Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/22/13
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
230 PM MST WED FEB 20 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 230 PM MST WED FEB 20 2013
GOOD MODEL AGREEMENT WITH SMALL AND LARGE SCALE FEATURES ADDING TO
FORECAST CONFIDENCE. THE MAIN UPPER LOW TRACKING THROUGH SOUTHERN
ARIZONA THIS AFTERNOON MOVES SOUTHERN NEW MEXICO TONIGHT AND INTO
KANSAS ON THURSDAY. A SECOND CENTER TO THE LOW TRACKS THROUGH
NORTHERN NEW MEXICO THIS EVENING. CURRENTLY SATELLITE SHOWS THREE
ENHANCED W-E ORIENTED BANDS OF ENHANCED CLOUDS OFF THE NE SIDE OF
THE LOW. THE SECOND BAND IS OVER SE UT-SW CO PRODUCING WIDESPREAD
SNOW. THE THIRD BAND IS OVER THE NORTHERN CWA AND APPARENTLY LACKS
SUFFICIENT LOW-MID LEVEL MOISTURE OR FORCING TO PRODUCE SNOW. JET
SUPPORT REMAINS WELL SOUTH OF THE FORECAST AREA AND SYNOPTIC
FORCING SPREADS ACROSS THE REGION THIS AFTERNOON AND EVENING BUT
IS STRONGEST SOUTH.
THIS AFTERNOON BEST SNOW ACCUMULATIONS HAVE OCCURRED IN PAGOSA
TOWARDS WOLF CREEK PASS WHERE THE FORCING...MOISTURE...AND
MARGINAL INSTABILITY ALL BULLSEYE. MAINLY SOUTH OROGRAPHIC
SNOWFALL CONTINUES ELSEWHERE FAVORING THE SOUTH-FACING SLOPES.
THIS EVENING THE 18Z RAP AND NAM INDICATE ENHANCED SNOWFALL UNDER
A MID LEVEL CIRCULATION OVER THE WEST ELK MOUNTAINS SOUTHWARD INTO
THE HIGHWAY 50 CORRIDOR THROUGH THE GUNNISON BASIN. THE LOW LEVEL
CONVERGENCE SHIFTS EAST OF THE FORECAST AREA AFTER MIDNIGHT WITH
SNOW ACCUMULATION SHIFTING TO NW-FACING SLOPES INCLUDING THE SKI
AREAS. THIS WILL FAVOR THE CENTRAL MOUNTAINS INTO THURSDAY.
AREAS OF LESS CERTAINTY INCLUDE THE MOUNTAINS OF EASTERN UTAH
WHERE MODELS STRUGGLE TO PRODUCE ADVISORY LEVEL SNOW ACCUMULATION.
MONTROSE MAY GET UP TO 4 INCHES OF SNOWFALL AS THE FLOW TURNS TO
NW/UPVALLEY. CORTEZ HAS BEEN JUST ABOVE FREEZING THIS AFTERNOON
BUT EXPECT THE FOOTHILLS FROM MANCOS TO DOVE CREEK TO SEE
ACCUMULATIONS CONTINUING THIS EVENING.
IN NW FLOW LIGHT SNOWFALL CONTINUES OVER THE COLORADO SPINE
THROUGH THURSDAY BUT DIMINISHES THURSDAY NIGHT. ALL HIGHLIGHTS END
THURSDAY AFTERNOON AND THIS STILL SEEMS REASONABLE EVEN WITH SNOW
CONTINUING AS ACCUMULATIONS ARE PROGGED TO BE VERY LIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 230 PM MST WED FEB 20 2013
A RATHER ILL-DEFINED SECONDARY UPPER TROUGH DROPS SOUTHEAST ACROSS
THE FORECAST AREA FRI BUT IS BOLSTERED BY A TRAILING JET MAX THAT
QUICKLY CATCHES IT FRI AFTERNOON. MOISTURE CONTENT DECREASES AND
LAPSE RATES BECOME MORE STABLE...BUT OROGRAPHICS IN THE PERSISTENT
NW FLOW AND WEAK DYNAMICS WITH THE TROUGH SHOULD PROVIDE ENOUGH
LIFT TO KEEP LIGHT SNOW OVER PARTS OF THE NRN MTNS FRIDAY FOR 1-3
INCHES OF NEW SNOW IN PLACES. HAVE BUMPED POPS UP A BIT FRI AS A
RESULT.
TRANSIENT SHORTWAVE RIDGING AND STABLE WARM ADVECTION ALOFT WILL
PROVIDE A LULL IN THE ACTIVITY FRIDAY NIGHT AS THE NEXT PACIFIC
STORM PUSHES INTO WA/OR. THIS STORM LOOKS TO BRING AN ENERGETIC
COLD FRONT INTO NE UT ABOUT MIDDAY SATURDAY AND THEN SOUTHEAST
ACROSS WRN CO SAT AFTERNOON/EVENING. CONFIDENCE IS HIGH AS MODELS
HAVE BEEN CONSISTENT WITH EACH OTHER AND FROM RUN TO RUN. WHILE
MOISTURE CONTENT DECREASES AS THE STORM CROSSES THE INTERIOR
WEST...STRONG FRONTOGENETIC AND DYNAMIC FORCING WITH UNSTABLE
700-500 MB LAPSE RATES COULD STILL LEAD TO A BURST OF MODERATE TO
PERHAPS HEAVY SNOW WITH THE FRONT...WHICH MAY BE COMPOUNDED BY WINDY
CONDITIONS AND BLOWING SNOW OVER THE HIGHER TERRAIN. COLD ADVECTION
IN N TO NW FLOW BEHIND THE FRONT SHOULD KEEP SNOW OVER THE MTNS SAT
NIGHT. WINTER HIGHLIGHTS MAY BE NEEDED FOR THIS STORM. A CHANCE OF
SNOW WILL CONTINUE SUNDAY WITH THE NORTHERN MTNS FAVORED IN NW FLOW.
AFTER ANOTHER LULL ON MONDAY...THE NEXT PACIFIC STORM SHOULD REACH
OUR AREA ABOUT TUE EVENING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 230 PM MST WED FEB 20 2013
IFR/VIFR CONDITIONS REPORTED OVER KCEZ KDRO KPSO THAT WILL
CONTINUE THROUGH TONIGHT IN WIDESPREAD SNOW SHOWERS. VFR
CONDITIONS IN THE CENTRAL VALLEYS WILL DETERIORATE THIS EVENING AS
SNOW SPREADS NORTHWARD. MOUNTAIN OBSCURATIONS WILL BE WIDESPREAD
ALONG AND SOUTH OF I-70 THROUGH THURSDAY. LOWERED FLIGHT CRITERIA
IN THE MVFR TO IFR RANGE CAN BE EXPECTED AT THE KRIL...KMTJ...KASE
AND KEGE TERMINALS WITH SNOW AND LOW CIGS LIKELY. THE KVEL AND
KGJT TERMINALS WILL BE ON THE EDGE AND OF THE HEAVIER
PRECIPITATION AND VFR CONDITIONS ARE FORECAST TO PREVAIL...THOUGH
SHOWERS IN THE VICINITY OF THESE TERMINALS CAN BE EXPECTED. THE
SOUTHERN AIRPORTS WILL SEE IMPROVING CONDITIONS THROUGH THURSDAY
AFTERNOON.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL NOON MST THURSDAY FOR COZ014.
WINTER WEATHER ADVISORY UNTIL 6 PM MST THURSDAY FOR COZ003-009-
010-012-013-017>019.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 6 PM MST
THURSDAY FOR COZ007-008.
WINTER WEATHER ADVISORY UNTIL 3 AM MST THURSDAY FOR COZ021-022.
WINTER STORM WARNING UNTIL 9 AM MST THURSDAY FOR COZ023.
UT...WINTER WEATHER ADVISORY UNTIL NOON MST THURSDAY FOR UTZ025-028.
&&
$$
SHORT TERM...JOE
LONG TERM...JAD
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
750 PM EST THU FEB 21 2013
.UPDATE (TONIGHT AND FRIDAY)...
00Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A CHAOTIC UPPER LEVEL
PATTERN IN PLACE OVER THE CONUS THIS EVENING. LONGWAVE TROUGH
COMPOSED OF SEVERAL LOBES OF ENERGY RESIDES OVER THE INTERMOUNTAIN
WEST AND CENTRAL PLAINS BEFORE THE FLOW RIDGES SHARPLY UP THE SPINE
OF THE APPALACHIANS BETWEEN THE TROUGH TO ITS WEST AND A CLOSED LOW
FEATURE OVER NEW ENGLAND/CANADIAN MARITIMES. THIS RIDGE WILL BROADEN
SOMEWHAT OVER THE NEXT 24 HOURS OVER THE EASTERN SEABOARD KEEPING
OUR LOCAL AREA AT ITS BASE. ANOTHER SHORTWAVE EJECTING AROUND THE
CENTRAL U.S. TROUGH WILL INTERACT WITH A QUASI-STATIONARY FRONTAL
BOUNDARY ACROSS THE SOUTHEASTERN STATES TO PRODUCE SIGNIFICANT
RAINFALL POTENTIAL FROM THE LOWER MS VALLEY EASTWARD ACROSS
AL/GA/AND THE FLORIDA PANHANDLE FROM FRIDAY INTO THE FIRST HALF OF
THE WEEKEND.
OUR LOCAL AREA WILL BE JUST FAR ENOUGH SOUTH AND EAST TO ENJOY THE
PROTECTION OF STACKED RIDGING THROUGH AT LEAST FRIDAY NIGHT.
FORECAST WILL CONTINUE TO ADVERTISE GENERALLY DRY CONDITIONS AND
ABOVE NORMAL TEMPERATURES...ESPECIALLY DURING THE DAYLIGHT HOURS.
OVERNIGHT LOW TEMPERATURES WILL ONLY DIP INTO THE MIDDLE 50S FOR THE
COLDER INTERIOR SPOTS...AND BE BACK UP IN THE LOW TO MID 80S AWAY
FROM THE COAST FOR FRIDAY AFTERNOON. THE RAPID DIURNAL SWING IN
TEMPERATURES WILL FORCE AN ONSHORE COMPONENT TO THE WINDS NEAR THE
COAST BY 1-2 PM ON FRIDAY...AND THIS WILL HELP KEEP BEACH TEMPS HELD
IN GENERALLY THE LOW TO MID 70S.
OUR NEXT COLD FRONT WILL SAG INTO THE FORECAST AREA SATURDAY NIGHT
AND SUNDAY WITH MORE CLOUDINESS AND SCATTERED SHOWERS...HOWEVER NO
SIGNIFICANT RAINFALL AMOUNTS OR DURATIONS ARE EXPECTED.
&&
.AVIATION...
MOSTLY CLEAR CONDITIONS WITH FOG CONDITIONS POSSIBLE AFTER 0900Z.
LOWER IFR VISIBILITY RANGES FOR KLAL AND KPGD AFTER 0900Z.
VISIBILITY WILL RANGE FROM 4SM TO P6SM FOR MOST OF THE TERMINALS.
&&
.MARINE...
HIGH PRESSURE WILL DRIFT OUT OF THE AREA AS A COLD FRONT MOVES
SOUTHWARD OVER THE MARINE AREA SATURDAY NIGHT THEN STALL OUT OVER
CENTRAL OR SOUTH FLORIDA ON SUNDAY. SEA FOG MAY BECOME A CONCERN
AS WELL BEGINNING FRIDAY NIGHT AND LINGERING THROUGH THE WEEKEND
ACROSS PORTIONS OF THE MARINE AREA.THE FRONTAL BOUNDARY WILL THEN
LIFT BACK NORTHWARD THROUGH THE WATERS MONDAY AS A WARM FRONT. A
COLD FRONT WILL THEN APPROACH FROM THE WEST ON MONDAY...AND MOVE
THROUGH THE MARINE AREA MONDAY NIGHT OR TUESDAY. WINDS AND SEAS
ARE EXPECTED TO REMAIN BELOW HEADLINE THRESHOLDS THROUGH SUNDAY
NIGHT. COULD SEE WINDS/SEAS REACH CAUTIONARY OR ADVISORY LEVELS
EARLY NEXT WEEK AHEAD OF AND BEHIND THE NEXT STRONG COLD FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 64 82 66 81 / 10 10 10 10
FMY 63 85 65 84 / 10 10 10 10
GIF 64 84 65 84 / 10 10 10 10
SRQ 62 80 65 79 / 10 10 10 10
BKV 57 84 60 83 / 10 10 10 10
SPG 65 81 67 79 / 10 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH MONDAY EVENING FOR
CHARLOTTE-LEE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JILLSON/HERGERT
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1216 AM EST WED FEB 20 2013
.AVIATION...
LAKE EFFECT SNOW SHOWERS WILL PERSIST THROUGH THE DAY AT SBN AND
THROUGH THE MORNING AT FWA. THE INTENSITY AND COVERAGE OF THIS
ACTIVITY WILL DIMINISH WITH TIME AS DRY/SUBSIDENT AIR CONTINUES TO
FILTER IN LOWERING INVERSION HEIGHTS. AS EXPECTED WITH LAKE EFFECT
EXPECT VARIABLE FLIGHT CONDITIONS WITH VISBY`S GENERALLY RANGING
BETWEEN IFR AND MVFR AT SBN EARLY THIS MORNING...IMPROVING TO
BETWEEN MVFR AND VFR AFTER DAYBREAK. LESSER IMPACTS AT FWA WITH
CONDITIONS RANGING BTW MVFR AND LOW END VFR. OTHERWISE...EXPECT
WIND GUSTS TO NEAR 20 KNOTS TODAY...DIMINISHING EARLY WEDNESDAY
EVENING AS LOW LEVEL RIDGING BUILDS IN.
&&
.PREV DISCUSSION... /ISSUED 833 PM EST TUE FEB 19 2013/
UPDATE...
PREVIOUS FORECAST IN GOOD SHAPE WITH JUST MINOR TWEAKS MADE TO
EVENING POPS TO ACCOUNT FOR SCATTERED SNOW SHOWERS PERSISTING
ACROSS CENTRAL SECTIONS. TAIL OF UPPER VORT MAX WHICH TRACKED
ACROSS NORTHERN INDIANA LATE THIS AFTERNOON APPEARS TO BE EXISTING
NORTHWEST OHIO AT THIS TIME. A SHEARED VORT MAX ACROSS THE
MID/UPPER MS RIVER VALLEY WILL MOVE INTO THE GREAT LAKES REGION
OVERNIGHT...WITH MUCH DRIER MID LEVEL AIR ASSOCIATED WITH THIS
FEATURE. SOME SMALLER SCALE BANDING NOTED OVER PAST FEW HOURS
ACROSS NORTHERN BERRIEN COUNTY...ALTHOUGH DEPTH OF INSTABILITY
WILL REMAIN FAIRLY SHALLOW WITH LAKE MODIFIED RAP BUFFER SOUNDINGS
SUGGESTING EQUILIBRIUM LEVELS AROUND 6K FT. INTENSITY OF LAKE
EFFECT SNOW SHOWERS SHOULD WANE TOWARD THE 04Z-06Z TIMEFRAME AS
DEEPER MOISTURE PROFILES ERODE...BUT A MORE FAVORABLE NORTHWEST
FETCH AND MAINTENANCE OF SHALLOW INSTABILITY SHOULD ALLOW FOR
CONTINUED LIGHTER LAKE EFFECT SNOW SHOWERS OVERNIGHT. WIND GUSTS
HAVE SUBSIDED EARLY THIS EVENING AS SFC LOW ACROSS SOUTHEAST
ONTARIO FILLS...AND GUSTS TO 20 TO 25 MPH SHOULD PERSIST FOR MUCH
OF THE NIGHT POSSIBLY CREATING SOME PATCHY DRIFTING SNOW CONCERNS
ACROSS SOUTHWEST LOWER MICHIGAN. WILL CONTINUE TO HIGHLIGHT THIS
POTENTIAL WITH AN SPS THROUGH AT LEAST LATE EVENING.
PREV DISCUSSION... /ISSUED 333 PM EST TUE FEB 19 2013/
SHORT TERM.../TONIGHT-WED NGT/
VORT MAX EVIDENT ON WATER VAPOR LOOP MOVG EAST ACROSS THE CWA
THIS AFTN CONTG TO CAUSE SCT SNOW SHOWERS OVER THE AREA...
ENHANCED DOWNSTREAM OF LAKE MICHIGAN IN STRONG LOW LEVEL WESTERLY
FLOW. AS THE SHRTWV MOVES EAST OF THE AREA TONIGHT SNOW SHOWER
ACTIVITY WILL TRANSITION TO PURE LAKE EFFECT. LOW LEVEL FLOW WILL
SLOWLY VEER NW OVERNIGHT STEERING LAKE EFFECT THROUGH SW MI AND
SBN-EKM AREA... WITH CHANCES DIMINISHING SEWD TO ROUTE 30 AND NW
PORTIONS OF NW OH. INVERSION BASED BLO 5KFT WITH GRADUAL MID LEVEL
DRYING SHOULD LIMIT ADDITIONAL SNOW ACCUMS TO 1-2 INCHES IN THE
FAR NW PORTION OF CWA WITH LITTLE OR NO ACCUM OVER THE REST OF THE
AREA. CONTD GRADIENT MIXING AND CLOUD COVER WILL LIMIT TEMP FALLS
OVERNIGHT BUT SW SHOULD SEE SOME CLEARING SO CONTD WITH COLDEST
MINS THERE IN THE SINGLE DIGITS RANGING TO THE LOW TEENS N-NE.
LAKE EFFECT SNOW SHOWERS WILL CONT TO SLOWLY DIMINISH WED AS
LOWERING INVERSION/DRYING CONTS. ADDITIONAL ACCUMS SHOULD BE LESS
THAN AN INCH. THERMAL TROF ALOFT WILL SHIFT EAST OF THE CWA DURING
THE DAY AND WITH SOME SUNSHINE EXPECTED BY AFTERNOON...TEMPS
SHOULD RECOVER INTO THE L-M20S.
HIGH PRESSURE RIDGE WILL BUILD INTO THE AREA WED NIGHT ALLOWING
SKIES TO CLEAR AND WINDS TO BECOME LIGHT AND VARIABLE. GIVEN GOOD
RADIATIONAL COOLING CONDITIONS STAYED CLOSE TO PREV FCST MINS IN THE
10-15 RANGE WHICH WAS GENERALLY AT OR SLIGHTLY BLO COOLEST MOS
TEMPS.
LONG TERM... /THURSDAY THROUGH TUESDAY/
ACTIVE PATTERN WILL PERSIST WITH SEVERAL STRONG WAVES SET TO MOVE
INTO THE SOUTHWESTERN STATES AND EJECT TOWARDS THE REGION. THIS
FIRST UPPER LEVEL WAVE...AND ONE OF GREATEST CONCERN...WILL MOVE
INTO WESTERN TEXAS BY EARLY THURSDAY. 120 KT JET STREAK WILL AID IN
RAPID CYCLOGENESIS WITH THESE FEATURES MOVING NE TOWARDS THE REGION
BY THURSDAY NIGHT. FURTHER STRENGTHENING OF JET STREAK (140 KTS+)
AND LFQ WILL MOVE ACROSS THE AREA HELPING TO DEVELOP A LARGE BAND OF
PRECIP. THE PRECIP SHOULD FALL IN THE FORM OF SNOW FOR MUCH OF
THURSDAY NIGHT WITH ACCUMULATIONS ANTICIPATED...HIGHER SW. NOSE OF
WARM AIR WILL SURGE NORTH LATE THURS NGT INTO FRI...MAINLY IN THE
900 TO 825 MB LAYER. SREF INCREASES TEMPS IN THIS RANGE TO 0 TO +1
C WITH NAM12 A BIT WARMER. THE TRICKY PART WILL BE AS THIS WARM AIR
ARRIVES...THE DEEPEST MSTR AND FORCING WILL BE SHIFTING EAST AND
WEAKENING AS SFC FEATURES RAPIDLY OCCLUDE. AS A RESULT...ANY
FREEZING PRECIP MAY BE IN THE FORM OF FREEZING DRIZZLE...WHICH IF
ROADS ARE SNOW COVERED...WOULD LESSEN IMPACTS. IN ADDITION...MOST
LOCATIONS WILL SEE RISING TEMPS THROUGH THE DAY WITH VALUES INTO THE
MID AND MAYBE UPPER 30S EXCEPT FOR FAR NE SECTIONS WHICH MAY LINGER
NEAR FREEZING AT BEST. HAVE ATTEMPTED TO ADD SOMEWHAT MORE DETAIL
BUT HAVE NOT GOTTEN CARRIED AWAY YET WITH EVENT STILL OVER 2 DAYS
AHEAD.
WITH THE NW AND EVENTUAL E TRACK OF THE FEATURES...NO SIG COLD AIR
WILL ARRIVE. TEMPS SHOULD ACTUALLY MODERATE FURTHER WITH AFTERNOON
HIGHS ADDING A FEW DEGREES EACH DAY INTO EARLY NEXT WEEK WHEN
READINGS WELL INTO THE 40S ARE EXPECTED. NEXT WAVE WILL DROP INTO
THE SW STATES OVER THE WEEKEND AND SIMILAR SETUP FOR CYCLOGENESIS
WILL TAKE PLACE. MODELS VARY ON EXACT TIMING AND CONTRIBUTION FROM
THE GULF BUT SYSTEM COULD END UP FAIRLY WET MONDAY NIGHT INTO
TUESDAY. SFC TEMPS AT THE ONSET MONDAY NIGHT MAY BE NEAR FREEZING
BUT STRONG LL JET SHOULD ALLOW FOR RISING TEMPS OVERNIGHT INTO
TUESDAY. HAVE WENT RAIN DURING MON EVE AND TUESDAY AFTERNOON AND FOR
NOW A RAIN/SNOW MIX OVERNIGHT MON INTO TUES MORNING. FURTHER CHANGES
WILL BE LIKELY WITH LATER FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST WEDNESDAY FOR LMZ043-
046.
SMALL CRAFT ADVISORY UNTIL 5 AM EST THURSDAY FOR LMZ043-046.
&&
$$
SHORT TERM...JT
LONG TERM...FISHER
UPDATE...MARSILI
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
934 PM CST THU FEB 21 2013
.UPDATE...
HAVE LOWERED SNOW AMOUNTS WITH THE EVENING UPDATE. DSM RAP PROFILES
SHOW PLENTY OF MOISTURE UP TO AT LEAST 17KFT...BUT WITH ONLY A VERY
NARROW LAYER OF LIFT IN THE DENDRITIC GROWTH ZONE /DGZ/ NEAR THE TOP
OF THAT MOISTURE LAYER. THIS HAS RESULTED IN MUCH OF THAT UPWARD
VERTICAL MOTION IN TEMPS WARMER THAN -12C AND NON-DENDRITIC SNOW
CRYSTALS THAT HAVE NOT ACCUMULATED MUCH...AT LEAST IN WIDESPREAD
FASHION. HIGHEST TOTALS HAVE FALLEN SOUTH AND WEST OF DSM METRO
AREA. RAP INDICATES ANOTHER FINAL SURGE OF LIFT IN THE DGZ WITH THE
NW-SE ORIENTED RADAR BAND AND COOLER CLOUD TOPS MOVING THROUGH SRN
IA RIGHT NOW. LIGHT SNOW OR FLURRIES ARE THEN EXPECTED TO LINGER
INTO FRIDAY MORNING WITH GENERAL AMOUNTS NOW 4-6 INCHES. EVEN THIS
MAY BE TOO MUCH...BUT DO NOT WANT TO GET TOO AGGRESSIVE TRIMMING
AMOUNTS. WITH BORDERLINE AMOUNTS UP TO 6 INCHES...WILL ALSO LEAVE
WARNING IN PLACE. NOTHING TO GAIN BY DOWNGRADING AT THIS POINT.
&&
.SHORT TERM /TONIGHT/...
SNOW BAND ADVECTING NORTHWARD ACROSS MUCH OF THE FORECAST AREA THIS
AFTERNOON INTO THE EVENING CAUSING RAPIDLY DETERIORATING CONDITIONS.
MODELS REMAIN IN GREAT AGREEMENT WITH TIMING AND PLACEMENT OF
HEAVIEST BAND TONIGHT AND WITH THE UPPER LOW TRACK DURING THE
OVERNIGHT HOURS. LEANED TOWARD THE TIMING OF NAM12/HRRR/HIRES
ARW-WRF FOR BAND DURING THE EVENING HOURS AND SREF/NAM OVERNIGHT.
IMPRESSIVE ISENTROPIC LIFT AHEAD OF THE UPPER LOW...GENERALLY ALONG
THE 285K TO 305K ISENTROPIC SURFACES...COMBINED WITH GOOD MOISTURE
TRANSPORT WILL CONTINUE TO PUSH THE CURRENT SNOW BAND FURTHER NORTH
LATE THIS AFTERNOON AND EVENING. THE ISENTROPIC LIFT DIMINISHES IN
STRENGTH AS THE UPPER LOW APPROACHES FROM KANSAS LATER TONIGHT INTO
THE OVERNIGHT HOURS BUT ENOUGH DEEP FORCING ASSOCIATED WITH IT AS IT
PASSES THROUGH THE STATE TO KEEP HIGH POPS GOING OVERNIGHT.
ALSO...EXPECTING THE SNOW TO CONTINUE TO FILL IN ACROSS SOUTHWEST
IOWA AND REMAIN FAIRLY PERSISTENT ACROSS THE FORECAST AREA FOR
SEVERAL HOURS TONIGHT. RAP CONFIRMS THIS AS IT HAS MAX OMEGA WITHIN
THE DENDRITIC LAYER PERSISTING THROUGH 02Z AT DSM...AND THROUGH 06Z
ACROSS NORTH CENTRAL IOWA. EVEN WITH SNOW INTENSITIES
DIMINISHING...STILL EXPECTING LIGHTER SNOWFALL ACCUMULATIONS B/T 06Z
AND 12Z FRIDAY WITH PASSAGE OF THE UPPER LOW. LEANED TOWARD A BLEND
OF THE GFS/NAM FOR QPF AMOUNTS AND STILL ON TRACK FOR GOOD SWATH OF
6 TO 9 INCHES GENERALLY SOUTH OF HIGHWAY 20. SLIGHTLY LESS FURTHER
NORTH AS THE BEST FORCING SKIRTS TO ITS SOUTHEAST.
SHARP PRESSURE GRADIENT ACROSS THE STATE KEEPS EAST TO NORTHEAST
WINDS GUSTS THROUGH 03-06Z TONIGHT BEFORE DIMINISHING. 925MB WINDS
AT 03Z STILL GUSTING AT 30KTS OVER CENTRAL PORTION OF THE FORECAST
AREA. VISIBILITY RAPIDLY DIMINISHING WITH THE ONSET OF THE SNOW AND
WILL PERSIST BEFORE THE WINDS WEAKEN LATER THIS EVENING.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
UPPER LOW WILL BE DEPARTING TO THE NORTHEAST ON FRIDAY WITH FORCING
SUBSIDING THROUGH THE DAY. HAVE CONTINUED CATEGORICAL WORDING IN
THE FAR NORTHEAST DURING THE MORNING WITH A DECENT GRADIENT TO
ESSENTIALLY NO PCPN IN FAR SOUTHWEST. SUBSIDENCE WILL CONTINUE TO
OVERSPREAD THE AREA DURING THE DAY AND HAVE CUT THE POPS OFF ACROSS
THE SOUTH BY AFTERNOON AND LEFT SCATTERED SNOW SHOWERS AND FLURRIES
IN THE NORTH UNDER THE UPPER LOW WHERE SOME WEAK LIFT WILL CONTINUE
TO RESIDE. THE THREAT OF ANY PCPN WILL END BY SATURDAY NIGHT IN THE
NORTH AS THE SYSTEM PULLS AWAY. THE 850MB THERMAL TROF IS NEARLY
ASSOCIATED WITH THE UPPER LOW SO WARM ADVECTION WILL COMMENCE
IMMEDIATELY ON FRIDAY NIGHT INTO SATURDAY ON BACKSIDE OF THE SYSTEM.
THIS WILL KEEP TEMPERATURES FROM DROPPING AS MUCH AS WOULD BE
EXPECTED WITH FRESH SNOW COVER WITH HIGHS ON SUNDAY APPROACHING OR
SLIGHTLY ABOVE FREEZING.
FOCUS WILL THEN SHIFT ON SHORTWAVE DROPPING INTO THE ROCKIES DURING
THE WEEKEND. GFS IS FARTHER NORTH AND FASTER WITH THE EVOLUTION OF
THIS SYSTEM AND APPEARS TO BE THE ODD MODEL OUT. THE EURO AND GEM
HAVE BEEN MORE CONSISTENT DIGGING THE SYSTEM THROUGH THE
INTERMOUNTAIN WEST THEN MOVING THE STORM EASTWARD THROUGH THE MID
MISSISSIPPI RIVER VALLEY. THE IMPLICATIONS OF THIS WOULD BE TO KEEP
THE BULK OF FORCING AND MOISTURE TO OUR SOUTH WITH MISSOURI SEEING
THE WORST CONDITIONS. HOWEVER...SOME WEAKER FORCING WILL BLEED INTO
THE STATE AS THE UPPER TROF IS ELONGATED FROM THE CENTRAL INTO THE
NORTHERN PLAINS. THEREFORE...SOME SNOWFALL IS STILL EXPECTED ACROSS
THE STATE FROM LATE SUNDAY NIGHT INTO TUESDAY MORNING...PRIMARILY
IMPACTING THE SOUTHERN HALF OF IOWA. SOME LIGHT TO MODERATE
ACCUMULATIONS ARE EXPECTED WITH THIS STORM AND WILL CONTINUE TO
MONITOR THE TRACK SINCE ANY NORTHWARD SHIFT WOULD BEGIN TO BRING
SIGNIFICANTLY HIGHER AMOUNTS INTO THE STATE. AFTER THIS SYSTEM
PULLS AWAY...DRIER CONDITIONS ARE EXPECTED WITH TEMPERATURES BELOW
NORMAL WITH COOL NORTHERLY FLOW BEHIND THE SYSTEM.
&&
.AVIATION...22/00Z
WIDESPREAD LIFR CONDITIONS DUE TO SNOW EXIST ALONG AND SOUTH OF
HIGHWAY 30 AND ARE EXPECTED TO ADVANCE NORTHWARD INTO KMCW/KALO
EARLY THIS EVENING. CONDITIONS ARE EXPECTED TO IMPROVE JUST SLIGHTLY
OVERNIGHT WITH SNOWFALL RATES DECREASING BUT CONDITIONS WILL STILL
REMAIN IFR-LIFR DUE TO SNOW VSBYS AND CIGS INTO AT LEAST FRI
MORNING. MVFR CIGS AND FLURRIES ARE ALSO EXPECTED TO PERSIST
THROUGH MUCH OF FRI AS WELL.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST FRIDAY FOR
ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-
CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-MADISON-
MAHASKA-MARION-MONROE-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE-BLACK HAWK-BREMER-BUTLER-CERRO GORDO-EMMET-
FRANKLIN-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MARSHALL-
PALO ALTO-POCAHONTAS-TAMA-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...KLP
LONG TERM...COGIL
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
559 PM CST THU FEB 21 2013
.SHORT TERM /TONIGHT/...
SNOW BAND ADVECTING NORTHWARD ACROSS MUCH OF THE FORECAST AREA THIS
AFTERNOON INTO THE EVENING CAUSING RAPIDLY DETERIORATING CONDITIONS.
MODELS REMAIN IN GREAT AGREEMENT WITH TIMING AND PLACEMENT OF
HEAVIEST BAND TONIGHT AND WITH THE UPPER LOW TRACK DURING THE
OVERNIGHT HOURS. LEANED TOWARD THE TIMING OF NAM12/HRRR/HIRES
ARW-WRF FOR BAND DURING THE EVENING HOURS AND SREF/NAM OVERNIGHT.
IMPRESSIVE ISENTROPIC LIFT AHEAD OF THE UPPER LOW...GENERALLY ALONG
THE 285K TO 305K ISENTROPIC SURFACES...COMBINED WITH GOOD MOISTURE
TRANSPORT WILL CONTINUE TO PUSH THE CURRENT SNOW BAND FURTHER NORTH
LATE THIS AFTERNOON AND EVENING. THE ISENTROPIC LIFT DIMINISHES IN
STRENGTH AS THE UPPER LOW APPROACHES FROM KANSAS LATER TONIGHT INTO
THE OVERNIGHT HOURS BUT ENOUGH DEEP FORCING ASSOCIATED WITH IT AS IT
PASSES THROUGH THE STATE TO KEEP HIGH POPS GOING OVERNIGHT.
ALSO...EXPECTING THE SNOW TO CONTINUE TO FILL IN ACROSS SOUTHWEST
IOWA AND REMAIN FAIRLY PERSISTENT ACROSS THE FORECAST AREA FOR
SEVERAL HOURS TONIGHT. RAP CONFIRMS THIS AS IT HAS MAX OMEGA WITHIN
THE DENDRITIC LAYER PERSISTING THROUGH 02Z AT DSM...AND THROUGH 06Z
ACROSS NORTH CENTRAL IOWA. EVEN WITH SNOW INTENSITIES
DIMINISHING...STILL EXPECTING LIGHTER SNOWFALL ACCUMULATIONS B/T 06Z
AND 12Z FRIDAY WITH PASSAGE OF THE UPPER LOW. LEANED TOWARD A BLEND
OF THE GFS/NAM FOR QPF AMOUNTS AND STILL ON TRACK FOR GOOD SWATH OF
6 TO 9 INCHES GENERALLY SOUTH OF HIGHWAY 20. SLIGHTLY LESS FURTHER
NORTH AS THE BEST FORCING SKIRTS TO ITS SOUTHEAST.
SHARP PRESSURE GRADIENT ACROSS THE STATE KEEPS EAST TO NORTHEAST
WINDS GUSTS THROUGH 03-06Z TONIGHT BEFORE DIMINISHING. 925MB WINDS
AT 03Z STILL GUSTING AT 30KTS OVER CENTRAL PORTION OF THE FORECAST
AREA. VISIBILITY RAPIDLY DIMINISHING WITH THE ONSET OF THE SNOW AND
WILL PERSIST BEFORE THE WINDS WEAKEN LATER THIS EVENING.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
UPPER LOW WILL BE DEPARTING TO THE NORTHEAST ON FRIDAY WITH FORCING
SUBSIDING THROUGH THE DAY. HAVE CONTINUED CATEGORICAL WORDING IN
THE FAR NORTHEAST DURING THE MORNING WITH A DECENT GRADIENT TO
ESSENTIALLY NO PCPN IN FAR SOUTHWEST. SUBSIDENCE WILL CONTINUE TO
OVERSPREAD THE AREA DURING THE DAY AND HAVE CUT THE POPS OFF ACROSS
THE SOUTH BY AFTERNOON AND LEFT SCATTERED SNOW SHOWERS AND FLURRIES
IN THE NORTH UNDER THE UPPER LOW WHERE SOME WEAK LIFT WILL CONTINUE
TO RESIDE. THE THREAT OF ANY PCPN WILL END BY SATURDAY NIGHT IN THE
NORTH AS THE SYSTEM PULLS AWAY. THE 850MB THERMAL TROF IS NEARLY
ASSOCIATED WITH THE UPPER LOW SO WARM ADVECTION WILL COMMENCE
IMMEDIATELY ON FRIDAY NIGHT INTO SATURDAY ON BACKSIDE OF THE SYSTEM.
THIS WILL KEEP TEMPERATURES FROM DROPPING AS MUCH AS WOULD BE
EXPECTED WITH FRESH SNOW COVER WITH HIGHS ON SUNDAY APPROACHING OR
SLIGHTLY ABOVE FREEZING.
FOCUS WILL THEN SHIFT ON SHORTWAVE DROPPING INTO THE ROCKIES DURING
THE WEEKEND. GFS IS FARTHER NORTH AND FASTER WITH THE EVOLUTION OF
THIS SYSTEM AND APPEARS TO BE THE ODD MODEL OUT. THE EURO AND GEM
HAVE BEEN MORE CONSISTENT DIGGING THE SYSTEM THROUGH THE
INTERMOUNTAIN WEST THEN MOVING THE STORM EASTWARD THROUGH THE MID
MISSISSIPPI RIVER VALLEY. THE IMPLICATIONS OF THIS WOULD BE TO KEEP
THE BULK OF FORCING AND MOISTURE TO OUR SOUTH WITH MISSOURI SEEING
THE WORST CONDITIONS. HOWEVER...SOME WEAKER FORCING WILL BLEED INTO
THE STATE AS THE UPPER TROF IS ELONGATED FROM THE CENTRAL INTO THE
NORTHERN PLAINS. THEREFORE...SOME SNOWFALL IS STILL EXPECTED ACROSS
THE STATE FROM LATE SUNDAY NIGHT INTO TUESDAY MORNING...PRIMARILY
IMPACTING THE SOUTHERN HALF OF IOWA. SOME LIGHT TO MODERATE
ACCUMULATIONS ARE EXPECTED WITH THIS STORM AND WILL CONTINUE TO
MONITOR THE TRACK SINCE ANY NORTHWARD SHIFT WOULD BEGIN TO BRING
SIGNIFICANTLY HIGHER AMOUNTS INTO THE STATE. AFTER THIS SYSTEM
PULLS AWAY...DRIER CONDITIONS ARE EXPECTED WITH TEMPERATURES BELOW
NORMAL WITH COOL NORTHERLY FLOW BEHIND THE SYSTEM.
&&
.AVIATION...22/00Z
WIDESPREAD LIFR CONDITIONS DUE TO SNOW EXIST ALONG AND SOUTH OF
HIGHWAY 30 AND ARE EXPECTED TO ADVANCE NORTHWARD INTO KMCW/KALO
EARLY THIS EVENING. CONDITIONS ARE EXPECTED TO IMPROVE JUST SLIGHTLY
OVERNIGHT WITH SNOWFALL RATES DECREASING BUT CONDITIONS WILL STILL
REMAIN IFR-LIFR DUE TO SNOW VSBYS AND CIGS INTO AT LEAST FRI
MORNING. MVFR CIGS AND FLURRIES ARE ALSO EXPECTED TO PERSIST
THROUGH MUCH OF FRI AS WELL.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST FRIDAY FOR
ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-
CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-MADISON-
MAHASKA-MARION-MONROE-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE-BLACK HAWK-BREMER-BUTLER-CERRO GORDO-EMMET-
FRANKLIN-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MARSHALL-
PALO ALTO-POCAHONTAS-TAMA-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...KLP
LONG TERM...COGIL
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
526 PM CST THU FEB 21 2013
...UPDATE TO AVIATION...
.DISCUSSION...
TONIGHT THROUGH FRIDAY...
THE UPPER LEVEL LOW WAS LOCATED ACROSS THE NORTHEAST TEXAS PANHANDLE
THIS AFTERNOON. ONE 1.5PV ANOMALY WAS LIFTING NORTHWARD ACROSS WEST
CENTRAL KS...WITH A SECOND 1.5PV ANOMALY OVER WESTERN OK. THE
SHORT-TERM MODELS...HRRR AND RAP SHOW THE 1.5PV ANOMALY
LIFTING NORTHEAST ACROSS EASTERN KS. AHEAD OF THE 1.5PV ANOMALY THE
FRONTOGENETICAL FORCING SHOULD INCREASE TO PROVIDE A PERIOD OF LIGHT
SNOW. THE MODELS SHOW AN INCREASE IN THE NEGATIVE SATURATED
EPV...CSI...WHICH COULD CAUSE SOME SLIGHTLY HEAVIER SNOW
BANDS...THUS THE WESTERN AND CENTRAL COUNTIES OF THE CWA COULD SEE
SOME LOCALLY HIGHER SNOW AMOUNTS.
UNTIL THE DENDRITIC GROWTH ZONE SATURATES LATER THIS AFTERNOON
THERE MAY BE PERIODS OF FREEZING DRIZZLE ACROSS THE EASTERN HALF OF
THE CWA. THE PATCHY FREEZING DRIZZLE MAY REFORM LATER THIS EVENING
ONCE THE STRONGER ASCENT SHIFTS NORTHEAST OF THE CWA. ISENTROPIC
DOWNGLIDE SHOULD BRING AN END THE THE FREEZING DRIZZLE CHANCE AFTER
MIDNIGHT.
THE STORM TOTAL SNOWFALL WILL RANGE FROM 6 TO 15 INCHES WITH SOME
LOCALLY HIGHER AMOUNTS.
I WILL KEEP THE WINTER STORM WARNING IN EFFECT UNTIL 00Z FOR THE
WESTERN HALF OF THE CWA AND UNTIL MIDNIGHT FOR THE EASTERN HALF OF
THE CWA.
FRIDAY...THE SKIES SHOULD BEGIN TO CLEAR FROM WEST TO EAST ACROSS
THE CWA THROUGH THE MID AND LATE MORNING HOURS. HIGHS WILL CONTINUE
TO BE COLD WITH MID 20S...GIVEN SEVERAL INCHES OF SNOW COVER.
GARGAN
FRIDAY NIGHT THROUGH THURSDAY...
DRY CONDITIONS ARE EXPECTED FOR THE START OF THE WEEKEND AS THE
UPPER LEVEL TROUGH THAT IMPACTED THE REGION WITH WINTER WEATHER
TODAY SLIDES NORTH TOWARD THE GREAT LAKES REGION. SURFACE HIGH
PRESSURE BRIEFLY WILL SETTLE INTO THE REGION BEHIND THE EXITING
STORM SYSTEM BEFORE THE NEXT UPPER LEVEL TROUGH BEGINS TO DIG
SOUTHWARD ACROSS THE NORTHERN AND CENTRAL PLAINS DURING THE LATTER
PART OF THE WEEKEND. THERE IS STILL UNCERTAINTY AMONGST THE MODELS
REGARDING JUST HOW FAR SOUTH THIS TROUGH WILL DIG ALONG AND EAST OF
THE ROCKY MOUNTAINS AND HOW QUICKLY THE UPPER LOW EJECTS
NORTHEASTWARD ACROSS THE FORECAST AREA AND FURTHER EAST OF THE AREA.
THESE MODEL DISCREPANCIES LEAD TO DIFFICULTIES IN PINNING DOWN THE
TIMING OF ANY PRECIPITATION FROM THIS SYSTEM. MODELS SEEM TO BE A
BIT SLOWER IN BRINGING THE SYSTEM INTO THE AREA...SO HAVE DECREASED
POPS FOR SUNDAY WITH CHANCE POPS FOR THE SUNDAY NIGHT THROUGH MONDAY
NIGHT TIMEFRAME. THESE POPS BEST REFLECT A BLEND OF THE ECMWF/GEM.
THE GFS CURRENTLY IS AN OUTLIER IN KEEPING THE UPPER TROUGH FURTHER
NORTH AND ONLY HAVING PRECIPITATION SKIMMING ACROSS THE NORTHERN
PORTION OF THE FORECAST AREA. DEPENDING UPON THE TIMING OF
PRECIPITATION...THE REGION COULD SEE A COMBINATION OF RAIN AND SNOW
SHOWERS WITH THIS SYSTEM. AT THIS TIME...THE SYSTEM LOOKS TO EXIT
EAST OF THE AREA BY TUESDAY. A WEAK RIDGE WILL MOVE INTO THE REGION
BEHIND THIS TROUGH WITH DRY CONDITIONS EXPECTED FOR MID-WEEK. BY THE
END OF THE PERIOD MODEL DISCREPANCIES EXIST WITH REGARDS TO THE NEXT
SHORTWAVE THAT EJECTS INTO THE CENTRAL PLAINS. KEPT ANY MENTION OF
PRECIPITATION OUT OF THE FORECAST AT THIS TIME.
TEMPERATURE FORECASTS FOR THE PERIOD HAVE BEEN COMPLICATED BY THE
SEVERAL INCHES OF SNOW RECEIVED ACROSS THE FORECAST AREA FROM
TODAY`S STORM. WITH THIS IN MIND...HAVE TRENDED WITH TEMPERATURES
STAYING BELOW THE SEASONAL NORMALS THROUGH THE EXTENDED FORECAST
PERIOD...WITH HIGHS GENERALLY IN THE 30S. THE COLDEST NIGHT LOOKS TO
BE FRIDAY NIGHT/EARLY SATURDAY MORNING AS LOW TEMPERATURES PLUMMET
INTO THE SINGLE DIGITS...WITH WIND CHILL VALUES ANYWHERE FROM ZERO
TO 8 BELOW ZERO. OTHERWISE...LOWS GENERALLY LOOK TO BE IN THE TEENS
AND 20S. TEMPERATURE FORECASTS WILL NEED TO BE ADJUSTED DEPENDING
UPON ANY MELTING OF SNOW THAT OCCURS IN THE UPCOMING DAYS.
ACH
&&
.AVIATION...
LIGHT SNOW EXPECTED TO PERSIST FOR ANOTHER COUPLE HOURS...WITH
BRIEF PERIODS OF MODERATE TO POSSIBLY HEAVY SNOW AS THE FINAL FEW
SNOW BANDS MOVE THROUGH THE TERMINALS. THE ATMOSPHERIC COLUMN WILL
GRADUALLY DRY OUT FROM TOP TO BOTTOM CAUSING A PERIOD OF SNOW
MIXED WITH FREEZING DRIZZLE BEFORE THINGS COMPLETELY DRY OUT
AROUND MIDNIGHT. WILL AMEND SHOULD CONDITIONS IMPROVE QUICKER THAN
ANTICIPATED.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR KSZ010>012-
022>024-026-036>040-054>056-058-059.
WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ008-009-
020-021-034-035.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1033 AM MST WED FEB 20 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 404 AM MST WED FEB 20 2013
MAJOR WINTER STORM WILL BE THE FORECAST CONCERN. SATELLITE SHOWING A
PROGRESSIVE FLOW OVER MOST OF THE PACIFIC WHICH TRANSITIONS TO A
MUCH MORE AMPLIFIED FLOW OVER NORTH AMERICA. SYSTEM THAT WILL BE
INFLUENCING OUR WEATHER THROUGH THURSDAY IS DIGGING ACROSS
CALIFORNIA AT THIS TIME.
AT JET LEVEL...MODELS APPEAR TO BE INITIALIZING FINE WITH THE MAIN
JET SEGMENT STILL OVER WATER. MODELS DID FINE AT MID LEVELS THROUGH
06Z ALTHOUGH INITIALLY THE MODELS TENDED TO HAVE THE CALIFORNIA
SYSTEM A LITTLE TOO FAR SOUTH. SREF AND NAM WERE DOING THE BEST ON
THE SURFACE PRESSURE/WIND FIELD WITH THE CANADIAN BETTER...NOT
PERFECT...WITH THE DEWPOINTS. THE RUC AND HRRR WERE DOING WELL IN
CATCHING THE DEVELOPING PRECIPITATION AND WERE ECHOING/CONFIRMING
THE LARGER SCALE MODELS. THIS SYSTEM IS STILL NOT OVER LAND YET SO AM
STILL NERVOUS ABOUT WHAT THIS SYSTEM WILL DO DESPITE THE GOOD MODEL
AGREEMENT. THE MEMORY OF LAST YEARS LESS THAN EXPECTED FEBRUARY STORM
IS STILL FRESH IN MY MEMORY.
TODAY/TONIGHT...MAJOR WINTER STORM AND WINTER STORM WARNING ON TRACK.
INITIALLY THE ONE THING THAT BOTHERED WAS THE DRY SLOT/PUNCH COMING
IN FROM THE SOUTHWEST PER SATELLITE AND UPPER AIR ANALYSIS. ON THE
POSITIVE SIDE OF THAT...THE LAST FEW HOURS THE SATELLITE IS SHOWING
CLOUDS INCREASING AND COOLING TO OUR SOUTH AND WEST. THERE HAS BEEN
PERIODIC LIGHTNING STRIKES TO OUR SOUTHWEST AS WELL. OVER WESTERN NEW
MEXICO. THERE IS ALSO SPORADIC LIGHTNING STRIKES OVER EASTERN ARIZONA
AND WESTERN NEW MEXICO.
IN GENERAL...A LONG TERM...MODERATE TO SOMETIMES HEAVY...SNOW EVENT
LOOKS TO BE UNFOLDING AT THIS TIME. WHAT IS EXTREMELY SCARY AND
ENCOURAGE IS THE MODEL AGREEMENT IN QPF/SNOW AMOUNT PLACEMENT BY
THE LARGE SCALE DETERMINISTIC MODELS AND AS STATED ABOVE BEING
SUPPORTED THE SMALL SCALE MODEL OUTPUT. MODEL OUTPUT FOR TODAY CAME
IN A LITTLE COLDER AND ONLY SUPPORTED A BRIEF AND LIGHT ACCUMULATION
OF ICE WITH A CHANGE OVER TO SNOW EXPECTED BY THE MIDDLE OF THE DAY.
FIRST SHORTWAVE TROUGH WITH FAVORABLE THETA-E LAPSE RATES MOVE
THROUGH INTO THE MIDDLE OF THE DAY/EARLY THIS AFTERNOON. SO FORCING
AND INSTABILITY HAVE INCREASED. SO INCREASED SNOWFALL AMOUNTS
SIGNIFICANTLY FOR TODAY. IF MESOSCALE MODELS ARE CORRECT I MAY NOT
HAVE SNOWFALL AMOUNTS HIGH ENOUGH IN THE SOUTHEAST.
DAY SHIFT MENTIONED THE POSSIBILITY OF A BRIEF LULL. THIS LULL MAY
BE VERY BRIEF AND MAY NOT EVEN BE WORTH DEPICTING SINCE MOST BUT NOT
ALL MODEL OUTPUT IS SHOWING LEFT FRONT QUADRANT AFFECTING AT LEAST
THE SOUTHEAST HALF OF THE AREA FROM LATE AFTERNOON UNTIL NEAR/SHORTLY
AFTER 06Z. BY 12Z...MAIN JET IS EAST OF THE AREA WITH SUBSIDENT AREA
OF JET OVER THE AREA. HOWEVER...BY LATE LATER TONIGHT THE 700 MB LOW
MOVES INTO A VERY FAVORABLE POSITION FOR A MODERATE TO HEAVY SNOW
BAND TO DEVELOP AND THAT IS CONFIRMED BY FORCING/INSTABILITY
FORECASTS. CONSEQUENTLY POPS HAVE BEEN INCREASED TO 100 PERCENT
BEGINNING AT 18Z AND CONTINUING THROUGH THE NIGHT. FORCING...QPF
AND PROBABILITY OUTPUT SUPPORTS AND AS A RESULT AMOUNTS GOT
INCREASED. BLOWING SNOW WILL ALSO START AROUND MIDDAY AND WILL
CONTINUE THROUGH THE END OF THIS PERIOD. HIGH TEMPERATURES WILL RISE
LITTLE TODAY.
THURSDAY/THURSDAY NIGHT...MODELS ARE SLOWER AND IN GOOD AGREEMENT
WITH THE MID LEVEL LOW PLACEMENT. IN FACT IN SOME PLACES...THE
MODERATE TO HEAVY SNOW MAY NOT BEGIN UNTIL EARLY THIS PERIOD. HAD
TO KEEP KEEP IN MUCH HIGHER POPS THROUGH MOST OF THE DAY...
ESPECIALLY IN THE EAST WITH BLOWING CONTINUING TO BE A PROBLEM. THERE
WILL BE SOME LINGERING LIGHT SNOW IN THE EAST IN THE EVENING. VERY
COLD MAXES WILL BE IN PLACE WITH DROPPING WIND CHILL TEMPERATURES
THROUGH THE DAY AND MUCH BELOW ZERO DURING THE NIGHT. MAY GET CLOSE
TO WIND CHILL ADVISORY CRITERIA THURSDAY NIGHT. MODELS SAYING WINDS
WILL STAY UP ENOUGH DURING THE NIGHT BUT DO NOT BUY THAT. WENT
BELOW LOW TEMPERATURE GUIDANCE BUT THE EXPECTED SNOW FIELD I DOUBT
THEY WILL BE LOW ENOUGH.
FRIDAY...WILL BE DRY FOR THE DAY. LOWERED MAXES...ESPECIALLY IN THE
EAST. HOWEVER...DO EXPECT THIS MAXES WILL BE TOO WARM BUT AT LEAST
STARTED TO TREND COLDER.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 308 AM MST WED FEB 20 2013
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS THE TRI-STATE AREA
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK AS THE OVERALL ATMOSPHERIC
PATTERN IS FAVORABLE FOR A SERIES OF DISTURBANCES TO MOVE THROUGH.
ON FRIDAY NIGHT...A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS
EASTERN COLORADO AND WESTERN KANSAS. AT THE PRESENT TIME...MODELS
ARE SUGGESTING THAT THERE IS A CHANCE SOME PRECIPITATION COULD SNEAK
INTO FAR SOUTHERN PORTIONS OF THE FORECAST AREA SO HAVE INCLUDED
SLIGHT CHANCE POPS. PRECIPITATION SHOULD BE FAIRLY LIGHT SO NO MAJOR
ADDITIONAL ACCUMULATIONS ARE EXPECTED WITH THIS WEAK SHORTWAVE.
CONTINUED COLD TEMPERATURES ARE EXPECTED...AND HAVE LOWERED
TEMPERATURES FROM GUIDANCE ACCORDINGLY DUE TO EXPECTED SNOW COVER
AND MODELS NOT QUITE PICKING UP ON THIS SNOW COVER YET.
ATTENTION THEN TURNS TO ANOTHER POTENTIALLY BIG WINTER STORM FOR
SUNDAY THROUGH MONDAY NIGHT. A STRONG LONGWAVE TROUGH WILL DIVE
SOUTH ACROSS THE PACIFIC NORTHWEST ON FRIDAY...ACROSS THE ROCKY
MOUNTAINS ON SATURDAY AND INTO THE CENTRAL PLAINS BY SUNDAY. MODELS
ARE SUGGESTING THAT AS THIS LONGWAVE TROUGH EJECTS OVER THE
PLAINS...STRONG CYCLOGENESIS SHOULD OCCUR IN THE LEE OF THE ROCKIES.
THERE ARE STILL SOME DIFFERENCES WITH RESPECT TO LOCATION OF THE
SURFACE LOW AND 500 MB TROUGH BETWEEN THE GFS...EURO AND CANADIAN.
AT THIS TIME...BELIEVE THAT THE GFS RUN IS A LITTLE QUICK AND A
LITTLE TOO FAR NORTH. THE CANADIAN AND EUROPEAN MODELS ARE IN
SOMEWHAT FAIR AGREEMENT BUT THERE ARE A FEW DIFFERENCES BETWEEN
THESE TWO AS WELL. COMPARING THIS TO THE STORM SYSTEM CURRENTLY
COMING IN...SNOW ACCUMULATIONS DO NOT LOOK LIKE THEY WILL BE NEARLY
AS HIGH FOR THE SECOND STORM. HOWEVER...WINDS ON THE BACK SIDE OF
THE SURFACE LOW LOOK TO BE MUCH STRONGER FOR SUNDAY AND MONDAY THAN
AT ANY POINT DURING THIS CURRENT STORM. TOOK A BLEND OF THE
GFS...CANADIAN AND EUROPEAN MODELS FOR WIND SPEED FORECASTS. THE
CANADIAN MODEL IS THE LOWEST WITH WIND SPEEDS WHILE THE EUROPEAN IS
MUCH HIGHER THAN BOTH THE CANADIAN AND THE GFS MODELS. THE EUROPEAN
MODEL IS SUGGESTING SUSTAINED SURFACE WIND SPEEDS OF 40 KTS ON THE
BACKSIDE OF THIS SYSTEM. AS A RESULT...INCREASED WINDS OVER THE CR
INIT PROCEDURE BY BLENDING THE MODELS AND THROUGH LOCAL
COLLABORATION. BY THE TIME THIS SYSTEM MOVES IN...THERE SHOULD BE
SOMEWHAT OF A CRUST OVER THE SNOW PACK FROM THE PREVIOUS SYSTEM. AS
A RESULT...ANY NEW SNOWFALL WILL LIKELY BLOW AROUND IN THE STRONG
WINDS SO HAVE MENTIONED PATCHY BLOWING SNOW FOR NOW. AGAIN...THIS
COULD BE ANOTHER WINTER STORM FOR THE REGION SO CONTINUE TO MONITOR
FORECAST UPDATES AS THE ACTIVE PATTERN CONTINUES.
TEMPERATURES SHOULD COOL A LITTLE MORE FOLLOWING THE NEXT STORM
SYSTEM AS STRONG NORTHWEST WINDS SHOULD PULL DOWN SOME COLD CANADIAN
AIR. WITH LOTS OF SNOW ON THE GROUND FROM THIS PREVIOUS
SNOW...SHOULD HAVE NO PROBLEM BRINGING IN THE COLD AIR. ANOTHER
DISTURBANCE WILL MOVE ACROSS THE REGION ON TUESDAY NIGHT AND INTO
WEDNESDAY. ONLY LIGHT SNOW HAS BEEN MENTIONED AS THIS SYSTEM IS TOO
FAR OUT TO GET A GOOD READ ON IT.
THANKS TO ALL FOR COLLABORATION THROUGH THE WHOLE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1032 AM MST WED FEB 20 2013
IFR TO LIFR CONDITIONS WILL PERSIST OVER THE NEXT 24 HOURS AT BOTH
GLD AND MCK. A STRONG WINTER STORM IS AFFECTING THE ENTIRE CENTRAL
PLAINS WITH A SIGNIFICANT AMOUNT OF SNOWFALL AND BREEZY WINDS.
BLOWING SNOW WILL BE THE MAIN VISIBILITY OBSCURATION THROUGH THE TAF
PERIOD. MODERATE SNOWFALL WITH BLOWING SNOW WILL OCCUR THIS
AFTERNOON AT BOTH SITES. THE WORST OF THE STORM WILL BE LATE TONIGHT
INTO MID-DAY TOMORROW WITH PERIODS OF HEAVY SNOWFALL. CONDITIONS
WILL REMAIN IFR/LIFR UNTIL LATE TOMORROW NIGHT WHEN THE SYSTEM EXITS
THE REGION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER STORM WARNING UNTIL 5 PM MST /6 PM CST/ THURSDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER STORM WARNING UNTIL 5 PM MST THURSDAY FOR COZ090>092.
NE...WINTER STORM WARNING UNTIL 5 PM MST /6 PM CST/ THURSDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
445 AM MST WED FEB 20 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 404 AM MST WED FEB 20 2013
MAJOR WINTER STORM WILL BE THE FORECAST CONCERN. SATELLITE SHOWING A
PROGRESSIVE FLOW OVER MOST OF THE PACIFIC WHICH TRANSITIONS TO A
MUCH MORE AMPLIFIED FLOW OVER NORTH AMERICA. SYSTEM THAT WILL BE
INFLUENCING OUR WEATHER THROUGH THURSDAY IS DIGGING ACROSS
CALIFORNIA AT THIS TIME.
AT JET LEVEL...MODELS APPEAR TO BE INITIALIZING FINE WITH THE MAIN
JET SEGMENT STILL OVER WATER. MODELS DID FINE AT MID LEVELS THROUGH
06Z ALTHOUGH INITIALLY THE MODELS TENDED TO HAVE THE CALIFORNIA
SYSTEM A LITTLE TOO FAR SOUTH. SREF AND NAM WERE DOING THE BEST ON
THE SURFACE PRESSURE/WIND FIELD WITH THE CANADIAN BETTER...NOT
PERFECT...WITH THE DEWPOINTS. THE RUC AND HRRR WERE DOING WELL IN
CATCHING THE DEVELOPING PRECIPITATION AND WERE ECHOING/CONFIRMING
THE LARGER SCALE MODELS. THIS SYSTEM IS STILL NOT OVER LAND YET SO AM
STILL NERVOUS ABOUT WHAT THIS SYSTEM WILL DO DESPITE THE GOOD MODEL
AGREEMENT. THE MEMORY OF LAST YEARS LESS THAN EXPECTED FEBRUARY STORM
IS STILL FRESH IN MY MEMORY.
TODAY/TONIGHT...MAJOR WINTER STORM AND WINTER STORM WARNING ON TRACK.
INITIALLY THE ONE THING THAT BOTHERED WAS THE DRY SLOT/PUNCH COMING
IN FROM THE SOUTHWEST PER SATELLITE AND UPPER AIR ANALYSIS. ON THE
POSITIVE SIDE OF THAT...THE LAST FEW HOURS THE SATELLITE IS SHOWING
CLOUDS INCREASING AND COOLING TO OUR SOUTH AND WEST. THERE HAS BEEN
PERIODIC LIGHTNING STRIKES TO OUR SOUTHWEST AS WELL. OVER WESTERN NEW
MEXICO. THERE IS ALSO SPORADIC LIGHTNING STRIKES OVER EASTERN ARIZONA
AND WESTERN NEW MEXICO.
IN GENERAL...A LONG TERM...MODERATE TO SOMETIMES HEAVY...SNOW EVENT
LOOKS TO BE UNFOLDING AT THIS TIME. WHAT IS EXTREMELY SCARY AND
ENCOURAGE IS THE MODEL AGREEMENT IN QPF/SNOW AMOUNT PLACEMENT BY
THE LARGE SCALE DETERMINISTIC MODELS AND AS STATED ABOVE BEING
SUPPORTED THE SMALL SCALE MODEL OUTPUT. MODEL OUTPUT FOR TODAY CAME
IN A LITTLE COLDER AND ONLY SUPPORTED A BRIEF AND LIGHT ACCUMULATION
OF ICE WITH A CHANGE OVER TO SNOW EXPECTED BY THE MIDDLE OF THE DAY.
FIRST SHORTWAVE TROUGH WITH FAVORABLE THETA-E LAPSE RATES MOVE
THROUGH INTO THE MIDDLE OF THE DAY/EARLY THIS AFTERNOON. SO FORCING
AND INSTABILITY HAVE INCREASED. SO INCREASED SNOWFALL AMOUNTS
SIGNIFICANTLY FOR TODAY. IF MESOSCALE MODELS ARE CORRECT I MAY NOT
HAVE SNOWFALL AMOUNTS HIGH ENOUGH IN THE SOUTHEAST.
DAY SHIFT MENTIONED THE POSSIBILITY OF A BRIEF LULL. THIS LULL MAY
BE VERY BRIEF AND MAY NOT EVEN BE WORTH DEPICTING SINCE MOST BUT NOT
ALL MODEL OUTPUT IS SHOWING LEFT FRONT QUADRANT AFFECTING AT LEAST
THE SOUTHEAST HALF OF THE AREA FROM LATE AFTERNOON UNTIL NEAR/SHORTLY
AFTER 06Z. BY 12Z...MAIN JET IS EAST OF THE AREA WITH SUBSIDENT AREA
OF JET OVER THE AREA. HOWEVER...BY LATE LATER TONIGHT THE 700 MB LOW
MOVES INTO A VERY FAVORABLE POSITION FOR A MODERATE TO HEAVY SNOW
BAND TO DEVELOP AND THAT IS CONFIRMED BY FORCING/INSTABILITY
FORECASTS. CONSEQUENTLY POPS HAVE BEEN INCREASED TO 100 PERCENT
BEGINNING AT 18Z AND CONTINUING THROUGH THE NIGHT. FORCING...QPF
AND PROBABILITY OUTPUT SUPPORTS AND AS A RESULT AMOUNTS GOT
INCREASED. BLOWING SNOW WILL ALSO START AROUND MIDDAY AND WILL
CONTINUE THROUGH THE END OF THIS PERIOD. HIGH TEMPERATURES WILL RISE
LITTLE TODAY.
THURSDAY/THURSDAY NIGHT...MODELS ARE SLOWER AND IN GOOD AGREEMENT
WITH THE MID LEVEL LOW PLACEMENT. IN FACT IN SOME PLACES...THE
MODERATE TO HEAVY SNOW MAY NOT BEGIN UNTIL EARLY THIS PERIOD. HAD
TO KEEP KEEP IN MUCH HIGHER POPS THROUGH MOST OF THE DAY...
ESPECIALLY IN THE EAST WITH BLOWING CONTINUING TO BE A PROBLEM. THERE
WILL BE SOME LINGERING LIGHT SNOW IN THE EAST IN THE EVENING. VERY
COLD MAXES WILL BE IN PLACE WITH DROPPING WIND CHILL TEMPERATURES
THROUGH THE DAY AND MUCH BELOW ZERO DURING THE NIGHT. MAY GET CLOSE
TO WIND CHILL ADVISORY CRITERIA THURSDAY NIGHT. MODELS SAYING WINDS
WILL STAY UP ENOUGH DURING THE NIGHT BUT DO NOT BUY THAT. WENT
BELOW LOW TEMPERATURE GUIDANCE BUT THE EXPECTED SNOW FIELD I DOUBT
THEY WILL BE LOW ENOUGH.
FRIDAY...WILL BE DRY FOR THE DAY. LOWERED MAXES...ESPECIALLY IN THE
EAST. HOWEVER...DO EXPECT THIS MAXES WILL BE TOO WARM BUT AT LEAST
STARTED TO TREND COLDER.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 308 AM MST WED FEB 20 2013
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS THE TRI-STATE AREA
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK AS THE OVERALL ATMOSPHERIC
PATTERN IS FAVORABLE FOR A SERIES OF DISTURBANCES TO MOVE THROUGH.
ON FRIDAY NIGHT...A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS
EASTERN COLORADO AND WESTERN KANSAS. AT THE PRESENT TIME...MODELS
ARE SUGGESTING THAT THERE IS A CHANCE SOME PRECIPITATION COULD SNEAK
INTO FAR SOUTHERN PORTIONS OF THE FORECAST AREA SO HAVE INCLUDED
SLIGHT CHANCE POPS. PRECIPITATION SHOULD BE FAIRLY LIGHT SO NO MAJOR
ADDITIONAL ACCUMULATIONS ARE EXPECTED WITH THIS WEAK SHORTWAVE.
CONTINUED COLD TEMPERATURES ARE EXPECTED...AND HAVE LOWERED
TEMPERATURES FROM GUIDANCE ACCORDINGLY DUE TO EXPECTED SNOW COVER
AND MODELS NOT QUITE PICKING UP ON THIS SNOW COVER YET.
ATTENTION THEN TURNS TO ANOTHER POTENTIALLY BIG WINTER STORM FOR
SUNDAY THROUGH MONDAY NIGHT. A STRONG LONGWAVE TROUGH WILL DIVE
SOUTH ACROSS THE PACIFIC NORTHWEST ON FRIDAY...ACROSS THE ROCKY
MOUNTAINS ON SATURDAY AND INTO THE CENTRAL PLAINS BY SUNDAY. MODELS
ARE SUGGESTING THAT AS THIS LONGWAVE TROUGH EJECTS OVER THE
PLAINS...STRONG CYCLOGENESIS SHOULD OCCUR IN THE LEE OF THE ROCKIES.
THERE ARE STILL SOME DIFFERENCES WITH RESPECT TO LOCATION OF THE
SURFACE LOW AND 500 MB TROUGH BETWEEN THE GFS...EURO AND CANADIAN.
AT THIS TIME...BELIEVE THAT THE GFS RUN IS A LITTLE QUICK AND A
LITTLE TOO FAR NORTH. THE CANADIAN AND EUROPEAN MODELS ARE IN
SOMEWHAT FAIR AGREEMENT BUT THERE ARE A FEW DIFFERENCES BETWEEN
THESE TWO AS WELL. COMPARING THIS TO THE STORM SYSTEM CURRENTLY
COMING IN...SNOW ACCUMULATIONS DO NOT LOOK LIKE THEY WILL BE NEARLY
AS HIGH FOR THE SECOND STORM. HOWEVER...WINDS ON THE BACK SIDE OF
THE SURFACE LOW LOOK TO BE MUCH STRONGER FOR SUNDAY AND MONDAY THAN
AT ANY POINT DURING THIS CURRENT STORM. TOOK A BLEND OF THE
GFS...CANADIAN AND EUROPEAN MODELS FOR WIND SPEED FORECASTS. THE
CANADIAN MODEL IS THE LOWEST WITH WIND SPEEDS WHILE THE EUROPEAN IS
MUCH HIGHER THAN BOTH THE CANADIAN AND THE GFS MODELS. THE EUROPEAN
MODEL IS SUGGESTING SUSTAINED SURFACE WIND SPEEDS OF 40 KTS ON THE
BACKSIDE OF THIS SYSTEM. AS A RESULT...INCREASED WINDS OVER THE CR
INIT PROCEDURE BY BLENDING THE MODELS AND THROUGH LOCAL
COLLABORATION. BY THE TIME THIS SYSTEM MOVES IN...THERE SHOULD BE
SOMEWHAT OF A CRUST OVER THE SNOW PACK FROM THE PREVIOUS SYSTEM. AS
A RESULT...ANY NEW SNOWFALL WILL LIKELY BLOW AROUND IN THE STRONG
WINDS SO HAVE MENTIONED PATCHY BLOWING SNOW FOR NOW. AGAIN...THIS
COULD BE ANOTHER WINTER STORM FOR THE REGION SO CONTINUE TO MONITOR
FORECAST UPDATES AS THE ACTIVE PATTERN CONTINUES.
TEMPERATURES SHOULD COOL A LITTLE MORE FOLLOWING THE NEXT STORM
SYSTEM AS STRONG NORTHWEST WINDS SHOULD PULL DOWN SOME COLD CANADIAN
AIR. WITH LOTS OF SNOW ON THE GROUND FROM THIS PREVIOUS
SNOW...SHOULD HAVE NO PROBLEM BRINGING IN THE COLD AIR. ANOTHER
DISTURBANCE WILL MOVE ACROSS THE REGION ON TUESDAY NIGHT AND INTO
WEDNESDAY. ONLY LIGHT SNOW HAS BEEN MENTIONED AS THIS SYSTEM IS TOO
FAR OUT TO GET A GOOD READ ON IT.
THANKS TO ALL FOR COLLABORATION THROUGH THE WHOLE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 439 AM MST WED FEB 20 2013
CONDITIONS HAVE BEGUN TO DETERIORATE AT AND SOUTH OF KGLD. THESE CONDITIONS
ARE EXPECTED TO WORSEN AND SPREAD NORTH TO KMCK BY LATE MORNING. MVFR
CONDITIONS WILL TRANSITION TO IFR TO LIFR CONDITIONS BY LATE MORNING
AND ARE EXPECTED TO CONTINUE FOR THE REMAINDER OF THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER STORM WARNING UNTIL 5 PM MST /6 PM CST/ THURSDAY FOR
KSZ001>004-013>016-027>029-041-042.
CO...WINTER STORM WARNING UNTIL 5 PM MST THURSDAY FOR COZ090>092.
NE...WINTER STORM WARNING UNTIL 5 PM MST /6 PM CST/ THURSDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
404 AM MST WED FEB 20 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 404 AM MST WED FEB 20 2013
MAJOR WINTER STORM WILL BE THE FORECAST CONCERN. SATELLITE SHOWING A
PROGRESSIVE FLOW OVER MOST OF THE PACIFIC WHICH TRANSITIONS TO A
MUCH MORE AMPLIFIED FLOW OVER NORTH AMERICA. SYSTEM THAT WILL BE
INFLUENCING OUR WEATHER THROUGH THURSDAY IS DIGGING ACROSS
CALIFORNIA AT THIS TIME.
AT JET LEVEL...MODELS APPEAR TO BE INITIALIZING FINE WITH THE MAIN
JET SEGMENT STILL OVER WATER. MODELS DID FINE AT MID LEVELS THROUGH
06Z ALTHOUGH INITIALLY THE MODELS TENDED TO HAVE THE CALIFORNIA
SYSTEM A LITTLE TOO FAR SOUTH. SREF AND NAM WERE DOING THE BEST ON
THE SURFACE PRESSURE/WIND FIELD WITH THE CANADIAN BETTER...NOT
PERFECT...WITH THE DEWPOINTS. THE RUC AND HRRR WERE DOING WELL IN
CATCHING THE DEVELOPING PRECIPITATION AND WERE ECHOING/CONFIRMING
THE LARGER SCALE MODELS. THIS SYSTEM IS STILL NOT OVER LAND YET SO AM
STILL NERVOUS ABOUT WHAT THIS SYSTEM WILL DO DESPITE THE GOOD MODEL
AGREEMENT. THE MEMORY OF LAST YEARS LESS THAN EXPECTED FEBRUARY STORM
IS STILL FRESH IN MY MEMORY.
TODAY/TONIGHT...MAJOR WINTER STORM AND WINTER STORM WARNING ON TRACK.
INITIALLY THE ONE THING THAT BOTHERED WAS THE DRY SLOT/PUNCH COMING
IN FROM THE SOUTHWEST PER SATELLITE AND UPPER AIR ANALYSIS. ON THE
POSITIVE SIDE OF THAT...THE LAST FEW HOURS THE SATELLITE IS SHOWING
CLOUDS INCREASING AND COOLING TO OUR SOUTH AND WEST. THERE HAS BEEN
PERIODIC LIGHTNING STRIKES TO OUR SOUTHWEST AS WELL. OVER WESTERN NEW
MEXICO. THERE IS ALSO SPORADIC LIGHTNING STRIKES OVER EASTERN ARIZONA
AND WESTERN NEW MEXICO.
IN GENERAL...A LONG TERM...MODERATE TO SOMETIMES HEAVY...SNOW EVENT
LOOKS TO BE UNFOLDING AT THIS TIME. WHAT IS EXTREMELY SCARY AND
ENCOURAGE IS THE MODEL AGREEMENT IN QPF/SNOW AMOUNT PLACEMENT BY
THE LARGE SCALE DETERMINISTIC MODELS AND AS STATED ABOVE BEING
SUPPORTED THE SMALL SCALE MODEL OUTPUT. MODEL OUTPUT FOR TODAY CAME
IN A LITTLE COLDER AND ONLY SUPPORTED A BRIEF AND LIGHT ACCUMULATION
OF ICE WITH A CHANGE OVER TO SNOW EXPECTED BY THE MIDDLE OF THE DAY.
FIRST SHORTWAVE TROUGH WITH FAVORABLE THETA-E LAPSE RATES MOVE
THROUGH INTO THE MIDDLE OF THE DAY/EARLY THIS AFTERNOON. SO FORCING
AND INSTABILITY HAVE INCREASED. SO INCREASED SNOWFALL AMOUNTS
SIGNIFICANTLY FOR TODAY. IF MESOSCALE MODELS ARE CORRECT I MAY NOT
HAVE SNOWFALL AMOUNTS HIGH ENOUGH IN THE SOUTHEAST.
DAY SHIFT MENTIONED THE POSSIBILITY OF A BRIEF LULL. THIS LULL MAY
BE VERY BRIEF AND MAY NOT EVEN BE WORTH DEPICTING SINCE MOST BUT NOT
ALL MODEL OUTPUT IS SHOWING LEFT FRONT QUADRANT AFFECTING AT LEAST
THE SOUTHEAST HALF OF THE AREA FROM LATE AFTERNOON UNTIL NEAR/SHORTLY
AFTER 06Z. BY 12Z...MAIN JET IS EAST OF THE AREA WITH SUBSIDENT AREA
OF JET OVER THE AREA. HOWEVER...BY LATE LATER TONIGHT THE 700 MB LOW
MOVES INTO A VERY FAVORABLE POSITION FOR A MODERATE TO HEAVY SNOW
BAND TO DEVELOP AND THAT IS CONFIRMED BY FORCING/INSTABILITY
FORECASTS. CONSEQUENTLY POPS HAVE BEEN INCREASED TO 100 PERCENT
BEGINNING AT 18Z AND CONTINUING THROUGH THE NIGHT. FORCING...QPF
AND PROBABILITY OUTPUT SUPPORTS AND AS A RESULT AMOUNTS GOT
INCREASED. BLOWING SNOW WILL ALSO START AROUND MIDDAY AND WILL
CONTINUE THROUGH THE END OF THIS PERIOD. HIGH TEMPERATURES WILL RISE
LITTLE TODAY.
THURSDAY/THURSDAY NIGHT...MODELS ARE SLOWER AND IN GOOD AGREEMENT
WITH THE MID LEVEL LOW PLACEMENT. IN FACT IN SOME PLACES...THE
MODERATE TO HEAVY SNOW MAY NOT BEGIN UNTIL EARLY THIS PERIOD. HAD
TO KEEP KEEP IN MUCH HIGHER POPS THROUGH MOST OF THE DAY...
ESPECIALLY IN THE EAST WITH BLOWING CONTINUING TO BE A PROBLEM. THERE
WILL BE SOME LINGERING LIGHT SNOW IN THE EAST IN THE EVENING. VERY
COLD MAXES WILL BE IN PLACE WITH DROPPING WIND CHILL TEMPERATURES
THROUGH THE DAY AND MUCH BELOW ZERO DURING THE NIGHT. MAY GET CLOSE
TO WIND CHILL ADVISORY CRITERIA THURSDAY NIGHT. MODELS SAYING WINDS
WILL STAY UP ENOUGH DURING THE NIGHT BUT DO NOT BUY THAT. WENT
BELOW LOW TEMPERATURE GUIDANCE BUT THE EXPECTED SNOW FIELD I DOUBT
THEY WILL BE LOW ENOUGH.
FRIDAY...WILL BE DRY FOR THE DAY. LOWERED MAXES...ESPECIALLY IN THE
EAST. HOWEVER...DO EXPECT THIS MAXES WILL BE TOO WARM BUT AT LEAST
STARTED TO TREND COLDER.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 308 AM MST WED FEB 20 2013
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS THE TRI-STATE AREA
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK AS THE OVERALL ATMOSPHERIC
PATTERN IS FAVORABLE FOR A SERIES OF DISTURBANCES TO MOVE THROUGH.
ON FRIDAY NIGHT...A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS
EASTERN COLORADO AND WESTERN KANSAS. AT THE PRESENT TIME...MODELS
ARE SUGGESTING THAT THERE IS A CHANCE SOME PRECIPITATION COULD SNEAK
INTO FAR SOUTHERN PORTIONS OF THE FORECAST AREA SO HAVE INCLUDED
SLIGHT CHANCE POPS. PRECIPITATION SHOULD BE FAIRLY LIGHT SO NO MAJOR
ADDITIONAL ACCUMULATIONS ARE EXPECTED WITH THIS WEAK SHORTWAVE.
CONTINUED COLD TEMPERATURES ARE EXPECTED...AND HAVE LOWERED
TEMPERATURES FROM GUIDANCE ACCORDINGLY DUE TO EXPECTED SNOW COVER
AND MODELS NOT QUITE PICKING UP ON THIS SNOW COVER YET.
ATTENTION THEN TURNS TO ANOTHER POTENTIALLY BIG WINTER STORM FOR
SUNDAY THROUGH MONDAY NIGHT. A STRONG LONGWAVE TROUGH WILL DIVE
SOUTH ACROSS THE PACIFIC NORTHWEST ON FRIDAY...ACROSS THE ROCKY
MOUNTAINS ON SATURDAY AND INTO THE CENTRAL PLAINS BY SUNDAY. MODELS
ARE SUGGESTING THAT AS THIS LONGWAVE TROUGH EJECTS OVER THE
PLAINS...STRONG CYCLOGENESIS SHOULD OCCUR IN THE LEE OF THE ROCKIES.
THERE ARE STILL SOME DIFFERENCES WITH RESPECT TO LOCATION OF THE
SURFACE LOW AND 500 MB TROUGH BETWEEN THE GFS...EURO AND CANADIAN.
AT THIS TIME...BELIEVE THAT THE GFS RUN IS A LITTLE QUICK AND A
LITTLE TOO FAR NORTH. THE CANADIAN AND EUROPEAN MODELS ARE IN
SOMEWHAT FAIR AGREEMENT BUT THERE ARE A FEW DIFFERENCES BETWEEN
THESE TWO AS WELL. COMPARING THIS TO THE STORM SYSTEM CURRENTLY
COMING IN...SNOW ACCUMULATIONS DO NOT LOOK LIKE THEY WILL BE NEARLY
AS HIGH FOR THE SECOND STORM. HOWEVER...WINDS ON THE BACK SIDE OF
THE SURFACE LOW LOOK TO BE MUCH STRONGER FOR SUNDAY AND MONDAY THAN
AT ANY POINT DURING THIS CURRENT STORM. TOOK A BLEND OF THE
GFS...CANADIAN AND EUROPEAN MODELS FOR WIND SPEED FORECASTS. THE
CANADIAN MODEL IS THE LOWEST WITH WIND SPEEDS WHILE THE EUROPEAN IS
MUCH HIGHER THAN BOTH THE CANADIAN AND THE GFS MODELS. THE EUROPEAN
MODEL IS SUGGESTING SUSTAINED SURFACE WIND SPEEDS OF 40 KTS ON THE
BACKSIDE OF THIS SYSTEM. AS A RESULT...INCREASED WINDS OVER THE CR
INIT PROCEDURE BY BLENDING THE MODELS AND THROUGH LOCAL
COLLABORATION. BY THE TIME THIS SYSTEM MOVES IN...THERE SHOULD BE
SOMEWHAT OF A CRUST OVER THE SNOW PACK FROM THE PREVIOUS SYSTEM. AS
A RESULT...ANY NEW SNOWFALL WILL LIKELY BLOW AROUND IN THE STRONG
WINDS SO HAVE MENTIONED PATCHY BLOWING SNOW FOR NOW. AGAIN...THIS
COULD BE ANOTHER WINTER STORM FOR THE REGION SO CONTINUE TO MONITOR
FORECAST UPDATES AS THE ACTIVE PATTERN CONTINUES.
TEMPERATURES SHOULD COOL A LITTLE MORE FOLLOWING THE NEXT STORM
SYSTEM AS STRONG NORTHWEST WINDS SHOULD PULL DOWN SOME COLD CANADIAN
AIR. WITH LOTS OF SNOW ON THE GROUND FROM THIS PREVIOUS
SNOW...SHOULD HAVE NO PROBLEM BRINGING IN THE COLD AIR. ANOTHER
DISTURBANCE WILL MOVE ACROSS THE REGION ON TUESDAY NIGHT AND INTO
WEDNESDAY. ONLY LIGHT SNOW HAS BEEN MENTIONED AS THIS SYSTEM IS TOO
FAR OUT TO GET A GOOD READ ON IT.
THANKS TO ALL FOR COLLABORATION THROUGH THE WHOLE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1015 PM MST TUE FEB 19 2013
KGLD...VFR EXPECTED THROUGH 11Z WITH CIGS QUICKLY BECOMING MVFR BY
12Z AND IFR/VLIFR IN SNOW/BLOWING SNOW/FOG BY 14Z AND CONTINUING
THROUGH ROUGHLY 18Z. FROM 19Z THROUGH 00Z IT APPEARS THERE WILL BE
A LULL IN PRECIPITATION BUT ABUNDANT LOW LEVEL MOISTURE WILL
PREVENT CIGS AND VIS FROM RISING INTO VFR RANGE. NEXT BATCH OF
PRECIPITATION MOVES IN AROUND 00Z WITH MODERATE TO PERHAPS SOME
HEAVY SNOW IN THE 02Z-06Z TIME FRAME. WINDS THROUGH THE PERIOD
WILL REMAIN FROM THE SOUTHEAST AT 20-25G30-35 KT RANGE.
KMCK...VFR EXPECTED THROUGH 12Z WITH CIGS QUICKLY BECOMING MVFR
BY 13Z AND IFR/VLIFR IN SNOW/BLOWING SNOW/FOG BY 17Z AND
CONTINUING THROUGH 00Z. FROM 00Z-02Z IT APPEARS THERE WILL BE A
LULL IN PRECIPITATION BUT ABUNDANT LOW LEVEL MOISTURE WILL PREVENT
CIGS AND VIS FROM RISING INTO VFR RANGE. THE NEXT BATCH OF
PRECIPITATION MOVES IN FROM THE SOUTH/SOUTHWEST IN THE 03Z-06Z
TIME FRAME WHEN MODERATE TO POSSIBLY HEAVY SNOW WILL FALL. WINDS
THROUGH THE PERIOD FROM THE EAST AROUND 15KTS AT THE BEGINNING OF
THE TAF PERIOD WITH WINDS INCREASING INTO THE 20-30KT RANGE BY 17Z
AND CONTINUING THROUGH THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER STORM WARNING FROM 5 AM MST /6 AM CST/ WEDNESDAY TO 5 PM
MST /6 PM CST/ THURSDAY FOR KSZ001>004-013>016-027>029-041-
042.
CO...WINTER STORM WARNING FROM 5 AM WEDNESDAY TO 5 PM MST THURSDAY
FOR COZ090>092.
NE...WINTER STORM WARNING FROM 5 AM MST /6 AM CST/ WEDNESDAY TO 5 PM
MST /6 PM CST/ THURSDAY FOR NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...DDT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
448 AM CST WED FEB 20 2013
.DISCUSSION...
.TODAY THROUGH THURSDAY NIGHT...
...MAJOR WINTER STORM STILL ON TRACK TO IMPACT THE AREA LATER TODAY
INTO THURSDAY...
WATER VAPOR IMAGERY SHOWING ONE SHORTWAVE TROUGH LIFTING NORTHEAST
ACROSS THE SOUTHERN HIGH PLAINS WHICH IS AIDING THE INITIAL
DEVELOPMENT OF LIGHT SNOW ACROSS PORTIONS OF SOUTHWEST KS INTO OK.
VERY DRY AIR EXTENDS NORTHEAST OF THIS SNOW AREA INTO NORTHEAST KS.
THIS DRY AIR AND WEAKER FORCING WILL LIMIT THE NORTHEASTWARD EXTENT
OF THE MORE SIGNIFICANT SNOWFALL TODAY. THEREFORE ALTHOUGH THE SNOW
WILL GRADUALLY WORK NORTHEAST...IT WILL BE SLOW AND MAINLY BE LIMITED
TO THE SOUTHWEST 1/2 OF THE CWA WITH AMOUNTS GENERALLY LESS THAN AN
INCH. WATER VAPOR SHOWING STRONG SHORTWAVE TROUGH NOW PLUNGING
SOUTHEAST ACROSS SOUTHERN CA WHICH WILL MAKE AN EASTWARD TURN
TODAY...THEN A MORE NORTHEASTWARD TURN ON THURSDAY INTO THE CWA.
ALTHOUGH SNOW WILL SLOWLY INCREASE THROUGH THE NIGHT TONIGHT...THE
MAIN FORCING WILL ARRIVE LATE TONIGHT AND THROUGH THE MIDDAY HOURS
ON THURSDAY. STEEPER LAPSE RATES...INCREASING INSTABILITY AND STRONG
FRONTOGENETICAL FORCING IN THIS LAYER WILL COINCIDE WITH PERSISTENT
AND DEEP LIFT AND ZONE OF STRONGER INSTABILITY AND DENDRITIC GROWTH
ZONE. AS A RESULT...EXPECT TO SEE A BAND OF SNOWFALL RATES OF ONE TO
2 INCHES PER HOUR TO LIFT AHEAD OF THE STRONG PVA ACROSS A GOOD
PORTION OF THE CWA...PRIMARILY IN THE SUNRISE TO MIDDAY THURSDAY
TIMEFRAME. THIS AREA OF CONVECTIVE SNOW COULD PRODUCE AN ADDITIONAL
4 TO 6 INCHES OF ACCUMULATION. THE PRIMARY DRY SLOT HAS SHIFTED MORE
SOUTHEAST OF MORE RECENT MODEL RUNS...AND THIS MAY SUPPORT MORE
"LIGHTER" SNOW INTO THE LATE AFTERNOON AND EVENING HOURS BEFORE IT
SHIFTS NORTHEAST OF THE CWA. THE NORTH CENTRAL COUNTIES WILL REMAIN
ALL SNOW AND IN THE SNOW LONGER THROUGH THURSDAY AND WILL RECEIVE
THE MOST SNOW...12-15 INCHES...WHILE THE EAST COUNTIES SHOULD SEE A
PERIOD OF SNOW/SLEET AND POSSIBLY SOME BRIEF FREEZING RAIN (SOUTH OF
I 35) TONIGHT/EARLY THURSDAY BEFORE GOING BACK TO ALL SNOW THURSDAY
WHICH WOULD REDUCE THE SNOW TOTALS THERE TO 4 TO 6 INCHES IN
PORTIONS OF COFFEY AND ANDERSON COUNTIES. SNOWFALL TOTALS OF 6 TO 12
INCHES ARE EXPECTED ELSEWHERE. BETWEEN THE SNOWFALL RATES AND
WIND...VISIBILITIES WILL BE VERY POOR AT TIMES THURSDAY.
AFTER THIS STORM DEPARTS THURSDAY NIGHT...IT WILL BE DRY FRIDAY INTO
SATURDAY BEFORE ANOTHER STORM BRINGS ANOTHER ROUND OF RAIN AND/OR
SNOW TO THE CWA SUNDAY AND MONDAY. THIS SYSTEM MAY ALSO BE
FAIRLY STRONG...BUT SHOULD NOT HAVE AS MUCH COLD AIR ASSOCIATED WITH
ITS ARRIVAL...SO IT IS MUCH TOO EARLY TO MAKE ANY ESTIMATES OF ANY
AMOUNTS THIS FAR OUT.
63
&&
.AVIATION...
.AVIATION...
THE NAM AND RAP ARE TRENDING SLIGHTLY SLOWER WITH THE SYSTEM AND DO
NOT BRING THE SATURATION OR VERTICAL MOTION INTO THE TERMINALS UNTIL
LATE IN THE PERIOD. BECAUSE OF THIS WILL KEEP TOP AND FOE VFR DUE TO
DRY LOW LEVELS. THINK SOME LIGHT SNOW SHOULD BEGIN AT MHK BEFORE
06Z. ALTHOUGH THE STRONGER FORCING WILL BE AFTER 06Z SO ONLY HAVE
MVFR CONDITIONS WITH THE SNOW AT THIS POINT. AM FAIRLY CONFIDENT TOP
AND FOE WILL REMAIN VFR UNTIL 06Z THU. TIMING THE BEGINNING OF THE
SN IN MHK IS A LITTLE LESS CLEAR.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT CST
THURSDAY NIGHT FOR KSZ010>012-024-026-039-040.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST THURSDAY
FOR KSZ008-009-020>023-034>038-054>056-058-059.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1110 PM CST TUE FEB 19 2013
...MAJOR WINTER STORM DEVELOPING FOR THE AREA WEDNESDAY NIGHT
THROUGH THURSDAY...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
THE NAM AND RAP ARE TRENDING SLIGHTLY SLOWER WITH THE SYSTEM AND DO
NOT BRING THE SATURATION OR VERTICAL MOTION INTO THE TERMINALS UNTIL
LATE IN THE PERIOD. BECAUSE OF THIS WILL KEEP TOP AND FOE VFR DUE TO
DRY LOW LEVELS. THINK SOME LIGHT SNOW SHOULD BEGIN AT MHK BEFORE
06Z. ALTHOUGH THE STRONGER FORCING WILL BE AFTER 06Z SO ONLY HAVE
MVFR CONDITIONS WITH THE SNOW AT THIS POINT. AM FAIRLY CONFIDENT TOP
AND FOE WILL REMAIN VFR UNTIL 06Z THU. TIMING THE BEGINNING OF THE
SN IN MHK IS A LITTLE LESS CLEAR.
WOLTERS
&&
.PREV DISCUSSION... /358 PM CST TUE FEB 19 2013/
DRY COOL AND BREEZY CONDITIONS CONTINUE ACROSS THE FORECAST AREA
TODAY. WITH SUCH LOW DEWPOINTS IN THE SINGLE DIGITS...RELATIVE
HUMIDITIES HAVE DROPPED INTO THE 22-30% RANGE THIS AFTERNOON ACROSS
MUCH OF NORTHEAST KANSAS. FIRE DANGER REMAINS HIGH FOR THIS
AFTERNOON.
TONIGHT...WITH CLEAR SKIES AND THE COOL DRY AIRMASS SLIDING ACROSS
THE NORTHERN PLAINS...THINK TEMPERATURES WILL FALL INTO THE SINGLE
DIGITS BEFORE CLOUDS START TO INCREASE FROM THE WEST BY SUNRISE.
67
WEDNESDAY TO THURSDAY NIGHT...WINTER STORM REMAINS ON TRACK FOR
MAJOR IMPACTS TO THE AREA...WITH EACH RUN ONLY INCREASING THE ODDS.
THE TREND FOR A SLIGHTLY SLOWER AND FARTHER SOUTH TRACK
REMAIN...WITH THE STRONG PV ANOMALY /1.5 PVU SURFACE DOWN TO NEAR
650MB/ ROTATES CYCLONICALLY AROUND THE SYSTEM AND REACHES CENTRAL
KANSAS MIDDAY THURSDAY. STRONG LOW-MID LEVEL ISENTROPIC LIFT
DEVELOPS UNDER DIFFLUENT UPPER FLOW FROM WEDNESDAY INTO EARLY
THURSDAY WITH STRONG Q-VECTOR CONVERGENCE COMING IN UNDER INCREASING
UPPER LEVEL LAPSE RATES AND SOME SUGGESTIONS OF A TROWAL AND COUPLED
UPPER JET STREAKS LATE WEDNESDAY NIGHT INTO THURSDAY. LIFT SLOWLY
DIMINISHES LATE THURSDAY INTO THURSDAY NIGHT FOR DECREASING
PRECIPITATION...BUT THE FARTHER SOUTHEAST TRACK KEEPS THE ICE
CRYSTAL FORMATION GOING INTO THE EVENING. MOISTURE STILL NOT AN
ISSUE IN THE MIDDLE AND UPPER LAYERS BY SUNSET WEDNESDAY...BUT THE
ONSET OF MEASURABLE PRECIPITATION REMAINS A FORECAST CONCERN. MODELS
SURFACE DEWPOINT PROGS SHOWING AT LEAST 15F SPREADS OVER NORTHEAST
KANSAS AT 0Z THURSDAY. MODELS TEND TO BE TOO SLOW WITH THE ONSET OF
PRECIPITATION IN ISENTROPIC LIFT EVENTS...AND WILL KEEP CHANCES
HIGHER THAN GUIDANCE FOR WEDNESDAY NIGHT. JUST HOW MUCH ACCUMULATES
WEDNESDAY AFTERNOON IN THE KCNK/KSLN AREAS IS NOT CERTAIN EITHER AS
THE COLUMN SATURATES EARLIER BUT STILL NOT PERSISTENTLY THERE...AND
BELIEVE AMOUNTS BEFORE SUNRISE WILL BE MINOR. THE OTHER PRIMARY
ISSUE OF THE WARM NOSE REMAINS BUT CONTINUES TO BE SHUNTED FARTHER
SOUTH WITH EACH MODEL CYCLE...AND GETTING ANYTHING MORE THAN TRACE
AMOUNTS NORTHEAST OF KTOP IS BECOMING INCREASINGLY UNLIKELY. AS
ALLUDED TO...HIGHEST ACCUMULATIONS ARE EXPECTED IN THE LATE
WEDNESDAY NIGHT TO MID AFTERNOON THURSDAY PERIODS AS THE STRONGER
DYNAMICS COME IN. WINDS STILL ON TRACK TO INCREASE...BUT GUSTS
BEYOND 30MPH AND BLOWING OF THE SOMEWHAT LOW SNOW-TO-WATER RATION
SNOW KEEPS THE BLOWING SNOW THREAT IN CHECK. CONFIDENCE IN HEAVY
SNOW FOR THE BULK OF THE AREA AND MODERATE SNOWS AND SOME SLEET AND
ICE SOUTHEAST LEADS TO WARNING ISSUANCE.
65
FRIDAY THROUGH TUESDAY...TEMPORARY LULL IN THE ONGOING ACTIVE
WEATHER PATTERN OVER NORTHEAST KANSAS FRIDAY EVENING INTO SATURDAY
NIGHT. UPPER LEVEL RIDGE BUILDS EASTWARD ACROSS THE CENTRAL CONUS
DURING THE FIRST HALF OF THE WEEKEND. HIGH TEMPERATURES WERE TRENDED
DOWN A FEW DEGREES TO ACCOUNT FOR THE SNOW COVER ON THE GROUND
DURING THIS TIME. WEAK SOUTHERLY WINDS AND SUNNY SKIES WILL ALLOW
FOR SOME SNOW COVER TO MELT ON SUNDAY AFTERNOON WITH HIGHS EXPECTED
FROM THE LOW 30S IN NORTH CENTRAL PORTIONS...TO THE LOW 40S IN THE
FAR EAST CENTRAL COUNTIES OF THE CWA. MUCH UNCERTAINTY REMAINS IN
THE NEXT NEGATIVELY TILTED TROUGH EXPECTING TO IMPACT THE AREA AT
THE END OF THE WEEKEND CONTINUING INTO MONDAY. EXTENDED MODELS ARE
HAVING A DIFFICULT TIME RESOLVING TIME DIFFERENCES WITH THE 12Z
ECMWF TRENDING SLOWER AND DEEPER OVERNIGHT SUNDAY WHILE THE 12Z GFS
IS WEAKER AND ARRIVES BY SUNDAY AFTERNOON. ATTM...SIDED CLOSER TO
CONSISTENCY AND THE COOLER GFS SOLUTION DUE TO THE FACT SNOW COVER
STILL ON THE GROUND SHOULD KEEP TEMPS NEAR THE FREEZING MARK AND
THEREFORE SNOWFALL TOWARDS THE NORTH CENTRAL AREAS WITH RAIN MIXED
WITH SNOW FOR MOST OF NORTHEAST KANSAS. PORTIONS OF EAST CENTRAL
AREAS WERE WARM ENOUGH FOR RAIN TO BE INSERTED. SYSTEM CLEARS BY
MONDAY EVENING WITH TEMPERATURES REMAINING BELOW NORMAL WITH HIGHS
IN THE UPPER 30S AND LOW 40S. OVERNIGHT LOWS ARE IN THE 20S TO LOW
30S SUNDAY AND MONDAY MORNING.
JB
&&
.AVIATION...
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM MIDNIGHT WEDNESDAY NIGHT TO MIDNIGHT
CST THURSDAY NIGHT FOR KSZ010>012-024-026-039-040.
WINTER STORM WARNING FROM 6 PM WEDNESDAY TO 6 PM CST THURSDAY
FOR KSZ008-009-020>023-034>038-054>056-058-059.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
331 PM EST WED FEB 20 2013
.Short Term (Tonight through Thursday Night)...
Issued at 300 PM EST Wed Feb 20 2013
...A Brief Period of Wintry Weather Coming North of the I-64
Corridor...
What a mess as far as dealing with winter weather, as our next
system will bring it`s winter weather transition zone right across
our forecast area Thursday afternoon to late Thursday night.
Until then, the main forecast issue tonight will be cloud cover.
Shield of mid/high clouds moving in now is not forecast to last all
night. The RAP is advertising additional lower level clouds moving
in from the north, a low stratus, which right now is associated with
the flow coming off Lake Michigan. Will lean toward the rest of the
guidance, which keeps us clearer, overnight, except over the far
north. Then mid clouds should increase again as the system mentioned
above starts to influence our weather.
The atmosphere will saturate from above as an occluded front
approaches from the west. Deep isentropic ascent ahead of this front
will allow precipitation to start west of the I-65 corridor by late
afternoon. With the onset of this precip, expect temperatures to
drop a couple of degrees, which will allow for a mix of sleet/snow
across the north and cold rain down south. By 00Z, warm air aloft
will help to melt the deep freezing layer, allowing for the chance
for freezing rain across the north. As the night goes on, the warm
air will deepen and expect a transition over the just rain areawide
by around 09Z.
Forecast uncertainty remains high enough to keep us from issuing an
advisory. Went under guidance for temperatures at the surface and
aloft. If model forecast temperatures are true, and it should be
noted that our forecast errors for this forecast time period average
2-3 degrees, than much more of the area will be mostly rain. Based
on this uncertainty, have decided to issue just a special weather
statement on the chance for winter weather and hold off on issuing a
third-period advisory.
.Long Term (Friday through Tuesday Night)...
Issued at 326 PM EST Wed Feb 20 2013
The beginning of the long term period will feature a strong
shortwave pushing north through the Northern Plains. In its wake, a
trough will amplify across the central CONUS this weekend which will
work into the Ohio Valley. Another upper ridge will amplify across
the Ohio Valley ahead of the next system set to affect the region
early next week.
A warm front will be lifting north through the region early Friday
morning, with the associated synoptic forcing/isentropic ascent
lifting north into Ohio. Therefore, precipitation will taper off
from southwest to northeast through the day as a dry slot works
into the region. Temperatures on Friday will be rather warm, as the
surface cold front will remain well off to the west, allowing for
southwesterly winds to aid in a quick warmup in the wake of the
morning precipitation.
The associated cold front will finally push through the region late
Friday into early Saturday. Another shortwave will swing through
the mean trough Saturday morning, which will induce secondary
surface low development across TN/GA. As this wave rides along the
departing cold front, it will act to stall its progress. In fact,
the 12Z suite of guidance is suggesting there may be enough moisture
kicked back into the region to produce some additional precipitation
across the Cumberland area as the shortwave and surface low pass
by. If this moisture were to get far enough north into the cooler
air, then some light freezing rain/drizzle could creep into the
northern Bluegrass region Saturday morning. However, this
probability looks rather low at this point and will leave
precipitation as all rain for now and confined to the far
east/southeast portions of the CWA.
A ridge will build across the region late Saturday through Monday,
providing calm and dry weather conditions. Temperatures will warm
each day through the weekend, as temperatures in the lower 40s on
Saturday warm into the middle 50s by Monday.
Another strong upper level wave will eject out into the Central and
Northern Plains on Monday. This system looks very similar to the
Thursday/Friday system, spreading a slug of precipitation north in
association with a wave of isentropic ascent atop the surface warm
front. This time, however, the cooler air will not be in place
ahead of the approaching warm front, so any and all precipitation
will remain rain. The surface cold front will push through late
Monday night into Tuesday morning, dropping temperatures back into
the upper 40s Tuesday afternoon.
The 20/12Z GFS advertises the surface low tracking across Indiana
and Ohio, which would bring some wrap-around precipitation to
portions of southern Indiana and northern Kentucky Tuesday into
early Wednesday. However, with a strong upper ridge in place, this
system will struggle dropping southeast like the GFS suggests.
Therefore, will favor the ECMWF and GFS ensembles, lifting the
surface low and its associated wrap-around precipitation further
north, thus keeping the forecast dry through the remainder of the
long term period.
&&
.Aviation (18Z TAF Issuance)...
Issued at 1215 PM EST Wed Feb 20 2013
A weak upper level disturbance will bring some high clouds to the
region the rest of this afternoon and into the early evening. High
pressure over south central Canada will have a ridge axis that will
shift from a KSDF/KLEX line early this afternoon east to the
KY/OH/WV border overnight. As this shift occurs, winds will switch
from northwesterly the rest of today to northeasterly by Thursday
morning. Clouds will increase by the end of the period as a front
approaches the region late Thursday afternoon. KSDF may get some
light rain, with continued VFR cigs, by the very end of the period,
but left it out of this TAF to keep it short.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......RJS
Long Term........KJD
Aviation.........RJS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1037 AM EST WED FEB 20 2013
.SYNOPSIS...
COLD UPPER LOW PRESSURE WILL CONTINUE TO SUPPORT SCATTERED SNOW
SHOWERS TODAY. THURSDAY LOOKS DRY WITH HIGH PRESSURE SLIDING OVER
THE REGION...BUT MORE PRECIPITATION CAN BE EXPECTED WITH A FRIDAY
WARM FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
WITH THE MID-MORNING UPDATE...ONLY SLIGHT CHANGES WERE MADE TO THE
FORECAST MAINLY FOR POPS...TEMPS...AND SKY COVER. DECIDED TO
HIGHLIGHT LIKELY POPS FOR THE FIRST PERIOD WITH SOME LAKE ENHANCED
SNOW REMAINING OVER MUCH OF THE REGION TODAY. WHILE MOST LOCATIONS
WILL BE IN AND OUT OF HEAVIER SNOWS...FELT THAT WITH BRIEF WHITE-
OUT CONDITIONS POSSIBLE...ANYTHING UNDER LIKELY WORDING WAS
INAPPROPRIATE. BOTH THE HI RES NAM AND HRRR SUGGEST THAT THE
SLIGHTLY MORE ORGANIZED BAND OVER CLEVELAND COULD SHIFT SOUTH AND
INTO A PART OF THE REGION TODAY. MAINTAINED CHANCE POPS WITH THIS
POSSIBLE AND CONTINUED HIGHER POPS FOR UPSLOPE IN THE MOUNTAINS
AND AREAS NORTH OF I-80.
THE UPPER LOW WITH ITS ROTATING VORT MAXES WILL CONTINUE TO SHIFT
TO THE EAST BY LATE TONIGHT. AS STRONG SUBSIDENCE TAKES
PLACE INVERSION HEIGHTS WILL LOWER ENDING SNOW SHOWERS IN MOST
LOCATIONS...BEYOND THE HIGHER ELEVATIONS...BY MIDNIGHT.
TEMPERATURES WILL CONTINUE TO RUN BELOW NORMAL TODAY AND TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
HIGH PRESSURE BUILDS OVERHEAD THURSDAY. WRM AIR ADVCTN WL BEGIN
TO KICK IN THU NGT AHD OF AN APRCHG WRMFNT. THIS FRONT PUSHES NE
THRU THE RGN FRI. SIDED WITH WARMER GFS/ECMWF GUIDANCE GIVEN TRACK
OF SFC LOW WELL TO OUR NW. CRITICAL THICKNESSES/PROFILES SHOW WE
WL PROB SEE A BRF PD OF FZRA FRI MRNG...WITH SN MIXED IN AT TIMES
ESP N OF I 80. PCPN SHOULD CHG TO RA MOST LOCATIONS BEFORE ENDG
FRI AFTN. MOISTURE IS LMTD...AND SYSTEM IS EXPD TO BE MOVG
QUICKLY...SO SGFNT AMNTS OF WINTRY PCPN NOT EXPD ATTM. TEMPS WL BE
BLW NORMAL TNGT INTO THU...REACHING NR NORMAL LVLS FRI.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
A LOW PRESSURE CENTER MOVING SLOWLY THROUGH THE GREAT LAKES WILL
BRING A CHANCE OF RAIN AND SNOW SHOWERS FOR INTO SATURDAY NIGHT.
HIGH PRESSURE WILL PROVIDE DRY WEATHER FOR SUNDAY THROUGH MONDAY
WITH TEMPERATURES A BIT ABOVE NORMAL. A COLD FRONT PUSHING TOWARD
THE DISTRICT WILL BRING A CHANCE OF SHOWERS MONDAY NIGHT INTO
TUESDAY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
MVFR STRATOCU AND SCT -SHSN WL PERSIST OVR UPR OH VALLEY TERMINALS
THROUGH TDA AS A COLD UPR TROF AXIS SLIDES ACRS THE REGION. VSBY IN
THOSE SHSN MAY BRIEFLY DROP INTO THE IFR RANGE. IN ADDITION...AS
THE MIXING LYR AND TIGHT PRES GRADIENT WL BE MAINTAINED...SFC WND
GUSTS TO ARND 25 KT CAN ALSO BE ANTICIPATED THROUGHOUT THE TAF PD.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
LINGERING RESTRICTIONS ARE ANTICIPATED INTO THU...BUT BLDG HIGH PRES
WL YIELD IMPROVEMENTS AND DIMINISHED WIND. THOSE IMPROVEMENTS LK TO
BE BRIEF THOUGH AS LOW PRES DIGGING OVR THE GREAT LAKES IS EXPECTED
TO INCRS PCPN CHC FOR THE REGION AGAIN BY FRIDAY. GRADUAL
IMPROVEMENT IS ANTICIPATED FOR THE WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1023 PM EST THU FEB 21 2013
.SYNOPSIS...
ISSUED AT 330 PM EST THU FEB 21 2013
SNOW WILL SPREAD NORTHEAST ACROSS THE AREA OVERNIGHT INTO FRIDAY
MORNING. A QUICK 1 TO 2 INCHES OF SNOW MAY AFFECT THE FRIDAY MORNING
COMMUTE. THIS WILL BE FOLLOWED BY A TRANSITION TO FREEZING DRIZZLE
LATER IN THE DAY. A CHANCE OF WINTRY PRECIPITATION WILL PERSIST
THROUGH SATURDAY NIGHT. THE NEXT CHANCES FOR PRECIPITATION WILL BE
MONDAY NIGHT AND TUESDAY...WHEN A MIX OF RAIN AND SNOW IS EXPECTED.
TEMPERATURES WILL MODERATE NEXT WEEK WITH HIGHS REACHING THE UPPER
30S.
&&
.UPDATE...
ISSUED AT 1022 PM EST THU FEB 21 2013
NO CHANGES TO THE HEADLINES. REGIONAL RADAR SHOWS A BAND OF
SNOW...ON THE LEADING EDGE...AND FREEZING RAIN MOVING NORTH ACROSS
INDIANA. THE NRN FRINGE IS THINNING AS IT MOVES NORTH AND WILL
LIKELY TAKE A WHILE TO GET TO THE SRN CWA. STILL LOOKING FOR PCPN
TO BEGIN AFTER 08-09Z SOUTH OF I-94 AND MOVE NORTH.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM EST THU FEB 21 2013
WILL BE ISSUING A WINTER WEATHER ADVISORY FOR OUR SOUTHERN CWFA TO
ACCOUNT FOR POSSIBLE BRIEF INTENSE SNOWFALL DURING THE FRIDAY
MORNING COMMUTE. CALIBRATED SREF GUIDANCE SHOWS GREATER THAN 1 INCH
PER HOUR SNOWFALL PROBABILITIES ACROSS OUR SOUTHERN COUNTY WARNING
AREA IN THE 12-15Z TIMEFRAME FRIDAY. ALSO LATEST GRR SNOWTOOL
GUIDANCE FROM THE RAP SUGGESTS THAT 1"/HR RATES WILL BE POSSIBLE
AFTER 10Z. ADVISORY WILL BE COMING OUT SHORTLY.
AFTER THIS INITIAL BURST OF SNOWFALL...AGREE WITH THE PREVIOUS
DISCUSSION THAT IMPACTS SHOULD BE MINOR. THE RESPONSIBLE SYSTEM
CURRENTLY IN THE PLAINS WILL FILL AS IT SHEARS NORTHEAST. BEHIND THE
NARROW BUT POTENTIALLY INTENSE BAND OF WARM ADVECTION SNOW...ALL BUT
THE EXTREME NORTHERN PART OF THE FORECAST AREA DESATURATES IN THE
DGZ DURING THE LATE MORNING...MEANING A TRANSITION TO FREEZING
DRIZZLE AND THEN POSSIBLY DRIZZLE AS SURFACE TEMPERATURES WARM. ICE
ACCUMULATION IS EXPECTED TO BE MINIMAL... ESPECIALLY WITH THE
MITIGATING EFFECTS OF SNOW COVER...RESIDUAL SALT...AND DAYTIME
INSOLATION ALL DISCUSSED IN THE PREVIOUS AFD.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM EST THU FEB 21 2013
A HIGH PRESSURE RIDGE WILL PRODUCE DRY WX WITH SEASONABLY COOL
TEMPERATURES SUNDAY THROUGH SUNDAY NIGHT. LOW PRESSURE TRACKING NE
INTO OUR REGION WILL BRING A SLIGHT CHANCE FOR A MIX OF LIGHT RAIN
AND LIGHT SNOW AS EARLY AS MONDAY BASED ON 12Z GFS GUIDANCE.
HOWEVER THE MUCH BETTER CHANCE FOR MIXED PCPN SHOULD HOLD OFF UNTIL
LATE MONDAY NIGHT AND TUESDAY AS SUGGESTED BY THE SLOWER AND
PREFERRED ECMWF 12Z GUIDANCE SOLUTION (WHICH IS CONSISTENT WITH PCPN
TIMING FROM THE 00Z RUN).
TEMPS WILL UNDERGO A GRADUAL MODERATING TREND DURING THE EARLY TO
MIDDLE PORTION OF NEXT WEEK WITH MAX TEMPS EXPECTED TO REACH THE
UPPER 30S TO LOWER 40S BY TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 808 PM EST THU FEB 21 2013
CONDITIONS RANGE FROM VFR AT MOST OF THE TAF SITES THIS EVENING TO
MVFR AT KAZO. THE TREND WILL BE TOWARD LOWERING CEILINGS THROUGH
THE COURSE OF THE NIGHT WITH MVFR CONDITIONS AT LEAST AT ALL SITES
BY 10Z. A BAND OF MODERATE TO OCCASIONALLY HEAVY SNOW WILL PUSH
THROUGH THE TAF SITES BETWEEN 09Z AND 15Z...SWEEPING NORTHEAST
WITH TIME. KAZO WILL BE IMPACTED FIRST BY THE SNOW BAND AROUND
09Z. CONDITIONS WILL DIP INTO THE IFR CATEGORY AS THE BAND MOVES
THROUGH WITH THE POTENTIAL FOR VSBY/S TO DROP BELOW 1SM. CEILINGS
WILL DIP BELOW 1000FT FRIDAY MORNING...AND WILL STAY THAT WAY
THROUGH THE AFTERNOON. FREEZING DRIZZLE WILL LIKELY FOLLOW THE
SNOW ON FRIDAY AT LEAST FOR SEVERAL HOURS IN THE LATE MORNING AND
EARLY AFTERNOON. THERE IS THE POTENTIAL THAT THE FREEZING DRIZZLE
COULD LINGER MUCH OF THE DAY AS TEMPERATURES WILL ONLY RISE TO
AROUND THE FREEZING MARK IN THE AFTERNOON.
&&
.MARINE...
ISSUED AT 359 PM EST THU FEB 21 2013
AFTER FURTHER CONSIDERATION...ISSUED A NEW SMALL CRAFT ADVISORY BEGINNING
TONIGHT TO ACCOUNT FOR STRENGTHENING EAST WINDS TOWARDS MORNING. ALTHOUGH
WAVE GROWTH WILL BE LIMITED SOMEWHAT BY POOR FETCH...SUSTAINED WINDS
WELL IN EXCESS OF 20 KTS TOWARDS SUNRISE WILL GREATLY INCREASE THE
HAZARD.
&&
.HYDROLOGY...
ISSUED AT 330 PM EST THU FEB 21 2013
WITH ADDITIONAL QPF EXPECTED TO STAY WELL UNDER HALF AN INCH...THERE
ARE NO CONCERNS AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST FRIDAY FOR MIZ050-
056>059-064>067-071>074.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LMZ844>849.
&&
$$
UPDATE...93
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
809 PM EST THU FEB 21 2013
.SYNOPSIS...
ISSUED AT 330 PM EST THU FEB 21 2013
SNOW WILL SPREAD NORTHEAST ACROSS THE AREA OVERNIGHT INTO FRIDAY
MORNING. A QUICK 1 TO 2 INCHES OF SNOW MAY AFFECT THE FRIDAY MORNING
COMMUTE. THIS WILL BE FOLLOWED BY A TRANSITION TO FREEZING DRIZZLE
LATER IN THE DAY. A CHANCE OF WINTRY PRECIPITATION WILL PERSIST
THROUGH SATURDAY NIGHT. THE NEXT CHANCES FOR PRECIPITATION WILL BE
MONDAY NIGHT AND TUESDAY...WHEN A MIX OF RAIN AND SNOW IS EXPECTED.
TEMPERATURES WILL MODERATE NEXT WEEK WITH HIGHS REACHING THE UPPER
30S.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM EST THU FEB 21 2013
WILL BE ISSUING A WINTER WEATHER ADVISORY FOR OUR SOUTHERN CWFA TO
ACCOUNT FOR POSSIBLE BRIEF INTENSE SNOWFALL DURING THE FRIDAY
MORNING COMMUTE. CALIBRATED SREF GUIDANCE SHOWS GREATER THAN 1 INCH
PER HOUR SNOWFALL PROBABILITIES ACROSS OUR SOUTHERN COUNTY WARNING
AREA IN THE 12-15Z TIMEFRAME FRIDAY. ALSO LATEST GRR SNOWTOOL
GUIDANCE FROM THE RAP SUGGESTS THAT 1"/HR RATES WILL BE POSSIBLE
AFTER 10Z. ADVISORY WILL BE COMING OUT SHORTLY.
AFTER THIS INITIAL BURST OF SNOWFALL...AGREE WITH THE PREVIOUS
DISCUSSION THAT IMPACTS SHOULD BE MINOR. THE RESPONSIBLE SYSTEM
CURRENTLY IN THE PLAINS WILL FILL AS IT SHEARS NORTHEAST. BEHIND THE
NARROW BUT POTENTIALLY INTENSE BAND OF WARM ADVECTION SNOW...ALL BUT
THE EXTREME NORTHERN PART OF THE FORECAST AREA DESATURATES IN THE
DGZ DURING THE LATE MORNING...MEANING A TRANSITION TO FREEZING
DRIZZLE AND THEN POSSIBLY DRIZZLE AS SURFACE TEMPERATURES WARM. ICE
ACCUMULATION IS EXPECTED TO BE MINIMAL... ESPECIALLY WITH THE
MITIGATING EFFECTS OF SNOW COVER...RESIDUAL SALT...AND DAYTIME
INSOLATION ALL DISCUSSED IN THE PREVIOUS AFD.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM EST THU FEB 21 2013
A HIGH PRESSURE RIDGE WILL PRODUCE DRY WX WITH SEASONABLY COOL
TEMPERATURES SUNDAY THROUGH SUNDAY NIGHT. LOW PRESSURE TRACKING NE
INTO OUR REGION WILL BRING A SLIGHT CHANCE FOR A MIX OF LIGHT RAIN
AND LIGHT SNOW AS EARLY AS MONDAY BASED ON 12Z GFS GUIDANCE.
HOWEVER THE MUCH BETTER CHANCE FOR MIXED PCPN SHOULD HOLD OFF UNTIL
LATE MONDAY NIGHT AND TUESDAY AS SUGGESTED BY THE SLOWER AND
PREFERRED ECMWF 12Z GUIDANCE SOLUTION (WHICH IS CONSISTENT WITH PCPN
TIMING FROM THE 00Z RUN).
TEMPS WILL UNDERGO A GRADUAL MODERATING TREND DURING THE EARLY TO
MIDDLE PORTION OF NEXT WEEK WITH MAX TEMPS EXPECTED TO REACH THE
UPPER 30S TO LOWER 40S BY TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 808 PM EST THU FEB 21 2013
CONDITIONS RANGE FROM VFR AT MOST OF THE TAF SITES THIS EVENING TO
MVFR AT KAZO. THE TREND WILL BE TOWARD LOWERING CEILINGS THROUGH
THE COURSE OF THE NIGHT WITH MVFR CONDITIONS AT LEAST AT ALL SITES
BY 10Z. A BAND OF MODERATE TO OCCASIONALLY HEAVY SNOW WILL PUSH
THROUGH THE TAF SITES BETWEEN 09Z AND 15Z...SWEEPING NORTHEAST
WITH TIME. KAZO WILL BE IMPACTED FIRST BY THE SNOW BAND AROUND
09Z. CONDITIONS WILL DIP INTO THE IFR CATEGORY AS THE BAND MOVES
THROUGH WITH THE POTENTIAL FOR VSBY/S TO DROP BELOW 1SM. CEILINGS
WILL DIP BELOW 1000FT FRIDAY MORNING...AND WILL STAY THAT WAY
THROUGH THE AFTERNOON. FREEZING DRIZZLE WILL LIKELY FOLLOW THE
SNOW ON FRIDAY AT LEAST FOR SEVERAL HOURS IN THE LATE MORNING AND
EARLY AFTERNOON. THERE IS THE POTENTIAL THAT THE FREEZING DRIZZLE
COULD LINGER MUCH OF THE DAY AS TEMPERATURES WILL ONLY RISE TO
AROUND THE FREEZING MARK IN THE AFTERNOON.
&&
.MARINE...
ISSUED AT 359 PM EST THU FEB 21 2013
AFTER FURTHER CONSIDERATION...ISSUED A NEW SMALL CRAFT ADVISORY BEGINNING
TONIGHT TO ACCOUNT FOR STRENGTHENING EAST WINDS TOWARDS MORNING. ALTHOUGH
WAVE GROWTH WILL BE LIMITED SOMEWHAT BY POOR FETCH...SUSTAINED WINDS
WELL IN EXCESS OF 20 KTS TOWARDS SUNRISE WILL GREATLY INCREASE THE
HAZARD.
&&
.HYDROLOGY...
ISSUED AT 330 PM EST THU FEB 21 2013
WITH ADDITIONAL QPF EXPECTED TO STAY WELL UNDER HALF AN INCH...THERE
ARE NO CONCERNS AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST FRIDAY FOR MIZ050-
056>059-064>067-071>074.
LM...SMALL CRAFT ADVISORY FROM 1 AM FRIDAY TO 5 PM EST SATURDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1247 AM EST WED FEB 20 2013
.UPDATE...
ISSUED AT 955 PM EST TUE FEB 19 2013
MADE SOME CHANGES TO GOING HEADLINES...MAINLY DUE TO OBSVD VEERING
TREND IN LLVL WINDS AND EXPECTED SLOW DRYING FM THE W/DIMINISHING
WINDS AS DEEP LO TO THE E SLOWLY EXITS. OPTED TO EXTEND THE WRNG FOR
MQT COUNTY AND ADVY FOR DELTA COUNTY UNTIL 16Z WED TO ACCOUNT FOR
FVRBL 340-350 DEGREE FLOW AND WINDS SUFFICIENTLY STRONG TO BLOW
HEAVIER SHSN INTO DELTA COUNTY...ALL IN THE PRESENCE OF LINGERING
DEEP MSTR. WITH A MORE N WIND...CHANGED HEADLINE FOR LUCE COUNTY FM
A WRNG TO AN ADVY DUE TO SHORTER FETCH INTO THAT AREA. MAINTAINED
GOING BLIZZARD WRNG FOR THE KEWEENAW THRU 06Z AS WINDS ARE STILL
GUSTING AOA 50 MPH AT COPPER HARBOR...BUT ISSUED WINTER WX ADVY THRU
12Z TO ACCOUNT FOR LINGERING DEEP MSTR IN THAT AREA FCST UNTIL THAT
TIME THAT MIGHT CAUSE HEAVIER SHSN EVEN AS THE WINDS/BLSN SLOWLY
SUBSIDE AFT 06Z. ALSO EXTENDED THE ADVY FOR BARAGA COUNTY TO 12Z TO
ACCOUNT FOR LINGERING DEEPER MSTR THRU THAT TIME.
PER CALL TO MI STATE POLICE AT 9 PM...M-28 WILL REMAIN CLOSED BTWN
HARVEY AND MUNISING/WETMORE THRU THE NGT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EST TUE FEB 19 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A NEG-TILT MID/UPPER LEVEL
TROUGH FROM HUDSON BAY THROUGH NW ONTARIO INTO WI/LOWER MI BEING
PROPELLED SLOWLY EAST BY A 110-120 KT 300-250 JET MOVG THROUGH THE
OHIO VALLEY TOWARD THE EASTERN LAKES IN THE BASE OF THE TROUGH.
THE BACK EDGE OF A WELL-DEFINED WARM CONVEYOR SHIELD EXTENDS BACK
INTO ERN LAKE SUPERIOR. MODERATE Q-VECT CONV COMBINED WITH NNW FLOW
ACROSS ERN LAKE SUPERIOR SUPPORTING WIND-PARALLEL LES BANDS OF
MODERATE TO HEAVY IN INTENSITY EAST OF MQT. TIGHT PRES GRADIENT ON
BACKSIDE OF 992 MB SFC LOW EAST OF LAKE SUPERIOR STILL MAINTAINING
HIGH GALE TO STORM FORCE WINDS OVER ERN HALF OF LAKE SUPERIOR.
STRONG WINDS AND MODERATE SNOW RESULTING IN BLIZZARD CONDITIONS OVER
THE KEWEENAW PENINSULA AND OVER ALGER COUNTY. STATE POLICE HAS
CLOSED M-28 BETWEEN HARVEY AND WETMORE DUE TO BLIZZARD CONDITIONS
AND IMPASSABLE ROAD CONDITIONS.
THE MODERATE 700-300 QVECTOR CONV AND DEEPER MOISTURE WILL LIFT
SLOWLY EAST WITH THE MOVEMENT OF SFC LOW TONIGHT. AS A RESULT LAKE
ENHANCED SNOW SHOWERS OVER ERN COUNTIES SHOULD SLOWLY
DIMINISH...ESPECIALLY OVERNIGHT INTO WEDNESDAY. DRIER AIR WORKING IN
OVER THE WRN PORTION OF LAKE SUPERIOR AS NOTED ON VIS SATELLITE HAS
GREATLY DIMINISHED LES OVER FAR WRN COUNTIES LATE THIS AFTERNOON.
THUS...HAVE DOWNGRADED WARNINGS TO WINTER WX ADVISORIES THIS EVENING
OVER GOGEBIC...ONTONAGON...BARAGA AND SRN HOUGHTON COUNTIES. WILL
CONTINUE BLIZZARD WARNINGS INTO THIS EVENING OVER THE KEWEENAW
PENINSULA AS WINDS GUSTING AOA 35 MPH WILL STILL CAUSE LOW
VISIBILITY AND TRAVEL DIFFICULTIES THERE. MARQUETTE COUNTY HAS SEEN
SNOW DIMINISH ACROSS MUCH OF THE AREA BUT LIGHT TO MODERATE LES
BANDS AND BLOWING SNOW...ESPECIALLY EAST OF MQT...WILL CONTINUE TO
CAUSE TRAVEL DIFFICULTIES INTO THE EVENING HRS SO KEPT WARNING GOING
FOR MQT COUNTY. CONTINUED DRYING FROM THE WEST SHOULD LEAD TO
IMPROVED CONDITIONS FOR MARQUETTE COUNTY WESTWARD LATE TONIGHT INTO
WEDNESDAY.
MOST PROLONGED HAZARDOUS CONDITIONS WILL BE FOR COUNTIES EAST OF MQT
WHERE WINDS GUSTING OVER 40 MPH AND MODERATE LES BANDS WILL
CONTINUE THE BLIZZARD TO NEAR BLIZZARD CONDITIONS THROUGH TONIGHT
AND POSSIBLY INTO WED MORNING. CONTINUED THE BLIZZARD WARNING FOR
ALGER COUNTY THROUGH MUCH OF WEDNESDAY DUE TO OCCASIONAL MODERATE
SNOW AND EXTREME BLOWING SNOW WITH STRONG NNW WINDS TO 35-40 MPH. AS
NOTED EARLIER...M-28 CLOSED BTWN HARVEY AND WETMORE DUE TO BLIZZARD
CONDITIONS. FAVORABLE SNOW GROWTH WITH DGZ WITHIN AREA OF BEST MODEL
OMEGA WILL ADD TO POOR VISIBILITY AND POTENTIAL FOR GREATER SNOWFALL
AMOUNTS TONIGHT INTO WED MORNING. MODEL AVG QPF ALONG WITH SLR FM
20-25/1 SHOULD YIELD 3-6 INCH SNOW AMOUNTS TONIGHT OVER ALGER AND
NRN SCHOOLCRAFT AND 2-5 INCHES OVER LUCE COUNTY AND SRN SCHOOLCRAFT.
DEEPER MOISTURE LEAVING THE AREA AND WEAKENING CYCLONIC NNW FLOW
WILL ALLOW LES TO GRADUALLY TAPER OFF BY WED AFTERNOON OVER ERN
COUNTIES WITH GENERALLY ADDITIONAL ACCUMS ON WED OF 2-4
INCHES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 430 PM EST TUE FEB 19 2013
COMPARED TO WHAT WAS OCCURRING OUTSIDE TODAY...THE LONG TERM IS
GENERALLY QUIET THROUGH MUCH OF THE PERIOD.
LAKE EFFECT SNOW WILL BE SLOWLY DIMINISHING ON WEDNESDAY NIGHT AS
1040MB HIGH PRESSURE OVER NORTHERN ONTARIO CONTINUES TO PUSH A
SURFACE RIDGE OVER LAKE SUPERIOR. SUBSIDENCE ALOFT FROM THIS
HIGH WILL SLOWLY DROP THE INVERSION HEIGHTS OVER THE EASTERN
LAKE FROM AROUND 4KFT AT 00Z THURSDAY TO 2KFT AT 12Z. BUT...THERE
LOOKS TO BE ENOUGH MOISTURE SUB 900MB TO LEAD TO SOME LAKE EFFECT
SNOW IN THE NORTHERLY WIND LOCATIONS OF NORTH CENTRAL UPPER
MICHIGAN. NOT OVERLY IMPRESSED WITH THE THICKNESS OF THE CLOUD
LAYER...ONLY ABOUT 1-2KFT THICK...SO THERE MIGHT NOT BE MORE THAN
VERY LIGHT SNOW OR FLURRIES LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING /MORE NORTHEAST WINDS THEN/ BEFORE THE DRIER AIR LOWERS THE
INVERSION AND SHOVES THE LINGERING CLOUDS TOWARDS THE SURFACE. AT
THAT POINT...IT WOULD LIKELY BE EITHER LOW CLOUDS OR MIX OUT FROM
DIURNAL MIXING INLAND.
THIS HIGH WILL REMAIN IN PLACE INTO THURSDAY NIGHT...AS A LOW
PRESSURE SYSTEM BEGINS TO EXIT THE CENTRAL PLAINS. MODELS NOT
SHOWING MUCH IN THE WAY OF STRENGTHENING OR WEAKENING AS THIS LOW
MOVES INTO THE GREAT LAKES ON FRIDAY AND THE UPPER GREAT LAKES ON
SATURDAY DUE TO IT BECOMING DETACHED FROM THE STRONGER SOUTHERN
STREAM JET. WITH IT PRECIPITATING ON IT/S WAY UP INTO THIS
AREA...BEING CUT OFF FROM THE GULF MOISTURE...AND RUNNING INTO DRY
AIR FROM THE CANADIAN HIGH...THE IDEA THE MODELS HAVE SHOWN FOR
SEVERAL DAYS OF THE SNOW DIMINISHING AS IT MOVES INTO THE GREAT
LAKES AREA SEEMS REASONABLE. WOULD EXPECT THE LIGHT SNOW TO MOVE
INTO THE AREA ON FRIDAY MORNING AND CONTINUE INTO THE DAY ON
SATURDAY. TOTAL QPF THROUGH THE 36 HOUR PERIOD LOOKS TO BE AROUND
0.25-0.4 INCH. ESTIMATED SNOW RATIOS AROUND 15 TO 1 AT THIS POINT
WOULD LEAD TO 4-6 INCHES OF SNOW OVER MUCH OF THE AREA DURING THAT
PERIOD. THIS WOULD LIKELY BE BELOW ADVISORY CRITERIA...ALTHOUGH SOME
LOCATIONS COULD NEAR THE 3 INCH IN 12 HOUR MARK DURING THE DAY ON
FRIDAY...ESPECIALLY TOWARDS THE WISCONSIN BORDER.
ONCE THIS SYSTEM DEPARTS TO THE EAST ON SATURDAY NIGHT...HIGH
PRESSURE AND UPPER RIDGING WILL MOVE INTO THE AREA AND LEAD TO A
QUIET AND DRY END TO THE WEEKEND AND LIKELY INTO MONDAY. 850MB TEMPS
SHOULD BE WARMER THAN -10C AND THUS WOULDN/T EXPECT ANY CONCERN FOR
LIGHT LAKE EFFECT ON SUNDAY...ESPECIALLY SINCE WINDS WILL BE BACKING
TO THE SOUTH AND PULLING WARMER AIR OVER THE AREA FOR SUNDAY NIGHT.
ATTENTION THEN TURNS TO THE NEXT WAVE EXITING THE FOUR CORNERS
REGION ON SUNDAY NIGHT AND MOVING TOWARDS THE GREAT LAKES ON MONDAY
INTO TUESDAY. AS IS TRADITIONALLY THE CASE...THE GFS IS ON THE FAST
SIDE WITH THE SYSTEM AND HAVING IT ARRIVE ON MONDAY...WHILE THE
ECMWF IS MORE TOWARDS TUESDAY/WEDNESDAY. THERE ARE ALSO DIFFERENCES
IN THE EXACT TRACK...SO WILL JUST MENTION CHANCE/SLIGHT POPS AT
THIS POINT.
AS FOR TEMPERATURES...EXPECT TO SEE A GRADUAL WARMING TREND FOR THE
SECOND HALF OF THE WORK WEEK...WITH HIGHS THIS WEEKEND AND INTO THE
FIRST PART OF NEXT WEEK AT OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1244 AM EST WED FEB 20 2013
EXPECT IFR CONDITIONS AT SAW/IWD AND LIFR CONDITIONS AT CMX EARLY
THIS MRNG TO GRADUALLY IMPROVE TO MVFR THRU THE DAY. THE ARRIVAL OF
DRIER AIR ALF AND SLOWLY DIMINISHING WINDS WL DIMINISH THE
SHSN/BLSN...BUT EXPECT LO CLDS/SOME LGT -SHSN TO LINGER WITH NLY
FLOW UNDER LOWERING INVRN BASE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST TUE FEB 19 2013
STRONG WRAPPED UP SFC LOW EAST OF LAKE SUPERIOR WILL HEAD TOWARD
WESTERN QUEBEC TONIGHT WHILE BEGINNING TO WEAKEN. VERY TIGHT
PRESSURE GRADIENT PRESENT THROUGH THIS EVENING COMBINED WITH COLD
AIR ADVECTION AND STRONG WINDS ALOFT WILL MAINTAIN STRONG GALES WITH
FREQUENT STORM FORCE GUSTS OVER THE EASTERN HALF OF LK SUPERIOR
THROUGH THIS EVENING. EXTENDED STORM WARNINGS FOR LSZ266 THROUGH
THIS EVENING. WINDS WILL BE SLOW TO DIMINISH WITH GALES PERSISTING
OVER CENTRAL AND ERN LK SUPERIOR THROUGH WED. HEAVY FREEZING SPRAY
WILL CONTINUE THROUGH THURSDAY MORNING. HIGH PRESSURE CROSSING ON
THURSDAY WILL ALLOW WINDS TO RELAX AND HEAVY FREEZING SPRAY TO
SUBSIDE. EXPECT EAST WINDS 20-30 KTS ON FRIDAY INTO FRIDAY NIGHT AS
LOW PRESSURE MOVES IN FROM THE CENTRAL PLAINS. WINDS FOR THE
UPCOMING WEEKEND NO MORE THAN 20 KTS AS WEAK PRESSURE GRADIENT
PREVAILS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WARNING UNTIL 5 PM EST THIS AFTERNOON FOR MIZ014-
085.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ001-
003.
BLIZZARD WARNING UNTIL 1 AM EST EARLY THIS MORNING FOR MIZ001-
003.
BLIZZARD WARNING UNTIL 5 PM EST THIS AFTERNOON FOR MIZ006.
WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ007.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ004.
WINTER STORM WARNING UNTIL 11 AM EST THIS MORNING FOR MIZ005.
WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR MIZ013.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY
FOR LSZ162-240>251-263-265-267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ245>251-265>267.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ264-
266.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ243-244-264.
GALE WARNING UNTIL 5 AM EST /4 AM CST/ EARLY THIS MORNING FOR
LSZ240>242-263.
LAKE MICHIGAN...
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ248-250.
&&
$$
UPDATE...KC
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...KC
MARINE...VOSS
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
342 PM CST WED FEB 20 2013
...MAJOR WINTER STORM CONTINUES ON TRACK AND WHILE WE DEAL WITH SOME
LULLS TNGT DONT LET YOUR GUARD DOWN...
ALL PRODUCTS ARE OUT AND HAVE POSTED TO THE WEB. MULTI-MEDIA WEB
BRIEFING IS BEING PUT TOGETHER.
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 239 PM CST WED FEB 20 2013
TONIGHT THROUGH EARLY FRIDAY MORNING...FOCUS CONTINUES
TO BE ON THE APPROACHING UPPER LEVEL DISTURBANCE CURRENTLY VISIBLE
IN WATER VAPOR IMAGERY CIRCULATING ACROSS CENTRAL ARIZONA. MOISTURE
AHEAD OF THIS DISTURBANCE HAS BEEN SURGING NORTHWARD FOR MUCH OF THE
DAY TODAY...WITH LIGHT SNOW SLOWLY SPREADING NORTHWARD INTO PORTIONS
OF SOUTH CENTRAL NEBRASKA THE PAST FEW HOURS. EXPECT THIS LIGHT SNOW
TO CONTINUE THROUGH THE EVENING HOURS...AND INTENSIFY SOME
OVERNIGHT. WITH THE OVERALL SLOWER AND MORE SOUTHEASTWARD TRACK OF
THIS SYSTEM...NOW EXPECT THE HEAVIEST SNOWFALL TO DEVELOP IN BANDS
ACROSS NORTH CENTRAL KANSAS DURING THE EARLY MORNING HOURS
THURSDAY...WORKING ITS WAY INTO SOUTH CENTRAL NEBRASKA BY MID
MORNING. THAT SAID...STILL EXPECT SOME SNOWFALL ACCUMULATIONS THIS
AFTERNOON AND EVENING...ESPECIALLY ACROSS THE SOUTHWESTERN SECTIONS
OF THE FORECAST AREA...WITH LIGHT SNOWFALL POSSIBLY NOT WORKING INTO
THE EASTERN FRINGES OF THE LOCAL AREA UNTIL ABOUT MIDNIGHT.
LATEST RAP CONTINUES TO BE THE MAIN OUTLIER HOLDING OFF WIDESPREAD
SNOW UNTIL AROUND DAYBREAK THURSDAY FOR MUCH OF THE EASTERN HALF OF
THE FORECAST AREA...DUE TO ITS DEPICTION OF A MORE SIGNIFICANT DRY
LAYER NEAR THE GROUND IN THE LOW LEVEL EASTERLY FLOW. HOWEVER...WITH
THE NAM/SREF/GFS/EC/WRF ALL DEVELOPING MORE WIDESPREAD PRECIPITATION
BEFORE THEN...MOSTLY DISCOUNTED RAP ANALYSIS...AND KEPT ONSET OF
PRECIPITATION SIMILAR TO THIS MORNINGS FORECAST. OTHERWISE...WHILE
THE OVERALL TIMING OF THE MAIN SYSTEM ACROSS THE DESERT SOUTHWEST
HAS SLOWED DOWN A BIT IN THE 12Z MODELS...IT STILL LOOKS TO BE A
MAJOR WINTER STORM EVENT...AND HAVE ADJUSTED FOR THE SLOWER ANALYSIS
BY EXTENDING THE WINTER STORM WARNING FOR THE NORTH/NORTHEASTERN
HALF OF THE AREA BY 6 HOURS. AND WHILE OVERALL LIQUID EQUIVALENTS
HAVE COME DOWN TO AROUND AN INCH FOR THE TRI CITIES AREA WITH THIS
SYSTEM...RANGING FROM AROUND 0.75 IN THE EC TO AROUND 1.2 IN THE
NAM...INCREASED SNOWFALL RATIOS TO BE SLIGHTLY HIGHER THAN
PREVIOUSLY THOUGHT IN THIS COLD AIRMASS...SO ONLY VERY MINOR TWEAKS
ARE EVIDENT IN THE OVERALL SNOWFALL ACCUMULATIONS.
IN ADDITION TO SNOWFALL...EXPECT BREEZY SOUTHEASTERLY WINDS TO
CONTINUE THROUGH THE EVENING AND OVERNIGHT HOURS...AS THE PRESSURE
GRADIENT BEGINS TO TIGHTEN AHEAD OF THE APPROACHING SURFACE LOW.
WINDS ARE THEN EXPECTED TO EVENTUALLY RELAX AND SHIFT MORE NORTHERLY
ON THE BACKSIDE OF THE SURFACE LOW AS IT CROSSES INTO MISSOURI AND
IOWA BY TOMORROW EVENING. HOWEVER...WITH LOTS OF FAIRLY DRY SNOW AND
BREEZY WINDS...VISIBILITIES ARE EXPECTED TO BE REDUCED IN AREAS OF
BLOWING SNOW THROUGH THE DURATION OF THIS EVENT...NOT IMPROVING TIL
AFTER 00Z...AND KEPT AREAS OF BLOWING SNOW IN THE FORECAST AS A
CONSEQUENCE.
TEMPERATURES THROUGH THIS EVENT ARE EXPECTED TO REMAIN ON THE COLD
SIDE OF CLIMATOLOGY FOR MID FEBRUARY...WITH AFTERNOON HIGHS ON
THURSDAY LIKELY NOT RISING MUCH ABOVE THE MORNING LOWS AS THE CLOUD
COVER AND SNOW WILL PUT A CAP ON HEATING ACROSS THE LOCAL AREA.
TEMPERATURES ARE THEN EXPECTED TO PLUMMET FRIDAY MORNING ON THE
BACKSIDE OF THIS SYSTEM...AS SOME CLEARING ALONG WITH RELAXING WINDS
AND FRESH SNOW COVER SHOULD ALLOW FOR GOOD RADIATIONAL COOLING BY
EARLY FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 239 PM CST WED FEB 20 2013
PATTERN: THIS IS A STORMY PATTERN AND EXCITING IF YOU/RE A WINTER WX
FAN. WE ARE LIKELY TO SEE WINTERS FURY CONTINUE FULL BORE THRU THE
END OF THE MONTH. THIS MEANS AT LEAST ONE MORE SNOW/WIND STORM AND
COLDER THAN NORMAL DAYTIME TEMPS...WITH SEVERAL DAYS OF MUCH BELOW
NORMAL /ANYTHING 33F OR BELOW/. THE -PNA/-NAO IS DICTATING THE
LONG-WAVE PATTERN WHICH FEATURES A STORMY WRN USA TROF AND
INCREASING DOWNSTREAM BLOCKING OVER ERN N AMERICA.
FOR THOSE NOT EXCITED ABOUT WINTER WX...THE PNA WILL REACH ITS
LOWEST POINT THIS WEEK AND THEN TURN POSITIVE THE 1ST WEEK OF MAR.
THE ANOMALOUS E PAC RIDGE /+2 STANDARD DEVIATION HGTS/ WILL TAKE A
BIG HIT NEXT MON-TUE FROM A DEEPENING GULF OF AK STORM. THIS WILL
INITIATE THE RETROGRESSION AND REPOSITION THE LONG-WAVE TROF FURTHER
W...INDUCING A RIDGE OVER THE WRN USA NEXT WED.
HAZARDS: THERE IS POTENTIAL FOR ANOTHER WINTER STORM SUN NGT-MON
WITH APPRECIABLE AMOUNTS OF SNOW POSSIBLE.
UPCOMING PCPN OPPORTUNITIES: 2/25.
FRI THE STORM CONTINUES TO EXIT. ANOTHER PIECE OF ENERGY MOVES
THRU SAT...ON THE BACKSIDE OF THE TROF. THE NEXT POTENT TROF DIVES
INTO THE INTERMOUNTAIN W IN THE MEANTIME...AND DEEPENS SUN-MON AS
WAVELENGTH DECREASES. ANOTHER VORT MAX FOLLOWS INTO THE DESERT SW
TUE AND THIS ODDS FAVOR THIS STORM BEING SUPPRESSED FAR TO OUR S.
THE DAILY DETAILS...
CONFIDENCE IS BELOW AVERAGE ON OUR DAYTIME HIGHS THRU THE PERIOD
SINCE MODELS STRUGGLE WITH SUBSTANTIAL SNOW-PACK ON THE GROUND. WE
MAY NOT BE COLD ENOUGH.
FRI: CLEAN-UP AND RECOVERY BUT VERY COLD WITH PLENTY OF CLOUDS. ANY
BREAKS THAT DEVELOP WILL FILL BACK IN UNDER THERMAL TROF. CANT
COMPLETELY RULE OUT A STRAY AFTN FLURRY. WINDS NOT BAD.
SAT: QUIET INTERLUDE. CONFIDENCE IS AVERAGE. WOULDNT RULE OUT SOME
FLURRIES...BUT LOW-LEVEL MSTR APPEARS LIMITED.
SAT NGT: MAINTAINED CONTINUITY WITH PREVIOUS FCST FOR A SLGT CHANCE
OF FRZG DRZL...BUT WITH LOW CONFIDENCE. INCREASING LOW-LEVEL MSTR
OVER A COLD SNOW PACK COULD RESULT IN STRATUS. DID REMOVE FLURRIES
FROM THE FCST. LOW-LEVEL THERMAL PROFILES MAY NOT BE COLD ENOUGH
FOR SNOW GRAINS.
SUN: BACKED DOWN POPS TO SLGT CHANCE.
SUN NGT-MON: THIS STORM COULD BE TROUBLE. COORDINATED WITH HPC AT
1530Z. BELIEVE THIS STORM TAKES A VERY SIMILAR TRACK TO THE CURRENT
STORM. THE DIFF IS THIS STORM IS WE/RE GETTING A SIGNAL THAT IT
LINGERS OR STALLS OVER ERN KS DURING THE DAYLIGHT HRS MON...BEFORE
SLOWLY HEADING TOWARD THE GREAT LAKES MON NGT-TUE.
ACCUMULATING/PLOWABLE SNOW REQUIRING WATCHES/WARNINGS/ADVISORIES
APPEARS LIKELY BASED ON TRENDS IN THE LAST 72 HRS. BUT THIS DOES
NOT NECESSARILY MEAN FOR OUR ENTIRE FCST AREA. POPS HAVE BEEN
INCREASED TO 60-70%. THINK WE NEED TO PREPARE FOR THE OPTION OF A
SLOW-MOVING...POSSIBLY LONG-LIVED STORM. THE BLOCKING HIGH
DOWNSTREAM URGES CAUTION.
THIS STORM HAS POTENTIAL TO BE VERY WINDY.
MODELS: 1456Z PMDEPD AND HPC GUIDANCE REVIEWED AND WE ARE IN
AGREEMENT ON A SLOWER SOLUTION PER THE EC/GEM ENSEMBLES. MOST GFS
ENSEMBLE MEMBERS LOOK TOO FAST/PROGRESSIVE AS EARLY AS 12Z/SUN. EVEN
THE HIGHER RES OPERATIONAL GFS RUNS ARE TOWARD THE SLOWER PACK.
TUE: CYCLONIC FLOW GRADUALLY RELEASES BUT STILL EXPECT PLENTY OF
CLOUDS THRU MIDDAY UNDER THERMAL TROF. BEST IMPROVEMENT S AND W OF
TRI-CITIES.
WED: QUIET AND DRY.
NAO/PNA TELECONNECTIONS: THESE REFER TO THE NORTH ATLANTIC
OSCILLATION AND PACIFIC-NORTH AMERICAN OSCILLATION. THESE
OSCILLATIONS DEAL WITH RIDGES/TROFS AND PATTERNS IN THE JET
STREAM. THE VARIOUS CONFIGURATIONS DICTATE WHAT OUR SENSIBLE
WEATHER WILL BE...ABOVE OR BELOW NORMAL TEMPS...AND DRIER OR
WETTER THAN NORMAL.
-PNA: THIS IS A TROF OVER THE WRN USA. COLDER AND STORMIER FOR THE
CNTRL PLAINS.
+PNA: THIS IS A RIDGE OVER THE WRN USA. THIS IS A QUIET AND MILD
PATTERN HERE.
THE NAO IS MOSTLY A PLAYER IN OUR STORM TRACKS HERE ON THE PLAINS.
+NAO: NO BLOCKING IN THE ATMOSPHERE NEAR GREENLAND. AT TIMES...
THIS ALLOWS COLORADO LOWS TO TRACK MORE ACROSS NEB.
-NAO: BLOCKING NEAR GREENLAND. THIS TENDS TO FORCE COLORADO LOWS
TO OUR S...ACROSS KS.
THIS WEBSITE HAS ADDITIONAL INFO...SOME OF WHICH IS TECHNICAL.
CHECK OUT THE MAPS THAT INDICATE INDICATE THE POSITIVE PHASES.
WARM COLORS INDICATE WARMER TEMPS AND DECREASED STORMINESS. COLD
COLORS INDICATE COLDER TEMPS AND INCREASED STORMINESS. FOR THE
NEGATIVE PHASES...JUST REVERSE THE COLORS. THESE TELECONNECTIONS
HAVE THE GREATEST IMPACTS IN THE COOLER MONTHS OF THE YEAR.
WWW.CPC.NCEP.NOAA.GOV/DATA/TELEDOC/TELEINTRO.SHTML (ALL LOWER CASE)
&&
.AVIATION...18Z KGRI TAF...DETERIORATING CONDITIONS ARE EXPECTED
AT KGRI OVER THE NEXT 24 HOURS AS AN APPROACHING STORM SYSTEM
SPREADS ITS INFLUENCE NORTHWARD. EXPECT VFR CIGS TO LOWER AND
VSBYS TO BECOME MVFR AS LIGHT SNOW REACHES THE TERMINAL AROUND
20Z. WHILE CIGS AND VSBYS WILL REMAIN GENERALLY MVFR THROUGH THE
OVERNIGHT HOURS...A MORE SIGNIFICANT DEGRADATION IN CONDITIONS IS
NOT EXPECTED UNTIL THE MORE MODERATE TO HEAVY SNOW BANDS REACH THE
TERMINAL DURING THE MORNING HOURS THURSDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER STORM WARNING FROM 6 PM THIS EVENING TO MIDNIGHT CST
THURSDAY NIGHT FOR NEZ039>041-046>049-061>064-074>077-
085>087.
WINTER STORM WARNING UNTIL MIDNIGHT CST THURSDAY NIGHT FOR
NEZ060-072-073.
WINTER STORM WARNING UNTIL 6 PM CST THURSDAY FOR NEZ082>084.
KS...WINTER STORM WARNING UNTIL 6 PM CST THURSDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...ROSSI
LONG TERM...HALBLAUB
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
337 PM CST WED FEB 20 2013
...MAJOR WINTER STORM CONTINUES ON TRACK AND WHILE WE DEAL WITH SOME
LULLS THIS TNGT DONT LET YOUR GUARD DOWN...
ALL PRODUCTS ARE OUT AND HAVE POSTED TO THE WEB. MULTI-MEDIA WEB
BRIEFING IS BEING PUT TOGETHER.
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 239 PM CST WED FEB 20 2013
TONIGHT THROUGH EARLY FRIDAY MORNING...FOCUS CONTINUES
TO BE ON THE APPROACHING UPPER LEVEL DISTURBANCE CURRENTLY VISIBLE
IN WATER VAPOR IMAGERY CIRCULATING ACROSS CENTRAL ARIZONA. MOISTURE
AHEAD OF THIS DISTURBANCE HAS BEEN SURGING NORTHWARD FOR MUCH OF THE
DAY TODAY...WITH LIGHT SNOW SLOWLY SPREADING NORTHWARD INTO PORTIONS
OF SOUTH CENTRAL NEBRASKA THE PAST FEW HOURS. EXPECT THIS LIGHT SNOW
TO CONTINUE THROUGH THE EVENING HOURS...AND INTENSIFY SOME
OVERNIGHT. WITH THE OVERALL SLOWER AND MORE SOUTHEASTWARD TRACK OF
THIS SYSTEM...NOW EXPECT THE HEAVIEST SNOWFALL TO DEVELOP IN BANDS
ACROSS NORTH CENTRAL KANSAS DURING THE EARLY MORNING HOURS
THURSDAY...WORKING ITS WAY INTO SOUTH CENTRAL NEBRASKA BY MID
MORNING. THAT SAID...STILL EXPECT SOME SNOWFALL ACCUMULATIONS THIS
AFTERNOON AND EVENING...ESPECIALLY ACROSS THE SOUTHWESTERN SECTIONS
OF THE FORECAST AREA...WITH LIGHT SNOWFALL POSSIBLY NOT WORKING INTO
THE EASTERN FRINGES OF THE LOCAL AREA UNTIL ABOUT MIDNIGHT.
LATEST RAP CONTINUES TO BE THE MAIN OUTLIER HOLDING OFF WIDESPREAD
SNOW UNTIL AROUND DAYBREAK THURSDAY FOR MUCH OF THE EASTERN HALF OF
THE FORECAST AREA...DUE TO ITS DEPICTION OF A MORE SIGNIFICANT DRY
LAYER NEAR THE GROUND IN THE LOW LEVEL EASTERLY FLOW. HOWEVER...WITH
THE NAM/SREF/GFS/EC/WRF ALL DEVELOPING MORE WIDESPREAD PRECIPITATION
BEFORE THEN...MOSTLY DISCOUNTED RAP ANALYSIS...AND KEPT ONSET OF
PRECIPITATION SIMILAR TO THIS MORNINGS FORECAST. OTHERWISE...WHILE
THE OVERALL TIMING OF THE MAIN SYSTEM ACROSS THE DESERT SOUTHWEST
HAS SLOWED DOWN A BIT IN THE 12Z MODELS...IT STILL LOOKS TO BE A
MAJOR WINTER STORM EVENT...AND HAVE ADJUSTED FOR THE SLOWER ANALYSIS
BY EXTENDING THE WINTER STORM WARNING FOR THE NORTH/NORTHEASTERN
HALF OF THE AREA BY 6 HOURS. AND WHILE OVERALL LIQUID EQUIVALENTS
HAVE COME DOWN TO AROUND AN INCH FOR THE TRI CITIES AREA WITH THIS
SYSTEM...RANGING FROM AROUND 0.75 IN THE EC TO AROUND 1.2 IN THE
NAM...INCREASED SNOWFALL RATIOS TO BE SLIGHTLY HIGHER THAN
PREVIOUSLY THOUGHT IN THIS COLD AIRMASS...SO ONLY VERY MINOR TWEAKS
ARE EVIDENT IN THE OVERALL SNOWFALL ACCUMULATIONS.
IN ADDITION TO SNOWFALL...EXPECT BREEZY SOUTHEASTERLY WINDS TO
CONTINUE THROUGH THE EVENING AND OVERNIGHT HOURS...AS THE PRESSURE
GRADIENT BEGINS TO TIGHTEN AHEAD OF THE APPROACHING SURFACE LOW.
WINDS ARE THEN EXPECTED TO EVENTUALLY RELAX AND SHIFT MORE NORTHERLY
ON THE BACKSIDE OF THE SURFACE LOW AS IT CROSSES INTO MISSOURI AND
IOWA BY TOMORROW EVENING. HOWEVER...WITH LOTS OF FAIRLY DRY SNOW AND
BREEZY WINDS...VISIBILITIES ARE EXPECTED TO BE REDUCED IN AREAS OF
BLOWING SNOW THROUGH THE DURATION OF THIS EVENT...NOT IMPROVING TIL
AFTER 00Z...AND KEPT AREAS OF BLOWING SNOW IN THE FORECAST AS A
CONSEQUENCE.
TEMPERATURES THROUGH THIS EVENT ARE EXPECTED TO REMAIN ON THE COLD
SIDE OF CLIMATOLOGY FOR MID FEBRUARY...WITH AFTERNOON HIGHS ON
THURSDAY LIKELY NOT RISING MUCH ABOVE THE MORNING LOWS AS THE CLOUD
COVER AND SNOW WILL PUT A CAP ON HEATING ACROSS THE LOCAL AREA.
TEMPERATURES ARE THEN EXPECTED TO PLUMMET FRIDAY MORNING ON THE
BACKSIDE OF THIS SYSTEM...AS SOME CLEARING ALONG WITH RELAXING WINDS
AND FRESH SNOW COVER SHOULD ALLOW FOR GOOD RADIATIONAL COOLING BY
EARLY FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 239 PM CST WED FEB 20 2013
PATTERN: THIS IS A STORMY PATTERN AND EXCITING IF YOU/RE A WINTER WX
FAN. WE ARE LIKELY TO SEE WINTERS FURY CONTINUE FULL BORE THRU THE
END OF THE MONTH. THIS MEANS AT LEAST ONE MORE SNOW/WIND STORM AND
COLDER THAN NORMAL DAYTIME TEMPS...WITH SEVERAL DAYS OF MUCH BELOW
NORMAL /ANYTHING 33F OR BELOW/. THE -PNA/-NAO IS DICTATING THE
LONG-WAVE PATTERN WHICH FEATURES A STORMY WRN USA TROF AND
INCREASING DOWNSTREAM BLOCKING OVER ERN N AMERICA.
FOR THOSE NOT EXCITED ABOUT WINTER WX...THE PNA WILL REACH ITS
LOWEST POINT THIS WEEK AND THEN TURN POSITIVE THE 1ST WEEK OF MAR.
THE ANOMALOUS E PAC RIDGE /+2 STANDARD DEVIATION HGTS/ WILL TAKE A
BIG HIT NEXT MON-TUE FROM A DEEPENING GULF OF AK STORM. THIS WILL
INITIATE THE RETROGRESSION AND REPOSITION THE LONG-WAVE TROF FURTHER
W...INDUCING A RIDGE OVER THE WRN USA NEXT WED.
HAZARDS: THERE IS POTENTIAL FOR ANOTHER WINTER STORM SUN NGT-MON
WITH APPRECIABLE AMOUNTS OF SNOW POSSIBLE.
UPCOMING PCPN OPPORTUNITIES: 2/25.
FRI THE STORM CONTINUES TO EXIT. ANOTHER PIECE OF ENERGY MOVES
THRU SAT...ON THE BACKSIDE OF THE TROF. THE NEXT POTENT TROF DIVES
INTO THE INTERMOUNTAIN W IN THE MEANTIME...AND DEEPENS SUN-MON AS
WAVELENGTH DECREASES. ANOTHER VORT MAX FOLLOWS INTO THE DESERT SW
TUE AND THIS ODDS FAVOR THIS STORM BEING SUPPRESSED FAR TO OUR S.
THE DAILY DETAILS...
CONFIDENCE IS BELOW AVERAGE ON OUR DAYTIME HIGHS THRU THE PERIOD
SINCE MODELS STRUGGLE WITH SUBSTANTIAL SNOW-PACK ON THE GROUND. WE
MAY NOT BE COLD ENOUGH.
FRI: CLEAN-UP AND RECOVERY BUT VERY COLD WITH PLENTY OF CLOUDS. ANY
BREAKS THAT DEVELOP WILL FILL BACK IN UNDER THERMAL TROF. CANT
COMPLETELY RULE OUT A STRAY AFTN FLURRY. WINDS NOT BAD.
SAT: QUIET INTERLUDE. CONFIDENCE IS AVERAGE. WOULDNT RULE OUT SOME
FLURRIES...BUT LOW-LEVEL MSTR APPEARS LIMITED.
SAT NGT: MAINTAINED CONTINUITY WITH PREVIOUS FCST FOR A SLGT CHANCE
OF FRZG DRZL...BUT WITH LOW CONFIDENCE. INCREASING LOW-LEVEL MSTR
OVER A COLD SNOW PACK COULD RESULT IN STRATUS. DID REMOVE FLURRIES
FROM THE FCST. LOW-LEVEL THERMAL PROFILES MAY NOT BE COLD ENOUGH
FOR SNOW GRAINS.
SUN: BACKED DOWN POPS TO SLGT CHANCE.
SUN NGT-MON: THIS STORM COULD BE TROUBLE. COORDINATED WITH HPC AT
1530Z. BELIEVE THIS STORM TAKES A VERY SIMILAR TRACK TO THE CURRENT
STORM. THE DIFF IS THIS STORM IS WE/RE GETTING A SIGNAL THAT IT
LINGERS OR STALLS OVER ERN KS DURING THE DAYLIGHT HRS MON...BEFORE
SLOWLY HEADING TOWARD THE GREAT LAKES MON NGT-TUE.
ACCUMULATING/PLOWABLE SNOW REQUIRING WATCHES/WARNINGS/ADVISORIES
APPEARS LIKELY BASED ON TRENDS IN THE LAST 72 HRS. BUT THIS DOES
NOT NECESSARILY MEAN FOR OUR ENTIRE FCST AREA. POPS HAVE BEEN
INCREASED TO 60-70%. THINK WE NEED TO PREPARE FOR THE OPTION OF A
SLOW-MOVING...POSSIBLY LONG-LIVED STORM. THE BLOCKING HIGH
DOWNSTREAM URGES CAUTION.
THIS STORM HAS POTENTIAL TO BE VERY WINDY.
MODELS: 1456Z PMDEPD AND HPC GUIDANCE REVIEWED AND WE ARE IN
AGREEMENT ON A SLOWER SOLUTION PER THE EC/GEM ENSEMBLES. MOST GFS
ENSEMBLE MEMBERS LOOK TOO FAST/PROGRESSIVE AS EARLY AS 12Z/SUN. EVEN
THE HIGHER RES OPERATIONAL GFS RUNS ARE TOWARD THE SLOWER PACK.
TUE: CYCLONIC FLOW GRADUALLY RELEASES BUT STILL EXPECT PLENTY OF
CLOUDS THRU MIDDAY UNDER THERMAL TROF. BEST IMPROVEMENT S AND W OF
TRI-CITIES.
WED: QUIET AND DRY.
NAO/PNA TELECONNECTIONS: THESE REFER TO THE NORTH ATLANTIC
OSCILLATION AND PACIFIC-NORTH AMERICAN OSCILLATION. THESE
OSCILLATIONS DEAL WITH RIDGES/TROFS AND PATTERNS IN THE JET
STREAM. THE VARIOUS CONFIGURATIONS DICTATE WHAT OUR SENSIBLE
WEATHER WILL BE...ABOVE OR BELOW NORMAL TEMPS...AND DRIER OR
WETTER THAN NORMAL.
-PNA: THIS IS A TROF OVER THE WRN USA. COLDER AND STORMIER FOR THE
CNTRL PLAINS.
+PNA: THIS IS A RIDGE OVER THE WRN USA. THIS IS A QUIET AND MILD
PATTERN HERE.
THE NAO IS MOSTLY A PLAYER IN OUR STORM TRACKS HERE ON THE PLAINS.
+NAO: NO BLOCKING IN THE ATMOSPHERE NEAR GREENLAND. AT TIMES...
THIS ALLOWS COLORADO LOWS TO TRACK MORE ACROSS NEB.
-NAO: BLOCKING NEAR GREENLAND. THIS TENDS TO FORCE COLORADO LOWS
TO OUR S...ACROSS KS.
THIS WEBSITE HAS ADDITIONAL INFO...SOME OF WHICH IS TECHNICAL.
CHECK OUT THE MAPS THAT INDICATE INDICATE THE POSITIVE PHASES.
WARM COLORS INDICATE WARMER TEMPS AND DECREASED STORMINESS. COLD
COLORS INDICATE COLDER TEMPS AND INCREASED STORMINESS. FOR THE
NEGATIVE PHASES...JUST REVERSE THE COLORS. THESE TELECONNECTIONS
HAVE THE GREATEST IMPACTS IN THE COOLER MONTHS OF THE YEAR.
WWW.CPC.NCEP.NOAA.GOV/DATA/TELEDOC/TELEINTRO.SHTML (ALL LOWER CASE)
&&
.AVIATION...18Z KGRI TAF...DETERIORATING CONDITIONS ARE EXPECTED
AT KGRI OVER THE NEXT 24 HOURS AS AN APPROACHING STORM SYSTEM
SPREADS ITS INFLUENCE NORTHWARD. EXPECT VFR CIGS TO LOWER AND
VSBYS TO BECOME MVFR AS LIGHT SNOW REACHES THE TERMINAL AROUND
20Z. WHILE CIGS AND VSBYS WILL REMAIN GENERALLY MVFR THROUGH THE
OVERNIGHT HOURS...A MORE SIGNIFICANT DEGRADATION IN CONDITIONS IS
NOT EXPECTED UNTIL THE MORE MODERATE TO HEAVY SNOW BANDS REACH THE
TERMINAL DURING THE MORNING HOURS THURSDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER STORM WARNING FROM 6 PM THIS EVENING TO MIDNIGHT CST
THURSDAY NIGHT FOR NEZ039>041-046>049-061>064-074>077-
085>087.
WINTER STORM WARNING UNTIL MIDNIGHT CST THURSDAY NIGHT FOR
NEZ060-072-073.
WINTER STORM WARNING UNTIL 6 PM CST THURSDAY FOR NEZ082>084.
KS...WINTER STORM WARNING UNTIL 6 PM CST THURSDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...ROSSI
LONG TERM...HALBLAUB
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1148 AM CST WED FEB 20 2013
.AVIATION...18Z KGRI TAF...DETERIORATING CONDITIONS ARE EXPECTED
AT KGRI OVER THE NEXT 24 HOURS AS AN APPROACHING STORM SYSTEM
SPREADS ITS INFLUENCE NORTHWARD. EXPECT VFR CIGS TO LOWER AND
VSBYS TO BECOME MVFR AS LIGHT SNOW REACHES THE TERMINAL AROUND
20Z. WHILE CIGS AND VSBYS WILL REMAIN GENERALLY MVFR THROUGH THE
OVERNIGHT HOURS...A MORE SIGNIFICANT DEGRADATION IN CONDITIONS IS
NOT EXPECTED UNTIL THE MORE MODERATE TO HEAVY SNOW BANDS REACH THE
TERMINAL DURING THE MORNING HOURS THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 413 AM CST WED FEB 20 2013/
SHORT TERM...TODAY THROUGH FRIDAY NIGHT. MAIN SHOW IN THE SHORT
TERM REMAINS WITH THE WINTER STORM MOVING INTO/THROUGH THE PLAINS
TODAY THROUGH THURSDAY.
SEEING THE QUIET BEFORE THE STORM EARLY THIS MORNING...WITH UPPER
AIR PROFILER AND SATELLITE DATA SHOWING SOUTHWESTERLY FLOW
CURRENTLY IN PLACE ACROSS THE REGION. THE MAIN UPPER LEVEL LOW
IS SPINNING OVER THE SRN COAST OF CALIFORNIA...WHILE A WEAKER
DISTURBANCE OUT AHEAD IS MOVING ONTO THE SOUTHERN PLAINS. AT THE
SURFACE...THE CWA IS SITTING WITH EASTERLY WINDS...BETWEEN LOW
PRESSURE OVER THE CENTRAL/SRN ROCKIES AND A RIDGE OF HIGH PRESSURE
EXTENDING FROM CENTRAL CANADA ALONG THE MO RIVER.
LOOKING AT THE DAYTIME HOURS TODAY...THE MAIN STORM SYSTEM WILL
CONTINUE IS EASTWARD TREK...AND IS EXPECTED TO BE OVER ERN
PORTIONS OF AZ BY THIS EVENING. THE PRIMARY PLAYER FOR THE CWA
TODAY WILL BE THAT WEAKER DISTURBANCE OUT AHEAD OF THE
SYSTEM...WHICH IS EXPECTED TO SLIDE NORTH INTO THE AREA. WHILE NO
MAJOR CHANGES WERE MADE TO THE FORECAST...ONE THING OF NOTE IS
THAT THE LATEST MODEL RUNS HAVE COME IN SLIGHTLY FURTHER SOUTH AND
SLOWER WITH THE SYSTEM. THIS IS ALSO TRUE WITH THIS FIRST
DISTURBANCE...WITH PRECIP GRADUALLY CREEPING IN FROM THE SOUTH
THROUGH THE DAYTIME HOURS. ADJUSTMENTS MADE TO THE POPS WERE TO
SLOW THEM A BIT AND TAPER BACK THE EASTERN EDGE...AS THE IMPACT OF
THE DRIER AIR/LOWER DEW POINTS BEING PUSHED IN VIA THOSE EASTERLY
WINDS IS GOING TO MAKE IT MORE DIFFICULT FOR THINGS TO SATURATE
AND GET PRECIP TO THE GROUND.
THIS EVENING/OVERNIGHT...THE SYSTEM SHIFTS ACROSS THE
ROCKIES...AND LOOKS TO BE NEAR THE TX PANHANDLE BY 12Z THURSDAY.
DECIDED TO LEAVE THE HEADLINES AS IS WITH THE 00Z START TIME FOR
CENTRAL/ERN AREAS...THOUGH SERIOUSLY CONSIDERED PUSHING BACK THE
TIME FOR SOME OF THOSE FAR EASTERN COUNTIES...WHERE IT MAY BE
CLOSER TO 03-06Z BEFORE PRECIP CAN REALLY MOVE IN. BUT BECAUSE NOT
ALL MODELS ARE KEEPING THINGS COMPLETELY DRY...AND IT WOULD ONLY
BE A CHANGE OF A COUPLE HOURS FOR JUST A FEW COUNTIES...KEPT IT AS
IS.
WHILE PRECIPITATION WILL GOING ON THROUGH THE OVERNIGHT HOURS...IT
REALLY ISNT THE MAIN SHOW...INTENSITY/COVERAGE IS GOING TO BE MORE
VARIABLE WITH THE SYSTEM COMING IN A TOUCH SLOWER. CURRENT MODEL
RUNS SHOWING THE MORE WIDESPREAD HEAVIER SNOWFALL LOOKS TO MAKING
ITS MAIN PUSH INTO OUR NC KS COUNTIES ARND 12Z THURSDAY...AND THEN
SHIFTING NORTH THROUGH THE DAY AS THE SYSTEM SLIDES NORTHEAST
NEAR/JUST OUTSIDE THE SOUTHEAST CORNER OF THE CWA. MODELS
CERTAINLY KEEPING THIS SYSTEM MORE VERTICALLY STACKED ALONG ITS
PATH THROUGH THE PLAINS THAN A FEW DAYS AGO. MADE ADDITIONAL BUMPS
UP IN POPS DURING THE THURSDAY AFTERNOON/EVENING HOURS WITH THINGS
MOVING OUT A BIT SLOWER...WILL KEEP THE END TIME FOR THE HEADLINES
AS THINGS SHOULD BE ON THE DOWNWARD TREND...BUT THOSE EASTERN
AREAS MAY ULTIMATELY END UP HAVING TO HANG ONTO IT A FEW HOURS
LONGER. WILL HOW THE TIMING WORKS OUT.
DIDNT MAKE ANY NOTABLE CHANGES TO THE WINDS...WHICH WILL REMAIN
EASTERLY THROUGH THE MAJORITY OF THIS EVENING AS THE SURFACE LOW
MOVES ONTO/THROUGH THE SRN PLAINS...AND AS WE GET INTO THURSDAY
AFTERNOON/EVENING...THE SURFACE LOW EVENTUALLY STARTS PUSHING FAR
ENOUGH EAST THAT WE GET A MORE NORTHERLY COMPONENT TO THE WINDS.
WITH THE LOW PASSING SO FAR TO THE SOUTH OF THE CWA...MAINLY
ACROSS OK...IT WILL HELP SURFACE WINDS FROM GETTING
EXTRAORDINARILY HIGH. STILL LOOKING AT SUSTAINED SPEEDS GENERALLY
IN THE 15 TO 25 MPH RANGE...WITH GUSTS OF 30 TO 35 MPH AT TIMES.
AS FAR AS STORM TOTAL SNOWFALL ACCUMULATIONS GO...OVERALL THERE
REALLY WAS NO SIGNIFICANT CHANGES MADE. AS FAR AS THE VARIATION
ACROSS THE CWA GOES...BETWEEN THE SLOWER ONSET/NEEDING TO OVERCOME
THE DRIER AIR EARLY ON IN THE EVENT ACROSS THE FAR NRN/NERN
FRINGES OF THE CWA...THAT AREA IS LOOKING TO SEE THE LOWER
TOTALS...WHICH MATCHES UP WELL WITH LATEST HPC GUIDANCE...BUT WE
ARE STILL TALKING ARND 10 INCHES POSSIBLE. THE AREA OF HIGHEST
SNOWFALL ACCUMULATIONS STILL TARGETING THE SRN/SWRN PORTIONS OF
THE CWA...WHERE TOTALS STILL EXPECTED TO BE PUSHING 16 INCHES.
WILL HAVE TO KEEP A CLOSE EYE ON HOW THIS FIRST WAVE OF
PRECIPITATION TODAY PANS OUT...IF THE DRIER AIR ENDS UP HAVING A
LARGER IMPACT /LIKE WHAT THE RAP IS HINTING AT/...SOME OF THOSE
TOTALS IN THE EAST WOULD BE AFFECTED.
LONG TERM...SATURDAY THROUGH TUESDAY.
BIGGEST CHALLENGE WILL BE THE POSSIBILITY OF PRECIPITATION MAINLY
SATURDAY NIGHT INTO MONDAY NIGHT.
WE BEGIN THE LONG TERM IN THE MIDST OF A VERY ACTIVE PATTERN.
PROGRESSIVE FLOW WILL BRING A QUICK MOVING SHORTWAVE RIDGE INTO
THE AREA FROM THE WEST FOR SATURDAY...PROVIDING A SHORT LULL IN
ACTIVITY. THE RIDGE AXIS WILL MOVE SWIFTLY EAST OF THE CWA
SATURDAY NIGHT WITH WARM AIR ADVECTION ENSUING...PROBABLY GIVING
US AN EARLY LOW TEMPERATURE...POSSIBLY STEADY OR RISING IN THE 20S
DURING THE OVERNIGHT HOURS.
OUT AHEAD OF ANOTHER APPROACHING WINTER SYSTEM...THE GFS PAINTS
SOME VERY LIGHT QPF OVER THE CWA FOR SATURDAY NIGHT. SOUNDINGS
INDICATE THAT THIS COULD VERY WELL BE FREEZING DRIZZLE WITH A
PRONOUNCED MID-LEVEL DRY LAYER AND AN INVERTED TEMPERATURE PROFILE
AND SATURATED LOWER BOUNDARY LAYER ON FORECAST SOUNDINGS FROM THE
GFS. IF SNOW SUBLIMATES THE DRY LAYER...THEN WE COULD POSSIBLY
LOSE THE DRY LAYER BY THE END OF THE NIGHT AND EARLY SATURDAY TO
MAKE IT ALL FLURRIES. A WARM LAYER ASSOCIATED WITH THE DRY AIR
WOULD NORMALLY BE ALARMING...BUT BY THE TIME WE COULD GET ANYTHING
MORE THAN FREEZING DRIZZLE OR FLURRIES...THIS LAYER WILL HAVE
COOLED DOWN...AND WE SHOULD GET PRIMARILY SNOW FOR MOST OF SUNDAY
INTO MONDAY NIGHT.
THE WINTER SYSTEM MOVING OUT OF THE ROCKIES SUNDAY INTO MONDAY HAS
A FORECAST TRACK THAT IS SIMILAR TO THE ONE GIVING US SOME
COPIOUS SNOW FOR TONIGHT THROUGH THURSDAY NIGHT. MODELS ARE NOT
QUITE AS CONSISTENT AND IN AGREEMENT WITH THE SYSTEM COMING IN
SUNDAY/MONDAY...BUT NONETHELESS ARE CONSISTENT ENOUGH TO PUT
RATHER HEALTHY CHANCE PROBABILITY OF PRECIPITATION. SYNOPTIC LIFT
TAKES AN UPSWING ON SUNDAY BUT REALLY MAXES OUT ON SUNDAY
NIGHT...WITH STRONG LIFT INDICATED...AND WANING LIFT ON MONDAY.
WIND LOOKS QUITE BRISK ON THE BACKSIDE OF THE SURFACE LOW AS IT IS
FORECAST TO TRACK ACROSS THE SOUTHERN CWA ON SUNDAY. FOR SUNDAY
NIGHT INTO MONDAY...HAVE RAISED WIND SPEEDS...ESPECIALLY WEST AND
CENTRAL CWA ACCORDINGLY. THIS COULD GIVE US AREAS OF BLOWING SNOW
FOR CENTRAL/WESTERN AREAS AND HAVE INCLUDED THIS IN THE FORECAST
AND EXPECT SOME HEALTHY COLD AIR ADVECTION.
STILL WENT ON THE COOL SIDE FOR TEMPERATURES...ESPECIALLY HIGH
TEMPERATURES AS SNOW COVER WILL BE SOLID AND I STILL DO NOT THINK
MID/LONG RANGE MODELS HAVE A FULL GRASP ON THIS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST THURSDAY
FOR NEZ039>041-046>049-061>064-074>077-085>087.
WINTER STORM WARNING UNTIL 6 PM CST THURSDAY FOR NEZ060-072-073-
082>084.
KS...WINTER STORM WARNING UNTIL 6 PM CST THURSDAY FOR KSZ005>007-
017>019.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
522 AM CST WED FEB 20 2013
.AVIATION...AVIATION...06Z KGRI TAF. GENERALLY LOWERING CEILINGS AND
INCREASING WIND SPEEDS AS A SIGNIFICANT WINTER STORM DRAWS NEAR.
LIGHT SNOW WILL PROBABLY START SOMETIME IN THE LATE AFTERNOON WITH
CEILING AND VISIBILITY CONTINUING TO GO DOWNHILL INTO THE EVENING
INTO THE OVERNIGHT HOURS. SNOW COULD START TO GET HEAVY DURING THE
LAST COUPLE OF HOURS OF THIS FORECAST...BUT MORE LIKELY WILL WAIT
UNTIL THURSDAY MORNING TO BECOME HEAVY.
&&
.PREV DISCUSSION... /ISSUED 413 AM CST WED FEB 20 2013/
SHORT TERM...TODAY THROUGH FRIDAY NIGHT. MAIN SHOW IN THE SHORT
TERM REMAINS WITH THE WINTER STORM MOVING INTO/THROUGH THE PLAINS
TODAY THROUGH THURSDAY.
SEEING THE QUIET BEFORE THE STORM EARLY THIS MORNING...WITH UPPER
AIR PROFILER AND SATELLITE DATA SHOWING SOUTHWESTERLY FLOW
CURRENTLY IN PLACE ACROSS THE REGION. THE MAIN UPPER LEVEL LOW
IS SPINNING OVER THE SRN COAST OF CALIFORNIA...WHILE A WEAKER
DISTURBANCE OUT AHEAD IS MOVING ONTO THE SOUTHERN PLAINS. AT THE
SURFACE...THE CWA IS SITTING WITH EASTERLY WINDS...BETWEEN LOW
PRESSURE OVER THE CENTRAL/SRN ROCKIES AND A RIDGE OF HIGH PRESSURE
EXTENDING FROM CENTRAL CANADA ALONG THE MO RIVER.
LOOKING AT THE DAYTIME HOURS TODAY...THE MAIN STORM SYSTEM WILL
CONTINUE IS EASTWARD TREK...AND IS EXPECTED TO BE OVER ERN
PORTIONS OF AZ BY THIS EVENING. THE PRIMARY PLAYER FOR THE CWA
TODAY WILL BE THAT WEAKER DISTURBANCE OUT AHEAD OF THE
SYSTEM...WHICH IS EXPECTED TO SLIDE NORTH INTO THE AREA. WHILE NO
MAJOR CHANGES WERE MADE TO THE FORECAST...ONE THING OF NOTE IS
THAT THE LATEST MODEL RUNS HAVE COME IN SLIGHTLY FURTHER SOUTH AND
SLOWER WITH THE SYSTEM. THIS IS ALSO TRUE WITH THIS FIRST
DISTURBANCE...WITH PRECIP GRADUALLY CREEPING IN FROM THE SOUTH
THROUGH THE DAYTIME HOURS. ADJUSTMENTS MADE TO THE POPS WERE TO
SLOW THEM A BIT AND TAPER BACK THE EASTERN EDGE...AS THE IMPACT OF
THE DRIER AIR/LOWER DEW POINTS BEING PUSHED IN VIA THOSE EASTERLY
WINDS IS GOING TO MAKE IT MORE DIFFICULT FOR THINGS TO SATURATE
AND GET PRECIP TO THE GROUND.
THIS EVENING/OVERNIGHT...THE SYSTEM SHIFTS ACROSS THE
ROCKIES...AND LOOKS TO BE NEAR THE TX PANHANDLE BY 12Z THURSDAY.
DECIDED TO LEAVE THE HEADLINES AS IS WITH THE 00Z START TIME FOR
CENTRAL/ERN AREAS...THOUGH SERIOUSLY CONSIDERED PUSHING BACK THE
TIME FOR SOME OF THOSE FAR EASTERN COUNTIES...WHERE IT MAY BE
CLOSER TO 03-06Z BEFORE PRECIP CAN REALLY MOVE IN. BUT BECAUSE NOT
ALL MODELS ARE KEEPING THINGS COMPLETELY DRY...AND IT WOULD ONLY
BE A CHANGE OF A COUPLE HOURS FOR JUST A FEW COUNTIES...KEPT IT AS
IS.
WHILE PRECIPITATION WILL GOING ON THROUGH THE OVERNIGHT HOURS...IT
REALLY ISNT THE MAIN SHOW...INTENSITY/COVERAGE IS GOING TO BE MORE
VARIABLE WITH THE SYSTEM COMING IN A TOUCH SLOWER. CURRENT MODEL
RUNS SHOWING THE MORE WIDESPREAD HEAVIER SNOWFALL LOOKS TO MAKING
ITS MAIN PUSH INTO OUR NC KS COUNTIES ARND 12Z THURSDAY...AND THEN
SHIFTING NORTH THROUGH THE DAY AS THE SYSTEM SLIDES NORTHEAST
NEAR/JUST OUTSIDE THE SOUTHEAST CORNER OF THE CWA. MODELS
CERTAINLY KEEPING THIS SYSTEM MORE VERTICALLY STACKED ALONG ITS
PATH THROUGH THE PLAINS THAN A FEW DAYS AGO. MADE ADDITIONAL BUMPS
UP IN POPS DURING THE THURSDAY AFTERNOON/EVENING HOURS WITH THINGS
MOVING OUT A BIT SLOWER...WILL KEEP THE END TIME FOR THE HEADLINES
AS THINGS SHOULD BE ON THE DOWNWARD TREND...BUT THOSE EASTERN
AREAS MAY ULTIMATELY END UP HAVING TO HANG ONTO IT A FEW HOURS
LONGER. WILL HOW THE TIMING WORKS OUT.
DIDNT MAKE ANY NOTABLE CHANGES TO THE WINDS...WHICH WILL REMAIN
EASTERLY THROUGH THE MAJORITY OF THIS EVENING AS THE SURFACE LOW
MOVES ONTO/THROUGH THE SRN PLAINS...AND AS WE GET INTO THURSDAY
AFTERNOON/EVENING...THE SURFACE LOW EVENTUALLY STARTS PUSHING FAR
ENOUGH EAST THAT WE GET A MORE NORTHERLY COMPONENT TO THE WINDS.
WITH THE LOW PASSING SO FAR TO THE SOUTH OF THE CWA...MAINLY
ACROSS OK...IT WILL HELP SURFACE WINDS FROM GETTING
EXTRAORDINARILY HIGH. STILL LOOKING AT SUSTAINED SPEEDS GENERALLY
IN THE 15 TO 25 MPH RANGE...WITH GUSTS OF 30 TO 35 MPH AT TIMES.
AS FAR AS STORM TOTAL SNOWFALL ACCUMULATIONS GO...OVERALL THERE
REALLY WAS NO SIGNIFICANT CHANGES MADE. AS FAR AS THE VARIATION
ACROSS THE CWA GOES...BETWEEN THE SLOWER ONSET/NEEDING TO OVERCOME
THE DRIER AIR EARLY ON IN THE EVENT ACROSS THE FAR NRN/NERN
FRINGES OF THE CWA...THAT AREA IS LOOKING TO SEE THE LOWER
TOTALS...WHICH MATCHES UP WELL WITH LATEST HPC GUIDANCE...BUT WE
ARE STILL TALKING ARND 10 INCHES POSSIBLE. THE AREA OF HIGHEST
SNOWFALL ACCUMULATIONS STILL TARGETING THE SRN/SWRN PORTIONS OF
THE CWA...WHERE TOTALS STILL EXPECTED TO BE PUSHING 16 INCHES.
WILL HAVE TO KEEP A CLOSE EYE ON HOW THIS FIRST WAVE OF
PRECIPITATION TODAY PANS OUT...IF THE DRIER AIR ENDS UP HAVING A
LARGER IMPACT /LIKE WHAT THE RAP IS HINTING AT/...SOME OF THOSE
TOTALS IN THE EAST WOULD BE AFFECTED.
LONG TERM...SATURDAY THROUGH TUESDAY.
BIGGEST CHALLENGE WILL BE THE POSSIBILITY OF PRECIPITATION MAINLY
SATURDAY NIGHT INTO MONDAY NIGHT.
WE BEGIN THE LONG TERM IN THE MIDST OF A VERY ACTIVE PATTERN.
PROGRESSIVE FLOW WILL BRING A QUICK MOVING SHORTWAVE RIDGE INTO
THE AREA FROM THE WEST FOR SATURDAY...PROVIDING A SHORT LULL IN
ACTIVITY. THE RIDGE AXIS WILL MOVE SWIFTLY EAST OF THE CWA
SATURDAY NIGHT WITH WARM AIR ADVECTION ENSUING...PROBABLY GIVING
US AN EARLY LOW TEMPERATURE...POSSIBLY STEADY OR RISING IN THE 20S
DURING THE OVERNIGHT HOURS.
OUT AHEAD OF ANOTHER APPROACHING WINTER SYSTEM...THE GFS PAINTS
SOME VERY LIGHT QPF OVER THE CWA FOR SATURDAY NIGHT. SOUNDINGS
INDICATE THAT THIS COULD VERY WELL BE FREEZING DRIZZLE WITH A
PRONOUNCED MID-LEVEL DRY LAYER AND AN INVERTED TEMPERATURE PROFILE
AND SATURATED LOWER BOUNDARY LAYER ON FORECAST SOUNDINGS FROM THE
GFS. IF SNOW SUBLIMATES THE DRY LAYER...THEN WE COULD POSSIBLY
LOSE THE DRY LAYER BY THE END OF THE NIGHT AND EARLY SATURDAY TO
MAKE IT ALL FLURRIES. A WARM LAYER ASSOCIATED WITH THE DRY AIR
WOULD NORMALLY BE ALARMING...BUT BY THE TIME WE COULD GET ANYTHING
MORE THAN FREEZING DRIZZLE OR FLURRIES...THIS LAYER WILL HAVE
COOLED DOWN...AND WE SHOULD GET PRIMARILY SNOW FOR MOST OF SUNDAY
INTO MONDAY NIGHT.
THE WINTER SYSTEM MOVING OUT OF THE ROCKIES SUNDAY INTO MONDAY HAS
A FORECAST TRACK THAT IS SIMILAR TO THE ONE GIVING US SOME
COPIOUS SNOW FOR TONIGHT THROUGH THURSDAY NIGHT. MODELS ARE NOT
QUITE AS CONSISTENT AND IN AGREEMENT WITH THE SYSTEM COMING IN
SUNDAY/MONDAY...BUT NONETHELESS ARE CONSISTENT ENOUGH TO PUT
RATHER HEALTHY CHANCE PROBABILITY OF PRECIPITATION. SYNOPTIC LIFT
TAKES AN UPSWING ON SUNDAY BUT REALLY MAXES OUT ON SUNDAY
NIGHT...WITH STRONG LIFT INDICATED...AND WANING LIFT ON MONDAY.
WIND LOOKS QUITE BRISK ON THE BACKSIDE OF THE SURFACE LOW AS IT IS
FORECAST TO TRACK ACROSS THE SOUTHERN CWA ON SUNDAY. FOR SUNDAY
NIGHT INTO MONDAY...HAVE RAISED WIND SPEEDS...ESPECIALLY WEST AND
CENTRAL CWA ACCORDINGLY. THIS COULD GIVE US AREAS OF BLOWING SNOW
FOR CENTRAL/WESTERN AREAS AND HAVE INCLUDED THIS IN THE FORECAST
AND EXPECT SOME HEALTHY COLD AIR ADVECTION.
STILL WENT ON THE COOL SIDE FOR TEMPERATURES...ESPECIALLY HIGH
TEMPERATURES AS SNOW COVER WILL BE SOLID AND I STILL DO NOT THINK
MID/LONG RANGE MODELS HAVE A FULL GRASP ON THIS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST THURSDAY
FOR NEZ039>041-046>049-061>064-074>077-085>087.
WINTER STORM WARNING FROM NOON TODAY TO 6 PM CST THURSDAY FOR
NEZ060-072-073-082>084.
KS...WINTER STORM WARNING FROM NOON TODAY TO 6 PM CST THURSDAY FOR
KSZ005>007-017>019.
&&
$$
SHORT TERM...ADO
LONG TERM/AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
413 AM CST WED FEB 20 2013
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT. MAIN SHOW IN THE SHORT
TERM REMAINS WITH THE WINTER STORM MOVING INTO/THROUGH THE PLAINS
TODAY THROUGH THURSDAY.
SEEING THE QUIET BEFORE THE STORM EARLY THIS MORNING...WITH UPPER
AIR PROFILER AND SATELLITE DATA SHOWING SOUTHWESTERLY FLOW
CURRENTLY IN PLACE ACROSS THE REGION. THE MAIN UPPER LEVEL LOW
IS SPINNING OVER THE SRN COAST OF CALIFORNIA...WHILE A WEAKER
DISTURBANCE OUT AHEAD IS MOVING ONTO THE SOUTHERN PLAINS. AT THE
SURFACE...THE CWA IS SITTING WITH EASTERLY WINDS...BETWEEN LOW
PRESSURE OVER THE CENTRAL/SRN ROCKIES AND A RIDGE OF HIGH PRESSURE
EXTENDING FROM CENTRAL CANADA ALONG THE MO RIVER.
LOOKING AT THE DAYTIME HOURS TODAY...THE MAIN STORM SYSTEM WILL
CONTINUE IS EASTWARD TREK...AND IS EXPECTED TO BE OVER ERN
PORTIONS OF AZ BY THIS EVENING. THE PRIMARY PLAYER FOR THE CWA
TODAY WILL BE THAT WEAKER DISTURBANCE OUT AHEAD OF THE
SYSTEM...WHICH IS EXPECTED TO SLIDE NORTH INTO THE AREA. WHILE NO
MAJOR CHANGES WERE MADE TO THE FORECAST...ONE THING OF NOTE IS
THAT THE LATEST MODEL RUNS HAVE COME IN SLIGHTLY FURTHER SOUTH AND
SLOWER WITH THE SYSTEM. THIS IS ALSO TRUE WITH THIS FIRST
DISTURBANCE...WITH PRECIP GRADUALLY CREEPING IN FROM THE SOUTH
THROUGH THE DAYTIME HOURS. ADJUSTMENTS MADE TO THE POPS WERE TO
SLOW THEM A BIT AND TAPER BACK THE EASTERN EDGE...AS THE IMPACT OF
THE DRIER AIR/LOWER DEW POINTS BEING PUSHED IN VIA THOSE EASTERLY
WINDS IS GOING TO MAKE IT MORE DIFFICULT FOR THINGS TO SATURATE
AND GET PRECIP TO THE GROUND.
THIS EVENING/OVERNIGHT...THE SYSTEM SHIFTS ACROSS THE
ROCKIES...AND LOOKS TO BE NEAR THE TX PANHANDLE BY 12Z THURSDAY.
DECIDED TO LEAVE THE HEADLINES AS IS WITH THE 00Z START TIME FOR
CENTRAL/ERN AREAS...THOUGH SERIOUSLY CONSIDERED PUSHING BACK THE
TIME FOR SOME OF THOSE FAR EASTERN COUNTIES...WHERE IT MAY BE
CLOSER TO 03-06Z BEFORE PRECIP CAN REALLY MOVE IN. BUT BECAUSE NOT
ALL MODELS ARE KEEPING THINGS COMPLETELY DRY...AND IT WOULD ONLY
BE A CHANGE OF A COUPLE HOURS FOR JUST A FEW COUNTIES...KEPT IT AS
IS.
WHILE PRECIPITATION WILL GOING ON THROUGH THE OVERNIGHT HOURS...IT
REALLY ISNT THE MAIN SHOW...INTENSITY/COVERAGE IS GOING TO BE MORE
VARIABLE WITH THE SYSTEM COMING IN A TOUCH SLOWER. CURRENT MODEL
RUNS SHOWING THE MORE WIDESPREAD HEAVIER SNOWFALL LOOKS TO MAKING
ITS MAIN PUSH INTO OUR NC KS COUNTIES ARND 12Z THURSDAY...AND THEN
SHIFTING NORTH THROUGH THE DAY AS THE SYSTEM SLIDES NORTHEAST
NEAR/JUST OUTSIDE THE SOUTHEAST CORNER OF THE CWA. MODELS
CERTAINLY KEEPING THIS SYSTEM MORE VERTICALLY STACKED ALONG ITS
PATH THROUGH THE PLAINS THAN A FEW DAYS AGO. MADE ADDITIONAL BUMPS
UP IN POPS DURING THE THURSDAY AFTERNOON/EVENING HOURS WITH THINGS
MOVING OUT A BIT SLOWER...WILL KEEP THE END TIME FOR THE HEADLINES
AS THINGS SHOULD BE ON THE DOWNWARD TREND...BUT THOSE EASTERN
AREAS MAY ULTIMATELY END UP HAVING TO HANG ONTO IT A FEW HOURS
LONGER. WILL HOW THE TIMING WORKS OUT.
DIDNT MAKE ANY NOTABLE CHANGES TO THE WINDS...WHICH WILL REMAIN
EASTERLY THROUGH THE MAJORITY OF THIS EVENING AS THE SURFACE LOW
MOVES ONTO/THROUGH THE SRN PLAINS...AND AS WE GET INTO THURSDAY
AFTERNOON/EVENING...THE SURFACE LOW EVENTUALLY STARTS PUSHING FAR
ENOUGH EAST THAT WE GET A MORE NORTHERLY COMPONENT TO THE WINDS.
WITH THE LOW PASSING SO FAR TO THE SOUTH OF THE CWA...MAINLY
ACROSS OK...IT WILL HELP SURFACE WINDS FROM GETTING
EXTRAORDINARILY HIGH. STILL LOOKING AT SUSTAINED SPEEDS GENERALLY
IN THE 15 TO 25 MPH RANGE...WITH GUSTS OF 30 TO 35 MPH AT TIMES.
AS FAR AS STORM TOTAL SNOWFALL ACCUMULATIONS GO...OVERALL THERE
REALLY WAS NO SIGNIFICANT CHANGES MADE. AS FAR AS THE VARIATION
ACROSS THE CWA GOES...BETWEEN THE SLOWER ONSET/NEEDING TO OVERCOME
THE DRIER AIR EARLY ON IN THE EVENT ACROSS THE FAR NRN/NERN
FRINGES OF THE CWA...THAT AREA IS LOOKING TO SEE THE LOWER
TOTALS...WHICH MATCHES UP WELL WITH LATEST HPC GUIDANCE...BUT WE
ARE STILL TALKING ARND 10 INCHES POSSIBLE. THE AREA OF HIGHEST
SNOWFALL ACCUMULATIONS STILL TARGETING THE SRN/SWRN PORTIONS OF
THE CWA...WHERE TOTALS STILL EXPECTED TO BE PUSHING 16 INCHES.
WILL HAVE TO KEEP A CLOSE EYE ON HOW THIS FIRST WAVE OF
PRECIPITATION TODAY PANS OUT...IF THE DRIER AIR ENDS UP HAVING A
LARGER IMPACT /LIKE WHAT THE RAP IS HINTING AT/...SOME OF THOSE
TOTALS IN THE EAST WOULD BE AFFECTED.
.LONG TERM...SATURDAY THROUGH TUESDAY.
BIGGEST CHALLENGE WILL BE THE POSSIBILITY OF PRECIPITATION MAINLY
SATURDAY NIGHT INTO MONDAY NIGHT.
WE BEGIN THE LONG TERM IN THE MIDST OF A VERY ACTIVE PATTERN.
PROGRESSIVE FLOW WILL BRING A QUICK MOVING SHORTWAVE RIDGE INTO
THE AREA FROM THE WEST FOR SATURDAY...PROVIDING A SHORT LULL IN
ACTIVITY. THE RIDGE AXIS WILL MOVE SWIFTLY EAST OF THE CWA
SATURDAY NIGHT WITH WARM AIR ADVECTION ENSUING...PROBABLY GIVING
US AN EARLY LOW TEMPERATURE...POSSIBLY STEADY OR RISING IN THE 20S
DURING THE OVERNIGHT HOURS.
OUT AHEAD OF ANOTHER APPROACHING WINTER SYSTEM...THE GFS PAINTS
SOME VERY LIGHT QPF OVER THE CWA FOR SATURDAY NIGHT. SOUNDINGS
INDICATE THAT THIS COULD VERY WELL BE FREEZING DRIZZLE WITH A
PRONOUNCED MID-LEVEL DRY LAYER AND AN INVERTED TEMPERATURE PROFILE
AND SATURATED LOWER BOUNDARY LAYER ON FORECAST SOUNDINGS FROM THE
GFS. IF SNOW SUBLIMATES THE DRY LAYER...THEN WE COULD POSSIBLY
LOSE THE DRY LAYER BY THE END OF THE NIGHT AND EARLY SATURDAY TO
MAKE IT ALL FLURRIES. A WARM LAYER ASSOCIATED WITH THE DRY AIR
WOULD NORMALLY BE ALARMING...BUT BY THE TIME WE COULD GET ANYTHING
MORE THAN FREEZING DRIZZLE OR FLURRIES...THIS LAYER WILL HAVE
COOLED DOWN...AND WE SHOULD GET PRIMARILY SNOW FOR MOST OF SUNDAY
INTO MONDAY NIGHT.
THE WINTER SYSTEM MOVING OUT OF THE ROCKIES SUNDAY INTO MONDAY HAS
A FORECAST TRACK THAT IS SIMILAR TO THE ONE GIVING US SOME
COPIOUS SNOW FOR TONIGHT THROUGH THURSDAY NIGHT. MODELS ARE NOT
QUITE AS CONSISTENT AND IN AGREEMENT WITH THE SYSTEM COMING IN
SUNDAY/MONDAY...BUT NONETHELESS ARE CONSISTENT ENOUGH TO PUT
RATHER HEALTHY CHANCE PROBABILITY OF PRECIPITATION. SYNOPTIC LIFT
TAKES AN UPSWING ON SUNDAY BUT REALLY MAXES OUT ON SUNDAY
NIGHT...WITH STRONG LIFT INDICATED...AND WANING LIFT ON MONDAY.
WIND LOOKS QUITE BRISK ON THE BACKSIDE OF THE SURFACE LOW AS IT IS
FORECAST TO TRACK ACROSS THE SOUTHERN CWA ON SUNDAY. FOR SUNDAY
NIGHT INTO MONDAY...HAVE RAISED WIND SPEEDS...ESPECIALLY WEST AND
CENTRAL CWA ACCORDINGLY. THIS COULD GIVE US AREAS OF BLOWING SNOW
FOR CENTRAL/WESTERN AREAS AND HAVE INCLUDED THIS IN THE FORECAST
AND EXPECT SOME HEALTHY COLD AIR ADVECTION.
STILL WENT ON THE COOL SIDE FOR TEMPERATURES...ESPECIALLY HIGH
TEMPERATURES AS SNOW COVER WILL BE SOLID AND I STILL DO NOT THINK
MID/LONG RANGE MODELS HAVE A FULL GRASP ON THIS.
&&
.AVIATION...06Z KGRI TAF. GENERALLY LOWERING CEILINGS AND
INCREASING WIND SPEEDS AS A SIGNIFICANT WINTER STORM DRAWS NEAR.
LIGHT SNOW WILL PROBABLY START SOMETIME IN THE MID TO LATE
AFTERNOON WITH CEILING AND VISIBILITY CONTINUING TO GO DOWNHILL
INTO THE EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST THURSDAY
FOR NEZ039>041-046>049-061>064-074>077-085>087.
WINTER STORM WARNING FROM NOON TODAY TO 6 PM CST THURSDAY FOR
NEZ060-072-073-082>084.
KS...WINTER STORM WARNING FROM NOON TODAY TO 6 PM CST THURSDAY FOR
KSZ005>007-017>019.
&&
$$
SHORT TERM...ADO
LONG TERM/AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1053 PM MST TUE FEB 19 2013
.AVIATION...
06Z TAF CYCLE
UPPER LOW ALONG CENTRAL CA COAST AT 05Z WILL CONTINUE TO TRACK
SOUTH THROUGH CA AND BE CENTERED NEAR KBLH AROUND 20/18Z. AHEAD OF
THE LOW...SOUTHWEST FLOW ACCOMPANIED BY A STREAM OF SUBTROPICAL
MOISTURE AS WELL AS A WEAK DISTURBANCE STRETCHED OVER EASTERN AZ SETTING
OFF ISOLD TO SCATTERED SHOWERS AND PSBLY ISOLD TSRA. MTS MAY BE
OCNLY OBSCURED THROUGH 15Z IN THIS ACTIVITY AND MVFR CIGS AS BNDRY
LAYER MOISTURE INCREASES. SOUTH TO SOUTHEAST SURFACE WINDS GUSTING
TO AROUND 25 TO POSSIBLY 35KT WILL BE WIDESPREAD OVER CENTRAL AND
EASTERN NM...AND A GUSTY SOUTHEAST WIND MAY IMPACT KSAF AND KABQ
BETWEEN 20/06Z AND 20/12Z.
&&
.PREV DISCUSSION...946 PM MST TUE FEB 19 2013...
RAISING DEWPOINTS AND TEMPERATURES OVERNIGHT IN THE RIO GRANDE
VALLEY. ADDING DE BACA AND CHAVES ZONES TO THE WIND ADVISORY
FOR WED INTO WED NIGHT. NO CHANGES TO THE WSW. ZONES AND NPW
OUT SHORTLY. WSW ALREADY SENT. CHJ
&&
.PREV DISCUSSION...321 PM MST TUE FEB 19 2013... LAST TWO HOURS
OF SURFACE OBS AND THE CIRA DERIVED PWAT VALUES SHOW SOME OF THE
STRONGEST MOISTURE ADVECTION THIS FORECASTER HAS SEEN IN A LONG
TIME. DEWPOINT VALUES ACROSS SOUTHERN NM ROSE FROM THE SINGLE
DIGITS INTO THE 30S AND LOW 40S BTWN 15Z AND 21Z. SOUTH TO
SOUTHWEST FLOW USHERING IN THIS MOISTURE WILL SPREAD ACROSS NM
TONIGHT...THUS OVERNIGHT LOWS WILL BE SIGNIFICANTLY WARMER THAN
THE PAST SEVERAL. 12Z/18Z BUFKIT PROFILES AND LATEST RUC SOLUTION
SHOWING BIG TIME TOP DOWN MOISTENING THIS EVENING LEADING TO A LOW
CLOUD LAYER WITH LIGHT RAIN SHOWERS AND DRIZZLE ACROSS MUCH OF THE
EAST. HAVE RAISED POPS IN THIS AREA CONSIDERABLY. THIS DEEP SURGE
OF LOW LEVEL MOISTURE IS IN RESPONSE TO A DEEPER 534DM H5 LOW OVER
CENTRAL CALIFORNIA DIGGING CONTINUOUSLY FARTHER SOUTH EACH
RUN...THUS BACKING LOW LEVEL WIND FIELDS MORE EFFICIENTLY.
WITH THIS TRACK AND DEEPER MOISTURE HAVE ESSENTIALLY INCREASED POPS
ALL AREAS. ACCORDINGLY THE 700-500MB LAYER WIND FIELDS HAVE SHIFTED
MORE INTO SOUTHERN NM INCREASING CONFIDENCE THAT HIGH WIND SPEEDS
WILL NOT IMPACT OUR REGION. THE SUITE OF HI RES MODEL SOLUTIONS AND
THE FOCUS FOR DYNAMICS ON THE LATEST MODEL SOLUTIONS HAVE INCREASED
CONFIDENCE ENOUGH TO UPGRADE THE WINTER STORM WATCH TO A WARNING FOR
ALL MT ZONES AND CONVERT TO ADVISORY FOR A FEW OTHERS. ALSO ADDED
THE SANGRE DE CRISTO MTS TO THE WARNING. THE MAIN IMPACT PERIOD FOR
MOIST UPSLOPE COLD ADVECTIVE WESTERLY FLOW WILL BE WEDNESDAY NIGHT
INTO THURSDAY...SO THAT SEGMENT WILL BE VALID FOR SLIGHTLY LONGER.
TEMPS WILL TAKE A NOSE DIVE WEDNESDAY AFTERNOON FROM WEST TO EAST...
WITH A FEW AREAS OUT WEST SEEING HIGHS IN THE MORNING.
WE SHOULD NOT FORGOT THAT MOIST INSTABILITY ALONG THE PACIFIC COLD
FRONTAL BNDRY WILL BE SUFFICIENT TO GENERATE A LINE OF STORMS OVER
THE FAR EASTERN PLAINS LATE WEDNESDAY AFT. BLOWING DUST WILL BE AN
ISSUE BEHIND THIS FRONT FOR THE PECOS AND LOWER RIO GRANDE VALLEY
AREAS. DID REMOVE MOST OF THE BLOWING SNOW WORDING FOR THE NORTH
AND WEST AS AGAIN THE WINDS APPEAR STRONGEST MUCH FARTHER SOUTH.
A SECONDARY WAVE WILL SLIDE OVER THE AREA THURSDAY/FRIDAY WITH WEAK
FORCING AND SLIGHTLY MORE COLD ADVECTION. THIS FEATURE WILL FOCUS
THE ACTION MAINLY ON THE HIGHER TERRAIN WHERE MOISTURE FROM THE
FIRST SYSTEM IS SQUEEZED OUT. A BRIEF BREAK WILL SLIDE OVER LATE
FRIDAY/SATURDAY...BEFORE ANOTHER WIND BAG ARRIVES SUNDAY. MODELS
JUST KEEP IT COMING NEXT WEEK WITH ANOTHER POTENTIAL STORM TUESDAY.
GUYER
&&
.FIRE WEATHER...
A STRING OF WEATHER SYSTEMS WILL CROSS THE FORECAST AREA WEDNESDAY
THROUGH MONDAY. THERE WILL BE SOME FIRE WEATHER CONCERNS EAST OF THE
CENTRAL MOUNTAINS SATURDAY...MONDAY AND ESPECIALLY SUNDAY.
THE FIRST STORM IN THE SERIES WILL PROBABLY PRODUCE THE MOST
PRECIPITATION AND THE STRONGEST WINDS. MODELS KEEP NUDGING THIS
SYSTEM FURTHER SOUTH WITH EACH RUN...AND THE LOW PRESSURE CENTER IS
NOW EXPECTED TO PASS EASTWARD FROM QUEMADO TO TUCUMCARI WEDNESDAY
THROUGH WEDNESDAY NIGHT. THE POTENTIAL EXISTS FOR SEVERAL INCHES OF
SNOW BY THURSDAY MORNING ACROSS THE NORTHERN AND WESTERN
MOUNTAINS...WITH A FEW INCHES TO POSSIBLY A HALF FOOT AT LOWER
ELEVATIONS OF THE WEST CENTRAL AND NORTHWEST PLATEAU AND LIGHTER
AMOUNTS IN THE UPPER RIO GRANDE VALLEY. FARTHER SOUTH AND EAST THE
MAIN WEATHER CONCERN WILL BE WIND. THE POLAR JET STREAM WILL CROSS
SOUTHERN NM ON WEDNESDAY...THEN A STRONG SURFACE LOW IN THE LEE OF
THE SOUTHERN CO ROCKIES WILL KEEP THE PRESSURE GRADIENT TIGHT AND
WINDS STRONG ACROSS EASTERN NM WEDNESDAY NIGHT THROUGH THURSDAY.
GUSTS UP TO 50 MPH ARE EXPECTED FROM AROUND SOCORRO TO AROUND GRAN
QUIVIRA DURING EARLY AFTERNOON WEDNESDAY...THEN THESE STRONG WINDS
SHOULD SPREAD NORTHEASTWARD ALONG THE EAST SLOPES OF THE CENTRAL AND
SOUTHERN SANGRE DE CRISTO MOUNTAINS DURING THE LATE AFTERNOON AND
NIGHT. A COLD FRONT WILL ALSO CROSS FROM THE WEST WEDNESDAY AND
WEDNESDAY NIGHT...WITH MECHANICAL MIXING HELPING TO KEEP WINDS GOING
THROUGH THE NIGHT IN THE EAST.
IN THE WAKE OF THE COLD FRONT...HIGH TEMPERATURES THURSDAY WILL FALL
A FEW TO 8 DEGREES BELOW WEDNESDAYS READINGS. THE SURFACE PRESSURE
GRADIENT WILL REMAIN TIGHT IN THE EAST. WIND GUSTS TO 50 MPH ARE
EXPECTED TO CONTINUE FROM CLINES CORNERS TO SUMNER LAKE UNTIL SUNSET
THURSDAY EVENING. JUST AS THE FIRST UPPER LOW EXITS THURSDAY
MORNING...A TRAILING UPPER TROUGH WILL DIVE SOUTHEASTWARD THROUGH
THE FORECAST AREA THURSDAY AFTERNOON THROUGH FRIDAY. THIS WILL CAUSE
SNOW SHOWERS TO LINGER...BUT THIS SYSTEM WILL BE SIGNIFICANTLY
DRIER. THERE MAY BE A FEW INCHES OF ADDITIONAL SNOW ACCUMULATION IN
THE NORTHERN AND POSSIBLY THE WESTERN MOUNTAINS. HIGH TEMPERATURES
THURSDAY AND FRIDAY WILL VARY FROM 5 TO 20 DEGREES BELOW NORMAL.
THE AREA WILL BE BETWEEN STORM SYSTEMS SATURDAY. WEAK RIDGING WILL
PRODUCE TEMPERATURES 8 TO 15 DEGREES WARMER THAN FRIDAYS READINGS.
WEST WINDS WILL BECOME BREEZY TO WINDY AGAIN IN THE LEE OF THE
CENTRAL MOUNTAINS DUE TO A STRONG SURFACE LEE TROUGH AND
STRENGTHENING WINDS ALOFT AHEAD OF THE NEXT WEATHER SYSTEM. POCKETS
OF MINIMUM HUMIDITIES IN THE LOWER TEENS SHOULD RESULT IN AN HOUR OR
TWO OF CRITICAL FIRE WEATHER CONDITIONS ON THE EAST CENTRAL PLAINS.
A MORE CRITICAL FIRE WEATHER PATTERN MAY DEVELOP FOR NM SUNDAY AS AN
UPPER TROUGH STRENGTHENS INTO A CLOSED UPPER LOW WHILE PASSING
EASTWARD OVER CO AND/OR NORTHERN NM. THIS WILL STEER A STRONG POLAR
JET STREAK OVER THE SOUTHERN ROCKIES WHILE DRIVING A COLD FRONT
SOUTHWARD THROUGH NM. NW WIND GUSTS MAY PEAK AROUND 50 MPH FROM THE
SANDIA AND MANZANO MOUNTAINS EASTWARD ONTO THE EAST CENTRAL PLAINS.
MUCH OF THIS AREA MAY EXPERIENCE SEVERAL HOURS OF CRITICAL FIRE
WEATHER CONDITIONS. MODELS DISAGREE ON HOW FAR SOUTH THE UPPER LOW
WILL CROSS. IF IT DROPS AS FAR SOUTH AS NORTHERN NM...THEN THE
NORTHERN AND WESTERN MOUNTAINS COULD RECEIVE A FEW TO SEVERAL
ADDITIONAL INCHES OF SNOW BY MONDAY MORNING. MONDAY SHOULD SEE HIGH
TEMPERATURES ROUGHLY 6 TO 16 DEGREES BELOW NORMAL. AFTER AN EXTENDED
PERIOD OF GOOD TO EXCELLENT VENTILATION...MAX VENT RATES MONDAY MAY
NOT GET OUT OF THE POOR CATEGORY IN MANY LOWER ELEVATION
LOCATIONS.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM WEDNESDAY TO MIDNIGHT MST WEDNESDAY NIGHT
FOR THE FOLLOWING ZONES...NMZ520-524>526-537>540.
WINTER STORM WARNING FROM 6 AM WEDNESDAY TO 6 AM MST THURSDAY FOR
THE FOLLOWING ZONES...NMZ502>506-508>511.
WINTER STORM WARNING FROM 6 AM WEDNESDAY TO NOON MST THURSDAY FOR
THE FOLLOWING ZONES...NMZ512>514.
WINTER WEATHER ADVISORY FROM 6 AM WEDNESDAY TO 6 AM MST THURSDAY
FOR THE FOLLOWING ZONES...NMZ501-507-516.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
946 PM MST TUE FEB 19 2013
.UPDATE...
RAISING DEWPOINTS AND TEMPERATURES OVERNIGHT IN THE RIO GRANDE
VALLEY. ADDING DE BACA AND CHAVES ZONES TO THE WIND ADVISORY
FOR WED INTO WED NIGHT. NO CHANGES TO THE WSW. ZONES AND NPW
OUT SHORTLY. WSW ALREADY SENT. CHJ
.PREV DISCUSSION...457 PM MST TUE FEB 19 2013...
.AVIATION...
00Z TAF CYCLE
UPPER LOW VCNTY KSFO AT 23Z WILL CONTINUE TO TRACK SOUTH THROUGH
CA AND BE CENTERED NEAR KBLH AROUND 20/18Z. AHEAD OF THE
LOW...SOUTHWEST FLOW ACCOMPANIED BY A STREAM OF SUBTROPICAL
MOISTURE SETTING OFF ISOLD TO SCATTERED SHOWERS AND PSBLY ISOLD
TSRA FROM THE KEPZ AREA NORTHEAST TO PSBLY AS FAR NORTHEAST AS
KTCC. MTS MAY BE BRIEFLY OBSCURED IN THIS ACTIVITY. SOUTH TO
SOUTHEAST SURFACE WINDS GUSTING TO AROUND 35KT WILL BE WIDESPREAD
OVER THIS REGION...AND A GUSTY SOUTHEAST WIND MAY IMPACT KSAF AND
KABQ BEFORE 20/12Z. LOCALLY REDUCED VSBYS IN BD MAY BE FOUND ALONG
AND SOUTH OF A LINE FROM THE GILA MTS NORTHEAST TO KCAO.
321 PM MST TUE FEB 19 2013...
LAST TWO HOURS OF SURFACE OBS AND THE CIRA DERIVED PWAT VALUES
SHOW SOME OF THE STRONGEST MOISTURE ADVECTION THIS FORECASTER HAS
SEEN IN A LONG TIME. DEWPOINT VALUES ACROSS SOUTHERN NM ROSE FROM
THE SINGLE DIGITS INTO THE 30S AND LOW 40S BTWN 15Z AND 21Z. SOUTH
TO SOUTHWEST FLOW USHERING IN THIS MOISTURE WILL SPREAD ACROSS NM
TONIGHT...THUS OVERNIGHT LOWS WILL BE SIGNIFICANTLY WARMER THAN
THE PAST SEVERAL. 12Z/18Z BUFKIT PROFILES AND LATEST RUC SOLUTION
SHOWING BIG TIME TOP DOWN MOISTENING THIS EVENING LEADING TO A LOW
CLOUD LAYER WITH LIGHT RAIN SHOWERS AND DRIZZLE ACROSS MUCH OF THE
EAST. HAVE RAISED POPS IN THIS AREA CONSIDERABLY. THIS DEEP SURGE
OF LOW LEVEL MOISTURE IS IN RESPONSE TO A DEEPER 534DM H5 LOW OVER
CENTRAL CALIFORNIA DIGGING CONTINUOUSLY FARTHER SOUTH EACH
RUN...THUS BACKING LOW LEVEL WIND FIELDS MORE EFFICIENTLY.
WITH THIS TRACK AND DEEPER MOISTURE HAVE ESSENTIALLY INCREASED POPS
ALL AREAS. ACCORDINGLY THE 700-500MB LAYER WIND FIELDS HAVE SHIFTED
MORE INTO SOUTHERN NM INCREASING CONFIDENCE THAT HIGH WIND SPEEDS
WILL NOT IMPACT OUR REGION. THE SUITE OF HI RES MODEL SOLUTIONS AND
THE FOCUS FOR DYNAMICS ON THE LATEST MODEL SOLUTIONS HAVE INCREASED
CONFIDENCE ENOUGH TO UPGRADE THE WINTER STORM WATCH TO A WARNING FOR
ALL MT ZONES AND CONVERT TO ADVISORY FOR A FEW OTHERS. ALSO ADDED
THE SANGRE DE CRISTO MTS TO THE WARNING. THE MAIN IMPACT PERIOD FOR
MOIST UPSLOPE COLD ADVECTIVE WESTERLY FLOW WILL BE WEDNESDAY NIGHT
INTO THURSDAY...SO THAT SEGMENT WILL BE VALID FOR SLIGHTLY LONGER.
TEMPS WILL TAKE A NOSE DIVE WEDNESDAY AFTERNOON FROM WEST TO EAST...
WITH A FEW AREAS OUT WEST SEEING HIGHS IN THE MORNING.
WE SHOULD NOT FORGOT THAT MOIST INSTABILITY ALONG THE PACIFIC COLD
FRONTAL BNDRY WILL BE SUFFICIENT TO GENERATE A LINE OF STORMS OVER
THE FAR EASTERN PLAINS LATE WEDNESDAY AFT. BLOWING DUST WILL BE AN
ISSUE BEHIND THIS FRONT FOR THE PECOS AND LOWER RIO GRANDE VALLEY
AREAS. DID REMOVE MOST OF THE BLOWING SNOW WORDING FOR THE NORTH
AND WEST AS AGAIN THE WINDS APPEAR STRONGEST MUCH FARTHER SOUTH.
A SECONDARY WAVE WILL SLIDE OVER THE AREA THURSDAY/FRIDAY WITH WEAK
FORCING AND SLIGHTLY MORE COLD ADVECTION. THIS FEATURE WILL FOCUS
THE ACTION MAINLY ON THE HIGHER TERRAIN WHERE MOISTURE FROM THE
FIRST SYSTEM IS SQUEEZED OUT. A BRIEF BREAK WILL SLIDE OVER LATE
FRIDAY/SATURDAY...BEFORE ANOTHER WIND BAG ARRIVES SUNDAY. MODELS
JUST KEEP IT COMING NEXT WEEK WITH ANOTHER POTENTIAL STORM TUESDAY.
GUYER
.FIRE WEATHER...
A STRING OF WEATHER SYSTEMS WILL CROSS THE FORECAST AREA WEDNESDAY
THROUGH MONDAY. THERE WILL BE SOME FIRE WEATHER CONCERNS EAST OF THE
CENTRAL MOUNTAINS SATURDAY...MONDAY AND ESPECIALLY SUNDAY.
THE FIRST STORM IN THE SERIES WILL PROBABLY PRODUCE THE MOST
PRECIPITATION AND THE STRONGEST WINDS. MODELS KEEP NUDGING THIS
SYSTEM FURTHER SOUTH WITH EACH RUN...AND THE LOW PRESSURE CENTER IS
NOW EXPECTED TO PASS EASTWARD FROM QUEMADO TO TUCUMCARI WEDNESDAY
THROUGH WEDNESDAY NIGHT. THE POTENTIAL EXISTS FOR SEVERAL INCHES OF
SNOW BY THURSDAY MORNING ACROSS THE NORTHERN AND WESTERN
MOUNTAINS...WITH A FEW INCHES TO POSSIBLY A HALF FOOT AT LOWER
ELEVATIONS OF THE WEST CENTRAL AND NORTHWEST PLATEAU AND LIGHTER
AMOUNTS IN THE UPPER RIO GRANDE VALLEY. FARTHER SOUTH AND EAST THE
MAIN WEATHER CONCERN WILL BE WIND. THE POLAR JET STREAM WILL CROSS
SOUTHERN NM ON WEDNESDAY...THEN A STRONG SURFACE LOW IN THE LEE OF
THE SOUTHERN CO ROCKIES WILL KEEP THE PRESSURE GRADIENT TIGHT AND
WINDS STRONG ACROSS EASTERN NM WEDNESDAY NIGHT THROUGH THURSDAY.
GUSTS UP TO 50 MPH ARE EXPECTED FROM AROUND SOCORRO TO AROUND GRAN
QUIVIRA DURING EARLY AFTERNOON WEDNESDAY...THEN THESE STRONG WINDS
SHOULD SPREAD NORTHEASTWARD ALONG THE EAST SLOPES OF THE CENTRAL AND
SOUTHERN SANGRE DE CRISTO MOUNTAINS DURING THE LATE AFTERNOON AND
NIGHT. A COLD FRONT WILL ALSO CROSS FROM THE WEST WEDNESDAY AND
WEDNESDAY NIGHT...WITH MECHANICAL MIXING HELPING TO KEEP WINDS GOING
THROUGH THE NIGHT IN THE EAST.
IN THE WAKE OF THE COLD FRONT...HIGH TEMPERATURES THURSDAY WILL FALL
A FEW TO 8 DEGREES BELOW WEDNESDAYS READINGS. THE SURFACE PRESSURE
GRADIENT WILL REMAIN TIGHT IN THE EAST. WIND GUSTS TO 50 MPH ARE
EXPECTED TO CONTINUE FROM CLINES CORNERS TO SUMNER LAKE UNTIL SUNSET
THURSDAY EVENING. JUST AS THE FIRST UPPER LOW EXITS THURSDAY
MORNING...A TRAILING UPPER TROUGH WILL DIVE SOUTHEASTWARD THROUGH
THE FORECAST AREA THURSDAY AFTERNOON THROUGH FRIDAY. THIS WILL CAUSE
SNOW SHOWERS TO LINGER...BUT THIS SYSTEM WILL BE SIGNIFICANTLY
DRIER. THERE MAY BE A FEW INCHES OF ADDITIONAL SNOW ACCUMULATION IN
THE NORTHERN AND POSSIBLY THE WESTERN MOUNTAINS. HIGH TEMPERATURES
THURSDAY AND FRIDAY WILL VARY FROM 5 TO 20 DEGREES BELOW NORMAL.
THE AREA WILL BE BETWEEN STORM SYSTEMS SATURDAY. WEAK RIDGING WILL
PRODUCE TEMPERATURES 8 TO 15 DEGREES WARMER THAN FRIDAYS READINGS.
WEST WINDS WILL BECOME BREEZY TO WINDY AGAIN IN THE LEE OF THE
CENTRAL MOUNTAINS DUE TO A STRONG SURFACE LEE TROUGH AND
STRENGTHENING WINDS ALOFT AHEAD OF THE NEXT WEATHER SYSTEM. POCKETS
OF MINIMUM HUMIDITIES IN THE LOWER TEENS SHOULD RESULT IN AN HOUR OR
TWO OF CRITICAL FIRE WEATHER CONDITIONS ON THE EAST CENTRAL PLAINS.
A MORE CRITICAL FIRE WEATHER PATTERN MAY DEVELOP FOR NM SUNDAY AS AN
UPPER TROUGH STRENGTHENS INTO A CLOSED UPPER LOW WHILE PASSING
EASTWARD OVER CO AND/OR NORTHERN NM. THIS WILL STEER A STRONG POLAR
JET STREAK OVER THE SOUTHERN ROCKIES WHILE DRIVING A COLD FRONT
SOUTHWARD THROUGH NM. NW WIND GUSTS MAY PEAK AROUND 50 MPH FROM THE
SANDIA AND MANZANO MOUNTAINS EASTWARD ONTO THE EAST CENTRAL PLAINS.
MUCH OF THIS AREA MAY EXPERIENCE SEVERAL HOURS OF CRITICAL FIRE
WEATHER CONDITIONS. MODELS DISAGREE ON HOW FAR SOUTH THE UPPER LOW
WILL CROSS. IF IT DROPS AS FAR SOUTH AS NORTHERN NM...THEN THE
NORTHERN AND WESTERN MOUNTAINS COULD RECEIVE A FEW TO SEVERAL
ADDITIONAL INCHES OF SNOW BY MONDAY MORNING. MONDAY SHOULD SEE HIGH
TEMPERATURES ROUGHLY 6 TO 16 DEGREES BELOW NORMAL. AFTER AN EXTENDED
PERIOD OF GOOD TO EXCELLENT VENTILATION...MAX VENT RATES MONDAY MAY
NOT GET OUT OF THE POOR CATEGORY IN MANY LOWER ELEVATION
LOCATIONS.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM WEDNESDAY TO MIDNIGHT MST WEDNESDAY NIGHT
FOR THE FOLLOWING ZONES...NMZ520-524>526-537>540.
WINTER STORM WARNING FROM 6 AM WEDNESDAY TO 6 AM MST THURSDAY FOR
THE FOLLOWING ZONES...NMZ502>506-508>511.
WINTER STORM WARNING FROM 6 AM WEDNESDAY TO NOON MST THURSDAY FOR
THE FOLLOWING ZONES...NMZ512>514.
WINTER WEATHER ADVISORY FROM 6 AM WEDNESDAY TO 6 AM MST THURSDAY
FOR THE FOLLOWING ZONES...NMZ501-507-516.
&&
$$
40
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
917 PM EST THU FEB 21 2013
.SYNOPSIS...
HIGH PRESSURE WHICH HAS PROVIDED COLD TEMPERATURES WILL SLIDE OFF
TO THE EAST THIS EVENING. PRECIPITATION WILL DEVELOP ACROSS THE
AREA LATE THIS EVENING AHEAD OF AN APPROACHING WARM FRONT. A
WINTRY MIX OF SNOW AND SLEET...SHOULD TRANSITION TO FREEZING RAIN
AS TEMPERATURES REMAIN BELOW FREEZING AT THE SURFACE. TEMPERATURES
WILL RISE ABOVE FREEZING AND THE FREEZING RAIN WILL TRANSITION TO
RAIN LATE TONIGHT THROUGH FRIDAY MORNING. A COLD FRONT WILL THEN
PUSH ACROSS THE AREA FRIDAY NIGHT WITH SEASONABLE TEMPERATURES
EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE FORECAST HAS BEEN UPDATED TONIGHT WITH A FEW CHANGES.
FIRST...POPS WERE INCREASED AND SPED UP...AS PRECIPITATION HAS
ALREADY ENTERED ABOUT A THIRD OF THE CWA. TIMING WAS BASED HEAVILY
ON LATEST HRRR RUNS...WITH THE BACK EDGE OF THE PRECIPITATION ALSO
SPED UP A LITTLE BIT TOMORROW MORNING. GIVEN THE CERTAINTY OF
PRECIPITATION...100 PERCENT CHANCES WERE USED EVERYWHERE.
THE MORE COMPLICATED DECISIONS WERE RELATED TO PRECIPITATION TYPE.
IT IS APPARENT FROM THE RECENT OBSERVATIONS THAT THE WARM
ADVECTION ALOFT IS PERHAPS OCCURRING SLIGHTLY SLOWER THAN WAS
EARLIER FORECAST. ON THE OTHER HAND...THIS COULD ALSO BE THE
RESULT OF THE FASTER ONSET OF PRECIPITATION THAN WAS PREVIOUSLY
ANTICIPATED. BECAUSE OF THIS...HYDROMETEORS AT PRECIP ONSET ARE
NOT COMPLETING MELTING...LEADING TO A PLETHORA OF SLEET OBS OVER
THE ILN CWA...AND A POCKET OF MODERATE SNOW NOW MOVING INTO THE
WHITEWATER VALLEY AREA.
FREEZING RAIN IS STILL EXPECTED TO BE THE PRIMARY PRECIPITATION
TYPE OVERNIGHT...BUT THE GRIDS NOW REFLECT A GREATER MIXING IN THE
FIRST FEW HOURS OF THE FORECAST. SNOW/SLEET ACCUMULATIONS OF UP TO
A HALF INCH WERE ADDED INTO THE INDIANA COUNTIES AND WESTERN MIAMI
VALLEY (MAINLY EXPECTED IN THE NEXT FEW HOURS)...WITH THE ORIGINAL
FORECAST OF UP TO AN INCH OF SNOW IN THE FAR NORTH STILL ON TRACK.
THE WINTER WEATHER ADVISORY ISSUED BY THE DAY SHIFT COVERS THIS
MIX OF PRECIPITATION QUITE WELL...SO WHILE UPDATES WERE MADE TO
ADD SOME OF THE NEW DETAIL...THE OVERALL PLAN AND LAYOUT FOR THE
HEADLINE PRODUCT HAS NOT CHANGED.
PREVIOUS DISCUSSION >
FOCUS IS ON POTENTIAL FOR ICE EVENT TONIGHT/FRIDAY MORNING IN THE
OHIO VALLEY. UPPER LEVEL AND SFC LOW OVER CENTRAL PLAINS TO EJECT
NE INTO THE MID MS VLY BY 12Z FRIDAY. FAVORABLE ISENTROPIC LIFT
DEVELOPS AHD OF THIS SYSTEM ACRS ILN/S FA TONIGHT. SOUTHERLY 8H
JET OF 60KTS WEAKENS TO 50-55KTS AS IT MOVES INTO THE OHIO VALLEY
BY MORNING. THIS JET WORKS TO PROVIDE GOOD FORCING AND WAA. THE
BEST LIFT DEVELOPS BETWEEN 06Z AND 12Z. WILL CONTINUE RAMPING POPS
UP TO CATEGORICAL LATE THIS EVENING INTO EARLY FRIDAY. QUESTION
REVOLVES AROUND QPF/THERMAL PROFILES AND ULTIMATELY THE AMOUNT OF
ICING. NAM IS THE MORE ENERGETIC WITH FORCING AND THEREFORE HAS
HIGHER QPF. 12Z RUN SOLNS ARE CLOSER AND THEREFORE HAVE GONE WITH
A BLENDED SOLN. UNDER STRONG WAA...TEMPS ALOFT WARM SUFFICIENTLY
FOR LIQUID WHILE SFC TEMPS REMAIN BELOW FREEZING WITH A LOW LEVEL
EASTERLY FLOW.
EXPECT NON-DIURNAL TEMPERATURES WITH READINGS RISING ABOVE
FREEZING ACRS THE FAR SOUTH TOWARD SUNRISE. BASED ON A PROLONGED
PERIOD OF BELOW FREEZING TEMPERATURES EXPECT 1 TO 2 TENTHS OF AN
INCH OF ICE ACCUMULATION WITH THE HIGHEST AMOUNTS ACRS EAST
CENTRAL INDIANA/WHITEWATER VALLEY AND THE MIAMI VALLEY. WILL
CONTINUE WINTER WEATHER ADVISORIES ACRS THE ENTIRE FA FOR THIS
ICE IMPACT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
UPPER LEVEL/SFC LOW PRESSURE TO MIGRATE SLOWLY NE FROM THE UPR MS
VLY INTO THE WESTERN GREAT LAKES FRIDAY. NUMERICAL MODEL SOLNS
CONSISTENT WITH DEEP MSTR AND FORCING ASSOCIATED WITH STRONG LLJ
SHIFTING NE OF ILNS FA FRIDAY MORNING. AT THE SAME TIME UNDER THE
INFLUENCE OF WAA...SFC TEMPERATURES WARM ABOVE FREEZING BY MIDDAY
FROM SOUTH TO NORTH. WILL DIMINISH POPS A LTL QUICKER TO REFLECT
THIS FASTER TIMING AS THE FAVORABLE FORCING EXITS THE REGION.
EXPECT HIGH TEMPS TO BE A LTL ABOVE NORMAL...RANGING FROM THE
UPPER 30S NW TO THE LOWER 50S FAR SOUTH.
SFC LOW TO MIGRATE THRU THE GREAT LAKES WITH A TRAILING COLD
FRONT FROM THE LOW CROSSING THE FORECAST AREA FRIDAY NIGHT. THIS
WILL BRING A RETURN TO COLDER...MORE SEASONABLE TEMPERATURES. DUE
TO A LACK OF SIGNIFICANT FORCING AND MSTR HAVE ONLY CONTINUED
SLIGHT CHC POPS ACRS THE FAR NORTH. FRIDAY NIGHTS LOWS WILL RANGE
FROM THE UPPER 20S NORTHWEST TO THE MID 30S SE.
UPPER LOW TO CONTINUE TO WORK ACRS THE GREAT LAKES SAT/SAT NIGHT.
BETTER MSTR LOOKS TO STAY NORTH OF ILNS/ FA AND IT APPEARS AT
THIS TIME THAT THE FLOW TRAJECTORIES AROUND THE LOW WILL NOT BE
FAVORABLE TO BRING ANY SNOW SHOWERS INTO OUR AREA. THEREFORE HAVE
MAINTAINED A DRY FCST. EXPECT SATURDAYS HIGHS TO BE A LTL BELOW
NORMAL...RANGING FROM THE MID 30S NW TO THE MID 40S SE. LOWS SAT
NIGHT ARE EXPECTED TO RANGE FROM THE LOWER 20S NW TO THE MID 20S SE.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MODELS SHOW HIGH PRESSURE BUILDING IN ON SUNDAY SO KEPT THE FORECAST
DRY. NEXT SYSTEM DUE TO ARRIVE LATE MONDAY IS SLOWER ON LATEST MODEL
RUNS...SO HELD BACK ONSET AND ENDING OF SHOWERS BY A FEW HOURS.
COLDER TEMPERATURES EARLY MONDAY NIGHT MAY ALLOW SNOW TO MIX IN FOR
A TIME. MAIN BAND OF SHOWERS SHOULD EXIT EAST TUESDAY AFTERNOON.
A COLDER PATTERN WITH A LINGERING LOW OVER THE GREAT LAKES WILL SET
UP TUESDAY NIGHT THROUGH THURSDAY. THIS WILL RESULT IN A FEW ROUNDS
OF SNOW SHOWERS...WITH RAIN POSSIBLY MIXING IN AT SOUTHERN
LOCATIONS.
COOL READINGS AROUND 40 ON SUNDAY WILL BE BOOSTED CLOSE TO 50 ON
MONDAY DUE TO WARM ADVECTION AHEAD OF THE LOW. BELOW NORMAL HIGHS IN
THE 30S ARE EXPECTED BY THURSDAY IN A NORTHWESTERLY LOW LEVEL FLOW.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
THE AVIATION STORY FOR TONIGHT WILL BE A MIX OF
PRECIPITATION...WHICH IS EXPECTED TO BEGIN AT THE TAF SITES WITHIN
THE NEXT FEW HOURS. COLD AIR AT THE SURFACE WILL SUPPORT ICY
PRECIPITATION TYPES...EVEN AS TEMPERATURES WARM ALOFT.
ALTHOUGH THERE IS STILL SOME UNCERTAINTY IN THE EXACT
PRECIPITATION TYPES EXPECTED...THE TAFS HAVE BEEN LAID OUT WITH
THE MOST LIKELY PREVAILING SOLUTION. FOR CINCINNATI...ONSET IS
EXPECTED AS FREEZING RAIN...WITH SOME ICE PELLETS ALSO POSSIBLE.
FURTHER NORTH...A MIX OF SNOW AND ICE PELLETS WILL BE POSSIBLE IN
THE FIRST COUPLE HOURS OF PRECIPITATION...BEFORE FREEZING RAIN
BECOMES THE PREVAILING PRECIPITATION TYPE. AS TEMPERATURES WARM UP
ON FRIDAY MORNING...PRECIPITATION WILL TURN TO REGULAR RAIN AS IT
EXITS THE AREA. ICE ACCUMULATIONS ARE EXPECTED TO BE THE HEAVIEST
AT THE DAYTON TAF SITE...WITH ONE TO TWO TENTHS OF AN INCH
EXPECTED.
CEILINGS WILL GRADUALLY LOWER THROUGH THE EVENT...AS THE
ATMOSPHERE BECOMES MORE AND MORE MOIST. IFR CEILINGS ARE EXPECTED
NEAR THE END OF PRECIPITATION...AND WELL INTO THE DAY
FRIDAY...ESPECIALLY IN THE NORTH. IN TERMS OF
VISIBILITY...WIDESPREAD MVFR CONDITIONS ARE EXPECTED IN THE
PRECIPITATION. SOME IFR CONDITIONS WILL BE POSSIBLE IN SNOW...AND
ALSO IN HEAVIER RAIN/FZRA SHOWERS. IF CONDITIONS END UP FAVORING A
BRIEF PERIOD OF HEAVY SNOW FOR THE NORTHERN TAF SITES (BEFORE THE
SWITCH TO FZRA)...THEN LIFR VISIBILITIES MAY BE POSSIBLE.
WINDS WILL SHIFT SIGNIFICANTLY DURING THE TAF PERIOD...GOING FROM
NORTHEASTERLY TO WESTERLY IN A CLOCKWISE DIRECTION. SOME GUSTS TO
NEAR 20 KNOTS WILL BE POSSIBLE...THOUGH A PREVAILING 10-15 KNOT
SUSTAINED WIND APPEARS MORE LIKELY GIVEN THAT THE STRONGER WINDS
ALOFT ARE NOT EXPECTED TO READILY MIX DOWN TO THE SURFACE.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO FRIDAY NIGHT...AND
POSSIBLY THROUGH SATURDAY FOR THE NORTHERN TAF SITES. MVFR
CONDITIONS ARE POSSIBLE AGAIN ON MONDAY AND TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-080-082.
WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR OHZ077>079-
081-088.
KY...WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR INZ050-058-
059-066.
WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR INZ073>075-
080.
&&
$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
620 AM EST WED FEB 20 2013
.SYNOPSIS...
LOW PRESSURE OVER THE GREAT LAKES WILL LIFT AWAY FROM OUR REGION
TODAY. HIGH PRESSURE WILL BUILD IN ACROSS OUR AREA TONIGHT AND
THURSDAY. ANOTHER LOW PRESSURE SYSTEM WILL BRING A WINTRY MIX OF
PRECIPITATION TO THE OHIO VALLEY THURSDAY NIGHT AND INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW LEVEL CONVERGENCE ON THE BACK SIDE OF LOW PRESSURE OVER THE
GREAT LAKES IS CONTINUING TO BRING SNOW SHOWERS TO MUCH OF THE
FORECAST AREA THIS MORNING. RUC13 AND RADAR TRENDS INDICATE THAT
THIS AREA OF SHOWERS WILL GRADUALLY SAG SOUTH AND EAST OVER THE
NEXT FEW HOURS...WHILE DECREASING IN COVERAGE. EXTENDED POPS INTO
THE MORNING COMMUTE...BEFORE TAPERING OF BY LATE THIS MORNING.
A WEAK VORT MAX WILL SWING AROUND THE UPPER LOW ACROSS THE GREAT
LAKES THIS AFTERNOON. THIS WILL BRING ANOTHER ROUND OF POTENTIAL
SNOW SHOWERS TO THE NORTHERN PORTIONS OF THE FORECAST AREA. WAS
NOT CONVINCED THAT WE WILL SEE ANY MEASURABLE LIQUID FROM THIS
AFTERNOON`S SNOW ACROSS THE NORTH. THEREFORE EMPHASIZED THIS
PRECIPITATION WITH CHANCE/LIKELY FLURRIES. BROKEN CLOUD COVER
WILL LIKELY REMAIN IN PACE ACROSS THE NORTH FOR THE ENTIRE
DAY...WITH SKIES BEGINNING TO CLEAR OUT ACROSS THE SOUTH THIS
AFTERNOON. TEMPERATURES WILL STRUGGLE TO REACH THE MID 20S THIS
AFTERNOON ACROSS THE CLOUDIER NORTH WITH COLDER AIR ALOFT.
TEMPERATURES WILL REACH THE LOW 30S ACROSS THE SOUTH WITH MORE
SUNSHINE AND LESSER COLD AIR ALOFT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
THE LOW OVER THE GREAT LAKES WILL ACCELERATE NORTHEASTWARD THIS
EVENING...AS CANADIAN HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE
OHIO VALLEY. THIS WILL BRING AN END TO ANY LINGERING FLURRIES THAT
MAY BE OCCURRING IN OUR AREA. SKIES ARE EXPECTED TO BECOME PARTLY
CLOUDY OVERNIGHT AND INTO THE DAY THURSDAY UNDER HIGH PRESSURE.
TEMPERATURES TONIGHT WILL BE COLD UNDER THIS AIRMASS AND PARTLY
CLOUDY SKIES. EXPECT OVERNIGHT LOWS TO DROP INTO THE LOW TEENS
ACROSS THE NORTH AND UPPER TEENS ACROSS THE SOUTH. CANNOT RULE OUT
A FEW SINGLE DIGITS IN THE TYPICALLY COLDER LOW LYING AREAS.
A STORM SYSTEM LIFTING NORTHEASTWARD ACROSS THE PLAINS WILL BE THE
FOCUS OF OUR NEXT WEATHER EVENT IN THE OHIO VALLEY. THIS SYSTEM
WILL GRADUALLY WEAKEN AS IT LIFTS TOWARD THE GREAT LAKES THURSDAY
NIGHT AND FRIDAY. PRECIPITATION WILL SPREAD WELL AHEAD OF THE
SYSTEM AS AN ELEVATED WARM FRONT MAKES ITS WAY TOWARD THE OHIO
VALLEY. THE REGION OF MORE FAVORABLE ISENTROPIC LIFT WILL NOT
ARRIVE UNTIL AFTER 00Z FRIDAY SO HOLD OF ON BRINGING ANY CATEGORICAL
POPS UNTIL EARLY FRIDAY MORNING.
THE MOST IMPORTANT ASPECT OF THIS SYSTEM WILL BE THE WARM WEDGE OF
AIR ALOFT THAT WILL MOVE ACROSS OUR AREA AHEAD OF THE SURFACE WARM
FRONT LATE THURSDAY...BEFORE THE ISENTROPIC LIFT BRINGS US
PRECIPITATION. THIS WARM AIR ALOFT IS DEEP ENOUGH TO CAUSE MOST
PRECIPITATION TO BE LIQUID BY THE TIE IT REACHES THE BOTTOM OF THE
WARM LAYER. AS OF THIS FORECAST PACKAGE IT APPEARS THAT EASTERLY
FLOW AT THE SURFACE AROUND THE DEPARTING CANADIAN HIGH PRESSURE
WILL KEEP TEMPERATURES BELOW FREEZING ACROSS AT LEAST THE NORTHERN
TWO THIRDS OF OUR AREA FOR MOST OF PRE DAWN HOURS FRIDAY...POSING
A THREAT FOR FREEZING RAIN. ALTHOUGH THE BAND OF PRECIPITATION WILL
BE DECREASING IN INTENSITY AS IT ARRIVES ACROSS THE OHIO
VALLEY...THERE WILL BE ENOUGH LIQUID EQUIVALENT TO CAUSE ISSUES
DUE TO ICE ACCUMULATION POTENTIAL. CURRENT BLENDED QPFS YIELD ABOUT
.15 TO .20 INCHES OF TOTAL LIQUID THURSDAY NIGHT...WITH THE MOST
FAVORABLE ICING CONDITIONS ACROSS THE NORTHWEST. THIS COULD RESULT
IN JUST OVER A TENTH OF AN INCH OF ICE ACCUMULATION THERE...WITH
JUST UNDER A TENTH OF AN INCH ACROSS THE CENTRAL ZONES.
TEMPERATURES SHOULD BE WARM ENOUGH ACROSS THE SOUTH FOR MAINLY AN
ALL RAIN EVENT. MORE FINE TUNING OF TIMING AND QPF/ICE AMOUNTS CAN
BE EXPECTED AS THE ARRIVAL OF THIS SYSTEM DRAWS NEARER.
THE SURFACE WARM FRONT WILL CROSS THE FORECAST AREA AFTER DAYBREAK
FRIDAY MORNING...BRINGING A TRANSITION TO ALL RAIN TO OUR AREA. AT
THIS POINT ANY PRECIPITATION THAT WILL OCCUR WILL BE LIGHT. WARMER
TEMPERATURES WILL WORK THEIR WAY NORTHWARD DURING THE DAY
FRIDAY...WITH TEMPERATURES POTENTIALLY REACHING THE MID TO UPPER
50S ACROSS THE SOUTH...AND THE LOWER 40S ACROSS THE NORTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LOW PRESSURE SYSTEM WILL BEGIN TO MOVE OUT OF THE FA FRIDAY
NIGHT AND PRECIPITATION WILL COME TO AN END. HIGH PRESSURE WILL
WORK INTO THE REGION FOR THE REMAINDER OF THE WEEKEND. THE COLDEST
NIGHT WILL BE SATURDAY NIGHT DUE TO LIGHT WINDS AND SKIES BECOMING
MOSTLY CLEAR. TEMPERATURES WILL DROP DOWN INTO GENERALLY THE MID
20S SATURDAY NIGHT.
MODELS START TO DIVERGE FOR MONDAY AND TUESDAY. THE GFS IS
SIGNIFICANTLY FASTER WITH THIS SYSTEM THAN THE ECMWF. WENT WITH A
BLEND HOWEVER WENT CLOSER TO THE SLOWER ECMWF SOLUTION. WITH THIS
SOLUTION PRECIPITATION WILL BEGIN TO EDGE INTO THE FA DURING THE
AFTERNOON HOURS ON MONDAY AND BECOME MORE WIDESPREAD ACROSS THE FA
MONDAY NIGHT INTO TUESDAY. PRECIPITATION WILL THEN TAPER OFF ACROSS
THE FA TUESDAY EVENING. TEMPERATURE PROFILES ARE WARM ENOUGH WITH
THIS SYSTEM THAT PRECIPITATION WILL BE IN THE FORM OF RAIN.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
FLURRIES ARE CONTINUING ACROSS MUCH OF THE REGION THIS
MORNING...WITH LIGHT RETURNS ON RADAR EXTENDING BACK INTO CENTRAL
INDIANA. BASED ON SATELLITE IMAGES...IT DOES LOOK LIKE SOME PARTIAL
CLEARING IS TRYING TO WORK IN TOWARD KCVG/KLUK SO WE MAY SEE SOME
IMPROVEMENT THERE IN THE NEXT FEW HOURS. FARTHER NORTH...WILL KEEP
THINGS A BIT MORE PESSIMISTIC WITH MVFR CIGS AND SOME FLURRIES
LINGERING THROUGH NOON OR SO. IT LOOKS LIKE A FETCH OFF OF LAKE
MICHIGAN COULD KEEP SOME CLOUDS AND A FEW FLURRIES PERSISTING
ACROSS THE NORTH THROUGH THIS AFTERNOON. DRIER AIR TRIES TO WORK
IN FROM THE SOUTHWEST OVERNIGHT...BUT WILL BE SLOW TO CLEAR OUT
KCMH/KLCK AS LOW LEVEL FLOW VEERS TO A MORE NORTHERLY DIRECTION
THROUGH THE NIGHT.
OUTLOOK...A WINTRY MIX IS EXPECTED THURSDAY NIGHT INTO FRIDAY
MORNING WITH SOME SLEET AND ICE ACCUMULATION LIKELY. IN ADDITION
MVFR CEILINGS AND VISIBILITIES WILL BE LIKELY WITH A PERIOD OF IFR
CONDITIONS POSSIBLE. MVFR CEILINGS MAY CONTINUE THROUGH FRIDAY
NIGHT AND INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
423 AM EST WED FEB 20 2013
.SYNOPSIS...
LOW PRESSURE OVER THE GREAT LAKES WILL LIFT AWAY FROM OUR REGION
TODAY. HIGH PRESSURE WILL BUILD IN ACROSS OUR AREA TONIGHT AND
THURSDAY. ANOTHER LOW PRESSURE SYSTEM WILL BRING A WINTRY MIX OF
PRECIPITATION TO THE OHIO VALLEY THURSDAY NIGHT AND INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW LEVEL CONVERGENCE ON THE BACK SIDE OF LOW PRESSURE OVER THE
GREAT LAKES IS CONTINUING TO BRING SNOW SHOWERS TO MUCH OF THE
FORECAST AREA THIS MORNING. RUC13 AND RADAR TRENDS INDICATE THAT
THIS AREA OF SHOWERS WILL GRADUALLY SAG SOUTH AND EAST OVER THE
NEXT FEW HOURS...WHILE DECREASING IN COVERAGE. EXTENDED POPS INTO
THE MORNING COMMUTE...BEFORE TAPERING OF BY LATE THIS MORNING.
A WEAK VORT MAX WILL SWING AROUND THE UPPER LOW ACROSS THE GREAT
LAKES THIS AFTERNOON. THIS WILL BRING ANOTHER ROUND OF POTENTIAL
SNOW SHOWERS TO THE NORTHERN PORTIONS OF THE FORECAST AREA. WAS
NOT CONVINCED THAT WE WILL SEE ANY MEASURABLE LIQUID FROM THIS
AFTERNOON`S SNOW ACROSS THE NORTH. THEREFORE EMPHASIZED THIS
PRECIPITATION WITH CHANCE/LIKELY FLURRIES. BROKEN CLOUD COVER
WILL LIKELY REMAIN IN PACE ACROSS THE NORTH FOR THE ENTIRE
DAY...WITH SKIES BEGINNING TO CLEAR OUT ACROSS THE SOUTH THIS
AFTERNOON. TEMPERATURES WILL STRUGGLE TO REACH THE MID 20S THIS
AFTERNOON ACROSS THE CLOUDIER NORTH WITH COLDER AIR ALOFT.
TEMPERATURES WILL REACH THE LOW 30S ACROSS THE SOUTH WITH MORE
SUNSHINE AND LESSER COLD AIR ALOFT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
THE LOW OVER THE GREAT LAKES WILL ACCELERATE NORTHEASTWARD THIS
EVENING...AS CANADIAN HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE
OHIO VALLEY. THIS WILL BRING AN END TO ANY LINGERING FLURRIES THAT
MAY BE OCCURRING IN OUR AREA. SKIES ARE EXPECTED TO BECOME PARTLY
CLOUDY OVERNIGHT AND INTO THE DAY THURSDAY UNDER HIGH PRESSURE.
TEMPERATURES TONIGHT WILL BE COLD UNDER THIS AIRMASS AND PARTLY
CLOUDY SKIES. EXPECT OVERNIGHT LOWS TO DROP INTO THE LOW TEENS
ACROSS THE NORTH AND UPPER TEENS ACROSS THE SOUTH. CANNOT RULE OUT
A FEW SINGLE DIGITS IN THE TYPICALLY COLDER LOW LYING AREAS.
A STORM SYSTEM LIFTING NORTHEASTWARD ACROSS THE PLAINS WILL BE THE
FOCUS OF OUR NEXT WEATHER EVENT IN THE OHIO VALLEY. THIS SYSTEM
WILL GRADUALLY WEAKEN AS IT LIFTS TOWARD THE GREAT LAKES THURSDAY
NIGHT AND FRIDAY. PRECIPITATION WILL SPREAD WELL AHEAD OF THE
SYSTEM AS AN ELEVATED WARM FRONT MAKES ITS WAY TOWARD THE OHIO
VALLEY. THE REGION OF MORE FAVORABLE ISENTROPIC LIFT WILL NOT
ARRIVE UNTIL AFTER 00Z FRIDAY SO HOLD OF ON BRINGING ANY CATEGORICAL
POPS UNTIL EARLY FRIDAY MORNING.
THE MOST IMPORTANT ASPECT OF THIS SYSTEM WILL BE THE WARM WEDGE OF
AIR ALOFT THAT WILL MOVE ACROSS OUR AREA AHEAD OF THE SURFACE WARM
FRONT LATE THURSDAY...BEFORE THE ISENTROPIC LIFT BRINGS US
PRECIPITATION. THIS WARM AIR ALOFT IS DEEP ENOUGH TO CAUSE MOST
PRECIPITATION TO BE LIQUID BY THE TIE IT REACHES THE BOTTOM OF THE
WARM LAYER. AS OF THIS FORECAST PACKAGE IT APPEARS THAT EASTERLY
FLOW AT THE SURFACE AROUND THE DEPARTING CANADIAN HIGH PRESSURE
WILL KEEP TEMPERATURES BELOW FREEZING ACROSS AT LEAST THE NORTHERN
TWO THIRDS OF OUR AREA FOR MOST OF PRE DAWN HOURS FRIDAY...POSING
A THREAT FOR FREEZING RAIN. ALTHOUGH THE BAND OF PRECIPITATION WILL
BE DECREASING IN INTENSITY AS IT ARRIVES ACROSS THE OHIO
VALLEY...THERE WILL BE ENOUGH LIQUID EQUIVALENT TO CAUSE ISSUES
DUE TO ICE ACCUMULATION POTENTIAL. CURRENT BLENDED QPFS YIELD ABOUT
.15 TO .20 INCHES OF TOTAL LIQUID THURSDAY NIGHT...WITH THE MOST
FAVORABLE ICING CONDITIONS ACROSS THE NORTHWEST. THIS COULD RESULT
IN JUST OVER A TENTH OF AN INCH OF ICE ACCUMULATION THERE...WITH
JUST UNDER A TENTH OF AN INCH ACROSS THE CENTRAL ZONES.
TEMPERATURES SHOULD BE WARM ENOUGH ACROSS THE SOUTH FOR MAINLY AN
ALL RAIN EVENT. MORE FINE TUNING OF TIMING AND QPF/ICE AMOUNTS CAN
BE EXPECTED AS THE ARRIVAL OF THIS SYSTEM DRAWS NEARER.
THE SURFACE WARM FRONT WILL CROSS THE FORECAST AREA AFTER DAYBREAK
FRIDAY MORNING...BRINGING A TRANSITION TO ALL RAIN TO OUR AREA. AT
THIS POINT ANY PRECIPITATION THAT WILL OCCUR WILL BE LIGHT. WARMER
TEMPERATURES WILL WORK THEIR WAY NORTHWARD DURING THE DAY
FRIDAY...WITH TEMPERATURES POTENTIALLY REACHING THE MID TO UPPER
50S ACROSS THE SOUTH...AND THE LOWER 40S ACROSS THE NORTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LOW PRESSURE SYSTEM WILL BEGIN TO MOVE OUT OF THE FA FRIDAY
NIGHT AND PRECIPITATION WILL COME TO AN END. HIGH PRESSURE WILL
WORK INTO THE REGION FOR THE REMAINDER OF THE WEEKEND. THE COLDEST
NIGHT WILL BE SATURDAY NIGHT DUE TO LIGHT WINDS AND SKIES BECOMING
MOSTLY CLEAR. TEMPERATURES WILL DROP DOWN INTO GENERALLY THE MID
20S SATURDAY NIGHT.
MODELS START TO DIVERGE FOR MONDAY AND TUESDAY. THE GFS IS
SIGNIFICANTLY FASTER WITH THIS SYSTEM THAN THE ECMWF. WENT WITH A
BLEND HOWEVER WENT CLOSER TO THE SLOWER ECMWF SOLUTION. WITH THIS
SOLUTION PRECIPITATION WILL BEGIN TO EDGE INTO THE FA DURING THE
AFTERNOON HOURS ON MONDAY AND BECOME MORE WIDESPREAD ACROSS THE FA
MONDAY NIGHT INTO TUESDAY. PRECIPITATION WILL THEN TAPER OFF ACROSS
THE FA TUESDAY EVENING. TEMPERATURE PROFILES ARE WARM ENOUGH WITH
THIS SYSTEM THAT PRECIPITATION WILL BE IN THE FORM OF RAIN.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
FLURRIES AND SNOW SHOWERS ARE STILL WIDESPREAD ACROSS THE AREA
EARLY THIS MORNING. WITH CONTINUING WEAK CYCLONIC LOW LEVEL FLOW
AND LINGERING 850 MB MOISTURE...WILL PLAY THE TAFS PRETTY
PESSIMISTIC AND HANG ON TO FLURRIES THROUGH AT LEAST DAYBREAK.
CIGS AND VSBYS WILL GENERALLY REMAIN VFR BUT MAY OCCASIONALLY DROP
INTO MVFR WITH SOME OF THE MORE SIGNIFICANT SNOW SHOWERS. MODELS
ARE TRYING TO INDICATE SOME DRYING TRYING TO WORK IN THROUGH THIS
AFTERNOON SO WILL TRY TO BRING SOME PARTIAL CLEARING LATER
TODAY INTO AT LEAST THE SOUTHWEST.
OUTLOOK...A WINTRY MIX IS EXPECTED THURSDAY NIGHT INTO FRIDAY
MORNING WITH SOME SLEET AND ICE ACCUMULATION LIKELY. IN ADDITION
MVFR CEILINGS AND VISIBILITIES WILL BE LIKELY WITH A PERIOD OF IFR
CONDITIONS POSSIBLE. MVFR CEILINGS MAY CONTINUE THROUGH FRIDAY
NIGHT AND INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1222 AM EST WED FEB 20 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL MOVE EAST OF THE REGION TONIGHT AS
A CANADIAN HIGH PRESSURE SYSTEM BUILDS OVER THE GREAT LAKES
THROUGH THURSDAY. AN AREA OF LOW PRESSURE WILL LIFT NORTHEAST OUT
OF THE PLAINS ON THURSDAY...SPREADING A WINTRY MIX OF
PRECIPITATION ACROSS THE OHIO VALLEY THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
RADAR STILL SHOWING SOME ISOLATED TO SCATTERED SNOW SHOWERS.
APPEARS THAT AXIS OF ACTIVITY HAS DRIFTED SOUTH. HRRR AND RAP RUNS
SUGGEST THAT THE SOUTHERN COUNTIES WILL BE MORE FAVORABLE FOR ANY
ADDITIONAL ACTIVITY THROUGH THE NIGHT. OTHERWISE MOST OF THE
PRECIPITATION HAS TAPERED OFF TO FLURRIES.
SATELLITE IMAGERY SHOWS EXTENSIVE CLOUD COVER ACROSS THE REGION.
THERE IS SOME CLEARING IN NORTHERN OHIO AND WESTERN INDIANA. LOW
LEVEL MOISTURE FORECASTS SUGGEST THAT SOME OF THESE BREAKS MAY GET
INTO THE EDGES OF THE FORECAST AREA. BUT FOR THE MOST PART CLOUDS
WILL PREVAIL. GUSTY WEST WINDS WILL CONTINUE. FORECAST
TEMPERATURES LOOK REASONABLE FOR THE MOST PART WITH ONLY MINOR
ADJUSTMENTS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE OHIO VALLEY FOR
WEDNESDAY AND MOST OF THURSDAY. EXPECT MAINLY CLEAR SKIES ACROSS
THE FORECAST AREA THROUGH THIS PERIOD...WITH THE EXCEPTION OF SOME
LINGERING CLOUDINESS ACROSS THE NORTH AND EAST ON WEDNESDAY THANKS TO
ONGOING MOIST FLOW OFF THE LAKES. TEMPERATURES WILL BE AROUND 10
TO 15 DEGREES BELOW SEASONAL NORMALS FOR WEDNESDAY AND WEDNESDAY
NIGHT...WARMING SLIGHTLY FOR THURSDAY AS THE SURFACE HIGH DRIFTS
EAST OF THE AREA.
MAIN FOCUS FOR THIS PERIOD WILL BE ON A STRONG STORM SYSTEM OVER
THE PLAINS THAT WILL BE WEAKENING AS IT LIFTS NORTHEASTWARD TOWARDS
THE OHIO VALLEY. MODELS HAVE BEEN SHOWING A MARKED DECREASE IN
PRECIPITATION ASSOCIATED WITH THIS SYSTEM BY THE TIME IT GETS TO
OUR AREA AS ITS FEED OF GULF MOISTURE SUBSTANTIALLY DROPS OFF THE
FURTHER EAST IT PROGRESSES. HOWEVER...THERE IS STILL A GOOD POTENTIAL
FOR A FREEZING RAIN EVENT ACROSS THE FORECAST AREA.
ISENTROPIC LIFT WILL RAMP UP ACROSS THE AREA THURSDAY EVENING AS
AN ELEVATED WARM FRONT PUSHES NORTH. LATEST MODEL RUNS HAVE COME
INTO GOOD AGREEMENT WITH PRECIPITATION MOVING INTO THE TRI-STATE
AREA AFTER 00Z FRIDAY. THE PRECIPITATION THEN WILL SPREAD
NORTHEAST ACROSS THE REST OF THE FORECAST AREA OVERNIGHT INTO
FRIDAY MORNING.
AS FOR PRECIP TYPES...A RATHER DEEP ELEVATED WARM LAYER WITH
MAXIMUM TEMPERATURES AROUND 3 DEG C WILL BE IN PLACE OVER THE AREA
BY THE TIME PRECIPITATION BEGINS THURSDAY EVENING. A SHALLOW
FREEZING LAYER WILL ALSO BE IN PLACE NEAR THE SURFACE...AND
SURFACE TEMPERATURES ACROSS THE FORECAST AREA WILL RANGE FROM THE
MID 20S IN THE NORTH TO THE LOWER 30S IN THE SOUTH. ALL THIS
INDICATES THAT FREEZING RAIN WILL LIKELY BE THE PREDOMINANT
P-TYPE...WITH SOME RAIN ACROSS THE SOUTH OVERNIGHT WHERE SURFACE
TEMPERATURES RISE ABOVE FREEZING. A BRIEF PERIOD OF SLEET WILL
ALSO BE POSSIBLE AS THE PRECIP SPREADS ACROSS THE FORECAST
AREA...THOUGH NOT EXPECTING ANY SIGNIFICANT SLEET ACCUMULATION
ATTM. STORM TOTAL ICE ACCRETIONS LOOK TO BE GREATEST ACROSS THE
WHITEWATER AND MIAMI VALLEYS WHERE AROUND A TENTH OF AN INCH OR
MORE IS FORECASTED. ICING WILL BE LESS NEAR AND SOUTH OF THE OHIO
RIVER WHERE SURFACE TEMPS WILL BE WARMER AND RAIN WILL BE MIXING
IN. ICING WILL ALSO BE LESS ACROSS CENTRAL OHIO AS THE SYSTEM IS
NOT EXPECTED TO PRODUCE AS MUCH PRECIP BY THE TIME IT GETS THERE.
WILL CONTINUE TO MONITOR THIS SYSTEM AS IT DRAWS CLOSER FOR MORE
ADJUSTMENTS TO ICING AMOUNTS AND TIMING BUT WILL CONTINUE TO MENTION
IN HWO FOR NOW.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
WITH WARM AIR ALOFT AND TEMPERATURES BELOW FREEZING AT THE SURFACE
ACROSS MUCH OF THE FA FRIDAY MORNING FREEZING RAIN WILL BE PRESENT
ACROSS A MAJORITY OF THE FA. TEMPERATURES WILL WARM ACROSS THE FA
THROUGH THE DAY ON FRIDAY AND AS THEY DO EXPECT PRECIPITATION TO
CHANGE FROM FREEZING RAIN TO RAIN ACROSS THE FA.
THE LOW PRESSURE SYSTEM WILL BEGIN TO MOVE OUT OF THE FA FRIDAY
NIGHT AND PRECIPITATION WILL COME TO AN END. HIGH PRESSURE WILL
WORK INTO THE REGION FOR THE REMAINDER OF THE WEEKEND. THE COLDEST
NIGHT WILL BE SATURDAY NIGHT DUE TO LIGHT WINDS AND SKIES BECOMING
MOSTLY CLEAR. TEMPERATURES WILL DROP DOWN INTO GENERALLY THE MID
20S SATURDAY NIGHT.
MODELS START TO DIVERGE FOR MONDAY AND TUESDAY. THE GFS IS
SIGNIFICANTLY FASTER WITH THIS SYSTEM THAN THE ECMWF. WENT WITH A
BLEND HOWEVER WENT CLOSER TO THE SLOWER ECMWF SOLUTION. WITH THIS
SOLUTION PRECIPITATION WILL BEGIN TO EDGE INTO THE FA DURING THE
AFTERNOON HOURS ON MONDAY AND BECOME MORE WIDESPREAD ACROSS THE FA
MONDAY NIGHT INTO TUESDAY. PRECIPITATION WILL THEN TAPER OFF ACROSS
THE FA TUESDAY EVENING. TEMPERATURE PROFILES ARE WARM ENOUGH WITH
THIS SYSTEM THAT PRECIPITATION WILL BE IN THE FORM OF RAIN.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
FLURRIES AND SNOW SHOWERS ARE STILL WIDESPREAD ACROSS THE AREA
EARLY THIS MORNING. WITH CONTINUING WEAK CYCLONIC LOW LEVEL FLOW
AND LINGERING 850 MB MOISTURE...WILL PLAY THE TAFS PRETTY
PESSIMISTIC AND HANG ON TO FLURRIES THROUGH AT LEAST DAYBREAK.
CIGS AND VSBYS WILL GENERALLY REMAIN VFR BUT MAY OCCASIONALLY DROP
INTO MVFR WITH SOME OF THE MORE SIGNIFICANT SNOW SHOWERS. MODELS
ARE TRYING TO INDICATE SOME DRYING TRYING TO WORK IN THROUGH THIS
AFTERNOON SO WILL TRY TO BRING SOME PARTIAL CLEARING LATER
TODAY INTO AT LEAST THE SOUTHWEST.
OUTLOOK...A WINTRY MIX IS EXPECTED THURSDAY NIGHT INTO FRIDAY
MORNING WITH SOME SLEET AND ICE ACCUMULATION LIKELY. IN ADDITION
MVFR CEILINGS AND VISIBILITIES WILL BE LIKELY WITH A PERIOD OF IFR
CONDITIONS POSSIBLE. MVFR CEILINGS MAY CONTINUE THROUGH FRIDAY
NIGHT AND INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...KURZ
NEAR TERM...
SHORT TERM...KURZ
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1243 PM EST WED FEB 20 2013
.SYNOPSIS...
AN ELONGATED AREA OF HIGH PRESSURE WILL RIDGE DOWN FROM CENTRAL
CANADA INTO THURSDAY. A FRONTAL SYSTEM IS EXPECTED TO MOVE EAST
FROM TEXAS THURSDAY AND SHOULD BE EAST OF OUR AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM EST WEDNESDAY...DEWPOINTS CONTINUE TO RUN A LITTLE
LOWER THAN PROGGED OVER THE MOUNTAINS AND FOOTHILLS...OTHERWISE THE
GRIDS ARE IN GOOD SHAPE THIS AFTN.
AS OF 1005 AM EST WEDNESDAY...HIGH CLOUDS WILL INCREASE ACROSS THE
REGION INTO THE AFTERNOON HOURS. ALSO...FLOW ACROSS THE MTNS IS
STRONG ENOUGH TO SET UP A HIGH ALTITUDE MOUNTAIN WAVE WHICH IS ALSO
LIKELY TO KICK OFF AN INCREASING AMOUNT OF LEE SIDE CI/ACC. I/VE
UPPED THE CLOUD COVER IN THE GRIDS THE REST OF THE DAY TO REFLECT
THESE TRENDS.
AS OF 645 AM...TEMPS RANGE FROM THE UPPER 20S TO LOWER 30S ACROSS
THE MTN VALLEYS/ FHILLS/PIEDMONT THIS MORNING...AND SHOULD WARM 5-10
DEGREES BY 15Z. GUSTY WINDS PERSIST ACROSS THE NRN MTNS...MAINLY THE
HIGH ELEVATIONS...SO THE ADVISORY WILL REMAIN IN PLACE FOR NOW.
PREVIOUS DISCUSSION...
DEEP LOW PRESSURE WILL LIFT ACROSS NEW ENGLAND AND THE CANADIAN
MARITIMES DURING THE NEAR TERM...ALLOWING DEEP LAYER RIDGING TO
BUILD INTO MUCH OF THE EASTERN CONUS THROUGH THE PERIOD. THIS WILL
SUPPORT A VERY DRY AIR MASS OVER OUR AREA. THE LATEST RAP SOUNDINGS
INDICATE VERY STRONG WINDS (50-60 KT) THIS MORNING ABOVE 4000 FEET
ACROSS OUR NORTHERN ZONES. HOWEVER...THERE IS ALSO A VERY SHALLOW
MIXED LAYER IN THE MTN VALLEYS WITH A STRONG INVERSION RISING
THROUGH THE CORE OF THE STRONGEST WINDS. IT/S NOT SURPRISING THAT
WHILE THE PEAKS AND RIDGE TOPS OF THE NORTHERN MTNS ARE HOWLING AT
THIS HOUR (50-60 MPH WINDS RECENTLY OBSERVED AT GRANDFATHER
MTN)...THE WINDS ARE RELATIVELY SUBDUED IN THE LOWER ELEVATIONS.
THERE MAY BE A BRIEF PERIOD OF TIME LATER THIS MORNING WHEN THE
MIXING DEEPENS A LITTLE AND STRONGER WIND GUSTS DESCEND INTO THE
VALLEYS...SO THE WIND ADVISORY WILL BE CONTINUED...BUT MAINLY TO
HIGHLIGHT THE HIGHEST ELEVATIONS.
SKY COVER WILL INCREASE A BIT LATER TODAY...AS THE UPPER JET AXIS
LIFTS NORTHEAST FROM THE SOUTHERN PLAINS...ALLOWING CIRRUS TO WAFT
OVER THE AREA. THIS MAY RESULT IN A BRIEF PERIOD OF MOSTLY CLOUDY
SKIES ACROSS THE AREA THIS EVENING. THICKNESSES WILL REMAIN
RELATIVELY LOW UNDER THE AXIS OF THE BROAD UPPER TROUGH...SO MAX
TEMPERATURES ARE EXPECTED TO AVERAGE ABOUT A CATEGORY BELOW NORMAL.
WITH THE DRY AIR MASS AND GOOD RADIATIONAL COOLING CONDITIONS
EXPECTED TONIGHT...MIN TEMPS ARE EXPECTED TO AVERAGE 5-10 DEGREES
BELOW CLIMO.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 2 AM WED...HIGH PRESSURE STILL EXPECTED TO MAINTAIN QUIET
CONDITIONS FOR THE DAYTIME HOURS THU. RIDGE AXIS BEGINS TO SPILL
ACROSS THE APPALACHIAN CHAIN AS THE DAY PROGRESSES...SETTING THE
STAGE FOR CAD THAT WILL DEVELOP THU NIGHT. WARM FRONT WILL EDGE
NORTHEAST TOWARDS OUR AREA FROM THE GULF COAST THU BUT WON/T QUITE
MAKE IT BY 00Z. SKIES SHOULD BE MOSTLY CLEAR IN THE MORNING BUT
CLOUDS WILL INCREASE IN THE AFTERNOON AS MOISTURE ADVANCES NORTHWARD
AHEAD OF THE FRONT. HIGHS LOOK TO BE SLIGHTLY TO A FEW DEGREES ABOVE
NORMAL NONETHELESS.
THE ACTION BEGINS SHORTLY AFTER 00Z FRI AS THE WARM FRONT LIFTS INTO
THE SOUTHWEST ZONES OF OUR CWFA. ISENTROPIC LIFT WILL BE ENHANCED BY
STRONG LOW LEVEL JET /WITH BETTER WINDS AT 700 THAN 850MB/. THE
PRECIP WILL FALL INTO THE INITIALLY DRY COLD AIR NEAR THE SURFACE AND
THAT WILL BEGIN TO ENTRENCH THE WEDGE THAT OFFERS BIG CHALLENGES FOR
THE FORECAST THROUGH MOST OF THE SHORT TERM PERIOD. QPF FOCUSES ALONG
THE BOUNDARY OF THE WEDGE IN THE SOUTHWEST MTNS SOUTHWARD INTO THE
SAVANNAH RIVER VALLEY. PWAT VALUES /SREF MEAN AROUND 1 INCH/ ARE WELL
ABOVE NORMAL PER RAOB CLIMATOLOGY AT KFFC/KGSO BUT NOT OFF THE
CHARTS. I PREFER THE QPF OFFERED BY THE GFS WHICH IS A BIT MORE
MODEST THAN THE NAM AND BETTER MATCHES EXPECTED PRECIP DISTRIBUTION
GIVEN THE SETUP. RAW MODEL TEMPS FROM THE NAM HOWEVER BEST REFLECT
THE CAD. ALSO OF NOTE THU NIGHT ARE PRESENCE OF SLIGHTLY UNSTABLE
PARCELS LIFTED FROM ABOVE THE SFC INVERSION...MOSTLY OVER THE
MOUNTAINS. WILL INCLUDE SCHC THUNDER THERE.
ISENTROPIC LIFT CONTINUES INTO FRIDAY. WIND SPEEDS DO DIMINISH AND
SOME DRIER AIR WORKS IN ALOFT FROM THE SOUTHWEST WHICH WILL CUT DOWN
ON PRECIP PRODUCTION. LIFT REMAINS IN SOME FASHION THROUGHOUT THE DAY
SO I BELIEVE THE UNBROKEN PERIOD OF LIGHT MODEL QPF...BUT
ACCUMULATION WILL BE SMALL. THE COLD WEDGE WILL STILL BE IN PLACE SO
MAX TEMPS WILL STRUGGLE TO GET OUT OF THE 30S OVER MUCH OF THE
CWA...EXCEPT IN THE SOUTHWEST ON ITS FRINGE. THE GFS/NAM/EC ALL HOLD
ONTO THE WEDGE INTO SATURDAY EVENING WHICH IS CERTAINLY NOT TOO LATE.
COLD FRONT EXTENDING FROM LOW OVER THE GREAT LAKES BRINGS THE FORCING
FOR A SECOND WAVE OF PRECIP FRIDAY NIGHT.
COLD FROPA POTENTIALLY MAY SCOUR OUT THE WEDGE SHORTLY AFTER DAYBREAK
SATURDAY. THIS IS ONE RECOGNIZED METHOD OF CAD EROSION PER CSTAR
RESEARCH BUT SAME RESEARCH INDICATES MODELS STILL MAY ERODE WEDGES
TOO QUICKLY. GFS/EC DON/T SHOW 925MB COLD ADVECTION GETTING GOING
UNTIL SATURDAY AFTERNOON SO I BELIEVE COOL HIGH TEMPS WILL BE FELT
SATURDAY AS WELL...WILL GO ON LOW END OF GUIDANCE. WHATEVER VESTIGE
OF THE WEDGE THAT THE FROPA IS NOT ABLE TO REMOVE WILL LIKELY BE
TAKEN OUT BY DEVELOPING COASTAL LOW SAT AFTN SO I THINK HIGHS WILL BE
ABLE TO RISE ABOVE THOSE ON FRIDAY.
SOME PRECIP WILL BE POSSIBLE SAT NIGHT WITH WRAPAROUND MOISTURE ON
THE BACK SIDE OF THE AFOREMENTIONED COASTAL LOW...MAINLY OVER THE NC
ZONES. NORTHWEST WINDS IN THE NRN MOUNTAINS WILL ENHANCE CHANCES/QPF
BUT THE MOISTURE IS SOMEWHAT SHALLOW AND ACCUMULATIONS REMAIN LIGHT.
THE ENTIRE AREA LOOKS TO BE DRY BY AROUND 06Z SUNDAY...WITH A
CLEARING TREND BEGINNING THEN.
AS FAR AS WINTER WX POTENTIAL...THE STRENGTH OF THE WARM NOSE IN THE
WARM FLOW OVER THE WEDGE WILL COMPLETELY MELT ANY SNOW GENERATED
ALOFT DURING MOST OF THE EVENT...PUTTING PTYPE DETERMINATION SOLELY
ON SFC TEMP. HOWEVER IN THE MORE SHALLOW WARM AIR ON THE LEADING EDGE
OF THE FRONT THU NIGHT...ONLY PARTIAL MELTING WOULD BE POSSIBLE WHICH
GIVEN MOIST CRYSTAL GROWTH REGION WOULD ALLOW SLEET AT THE SFC.
HIGHER ELEVATIONS MIGHT BE ABOVE THE WARM NOSE AND GET SNOW EARLY ON
AS WELL. RELATIVELY HIGH PRECIP RATES MEAN THE HIGHEST ELEVATIONS
COULD SEE UP TO A COUPLE INCHES OF SNOW AND SLEET. POPULATED AREAS
ARE EXPECTED TO GET LESS THAN AN INCH. FREEZING RAIN WILL DOMINATE
LATER THU NIGHT ONCE TOTAL MELTING OCCURS...WITH LESS THAN A QUARTER
INCH OF ACCUMULATION.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 250 AM EST WEDNESDAY...THIS PERIOD OF THE FORECAST BEGINS AT
12Z SUNDAY WITH HIGH PRESSURE CENTERED OVER TENNESSEE AND DRY
WEATHER FOR OUR AREA AT LEAST UNTIL LATE SUNDAY NIGHT. A NICE
SEASONABLY MILD DAY ON SUNDAY.
THIS HIGH MOVES TO BE CENTERED OVER PENNSYLVANIA AT 12Z MONDAY AND
BECOMES A COOLING HIGH FOR OUR AREA. IT IS INTERESTING THAT THE
BUFKIT GFS HAS A QUITE COOL SCENARIO FOR OUR REGION ON MONDAY WITH
MOISTURE BEING PULLED INTO OUR AREA AHEAD OF THE NEXT FROM
APPROACHING FROM THE WEST. THIS RUN OF BUFKIT ACTUALLY HAS SNOW
FALLING IN THE NRN MTNS MONDAY MORNING AND THEN FREEZING RAIN UNTIL
EVENING WHEN IT CHANGES OVER TO RAIN. HKY AND CLT EVEN HAS MIXED
SLEET AND SNOW THROUGH MONDAY MORNING ON THIS BUFKIT RUN. THAT
BEING SAID...SEEMS TOO COLD AND UNREASONABLE AT THIS POINT AND GOING
WITH ALMOST ALL RAIN WITH THIS EVENT. THE CUT OFF LOW WILL MOVE
SLOWLY NE ACROSS THE CENTRAL MISSISSIPPI VALLEY MONDAY AS THE FRONT
CROSSES THE SOUTHEAST TOWARD OUR AREA. 925MB UPSLOPE FLOW WILL BE 10
TO 15 KTS EARLY MONDAY THEN CHANGE TO A LESS FAVORABLE EAST WIND
LATER MONDAY. MOST FORCING WILL BE SOUTH AND NORTH OF OUR AREA AND
RAINFALL AMOUNTS WILL BE RATHER LOW FOR THE EVENT. THE BEST TIME FOR
A MORE PERSISTENT RAIN IS LATE MONDAY NIGHT. THE PERSISTENT LOW WILL
MOVE NORTH FROM ILLINOIS ON TUESDAY CROSSING THE GREAT LAKES
WEDNESDAY. WE WILL BE UNDER THE INFLUENCE OF WEAK HIGH PRESSURE LATE
TUESDAY AND TUESDAY NIGHT.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS THROUGH THE PERIOD. WINDS
WILL BE NORTHWEST AT KAVL AND KHKY THIS AFTN...AND SOUTHWEST TO THE
EAST OF A LEE TROUGH AT THE REMAINING SITES. WINDS WILL TURN OUT OF
THE NORTH ACROSS THE REGION DURING THE EVENING HOURS...THEN
GRADUALLY VEER AROUND TO THE NORTHEAST OVERNIGHT. ONLY HIGH CLOUDS
ARE EXPECTED OVER THE NEXT 24 HOURS.
OUTLOOK...ANOTHER WEATHER SYSTEM WILL BRING MORE PRECIPITATION AND
RESTRICTIONS ON THURSDAY NIGHT AND FRIDAY. THE PATTERN WILL REMAIN
UNSETTLED AND CONDUCIVE TO PERIODS OF RAIN/RESTRICTIONS THROUGH THE
EARLY PART OF THE WEEKEND...WITH CLEARING POSSIBLE BY SUNDAY.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
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
&&
.FIRE WEATHER...
DRY AND BREEZY TO WINDY CONDITIONS ARE EXPECTED TODAY. HOWEVER...
FUELS SHOULD BE FAIRLY MOIST FROM RECENT RAINFALL. THIS WILL KEEP
FIRE DANGER LOW.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL/MCAVOY
SHORT TERM...WIMBERLEY
LONG TERM...DEO
AVIATION...MCAVOY
FIRE WEATHER...WIMBERLY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1007 AM EST WED FEB 20 2013
.SYNOPSIS...
AN ELONGATED AREA OF HIGH PRESSURE WILL RIDGE DOWN FROM CENTRAL
CANADA INTO THURSDAY. A FRONTAL SYSTEM IS EXPECTED TO MOVE EAST
FROM TEXAS THURSDAY AND SHOULD BE EAST OF OUR AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EST WEDNESDAY...HIGH CLOUDS WILL INCREASE ACROSS THE
REGION INTO THE AFTERNOON HOURS. ALSO...FLOW ACROSS THE MTNS IS
STRONG ENOUGH TO SET UP A HIGH ALTITUDE MOUNTAIN WAVE WHICH IS ALSO
LIKELY TO KICK OFF AN INCREASING AMOUNT OF LEE SIDE CI/ACC. I/VE
UPPED THE CLOUD COVER IN THE GRIDS THE REST OF THE DAY TO REFLECT
THESE TRENDS.
AS OF 645 AM...TEMPS RANGE FROM THE UPPER 20S TO LOWER 30S ACROSS
THE MTN VALLEYS/ FHILLS/PIEDMONT THIS MORNING...AND SHOULD WARM 5-10
DEGREES BY 15Z. GUSTY WINDS PERSIST ACROSS THE NRN MTNS...MAINLY THE
HIGH ELEVATIONS...SO THE ADVISORY WILL REMAIN IN PLACE FOR NOW.
PREVIOUS DISCUSSION...
DEEP LOW PRESSURE WILL LIFT ACROSS NEW ENGLAND AND THE CANADIAN
MARITIMES DURING THE NEAR TERM...ALLOWING DEEP LAYER RIDGING TO
BUILD INTO MUCH OF THE EASTERN CONUS THROUGH THE PERIOD. THIS WILL
SUPPORT A VERY DRY AIR MASS OVER OUR AREA. THE LATEST RAP SOUNDINGS
INDICATE VERY STRONG WINDS (50-60 KT) THIS MORNING ABOVE 4000 FEET
ACROSS OUR NORTHERN ZONES. HOWEVER...THERE IS ALSO A VERY SHALLOW
MIXED LAYER IN THE MTN VALLEYS WITH A STRONG INVERSION RISING
THROUGH THE CORE OF THE STRONGEST WINDS. IT/S NOT SURPRISING THAT
WHILE THE PEAKS AND RIDGE TOPS OF THE NORTHERN MTNS ARE HOWLING AT
THIS HOUR (50-60 MPH WINDS RECENTLY OBSERVED AT GRANDFATHER
MTN)...THE WINDS ARE RELATIVELY SUBDUED IN THE LOWER ELEVATIONS.
THERE MAY BE A BRIEF PERIOD OF TIME LATER THIS MORNING WHEN THE
MIXING DEEPENS A LITTLE AND STRONGER WIND GUSTS DESCEND INTO THE
VALLEYS...SO THE WIND ADVISORY WILL BE CONTINUED...BUT MAINLY TO
HIGHLIGHT THE HIGHEST ELEVATIONS.
SKY COVER WILL INCREASE A BIT LATER TODAY...AS THE UPPER JET AXIS
LIFTS NORTHEAST FROM THE SOUTHERN PLAINS...ALLOWING CIRRUS TO WAFT
OVER THE AREA. THIS MAY RESULT IN A BRIEF PERIOD OF MOSTLY CLOUDY
SKIES ACROSS THE AREA THIS EVENING. THICKNESSES WILL REMAIN
RELATIVELY LOW UNDER THE AXIS OF THE BROAD UPPER TROUGH...SO MAX
TEMPERATURES ARE EXPECTED TO AVERAGE ABOUT A CATEGORY BELOW NORMAL.
WITH THE DRY AIR MASS AND GOOD RADIATIONAL COOLING CONDITIONS
EXPECTED TONIGHT...MIN TEMPS ARE EXPECTED TO AVERAGE 5-10 DEGREES
BELOW CLIMO.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 2 AM WED...HIGH PRESSURE STILL EXPECTED TO MAINTAIN QUIET
CONDITIONS FOR THE DAYTIME HOURS THU. RIDGE AXIS BEGINS TO SPILL
ACROSS THE APPALACHIAN CHAIN AS THE DAY PROGRESSES...SETTING THE
STAGE FOR CAD THAT WILL DEVELOP THU NIGHT. WARM FRONT WILL EDGE
NORTHEAST TOWARDS OUR AREA FROM THE GULF COAST THU BUT WON/T QUITE
MAKE IT BY 00Z. SKIES SHOULD BE MOSTLY CLEAR IN THE MORNING BUT
CLOUDS WILL INCREASE IN THE AFTERNOON AS MOISTURE ADVANCES NORTHWARD
AHEAD OF THE FRONT. HIGHS LOOK TO BE SLIGHTLY TO A FEW DEGREES ABOVE
NORMAL NONETHELESS.
THE ACTION BEGINS SHORTLY AFTER 00Z FRI AS THE WARM FRONT LIFTS INTO
THE SOUTHWEST ZONES OF OUR CWFA. ISENTROPIC LIFT WILL BE ENHANCED BY
STRONG LOW LEVEL JET /WITH BETTER WINDS AT 700 THAN 850MB/. THE
PRECIP WILL FALL INTO THE INITIALLY DRY COLD AIR NEAR THE SURFACE AND
THAT WILL BEGIN TO ENTRENCH THE WEDGE THAT OFFERS BIG CHALLENGES FOR
THE FORECAST THROUGH MOST OF THE SHORT TERM PERIOD. QPF FOCUSES ALONG
THE BOUNDARY OF THE WEDGE IN THE SOUTHWEST MTNS SOUTHWARD INTO THE
SAVANNAH RIVER VALLEY. PWAT VALUES /SREF MEAN AROUND 1 INCH/ ARE WELL
ABOVE NORMAL PER RAOB CLIMATOLOGY AT KFFC/KGSO BUT NOT OFF THE
CHARTS. I PREFER THE QPF OFFERED BY THE GFS WHICH IS A BIT MORE
MODEST THAN THE NAM AND BETTER MATCHES EXPECTED PRECIP DISTRIBUTION
GIVEN THE SETUP. RAW MODEL TEMPS FROM THE NAM HOWEVER BEST REFLECT
THE CAD. ALSO OF NOTE THU NIGHT ARE PRESENCE OF SLIGHTLY UNSTABLE
PARCELS LIFTED FROM ABOVE THE SFC INVERSION...MOSTLY OVER THE
MOUNTAINS. WILL INCLUDE SCHC THUNDER THERE.
ISENTROPIC LIFT CONTINUES INTO FRIDAY. WIND SPEEDS DO DIMINISH AND
SOME DRIER AIR WORKS IN ALOFT FROM THE SOUTHWEST WHICH WILL CUT DOWN
ON PRECIP PRODUCTION. LIFT REMAINS IN SOME FASHION THROUGHOUT THE DAY
SO I BELIEVE THE UNBROKEN PERIOD OF LIGHT MODEL QPF...BUT
ACCUMULATION WILL BE SMALL. THE COLD WEDGE WILL STILL BE IN PLACE SO
MAX TEMPS WILL STRUGGLE TO GET OUT OF THE 30S OVER MUCH OF THE
CWA...EXCEPT IN THE SOUTHWEST ON ITS FRINGE. THE GFS/NAM/EC ALL HOLD
ONTO THE WEDGE INTO SATURDAY EVENING WHICH IS CERTAINLY NOT TOO LATE.
COLD FRONT EXTENDING FROM LOW OVER THE GREAT LAKES BRINGS THE FORCING
FOR A SECOND WAVE OF PRECIP FRIDAY NIGHT.
COLD FROPA POTENTIALLY MAY SCOUR OUT THE WEDGE SHORTLY AFTER DAYBREAK
SATURDAY. THIS IS ONE RECOGNIZED METHOD OF CAD EROSION PER CSTAR
RESEARCH BUT SAME RESEARCH INDICATES MODELS STILL MAY ERODE WEDGES
TOO QUICKLY. GFS/EC DON/T SHOW 925MB COLD ADVECTION GETTING GOING
UNTIL SATURDAY AFTERNOON SO I BELIEVE COOL HIGH TEMPS WILL BE FELT
SATURDAY AS WELL...WILL GO ON LOW END OF GUIDANCE. WHATEVER VESTIGE
OF THE WEDGE THAT THE FROPA IS NOT ABLE TO REMOVE WILL LIKELY BE
TAKEN OUT BY DEVELOPING COASTAL LOW SAT AFTN SO I THINK HIGHS WILL BE
ABLE TO RISE ABOVE THOSE ON FRIDAY.
SOME PRECIP WILL BE POSSIBLE SAT NIGHT WITH WRAPAROUND MOISTURE ON
THE BACK SIDE OF THE AFOREMENTIONED COASTAL LOW...MAINLY OVER THE NC
ZONES. NORTHWEST WINDS IN THE NRN MOUNTAINS WILL ENHANCE CHANCES/QPF
BUT THE MOISTURE IS SOMEWHAT SHALLOW AND ACCUMULATIONS REMAIN LIGHT.
THE ENTIRE AREA LOOKS TO BE DRY BY AROUND 06Z SUNDAY...WITH A
CLEARING TREND BEGINNING THEN.
AS FAR AS WINTER WX POTENTIAL...THE STRENGTH OF THE WARM NOSE IN THE
WARM FLOW OVER THE WEDGE WILL COMPLETELY MELT ANY SNOW GENERATED
ALOFT DURING MOST OF THE EVENT...PUTTING PTYPE DETERMINATION SOLELY
ON SFC TEMP. HOWEVER IN THE MORE SHALLOW WARM AIR ON THE LEADING EDGE
OF THE FRONT THU NIGHT...ONLY PARTIAL MELTING WOULD BE POSSIBLE WHICH
GIVEN MOIST CRYSTAL GROWTH REGION WOULD ALLOW SLEET AT THE SFC.
HIGHER ELEVATIONS MIGHT BE ABOVE THE WARM NOSE AND GET SNOW EARLY ON
AS WELL. RELATIVELY HIGH PRECIP RATES MEAN THE HIGHEST ELEVATIONS
COULD SEE UP TO A COUPLE INCHES OF SNOW AND SLEET. POPULATED AREAS
ARE EXPECTED TO GET LESS THAN AN INCH. FREEZING RAIN WILL DOMINATE
LATER THU NIGHT ONCE TOTAL MELTING OCCURS...WITH LESS THAN A QUARTER
INCH OF ACCUMULATION.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 250 AM EST WEDNESDAY...THIS PERIOD OF THE FORECAST BEGINS AT
12Z SUNDAY WITH HIGH PRESSURE CENTERED OVER TENNESSEE AND DRY
WEATHER FOR OUR AREA AT LEAST UNTIL LATE SUNDAY NIGHT. A NICE
SEASONABLY MILD DAY ON SUNDAY.
THIS HIGH MOVES TO BE CENTERED OVER PENNSYLVANIA AT 12Z MONDAY AND
BECOMES A COOLING HIGH FOR OUR AREA. IT IS INTERESTING THAT THE
BUFKIT GFS HAS A QUITE COOL SCENARIO FOR OUR REGION ON MONDAY WITH
MOISTURE BEING PULLED INTO OUR AREA AHEAD OF THE NEXT FROM
APPROACHING FROM THE WEST. THIS RUN OF BUFKIT ACTUALLY HAS SNOW
FALLING IN THE NRN MTNS MONDAY MORNING AND THEN FREEZING RAIN UNTIL
EVENING WHEN IT CHANGES OVER TO RAIN. HKY AND CLT EVEN HAS MIXED
SLEET AND SNOW THROUGH MONDAY MORNING ON THIS BUFKIT RUN. THAT
BEING SAID...SEEMS TOO COLD AND UNREASONABLE AT THIS POINT AND GOING
WITH ALMOST ALL RAIN WITH THIS EVENT. THE CUT OFF LOW WILL MOVE
SLOWLY NE ACROSS THE CENTRAL MISSISSIPPI VALLEY MONDAY AS THE FRONT
CROSSES THE SOUTHEAST TOWARD OUR AREA. 925MB UPSLOPE FLOW WILL BE 10
TO 15 KTS EARLY MONDAY THEN CHANGE TO A LESS FAVORABLE EAST WIND
LATER MONDAY. MOST FORCING WILL BE SOUTH AND NORTH OF OUR AREA AND
RAINFALL AMOUNTS WILL BE RATHER LOW FOR THE EVENT. THE BEST TIME FOR
A MORE PERSISTENT RAIN IS LATE MONDAY NIGHT. THE PERSISTENT LOW WILL
MOVE NORTH FROM ILLINOIS ON TUESDAY CROSSING THE GREAT LAKES
WEDNESDAY. WE WILL BE UNDER THE INFLUENCE OF WEAK HIGH PRESSURE LATE
TUESDAY AND TUESDAY NIGHT.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...A VERY DRY AIR MASS WILL PROMOTE VFR
CONDITIONS THROUGH THE PERIOD...WITH THE ONLY CLOUD COVER BEING
PROVIDED BY PERIODS OF SCT/BKN HIGH CLOUDS. CALM OR LGT/VRBL WINDS
WILL INCREASE OUT OF SW LATER THIS MORNING AT THE UPSTATE SC
TERMINALS...AS A LEE TROUGH TAKES SHAPE. KCLT WINDS SHOULD BE A
LITTLE NORTH OF DUE WEST THIS MORNING...BUT POSSIBLY BECOME SOUTH OF
DUE WEST THIS AFTERNOON IN RESPONSE TO THE LEE TROUGH. SPEEDS SHOULD
BE IN THE 5-8 KT FROM LATE MORNING THROUGH THE AFTERNOON.
MEANWHILE...KAVL WILL CONTINUE TO SEE N/NW WINDS OF 10-15 KT...WITH
SOME GUSTS IN THE LOWER 20S POSSIBLE LATER THIS MORNING.
OUTLOOK...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THURSDAY
WITH VFR CONDITIONS. ANOTHER WEATHER SYSTEM WILL BRING MORE
PRECIPITATION AND RESTRICTIONS ON THURSDAY NIGHT AND FRIDAY. THE
PATTERN WILL REMAIN UNSETTLED AND CONDUCIVE TO PERIODS OF
RAIN/RESTRICTIONS THROUGH THE EARLY PART OF THE WEEKEND...WITH
CLEARING POSSIBLE BY SUNDAY.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-15Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
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
&&
.FIRE WEATHER...
DRY AND BREEZY TO WINDY CONDITIONS ARE EXPECTED TODAY. HOWEVER...
FUELS SHOULD BE FAIRLY MOIST FROM RECENT RAINFALL. THIS WILL KEEP
FIRE DANGER LOW.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WIND ADVISORY UNTIL NOON EST TODAY FOR NCZ033-049-050-501-503-
505.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL/MCAVOY
SHORT TERM...WIMBERLEY
LONG TERM...DEO
AVIATION...JDL
FIRE WEATHER...WIMBERLY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
646 AM EST WED FEB 20 2013
.SYNOPSIS...
AN ELONGATED AREA OF HIGH PRESSURE WILL RIDGE DOWN FROM CENTRAL
CANADA INTO THURSDAY. A FRONTAL SYSTEM IS EXPECTED TO MOVE EAST
FROM TEXAS THURSDAY AND SHOULD BE EAST OF OUR AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TEMPS RANGE FROM THE UPPER 20S TO LOWER 30S ACROSS THE MTN VALLEYS/
FHILLS/PIEDMONT THIS MORNING...AND SHOULD WARM 5-10 DEGREES BY 15Z.
GUSTY WINDS PERSIST ACROSS THE NRN MTNS...MAINLY THE HIGH
ELEVATIONS...SO THE ADVISORY WILL REMAIN IN PLACE FOR NOW.
PREVIOUS DISCUSSION...
DEEP LOW PRESSURE WILL LIFT ACROSS NEW ENGLAND AND THE CANADIAN
MARITIMES DURING THE NEAR TERM...ALLOWING DEEP LAYER RIDGING TO
BUILD INTO MUCH OF THE EASTERN CONUS THROUGH THE PERIOD. THIS WILL
SUPPORT A VERY DRY AIR MASS OVER OUR AREA. THE LATEST RAP SOUNDINGS
INDICATE VERY STRONG WINDS (50-60 KT) THIS MORNING ABOVE 4000 FEET
ACROSS OUR NORTHERN ZONES. HOWEVER...THERE IS ALSO A VERY SHALLOW
MIXED LAYER IN THE MTN VALLEYS WITH A STRONG INVERSION RISING
THROUGH THE CORE OF THE STRONGEST WINDS. IT/S NOT SURPRISING THAT
WHILE THE PEAKS AND RIDGE TOPS OF THE NORTHERN MTNS ARE HOWLING AT
THIS HOUR (50-60 MPH WINDS RECENTLY OBSERVED AT GRANDFATHER
MTN)...THE WINDS ARE RELATIVELY SUBDUED IN THE LOWER ELEVATIONS.
THERE MAY BE A BRIEF PERIOD OF TIME LATER THIS MORNING WHEN THE
MIXING DEEPENS A LITTLE AND STRONGER WIND GUSTS DESCEND INTO THE
VALLEYS...SO THE WIND ADVISORY WILL BE CONTINUED...BUT MAINLY TO
HIGHLIGHT THE HIGHEST ELEVATIONS.
SKY COVER WILL INCREASE A BIT LATER TODAY...AS THE UPPER JET AXIS
LIFTS NORTHEAST FROM THE SOUTHERN PLAINS...ALLOWING CIRRUS TO WAFT
OVER THE AREA. THIS MAY RESULT IN A BRIEF PERIOD OF MOSTLY CLOUDY
SKIES ACROSS THE AREA THIS EVENING. THICKNESSES WILL REMAIN
RELATIVELY LOW UNDER THE AXIS OF THE BROAD UPPER TROUGH...SO MAX
TEMPERATURES ARE EXPECTED TO AVERAGE ABOUT A CATEGORY BELOW NORMAL.
WITH THE DRY AIR MASS AND GOOD RADIATIONAL COOLING CONDITIONS
EXPECTED TONIGHT...MIN TEMPS ARE EXPECTED TO AVERAGE 5-10 DEGREES
BELOW CLIMO.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 2 AM WED...HIGH PRESSURE STILL EXPECTED TO MAINTAIN QUIET
CONDITIONS FOR THE DAYTIME HOURS THU. RIDGE AXIS BEGINS TO SPILL
ACROSS THE APPALACHIAN CHAIN AS THE DAY PROGRESSES...SETTING THE
STAGE FOR CAD THAT WILL DEVELOP THU NIGHT. WARM FRONT WILL EDGE
NORTHEAST TOWARDS OUR AREA FROM THE GULF COAST THU BUT WON/T QUITE
MAKE IT BY 00Z. SKIES SHOULD BE MOSTLY CLEAR IN THE MORNING BUT
CLOUDS WILL INCREASE IN THE AFTERNOON AS MOISTURE ADVANCES NORTHWARD
AHEAD OF THE FRONT. HIGHS LOOK TO BE SLIGHTLY TO A FEW DEGREES ABOVE
NORMAL NONETHELESS.
THE ACTION BEGINS SHORTLY AFTER 00Z FRI AS THE WARM FRONT LIFTS INTO
THE SOUTHWEST ZONES OF OUR CWFA. ISENTROPIC LIFT WILL BE ENHANCED BY
STRONG LOW LEVEL JET /WITH BETTER WINDS AT 700 THAN 850MB/. THE
PRECIP WILL FALL INTO THE INITIALLY DRY COLD AIR NEAR THE SURFACE AND
THAT WILL BEGIN TO ENTRENCH THE WEDGE THAT OFFERS BIG CHALLENGES FOR
THE FORECAST THROUGH MOST OF THE SHORT TERM PERIOD. QPF FOCUSES ALONG
THE BOUNDARY OF THE WEDGE IN THE SOUTHWEST MTNS SOUTHWARD INTO THE
SAVANNAH RIVER VALLEY. PWAT VALUES /SREF MEAN AROUND 1 INCH/ ARE WELL
ABOVE NORMAL PER RAOB CLIMATOLOGY AT KFFC/KGSO BUT NOT OFF THE
CHARTS. I PREFER THE QPF OFFERED BY THE GFS WHICH IS A BIT MORE
MODEST THAN THE NAM AND BETTER MATCHES EXPECTED PRECIP DISTRIBUTION
GIVEN THE SETUP. RAW MODEL TEMPS FROM THE NAM HOWEVER BEST REFLECT
THE CAD. ALSO OF NOTE THU NIGHT ARE PRESENCE OF SLIGHTLY UNSTABLE
PARCELS LIFTED FROM ABOVE THE SFC INVERSION...MOSTLY OVER THE
MOUNTAINS. WILL INCLUDE SCHC THUNDER THERE.
ISENTROPIC LIFT CONTINUES INTO FRIDAY. WIND SPEEDS DO DIMINISH AND
SOME DRIER AIR WORKS IN ALOFT FROM THE SOUTHWEST WHICH WILL CUT DOWN
ON PRECIP PRODUCTION. LIFT REMAINS IN SOME FASHION THROUGHOUT THE DAY
SO I BELIEVE THE UNBROKEN PERIOD OF LIGHT MODEL QPF...BUT
ACCUMULATION WILL BE SMALL. THE COLD WEDGE WILL STILL BE IN PLACE SO
MAX TEMPS WILL STRUGGLE TO GET OUT OF THE 30S OVER MUCH OF THE
CWA...EXCEPT IN THE SOUTHWEST ON ITS FRINGE. THE GFS/NAM/EC ALL HOLD
ONTO THE WEDGE INTO SATURDAY EVENING WHICH IS CERTAINLY NOT TOO LATE.
COLD FRONT EXTENDING FROM LOW OVER THE GREAT LAKES BRINGS THE FORCING
FOR A SECOND WAVE OF PRECIP FRIDAY NIGHT.
COLD FROPA POTENTIALLY MAY SCOUR OUT THE WEDGE SHORTLY AFTER DAYBREAK
SATURDAY. THIS IS ONE RECOGNIZED METHOD OF CAD EROSION PER CSTAR
RESEARCH BUT SAME RESEARCH INDICATES MODELS STILL MAY ERODE WEDGES
TOO QUICKLY. GFS/EC DON/T SHOW 925MB COLD ADVECTION GETTING GOING
UNTIL SATURDAY AFTERNOON SO I BELIEVE COOL HIGH TEMPS WILL BE FELT
SATURDAY AS WELL...WILL GO ON LOW END OF GUIDANCE. WHATEVER VESTIGE
OF THE WEDGE THAT THE FROPA IS NOT ABLE TO REMOVE WILL LIKELY BE
TAKEN OUT BY DEVELOPING COASTAL LOW SAT AFTN SO I THINK HIGHS WILL BE
ABLE TO RISE ABOVE THOSE ON FRIDAY.
SOME PRECIP WILL BE POSSIBLE SAT NIGHT WITH WRAPAROUND MOISTURE ON
THE BACK SIDE OF THE AFOREMENTIONED COASTAL LOW...MAINLY OVER THE NC
ZONES. NORTHWEST WINDS IN THE NRN MOUNTAINS WILL ENHANCE CHANCES/QPF
BUT THE MOISTURE IS SOMEWHAT SHALLOW AND ACCUMULATIONS REMAIN LIGHT.
THE ENTIRE AREA LOOKS TO BE DRY BY AROUND 06Z SUNDAY...WITH A
CLEARING TREND BEGINNING THEN.
AS FAR AS WINTER WX POTENTIAL...THE STRENGTH OF THE WARM NOSE IN THE
WARM FLOW OVER THE WEDGE WILL COMPLETELY MELT ANY SNOW GENERATED
ALOFT DURING MOST OF THE EVENT...PUTTING PTYPE DETERMINATION SOLELY
ON SFC TEMP. HOWEVER IN THE MORE SHALLOW WARM AIR ON THE LEADING EDGE
OF THE FRONT THU NIGHT...ONLY PARTIAL MELTING WOULD BE POSSIBLE WHICH
GIVEN MOIST CRYSTAL GROWTH REGION WOULD ALLOW SLEET AT THE SFC.
HIGHER ELEVATIONS MIGHT BE ABOVE THE WARM NOSE AND GET SNOW EARLY ON
AS WELL. RELATIVELY HIGH PRECIP RATES MEAN THE HIGHEST ELEVATIONS
COULD SEE UP TO A COUPLE INCHES OF SNOW AND SLEET. POPULATED AREAS
ARE EXPECTED TO GET LESS THAN AN INCH. FREEZING RAIN WILL DOMINATE
LATER THU NIGHT ONCE TOTAL MELTING OCCURS...WITH LESS THAN A QUARTER
INCH OF ACCUMULATION.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 250 AM EST WEDNESDAY...THIS PERIOD OF THE FORECAST BEGINS AT
12Z SUNDAY WITH HIGH PRESSURE CENTERED OVER TENNESSEE AND DRY
WEATHER FOR OUR AREA AT LEAST UNTIL LATE SUNDAY NIGHT. A NICE
SEASONABLY MILD DAY ON SUNDAY.
THIS HIGH MOVES TO BE CENTERED OVER PENNSYLVANIA AT 12Z MONDAY AND
BECOMES A COOLING HIGH FOR OUR AREA. IT IS INTERESTING THAT THE
BUFKIT GFS HAS A QUITE COOL SCENARIO FOR OUR REGION ON MONDAY WITH
MOISTURE BEING PULLED INTO OUR AREA AHEAD OF THE NEXT FROM
APPROACHING FROM THE WEST. THIS RUN OF BUFKIT ACTUALLY HAS SNOW
FALLING IN THE NRN MTNS MONDAY MORNING AND THEN FREEZING RAIN UNTIL
EVENING WHEN IT CHANGES OVER TO RAIN. HKY AND CLT EVEN HAS MIXED
SLEET AND SNOW THROUGH MONDAY MORNING ON THIS BUFKIT RUN. THAT
BEING SAID...SEEMS TOO COLD AND UNREASONABLE AT THIS POINT AND GOING
WITH ALMOST ALL RAIN WITH THIS EVENT. THE CUT OFF LOW WILL MOVE
SLOWLY NE ACROSS THE CENTRAL MISSISSIPPI VALLEY MONDAY AS THE FRONT
CROSSES THE SOUTHEAST TOWARD OUR AREA. 925MB UPSLOPE FLOW WILL BE 10
TO 15 KTS EARLY MONDAY THEN CHANGE TO A LESS FAVORABLE EAST WIND
LATER MONDAY. MOST FORCING WILL BE SOUTH AND NORTH OF OUR AREA AND
RAINFALL AMOUNTS WILL BE RATHER LOW FOR THE EVENT. THE BEST TIME FOR
A MORE PERSISTENT RAIN IS LATE MONDAY NIGHT. THE PERSISTENT LOW WILL
MOVE NORTH FROM ILLINOIS ON TUESDAY CROSSING THE GREAT LAKES
WEDNESDAY. WE WILL BE UNDER THE INFLUENCE OF WEAK HIGH PRESSURE LATE
TUESDAY AND TUESDAY NIGHT.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...A VERY DRY AIR MASS WILL PROMOTE VFR
CONDITIONS THROUGH THE PERIOD...WITH THE ONLY CLOUD COVER BEING
PROVIDED BY PERIODS OF SCT/BKN HIGH CLOUDS. CALM OR LGT/VRBL WINDS
WILL INCREASE OUT OF SW LATER THIS MORNING AT THE UPSTATE SC
TERMINALS...AS A LEE TROUGH TAKES SHAPE. KCLT WINDS SHOULD BE A
LITTLE NORTH OF DUE WEST THIS MORNING...BUT POSSIBLY BECOME SOUTH OF
DUE WEST THIS AFTERNOON IN RESPONSE TO THE LEE TROUGH. SPEEDS SHOULD
BE IN THE 5-8 KT FROM LATE MORNING THROUGH THE AFTERNOON.
MEANWHILE...KAVL WILL CONTINUE TO SEE N/NW WINDS OF 10-15 KT...WITH
SOME GUSTS IN THE LOWER 20S POSSIBLE LATER THIS MORNING.
OUTLOOK...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THURSDAY
WITH VFR CONDITIONS. ANOTHER WEATHER SYSTEM WILL BRING MORE
PRECIPITATION AND RESTRICTIONS ON THURSDAY NIGHT AND FRIDAY. THE
PATTERN WILL REMAIN UNSETTLED AND CONDUCIVE TO PERIODS OF
RAIN/RESTRICTIONS THROUGH THE EARLY PART OF THE WEEKEND...WITH
CLEARING POSSIBLE BY SUNDAY.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
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
&&
.FIRE WEATHER...
DRY AND BREEZY TO WINDY CONDITIONS ARE EXPECTED TODAY. HOWEVER...
FUELS SHOULD BE FAIRLY MOIST FROM RECENT RAINFALL. THIS WILL KEEP
FIRE DANGER LOW.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WIND ADVISORY UNTIL NOON EST TODAY FOR NCZ033-049-050-501-503-
505.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL
SHORT TERM...WIMBERLEY
LONG TERM...DEO
AVIATION...JDL
FIRE WEATHER...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
358 AM EST WED FEB 20 2013
.SYNOPSIS...
AN ELONGATED AREA OF HIGH PRESSURE WILL RIDGE DOWN FROM CENTRAL
CANADA INTO THURSDAY. A FRONTAL SYSTEM IS EXPECTED TO MOVE EAST
FROM TEXAS THURSDAY AND SHOULD BE EAST OF OUR AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
DEEP LOW PRESSURE WILL LIFT ACROSS NEW ENGLAND AND THE CANADIAN
MARITIMES DURING THE NEAR TERM...ALLOWING DEEP LAYER RIDGING TO
BUILD INTO MUCH OF THE EASTERN CONUS THROUGH THE PERIOD. THIS WILL
SUPPORT A VERY DRY AIR MASS OVER OUR AREA. THE LATEST RAP SOUNDINGS
INDICATE VERY STRONG WINDS (50-60 KT) THIS MORNING ABOVE 4000 FEET
ACROSS OUR NORTHERN ZONES. HOWEVER...THERE IS ALSO A VERY SHALLOW
MIXED LAYER IN THE MTN VALLEYS WITH A STRONG INVERSION RISING
THROUGH THE CORE OF THE STRONGEST WINDS. IT/S NOT SURPRISING THAT
WHILE THE PEAKS AND RIDGE TOPS OF THE NORTHERN MTNS ARE HOWLING AT
THIS HOUR (50-60 MPH WINDS RECENTLY OBSERVED AT GRANDFATHER
MTN)...THE WINDS ARE RELATIVELY SUBDUED IN THE LOWER ELEVATIONS.
THERE MAY BE A BRIEF PERIOD OF TIME LATER THIS MORNING WHEN THE
MIXING DEEPENS A LITTLE AND STRONGER WIND GUSTS DESCEND INTO THE
VALLEYS...SO THE WIND ADVISORY WILL BE CONTINUED...BUT MAINLY TO
HIGHLIGHT THE HIGHEST ELEVATIONS.
SKY COVER WILL INCREASE A BIT LATER TODAY...AS THE UPPER JET AXIS
LIFTS NORTHEAST FROM THE SOUTHERN PLAINS...ALLOWING CIRRUS TO WAFT
OVER THE AREA. THIS MAY RESULT IN A BRIEF PERIOD OF MOSTLY CLOUDY
SKIES ACROSS THE AREA THIS EVENING. THICKNESSES WILL REMAIN
RELATIVELY LOW UNDER THE AXIS OF THE BROAD UPPER TROUGH...SO MAX
TEMPERATURES ARE EXPECTED TO AVERAGE ABOUT A CATEGORY BELOW NORMAL.
WITH THE DRY AIR MASS AND GOOD RADIATIONAL COOLING CONDITIONS
EXPECTED TONIGHT...MIN TEMPS ARE EXPECTED TO AVERAGE 5-10 DEGREES
BELOW CLIMO.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 2 AM WED...HIGH PRESSURE STILL EXPECTED TO MAINTAIN QUIET
CONDITIONS FOR THE DAYTIME HOURS THU. RIDGE AXIS BEGINS TO SPILL
ACROSS THE APPALACHIAN CHAIN AS THE DAY PROGRESSES...SETTING THE
STAGE FOR CAD THAT WILL DEVELOP THU NIGHT. WARM FRONT WILL EDGE
NORTHEAST TOWARDS OUR AREA FROM THE GULF COAST THU BUT WON/T QUITE
MAKE IT BY 00Z. SKIES SHOULD BE MOSTLY CLEAR IN THE MORNING BUT
CLOUDS WILL INCREASE IN THE AFTERNOON AS MOISTURE ADVANCES NORTHWARD
AHEAD OF THE FRONT. HIGHS LOOK TO BE SLIGHTLY TO A FEW DEGREES ABOVE
NORMAL NONETHELESS.
THE ACTION BEGINS SHORTLY AFTER 00Z FRI AS THE WARM FRONT LIFTS INTO
THE SOUTHWEST ZONES OF OUR CWFA. ISENTROPIC LIFT WILL BE ENHANCED BY
STRONG LOW LEVEL JET /WITH BETTER WINDS AT 700 THAN 850MB/. THE
PRECIP WILL FALL INTO THE INITIALLY DRY COLD AIR NEAR THE SURFACE AND
THAT WILL BEGIN TO ENTRENCH THE WEDGE THAT OFFERS BIG CHALLENGES FOR
THE FORECAST THROUGH MOST OF THE SHORT TERM PERIOD. QPF FOCUSES ALONG
THE BOUNDARY OF THE WEDGE IN THE SOUTHWEST MTNS SOUTHWARD INTO THE
SAVANNAH RIVER VALLEY. PWAT VALUES /SREF MEAN AROUND 1 INCH/ ARE WELL
ABOVE NORMAL PER RAOB CLIMATOLOGY AT KFFC/KGSO BUT NOT OFF THE
CHARTS. I PREFER THE QPF OFFERED BY THE GFS WHICH IS A BIT MORE
MODEST THAN THE NAM AND BETTER MATCHES EXPECTED PRECIP DISTRIBUTION
GIVEN THE SETUP. RAW MODEL TEMPS FROM THE NAM HOWEVER BEST REFLECT
THE CAD. ALSO OF NOTE THU NIGHT ARE PRESENCE OF SLIGHTLY UNSTABLE
PARCELS LIFTED FROM ABOVE THE SFC INVERSION...MOSTLY OVER THE
MOUNTAINS. WILL INCLUDE SCHC THUNDER THERE.
ISENTROPIC LIFT CONTINUES INTO FRIDAY. WIND SPEEDS DO DIMINISH AND
SOME DRIER AIR WORKS IN ALOFT FROM THE SOUTHWEST WHICH WILL CUT DOWN
ON PRECIP PRODUCTION. LIFT REMAINS IN SOME FASHION THROUGHOUT THE DAY
SO I BELIEVE THE UNBROKEN PERIOD OF LIGHT MODEL QPF...BUT
ACCUMULATION WILL BE SMALL. THE COLD WEDGE WILL STILL BE IN PLACE SO
MAX TEMPS WILL STRUGGLE TO GET OUT OF THE 30S OVER MUCH OF THE
CWA...EXCEPT IN THE SOUTHWEST ON ITS FRINGE. THE GFS/NAM/EC ALL HOLD
ONTO THE WEDGE INTO SATURDAY EVENING WHICH IS CERTAINLY NOT TOO LATE.
COLD FRONT EXTENDING FROM LOW OVER THE GREAT LAKES BRINGS THE FORCING
FOR A SECOND WAVE OF PRECIP FRIDAY NIGHT.
COLD FROPA POTENTIALLY MAY SCOUR OUT THE WEDGE SHORTLY AFTER DAYBREAK
SATURDAY. THIS IS ONE RECOGNIZED METHOD OF CAD EROSION PER CSTAR
RESEARCH BUT SAME RESEARCH INDICATES MODELS STILL MAY ERODE WEDGES
TOO QUICKLY. GFS/EC DON/T SHOW 925MB COLD ADVECTION GETTING GOING
UNTIL SATURDAY AFTERNOON SO I BELIEVE COOL HIGH TEMPS WILL BE FELT
SATURDAY AS WELL...WILL GO ON LOW END OF GUIDANCE. WHATEVER VESTIGE
OF THE WEDGE THAT THE FROPA IS NOT ABLE TO REMOVE WILL LIKELY BE
TAKEN OUT BY DEVELOPING COASTAL LOW SAT AFTN SO I THINK HIGHS WILL BE
ABLE TO RISE ABOVE THOSE ON FRIDAY.
SOME PRECIP WILL BE POSSIBLE SAT NIGHT WITH WRAPAROUND MOISTURE ON
THE BACK SIDE OF THE AFOREMENTIONED COASTAL LOW...MAINLY OVER THE NC
ZONES. NORTHWEST WINDS IN THE NRN MOUNTAINS WILL ENHANCE CHANCES/QPF
BUT THE MOISTURE IS SOMEWHAT SHALLOW AND ACCUMULATIONS REMAIN LIGHT.
THE ENTIRE AREA LOOKS TO BE DRY BY AROUND 06Z SUNDAY...WITH A
CLEARING TREND BEGINNING THEN.
AS FAR AS WINTER WX POTENTIAL...THE STRENGTH OF THE WARM NOSE IN THE
WARM FLOW OVER THE WEDGE WILL COMPLETELY MELT ANY SNOW GENERATED
ALOFT DURING MOST OF THE EVENT...PUTTING PTYPE DETERMINATION SOLELY
ON SFC TEMP. HOWEVER IN THE MORE SHALLOW WARM AIR ON THE LEADING EDGE
OF THE FRONT THU NIGHT...ONLY PARTIAL MELTING WOULD BE POSSIBLE WHICH
GIVEN MOIST CRYSTAL GROWTH REGION WOULD ALLOW SLEET AT THE SFC.
HIGHER ELEVATIONS MIGHT BE ABOVE THE WARM NOSE AND GET SNOW EARLY ON
AS WELL. RELATIVELY HIGH PRECIP RATES MEAN THE HIGHEST ELEVATIONS
COULD SEE UP TO A COUPLE INCHES OF SNOW AND SLEET. POPULATED AREAS
ARE EXPECTED TO GET LESS THAN AN INCH. FREEZING RAIN WILL DOMINATE
LATER THU NIGHT ONCE TOTAL MELTING OCCURS...WITH LESS THAN A QUARTER
INCH OF ACCUMULATION.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 250 AM EST WEDNESDAY...THIS PERIOD OF THE FORECAST BEGINS AT
12Z SUNDAY WITH HIGH PRESSURE CENTERED OVER TENNESSEE AND DRY
WEATHER FOR OUR AREA AT LEAST UNTIL LATE SUNDAY NIGHT. A NICE
SEASONABLY MILD DAY ON SUNDAY.
THIS HIGH MOVES TO BE CENTERED OVER PENNSYLVANIA AT 12Z MONDAY AND
BECOMES A COOLING HIGH FOR OUR AREA. IT IS INTERESTING THAT THE
BUFKIT GFS HAS A QUITE COOL SCENARIO FOR OUR REGION ON MONDAY WITH
MOISTURE BEING PULLED INTO OUR AREA AHEAD OF THE NEXT FROM
APPROACHING FROM THE WEST. THIS RUN OF BUFKIT ACTUALLY HAS SNOW
FALLING IN THE NRN MTNS MONDAY MORNING AND THEN FREEZING RAIN UNTIL
EVENING WHEN IT CHANGES OVER TO RAIN. HKY AND CLT EVEN HAS MIXED
SLEET AND SNOW THROUGH MONDAY MORNING ON THIS BUFKIT RUN. THAT
BEING SAID...SEEMS TOO COLD AND UNREASONABLE AT THIS POINT AND GOING
WITH ALMOST ALL RAIN WITH THIS EVENT. THE CUT OFF LOW WILL MOVE
SLOWLY NE ACROSS THE CENTRAL MISSISSIPPI VALLEY MONDAY AS THE FRONT
CROSSES THE SOUTHEAST TOWARD OUR AREA. 925MB UPSLOPE FLOW WILL BE 10
TO 15 KTS EARLY MONDAY THEN CHANGE TO A LESS FAVORABLE EAST WIND
LATER MONDAY. MOST FORCING WILL BE SOUTH AND NORTH OF OUR AREA AND
RAINFALL AMOUNTS WILL BE RATHER LOW FOR THE EVENT. THE BEST TIME FOR
A MORE PERSISTENT RAIN IS LATE MONDAY NIGHT. THE PERSISTENT LOW WILL
MOVE NORTH FROM ILLINOIS ON TUESDAY CROSSING THE GREAT LAKES
WEDNESDAY. WE WILL BE UNDER THE INFLUENCE OF WEAK HIGH PRESSURE LATE
TUESDAY AND TUESDAY NIGHT.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...A VERY DRY AIR MASS WILL PROMOTE VFR
CONDITIONS THROUGH THE PERIOD...WITH THE ONLY CLOUD COVER BEING
PROVIDED BY PERIODS OF SCT/BKN HIGH CLOUDS. WINDS WILL REMAIN W/NW
AT 5-10 KT (MORE NW AND CLOSER TO 9-13 KT AT KAVL) FOR THE NEXT FEW
HOURS...BUT WILL LIKELY GO CALM IN SOME AREAS TOWARD DAYBREAK. AS A
LEE TROUGH TAKES SHAPE...PIEDMONT WINDS ARE THEN EXPECTED TO
INCREASE OUT OF THE WEST OR W/SW BY AFTERNOON AND INCREASE AGAIN TO
5-8 KT.
OUTLOOK...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THURSDAY
WITH VFR CONDITIONS. ANOTHER WEATHER SYSTEM WILL BRING MORE
PRECIPITATION AND RESTRICTIONS ON THURSDAY NIGHT AND FRIDAY. THE
PATTERN WILL REMAIN UNSETTLED AND CONDUCIVE TO PERIODS OF
RAIN/RESTRICTIONS THROUGH THE EARLY PART OF THE WEEKEND...WITH
CLEARING POSSIBLE BY SUNDAY.
CONFIDENCE TABLE...
09-15Z 15-21Z 21-03Z 03-09Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
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...WIND ADVISORY UNTIL NOON EST TODAY FOR NCZ033-049-050-501-503-
505.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL
SHORT TERM...WIMBERLEY
LONG TERM...DEO
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
816 PM CST THU FEB 21 2013
.UPDATE...
LATEST RADAR IMAGERY SHOWS LARGE AREA OF LIGHT TO MODERATE RAIN
ACROSS THE MID STATE...BUT BACK EDGE CAN BE SEEN NOW EAST OF THE
MISSISSIPPI RIVER. HRRR TIMING INDICATES MOST OF THE RAIN WILL
LIKELY END WEST OF I-65 AROUND MIDNIGHT...WITH SOME RAIN
CONTINUING THROUGH THE NIGHT TO THE EAST. HAVE ADJUSTED POPS
DOWNWARD IN THE 06-12Z TIMEFRAME WITH CHANCE POPS IN THE WEST TO
CATEGORICAL IN THE EAST. WILL ALSO ADD MENTION OF ISOLATED THUNDER
TO THE SOUTHWEST HALF OF THE CWA THIS EVENING AS A FEW LIGHTNING
STRIKES HAVE BEEN NOTED FROM TIME TO TIME.
TEMPERATURES CURRENTLY RANGE FROM THE MID 30S ALONG THE KY BORDER
TO THE MID 40S ALONG THE AL BORDER. THESE VALUES WILL BE THE LOWS
FOR TONIGHT AS WAA CONTINUES TO INCREASE THROUGH THE NIGHT AND
TEMPERATURES WARM WELL INTO THE 40S AREAWIDE BY SUNRISE AND
POSSIBLY 50S IN OUR SOUTHERN ZONES. MADE MINOR ADJUSTMENTS TO
TEMPS BUT NO OTHER CHANGES ATTM.
&&
.PREV DISCUSSION... /ISSUED 657 PM CST THU FEB 21 2013/
UPDATE...FOR 00Z TAFS...
AVIATION...
LIGHT TO MODERATE RAIN SHOWERS CONTINUE TO MOVE ACROSS THE MID
STATE THIS EVENING..WITH OBS INDICATING A FEW LIGHTNING STRIKES IN
THE STRONGER CELLS. CEILINGS ARE EXPECTED TO LOWER TO AROUND 2500 FEET
AROUND MIDNIGHT AS THE PRECIP CONTINUES TO WEAKEN AND BECOME MORE
SCATTERED. RAIN SHOULD TAPER OFF FROM WEST TO EAST IN THE EARLY
MORNING HOURS ON FRIDAY WITH CEILINGS INCREASING AND CLOUDS
THINNING THROUGHOUT THE DAY.
PREV DISCUSSION... /ISSUED 313 PM CST THU FEB 21 2013/
DISCUSSION...
LATEST RADAR IMAGERY SHOWING THE WIDESPREAD RAINFALL MASSING WITH
THE LEADING EDGE APPROACHING I-65. LITTLE IN THE WAY OF LIGHTNING
RETURNS ACROSS WESTERN TN. HOWEVER...WE ARE GETTING SOME ACTIVITY
ALONG AND WEST OF THE MS RIVER. SOUTHWARD SUPPRESSION OF THE
INSTABILITY AXIS HAS OCCURRED OVER THE PAST FEW HOURS HOWEVER. THE
WIDESPREAD RAINFALL EXTENDS WESTWARD THROUGH CENTRAL AR.
THE ASSOCIATED STRONG UPPER LEVEL SYSTEM IS TRACKING ACROSS KANSAS
WITH A NORTHEASTWARD MOVEMENT. THUS...A TRACK THIS FAR TO OUR
NORTHWEST WILL LEAVE TN ON THE WARMER SIDE OF THE STORM SYSTEM AND
WE WILL CONTINUE TO SEE WET BULB TEMPS INCH UPWARD. RIGHT
NOW...THOSE WET BULB TEMPS ARE ABOVE FREEZING ACROSS THE
SOUTHWESTERN HALF OF THE MID STATE. CURRENT TEMPS ARE IN THE 40S FOR
MOST AREAS.
TONIGHT...THE RAINFALL WILL OVERSPREAD THE AREA. STILL EXPECTING
THE SHOWALTER AND THETA E INSTABILITY AXES TO MOVE ACROSS THE AREA
OVERNIGHT. SO...TSTMS WILL BE INCLUDED AS WELL. THE SHOWERS WILL END
BY FRIDAY MORNING BUT WILL LIKELY CONTINUE A SLIGHT CHANCE ACROSS
THE PLATEAU FOR FRIDAY MORNING.
PARTIAL CLEARING EXPECTED DURING THE DAY ON FRIDAY AS SOME OF THE
HIGHER CLOUDINESS HANGS ON. LOOKS LIKE A DRY BUT MILD DAY AS HEIGHTS
ARE ON THE INCREASE.
ON FRIDAY NIGHT...SOME PATCHY FOG WILL BE POSSIBLE LATE. SKIES WILL
BE PARTLY CLOUDY BUT DEWPOINTS WILL REMAIN SOMEWHAT ELEVATED. TOVER
VALUES WILL BE FAVORABLE FOR SOME PATCHY FOG DEVELOPMENT. MILD
CONDITIONS AGAIN FOR SATURDAY UNDER PCLDY SKIES.
IN THE EXT FCST...AFTER A COLD FRONT BRINGS A CHANCE OF SHOWERS TO
THE AREA ON MONDAY...WE THEN TRANSITION TO SOMEWHAT COLDER TEMPS AND
A SEMI-UNSETTLED REGIME. EURO AND GFS BOTH IN SUPPORT OF A GENERAL
TROUGHING PATTERN IN THE EAST WITH A FEW WEAK UPPER LEVEL SYSTEM
TRAVERSING THE AREA. NOTHING MUCH IN TERMS OF WINTRY WEATHER TO GET
EXCITED ABOUT AT THIS POINT. HOWEVER...I WILL ELECT TO PLACE A
RAIN/SNOW MIX IN THE FCST FOR WED NT. POPS WILL BE LOW FOR NOW.
VERSUS THE MEX GUIDANCE...SLIGHT UNDERCUTS THROUGH THE EXTENDED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1155 PM CST TUE FEB 19 2013
.AVIATION...
RAIN AND LOWERING CEILINGS CONTINUE TO SPREAD NORTHWARD INTO KLBB
AND SHOULD BEGIN IMPACTING KCDS VERY SHORTLY AS WELL. RAIN SHOULD
EDGE FAR ENOUGH EAST TO LET UP CLOSE TO DAYBREAK ALTHOUGH LATEST
RAP RUNS REDEVELOP SHOWERS SOUTHWEST OF KLBB AGAIN NEAR DAYBREAK.
THE HRRR AVIATION FLIGHT RULES SPREAD LIFR CONDITIONS INTO KLBB AS
WELL LATER IN THE NIGHT WHICH MAY DEPEND ON REMAINING RAIN AREAS
AT THAT TIME AS WELL. A MOIST SOUTHEAST LOW LEVEL FLOW SHOULD
MAINTAIN IFR TO MVFR CEILINGS MUCH OF THE DAY ON WEDNESDAY...WHILE
SHOWERS AND THUNDER ARE EXPECTED TO REDEVELOP DURING THE EVENING
NEAR OR JUST WEST OF KLBB AS A STRONGER STORM APPROACHES FROM THE
WEST. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 1007 PM CST TUE FEB 19 2013/
UPDATE...
A LARGE RAIN SHIELD CONTINUES TO FAN OUT ACROSS SOUTHWEST TEXAS
AND SOUTHEAST NEW MEXICO INTO NORTHWEST TEXAS LATE THIS EVENING
JUST IN ADVANCE OF A DISTURBANCE EJECTING TOWARDS THE TEXAS
PANHANDLE. LATEST SHORT TERM SOLUTIONS SPREAD THE RAIN MORE
GENEROUSLY ACROSS THE AREA OVERNIGHT...THEN PUSHING OFF TO THE
EAST WEDNESDAY MORNING WITH DIMINISHING TREND. WE HAVE UPDATED FOR
HIGHER RAIN CHANCES OVERNIGHT. RETAINED ISOLATED THUNDER AS WELL...
ALTHOUGH WE HAVE NOT SEEN LIGHTNING NEARER YET THAN SOUTHWEST NEW
MEXICO. THUNDER CHANCES STILL ON-TRACK FOR WEDNESDAY NIGHT. RMCQUEEN
PREV DISCUSSION... /ISSUED 515 PM CST TUE FEB 19 2013/
AVIATION...
AREAS RAIN AND MVFR CIG AND VSBY EXPECTED TO SPREAD INTO THE AREA
DURING THE EVENING FROM THE SOUTHWEST. MOST OF RAIN SHOULD PASS TO
THE EAST BY DAYBREAK WEDNESDAY THOUGH IFR CIGS LIKELY TO DEVELOP
AND MAY SEE LOW VSBYS AS WELL PERSISTING THROUGH MUCH OF THE DAY.
STRONG THUNDERSTORMS EXPECTED JUST BEYOND THIS TAF. RMCQUEEN
PREV DISCUSSION... /ISSUED 343 PM CST TUE FEB 19 2013/
SHORT TERM...
THINGS ARE BEGINNING TO TAKE SHAPE FOR A WET WED. WV IMAGERY SHOWS A
CONSIDERABLE AMOUNT OF TROPICAL MOISTURE AHEAD OF A SHORTWAVE OVER
THE BAJA PENINSULA...WHICH IS SPREADING HIGH LEVEL CLOUD COVER OVER
THE SOUTHERN HALF OF THE FA. A LLJ WILL DEVELOP OVER THE AREA TONIGHT
TRANSPORTING LOW LEVEL MOISTURE FROM THE GOMEX WHICH WILL COVER THE
AREA IN STRATUS AS A SHORTWAVE OVER THE BAJA PENINSULA PROGRADES.
THIS WILL PROVIDE GUSTY SURFACE WINDS IN THE RANGE OF 20 TO 30 MPH.
CURRENT RADAR MOSAIC IMAGERY IS SHOWING PRECIP OVER THE TRANS
PECOS/PERMIAN BASIN REGION. MODELS APPEAR TO BE HANDLING THIS
WELL...ESPECIALLY THE HIRES MESOSCALE MODELS. THIS PRECIP IS PROGGED
TO SPREAD NEWRD AND BECOME MORE WIDESPREAD AS A RESULT OF ISENTROPIC
LIFTING. RAIN SHOWERS WILL BECOME MORE WIDESPREAD THROUGH LATE
EVENING AND TOMORROW MORNING...MAINLY FOR THE SOUTHERN AND EASTERN
ZONES OF THE FA. ELEVATED CAPE WILL AID IN THE POSSIBILITY OF HAVING
AN ISOLATED THUNDERSTORM OR 2. A LULL IN PRECIP IS EXPECTED MIDDAY
TOMORROW FOR THE WESTERN HALF OF THE FA AS A DRYLINE SETS UP ALONG
THE TX/NM STATE LINE. CONVERGENCE ALONG THE DRYLINE ALONG WITH
ISENTROPIC LIFTING AHEAD OF IT WILL PROMOTE THUNDERSTORM
DEVELOPMENT. STRONG WIND SHEAR...0 TO 6KM SHEAR AROUND 100 KTS AND
SRH UPWARDS OF 600 M2/S2...WITH VERY MARGINAL INSTABILITY...MU CAPE
OF 500 J/KG...WILL HELP PROMOTE SOME STRONG THUNDERSTORM
DEVELOPMENT...A FEW POSSIBLY BEING SEVERE. THESE SHOULD BE ISOLATED
IN NATURE DUE TO LACK OF STRONG AND WIDESPREAD INSTABILITY. THE
SOUTHERN AND EASTERN ZONES OF THE FA ARE IN THE MOST FAVORABLE AREA
FOR STRONG THUNDERSTORM DEVELOPMENT. ALDRICH
LONG TERM...
THE UPPER LOW MENTIONED IN THE SHORT TERM WILL BE MAKING FURTHER
PROGRESSION EAST ACROSS THE DESERT SOUTHWEST AND PROVIDING
CONSIDERABLE LIFT FOR ASCENT ACROSS WEST TEXAS WEDNESDAY
EVENING/NIGHT. HOWEVER...MOISTURE AND INSTABILITY APPEAR
LIMITED...WITH DEWPOINTS IN THE 30S-LOW 40S AND DEEP LAYER MUCAPE
PERHAPS APPROACHING 500 J/KG ACROSS PORTIONS OF THE ROLLING PLAINS.
IMPRESSIVE HODOGRAPHS...OWING TO INCREASING WIND FIELDS AND
EVIDENCED BY 0-3 KM SHEAR VECTORS OF 50-60 KNOTS...WILL ALLOW FOR
ROTATING STORMS CAPABLE OF PRODUCING LARGE HAIL. STOUT FRONTAL
INVERSION WILL INHIBIT SURFACE BASED CONVECTION...BUT STRENGTH OF
FORCING COMBINED WITH WIND SHEAR SHOULD ALLOW FOR ELEVATED STORMS TO
DEVELOP AS MID LEVELS COOL AND SUBSEQUENTLY CAUSE LAPSE RATES TO
STEEPEN. EXPECT STORMS TO BE ORGANIZED IN A LINEAR FASHION ALONG THE
PACIFIC FRONT.
ACTIVITY SHOULD COME TO AN END EARLY THURSDAY MORNING BEHIND THE
FRONT AND ALLOW DRIER AIR TO FILTER IN. WINDS WILL RAMP UP QUICKLY
BY MID MORNING WITH SPEEDS INCREASING TO 25-35 MPH. WIND MAXIMA
ALOFT WILL TRAVERSE EAST BY EARLY AFTERNOON...LIMITING THE CHANCES
OF SEEING SUSTAINED ADVISORY LEVEL CRITERIA OVER A LARGE AREA. THIS
SHOULD ALSO KEEP FIRE WEATHER CONCERNS FROM ESCALATING ABOVE BRIEF
LOW END CRITICAL CONDITIONS. A SECONDARY COLD FRONT WILL PUSH SOUTH
THURSDAY EVENING AND ALLOW OVERNIGHT LOWS TO FALL MAINLY INTO THE
20S AREAWIDE.
SURFACE RIDGING AND LIGHT UPSLOPE WINDS WILL BUILD IN FOR FRIDAY AND
KEEP TEMPERATURES IN THE 50S BEFORE LEE TROUGHING AND DOWNSLOPING
WARM READINGS BACK INTO THE 60S FOR THE WEEKEND. A WEAK UPPER TROUGH
WILL SKIRT ACROSS THE AREA EARLY SATURDAY...BUT CONDITIONS WILL
REMAIN DRY.
LATE SUNDAY OR EARLY MONDAY WILL BRING ABOUT THE NEXT MENTIONABLE
UPPER LEVEL TROUGH AND FRONTAL PASSAGE. THE CURRENT TRACK AND
LOCATION WOULD SUGGEST AN INCREASE IN WINDS WITH SOME POTENTIAL FOR
BLOWING DUST...BUT DETAILS ON ITS PROGRESSION WILL HAVE TO BE
MONITORED IN FOLLOWING FORECASTS. REMAINING IN A PROGRESSIVE
PATTERN...EARLY TO MID WEEK NEXT WEEK MAY BRING ANOTHER SYSTEM
AFFECTING THE SOUTHERN PLAINS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 55 34 51 26 54 / 0 50 30 40 0
TULIA 54 36 47 32 49 / 0 70 50 60 0
PLAINVIEW 53 38 47 33 56 / 0 70 50 60 0
LEVELLAND 54 41 54 33 57 / 0 70 40 50 0
LUBBOCK 56 41 50 35 58 / 0 70 50 60 0
DENVER CITY 55 41 64 32 60 / 10 70 20 30 0
BROWNFIELD 54 41 57 35 59 / 0 70 40 50 0
CHILDRESS 57 38 44 37 56 / 0 80 70 70 10
SPUR 57 40 47 37 61 / 0 80 70 70 10
ASPERMONT 62 41 49 40 63 / 0 80 70 70 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
1141 PM CST TUE FEB 19 2013
.DISCUSSION...
SEE AVIATION DISCUSSION BELOW.
&&
.AVIATION...
RAIN CONTINUES TO MOVE OFF TO THE NORTH AND EAST AND SHOULD BE
NORTHEAST OF ALL THE TAF SITES(EXCEPT HOB) SHORTLY AFTER THE
PERIOD BEGINS. EXPECT CEILINGS TO LOWER TO MVFR LATE TONIGHT AND
WEDNESDAY MORNING. LOWER CEILINGS WILL LIFT WEST BY LATE MORNING...
BUT CONTINUE TO AFFECT KHOB AND KMAF AFTER 20/18Z. AFTER A BRIEF
RESPITE FROM 20/19Z TO 21/00Z...THINK MVFR CEILINGS WILL AGAIN
IMPINGE UPON KMAF...IF NOT KHOB...BEFORE BEING SWEPT EAST BY A
PACIFIC COLD FRONT. THUNDERSTORMS COULD DEVELOP AFTER 21/00Z WITH
KHOB AND KMAF HAVING THE BEST CHANCE OF SEEING ANY ACTIVITY.
&&
.PREV DISCUSSION... /ISSUED 523 PM CST TUE FEB 19 2013/
DISCUSSION...
THE LATEST AVIATION DISCUSSION IS INCLUDED BELOW.
AVIATION...
MVFR CEILINGS AND VISIBILITIES COULD AFFECT ALL BUT KFST THIS
EVENING AS RAIN DEVELOPS AND MOVES EASTWARD OVER THE REGION. THINK
ANY LOWER CEILINGS AND VISIBILITY WILL LIFT AFTER THE
PRECIPITATION PASSES...BUT WILL REDEVELOP LATE TONIGHT/EARLY
WEDNESDAY MORNING. MVFR CEILINGS SHOULD LIFT WEST TO EAST...BUT
COULD AFFECT KMAF UNTIL AT LEAST 20/18Z. WINDS WILL BE ON THE
INCREASE FROM THE SOUTH AND SOUTHWEST LATE WEDNESDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 323 PM CST TUE FEB 19 2013/
DISCUSSION...
WV IMAGERY SHOWS THE UPPER TROUGH ALONG THE WEST COAST NEAR THE
OR/CA BORDER...TRANSITIONING FLOW ALOFT OVER WEST TEXAS/SE NM FROM
ZONAL TO SW AS IT PUSHES THE RIDGE EAST. W/IN THIS FLOW ALOFT IS A
THICK PLUME OF STR MSTR...PUTTING THE KIBOSH ON AFTERNOON HIGHS AND
WINDS OUT WEST. BUFFER AND LATEST RUC SOUNDINGS AT KGDP INDICATE
MUCH LESS MIXING AND HEAVIER CLOUD COVER...SO WE/LL CANCEL THE
CURRENT WIND WARNINGS/ADVISORIES THERE FOR THE AFTERNOON PACKAGE.
IN ITS PLACE...WE/LL INCREASE POPS OVER MUCH OF THE AREA. SHORT
RANGE MODELS ARE ALL CONSISTENT IN BRINGING A SHORTWAVE THRU THE
NORTHERN HALF OVER THE CWA OVERNIGHT...MAINLY NORTH OF I-10/20 UNDER
A NAM-ADVERTISED LFQ OF A H2 125+KT JET. AREA RADARS ALREADY SHOW
SHRA HAS DEVELOPED S OF KELP. FORECAST SOUNDINGS STILL SHOW FAIRLY
DRY SUBCLOUD LAYERS...SO QPF WILL BE LIGHT.
WEDNESDAY...LATEST MODELS HAVE SLOWED THE UPPER TROUGH FROM 24 HRS
AGO...AND BRING IT TO CENTRAL AZ BY 00Z THURSDAY. H7 PRESSURE
GRADIENT INCREASES TO 60M/150NM OVER THE GUADALUPES BY 18Z
WEDNESDAY...W/SFC GRADIENTS INCREASING AFTER 00Z THURSDAY AS A SFC
TROUGH MOVES SOUTH OF THE AREA...AND A LEESIDE SFC TROUGH SINKS INTO
THE SOUTH PLAINS THURSDAY AFTERNOON. AS THE UPPER TROUGH EJECTS
NE. HIGH WINDS WILL BE POSSIBLE THRU THE GUADALUPES FROM WED
AFTERNOON THRU THURSDAY...AND WE/LL ISSUE A WARNING TO COVER THIS
THRU THEN. ELSEWHERE...ADVISORIES WILL BE ISSUED FOR THE ADJACENT
PLAINS...AND FOR THE MTNS SOUTH. BLDU WILL STILL BE
POSSIBLE...DESPITE ANY QPF. W/THIS INCREASED SW FLOW...AND DESPITE
CLOUD COVER/COOLER TEMPS...RH/S OUT WEST SHOULD STILL REACH CRITICAL
LEVELS BY THE AFTERNOON. EAST OF THIS...INSTABILITY WILL BEGIN
INCREASING IN BETTER MOISTURE OVER THE EASTERN ZONES. FORECAST
SOUNDINGS SHOW A CAP...BUT A SHORTWAVE/LIFT AHEAD OF THE TROUGH MAY
BE SUFFICIENT ENOUGH TO KICK OFF A THUNDERSTORM OR TWO DURING THE
LATE MORNING/AFTERNOON. BY 00Z THURSDAY...MODELS SHARPEN UP A
DRYLINE MID-CWA...W/A WARM FRONT AND EVEN THE HINT OF A TRIPLE POINT
EAST. FORECAST SOUNDINGS LOSE THE CAP WEDNESDAY EVENING...FOR
THUNDERSTORM DEVELOPMENT ALONG AND EAST OF THE DRYLINE...W/BEST
CHANCES OVER THE UPPER CONCHO VALLEY. STILL NOT READY TO PULL THE
TRIGGER ON MENTIONING SEVERE STORMS YET...AND WOULD LIKE TO SEE
BETTER MID-LVL LRS. FORECAST SOUNDINGS CONTINUE TO INDICATE 0-6KM
BULK SHEAR OF 70KTS ALONG THE DRYLINE...AND ANY STORMS THAT DO
DEVELOP SHOULD MOVE EAST OUT OF THE AREA AT 40+KTS. THURSDAY INTO
THE EXTENDED CONTINUES TO LOOK DRY AND WINDY. W/THE EJECTION OF THE
UPPER TROUGH...THE ECMWF/CMC BRING IN THE NEXT TROUGH FLAT/FAST
FRIDAY...WHILE THE SLOWER...DEEPER GFS ARRIVES SATURDAY. ALL THREE
MODELS FINISH OUT THE EXTENDED WITH A SERIES OF UPPER LEVEL SYSTEMS
BRUSHING NORTH OF THE AREA...SUGGESTING WIND AND FIRE WX WILL BE
CANDIDATES FOR CONCERN THRU MIDWEEK NEXT WEEK.
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...FIRE WEATHER WATCH THURSDAY AFTERNOON FOR THE FOLLOWING ZONES...
GUADALUPE MOUNTAINS NP/LINCOLN NF/LNZ...SOUTHEAST
PLAINS/BLM ROSWELL/LNZ.
HIGH WIND WARNING FROM 11 AM WEDNESDAY TO 5 PM MST THURSDAY FOR
THE FOLLOWING ZONES... GUADALUPE MOUNTAINS OF EDDY COUNTY.
RED FLAG WARNING FROM NOON TO 6 PM MST WEDNESDAY FOR THE
FOLLOWING ZONES... GUADALUPE MOUNTAINS NP/LINCOLN NF/LNZ...
SOUTHEAST PLAINS/BLM ROSWELL/LNZ.
WIND ADVISORY FROM 11 AM TO 5 PM MST WEDNESDAY FOR THE FOLLOWING
ZONES... EDDY COUNTY PLAINS.
TX...FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR THE FOLLOWING ZONES... ANDREWS...BORDEN...
CRANE...DAWSON...ECTOR...GAINES...GLASSCOCK...GUADALUPE
MOUNTAINS...HOWARD...LOVING...MARTIN...MIDLAND...PECOS...
REAGAN...REEVES COUNTY AND UPPER TRANS PECOS...UPTON...VAN
HORN AND HIGHWAY 54 CORRIDOR...WARD...WINKLER.
WIND ADVISORY FROM NOON WEDNESDAY TO 6 AM CST THURSDAY FOR THE
FOLLOWING ZONES... BIG BEND AREA...DAVIS/APACHE MOUNTAINS
AREA...MARFA PLATEAU...VAN HORN AND HIGHWAY 54 CORRIDOR.
HIGH WIND WARNING FROM 11 AM WEDNESDAY TO 5 PM MST THURSDAY FOR
THE FOLLOWING ZONES... GUADALUPE MOUNTAINS.
RED FLAG WARNING FROM 1 PM CST /NOON MST/ TO 7 PM CST /6 PM MST/
WEDNESDAY FOR THE FOLLOWING ZONES... DAVIS/APACHE MOUNTAINS
AREA...GUADALUPE MOUNTAINS...LOVING...MARFA PLATEAU...
PRESIDIO VALLEY...REEVES COUNTY AND UPPER TRANS PECOS...VAN
HORN AND HIGHWAY 54 CORRIDOR.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1117 PM CST TUE FEB 19 2013
.AVIATION...
/6Z TAFS/
VFR CONDITIONS PREVAIL ACROSS THE REGION WITH AREAS OF LIGHT RAIN
FALLING OUT OF CEILINGS AROUND 6000FT. THIS IS EXPECTED TO
CONTINUE FOR MOST OF THE NIGHT WITH A GRADUAL LOWERING OF CIGS
THROUGH WEDNESDAY MORNING. THE RAIN MAY BE INTERMITTENT TOMORROW
WITH A BREAK FROM LATE MORNING INTO THE AFTERNOON. CIGS ARE
EXPECTED TO CONTINUE TO LOWER THROUGH EARLY WEDNESDAY EVENING.
FORCING FROM A STRONGER DISTURBANCE IS EXPECTED TO INCREASE
TOMORROW NIGHT WITH AN INCREASE IN COVERAGE OF SHOWERS ACROSS MUCH
OF NORTH TEXAS. IFR CONDITIONS EXPECTED TOMORROW NIGHT WITH
SCATTERED SHOWERS AND THUNDERSTORMS TOWARD DAYBREAK THURSDAY.
DUNN
&&
.UPDATE...
TOP-DOWN SATURATION CONTINUES TO OCCUR RAPIDLY FROM COMANCHE AND
CISCO...WEST TOWARD ABILENE AND SAN ANGELO...AS FIRST DISTURBANCE
CONTINUES LIFTING OVER WEST TEXAS. VERY LIGHT RAIN OR SPRINKLES
AND LOWERING CLOUD DECKS TO 8-10 KFT ARE NOTED ON OBSERVATIONS
ACROSS THESE AREAS. HAVE RAISED OUR FAR WESTERN COUNTIES TO CHANCE
CATEGORY FOR A VERY LIGHT RAIN THE REST OF THE EVENING...AS LARGE-
SCALE ASCENT IS SATURATING THE ATMOSPHERE QUICKLY. EXTENDED SLIGHT
CHANCES OF A VERY LIGHT RAIN/SPRINKLES TOWARD THE I-35/45 CORRIDORS.
THOROUGH EXAMINATION OF THE RAP AND SEVERAL WRF MODELS INDICATE
THAT A FEW ELEVATED THUNDERSTORMS LIKELY WILL DEVELOP ACROSS THE
SOUTHWEST COUNTIES BETWEEN 2-4 AM...THEN LIFT NNE ACROSS THE AREA
BETWEEN 3-9 AM WEDNESDAY. THE DISTURBANCE WILL THEN LIFT OFF TO
THE NORTHEAST BY MIDDAY WEDNESDAY WITH A DIMINISHING TREND IN
OVERALL RAINFALL COVERAGE DURING THE AFTERNOON...THOUGH SOME
LINGERING DRIZZLE OR SPRINKLES WITHIN ESE LOW LEVEL ISENTROPIC
ASCENT WILL LIKELY CONTINUE THROUGH THE DAY. WOULD NOT USUALLY BE
CONCERNED ABOUT ANY HAIL WITH SUCH WEAK LAPSE RATES ALOFT...HOWEVER
LOW FREEZING LEVELS AROUND 9 KFT ON 00Z FWD SOUNDING MAKE IT NOT
OUT OF THE REALM OF POSSIBILITY FOR PEA HAIL OR EVEN GRAUPEL/SLEET.
WILL NOT UPDATE HAZARDOUS WEATHER OUTLOOK AT THIS TIME WITH
CONFIDENCE WAVERING ON ABILITY OF UPDRAFTS TO ESTABLISH ABOVE THE
INVERSION AT THIS TIEM.
THE MAIN WINDOW FOR THE MAIN DISTURBANCE LIFTING OUT AND SEVERE
WEATHER AHEAD OF THE COLD FRONT REMAINS BETWEEN MIDNIGHT AND NOON
THURSDAY MORNING.
05/
&&
.PREV DISCUSSION... /ISSUED 352 PM CST TUE FEB 19 2013/
WATER VAPOR IMAGERY THIS AFTERNOON SHOWS A WEAK SHORTWAVE MOVING
INTO NEW MEXICO WITH A MUCH STRONGER SYSTEM DIVING ALONG THE
CALIFORNIA COAST. THE FIRST SHORTWAVE WILL EJECT OVER THE REGION
TONIGHT...PROVIDING LIFT FOR WIDESPREAD RAIN ACTIVITY. ASIDE FROM
INCREASING MID AND HIGH LEVEL CLOUD COVER...THE NEXT SEVERAL HOURS
WILL BE QUIET AND THEN WE WILL START TO SEE LIGHT RAIN SPREADING
ACROSS THE REGION FROM THE SOUTHWEST. WITH THE LOWER LEVELS OF THE
ATMOSPHERE VERY DRY /DEWPOINTS HAVE FALLEN INTO THE TEENS AND
LOWER 20S ACROSS ALMOST ALL OF THE REGION/ VIRGA WILL OCCUR FOR A
FEW HOURS UNTIL TOP-DOWN SATURATION OCCURS LATER THIS EVENING.
MODEST WARM AIR ADVECTION WILL NOT BEGIN UNTIL TOMORROW WHEN 925
AND 850 MB WINDS INCREASE TO 30 TO 50 MPH...THEREFORE LOW LEVEL
SATURATION TONIGHT WILL HAVE TO COME FROM TOP-DOWN PROCESSES.
FORECAST MODEL SOUNDINGS INDICATE THAT SATURATION WILL OCCUR AS
THE LARGE SCALE LIFT INCREASES TONIGHT AND EXPECT WIDESPREAD
SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP ACROSS MOST OF THE
REGION. MODEL GUIDANCE CONTINUES TO SUGGEST THAT MOST OF THE
RAINFALL WILL OCCUR OVER THE WESTERN AND NORTHERN COUNTIES OF THE
CWA /CLOSER TO THE TRACK OF THE UPPER LEVEL SHORTWAVE/...THEREFORE
HAVE TAPERED POPS FROM NORTHWEST TO SOUTHEAST TONIGHT.
A NEW ADDITION TO THE FORECAST FOR LATE TONIGHT AND WEDNESDAY
MORNING IS THE INCLUSION OF A MENTION OF SLEET ACROSS THE NORTHERN
THIRD OF THE REGION. THE MODELS AND FORECAST SOUNDINGS CONTINUE TO
INDICATE A COOLING OF 850 MB TEMPERATURES AS THE RAIN STARTS
TONIGHT. FORECAST SOUNDINGS SHOW THAT THE NEAR SURFACE LAYER WILL
REMAIN ABOVE FREEZING THROUGH AT LEAST A 3 KFT DEPTH...ENOUGH TO
PREVENT ANY SIGNIFICANT ACCUMULATIONS OF WINTER PRECIPITATION.
SNOW WOULD LIKELY MELT IN THIS WARM SURFACE LAYER...HOWEVER SLEET
MAY FALL FAST ENOUGH TO ALLOW SOME TO REACH THE SURFACE...ESPECIALLY
IN STRONGER CONVECTIVE SHOWERS OR THUNDERSTORMS. THEREFORE...WILL
MENTION A SLIGHT CHANCE FOR SLEET MIXED WITH THE RAIN LATE TONIGHT
AND EARLY WEDNESDAY MORNING...ALONG AND NORTH OF A GRAHAM TO
SULPHUR SPRINGS LINE. THERE IS A SLIGHT POSSIBILITY THAT VERY
LIGHT ACCUMULATIONS OF SLEET COULD OCCUR IN ASSOCIATION WITH A
THUNDERSTORM BUT WILL NOT MENTION ACCUMULATIONS AND DO NO EXPECT
IMPACTS.
SHOWER ACTIVITY WILL CONTINUE THROUGH THE DAY ON WEDNESDAY AS THE
FIRST UPPER LEVEL SHORTWAVE MOVES NORTHEAST OF THE REGION BUT
MODEST WARM AIR ADVECTION AND ISENTROPIC LIFT CONTINUE OVER THE
STILL COOL SURFACE LAYER. BY WEDNESDAY AFTERNOON...THE STRONGER
UPPER LEVEL SYSTEM CURRENTLY OVER CALIFORNIA WILL BE MOVING
THROUGH THE DESERT SOUTHWEST. THERE WILL NOT BE MUCH SURFACE
WARMING ON WEDNESDAY EXCEPT FOR IN OUR SOUTHERN ZONES WHERE
DEWPOINTS WILL START TO INCREASE LATER IN THE DAY. THERE WILL
LIKELY BE AN OVERALL LULL IN THE RAIN ACTIVITY WEDNESDAY EVENING
AS WE WAIT FOR THE ARRIVAL OF THE STRONGER LIFT FROM THE NEXT
APPROACHING SHORTWAVE...BUT STILL EXPECT SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS TO BE ONGOING.
AS WE HEAD INTO WEDNESDAY NIGHT...SURFACE TEMPERATURES WILL HOLD
STEADY AND/OR RISE THROUGH THE NIGHT AS STRONG WARM AIR ADVECTION
CONTINUES AND DEWPOINTS CONTINUE TO RISE. THE COLD FRONT THAT
MOVED THROUGH YESTERDAY DID NOT COMPLETELY SCOUR OUT THE MOISTURE
ACROSS SOUTH TEXAS AND THIS REMNANT FRONT WILL RETURN NORTH AS A
WARM FRONT WEDNESDAY NIGHT...BRINGING DEWPOINTS IN THE 40S AND 50S
BACK TO THE REGION. THE MAIN FOCUS FOR WEDNESDAY NIGHT AND
THURSDAY MORNING CONTINUES TO BE A LINE OF POTENTIALLY SEVERE
STORMS THAT WILL APPROACH THE AREA AFTER MIDNIGHT. THIS LINE OF
STORMS WILL MOST LIKELY BE ELEVATED AS IT REACHES OUR WESTERN
BORDER...AND INSTABILITY PARAMETERS CONTINUE TO INDICATE CAPE AND
SHEAR VALUES STRONG ENOUGH TO SUPPORT A LARGE HAIL AND DAMAGING
WIND THREAT WITH THIS LINE OF STORMS/SQUALL LINE. WHAT WE WILL BE
CLOSELY WATCHING IS THE LOCATION OF THE UPPER 50S/LOWER 60S
DEWPOINTS THAT ARE PROJECTED TO BE IN OUR SOUTHERN COUNTIES BY
DAYBREAK ON THURSDAY. THESE HIGHER DEWPOINTS ARE IMPORTANT BECAUSE
THEY COULD ALLOW THE STORMS TO BECOME MORE SURFACE BASED WHICH
COULD LEAD TO A TORNADO THREAT ACROSS OUR FAR SOUTH AND
SOUTHEASTERN COUNTIES AS LOW LEVEL WIND SHEAR AND HELICITY VALUES
WILL BE HIGH.
THERE ARE STILL SUBTLE TIMING DIFFERENCES IN THE MODELS REGARDING
HOW FAST THE SYSTEM/PACIFIC FRONT WILL MOVE. THE ECMWF IS THE
FASTEST WITH THE FRONT...BRINGING IT TO THE I-35 CORRIDOR BY 6
AM...WHILE THE NAM CONTINUES TO BE THE SLOWEST WITH THE TIMING.
UNTIL WE SEE THE LINE MATERIALIZE AND CAN TRACK ITS PROGRESS IT IS
HARD TO SAY EXACTLY WHEN THE STORMS WILL CLEAR OUR EASTERN BORDER
BUT IT SHOULD BE BY THE EARLY AFTERNOON HOURS AT THE LATEST. FOR
NOW...CONTINUE TO LINGER HIGH POPS IN THE FAR EASTERN COUNTIES
THURSDAY AFTERNOON.
BEYOND THURSDAY...THERE CONTINUE TO BE DIFFERENCES IN THE UPPER
LEVEL PATTERN BETWEEN THE EXTENDED MODELS...BUT CONTINUED TO SIDE
WITH THE ECMWF FOR THE MOST PART. A COLD FRONT WILL MOVE THROUGH
THE REGION ON FRIDAY AND WE SHOULD SEE SOUTHERLY WINDS RETURN OVER
THE WEEKEND. THE ECMWF AND CANADIAN ARE VERY SIMILAR THAT ANOTHER
STRONG UPPER LEVEL TROUGH WILL DIP INTO THE SOUTHERN PLAINS LATE
SUNDAY BRINGING A CHANCE FOR RAIN SUNDAY AFTERNOON THROUGH MONDAY
MORNING. THE MOISTURE QUALITY OVERALL WILL NOT BE GREAT BUT
SUFFICIENT ENOUGH FOR PRECIP SO WILL MOVE THE POPS BACK TO THE END
OF THE WEEKEND. ON THE OTHER HAND...THE GFS BARRELS A STRONG FRONT
THROUGH THE REGION ON MONDAY WITH CHILLY TEMPS AND A DRY FORECAST.
TEMPERATURES WILL CONTINUE TO VARY THROUGH THE END OF THE FORECAST
PERIOD AS THE PROGRESSIVE UPPER LEVEL PATTERN CONTINUES BUT AT
THIS TIME DO NOT SEE A COLD OUTBREAK OF AIR IN THE NEXT 7-9 DAYS.
HOWEVER...THERE WILL STILL BE A FEW NIGHTS WHERE FREEZING
TEMPERATURES WILL BE REACHED OVER PART OF THE AREA.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 42 46 44 70 36 / 90 90 70 80 5
WACO, TX 44 51 49 71 38 / 60 60 80 80 5
PARIS, TX 39 43 41 60 33 / 90 90 60 80 10
DENTON, TX 41 44 42 69 33 / 90 90 70 80 5
MCKINNEY, TX 41 45 43 65 32 / 90 90 70 80 5
DALLAS, TX 43 46 44 69 38 / 80 90 70 80 5
TERRELL, TX 42 47 45 67 36 / 80 80 60 80 5
CORSICANA, TX 43 50 48 67 39 / 60 60 60 80 5
TEMPLE, TX 45 53 51 71 37 / 50 60 80 80 5
MINERAL WELLS, TX 42 47 45 69 31 / 90 90 90 60 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
909 PM CST THU FEB 21 2013
.SHORT TERM...
909 PM CST THU FEB 21 2013
SNOW WAS BREAKING OUT ACROSS NORTHEAST IOWA...WITH A DUSTING BEING
REPORTED IN THE EDGEWOOD AREA OF FAYETTE COUNTY. 22.00Z HRRR
CONTINUES TO PUSH THIS BAND OF SNOW NORTHEAST ACROSS THE FORECAST
AREA THROUGH THE REMAINDER OF THE EVENING...WITH AREAS NORTH
OF INTERSTATE 94 MOST LIKELY TO SEE THE SNOW BREAK OUT BETWEEN
06Z-09Z. 22.00Z NAM ALSO IN LINE WITH THIS TREND AS WELL. WILL BE
MAKING JUST SOME MINOR TWEAKS TO THE GRIDS BASED ON CURRENT TRENDS.
SOME CONCERN AS TO SNOW AMOUNTS ACROSS NORTHEAST IOWA THROUGH 06Z.
REPORTS BACK IN DMX AREA SHOWS GENERALLY 1 TO 3 INCHES HAVE
FALLEN. 22.00Z HRRR SHOWS THE LIGHTER SNOW AREAS TO FILL IN LATER
THIS EVENING AS IT LIFTS NORTHEAST. IF THIS OCCURS THEN WILL
REALIZE THE 2 TO 3 INCHES WE HAVE ACROSS FLOYD COUNTY. OTHERWISE
SNOW AMOUNTS THROUGH 06Z MAY BE A BIT HIGH. NONE THE LESS STILL
EXPECTING LOW END WARNING CRITERIA TO BE MET IN MUCH OF NORTHEAST
IOWA...WITH THE 4 TO 6 INCHES LIKELY ELSEWHERE.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
306 PM CST THU FEB 21 2013
21.12 MEDIUM RANGE MODELS ARE SHOWING SOME DIFFERENCES REGARDING THE
EVOLUTION OF THE TROUGH SUNDAY NIGHT THROUGH TUESDAY. THE GFS WRAPS
THE TROUGH INTO AN UPPER LOW OVER THE UPPER MIDWEST. THE ECMWF TAKES
THE TROUGH INTO THE CENTRAL AND SOUTHERN PLAINS AND DEEPENS INTO AN
UPPER LOW. THE GFS TAKES THE LOW EAST OVER SOUTHERN WISCONSIN ON
MONDAY WHILE THE ECMWF TAKES IT THROUGH THE OHIO RIVER VALLEY. THIS
SYSTEM HAS THE POTENTIAL TO BRING ACCUMULATING SNOW THE AREA BUT
THERE IS CONSIDERABLE UNCERTAINTY WITH THE STORM TRACK. HAVE LEANED
TOWARD A MODEL CONSENSUS BLEND SUNDAY NIGHT THROUGH TUESDAY. THE LOW
LOOKS TO MERGE WITH A SOUTHERN STREAM SYSTEM TUESDAY INTO WEDNESDAY
STALLING OVER THE EASTERN GREAT LAKES REGION. CYCLONIC FLOW IS
EXPECTED TO SET UP OVER THE FORECAST AREA ON THE WESTERN SIDE OF THE
LOW. EMBEDDED SHORTWAVES WILL BRING CHANCES FOR LIGHT SNOW TO THE
AREA WEDNESDAY INTO THURSDAY.
&&
.AVIATION...TONIGHT AND FRIDAY
527 PM CST THU FEB 21 2013
SNOW WAS SPREADING NORTHWARD THROUGH CENTRAL IOWA LATE THIS
AFTERNOON AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM. MODELS
CONSISTENT IN PUSHING THIS SNOW INTO THE TAF SITES BETWEEN 04Z-
06Z. ONCE SNOW BEGINS CEILINGS AND VISIBILITIES WILL QUICKLY DROP
INTO THE IFR CATEGORY...WITH SOME 1/4 TO 1/2 MILE VISIBILITIES
LIKELY BETWEEN 06Z-14Z. AS THE SYSTEM PULLS NORTHEAST LIGHT SNOW
WILL CONTINUE FOR THE DAY FRIDAY...WITH VISIBILITIES EXPECTED IN
THE 1-2 MILE RANGE AND CEILINGS IN THE IFR TO LOWER MVFR CATEGORY.
EASTERLY WINDS WILL REMAIN UNDER 10 KNOTS AT KLSE AND AROUND 12
KNOTS AT KRST...WITH A SHIFT TO A MORE NORTHERLY DIRECTION AT BOTH
SITES AFTER 21Z FRIDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 PM CST THU FEB 21 2013
WI...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR WIZ041-053>055-061.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY
FOR WIZ017-029-032>034-042>044.
MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR MNZ079-086>088-094>096.
IA...WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST FRIDAY
FOR IAZ008>010-018-019-029-030.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR IAZ011.
&&
$$
SHORT TERM...RABERDING
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
232 PM CST WED FEB 20 2013
.SHORT TERM...TONIGHT THROUGH SATURDAY
232 PM CST WED FEB 20 2013
FORECAST CONCERNS ARE ON WINTER STORM IMPACTING THE AREA THURSDAY
NIGHT INTO FRIDAY.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED A COMPLEX
PATTERN ACROSS THE CONUS TODAY. AN UPPER LOW WAS LOCATED OVER NEW
ENGLAND WHILE ANOTHER WAS MOVING INTO SOUTHERN CALIFORNIA. AN UPPER
RIDGE EXTENDED FROM THE MID MISSISSIPPI RIVER VALLEY NORTH THROUGH
THE UPPER MIDWEST.
THE UPPER LOW OVER SOUTHERN CALIFORNIA WILL BE THE MAIN FEATURE TO
WATCH CLOSELY TONIGHT AS IT MOVES THROUGH ARIZONA AND NEW MEXICO
OVERNIGHT...EJECTING INTO THE CENTRAL PLAINS ON THURSDAY. THE LOW
WILL LIFT NORTHEAST THROUGH SOUTHEAST NEBRASKA EARLY FRIDAY EVENING.
AHEAD OF THE APPROACHING LOW...STRONG ISENTROPIC LIFT WILL MOVE
MOVE INTO THE FORECAST AREA ON THE 280-310 K SURFACES DURING THE
EVENING HOURS ON THURSDAY LEADING TO THE DEVELOPMENT OF SNOW.
IMPRESSIVE LIFT NOTED IN THE DENDRITIC GROWTH ZONE THURSDAY
EVENING INTO LATE THURSDAY NIGHT...WITH LIFT OF -20 UBAR/S NOTED
AT -15C. THE ONLY NEGATIVE WITH THIS SYSTEM IS THAT THE
INGREDIENTS FOR HEAVY SNOW FALL ADVECT NORTHEAST THROUGH THE
FORECAST AREA VERY QUICKLY DURING THE OVERNIGHT HOURS.
HOWEVER...MOST ARES WILL SEE A PERIOD OF HEAVY SNOWFALL WITH
ACCUMULATION RATES OF 1 TO 1.5 INCHES PER HOUR. SNOW ACCUMULATIONS
BY 12Z FRIDAY ARE EXPECTED TO RANGE FROM 5 TO 7 INCHES ACROSS MUCH
OF NORTHEAST IOWA. LOCATIONS OVER SOUTHEAST MINNESOTA AND
SOUTHWEST THROUGH CENTRAL WISCONSIN ARE EXPECTED TO SEE SNOW
ACCUMULATIONS OF 3 TO 6 INCHES. THE BULK OF THE SNOW WILL FALL
DURING THE OVERNIGHT HOURS THROUGH THE FRIDAY MORNING
COMMUTE...LEADING TO TRAVEL IMPACTS. HAVE ISSUED A WINTER STORM
WARNING FOR MOST OF NORTHEAST IOWA...EXCLUDING ALLAMAKEE
COUNTY...AND HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE REST OF
THE FORECAST AREA. SEE WATCH/WARNING/ADVISORIES SECTIONS BELOW FOR
SPECIFIC TIMING. SNOWFALL AMOUNTS HAVE TRENDED SLIGHTLY LESS IN
THE 12Z GUIDANCE AND THIS MAKES SENSE GIVEN THE PROGRESSIVE NATURE
OF THE HEAVY SNOWFALL INGREDIENTS. THE LOW WILL LIFT NORTHEAST
DURING THE DAY ON FRIDAY AND IS EXPECTED TO BE LOCATED OVER SOUTH
CENTRAL MINNESOTA BY MIDDAY FRIDAY. LIGHT SNOW LOOKS TO PERSIST
INTO FRIDAY AFTERNOON WITH ADDITIONAL ACCUMULATIONS OF 1 TO 2
INCHES POSSIBLE. THE SNOW WILL TAPER OFF SOUTH AND WEST OF
INTERSTATE 94 THROUGH THE AFTERNOON HOURS AND PERSIST NORTH OF
I-94 INTO FRIDAY EVENING. WILL HAVE TO KEEP A CLOSE EYE ON
FREEZING DRIZZLE POTENTIAL OVER SOUTHWEST INTO CENTRAL WISCONSIN
AS ICE IS LOST ALOFT LATE FRIDAY MORNING INTO EARLY FRIDAY
AFTERNOON. OTHERWISE...HIGH PRESSURE WILL BE IN CONTROL TONIGHT
INTO THURSDAY MORNING PROVIDING COOL AND QUIET CONDITIONS. HIGH
CLOUDS WILL BE ON THE INCREASE FROM THE SOUTHWEST AHEAD OF THE
APPROACHING SYSTEM. LOOK FOR LOWS TONIGHT TO RANGE FROM THE SINGLE
DIGITS BELOW ZERO ACROSS NORTH CENTRAL WISCONSIN TO THE SINGLE
DIGITS ABOVE ZERO OVER NORTHEAST IOWA.
THE LOW WILL LIFT INTO UPPER MICHIGAN EARLY ON SATURDAY AS WEAK HIGH
PRESSURE BUILDS INTO THE FORECAST AREA. MOSTLY CLOUDY SKIES ARE
EXPECTED ACROSS THE FORECAST AREA ON SATURDAY UNDER THE INFLUENCE OF
WEAK CYCLONIC FLOW IN THE WAKE OF THE DEPARTING LOW. LIGHT SNOW
COULD LINGER ACROSS NORTH CENTRAL WISCONSIN DURING THE DAY. HIGHS ON
SATURDAY WILL RANGE FROM THE MID 20S OVER CENTRAL WISCONSIN TO THE
LOWER 20S OVER SOUTHEAST MINNESOTA. A VIGOROUS TROUGH WILL MOVE
THROUGH THE PACIFIC NORTHWEST ON SATURDAY...DIVING INTO THE CENTRAL
ROCKIES SATURDAY NIGHT. THIS SYSTEM IS THE NEXT FEATURE TO KEEP A
CLOSE EYE ON.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
232 PM CST WED FEB 20 2013
20.12 MEDIUM RANGE MODELS ARE IN REASONABLE SATURDAY NIGHT THROUGH
SUNDAY SHOWING THE TROUGH PUSHING INTO THE CENTRAL ROCKIES BY SUNDAY
AFTERNOON. MEANWHILE...RIDGING WILL BUILD OVER THE UPPER MISSISSIPPI
RIVER VALLEY PROVIDING PARTLY SUNNY SKIES ON SUNDAY. HIGHS ON SUNDAY
ARE EXPECTED TO RANGE FROM THE LOWER 30S OVER CENTRAL WISCONSIN TO
THE UPPER 20S OVER NORTHEAST IOWA. THE TROUGH IS EXPECTED TO MOVE
EAST OUT OF THE ROCKIES AND INTO THE CENTRAL PLAINS AND DEEPENING
INTO A STRONG UPPER LOW. MODEL SOLUTIONS START TO DIVERGE SLIGHTLY
MONDAY INTO TUESDAY. THE 20.00 ECMWF TAKES THE LOW ACROSS EASTERN
KANSAS THROUGH NORTHERN MISSOURI MONDAY NIGHT AND INTO NORTHERN
ILLINOIS BY EARLY TUESDAY MORNING. THE GFS HAS A SLIGHTLY MORE
NORTHERLY TRACK. THIS SYSTEM WILL BRING WARMER AIR WITH IT AND THE
POTENTIAL FOR A RAIN AND SNOW MIX. THIS SYSTEM HAS THE POTENTIAL
TO BRING SIGNIFICANT SNOWFALL TO THE REGION BUT THE EXACT TRACK IS
UNCERTAIN AND WILL BE PINNED DOWN OVER THE NEXT FEW MODEL RUNS.
THE 20.00 ECMWF LIFTS THE LOW NORTH INTO EASTERN UPPER MICHIGAN BY
WEDNESDAY MORNING WHILE THE GFS TAKES IT TO THE EAST INTO THE OHIO
RIVER VALLEY. LIGHT SNOW CHANCES WILL CONTINUE TUESDAY INTO
WEDNESDAY...DEPENDING ON THE LOW TRACK.
&&
.AVIATION...THROUGH 18Z THURSDAY
1140 AM CST WED FEB 20 2013
VFR CONDITIONS TO PREVAIL THROUGH THE TAF PERIOD AS SURFACE HIGH
PRESSURE DRIFTS ACROSS HUDSON BAY. VERY DRY LOW TO MID LEVELS WILL
PRECLUDE CLOUD DEVELOPMENT AND WINDS LOOK TO GRADUALLY TURN TO THE
EAST TONIGHT. HIGH LEVEL CLOUDS ABOVE 15 KFT WILL SPILL ACROSS
THE REGION...ASSOCIATED WITH THE STORM SYSTEM COMING OUT OF THE
CENTRAL PLAINS. BY LATE THURSDAY MORNING...A TIGHTER PRESSURE
GRADIENT DEVELOPS WITH WINDS INCREASING ABOVE 10 KTS AND THERE
COULD BE HIGHER GUSTS PAST THE CURRENT TAF PERIOD...MAINLY
THURSDAY AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
232 PM CST WED FEB 20 2013
WI...WINTER WEATHER ADVISORY FROM 6 PM THURSDAY TO 6 PM CST FRIDAY
FOR WIZ041-053>055-061.
WINTER WEATHER ADVISORY FROM MIDNIGHT THURSDAY NIGHT TO 6 PM CST
FRIDAY FOR WIZ017-029-032>034-042>044.
MN...WINTER WEATHER ADVISORY FROM 6 PM THURSDAY TO 6 PM CST FRIDAY
FOR MNZ079-086>088-094>096.
IA...WINTER STORM WARNING FROM 6 PM THURSDAY TO 6 PM CST FRIDAY FOR
IAZ008>010-018-019-029-030.
WINTER WEATHER ADVISORY FROM 6 PM THURSDAY TO 6 PM CST FRIDAY
FOR IAZ011.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
316 AM CST FRI FEB 22 2013
.SYNOPSIS...
06Z SFC ANALYSIS HAS THE OCCLUDED LOW IN WEST CENTRAL MISSOURI
WITH A NEW TRIPLE POINT DEVELOPING JUST WEST OF KSTL. AN INVERTED
TROF RAN FROM THE OCCLUDED LOW INTO WESTERN IOWA. RADAR SHOWS THE
BULK OF THE MAIN SNOW MOVING NORTH INTO MN/WI. HOWEVER...VERY
LIGHT SNOW WAS BEING REPORTED AS FAR SOUTH AS MISSOURI. DEW POINTS
WERE IN THE TEENS AND 20S ACROSS MUCH OF THE MIDWEST WITH 30S AND
HIGHER FROM THE OHIO VALLEY ON SOUTH.
&&
.SHORT TERM...TODAY AND TONIGHT
RUNNING BEHIND DUE TO OTHER PROBLEMS. FIRST...BASED ON RAP TRENDS
WILL DROP HEADLINES FOR ROUGHLY THE SOUTHERN THIRD. THE OTHER
HEADLINES WILL CONTINUE FOR NOW BUT MAY GET CANCELLED OR MODIFIED
OVER THE NEXT 3-4 HRS.
RAP TRENDS INDICATE THE WAA WING OF SNOW WILL BE IN MN/WI SHORTLY.
FLURRIES OR VERY LIGHT SNOW IS SPORADIC ACROSS THE AREA BUT VERY
LITTLE IN THE WAY OF NEW ACCUMULATION SHOULD BE SEEN THROUGH 12Z.
DURING THE DAY THE RAP DEVELOPS NEW FORCING AS THE OCCLUDED LOW
MOVES UP THROUGH THE FAR WESTERN CWFA WHICH SHOULD INDUCE SOME NEW
LIGHT SNOW DURING THE DAY ACROSS THE AREA. CONDENSATION PRESSURE
DEFICITS WILL SLOWLY RISE SO THERE SHOULD BE A GRADUAL END TO THE
SNOW FROM SOUTH TO NORTH DURING THE DAY.
ADDITIONAL ACCUMULATIONS FOR THE REMAINDER OF THE DAY SHOULD RANGE
FROM A DUSTING TO PERHAPS AN INCH.
TONIGHT...CYCLONIC FLOW SHOULD CONTINUE TO KEEP LIGHT
SNOW/FLURRIES GOING ACROSS ROUGHLY THE NORTH/NORTHEAST THIRD OF
THE CWFA DURING THE EVENING THAT GRADUALLY ENDS DURING THE NIGHT.
BASED ON TEMPERATURES CURRENTLY IN MISSOURI...THE EASTERN CWFA
SHOULD SEE READING GET TO OR JUST ABOVE FREEZING DURING THE
DAYLIGHT HOURS. ..08..
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
ANOTHER ACTIVE PERIOD IS LOOMING IN THE LONG TERM...WITH ALL MODELS
SHOWING A DYNAMIC SYSTEM MONDAY THROUGH MID WEEK. THERE IS PLENTY
OF MODEL SPREAD ON TIMING AND TRACK OF THIS SYSTEM...AS WELL AS ITS
EVENTUAL EVOLUTION INTO A MAJOR LONG WAVE TROF. THUS...FOR NOW...AND
WILL FULL SUPPORT OF THIS FORECASTER...WE WILL TAKE SOME BABY STEPS
TOWARD A WINTER EVENT...OF SNOW AND POTENTIALLY WIND. I AM
ENCOURAGED THAT BOTH THE 00Z ECMWF..UKMET...GEM...AND NAM ALL TAKE
THE SYSTEM SOUTH...WITH THE BEST TRACK FOR HEAVY QPF OVER CWAS JUST
SOUTH. NOT THAT THAT WILL OCCUR...BUT I FEEL THIS WINTER REPRESENT
YET ANOTHER YEAR THAT WE MODELS WILL EVENTUALLY TRACK SYSTEMS A BIT
FARTHER NORTH THAN THEIR DAY 3 TO 7 FORECASTS. THE GFS REMAINS MUCH
FARTHER NORTH...WEAKER...AND FASTER THAN OTHER MODELS...AND IT
LARGELY DISREGARDED EXCEPT FOR INSERTING SOME SLIGHT CHANCE POPS FOR
SUNDAY NIGHT. IN THE END...IT WOULD SEEM SLOWER IS THE WAY TO GO ON
THIS SYSTEM...ESPECIALLY SINCE IT IS ANOTHER CLOSED UPPER LOW
SYNOPTIC SYSTEM. IT TRENDS HOLD TRUE ON THE ECMWF AND OTHERS...WE
ARE CERTAIN TO NEED CATEGORICAL POPS FOR MONDAY NIGHT INTO TUESDAY.
TEMPERATURES WILL REMAIN SOMEWHAT COOLER THAN SEASONAL NORMALS
THROUGHOUT THE FORECAST PERIOD. THUS...WITH HIGHS IN THE LOWER TO
MID 30S MUCH OF THE FORECAST...WE WILL SLOWLY LOSE SNOW COVER IN
PERIODS WE ARE NOT GAINING IT. THIS SEEMS PRETTY TYPICAL FOR LATE
FEBRUARY IN MY EXPERIENCE.
ERVIN
&&
.AVIATION... /ISSUED 1129 PM CST THU FEB 21 2013/
(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1121 PM CST THU FEB 21 2013
LOW PRESSURE OVER MISSOURI WILL LIFT NORTHEAST INTO WISCONSIN BY
EARLY FRIDAY EVENING. MODERATE TO HEAVY SNOW OVER THE FORECAST
AREA AND NORTH OF THE SURFACE LOW WILL LIFT NORTH EARLY THIS
MORNING WITH LINGERING LIGHT SNOWS CONTINUING INTO FRIDAY MORNING.
THE LIGHT SNOW WILL END FROM SOUTH TO NORTH BY FRIDAY AFTERNOON.
IFR TO LIFR CONDITIONS ARE EXPECTED DURING THE OVERNIGHT HOURS
WITH THE LIFR CONDITIONS MOVING OUT OF THE AREA WITH THE BAND OF
HEAVIER SNOWS. STRONG EAST WINDS WILL GRADUALLY DIMINISH EARLY
FRIDAY MORNING AND TURN TO THE WEST LATE FRIDAY MORNING AS THE
LOW MOVES TO THE NORTHEAST OF THE FORECAST AREA. THE WEST WINDS
WILL PULL IN SOME DRIER AIR CAUSING VISIBILITIES AND CIGS TO
IMPROVE TO MVFR FRIDAY AFTERNOON AND EVENING.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR
CLINTON-JACKSON-SCOTT.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR BENTON-
BUCHANAN-CEDAR-DELAWARE-DUBUQUE-IOWA-JOHNSON-JONES-LINN-
MUSCATINE.
IL...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR BUREAU-
CARROLL-HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-
STEPHENSON-WHITESIDE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1142 PM CST THU FEB 21 2013
.UPDATE...
HAVE LOWERED SNOW AMOUNTS WITH THE EVENING UPDATE. DSM RAP PROFILES
SHOW PLENTY OF MOISTURE UP TO AT LEAST 17KFT...BUT WITH ONLY A VERY
NARROW LAYER OF LIFT IN THE DENDRITIC GROWTH ZONE /DGZ/ NEAR THE TOP
OF THAT MOISTURE LAYER. THIS HAS RESULTED IN MUCH OF THAT UPWARD
VERTICAL MOTION IN TEMPS WARMER THAN -12C AND NON-DENDRITIC SNOW
CRYSTALS THAT HAVE NOT ACCUMULATED MUCH...AT LEAST IN WIDESPREAD
FASHION. HIGHEST TOTALS HAVE FALLEN SOUTH AND WEST OF DSM METRO
AREA. RAP INDICATES ANOTHER FINAL SURGE OF LIFT IN THE DGZ WITH THE
NW-SE ORIENTED RADAR BAND AND COOLER CLOUD TOPS MOVING THROUGH SRN
IA RIGHT NOW. LIGHT SNOW OR FLURRIES ARE THEN EXPECTED TO LINGER
INTO FRIDAY MORNING WITH GENERAL AMOUNTS NOW 4-6 INCHES. EVEN THIS
MAY BE TOO MUCH...BUT DO NOT WANT TO GET TOO AGGRESSIVE TRIMMING
AMOUNTS. WITH BORDERLINE AMOUNTS UP TO 6 INCHES...WILL ALSO LEAVE
WARNING IN PLACE. NOTHING TO GAIN BY DOWNGRADING AT THIS POINT.
&&
.SHORT TERM /TONIGHT/...
SNOW BAND ADVECTING NORTHWARD ACROSS MUCH OF THE FORECAST AREA THIS
AFTERNOON INTO THE EVENING CAUSING RAPIDLY DETERIORATING CONDITIONS.
MODELS REMAIN IN GREAT AGREEMENT WITH TIMING AND PLACEMENT OF
HEAVIEST BAND TONIGHT AND WITH THE UPPER LOW TRACK DURING THE
OVERNIGHT HOURS. LEANED TOWARD THE TIMING OF NAM12/HRRR/HIRES
ARW-WRF FOR BAND DURING THE EVENING HOURS AND SREF/NAM OVERNIGHT.
IMPRESSIVE ISENTROPIC LIFT AHEAD OF THE UPPER LOW...GENERALLY ALONG
THE 285K TO 305K ISENTROPIC SURFACES...COMBINED WITH GOOD MOISTURE
TRANSPORT WILL CONTINUE TO PUSH THE CURRENT SNOW BAND FURTHER NORTH
LATE THIS AFTERNOON AND EVENING. THE ISENTROPIC LIFT DIMINISHES IN
STRENGTH AS THE UPPER LOW APPROACHES FROM KANSAS LATER TONIGHT INTO
THE OVERNIGHT HOURS BUT ENOUGH DEEP FORCING ASSOCIATED WITH IT AS IT
PASSES THROUGH THE STATE TO KEEP HIGH POPS GOING OVERNIGHT.
ALSO...EXPECTING THE SNOW TO CONTINUE TO FILL IN ACROSS SOUTHWEST
IOWA AND REMAIN FAIRLY PERSISTENT ACROSS THE FORECAST AREA FOR
SEVERAL HOURS TONIGHT. RAP CONFIRMS THIS AS IT HAS MAX OMEGA WITHIN
THE DENDRITIC LAYER PERSISTING THROUGH 02Z AT DSM...AND THROUGH 06Z
ACROSS NORTH CENTRAL IOWA. EVEN WITH SNOW INTENSITIES
DIMINISHING...STILL EXPECTING LIGHTER SNOWFALL ACCUMULATIONS B/T 06Z
AND 12Z FRIDAY WITH PASSAGE OF THE UPPER LOW. LEANED TOWARD A BLEND
OF THE GFS/NAM FOR QPF AMOUNTS AND STILL ON TRACK FOR GOOD SWATH OF
6 TO 9 INCHES GENERALLY SOUTH OF HIGHWAY 20. SLIGHTLY LESS FURTHER
NORTH AS THE BEST FORCING SKIRTS TO ITS SOUTHEAST.
SHARP PRESSURE GRADIENT ACROSS THE STATE KEEPS EAST TO NORTHEAST
WINDS GUSTS THROUGH 03-06Z TONIGHT BEFORE DIMINISHING. 925MB WINDS
AT 03Z STILL GUSTING AT 30KTS OVER CENTRAL PORTION OF THE FORECAST
AREA. VISIBILITY RAPIDLY DIMINISHING WITH THE ONSET OF THE SNOW AND
WILL PERSIST BEFORE THE WINDS WEAKEN LATER THIS EVENING.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
UPPER LOW WILL BE DEPARTING TO THE NORTHEAST ON FRIDAY WITH FORCING
SUBSIDING THROUGH THE DAY. HAVE CONTINUED CATEGORICAL WORDING IN
THE FAR NORTHEAST DURING THE MORNING WITH A DECENT GRADIENT TO
ESSENTIALLY NO PCPN IN FAR SOUTHWEST. SUBSIDENCE WILL CONTINUE TO
OVERSPREAD THE AREA DURING THE DAY AND HAVE CUT THE POPS OFF ACROSS
THE SOUTH BY AFTERNOON AND LEFT SCATTERED SNOW SHOWERS AND FLURRIES
IN THE NORTH UNDER THE UPPER LOW WHERE SOME WEAK LIFT WILL CONTINUE
TO RESIDE. THE THREAT OF ANY PCPN WILL END BY SATURDAY NIGHT IN THE
NORTH AS THE SYSTEM PULLS AWAY. THE 850MB THERMAL TROF IS NEARLY
ASSOCIATED WITH THE UPPER LOW SO WARM ADVECTION WILL COMMENCE
IMMEDIATELY ON FRIDAY NIGHT INTO SATURDAY ON BACKSIDE OF THE SYSTEM.
THIS WILL KEEP TEMPERATURES FROM DROPPING AS MUCH AS WOULD BE
EXPECTED WITH FRESH SNOW COVER WITH HIGHS ON SUNDAY APPROACHING OR
SLIGHTLY ABOVE FREEZING.
FOCUS WILL THEN SHIFT ON SHORTWAVE DROPPING INTO THE ROCKIES DURING
THE WEEKEND. GFS IS FARTHER NORTH AND FASTER WITH THE EVOLUTION OF
THIS SYSTEM AND APPEARS TO BE THE ODD MODEL OUT. THE EURO AND GEM
HAVE BEEN MORE CONSISTENT DIGGING THE SYSTEM THROUGH THE
INTERMOUNTAIN WEST THEN MOVING THE STORM EASTWARD THROUGH THE MID
MISSISSIPPI RIVER VALLEY. THE IMPLICATIONS OF THIS WOULD BE TO KEEP
THE BULK OF FORCING AND MOISTURE TO OUR SOUTH WITH MISSOURI SEEING
THE WORST CONDITIONS. HOWEVER...SOME WEAKER FORCING WILL BLEED INTO
THE STATE AS THE UPPER TROF IS ELONGATED FROM THE CENTRAL INTO THE
NORTHERN PLAINS. THEREFORE...SOME SNOWFALL IS STILL EXPECTED ACROSS
THE STATE FROM LATE SUNDAY NIGHT INTO TUESDAY MORNING...PRIMARILY
IMPACTING THE SOUTHERN HALF OF IOWA. SOME LIGHT TO MODERATE
ACCUMULATIONS ARE EXPECTED WITH THIS STORM AND WILL CONTINUE TO
MONITOR THE TRACK SINCE ANY NORTHWARD SHIFT WOULD BEGIN TO BRING
SIGNIFICANTLY HIGHER AMOUNTS INTO THE STATE. AFTER THIS SYSTEM
PULLS AWAY...DRIER CONDITIONS ARE EXPECTED WITH TEMPERATURES BELOW
NORMAL WITH COOL NORTHERLY FLOW BEHIND THE SYSTEM.
&&
.AVIATION...22/06Z
NARROW BAND OF LIFR SNOW JUST EXITING KDSM/KOTM WILL MOVE THROUGH
KFOD SHORTLY. AT LEAST IFR CONDITIONS WILL ALSO AFFECT KMCW/KALO
FOR SEVERAL HOURS EARLY FRI AS WELL AS LAST BAND OF HEAVIER SNOW
MOVES NORTHWARD. THIS WILL BE FOLLOWED BY MVFR/IFR CIGS UPSTREAM
INTO KS AND MO...ALONG WITH LIGHT SNOW AND FLURRIES THROUGH AT LEAST
FRI MORNING. MODELS SUGGEST STRATUS WILL PERSIST THROUGH MUCH OF
THE PERIOD AS WELL...ALTHOUGH CONFIDENCE IN MVFR OR IFR IS LOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST FRIDAY FOR
ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-
CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-MADISON-
MAHASKA-MARION-MONROE-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE-BLACK HAWK-BREMER-BUTLER-CERRO GORDO-EMMET-
FRANKLIN-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MARSHALL-
PALO ALTO-POCAHONTAS-TAMA-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
UPDATE/AVIATION...SMALL
SHORT TERM...KLP
LONG TERM...COGIL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1129 PM CST THU FEB 21 2013
...UPDATE TO AVIATION...
.DISCUSSION...
TONIGHT THROUGH FRIDAY...
THE UPPER LEVEL LOW WAS LOCATED ACROSS THE NORTHEAST TEXAS PANHANDLE
THIS AFTERNOON. ONE 1.5PV ANOMALY WAS LIFTING NORTHWARD ACROSS WEST
CENTRAL KS...WITH A SECOND 1.5PV ANOMALY OVER WESTERN OK. THE
SHORT-TERM MODELS...HRRR AND RAP SHOW THE 1.5PV ANOMALY
LIFTING NORTHEAST ACROSS EASTERN KS. AHEAD OF THE 1.5PV ANOMALY THE
FRONTOGENETICAL FORCING SHOULD INCREASE TO PROVIDE A PERIOD OF LIGHT
SNOW. THE MODELS SHOW AN INCREASE IN THE NEGATIVE SATURATED
EPV...CSI...WHICH COULD CAUSE SOME SLIGHTLY HEAVIER SNOW
BANDS...THUS THE WESTERN AND CENTRAL COUNTIES OF THE CWA COULD SEE
SOME LOCALLY HIGHER SNOW AMOUNTS.
UNTIL THE DENDRITIC GROWTH ZONE SATURATES LATER THIS AFTERNOON
THERE MAY BE PERIODS OF FREEZING DRIZZLE ACROSS THE EASTERN HALF OF
THE CWA. THE PATCHY FREEZING DRIZZLE MAY REFORM LATER THIS EVENING
ONCE THE STRONGER ASCENT SHIFTS NORTHEAST OF THE CWA. ISENTROPIC
DOWN GLIDE SHOULD BRING AN END THE THE FREEZING DRIZZLE CHANCE AFTER
MIDNIGHT.
THE STORM TOTAL SNOWFALL WILL RANGE FROM 6 TO 15 INCHES WITH SOME
LOCALLY HIGHER AMOUNTS.
I WILL KEEP THE WINTER STORM WARNING IN EFFECT UNTIL 00Z FOR THE
WESTERN HALF OF THE CWA AND UNTIL MIDNIGHT FOR THE EASTERN HALF OF
THE CWA.
FRIDAY...THE SKIES SHOULD BEGIN TO CLEAR FROM WEST TO EAST ACROSS
THE CWA THROUGH THE MID AND LATE MORNING HOURS. HIGHS WILL CONTINUE
TO BE COLD WITH MID 20S...GIVEN SEVERAL INCHES OF SNOW COVER.
GARGAN
FRIDAY NIGHT THROUGH THURSDAY...
DRY CONDITIONS ARE EXPECTED FOR THE START OF THE WEEKEND AS THE
UPPER LEVEL TROUGH THAT IMPACTED THE REGION WITH WINTER WEATHER
TODAY SLIDES NORTH TOWARD THE GREAT LAKES REGION. SURFACE HIGH
PRESSURE BRIEFLY WILL SETTLE INTO THE REGION BEHIND THE EXITING
STORM SYSTEM BEFORE THE NEXT UPPER LEVEL TROUGH BEGINS TO DIG
SOUTHWARD ACROSS THE NORTHERN AND CENTRAL PLAINS DURING THE LATTER
PART OF THE WEEKEND. THERE IS STILL UNCERTAINTY AMONGST THE MODELS
REGARDING JUST HOW FAR SOUTH THIS TROUGH WILL DIG ALONG AND EAST OF
THE ROCKY MOUNTAINS AND HOW QUICKLY THE UPPER LOW EJECTS
NORTHEASTWARD ACROSS THE FORECAST AREA AND FURTHER EAST OF THE AREA.
THESE MODEL DISCREPANCIES LEAD TO DIFFICULTIES IN PINNING DOWN THE
TIMING OF ANY PRECIPITATION FROM THIS SYSTEM. MODELS SEEM TO BE A
BIT SLOWER IN BRINGING THE SYSTEM INTO THE AREA...SO HAVE DECREASED
POPS FOR SUNDAY WITH CHANCE POPS FOR THE SUNDAY NIGHT THROUGH MONDAY
NIGHT TIME FRAME. THESE POPS BEST REFLECT A BLEND OF THE ECMWF/GEM.
THE GFS CURRENTLY IS AN OUTLIER IN KEEPING THE UPPER TROUGH FURTHER
NORTH AND ONLY HAVING PRECIPITATION SKIMMING ACROSS THE NORTHERN
PORTION OF THE FORECAST AREA. DEPENDING UPON THE TIMING OF
PRECIPITATION...THE REGION COULD SEE A COMBINATION OF RAIN AND SNOW
SHOWERS WITH THIS SYSTEM. AT THIS TIME...THE SYSTEM LOOKS TO EXIT
EAST OF THE AREA BY TUESDAY. A WEAK RIDGE WILL MOVE INTO THE REGION
BEHIND THIS TROUGH WITH DRY CONDITIONS EXPECTED FOR MID-WEEK. BY THE
END OF THE PERIOD MODEL DISCREPANCIES EXIST WITH REGARDS TO THE NEXT
SHORTWAVE THAT EJECTS INTO THE CENTRAL PLAINS. KEPT ANY MENTION OF
PRECIPITATION OUT OF THE FORECAST AT THIS TIME.
TEMPERATURE FORECASTS FOR THE PERIOD HAVE BEEN COMPLICATED BY THE
SEVERAL INCHES OF SNOW RECEIVED ACROSS THE FORECAST AREA FROM
TODAY`S STORM. WITH THIS IN MIND...HAVE TRENDED WITH TEMPERATURES
STAYING BELOW THE SEASONAL NORMALS THROUGH THE EXTENDED FORECAST
PERIOD...WITH HIGHS GENERALLY IN THE 30S. THE COLDEST NIGHT LOOKS TO
BE FRIDAY NIGHT/EARLY SATURDAY MORNING AS LOW TEMPERATURES PLUMMET
INTO THE SINGLE DIGITS...WITH WIND CHILL VALUES ANYWHERE FROM ZERO
TO 8 BELOW ZERO. OTHERWISE...LOWS GENERALLY LOOK TO BE IN THE TEENS
AND 20S. TEMPERATURE FORECASTS WILL NEED TO BE ADJUSTED DEPENDING
UPON ANY MELTING OF SNOW THAT OCCURS IN THE UPCOMING DAYS.
ACH
&&
.AVIATION...
SNOW SHOWERS COMING TO AN END ACROSS THE AREA. EXPECT FLURRIES TO
HOLD ON FOR A COUPLE MORE HOURS BEFORE MOVING OUT OF THE AREA.
KMHK CURRENTLY SHOWS A VFR OB...HOWEVER GIVEN SEVERAL OBS IN THE
AREA WITH CIGS AROUND 1500 FEET HAVE INTRODUCED A TEMPO FOR MVFR
CIGS AT KMHK. VFR CIGS LOOK TO MOVE INTO THE AREA AROUND 10-12Z AT
ALL TERMINALS JUDGING BY OBSERVATIONS AND TIME OF ARRIVAL TOOL OF
HIGHER CIGS. WILL AMEND AS NECESSARY TO ADJUST TIMING.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
434 AM EST FRI FEB 22 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY WEAKEN OVER THE REGION THROUGH
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE CENTRAL GULF COAST
STATES. THE LOW WILL TRACK NORTHEAST TO OFF THE VIRGINIA COAST
TONIGHT THROUGH SATURDAY. HIGH PRESSURE RETURNS TO THE MID
ATLANTIC STATES SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HI PRES (NR 1030MB) RMNS WEDGED OVR THE FA...RESULTING IN MDT
CAD. DEWPTS RMN IN THE TEENS OVR THE FA ATTM. PCPN SPREADING EWD
THROUGH SW VA AND WRN/CNTRL NC AS WEAKENING MID LVL S/W MOVES INTO
THE CNTRL MTNS. THE PCPN IS ENCOUNTERING THE SUBSTANTIAL LO LVL
DRY AIR IN PLACE THIS FAR E OF THE MTNS. ADDITIONALLY...RECENT
TRENDS IN RADAR SUGGEST THAT THE GFS/RUC IDEA OF A SPLIT IN THE
PCPN (ONE AREA PUSHING N INTO NRN WV/NW VA AND WRN PA...THE OTHER
MOVING E ACRS NC/EXTREME SW VA) IS CORRECT. SO FAR...ROA/LYH AND
HSP HAVE RECEIVED NO PCPN...AND THAT MAY SUGGEST THAT ANY
WIDESPREAD PCPN WILL BE DIFFICULT TO REACH CNTRL AND ERN VA
THROUGH THE ERY MRNG/MIDDAY HRS. 00Z GFS AND 03Z RUC BOTH ONLY
BRING ABT A HUNDREDTH OR TWO INTO CNTRL AND NRN SECTIONS OF THE
FA...W/ HIGHEST QPF (THOUGH ONLY TO ABT 0.05" ON AVG) TO AREAS
NR/S OF THE VA/NC BORDER IN INTR SRN VA/NE NC. MDL SNDGS HAVE
SUBSTANTIAL DRYING AOA 700MB BY MID/LT MRNG HRS ACRS THE FA...AND
CONT THAT THROUGH THE AFTN...POINTING TO ONLY LGT/SPOTTY PCPN ACRS
THE FA AS TEMPS RISE ABV FRZG (LASTLY PTNTLLY OVR THE FAR NW PDMNT
CTYS WHERE TEMPS XPCD TO HOVER NR FRZG ALL DAY).
PTYPE IS THE OTHER CONCERN...WILL HAVE CHCS FOR SN/IP AS WELL AS
FRZG RA (AGN AMTS VRY LGT...AND INCRSGLY SPOTTY THROUGH THE
ERY/MID MRNG HRS). WILL KP WINTER WX ADSVRY AS IS FOR NOW...AND
MONITOR TRENDS THROUGH ERY MRNG. ANY ACCUMS (ESP ICE)...GENLY AOB
0.01-0.02". SPOTTY LGT RA AND/OR DZ FM MIDDAY THROUGH THE AFTN
HRS...AGN QPF QUITE LGT (LESS THAN 0.05") THROUGHOUT.
HI TEMPS FM NR 32F FAR NW TO L40S FAR SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
HIGHER CONFIDENCE/PROB FOR PCPN TNGT FM SW TO NE AS LO PRES FM
THE CNTRL GULF STATES TRACKS NE THROUGH GA/SC/NC. INCRSD POPS TO
80-100% ACRS MUCH OF THE AREA OVRNGT...W/ 60-80% FAR NNE SECTIONS.
HI PROB (90-100% POPS) OVR ENTIRE FA SAT MRNG. THE LO REACHES OFF
THE VA CST SAT AFTN/EVE LEADING TO A GRADUAL LWRG OF POPS FM WSW
TO E (THOUGH CLDNS WILL HANG ON). STM TOTAL QPF RANGING FM
0.25-0.50" NW TO 1-1.5" SE. TEMPS HOLD NRLY STEADY OR ONLY RISE A
CPL/FEW DEGS F INLAND...WHILE CLOSE TO THE CST...ESP SE VA/NE
NC...TEMPS RISE INTO/THROUGH THE 40S. HI TEMPS SAT M40S NW TO
M/U50S SE VA/NE NC.
SLOLY DRYING OUT BY LT SAT NGT/ERY SUN. SFC HI PRES BUIDS TWD THE
RGN FM THE NW ON SUN LEADING TO SUBSTANTIAL CLRG (AND MNLY SUNNY)
AND MILD CONDS. HI TEMPS 50-55F N TO 55-60F S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE BUILDS IN FROM THE WEST ON SUNDAY WITH DRY CONDITIONS
INTO SUNDAY NIGHT. A NEGATIVELY TILTED UPPER LEVEL RIDGE AMPLIFIES
OVER THE REGION ON MONDAY IN RESPONSE TO A BROAD UPPER LEVEL TROUGH
DIGGING OVER THE CTRL PLAINS. WEAK ENERGY FLOWING AROUND THE BASE OF
THE AFOREMENTIONED TROUGH IS EXPECTED TO MOVE NE ACROSS THE SE
STATES AS SW FLOW DEVELOPS ALOFT. THIS ENERGY AND ASSOCIATED
PRECIPITATION (ALL RAIN) IS THEN EXPECTED TO MOVE THROUGH THE MID
ATLANTIC REGION MONDAY NIGHT INTO TUESDAY. THERE WERE INDICATIONS OF
A COASTAL LOW DEVELOPING TUESDAY NIGHT ONCE IT MOVES OVER THE WATER
AND THIS TREND HAS CONTINUED...HOWEVER THERE ARE NOW MORE ADVERSE
TIMING DIFFERENCES BTWN VARIOUS 12Z MODEL RUNS. WILL TREND THE
FORECAST BTWN THE TWO MODELS FOR THE TIME BEING. A BROAD UPPER
TROUGH BECOMES ANCHORED OVER THE NE CONUS THE REMAINDER OF THE
WEEK...KEEPING CONDITIONS COOL AND UNSETTLED.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
SHORTWV ENERGY WILL PUSH ACRS THE AREA THIS MORNG INTO EARLY THIS
AFTN...AND MAY BRING A MIX OF LIGHT SLEET...SNOW OR FREEZING RAIN.
OTHRWISE...CLDS WILL THICKEN AND LWR DURING TODAY...AS WINDS
BECOME ESE WELL AHEAD OF LO PRES DEVELOPING OVR THE GULF CST
STATES. MVFR/IFR CIGS/VSBYS THEN LIKELY THIS EVENG INTO SAT
NGT...AS THE LO MOVES UP ALNG AND JUST OFF THE CST...BRINGING
RAIN TO THE AREA. DRY/VFR CONDITIONS RETURN SUN INTO MON...AS
HI PRES BLDS IN FM THE W.
&&
.MARINE...
NO HEADLINES IN THE MARINE AREA THRU TNGT...BUT WILL LIKELY NEED
TO ISSUE SCA`S FOR AT LEAST THE CHES BAY AND CSTL ZNS FOR SAT INTO
EARLY SUN...DUE TO LO PRES MOVNG UP ALNG AND JUST OFF THE CST. N
WINDS 10 TO 15 KT EARLY THIS MORNG...WILL BECOME ESE 10 KT OR LESS
THIS AFTN. ESE WINDS 10 TO 20 KT AND GUSTY THEN EXPECTED LATER
TNGT INTO SAT AFTN...THEN BECOME NW 10 TO 20 KT AND GUSTY FOR SAT
NGT THRU SUN...AS THE LO MOVES AWAY TO THE NE AND HI PRES BLDS IN
FM THE WNW. HI PRES WILL BLD INTO AND OVR THE REGION FOR LATER SUN
INTO MON.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NCZ012-013-030.
VA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VAZ092.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ060-
065>067-079-080-087-088.
MARINE...NONE.
&&
$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...TMG
MARINE...TMG
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
358 AM EST FRI FEB 22 2013
.SYNOPSIS...
HIGH PRESSURE IS MOVING OFF THE COAST...AHEAD OF AN APPROACHING LOW
PRESSURE SYSTEM FROM THE MIDWEST. A COASTAL LOW PRESSURE SYSTEM
WILL IMPACT THE AREA SATURDAY BEFORE HIGH PRESSURE RETURNS SUNDAY
INTO THE EARLY PART OF NEXT WEEK. LOW PRESSURE WILL AFFECT THE
AREA DURING THE MID PART OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
THIS IS A VERY TRICKY FCST. AS I HV WRITTEN THE PAST TWO NGTS IN MY
DSCN THIS IS NOT A TYPICAL SYNOPTIC SET UP FOR FZRA WHERE HIGH PRES
IS CAMPED OUT OVR NY STATE AND COLD DRY AIR ON NRLY WINDS IS BEING
FED INTO THE MID ATLC ON THE E SIDE OF THE APLCHNS WHILE MOISTURE
STREAMS UP FM THE S. TNGT THERE IS A STRONG AREA OF HIGH PRES...BUT
IT IS CENTERED OVR MOOSONEE ON THE S SHORE OF JAMES BAY. THE S SIDE
OF THAT HIGH WL BE MOVG OFFSHORE THIS AFTN...MOST LKLY THE LOW LVL
WINDS E OF THE APLCHNS WL BE FM THE SE. AGN THIS IS NOT FAVORABLE
FOR LO LVL CAD AND FZN/FRZG PCPN. IN ADTN DWPTS ARE STILL IN THE M
TEENS. THE ATMOSPHERIC COLUMN IS GOING TO REQUIRE SOME TIME TO
MOISTEN.
ATTM THE MOISTURE ATTEMPTING TO SPREAD NEWD IS RUNNING INTO THAT
HIGH PRES RDG.
ANOTHER CONSIDERATION WL BE SFC TEMPS TDA. THE TEMPS I INHERITED
WERE IN MANY CASES SVRL DEGS BLO WHAT ANY 00Z MDL GDNC WAS
PRESENTING. THERE ARE CASES WHERE THAT IS THE RIGHT WAY TO GO...BUT
DURG FEB I`D ESTIMATE THAT 1ST PD MDL TEMP VERIFICATION HAS BEEN TOO
WARM ABT 65-70% OF THE TIME. SO BTWN THAT HISTORY AND THAT THE HIGH IS NOT
IN A POSN TO HOLD IN CD AIR I`VE TAKEN TEMPS E OF THE MTNS UP SVRL
DEGS FOR TDA...WHICH OF COURSE IS A BIG DEAL WHEN U R CLOSE TO FRZG
W/ PCPN APRCHG.
HIGHS WON`T CHG A LOT TDA FM MRNG TEMPS - M30S E OF THE BLUE
RDG...MU30S IN THE CITIES. W/ THE XPCTN OF AT HIGHER ELEVS WE
ACTUALLY HV THE ENTIRE CWA AOA FRZG. THIS WL NOT PRECLUDE THE PSBLTY
OF IP/S...BUT LIMITS THE THREAT OF FZRA WHICH IS OF COURSE THE
BIGGEST TRAVEL CONCERN. BECAUSE OF THE HIGHER ELEVS GOING SUB FRZG
IT IS LKLY THAT WE WL NEED TO BE ISSUING A WINT WX ADVSRY. SEE
COUNTIES AT BOTTOM OF THIS PRODUCT OR ON OUR WEB SITE. HOWEVER AT
THIS TIME WE DO NOT FORESEE THE NEED FOR ONE IN THE DC/BALT RGN TDA.
AND YET ANOTHER CONSIDERATION IS HOW MUCH PCPN IS GOING TO RCV. 21Z
SREF...01Z HRRR AND 00Z ECM REALLY TEAR THE PCPN APART WHEN IT TRIES
TO MOVE E OF THE MTNS. BUT THE COMP RDR IS SHOWING HIGHER REF OVR
SWRN VA...HOWEVER THE HIGHER REFLECTIVITIES ARE QUITE PSBLY DUE TO
BRIGHT BANDING.
&&
.SHORT TERM /TONIGHT/...
IN BOTH PDS THE MAIN CONCERN IS WHETHER WE NEED TO ISSUE AN ADVSRY
AS WELL AS WHERE. TNGT LOOKS LK ANOTHER BORDERLINE SITUATION WHERE
ADVSORIES MAY BE REQUIRED...BUT WE ARE PUTTING OUR MENTAL ENERGIES
ON TRYING TO SOLVE THE TDA PD AND BUY THE DAYSHIFT SOME TIME TO
ATTEMPT TO FIGURE OUT IF HEADLINES ARE NEEDED TNGT. AGN IT LOOKS LK
IF THESE ARE NEEDED THE WRN PART OF THE CWA HAS THE BEST BET AS
TEMPS E OF THE BLUE RDG WL BE XTRMLY MARGINAL.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
SRN STREAM JET INCREASES AND SPREADS EAST ACROSS THE E-CNTRL CONUS
SATURDAY AHEAD OF AN UPR TROUGH AXIS REACHING THE MID-SOUTH STATES
BY THE EVENING BEFORE CROSSING THE MID-ATLANTIC SATURDAY NIGHT. A
COASTAL LOW WILL DEVELOP NEAR THE NC/VA BORDER MIDDAY SATURDAY AND
SPREAD NORTHEAST OFF THE DELMARVA THROUGH THE EVENING. STRATIFORM
RAIN AHEAD OF THIS LOW LOOKS TO OVERSPREAD THE AREA MAINLY EAST FROM
THE BLUE RIDGE SATURDAY MORNING...THEN CONTRACT AND PULL NORTHEAST
AS THE LOW DEVELOPS AND MOVES OFF.
SATURDAY...MIN TEMPS WILL PLAY A MAJOR ROLE WHETHER PRECIP STARTS
OFF AS FREEZING OR PLAIN RAIN. AS OF NOW FAR NW BALT-WASH SUBURBS
LOOK TO BE RIGHT AROUND 32F SO POCKETS OF FREEZING RAIN ARE POSSIBLE
THERE AND THE BLUE RIDGE WEST TO THE POTOMAC HIGHLANDS. THIS ICY
SCENARIO COULD LAST THROUGH THE MID MORNING HOURS. OTHERWISE PLAIN
RAIN.
SATURDAY NIGHT...PRECIP PULLS OUT OF THE AREA TO THE NORTHEAST WITH
THE LOW. THE UPPER TROUGH AXIS PUSHES THROUGH FROM THE WEST LATE IN
THE NIGHT...SO 30 POP AND WHAT THERMALLY WOULD BE SNOW SHOWERS OR
FLURRIES WERE ADDED FOR THE NORTHEASTERN 2/3 OF THE LWX CWA. THIS IS
A FAIRLY LOW CONFIDENCE FORECAST /NO MODEL ACTUALLY PRINTS OUT
PRECIP OVER LWX/ AND THE DAY SHIFT WILL HAVE TO ANALYZE THIS
POTENTIAL FURTHER. PERHAPS FLURRY WORDING WOULD BE BETTER.
SUNDAY AND MONDAY...SFC HIGH PRESSURE BUILDS OVERHEAD WITH AT OR
JUST ABOVE NORMAL TEMPERATURES AND DRY WEATHER. NWLY GUSTS ON SUNDAY
LOOK TO BE IN THE 30 TO 35 MPH RANGE.
THE NEXT ACTIVE WEATHER COMES IN A SIMILAR PATTERN TO THE CURRENT
LOW SYSTEM WITH A CNTRL CONUS LOW DEVELOPING AND OCCLUDING OVER THE
MIDWEST AS A LEADING WAVE APPROACHES THE MID-ATLANTIC. TIMING IS
UNCERTAIN AS SHOWN BY OPERATIONAL 00Z ECMWF/GFS OFF BY ABOUT 12 HRS
/GFS QUICKER AND MORE MONDAY NIGHT WHILE ECMWF IS TUESDAY FOR
PRECIP/. SFC LOW DEVELOPMENT ALONG THE LEADING WAVE LOOKS LIKELY SO
P-TYPE IS QUITE UNCERTAIN AS OF NOW. MAINTAINED LOOK OF RAIN OR SNOW
FOR ALL AREAS OUTSIDE OF SRN MD WHICH SEEMS REASONABLE.
THE OCCLUDED LOW THEN PERSISTS INTO THE LATER PARTS OF NEXT
WEEK...POSSIBLY BRINGING MORE ACTIVE WEATHER TO THE MID-ATLANTIC.
EXTENDED GRIDS LEFT ALONE TONIGHT.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
CIGS CURRENTLY IN VFR RANGE. THESE ARE XPCTD TO LOWER DURG THE
DAY..DROPPING INTO LIFR AT CHO BY MID AFTN...AND IAD/DCA LATE THIS
AFTN. FRUTHER LOWERING PSBL THIS EVE AS A LGT WINTRY MIX OF PCPN
OVERPREADS THE RGN.
IFR A SURE BET FOR SATURDAY AS SLY FLOW BRING LOW CLOUDS AND RAIN TO
THE TERMINALS. PRECIP PUSHES OUT TO THE NORTHEAST SATURDAY EVENING
WITH POTENTIAL FOR SOME FLURRIES LATE IN THE NIGHT. NWLY GUSTS 25 TO
30 KT EXPECTED BEHIND THE COLD FRONT ON SUNDAY. VFR MONDAY UNDER
HIGH PRESSURE THEN NEXT ACTIVE WEATHER RAIN OR POSSIBLE MIX MONDAY
NIGHT OR TUESDAY.
&&
.MARINE...
WINDS BLO DCA VALUES TDA AND TNGT.
SCA LIKELY NEEDED FOR SATURDAY MIDDAY AND ON FOR ONSHORE FLOW FROM
LOW CENTER CROSSING VA PORTION OF THE BAY. NWLY FLOW THEN STARTS
SATURDAY NIGHT AND GUSTY THROUGH SUNDAY. SCA THROUGH THIS TIME WITH
PEAK GUSTS AROUND 30 KT. TRANQUIL ON MONDAY IN ADVANCE OF THE NEXT
WEATHER MONDAY NIGHT OR TUESDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ501-
502.
VA...WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR
VAZ025>027-029-036>040-503-504.
WV...WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ050-
055-501>506.
MARINE...NONE.
&&
$$
PRODUCTS...WOODY!/BAJ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
349 AM EST FRI FEB 22 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY WEAKEN OVER THE REGION THROUGH
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE CENTRAL GULF COAST
STATES. THE LOW WILL TRACK NORTHEAST TO OFF THE VIRGINIA COAST
TONIGHT THROUGH SATURDAY. HIGH PRESSURE RETURNS TO THE MID
ATLANTIC STATES SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HI PRES (NR 1030MB) RMNS WEDGED OVR THE FA...RESULTING IN MDT
CAD. DEWPTS RMN IN THE TEENS OVR THE FA ATTM. PCPN SPREADING EWD
THROUGH SW VA AND WRN/CNTRL NC AS WEAKENING MID LVL S/W MOVES INTO
THE CNTRL MTNS. THE PCPN IS ENCOUNTERING THE SUBSTANTIAL LO LVL
DRY AIR IN PLACE THIS FAR E OF THE MTNS. ADDITIONALLY...RECENT
TRENDS IN RADAR SUGGEST THAT THE GFS/RUC IDEA OF A SPLIT IN THE
PCPN (ONE AREA PUSHING N INTO NRN WV/NW VA AND WRN PA...THE OTHER
MOVING E ACRS NC/EXTREME SW VA) IS CORRECT. SO FAR...ROA/LYH AND
HSP HAVE RECEIVED NO PCPN...AND THAT MAY SUGGEST THAT ANY
WIDESPREAD PCPN WILL BE DIFFICULT TO REACH CNTRL AND ERN VA
THROUGH THE ERY MRNG/MIDDAY HRS. 00Z GFS AND 03Z RUC BOTH ONLY
BRING ABT A HUNDREDTH OR TWO INTO CNTRL AND NRN SECTIONS OF THE
FA...W/ HIGHEST QPF (THOUGH ONLY TO ABT 0.05" ON AVG) TO AREAS
NR/S OF THE VA/NC BORDER IN INTR SRN VA/NE NC. MDL SNDGS HAVE
SUBSTANTIAL DRYING AOA 700MB BY MID/LT MRNG HRS ACRS THE FA...AND
CONT THAT THROUGH THE AFTN...POINTING TO ONLY LGT/SPOTTY PCPN ACRS
THE FA AS TEMPS RISE ABV FRZG (LASTLY PTNTLLY OVR THE FAR NW PDMNT
CTYS WHERE TEMPS XPCD TO HOVER NR FRZG ALL DAY).
PTYPE IS THE OTHER CONCERN...WILL HAVE CHCS FOR SN/IP AS WELL AS
FRZG RA (AGN AMTS VRY LGT...AND INCRSGLY SPOTTY THROUGH THE
ERY/MID MRNG HRS). WILL KP WINTER WX ADSVRY AS IS FOR NOW...AND
MONITOR TRENDS THROUGH ERY MRNG. ANY ACCUMS (ESP ICE)...GENLY AOB
0.01-0.02". SPOTTY LGT RA AND/OR DZ FM MIDDAY THROUGH THE AFTN
HRS...AGN QPF QUITE LGT (LESS THAN 0.05") THROUGHOUT.
HI TEMPS FM NR 32F FAR NW TO L40S FAR SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
HIGHER CONFIDENCE/PROB FOR PCPN TNGT FM SW TO NE AS LO PRES FM
THE CNTRL GULF STATES TRACKS NE THROUGH GA/SC/NC. INCRSD POPS TO
80-100% ACRS MUCH OF THE AREA OVRNGT...W/ 60-80% FAR NNE SECTIONS.
HI PROB (90-100% POPS) OVR ENTIRE FA SAT MRNG. THE LO REACHES OFF
THE VA CST SAT AFTN/EVE LEADING TO A GRADUAL LWRG OF POPS FM WSW
TO E (THOUGH CLDNS WILL HANG ON). STM TOTAL QPF RANGING FM
0.25-0.50" NW TO 1-1.5" SE. TEMPS HOLD NRLY STEADY OR ONLY RISE A
CPL/FEW DEGS F INLAND...WHILE CLOSE TO THE CST...ESP SE VA/NE
NC...TEMPS RISE INTO/THROUGH THE 40S. HI TEMPS SAT M40S NW TO
M/U50S SE VA/NE NC.
SLOLY DRYING OUT BY LT SAT NGT/ERY SUN. SFC HI PRES BUIDS TWD THE
RGN FM THE NW ON SUN LEADING TO SUBSTANTIAL CLRG (AND MNLY SUNNY)
AND MILD CONDS. HI TEMPS 50-55F N TO 55-60F S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE BUILDS IN FROM THE WEST ON SUNDAY WITH DRY CONDITIONS
INTO SUNDAY NIGHT. A NEGATIVELY TILTED UPPER LEVEL RIDGE AMPLIFIES
OVER THE REGION ON MONDAY IN RESPONSE TO A BROAD UPPER LEVEL TROUGH
DIGGING OVER THE CTRL PLAINS. WEAK ENERGY FLOWING AROUND THE BASE OF
THE AFOREMENTIONED TROUGH IS EXPECTED TO MOVE NE ACROSS THE SE
STATES AS SW FLOW DEVELOPS ALOFT. THIS ENERGY AND ASSOCIATED
PRECIPITATION (ALL RAIN) IS THEN EXPECTED TO MOVE THROUGH THE MID
ATLANTIC REGION MONDAY NIGHT INTO TUESDAY. THERE WERE INDICATIONS OF
A COASTAL LOW DEVELOPING TUESDAY NIGHT ONCE IT MOVES OVER THE WATER
AND THIS TREND HAS CONTINUED...HOWEVER THERE ARE NOW MORE ADVERSE
TIMING DIFFERENCES BTWN VARIOUS 12Z MODEL RUNS. WILL TREND THE
FORECAST BTWN THE TWO MODELS FOR THE TIME BEING. A BROAD UPPER
TROUGH BECOMES ANCHORED OVER THE NE CONUS THE REMAINDER OF THE
WEEK...KEEPING CONDITIONS COOL AND UNSETTLED.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
SHORTWV ENERGY WILL PUSH ACRS THE AREA THIS MORNG INTO EARLY THIS
AFTN...AND MAY BRING A MIX OF LIGHT SLEET...SNOW OR FREEZING RAIN.
OTHRWISE...CLDS WILL THICKEN AND LWR DURING TODAY...AS WINDS
BECOME ESE WELL AHEAD OF LO PRES DEVELOPING OVR THE GULF CST
STATES. MVFR/IFR CIGS/VSBYS THEN LIKELY THIS EVENG INTO SAT
NGT...AS THE LO MOVES UP ALNG AND JUST OFF THE CST...BRINGING
RAIN TO THE AREA. DRY/VFR CONDITIONS RETURN SUN INTO MON...AS
HI PRES BLDS IN FM THE W.
&&
.MARINE...
TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OVER CANADA AND LOW
MOVING OVER THE THE NORTH ATLANTIC HAS CAUSED WINDS TO INCREASE TO
SCA CONDITIONS OVER THE BAY. INCLUDED BAY ZONES FROM WINDMILL
POINT TO THE MOUTH OF THE BAY IN A SHORT(UNTIL 06Z)SCA AS WINDS
WILL GUST TO AROUND 25 KT.
HIGH PRESSURE BUILDS IN FROM THE NW TONIGHT...BRINGING AN END TO SCA
NW WINDS OVER THE BAY AND COASTAL WATERS NORTH OF PARRAMORE
ISLAND BY LATE EVENING. WATERS BECOME QUIET AFTER MIDNIGHT AS NW
WINDS BECOME NRLY AND DIMINISH TO GENERALLY AOB 15 KT. ONSHORE
FLOW DEVELOPS ON FRI (AOB 10 KT) AS THE SFC HIGH SLIDES OFFSHORE
AND A COMPLEX LOW PRESSURE SYSTEM THE AREA FROM THE SW. A WINTRY
MIX OF PRECIPITATION IS EXPECTED FRI MORNING...TRANSITIONING TO
ALL RAIN DURING THE EARLY AFTN. WINDS BEING TO VEER TO THE S-SE
LATE FRI NIGHT/EARLY SAT MORNING AS THE ACTUAL LOW PRESSURE CENTER
MOVES INTO SRN WATERS...BRINGING WIDESPREAD MODERATE RAIN TO ALL
WATERS DURING THE DAY. ONGOING WAA PROCESSES AND STEADY RAIN WILL
LIKELY LIMIT MIXING OVER THE WATERS...HOWEVER SCA FLAGS ARE
POSSIBLE OVER THE SOUND...SRN CHES BAY...AND SRN COASTAL WATERS AS
THE LOW PASSES THROUGH THE REGION. BY SAT NIGHT...THE LOW MOVES
OFF THE MID ATLANTIC COAST AND DEEPENS INTO A COASTAL LOW THAT IS
EXPECTED TO TRACK NE UP THE ERN SEABOARD TWD MASSACHUSETTS. A
TIGHTENING PRESSURE GRADIENT LATE SAT NIGHT AND WEAK CAA MAY
RESULT IN SCA CONDITIONS OVER NRN PORTIONS OF CHES BAY AND COASTAL
WATERS...ESPECIALLY AS WINDS BECOME NW. FLAGS HAVE NOT BEEN ISSUED
FOR THIS SITUATION AND WILL NEED TO BE MONITORED. AS HIGH PRESSURE
BUILDS INTO THE REGION ON SUN...POTENTIAL SCA CONDITIONS WILL
DIMINISH AND WATERS WILL BECOME QUIET SUN NIGHT THROUGH MON.
&&
.TIDES/COASTAL FLOODING...
ESTOFS AND MDL GUIDANCE CONTINUE TO SHOW NEGATIVE ANOMALIES
OCCURRING DURING THE LOW TIDE CYCLE TODAY AND FRIDAY...SLOWLY
RISING TWD MLLW LEVELS INTO THE WEEKEND. TIDE LEVELS ARE STILL
RUNNING ABOUT ONE HALF FT TO POSSIBLY ONE FT BELOW MLLW.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NCZ012-013-030.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ060-
065>067-079-080-087-088.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VAZ092.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
ANZ630>632-634-650-652.
&&
$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...TMG
MARINE...TMG
TIDES/COASTAL FLOODING...AKQ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1205 AM EST FRI FEB 22 2013
.SYNOPSIS...
ISSUED AT 330 PM EST THU FEB 21 2013
SNOW WILL SPREAD NORTHEAST ACROSS THE AREA OVERNIGHT INTO FRIDAY
MORNING. A QUICK 1 TO 2 INCHES OF SNOW MAY AFFECT THE FRIDAY MORNING
COMMUTE. THIS WILL BE FOLLOWED BY A TRANSITION TO FREEZING DRIZZLE
LATER IN THE DAY. A CHANCE OF WINTRY PRECIPITATION WILL PERSIST
THROUGH SATURDAY NIGHT. THE NEXT CHANCES FOR PRECIPITATION WILL BE
MONDAY NIGHT AND TUESDAY...WHEN A MIX OF RAIN AND SNOW IS EXPECTED.
TEMPERATURES WILL MODERATE NEXT WEEK WITH HIGHS REACHING THE UPPER
30S.
&&
.UPDATE...
ISSUED AT 1022 PM EST THU FEB 21 2013
NO CHANGES TO THE HEADLINES. REGIONAL RADAR SHOWS A BAND OF
SNOW...ON THE LEADING EDGE...AND FREEZING RAIN MOVING NORTH ACROSS
INDIANA. THE NRN FRINGE IS THINNING AS IT MOVES NORTH AND WILL
LIKELY TAKE A WHILE TO GET TO THE SRN CWA. STILL LOOKING FOR PCPN
TO BEGIN AFTER 08-09Z SOUTH OF I-94 AND MOVE NORTH.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM EST THU FEB 21 2013
WILL BE ISSUING A WINTER WEATHER ADVISORY FOR OUR SOUTHERN CWFA TO
ACCOUNT FOR POSSIBLE BRIEF INTENSE SNOWFALL DURING THE FRIDAY
MORNING COMMUTE. CALIBRATED SREF GUIDANCE SHOWS GREATER THAN 1 INCH
PER HOUR SNOWFALL PROBABILITIES ACROSS OUR SOUTHERN COUNTY WARNING
AREA IN THE 12-15Z TIMEFRAME FRIDAY. ALSO LATEST GRR SNOWTOOL
GUIDANCE FROM THE RAP SUGGESTS THAT 1"/HR RATES WILL BE POSSIBLE
AFTER 10Z. ADVISORY WILL BE COMING OUT SHORTLY.
AFTER THIS INITIAL BURST OF SNOWFALL...AGREE WITH THE PREVIOUS
DISCUSSION THAT IMPACTS SHOULD BE MINOR. THE RESPONSIBLE SYSTEM
CURRENTLY IN THE PLAINS WILL FILL AS IT SHEARS NORTHEAST. BEHIND THE
NARROW BUT POTENTIALLY INTENSE BAND OF WARM ADVECTION SNOW...ALL BUT
THE EXTREME NORTHERN PART OF THE FORECAST AREA DESATURATES IN THE
DGZ DURING THE LATE MORNING...MEANING A TRANSITION TO FREEZING
DRIZZLE AND THEN POSSIBLY DRIZZLE AS SURFACE TEMPERATURES WARM. ICE
ACCUMULATION IS EXPECTED TO BE MINIMAL... ESPECIALLY WITH THE
MITIGATING EFFECTS OF SNOW COVER...RESIDUAL SALT...AND DAYTIME
INSOLATION ALL DISCUSSED IN THE PREVIOUS AFD.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM EST THU FEB 21 2013
A HIGH PRESSURE RIDGE WILL PRODUCE DRY WX WITH SEASONABLY COOL
TEMPERATURES SUNDAY THROUGH SUNDAY NIGHT. LOW PRESSURE TRACKING NE
INTO OUR REGION WILL BRING A SLIGHT CHANCE FOR A MIX OF LIGHT RAIN
AND LIGHT SNOW AS EARLY AS MONDAY BASED ON 12Z GFS GUIDANCE.
HOWEVER THE MUCH BETTER CHANCE FOR MIXED PCPN SHOULD HOLD OFF UNTIL
LATE MONDAY NIGHT AND TUESDAY AS SUGGESTED BY THE SLOWER AND
PREFERRED ECMWF 12Z GUIDANCE SOLUTION (WHICH IS CONSISTENT WITH PCPN
TIMING FROM THE 00Z RUN).
TEMPS WILL UNDERGO A GRADUAL MODERATING TREND DURING THE EARLY TO
MIDDLE PORTION OF NEXT WEEK WITH MAX TEMPS EXPECTED TO REACH THE
UPPER 30S TO LOWER 40S BY TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1204 AM EST FRI FEB 22 2013
FORECAST THINKING HAS NOT CHANGED MUCH FROM THE 00Z SET OF TAFS.
STILL EXPECTING MVFR CEILINGS TO FILL IN THE REMAINDER OF THE
NIGHT WITH SNOW BREAKING OUT AROUND 09Z AT KAZO. THE SNOW WILL
SPREAD NORTHEAST BETWEEN 09Z AND 15Z. THE BAND OF SNOW WILL HAVE
BURSTS THAT WILL BE HEAVY AT TIMES...DROPPING VSBY/S POSSIBLY TO
AROUND A HALF MILE AT TIMES. THE SNOW WILL EXIT THE TAF SITES
BETWEEN 14Z-15Z WITH FREEZING DRIZZLE PERSISTING INTO THE
AFTERNOON HOURS. THE IFR CEILINGS THAT WILL ACCOMPANY THE SNOW
WILL LINGER INTO THE EVENING HOURS.
&&
.MARINE...
ISSUED AT 359 PM EST THU FEB 21 2013
AFTER FURTHER CONSIDERATION...ISSUED A NEW SMALL CRAFT ADVISORY BEGINNING
TONIGHT TO ACCOUNT FOR STRENGTHENING EAST WINDS TOWARDS MORNING. ALTHOUGH
WAVE GROWTH WILL BE LIMITED SOMEWHAT BY POOR FETCH...SUSTAINED WINDS
WELL IN EXCESS OF 20 KTS TOWARDS SUNRISE WILL GREATLY INCREASE THE
HAZARD.
&&
.HYDROLOGY...
ISSUED AT 330 PM EST THU FEB 21 2013
WITH ADDITIONAL QPF EXPECTED TO STAY WELL UNDER HALF AN INCH...THERE
ARE NO CONCERNS AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST FRIDAY FOR MIZ050-
056>059-064>067-071>074.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST SATURDAY FOR LMZ844>849.
&&
$$
UPDATE...93
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS BUFFALO NY
332 AM EST FRI FEB 22 2013
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE AREA FROM THE OHIO VALLEY THROUGH
TONIGHT...BRINGING THE CHANCE FOR A LIGHT WINTRY MIX OF
PRECIPITATION THIS AFTERNOON THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER LOW CROSSING THE NEBRASKA/IOWA BORDER EARLY THIS MORNING
WILL MOVE NORTHEAST INTO SOUTHERN WISCONSIN BY THIS EVENING...
REACHING THE UPPER PENINSULA OF MICHIGAN BY LATE TONIGHT. THE
ACCOMPANYING LOW LEVEL THETA-E RIDGE ON THE NOSE OF A 50 KNOT PLUS
SOUTHERLY LOW LEVEL JET CURRENTLY FOCUSING A BAND OF PRECIPITATION
ACROSS SOUTHERN LOWER MICHIGAN INTO CENTRAL OHIO. LATEST HRRR RUNS
SEEMS TO HAVE A DECENT HANDLE ON SPEED OF APPROACHING
PRECIPITATION WHICH SHOWS LITTLE DEVIATION FROM PREVIOUS FORECAST
TIMING...PLACING THE LEADING EDGE OF WEAKENING PRECIPITATION
SHIELD INTO SOUTHWEST NEW YORK AROUND NOON TIME. EVAPORATIONAL
COOLING AFFECTS WILL MORE THAN LIKELY RESULT IN PRECIPITATION TYPE
AS PREDOMINANTLY SNOW...ALTHOUGH PORTIONS OF THE SOUTHERN TIER
COULD POTENTIAL EXPERIENCE SUFFICIENT LOW LEVEL WARM AIR ADVECTION
FOR PRECIPITATION TO CHANGE TO SLEET/FREEZING RAIN BRIEFLY BEFORE
MID LEVEL DRY SLOT MOVES IN. THE OVERALL SYSTEM TAKING ON A SPLIT
PATTERN AS THE MAIN UPPER LEVEL SUPPORT LIFTS NORTH AND WEST OF
THE AREA INTO THE UPPER LAKES...WHILE THE PRIMARY PLUME OF DEEP
MOISTURE SLIDES OFF TO THE SOUTH AND EAST INTO THE MID ATLANTIC
STATES. THIS WILL LIKELY GREATLY LIMIT THE PRECIPITATION POTENTIAL
ACROSS WESTERN NEW YORK WITH ONLY LIGHT AMOUNTS EXPECTED...WITH
EVEN THE POTENTIAL FOR SOME AREAS NOT RECEIVING ANY MEASURABLE
PRECIPITATION AT ALL. AFTER THE DRY SLOT MOVES THROUGH THE AREA
TONIGHT...LINGERING LOW LEVEL WARM AIR ADVECTION COMBINED WITH
SATURATED LOW LEVELS MAY RESULT IN A PERIOD OF FREEZING DRIZZLE
ACROSS THE AREA BEFORE LOW LEVELS DRY OUT A BIT AND THE WARM AIR
ADVECTION DIMINISHES. EVEN AT THIS STAGE OF THE FORECAST TOO MANY
UNCERTAINTIES TO ISSUE HEADLINES...ALTHOUGH HEADLINES MAY
EVENTUALLY BE NEEDED FOR PORTIONS OF THE AREA AS THE EVENT UNFOLDS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
ON SATURDAY...THE LOW OVER THE GREAT LAKES WILL MOVE INTO SOUTHERN
ONTARIO AND WEAKEN AS THE COASTAL LOW MOVING NORTHEAST NEAR THE
CAROLINA COAST GATHERS STRENGTH OFFSHORE. THIS WILL MAINTAIN A SPLIT
IN THE PRECIP FIELD WITH MOST PRECIP NORTH AND SOUTH OF THE FORECAST
AREA...BUT INCREASING POPS OVER CENTRAL AND NORTHERN NY SATURDAY
AFTERNOON AND EVENING ASSOCIATED WITH GREAT LAKES/ONTARIO LOW`S COLD
FRONT INTERCEPTING WRAP AROUND MOISTURE FROM THE GATHERING STORM
ALONG THE COAST.
THE PRECIP TYPE WILL BE A WINTRY MIX IN THE MORNING WITH A CHANCE OF
SNOW...FREEZING RAIN AND SLEET FOR THE SOUTHERN TIER AND EASTERN
LAKE ONTARIO COUNTIES...AND PLAIN RAIN FOR THE WARMER LOWER
ELEVATIONS ALONG THE LAKE PLAINS SOUTH OF LAKE ONTARIO AND CLOSER TO
LAKE ERIE. THE PRECIP SHOULD TRANSITION TO ALL RAIN BY THE AFTERNOON
AS TEMPS CLIMB TO THE MID 30S TO LOWER 40S.
MID LEVEL MOISTURE BECOMES SCARCE FROM WEST TO EAST THROUGH THE LATE
AFTERNOON AND EVENING...AS A DRY SLOT BETWEEN THE NOW FADING LOW
OVER SOUTHERN ONTARIO AND THE COASTAL LOW SOUTH OF COASTAL NEW
ENGLAND. THERE WILL BE A LINGERING CHANCE OF LIGHT SNOW ALONG THE
CHAUTAUQUA RIDGE WITH WESTERLY WINDS PROVIDING SUFFICIENT LIFT OF
THE MARGINAL LOW LEVEL MOISTURE TO CREATE LIGHT PRECIP. CENTRAL AND
NORTHERN NY WILL HAVE CHANCE POPS FOR LIGHT SNOW AS WELL...AND THE
ENTIRE FORECAST AREA WILL EXPERIENCE LOW TEMPS IN THE LOWER TO MID
20S DURING SATURDAY NIGHT.
EXPECT CLEARING AND SUNNIER SKIES ON SUNDAY FOR WESTERN NY AND
FINGER LAKES...WITH STUBBORN CLOUDS CLINGING TO THE CHAUTAUQUA
RIDGE...AND CONTINUED CLOUDINESS AND SCATTERED LIGHT SNOW ACROSS THE
NORTH COUNTRY FROM THE NOW DEPARTING COASTAL LOW. AN INFLUX OF
COLDER AIR FROM THE WEST WILL HOLD HIGH TEMPS ON SUNDAY TO THE LOWER
TO MIDDLE 30S.
UPPER RIDGING AND SURFACE HIGH PRESSURE WILL BRING NEARLY CLEAR
SKIES FOR SUNDAY NIGHT THROUGH MUCH OF MONDAY...WITH LOWS SUNDAY
NIGHT IN THE LOWER TO MIDDLE 20S AND HIGHS ON MONDAY IN THE UPPER
30S TO LOWER 40S.
ANOTHER MID CONTINENTAL CUT OFF LOW AND ATTENDANT SURFACE LOW WILL
RECURVE TO THE NORTHEAST ACROSS THE MID MISSISSIPPI
VALLEY...SHUNTING A WARM FRONT NORTHWARD TO THE OHIO VALLEY. THIS
WILL BRING MORE CLOUDINESS TO THE REGION MONDAY NIGHT AND A CHANCE
OF LIGHT SNOW OR A RAIN/SNOW MIX TO THE WESTERN SOUTHERN TIER. 00Z
GFS IS MUCH FASTER THAN 00Z ECMWF WITH THIS PRECIP MONDAY NIGHT...
THE PREFERRED MODEL IS THE ECMWF SO WILL GO CLOSER TO EC AND SLOW
SPREAD OF PRECIP TO MAINLY THE AREA WEST OF THE GENESEE RIVER.
LOW MONDAY NIGHT WILL BE LIMITED TO THE UPPER 20S TO LOWER 30S FOR
MOST OF THE REGION WITH THE INFLUX OF CLOUD COVER...THE LOWER TO MID
20S EAST OF LAKE ONTARIO WHERE CLOUDS WILL ARRIVE LATER.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL START OFF WITH FAIR WEATHER ON MONDAY AS
THE AXIS OF STRONG SURFACE RIDGING DRIFTS EAST ACROSS NEW YORK
STATE. WITH 850 MB TEMPS LOOKING TO BE IN THE -7C TO -8C RANGE...
TEMPS SHOULD BE SEASONABLE TO SLIGHTLY ABOVE NORMAL...WITH HIGHS IN
THE 35-40 RANGE.
AFTER THAT...CONDITIONS WILL GO DOWNHILL FOR THE REST OF THE PERIOD
AS A DEEP CUTOFF LOW FORMS OVER THE CENTRAL MISSISSIPPI VALLEY...
THEN MIGRATES INTO THE GREAT LAKES REGION. MEANWHILE AT THE
SURFACE...A CORRESPONDING SURFACE LOW OVER ILLINOIS WILL SLOWLY LIFT
NORTHEAST INTO THE CENTRAL GREAT LAKES...WHILE A SECONDARY WAVE OF
LOW PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST.
WHILE THE MEDIUM RANGE MODELS AGREE ON THIS GENERAL SCENARIO...THEY
DISAGREE CONSIDERABLY ON THE TIMING OF ALL OF THIS...WITH THE 12Z
GFS MUCH FASTER WITH THE NORTHEASTWARD TRANSLATION OF THE CUTOFF AND
ASSOCIATED SURFACE LOW COMPARED TO THE MUCH SLOWER 12Z ECMWF...WITH
THE 12Z GEM GLOBAL LYING IN BETWEEN THESE TWO SOLUTIONS. THIS SORT
OF TIMING DISAGREEMENT IS TYPICAL FOR THE MODELS WHEN ATTEMPTING TO
HANDLE THE EVOLUTION OF A LARGE CUTOFF LOW THIS FAR OUT...WHICH IN
GENERAL TEND TO MOVE MORE SLOWLY THAN THE GUIDANCE SUGGESTS. WITH
THIS IN MIND...WILL TEND TO LEAN A BIT MORE TOWARD THE SLOWER ECMWF
FOR THE LATTER PORTIONS OF THE EXTENDED...THOUGH AT THE SAME TIME
WILL ALSO NOT ENTIRELY DISREGARD THE OTHER SOLUTIONS EITHER.
REGARDLESS OF THIS UNCERTAINTY IN TIMING...ALL OF THIS SHOULD
ULTIMATELY BRING INCREASED CHANCES FOR PRECIPITATION TO OUR AREA FOR
THE TUESDAY THROUGH THURSDAY PERIOD...WITH AT LEAST SOME POTENTIAL
FOR SIGNIFICANT PRECIP AMOUNTS /I.E. THOSE OF ONE INCH OR HIGHER/ AT
SOME POINT GIVEN WHAT SHOULD BE AN INFLUX OF PLENTIFUL ATLANTIC
MOISTURE ON THE EAST SIDE OF THIS SYSTEM. ACCORDINGLY...WILL
INDICATE A FAIRLY PROLONGED PERIOD OF HIGHER CHANCE TO EVEN SOME LOW
LIKELY POPS BEGINNING ON TUESDAY. IN TERMS OF PTYPE...TEMPS LOOK TO
BE RATHER MARGINAL THROUGHOUT THE MIDDLE OF NEXT WEEK...SO FOR NOW
WILL JUST INDICATE A GENERAL RAIN/SNOW MIX...WITH THE EXACT PTYPES
AT ANY GIVEN TIME DEPENDENT UPON THE POINT IN THE DIURNAL CYCLE.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVING ACROSS THE REGION TONIGHT WILL KEEP CONDITIONS
DRY THROUGH THE OVERNIGHT PERIOD. LIGHT NORTHERLY FLOW OFF OF LAKE
ONTARIO WILL LIKELY KEEP MVFR CIGS...WITH LOCALIZED IFR CONDITIONS
ACROSS HIGHER TERRAIN IN THE SOUTHERN TIER AND NORTH
COUNTRY...LOCKED IN ACROSS THE AREA AT LEAST THROUGH 08-10Z UNTIL
INCREASING EAST-SOUTHEAST FLOW HELPS CLEAR OUT LOWER CLOUD
COVER...ALLOWING CONDITIONS TO IMPROVE TO VFR.
HIGH CLOUDS STREAMING NORTH AHEAD OF AN APPROACHING WARM FRONT WILL
MOVE INTO THE REGION LATER TONIGHT...HOWEVER VFR CONDITIONS SHOULD
PREVAIL AT LEAST THROUGH THE MORNING HOURS. BREEZY SOUTHEASTERLY
FLOW WILL DEVELOP AT KJHW DURING THE AFTERNOON AS STRONGER WINDS
ALOFT MIX DOWN TO THE SURFACE...BUT OTHERWISE OTHER TERMINALS SHOULD
STAY SOUTHEASTERLY AROUND 10KTS.
AS THE WARM FRONT MOVES INTO THE AREA LATER TOMORROW AFTERNOON AND
INTO THE EVENING HOURS THERE WILL LIKELY BE AT LEAST A BRIEF PERIOD
OF -SN THAT WILL CHANGE OVER TO A WINTRY MIX AS WARM AIR ALOFT MAKES
ITS WAY INTO THE AREA. HOWEVER MODEL SOUNDINGS INDICATE THE PRESENCE
OF DRY AIR IN THE MID-LEVELS THAT MAY BE CONDUCIVE TO PRECIP MAINLY
FALLING AS DZ/FZDZ AFTER 21Z ACROSS WESTERN NEW YORK AS TEMPERATURES
WILL HOVER RIGHT AROUND OR JUST ABOVE FREEZING...HOWEVER CONFIDENCE IS
MEDIUM TO LOW REGARDING THIS SCENARIO AT THIS POINT IN TIME AND FOR
NOW WILL LEAVE IT OUT OF TAFS WITH THE EXCEPTION OF KJHW WHERE
CONFIDENCE IS HIGHER.
OUTLOOK...
FRIDAY NIGHT AND SATURDAY...MVFR WITH A CHANCE OF MIXED
PCPN...TRANSITIONING TO A CHANCE OF RAIN.
SUNDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
MONDAY...VFR.
TUESDAY...MVFR WITH A CHANCE OF RAIN/SNOW.
WEDNESDAY...MVFR WITH A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
EASTERLY WINDS WILL PICK UP TODAY AHEAD OF AN APPROACHING AREA OF
LOW PRESSURE...BRINGING INCREASING WAVE ACTION ABOVE 4 FEET ON THE
WESTERN HALF OF LAKE ONTARIO. ALTHOUGH THE BULK OF THE HIGHER WAVES
ARE EXPECTED OVER THE MIDDLE AND NORTHERN PORTIONS OF THE LAKE...
SMALL CRAFT CONDITIONS WILL LIKELY DEVELOP FOR A PERIOD LATE THIS
MORNING THROUGH THIS EVENING...WEST OF IRONDEQUOIT.
A COLD FRONT WILL THEN PUSH ACROSS THE LAKES ON SATURDAY...HOWEVER
THE PRESSURE GRADIENT ACROSS THE REGION SHOULD REMAIN RELAXED
ENOUGH THAT SMALL CRAFT ADVISORY CONDITIONS ARE NOT ANTICIPATED
THROUGH THE WEEKEND AT THIS TIME.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR LOZ042-043.
&&
$$
SYNOPSIS...TMA
NEAR TERM...TMA
SHORT TERM...WCH
LONG TERM...JJR
AVIATION...WOOD
MARINE...TMA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
131 AM CST FRI FEB 22 2013
.DISCUSSION...MAIN UPDATE EARLY THIS MORNING WAS PRECIPITATION
PLACEMENT AND TEMPERATURES.
NORTH TO SOUTH BAND OF LIGHT SNOW CONTINUES ACROSS
WESTERN/CENTRAL NORTH DAKOTA. WEAK UPPER LEVEL TROUGH FROM THE
MANITOBA ROCKIES SOUTH THROUGH CENTRAL MONTANA MOVING VERY SLOWLY
EAST AND MAY CONTRIBUTE TO ADDITIONAL WEAK FORCING FOR LIGHT SNOW
ACROSS MY WEST NOW THROUGH 15Z. ALSO...A FEW SNOW SHOWERS
ASSOCIATED WITH THE UPPER LOW TO OUR SOUTH HAVE MADE IT INTO FAR
SOUTHERN NORTH DAKOTA AROUND WISHEK. MADE ADJUSTMENTS TO POPS
BASED ON LATEST RADAR RETURNS AND THE RAP GUIDANCE.
ADJUSTED TEMPERATURES BASED ON LATEST OBS AND NEAR TERM MODEL
DATA. SURFACE DEWPOINT TEMPERATURES LOOK TO REMAIN IN THE MID TO
UPPER TEENS WEST SO INCREASED LOWS THERE. LOWERED TEMPERATURES
ACROSS MY NORTHEAST WHERE NEAR ZERO SFC TDS ARE LOCATED/ADVECTING
INTO.
&&
.AVIATION...
MODEL GUIDANCE INDICATES ABUNDANT LOW LEVEL MOISTURE AND
NUMERICAL GUIDANCE INDICATES AT LEAST PATCHY IF NOT WIDESPREAD
FOG OVER TAF SITES TONIGHT. EXCEPT FOR KISN AND KDIK WHERE
VISIBILITIES ARE ALREADY REDUCED IN LIGHT SNOW...WILL BRING IN
AREAS OF LOWER CEILINGS...BUT WILL DELAY THE TIMING FROM WHAT
NUMERICAL GUIDANCE INDICATES. THEN KEEP MAINLY MVFR CEILINGS
THROUGH FRIDAY MORNING...AND BREAKING OUT TO VFR BY FRIDAY
AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
AVIATION...TWH/NH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
108 AM EST FRI FEB 22 2013
.SYNOPSIS...
A WINTRY MIX OF SNOW AND SLEET...SHOULD TRANSITION TO FREEZING
RAIN AS TEMPERATURES REMAIN BELOW FREEZING AT THE SURFACE OVERNIGHT.
TEMPERATURES WILL RISE ABOVE FREEZING AND THE FREEZING RAIN WILL
TRANSITION TO RAIN LATE TONIGHT THROUGH FRIDAY MORNING. A COLD
FRONT WILL THEN PUSH ACROSS THE AREA FRIDAY NIGHT WITH SEASONABLE
TEMPERATURES EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE FORECAST HAS BEEN UPDATED TONIGHT WITH A FEW CHANGES.
FIRST...POPS WERE INCREASED AND SPED UP...AS PRECIPITATION HAS
ALREADY ENTERED ABOUT A THIRD OF THE CWA. TIMING WAS BASED HEAVILY
ON LATEST HRRR RUNS...WITH THE BACK EDGE OF THE PRECIPITATION ALSO
SPED UP A LITTLE BIT TOMORROW MORNING. GIVEN THE CERTAINTY OF
PRECIPITATION...100 PERCENT CHANCES WERE USED EVERYWHERE.
THE MORE COMPLICATED DECISIONS WERE RELATED TO PRECIPITATION TYPE.
IT IS APPARENT FROM THE RECENT OBSERVATIONS THAT THE WARM
ADVECTION ALOFT IS PERHAPS OCCURRING SLIGHTLY SLOWER THAN WAS
EARLIER FORECAST. ON THE OTHER HAND...THIS COULD ALSO BE THE
RESULT OF THE FASTER ONSET OF PRECIPITATION THAN WAS PREVIOUSLY
ANTICIPATED. BECAUSE OF THIS...HYDROMETEORS AT PRECIP ONSET ARE
NOT COMPLETING MELTING...LEADING TO A PLETHORA OF SLEET OBS OVER
THE ILN CWA...AND A POCKET OF MODERATE SNOW NOW MOVING INTO THE
WHITEWATER VALLEY AREA.
FREEZING RAIN IS STILL EXPECTED TO BE THE PRIMARY PRECIPITATION
TYPE OVERNIGHT...BUT THE GRIDS NOW REFLECT A GREATER MIXING IN THE
FIRST FEW HOURS OF THE FORECAST. SNOW/SLEET ACCUMULATIONS OF UP TO
A HALF INCH WERE ADDED INTO THE INDIANA COUNTIES AND WESTERN MIAMI
VALLEY (MAINLY EXPECTED IN THE NEXT FEW HOURS)...WITH THE ORIGINAL
FORECAST OF UP TO AN INCH OF SNOW IN THE FAR NORTH STILL ON TRACK.
THE WINTER WEATHER ADVISORY ISSUED BY THE DAY SHIFT COVERS THIS
MIX OF PRECIPITATION QUITE WELL...SO WHILE UPDATES WERE MADE TO
ADD SOME OF THE NEW DETAIL...THE OVERALL PLAN AND LAYOUT FOR THE
HEADLINE PRODUCT HAS NOT CHANGED.
PREVIOUS DISCUSSION >
FOCUS IS ON POTENTIAL FOR ICE EVENT TONIGHT/FRIDAY MORNING IN THE
OHIO VALLEY. UPPER LEVEL AND SFC LOW OVER CENTRAL PLAINS TO EJECT
NE INTO THE MID MS VLY BY 12Z FRIDAY. FAVORABLE ISENTROPIC LIFT
DEVELOPS AHD OF THIS SYSTEM ACRS ILN/S FA TONIGHT. SOUTHERLY 8H
JET OF 60KTS WEAKENS TO 50-55KTS AS IT MOVES INTO THE OHIO VALLEY
BY MORNING. THIS JET WORKS TO PROVIDE GOOD FORCING AND WAA. THE
BEST LIFT DEVELOPS BETWEEN 06Z AND 12Z. WILL CONTINUE RAMPING POPS
UP TO CATEGORICAL LATE THIS EVENING INTO EARLY FRIDAY. QUESTION
REVOLVES AROUND QPF/THERMAL PROFILES AND ULTIMATELY THE AMOUNT OF
ICING. NAM IS THE MORE ENERGETIC WITH FORCING AND THEREFORE HAS
HIGHER QPF. 12Z RUN SOLNS ARE CLOSER AND THEREFORE HAVE GONE WITH
A BLENDED SOLN. UNDER STRONG WAA...TEMPS ALOFT WARM SUFFICIENTLY
FOR LIQUID WHILE SFC TEMPS REMAIN BELOW FREEZING WITH A LOW LEVEL
EASTERLY FLOW.
EXPECT NON-DIURNAL TEMPERATURES WITH READINGS RISING ABOVE
FREEZING ACRS THE FAR SOUTH TOWARD SUNRISE. BASED ON A PROLONGED
PERIOD OF BELOW FREEZING TEMPERATURES EXPECT 1 TO 2 TENTHS OF AN
INCH OF ICE ACCUMULATION WITH THE HIGHEST AMOUNTS ACRS EAST
CENTRAL INDIANA/WHITEWATER VALLEY AND THE MIAMI VALLEY. WILL
CONTINUE WINTER WEATHER ADVISORIES ACRS THE ENTIRE FA FOR THIS
ICE IMPACT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
UPPER LEVEL/SFC LOW PRESSURE TO MIGRATE SLOWLY NE FROM THE UPR MS
VLY INTO THE WESTERN GREAT LAKES FRIDAY. NUMERICAL MODEL SOLNS
CONSISTENT WITH DEEP MSTR AND FORCING ASSOCIATED WITH STRONG LLJ
SHIFTING NE OF ILNS FA FRIDAY MORNING. AT THE SAME TIME UNDER THE
INFLUENCE OF WAA...SFC TEMPERATURES WARM ABOVE FREEZING BY MIDDAY
FROM SOUTH TO NORTH. WILL DIMINISH POPS A LTL QUICKER TO REFLECT
THIS FASTER TIMING AS THE FAVORABLE FORCING EXITS THE REGION.
EXPECT HIGH TEMPS TO BE A LTL ABOVE NORMAL...RANGING FROM THE
UPPER 30S NW TO THE LOWER 50S FAR SOUTH.
SFC LOW TO MIGRATE THRU THE GREAT LAKES WITH A TRAILING COLD
FRONT FROM THE LOW CROSSING THE FORECAST AREA FRIDAY NIGHT. THIS
WILL BRING A RETURN TO COLDER...MORE SEASONABLE TEMPERATURES. DUE
TO A LACK OF SIGNIFICANT FORCING AND MSTR HAVE ONLY CONTINUED
SLIGHT CHC POPS ACRS THE FAR NORTH. FRIDAY NIGHTS LOWS WILL RANGE
FROM THE UPPER 20S NORTHWEST TO THE MID 30S SE.
UPPER LOW TO CONTINUE TO WORK ACRS THE GREAT LAKES SAT/SAT NIGHT.
BETTER MSTR LOOKS TO STAY NORTH OF ILNS/ FA AND IT APPEARS AT
THIS TIME THAT THE FLOW TRAJECTORIES AROUND THE LOW WILL NOT BE
FAVORABLE TO BRING ANY SNOW SHOWERS INTO OUR AREA. THEREFORE HAVE
MAINTAINED A DRY FCST. EXPECT SATURDAYS HIGHS TO BE A LTL BELOW
NORMAL...RANGING FROM THE MID 30S NW TO THE MID 40S SE. LOWS SAT
NIGHT ARE EXPECTED TO RANGE FROM THE LOWER 20S NW TO THE MID 20S SE.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MODELS SHOW HIGH PRESSURE BUILDING IN ON SUNDAY SO KEPT THE FORECAST
DRY. NEXT SYSTEM DUE TO ARRIVE LATE MONDAY IS SLOWER ON LATEST MODEL
RUNS...SO HELD BACK ONSET AND ENDING OF SHOWERS BY A FEW HOURS.
COLDER TEMPERATURES EARLY MONDAY NIGHT MAY ALLOW SNOW TO MIX IN FOR
A TIME. MAIN BAND OF SHOWERS SHOULD EXIT EAST TUESDAY AFTERNOON.
A COLDER PATTERN WITH A LINGERING LOW OVER THE GREAT LAKES WILL SET
UP TUESDAY NIGHT THROUGH THURSDAY. THIS WILL RESULT IN A FEW ROUNDS
OF SNOW SHOWERS...WITH RAIN POSSIBLY MIXING IN AT SOUTHERN
LOCATIONS.
COOL READINGS AROUND 40 ON SUNDAY WILL BE BOOSTED CLOSE TO 50 ON
MONDAY DUE TO WARM ADVECTION AHEAD OF THE LOW. BELOW NORMAL HIGHS IN
THE 30S ARE EXPECTED BY THURSDAY IN A NORTHWESTERLY LOW LEVEL FLOW.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
FREEZING RAIN WILL START OUT THE TAF PERIOD AT KCVG AND KLUK.
FURTHER TO THE NE AT KILN SOME ICE PELLETS MAY STILL MIX IN WITH
THE FREEZING RAIN AT THE TAF ONSET HOWEVER AS THE OVERNIGHT HOURS
PROGRESS THE PRECIPITATION TYPE WILL GENERALLY BE FREEZING RAIN.
AT KDAY A MIXTURE OF SNOW AND ICE PELLETS WILL START OUT THE TAF
PERIOD AND THEN ALSO GRADUALLY TRANSITION OVER TO FREEZING RAIN.
KCMH AND KLCK TAF SITES WILL START OUT DRY HOWEVER SNOW AND ICE
PELLETS WILL QUICKLY MOVE INTO THOSE LOCATIONS. KCMH AND KLCK WILL
ALSO GRADUALLY TRANSITION OVER TO FREEZING RAIN DURING THE
OVERNIGHT HOURS.
TEMPERATURES WILL GRADUALLY WARM ACROSS THE TAF SITES OVERNIGHT
AND INTO FRIDAY WITH TAF SITES SURFACE TEMPERATURES GOING ABOVE
FREEZING BETWEEN AROUND 10Z AT KCVG AND KLUK TO 14Z AT KCMH AND
KLCK. RAIN WILL TAPER OFF DURING THE MORNING HOURS ACROSS THE TAF
SITES LEAVING MAINLY DRY CONDITIONS BY THE LATE MORNING HOURS.
WINDS WILL GUST OFF AND ON FOR A FEW HOURS AT THE BEGINNING TO THE
TAF PERIOD. AFTER THIS TIME EXPECT WIND GUST ACTIVITY TO DECREASE
HOWEVER WINDS WILL STAY UP ACROSS THE TAF SITES. SOME ADDITIONAL
WIND GUSTS WILL BE POSSIBLE DURING THE AFTERNOON HOURS ON FRIDAY
AT KCVG. WINDS WILL BE OUT OF THE EAST TO START AND GRADUALLY
TRANSITION TO SOUTHERLY AND FINALLY TO WEST SOUTHWEST AS THE TAF
PERIOD PROGRESSES.
VFR CIGS WILL START OUT THE TAF PERIOD HOWEVER EXPECT CIGS TO
GRADUALLY BECOME MVFR TO IFR ACROSS THE TAF SITES. MOST OF THE TAF
SITES WILL STAY MVFR TO IFR THEN THROUGH THE TAF PERIOD HOWEVER
KCVG AND KLUK MAY BECOME VFR FOR A FEW HOURS DURING THE AFTERNOON
ON FRIDAY.
OUTLOOK...MVFR TO IFR CEILINGS MAY CONTINUE INTO FRIDAY
NIGHT...AND POSSIBLY THROUGH SATURDAY FOR THE NORTHERN TAF SITES.
MVFR CONDITIONS ARE POSSIBLE AGAIN ON MONDAY AND TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-080-082.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ077>079-081-088.
KY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR INZ050-058-
059-066.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
INZ073>075-080.
&&
$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS MEDFORD OR
830 PM PST THU FEB 21 2013
.DISCUSSION...WE HAVE LOWERED CHANCES FOR PRECIPITATION ACROSS THE
NORTHERN CALIFORNIA AND EXTREME SOUTHWESTERN OREGON FOR TONIGHT
GIVEN THE LATEST OBSERVATIONS AND RAP GUIDANCE FOR TONIGHT. THE
WARM FRONTAL PRECIPITATION WILL WANE OVERNIGHT...FOCUSING
PRIMARILY OVER THE CASCADES. A BRIEF BREAK IN PRECIPITATION WILL
OCCUR FRIDAY MORNING AHEAD OF THE STRONG COLD FRONT.
TODAY`S EFFORTS HAVE BEEN FOCUSED ON THE STRONG STORM DUE TO
ARRIVE FRIDAY EVENING...LETTING US KNOW THAT WINTER IS STILL ALIVE
AND WELL IN SOUTHERN OREGON. A WINTER STORM WARNING AND A COUPLE
WINTER WEATHER ADVISORIES HAVE BEEN ISSUED AT WSWMFR TO HIGHLIGHT
THE SNOWFALL EXPECTED. ADDITIONALLY...HIGH SURF AND STRONG WINDS
WILL IMPACT THE COAST...AND A SPECIAL WEATHER STATEMENT AT SPSMFR
BRINGS ATTENTION TO THIS. ESRL REFORECAST ANALOGS CONFIRM OUR
THOUGHTS THAT THIS WILL BE A SIGNIFICANT WINTER STORM...SUGGESTING
THIS WILL RANK IN THE TOP THIRD IN TERMS OF 24-HR PRECIPITATION FOR
MOST OF SOUTHERN OREGON ALONG AND WEST OF THE CASCADES. STRONG WEST
WINDS WILL ACCOMPANY THIS STORM...THUS FOCUSING THE HEAVIEST
PRECIPITATION OVER WEST AND NORTHWEST FACING SLOPES OF THE CASCADES.
TRAVEL IN AND AROUND THE CASCADES WILL BE SEVERELY IMPACTED FROM
FRIDAY NIGHT INTO SATURDAY.
FOR LOWER ELEVATIONS OF THE WEST SIDE...AROUND 2000 FEET OR A BIT
LOWER...MODELS STILL POINT TOWARD THE POSSIBILITY OF SNOWFALL LATE
FRIDAY NIGHT OR SATURDAY MORNING. 850MB TEMPERATURES BOTTOM OUT NEAR
-6C...AND A SECONDARY PULSE OF UPWARD MOTION AND ASSOCIATED SHOWERS
IN THE NAM ARE GOOD INDICATORS OF THIS POSSIBILITY.
PLEASE SEE THE DISCUSSION BELOW FOR MORE DETAILS REGARDING THE
EVOLUTION OF THE APPROACHING STORM...AND THE EXPECTED CONTINUATION
OF ACTIVE WEATHER THROUGH EARLY NEXT WEEK.
&&
.AVIATION...FROM THE CASCADES WEST...AREAS OF MVFR CIGS WITH HIGHER TERRAIN
OCCASIONALLY OBSCURED WILL PERSIST INTO FRIDAY MORNING. CONDITIONS
WILL BRIEFLY IMPROVE TO LOCAL MVFR CIGS LATE FRIDAY MORNING...THEN
WIDESPREAD MVFR CIGS WITH AREAS OF MVFR VSBYS WITH HIGHER TERRAIN
OBSCURED WILL SPREAD INLAND FROM THE COAST FRIDAY AFTERNOON.
STRONG SOUTH WINDS WILL AFFECT THE COAST FRIDAY. MODERATE TO
HEAVY RAIN AND STRONG WINDS WILL ACCOMPANY THE LOWER CIG/VSBYS.
FREEZING LEVELS WILL DROP SHARPLY FRIDAY AFTERNOON AS THE COLD
FRONT MOVES INLAND...AND MODERATE TO HEAVY SNOW WILL AFFECT THE
HIGHER TERRAIN.
EAST OF THE CASCADES...MOSTLY VFR CONDITIONS WILL PREVAIL INTO
FRIDAY AFTERNOON. GUSTY WINDS WILL DEVELOP FRIDAY AFTERNOON...THEN
AREAS OF MVFR CIGS/VSBYS IN RAIN AND SNOW WILL DEVELOP LATE FRIDAY
AFTERNOON NEAR THE CASCADES.
&&
.PREV DISCUSSION... /ISSUED 414 PM PST THU FEB 21 2013/
DISCUSSION...A STRONG FRONT IS EXPECTED TO BRING SIGNIFICANT
SNOWFALL TO THE NORTHERN CASCADES LATE FRIDAY INTO EARLY SATURDAY.
WEST SIDE VALLEYS COULD ALSO SEE SEVERAL INCHES OF SNOW DOWN TO
2000 FEET BY SATURDAY MORNING.
BUT BEFORE WE GET TO THAT SYSTEM, WE ARE WATCHING A WEAKER FRONT
MOVE ACROSS THE AREA THIS AFTERNOON. THIS SYSTEM IS BEHAVING AS THE
MODELS INDICATED AND MANY OF THE WEST SIDE OBSERVATION SITES HAVE
REPORTED LIGHT RAIN ALREADY. THIS SYSTEM WILL MAKE ITS WAY INLAND TO
THE CASCADES BEFORE FALLING APART OVER THAT HIGHER TERRAIN LATER
TONIGHT.
THEN THE ATTENTION SHIFTS TO FRIDAY AFTERNOON. THE COLD FRONT IS
STILL ON TRACK WITH VERY FEW CHANGES FROM THE EARLIER MODEL RUNS.
THE BRUNT OF THE ENERGY WITH A 100+ KT JET IS STILL FOCUSED OVER
NORTHERN OREGON. BUT THERE WILL STILL BE PLENTY OF ACTIVITY OVER
THE SOUTHERN CASCADES. RIGHT NOW, IT LOOKS AS IF THE HEAVIEST SNOW
ACCUMULATION WILL ALIGN FROM THE LAKE OF THE WOODS AREA NORTHWARD.
THE FRONT ITSELF WILL BE RESPONSIBLE FOR PRODUCING THE MAJORITY OF
THE PRECIPITATION AND THE HEAVIEST ACCUMULATION WILL LIKELY BE
LATE FRIDAY AFTERNOON INTO FRIDAY EVENING. THEN THE MODELS SHOW A
SLIGHT BREAK AROUND MIDNIGHT BEFORE MORE SHOWERS FILL IN OVER THE
SAME AREA SATURDAY MORNING. THERE IS A FAIR AMOUNT OF UNCERTAINTY
WITH ACCUMULATIONS IN THESE SHOWERS THROUGH THE DAY SATURDAY. BUT
AMOUNTS AND INTENSITY SHOULD DECREASE SIGNIFICANTLY AFTER
DAYBREAK, SO HAVE OPTED TO END THE WARNING AT 4AM.
WE ALSO ELECTED TO HOIST A WINTER WEATHER ADVISORY WSWMFR FOR
AREAS ABOVE 2000 FEET WEST OF THE CASCADES. ACCUMULATIONS WILL
DEFINITELY BE HEAVIEST ON WEST AND NORTHWEST FACING SLOPES WITH
40KTS AT 850MB LEADING TO UPSLOPE ENHANCEMENT. THE TIMING OF THE
COLD AIR LOOKS TO MAKE IT IN BEHIND THE FRONT WHILE ENOUGH
MOISTURE LINGERS TO PRODUCE 1 TO 3 INCHES OF ACCUMULATION. WITH
THE MAJORITY OF THE PRECIPITATION FALLING DURING THE OVERNIGHT
HOURS THIS WILL MAKE FOR THE BEST CHANCE FOR ACCUMULATION ON
ROADWAYS AS TEMPERATURES BOTTOM OUT. MODELS DID SHOW A SLIGHT
TENDENCY TO SHUNTING THE COLD AIR TO THE NORTH AND EAST OF OUR
AREA, SO WE WILL BE KEEPING AN EYE ON THIS. THE NEXT COMPONENT OF
THIS SYSTEM WILL BE GUSTY SW WINDS. WINDS SHOULD MAKE ADVISORY
CRITERIA OVER THE HIGHER TERRAIN EAST OF THE CASCADES. AND EVEN
FOR THE WEST SIDE, WINDS COULD CAUSE ENOUGH BLOWING SNOW TO MAKE
TRAVEL THAT MUCH MORE CHALLENGING.
FOR THE REST OF THE WEEKEND...SHOWERS WILL CONTINUE IN THE WAKE OF
THE STRONG FRONT ON SATURDAY. ACCUMULATIONS SHOULD BE LIGHT DURING
THE DAY AND THEN TAPER OFF COMPLETELY BEFORE SUNDAY MORNING. THE
BIGGEST STORY FOR SATURDAY WILL BE THE HIGH SURF AT THE COAST. SEE
THE SPSMFR FOR MORE DETAILS ON THIS. SUNDAY WILL BRING A
SHORTWAVE RIDGE TO DRY OUT THE AREA AND ALLOW SNOW LEVELS TO
REBOUND TO NEAR 4000 FT.
..EXTENDED TERM...MONDAY THOUGH THURSDAY NIGHT...
THE LONG TERM MODEL SOLUTIONS ARE SIMILAR IN TIMING...BUT HAVE
CONSIDERABLE DIFFERENCES IN THE OVERALL STRENGTH OF THE VARIOUS
WEATHER MAKING FEATURES THAT ARE EXPECTED TO PASS THROUGH THE AREA.
THIS OF COURSE RESULTS IN REDUCED CONFIDENCE FOR MOST OF THE
FORECAST DETAILS. HOWEVER...THERE REMAINS DECENT CONFIDENCE IN THE
OVERALL PATTERN.
THE FIRST SYSTEM TO ENTER THE REGION WILL RIDE THE NORTHWEST FLOW
ALOFT INTO THE AREA MONDAY. THE TROUGH...MORE PRONOUNCED AND SHARPER
IN THE ECMWF SOLUTION THAN IN THE GFS...SHOULD RESULT IN INCREASED
CHANCES OF PRECIPITATION...ESPECIALLY NORTH OF THE OREGON/CALIFORNIA
STATE LINE. SNOW LEVELS LOOK TO STAY ABOVE 3000 FEET DURING THE
EVENT...AND PRECIPITATION AMOUNTS APPEAR TO BE MUCH LIGHTER THAN IN
THE SHORT TERM SYSTEMS. HOWEVER...DESPITE THE TROUGH EXITING THE
AREA MONDAY NIGHT AND WEAK RIDGING BUILDING INTO THE AREA...THERE
REMAINS THE CHANCE OF LINGERING SHOWERS THROUGH TUESDAY.
THE NEXT SYSTEM...DUE TUESDAY NIGHT OR WEDNESDAY...APPEARS EVEN
WEAKER THAN THE PREVIOUS...AND IS FORECAST TO PASS FURTHER TO THE
NORTH. WITH SNOW LEVELS OF 5000 FEET OR ABOVE...MOST PRECIPITATION
IN THE AREA WILL BE LIGHT RAIN. SHOWERS AND ONSHORE FLOW ARE
EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE TERM.
WITH HIGH PRESSURE GAINING MORE AND MORE INFLUENCE AS THE WEEK
PROGRESSES...TEMPERATURES WILL EXPERIENCE A GRADUAL WARMING TREND
THROUGH THE TERM...FROM SLIGHTLY BELOW NORMAL AT THE BEGINNING OF
THE WEEK TO NEAR NORMAL OR SLIGHTLY ABOVE BY THURSDAY.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 1 PM FRIDAY TO 4 AM PST SATURDAY FOR
ORZ030-031.
WINTER WEATHER ADVISORY FROM 10 PM FRIDAY TO 10 AM PST SATURDAY
FOR ORZ023-024-026.
WINTER STORM WARNING FROM 4 PM FRIDAY TO 4 AM PST SATURDAY FOR
ORZ027-028.
WINTER WEATHER ADVISORY FROM 8 PM FRIDAY TO 10 AM PST SATURDAY
FOR ORZ025.
CA...WIND ADVISORY FROM 1 PM FRIDAY TO 4 AM PST SATURDAY FOR CAZ085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM TO 4 PM PST FRIDAY FOR
PZZ356-376.
HAZARDOUS SEAS WARNING FROM 7 AM FRIDAY TO 10 PM PST SATURDAY
FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 AM PST FRIDAY
FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM TO 10 AM PST FRIDAY FOR
PZZ350-370.
GALE WARNING FROM 10 AM TO 4 PM PST FRIDAY FOR PZZ350-370.
$$
NSK/BPN/JRS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1201 AM CST FRI FEB 22 2013
.UPDATE...FOR 06Z TAFS...
&&
.AVIATION...
ONLY A FEW WEAK SHOWERS STILL SHOWING UP ON THE RADAR. BNA AND CKV
SHOULD BE DRY FOR THE REMAINDER OF THE TAF PERIOD WITH A FEW LIGHT SHOWERS
POSSIBLE AT CSV THROUGH 07Z. LIGHT FOG MAY REDUCE VISIBILITIES TO
AROUND 4 MILES AT SOME SITES IN THE EARLY MORNING HOURS. CIGS ARE
CONTINUING TO DROP INTO IFR RANGE AS THE PRECIP MOVES EAST...BUT
CONDITIONS ARE EXPECTED TO IMPROVE CLOSER TO DAWN ON FRIDAY WITH
INCREASING CIGS AND VISIBILITY. HOWEVER OVERCAST HIGH CLOUDS ARE
EXPECTED TO REMAIN IN PLACE THROUGHOUT THE DAY.
&&
.PREV DISCUSSION... /ISSUED 816 PM CST THU FEB 21 2013/
UPDATE...
LATEST RADAR IMAGERY SHOWS LARGE AREA OF LIGHT TO MODERATE RAIN
ACROSS THE MID STATE...BUT BACK EDGE CAN BE SEEN NOW EAST OF THE
MISSISSIPPI RIVER. HRRR TIMING INDICATES MOST OF THE RAIN WILL
LIKELY END WEST OF I-65 AROUND MIDNIGHT...WITH SOME RAIN
CONTINUING THROUGH THE NIGHT TO THE EAST. HAVE ADJUSTED POPS
DOWNWARD IN THE 06-12Z TIMEFRAME WITH CHANCE POPS IN THE WEST TO
CATEGORICAL IN THE EAST. WILL ALSO ADD MENTION OF ISOLATED THUNDER
TO THE SOUTHWEST HALF OF THE CWA THIS EVENING AS A FEW LIGHTNING
STRIKES HAVE BEEN NOTED FROM TIME TO TIME.
TEMPERATURES CURRENTLY RANGE FROM THE MID 30S ALONG THE KY BORDER
TO THE MID 40S ALONG THE AL BORDER. THESE VALUES WILL BE THE LOWS
FOR TONIGHT AS WAA CONTINUES TO INCREASE THROUGH THE NIGHT AND
TEMPERATURES WARM WELL INTO THE 40S AREAWIDE BY SUNRISE AND
POSSIBLY 50S IN OUR SOUTHERN ZONES. MADE MINOR ADJUSTMENTS TO
TEMPS BUT NO OTHER CHANGES ATTM.
PREV DISCUSSION... /ISSUED 657 PM CST THU FEB 21 2013/
UPDATE...FOR 00Z TAFS...
AVIATION...
LIGHT TO MODERATE RAIN SHOWERS CONTINUE TO MOVE ACROSS THE MID
STATE THIS EVENING..WITH OBS INDICATING A FEW LIGHTNING STRIKES IN
THE STRONGER CELLS. CEILINGS ARE EXPECTED TO LOWER TO AROUND 2500 FEET
AROUND MIDNIGHT AS THE PRECIP CONTINUES TO WEAKEN AND BECOME MORE
SCATTERED. RAIN SHOULD TAPER OFF FROM WEST TO EAST IN THE EARLY
MORNING HOURS ON FRIDAY WITH CEILINGS INCREASING AND CLOUDS
THINNING THROUGHOUT THE DAY.
PREV DISCUSSION... /ISSUED 313 PM CST THU FEB 21 2013/
DISCUSSION...
LATEST RADAR IMAGERY SHOWING THE WIDESPREAD RAINFALL MASSING WITH
THE LEADING EDGE APPROACHING I-65. LITTLE IN THE WAY OF LIGHTNING
RETURNS ACROSS WESTERN TN. HOWEVER...WE ARE GETTING SOME ACTIVITY
ALONG AND WEST OF THE MS RIVER. SOUTHWARD SUPPRESSION OF THE
INSTABILITY AXIS HAS OCCURRED OVER THE PAST FEW HOURS HOWEVER. THE
WIDESPREAD RAINFALL EXTENDS WESTWARD THROUGH CENTRAL AR.
THE ASSOCIATED STRONG UPPER LEVEL SYSTEM IS TRACKING ACROSS KANSAS
WITH A NORTHEASTWARD MOVEMENT. THUS...A TRACK THIS FAR TO OUR
NORTHWEST WILL LEAVE TN ON THE WARMER SIDE OF THE STORM SYSTEM AND
WE WILL CONTINUE TO SEE WET BULB TEMPS INCH UPWARD. RIGHT
NOW...THOSE WET BULB TEMPS ARE ABOVE FREEZING ACROSS THE
SOUTHWESTERN HALF OF THE MID STATE. CURRENT TEMPS ARE IN THE 40S FOR
MOST AREAS.
TONIGHT...THE RAINFALL WILL OVERSPREAD THE AREA. STILL EXPECTING
THE SHOWALTER AND THETA E INSTABILITY AXES TO MOVE ACROSS THE AREA
OVERNIGHT. SO...TSTMS WILL BE INCLUDED AS WELL. THE SHOWERS WILL END
BY FRIDAY MORNING BUT WILL LIKELY CONTINUE A SLIGHT CHANCE ACROSS
THE PLATEAU FOR FRIDAY MORNING.
PARTIAL CLEARING EXPECTED DURING THE DAY ON FRIDAY AS SOME OF THE
HIGHER CLOUDINESS HANGS ON. LOOKS LIKE A DRY BUT MILD DAY AS HEIGHTS
ARE ON THE INCREASE.
ON FRIDAY NIGHT...SOME PATCHY FOG WILL BE POSSIBLE LATE. SKIES WILL
BE PARTLY CLOUDY BUT DEWPOINTS WILL REMAIN SOMEWHAT ELEVATED. TOVER
VALUES WILL BE FAVORABLE FOR SOME PATCHY FOG DEVELOPMENT. MILD
CONDITIONS AGAIN FOR SATURDAY UNDER PCLDY SKIES.
IN THE EXT FCST...AFTER A COLD FRONT BRINGS A CHANCE OF SHOWERS TO
THE AREA ON MONDAY...WE THEN TRANSITION TO SOMEWHAT COLDER TEMPS AND
A SEMI-UNSETTLED REGIME. EURO AND GFS BOTH IN SUPPORT OF A GENERAL
TROUGHING PATTERN IN THE EAST WITH A FEW WEAK UPPER LEVEL SYSTEM
TRAVERSING THE AREA. NOTHING MUCH IN TERMS OF WINTRY WEATHER TO GET
EXCITED ABOUT AT THIS POINT. HOWEVER...I WILL ELECT TO PLACE A
RAIN/SNOW MIX IN THE FCST FOR WED NT. POPS WILL BE LOW FOR NOW.
VERSUS THE MEX GUIDANCE...SLIGHT UNDERCUTS THROUGH THE EXTENDED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
11
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1153 PM CST THU FEB 21 2013
.UPDATE...
LATEST RADAR IMAGERY SHOWS RAIN CONTINUES TO QUICKLY MOVE OUT OF
THE FORECAST AREA...AND IS NOW GENERALLY CONFINED TO ALONG AND
EAST OF THE I-65 CORRIDOR. WILL LOWER POPS SIGNIFICANTLY FOR THE
REST OF THE NIGHT AND REMOVE MENTION OF THUNDER. NO OTHER CHANGES
AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 816 PM CST THU FEB 21 2013/
UPDATE...
LATEST RADAR IMAGERY SHOWS LARGE AREA OF LIGHT TO MODERATE RAIN
ACROSS THE MID STATE...BUT BACK EDGE CAN BE SEEN NOW EAST OF THE
MISSISSIPPI RIVER. HRRR TIMING INDICATES MOST OF THE RAIN WILL
LIKELY END WEST OF I-65 AROUND MIDNIGHT...WITH SOME RAIN
CONTINUING THROUGH THE NIGHT TO THE EAST. HAVE ADJUSTED POPS
DOWNWARD IN THE 06-12Z TIMEFRAME WITH CHANCE POPS IN THE WEST TO
CATEGORICAL IN THE EAST. WILL ALSO ADD MENTION OF ISOLATED THUNDER
TO THE SOUTHWEST HALF OF THE CWA THIS EVENING AS A FEW LIGHTNING
STRIKES HAVE BEEN NOTED FROM TIME TO TIME.
TEMPERATURES CURRENTLY RANGE FROM THE MID 30S ALONG THE KY BORDER
TO THE MID 40S ALONG THE AL BORDER. THESE VALUES WILL BE THE LOWS
FOR TONIGHT AS WAA CONTINUES TO INCREASE THROUGH THE NIGHT AND
TEMPERATURES WARM WELL INTO THE 40S AREAWIDE BY SUNRISE AND
POSSIBLY 50S IN OUR SOUTHERN ZONES. MADE MINOR ADJUSTMENTS TO
TEMPS BUT NO OTHER CHANGES ATTM.
PREV DISCUSSION... /ISSUED 657 PM CST THU FEB 21 2013/
UPDATE...FOR 00Z TAFS...
AVIATION...
LIGHT TO MODERATE RAIN SHOWERS CONTINUE TO MOVE ACROSS THE MID
STATE THIS EVENING..WITH OBS INDICATING A FEW LIGHTNING STRIKES IN
THE STRONGER CELLS. CEILINGS ARE EXPECTED TO LOWER TO AROUND 2500 FEET
AROUND MIDNIGHT AS THE PRECIP CONTINUES TO WEAKEN AND BECOME MORE
SCATTERED. RAIN SHOULD TAPER OFF FROM WEST TO EAST IN THE EARLY
MORNING HOURS ON FRIDAY WITH CEILINGS INCREASING AND CLOUDS
THINNING THROUGHOUT THE DAY.
PREV DISCUSSION... /ISSUED 313 PM CST THU FEB 21 2013/
DISCUSSION...
LATEST RADAR IMAGERY SHOWING THE WIDESPREAD RAINFALL MASSING WITH
THE LEADING EDGE APPROACHING I-65. LITTLE IN THE WAY OF LIGHTNING
RETURNS ACROSS WESTERN TN. HOWEVER...WE ARE GETTING SOME ACTIVITY
ALONG AND WEST OF THE MS RIVER. SOUTHWARD SUPPRESSION OF THE
INSTABILITY AXIS HAS OCCURRED OVER THE PAST FEW HOURS HOWEVER. THE
WIDESPREAD RAINFALL EXTENDS WESTWARD THROUGH CENTRAL AR.
THE ASSOCIATED STRONG UPPER LEVEL SYSTEM IS TRACKING ACROSS KANSAS
WITH A NORTHEASTWARD MOVEMENT. THUS...A TRACK THIS FAR TO OUR
NORTHWEST WILL LEAVE TN ON THE WARMER SIDE OF THE STORM SYSTEM AND
WE WILL CONTINUE TO SEE WET BULB TEMPS INCH UPWARD. RIGHT
NOW...THOSE WET BULB TEMPS ARE ABOVE FREEZING ACROSS THE
SOUTHWESTERN HALF OF THE MID STATE. CURRENT TEMPS ARE IN THE 40S FOR
MOST AREAS.
TONIGHT...THE RAINFALL WILL OVERSPREAD THE AREA. STILL EXPECTING
THE SHOWALTER AND THETA E INSTABILITY AXES TO MOVE ACROSS THE AREA
OVERNIGHT. SO...TSTMS WILL BE INCLUDED AS WELL. THE SHOWERS WILL END
BY FRIDAY MORNING BUT WILL LIKELY CONTINUE A SLIGHT CHANCE ACROSS
THE PLATEAU FOR FRIDAY MORNING.
PARTIAL CLEARING EXPECTED DURING THE DAY ON FRIDAY AS SOME OF THE
HIGHER CLOUDINESS HANGS ON. LOOKS LIKE A DRY BUT MILD DAY AS HEIGHTS
ARE ON THE INCREASE.
ON FRIDAY NIGHT...SOME PATCHY FOG WILL BE POSSIBLE LATE. SKIES WILL
BE PARTLY CLOUDY BUT DEWPOINTS WILL REMAIN SOMEWHAT ELEVATED. TOVER
VALUES WILL BE FAVORABLE FOR SOME PATCHY FOG DEVELOPMENT. MILD
CONDITIONS AGAIN FOR SATURDAY UNDER PCLDY SKIES.
IN THE EXT FCST...AFTER A COLD FRONT BRINGS A CHANCE OF SHOWERS TO
THE AREA ON MONDAY...WE THEN TRANSITION TO SOMEWHAT COLDER TEMPS AND
A SEMI-UNSETTLED REGIME. EURO AND GFS BOTH IN SUPPORT OF A GENERAL
TROUGHING PATTERN IN THE EAST WITH A FEW WEAK UPPER LEVEL SYSTEM
TRAVERSING THE AREA. NOTHING MUCH IN TERMS OF WINTRY WEATHER TO GET
EXCITED ABOUT AT THIS POINT. HOWEVER...I WILL ELECT TO PLACE A
RAIN/SNOW MIX IN THE FCST FOR WED NT. POPS WILL BE LOW FOR NOW.
VERSUS THE MEX GUIDANCE...SLIGHT UNDERCUTS THROUGH THE EXTENDED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
345 AM CST FRI FEB 22 2013
.SHORT TERM...
AT THIS TIME NO SIGNIFICANT CHANGES IN SHORT TERM FORECAST AS
SYSTEM GENERALLY BEHAVING AS MODELS HAVE PROJECTED.
STRONG UPPER-LEVEL CIRCULATION CURRENTLY LOCATED OVER SOUTHWEST
IOWA IS CONSISTENT WITH 00Z MODEL FORECASTS. BANDS OF MODERATE
SNOW CONTINUE TO DEVELOP IN BROAD FGEN ZONE AND WAA OVER SOUTHERN
WISCONSIN AND ARE SPREADING QUICKLY NORTHWARD. LEADING EDGE OF MODERATE
SNOWFALL...AT 330 AM...EXTENDS FROM ABOUT KEWAUNEE TO GREEN
BAY...WESTWARD TO MOSINEE. VISIBLITIES ALONG HIGHWAY 29 SOUTHWARD
HAVE BEEN RANGING FROM 1 TO 1/2 MILE. HRRR FORECAST REFLECTIVITY
DATA CONSISTENT WITH CURRENT RADAR TRENDS. HRRR SHORT-TERM
FORECAST SUGGEST INITIAL MODERATE SNOWBAND WILL PUSH NORTH TO
ABOUT SUE-RHI BY 12Z...THEN WEAKEN SOMEWHAT BY TIME IT REACHES THE
WISCONSIN-MICHIGAN BORDER BY AROUND 14Z. LATEST MODEL GUIDANCE
ALSO A BIT COLDER AT 925/850MB COMPARED TO PREVIOUS RUNS...LENDING
MORE SUPPORT TO SOME LAKE ENHANCEMENT IN THE EAST. RADAR TRENDS
OVER LAKE MICHIGAN DO SEEM TO SUPPORT THIS. NOTE THAT BOUNDARY
LAYER WINDS NOT IDEAL WITH A BIT TOO MUCH DIRECTIONAL SHEAR AND
OVERWATER INSTABLITY WILL DECREASE DURING THE MORNING AS WAA
CONTINUES THUS LAKE CONTRIBUTION NOT EXPECTED TO BE SIGNIFICANT.
NEED TO WATCH THE PROGESS OF THE MID-LEVEL DRY INTRUSTION NOW
ENTERING SOUTHERN WISCONSIN. LATEST MODEL GUIDANCE DOES NOT
SUGGEST A CLEAN DRY SLOT WILL BE ABLE TO PUSH NORTHEAST INTO THE
SOUTHERN PORTION OF THE FORECAST AREA LATE THIS MORNING. IN FACT
THE HIGHER RESOLUTION WRF ARW/NMM AND HRRR SUGGEST THAT A COUPLE
SOMEWHAT WEAKER SNOWBANDS WILL LIKELY DEVELOP OVER SOUTHWEST
WISCONSIN LATER THIS MORNING AND ALSO PUSH INTO THE FORECAST AREA
INTO THE AFTERNOON. DAY-SHIFT WILL NEED TO MONITOR THIS EVOLUTION.
IF SOME MID-LEVEL DRYING IS ABLE TO PUNCH INTO THE SOUTHERN
PORTION OF THE FORECAST AREA...COULD SEE BRIEF PERIOD OF FREEZING
DRIZZLE LATER THIS MORNING. IF THIS DOES OCCUR...PROBABALY NOT A
HUGE IMPACT ON ROADS AS THEY WILL LIKELY BE SNOW-COVERED ANYWAY.
BOTTOM LINE IS THAT ADVISORY STILL LOOKS GOOD WITH 3 TO 5 INCH
AMOUNTS EXPECTED BY EARLY THIS EVENING. WITH WEAKENING UPPER
SYSTEM LINGERING INTO SATURDAY MORNING...COULD BE AN ADDITIONAL
INCH OR TWO...ESPECIALLY NORTH OF HIGHWAY 29...AND PERHAPS OVER
THE FAR NORTHEAST PORTION OF THE FORECAST AREA WHERE LINGERING
MODEST VERTICAL MOTION WILL PERSIST INTO THIS EVENING.
WINDS TO REMAIN STRONG FROM THE EAST THROUGH THE MORNING HOURS
AHEAD OF SURFACE LOW. 925 MB WINDS OF 25 TO 35 KNOTS EXPECTED
RESULT IN SURFACE WINDS OF 15 TO 25 MPH WITH HIGHER GUSTS
ESPECIALLY NEAR LAKE MICHIGAN. VISIBILITIES WILL BE LIMITED IN
SNOW AND BLOWING SNOW THIS MORNING. STILL EXPECT HIGHEST SNOWFALL
RATES TO OCCUR THROUGH ABOUT MID-DAY...THEN LOWER THEREAFTER.
EXPECT CONTINUED CYCLONIC FLOW ASSOCIATED WITH UPPER LOW FORECAST
TO DRIFT ACROSS THE FORECAST AREA...AND SUFFICIENTLY DEEP
MOISTURE TO REMAIN IN PLACE TO KEEP PERIODS OF LIGHT SNOW THROUGH
MUCH OF TONIGHT AND INTO SATURDAY. GFS HINTS THAT ADDITIONAL
SHORTWAVE ENERGY TO MOVE THROUGH ON BACKSIDE OF WEAKENING UPPER
LOW SATURDAY AFTERNOON...THOUGH OTHER MODELS NOT AS SUPPORTIVE IN
THAT REGARD. WILL GO WITH MORE SCATTERED WORDING FOR THAT DAY
PERIOD.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
EXPECT SOME LIGHT SNOW SHOWERS OR FLURRIES TO PERSIST ACROSS THE
NORTHERN PART OF THE FORECAST AREA ON SATURDAY NIGHT AS THE
CURRENT STORM SYSTEM CONTINUES TO MOVE AWAY FROM WISCONSIN. AFTER
THAT THERE WILL BE A PERIOD OF DRY WEATHER...THROUGH SUNDAY
NIGHT...WITH SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE OVER
THE STATE.
CONFIDENCE IS LOW REGARDING THE NEXT STORM SYSTEM EXPECTED TO
IMPACT THE AREA. THERE WERE SIGNIFICANT DIFFERENCES AMONG THE
MODELS IN THEIR HANDLING OF THE SYSTEM. THIS HAS RESULTED IN A
FORECAST OF CHANCE POPS MONDAY NIGHT THROUGH WEDNESDAY...FOR NOW.
HOPEFULLY MODELS WILL CONVERGE ON A SIMILAR SOLUTION WITHIN THE
NEXT COUPLE OF DAYS.
LOW TEMPERATURES ON SUNDAY NIGHT MAY NEED TO BE LOWERED DUE TO
FRESH SNOW AND LIGHT WINDS...BUT NOT SURE WHETHER CLOUDS WILL HANG
AROUND THE AREA SO DID NOT GO TOO COLD. OTHERWISE TEMPERATURES
SHOULD BE AT OR ABOVE NORMAL WITH MAINLY SOUTHWEST OR ZONAL UPPER
FLOW THE REST OF THE PERIOD.
&&
.AVIATION...LOOK FOR DETERIORATING CONDITIONS OVERNIGHT AS SNOW
MOVES INTO THE REGION. VISBYS EXPECTED TO DROP QUICKLY AS SNOW
MOVES IN...WITH IFR OR LIFR CONDITIONS EXPECTED THROUGH THE
MORNING HOURS. 3 TO 5 INCHES OF SNOW EXPECTED IN MOST PLACES WITH
GUSTY WINDS PRODUCING SOME BLOWING AND DRIFTING ESPECIALLY AT
SUE/MTW/GRB/ATW/OSH FRIDAY MORNING. LOOK FOR LONG DURATION/INTO
SAT/ OF LIGHT SNOW OR FLURRIES AS UPPER LEVEL LOW PRESSURE SYSTEM
LIFTS NORTH THROUGH STATE.
TE
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR
WIZ018>021-030-031-035>040-045-048>050-074.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ005-
010>013-022-073.
&&
$$
ESB/MG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1123 PM CST THU FEB 21 2013
.SHORT TERM...
909 PM CST THU FEB 21 2013
SNOW WAS BREAKING OUT ACROSS NORTHEAST IOWA...WITH A DUSTING BEING
REPORTED IN THE EDGEWOOD AREA OF FAYETTE COUNTY. 22.00Z HRRR
CONTINUES TO PUSH THIS BAND OF SNOW NORTHEAST ACROSS THE FORECAST
AREA THROUGH THE REMAINDER OF THE EVENING...WITH AREAS NORTH
OF INTERSTATE 94 MOST LIKELY TO SEE THE SNOW BREAK OUT BETWEEN
06Z-09Z. 22.00Z NAM ALSO IN LINE WITH THIS TREND AS WELL. WILL BE
MAKING JUST SOME MINOR TWEAKS TO THE GRIDS BASED ON CURRENT TRENDS.
SOME CONCERN AS TO SNOW AMOUNTS ACROSS NORTHEAST IOWA THROUGH 06Z.
REPORTS BACK IN DMX AREA SHOWS GENERALLY 1 TO 3 INCHES HAVE
FALLEN. 22.00Z HRRR SHOWS THE LIGHTER SNOW AREAS TO FILL IN LATER
THIS EVENING AS IT LIFTS NORTHEAST. IF THIS OCCURS THEN WILL
REALIZE THE 2 TO 3 INCHES WE HAVE ACROSS FLOYD COUNTY. OTHERWISE
SNOW AMOUNTS THROUGH 06Z MAY BE A BIT HIGH. NONE THE LESS STILL
EXPECTING LOW END WARNING CRITERIA TO BE MET IN MUCH OF NORTHEAST
IOWA...WITH THE 4 TO 6 INCHES LIKELY ELSEWHERE.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
306 PM CST THU FEB 21 2013
21.12 MEDIUM RANGE MODELS ARE SHOWING SOME DIFFERENCES REGARDING THE
EVOLUTION OF THE TROUGH SUNDAY NIGHT THROUGH TUESDAY. THE GFS WRAPS
THE TROUGH INTO AN UPPER LOW OVER THE UPPER MIDWEST. THE ECMWF TAKES
THE TROUGH INTO THE CENTRAL AND SOUTHERN PLAINS AND DEEPENS INTO AN
UPPER LOW. THE GFS TAKES THE LOW EAST OVER SOUTHERN WISCONSIN ON
MONDAY WHILE THE ECMWF TAKES IT THROUGH THE OHIO RIVER VALLEY. THIS
SYSTEM HAS THE POTENTIAL TO BRING ACCUMULATING SNOW THE AREA BUT
THERE IS CONSIDERABLE UNCERTAINTY WITH THE STORM TRACK. HAVE LEANED
TOWARD A MODEL CONSENSUS BLEND SUNDAY NIGHT THROUGH TUESDAY. THE LOW
LOOKS TO MERGE WITH A SOUTHERN STREAM SYSTEM TUESDAY INTO WEDNESDAY
STALLING OVER THE EASTERN GREAT LAKES REGION. CYCLONIC FLOW IS
EXPECTED TO SET UP OVER THE FORECAST AREA ON THE WESTERN SIDE OF THE
LOW. EMBEDDED SHORTWAVES WILL BRING CHANCES FOR LIGHT SNOW TO THE
AREA WEDNESDAY INTO THURSDAY.
&&
.AVIATION...THROUGH 06Z SATURDAY
1123 PM CST THU FEB 21 2013
SNOW IS SPREADING INTO THE TAF SITES AND EXPECT CEILINGS AND
VISIBILITIES TO DROP RAPIDLY OVER THE NEXT HOUR INTO THE
IFR AND PERHAPS LIFR CATEGORY. EXPECT THESE CONDITIONS TO THEN
PERSIST THROUGH AT LEAST 14Z BEFORE A VERY GRADUAL INCREASE IN
VISIBILITIES ARE EXPECTED AS THE SNOW RATES BEGIN TO
DIMINISH...WITH VISIBILITIES STILL IN THE 1-2SM RANGE THROUGH 06Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 PM CST THU FEB 21 2013
WI...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR WIZ041-053>055-061.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY
FOR WIZ017-029-032>034-042>044.
MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR MNZ079-086>088-094>096.
IA...WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST FRIDAY
FOR IAZ008>010-018-019-029-030.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR IAZ011.
&&
$$
SHORT TERM...RABERDING
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1037 AM EST FRI FEB 22 2013
.UPDATE...
BULK OF PRECIP HAS SHIFTED TO THE SOUTHEAST PART OF THE CWA AND
MAIN UPDATE TO THE FORECAST WAS DECREASE PRECIPITATION ACROSS
NORTH GEORGIA. GIVEN LOW CLOUDS...MOISTURE AND VERY LIGHT RETURNS
ON RADAR...HAVE MENTIONED DRIZZLE ACROSS NORTH GEORGIA FOR THIS
MORNING. ALTHOUGH PRECIP WILL CONTINUE ACROSS THE SOUTHEAST
PORTION OF THE CWA THROUGH THE AFTERNOON...THE HRRR HOLDS OFF ON
BRINGING BETTER RAIN CHANCES BACK INTO THE ATL METRO AREA UNTIL
LATE THIS AFTERNOON. OTHER HI RES MODELS SUGGEST A LATER TIME
FRAME WITH THE BETTER POPS BEGINNING TONIGHT FOR THE ATL AREA.
CURRENT FORECAST TRENDS TOWARD THE TIMING OF THE HRRR...BUT MAY
STILL BE ON THE EARLY SIDE.
MU CAPE THROUGH THE AFTERNOON IS AROUND 400 J/KG. WITH LIMITED
LIGHTNING STRIKES THIS MORNING...HAVE OPTED TO SHOW ISOLATED
THUNDER THROUGH 18Z AND THEN SCATTERED THUNDER FOR THE AFTERNOON
WITH THE BETTER HEATING OF THE DAY.
HAVE SEEN ONE RIVER SITE /CUMMING/ GO INTO FLOOD THIS MORNING BUT
WITH BULK OF PRECIP EXPECTED OVERNIGHT...THINK MOST HYDRO PROBLEMS
SHOULD HOLD OFF UNTIL TONIGHT.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 410 AM EST FRI FEB 22 2013/
GEORGIA REMAINS UNDER PERSISTENT SOUTHWESTERLY UPPER FLOW THROUGH
THE FORECAST. MAIN UPPER LOW/SHORT WAVE TRACK REMAINS WELL NORTH
OF THE STATE...HOWEVER RICH MOISTURE FEED...STALLED FRONTAL BOUNDARY
AND A SERIES OF WEAK TO MODERATE SHORT WAVES AND ASSOCIATED SURFACE
LOWS CONTINUE TO TRACK ACROSS THE REGION THROUGH THE SHORT TERM
FORECAST PERIOD. INSTABILITY REMAINS MARGINAL AND NO WIDESPREAD
SEVERE THUNDERSTORMS ARE EXPECTED...HOWEVER THE ACTIVITY ALONG AND
SOUTH OF THE FRONT WILL NEED TO BE WATCHED FOR THE POTENTIAL FOR
ISOLATED SEVERE WEATHER. MAIN THREAT CONTINUES TO BE THE PERSISTENT
HEAVY RAIN AND FLOODING POTENTIAL. AREA OF SHOWERS AND A FEW
THUNDERSTORMS CURRENTLY ALONG THE FRONT SINKS INTO CENTRAL GEORGIA
TAKING THE BETTER PRECIPITATION TOTALS WITH IT...BUT WIDESPREAD
LIGHT TO OCCASIONALLY MODERATE RAIN IS STILL POSSIBLE OVER THE
NORTH. RAINFALL RATES DIMINISH SOMEWHAT TODAY BUT HEAVY RAIN WILL
MOVE UP THE FRONTAL BOUNDARY AGAIN TONIGHT AND EARLY SATURDAY AS THE
NEXT WAVE SWEEPS UP THE FRONTAL BOUNDARY. STILL LOOKS LIKE A BIT OF
A BREAK IN THE ACTION SATURDAY NIGHT AS THE SHORT WAVE EXITS AND THE
FRONTAL BOUNDARY...AT LEAST TEMPORARILY... SINKS SOUTH OF THE
FORECAST AREA.
LATEST QPF REMAINS IN LINE WITH PREVIOUS TRENDS SO I DO NOT PLAN ON
ADJUSTING THE CURRENT FLOOD WATCH AT THIS TIME. CENTRAL GEORGIA HAS
THE POTENTIAL TO SEE OVER 4 INCHES OF RAIN BY EARLY SUNDAY MORNING
WITH SLIGHTLY LOWER BUT STILL SIGNIFICANT AMOUNTS OVER 2 INCHES
ALONG THE I-20/I-85 CORRIDOR.
20
LONG TERM /SUNDAY THROUGH THURSDAY/...
/ISSUED 410 AM EST FRI FEB 22 2013/
LONG TERM FORECAST REMAINS FULL OF ACTIVITY. THE FIRST SYSTEM IS
EXPECTED TO AFFECT THE CWA ON MONDAY AND POSSIBLY INTO TUESDAY. I
HAVE WORKED THREE SHIFTS ON THIS DESK HOPING THAT THE GUIDANCE
WOULD COME TO A CONSENSUS OR START CONVERGING ON A SOLUTION FOR
THIS SYSTEM. THEY HAVE NOT. THE EURO CONTINUES TO BE THE SLOWEST
OF ALL SOLUTIONS...AND IS FAVORED BY HPC. AS SUCH...DECIDED TO GO
WITH A THE EURO SOLUTION. THIS BRINGS THE WARM FRONT ACROSS THE
CWA DURING THE LATE AFTERNOON ON MONDAY. MOST OF CENTRAL GEORGIA
SHOULD BE IN THE WARM SECTOR. THE COLD FRONT IS EXPECTED TO
APPROACH THE CWA AROUND 06Z TUESDAY. DEPENDING ON HOW MUCH
MOISTURE RETURN CAN OCCUR IN THE WARM SECTOR...SBCAPES ARE
LOW...SO HAVE DECIDED TO INCLUDE A SLIGHT CHANCE FOR THUNDER. DEEP
LAYER SHEAR IS ABOUT 50 TO 80 KNOTS FROM SOUTH TO NORTH ACROSS THE
CWA...AND LOW LEVEL SHEAR LOOKS DECENT AT THIS TIME. THIS WILL
NEED TO BE WATCHED CLOSELY AS WE GET CLOSER TO THE EVENT.
THIS UPPER LEVEL LOW IS FORECAST TO CUTOFF ACROSS THE GREAT LAKES
REGION THROUGH THE REST OF THE PERIOD. COOLER AIR IS FORECAST TO
MOVE IN FROM THE NORTH AS SHORTWAVES CIRCULATE AROUND THE LOW. ONE
OF THESE SHORTWAVES COULD LEAD TO SOME PRECIP ACROSS NORTHERN
PORTIONS OF THE CWA LATER IN THE PERIOD.
ARG
AVIATION...
12Z UPDATE...
/ISSUED 635 AM EST FRI FEB 22 2013/
MIXTURE OF MVFR AND IFR CONDITIONS ACROSS THE FORECAST AREA WILL
CONTINUE THROUGH 00Z. ALL AREAS WILL TREND TOWARD IFR BY 06Z WITH
AREAS OF LIFR DEVELOPING AFTER 06Z. WINDS WILL REMAIN EASTERLY...
GENERALLY 6-10KT ALTHOUGH PERIODS OF GUSTY CONDITIONS WILL OCCUR
THROUGH AROUND 16-18Z ACROSS MOST AREAS. BEST PRECIPITATION
COVERAGE WILL BE ACROSS CENTRAL GEORGIA WITH SOME THUNDER POSSIBLE
THERE AS WELL. BETTER COVERAGE OF RAIN WILL EXPAND BACK NORTH
AFTER 00Z.
//ATL CONFIDENCE...12Z UPDATE...
CONFIDENCE IS MEDIUM ON ALL ELEMENTS.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 48 43 55 41 / 90 100 80 10
ATLANTA 52 46 59 39 / 80 100 80 10
BLAIRSVILLE 48 41 54 35 / 70 100 80 10
CARTERSVILLE 53 45 59 37 / 70 100 80 10
COLUMBUS 63 56 65 43 / 100 100 80 20
GAINESVILLE 49 42 54 40 / 80 100 80 10
MACON 62 54 64 43 / 100 100 90 20
ROME 55 45 60 35 / 60 90 70 10
PEACHTREE CITY 54 47 61 39 / 90 100 80 10
VIDALIA 70 58 69 51 / 100 100 80 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...BUTTS...CARROLL...
CHATTAHOOCHEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...
CRISP...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...FAYETTE...
FORSYTH...GLASCOCK...GREENE...GWINNETT...HALL...HANCOCK...
HARALSON...HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...MACON...
MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...MORGAN...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...
PAULDING...PEACH...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...
SCHLEY...SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TREUTLEN...TROUP...
TWIGGS...UPSON...WALTON...WARREN...WASHINGTON...WEBSTER...
WHEELER...WILCOX...WILKES...WILKINSON.
&&
$$
SHORT TERM...20/11
LONG TERM....ARG
AVIATION...20
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
533 AM CST FRI FEB 22 2013
.UPDATE...
DATA AT 11Z PLACES THE OCCLUDED LOW BETWEEN KOTM AND KTVK. RAP
MODEL TRENDS MOVE THE OCCLUDED LOW NORTHEAST INTO WISCONSIN BY MID
AFTERNOON. TRIPLE POINT MOVING UP THROUGH THE EASTERN CWFA MAY OR
MAY NOT SEE A WEAK WAVE DEVELOP ALONG IT.
THE CURRENT AREA OF -SN IN THE WESTERN CWFA IS EXPECTED TO
CONTINUE A SLOW DRIFT NORTHEAST AHEAD OF THE OCCLUDED LOW WHICH
SHOULD GENERATE SOME NEW ACCUMULATING AMOUNTS OF POTENTIALLY AN
INCH. IF THE RAP TRENDS ARE CORRECT THIS AREA OF -SN SHOULD EXIT
THE NORTHEAST CWFA EARLY THIS AFTERNOON.
AS FOR HEADLINES...WILL KEEP THEM IN PLACE FOR A FEW MORE HOURS.
HOWEVER...MORE OF THE AREA MAY BE CLEARED EARLY IF WHAT IS BEING
SUGGESTED BY THE RAP IS CORRECT. ..08..
&&
.AVIATION...
RAP MODEL TRENDS INDICATE THE SFC LOW WILL MOVE THROUGH EASTERN
IOWA TOWARD WISCONSIN. A WARM FRONT WILL MOVE THROUGH KBRL/KMLI
HELPING TO TURN WINDS SOUTH BEFORE BECOMING WEST WITH THE LOW
PASSAGE. IFR/MVFR CONDITIONS WILL CONTINUE THROUGH 00Z/23 WITH
POTENTIALLY LOWER VSBYS IN HEAVIER SHSN. AFT 00Z/23 ANY IFR
CONDITIONS WILL IMPROVE TO MVFR. ..08..
&&
.PREV DISCUSSION... /ISSUED 316 AM CST FRI FEB 22 2013/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE OCCLUDED LOW IN WEST CENTRAL MISSOURI
WITH A NEW TRIPLE POINT DEVELOPING JUST WEST OF KSTL. AN INVERTED
TROF RAN FROM THE OCCLUDED LOW INTO WESTERN IOWA. RADAR SHOWS THE
BULK OF THE MAIN SNOW MOVING NORTH INTO MN/WI. HOWEVER...VERY
LIGHT SNOW WAS BEING REPORTED AS FAR SOUTH AS MISSOURI. DEW POINTS
WERE IN THE TEENS AND 20S ACROSS MUCH OF THE MIDWEST WITH 30S AND
HIGHER FROM THE OHIO VALLEY ON SOUTH.
SHORT TERM...TODAY AND TONIGHT
RUNNING BEHIND DUE TO OTHER PROBLEMS. FIRST...BASED ON RAP TRENDS
WILL DROP HEADLINES FOR ROUGHLY THE SOUTHERN THIRD. THE OTHER
HEADLINES WILL CONTINUE FOR NOW BUT MAY GET CANCELLED OR MODIFIED
OVER THE NEXT 3-4 HRS.
RAP TRENDS INDICATE THE WAA WING OF SNOW WILL BE IN MN/WI SHORTLY.
FLURRIES OR VERY LIGHT SNOW IS SPORADIC ACROSS THE AREA BUT VERY
LITTLE IN THE WAY OF NEW ACCUMULATION SHOULD BE SEEN THROUGH 12Z.
DURING THE DAY THE RAP DEVELOPS NEW FORCING AS THE OCCLUDED LOW
MOVES UP THROUGH THE FAR WESTERN CWFA WHICH SHOULD INDUCE SOME NEW
LIGHT SNOW DURING THE DAY ACROSS THE AREA. CONDENSATION PRESSURE
DEFICITS WILL SLOWLY RISE SO THERE SHOULD BE A GRADUAL END TO THE
SNOW FROM SOUTH TO NORTH DURING THE DAY.
ADDITIONAL ACCUMULATIONS FOR THE REMAINDER OF THE DAY SHOULD RANGE
FROM A DUSTING TO PERHAPS AN INCH.
TONIGHT...CYCLONIC FLOW SHOULD CONTINUE TO KEEP LIGHT
SNOW/FLURRIES GOING ACROSS ROUGHLY THE NORTH/NORTHEAST THIRD OF
THE CWFA DURING THE EVENING THAT GRADUALLY ENDS DURING THE NIGHT.
BASED ON TEMPERATURES CURRENTLY IN MISSOURI...THE EASTERN CWFA
SHOULD SEE READING GET TO OR JUST ABOVE FREEZING DURING THE
DAYLIGHT HOURS. ..08..
LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
ANOTHER ACTIVE PERIOD IS LOOMING IN THE LONG TERM...WITH ALL MODELS
SHOWING A DYNAMIC SYSTEM MONDAY THROUGH MID WEEK. THERE IS PLENTY
OF MODEL SPREAD ON TIMING AND TRACK OF THIS SYSTEM...AS WELL AS ITS
EVENTUAL EVOLUTION INTO A MAJOR LONG WAVE TROF. THUS...FOR NOW...AND
WILL FULL SUPPORT OF THIS FORECASTER...WE WILL TAKE SOME BABY STEPS
TOWARD A WINTER EVENT...OF SNOW AND POTENTIALLY WIND. I AM
ENCOURAGED THAT BOTH THE 00Z ECMWF..UKMET...GEM...AND NAM ALL TAKE
THE SYSTEM SOUTH...WITH THE BEST TRACK FOR HEAVY QPF OVER CWAS JUST
SOUTH. NOT THAT THAT WILL OCCUR...BUT I FEEL THIS WINTER REPRESENT
YET ANOTHER YEAR THAT WE MODELS WILL EVENTUALLY TRACK SYSTEMS A BIT
FARTHER NORTH THAN THEIR DAY 3 TO 7 FORECASTS. THE GFS REMAINS MUCH
FARTHER NORTH...WEAKER...AND FASTER THAN OTHER MODELS...AND IT
LARGELY DISREGARDED EXCEPT FOR INSERTING SOME SLIGHT CHANCE POPS FOR
SUNDAY NIGHT. IN THE END...IT WOULD SEEM SLOWER IS THE WAY TO GO ON
THIS SYSTEM...ESPECIALLY SINCE IT IS ANOTHER CLOSED UPPER LOW
SYNOPTIC SYSTEM. IT TRENDS HOLD TRUE ON THE ECMWF AND OTHERS...WE
ARE CERTAIN TO NEED CATEGORICAL POPS FOR MONDAY NIGHT INTO TUESDAY.
TEMPERATURES WILL REMAIN SOMEWHAT COOLER THAN SEASONAL NORMALS
THROUGHOUT THE FORECAST PERIOD. THUS...WITH HIGHS IN THE LOWER TO
MID 30S MUCH OF THE FORECAST...WE WILL SLOWLY LOSE SNOW COVER IN
PERIODS WE ARE NOT GAINING IT. THIS SEEMS PRETTY TYPICAL FOR LATE
FEBRUARY IN MY EXPERIENCE.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR
CLINTON-JACKSON-SCOTT.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR BENTON-
BUCHANAN-CEDAR-DELAWARE-DUBUQUE-IOWA-JOHNSON-JONES-LINN-
MUSCATINE.
IL...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR BUREAU-
CARROLL-HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-
STEPHENSON-WHITESIDE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1019 AM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA TODAY WITH A LIGHT
WINTRY MIX MOSTLY COMING TO AN END THIS AFTERNOON AND LINGERING
DRIZZLE CONTINUING INTO THE EVENING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY...FOLLOWED BY BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE WAS ISSUED THIS MORNING BASED ON RECENT OBS...RADAR
TRENDS...AND MODEL SOUNDINGS THIS MORNING. PRECIP WAS CHANGED TO ALL
LIGHT FREEZING RAIN SOUTHWEST OF PITTSBURGH AND RAIN IN
NORTH-CENTRAL WV. THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO
EXPIRE IN NORTH-CENTRAL WV AND HAS BEEN CONTINUED IN EASTERN OHIO.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS IOWA. AT THE SURFACE...AN OCCLUDED FRONT EXTENDS
FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A WARM
EXTENDS EASTWARD ACROSS CENTRAL WV. 280-300K LAYER ISENTROPIC LIFT
IS PROVIDING FORCING FOR SCATTERED AREAS OF FREEZING RAIN NORTH OF
THE WARM FRONT THIS MORNING FOR LOCATIONS PRIMARILY NORTHEAST OF
A NEW PHILADELPHIA-WHEELING-MORGANTOWN LINE.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO LIFT NORTHWARD
INTO THE UPPER OHIO VALLEY WITH THE AREA OF ISENTROPIC LIFT LIFTING
NORTHEAST OF THE AREA AND BRINGING MEASURABLE MIXED PRECIPITATION
TO AN END. MODEL SOUNDINGS INDICATE THAT DRY AIR ABOVE 750MB WILL
PREVENT ANY DENDRITIC GROWTH INTO THE AFTERNOON...WITH THE LOWER
LEVELS REMAINING SATURATED. THUS...THIS SOUNDING IS FAVORABLE FOR
A DRIZZLE/FREEZING DRIZZLE SETUP. WITH THIS IN MIND...HAVE
EXTENDED THE WINTER WEATHER ADVISORY IN OHIO WITH TEMPS STILL
BELOW FREEZING AND ADDED MORE MENTION OF DRIZZLE/FZDZ ACROSS THE
AREA THIS EVENING. A LIGHT ICING HAS BEEN REPORTED ACROSS MOST OF
THE AREA AND HIRES MODELS SUPPORT AN ADDITIONAL FEW HUNDREDTHS OF
ICE ACCUMULATION IN WESTERN PA AND THE ALLEGHENY FRONT OF MD/WV.
HIGH TEMPS TODAY ARE A FEW DEGREES COOLER THAN LAMP
GUIDANCE...RANGING FROM THE LOWER 30S ACROSS THE I-80 CORRIDOR
AND LAUREL HIGHLANDS/ALLEGHENY FRONT TO MID 40S IN PORTIONS OF
EASTERN OHIO AND NORTH-CENTRAL WV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SOME PTCHY FZDZ COULD LINGER THIS EVE N OF I 80 AND IN THE RIDGES
WITH AMPLE LLVL MOISTURE. GFS TRIES TO BRING IN PCPN WITH A DVLPG
COASTAL LOW ACRS THE RIDGES SAT. NAM/ECMWF KEEP IT FURTHER E.
PREFER THE DRIER SOLNS GIVEN SE DOWNSLOPING WNDS...AND WITH DVLPG
SFC LOW CENTER SO FAR E ALG THE COAST. WK...DRY TROF/CDFNT MOVES
THRU SAT WITH COLD AIR ADVCTN SHSN PSBL SAT NT/SUN. HI PRES
RETURNS SUN NT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A FAIRLY ACTIVE PATTERN CONTINUES FOR THE START OF THE LONG TERM
WITH ALL OF THE MODELS HAVING ESSENTIALLY A COPY-CAT PATTERN TO
FRIDAYS SYSTEM. A DIGGING UPPER LEVEL TROUGH WILL SHIFT
NORTHEASTWARD THROUGH THE CENTRAL US...HEADING TO THE GREAT LAKES
WHILE ANOTHER LOW DEVELOPS ON THE EAST COAST. AT THIS TIME THE GFS
TENDS TO BE FASTEST WITH THE ECMWF THE SLOWEST. WITH SUCH
UNCERTAINTY IN TIMING...OPTED TO REMAIN NEAR THE GEFS MEAN AND THE
HPC GUIDANCE BUT DID TAKE INTO ACCOUNT THE HIGH MEX GUIDANCE SIGNALS
MON NGT/TUES. BEYOND TUESDAY...MODEL SOLUTIONS DIVERGE COMPLETELY SO
OPTED TO REMAIN CLOSE TO HPC GUIDANCE WITH A DEEP TROUGH KEEPING THE
WEATHER UNSETTLED THROUGH THURSDAY. TEMPERATURES WERE GENERALLY KEPT
NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA BRIEFLY MIXING WITH SLEET WILL VACATE THE AREA BY 17Z
OWING TO SPOTTY DZ AND FZDZ THE BALANCE OF THE AFTERNOON. IFR CIGS
ARE EXPECT FOR A SHORT PERIOD AT ZZV THRU 16Z...OTHERWISE MOST SITES
SHALL STAY MVFR THROUGH THE BALANCE OF THE FORECAST.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR OHZ039-048-
049-057>059-068-069.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ040-
041-050.
PA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR PAZ031.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-013>016-022-023-074-076.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ020-
021-029-073-075.
WV...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ003-004.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
WVZ023-041.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ001-
002.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...98
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
620 AM EST FRI FEB 22 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY WEAKEN OVER THE REGION THROUGH
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE CENTRAL GULF COAST
STATES. THE LOW WILL TRACK NORTHEAST TO OFF THE VIRGINIA COAST
TONIGHT THROUGH SATURDAY. HIGH PRESSURE RETURNS TO THE MID
ATLANTIC STATES SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DRY AIR OVR THE FA HOLDING ON ATTM. SPLIT IN PCPN AS IT HAS
ENTERED THE RGN HAS OCCURRED...W/ ONLY VRY SPOTTY/LGT PCPN FM
CNTRL VA ON S INTO INTR NE NC. HAVE CONTEMPLATED LWRG THE WINTER
WX ADSVRY...THOUGH CONTG TO WATCH AN AREA OF PCPN MOVING THROUGH
WCNTRL VA (FM THE MTNS) IN THE PAST HR OR TWO WHICH MAY HOLD
TOGETHER INTO PORTIONS OF THE ADVSRY AREA. TEMPS RMN AT OR SLGTLY
ABV FRZG MOST PLACES. HV MADE MINOR ADJSTMNTS TO POPS/TEMPS BASED
ON TRENDS AND LATEST LAV GUID.
PREV DISCUSSION:
SFC HI PRES (NR 1030MB) RMNS WEDGED OVR THE FA...RESULTING IN MDT
CAD. DEWPTS RMN IN THE TEENS OVR THE FA ATTM. PCPN SPREADING EWD
THROUGH SW VA AND WRN/CNTRL NC AS WEAKENING MID LVL S/W MOVES INTO
THE CNTRL MTNS. THE PCPN IS ENCOUNTERING THE SUBSTANTIAL LO LVL
DRY AIR IN PLACE THIS FAR E OF THE MTNS. ADDITIONALLY...RECENT
TRENDS IN RADAR SUGGEST THAT THE GFS/RUC IDEA OF A SPLIT IN THE
PCPN (ONE AREA PUSHING N INTO NRN WV/NW VA AND WRN PA...THE OTHER
MOVING E ACRS NC/EXTREME SW VA) IS CORRECT. SO FAR...ROA/LYH AND
HSP HAVE RECEIVED NO PCPN...AND THAT MAY SUGGEST THAT ANY
WIDESPREAD PCPN WILL BE DIFFICULT TO REACH CNTRL AND ERN VA
THROUGH THE ERY MRNG/MIDDAY HRS. 00Z GFS AND 03Z RUC BOTH ONLY
BRING ABT A HUNDREDTH OR TWO INTO CNTRL AND NRN SECTIONS OF THE
FA...W/ HIGHEST QPF (THOUGH ONLY TO ABT 0.05" ON AVG) TO AREAS
NR/S OF THE VA/NC BORDER IN INTR SRN VA/NE NC. MDL SNDGS HAVE
SUBSTANTIAL DRYING AOA 700MB BY MID/LT MRNG HRS ACRS THE FA...AND
CONT THAT THROUGH THE AFTN...POINTING TO ONLY LGT/SPOTTY PCPN ACRS
THE FA AS TEMPS RISE ABV FRZG (LASTLY PTNTLLY OVR THE FAR NW PDMNT
CTYS WHERE TEMPS XPCD TO HOVER NR FRZG ALL DAY).
PTYPE IS THE OTHER CONCERN...WILL HAVE CHCS FOR SN/IP AS WELL AS
FRZG RA (AGN AMTS VRY LGT...AND INCRSGLY SPOTTY THROUGH THE
ERY/MID MRNG HRS). WILL KP WINTER WX ADSVRY AS IS FOR NOW...AND
MONITOR TRENDS THROUGH ERY MRNG. ANY ACCUMS (ESP ICE)...GENLY AOB
0.01-0.02". SPOTTY LGT RA AND/OR DZ FM MIDDAY THROUGH THE AFTN
HRS...AGN QPF QUITE LGT (LESS THAN 0.05") THROUGHOUT.
HI TEMPS FM NR 32F FAR NW TO L40S FAR SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
HIGHER CONFIDENCE/PROB FOR PCPN TNGT FM SW TO NE AS LO PRES FM
THE CNTRL GULF STATES TRACKS NE THROUGH GA/SC/NC. INCRSD POPS TO
80-100% ACRS MUCH OF THE AREA OVRNGT...W/ 60-80% FAR NNE SECTIONS.
HI PROB (90-100% POPS) OVR ENTIRE FA SAT MRNG. THE LO REACHES OFF
THE VA CST SAT AFTN/EVE LEADING TO A GRADUAL LWRG OF POPS FM WSW
TO E (THOUGH CLDNS WILL HANG ON). STM TOTAL QPF RANGING FM
0.25-0.50" NW TO 1-1.5" SE. TEMPS HOLD NRLY STEADY OR ONLY RISE A
CPL/FEW DEGS F INLAND...WHILE CLOSE TO THE CST...ESP SE VA/NE
NC...TEMPS RISE INTO/THROUGH THE 40S. HI TEMPS SAT M40S NW TO
M/U50S SE VA/NE NC.
SLOLY DRYING OUT BY LT SAT NGT/ERY SUN. SFC HI PRES BUIDS TWD THE
RGN FM THE NW ON SUN LEADING TO SUBSTANTIAL CLRG (AND MNLY SUNNY)
AND MILD CONDS. HI TEMPS 50-55F N TO 55-60F S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE BUILDS IN FROM THE WEST ON SUNDAY WITH DRY CONDITIONS
INTO SUNDAY NIGHT. A NEGATIVELY TILTED UPPER LEVEL RIDGE AMPLIFIES
OVER THE REGION ON MONDAY IN RESPONSE TO A BROAD UPPER LEVEL TROUGH
DIGGING OVER THE CTRL PLAINS. WEAK ENERGY FLOWING AROUND THE BASE OF
THE AFOREMENTIONED TROUGH IS EXPECTED TO MOVE NE ACROSS THE SE
STATES AS SW FLOW DEVELOPS ALOFT. THIS ENERGY AND ASSOCIATED
PRECIPITATION (ALL RAIN) IS THEN EXPECTED TO MOVE THROUGH THE MID
ATLANTIC REGION MONDAY NIGHT INTO TUESDAY. THERE WERE INDICATIONS OF
A COASTAL LOW DEVELOPING TUESDAY NIGHT ONCE IT MOVES OVER THE WATER
AND THIS TREND HAS CONTINUED...HOWEVER THERE ARE NOW MORE ADVERSE
TIMING DIFFERENCES BTWN VARIOUS 12Z MODEL RUNS. WILL TREND THE
FORECAST BTWN THE TWO MODELS FOR THE TIME BEING. A BROAD UPPER
TROUGH BECOMES ANCHORED OVER THE NE CONUS THE REMAINDER OF THE
WEEK...KEEPING CONDITIONS COOL AND UNSETTLED.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
SHORTWV ENERGY WILL PUSH ACRS THE AREA THIS MORNG INTO EARLY THIS
AFTN...AND MAY BRING A MIX OF LIGHT SLEET...SNOW OR FREEZING RAIN.
OTHRWISE...CLDS WILL THICKEN AND LWR DURING TODAY...AS WINDS
BECOME ESE WELL AHEAD OF LO PRES DEVELOPING OVR THE GULF CST
STATES. MVFR/IFR CIGS/VSBYS THEN LIKELY THIS EVENG INTO SAT
NGT...AS THE LO MOVES UP ALNG AND JUST OFF THE CST...BRINGING
RAIN TO THE AREA. DRY/VFR CONDITIONS RETURN SUN INTO MON...AS
HI PRES BLDS IN FM THE W.
&&
.MARINE...
NO HEADLINES IN THE MARINE AREA THRU TNGT...BUT WILL LIKELY NEED
TO ISSUE SCA`S FOR AT LEAST THE CHES BAY AND CSTL ZNS FOR SAT INTO
EARLY SUN...DUE TO LO PRES MOVNG UP ALNG AND JUST OFF THE CST. N
WINDS 10 TO 15 KT EARLY THIS MORNG...WILL BECOME ESE 10 KT OR LESS
THIS AFTN. ESE WINDS 10 TO 20 KT AND GUSTY THEN EXPECTED LATER
TNGT INTO SAT AFTN...THEN BECOME NW 10 TO 20 KT AND GUSTY FOR SAT
NGT THRU SUN...AS THE LO MOVES AWAY TO THE NE AND HI PRES BLDS IN
FM THE WNW. HI PRES WILL BLD INTO AND OVR THE REGION FOR LATER SUN
INTO MON.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NCZ012-013-030.
VA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VAZ092.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ060-
065>067-079-080-087-088.
MARINE...NONE.
&&
$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...TMG
MARINE...TMG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
850 AM CST FRI FEB 22 2013
.UPDATED DISCUSSION FOR INCREASED SNOW AMOUNTS...
EMBEDDED VORT MAXI WITHIN THE UPPER LEVEL LOW HAS RESULTED IN AN
AREA OF FRONTOGENESIS ALONG AND EAST OF THE MISSISSIPPI RIVER AS
IDENTIFIED BY THE RAP13 SHORT RANGE MODEL. SURFACE OBS INDICATED
VISBYS OF 1/2MI UNDER THIS BAND...SO USED THE HRRR AND RAP TRENDS
TO INCREASE SNOW AMOUNTS TODAY...AND ADD HEAVY SNOW WORDING THIS
MORNING.
.PREVIOUS DISCUSSION...
/ISSUED AT 335AM CST FRI FEB 22 2013/
THIS MORNING AND TODAY...SNOW HAS OVERTAKEN SOUTHERN MINNESOTA
AND WESTERN WISCONSIN EARLY THIS MORNING. SURFACE LOW PRESSURE
CENTER OVER NORTH CENTRAL MISSOURI THIS MORNING WILL CONTINUE
LIFTING NORTHEAST THROUGH EASTERN IOWA AND INTO CENTRAL WISCONSIN
BY THIS EVENING. THE HEAVIEST SNOW FALL ACROSS THE AREA WILL FALL
FROM NOW THROUGH MID MORNING...AND WILL MAKE FOR A SLOW COMMUTE
THIS MORNING. THE WEAKENING SURFACE LOW WILL MAINTAIN A RELATIVELY
RELAXED PRESSURE GRADIENT...MEANING THE WIND WILL WILL BE
RELATIVELY LIGHT SO BLOWING SNOW WILL NOT BE AN ISSUE TODAY.
SNOWFALL TOTALS WERE TWEAKED VERY SLIGHTLY FROM THE PREVIOUS
FORECAST...WITH 3 TO 6 INCHES STILL EXPECTED ACROSS THE SOUTHERN
THIRD OF MINNESOTA...AND INTO PARTS OF WEST CENTRAL
WISCONSIN...WITH GENERALLY 1 TO 3 INCHES TO THE NORTHWEST. THE
SNOWFALL TAPER OFF AND BECOME VERY LIGHT THIS AFTERNOON AND LINGER
INTO TONIGHT.
THE LOW PIVOTS OVER THE GREAT LAKES INTO SATURDAY. WEAK
LIFT AND RESIDUAL MOISTURE ON ITS WESTERN PERIPHERY WILL YIELD
LINGERING LIGHT SNOW FROM NORTH/EAST CENTRAL MN INTO WEST CENTRAL
WISCONSIN UNTIL MID-DAY SATURDAY. ADDITIONAL SNOWFALL AMOUNTS
DURING THAT TIME FRAME OF A DUSTING TO ONE INCH ARE POSSIBLE. TEMPERATURES
WILL REMAIN ON THE MILD SIDE...WITH SATURDAY MORNING LOWS RANGING
FROM 5 TO 15...AND HIGHS MAINLY FROM 25 TO 30 DEGREES.
SATURDAY NIGHT AND SUNDAY WILL BE THE BENIGN TIME FRAME DURING THE
FORECAST PERIOD...AS WEAK MID LEVEL RIDGING BUILDS LOCALLY AS AN
UPSTREAM TROUGH DIGS OVER THE FOUR CORNERS REGION. MODEL
SOLUTIONS CONTINUE TO EXHIBIT POOR AGREEMENT WITH RESPECT TO THE
EVOLUTION OF THIS FEATURE. THE ECMWF WAS THE PREFERRED MODEL THIS
MORNING...LARGELY DUE TO ITS CONSISTENCY. THIS FAVORS A SLIGHTLY
WEAKER SYSTEM WITH A PROLONGED LIGHTER INTENSITY SNOWFALL
EVENT...OVER THE STRONGER GFS WITH HIGHER RATES OF SNOWFALL. HAVE
MAINTAINED 30-50 POPS IN THE SUNDAY NIGHT THROUGH TUESDAY NIGHT
WINDOW...WITH 20S LINGERING ON WEDNESDAY. HAVE ALSO KEPT THE
HIGHER CHANCES IN SOUTHERN MN...IN CLOSER PROXIMITY TO THE SURFACE
TROUGH. HIGH TEMPERATURES NEXT WEEK WILL REMAIN SLIGHTLY BELOW
NORMAL...WITH HIGHS IN THE UPPER 20S TO MID 30S. CONVERSELY...MILD
LOWS IN THE MID TEENS TO LOWER 20S ARE ANTICIPATED.
&&
.AVIATION.../12Z TAF ISSUANCE/
WIDESPREAD SNOWFALL HAS SPREAD ACROSS THE REGION EARLY THIS
MORNING...IMPACTING ALL TAF SITES IN THE MPX FORECAST AREA.
HEAVIEST ACCUMULATIONS ARE EXPECTED AT EAU CLAIRE WITH THE LEAST
OCCURRING AT ALEXANDRIA. SNOW WILL CONTINUE TO FALL MOST OF THE
DAY ACROSS THE REGION...BUT SHOULD RAPIDLY TAPER THIS AFTERNOON AS
BEST FORCING IS SHUNTED OFF TO THE NORTH AND EAST. HOWEVER...THERE
IS CONCERN THAT A DEFORMATION BAND OF SNOW WILL IMPACT
AXN...RWF...AND STC THIS AFTERNOON...SO THERE MAY BE TEMPORARY
PERIODS THIS AFTERNOON WHEN VSBYS FALL BELOW THOSE CURRENTLY
ADVERTISED IN THE TAF AT THOSE SITES. DID NOT FEEL CONFIDENT ENOUGH
IN THE INTENSITY AND EXACT PLACEMENT SPATIALLY AND TEMPORALLY TO
INTRODUCE A TEMPO VSBY RESTRICTION AT THIS TIME...THIS WILL BE
MONITORED CLOSELY TODAY. WINDS ARE EXPECTED TO BE GENERALLY LIGHT
OUT OF THE NORTHEAST FOR MUCH OF THE DAY...BEFORE SHIFTING NORTH
THIS AFTERNOON...THEN NORTHWESTERLY TONIGHT AS THE SURFACE LOW
MAKES ITS WAY FROM NORTHERN MISSOURI THIS MORNING...TOWARD CENTRAL
WISCONSIN TONIGHT.
KMSP...THE HEAVIEST SNOW AT MSP IS BEHIND US AT THIS POINT...BUT
LIGHT SNOW WILL CONTINUE FOR MOST OF THE DAY. WE STILL EXPECT
ANOTHER INCH OR TWO OF ACCUMULATION AT THE AIRFIELD TODAY.
CEILINGS HAVE BEEN INCONSISTENT THIS MORNING...AND DOWNSTREAM
OBSERVATIONS SHOW A RANGE OF CEILING HEIGHTS FROM 500 FEET TO 2500
FEET. EXPECT CEILINGS TO DROP TO NEAR 1000 FEET AND SEE MINIMAL
IMPROVEMENT THROUGH THE TAF PERIOD. INITIAL NORTHEAST WIND WILL
TURN NORTHWEST BY EVENING...AND WESTERLY NEAR MIDNIGHT TONIGHT.
/OUTLOOK FOR KMSP/
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR ANOKA-
BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-FARIBAULT-
FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANDIYOHI-LE SUEUR-MARTIN-
MCLEOD-MEEKER-NICOLLET-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-
SHERBURNE-SIBLEY-STEELE-WASECA-WASHINGTON-WATONWAN-WRIGHT-
YELLOW MEDICINE.
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BARRON-
CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
LS/JRB
AREA FORECAST DISCUSSION
NWS BUFFALO NY
655 AM EST FRI FEB 22 2013
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE AREA FROM THE OHIO VALLEY THROUGH
TONIGHT...BRINGING THE CHANCE FOR A LIGHT WINTRY MIX OF
PRECIPITATION THIS AFTERNOON THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER LOW CROSSING THE NEBRASKA/IOWA BORDER EARLY THIS MORNING
WILL MOVE NORTHEAST INTO SOUTHERN WISCONSIN BY THIS EVENING...
REACHING THE UPPER PENINSULA OF MICHIGAN BY LATE TONIGHT. THE
ACCOMPANYING LOW LEVEL THETA-E RIDGE ON THE NOSE OF A 50 KNOT PLUS
SOUTHERLY LOW LEVEL JET CURRENTLY FOCUSING A BAND OF PRECIPITATION
ACROSS SOUTHERN LOWER MICHIGAN INTO CENTRAL OHIO. LATEST HRRR RUNS
SEEMS TO HAVE A DECENT HANDLE ON SPEED OF APPROACHING
PRECIPITATION WHICH SHOWS LITTLE DEVIATION FROM PREVIOUS FORECAST
TIMING...PLACING THE LEADING EDGE OF WEAKENING PRECIPITATION
SHIELD INTO SOUTHWEST NEW YORK AROUND NOON TIME. EVAPORATIONAL
COOLING AFFECTS WILL MORE THAN LIKELY RESULT IN PRECIPITATION TYPE
AS PREDOMINANTLY SNOW...ALTHOUGH PORTIONS OF THE SOUTHERN TIER
COULD POTENTIAL EXPERIENCE SUFFICIENT LOW LEVEL WARM AIR ADVECTION
FOR PRECIPITATION TO CHANGE TO SLEET/FREEZING RAIN BRIEFLY BEFORE
MID LEVEL DRY SLOT MOVES IN. THE OVERALL SYSTEM TAKING ON A SPLIT
PATTERN AS THE MAIN UPPER LEVEL SUPPORT LIFTS NORTH AND WEST OF
THE AREA INTO THE UPPER LAKES...WHILE THE PRIMARY PLUME OF DEEP
MOISTURE SLIDES OFF TO THE SOUTH AND EAST INTO THE MID ATLANTIC
STATES. THIS WILL LIKELY GREATLY LIMIT THE PRECIPITATION POTENTIAL
ACROSS WESTERN NEW YORK WITH ONLY LIGHT AMOUNTS EXPECTED...WITH
EVEN THE POTENTIAL FOR SOME AREAS NOT RECEIVING ANY MEASURABLE
PRECIPITATION AT ALL. AFTER THE DRY SLOT MOVES THROUGH THE AREA
TONIGHT...LINGERING LOW LEVEL WARM AIR ADVECTION COMBINED WITH
SATURATED LOW LEVELS MAY RESULT IN A PERIOD OF FREEZING DRIZZLE
ACROSS THE AREA BEFORE LOW LEVELS DRY OUT A BIT AND THE WARM AIR
ADVECTION DIMINISHES. EVEN AT THIS STAGE OF THE FORECAST TOO MANY
UNCERTAINTIES TO ISSUE HEADLINES...ALTHOUGH HEADLINES MAY
EVENTUALLY BE NEEDED FOR PORTIONS OF THE AREA AS THE EVENT UNFOLDS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
ON SATURDAY...THE LOW OVER THE GREAT LAKES WILL MOVE INTO SOUTHERN
ONTARIO AND WEAKEN AS THE COASTAL LOW MOVING NORTHEAST NEAR THE
CAROLINA COAST GATHERS STRENGTH OFFSHORE. THIS WILL MAINTAIN A SPLIT
IN THE PRECIP FIELD WITH MOST PRECIP NORTH AND SOUTH OF THE FORECAST
AREA...BUT INCREASING POPS OVER CENTRAL AND NORTHERN NY SATURDAY
AFTERNOON AND EVENING ASSOCIATED WITH GREAT LAKES/ONTARIO LOW`S COLD
FRONT INTERCEPTING WRAP AROUND MOISTURE FROM THE GATHERING STORM
ALONG THE COAST.
THE PRECIP TYPE WILL BE A WINTRY MIX IN THE MORNING WITH A CHANCE OF
SNOW...FREEZING RAIN AND SLEET FOR THE SOUTHERN TIER AND EASTERN
LAKE ONTARIO COUNTIES...AND PLAIN RAIN FOR THE WARMER LOWER
ELEVATIONS ALONG THE LAKE PLAINS SOUTH OF LAKE ONTARIO AND CLOSER TO
LAKE ERIE. THE PRECIP SHOULD TRANSITION TO ALL RAIN BY THE AFTERNOON
AS TEMPS CLIMB TO THE MID 30S TO LOWER 40S.
MID LEVEL MOISTURE BECOMES SCARCE FROM WEST TO EAST THROUGH THE LATE
AFTERNOON AND EVENING...AS A DRY SLOT BETWEEN THE NOW FADING LOW
OVER SOUTHERN ONTARIO AND THE COASTAL LOW SOUTH OF COASTAL NEW
ENGLAND. THERE WILL BE A LINGERING CHANCE OF LIGHT SNOW ALONG THE
CHAUTAUQUA RIDGE WITH WESTERLY WINDS PROVIDING SUFFICIENT LIFT OF
THE MARGINAL LOW LEVEL MOISTURE TO CREATE LIGHT PRECIP. CENTRAL AND
NORTHERN NY WILL HAVE CHANCE POPS FOR LIGHT SNOW AS WELL...AND THE
ENTIRE FORECAST AREA WILL EXPERIENCE LOW TEMPS IN THE LOWER TO MID
20S DURING SATURDAY NIGHT.
EXPECT CLEARING AND SUNNIER SKIES ON SUNDAY FOR WESTERN NY AND
FINGER LAKES...WITH STUBBORN CLOUDS CLINGING TO THE CHAUTAUQUA
RIDGE...AND CONTINUED CLOUDINESS AND SCATTERED LIGHT SNOW ACROSS THE
NORTH COUNTRY FROM THE NOW DEPARTING COASTAL LOW. AN INFLUX OF
COLDER AIR FROM THE WEST WILL HOLD HIGH TEMPS ON SUNDAY TO THE LOWER
TO MIDDLE 30S.
UPPER RIDGING AND SURFACE HIGH PRESSURE WILL BRING NEARLY CLEAR
SKIES FOR SUNDAY NIGHT THROUGH MUCH OF MONDAY...WITH LOWS SUNDAY
NIGHT IN THE LOWER TO MIDDLE 20S AND HIGHS ON MONDAY IN THE UPPER
30S TO LOWER 40S.
ANOTHER MID CONTINENTAL CUT OFF LOW AND ATTENDANT SURFACE LOW WILL
RECURVE TO THE NORTHEAST ACROSS THE MID MISSISSIPPI
VALLEY...SHUNTING A WARM FRONT NORTHWARD TO THE OHIO VALLEY. THIS
WILL BRING MORE CLOUDINESS TO THE REGION MONDAY NIGHT AND A CHANCE
OF LIGHT SNOW OR A RAIN/SNOW MIX TO THE WESTERN SOUTHERN TIER. 00Z
GFS IS MUCH FASTER THAN 00Z ECMWF WITH THIS PRECIP MONDAY NIGHT...
THE PREFERRED MODEL IS THE ECMWF SO WILL GO CLOSER TO EC AND SLOW
SPREAD OF PRECIP TO MAINLY THE AREA WEST OF THE GENESEE RIVER.
LOW MONDAY NIGHT WILL BE LIMITED TO THE UPPER 20S TO LOWER 30S FOR
MOST OF THE REGION WITH THE INFLUX OF CLOUD COVER...THE LOWER TO MID
20S EAST OF LAKE ONTARIO WHERE CLOUDS WILL ARRIVE LATER.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
THE EXTENDED PERIOD WILL START OFF WITH FAIR WEATHER ON MONDAY AS
THE AXIS OF STRONG SURFACE RIDGING DRIFTS EAST ACROSS NEW YORK
STATE. WITH 850 MB TEMPS LOOKING TO BE IN THE -7C TO -8C RANGE...
TEMPS SHOULD BE SEASONABLE TO SLIGHTLY ABOVE NORMAL...WITH HIGHS IN
THE 35-40 RANGE.
AFTER THAT...CONDITIONS WILL GO DOWNHILL FOR THE REST OF THE PERIOD
AS A DEEP CUTOFF LOW FORMS OVER THE CENTRAL MISSISSIPPI VALLEY...
THEN MIGRATES INTO THE GREAT LAKES REGION. MEANWHILE AT THE
SURFACE...A CORRESPONDING SURFACE LOW OVER ILLINOIS WILL SLOWLY LIFT
NORTHEAST INTO THE CENTRAL GREAT LAKES...WHILE A SECONDARY WAVE OF
LOW PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST.
WHILE THE MEDIUM RANGE MODELS AGREE ON THIS GENERAL SCENARIO...THEY
DISAGREE CONSIDERABLY ON THE TIMING OF ALL OF THIS...WITH THE 12Z
GFS MUCH FASTER WITH THE NORTHEASTWARD TRANSLATION OF THE CUTOFF AND
ASSOCIATED SURFACE LOW COMPARED TO THE MUCH SLOWER 12Z ECMWF...WITH
THE 12Z GEM GLOBAL LYING IN BETWEEN THESE TWO SOLUTIONS. THIS SORT
OF TIMING DISAGREEMENT IS TYPICAL FOR THE MODELS WHEN ATTEMPTING TO
HANDLE THE EVOLUTION OF A LARGE CUTOFF LOW THIS FAR OUT...WHICH IN
GENERAL TEND TO MOVE MORE SLOWLY THAN THE GUIDANCE SUGGESTS. WITH
THIS IN MIND...WILL TEND TO LEAN A BIT MORE TOWARD THE SLOWER ECMWF
FOR THE LATTER PORTIONS OF THE EXTENDED...THOUGH AT THE SAME TIME
WILL ALSO NOT ENTIRELY DISREGARD THE OTHER SOLUTIONS EITHER.
REGARDLESS OF THIS UNCERTAINTY IN TIMING...ALL OF THIS SHOULD
ULTIMATELY BRING INCREASED CHANCES FOR PRECIPITATION TO OUR AREA FOR
THE TUESDAY THROUGH THURSDAY PERIOD...WITH AT LEAST SOME POTENTIAL
FOR SIGNIFICANT PRECIP AMOUNTS /I.E. THOSE OF ONE INCH OR HIGHER/ AT
SOME POINT GIVEN WHAT SHOULD BE AN INFLUX OF PLENTIFUL ATLANTIC
MOISTURE ON THE EAST SIDE OF THIS SYSTEM. ACCORDINGLY...WILL
INDICATE A FAIRLY PROLONGED PERIOD OF HIGHER CHANCE TO EVEN SOME LOW
LIKELY POPS BEGINNING ON TUESDAY. IN TERMS OF PTYPE...TEMPS LOOK TO
BE RATHER MARGINAL THROUGHOUT THE MIDDLE OF NEXT WEEK...SO FOR NOW
WILL JUST INDICATE A GENERAL RAIN/SNOW MIX...WITH THE EXACT PTYPES
AT ANY GIVEN TIME DEPENDENT UPON THE POINT IN THE DIURNAL CYCLE.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
CIGS WILL CONTINUE TO IMPROVE THROUGH 15Z AS THE LOW LEVEL FLOW
TURNS SOUTHEAST ALLOWING THE INFLUX OF DRIER AIR. VFR CONDITIONS
WILL THEN PREVAIL FOR THE REST OF THE DAY. AS THE WARM FRONT MOVES
INTO THE AREA LATER THIS AFTERNOON AND INTO THE EVENING HOURS THERE
WILL LIKELY BE AT LEAST A BRIEF PERIOD OF -SN THAT WILL CHANGE OVER
TO A WINTRY MIX AS WARM AIR ALOFT MAKES ITS WAY INTO THE AREA.
HOWEVER MODEL SOUNDINGS INDICATE THE PRESENCE OF DRY AIR IN THE
MID-LEVELS THAT MAY BE CONDUCIVE TO PRECIP MAINLY FALLING AS DZ/FZDZ
AFTER 00Z ACROSS WESTERN NEW YORK AS TEMPERATURES WILL HOVER RIGHT
AROUND OR JUST ABOVE FREEZING...HOWEVER CONFIDENCE IS MEDIUM TO LOW
REGARDING THIS SCENARIO AT THIS POINT IN TIME AND FOR NOW WILL LEAVE
IT OUT OF TAFS WITH THE EXCEPTION OF KJHW WHERE CONFIDENCE IS HIGHER.
OUTLOOK...
TONIGHT AND SATURDAY...MVFR WITH A CHANCE OF MIXED
PCPN...TRANSITIONING TO A CHANCE OF RAIN.
SUNDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
MONDAY...VFR.
TUESDAY...MVFR WITH A CHANCE OF RAIN/SNOW.
&&
.MARINE...
EASTERLY WINDS WILL PICK UP TODAY AHEAD OF AN APPROACHING AREA OF
LOW PRESSURE...BRINGING INCREASING WAVE ACTION ABOVE 4 FEET ON THE
WESTERN HALF OF LAKE ONTARIO. ALTHOUGH THE BULK OF THE HIGHER WAVES
ARE EXPECTED OVER THE MIDDLE AND NORTHERN PORTIONS OF THE LAKE...
SMALL CRAFT CONDITIONS WILL LIKELY DEVELOP FOR A PERIOD LATE THIS
MORNING THROUGH THIS EVENING...WEST OF IRONDEQUOIT.
A COLD FRONT WILL THEN PUSH ACROSS THE LAKES ON SATURDAY...HOWEVER
THE PRESSURE GRADIENT ACROSS THE REGION SHOULD REMAIN RELAXED
ENOUGH THAT SMALL CRAFT ADVISORY CONDITIONS ARE NOT ANTICIPATED
THROUGH THE WEEKEND AT THIS TIME.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR LOZ042-043.
&&
$$
SYNOPSIS...TMA
NEAR TERM...TMA
SHORT TERM...WCH
LONG TERM...JJR
AVIATION...TMA
MARINE...TMA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CST FRI FEB 22 2013
.DISCUSSION...
NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE AS
THE ONGOING FORECAST FOR TODAY IS WELL SUPPORTED BY THE FULL 06
UTC GUIDANCE SUITE AND THE LATEST RAP RUNS. DRY LOW LEVEL AIR
ACROSS THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY WILL
KEEP THESE LOCATIONS SNOW FREE THE REMAINDER OF THE DAY. VERY
LIGHT SNOW/FLURRIES WILL CONTINUE ALONG AND WEST OF THE HIGHWAY 83
CORRIDOR THIS MORNING...AS WEAK ISENTROPIC LIFT SLOWLY FADES BY
EARLY AFTERNOON.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS WESTERN AND CENTRAL NORTH DAKOTA
FOR THE 12 UTC TAF CYCLE WELL NORTHWEST OF A STRONG WINTER STORM
ACROSS THE UPPER MISSISSIPPI VALLEY. WHILE AREAS OF MVFR CONDITIONS
IN SCATTERED LIGHT SNOW SHOWERS ARE POSSIBLE THIS MORNING...IMPACTS
TO THE TERMINALS IS EXPECTED TO BE NONE TO MINIMAL. WHILE
UNCERTAINTY IS HIGH...THERE IS A POTENTIAL FOR FOG TONIGHT AT
KMOT...KBIS AND KJMS AFTER 10 UTC AS SKIES CLEAR WITH LIGHT
WINDS. GIVEN THE UNCERTAINTY...ONLY REDUCED VISIBILITIES TO 5-6 SM
AND WILL LET LATER SHIFTS EVALUATE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...AYD
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
613 AM CST FRI FEB 22 2013
.SHORT TERM UPDATE...
BANDS OF LIGHT TO MODERATE SNOWFALL CONTINUE OVER THE FORECAST
AREA THIS MORNING. VISIBLITIES HAVE BEEN GENERALLY AROUND A MILE
TO A 1/2 MILE IN THE HEAVIER SNOWBANDS. OFFICIALLY 1.9 OF INCHES
OF SNOW SO FAR AT THE OFFICE AS OF 6 AM. VERY GENERALLY ABOUT 1
TO 3 INCHES SO FAR THIS MORNING OVER PARTS OF CENTRAL AND
EASTCENTRAL WISCONSIN. JUST STARTING TO GET ADDITIONAL SNOWFALL
REPORTS FROM OBSERVERS.
AM GETTING CONCERNED THAT MID-LEVEL DRYING MAY VERY WELL WORK ITS
WAY INTO THE SOUTHERN PORTION OF THE FORECAST AREA IN THE NEXT
COUPLE OF HOURS. EXTRAPOLATION OF BACK EDGE OF INITIAL PRIAMRY
SNOWBAND WOULD TAKE IT TO ABOUT AN OSHKOSH TO MARSHFIELD LINE BY
8AM...AND PERHAPS INTO THE GREEN BAY AREA BY 10 AM. THIS TREND IS
ALSO APPEARING IN THE LATEST HRRR SHORT TERM FORECAST. HRRR ALSO
CONTINUES TO INSIST THAT SOME SECONDARY WEAKER SNOWBAND
DEVELOPMENT WILL OCCUR JUST SOUTHWEST OF THE FORECAST AREA TOWARD
NOONTIME THAT IS PROJECTED TO SPREAD NORTHEAST BACK INTO THE
FORECAST AREA. GIVEN THAT THE STORM SYSTEM IS BEGINNING THE
PROCESS OF WEAKENING...SECONDARY DEVELOPMENT WILL NOT BE AS
ROBUST AS WITH A DEEPENING SYSTEM.
WILL LIKELY NEED TO MAKE SOME ADJUSTMENTS IN THE MORNING FORECAST
TO ACCOUNT FOR THESE TRENDS. OBVIOUSLY IF WE DO NOT GET ADDITIONAL
SNOWBAND DEVELOPMENT UPSTREAM IN THE NORTHEAST QUADRANT OF THE
APPROACHING UPPER-LOW THIS COULD CUT STORM SNOWFALL TOTALS.
FORECAST UPDATE WILL BE OUT HOPEFULLY BY 630 AM.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
EXPECT SOME LIGHT SNOW SHOWERS OR FLURRIES TO PERSIST ACROSS THE
NORTHERN PART OF THE FORECAST AREA ON SATURDAY NIGHT AS THE
CURRENT STORM SYSTEM CONTINUES TO MOVE AWAY FROM WISCONSIN. AFTER
THAT THERE WILL BE A PERIOD OF DRY WEATHER...THROUGH SUNDAY
NIGHT...WITH SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE OVER
THE STATE.
CONFIDENCE IS LOW REGARDING THE NEXT STORM SYSTEM EXPECTED TO
IMPACT THE AREA. THERE WERE SIGNIFICANT DIFFERENCES AMONG THE
MODELS IN THEIR HANDLING OF THE SYSTEM. THIS HAS RESULTED IN A
FORECAST OF CHANCE POPS MONDAY NIGHT THROUGH WEDNESDAY...FOR NOW.
HOPEFULLY MODELS WILL CONVERGE ON A SIMILAR SOLUTION WITHIN THE
NEXT COUPLE OF DAYS.
LOW TEMPERATURES ON SUNDAY NIGHT MAY NEED TO BE LOWERED DUE TO
FRESH SNOW AND LIGHT WINDS...BUT NOT SURE WHETHER CLOUDS WILL HANG
AROUND THE AREA SO DID NOT GO TOO COLD. OTHERWISE TEMPERATURES
SHOULD BE AT OR ABOVE NORMAL WITH MAINLY SOUTHWEST OR ZONAL UPPER
FLOW THE REST OF THE PERIOD.
&&
.AVIATION...LOOK FOR DETERIORATING CONDITIONS OVERNIGHT AS SNOW
MOVES INTO THE REGION. VISBYS EXPECTED TO DROP QUICKLY AS SNOW
MOVES IN...WITH IFR OR LIFR CONDITIONS EXPECTED THROUGH THE
MORNING HOURS. 3 TO 5 INCHES OF SNOW EXPECTED IN MOST PLACES WITH
GUSTY WINDS PRODUCING SOME BLOWING AND DRIFTING ESPECIALLY AT
SUE/MTW/GRB/ATW/OSH FRIDAY MORNING. LOOK FOR LONG DURATION/INTO
SAT/ OF LIGHT SNOW OR FLURRIES AS UPPER LEVEL LOW PRESSURE SYSTEM
LIFTS NORTH THROUGH STATE.
TE
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ005-
010>013-018>022-030-031-035>040-045-048>050-073-074.
&&
$$
ESB
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
513 PM EST FRI FEB 22 2013
.SYNOPSIS...
A LOW LEVEL WEDGE WILL REMAIN IN PLACE THROUGH SATURDAY. AN AREA
OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST TONIGHT AND MOVE
UP THE CAROLINA COAST SATURDAY....PROVIDING MORE RAIN COVERAGE
TONIGHT AND SATURDAY. HIGH PRESSURE WILL BRIEFLY BUILD IN SUNDAY.
ANOTHER WEATHER SYSTEM WILL PROVIDE RAIN LATE SUNDAY NIGHT AND
MONDAY...FOLLOWED BY CLEARING TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATE THIS AFTERNOON AND EARLY THIS EVENING...UPPER LEVEL RIDGE
AXIS HAS SHIFTED TO THE EAST COAST...WITH A MOIST SW FLOW OVER OUR
REGION. LOW LEVEL WEDGE OVER OUR FORECAST AREA...AS SURFACE HIGH
PRESSURE RIDGES DOWN THE EAST COAST. RADAR SHOWS THAT ONE AREA OF
LIGHT RAIN HAS SHIFTED TO THE EAST. LATEST 13 KM RUC RUN SHOWS
VERY WEAK SHORT WAVE OR RIPPLE IN UPPER FLOW MOVING EAST DURING
THE LATE AFTERNOON TIME PERIOD WITH LOW LEVEL MOISTURE TRANSPORT
TO THE REGION. ALSO...THE RUC13 HOURLY POPS HAVE CHANCES
INCREASING.
TONIGHT...AN UPPER DISTURBANCE WILL MOVE ACROSS OUR REGION
LEADING TO A STRONGER LOW LEVEL JET AND MORE ISENTROPIC LIFT
PRECIPITATION DEVELOPING AND MOVING INTO THE REGION...AS A LOW
PRESSURE WAVE DEVELOPS ALONG THE GULF COAST TONIGHT AND BEGINS TO
TRANSITION EASTWARD.
WITH WEDGE AND LOW CLOUDS REMAINING IN PLACE...WILL EXPECT TEMPS TO
REMAIN GENERALLY STEADY THROUGH TONIGHT. DID LOWER OVERNIGHT LOW
TEMPERATURES A BIT USING THE LAMP25 GUIDANCE AND THE MIN TEMPERATURE
SMART TOOL. CAME UP WITH MAINLY UPPER 30S NORTH TO LOWER 40S SOUTH.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
SURFACE LOW ALONG THE CAROLINA COAST WILL BE MOVING
NORTHEAST ALTHOUGH CONTINUED MOISTURE FLUX INTO THE
REGION....PRECIPITABLE WATER 2 STANDARD DEVIATIONS ABOVE NORMAL
EARLY. STRONGEST ISENTROPIC LIFT SHIFTING TO THE EAST BY AFTERNOON.
MODEL SURFACE ANALYSIS/T-SECTIONS INDICATE IN-SITU WEDGE WILL
CONTINUE THROUGH THE DAY AND EXPECT EXTENSIVE CLOUDINESS. AFTER
MORNING RAIN...SHIFTING EAST IN THE AFTERNOON...PATCHY LIGHT RAIN
AND OR DRIZZLE. CLEARING SHOULD BE DELAYED UNTIL AFTER 06Z SUNDAY
AS MID LEVEL SHORT WAVE TROUGH LIFTS NORTHEAST ACROSS THE MIDDLE
ATLANTIC AND FLOW SHIFTS FROM SOUTHWEST TO WEST. MET MAXIMUM
TEMPERATURE GUIDANCE LOOKS THE MOST REASONABLE FOR SATURDAY...MAV
WAY TOO HIGH GIVE IN-SITU WEDGE. BLEND OF LOCAL WEDGE AND MET
GUIDANCE FOR MAXIMUM TEMPERATURE...THIS IS SUPPORTED BY SREF.
COLD FRONT MOVING THROUGH SATURDAY NIGHT WITH DRYING BY SUNDAY
MORNING. DESPITE COLD ADVECTION EARLY SUNDAY...TEMPERATURES WILL
WARM TO ABOVE NORMAL VALUES DUE TO DOWNSLOPE FLOW. SURFACE RIDGE
AGAIN BUILDING INTO THE REGION FROM THE NORTH AND UPPER LEVEL FLOW
BECOMING SOUTH...WHICH WILL SET UP ANOTHER WEDGE SITUATION.
INCREASING CLOUDS AFTER MIDNIGHT WITH LIGHT RAIN POSSIBLE MAINLY
CSRA TOWARD MORNING.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
RIDGE OVER THE NORTHEASTERN STATES EXTENDING INTO THE
CAROLINAS...WEDGE COLD AIR DAMMING MONDAY. CONFIDENCE IS HIGH FOR
WIDESPREAD RAIN GIVEN DEGREE OF MOISTURE FLUX/ISENTROPIC LIFT SO
FORECAST POPS ABOVE MOS GUIDANCE. LOWERED HIGH TEMPERATURES BELOW
GUIDANCE FOR MONDAY. RAIN IS EXPECTED TO DIMINISH EARLY TUESDAY AS
SURFACE LOW MOVES TO THE NORTHEAST AND COLD ADVECTION DEVELOPS.
SEVERAL SHORT WAVES MOVING THROUGH THE REGION IN BROAD UPPER LEVEL
CYCLONIC FLOW...HOWEVER AIR MASS APPEARS DRY THROUGH THE REST OF
THE PERIOD...ALTHOUGH TEMPERATURES MORE LIKELY TO BE BELOW NORMAL.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
LOW LEVEL WEDGE IN PLACE AS HIGH PRESSURE RIDGES DOWN THE EAST COAST.
LATEST RADAR LOOPS SHOW LIGHT RAIN MOVING EAST. SO WE MAY HAVE A BREAK
IN THE RAINFALL FOR 2-3 HOURS. HOWEVER...REGIONAL RADARS SHOW MORE
RAIN IN SOUTHERN GEORGIA AND THE LATEST MODEL RUNS INDICATE THAT THIS
AREA WILL SPREAD ON INTO THE FORECAST AREA.
LATEST OBS INDICATING IFR CONDITIONS. WILL SOME LOWERING OF
VSBYS/CIGS TO LIFR AS RAIN MOVES IN TONIGHT. PRECIPITATION AND
LOW LEVEL WEDGE EXPECTED TO CONTINUE THROUGH AT LEAST MIDDAY
SATURDAY...POSSIBLY LONGER. SO NO SIGNIFICANT IMPROVEMENT IN
CIGS/VSBYS EXPECTED THROUGH AT LEAST SATURDAY MORNING.
EXTENDED AVIATION OUTLOOK...LOW CIGS AND POSSIBLY VSBYS MAY LINGER
INTO SATURDAY NIGHT...THOUGH GRADUAL IMPROVEMENT POSSIBLE. NO
IMPACTS TO AVIATION EXPECTED SUNDAY. DETERIORATING CONDITIONS
EXPECTED AGAIN LATE SUNDAY NIGHT AND MONDAY AS ANOTHER SYSTEM
PROVIDES PRECIPITATION AND WEDGE LIKE CONDITIONS. IMPROVING
CONDITIONS TUESDAY...WITH BREEZY CONDITIONS POSSIBLE. NO SIGNIFICANT
IMPACTS TO AVIATION EXPECTED WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1258 PM EST FRI FEB 22 2013
.PREV DISCUSSION...
UPDATE...
/ISSUED 1037 AM EST FRI FEB 22 2013/
BULK OF PRECIP HAS SHIFTED TO THE SOUTHEAST PART OF THE CWA AND
MAIN UPDATE TO THE FORECAST WAS DECREASE PRECIPITATION ACROSS
NORTH GEORGIA. GIVEN LOW CLOUDS...MOISTURE AND VERY LIGHT RETURNS
ON RADAR...HAVE MENTIONED DRIZZLE ACROSS NORTH GEORGIA FOR THIS
MORNING. ALTHOUGH PRECIP WILL CONTINUE ACROSS THE SOUTHEAST
PORTION OF THE CWA THROUGH THE AFTERNOON...THE HRRR HOLDS OFF ON
BRINGING BETTER RAIN CHANCES BACK INTO THE ATL METRO AREA UNTIL
LATE THIS AFTERNOON. OTHER HI RES MODELS SUGGEST A LATER TIME
FRAME WITH THE BETTER POPS BEGINNING TONIGHT FOR THE ATL AREA.
CURRENT FORECAST TRENDS TOWARD THE TIMING OF THE HRRR...BUT MAY
STILL BE ON THE EARLY SIDE.
MU CAPE THROUGH THE AFTERNOON IS AROUND 400 J/KG. WITH LIMITED
LIGHTNING STRIKES THIS MORNING...HAVE OPTED TO SHOW ISOLATED
THUNDER THROUGH 18Z AND THEN SCATTERED THUNDER FOR THE AFTERNOON
WITH THE BETTER HEATING OF THE DAY.
HAVE SEEN ONE RIVER SITE /CUMMING/ GO INTO FLOOD THIS MORNING BUT
WITH BULK OF PRECIP EXPECTED OVERNIGHT...THINK MOST HYDRO PROBLEMS
SHOULD HOLD OFF UNTIL TONIGHT.
11
SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 410 AM EST FRI FEB 22 2013/
GEORGIA REMAINS UNDER PERSISTENT SOUTHWESTERLY UPPER FLOW THROUGH
THE FORECAST. MAIN UPPER LOW/SHORT WAVE TRACK REMAINS WELL NORTH
OF THE STATE...HOWEVER RICH MOISTURE FEED...STALLED FRONTAL BOUNDARY
AND A SERIES OF WEAK TO MODERATE SHORT WAVES AND ASSOCIATED SURFACE
LOWS CONTINUE TO TRACK ACROSS THE REGION THROUGH THE SHORT TERM
FORECAST PERIOD. INSTABILITY REMAINS MARGINAL AND NO WIDESPREAD
SEVERE THUNDERSTORMS ARE EXPECTED...HOWEVER THE ACTIVITY ALONG AND
SOUTH OF THE FRONT WILL NEED TO BE WATCHED FOR THE POTENTIAL FOR
ISOLATED SEVERE WEATHER. MAIN THREAT CONTINUES TO BE THE PERSISTENT
HEAVY RAIN AND FLOODING POTENTIAL. AREA OF SHOWERS AND A FEW
THUNDERSTORMS CURRENTLY ALONG THE FRONT SINKS INTO CENTRAL GEORGIA
TAKING THE BETTER PRECIPITATION TOTALS WITH IT...BUT WIDESPREAD
LIGHT TO OCCASIONALLY MODERATE RAIN IS STILL POSSIBLE OVER THE
NORTH. RAINFALL RATES DIMINISH SOMEWHAT TODAY BUT HEAVY RAIN WILL
MOVE UP THE FRONTAL BOUNDARY AGAIN TONIGHT AND EARLY SATURDAY AS THE
NEXT WAVE SWEEPS UP THE FRONTAL BOUNDARY. STILL LOOKS LIKE A BIT OF
A BREAK IN THE ACTION SATURDAY NIGHT AS THE SHORT WAVE EXITS AND THE
FRONTAL BOUNDARY...AT LEAST TEMPORARILY... SINKS SOUTH OF THE
FORECAST AREA.
LATEST QPF REMAINS IN LINE WITH PREVIOUS TRENDS SO I DO NOT PLAN ON
ADJUSTING THE CURRENT FLOOD WATCH AT THIS TIME. CENTRAL GEORGIA HAS
THE POTENTIAL TO SEE OVER 4 INCHES OF RAIN BY EARLY SUNDAY MORNING
WITH SLIGHTLY LOWER BUT STILL SIGNIFICANT AMOUNTS OVER 2 INCHES
ALONG THE I-20/I-85 CORRIDOR.
20
LONG TERM /SUNDAY THROUGH THURSDAY/...
/ISSUED 410 AM EST FRI FEB 22 2013/
LONG TERM FORECAST REMAINS FULL OF ACTIVITY. THE FIRST SYSTEM IS
EXPECTED TO AFFECT THE CWA ON MONDAY AND POSSIBLY INTO TUESDAY. I
HAVE WORKED THREE SHIFTS ON THIS DESK HOPING THAT THE GUIDANCE
WOULD COME TO A CONSENSUS OR START CONVERGING ON A SOLUTION FOR
THIS SYSTEM. THEY HAVE NOT. THE EURO CONTINUES TO BE THE SLOWEST
OF ALL SOLUTIONS...AND IS FAVORED BY HPC. AS SUCH...DECIDED TO GO
WITH A THE EURO SOLUTION. THIS BRINGS THE WARM FRONT ACROSS THE
CWA DURING THE LATE AFTERNOON ON MONDAY. MOST OF CENTRAL GEORGIA
SHOULD BE IN THE WARM SECTOR. THE COLD FRONT IS EXPECTED TO
APPROACH THE CWA AROUND 06Z TUESDAY. DEPENDING ON HOW MUCH
MOISTURE RETURN CAN OCCUR IN THE WARM SECTOR...SBCAPES ARE
LOW...SO HAVE DECIDED TO INCLUDE A SLIGHT CHANCE FOR THUNDER. DEEP
LAYER SHEAR IS ABOUT 50 TO 80 KNOTS FROM SOUTH TO NORTH ACROSS THE
CWA...AND LOW LEVEL SHEAR LOOKS DECENT AT THIS TIME. THIS WILL
NEED TO BE WATCHED CLOSELY AS WE GET CLOSER TO THE EVENT.
THIS UPPER LEVEL LOW IS FORECAST TO CUTOFF ACROSS THE GREAT LAKES
REGION THROUGH THE REST OF THE PERIOD. COOLER AIR IS FORECAST TO
MOVE IN FROM THE NORTH AS SHORTWAVES CIRCULATE AROUND THE LOW. ONE
OF THESE SHORTWAVES COULD LEAD TO SOME PRECIP ACROSS NORTHERN
PORTIONS OF THE CWA LATER IN THE PERIOD.
ARG
&&
.AVIATION...
18Z UPDATE...
BULK OF PRECIP REMAINS SOUTH OF THE TAF SITES WITH SOME LIGHT
SHOWERS AROUND MCN. -DZ WILL CONTINUE ON AND OFF IN THE ATL AREA
THROUGH THIS AFTERNOON AND BETTER CHANCES OF -SHRA DO NOT RETURN
UNTIL 00-02Z FOR ATL. LIFR TO IFR CIGS WILL CONTINUE THROUGH SATURDAY
MORNING. ALTHOUGH ATL CIGS HAVE REACHED 400FT...COULD STILL SEE A
SLIGHT IMPROVEMENT TO 600FT AT SOME POINT THIS AFTERNOON. LARGE
DISCREPANCIES ON WIND DIRECTION SATURDAY AFTERNOON...SO CONFIDENCE
ON WIND DIRECTION IS LOW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON CIGS AND VSBYS. HIGH CONFIDENCE ON
WIND...EXCEPT LOW CONFIDENCE ON DIRECTION AFTER 12Z SATURDAY.
MEDIUM CONFIDENCE ON TIMING OF SHRA RETURNING.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 48 43 55 41 / 90 100 80 10
ATLANTA 52 46 59 39 / 80 100 80 10
BLAIRSVILLE 48 41 54 35 / 70 100 80 10
CARTERSVILLE 53 45 59 37 / 70 100 80 10
COLUMBUS 63 56 65 43 / 100 100 80 20
GAINESVILLE 49 42 54 40 / 80 100 80 10
MACON 62 54 64 43 / 100 100 90 20
ROME 55 45 60 35 / 60 90 70 10
PEACHTREE CITY 54 47 61 39 / 90 100 80 10
VIDALIA 70 58 69 51 / 100 100 80 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...BUTTS...CARROLL...
CHATTAHOOCHEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...
CRISP...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...FAYETTE...
FORSYTH...GLASCOCK...GREENE...GWINNETT...HALL...HANCOCK...
HARALSON...HARRIS...HEARD...HENRY...HOUSTON...JACKSON...JASPER...
JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...MACON...
MADISON...MARION...MERIWETHER...MONROE...MONTGOMERY...MORGAN...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...
PAULDING...PEACH...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...
SCHLEY...SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TREUTLEN...TROUP...
TWIGGS...UPSON...WALTON...WARREN...WASHINGTON...WEBSTER...
WHEELER...WILCOX...WILKES...WILKINSON.
&&
$$
SHORT TERM...20/11
LONG TERM....ARG
AVIATION...11
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
259 PM CST FRI FEB 22 2013
.SYNOPSIS...
ISSUED AT 257 PM CST FRI FEB 22 2013
SLOWLY FILLING SURFACE LOW THAT HAS MOVED NORTH ACROSS THE FORECAST
AREA TODAY IS CONTINUING TO MOVE UP INTO SOUTHERN WISCONSIN...AND AS
OF 2 PM WAS LOCATED WEST OF MADISON WISCONSIN...WITH A BROAD AREA OF
PRESSURE FALLS OVER WISCONSIN. A VERY WEAK TROUGH AXIS EXTENDS BACK
INTO NORTHERN IOWA...WHERE SNOW CONTINUES TO FALL VERY LIGHTLY. LOW
CLOUDS EXTEND BACK INTO NORTHERN MISSOURI. THERE IS AN AREA IN
NORTHWEST MISSOURI WHERE THE CLOUDS HAVE EITHER THINNED OR CLEARED
OUT ENTIRELY AS WE CAN SEE THE TEXTURE OF THE GROUND BENEATH ON
VISIBLE SATELLITE IMAGERY. THIS IS IN A OBSERVATIONAL DATA VOID
AREA...SO IT IS HARD TO DETERMINE WHAT EXACTLY IS GOING ON. AT
UPPER LEVELS...BROAD UPPER LEVEL TROUGH OVER THE WESTERN CONUS WITH
THE STRONG SHORTWAVE OVER THE MIDWEST ASSOCIATED WITH THIS STORM
SYSTEM. STRONG PRESSURE FALLS AHEAD OF THE SHORTWAVE IMPLY THAT IT
WILL CONTINUE NORTHEAST...BUT SMALL RISES BEHIND IT SHOW THAT IT IS
FILLING AND THE BROADER SCALE TROUGH IS STILL DEEPENING. ..LE..
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM CST FRI FEB 22 2013
THIS AFTERNOON THE SNOW BAND IS EXPECTED TO CONTINUE TO MOVE
NORTHEAST OUT OF THE AREA...AND PLAN ON ALLOWING THE WINTER STORM
WARNING AND ADVISORY EXPIRE HERE AT 3 PM. SOME FLURRIES WILL LIKELY
STILL AFFECT THE NORTHERN THIRD OF THE FORECAST AREA WITH SOME LOW
LEVEL CONVERGENCE AND LIFT GOING ON ACCORDING TO THE RUC THIS
EVENING. THUS...HAVE CONTINUED THE SLIGHT CHANCE POPS THIS EVENING
BUT WITH NO ACCUMULATIONS EXPECTED.
TONIGHT THE SURFACE LOW EJECTS OFF TO THE NORTHEAST...AND WILL BE
OVER THE UP OF MICHIGAN BY 06Z TONIGHT. THAT WILL DRAW THE LIFT AND
MOST OF THE MOISTURE OFF TO THE NORTHEAST...LEAVING US WITH SOME
LINGERING LOW LEVEL MOISTURE. IN FACT...ACCORDING TO SOUNDINGS WE
REMAIN FAIRLY WELL SATURATED BELOW 850MB THROUGH SATURDAY MORNING.
FLURRIES SHOULD BE POSSIBLE AS THE LEAST LITTLE WIGGLE IS GOING TO
PRODUCE THEM. IT APPEARS THAT WE WILL BE COLD ENOUGH AT THE TOP OF
THAT LAYER FOR THESE TO BE FLURRIES INSTEAD OF FREEZING DRIZZLE..BUT
LATER SHIFTS WILL HAVE TO WATCH FOR THIS. UPSTREAM MIN TEMPERATURES
FELL INTO THE TEENS OVER NEBRASKA AND KANSAS LAST NIGHT...SO HAVE
KEPT THE MIN TEMPS IN THE TEENS OVERNIGHT. MAY BE SLIGHTLY WARMER
WITH THE EXTRA CLOUD COVER...SO DID NOT BRING IN ANY SINGLE DIGIT
VALUES. THE EXTRA CLOUD COVER IS ALSO GOING TO KEEP TEMPS FROM
FALLING OFF VERY FAST OVERNIGHT...SO A SLOW DROP OFF IN THE EVENING
IS EXPECTED.
SATURDAY TO BE COLD AND QUIET WITH THE STORM OFF TO THE NORTHEAST
AND A GRADUAL CLEARING TREND FROM THE SOUTH. WE ARE NOT BRINGING IN
A COLD AIRMASS BEHIND THIS SYSTEM...BUT WITH THE SNOW COVER WE ARE
GOING TO BE COLDER THAN WE WOULD WITHOUT. SO...EXPECT HIGHS IN THE
20S TO NEAR 30. LINGERING LOW LEVEL MOISTURE SHOULD LIFT TO
AFTERNOON STRATOCUMULUS...BUT STILL ALLOWING A FAIR AMOUNT OF
SUNSHINE THROUGH. ..LE..
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 257 PM CST FRI FEB 22 2013
ANOTHER MAJOR AND STRONGER WINTER STORM FOR MONDAY/TUESDAY THE MAIN
FORECAST CHALLENGE.
OVERVIEW...INITIALIZATION GOOD TO EXCELLENT UPSTREAM INTO THE NORTH
PACIFIC. THE 18Z VERIFICATION SUPPORT ALL 4 LONGER RANGE SOLUTIONS
VERIFYING WELL AND ARE ALL SIMILAR. THATS THE GOOD NEWS...UNLESS ONE
LIKES LOTS OF SNOW...THEY ALL PUT AREA IN THE WHEELHOUSE OF A MAJOR
WINTER STORM WITH STRONG WINDS. PREFER A BLEND OF ALL 4 AS A MIX
WHICH SUPPORTS MOST OR ALL THE AREA TO PICK UP ANOTHER 4-6+ INCHES OF
SNOW WITH LOCALLY UP TO OVER 12 INCHES POSSIBLE WITH WINDS OF 20 TO
35+ MPH AND POSSIBLY HIGHER. THE CONSISTENCY OF FORCING OF UPPER JET
STRUCTURE TOOLS ALL SUGGEST IF THIS TREND CONTINUES THE NEXT 24 HOURS
THAT OUR AREA WILL SEE A MAJOR...HIGHER END WINTER STORM EVENT WITH
POSSIBLE NEAR BLIZZARD CONDITIONS. WILL UPDATE THE LOCAL HWODVN
HAZARDOUS WEATHER OUTLOOK PRODUCT FOR STRONGER AND HIGHER IMPACT
WORDING.
SATURDAY NIGHT AND SUNDAY...VERY MINOR CHANGES WITH LESS CLOUDS ARE
LIKELY SUPPORTING LOWER MINS FROM OUR SNOW-PACK AND HIGHER MAX TEMP
VALUES FROM LATE FEBRUARY SUNSHINE. LATER SHIFTS MAY NEED TO BUMP
HIGHS A FEW MORE DEGREES DUE TO THE SUNSHINE. SUNDAY NIGHT...SEE
INCREASING CLOUDS AND KEPT VERY LOW POPS FAR WEST SECTIONS OVERNIGHT
AS LEADING EDGE OF ELEVATED FORCING FOR THE NEXT MAJOR WINTER STORM
ARRIVES WITH MAIN BRUNT OF FORCING ON TAP TO IMPACT THE AREA LATER ON
MONDAY PM HOURS INTO TUESDAY.
MONDAY THROUGH NEXT WEDNESDAY...HAVE UPPED POPS MONDAY NIGHT AND
TUESDAY TO LIKELY WITH MODERATE TO HEAVY SNOW AMOUNTS SUGGESTED.
NUMEROUS TOOLS SUGGEST MOST OF THE AREA TO SEE WELL OVER 4+ INCHES
WITH MOST RELIABLE TOOLS ALL SUGGESTING A SWATH OF 6-12+ INCHES OF
HEAVY SNOW THAT RIGHT NOW IS TRENDING TOWARD A IRK-MUS-FEP LINE.
THIS SHOULD BE BETTER CLARIFIED IN THE NEXT 24 HOURS. IF PHASING
ON THE BACK SIDE OCCURS AS SUGGESTED BY SOME SOLUTIONS WITH STRONGER
OCCLUSION THEN STRONGER COLD CONVEYOR BELT SUGGESTED AND NEAR
BLIZZARD CONDITIONS LIKELY. SOME TOOLS SUGGEST WIND GUSTS OF 40-45
MPH WHICH ARE VERY CLOSE TO BLIZZARD THRESHOLD FOR LATER SHIFTS TO
MONITOR. THERE IS NO DOUBT THIS WILL BE A MAJOR EVENT LAST 12-18+
HOURS AND LIKELY GREATER THAN THE EVENT THE PAST 24 HOURS. THIS IS
A DEVELOPING SYSTEM THAT WILL STRENGTHEN VERSUS A WEAKENING AND
FILLING SYSTEM THAT PASSED. ADD WERE IN THE NATURAL BAROCLINIC
ZONE OF A PRONOUNCED SNOW AND NO SNOW LINE...THIS MAKES RISK OF A
MAJOR EVENT GREATER. THE DATA AS OF NOW...SUPPORTS AT LEAST PART
OF THE AREA WILL SEE A MAJOR WINTER STORM. AREA SNOW TO LIQUID WATER
EQUIVALENT RATIOS ARE SUGGESTED TO BE IN THE 12-15 TO 1 RANGE. ARE
TEMPERATURES SHOULD STAY IN THE MID 20S TO LOWER 30S FOR THIS EVENT.
THURSDAY AND FRIDAY...DRY WITH BELOW NORMAL TEMPERATURES AND WITH
AN EVEN GREATER THICKER AND FRESH SNOW PACK LIKELY...AREA TEMPS ARE
AGAIN PROBABLY TOO MILD. MINS COULD BE AT LEAST 5 TO 10 DEGREES TOO
MILD FOR LATER SHIFTS TO RECONSIDER. NORTHWESTERLY FLOW AND BELOW
NORMAL TEMPERATURES REMAIN APPEAR LIKELY INTO THE FIRST FEW DAYS OF
MARCH...ALL INDICATIONS ARE THIS MARCH WILL NOTHING LIKE THE
RECORD WARM MARCH OF 2012.
NICHOLS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 257 PM CST FRI FEB 22 2013
A BROAD AREA OF IFR CIGS CONTINUES OVER THE AREA WITH MAINLY VFR
VISIBILITIES. KDBQ AND SURROUNDING AREAS ARE GETTING IFR CIGS AND
VSBYS WITH SOME LINGERING LIGHT SNOW. THIS TO GRADUALLY IMPROVE IN
THE NEXT FEW HOURS TO JUST MVFR CIGS WITH VFR VSBYS. EXPECT THAT
MVFR CIGS WILL LINGER OVERNIGHT TONIGHT AND INTO SATURDAY MORNING.
PATCHES OF HIGHER CIGS MAY IMPACT KCID AND KDBQ THIS AFTERNOON AND
EARLY EVENING...BUT THESE ARE EXPECTED TO BE TEMPORARY...AND WILL
DEFINITELY FILL BACK IN AND LOWER BY 02Z. FOR NOW HAVE DECIDED TO
KEEP AN EYE ON SATELLITE AND IF LARGE ENOUGH HOLES APPEAR WILL PUT
IN A TEMPO GROUP. WINDS TO TURN WEST/SOUTHWEST THIS AFTERNOON AND
REMAIN THROUGH REMAINDER OF FORECAST AT LESS THAN 10KTS. CIGS TO
FINALLY COME TO VFR SATURDAY MORNING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...LE
SHORT TERM...LE
LONG TERM...WDN
AVIATION...LE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
131 PM CST FRI FEB 22 2013
.UPDATE...
ISSUED AT 129 PM CST FRI FEB 22 2013
HAVE DECIDED TO CANCEL A PORTION OF THE WARNING AND ADVISORY AS
SNOW HAS TAPERED OFF TO FLURRIES FOR THESE AREAS. WILL LIKELY LET
THE REMAINING PORTIONS OF THE WARNING AND ADVISORY GO AT 3 PM AS
SCHEDULED. THIS IS BASED MAINLY OFF RADAR TRENDS WITH THAT LAST
LITTLE WAVE OF SNOW MOVING THROUGH THE NORTHERN PORTIONS OF THE
AREA. HAVE ALSO UPDATED OTHER ELEMENTS...BUT WITH LITTLE CHANGE.
&&
.SHORT TERM...TODAY AND TONIGHT
/ISSUED 316 AM CST FRI FEB 22 2013/
RUNNING BEHIND DUE TO OTHER PROBLEMS. FIRST...BASED ON RAP TRENDS
WILL DROP HEADLINES FOR ROUGHLY THE SOUTHERN THIRD. THE OTHER
HEADLINES WILL CONTINUE FOR NOW BUT MAY GET CANCELLED OR MODIFIED
OVER THE NEXT 3-4 HRS.
RAP TRENDS INDICATE THE WAA WING OF SNOW WILL BE IN MN/WI SHORTLY.
FLURRIES OR VERY LIGHT SNOW IS SPORADIC ACROSS THE AREA BUT VERY
LITTLE IN THE WAY OF NEW ACCUMULATION SHOULD BE SEEN THROUGH 12Z.
DURING THE DAY THE RAP DEVELOPS NEW FORCING AS THE OCCLUDED LOW
MOVES UP THROUGH THE FAR WESTERN CWFA WHICH SHOULD INDUCE SOME NEW
LIGHT SNOW DURING THE DAY ACROSS THE AREA. CONDENSATION PRESSURE
DEFICITS WILL SLOWLY RISE SO THERE SHOULD BE A GRADUAL END TO THE
SNOW FROM SOUTH TO NORTH DURING THE DAY.
ADDITIONAL ACCUMULATIONS FOR THE REMAINDER OF THE DAY SHOULD RANGE
FROM A DUSTING TO PERHAPS AN INCH.
TONIGHT...CYCLONIC FLOW SHOULD CONTINUE TO KEEP LIGHT
SNOW/FLURRIES GOING ACROSS ROUGHLY THE NORTH/NORTHEAST THIRD OF
THE CWFA DURING THE EVENING THAT GRADUALLY ENDS DURING THE NIGHT.
BASED ON TEMPERATURES CURRENTLY IN MISSOURI...THE EASTERN CWFA
SHOULD SEE READING GET TO OR JUST ABOVE FREEZING DURING THE
DAYLIGHT HOURS. ..08..
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
/ISSUED 316 AM CST FRI FEB 22 2013/
ANOTHER ACTIVE PERIOD IS LOOMING IN THE LONG TERM...WITH ALL
MODELS SHOWING A DYNAMIC SYSTEM MONDAY THROUGH MID WEEK. THERE IS
PLENTY OF MODEL SPREAD ON TIMING AND TRACK OF THIS SYSTEM...AS
WELL AS ITS EVENTUAL EVOLUTION INTO A MAJOR LONG WAVE TROF.
THUS...FOR NOW...AND WILL FULL SUPPORT OF THIS FORECASTER...WE
WILL TAKE SOME BABY STEPS TOWARD A WINTER EVENT...OF SNOW AND
POTENTIALLY WIND. I AM ENCOURAGED THAT BOTH THE 00Z
ECMWF..UKMET...GEM...AND NAM ALL TAKE THE SYSTEM SOUTH...WITH THE
BEST TRACK FOR HEAVY QPF OVER CWAS JUST SOUTH. NOT THAT THAT WILL
OCCUR...BUT I FEEL THIS WINTER REPRESENT YET ANOTHER YEAR THAT WE
MODELS WILL EVENTUALLY TRACK SYSTEMS A BIT FARTHER NORTH THAN
THEIR DAY 3 TO 7 FORECASTS. THE GFS REMAINS MUCH FARTHER
NORTH...WEAKER...AND FASTER THAN OTHER MODELS...AND IT LARGELY
DISREGARDED EXCEPT FOR INSERTING SOME SLIGHT CHANCE POPS FOR
SUNDAY NIGHT. IN THE END...IT WOULD SEEM SLOWER IS THE WAY TO GO
ON THIS SYSTEM...ESPECIALLY SINCE IT IS ANOTHER CLOSED UPPER LOW
SYNOPTIC SYSTEM. IT TRENDS HOLD TRUE ON THE ECMWF AND OTHERS...WE
ARE CERTAIN TO NEED CATEGORICAL POPS FOR MONDAY NIGHT INTO
TUESDAY.
TEMPERATURES WILL REMAIN SOMEWHAT COOLER THAN SEASONAL NORMALS
THROUGHOUT THE FORECAST PERIOD. THUS...WITH HIGHS IN THE LOWER TO
MID 30S MUCH OF THE FORECAST...WE WILL SLOWLY LOSE SNOW COVER IN
PERIODS WE ARE NOT GAINING IT. THIS SEEMS PRETTY TYPICAL FOR LATE
FEBRUARY IN MY EXPERIENCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1203 PM CST FRI FEB 22 2013
AT THIS TIME CONDITIONS ARE MAINLY IFR...WITH VFR VISIBILITIES
FOR KMLI AND KBRL WHERE SNOW HAS ENDED. THIS TREND TO GRADUALLY
SPREAD NORTH WITH VISIBILITIES IMPROVING TO VFR FOR KCID AND KDBQ
IN THE NEXT FEW HOURS. EXPECT THAT IFR CIGS WILL LINGER OVERNIGHT
TONIGHT AND INTO SATURDAY MORNING. PATCHES OF HIGHER CIGS MAY
IMPACT KCID AND KDBQ THIS AFTERNOON...BUT THESE ARE EXPECTED TO BE
TEMPORARY...AND WILL DEFINITELY FILL BACK IN BY 00Z. FOR NOW HAVE
DECIDED TO KEEP AN EYE ON SATELLITE AND IF LARGE ENOUGH WILL PUT
IN A TEMPO GROUP. WINDS TO TURN WEST/SOUTHWEST THIS AFTERNOON AND
REMAIN THROUGH REMAINDER OF FORECAST AT LESS THAN 10KTS. CIGS TO
FINALLY COME TO VFR SATURDAY MORNING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR IAZ054.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR
IAZ040>042-051>053.
IL...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR ILZ001-
002-007.
MO...NONE.
&&
$$
UPDATE...LE
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...LE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1204 PM CST FRI FEB 22 2013
.UPDATE...
ISSUED AT 1203 PM CST FRI FEB 22 2013
HAVE BEEN SENDING SOME UPDATES THIS MORNING FOR
TEMPERATURE...WIND AND PRECIPITATION TRENDS. FORECAST IS GENERALLY
WORKING OUT REASONABLY WELL...BUT WE HAVE ONE LAST BAND OF SNOW
OVER CENTRAL IOWA RIGHT NOW THAT SHOULD ROTATE ACROSS THE
NORTHWEST PORTIONS OF THE FORECAST AREA. THOUGH THIS BAND IS
PRODUCING SOME VISIBILITIES DOWN TO A MILE...THIS SHOULD BE
TEMPORARY ENOUGH THAT DO NOT EXPECT ANY MORE THAN A DUSTING OF
ADDITIONAL ACCUMULATION. WITH THAT SAID...WILL BE EVALUATING
DROPPING SOME COUNTIES OUT OF THE WINTER STORM WARNING HERE IN THE
NEXT HOUR OR SO WHERE THE PRECIPITATION HAS ENDED. ..LE..
&&
.SHORT TERM...TODAY AND TONIGHT
/ISSUED 316 AM CST FRI FEB 22 2013/
RUNNING BEHIND DUE TO OTHER PROBLEMS. FIRST...BASED ON RAP TRENDS
WILL DROP HEADLINES FOR ROUGHLY THE SOUTHERN THIRD. THE OTHER
HEADLINES WILL CONTINUE FOR NOW BUT MAY GET CANCELLED OR MODIFIED
OVER THE NEXT 3-4 HRS.
RAP TRENDS INDICATE THE WAA WING OF SNOW WILL BE IN MN/WI SHORTLY.
FLURRIES OR VERY LIGHT SNOW IS SPORADIC ACROSS THE AREA BUT VERY
LITTLE IN THE WAY OF NEW ACCUMULATION SHOULD BE SEEN THROUGH 12Z.
DURING THE DAY THE RAP DEVELOPS NEW FORCING AS THE OCCLUDED LOW
MOVES UP THROUGH THE FAR WESTERN CWFA WHICH SHOULD INDUCE SOME NEW
LIGHT SNOW DURING THE DAY ACROSS THE AREA. CONDENSATION PRESSURE
DEFICITS WILL SLOWLY RISE SO THERE SHOULD BE A GRADUAL END TO THE
SNOW FROM SOUTH TO NORTH DURING THE DAY.
ADDITIONAL ACCUMULATIONS FOR THE REMAINDER OF THE DAY SHOULD RANGE
FROM A DUSTING TO PERHAPS AN INCH.
TONIGHT...CYCLONIC FLOW SHOULD CONTINUE TO KEEP LIGHT
SNOW/FLURRIES GOING ACROSS ROUGHLY THE NORTH/NORTHEAST THIRD OF
THE CWFA DURING THE EVENING THAT GRADUALLY ENDS DURING THE NIGHT.
BASED ON TEMPERATURES CURRENTLY IN MISSOURI...THE EASTERN CWFA
SHOULD SEE READING GET TO OR JUST ABOVE FREEZING DURING THE
DAYLIGHT HOURS. ..08..
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
/ISSUED 316 AM CST FRI FEB 22 2013/
ANOTHER ACTIVE PERIOD IS LOOMING IN THE LONG TERM...WITH ALL
MODELS SHOWING A DYNAMIC SYSTEM MONDAY THROUGH MID WEEK. THERE IS
PLENTY OF MODEL SPREAD ON TIMING AND TRACK OF THIS SYSTEM...AS
WELL AS ITS EVENTUAL EVOLUTION INTO A MAJOR LONG WAVE TROF.
THUS...FOR NOW...AND WILL FULL SUPPORT OF THIS FORECASTER...WE
WILL TAKE SOME BABY STEPS TOWARD A WINTER EVENT...OF SNOW AND
POTENTIALLY WIND. I AM ENCOURAGED THAT BOTH THE 00Z
ECMWF..UKMET...GEM...AND NAM ALL TAKE THE SYSTEM SOUTH...WITH THE
BEST TRACK FOR HEAVY QPF OVER CWAS JUST SOUTH. NOT THAT THAT WILL
OCCUR...BUT I FEEL THIS WINTER REPRESENT YET ANOTHER YEAR THAT WE
MODELS WILL EVENTUALLY TRACK SYSTEMS A BIT FARTHER NORTH THAN
THEIR DAY 3 TO 7 FORECASTS. THE GFS REMAINS MUCH FARTHER
NORTH...WEAKER...AND FASTER THAN OTHER MODELS...AND IT LARGELY
DISREGARDED EXCEPT FOR INSERTING SOME SLIGHT CHANCE POPS FOR
SUNDAY NIGHT. IN THE END...IT WOULD SEEM SLOWER IS THE WAY TO GO
ON THIS SYSTEM...ESPECIALLY SINCE IT IS ANOTHER CLOSED UPPER LOW
SYNOPTIC SYSTEM. IT TRENDS HOLD TRUE ON THE ECMWF AND OTHERS...WE
ARE CERTAIN TO NEED CATEGORICAL POPS FOR MONDAY NIGHT INTO
TUESDAY.
TEMPERATURES WILL REMAIN SOMEWHAT COOLER THAN SEASONAL NORMALS
THROUGHOUT THE FORECAST PERIOD. THUS...WITH HIGHS IN THE LOWER TO
MID 30S MUCH OF THE FORECAST...WE WILL SLOWLY LOSE SNOW COVER IN
PERIODS WE ARE NOT GAINING IT. THIS SEEMS PRETTY TYPICAL FOR LATE
FEBRUARY IN MY EXPERIENCE.
ERVIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1203 PM CST FRI FEB 22 2013
AT THIS TIME CONDITIONS ARE MAINLY IFR...WITH VFR VISIBILITIES
FOR KMLI AND KBRL WHERE SNOW HAS ENDED. THIS TREND TO GRADUALLY
SPREAD NORTH WITH VISIBILITIES IMPROVING TO VFR FOR KCID AND KDBQ
IN THE NEXT FEW HOURS. EXPECT THAT IFR CIGS WILL LINGER OVERNIGHT
TONIGHT AND INTO SATURDAY MORNING. PATCHES OF HIGHER CIGS MAY
IMPACT KCID AND KDBQ THIS AFTERNOON...BUT THESE ARE EXPECTED TO BE
TEMPORARY...AND WILL DEFINITELY FILL BACK IN BY 00Z. FOR NOW HAVE
DECIDED TO KEEP AN EYE ON SATELLITE AND IF LARGE ENOUGH WILL PUT
IN A TEMPO GROUP. WINDS TO TURN WEST/SOUTHWEST THIS AFTERNOON AND
REMAIN THROUGH REMAINDER OF FORECAST AT LESS THAN 10KTS. CIGS TO
FINALLY COME TO VFR SATURDAY MORNING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR IAZ054-
066-068.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR
IAZ040>042-051>053-063>065-067.
IL...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR ILZ001-
002-007-009-015>018-024.
MO...NONE.
&&
$$
UPDATE...LE
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...LE
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
409 PM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA TONIGHT. A WEAK
COLD FRONT WILL MOVE ACROSS THE AREA ON SATURDAY...FOLLOWED BY
BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS THE UPPER MIDWEST. AT THE SURFACE...AN OCCLUDED FRONT
EXTENDS FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A
WARM EXTENDS EASTWARD INTO NORTH-CENTRAL WV. WITH A DRY LAYER IN
PLACE ABOVE 800MB...ANY LINGERING PRECIPITATION IN WEAK LIFT AHEAD
OF THE FRONT HAS BEEN IN THE FORM OF DRIZZLE OR FREEZING DRIZZLE
ACROSS THE AREA. LOCATIONS NORTH OF PITTSBURGH AND ACROSS THE
LAUREL HIGHLANDS/ALLEGHENY FRONT REMAIN BELOW FREEZING.
TONIGHT...LOW-LEVEL MOISTURE WILL LINGER ACROSS THE AREA NORTH AND
EAST OF PITTSBURGH AS A COLD FRONT APPROACHES FROM THE WEST.
RAP/GFS/NAM SOUNDINGS CONTINUE TO INDICATE A DRY DENDRITIC
GROWTH ZONE WITH A SATURATED LAYER FROM 800MB TO THE SURFACE.
THUS...HAVE CONTINUED MENTIONING OF DZ/FZDZ FOR LOCATIONS NORTH AND
EAST OF PITTSBURGH. TEMPS WILL BE FAIRLY STEADY
OVERNIGHT...RANGING FROM THE LOWER 30S NORTH AND EAST OF
PITTSBURGH TO THE UPPER 30S IN PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
A MODEL CONSENSUS INDICATES THAT THE UPPER LOW WILL SHIFT
NORTHEASTWARD INTO THE NORTHERN GREAT LAKES AND A WEAK COLD FRONT
WILL SWING ACROSS THE OHIO VALLEY ON SATURDAY. MEANWHILE...A
SURFACE LOW WILL MOVE FROM THE SOUTHEAST INTO THE MID-
ATLANTIC...PASSING TO THE SOUTHEAST OF THE FORECAST AREA.
DESPITE MODEL AGREEMENT IN THE SYNOPTIC SCALE PATTERN...THERE
STILL LIES SOME UNCERTAINTY IN RESOLVING PRECIPITATION WITH THE
FRONTAL PASSAGE ON SATURDAY.
HAVE ONLY GONE WITH SCHC IN WESTERN PA AND CHC ACROSS THE RIDGES
ON SATURDAY AS THE WEAK FRONT MAY BE ABLE TO PRODUCE A FEW SHOWERS
WHEN IT ENCOUNTERS A BIT MORE AVAILABLE MOISTURE IN WESTERN PA AND
NORTHERN WV. OTHERWISE...WENT DRY IN OHIO. FOR PRECIP
TYPE...MOSTLY RAIN IS FORECAST AS WAA CONTINUES AHEAD OF THE FRONT.
THERE IS STILL SOME UNCERTAINTY AS TO WHETHER COLDER AIR TRAPPED
AT THE SURFACE WILL REMAIN IN PLACE NORTH OF PITTSBURGH AND ACROSS
THE RIDGES...SO HAVE THE MENTION OF SCHC OR CHC FZRA THERE. FOR
TEMPS...SIDED WITH THE WARMER MAV...WITH HIGHS RANGING FROM THE
LOWER TO MID 40S ACROSS MUCH OF THE AREA.
SATURDAY NIGHT THROUGH MONDAY...THE FRONT WILL PASS EAST OF THE
AREA SAT NIGHT WITH THE UPPER LEVEL LOW PASSING NORTH OF THE AREA
ON SUNDAY. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST
SUNDAY NIGHT INTO MONDAY. IN A CYCLONIC MID-LEVEL FLOW SAT NIGHT THAT
WILL BECOME MORE NORTHWESTERLY ON SUN...HAVE CHC POPS ACROSS THE
I-80 CORRIDOR AND WITH UPSLOPING FOR THE LAUREL
HIGHLANDS/ALLEGHENY FRONT. A DRY FORECAST IS IN PLACE SUN NIGHT
INTO MONDAY AS THE HIGH MOVES OVER THE REGION. TEMPS WILL BE A FEW
DEGREES BELOW NORMAL IN THE WAKE OF THE FRONT ON SUNDAY BEFORE
MODERATING TO 5 TO 10 DEGREES ABOVE NORMAL ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
H5 RDG AXIS WILL MOVE ACRS RGN MON NGT IN ADVC OF A STRONG CLOSED
UPR LOW OVER THE SRN PLNS. AS THE WAVE APRCHS LATE MON NGT...WARM
AIR ADVCTN WILL DVLP IN EARNEST...PROVIDING SGFNT MSTR FOR WDSPRD
PCPN. LGT PCPN XPCD TO SPREAD NEWD LATE MON NGT.
CVRG OF PCPN WILL INCR ON TUE AS THE NEGATIVELY-TILTED WAVE
CROSSES THE RGN. GIVEN CONSISTENT FCST AMONG THE MODELS AND
PERSISTENT MEXMOS PCPN SIGNAL ON TUE...CATEGORICAL POPS WERE
INCLUDED ALL ZONES ON TUE. DRY SLOT XPCD TO BRING END TO PCPN TUE
NGT.
EXACT EVOLUTION OF UPR AIR PATTERN THEREAFTER IS LESS CERTAIN...
BUT H5 TROF XPCD TO RMN OVER ERN CONUS. RESULT WILL BE PERSISTENT
COLDER AIR AND OCNL SNOW SHWRS AS WLY-NWLY LOW-LVL FLOW DOMINATES
THE RGN.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MEDIUM...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
LOW TO MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA CONTINUES TO EXIT QUICKLY WITH PATCHY DRIZZLE AND
FREEZING DRIZZLE IN ITS WAKE. BRIEF IFR WX WILL LAST AT PIT METRO
TERMINALS AND FKL/DUJ THRU 20Z. DRY SLOT THAT IS RACING NE FROM
SERN OH AND WV PER LOW LEVEL DOWNSLOPE WINDS AND SW FLOW ALOFT
REACHES ZZV - PIT - LBE THIS AFTN. BKN VFR CIGS WILL CARRY THROUGH
THE EVENING HOURS AT THE AFOREMENTIONED AIRPORTS.
HARDEST PART OF THE FORECAST IS WHAT WILL HAPPEN OVERNIGHT. ALL OF
THE STATISTICAL GUIDANCE YIELDS MVFR / IFR CIGS WHILE UPSTREAM OBS
SAY IT WILL BE VFR. PLAYED THE OPTIMISTIC ROLE FOR MOST
TERMINALS...SAVE FOR FKL/DUJ/ZZV WHERE MVFR CIGS SHOULD OCCUR FOR AT
LEAST PART OF THE NIGHT. ANY MVFR CIGS LIFT BY MID MRNG DUE TO
LIGHT SW WINDS.
WHERE TAFS COULD GO WRONG:
- MVFR CIGS COULD LINGER THROUGH THE AFTN
- MVFR/IFR CIGS MAY DEVELOP DURING THE OVERNIGHT HOURS AREA WIDE
- MVFR CIGS COULD TAKE UNTIL 15-17Z TO LIFT
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-015-016-022-023.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...WOODRUM
LONG TERM...KRAMAR
AVIATION...98
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
322 PM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA TODAY WITH A LIGHT
WINTRY MIX MOSTLY COMING TO AN END THIS AFTERNOON AND LINGERING
DRIZZLE CONTINUING INTO THE EVENING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY...FOLLOWED BY BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AN UPDATE HAS BEEN ISSUED TO CANCEL THE WINTER WEATHER ADVISORY
FOR THE PITTSBURGH METRO AND FOR ALL OF THE RIDGE ZONES EXCEPT FOR
GARRETT COUNTY. COLD AIR REMAINS DAMMED WITH FREEZING DRIZZLE
ONGOING IN GARRETT CO.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS IOWA. AT THE SURFACE...AN OCCLUDED FRONT EXTENDS
FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A WARM
EXTENDS EASTWARD ACROSS CENTRAL WV. 280-300K LAYER ISENTROPIC LIFT
IS PROVIDING FORCING FOR SCATTERED AREAS OF FREEZING RAIN NORTH OF
THE WARM FRONT THIS MORNING FOR LOCATIONS PRIMARILY NORTHEAST OF
A FRANKLIN-CLARION-INDIANA LINE.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO LIFT NORTHWARD
INTO THE UPPER OHIO VALLEY WITH THE AREA OF ISENTROPIC LIFT LIFTING
NORTHEAST OF THE AREA AND BRINGING MEASURABLE MIXED PRECIPITATION
TO AN END. MODEL SOUNDINGS INDICATE THAT DRY AIR ABOVE 800MB WILL
PREVENT ANY DENDRITIC GROWTH INTO THE AFTERNOON...WITH THE LOWER
LEVELS REMAINING SATURATED. THUS...THIS SOUNDING ALLOWS FOR A
DRIZZLE/FREEZING DRIZZLE SCENARIO.
HIGH TEMPS TODAY ARE A FEW DEGREES COOLER THAN LAMP GUIDANCE...RANGING
FROM THE LOWER 30S ACROSS THE I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT TO MID 40S IN PORTIONS OF EASTERN OHIO
AND NORTH-CENTRAL WV.
TONIGHT...LOW-LEVEL MOISTURE WILL LINGER ACROSS THE AREA NORTH AND
EAST OF PITTSBURGH AS A COLD FRONT APPROACHES FROM THE WEST.
RAP/GFS/NAM SOUNDINGS CONTINUE TO INDICATE A DRY DENDRITIC
GROWTH ZONE WITH A SATURATED LAYER FROM 800MB TO THE SURFACE.
THUS...HAVE CONTINUED MENTIONING OF DZ/FZDZ FOR LOCATIONS NORTH AND
EAST OF PITTSBURGH. TEMPS WILL BE FAIRLY STEADY
OVERNIGHT...RANGING FROM THE LOWER 30S NORTH AND EAST OF
PITTSBURGH TO THE UPPER 30S IN PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
GFS TRIES TO BRING IN PCPN WITH A DVLPG COASTAL LOW ACRS THE
RIDGES SAT. NAM/ECMWF KEEP IT FURTHER E. PREFER THE DRIER SOLNS
GIVEN SE DOWNSLOPING WNDS...AND WITH DVLPG SFC LOW CENTER SO FAR E
ALG THE COAST. WK...DRY TROF/CDFNT MOVES THRU SAT WITH COLD AIR
ADVCTN SHSN PSBL SAT NT/SUN. HI PRES RETURNS SUN NT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
H5 RDG AXIS WILL MOVE ACRS RGN MON NGT IN ADVC OF A STRONG CLOSED
UPR LOW OVER THE SRN PLNS. AS THE WAVE APRCHS LATE MON NGT...WARM
AIR ADVCTN WILL DVLP IN EARNEST...PROVIDING SGFNT MSTR FOR WDSPRD
PCPN. LGT PCPN XPCD TO SPREAD NEWD LATE MON NGT.
CVRG OF PCPN WILL INCR ON TUE AS THE NEGATIVELY-TILTED WAVE
CROSSES THE RGN. GIVEN CONSISTENT FCST AMONG THE MODELS AND
PERSISTENT MEXMOS PCPN SIGNAL ON TUE...CATEGORICAL POPS WERE
INCLUDED ALL ZONES ON TUE. DRY SLOT XPCD TO BRING END TO PCPN TUE
NGT.
EXACT EVOLUTION OF UPR AIR PATTERN THEREAFTER IS LESS CERTAIN...
BUT H5 TROF XPCD TO RMN OVER ERN CONUS. RESULT WILL BE PERSISTENT
COLDER AIR AND OCNL SNOW SHWRS AS WLY-NWLY LOW-LVL FLOW DOMINATES
THE RGN. KRAMAR
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MEDIUM...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
LOW TO MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA CONTINUES TO EXIT QUICKLY WITH PATCHY DRIZZLE AND
FREEZING DRIZZLE IN ITS WAKE. BRIEF IFR WX WILL LAST AT PIT METRO
TERMINALS AND FKL/DUJ THRU 20Z. DRY SLOT THAT IS RACING NE FROM
SERN OH AND WV PER LOW LEVEL DOWNSLOPE WINDS AND SW FLOW ALOFT
REACHES ZZV - PIT - LBE THIS AFTN. BKN VFR CIGS WILL CARRY THROUGH
THE EVENING HOURS AT THE AFOREMENTIONED AIRPORTS.
HARDEST PART OF THE FORECAST IS WHAT WILL HAPPEN OVERNIGHT. ALL OF
THE STATISTICAL GUIDANCE YIELDS MVFR / IFR CIGS WHILE UPSTREAM OBS
SAY IT WILL BE VFR. PLAYED THE OPTIMISTIC ROLE FOR MOST
TERMINALS...SAVE FOR FKL/DUJ/ZZV WHERE MVFR CIGS SHOULD OCCUR FOR AT
LEAST PART OF THE NIGHT. ANY MVFR CIGS LIFT BY MID MRNG DUE TO
LIGHT SW WINDS.
WHERE TAFS COULD GO WRONG:
- MVFR CIGS COULD LINGER THROUGH THE AFTN
- MVFR/IFR CIGS MAY DEVELOP DURING THE OVERNIGHT HOURS AREA WIDE
- MVFR CIGS COULD TAKE UNTIL 15-17Z TO LIFT
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-013>016-022-023.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
238 PM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA TODAY WITH A LIGHT
WINTRY MIX MOSTLY COMING TO AN END THIS AFTERNOON AND LINGERING
DRIZZLE CONTINUING INTO THE EVENING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY...FOLLOWED BY BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPDATE HAS BEEN ISSUED TO CANCEL THE WINTER WEATHER ADVISORY
FOR THE PITTSBURGH METRO AND FOR ALL OF THE RIDGE ZONES EXCEPT FOR
GARRETT COUNTY. COLD AIR REMAINS DAMMED WITH FREEZING DRIZZLE
ONGOING IN GARRETT CO.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS IOWA. AT THE SURFACE...AN OCCLUDED FRONT EXTENDS
FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A WARM
EXTENDS EASTWARD ACROSS CENTRAL WV. 280-300K LAYER ISENTROPIC LIFT
IS PROVIDING FORCING FOR SCATTERED AREAS OF FREEZING RAIN NORTH OF
THE WARM FRONT THIS MORNING FOR LOCATIONS PRIMARILY NORTHEAST OF
A FRANKLIN-CLARION-INDIANA LINE.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO LIFT NORTHWARD
INTO THE UPPER OHIO VALLEY WITH THE AREA OF ISENTROPIC LIFT LIFTING
NORTHEAST OF THE AREA AND BRINGING MEASURABLE MIXED PRECIPITATION
TO AN END. MODEL SOUNDINGS INDICATE THAT DRY AIR ABOVE 800MB WILL
PREVENT ANY DENDRITIC GROWTH INTO THE AFTERNOON...WITH THE LOWER
LEVELS REMAINING SATURATED. THUS...THIS SOUNDING ALLOWS FOR A
DRIZZLE/FREEZING DRIZZLE SCENARIO.
HIGH TEMPS TODAY ARE A FEW DEGREES COOLER THAN LAMP GUIDANCE...RANGING
FROM THE LOWER 30S ACROSS THE I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT TO MID 40S IN PORTIONS OF EASTERN OHIO
AND NORTH-CENTRAL WV.
TONIGHT...LOW-LEVEL MOISTURE WILL LINGER ACROSS THE AREA NORTH AND
EAST OF PITTSBURGH AS A COLD FRONT APPROACHES FROM THE WEST.
RAP/GFS/NAM SOUNDINGS CONTINUE TO INDICATE A DRY DENDRITIC
GROWTH ZONE WITH A SATURATED LAYER FROM 800MB TO THE SURFACE.
THUS...HAVE CONTINUED MENTIONING OF DZ/FZDZ FOR LOCATIONS NORTH AND
EAST OF PITTSBURGH. TEMPS WILL BE FAIRLY STEADY
OVERNIGHT...RANGING FROM THE LOWER 30S NORTH AND EAST OF
PITTSBURGH TO THE UPPER 30S IN PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GFS TRIES TO BRING IN PCPN WITH A DVLPG COASTAL LOW ACRS THE
RIDGES SAT. NAM/ECMWF KEEP IT FURTHER E. PREFER THE DRIER SOLNS
GIVEN SE DOWNSLOPING WNDS...AND WITH DVLPG SFC LOW CENTER SO FAR E
ALG THE COAST. WK...DRY TROF/CDFNT MOVES THRU SAT WITH COLD AIR
ADVCTN SHSN PSBL SAT NT/SUN. HI PRES RETURNS SUN NT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A FAIRLY ACTIVE PATTERN CONTINUES FOR THE START OF THE LONG TERM
WITH ALL OF THE MODELS HAVING ESSENTIALLY A COPY-CAT PATTERN TO
FRIDAYS SYSTEM. A DIGGING UPPER LEVEL TROUGH WILL SHIFT
NORTHEASTWARD THROUGH THE CENTRAL US...HEADING TO THE GREAT LAKES
WHILE ANOTHER LOW DEVELOPS ON THE EAST COAST. AT THIS TIME THE GFS
TENDS TO BE FASTEST WITH THE ECMWF THE SLOWEST. WITH SUCH
UNCERTAINTY IN TIMING...OPTED TO REMAIN NEAR THE GEFS MEAN AND THE
HPC GUIDANCE BUT DID TAKE INTO ACCOUNT THE HIGH MEX GUIDANCE SIGNALS
MON NGT/TUES. BEYOND TUESDAY...MODEL SOLUTIONS DIVERGE COMPLETELY SO
OPTED TO REMAIN CLOSE TO HPC GUIDANCE WITH A DEEP TROUGH KEEPING THE
WEATHER UNSETTLED THROUGH THURSDAY. TEMPERATURES WERE GENERALLY KEPT
NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MEDIUM...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
LOW TO MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA CONTINUES TO EXIT QUICKLY WITH PATCHY DRIZZLE AND
FREEZING DRIZZLE IN ITS WAKE. BRIEF IFR WX WILL LAST AT PIT METRO
TERMINALS AND FKL/DUJ THRU 20Z. DRY SLOT THAT IS RACING NE FROM
SERN OH AND WV PER LOW LEVEL DOWNSLOPE WINDS AND SW FLOW ALOFT
REACHES ZZV - PIT - LBE THIS AFTN. BKN VFR CIGS WILL CARRY THROUGH
THE EVENING HOURS AT THE AFOREMENTIONED AIRPORTS.
HARDEST PART OF THE FORECAST IS WHAT WILL HAPPEN OVERNIGHT. ALL OF
THE STATISTICAL GUIDANCE YIELDS MVFR / IFR CIGS WHILE UPSTREAM OBS
SAY IT WILL BE VFR. PLAYED THE OPTIMISTIC ROLE FOR MOST
TERMINALS...SAVE FOR FKL/DUJ/ZZV WHERE MVFR CIGS SHOULD OCCUR FOR AT
LEAST PART OF THE NIGHT. ANY MVFR CIGS LIFT BY MID MRNG DUE TO
LIGHT SW WINDS.
WHERE TAFS COULD GO WRONG:
- MVFR CIGS COULD LINGER THROUGH THE AFTN
- MVFR/IFR CIGS MAY DEVELOP DURING THE OVERNIGHT HOURS AREA WIDE
- MVFR CIGS COULD TAKE UNTIL 15-17Z TO LIFT
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-013>016-022-023.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1226 PM EST FRI FEB 22 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA TODAY WITH A LIGHT
WINTRY MIX MOSTLY COMING TO AN END THIS AFTERNOON AND LINGERING
DRIZZLE CONTINUING INTO THE EVENING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY...FOLLOWED BY BUILDING HIGH PRESSURE SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON UPDATE HAS BEEN ISSUED TO CANCEL THE WINTER
WEATHER ADVISORY FOR PORTIONS OF EASTERN OHIO...NORTHERN PANHANDLE
OF WV...AND EXTREME SOUTHWEST PA.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED 500MB LOW
CENTERED ACROSS IOWA. AT THE SURFACE...AN OCCLUDED FRONT EXTENDS
FROM THE LOW IN THE TN VALLEY. FROM THE OCCLUDED FRONT...A WARM
EXTENDS EASTWARD ACROSS CENTRAL WV. 280-300K LAYER ISENTROPIC LIFT
IS PROVIDING FORCING FOR SCATTERED AREAS OF FREEZING RAIN NORTH OF
THE WARM FRONT THIS MORNING FOR LOCATIONS PRIMARILY NORTHEAST OF
A FRANKLIN-CLARION-INDIANA LINE.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO LIFT NORTHWARD
INTO THE UPPER OHIO VALLEY WITH THE AREA OF ISENTROPIC LIFT LIFTING
NORTHEAST OF THE AREA AND BRINGING MEASURABLE MIXED PRECIPITATION
TO AN END. MODEL SOUNDINGS INDICATE THAT DRY AIR ABOVE 800MB WILL
PREVENT ANY DENDRITIC GROWTH INTO THE AFTERNOON...WITH THE LOWER
LEVELS REMAINING SATURATED. THUS...THIS SOUNDING IS FAVORABLE FOR
A DRIZZLE/FREEZING DRIZZLE SETUP. A LIGHT ICING HAS BEEN REPORTED
ACROSS MOST OF THE AREA AND HIRES MODELS SUPPORT AN ADDITIONAL FEW
HUNDREDTHS OF ICE ACCUMULATION NORTHEAST OF PITTSBURGH.
HIGH TEMPS TODAY ARE A FEW DEGREES COOLER THAN LAMP GUIDANCE...RANGING
FROM THE LOWER 30S ACROSS THE I-80 CORRIDOR AND LAUREL
HIGHLANDS/ALLEGHENY FRONT TO MID 40S IN PORTIONS OF EASTERN OHIO
AND NORTH-CENTRAL WV.
TONIGHT...LOW-LEVEL MOISTURE WILL LINGER ACROSS THE AREA NORTH AND
EAST OF PITTSBURGH AS A COLD FRONT APPROACHES FROM THE WEST.
RAP/GFS/NAM SOUNDINGS CONTINUE TO INDICATE A DRY DENDRITIC
GROWTH ZONE WITH A SATURATED LAYER FROM 800MB TO THE SURFACE.
THUS...HAVE CONTINUED MENTIONING OF DZ/FZDZ FOR LOCATIONS NORTH AND
EAST OF PITTSBURGH. TEMPS WILL BE FAIRLY STEADY
OVERNIGHT...RANGING FROM THE LOWER 30S NORTH AND EAST OF
PITTSBURGH TO THE UPPER 30S IN PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GFS TRIES TO BRING IN PCPN WITH A DVLPG COASTAL LOW ACRS THE
RIDGES SAT. NAM/ECMWF KEEP IT FURTHER E. PREFER THE DRIER SOLNS
GIVEN SE DOWNSLOPING WNDS...AND WITH DVLPG SFC LOW CENTER SO FAR E
ALG THE COAST. WK...DRY TROF/CDFNT MOVES THRU SAT WITH COLD AIR
ADVCTN SHSN PSBL SAT NT/SUN. HI PRES RETURNS SUN NT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A FAIRLY ACTIVE PATTERN CONTINUES FOR THE START OF THE LONG TERM
WITH ALL OF THE MODELS HAVING ESSENTIALLY A COPY-CAT PATTERN TO
FRIDAYS SYSTEM. A DIGGING UPPER LEVEL TROUGH WILL SHIFT
NORTHEASTWARD THROUGH THE CENTRAL US...HEADING TO THE GREAT LAKES
WHILE ANOTHER LOW DEVELOPS ON THE EAST COAST. AT THIS TIME THE GFS
TENDS TO BE FASTEST WITH THE ECMWF THE SLOWEST. WITH SUCH
UNCERTAINTY IN TIMING...OPTED TO REMAIN NEAR THE GEFS MEAN AND THE
HPC GUIDANCE BUT DID TAKE INTO ACCOUNT THE HIGH MEX GUIDANCE SIGNALS
MON NGT/TUES. BEYOND TUESDAY...MODEL SOLUTIONS DIVERGE COMPLETELY SO
OPTED TO REMAIN CLOSE TO HPC GUIDANCE WITH A DEEP TROUGH KEEPING THE
WEATHER UNSETTLED THROUGH THURSDAY. TEMPERATURES WERE GENERALLY KEPT
NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MEDIUM...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
LOW TO MEDIUM CONFIDENCE FORECAST.
AREA OF FZRA CONTINUES TO EXIT QUICKLY WITH PATCHY DRIZZLE AND
FREEZING DRIZZLE IN ITS WAKE. BRIEF IFR WX WILL LAST AT PIT METRO
TERMINALS AND FKL/DUJ THRU 20Z. DRY SLOT THAT IS RACING NE FROM
SERN OH AND WV PER LOW LEVEL DOWNSLOPE WINDS AND SW FLOW ALOFT
REACHES ZZV - PIT - LBE THIS AFTN. BKN VFR CIGS WILL CARRY THROUGH
THE EVENING HOURS AT THE AFOREMENTIONED AIRPORTS.
HARDEST PART OF THE FORECAST IS WHAT WILL HAPPEN OVERNIGHT. ALL OF
THE STATISTICAL GUIDANCE YIELDS MVFR / IFR CIGS WHILE UPSTREAM OBS
SAY IT WILL BE VFR. PLAYED THE OPTIMISTIC ROLE FOR MOST
TERMINALS...SAVE FOR FKL/DUJ/ZZV WHERE MVFR CIGS SHOULD OCCUR FOR AT
LEAST PART OF THE NIGHT. ANY MVFR CIGS LIFT BY MID MRNG DUE TO
LIGHT SW WINDS.
WHERE TAFS COULD GO WRONG:
- MVFR CIGS COULD LINGER THROUGH THE AFTN
- MVFR/IFR CIGS MAY DEVELOP DURING THE OVERNIGHT HOURS AREA WIDE
- MVFR CIGS COULD TAKE UNTIL 15-17Z TO LIFT
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
IFR WEATHER IS POSSIBLE MONDAY NIGHT INTO TUESDAY WITH THE NEXT
WEATHER SYSTEM.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ040-
041-050.
PA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ007>009-013>016-022-023-074-076.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ020-
021-029-073-075.
WV...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
WVZ023-041.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ001-
002.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...98
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1227 PM CST FRI FEB 22 2013
.UPDATED FOR 18Z AVIATION DISCUSSION...
&&
.DISCUSSION...
/ISSUED AT 850 AM CST FRI FEB 22 2013/
EMBEDDED VORT MAXI WITHIN THE UPPER LEVEL LOW HAS RESULTED IN AN
AREA OF FRONTOGENESIS ALONG AND EAST OF THE MISSISSIPPI RIVER AS
IDENTIFIED BY THE RAP13 SHORT RANGE MODEL. SURFACE OBS INDICATED
VISBYS OF 1/2MI UNDER THIS BAND...SO USED THE HRRR AND RAP TRENDS
TO INCREASE SNOW AMOUNTS TODAY...AND ADD HEAVY SNOW WORDING THIS
MORNING.
.PREVIOUS DISCUSSION...
/ISSUED AT 335AM CST FRI FEB 22 2013/
THIS MORNING AND TODAY...SNOW HAS OVERTAKEN SOUTHERN MINNESOTA
AND WESTERN WISCONSIN EARLY THIS MORNING. SURFACE LOW PRESSURE
CENTER OVER NORTH CENTRAL MISSOURI THIS MORNING WILL CONTINUE
LIFTING NORTHEAST THROUGH EASTERN IOWA AND INTO CENTRAL WISCONSIN
BY THIS EVENING. THE HEAVIEST SNOW FALL ACROSS THE AREA WILL FALL
FROM NOW THROUGH MID MORNING...AND WILL MAKE FOR A SLOW COMMUTE
THIS MORNING. THE WEAKENING SURFACE LOW WILL MAINTAIN A RELATIVELY
RELAXED PRESSURE GRADIENT...MEANING THE WIND WILL WILL BE
RELATIVELY LIGHT SO BLOWING SNOW WILL NOT BE AN ISSUE TODAY.
SNOWFALL TOTALS WERE TWEAKED VERY SLIGHTLY FROM THE PREVIOUS
FORECAST...WITH 3 TO 6 INCHES STILL EXPECTED ACROSS THE SOUTHERN
THIRD OF MINNESOTA...AND INTO PARTS OF WEST CENTRAL
WISCONSIN...WITH GENERALLY 1 TO 3 INCHES TO THE NORTHWEST. THE
SNOWFALL TAPER OFF AND BECOME VERY LIGHT THIS AFTERNOON AND LINGER
INTO TONIGHT.
THE LOW PIVOTS OVER THE GREAT LAKES INTO SATURDAY. WEAK
LIFT AND RESIDUAL MOISTURE ON ITS WESTERN PERIPHERY WILL YIELD
LINGERING LIGHT SNOW FROM NORTH/EAST CENTRAL MN INTO WEST CENTRAL
WISCONSIN UNTIL MID-DAY SATURDAY. ADDITIONAL SNOWFALL AMOUNTS
DURING THAT TIME FRAME OF A DUSTING TO ONE INCH ARE POSSIBLE. TEMPERATURES
WILL REMAIN ON THE MILD SIDE...WITH SATURDAY MORNING LOWS RANGING
FROM 5 TO 15...AND HIGHS MAINLY FROM 25 TO 30 DEGREES.
SATURDAY NIGHT AND SUNDAY WILL BE THE BENIGN TIME FRAME DURING THE
FORECAST PERIOD...AS WEAK MID LEVEL RIDGING BUILDS LOCALLY AS AN
UPSTREAM TROUGH DIGS OVER THE FOUR CORNERS REGION. MODEL
SOLUTIONS CONTINUE TO EXHIBIT POOR AGREEMENT WITH RESPECT TO THE
EVOLUTION OF THIS FEATURE. THE ECMWF WAS THE PREFERRED MODEL THIS
MORNING...LARGELY DUE TO ITS CONSISTENCY. THIS FAVORS A SLIGHTLY
WEAKER SYSTEM WITH A PROLONGED LIGHTER INTENSITY SNOWFALL
EVENT...OVER THE STRONGER GFS WITH HIGHER RATES OF SNOWFALL. HAVE
MAINTAINED 30-50 POPS IN THE SUNDAY NIGHT THROUGH TUESDAY NIGHT
WINDOW...WITH 20S LINGERING ON WEDNESDAY. HAVE ALSO KEPT THE
HIGHER CHANCES IN SOUTHERN MN...IN CLOSER PROXIMITY TO THE SURFACE
TROUGH. HIGH TEMPERATURES NEXT WEEK WILL REMAIN SLIGHTLY BELOW
NORMAL...WITH HIGHS IN THE UPPER 20S TO MID 30S. CONVERSELY...MILD
LOWS IN THE MID TEENS TO LOWER 20S ARE ANTICIPATED.
&&
.AVIATION.../18Z TAF ISSUANCE/
MVFR CEILINGS WILL PERSIST THROUGH THE FORECAST PERIOD...WITH
LIGHT SNOW SHOWERS DIMINISHING THIS AFTERNOON/EVENING. BOTH RADAR
AND SATELLITE TRENDS DEPICT SNOW BECOMING LIGHTER IN INTENSITY
AND MORE ISOLATED IN COVERAGE. FORECAST GUIDANCE SHOWS SURFACE LOW
LIFTING NORTHEAST...WITH HIGH PRESSURE BUILDING IN OVERNIGHT.
WINDS WILL BE LIGHT...AND THE LOW LEVEL MOISTURE SHOULD HANG
AROUND AS AN MVFR CLOUD DECK...WITH SOME THINNING EXPECTED ON
SATURDAY AFTERNOON.
KMSP...A FEW LIGHT SNOW SHOWERS WILL LINGER ACROSS THE REGION THIS
AFTERNOON AND COULD BRIEFLY TAKE VISBYS DOWN TO AROUND 2SM. A
LIGHTER BAND OF SNOW CURRENTLY ACROSS WESTERN MINNESOTA COULD
IMPACT KMSP THIS EVENING...BUT AT THIS TIME AGREE WITH THE
SHORT TERM GUIDANCE THAT THIS WILL FALL APART AND MOVE NORTHWARD
INTO NORTH CENTRAL MINNESOTA. TONIGHT CEILINGS SHOULD LOWER BELOW
THE CRITICAL 1700FT THRESHOLD...BUT LIFT AGAIN BY SATURDAY MID
MORNING.
/OUTLOOK FOR KMSP/
SUN...VFR/MVFR WITH -SN AND MVFR/IFR VISBY/CIGS POSSIBLE LATE.
WINDS SW AT 05KTS.
MON...MVFR WITH -SN POSSIBLE. WINDS NNE AT 05KTS.
TUE...MVFR WITH -SN POSSIBLE. WINDS N AT N AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR ANOKA-
CARVER-CHISAGO-DAKOTA-GOODHUE-HENNEPIN-ISANTI-MCLEOD-MEEKER-
RAMSEY-RICE-SCOTT-SHERBURNE-WASHINGTON-WRIGHT.
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BARRON-
CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
LS/JRB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
106 PM EST FRI FEB 22 2013
.SYNOPSIS...
DRY WEATHER IS EXPECTED ACROSS THE NORTH COUNTRY TODAY AND
TONIGHT WITH A RETURN TO MORE SEASONAL TEMPERATURES. OUR AREA
WILL BE IN BETWEEN TWO LOW PRESSURE SYSTEMS THIS WEEKEND...BUT
BOTH WILL BE CLOSE ENOUGH TO SPREAD LIGHT TO MODERATE SNOW INTO
THE REGION SATURDAY AND CONTINUE RIGHT THROUGH SUNDAY. AT THIS
TIME A GENERAL 3 TO 7 INCHES OF SNOW CAN BE EXPECTED.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1135 AM EST FRIDAY...LINGERING LOW CLOUDS CONTINUE TO
PERSIST ACROSS NORTHERN VERMONT AND FAR NORTHERN NEW YORK. FELT
THAT THE 15Z RAP HAS CAPTURED THE EXTENT OF CLOUD COVER THE BEST
AND GENERALLY FOLLOWED ITS DEPICTION OF VERY GRADUAL THINNING AND
DISSIPATION DURING THE AFTERNOON HOURS. AT THE SAME
TIME...INCREASING BUT THINNING HIGH CLOUDS CONTINUE TO PUSH INTO
CENTRAL AND WESTERN NEW YORK. THEREFORE A PARTLY-MOSTLY CLOUDY
AFTERNOON ANTICIPATED WITH THE MOST SUN IN BETWEEN THESE TWO CLOUD
CONCENTRATIONS ACROSS THE SOUTHEAST ADIRONDACKS AND
CENTRAL/SOUTHERN VERMONT. TEMPERATURES HAVE REBOUNDED NICELY FROM
THIS MORNINGS LOWS AND REMAIN ON TRACK TO REACH THE MID 30S IN
MOST LOCATIONS...WITH SOME LOWER 30S HANGING ON IN THE ADIRONDACKS
AND FAR NORTHEAST KINGDOM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 348 AM EST FRIDAY...DRY WEATHER CONTINUES TONIGHT...BUT
MORE CLOUDS RETURN ON SATURDAY AND SKIES WILL REMAIN CLOUDY RIGHT
THROUGH SUNDAY. THIS IS IN RESPONSE TO DEEPER MOISTURE MOVING
INTO THE REGION ON SOUTHWEST FLOW ALOFT. ESSENTIALLY OUR AREA
WILL BE IN BETWEEN TWO LOW PRESSURE SYSTEMS...ONE OVER THE
EASTERN GREAT LAKES ON SATURDAY AND ONE DEVELOPING OFFSHORE SOUTH
OF NEW JERSEY AND MOVES SOUTH OF CAPE COD ON SUNDAY.
HOWEVER...OUR AREA WILL BE IN AREA OF LARGE SCALE
ASCENT/DIFFLUENT FLOW SATURDAY AFTERNOON THROUGH SUNDAY AS
EASTERN GREAT LAKES UPPER LOW EVENTUALLY MOVES INTO THE AREA ON
SUNDAY. THUS LOOKING AT WIDESPREAD LIGHT SNOWS OVER A LONGER
DURATION OF TIME...WHICH WILL LEAD TO ACCUMULATING SNOWS. THERE
MAY BE SOME BRIEF PERIODS OF MODERATE SNOW...ESPECIALLY OVER
SOUTH CENTRAL VERMONT LATER SATURDAY NIGHT AND SUNDAY MORNING. AT
THIS TIME...TOTAL SNOWFALL FOR THE 48 HOUR PERIOD FROM SATURDAY
THROUGH SUNDAY LOOKS TO BE IN THE 2 TO 5 INCH RANGE ACROSS
NORTHERN NEW YORK AND 3 TO 7 INCHES ACROSS VERMONT. OF NOTE WILL
BE THE GREATER WATER CONTENT IN THE SNOW AND THUS LOOKING AT A
WETTER SNOW. THERMAL PROFILE SUGGESTS ONLY THE NEAR SURFACE WILL
GET ABOVE FREEZING...THUS THE RAIN THREAT WILL BE CONFINED TO
SATURDAY AFTERNOON AND ACROSS PARTS OF THE CHAMPLAIN AND SAINT
LAWRENCE VALLEYS. OTHERWISE LOOKING AT SNOW FOR SATURDAY NIGHT
INTO SUNDAY. HIGHS ON SATURDAY WILL BE IN THE 30S AND IN THE
LOWER TO MID 30S ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 348 AM EST FRIDAY...SNOW SHOWERS CONTINUE SUNDAY
NIGHT...ESPECIALLY IN THE MOUNTAINS...AS COASTAL LOW MOVES AWAY
FROM THE REGION AND NORTHERN STREAM LOW DRIFTS EASTWARD AS IT
WEAKENS. RIDGE OF HIGH PRESSURE WILL BUILD OVER THE NORTH COUNTRY
MONDAY AND MONDAY NIGHT. NEXT LOW PRESSURE SYSTEM TO IMPACT THE
NORTH COUNTRY APPROACHES OUR FORECAST AREA TOWARDS THE MIDDLE OF
THE WEEK. GFS CONTINUES TO BE FASTER BRINGING PRECIPITATION INTO
OUR FORECAST AREA ON TUESDAY...WHILE THE ECMWF HOLDS OFF TILL
TUESDAY NIGHT. BOTH MODELS DEPICT TWO LOW PRESSURE SYSTEMS
PHASING INTO ONE LARGE LOW PRESSURE SYSTEM...AND LINGERING OVER
THE REGION THROUGH THE END OF THE PERIOD. STILL A LOT OF
UNCERTAINTY DUE TO LACK OF MODEL- TO- MODEL AND RUN-TO-RUN
CONSISTENCY. UNFORTUNATELY HAVE CHANCE POPS MENTIONED FROM
TUESDAY THROUGH THURSDAY DUE TO TIMING DIFFERENCES OF THE GFS AND
ECMWF. HOPEFULLY MODELS WILL COME INTO BETTER AGREEMENT WITH
REGARDS TO THIS SYSTEM SOON.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...A RIDGE OF HIGH PRESSURE OVER THE REGION AT 18Z
FRIDAY WILL MOVE EAST TO THE CANADIAN MARITIMES BY 06Z SATURDAY. A WARM
FRONT WILL APPROACH THE REGION AFTER 06Z SATURDAY THROUGH 18Z SATURDAY.
SURFACE OBSERVATIONS AND VISIBLE SATELLITE LOOP SHOWING LOW CLOUDS ACROSS
THE NORTHERN PORTION OF THE FORECAST AREA AS OF 18Z FRIDAY...WITH
SOME AREAS OF MVFR CEILINGS. WIND FLOW AT THE SURFACE AND ALOFT IS LIGHT
DUE TO THE HIGH PRESSURE AREA OVER THE REGION...SO HAVE GONE WITH
A PERSISTANCE FORECAST FOR THOSE AREAS THAT ARE NOW IN THE LOW OVERCAST.
MODEL GUIDANCE SHOWING SOME LIGHT PRECIPITATION MAY BREAK OUT OVER
THE REGION AFTER 06Z SATURDAY THROUGH 18Z SATURDAY. FEEL THIS WILL
BE QUITE LIGHT AND WILL NOT CAUSE ANY RESTRICTIONS TO VISIBILITY
AT THIS TIME...SO HAVE NOT INCLUDED THIS IN THE TAF FORECASTS AT
THIS TIME.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...
18Z SATURDAY THROUGH 12Z MONDAY...AREAS OF MVFR/IFR IN LIGHT SNOW
THROUGH THE PERIOD.
VFR CONDITIONS EXPECTED FROM 12Z MONDAY THROUGH 00Z WEDNESDAY...AS
A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION.
00Z WEDNESDAY THROUGH 00Z THURSDAY...DEVELOPING IFR/MVFR IN SNOW...RAIN
AND MIXED PRECIPITATION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...MUCCILLI
SHORT TERM...EVENSON
LONG TERM...NEILES
AVIATION...WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1142 AM EST FRI FEB 22 2013
.SYNOPSIS...
DRY WEATHER IS EXPECTED ACROSS THE NORTH COUNTRY TODAY AND
TONIGHT WITH A RETURN TO MORE SEASONAL TEMPERATURES. OUR AREA
WILL BE IN BETWEEN TWO LOW PRESSURE SYSTEMS THIS WEEKEND...BUT
BOTH WILL BE CLOSE ENOUGH TO SPREAD LIGHT TO MODERATE SNOW INTO
THE REGION SATURDAY AND CONTINUE RIGHT THROUGH SUNDAY. AT THIS
TIME A GENERAL 3 TO 7 INCHES OF SNOW CAN BE EXPECTED.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1135 AM EST FRIDAY...LINGERING LOW CLOUDS CONTINUE TO
PERSIST ACROSS NORTHERN VERMONT AND FAR NORTHERN NEW YORK. FELT
THAT THE 15Z RAP HAS CAPTURED THE EXTENT OF CLOUD COVER THE BEST
AND GENERALLY FOLLOWED ITS DEPICTION OF VERY GRADUAL THINNING AND
DISSIPATION DURING THE AFTERNOON HOURS. AT THE SAME
TIME...INCREASING BUT THINNING HIGH CLOUDS CONTINUE TO PUSH INTO
CENTRAL AND WESTERN NEW YORK. THEREFORE A PARTLY-MOSTLY CLOUDY
AFTERNOON ANTICIPATED WITH THE MOST SUN IN BETWEEN THESE TWO CLOUD
CONCENTRATIONS ACROSS THE SOUTHEAST ADIRONDACKS AND
CENTRAL/SOUTHERN VERMONT. TEMPERATURES HAVE REBOUNDED NICELY FROM
THIS MORNINGS LOWS AND REMAIN ON TRACK TO REACH THE MID 30S IN
MOST LOCATIONS...WITH SOME LOWER 30S HANGING ON IN THE ADIRONDACKS
AND FAR NORTHEAST KINGDOM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 348 AM EST FRIDAY...DRY WEATHER CONTINUES TONIGHT...BUT
MORE CLOUDS RETURN ON SATURDAY AND SKIES WILL REMAIN CLOUDY RIGHT
THROUGH SUNDAY. THIS IS IN RESPONSE TO DEEPER MOISTURE MOVING
INTO THE REGION ON SOUTHWEST FLOW ALOFT. ESSENTIALLY OUR AREA
WILL BE IN BETWEEN TWO LOW PRESSURE SYSTEMS...ONE OVER THE
EASTERN GREAT LAKES ON SATURDAY AND ONE DEVELOPING OFFSHORE SOUTH
OF NEW JERSEY AND MOVES SOUTH OF CAPE COD ON SUNDAY.
HOWEVER...OUR AREA WILL BE IN AREA OF LARGE SCALE
ASCENT/DIFFLUENT FLOW SATURDAY AFTERNOON THROUGH SUNDAY AS
EASTERN GREAT LAKES UPPER LOW EVENTUALLY MOVES INTO THE AREA ON
SUNDAY. THUS LOOKING AT WIDESPREAD LIGHT SNOWS OVER A LONGER
DURATION OF TIME...WHICH WILL LEAD TO ACCUMULATING SNOWS. THERE
MAY BE SOME BRIEF PERIODS OF MODERATE SNOW...ESPECIALLY OVER
SOUTH CENTRAL VERMONT LATER SATURDAY NIGHT AND SUNDAY MORNING. AT
THIS TIME...TOTAL SNOWFALL FOR THE 48 HOUR PERIOD FROM SATURDAY
THROUGH SUNDAY LOOKS TO BE IN THE 2 TO 5 INCH RANGE ACROSS
NORTHERN NEW YORK AND 3 TO 7 INCHES ACROSS VERMONT. OF NOTE WILL
BE THE GREATER WATER CONTENT IN THE SNOW AND THUS LOOKING AT A
WETTER SNOW. THERMAL PROFILE SUGGESTS ONLY THE NEAR SURFACE WILL
GET ABOVE FREEZING...THUS THE RAIN THREAT WILL BE CONFINED TO
SATURDAY AFTERNOON AND ACROSS PARTS OF THE CHAMPLAIN AND SAINT
LAWRENCE VALLEYS. OTHERWISE LOOKING AT SNOW FOR SATURDAY NIGHT
INTO SUNDAY. HIGHS ON SATURDAY WILL BE IN THE 30S AND IN THE
LOWER TO MID 30S ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 348 AM EST FRIDAY...SNOW SHOWERS CONTINUE SUNDAY
NIGHT...ESPECIALLY IN THE MOUNTAINS...AS COASTAL LOW MOVES AWAY
FROM THE REGION AND NORTHERN STREAM LOW DRIFTS EASTWARD AS IT
WEAKENS. RIDGE OF HIGH PRESSURE WILL BUILD OVER THE NORTH COUNTRY
MONDAY AND MONDAY NIGHT. NEXT LOW PRESSURE SYSTEM TO IMPACT THE
NORTH COUNTRY APPROACHES OUR FORECAST AREA TOWARDS THE MIDDLE OF
THE WEEK. GFS CONTINUES TO BE FASTER BRINGING PRECIPITATION INTO
OUR FORECAST AREA ON TUESDAY...WHILE THE ECMWF HOLDS OFF TILL
TUESDAY NIGHT. BOTH MODELS DEPICT TWO LOW PRESSURE SYSTEMS
PHASING INTO ONE LARGE LOW PRESSURE SYSTEM...AND LINGERING OVER
THE REGION THROUGH THE END OF THE PERIOD. STILL A LOT OF
UNCERTAINTY DUE TO LACK OF MODEL- TO- MODEL AND RUN-TO-RUN
CONSISTENCY. UNFORTUNATELY HAVE CHANCE POPS MENTIONED FROM
TUESDAY THROUGH THURSDAY DUE TO TIMING DIFFERENCES OF THE GFS AND
ECMWF. HOPEFULLY MODELS WILL COME INTO BETTER AGREEMENT WITH
REGARDS TO THIS SYSTEM SOON.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 12Z SATURDAY...CONDITIONS IMPROVE THROUGH THE DAY WITH
JUST SCT CLOUDS AFTER 14Z AS HIGH PRESSURE MOVES ACROSS THE
REGION. WINDS LESS THAN 10 KTS THROUGH THE PERIOD. WINDS PICK UP
OUT OF THE SOUTHEAST SATURDAY MORNING AND CLOUDS WILL INCREASE
AND LOWER AFTER 06Z.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY... SATURDAY THERE WILL BE
SOME SNOW SHOWERS WITH MVFR CONDITIONS AT TIMES. STEADIER SNOW
WITH PERIODS OF IFR EXPECTED SATURDAY NIGHT/SUNDAY. MONDAY WILL
SEE A RETURN TO HIGH PRESSURE AND VFR CONDITIONS. TUESDAY WILL
HAVE INCREASING CLOUDS WITH SNOW/RAIN POSSIBLE ALONG WITH MVFR/IFR
CONDITIONS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...MUCCILLI
SHORT TERM...EVENSON
LONG TERM...NEILES
AVIATION...NEILES
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1102 AM PST Fri Feb 22 2013
.SYNOPSIS...A strong and wet storm system will plow into the
Pacific Northwest today and tonight. This will result in windy
conditions and heavy snow in the mountains. Mountain snow showers
will likely linger into Saturday afternoon. A very short break in
the active weather is possible early Sunday, before another
frontal system brings increasing chances for rain and snow to the
region on Monday. This active late winter weather pattern will
continue through the next week.
&&
.DISCUSSION...
Morning update: The forecast from overnight is generally on track.
This update was mainly to tweak the POPs and snow amounts for this
afternoon into tonight. The HRRR model did not resolve the warm
front that moved through this morning, but does seem to be doing a
mush better job with the cold front pushing into the Pac NW this
morning. Area web cams this morning did show some light
accumulations across the Spokane Area, in Pullman and in the
valleys of the Idaho Panhandle and in the Northeast Mountains.
This initial band has shifted into the Idaho Panhandle with
increasing isentropic ascent and moisture pushing in behind the
warm front. Surface pressure gradients will increase as the cold
front pushes onshore. This will result in increasing southerly to
southeasterly winds and warm air advection. Winds at Spokane
International have already began to pick up to around 15 mph with
gusts up to around 25 mph. These winds are beginning to move into
Okanogan Valley and up into the valleys of the Northeast Mountains
and into the ID Panhandle, including up the Purcell Trench.
Surface temperatures have risen just above freezing across these
valley locations. Dew point temperatures are hovering right at or
just below freezing, so we will likely still see some snow for
places like Spokane, Pullman, Coeur d`Alene, Sandpoint and
Colville for a few more hours. However, the warm temperatures will
result in snow melting as it hits the surface and I don`t expect
much in the way of any impacts due to snow through the rest of
this morning into this evening.
Strong westerly flow will create a rain shadow just east of the
Cascades for locations like Moses Lake, Wenatchee and into Omak.
Radar shows some returns over these areas, so a few hundreds of an
inch will be possible. Chances for precipitation will decrease for
these areas after about 1 PM with the focus of the precip over the
eastern half of the forecast area, except for right along the
Cascade crest. The cold front is expected to push across the
region this evening and drier air behind the front will result in
precip shutting off across the basin into the Spokane Area through
this period. Snow amounts did not change much across the
mountains; although the Northeast Mountains may have a hard time
reaching warming criteria. I do not anticipate making any changes
to our winter weather highlights at this time even with the
slightly less accumulations in the Northeast Mountains.
We may need to consider issuing some wind highlights with 850 mb
winds up around 40 to 50 knots across the Columbia Basin into the
Palouse and into the Northeast Blue Mountains. The question will
be if we see enough mixing for these stronger winds to reach the
surface. In the warm sector of this system through this afternoon,
I do not anticipate enough mixing for an advisory. However, with
the passage of the cold front this evening, we will see a better
potential for some stronger winds mixing down to the surface. High
resolution models indicate the strongest winds and best
possibility for advisory criteria wind speeds to develop into the
Palouse and along the foothills of the Northeast Blue Mountains.
No wind highlights will be issued at this time, but will
reconsider with the afternoon package. /SVH
&&
.AVIATION...
18Z TAFS: Local radar shows the warm front moving through my
eastern zones at 0930 and will continue to push east through the
remainder of the morning. Low clouds and moderate snow will result
in mountain obscurations the remainder of the afternoon. Further
west Rain and snow showers will continue to form and push east
across the basin and into the eastern highlands through the
afternoon resulting in varying conditions. A cold front will
approach from the west with fropa at KEAT between 23z-01z and
KGEG between 03z-06z. All TAF sites will see a 2-3 hour period of
heavier precipitation and mainly as rain. Conditions are expected
to dry out behind the front. Expect increasing pre-frontal winds
out of the south-southwest through the afternoon with peak winds
with and just behind fropa this afternoon and evening. Sustained
winds of 15-20kts with gusts 25-30kts will be likely at all TAF
sites through at least 12z. /Tobin
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 39 29 40 26 37 29 / 100 60 20 10 20 40
Coeur d`Alene 39 30 38 27 37 29 / 100 100 30 10 20 40
Pullman 43 32 39 27 39 30 / 100 100 50 20 30 30
Lewiston 51 35 48 31 45 34 / 40 50 50 20 10 20
Colville 40 27 41 24 39 25 / 100 30 20 10 20 40
Sandpoint 39 29 38 25 34 28 / 100 100 50 10 30 50
Kellogg 36 29 37 26 35 28 / 100 100 80 30 30 50
Moses Lake 50 31 49 28 46 31 / 60 10 10 0 10 20
Wenatchee 45 30 46 28 43 32 / 70 40 10 0 10 20
Omak 39 23 41 19 35 26 / 60 10 10 10 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 7 PM PST Saturday for Central
Panhandle Mountains.
Winter Weather Advisory until 10 AM PST Saturday for Lewis and
Southern Nez Perce Counties.
Winter Storm Warning until 4 AM PST Saturday for Northern
Panhandle.
WA...Winter Storm Warning until 4 AM PST Saturday for Northeast
Mountains.
Winter Weather Advisory until 10 AM PST Saturday for East Slopes
Northern Cascades.
Winter Storm Warning until 7 PM PST Saturday for Northeast Blue
Mountains.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 PM CST FRI FEB 22 2013
.SHORT TERM...TONIGHT THROUGH MONDAY
318 PM CST FRI FEB 22 2013
FORECAST CONCERNS REMAIN ON HOW LONG THE LIGHT SNOW WILL LINGER
ACROSS NORTH CENTRAL WISCONSIN THIS EVENING AND SNOW CHANCES LATE
TONIGHT THROUGH SATURDAY. FOCUS THEN TURNS TO THE LOW PRESSURE
SYSTEM TRACKING ACROSS THE CENTRAL PLAINS SUNDAY NIGHT AND
POSSIBLY LIFTING NORTHEAST AND IMPACTING THE UPPER MISSISSIPPI
RIVER VALLEY.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS PLACED A CLOSED
500 MB LOW CENTERED OVER EXTREME SOUTHEAST MINNESOTA/WEST CENTRAL
WISCONSIN...MOVING NORTHEAST. THIS LOW IS RESPONSIBLE FOR PRODUCING
2 TO 10 INCHES OF SNOWFALL ACROSS THE FORECAST AREA FROM LATE
THURSDAY NIGHT THROUGH THE DAY TODAY.
LIGHT SNOW WILL CONTINUE OVER NORTH CENTRAL WISCONSIN EARLY THIS
EVENING BEFORE TAPERING OFF. ANY LINGERING SNOW ACROSS THE REST OF
THE FORECAST AREA SHOULD TAPER OFF TO VERY LIGHT SNOW OR FLURRIES
DURING THE OVERNIGHT HOURS. THE LOW IS EXPECTED TO MOVE INTO
NORTHEAST WISCONSIN LATE TONIGHT AND EVENTUALLY INTO EASTERN UPPER
MICHIGAN DURING THE DAY ON SATURDAY. CYCLONIC FLOW OVER THE FORECAST
AREA ON THE BACK SIDE OF THE DEPARTING LOW WILL BRINGING CONTINUED
CHANCES FOR LIGHT SNOW OR FLURRIES ACROSS MUCH OF THE FORECAST AREA
THROUGH SATURDAY MORNING. CHANCES FOR LIGHT SNOW WILL SHIFT
NORTHEAST EAST MAINLY TO ALONG AND NORTHEAST OF THE INTERSTATE 94
CORRIDOR SATURDAY AFTERNOON. LOCATIONS ACROSS NORTH CENTRAL
WISCONSIN COULD RECEIVE AROUND AN INCH OF SNOWFALL BEFORE THIS
ACTIVITY EXITS THE AREA SATURDAY NIGHT. HIGH PRESSURE IS EXPECTED
TO BUILD INTO THE FORECAST AREA LATE SATURDAY NIGHT INTO SUNDAY
PROVIDING QUIET WEATHER. PLAN ON PARTLY SUNNY SKIES ON SUNDAY WITH
THE HIGH IN CONTROL. LOOK FOR HIGHS ON SATURDAY TO RANGE FROM THE
MID TO UPPER 20S OVER SOUTHEAST MINNESOTA INTO NORTH CENTRAL WISCONSIN
TO AROUND 30 OVER FAR SOUTHWEST WISCONSIN. LOWS SATURDAY NIGHT ARE
EXPECTED TO RANGE FROM THE LOWER TEENS OVER NORTHEAST IOWA TO THE
SINGLE DIGITS ABOVE ZERO OVER NORTH CENTRAL WISCONSIN. HIGHS ON
SUNDAY WILL BE NEAR NORMAL...WITH HIGHS IN THE UPPER 20 TO LOWER
30S.
A VIGOROUS TROUGH WILL MOVE OUT OF THE CENTRAL ROCKIES AND FOUR
CORNERS REGION AND INTO THE CENTRAL PLAINS SUNDAY NIGHT INTO MONDAY.
22.12 FORECAST MODELS ARE IN REASONABLE AGREEMENT ON MONDAY SHOWING
THE TROUGH ADVANCING EAST INTO THE CENTRAL PLAINS AND DEEPENING INTO
A STRONG UPPER LOW. SOLUTIONS START TO DIVERGE SLIGHTLY LEADING INTO
MONDAY NIGHT ON THE EXACT TRACK THIS SYSTEM WILL FOLLOW. THE TROUGH
COULD JUST EDGE INTO LOCATIONS ALONG AND WEST OF THE MISSISSIPPI
RIVER LATE ON MONDAY SO WILL MAINTAIN CHANCES FOR LIGHT SNOW ACROSS
THESE AREAS.
.LONG TERM...MONDAY NIGHT THROUGH THURSDAY
318 PM CST FRI FEB 22 2013
22.12 MEDIUM RANGE MODELS IN SLIGHTLY BETTER AGREEMENT TODAY
REGARDING THE TRACK OF THE STRONG UPPER LOW MONDAY NIGHT INTO
TUESDAY. THE GFS AND ECMWF BRINGING ACCUMULATING SNOW TO THE
FORECAST AREA WHILE THE GEM TAKES THE LOW WELL SOUTH OF THE FORECAST
AREA. THE GFS AND ECMWF TAKE THE LOW ACROSS CENTRAL ILLINOIS ON
TUESDAY AND INTO LOWER MICHIGAN TUESDAY NIGHT. THE GEM TAKES THE LOW
UP THE OHIO RIVER VALLEY. MEANWHILE...THE NAM OFFERS A VERY SIMILAR
SOLUTION TO THE GEM. UNCERTAINTY REMAINS ON THE TRACK OF THE STORM.
DECIDED TO LEAN TOWARD THE ECMWF AND GFS SINCE THE ECMWF TENDS TO
HAVE A BETTER TRACK RECORD WITH THE SYSTEMS FURTHER OUT IT IN
TIME...INCREASING PRECIPITATION CHANCES ACROSS NORTHEAST IOWA INTO
SOUTHWEST AND CENTRAL WISCONSIN. WILL HAVE TO MAINTAIN A CLOSE WATCH
ON THIS SYSTEM SINCE IT HAS THE POTENTIAL TO PRODUCE SIGNIFICANT
SNOWFALL. CHANCES FOR LIGHT SNOW ARE EXPECTED TO LINGER WEDNESDAY
INTO THURSDAY AS THE LOW PUSHES INTO THE EASTERN GREAT LAKES AND
STALLS.
&&
.AVIATION...THROUGH 18Z SATURDAY
1211 PM CST FRI FEB 22 2013
TRICKY AVIATION FORECAST WITH SEVERAL DIFFERENT WEATHER CONDITIONS
TO TEND WITH. SURFACE LOW WILL DRIFT TO THE EAST THIS
AFTERNOON...WITH UPPER LEVEL FEATURE MOVING NEARLY OVERHEAD. THIS
KEEPS CYCLONIC FLOW OVER KRST/KLSE THROUGH AT LEAST SATURDAY. AT
KLSE...LIGHT SNOW WILL PERSIST THROUGH EARLY AFTERNOON THEN
CONDITIONS WILL GRADUALLY IMPROVE WITH MVFR CEILINGS PREVAILING.
AT KRST...SNOW IS FINISHED MINUS INTERMITTENT SNOW SHOWERS THIS
AFTERNOON.
BREAKS AND THINNING OF THE CLOUDS THIS AFTERNOON ALONG WITH THE
FRESH 5 TO 7 INCHES OF SNOW WILL LEAD TO A FILLING OF THE CLOUD
DECK. RADIATIONAL COOLING TONIGHT AND LOW-LEVEL MOISTURE PROFILES
SUGGESTS CONFIDENCE IS PRETTY HIGH THAT THIS WILL HAPPEN...BUT
WHETHER IT COMES IN AS IFR OR MVFR IS UNCERTAIN. MODEL GUIDANCE
VARIES CONSIDERABLY...AND FOR NOW HAVE TRENDED CEILINGS AND
VISIBILITIES BACK DOWN TO LOW-END MVFR BY MID EVENING. THIS WILL
NEED TO BE CLOSELY WATCHED AND THERE IS THE CHANCE FOR A PERIOD OF
IFR CONDITIONS BEGINNING LATE TONIGHT.
FOR SATURDAY THE AREA REMAINS UNDER CYCLONIC FLOW WITH FLURRIES OR
OCCASIONAL LIGHT SNOW POSSIBLE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
318 PM CST FRI FEB 22 2013
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ017-
029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1205 PM CST FRI FEB 22 2013
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM UPDATE...
BANDS OF LIGHT TO MODERATE SNOWFALL CONTINUE OVER THE FORECAST
AREA THIS MORNING. VISIBLITIES HAVE BEEN GENERALLY AROUND A MILE
TO A 1/2 MILE IN THE HEAVIER SNOWBANDS. OFFICIALLY 1.9 OF INCHES
OF SNOW SO FAR AT THE OFFICE AS OF 6 AM. VERY GENERALLY ABOUT 1
TO 3 INCHES SO FAR THIS MORNING OVER PARTS OF CENTRAL AND
EASTCENTRAL WISCONSIN. JUST STARTING TO GET ADDITIONAL SNOWFALL
REPORTS FROM OBSERVERS.
AM GETTING CONCERNED THAT MID-LEVEL DRYING MAY VERY WELL WORK ITS
WAY INTO THE SOUTHERN PORTION OF THE FORECAST AREA IN THE NEXT
COUPLE OF HOURS. EXTRAPOLATION OF BACK EDGE OF INITIAL PRIAMRY
SNOWBAND WOULD TAKE IT TO ABOUT AN OSHKOSH TO MARSHFIELD LINE BY
8AM...AND PERHAPS INTO THE GREEN BAY AREA BY 10 AM. THIS TREND IS
ALSO APPEARING IN THE LATEST HRRR SHORT TERM FORECAST. HRRR ALSO
CONTINUES TO INSIST THAT SOME SECONDARY WEAKER SNOWBAND
DEVELOPMENT WILL OCCUR JUST SOUTHWEST OF THE FORECAST AREA TOWARD
NOONTIME THAT IS PROJECTED TO SPREAD NORTHEAST BACK INTO THE
FORECAST AREA. GIVEN THAT THE STORM SYSTEM IS BEGINNING THE
PROCESS OF WEAKENING...SECONDARY DEVELOPMENT WILL NOT BE AS
ROBUST AS WITH A DEEPENING SYSTEM.
WILL LIKELY NEED TO MAKE SOME ADJUSTMENTS IN THE MORNING FORECAST
TO ACCOUNT FOR THESE TRENDS. OBVIOUSLY IF WE DO NOT GET ADDITIONAL
SNOWBAND DEVELOPMENT UPSTREAM IN THE NORTHEAST QUADRANT OF THE
APPROACHING UPPER-LOW THIS COULD CUT STORM SNOWFALL TOTALS.
FORECAST UPDATE WILL BE OUT HOPEFULLY BY 630 AM.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
EXPECT SOME LIGHT SNOW SHOWERS OR FLURRIES TO PERSIST ACROSS THE
NORTHERN PART OF THE FORECAST AREA ON SATURDAY NIGHT AS THE
CURRENT STORM SYSTEM CONTINUES TO MOVE AWAY FROM WISCONSIN. AFTER
THAT THERE WILL BE A PERIOD OF DRY WEATHER...THROUGH SUNDAY
NIGHT...WITH SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE OVER
THE STATE.
CONFIDENCE IS LOW REGARDING THE NEXT STORM SYSTEM EXPECTED TO
IMPACT THE AREA. THERE WERE SIGNIFICANT DIFFERENCES AMONG THE
MODELS IN THEIR HANDLING OF THE SYSTEM. THIS HAS RESULTED IN A
FORECAST OF CHANCE POPS MONDAY NIGHT THROUGH WEDNESDAY...FOR NOW.
HOPEFULLY MODELS WILL CONVERGE ON A SIMILAR SOLUTION WITHIN THE
NEXT COUPLE OF DAYS.
LOW TEMPERATURES ON SUNDAY NIGHT MAY NEED TO BE LOWERED DUE TO
FRESH SNOW AND LIGHT WINDS...BUT NOT SURE WHETHER CLOUDS WILL HANG
AROUND THE AREA SO DID NOT GO TOO COLD. OTHERWISE TEMPERATURES
SHOULD BE AT OR ABOVE NORMAL WITH MAINLY SOUTHWEST OR ZONAL UPPER
FLOW THE REST OF THE PERIOD.
&&
.AVIATION...SNOW AND MOSTLY IFR CONDITIONS ARE EXPECTED TO
CONTINUE THIS AFTERNOON AND TONIGHT. THE SNOW WILL DIMINISH TO
SNOW SHOWERS OR FLURRIES OVERNIGHT. MVFR CEILINGS AND SNOW SHOWERS
ARE EXPECTED SATURDAY.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ005-
010>013-018>022-030-031-035>040-045-048>050-073-074.
&&
$$