPPER 40S TO LOW
50S FOR THE PLAINS AND 30S TO LOW 40S FOR THE MOUNTAINS.
SUNDAY NIGHT AND INTO MONDAY IS THE NEXT CHANCE FOR MORE
PRECIPITATION FOR THE FORECAST AREA. MODELS SHOWING A PACIFIC
NORTHWEST SYSTEM DIGGING SOUTHEAST TOWARD THE AREA SUNDAY
NIGHT...HOWEVER WITH A DEEPER AND SLOWER SOLUTION SHOWN BY THE
ECMWF AND A WEAKER AND MORE PROGRESSIVE SOLUTION BY THE GFS...AND
AN EVEN MORE PROGRESSIVE SOLUTION BY THE CANADIAN MODEL. WILL KEEP
THE CHANCE OF SNOW FOR THE MOUNTAINS SUNDAY NIGHT INTO MONDAY AND
PUT A SLIGHT CHANCE FOR THE PLAINS SUNDAY NIGHT AS MODELS SHOWING
SOME SORT OF COLD FRONT MARCHING DOWN THEN.
THEN YET ANOTHER UPPER RIDGE WILL BUILD IN MONDAY EVENING INTO
WEDNESDAY FOR ANOTHER WARMING AND DRYING TREND.
AVIATION...MID LEVEL DECK OF CLOUDS IN THE 6000 TO 8000 FT AGL
LEVEL WILL HANG THRU MID MORNING GIVEN THE OBSERVATIONS TO THE
NORTHWEST ACROSS WYOMING. SKIES WILL BECOME MOSTLY SUNNY THIS
AFTERNOON. NORTH TO NORTHWEST SURFACE WINDS WILL PERSIST THIS
MORNING BUT SPEEDS GENERALLY UNDER 15KT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....KRIEDERMAN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS JACKSON KY
124 PM EST WED FEB 27 2013
.UPDATE...
ISSUED AT 124 PM EST WED FEB 27 2013
UPDATED TEMPS FOR THIS AFTERNOON AND EVENING BASED ON CURRENT OBS AND
THE HRRR MODEL. ALSO ADJUST PRECIP TYPE BASED ON THIS TONIGHT. THE
IMPACT ON THE OVERALL FORECAST IS NEGLIGIBLE.
UPDATE ISSUED AT 1007 AM EST WED FEB 27 2013
BASED ON RADAR TRENDS AND FORECAST SOUNDINGS...HAVE ADDED MORE RAIN
AND DRIZZLE TO THE FORECAST FOR TODAY...BUT ALL POPS ARE IN THE 20-30
PERCENT RANGE.
UPDATE ISSUED AT 627 AM EST WED FEB 27 2013
PRECIPITATION HAS TAPERED TO PRETTY MUCH JUST DRIZZLE AS THE COOLER
CLOUD TOPS HAVE EXITED. RUC/NAM BUFR SOUNDINGS CONTINUE TO SHOW A
LITTLE BIT OF MOISTURE ABOVE THE LOW LEVEL INVERSION SUPPORTING
DRIZZLE THROUGH MID MORNING. HOWEVER...SOME WEAK MID LEVEL SUBSIDENCE
WILL ESSENTIALLY TAKE ITS TOLL ON THIS SHALLOW MOISTURE BY LATE THIS
MORNING...LEAVING BEHIND GENERALLY OVERCAST SKIES. THE DRY CONDITIONS
ARE STILL EXPECTED TO PERSIST THROUGH THE AFTERNOON AND LIKELY INTO
THE EARLY EVENING HOURS. RAP/HRRR ALONG WITH SUPPORT FROM THE NAM HAS
RAIN SPREADING BACK INTO THE AREA TOWARDS 00Z TONIGHT. RAP/NAM STILL
STRONGLY SUPPORT MAINLY RAIN AT THE ONSET AS SURFACE TEMPERATURES
REMAIN TOO WARM FOR SNOW. HOWEVER...AS PRECIPITATION INTENSITY
INCREASES...WE SHOULD WETBULB DOWN CLOSER TO FREEZING FAIRLY QUICKLY
CHANGING ANY RAIN OVER TO SNOW BY LATE EVENING. ALL OF THIS IS STILL
IN LINE WITH THE LATEST FORECAST AND SEE NO REASON TO MAKE ANY
SIGNIFICANT CHANGES AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 306 AM EST WED FEB 27 2013
AN UPPER LEVEL LOW WILL CONTINUE TO DRIFT EASTWARD ACROSS THE OHIO
RIVER VALLEY OVER THE NEXT 36 TO 48 HOURS. THIS WILL PROVIDE SEVERAL
ROUNDS OF UNSETTLED WEATHER THROUGH THE REMAINDER OF THE WEEK.
ONGOING LIGHT RAIN/DRIZZLE WILL CONTINUE TO PUSH NORTH AND EAST
THROUGH DAYBREAK. MODEL SOUNDINGS SHOW ICE ACTIVATION DWINDLING
TOWARDS DAYBREAK AS THE BETTER MOISTURE LIFTS TO THE NORTH AND EAST.
THIS WILL LIKELY PROVIDE A PERIOD OF DRIER WEATHER FROM THIS MORNING
INTO THEA AFTERNOON HOURS. HOWEVER...A VIGOROUS TROUGH WILL PUSH
SOUTH INTO EASTERN KENTUCKY LATE IN THE DAY AND TONIGHT...PRODUCING A
PERIOD OF RAIN...POSSIBLY MIXED WITH A LITTLE SNOW THIS EVENING. AS
TEMPERATURES QUICKLY COOL THIS EVENING...RAIN SHOULD QUICKLY
TRANSITION TO SNOW ON THE RIDGES WITH THE VALLEYS FOLLOWING A FEW
HOURS LATER. LOCATIONS ABOVE 1500 FEET WILL LIKELY BE ALL SNOW FROM
THE ONSET...AND WITH TEMPERATURES VERY COOL AT THESE HIGHER
ELEVATIONS...THE LARGEST SNOW ACCUMULATIONS WILL LIKELY FALL ABOVE
1500 FEET. UP TO 3 OR 4 INCHES MAY BE POSSIBLE ABOVE 2000 FEET.
HOWEVER...ALL RIDGES WILL LIKELY SEE SOME MINOR SNOW ACCUMULATIONS
(UNDER A HALF INCH) WITH THE VALLEYS STRUGGLING TO SEE ANY
ACCUMULATION. THE FAVORED UPSLOPE AREAS WILL BE FAVORED WITH THE MOST
SNOW POTENTIAL INTO THURSDAY. SURFACE TEMPERATURES WILL CLIMB INTO
THE MID TO UPPER 30S ON THURSDAY WITH SNOW ACCUMULATIONS NOT MUCH OF
A THREAT DURING THE DAY. IN FACT...WE MAY CHANGEOVER TO RAIN IN
SEVERAL AREAS.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 355 AM EST WED FEB 27 2013
THE MODELS CONTINUE IN FAIR AGREEMENT ALOFT FOR THE LONG TERM
PORTION OF THE FORECAST. THEY ALL TAKE A CLOSED LOW EAST OUT OF THE
REGION ON THURSDAY NIGHT LEAVING BEHIND JUST A GENERAL AREA OF LOW
HEIGHTS. PLENTY OF ENERGY WILL ALSO BE STUCK BACK HERE THROUGH THE
SOUTHERN PLAINS AND TENNESSEE VALLEY. THIS COLLECTION WILL START TO
CONSOLIDATE ON FRIDAY TO FORM A NEW SEMI-CLOSED LOW OVER THE
REGION...PRIMARILY IN RESPONSE TO A STRONG RIDGE BUILDING OVER THE
WEST. THE DEVELOPING LOW WILL SWIRL PLENTY OF SHORTWAVE
ENERGY...THOUGH GENERALLY WEAK...THROUGH THE AREA INTO SATURDAY
MAINTAINING UNSETTLED WEATHER. THE GFS FORMS ITS UPPER LOW A BIT
QUICKER THAN THE GEM AND ECMWF...MAINTAINING A STRONGER SOLUTION
THROUGH THE WEEKEND. GIVEN THE MODEL TRENDS WILL FAVOR A WEAKER
VERSION OF THE GFS...BUT DO LIKE ITS MORE PROGRESSIVE SOLUTION. THE
UPPER LOW WILL BECOME MORE OF A DEEP TROUGH THROUGH THE EASTERN HALF
OF THE NATION BY SUNDAY MORNING AND GET SHOVED EAST BY THE STRONG
WESTERN RIDGING. CONTINUING WITH THE CONSENSUS SOLUTION...HEIGHTS
WILL RISE OVER THE AREA LATER SUNDAY AND CERTAINLY INTO MONDAY AS
ENERGY TOPS THE RIDGE AND SLIDES BY JUST TO OUR EAST. HOWEVER...THE
PATTERN BECOMES MORE MUDDLED HEADING INTO THE MIDDLE OF NEXT WEEK AS
THE WESTERN RIDGE IS BASICALLY WIPED OUT BY ENERGY MOVING INTO THE
PLAINS AND IT SLINKS THROUGH THE AREA AS JUST A WEAK AND SHORT LIVED
RISE IN HEIGHTS MONDAY NIGHT. BY TUESDAY...THE ENERGY FROM THE RIDGE
KILLING WAVE WILL REACH THE MID SECTION OF THE NATION AND START TO
IMPACT THE OHIO VALLEY.
SENSIBLE WEATHER WILL FEATURE A CHILLY PATTERN WITH SEVERAL REINFORCING
SHOTS OF COLD AIR THROUGH THE WEEKEND. THE FIRST PART OF THE EXTENDED
WILL SEE SNOW SHOWERS ACCOMPANY THE COLDER AIR. HOWEVER...DEEP LAYER
MOISTURE AND UPPER LEVEL SUPPORT WILL BE LIMITED FOR MUCH OF THIS
TIME. ACCORDINGLY...THE ACCUMULATIONS ARE EXPECTED TO BE LIGHT AND
MAINLY CONFINED TO THE NIGHT TIME HOURS. THE HIGHER TERRAIN IN THE
FAR SOUTHEAST PARTS OF THE CWA WILL SEE THE BEST CHANCE FOR ANY
ACCUMULATION MEASURED IN MULTIPLE INCHES...WHILE THE REST OF THE AREA
WILL LIKELY END UP WITH LESS THAN AN INCH. THE BEST SHOT AT SEEING
LIGHT ACCUMULATIONS...EVEN IN THE VALLEYS...WILL BE THURSDAY NIGHT
GIVEN A COLDER AIR MASS. CERTAINLY ANY HEAVIER BURST OF SNOW OR
BANDING COULD LEAD TO BRIEF ACCUMULATIONS DURING THE DAYLIGHT
HOURS...BUT THESE ARE LIKELY TO BE THE EXCEPTION RATHER THAN THE
RULE THROUGHOUT THE PERIOD. THE REAL PROBLEM IS THE LACK OF A SOLID
SFC WAVE TO GEN UP THE PCPN THAT COULD TAKE ADVANTAGE OF THE COLD AIR
AND GIVE MORE THAN OCCASIONAL SKIFFS OF ACCUMULATION. LINGERING SNOW
SHOWERS THROUGH THE DAY SATURDAY AND INTO SUNDAY IN THE FAR SOUTHEAST
WILL KEEP THE POTENTIAL FOR SOME ADDITIONAL ACCUMULATIONS IN THE
FORECAST WITH THE HIGHER TERRAIN FAVORED...BUT CHILLY TEMPS EVEN
DURING THE DAY MAY ALSO ALLOW FOR LIGHT ACCUMULATIONS IN THE
VALLEYS THERE...TOO. THE BULK OF THE PCPN MOVES OUT BY SUNDAY WITH
JUST A SMALL CHANCE FOR A LEFT OVER SNOW SHOWER IN THE FAR EAST.
OTHERWISE...THE NEXT CHANCE OF SNOW OR RAIN WILL NOT BE UNTIL MONDAY
NIGHT AND CONTINUING INTO TUESDAY AS A SFC WAVE MOVES OUT OF THE
PLAINS.
THE CR GRID BLEND CAME IN DECENT ENOUGH...GIVEN THE PROMINENCE OF THE
GFS. DID FINE TUNE THE POP GRIDS TO ENHANCE THEM IN THE HIGHER
EASTERN TERRAIN AND DIMINISH THEM FURTHER WEST...AT LEAST THROUGH
SATURDAY. ONLY MADE MINOR TERRAIN BASED ADJUSTMENTS TO TEMPERATURES
THROUGH THE EXTENDED...MAINLY TO COOL THE RIDGES A BIT MORE DURING
THE DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1259 PM EST WED FEB 27 2013
MAINLY MVFR CONDITIONS WERE PRESENT AT TAF ISSUANCE...DUE TO
CEILINGS. THERE WAS ALSO DRIZZLE IN MANY AREAS. LATE TODAY RAIN
SHOULD DEVELOP OVER THE REGION FROM NW TO SE BETWEEN ABOUT 21Z AND
00Z. THE RAIN WILL MIX WITH SNOW FROM NW TO SE BETWEEN ABOUT 01Z AND
04Z...REDUCING VISIBILITY. VISIBILITY WILL VARY AS THE SNOW BEGINS...
BUT ON AVERAGE SHOULD STILL BE MVFR. THE PRECIPITATION SHOULD THEN
EASE SOMEWHAT AS IT CHANGES TO ALL SNOW FROM NW TO SE BETWEEN ABOUT
03Z AND 06Z. MAINLY LIGHT SNOW WILL THEN CONTINUE AT TIMES THROUGH
THE REMAINDER OF THE PERIOD. CEILINGS ARE EXPECTED TO LOWER TO IFR
FOR A PERIOD OF SEVERAL HOURS CENTERED AROUND DAWN...WITH MVFR
CONDITIONS OTHERWISE EXPECTED OVERNIGHT AND ON THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
340 PM EST WED FEB 27 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL MOVE ACROSS THE AREA OVERNIGHT AND PUSH
INTO THE NORTHEAST FOR THE END OF THE WEEK. AS THE LOW SHIFTS EAST
OF THE REGION...COLDER AIR WILL FILTER INTO THE AREA TONIGHT AND
ALLOW FOR A MIX OF RAIN AND SNOW SHOWERS TO CHANGE OVER TO MOSTLY
SNOW SHOWERS INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A RATHER ELONGATED
CLOSED UPPER LOW THAT STRETCHES ACROSS THE SOUTHERN GREAT LAKES
AND OHIO VALLEY. AT THE SURFACE...A 999MB LOW IS CENTERED ACROSS
SOUTHERN MICHIGAN WITH ANOTHER LOW DEVELOPING AS IT MOVES
NORTHWARD ACROSS NEW JERSEY. THE LOW IN MICHIGAN IS DRIVING A
SOUTHWESTERLY FLOW ACROSS THE AREA THIS TODAY. SOUNDINGS INDICATE A
SFC-900MB MELTING LAYER STRONG ENOUGH TO ALLOW FOR PRECIP SOUTH
AND WEST OF PITTSBURGH TO BE ALL RAIN. 1000-700MB 2840M THICKNESS
LINE ALSO SEEMS TO COINCIDE FAIRLY WELL WITH RAIN/SNOW LINE
NORTHEAST OF PITTSBURGH.
THIS EVENING...THE BROAD UPPER LOW WILL SLOWLY MEANDER EASTWARD
ACROSS THE OHIO VALLEY...WITH THE NEXT VORT LOBE SWINGING AROUND
ITS BASE. WRF-ARW 1KM SIMULATED REFLECTIVITY DEPICTS MORE
CONVECTIVE SHOWERS EARLY THIS EVENING...SO HAVE GONE WITH
ISOLATED/SCATTERED INCREASING TO MORE NUMEROUS AS THE UPPER LOW
APPROACHES FROM THE WEST. DESPITE COLDER AIR ADVECTING IN WITH
THE COLD POOL ALOFT AND ASSOCIATED UPPER LOW...GFS/NAM SOUNDINGS
CONTINUE TO INDICATE PRECIPITATION WILL FALL INITIALLY AS RAIN
WITH A SUFFICIENT SFC-900MB MELTING LAYER REMAINING IN PLACE.
THUS...FORECAST BEINGS WITH MOSTLY RAIN...EXCEPT FOR SOME RAIN-SNOW
CLOSER TO 1000-700MB CRITICAL THICKNESS ACROSS THE NORTH AND WITH
THE LACK OF A PRONOUNCED MELTING LAYER ACROSS THE RIDGES.
OVERNIGHT...GFS/NAM AGREE THAT THE UPPER LOW WILL CROSS THE AREA AS
IT SHIFTS FROM WESTERN OHIO INTO WESTERN NY. WEAK CAA AND COOLING
SFC-900MB LAYER WILL ALLOW FOR ENTIRE COLUMN TO DROP BELOW
FREEZING AND PRECIPITATION TO CHANGE OVER TO ALL SNOW SHOWERS
TONIGHT. ACCUMULATIONS WILL BE AN INCH OR LESS FOR SOUTHWEST
PA...EASTERN OHIO...AND NORTHERN WV WITH 1 TO 2 INCHES POSSIBLE
TONIGHT ACROSS THE ALLEGHENY FRONT/LAUREL HIGHLANDS AND I-80
CORRIDOR. TEMPS TONIGHT ARE FAIRLY CLOSE TO A MAV/MET BLEND...WITH
LOWS RANGING FROM THE MID 20S ACROSS THE EASTERN RIDGES TO THE
LOWER 30S ELSEWHERE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
A MODEL CONSENSUS INDICATES THAT THE UPPER LOW WILL SLOWLY MEANDER
EASTWARD INTO NEW ENGLAND THURSDAY AND FRIDAY...LEAVING THE UPPER
OHIO VALLEY IN A MOIST...NORTHWESTERLY FLOW OFF OF THE GREAT
LAKES.
THE LOW-LEVEL FLOW WILL BE CLOSE TO ZONAL MUCH OF THE DAY THURSDAY
AS A SERIES OF VORT LOBES ROTATES AROUND THE UPPER LOW AND INTO
THE AREA. WITH SFC TEMPS WARMING TO THE MID TO UPPER 30S ACROSS
THE LOWLANDS...ANTICIPATE LITTLE ACCUMULATION DURING DAYLIGHT
HOURS ACROSS THE LOWLANDS. WITH SOME UPSLOPING AND TEMPS IN THE
LOWER 30S...1 TO 2 INCHES WILL BE POSSIBLE ACROSS THE HIGHER
ELEVATIONS.
VORT ENERGY WILL SLIDE EAST OF THE UPPER OHIO VALLEY THURSDAY
NIGHT INTO FRIDAY. DURING THIS TIME...THE LOW-LEVEL FLOW WILL
VEER TO MORE NORTH-NORTHWESTERLY...ALLOWING FOR A MOISTURE FETCH
OFF OF LAKE HURON WITH MOISTURE LACKING FROM A PARTIALLY FROZEN
LAKE ERIE. ONE LIMITING FACTOR DESPITE THE NNWRLY FLOW WILL BE
THAT THE AIR MASS WILL NOT BE QUITE COLD ENOUGH TO SUPPORT LAKE
EFFECT. THUS...ANTICIPATE LITTLE MORE THAN SCATTERED SNOW SHOWERS
THROUGH THIS PERIOD WITH AROUND AN INCH FOR THE LOWLANDS AND AN
ADDITIONAL 1 TO 2 FOR THE RIDGES. TEMPS THROUGH THIS PERIOD WILL
BE AROUND 5 DEGREES BELOW NORMAL WITH THE NORTHERLY COMPONENT
CONTINUING TO PULL COOLER...CANADIAN AIR INTO THE AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ECMWF AND GFS INDICATE CONTD MAINTENANCE OF THE ERN NORTH
AMERICAN TROF VIA SHRTWV ENERGY THRU THE LONG TERM PD. THE
EXTENDED FORECAST THUS CONTINUES TO FEATURE SUB AVERAGE TEMPS AND
NR CLIMO/CHC POPS UNTIL THE TROF AXIS SHIFT SUFFICIENTLY
EWD...PROBABLY BY SATURDAY.
SHRTWV RIDGE IN ADVN OF MIDWRN LOW IS CURRENTLY PROGGED TO
SUPPRESS PRECIP PROBABILITIES...UNTIL THE LOW INITIATES PCPN LTR
ON TUE. CONFIDENCE IN THAT PORTION OF THE FORECAST IS MINIMAL
GIVEN PROJECTIONS OF A CUTOFF SYSTEM WITH QUESTIONS OF MAGNITUDE
AND PLACEMENT OF THE LOW CENTERS.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
GENL MVFR WITH STRATOCU CIGS WITH REDEVELOPMENT OF RAIN AND SNOW
SHOWERS CAN BE EXPECTED FOR THE TAF PD AS UPR LOW PRES DRIFTS ACRS
THE REGION.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
RESTRICTIONS ARE LIKLEY WITH CIGS AND -SHSN INTO THE WEEKEND. A
RETURN TO WIDESPREAD VFR CONDITIONS MAY NOT OCCUR UNTIL SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...WOODRUM
LONG TERM...15
AVIATION...15
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1259 PM EST WED FEB 27 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL MOVE ACROSS THE AREA TODAY AND PUSH INTO THE
NORTHEAST FOR THE END OF THE WEEK. AS THE LOW SHIFTS EAST OF THE
REGION...COLDER AIR WILL FILTER INTO THE AREA TONIGHT AND ALLOW
FOR A MIX OF RAIN AND SNOW SHOWERS TODAY TO CHANGE OVER TO
MOSTLY SNOW SHOWERS TONIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN
ISSUED TO BEGIN MIXING IN SNOW WITH RAIN SHOWERS 1-2 HOURS EARLIER
ACROSS THE AREA THIS EVENING. THE REST OF THE PREVIOUS DISCUSSION
REMAINS THE SAME.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A RATHER ELONGATED
CLOSED UPPER LOW THAT STRETCHES ACROSS THE SOUTHERN GREAT LAKES
REGION. 500MB VORT ENERGY ALONG WITH 700MB OMEGA INDICATE THAT AN
AREA OF LIFT SPAWNING MORE WIDESPREAD RAIN/SNOW THIS MORNING
NORTHEAST OF PITTSBURGH HAS SHIFTED INTO NORTH-CENTRAL PA AND NEW
YORK. NVA IN ITS WAKE IS ALLOWING FOR A BREAK IN PRECIPITATION
ACROSS MOST OF THE AREA. AT THE SURFACE...A 999MB LOW IS CENTERED
ACROSS SOUTHERN MICHIGAN WITH ANOTHER LOW DEVELOPING AS IT MOVES
NORTHWARD ACROSS NEW JERSEY. THE LOW IN MICHIGAN IS DRIVING A
SOUTHWESTERLY FLOW ACROSS THE AREA THIS TODAY. THE 12Z KPIT
SOUNDING INDICATES A SFC-900MB MELTING LAYER STRONG ENOUGH TO
ALLOW FOR MOSTLY PRECIP SOUTH AND WEST OF PITTSBURGH TO BE ALL
RAIN. 1000-700MB 2840M THICKNESS LINE ALSO SEEMS TO COINCIDE
FAIRLY WELL WITH RAIN/SNOW LINE NORTHEAST OF PITTSBURGH.
THIS AFTERNOON...THE BROAD UPPER LOW WILL SLOWLY MEANDER EASTWARD
ACROSS THE OHIO VALLEY...WITH THE NEXT VORT LOBE SWINGING AROUND
ITS BASE THIS EVENING. WRF-ARW 1KM SIMULATED REFLECTIVITY DEPICTS
MORE CONVECTIVE SHOWERS THIS AFTERNOON AND EARLY EVENING...SO HAVE
GONE WITH ISOLATED/SCATTERED INCREASING TO MORE NUMEROUS AS THE
UPPER LOW APPROACHES FROM THE WEST. 850MB TEMPS WILL COOL FROM -1
TO -2C TO -3 TO -4C BY THIS EVENING. DESPITE COLDER AIR ADVECTING
IN WITH THE COLD POOL ALOFT AND ASSOCIATED UPPER LOW...GFS/NAM
SOUNDINGS CONTINUE TO INDICATE PRECIPITATION WILL FALL AS MOSTLY
RAIN TODAY WITH A SUFFICIENT SFC-900MB MELTING LAYER REMAINING IN
PLACE. THUS...HAVE GONE WITH MOSTLY RAIN IN THE FORECAST
TODAY...EXCEPT FOR SOME RAIN-SNOW CLOSER TO 1000-700MB CRITICAL
THICKNESS ACROSS THE NORTH AND WITH THE LACK OF A PRONOUNCED
MELTING LAYER ACROSS THE RIDGES. SOUTHWESTERLY FLOW WILL ALLOW
TEMPS TO WARM A FEW DEGREES THIS AFTERNOON...WITH HIGHS CLOSE TO
LAMP GUIDANCE...RANGING FROM THE MID 30S ACROSS THE EASTERN RIDGES
TO THE MID 40S SOUTH AND WEST OF PITTSBURGH.
TONIGHT...GFS/NAM AGREE THAT THE UPPER LOW WILL CROSS THE AREA AS
IT SHIFTS FROM WESTERN OHIO INTO WESTERN NY. WEAK CAA AND COOLING
SFC-900MB LAYER WILL ALLOW FOR ENTIRE COLUMN TO DROP BELOW
FREEZING AND PRECIPITATION TO CHANGE OVER TO ALL SNOW SHOWERS
TONIGHT. ACCUMULATIONS WILL BE AN INCH OR LESS FOR SOUTHWEST
PA...EASTERN OHIO...AND NORTHERN WV WITH 1 TO 2 INCHES POSSIBLE
TONIGHT ACROSS THE ALLEGHENY FRONT/LAUREL HIGHLANDS AND I-80
CORRIDOR. TEMPS TONIGHT ARE FAIRLY CLOSE TO A MAV/MET BLEND...WITH
LOWS RANGING FROM THE MID 20S ACROSS THE EASTERN RIDGES TO THE
LOWER 30S ELSEWHERE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
MATURE/STACKED AND COLD LOW PRES WILL WOBBLE ACROSS THE REGION
THROUGH THURSDAY...AND DIG OFF THE COAST BY FRIDAY ACCORDING TO
THE LATEST MODEL SOLNS. SCT TO NMRS SHSN WL THUS CONT TO PLAGUE THE
REGION FOR THE SHORT TERM PD...WITH UPSLOPE COMPONENT OF WIND
ENHANCING SN POTENTIAL IN THE RIDGES.
OVERALL ACCUMULATION POTENTIAL WL BE RETARDED OVR AREAS WHERE
DAYTIME TEMPS RISE ABOVE FREEZING...SO HEADLINE POTENTIAL IS
LIMITED. THE EXCEPTION MAY BE FOR THE RIDGES WHERE PROLONGED SHSN
MAY REQUIRE A COUPLE-DAY ADVISORY. FOR NOW...WL MENTION IN THE
HAZARDOUS WEATHER OUTLOOK AND TASK FUTURE SHIFTS TO MONITOR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ECMWF AND GFS INDICATE CONTD MAINTENANCE OF THE ERN NORTH
AMERICAN TROF VIA SHRTWV ENERGY THRU THE LONG TERM PD. THE
EXTENDED FORECAST THUS CONTINUES TO FEATURE SUB AVERAGE TEMPS AND
NR CLIMO/CHC POPS UNTIL THE TROF AXIS SHIFT SUFFICIENTLY
EWD...PROBABLY BY SUNDAY.
SHRTWV RIDGE IN ADVN OF MIDWRN LOW IS CURRENTLY PROGGED TO
SUPPRESS PRECIP PROBABILITIES...UNTIL THE LOW INITIATES PCPN LTR
ON TUE. CONFIDENCE IN THAT PORTION OF THE FORECAST IS MINIMAL
GIVEN PROJECTIONS OF A CUTOFF SYSTEM WITH QUESTIONS OF MAGNITUDE
AND PLACEMENT OF THE LOW CENTERS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
GENL MVFR WITH STRATOCU CIGS WITH REDEVELOPMENT OF RAIN AND SNOW
SHOWERS CAN BE EXPECTED FOR THE TAF PD AS UPR LOW PRES DRIFTS ACRS
THE REGION.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
RESTRICTIONS ARE LIKLEY WITH CIGS AND -SHSN INTO THE WEEKEND. A
RETURN TO WIDESPREAD VFR CONDITIONS MAY NOT OCCUR UNTIL LATE
SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...15
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1114 AM EST WED FEB 27 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL MOVE ACROSS THE AREA TODAY AND PUSH INTO THE
NORTHEAST FOR THE END OF THE WEEK. AS THE LOW SHIFTS EAST OF THE
AREA...COLDER AIR WILL FILTER INTO THE AREA TONIGHT AND ALLOW FOR A
MIX OF RAIN AND SNOW SHOWERS TODAY TO CHANGE OVER TO MOSTLY SNOW
SHOWERS TONIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST TRENDS IN TEMP AND RADAR AS A MIX OF RAIN SNOW
DIMINISHES NORTHEAST OF PITTSBURGH.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A RATHER ELONGATED
CLOSED UPPER LOW THAT STRETCHES ACROSS THE SOUTHERN GREAT LAKES
REGION. 500MB VORT ENERGY ALONG WITH 700MB OMEGA INDICATE THAT AN
AREA OF LIFT SPAWNING MORE WIDESPREAD RAIN/SNOW THIS MORNING
NORTHEAST OF PITTSBURGH IS SHIFTING INTO NORTH-CENTRAL PA AND NEW
YORK. NVA IN ITS WAKE IS ALLOWING FOR A BREAK IN PRECIPITATION
MOVING FROM EASTERN OHIO INTO WESTERN PA. AT THE SURFACE...A 999MB
LOW IS CENTERED ACROSS SOUTHERN MICHIGAN WITH ANOTHER LOW
DEVELOPING AS IT MOVES NORTHWARD ACROSS NEW JERSEY. THE LOW IN
MICHIGAN IS DRIVING A SOUTHWESTERLY FLOW ACROSS THE AREA THIS
TODAY. THE 12Z KPIT SOUNDING INDICATES A SFC-900MB MELTING LAYER
STRONG ENOUGH TO ALLOW FOR MOSTLY PRECIP SOUTH AND WEST OF
PITTSBURGH TO BE ALL RAIN. 1000-700MB 2840M THICKNESS LINE ALSO
SEEMS TO COINCIDE FAIRLY WELL WITH RAIN CHANGING TO SNOW NORTHEAST
OF PITTSBURGH.
TODAY...THE BROAD UPPER LOW WILL SLOWLY MEANDER EASTWARD ACROSS THE
OHIO VALLEY...WITH THE NEXT VORT LOBE SWINGING AROUND ITS BASE THIS
EVENING. WRF-ARW 1KM SIMULATED REFLECTIVITY DEPICTS MORE CONVECTIVE
SHOWERS THIS AFTERNOON AND EARLY EVENING...SO HAVE GONE WITH
ISOLATED/SCATTERED INCREASING TO MORE NUMEROUS AS THE UPPER LOW
APPROACHES FROM THE WEST. 850MB TEMPS WILL COOL FROM -1 TO -2C TO
-3 TO -4C BY THIS EVENING. DESPITE COLDER AIR ADVECTING IN WITH
THE COLD POOL ALOFT AND ASSOCIATED UPPER LOW...GFS/NAM SOUNDINGS
CONTINUE TO INDICATE PRECIPITATION WILL FALL AS MOSTLY RAIN TODAY
WITH A SUFFICIENT SFC-900MB MELTING LAYER REMAINING IN PLACE.
THUS...HAVE GONE WITH MOSTLY RAIN IN THE FORECAST TODAY...EXCEPT
FOR SOME RAIN-SNOW CLOSER TO 1000-700MB CRITICAL THICKNESS ACROSS
THE NORTH AND WITH THE LACK OF A PRONOUNCED MELTING LAYER ACROSS
THE RIDGES. SOUTHWESTERLY FLOW WILL ALLOW TEMPS TO WARM A FEW
DEGREES THIS AFTERNOON...WITH HIGHS CLOSE TO LAMP
GUIDANCE...RANGING FROM THE MID 30S ACROSS THE EASTERN RIDGES TO
THE MID 40S SOUTH AND WEST OF PITTSBURGH.
TONIGHT... GFS/NAM AGREE THAT THE UPPER LOW WILL CROSS THE AREA AS
IT SHIFTS FROM WESTERN OHIO INTO WESTERN NY. WEAK CAA AND COOLING
SFC-900MB LAYER WILL ALLOW FOR ENTIRE COLUMN TO DROP BELOW
FREEZING AND PRECIPITATION TO CHANGE OVER TO ALL SNOW SHOWERS
TONIGHT. ACCUMULATIONS WILL BE AN INCH OR LESS FOR SOUTHWEST
PA...EASTERN OHIO...AND NORTHERN WV WITH 1 TO 2 INCHES POSSIBLE
TONIGHT ACROSS THE ALLEGHENY FRONT/LAUREL HIGHLANDS AND I-80
CORRIDOR. TEMPS TONIGHT ARE FAIRLY CLOSE TO A MAV/MET
BLEND...WITH LOWS RANGING FROM THE MID 20S ACROSS THE EASTERN
RIDGES TO THE LOWER 30S ELSEWHERE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
MATURE/STACKED AND COLD LOW PRES WILL WOBBLE ACROSS THE REGION
THROUGH THURSDAY...AND DIG OFF THE COAST BY FRIDAY ACCORDING TO
THE LATEST MODEL SOLNS. SCT TO NMRS SHSN WL THUS CONT TO PLAGUE THE
REGION FOR THE SHORT TERM PD...WITH UPSLOPE COMPONENT OF WIND
ENHANCING SN POTENTIAL IN THE RIDGES.
OVERALL ACCUMULATION POTENTIAL WL BE RETARDED OVR AREAS WHERE
DAYTIME TEMPS RISE ABOVE FREEZING...SO HEADLINE POTENTIAL IS
LIMITED. THE EXCEPTION MAY BE FOR THE RIDGES WHERE PROLONGED SHSN
MAY REQUIRE A COUPLE-DAY ADVISORY. FOR NOW...WL MENTION IN THE
HAZARDOUS WEATHER OUTLOOK AND TASK FUTURE SHIFTS TO MONITOR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ECMWF AND GFS CONT TO INDICATE DEVELOPMENT OF AN ERN NORTH AMERICAN
TROF FOR THE LONG TERM PD. THE EXTENDED FORECAST THUS CONTINUES
TO FEATURE SUB AVERAGE TEMPS AND NR CLIMO. CHC POPS DEPENDENT ON
SPPRTG SHRTWV ENERGY FOR THE INTIAL PDS.
SHRTWV RIDGE IN ADVN OF MIDWRN LOW SHOULD REDUCE THOSE POPS BY
MONDAY...BUT THAT REPRIEVE LOOKS TO BE BRIEF AS PCPN FM THAT SYSTEM
IS CURRENTLY TIMED FOR A TUE INITIATION OVR THE UPR OH VALLEY.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
GENL MVFR WITH STRATOCU CIGS AND PERIODIC RAIN AND SNOW SHOWERS
CAN BE EXPECTED FOR THE TAF PD AS UPR LOW PRES DRIFTS ACRS THE
REGION.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
RESTRICTIONS ARE POSSIBLE IN RAIN OR SNOW SHOWERS THROUGH FRIDAY.
BEST CHANCE FOR A RETURN TO WIDESPREAD VFR CONDITIONS MAY NOT ARRIVE
UNTIL LATE SAT/SUN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
429 PM EST WED FEB 27 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 426 PM EST WED FEB 27 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BROAD MID LEVEL LOW
CIRCULATION OVER THE GREAT LAKES/OHIO VALLEY. AT THE SFC...A
WEAKENING LOW PRES CENTER WAS LOCATED NEAR FLINT. SYSTEM ENDED UP
SLIGHTLY FARTHER N THAN EXPECTED YESTERDAY...AND THUS THE ASSOCIATED
WEAKENING SNOW SHIELD WAS ABLE TO SPREAD FARTHER N AND W INTO UPPER
MI TODAY...AIDED BY A SHORTWAVE THAT PIVOTED AROUND THE LARGE MID
LEVEL LOW CIRCULATION. THE NW EDGE OF THE -SN HAS SPREAD TO ABOUT A
BIG BAY/CHAMPION/CRYSTAL FALLS LINE. SNOW ACCUMULATIONS HAVE
GENERALLY BEEN 1 INCH OR LESS THOUGH SOME 2-3 INCH AMOUNTS WERE
OBSERVED ACROSS MENOMINEE/DELTA/SRN SCHOOLCRAFT COUNTIES. SINCE THE
WEAKENING SHORTWAVE AND ASSOCIATED DEEP LAYER FORCING ASSOCIATED
WITH THE HEAVIER SNOW HAS ROTATED TO THE SW...-SN HAS BEEN
DIMINISHING IN AREAL COVERAGE FROM LATE MORNING THRU THE AFTN. AS
EXPECTED...THERE HAS NOT BEEN ANY EVIDENCE OF LES TODAY DESPITE
CYCLONIC NE FLOW AS AIR MASS HAS BEEN TOO WARM. IN FACT...ON VIS
SATELLITE IMAGERY...HIGH CLOUDS ARE AT TIMES THIN ENOUGH TO REVEAL
LITTLE IF ANY LAKE EFFECT CLOUDS OVER LAKE SUPERIOR. THE SNOW THAT
HAS RECENTLY INCREASED INTO NCNTRL UPPER MI APPEARS MOSTLY RELATED
TO A LONG ARC OF ISENTROPIC ASCENT EXTENDING W FROM NEW ENGLAND...
BUT IT CERTAINLY LOOKS LIKE THERE MAY NOW BE A LAKE COMPONENT TO
THIS HEAVIER SNOW THAT HAS DEVELOPED.
IN THE SHORT TERM...FOCUS SHIFTS FROM REMNANT -SN ASSOCIATED WITH
SLOWLY DEPARTING GREAT LAKES/OHIO VALLEY MID LEVEL LOW TO POTENTIAL
OF LES OFF LAKE SUPERIOR. WITH NO ADDITIONAL SHORTWAVES EVIDENT
PIVOTING TOWARD UPPER MI AND WITH MODELS INDICATING INCREASING DEEP
LAYER QVECTOR CONVERGENCE WITH TIME...EXPECT LINGERING AREAS OF -SN
OVER ROUGHLY THE E HALF OF UPPER MI TO CONTINUE TO DIMINISH TONIGHT.
ANY ADDITIONAL SNOW ACCUMULATION WILL BE LESS THAN 1 INCH.
ATTENTION THEN TURNS TO POTENTIAL LES OFF LAKE SUPERIOR. HIGHER RES
MODEL GUIDANCE CONTINUES TO POINT TOWARD LES/UPSLOPE ENHANCED SNOW
TONIGHT. ALTHOUGH DEEPER MOISTURE/SATURATION AND SYNOPTIC -SN IS
SPREADING OUT OVER ERN LAKE SUPERIOR...HAVE DOUBTS ON THE INSISTENCE
OF HIGH RES GUIDANCE TO OUTPUT IN WHAT SOME CASES ARE SIGNIFICANT
PCPN TOTALS TONIGHT (REGIONAL GEM SHOWS AROUND 0.5 INCHES OF PCPN
TONIGHT OVER THE HIGHER TERRAIN OF MARQUETTE COUNTY...LOCAL HIGH
RESWRF 0.3-0.4...06Z NAM SHOWED UPWARDS OF 1 INCH BUT 12Z NAM AT
LEAST TRENDED DOWN TO WHAT SHOULD BE A MORE REASONABLE 0.2-0.3).
850MB TEMPS OF ONLY -6 TO -9C ACROSS LAKE SUPERIOR WILL NOT BE
SUFFICIENT FOR LES. SO...ONCE THE ISENTROPIC ASCENT CURRENTLY AIDING
THE SNOW INTO NCNTRL UPPER MI FALLS APART TONIGHT...EXPECT THE SNOW
TO DIMINISH SIGNIFICANTLY. WILL THUS CARRY HIGH POPS INTO NCNTRL
UPPER MI THIS EVENING...THEN DIMINISH PCPN TO JUST SCT -SHSN
OVERNIGHT. EXPECT A FEW INCHES OF SNOW ACCUMULATION THRU THE EVENING
ACROSS THE HIGHER TERRAIN OF THE NCNTRL (MARQUETTE COUNTY IN
PARTICULAR). IF THE ONGOING SNOW SHOWS SIGNS OF PERSISTENCE AND
LITTLE MOVEMENT (HEAVIEST SNOW IS CURRENTLY OCCURRING FROM
MARQUETTE/HARVEY WSW TO ISHPEMING/GWINN) WILL LIKELY NEED TO HOIST
AN ADVY. FARTHER W...LACKING SYNOPTIC FORCING...NOTHING MORE THAN
DEVELOPING CHC POPS/SCT -SHSN APPEAR REASONABLE.
850MB TEMPS FALL ANOTHER DEGREE OR TWO THU...BUT EVEN THAT WILL
STILL NOT BE QUITE COLD ENOUGH FOR LES. WITH ANY DEEPER MOISTURE
EXITING AND SINCE THERE WILL PROBABLY BE SOME NEGATIVE IMPACT DUE TO
DAYTIME HEATING WITH HIGHER SUN ANGLE AT THIS TIME OF YEAR...SCT
-SHSN OFF THE LAKE SHOULD WIND DOWN DURING THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 426 PM EST WED FEB 27 2013
PREFERRED THE 00Z/27 ECMWF AND GLOBAL GEM OVER THE 12Z/27 GFS FOR
THE ENTIRE LONG TERM SINCE THE GFS HAS DISPLAYED POOR RUN TO RUN
CONTINUITY AND LACKS AGREEMENT WITH OTHER MODELS.
KEPT DIMINISHING CHANCES OF LAKE EFFECT SNOW THU NIGHT INTO EARLY
FRI IN AREAS FAVORED BY NE LOW LEVEL WINDS...BUT PUSHED BACK WHEN
POPS GO AWAY ENTIRELY BY AROUND 3 HOURS TO 18Z FRI. AFTER
THAT...VERY DRY LOW LEVELS ASSOCIATED WITH A SFC AND 500MB RIDGE
PUSHING INTO THE CWA. LOW LEVEL FLOW WILL CONTINUE TO BE OUT OF THE
N/NE UNTIL THE SFC RIDGE AXIS COMPLETELY PASSES SUN NIGHT WITH
SLIGHTLY COLDER 850MB TEMPS...SO WILL KEEP INCREASED CLOUD COVER NEAR
LAKE SUPERIOR. MAY SEE A BRIEF RETURN OF NE FLOW LES LATE FRI NIGHT
WITH THE PASSAGE OF A 500MB TROUGH...BUT ANY ACCUMULATIONS WILL BE
MINOR.
THE STORY FOR SUN THROUGH NEXT WED IS THAT A 500MB LOW WILL MOVE
OVER THE CWA THROUGH TUE BEFORE MOVE S ON WED. AT THE SAME
TIME...INCREASINGLY STRONG SFC RIDGING WILL MOVE INTO THE CWA...SO
PRECIP WILL BE AT A MINIMUM. PRECIP...IF ANY...WILL BE MINOR SO
SLIGHT CHANCE POPS AT BEST SEEM APPROPRIATE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1238 PM EST WED FEB 27 2013
GUSTY N/NE WINDS WILL BE THE RULE AT KIWD/KCMX/KSAW THRU THIS FCST
PERIOD AS TIGHT PRES GRADIENT REMAINS IN PLACE ACROSS THE UPPER GREAT
LAKES. WIND DIRECTION IS MOST FAVORABLE FOR ENHANCED WINDS AT
KSAW...AND GUSTS THERE SHOULD BE IN THE 20-30KT RANGE THROUGHOUT THE
FCST PERIOD. AT KIWD...UPSLOPE N/NNE WINDS WILL LIKELY KEEP LOW MVFR
CIGS IN PLACE THRU THE FCST PERIOD. AS AIR MASS COOLS SLIGHTLY...
LAKE EFFECT -SHSN MAY GET UNDERWAY TONIGHT...BUT EXPECTATION IS FOR
ANY SHSN TO BE LIGHT AND NOT SIGNIFICANTLY REDUCE VIS. AT KCMX...LOW
CLOUDS HAVE SCATTERED OUT...BUT LOWER CLOUDS TO THE NE OF LAKE
SUPERIOR SHOULD ADVECT SW AND BRING A RETURN TO MVFR CIGS AT KCMX
LATE IN THE AFTN. MAY SEE A FEW FLURRIES LATER TONIGHT AT KCMX. AT
KSAW...IDEAL USPLOPE FLOW AND PERIODS OF -SN SHOULD RESULT IN IFR
CONDITIONS PREVAILING FOR THE NEXT SEVERAL HRS. SOME IMPROVEMENT TO
LOW MVFR SHOULD OCCUR LATE AFTN WITH LOW MVFR CONDITIONS CONTINUING
THRU THU MORNING UNDER UPSLOPE NORTHERLY FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 426 PM EST WED FEB 27 2013
TIGHT PRES GRADIENT BTWN HIGH PRES TO THE N AND NW AND LOW PRES
TRACKING THRU THE LWR LAKES WILL RESULT IN NORTHEASTERLY WINDS OF
20-30KT ACROSS LAKE SUPERIOR THRU THU. GALE FORCE GUSTS SHOULD BE
FREQUENT ENOUGH TO MAINTAIN GALE WARNING FOR THE E HALF OF LAKE
SUPERIOR. IN ADVANCE OF HIGH PRES RIDGE BUILDING TOWARD THE AREA
FRI...TIGHT PRES GRADIENT WILL REMAIN...RESULTING IN CONTINUED
20-30KT NE WINDS. THE STRONG WINDS/HIGH WAVES AND INFLUX OF COLDER
AIR WILL RESULT IN FREEZING SPRAY DEVELOPING TONIGHT AND CONTINUING
THRU FRI NIGHT. HVY FREEZING SPRAY MAY OCCUR FOR A TIME THU
NIGHT/FRI MORNING. WINDS WILL THEN DIMINISH FROM W TO E FRI NIGHT AS
HIGH PRES RIDGE MOVES CLOSER. ON SAT...WINDS SHOULD BE BLO 20KT
ACROSS THE ENTIRE LAKE. LIGHT WINDS...MOSTLY 10KT OR LESS...ARE
EXPECTED SUN/MON AS SFC HIGH PRES RIDGE WILL EXTEND FROM HUDSON BAY
S ACROSS THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THURSDAY FOR LSZ244-245-248>250-
264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
249 PM CST WED FEB 27 2013
.DISCUSSION...
STACKED LOW PRESSURE SYSTEM OVER THE EASTERN GREAT LAKES WILL
CONTINUE TO SPONSOR CLOUDS OVER THE LOCAL FORECAST AREA ON ITS
WESTERN PERIPHERY...ALONG WITH WEAK LIFT OVER WEST CENTRAL WI.
HAVE INCLUDED HIGH POPS OVER WEST CENTRAL WI THIS EVENING. HAVE ALSO
INCLUDED A MENTION OF SCATTERED FLURRIES FROM WEST INTO SOUTH
CENTRAL MN WHERE WEAK FRONTOGENESIS IS PROGGED FROM 700-600MB
TONIGHT INTO THURSDAY MORNING.
DESPITE THE EXTENSIVE CLOUD COVER...TEMPS HAVE WARMED INTO THE
UPPER 20S TO UPPER 30S NEARLY CWA-WIDE TODAY. CLOUDS AND WINDS
HOLD TIGHT TONIGHT...SO THINK MOS NUMBERS APPEAR TOO COLD. HAVE
LEANED TOWARD THE BIAS CORRECTED MOS...WHICH YIELDS UPPER TEENS TO
UPPER 20S FOR LOWS TONIGHT.
THURSDAY THROUGH SUNDAY WILL BE RATHER BENIGN LOCALLY...AS THE
AREA REMAINS WEDGED BETWEEN A NORTHEASTERN CONUS TROUGH AND A
BROAD WESTERN RIDGE. NORTHERLY FLOW WILL KEEP TEMPERATURES ON THE
COOL SIDE OF NORMAL THROUGH THE WEEKEND HOWEVER...WITH HIGHS
GENERALLY RUNNING 5 TO 10 DEGREES BELOW CLIMATOLOGY FOR EARLY
MARCH. SINGLE DIGIT LOWS APPEAR LIKELY FOR THE MAJORITY OF THE
FORECAST AREA ON BOTH WEEKEND MORNINGS AS WELL.
THE 12Z SUITE OF MODELS TRENDED TO A SCENARIO MORE FAVORABLE FOR
SNOWFALL IN CENTRAL/SOUTHERN MN...NAMELY THE ECMWF WHICH HAD BEEN
THE MOST OPPOSED PRIOR TO TODAY. IT NOW TRACKS A SURFACE LOW
ACROSS SOUTH DAKOTA AND IOWA...WITH A PROLONGED PERIOD OF
MEASURABLE SNOWFALL FROM WEST INTO SOUTH CENTRAL MN. WHILE MODELS
ARE STILL NOTABLY VARIABLE REGARDING THE TRACK/AMPLITUDE OF THIS
TROUGH...THE RECENT CHANGE OF THE ECMWF HAS INCREASED CONFIDENCE
FOR AT LEAST MEASURABLE SNOW LOCALLY. HAVE THEREFORE INCREASED
POPS TO 50-60 PERCENT FOR WEST/SOUTH CENTRAL MN ON MONDAY AND
MONDAY NIGHT...WITH 20-40S FROM CENTRAL MN INTO WEST CENTRAL WI.
REGARDING TEMPERATURES IN THE EXTENDED...HIGHS SHOULD GENERALLY
RANGE AROUND 5 DEGREES BELOW NORMAL FROM MONDAY THROUGH THE MIDDLE
OF NEXT WEEK...WITH LOWS A FEW DEGREES ON EITHER SIDE OF NORMAL.
&&
.AVIATION.../18Z TAF ISSUANCE/
TERMINALS WILL BE UNDER THE INFLUENCE OF EXPANSIVE VERTICALLY
STACKED AND OCCLUDED LOW NOW NEAR DETROIT THIS ENTIRE TAF PERIOD.
FOR THESE TAFS...FAVORED THE RAP HEAVILY...BLENDED A BIT WITH LAMP
GUIDANCE. THE 925 MB RAP RH HAS BEEN PERFORMING WELL WITH ERODING
OUT WEST END OF MVFR CIGS ACROSS ERN MN. THE RAP HAS BEEN
CONSISTENT WITH PUSHING THESE CIGS EAST THROUGH THE
MORNING...BEFORE QUICKLY BRINGING THIS MOISTURE SOUTHWEST ACROSS
THE REST OF THE MPX CWA THIS AFTERNOON. FOR BRINGING CIGS BACK IN
TO RWF/AXN/STC...BLENDED RAP TIMING IN WITH THE SLOWER LAMP
GUIDANCE...THOUGH DID FAVOR THE RAP. ONCE THESE CLOUDS MOVE
IN...HEIGHTS SHOULD BE FAIRLY CONSISTENT THE REST OF THE TAF
PERIOD...WITH NO SIGNS OF SIGNIFICANT CLEARING WORKING INTO THE
MPX AREA UNTIL CLOSER TO 00Z...OR LATE THU AFTERNOON. BESIDE
CLOUDS...ALSO SEEING A BAND OF MAINLY MVFR SNOW ACROSS CENTRAL WI
SLOWLY WORKING WEST. HRRR REFLECTIVITY FORECAST HAS HAD A GOOD
HANDLE ON THIS SNOW THIS MORNING...SO FOLLOWED IT FOR TIMING SNOW
ACROSS WRN WI. WILL START OFF EAU WITH -SN...WITH THE EXPECTATION
THAT SNOW SHOULD BREAK OUT THERE BY 1830Z. MAINLY MVFR VIS
RESTRICTIONS ARE EXPECTED...THOUGH WITH THE OCCASIONAL IFR VIS
EAST OF EAU...DID KEEP A TEMPO IFR GROUP FOR A BIT THIS AFTERNOON.
THIS SNOW WILL LIKELY GRAZE RNH AND STAY SE OF MSP...THOUGH MAY
IMPACT FIELD SUCH AS K21D AND KSGS. FOR WINDS...NOT EXPECTING MUCH
VARIATION IN DIRECTION THIS PERIOD...WITH JUST AN EVERY SO GRADUAL
BACKING TOWARD THE NNW EXPECTED. WILL CONTINUE WITH GUSTS INTO
THIS EVENING...BUT THINGS LOOKS TO SETTLE DOWN TONIGHT...WITH NO
GUSTS EXPECTED TOMORROW WITH TYPICAL DIURNAL STRENGTHENING.
KMSP...RAP HAS BEEN PRETTY CONSISTENT WITH RETURN TO VFR CIGS
CURRENTLY OBSERVED. CONFIDENCE IS HIGH WE WILL RETURN TO AROUND 2K
FT CIGS..BUT THERE IS LESS CONFIDENCE ON WHEN THEY RETURN...WITH
IT POSSIBLY BEING CLOSER TO 00Z BEFORE GOING BACK TO MVFR. IN
ADDITION...BAND OF SNOW OUT BY EAU WILL MAKE A RUN FOR MSP...AND
BASED ON THE RAP/HRRR...MAY SEE A BRIEF SNOW SHOWER BETWEEN 00Z
AND 03Z...THOUGH CONFIDENCE IN THIS HAPPENING NOT HIGH ENOUGH TO
INCLUDE IN THE TAF ATTM. OTHER CONCERN THIS TAF PERIOD WILL BE
WITH CIG HEIGHTS. KEPT THEM ABOVE 017 FOR NOW...BUT CERTAINLY IS
POSSIBLE THAT CIGS COULD DROP TO AROUND 015 LATE TONIGHT INTO THU
MORNING. ANY IMPROVEMENTS BACK TO VFR NOT EXPECTED UNTIL NEAR THE
END OF OR SHORTLY AFTER THIS TAF PERIOD.
/OUTLOOK FOR KMSP/
FRI...VFR WITH MVFR CIGS POSSIBLE. N WIND 5-10 KTS.
SAT...VFR. N WIND 5 KTS.
SUN...VFR. SE WIND 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
LS/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1150 AM CST WED FEB 27 2013
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.PREV DISCUSSION.../ISSUED AT 356 AM CST WED FEB 27 2013/
OVERVIEW...ONLY MINOR ADJUSTMENTS TO POPS/WX/TEMPS WITH THE
MORNING FORECAST PACKAGE. LIGHT SNOW POSSIBLE IN WEST CENTRAL WI
THIS AFTERNOON AND EVENING. VERY LIGHT SNOW OR FLURRIES COULD MAKE
IT INTO FAR EASTERN MN...BUT KEPT THE TWIN CITIES METRO SNOW FREE
AT THIS POINT. WE REMAIN ON THE EASTERN FRINGE OF A CLIPPER SYSTEM
ON MONDAY.
PLENTY OF CLOUD COVER AT MULTIPLE LEVELS ACROSS MN/WI IN RESPONSE
TO LARGE TROUGH STRETCHING FROM THE ROCKIES TO THE EAST COAST.
THE CENTER OF THE LONG SINCE OCCLUDED CYCLONE IS LOCATED ALONG THE
MI/OH BORDER EARLY THIS MORNING...BUT THE WESTWARD EXTENSION OF
THE TROUGH IS STILL SPREADING MODERATE SNOW ACROSS WI AND IA. OUR
WESTERN CWA COULD EVEN GET IN ON SOME LIGHT SNOW LATE THIS MORNING
AND AFTERNOON. 27.00Z NAM IS PROBABLY THE MOST AGGRESSIVE WITH THE
WESTWARD PROPAGATION OF A 700-600 MB FGEN BAND AND OMEGA INTO WEST
CENTRAL WI. ASSORTED SHORT-RANGE MODEL GUIDANCE...SUCH AS THE
HRRR/RAP/HOP-WRF SHOW A BAND OF SYNTHETIC REFLECTIVITY MOVING INTO
WESTERN WI TODAY. AS A RESULT...INCREASED POPS IN A FEW OF OUR WI
COUNTIES...INCLUDING EAU CLAIRE. NOT SUPREMELY CONFIDENT IN
MEASURABLE SNOW...BUT A DUSTING IS PLAUSIBLE AND AS MUCH AS 1/2"
TO 3/4" IS CERTAINLY POSSIBLE. EVEN THE TWIN CITIES METRO COULD
SEE A FEW FLURRIES...ALTHOUGH LEFT THE FORECAST FOR MN MAINLY
WEATHER FREE TODAY AND TONIGHT.
THE SOUTHWARD EXTENT OF THE 0 C 850 MB ISOTHERM IS IMPRESSIVE OVER
THE NEXT SEVERAL DAYS. CURRENTLY...IT STRETCHES FROM ROUGHLY
NORTHERN CALIFORNIA...TO TEXAS...TO NORTHERN SOUTH CAROLINA. BY
THE WEEKEND THE COLD AIR COULD BE AS FAR SOUTH AS SOUTHERN
FLORIDA. WHILE THIS MEANS WELL-BELOW NORMAL TEMPERATURES FOR PARTS
OF THE COUNTRY...IT ACTUALLY REMAINS NEAR NORMAL FOR MN/WI. THERE
WILL HOWEVER BE A SLIGHTLY COOLING TREND LATE THIS WEEK AS
NORTHERLY FLOW KEEPS WEAK COLD AIR ADVECTION GOING FOR THE NEXT
FEW DAYS. THE COLDEST MORNING APPEARS TO BE SATURDAY MORNING WHERE
WE COULD SEE WIDESPREAD SINGLE DIGITS AND LOWER TEENS. IF WE COULD
GUARANTEE NO CLOUD COVER...THEN SOME SITES WOULD CERTAINLY BE
BELOW ZERO GIVEN THE SNOW COVER AND POSITION OF THE SURFACE PRESSURE
RIDGE.
BESIDES THE LIGHT SNOW IN WI TODAY...THE ONLY SIGNIFICANT CHANCE
FOR PRECIP IS WITH A SYSTEM DROPPING SOUTH OUT OF ALBERTA IN THE
MONDAY/TUESDAY TIME FRAME. THE LAST 4-5 RUNS OF THE GFS/ECMWF HAVE
GENERALLY TRENDED WEST WITH THE LOW TRACK...WITH A SLIGHT WOBBLE
HERE AND THERE. WOULD HAVE TO SAY THAT THERE IS DECENT AGREEMENT
BETWEEN THE GEM/GFS/ECMWF/FIM WITH THE SYSTEM EARLY NEXT WEEK. ALL
SOLUTIONS WOULD EITHER FAVOR A MUCH BETTER CHANCE FOR LIGHT SNOW
IN WESTERN MN...OR BEND MOST OF THE PRECIP AROUND THE FORECAST
AREA ALL TOGETHER. VIEWING ALL THE GEFS MEMBERS INDIVIDUALLY...
THERE SEEMS TO ONE TIGHTER CLUSTERING OF LOW TRACKS THAT ARE
SIMILAR TO THE OPERATIONAL 27.00Z GFS. ALTHOUGH...THERE ARE STILL
SEVERAL MEMBERS WITH A MORE EASTERLY SOLUTION...SO THE ENSEMBLE
MEAN IS THEREFORE A BIT FARTHER EAST THAN THE 00Z GFS. RIGHT NOW
THE AXIS OF HEAVIEST QPF FALLS IN THE DAKOTAS AND/OR NORTHERN
NE...WITH 0.30-0.40"...WHICH WOULD BE GOOD ENOUGH FOR A HIGH END
ADVISORY OR A LOW END WARNING. WE`LL HAVE TO WATCH TO SEE IF THERE
IS AN EASTWARD TREND WITH TIME. AT THIS POINT...THERE IS ONLY
ENOUGH CONFIDENCE IN SLIGHT CHANCE/CHANCE POPS.
&&
.AVIATION.../18Z TAF ISSUANCE/
TERMINALS WILL BE UNDER THE INFLUENCE OF EXPANSIVE VERTICALLY
STACKED AND OCCLUDED LOW NOW NEAR DETROIT THIS ENTIRE TAF PERIOD.
FOR THESE TAFS...FAVORED THE RAP HEAVILY...BLENDED A BIT WITH LAMP
GUIDANCE. THE 925 MB RAP RH HAS BEEN PERFORMING WELL WITH ERODING
OUT WEST END OF MVFR CIGS ACROSS ERN MN. THE RAP HAS BEEN
CONSISTENT WITH PUSHING THESE CIGS EAST THROUGH THE
MORNING...BEFORE QUICKLY BRINGING THIS MOISTURE SOUTHWEST ACROSS
THE REST OF THE MPX CWA THIS AFTERNOON. FOR BRINGING CIGS BACK IN
TO RWF/AXN/STC...BLENDED RAP TIMING IN WITH THE SLOWER LAMP
GUIDANCE...THOUGH DID FAVOR THE RAP. ONCE THESE CLOUDS MOVE
IN...HEIGHTS SHOULD BE FAIRLY CONSISTENT THE REST OF THE TAF
PERIOD...WITH NO SIGNS OF SIGNIFICANT CLEARING WORKING INTO THE
MPX AREA UNTIL CLOSER TO 00Z...OR LATE THU AFTERNOON. BESIDE
CLOUDS...ALSO SEEING A BAND OF MAINLY MVFR SNOW ACROSS CENTRAL WI
SLOWLY WORKING WEST. HRRR REFLECTIVITY FORECAST HAS HAD A GOOD
HANDLE ON THIS SNOW THIS MORNING...SO FOLLOWED IT FOR TIMING SNOW
ACROSS WRN WI. WILL START OFF EAU WITH -SN...WITH THE EXPECTATION
THAT SNOW SHOULD BREAK OUT THERE BY 1830Z. MAINLY MVFR VIS
RESTRICTIONS ARE EXPECTED...THOUGH WITH THE OCCASIONAL IFR VIS
EAST OF EAU...DID KEEP A TEMPO IFR GROUP FOR A BIT THIS AFTERNOON.
THIS SNOW WILL LIKELY GRAZE RNH AND STAY SE OF MSP...THOUGH MAY
IMPACT FIELD SUCH AS K21D AND KSGS. FOR WINDS...NOT EXPECTING MUCH
VARIATION IN DIRECTION THIS PERIOD...WITH JUST AN EVERY SO GRADUAL
BACKING TOWARD THE NNW EXPECTED. WILL CONTINUE WITH GUSTS INTO
THIS EVENING...BUT THINGS LOOKS TO SETTLE DOWN TONIGHT...WITH NO
GUSTS EXPECTED TOMORROW WITH TYPICAL DIURNAL STRENGTHENING.
KMSP...RAP HAS BEEN PRETTY CONSISTENT WITH RETURN TO VFR CIGS
CURRENTLY OBSERVED. CONFIDENCE IS HIGH WE WILL RETURN TO AROUND 2K
FT CIGS..BUT THERE IS LESS CONFIDENCE ON WHEN THEY RETURN...WITH
IT POSSIBLY BEING CLOSER TO 00Z BEFORE GOING BACK TO MVFR. IN
ADDITION...BAND OF SNOW OUT BY EAU WILL MAKE A RUN FOR MSP...AND
BASED ON THE RAP/HRRR...MAY SEE A BRIEF SNOW SHOWER BETWEEN 00Z
AND 03Z...THOUGH CONFIDENCE IN THIS HAPPENING NOT HIGH ENOUGH TO
INCLUDE IN THE TAF ATTM. OTHER CONCERN THIS TAF PERIOD WILL BE
WITH CIG HEIGHTS. KEPT THEM ABOVE 017 FOR NOW...BUT CERTAINLY IS
POSSIBLE THAT CIGS COULD DROP TO AROUND 015 LATE TONIGHT INTO THU
MORNING. ANY IMPROVEMENTS BACK TO VFR NOT EXPECTED UNTIL NEAR THE
END OF OR SHORTLY AFTER THIS TAF PERIOD.
/OUTLOOK FOR KMSP/
FRI...VFR WITH MVFR CIGS POSSIBLE. N WIND 5-10 KTS.
SAT...VFR. N WIND 5 KTS.
SUN...VFR. SE WIND 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/MPG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
322 PM CST WED FEB 27 2013
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
321 PM CST WED FEB 27 2013
AT 3 PM...A LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTHERN LOWER
MICHIGAN. CYCLONIC FLOW AROUND THIS LOW HAS KEPT CLOUDS AND LIGHT
SNOW ACROSS MUCH OF THE FORECAST AREA TODAY.
FOR TONIGHT...THE 27.00Z MODELS ARE IN GOOD AGREEMENT THAT A
SHORT WAVE ROTATING AROUND THE UPPER LEVEL LOW WILL MOVE WEST
SOUTHWEST ACROSS AREA THIS EVENING. THIS SYSTEM WILL PRODUCE
AROUND 4 MICROBAR/SEC OF OMEGA BELOW 10K FEET THIS EVENING. THIS
LIFT IS CO-LOCATED WITH THE DEEP MOISTURE. THE DEEPEST LIFT IS
FOUND ACROSS EASTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA.
AS A RESULT...RAISED THE PRECIPITATION PROBABILITIES TO
90 PERCENT IN THESE AREAS. SOUNDINGS ARE COLD ENOUGH THAT THE
PRECIPITATION WILL BE IN THE FORM OF SNOW. UNLIKE THIS
AFTERNOON WHERE THE SNOW HAD A HARD TIME ACCUMULATING DUE TO THE
HIGH SOLAR ANGLE...EXPECT SOME LIGHT ACCUMULATIONS /UP TO A HALF
INCH/ TO OCCUR THIS EVENING.
WITH CLOUDS REMAINING ACROSS THE REGION AND NO COLD AIR ADVECTION
COMING INTO THE AREA...STAYED CLOSE TO THE LOW TEMPERATURES WHICH
OCCURRED THIS MORNING.
ON THURSDAY...THE CYCLONIC FLOW REMAINS ACROSS THE REGION. THE
BUFKIT SOUNDINGS CONTINUE TO SHOW SOME WEAK OMEGA BELOW 5K. DUE TO
THIS...INTRODUCED FLURRIES TO THE FORECAST. THIS LIFT MAY BE UNDER
DONE IN THE MODELS BECAUSE THERE APPEARS TO BE A WEAK SHORT WAVE
IN THE 700 AND 500 MB WIND FIELDS. IF THIS IS THE CASE...THE
PRECIPITATION CHANCES WILL LIKELY HAVE TO BE INCREASED.
FROM THURSDAY NIGHT INTO FRIDAY NIGHT...HIGH PRESSURE WILL PROVIDE DRY
WEATHER. TEMPERATURES WILL AVERAGE A FEW DEGREES BELOW NORMAL.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
321 PM CST WED FEB 27 2013
A WEAK TO MODERATE STRATOSPHERIC WARMING EVENT IN THE GULF OF
ALASKA WILL HELP THE ARCTIC OSCILLATION TO BECOME INCREASING
NEGATIVE /DROPPING TO -4/ THROUGH EARLY NEXT WEEK. AS A RESULT...
THE 500 MB FLOW PATTERN WILL BE A POSITIVE PACIFIC NORTH AMERICAN
/PNA/ TELECONNECTION. THIS WILL KEEP OUR AREA IN NORTHWEST FLOW
THROUGH AT LEAST TUESDAY. THE COLDEST 850 MB ANOMALIES /-3.5
STANDARD DEVIATIONS/ ASSOCIATED WITH THE EASTERN TROUGH WILL BE
FOUND ACROSS THE SOUTHEAST UNITED STATES. MEANWHILE IN OUR
AREA...THE 850 MB TEMPERATURE ANOMALIES ARE JUST A BIT BELOW
NORMAL.
FROM MONDAY INTO MONDAY NIGHT...THE 27.12Z GEM...GFS...AND ECMWF
ARE COMING TO SOME CONSENSUS THAT A LOW PRESSURE SYSTEM WILL MOVE
SOUTHEAST ACROSS THE DAKOTAS AND IOWA. THIS TRACK WOULD BRING SOME
SNOW TO THE AREA. THIS SYSTEM HAS BEEN FAIRLY CONSISTENT IN THE
GFS FOR THE PAST 3 RUNS. MEANWHILE THE ECMWF HAS SHOWED VERY
LITTLE RUN TO RUN CONSISTENCY. DUE TO THE GFS CONSISTENCY...
TRENDED THE FORECAST TOWARD IT AND RAISED THE PRECIPITATION
PROBABILITIES ABOUT 10 TO 20 PERCENT OVER THE ALL BLEND.
BEYOND THIS TIME PERIOD...THE ARE SIGNS IN BOTH THE GFS AND ECMWF
THAT THE 500 MB PATTERN WILL MAKE A DRAMATIC SHIFT IN THE 500 MB
PATTERN AS A STRONG 500 MB RIDGE DEVELOPS ACROSS THE CENTRAL
UNITED STATES. THE ECMWF HAS A MUCH STRONGER RIDGE THAN THE GFS. AS A
RESULT...ITS 850 MB TEMPERATURE ANOMALIES ARE STANDARD DEVIATION
ARE UP TO 2 ACROSS THE DAKOTAS BY WEDNESDAY. THERE IS ACTUALLY
SUPPORT FOR IN THE PACIFIC AS THE MADDEN JULIAN OSCILLATION MOVES
FROM PHASE 6 TO PHASE 7. BOTH OF THESE PHASES...SUPPORT WARMTH
ACROSS THE EASTERN HALF OF THE CONUS.
&&
.AVIATION...THROUGH 18Z THURSDAY
1142 AM CST WED FEB 27 2013
MAIN AVIATION CONCERNS ARE MVFR CONDITIONS AT BOTH TAF SITES AND
BREEZY NORTHERLY WINDS AT RST THROUGH TAF PERIOD. LATEST WATER
VAPOR SATELLITE IMAGERY INDICATING SEVERAL SHORTWAVE TROUGHS
ROTATING AROUND UPPER LEVEL LOW PRESSURE OVER THE OHIO RIVER
VALLEY. THE UPPER LEVEL LOW IS EXPECTED TO CONTINUE TO ROTATE LOW LEVEL
MOISTURE INTO THE REGION...ESPECIALLY INTO TONIGHT. LATEST 17Z METARS
INDICATE MVFR CONDITIONS AT BOTH RST AND LSE TAF SITES. THE
LATEST 27.12Z NAM AND 27.15Z RAP SHOW LOW LEVEL MOISTURE TO
SLOWLY DIMINISH OUT OF THE REGION AFTER 12Z THURSDAY.
HOWEVER...WITH REGION UNDER THE INFLUENCE OF THE UPPER LEVEL LOW
OVER THE OHIO RIVER VALLEY...CONFIDENCE IS NOT VERY HIGH THE TAF
SITES WILL COMPLETELY CLEAR OUT OF BROKEN CEILINGS/MVFR CONDITIONS BY 12Z
THURSDAY. HAVE KEPT MVFR CONDITIONS THROUGH THE TAF PERIOD. TIGHT
PRESSURE GRADIENT ON BACKSIDE OF SURFACE LOW OVER SOUTHERN
MICHIGAN WILL ALLOW SUSTAINED WIND SPEEDS OF 15 TO 18 KNOTS AND
GUST 20 TO 25 KNOTS AT RST THROUGH 03Z THURSDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
321 PM CST WED FEB 27 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1142 AM CST WED FEB 27 2013
.SHORT TERM...
1142 AM CST WED FEB 27 2013
LATEST RADAR TRENDS HAVE SHOWN SNOW BANDS WEAKENING AND MOVING
OUT OF THE ADVISORY AREA. WITH TEMPERATURES WARMING INTO THE LOWER
TO MIDDLE 30S OVER THE SOUTHWEST WISCONSIN AND NORTHEAST
IOWA...WILL MITIGATE ANY SNOWFALL ACCUMULATION ON ROADWAYS THIS
AFTERNOON. THEREFORE...WILL LET THE WINTER WEATHER ADVISORY EXPIRE
AT NOON TODAY FOR SOUTHWEST WISCONSIN AND NORTHEAST IOWA.
.LONG TERM...SATURDAY THROUGH TUESDAY
306 AM CST WED FEB 27 2013
MEDIUM RANGE MODEL RUNS OF 27.00Z IN REASONABLE AGREEMENT WITH EACH
OTHER AND THEIR PREVIOUS RUNS FOR THE AREA TO BE UNDER NORTHWEST TO
NORTH FLOW ALOFT THRU THE WEEKEND AND BULK OF ANY SHORTWAVE ENERGY
DROPPING THRU THE FLOW REMAINING WEST OF THE AREA. FCST FOR SAT/SUN
REMAINS DRY WITH TEMPS A CATEGORY OR TWO BELOW THE NORMALS AS MARCH
BEGINS. BETWEEN MODEL CONSISTENCY IMPROVING FOR MON/TUE WITH
BREAKDOWN OF THE WESTERN NOAM RIDGE AS A RATHER STRONG SHORTWAVE
MOVES THRU THE NORTHERN ROCKIES SUN THEN ACROSS THE CENTRAL PLAINS
MON INTO THE MID MS VALLEY TUE. THIS TRENDS SOUTH/WEST WITH THE
SHORTWAVE FROM THE EARLIER RUNS. MODEL CONSENSUS CONTINUES A -SN
CHANCE ACROSS MUCH OF THE AREA MON INTO TUE BUT CONFIDENCE FOR THIS
ON DAYS 6/7 NOT HIGH GIVEN THE TREND/SHIFT OF THE SHORTWAVE ENERGY
TO THE SOUTHWEST. IF THE TREND CONTINUES FOR ANOTHER CYCLE...APPEARS
MON-TUE WILL NEED TO BE SHIFTED TO A DRY FCST. NOT A LOT OF
CONFIDENCE IN THE DAY 6/7 PERIOD AT THIS TIME AND LEFT THE 27.00Z
MODEL/ENSEMBLE CONSENSUS DATA IN THE FCST GRIDS AS IS FOR NOW. WITH
A SHIFT BACK TO A MORE WESTERLY FLOW FOR EARLY NEXT WEEK...TEMPS
RETURNING TO NEAR NORMAL FOR MON/TUE LOOK WELL TRENDED.
&&
.AVIATION...THROUGH 18Z THURSDAY
1142 AM CST WED FEB 27 2013
MAIN AVIATION CONCERNS ARE MVFR CONDITIONS AT BOTH TAF SITES AND
BREEZY NORTHERLY WINDS AT RST THROUGH TAF PERIOD. LATEST WATER
VAPOR SATELLITE IMAGERY INDICATING SEVERAL SHORTWAVE TROUGHS
ROTATING AROUND UPPER LEVEL LOW PRESSURE OVER THE OHIO RIVER
VALLEY. THE UPPER LEVEL LOW IS EXPECTED TO CONTINUE TO ROTATE LOW LEVEL
MOISTURE INTO THE REGION...ESPECIALLY INTO TONIGHT. LATEST 17Z METARS
INDICATE MVFR CONDITIONS AT BOTH RST AND LSE TAF SITES. THE
LATEST 27.12Z NAM AND 27.15Z RAP SHOW LOW LEVEL MOISTURE TO
SLOWLY DIMINISH OUT OF THE REGION AFTER 12Z THURSDAY.
HOWEVER...WITH REGION UNDER THE INFLUENCE OF THE UPPER LEVEL LOW
OVER THE OHIO RIVER VALLEY...CONFIDENCE IS NOT VERY HIGH THE TAF
SITES WILL COMPLETELY CLEAR OUT OF BROKEN CEILINGS/MVFR CONDITIONS BY 12Z
THURSDAY. HAVE KEPT MVFR CONDITIONS THROUGH THE TAF PERIOD. TIGHT
PRESSURE GRADIENT ON BACKSIDE OF SURFACE LOW OVER SOUTHERN
MICHIGAN WILL ALLOW SUSTAINED WIND SPEEDS OF 15 TO 18 KNOTS AND
GUST 20 TO 25 KNOTS AT RST THROUGH 03Z THURSDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1142 AM CST WED FEB 27 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....RRS
AVIATION...DTJ