Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/06/14
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1013 PM EST FRI DEC 5 2014
.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHERN PLAINS WILL TREK TOWARDS THE
REGION THRU SAT. STRONG HIGH PRESSURE WILL PASS TO THE NORTH FROM
SUNDAY INTO MONDAY. A COASTAL STORM WILL THEN LIKELY IMPACT THE
REGION FROM MONDAY NIGHT INTO WEDNESDAY...FOLLOWED BY FAIR WEATHER
FOR THURSDAY AND FRIDAY AS THE STORM PULLS SLOWLY AWAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
BASED ON LATEST HURR, RAP AND RADAR TRENDS...RAIN BECOMES LIGHTER
STARTING JUST BEFORE MIDNIGHT FROM WEST TO EAST. WILL USE LIGHT
RAIN. RAIN SHOULD STOP OR BECOME INTERMITTENT OVERNIGHT AS THE
WARM FRONT LIFT TO THE NORTH.
IN WESTERN ORANGE COUNTY...TEMPS ARE AT FREEZING OR JUST ABOVE.
BASED ON REPORTS OF ICING ON ROADS AND DOT REPORTS OF ROADWAY
TEMPS BEING BELOW AIR TEMPS WILL MAKE THE WSW EXPIRE AT 1 AM IN
CONCERT WITH THE ADVISORY FOR NW NJ.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
FORECAST IS ON TRACK WITH THE LATEST NWP.
FRONTOGENESIS ALONG THE WARM FRONT ON THE NORTH SIDE OF THE
FORECAST AREA FROM THE MID HUDSON VALLEY TO NORTHERN CT AS SFC LOW
PRESSURE TRACKS EAST ACROSS VA. THUS EXPECT DRY WX FOR A GOOD
PORTION OF THE MORNING AND EARLY AFTN. THERE AFTER...THE FRONT
GETS PUSHED SOUTHEAST AS THE 1045 HP HIGH BUILDS TO THE NORTH.
A BRIEF CHANGE TO SNOW IS POSSIBLE BEFORE THE PCPN TOTALLY
ENDS...BUT LITTLE TO NO ACCUM IS LIKELY.
WITH THE TRACK OF THE MAIN LOW S OF THE AREA AND ONGOING
PCPN...GUIDANCE LOOKS TOO WARM FOR TEMPS AND WENT CLOSER TO THE
NAM 2M DATA.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
PCPN SHOULD BE OVER BY DAYBREAK SUNDAY...WITH CLEARING SKIES AS
STRONG ARCTIC HIGH PRESSURE BUILDS TO THE NORTH. SIDED WITH COLDER
MET GUIDANCE FOR SUNDAY...WITH HIGHS REMAINING IN THE 30S...AND A
BRISK N-NE FLOW KEEPING WIND CHILLS IN THE 20S. MON MAY NOT BE MUCH
DIFFERENT AS H8 TEMPS AND H8-10 THICKNESSES REMAIN FAIRLY CONSTANT.
ATTENTION THEN TURNS TO THE STORM EXPECTED TO DEVELOP OFF THE EAST
COAST BEGINNING MON NIGHT. SIDING MORE AND MORE WITH A MORE
AMPLIFIED SOLUTION PER LAST TWO RUNS OF THE ECMWF FOR THIS EVENT...
AS AN AMPLIFYING NRN STREAM PHASES WITH A PAIR OF DISTINCT
SHORTWAVES MIGRATING FROM THE NRN ROCKIES AND DESERT SW IN SPLIT
FLOW ALOFT...AND A WEAK SFC WAVE ALONG A STALLED FRONTAL ZONE OFF
THE SE COAST. TREND HAS BEEN FOR THIS LOW TO DEVELOP CLOSER TO THE
COAST LATE MON NIGHT TUE MORNING...THEN QUICKLY INTENSIFY OFF THE
MID ATLANTIC COAST. LATEST RUNS OF THE ECMWF AND THE 00Z ECMWF
ENS MEAN DIVERGE FROM THAT POINT ON...WITH THE OPERATIONAL RUNS
TRENDING TOWARD A MORE INTENSE LOW WITH WARM SECLUSION REACHING PEAK
INTENSITY TUE NIGHT NEAR THE NY BIGHT...AND THE 00Z ENS MEAN SHOWING
A MORE OFFSHORE LOW TRACK. GIVEN THE INCREASING POTENTIAL FOR
GREATER PHASING OF THE VARIOUS STREAMS ALOFT...THINK THE OPERATIONAL
TREND IS MORE ON TRACK.
IN TERMS OF SENSIBLE WX...AN INITIAL SHOT OF WAA PCPN MON
NIGHT-TUE MORNING...WITH WARMING TEMPS ALOFT BUT REMAINING COLD AT
THE SFC AS THE ARCTIC HIGH DEPARTS...COULD YIELD A PD OF SNOW
CHANGING TO MIXED PCPN INLAND...WITH MAINLY RAIN AT THE COAST.
THEN AS THE COASTAL LOW WINDS UP...THINK PCPN LATE TUE MORNING
INTO TUE AFTERNOON SHOULD BE ALL RAIN...WHICH COULD BE HEAVY AT
TIMES GIVEN STRENGTHENING ATLANTIC INFLOW AND COUPLED JET ENERGY.
AS THE LOW REACHES PEAK INTENSITY...WOULD EXPECT DYNAMIC COOLING
WITH DEVELOPING COMMA HEAD PCPN TO THE NORTH/WEST OF THE SFC LOW
TO QUICKLY CHANGE PCPN BACK TO ACCUMULATING SNOW NORTH/WEST OF NYC
TUE EVENING AND CONTINUE INTO WED MORNING...WITH SOME POTENTIAL FOR
SIGNIFICANT SNOWFALL. FARTHER SOUTH/EAST...A MORE GRADUAL CHANGE TO
MIXED PCPN AND THEN LIGHT SNOW FOR NYC METRO...COASTAL SECTIONS
AND SE CT FOR LATE TUE NIGHT INTO WED MORNING APPEARS MORE LIKELY.
EXACT SFC LOW TRACK AND INTENSITY ARE UNCERTAIN... BUT THERE IS ALSO
POTENTIAL FOR A PD OF STRONG E-NE WINDS SOME TIME TUE NIGHT THAT
COULD IMPACT COASTAL SECTIONS IF THE LOW TRACKS JUST TO THE SOUTH.
WITH THE LOW SLOW TO PULL AWAY...LINGERING SNOW SHOWERS COULD BE
AROUND WED INTO WED NIGHT. THEN FAIR AND COLD/BRISK BUT NOT
UNSEASONABLY COLD WX EXPECTED FOR THU/FRI.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
LOW PRESSURE WILL APPROACH TONIGHT AND PASS ACROSS THE REGION
SATURDAY.
MAINLY IFR OVERNIGHT IN RAIN AND FOG. AT TIMES...CEILINGS/VSBYS MAY
IMPROVE TO MVFR...OR LOWER TO LIFR BRIEFLY.
THE LOW IFR CEILINGS AND/OR VSBYS SHOULD CONTINUE THROUGH THE DAY
SATURDAY IN INTERMITTENT RAIN.
EASTERLY WINDS LIGHTEN OVERNIGHT...AND MAY BECOME QUITE VARIABLE AS
THE FRONT NEARS THE AREA. SOUTH WINDS UNDER 10 KTS ARE EXPECTED LATE
SATURDAY MORNING AND INTO THE AFTERNOON BEFORE WINDS SHIFT LATE IN
THE DAY TO THE NORTH.
.OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
.SAT NIGHT...RAIN ENDS WITH IMPROVEMENT TO VFR AFTER MIDNIGHT. WINDS
SHIFT N IN THE EVENING...INCREASING TO 20KT WITH GUSTS 25-30KT.
.SUN...VFR. N 20KT GUSTS 25-30KT.
.MON...VFR AM. CHC MVFR AND -RA PM. E 10KT.
.TUE...MVFR/IFR IN RAIN. NE 10-20KT. CHC GUSTS 25-30KT.
.WED...CHC MVFR/IFR IN MIXED PCPN. NW 10-15KT GUSTS 20-25KT.
&&
.MARINE...
WINDS DIMINISHING OVERNIGHT...BUT SEAS WILL TAKE A WHILE TO
SUBSIDE FROM 5-8 FT THAT`S REPORTED AS OF 9 PM. THUS...SCA
CONTINUES INTO THE MORNING.
NLY WINDS INCREASE SAT NGT AS LOW PRES PASSES S OF THE WATERS. A
GALE WATCH REMAINS IN EFFECT FOR ALL OF THE WATERS EXCEPT FOR THE
HARBOR AND WRN SOUND.
GALE WATCH RUNS INTO SUNDAY AFTERNOON FOR THE OCEAN WATERS AND THE
ERN SOUND/BAYS...WITH GUSTS 35-40 KT POSSIBLE IN N-NE FLOW BETWEEN
ARCTIC HIGH PRESSURE TO THE NORTH AND LOW PRESSURE OFF THE SE COAST.
GALES COULD LINGER INTO SUNDAY EVENING ON THE OCEAN OUT EAST...
OTHERWISE EXPECT SCA CONDS ON ALL WATERS INTO SUNDAY NIGHT/MON
MORNING...THEN OCEAN SEAS REMAINING ELEVATED MON INTO MON NIGHT.
HAVE FORECAST SCA CONDS FOR TUE-TUE NIGHT WITH THE COASTAL STORM
MAINLY ON THE OCEAN...BUT THIS SITUATION IS HIGHLY UNCERTAIN...AND
GALES COULD BE POSSIBLE ON ALL WATERS TUE NIGHT IF THE LOW TRACK AND
INTENSITY ARE IDEAL. SCA CONDS LIKELY TO LINGER IN NW FLOW ON THE
BACK SIDE OF THE SLOWLY DEPARTING LOW WED INTO WED NIGHT.
&&
.HYDROLOGY...
UP TO AN INCH AND A HALF OF LIQUID CAN BE EXPECTED THRU SAT NGT.
SIGNIFICANT QPF OF 1.5 TO 2 INCHES POSSIBLE WITH A COASTAL
STORM...MAINLY FROM LATE MON NIGHT INTO WED MORNING. PART OF THIS
SHOULD FALL AS SNOW ESPECIALLY NORTH/WEST OF NYC. NUISANCE
HYDROLOGIC IMPACTS POSSIBLE TUE AFTERNOON/EVENING WITH ANY HEAVY
RAINFALL.
&&
.TIDES/COASTAL FLOODING...
A FULL MOON AND RESIDUAL SURGE WILL PRESENT A VERY LOW
PROBABILITY FOR MINOR INUNDATION OF THE MOST VULNERABLE LOCALES
ALONG THE SOUTH SHORE BAYS OF WESTERN LI AND NYC DURING THE SAT
MORNING HIGH TIDE. THE PROBABILITY IS TOO LOW TO ISSUE A STATEMENT
ATTM.
A PROLONGED PERIOD OF MODERATELY HIGH EASTERLY SWELLS SUNDAY
THROUGH EARLY NEXT WEEK WILL LIKELY RESULT IN EROSION ISSUES ALONG
THE BARRIER BEACHES. MINOR COASTAL FLOODING IS ALSO POSSIBLE
DURING THE TIME OF HIGHER HIGH TIDES EARLY NEXT WEEK DUE TO A
DEVELOPING COASTAL LOW.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 1 AM EST SATURDAY FOR NYZ067.
NJ...NONE.
MARINE...GALE WATCH FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON FOR
ANZ330-340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ353-355.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SATURDAY FOR ANZ350.
&&
$$
SYNOPSIS...JMC/GOODMAN
NEAR TERM...TONGUE
SHORT TERM...JMC/TONGUE
LONG TERM...GOODMAN
AVIATION...PW
MARINE...JMC/GOODMAN/TONGUE
HYDROLOGY...JMC/GOODMAN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NWS KEY WEST FL
931 PM EST FRI DEC 5 2014
.DISCUSSION...
.CURRENTLY...
EASTERLY WINDS HAVE USHERED IN SOME ADDED CLOUD COVER THIS EVENING.
THE EVENING SOUNDING SHOWS THE EASTERLY WINDS THROUGH THE 750 MB
AN AFTERNOON ASCAT PASS DIRECTLY OVER THE AREA SHOWS A SWATH OF 15 TO
20 KNOTS ACROSS THE STRAITS WHICH IS SUPPORTED BY MARINE OBSERVATION
ALONG HAWK CHANNEL. ISLAND LOCATIONS ARE 5 TO 10 KNOTS WHILE MARINE
LOCATIONS NORTH OF THE ISLAND CHAIN HAVE MEASURED WINDS AT 10 TO 15
KNOTS. JUST FOUND A RAPIDSCAT PASS ALSO DIRECTLY OVER THE KEYS...AS
OF 09 LOCAL...02Z...INDICATING 15 TO 20 KNOTS OVER THE STRAITS.
.FORECAST...
SHOWERS DEVELOPING IN SPEED CONVERGENCE ACROSS THE AREA AT THIS
HOUR...ARE VERY SHALLOW...WILL BE SHORT LIVED...AND WILL PRODUCE UP
TO SEVERAL HUNDREDTHS OF AN INCH OF RAINFALL. THESE ARE MOVING AT 15
TO 20 KNOTS ACROSS THE AREA FROM EAST TO WEST. WITH THE MOTION OF
THESE SHOWERS AND THE COMBINATION OF THE RECENT OBSERVATIONS
INCLUDING ASCAT AND RAPIDSCAT WILL LOWER WINDS SLIGHTLY AHEAD OF
SCHEDULE WHICH WILL BE THE ONLY CHANGE IN THE CURRENT FORECAST. THE
HIGH RESOLUTION RAPID REFRESH LOCAL MESOSCALE MODEL HAS DONE A VERY
GOOD JOB WITH WINDS AND RAINFALL LEADING INTO THE FORECAST SCHEME
THIS EVENING SO WILL LEAD MOSTLY ON THE HRRR IN THE SHORT TERM.
&&
.MARINE...
WITH THE LOCAL MESO SCALE MODEL WORKING WELL HAVE LOWERED THE SMALL
CRAFT ADVISORY ACROSS THE STRAITS...BUT WILL URGE SMALL CRAFT TO
EXERCISE CAUTION UNTIL WINDS AND SEAS SUBSIDE FURTHER.
OBVIOUSLY...WINDS NORTH OF THE ISLAND CHAIN WILL BE LOWER DUE TO
DECOUPLING OF WINDS OVER COOLER WATERS.
&&
.AVIATION...
OVERNIGHT...VFR CONDITIONS WILL PREVAIL AT THE ISLAND TERMINALS
OVERNIGHT. EXPECT SCATTERED CLOUDS WITH BASES AOA FL020-025 AGL.
VERY BRIEF MVFR CIGS AND OR VIS WILL BE POSSIBLE WITHIN ISOLATED
SHOWERS...BUT DURATION AND PROBABILITY TOO LOW TO INCLUDE IN TAF
ATTM. SURFACE WINDS WILL AVERAGE BETWEEN 050-070 DEGREES AOA 10-12
KNOTS.
&&
.CLIMATE...
ON THIS DATE IN KEYS WEATHER HISTORY...1876...THE MERCURY DIPPED TO
45 DEGREES IN KEY WEST. THIS SET THE DAILY RECORD MINIMUM TEMPERATURE
FOR KEY WEST ON DECEMBER 5TH...WHICH STANDS 138 YEARS LATER.
TEMPERATURE RECORDS FOR KEY WEST DATE BACK TO 1872.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........BWC
AVIATION/NOWCASTS.....FUTTERMAN
DATA COLLECTION.......CHESSER
VISIT US ON THE WEB AT WEATHER.GOV/KEY
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AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
833 PM EST FRI DEC 5 2014
...MILD AND FOGGY TONIGHT WITH A FEW LIGHT SHOWERS...
.UPDATE...YET ANOTHER COASTAL TROUGH HAS FORMED OFFSHORE OF THE
FIRST COAST AGAIN ONLY DEPICTED WELL BY THE NAM12 WHICH SHOWED A
STRONG NNE WIND GRADIENT DOWN THE LOCAL SEABOARD. SEA FOG
CONTINUED TO IMPACT OUR COASTAL SITES...WITH SOME INLAND
PROGRESSION OVER THE ESTUARIES. THE HRRR MODEL CONTINUED TO
SUGGEST THE SEA FOG DRIFTING INLAND OVERNIGHT...BUT GIVEN ELEVATED
WINDS OF NEAR 15 KTS ABOVE THE SURFACE AND SOME SHALLOW ISENTROPIC
LIFT AS EVIDENCED BY A FEW PATCHES SPRINKLES DRIFTING NWD OVER
MARION COUNTY...WILL CONTINUE TO HANDLE PATCHY DENSE FOG ALONG THE
COAST AND THAT FORMS INLAND THROUGH THIS EVENING WITH A SPECIAL
WEATHER STATEMENT IN LIEU OF AN ADVISORY DUE TO LOWER CONFIDENCE.
THE PRESENCE OF THE ELEVATED BOUNDARY LAYER WINDS AND PASSING
MID/HIGH CLOUDS AGAIN MAKE FOR LESS THAN IDEAL PERSISTENT DENSE
FOG CONDITIONS. HIGH CLOUDS WILL BEGIN TO CLEAR OUT FROM THE WNW
LATE TONIGHT/EARLY SAT MORNING...WITH PERHAPS VSBYS DROPPING
INLAND DUE TO BETTER RADIATIONAL COOLING CONDITIONS. TEMPS WILL BE
MILD AND RANGE FROM MINS IN THE LOWER 60S COAST TO THE MID 50S
WELL INLAND UNDER CLOUDY TO PARTLY CLOUDY SKIES.
&&
.AVIATION...EXPECT SEA FOG TO PERSIST TONIGHT AS IT SPREADS INLAND.
CURRENTLY VLIFR CONDITIONS AT JAX AND CRG WITH LIFR AT VQQ. EXPECT
SSI AND GNV TO ALSO GO DOWN TO LIFR BY 06Z. EXPECT CONDITIONS TO
SLOWLY IMPROVE AROUND 14-15Z TO MVFR AND THEN IFR BY 17Z AS WINDS
BECOME OFFSHORE ON SATURDAY.
&&
.MARINE...SEA DENSE FOG CONTINUED TO AFFECT THE NEAR SHORE WATERS
WITH RECENT REPORTS STATING DENSE FOG LESSENED ALONG THE FLAGLER
COUNTY COAST. WILL CONTINUE TO LEAVE THE CURRENT MARINE DENSE FOG
ADVISORY IN PLACE FOR THE NEAR SHORE WATERS...BUT AS THE COASTAL
TROUGH WEAKENS OVERNIGHT AND MORE MIXING APPROACHES AT LEAST OUR
SOUTHERN NEAR SHORE WATERS...THE ADVISORY MAY NEED TO BE TRIMMED
NORTHWARD FOR ONLY OUR NEAR SHORE ZONES N OF ST AUGUSTINE. AROUND
830 PM...FERNANDINA BEACH REPORT 1/2 SM...MAYPORT REPORTED 1/4
SM...ST AUGUSTINE WAS 1 1/2 SM...AND ST SIMONS ISLAND WAS 8 SM BUT
STILL BLANKETED WITH LOW STRATUS.
THE NAM12 HAD THE BEST HANDLE ON THE STRENGTH OF THE COASTAL
TROUGH THIS EVENING WITH ELEVATED NNE WINDS 15-20 KTS ALONG THE
IMMEDIATE COASTLINE DUE TO THE PINCHED PRESSURE GRADIENT. WILL
CONTINUE TO LEAN TOWARD THIS SOLUTION TONIGHT WHICH WILL BRING
SMALL CRAFT EXERCISE CAUTION CONDITIONS FOR THE NEAR SHORE WATERS
THIS EVENING...AND THE OFFSHORE WATERS DUE TO LINGERING ELEVATED
SEAS OF 5-6 FT. WINDS/SEAS WILL RELAX LATE TONIGHT/EARLY SAT
MORNING AS WEAK HIGH PRESSURE SETTLES OVER THE WATERS AND WINDS
BECOME VARIABLE 10 KTS OR LESS.
WINDS INCREASE SUN TRAILING A DRY COLD FRONTAL PASSAGE WITH SMALL
CRAFT ADVISORY CONDITIONS ANTICIPATED FOR THE OFFSHORE WATERS INTO
TUESDAY.
RIP CURRENTS: LOW RISK EXPECTED ON SATURDAY DUE TO LIGHT WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 56 75 52 66 / 10 20 20 10
SSI 58 72 55 64 / 10 10 10 10
JAX 59 76 55 67 / 10 10 10 10
SGJ 61 74 58 67 / 10 10 10 10
GNV 58 78 56 71 / 20 10 10 10
OCF 58 79 57 73 / 20 10 10 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...DENSE FOG ADVISORY UNTIL 10 AM EST SATURDAY FOR ALTAMAHA SOUND
GA TO FERNANDINA BEACH FL OUT 20 NM-FERNANDINA BEACH TO ST
AUGUSTINE FL OUT 20 NM-ST AUGUSTINE TO FLAGLER BEACH FL OUT
20 NM.
&&
$$
ENYEDI/ZIBURA/GUILLET
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
330 PM EST THU DEC 4 2014
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UNAMPLIFIED UPPER LEVEL
PATTERN ACROSS THE CONUS. FLOW IS MAINLY ZONAL AND PROGRESSIVE IN
NATURE...INCLUDING ACROSS THE NORTHERN GULF AND FLORIDA PENINSULA.
DO SEE A WEAK SHORTWAVE TROUGH MOVING ASHORE ACROSS THE BAJA
REGION/SW STATES. THIS ENERGY WILL MAKE ITS WAY ACROSS THE DEEP
SOUTH...BUT HAVE NO IMPACT ON OUR LOCAL WEATHER THROUGH THE DURATION
OF THE UPCOMING WEEKEND. 04/12Z KTBW SOUNDING SHOWS A VERY DRY
COLUMN IN THE MID-LEVELS 700-500MB...HOWEVER THE DEPTH OF THE DRY
LAYER HAS BEEN DIMINISHED SINCE WEDNESDAY EVENING...WITH
CONSIDERABLY MORE MOISTURE ABOVE 500MB. LOOKING AT WV THIS SINCE
THIS MORNING...IT IS LIKELY THAT THIS HIGHER MOISTURE IN THE UPPER
LEVELS HAS EXITED OFF TO THE EAST AND THE EVENING SOUNDING SHOULD
COME IN DRIER ONCE AGAIN.
AT THE SURFACE...HIGH PRESSURE CENTERED OVER THE NORTHEASTERN STATES
RIDGES ALL THE WAY DOWN THE EASTERN SEABOARD TO THE EASTERN GULF/FL
PENINSULA...PROVIDING OUR REGION WITH A SYNOPTIC LOW LEVEL FLOW FROM
THE NORTHEAST. LOWER LEVELS MIXED TO AROUND 5000 FEET ON
WEDNESDAY...AND EXPECT SIMILAR CONDITIONS TO END OUT TODAY. BASED ON
THE MORNING SOUNDING...A BOUNDARY LAYER THIS HIGH SHOULD MIX OUT OUR
AFTERNOON TEMPS INTO THE UPPER 70S AND LOWER 80S. CROSS-SECTIONAL
ANALYSIS WHICH SHOWED DECENT MOISTURE UNDER 700MB SEEMS TO BE RIGHT
AS IT IS SUPPORTING A SCT SHALLOW CUMULUS FIELD UNDERNEATH THE DRY
MID-LEVELS.
SIMILAR TO PREVIOUS DAYS...THE ONSHORE SPEED CONVERGENCE FLOW ALONG
THE EAST COAST ALONG WITH DIURNAL HEATING IS SUPPORTING A FEW LIGHT
SHOWERS/SPRINKLES MIGRATING INTO OUR COUNTIES FROM THE EAST THROUGH
THE AFTERNOON HOURS. LOW LEVEL MOISTURE IS SLIGHTLY DEEPER TO THE
SOUTH OF I-4...AND THIS IS WHERE THE MAJORITY OF THE SPRINKLES WILL
REMAIN THROUGH THE EARLY EVENING HOURS BEFORE ACTIVITY DISSIPATES.
ANY RAINFALL SHOULD HAVE A VERY LIMITED IMPACT ON OUTDOOR
ACTIVITIES.
&&
.SHORT TERM (TONIGHT AND FRIDAY)...
SREF ENSEMBLE GUIDANCE (WHICH DID A VERY GOOD JOB WITH THE LOWER
CLOUD/FOG AREAS THIS PAST MORNING) IS STRONGLY SHOWING ANOTHER LOWER
STRATUS/FOG EVENT BUILDING DOWN TO AROUND (OR JUST NORTH) THE I-4
CORRIDOR DURING THE SECOND HALF OF TONIGHT / EARLY FRIDAY MORNING.
THE STATISTICAL MOS IS ALSO FAIRLY AGGRESSIVE AT OUR NORTHERN
STATIONS. ALWAYS DIFFICULT TO DETERMINE IF THESE EVENTS WILL BE
DENSE FOG...OR JUST A VERY LOW STRATUS DECK AT 2-5 HUNDRED FEET
ABOVE THE GROUND. THIS PAST MORNING TENDED TO BE MORE OF A STRATUS
EVENT OVER OUR ZONES...BUT WAS MORE OF A FOG EVENT FURTHER NORTH.
SINCE THE WHOLE PATTERN IS SHIFTING SOUTHWARD A BIT FOR TONIGHT...
HAVE DECIDED TO EXPAND THE FOG AREAS IN THE CURRENT FORECAST GRIDS
AND ADDED SOME WORDING OF POTENTIAL DENSE FOG (FROM AROUND
BROOKSVILLE NORTHWARD) AS WE APPROACH DAWN FRIDAY MORNING. THE
GRADIENT MAY HOLD UP JUST ENOUGH TO KEEP THIS ANOTHER MAINLY STRATUS
EVENT...BUT JUST TOO CLOSE TO CALL. SOMETHING TO KEEP IN MIND IF
HEADING OUT EARLY FRIDAY MORNING FROM HILLSBOROUGH AND POLK COUNTIES
NORTHWARD THROUGH THE NATURE COAST. IN TERMS OF TEMPERATURES...
EXPECTING SEASONABLE READINGS OF MID/UPPER 50S NORTH...AND LOWER TO
MIDDLE 60S FROM THE I-4 CORRIDOR SOUTHWARD.
FRIDAY...
WEAK RIDGING OVER THE SOUTHERN GULF OF MEXICO IS FORECAST TO EXPAND
NORTHWARD INTO THE EASTERN GULF AND OVER THE FLORIDA PENINSULA
DURING THE DAYLIGHT HOURS. THIS WILL ONLY HAVE A SLIGHT EFFECT OF
TURNING OUR FLOW ALOFT FROM ZONAL TO MORE ANTI-CYCLONIC IN NATURE.
THE BUILDING HEIGHTS SHOULD ALSO ALLOW TEMPERATURES TO WARM ANOTHER
DEGREE OR 2 FROM FRIDAY. SURFACE RIDGE WILL CONTINUE TO BUILD DOWN
THE EASTERN SEABOARD AND THE GRADIENT LOOKS TIGHT ENOUGH TO SUPPORTS
SOME BREEZY CONDITIONS FOR THE LATE MORNING/AFTERNOON HOURS. MOST
LOCATIONS SHOULD WARM UP TO MID-AFTERNOON READINGS IN THE UPPER 70S
FAR NORTH...TO LOWER 80S CENTRAL ZONES...AND LOWER/MID 80S DOWN
TOWARD PUNTA GORDA AND FORT MYERS. SIMILAR TO FRIDAY...JUST THE
OUTSIDE CHANCE OF A FEW ISOLATED SHOWERS/SPRINKLES MIGRATING
WESTWARD ACROSS THE PENINSULA DURING THE AFTERNOON FROM THE I-4
CORRIDOR SOUTHWARD. SPRINKLES SHOULD NOT HAVE MUCH IMPACT ON OUTDOOR
PLANS/ACTIVITIES.
HAVE A GREAT EVENING EVERYONE!
&&
.LONG TERM (SATURDAY THROUGH NEXT THURSDAY)...
MODELS IN FAIR AGREEMENT WITH THE SURFACE FEATURES WHILE SOME SLIGHT
DIFFERENCES IN UPPER LEVELS. WILL EXPECT MAINLY WARM...DRY AND HUMID
CONDITIONS THROUGH SATURDAY. WEAK COLD FRONT TO MOVE OVER THE REGION
SUNDAY WITH ONLY A SLIGHT CHANCE OF RAIN ASSOCIATED WITH THE FRONT
AND DROPPING TEMPERATURES TO AROUND SEASON NORMS TO END THE WEEKEND.
COOLER HIGH PRESSURE BUILDS DOWN THE EASTERN SEABOARD EARLY NEXT
WEEK KEEPING COOL AND MAINLY DRY CONDITIONS IN PLACE. RE-ENFORCING
HIGH PRESSURE TO BUILD INTO THE REGION BY MID WEEK ON NORTHEASTERLY
LOW LEVEL FLOW. NEXT WEEKS TEMPERATURES EXPECTED TO BE NEAR TO
SLIGHTLY BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
VFR CONDITIONS PREVAILING ACROSS THE REGION THIS AFTERNOON AND WILL
CONTINUE THROUGH THE EVENING HOURS. LARGE AREA OF IFR STRATUS/AND OR
FOG IS ANTICIPATED TO DEVELOP OVER NORTHERN FLORIDA AND EXTEND DOWN
TO NEAR KTPA/LAL. GUIDANCE CONSENSUS IS THAT THE MAIN AREA OF
RESTRICTIONS STAY NORTH OF THESE TERMINALS...SO FOR NOW WILL LEAVE
OUT OF TAFS...HOWEVER SITUATION/GUIDANCE WILL NEED TO BE WATCHED
CLOSELY AS CIGS/VIS RESTRICTIONS WILL NEED TO BE ADDED TO THESE
NORTHERN TERMINALS SHOULD THINGS SHIFT SOUTH. ANY MORNING
RESTRICTIONS WILL BURN OFF BY 14-15Z WITH VFR CONDITIONS THEN
PREVAILING FOR THE REMAINDER OF FRIDAY.
&&
.MARINE...
THE EASTERN GULF OF MEXICO WILL REMAIN ON THE SOUTHERN FRINGE OF A
LARGE SURFACE HIGH PRESSURE SYSTEM CENTERED WELL NORTH OF THE
REGION. OFF SHORE WINDS WILL PREVAIL OVER THE NEXT COUPLE OF DAYS
WITH A NOCTURNAL SURGE DEVELOPING EARLY FRIDAY MORNING INCREASING
WINDS TO AROUND 15 KT IN THE OFF SHORE WATERS. A WEAK SURFACE
BOUNDARY WILL LINGER IN THE VICINITY OF PENINSULA OVER THE WEEKEND
BUT WILL NOT PRODUCE ANY SIGNIFICANT CHANGES IN THE PATTERN.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL CONTINUE TO RIDGE DOWN THE EASTERN SEABOARD INTO
THE REGION THROUGH THE DAY ON FRIDAY. THIS RIDGE WILL BRIEFLY BREAK
DOWN ON SATURDAY AS A COLD FRONT APPROACHES AND PASSES TROUGH THE
REGION SATURDAY NIGHT AND SUNDAY. A NEW RIDGE OF HIGH PRESSURE
BUILDS SOUTHWARD INTO THE REGION FOR THE EARLY PORTION OF NEXT WEEK.
RELATIVE HUMIDITY VALUES ARE EXPECTED TO REMAIN ABOVE CRITICAL
LEVELS THE NEXT SEVERAL DAYS...AND OTHER THAN AREAS OF HIGH
DISPERSION INDICES FRIDAY AFTERNOON...NO SIGNIFICANT FIRE WEATHER
CONCERNS ARE ANTICIPATED THROUGH SATURDAY.
FOG POTENTIAL...AREAS OF LOW STRATUS AND FOG ARE EXPECTED EARLY
FRIDAY MORNING...ESPECIALLY NORTH OF THE I-4 CORRIDOR. THIS LOW
CLOUD AND FOG SHOULD BURN OFF DURING THE MIDDLE MORNING HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 65 80 65 79 / 0 20 10 20
FMY 65 83 66 82 / 10 20 10 10
GIF 63 81 62 80 / 10 20 0 20
SRQ 64 81 64 79 / 0 10 0 10
BKV 59 81 59 80 / 0 10 0 20
SPG 66 79 65 78 / 0 10 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/FIRE WEATHER...MROCZKA
MARINE...BARRON
LONG TERM...DAVIS
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1040 AM EST THU DEC 4 2014
.UPDATE (REST OF TODAY)...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UNAMPLIFIED UPPER LEVEL
PATTERN ACROSS THE CONUS. FLOW IS MAINLY ZONAL AND PROGRESSIVE IN
NATURE...INCLUDING ACROSS THE NORTHERN GULF AND FLORIDA PENINSULA.
DO SEE A WEAK SHORTWAVE TROUGH MOVING ASHORE ACROSS THE BAJA
REGION/SW STATES. THIS ENERGY WILL MAKE ITS WAY ACROSS THE DEEP
SOUTH...BUT HAVE NO IMPACT ON OUR LOCAL WEATHER THROUGH THE DURATION
OF THE UPCOMING WEEKEND. 04/12Z KTBW SOUNDING SHOWS A VERY DRY
COLUMN IN THE MID-LEVELS 700-500MB...HOWEVER THE DEPTH OF THE DRY
LAYER HAS BEEN DIMINISHED SINCE WEDNESDAY EVENING...WITH
CONSIDERABLY MORE MOISTURE ABOVE 500MB. LOOKING AT WV THIS
MORNING...IT IS LIKELY THAT THIS HIGHER MOISTURE IN THE UPPER LEVELS
IS NOW EXITING OFF TO THE EAST AND THE EVENING SOUNDING WILL COME IN
DRIER ONCE AGAIN. EARLIER UPPER LEVEL CLOUDS ASSOCIATED WITH THIS
MOISTURE HAVE MIGRATED OFF TO OUR EAST LEAVING MOSTLY CLEAR SKIES
AND PLENTY OF SUNSHINE TO WARM US UP.
AT THE SURFACE...HIGH PRESSURE CENTERED OVER THE NORTHEASTERN STATES
RIDGES ALL THE WAY DOWN THE EASTERN SEABOARD TO THE EASTERN GULF/FL
PENINSULA...PROVIDING OUR REGION WITH A SYNOPTIC LOW LEVEL FLOW FROM
THE NORTHEAST. EXTENSIVE LOWER STRATUS/FOG UNDER THE NOCTURNAL
INVERSION THAT FORMED OVERNIGHT TO THE NORTH OF THE I-4 CORRIDOR WAS
UNDER 1000 FEET THICK AND HAS BURNED OFF QUICKLY IN THE PAST FEW
HOURS. LATEST VISIBLE SATELLITE IMAGERY SHOWS NO SIGNS LEFT OF THIS
EARLIER OVERCAST/FOG. HOWEVER...ALL INDICATIONS ARE THAT IT WILL BE
RETURNING TO THE NORTHERN HALF OF THE PENINSULA DURING THE SECOND
HALF OF TONIGHT. TEMPERATURES HAVE REBOUNDED INTO THE 70S AT ALL
LOCATIONS THIS MID-MORNING. LOWER LEVELS MIXED TO AROUND 5000 FEET
ON WEDNESDAY...AND EXPECT SIMILAR CONDITIONS FOR TODAY. BASED ON THE
MORNING SOUNDING...A BOUNDARY LAYER THIS HIGH SHOULD MIX OUT OUR
AFTERNOON TEMPS INTO THE MID/UPPER 70S NORTH AND LOWER 80S SOUTH.
CROSS-SECTIONAL ANALYSIS SHOWS ENOUGH MOISTURE UNDER 700MB TO
SUPPORT A FEW-SCT SHALLOW CUMULUS FIELD DEVELOPING THROUGH THE DAY
UNDERNEATH THE DRY MID-LEVELS.
SIMILAR TO PREVIOUS DAYS...THE ONSHORE SPEED CONVERGENCE FLOW ALONG
THE EAST COAST ALONG WITH DIURNAL HEATING SHOULD BE ENOUGH TO
SUPPORT A FEW LIGHT SHOWERS/SPRINKLES MIGRATING INTO OUR COUNTIES
FROM THE EAST THROUGH THE AFTERNOON HOURS. LOW LEVEL MOISTURE IS
SLIGHTLY DEEPER TO THE SOUTH OF I-4...AND WILL RUN THE BEST CHANCE
OF A BRIEF SHOWER OVER THESE SOUTHERN ZONES. JUST RUNNING A 20% PROB
OF SEEING A SHOWER...AND ANY RAINFALL SHOULD HAVE A VERY LIMITED
IMPACT ON ANY OUTDOOR ACTIVITIES.
AS MENTIONED ABOVE...SREF ENSEMBLE GUIDANCE (WHICH DID A VERY GOOD
JOB WITH THE LOWER CLOUD/FOG AREAS THIS PAST MORNING) IS STRONGLY
SHOWING ANOTHER LOWER STRATUS/FOG EVENT BUILDING DOWN TO AROUND THE
I-4 CORRIDOR DURING THE SECOND HALF OF TONIGHT / EARLY FRIDAY
MORNING. THE STATISTICAL MOS IS ALSO FAIRLY AGGRESSIVE AT OUR
NORTHERN STATIONS. ALWAYS DIFFICULT TO DETERMINE IF THESE EVENTS
WILL BE DENSE FOG...OR JUST A VERY LOW STRATUS DECK AT 2-5 HUNDRED
FEET ABOVE THE GROUND. THIS PAST MORNING TENDED TO BE MORE OF A
STRATUS EVENT OVER OUR ZONES...BUT WAS MORE OF A FOG EVENT FURTHER
NORTH. SINCE THE WHOLE PATTERN IS SHIFTING SOUTHWARD A BIT FOR
TONIGHT... HAVE DECIDED TO EXPAND THE FOG AREAS IN THE CURRENT
FORECAST GRIDS AND ADDED SOME WORDING OF POTENTIAL DENSE FOG (FROM
AROUND BROOKSVILLE NORTHWARD) AS WE APPROACH DAWN FRIDAY MORNING.
JUST SOMETHING TO KEEP IN MIND IF HEADING OUT EARLY FRIDAY MORNING
FROM HILLSBOROUGH AND POLK COUNTIES NORTHWARD THROUGH THE NATURE
COAST.
HAVE A GREAT REMAINDER OF YOUR THURSDAY!
&&
.AVIATION...
VFR CONDITIONS NOW PREVAIL ACROSS THE REGION. EARLY STRATUS/FOG
ALONG AND NORTH OF THE I-4 CORRIDOR HAS QUICKLY BURNED OFF. THE
REMAINDER OF THE DAY LOOKS BENIGN WITH LIGHT NORTHEAST WINDS AND A
DEVELOPING FEW-SCT CUMULUS FIELD. ENSEMBLE AND STATISTICAL GUIDANCE
IN AGREEMENT OF ANOTHER ROUND OF STRATUS/FOG ALONG AND NORTH OF THE
I-4 CORRIDOR. WILL EVALUATE THIS THREAT FURTHER WITH THE NEXT
GUIDANCE PACKAGE TO DETERMINE ANY EARLY MENTION FOR KTPA/KLAL/KPIE
WHO CURRENTLY LOOK TO SEE THE BEST CHANCES FOR ANY SIGNIFICANT EARLY
MORNING RESTRICTIONS. SIMILAR TO TODAY...EARLY MORNING RESTRICTIONS
SHOULD QUICKLY END BY AROUND 15Z...FOLLOWED BY PREVAILING VFR
CONDITIONS FOR THE REMAINDER OF YOUR FRIDAY.
&&
.MARINE...
THE EASTERN GULF OF MEXICO WILL REMAIN ON THE SOUTHERN FRINGE OF A
LARGE SURFACE HIGH PRESSURE SYSTEM CENTERED WELL NORTH OF THE
REGION. OFF SHORE WINDS WILL PREVAIL OVER THE NEXT COUPLE OF DAYS
WITH A NOCTURNAL SURGE DEVELOPING EARLY FRIDAY MORNING INCREASING
WINDS TO AROUND 15 KT IN THE OFF SHORE WATERS. A WEAK SURFACE
BOUNDARY WILL LINGER IN THE VICINITY OF PENINSULA OVER THE WEEKEND
BUT WILL NOT PRODUCE ANY SIGNIFICANT CHANGES IN THE PATTERN.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 65 79 65 / 0 0 20 0
FMY 80 65 82 66 / 20 10 10 0
GIF 77 63 78 62 / 10 10 20 0
SRQ 80 65 80 65 / 10 0 20 10
BKV 78 61 79 61 / 0 0 10 0
SPG 77 66 77 66 / 0 0 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...BARRON
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1031 PM EST FRI DEC 5 2014
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE NORTH WILL
WEAKEN AHEAD OF THE APPROACHING COLD FRONT. THE FRONT WILL MOVE
THROUGH THE AREA SATURDAY EVENING. DRYING BEHIND THE FRONT WILL
DOMINATE SUNDAY BUT MOISTURE MAY SPREAD BACK INTO THE REGION
MONDAY ASSOCIATED WITH LOW PRESSURE DEVELOPING OFF THE COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE EXTENDING INTO THE FORECAST AREA FROM THE NORTH
WILL WEAKEN OVERNIGHT. HIGH LOW- LEVEL MOISTURE AND WEAK
ISENTROPIC LIFT PLUS NOCTURNAL COOLING COULD PRODUCE SOME AREAS OF
STRATUS ACROSS THE EASTERN PORTION OF THE CWA PER THE EVENING
HRRR. OTHERWISE MAINLY MID/HIGH CLOUDS ACROSS THE AREA. MOISTURE
IS INITIALLY LOW WITH PW VALUES AROUND 0.75 INCHES BUT INCREASE
OVERNIGHT AND INTO SATURDAY TO AROUND 1.0 INCH. MODELS INDICATE
INCREASING ISENTROPIC LIFT FROM WEST/SOUTHWEST OVERNIGHT AND INTO
SATURDAY. CURRENT RADAR ACROSS THE SOUTHEAST/MID MS RIVER VALLEY
SHOWS SHOWERS/THUNDERSTORMS ACROSS MS/AL/TN WHERE BEST ISENTROPIC
/MID-UPPER LEVEL FORCING OCCURRING. THIS WILL SHIFT EASTWARD INTO
SATURDAY. FORECASTED POPS FOR THE NORTHWESTERN PORTION OF THE CWA
LATE TONIGHT AND THEN MOVING INTO THE MIDLANDS BY SATURDAY
MORNING. CLOUDINESS SHOULD HELP HOLD UP TEMPERATURES. THE MAV AND
MET MOS WERE CLOSE WITH LOWS IN THE UPPER 40S TO AROUND 50.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
MOISTURE WILL INCREASE AHEAD OF THE COLD FRONT SATURDAY. THE NAM
WAS STILL A LITTLE SLOWER COMPARED TO THE GFS WITH THE PLACEMENT
OF DEEPEST MOISTURE AHEAD OF THE FRONT. USED AN AVERAGE OF THE
GUIDANCE FOR THE TIMING OF HIGHEST POPS. STRONGER UPPER-LEVEL LIFT
AND DEEPER MOISTURE SUPPORTED THE HIGHEST POPS IN THE NORTH PART
OF THE FORECAST AREA. USED THE GUIDANCE CONSENSUS WITH CHANCE POPS
SOUTH AND LIKELY NORTH. A THUNDERSTORM IS NOT OUT OF THE QUESTION
BECAUSE OF COOLING ALOFT AHEAD OF THE SHORTWAVE TROUGH AND AN H5
DIFLUENT PATTERN PLUS LOW-LEVEL WARMING AHEAD OF THE FRONT.
HOWEVER...THE MODEL FORECAST SOUNDINGS HAD LITTLE CAPE AND
LIGHTNING WAS NOT EVIDENT UPSTREAM. BELIEVE THE THUNDERSTORM
CHANCE IS TOO LOW TO INCLUDE IN THE FORECAST AT THIS TIME. THE
TEMPERATURE GUIDANCE WAS CLOSE SATURDAY BUT MAY BE A LITTLE TOO
COOL JUST AHEAD OF THE COLD FRONT.
DRYING SHOULD OCCUR BEHIND THE FRONT SATURDAY NIGHT AND THE MODELS
HAVE BEEN CONSISTENT SHOWING DRY CONDITIONS CONTINUING SUNDAY. THE
PRESSURE GRADIENT BETWEEN THE RIDGE TO THE NORTHWEST AND OFFSHORE
FRONT WILL LIKELY RESULT IN BREEZY CONDITIONS SUNDAY. THE NAM MOS
HAD LESS WIND COMPARED TO THE GFS MOS. WE LEANED TOWARD MORE WIND
BASED ON THE EXPECTED GRADIENT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MODELS HAVE TRENDED BACK TO MORE MOISTURE MONDAY ASSOCIATED
WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST. THIS MOISTURE
APPEARS DEEPEST IN THE NORTHEAST SECTION. THE GFS AND ECMWF MOS
POPS WERE NEAR 30 PERCENT. THE LOW SHOULD BE FARTHER NORTHEAST OF
THE AREA TUESDAY WITH DRY RIDGING DOMINATE DURING THE REST OF THE
MEDIUM-RANGE PERIOD. CLOUDINESS AND A NORTHEAST FLOW WILL LIKELY
HOLD DOWN HIGH TEMPERATURES MONDAY. THE GFS AND ECWMF MOS HAVE
TRENDED COOLER AND MAY STILL BE TOO WARM. STRONG NOCTURNAL COOLING
WITH THE RIDGE NEAR THE AREA SHOULD RESULT IN COLD LOW
TEMPERATURES WEDNESDAY THROUGH FRIDAY. THE GFS AND ECMWF MOS HAVE
LOWS IN THE UPPER 20S AND LOWER 30S.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
SURFACE RIDGE CONTINUES TO WEAKEN AS LOW PRESSURE DEVELOPS IN THE
MID MISSISSIPPI VALLEY. LOWER CLOUDS THAT BLANKETED THE AREA THIS
AFTERNOON HAVE SHIFTED TO THE WEST AND SOUTHWEST WITH VFR CONDITIONS
AT ALL BUT DNL WHERE THE LOW CLOUDS CONTINUE TO LINGER.
MOS GUIDANCE AND MODEL OUTPUT IS SUGGESTING THAT LOW CLOUDS WILL
RETURN TO THE TERMINALS LATER TONIGHT WHILE THE LATEST HRRR MODEL IS
KEEPING THE LOWER CLOUDS OFF TO THE SOUTHWEST. WILL FORECAST MVFR
CIGS TO RETURN NORTHWARD GIVEN THE SATURATED LOW LEVELS OF FORECAST
SOUNDINGS AND THE PERSISTENCE OF LOW CLOUDS FOR THE PAST SEVERAL
DAYS. SREF PROBABILITIES OF IFR CIGS ARE HIGH IN THE CSRA BY
08Z-10Z AND AT CAE/CUB AFTER 12Z BEFORE CIGS IMPROVE TO MVFR LATE
MORNING INTO EARLY AFTERNOON AS SOUTHERLY FLOW DEVELOPS AHEAD OF THE
APPROACHING COLD FRONT. CHANCES FOR SHOWERS WILL INCREASE DURING THE
AFTERNOON BUT CONFIDENCE IS LOW IN TERMINALS BEING IMPACTED BY THE
SHOWERS AT THIS TIME SO NOT INCLUDED IN THIS FORECAST.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY.
RESTRICTIONS POSSIBLE AGAIN LATE SUNDAY NIGHT AND MONDAY WITH
POSSIBLE WEDGE CONDITIONS DEVELOPING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
653 PM EST FRI DEC 5 2014
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE NORTH WILL
WEAKEN AHEAD OF THE APPROACHING COLD FRONT. THE FRONT WILL MOVE
THROUGH THE AREA SATURDAY EVENING. DRYING BEHIND THE FRONT WILL
DOMINATE SUNDAY BUT MOISTURE MAY SPREAD BACK INTO THE REGION
MONDAY ASSOCIATED WITH LOW PRESSURE DEVELOPING OFF THE COAST.
&&
.NEAR TERM /THROUGH SATURDAY/...
HIGH PRESSURE EXTENDING INTO THE FORECAST AREA FROM THE NORTH WILL
WEAKEN OVERNIGHT. HIGH LOW-LEVEL MOISTURE AND WEAK ISENTROPIC
LIFT PLUS NOCTURNAL COOLING SHOULD RESULT IN AREAS OF STRATUS AND
FOG. AT THIS TIME...NOT SURE HOW WIDESPREAD...BUT PLENTY OF
MID/HIGH CLOUDS MOVING ACROSS THE AREA. MOISTURE SHOULD REMAIN
SHALLOW FOR THE MOST PART LIMITING THE RAIN CHANCE...EXCEPT
MOISTURE MAY INCREASE LATE IN THE NORTHWEST SECTION ASSOCIATED
WITH A MID-LEVEL SHORTWAVE TROUGH. FORECASTED CHANCE POPS IN THE
NORTHWEST SECTION. CLOUDINESS SHOULD HELP HOLD UP TEMPERATURES.
THE MAV AND MET MOS WERE CLOSE WITH LOWS IN THE UPPER 40S TO
AROUND 50.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
MOISTURE WILL INCREASE AHEAD OF THE COLD FRONT SATURDAY. THE NAM
WAS STILL A LITTLE SLOWER COMPARED TO THE GFS WITH THE PLACEMENT
OF DEEPEST MOISTURE AHEAD OF THE FRONT. USED AN AVERAGE OF THE
GUIDANCE FOR THE TIMING OF HIGHEST POPS. STRONGER UPPER-LEVEL LIFT
AND DEEPER MOISTURE SUPPORTED THE HIGHEST POPS IN THE NORTH PART
OF THE FORECAST AREA. USED THE GUIDANCE CONSENSUS WITH CHANCE POPS
SOUTH AND LIKELY NORTH. A THUNDERSTORM IS NOT OUT OF THE QUESTION
BECAUSE OF COOLING ALOFT AHEAD OF THE SHORTWAVE TROUGH AND AN H5
DIFLUENT PATTERN PLUS LOW-LEVEL WARMING AHEAD OF THE FRONT.
HOWEVER...THE MODEL FORECAST SOUNDINGS HAD LITTLE CAPE AND
LIGHTNING WAS NOT EVIDENT UPSTREAM. BELIEVE THE THUNDERSTORM
CHANCE IS TOO LOW TO INCLUDE IN THE FORECAST AT THIS TIME. THE
TEMPERATURE GUIDANCE WAS CLOSE SATURDAY BUT MAY BE A LITTLE TOO
COOL JUST AHEAD OF THE COLD FRONT.
DRYING SHOULD OCCUR BEHIND THE FRONT SATURDAY NIGHT AND THE MODELS
HAVE BEEN CONSISTENT SHOWING DRY CONDITIONS CONTINUING SUNDAY. THE
PRESSURE GRADIENT BETWEEN THE RIDGE TO THE NORTHWEST AND OFFSHORE
FRONT WILL LIKELY RESULT IN BREEZY CONDITIONS SUNDAY. THE NAM MOS
HAD LESS WIND COMPARED TO THE GFS MOS. WE LEANED TOWARD MORE WIND
BASED ON THE EXPECTED GRADIENT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MODELS HAVE TRENDED BACK TO MORE MOISTURE MONDAY ASSOCIATED
WITH LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST. THIS MOISTURE
APPEARS DEEPEST IN THE NORTHEAST SECTION. THE GFS AND ECMWF MOS
POPS WERE NEAR 30 PERCENT. THE LOW SHOULD BE FARTHER NORTHEAST OF
THE AREA TUESDAY WITH DRY RIDGING DOMINATE DURING THE REST OF THE
MEDIUM-RANGE PERIOD. CLOUDINESS AND A NORTHEAST FLOW WILL LIKELY
HOLD DOWN HIGH TEMPERATURES MONDAY. THE GFS AND ECWMF MOS HAVE
TRENDED COOLER AND MAY STILL BE TOO WARM. STRONG NOCTURNAL COOLING
WITH THE RIDGE NEAR THE AREA SHOULD RESULT IN COLD LOW
TEMPERATURES WEDNESDAY THROUGH FRIDAY. THE GFS AND ECMWF MOS HAVE
LOWS IN THE UPPER 20S AND LOWER 30S.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SURFACE RIDGE CONTINUES TO WEAKEN AS LOW PRESSURE DEVELOPS IN THE
MID MISSISSIPPI VALLEY. LOWER CLOUDS THAT BLANKETED THE AREA THIS
AFTERNOON HAVE SHIFTED TO THE WEST AND SOUTHWEST WITH VFR CONDITIONS
AT ALL BUT DNL WHERE THE LOW CLOUDS CONTINUE TO LINGER.
MOS GUIDANCE AND MODEL OUTPUT IS SUGGESTING THAT LOW CLOUDS WILL
RETURN TO THE TERMINALS LATER TONIGHT WHILE THE LATEST HRRR MODEL IS
KEEPING THE LOWER CLOUDS OFF TO THE SOUTHWEST. WILL FORECAST MVFR
CIGS TO RETURN NORTHWARD GIVEN THE SATURATED LOW LEVELS OF FORECAST
SOUNDINGS AND THE PERSISTENCE OF LOW CLOUDS FOR THE PAST SEVERAL
DAYS. SREF PROBABILITIES OF IFR CIGS ARE HIGH IN THE CSRA BY
08Z-10Z AND AT CAE/CUB AFTER 12Z BEFORE CIGS IMPROVE TO MVFR LATE
MORNING INTO EARLY AFTERNOON AS SOUTHERLY FLOW DEVELOPS AHEAD OF THE
APPROACHING COLD FRONT. CHANCES FOR SHOWERS WILL INCREASE DURING THE
AFTERNOON BUT CONFIDENCE IS LOW IN TERMINALS BEING IMPACTED BY THE
SHOWERS AT THIS TIME SO NOT INCLUDED IN THIS FORECAST.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY.
RESTRICTIONS POSSIBLE AGAIN LATE SUNDAY NIGHT AND MONDAY WITH
POSSIBLE WEDGE CONDITIONS DEVELOPING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
625 AM EST THU DEC 4 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE THROUGH THE FORECAST AREA LATER THIS
MORNING. HIGH PRESSURE WILL RIDGE INTO THE AREA FROM THE NORTH
BEHIND THE FRONT LATER TODAY INTO FRIDAY. ANOTHER COLD FRONT WILL
APPROACH SATURDAY AND MOVE THROUGH THE AREA SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THIS MORNING...A WEAK COLD FRONT CURRENTLY MOVING THROUGH CENTRAL
NORTH CAROLINA WILL SINK SOUTH EARLY THIS MORNING AND PUSH
THROUGH THE AREA BY LATE MORNING. GIVEN LATEST OBS ACROSS THE
AREA EARLY THIS MORNING WITH VISIBILITIES AT OR BELOW ONE-QUARTER
OF A MILE...HAVE DECIDED TO ISSUE A DENSE FOG ADVISORY FOR THE
ENTIRE AREA UNTIL 9 AM THIS MORNING.
TODAY...WEAK COLD FRONT WILL PUSH THROUGH THE AREA WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT. MOISTURE REMAINS SHALLOW
WITH LITTLE IN THE WAY OF ISENTROPIC LIFT. DAYTIME HIGHS WILL
RANGE FROM AROUND 60 NORTH TO THE UPPER 60S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE NORTH
TONIGHT THROUGH FRIDAY. THE MODELS CONTINUE TO SHOW LITTLE
ISENTROPIC LIFT AND SHALLOW MOISTURE. HIGH PRESSURE WILL BUILD
INTO THE AREA LATER TODAY INTO FRIDAY. THE GUIDANCE CONSENSUS
SUPPORTS POPS LESS THAN 20 PERCENT THROUGH THE SHORT TERM. HIGH
LOW-LEVEL MOISTURE AND DIURNAL COOLING SHOULD LEAD TO AREAS OF
STRATUS AND FOG FRIDAY MORNING. LOWS TONIGHT WILL BE IN THE 40S.
HIGHS FRIDAY WILL RANGE FROM THE UPPER 50S NORTH TO THE LOWER 60S
SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NO CHANGES TO THE EXTENDED FORECAST. THE GFS AND ECMWF DISPLAY A
FRONTAL SYSTEM APPROACHING THE FORECAST AREA FRIDAY NIGHT AND
SATURDAY WITH THE SYSTEM MOVING THROUGH THE AREA SATURDAY NIGHT.
THE MODELS HAVE NOT BEEN CONSISTENT WITH THE PLACEMENT OF LOW
PRESSURE DEVELOPING ALONG THE FRONT AND THE EXTENT OF MOISTURE IN
THE FORECAST AREA...BUT GENERALLY HAVE INDICATED THE DEEPEST
MOISTURE DURING THE DAY SATURDAY. WE FORECASTED THE HIGHEST POPS
SATURDAY AND GENERALLY USED A BLEND OF THE GFS...ECMWF...AND EKD
MOS. THE RAIN CHANCE SHOULD DIMINISH SUNDAY...BUT CONFIDENCE IS
NOT HIGH BECAUSE PREVIOUS MODEL RUNS AND THE LATEST ECMWF HAVE
SHOWN CONTINUED HIGH WRAP-AROUND MOISTURE ASSOCIATED WITH AN
OFFSHORE LOW. THE 12Z GFS WAS MORE PROGRESSIVE AND HAD DRY RIDGING
DOMINATING SUNDAY. CONFIDENCE REMAINS LOW DURING THE REST OF THE
MEDIUM-RANGE PERIOD. THE 12Z GFS HAD CONSIDERABLE MOISTURE AND
ISENTROPIC LIFT MONDAY WITH A DRY PATTERN DURING THE REST OF THE
PERIOD. THE 00Z WEDNESDAY ECMWF HAD A MID-LEVEL CUT-OFF LOW NEAR
THE FORECAST AREA TUESDAY AND WEDNESDAY. THE GFS ENSEMBLE HAD A
HIGH SPREAD DURING THE PERIOD.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
LIFR/IFR CONDITIONS EARLY THIS MORNING DUE TO WIDESPREAD FOG.
WEAK SURFACE HIGH PRESSURE OVER THE CAROLINAS AND GEORGIA WILL
GRADUALLY WEAKEN AS A WEAK SLOW MOVING FRONT BACK DOORS THROUGH
THE AREA THIS MORNING. DESPITE HIGH CLOUDINESS...WIDESPREAD FOG
ACROSS THE AREA THIS MORNING RESULTING IN LIFR/LIFR. EXCEPTION IS
DNL WHERE CONDITIONS VFR AT THE MOMENT...BUT POSSIBLE FOG
DEVELOPMENT AFTER 12Z. LATEST HRRR GUIDANCE SUGGEST VISIBILITY MAY
IMPROVE AFTER 14Z BUT LINGERING MVFR CONDITIONS THROUGH 17Z AT
MOST TERMINALS UNTIL WEAK FRONT MOVES THROUGH AND NORTHEAST WINDS
DEVELOP. VFR THROUGH THE AFTERNOON AND EARLY EVENING WITH STRATO-CU
AND HIGH CLOUDS. NORTHEAST OR EAST WINDS MAINLY LESS THAN 10 KTS.
HIGH LOW-LEVEL MOISTURE TONIGHT AND DRY AIR ALOFT MAY RESULT IN
FOG AND OR STRATUS DEVELOPMENT AGAIN...MVFR FORECAST BUT LIFR/IFR POSSIBLE.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE AT TIMES MAINLY AT
NIGHT OR EARLY MORNING DUE TO FOG OR STRATUS THROUGH SATURDAY.
SHOWER ACTIVITY POSSIBLE SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ030.
GA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR GAZ040-
063>065-077.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
ISSUED BY NATIONAL WEATHER SERVICE LINCOLN IL
1203 PM CST THU DEC 4 2014
.SHORT TERM...
211 AM CST
THROUGH FRIDAY NIGHT...
IR IMAGERY EARLY THIS MORNING SHOWS CONSIDERABLE MID/UPR LEVEL
CLOUDS OVER THE REGION...ASSOCIATED WITH A WEAK MID-LVL VORT. THIS
FEATURE IS RATHER WEAK...BUT SOME ASCENT WITHIN THE MOIST COLUMN
IS PROBABLE AND COULD BE JUST ENOUGH TO PRODUCE SOME FLURRIES
ACROSS SOUTHERN WISC/FAR NORTHERN IL JUST AFT DAYBREAK THRU NOON
BEFORE ENDING. TEMPS AHEAD OF THIS FEATURE HAVE REMAINED IN THE
LOW/MID 20S...THANKS IN PART TO THE THICK CLOUD COVER INHIBITING
COOLING. THE NEAR SFC ENVIRONMENT REMAINS DRY...WITH DEW POINTS
STILL IN THE LOW/MID TEENS. SO ANY PRECIP THAT CAN DEVELOP WOULD
REMAIN VERY LIGHT AND CONFINED TO THE FAR NORTHERN PORTIONS OF THE
FORECAST AREA.
ANTI-CYCLONIC FLOW WILL STEADILY DEPART TO THE NORTHEAST...WITH LLVL
FLOW TURNING EAST/SOUTHEAST ALONG THE BACK EDGE OF THE SFC RIDGE.
LLVLS WILL REMAIN RATHER DRY...WITH DEW PTS LIKELY HOLDING IN THE
UPR TEENS TO LOW 20S. THEN LATER THIS AFTN/EVE THE SOUTHERN STREAM
SYSTEM WILL BEGIN TO ADVECT NORTH...AND BASED ON LATEST WV
IMAGERY...LLVL MOISTURE SHUD START TO ADVECT INTO THE SOUTHERN
PORTIONS OF THE FORECAST AREA. THIS WILL LIKELY KEEP CONSIDERABLE
SOLAR SHIELDING IN PLACE...HOWEVER WITH THE 850MB THERMAL TROUGH
SLOWLY DEPARTING TO THE NORTHEAST THIS AFTN...SFC TEMPS SHUD STILL
PUSH INTO THE LOW/MID 30S.
MID-LVL FLOW REMAIN FLAT TONIGHT...AS MUCH OF THE CONUS TRANSITIONS
INTO A SEMI-ZONAL PATTERN. THIS WILL ALLOW THE SOUTHERN STREAM MOIST
CONVEYOR TO ADVECT NORTH INTO THE MISSOURI VALLEY...WITH GUIDANCE
INDICATING LGT QPF REACHING THE SOUTHERN CWFA JUST AFT MIDNIGHT.
UNFORTUNATELY THERMAL PROFILES INDICATE A WARM WEDGE ABOVE THE SFC
THAT WOULD ALLOW FULL MELT OF ANY DENDRITES...AND SUPPORT PRECIP
FALLING AS LGT FZRA. DROPLET SIZE COULD BE SMALL...AND WITH THE LACK
OF STRONG ASCENT OVERNIGHT...SO IT IS PLAUSIBLE THAT PRECIP COULD
END UP BEING FREEZING DRIZZLE. THE FOCUS WILL BE SOUTH OF I-80
BEFORE DAYBREAK FRI. HI-RES LOCAL SOLUTION ALONG WITH THE NAM
INDICATE A WEAK MID-LVL WAVE RIDING NORTHEAST FROM THE CENTRAL
PLAINS FRI MORNING...WHICH COULD PUSH THE PRECIP SHIELD FURTHER
NORTH JUST AFT DAYBREAK. AS A RESULT OF THIS HAVE INCLUDED A MENTION
OF PATCHY FREEZING DRIZZLE ACROSS THE NORTHERN PORTIONS OF THE CWFA
FRI MORNING. THEN AS THE MORNING PROGRESSES TEMPS SHUD WARM AT THE
SFC TO CHANGE ALL PRECIP OVER TO LIQUID FORM...BUT AGAIN REMAIN
FOCUSED ALONG AND SOUTH OF I-80.
THE MID-LVL WAVE WILL QUICKLY PIVOT EAST...WITH ANTI-CYCLONIC FLOW
DROPPING SOUTHEAST FROM CENTRAL CANADA INTO THE UPPER MIDWEST FRI
AFTN. THIS WILL HELP TO KICK THE BETTER MOISTURE SHIELD EAST FRI
NGT...AND SLOWLY BRING DRY AIR BACK INTO THE NORTHWEST CWFA FRI EVE.
TEMPS FRI WILL EVENTUALLY PUSH INTO THE UPR 30S/ARND 40 FOR THE
NORTH CWFA...AND POSSIBLY TOUCH THE LOW 40S IN THE FAR SOUTHERN CWFA
FRI AFTN.
BEACHLER
&&
.LONG TERM...
211 AM CST
SATURDAY THROUGH MIDDLE NEXT WEEK...
FOR THE FIRST HALF OF THE WEEKEND ENSEMBLES ARE DEMONSTRATING
MINIMAL SPREAD WITH RESPECT TO THE 500MB HEIGHTS...SUGGESTING
RIDGING WILL BE IN PLACE ACROSS THE ROCKIES WITH WEAK TROUGHING
DEPARTING TO THE NORTHEAST ACROSS ONTARIO/QUEBEC. WITH SOME
AMPLIFICATION TO THE UPSTREAM RIDGE OVER THE ROCKIES...A WEAK
TROUGH IS PROGGED TO DEVELOP AND SLIDE SOUTHEAST ACROSS THE GREAT
LAKES EARLY NEXT WEEK...BUT THEN THE RIDGE STARTS TO FLATTEN AND
KICKS THE TROUGH EAST WITH A SEMI- ZONAL PATTERN CLOSER TO THE
MIDDLE OF NEXT WEEK. THE WEEKEND CURRENTLY LOOKS TO REMAIN
DRY...HOWEVER WITH THE ARRIVAL OF THE AFOREMENTIONED TROUGH AT THE
START OF NEXT WEEK...LGT PRECIP IS POSSIBLE MON/MON NGT. THEN SFC
RIDGING IS POISED TO RETURN FOR TUE/WED WITH DRY WEATHER. TEMPS
FOR THE WEEKEND INTO EARLY NEXT WEEK LOOK TO REMAIN RATHER
UNIFORM...OR GENERALLY IN THE UPR 30S/ARND 40.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WINDS 10 KT OR LESS SHIFTING FROM ENE TO SE LATE MORNING/EARLY
AFTERNOON CONTINUING THROUGH FRIDAY MORNING.
* CIGS LOWERING TO MVFR TONIGHT AND A MIX OF IFR AND LOW END MVFR BY
FRIDAY MORNING.
* LIGHT RAIN POSSIBLE BY FRIDAY AFTERNOON.
MB/DJO
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE IS MOVING OFF TO THE ENE OF THE CHICAGO CWA CAUSING
LIGHT WINDS TO VEER AROUND TOWARD SOUTHEASTERLY LATE THIS MORNING.
WIND SPEEDS THROUGHOUT THE PERIOD ARE EXPECTED TO BE 10 KTS OR
LESS...WITH THE HIGHEST WIND SPEEDS REACHING 8-10 KTS IN THE
AFTERNOON HOURS. GRADUALLY LOWERING CEILINGS ARE EXPECTED THROUGH
THE DAY...REACHING MVFR CATEGORY IN THE EARLY MORNING HOURS FRIDAY.
AS THE LOWER CEILINGS ARRIVE...A BRIEF PERIOD OF -FZDZ REMAINS
POSSIBLE IN THE AREA...HOWEVER THE PROBABILITY OF PRECIPITATION
LOOKS TOO LOW AT THIS TIME FOR MENTION IN THE CHICAGO AREA TAFS. BY
LATE MORNING THROUGH AFTERNOON...CEILINGS SHOULD GENERALLY REACH IFR
CATEGORY WITH LIGHT FOG. A BETTER CHANCE FOR RAIN WILL ALSO ARRIVE
AS THICKER CLOUD COVER ALOFT ARRIVES IN THE AREA.
MB/DJO
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH CONFIDENCE IN WIND DETAILS.
* HIGH CONFIDENCE IN CIGS LOWERING TO MVFR/IFR TONIGHT/TOMORROW.
* MEDIUM CONFIDENCE IN -RA OCCURRING FRIDAY AFTERNOON.
MB/DJO
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF RAIN. MVFR/IFR POSSIBLE.
NE WINDS BECOMING N.
SATURDAY...MVFR CIGS PSBL EARLY...OTHERWISE VFR. N WINDS BECOMING
NE.
SUNDAY...MAINLY VFR. CHANCE OF LGT SLEET/SNOW AND MVFR SUNDAY
NIGHT. E WINDS BECOMING SE.
MONDAY...CHANCE OF RAIN OR SNOW. MVFR/BRIEF IFR POSSIBLE. SSW
WINDS BECOMING NW.
TUESDAY...MAINLY VFR. N WINDS BECOMING NE.
WEDNESDAY...VFR. S WINDS.
MDB
&&
.MARINE...
247 AM CST
HIGH PRESSURE WILL CROSS LAKE MICHIGAN TODAY ALLOWING THE GUSTY WEST
TO NORTHWEST WINDS ACROSS NORTHERN SECTIONS OF THE LAKE TO DIMINISH
AND BECOME SOUTHERLY. WINDS FURTHER SOUTH WILL TAKE ON A MORE
EASTERLY DIRECTION BEFORE BECOMING SOUTHEAST THIS AFTERNOON...WITH A
MORE UNIFORM SOUTH TO SOUTHEAST DIRECTION ACROSS THE LAKE INTO
TONIGHT. LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY
MORNING AND TRACK ACROSS THE OHIO VALLEY FRIDAY NIGHT. AS THIS
OCCURS...STRONG HIGH PRESSURE WILL MOVE INTO THE NORTHERN PLAINS AND
UPPER MISSISSIPPI RIVER VALLEY AND ACROSS THE UPPER LAKES SATURDAY
AND SATURDAY NIGHT. WINDS WILL TURN MORE VARIABLE LATER FRIDAY AS
A WEAKNESS IN THE GRADIENT DEVELOPS BETWEEN THE LOW AND THE HIGH BUT
A BRISK NORTH WIND WILL DEVELOP AS THE GRADIENT BECOMES ESTABLISHED
FRIDAY NIGHT. WINDS WILL TURN NORTHEASTERLY SATURDAY MORNING AND
DIMINISH INTO SATURDAY EVENING AS THE HIGH MOVES ACROSS. WINDS WILL
WORK AROUND TO THE EAST THEN SOUTHEAST LATER SUNDAY AS LOW PRESSURE
TRACKS ALONG THE U.S./CANADIAN BORDER. HAVE SEEN SOME VARIATION ON
THE TRACK OF THIS LOW BUT THERE IS BETTER AGREEMENT ON IT TRACKING
NORTH OF THE LAKE MONDAY. SOUTHEAST WINDS WILL INCREASE AHEAD OF THE
LOW SUNDAY NIGHT THEN TURN SOUTHWESTERLY THEN NORTHWESTERLY AS A
COOL FRONT PASSES LATER MONDAY. ANOTHER AREA OF HIGH PRESSURE WILL
MOVE ACROSS THE LAKE TUESDAY WITH THE TRACK OF SUBSEQUENT LOW
PRESSURE LIKELY SETTING UP ACROSS SOUTHERN CANADA. THIS WILL
KEEP A PREDOMINANTLY SOUTHERLY FLOW ACROSS THE LAKE THROUGH THE
REST OF NEXT WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1133 AM CST Thu Dec 4 2014
.UPDATE...
ISSUED AT 953 AM CST THU DEC 4 2014
Area of precipitation continues to push across locations east of
I-55 late this morning. Surface reports as of 945 am mainly
showing the areas south of I-70 as rain. Mixture occurring just
north of here, with mainly snow and some snow/ice pellets as far
north as a Lincoln to Danville line. Temperatures in that area
creeping upward and this should become more rain with time before
diminishing early afternoon. Latest RAP suggests perhaps a bit of
drizzle reforming across the southwest CWA early in the afternoon
as well.
Have sent some updated zones to reflect the precip types this
morning and adjust some of the PoP`s into tonight as well. Some
minor adjustments also needed for the temperature trends.
&&
.SHORT TERM...(Today through Saturday)
ISSUED AT 330 AM CST THU DEC 4 2014
1031 mb Canadian high pressure over WI and northern IL has been
providing dry weather so far over central/SE IL though blanket of
mid/high clouds now covers much of the region. Temps range from
mid 20s far NE counties to the lower 30s from Jacksonville to
Robinson SW. Weak short wave affecting IL today and will develop
light precipitation over mainly southern half of CWA today. Radar
mosaic shows several echos over central and southern IL but most
of these are currently virga and precipitation not reaching the
ground due to very dry atmosphere per 00Z ILX/DVN soundings. Have
chances of light freezing rain and sleet developing from I-72
south during this morning and changing to lift rain later this
morning and afternoon. Areas north of Lincoln generally dry today
though fairly cloudy there as well. Highs today in mid to upper
30s with Lawrenceville near 40F.
Have lingering chances of light rain over eastern/SE IL this
evening and then rain chances to increase from the south overnight
as storm system in the SW U.S. approaches the central/southern plains.
Light freezing rain possible north of Lincoln overnight but precip
here is very light perhaps from a trace to a few hundredths. Have
best chances of rain developing during Friday and Fri night
especially in southeast IL where moderate rainfall expected. Rain
to diminish from NW to SE during overnight Fri night and Sat morning
with totals of 1-1.5 inches in southeast IL while near a tenth
inch north of Peoria over Knox, Stark and Marshall counties.
&&
.LONG TERM...(Saturday night through Thursday) ISSUED AT 330 AM CST
THU DEC 4 2014
Strong Canadian high pressure to settle into southeast Canada
Sunday and ridge SW into IL providing dry and seasonably cool
conditions. Ridge drifts east of IL Sunday evening while a
northern stream short wave/upper level low translates across the
northern plains into the upper Great Lakes by Monday morning. This
to bring isolated chances of light rain/snow showers later Sunday
night and Monday, then shifting east into IN by overnight Monday night
and Tue. Surface ridge to drift east over IL Tue night and Wed
returning dry weather. Highs in the upper 30s and lower 40s
expected Mon-Wed. Temperatures then expected to moderate by next
Thu and Fri as upper level ridge builds into IL.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1133 AM CST THU DEC 4 2014
Band of snow showers that reduced visibility at KCMI recently has
lifted northeast, and much of the precipitation this afternoon
should not affect the TAF sites. However, some MVFR and IFR
ceilings loom across southern Illinois and are lifting north, and
should be spreading into central Illinois toward mid afternoon.
General trend will be for widespread ceilings below 1000 feet by
mid evening, and the TAFs will have these persisting the
remainder of the forecast period. Visibility should lower some as
some light drizzle and fog begins to develop, with more steady
light rain spreading into the area after 12Z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...07
LONG TERM...07
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1014 AM CST THU DEC 4 2014
.SHORT TERM...
211 AM CST
THROUGH FRIDAY NIGHT...
IR IMAGERY EARLY THIS MORNING SHOWS CONSIDERABLE MID/UPR LEVEL
CLOUDS OVER THE REGION...ASSOCIATED WITH A WEAK MID-LVL VORT. THIS
FEATURE IS RATHER WEAK...BUT SOME ASCENT WITHIN THE MOIST COLUMN
IS PROBABLE AND COULD BE JUST ENOUGH TO PRODUCE SOME FLURRIES
ACROSS SOUTHERN WISC/FAR NORTHERN IL JUST AFT DAYBREAK THRU NOON
BEFORE ENDING. TEMPS AHEAD OF THIS FEATURE HAVE REMAINED IN THE
LOW/MID 20S...THANKS IN PART TO THE THICK CLOUD COVER INHIBITING
COOLING. THE NEAR SFC ENVIRONMENT REMAINS DRY...WITH DEW POINTS
STILL IN THE LOW/MID TEENS. SO ANY PRECIP THAT CAN DEVELOP WOULD
REMAIN VERY LIGHT AND CONFINED TO THE FAR NORTHERN PORTIONS OF THE
FORECAST AREA.
ANTI-CYCLONIC FLOW WILL STEADILY DEPART TO THE NORTHEAST...WITH LLVL
FLOW TURNING EAST/SOUTHEAST ALONG THE BACK EDGE OF THE SFC RIDGE.
LLVLS WILL REMAIN RATHER DRY...WITH DEW PTS LIKELY HOLDING IN THE
UPR TEENS TO LOW 20S. THEN LATER THIS AFTN/EVE THE SOUTHERN STREAM
SYSTEM WILL BEGIN TO ADVECT NORTH...AND BASED ON LATEST WV
IMAGERY...LLVL MOISTURE SHUD START TO ADVECT INTO THE SOUTHERN
PORTIONS OF THE FORECAST AREA. THIS WILL LIKELY KEEP CONSIDERABLE
SOLAR SHIELDING IN PLACE...HOWEVER WITH THE 850MB THERMAL TROUGH
SLOWLY DEPARTING TO THE NORTHEAST THIS AFTN...SFC TEMPS SHUD STILL
PUSH INTO THE LOW/MID 30S.
MID-LVL FLOW REMAIN FLAT TONIGHT...AS MUCH OF THE CONUS TRANSITIONS
INTO A SEMI-ZONAL PATTERN. THIS WILL ALLOW THE SOUTHERN STREAM MOIST
CONVEYOR TO ADVECT NORTH INTO THE MISSOURI VALLEY...WITH GUIDANCE
INDICATING LGT QPF REACHING THE SOUTHERN CWFA JUST AFT MIDNIGHT.
UNFORTUNATELY THERMAL PROFILES INDICATE A WARM WEDGE ABOVE THE SFC
THAT WOULD ALLOW FULL MELT OF ANY DENDRITES...AND SUPPORT PRECIP
FALLING AS LGT FZRA. DROPLET SIZE COULD BE SMALL...AND WITH THE LACK
OF STRONG ASCENT OVERNIGHT...SO IT IS PLAUSIBLE THAT PRECIP COULD
END UP BEING FREEZING DRIZZLE. THE FOCUS WILL BE SOUTH OF I-80
BEFORE DAYBREAK FRI. HI-RES LOCAL SOLUTION ALONG WITH THE NAM
INDICATE A WEAK MID-LVL WAVE RIDING NORTHEAST FROM THE CENTRAL
PLAINS FRI MORNING...WHICH COULD PUSH THE PRECIP SHIELD FURTHER
NORTH JUST AFT DAYBREAK. AS A RESULT OF THIS HAVE INCLUDED A MENTION
OF PATCHY FREEZING DRIZZLE ACROSS THE NORTHERN PORTIONS OF THE CWFA
FRI MORNING. THEN AS THE MORNING PROGRESSES TEMPS SHUD WARM AT THE
SFC TO CHANGE ALL PRECIP OVER TO LIQUID FORM...BUT AGAIN REMAIN
FOCUSED ALONG AND SOUTH OF I-80.
THE MID-LVL WAVE WILL QUICKLY PIVOT EAST...WITH ANTI-CYCLONIC FLOW
DROPPING SOUTHEAST FROM CENTRAL CANADA INTO THE UPPER MIDWEST FRI
AFTN. THIS WILL HELP TO KICK THE BETTER MOISTURE SHIELD EAST FRI
NGT...AND SLOWLY BRING DRY AIR BACK INTO THE NORTHWEST CWFA FRI EVE.
TEMPS FRI WILL EVENTUALLY PUSH INTO THE UPR 30S/ARND 40 FOR THE
NORTH CWFA...AND POSSIBLY TOUCH THE LOW 40S IN THE FAR SOUTHERN CWFA
FRI AFTN.
BEACHLER
&&
.LONG TERM...
211 AM CST
SATURDAY THROUGH MIDDLE NEXT WEEK...
FOR THE FIRST HALF OF THE WEEKEND ENSEMBLES ARE DEMONSTRATING
MINIMAL SPREAD WITH RESPECT TO THE 500MB HEIGHTS...SUGGESTING
RIDGING WILL BE IN PLACE ACROSS THE ROCKIES WITH WEAK TROUGHING
DEPARTING TO THE NORTHEAST ACROSS ONTARIO/QUEBEC. WITH SOME
AMPLIFICATION TO THE UPSTREAM RIDGE OVER THE ROCKIES...A WEAK
TROUGH IS PROGGED TO DEVELOP AND SLIDE SOUTHEAST ACROSS THE GREAT
LAKES EARLY NEXT WEEK...BUT THEN THE RIDGE STARTS TO FLATTEN AND
KICKS THE TROUGH EAST WITH A SEMI- ZONAL PATTERN CLOSER TO THE
MIDDLE OF NEXT WEEK. THE WEEKEND CURRENTLY LOOKS TO REMAIN
DRY...HOWEVER WITH THE ARRIVAL OF THE AFOREMENTIONED TROUGH AT THE
START OF NEXT WEEK...LGT PRECIP IS POSSIBLE MON/MON NGT. THEN SFC
RIDGING IS POISED TO RETURN FOR TUE/WED WITH DRY WEATHER. TEMPS
FOR THE WEEKEND INTO EARLY NEXT WEEK LOOK TO REMAIN RATHER
UNIFORM...OR GENERALLY IN THE UPR 30S/ARND 40.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* WINDS 10 KT OR LESS SHIFTING FROM ENE TO SE LATE MORNING/EARLY
AFTERNOON CONTINUING THROUGH FRIDAY MORNING.
* CIGS LOWERING TO MVFR TONIGHT AND LOW END MVFR BY FRIDAY
MORNING.
* CHANCE FOR A PERIOD OF -FZDZ EARLY FRIDAY MORNING.
MB/DJO
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE IS PASSING OVER THE TERMINALS THIS MORNING. WINDS
ARE STARTING TO SHOW A STEADIER NORTHEAST DIRECTION AND WILL
CONTINUE TO SWING AROUND TO EAST-SOUTHEAST THROUGH LATE MORNING.
EXPECT SPEEDS OF 10 KT OR LESS...THOUGH A FEW 11-12 KT SPEEDS
COULD OCCUR FOR A TIME THIS AFTERNOON BUT LOOK TO BE INFREQUENT IF
THEY DO OCCUR. A PASSING UPPER TROUGH WILL KEEP MID LEVEL CLOUD
COVER IN PLACE WITH SOME LOWERING OF BASES THROUGH THE MORNING.
OTHERWISE CEILINGS WILL LOWER TONIGHT...LIKELY REACHING MVFR
DURING THE EARLY OVERNIGHT...AS LOW PRESSURE MOVES TOWARD THE OHIO
VALLEY. CIGS MAY LOWER NEAR IFR LEVELS FRIDAY MORNING. THE LOW
CLOUDS WILL ALSO BRING A CHANCE FOR SOME -FZDZ FRIDAY MORNING WITH
TEMPERATURES WARMING ABOVE FREEZING INTO LATE MORNING.
PRECIPITATION THIS FAR NORTH SHOULD BE VERY LIGHT IF IT DOES
OCCUR.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH CONFIDENCE IN WIND DETAILS.
* HIGH CONFIDENCE IN CIGS LOWERING TO MVFR TONIGHT.
* MEDIUM CONFIDENCE IN -FZDZ OCCURRING FRIDAY MORNING.
MB/DJO
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF RAIN. MVFR/IFR POSSIBLE.
NE WINDS BECOMING N.
SATURDAY...MVFR CIGS PSBL EARLY...OTHERWISE VFR. N WINDS BECOMING
NE.
SUNDAY...MAINLY VFR. CHANCE OF LGT SLEET/SNOW AND MVFR SUNDAY
NIGHT. E WINDS BECOMING SE.
MONDAY...CHANCE OF RAIN OR SNOW. MVFR/BRIEF IFR POSSIBLE. SSW
WINDS BECOMING NW.
TUESDAY...MAINLY VFR. N WINDS BECOMING NE.
WEDNESDAY...VFR. S WINDS.
MDB
&&
.MARINE...
247 AM CST
HIGH PRESSURE WILL CROSS LAKE MICHIGAN TODAY ALLOWING THE GUSTY WEST
TO NORTHWEST WINDS ACROSS NORTHERN SECTIONS OF THE LAKE TO DIMINISH
AND BECOME SOUTHERLY. WINDS FURTHER SOUTH WILL TAKE ON A MORE
EASTERLY DIRECTION BEFORE BECOMING SOUTHEAST THIS AFTERNOON...WITH A
MORE UNIFORM SOUTH TO SOUTHEAST DIRECTION ACROSS THE LAKE INTO
TONIGHT. LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY
MORNING AND TRACK ACROSS THE OHIO VALLEY FRIDAY NIGHT. AS THIS
OCCURS...STRONG HIGH PRESSURE WILL MOVE INTO THE NORTHERN PLAINS AND
UPPER MISSISSIPPI RIVER VALLEY AND ACROSS THE UPPER LAKES SATURDAY
AND SATURDAY NIGHT. WINDS WILL TURN MORE VARIABLE LATER FRIDAY AS
A WEAKNESS IN THE GRADIENT DEVELOPS BETWEEN THE LOW AND THE HIGH BUT
A BRISK NORTH WIND WILL DEVELOP AS THE GRADIENT BECOMES ESTABLISHED
FRIDAY NIGHT. WINDS WILL TURN NORTHEASTERLY SATURDAY MORNING AND
DIMINISH INTO SATURDAY EVENING AS THE HIGH MOVES ACROSS. WINDS WILL
WORK AROUND TO THE EAST THEN SOUTHEAST LATER SUNDAY AS LOW PRESSURE
TRACKS ALONG THE U.S./CANADIAN BORDER. HAVE SEEN SOME VARIATION ON
THE TRACK OF THIS LOW BUT THERE IS BETTER AGREEMENT ON IT TRACKING
NORTH OF THE LAKE MONDAY. SOUTHEAST WINDS WILL INCREASE AHEAD OF THE
LOW SUNDAY NIGHT THEN TURN SOUTHWESTERLY THEN NORTHWESTERLY AS A
COOL FRONT PASSES LATER MONDAY. ANOTHER AREA OF HIGH PRESSURE WILL
MOVE ACROSS THE LAKE TUESDAY WITH THE TRACK OF SUBSEQUENT LOW
PRESSURE LIKELY SETTING UP ACROSS SOUTHERN CANADA. THIS WILL
KEEP A PREDOMINANTLY SOUTHERLY FLOW ACROSS THE LAKE THROUGH THE
REST OF NEXT WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
953 AM CST Thu Dec 4 2014
.UPDATE...
ISSUED AT 953 AM CST THU DEC 4 2014
Area of precipitation continues to push across locations east of
I-55 late this morning. Surface reports as of 945 am mainly
showing the areas south of I-70 as rain. Mixture occurring just
north of here, with mainly snow and some snow/ice pellets as far
north as a Lincoln to Danville line. Temperatures in that area
creeping upward and this should become more rain with time before
diminishing early afternoon. Latest RAP suggests perhaps a bit of
drizzle reforming across the southwest CWA early in the afternoon
as well.
Have sent some updated zones to reflect the precip types this
morning and adjust some of the PoP`s into tonight as well. Some
minor adjustments also needed for the temperature trends.
&&
.SHORT TERM...(Today through Saturday)
ISSUED AT 330 AM CST THU DEC 4 2014
1031 mb Canadian high pressure over WI and northern IL has been
providing dry weather so far over central/se IL though blanket of
mid/high clouds now covers much of the region. Temps range from
mid 20s far ne counties to the lower 30s from Jacksonville to
Robinson sw. Weak short wave affecting IL today and will develop
light precipitation over mainly southern half of CWA today. Radar
mosaic shows several echos over central and southern IL but most
of these are currently virga and precipitation not reaching the
ground due to very dry atmosphere per 00Z ILX/DVN soundings. Have
chances of light freezing rain and sleet developing from I-72
south during this morning and changing to lift rain later this
morning and afternoon. Areas north of Lincoln generally dry today
though fairly cloudy there as well. Highs today in mid to upper
30s with Lawrenceville near 40F.
Have lingering chances of light rain over eastern/se IL this
evening and then rain chances to increase from the south overnight
as storm system in the sw U.S. approaches the central/southern plains.
Light freezing rain possible north of Lincoln overnight but precip
here is very light perhaps from a trace to a few hundredths. Have
best chances of rain developing during Friday and Fri night
especially in southeast IL where moderate rainfall expected. Rain
to diminish from nw to se during overnight Fri night and Sat morning
with totals of 1-1.5 inches in southeast IL while near a tenth
inch north of Peoria over Knox, Stark and Marshall counties.
&&
.LONG TERM...(Saturday night through Thursday) ISSUED AT 330 AM CST
THU DEC 4 2014
Strong Canadian high pressure to settle into southeast Canada
Sunday and ridge sw into IL providing dry and seasonably cool
conditions. Ridge drifts east of IL Sunday evening while a
northern stream short wave/upper level low translates across the
northern plains into the upper Great Lakes by Monday morning. This
to bring isolated chances of light rain/snow showers later Sunday
night and Monday, then shifting east into IN by overnight Monday night
and Tue. Surface ridge to drift east over IL Tue night and Wed
returning dry weather. Highs in the upper 30s and lower 40s
expected Mon-Wed. Temperatures then expected to moderate by next
Thu and Fri as upper level ridge builds into IL.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 558 AM CST THU DEC 4 2014
VFR conditions will begin at all sites this morning. Conditions
will decrease to MVFR around noon at SPI/DEC/CMI and then in the
late afternoon at PIA and BMI. Returns on radar are probably just
mid clouds or Virga since the lower levels are very dry,
temp/dewpoint spreads are around 10F at some places, and surface
reports of pcpn have been hard to come by. However, by later this
morning as the lower levels moisten up slowly, there could be some
light pcpn occurring at SPI/DEC/CMI so will have a VCSH at those
three sites. PIA and BMI will remain dry this morning and into
this afternoon. SPI/DEC/CMI will see a break in the pcpn this
afternoon, but MVFR cigs are expected. By around 03z this evening
vis and cigs will decrease, but remain in the MVFR range. With the
lower vis, drizzle will be possible too. Conditions will fall into
the IFR category around midnight at SPI/DEC/CMI with cigs below
1kft and vis around 2sm. Drizzle will also continue into the
overnight hours. Temps should be warm enough at this sites that
any pcpn overnight will be liquid. PIA and BMI will also see
conditions decrease into IFR, but after midnight. Pcpn should stay south
of these two sites, but a slight chance is still there for
freezing rain/drizzle, given temps below freezing tonight.
However, for now will not add in TAFs, but would not be surprised
to see it added later today.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...07
LONG TERM...07
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1030 PM EST FRI DEC 5 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST FRI DEC 5 2014
WIDESPREAD RAIN WILL CONTINUE THROUGH SATURDAY MORNING AS LOW
PRESSURE TRACKS THROUGH THE OHIO VALLEY. WITH THE EXCEPTION OF A FEW
SHOWERS MONDAY AS LOW PRESSURE PASSES THROUGH THE GREAT LAKES...DRY
AND SEASONABLY COOL WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 953 PM EST FRI DEC 5 2014
FORECAST IS IN GOOD SHAPE AND MADE NO MAJOR CHANGES. RAIN WILL
CONTINUE ACROSS THE AREA AS LOW PRESSURE MOVES SOUTH OF CENTRAL
INDIANA AND AN UPPER TROUGH MOVES INTO THE AREA. LATER TONIGHT AS
FORCING SHIFTS EAST...RAIN WILL DIMINISH SOME FROM NORTHWEST TO
SOUTHEAST. WARM AIR WILL REMAIN JUST SOUTH OF THE AREA.
PREVIOUS DISCUSSION FOLLOWS...
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON...AND EXPECT
ONLY TO INCREASE FURTHER IN INTENSITY OVER THE NEXT SEVERAL HOURS
WITH THE APPROACH OF LOW PRESSURE. TEMPS RANGED FROM THE UPPER 30S
NORTH TO UPPER 40S ACROSS FAR SOUTHERN COUNTIES AT 20Z.
A RAW WET NIGHT UPCOMING AS LOW PRESSURE CURRENTLY OVER THE OZARKS
TRACKS E/NE ALONG THE OHIO RIVER TONIGHT. MODEL GUIDANCE IN
EXCELLENT AGREEMENT ON SPREADING ANOTHER WAVE OF HEAVIER CONVECTIVE
RAINFALL INTO THE FORECAST AREA LATE THIS AFTERNOON THROUGH THE
EVENING. FOCUS FOR THE HEAVIEST RAINS REMAINS ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA BETWEEN 00-06Z AS STRONGER LOW LEVEL
CONVERGENCE ALIGNS ALONG THE 850MB BAROCLINIC ZONE AND AREA OF
ENHANCED ISENTROPIC LIFT. A LOW LEVEL JET OVER THE TENNESSEE VALLEY
WILL TRANSPORT DEEPER MOISTURE UP INTO THE REGION AS WELL. APPROACH
OF THE UPPER WAVE WILL PROMOTE DIFFLUENCE ALOFT...FURTHER ASSISTING
LIFT FOR EFFICIENT RAINFALL.
THERE IS SOME WEAK ELEVATED INSTABILITY PRESENT...BUT JUST DO NOT
SEE ENOUGH TO JUSTIFY AN ISOLATED THUNDER MENTION TONIGHT. BETTER
THREAT FOR A FEW STORMS WILL EXIST CLOSER TO THE SURFACE LOW TRACK
ALONG THE OHIO RIVER. POTENTIAL EXISTS FOR UP TO 1.5 INCHES ALONG
AND SOUTH OF I-70 BY SATURDAY MORNING. WILL CONTINUE WITH
CATEGORICAL POPS TONIGHT. HEAVIER RAINS WILL BEGIN TO SHIFT EAST
AFTER 06Z...BUT LINGERING MID LEVEL DEFORMATION BAND WILL MAINTAIN
LIGHTER RAIN FOR MUCH OF THE REST OF THE NIGHT. HRRR AND WRF-NMM/ARW
BRING BACK END OF THE RAIN INTO THE NORTHERN WABASH VALLEY AROUND OR
SHORTLY BEFORE DAYBREAK. WINDS WILL PICK UP LATE TONIGHT AS WELL AS
A BRISK NORTHERLY FLOW DEVELOPS BEHIND THE SURFACE LOW.
TEMPS...MOS APPEARS A BIT AGGRESSIVE IN BRINGING THE COLDER AIR IN
PRIOR TO 12Z. GENERALLY TRENDED A DEGREE OR TWO ABOVE MAVMOS
GUIDANCE WITH LOWS RANGING FROM THE MID 30S NORTH TO LOWER 40S
SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
FORECAST CHALLENGES FOCUS ON THE DEPARTURE OF THE RAIN SATURDAY
MORNING...AND POSSIBILITY FOR LIGHT PRECIP WITH A WEAK SYSTEM ON
MONDAY.
THE UPPER WAVE AND SURFACE LOW WILL CONTINUE TO MOVE AWAY TO THE
EAST WITH LIGHT RAIN ENDING FROM NORTHWEST TO SOUTHEAST DURING THE
MORNING. WRF DATA LOOKS VERY GOOD WITH RESPECT TO TIMING AND WAS
UTILIZED FOR MORNING POPS. EXPECT THE ENTIRE FORECAST AREA WILL BE
FREE OF PRECIP AROUND MIDDAY. DRIER AIR ALOFT WILL QUICKLY ADVECT
INTO THE REGION WITH STRONG HIGH PRESSURE SATURDAY AFTERNOON...BUT
RH PROGS AND MODEL SOUNDINGS INDICATE LINGERING LOW LEVEL MOISTURE
REMAINING TRAPPED BENEATH A SLOWLY WEAKENING INVERSION. EXPECT LOWER
CLOUDS TO LINGER AS A RESULT...WITH FULL CLEARING OF THE CLOUD DECK
NOT COMING UNTIL SATURDAY EVENING AS STRONGER SUBSIDENCE ENABLES
DRIER AIR TO INFILTRATE THE NEAR SURFACE LAYER.
HIGH PRESSURE RIDGE WILL DRIFT SLOWLY THROUGH THE GREAT LAKES
SATURDAY NIGHT AND SUNDAY...PROVIDING A DRY COOL E/NE FLOW ACROSS
CENTRAL INDIANA. EXPECT ABUNDANT SUNSHINE ON SUNDAY...WHICH
AMAZINGLY WOULD BE THE FIRST DAY WITH EXTENDED SUNSHINE AND BLUE
SKIES FOR MANY SINCE NOVEMBER 21.
MID AND HIGH LEVEL CLOUDS WILL INCREASE AGAIN BEGINNING SUNDAY NIGHT
WITH SKIES BECOMING FAIRLY CLOUDY MONDAY AS AN UPPER WAVE AND
ASSOCIATED LOW PRESSURE ASSOCIATED WITH THE NORTHERN JET STREAM
TRACK INTO THE GREAT LAKES. DESPITE INCREASING ISENTROPIC LIFT AND
HINT OF SOME DEVELOPING LOW LEVEL CONVERGENCE...MOISTURE PROFILES
LARGELY LOOK UNIMPRESSIVE AND FOCUSED PRIMARILY ABOVE 10KFT. HAVE A
HARD TIME JUSTIFYING MUCH HIGHER THAN LOW CHANCE POPS AS THE SYSTEM
PASSES THROUGH. ENOUGH COLD AIR PRESENT THAT MAY SEE A MIXTURE OF
LIGHT SNOW AND RAIN IN THE NORTHERN WABASH VALLEY MONDAY MORNING
BEFORE PRECIP TRANSITIONS TO ALL RAIN. REGARDLESS...QPF VALUES AT
THIS POINT LOOK NO HIGHER THAN A FEW HUNDREDTHS.
TEMPS...LEANED CLOSER TO COOLER METMOS FOR SATURDAY HIGHS WITH THE
LINGER LOW CLOUDS. WENT NEAR MOS FOR SUNDAY THEN UNDERCUT FOR MONDAY
AND LEANED CLOSER TO ECMWF ENSEMBLE MEAN TEMPS. DESPITE WARM
ADVECTION AHEAD OF THE SURFACE LOW...MEXMOS LOOKS TOO AGGRESSIVE
WITH WARMING TEMPS. LEANED TOWARDS WARMER METMOS FOR SATURDAY NIGHT
LOWS AND TOOK A MODEL BLEND FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
ENSEMBLES INDICATE A FAIRLY STRONG UPPER TROUGH THAT IS EXPECTED TO
DROP SOUTHEAST ACROSS THE GREAT LAKES MONDAY NIGHT INTO TUESDAY. A
FEW OF THE ENSEMBLES SUGGEST THERE MAY A SOME LIGHT RAIN OR SNOW
SHOWERS DURING THIS PERIOD AS THE TROUGH BRUSHES BY...BUT NOT ENOUGH
OF A SIGNAL TO PUT IN THE FORECAST AT THIS TIME. WILL MONITOR THE
TRENDS.
OTHERWISE...SOME OF THE ENSEMBLES CUTOFF THE SOUTHERN PART OF THE
EARLY WEEK TROUGH OVER THE EASTERN PARTS OF THE COUNTRY LATER NEXT
WEEK...WHILE OTHERS ARE MORE PROGRESSIVE. DOESN/T APPEAR EITHER
SOLUTION WILL RESULT IN MUCH OF A PRECIPITATION THREAT OVER THE
AREA...BUT IF THE LESS PROGRESSIVE SOLUTIONS END UP BEING
CORRECT...THE WARMUP LATE NEXT WEEK MAY BE TEMPERED SOME.
&&
.AVIATION /DISCUSSION FOR THE 060600Z TAF ISSUANCE/...
ISSUED AT 1030 PM EST FRI DEC 5 2014
IFR AND WORSE CONDITIONS EXPECTED TO BE THE MOST PREVALENT FLIGHT
CATEGORIES THROUGH THE NIGHT.
RADAR TRENDS AND 02Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT WITH MOSTLY A LIGHT INTENSITY
BEFORE ENDING AFTER 09Z AT LAF...11Z AT HUF...12Z AT IND AND 13Z AT
BMG. SHOULD SEE CONDITIONS IMPROVE TO MVFR AFTER 12Z FROM NORTHWEST
TO SOUTHEAST. DO NOT EXPECT MUCH CLEARING OVERNIGHT SATURDAY
NIGHT...BUT COULD SEE A FEW BREAKS.
WINDS WILL BE BRIEFLY EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS. SPEED AND DIRECTION SHOULD BE SIMILAR DURING THE
DAY AND BECOME NORTHEAST 10 KNOTS OR LESS AFTER 00Z TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/50
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
953 PM EST FRI DEC 5 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST FRI DEC 5 2014
WIDESPREAD RAIN WILL CONTINUE THROUGH SATURDAY MORNING AS LOW
PRESSURE TRACKS THROUGH THE OHIO VALLEY. WITH THE EXCEPTION OF A FEW
SHOWERS MONDAY AS LOW PRESSURE PASSES THROUGH THE GREAT LAKES...DRY
AND SEASONABLY COOL WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 953 PM EST FRI DEC 5 2014
FORECAST IS IN GOOD SHAPE AND MADE NO MAJOR CHANGES. RAIN WILL
CONTINUE ACROSS THE AREA AS LOW PRESSURE MOVES SOUTH OF CENTRAL
INDIANA AND AN UPPER TROUGH MOVES INTO THE AREA. LATER TONIGHT AS
FORCING SHIFTS EAST...RAIN WILL DIMINISH SOME FROM NORTHWEST TO
SOUTHEAST. WARM AIR WILL REMAIN JUST SOUTH OF THE AREA.
PREVIOUS DISCUSSION FOLLOWS...
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON...AND EXPECT
ONLY TO INCREASE FURTHER IN INTENSITY OVER THE NEXT SEVERAL HOURS
WITH THE APPROACH OF LOW PRESSURE. TEMPS RANGED FROM THE UPPER 30S
NORTH TO UPPER 40S ACROSS FAR SOUTHERN COUNTIES AT 20Z.
A RAW WET NIGHT UPCOMING AS LOW PRESSURE CURRENTLY OVER THE OZARKS
TRACKS E/NE ALONG THE OHIO RIVER TONIGHT. MODEL GUIDANCE IN
EXCELLENT AGREEMENT ON SPREADING ANOTHER WAVE OF HEAVIER CONVECTIVE
RAINFALL INTO THE FORECAST AREA LATE THIS AFTERNOON THROUGH THE
EVENING. FOCUS FOR THE HEAVIEST RAINS REMAINS ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA BETWEEN 00-06Z AS STRONGER LOW LEVEL
CONVERGENCE ALIGNS ALONG THE 850MB BAROCLINIC ZONE AND AREA OF
ENHANCED ISENTROPIC LIFT. A LOW LEVEL JET OVER THE TENNESSEE VALLEY
WILL TRANSPORT DEEPER MOISTURE UP INTO THE REGION AS WELL. APPROACH
OF THE UPPER WAVE WILL PROMOTE DIFFLUENCE ALOFT...FURTHER ASSISTING
LIFT FOR EFFICIENT RAINFALL.
THERE IS SOME WEAK ELEVATED INSTABILITY PRESENT...BUT JUST DO NOT
SEE ENOUGH TO JUSTIFY AN ISOLATED THUNDER MENTION TONIGHT. BETTER
THREAT FOR A FEW STORMS WILL EXIST CLOSER TO THE SURFACE LOW TRACK
ALONG THE OHIO RIVER. POTENTIAL EXISTS FOR UP TO 1.5 INCHES ALONG
AND SOUTH OF I-70 BY SATURDAY MORNING. WILL CONTINUE WITH
CATEGORICAL POPS TONIGHT. HEAVIER RAINS WILL BEGIN TO SHIFT EAST
AFTER 06Z...BUT LINGERING MID LEVEL DEFORMATION BAND WILL MAINTAIN
LIGHTER RAIN FOR MUCH OF THE REST OF THE NIGHT. HRRR AND WRF-NMM/ARW
BRING BACK END OF THE RAIN INTO THE NORTHERN WABASH VALLEY AROUND OR
SHORTLY BEFORE DAYBREAK. WINDS WILL PICK UP LATE TONIGHT AS WELL AS
A BRISK NORTHERLY FLOW DEVELOPS BEHIND THE SURFACE LOW.
TEMPS...MOS APPEARS A BIT AGGRESSIVE IN BRINGING THE COLDER AIR IN
PRIOR TO 12Z. GENERALLY TRENDED A DEGREE OR TWO ABOVE MAVMOS
GUIDANCE WITH LOWS RANGING FROM THE MID 30S NORTH TO LOWER 40S
SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
FORECAST CHALLENGES FOCUS ON THE DEPARTURE OF THE RAIN SATURDAY
MORNING...AND POSSIBILITY FOR LIGHT PRECIP WITH A WEAK SYSTEM ON
MONDAY.
THE UPPER WAVE AND SURFACE LOW WILL CONTINUE TO MOVE AWAY TO THE
EAST WITH LIGHT RAIN ENDING FROM NORTHWEST TO SOUTHEAST DURING THE
MORNING. WRF DATA LOOKS VERY GOOD WITH RESPECT TO TIMING AND WAS
UTILIZED FOR MORNING POPS. EXPECT THE ENTIRE FORECAST AREA WILL BE
FREE OF PRECIP AROUND MIDDAY. DRIER AIR ALOFT WILL QUICKLY ADVECT
INTO THE REGION WITH STRONG HIGH PRESSURE SATURDAY AFTERNOON...BUT
RH PROGS AND MODEL SOUNDINGS INDICATE LINGERING LOW LEVEL MOISTURE
REMAINING TRAPPED BENEATH A SLOWLY WEAKENING INVERSION. EXPECT LOWER
CLOUDS TO LINGER AS A RESULT...WITH FULL CLEARING OF THE CLOUD DECK
NOT COMING UNTIL SATURDAY EVENING AS STRONGER SUBSIDENCE ENABLES
DRIER AIR TO INFILTRATE THE NEAR SURFACE LAYER.
HIGH PRESSURE RIDGE WILL DRIFT SLOWLY THROUGH THE GREAT LAKES
SATURDAY NIGHT AND SUNDAY...PROVIDING A DRY COOL E/NE FLOW ACROSS
CENTRAL INDIANA. EXPECT ABUNDANT SUNSHINE ON SUNDAY...WHICH
AMAZINGLY WOULD BE THE FIRST DAY WITH EXTENDED SUNSHINE AND BLUE
SKIES FOR MANY SINCE NOVEMBER 21.
MID AND HIGH LEVEL CLOUDS WILL INCREASE AGAIN BEGINNING SUNDAY NIGHT
WITH SKIES BECOMING FAIRLY CLOUDY MONDAY AS AN UPPER WAVE AND
ASSOCIATED LOW PRESSURE ASSOCIATED WITH THE NORTHERN JET STREAM
TRACK INTO THE GREAT LAKES. DESPITE INCREASING ISENTROPIC LIFT AND
HINT OF SOME DEVELOPING LOW LEVEL CONVERGENCE...MOISTURE PROFILES
LARGELY LOOK UNIMPRESSIVE AND FOCUSED PRIMARILY ABOVE 10KFT. HAVE A
HARD TIME JUSTIFYING MUCH HIGHER THAN LOW CHANCE POPS AS THE SYSTEM
PASSES THROUGH. ENOUGH COLD AIR PRESENT THAT MAY SEE A MIXTURE OF
LIGHT SNOW AND RAIN IN THE NORTHERN WABASH VALLEY MONDAY MORNING
BEFORE PRECIP TRANSITIONS TO ALL RAIN. REGARDLESS...QPF VALUES AT
THIS POINT LOOK NO HIGHER THAN A FEW HUNDREDTHS.
TEMPS...LEANED CLOSER TO COOLER METMOS FOR SATURDAY HIGHS WITH THE
LINGER LOW CLOUDS. WENT NEAR MOS FOR SUNDAY THEN UNDERCUT FOR MONDAY
AND LEANED CLOSER TO ECMWF ENSEMBLE MEAN TEMPS. DESPITE WARM
ADVECTION AHEAD OF THE SURFACE LOW...MEXMOS LOOKS TOO AGGRESSIVE
WITH WARMING TEMPS. LEANED TOWARDS WARMER METMOS FOR SATURDAY NIGHT
LOWS AND TOOK A MODEL BLEND FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
ENSEMBLES INDICATE A FAIRLY STRONG UPPER TROUGH THAT IS EXPECTED TO
DROP SOUTHEAST ACROSS THE GREAT LAKES MONDAY NIGHT INTO TUESDAY. A
FEW OF THE ENSEMBLES SUGGEST THERE MAY A SOME LIGHT RAIN OR SNOW
SHOWERS DURING THIS PERIOD AS THE TROUGH BRUSHES BY...BUT NOT ENOUGH
OF A SIGNAL TO PUT IN THE FORECAST AT THIS TIME. WILL MONITOR THE
TRENDS.
OTHERWISE...SOME OF THE ENSEMBLES CUTOFF THE SOUTHERN PART OF THE
EARLY WEEK TROUGH OVER THE EASTERN PARTS OF THE COUNTRY LATER NEXT
WEEK...WHILE OTHERS ARE MORE PROGRESSIVE. DOESN/T APPEAR EITHER
SOLUTION WILL RESULT IN MUCH OF A PRECIPITATION THREAT OVER THE
AREA...BUT IF THE LESS PROGRESSIVE SOLUTIONS END UP BEING
CORRECT...THE WARMUP LATE NEXT WEEK MAY BE TEMPERED SOME.
&&
.AVIATION /DISCUSSION FOR THE 060300Z IND TAF UPDATE/...
ISSUED AT 920 PM EST FRI DEC 5 2014
WENT WITH MVFR AND TEMPO IFR CONDITIONS IN MODERATE RAIN THROUGH 04Z
BASED ON TRENDS. OTHERWISE...NO CHANGES.
PREVIOUS DISCUSSION FOLLOWS...
IFR AND WORSE CONDITIONS EXPECTED THROUGH THE NIGHT.
RADAR TRENDS AND 21Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT BEFORE ENDING AFTER 09Z AT
LAF...11Z AT HUF...12Z AT IND AND 13Z AT BMG. THE RAIN COULD BE
MODERATE TO HEAVY AT TIMES THROUGH THE EVENING AS LOW LEVEL JET
MIGRATES EASTWARD ACROSS KENTUCKY. HOWEVER...LAF LOOKS TO BE APT TO
EXPERIENCE A MORE CONSTANT LIGHT RAIN. CEILINGS AND VISIBILITIES ARE
EXPECTED TO BE IFR OR WORSE THROUGH THE NIGHT WITH LIFR THE MOST
LIKELY CATEGORY FOR THE MAJORITY OF THE NIGHT. THEN...SHOULD SEE
CONDITIONS IMPROVE TO IFR AND MVFR AFTER 12Z...EXCEPT A LITTLE
EARLIER AT LAF.
WINDS WILL START OFF EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/50
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
920 PM EST FRI DEC 5 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST FRI DEC 5 2014
WIDESPREAD RAIN WILL CONTINUE THROUGH SATURDAY MORNING AS LOW
PRESSURE TRACKS THROUGH THE OHIO VALLEY. WITH THE EXCEPTION OF A FEW
SHOWERS MONDAY AS LOW PRESSURE PASSES THROUGH THE GREAT LAKES...DRY
AND SEASONABLY COOL WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 347 PM EST FRI DEC 5 2014
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON...AND EXPECT
ONLY TO INCREASE FURTHER IN INTENSITY OVER THE NEXT SEVERAL HOURS
WITH THE APPROACH OF LOW PRESSURE. TEMPS RANGED FROM THE UPPER 30S
NORTH TO UPPER 40S ACROSS FAR SOUTHERN COUNTIES AT 20Z.
A RAW WET NIGHT UPCOMING AS LOW PRESSURE CURRENTLY OVER THE OZARKS
TRACKS E/NE ALONG THE OHIO RIVER TONIGHT. MODEL GUIDANCE IN
EXCELLENT AGREEMENT ON SPREADING ANOTHER WAVE OF HEAVIER CONVECTIVE
RAINFALL INTO THE FORECAST AREA LATE THIS AFTERNOON THROUGH THE
EVENING. FOCUS FOR THE HEAVIEST RAINS REMAINS ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA BETWEEN 00-06Z AS STRONGER LOW LEVEL
CONVERGENCE ALIGNS ALONG THE 850MB BAROCLINIC ZONE AND AREA OF
ENHANCED ISENTROPIC LIFT. A LOW LEVEL JET OVER THE TENNESSEE VALLEY
WILL TRANSPORT DEEPER MOISTURE UP INTO THE REGION AS WELL. APPROACH
OF THE UPPER WAVE WILL PROMOTE DIFFLUENCE ALOFT...FURTHER ASSISTING
LIFT FOR EFFICIENT RAINFALL.
THERE IS SOME WEAK ELEVATED INSTABILITY PRESENT...BUT JUST DO NOT
SEE ENOUGH TO JUSTIFY AN ISOLATED THUNDER MENTION TONIGHT. BETTER
THREAT FOR A FEW STORMS WILL EXIST CLOSER TO THE SURFACE LOW TRACK
ALONG THE OHIO RIVER. POTENTIAL EXISTS FOR UP TO 1.5 INCHES ALONG
AND SOUTH OF I-70 BY SATURDAY MORNING. WILL CONTINUE WITH
CATEGORICAL POPS TONIGHT. HEAVIER RAINS WILL BEGIN TO SHIFT EAST
AFTER 06Z...BUT LINGERING MID LEVEL DEFORMATION BAND WILL MAINTAIN
LIGHTER RAIN FOR MUCH OF THE REST OF THE NIGHT. HRRR AND WRF-NMM/ARW
BRING BACK END OF THE RAIN INTO THE NORTHERN WABASH VALLEY AROUND OR
SHORTLY BEFORE DAYBREAK. WINDS WILL PICK UP LATE TONIGHT AS WELL AS
A BRISK NORTHERLY FLOW DEVELOPS BEHIND THE SURFACE LOW.
TEMPS...MOS APPEARS A BIT AGGRESSIVE IN BRINGING THE COLDER AIR IN
PRIOR TO 12Z. GENERALLY TRENDED A DEGREE OR TWO ABOVE MAVMOS
GUIDANCE WITH LOWS RANGING FROM THE MID 30S NORTH TO LOWER 40S
SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
FORECAST CHALLENGES FOCUS ON THE DEPARTURE OF THE RAIN SATURDAY
MORNING...AND POSSIBILITY FOR LIGHT PRECIP WITH A WEAK SYSTEM ON
MONDAY.
THE UPPER WAVE AND SURFACE LOW WILL CONTINUE TO MOVE AWAY TO THE
EAST WITH LIGHT RAIN ENDING FROM NORTHWEST TO SOUTHEAST DURING THE
MORNING. WRF DATA LOOKS VERY GOOD WITH RESPECT TO TIMING AND WAS
UTILIZED FOR MORNING POPS. EXPECT THE ENTIRE FORECAST AREA WILL BE
FREE OF PRECIP AROUND MIDDAY. DRIER AIR ALOFT WILL QUICKLY ADVECT
INTO THE REGION WITH STRONG HIGH PRESSURE SATURDAY AFTERNOON...BUT
RH PROGS AND MODEL SOUNDINGS INDICATE LINGERING LOW LEVEL MOISTURE
REMAINING TRAPPED BENEATH A SLOWLY WEAKENING INVERSION. EXPECT LOWER
CLOUDS TO LINGER AS A RESULT...WITH FULL CLEARING OF THE CLOUD DECK
NOT COMING UNTIL SATURDAY EVENING AS STRONGER SUBSIDENCE ENABLES
DRIER AIR TO INFILTRATE THE NEAR SURFACE LAYER.
HIGH PRESSURE RIDGE WILL DRIFT SLOWLY THROUGH THE GREAT LAKES
SATURDAY NIGHT AND SUNDAY...PROVIDING A DRY COOL E/NE FLOW ACROSS
CENTRAL INDIANA. EXPECT ABUNDANT SUNSHINE ON SUNDAY...WHICH
AMAZINGLY WOULD BE THE FIRST DAY WITH EXTENDED SUNSHINE AND BLUE
SKIES FOR MANY SINCE NOVEMBER 21.
MID AND HIGH LEVEL CLOUDS WILL INCREASE AGAIN BEGINNING SUNDAY NIGHT
WITH SKIES BECOMING FAIRLY CLOUDY MONDAY AS AN UPPER WAVE AND
ASSOCIATED LOW PRESSURE ASSOCIATED WITH THE NORTHERN JET STREAM
TRACK INTO THE GREAT LAKES. DESPITE INCREASING ISENTROPIC LIFT AND
HINT OF SOME DEVELOPING LOW LEVEL CONVERGENCE...MOISTURE PROFILES
LARGELY LOOK UNIMPRESSIVE AND FOCUSED PRIMARILY ABOVE 10KFT. HAVE A
HARD TIME JUSTIFYING MUCH HIGHER THAN LOW CHANCE POPS AS THE SYSTEM
PASSES THROUGH. ENOUGH COLD AIR PRESENT THAT MAY SEE A MIXTURE OF
LIGHT SNOW AND RAIN IN THE NORTHERN WABASH VALLEY MONDAY MORNING
BEFORE PRECIP TRANSITIONS TO ALL RAIN. REGARDLESS...QPF VALUES AT
THIS POINT LOOK NO HIGHER THAN A FEW HUNDREDTHS.
TEMPS...LEANED CLOSER TO COOLER METMOS FOR SATURDAY HIGHS WITH THE
LINGER LOW CLOUDS. WENT NEAR MOS FOR SUNDAY THEN UNDERCUT FOR MONDAY
AND LEANED CLOSER TO ECMWF ENSEMBLE MEAN TEMPS. DESPITE WARM
ADVECTION AHEAD OF THE SURFACE LOW...MEXMOS LOOKS TOO AGGRESSIVE
WITH WARMING TEMPS. LEANED TOWARDS WARMER METMOS FOR SATURDAY NIGHT
LOWS AND TOOK A MODEL BLEND FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
ENSEMBLES INDICATE A FAIRLY STRONG UPPER TROUGH THAT IS EXPECTED TO
DROP SOUTHEAST ACROSS THE GREAT LAKES MONDAY NIGHT INTO TUESDAY. A
FEW OF THE ENSEMBLES SUGGEST THERE MAY A SOME LIGHT RAIN OR SNOW
SHOWERS DURING THIS PERIOD AS THE TROUGH BRUSHES BY...BUT NOT ENOUGH
OF A SIGNAL TO PUT IN THE FORECAST AT THIS TIME. WILL MONITOR THE
TRENDS.
OTHERWISE...SOME OF THE ENSEMBLES CUTOFF THE SOUTHERN PART OF THE
EARLY WEEK TROUGH OVER THE EASTERN PARTS OF THE COUNTRY LATER NEXT
WEEK...WHILE OTHERS ARE MORE PROGRESSIVE. DOESN/T APPEAR EITHER
SOLUTION WILL RESULT IN MUCH OF A PRECIPITATION THREAT OVER THE
AREA...BUT IF THE LESS PROGRESSIVE SOLUTIONS END UP BEING
CORRECT...THE WARMUP LATE NEXT WEEK MAY BE TEMPERED SOME.
&&
.AVIATION /DISCUSSION FOR THE 060300Z IND TAF UPDATE/...
ISSUED AT 920 PM EST FRI DEC 5 2014
WENT WITH MVFR AND TEMPO IFR CONDITIONS IN MODERATE RAIN THROUGH 04Z
BASED ON TRENDS. OTHERWISE...NO CHANGES.
PREVIOUS DISCUSSION FOLLOWS...
IFR AND WORSE CONDITIONS EXPECTED THROUGH THE NIGHT.
RADAR TRENDS AND 21Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT BEFORE ENDING AFTER 09Z AT
LAF...11Z AT HUF...12Z AT IND AND 13Z AT BMG. THE RAIN COULD BE
MODERATE TO HEAVY AT TIMES THROUGH THE EVENING AS LOW LEVEL JET
MIGRATES EASTWARD ACROSS KENTUCKY. HOWEVER...LAF LOOKS TO BE APT TO
EXPERIENCE A MORE CONSTANT LIGHT RAIN. CEILINGS AND VISIBILITIES ARE
EXPECTED TO BE IFR OR WORSE THROUGH THE NIGHT WITH LIFR THE MOST
LIKELY CATEGORY FOR THE MAJORITY OF THE NIGHT. THEN...SHOULD SEE
CONDITIONS IMPROVE TO IFR AND MVFR AFTER 12Z...EXCEPT A LITTLE
EARLIER AT LAF.
WINDS WILL START OFF EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
607 PM EST FRI DEC 5 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST FRI DEC 5 2014
WIDESPREAD RAIN WILL CONTINUE THROUGH SATURDAY MORNING AS LOW
PRESSURE TRACKS THROUGH THE OHIO VALLEY. WITH THE EXCEPTION OF A FEW
SHOWERS MONDAY AS LOW PRESSURE PASSES THROUGH THE GREAT LAKES...DRY
AND SEASONABLY COOL WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 347 PM EST FRI DEC 5 2014
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON...AND EXPECT
ONLY TO INCREASE FURTHER IN INTENSITY OVER THE NEXT SEVERAL HOURS
WITH THE APPROACH OF LOW PRESSURE. TEMPS RANGED FROM THE UPPER 30S
NORTH TO UPPER 40S ACROSS FAR SOUTHERN COUNTIES AT 20Z.
A RAW WET NIGHT UPCOMING AS LOW PRESSURE CURRENTLY OVER THE OZARKS
TRACKS E/NE ALONG THE OHIO RIVER TONIGHT. MODEL GUIDANCE IN
EXCELLENT AGREEMENT ON SPREADING ANOTHER WAVE OF HEAVIER CONVECTIVE
RAINFALL INTO THE FORECAST AREA LATE THIS AFTERNOON THROUGH THE
EVENING. FOCUS FOR THE HEAVIEST RAINS REMAINS ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA BETWEEN 00-06Z AS STRONGER LOW LEVEL
CONVERGENCE ALIGNS ALONG THE 850MB BAROCLINIC ZONE AND AREA OF
ENHANCED ISENTROPIC LIFT. A LOW LEVEL JET OVER THE TENNESSEE VALLEY
WILL TRANSPORT DEEPER MOISTURE UP INTO THE REGION AS WELL. APPROACH
OF THE UPPER WAVE WILL PROMOTE DIFFLUENCE ALOFT...FURTHER ASSISTING
LIFT FOR EFFICIENT RAINFALL.
THERE IS SOME WEAK ELEVATED INSTABILITY PRESENT...BUT JUST DO NOT
SEE ENOUGH TO JUSTIFY AN ISOLATED THUNDER MENTION TONIGHT. BETTER
THREAT FOR A FEW STORMS WILL EXIST CLOSER TO THE SURFACE LOW TRACK
ALONG THE OHIO RIVER. POTENTIAL EXISTS FOR UP TO 1.5 INCHES ALONG
AND SOUTH OF I-70 BY SATURDAY MORNING. WILL CONTINUE WITH
CATEGORICAL POPS TONIGHT. HEAVIER RAINS WILL BEGIN TO SHIFT EAST
AFTER 06Z...BUT LINGERING MID LEVEL DEFORMATION BAND WILL MAINTAIN
LIGHTER RAIN FOR MUCH OF THE REST OF THE NIGHT. HRRR AND WRF-NMM/ARW
BRING BACK END OF THE RAIN INTO THE NORTHERN WABASH VALLEY AROUND OR
SHORTLY BEFORE DAYBREAK. WINDS WILL PICK UP LATE TONIGHT AS WELL AS
A BRISK NORTHERLY FLOW DEVELOPS BEHIND THE SURFACE LOW.
TEMPS...MOS APPEARS A BIT AGGRESSIVE IN BRINGING THE COLDER AIR IN
PRIOR TO 12Z. GENERALLY TRENDED A DEGREE OR TWO ABOVE MAVMOS
GUIDANCE WITH LOWS RANGING FROM THE MID 30S NORTH TO LOWER 40S
SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
FORECAST CHALLENGES FOCUS ON THE DEPARTURE OF THE RAIN SATURDAY
MORNING...AND POSSIBILITY FOR LIGHT PRECIP WITH A WEAK SYSTEM ON
MONDAY.
THE UPPER WAVE AND SURFACE LOW WILL CONTINUE TO MOVE AWAY TO THE
EAST WITH LIGHT RAIN ENDING FROM NORTHWEST TO SOUTHEAST DURING THE
MORNING. WRF DATA LOOKS VERY GOOD WITH RESPECT TO TIMING AND WAS
UTILIZED FOR MORNING POPS. EXPECT THE ENTIRE FORECAST AREA WILL BE
FREE OF PRECIP AROUND MIDDAY. DRIER AIR ALOFT WILL QUICKLY ADVECT
INTO THE REGION WITH STRONG HIGH PRESSURE SATURDAY AFTERNOON...BUT
RH PROGS AND MODEL SOUNDINGS INDICATE LINGERING LOW LEVEL MOISTURE
REMAINING TRAPPED BENEATH A SLOWLY WEAKENING INVERSION. EXPECT LOWER
CLOUDS TO LINGER AS A RESULT...WITH FULL CLEARING OF THE CLOUD DECK
NOT COMING UNTIL SATURDAY EVENING AS STRONGER SUBSIDENCE ENABLES
DRIER AIR TO INFILTRATE THE NEAR SURFACE LAYER.
HIGH PRESSURE RIDGE WILL DRIFT SLOWLY THROUGH THE GREAT LAKES
SATURDAY NIGHT AND SUNDAY...PROVIDING A DRY COOL E/NE FLOW ACROSS
CENTRAL INDIANA. EXPECT ABUNDANT SUNSHINE ON SUNDAY...WHICH
AMAZINGLY WOULD BE THE FIRST DAY WITH EXTENDED SUNSHINE AND BLUE
SKIES FOR MANY SINCE NOVEMBER 21.
MID AND HIGH LEVEL CLOUDS WILL INCREASE AGAIN BEGINNING SUNDAY NIGHT
WITH SKIES BECOMING FAIRLY CLOUDY MONDAY AS AN UPPER WAVE AND
ASSOCIATED LOW PRESSURE ASSOCIATED WITH THE NORTHERN JET STREAM
TRACK INTO THE GREAT LAKES. DESPITE INCREASING ISENTROPIC LIFT AND
HINT OF SOME DEVELOPING LOW LEVEL CONVERGENCE...MOISTURE PROFILES
LARGELY LOOK UNIMPRESSIVE AND FOCUSED PRIMARILY ABOVE 10KFT. HAVE A
HARD TIME JUSTIFYING MUCH HIGHER THAN LOW CHANCE POPS AS THE SYSTEM
PASSES THROUGH. ENOUGH COLD AIR PRESENT THAT MAY SEE A MIXTURE OF
LIGHT SNOW AND RAIN IN THE NORTHERN WABASH VALLEY MONDAY MORNING
BEFORE PRECIP TRANSITIONS TO ALL RAIN. REGARDLESS...QPF VALUES AT
THIS POINT LOOK NO HIGHER THAN A FEW HUNDREDTHS.
TEMPS...LEANED CLOSER TO COOLER METMOS FOR SATURDAY HIGHS WITH THE
LINGER LOW CLOUDS. WENT NEAR MOS FOR SUNDAY THEN UNDERCUT FOR MONDAY
AND LEANED CLOSER TO ECMWF ENSEMBLE MEAN TEMPS. DESPITE WARM
ADVECTION AHEAD OF THE SURFACE LOW...MEXMOS LOOKS TOO AGGRESSIVE
WITH WARMING TEMPS. LEANED TOWARDS WARMER METMOS FOR SATURDAY NIGHT
LOWS AND TOOK A MODEL BLEND FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
ENSEMBLES INDICATE A FAIRLY STRONG UPPER TROUGH THAT IS EXPECTED TO
DROP SOUTHEAST ACROSS THE GREAT LAKES MONDAY NIGHT INTO TUESDAY. A
FEW OF THE ENSEMBLES SUGGEST THERE MAY A SOME LIGHT RAIN OR SNOW
SHOWERS DURING THIS PERIOD AS THE TROUGH BRUSHES BY...BUT NOT ENOUGH
OF A SIGNAL TO PUT IN THE FORECAST AT THIS TIME. WILL MONITOR THE
TRENDS.
OTHERWISE...SOME OF THE ENSEMBLES CUTOFF THE SOUTHERN PART OF THE
EARLY WEEK TROUGH OVER THE EASTERN PARTS OF THE COUNTRY LATER NEXT
WEEK...WHILE OTHERS ARE MORE PROGRESSIVE. DOESN/T APPEAR EITHER
SOLUTION WILL RESULT IN MUCH OF A PRECIPITATION THREAT OVER THE
AREA...BUT IF THE LESS PROGRESSIVE SOLUTIONS END UP BEING
CORRECT...THE WARMUP LATE NEXT WEEK MAY BE TEMPERED SOME.
&&
.AVIATION /DISCUSSION FOR THE 060000Z TAF ISSUANCE/...
ISSUED AT 607 PM EST FRI DEC 5 2014
IFR AND WORSE CONDITIONS EXPECTED THROUGH THE NIGHT.
RADAR TRENDS AND 21Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT BEFORE ENDING AFTER 09Z AT
LAF...11Z AT HUF...12Z AT IND AND 13Z AT BMG. THE RAIN COULD BE
MODERATE TO HEAVY AT TIMES THROUGH THE EVENING AS LOW LEVEL JET
MIGRATES EASTWARD ACROSS KENTUCKY. HOWEVER...LAF LOOKS TO BE APT TO
EXPERIENCE A MORE CONSTANT LIGHT RAIN. CEILINGS AND VISIBILITIES ARE
EXPECTED TO BE IFR OR WORSE THROUGH THE NIGHT WITH LIFR THE MOST
LIKELY CATEGORY FOR THE MAJORITY OF THE NIGHT. THEN...SHOULD SEE
CONDITIONS IMPROVE TO IFR AND MVFR AFTER 12Z...EXCEPT A LITTLE
EARLIER AT LAF.
WINDS WILL START OFF EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1146 AM EST THU DEC 4 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 950 AM EST THU DEC 4 2014
AN UPPER WAVE AND MOISTENING SOUTHWEST UPGLIDE WILL BRING MIXED
PRECIPITATION TO CENTRAL INDIANA THROUGH EARLY AFTERNOON BEFORE THE
PRECIPITATION CHANGES TO RAIN. MEANWHILE...A FRONTAL SYSTEM ACROSS
THE GULF STATES WILL GRADUALLY LIFT NORTHEAST AND ACROSS CENTRAL
INDIANA EARLY THIS WEEKEND. THIS WILL BRING RAIN TO THE AREA...AS
WELL AS COUPLE OF BRIEF CHANCES FOR SOME LIGHT FREEZING RAIN. THE
RAIN WILL MOVE OUT OF THE AREA ON SATURDAY AND THE WEATHER SHOULD BE
DRY UNTIL MONDAY WHEN ANOTHER SYSTEM BRINGS CHANCES FOR RAIN AND
THEN SNOW MONDAY NIGHT.
&&
.NEAR TERM /TODAY/...
ISSUED AT 955 AM EST THU DEC 4 2014
PAP13 SOUNDINGS...BUFKIT...IND DUAL POL AND MOST IMPORTANTLY THE HUF
OBS AND REPORTS OVER THE TERRE HAUTE AREA NECCESSITATE ADDING SNOW
AND SLEET TO THE GRIDS THROUGH EARLY AFTERNOON. THE MIX SHOULD
CHANGE TO ALL RAIN FROM SOUTHWEST TO NORTHEAST AND BECOME RAIN
ACROSS ALL OF CENTRAL INDIANA AFTER 1 PM. ALSO BROUGHT POPS FURTHER
NORTH BASED ON MORE MOIST PAP13 SOUNDINGS ALONG WITH 295 ISENTROPIC
CONDENSATION PRESSURE DEFEICITS.
PREVIOUS DISCUSSION FOLLOWS...
CURRENTLY RADAR MOSAIC IS SHOWING WEAK ECHOES MOVING INTO
SOUTHWESTERN INDIANA. UPSTREAM OBSERVATIONS SHOW SOME OF THIS IS
REACHING THE GROUND IN THE FORM OF DRIZZLE OR VERY LIGHT RAIN...AND
SOME IS NOT REACHING THE GROUND AT ALL. HRRR SEEMS TO HAVE A BETTER
HANDLE ON THIS THAN OTHER MODELS AND THUS FOLLOWED IT FAIRLY
CLOSELY...ADDING IN PATCHY DRIZZLE OR FREEZING DRIZZLE IN THE
SOUTHWEST INITIALLY AND MOVING IN NORTHEAST OVER THE NEXT SEVERAL
HOURS. HAVE THIS POTENTIAL REACHING THE INDY METRO AROUND 7-9 AM.
WITH TEMPERATURES BELOW FREEZING CURRENTLY ACROSS MOST OF THE AREA
DECIDED TO INCLUDE THE FREEZING DRIZZLE MENTION...BUT HAVE SEEN SOME
WARMING AT THE SURFACE AS CLOUDS MOVE IN SO HOPEFULLY THIS WILL HELP
MITIGATE ANY POTENTIAL ICING ISSUES. TEMPERATURES SHOULD MAKE IT
ABOVE FREEZING ACROSS THE ENTIRE AREA BY MID MORNING AND AFTER THAT
CHANCES FOR MEASURABLE RAIN WILL MOVE IN FROM THE SOUTHWEST AS AN
UPPER WAVE APPROACHES HIGH PRESSURE MOVES OFF TO THE NORTHEAST.
INCREASED POPS IN THE SOUTH FOR THE AFTERNOON FROM MOS BASED ON
OUTPUT FROM RAPID UPDATE MODELS AND DECENT FORCING FROM THE QUICK
MOVING UPPER WAVE.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 423 AM EST THU DEC 4 2014
FORECAST FOCUS IS ON PRECIP CHANCES. MODELS IN PRETTY GOOD AGREEMENT
AND GENERALLY STUCK CLOSE TO A CONSENSUS. FOR TONIGHT MODELS HAVE
BACKED OFF SOME ON PRECIP CHANCES AS THE FIRST UPPER SHORTWAVE WILL
BE PAST BUT THE NEXT ONE WILL NOT ARRIVE UNTIL FRIDAY MORNING. WITH
THE FRONT FORMING ALONG OR JUST SOUTH OF THE OHIO RIVER WILL STILL
HAVE SOME ISENTROPIC LIFT ESPECIALLY FURTHER SOUTH CLOSEST TO THE
FRONT SO WILL MAINTAIN CHANCE POPS THERE AND TAPER TO SLIGHT CHANCE
IN THE NORTH. POPS WILL INCREASE BY FRIDAY MORNING AS THE NEXT UPPER
WAVE APPROACHES AND FRONTOGENESIS INCREASES ACROSS THE SOUTH. BY THE
AFTERNOON THE SURFACE LOW WILL EJECT FROM THE PLAINS AND MOVE CLOSER
BRINGING CATEGORICAL RAIN TO THE AREA. THIS WILL STAY IN PLACE
DURING THE OVERNIGHT AS THE SURFACE LOW MOVES ALONG THE FRONT AND
ALONG THE OHIO RIVER AND THEN THE UPPER TROUGH PASSES THROUGH EARLY
SATURDAY MORNING. MODELS ARE MOVING THIS THROUGH A LITTLE FASTER AND
THUS DECREASED POPS FOR SATURDAY MORNING KEEPING CHANCES ACROSS THE
EAST TO DRY IN THE NORTHWEST AND BY AFTERNOON BROUGHT DRY WEATHER TO
ALL BUT THE FAR EASTERN COUNTIES. SATURDAY NIGHT WILL BE DRY AS HIGH
PRESSURE BUILDS IN.
FOR PRECIPITATION TYPE TONIGHT AND EARLY FRIDAY MORNING...A FEW
HOURS OF FREEZING RAIN ARE POSSIBLE IN THE NORTHERN COUNTIES AS
TEMPERATURES SHOULD DIP JUST BELOW FREEZING. NOT EXPECTING MUCH IN
THE WAY OF ICE ACCUMULATION...BUT TEMPERATURES COULD REMAIN AT OR
BELOW FREEZING IN THE NORTHERN COUNTIES UNTIL MID MORNING FRIDAY.
ON RAINFALL TOTALS...COULD SEE MORE THAN AN INCH AND A HALF ACROSS
PARTS OF THE AREA BETWEEN FRIDAY AND FRIDAY NIGHT WITH STRONG
FORCING...GOOD LOW LEVEL JET BRING IN AMPLE MOISTURE AND OVERALL
SLOW SYSTEM MOTION. HOWEVER PLACEMENT OF THE HEAVIEST AXIS IS A
LITTLE TRICKY WITH MODELS VARYING IT FROM NEAR THE OHIO RIVER TO
ACROSS THE CENTRAL PART OF THE FORECAST AREA.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 230 AM EST THU DEC 4 2014
BROAD HIGH PRESSURE WILL BRING DRY COOL CONDITIONS ON SUNDAY IN
THE WAKE OF THE FRIDAY/SATURDAY SYSTEM. THE HIGH WILL SHIFT EAST
QUICKLY SUNDAY NIGHT...WITH AN UPPER WAVE AND ASSOCIATED LOW
PRESSURE SYSTEM TRACKING INTO THE GREAT LAKES FROM THE NORTHERN
PLAINS ON MONDAY. THE GLOBAL MODELS HAVE BEEN MORE AMPLIFIED WITH
THE UPPER FLOW PATTERN...AND CONSEQUENTLY BRING THE UPPER WAVE
FURTHER SOUTH INTO THE OHIO VALLEY. CONSIDERING THE RIDGING
EXPECTED TO DEVELOP OVER THE INTERMOUNTAIN WEST AHEAD OF STRONG
LOW PRESSURE INTO THE GULF OF ALASKA...THE MORE AMPLIFIED PATTERN
ALOFT SUGGESTED BY THE GLOBALS IS MORE REALISTIC AND PREFERRED AT
THIS TIME. HAVE INCREASED POPS SLIGHTLY OVER SUPERBLEND GUIDANCE
FOR MONDAY AND MONDAY NIGHT AS THE UPPER WAVE PASSES THROUGH THE
REGION...WITH LIGHT RAIN CHANGING TO LIGHT SNOW AS COLDER AIR
ARRIVES.
REMAINDER OF THE EXTENDED LOOKS QUIET AS A DRY NORTHWEST FLOW
ALOFT DEVELOPS WITH HIGH PRESSURE AT THE SURFACE. GLOBAL GUIDANCE
IS PREFERRED THROUGH THE END OF THE LONG TERM AS OP GFS CONTINUES
TO FAVOR A MUCH FLATTER AND MORE PROGRESSIVE FLOW PATTERN ALOFT
AND IS OUT OF STEP WITH MOST OF THE OTHER EXTENDED GUIDANCE.
UNDERCUT SUPERBLEND FOR TEMPS THROUGHOUT...WITH HIGHS PRIMARILY
RANGING FROM THE UPPER 30S TO MID 40S AND LOWS IN THE 20S TO LOWER
30S.
&&
.AVIATION /DISCUSSION FOR THE 041800Z TAFS/...
ISSUED AT 1146 AM EST THU DEC 4 2014
AREA OF MIXED PRECIPITATION CONTINUES TO MOVE MAINLY ACROSS THE
SOUTHERN PARTS OF THE FORECAST AREA. THIS MORNING/S UPPER AIR
INDICATED A RATHER LARGE ELEVATED WARM LAYER...BUT ALSO VERY DRY AIR
AT THAT LEVEL. EVAPORATIVE COOLING PROCESSES HAVE KEPT PRECIPITATION
MAINLY IN THE FORM OF SNOW ALONG THE NORTHERN FRINGES OF THE
PRECIPITATION AREA.
APPEARS PRECIPITATION AREA WILL BE PASSING OFF TO THE EAST OF THE
TAF SITES BY 042000Z. WILL KEEP SOME OCCASIONAL IFR VISIBILITY
RESTRICTIONS IN SNOW/SLEET...MAINLY AT KIND...BASED ON SURFACE
OBSERVATIONS. EXPECTING MAINLY RAIN OR A RAIN/SLEET MIX FARTHER
SOUTH AT KBMG. KLAF MAY SEE A BRIEF PERIOD OF LIGHT SNOW/SLEET EARLY
THIS AFTERNOON...BUT OVERALL MOST OF THE PRECIPITATION SHOULD REMAIN
TO THE SOUTH OF KLAF.
CEILINGS THIS AFTERNOON IN THE 025-050 RANGE SHOULD GRADUALLY FALL
BELOW 020 EARLY THIS EVENING FROM SOUTH TO NORTH...AND WILL PROBABLY
FALL INTO THE IFR CATEGORY LATER TONIGHT UNDER CONTINUED WARM
ADVECTION.
SURFACE WINDS GENERALLY 090-110 AT 6-8 KTS THIS AFTERNOON SHOULD
BECOME LIGHT AFTER DARK.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP/MK
NEAR TERM...CP/MK
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
955 AM EST THU DEC 4 2014
.UPDATE...
THE SYNOPSIS AND NEAR TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 950 AM EST THU DEC 4 2014
AN UPPER WAVE AND MOISTENING SOUTHWEST UPGLIDE WILL BRING MIXED
PRECIPITATION TO CENTRAL INDIANA THROUGH EARLY AFTERNOON BEFORE THE
PRECIPITATION CHANGES TO RAIN. MEANWHILE...A FRONTAL SYSTEM ACROSS
THE GULF STATES WILL GRADUALLY LIFT NORTHEAST AND ACROSS CENTRAL
INDIANA EARLY THIS WEEKEND. THIS WILL BRING RAIN TO THE AREA...AS
WELL AS COUPLE OF BRIEF CHANCES FOR SOME LIGHT FREEZING RAIN. THE
RAIN WILL MOVE OUT OF THE AREA ON SATURDAY AND THE WEATHER SHOULD BE
DRY UNTIL MONDAY WHEN ANOTHER SYSTEM BRINGS CHANCES FOR RAIN AND
THEN SNOW MONDAY NIGHT.
&&
.NEAR TERM /TODAY/...
ISSUED AT 955 AM EST THU DEC 4 2014
PAP13 SOUNDINGS...BUFKIT...IND DUAL POL AND MOST IMPORTANTLY THE HUF
OBS AND REPORTS OVER THE TERRE HAUTE AREA NECCESSITATE ADDING SNOW
AND SLEET TO THE GRIDS THROUGH EARLY AFTERNOON. THE MIX SHOULD
CHANGE TO ALL RAIN FROM SOUTHWEST TO NORTHEAST AND BECOME RAIN
ACROSS ALL OF CENTRAL INDIANA AFTER 1 PM. ALSO BROUGHT POPS FURTHER
NORTH BASED ON MORE MOIST PAP13 SOUNDINGS ALONG WITH 295 ISENTROPIC
CONDENSATION PRESSURE DEFEICITS.
PREVIOUS DISCUSSION FOLLOWS...
CURRENTLY RADAR MOSAIC IS SHOWING WEAK ECHOES MOVING INTO
SOUTHWESTERN INDIANA. UPSTREAM OBSERVATIONS SHOW SOME OF THIS IS
REACHING THE GROUND IN THE FORM OF DRIZZLE OR VERY LIGHT RAIN...AND
SOME IS NOT REACHING THE GROUND AT ALL. HRRR SEEMS TO HAVE A BETTER
HANDLE ON THIS THAN OTHER MODELS AND THUS FOLLOWED IT FAIRLY
CLOSELY...ADDING IN PATCHY DRIZZLE OR FREEZING DRIZZLE IN THE
SOUTHWEST INITIALLY AND MOVING IN NORTHEAST OVER THE NEXT SEVERAL
HOURS. HAVE THIS POTENTIAL REACHING THE INDY METRO AROUND 7-9 AM.
WITH TEMPERATURES BELOW FREEZING CURRENTLY ACROSS MOST OF THE AREA
DECIDED TO INCLUDE THE FREEZING DRIZZLE MENTION...BUT HAVE SEEN SOME
WARMING AT THE SURFACE AS CLOUDS MOVE IN SO HOPEFULLY THIS WILL HELP
MITIGATE ANY POTENTIAL ICING ISSUES. TEMPERATURES SHOULD MAKE IT
ABOVE FREEZING ACROSS THE ENTIRE AREA BY MID MORNING AND AFTER THAT
CHANCES FOR MEASURABLE RAIN WILL MOVE IN FROM THE SOUTHWEST AS AN
UPPER WAVE APPROACHES HIGH PRESSURE MOVES OFF TO THE NORTHEAST.
INCREASED POPS IN THE SOUTH FOR THE AFTERNOON FROM MOS BASED ON
OUTPUT FROM RAPID UPDATE MODELS AND DECENT FORCING FROM THE QUICK
MOVING UPPER WAVE.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 423 AM EST THU DEC 4 2014
FORECAST FOCUS IS ON PRECIP CHANCES. MODELS IN PRETTY GOOD AGREEMENT
AND GENERALLY STUCK CLOSE TO A CONSENSUS. FOR TONIGHT MODELS HAVE
BACKED OFF SOME ON PRECIP CHANCES AS THE FIRST UPPER SHORTWAVE WILL
BE PAST BUT THE NEXT ONE WILL NOT ARRIVE UNTIL FRIDAY MORNING. WITH
THE FRONT FORMING ALONG OR JUST SOUTH OF THE OHIO RIVER WILL STILL
HAVE SOME ISENTROPIC LIFT ESPECIALLY FURTHER SOUTH CLOSEST TO THE
FRONT SO WILL MAINTAIN CHANCE POPS THERE AND TAPER TO SLIGHT CHANCE
IN THE NORTH. POPS WILL INCREASE BY FRIDAY MORNING AS THE NEXT UPPER
WAVE APPROACHES AND FRONTOGENESIS INCREASES ACROSS THE SOUTH. BY THE
AFTERNOON THE SURFACE LOW WILL EJECT FROM THE PLAINS AND MOVE CLOSER
BRINGING CATEGORICAL RAIN TO THE AREA. THIS WILL STAY IN PLACE
DURING THE OVERNIGHT AS THE SURFACE LOW MOVES ALONG THE FRONT AND
ALONG THE OHIO RIVER AND THEN THE UPPER TROUGH PASSES THROUGH EARLY
SATURDAY MORNING. MODELS ARE MOVING THIS THROUGH A LITTLE FASTER AND
THUS DECREASED POPS FOR SATURDAY MORNING KEEPING CHANCES ACROSS THE
EAST TO DRY IN THE NORTHWEST AND BY AFTERNOON BROUGHT DRY WEATHER TO
ALL BUT THE FAR EASTERN COUNTIES. SATURDAY NIGHT WILL BE DRY AS HIGH
PRESSURE BUILDS IN.
FOR PRECIPITATION TYPE TONIGHT AND EARLY FRIDAY MORNING...A FEW
HOURS OF FREEZING RAIN ARE POSSIBLE IN THE NORTHERN COUNTIES AS
TEMPERATURES SHOULD DIP JUST BELOW FREEZING. NOT EXPECTING MUCH IN
THE WAY OF ICE ACCUMULATION...BUT TEMPERATURES COULD REMAIN AT OR
BELOW FREEZING IN THE NORTHERN COUNTIES UNTIL MID MORNING FRIDAY.
ON RAINFALL TOTALS...COULD SEE MORE THAN AN INCH AND A HALF ACROSS
PARTS OF THE AREA BETWEEN FRIDAY AND FRIDAY NIGHT WITH STRONG
FORCING...GOOD LOW LEVEL JET BRING IN AMPLE MOISTURE AND OVERALL
SLOW SYSTEM MOTION. HOWEVER PLACEMENT OF THE HEAVIEST AXIS IS A
LITTLE TRICKY WITH MODELS VARYING IT FROM NEAR THE OHIO RIVER TO
ACROSS THE CENTRAL PART OF THE FORECAST AREA.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 230 AM EST THU DEC 4 2014
BROAD HIGH PRESSURE WILL BRING DRY COOL CONDITIONS ON SUNDAY IN
THE WAKE OF THE FRIDAY/SATURDAY SYSTEM. THE HIGH WILL SHIFT EAST
QUICKLY SUNDAY NIGHT...WITH AN UPPER WAVE AND ASSOCIATED LOW
PRESSURE SYSTEM TRACKING INTO THE GREAT LAKES FROM THE NORTHERN
PLAINS ON MONDAY. THE GLOBAL MODELS HAVE BEEN MORE AMPLIFIED WITH
THE UPPER FLOW PATTERN...AND CONSEQUENTLY BRING THE UPPER WAVE
FURTHER SOUTH INTO THE OHIO VALLEY. CONSIDERING THE RIDGING
EXPECTED TO DEVELOP OVER THE INTERMOUNTAIN WEST AHEAD OF STRONG
LOW PRESSURE INTO THE GULF OF ALASKA...THE MORE AMPLIFIED PATTERN
ALOFT SUGGESTED BY THE GLOBALS IS MORE REALISTIC AND PREFERRED AT
THIS TIME. HAVE INCREASED POPS SLIGHTLY OVER SUPERBLEND GUIDANCE
FOR MONDAY AND MONDAY NIGHT AS THE UPPER WAVE PASSES THROUGH THE
REGION...WITH LIGHT RAIN CHANGING TO LIGHT SNOW AS COLDER AIR
ARRIVES.
REMAINDER OF THE EXTENDED LOOKS QUIET AS A DRY NORTHWEST FLOW
ALOFT DEVELOPS WITH HIGH PRESSURE AT THE SURFACE. GLOBAL GUIDANCE
IS PREFERRED THROUGH THE END OF THE LONG TERM AS OP GFS CONTINUES
TO FAVOR A MUCH FLATTER AND MORE PROGRESSIVE FLOW PATTERN ALOFT
AND IS OUT OF STEP WITH MOST OF THE OTHER EXTENDED GUIDANCE.
UNDERCUT SUPERBLEND FOR TEMPS THROUGHOUT...WITH HIGHS PRIMARILY
RANGING FROM THE UPPER 30S TO MID 40S AND LOWS IN THE 20S TO LOWER
30S.
&&
.AVIATION /DISCUSSION FOR THE 041500Z KIND TAF UPDATE/...
ISSUED AT 936 AM EST THU DEC 4 2014
THIS MORNING/S UPPER AIR INDICATES A RATHER LARGE ELEVATED WARM
LAYER...BUT ALSO VERY DRY AIR AT THAT LEVEL. THINK EVAPORATIVE
COOLING PROCESSES MAY KEEP PRECIPITATION MORE OF THE FROZEN TYPE A
LITTLE LONGER AT KIND. WILL KEEP THE SNOW/SLEET MIX IN THE FORECAST
THROUGH 041800Z. SOME OF THE HEAVIER ECHOES ARE BEGINNING TO PRODUCE
LOCALIZED IFR VISIBILITY RESTRICTIONS...SO WILL LOWER THE VISIBILITY
FORECAST SOME.
BRIEF PERIOD OF FREEZING RAIN STILL POSSIBLE THROUGH ABOUT MIDDAY AT
KIND...BUT THE WINDOW APPEARS TO BE NARROWING.
PREVIOUS DISCUSSION FOLLOWS.
RADAR INDICATES SOME PRECIPITATION MOVING INTO THE WEST CENTRAL AND
SOUTHWEST PARTS OF THE FORECAST AREA AT THIS TIME. NOT SEEING ANY
SURFACE REPORTS OF ANYTHING HITTING THE GROUND...BUT BASED ON THE
INTENSITY OF SOME OF THE ECHOES...THINK AT LEAST SOME PATCHY
PRECIPITATION IS REACHING THE GROUND. THICKNESSES OFF OF THE SHORT
TERM MODELS SUGGEST MAINLY SNOW OR SLEET...WITH MAYBE A SMALL WINDOW
OF FREEZING RAIN POTENTIAL AFTER SUNRISE THROUGH ABOUT 041600Z.
PRECIPITATION SHOULD BE LIGHT ENOUGH TO NOT IMPACT VISIBILITIES TOO
MUCH.
BETTER CHANCES FOR MORE ORGANIZED RAIN LATER THIS AFTERNOON.
CEILINGS EXPECTED TO GRADUALLY FALL TODAY THROUGH 050...REACHING
MVFR OVER THE SOUTHERN TAF SITES BY LATE AFTERNOON.
LIGHT SURFACE WINDS EARLY THIS MORNING SHOULD BECOME 090-110 DEGREES
AT 6-9 KTS BY MIDDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP/MK
NEAR TERM...CP/MK
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
936 AM EST THU DEC 4 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 423 AM EST THU DEC 4 2014
AN ACTIVE WEATHER PATTERN IS IN PLACE FOR THE NEXT COUPLE OF DAYS AS
LOW PRESSURE FORMS OVER THE PLAINS AND BRINGS A FRONTAL SYSTEM
THROUGH CENTRAL INDIANA. THIS WILL BRING RAIN TO THE AREA...AS WELL
AS COUPLE OF BRIEF CHANCES FOR SOME LIGHT FREEZING RAIN IN AREAS.
RAIN WILL MOVE OUT OF THE AREA ON SATURDAY AND THE WEATHER SHOULD BE
DRY UNTIL MONDAY WHEN ANOTHER SYSTEM BRINGS CHANCES FOR RAIN AND
THEN SNOW MONDAY NIGHT.
&&
.NEAR TERM /EARLY THIS MORNING AND TODAY/...
ISSUED AT 423 AM EST THU DEC 4 2014
CURRENTLY RADAR MOSAIC IS SHOWING WEAK ECHOES MOVING INTO
SOUTHWESTERN INDIANA. UPSTREAM OBSERVATIONS SHOW SOME OF THIS IS
REACHING THE GROUND IN THE FORM OF DRIZZLE OR VERY LIGHT RAIN...AND
SOME IS NOT REACHING THE GROUND AT ALL. HRRR SEEMS TO HAVE A BETTER
HANDLE ON THIS THAN OTHER MODELS AND THUS FOLLOWED IT FAIRLY
CLOSELY...ADDING IN PATCHY DRIZZLE OR FREEZING DRIZZLE IN THE
SOUTHWEST INITIALLY AND MOVING IN NORTHEAST OVER THE NEXT SEVERAL
HOURS. HAVE THIS POTENTIAL REACHING THE INDY METRO AROUND 7-9 AM.
WITH TEMPERATURES BELOW FREEZING CURRENTLY ACROSS MOST OF THE AREA
DECIDED TO INCLUDE THE FREEZING DRIZZLE MENTION...BUT HAVE SEEN SOME
WARMING AT THE SURFACE AS CLOUDS MOVE IN SO HOPEFULLY THIS WILL HELP
MITIGATE ANY POTENTIAL ICING ISSUES. TEMPERATURES SHOULD MAKE IT
ABOVE FREEZING ACROSS THE ENTIRE AREA BY MID MORNING AND AFTER THAT
CHANCES FOR MEASURABLE RAIN WILL MOVE IN FROM THE SOUTHWEST AS AN
UPPER WAVE APPROACHES HIGH PRESSURE MOVES OFF TO THE NORTHEAST.
INCREASED POPS IN THE SOUTH FOR THE AFTERNOON FROM MOS BASED ON
OUTPUT FROM RAPID UPDATE MODELS AND DECENT FORCING FROM THE QUICK
MOVING UPPER WAVE.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 423 AM EST THU DEC 4 2014
FORECAST FOCUS IS ON PRECIP CHANCES. MODELS IN PRETTY GOOD AGREEMENT
AND GENERALLY STUCK CLOSE TO A CONSENSUS. FOR TONIGHT MODELS HAVE
BACKED OFF SOME ON PRECIP CHANCES AS THE FIRST UPPER SHORTWAVE WILL
BE PAST BUT THE NEXT ONE WILL NOT ARRIVE UNTIL FRIDAY MORNING. WITH
THE FRONT FORMING ALONG OR JUST SOUTH OF THE OHIO RIVER WILL STILL
HAVE SOME ISENTROPIC LIFT ESPECIALLY FURTHER SOUTH CLOSEST TO THE
FRONT SO WILL MAINTAIN CHANCE POPS THERE AND TAPER TO SLIGHT CHANCE
IN THE NORTH. POPS WILL INCREASE BY FRIDAY MORNING AS THE NEXT UPPER
WAVE APPROACHES AND FRONTOGENESIS INCREASES ACROSS THE SOUTH. BY THE
AFTERNOON THE SURFACE LOW WILL EJECT FROM THE PLAINS AND MOVE CLOSER
BRINGING CATEGORICAL RAIN TO THE AREA. THIS WILL STAY IN PLACE
DURING THE OVERNIGHT AS THE SURFACE LOW MOVES ALONG THE FRONT AND
ALONG THE OHIO RIVER AND THEN THE UPPER TROUGH PASSES THROUGH EARLY
SATURDAY MORNING. MODELS ARE MOVING THIS THROUGH A LITTLE FASTER AND
THUS DECREASED POPS FOR SATURDAY MORNING KEEPING CHANCES ACROSS THE
EAST TO DRY IN THE NORTHWEST AND BY AFTERNOON BROUGHT DRY WEATHER TO
ALL BUT THE FAR EASTERN COUNTIES. SATURDAY NIGHT WILL BE DRY AS HIGH
PRESSURE BUILDS IN.
FOR PRECIPITATION TYPE TONIGHT AND EARLY FRIDAY MORNING...A FEW HOURS OF
FREEZING RAIN ARE POSSIBLE IN THE NORTHERN COUNTIES AS TEMPERATURES
SHOULD DIP JUST BELOW FREEZING. NOT EXPECTING MUCH IN THE WAY OF ICE
ACCUMULATION...BUT TEMPERATURES COULD REMAIN AT OR BELOW FREEZING IN
THE NORTHERN COUNTIES UNTIL MID MORNING FRIDAY.
ON RAINFALL TOTALS...COULD SEE MORE THAN AN INCH AND A HALF ACROSS
PARTS OF THE AREA BETWEEN FRIDAY AND FRIDAY NIGHT WITH STRONG
FORCING...GOOD LOW LEVEL JET BRING IN AMPLE MOISTURE AND OVERALL
SLOW SYSTEM MOTION. HOWEVER PLACEMENT OF THE HEAVIEST AXIS IS A
LITTLE TRICKY WITH MODELS VARYING IT FROM NEAR THE OHIO RIVER TO
ACROSS THE CENTRAL PART OF THE FORECAST AREA.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 230 AM EST THU DEC 4 2014
BROAD HIGH PRESSURE WILL BRING DRY COOL CONDITIONS ON SUNDAY IN
THE WAKE OF THE FRIDAY/SATURDAY SYSTEM. THE HIGH WILL SHIFT EAST
QUICKLY SUNDAY NIGHT...WITH AN UPPER WAVE AND ASSOCIATED LOW
PRESSURE SYSTEM TRACKING INTO THE GREAT LAKES FROM THE NORTHERN
PLAINS ON MONDAY. THE GLOBAL MODELS HAVE BEEN MORE AMPLIFIED WITH
THE UPPER FLOW PATTERN...AND CONSEQUENTLY BRING THE UPPER WAVE
FURTHER SOUTH INTO THE OHIO VALLEY. CONSIDERING THE RIDGING
EXPECTED TO DEVELOP OVER THE INTERMOUNTAIN WEST AHEAD OF STRONG
LOW PRESSURE INTO THE GULF OF ALASKA...THE MORE AMPLIFIED PATTERN
ALOFT SUGGESTED BY THE GLOBALS IS MORE REALISTIC AND PREFERRED AT
THIS TIME. HAVE INCREASED POPS SLIGHTLY OVER SUPERBLEND GUIDANCE
FOR MONDAY AND MONDAY NIGHT AS THE UPPER WAVE PASSES THROUGH THE
REGION...WITH LIGHT RAIN CHANGING TO LIGHT SNOW AS COLDER AIR
ARRIVES.
REMAINDER OF THE EXTENDED LOOKS QUIET AS A DRY NORTHWEST FLOW
ALOFT DEVELOPS WITH HIGH PRESSURE AT THE SURFACE. GLOBAL GUIDANCE
IS PREFERRED THROUGH THE END OF THE LONG TERM AS OP GFS CONTINUES
TO FAVOR A MUCH FLATTER AND MORE PROGRESSIVE FLOW PATTERN ALOFT
AND IS OUT OF STEP WITH MOST OF THE OTHER EXTENDED GUIDANCE.
UNDERCUT SUPERBLEND FOR TEMPS THROUGHOUT...WITH HIGHS PRIMARILY
RANGING FROM THE UPPER 30S TO MID 40S AND LOWS IN THE 20S TO LOWER
30S.
&&
.AVIATION /DISCUSSION FOR THE 041500Z KIND TAF UPDATE/...
ISSUED AT 936 AM EST THU DEC 4 2014
THIS MORNING/S UPPER AIR INDICATES A RATHER LARGE ELEVATED WARM
LAYER...BUT ALSO VERY DRY AIR AT THAT LEVEL. THINK EVAPORATIVE
COOLING PROCESSES MAY KEEP PRECIPITATION MORE OF THE FROZEN TYPE A
LITTLE LONGER AT KIND. WILL KEEP THE SNOW/SLEET MIX IN THE FORECAST
THROUGH 041800Z. SOME OF THE HEAVIER ECHOES ARE BEGINNING TO PRODUCE
LOCALIZED IFR VISIBILITY RESTRICTIONS...SO WILL LOWER THE VISIBILITY
FORECAST SOME.
BRIEF PERIOD OF FREEZING RAIN STILL POSSIBLE THROUGH ABOUT MIDDAY AT
KIND...BUT THE WINDOW APPEARS TO BE NARROWING.
PREVIOUS DISCUSSION FOLLOWS.
RADAR INDICATES SOME PRECIPITATION MOVING INTO THE WEST CENTRAL AND
SOUTHWEST PARTS OF THE FORECAST AREA AT THIS TIME. NOT SEEING ANY
SURFACE REPORTS OF ANYTHING HITTING THE GROUND...BUT BASED ON THE
INTENSITY OF SOME OF THE ECHOES...THINK AT LEAST SOME PATCHY
PRECIPITATION IS REACHING THE GROUND. THICKNESSES OFF OF THE SHORT
TERM MODELS SUGGEST MAINLY SNOW OR SLEET...WITH MAYBE A SMALL WINDOW
OF FREEZING RAIN POTENTIAL AFTER SUNRISE THROUGH ABOUT 041600Z.
PRECIPITATION SHOULD BE LIGHT ENOUGH TO NOT IMPACT VISIBILITIES TOO
MUCH.
BETTER CHANCES FOR MORE ORGANIZED RAIN LATER THIS AFTERNOON.
CEILINGS EXPECTED TO GRADUALLY FALL TODAY THROUGH 050...REACHING
MVFR OVER THE SOUTHERN TAF SITES BY LATE AFTERNOON.
LIGHT SURFACE WINDS EARLY THIS MORNING SHOULD BECOME 090-110 DEGREES
AT 6-9 KTS BY MIDDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
637 AM EST THU DEC 4 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 423 AM EST THU DEC 4 2014
AN ACTIVE WEATHER PATTERN IS IN PLACE FOR THE NEXT COUPLE OF DAYS AS
LOW PRESSURE FORMS OVER THE PLAINS AND BRINGS A FRONTAL SYSTEM
THROUGH CENTRAL INDIANA. THIS WILL BRING RAIN TO THE AREA...AS WELL
AS COUPLE OF BRIEF CHANCES FOR SOME LIGHT FREEZING RAIN IN AREAS.
RAIN WILL MOVE OUT OF THE AREA ON SATURDAY AND THE WEATHER SHOULD BE
DRY UNTIL MONDAY WHEN ANOTHER SYSTEM BRINGS CHANCES FOR RAIN AND
THEN SNOW MONDAY NIGHT.
&&
.NEAR TERM /EARLY THIS MORNING AND TODAY/...
ISSUED AT 423 AM EST THU DEC 4 2014
CURRENTLY RADAR MOSAIC IS SHOWING WEAK ECHOES MOVING INTO
SOUTHWESTERN INDIANA. UPSTREAM OBSERVATIONS SHOW SOME OF THIS IS
REACHING THE GROUND IN THE FORM OF DRIZZLE OR VERY LIGHT RAIN...AND
SOME IS NOT REACHING THE GROUND AT ALL. HRRR SEEMS TO HAVE A BETTER
HANDLE ON THIS THAN OTHER MODELS AND THUS FOLLOWED IT FAIRLY
CLOSELY...ADDING IN PATCHY DRIZZLE OR FREEZING DRIZZLE IN THE
SOUTHWEST INITIALLY AND MOVING IN NORTHEAST OVER THE NEXT SEVERAL
HOURS. HAVE THIS POTENTIAL REACHING THE INDY METRO AROUND 7-9 AM.
WITH TEMPERATURES BELOW FREEZING CURRENTLY ACROSS MOST OF THE AREA
DECIDED TO INCLUDE THE FREEZING DRIZZLE MENTION...BUT HAVE SEEN SOME
WARMING AT THE SURFACE AS CLOUDS MOVE IN SO HOPEFULLY THIS WILL HELP
MITIGATE ANY POTENTIAL ICING ISSUES. TEMPERATURES SHOULD MAKE IT
ABOVE FREEZING ACROSS THE ENTIRE AREA BY MID MORNING AND AFTER THAT
CHANCES FOR MEASURABLE RAIN WILL MOVE IN FROM THE SOUTHWEST AS AN
UPPER WAVE APPROACHES HIGH PRESSURE MOVES OFF TO THE NORTHEAST.
INCREASED POPS IN THE SOUTH FOR THE AFTERNOON FROM MOS BASED ON
OUTPUT FROM RAPID UPDATE MODELS AND DECENT FORCING FROM THE QUICK
MOVING UPPER WAVE.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 423 AM EST THU DEC 4 2014
FORECAST FOCUS IS ON PRECIP CHANCES. MODELS IN PRETTY GOOD AGREEMENT
AND GENERALLY STUCK CLOSE TO A CONSENSUS. FOR TONIGHT MODELS HAVE
BACKED OFF SOME ON PRECIP CHANCES AS THE FIRST UPPER SHORTWAVE WILL
BE PAST BUT THE NEXT ONE WILL NOT ARRIVE UNTIL FRIDAY MORNING. WITH
THE FRONT FORMING ALONG OR JUST SOUTH OF THE OHIO RIVER WILL STILL
HAVE SOME ISENTROPIC LIFT ESPECIALLY FURTHER SOUTH CLOSEST TO THE
FRONT SO WILL MAINTAIN CHANCE POPS THERE AND TAPER TO SLIGHT CHANCE
IN THE NORTH. POPS WILL INCREASE BY FRIDAY MORNING AS THE NEXT UPPER
WAVE APPROACHES AND FRONTOGENESIS INCREASES ACROSS THE SOUTH. BY THE
AFTERNOON THE SURFACE LOW WILL EJECT FROM THE PLAINS AND MOVE CLOSER
BRINGING CATEGORICAL RAIN TO THE AREA. THIS WILL STAY IN PLACE
DURING THE OVERNIGHT AS THE SURFACE LOW MOVES ALONG THE FRONT AND
ALONG THE OHIO RIVER AND THEN THE UPPER TROUGH PASSES THROUGH EARLY
SATURDAY MORNING. MODELS ARE MOVING THIS THROUGH A LITTLE FASTER AND
THUS DECREASED POPS FOR SATURDAY MORNING KEEPING CHANCES ACROSS THE
EAST TO DRY IN THE NORTHWEST AND BY AFTERNOON BROUGHT DRY WEATHER TO
ALL BUT THE FAR EASTERN COUNTIES. SATURDAY NIGHT WILL BE DRY AS HIGH
PRESSURE BUILDS IN.
FOR PRECIPITATION TYPE TONIGHT AND EARLY FRIDAY MORNING...A FEW HOURS OF
FREEZING RAIN ARE POSSIBLE IN THE NORTHERN COUNTIES AS TEMPERATURES
SHOULD DIP JUST BELOW FREEZING. NOT EXPECTING MUCH IN THE WAY OF ICE
ACCUMULATION...BUT TEMPERATURES COULD REMAIN AT OR BELOW FREEZING IN
THE NORTHERN COUNTIES UNTIL MID MORNING FRIDAY.
ON RAINFALL TOTALS...COULD SEE MORE THAN AN INCH AND A HALF ACROSS
PARTS OF THE AREA BETWEEN FRIDAY AND FRIDAY NIGHT WITH STRONG
FORCING...GOOD LOW LEVEL JET BRING IN AMPLE MOISTURE AND OVERALL
SLOW SYSTEM MOTION. HOWEVER PLACEMENT OF THE HEAVIEST AXIS IS A
LITTLE TRICKY WITH MODELS VARYING IT FROM NEAR THE OHIO RIVER TO
ACROSS THE CENTRAL PART OF THE FORECAST AREA.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 230 AM EST THU DEC 4 2014
BROAD HIGH PRESSURE WILL BRING DRY COOL CONDITIONS ON SUNDAY IN
THE WAKE OF THE FRIDAY/SATURDAY SYSTEM. THE HIGH WILL SHIFT EAST
QUICKLY SUNDAY NIGHT...WITH AN UPPER WAVE AND ASSOCIATED LOW
PRESSURE SYSTEM TRACKING INTO THE GREAT LAKES FROM THE NORTHERN
PLAINS ON MONDAY. THE GLOBAL MODELS HAVE BEEN MORE AMPLIFIED WITH
THE UPPER FLOW PATTERN...AND CONSEQUENTLY BRING THE UPPER WAVE
FURTHER SOUTH INTO THE OHIO VALLEY. CONSIDERING THE RIDGING
EXPECTED TO DEVELOP OVER THE INTERMOUNTAIN WEST AHEAD OF STRONG
LOW PRESSURE INTO THE GULF OF ALASKA...THE MORE AMPLIFIED PATTERN
ALOFT SUGGESTED BY THE GLOBALS IS MORE REALISTIC AND PREFERRED AT
THIS TIME. HAVE INCREASED POPS SLIGHTLY OVER SUPERBLEND GUIDANCE
FOR MONDAY AND MONDAY NIGHT AS THE UPPER WAVE PASSES THROUGH THE
REGION...WITH LIGHT RAIN CHANGING TO LIGHT SNOW AS COLDER AIR
ARRIVES.
REMAINDER OF THE EXTENDED LOOKS QUIET AS A DRY NORTHWEST FLOW
ALOFT DEVELOPS WITH HIGH PRESSURE AT THE SURFACE. GLOBAL GUIDANCE
IS PREFERRED THROUGH THE END OF THE LONG TERM AS OP GFS CONTINUES
TO FAVOR A MUCH FLATTER AND MORE PROGRESSIVE FLOW PATTERN ALOFT
AND IS OUT OF STEP WITH MOST OF THE OTHER EXTENDED GUIDANCE.
UNDERCUT SUPERBLEND FOR TEMPS THROUGHOUT...WITH HIGHS PRIMARILY
RANGING FROM THE UPPER 30S TO MID 40S AND LOWS IN THE 20S TO LOWER
30S.
&&
.AVIATION /DISCUSSION FOR THE 041200Z TAFS/...
ISSUED AT 637 AM EST THU DEC 4 2014
RADAR INDICATES SOME PRECIPITATION MOVING INTO THE WEST CENTRAL AND
SOUTHWEST PARTS OF THE FORECAST AREA AT THIS TIME. NOT SEEING ANY
SURFACE REPORTS OF ANYTHING HITTING THE GROUND...BUT BASED ON THE
INTENSITY OF SOME OF THE ECHOES...THINK AT LEAST SOME PATCHY
PRECIPITATION IS REACHING THE GROUND. THICKNESSES OFF OF THE SHORT
TERM MODELS SUGGEST MAINLY SNOW OR SLEET...WITH MAYBE A SMALL WINDOW
OF FREEZING RAIN POTENTIAL AFTER SUNRISE THROUGH ABOUT 041600Z.
PRECIPITATION SHOULD BE LIGHT ENOUGH TO NOT IMPACT VISIBILITIES TOO
MUCH.
BETTER CHANCES FOR MORE ORGANIZED RAIN LATER THIS AFTERNOON.
CEILINGS EXPECTED TO GRADUALLY FALL TODAY THROUGH 050...REACHING
MVFR OVER THE SOUTHERN TAF SITES BY LATE AFTERNOON.
LIGHT SURFACE WINDS EARLY THIS MORNING SHOULD BECOME 090-110 DEGREES
AT 6-9 KTS BY MIDDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
425 AM EST THU DEC 4 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 423 AM EST THU DEC 4 2014
AN ACTIVE WEATHER PATTERN IS IN PLACE FOR THE NEXT COUPLE OF DAYS AS
LOW PRESSURE FORMS OVER THE PLAINS AND BRINGS A FRONTAL SYSTEM
THROUGH CENTRAL INDIANA. THIS WILL BRING RAIN TO THE AREA...AS WELL
AS COUPLE OF BRIEF CHANCES FOR SOME LIGHT FREEZING RAIN IN AREAS.
RAIN WILL MOVE OUT OF THE AREA ON SATURDAY AND THE WEATHER SHOULD BE
DRY UNTIL MONDAY WHEN ANOTHER SYSTEM BRINGS CHANCES FOR RAIN AND
THEN SNOW MONDAY NIGHT.
&&
.NEAR TERM /EARLY THIS MORNING AND TODAY/...
ISSUED AT 423 AM EST THU DEC 4 2014
CURRENTLY RADAR MOSAIC IS SHOWING WEAK ECHOES MOVING INTO
SOUTHWESTERN INDIANA. UPSTREAM OBSERVATIONS SHOW SOME OF THIS IS
REACHING THE GROUND IN THE FORM OF DRIZZLE OR VERY LIGHT RAIN...AND
SOME IS NOT REACHING THE GROUND AT ALL. HRRR SEEMS TO HAVE A BETTER
HANDLE ON THIS THAN OTHER MODELS AND THUS FOLLOWED IT FAIRLY
CLOSELY...ADDING IN PATCHY DRIZZLE OR FREEZING DRIZZLE IN THE
SOUTHWEST INITIALLY AND MOVING IN NORTHEAST OVER THE NEXT SEVERAL
HOURS. HAVE THIS POTENTIAL REACHING THE INDY METRO AROUND 7-9 AM.
WITH TEMPERATURES BELOW FREEZING CURRENTLY ACROSS MOST OF THE AREA
DECIDED TO INCLUDE THE FREEZING DRIZZLE MENTION...BUT HAVE SEEN SOME
WARMING AT THE SURFACE AS CLOUDS MOVE IN SO HOPEFULLY THIS WILL HELP
MITIGATE ANY POTENTIAL ICING ISSUES. TEMPERATURES SHOULD MAKE IT
ABOVE FREEZING ACROSS THE ENTIRE AREA BY MID MORNING AND AFTER THAT
CHANCES FOR MEASURABLE RAIN WILL MOVE IN FROM THE SOUTHWEST AS AN
UPPER WAVE APPROACHES HIGH PRESSURE MOVES OFF TO THE NORTHEAST.
INCREASED POPS IN THE SOUTH FOR THE AFTERNOON FROM MOS BASED ON
OUTPUT FROM RAPID UPDATE MODELS AND DECENT FORCING FROM THE QUICK
MOVING UPPER WAVE.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 423 AM EST THU DEC 4 2014
FORECAST FOCUS IS ON PRECIP CHANCES. MODELS IN PRETTY GOOD AGREEMENT
AND GENERALLY STUCK CLOSE TO A CONSENSUS. FOR TONIGHT MODELS HAVE
BACKED OFF SOME ON PRECIP CHANCES AS THE FIRST UPPER SHORTWAVE WILL
BE PAST BUT THE NEXT ONE WILL NOT ARRIVE UNTIL FRIDAY MORNING. WITH
THE FRONT FORMING ALONG OR JUST SOUTH OF THE OHIO RIVER WILL STILL
HAVE SOME ISENTROPIC LIFT ESPECIALLY FURTHER SOUTH CLOSEST TO THE
FRONT SO WILL MAINTAIN CHANCE POPS THERE AND TAPER TO SLIGHT CHANCE
IN THE NORTH. POPS WILL INCREASE BY FRIDAY MORNING AS THE NEXT UPPER
WAVE APPROACHES AND FRONTOGENESIS INCREASES ACROSS THE SOUTH. BY THE
AFTERNOON THE SURFACE LOW WILL EJECT FROM THE PLAINS AND MOVE CLOSER
BRINGING CATEGORICAL RAIN TO THE AREA. THIS WILL STAY IN PLACE
DURING THE OVERNIGHT AS THE SURFACE LOW MOVES ALONG THE FRONT AND
ALONG THE OHIO RIVER AND THEN THE UPPER TROUGH PASSES THROUGH EARLY
SATURDAY MORNING. MODELS ARE MOVING THIS THROUGH A LITTLE FASTER AND
THUS DECREASED POPS FOR SATURDAY MORNING KEEPING CHANCES ACROSS THE
EAST TO DRY IN THE NORTHWEST AND BY AFTERNOON BROUGHT DRY WEATHER TO
ALL BUT THE FAR EASTERN COUNTIES. SATURDAY NIGHT WILL BE DRY AS HIGH
PRESSURE BUILDS IN.
FOR PRECIPITATION TYPE TONIGHT AND EARLY FRIDAY MORNING...A FEW HOURS OF
FREEZING RAIN ARE POSSIBLE IN THE NORTHERN COUNTIES AS TEMPERATURES
SHOULD DIP JUST BELOW FREEZING. NOT EXPECTING MUCH IN THE WAY OF ICE
ACCUMULATION...BUT TEMPERATURES COULD REMAIN AT OR BELOW FREEZING IN
THE NORTHERN COUNTIES UNTIL MID MORNING FRIDAY.
ON RAINFALL TOTALS...COULD SEE MORE THAN AN INCH AND A HALF ACROSS
PARTS OF THE AREA BETWEEN FRIDAY AND FRIDAY NIGHT WITH STRONG
FORCING...GOOD LOW LEVEL JET BRING IN AMPLE MOISTURE AND OVERALL
SLOW SYSTEM MOTION. HOWEVER PLACEMENT OF THE HEAVIEST AXIS IS A
LITTLE TRICKY WITH MODELS VARYING IT FROM NEAR THE OHIO RIVER TO
ACROSS THE CENTRAL PART OF THE FORECAST AREA.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 230 AM EST THU DEC 4 2014
BROAD HIGH PRESSURE WILL BRING DRY COOL CONDITIONS ON SUNDAY IN
THE WAKE OF THE FRIDAY/SATURDAY SYSTEM. THE HIGH WILL SHIFT EAST
QUICKLY SUNDAY NIGHT...WITH AN UPPER WAVE AND ASSOCIATED LOW
PRESSURE SYSTEM TRACKING INTO THE GREAT LAKES FROM THE NORTHERN
PLAINS ON MONDAY. THE GLOBAL MODELS HAVE BEEN MORE AMPLIFIED WITH
THE UPPER FLOW PATTERN...AND CONSEQUENTLY BRING THE UPPER WAVE
FURTHER SOUTH INTO THE OHIO VALLEY. CONSIDERING THE RIDGING
EXPECTED TO DEVELOP OVER THE INTERMOUNTAIN WEST AHEAD OF STRONG
LOW PRESSURE INTO THE GULF OF ALASKA...THE MORE AMPLIFIED PATTERN
ALOFT SUGGESTED BY THE GLOBALS IS MORE REALISTIC AND PREFERRED AT
THIS TIME. HAVE INCREASED POPS SLIGHTLY OVER SUPERBLEND GUIDANCE
FOR MONDAY AND MONDAY NIGHT AS THE UPPER WAVE PASSES THROUGH THE
REGION...WITH LIGHT RAIN CHANGING TO LIGHT SNOW AS COLDER AIR
ARRIVES.
REMAINDER OF THE EXTENDED LOOKS QUIET AS A DRY NORTHWEST FLOW
ALOFT DEVELOPS WITH HIGH PRESSURE AT THE SURFACE. GLOBAL GUIDANCE
IS PREFERRED THROUGH THE END OF THE LONG TERM AS OP GFS CONTINUES
TO FAVOR A MUCH FLATTER AND MORE PROGRESSIVE FLOW PATTERN ALOFT
AND IS OUT OF STEP WITH MOST OF THE OTHER EXTENDED GUIDANCE.
UNDERCUT SUPERBLEND FOR TEMPS THROUGHOUT...WITH HIGHS PRIMARILY
RANGING FROM THE UPPER 30S TO MID 40S AND LOWS IN THE 20S TO LOWER
30S.
&&
.AVIATION /DISCUSSION FOR 040600Z TAF ISSUANCE/...
ISSUED AT 1245 AM EST THU DEC 4 2014
VFR CONDITIONS EXPECTED THROUGH THIS MORNING...DETERIORATING
CONDITIONS THIS AFTERNOON AND EVENING WITH PRECIPITATION.
HIGH CLOUDS CONTINUE TO INCREASE EARLY THIS MORNING AS MOISTURE
ALOFT SPREADS INTO THE REGION. LIGHT WINDS WILL GRADUALLY
SET UP FROM THE NORTHEAST LATE TONIGHT AS A FRONTAL BOUNDARY MOVES
INTO THE TENNESSEE VALLEY. LIGHT PRECIPITATION WILL EXPAND
NORTHEAST THROUGH THE LOWER OHIO VALLEY AND INTO CENTRAL INDIANA
DURING THE MORNING. HI RES WRF-ARW AND NMM ALONG WITH THE HRRR ALL
BRING LIGHT PRECIP INTO THE I-70 CORRIDOR BY LATE MORNING. HAVE
BUMPED UP VCSH MENTION AT KBMG/HUF/KIND BETWEEN 12-14Z WITH
PREVAILING LIGHT RAIN DEVELOPING AT ALL SITES BY LATE MORNING. IN
ADDITION WITH COLDER NEAR SURFACE AIR PRESENT IN THE MORNING...MAY
SEE A BRIEF PERIOD OF LIGHT FREEZING DRIZZLE/RAIN AT THE ONSET AT
BOTH KBMG AND KHUF BEFORE WARMING ENOUGH TO SUPPORT RAIN. WILL
CONTINUE TO MONITOR SURFACE TEMP TRENDS OVER THE NEXT FEW HOURS.
MODEL SOUNDINGS INDICATE DRIER AIR WITHIN THE BOUNDARY LAYER WILL
BE SLOW TO SHIFT NORTH WHICH MAY LIMIT PRECIP INITIALLY...BUT
STRONGER SURGE OF ISENTROPIC LIFT DURING THE AFTERNOON SHOULD
ALLOW LOWER MVFR CEILINGS TO EXPAND NORTH. CEILINGS WILL SETTLE
BETWEEN 1500-2000FT BY THE EVENING WITH LOWER VISIBILITIES IN
SCATTERED LIGHT SHOWERS AND/OR DRIZZLE. EASTERLY WINDS AT 5-10KTS
ARE EXPECTED FOR MUCH OF THE DAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
230 AM EST THU DEC 4 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 317 PM EST WED DEC 3 2014
HIGH PRESSURE WILL BRING DRY CONDITIONS TO CENTRAL INDIANA TODAY
AND TONIGHT. HOWEVER...RAIN/FREEZING RAIN WILL BE BACK IN THE
FORECAST BY THURSDAY AS MOISTURE INCREASES AHEAD OF A FRONTAL
BOUNDARY TO THE SOUTH. THIS SURFACE FRONTAL BOUNDARY WILL COMBINE
WITH AN UPPER LEVEL TROUGH BY FRIDAY NIGHT TO PRODUCE WIDESPREAD
RAIN INTO SATURDAY. AFTER THAT...A DRY PERIOD WILL RETURN FOR THE
SECOND HALF OF THE WEEKEND. FURTHER OUT...A STRONG UPPER LEVEL LOW
IS PROGGED TO AFFECT THE AREA ON MONDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 957 PM EST WED DEC 3 2014
TEMPERATURES DROPPED QUICKLY THIS EVENING WHERE CIRRUS THINNED
OUT...BUT SATELLITE SHOWS THICKER CIRRUS MOVING INTO THE AREA AT THE
MOMENT. THUS DO NOT EXPECT TEMPERATURES TO FALL AS FAST...AND THEY
MAY LEVEL OFF IN SOME AREAS WHERE CIRRUS IS THICKEST.
THUS MADE NO CHANGES TO LOW TEMPERATURES...BUT DID ADJUST HOURLY
READINGS TO REFLECT CURRENT TRENDS. ADJUSTED SKY COVER UP SOME ALSO
BASED ON LATEST SATELLITE IMAGES. PRECIPITATION STILL LOOKS TO HOLD
OFF UNTIL AFTER 12Z.
PREVIOUS DISCUSSION FOLLOWS...
CALM AND DRY CONDITIONS WILL PREVAIL TONIGHT AS HIGH PRESSURE
STRENGTHENS OVER THE MIDWEST. DRIER AIR HAS BEEN STREAMING INTO
THE FORECAST AREA ALL DAY FROM THE NORTHWEST...AND WILL CONTINUE
TO THROUGH THE NIGHT. AS A RESULT...PARTLY CLOUDY SKIES CAN BE
EXPECTED TONIGHT WITH LOWS IN THE 20S DUE TO THE RADIATIONAL
COOLING. MODELS ARE IN AGREEMENT IN REGARD TO THE RADIATIONAL
COOLING...SO STUCK CLOSE TO GUIDANCE.
&&
.SHORT TERM /TOMORROW THROUGH SATURDAY/...
ISSUED AT 957 PM EST WED DEC 3 2014
BASED ON LATEST MODEL DATA...TEMPERATURES IN THE SOUTHERN FORECAST
AREA MAY RISE A BIT FASTER THAN THOUGHT ON THURSDAY MORNING. THUS
CHANGED PRECIPITATION TYPE TO FREEZING RAIN OR RAIN FOR NOW.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE SHORT TERM PERIOD WILL BE PRECIP CHANCES AND
TYPES WITH FRONTAL BOUNDARY TO THE SOUTH.
PRECIP WILL OVERSPREAD CENTRAL INDIANA FROM THE SOUTHWEST TO
NORTHEAST STARTING TOMORROW MORNING AS ISENTROPIC LIFT STRENGTHENS
OVER THE MID MISSISSIPPI VALLEY. THE MAIN CHALLENGE DURING THIS
PERIOD WILL BE PRECIP TYPE. A BRIEF PERIOD OF FREEZING RAIN OVER
THE SOUTHERN COUNTIES WILL BE POSSIBLE EARLY THURSDAY
MORNING...BUT THIS WILL QUICKLY TRANSITION TO RAIN BY MID MORNING
AS TEMPERATURES INCREASE. RAIN WILL CONTINUE THROUGH THE DAY...BUT
IT WILL BECOME A LITTLE TRICKY OVERNIGHT. MODELS ARE TRENDING
TOWARD SOME WEAK WARM ADVECTION FROM THE SOUTH ON THURSDAY
NIGHT...BUT CONFIDENCE IS LOW IN REGARD TO HOW FAR NORTH THAT WARM
AIR WILL TRAVEL. SO...WILL MENTION FREEZING RAIN OVER THE NORTHERN
COUNTIES LATE THURSDAY NIGHT WHERE TEMPS WILL HOVER AROUND THE
FREEZING MARK. FORECAST SOUNDINGS ARE INDICATING WARM ENOUGH AIR
FOR RAIN OVER THE REMAINDER OF THE FORECAST AREA THOUGH.
PRECIP CHANCES WILL INCREASE FURTHER ON FRIDAY AS AN UPPER LEVEL
LOW MOVES THROUGH THE MISSOURI VALLEY AND COMBINES WITH SURFACE
FRONTAL BOUNDARY EXTENDING FROM THE DEEP SOUTH TO THE OHIO VALLEY.
THESE DYNAMICS SUPPORT POPS NEAR 100 PERCENT ON FRIDAY AND FRIDAY
NIGHT. AS LIFT WEAKENS ON SATURDAY...RAIN WILL TAPER OFF FROM
WEST TO EAST ACROSS CENTRAL INDIANA.
TEMPS...CENTRAL INDIANA WILL BE RIGHT ALONG FRONTAL BOUNDARY FOR
DURATION OF SHORT TERM PERIOD. AGAIN...WEAK WARM ADVECTION WILL
HELP KEEP HIGH TEMPS IN THE 40S...AND LOWS IN THE 30S. THIS WAS
CAPTURED BEST WITH A MODEL BLEND.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 230 AM EST THU DEC 4 2014
BROAD HIGH PRESSURE WILL BRING DRY COOL CONDITIONS ON SUNDAY IN
THE WAKE OF THE FRIDAY/SATURDAY SYSTEM. THE HIGH WILL SHIFT EAST
QUICKLY SUNDAY NIGHT...WITH AN UPPER WAVE AND ASSOCIATED LOW
PRESSURE SYSTEM TRACKING INTO THE GREAT LAKES FROM THE NORTHERN
PLAINS ON MONDAY. THE GLOBAL MODELS HAVE BEEN MORE AMPLIFIED WITH
THE UPPER FLOW PATTERN...AND CONSEQUENTLY BRING THE UPPER WAVE
FURTHER SOUTH INTO THE OHIO VALLEY. CONSIDERING THE RIDGING
EXPECTED TO DEVELOP OVER THE INTERMOUNTAIN WEST AHEAD OF STRONG
LOW PRESSURE INTO THE GULF OF ALASKA...THE MORE AMPLIFIED PATTERN
ALOFT SUGGESTED BY THE GLOBALS IS MORE REALISTIC AND PREFERRED AT
THIS TIME. HAVE INCREASED POPS SLIGHTLY OVER SUPERBLEND GUIDANCE
FOR MONDAY AND MONDAY NIGHT AS THE UPPER WAVE PASSES THROUGH THE
REGION...WITH LIGHT RAIN CHANGING TO LIGHT SNOW AS COLDER AIR
ARRIVES.
REMAINDER OF THE EXTENDED LOOKS QUIET AS A DRY NORTHWEST FLOW
ALOFT DEVELOPS WITH HIGH PRESSURE AT THE SURFACE. GLOBAL GUIDANCE
IS PREFERRED THROUGH THE END OF THE LONG TERM AS OP GFS CONTINUES
TO FAVOR A MUCH FLATTER AND MORE PROGRESSIVE FLOW PATTERN ALOFT
AND IS OUT OF STEP WITH MOST OF THE OTHER EXTENDED GUIDANCE.
UNDERCUT SUPERBLEND FOR TEMPS THROUGHOUT...WITH HIGHS PRIMARILY
RANGING FROM THE UPPER 30S TO MID 40S AND LOWS IN THE 20S TO LOWER
30S.
&&
.AVIATION /DISCUSSION FOR 040600Z TAF ISSUANCE/...
ISSUED AT 1245 AM EST THU DEC 4 2014
VFR CONDITIONS EXPECTED THROUGH THIS MORNING...DETERIORATING
CONDITIONS THIS AFTERNOON AND EVENING WITH PRECIPITATION.
HIGH CLOUDS CONTINUE TO INCREASE EARLY THIS MORNING AS MOISTURE
ALOFT SPREADS INTO THE REGION. LIGHT WINDS WILL GRADUALLY
SET UP FROM THE NORTHEAST LATE TONIGHT AS A FRONTAL BOUNDARY MOVES
INTO THE TENNESSEE VALLEY. LIGHT PRECIPITATION WILL EXPAND
NORTHEAST THROUGH THE LOWER OHIO VALLEY AND INTO CENTRAL INDIANA
DURING THE MORNING. HI RES WRF-ARW AND NMM ALONG WITH THE HRRR ALL
BRING LIGHT PRECIP INTO THE I-70 CORRIDOR BY LATE MORNING. HAVE
BUMPED UP VCSH MENTION AT KBMG/HUF/KIND BETWEEN 12-14Z WITH
PREVAILING LIGHT RAIN DEVELOPING AT ALL SITES BY LATE MORNING. IN
ADDITION WITH COLDER NEAR SURFACE AIR PRESENT IN THE MORNING...MAY
SEE A BRIEF PERIOD OF LIGHT FREEZING DRIZZLE/RAIN AT THE ONSET AT
BOTH KBMG AND KHUF BEFORE WARMING ENOUGH TO SUPPORT RAIN. WILL
CONTINUE TO MONITOR SURFACE TEMP TRENDS OVER THE NEXT FEW HOURS.
MODEL SOUNDINGS INDICATE DRIER AIR WITHIN THE BOUNDARY LAYER WILL
BE SLOW TO SHIFT NORTH WHICH MAY LIMIT PRECIP INITIALLY...BUT
STRONGER SURGE OF ISENTROPIC LIFT DURING THE AFTERNOON SHOULD
ALLOW LOWER MVFR CEILINGS TO EXPAND NORTH. CEILINGS WILL SETTLE
BETWEEN 1500-2000FT BY THE EVENING WITH LOWER VISIBILITIES IN
SCATTERED LIGHT SHOWERS AND/OR DRIZZLE. EASTERLY WINDS AT 5-10KTS
ARE EXPECTED FOR MUCH OF THE DAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD/50
SHORT TERM...TDUD/50
LONG TERM....RYAN
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1245 AM EST THU DEC 4 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 317 PM EST WED DEC 3 2014
HIGH PRESSURE WILL BRING DRY CONDITIONS TO CENTRAL INDIANA TODAY
AND TONIGHT. HOWEVER...RAIN/FREEZING RAIN WILL BE BACK IN THE
FORECAST BY THURSDAY AS MOISTURE INCREASES AHEAD OF A FRONTAL
BOUNDARY TO THE SOUTH. THIS SURFACE FRONTAL BOUNDARY WILL COMBINE
WITH AN UPPER LEVEL TROUGH BY FRIDAY NIGHT TO PRODUCE WIDESPREAD
RAIN INTO SATURDAY. AFTER THAT...A DRY PERIOD WILL RETURN FOR THE
SECOND HALF OF THE WEEKEND. FURTHER OUT...A STRONG UPPER LEVEL LOW
IS PROGGED TO AFFECT THE AREA ON MONDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 957 PM EST WED DEC 3 2014
TEMPERATURES DROPPED QUICKLY THIS EVENING WHERE CIRRUS THINNED
OUT...BUT SATELLITE SHOWS THICKER CIRRUS MOVING INTO THE AREA AT THE
MOMENT. THUS DO NOT EXPECT TEMPERATURES TO FALL AS FAST...AND THEY
MAY LEVEL OFF IN SOME AREAS WHERE CIRRUS IS THICKEST.
THUS MADE NO CHANGES TO LOW TEMPERATURES...BUT DID ADJUST HOURLY
READINGS TO REFLECT CURRENT TRENDS. ADJUSTED SKY COVER UP SOME ALSO
BASED ON LATEST SATELLITE IMAGES. PRECIPITATION STILL LOOKS TO HOLD
OFF UNTIL AFTER 12Z.
PREVIOUS DISCUSSION FOLLOWS...
CALM AND DRY CONDITIONS WILL PREVAIL TONIGHT AS HIGH PRESSURE
STRENGTHENS OVER THE MIDWEST. DRIER AIR HAS BEEN STREAMING INTO
THE FORECAST AREA ALL DAY FROM THE NORTHWEST...AND WILL CONTINUE
TO THROUGH THE NIGHT. AS A RESULT...PARTLY CLOUDY SKIES CAN BE
EXPECTED TONIGHT WITH LOWS IN THE 20S DUE TO THE RADIATIONAL
COOLING. MODELS ARE IN AGREEMENT IN REGARD TO THE RADIATIONAL
COOLING...SO STUCK CLOSE TO GUIDANCE.
&&
.SHORT TERM /TOMORROW THROUGH SATURDAY/...
ISSUED AT 957 PM EST WED DEC 3 2014
BASED ON LATEST MODEL DATA...TEMPERATURES IN THE SOUTHERN FORECAST
AREA MAY RISE A BIT FASTER THAN THOUGHT ON THURSDAY MORNING. THUS
CHANGED PRECIPITATION TYPE TO FREEZING RAIN OR RAIN FOR NOW.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE SHORT TERM PERIOD WILL BE PRECIP CHANCES AND
TYPES WITH FRONTAL BOUNDARY TO THE SOUTH.
PRECIP WILL OVERSPREAD CENTRAL INDIANA FROM THE SOUTHWEST TO
NORTHEAST STARTING TOMORROW MORNING AS ISENTROPIC LIFT STRENGTHENS
OVER THE MID MISSISSIPPI VALLEY. THE MAIN CHALLENGE DURING THIS
PERIOD WILL BE PRECIP TYPE. A BRIEF PERIOD OF FREEZING RAIN OVER
THE SOUTHERN COUNTIES WILL BE POSSIBLE EARLY THURSDAY
MORNING...BUT THIS WILL QUICKLY TRANSITION TO RAIN BY MID MORNING
AS TEMPERATURES INCREASE. RAIN WILL CONTINUE THROUGH THE DAY...BUT
IT WILL BECOME A LITTLE TRICKY OVERNIGHT. MODELS ARE TRENDING
TOWARD SOME WEAK WARM ADVECTION FROM THE SOUTH ON THURSDAY
NIGHT...BUT CONFIDENCE IS LOW IN REGARD TO HOW FAR NORTH THAT WARM
AIR WILL TRAVEL. SO...WILL MENTION FREEZING RAIN OVER THE NORTHERN
COUNTIES LATE THURSDAY NIGHT WHERE TEMPS WILL HOVER AROUND THE
FREEZING MARK. FORECAST SOUNDINGS ARE INDICATING WARM ENOUGH AIR
FOR RAIN OVER THE REMAINDER OF THE FORECAST AREA THOUGH.
PRECIP CHANCES WILL INCREASE FURTHER ON FRIDAY AS AN UPPER LEVEL
LOW MOVES THROUGH THE MISSOURI VALLEY AND COMBINES WITH SURFACE
FRONTAL BOUNDARY EXTENDING FROM THE DEEP SOUTH TO THE OHIO VALLEY.
THESE DYNAMICS SUPPORT POPS NEAR 100 PERCENT ON FRIDAY AND FRIDAY
NIGHT. AS LIFT WEAKENS ON SATURDAY...RAIN WILL TAPER OFF FROM
WEST TO EAST ACROSS CENTRAL INDIANA.
TEMPS...CENTRAL INDIANA WILL BE RIGHT ALONG FRONTAL BOUNDARY FOR
DURATION OF SHORT TERM PERIOD. AGAIN...WEAK WARM ADVECTION WILL
HELP KEEP HIGH TEMPS IN THE 40S...AND LOWS IN THE 30S. THIS WAS
CAPTURED BEST WITH A MODEL BLEND.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 317 PM EST WED DEC 3 2014
THE LOW PRESSURE SYSTEM THAT WILL IMPACT OUR WEATHER FRIDAY INTO
SATURDAY WILL QUICKLY MOVE ON QUICKLY TO THE EAST SATURDAY NIGHT.
THE NEXT SYSTEM THAT WILL AFFECT OUR WEATHER IS A STRONG UPPER
TROUGH WHICH WILL MOVE ACROSS OUR REGION EARLY NEXT WEEK. THE EURO
AND GEMNH MODELS HAS THIS AS A CLOSED UPPER LOW...WHILE THE GFS
KEEPS IT AS A OPEN TROUGH. ALL MODELS GENERATE A LITTLE
PRECIPITATION AROUND MONDAY. THUS WILL ADD A CHANCE OF RAIN MAINLY
MONDAY. ON DAYS 6 AND 7 THE STRONG UPPER TROUGH WILL MOVE ON TO
THE EAST COAST AS A SURFACE HIGH PRESSURE SYSTEM OVER THE NORTHERN
PLAINS BUILDS INTO OUR REGION BY DAY 7.
TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL MOST OF THE PERIOD. BUT
THEY WILL BE NEAR NORMAL SUNDAY NIGHT. MADE ONLY A FEW TWEAKS TO A
MOS BLEND ON TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR 040600Z TAF ISSUANCE/...
ISSUED AT 1245 AM EST THU DEC 4 2014
VFR CONDITIONS EXPECTED THROUGH THIS MORNING...DETERIORATING
CONDITIONS THIS AFTERNOON AND EVENING WITH PRECIPITATION.
HIGH CLOUDS CONTINUE TO INCREASE EARLY THIS MORNING AS MOISTURE
ALOFT SPREADS INTO THE REGION. LIGHT WINDS WILL GRADUALLY
SET UP FROM THE NORTHEAST LATE TONIGHT AS A FRONTAL BOUNDARY MOVES
INTO THE TENNESSEE VALLEY. LIGHT PRECIPITATION WILL EXPAND
NORTHEAST THROUGH THE LOWER OHIO VALLEY AND INTO CENTRAL INDIANA
DURING THE MORNING. HI RES WRF-ARW AND NMM ALONG WITH THE HRRR ALL
BRING LIGHT PRECIP INTO THE I-70 CORRIDOR BY LATE MORNING. HAVE
BUMPED UP VCSH MENTION AT KBMG/HUF/KIND BETWEEN 12-14Z WITH
PREVAILING LIGHT RAIN DEVELOPING AT ALL SITES BY LATE MORNING. IN
ADDITION WITH COLDER NEAR SURFACE AIR PRESENT IN THE MORNING...MAY
SEE A BRIEF PERIOD OF LIGHT FREEZING DRIZZLE/RAIN AT THE ONSET AT
BOTH KBMG AND KHUF BEFORE WARMING ENOUGH TO SUPPORT RAIN. WILL
CONTINUE TO MONITOR SURFACE TEMP TRENDS OVER THE NEXT FEW HOURS.
MODEL SOUNDINGS INDICATE DRIER AIR WITHIN THE BOUNDARY LAYER WILL
BE SLOW TO SHIFT NORTH WHICH MAY LIMIT PRECIP INITIALLY...BUT
STRONGER SURGE OF ISENTROPIC LIFT DURING THE AFTERNOON SHOULD
ALLOW LOWER MVFR CEILINGS TO EXPAND NORTH. CEILINGS WILL SETTLE
BETWEEN 1500-2000FT BY THE EVENING WITH LOWER VISIBILITIES IN
SCATTERED LIGHT SHOWERS AND/OR DRIZZLE. EASTERLY WINDS AT 5-10KTS
ARE EXPECTED FOR MUCH OF THE DAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD/50
SHORT TERM...TDUD/50
LONG TERM....JH
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
517 AM CST THU DEC 4 2014
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 354 AM CST THU DEC 4 2014
AN UPPER LEVEL LOW WAS CENTERED NORTH OF HUDSON BAY WITH A
PROGRESSIVE TROUGH EXTENDING INTO MAINE THIS EVENING. A LARGE AREA
OF SURFACE HIGH PRESSURE CENTERED ALONG AN AXIS FROM WISCONSIN TO
WEST VIRGINIA COVERED MUCH OF THE EASTERN UNITED STATES. LOW LEVEL
MOISTURE FLOWING NORTH FROM THE GULF OF MEXICO ON THE WEST SIDE OF
THE LARGE AREA OF HIGH PRESSURE SPREAD INTO KANSAS DURING THE LATE
AFTERNOON AND EVENING HOURS, AND WIDESPREAD STRATUS COVERED MUCH
OF SOUTHWEST AND CENTRAL KANSAS. A WARM FRONT WAS EVIDENT AT 06Z
FROM A WEAK SURFACE LOW IN SOUTHWEST TEXAS TO NEAR THE RED RIVER
TO NORTHERN LOUISIANA. A MINOR UPPER LEVEL TROUGH EXTENDED FROM
EASTERN SOUTH DAKOTA INTO NORTHERN KANSAS, AND VEERED LOW LEVEL
WINDS ABOVE THE SURFACE WERE LIMITING THE NORTHWARD EXTENT OF THE
LOW LEVEL MOISTURE. A SPLIT IN THE WESTERLIES WAS EVIDENT IN THE
EASTERN PACIFIC WITH A RIDGE EXTENDING FROM THE BRITISH COLUMBIA
COAST INTO ALASKA AND AND AN ACTIVE SOUTHERN BRANCH JET FROM NEAR
170W THROUGH A MEAN TROUGH AROUND 125W TO THE CENTRAL PLAINS. A
VIGOROUS UPPER LEVEL TROUGH WAS EVIDENT IN SATELLITE IMAGERY NEAR
120W. AN UPPER LEVEL LOW WAS CENTERED WEST OF THE OREGON COAST
WITH SEVERAL MINOR TROUGHS ROTATING THROUGH THE PACIFIC NORTHWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CST THU DEC 4 2014
THE MOST SIGNIFICANT SHORT TERM CHALLENGES ARE !)ANTICIPATING THE
EXTENT OF FOG/FREEZING FOG EARLY THIS MORNING; 2) ANTICIPATING
COVERAGE OF RAINFALL THURSDAY NIGHT INTO EARLY FRIDAY; AND 3)
EVALUATING THE POSSIBILITY OF FOG FORMATION AGAIN FRIDAY MORNING AS
CLOUD COVER DECREASES AFTER THE RAIN WINDS DOWN.
THE DEEP UPPER LEVEL TROUGH MOVING THROUGH EASTERN CANADA WILL
CONTINUE TO PROPAGATE TOWARD GREENLAND, AND THE SURFACE HIGH
CENTERED IN THE UPPER MIDWEST WILL MOVE INTO NEW ENGLAND BY FRIDAY
MORNING. AN UPPER LEVEL RIDGE FROM BRITISH COLUMBIA COAST TO ALASKA
WILL MOVE LITTLE THROUGH THE WEEKEND. UPPER LEVEL TROUGHS EMBEDDED
IN THE SOUTHERN BRANCH OF THE WESTERLIES WILL CONTINUE TO MOVE
ACROSS THE SOUTHWESTERN UNITED STATES TOWARD THE CENTRAL PLAINS
UNTIL RIDGING AMPLIFIES IN THE WESTERN UNITED STATES AS A
PROGRESSIVE LONG WAVE TROUGH DEEPENS IN THE GULF OF ALASKA EARLY
NEXT WEEK. A MADDEN JULIAN OSCILLATION CENTERED NEAR THE MARITIME
CONTINENT WILL CONTINUE TO MOVE EAST INTO THE WESTERN HEMISPHERE
THROUGH MID DECEMBER, AND A LONG WAVE TROUGH LIKELY WILL PROPAGATE
INTO THE CENTRAL PART OF THE COUNTRY AS THE MADDEN JULIAN
OSCILLATION APPROACHES THE MID PACIFIC. AN EXTENDED PERIOD OF
RELATIVELY MILD WEATHER IS LIKELY IN THE CENTRAL PART OF THE COUNTRY
AT LEAST THROUGH 12-13 DECEMBER.
LOW LEVEL MOISTURE ADVECTING INTO THE CENTRAL PART OF THE COUNTRY ON
THE WEST SIDE OF THE AREA OF HIGH PRESSURE CENTERED IN THE UPPER
MIDWEST IS BEING LIFTED OVER A WARM FRONT NEAR THE RED RIVER, AND
WIDESPREAD STRATUS MOVED INTO KANSAS WEDNESDAY EVENING. RADIATIONAL
COOLING ON THE WESTERN EDGE OF THE STRATUS DECK ALLOWED SURFACE
TEMPERATURES TO FALL INTO THE UPPER 20S IN FAR WESTERN KANSAS, AND
ADVECTION OF AIR WITH DEWPOINTS IN THE LOWER 30S OVER THE COLD
GROUND HAS RESULTED IN FORMATION OF AREAS OF FOG. WITH CONTINUED
MOIST ADVECTION INTO FAR WESTERN KANSAS, LOCALLY DENSE FOG IS LIKELY
TO FORM AROUND SUNRISE AND TO PERSIST THROUGH AT LEAST MID MORNING.
THE STRONG SOUTHERN BRANCH UPPER LEVEL TROUGH NEAR 120W WILL MOVE
INTO WESTERN KANSAS TONIGHT. UPWARD VERTICAL MOTION IN ADVANCE OF
THE UPPER LEVEL TROUGH ALONG WITH ISENTROPIC LIFTING OVER THE
SHALLOW COOL AIR MASS IN KANSAS WILL SUPPORT DEVELOPMENT LIGHT RAIN
IN FAR SOUTHWEST KANSAS LATE THIS AFTERNOON. THE AREA OF RAIN
WILL BECOME WIDESPREAD TONIGHT AND WIND DOWN FRIDAY MORNING AS THE
UPPER LEVEL TROUGH MOVES INTO CENTRAL KANSAS AND SUBSIDENCE BEGINS
BEHIND THE TROUGH. A SURFACE CYCLONE WILL MOVE ALONG THE
BAROCLINIC ZONE EXTENDING ACROSS OKLAHOMA INTO MISSOURI AS THE
UPPER LEVEL TROUGH MOVES EAST, AND LOW LEVEL WINDS WILL BECOME
NORTH BY FRIDAY MORNING. TEMPERATURES BEHIND THE WIND SHIFT FRIDAY
WILL BE HIGHER THAN VALUES OBSERVED TODAY SINCE THE NORTH WINDS
WILL ADVECT AIR WARMED BY DOWNSLOPE IN THE NORTHERN ROCKIES INTO
WESTERN KANSAS.
TEMPERATURES TODAY WILL BE HIGHLY DEPENDENT OF CLOUD COVER. HIGHS
WILL BE RESTRICTED TO THE MID 40S IN AREAS WHERE THE STRATUS IS MOST
PERSISTENT BUT LIKELY WILL RISE INTO THE MID 50S NEAR THE COLORADO
BORDER. CLOUDINESS WILL INCREASE BY EARLY AFTERNOON AS MOISTURE IN
ADVANCE OF THE UPPER LEVEL TROUGH MOVES INTO THE CENTRAL PLAINS.
TEMPERATURES TONIGHT SHOULD BE RELATIVELY MILD WITH CLOUDY SKIES AND
WIDESPREAD WARM RAIN. AREAS OF FOG MAY FORM AGAIN FRIDAY MORNING
NEAR THE WEST EDGE OF THE RAIN SHIELD WHERE CLOUDINESS WILL DECREASE
AROUND SUNRISE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 302 AM CST THU DEC 4 2014
PRECIPITATION CHANCES WILL CONTINUE TO TAPER OFF FROM WEST TO
EAST EARLY FRIDAY AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL
PLAINS. A SURFACE BOUNDARY WILL ALSO SLIDE EAST ACROSS WESTERN
KANSAS EARLY IN THE DAY AND DOWNSLOPE FLOW WILL BE IMPROVING
DURING THE DAY. GIVEN THE WARMING FORECAST IN THE 900 TO 800MB
LEVEL THE PREVIOUS SHIFT STILL LOOKS ON TRACK WITH HIGHS CLIMBING
INTO THE 50S FRIDAY AFTERNOON. DEPENDING ON AMOUNT OF SUN
DEVELOPING ACROSS FAR WESTERN KANSAS HIGHS AROUND 60 ARE NOT OUT
OF THE QUESTION.
ON SATURDAY AN UPPER LEVEL RIDGE AXIS WILL SLIDE EAST ACROSS
ACROSS THE CENTRAL AND NORTHERN PLAINS AS AN UPPER LEVEL TROUGH
APPROACHES THE SOUTHERN AND CENTRAL ROCKIES. THIS NEXT UPPER LEVEL
SYSTEM IS CURRENTLY EXPECTED TO CROSS THE CENTRAL HIGH PLAINS ON
SATURDAY NIGHT INTO EARLY SUNDAY WITH THE GFS HINTING AT SOME
PRECIPITATION DEVELOPING AS THIS SYSTEM CROSSES WESTERN KANSAS.
ECMWF IS LESS EXCITED WITH THE PRECIPITATION CHANCES AND GIVEN
MAINLY MID LEVEL MOISTURE WILL BE PRESENT AHEAD OF THIS SYSTEM SO
AT THIS TIME WILL LEAN TOWARDS MORE CLOUDS THAN PRECIPITATION.
MODELS THIS MORNING DIFFERING ON AN UPPER LEVEL SYSTEM AS IT
CROSSES THE NORTHERN PLAINS SUNDAY NIGHT AND MONDAY AND HOW MUCH
COOLING THAT WILL OCCUR BEHIND A COLD FRONT CROSSING THE CENTRAL
PLAINS EARLY NEXT WEEK. AT THIS TIME GIVEN THAT THIS SYSTEM WAS
LOCATED OUT NEAR 45N 150W CONFIDENCE IS NOT HIGH ON HOW THIS UPPER
WAVE WILL EVOLVE AS IT CROSSES THE NORTHWEST UNITED STATES. HOW
MUCH THE DOWNSLOPE FLOW WILL IMPACT THE COOLING BEHIND THE FRONT
IS ALSO WILL THEREFORE STAY CLOSE TO WHAT THE LATEST
CREXTENDEDFCST_INIT HAS GOING FOR TEMPERATURES AND PRECIPITATION
CHANCES MONDAY AND TUESDAY.
ANOTHER UPPER LEVEL SYSTEM WILL APPROACH THE WEST COAST MID TO
LATE WEEK AND RIDGING ALOFT ALONG WITH IMPROVING WESTERLY
DOWNSLOPE FLOW WILL DEVELOP ACROSS THE CENTRAL HIGH PLAINS. THIS
SUPPORTS THE PREVIOUS FORECAST WITH A GRADUALLY WARMING TREND MID
TO LATE WEEK WITH TEMPERATURES WARMING THROUGH THE 50S AND EVEN
SOME LOW TO MID 60S BEING POSSIBLE BY THE END OF THE WORK WEEK IF
THE 850MB TEMPERATURE TREND FROM THE GFS VERIFIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 514 AM CST THU DEC 4 2014
IFR AND MVFR CEILINGS IN SOUTHWEST KANSAS WILL BE SLOW TO IMPROVE
TODAY GIVEN THE THICKNESS OF THE LOW LEVEL MOISTURE FROM THE BUFR
SOUNDINGS AND THE MID AND HIGH LEVEL CLOUD COVER PRECEDING AND
UPPER LEVEL TROUGH WHICH WILL BE MOVING ACROSS THE SOUTHWEST
UNITED STATES. USING NAM BUFR SOUNDINGS ALONG WITH THE RAP AND
HRRR AS A GUIDE THE CEILINGS WILL SLOWLY IMPROVE INTO THE MVFR
CATEGORY BETWEEN 15Z AND 18Z AT GCK AND DDC. VFR CONDITIONS WILL
THEN DEVELOP AT GCK BETWEEN 18Z AND 21Z WHILE DDC IS FORECAST TO
REMAIN IN THE MVFR CATEGORY THROUGH 00Z FRIDAY. AFTER 00Z FRIDAY
CEILINGS ARE EXPECTED TO LOWER BACK INTO THE IFR CATEGORY WITH
LIGHT RAIN AND FOG DEVELOPING. LIGHT RAIN IS EXPECTED TO DEVELOP
AT DDC AND GCK BY 03Z FRIDAY. PRECIPITATION WILL BEGIN TO MOVE
INTO HYS TOWARDS 06Z. SOUTHERLY WINDS WILL BE AT 10 KNOTS OR LESS
TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 39 55 28 / 20 80 20 0
GCK 50 36 57 27 / 20 80 0 0
EHA 54 37 59 30 / 50 70 0 0
LBL 50 39 59 29 / 50 80 0 0
HYS 50 37 54 26 / 0 70 30 0
P28 49 44 54 32 / 30 90 50 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
KSZ061-062-074-075-084-085.
&&
$$
SYNOPSIS...RUTHI
SHORT TERM...RUTHI
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1043 PM MST WED DEC 3 2014
.UPDATE...
ISSUED AT 550 PM MST WED DEC 3 2014
LARGE AREA OF STRATUS IS MOVING IN FROM SOUTH CENTRAL AND
SOUTHWEST KANSAS. MODELS DIFFER A LITTLE ON FAR NORTH AND WEST TO
TAKE THE HIGHER LOW LEVEL MOISTURE. RIGHT NOW IT LOOKS LIKE THE
RAP AND HRRR IS CATCHING THIS THE BEST. SO INCREASED CLOUD COVER
TO ACCOUNT FOR THIS FOR TONIGHT INTO TOMORROW MORNING.
MODELS ALSO DIFFER ON IF OR HOW MUCH FOG THERE WILL BE. THE NAM
KEEPS IT SOUTH OF MY AREA. HOWEVER...THE RAP AND ESPECIALLY THE
HRRR BRING AN AREA OF FOG...MAINLY ALONG AND EAST OF THE COLORADO
BORDER. THIS IS FURTHER WEST THAN WHAT WAS EARLIER EXPECTED. ALSO
THE HRRR WOULD SUPPORT SOME DENSE FOG. AM NOT TOTALLY CONVINCED
ABOUT THIS. THE DEWPOINTS ARE STILL RATHER LOW SOUTH OF US AND
WILL NEED TO CLIMB A LOT TO REACH SATURATION. SO AT THIS TIME ONLY
INSERTED PATCHY FOG AND WILL CONTINUE TO MONITOR MODEL/OBSERVATION
TRENDS. ANOTHER UPDATE MAY BE NEEDED.
RAISED MINS A LITTLE...MAINLY THE SOUTHERN PORTION...WHERE THE
CLOUD COVER COMES IN THE EARLIEST. DEPENDING ON HOW FAST THIS
MOVES IN...I MAY NEED TO RAISE THE TEMPERATURES MORE.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 1252 PM MST WED DEC 3 2014
UPPER FLOW WILL BE ZONAL THROUGH THURSDAY. A SURFACE HIGH WILL DRIFT
EAST THURSDAY WITH A TROUGH IN EASTERN COLORADO. POPS WILL BE NIL
TONIGHT AND THURSDAY DUE TO SUBSIDENCE. SOUTH WIND WILL BECOME LIGHT
AND VARIABLE THURSDAY.
SOUTH WINDS WILL ADVECT IN HIGHER BOUNDARY LAYER RELATIVE HUMIDITY
INTO THE SOUTHERN FA FROM AROUND 09Z TO 15Z. PLAN TO INSERT SOME
PATCHY FOG INTO THE FORECAST FOR THAT AREA OVERNIGHT AND THURSDAY
MORNING.
850MB TEMPERATURES RISE TO AROUND 10C IN THE WESTERN FA ON THURSDAY.
WITH LOTS OF SUN, MAX TEMPERATURES SHOULD REACH THE MID 50S IN THE
WESTERN FA AND AROUND 50 IN THE EASTERN FA. MIN TEMPERATURES SHOULD
COOL TO AROUND 20 TONIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1252 PM MST WED DEC 3 2014
MODELS A LITTLE MORE ROBUST WITH SHORTWAVE TROUGH COMING OUT OF
THE FOUR CORNERS REGION THURSDAY NIGHT AND ASSOCIATED LIGHT
PRECIPITATION SHIELD. TEMPERATURE PROFILES SHOW IT WILL BE ALL
RAIN. SURFACE WET BULB TEMPERATURES WILL REMAIN IN THE UPPER 30S
TO LOWER 40S ACROSS NORTHWEST KANSAS WHICH SHOULD BE WARM ENOUGH
TO EXCLUDE THE POSSIBILITY OF FREEZING PRECIPITATION. BUMPED UP
POPS AND OVERNIGHT LOW TEMPERATURES...BOTH COULD BE NUDGED UP A
LITTLE MORE IF TRENDS CONTINUE. QPF WILL BE LESS THAN A TENTH OF
AN INCH. PRECIPITATION SHOULD BE DONE BY EARLY FRIDAY MORNING AS
THE SYSTEM QUICKLY MOVES EAST.
SHORTWAVE RIDGING WILL MOVE ACROSS THE REGION FRIDAY AND SATURDAY
WITH DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES. A COUPLE OF
DISTURBANCES COME OUT OF THE ROCKIES SATURDAY NIGHT AND SUNDAY.
MODELS REMAIN DRY AT THIS POINT BUT CAN NOT TOTAL RULE OUT SOME
LIGHT RAIN OR SPRINKLES. THE FIRST HALF OF NEXT WEEK WILL FEATURE
A LARGE RIDGE BUILDING OVER THE GREAT BASIN AND GRADUALLY
SPREADING EASTWARD TOWARDS THE ROCKIES. MODELS HINT AT ANOTHER
POSSIBLE WEAK SYSTEM COMING OVER THE RIDGE AROUND MID WEEK BUT
MOISTURE WILL BE SPARSE AND PRECIPITATION CHANCES SLIM. THERE IS
NO COLD AIR IN SIGHT WITH TEMPERATURES REMAINING SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1038 PM MST WED DEC 3 2014
LATEST MESOSCALE MODEL GUIDANCE HAS BACKED OFF ON STRATUS AND
ESPECIALLY FOG COVERAGE. TEMPERATURE AND DEWPOINT SPREADS REMAIN
RATHER HIGH TO OUR SOUTH. WITH NO SIGNIFICANT LOW LEVEL MOISTURE
ADVECTION EXPECTED AND THICK MID/UPPER LEVEL CLOUD COVER...IT
LOOKS LIKE THE MVFR CONDITIONS WILL STAY SOUTH AND EAST OF BOTH
TAF SITES. DID INCLUDE A SCATTERED LOW CLOUD DECK AT KGLD UNTIL
12Z.
SOME PRECIPITATION IS EXPECTED TO DEVELOP THURSDAY NIGHT BUT
LOOKS TO STILL BE SOUTH OF THE PERIOD BY THE END OF THIS PERIOD.
OTHERWISE WINDS WILL BE LIGHT AND SHIFTING THROUGH THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...FS
LONG TERM...024
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
856 PM CST FRI DEC 5 2014
.DISCUSSION...
FRONTAL BOUNDARY AS OF 8 PM WAS ORIENTED NEAR A FYV...FSM...
PRX...SEP LINE MOVING SLOWLY SOUTH AND EAST. A NARROW LINE OF
MOSTLY SHOWERS HAD DEVELOPED ALONG AND JUST AHEAD OF THIS BOUNDARY
ACROSS PORTIONS OF CENTRAL/SW AR INTO EXTREME SE OK AND PORTIONS
OF NE TX. THIS LINE LOOKED A LITTLE BETTER A COUPLE OF HOURS AGO
BUT WITH THE LOSS OF DAYTIME HEATING AND INSTABILITY LOOKING VERY
WEAK...NOT EXPECTING MUCH IN THE OF CONVECTION BUT CANNOT RULE
OUT AN ISOLATED LIGHTNING STRIKE THROUGHOUT THE NIGHT.
FRONT IS EXPECTED TO BE NEAR THE I-30 CORRIDOR BY MIDNIGHT AND
JUST EAST OF A LFK...SHV...ELD LINE BY 12Z IN THE MORNING. FOR THE
UPDATE...HAVE ORIENTED POPS HIGHEST ACROSS OUR EASTERN MOST ZONES
FOR THE REMAINDER OF THE NIGHT. THIS IS IN GOOD OVERALL AGREEMENT
WITH THE HRRR AND THE 00Z NAM OUTPUT WHICH PUTS THE BEST QPF
PROBABILITIES WHERE THE HIGHER MOISTURE CONTENT RESIDES.
ALSO ADDED THE LIKELIHOOD OF PATCHY DENSE FOG ACROSS ALL BUT OUR
EXTREME NW ZONES. TEMP/DEWPOINT DEPRESSIONS ARE VERY LOW ATTM AND
WITH THE VERY MOIST LOW LEVEL ATMOSPHERE PRESENT...UNTIL THE FRONT
COMES THROUGH...FOG IS A PRETTY GOOD BET OVERNIGHT.
NO ADDITIONAL CHANGES WERE NECESSARY THIS EVENING...UPDATE OUT
SHORTLY...13.
&&
.PREV DISCUSSION... /ISSUED 611 PM CST FRI DEC 5 2014/
AVIATION...
FOR THE 06/00Z TAFS...A FEW SHWRS CONTINUE TO AFFECT MLU EARLY
THIS EVENING BUT WILL SLOWLY TAPER OFF WITHIN THE NEXT FEW HOURS.
MEANWHILE...A COLD FRONT IS BEGINNING TO ENTER THE FAR NW EDGE OF
OUR REGION WITH A THIN LINE OF SHWRS ALONG THE BNDRY. THIS FRONT
WILL CONTINUE TO MOVE ACROSS THE REGION OVERNIGHT INTO SATURDAY
MORNING WITH MVFR/IFR CIGS AND VSBYS ALONG WITH SHWRS NEAR FROPA.
LOW CIGS WILL LINGER THROUGH AT LEAST LATE MORNING AND POSSIBLY
EARLY AFTERNOON ON SATURDAY. LIGHT SOUTH WINDS AHEAD OF THE FRONT
WILL QUICKLY SHIFT N/NW BEHIND THE FRONT WITH SPEEDS NEAR 10 KTS.
/19/
.PRELIMINARY POINT TEMPS/POPS...
SHV 62 68 43 54 42 / 40 0 0 10 10
MLU 62 68 42 55 41 / 50 10 0 10 10
DEQ 52 61 39 49 38 / 10 0 0 10 10
TXK 55 64 41 51 39 / 30 0 0 10 10
ELD 58 68 41 51 39 / 50 0 0 10 10
TYR 55 66 45 55 42 / 20 0 0 20 20
GGG 57 68 43 54 42 / 20 0 0 10 10
LFK 62 71 48 57 46 / 20 10 10 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19/13
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
253 PM EST THU DEC 4 2014
.SYNOPSIS...
HIGH PRESSURE LINGERS ALONG THE NORTHEASTERN SEABOARD THROUGH
FRIDAY. LOW PRESSURE DRIFTS EAST ACROSS FROM THE MID-SOUTH STATES
FRIDAY NIGHT AND ACROSS THE MID- ATLANTIC SATURDAY. MORE HIGH
PRESSURE IS EXPECTED NORTH OF THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
THE LEADING OF A REGIONAL-SCALE BATCH OF RAIN NOW SLIDING INTO THE
WINDWARD SIDES OF THE SRN/CNTRL APLCNS. HIGH PRESSURE TO OUR NORTH
WILL ACTUALLY STRENGTHEN AS IT MOVES EAST...FROM THE GREAT LAKES TO
NEW ENGLAND THIS EVE INTO EARLY FRI. THIS FEATURE WILL HELP TO
USHER-IN ANOTHER WEAK CAD SITUATION W/ INCOMING OVERRUNNING PRECIP
FROM THE WEST. THE PRECIP HOWEVER IS NOT ASSOCIATED W/ A LOW
PRESSURE SYSTEM...MERELY A MINOR UPPER WAVE CAUGHT IN THE ZONAL
UPPER PATTERN. THE MOISTURE LARGELY WAS DRAWN FROM THE GULF COAST
REGION AND WILL WANE IN THE COMING HRS AS THE FORCING WEAKENS.
TEMPS WILL HOVER IN THE 40S FOR MUCH OF THE AREA AND ONLY DROPPING
TO THE U30S EVEN ACROSS THE HIGHER TERRAIN AS RAIN APPROACHES AND
AFFECTS THE WRN HALF OF THE AREA. LATEST RUNS OF THE HRRR BRING IN
SEVERAL WAVES OF LIGHT RAIN OVER THE WRN ZONES OF THE APLCNS BUT
DISSIPATE MUCH OF THE ACTIVITY THAT ATTEMPTS TO REACH OR CROSS THE
NRN VA BLUE RIDGE. EVEN THOUGH YESTERDAY WAS A FAIRLY HUMID DAY IN
TERMS OF LOW LEVEL MOISTURE...A LARGE REGION OF DRY AIR IS MOVING
OVERHEAD - AS INDICATED BY THE 12Z KIAD SOUNDING. BELOW 850MB...
SUBSTANTIALLY LESS DRY BUT CONSIDERING THE INCOMING CIG HEIGHTS ARE
MOSTLY ABOVE 10KFT...IT WILL TAKE A WHILE FOR THE BOUNDARY LAYER TO
SATURATE AND FOR PRECIP TO REACH THE SFC.
BECAUSE OF THE RELATIVE WEAKNESS OF THE INCOMING WAVE...NOT
ANTICIPATING A GOOD COLD AIR SURGE FROM THE NORTH. A MORE POTENT LOW
PRES SYSTEM WILL BE GEARING UP EVEN FURTHER BACK TO OUR WEST TONIGHT
INTO TMRW...BUT NOT CLOSE ENOUGH TO MAXIMIZE THE CAD ABILITIES OF
THE NEW ENGLAND 1040MB HIGH. SOME IN-SITU DAMMING WILL BEGIN LATER
TONIGHT THAT WILL ALLOW TEMPS TO DECREASE TOWARD THE FREEZING MARK
BUT NOT QUITE GET THERE FOR MUCH OF THE AREA BY EARLY FRI MRNG.
LOOKING THRU AREA FORECAST SOUNDINGS USING 12Z GUIDANCE...NAM/GFS
BOTH INDICATE THE WARM NOSE FAIRLY ELEVATED - IN THE 5-8KFT RANGE
AND ALSO A POCKET OF DRIER AIR BELOW THE INVERSION THAT HANGS-IN
THRU MID MRNG MON.
LOW CONFIDENCE IN THE FREEZING RAIN POTENTIAL FOR SPECIFIC LOCATIONS
AND TIMING. NO HEADLINES FOR THIS UPCOMING FORECAST UPDATE...W/ AN
EMPHASIS ON A LIGHT WINTRY MIX FOR THE HIGHER TERRAIN INTO THE
OVERNIGHT HRS. HEADING INTO THE PREDAWN HRS...ONLY POCKETS OF FZRA
ARE EXPECTED AND MAINLY IN A SHALLOW LAYER FOR SPECIFIED HIGHER
RIDGELINES IN THE POTOMAC HIGHLANDS AND POSSIBLY SOME SHELTERED VLYS
W/ COLD AIR TRAPPING. MAY HAVE SUPER-COOLED RAIN IN THE ABSENCE OF A
STRONGER COLD/DRY PUSH FROM THE NORTH. THE INCOMING PRECIP ALSO
LOOKS TO BE VERY LIGHT AND INTERMITTENT AS THE FORCING FOR THE
PRECIP TAPERS OFF INTO THE EARLY MRNG HRS. WILL MONITOR THE INCOMING
PRECIP...TEMP TRENDS...AND NEWER GUIDANCE FOR POTENTIAL WINTER
HEADLINES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WV OF LOPRES IN THE MID OHVLY SAT MRNG WL MARCH ACRS THE CWFA DURING
THE DAY. ECMWF TRENDING SLOWER/FURTHER S THAN CONSENSUS. WL NOT BE
JUMPING ON BOARD YET. INSTEAD...KEEPING FCST MID-PACK. REGARDLESS...
SAT LOOKING LIKE A WET DAY FOR AREA AS 40 KT H8 FLOW AHD OF LOW WL
SUPPLY NOT ONLY MSTR BUT THTE RDG/UPGLIDE TO WRING IT OUT. CAT POPS
AREAWIDE...SPCLY E WHERE LLJ RESIDES.
CFP SAT LT AFTN-EVE. DRY AIR CRASHES IN BEHIND...WHICH MEANS WL ALSO
HV SOME GUSTY WINDS. UPSLP POTL DOESNT LOOK THAT GREAT EITHER. CAN
SEE CLDS BANKING UP AGAINST THE WRN SLOPES...BUT COLUMN TOO
DRY/INVSN COMES TOO QUICK FOR PCPN. WL KEEP 20-25 KT GUSTS SAT
NGT...AND KEEP IT BREEZY INTO SUN.
HIPRES WL BLD SUN. ECMWF ONCE AGN SLOWER THAN GFS IN CLRG.
COMPROMISED A LTL DURING THE MRNG...OTRW WL HV A MOSUN-SUNNY DAY.
DUE TO TRACK OF LOW...DONT THINK WE/LL HV A CAD WEDGE TO DEAL
WITH...AND RAISED MAXT SAT INTO LWR 50S. STILL WONT BE A PLEASANT
DAY...JUST NOT AS COOL/RAW. LTLCG NCSRY SAT NGT-SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DRY...COLDER AIRMASS WILL BUILD OVER THE MID ATLANTIC REGION
SUNDAY NIGHT. ON MONDAY THERE IS A SLIGHT CHANCE OF LIGHT RAIN
RETURNING AS THE SURFACE LOW STARTS MOVING TOWARD EASTERN CANADA.
CHANCE OF PRECIPITATION WILL INCREASE MONDAY NIGHT THHROUGH
TUESDAY WHEN AN STRONG SHORTWAVE CROSSES THE AREA. MAY BE ENOUGH
COLD AIR IN PLACE TO SUPPORT SCATTERED LIGHT WINTRY MIX WEST OF
THE BLUE RIDGE MONDAY NIGHT INTO TUESDAY MORNING.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
DENSE HIGH CLOUDS NOW OVERHEAD AND WILL CONTINUE TO BUILD FOR THE
COMING HRS THIS EVE. A FEW BATCHES OF RAIN WILL WORK THEIR WAY OVER
THE APLCNS AND TOWARD THE WRN DC SUBURBS BUT LARGELY DISSIPATE
BEFORE REACHING THE BLUE RIDGE. CIGS WILL CONTINUE TO DROP OVER THE
COURSE OF THE EVE/NIGHTTIME HRS BUT STAY W/IN VFR RANGES TO HIGH-END
MVFR BRIEFLY DURING THE PREDAWN FRI MRNG. HIGH PRESSURE MOVING NORTH
OF THE AREA WILL TURN SFC FLOW TO A MORE ELY DIRECTION THRU THE NEXT
SEVERAL HRS AND ESPEC INTO FRI MRNG. TEMPS WILL DROP BACK DOWN INTO
THE MIDDLE 30S FOR MOST AREAS OVERNIGHT AND ROUGHLY THE SAME
CONDITIONS FOR FRI AFTN W/ MORE RAIN SHOWERS MOVING IN FROM THE
WEST.
OUTLOOK...
SAT...MVFR-IFR CONDS LKLY AS LOPRES TRACKS OVER TERMINALS.
SUN-MON...VFR
TUE...MVFR PSBL.
&&
.MARINE...
A STRENGTHENING HIGH WELL TO OUR NORTH HAS DROPPED OFF WINDS TO A
LIGHT/VRB REGIME THIS AFTN AND WILL SWITCH THEM TO ELY OVERNIGHT
INTO FRI. SCA CONDITIONS NOT ANTICIPATED INTO FRI...W/ MORE RAIN
ARRIVING BY FRI AFTN/EVE.
SLY WINDS SAT AS LOPRES PASSES NEWD JUST W OF WATERS. WNDS WUD BE
GRADIENT DRIVEN. ATTM...THAT LOOKS TO BE BELOW SCA THRESHOLDS.
HWVR...THE GRADIENT WUD BE INCRSG SAT NGT IN THE WAKE OF THE LOW W/
A BETTER MIXED PROFILE AS WELL. SCA CONDS SEEMS LKLY SAT NGT...CONTG
INTO SUN. HV KEPT GRIDS BELOW GLW CRITERIA. GFS SUGGESTING OTRW.
WINDS WL BE RELAXING THRU SUN AFTN-EVE AS HIPRES BLDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HTS
NEAR TERM...GMS
SHORT TERM...HTS
LONG TERM...CEM
AVIATION...GMS/HTS
MARINE...GMS/HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
310 AM EST THU DEC 4 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 338 PM EST WED DEC 3 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR TROF
CENTERED FM HUDSON BAY INTO THE GREAT LKS DOWNSTREAM OF A RDG OVER
WRN CANADA. SHRTWV EMBEDDED WITHIN THE NW FLOW ALF IS TRACKING THRU
ONTARIO AND DRAGGING A COLD FNT THRU THE UPR LKS. WNW FLOW OF COLDER
AIR...WITH 12Z H85 TEMPS DOWN TO -17C AT INL...IN THE WAKE OF THIS
FROPA IS CAUSING SOME LES IN THE FAVORED SN BELTS. ALTHOUGH SOME MDT
SN SHOWERS IMPACTED THE FAVORED SN BELTS OVER THE W EARLIER THIS
AFTN WITH 3-6 INCHES OF SN FALLING JUST W OF BARAGA...DNVA/DEEP LYR
QVECTOR DVGC...SUBSIDENCE IN THE WAKE OF THIS DISTURBANCE AND THE
ADVECTION OF DRY NEAR SFC AIR UPSTREAM IN NRN MN IS LIMITING THE
INTENSITY OF THE SN SHOWERS THERE NOW. THE MORE NMRS MULTIPLE BAND
SN SHOWERS ARE NOW STREAMING INTO THE ERN CWA. EVEN WHERE THE SN
SHOWERS ARE NOT PARTICULARLY HEAVY...GUSTY WINDS THAT REACHED AS HI
AS 45-50 MPH/BLSN ARE RESULTING IN REDUCED VSBYS. LOOKING FARTHER TO
THE W...THERE IS A SFC HI PRES RDG OVER THE PLAINS...AND PWAT AS LO
AS 0.11 INCH AT ABERDEEN SDAKOTA /ABOUT 50 PCT OF NORMAL/. DESPITE
THIS DRYNESS...THERE ARE SOME HI CLDS MOVING THRU THE NRN PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LES AND WIND
TRENDS/TOTALS AS WELL AS MIN TEMPS TNGT.
LATE TODAY/TNGT...PERSISTENT DNVA/DEEP LYR QVECTOR DVGC/SUBSIDENCE
CONTRIBUTING TO 12HR H5 HGT RISES FCST IN EXCESS OF 150M BTWN 18Z
TODAY AND 06Z TNGT/LOWERING INVRN BASE TO H9-850 AS WELL AS THE
ADVECTION OF DRIER AIR WL TEND TO LIMIT LES INTENSITY. THERE COULD
BE A PERIOD OF MODERATE SN SHOWERS E OF MUNISING INTO THE EVNG
BEFORE THE DRIER LLVL AIR ARRIVES THERE. CONSIDERED AN LES ADVY FOR
THIS AREA WITH THE GUSTY WINDS/BLSN AND FAVORABLE FCST UVV WITHIN
THE DGZ BTWN ABOUT 2-5K FT...BUT NEGATIVE DYNAMICS/DRY ADVECTION
NOTED EARLIER AS WELL AS EXPECTED SHIFTING WINDS ASSOCIATED WITH
APRCHG SFC HI PRES FM THE PLAINS THAT WL LIMIT RESIDENCE TIME OF THE
BANDS INDICATES ADVY SN TOTALS WL NOT BE WIDESPREAD ENUF TO JUSTIFY
THE HEADLINE. ISSUED A SPECIAL WX STATEMENT FOR ALGER/LUCE COUNTIES
TO DISCUSS THE LES/BLSN/POTENTIAL FOR MINOR LK SHORE EROSION AND
FLOODING ACCOMPANYING THE LARGE WAVES FCST TO BUILD AS HI AS 13-15FT
THIS EVNG. CLOSER APRCH OF SFC HI PRES WITH BACKING/DIMINISHING
WINDS TOWARD THE SW LATE WL END ANY LINGERING LES OVER THE FAR W.
ALTHOUGH SOME HI CLDS MAY DRIFT E FM THE NRN PLAINS INTO THIS AREA
LATE...LIGHTER WINDS/DRY AIR WL ALLOW TEMPS TO FALL BLO ZERO NEAR
THE WI BORDER.
THU...AS THE UPR FLOW TENDS MORE ZONAL...SFC HI PRES IS FCST TO
SHIFT E TOWARD NEW ENGLAND. THE UPR LKS WL BE DOMINATED BY RETURN
SSW FLOW BTWN THIS DEPARTING SFC HI AND FALLING MSLP IN THE PLAINS.
SOME OF THE MODELS...MAINLY THE 12Z GLOBAL AND REGIONAL CNDN
MODELS...GENERATE SOME LGT PCPN UNDER LARGER SCALE ISENTROPIC
ASCENT. BUT SINCE STRONGER DEEP LYR QVECTOR CNVGC ASSOCIATED WITH
THIS WAA AND SOME DVPA IN ADVANCE OF A WEAK SHRTWV MOVING THRU
ONTARIO WL PASS TO THE N...THERE WL BE A CONTINUED FEED OF LLVL DRY
AIR AND THE LLVL FLOW WL REMAIN WEAKLY ACYC...WL TEND TOWARD THE
DRIER FCSTS. CONCERNED SOME LES COULD DVLP OFF LK MI DURING THE AFTN
WHEN A STRONGER SSW FLOW DVLPS THERE...BUT NAM FCST SDNGS SHOW LO
INVRN BASE NEAR H925 AND ENUF LLVL DRY AIR TO LIMIT THIS POTENTIAL.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 AM EST THU DEC 4 2014
NAM SHOWS A TROUGH OVER THE CENTRAL PLAINS WITH A RIDGE IN THE
WESTERN U.S. 12Z FRI AND A TROUGH OFF THE PACIFIC COAST. THERE IS
ALSO A SHORTWAVE ACROSS THE CANADIAN PRAIRIES. BOTH TROUGHS HEAD
EAST FRI NIGHT. TROUGHING THEN MOVES INTO THE NORTHERN ROCKIES 12Z
SUN.
LOOKS DRY FOR SAT AND SAT NIGHT AND QUIET FOR THIS FORECAST PERIOD.
WITH A WEAK DISTURBANCE MOVING THROUGH ON FRI...SLIGHT CHANCE POPS
WITH SOME LAKE ENHANCEMENT FROM LAKE MICHIGAN OVER THE EASTERN CWA
CANNOT COMPLETELY BE RULED OUT. DID NOT MAKE TOO MANY CHANGES TO THE
GOING FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE PLAINS
AND NORTHERN ROCKIES 12Z SUN WITH AN ALBERTA CLIPPER SYSTEM MOVING
SOUTHEAST TOWARDS THE AREA. THIS TROUGH HEADS INTO THE UPPER GREAT
LAKES 12Z MON. THIS TROUGH MOVES TO THE EAST WITH SFC HIGH PRESSURE
MOVING INTO THE AREA 12Z TUE. THE SFC HIGH MOVES TO THE EAST 12Z WED
BUT IS STILL CLOSE ENOUGH TO AFFECT THE WEATHER. TEMPERATURES LOOK
TO STAY NEAR NORMAL THIS FORECAST PERIOD. WILL BRING IN SOME CHANCE
POPS FOR SUNDAY NIGHT AND FOR MONDAY FOR MOST OF THE AREA WITH THE
ALBERTA CLIPPER MOVING IN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1208 AM EST THU DEC 4 2014
DRY AIR MOVING IN FROM MN WILL RESULT IN DIMINISHING LES AND
IMPROVING CONDITIONS AT CMX OVERNIGHT. AS THE WINDS ALSO TAPER
OFF...THE BLSN WILL ALSO DIMINISH RESULTING IN VFR VSBY. HOWEVER...
THE UPSLOPE FLOW...ESPECIALLY WITH A MORE FAVORABLE WRLY FETCH LATE
TONIGHT INTO EARLY THU WILL KEEP CIGS NEAR MVFR THRESHOLD DESPITE
THE INCOMING DRY AIR UNTIL WINDS BACKING TO SW BRING IMPROVEMENT THU
MORNING. OTHERWISE...VFR CONDITIONS ARE EXPECTED AT IWD AND SAW.
ALTHOUGH MID CLOUDS WILL INCREASE THU...LINGERING LOW LEVEL DRY AIR
WILL RESULT IN PREDOMINANT VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 256 PM EST WED DEC 3 2014
STRONG WINDS AND LIGHT TO MODERATE FREEZING SPRAY POSSIBLE. A
EXITING LOW NEAR JAMES BAY WILL KEEP A WEAKENING TROUGH
ACROSS LAKE SUPERIOR. W-NW GALES OF 35-40KTS ARE EXPECTED INTO THIS
EVENING. THE TROUGH WILL BE REPLACED BY HIGH PRESSURE SYSTEM
OVERNIGHT INTO THURSDAY MORNING /WITH WINDS DIMINISHING/...BEFORE IT
EXITS INTO S QUEBEC LATE THURSDAY. A LOW SLIDING ACROSS S CENTRAL
CANADA THURSDAY AND THURSDAY NIGHT WILL CROSS LAKE SUPERIOR ON
FRIDAY. BEHIND THIS LOW...A HIGH WILL BUILD IN FROM THE N PLAINS
SATURDAY. THE HIGH WILL THEN PUSH ACROSS THE LOWER GREAT LAKES
SATURDAY NIGHT. A LOW PRESSURE SYSTEM MAY ORGANIZE OVER SOUTH
CENTRAL CANADA AND POSSIBLY CROSS INTO THE UPPER GREAT LAKES ON
SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1208 AM EST THU DEC 4 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 338 PM EST WED DEC 3 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR TROF
CENTERED FM HUDSON BAY INTO THE GREAT LKS DOWNSTREAM OF A RDG OVER
WRN CANADA. SHRTWV EMBEDDED WITHIN THE NW FLOW ALF IS TRACKING THRU
ONTARIO AND DRAGGING A COLD FNT THRU THE UPR LKS. WNW FLOW OF COLDER
AIR...WITH 12Z H85 TEMPS DOWN TO -17C AT INL...IN THE WAKE OF THIS
FROPA IS CAUSING SOME LES IN THE FAVORED SN BELTS. ALTHOUGH SOME MDT
SN SHOWERS IMPACTED THE FAVORED SN BELTS OVER THE W EARLIER THIS
AFTN WITH 3-6 INCHES OF SN FALLING JUST W OF BARAGA...DNVA/DEEP LYR
QVECTOR DVGC...SUBSIDENCE IN THE WAKE OF THIS DISTURBANCE AND THE
ADVECTION OF DRY NEAR SFC AIR UPSTREAM IN NRN MN IS LIMITING THE
INTENSITY OF THE SN SHOWERS THERE NOW. THE MORE NMRS MULTIPLE BAND
SN SHOWERS ARE NOW STREAMING INTO THE ERN CWA. EVEN WHERE THE SN
SHOWERS ARE NOT PARTICULARLY HEAVY...GUSTY WINDS THAT REACHED AS HI
AS 45-50 MPH/BLSN ARE RESULTING IN REDUCED VSBYS. LOOKING FARTHER TO
THE W...THERE IS A SFC HI PRES RDG OVER THE PLAINS...AND PWAT AS LO
AS 0.11 INCH AT ABERDEEN SDAKOTA /ABOUT 50 PCT OF NORMAL/. DESPITE
THIS DRYNESS...THERE ARE SOME HI CLDS MOVING THRU THE NRN PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LES AND WIND
TRENDS/TOTALS AS WELL AS MIN TEMPS TNGT.
LATE TODAY/TNGT...PERSISTENT DNVA/DEEP LYR QVECTOR DVGC/SUBSIDENCE
CONTRIBUTING TO 12HR H5 HGT RISES FCST IN EXCESS OF 150M BTWN 18Z
TODAY AND 06Z TNGT/LOWERING INVRN BASE TO H9-850 AS WELL AS THE
ADVECTION OF DRIER AIR WL TEND TO LIMIT LES INTENSITY. THERE COULD
BE A PERIOD OF MODERATE SN SHOWERS E OF MUNISING INTO THE EVNG
BEFORE THE DRIER LLVL AIR ARRIVES THERE. CONSIDERED AN LES ADVY FOR
THIS AREA WITH THE GUSTY WINDS/BLSN AND FAVORABLE FCST UVV WITHIN
THE DGZ BTWN ABOUT 2-5K FT...BUT NEGATIVE DYNAMICS/DRY ADVECTION
NOTED EARLIER AS WELL AS EXPECTED SHIFTING WINDS ASSOCIATED WITH
APRCHG SFC HI PRES FM THE PLAINS THAT WL LIMIT RESIDENCE TIME OF THE
BANDS INDICATES ADVY SN TOTALS WL NOT BE WIDESPREAD ENUF TO JUSTIFY
THE HEADLINE. ISSUED A SPECIAL WX STATEMENT FOR ALGER/LUCE COUNTIES
TO DISCUSS THE LES/BLSN/POTENTIAL FOR MINOR LK SHORE EROSION AND
FLOODING ACCOMPANYING THE LARGE WAVES FCST TO BUILD AS HI AS 13-15FT
THIS EVNG. CLOSER APRCH OF SFC HI PRES WITH BACKING/DIMINISHING
WINDS TOWARD THE SW LATE WL END ANY LINGERING LES OVER THE FAR W.
ALTHOUGH SOME HI CLDS MAY DRIFT E FM THE NRN PLAINS INTO THIS AREA
LATE...LIGHTER WINDS/DRY AIR WL ALLOW TEMPS TO FALL BLO ZERO NEAR
THE WI BORDER.
THU...AS THE UPR FLOW TENDS MORE ZONAL...SFC HI PRES IS FCST TO
SHIFT E TOWARD NEW ENGLAND. THE UPR LKS WL BE DOMINATED BY RETURN
SSW FLOW BTWN THIS DEPARTING SFC HI AND FALLING MSLP IN THE PLAINS.
SOME OF THE MODELS...MAINLY THE 12Z GLOBAL AND REGIONAL CNDN
MODELS...GENERATE SOME LGT PCPN UNDER LARGER SCALE ISENTROPIC
ASCENT. BUT SINCE STRONGER DEEP LYR QVECTOR CNVGC ASSOCIATED WITH
THIS WAA AND SOME DVPA IN ADVANCE OF A WEAK SHRTWV MOVING THRU
ONTARIO WL PASS TO THE N...THERE WL BE A CONTINUED FEED OF LLVL DRY
AIR AND THE LLVL FLOW WL REMAIN WEAKLY ACYC...WL TEND TOWARD THE
DRIER FCSTS. CONCERNED SOME LES COULD DVLP OFF LK MI DURING THE AFTN
WHEN A STRONGER SSW FLOW DVLPS THERE...BUT NAM FCST SDNGS SHOW LO
INVRN BASE NEAR H925 AND ENUF LLVL DRY AIR TO LIMIT THIS POTENTIAL.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 256 PM EST WED DEC 3 2014
MAY SEE SOME SNOW OVER NRN/ERN UPPER MI FRI AS A SHORTWAVE MOVES
NEAR OR N OF THE CWA. 00Z/02 ECMWF SHOWS THE MOST SNOW /STILL ONLY
0.10 INCHES OF QPF OR LESS/ AS IT HAS THE SHORTWAVE FARTHEST
S...WHILE OTHER MODELS BARELY HAVE ANY QPF. WILL KEEP SLIGHT CHANCE
POPS OVER THE NERN CWA...LINGERING INTO FRI NIGHT OVER THE E AS
COLDER AIR AND NW LOW LEVEL WINDS RESULT BEHIND THE SHORTWAVE...BUT
STILL NOT SUFFICIENT FOR MORE THAN ISOLATED LES.
1038MB SFC HIGH MOVES ACROSS THE CWA ON SAT...WITH INCREASING LOW
LEVEL WARMTH /850MB TEMPS INCREASING TO AROUND 2C/ IN SW FLOW BEHIND
THE HIGH ON SUN. CONFIDENCE DECREASES SUN THROUGH NEXT WED AS MODELS
DISAGREE SIGNIFICANTLY WITH A SHORTWAVE AND UPPER TROUGH MOVING
ACROSS THE REGION. WHILE TIMING IS NOT AGREED ON...850MB TEMPS
DROPPING INTO THE TEENS BELOW ZERO WILL LEAD TO LES BEHIND THE
SHORTWAVE/TROUGH SOMETIME MON INTO TUE. MODELS CONTINUE TO DISAGREE
SIGNIFICANTLY WITH THE PATTERN BEHIND THE TROUGH. WILL USE CONSENSUS
OF GUIDANCE BLENDED WITH PREVIOUS FORECAST FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1208 AM EST THU DEC 4 2014
DRY AIR MOVING IN FROM MN WILL RESULT IN DIMINISHING LES AND
IMPROVING CONDITIONS AT CMX OVERNIGHT. AS THE WINDS ALSO TAPER
OFF...THE BLSN WILL ALSO DIMINISH RESULTING IN VFR VSBY. HOWEVER...
THE UPSLOPE FLOW...ESPECIALLY WITH A MORE FAVORABLE WRLY FETCH LATE
TONIGHT INTO EARLY THU WILL KEEP CIGS NEAR MVFR THRESHOLD DESPITE
THE INCOMING DRY AIR UNTIL WINDS BACKING TO SW BRING IMPROVEMENT THU
MORNING. OTHERWISE...VFR CONDITIONS ARE EXPECTED AT IWD AND SAW.
ALTHOUGH MID CLOUDS WILL INCREASE THU...LINGERING LOW LEVEL DRY AIR
WILL RESULT IN PREDOMINANT VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 256 PM EST WED DEC 3 2014
STRONG WINDS AND LIGHT TO MODERATE FREEZING SPRAY POSSIBLE. A
EXITING LOW NEAR JAMES BAY WILL KEEP A WEAKENING TROUGH
ACROSS LAKE SUPERIOR. W-NW GALES OF 35-40KTS ARE EXPECTED INTO THIS
EVENING. THE TROUGH WILL BE REPLACED BY HIGH PRESSURE SYSTEM
OVERNIGHT INTO THURSDAY MORNING /WITH WINDS DIMINISHING/...BEFORE IT
EXITS INTO S QUEBEC LATE THURSDAY. A LOW SLIDING ACROSS S CENTRAL
CANADA THURSDAY AND THURSDAY NIGHT WILL CROSS LAKE SUPERIOR ON
FRIDAY. BEHIND THIS LOW...A HIGH WILL BUILD IN FROM THE N PLAINS
SATURDAY. THE HIGH WILL THEN PUSH ACROSS THE LOWER GREAT LAKES
SATURDAY NIGHT. A LOW PRESSURE SYSTEM MAY ORGANIZE OVER SOUTH
CENTRAL CANADA AND POSSIBLY CROSS INTO THE UPPER GREAT LAKES ON
SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
336 PM CST THU DEC 4 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 251 PM CST THU DEC 4 2014
SOUTHERLY WINDS CONTINUE THIS AFTERNOON AS HIGH PRESSURE PUSHES OFF
TO THE EAST. THE CONCERN IN THE SHORT TERM PERIOD TURNS TO THE UPPER
TROUGH AND ASSOCIATED SURFACE LOW MOVING EAST TO WEST ACROSS THE
CENTRAL CONUS. ALL APPRECIABLE PRECIPITATION FROM THIS SYSTEM WILL
STAY WELL SOUTH OF THE FA AS THE TRUE FORCING WILL SHIFT FROM NEAR
OKLAHOMA THROUGH THE OHIO RIVER VALLEY REGION THROUGH FRIDAY
EVENING. THIS SYSTEM WILL IMPACT OUR REGION TONIGHT THROUGH FRIDAY
WITH WIDESPREAD LOW STRATUS COVER. THE QUESTION BECOMES WHETHER OR
NOT ANY LIGHT PRECIP COULD BE RUNG OUT OF THIS LOW LEVEL MOISTURE.
AN EVALUATION OF RAP AND NAM SOUNDINGS INDICATE THAT LOW LEVEL
SATURATION BELOW 900H WITH A LITTLE LIFT PRESENT...WARRANTS THE
MENTION OF FREEZING DRIZZLE WITH THE POSSIBILITY OF A FEW
SNOWFLAKES. IN TERMS OF THE WESTERN EXTENT OF THE LOW
CLOUDS...CONFIDENCE IS LOW...BUT STICKING WITH A BLEND OF THE NAM
AND RAP GUIDANCE FOR NOW. WITH LITTLE MIXING TOMORROW...AND VERY
MOIST LOW LEVEL PROFILES INDICATE LOW CLOUDS COULD LINGER FOR MOST
OF THE DAY IN EASTERN AREAS. IN TERMS OF TEMPERATURES...SOUTHERLY
WINDS AND A WARMER AIR MASS WILL MAKE FOR SLIGHTLY ABOVE NORMAL
TEMPERATURES...WITH HIGHS EXPECTED IN THE 30S ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 251 PM CST THU DEC 4 2014
LONG TERM CONCERNS REMAIN THE MIXED PRECIPITATION THREAT
DEVELOPING SUNDAY AND THEN THE WARMING TREND THROUGH NEXT WEEK.
COOLER HIGH PRESSURE DROPS INTO THE AREA FRIDAY NIGHT AND
SATURDAY. RETURN FLOW DEVELOPS AHEAD OF THE TROUGH THAT REMAINS
OFF SHORE OF THE PACIFIC NORTHWEST. THIS TROUGH MOVES ASHORE FRIDAY
NIGHT AND INTO THE DAKOTAS AND MINNESOTA ON SUNDAY. BUFKIT
PROFILES INDICATE A NICE WARM LAYER ALOFT AS THE WARMER AIR LIFTS
NORTH INTO THE AREA. THE TROUGH DEEPENS AND MOVES INTO THE AREA
SUNDAY AND SUNDAY NIGHT. WE SHOULD SEE A WINTRY MIX OF FREEZING
RAIN/SLEET AND SNOW CHANGING OVER TO SNOW FROM WEST TO EAST
THROUGH SUNDAY. WILL INCLUDE THIS THREAT IN THE GRIDS AT THIS
TIME. STILL A QUESTION HOW FAR EAST THIS WILL OCCUR AS THE VARIOUS
DETERMINISTIC RUNS ARE STILL IN DISAGREEMENT ON HOW DEEP THE TROUGH
DEVELOPS THROUGH SUNDAY. IT APPEARS THE NAM_WRF HAS TRENDED DEEPER
WITH THE TROUGH...MORE DYNAMIC...WHICH MAY PRECLUDE SIGNIFICANT
PERIOD OF MIXED PRECIPITATION. CONTINUED THE HIGH CHANCE POP TREND
FOR NOW. THE THALER QG FROM THE NAM AND THE GFS SHOWS DECENT
FORCING BEING GENERATED AHEAD OF THE TROUGH. IF THIS CONTINUES...WILL
INCREASE POPS IN LATER FORECASTS. THE GFS IS THE WEAKEST...AND
CONTINUES TO MOVE THE SURFACE LOW WELL NORTH OF THE AREA.
COOLER AIR FOLLOWS THIS SYSTEM FOR MONDAY NIGHT AND TUESDAY. THEN
SOME DISCREPANCY IN THE MODELS WITH THE POSSIBILITY OF ANOTHER
TROUGH DROPPING SOUTH AND EAST OVER THE AREA FOR
WEDNESDAY/THURSDAY TIME FRAME. THE ECMWF IS MORE BULLISH ON
DEVELOPING A SYSTEM OVER THE AREA DURING THIS TIME PERIOD. WE
CURRENTLY HAVE A DRY FORECAST FOR THE MID PART OF THE WEEK. BOTH
MODELS SUGGEST THE UPPER RIDGE FINALLY PROPAGATES EAST INTO THE
AREA BY NEXT WEEKEND. THIS SHOULD YIELD MUCH WARMER AIR WITH A
GOOD SNOW MELT ANTICIPATED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1158 AM CST THU DEC 4 2014
VFR TO START THE PERIOD WITH MOSTLY CLEAR SKIES AND SOUTHERLY
WINDS FOR THE REMAINDER OF THE AFTERNOON. STRATUS IS ADVANCING
NORTH INTO SOUTHERN IOWA AT THIS TIME AHEAD OF A WEAK DEVELOPING
SURFACE LOW. LOW LEVEL MOISTURE WILL CONTINUE TO STREAM NORTH IN
THIS WAA REGIME WITH STRATUS EXPECTED TO SPREAD INTO SOUTHERN MN
NEAR SUNDOWN AND BEYOND. RAP GUIDANCE SUGGESTS A FINE LINE BETWEEN
VFR AND MVFR/IFR CIGS COULD CUT RIGHT THROUGH MINNESOTA...WITH A
SHARP EDGE TO THE STRATUS DECK. AT THIS POINT...EXPECTING
RESTRICTIONS FROM ST CLOUD EASTWARD...WITH THE LOWEST CONFIDENCE
IN THAT ALONG THE WESTERN AREAS DUE TO PLACEMENT OF THE WESTERN
EDGE OF STRATUS. THE HRRR ACTUALLY INDICATES THE CLOUD LINE TO BE
JUST WEST OF MSP MUCH OF THE NIGHT. NAM SOUNDINGS ARE QUITE
PESSIMISTIC AND HAVE BEEN CONSISTENT IN THAT. INTRODUCE IFR CIGS
WITH BR LIKELY UNDER THE STRATUS OVERNIGHT. THE DETAILS WILL NEED
TO BE IRONED OUT IN COMING ISSUANCE`S. STILL HAVE SOME CONCERN FOR
-FZDZ IN WESTERN WI...HOWEVER JUST STUCK WITH BR FOR NOW IN THE
TAFS. CLOUDS SHOULD LINGER IN EASTERN AREAS THROUGH
FRIDAY...LIKELY RAISING TO MVFR LEVELS FOR MOST OF THE DAY.
KMSP...HRRR AND RAP 0.5KM CONDENSATION PRESSURE DEFICITS INDICATE
MSP COULD BE VERY CLOSE TO THE LOW LEVEL CLOUD LINE TONIGHT. THE
NAM BLOWS THE LOW LEVEL SATURATION ACROSS A WIDER AREA...HOWEVER.
SREF PROBS INDICATE CEILINGS SHOULD EXPAND WEST. BUT STILL EXPECT
CEILINGS TO IMPACT MSP AT THIS TIME...BUT WITH LOW CONFIDENCE DUE
TO THE PROXIMITY TO THE UNSATURATED AIR.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS E/NE AT 5-10 KTS.
SUN...VFR WITH MVFR/-SN POSSIBLE. WINDS S AT 10G20KTS.
MON...VFR. POSSIBLE MVFR CIGS EARLY. WINDS WNW/NW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...DWE
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1224 PM CST THU DEC 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CST THU DEC 4 2014
MAIN CONCERN OVER THE NEXT 24 TO 30 HRS IS THE CHC OF --FZDZ/--SN
AND FOG POTENTIAL AS MOISTURE BEGINS TO SURGE NORTHWARD AHEAD OF A
STORM SYSTEM MOVING ACROSS THE SOUTHERN CONUS.
THE ORIGIN OF THIS MOISTURE WAS ACROSS OK/KS/MO WHICH EARLY THIS
MORNING HAD LOW CIGS/FOG/-RA AND DRIZZLE. SHORT TERM MODELS HAVE
THIS AREA SURGING NORTHWARD THIS AFTN ACROSS IA...AND INTO FAR
SOUTHERN MN BY LATE IN THE AFTN. ALTHOUGH I AM NOT CONVINCED OUR
REGION WILL HAVE AREAS OF FOG THIS EVENING...PATCHY FOG AND
SOME LIGHT PRECIPITATION IS POSSIBLE...ESPECIALLY TOWARD MIDNIGHT IN
SC/EC MN AND WC WI. THIS IS WHERE WINDS IN THE LOWEST 3K REMAIN FROM
THE S/SSW AND ADVECT THIS AREA OF MOISTURE NORTHWARD THRU THE
DAY/OVERNIGHT. AS TEMPS HOLD NEAR OR BLW FREEZING...THE POTENTIAL OF
FREEZING DRIZZLE EXISTS. THE BEST POTENTIAL OF FREEZING DRIZZLE WILL
OCCUR IN WC WI WHERE BOTH THE DEPTH OF THE MOISTURE WILL BE HIGHER
AND PERSIST THRU THE NIGHT. IN ADDITION...THE MOISTURE LAYER HAS
TEMPS REMAINING BETWEEN -2C TO -8C. THEREFORE...VERY LITTLE CHC OF
ICE CRYSTALS...SO THE MAIN FORM SHOULD BE FREEZING DRIZZLE. ANY
FREEZING PRECIPITATION THAT DOES FALL SHOULD BE VERY LIGHT AND MAJOR
TRAVEL PROBLEMS ARE NOT EXPECTED.
WITH THE SOUTHERLY FLOW TODAY AND TONIGHT...TEMPS WILL RISE STEADY
THRU THE DAY...AND LIKELY HOLD STEADY OR ONLY FALL A DEGREE OR TWO
TONIGHT. WHERE THE SNOW COVER IS NON-EXISTENT IN SW MN...TEMPS WILL
LIKELY RISE TO NEAR 40 DEGREES. 20S AND LOWER 30S SEEM REASONABLE
ELSEWHERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 330 AM CST THU DEC 4 2014
THE MAIN CONCERN IN THE LONGER TERM CENTERS AROUND PRECIPITATION
CHANCES FROM SUNDAY INTO MONDAY. OVER THE PAST 24 HOURS (2 RUNS)
THE ECMWF HAS BACKED AWAY FROM A CLOSED MID LEVEL LOW DROPPING
SOUTH ACROSS OUR AREA LATE SUNDAY INTO MONDAY. IT/S NOW
FORECASTING A DEEP OPEN WAVE PROGRESSING EASTWARD ACROSS THE UPPER
MISSISSIPPI VALLEY. THIS IS SIMILAR TO WHAT THE GFS HAS HAD FOR
SEVERAL DAYS. THE GEM REMAINS THE OUTLIER WITH A CLOSED LOW
DRIVING SOUTHEAST ACROSS THE DAKOTAS AND INTO IA BY MONDAY
MORNING. OUR INTERNAL HOPWRF IS SIMILAR TO THE GFS BUT WEAKER AND
FARTHER NORTH WITH A CLOSED UPPER LOW. THE DIFFERENT SOLUTIONS
PROVIDE QUITE A VARIETY OF PRECIPITATION AMOUNTS. ON THE LOW END
IS THE 4KM HOPWRF WITH ESSENTIALLY NO PRECIPITATION FORECAST
SUNDAY-MONDAY. NEXT IS THE ECMWF WITH PERHAPS AN INCH OF SNOW
ACROSS EASTERN MN AND WESTERN WI. THE GFS WOULD BE MORE IN THE 1
TO 2 INCH RANGE FOR THE SAME AREAS WHILE THE GEM WOULD BE IN THE 3
TO 4 INCH RANGE. FOLLOWED MORE OF A ECMWF/GFS BLEND WITH HIGH
CHANCE POPS SPREADING EAST ON SUNDAY AND CONTINUING ACROSS EASTERN
AREAS SUNDAY NIGHT AND MONDAY. ONE THING WHERE CONFIDENCE IS HIGH
IS ON THE WIND SPEED FOR SUNDAY. STRONG SOUTHERLY WINDS WILL
DEVELOP DURING THE DAY ACROSS WEST CENTRAL THROUGH SOUTH CENTRAL MN.
SPEEDS FROM 20 TO 30 KNOTS SUSTAINED ARE LIKELY. THE 4KM HOPWRF
SHOWS AREAS OF WESTERN LAC QUI PARLE COUNTY WITH NEAR 30 KNOT
SUSTAINED WINDS LATE SUNDAY AFTERNOON/EVENING. HENCE...WINDS WERE
RAISED CONSIDERABLY OVER GUIDANCE FOR WEST CENTRAL THROUGH SOUTH
CENTRAL MN.
ANOTHER CONCERN NEXT WEEK IS A CHANCE FOR PRECIPITATION LATE
TUESDAY AND TUESDAY NIGHT. THE ECMWF HAS BEEN DRY DURING THIS
PERIOD WHILE THE GFS HAS A SHORT WAVE AND SOME PRECIPITATION
MOVING THOUGH. DP/DT ON THE GFS FOR TUESDAY EVENING SHOWS THAT
THIS WAVE IS NOT BEING HANDLED WELL (NOT CONSISTENT). OVER THE
PAST TWO RUNS THERE HAS BEEN A WEAKENING TREND WITH WHAT LOOKS
LIKE A SPLIT DEVELOPING IN THE WAVE WITH PIECES PASSING NORTH AND
SOUTH OF US. AT THIS POINT...WE LOWERED THE SLIGHT CHANCE POPS
FROM THE BLENDED GUIDANCE AND MAINTAINED A DRY FORECAST.
TEMPERATURES WILL BE NEAR SEASONAL LEVELS THROUGH MUCH OF THE
PERIOD. EXCEPTIONS ARE SATURDAY AND TUESDAY WHERE HIGHS WILL ONLY
BE IN THE LOWER TO MIDDLE 20S. HIGHS WERE BUMPED UP A BIT OVER
GUIDANCE ON SUNDAY WITH LOWER TO MIDDLE 30S FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1158 AM CST THU DEC 4 2014
VFR TO START THE PERIOD WITH MOSTLY CLEAR SKIES AND SOUTHERLY
WINDS FOR THE REMAINDER OF THE AFTERNOON. STRATUS IS ADVANCING
NORTH INTO SOUTHERN IOWA AT THIS TIME AHEAD OF A WEAK DEVELOPING
SURFACE LOW. LOW LEVEL MOISTURE WILL CONTINUE TO STREAM NORTH IN
THIS WAA REGIME WITH STRATUS EXPECTED TO SPREAD INTO SOUTHERN MN
NEAR SUNDOWN AND BEYOND. RAP GUIDANCE SUGGESTS A FINE LINE BETWEEN
VFR AND MVFR/IFR CIGS COULD CUT RIGHT THROUGH MINNESOTA...WITH A
SHARP EDGE TO THE STRATUS DECK. AT THIS POINT...EXPECTING
RESTRICTIONS FROM ST CLOUD EASTWARD...WITH THE LOWEST CONFIDENCE
IN THAT ALONG THE WESTERN AREAS DUE TO PLACEMENT OF THE WESTERN
EDGE OF STRATUS. THE HRRR ACTUALLY INDICATES THE CLOUD LINE TO BE
JUST WEST OF MSP MUCH OF THE NIGHT. NAM SOUNDINGS ARE QUITE
PESSIMISTIC AND HAVE BEEN CONSISTENT IN THAT. INTRODUCE IFR CIGS
WITH BR LIKELY UNDER THE STRATUS OVERNIGHT. THE DETAILS WILL NEED
TO BE IRONED OUT IN COMING ISSUANCE`S. STILL HAVE SOME CONCERN FOR
-FZDZ IN WESTERN WI...HOWEVER JUST STUCK WITH BR FOR NOW IN THE
TAFS. CLOUDS SHOULD LINGER IN EASTERN AREAS THROUGH
FRIDAY...LIKELY RAISING TO MVFR LEVELS FOR MOST OF THE DAY.
KMSP...HRRR AND RAP 0.5KM CONDENSATION PRESSURE DEFICITS INDICATE
MSP COULD BE VERY CLOSE TO THE LOW LEVEL CLOUD LINE TONIGHT. THE
NAM BLOWS THE LOW LEVEL SATURATION ACROSS A WIDER AREA...HOWEVER.
SREF PROBS INDICATE CEILINGS SHOULD EXPAND WEST. BUT STILL EXPECT
CEILINGS TO IMPACT MSP AT THIS TIME...BUT WITH LOW CONFIDENCE DUE
TO THE PROXIMITY TO THE UNSATURATED AIR.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS E/NE AT 5-10 KTS.
SUN...VFR WITH MVFR/-SN POSSIBLE. WINDS S AT 10G20KTS.
MON...VFR. POSSIBLE MVFR CIGS EARLY. WINDS WNW/NW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...RAH
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
326 AM CST Thu Dec 4 2014
.DISCUSSION...
Issued at 325 AM CST THU DEC 4 2014
Dry air across the region is making it difficult for low-level
moisture to make it this far north, and drizzle chances are quickly
decreasing as a result. At 3 AM low clouds and light drizzle have
only made it as far north as Joplin and Chanute and probably won`t
make it into east central KS and west central MO until 6 AM at the
earliest with a better push further east toward Clinton and Boonville
after 6 AM. At this point it`s looking unlikely that precipitation will
be able to make it much further north or west than a Butler-
Marshall- Moberly line, and drizzle has been taken out of the
forecast for Kansas City and surrounding areas. Even for areas that
do see drizzle, temperatures have remained above freezing and look to
generally stay that way through the morning. Can`t rule out that
wetbulb effects could briefly bring some areas below freezing
wherever precipitation does materialize but it may not be heavy
enough to do this for very long. One exception may be the Moberly
area where temperatures have been hovering around 32 overnight.
Bottom line is that the potential for hazardous icing is quickly
decreasing and travel problems should be few and far between this
morning.
A much stronger batch of precipitation will organize late tonight
into Friday morning as a weak wave approaches the area and synoptic-
scale ascent becomes much better organized. While the main upper wave
isn`t particularly strong, the combination of strong upper divergence
between two upper jet maxima and deep low-level isentropic ascent
will be supportive of widespread rainfall amounts of a half inch or
more. In fact, a band of persistent frontogenesis and unseasonably
high precipitable water amounts over an inch could lead to a band of
1"+ rainfall amounts near or just south of the I-70 corridor. It
still looks like all areas will stay above freezing through this
event so that all precipitation will fall as rain.
The forecast beyond Friday still looks uneventful with no systems of
note other than a weak front on Monday. While this system could
produce a couple of light rain or snow showers, dry air looks to
prevent much if any measurable precipitation. Temperatures will
remain close to seasonal averages through the period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1123 PM CST WED DEC 3 2014
325 AM UPDATE...Chances for freezing drizzle at the KC area terminals
are decreasing this morning. Any precipitation chances look to be
well to the east and southeast of the area, while temperatures
should stay near or above freezing. Have therefore removed any
mention of freezing precipitation from the TAFs.
MVFR ceilings will fill in across the area overnight as low level
moisture moves into the region. Mid-level deck of 6-7kft has already
begun to develop along and south of an KOJC to KDMO line. Conditions
continue to look favorable for freezing drizzle to develop between
10-12Z at KIXD, KMKC, and KMCI. KSTJ is still looking to be on the
very edge of precipitation so have left it out of the current TAF
period. Latest HRRR model run and bufkit soundings show ceilings
dropping down to IFR once drizzle begins. Once temperatures climb
above freezing tomorrow morning, just drizzle can be expected through
early afternoon. By afternoon, drizzle will wane but ceilings are
still expected to remain IFR to MVFR through the remainder of the
period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Hawblitzel
AVIATION...PMM
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1248 AM CST Thu Dec 4 2014
.UPDATE...
Issued at 1247 AM CST THU DEC 4 2014
Reports of drizzle have spread north from Tulsa into extreme
southeast KS this morning, and several short-range models still bring
drizzle into much of the forecast area by 12Z. This activity will be
encountering dry surface air this far north though where dewpoints
are still around 20 degrees. This will probably keep much drizzle
from materializing as quick as models indicate, but could still see
some light patches developing near and south of the Missouri River by
6 AM or so. One big question is if temperatures can drop below
freezing, as easterly flow and thickening clouds have kept them
steady in the mid 30s for the past several hours. Much of the short
range guidance keeps temperatures above freezing for most areas near
and south of the Missouri River. However, given the dewpoints, it
wouldn`t be surprising to see wetbulb effects produce some sub-
freezing temperatures where drizzle develops, so will keep the
freezing drizzle mention going for areas near the US 50 and I-70
corridors for the early morning hours. Butler and Clinton areas may
be out of the woods if these temperature trends continue.
&&
.DISCUSSION...
Issued at 300 PM CST WED DEC 3 2014
Conditions continue to look favorable for a window of freezing
drizzle tomorrow morning, right around the morning commute. Latest
satellite and surface observations show thicker lower-level moisture
poised across Oklahoma and Arkansas. Models continue to show this
moisture advecting northward later tonight in response to a weak
wave moving across the Central Plains. This will help produce broad
but weak isentropic ascent within this low-level moisture, providing
enough lift to get drizzle/freezing drizzle into the area late
tonight/early tomorrow morning. Temperatures have warmed into the
middle 40s for much of the area this afternoon and latest guidance
suggest that temperatures may not be as cool tonight as a result.
However... temperatures are still expected to fall below freezing
across much of the area before this moisture works northward and as a
result it looks like there will be several hour window, around the
morning commute, when freezing drizzle will be possible. Given this
setup, a light glazing is possible on area roads late tonight/early
tomorrow morning, which could lead to a treacherous morning commute
for some folks. As temperatures warm through the morning hours,
likely within an hour or two of sunrise for the Kansas City area, a
transition to just drizzle will occur, ending any potential for a
light glazing across the area.
This freezing drizzle/drizzle event should wind down by the
afternoon hours with focus then shifting to the Thursday night and
Friday time frame. The next short wave trough is expected to move
across the area late Thursday and Friday. With moisture in place,
better forcing aloft should lead to more widespread rainfall across
the area. The heaviest rain amounts look to be along and south of
I-70, where amounts may be upwards of an inch. With temperatures
expected to be above freezing throughout the forecast area, this
should be rainfall for the entire area. The only areas where this
could be in question would be across far northern Missouri. But for
now, temperatures look to remain above freezing there as well, so
the possibility of freezing rain looks unlikely at this point in
time.
The forecast for the extended looks relatively quiet with
temperatures close to normal. The one exception to this may be a
system that clips the area Sunday into Monday. Models show a clipper
system moving across the Upper Midwest with some trailing vorticity
moving across northern Missouri Sunday night/early Monday. This may
provide enough forcing to get some rain Sunday or a mix during the
overnight hours. After this system moves through, a ridge is
expected to build eastward and strengthen. This should result in a
warming trend with quiet weather for the later half of next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1123 PM CST WED DEC 3 2014
MVFR ceilings will fill in across the area overnight as low level
moisture moves into the region. Mid-level deck of 6-7kft has already
begun to develop along and south of an KOJC to KDMO line. Conditions
continue to look favorable for freezing drizzle to develop between
10-12Z at KIXD, KMKC, and KMCI. KSTJ is still looking to be on the
very edge of precipitation so have left it out of the current TAF
period. Latest HRRR model run and bufkit soundings show ceilings
dropping down to IFR once drizzle begins. Once temperatures climb
above freezing tomorrow morning, just drizzle can be expected through
early afternoon. By afternoon, drizzle will wane but ceilings are
still expected to remain IFR to MVFR through the remainder of the
period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...Hawblitzel
DISCUSSION...CDB
AVIATION...PMM
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1140 PM CST Wed Dec 3 2014
.DISCUSSION...
Issued at 300 PM CST WED DEC 3 2014
Conditions continue to look favorable for a window of freezing
drizzle tomorrow morning, right around the morning commute. Latest
satellite and surface observations show thicker lower-level moisture
poised across Oklahoma and Arkansas. Models continue to show this
moisture advecting northward later tonight in response to a weak
wave moving across the Central Plains. This will help produce broad
but weak isentropic ascent within this low-level moisture, providing
enough lift to get drizzle/freezing drizzle into the area late
tonight/early tomorrow morning. Temperatures have warmed into the
middle 40s for much of the area this afternoon and latest guidance
suggest that temperatures may not be as cool tonight as a result.
However... temperatures are still expected to fall below freezing
across much of the area before this moisture works northward and as a
result it looks like there will be several hour window, around the
morning commute, when freezing drizzle will be possible. Given this
setup, a light glazing is possible on area roads late tonight/early
tomorrow morning, which could lead to a treacherous morning commute
for some folks. As temperatures warm through the morning hours,
likely within an hour or two of sunrise for the Kansas City area, a
transition to just drizzle will occur, ending any potential for a
light glazing across the area.
This freezing drizzle/drizzle event should wind down by the
afternoon hours with focus then shifting to the Thursday night and
Friday time frame. The next short wave trough is expected to move
across the area late Thursday and Friday. With moisture in place,
better forcing aloft should lead to more widespread rainfall across
the area. The heaviest rain amounts look to be along and south of
I-70, where amounts may be upwards of an inch. With temperatures
expected to be above freezing throughout the forecast area, this
should be rainfall for the entire area. The only areas where this
could be in question would be across far northern Missouri. But for
now, temperatures look to remain above freezing there as well, so
the possibility of freezing rain looks unlikely at this point in
time.
The forecast for the extended looks relatively quiet with
temperatures close to normal. The one exception to this may be a
system that clips the area Sunday into Monday. Models show a clipper
system moving across the Upper Midwest with some trailing vorticity
moving across northern Missouri Sunday night/early Monday. This may
provide enough forcing to get some rain Sunday or a mix during the
overnight hours. After this system moves through, a ridge is
expected to build eastward and strengthen. This should result in a
warming trend with quiet weather for the later half of next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1123 PM CST WED DEC 3 2014
MVFR ceilings will fill in across the area overnight as low level
moisture moves into the region. Mid-level deck of 6-7kft has already
begun to develop along and south of an KOJC to KDMO line. Conditions
continue to look favorable for freezing drizzle to develop between
10-12Z at KIXD, KMKC, and KMCI. KSTJ is still looking to be on the
very edge of precipitation so have left it out of the current TAF
period. Latest HRRR model run and bufkit soundings show ceilings
dropping down to IFR once drizzle begins. Once temperatures climb
above freezing tomorrow morning, just drizzle can be expected through
early afternoon. By afternoon, drizzle will wane but ceilings are
still expected to remain IFR to MVFR through the remainder of the
period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...CDB
AVIATION...PMM
AREA FORECAST DISCUSSION
NWS BILLINGS MT
305 PM MST THU DEC 4 2014
.SHORT TERM...VALID FOR FRI AND SAT...
UPPER LEVEL RIDGE AMPLIFICATION OVER THE PACIFIC NORTHWEST DURING
THE NEXT 24 HOURS IS FOLLOWED BY THIS RIDGE WEAKENING BUT ITS AXIS
SHIFTING EASTWARD. BUILDING HEIGHTS OVER THE AREA SHOULD STABILIZE
THE AIRMASS BUT MOISTURE IS STILL FLOWING OVER THE RIDGE INTO THE
AREA. CURRENTLY RADAR SHOWS LIGHT RETURNS ACROSS THE AREA BUT
LATEST RUC MODEL ONLY MAINTAINS A COUPLE OF SIGNATURES OVERNIGHT
SO MOST OF THE AREA WILL BE DRY.
ONE OF THE TWO AREAS OF PRECIPITATION WILL BE THE MOUNTAINS WHICH
WILL CONTINUE TO SEE OROGRAPHIC SNOW BUT DYNAMIC FORCING IS WEAK.
THE OTHER AREA IS OVER NORTHERN PORTIONS OF SOUTHEAST MONTANA
WHERE A FRONTAL BOUNDARY SAGS SOUTH INTO THE AREA IN RESPONSE TO
THE DEVELOPMENT OF THE UPSTREAM RIDGE. THINK THAT MOST OF THIS
PRECIPITATION WILL BE A RAIN SNOW MIX GIVEN THE MIXING THAT
OCCURRED TODAY AS OPPOSED TO ANY FREEZING RAIN.
TOMORROW THIS FRONTAL BOUNDARY REMAINS OVER SOUTHEAST MONTANA AND
THE SURFACE TROUGH SHIFTS TO THE FOOTHILLS WHICH WILL CAUSE A LOW
LEVEL EASTERLY FLOW AND COOLER TEMPERATURES. AIRMASS DOES DRY OUT
SO DO NOT EXPECT ANY PRECIPITATION.
AS THE RIDGE AXIS MOVES THROUGH THE AREA FRIDAY NIGHT IT BRINGS A
DOWNSLOPE IT ALLOWS A SOUTHWEST FLOW ALOFT TO SET IN AND A LEESIDE
TROUGH DOWNSLOPE PATTERN TO EVOLVE. THIS WILL BRING WARMER
TEMPERATURES AND CONTINUED DRY CONDITIONS. BY SATURDAY NIGHT SOME
COOLING OVER IDAHO ALLOWS A GAP FLOW PATTERN TO EVOLVE BUT
STABILITY DOES NOT LOOK TO BE OPTIMAL FOR WINDS BEING TOO STRONG.
BORSUM
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
EXTENDED FORECAST REMAINS UNCHANGED FOR THE END OF THE WEEKEND
THROUGH THE MIDDLE OF NEXT WEEK. THE PATTERN REMAINS THE SAME WITH
WEAK DISTURBANCES MOVING ACROSS THE FORECAST AREA FOLLOWED BY
BRIEF RIDGING ALONG WITH PERIODS OF WINDS ACROSS OUR WESTERN
AREAS. A DISTURBANCE MOVING ACROSS THE NORTHERN PORTIONS OF THE
STATE SATURDAY NIGHT INTO SUNDAY WILL FLATTEN SATURDAYS RIDGE
BRINGING A NORTHWEST FLOW ALOFT TO THE FORECAST AREA SUNDAY.
RIDGING BUILDS AGAIN FOR MONDAY ALONG WITH SOME WEAK LEE-SIDE
TROUGHING. A FAST ZONAL FLOW ALOFT MOVES ACROSS THE FORECAST AREA
TUESDAY BEFORE STRONGER RIDGING BUILDS WEDNESDAY INTO THURSDAY AS
A LARGE TROUGH MOVES ONTO THE WEST COAST. PRECIP CHANCES WILL
MOSTLY BE CONFINED TO MOUNTAIN SNOW SHOWERS...MAINLY THE WEST
FACING SLOPES OF THE BEARTOOTH/ABSAROKAS. TEMPERATURES WILL RUN
WELL ABOVE NORMAL WITH READINGS IN THE 40S AND 50S...WITH A 60
DEGREE READING NOT OUT OF THE QUESTION BY NEXT WEDNESDAY OR
THURSDAY. HOOLEY
&&
.AVIATION...
SKIES WILL BE MOSTLY CLOUDY OVERNIGHT AS MID AND HIGH LEVEL
CLOUDS MOVE ACROSS THE FORECAST AREA. A SLIGHT CHANCE FOR A
SPRINKLE OR FLURRY WILL EXIST. HOWEVER...NO AVIATION HAZARDS ARE
EXPECTED AS VFR CONDITIONS WILL PREVAIL. SNOW SHOWERS WILL
CONTINUE OVER THE MOUNTAINS RESULTING IN MOUNTAIN OBSCURATIONS AT
TIMES. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 027/038 024/045 031/045 026/045 030/046 030/049 032/050
11/E 00/B 10/N 00/B 12/W 11/B 11/B
LVM 032/046 031/048 032/044 029/046 034/045 034/047 034/048
11/E 01/N 11/N 00/B 12/W 11/N 11/B
HDN 021/037 018/044 026/044 022/044 025/047 028/049 025/050
11/E 00/B 00/U 00/B 01/B 11/B 10/B
MLS 015/030 018/039 027/040 020/040 025/043 027/046 028/047
21/B 00/B 11/B 00/U 01/B 11/U 10/B
4BQ 019/037 021/043 026/043 020/043 025/045 026/047 027/048
11/B 00/B 11/B 00/U 00/B 00/B 00/B
BHK 015/029 016/036 025/038 020/036 023/043 028/044 030/045
30/B 10/B 11/B 10/B 01/B 00/B 00/B
SHR 024/043 022/046 025/045 022/043 026/047 026/049 026/050
01/B 00/B 10/U 00/U 00/B 10/B 00/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
928 PM MST WED DEC 3 2014
.UPDATE...
SOME SIGNIFICANT UPDATES TO THE FORECAST THIS EVENING. LATEST
MODEL RUNS HAVE POINTED A STRONG SURGE OF MID LEVEL (H7-H5)
MOISTURE INTO THE AREA LATE TONIGHT THROUGH THE DAY TOMORROW. THIS
MOISTURE IS ALREADY IMPACTING OUR WESTERN MOUNTAINS WITH SNOW
BASED ON THE COOKE CITY WEB CAM AND SNOTEL MEASUREMENTS. LATEST
MET GUIDANCE BUMPED PRECIPITATION CHANCES WAY UP FROM ITS PREVIOUS
RUNS AND HRRR SHOWING INCREASED PRECIPITATION LEE OF THE MOUNTAINS
FOR TOMORROW. AS A RESULT OF THIS MOISTURE PUSH HAVE INCREASED
MOUNTAIN POPS TO CATEGORICAL FOR WEST FACING SLOPES WITH
CHANCE POPS FOR THE EASTERN SIDE. BROUGHT LOW POPS INTO WESTERN
VALLEYS BY SUNRISE AND SPREAD THEM EAST INTO ROSEBUD COUNTY BY
LATE MORNING. THERE IS A STRONG DOWNSLOPE WIND ASSOCIATED WITH
THIS SYSTEM BUT MODELS ALL CONSISTENT WITH SEEING SOME LIGHT
PRECIPITATION MAKING IT TO THE GROUND TOMORROW.
NEXT CHALLENGE IS PRECIPITATION TYPE WITH LOWER RIVER VALLEYS
CURRENTLY WELL BELOW FREEZING WHILE MANY HILLTOP LOCATIONS ARE AT
OR ABOVE FREEZING. WITH CLOUD COVER INCREASING TEMPERATURES
PROBABLY WON`T GO A WHOLE LOT LOWER THAN CURRENT READINGS.
WESTERLY WIND WILL BEGIN TO SCOUR OUT RIVER VALLEY COLD AIR
TOMORROW MORNING. THIS WILL LIKELY LEAD TO A MIX OF RAIN/FREEZING
RAIN/AND MAYBE SNOW ACROSS THE AREA DURING THE MORNING HOURS WITH
LOWEST VALLEYS SEEING THE BEST SHOT AT FREEZING RAIN. THIS
INCLUDES THE YELLOWSTONE AND BIGHORN VALLEYS AND PORTIONS OF BOTH
I-90/I-94. IN ADDITION COULD SEE SOME RAIN FALL AT TEMPERATURES
ABOVE FREEZING BUT WITH FROZEN GROUND IT MAY FREEZE ON CONTACT
ANYWAY. THOSE TRAVELING IN THE MORNING SHOULD BE ALERT FOR ANY
RAIN AND TREAT IT AS FREEZING RAIN...EXPECTING SLICK ROADS UNTIL
LATE MORNING WHEN THE SUN SHOULD BRING UP ROAD TEMPERATURES ABOVE
FREEZING. BY AFTERNOON MOST PRECIPITATION NOT IN THE MOUNTAINS
WILL BE RAIN...BUT WILL NEED TO WATCH AREAS AROUND MILES CITY AND
BROADUS FOR ADDITIONAL FREEZING RAIN. CHAMBERS
&&
.SHORT TERM...VALID FOR THU AND FRI...
ROUND OF CLEARING OVER WESTERN AREAS THIS AFTERNOON HAS LET SOME
OF THE MOUNTAIN TEMPERATURES CLIMB BUT LOWER ELEVATIONS HAVE
STRUGGLED TO MIX OUT FULLY. SURFACE TROUGH LAYING OVER THE AREA
PROGGED TO LINGER OVERNIGHT WHICH WILL COMBINE WITH SURFACE HIGH
PRESSURE OVER YELLOWSTONE PARK TO SUPPORT A DOWNSLOPE FLOW FOR THE
WESTERN ZONES...ALBEIT LIGHT. WILL BE ENOUGH TO SUPPORT SOME
MILDER TEMPERATURES THAN PREVIOUS NIGHT BUT THE NORTH SIDE OF THE
TROUGH INCLUDING MOST OF SOUTHEAST MONTANA WILL APPROACH THE
SINGLE DIGITS AGAIN.
SECOND SURGE OF MOISTURE MOVING INTO SOUTHWEST IDAHO DOES SHIFT UP
INTO SOUTHWEST MONTANA TONIGHT WHICH WILL BRING A CHANCE FOR
MOUNTAIN SHOWER ACTIVITY. THE SURFACE TROUGH MOVES LITTLE TOMORROW
BUT THE DOWNSLOPE FLOW SHOULD BE MAINTAINED TO SUPPORT A WARMER
DAY ACROSS THE WESTERN ZONES. AN AMPLIFYING RIDGE OVER THE PACIFIC
NORTHWEST ALLOWS SURFACE HIGH PRESSURE OVER ALBERTA TO DESCEND
INTO NORTHEAST MONTANA THURSDAY NIGHT TIGHTENING UP GRADIENTS
ALONG THE SURFACE TROUGH AND PRODUCING A BIT OF WEAK
FRONTOGENESIS. OVERALL A VERY WEAK DYNAMIC SITUATION BUT ENOUGH TO
HAVE SOME ISOLATED POPS OFF OF THE MOUNTAINS ALONG THE PROJECTED
LOCATION OF THE BOUNDARY THURSDAY NIGHT INTO EARLY FRIDAY.
RIDGE AXIS SLIDING TOWARDS THE AREA ON FRIDAY DOES BEGIN TO MOVE
THE SURFACE TROUGH EASTWARD LATER IN THE DAY AND BRINGS IN DRYING
CONDITIONS. THIS WILL END THE CHANCE OF PRECIPITATION AND BRING
ANOTHER LITTLE PUSH IN THE TEMPERATURES UPWARDS. MODELS LOOK LIKE
THEY ARE TRYING TO DEVELOP A WIND PATTERN FOR GAP FLOW AREAS
FRIDAY NIGHT SO INCREASED WIND SPEEDS FOR THOSE AREAS. BORSUM
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
NO BIG STORM SYSTEMS LOOK ON THE HORIZON THROUGH THE EXTENDED
PERIOD. OVERALL...IT LOOKS TO BE QUIET WITH ABOVE NORMAL
TEMPERATURES. LARGE- SCALE WEATHER PATTERN WILL BE A RIDGE-TROUGH
PATTERN EVERY OTHER DAY OR SO. SATURDAY STARTS WITH A RIDGE BUT AN
UPPER LOW AND TROUGH MOVE ACROSS THE CANADIAN BORDER SATURDAY
NIGHT INTO SUNDAY. THIS WILL BRING A PERIOD OF WINDS TO THE AREA
BUT NOTHING STRONG AT THIS POINT ALONG WITH A SLIGHT CHANCE FOR
SHOWERS...MAINLY MOUNTAIN SNOW SHOWERS. RIDGING ARRIVES BRIEFLY
FOR MONDAY FOLLOWED BY ANOTHER WEAK WAVE FLATTENING THE RIDGE
TUESDAY INTO WEDNESDAY. MAIN THEME IS A FAST FLOW ALOFT WITH SNOW
SHOWER CHANCES MAINLY FOR THE WEST FACING SLOPES OF THE
BEARTOOTH/ABSAROKA MOUNTAINS. TEMPERATURES WILL RUN ON AVERAGE
ABOUT 10 DEGREES ABOVE NORMAL FOR MOST LOCATIONS ACROSS THE PLAINS
WITH READINGS IN THE 40S TO POSSIBLY 50 DEGREES. HOOLEY
&&
.AVIATION...
VFR WILL PREVAIL OVER THE AREA TONIGHT. ON THU...SCATTERED RAIN
AND SNOW SHOWERS MAY PRODUCE MVFR CONDITIONS W OF KBIL...INCLUDING
OVER KLVM. IN ADDITION...THERE WILL BE A SLIGHT CHANCE OF A MIX OF
RAIN...SNOW AND LIGHT FREEZING RAIN FROM ROSEBUD COUNTY W THU
MORNING. IN THE AFTERNOON...THERE WILL BE A SLIGHT CHANCE OF A MIX
OF RAIN...SNOW AND LIGHT FREEZING RAIN FROM KMLS W THROUGH N
ROSEBUD COUNTY. OTHERWISE...EXPECT VFR OVER THE AREA. SNOW
SHOWERS OVER THE MOUNTAINS WILL PRODUCE WIDESPREAD OBSCURATIONS
OVER THE BEARTOOTHS...ABSAROKAS AND CRAZYS TONIGHT THROUGH THU.
EXPECT AREAS OF OBSCURATION OVER THE NE BIGHORNS. ARTHUR
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 020/043 027/041 026/050 027/045 024/045 025/045 029/046
03/O 11/B 10/B 10/N 00/B 12/W 11/B
LVM 035/046 031/045 032/050 028/044 026/045 028/044 031/044
24/R 11/E 10/N 21/N 00/B 12/W 11/N
HDN 012/041 021/040 020/050 025/044 019/044 020/045 024/046
03/O 11/B 10/B 10/B 00/B 11/B 11/B
MLS 008/035 015/032 020/044 026/039 017/041 019/043 024/043
02/S 11/B 10/B 11/B 00/B 11/B 11/B
4BQ 014/041 020/038 024/044 026/041 018/043 020/044 024/044
01/B 11/B 10/B 11/B 00/U 01/B 00/B
BHK 010/038 014/030 018/040 026/036 015/036 018/040 024/041
01/B 01/B 10/U 11/N 00/B 01/B 00/B
SHR 010/046 024/043 022/049 023/045 021/043 022/047 023/045
02/O 11/B 00/B 10/B 00/B 01/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
600 PM CST FRI DEC 5 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 218 PM CST FRI DEC 5 2014
THE SHORT TERM FORECAST THROUGH SATURDAY IS RELATIVELY QUIET IN
TERMS OF MAJOR WEATHER ISSUES. MILD TEMPERATURES THIS AFTERNOON
WILL BE TEMPERED A BIT IN THE WAKE OF FRONTAL BOUNDARY PASSING
THROUGH THE FORECAST AREA AT THIS TIME. TEMPERATURES WILL ACTUALLY
BE NEAR NORMAL TONIGHT AND SATURDAY...THOUGH IT WILL FEEL QUITE A
BIT COOLER TONIGHT WITH UPPER TEENS AND 20S. DECENT MODEL AGREEMENT
WITH SOME LOWER CLOUDS TRYING TO SNEAK BACK WEST TONIGHT AND PUSH
INTO THE HIGHWAY 81 CORRIDOR AREA TOWARD DAWN SATURDAY AND LINGER
INTO THE MORNING. HAVE INCREASED CLOUDS IN THAT AREA...AND ADDED A
BIT OF PATCHY FOG FOG WHICH ALIGNS WELL WITH WFOS OMAHA AND TOPEKA
FORECAST. SOME CONCERN OF FOG IN THE NORTHWEST PART OF THE FORECAST
AREA...WHERE WINDS TURN NEARLY CALM. HRRR HINTS AT LOWER CLOUDS AND
VISIBILITY OVER PARTS OF THE SANDHILLS. WILL HOLD OFF FOR NOW BUT
WORTH NOTING HEADING INTO TONIGHT. BEYOND THAT...SATURDAY WILL SEE
MID/HIGH CLOUDS START TO INCREASE FROM THE WEST IN THE AFTERNOON AS
WARM ADVECTION INCREASES AHEAD OF NEXT WEATHER SYSTEM ON SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 218 PM CST FRI DEC 5 2014
GUIDANCE SUGGESTS THE LONG-TERM FORECAST PERIOD WILL START OFF WITH
UPPER TROPOSPHERIC RIDGING OVER THE CENTRAL CONUS AND A SUBTLE
TROUGH AXIS JUST WEST OF THE ROCKY MOUNTAINS AT 00Z SUNDAY. THIS
TROUGH AXIS IS EXPECTED TO SHIFT EAST SATURDAY NIGHT INTO
SUNDAY...WITH THIS TROUGH AXIS LIKELY CLEARING OUR AREA DURING THE
DAY SUNDAY. NORTHWESTERLY UPPER TROPOSPHERIC FLOW IS THEN EXPECTED
TO OVERTAKE THE CENTRAL CONUS THROUGH MUCH OF THE REMAINDER OF THE
LONG-TERM FORECAST PERIOD AS UPPER TROPOSPHERIC TROUGHING
STRENGTHENS OVER THE EASTERN CONUS AND RIDGING BUILDS ACROSS THE
WEST.
ALTHOUGH UNCERTAINTY REMAINS...THERE REMAIN HINTS AT A BRIEF PERIOD
OF PRECIPITATION PRODUCTION ACROSS THE CENTRAL PLAINS ON SUNDAY AS
TROPOSPHERIC MOISTURE AND UPPER TROPOSPHERIC THERMAL ADVECTION
INCREASES AHEAD OF THE APPROACHING TROUGH AXIS. QPF FIELDS FROM THE
NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL CONTINUE TO SUGGEST
LIGHT PRECIPITATION WILL BE REALIZED ACROSS PORTIONS OF OUR CWA ON
SUNDAY AND AS A RESULT...CONTINUED WITH POPS...ALBEIT LOW...ACROSS
MUCH OF THE AREA ON SUNDAY. UNFORTUNATELY PRECIPITATION TYPE REMAINS
QUESTIONABLE AS FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE
CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST AN ELEVATED WARM
LAYER WILL LIKELY PROVIDE LIQUID PRECIPITATION WHILE SURFACE
TEMPERATURE READINGS FALL TO NEAR OR BELOW FREEZING AROUND DAYBREAK
SUNDAY. PREVIOUS SHIFT WENT AHEAD AND INSERTED A MENTION OF LIGHT
FREEZING RAIN FOR A TIME SUNDAY MORNING AND AT THIS TIME...SEE NO
REASON TO REMOVE THIS WORDING. GIVEN ALL THIS...A SLIGHT CHANCE FOR
LIGHT FREEZING RAIN REMAINS IN THE FORECAST FOR MUCH OF THE AREA FOR
A FEW HOURS SUNDAY MORNING AROUND DAYBREAK...WITH LIGHT RAIN THEN
FORECAST BY 14Z AS SURFACE TEMPERATURE READINGS CLIMB ABOVE FREEZING.
THERE MAY ALSO BE A PERIOD OF LIGHT DRIZZLE OR LIGHT FREEZING
DRIZZLE ACROSS PORTIONS OF THE CWA SUNDAY MORNING...WITH GUIDANCE
SUGGESTING 0-1KM RELATIVE HUMIDITY VALUES NEAR 100% WILL ACCOMPANY 0-
1KM BULK SHEAR VALUES OF 25-30KTS. GIVEN THE POTENTIAL FOR A
SATURATED LOWER TROPOSPHERE AS WELL AS SUFFICIENT TURBULENT
MIXING...OPTED TO KEEP A MENTION OF LIGHT DRIZZLE AND LIGHT FREEZING
DRIZZLE GOING IN THE FORECAST FOR SUNDAY MORNING.
AN OVERALL LACK IN OMEGA SHOULD THEN KEEP US DRY THROUGH MUCH OF THE
REST OF THE LONG-TERM FORECAST PERIOD...ALTHOUGH THERE ARE HINTS OF
AN UPPER TROPOSPHERIC SHORT WAVE PERHAPS BRINGING A ROUND OF LIGHT
PRECIPITATION TO THE REGION ON FRIDAY AND AS A RESULT...WENT WITH A
LOW POP ACROSS PORTIONS OF THE CWA ON FRIDAY.
LITTLE IF ANY CHANGE IN BOUNDARY-LAYER AIR MASS SHOULD PRESENT
SIMILAR TEMPERATURE READINGS FROM DAY TO DAY DURING THE LONG-TERM
FORECAST PERIOD...WITH HIGHS IN THE UPPER 40S TO MID 50S AND LOW IN
THE UPPER 20S TO LOWER 30S CURRENTLY FORECAST FOR THE MOST PART.
&&
.AVIATION...(FOR THE 00Z KGRI/KEAR TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 559 PM CST FRI DEC 5 2014
VFR CONDITIONS. WIND WILL BECOME MORE EAST/SOUTHEAST SATURDAY. ANY
REDUCED VIS SHOULD STAY SOUTHEAST OF THE TERMINALS TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...NOAA/NWS/MORITZ
LONG TERM...BRYANT
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
535 PM CST FRI DEC 5 2014
.SYNOPSIS...
ISSUED AT 322 PM CST FRI DEC 5 2014
WEAK COLD FRONT STALLING NEAR THE KS/NEB BORDER THIS AFTERNOON.
MOSTLY SUNNY SKIES AND SOME 10 TO 15 MPH NORTHERLY WINDS BEHIND THE
FRONT HAVE ALLOWED FOR GOOD MIXING WITH TEMPERATURES IN THE UPPER
40S AND 50S. MEANWHILE HIGH PRESSURE IS SETTLING ACROSS THE NORTHERN
PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
TONIGHT HIGH PRESSURE WILL CONTINUE TO DRIFT ACROSS THE NORTHERN
PLAINS. THIS WILL CAUSE THE WINDS TO BECOME EASTERLY/SOUTHEASTERLY.
THIS WIND SWITCH WILL HELP TO USHER IN SOME LL MOISTURE. THIS WILL
COMBINE WITH MOSTLY CLEAR SKIES AND GOOD RADIATIONAL COOLING TO
PRODUCE LOWS IN THE TEENS AND MAYBE SOME PATCHY FOG. SOME CONCERNS
TOWARDS THE FOG DEVELOPMENT AS AFTERNOON TEMPS IN THE 50S MIXED THE
MOISTURE FAIRLY WELL. ALSO A VERY DRY SURFACE...LITTLE RAIN OVER THE
LAST MONTH ACROSS MOST OF THE AREA. THE NAM IS THE ONLY MODEL
SUGGESTING DEVELOPMENT...ALTHOUGH IT IS A LITTLE HIGH WITH CURRENT
DEW PTS. THE RUC IS LESS FAVORABLE...BUT IS CLOSER BUT IS A DEGREE
OR SO TO LOW WITH DEW PTS. THUS THE FORECAST DOES INCLUDE SOME
PATCHY FOG IN THE PLATTE RIVER VALLEY...WHICH IS LIKELY THE FIRST
PLACE FOR DEVELOPMENT ALTHOUGH CONFIDENCE IS LOW. HAVE ALSO INCLUDED
SOME FOG ACROSS THE FAR NORTHWEST...HOWEVER THERE IS BETTER GROUND
MOISTURE.
TOMORROW COOL HIGH PRESSURE CENTERED OVER MINNESOTA...HOWEVER WILL
SEE SOME COOLER TEMPS ALOFT /850 MB TEMPS AROUND 5C/ INTO THE HIGH
PLAINS. WILL KEEP TEMPS ABOUT 5 TO 10 DEGREES COOLER THAN TODAY.
LATELY THE WARMER MAV HAS BEEN CLOSER TO REALITY AND FAVORED THESE
WARMER NUMBERS FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
...ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS FORECAST SUNDAY
THROUGH FRIDAY...
MID RANGE PERIODS (SATURDAY NIGHT THROUGH MONDAY)...
THE UPPER TROUGH EXITING THE ROCKIES WILL MOVE ACROSS WESTERN
NEBRASKA SATURDAY NIGHT INTO SUNDAY. WHILE MOISTURE WILL BE AMPLE
FROM H7 TO H5...H85 TO H7 RELATIVELY DRY. CONCERN LIES IN
SATURATED LAYER BELOW 875 MB. WITH WEAK OMEGA PRESENT ALONG WITH
SUPERCOOLED DROPLETS OF -1C TO -3C...INTRODUCED PATCHY FREEZING
FRIZZLE WHICH IS POSSIBLE FROM 09Z TO 15Z SUNDAY. SURFACE
TEMPERATURES DURING THIS TIME SHOULD RANGE FROM 28 TO 32 DEGREES.
THE AREA MAY AFFECT SOUTHEASTERN AREAS MAINLY EAST OF A CURTIS
THROUGH CALLAWAY AND STUART LINE. OTHERWISE CLEARING SKIES FROM
WEST TO EAST ON SUNDAY WITH ANOTHER NICE WARMUP. DOWNSLOPING WEST
TO NORTHWEST WINDS 5 TO 15 MPH SHOULD PUSH HIGHS UP INTO THE LOWER
TO MID 50S...EXCEPT COOLER UPPER 40S NEAR ONEILL AND BARTLETT. A
WEAK COLD FRONT SUNDAY NIGHT. HIGHS MONDAY HOWEVER WILL REMAIN
VERY SIMILAR TO SUNDAY.
EXTENDED PERIODS (MONDAY NIGHT THROUGH FRIDAY)...
THE MILD CONDITIONS WILL PERSIST IN THE EXTENDED PERIODS AS UPPER
RIDGING DOMINATES THE CENTRAL CONUS. INCREASED TROUGHING ONTO THE
WEST COAST WILL ALSO HELP TO AMPLIFY DOWNSTREAM RIDGE.
UPPER RIDGING WILL BUILD INTO THE CENTRAL CONUS WEDNESDAY THROUGH
FRIDAY WITH HIGHS IN THE 50S. SOME HIGHS IN THE WEST COULD EXCEED
60 DEGREES WEDNESDAY AND BEYOND. BY FRIDAY...A STRONG UPPER
TROUGH WILL MOVE ONTO THE WEST COAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 535 PM CST FRI DEC 5 2014
MAINLY CLEAR SKIES ARE EXPECTED TONIGHT ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA. SOME PATCHY FOG IS POSSIBLE TOWARD SUNRISE
SATURDAY IN THE PLATTE RIVER VALLEY. THIS MAY IMPACT THE KLBF
TERMINAL WITH VISBYS DOWN TO 3SM. LOOK FOR HIGH CLOUDINESS TO
INCREASE LATE SATURDAY MORNING...WITH BROKEN CIGS AROUND 25000 FT
AGL EXPECTED DURING THE LATE AFTERNOON HOURS. WINDS WILL BE LIGHT
AND VARIABLE AT UNDER 10 KTS TONIGHT...BECOMING SOUTH AND
INCREASING TO 10 TO 15 KTS SATURDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...ROBERG
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1146 AM CST THU DEC 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU DEC 4 2014
ITS BEEN ANOTHER NIGHT WITH QUIET CONDITIONS ACROSS THE
REGION...WITH UPPER AIR AND SATELLITE DATA SHOWING ZONAL FLOW
REMAINING IN PLACE ACROSS A GOOD CHUNK OF THE CONUS...AND NO
NOTABLE DISTURBANCES IN THE AREA. OVER THE WEST
COAST...SATELLITE IMAGERY SHOWS A COUPLE OF DISTURBANCES...ONE TO
THE NORTH AND ANOTHER JUST MAKING ITS WAY ONTO THE FAR SRN
PORTIONS. THAT SRN DISTURBANCE BEARS WATCHING THROUGH THE SHORT
TERM PERIOD. UPPER LEVEL CIRRUS CONTINUES TO STREAM INTO THE AREA
FROM THE WEST...CURRENTLY RESULTING IN PARTLY/MOSTLY CLOUDY SKIES
TO THE SWRN CWA AND MOSTLY CLEAR SKIES TO THE NERN CWA. AT THE
SURFACE...THE CWA REMAINS SET UP BETWEEN HIGH PRESSURE OVER THE
MIDWEST REGION AND LOW PRESSURE DRAPED THROUGH THE HIGH
PLAINS...KEEPING THE SRLY WINDS IN PLACE...SPEEDS ARE GENERALLY IN
THE 5 TO 10 MPH RANGE. TEMPS AS OF 3 AM ARE MAINLY IN THE
20S...THOUGH A FEW LOWER 30S ARE IN PLACE ACROSS SWRN PORTIONS OF
THE CWA.
DURING THE DAYTIME HOURS TODAY...OVERALL THERE WERENT ANY NOTABLE
CHANGES MADE TO THE FORECAST...WHICH REMAINS DRY. MODELS ARE IN
GOOD AGREEMENT SHOWING LITTLE CHANGE WITH THE UPPER LEVEL
PATTERN...THOUGH THAT ABOVE MENTIONED SWRN COAST DISTURBANCE
CONTINUES TO MAKE ITS WAY EAST...BY 00Z THIS EVENING IT LOOKS TO
HAVE PUSHED JUST EAST OF THE 4 CORNERS REGION. SAME GOES FOR THE
SFC PATTERN...LITTLE CHANGE...AND THOSE SRLY WINDS
CONTINUE...TOPPING OUT AROUND 10 MPH. STILL LOOKING AT A BUMP UP
IN TEMPERATURES TODAY...WITH MODELS REMAINING IN GOOD AGREEMENT
SHOWING WARMER AIR ALOFT BUILDING IN FROM THE WEST. DID BUMP UP
HIGHS A TOUCH...WITH MID 40S EAST TO LOWER 50S WEST. NOT QUITE AS
HIGH AS THE RAP SUGGESTS...SO THAT WILL BE SOMETHING FOR THE DAY
CREW TO MONITOR...SEE HOW THIS MORNING TEMPS ARE TRENDING.
TONIGHT...THE MAIN CHANGE MADE TO THE FORECAST WAS TO RAISE POPS
ACROSS THE SRN CWA /MAINLY OUR KS COUNTIES/. LATEST MODEL RUNS ARE
IN PRETTY GOOD AGREEMENT SHOWING THAT UPPER LEVEL DISTURBANCE
CONTINUING TO MAKE ITS WAY TO THE EAST...CROSSING PRIMARILY OVER
KS DURING THE OVERNIGHT HOURS. CONTINUING TO KEEP THE EARLY
EVENING HOURS DRY...WITH PRECIPITATION CHANCES STARTING TO CREEP
FURTHER NORTH INTO OUR FAR SOUTH AS WE GET TOWARD MIDNIGHT. AT
THIS POINT THE BEST CHANCES LOOK TO COME BETWEEN 06-12Z...AND
BUMPED UP POPS ACROSS NC KS INTO THE 30-70 PERCENT RANGE. HAVE
SOME 20-30 POPS AFFECTING THE FAR SRN ROW OF NEB COUNTIES AS WELL.
WILL HAVE TO SEE HOW THE 12Z RUN OF MODELS TREND...THE 06Z NAM
SUGGESTS POPS NEED TO BE EXPANDED FURTHER NORTH.
THANKFULLY...STILL LOOKING FOR THIS TO BE AN ALL LIQUID EVENT.
THOUGH TEMPS WILL BE FALLING THROUGH THE EVENING HOURS...EXPECTING
THAT AS THE INCREASED CLOUD COVER/PRECIP MOVES INTO THE
AREA...TEMPS SHOULD LEVEL OUT/IF NOT RISE A FEW DEGREES...AND
EXPECTING A COLD RAIN WITH TEMPS IN THE MID 30S...THOUGH UPPER
30S/NEAR 40 NOT OUT OF THE QUESTION.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU DEC 4 2014
THE EXTENDED PERIODS WILL SEE SOME CHCS FOR PCPN EARLY ON...WHILE
TEMPERATURES REMAIN ON THE MILD SIDE.
RAIN (NOT SNOW!) WHICH DEVELOPS OVERNIGHT TONIGHT IS EXPECTED TO
BE ONGOING BUT WINDING DOWN ACROSS OUR SOUTHEAST CWA FRIDAY
MORNING AS A CLOSED H7 LOW ACROSS NORTHERN KS FILLS AND TRANSLATES
EASTWARD. PRECIPITATION CHCS END ACROSS OUR SOUTHERN ZONES W/E AS
THE TROUGH AXIS PASSES DURING THE MORNING. HAVE MAINTAINED FOG
POTENTIAL FOR THE FIRST PART OF THE DAY IN THE PRESENCE OF LOW
CLOUDS/LLVL MOISTURE UNTIL THE SFC COLD FRONTAL BOUNDARY MOVES
THRU DURING THE MORNING...SCOURING THE LLVL MOISTURE. EXPECT THE
COLD AIR ADVECTION BEHIND THE FRONT TO BE OFFSET BY THE INCREASE
IN INSOLATION AND HAVE ONLY MADE MINOR ADJUSTMENTS TO HIGHS.
A STRONG SFC HIGH PRESSURE SYSTEM BUILDS SOUTH FROM THE DAKOTAS
ONTO THE PLAINS BEHIND THE COLD FRONT FRIDAY/FRIDAY
NIGHT...WHICH WILL RESULT IN A CHILLY NIGHT WITH LOWS IN THE
TEENS/20S. THE CENTER OF THE SFC HIGH MOVES INTO MN DURING THE DAY
ON SATURDAY WITH RETURN FLOW OF EAST/SOUTHEASTERLY WINDS SETTING
UP ACROSS OUR REGION. THE LLVL MOISTURE/STRATUS IS PROGGED TO
MIGRATE WESTWARD IN THE EASTERLY LLVL FLOW. 00Z MODELS SUGGESTED
THE LOW CLOUDS COULD REACH OUR EASTERN ZONES DURING THE DAY AND
EFFECTIVELY STALL TEMPS...BUT 06Z TRENDS KEEP THE BRUNT OF THIS
JUST TO OUR EAST.
BY SATURDAY NIGHT THE CLOUD COVER THICKENS AHEAD OF A SHORTWAVE
TROUGH MOVING EAST OF THE ROCKIES AND ONTO THE PLAINS. ISENTROPIC
LIFT INCREASES AHEAD OF THIS SYSTEM AND WE COULD SEE SOME LIGHT
PCPN DEVELOPING WITH MODEL FORECAST SOUNDINGS THE POTENTIAL FOR
FREEZING DRIZZLE INITIALLY UNTIL LLVL TEMPS RISE. CONFIDENCE IS
NOT HIGH ENOUGH TO MENTION FREEZING PCPN THIS FAR OUT AND HAVE
WENT WITH SILENT POPS FOR NOW.
THE EXTENDED INIT REINTRODUCED POPS INTO THE SUNDAY TIME FRAME AS
THE SYSTEM MOVES THRU...WHICH FAVORS A LIQUID EVENT DURING THE
DAYTIME HOURS. THE FORECAST DRIES OUT SUNDAY NIGHT BEHIND THE
DEPARTING TROUGH AND REMAINS DRY THRU WEDNESDAY. A CLIPPER
SYSTEM/TROUGH MOVING THRU THE UPPER MIDWEST/GREAT LAKES REGION
WILL BACK IN SOME SLIGHTLY COOLER AIR INTO OUR NORTHEAST ZONES
HEADING INTO MONDAY. A DRY AND MILD AIRMASS NEXT WEEK WILL RESULT
IN ABOVE NORMAL TEMPS THRU WEDNESDAY WITH HIGHS AVERAGING IN THE
40S/50.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1146 AM CST THU DEC 4 2014
VFR CONDITIONS CURRENTLY FORECAST THROUGH THE NEXT 24 HOURS.
CLOUD COVER WILL PERSIST THROUGH THE TAF PERIOD...BUT FOR THE
MOST PART NOTHING BELOW 15000FT AGL SHOULD BE OBSERVED. THAT
SAID...THERE IS ONE SET OF GUIDANCE WHICH SUGGESTS A BRIEF PERIOD
OF MVFR TO IFR CEILING COULD BE REALIZED FRIDAY MORNING AFTER
SUNRISE. HOWEVER...CONFIDENCE IS TOO LOW TO INTRODUCE ANY SUCH
CEILING IN EITHER TAF...BUT STILL SOMETHING TO MONITOR THROUGH THE
NEXT 24 HOURS. PRECIPITATION WILL LIKELY SPREAD INTO KANSAS AND
SOUTH/SOUTHEASTERN NEBRASKA TONIGHT INTO FRIDAY MORNING...BUT AT
THIS TIME ANY PRECIPITATION IS EXPECTED TO REMAIN SOUTHEAST OF
KEAR AND KGRI. THE SURFACE WIND WILL REMAIN FAIRLY LIGHT FROM THE
SOUTH...SUSTAINED AT AROUND 10KTS...THROUGH MUCH OF THE TAF PERIOD
BEFORE BECOMING VARIABLE AFTER 12Z FRIDAY. VISIBILITY RESTRICTION
IS NOT CURRENTLY EXPECTED AT EITHER TAF SITE THROUGH THE NEXT 24
HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...FAY
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
532 AM CST THU DEC 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU DEC 4 2014
ITS BEEN ANOTHER NIGHT WITH QUIET CONDITIONS ACROSS THE
REGION...WITH UPPER AIR AND SATELLITE DATA SHOWING ZONAL FLOW
REMAINING IN PLACE ACROSS A GOOD CHUNK OF THE CONUS...AND NO
NOTABLE DISTURBANCES IN THE AREA. OVER THE WEST
COAST...SATELLITE IMAGERY SHOWS A COUPLE OF DISTURBANCES...ONE TO
THE NORTH AND ANOTHER JUST MAKING ITS WAY ONTO THE FAR SRN
PORTIONS. THAT SRN DISTURBANCE BEARS WATCHING THROUGH THE SHORT
TERM PERIOD. UPPER LEVEL CIRRUS CONTINUES TO STREAM INTO THE AREA
FROM THE WEST...CURRENTLY RESULTING IN PARTLY/MOSTLY CLOUDY SKIES
TO THE SWRN CWA AND MOSTLY CLEAR SKIES TO THE NERN CWA. AT THE
SURFACE...THE CWA REMAINS SET UP BETWEEN HIGH PRESSURE OVER THE
MIDWEST REGION AND LOW PRESSURE DRAPED THROUGH THE HIGH
PLAINS...KEEPING THE SRLY WINDS IN PLACE...SPEEDS ARE GENERALLY IN
THE 5 TO 10 MPH RANGE. TEMPS AS OF 3 AM ARE MAINLY IN THE
20S...THOUGH A FEW LOWER 30S ARE IN PLACE ACROSS SWRN PORTIONS OF
THE CWA.
DURING THE DAYTIME HOURS TODAY...OVERALL THERE WERENT ANY NOTABLE
CHANGES MADE TO THE FORECAST...WHICH REMAINS DRY. MODELS ARE IN
GOOD AGREEMENT SHOWING LITTLE CHANGE WITH THE UPPER LEVEL
PATTERN...THOUGH THAT ABOVE MENTIONED SWRN COAST DISTURBANCE
CONTINUES TO MAKE ITS WAY EAST...BY 00Z THIS EVENING IT LOOKS TO
HAVE PUSHED JUST EAST OF THE 4 CORNERS REGION. SAME GOES FOR THE
SFC PATTERN...LITTLE CHANGE...AND THOSE SRLY WINDS
CONTINUE...TOPPING OUT AROUND 10 MPH. STILL LOOKING AT A BUMP UP
IN TEMPERATURES TODAY...WITH MODELS REMAINING IN GOOD AGREEMENT
SHOWING WARMER AIR ALOFT BUILDING IN FROM THE WEST. DID BUMP UP
HIGHS A TOUCH...WITH MID 40S EAST TO LOWER 50S WEST. NOT QUITE AS
HIGH AS THE RAP SUGGESTS...SO THAT WILL BE SOMETHING FOR THE DAY
CREW TO MONITOR...SEE HOW THIS MORNING TEMPS ARE TRENDING.
TONIGHT...THE MAIN CHANGE MADE TO THE FORECAST WAS TO RAISE POPS
ACROSS THE SRN CWA /MAINLY OUR KS COUNTIES/. LATEST MODEL RUNS ARE
IN PRETTY GOOD AGREEMENT SHOWING THAT UPPER LEVEL DISTURBANCE
CONTINUING TO MAKE ITS WAY TO THE EAST...CROSSING PRIMARILY OVER
KS DURING THE OVERNIGHT HOURS. CONTINUING TO KEEP THE EARLY
EVENING HOURS DRY...WITH PRECIPITATION CHANCES STARTING TO CREEP
FURTHER NORTH INTO OUR FAR SOUTH AS WE GET TOWARD MIDNIGHT. AT
THIS POINT THE BEST CHANCES LOOK TO COME BETWEEN 06-12Z...AND
BUMPED UP POPS ACROSS NC KS INTO THE 30-70 PERCENT RANGE. HAVE
SOME 20-30 POPS AFFECTING THE FAR SRN ROW OF NEB COUNTIES AS WELL.
WILL HAVE TO SEE HOW THE 12Z RUN OF MODELS TREND...THE 06Z NAM
SUGGESTS POPS NEED TO BE EXPANDED FURTHER NORTH.
THANKFULLY...STILL LOOKING FOR THIS TO BE AN ALL LIQUID EVENT.
THOUGH TEMPS WILL BE FALLING THROUGH THE EVENING HOURS...EXPECTING
THAT AS THE INCREASED CLOUD COVER/PRECIP MOVES INTO THE
AREA...TEMPS SHOULD LEVEL OUT/IF NOT RISE A FEW DEGREES...AND
EXPECTING A COLD RAIN WITH TEMPS IN THE MID 30S...THOUGH UPPER
30S/NEAR 40 NOT OUT OF THE QUESTION.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU DEC 4 2014
THE EXTENDED PERIODS WILL SEE SOME CHCS FOR PCPN EARLY ON...WHILE
TEMPERATURES REMAIN ON THE MILD SIDE.
RAIN (NOT SNOW!) WHICH DEVELOPS OVERNIGHT TONIGHT IS EXPECTED TO
BE ONGOING BUT WINDING DOWN ACROSS OUR SOUTHEAST CWA FRIDAY
MORNING AS A CLOSED H7 LOW ACROSS NORTHERN KS FILLS AND TRANSLATES
EASTWARD. PRECIPITATION CHCS END ACROSS OUR SOUTHERN ZONES W/E AS
THE TROUGH AXIS PASSES DURING THE MORNING. HAVE MAINTAINED FOG
POTENTIAL FOR THE FIRST PART OF THE DAY IN THE PRESENCE OF LOW
CLOUDS/LLVL MOISTURE UNTIL THE SFC COLD FRONTAL BOUNDARY MOVES
THRU DURING THE MORNING...SCOURING THE LLVL MOISTURE. EXPECT THE
COLD AIR ADVECTION BEHIND THE FRONT TO BE OFFSET BY THE INCREASE
IN INSOLATION AND HAVE ONLY MADE MINOR ADJUSTMENTS TO HIGHS.
A STRONG SFC HIGH PRESSURE SYSTEM BUILDS SOUTH FROM THE DAKOTAS
ONTO THE PLAINS BEHIND THE COLD FRONT FRIDAY/FRIDAY
NIGHT...WHICH WILL RESULT IN A CHILLY NIGHT WITH LOWS IN THE
TEENS/20S. THE CENTER OF THE SFC HIGH MOVES INTO MN DURING THE DAY
ON SATURDAY WITH RETURN FLOW OF EAST/SOUTHEASTERLY WINDS SETTING
UP ACROSS OUR REGION. THE LLVL MOISTURE/STRATUS IS PROGGED TO
MIGRATE WESTWARD IN THE EASTERLY LLVL FLOW. 00Z MODELS SUGGESTED
THE LOW CLOUDS COULD REACH OUR EASTERN ZONES DURING THE DAY AND
EFFECTIVELY STALL TEMPS...BUT 06Z TRENDS KEEP THE BRUNT OF THIS
JUST TO OUR EAST.
BY SATURDAY NIGHT THE CLOUD COVER THICKENS AHEAD OF A SHORTWAVE
TROUGH MOVING EAST OF THE ROCKIES AND ONTO THE PLAINS. ISENTROPIC
LIFT INCREASES AHEAD OF THIS SYSTEM AND WE COULD SEE SOME LIGHT
PCPN DEVELOPING WITH MODEL FORECAST SOUNDINGS THE POTENTIAL FOR
FREEZING DRIZZLE INITIALLY UNTIL LLVL TEMPS RISE. CONFIDENCE IS
NOT HIGH ENOUGH TO MENTION FREEZING PCPN THIS FAR OUT AND HAVE
WENT WITH SILENT POPS FOR NOW.
THE EXTENDED INIT REINTRODUCED POPS INTO THE SUNDAY TIME FRAME AS
THE SYSTEM MOVES THRU...WHICH FAVORS A LIQUID EVENT DURING THE
DAYTIME HOURS. THE FORECAST DRIES OUT SUNDAY NIGHT BEHIND THE
DEPARTING TROUGH AND REMAINS DRY THRU WEDNESDAY. A CLIPPER
SYSTEM/TROUGH MOVING THRU THE UPPER MIDWEST/GREAT LAKES REGION
WILL BACK IN SOME SLIGHTLY COOLER AIR INTO OUR NORTHEAST ZONES
HEADING INTO MONDAY. A DRY AND MILD AIRMASS NEXT WEEK WILL RESULT
IN ABOVE NORMAL TEMPS THRU WEDNESDAY WITH HIGHS AVERAGING IN THE
40S/50.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 525 AM CST THU DEC 4 2014
QUIET WEATHER AND VFR CONDITIONS CONTINUE IN THE FORECAST FOR THIS
TAF PERIOD...THOUGH WILL HAVE TO WATCH THE OVERNIGHT HOURS FOR
A DISTURBANCE MOVING ONTO THE PLAINS. THIS DISTURBANCE IS GOING TO
BRING RAIN CHANCES TO THE REGION...BUT AT THIS POINT THE BETTER
CHANCES LOOK TO REMAIN JUST OFF TO THE SOUTH OF THE TERMINAL
AREAS. EXPECTING CLOUD COVER THROUGH THE PERIOD TO BE CONFINED TO
THE MID/UPPER LEVELS...AND THOUGH THERE IS THE POTENTIAL FOR SOME
PATCHY FOG TO DEVELOP TONIGHT...THINKING THAT AGAIN THE TERMINALS
WOULD BE ON THE EDGE OF THE MAIN AREA...SO CONFIDENCE AT THIS TIME
IS NOT HIGH ENOUGH TO INSERT A MENTION IN THE TAF. REALLY NOT
LOOKING AT A SIGNIFICANT CHANGE IN WINDS THROUGH THE
PERIOD...REMAINING S/SWRLY WITH SPEEDS TOPPING OUT AROUND 10 MPH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...FAY
AVIATION...ADP
AREA FORECAST DISCUSSION
NWS HASTINGS NE
351 AM CST THU DEC 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU DEC 4 2014
ITS BEEN ANOTHER NIGHT WITH QUIET CONDITIONS ACROSS THE
REGION...WITH UPPER AIR AND SATELLITE DATA SHOWING ZONAL FLOW
REMAINING IN PLACE ACROSS A GOOD CHUNK OF THE CONUS...AND NO
NOTABLE DISTURBANCES IN THE AREA. OVER THE WEST
COAST...SATELLITE IMAGERY SHOWS A COUPLE OF DISTURBANCES...ONE TO
THE NORTH AND ANOTHER JUST MAKING ITS WAY ONTO THE FAR SRN
PORTIONS. THAT SRN DISTURBANCE BEARS WATCHING THROUGH THE SHORT
TERM PERIOD. UPPER LEVEL CIRRUS CONTINUES TO STREAM INTO THE AREA
FROM THE WEST...CURRENTLY RESULTING IN PARTLY/MOSTLY CLOUDY SKIES
TO THE SWRN CWA AND MOSTLY CLEAR SKIES TO THE NERN CWA. AT THE
SURFACE...THE CWA REMAINS SET UP BETWEEN HIGH PRESSURE OVER THE
MIDWEST REGION AND LOW PRESSURE DRAPED THROUGH THE HIGH
PLAINS...KEEPING THE SRLY WINDS IN PLACE...SPEEDS ARE GENERALLY IN
THE 5 TO 10 MPH RANGE. TEMPS AS OF 3 AM ARE MAINLY IN THE
20S...THOUGH A FEW LOWER 30S ARE IN PLACE ACROSS SWRN PORTIONS OF
THE CWA.
DURING THE DAYTIME HOURS TODAY...OVERALL THERE WERENT ANY NOTABLE
CHANGES MADE TO THE FORECAST...WHICH REMAINS DRY. MODELS ARE IN
GOOD AGREEMENT SHOWING LITTLE CHANGE WITH THE UPPER LEVEL
PATTERN...THOUGH THAT ABOVE MENTIONED SWRN COAST DISTURBANCE
CONTINUES TO MAKE ITS WAY EAST...BY 00Z THIS EVENING IT LOOKS TO
HAVE PUSHED JUST EAST OF THE 4 CORNERS REGION. SAME GOES FOR THE
SFC PATTERN...LITTLE CHANGE...AND THOSE SRLY WINDS
CONTINUE...TOPPING OUT AROUND 10 MPH. STILL LOOKING AT A BUMP UP
IN TEMPERATURES TODAY...WITH MODELS REMAINING IN GOOD AGREEMENT
SHOWING WARMER AIR ALOFT BUILDING IN FROM THE WEST. DID BUMP UP
HIGHS A TOUCH...WITH MID 40S EAST TO LOWER 50S WEST. NOT QUITE AS
HIGH AS THE RAP SUGGESTS...SO THAT WILL BE SOMETHING FOR THE DAY
CREW TO MONITOR...SEE HOW THIS MORNING TEMPS ARE TRENDING.
TONIGHT...THE MAIN CHANGE MADE TO THE FORECAST WAS TO RAISE POPS
ACROSS THE SRN CWA /MAINLY OUR KS COUNTIES/. LATEST MODEL RUNS ARE
IN PRETTY GOOD AGREEMENT SHOWING THAT UPPER LEVEL DISTURBANCE
CONTINUING TO MAKE ITS WAY TO THE EAST...CROSSING PRIMARILY OVER
KS DURING THE OVERNIGHT HOURS. CONTINUING TO KEEP THE EARLY
EVENING HOURS DRY...WITH PRECIPITATION CHANCES STARTING TO CREEP
FURTHER NORTH INTO OUR FAR SOUTH AS WE GET TOWARD MIDNIGHT. AT
THIS POINT THE BEST CHANCES LOOK TO COME BETWEEN 06-12Z...AND
BUMPED UP POPS ACROSS NC KS INTO THE 30-70 PERCENT RANGE. HAVE
SOME 20-30 POPS AFFECTING THE FAR SRN ROW OF NEB COUNTIES AS WELL.
WILL HAVE TO SEE HOW THE 12Z RUN OF MODELS TREND...THE 06Z NAM
SUGGESTS POPS NEED TO BE EXPANDED FURTHER NORTH.
THANKFULLY...STILL LOOKING FOR THIS TO BE AN ALL LIQUID EVENT.
THOUGH TEMPS WILL BE FALLING THROUGH THE EVENING HOURS...EXPECTING
THAT AS THE INCREASED CLOUD COVER/PRECIP MOVES INTO THE
AREA...TEMPS SHOULD LEVEL OUT/IF NOT RISE A FEW DEGREES...AND
EXPECTING A COLD RAIN WITH TEMPS IN THE MID 30S...THOUGH UPPER
30S/NEAR 40 NOT OUT OF THE QUESTION.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU DEC 4 2014
THE EXTENDED PERIODS WILL SEE SOME CHCS FOR PCPN EARLY ON...WHILE
TEMPERATURES REMAIN ON THE MILD SIDE.
RAIN (NOT SNOW!) WHICH DEVELOPS OVERNIGHT TONIGHT IS EXPECTED TO
BE ONGOING BUT WINDING DOWN ACROSS OUR SOUTHEAST CWA FRIDAY
MORNING AS A CLOSED H7 LOW ACROSS NORTHERN KS FILLS AND TRANSLATES
EASTWARD. PRECIPITATION CHCS END ACROSS OUR SOUTHERN ZONES W/E AS
THE TROUGH AXIS PASSES DURING THE MORNING. HAVE MAINTAINED FOG
POTENTIAL FOR THE FIRST PART OF THE DAY IN THE PRESENCE OF LOW
CLOUDS/LLVL MOISTURE UNTIL THE SFC COLD FRONTAL BOUNDARY MOVES
THRU DURING THE MORNING...SCOURING THE LLVL MOISTURE. EXPECT THE
COLD AIR ADVECTION BEHIND THE FRONT TO BE OFFSET BY THE INCREASE
IN INSOLATION AND HAVE ONLY MADE MINOR ADJUSTMENTS TO HIGHS.
A STRONG SFC HIGH PRESSURE SYSTEM BUILDS SOUTH FROM THE DAKOTAS
ONTO THE PLAINS BEHIND THE COLD FRONT FRIDAY/FRIDAY
NIGHT...WHICH WILL RESULT IN A CHILLY NIGHT WITH LOWS IN THE
TEENS/20S. THE CENTER OF THE SFC HIGH MOVES INTO MN DURING THE DAY
ON SATURDAY WITH RETURN FLOW OF EAST/SOUTHEASTERLY WINDS SETTING
UP ACROSS OUR REGION. THE LLVL MOISTURE/STRATUS IS PROGGED TO
MIGRATE WESTWARD IN THE EASTERLY LLVL FLOW. 00Z MODELS SUGGESTED
THE LOW CLOUDS COULD REACH OUR EASTERN ZONES DURING THE DAY AND
EFFECTIVELY STALL TEMPS...BUT 06Z TRENDS KEEP THE BRUNT OF THIS
JUST TO OUR EAST.
BY SATURDAY NIGHT THE CLOUD COVER THICKENS AHEAD OF A SHORTWAVE
TROUGH MOVING EAST OF THE ROCKIES AND ONTO THE PLAINS. ISENTROPIC
LIFT INCREASES AHEAD OF THIS SYSTEM AND WE COULD SEE SOME LIGHT
PCPN DEVELOPING WITH MODEL FORECAST SOUNDINGS THE POTENTIAL FOR
FREEZING DRIZZLE INITIALLY UNTIL LLVL TEMPS RISE. CONFIDENCE IS
NOT HIGH ENOUGH TO MENTION FREEZING PCPN THIS FAR OUT AND HAVE
WENT WITH SILENT POPS FOR NOW.
THE EXTENDED INIT REINTRODUCED POPS INTO THE SUNDAY TIME FRAME AS
THE SYSTEM MOVES THRU...WHICH FAVORS A LIQUID EVENT DURING THE
DAYTIME HOURS. THE FORECAST DRIES OUT SUNDAY NIGHT BEHIND THE
DEPARTING TROUGH AND REMAINS DRY THRU WEDNESDAY. A CLIPPER
SYSTEM/TROUGH MOVING THRU THE UPPER MIDWEST/GREAT LAKES REGION
WILL BACK IN SOME SLIGHTLY COOLER AIR INTO OUR NORTHEAST ZONES
HEADING INTO MONDAY. A DRY AND MILD AIRMASS NEXT WEEK WILL RESULT
IN ABOVE NORMAL TEMPS THRU WEDNESDAY WITH HIGHS AVERAGING IN THE
40S/50.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM CST WED DEC 3 2014
QUIET WEATHER WITH VFR CONDITIONS CURRENTLY FORECAST FOR THIS TAF
PERIOD. ANY CLOUDS THAT PASS THROUGH THE TERMINAL AREAS LOOKING TO
REMAIN IN THE UPPER LEVELS. NOT EXPECTING ANY SIGNIFICANT CHANGES
IN WINDS THROUGH THE PERIOD WITH LITTLE CHANGE IN THE
PATTERN...WITH WINDS REMAINING SOUTHERLY AND SPEEDS TOPPING OUT
AROUND 10 MPH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...FAY
AVIATION...ADP
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
322 PM MST THU DEC 4 2014
.SYNOPSIS...
WET WEATHER WILL CONTINUE INTO THIS EVENING FOR MUCH OF THE REGION
BEFORE SLOW CLEARING DEVELOPS OVERNIGHT. SNOW ACCUMULATIONS WILL BE
GENERALLY LIGHT AND CONFINED TO AREAS ABOVE 9000 FEET. HIGH PRESSURE
WILL RETURN TO THE AREA BRIEFLY ON FRIDAY. THE NEXT STORM SYSTEM WILL
MOVE IN SATURDAY WITH THICK CLOUD COVER AND SHOWERS. SNOW LEVELS WILL
BE LOWER WITH THE NEXT SYSTEM HOWEVER AMOUNTS WILL STILL BE LIGHT.
SLIGHTLY ACTIVE WEATHER IS EXPECTED THROUGH NEXT WEEK WITH AT LEAST
SOME CHANCES FOR SHOWERS...PARTICULARLY IN THE HIGHER TERRAIN.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH MUCH OF NEXT WEEK.
&&
.DISCUSSION...
LATEST RADAR LOOP THIS AFTERNOON SHOWING THE MOST WIDESPREAD PRECIP
ON SCOPE IN QUITE SOME TIME. THE AXIS OF THE UPPER WAVE PER SATELLITE
IMAGERY IS STILL POISED ALONG THE NM/AZ BORDER...AND MOVING QUICKLY
EAST. THE 18Z HRRR AND NAM AGREE PRECIP WILL SLOWLY TAPER OFF DURING
THE MID/LATE EVENING HOURS MOST AREAS...AND LINGER ALONG WEST SLOPES
OF THE NORTHERN HIGH TERRAIN. CURRENTLY SNOW LEVELS ARE IMPRESSIVELY
HIGH WITH TEMPS NEAR FREEZING STILL AROUND 11KFT. COLD ADVECTION
WITH THE APPROACHING TROUGH AXIS WILL LOWER SNOW LEVELS TO 9KFT THIS
EVENING THEN ABOUT 8KFT BY SUNRISE. THAT TREND IS ALSO REFLECTED IN
THE MIN TEMP FORECAST WHICH RUNS ABOUT 5-15F ABOVE NORMAL.
WEAK RIDGING NOTED BEHIND THIS SYSTEM ALREADY ON WATER VAPOR IMAGERY
WILL BE SHORT-LIVED AS THE NEXT STREAM OF THICK HIGH CLOUDS IS ON
THE MOVE OVER THE EASTERN PACIFIC. INCREASED CLOUD COVER AND POPS
SLIGHTLY FOR SATURDAY/SATURDAY NIGHT. QPF WITH THIS SYSTEM IS PROGGED
MUCH LOWER THAN THIS CURRENT SYSTEM AND THE SOURCE REGION OF MID/
UPPER LEVEL MOISTURE IS NOT SO MUCH SUBTROPICAL...BUT STILL WOULD
NOT BE SURPRISED FOR MODELS TO CONTINUE TRENDING DEEPER AND WETTER.
NONETHELESS...PRECIP MODE LOOKS MORE CONVECTIVE THAN STRATIFORM.
700MB COLD ADVECTION WILL BE SLIGHTLY BETTER AND THICKNESS VALUES
DECREASE BUT STILL SNOW LEVELS WILL BE PRETTY HIGH FOR DECEMBER.
LOCATIONS ABOVE 8KFT COULD SEE A FEW INCHES OF SNOW...WITH QPF ON
THE ORDER OF 0.10-0.20 FOR LOWER ELEVATIONS. ASSOCIATED PWAT VALES
FROM THE NAM AND GFS AT KABQ NEAR 0.50 INCHES.
ANOTHER BREAK IN THE ACTION IS ON TAP FOR SUNDAY HOWEVER IT STILL
LOOKS LIKE HIGH LEVEL MOISTURE WILL KEEP HIGH CLOUDS AROUND. SEVERAL
WEATHER DISTURBANCES ARE ADVERTISED THROUGH NEXT WEEK BUT TIMING AND
STRENGTH ARE IN QUESTION. THERE ARE AT LEAST SLIGHT CHANCES WITH
RETURN FLOW FROM THE CENTRAL MT CHAIN EASTWARD. THE GFS AND ECMWF
ARE STILL SHOWING A BIG STORM SYSTEM LATE NEXT WEEK.
GUYER
&&
.FIRE WEATHER...
WET WEATHER SYSTEM WILL EJECT EASTWARD TONIGHT LEAVING SEVERAL
INCHES OF SNOW ACCUMULATION MAINLY ABOVE 8000 FT IN THE NORTHERN
MOUNTAINS. MIN HUMIDITIES ON FRIDAY WILL FALL 14 TO 30 DEGREES AS A
WEAK RIDGE OF HIGH PRESSURE CROSSES FROM THE WEST. THERE WILL ALSO
BE WIDESPREAD POOR VENTILATION ON FRIDAY WEST OF THE EASTERN TIER OF
COUNTIES AS TEMPERATURES RISE A FEW TO 5 DEGREES IN MOST PLACES.
ANOTHER UPPER LEVEL TROUGH WILL CROSS FROM THE WEST WITH WIDESPREAD
PRECIPITATION SATURDAY AND SATURDAY NIGHT. AT THIS TIME
SOUTHERN...CENTRAL AND NORTHWEST AREAS LOOK FAVORED FOR WETTING
PRECIPITATION WITH SPOTTIER AND LIGHTER PRECIP ACROSS THE NORTHEAST.
IT SHOULD BE ANOTHER WARM SYSTEM WITH 700 MB TEMPERATURES ONLY
DROPPING TO BETWEEN 0 AND 2 DEGREES. THE NORTHERN MOUNTAINS SHOULD
ACCUMULATE A FEW TO SEVERAL INCHES OF SNOW ABOVE 9000 FT
AGAIN...WITH THE HIGHER AMOUNTS ON WEST FACING SLOPES. THERE WILL BE
VENTILATION IMPROVEMENT IN MOST PLACES SATURDAY...BUT POCKETS OF
POOR VENTILATION WILL PERSIST MAINLY ACROSS EAST CENTRAL AND
NORTHWEST AREAS. TEMPERATURES WILL TREND DOWNWARD AGAIN IN MOST
PLACES SATURDAY.
ANOTHER RIDGE OF HIGH PRESSURE WILL CROSS ALOFT SUNDAY BEFORE THE
FLOW TURNS ZONAL ON MONDAY. THIS WILL RESULT IN A TWO DAY WARMING
AND DRYING TREND IN MOST PLACES WITH WIDESPREAD POOR VENTILATION BOTH
DAYS. THERE SHOULD BE POCKETS OF FAIR TO GOOD VENTILATION EAST OF
THE CENTRAL MOUNTAINS.
MODELS ARE IN FAIR AGREEMENT ON A WEAKER UPPER LEVEL TROUGH CROSSING
TUESDAY BEFORE A RIDGE ON WEDNESDAY. TUESDAYS TROUGH COULD TRIGGER
A FEW LIGHT SHOWERS OVER THE MOUNTAINS AND SE AREAS. AFTER SOME
VENTILATION IMPROVEMENT WITHIN 50 MILES OF THE I-40 CORRIDOR
TUESDAY...WIDESPREAD POOR VENTILATION IS EXPECTED AGAIN ON
WEDNESDAY. HIGH TEMPERATURES WILL ALSO FALL A FEW DEGREES THEN REBOUND
WEDNESDAY.
44
&&
.AVIATION...
18Z TAF CYCLE
A WAVE OF PRECIPITATION WILL PASS NEWD OVER THE AREA TODAY WITH
MVFR AND IFR CONDITIONS IN LIGHT RAIN AND HIGH TERRAIN SNOW COMMON.
ABUNDANT MT OBSCURATION IS ALSO EXPECTED AREAWIDE. THE BEST FETCH
OF MOISTURE SHOULD PASS N AND W OF KROW...BUT EVEN THEY COULD
BRIEFLY EXPERIENCE SOME HIGH BASED SHOWERS THIS AFTN. THE SNOW
LEVEL SHOULD DROP FROM AROUND 9K FT ACROSS THE N AND 10K FT ACROSS
THE S TODAY TO AROUND 7500 FT THIS EVENING. THE WAVE OF PCPN IS
PROGGED TO EXIT W CENTRAL AND SW AREAS LATE THIS AFTN...CENTRAL
AREAS EARLY THIS EVENING AND E AREAS DURING THE MID TO LATE
EVENING. A SECONDARY BATCH OF SHOWERS ACROSS NW AND N CENTRAL
AREAS TODAY SHOULD LINGER WELL INTO THE EVENING. CEILINGS ARE
LIKELY TO RISE TO VFR THIS EVENING ACROSS CENTRAL AREAS. LOW
CLOUDS AND/OR PATCHY FOG SHOULD THEN DEVELOP ACROSS CENTRAL AND
WESTERN AREAS LATE TONIGHT INTO FRI MORNING.
44
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 34 51 33 53 / 40 5 5 20
DULCE........................... 29 50 24 52 / 70 5 5 30
CUBA............................ 32 50 28 49 / 70 5 5 30
GALLUP.......................... 33 52 31 54 / 30 5 5 30
EL MORRO........................ 31 50 29 50 / 30 5 5 30
GRANTS.......................... 31 52 26 52 / 30 0 5 20
QUEMADO......................... 34 51 35 51 / 30 0 0 30
GLENWOOD........................ 36 63 36 61 / 20 0 0 20
CHAMA........................... 26 48 23 48 / 80 10 5 30
LOS ALAMOS...................... 34 47 35 46 / 60 0 5 20
PECOS........................... 34 50 32 45 / 60 0 5 20
CERRO/QUESTA.................... 25 46 23 46 / 70 5 5 20
RED RIVER....................... 25 40 20 40 / 100 10 5 20
ANGEL FIRE...................... 23 45 21 44 / 80 10 5 20
TAOS............................ 29 48 26 47 / 80 0 5 20
MORA............................ 33 51 32 46 / 60 0 5 20
ESPANOLA........................ 33 52 30 52 / 60 0 5 10
SANTA FE........................ 34 47 34 47 / 70 0 5 20
SANTA FE AIRPORT................ 33 52 29 51 / 60 0 5 20
ALBUQUERQUE FOOTHILLS........... 36 52 39 52 / 60 0 5 20
ALBUQUERQUE HEIGHTS............. 39 55 36 55 / 60 0 5 10
ALBUQUERQUE VALLEY.............. 36 56 34 56 / 50 0 5 10
ALBUQUERQUE WEST MESA........... 37 56 34 56 / 60 0 5 10
LOS LUNAS....................... 36 56 30 55 / 50 0 0 10
RIO RANCHO...................... 38 55 36 55 / 60 0 5 20
SOCORRO......................... 37 59 34 58 / 30 0 0 10
SANDIA PARK/CEDAR CREST......... 33 50 33 50 / 60 0 5 30
TIJERAS......................... 34 52 35 52 / 60 0 5 20
MORIARTY/ESTANCIA............... 30 54 25 51 / 50 0 5 20
CLINES CORNERS.................. 33 53 30 47 / 50 0 5 20
GRAN QUIVIRA.................... 36 54 34 52 / 40 0 0 20
CARRIZOZO....................... 37 58 34 56 / 30 0 0 10
RUIDOSO......................... 36 59 32 55 / 20 0 0 20
CAPULIN......................... 35 51 30 47 / 70 0 5 5
RATON........................... 32 54 28 48 / 60 0 5 5
SPRINGER........................ 32 56 29 49 / 60 0 5 10
LAS VEGAS....................... 33 55 28 47 / 50 0 5 10
CLAYTON......................... 39 59 32 53 / 60 0 0 0
ROY............................. 36 58 31 49 / 60 0 0 5
CONCHAS......................... 40 60 38 53 / 40 0 5 5
SANTA ROSA...................... 41 61 37 53 / 30 0 0 10
TUCUMCARI....................... 42 63 35 56 / 30 0 0 5
CLOVIS.......................... 41 65 36 55 / 20 0 0 5
PORTALES........................ 41 65 36 57 / 20 0 5 5
FORT SUMNER..................... 40 65 38 55 / 20 0 0 5
ROSWELL......................... 39 68 36 57 / 10 0 0 10
PICACHO......................... 42 65 38 53 / 10 0 5 10
ELK............................. 41 61 37 52 / 10 0 5 10
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR THE
FOLLOWING ZONES...NMZ513-514.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1010 PM EST FRI DEC 5 2014
.SYNOPSIS...A COLD FRONT WILL APPROACH CENTRAL NORTH CAROLINA FROM
THE WEST TONIGHT AND SATURDAY...AND CROSS THE REGION SATURDAY NIGHT.
HIGH PRESSURE WILL BUILD INTO THE CAROLINAS ON SUNDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 1010 PM FRIDAY...
TWO MAIN FORECAST PROBLEMS FOR THIS EVENING...THE FIRST...WILL THERE
BE FOG ACROSS THE SOUTHERN COUNTIES...AND SECOND...THE ARRIVAL TIME
OF THE PRECIPITATION ON SATURDAY. ADDRESSING THE FOG...MUCH OF
CENTRAL NC REMAINS ENSHROUDED IN CLOUD COVER WITH SOME CLEARING
ACROSS THE SOUTHWEST. VISIBILITIES FOR THE MOST PART HAVE REMAINED
ABOVE TEN MILES AS DEWPOINT DEPRESSIONS HAVE ALSO REMAINED PLUS OR
MINUS FIVE DEGREES. AS THE AREA OF CLEARING OVER THE SOUTHWEST MOVES
EASTWARD...THERE COULD BE A FEW HOURS BEFORE SUNRISE WHEN THE
TEMPERATURE DROPS TO THE DEWPOINT AND SOME PATCHY DENSE FOG WILL BE
POSSIBLE. FOR THE MOST PART HOWEVER...LOW STRATUS WILL BE THE MORE
LIKELY SCENARIO WITH SEVERAL SITES IN THE SANDHILLS ALREADY SHOWING
MVFR CEILINGS.
THE MAIN SYSTEM THAT IS EXPECTED TO GENERATE PRECIPITATION OVER THE
AREA ON SATURDAY REMAINS OVER THE TENNESSEE VALLEY AND SHORT TERM
MODELS ARE PROGGING THE ARRIVAL OF THE PRECIP TO BE A LITTLE BIT
LATER THAN PREVIOUSLY ANTICIPATED. HAVE CUT BACK ON POPS SATURDAY
MORNING AND BLEND INTO HIGHER POPS STILL EXPECTED FOR SATURDAY
AFTERNOON/EVENING. THE LATEST RAP MODEL ACTUALLY SHOWS PRECIP IN OUR
CWA BEGINNING FIRST IN THE EAST IN ASSOCIATION WITH A SMALLER WAVE
MOVING IN OFF OF THE SW ATLANTIC AFTER 9Z AND THEN PRECIPITATION
ASSOCIATED WITH THE WESTERN SYSTEM APPROACHING THE NW PIEDMONT AFTER
12Z SATURDAY.
LOWS TONIGHT WILL RANGE FROM THE LOW TO MIDDLE 40S.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 310 PM FRIDAY...
SATURDAY... S/W AND ASSOCIATED SURFACE FRONT WILL BE TO OUR WEST AT
18Z...CROSSING OUR REGION SATURDAY EVENING. LOW-MID LEVEL SOUTH-
SOUTHWEST FLOW WILL ADVECT ABUNDANT MOISTURE INTO OUR REGION.
MEANWHILE SUFFICIENT LIFT WILL BE PROVIDED BY: A.) DIVERGENCE ALOFT
DUE TO THE CAROLINAS BEING IN THE FAVORABLE POSITION OF TWO JETS
(ONE EXITING NEW ENGLAND WHILE THE OTHER DIVING SEWD ACROSS THE TN
VALLEY); B.) 40-60M/12 HOUR MID LEVEL HEIGHT FALLS; C.) AND LATER IN
THE DAY, CONVERGENCE ALONG THE SFC-850MB COLD FRONT. THIS FAVORABLE
ATMOSPHERE SHOULD CAUSE NUMEROUS SHOWERS TO OVERSPREAD THE PIEDMONT
AND THE NORTHERN COASTAL PLAIN DURING THE MORNING HOURS...AND INTO
THE SANDHILLS AND THE REMAINDER OF THE COASTAL PLAIN IN THE
AFTERNOON.
POTENTIAL EXISTS FOR A FEW THUNDERSTORMS TO OCCUR SATURDAY AFTERNOON-
EARLY EVENING AS MID LEVEL LAPSE RATES REACH AS HIGH AS 6.5-7 DEG
C/KM AND BULK SHEAR ACHIEVES FAVORABLE VALUES 30-35KTS. LOW LEVEL
INSTABILITY LACKING AS SBCAPE IS AOB 200 J/KG WHILE MUCAPE NO HIGHER
THAN 200-250 J/KG LATE SATURDAY-SATURDAY EVENING. THUS...EXPECT
CONVECTION TO BE ELEVATED WITH LITTLE IF ANY CHANCE OF STORMS
BECOMING STRONG/SEVERE.
HIGH TEMPS SATURDAY STILL A CHALLENGE...DEPENDENT UPON EXTENT OF
RAIN SHOWERS. STILL FAVOR MAX TEMPS SLIGHTLY COOLER THAN GUIDANCE
ACROSS THE PIEDMONT AS A SHORT-LIVED IN-SITU OR HYBRID CAD MAY SET
UP EARLY SATURDAY. CONVERSELY...IF SHOWERS HOLD OFF LONG
ENOUGH...TEMPS IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN MAY WARM
INTO THE MID-UPPER 60S.
SATURDAY NIGHT... SURFACE COLD FRONT PROGRESSES EAST ACROSS CENTRAL
NC IN THE EVENING...EXITING OUR COASTAL PLAIN COUNTIES AROUND OR
SHORTLY AFTER MIDNIGHT. THE 850-700MB TROUGHS FOLLOW SHORTLY
AFTERWARDS. LOW-MID LEVEL N-NW FLOW IN THE WAKE OF THE TROUGH
PASSAGE WILL AID TO DIMINISH SHOWER COVERAGE IN THE WEST SATURDAY
EVENING...AND OVERNIGHT IN THE EAST. PARTIAL CLEARING SHOULD
INITIATE IN THE NORTH-NW AFTER MIDNIGHT. SURFACE FRONTAL PASSAGE
WILL BE NOTED BY WINDS VEERING TO THE N-NW AND INITIALLY GUSTING
AROUND 20KTS. MIN TEMPS LOW-MID 40S NORTH TO UPPER 40S SE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 220 PM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE LATEST RUN OF THE ECMWF AGREES WELL
WITH THE GFS IN REGARD TO THE LOW AND ITS ASSOCIATED COLD FRONT
MOVING OFF THE CAROLINA COAST PRIOR TO 12Z SUNDAY. AS SUCH...HAVE A
DRY FORECAST FOR SUNDAY AND SUNDAY NIGHT. THE BIG QUESTION WILL BE
HOW QUICKLY THE SKIES CLEAR AND HOW THAT WILL AFFECT TEMPERATURES.
FOR NOW...EXPECT HIGHS IN THE UPPER 40S NW TO 723MID 50S SOUTH AND
EAST...ALTHOUGH IF SKIES CLEAR QUICKER/SLOWER THAT COULD CHANGE BY A
COUPLE/FEW DEGREES. LOWS GENERALLY IN LOW 30S NW TO UPPER 30S SE.
MONDAY THROUGH FRIDAY: CONFIDENCE IS STILL NOT TERRIBLY HIGH FOR
NEXT WEEK...HOWEVER IT HAS INCREASED SOME OVERALL AS THE MODELS
APPEAR TO BE SLOWLY COMING INTO BETTER AGREEMENT. THE ECMWF SEEMS TO
BE TRENDING MORE TOWARD THE GFS WITH THE UPPER LEVEL LOW THAT MOVES
THROUGH THE GREAT LAKES AND NORTHEAST U.S. TOWARD THE END OF NEXT
WEEK. ALTHOUGH IT CONTINUES TO BE DEEPER WITH THE UPPER LEVEL TROUGH
AND STILL TRIES TO GENERATE A BIT OF PRECIPITATION OVER PORTIONS OF
THE CAROLINAS EARLY IN THE WEEK. THERE IS STILL SOME UNCERTAINTY
WITH RESPECT TO THAT LOW...AND GIVEN THE MODEL TREND...EXPECT IT TO
STAY MAINLY WELL NORTH OF THE REGION AND BE OF LITTLE CONSEQUENCE IN
THE PRECIPITATION DEPARTMENT FOR CENTRAL NC AT THIS TIME. WITH THAT
HYPOTHESIS IN MIND...EXPECT NEXT WEEK TO BE GENERALLY DRY...WITH
HIGH PRESSURE DOMINATING AT THE SURFACE. THE FIRST HIGH WILL RIDGE
IN FROM THE NORTHEAST AND RESULT IN A WEDGE OF A COLD AIR OVER THE
AREA. A REINFORCING SHOT OF COLD AIR WILL PUSH THROUGH THE AREA
TUESDAY NIGHT INTO WEDNESDAY...WITH ANOTHER AREA OF HIGH PRESSURE
SUBSEQUENTLY BUILDING IN THROUGH THE END OF THE WEEK. HIGHS ON
MONDAY WILL BE THE COOLEST OF THE PERIOD...MID 40S NW TO LOW 50S SE.
HIGHS WILL CONTINUE TO BE A LITTLE BIT OF A RO723LLER COASTER
THROUGH THE REST OF THE WEEK...WITH LOW TO MID 50S EXPECTED ON
TUESDAY AND FRIDAY...BUT UPPER 40S TO LOW 50S WEDNESDAY AND
THURSDAY. LOWS WILL GENERALLY DECREASE FROM THE LOW 30S NW TO UPPER
30S SE MONDAY NIGHT TO UPPER 20S ACROSS THE AREA BY WED AND THU
NIGHTS...MODERATING AGAIN INTO THE LOW 30S FRI NIGHT.
&&
.AVIATION /00Z FRIDAY THROUGH WEDNESDAY/...
AS OF 720 PM FRIDAY...
24 HOUR TAF PERIOD: VFR CONDITIONS WILL CONTINUE THIS EVENING AT
KRDU/KFAY/KRWI... WHILE MVFR CIGS WILL CONTINUE TO SLOWLY LIFT TO
VFR AT KGSO/KINT THIS EVENING. EXPECT VFR CONDITIONS AT ALL CENTRAL
NC TAF SITES BY AROUND 03Z OR SO. HOWEVER... VFR CONDITIONS WILL BE
SHORT LIVED. A COLD FRONT WILL APPROACH THE REGION FROM THE WEST
TONIGHT AND CROSS CENTRAL NC SATURDAY AFTERNOON INTO THE EVENING.
MVFR TO IFR CIGS WILL DEVELOP IN ADVANCE OF THE FRONT ON SATURDAY
MORNING...WITH EVEN SOME LIFR CONDITIONS POSSIBLE AS A BAND OF
SHOWERS AND POSSIBLY EVEN SOME EMBEDDED THUNDERSTORMS CROSS THE AREA
SATURDAY MORNING INTO SATURDAY EVENING.
THE SHOWERS WILL DIMINISH IN COVERAGE FROM THE SW...BEGINNING
SATURDAY EVENING IN THE SOUTHERN PIEDMONT...REACHING THE NORTHERN
COASTAL PLAIN AFTER 06Z SUNDAY. MVFR/IFR CEILINGS WILL PERSIST
THROUGH SATURDAY EVENING THOUGH... WITH CEILINGS LIFTING LATE
SATURDAY NIGHT INTO SUNDAY MORNING.
WHILE VFR CONDITIONS ARE EXPECTED SUNDAY AS HIGH PRESSURE BUILDS
INTO THE REGION FROM NEW ENGLAND...BRISK N-NE WINDS WILL GUSTS CLOSE
TO 25KTS.
MVFR CEILINGS WILL BE POSSIBLE MONDAY INTO TUESDAY WITH IMPROVING
CONDITIONS ANTICIPATED BY WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...ELLIS
SHORT TERM...WSS
LONG TERM...KC
AVIATION...BSD/WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1007 PM EST FRI DEC 5 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A COASTAL TROUGH WILL
LIFT NORTH AS A WARM FRONT ON SATURDAY...AHEAD OF A COLD FRONT
WHICH WILL MOVE ACROSS THE AREA SATURDAY NIGHT. THIS COLD FRONT
WILL BRING A PERIOD OF SHOWERS WITH AN ISOLATED THUNDERSTORM
POSSIBLE. A STRONG WEDGE OF HIGH PRESSURE WILL BUILD SOUTH SUNDAY
AND MONDAY...BRINGING GUSTY NORTH WINDS AND MUCH COOLER
TEMPERATURES. CANADIAN HIGH PRESSURE NEXT WEEK WILL MAINTAIN
SEASONABLY COOL TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM FRIDAY...A COASTAL TROUGH DEVELOPING ACROSS THE
WATERS IS EXPECTED TO DRIFT TO THE COAST OVERNIGHT. CONVERGENT
FLOW IN ASSOCIATION WITH THE TROUGH SHOULD HELP TO BRING SOME OF
THE OFFSHORE SHOWERS ONTO THE COAST LATE TONIGHT. THE HIGH
RESOLUTION HRRR IS MOST BULLISH WITH THIS SCENARIO...PRIMARILY FOR
THE CAPE FEAR AREA LATE TONIGHT. OTHERWISE AS CHILLY HIGH PRESSURE
DRIFTS OFFSHORE AND A TROUGH APPROACHES FROM THE W...A DEEP S TO
SW FLOW WILL ENVELOP THE EASTERN CAROLINAS. THE COLUMN WILL
CONTINUE TO SLOWLY MOISTEN...PRECIPITABLE WATER VALUES WILL REACH
NEAR 1.25 INCHES BY SUNRISE. SHOWERS ASSOCIATED WITH THE
AFOREMENTIONED TROUGH WILL REMAIN W OF THE FORECAST AREA INTO
EARLY SAT MORNING. A WARM AIR ADVECTION PATTERN AND INCREASING
MOISTURE CONTENT WILL BRING A GOOD DEAL OF CLOUDINESS THROUGH THE
NIGHT. THE CLOUDS SHOULD HELP TO FLATTEN THE TEMP CURVE WITH LOWS
MAINLY IN THE MID AND UPPER 40S INLAND AND LOWER 50S AT THE
COAST...SO LITTLE TEMP MOVEMENT THROUGH THE NIGHT. ALTHOUGH MODELS
ARE INDICATING A PRONOUNCED NEAR SURFACE INVERSION DEVELOPING...THEY
ARE RELUCTANT TO SATURATE THE LEVEL CLOSEST TO THE GROUND. ALSO...
USING A UPS FOG METHODOLOGY GRIDDED SMART TOOL...FOG IS EXPECTED TO
DEVELOP W OF THE FORECAST AREA AND ADVECT NORTHWARD WITH TIME.
THUS...STILL LOOKS AS THOUGH SIGNIFICANT FOG WILL HAVE A DIFFICULT
TIME DEVELOPING AND WILL FAVOR LOW STRATUS OVER FOG AT THIS
TIME...BUT CONTINUE TO MONITOR NEAR TERM TRENDS. THIS LOW STRATUS
MAY PRODUCE SOME SPOTTY DRIZZLE FROM TIME TO TIME AND HAVE ADDED
PATCHY DRIZZLE TO THE FORECAST TOWARD MORNING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...COASTAL TROUGH LIFTING NORTH AS A WARM
FRONT SATURDAY MORNING WILL CREATE A WARM DAY...ESPECIALLY ALONG
THE COAST...BUT RAIN CHANCES WILL INCREASE RAPIDLY LATE IN THE
DAY. AS THE COASTAL TROUGH LIFTS NORTH EARLY...WAA WILL FOLLOW
THROUGH THE AFTN...WITH 850MB TEMPS CLIMBING TO AROUND 10C BY
SATURDAY AFTN. AS THIS OCCURS HOWEVER...CLOUD COVER WILL BE ON THE
INCREASE THANKS TO MOIST ADVECTION AND PVA AHEAD OF A SHORTWAVE
WHICH WILL MOVE JUST NORTH OF THE AREA SATURDAY NIGHT. BENEATH
THIS SHORTWAVE...A SURFACE LOW WILL PUSH EAST NEAR THE NC/VA
BORDER...DRAGGING A COLD FRONT ACROSS THE CWA SATURDAY NIGHT. AS
PWATS RISE TO ABOUT 1.25 INCHES AND MID-LEVEL LAPSE RATES CLIMB
TOWARDS 7C/KM...SCATTERED SHOWERS WITH ISOLATED TSTMS ARE
EXPECTED. INSTABILITY REMAINS MINIMAL...BUT CANNOT RULE OUT A FEW
LIGHTNING STRIKES...AND THIS IS ECHOED BY THE GENERAL RISK
ENCOMPASSING THE ILM CWA IN THE SWODY2. TOTAL QPF WILL NOT BE VERY
HIGH...BUT BRIEF PERIODS OF HEAVY RAIN IS POSSIBLE WITHIN A FEW
HOURS EITHER SIDE OF SATURDAY EVENING. COOL ADVECTION BEGINS IN
EARNEST BEHIND THE COLD FRONT LATE SATURDAY NIGHT...SO TEMPS WHICH
WILL RISE TOWARDS 70 ALONG THE COAST SATURDAY AFTN...MID 60S WELL
INLAND...WILL DROP RAPIDLY INTO THE LOW 40S WELL NW...TO AROUND 50
AT THE COAST...BY SUNDAY MORNING.
A QUIETER BUT MUCH COOLER DAY ON SUNDAY AS A STRONG WEDGE OF HIGH
PRESSURE DEVELOPS BEHIND THE COLD FRONT FROM SATURDAY NIGHT. WITH
LOW-LEVEL MOISTURE PROGGED TO REMAIN HIGH BENEATH THE WEDGE...PARTLY
TO MOSTLY CLOUDY CONDITIONS WILL PERSIST MUCH OF SUNDAY. THIS
COMBINED WITH COOL ADVECTION WILL LIMIT WARMING...AND HIGHS MAY BE
REACHED VERY EARLY IN THE DAY...WITH LITTLE DIURNAL RANGE. EXPECT
HIGHS ONLY IN THE LOW 50S IN THE FAR NORTH...TO MID 50S IN THE
SOUTH. SOME CLEARING WILL OCCUR VERY LATE...AND CONTINUED CAA WILL
HELP MINS FALL INTO THE UPPER 30S SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE MID LEVEL PATTERN WILL BE QUITE
PROGRESSIVE THROUGH THE PERIOD WITH THE AREA REMAINING VOID OF ANY
SIGNIFICANT PRECIPITATION. INITIALLY A LINGERING LOW PRESSURE
SYSTEM OFF THE SOUTHEAST COAST MAY PROVIDE A FEW SHOWERS...MORESO
ALONG THE COAST MONDAY BEFORE A COLD FRONT...ASSOCIATED WITH
FAIRLY STRONG SHORTWAVE MOVING THROUGH THE MIDWEST SWEEPS THE AREA
CLEAN. BEYOND THIS A WEAKENING CYCLONIC FLOW ALOFT WILL PREVAIL
ACROSS THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BUILD DOWN
FROM THE UPPER MIDWEST TO ESSENTIALLY OVER THE AREA BY FRIDAY THUS
A DRY FORECAST. TEMPERATURES TRENDS LOOK A LITTLE BELOW
CLIMATOLOGY WITH HIGHS MOSTLY IN THE 50S AND LOWS IN THE LOWER TO
MIDDLE 30S
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE ON THE BACK END OF THE FORECAST
PERIOD WITH RESPECT TO CEILINGS AND THE TIMING OF PRECIP. LOOKS LIKE
THERE COULD BE TWO BATCHES OF RAIN/SHOWERS: THE FIRST AROUND SUNRISE
WITH A COASTAL TROUGH...THEN ANOTHER ROUND IN THE LATE AFTERNOON
AHEAD OF A COLD FRONT. MODELS ARE IN REASONABLE AGREEMENT
INTRODUCING IFR STRATUS/FOG AROUND DAYBREAK IF NOT BEFORE...AND THIS
MAKES SENSE GIVEN THE WEAK WARM AIR ADVECTION. THE HRRR MODEL THINKS
THAT ILM STANDS THE BEST CHANCE FOR MORNING PRECIP...BUT THE MYRTLES
COULD ALSO GET INTO THE ACT. THINK THE MORNING PRECIP WILL GIVE WAY
TO MVFR CEILINGS AND SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT WHICH
WILL ARRIVE AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...PERIODS OF MVFR/IFR CIGS ARE LIKELY THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK. GUSTY NORTH WINDS SUN/MON BEHIND
THE COLD FRONT. BECOMING VFR DURING TUE. VFR WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM FRIDAY...A COASTAL TROUGH WILL BE IN CLOSE PROXIMITY
THROUGH TONIGHT AND LIKELY JUST ABOUT ON THE IMMEDIATE COAST AROUND
DAYBREAK SAT. NE WINDS ARE EXPECTED TO SHIFT TO THE E OR ESE
OVERNIGHT WITH ITS PASSAGE. WIND SPEEDS WILL BE UP TO 10 TO 15 KT
LATE THIS EVE...DECREASING TO 10 KT OR LESS OVERNIGHT. SEAS WILL BE
3 TO 4 FT WITH A 8 TO 10 SECOND EASTERLY SWELL PRESENT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...QUIET MARINE CONDITIONS TO START THE
PERIOD...BUT RAPID DETERIORATION IS EXPECTED ON SUNDAY. WEAK
COASTAL TROUGH WILL LIFT NORTH ON SATURDAY...WITH WINDS TURNING
FROM SE TO SW THROUGH THE AFTN...BUT AT LIGHT SPEEDS. LOW PRESSURE
MOVING NORTH OF THE AREA WILL DRAG A COLD FRONT ACROSS THE WATERS
SATURDAY NIGHT...AND WINDS WILL TURN ABRUPTLY TO THE NORTH AT
15-20 KTS BY SUNDAY MORNING. SEAS ON SATURDAY WILL BE GENERALLY
2-4 FT REGARDLESS OF WIND DIRECTION...BUT WILL BEGIN TO RISE LATE
BEHIND THE COLD FRONT.
GALE WATCH HAS BEEN HOISTED FOR THE NC WATERS BEGINNING SUNDAY
MORNING...AND THERE IS PRETTY HIGH CONFIDENCE IN A GALE OCCURRING
SUNDAY AS A STRONG WEDGE OF HIGH PRESSURE BUILDS DOWN THE COAST.
THIS WILL CAUSE A TIGHT GRADIENT OVER THE WATERS...AND WIND WILL
BECOME NE AT 20-30 KTS ON SUNDAY...WITH FREQUENT GUSTS TO 35 KTS OR
MORE EXPECTED ACROSS THE NC WATERS. THERE IS LOWER CONFIDENCE IN
GALE-FORCE WINDS ACROSS SC WATERS...BUT AT LEAST A STRONG SMALL
CRAFT ADVISORY IS EXPECTED. THESE STRONG WINDS WILL ALSO PUSH SEAS
UP TO TO 5-9 FT ON SUNDAY...WITH THE EXCEPTION BEING THE WAVE
SHADOWED REGION SW OF BRUNSWICK COUNTY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...NEXT WEEK WILL NOT BE THE BEST OF TIMES FOR
THE MARINE COMMUNITY AS BLUSTERY CONDITIONS AND ELEVATED SEAS WILL
CONTINUE. FOR MONDAY A POTENT NORTHERLY FLOW WILL CONTINUE AS LOW
PRESSURE MOVES WELL OFF TO THE NORTHEAST AND MASSIVE HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. EXPECT WINDS OF 20-25 KNOTS...POSSIBLY
HIGHER WITH CERTAIN SMALL CRAFT CONDITIONS AND POSSIBLY GALES. THE
WINDS DO DIMINISH THROUGHOUT THE DAY TO SETTLE AT 10-15 KNOTS BY
TUESDAY MORNING. HERE THE WINDS WILL REMAIN THROUGH WEDNESDAY. SEAS
WILL BE HIGHEST MONDAY WITH 3-6 FEET DROPPING TO 2-5 FEET TUESDAY
AND WEDNESDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 700 PM WEDNESDAY...THE FULL MOON IS ON SATURDAY. WE EXPECT
ELEVATED WATER LEVELS DURING THE TIME OF HIGH TIDE THROUGH THE
WEEKEND. THE MORNING HIGH TIDE WILL BE HIGHEST AND THIS IS WHEN WE
EXPECT THE TIDE TO COME UP WELL ONTO THE BEACH. STRONG NNE WINDS
SUNDAY AND SUNDAY NIGHT WILL HELP TO ENHANCE THE ASTRONOMICAL
EFFECTS. THE LOWER CAPE FEAR RIVER WILL ALSO EXPERIENCE HIGHER THAN
PREDICTED WATER LEVELS AND MAY REACH COASTAL FLOOD ADVISORY CRITERIA
DURING THE MORNING HIGH TIDE THROUGH THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR AMZ250-252.
&&
$$
NEAR TERM...RJD
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...DL
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
749 PM EST FRI DEC 5 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A COASTAL TROUGH WILL
LIFT NORTH AS A WARM FRONT ON SATURDAY...AHEAD OF A COLD FRONT
WHICH WILL MOVE ACROSS THE AREA SATURDAY NIGHT. THIS COLD FRONT
WILL BRING A PERIOD OF SHOWERS WITH AN ISOLATED THUNDERSTORM
POSSIBLE. A STRONG WEDGE OF HIGH PRESSURE WILL BUILD SOUTH SUNDAY
AND MONDAY...BRINGING GUSTY NORTH WINDS AND MUCH COOLER
TEMPERATURES. CANADIAN HIGH PRESSURE NEXT WEEK WILL MAINTAIN
SEASONABLY COOL TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 PM FRIDAY...A COASTAL TROUGH DEVELOPING ACROSS THE
WATERS IS EXPECTED TO DRIFT TO THE COAST OVERNIGHT. CONVERGENT
FLOW IN ASSOCIATION WITH THE TROUGH SHOULD HELP TO BRING SOME OF
THE OFFSHORE SHOWERS ONTO THE COAST LATE TONIGHT. THE HIGH
RESOLUTION HRRR IS MOST BULLISH WITH THIS SCENARIO...PRIMARILY FOR
THE CAPE FEAR AREA LATE TONIGHT. OTHERWISE AS CHILLY HIGH PRESSURE
DRIFTS OFFSHORE AND A TROUGH APPROACHES FROM THE W...A DEEP S TO
SW FLOW WILL ENVELOP THE EASTERN CAROLINAS. THE COLUMN WILL
CONTINUE TO SLOWLY MOISTEN...PRECIPITABLE WATER VALUES WILL REACH
NEAR 1.25 INCHES BY SUNRISE. SHOWERS ASSOCIATED WITH THE
AFOREMENTIONED TROUGH WILL REMAIN W OF THE FORECAST AREA INTO
EARLY SAT MORNING. A WARM AIR ADVECTION PATTERN AND INCREASING
MOISTURE CONTENT WILL BRING A GOOD DEAL OF CLOUDINESS THROUGH THE
NIGHT. THE CLOUDS SHOULD HELP TO FLATTEN THE TEMP CURVE WITH LOWS
MAINLY IN THE MID AND UPPER 40S INLAND AND LOWER 50S AT THE COAST.
ALTHOUGH MODELS ARE INDICATING A PRONOUNCED NEAR SURFACE INVERSION
DEVELOPING...THEY ARE RELUCTANT TO SATURATE THE LEVEL CLOSEST TO
THE GROUND. THUS...SIGNIFICANT FOG MAY HAVE A DIFFICULT TIME
DEVELOPING AND WILL FAVOR LOW STRATUS OVER FOG AT THIS TIME...BUT
CONTINUE TO MONITOR NEAR TERM TRENDS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...COASTAL TROUGH LIFTING NORTH AS A WARM
FRONT SATURDAY MORNING WILL CREATE A WARM DAY...ESPECIALLY ALONG
THE COAST...BUT RAIN CHANCES WILL INCREASE RAPIDLY LATE IN THE
DAY. AS THE COASTAL TROUGH LIFTS NORTH EARLY...WAA WILL FOLLOW
THROUGH THE AFTN...WITH 850MB TEMPS CLIMBING TO AROUND 10C BY
SATURDAY AFTN. AS THIS OCCURS HOWEVER...CLOUD COVER WILL BE ON THE
INCREASE THANKS TO MOIST ADVECTION AND PVA AHEAD OF A SHORTWAVE
WHICH WILL MOVE JUST NORTH OF THE AREA SATURDAY NIGHT. BENEATH
THIS SHORTWAVE...A SURFACE LOW WILL PUSH EAST NEAR THE NC/VA
BORDER...DRAGGING A COLD FRONT ACROSS THE CWA SATURDAY NIGHT. AS
PWATS RISE TO ABOUT 1.25 INCHES AND MID-LEVEL LAPSE RATES CLIMB
TOWARDS 7C/KM...SCATTERED SHOWERS WITH ISOLATED TSTMS ARE
EXPECTED. INSTABILITY REMAINS MINIMAL...BUT CANNOT RULE OUT A FEW
LIGHTNING STRIKES...AND THIS IS ECHOED BY THE GENERAL RISK
ENCOMPASSING THE ILM CWA IN THE SWODY2. TOTAL QPF WILL NOT BE VERY
HIGH...BUT BRIEF PERIODS OF HEAVY RAIN IS POSSIBLE WITHIN A FEW
HOURS EITHER SIDE OF SATURDAY EVENING. COOL ADVECTION BEGINS IN
EARNEST BEHIND THE COLD FRONT LATE SATURDAY NIGHT...SO TEMPS WHICH
WILL RISE TOWARDS 70 ALONG THE COAST SATURDAY AFTN...MID 60S WELL
INLAND...WILL DROP RAPIDLY INTO THE LOW 40S WELL NW...TO AROUND 50
AT THE COAST...BY SUNDAY MORNING.
A QUIETER BUT MUCH COOLER DAY ON SUNDAY AS A STRONG WEDGE OF HIGH
PRESSURE DEVELOPS BEHIND THE COLD FRONT FROM SATURDAY NIGHT. WITH
LOW-LEVEL MOISTURE PROGGED TO REMAIN HIGH BENEATH THE WEDGE...PARTLY
TO MOSTLY CLOUDY CONDITIONS WILL PERSIST MUCH OF SUNDAY. THIS
COMBINED WITH COOL ADVECTION WILL LIMIT WARMING...AND HIGHS MAY BE
REACHED VERY EARLY IN THE DAY...WITH LITTLE DIURNAL RANGE. EXPECT
HIGHS ONLY IN THE LOW 50S IN THE FAR NORTH...TO MID 50S IN THE
SOUTH. SOME CLEARING WILL OCCUR VERY LATE...AND CONTINUED CAA WILL
HELP MINS FALL INTO THE UPPER 30S SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE MID LEVEL PATTERN WILL BE QUITE
PROGRESSIVE THROUGH THE PERIOD WITH THE AREA REMAINING VOID OF ANY
SIGNIFICANT PRECIPITATION. INITIALLY A LINGERING LOW PRESSURE
SYSTEM OFF THE SOUTHEAST COAST MAY PROVIDE A FEW SHOWERS...MORESO
ALONG THE COAST MONDAY BEFORE A COLD FRONT...ASSOCIATED WITH
FAIRLY STRONG SHORTWAVE MOVING THROUGH THE MIDWEST SWEEPS THE AREA
CLEAN. BEYOND THIS A WEAKENING CYCLONIC FLOW ALOFT WILL PREVAIL
ACROSS THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BUILD DOWN
FROM THE UPPER MIDWEST TO ESSENTIALLY OVER THE AREA BY FRIDAY THUS
A DRY FORECAST. TEMPERATURES TRENDS LOOK A LITTLE BELOW
CLIMATOLOGY WITH HIGHS MOSTLY IN THE 50S AND LOWS IN THE LOWER TO
MIDDLE 30S
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE ON THE BACK END OF THE FORECAST
PERIOD WITH RESPECT TO CEILINGS AND THE TIMING OF PRECIP. LOOKS LIKE
THERE COULD BE TWO BATCHES OF RAIN/SHOWERS: THE FIRST AROUND SUNRISE
WITH A COASTAL TROUGH...THEN ANOTHER ROUND IN THE LATE AFTERNOON
AHEAD OF A COLD FRONT. MODELS ARE IN REASONABLE AGREEMENT
INTRODUCING IFR STRATUS/FOG AROUND DAYBREAK IF NOT BEFORE...AND THIS
MAKES SENSE GIVEN THE WEAK WARM AIR ADVECTION. THE HRRR MODEL THINKS
THAT ILM STANDS THE BEST CHANCE FOR MORNING PRECIP...BUT THE MYRTLES
COULD ALSO GET INTO THE ACT. THINK THE MORNING PRECIP WILL GIVE WAY
TO MVFR CEILINGS AND SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT WHICH
WILL ARRIVE AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...PERIODS OF MVFR/IFR CIGS ARE LIKELY THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK. GUSTY NORTH WINDS SUN/MON BEHIND
THE COLD FRONT. BECOMING VFR DURING TUE. VFR WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 PM FRIDAY...A COASTAL TROUGH WILL BE IN CLOSE PROXIMITY
THROUGH TONIGHT AND LIKELY JUST ABOUT ON THE IMMEDIATE COAST
AROUND DAYBREAK SAT. NE WINDS ARE EXPECTED TO SHIFT TO THE E AND
SE OVERNIGHT WITH ITS PASSAGE. WIND SPEEDS WILL BE UP TO 10 TO 15
KT THIS EVE...DECREASING TO 10 KT OR LESS OVERNIGHT. SEAS WILL BE
3 TO 5 FT WITH A 8 TO 10 SECOND EASTERLY SWELL PRESENT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...QUIET MARINE CONDITIONS TO START THE
PERIOD...BUT RAPID DETERIORATION IS EXPECTED ON SUNDAY. WEAK
COASTAL TROUGH WILL LIFT NORTH ON SATURDAY...WITH WINDS TURNING
FROM SE TO SW THROUGH THE AFTN...BUT AT LIGHT SPEEDS. LOW PRESSURE
MOVING NORTH OF THE AREA WILL DRAG A COLD FRONT ACROSS THE WATERS
SATURDAY NIGHT...AND WINDS WILL TURN ABRUPTLY TO THE NORTH AT
15-20 KTS BY SUNDAY MORNING. SEAS ON SATURDAY WILL BE GENERALLY
2-4 FT REGARDLESS OF WIND DIRECTION...BUT WILL BEGIN TO RISE LATE
BEHIND THE COLD FRONT.
GALE WATCH HAS BEEN HOISTED FOR THE NC WATERS BEGINNING SUNDAY
MORNING...AND THERE IS PRETTY HIGH CONFIDENCE IN A GALE OCCURRING
SUNDAY AS A STRONG WEDGE OF HIGH PRESSURE BUILDS DOWN THE COAST.
THIS WILL CAUSE A TIGHT GRADIENT OVER THE WATERS...AND WIND WILL
BECOME NE AT 20-30 KTS ON SUNDAY...WITH FREQUENT GUSTS TO 35 KTS OR
MORE EXPECTED ACROSS THE NC WATERS. THERE IS LOWER CONFIDENCE IN
GALE-FORCE WINDS ACROSS SC WATERS...BUT AT LEAST A STRONG SMALL
CRAFT ADVISORY IS EXPECTED. THESE STRONG WINDS WILL ALSO PUSH SEAS
UP TO TO 5-9 FT ON SUNDAY...WITH THE EXCEPTION BEING THE WAVE
SHADOWED REGION SW OF BRUNSWICK COUNTY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...NEXT WEEK WILL NOT BE THE BEST OF TIMES FOR THE
MARINE COMMUNITY AS BLUSTERY CONDITIONS AND ELEVATED SEAS WILL
CONTINUE. FOR MONDAY A POTENT NORTHERLY FLOW WILL CONTINUE AS LOW
PRESSURE MOVES WELL OFF TO THE NORTHEAST AND MASSIVE HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. EXPECT WINDS OF 20-25 KNOTS...POSSIBLY
HIGHER WITH CERTAIN SMALL CRAFT CONDITIONS AND POSSIBLY GALES. THE
WINDS DO DIMINISH THROUGHOUT THE DAY TO SETTLE AT 10-15 KNOTS BY
TUESDAY MORNING. HERE THE WINDS WILL REMAIN THROUGH WEDNESDAY. SEAS
WILL BE HIGHEST MONDAY WITH 3-6 FEET DROPPING TO 2-5 FEET TUESDAY
AND WEDNESDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 700 PM WEDNESDAY...THE FULL MOON IS ON SATURDAY. WE EXPECT
ELEVATED WATER LEVELS DURING THE TIME OF HIGH TIDE THROUGH THE
WEEKEND. THE MORNING HIGH TIDE WILL BE HIGHEST AND THIS IS WHEN WE
EXPECT THE TIDE TO COME UP WELL ONTO THE BEACH. STRONG NNE WINDS
SUNDAY AND SUNDAY NIGHT WILL HELP TO ENHANCE THE ASTRONOMICAL EFFECTS.
THE LOWER CAPE FEAR RIVER WILL ALSO EXPERIENCE HIGHER THAN
PREDICTED WATER LEVELS AND MAY REACH COASTAL FLOOD ADVISORY
CRITERIA DURING THE MORNING HIGH TIDE THROUGH THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR
AMZ250-252.
&&
$$
NEAR TERM...RJD
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...DL
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
149 AM EST THU DEC 4 2014
.SYNOPSIS...A COLD FRONT WILL DRIFT SOUTH THROUGH OUR AREA THIS
MORNING. COOL SURFACE HIGH PRESSURE WILL THEN RIDGE SOUTH ACROSS THE
MIDDLE ATLANTIC AND CAROLINAS THROUGH FRIDAY NIGHT...BENEATH A
COUPLE OF PASSING UPPER LEVEL DISTURBANCES. THE FRONT WILL WEAKEN
AND RETREAT NORTH AS A WARM FRONT SATURDAY...JUST AHEAD OF ANOTHER
COLD FRONT THAT WILL MOVE THROUGH THE AREA SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 PM WEDNESDAY...
COLD FRONT JUST ABOUT TO ENTER THE WESTERN PART OF THE CWA... AND
SHOULD CROSS THE AREA OVERNIGHT. LACK OF UPPER LEVEL SUPPORT... DRY
AIR THROUGH MUCH OF THE MID AND LOW LEVELS... EXCEPT FOR THE NEAR
SURFACE LAYER AS SHOWN ON THE KGSO AND KMHX SOUNDINGS... WILL
PRECLUDE ANY PRECIPITATION IN ASSOCIATION WITH ITS PASSAGE. PATCHY
FOG... SOME LOCALLY DENSE... HAS FORMED AHEAD OF THE FRONT... BUT
WILL BE SCOURED OUT ALONG WITH THE LOW CLOUDS OVER THE NEXT FEW
HOURS AS MIXING INCREASES. UPPER LEVEL MOISTURE AND HIGH CLOUDS WILL
REMAIN ACROSS THE AREA. LOWS IN THE UPPER 30S TO MID 40S NORTH TO
SOUTH.
THURSDAY AND THURSDAY NIGHT...A SERIES OF MID-LEVEL SHORTWAVES ARE
FORECAST BY THE NAM AND THE GFS TO MOVE THROUGH CENTRAL NORTH
CAROLINA IN THIS PERIOD. THE STRONGEST ON BOTH OF THOSE SETS OF
GUIDANCE IS THURSDAY...COINCIDENT WITH A MID-LEVEL WAVE MOVING EAST
OUT OF THE SOUTHERN PLAINS ON WATER VAPOR IMAGERY. DURING THIS
TIME...OVER MOST OF CENTRAL NORTH CAROLINA THERE SHOULD BE 850MB
THETA-E TROUGHINESS...SO OVERALL MOISTURE SHOULD BE LIMITED EXCEPT
IN THE UPPER-LEVELS...AND POSSIBLY IN THE BOUNDARY LAYER OVER THE
FAR SOUTH ALTHOUGH LIFT IS FORECAST TO BE MEAGER WITH BASICALLY
850MB DIVERGENCE AND LITTLE UPPER DIFFLUENCE. BY THURSDAY NIGHT...
OVERALL MOISTURE STARTS TO INCREASE ON THE WEST SIDE OF THE SURFACE
HIGH...WITH MORE OF THE MOISTURE INCREASE OVER THE MOUNTAINS INTO
VIRGINIA. BOTH THE GFS AND THE NAM SHOW SLIGHT ISENTROPIC LIFT ON
THE 300K SURFACE OVER THE NORTHWEST PIEDMONT THURSDAY NIGHT...WITH
THE GFS AND NAM BUFR SOUNDINGS NOTING MOISTENING OF THE 850MB LAYER
BUT WITH THE NAM SHOWING MORE MOISTENING OF THE MID-LAYERS. MOS
GUIDANCE POPS ARE CREEPING UP INTO THE 30S ESPECIALLY FROM RALEIGH
NORTH AND WEST...BUT GUIDANCE QPF STAYS JUST BELOW ZERO IN CENTRAL
NORTH CAROLINA AND HRRR WRF GUIDANCE KEEPS THE APPEARANCE OF ANY
MEASURABLE RAIN JUST TO OUR NORTH AND WEST. AVERAGING THE DRIER GFS
AND THE MORE MOIST NAM WITH THE HRRR AND MOS GUIDANCE SUGGESTS A
SLIGHT CHANCE OF RAIN OR SPRINKLES THURSDAY NIGHT MAINLY NORTH OF A
LINE FROM ABOUT KEXX TO KTDF.
1000-850MB THICKNESSES WOULD SUPPORT HIGHS AT LEAST A CATEGORY ABOVE
GUIDANCE FOR THURSDAY...BUT BEHIND THE FRONT AND WITH AT LEAST SOME
PERIODS OF HIGH CLOUDS...WILL LEAN TOWARD THE MOS GUIDANCE VALUES
WHICH ARE VERY CLOSE BETWEEN THE MET AND THE MAV...FOR HIGHS IN THE
LOWER TO MID 50S OVERALL. COULD SEE THE WARMER MAV MINIMUM
TEMPERATURES VERIFY THURSDAY NIGHT IF THERE ARE ENOUGH HIGH CLOUDS
THROUGHOUT CENTRAL NORTH CAROLINA...BUT WITH A RELATIVE MINIMUM FOR
A TIME THURSDAY EVENING ESPECIALLY EAST LEANED TOWARD THE WARMER MAV
WEST AND TOWARD A BLEND OR THE COOLER VALUES EAST...37 TO 42.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 310 PM WEDNESDAY...
FRIDAY...DRY AIR SURFACE RIDGE WILL EXTEND ACROSS THE FORECAST AREA
EMANATING FROM A PARENT HIGH (1040+MB) OVER NORTHERN NEW ENGLAND.
ALOFT A S/W WILL BE LIFTING NEWD FROM THE SOUTHERN PLAINS INTO THE
LOWER OH VALLEY. WESTERLY FLOW IN THE MID-UPPER LEVELS WILL ADVECT
MOISTURE FROM THIS SYSTEM INTO CENTRAL NC. THER COMBINATION OF A
COOL STABLE AIR MASS NEAR THE SURFACE AND THE INCREASINGLY MOIST AIR
MASS ALOFT SHOULD RESULT IN A VARIABLY CLOUDY AND SEASONABLY COOL
DAY OVER OUR REGION. THICKER CLOUDS ANTICIPATED ACROSS THE NW SHOULD
HOLD TEMPS BELOW 50 DEGREES. SOME POTENTIAL FOR PARTIAL/FILTERED SUN
IN THE SE WHICH WILL ALLOW TEMPS TO WARM SOLIDLY INTO THE 50S.
FRIDAY NIGHT...THE LOWER OH VALLEY SYSTEM WILL ADVANCE FARTHER EAST.
INCREASING SOUTHERLY FLOW ABOVE THE SURFACE-BASED COOL DOME SHOULD
INITIATE SOME OVERRUNNING OVER THE PIEDMONT LATE FRIDAY NIGHT/EARLY
SATURDAY. CURRENTLY EXPECT ANY PRECIP TO BE SPOTTY AND
LIGHT...MAINLY CONFINED TO AREAS WEST-NW OF HIGHWAY 1. MAY SEE AREAS
OF FOG AS WELL. MIN TEMPS MID-UPPER 40S.
SATURDAY AND SATURDAY NIGHT...S/W AND ATTENDANT SFC FRONT WILL
CONTINUE TO LIFT E-NE. THIS WILL BRING AN INCREASING THREAT FOR RAIN
ACROSS CENTRAL NC...ESPECIALLY LATE MORNING THROUGH EARLY EVENING.
RESIDUAL CAD AIR MASS MAY HOLD ON LONGER IN THE FAVORED NW PIEDMONT
THAN CURRENTLY ADVERTISED BY THE MODELS. PLAN TO HOLD MAX TEMPS IN
THE TRIA AROUND 50...THOUGH IMMEDIATELY EAST-AND SOUTH OF THIS
REGION...TEMPS SHOULD RECOVER INTO THE MID 50S. IF RAIN SPOTTY
ACROSS THE SE...MAX TEMPS IN VICINITY OF CLINTON...FAYETTEVILLE AND
GOLDSBORO MAY CLIMB INTO THE LOWER 60S.
BEGIN TO SEE MODEL SOLUTIONS DIVERGE BY SATURDAY NIGHT WITH THE MORE
PROGRESSIVE GFS SWINGS THE TROUGH ACROSS OUR REGION IN THE EVENING
WITH PRECIP CHANCES DWINDLING OVERNIGHT. THE ECMWF IS MORE
SLUGGISH...TRACKING AN UPPER LEVEL INTO THE MID ATLANTIC...WHICH
MAINTAINS A CYCLONIC FLOW OVER OUR REGION...KEEPING SKIES OVERCAST
AND A THREAT FOR RAIN CONTINUING ACROSS OUR EASTERN COUNTIES WELL
INTO THE NIGHT. DIFFICULT TO SAY WITH A HIGH DEGREE OF CONFIDENCE
WHICH MODEL IS MORE CORRECT AS THEY BOTH HAVE DISPLAYED DECENT RUN-
TO-RUN CONTINUITY. WILL LEAN TOWARD THE PESSIMISTIC ECMWF FOR NOW
AND SEE IF MODEL TREND ONE WAY BY TOMORROW. WITH THE LINGERING CLOUD
COVERAGE AND WEAK LOW LEVEL CAA...HAVE RAISED MIN TEMPS UP A COUPLE
OF DEGREES FROM PREVIOUS FORECAST. MIN TEMPS LOW-MID 40S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 317 PM WEDNESDAY...
SUNDAY...FORECAST CONFIDENCE LOW AS HUGE DISPARITY AMONG MODEL
GUIDANCE THIS PERIOD. 12Z GFS DEPICTS A DRY AIR SURFACE RIDGE
EXTENDING ACROSS THE REGION. THIS WOULD RESULT IN SUNNY AND COOL
CONDITIONS. MEANWHILE THE 12Z ECMWF SLOWLY DRIFTS AN UPPER LEVEL
ACROSS THE CHESAPEAKE BAY REGION...MAINTAINING OVERCAST
SKIES...PATCHY LIGHT PRECIP AND COOL TEMPS ALONG WITH BRISK
CONDITIONS OVER OUR COASTAL PLAIN DUE TO PRESENCE OF A COASTAL LOW
OFFSHORE OF HATTERAS. PRESENTLY PREFER A WEAKER COUSIN OF THE 12Z
ECMWF AS SOME SEPARATION OF THE JET STREAMS EXPECTED. THIS YIELDS
BELOW NORMAL TEMPS WITH SOLID CHANCE FOR RAIN...MAINLY NORTH AND
EAST.
MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE REMAINS BELOW NORMAL
AS MEDIUM RANGE MODEL GUIDANCE OFFERING VARIED SOLUTIONS. DOES
APPEAR CERTAIN THAT WITH A L/W TROUGH OVER THE EASTERN U.S....HIGH
TEMPS WILL AVERAGE AT LEAST ONE TO TWO CATEGORIES BELOW NORMAL. IN
ADDITION...CLOUD COVERAGE WILL BE VARIABLE. GFS FAVORS LIGHT PRECIP
MONDAY-MONDAY EVENING WITH THE PASSAGE OF A SOUTHERN STREAM
SYSTEM...WHILE ECMWF FAVORS LATE TUESDAY INTO WEDNESDAY WHEN DIVES
ANOTHER SIGNIFICANT S/W SEWD FROM THE GREAT LAKES TOWARDS THE
SOUTHERN APPALACHIANS...SPINNING UP ANOTHER COASTAL LOW IN THE
PROCESS. FOR NOW...KEPT POPS MINIMAL (NO WORSE THAN SLIGHT
CHANCE/SMALL CHANCE).
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
A COLD FRONT AND ASSOCIATED NORTHERLY WIND AND TRAILING DRIER AIR
WILL CAUSE PRECEDING DENSE FOG AND LOW CLOUDS AT KRWI AND KFAY TO
DISPERSE DURING THE NEXT SEVERAL HOURS...WHILE VFR CONDITIONS
PREVAIL AT KRDU AND IN THE TRIAD. THE LOW LEVEL MOISTURE...SLOWEST
TO DISPERSE AT KFAY...WILL LIKELY LIFT AND MORPH INTO A
STRATOCUMULUS FIELD...THROUGH IFR-MVFR RANGE...BETWEEN 12-16Z AT
KFAY...BEFORE SCATTERING AND LIFTING TO VFR THEREAFTER. AN
OCCASIONAL MVFR CEILINGS WILL REMAIN POSSIBLE AT KFAY DURING THE
AFTERNOON HOURS...WITH JUST A SCATTERING OF 3-5 THOUSAND FT
STRATOCUMULUS BENEATH MID-HIGH LEVEL CEILINGS OTHERWISE AND
ELSEWHERE. SURFACE WINDS WILL VEER FROM NW TO NE THROUGH THE
MORNING...AND INCREASE BRIEFLY INTO THE 7-12 KT RANGE WITH GUSTS
INTO THE MID-UPPER TEENS KTS AT EASTERN TERMINALS THROUGH
16Z...BEFORE LESSENING BY MIDDAY-EARLY AFTERNOON.
OUTLOOK: SOUTHWEST FLOW ALOFT WILL GLIDE ATOP NORTHEASTERLY SURFACE
FLOW AND RESULT IN PERIODS OF MVFR TO POSSIBLY IFR CEILINGS TONIGHT
THROUGH SATURDAY...WITH THE LOWER CEILINGS MOST PROBABLE SAT
MORNING. A FRONTAL SYSTEM AND ASSOCIATED CHANCE OF RAIN AND SUB-VFR
CONDITIONS WILL AFFECT OUR REGION SAT AND SAT NIGHT...FOLLOWED BY
HIGH PRESSURE AND NE FLOW THROUGH EARLY NEXT WEEK. THE NE FLOW COULD
CAUSE SOME MVFR CEILINGS TO LINGER...ESPECIALLY AT EASTERN
TERMINALS...THROUGH SUNDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
NCZ011-026>028-039>041.
DENSE FOG ADVISORY UNTIL 7 AM EST THIS MORNING FOR NCZ042-043-
073>078-083>086-088-089.
&&
$$
SYNOPSIS...MWS
NEAR TERM...DJF/SEC
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
111 AM EST THU DEC 4 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS MORNING. SURFACE HIGH
PRESSURE WILL BUILD IN... WHILE UPPER LEVEL DISTURBANCE MOVE
ACROSS THE AREA THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 PM WEDNESDAY...
COLD FRONT JUST ABOUT TO ENTER THE WESTERN PART OF THE CWA... AND
SHOULD CROSS THE AREA OVERNIGHT. LACK OF UPPER LEVEL SUPPORT... DRY
AIR THROUGH MUCH OF THE MID AND LOW LEVELS... EXCEPT FOR THE NEAR
SURFACE LAYER AS SHOWN ON THE KGSO AND KMHX SOUNDINGS... WILL
PRECLUDE ANY PRECIPITATION IN ASSOCIATION WITH ITS PASSAGE. PATCHY
FOG... SOME LOCALLY DENSE... HAS FORMED AHEAD OF THE FRONT... BUT
WILL BE SCOURED OUT ALONG WITH THE LOW CLOUDS OVER THE NEXT FEW
HOURS AS MIXING INCREASES. UPPER LEVEL MOISTURE AND HIGH CLOUDS WILL
REMAIN ACROSS THE AREA. LOWS IN THE UPPER 30S TO MID 40S NORTH TO
SOUTH.
THURSDAY AND THURSDAY NIGHT...A SERIES OF MID-LEVEL SHORTWAVES ARE
FORECAST BY THE NAM AND THE GFS TO MOVE THROUGH CENTRAL NORTH
CAROLINA IN THIS PERIOD. THE STRONGEST ON BOTH OF THOSE SETS OF
GUIDANCE IS THURSDAY...COINCIDENT WITH A MID-LEVEL WAVE MOVING EAST
OUT OF THE SOUTHERN PLAINS ON WATER VAPOR IMAGERY. DURING THIS
TIME...OVER MOST OF CENTRAL NORTH CAROLINA THERE SHOULD BE 850MB
THETA-E TROUGHINESS...SO OVERALL MOISTURE SHOULD BE LIMITED EXCEPT
IN THE UPPER-LEVELS...AND POSSIBLY IN THE BOUNDARY LAYER OVER THE
FAR SOUTH ALTHOUGH LIFT IS FORECAST TO BE MEAGER WITH BASICALLY
850MB DIVERGENCE AND LITTLE UPPER DIFFLUENCE. BY THURSDAY NIGHT...
OVERALL MOISTURE STARTS TO INCREASE ON THE WEST SIDE OF THE SURFACE
HIGH...WITH MORE OF THE MOISTURE INCREASE OVER THE MOUNTAINS INTO
VIRGINIA. BOTH THE GFS AND THE NAM SHOW SLIGHT ISENTROPIC LIFT ON
THE 300K SURFACE OVER THE NORTHWEST PIEDMONT THURSDAY NIGHT...WITH
THE GFS AND NAM BUFR SOUNDINGS NOTING MOISTENING OF THE 850MB LAYER
BUT WITH THE NAM SHOWING MORE MOISTENING OF THE MID-LAYERS. MOS
GUIDANCE POPS ARE CREEPING UP INTO THE 30S ESPECIALLY FROM RALEIGH
NORTH AND WEST...BUT GUIDANCE QPF STAYS JUST BELOW ZERO IN CENTRAL
NORTH CAROLINA AND HRRR WRF GUIDANCE KEEPS THE APPEARANCE OF ANY
MEASURABLE RAIN JUST TO OUR NORTH AND WEST. AVERAGING THE DRIER GFS
AND THE MORE MOIST NAM WITH THE HRRR AND MOS GUIDANCE SUGGESTS A
SLIGHT CHANCE OF RAIN OR SPRINKLES THURSDAY NIGHT MAINLY NORTH OF A
LINE FROM ABOUT KEXX TO KTDF.
1000-850MB THICKNESSES WOULD SUPPORT HIGHS AT LEAST A CATEGORY ABOVE
GUIDANCE FOR THURSDAY...BUT BEHIND THE FRONT AND WITH AT LEAST SOME
PERIODS OF HIGH CLOUDS...WILL LEAN TOWARD THE MOS GUIDANCE VALUES
WHICH ARE VERY CLOSE BETWEEN THE MET AND THE MAV...FOR HIGHS IN THE
LOWER TO MID 50S OVERALL. COULD SEE THE WARMER MAV MINIMUM
TEMPERATURES VERIFY THURSDAY NIGHT IF THERE ARE ENOUGH HIGH CLOUDS
THROUGHOUT CENTRAL NORTH CAROLINA...BUT WITH A RELATIVE MINIMUM FOR
A TIME THURSDAY EVENING ESPECIALLY EAST LEANED TOWARD THE WARMER MAV
WEST AND TOWARD A BLEND OR THE COOLER VALUES EAST...37 TO 42.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 310 PM WEDNESDAY...
FRIDAY...DRY AIR SURFACE RIDGE WILL EXTEND ACROSS THE FORECAST AREA
EMANATING FROM A PARENT HIGH (1040+MB) OVER NORTHERN NEW ENGLAND.
ALOFT A S/W WILL BE LIFTING NEWD FROM THE SOUTHERN PLAINS INTO THE
LOWER OH VALLEY. WESTERLY FLOW IN THE MID-UPPER LEVELS WILL ADVECT
MOISTURE FROM THIS SYSTEM INTO CENTRAL NC. THER COMBINATION OF A
COOL STABLE AIR MASS NEAR THE SURFACE AND THE INCREASINGLY MOIST AIR
MASS ALOFT SHOULD RESULT IN A VARIABLY CLOUDY AND SEASONABLY COOL
DAY OVER OUR REGION. THICKER CLOUDS ANTICIPATED ACROSS THE NW SHOULD
HOLD TEMPS BELOW 50 DEGREES. SOME POTENTIAL FOR PARTIAL/FILTERED SUN
IN THE SE WHICH WILL ALLOW TEMPS TO WARM SOLIDLY INTO THE 50S.
FRIDAY NIGHT...THE LOWER OH VALLEY SYSTEM WILL ADVANCE FARTHER EAST.
INCREASING SOUTHERLY FLOW ABOVE THE SURFACE-BASED COOL DOME SHOULD
INITIATE SOME OVERRUNNING OVER THE PIEDMONT LATE FRIDAY NIGHT/EARLY
SATURDAY. CURRENTLY EXPECT ANY PRECIP TO BE SPOTTY AND
LIGHT...MAINLY CONFINED TO AREAS WEST-NW OF HIGHWAY 1. MAY SEE AREAS
OF FOG AS WELL. MIN TEMPS MID-UPPER 40S.
SATURDAY AND SATURDAY NIGHT...S/W AND ATTENDANT SFC FRONT WILL
CONTINUE TO LIFT E-NE. THIS WILL BRING AN INCREASING THREAT FOR RAIN
ACROSS CENTRAL NC...ESPECIALLY LATE MORNING THROUGH EARLY EVENING.
RESIDUAL CAD AIR MASS MAY HOLD ON LONGER IN THE FAVORED NW PIEDMONT
THAN CURRENTLY ADVERTISED BY THE MODELS. PLAN TO HOLD MAX TEMPS IN
THE TRIA AROUND 50...THOUGH IMMEDIATELY EAST-AND SOUTH OF THIS
REGION...TEMPS SHOULD RECOVER INTO THE MID 50S. IF RAIN SPOTTY
ACROSS THE SE...MAX TEMPS IN VICINITY OF CLINTON...FAYETTEVILLE AND
GOLDSBORO MAY CLIMB INTO THE LOWER 60S.
BEGIN TO SEE MODEL SOLUTIONS DIVERGE BY SATURDAY NIGHT WITH THE MORE
PROGRESSIVE GFS SWINGS THE TROUGH ACROSS OUR REGION IN THE EVENING
WITH PRECIP CHANCES DWINDLING OVERNIGHT. THE ECMWF IS MORE
SLUGGISH...TRACKING AN UPPER LEVEL INTO THE MID ATLANTIC...WHICH
MAINTAINS A CYCLONIC FLOW OVER OUR REGION...KEEPING SKIES OVERCAST
AND A THREAT FOR RAIN CONTINUING ACROSS OUR EASTERN COUNTIES WELL
INTO THE NIGHT. DIFFICULT TO SAY WITH A HIGH DEGREE OF CONFIDENCE
WHICH MODEL IS MORE CORRECT AS THEY BOTH HAVE DISPLAYED DECENT RUN-
TO-RUN CONTINUITY. WILL LEAN TOWARD THE PESSIMISTIC ECMWF FOR NOW
AND SEE IF MODEL TREND ONE WAY BY TOMORROW. WITH THE LINGERING CLOUD
COVERAGE AND WEAK LOW LEVEL CAA...HAVE RAISED MIN TEMPS UP A COUPLE
OF DEGREES FROM PREVIOUS FORECAST. MIN TEMPS LOW-MID 40S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 317 PM WEDNESDAY...
SUNDAY...FORECAST CONFIDENCE LOW AS HUGE DISPARITY AMONG MODEL
GUIDANCE THIS PERIOD. 12Z GFS DEPICTS A DRY AIR SURFACE RIDGE
EXTENDING ACROSS THE REGION. THIS WOULD RESULT IN SUNNY AND COOL
CONDITIONS. MEANWHILE THE 12Z ECMWF SLOWLY DRIFTS AN UPPER LEVEL
ACROSS THE CHESAPEAKE BAY REGION...MAINTAINING OVERCAST
SKIES...PATCHY LIGHT PRECIP AND COOL TEMPS ALONG WITH BRISK
CONDITIONS OVER OUR COASTAL PLAIN DUE TO PRESENCE OF A COASTAL LOW
OFFSHORE OF HATTERAS. PRESENTLY PREFER A WEAKER COUSIN OF THE 12Z
ECMWF AS SOME SEPARATION OF THE JET STREAMS EXPECTED. THIS YIELDS
BELOW NORMAL TEMPS WITH SOLID CHANCE FOR RAIN...MAINLY NORTH AND
EAST.
MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE REMAINS BELOW NORMAL
AS MEDIUM RANGE MODEL GUIDANCE OFFERING VARIED SOLUTIONS. DOES
APPEAR CERTAIN THAT WITH A L/W TROUGH OVER THE EASTERN U.S....HIGH
TEMPS WILL AVERAGE AT LEAST ONE TO TWO CATEGORIES BELOW NORMAL. IN
ADDITION...CLOUD COVERAGE WILL BE VARIABLE. GFS FAVORS LIGHT PRECIP
MONDAY-MONDAY EVENING WITH THE PASSAGE OF A SOUTHERN STREAM
SYSTEM...WHILE ECMWF FAVORS LATE TUESDAY INTO WEDNESDAY WHEN DIVES
ANOTHER SIGNIFICANT S/W SEWD FROM THE GREAT LAKES TOWARDS THE
SOUTHERN APPALACHIANS...SPINNING UP ANOTHER COASTAL LOW IN THE
PROCESS. FOR NOW...KEPT POPS MINIMAL (NO WORSE THAN SLIGHT
CHANCE/SMALL CHANCE).
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 645 PM WEDNESDAY...
24 HOUR TAF PERIOD: PRETTY LOW CONFIDENCE FORECAST CONCERNING
AVIATION CONDITIONS OVER THE NEXT 24 HOURS. A FRONTAL SYSTEM JUST TO
THE NORTHWEST OF THE AREA AND THE MODELS HANDLING OF THIS SYSTEM IS
VERY MUCH IN QUESTION. IN THE VERY NEAR TERM EXPECT TRIAD TERMINALS
TO HAVE SOME VISIBILITY PROBLEMS BEFORE FRONTAL PASSAGE WHICH AT
THIS HOUR IS STILL ALONG THE FOOTHILLS OF NC AND VA. WINDS WILL BE
LIGHT AND VARIABLE BUT ONCE THE FRONT GOES THROUGH SOMETIME AROUND 2
OR 3Z...ANY FOG THAT FORMS IN THE MEANTIME SHOULD QUICKLY DISSIPATE.
THE FRONT WILL TAKE LONGER TO REACH EASTERN TERMINALS AND THUS AN
EXTENDED PERIOD OF DECREASED VISIBILITIES THROUGH 7 OR 8 Z WILL BE
POSSIBLE. EVENTUALLY THE FRONT WILL MAKE IT THROUGH ALL TERMINALS
AND WINDS WILL SWING AROUND TO NORTHEASTERLY FOR THURSDAY AT 5-10
KTS. THERE WILL REMAIN A QUESTION OF WHETHER OR NOT CEILINGS WILL BE
MVFR OR VFR THURSDAY AFTERNOON AS THE NAM MODEL INDICATES LOWER
CEILINGS PROBABLE BUT THE GFS KEEPS CEILINGS IN THE 5 KFT VICINITY.
WILL WAIT FOR FURTHER GUIDANCE TO COME IN AND COVER FOR NOW WITH
SCATTERED MVFR CEILINGS BUT THESE COULD BE INCREASED TO BROKEN OR
OVERCAST WITH THE NEXT FORECAST PACKAGE.
LONG TERM: THE LONG TERM WILL ENCOMPASS AN EXTENDED PERIOD OF
UNSETTLED WEATHER WITH SATURDAY THE MOST PESSIMISTIC DAY FOR
AVIATION CONDITIONS. THESE WILL CONTINUE INTO SUNDAY BEFORE MODEL
SOLUTIONS DIVERGE INTO EARLY NEXT WEEK...RESULTING IN A LOW
CONFIDENCE FORECAST FOR THE EARLY PART OF NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
NCZ011-026>028-039>041.
DENSE FOG ADVISORY UNTIL 7 AM EST THIS MORNING FOR NCZ042-043-
073>078-083>086-088-089.
&&
$$
SYNOPSIS...DJF/SEC
NEAR TERM...DJF/SEC
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...RE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
924 PM CST FRI DEC 5 2014
.UPDATE...
ISSUED AT 923 PM CST FRI DEC 5 2014
FOR LATE EVENING UPDATE MAIN CONCERN WAS PRECIPITATION OVER THE
FAR SOUTHWEST. LATEST HIGH-RES MODELS WERE HAVING SOME TROUBLE ON
PLACEMENT OF PRECIPITATION THIS EVENING...BUT REGIONAL RADAR
MOSAIC ALONG WITH BOWMAN ARB RADAR INDICATED VERY LIGHT
PRECIPITATION SHIFTING TOWARDS WEST CENTRAL AND SOUTHWEST NORTH
DAKOTA. THEREFORE...HAVE SPREAD LOW POPS THROUGH THE SOUTHWEST.
NEXT CONCERN WAS PRECIP TYPE AS SOME WARMER AIR ALOFT IS STARTING
TO PUSH TOWARDS THE FAR SOUTHWEST. WITH THIS...HAVE ADDED THE
MENTION OF POSSIBLE SLEET/FREEZING RAIN...ALTHOUGH CHANCES AND
COVERAGE WILL BE VERY LOW. ONLY OTHER CHANGE FOR UPDATE WAS
DROPPING LOW TEMPERATURES A BIT OVER THE NORTHWEST/NORTH CENTRAL
AS OBBS JUST NORTH OF THE CANADIAN BORDER HAVE ALREADY DIPPED DOWN
TOWARDS ZERO. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 621 PM CST FRI DEC 5 2014
MAIN CHANGE FOR EARLY EVENING UPDATE WAS TO INCREASE CLOUD COVER
ACROSS ALL AREAS EXCEPT FAR SOUTH CENTRAL/JAMES RIVER VALLEY AS
BROAD AREA CONTINUES TO SHIFT SOUTHEAST. WILL HAVE TO KEEP AN
EYE ON TEMPERATURES THROUGH THE EVENING AS WHEREVER THERE ARE
BREAKS IN THE CLOUD COVER OVER THE NORTH...THE TEMPERATURE HAS
DROPPED QUICKLY. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
CURRENTLY...HIGH PRESSURE OVER NORTHWEST NORTH DAKOTA THIS EARLY
AFTERNOON IS FORECAST TO MOVE EAST ACROSS THE FORECAST AREA
TONIGHT. IFR STRATUS REMAINS OVER NORTHWEST NORTH DAKOTA FROM
CROSBY AND WILLISTON...EAST TO STANLEY...BUT HAVING A HARD TIME
MAKING IT MUCH FARTHER EAST THIS AFTERNOON. TEMPERATURES RANGED
FROM THE UPPER TEENS-LOW 20S NORTH TO UPPER 20S-LOW 30S SOUTH.
MAIN CONCERN FOR THE SHORT TERM PERIOD IS STRATUS/FOG
POSSIBILITIES AND POSSIBLE LIGHT PRECIPITATION ACROSS THE NORTH.
THE 05 DEC 12 UTC NAM AND MESOSCALE MODELS HAVE BEEN HINTING AT A
BAND OF LIGHT PRECIPITATION MOVING ACROSS NORTHERN NORTH DAKOTA
LATE TONIGHT INTO SATURDAY MORNING. THE 18 UTC NAM HAS DISPLACED
THE PRECIPITATION FARTHER SOUTH...BUT RAP/HRRR HAVE BEEN PRETTY
CONSISTENT IN KEEPING VERY LIGHT PRECIPITATION ACROSS THE NORTH.
HAVE ADDED SOME SLIGHT CHANCE POPS NORTHWEST AND NORTH CENTRAL
LATER THIS EVENING INTO SATURDAY MORNING...TAPERING TO ONLY
FLURRIES AS PRECIPITATION MOVES FROM NORTH CENTRAL INTO NORTHEAST
ND. HAVE KEPT PRECIPITATION ALL SNOW AS IT LOOKS LIKE THE WARMER
TEMPERATURES ALOFT DO NOT ARRIVE UNTIL BEST FORCING HAS ALREADY
PASSED...THUS PRECIP SHOULD REMAIN ALL SNOW.
MESOSCALE MODELS CONTINUE TO SHOW INCREASING LOW LEVEL MOISTURE
ACROSS THE NORTH AND EAST THIS AFTERNOON AND THIS EVENING...THEN
POSSIBLY SHIFTING MORE TO THE SOUTHWEST LATER TONIGHT AS SOUTHEAST
FLOW KICKS IN ON THE BACK SIDE OF THE SURFACE HIGH. HAVE OPTED TO
MENTION PATCHY FOG TONIGHT AS RAP BUFR SOUNDINGS DO SUGGEST FOG
MOST AREAS. ALSO HAVE BUMPED UP SKY COVER LATE EVENING THROUGH
SATURDAY MORNING. TEMPERATURES ALSO TRICKY AS WE WILL LIKELY SEE A
QUICK DROP THIS EVENING EAST WITH RISING TEMPERATURES LATE.
PERHAPS A QUICK DROP CENTRAL/WEST WITH RISING TEMPERATURES LATE
EVENING INTO THE OVERNIGHT AND THEN DROPPING OFF BY MORNING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
SATURDAY NIGHT THROUGH SUNDAY NIGHT...AN UPPER LEVEL LOW/SHARP
TROUGH WITH AN ASSOCIATED SURFACE COLD FRONT WILL PUSH ACROSS
WESTERN AND CENTRAL NORTH DAKOTA SUNDAY INTO SUNDAY NIGHT. SOUTH TO
SOUTHWESTERLY FLOW AHEAD OF THIS SYSTEM WILL ALLOW FOR WARMING
THROUGH SUNDAY MORNING. THE H85 BAROCLINIC ZONE BEGINS TO PUSH
ACROSS THE FAR WEST BY 18Z AND THEN SHIFTS INTO CENTRAL NORTH DAKOTA
SUNDAY AFTERNOON/EVENING. STILL SOME THREAT OF A WINTRY MIX ACROSS
NORTHERN NORTH DAKOTA...BUT IT APPEARS THE BETTER CHANCE FOR
PRECIPITATION MAY OCCUR SUNDAY EVENING INTO SUNDAY NIGHT ACROSS
NORTHERN NORTH DAKOTA...ASSOCIATED WITH A WEAK/NARROW TROWAL PER GFS
H7-H5 EQUIVALENT POTENTIAL TEMPERATURE. AMOUNTS LOOK VERY
LIGHT...PERHAPS A TENTH OR TWO OF AN INCH OF SNOW. WEST TO NORTHWEST
WINDS INCREASE IN THE WEST DURING THE AFTERNOON WITH THE STRONGEST
WINDS NOT ARRIVING UNTIL SUNDAY NIGHT FOR CENTRAL NORTH DAKOTA.
EXPECT 20 TO 35MPH WINDS DEVELOPING BEHIND THIS SYSTEM. WITH LIMITED
SNOW SHOWERS AND QPF...AT THIS TIME HAVE NOT MENTIONED ANY BLOWING
SNOW.
MONDAY THROUGH FRIDAY...BRISK NORTHWEST WINDS CONTINUE DURING THE
DAY MONDAY BUT ABATE MONDAY EVENING. COLDER MONDAY AFTERNOON WITH
HIGHS 20 NORTHEAST TO MID 30S FAR SOUTHWEST. THEREAFTER A
PROGRESSIVE PATTERN ENSUES WITH NO SIGNIFICANT SHORTWAVES FORECAST
THROUGH THE REMAINDER OF THE LONG TERM PERIOD. A WARMING TREND IS
STILL IN THE FORECAST WITH HIGHS 35F TO 45F WEDNESDAY THROUGH
FRIDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 621 PM CST FRI DEC 5 2014
IFR CIGS WILL CONTINUE OVER NORTHERN NORTH DAKOTA THROUGH MUCH OF
THE NIGHT AFFECTING THE KISN AND KMOT TERMINALS. FURTHER
SOUTH...MID LEVEL CLOUD COVER WILL REMAIN...THOUGH LCL FOG MAY
DEVELOP OVERNIGHT INTO EARLY SATURDAY AFFECTING KDIK-KBIS-KJMS. AN
...AMD NOT SKED... HAS BEEN POSTED TO THE KBIS TAF DUE TO PROBLEMS
WITH THE VISIBILITY SENSOR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...TWH
LONG TERM...KS
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
629 PM CST FRI DEC 5 2014
.UPDATE...
ISSUED AT 621 PM CST FRI DEC 5 2014
MAIN CHANGE FOR EARLY EVENING UPDATE WAS TO INCREASE CLOUD COVER
ACROSS ALL AREAS EXCEPT FAR SOUTH CENTRAL/JAMES RIVER VALLEY AS
BROAD AREA CONTINUES TO SHIFT SOUTHEAST. WILL HAVE TO KEEP AN
EYE ON TEMPERATURES THROUGH THE EVENING AS WHEREVER THERE ARE
BREAKS IN THE CLOUD COVER OVER THE NORTH...THE TEMPERATURE HAS
DROPPED QUICKLY. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
CURRENTLY...HIGH PRESSURE OVER NORTHWEST NORTH DAKOTA THIS EARLY
AFTERNOON IS FORECAST TO MOVE EAST ACROSS THE FORECAST AREA
TONIGHT. IFR STRATUS REMAINS OVER NORTHWEST NORTH DAKOTA FROM
CROSBY AND WILLISTON...EAST TO STANLEY...BUT HAVING A HARD TIME
MAKING IT MUCH FARTHER EAST THIS AFTERNOON. TEMPERATURES RANGED
FROM THE UPPER TEENS-LOW 20S NORTH TO UPPER 20S-LOW 30S SOUTH.
MAIN CONCERN FOR THE SHORT TERM PERIOD IS STRATUS/FOG
POSSIBILITIES AND POSSIBLE LIGHT PRECIPITATION ACROSS THE NORTH.
THE 05 DEC 12 UTC NAM AND MESOSCALE MODELS HAVE BEEN HINTING AT A
BAND OF LIGHT PRECIPITATION MOVING ACROSS NORTHERN NORTH DAKOTA
LATE TONIGHT INTO SATURDAY MORNING. THE 18 UTC NAM HAS DISPLACED
THE PRECIPITATION FARTHER SOUTH...BUT RAP/HRRR HAVE BEEN PRETTY
CONSISTENT IN KEEPING VERY LIGHT PRECIPITATION ACROSS THE NORTH.
HAVE ADDED SOME SLIGHT CHANCE POPS NORTHWEST AND NORTH CENTRAL
LATER THIS EVENING INTO SATURDAY MORNING...TAPERING TO ONLY
FLURRIES AS PRECIPITATION MOVES FROM NORTH CENTRAL INTO NORTHEAST
ND. HAVE KEPT PRECIPITATION ALL SNOW AS IT LOOKS LIKE THE WARMER
TEMPERATURES ALOFT DO NOT ARRIVE UNTIL BEST FORCING HAS ALREADY
PASSED...THUS PRECIP SHOULD REMAIN ALL SNOW.
MESOSCALE MODELS CONTINUE TO SHOW INCREASING LOW LEVEL MOISTURE
ACROSS THE NORTH AND EAST THIS AFTERNOON AND THIS EVENING...THEN
POSSIBLY SHIFTING MORE TO THE SOUTHWEST LATER TONIGHT AS SOUTHEAST
FLOW KICKS IN ON THE BACK SIDE OF THE SURFACE HIGH. HAVE OPTED TO
MENTION PATCHY FOG TONIGHT AS RAP BUFR SOUNDINGS DO SUGGEST FOG
MOST AREAS. ALSO HAVE BUMPED UP SKY COVER LATE EVENING THROUGH
SATURDAY MORNING. TEMPERATURES ALSO TRICKY AS WE WILL LIKELY SEE A
QUICK DROP THIS EVENING EAST WITH RISING TEMPERATURES LATE.
PERHAPS A QUICK DROP CENTRAL/WEST WITH RISING TEMPERATURES LATE
EVENING INTO THE OVERNIGHT AND THEN DROPPING OFF BY MORNING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
SATURDAY NIGHT THROUGH SUNDAY NIGHT...AN UPPER LEVEL LOW/SHARP
TROUGH WITH AN ASSOCIATED SURFACE COLD FRONT WILL PUSH ACROSS
WESTERN AND CENTRAL NORTH DAKOTA SUNDAY INTO SUNDAY NIGHT. SOUTH TO
SOUTHWESTERLY FLOW AHEAD OF THIS SYSTEM WILL ALLOW FOR WARMING
THROUGH SUNDAY MORNING. THE H85 BAROCLINIC ZONE BEGINS TO PUSH
ACROSS THE FAR WEST BY 18Z AND THEN SHIFTS INTO CENTRAL NORTH DAKOTA
SUNDAY AFTERNOON/EVENING. STILL SOME THREAT OF A WINTRY MIX ACROSS
NORTHERN NORTH DAKOTA...BUT IT APPEARS THE BETTER CHANCE FOR
PRECIPITATION MAY OCCUR SUNDAY EVENING INTO SUNDAY NIGHT ACROSS
NORTHERN NORTH DAKOTA...ASSOCIATED WITH A WEAK/NARROW TROWAL PER GFS
H7-H5 EQUIVALENT POTENTIAL TEMPERATURE. AMOUNTS LOOK VERY
LIGHT...PERHAPS A TENTH OR TWO OF AN INCH OF SNOW. WEST TO NORTHWEST
WINDS INCREASE IN THE WEST DURING THE AFTERNOON WITH THE STRONGEST
WINDS NOT ARRIVING UNTIL SUNDAY NIGHT FOR CENTRAL NORTH DAKOTA.
EXPECT 20 TO 35MPH WINDS DEVELOPING BEHIND THIS SYSTEM. WITH LIMITED
SNOW SHOWERS AND QPF...AT THIS TIME HAVE NOT MENTIONED ANY BLOWING
SNOW.
MONDAY THROUGH FRIDAY...BRISK NORTHWEST WINDS CONTINUE DURING THE
DAY MONDAY BUT ABATE MONDAY EVENING. COLDER MONDAY AFTERNOON WITH
HIGHS 20 NORTHEAST TO MID 30S FAR SOUTHWEST. THEREAFTER A
PROGRESSIVE PATTERN ENSUES WITH NO SIGNIFICANT SHORTWAVES FORECAST
THROUGH THE REMAINDER OF THE LONG TERM PERIOD. A WARMING TREND IS
STILL IN THE FORECAST WITH HIGHS 35F TO 45F WEDNESDAY THROUGH
FRIDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 621 PM CST FRI DEC 5 2014
IFR CIGS WILL CONTINUE OVER NORTHERN NORTH DAKOTA THROUGH MUCH OF
THE NIGHT AFFECTING THE KISN AND KMOT TERMINALS. FURTHER
SOUTH...MID LEVEL CLOUD COVER WILL REMAIN...THOUGH LCL FOG MAY
DEVELOP OVERNIGHT INTO EARLY SATURDAY AFFECTING KDIK-KBIS-KJMS. AN
...AMD NOT SKED... HAS BEEN POSTED TO THE KBIS TAF DUE TO PROBLEMS
WITH THE VISIBILITY SENSOR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...TWH
LONG TERM...KS
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
311 PM EST THU DEC 4 2014
.SYNOPSIS...
SERIES OF LOW PRESSURE WAVES CROSS INTO THE WEEKEND. HIGH PRESSURE
SUNDAY. COLD FRONT EARLY NEXT WEEK MAY BE FOLLOWED A BY LONGER
PERIOD OF HIGH PRESSURE.
&&
.NEAR TERM /THROUGH FRIDAY/...
PRECIP EXPANDING NE A BIT QUICKER THAN PREVIOUS FORECAST. STILL A
SIGNIFICANT DRY LAYER IN THE LOWER LAYERS TO OVERCOME...BUT
IT WONT TAKE LONG FOR THIS TO ERODE ONCE THE PRECIP MOVES IN.
EXCEPTION BEING ACROSS SE OH AND N WV WHERE THE DRY LAYER IS A BIT
MORE ROBUST. USED LATEST HRRR FOR TIMING OF HIGH POPS IN THRU THIS
AFTERNOON AND EVENING. ALSO INSERTED A BRIEF PERIOD OF SLEET MIXING IN ON
THE LEADING EDGE ACROSS NE KY/ W WV/ AND SE OH. THIS MIX CAN BE
EXPECTED IN THE N MOUNTAINS AS WELL.
ONCE THIS WAVE MOVES BY...CWA LEFT WITH WARM FRONT THIS EVENING WITH
SHRA REGIME MAINLY N HALF OF CWA. WILL WATCH FOR A SURFACE LOW TO
ORGANIZE OVER THE TN VALLEY WITH A WARM FRONT APPENDAGE DEVELOPING
INTO AREA LATE TONIGHT. THIS WILL INCREASE THE COVERAGE OF PRECIP
HEADING INTO FRIDAY AS THE WARM FRONT SLOWLY SHIFTS INTO SE OH.
THERE MAY BE AN EXTENDED LULL IN PRECIP ACROSS SW VA AND SE WV
FRIDAY WITH THESE AREAS IN WARM SECTOR.
AFTER INTERROGATING HI RES MODELS AND SREF PROBS...ELECTED NOT TO
EXPAND THE FRZ RA ADVISORY TO RANDOLPH. ASIDE FROM A BRIEF MIX
LATER THIS AFTERNOON...EXPECT BULK OF PRECIP TONIGHT TO FALL AS
RAIN. THERE COULD BE A LITTLE FRZ RA ACROSS FAR EASTERN RANDOLPH
BUT DEFINITELY NOT A COUNTY WIDE AVG. IN FACT...THERE IS CONCERN
THAT TEMPS MAY WARM ENOUGH TONIGHT FOR RAIN EVEN OVER POCAHONTAS
COUNTY. HI RES NAM IS BY FAR COOLEST OF THE MODELS...KEEPING A SUB
FRZ THIN LAYER AROUND H9. ELEVATIONS ABOVE 3 KFT SHOULD GET INTO
WARM LAYER SUCH THAT RISING TEMPS ARE EXPECTED TONIGHT. IT SHOULD
BE QUITE MILD TOMORROW IN WARM SECTOR WHERE MID TO UPPER 50S WERE
CODED UP ACROSS SW VA UP TO I64. DOWNSLOPING COMPONENT PROBABLY
ALSO SENDS EKN INTO THE LOW 50S.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
VERY FEW CHANGES TO THE SHORT TERM FORECAST. KEEP THE HIGH POPS
GOING THROUGH THE SATURDAY PERIOD...DECREASING INTO SATURDAY NIGHT
WITH THE PASSAGE OF THE SURFACE LOW AND ACCOMPANYING UPPER LEVEL
TROUGH AXIS. EXPECTING A BATCH OF HEAVIER RAIN TO COME THROUGH IN
THE 09Z SATURDAY TIME FRAME WITH 850MB THETA E CONVERGENCE
PEAKING. AFTER ALL IS SAID AND DONE...1-1.5 INCHES OF RAIN IS NOT
OUT OF THE QUESTION BY SATURDAY NIGHT WHEN THE SYSTEM EXITS.
CLEARING SHOULD OCCUR QUICKLY SUNDAY AS THE FLOW WILL NOT GO TO
ITS TYPICAL NORTHWEST TRAJECTORY. LOOKING AT A NORTH NORTHEASTERLY
LOW LEVEL FLOW AND QUICK DRYING ALOFT...SO SHOULD SEE SOME SUN ON
SUNDAY. CIRRUS FROM THE NEXT SYSTEM FOR THE LONG TERM PERIOD WILL
BE ON ITS WAY IN QUICKLY AS IT ORGANIZES TO THE WEST.
AIRMASS BEHIND THE LOW PRESSURE SYSTEM WILL DROP HIGH TEMPERATURES
BACK INTO THE 40S FOR THE LOWLANDS...30S FOR THE MOUNTAINS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MODELS INDICATE A HIGH PRESSURE MOVING OVER NEW ENGLAND...EXTENDING
SOUTHWEST INTO WV SUNDAY NIGHT. ALTHOUGH A COLD AIR MASS WILL BE IN
PLACE...THIS PATTERN WOULD BRING EAST TO SOUTHEAST FLOW...CAPABLE TO
PRODUCE DOWNSLOPING WARMING ACROSS THE LOWLANDS SUNDAY NIGHT.
INCREASED FEW DEGREES FROM HPC GUIDANCE ACCORDINGLY.
FOR MONDAY...BUFKIT SOUNDINGS SHOW DRY AIR ALOFT WITH LIMITED
MOISTURE IN THE VERY LOW LEVELS WHILE A H500 WEAK SHORTWAVE CROSSES
THE AREA. KEPT LOW CHANCE POPS WITH THIS FEATURE...MORE ALONG THE
GFS SOLUTION. THE ECMWF BRINGS STRONG COLD AIR ADVECTION FOR THE
SAME TIME PERIOD WITH SUCH A WEAK WAVE. BELIEVE ECMWF IS OVERDOING
CAA SO PREFERRED THE GFS.
BY MONDAY NIGHT FLOW IN THE LOW LEVELS TURN NORTHWEST WITH SOME CAA
FROM BOTH MODELS. FIGURE A GOOD SET UP FOR UPSLOPE PCPN. THE GFS
BRINGS THE 0C LEVEL AROUND THE NORTHEAST MOUNTAINS WHILE IN THE
ECMWF...THE 0C LINE GOES WAY SOUTH OF THE AREA. WENT WITH A BLEND
SOLUTION EXPECTING CHANCE POPS WITH FEW SNOW SHOWERS OR MIX PCPN
OVER THE MOST FAVORABLE UPSLOPE AREAS...AND RAIN ELSEWHERE. PCPN IS
EXPECTED TO TAMPER OFF ON TUESDAY KEEPING CHANCE POPS OVER THE
EASTERN MOUNTAINS ESPECIALLY WITH THE UPSLOPE COMPONENT AND DRY
WEATHER SPREADING FROM SOUTHEAST OH...EAST.
DRY WEATHER EXPECTED THROUGH THE REST OF THE PERIOD AS A HIGH
PRESSURE BUILDS IN.
WENT CLOSE TO HPC TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AN UPPER LEVEL SYSTEM COMBINED WITH A WARM FRONTAL BOUNDARY WILL
ALLOW PRECIP TO OVERSPREAD MOST OF THE AREA THRU THE EVENING. THIS
WILL MAINLY BE IN THE FORM OF RA...SAVE FOR A BRIEF PERIOD OF
PL POSSIBLY ON THE FRONT END OF THE PRECIP THIS AFTERNOON. EXPECT
VSBY TO LOWER INTO MVFR AS THE PRECIP MOVES ALONG WITH A GRADUAL
LOWERING OF CIGS INTO MVFR HEADING INTO THIS EVENING.
ONCE THIS UPPER LEVEL SYSTEM PASSES...EXPECT A SHRA REGIME TO TAKE
HOLD WITH A WARM FRONTAL BOUNDARY LINGERING. AGAIN...RA EXPECTED
TO BE DOMINATE PRECIP TYPE AT ALL TAF SITES. SOME FRZ RA OR PL
MIXTURE IS EXPECTED IN THE N MOUNTAINS THIS EVENING. CIGS AND VSBY
EXPECTED TO LOWER INTO IFR TONIGHT FOR MOST TAF SITES WITH EKN
HOLDING OUT THE LONGEST.
A SFC LOW WILL ORGANIZE OVER TN VALLEY...WITH ANOTHER WARM FRONT
DEVELOPING INTO THE REGION FOR FRIDAY. THIS WILL INCREASE THE
COVERAGE OF PRECIP ONCE AGAIN...WITH MOST OF THE RA N AND W OF A
HTS/CRW/CKB LINE. CONDITIONS SHOULD IMPROVE FOR KCRW AND PERHAPS
KBKW ONCE INTO THE WARM SECTOR WHILE IFR CONDITIONS IN RA PERSIST
ELSEWHERE.
SFC FLOW WILL BE LIGHT AND VARIABLE...MAINLY FROM THE E. LIGHT W
FLOW ALOFT WILL BECOME LIGHT SW TONIGHT...INCREASING A BIT TOWARD
DAWN FRI.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS IN RAIN
MAY VARY OVERNIGHT TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H M M M M M H H H H L
HTS CONSISTENCY H H H L L L H H L L L L
BKW CONSISTENCY H H M H H H H H H H H M
EKN CONSISTENCY H H H H H M M M M H H M
PKB CONSISTENCY H H M M M M M M M H H M
CKB CONSISTENCY H H H H H H M M M H H H
AFTER 18Z FRIDAY...
IFR POSSIBLE OVERNIGHT FRIDAY INTO THE WEEKEND IN RAIN...WITH
FREEZING RAIN LIKELY IN THE NORTHERN MOUNTAINS...MAINLY E OF THE
CHEAT RIDGE...INTO FRIDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 8 PM THIS EVENING TO 11 AM EST
FRIDAY FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30/26
NEAR TERM...30
SHORT TERM...26
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
202 PM EST THU DEC 4 2014
.SYNOPSIS...
SERIES OF LOW PRESSURE WAVES CROSS INTO THE WEEKEND. HIGH PRESSURE
SUNDAY. COLD FRONT EARLY NEXT WEEK MAY BE FOLLOWED A BY LONGER
PERIOD OF HIGH PRESSURE.
&&
.NEAR TERM /THROUGH FRIDAY/...
PRECIP EXPANDING NE A BIT QUICKER THAN PREVIOUS FORECAST. STILL A
SIGNIFICANT DRY LAYER IN THE LOWER LAYERS TO OVERCOME...BUT
IT WONT TAKE LONG FOR THIS TO ERODE ONCE THE PRECIP MOVES IN.
EXCEPTION BEING ACROSS SE OH AND N WV WHERE THE DRY LAYER IS A BIT
MORE ROBUST. USED LATEST HRRR FOR TIMING OF HIGH POPS IN THRU THIS
AFTERNOON AND EVENING. ALSO INSERTED A BRIEF PERIOD OF SLEET MIXING IN ON
THE LEADING EDGE ACROSS NE KY/ W WV/ AND SE OH. THIS MIX CAN BE
EXPECTED IN THE N MOUNTAINS AS WELL.
ONCE THIS WAVE MOVES BY...CWA LEFT WITH WARM FRONT THIS EVENING WITH
SHRA REGIME MAINLY N HALF OF CWA. WILL WATCH FOR A SURFACE LOW TO
ORGANIZE OVER THE TN VALLEY WITH A WARM FRONT APPENDAGE DEVELOPING
INTO AREA LATE TONIGHT. THIS WILL INCREASE THE COVERAGE OF PRECIP
HEADING INTO FRIDAY AS THE WARM FRONT SLOWLY SHIFTS INTO SE OH.
THERE MAY BE AN EXTENDED LULL IN PRECIP ACROSS SW VA AND SE WV
FRIDAY WITH THESE AREAS IN WARM SECTOR.
AFTER INTERROGATING HI RES MODELS AND SREF PROBS...ELECTED NOT TO
EXPAND THE FRZ RA ADVISORY TO RANDOLPH. ASIDE FROM A BRIEF MIX
LATER THIS AFTERNOON...EXPECT BULK OF PRECIP TONIGHT TO FALL AS
RAIN. THERE COULD BE A LITTLE FRZ RA ACROSS FAR EASTERN RANDOLPH
BUT DEFINITELY NOT A COUNTY WIDE AVG. IN FACT...THERE IS CONCERN
THAT TEMPS MAY WARM ENOUGH TONIGHT FOR RAIN EVEN OVER POCAHONTAS
COUNTY. HI RES NAM IS BY FAR COOLEST OF THE MODELS...KEEPING A SUB
FRZ THIN LAYER AROUND H9. ELEVATIONS ABOVE 3 KFT SHOULD GET INTO
WARM LAYER SUCH THAT RISING TEMPS ARE EXPECTED TONIGHT. IT SHOULD
BE QUITE MILD TOMORROW IN WARM SECTOR WHERE MID TO UPPER 50S WERE
CODED UP ACROSS SW VA UP TO I64. DOWNSLOPING COMPONENT PROBABLY
ALSO SENDS EKN INTO THE LOW 50S.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
ACTIVE WEATHER IN THE SHORT TERM PERIOD. WARM FRONTAL BOUNDARY WILL
LIFT NORTH ACROSS THE AREA ON FRIDAY. WITH COLDER AIR EXPECTED TO BE
AT THE SURFACE ALONG THE HIGHER TERRAIN...AND THE WARMER AIR MOVING
IN ALOFT...THIS WILL SET UP A SCENARIO OF LIGHT FREEZING RAIN EARLY
FRIDAY ACROSS NORTHERN MOUNTAINS. THIS WILL TAPER OFF BY LATE
MORNING/EARLY AFTERNOON...AS LOW PRESSURE WAVE MOVES INTO THE
REGION...AND WARMER AIR IS ABLE TO ERODE AWAY THE COLDER SURFACE
TEMPERATURES...EVENTUALLY CHANGING ALL PRECIP TO RAIN.
LOTS OF MOISTURE EXPECTED ACROSS THE AREA DURING THIS EVENT WITH A
GOOD TAP OF GULF MOISTURE...WITH PW VALUES PROGGED TO RISE TO AROUND
1.1 TO 1.2 INCHES. EXPECTING A DECENT SHOT OF RAIN...PARTICULARLY
ACROSS THE NORTH...WHERE LOW IS EXPECTED TO TRACK. AT THIS
POINT...EXPECTING A GENERAL 1 TO 1.3 INCHES OF QPF. AT THIS
POINT...ISSUES ON AREA WATERWAYS IS NOT EXPECTED...BUT THIS WILL
NEED TO BE MONITORED AS THE EVENT APPROACHES.
LOW WILL MOVE OFF TO THE EAST SATURDAY INTO SUNDAY...WITH GRADUALLY
DRYING WEATHER FROM WEST TO EAST AS IT DOES SO. COULD BE SOME -DZ OR
-FZDZ AT THE END OF THE EVENT AS WARMER AIR WORKS ITS WAY IN ALOFT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MODELS INDICATE A HIGH PRESSURE MOVING OVER NEW ENGLAND...EXTENDING
SOUTHWEST INTO WV SUNDAY NIGHT. ALTHOUGH A COLD AIR MASS WILL BE IN
PLACE...THIS PATTERN WOULD BRING EAST TO SOUTHEAST FLOW...CAPABLE TO
PRODUCE DOWNSLOPING WARMING ACROSS THE LOWLANDS SUNDAY NIGHT.
INCREASED FEW DEGREES FROM HPC GUIDANCE ACCORDINGLY.
FOR MONDAY...BUFKIT SOUNDINGS SHOW DRY AIR ALOFT WITH LIMITED
MOISTURE IN THE VERY LOW LEVELS WHILE A H500 WEAK SHORTWAVE CROSSES
THE AREA. KEPT LOW CHANCE POPS WITH THIS FEATURE...MORE ALONG THE
GFS SOLUTION. THE ECMWF BRINGS STRONG COLD AIR ADVECTION FOR THE
SAME TIME PERIOD WITH SUCH A WEAK WAVE. BELIEVE ECMWF IS OVERDOING
CAA SO PREFERRED THE GFS.
BY MONDAY NIGHT FLOW IN THE LOW LEVELS TURN NORTHWEST WITH SOME CAA
FROM BOTH MODELS. FIGURE A GOOD SET UP FOR UPSLOPE PCPN. THE GFS
BRINGS THE 0C LEVEL AROUND THE NORTHEAST MOUNTAINS WHILE IN THE
ECMWF...THE 0C LINE GOES WAY SOUTH OF THE AREA. WENT WITH A BLEND
SOLUTION EXPECTING CHANCE POPS WITH FEW SNOW SHOWERS OR MIX PCPN
OVER THE MOST FAVORABLE UPSLOPE AREAS...AND RAIN ELSEWHERE. PCPN IS
EXPECTED TO TAMPER OFF ON TUESDAY KEEPING CHANCE POPS OVER THE
EASTERN MOUNTAINS ESPECIALLY WITH THE UPSLOPE COMPONENT AND DRY
WEATHER SPREADING FROM SOUTHEAST OH...EAST.
DRY WEATHER EXPECTED THROUGH THE REST OF THE PERIOD AS A HIGH
PRESSURE BUILDS IN.
WENT CLOSE TO HPC TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AN UPPER LEVEL SYSTEM COMBINED WITH A WARM FRONTAL BOUNDARY WILL
ALLOW PRECIP TO OVERSPREAD MOST OF THE AREA THRU THE EVENING. THIS
WILL MAINLY BE IN THE FORM OF RA...SAVE FOR A BRIEF PERIOD OF
PL POSSIBLY ON THE FRONT END OF THE PRECIP THIS AFTERNOON. EXPECT
VSBY TO LOWER INTO MVFR AS THE PRECIP MOVES ALONG WITH A GRADUAL
LOWERING OF CIGS INTO MVFR HEADING INTO THIS EVENING.
ONCE THIS UPPER LEVEL SYSTEM PASSES...EXPECT A SHRA REGIME TO TAKE
HOLD WITH A WARM FRONTAL BOUNDARY LINGERING. AGAIN...RA EXPECTED
TO BE DOMINATE PRECIP TYPE AT ALL TAF SITES. SOME FRZ RA OR PL
MIXTURE IS EXPECTED IN THE N MOUNTAINS THIS EVENING. CIGS AND VSBY
EXPECTED TO LOWER INTO IFR TONIGHT FOR MOST TAF SITES WITH EKN
HOLDING OUT THE LONGEST.
A SFC LOW WILL ORGANIZE OVER TN VALLEY...WITH ANOTHER WARM FRONT
DEVELOPING INTO THE REGION FOR FRIDAY. THIS WILL INCREASE THE
COVERAGE OF PRECIP ONCE AGAIN...WITH MOST OF THE RA N AND W OF A
HTS/CRW/CKB LINE. CONDITIONS SHOULD IMPROVE FOR KCRW AND PERHAPS
KBKW ONCE INTO THE WARM SECTOR WHILE IFR CONDITIONS IN RA PERSIST
ELSEWHERE.
SFC FLOW WILL BE LIGHT AND VARIABLE...MAINLY FROM THE E. LIGHT W
FLOW ALOFT WILL BECOME LIGHT SW TONIGHT...INCREASING A BIT TOWARD
DAWN FRI.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS IN RAIN
MAY VARY OVERNIGHT TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H M M H H H
HTS CONSISTENCY H H M M H H H H H H H H
BKW CONSISTENCY H H H M M H H H H H M M
EKN CONSISTENCY H H H H H H H H H M M H
PKB CONSISTENCY H H H H H H H H H H H M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z FRIDAY...
IFR POSSIBLE OVERNIGHT FRIDAY INTO THE WEEKEND IN RAIN...WITH
FREEZING RAIN LIKELY IN THE NORTHERN MOUNTAINS...MAINLY E OF THE
CHEAT RIDGE...INTO FRIDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 8 PM THIS EVENING TO 11 AM EST
FRIDAY FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30/26
NEAR TERM...30
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
200 PM EST THU DEC 4 2014
.SYNOPSIS...
SERIES OF LOW PRESSURE WAVES CROSS INTO THE WEEKEND. HIGH
PRESSURE SUNDAY. COLD FRONT EARLY NEXT WEEK MAY BE FOLLOWED A BY
LONGER PERIOD OF HIGH PRESSURE.
&&
.NEAR TERM /THROUGH FRIDAY/...
PRECIP EXPANDING NE A BIT QUICKER THAN PREVIOUS FORECAST. STILL A
SIGNIFICANT DRY LAYER IN THE LOWER LAYERS TO OVERCOME...BUT
IT WONT TAKE LONG FOR THIS TO ERODE ONCE THE PRECIP MOVES IN.
EXCEPTION BEING ACROSS SE OH AND N WV WHERE THE DRY LAYER IS A BIT
MORE ROBUST. USED LATEST HRRR FOR TIMING OF HIGH POPS IN THRU THIS
AFTERNOON AND EVENING. ALSO INSERTED A BRIEF PERIOD OF SLEET MIXING IN ON
THE LEADING EDGE ACROSS NE KY/ W WV/ AND SE OH. THIS MIX CAN BE
EXPECTED IN THE N MOUNTAINS AS WELL.
ONCE THIS WAVE MOVES BY...CWA LEFT WITH WARM FRONT THIS EVENING WITH
SHRA REGIME MAINLY N HALF OF CWA. WILL WATCH FOR A SURFACE LOW TO
ORGANIZE OVER THE TN VALLEY WITH A WARM FRONT APPENDAGE DEVELOPING
INTO AREA LATE TONIGHT. THIS WILL INCREASE THE COVERAGE OF PRECIP
HEADING INTO FRIDAY AS THE WARM FRONT SLOWLY SHIFTS INTO SE OH.
THERE MAY BE AN EXTENDED LULL IN PRECIP ACROSS SW VA AND SE WV
FRIDAY WITH THESE AREAS IN WARM SECTOR.
AFTER INTERROGATING HI RES MODELS AND SREF PROBS...ELECTED NOT TO
EXPAND THE FRZ RA ADVISORY TO RANDOLPH. ASIDE FROM A BRIEF MIX
LATER THIS AFTERNOON...EXPECT BULK OF PRECIP TONIGHT TO FALL AS
RAIN. THERE COULD BE A LITTLE FRZ RA ACROSS FAR EASTERN RANDOLPH
BUT DEFINITELY NOT A COUNTY WIDE AVG. IN FACT...THERE IS CONCERN
THAT TEMPS MAY WARM ENOUGH TONIGHT FOR RAIN EVEN OVER POCAHONTAS
COUNTY. HI RES NAM IS BY FAR COOLEST OF THE MODELS...KEEPING A SUB
FRZ THIN LAYER AROUND H9. ELEVATIONS ABOVE 3 KFT SHOULD GET INTO
WARM LAYER SUCH THAT RISING TEMPS ARE EXPECTED TONIGHT. IT SHOULD
BE QUITE MILD TOMORROW IN WARM SECTOR WHERE MID TO UPPER 50S WERE
CODED UP ACROSS SW VA UP TO I64. DOWNSLOPING COMPONENT PROBABLY
ALSO SENDS EKN INTO THE LOW 50S.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
ACTIVE WEATHER IN THE SHORT TERM PERIOD. WARM FRONTAL BOUNDARY WILL
LIFT NORTH ACROSS THE AREA ON FRIDAY. WITH COLDER AIR EXPECTED TO BE
AT THE SURFACE ALONG THE HIGHER TERRAIN...AND THE WARMER AIR MOVING
IN ALOFT...THIS WILL SET UP A SCENARIO OF LIGHT FREEZING RAIN EARLY
FRIDAY ACROSS NORTHERN MOUNTAINS. THIS WILL TAPER OFF BY LATE
MORNING/EARLY AFTERNOON...AS LOW PRESSURE WAVE MOVES INTO THE
REGION...AND WARMER AIR IS ABLE TO ERODE AWAY THE COLDER SURFACE
TEMPERATURES...EVENTUALLY CHANGING ALL PRECIP TO RAIN.
LOTS OF MOISTURE EXPECTED ACROSS THE AREA DURING THIS EVENT WITH A
GOOD TAP OF GULF MOISTURE...WITH PW VALUES PROGGED TO RISE TO AROUND
1.1 TO 1.2 INCHES. EXPECTING A DECENT SHOT OF RAIN...PARTICULARLY
ACROSS THE NORTH...WHERE LOW IS EXPECTED TO TRACK. AT THIS
POINT...EXPECTING A GENERAL 1 TO 1.3 INCHES OF QPF. AT THIS
POINT...ISSUES ON AREA WATERWAYS IS NOT EXPECTED...BUT THIS WILL
NEED TO BE MONITORED AS THE EVENT APPROACHES.
LOW WILL MOVE OFF TO THE EAST SATURDAY INTO SUNDAY...WITH GRADUALLY
DRYING WEATHER FROM WEST TO EAST AS IT DOES SO. COULD BE SOME -DZ OR
-FZDZ AT THE END OF THE EVENT AS WARMER AIR WORKS ITS WAY IN ALOFT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
GFS/ECMWF MODELS SHOW GOOD CONTINUITY WITH A SFC LOW PRESSURE
SYSTEM MOVING ACROSS OUR AREA SATURDAY. TEMPERATURES SEEMS TO BE
WARM ENOUGH FOR PCPN TO FALL IN THE FORM OF RAIN. SUBTLE DIFFERENCES
ARE EVIDENT IN THE TRAJECTORY OF THE LOW...AS THE GFS TAKES IT
NORTHEAST AND THE ECMWF TAKES IT TO OUR SOUTHEAST BY 00Z SUNDAY.
EITHER WAY...PCPN SEEMS TO LINGER SATURDAY NIGHT. OPTED TO INCREASE
POPS TO HIGH CHANCE MAINLY WESTERN SLOPES AND EASTERN MOUNTAINS
SATURDAY NIGHT AS THIS SYSTEM EXITS THE AREA. WIND FLOW WILL TURN
FROM THE NORTH BY 00Z SUNDAY...VEERING FROM THE NORTHEAST BY 12Z
SUNDAY. THIS FLOW WILL BRING COOL AND DRY AIR MASS TO THE AREA
SUNDAY AND SUNDAY NIGHT.
DIFFERENCES AMONG MODEL SOLUTIONS ARE EVIDENT STARTING AT 12Z
MONDAY...WHEN THE GFS BRINGS AN H500 HIGH AMPLITUDE WAVE ACROSS THE
MS AND OH VALLEYS WHILE THE ECMWF BRINGS A BROAD AND STRONG CLOSED
LOW DIGGING SOUTHEAST INTO OUR AREA MONDAY AND MONDAY NIGHT. CODED
SLIGHT CHANCE TO CHANCE POPS WITH THIS FEATURE FOR NOW...AWAITING
FOR BETTER CONSENSUS IN THE NEXT MODEL RUNS. AGAIN...MOST OF THE
PCPN IS EXPECTED TO BE LIQUID...EXCEPT FOR THE DEEPER HOLLOWS
NORTHEAST MOUNTAINS...WHERE THERE COULD BE A WINTRY MIX OR FREEZING
RAIN.
CAA EVIDENT IN H850 LEVEL WITH A MINUS 5C LINE CROSSING OUR NORTHERN
SECTIONS AND EASTERN MOUNTAINS BY 18Z TUESDAY. THEREFORE...CODED
UPSLOPE SNOW SHOWERS OVER NORTHEAST MOUNTAINS. THE REST OF THE AREA
SHOULD REMAIN DRY.
WENT CLOSE TO HPC TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AN UPPER LEVEL SYSTEM COMBINED WITH A WARM FRONTAL BOUNDARY WILL
ALLOW PRECIP TO OVERSPREAD MOST OF THE AREA THRU THE EVENING. THIS
WILL MAINLY BE IN THE FORM OF RA...SAVE FOR A BRIEF PERIOD OF
PL POSSIBLY ON THE FRONT END OF THE PRECIP THIS AFTERNOON. EXPECT
VSBY TO LOWER INTO MVFR AS THE PRECIP MOVES ALONG WITH A GRADUAL
LOWERING OF CIGS INTO MVFR HEADING INTO THIS EVENING.
ONCE THIS UPPER LEVEL SYSTEM PASSES...EXPECT A SHRA REGIME TO TAKE
HOLD WITH A WARM FRONTAL BOUNDARY LINGERING. AGAIN...RA EXPECTED
TO BE DOMINATE PRECIP TYPE AT ALL TAF SITES. SOME FRZ RA OR PL
MIXTURE IS EXPECTED IN THE N MOUNTAINS THIS EVENING. CIGS AND VSBY
EXPECTED TO LOWER INTO IFR TONIGHT FOR MOST TAF SITES WITH EKN
HOLDING OUT THE LONGEST.
A SFC LOW WILL ORGANIZE OVER TN VALLEY...WITH ANOTHER WARM FRONT
DEVELOPING INTO THE REGION FOR FRIDAY. THIS WILL INCREASE THE
COVERAGE OF PRECIP ONCE AGAIN...WITH MOST OF THE RA N AND W OF A
HTS/CRW/CKB LINE. CONDITIONS SHOULD IMPROVE FOR KCRW AND PERHAPS
KBKW ONCE INTO THE WARM SECTOR WHILE IFR CONDITIONS IN RA PERSIST
ELSEWHERE.
SFC FLOW WILL BE LIGHT AND VARIABLE...MAINLY FROM THE E. LIGHT W
FLOW ALOFT WILL BECOME LIGHT SW TONIGHT...INCREASING A BIT TOWARD
DAWN FRI.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS IN RAIN
MAY VARY OVERNIGHT TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H M M H H H
HTS CONSISTENCY H H M M H H H H H H H H
BKW CONSISTENCY H H H M M H H H H H M M
EKN CONSISTENCY H H H H H H H H H M M H
PKB CONSISTENCY H H H H H H H H H H H M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z FRIDAY...
IFR POSSIBLE OVERNIGHT FRIDAY INTO THE WEEKEND IN RAIN...WITH
FREEZING RAIN LIKELY IN THE NORTHERN MOUNTAINS...MAINLY E OF THE
CHEAT RIDGE...INTO FRIDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 8 PM THIS EVENING TO 11 AM EST
FRIDAY FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30/26
NEAR TERM...30
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1021 AM EST THU DEC 4 2014
.SYNOPSIS...
HIGH PRESSURE EXITS TODAY. SERIES OF LOW PRESSURE WAVES CROSS LATE
TODAY INTO THE WEEKEND. HIGH PRESSURE SUNDAY. COLD FRONT EARLY
NEXT WEEK MAY BE FOLLOWED A BY LONGER PERIOD OF HIGH PRESSURE.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...
PRECIP EXPANDING NE A BIT QUICKER THAN PREVIOUS FORECAST. STILL A
SIGNIFICANT DRY LAYER IN THE LOWER LAYERS TO OVERCOME...BUT
UPSTREAM OBS OVER KY REVEAL IT WONT TAKE LONG FOR THIS TO ERODE
ONCE THE PRECIP MOVES IN. EXCEPTION BEING ACROSS SE OH AND N WV WHERE
THE DRY LAYER IS A BIT MORE ROBUST. USED LATEST HRRR FOR TIMING OF
HIGH POPS IN THRU THIS AFTERNOON. ALSO INSERTED A BRIEF PERIOD OF
SLEET MIXING IN ON THE LEADING EDGE ACROSS NE KY/ W WV/ AND SE OH.
PREV DISCN...
HIGH PRESSURE OVER THE GREAT LAKES AND OHIO VALLEY THIS MORNING
SCOOTS ENEWD TO THE NERN CONUS BY THIS EVENING. THIS QUICK MOVER IS
ASSOCIATED WITH A LARGE AREA OF BONE DRY AIR FROM H85 TO H4. ITS
QUICK EXODUS ALLOWS THE FIRST OF A SERIES OF WAVES OF LOW
PRESSURE...EACH PRECEDED BY ISENTROPIC LIFT.
ISENTROPIC LIFT ARRIVES/COMMENCES 15-18Z TODAY...BUT IT MAY TAKE A
BIT LONGER TO SATURATE THE DRY MID LEVELS...ESPECIALLY N...AND THERE
MAY BE A SHARP NRN CUTOFF AS A RESULT. ISENTROPIC SURFACES SHOW
THAT WE SHOULD BE IN A WARM WEDGE BY FRI MORNING. BENEATH RIDGING
ALOFT...THE PATTERN STARTS TO BECOME A BIT MUDDLED BY THEN BEFORE
THE NEXT WAVE APPROACHES. HAVE RAIN ONLY SLOWLY WANING IN THE W.
THE HIGH SLOWS DOWN A BIT...EASING OFF THE NEW ENGLAND COAST ON
FRI. THIS DRIVES THE CAD LATE TONIGHT INTO FRI AS AGEOSTROPHIC
WINDS INCREASE THERE TONIGHT AND PERSIST ON FRI...GIVING RISE TO
ANOTHER FREEZING RAIN THREAT. THE START TIME WILL DEPEND UPON HOW
SLOWLY DEW POINTS RISE TONIGHT AND THE WET BULB PROCESSES THE
PRECIPITATION BEGINS THIS EVENING...OPTED FOR 8 PM WHEN POPS REACH
LIKELY.
HIGHS WERE LOWERED TODAY ON ACCOUNT OF THE FASTER TIMING OF THE
SYSTEM AND ITS ASSOCIATED INCREASE IN CLOUD AND ONSET OF RAIN.
BLENDED IN THE BIAS CORRECTED VERSIONS OF THE ECMWF AND THE MET.
BLENDED IN THE NAM AND MET FOR NON DIURNAL TEMPERATURES TONIGHT
WHICH DID NOT ENTAIL MUCH CHANGE AT ALL FROM THE PREVIOUS FCST.
THIS IS ON THE LOWER SIDE GUIDANCE OVERALL AND CLOSER TO RAW BLENDS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
ACTIVE WEATHER IN THE SHORT TERM PERIOD. WARM FRONTAL BOUNDARY WILL
LIFT NORTH ACROSS THE AREA ON FRIDAY. WITH COLDER AIR EXPECTED TO BE
AT THE SURFACE ALONG THE HIGHER TERRAIN...AND THE WARMER AIR MOVING
IN ALOFT...THIS WILL SET UP A SCENARIO OF LIGHT FREEZING RAIN EARLY
FRIDAY ACROSS NORTHERN MOUNTAINS. THIS WILL TAPER OFF BY LATE
MORNING/EARLY AFTERNOON...AS LOW PRESSURE WAVE MOVES INTO THE
REGION...AND WARMER AIR IS ABLE TO ERODE AWAY THE COLDER SURFACE
TEMPERATURES...EVENTUALLY CHANGING ALL PRECIP TO RAIN.
LOTS OF MOISTURE EXPECTED ACROSS THE AREA DURING THIS EVENT WITH A
GOOD TAP OF GULF MOISTURE...WITH PW VALUES PROGGED TO RISE TO AROUND
1.1 TO 1.2 INCHES. EXPECTING A DECENT SHOT OF RAIN...PARTICULARLY
ACROSS THE NORTH...WHERE LOW IS EXPECTED TO TRACK. AT THIS
POINT...EXPECTING A GENERAL 1 TO 1.3 INCHES OF QPF. AT THIS
POINT...ISSUES ON AREA WATERWAYS IS NOT EXPECTED...BUT THIS WILL
NEED TO BE MONITORED AS THE EVENT APPROACHES.
LOW WILL MOVE OFF TO THE EAST SATURDAY INTO SUNDAY...WITH GRADUALLY
DRYING WEATHER FROM WEST TO EAST AS IT DOES SO. COULD BE SOME -DZ OR
-FZDZ AT THE END OF THE EVENT AS WARMER AIR WORKS ITS WAY IN ALOFT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GFS/ECMWF MODELS SHOW GOOD CONTINUITY WITH A SFC LOW PRESSURE
SYSTEM MOVING ACROSS OUR AREA SATURDAY. TEMPERATURES SEEMS TO BE
WARM ENOUGH FOR PCPN TO FALL IN THE FORM OF RAIN. SUBTLE DIFFERENCES
ARE EVIDENT IN THE TRAJECTORY OF THE LOW...AS THE GFS TAKES IT
NORTHEAST AND THE ECMWF TAKES IT TO OUR SOUTHEAST BY 00Z SUNDAY.
EITHER WAY...PCPN SEEMS TO LINGER SATURDAY NIGHT. OPTED TO INCREASE
POPS TO HIGH CHANCE MAINLY WESTERN SLOPES AND EASTERN MOUNTAINS
SATURDAY NIGHT AS THIS SYSTEM EXITS THE AREA. WIND FLOW WILL TURN
FROM THE NORTH BY 00Z SUNDAY...VEERING FROM THE NORTHEAST BY 12Z
SUNDAY. THIS FLOW WILL BRING COOL AND DRY AIR MASS TO THE AREA
SUNDAY AND SUNDAY NIGHT.
DIFFERENCES AMONG MODEL SOLUTIONS ARE EVIDENT STARTING AT 12Z
MONDAY...WHEN THE GFS BRINGS AN H500 HIGH AMPLITUDE WAVE ACROSS THE
MS AND OH VALLEYS WHILE THE ECMWF BRINGS A BROAD AND STRONG CLOSED
LOW DIGGING SOUTHEAST INTO OUR AREA MONDAY AND MONDAY NIGHT. CODED
SLIGHT CHANCE TO CHANCE POPS WITH THIS FEATURE FOR NOW...AWAITING
FOR BETTER CONSENSUS IN THE NEXT MODEL RUNS. AGAIN...MOST OF THE
PCPN IS EXPECTED TO BE LIQUID...EXCEPT FOR THE DEEPER HOLLOWS
NORTHEAST MOUNTAINS...WHERE THERE COULD BE A WINTRY MIX OR FREEZING
RAIN.
CAA EVIDENT IN H850 LEVEL WITH A MINUS 5C LINE CROSSING OUR NORTHERN
SECTIONS AND EASTERN MOUNTAINS BY 18Z TUESDAY. THEREFORE...CODED
UPSLOPE SNOW SHOWERS OVER NORTHEAST MOUNTAINS. THE REST OF THE AREA
SHOULD REMAIN DRY.
WENT CLOSE TO HPC TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE DAY DAWNS WITH HIGH IFR TO MVFR STRATOCU SE SITES...INCLUDING
CRW...EKN AND BKW...AND MVFR MIST NW SITES WHERE IT HAD CLEARED
OVERNIGHT...INCLUDING HTS...PKB AND CKB. BOTH SHOULD BE GONE BY 15Z
ALTHOUGH MVFR MORNING MAY FORM FOR AN HOUR OR TWO WHERE IT CLEARED.
A LOW PRESSURE SYSTEM APPROACHING FROM THE W WILL BRING LOWERING
AND THICKENING CLOUDS TODAY. CIGS SHOULD LOWER TO MVFR BY 00Z FRI
ACROSS SRN WV...ERN KY AND SW VA AND INCLUDING HTS AND BKW AND THEN
CRW. MVFR CIGS SPREAD AREA WIDE BY 06Z FRI...AND LOWER TO IFR IN
THE MOUNTAINS AND IN THE MIDDLE OHIO VALLEY 06-12Z FRI. VSBY WITH
THE RAIN LATE TODAY AND TONIGHT WILL BE MAINLY MVFR AND MAINLY S AND
E OF THE OHIO RIVER. IFR VSBY IN RAIN IS MOST LIKELY IN THE
MOUNTAINS TONIGHT. FREEZING RAIN IS LIKELY OVERNIGHT TONIGHT IN THE
MOUNTAINS E OF THE CHEAT RIDGE...INCLUDING THE GREENBRIER VALLEY.
SFC FLOW WILL BE LIGHT AND VARIABLE...MAINLY FROM THE E. LIGHT W
FLOW ALOFT WILL BECOME LIGHT SW TONIGHT...INCREASING A BIT TOWARD
DAWN FRI.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OR ERADICATION OF MVFR VSBYS AND CIGS
THIS MORNING MAY VARY...AS MAY ONSET OF MVFR RAIN LATER TODAY AND
TONIGHT. TIMING AND EXTENT OF IFR CONDITIONS IN RAIN MAY VARY
OVERNIGHT TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY M H H H H H H H H H H M
HTS CONSISTENCY H H M M H H M M M M M M
BKW CONSISTENCY H H H H H H H H M M M H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z FRIDAY...
IFR POSSIBLE OVERNIGHT FRIDAY INTO THE WEEKEND IN RAIN...WITH
FREEZING RAIN LIKELY IN THE NORTHERN MOUNTAINS...MAINLY E OF THE
CHEAT RIDGE...INTO FRIDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 8 PM THIS EVENING TO 11 AM EST
FRIDAY FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/LS
NEAR TERM...TRM/30
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
944 AM EST THU DEC 4 2014
.SYNOPSIS...
AN AREA OF RAIN IS EXPECTED TO MOVE INTO THE REGION TODAY...AS A
WARM FRONT GRADUALLY DEVELOPS NEAR THE OHIO RIVER. A MORE POTENT
AREA OF LOW PRESSURE WILL MOVE ACROSS THE OHIO VALLEY ON FRIDAY
AND INTO SATURDAY...WITH RAIN EXPECTED THROUGH SATURDAY AFTERNOON.
AN AREA OF HIGH PRESSURE WILL ALLOW FOR DRIER AND COOLER
CONDITIONS ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRECIPITATION HAS SPREAD INTO NORTHERN KENTUCKY AND WILL CONTINUE
TO SLIDE EAST. MEASURABLE PRECIPITATION SHOULD MAKE IT A BIT
FURTHER NORTH THAN WHAT IS CURRENTLY OCCURRING. BUT FOR THE MOST
PART IT SHOULD REMAIN CONFINED TO AREAS ALONG AND SOUTH OF THE
OHIO RIVER. HAVE NOT GOTTEN ANY REPORTS THUS FAR...BUT HRRR AND
RAP SOUNDINGS CONTINUE TO SHOW THE POSSIBILITY OF SOME SLEET OR
EVEN SNOW MIXING IN ALONG THE NORTHERN EDGE OF THE PRECIPITATION.
BUT FOR THE MOST PART THIS WILL BE A RAIN EVENT WITH AMOUNTS LESS
THAN 1/4 INCH. EXPECT PRECIPITATION TO START DIMINISHING THE WEST
LATE IN THE DAY ALTHOUGH SOME LINGERING SPOTTY RAIN CANNOT BE
COMPLETELY RULED OUT. PRECIPITATION AND EXTENSIVE CLOUD COVER
SHOULD RESULT IN A VERY SLOW TEMPERATURE RISE. AND HAVE OPTED TO
LOWER HIGHS A FEW DEGREES EVEN IN NORTHERN COUNTIES THAT WILL
REMAIN DRY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ATTENTION FOR THE NEXT FEW DAYS WILL TURN TO THE RAIN EXPECTED
ACROSS THE ENTIRE FORECAST AREA FROM FRIDAY THROUGH SATURDAY. A
WELL-DEFINED AND MODERATELY STRONG 500MB SHORTWAVE WILL BE MOVING
EAST ACROSS THE MISSISSIPPI VALLEY BY FRIDAY NIGHT...CLEARING
THROUGH THE OHIO VALLEY BY SATURDAY EVENING. THE REFLECTION OF
THIS TROUGH LOWER IN THE ATMOSPHERE IS ACTUALLY EVEN
SHARPER...WITH A CLOSED LOW SHOWING UP AT THE SURFACE AND AT
925MB. THIS SYSTEM WILL HAVE A MUCH MORE IMPRESSIVE CONNECTION
TO DEEP GULF MOISTURE THAN HAS BEEN IN PLACE FOR QUITE A WHILE.
ALTHOUGH SOME LIGHT PRECIPITATION IS EXPECTED TO GRADUALLY SPREAD
NORTH THROUGH THE FORECAST AREA TONIGHT AND INTO EARLY FRIDAY
MORNING...THE MAJORITY OF THE RAIN IS EXPECTED TO MOVE INTO THE
SOUTHWESTERN CWA BY 18Z FRIDAY. BY LATE FRIDAY...PRECIPITABLE
WATER VALUES OF OVER AN INCH WILL ADVECT INTO THE ILN FORECAST
AREA...WELL ABOVE CLIMATOLOGICAL NORMALS FOR DECEMBER.
THE 00Z MODELS TONIGHT HAVE MADE A SLIGHT SHIFT NORTHWARD WITH THE
TRACK OF THE SURFACE LOW...AND THUS THE AREA OF GREATEST PROLONGED
LOW-LEVEL CONVERGENCE ALONG THE DEVELOPING FRONTAL STRUCTURE. TO
NO SURPRISE...THE QPF AXIS DEPICTED ON THE VARIOUS MODEL SOLUTIONS
HAS SHIFTED A LITTLE MORE SOLIDLY ACROSS THE ILN FORECAST
AREA...AND RAINFALL AMOUNTS OF OVER AN INCH LOOK VERY LIKELY. A
FEW SPOTS RECEIVING UP TO TWO INCHES MAY OCCUR. DESPITE
THIS...THE FLOODING THREAT APPEARS RELATIVELY MINIMAL. BASED ON
OHRFC MMEFS GUIDANCE...RIVERS (WHICH ARE RUNNING FAIRLY LOW AT THE
MOMENT) DO NOT SHOW A HIGH PROBABILITY FOR FLOODING. A WIDESPREAD
1.0-1.5 INCH RAIN OVER ABOUT 24 HOURS IS ALSO PROBABLY NOT ENOUGH
FOR GENERAL NON-RIVER FLOOD CONCERNS.
THE AMERICAN MODELS (GFS/NAM) REMAIN ON THE FAST SIDE OF THE
GUIDANCE ENVELOPE FOR THE EVENTUAL DEPARTURE OF PRECIPITATION ON
SATURDAY. THE ECMWF/GEM MAINTAIN THE SLOWER END OF THE
PROGRESSION...WITH DEEPER DEPICTIONS OF THE 500MB TROUGH.
WITH A SIGNIFICANT TEMPERATURE GRADIENT EXPECTED TO DEVELOP OVER
THE AREA...ADVECTION-BASED NON-DIURNAL TEMPERATURE TRENDS WERE
USED IN THE GRIDS...CONFIDENCE IN EXACT NUMBERS IS NOT
PARTICULARLY HIGH. PRECIPITATION DOES APPEAR LIKELY TO END BEFORE
TEMPERATURES ARE COLD ENOUGH TO SUPPORT ANYTHING BUT RAIN...BUT
WITH THE SURFACE FRONT BEGINNING ITS SOUTHWARD MOTION EARLY
SATURDAY MORNING...FALLING TEMPERATURES ARE LIKELY ON SATURDAY.
UNDER DRY CONDITIONS...TEMPERATURES WILL END UP WITHIN A FEW
DEGREES EITHER SIDE OF THE FREEZING MARK ON SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
WHILE COLD ADVECTION WILL PERSIST ON SUNDAY...CLEARER SKIES WILL
ALLOW FOR SOME TEMPERATURES TO REACH NEAR OR SLIGHTLY ABOVE CLIMO.
RAIN SHOWERS MONDAY WILL MIX WITH SNOW OVERNIGHT BEFORE ENDING.
THE HIGH WILL REMAIN WELL N OF THE OHIO VALLEY BUT THE AXIS SHOULD
CROSS SUNDAY NIGHT AND SIGNIFY A SWITCH TO SOUTHERLY AND WARMING
FLOW...IF ONLY SLIGHTLY WARMER. ANOTHER COLD FRONT WILL CROSS MONDAY
NIGHT AND TUESDAY WILL BE CLOUDY AND COOL WITH READINGS IN THE 30S.
HIGH PRESSURE WILL THEN POOL NW OF THE REGION FOR THE MIDDLE OF NEXT
WEEK AND BRING MORE NORMAL TEMPERATURES WITH A DRY PATTERN.
MODELS DIVERGE SIGNIFICANTLY MONDAY NIGHT AND FCST IS IN A HIGHER
STATE OF UNCERTAINTY BEYOND THIS TIME.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
SEVERAL TAF SITES WILL EXPERIENCE MAINLY MVFR VISIBILITIES THIS
MORNING. FOR LATER TODAY...AN UPPER LEVEL DISTURBANCE ALONG WITH
AN INCREASING LOW LEVEL JET WILL RESULT IN RAIN DEVELOPMENT TO OUR
SOUTHWEST. THIS RAIN SHIELD WILL EVENTUALLY PUSH NORTHEAST TOWARD
THE OHIO RIVER BY 18Z. KCVG AND KLUK HAVE THE BEST CHANCE TO SEE
RAIN WHERE FORCING WILL BE THE GREATEST. THE RAIN THREAT WILL
DECREASE APPRECIABLY NORTH OF KILN TAF SITE. CEILINGS SHOULD
REMAIN VFR WITH PERHAPS A REDUCTION TO MVFR VISIBILITIES AT
KCVG/KLUK. IT SHOULD BE NOTED THAT THERE MAY BE A BRIEF PERIOD OF
LIGHT SLEET AT THE ONSET OF THE PCPN DUE TO THE INITIALLY DRY LOW
LEVELS AND A LITTLE BIT OF WARM AIR ALOFT TO ALLOW PARTIAL MELTING
OF LIGHT PRECIPITATION. THIS THREAT APPEARS LOW ENOUGH TO NOT
MENTION IN THE TAFS ATTM.
FOR TONIGHT...UPPER LEVEL DISTURBANCE MOVES EAST AND THE LOW LEVEL
JET BRIEFLY WEAKENS EARLY ON. DURING THE LATER PART OF THE NIGHT
INTO FRIDAY MORNING...A WARM...MOIST PUSH IS FORECAST TO OCCUR AND
MOVE NORTHEAST THROUGH THE REGION OVERNIGHT. THE LOW LEVELS WILL
CONTINUE TO SATURATE...RESULTING IN CEILINGS DROPPING INTO THE IFR
CATEGORY WITH VISIBILITIES AT LEAST DROPPING INTO THE MVFR
CATEGORY. THE WEAK ASCENT AND SATURATED LOW LEVELS WILL BRING A
THREAT FOR EITHER DRIZZLE OR LIGHT RAIN...ESPECIALLY BETWEEN 06Z
AND 12Z.
OUTLOOK...IFR/LIFR CEILINGS AND VISIBILITIES LIKELY FRIDAY INTO
FRIDAY NIGHT. MVFR/IFR CEILINGS AND MVFR VISIBILITIES EXPECTED TO
LINGER INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...FRANKS
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
606 AM EST THU DEC 4 2014
.SYNOPSIS...
AN AREA OF RAIN IS EXPECTED TO MOVE INTO THE REGION TODAY...AS A
WARM FRONT GRADUALLY DEVELOPS NEAR THE OHIO RIVER. A MORE POTENT
AREA OF LOW PRESSURE WILL MOVE ACROSS THE OHIO VALLEY ON FRIDAY
AND INTO SATURDAY...WITH RAIN EXPECTED THROUGH SATURDAY AFTERNOON.
AN AREA OF HIGH PRESSURE WILL ALLOW FOR DRIER AND COOLER
CONDITIONS ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SOLID CANOPY OF HIGH CLOUDS HAS OVERSPREAD THE AREA...AND
MID-LEVEL CLOUDS ARE NOW BEING OBSERVED IN FAR SOUTHERN INDIANA
AND WESTERN KENTUCKY. DESPITE THESE CLOUDS...A FEW PATCHES OF FOG
HAVE DEVELOPED...WITH JUST ENOUGH LOW-LEVEL MOISTURE TO LEAD TO
SOME HEAVY FROST. THE FOG HAS NOT BEEN PARTICULARLY DENSE (ONLY A
COUPLE OBSERVATION SITES BRIEFLY DROPPED TO 1/4 MILE)...BUT THERE
IS A CONCERN THAT WHERE FOG IS A LITTLE THICKER...SOME OF IT MAY
DEPOSIT ICE ON SURFACES. THIS WILL BE MONITORED HEADING INTO THE
NEXT FEW HOURS.
NEAR-SURFACE CONDITIONS ARE EXPECTED TO REMAIN FAIRLY COOL
TODAY...WITH EASTERLY FLOW FROM 925MB AND BELOW. HOWEVER...AT
850MB...A WARM FRONT IS ALREADY BEGINNING TO SET UP. THIS FRONT
WILL MOVE NORTH INTO THE ILN FORECAST AREA AFTER 12Z. THE FRONT IS
ALSO EXPECTED TO ACT AS A FOCUS FOR PRECIPITATION...WHICH WILL BE
AIDED BY THE PASSAGE OF A WEAK SHORTWAVE IN THE GENERALLY ZONAL
500MB FLOW. THE MAJORITY OF THIS PRECIPITATION SHOULD REMAIN SOUTH
OF THE OHIO RIVER...BUT LIGHT ACTIVITY IS EXPECTED TO BE POSSIBLE
THROUGH AT LEAST THE SOUTHERN HALF OF THE FORECAST AREA BY LATE
MORNING / EARLY AFTERNOON.
THERE REMAINS SOME SLIGHT CONCERN REGARDING PRECIPITATION
TYPE...AS SURFACE TEMPERATURES WILL BE STARTING OFF IN THE LOWER
30S AND UPPER 20S...AND THE LAYER OF WARM AIR ALOFT IS NOT QUITE
BEING TIMED OUT WITH EXACT CONSISTENCY FROM MODEL TO MODEL. IT
DOES APPEAR LIKELY THAT SURFACE TEMPS WILL BE RISING ABOVE
FREEZING BEFORE PRECIPITATION BEGINS...THOUGH IF THERE IS ANY
CHANCE OF A BRIEF PERIOD OF FREEZING RAIN...IT COULD OCCUR IN
SOUTHEAST INDIANA IN THE 12Z-15Z TIME PERIOD. IT APPEARS THAT THE
MORE LIKELY SCENARIO WILL BE FOR PRECIPITATION BEGINNING JUST AS
THE 925MB-800MB IS IN THE PROCESS OF WARMING ABOVE FREEZING. WITH
SOME SATURATION NEAR THE SURFACE STILL NEEDING TO OCCUR...THIS
TEMPERATURE PROFILE WOULD SUPPORT A BRIEF MIX OF SLEET AND
RAIN...BEFORE THE ENTIRE SOUNDING BELOW 800MB ENDS UP ABOVE
FREEZING. THIS COULD OCCUR AT TWO DIFFERENT TIMES IN THE FORECAST.
THE FIRST OCCURRENCE WOULD BE AS THE INITIAL AREA OF PRECIPITATION
MOVES INTO THE SOUTHWESTERN QUADRANT OF THE FORECAST AREA THIS
MORNING. HRRR AND 4KM WRF OUTPUT DOES SUGGEST THAT THERE WILL BE
VIRGA IN ADVANCE OF SURFACE PRECIPITATION (WITH SIMULATED COMP
REFLECTIVITY SHOWING A GREATER AREAL EXPANSE THAN SIMULATED 1KM
REFLECTIVITY). AS IS SOMETIMES OBSERVED IN THESE SITUATIONS...THE
FIRST HYDROMETEORS TO HIT THE GROUND MAY BE PELLETS.
THE SECOND POSSIBLE OCCURRENCE OF SLEET WOULD BE AS LIGHT
PRECIPITATION EXPANDS NORTHWARD THIS EVENING...AFFECTING THE
NORTHERN HALF OF THE FORECAST AREA. REGARDLESS...WITH SLEET ONLY
LIKELY TO OCCUR FOR A BRIEF PERIOD OF TIME NEAR THE ONSET OF
PRECIPITATION...MEASURABLE ACCUMULATIONS ARE UNLIKELY.
POPS FOR TODAY FOCUS ON THE SOUTHERN THIRD OF THE FORECAST
AREA...WHERE RAIN NOW APPEARS TO BE A CERTAINTY. SURFACE
TEMPERATURES ARE EXPECTED TO REACH THE UPPER 30S TO LOWER
40S...BUT THERE IS SOME CHANCE THAT PRECIPITATION COULD HOLD THESE
VALUES DOWN A FEW DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ATTENTION FOR THE NEXT FEW DAYS WILL TURN TO THE RAIN EXPECTED
ACROSS THE ENTIRE FORECAST AREA FROM FRIDAY THROUGH SATURDAY. A
WELL-DEFINED AND MODERATELY STRONG 500MB SHORTWAVE WILL BE MOVING
EAST ACROSS THE MISSISSIPPI VALLEY BY FRIDAY NIGHT...CLEARING
THROUGH THE OHIO VALLEY BY SATURDAY EVENING. THE REFLECTION OF
THIS TROUGH LOWER IN THE ATMOSPHERE IS ACTUALLY EVEN
SHARPER...WITH A CLOSED LOW SHOWING UP AT THE SURFACE AND AT
925MB. THIS SYSTEM WILL HAVE A MUCH MORE IMPRESSIVE CONNECTION
TO DEEP GULF MOISTURE THAN HAS BEEN IN PLACE FOR QUITE A WHILE.
ALTHOUGH SOME LIGHT PRECIPITATION IS EXPECTED TO GRADUALLY SPREAD
NORTH THROUGH THE FORECAST AREA TONIGHT AND INTO EARLY FRIDAY
MORNING...THE MAJORITY OF THE RAIN IS EXPECTED TO MOVE INTO THE
SOUTHWESTERN CWA BY 18Z FRIDAY. BY LATE FRIDAY...PRECIPITABLE
WATER VALUES OF OVER AN INCH WILL ADVECT INTO THE ILN FORECAST
AREA...WELL ABOVE CLIMATOLOGICAL NORMALS FOR DECEMBER.
THE 00Z MODELS TONIGHT HAVE MADE A SLIGHT SHIFT NORTHWARD WITH THE
TRACK OF THE SURFACE LOW...AND THUS THE AREA OF GREATEST PROLONGED
LOW-LEVEL CONVERGENCE ALONG THE DEVELOPING FRONTAL STRUCTURE. TO
NO SURPRISE...THE QPF AXIS DEPICTED ON THE VARIOUS MODEL SOLUTIONS
HAS SHIFTED A LITTLE MORE SOLIDLY ACROSS THE ILN FORECAST
AREA...AND RAINFALL AMOUNTS OF OVER AN INCH LOOK VERY LIKELY. A
FEW SPOTS RECEIVING UP TO TWO INCHES MAY OCCUR. DESPITE
THIS...THE FLOODING THREAT APPEARS RELATIVELY MINIMAL. BASED ON
OHRFC MMEFS GUIDANCE...RIVERS (WHICH ARE RUNNING FAIRLY LOW AT THE
MOMENT) DO NOT SHOW A HIGH PROBABILITY FOR FLOODING. A WIDESPREAD
1.0-1.5 INCH RAIN OVER ABOUT 24 HOURS IS ALSO PROBABLY NOT ENOUGH
FOR GENERAL NON-RIVER FLOOD CONCERNS.
THE AMERICAN MODELS (GFS/NAM) REMAIN ON THE FAST SIDE OF THE
GUIDANCE ENVELOPE FOR THE EVENTUAL DEPARTURE OF PRECIPITATION ON
SATURDAY. THE ECMWF/GEM MAINTAIN THE SLOWER END OF THE
PROGRESSION...WITH DEEPER DEPICTIONS OF THE 500MB TROUGH.
WITH A SIGNIFICANT TEMPERATURE GRADIENT EXPECTED TO DEVELOP OVER
THE AREA...ADVECTION-BASED NON-DIURNAL TEMPERATURE TRENDS WERE
USED IN THE GRIDS...CONFIDENCE IN EXACT NUMBERS IS NOT
PARTICULARLY HIGH. PRECIPITATION DOES APPEAR LIKELY TO END BEFORE
TEMPERATURES ARE COLD ENOUGH TO SUPPORT ANYTHING BUT RAIN...BUT
WITH THE SURFACE FRONT BEGINNING ITS SOUTHWARD MOTION EARLY
SATURDAY MORNING...FALLING TEMPERATURES ARE LIKELY ON SATURDAY.
UNDER DRY CONDITIONS...TEMPERATURES WILL END UP WITHIN A FEW
DEGREES EITHER SIDE OF THE FREEZING MARK ON SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
WHILE COLD ADVECTION WILL PERSIST ON SUNDAY...CLEARER SKIES WILL
ALLOW FOR SOME TEMPERATURES TO REACH NEAR OR SLIGHTLY ABOVE CLIMO.
RAIN SHOWERS MONDAY WILL MIX WITH SNOW OVERNIGHT BEFORE ENDING.
THE HIGH WILL REMAIN WELL N OF THE OHIO VALLEY BUT THE AXIS SHOULD
CROSS SUNDAY NIGHT AND SIGNIFY A SWITCH TO SOUTHERLY AND WARMING
FLOW...IF ONLY SLIGHTLY WARMER. ANOTHER COLD FRONT WILL CROSS MONDAY
NIGHT AND TUESDAY WILL BE CLOUDY AND COOL WITH READINGS IN THE 30S.
HIGH PRESSURE WILL THEN POOL NW OF THE REGION FOR THE MIDDLE OF NEXT
WEEK AND BRING MORE NORMAL TEMPERATURES WITH A DRY PATTERN.
MODELS DIVERGE SIGNIFICANTLY MONDAY NIGHT AND FCST IS IN A HIGHER
STATE OF UNCERTAINTY BEYOND THIS TIME.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
SEVERAL TAF SITES WILL EXPERIENCE MAINLY MVFR VISIBILITIES FOR
ABOUT A COUPLE OF HOURS THIS MORNING. THICKENING CLOUDS AND WINDS
PICKING UP SLIGHTLY FROM THE EAST FROM DEPARTING HIGH PRESSURE
SHOULD HELP IMPROVE THE VISIBILITIES BY 14Z.
FOR LATER TODAY...AN UPPER LEVEL DISTURBANCE ALONG WITH AN
INCREASING LOW LEVEL JET WILL RESULT IN RAIN DEVELOPMENT TO OUR
SOUTHWEST. THIS RAIN SHIELD WILL EVENTUALLY PUSH NORTHEAST TOWARD
THE OHIO RIVER BY 18Z. KCVG AND KLUK HAVE THE BEST CHANCE TO SEE
RAIN WHERE FORCING WILL BE THE GREATEST. THE RAIN THREAT WILL
DECREASE APPRECIABLY NORTH OF KILN TAF SITE. CEILINGS SHOULD
REMAIN VFR WITH PERHAPS A REDUCTION TO MVFR VISIBILITIES AT
KCVG/KLUK. IT SHOULD BE NOTED THAT THERE MAY BE A BRIEF PERIOD OF
LIGHT SLEET AT THE ONSET OF THE PCPN DUE TO THE INITIALLY DRY LOW
LEVELS AND A LITTLE BIT OF WARM AIR ALOFT TO ALLOW PARTIAL MELTING
OF LIGHT PRECIPITATION. THIS THREAT APPEARS LOW ENOUGH TO NOT
MENTION IN THE TAFS ATTM.
FOR TONIGHT...UPPER LEVEL DISTURBANCE MOVES EAST AND THE LOW LEVEL
JET BRIEFLY WEAKENS EARLY ON. DURING THE LATER PART OF THE NIGHT
INTO FRIDAY MORNING...A WARM...MOIST PUSH IS FORECAST TO OCCUR AND
MOVE NORTHEAST THROUGH THE REGION OVERNIGHT. THE LOW LEVELS WILL
CONTINUE TO SATURATE...RESULTING IN CEILINGS DROPPING INTO THE IFR
CATEGORY WITH VISIBILITIES AT LEAST DROPPING INTO THE MVFR
CATEGORY. THE WEAK ASCENT AND SATURATED LOW LEVELS WILL BRING A
THREAT FOR EITHER DRIZZLE OR LIGHT RAIN...ESPECIALLY BETWEEN 06Z
AND 12Z.
OUTLOOK...IFR/LIFR CEILINGS AND VISIBILITIES LIKELY FRIDAY INTO
FRIDAY NIGHT. MVFR/IFR CEILINGS AND MVFR VISIBILITIES EXPECTED TO
LINGER INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...FRANKS
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
601 AM EST THU DEC 4 2014
.SYNOPSIS...
AN AREA OF RAIN IS EXPECTED TO MOVE INTO THE REGION TODAY...AS A
WARM FRONT GRADUALLY DEVELOPS NEAR THE OHIO RIVER. A MORE POTENT
AREA OF LOW PRESSURE WILL MOVE ACROSS THE OHIO VALLEY ON FRIDAY
AND INTO SATURDAY...WITH RAIN EXPECTED THROUGH SATURDAY AFTERNOON.
AN AREA OF HIGH PRESSURE WILL ALLOW FOR DRIER AND COOLER
CONDITIONS ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SOLID CANOPY OF HIGH CLOUDS HAS OVERSPREAD THE AREA...AND
MID-LEVEL CLOUDS ARE NOW BEING OBSERVED IN FAR SOUTHERN INDIANA
AND WESTERN KENTUCKY. DESPITE THESE CLOUDS...A FEW PATCHES OF FOG
HAVE DEVELOPED...WITH JUST ENOUGH LOW-LEVEL MOISTURE TO LEAD TO
SOME HEAVY FROST. THE FOG HAS NOT BEEN PARTICULARLY DENSE (ONLY A
COUPLE OBSERVATION SITES BRIEFLY DROPPED TO 1/4 MILE)...BUT THERE
IS A CONCERN THAT WHERE FOG IS A LITTLE THICKER...SOME OF IT MAY
DEPOSIT ICE ON SURFACES. THIS WILL BE MONITORED HEADING INTO THE
NEXT FEW HOURS.
NEAR-SURFACE CONDITIONS ARE EXPECTED TO REMAIN FAIRLY COOL
TODAY...WITH EASTERLY FLOW FROM 925MB AND BELOW. HOWEVER...AT
850MB...A WARM FRONT IS ALREADY BEGINNING TO SET UP. THIS FRONT
WILL MOVE NORTH INTO THE ILN FORECAST AREA AFTER 12Z. THE FRONT IS
ALSO EXPECTED TO ACT AS A FOCUS FOR PRECIPITATION...WHICH WILL BE
AIDED BY THE PASSAGE OF A WEAK SHORTWAVE IN THE GENERALLY ZONAL
500MB FLOW. THE MAJORITY OF THIS PRECIPITATION SHOULD REMAIN SOUTH
OF THE OHIO RIVER...BUT LIGHT ACTIVITY IS EXPECTED TO BE POSSIBLE
THROUGH AT LEAST THE SOUTHERN HALF OF THE FORECAST AREA BY LATE
MORNING / EARLY AFTERNOON.
THERE REMAINS SOME SLIGHT CONCERN REGARDING PRECIPITATION
TYPE...AS SURFACE TEMPERATURES WILL BE STARTING OFF IN THE LOWER
30S AND UPPER 20S...AND THE LAYER OF WARM AIR ALOFT IS NOT QUITE
BEING TIMED OUT WITH EXACT CONSISTENCY FROM MODEL TO MODEL. IT
DOES APPEAR LIKELY THAT SURFACE TEMPS WILL BE RISING ABOVE
FREEZING BEFORE PRECIPITATION BEGINS...THOUGH IF THERE IS ANY
CHANCE OF A BRIEF PERIOD OF FREEZING RAIN...IT COULD OCCUR IN
SOUTHEAST INDIANA IN THE 12Z-15Z TIME PERIOD. IT APPEARS THAT THE
MORE LIKELY SCENARIO WILL BE FOR PRECIPITATION BEGINNING JUST AS
THE 925MB-800MB IS IN THE PROCESS OF WARMING ABOVE FREEZING. WITH
SOME SATURATION NEAR THE SURFACE STILL NEEDING TO OCCUR...THIS
TEMPERATURE PROFILE WOULD SUPPORT A BRIEF MIX OF SLEET AND
RAIN...BEFORE THE ENTIRE SOUNDING BELOW 800MB ENDS UP ABOVE
FREEZING. THIS COULD OCCUR AT TWO DIFFERENT TIMES IN THE FORECAST.
THE FIRST OCCURRENCE WOULD BE AS THE INITIAL AREA OF PRECIPITATION
MOVES INTO THE SOUTHWESTERN QUADRANT OF THE FORECAST AREA THIS
MORNING. HRRR AND 4KM WRF OUTPUT DOES SUGGEST THAT THERE WILL BE
VIRGA IN ADVANCE OF SURFACE PRECIPITATION (WITH SIMULATED COMP
REFLECTIVITY SHOWING A GREATER AREAL EXPANSE THAN SIMULATED 1KM
REFLECTIVITY). AS IS SOMETIMES OBSERVED IN THESE SITUATIONS...THE
FIRST HYDROMETEORS TO HIT THE GROUND MAY BE PELLETS.
THE SECOND POSSIBLE OCCURRENCE OF SLEET WOULD BE AS LIGHT
PRECIPITATION EXPANDS NORTHWARD THIS EVENING...AFFECTING THE
NORTHERN HALF OF THE FORECAST AREA. REGARDLESS...WITH SLEET ONLY
LIKELY TO OCCUR FOR A BRIEF PERIOD OF TIME NEAR THE ONSET OF
PRECIPITATION...MEASURABLE ACCUMULATIONS ARE UNLIKELY.
POPS FOR TODAY FOCUS ON THE SOUTHERN THIRD OF THE FORECAST
AREA...WHERE RAIN NOW APPEARS TO BE A CERTAINTY. SURFACE
TEMPERATURES ARE EXPECTED TO REACH THE UPPER 30S TO LOWER
40S...BUT THERE IS SOME CHANCE THAT PRECIPITATION COULD HOLD THESE
VALUES DOWN A FEW DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ATTENTION FOR THE NEXT FEW DAYS WILL TURN TO THE RAIN EXPECTED
ACROSS THE ENTIRE FORECAST AREA FROM FRIDAY THROUGH SATURDAY. A
WELL-DEFINED AND MODERATELY STRONG 500MB SHORTWAVE WILL BE MOVING
EAST ACROSS THE MISSISSIPPI VALLEY BY FRIDAY NIGHT...CLEARING
THROUGH THE OHIO VALLEY BY SATURDAY EVENING. THE REFLECTION OF
THIS TROUGH LOWER IN THE ATMOSPHERE IS ACTUALLY EVEN
SHARPER...WITH A CLOSED LOW SHOWING UP AT THE SURFACE AND AT
925MB. THIS SYSTEM WILL HAVE A MUCH MORE IMPRESSIVE CONNECTION
TO DEEP GULF MOISTURE THAN HAS BEEN IN PLACE FOR QUITE A WHILE.
ALTHOUGH SOME LIGHT PRECIPITATION IS EXPECTED TO GRADUALLY SPREAD
NORTH THROUGH THE FORECAST AREA TONIGHT AND INTO EARLY FRIDAY
MORNING...THE MAJORITY OF THE RAIN IS EXPECTED TO MOVE INTO THE
SOUTHWESTERN CWA BY 18Z FRIDAY. BY LATE FRIDAY...PRECIPITABLE
WATER VALUES OF OVER AN INCH WILL ADVECT INTO THE ILN FORECAST
AREA...WELL ABOVE CLIMATOLOGICAL NORMALS FOR DECEMBER.
THE 00Z MODELS TONIGHT HAVE MADE A SLIGHT SHIFT NORTHWARD WITH THE
TRACK OF THE SURFACE LOW...AND THUS THE AREA OF GREATEST PROLONGED
LOW-LEVEL CONVERGENCE ALONG THE DEVELOPING FRONTAL STRUCTURE. TO
NO SURPRISE...THE QPF AXIS DEPICTED ON THE VARIOUS MODEL SOLUTIONS
HAS SHIFTED A LITTLE MORE SOLIDLY ACROSS THE ILN FORECAST
AREA...AND RAINFALL AMOUNTS OF OVER AN INCH LOOK VERY LIKELY. A
FEW SPOTS RECEIVING UP TO TWO INCHES MAY OCCUR. DESPITE
THIS...THE FLOODING THREAT APPEARS RELATIVELY MINIMAL. BASED ON
OHRFC MMEFS GUIDANCE...RIVERS (WHICH ARE RUNNING FAIRLY LOW AT THE
MOMENT) DO NOT SHOW A HIGH PROBABILITY FOR FLOODING. A WIDESPREAD
1.0-1.5 INCH RAIN OVER ABOUT 24 HOURS IS ALSO PROBABLY NOT ENOUGH
FOR GENERAL NON-RIVER FLOOD CONCERNS.
THE AMERICAN MODELS (GFS/NAM) REMAIN ON THE FAST SIDE OF THE
GUIDANCE ENVELOPE FOR THE EVENTUAL DEPARTURE OF PRECIPITATION ON
SATURDAY. THE ECMWF/GEM MAINTAIN THE SLOWER END OF THE
PROGRESSION...WITH DEEPER DEPICTIONS OF THE 500MB TROUGH.
WITH A SIGNIFICANT TEMPERATURE GRADIENT EXPECTED TO DEVELOP OVER
THE AREA...ADVECTION-BASED NON-DIURNAL TEMPERATURE TRENDS WERE
USED IN THE GRIDS...CONFIDENCE IN EXACT NUMBERS IS NOT
PARTICULARLY HIGH. PRECIPITATION DOES APPEAR LIKELY TO END BEFORE
TEMPERATURES ARE COLD ENOUGH TO SUPPORT ANYTHING BUT RAIN...BUT
WITH THE SURFACE FRONT BEGINNING ITS SOUTHWARD MOTION EARLY
SATURDAY MORNING...FALLING TEMPERATURES ARE LIKELY ON SATURDAY.
UNDER DRY CONDITIONS...TEMPERATURES WILL END UP WITHIN A FEW
DEGREES EITHER SIDE OF THE FREEZING MARK ON SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
WHILE COLD ADVECTION WILL PERSIST ON SUNDAY...CLEARER SKIES WILL
ALLOW FOR SOME TEMPERATURES TO REACH NEAR OR SLIGHTLY ABOVE CLIMO.
RAIN SHOWERS MONDAY WILL MIX WITH SNOW OVERNIGHT BEFORE ENDING.
THE HIGH WILL REMAIN WELL N OF THE OHIO VALLEY BUT THE AXIS SHOULD
CROSS SUNDAY NIGHT AND SIGNIFY A SWITCH TO SOUTHERLY AND WARMING
FLOW...IF ONLY SLIGHTLY WARMER. ANOTHER COLD FRONT WILL CROSS MONDAY
NIGHT AND TUESDAY WILL BE CLOUDY AND COOL WITH READINGS IN THE 30S.
HIGH PRESSURE WILL THEN POOL NW OF THE REGION FOR THE MIDDLE OF NEXT
WEEK AND BRING MORE NORMAL TEMPERATURES WITH A DRY PATTERN.
MODELS DIVERGE SIGNIFICANTLY MONDAY NIGHT AND FCST IS IN A HIGHER
STATE OF UNCERTAINTY BEYOND THIS TIME.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SEVERAL TAF SITES WILL EXPERIENCE MAINLY MVFR VISIBILITIES FOR
ABOUT A COUPLE OF HOURS THIS MORNING. THICKENING CLOUDS AND WINDS
PICKING UP SLIGHTLY FROM THE EAST FROM DEPARTING HIGH PRESSURE
SHOULD HELP IMPROVE THE VISIBILITIES BY 14Z.
FOR LATER TODAY...AN UPPER LEVEL DISTURBANCE ALONG WITH AN
INCREASING LOW LEVEL JET WILL RESULT IN RAIN DEVELOPMENT TO OUR
SOUTHWEST. THIS RAIN SHIELD WILL EVENTUALLY PUSH NORTHEAST TOWARD
THE OHIO RIVER BY 18Z. KCVG AND KLUK HAVE THE BEST CHANCE TO SEE
RAIN WHERE FORCING WILL BE THE GREATEST. THE THREAT WILL DECREASE
APPRECIABLY NORTH OF KILN TAF SITE. CEILINGS SHOULD REMAIN VFR
WITH PERHAPS A REDUCTION TO MVFR VISIBILITIES AT KCVG/KLUK.
FOR TONIGHT...UPPER LEVEL DISTURBANCE MOVES EAST AND THE LOW LEVEL
JET BRIEFLY WEAKENS EARLY ON. DURING THE LATER PART OF THE NIGHT
INTO FRIDAY MORNING...A WARM...MOIST PUSH IS FORECAST TO OCCUR AND
MOVE NORTHEAST THROUGH THE REGION OVERNIGHT. THE LOW LEVELS WILL
CONTINUE TO SATURATE...RESULTING IN CEILINGS DROPPING INTO THE IFR
CATEGORY WITH VISIBILITIES AT LEAST DROPPING INTO THE MVFR
CATEGORY. THE WEAK ASCENT AND SATURATED LOW LEVELS WILL BRING A
THREAT FOR EITHER DRIZZLE OR LIGHT RAIN...ESPECIALLY BETWEEN 06Z
AND 12Z.
OUTLOOK...IFR/LIFR CEILINGS AND VISIBILITIES LIKELY FRIDAY INTO
FRIDAY NIGHT. MVFR/IFR CEILINGS AND MVFR VISIBILITIES EXPECTED TO
LINGER INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...FRANKS
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
421 AM EST THU DEC 4 2014
.SYNOPSIS...
AN AREA OF RAIN IS EXPECTED TO MOVE INTO THE REGION TODAY...AS A
WARM FRONT GRADUALLY DEVELOPS NEAR THE OHIO RIVER. A MORE POTENT
AREA OF LOW PRESSURE WILL MOVE ACROSS THE OHIO VALLEY ON FRIDAY
AND INTO SATURDAY...WITH RAIN EXPECTED THROUGH SATURDAY AFTERNOON.
AN AREA OF HIGH PRESSURE WILL ALLOW FOR DRIER AND COOLER
CONDITIONS ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SOLID CANOPY OF HIGH CLOUDS HAS OVERSPREAD THE AREA...AND
MID-LEVEL CLOUDS ARE NOW BEING OBSERVED IN FAR SOUTHERN INDIANA
AND WESTERN KENTUCKY. DESPITE THESE CLOUDS...A FEW PATCHES OF FOG
HAVE DEVELOPED...WITH JUST ENOUGH LOW-LEVEL MOISTURE TO LEAD TO
SOME HEAVY FROST. THE FOG HAS NOT BEEN PARTICULARLY DENSE (ONLY A
COUPLE OBSERVATION SITES BRIEFLY DROPPED TO 1/4 MILE)...BUT THERE
IS A CONCERN THAT WHERE FOG IS A LITTLE THICKER...SOME OF IT MAY
DEPOSIT ICE ON SURFACES. THIS WILL BE MONITORED HEADING INTO THE
NEXT FEW HOURS.
NEAR-SURFACE CONDITIONS ARE EXPECTED TO REMAIN FAIRLY COOL
TODAY...WITH EASTERLY FLOW FROM 925MB AND BELOW. HOWEVER...AT
850MB...A WARM FRONT IS ALREADY BEGINNING TO SET UP. THIS FRONT
WILL MOVE NORTH INTO THE ILN FORECAST AREA AFTER 12Z. THE FRONT IS
ALSO EXPECTED TO ACT AS A FOCUS FOR PRECIPITATION...WHICH WILL BE
AIDED BY THE PASSAGE OF A WEAK SHORTWAVE IN THE GENERALLY ZONAL
500MB FLOW. THE MAJORITY OF THIS PRECIPITATION SHOULD REMAIN SOUTH
OF THE OHIO RIVER...BUT LIGHT ACTIVITY IS EXPECTED TO BE POSSIBLE
THROUGH AT LEAST THE SOUTHERN HALF OF THE FORECAST AREA BY LATE
MORNING / EARLY AFTERNOON.
THERE REMAINS SOME SLIGHT CONCERN REGARDING PRECIPITATION
TYPE...AS SURFACE TEMPERATURES WILL BE STARTING OFF IN THE LOWER
30S AND UPPER 20S...AND THE LAYER OF WARM AIR ALOFT IS NOT QUITE
BEING TIMED OUT WITH EXACT CONSISTENCY FROM MODEL TO MODEL. IT
DOES APPEAR LIKELY THAT SURFACE TEMPS WILL BE RISING ABOVE
FREEZING BEFORE PRECIPITATION BEGINS...THOUGH IF THERE IS ANY
CHANCE OF A BRIEF PERIOD OF FREEZING RAIN...IT COULD OCCUR IN
SOUTHEAST INDIANA IN THE 12Z-15Z TIME PERIOD. IT APPEARS THAT THE
MORE LIKELY SCENARIO WILL BE FOR PRECIPITATION BEGINNING JUST AS
THE 925MB-800MB IS IN THE PROCESS OF WARMING ABOVE FREEZING. WITH
SOME SATURATION NEAR THE SURFACE STILL NEEDING TO OCCUR...THIS
TEMPERATURE PROFILE WOULD SUPPORT A BRIEF MIX OF SLEET AND
RAIN...BEFORE THE ENTIRE SOUNDING BELOW 800MB ENDS UP ABOVE
FREEZING. THIS COULD OCCUR AT TWO DIFFERENT TIMES IN THE FORECAST.
THE FIRST OCCURRENCE WOULD BE AS THE INITIAL AREA OF PRECIPITATION
MOVES INTO THE SOUTHWESTERN QUADRANT OF THE FORECAST AREA THIS
MORNING. HRRR AND 4KM WRF OUTPUT DOES SUGGEST THAT THERE WILL BE
VIRGA IN ADVANCE OF SURFACE PRECIPITATION (WITH SIMULATED COMP
REFLECTIVITY SHOWING A GREATER AREAL EXPANSE THAN SIMULATED 1KM
REFLECTIVITY). AS IS SOMETIMES OBSERVED IN THESE SITUATIONS...THE
FIRST HYDROMETEORS TO HIT THE GROUND MAY BE PELLETS.
THE SECOND POSSIBLE OCCURRENCE OF SLEET WOULD BE AS LIGHT
PRECIPITATION EXPANDS NORTHWARD THIS EVENING...AFFECTING THE
NORTHERN HALF OF THE FORECAST AREA. REGARDLESS...WITH SLEET ONLY
LIKELY TO OCCUR FOR A BRIEF PERIOD OF TIME NEAR THE ONSET OF
PRECIPITATION...MEASURABLE ACCUMULATIONS ARE UNLIKELY.
POPS FOR TODAY FOCUS ON THE SOUTHERN THIRD OF THE FORECAST
AREA...WHERE RAIN NOW APPEARS TO BE A CERTAINTY. SURFACE
TEMPERATURES ARE EXPECTED TO REACH THE UPPER 30S TO LOWER
40S...BUT THERE IS SOME CHANCE THAT PRECIPITATION COULD HOLD THESE
VALUES DOWN A FEW DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ATTENTION FOR THE NEXT FEW DAYS WILL TURN TO THE RAIN EXPECTED
ACROSS THE ENTIRE FORECAST AREA FROM FRIDAY THROUGH SATURDAY. A
WELL-DEFINED AND MODERATELY STRONG 500MB SHORTWAVE WILL BE MOVING
EAST ACROSS THE MISSISSIPPI VALLEY BY FRIDAY NIGHT...CLEARING
THROUGH THE OHIO VALLEY BY SATURDAY EVENING. THE REFLECTION OF
THIS TROUGH LOWER IN THE ATMOSPHERE IS ACTUALLY EVEN
SHARPER...WITH A CLOSED LOW SHOWING UP AT THE SURFACE AND AT
925MB. THIS SYSTEM WILL HAVE A MUCH MORE IMPRESSIVE CONNECTION
TO DEEP GULF MOISTURE THAN HAS BEEN IN PLACE FOR QUITE A WHILE.
ALTHOUGH SOME LIGHT PRECIPITATION IS EXPECTED TO GRADUALLY SPREAD
NORTH THROUGH THE FORECAST AREA TONIGHT AND INTO EARLY FRIDAY
MORNING...THE MAJORITY OF THE RAIN IS EXPECTED TO MOVE INTO THE
SOUTHWESTERN CWA BY 18Z FRIDAY. BY LATE FRIDAY...PRECIPITABLE
WATER VALUES OF OVER AN INCH WILL ADVECT INTO THE ILN FORECAST
AREA...WELL ABOVE CLIMATOLOGICAL NORMALS FOR DECEMBER.
THE 00Z MODELS TONIGHT HAVE MADE A SLIGHT SHIFT NORTHWARD WITH THE
TRACK OF THE SURFACE LOW...AND THUS THE AREA OF GREATEST PROLONGED
LOW-LEVEL CONVERGENCE ALONG THE DEVELOPING FRONTAL STRUCTURE. TO
NO SURPRISE...THE QPF AXIS DEPICTED ON THE VARIOUS MODEL SOLUTIONS
HAS SHIFTED A LITTLE MORE SOLIDLY ACROSS THE ILN FORECAST
AREA...AND RAINFALL AMOUNTS OF OVER AN INCH LOOK VERY LIKELY. A
FEW SPOTS RECEIVING UP TO TWO INCHES MAY OCCUR. DESPITE
THIS...THE FLOODING THREAT APPEARS RELATIVELY MINIMAL. BASED ON
OHRFC MMEFS GUIDANCE...RIVERS (WHICH ARE RUNNING FAIRLY LOW AT THE
MOMENT) DO NOT SHOW A HIGH PROBABILITY FOR FLOODING. A WIDESPREAD
1.0-1.5 INCH RAIN OVER ABOUT 24 HOURS IS ALSO PROBABLY NOT ENOUGH
FOR GENERAL NON-RIVER FLOOD CONCERNS.
THE AMERICAN MODELS (GFS/NAM) REMAIN ON THE FAST SIDE OF THE
GUIDANCE ENVELOPE FOR THE EVENTUAL DEPARTURE OF PRECIPITATION ON
SATURDAY. THE ECMWF/GEM MAINTAIN THE SLOWER END OF THE
PROGRESSION...WITH DEEPER DEPICTIONS OF THE 500MB TROUGH.
WITH A SIGNIFICANT TEMPERATURE GRADIENT EXPECTED TO DEVELOP OVER
THE AREA...ADVECTION-BASED NON-DIURNAL TEMPERATURE TRENDS WERE
USED IN THE GRIDS...CONFIDENCE IN EXACT NUMBERS IS NOT
PARTICULARLY HIGH. PRECIPITATION DOES APPEAR LIKELY TO END BEFORE
TEMPERATURES ARE COLD ENOUGH TO SUPPORT ANYTHING BUT RAIN...BUT
WITH THE SURFACE FRONT BEGINNING ITS SOUTHWARD MOTION EARLY
SATURDAY MORNING...FALLING TEMPERATURES ARE LIKELY ON SATURDAY.
UNDER DRY CONDITIONS...TEMPERATURES WILL END UP WITHIN A FEW
DEGREES EITHER SIDE OF THE FREEZING MARK ON SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
WHILE COLD ADVECTION WILL PERSIST ON SUNDAY...CLEARER SKIES WILL
ALLOW FOR SOME TEMPERATURES TO REACH NEAR OR SLIGHTLY ABOVE CLIMO.
RAIN SHOWERS MONDAY WILL MIX WITH SNOW OVERNIGHT BEFORE ENDING.
THE HIGH WILL REMAIN WELL N OF THE OHIO VALLEY BUT THE AXIS SHOULD
CROSS SUNDAY NIGHT AND SIGNIFY A SWITCH TO SOUTHERLY AND WARMING
FLOW...IF ONLY SLIGHTLY WARMER. ANOTHER COLD FRONT WILL CROSS MONDAY
NIGHT AND TUESDAY WILL BE CLOUDY AND COOL WITH READINGS IN THE 30S.
HIGH PRESSURE WILL THEN POOL NW OF THE REGION FOR THE MIDDLE OF NEXT
WEEK AND BRING MORE NORMAL TEMPERATURES WITH A DRY PATTERN.
MODELS DIVERGE SIGNIFICANTLY MONDAY NIGHT AND FCST IS IN A HIGHER
STATE OF UNCERTAINTY BEYOND THIS TIME.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE FORECAST AREA THROUGH
12Z. ALTHOUGH HIGH LEVEL CLOUDS WILL CONTINUE TO THICKEN
OVERNIGHT...SOME MIST/FOG HAS ALREADY FORMED AT SOME OF THE MORE
FOG PRONE TAF SITES SUCH AS KILN AND KLUK. KLUK HAS BASICALLY
DROPPED DOWN 1/4SM IN FZFG WITH CEILINGS RANGING BETWEEN 300 AND 500
FEET. SINCE THE FOG HAS FORMED...AND WITH NO MIXING AT THE SURFACE
OVERNIGHT...IT IS UNCLEAR HOW MUCH THE FOG WILL IMPROVE AT KLUK AS
CLOUDS CONTINUE TO THICKEN. THIS PROCESS MAY EVENTUALLY ALLOW
VISIBILITIES/CEILINGS TO IMPROVE SOME (DUE TO SLIGHT WARMING). HAVE
DECIDED TO KEEP CONDITIONS BELOW AIRPORT MINIMUM AT KLUK UNTIL 13Z
UNTIL THERE SEEMS TO BE TREND ESTABLISHED. THEREAFTER...DAYTIME
HEATING AND SOME MIXING/WIND AS THE CENTER OF THE SURFACE HIGH
PULLS OFF TO THE NORTHEAST SHOULD ALLOW CONDITIONS TO RETURN TO
VFR. ATTM...AM ONLY EXPECTING SOME MVFR VISIBILITIES IN MIST AT
KCVG AND KILN UNTIL 13Z.
FOR LATER TODAY...AN UPPER LEVEL DISTURBANCE ALONG WITH AN
INCREASING LOW LEVEL JET WILL RESULT IN RAIN DEVELOPMENT TO OUR
SOUTHWEST. THIS RAIN SHIELD WILL EVENTUALLY PUSH NORTHEAST TOWARD
THE OHIO RIVER BY 18Z. BEST CHANCE TO SEE RAIN WILL BE AT KCVG AND
KLUK WITH PERHAPS A LOWER THREAT OF LIGHT RAIN FARTHER NORTH AS
THE MAIN FOCUS REMAINS ALONG AND SOUTH OF THE OHIO RIVER. CEILINGS
SHOULD REMAIN VFR WITH PERHAPS A BRIEF REDUCTION TO MVFR
VISIBILITIES AT KCVG/KLUK DUE TO THE LIGHT RAIN.
FOR TONIGHT...UPPER LEVEL DISTURBANCE MOVES EAST AND THE LOW LEVEL
JET BRIEFLY WEAKENS EARLY ON. DURING THE LATER PART OF THE NIGHT
INTO FRIDAY MORNING...A WARM...MOIST PUSH IS FORECAST TO OCCUR AND
MOVE NORTHEAST THROUGH THE REGION OVERNIGHT. THE LOW LEVELS WILL
CONTINUE TO SATURATE...RESULTING IN CEILINGS DROPPING INTO THE IFR
CATEGORY WITH VISIBILITIES AT LEAST DROPPING INTO THE MVFR
CATEGORY. THE WEAK ASCENT AND SATURATED LOW LEVELS WILL BRING A
THREAT FOR EITHER DRIZZLE OR LIGHT RAIN...ESPECIALLY BETWEEN 06Z
AND 12Z.
OUTLOOK...IFR/LIFR CEILINGS VISIBILITIES LIKELY FRIDAY INTO FRIDAY
NIGHT. MVFR/IFR CEILINGS AND MVFR VISIBILITIES EXPECTED TO LINGER
INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...FRANKS
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
957 PM CST FRI DEC 5 2014
.AVIATION...
DENSE FOG IS EXPECTED OVERNIGHT AND UNTIL LATE SATURDAY MORNING IN
A ZONE FROM NORTH CENTRAL INTO CENTRAL OKLAHOMA. MUCH OF THIS WILL
BE WEST OF OKLAHOMA CITY, BUT THE OKLAHOMA CITY MAY RECEIVE
PERIODS OF DENSE FOG ALSO. THE LOW CLOUDS AND FOG WILL BE SLOW TO
ERRODE SATURDAY, ALTHOUGH VISIBILITY WILL INCREASE BY LATE
MORNING. LIGHT NORTH WINDS WILL PERSIST.
&&
.PREV DISCUSSION... /ISSUED 842 PM CST FRI DEC 5 2014/
UPDATE...
HAVE UPDATED GRIDS TO BE MORE AGGRESSIVE WITH FOG DEVELOPMENT. THE
HRRR AND RAP MODELS ARE IN GOOD AGREEMENT WITH DENSE FOG
DEVELOPING AND SPREADING ACROSS MUCH OF NORTH CENTRAL AND CENTRAL
OKLAHOMA THIS EVENING AND OVERNIGHT. VISIBILITIES HAVE FALLEN TO
1/2SM OR LESS IN THE PAST HOUR OR SO AT PONCA CITY... VANCE AFB...
ENID WOODRING... BLACKWELL... ARKANSAS CITY KS AND TEMPORARILY AT
WATONGA AND GAGE. WILL LIKELY NEED A DENSE FOG ADVISORY LATER
THIS EVENING IF THE VISIBILITIES CONTINUE TO WORSEN AND PERSIST.
PREV DISCUSSION... /ISSUED 602 PM CST FRI DEC 5 2014/
AVIATION...
IFR CEILINGS FROM SOUTHWEST TO NORTH CENTRAL OKLAHOMA ARE EXPECTED
TO EXPAND LATER TONIGHT. THE SHALLOW COOL AIRMASS IS EXPECTED TO
HOLD ON THROUGH MUCH OF SATURDAY ALONG WITH THE LOW CEILINGS. FOG
IS EXPECTED LATE TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 42 51 39 54 / 10 10 0 20
HOBART OK 40 50 38 52 / 0 0 10 20
WICHITA FALLS TX 43 55 40 54 / 0 0 10 20
GAGE OK 32 48 34 57 / 0 0 0 10
PONCA CITY OK 39 48 35 52 / 10 10 10 20
DURANT OK 46 58 42 53 / 10 0 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
842 PM CST FRI DEC 5 2014
.UPDATE...
HAVE UPDATED GRIDS TO BE MORE AGGRESSIVE WITH FOG DEVELOPMENT. THE
HRRR AND RAP MODELS ARE IN GOOD AGREEMENT WITH DENSE FOG
DEVELOPING AND SPREADING ACROSS MUCH OF NORTH CENTRAL AND CENTRAL
OKLAHOMA THIS EVENING AND OVERNIGHT. VISIBILITIES HAVE FALLEN TO
1/2SM OR LESS IN THE PAST HOUR OR SO AT PONCA CITY... VANCE AFB...
ENID WOODRING... BLACKWELL... ARKANSAS CITY KS AND TEMPORARILY AT
WATONGA AND GAGE. WILL LIKELY NEED A DENSE FOG ADVISORY LATER
THIS EVENING IF THE VISIBILITIES CONTINUE TO WORSEN AND PERSIST.
&&
.PREV DISCUSSION... /ISSUED 602 PM CST FRI DEC 5 2014/
AVIATION...
IFR CEILINGS FROM SOUTHWEST TO NORTH CENTRAL OKLAHOMA ARE EXPECTED
TO EXPAND LATER TONIGHT. THE SHALLOW COOL AIRMASS IS EXPECTED TO
HOLD ON THROUGH MUCH OF SATURDAY ALONG WITH THE LOW CEILINGS. FOG
IS EXPECTED LATE TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 42 51 39 54 / 10 10 0 20
HOBART OK 40 50 38 52 / 0 0 10 20
WICHITA FALLS TX 43 55 40 54 / 0 0 10 20
GAGE OK 32 48 34 57 / 0 0 0 10
PONCA CITY OK 39 48 35 52 / 10 10 10 20
DURANT OK 46 58 42 53 / 10 0 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
735 PM MST FRI DEC 5 2014
.UPDATE...
ISSUED AT 725 PM MST FRI DEC 5 2014
STALLED LL BAROCLINIC ZONE ACROSS THE FAR NORTH WILL INTERACT
WITH A PASSING MID LEVEL IMPULSE THIS EVENING...POSSIBLY
SUPPORTING A FEW LIGHT SHOWERS ACROSS FAR NW SD. HAVE ADDED A
SLIGHT CHANCE FOR PRECIP THERE...OPTING FOR A WINTRY MIX GIVEN
WARM WEDGE ALOFT. OTHERWISE...SUFFICIENT LL MOISTURE AT THE SFC
MAY SUPPORT PATCHY AREAS OF FOG LATER TONIGHT ACROSS WESTERN SD.
HOWEVER...ENSUING SFC PRESSURE FALLS PER LEE SIDE TROUGHING WILL
SUPPORTING INCREASING LL FLOW...INCREASING TURBULENT MIX DOWN OF
DRY AIR. THIS WILL LIKELY LIMIT COVERAGE OF ANY FOG...ESP AWAY
FROM VALLEYS. HAVE TRIMMED DOWN FOG MENTION AND RELEGATED MENTION
TO PATCHY.
&&
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 207 PM MST FRI DEC 5 2014
UPPER LEVEL ANALYSIS SHOWS A RIDGE OVER THE WESTERN
CONUS...WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS. CANADIAN
SURFACE HIGH IS MOVING SOUTHWARD INTO MT/ND. SKIES ARE PARTLY
CLOUDY...WITH GENERALLY LIGHT WINDS AND TEMPS IN THE UPPER 30S AND
40S.
LIGHT WINDS WILL BECOME SOUTHEASTERLY TONIGHT AS THE SURFACE HIGH
CROSSES ND...BRINGING MOISTURE INTO THE AREA. SEVERAL MODELS ARE
STILL HINTING AT SOME FOG SETTING UP AROUND THE AREA. THE HRRR AND
RAP ARE SHOWING LOW CEILINGS ACROSS THE SD PLAINS DEVELOPING AFTER
MIDNIGHT...AND LATEST RUNS ALSO HAVE FOG WRAPPING AROUND THE
SOUTHERN HILLS INTO NORTHEAST WY. MEANWHILE THE NAM HAS THE BEST
CHANCES FOR FOG AROUND THE HILLS AND INTO NORTHEAST WY...NOT SO MUCH
ON THE SD PLAINS. THE NAM SEEMS TO BE OVERESTIMATING MOISTURE
LATELY...AND SINCE WINDS IN NORTHEAST WY LOOK A LITTLE STRONGER
OVERNIGHT...HAVE MORE UNCERTAINTY ABOUT FOG DEVELOPMENT THERE.
DECREASED AREAS OF FOG TO PATCHY ACROSS NORTHEAST WY...KEEPING AREAS
OF FOG JUST EAST OF THE HILLS. COULD ALSO BE SOME PATCHY FOG IN
SURROUNDING AREAS ACROSS THE SD PLAINS. AS THE SURFACE HIGH MOVES
SOUTHEAST OVERNIGHT...COLD AIR WILL ADVECT INTO THE EASTERN CWA.
LOWS WILL RANGE FROM THE TEENS ACROSS NORTH CENTRAL/NORTHWEST SD TO
THE UPPER 20S IN NORTHEAST WY.
SOUTHERLY WINDS WILL BECOME BREEZY BY LATE SATURDAY MORNING AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN THE HIGH PRESSURE TO THE EAST AND
THE INCOMING LOW. EXPECT FOG TO DISSIPATE BY MID-MORNING. THERE IS
SOME UNCERTAINTY WITH TEMPS ON SATURDAY...AS MODELS HAVE A 10-DEGREE
SPREAD FOR HIGHS IN SOME PLACES. WITH SOUTHERLY BOUNDARY-LAYER WINDS
AND WARM AIR ADVECTION...KEPT TEMPS MILD...IN THE MID 30S NORTH AND
EAST TO THE UPPER 40S FARTHER WEST. LOWS SATURDAY NIGHT WILL BE IN
THE 20S TO LOWER 30S.
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 207 PM MST FRI DEC 5 2014
MODELS ARE IN GOOD AGREEMENT DURING THE EXTENDED
PERIOD...WITH RELATIVELY HIGH PREDICTABILITY THROUGH AT LEAST
WEDNESDAY. IN THE MEAN...THERE WILL BE A LONG-WAVE TROUGH OFF THE
WEST COAST WITH A LONG-WAVE RIDGE NEAR THE CNTRL CONUS.
ON SUNDAY A SHORT-WAVE TROUGH WILL MOVE ACROSS THE FAR NRN PLAINS
AND THROUGH THE L/W RIDGE...BRINGING A COLD FRONT AND NORTHWEST WIND
SHIFT ACROSS THE CWA. THIS WILL BRING SCT SHRASN TO THE BLKHLS. ON
MONDAY THROUGH WEDNESDAY THE RIDGE REBOUNDS...BUT WITH A WEAK SHORT-
WAVE TROUGH SLOWLY MOVING ACROSS THE NRN PLAINS. THIS IS NOT
EXPECTED TO BRING ANY PRECIP TO THE CWA GIVEN THE LIMITED FORCING
FOR ASCENT AND LACK OF LOW- TO MID-LEVEL MOISTURE.
ON THURSDAY AND FRIDAY...THE LONG-WAVE TROUGH MOVES INTO THE ERN
HALF OF THE CONUS WITH SOUTHWEST FLOW ALOFT DEVELOPING ACROSS THE
CWA IN RESPONSE TO A DEEP UPPER LOW COMING ONSHORE NEAR CA. THE GFS
SEEMS A BIT AGGRESSIVE WITH THIS LOW...SO HAVE KEPT THE FORECAST DRY
THROUGH FRIDAY. NEVERTHELESS...THERE ARE INDICATIONS THAT A BIG
STORM COULD BE LOOMING ON THE HORIZON FOR LATE NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 427 PM MST FRI DEC 5 2014
VFR CONDITIONS EXPECTED THROUGH THE PERIOD MOST PLACES. INCREASED
BL MOISTURE WITH A PERIOD OF LIGHT WINDS AND CLEAR SKIES MAY
SUPPORT PATCHY/AREAS OF FOG TONIGHT. HOWEVER...INCREASING LL
SOUTHERLY FLOW AND LIMITED MOISTURE ADVECTION SHOULD LIMIT
COVERAGE OF ANY FOG/STRATUS. GIVEN LOW PROBS/CONFIDENCE HAVE
OPTED TO LEAVE OUT OF TERMINALS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JC
SHORT TERM...POJORLIE
LONG TERM...BUNKERS
AVIATION...JC
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
658 PM CST FRI DEC 5 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 304 PM CST FRI DEC 5 2014
ALTHOUGH VISIBILITY HAS IMPROVED...FOG CONTINUES TO RESIDE THROUGH
NORTHWEST IOWA THIS AFTERNOON...SO THE BIGGEST CHALLENGE TONIGHT
REMAINS HOW QUICKLY FOG ERODES AS DRIER AIR FILTERS IN BEHIND THE
SURFACE TROUGH PUSHING ACROSS THE REGION. WATCHING THE TRENDS
THROUGH THE AFTERNOON...VISIBILITIES HAVE QUICKLY IMPROVED AS THE
WINDS TRANSITIONED TO NORTHERLY BEHIND THE TROUGH AND THE DRIER AIR
DRAINED IN. USING THAT AND RAP 925 MB RH FIELDS WHICH HAVE ALSO
CORRELATED WELL WITH THE FOG...HAVE THE FOG LINGERING THROUGH
PORTIONS OF NORTHWEST IOWA THROUGH THE EVENING THEN SLOWLY ERODING
FROM THE NORTH AND WEST AS DRIER AIR TAKES OVER DURING THE NIGHT.
COLDER AIR WILL ALSO FILTER SOUTH OVERNIGHT...WITH LOWS BOTTOMING
OUT AROUND 10 THROUGH THE HIGHWAY 14 CORRIDOR TO THE UPPER TEENS
THROUGH THE MISSOURI RIVER VALLEY.
SURFACE HIGH PRESSURE SETTLES INTO THE REGION ON SATURDAY...SO
SHOULD SEE SOME SUN ALONG WITH RELATIVELY LIGHT WINDS DURING THE DAY
WITH A WEAK GRADIENT EXISTING ACROSS THE REGION. WITH THERMAL
PROFILES A LITTLE COOLER HIGHS WILL RANGE FROM THE LOWER 30S NORTH
TO UPPER 30S SOUTH.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 304 PM CST FRI DEC 5 2014
THE PRIMARY FORECAST CONCERNS IN THE MEDIUM AND SHORT RANGE CONTINUE
TO FOCUS ON LIGHT PRECIPITATION CHANCES SUNDAY AND WARMUP INTO
NEXT WEEK/WEEKEND.
SUNDAY...MODELS STILL ON TRACK BRINGING TWO PIECES OF SHORTWAVE
ENERGY INTO THE REGION LATE SATURDAY NIGHT AND INTO SUNDAY. THE
FIRST WAVE WILL LIFT NORTHWARD FROM THE SOUTHWESTERN US WITH THE
SECOND WAVE DIPPING SOUTHEAST FROM THE PACIFIC NORTHWEST.
AGAIN...MOISTURE REMAINS RATHER SHALLOW IN NATURE AS THESE WAVES
MOVE THROUGH BUT AM ANTICIPATING A NARROW CORRIDOR OF LIGHT FREEZING
RAIN/DRIZZLE DEVELOPING NEAR DAYBREAK ALONG AND WEST OF I-29. WHILE
THE ATMOSPHERIC PROFILE LACKS ICE CRYSTALS FOR MOST OF THE
EVENT...THERE COULD BE A BRIEF WINDOW OF SATURATION EARLY IN THE
AFTERNOON WHICH WOULD OWE TO SLEET INTRODUCTION ESPECIALLY IN THE NE
ZONES. THE PRECIPITATION SHOULD BE LIGHT ENOUGH TO AVOID ANY
MAJOR ICING CONCERNS...ESPECIALLY SINCE SFC TEMPERATURES WILL
CONTINUE TO RISE THROUGH THE MORNING AND SHOULD CLIMB ABOVE
FREEZING IN THE AFTERNOON.
NEXT WEEK...SLIGHT MODEL DIFFERENCES CONTINUE FOR MUCH OF NEXT WEEK
WITH BOTH MAJOR EXTENDED RANGE MODELS SHOWING INCREASED RIDGING
ACROSS THE CONUS INTO NEXT WEEKEND. TEMPERATURES WILL COOL SLIGHTLY
BEHIND SUNDAYS DEPARTING TROUGH...BUT STILL AVERAGE NEAR OR SLIGHTLY
ABOVE SEASONAL NORMALS. FAIRLY SUBSTANTIAL DIFFERENCES PERSIST IN
THE HANDLING OF SHORTWAVE ENERGY MOVING THROUGH THE PACIFIC
NORTHWEST ON MONDAY. ECMWF KEEPS THIS ENERGY WELL NORTH OF THE
CWA...MEANWHILE THE GFS PULLS THE WAVE THROUGH THE CENTRAL PLAINS.
THE END RESULTS COULD BE SUBSTANTIAL DIFFERENT FOR WEDNESDAY-
FRIDAY. SHOULD THE GFS SOLUTION VERIFY...THE RESULT WOULD BE
INCREASED CLOUD COVER...FOG...AND SLIGHTLY COOLER TEMPS IN THE
LOCAL AREA. ON THE FLIPSIDE...THE MORE AMPLIFIED ECMWF SOLN COULD
SUGGEST VERY WARM TEMPERATURES THURSDAY AND INTO THE WEEKEND. FOR
TODAY...PREFERENCES CONTINUE TO FALL TOWARDS THE ECMWF...BUT WILL
HEDGE A BIT TOWARDS THE OTHER CAMP OF SOLNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 654 PM CST FRI DEC 5 2014
SOME PESKY IFR CEILINGS/MVFR VISIBILITIES ARE EXPECTED TO LINGER
AROUND KSUX THROUGH AT LEAST 02Z...AND MVFR VISIBILITIES AT LEAST
THROUGH 08Z...AS LOW LEVEL NORTHERLY FLOW CONTINUES TO ADVECT THE
LINGERING LOW CLOUDS SOUTHWARD THIS EVENING. WILL HAVE TO WATCH
FOR REFORMING OF LOWER CLOUDS AND FOG AROUND SIOUX CITY WITH
HIGHER MOISTURE CONTENT OF THE LOWER LEVEL AIR MASS WILL BE LESS
LIKELY TO FULLY FLUSH OUT AS FLOW WEAKENS TOWARD RIDGE AXIS LATER
IN THE NIGHT...AND ACTUALLY TURNS EAST/SOUTHEAST AT LOW LEVELS
DURING THE MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...DUX
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
436 PM MST FRI DEC 5 2014
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 207 PM MST FRI DEC 5 2014
UPPER LEVEL ANALYSIS SHOWS A RIDGE OVER THE WESTERN
CONUS...WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS. CANADIAN
SURFACE HIGH IS MOVING SOUTHWARD INTO MT/ND. SKIES ARE PARTLY
CLOUDY...WITH GENERALLY LIGHT WINDS AND TEMPS IN THE UPPER 30S AND
40S.
LIGHT WINDS WILL BECOME SOUTHEASTERLY TONIGHT AS THE SURFACE HIGH
CROSSES ND...BRINGING MOISTURE INTO THE AREA. SEVERAL MODELS ARE
STILL HINTING AT SOME FOG SETTING UP AROUND THE AREA. THE HRRR AND
RAP ARE SHOWING LOW CEILINGS ACROSS THE SD PLAINS DEVELOPING AFTER
MIDNIGHT...AND LATEST RUNS ALSO HAVE FOG WRAPPING AROUND THE
SOUTHERN HILLS INTO NORTHEAST WY. MEANWHILE THE NAM HAS THE BEST
CHANCES FOR FOG AROUND THE HILLS AND INTO NORTHEAST WY...NOT SO MUCH
ON THE SD PLAINS. THE NAM SEEMS TO BE OVERESTIMATING MOISTURE
LATELY...AND SINCE WINDS IN NORTHEAST WY LOOK A LITTLE STRONGER
OVERNIGHT...HAVE MORE UNCERTAINTY ABOUT FOG DEVELOPMENT THERE.
DECREASED AREAS OF FOG TO PATCHY ACROSS NORTHEAST WY...KEEPING AREAS
OF FOG JUST EAST OF THE HILLS. COULD ALSO BE SOME PATCHY FOG IN
SURROUNDING AREAS ACROSS THE SD PLAINS. AS THE SURFACE HIGH MOVES
SOUTHEAST OVERNIGHT...COLD AIR WILL ADVECT INTO THE EASTERN CWA.
LOWS WILL RANGE FROM THE TEENS ACROSS NORTH CENTRAL/NORTHWEST SD TO
THE UPPER 20S IN NORTHEAST WY.
SOUTHERLY WINDS WILL BECOME BREEZY BY LATE SATURDAY MORNING AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN THE HIGH PRESSURE TO THE EAST AND
THE INCOMING LOW. EXPECT FOG TO DISSIPATE BY MID-MORNING. THERE IS
SOME UNCERTAINTY WITH TEMPS ON SATURDAY...AS MODELS HAVE A 10-DEGREE
SPREAD FOR HIGHS IN SOME PLACES. WITH SOUTHERLY BOUNDARY-LAYER WINDS
AND WARM AIR ADVECTION...KEPT TEMPS MILD...IN THE MID 30S NORTH AND
EAST TO THE UPPER 40S FARTHER WEST. LOWS SATURDAY NIGHT WILL BE IN
THE 20S TO LOWER 30S.
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 207 PM MST FRI DEC 5 2014
MODELS ARE IN GOOD AGREEMENT DURING THE EXTENDED
PERIOD...WITH RELATIVELY HIGH PREDICTABILITY THROUGH AT LEAST
WEDNESDAY. IN THE MEAN...THERE WILL BE A LONG-WAVE TROUGH OFF THE
WEST COAST WITH A LONG-WAVE RIDGE NEAR THE CNTRL CONUS.
ON SUNDAY A SHORT-WAVE TROUGH WILL MOVE ACROSS THE FAR NRN PLAINS
AND THROUGH THE L/W RIDGE...BRINGING A COLD FRONT AND NORTHWEST WIND
SHIFT ACROSS THE CWA. THIS WILL BRING SCT SHRASN TO THE BLKHLS. ON
MONDAY THROUGH WEDNESDAY THE RIDGE REBOUNDS...BUT WITH A WEAK SHORT-
WAVE TROUGH SLOWLY MOVING ACROSS THE NRN PLAINS. THIS IS NOT
EXPECTED TO BRING ANY PRECIP TO THE CWA GIVEN THE LIMITED FORCING
FOR ASCENT AND LACK OF LOW- TO MID-LEVEL MOISTURE.
ON THURSDAY AND FRIDAY...THE LONG-WAVE TROUGH MOVES INTO THE ERN
HALF OF THE CONUS WITH SOUTHWEST FLOW ALOFT DEVELOPING ACROSS THE
CWA IN RESPONSE TO A DEEP UPPER LOW COMING ONSHORE NEAR CA. THE GFS
SEEMS A BIT AGGRESSIVE WITH THIS LOW...SO HAVE KEPT THE FORECAST DRY
THROUGH FRIDAY. NEVERTHELESS...THERE ARE INDICATIONS THAT A BIG
STORM COULD BE LOOMING ON THE HORIZON FOR LATE NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 427 PM MST FRI DEC 5 2014
VFR CONDITIONS EXPECTED THROUGH THE PERIOD MOST PLACES. INCREASED
BL MOISTURE WITH A PERIOD OF LIGHT WINDS AND CLEAR SKIES MAY
SUPPORT PATCHY/AREAS OF FOG TONIGHT. HOWEVER...INCREASING LL
SOUTHERLY FLOW AND LIMITED MOISTURE ADVECTION SHOULD LIMIT
COVERAGE OF ANY FOG/STRATUS. GIVEN LOW PROBS/CONFIDENCE HAVE
OPTED TO LEAVE OUT OF TERMINALS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...POJORLIE
LONG TERM...BUNKERS
AVIATION...JC
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
335 AM CST THU DEC 4 2014
.DISCUSSION...
LATEST SURFACE OBSERVATIONS SHOW COLD FRONT THAT HAS BEEN
WAFFLING BACK AND FORTH ACROSS THE MID STATE HAS BECOME ILL
DEFINED AND DIFFUSE IN THE VICINITY OF CENTRAL ALABAMA AND
GEORGIA...WITH TEMPERATURES IN THE UPPER 30S AND 40S ACROSS OUR
CWA. RADAR IMAGERY THIS MORNING SHOWS NUMEROUS SHOWERS HAVE
DEVELOPED OVER THE MID STATE IN RESPONSE TO AN UPPER LEVEL
SHORTWAVE APPARENT ON WATER VAPOR IMAGERY OVER THE SOUTHERN
PLAINS. LATEST HRRR MODEL RUNS INDICATE ADDITIONAL SHOWERS WILL
LIKELY DEVELOP LATER THIS MORNING OVER THE NORTHERN HALF OF THE
CWA IN ASSOCIATION WITH THIS FEATURE BEFORE MOVING OUT BY
AFTERNOON....WITH CLOUDY SKIES AND COOL CONDITIONS CONTINUING.
AS ANOTHER SHORTWAVE APPROACHES OUR REGION FROM NORTHERN MEXICO
LATER TODAY...FRONTAL BOUNDARY IS EXPECTED TO BECOME MORE DEFINED
AND RETURN NORTHWARD AS A WARM FRONT...REACHING THE KY BORDER
VICINITY BY 12Z FRIDAY PER 00Z GUIDANCE. DEWPOINTS IN THE 50S TO
AROUND 60 ARE ANTICIPATED TO SPREAD NORTHWARD INTO MIDDLE
TENNESSEE TONIGHT...RESULTING IN LOW TEMPERATURES LIKELY BEING
REACHED THIS EVENING FOR MANY LOCATIONS THEN SLOWLY WARMING
THROUGH THE NIGHT INTO FRIDAY. IN ADDITION...AFTER A LULL IN
ACTIVITY THIS AFTERNOON AND EVENING...MORE SHOWERS SHOULD DEVELOP
THURSDAY NIGHT WITH THE RETURNING BOUNDARY AND INCREASE IN LOW
LEVEL MOISTURE.
H5 SHORTWAVE PROGGED BY 00Z MODELS TO MOVE ACROSS THE REGION ON
FRIDAY WITH A SECONDARY TROUGH AXIS SHIFTING THROUGH THE AREA
FRIDAY NIGHT INTO SATURDAY. TEMPERATURES SHOULD WARM
SIGNIFICANTLY DURING THE DAY ON FRIDAY AS WARM FRONT MOVES OFF TO
OUR NORTH...REACHING WELL INTO THE 60S TO AROUND 70 BY FRIDAY
AFTERNOON. 00Z MODELS DEPICT A WEAK SURFACE LOW AND ASSOCIATED
COLD FRONT DEVELOPING ACROSS THE SOUTHERN PLAINS THEN SHIFTING
EASTWARD ACROSS THE OHIO/TENNESSEE VALLEYS FRIDAY NIGHT INTO EARLY
SATURDAY. STRONG VERTICAL MOTION ASSOCIATED WITH THE SURFACE AND
UPPER LEVEL FEATURES ALONG WITH THE PLENTIFUL LOW LEVEL MOISTURE
AND WEAK ELEVATED INSTABILITY WILL ALLOW FOR NUMEROUS SHOWERS AND
A FEW THUNDERSTORMS TO DEVELOP DURING THIS TIME PERIOD. HAVE
RAISED POPS FURTHER FOR THE FRIDAY THROUGH SATURDAY TIMEFRAME AS
CONFIDENCE IN HIGH IN WIDESPREAD PRECIPITATION...ESPECIALLY FROM
06/00Z TO 06/12Z FRIDAY NIGHT. GFS/ECMWF/WPC QPF ALL VERY
AGREEABLE ON THE MID STATE SEEING AROUND 1 TO 1.5 INCHES OF TOTAL
RAINFALL FOR THIS TWO DAY PERIOD.
COLD FRONT MOVING THROUGH EARLY IN THE DAY ON SATURDAY SHOULD
CAUSE HIGHS TO OCCUR IN THE MORNING WITH TEMPERATURES FALLING
THROUGH THE DAY. DRIER CP AIRMASS IN THE WAKE OF THE FRONT LOOKS
TO FINALLY SWEEP OUR PERSISTENT LOW CLOUD COVER OUT BY SUNDAY.
00Z GFS/ECMWF CONTINUE TO SHOW VERY POOR RUN TO RUN CONSISTENCY
WITH THE UPPER PATTERN FOR NEXT WEEK...BUT IN GENERAL NEAR TO
BELOW NORMAL TEMPERATURES APPEAR LIKELY WITH NO POPS CURRENTLY
ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 56 52 68 57 / 50 50 80 100
CLARKSVILLE 48 47 67 53 / 60 50 80 100
CROSSVILLE 55 51 62 54 / 40 40 60 100
COLUMBIA 62 53 66 57 / 20 40 70 100
LAWRENCEBURG 63 54 68 57 / 20 40 70 100
WAVERLY 55 51 67 55 / 50 50 80 100
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
810 PM CST FRI DEC 5 2014
.UPDATE...
COLD FRONT IS ABOUT HALFWAY THROUGH THE CWA THIS EVENING BUT MOST
OF THE SHOWER ACTIVITY HAS DIMINISHED AS UPPER TROUGH PULLS
FARTHER AWAY TO THE EAST. OUTSIDE OF AN ISOLATED SHOWER RIGHT
ALONG THE FRONT...MOST AREAS WILL NOT SEE ANY RAIN. LOWERED POPS
FOR THE REMAINDER OF THE EVENING AND CONFINED THEM TO A NARROW
BAND RIGHT ALONG THE FRONT OVER THE EASTERN COUNTIES.
OTHERWISE...ONLY SOME MINOR DOWNWARD TWEAKS IN LOW TEMPERATURES
WERE NEEDED ACROSS THE NORTH AND NORTHWEST COUNTIES.
DUNN
&&
.AVIATION...
/ISSUED 613 PM CST FRI DEC 5 2014/
A COLD FRONT THAT EXTENDED SOUTH OF A HUGO OKLAHOMA /KHHW/ TO
JUST NORTH OF DFW TO JUST SOUTH OF STEPHENVILLE /KSEP/ AT 00Z
WILL MOVE SOUTHEAST THROUGH THE REST OF THE METROPLEX TAF SITES
DURING THE NEXT HOUR AND INTO THE WACO AREA AROUND 03Z. NORTHWEST
WINDS OF 15 TO 20 KNOTS WILL OCCUR WITH FRONTAL PASSAGES...WITH
WIND SPEEDS DECREASING TO AROUND 10 KNOTS A COUPLE OF HOURS BEHIND
FRONT. MVFR CEILINGS WILL DEVELOP BEHIND THE FRONT BY 07Z IN THE
METROPLEX...AND 09Z AT WACO. SOME IFR CONDITIONS ARE POSSIBLE
11-15Z. EXPECT VFR CONDITIONS TO RETURN BY 17Z SATURDAY.
58
&&
.PREV DISCUSSION... /ISSUED 339 PM CST FRI DEC 5 2014/
FOR TODAY...THE ONLY SIGNIFICANT CHANGE TO THE FORECAST FROM THE
MORNING UPDATE WAS TO INCREASE POPS SLIGHTLY ALONG AND SOUTHEAST
OF THE FORECAST POSITION OF THE COLD FRONT ACROSS THE CWA THROUGH
TONIGHT. EARLY AFTERNOON RUNS OF THE HRRR CONSISTENTLY ADVERTISE A
SCATTERED LINE OF SHOWERS DEVELOPING ALONG THE LEADING EDGE OF THE
COLD FRONT AS IT MOVES ACROSS THE CWA. AT 20Z/2PM...THE SURFACE
OBSERVATIONS INDICATED THAT THE LEADING EDGE OF THE COLD FRONT WAS
LOCATED ALONG A LINE FROM ARDMORE TO BOWIE TO BRECKENRIDGE. EARLY
AFTERNOON VISIBLE SATELLITE IMAGERY SHOWED A THIN LINE OF CUMULUS
ORGANIZING ALONG THE FRONT...SUPPORTING THE HRRR FORECAST FOR
STRONGER LIFT AND BETTER RAIN SHOWER CHANCES IN THE IMMEDIATE
VICINITY OF THE FRONT.
DESPITE THE INCREASE IN RAIN CHANCES IN THE SHORT TERM
FORECAST...CONTINUE TO THINK CHANCES OF LIGHTNING ARE LOW. 19Z
AIRCRAFT SOUNDINGS FROM KDFW AND KDAL AIRPORTS CONTINUE TO SHOW
MID-LEVEL LAPSE RATES THAT ARE TOO STABLE TO SUPPORT FREE
CONVECTION. LAPSE RATES HAVE INCREASED A BIT FROM 12Z...LIKELY DUE
FROM DYNAMIC LIFT ASSOCIATED WITH A SHORTWAVE TROUGH LOCATED OVER
OKLAHOMA EARLY THIS AFTERNOON ACCORDING TO WATER VAPOR SATELLITE
IMAGERY. HOWEVER DUE TO THE POSITION OF THE SHORTWAVE
TROUGH...THINK THAT THE EFFECTS OF DYNAMIC LIFT ON OUR MID-LEVEL
LAPSE RATES HAVE ALREADY OCCURRED. AS A RESULT...LEFT
PRECIPITATION ALONG THE FRONT THUNDERSTORM FREE THROUGH TONIGHT.
WILL CERTAINLY CONTINUE TO MONITOR AIRCRAFT OBSERVATIONS THROUGH
THIS EVENING...AND WILL UPDATE THE FORECAST IF IT LOOKS LIKE
THUNDER IS BECOMING MORE LIKELY.
SATURDAY...THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE ENTIRE
FORECAST AREA BY SATURDAY MORNING...LEAVING COOLER AND MUCH DRIER
AIR IN PLACE ACROSS THE REGION. ALTHOUGH THE COLD FRONT DOES NOT
REPRESENT A STRONG CANADIAN AIRMASS...AFTER TODAY`S TEMPERATURES
IN THE MID TO UPPER 70S...IT WILL CERTAINLY BE NOTICEABLY COOLER
TOMORROW BEHIND THE FRONT. HIGHS ARE EXPECTED TO TOP OUT NEAR 60
DEGREES FOR MOST LOCATIONS...VERY CLOSE TO NORMAL HIGHS FOR THIS
TIME OF YEAR. BETWEEN LOW-LEVEL DRY AIR ADVECTION BEHIND THE FRONT
AND SHORTWAVE RIDGING ALOFT...MAINTAINED A DRY FORECAST FOR
SATURDAY.
SUNDAY...A RELATIVELY FAST MOVING SHORTWAVE TROUGH...CURRENTLY
LOCATED ABOUT 800 MILES WEST OF BAJA CALIFORNIA...IS EXPECTED TO
MOVE OVER THE SOUTHERN PLAINS SUNDAY AFTERNOON. WITH A LOW-LEVEL
COOL AIRMASS STILL IN PLACE ACROSS THE CWA BEHIND TODAY`S
FRONT...ALL MODEL GUIDANCE INDICATES THAT THIS SHORTWAVE TROUGH
WILL RESULT IN STRONG WARM AIR ADVECTION OVER THE CWA ON SUNDAY.
WARM AIR ADVECTION OVER THE COOL LOW-LEVEL AIRMASS DOES REPRESENT
PERSISTENT LIFT...HOWEVER PRECIPITATION PROSPECTS FOR THE REGION
LOOK VERY LIMITED AT THIS TIME. DESPITE NEARLY ALL MODELS SHOWING
THE PERSISTENT LIFT ON SUNDAY...THE PROSPECTS FOR MOISTURE RETURN
LOOK VERY LIMITED...AND FOCUSED ON LOCATIONS JUST WEST AND SOUTH
OF THE CWA. AS A RESULT...WENT AHEAD AND BUMPED POPS DOWN 10
PERCENT ACROSS THE ENTIRE AREA THROUGHOUT THE DAY ON SUNDAY.
THINK THAT OUR BEST CHANCES FOR LIGHT RAINFALL MAY BE WHEN THE
SHORTWAVE TROUGH MOVES DIRECTLY OVERHEAD SUNDAY AFTERNOON. MODELS
SHOW A BAND OF RELATIVELY STRONG MID-LEVEL FRONTOGENETIC FORCING
MOVING OVER THE CWA RIGHT OUT AHEAD OF THE SHORTWAVE ON SUNDAY.
THIS WILL LIKELY RESULT IN SOME ELEVATED PRECIPITATION...HOWEVER
THE LOW-LEVEL AIRMASS LOOKS DRY ENOUGH THAT MOST OF THIS SHOULD
EVAPORATE BEFORE REACHING THE SURFACE. AT ANY RATE...THE END
RESULT WAS THAT ISOLATED RAIN SHOWERS WERE INCLUDED IN THE
FORECAST EVEN WHERE POPS ARE AS LOW AS 10 PERCENT TO ACCOUNT FOR
THIS VIRGA/LIGHT RAIN POTENTIAL.
MONDAY INTO TUESDAY...IN GENERAL...A REINFORCING SHOT OF COOL AND
DRY AIR WILL BUILD INTO THE AREA BEHIND SUNDAY`S SHORTWAVE TROUGH
KEEPING US DRY ACROSS NORTH TEXAS FOR EARLY NEXT WEEK. THE LARGE
SCALE UPPER AIR PATTERN IS EXPECTED TO BE DOMINATED BY LARGE
TROUGHS OVER THE FAR EAST AND WEST COASTS...RESULTING IN BROAD
RIDGING OR NEARLY ZONAL FLOW OVER THE CENTRAL PORTION OF THE
COUNTRY. THIS PATTERN ALSO GENERALLY FAVORS DRY WEATHER FOR THE
CWA...HOWEVER PERSISTENT WESTERLY FLOW ALOFT OVER THE CONUS
ROCKIES WILL RESULT IN LEE-SIDE TROUGHING INCREASING IN INTENSITY
THROUGHOUT THE WEEK. WITH LEE-SIDE TROUGHING DEVELOPING AND A COOL
AIRMASS IN PLACE...WE WILL ONCE AGAIN HAVE A SITUATION WHERE WE
HAVE SOUTHERLY FLOW ALOFT IMPINGING ON A COOL LOW-LEVEL AIRMASS
NEAR THE SURFACE. THIS WILL RESULT IN PERSISTENT...ALBEIT
WEAK...LIFT AND MOISTURE RETURN BY TUESDAY AFTERNOON. BACKED OFF
ON POPS A BIT FROM THE PREVIOUS FORECAST ON TUESDAY...HOWEVER
MAINTAINED SOME 20 POPS OVER THE FAR WESTERN CWA TUESDAY
AFTERNOON...NEAREST TO THE LOW-LEVEL MOISTURE RETURN CONSISTENTLY
ADVERTISED IN MEDIUM RANGE GUIDANCE.
WEDNESDAY...MODELS ADVERTISE THAT THE UPPER LEVEL PATTERN WILL
AMPLIFY WITH RIDGING BUILDING OVER THE CONUS ROCKIES IN RESPONSE
TO A STRONG UPPER TROUGH BUILDING EASTWARD...FARTHER ON SHORE THE
WESTERN CONUS COAST. THIS RESULTS IN NORTHWEST FLOW ALOFT OVER THE
REGION ON WEDNESDAY...IN WHICH MODELS HAVE BEEN CONSISTENTLY
SENDING A STRONG BUT COMPACT SHORTWAVE TROUGH SOUTHEAST THROUGH
THE CWA OVER THE PAST COUPLE OF DAYS. THIS TROUGH IS EXPECTED TO
REMAIN WELL NORTH OF NORTH TEXAS...BUT SHOULD HELP SPREAD SOME OF
THE MOISTURE RETURN FROM WEST TEXAS EASTWARD OVER THE CWA ON
WEDNESDAY. IF MOISTURE DOES SPREAD EAST AS ADVERTISED AND LOW-
LEVEL WARM AIR ADVECTION AND ISENTROPIC LIFT CONTINUES... LIGHT
RAIN SHOWERS WILL LIKELY SPREAD ACROSS THE ENTIRE CWA ON
WEDNESDAY. BECAUSE LIFT IS EXPECTED TO REMAIN WEAK...RAIN SHOWERS
SHOULD BE SPOTTY/HIT-AND-MISS ON WEDNESDAY.
THURSDAY AND FRIDAY...MODELS INDICATE THAT LOW-LEVEL WARM AIR
ADVECTION PERSISTS...HOWEVER MODELS ARE ALSO BRINGING THE UPPER
LEVEL RIDGE OUT FROM THE CONUS ROCKIES AND OVER THE GREAT PLAINS
FOR THE LATTER PART OF THE WEEK. DESPITE PERSISTENT LOW-LEVEL
LIFT...WILL FAVOR THE UPPER LEVEL RIDGING IN THIS FORECAST AND
KEEP THURSDAY AND FRIDAY DRY FOR NOW AS MID AND UPPER LEVEL
FORCING SHOULD BE DOMINATED BY SUBSIDENCE.
NEXT WEEKEND...MODELS ARE DEFINITELY STRUGGLING WITH RUN TO RUN
AND MODEL TO MODEL CONSISTENCY WITH REGARDS TO THE EVOLUTION OF
THE STRONG WEST COAST UPPER TROUGH. HOWEVER...MODELS HAVE BEEN
CONSISTENTLY BRINGING THIS TROUGH OVER THE PLAINS NEXT
WEEKEND...WHICH MAY RESULT IN SOME DECENT RAIN CHANCES FOR THE
REGION. THIS IS CURRENTLY BEYOND THE VALID FORECAST PERIOD...BUT
IT IS A SYSTEM THAT WE WILL BE KEEPING A CLOSE EYE ON IN THE
COMING DAYS.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 49 61 44 57 43 / 5 5 5 10 10
WACO, TX 51 63 46 57 43 / 10 10 10 20 20
PARIS, TX 49 60 42 56 39 / 20 10 5 10 10
DENTON, TX 45 60 42 56 41 / 5 5 5 10 5
MCKINNEY, TX 45 60 42 57 40 / 5 5 5 10 10
DALLAS, TX 50 61 45 56 44 / 5 5 5 10 10
TERRELL, TX 49 62 44 58 40 / 10 5 5 10 10
CORSICANA, TX 52 63 45 59 43 / 20 10 10 20 20
TEMPLE, TX 51 64 46 58 44 / 10 10 10 20 20
MINERAL WELLS, TX 45 60 42 56 42 / 0 5 10 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
613 PM CST FRI DEC 5 2014
.AVIATION...
A COLD FRONT THAT EXTENDED SOUTH OF A HUGO OKLAHOMA /KHHW/ TO
JUST NORTH OF DFW TO JUST SOUTH OF STEPHENVILLE /KSEP/ AT 00Z
WILL MOVE SOUTHEAST THROUGH THE REST OF THE METROPLEX TAF SITES
DURING THE NEXT HOUR AND INTO THE WACO AREA AROUND 03Z. NORTHWEST
WINDS OF 15 TO 20 KNOTS WILL OCCUR WITH FRONTAL PASSAGES...WITH
WIND SPEEDS DECREASING TO AROUND 10 KNOTS A COUPLE OF HOURS BEHIND
FRONT. MVFR CEILINGS WILL DEVELOP BEHIND THE FRONT BY 07Z IN THE
METROPLEX...AND 09Z AT WACO. SOME IFR CONDITIONS ARE POSSIBLE
11-15Z. EXPECT VFR CONDITIONS TO RETURN BY 17Z SATURDAY.
58
&&
.PREV DISCUSSION... /ISSUED 339 PM CST FRI DEC 5 2014/
FOR TODAY...THE ONLY SIGNIFICANT CHANGE TO THE FORECAST FROM THE
MORNING UPDATE WAS TO INCREASE POPS SLIGHTLY ALONG AND SOUTHEAST
OF THE FORECAST POSITION OF THE COLD FRONT ACROSS THE CWA THROUGH
TONIGHT. EARLY AFTERNOON RUNS OF THE HRRR CONSISTENTLY ADVERTISE A
SCATTERED LINE OF SHOWERS DEVELOPING ALONG THE LEADING EDGE OF THE
COLD FRONT AS IT MOVES ACROSS THE CWA. AT 20Z/2PM...THE SURFACE
OBSERVATIONS INDICATED THAT THE LEADING EDGE OF THE COLD FRONT WAS
LOCATED ALONG A LINE FROM ARDMORE TO BOWIE TO BRECKENRIDGE. EARLY
AFTERNOON VISIBLE SATELLITE IMAGERY SHOWED A THIN LINE OF CUMULUS
ORGANIZING ALONG THE FRONT...SUPPORTING THE HRRR FORECAST FOR
STRONGER LIFT AND BETTER RAIN SHOWER CHANCES IN THE IMMEDIATE
VICINITY OF THE FRONT.
DESPITE THE INCREASE IN RAIN CHANCES IN THE SHORT TERM
FORECAST...CONTINUE TO THINK CHANCES OF LIGHTNING ARE LOW. 19Z
AIRCRAFT SOUNDINGS FROM KDFW AND KDAL AIRPORTS CONTINUE TO SHOW
MID-LEVEL LAPSE RATES THAT ARE TOO STABLE TO SUPPORT FREE
CONVECTION. LAPSE RATES HAVE INCREASED A BIT FROM 12Z...LIKELY DUE
FROM DYNAMIC LIFT ASSOCIATED WITH A SHORTWAVE TROUGH LOCATED OVER
OKLAHOMA EARLY THIS AFTERNOON ACCORDING TO WATER VAPOR SATELLITE
IMAGERY. HOWEVER DUE TO THE POSITION OF THE SHORTWAVE
TROUGH...THINK THAT THE EFFECTS OF DYNAMIC LIFT ON OUR MID-LEVEL
LAPSE RATES HAVE ALREADY OCCURRED. AS A RESULT...LEFT
PRECIPITATION ALONG THE FRONT THUNDERSTORM FREE THROUGH TONIGHT.
WILL CERTAINLY CONTINUE TO MONITOR AIRCRAFT OBSERVATIONS THROUGH
THIS EVENING...AND WILL UPDATE THE FORECAST IF IT LOOKS LIKE
THUNDER IS BECOMING MORE LIKELY.
SATURDAY...THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE ENTIRE
FORECAST AREA BY SATURDAY MORNING...LEAVING COOLER AND MUCH DRIER
AIR IN PLACE ACROSS THE REGION. ALTHOUGH THE COLD FRONT DOES NOT
REPRESENT A STRONG CANADIAN AIRMASS...AFTER TODAY`S TEMPERATURES
IN THE MID TO UPPER 70S...IT WILL CERTAINLY BE NOTICEABLY COOLER
TOMORROW BEHIND THE FRONT. HIGHS ARE EXPECTED TO TOP OUT NEAR 60
DEGREES FOR MOST LOCATIONS...VERY CLOSE TO NORMAL HIGHS FOR THIS
TIME OF YEAR. BETWEEN LOW-LEVEL DRY AIR ADVECTION BEHIND THE FRONT
AND SHORTWAVE RIDGING ALOFT...MAINTAINED A DRY FORECAST FOR
SATURDAY.
SUNDAY...A RELATIVELY FAST MOVING SHORTWAVE TROUGH...CURRENTLY
LOCATED ABOUT 800 MILES WEST OF BAJA CALIFORNIA...IS EXPECTED TO
MOVE OVER THE SOUTHERN PLAINS SUNDAY AFTERNOON. WITH A LOW-LEVEL
COOL AIRMASS STILL IN PLACE ACROSS THE CWA BEHIND TODAY`S
FRONT...ALL MODEL GUIDANCE INDICATES THAT THIS SHORTWAVE TROUGH
WILL RESULT IN STRONG WARM AIR ADVECTION OVER THE CWA ON SUNDAY.
WARM AIR ADVECTION OVER THE COOL LOW-LEVEL AIRMASS DOES REPRESENT
PERSISTENT LIFT...HOWEVER PRECIPITATION PROSPECTS FOR THE REGION
LOOK VERY LIMITED AT THIS TIME. DESPITE NEARLY ALL MODELS SHOWING
THE PERSISTENT LIFT ON SUNDAY...THE PROSPECTS FOR MOISTURE RETURN
LOOK VERY LIMITED...AND FOCUSED ON LOCATIONS JUST WEST AND SOUTH
OF THE CWA. AS A RESULT...WENT AHEAD AND BUMPED POPS DOWN 10
PERCENT ACROSS THE ENTIRE AREA THROUGHOUT THE DAY ON SUNDAY.
THINK THAT OUR BEST CHANCES FOR LIGHT RAINFALL MAY BE WHEN THE
SHORTWAVE TROUGH MOVES DIRECTLY OVERHEAD SUNDAY AFTERNOON. MODELS
SHOW A BAND OF RELATIVELY STRONG MID-LEVEL FRONTOGENETIC FORCING
MOVING OVER THE CWA RIGHT OUT AHEAD OF THE SHORTWAVE ON SUNDAY.
THIS WILL LIKELY RESULT IN SOME ELEVATED PRECIPITATION...HOWEVER
THE LOW-LEVEL AIRMASS LOOKS DRY ENOUGH THAT MOST OF THIS SHOULD
EVAPORATE BEFORE REACHING THE SURFACE. AT ANY RATE...THE END
RESULT WAS THAT ISOLATED RAIN SHOWERS WERE INCLUDED IN THE
FORECAST EVEN WHERE POPS ARE AS LOW AS 10 PERCENT TO ACCOUNT FOR
THIS VIRGA/LIGHT RAIN POTENTIAL.
MONDAY INTO TUESDAY...IN GENERAL...A REINFORCING SHOT OF COOL AND
DRY AIR WILL BUILD INTO THE AREA BEHIND SUNDAY`S SHORTWAVE TROUGH
KEEPING US DRY ACROSS NORTH TEXAS FOR EARLY NEXT WEEK. THE LARGE
SCALE UPPER AIR PATTERN IS EXPECTED TO BE DOMINATED BY LARGE
TROUGHS OVER THE FAR EAST AND WEST COASTS...RESULTING IN BROAD
RIDGING OR NEARLY ZONAL FLOW OVER THE CENTRAL PORTION OF THE
COUNTRY. THIS PATTERN ALSO GENERALLY FAVORS DRY WEATHER FOR THE
CWA...HOWEVER PERSISTENT WESTERLY FLOW ALOFT OVER THE CONUS
ROCKIES WILL RESULT IN LEE-SIDE TROUGHING INCREASING IN INTENSITY
THROUGHOUT THE WEEK. WITH LEE-SIDE TROUGHING DEVELOPING AND A COOL
AIRMASS IN PLACE...WE WILL ONCE AGAIN HAVE A SITUATION WHERE WE
HAVE SOUTHERLY FLOW ALOFT IMPINGING ON A COOL LOW-LEVEL AIRMASS
NEAR THE SURFACE. THIS WILL RESULT IN PERSISTENT...ALBEIT
WEAK...LIFT AND MOISTURE RETURN BY TUESDAY AFTERNOON. BACKED OFF
ON POPS A BIT FROM THE PREVIOUS FORECAST ON TUESDAY...HOWEVER
MAINTAINED SOME 20 POPS OVER THE FAR WESTERN CWA TUESDAY
AFTERNOON...NEAREST TO THE LOW-LEVEL MOISTURE RETURN CONSISTENTLY
ADVERTISED IN MEDIUM RANGE GUIDANCE.
WEDNESDAY...MODELS ADVERTISE THAT THE UPPER LEVEL PATTERN WILL
AMPLIFY WITH RIDGING BUILDING OVER THE CONUS ROCKIES IN RESPONSE
TO A STRONG UPPER TROUGH BUILDING EASTWARD...FARTHER ON SHORE THE
WESTERN CONUS COAST. THIS RESULTS IN NORTHWEST FLOW ALOFT OVER THE
REGION ON WEDNESDAY...IN WHICH MODELS HAVE BEEN CONSISTENTLY
SENDING A STRONG BUT COMPACT SHORTWAVE TROUGH SOUTHEAST THROUGH
THE CWA OVER THE PAST COUPLE OF DAYS. THIS TROUGH IS EXPECTED TO
REMAIN WELL NORTH OF NORTH TEXAS...BUT SHOULD HELP SPREAD SOME OF
THE MOISTURE RETURN FROM WEST TEXAS EASTWARD OVER THE CWA ON
WEDNESDAY. IF MOISTURE DOES SPREAD EAST AS ADVERTISED AND LOW-
LEVEL WARM AIR ADVECTION AND ISENTROPIC LIFT CONTINUES... LIGHT
RAIN SHOWERS WILL LIKELY SPREAD ACROSS THE ENTIRE CWA ON
WEDNESDAY. BECAUSE LIFT IS EXPECTED TO REMAIN WEAK...RAIN SHOWERS
SHOULD BE SPOTTY/HIT-AND-MISS ON WEDNESDAY.
THURSDAY AND FRIDAY...MODELS INDICATE THAT LOW-LEVEL WARM AIR
ADVECTION PERSISTS...HOWEVER MODELS ARE ALSO BRINGING THE UPPER
LEVEL RIDGE OUT FROM THE CONUS ROCKIES AND OVER THE GREAT PLAINS
FOR THE LATTER PART OF THE WEEK. DESPITE PERSISTENT LOW-LEVEL
LIFT...WILL FAVOR THE UPPER LEVEL RIDGING IN THIS FORECAST AND
KEEP THURSDAY AND FRIDAY DRY FOR NOW AS MID AND UPPER LEVEL
FORCING SHOULD BE DOMINATED BY SUBSIDENCE.
NEXT WEEKEND...MODELS ARE DEFINITELY STRUGGLING WITH RUN TO RUN
AND MODEL TO MODEL CONSISTENCY WITH REGARDS TO THE EVOLUTION OF
THE STRONG WEST COAST UPPER TROUGH. HOWEVER...MODELS HAVE BEEN
CONSISTENTLY BRINGING THIS TROUGH OVER THE PLAINS NEXT
WEEKEND...WHICH MAY RESULT IN SOME DECENT RAIN CHANCES FOR THE
REGION. THIS IS CURRENTLY BEYOND THE VALID FORECAST PERIOD...BUT
IT IS A SYSTEM THAT WE WILL BE KEEPING A CLOSE EYE ON IN THE
COMING DAYS.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 50 61 44 57 43 / 10 5 5 10 10
WACO, TX 51 63 46 57 43 / 30 10 10 20 20
PARIS, TX 49 60 42 56 39 / 30 10 5 10 10
DENTON, TX 46 60 42 56 41 / 10 5 5 10 5
MCKINNEY, TX 48 60 42 57 40 / 20 5 5 10 10
DALLAS, TX 50 61 45 56 44 / 20 5 5 10 10
TERRELL, TX 52 62 44 58 40 / 30 5 5 10 10
CORSICANA, TX 53 63 45 59 43 / 30 10 10 20 20
TEMPLE, TX 50 64 46 58 44 / 30 10 10 20 20
MINERAL WELLS, TX 44 60 42 56 42 / 10 5 10 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/91
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1138 PM CST WED DEC 3 2014
.UPDATE...
PLEASE SEE 06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
WIDESPREAD MVFR CONDITIONS ONGOING WITH EXPECTED DETERIORATION TO
IFR AND PERIODIC LIFR TO VLIFR ALSO POSSIBLE TOWARDS DAWN DUE TO
LOW CIGS AND REDUCED VISIBILITIES. KSAT/KSSF HAVE GREATEST
LIKELIHOOD OF SOME DENSE FOG 12-14Z WITH KAUS SLIGHTLY LESS WITH
VIS DROPS TO 1SM POSSIBLE. KDRT VIS MAY STAY HIGHER THEN MOST
SITES DUE TO STRONGER WINDS BUT CIGS SHOULD STILL DROP TO LESS
THAN 500FT. PERIODIC LIGHT DRIZZLE WILL ALSO BE LIKELY THROUGH THE
OVERNIGHT. ONLY MARGINAL IMPROVEMENT EXPECTED THROUGH DAY THURSDAY
TO MVFR WITH A NEAR REPEAT OF FALLING CATEGORIES THURSDAY NIGHT
INTO FRIDAY. /ALLEN/
&&
.PREV DISCUSSION... /ISSUED 1001 PM CST WED DEC 3 2014/
UPDATE... /SLIGHTLY WARMER MIN TEMPS SE/
DEW POINTS ARE HOVERING AROUND 60 OVER THE COASTAL PRAIRIES...AND
THE HRRR SUGGESTS WARMER MIN TEMPERATURES THAT MATCH UP WELL WITH
OBSERVATIONAL TRENDS. THUS WILL RAISE MINS A FEW DEGREES FOR
TONIGHT OVER THE COASTAL PRAIRIES. THE REST OF THE OBSERVATIONAL
TRENDS LOOK ON TRACK. AREAS OF DENSE FOG WILL REMAIN A
POSSIBILITY...BUT WITH A LOT OF VARIETY IN VISIBILITIES THIS
EVENING FROM ONE AREA TO THE NEXT...WILL NOT PLAN ON ANY NPW
ISSUANCES FOR THE NEXT FEW HOURS.
PREV DISCUSSION... /ISSUED 345 PM CST WED DEC 3 2014/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
SOME BREAKS IN THE CLOUD COVER CAN BE OBSERVED ACROSS SOUTH
CENTRAL TEXAS LATE THIS AFTERNOON. HOWEVER...MOST OF THE REGION
CONTINUES TO REMAIN OVERCAST. TEMPERATURES HAVE WARMED INTO THE
LOW 60S TO NEAR 70 IN AREAS WHERE SKIES HAVE PARTIALLY CLEARED.
ELSEWHERE... TEMPERATURES REMAIN IN THE 50S. CLOUD COVER WILL
THICKEN OVERNIGHT AS WARM AIR ADVECTION IN THE LOW-LEVELS
CONTINUES. WE EXPECT FOG AND DRIZZLE TO BECOME WIDESPREAD
TONIGHT... ESPECIALLY ALONG AND WEST OF THE ESCARPMENT. CAN/T RULE
OUT THE POSSIBILITY OF DENSE FOG FOR AREAS NORTH OF A ROCKSPRINGS
TO UVALDE TO SAN ANTONIO TO AUSTIN LINE. WE/LL MENTION FOG
BECOMING WIDESPREAD IN THE HAZARDOUS WEATHER OUTLOOK FOR TONIGHT.
LATER SHIFTS MAY NEED TO ISSUE A DENSE FOG ADVISORY PENDING
OBSERVATIONAL TRENDS AND 00Z MODEL GUIDANCE. FOG IS LIKELY TO
CONTINUE WELL INTO THURSDAY MORNING GIVEN CONTINUED MOISTENING OF
THE LOW-LEVELS. OTHERWISE...TEMPERATURES WILL WARM ON THURSDAY...
BUT WE DID UNDERCUT GUIDANCE SLIGHTLY IN AREAS WHERE CLOUD COVER
IS LIKELY TO LINGER THROUGH THE AFTERNOON HOURS.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
CLOUD COVER REMAINS PLENTIFUL INTO FRIDAY...ALTHOUGH SOME BREAKS
ARE EXPECTED WEST OF I-35 DURING THE AFTERNOON. WE/LL CONTINUE TO
MENTION A 20-30% CHANCE FOR RAIN AS THE SOUTHERN PERIPHERY OF AN
UPPER LEVEL TROUGH TRAVERSES THE AREA. CAN/T COMPLETELY RULE OUT
A THUNDERSTORM OR TWO AS TEMPERATURES WARM INTO THE 70S...BUT ONLY
ISOLATED STORMS EXPECTED. A COLD FRONT WILL MOVE THROUGH ON
SATURDAY AND THIS WILL KNOCK TEMPERATURES BACK DOWN CLOSER TO
CLIMATOLOGICAL NORMALS FOR SATURDAY THROUGH MONDAY. WE/LL ALSO
CONTINUE TO MENTION A 20-40% CHANCE FOR SHOWERS THROUGH THE
WEEKEND INTO EARLY NEXT WEEK ACROSS MOST AREAS AS THE COLD FRONT
AND AN UPPER LEVEL TROUGH SHOULD BE ENOUGH TO GIN UP SOME SHOWERS.
LATE IN THE FORECAST PERIOD...THE OPERATIONAL GFS AND ECMWF
CONTINUE TO DIFFER WITH REGARDS TO THE NEXT COLD FRONT DURING THE
EARLY/MIDDLE PORTION OF THE UPCOMING WEEK. THE ECMWF SHOWS MUCH
DRIER AIR FILTERING IN FROM THE NORTH ON TUESDAY AND WEDNESDAY
WHILE THE GFS KEEPS THE DRIER AIR FARTHER EAST OF OUR REGION. THE
GFS DOES SHOW THE MOIST AXIS BEGINNING TO FOCUS ACROSS OUR WESTERN
ZONES AND WE/LL BEGIN SHIFT RAIN CHANCES INTO THE WESTERN HILL
COUNTRY... SOUTHERN EDWARDS PLATEAU AND RIO GRANDE PLAINS ON
TUESDAY. WE COULD SEE RAIN CHANCES LINGER INTO WEDNESDAY AS YET
ANOTHER UPPER LEVEL SYSTEM MOVES IN FROM THE NORTHWEST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 58 67 61 74 57 / 20 20 30 30 20
AUSTIN BERGSTROM INTL AIRPORT 57 68 61 74 57 / 20 20 30 30 20
NEW BRAUNFELS MUNI AIRPORT 58 68 62 75 58 / 20 20 20 30 20
BURNET MUNI AIRPORT 55 65 58 73 52 / 20 20 30 30 20
DEL RIO INTL AIRPORT 57 67 58 73 54 / 10 10 20 10 10
GEORGETOWN MUNI AIRPORT 56 66 60 73 55 / 20 20 30 30 20
HONDO MUNI AIRPORT 56 67 60 73 56 / 20 20 20 20 20
SAN MARCOS MUNI AIRPORT 58 68 61 74 57 / 20 20 20 30 20
LA GRANGE - FAYETTE REGIONAL 59 70 62 75 60 / 20 20 20 30 30
SAN ANTONIO INTL AIRPORT 57 68 63 74 59 / 20 20 20 20 20
STINSON MUNI AIRPORT 58 69 62 75 60 / 20 20 20 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...15
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1122 PM CST WED DEC 3 2014
.AVIATION...
/06Z TAFS/
CONCERNS...CIGS WILL LOWER INTO IFR/LIFR CATEGORY OVERNIGHT AND
AGAIN THURSDAY NIGHT.
CONDITIONS AT THE TAF SITES ARE EXPECTED TO DETERIORATE OVERNIGHT
AS MOISTURE CONTINUES TO INCREASE ACROSS THE REGION. EXPECT THE
TAF SITES TO BE IN LOW IFR OR LIFR CATEGORY BY 10-11Z AND REMAIN
THERE THROUGH MOST OF THE MORNING HOURS. THE CATEGORY REDUCTIONS WILL
BE DUE TO A COMBINATION OF LOW CIGS...FOG...AND DRIZZLE. LIGHT
RAIN MAY BRIEFLY AFFECT ANY OF THE TAF SITES THROUGH THE OVERNIGHT
AND THURSDAY MORNING HOURS. CONDITIONS WILL SLOWLY IMPROVE TO MVFR
CATEGORY THURSDAY AFTERNOON BUT RETURN BELOW 2 KFT IN THE
EVENING HOURS AND THEN FALL BELOW 1 KFT DURING THE OVERNIGHT HOURS
WITH FOG AND DRIZZLE RETURNING.
82/JLD
&&
.UPDATE...
WIDESPREAD FOG CONTINUES TO REDUCE VISIBILITIES INTO THE 1 TO 3
MILE RANGE ALONG AND NORTH OF A BOWIE TO GREENVILLE TO SULPHUR
SPRINGS LINE THIS EVENING. EXPECT ADDITIONAL AREAS OF FOG TO
DEVELOP ACROSS THE FORECAST AREA OVERNIGHT. A WEAK FRONTAL
BOUNDARY EXTENDS NORTH OF A GRAHAM TO MCKINNEY TO QUITMAN LINE
WITH LIGHT EAST TO NORTHEAST WINDS TO THE NORTH OF THE BOUNDARY
AND LIGHT SOUTHEASTERLY WINDS TO THE SOUTH. THE RAP STALLS THIS
BOUNDARY THIS EVENING AND THEN LIFTS IT INTO SOUTHERN OKLAHOMA
BEFORE DAYBREAK. THERE IS A POTENTIAL FOR SOME LOCALLY DENSE FOG
ALONG THE RED RIVER COUNTIES. FOR NOW HAVE PLACED 3/4SM FOG IN THE
GRIDS FOR THOSE AREAS...AND WILL MONITOR THE POTENTIAL FOR DENSE
FOG. HAVE LOWERED POPS KEEPING THE HIGHEST CHANCES OVERNIGHT...30
TO 40 PERCENT ALONG THE RED RIVER...WITH 20S ACROSS MOST OF THE
REST OF THE AREA. UPDATES HAVE BEEN SENT.
58
&&
.PREV DISCUSSION... /ISSUED ISSUED BY NATIONAL WEATHER SERVICE SHREVEPORT LA/
CLOUDS HANGING TOUGH TODAY BUT SOME BREAKS WERE NOTED WEST OF AN
RPH...COM LINE LATE THIS AFTERNOON. WHERE THESE BREAKS WERE
OCCURRING...TEMPERATURES HAD WARMED INTO THE MID TO UPPER 60S OUT
NEAR ABI AND SJT. CLOSER TO HOME...LOWER 60S WERE COMMON ACROSS OR
SOUTHERN ZONES WITH NEAR TO LOWER 50S ALONG THE RED RIVER ALONG
OUR RESIDUAL FRONTAL BOUNDARY.
THIS BOUNDARY HAS SHOWN A TENDENCY TO PIVOT SLOWLY SOUTHWARD...`
ESPECIALLY ALONG THE UPPER RED RIVER VALLEY AS TEMPERATURES HAVE
SLOWLY FALLEN ALL DAY ALONG AND NORTH OF A CDS TO FDR LINE. SHORT
TERM PROGS HAVE A GOOD HANDLE ON THIS BOUNDARY CONTINUING TO
SLOWLY SINK SOUTHWARD TOWARDS THE I-20 CORRIDOR NEAR AND WEST OF
ABI...BUT PIVOTING SLOWLY BACK NORTH OF THE RED RIVER EAST OF GYI
LATE TONIGHT. THIS WILL KEEP MUCH OF OUR CWA UNDER THE INFLUENCE
OF CONTINUED WAA AND LOW LEVEL CONDENSATION PRESSURE DEFICITS
SUPPORT THE POSSIBILITY OF DRIZZLE AND/OR THE DEVELOPMENT OF
PATCHY FOG. SLIGHTLY INCREASED LIFT ALONG AND NORTH OF THE I-30
CORRIDOR WILL SUPPORT A LITTLE INCREASED CHANCE OF PRECIPITATION
OVERNIGHT AS WELL.
NEARLY ZONAL UPPER FLOW OVERNIGHT THROUGH EARLY THURSDAY WILL
BECOME MORE WSW AS THE FIRST IN A SERIES OF DISTURBANCES MOVES OUT
OF THE FOUR CORNER REGION AND INTO THE HILL COUNTRY/SOUTHERN
PLAINS. SHOULD SEE INCREASED CHANCES OF PRECIPITATION...SOME OF
THAT CONVECTIVE IN NATURE LATE ON THURSDAY...BUT ESPECIALLY THU
NIGHT INTO EARLY FRI BEFORE THE PRECIPITATION MOVES EAST OF THE
REGION ON SAT. WEAK RIDGING COMMENCES FOR SATURDAY BUT YET ANOTHER
SHORTWAVE WILL APPROACH THE REGION SATURDAY NIGHT INTO SUNDAY.
MOISTURE RETURN MAY BE A PROBLEM WITH SUNDAY`S SYSTEM BUT CHANCE
POPS ARE WARRANTED FOR AT LEAST OUR SW HALF ATTM. REALLY NOT
SEEING ANY INTRUSIONS OF VERY COLD AIR THROUGH THE FORECAST PERIOD
AND FOR THAT MATTER...THROUGH THE NEXT 10 DAYS. IF THE ECMWF IS TO
BE BELIEVED...A BLOCKING RIDGE OF HIGH PRESSURE ALOFT BUILDS INTO
THE PLAINS BY THE END OF NEXT WEEK WHICH IS A DRY AND STABLE
PATTERN FOR NORTH TEXAS WITH NEAR SEASONABLE TEMPERATURES.
PRELIM TO FOLLOW...99.
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 53 65 58 73 52 / 20 20 40 40 30
WACO, TX 54 67 58 73 51 / 20 20 30 30 30
PARIS, TX 48 61 54 68 52 / 40 30 50 50 40
DENTON, TX 52 64 55 72 47 / 20 30 40 40 30
MCKINNEY, TX 52 63 55 71 49 / 20 30 40 50 30
DALLAS, TX 53 65 59 72 52 / 20 20 40 40 30
TERRELL, TX 53 67 57 71 52 / 20 20 40 50 40
CORSICANA, TX 53 69 58 72 54 / 20 20 30 40 30
TEMPLE, TX 54 68 57 73 52 / 10 20 30 30 20
MINERAL WELLS, TX 53 65 55 72 47 / 20 20 30 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/58
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
111 PM EST THU DEC 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTHWARD ACROSS THE PIEDMONT TO WEDGE
AGAINST THE EASTERN FACE OF THE APPALACHIANS. A SERIES OF UPPER
LEVEL DISTURBANCES WILL PASS ACROSS THE REGION THROUGH TONIGHT. A
DEEP LOW PRESSURE SYSTEM WILL PASS ACROSS THE AREA
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EST THURSDAY...
RADAR SHOWING RAIN...MAYBE SOME SLEET MOVING ACROSS THE MTNS OF SW
VA INTO WV. THE LATEST HRRR AND 12Z RNK WRF HANDLING THIS WELL.
THIS IS ASSOCIATED WITH SHORTWAVE PASSING ACROSS KY AND INVERTED
TROUGH ACROSS THE SRN APPALACHIANS.
INCREASING TIMING FOR RAIN TO THE NORTH AND EAST...WITH INCREASING
POPS. AMOUNTS WILL BE UNDER A QUARTER INCH...WITH THE HIGHER
AMOUNTS OVER THE MTNS. NOT REALLY EXPECTING ANY FROZEN/FREEZING
ISSUES THIS AFTERNOON AS TEMPS STAY IN THE UPPER 30S NORTHWEST TO
MID 50S SOUTHEAST. WILL CONTINUE TO MAKE ADJUSTMENTS INTO
TONIGHT/FRIDAY...AS MODELS SHOWING LESS THREAT OF PRECIP TO THE
SRN CWA WITH MAIN BATCH ARRIVING ACROSS CENTRAL WV INTO THE
ALLEGHANY HIGHLANDS AND SHENANDOAH VALLEY OVERNIGHT. WINTER WX
HEADLINES MAY BE NEEDED FOR BATH COUNTY...BUT WILL LOOK MORE INTO
THIS AS WE HEAD INTO 3-4 PM ISSUANCE OF FORECAST.
PREVIOUS VALID DISCUSSION...
POCKETS OF MIXED PRECIPITATION STILL APPEAR LIKELY BEGINNING AS
EARLY AS 8 PM THIS EVENING IN THE VICINITY OF THE INTERSTATE 64
CORRIDOR. THE HIGH PRESSURE WEDGE WILL CONTINUE TO STRENGTHEN
THROUGH THE NIGHT...FORCING INCREASINGLY COLDER AIR INTO OUR AREA
FOR THE RAIN TO FALL INTO. WHILE TEMPERATURES WILL REMAIN WARM
ENOUGH MOST LOCATIONS THAT PRECIPITATION WILL REMAIN LIQUID...SOME
OF THE RIDGELINES WILL BE TRAPPED IN THE SUB-FREEZING AIR THAT
MOVES IN LATE TONIGHT. IN THESE LOCATIONS...WILL START OFF WITH A
FEW AREAS OF SLEET...WHICH WILL TRANSITION TO LIGHT FREEZING RAIN
TOWARD DAWN ON FRIDAY. ICING ACCUMULATIONS ARE EXPECTED TO BE
LIGHT AND SPOTTY...GENERALLY LESS THAN A TENTH OF AN INCH...AND
MAINLY ON ELEVATED OBJECTS...ALTHOUGH ROADS MAY BECOME SLICK IN A
FEW SPOTS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EST THURSDAY...
COLD AIR WILL BE DAMMED AGAINST THE EASTERN SLOPES OF THE
APPALACHIANS FRIDAY PER 1040 MB SURFACE HIGH OVER NEW ENGLAND.
THIS AIRMASS WILL BE HARD TO DISPLACE...LEAVING US WITH A COOL
CLOUDY DAY REINFORCED BY AN EAST OR NORTHEAST WIND. ABOVE THE
WEDGE OF COOL AIR...WINDS WILL BE OUT OF THE
SOUTHWEST...WARM/MOIST AIR BEING DRAWN NORTHEAST FROM THE GULF OF
MEXICO. 850 TEMPS ARE PROGGED TO BE IN THE +6 TO +8 DEG C
RANGE...SO HYDROMETEORS SHOULD FALL AS LIQUID. ANY P-TYPE ISSUES
WILL BE EARLY FRIDAY MORNING PER SURFACE TEMPERATURES NEAR 32
DEGREES IN THE NORTHEASTERN CWA...VA/WV HIGHLANDS AND THE BLUE
RIDGE PARKWAY NORTHEAST OF ROANOKE...WITH POCKETS OF FREEZING RAIN
RESULTING IN SOME LIGHT ICE ACCRETIONS MAINLY IN THE TREES AND ON
ELEVATED SURFACES. ASIDE FROM THIS PTYPE ISSUE IN THE MORNING...NO
SIGNIFICANT CONCERNS NOTED FOR THE AFTERNOON WITH JUST A CONTINUED
THREAT FOR LIGHT RAIN OR DRIZZLE.
MODEL TEMPERATURE GUIDANCE HAS FINALLY COME AROUND TO RECOGNIZING
THE COLD WEDGE FRIDAY...KEEPING ALL AREAS...WITH THE EXCEPTION OF
AREAS WEST OF THE APPALACHIAN DIVIDE...ANCHORED IN THE 30S/40S
THROUGHOUT THE DAY.
WEDGE IS EXPECTED TO HOLD THROUGH FRIDAY NIGHT WITH COOL BUT STEADY
TEMPERATURES. WENT WITH THE COOLER MET/NAM GUIDANCE...HOLDING OFF
ON ANY MIX DOWN OF WARM AIR ALOFT UNTIL SATURDAY. FORECAST MODELS
ARE GENERALLY TOO AGGRESSIVE MIXING OUT THE COOL WEDGE...AND GIVEN
THE STRENGTH OF THE SFC HIGH OVER NEW ENGLAND SEE NO REASON TO
DEVIATE.
OTHER THAN SOME WEAK ISENTROPIC LIFT FRIDAY AFTERNOON AND FRIDAY
NIGHT...ANY PRECIP SHOULD BE LIGHT...IN THE FORM OF LIGHT RAIN OR
DRIZZLE...QPF LESS THAN A QUARTER OF AN INCH FRIDAY/FRIDAY NIGHT.
BY SATURDAY...DYNAMIC LIFT WILL INCREASE YIELDING HIGHER
PRECIPITATION RATES PER DEVELOPMENT AND PROGRESSION OF LOW PRESSURE
WHICH WILL PASS OVER/NEAR THE AREA. MODELS ARE IN GENERAL AGREEMENT
THAT SHORT WAVE ENERGY EXITING THE SOUTHWEST CONUS COURTESY OF AN
ACTIVE SOUTHERN JET STREAM WILL RESULT IN THE DEVELOPMENT OF LOW
PRESSURE OVER THE MID MS VALLEY FRIDAY NIGHT...THIS LOW
STRENGTHENING AS IT GAINS LATITUDE...MOVING FROM PADUCAH KY FRIDAY
NIGHT TO NEAR PITTSBURGH PA SATURDAY MORNING. AS THE LOW PASSES
NORTH OF OUR REGION...A COLD FRONT TRAILING SOUTH FROM THE LOW WILL
MOVE EAST ACROSS KY/TN...CROSSING THE APPALACHIAN MOUNTAINS
SATURDAY...AND THEN MOVE EAST AND OFF THE COAST SATURDAY NIGHT.
WIDESPREAD RAIN IS EXPECTED TO ACCOMPANY THESE FEATURES WITH A
GENERAL HALF INCH /0.50/ TO ONE INCH /1.00/ OF RAINFALL ACROSS THE
CWA...THE HEAVIER AMOUNTS OCCURRING ACROSS THE NORTHWESTERN
CWA...STATE IF WV...CLOSER TO THE SURFACE LOW.
WARM SOUTHWEST WINDS AHEAD OF THE FRONT ARE EXPECTED TO DISPLACE THE
COOL WEDGE EAST OF THE MOUNTAINS...BUT SIMILAR TO THE LAST
EVENT...THIS COOL AIR WILL BE VERY STUBBORN TO DISPLACE RIGHT
AGAINST THE LEE SLOPE OF THE BLUE RIDGE UNTIL THE FRONT IS RIGHT ON
TOP OF THE FORECAST AREA. AS A RESULT...AREAS WEST OF THE BLUE RIDGE
WILL WARM EARLY SATURDAY...FOLLOWED BY THE PIEDMONT...THESE AREAS
TESTING 50 DEGREES EARLY. THE NARROW STRIP OF COUNTIES AGAINST THE
EASTERN SLOPE OF THE BLUE RIDGE...MWK-MTV-LYH-CHO LINE...WILL MOST
LIKELY HOLDING OFF UNTIL LATE SATURDAY AFTERNOON B4 MIXING.
PASSAGE OF THE FRONT WILL OF COURSE BEGIN ANOTHER COOL DOWN
PROCESS...COLD AIR ADVECTION PUTTING A DRAG ON THE TEMPERATURE IN
THE MOUNTAINS LATE SATURDAY AFTERNOON...FOLLOWED BY AN AREAWIDE COOL
DOWN SATURDAY NIGHT...TEMPERATURES DIPPING BACK INTO THE 30S AS THE
RAIN TAPERS FROM WEST TO EAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 1230 PM EST WEDNESDAY...
12Z SUNDAY A SURFACE LOW IS WELL OFF THE COAST...MEANWHILE A SURFACE
HIGH IS OVER SOUTHERN QUEBEC. THIS WILL ONCE AGAIN WEDGE THE AREA
INTO A N/NE FLOW FOR SUNDAY AND MOST OF MONDAY. THE 12Z GFS IS MUCH
DRIER THAN PREVIOUS RUNS BUT STILL LEFT LOW CHANCE POPS IN. MONDAY A
LOW PRESSURE SYSTEM ACROSS WESTERN ONTARIO WILL DRIFT TOWARDS
SOUTHERN QUEBEC THROUGHOUT THE DAY. A TRAILING COLD FRONT WILL SWING
THROUGH OUR REGION MONDAY NIGHT AND INTO TUESDAY. THIS WILL INCREASE
THE CHANCE OF SHOWERS ACROSS THE MOUNTAINS AND SOME SNOW SHOWERS AT
THE HIGHER ELEVATIONS.
FLOW BECOMES NORTHWEST AFTER THE FRONTAL PASSAGE AND HIGH PRESSURE
STARTS TO BUILD IN FOR THE REMAINDER OF THE WEEK. LEFT LOW CHANCE
POPS IN ACROSS THE FAVORED UPSLOPE REGIONS...HOWEVER MOISTURE LOOKS
LIMITED AS OF THE LATEST GFS RUN.
TEMPS DURING THE PERIOD WILL RUN A FEW DEGREES BELOW NORMAL...MAINLY
LOOKING AT LOW TO MID 40S ACROSS THE MOUNTAINS AND NEAR 50 ACROSS
THE PIEDMONT.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1230 PM EST THURSDAY...
CIGS WILL BE LOWERING FASTER THAN EARLIER THOUGH DESPITE THE DRIER
AIRMASS IN THE EAST. WILL SEE RAIN WITH MVFR CIGS IN THE MTNS TO
VFR EAST. RAIN WILL REACH ROA/BCB BY 18-20Z...AND LYH BY 21Z.
DANVILLE WILL BE ON THE EDGE OF RAINFALL AND LOWER CIGS...BUT
LOOKS LIKE MVFR CIGS WILL BE ATTAINED BY DUSK TODAY...AROUND 3KFT.
THE WORST FLYING WX THROUGH TONIGHT WILL BE IN THE NRN FORECAST
AREA FROM LYH TO LWB/BLF. THINK CIGS WILL TANK BELOW 1KFT BY
EARLY EVENING IN THE MTNS...AND ROANOKE BY 03Z...LYH BY 08Z. THE
PRECIPITATION WILL BE MAINLY -RA TO MODERATE RAIN. SOME PL OR FZRA
NOT OUT OF THE QUESTION AT LWB...BUT OVERALL MODEL SHOWING THIS
THREAT FURTHER NORTH TOWARD HSP TO EKN. VSBYS WILL STAY IN THE
IFR/MVFR RANGE OVERALL.
THESE CONDITIONS WILL SLOWLY IMPROVE TO MVFR LATE IN THE PERIOD
EXCEPT LWB WHERE THINK IT STAY IFR INTO FRI AFTERNOON.
EXTENDED DISCUSSION...
HIGH PRESSURE WEDGE WILL PERSIST FRIDAY AFTERNOON INTO SATURDAY...
WITH LINGERING MVFR CEILINGS MOST SPOTS AS WELL AS SPOTTY -RA OR
-DZ ESPECIALLY THE MOUNTAINS INTO SATURDAY MORNING. LOW PRESSURE
FORECAST TO TRACK ACROSS THE CENTRAL APPALACHIANS TO VA COAST BY
SAT EVENING WILL CLEAR THE WEDGE OUT BUT EXPECT SUB VFR CIGS AND
AT TIME VSBYS WITH RAIN TO STAY AROUND SATURDAY...ENDING BY SAT
NIGHT.
AIRMASS DRIES OUT SUNDAY AS HIGH PRESSURE MOVES BACK IN FROM THE
NORTH. THIS HIGH WILL SET UP ANOTHER WEDGE BY MONDAY BUT NO PRECIP
IS EXPECTED UNTIL MON NIGHT-TUESDAY WHEN CIGS/VSBYS WILL FALL
UNDER VFR AGAIN.
&&
.EQUIPMENT...
AS OF 500 AM EST THURSDAY...
VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...IS WORKING IN A
DEGRADED MODE. PARTS WILL BE IN BY EARLY NEXT WEEK...THEN REPAIRS
CAN BE COMPLETED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF/WP
NEAR TERM...NF/WP
SHORT TERM...PM
LONG TERM...CF
AVIATION...NF/WP
EQUIPMENT...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1010 AM EST THU DEC 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTHWARD ACROSS THE PIEDMONT TO WEDGE
AGAINST THE EASTERN FACE OF THE APPALACHIANS...BRINGING COLDER AIR
INTO THE REGION THIS AFTERNOON. A SERIES OF UPPER LEVEL
DISTURBANCES WILL PASS ACROSS THE REGION THIS EVENING AND
TONIGHT...BRINGING RAIN FOR MOST LOCATIONS...AND POCKETS OF
FREEZING RAIN TO THE HIGHER RIDGES ALONG THE INTERSTATE 64
CORRIDOR...SOUTH ALONG THE BLUE RIDGE PARKWAY. A DEEP LOW PRESSURE
SYSTEM WILL PASS ACROSS THE AREA SATURDAY...BRINGING WIDESPREAD
RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EST THURSDAY...
HAVE UPDATED FORECAST TO SPEED UP TIMING OF RAIN IN THE MOUNTAIN
EMPIRE. THE 13Z HRRR WAS HANDLING THE SPOTTY RAIN ON RADAR IN FAR
SW VA/SE KY THIS MORNING AND EXPECT SLIGHT TO LOW CHANCE POPS IN
THE FAR WEST BY MIDDAY WITH RAIN REACHING THE NEW RIVER VALLEY BY
1 TO 3 PM. MAINLY IT WILL BE LIGHT IN INTENSITY. 12Z RNK SOUNDING
VERY DRY THIS MORNING WITH THIS BATCH OF RAIN HELPING TO LOWER THE
CLOUD DECK BY LATE IN THE DAY.
REST OF THE FORECAST THROUGH THIS AFTERNOON LOOKS ON TRACK FROM
EARLIER FORECAST.
PREVIOUS VALID DISCUSSION...
INCREASING CLOUDS AND WEDGING TODAY WILL LIMIT HEATING...AND HAVE
UNDERCUT MODEL GUIDANCE BY 2 TO 4 DEGREES FOR AFTERNOON
TEMPERATURES...WITH HIGHS HOLDING IN THE LOW 50S ACROSS THE NORTH
CAROLINA PIEDMONT...AND IN THE 40S FURTHER NORTH.
POCKETS OF MIXED PRECIPITATION STILL APPEAR LIKELY BEGINNING AS
EARLY AS 8 PM THIS EVENING IN THE VICINITY OF THE INTERSTATE 64
CORRIDOR. THE HIGH PRESSURE WEDGE WILL CONTINUE TO STRENGTHEN
THROUGH THE NIGHT...FORCING INCREASINGLY COLDER AIR INTO OUR AREA
FOR THE RAIN TO FALL INTO. WHILE TEMPERATURES WILL REMAIN WARM
ENOUGH MOST LOCATIONS THAT PRECIPITATION WILL REMAIN LIQUID...SOME
OF THE RIDGELINES WILL BE TRAPPED IN THE SUB-FREEZING AIR THAT
MOVES IN LATE TONIGHT. IN THESE LOCATIONS...WILL START OFF WITH A
FEW AREAS OF SLEET...WHICH WILL TRANSITION TO LIGHT FREEZING RAIN
TOWARD DAWN ON FRIDAY. ICING ACCUMULATIONS ARE EXPECTED TO BE
LIGHT AND SPOTTY...GENERALLY LESS THAN A TENTH OF AN INCH...AND
MAINLY ON ELEVATED OBJECTS...ALTHOUGH ROADS MAY BECOME SLICK IN A
FEW SPOTS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EST THURSDAY...
COLD AIR WILL BE DAMMED AGAINST THE EASTERN SLOPES OF THE
APPALACHIANS FRIDAY PER 1040 MB SURFACE HIGH OVER NEW ENGLAND.
THIS AIRMASS WILL BE HARD TO DISPLACE...LEAVING US WITH A COOL
CLOUDY DAY REINFORCED BY AN EAST OR NORTHEAST WIND. ABOVE THE
WEDGE OF COOL AIR...WINDS WILL BE OUT OF THE
SOUTHWEST...WARM/MOIST AIR BEING DRAWN NORTHEAST FROM THE GULF OF
MEXICO. 850 TEMPS ARE PROGGED TO BE IN THE +6 TO +8 DEG C
RANGE...SO HYDROMETEORS SHOULD FALL AS LIQUID. ANY P-TYPE ISSUES
WILL BE EARLY FRIDAY MORNING PER SURFACE TEMPERATURES NEAR 32
DEGREES IN THE NORTHEASTERN CWA...VA/WV HIGHLANDS AND THE BLUE
RIDGE PARKWAY NORTHEAST OF ROANOKE...WITH POCKETS OF FREEZING RAIN
RESULTING IN SOME LIGHT ICE ACCRETIONS MAINLY IN THE TREES AND ON
ELEVATED SURFACES. ASIDE FROM THIS PTYPE ISSUE IN THE MORNING...NO
SIGNIFICANT CONCERNS NOTED FOR THE AFTERNOON WITH JUST A CONTINUED
THREAT FOR LIGHT RAIN OR DRIZZLE.
MODEL TEMPERATURE GUIDANCE HAS FINALLY COME AROUND TO RECOGNIZING
THE COLD WEDGE FRIDAY...KEEPING ALL AREAS...WITH THE EXCEPTION OF
AREAS WEST OF THE APPALACHIAN DIVIDE...ANCHORED IN THE 30S/40S
THROUGHOUT THE DAY.
WEDGE IS EXPECTED TO HOLD THROUGH FRIDAY NIGHT WITH COOL BUT STEADY
TEMPERATURES. WENT WITH THE COOLER MET/NAM GUIDANCE...HOLDING OFF
ON ANY MIX DOWN OF WARM AIR ALOFT UNTIL SATURDAY. FORECAST MODELS
ARE GENERALLY TOO AGGRESSIVE MIXING OUT THE COOL WEDGE...AND GIVEN
THE STRENGTH OF THE SFC HIGH OVER NEW ENGLAND SEE NO REASON TO
DEVIATE.
OTHER THAN SOME WEAK ISENTROPIC LIFT FRIDAY AFTERNOON AND FRIDAY
NIGHT...ANY PRECIP SHOULD BE LIGHT...IN THE FORM OF LIGHT RAIN OR
DRIZZLE...QPF LESS THAN A QUARTER OF AN INCH FRIDAY/FRIDAY NIGHT.
BY SATURDAY...DYNAMIC LIFT WILL INCREASE YIELDING HIGHER
PRECIPITATION RATES PER DEVELOPMENT AND PROGRESSION OF LOW PRESSURE
WHICH WILL PASS OVER/NEAR THE AREA. MODELS ARE IN GENERAL AGREEMENT
THAT SHORT WAVE ENERGY EXITING THE SOUTHWEST CONUS COURTESY OF AN
ACTIVE SOUTHERN JET STREAM WILL RESULT IN THE DEVELOPMENT OF LOW
PRESSURE OVER THE MID MS VALLEY FRIDAY NIGHT...THIS LOW
STRENGTHENING AS IT GAINS LATITUDE...MOVING FROM PADUCAH KY FRIDAY
NIGHT TO NEAR PITTSBURGH PA SATURDAY MORNING. AS THE LOW PASSES
NORTH OF OUR REGION...A COLD FRONT TRAILING SOUTH FROM THE LOW WILL
MOVE EAST ACROSS KY/TN...CROSSING THE APPALACHIAN MOUNTAINS
SATURDAY...AND THEN MOVE EAST AND OFF THE COAST SATURDAY NIGHT.
WIDESPREAD RAIN IS EXPECTED TO ACCOMPANY THESE FEATURES WITH A
GENERAL HALF INCH /0.50/ TO ONE INCH /1.00/ OF RAINFALL ACROSS THE
CWA...THE HEAVIER AMOUNTS OCCURRING ACROSS THE NORTHWESTERN
CWA...STATE IF WV...CLOSER TO THE SURFACE LOW.
WARM SOUTHWEST WINDS AHEAD OF THE FRONT ARE EXPECTED TO DISPLACE THE
COOL WEDGE EAST OF THE MOUNTAINS...BUT SIMILAR TO THE LAST
EVENT...THIS COOL AIR WILL BE VERY STUBBORN TO DISPLACE RIGHT
AGAINST THE LEE SLOPE OF THE BLUE RIDGE UNTIL THE FRONT IS RIGHT ON
TOP OF THE FORECAST AREA. AS A RESULT...AREAS WEST OF THE BLUE RIDGE
WILL WARM EARLY SATURDAY...FOLLOWED BY THE PIEDMONT...THESE AREAS
TESTING 50 DEGREES EARLY. THE NARROW STRIP OF COUNTIES AGAINST THE
EASTERN SLOPE OF THE BLUE RIDGE...MWK-MTV-LYH-CHO LINE...WILL MOST
LIKELY HOLDING OFF UNTIL LATE SATURDAY AFTERNOON B4 MIXING.
PASSAGE OF THE FRONT WILL OF COURSE BEGIN ANOTHER COOL DOWN
PROCESS...COLD AIR ADVECTION PUTTING A DRAG ON THE TEMPERATURE IN
THE MOUNTAINS LATE SATURDAY AFTERNOON...FOLLOWED BY AN AREAWIDE COOL
DOWN SATURDAY NIGHT...TEMPERATURES DIPPING BACK INTO THE 30S AS THE
RAIN TAPERS FROM WEST TO EAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 1230 PM EST WEDNESDAY...
12Z SUNDAY A SURFACE LOW IS WELL OFF THE COAST...MEANWHILE A SURFACE
HIGH IS OVER SOUTHERN QUEBEC. THIS WILL ONCE AGAIN WEDGE THE AREA
INTO A N/NE FLOW FOR SUNDAY AND MOST OF MONDAY. THE 12Z GFS IS MUCH
DRIER THAN PREVIOUS RUNS BUT STILL LEFT LOW CHANCE POPS IN. MONDAY A
LOW PRESSURE SYSTEM ACROSS WESTERN ONTARIO WILL DRIFT TOWARDS
SOUTHERN QUEBEC THROUGHOUT THE DAY. A TRAILING COLD FRONT WILL SWING
THROUGH OUR REGION MONDAY NIGHT AND INTO TUESDAY. THIS WILL INCREASE
THE CHANCE OF SHOWERS ACROSS THE MOUNTAINS AND SOME SNOW SHOWERS AT
THE HIGHER ELEVATIONS.
FLOW BECOMES NORTHWEST AFTER THE FRONTAL PASSAGE AND HIGH PRESSURE
STARTS TO BUILD IN FOR THE REMAINDER OF THE WEEK. LEFT LOW CHANCE
POPS IN ACROSS THE FAVORED UPSLOPE REGIONS...HOWEVER MOISTURE LOOKS
LIMITED AS OF THE LATEST GFS RUN.
TEMPS DURING THE PERIOD WILL RUN A FEW DEGREES BELOW NORMAL...MAINLY
LOOKING AT LOW TO MID 40S ACROSS THE MOUNTAINS AND NEAR 50 ACROSS
THE PIEDMONT.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AS OF 730 AM EST THURSDAY...
HIGH PRESSURE CONTINUES TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS THIS MORNING...SHIFTING WINDS INCREASINGLY
NORTHEASTERLY AS IT BUILDS ALONG THE BLUE RIDGE. STARTING THE
MORNING OFF VFR MOST LOCATIONS...WITH POCKETS OF FOG ACROSS THE
MOUNTAINS. FOG IS EXPECTED TO BURN OF WITH DAYTIME HEATING AFTER
14Z.
OUTSIDE OF FOG...EXPECT VFR CONDITIONS THROUGH THE AFTERNOON. RAIN
CHANCES WILL INCREASE SIGNIFICANTLY BEGINNING 18Z FOR MOST AIRPORTS
AS AN UPPER LEVEL DISTURBANCE PASSING ACROSS KENTUCKY AND TENNESSEE
PUSHES ACROSS THE MOUNTAINS LATER IN THE DAY. THIS RAIN WILL MOISTEN
THE ATMOSPHERE...BRINGING IT TO SATURATION DURING THE EVENING...
WHICH WILL CAUSE CEILINGS TO LOWER TO LOW MVFR/IFR LEVELS AFTER
SUNSET...WITH LITTLE TO NO IMPROVEMENT EXPECTED THROUGH THE NIGHT.
IN ADDITION TO LOW CEILINGS...PATCHY FOG AND DRIZZLE WILL DEVELOP...
ALSO HOLDING VISIBILITIES DOWN.
THE HIGH PRESSURE WEDGE WILL CONTINUE TO STRENGTHEN THROUGH THE
NIGHT...BRINGING INCREASINGLY COLDER AIR INTO THE AREA. AS SUCH...
POCKETS OF SLEET AND FREEZING RAIN ARE EXPECTED TO DEVELOP LATE
THURSDAY NIGHT INTO FRIDAY MORNING...MAINLY FOR THE RIDGES ALONG
THE INTERSTATE 64 CORRIDOR...AND SOUTHWARD ALONG THE SPINE OF THE
BLUE RIDGE. NO TAF SITES ARE EXPECTED TO EXPERIENCE ANYTHING BUT
LIQUID PRECIPITATION. TEMPERATURES WILL WARM ENOUGH BY LATE
FRIDAY MORNING TO END FREEZING PRECIPITATION.
EXTENDED DISCUSSION...
HIGH PRESSURE WEDGE WILL PERSIST FRIDAY AFTERNOON INTO SATURDAY...
WITH LINGERING MVFR CEILINGS MOST SPOTS AS WELL AS SPOTTY -RA OR
-DZ ESPECIALLY THE MOUNTAINS INTO SATURDAY MORNING. LOW PRESSURE
THAT IS FORECAST TO SLIDE UP ALONG THE WESTERN SIDE OF THE
APPALACHIANS MAY ACT TO HELP SCOUR OUT THE WEDGE BY SATURDAY NIGHT
AS THE ASSOCIATED COLD FRONT PUSHES ACROSS. HOWEVER RAIN AND LOW
CEILINGS PRECEDING THIS SYSTEM LIKELY TO MAKE FOR PERIODS OF IFR
ESPECIALLY SATURDAY AFTERNOON AND EVENING. DRIER AIR BEHIND THE
FRONT MAY BRING A BRIEF RETURN OF VFR ON SUNDAY BUT LOW CONFIDENCE
GIVEN THE SLOWNESS OF THIS SYSTEM TO MOVE OFFSHORE. OTHERWISE...YET
ANOTHER WEDGE INCLUDING SUB-VFR CEILINGS TO REDEVELOP SUNDAY
NIGHT INTO MONDAY IN THE WAKE OF THE DEPARTING FRONT.
&&
.EQUIPMENT...
AS OF 500 AM EST THURSDAY...
VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...IS WORKING IN A
DEGRADED MODE. PARTS WILL BE IN BY EARLY NEXT WEEK...THEN REPAIRS
CAN BE COMPLETED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF/WP
SHORT TERM...PM
LONG TERM...CF
AVIATION...AMS/JH/NF/WP
EQUIPMENT...AMS/WP
Area Forecast Discussion
National Weather Service Spokane WA
710 PM PST FRI DEC 5 2014
.SYNOPSIS...
A series of storm systems will bring a wintry mix of precipitation
to the Pacific Northwest through a good portion of the weekend.
Each day valley temperatures will warm a bit meaning a gradual
transition from freezing rain and snow to just plain rain. A
break in storm systems occurs Sunday but ends quickly with more
winter storms passing through as early as Sunday night and
continuing on through at least the early part of the next
workweek.
&&
.DISCUSSION...
Evening update: the forecast is generally on track, with newest
models continuing to bring the next batch of precipitation in from
the west tonight into Saturday. The chances tonight will be
largely near the Cascades, with the highest threat starting after
about 09Z (1 AM). Some light precipitation will also be possible
across the northern mountains of WA and ID tonight. Models then
blossom the precipitation across the remainder of eastern WA and
north ID between 4 AM and 1 PM Saturday, before things start to
wind down from the west Saturday night.
Some adjustments made to increase fog coverage from the previous
forecast, though it is expected to be largely patchy in fashion
and may still have opportunity to decrease from the southeast
overnight. Main area I added some patchy fog was toward the Blues
and L-C Valley, as well as out across the Basin into the the
Waterville Plateau. The fog is down to a half mile or so in spots,
such as near GEG and LWS, though it hasn`t been all that
consistently that low in LWS. I kept the fog going through the
night, but make it patchier in areas where it has been most dense
(i.e. western Spokane county and along the highway 2 corridor.
Later in the forecast, toward Saturday night into Sunday morning,
models suggest some low level moisture and southwest flow will
combine to bring a stratus and fog threat. It seems like a good
pattern for it. So the forecast was update to add this for a good
chunk of the basin/valley areas. Its coverage will be fine tuned
over the next day or so. /J. Cote`
&&
.AVIATION...
00Z TAFS: Widespread fog and low stratus will hang around much of
the region with MVFR/IFR conditions expected through tonight.
There is moderate confidence that flight conditions will improve
at the KLWS, KGEG, KSFF and KCOE TAF sites overnight due to
increased easterly flow that should bring in some drier air at
lower levels. These same locations could see sky conditions
scatter out, but confidence is low that this will occur due to how
moist the boundary layer is early this evening. A mid level cold
front will push across the region during the morning on Saturday.
This will result in an increasing chance for light rain at all TAF
sites with cigs degrading back into MVFR/IFR category. There is a
slight chance for freezing rain at KEAT through tonight into
Saturday morning, but there is some model discrepancy that
temperatures will be able to cool back to below freezing. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 37 32 37 31 38 / 10 90 20 0 10 30
Coeur d`Alene 31 35 33 36 31 38 / 10 90 40 0 10 30
Pullman 38 39 33 38 35 43 / 10 100 20 0 10 30
Lewiston 37 39 35 45 37 46 / 10 90 10 0 10 20
Colville 32 34 31 38 29 38 / 30 70 30 0 10 30
Sandpoint 29 34 32 37 29 36 / 10 90 50 10 0 30
Kellogg 34 35 33 38 30 37 / 10 100 50 0 0 30
Moses Lake 34 36 30 40 32 38 / 50 90 0 0 10 30
Wenatchee 31 35 30 39 32 39 / 80 80 0 0 20 30
Omak 30 34 28 33 29 36 / 60 80 0 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Air Stagnation Advisory until Noon PST Tuesday for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until Noon PST Saturday for East Slopes
Northern Cascades-Wenatchee Area.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
710 PM PST FRI DEC 5 2014
.SYNOPSIS...
A series of storm systems will bring a wintry mix of precipitation
to the Pacific Northwest through a good portion of the weekend.
Each day valley temperatures will warm a bit meaning a gradual
transition from freezing rain and snow to just plain rain. A
break in storm systems occurs Sunday but ends quickly with more
winter storms passing through as early as Sunday night and
continuing on through at least the early part of the next
workweek.
&&
.DISCUSSION...
Evening update: the forecast is generally on track, with newest
models continuing to bring the next batch of precipitation in from
the west tonight into Saturday. The chances tonight will be
largely near the Cascades, with the highest threat starting after
about 09Z (1 AM). Some light precipitation will also be possible
across the northern mountains of WA and ID tonight. Models then
blossom the precipitation across the remainder of eastern WA and
north ID between 4 AM and 1 PM Saturday, before things start to
wind down from the west Saturday night.
Some adjustments made to increase fog coverage from the previous
forecast, though it is expected to be largely patchy in fashion
and may still have opportunity to decrease from the southeast
overnight. Main area I added some patchy fog was toward the Blues
and L-C Valley, as well as out across the Basin into the the
Waterville Plateau. The fog is down to a half mile or so in spots,
such as near GEG and LWS, though it hasn`t been all that
consistently that low in LWS. I kept the fog going through the
night, but make it patchier in areas where it has been most dense
(i.e. western Spokane county and along the highway 2 corridor.
Later in the forecast, toward Saturday night into Sunday morning,
models suggest some low level moisture and southwest flow will
combine to bring a stratus and fog threat. It seems like a good
pattern for it. So the forecast was update to add this for a good
chunk of the basin/valley areas. Its coverage will be fine tuned
over the next day or so. /J. Cote`
&&
.AVIATION...
00Z TAFS: Widespread fog and low stratus will hang around much of
the region with MVFR/IFR conditions expected through tonight.
There is moderate confidence that flight conditions will improve
at the KLWS, KGEG, KSFF and KCOE TAF sites overnight due to
increased easterly flow that should bring in some drier air at
lower levels. These same locations could see sky conditions
scatter out, but confidence is low that this will occur due to how
moist the boundary layer is early this evening. A mid level cold
front will push across the region during the morning on Saturday.
This will result in an increasing chance for light rain at all TAF
sites with cigs degrading back into MVFR/IFR category. There is a
slight chance for freezing rain at KEAT through tonight into
Saturday morning, but there is some model discrepancy that
temperatures will be able to cool back to below freezing. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 37 32 37 31 38 / 10 90 20 0 10 30
Coeur d`Alene 31 35 33 36 31 38 / 10 90 40 0 10 30
Pullman 38 39 33 38 35 43 / 10 100 20 0 10 30
Lewiston 37 39 35 45 37 46 / 10 90 10 0 10 20
Colville 32 34 31 38 29 38 / 30 70 30 0 10 30
Sandpoint 29 34 32 37 29 36 / 10 90 50 10 0 30
Kellogg 34 35 33 38 30 37 / 10 100 50 0 0 30
Moses Lake 34 36 30 40 32 38 / 50 90 0 0 10 30
Wenatchee 31 35 30 39 32 39 / 80 80 0 0 20 30
Omak 30 34 28 33 29 36 / 60 80 0 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Air Stagnation Advisory until Noon PST Tuesday for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until Noon PST Saturday for East Slopes
Northern Cascades-Wenatchee Area.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
405 PM PST FRI DEC 5 2014
.SYNOPSIS...
A series of storm systems will bring a wintry mix of precipitation
to the Pacific Northwest through a good portion of the weekend.
Each day valley temperatures will warm a bit meaning a gradual
transition from freezing rain and snow to just plain rain. A
break in storm systems occurs Sunday but ends quickly with more
winter storms passing through as early as Sunday night and
continuing on through at least the early part of the next
workweek.
&&
.DISCUSSION...
Tonight: Conditions will dry out across the eastern and southern
third of the forecast area while the Cascades...Wenatchee
Area...and areas of the northern mountain deal with a messy wintry
mix.
Precipitation for much of today has been uneventful to say
the least with most midlevel circulations falling apart once they
cross into Chelan County. Regional radar indicates a line of
showers continuing to fill in from Kittitas County southward to
the central Oregon Cascades which are tracking north toward the
Hwy 97 corridor. It is uncertain whether these showers will
survive the trip into Chelan/Douglas Counties but HRRR continues
to hint at some showers during the 23-02z time-frame. Most
locations remain below freezing with a few exceptions. With
wetbulb effects and sunset approaching, it is unlikely any
location will remain above freezing. The showers moving through
the next few hours will not be a major player for freezing
rain.
Freezing rain advisories were extended to capture steady
light to moderate precipitation moving in after midnight and
continuing into Saturday morning. This is a much different setup
compared the last 48 hours which have proved much drier than
expected. This system will feature southeast flow in the lower
levels, moderate isentropic ascent, and rich moisture. So as far
as I am concerned, the precipitation will be certain...now the
temperatures will be a bigger wild card. Temperatures are
typically slow to warm with SE flow in the lower levels however
as the air mass moistens...it has no where to go but warmer. When
this transition occurs will be the challenge of the night.
Needless to say, travel is likely to be slick near the Cascades
and Wenatchee Area. Some light precip is possible in the Okanogan
Valley and Northern Mountains but amounts should be low and
concerns are lower.
One other travel concern looks to be localized along Hwy 2 between
Airway Heights and Davenport which is dense fog. There may be a
few other areas out there, but this looks to be the worse case via
a tour of CAMS and motorists should plan on visibilities near 1/4
mile at times. Temperatures remain near 32F for most locations
north of I-90 so there is also the potential for black ice
redeveloping tonight. Temperatures will not fall much from current
readings (maybe 1-2 degrees) and may even rise or remain steady
for much of the night so we are not expecting a hard freeze in any
locations. /sb
Saturday through Monday...High pressure will be over the Pacific
Northwest through Sunday before getting pushed off to the east
Sunday night. A couple of vigorous but fast moving short wave
disturbances will move through the ridge...the first on
Saturday...the second on Monday. These two waves will result in
more wet weather across the region through the short term.
Temperatures will be on the increase with warm air advection and
should be above normal through Monday.
*Precipitation: Yes more wet weather with chances of mixed
precipitation. The wave moving through the region on Saturday
will tap into fairly deep Pacific moisture and combine with
moderate to strong isentropic up-glide and orographic lift for
light to moderate precipitation. Precipitation will be on the
increase across the western zones around 12z and push across the
forecast area through the day. A cold front will follow quickly
behind. The front should eject into Montana late Saturday
afternoon. Low level southeast-south flow Saturday morning will
eliminate any Cascade shadowing for the lowers east slopes and
the deep basin. The flow will shift around to the southwest-west
by late Saturday afternoon as the front moves through the area.
Drying from the west should begin by late morning, with
precipitation lingering across the Panhandle through the evening
hours. Saturday night and Sunday the area will be in a dry
period, although fog and low clouds will be probable. The next
weak wave will run through the ridge on Monday. This wave does
not have the deep moisture tap nor the lifting mechanism of the
previous wave but will still result in some very light
precipitation Monday afternoon.
*Precipitation type: The valleys up against the Cascades have had
difficulty mixing out the cold air damned up against the
mountains. All indications are that precipitation may be as
freezing rain overnight, but should turn over to snow before
sunrise Saturday...especially for the Methow valley. Along the
the Columbia river and some of the northern valleys freezing rain
may also be a possibility for a few hours early Saturday morning,
but with increasing southerly flow these valleys should switch
over to rain. Precipitation amounts will range from around a
tenth or more for the lower elevations and a quarter to a third
of an inch for the mountains for the Saturday system. Snow
accumulation of 3-4 inches will be possible for the mountains
with possibly 1-2 inches for the Methow valley. For the Monday
system precipitation should be as valley rain and mountain snow,
with very light accumulations. Tobin
Monday night through Friday: Confidence is high that the region
will see a pattern shift through next week. Medium range models
are in good agreement that the longwave ridge of high pressure
will shift east into the Rookies and over the Northern Plains.
This will place the region in a more mild and wet weather pattern.
A pair of very moist low pressure systems will impact the region.
There is still some uncertainty with the timing of these two
systems. There is better agreement with the first system as models
show the region firmly under the warm sector Monday night into
Tuesday, and then the cold front sweeping through around Tuesday
afternoon or night. Models diverge considerably more with the
second weather system. The ECMWF is faster and shows a stronger
warm frontal passage Tuesday night into Wednesday morning. The GFS
is much slower with precip redeveloping Wednesday afternoon/evening.
Snow levels will be increasing with each of these weather systems.
A pocket of cold air looks to remain along the lee side of the
northern Cascades into the Okanogan Highlands through at least
Monday night. This will keep snow levels lower to between 2,000
and 3,000 feet. There is a chance for some wet snow in the upper
reaches of the Methow Valley, but confidence is low. All other
valley locations are expected to see rainfall. Moderate to heavy
rainfall amounts will be possible with P-wats +2 standard
deviations of normal and up to between 0.75-1.00 inches.
Temperatures will warm to above normal through mid week. The upper
level trough in the Gulf of Alaska looks to dig in across the
region late next week. This will result in an end to the warming
trend with temperatures dipping back closer to normal by Friday.
/SVH
&&
.AVIATION...
00Z TAFS: Widespread fog and low stratus will hang around much of
the region with MVFR/IFR conditions expected through tonight.
There is moderate confidence that flight conditions will improve
at the KLWS, KGEG, KSFF and KCOE TAF sites overnight due to
increased easterly flow that should bring in some drier air at
lower levels. These same locations could see sky conditions
scatter out, but confidence is low that this will occur due to how
moist the boundary layer is early this evening. A mid level cold
front will push across the region during the morning on Saturday.
This will result in an increasing chance for light rain at all TAF
sites with cigs degrading back into MVFR/IFR category. There is a
slight chance for freezing rain at KEAT through tonight into
Saturday morning, but there is some model discrepancy that
temperatures will be able to cool back to below freezing. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 37 32 37 31 39 / 10 90 20 0 10 30
Coeur d`Alene 31 35 33 36 31 39 / 10 90 40 0 10 30
Pullman 38 39 33 38 35 44 / 10 100 20 0 10 30
Lewiston 37 39 35 45 37 47 / 10 90 10 0 10 20
Colville 32 34 31 38 29 39 / 30 70 30 0 10 30
Sandpoint 29 34 32 37 29 36 / 10 90 50 10 0 30
Kellogg 34 35 33 38 30 38 / 10 100 50 0 0 30
Moses Lake 34 36 30 40 32 39 / 50 90 0 0 10 30
Wenatchee 31 35 30 39 32 39 / 80 80 0 0 20 30
Omak 30 34 28 33 29 36 / 60 80 0 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Air Stagnation Advisory until Noon PST Tuesday for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until Noon PST Saturday for East Slopes
Northern Cascades-Wenatchee Area.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
306 AM PST FRI DEC 5 2014
.SYNOPSIS...
A series of storm systems will bring a wintry mix of precipitation
to the Pacific Northwest through a good portion of the weekend.
Each day valley temperatures will warm a bit meaning a gradual
transition from freezing rain and snow to just plain rain. A
break in storm systems occurs Sunday but ends quickly with more
winter storms passing through as early as Sunday night and
continuing on through at least the early part of the next
workweek.
&&
.DISCUSSION...
Today and tonight ... The widespread precipitation from earlier tonight
is beginning to taper off as the shortwave disturbance which
enhanced the ascent and moisture continues to push toward Montana.
The latest radar imagery was only detecting a smattering of light
precipitation generally east of a line from Kettle Falls to the
Camas Prairie. The trend for this precipitation will be a
diminishing one as drier air begins to infiltrate the key
dendritic layer. Whether or not this truly eliminates the
precipitation is questionable as the layer beneath will continue
to see fair isentropic ascent combined with a fairly moist lowest
level of the atmosphere. This could either equate to very light
snow or freezing drizzle. For the Spokane and Coeur d`Alene area
we could see a little of both. Precipitation alone will not
necessitate the extension of the freezing rain advisory however
with temperatures hovering right at or slightly below freezing
road conditions will likely remain poor until later today. North
and east of the Spokane area we suspect most of the precipitation
will remain as light snow at least until sunrise. After that it
could also become a combination of very light snow or freezing
drizzle as the dendritic layer dries here as well.
Elsewhere the current weather regime is fairly quiet...however that
will likely change as a warm front moves in from the southwest.
Regional radar mosaics show precipitation from this front
blossoming along a line from the Dalles toward Olympia moving
northeastward. How far east the precipitation from this feature
spreads is the big question for today. Model guidance is in decent
agreement that most of it will remain confined to the west of
Moses Lake toward the Cascades. The HRRR model says not much will
result from the approach of the front this morning...however it`s
under-doing the amount of precipitation falling right now near the
Columbia Gorge. Most of the remaining model guidance suggests
precipitation will likely fall in these areas but amounts should
be well under a tenth of an inch. Based on temperature profiles in
that area...the main precipitation regime will likely be freezing
rain with snow generally north of Lake Chelan. Given this
scenario...we will continue with the various freezing rain
advisories for now as confidence is high as ground temperatures
will remain below freezing with a melting layer between 2-4k feet
above ground.
For later today and into the evening...the front continues to move
to the north while the mean mid-level flow turns increasingly
southerly. This will allow the surface warm sector to surge
northward bringing a brief drying trend beginning over SE
Washington/NC Idaho and moving northward. During this time most
of the precipitation will remain confined near the Cascades as
well as the far northern portions of the forecast area. Most of
the precipitation will transition from snow to rain in the
northern valleys...however sub-freezing air will remain fixed near
the Cascades...so freezing rain or snow will remain the most
common precipitation type. The precipitation threat will likely
increase once again late tonight...at least near the Cascades.
This time the precipitation will result from the approach of a
shortwave trough currently near 132w. By this time it arrives the
only locations left with an elevated melting layer and sub-
freezing air near the ground will be near the Cascades. This is
actually the strongest of the systems expected during the next 24
hours. Precipitation chances will be nearly 100 percent near the
Cascades as the mid-layer flow backs to more of a southeast regime
resulting in good upslope flow potential. While pockets of
freezing rain will still be possible...it will be far from as
widespread as the threat this morning will be. No highlights are
anticipated for tonight`s event. Valleys which see snow could pick
up 1-2 inches...especially north of Lake Chelan...with mountain
snows of several inches possible. Precipitation will really begin
to pick up by Saturday morning. fx
Saturday through Sunday Night: An upper level trough will move
through the area in southwest flow Saturday. Models have been
pretty consistent and so confidence is high of widespread rain.
Cold air will still remain across the Methow valley and nearby
valleys. Expect a mixed bag of snow and freezing rain through at
least the morning hours. By afternoon the winds become more
westerly and our typical shadowing of the east slopes valleys and
into the Moses Lake area will occur. Precip will decrease from
west to east through the day. By Sat evening most of the rain and
mountain snow will be confined to north ID. Sunday is the only dry
period in the entire 7 day forecast...so enjoy it while you can.
Models have been slowing down the next oncoming weather system,
and so have decreased chance of precipitation quite a bit for
Sunday night. The best chance of precip will be along the
Cascades.
Monday through Wednesday: Large amounts of moisture will stream
in from the Pacific to create quite a wet period. Broad southwest
flow will usher in wave after wave. The first widespread precip
event starts Monday night into Tuesday. The southwest flow will
provide warmer air and temperatures should remain above freezing
south of Highway 2 for a rain event. The northern valleys across
northeast WA and north ID will see rain...however the valleys
across north central WA will see a rain/snow mix or rain during
the day with snow at night. The mountains will see mostly snow.
Snow levels will vary...but generally 3500-4000 feet is expected
across northern WA and ID. Still concerned about the potential of
feet of snow in the Cascades Monday night through Tuesday night.
The GFS is going gangbusters with qpf, where as the EC is being
more conservative. Either model you go with...we are still talking
at least 2 feet of snow possible along the crest. Confidence is
also growing for heavy snow potential in the Northeast Mountains
of WA and the North ID Panhandle Mountains for Tuesday. Main
changes made to this portion of the forecast was to decrease
chances of precip Monday. Models seem to be slowing down the
timing of the onslot of moisture.
Thursday and Friday: The models really start to diverge by late
in the work week. The EC and GFS both have a longwave trough over
the western US, but they vary greatly on locations of where low
pressure systems will set up. Either way the result is still south
to southwest flow with periods of rain and snow in the forecast.
Temperatures: Temperatures Saturday through next Friday will be
above average. Models have backed off a bit on how warm we could
get Sat through Mon, so have started the trend down a bit, but
will still see above average temps. Highs in the mid 30s to mid
40s with lows in the mid 20s to mid 30s are expected across the
Inland Northwest. /Nisbet
&&
.AVIATION...
06Z TAFS: Wintry mix continues across eastern WA and north ID. GEG
to COE are expected to see -fzra through the early overnight, with
chances waning between 09-12Z. That may change to rain near SFF
during the time. Look for IFR cigs and vis, with potentialy dense
fog near GEG for the early morning 14-19Z or so. Conditions will
remain IFR and low MVFR in that region after 19Z. Toward PUW/LWS
mainly rain is expected tonight, with a similar decrease in the
precipitation threat going into Friday morning. IFR/MVFR conditions
expected here, with possible VFR conditions around LWS in the
afternoon. Farther west toward MWH and especially EAT the threat
of freezing rain will develop overnight into Friday morning, with
the front slipping into region. So look for some icing threat
around especially around 11-18Z in EAT, with a smaller risk in MWH.
/J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 35 33 39 32 39 31 / 40 10 90 10 0 0
Coeur d`Alene 35 33 38 33 40 31 / 40 10 90 20 0 0
Pullman 40 35 41 33 42 35 / 20 10 90 10 0 0
Lewiston 42 37 44 35 45 37 / 20 10 80 0 0 0
Colville 35 31 38 31 39 30 / 80 30 70 20 0 10
Sandpoint 34 32 38 32 39 30 / 70 20 90 40 10 0
Kellogg 36 32 37 33 40 31 / 50 10 100 40 0 0
Moses Lake 35 31 40 30 40 31 / 50 40 80 0 0 10
Wenatchee 34 31 39 30 37 32 / 60 60 70 0 0 10
Omak 32 30 36 27 35 29 / 90 60 70 0 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Freezing Rain Advisory until 4 AM PST early this morning for
Coeur d`Alene Area-Idaho Palouse.
WA...Air Stagnation Advisory until 4 AM PST Saturday for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until 10 AM PST this morning for East
Slopes Northern Cascades-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until 4 AM PST early this morning for
Spokane Area-Washington Palouse.
Freezing Rain Advisory until 7 AM PST this morning for Moses
Lake Area-Upper Columbia Basin.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
307 PM CST THU DEC 4 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 307 PM CST THU DEC 4 2014
AT 2 PM...A 1031 MB SURFACE HIGH WAS CENTERED OVER SAGINAW BAY
/PART OF LAKE HURON/. SOUTHERLY WINDS ON THE BACK SIDE OF THIS
HIGH HAVE CAUSED TEMPERATURES SOUTH OF INTERSTATE 94 TO CLIMB INTO
THE LOWER AND MID 30S. MEANWHILE NORTH OF THIS INTERSTATE...THE
TEMPERATURES ARE STILL IN THE 20S.
FOR TONIGHT AND FRIDAY MORNING...THE 04.12Z MODELS ARE IN GOOD
AGREEMENT THAT WEAK 925 TO 850 MB MOISTURE TRANSPORT WILL DEVELOP
ACROSS THE AREA. THIS IS IN ADVANCE OF A SHORT WAVE TROUGH WHICH
WILL BE MOVING EAST ACROSS NORTHERN MINNESOTA AND NORTHERN
WISCONSIN. THE NAM AND RAP SOUNDINGS SHOW THAT THE AIR MASS BELOW
800 MB WILL BECOME SATURATED AND THERE WILL BE SOME WEAK OMEGA IN
THIS LAYER. THIS WOULD RESULT IN PATCHY FREEZING DRIZZLE.
MEANWHILE THE GFS...SATURATES THE LAYER BETWEEN 950 AND 800 MB AND
KEEPS A DRY LAYER NEAR THE SURFACE. THIS WOULD RESULT IN JUST A
LIFR/IFR DECK OF CLOUDS. UNTIL THIS PAST HOUR WAS LEANING MORE TOWARD
THE GFS BECAUSE THERE WAS NO DRIZZLE OR LOW CLOUDS ACROSS NORTHERN
MISSOURI AND CENTRAL ILLINOIS. HOWEVER BOTH OF THESE ARE STARTING
TO SHOW UP IN THE OBSERVATIONS ACROSS THIS AREA...SO MAYBE THE NAM
AND RUC ARE HANDLING THIS BETTER THAN ORIGINALLY THOUGHT. DUE TO
THIS...KEPT A 15 PERCENT PRECIPITATION CHANCE FOR FREEZING
DRIZZLE IN THE FORECAST. LIKE THE PREVIOUS SHIFT...USED THE 925 TO
850 MB RELATIVE HUMIDITY TO TIME THE FREEZING DRIZZLE ONSET AND
ENDING.
ON FRIDAY AFTERNOON AND EVENING...A SHORT WAVE TROUGH IN THE
SOUTHERN STREAM WILL MOVE NORTHEAST THROUGH THE MID MISSISSIPPI
RIVER VALLEY INTO THE SOUTHERN GREAT LAKES. LIKE PREVIOUS
RUNS...IT LOOKS LIKE THE SYNOPTIC LIFT AND MOISTURE WILL REMAIN
SOUTHEAST OF THE FORECAST AREA. AS A RESULT...KEPT THE FORECAST
DRY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 307 PM CST THU DEC 4 2014
FROM SUNDAY THROUGH MONDAY...THE MODELS CONTINUE TO SHOW THAT A
SHORT WAVE TROUGH WILL MOVE EAST THROUGH THE REGION. THIS WAVE
REMAINS AN OPEN WAVE SO THE MODELS ARE MORE PROGRESSIVE THAN THEY
WERE EARLIER. DUE TO THIS...IT LOOKS LIKE THE PRECIPITATION WILL
LIKELY ONLY OCCUR FOR AN 12 TO 18 HOUR PERIOD. SOME OF THE MODELS
SUGGEST THAT DRY AIR WILL MOVE IN ALOFT ON SUNDAY NIGHT. IF
THIS IS CORRECT...THERE WOULD BE A LOSS OF ICE FROM ALOFT...AND
THE PRECIPITATION TYPE WOULD CHANGE FROM SNOW TO EITHER A RAIN OR
FREEZING RAIN. SOME OF THE MODELS SUGGEST THAT THE TEMPERATURES
WILL REMAIN ABOVE FREEZING ACROSS MUCH OF THE AREA...SO MAY NOT
HAVE TOO MUCH OF A FREEZING RAIN THREAT. SINCE THIS IS STILL OVER
84 HOUR OUT...IT WAS THE CONSENSUS TO JUST KEEP THE FORECAST IN
THE FORM OF RAIN AND SNOW FOR NOW. WITH THE MIXED PRECIPITATION
AMOUNTS...DOES NOT LOOK LIKE THERE WILL BE TOO MUCH SNOW. GFS COBB
DATA CURRENTLY IS SHOWING A HALF INCH OR LESS OF SNOW.
ON WEDNESDAY...THE GFS SHOW THAT A SHORT WAVE TROUGH WILL PRODUCE
RAIN OR FREEZING RAIN AS IT MOVES THROUGH THE NORTHERN MINNESOTA
AND WISCONSIN. SOUNDINGS NORTH OF INTERSTATE 94 KEEP MUCH OF THEIR
SATURATION BELOW 900 MB AND BETWEEN 600 AND 700 MB...SO THINKING
THAT THE MODELS MAY BE OVER DOING THIS PRECIPITATION...SO OPTED TO
FOLLOW THE ECMWF AND KEEP THE FORECAST DRY FOR NOW.
ON THURSDAY...THE MODELS CONTINUE TO STRUGGLE ON HOW FAST WE WILL
WARM UP. THE GFS WARMS THE 850 MB TEMPERATURES INTO THE 10 TO 14C
RANGE. MEANWHILE THE ECMWF HAS THESE TEMPERATURES RANGING FROM 0
TO -4C. THE CFS VERSION 2 OVER THE PAST 5 DAYS ARE SUGGESTING
THAT THE HIGHS ON THIS DAY WILL RANGE FROM 35 TO 40 NORTH OF
INTERSTATE 94 AND FROM 40 TO 45 WITH A STANDARD DEVIATION LESS
THAN 1. MEANWHILE THE DETERMINISTIC ECMWF MOS HAS HIGHS AROUND
30...BUT THIS IS MUCH LOWER THAN ITS ENSEMBLE MEAN. WITH SUCH
DIFFERENCES STAYED NEAR THE MODEL BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1131 AM CST THU DEC 4 2014
INITIAL CONCERN IS CLOUD TRENDS. MID-LEVEL CEILING IS TRAVERSING
EAST...BUT NEXT ROUND OF WARM ADVECTION SENDING A NEW CLOUD SHIELD
AT US FROM THE SOUTH. EXPECT THAT TO ARRIVE AT THE AIRFIELDS
SHORTLY AFTER SUNSET. CEILINGS GRADUALY LOWER AS LOW LEVEL
MOISTURE INCREASES AHEAD OF THE SHORT WAVE TROUGH MOVING THROUGH
THE CENTRAL PART OF THE COUNTRY. BULK OF THE PRECIPITATION WILL
STAY WELL SOUTH...BUT MODEL SOUNDINGS DO SUPPORT THE POSSIBILITY
OF A SATURATED BOUNDARY LAYER UP TO ABOUT 4KFT. THIS WILL LEAD TO
STRATUS AND PERHAPS SOME LIGHT FOG. DRIZZLE IS ALSO A DISTINCT
POSSIBILITY AND WITH THE SOUNDING ALL BELOW FREEZING BUT NO SOURCE
OF ICE...IF IT OCCURS WILL BE AS FREEZING DRIZZLE. THIS CHANCE
STILL APPEARS SMALL HOWEVER...TOO SMALL TO INCLUDE IN TAFS AT THIS
TIME. AS WARM ADVECTION CONTINUES INTO FRIDAY...THE LOW LEVEL
MOISTURE IS TRAPPED BELOW THE STRENGTHENING INVERSION...SO
ANTICIPATE THAT IFR/LIFR CEILINGS WILL PERSIST FOR MUCH OF THE
DAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...MW
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
953 PM MST WED DEC 3 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 246 PM MST WED DEC 3 2014
WEAK SHORTWAVE EMBEDDED WITHIN WESTERLY FLOW WILL DEPART THE
REGION TONIGHT. BUT NOT BEFORE PRODUCING MOUNTAIN SNOW OVER THE
SNOWY AND SIERRA MADRE RANGES AS WELL AS A LIGHT RAIN/SNOW MIX
OVER THE ADJACENT LOWER ELEVATIONS. NOT EXPECTING ALL THAT
SIGNIFICANT OF AN EVENT...BUT A FEW INCHES OF ACCUMULATION CAN BE
EXPECTED OVR THE ABOVE 7500 FEET THRU THE EVENING. HAVE ALSO ADDED
SLIGHT CHANCES FOR A RAIN/SNOW SHOWER NORTH OF HWY 26 LATE THIS
AFTERNOON...AS THE SHORTWAVE INTERACTS WITH FAIRLY STEEP H7-H5
LAPSE RATES. AGAIN...ANYTHING WOULD BE LIGHT AND ANY CHANCE SHOULD
WANE QUICKLY WITH LOSS OF INSOLATION DRIVEN INSTABILITY.
A VERY MILD DAY AHEAD FOR THURSDAY AS FLOW BACKS SLIGHTLY TO
WEST/SOUTHWEST. H7 TEMPS WARM FROM AROUND -2C TODAY TO
FREEZING...WHICH WHEN COMBINED WITH DOWNSLOPE WESTERLY WINDS WILL
BOOST HIGHS ON THE ERN PLAINS IN TO THE UPPER 50S AND EVEN SOME LOW
60S. ASIDE FROM SOME LIGHT SNOW OR FLURRY CHANCES OVR THE SNOWY AND
SIERRA MADRE RANGES...THURSDAY WILL BE DRY. OTHER THAN THE
OCCASIONAL WIND GUST OF 20-30 MPH OVR SOUTHEAST WYOMING...ANTICIPATE
NO OTHER WIND CONCERNS.
FRIDAY WILL BE A BIT COOLER AS A WEAK/DRY COLD FROPA DROPS SOUTH
THRU THE CWFA. EVEN SO...HIGH TEMPERATURES WILL CONTINUE TO BE WELL
ABOVE SEASONAL NORMS AS HIGHS REACH THE 40S WEST OF THE LARAMIE
RANGE AND LOW 50S OUT ON THE ERN PLAINS. AN UPSTREAM AMPLIFYING
UPPER RIDGE WILL PUSH INTO THE AREA FRIDAY NIGHT KEEPING WINDS AND
PRECIP CHANCES AT BAY.
.LONG TERM...(SATURDAY THROUGH TUESDAY NIGHT)
ISSUED AT 246 PM MST WED DEC 3 2014
THE SPLIT FLOW PATTERN WILL REMAIN IN PLACE FOR SATURDAY AND
SUNDAY...WITH ONE SHORTWAVE TROUGH MOVING EAST ACROSS THE DESERT
SOUTHWEST AND ANOTHER MOVING EAST-SOUTHEAST ACROSS THE NORTHERN
ROCKIES AND HIGH PLAINS. THE NORTHERN STREAM WAVE LOOKS TO DEEPEN
THE LEESIDE SFC PRESSURE TROUGH ON SATURDAY AND SATURDAY
NIGHT...WITH SFC WINDS ACROSS SOUTHEAST WYOMING INCREASING THROUGH
THE DAY AND BECOMING STRONG EARLY SUNDAY MORNING. GFS PAINTS WIND
SPEEDS OF 45 TO 50 KTS IN THE 800 TO 700 MB LAYER ACROSS THE
FORECAST AREA BY 12Z SUNDAY...WHICH COULD TRANSLATE TO A MARGINAL
GAP WIND EVENT MAINLY FOR THE WIND PRONE AREAS AS THE GFS ALSO
SHOWS THE INVERSION SETTING UP AT MOUNTAIN TOP LEVEL. WINDS WILL
BE ON THE BREEZY SIDE ELSEWHERE THRU SUNDAY AS THE LEESIDE TROUGH
SHIFTS EAST IN ASSOCIATION WITH THE UPPER WAVE. THE DEEPEST
MOISTURE WILL REMAIN BOTH NORTH AND SOUTH OF THE AREA MORE
COLLOCATED WITH THE WAVE...SO OUTSIDE OF PERHAPS SOME MOUNTAIN
SNOW SHOWERS...CONDITIONS SHOULD REMAIN DRY THROUGH SUNDAY. MODELS
THEN SHOW A GENERAL TREND TOWARD DRY NORTHWEST FLOW SUNDAY NIGHT
INTO MONDAY...WITH RIDGING BUILDING IN FROM THE WEST. THE NEXT
CHANCE FOR PRECIP IS ON TUESDAY AS ANOTHER...ALBEIT
WEAKER...SHORTWAVE TROUGH IS PROGGED TO MOVE ACROSS THE ROCKIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 950 PM MST WED DEC 3 2014
ONLY CONCERNS WEATHERWISE FOR SOUTHEAST WYOMING AIR TERMINALS WILL
BE KRWL TONIGHT AS LATEST HRRR SHOWS MVFR/IFR CONDITIONS CLOSE TO
THE AIRPORT. DO NOT THINK LOW CLOUDS WILL BE WIDESPREAD ENOUGH TO
BRING KRWL DOWN TO IFR...SO WENT MVFR FOR A TIME OVERNIGHT. VFR
CONDITIONS ELSEWHERE ACROSS SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE.
&&
.FIRE WEATHER...
ISSUED AT 246 PM MST WED DEC 3 2014
A QUIET PERIOD TAKING SHAPE THROUGH THE UPCOMING WEEKEND. THE
SNOWY AND SIERRA MADRE RANGES MAY SEE A FEW INCHES OF SNOW THROUGH
THE EVENING...ESPECIALLY UP AT THE HIGHER PEAKS. THE AREA WILL SEE
A REPRIEVE FROM THE STRONGEST WINDS AS WELL THROUGH THE WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CAH
LONG TERM...RJM
AVIATION...GCC
FIRE WEATHER...CAH
AREA FORECAST DISCUSSION
NWS TUCSON AZ
212 AM MST SAT DEC 6 2014
.SYNOPSIS...ANOTHER WEATHER SYSTEM FROM THE EASTERN PACIFIC WILL
BRING A FEW SHOWERS TO THE AREA TODAY. OTHERWISE...EXPECT NEAR TO
ABOVE AVERAGE TEMPERATURES INTO NEXT WEEK WITH DRY CONDITIONS.
&&
.DISCUSSION...A WEATHER SYSTEM FROM THE EASTERN PACIFIC WILL TRACK
THROUGH THE WESTERN STATES TODAY. THE TAIL END OF THIS SYSTEM WAS
PROGGED TO PASS THROUGH SOUTHERN ARIZONA WITH LIMITED MOISTURE THIS
FAR SOUTH. THE NAM AND HRRR MODELS WERE REALLY THE ONLY SOLUTIONS
THAT SUGGESTED MEASURABLE PRECIPITATION WITH THE LATEST SREF SHOWING
THE BEST CHANCES ACROSS THE RIM COUNTRY AND MOUNTAINS. THUS...HAVE
DECIDED TO DECREASE PRECIPITATION CHANCES ACROSS MOST OF SOUTHEAST
ARIZONA FOR TODAY. OTHERWISE...MODELS SHOWED A SHORTWAVE RIDGE
BUILDING OVER THE DESERT SOUTHWEST SUNDAY AND MONDAY...THEN
FLATTENING A BIT TUESDAY AS A WEAK SYSTEM PASSES THROUGH THE CENTRAL
ROCKIES. MORE RIDGING WEDNESDAY INTO THURSDAY AHEAD OF ANOTHER
SYSTEM ENTERING THE WEST COAST. MEDIUM RANGE MODELS SHOWED THIS NEXT
SYSTEM BRINGING A GOOD CHANCE OF PRECIPITATION TO THE AREA BY FRIDAY
EVENING INTO SATURDAY. DAYTIME TEMPERATURES WILL REMAIN NEAR OR A
FEW DEGREES ABOVE NORMAL READINGS THROUGH NEXT WEEK.
&&
.AVIATION...VALID THRU 07/12Z.
BKN-OVC HIGH CLOUDS...MAINLY ABOVE 16K FT AGL...WITH FEW-SCT CLOUDS
AT 6-10K FT AGL DEVELOPING BY 06/18Z. SLIGHT CHANCE OF -SHRA MAINLY
OVER THE HIGHER TERRAIN AND MAINLY AFT 06/18Z. LOCAL AREAS OF BR
EARLY THIS MORNING...DIMINISHING BY 06/16Z. WINDS WILL REMAIN
LIGHT...GENERALLY LESS THAN 10 KTS THROUGH THE FORECAST PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A WEAK SYSTEM WILL MOVE NORTH OF THE REGION TODAY.
THIS SYSTEM WILL RESULT IN A SLIGHT CHANCE OF SHOWERS...MAINLY OVER
THE HIGHER TERRAIN TODAY AND TONIGHT. WINDS ARE EXPECTED TO BE LIGHT
INTO THE MIDDLE OF NEXT WEEK...GENERALLY LESS THAN 15 MPH. HIGH
TEMPERATURES WILL BE 2 TO 5 DEGREES ABOVE SEASONAL AVERAGES THROUGH
THE WEEKEND AND 4 TO 8 DEGREES ABOVE NORMAL NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
1155 PM PST FRI DEC 5 2014
.SYNOPSIS...
ANOTHER WEAK SYSTEM WILL BRING SOME LIGHT SHOWERS INTO THE AREA
MAINLY NORTH OF KERN COUNTY TONIGHT. DRY CONDITIONS ARE EXPECTED BY
SATURDAY NIGHT WITH NIGHTTIME AND MORNING VALLEY FOG AS HIGH
PRESSURE BRIEFLY RETURNS. ANOTHER WEAK SYSTEM IS EXPECTED TO SKIRT
ACROSS THE NORTHERN PORTION OF THE STATE ON MONDAY...WITH LIGHT RAIN
POSSIBLE NORTH OF FRESNO COUNTY.
&&
.DISCUSSION...
QUICK UPDATE TO THE FORECAST TO INCLUDE FOG FOR THE NORTHERN
ANTELOPE VALLEY/SOUTHEAST KERN COUNTY AND LOWER POPS CWA-WIDE.
POPS...FORCING IS FALLING APART WITH THE SYSTEM TRAVERSES OUR CWA.
HRRR AND OTHER HI-RES MODELS AGREE THAT SHOWERS WILL CONTINUE TO
DRASTICALLY DECREASE NEXT FEW HOURS THEREFORE HAVE REDUCED POPS
MOST AREAS.
NEXT UP IS FOG POTENTIAL FOR PARTS OF THE MOJAVE DESERT.
VISIBILITY SENSORS THERE ARE ALREADY TRENDING DOWN INTO THE 5-6SM
RANGE. BASED ON UPS METHOD/CROSSOVER TEMPERATURES FOG IS LIKELY TO
FORM. FOR EXAMPLE...THE XOVER TEMP AT KMHV IS 45F AND CURRENT TEMP
IS ALREADY DOWN TO 50 /WITH 100 PERCENT HUMIDITY/. THE FORECAST
LOW IS IN THE LOWER 40S. ADDITIONAL SUPPORT INCLUDES THE VEGAS
SOUNDING SHOWING A SATURATED BOUNDARY LAYER/INCREASING HUMIDITY
WITH HEIGHT. FINALLY...SEVERAL RUNS OF THE HRRR HAVE GENERATED FOG
IN THAT AREA OVER THE NEXT FEW HOURS. THEREFORE ADDED FOG TO
FORECAST. WILL MONITOR OVERNIGHT FOR POTENTIAL OF A DENSE FOG
ADVISORY BUT WILL COVER THE MESSAGE VIA OUR SOCIAL MEDIA CHANNELS
FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 348 PM PST FRI DEC 5 2014/
DISCUSSION...IT HAS BEEN A RELATIVELY MILD DAY ACROSS CENTRAL
CALIFORNIA TODAY UNDER CLOUDY SKIES AHEAD OF THE NEXT APPROACHING
WEAK FRONTAL SYSTEM. RADAR SHOWS ASSOCIATED SHOWERS IMPACTING
COASTAL AREAS TO OUR WEST. HIGH RESOLUTION MODELS PROG THESE
SCATTERED SHOWERS TO PUSH EAST THROUGH OUR AREA THIS EVENING
LINGERING INTO EARLY SATURDAY MORNING...THOUGH THE BEST PRECIP
STAYS TO OUR NORTH WITH THE MAIN ENERGY. VALLEY QPF RANGES FROM
AROUND 1/10 OF AN INCH NORTH TO JUST A HUNDREDTH OR SO TOWARD
KERN COUNTY. HIGHER ELEVATION AMOUNTS SIMILARLY TAPER FROM AROUND
A QUARTER INCH NEAR YOSEMITE TO NOTHING IN KERN COUNTY.
BRIEF SHORTWAVE RIDGING BEHIND THE SYSTEM YIELDS DRY AND CONTINUED
MILD CONDITIONS SATURDAY AND SUNDAY. ANOTHER WEAK RIPPLE TRACKS BY
TO THE NORTH BY MONDAY...BRINGING JUST A SLIGHT CHANCE FOR PRECIP
NORTH OF FRESNO COUNTY. OTHERWISE...DRY AND MILD CONTINUES INTO
MIDWEEK.
A MORE SIGNIFICANT SYSTEM...REMNANTS OF A SUPER TYPHOON...IS
PROGGED TO SLAM INTO THE WEST COAST BY THURSDAY. MODELS OF COURSE
HAVE DIFFERENCES IN TIMING AND STRENGTH OF THIS SYSTEM...BUT
ENSEMBLES SUGGEST THERE IS A GOOD CHANCE THAT OUR AREA WILL BE
AFFECTED WITH RAIN AND MOUNTAIN SNOW AS WELL AS TYPICAL GUSTY
WINDS OVER MOUNTAIN RIDGES AND THROUGH AND BELOW PASSES. THIS WILL
BE A SOMEWHAT WARM STORM WITH RELATIVELY HIGH SNOW LEVELS. AS THE
EVENT APPROACHES WE WILL BE ABLE TO REFINE TIMING AND AMOUNTS.
&&
.AVIATION...
SCATTERED LIGHT RAIN SHOWERS THIS EVENING THRU 12Z SAT...MVFR
CEILINGS WITH LOCAL IFR POSSIBLE AT TIMES...MAINLY NORTH OF KERN
COUNTY. OTHERWISE EXPECT VFR CONDITIONS TO PREVAIL OVER THE CENTRAL
CALIFORNIA INTERIOR OVER THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 12-05 72:1958 40:1963 52:2012 28:1903
KFAT 12-06 68:1995 42:1965 55:2012 28:1891
KFAT 12-07 69:1937 42:1965 52:1950 25:1978
KBFL 12-05 80:1918 43:1965 55:1966 23:1903
KBFL 12-06 77:1916 42:1965 60:1918 22:1903
KBFL 12-07 76:1907 41:1965 53:1950 24:1912
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...INIGUEZ
AVN/FW...BSO
PREV DISCUSSION...JEB
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS MIAMI FL
313 AM EST SAT DEC 6 2014
.SYNOPSIS...
GENERALLY DRY CONDITIONS WILL PREVAIL INTO NEXT WEEK...WITH
SLIGHTLY COOLER TEMPERATURES ARRIVING BY TUESDAY.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE THAT HAS BEEN WEDGED ON THE LEE SIDE OF THE
APPALACHIANS AND DOMINATING SOUTH FLORIDA WEATHER THIS WEEK WILL
FINALLY SPREAD OFFSHORE. THIS WILL RESULT IN LIGHTER WINDS FROM A
MORE NORTHERLY DIRECTION TODAY. LESS MOIST LOW-LEVELS SHOULD
PRECLUDE THE ISOLATED/SCATTERED SHOWER ACTIVITY THAT HAS PESTERED
THE ATLANTIC COAST MUCH OF THIS WEEK. A SHORTWAVE TROUGH WILL
CROSS THE NORTHEAST CONUS THIS WEEKEND...WITH THE ATTENDANT COLD
FRONT ENTERING NORTHERN FLORIDA LATE TONIGHT. THIS FRONT WILL
DISSIPATE AS IT PASSES CENTRAL FLORIDA...BUT HIGH PRESSURE WILL
STILL BUILD SOUTHWARD INTO SOUTH FLORIDA SUNDAY INTO MONDAY. THE
DRYING TREND WILL CONTINUE THIS WEEKEND...AND ABOVE NORMAL
TEMPERATURES TODAY WILL GRADUALLY DIP TO NEAR NORMAL BY
MONDAY...AS MODIFIED CANADIAN AIRMASS FILTERS IN.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A DEEPER SHORTWAVE TROUGH /PARTICULARLY IF THE ECMWF VERIFIES/
WILL CROSS NERN STATES LATE MONDAY INTO TUESDAY. ANOTHER...LIKELY
DRY FRONT...WILL ENTER NORTH FLORIDA AND THIS TIME CROSS THE
PENINSULA. THE MODEL DISCREPANCIES OF THE PAST SEVERAL DAYS HAVE
DIMINISHED...AND APPEAR TO BE CONVERGING ON NOTICEABLY COOLER AND
DRIER AIRMASS BEHIND THE FRONT FOR TUESDAY THROUGH THURSDAY.
TEMPERATURES WILL LIKELY BE SLIGHTLY BELOW NORMAL...WITH MAXIMA
MAINLY IN THE LOW 70S...MINIMA RANGING FROM UPPER 40S NW TO AROUND
60F ATLANTIC COAST. FLOW WILL REMAIN N OR NW UNTIL THURSDAY...THEN
MODERATING TEMPERATURES AND INCREASING MOISTURE COMMENCE AS WINDS
TURN NE. SHOWER CHANCES WILL REMAIN SLIGHT AT BEST THROUGH THE
PERIOD.
&&
.AVIATION...
LIGHT SHOWERS CONTINUE TO EXIT THE EAST COAST SITES...PUSHING OFF
TOWARD THE INTERIOR. LATEST HRRR KEEPS THE TAF SITES DRY THROUGH
THE REMAINDER OF THE NIGHT. THEREFORE REMOVED VCSH MENTION. WINDS
WILL CONTINUE TO BE GENERALLY EASTERLY AT AROUND 10 KNOTS OR LESS
THROUGH THE MORNING AND INTO THE AFTERNOON HOURS BEFORE DECREASING
AND BACKING MORE TO THE NORTHEAST INTO THE EVENING HOURS. KAPF
SHOULD SEE A NORTHWEST FLOW COMING IN FROM THE GULF OF MEXICO
TOWARD THE EARLY TO MID AFTERNOON HOURS.
&&
.MARINE...
AS THE CENTER OF HIGH PRESSURE MOVES N/E AWAY FROM WATERS
TODAY...WINDS WILL CONTINUE TO SUBSIDE. NE WINDS TODAY WILL TURN
NORTHERLY INTO EARLY NEXT WEEK AS WEAK COLD FRONT/NEW HIPRES
SPREAD OVER THE WATERS. A MORE SIGNIFICANT FRONT ON TUESDAY MAY
RESULT IN INCREASING WINDS AND SEAS FOR WEDNESDAY AND THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 64 79 65 / 10 0 10 10
FORT LAUDERDALE 80 68 80 68 / 10 0 10 10
MIAMI 81 67 80 66 / 10 0 10 10
NAPLES 80 63 76 62 / 0 10 10 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 7 AM EST THIS MORNING FOR FLZ168-172-
173.
AM...HIGH RIP CURRENT RISK UNTIL 7 AM EST THIS MORNING FOR AMZ630.
GM...NONE.
&&
$$
SHORT TERM...23/SK
LONG TERM....23/SK
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
100 AM EST SAT DEC 6 2014
.AVIATION...
LIGHT SHOWERS CONTINUE TO EXIT THE EAST COAST SITES...PUSHING OFF
TOWARD THE INTERIOR. LATEST HRRR KEEPS THE TAF SITES DRY THROUGH
THE REMAINDER OF THE NIGHT. THEREFORE REMOVED VCSH MENTION. WINDS
WILL CONTINUE TO BE GENERALLY EASTERLY AT AROUND 10 KNOTS OR LESS
THROUGH THE MORNING AND INTO THE AFTERNOON HOURS BEFORE DECREASING
AND BACKING MORE TO THE NORTHEAST INTO THE EVENING HOURS. KAPF
SHOULD SEE A NORTHWEST FLOW COMING IN FROM THE GULF OF MEXICO
TOWARD THE EARLY TO MID AFTERNOON HOURS.
&&
.PREV DISCUSSION... /ISSUED 958 PM EST FRI DEC 5 2014/
UPDATE...
GUIDANCE SHOWS RELATIVELY DRIER AIR ARRIVING THROUGH THE LOW
LEVELS, BY SATURDAY MORNING, ACROSS SOUTH FLORIDA. THIS SHOULD
BRING AN END TO THE NEARLY PERPETUAL COASTAL AND OFFSHORE SHOWERS
BY LATE TONIGHT. OTHERWISE, THE OVERNIGHT WILL BE WARM AND HUMID.
PREV DISCUSSION... /ISSUED 303 PM EST FRI DEC 5 2014/
DISCUSSION...
THE UPPER LEVEL PATTERN CONSISTED OF HIGH PRESSURE OVER THE SOUTH
CENTRAL GULF OF MEXICO...AND A SHORTWAVE MOVING ACROSS THE
SOUTHERN PLAINS. AT THE SURFACE...STRONG HIGH PRESSURE WAS
CENTERED OVER NEW BRUNSWICK AND NOVA SCOTIA AND STRETCHED DOWN THE
EAST COAST. AN AREA OF LOW PRESSURE WAS BEGINNING TO DEVELOP OVER
NORTH TEXAS AND OKLAHOMA. EASTERLY FLOW WITH QUICK MOVING SHOWERS
WILL CONTINUE THROUGH THE AFTERNOON WITH HIGHS IN TEMPS IN THE LOW
80S.
TONIGHT...THE SHORTWAVE WILL PUSH EASTWARD AND SURFACE LOW
PRESSURE WILL MOVE QUICKLY NORTHEASTWARD INTO KENTUCKY. WINDS
WILL SHIFT TO THE NORTHEAST...AND DRIER AIR WILL BEGIN TO MOVE
INTO SOUTH FLORIDA. A FEW LIGHT SHOWERS IN THE EVENING SHOULD GIVE
WAY TO DRY CONDITIONS OVERNIGHT.
SATURDAY...AN AMPLIFIED PATTERN WILL TAKE PLACE ACROSS THE CONUS
AS A COUPLE SHORTWAVES PUSH INTO THE WEST COAST...WITH HIGH
PRESSURE EXTENDING FROM MEXICO INTO THE NORTHERN PLAINS AND
CANADA. AN UPPER LEVEL SHORTWAVE ACROSS THE SOUTHERN PLAINS WILL
DIG ACROSS THE SOUTHERN APPALACHIANS ON SATURDAY. A COLD FRONT
WILL PUSH INTO THE SOUTHEAST STATES. A LIGHTER NORTHEASTERLY FLOW
WITH MAINLY DRY CONDITIONS WILL PREVAIL. HIGHS ARE FORECAST TO BE
IN THE UPPER 70S TO LOWER 80S.
SUNDAY...A WEAK COLD FRONT WILL PUSH INTO NORTHERN AND CENTRAL
FLORIDA AS HIGH PRESSURE SURGES INTO THE EASTERN CONUS. THE FRONT
IS FORECAST TO BE MAINLY DRY AND BECOME DIFFUSE AS IT MOVES INTO
CENTRAL FLORIDA. A FEW SHOWERS MAY MOVE SOUTH AND SOUTHWEST OVER
THE ATLANTIC WATERS AND TOWARDS PALM BEACH COUNTY IN THE
AFTERNOON. OTHERWISE...DRY CONDITIONS WITH NEAR NORMAL
TEMPERATURES ARE EXPECTED.
MONDAY THROUGH THURSDAY...MODELS BEGIN TO DIVERGE BEGINNING ON
MONDAY. THE MODELS DIFFER ON THEIR HANDLING OF THE SHORTWAVES AND
THEIR PHASING AS THEY MOVE ACROSS THE GREAT LAKES AND SOUTHEAST ON
MONDAY. THE ECMWF KEEPS THE ACTIVITY MORE PHASED AND FURTHER NORTH
INITIALLY...AND THEN DEVELOPS A SURFACE LOW OVER THE GULF STREAM
AND MOVES IT UP THE EAST COAST. THIS PUSHES A STRONGER FRONT
THROUGH SOUTH FLORIDA ON TUESDAY...WITH NORTHWESTERLY FLOW THE
REST OF THE WEEK. THE GFS HAS A MUCH WEAKER LOW OVER THE EAST
COAST...AND HAS THE NORTHERN LOW OVER CANADA AS THE DOMINANT ONE.
THIS PUSHES THROUGH A MUCH WEAKER BOUNDARY...WITH HIGH PRESSURE
MOVING INTO THE SOUTHEAST BY THURSDAY. THIS WOULD RESULT IN
NORTHEASTERLY WINDS RETURNING TO THE REGION...ENDING THE COOLER
CONDITIONS. THE MOST RECENT RUN OF THE GFS HAS TRENDED
COOLER...BUT IS STILL WARMER THAN THE ECMWF. THE FORECAST WILL
LEAN MORE TOWARDS THE ECMWF SOLUTION...WITH HIGHS IN THE LOW 70S
AND LOWS MAINLY IN THE 50S.
MARINE...
HIGH PRESSURE WILL WEAKEN NORTH OF THE REGION ON SATURDAY AS A
COLD FRONT PUSHES INTO THE SOUTHEAST. WINDS WILL SHIFT TO THE
NORTHEAST. THE WEAK FRONT WILL PUSH INTO CENTRAL FLORIDA ON
SUNDAY...WITH WEAK NORTHEASTERLY FLOW CONTINUING. A FRONT IS
FORECAST TO PUSH THROUGH THE REGION EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 64 78 63 / 10 0 20 20
FORT LAUDERDALE 80 67 79 64 / 10 0 10 10
MIAMI 81 66 80 63 / 10 0 10 10
NAPLES 81 62 77 59 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 7 AM EST THIS MORNING FOR FLZ168-172-
173.
AM...HIGH RIP CURRENT RISK UNTIL 7 AM EST THIS MORNING FOR AMZ630.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
356 AM EST SAT DEC 6 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN
UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /TODAY/...
ISSUED AT 356 AM EST SAT DEC 6 2014
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 060900Z IND TAF UPDATE/...
RADAR TRENDS SUGGEST AT LAST THE END OF THE RAIN FALL IS NEAR.
BACK EDGE OF PRECIP APPEARS OVER EAST CENTRAL
ILLINOIS...PROGRESSING EASTWARD. OBS UPSTREAM STILL SHOW EXTENSIVE MVFR
TO IFR CONDITIONS. THUS BASED UPON LATEST TRENDS...EXPECT ONE MORE
PERIOD OF LIGHT RAIN AT IND AS THE BACK EDGE OF THE PRECIP WORKS
ACROSS THE STATE.
IMPROVEMENT TO VFR STILL APPEARS GRADUAL AND HEATING...MIXING AND
DRIER AIR ARRIVING ON NORTHERLY WINDS BY LATE THIS MORNING.
/DISCUSSION FOR THE 060600Z TAF ISSUANCE/...
ISSUED AT 1030 PM EST FRI DEC 5 2014
IFR AND WORSE CONDITIONS EXPECTED TO BE THE MOST PREVALENT FLIGHT
CATEGORIES THROUGH THE NIGHT.
RADAR TRENDS AND 02Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT WITH MOSTLY A LIGHT INTENSITY
BEFORE ENDING AFTER 09Z AT LAF...11Z AT HUF...12Z AT IND AND 13Z AT
BMG. SHOULD SEE CONDITIONS IMPROVE TO MVFR AFTER 12Z FROM NORTHWEST
TO SOUTHEAST. DO NOT EXPECT MUCH CLEARING OVERNIGHT SATURDAY
NIGHT...BUT COULD SEE A FEW BREAKS.
WINDS WILL BE BRIEFLY EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS. SPEED AND DIRECTION SHOULD BE SIMILAR DURING THE
DAY AND BECOME NORTHEAST 10 KNOTS OR LESS AFTER 00Z TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...MK/JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
340 AM EST SAT DEC 6 2014
.UPDATE...
AVIATION SECTIONS UPDATED.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST FRI DEC 5 2014
WIDESPREAD RAIN WILL CONTINUE THROUGH SATURDAY MORNING AS LOW
PRESSURE TRACKS THROUGH THE OHIO VALLEY. WITH THE EXCEPTION OF A FEW
SHOWERS MONDAY AS LOW PRESSURE PASSES THROUGH THE GREAT LAKES...DRY
AND SEASONABLY COOL WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 953 PM EST FRI DEC 5 2014
FORECAST IS IN GOOD SHAPE AND MADE NO MAJOR CHANGES. RAIN WILL
CONTINUE ACROSS THE AREA AS LOW PRESSURE MOVES SOUTH OF CENTRAL
INDIANA AND AN UPPER TROUGH MOVES INTO THE AREA. LATER TONIGHT AS
FORCING SHIFTS EAST...RAIN WILL DIMINISH SOME FROM NORTHWEST TO
SOUTHEAST. WARM AIR WILL REMAIN JUST SOUTH OF THE AREA.
PREVIOUS DISCUSSION FOLLOWS...
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON...AND EXPECT
ONLY TO INCREASE FURTHER IN INTENSITY OVER THE NEXT SEVERAL HOURS
WITH THE APPROACH OF LOW PRESSURE. TEMPS RANGED FROM THE UPPER 30S
NORTH TO UPPER 40S ACROSS FAR SOUTHERN COUNTIES AT 20Z.
A RAW WET NIGHT UPCOMING AS LOW PRESSURE CURRENTLY OVER THE OZARKS
TRACKS E/NE ALONG THE OHIO RIVER TONIGHT. MODEL GUIDANCE IN
EXCELLENT AGREEMENT ON SPREADING ANOTHER WAVE OF HEAVIER CONVECTIVE
RAINFALL INTO THE FORECAST AREA LATE THIS AFTERNOON THROUGH THE
EVENING. FOCUS FOR THE HEAVIEST RAINS REMAINS ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA BETWEEN 00-06Z AS STRONGER LOW LEVEL
CONVERGENCE ALIGNS ALONG THE 850MB BAROCLINIC ZONE AND AREA OF
ENHANCED ISENTROPIC LIFT. A LOW LEVEL JET OVER THE TENNESSEE VALLEY
WILL TRANSPORT DEEPER MOISTURE UP INTO THE REGION AS WELL. APPROACH
OF THE UPPER WAVE WILL PROMOTE DIFFLUENCE ALOFT...FURTHER ASSISTING
LIFT FOR EFFICIENT RAINFALL.
THERE IS SOME WEAK ELEVATED INSTABILITY PRESENT...BUT JUST DO NOT
SEE ENOUGH TO JUSTIFY AN ISOLATED THUNDER MENTION TONIGHT. BETTER
THREAT FOR A FEW STORMS WILL EXIST CLOSER TO THE SURFACE LOW TRACK
ALONG THE OHIO RIVER. POTENTIAL EXISTS FOR UP TO 1.5 INCHES ALONG
AND SOUTH OF I-70 BY SATURDAY MORNING. WILL CONTINUE WITH
CATEGORICAL POPS TONIGHT. HEAVIER RAINS WILL BEGIN TO SHIFT EAST
AFTER 06Z...BUT LINGERING MID LEVEL DEFORMATION BAND WILL MAINTAIN
LIGHTER RAIN FOR MUCH OF THE REST OF THE NIGHT. HRRR AND WRF-NMM/ARW
BRING BACK END OF THE RAIN INTO THE NORTHERN WABASH VALLEY AROUND OR
SHORTLY BEFORE DAYBREAK. WINDS WILL PICK UP LATE TONIGHT AS WELL AS
A BRISK NORTHERLY FLOW DEVELOPS BEHIND THE SURFACE LOW.
TEMPS...MOS APPEARS A BIT AGGRESSIVE IN BRINGING THE COLDER AIR IN
PRIOR TO 12Z. GENERALLY TRENDED A DEGREE OR TWO ABOVE MAVMOS
GUIDANCE WITH LOWS RANGING FROM THE MID 30S NORTH TO LOWER 40S
SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
FORECAST CHALLENGES FOCUS ON THE DEPARTURE OF THE RAIN SATURDAY
MORNING...AND POSSIBILITY FOR LIGHT PRECIP WITH A WEAK SYSTEM ON
MONDAY.
THE UPPER WAVE AND SURFACE LOW WILL CONTINUE TO MOVE AWAY TO THE
EAST WITH LIGHT RAIN ENDING FROM NORTHWEST TO SOUTHEAST DURING THE
MORNING. WRF DATA LOOKS VERY GOOD WITH RESPECT TO TIMING AND WAS
UTILIZED FOR MORNING POPS. EXPECT THE ENTIRE FORECAST AREA WILL BE
FREE OF PRECIP AROUND MIDDAY. DRIER AIR ALOFT WILL QUICKLY ADVECT
INTO THE REGION WITH STRONG HIGH PRESSURE SATURDAY AFTERNOON...BUT
RH PROGS AND MODEL SOUNDINGS INDICATE LINGERING LOW LEVEL MOISTURE
REMAINING TRAPPED BENEATH A SLOWLY WEAKENING INVERSION. EXPECT LOWER
CLOUDS TO LINGER AS A RESULT...WITH FULL CLEARING OF THE CLOUD DECK
NOT COMING UNTIL SATURDAY EVENING AS STRONGER SUBSIDENCE ENABLES
DRIER AIR TO INFILTRATE THE NEAR SURFACE LAYER.
HIGH PRESSURE RIDGE WILL DRIFT SLOWLY THROUGH THE GREAT LAKES
SATURDAY NIGHT AND SUNDAY...PROVIDING A DRY COOL E/NE FLOW ACROSS
CENTRAL INDIANA. EXPECT ABUNDANT SUNSHINE ON SUNDAY...WHICH
AMAZINGLY WOULD BE THE FIRST DAY WITH EXTENDED SUNSHINE AND BLUE
SKIES FOR MANY SINCE NOVEMBER 21.
MID AND HIGH LEVEL CLOUDS WILL INCREASE AGAIN BEGINNING SUNDAY NIGHT
WITH SKIES BECOMING FAIRLY CLOUDY MONDAY AS AN UPPER WAVE AND
ASSOCIATED LOW PRESSURE ASSOCIATED WITH THE NORTHERN JET STREAM
TRACK INTO THE GREAT LAKES. DESPITE INCREASING ISENTROPIC LIFT AND
HINT OF SOME DEVELOPING LOW LEVEL CONVERGENCE...MOISTURE PROFILES
LARGELY LOOK UNIMPRESSIVE AND FOCUSED PRIMARILY ABOVE 10KFT. HAVE A
HARD TIME JUSTIFYING MUCH HIGHER THAN LOW CHANCE POPS AS THE SYSTEM
PASSES THROUGH. ENOUGH COLD AIR PRESENT THAT MAY SEE A MIXTURE OF
LIGHT SNOW AND RAIN IN THE NORTHERN WABASH VALLEY MONDAY MORNING
BEFORE PRECIP TRANSITIONS TO ALL RAIN. REGARDLESS...QPF VALUES AT
THIS POINT LOOK NO HIGHER THAN A FEW HUNDREDTHS.
TEMPS...LEANED CLOSER TO COOLER METMOS FOR SATURDAY HIGHS WITH THE
LINGER LOW CLOUDS. WENT NEAR MOS FOR SUNDAY THEN UNDERCUT FOR MONDAY
AND LEANED CLOSER TO ECMWF ENSEMBLE MEAN TEMPS. DESPITE WARM
ADVECTION AHEAD OF THE SURFACE LOW...MEXMOS LOOKS TOO AGGRESSIVE
WITH WARMING TEMPS. LEANED TOWARDS WARMER METMOS FOR SATURDAY NIGHT
LOWS AND TOOK A MODEL BLEND FOR SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 060900Z IND TAF UPDATE/...
RADAR TRENDS SUGGEST AT LAST THE END OF THE RAIN FALL IS NEAR.
BACK EDGE OF PRECIP APPEARS OVER EAST CENTRAL
INDIANA...PROGRESSING EASTWARD. OBS UPSTREAM STILL SHOW EXTENSIVE
MVFR TO IFR CONDITIONS. THUS BASED UPON LATEST TRENDS...EXPECT ONE
MORE PERIOD OF LIGHT RAIN AT IND AS THE BACK EDGE OF THE PRECIP
WORKS ACROSS THE STATE.
IMPROVEMENT TO VFR STILL APPEARS GRADUAL AND HEATING...MIXING AND
DRIER AIR ARRIVING ON NORTHERLY WINDS BY LATE THIS MORNING.
/DISCUSSION FOR THE 060600Z TAF ISSUANCE/...
ISSUED AT 1030 PM EST FRI DEC 5 2014
IFR AND WORSE CONDITIONS EXPECTED TO BE THE MOST PREVALENT FLIGHT
CATEGORIES THROUGH THE NIGHT.
RADAR TRENDS AND 02Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT WITH MOSTLY A LIGHT INTENSITY
BEFORE ENDING AFTER 09Z AT LAF...11Z AT HUF...12Z AT IND AND 13Z AT
BMG. SHOULD SEE CONDITIONS IMPROVE TO MVFR AFTER 12Z FROM NORTHWEST
TO SOUTHEAST. DO NOT EXPECT MUCH CLEARING OVERNIGHT SATURDAY
NIGHT...BUT COULD SEE A FEW BREAKS.
WINDS WILL BE BRIEFLY EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS. SPEED AND DIRECTION SHOULD BE SIMILAR DURING THE
DAY AND BECOME NORTHEAST 10 KNOTS OR LESS AFTER 00Z TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/50
SHORT TERM...RYAN
LONG TERM....PUMA
AVIATION...MK/JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
243 AM EST SAT DEC 6 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST FRI DEC 5 2014
WIDESPREAD RAIN WILL CONTINUE THROUGH SATURDAY MORNING AS LOW
PRESSURE TRACKS THROUGH THE OHIO VALLEY. WITH THE EXCEPTION OF A FEW
SHOWERS MONDAY AS LOW PRESSURE PASSES THROUGH THE GREAT LAKES...DRY
AND SEASONABLY COOL WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 953 PM EST FRI DEC 5 2014
FORECAST IS IN GOOD SHAPE AND MADE NO MAJOR CHANGES. RAIN WILL
CONTINUE ACROSS THE AREA AS LOW PRESSURE MOVES SOUTH OF CENTRAL
INDIANA AND AN UPPER TROUGH MOVES INTO THE AREA. LATER TONIGHT AS
FORCING SHIFTS EAST...RAIN WILL DIMINISH SOME FROM NORTHWEST TO
SOUTHEAST. WARM AIR WILL REMAIN JUST SOUTH OF THE AREA.
PREVIOUS DISCUSSION FOLLOWS...
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON...AND EXPECT
ONLY TO INCREASE FURTHER IN INTENSITY OVER THE NEXT SEVERAL HOURS
WITH THE APPROACH OF LOW PRESSURE. TEMPS RANGED FROM THE UPPER 30S
NORTH TO UPPER 40S ACROSS FAR SOUTHERN COUNTIES AT 20Z.
A RAW WET NIGHT UPCOMING AS LOW PRESSURE CURRENTLY OVER THE OZARKS
TRACKS E/NE ALONG THE OHIO RIVER TONIGHT. MODEL GUIDANCE IN
EXCELLENT AGREEMENT ON SPREADING ANOTHER WAVE OF HEAVIER CONVECTIVE
RAINFALL INTO THE FORECAST AREA LATE THIS AFTERNOON THROUGH THE
EVENING. FOCUS FOR THE HEAVIEST RAINS REMAINS ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA BETWEEN 00-06Z AS STRONGER LOW LEVEL
CONVERGENCE ALIGNS ALONG THE 850MB BAROCLINIC ZONE AND AREA OF
ENHANCED ISENTROPIC LIFT. A LOW LEVEL JET OVER THE TENNESSEE VALLEY
WILL TRANSPORT DEEPER MOISTURE UP INTO THE REGION AS WELL. APPROACH
OF THE UPPER WAVE WILL PROMOTE DIFFLUENCE ALOFT...FURTHER ASSISTING
LIFT FOR EFFICIENT RAINFALL.
THERE IS SOME WEAK ELEVATED INSTABILITY PRESENT...BUT JUST DO NOT
SEE ENOUGH TO JUSTIFY AN ISOLATED THUNDER MENTION TONIGHT. BETTER
THREAT FOR A FEW STORMS WILL EXIST CLOSER TO THE SURFACE LOW TRACK
ALONG THE OHIO RIVER. POTENTIAL EXISTS FOR UP TO 1.5 INCHES ALONG
AND SOUTH OF I-70 BY SATURDAY MORNING. WILL CONTINUE WITH
CATEGORICAL POPS TONIGHT. HEAVIER RAINS WILL BEGIN TO SHIFT EAST
AFTER 06Z...BUT LINGERING MID LEVEL DEFORMATION BAND WILL MAINTAIN
LIGHTER RAIN FOR MUCH OF THE REST OF THE NIGHT. HRRR AND WRF-NMM/ARW
BRING BACK END OF THE RAIN INTO THE NORTHERN WABASH VALLEY AROUND OR
SHORTLY BEFORE DAYBREAK. WINDS WILL PICK UP LATE TONIGHT AS WELL AS
A BRISK NORTHERLY FLOW DEVELOPS BEHIND THE SURFACE LOW.
TEMPS...MOS APPEARS A BIT AGGRESSIVE IN BRINGING THE COLDER AIR IN
PRIOR TO 12Z. GENERALLY TRENDED A DEGREE OR TWO ABOVE MAVMOS
GUIDANCE WITH LOWS RANGING FROM THE MID 30S NORTH TO LOWER 40S
SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
FORECAST CHALLENGES FOCUS ON THE DEPARTURE OF THE RAIN SATURDAY
MORNING...AND POSSIBILITY FOR LIGHT PRECIP WITH A WEAK SYSTEM ON
MONDAY.
THE UPPER WAVE AND SURFACE LOW WILL CONTINUE TO MOVE AWAY TO THE
EAST WITH LIGHT RAIN ENDING FROM NORTHWEST TO SOUTHEAST DURING THE
MORNING. WRF DATA LOOKS VERY GOOD WITH RESPECT TO TIMING AND WAS
UTILIZED FOR MORNING POPS. EXPECT THE ENTIRE FORECAST AREA WILL BE
FREE OF PRECIP AROUND MIDDAY. DRIER AIR ALOFT WILL QUICKLY ADVECT
INTO THE REGION WITH STRONG HIGH PRESSURE SATURDAY AFTERNOON...BUT
RH PROGS AND MODEL SOUNDINGS INDICATE LINGERING LOW LEVEL MOISTURE
REMAINING TRAPPED BENEATH A SLOWLY WEAKENING INVERSION. EXPECT LOWER
CLOUDS TO LINGER AS A RESULT...WITH FULL CLEARING OF THE CLOUD DECK
NOT COMING UNTIL SATURDAY EVENING AS STRONGER SUBSIDENCE ENABLES
DRIER AIR TO INFILTRATE THE NEAR SURFACE LAYER.
HIGH PRESSURE RIDGE WILL DRIFT SLOWLY THROUGH THE GREAT LAKES
SATURDAY NIGHT AND SUNDAY...PROVIDING A DRY COOL E/NE FLOW ACROSS
CENTRAL INDIANA. EXPECT ABUNDANT SUNSHINE ON SUNDAY...WHICH
AMAZINGLY WOULD BE THE FIRST DAY WITH EXTENDED SUNSHINE AND BLUE
SKIES FOR MANY SINCE NOVEMBER 21.
MID AND HIGH LEVEL CLOUDS WILL INCREASE AGAIN BEGINNING SUNDAY NIGHT
WITH SKIES BECOMING FAIRLY CLOUDY MONDAY AS AN UPPER WAVE AND
ASSOCIATED LOW PRESSURE ASSOCIATED WITH THE NORTHERN JET STREAM
TRACK INTO THE GREAT LAKES. DESPITE INCREASING ISENTROPIC LIFT AND
HINT OF SOME DEVELOPING LOW LEVEL CONVERGENCE...MOISTURE PROFILES
LARGELY LOOK UNIMPRESSIVE AND FOCUSED PRIMARILY ABOVE 10KFT. HAVE A
HARD TIME JUSTIFYING MUCH HIGHER THAN LOW CHANCE POPS AS THE SYSTEM
PASSES THROUGH. ENOUGH COLD AIR PRESENT THAT MAY SEE A MIXTURE OF
LIGHT SNOW AND RAIN IN THE NORTHERN WABASH VALLEY MONDAY MORNING
BEFORE PRECIP TRANSITIONS TO ALL RAIN. REGARDLESS...QPF VALUES AT
THIS POINT LOOK NO HIGHER THAN A FEW HUNDREDTHS.
TEMPS...LEANED CLOSER TO COOLER METMOS FOR SATURDAY HIGHS WITH THE
LINGER LOW CLOUDS. WENT NEAR MOS FOR SUNDAY THEN UNDERCUT FOR MONDAY
AND LEANED CLOSER TO ECMWF ENSEMBLE MEAN TEMPS. DESPITE WARM
ADVECTION AHEAD OF THE SURFACE LOW...MEXMOS LOOKS TOO AGGRESSIVE
WITH WARMING TEMPS. LEANED TOWARDS WARMER METMOS FOR SATURDAY NIGHT
LOWS AND TOOK A MODEL BLEND FOR SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 060600Z TAF ISSUANCE/...
ISSUED AT 1030 PM EST FRI DEC 5 2014
IFR AND WORSE CONDITIONS EXPECTED TO BE THE MOST PREVALENT FLIGHT
CATEGORIES THROUGH THE NIGHT.
RADAR TRENDS AND 02Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT WITH MOSTLY A LIGHT INTENSITY
BEFORE ENDING AFTER 09Z AT LAF...11Z AT HUF...12Z AT IND AND 13Z AT
BMG. SHOULD SEE CONDITIONS IMPROVE TO MVFR AFTER 12Z FROM NORTHWEST
TO SOUTHEAST. DO NOT EXPECT MUCH CLEARING OVERNIGHT SATURDAY
NIGHT...BUT COULD SEE A FEW BREAKS.
WINDS WILL BE BRIEFLY EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS. SPEED AND DIRECTION SHOULD BE SIMILAR DURING THE
DAY AND BECOME NORTHEAST 10 KNOTS OR LESS AFTER 00Z TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/50
SHORT TERM...RYAN
LONG TERM....PUMA
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 PM MST FRI DEC 5 2014
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1246 PM MST FRI DEC 5 2014
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW RIDGING
BUILDING ACROSS INTER-MOUNTAIN WEST...WITH A SHORTWAVE TROUGH
CENTERED OVER EASTERN KANSAS. SUBSIDENCE/CLEARING IS IN PLACE
OVER OUR CWA. AT THE THE SURFACE...PRE FRONTAL LOW PRESSURE IS IN
PLACE ACROSS KANSAS AND EASTERN COLORADO WITH A WEAK COLD FRONT
OVER SOUTHERN NEBRASKA. AHEAD OF THE COLD FRONT TEMPERATURES HAVE
WARMED TO NEAR 60 DEGREES OVER MUCH OF THE CWA WITH A WELL MIXED
AIR MASS AND SURFACE TROUGH IN PLACE.
DRY FORECAST CONTINUES THROUGH SATURDAY AFTERNOON AS RIDGE
TRANSITIONS EASTWARD...AND SUBSIDENT/DRY AIR MASS LINGERS.
THIS AFTERNOON-TONIGHT...THE COLD FRONT OVER NEBRASKA WILL DROP
SOUTH THIS LATE THIS AFTERNOON AND EVENING WITH SURFACE HIGH
PRESSURE SETTLING IN FROM THE NORTHERN PLAINS. A COOLER/DRIER AIR
MASS WILL ACCOMPANY THIS HIGH PRESSURE SYSTEM...RETURNING
OVERNIGHT LOWS TO SEASONAL VALUES AROUND 20F. NAM/SREF CONTINUE TO
HINT AT SURFACE RH VALUES APPROACHING SATURATION AND POSSIBLE FOG
DEVELOPMENT. SOUNDINGS INDICATE THIS WILL BE VERY SHALLOW MOIST
LAYER...AND A DRY BL WILL GENERALLY INHIBIT FOG/STRATUS
DEVELOPMENT TONIGHT. HRRR/RAP CURRENTLY SHOWING NO FOG DEVELOPMENT
OVER OUR CWA. WHILE WE COULD SEE SOME SHALLOW FOG DEVELOPMENT...AT
THIS POINT CONFIDENCE IS JUST TOO LOW TO ADD.
SATURDAY...SHORTWAVE RIDING WILL TRANSITION THROUGH THE PLAINS ON
SATURDAY...WITH A SHORTWAVE TROUGH MOVING OUT OF THE GREAT BASIN
TOWARDS THE CENTRAL ROCKIES SATURDAY AFTERNOON. SW FLOW ALOFT WILL
DEVELOP BY SATURDAY AFTERNOON BETWEEN THESE FEATURES...WITH
INCREASING MID TO HIGH CLOUD COVER THROUGH THE DAY FROM THE WEST
TO THE EAST. LEE TROUGH AND SOUTHERLY FLOW WILL DEVELOP IN
RESPONSE TO THIS SHIFT IN FLOW ALOFT...SUPPORTING WAA ACROSS OUR
CWA AS THE SURFACE HIGH RETREATS EASTWARD.
NOT A LOT OF CONFIDENCE IN WHICH WILL WIN OUT: WAA WITH SOUTHERLY
FLOW OR LIMITED DIURNAL HEATING DUE TO INCREASING CLOUD COVER. I
ONLY MADE MINOR ADJUSTMENTS TO HIGH TEMP FORECAST...WHICH HAS
HIGHS NEAR 50 IN THE WEST AND THE MID 40S IN THE EAST. I COULD SEE
LOCATIONS IN THE WEST APPROACHING THE MID 50S IF CLOUD COVER HAS
MINIMAL IMPACT AND WE ACHIEVE FULL DAYTIME MIXING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 222 PM MST FRI DEC 5 2014
AN UPPER TROUGH WILL MOVE INTO THE CENTRAL PLAINS SATURDAY NIGHT
FOLLOWED BY NORTHWEST FLOW SUNDAY. A RIDGE WILL MOVE EAST FROM THE
ROCKIES AND INTO THE PLAINS MONDAY. A SURFACE TROUGH WILL BE OVER
EASTERN COLORADO SATURDAY NIGHT AND THEN SHIFT EAST SUNDAY. SURFACE
HIGH PRESSURE WILL MOVE INTO THE CENTRAL PLAINS SUNDAY AND MONDAY.
THE UPPER TROUGH THAT COMES THROUGH THE FA SATURDAY NIGHT WILL BE
LACKING FOR MOISTURE. MOISTURE IMPROVES SOME AS THE SYSTEM EXITS
THE FAR EASTERN FA SUNDAY MORNING. FORECAST SOUNDINGS ACROSS THE FA
SATURDAY NIGHT SHOW CLOUD BASES FROM 8 TO 11KFT. FORECAST SOUNDINGS
SHOW SATURATION NEAR THE SURFACE EAST OF THE COLORADO LINE FOR
STRATUS/FOG AND LIGHT DRIZZLE WITH SURFACE TEMPERATURES ABOVE
FREEZING. SUBSIDENCE MOVES INTO THE FA LATE SUNDAY MORNING AND
CONTINUES THROUGH MONDAY. CONSEQUENTLY POPS WILL BE NIL FROM
SATURDAY NIGHT THROUGH MONDAY.
MIN TEMPERATURES SATURDAY AND SUNDAY NIGHTS WILL VARY FROM THE UPPER
20S TO AROUND 30. MAX TEMPERATURES SUNDAY SHOULD RANGE FROM 45 TO
50. MAX TEMPERATURES MONDAY SHOULD WARM TO THE MID AND UPPER 50S.
IN THE EXTENDED...(MONDAY NIGHT THROUGH FRIDAY)...A RIDGE WILL
PERSIST OVER THE CENTRAL PLAINS THROUGH THURSDAY AND THEN SHIFT EAST
FRIDAY WITH ZONAL FLOW EAST OF THE ROCKIES. SURFACE HIGH PRESSURE
WILL CONTINUE OVER THE CENTRAL PLAINS THROUGH TUESDAY. A TROUGH
MOVES INTO EASTERN COLORADO THURSDAY AND FRIDAY AS HIGH PRESSURE
DRIFTS EAST.
THE GFS BRINGS A SHORTWAVE THROUGH TUESDAY NIGHT WHILE THE ECMWF
KEEPS IT MUCH FURTHER NORTH. ALSO GFS SOUNDINGS SHOW VERY SHALLOW
MOISTURE WITH THE SYSTEM. FOR NOW WILL KEEP SILENT POPS FOR TUESDAY
NIGHT. AS A RESULT THE ENTIRE EXTENDED FORECAST WILL BE DRY WITH NO
OTHER SIGNIFICANT FORCING FOR THE REMAINING PERIODS.
MAX TEMPERATURES WILL VARY FROM THE MID 50S TO THE MID AND UPPER 50S
THURSDAY AND FRIDAY. MIN TEMPERATURES WILL COOL TO THE UPPER 20S TO
AROUND 30.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1000 PM MST FRI DEC 5 2014
FOR KGLD AND KMCK...VFR THROUGH THE PERIOD. SFC HIGH CURRENTLY
INFLUENCING THE AREAS WEATHER WILL SLOWLY MOVE EAST OVERNIGHT WITH
LOW PRESSURE DEEPENING ALONG THE FRONT RANGE. THE PRESSURE
GRADIENT BETWEEN THE TWO WILL SLOWLY STRENGTHEN DURING THE DAY
SATURDAY. LIGHT/VARIABLE WINDS AT TAF ISSUANCE THROUGH ROUGHLY
15Z. AFTER 15Z SOUTHEAST WINDS SLOWLY INCREASE DURING THE DAY
WITH GUSTS AROUND 20-25KTS AT KGLD BY 20Z...CONTINUING THROUGH
THE REST OF THE TAF PERIOD. AT KMCK ONLY 10KT WINDS FROM THE
SOUTHEAST EXPECTED AFTER 21Z. MID AND HIGH CLOUDS INCREASE FROM
THE SOUTHWEST AFTER 17Z.
WILL NEED TO MONITOR CIGS/VIS AT KMCK AT THE TAIL END OF THE TAF
PERIOD AS ABUNDANT BOUNDARY LAYER MOISTURE MOVES TOWARD THE
TERMINAL FROM THE EAST. CURRENT INDICATIONS SUGGEST MVFR/IFR
CONDITIONS POSSIBLE JUST AFTER 06Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...99
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1157 PM CST FRI DEC 5 2014
.AVIATION...
FOR THE 06/06Z TAFS...A FEW SHWRS CONTINUE TO FORM ALONG AND JUST
AHEAD OF A COLD FRONT WHICH IS JUST EAST OF A LINE FROM TXK...GGG
TO JSO. SHWRS AND POSSIBLY A FEW EMBEDDED TSTMS WILL LIKELY
INCREASE AFTER MIDNIGHT THROUGH EARLY SATURDAY MORNING WITH
FRONTAL FORCING. MVFR/IFR CIGS WILL GRADUALLY OVERTAKE THE REGION
BOTH AHEAD OF AND BEHIND THE FRONT...PERSISTING THROUGH THE
MORNING HOURS SATURDAY AND POSSIBLY EXTENDING INTO THE EARLY
AFTERNOON HOURS AT OUR ERN TERMINAL SITES. LIGHT SOUTH WINDS AHEAD
OF THE FRONT WILL QUICKLY SHIFT N/NW BEHIND THE FRONT WITH SPEEDS
NEAR 10 KTS IN ADDITION TO A FEW HIGHER GUSTS. /19/
&&
.PREV DISCUSSION... /ISSUED 856 PM CST FRI DEC 5 2014/
DISCUSSION...
FRONTAL BOUNDARY AS OF 8 PM WAS ORIENTED NEAR A FYV...FSM...
PRX...SEP LINE MOVING SLOWLY SOUTH AND EAST. A NARROW LINE OF
MOSTLY SHOWERS HAD DEVELOPED ALONG AND JUST AHEAD OF THIS BOUNDARY
ACROSS PORTIONS OF CENTRAL/SW AR INTO EXTREME SE OK AND PORTIONS
OF NE TX. THIS LINE LOOKED A LITTLE BETTER A COUPLE OF HOURS AGO
BUT WITH THE LOSS OF DAYTIME HEATING AND INSTABILITY LOOKING VERY
WEAK...NOT EXPECTING MUCH IN THE OF CONVECTION BUT CANNOT RULE
OUT AN ISOLATED LIGHTNING STRIKE THROUGHOUT THE NIGHT.
FRONT IS EXPECTED TO BE NEAR THE I-30 CORRIDOR BY MIDNIGHT AND
JUST EAST OF A LFK...SHV...ELD LINE BY 12Z IN THE MORNING. FOR THE
UPDATE...HAVE ORIENTED POPS HIGHEST ACROSS OUR EASTERN MOST ZONES
FOR THE REMAINDER OF THE NIGHT. THIS IS IN GOOD OVERALL AGREEMENT
WITH THE HRRR AND THE 00Z NAM OUTPUT WHICH PUTS THE BEST QPF
PROBABILITIES WHERE THE HIGHER MOISTURE CONTENT RESIDES.
ALSO ADDED THE LIKELIHOOD OF PATCHY DENSE FOG ACROSS ALL BUT OUR
EXTREME NW ZONES. TEMP/DEWPOINT DEPRESSIONS ARE VERY LOW ATTM AND
WITH THE VERY MOIST LOW LEVEL ATMOSPHERE PRESENT...UNTIL THE FRONT
COMES THROUGH...FOG IS A PRETTY GOOD BET OVERNIGHT.
NO ADDITIONAL CHANGES WERE NECESSARY THIS EVENING...UPDATE OUT
SHORTLY...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 62 68 43 54 42 / 40 0 0 10 10
MLU 62 68 42 55 41 / 50 10 0 10 10
DEQ 52 61 39 49 38 / 10 0 0 10 10
TXK 55 64 41 51 39 / 30 0 0 10 10
ELD 58 68 41 51 39 / 50 0 0 10 10
TYR 55 66 45 55 42 / 20 0 0 20 20
GGG 57 68 43 54 42 / 20 0 0 10 10
LFK 62 71 48 57 46 / 20 10 10 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
334 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION TODAY.
&&
.NEAR TERM /THROUGH TODAY/...
NO MAJOR CHANGES WERE NEEDED FOR THE PRE DAWN UPDATE AS LOW PRES
MOVG UP THE OHIO VALLEY WL MAINTAIN RAIN ACROSS THE REGION INTO
THE AFTERNOON.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV THROUGH THAT
TROF IS CURRENTLY PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD
PROGRESS OF WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO
FOREGO PROBLEM CONTRIBUTION FOR THE UPR OH REGION. NEVERTHELESS...PCPN
CHCS WL INCRS ON MON NGT INTO TUESDAY AS ISENTROPIC LIFT...WARM
MOIST ADVCTN DVLPS ON THE ERN FLANKS OF THE HIGH AMPLITUDE ERN
CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A DEEP ERN CONUS TROF IS PROGGED TO PERSIST THRU ERLY INTO THE
WKEND AS COASTAL SFC LOW PRES TRACKS UP THE E COAST. FCST SNW
SHWR CHCS INTO WED NGT UNTIL THE LOW AND UPR SPPRT EXITS THE RGN.
A WK SRTWV IS PROGGED TO ROTATE THRU THE GT LKS ARND THE MAIN TROF
FRI THOUGH WITH BLDG SFC HIGH PRES UNDER THE TROF KEPT A DRY FCST.
BLO SEASONAL TEMPS SHOULD RTN TO NR AVG BY LT WK.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
WDSPRD IFR/OCNL LIFR CONDS ARE EXPD TO CONT TDA AS UPR OH VLY LOW
PRES BRINGS RAIN TO THE RGN. INCRG NRLY WNDS AND COND IMPROVEMENT
TO LOW END MVFR ARE EXPD BY THIS EVE AS THE SFC LOW SHIFTS E AND
RAIN TAPERS OFF.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RSTRNS ARE EXPD MON NGT THRU WED AS LOW PRES BRINGS SNW SHWRS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/07
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1248 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION TODAY.
&&
.NEAR TERM /THROUGH TODAY/...
NO MAJOR CHANGES WERE NEEDED FOR THE POST MIDNGT UPDATE AS LOW
PRES MOVG UP THE OHIO VALLEY WL MAINTAIN RAIN ACROSS THE REGION
INTO THE AFTERNOON.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV IS CURRENTLY
PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD PROGRESS OF
WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO FOREGO
PROBLEMS FOR THE UPR OH REGION. NEVERTHELESS...PCPN CHCS WL INCRS
ON MON NGT INTO TUESDAY AS ISENTROPIC LIFT...WARM MOIST ADVCTN
DVLPS ON THE ERN FLANKS OF THE HIGH AMPLITUDE ERN CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
CHANGES TO THE EXTENDED WERE BASED ON A BLEND OF THE NEW WPC PROGS
AND 12Z GFS WHICH HAVE SHIFTED TOWARD THE 00Z ECMWF SOLUTION MID
WEEK WITH CLSOED LOW DEVELOPING OVER THE NORTHEAST AND A COASTAL
STORM POSSIBLE INTO NEW ENGLAND. MID WEEK TEMPERATURES ADJUSTED
COLDER WITH SNOW SHOWERS IN NORTHWEST FLOW. DRY AND SEASONAL LATE WEEK.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WDSPRD IFR/OCNL LIFR CONDS ARE EXPD TO CONT TDA AS UPR OH VLY LOW
PRES BRINGS RAIN TO THE RGN. INCRG NRLY WNDS AND COND IMPROVEMENT
TO LOW END MVFR ARE EXPD BY THIS EVE AS THE SFC LOW SHIFTS E AND
RAIN TAPERS OFF.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RSTRNS ARE EXPD MON NGT THRU WED AS LOW PRES BRINGS SNW SHWRS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/07
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1146 PM CST FRI DEC 5 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 218 PM CST FRI DEC 5 2014
THE SHORT TERM FORECAST THROUGH SATURDAY IS RELATIVELY QUIET IN
TERMS OF MAJOR WEATHER ISSUES. MILD TEMPERATURES THIS AFTERNOON
WILL BE TEMPERED A BIT IN THE WAKE OF FRONTAL BOUNDARY PASSING
THROUGH THE FORECAST AREA AT THIS TIME. TEMPERATURES WILL ACTUALLY
BE NEAR NORMAL TONIGHT AND SATURDAY...THOUGH IT WILL FEEL QUITE A
BIT COOLER TONIGHT WITH UPPER TEENS AND 20S. DECENT MODEL AGREEMENT
WITH SOME LOWER CLOUDS TRYING TO SNEAK BACK WEST TONIGHT AND PUSH
INTO THE HIGHWAY 81 CORRIDOR AREA TOWARD DAWN SATURDAY AND LINGER
INTO THE MORNING. HAVE INCREASED CLOUDS IN THAT AREA...AND ADDED A
BIT OF PATCHY FOG FOG WHICH ALIGNS WELL WITH WFOS OMAHA AND TOPEKA
FORECAST. SOME CONCERN OF FOG IN THE NORTHWEST PART OF THE FORECAST
AREA...WHERE WINDS TURN NEARLY CALM. HRRR HINTS AT LOWER CLOUDS AND
VISIBILITY OVER PARTS OF THE SANDHILLS. WILL HOLD OFF FOR NOW BUT
WORTH NOTING HEADING INTO TONIGHT. BEYOND THAT...SATURDAY WILL SEE
MID/HIGH CLOUDS START TO INCREASE FROM THE WEST IN THE AFTERNOON AS
WARM ADVECTION INCREASES AHEAD OF NEXT WEATHER SYSTEM ON SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 218 PM CST FRI DEC 5 2014
GUIDANCE SUGGESTS THE LONG-TERM FORECAST PERIOD WILL START OFF WITH
UPPER TROPOSPHERIC RIDGING OVER THE CENTRAL CONUS AND A SUBTLE
TROUGH AXIS JUST WEST OF THE ROCKY MOUNTAINS AT 00Z SUNDAY. THIS
TROUGH AXIS IS EXPECTED TO SHIFT EAST SATURDAY NIGHT INTO
SUNDAY...WITH THIS TROUGH AXIS LIKELY CLEARING OUR AREA DURING THE
DAY SUNDAY. NORTHWESTERLY UPPER TROPOSPHERIC FLOW IS THEN EXPECTED
TO OVERTAKE THE CENTRAL CONUS THROUGH MUCH OF THE REMAINDER OF THE
LONG-TERM FORECAST PERIOD AS UPPER TROPOSPHERIC TROUGHING
STRENGTHENS OVER THE EASTERN CONUS AND RIDGING BUILDS ACROSS THE
WEST.
ALTHOUGH UNCERTAINTY REMAINS...THERE REMAIN HINTS AT A BRIEF PERIOD
OF PRECIPITATION PRODUCTION ACROSS THE CENTRAL PLAINS ON SUNDAY AS
TROPOSPHERIC MOISTURE AND UPPER TROPOSPHERIC THERMAL ADVECTION
INCREASES AHEAD OF THE APPROACHING TROUGH AXIS. QPF FIELDS FROM THE
NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL CONTINUE TO SUGGEST
LIGHT PRECIPITATION WILL BE REALIZED ACROSS PORTIONS OF OUR CWA ON
SUNDAY AND AS A RESULT...CONTINUED WITH POPS...ALBEIT LOW...ACROSS
MUCH OF THE AREA ON SUNDAY. UNFORTUNATELY PRECIPITATION TYPE REMAINS
QUESTIONABLE AS FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE
CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST AN ELEVATED WARM
LAYER WILL LIKELY PROVIDE LIQUID PRECIPITATION WHILE SURFACE
TEMPERATURE READINGS FALL TO NEAR OR BELOW FREEZING AROUND DAYBREAK
SUNDAY. PREVIOUS SHIFT WENT AHEAD AND INSERTED A MENTION OF LIGHT
FREEZING RAIN FOR A TIME SUNDAY MORNING AND AT THIS TIME...SEE NO
REASON TO REMOVE THIS WORDING. GIVEN ALL THIS...A SLIGHT CHANCE FOR
LIGHT FREEZING RAIN REMAINS IN THE FORECAST FOR MUCH OF THE AREA FOR
A FEW HOURS SUNDAY MORNING AROUND DAYBREAK...WITH LIGHT RAIN THEN
FORECAST BY 14Z AS SURFACE TEMPERATURE READINGS CLIMB ABOVE FREEZING.
THERE MAY ALSO BE A PERIOD OF LIGHT DRIZZLE OR LIGHT FREEZING
DRIZZLE ACROSS PORTIONS OF THE CWA SUNDAY MORNING...WITH GUIDANCE
SUGGESTING 0-1KM RELATIVE HUMIDITY VALUES NEAR 100% WILL ACCOMPANY 0-
1KM BULK SHEAR VALUES OF 25-30KTS. GIVEN THE POTENTIAL FOR A
SATURATED LOWER TROPOSPHERE AS WELL AS SUFFICIENT TURBULENT
MIXING...OPTED TO KEEP A MENTION OF LIGHT DRIZZLE AND LIGHT FREEZING
DRIZZLE GOING IN THE FORECAST FOR SUNDAY MORNING.
AN OVERALL LACK IN OMEGA SHOULD THEN KEEP US DRY THROUGH MUCH OF THE
REST OF THE LONG-TERM FORECAST PERIOD...ALTHOUGH THERE ARE HINTS OF
AN UPPER TROPOSPHERIC SHORT WAVE PERHAPS BRINGING A ROUND OF LIGHT
PRECIPITATION TO THE REGION ON FRIDAY AND AS A RESULT...WENT WITH A
LOW POP ACROSS PORTIONS OF THE CWA ON FRIDAY.
LITTLE IF ANY CHANGE IN BOUNDARY-LAYER AIR MASS SHOULD PRESENT
SIMILAR TEMPERATURE READINGS FROM DAY TO DAY DURING THE LONG-TERM
FORECAST PERIOD...WITH HIGHS IN THE UPPER 40S TO MID 50S AND LOW IN
THE UPPER 20S TO LOWER 30S CURRENTLY FORECAST FOR THE MOST PART.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1129 PM CST FRI DEC 5 2014
FOR THE MOST PART...QUIET WEATHER IS EXPECTED DURING THE TAF
PERIOD. THAT BEING SAID...THERE IS A CONCERN THAT THE
TERMINALS...KGRI IN PARTICULAR...MAY BE ON THE EDGE OF STRATUS
WORKING WESTWARD AND IF LOW CLOUDS MAKE IT THIS FAR WEST...THEN
FOG MAY OCCUR ON THE EDGE OF THE STRATUS. AGAIN TOWARD THE END OF
THE TAF PERIOD...IN RETURN FLOW...LLVL MOISTURE WILL WORK TO THE
NORTH AND WEST AGAIN AND WILL NEED TO MONITOR FOR LOW CLOUD AND
FOG POTENTIAL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...NOAA/NWS/MORITZ
LONG TERM...BRYANT
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1145 PM CST FRI DEC 5 2014
.SYNOPSIS...
ISSUED AT 322 PM CST FRI DEC 5 2014
WEAK COLD FRONT STALLING NEAR THE KS/NEB BORDER THIS AFTERNOON.
MOSTLY SUNNY SKIES AND SOME 10 TO 15 MPH NORTHERLY WINDS BEHIND THE
FRONT HAVE ALLOWED FOR GOOD MIXING WITH TEMPERATURES IN THE UPPER
40S AND 50S. MEANWHILE HIGH PRESSURE IS SETTLING ACROSS THE NORTHERN
PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
TONIGHT HIGH PRESSURE WILL CONTINUE TO DRIFT ACROSS THE NORTHERN
PLAINS. THIS WILL CAUSE THE WINDS TO BECOME EASTERLY/SOUTHEASTERLY.
THIS WIND SWITCH WILL HELP TO USHER IN SOME LL MOISTURE. THIS WILL
COMBINE WITH MOSTLY CLEAR SKIES AND GOOD RADIATIONAL COOLING TO
PRODUCE LOWS IN THE TEENS AND MAYBE SOME PATCHY FOG. SOME CONCERNS
TOWARDS THE FOG DEVELOPMENT AS AFTERNOON TEMPS IN THE 50S MIXED THE
MOISTURE FAIRLY WELL. ALSO A VERY DRY SURFACE...LITTLE RAIN OVER THE
LAST MONTH ACROSS MOST OF THE AREA. THE NAM IS THE ONLY MODEL
SUGGESTING DEVELOPMENT...ALTHOUGH IT IS A LITTLE HIGH WITH CURRENT
DEW PTS. THE RUC IS LESS FAVORABLE...BUT IS CLOSER BUT IS A DEGREE
OR SO TO LOW WITH DEW PTS. THUS THE FORECAST DOES INCLUDE SOME
PATCHY FOG IN THE PLATTE RIVER VALLEY...WHICH IS LIKELY THE FIRST
PLACE FOR DEVELOPMENT ALTHOUGH CONFIDENCE IS LOW. HAVE ALSO INCLUDED
SOME FOG ACROSS THE FAR NORTHWEST...HOWEVER THERE IS BETTER GROUND
MOISTURE.
TOMORROW COOL HIGH PRESSURE CENTERED OVER MINNESOTA...HOWEVER WILL
SEE SOME COOLER TEMPS ALOFT /850 MB TEMPS AROUND 5C/ INTO THE HIGH
PLAINS. WILL KEEP TEMPS ABOUT 5 TO 10 DEGREES COOLER THAN TODAY.
LATELY THE WARMER MAV HAS BEEN CLOSER TO REALITY AND FAVORED THESE
WARMER NUMBERS FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
...ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS FORECAST SUNDAY
THROUGH FRIDAY...
MID RANGE PERIODS (SATURDAY NIGHT THROUGH MONDAY)...
THE UPPER TROUGH EXITING THE ROCKIES WILL MOVE ACROSS WESTERN
NEBRASKA SATURDAY NIGHT INTO SUNDAY. WHILE MOISTURE WILL BE AMPLE
FROM H7 TO H5...H85 TO H7 RELATIVELY DRY. CONCERN LIES IN
SATURATED LAYER BELOW 875 MB. WITH WEAK OMEGA PRESENT ALONG WITH
SUPERCOOLED DROPLETS OF -1C TO -3C...INTRODUCED PATCHY FREEZING
FRIZZLE WHICH IS POSSIBLE FROM 09Z TO 15Z SUNDAY. SURFACE
TEMPERATURES DURING THIS TIME SHOULD RANGE FROM 28 TO 32 DEGREES.
THE AREA MAY AFFECT SOUTHEASTERN AREAS MAINLY EAST OF A CURTIS
THROUGH CALLAWAY AND STUART LINE. OTHERWISE CLEARING SKIES FROM
WEST TO EAST ON SUNDAY WITH ANOTHER NICE WARMUP. DOWNSLOPING WEST
TO NORTHWEST WINDS 5 TO 15 MPH SHOULD PUSH HIGHS UP INTO THE LOWER
TO MID 50S...EXCEPT COOLER UPPER 40S NEAR ONEILL AND BARTLETT. A
WEAK COLD FRONT SUNDAY NIGHT. HIGHS MONDAY HOWEVER WILL REMAIN
VERY SIMILAR TO SUNDAY.
EXTENDED PERIODS (MONDAY NIGHT THROUGH FRIDAY)...
THE MILD CONDITIONS WILL PERSIST IN THE EXTENDED PERIODS AS UPPER
RIDGING DOMINATES THE CENTRAL CONUS. INCREASED TROUGHING ONTO THE
WEST COAST WILL ALSO HELP TO AMPLIFY DOWNSTREAM RIDGE.
UPPER RIDGING WILL BUILD INTO THE CENTRAL CONUS WEDNESDAY THROUGH
FRIDAY WITH HIGHS IN THE 50S. SOME HIGHS IN THE WEST COULD EXCEED
60 DEGREES WEDNESDAY AND BEYOND. BY FRIDAY...A STRONG UPPER
TROUGH WILL MOVE ONTO THE WEST COAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1145 PM CST FRI DEC 5 2014
EXPECT MAINLY CLEAR SKIES OVERNIGHT ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA. SOME PATCHY FOG IS POSSIBLE IN THE PLATTE RIVER
VALLEY TOWARD MORNING. VISBYS AT THE KLBF TERMINAL MAY DROP DOWN
TO 3SM AROUND 12Z SATURDAY. DURING THE DAY ON SATURDAY...HIGH
CLOUDS WILL BEGIN TO INCREASE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA AS A STORM SYSTEM MOVES INTO THE SOUTHWESTERN UNITED
STATES. BROKEN CIGS AROUND 20000 FT AGL ARE LIKELY AROUND 00Z
SUNDAY...WITH OVERCAST CIGS AROUND 10000 FT AGL EXPECTED FROM 00Z
TO 06Z SUNDAY. WINDS WILL BE FROM THE SOUTH OR SOUTHEAST AT AROUND
10 KTS ON SATURDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...ROBERG
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1251 AM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WILL PASS JUST SOUTH OF THE REGION TONIGHT INTO
SATURDAY WITH MODERATING TEMPERATURES AND WIDESPREAD LIGHT MIXED
PRECIPITATION EXPECTED. COLDER AND DRIER WEATHER RETURNS BEHIND THIS
SYSTEM BY SATURDAY NIGHT AND PERSISTS INTO MONDAY AS CANADIAN HIGH
PRESSURE BRIDGES ACROSS THE NORTHEAST. BY THE MIDDLE OF NEXT
WEEK...THERE IS INCREASING CONFIDENCE THAT A SIGNIFICANT WINTER
STORM MAY AFFECT THE REGION WITH MODERATE TO HEAVY RAIN AND SNOW.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 1233 AM EST SATURDAY...CURRENT FORECAST LOOKS TO BE ON
TRACK WITH ONLY CHANGE BEING TO BLEND IN CURRENT OBSERVATIONS.
LIGHT SNOW HAS BEGUN IN NORTHERN AND CENTRAL VT BUT THE STEADIEST
AREAS OF LIGHT SNOW HAS BEEN ACROSS SOUTHERN VT INTO ESSEX COUNTY
NY. ASSESSMENT OF KENX DUAL-POL DATA AND RAP THERMAL PROGS SUGGEST
MELTING LAYER ROUGHLY EXTENDS FROM NORTHWEST MA UP TO THE NORTH
SIDE OF THE ALBANY METRO THEN EASTWARD ALONG I-90. SO STILL SOME
TIME FOR SNOW TO ACCUMULATE FURTHER BEFORE AFOREMENTIONED WARM
NOSE LIFTS NORTH AND PRECIPITATION BECOMES MORE OF A MIX OF
SNOW...SLEET AND FREEZING RAIN. THIS IS ALREADY CAPTURED WELL IN
GOING FORECAST SO NO CHANGES TO THE WINTER WEATHER ADVISORY AT
THIS TIME.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 1020 PM EST FRIDAY
FOLLOWS...
LIGHT PRECIPITATION IS RATHER WIDESPREAD ACROSS VERMONT THIS
EVENING. PRECIPITATION IS MOSTLY IN THE FORM OF SNOW...WITH A FEW
POCKETS OF FREEZING RAIN/FREEZING DRIZZLE. ACROSS NORTHERN NEW
YORK...SPOTTY COVERAGE OF PRECIPITATION WITH SOME AREAS OF LIGHT
SNOW OR MIXED PRECIPITATION. NO SIGNIFICANT CHANGES TO GOING
FORECAST...JUST A FEW ADJUSTMENTS TO POPS AND WEATHER OVER NEXT
FEW HOURS TO REFLECT LATEST CONDITIONS AND TRENDS. THERMAL
PROFILES STILL INDICATE LIGHT SNOW TURNS TO A WINTRY MIX
OVERNIGHT...AND TO RAIN IN SOME AREAS. HIGHEST POPS FOR THE
OVERNIGHT PERIOD ACROSS CENTRAL AND SOUTHERN SECTIONS OF VERMONT
WITH LOWEST POPS ACROSS SAINT LAWRENCE VALLEY. GOING FORECAST HAS
ALL OF THIS WELL COVERED. ALSO...NO CHANGES TO WINTER WEATHER
ADVISORIES WHICH ARE IN EFFECT FOR MUCH OF VERMONT OUTSIDE OF
CHAMPLAIN VALLEY AND PART OF ESSEX COUNTY NY. LOOK FOR A FEW
INCHES OF SNOW WITH LIGHT ICE ACCUMULATION.
EARLIER DISCUSSION...
FORECAST REMAINS MORE OR LESS ON TRACK FOR TONIGHT AS CLOUDS
CONTINUE TO THICKEN AND LOWER AS DEEP WARM THERMAL ADVECTION
OVERSPREADS THE REGION FROM THE SOUTH AND WEST. PRECIPITATION SEEN
ON RADAR LATE THIS AFTERNOON ACROSS EASTERN PORTIONS OF NY STATE
IS MAINLY IN VIRGA FORM...BUT STEADIER LIGHT PRECIPITATION STILL
ON TRACK TO ARRIVE LATER THIS EVENING/TONIGHT AS LEAD SURFACE WAVE
TRACKS ENE FROM THE OHIO VALLEY. LEANED TOWARD GFS THERMAL
PROFILES AS NAM SHOWING ITS TYPICAL COLDER BIAS ALOFT. LATEST CAM
TRENDS ALSO SUGGEST BULK OF STEADIER PRECIPITATION TO AFFECT AREAS
GENERALLY ALONG AND SOUTH OF A KART- KSLK-KBTV-K1V4 LINE LATER
TONIGHT WITH FAR NORTHERN COUNTIES SEEING ONLY SCT LIGHT
PRECIPITATION AT BEST. THAT SAID...I`M STILL EXPECTING A PERIOD OF
SHSN/LIGHT SNOWS TO OVERSPREAD A GOOD PORTION OF THE AREA LATER
THIS EVENING/TONIGHT BEFORE PRECIPITATION TRANSITIONS TO A MIX OF
PL/FZRA...ESP ACROSS EASTERN PORTIONS OF VT SOUTH OF ROUTE 2 OR
SO. ELSEWHERE...ESP IN THE CHAMPLAIN VALLEY AND ADIRONDACKS...MIX
WITH PL/FZRA SHOULD BE RELATIVELY BRIEF BEFORE TRANSITION TO LIGHT
RAIN GIVEN SOUTHERLY FLOW WILL CONTINUE TO WARM THE NEAR SFC
LAYERS. THUS MORE MINIMAL IMPACTS IN THESE LOCATIONS DESPITE ROADS
POSSIBLY BEING A LITTLE SLICK BY MORNING. TEMPERATURES TO REMAIN
STEADY OR SLOWLY RISE OVERNIGHT...MOST PRONOUNCED FROM THE WESTERN
SLOPES WEST ACROSS THE CHAMPLAIN VALLEY INTO OUR NRN NY COUNTIES.
SNOWFALL AMOUNTS BY SATURDAY MORNING GENERALLY A DUSTING TO 2
INCHES CHAMPLAIN VALLEY...A GOOD PORTION OF THE NRN ADIRONDACKS
AND SAINT LAWRENCE VALLEY. IN CURRENT WINTER WEATHER ADVISORY
AREA...1-3 INCHES OF SNOW EXPECTED ACROSS THE HIGH PEAKS REGION
AND MUCH OF VERMONT EAST OF THE GREENS WHERE THERMAL PROFILES WILL
BE SLIGHTLY COLDER. LOCALIZED HIGHER AMOUNTS...2-4 INCHES OR SO
POSSIBLE ACROSS PORTIONS OF NC/NE VT. AGAIN...SOME LIGHT TO TRACE
AMOUNTS OF ICE WILL ALSO BE POSSIBLE IN THESE AREAS
&&
.SHORT TERM /7 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 326 PM EST FRIDAY...BY TOMORROW WIDESPREAD LIGHT TO
MODERATE PRECIPITATION CONTINUES AS SECONDARY AND MORE ROBUST SFC
WAVE RIDES ACROSS THE NORTHERN MID-ATLANTIC INTO SOUTHERN NEW
ENGLAND. THERMAL PROFILES CONTINUE TO SLOWLY WARM SUCH THAT MOST
AREAS EXCEPT THE FAR NORTH/NORTHWEST SHOULD FULLY TRANSITION TO
LIGHT RAIN BY MID TO LATE MORNING WITH PERHAPS A FEW POCKETS OF
LIGHT FZRA LINGERING ACROSS SHELTERED ERN VT HOLLOWS THROUGH NOON
OR SO. MODELS FAIRLY CONSISTENT IN SHOWING A RATHER SHARP CUTOFF
IN STEADIER PRECIPITATION NORTH AND WEST OF A KSLK-KBTV-KNPT LINE
TOMORROW. SO AREAS ACROSS FAR NW VT INTO FAR NRN NY/SAINT LAWRENCE
VALLEY STEADIER PRECIPITATION LESS LIKELY.
BY LATER IN THE AFTERNOON INTO EARLY EVENING THE APPROACH OF A
MODESTLY STRONG NORTHERN STREAM UPPER TROUGH WILL PUSH A COLD FRONT
THROUGH THE REGION WITH STEADIER PRECIPITATION EXITING SOUTH AND
EAST OVER TIME. AS POST-FRONTAL FLOW TRENDS
NORTH/NORTHWESTERLY...PRECIPITATION SHOULD TRANSITION BACK TO A
PERIOD OF LIGHT SNOW/SHSN FOR A FEW HOURS BEFORE ENDING AS DRIER
AIR FILTERS INTO THE REGION. THUS AN ADDITIONAL BACKSIDE D-2"
SNOWFALL WILL BE POSSIBLE IN THE 21-03Z TIME FRAME.
THEREAFTER...COLD FRONT EXITS SOUTHEAST OVERNIGHT SATURDAY AS
ANOMALOUSLY STRONG 1045 MB CANADIAN POLAR HIGH BUILDS ACROSS THE
REGION BY SUNDAY/SUNDAY NIGHT ON DIMINISHING NORTHWESTERLY FLOW.
THUS THE IDEA OF GRADUAL CLEARING FROM NORTHWEST TO SOUTHEAST
SATURDAY EVENING LOOKS ON TRACK AS TEMPERATURES TREND BACK TOWARD
SEASONALLY COLD VALUES. INDEED...AS HIGH CRESTS ATOP THE REGION
SUNDAY NIGHT WIDESPREAD VALUES IN THE SINGLE DIGITS ABOVE/BELOW ZERO
LOOK QUITE REALISTIC AS LIGHT WINDS/CLEAR SKIES LEAD TO OPTIMAL
LONGWAVE RADIATIVE PROCESSES.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 326 PM EST FRIDAY...DRY WEATHER IS EXPECTED THROUGH MONDAY
NIGHT AS A DOME OF HIGH PRESSURE CONTINUES BUILDING INTO THE AREA.
BY TUESDAY MORNING THE UPPER LEVEL TROUGH WILL DIG INTO THE GREAT
LAKES AND PUSH THE HIGH PRESSURE WELL OFF TO THE NORTHEAST OVER
NEWFOUNDLAND OPENING THE REGION UP FOR A EITHER A COASTAL LOW OR A
SHORTWAVE WITH THE UPPER LEVEL TROUGH DEPENDING ON THE MODEL TO
PUSH INTO THE REGION. RIGHT NOW THE GFS IS THE LONE LONG RANGE
MODEL WITH THE SHORT WAVE SOLUTION. THE ECMWF IS MUCH MORE ALIGNED
WITH THE UKMET, CANADIAN AND DGEX IN BRINGING IN A COASTAL LOW UP
THE EAST COAST THEN PHASING JUST OFF THE COAST OF NEW JERSEY. AS
THE PHASING OCCURS THERE IS AN INCREASING CHANCE OF RAIN/SNOW
SHOWER ON WEDNESDAY. THE OCCLUDED LOW REDEVELOPS JUST OFF OF CAPE
COD WHICH COULD BRING THE PORTIONS OF THE AREA HEAVY SNOWFALL AS
THE WINDS SHIFT AROUND AND DEVELOP A MORE NORTHERLY COMPONENT.
WITH HIGH PRESSURE TO THE NORTHWEST NEAR LAKE SUPERIOR A STRONG
PRESSURE GRADIENT WILL BRING STRONG NORTHEASTERLY WINDS ON
WEDNESDAY SHIFTING TO NORTHERLY BY THURSDAY. RIGHT NOW THE
FORECAST IS A BLEND OF THE MODELS WITH LIKELY RAIN/SNOW SHOWERS ON
TUESDAY WITH A CHANCE OF SNOW SHOWERS ON THURSDAY AS WE GET HIT BY
THE BACK SIDE OF THE LOW. MAX TEMPS WILL BE FOR THE MOST PART NEAR
NORMAL WITH MIN TEMPS RUNNING A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...MVFR/VFR CEILINGS AND VISIBILITIES WILL
CONTINUE EARLY THIS MORNING AS FIRST AREA OF PRECIPITATION MOVES
ACROSS THE AREA. THE PRECIPITATION WILL GENERALLY BE LIGHT...BUT
WILL BE A MIX OF SNOW...SLEET...AND FREEZING DRIZZLE. THE
PRECIPITATION SHOULD END BY 12Z...THEN A SECONDARY AREA OF
PRECIPITATION WILL MOVE UP FROM THE OHIO VALLEY AND BE IN THE FORM
OF RAIN AND SOME SNOW FROM MID-MORNING THROUGH EARLY EVENING. IT
WILL BE DURING THIS PERIOD THAT CEILINGS AND VISIBILITIES WILL
LOWER INTO THE MVFR AND IFR CATEGORIES. THE WINDS WILL BECOME
NORTHWEST BETWEEN 18Z AND 20Z AND THE PRECIPITATION WILL GRADUALLY
COME TO AN END BETWEEN 20Z AND 02Z. VISIBILITIES WILL IMPROVE INTO
THE VFR CATEGORY AT THIS TIME...BUT CEILINGS WILL REMAIN MVFR/IFR
FOR THE REMAINDER OF THE PERIOD.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUN - 12Z TUES: VFR...THOUGH A CHANCE OF MVFR DEVELOPING
DURING THE DAY MONDAY.
12Z TUES - 00Z THURS: MVFR EXPECTED WITH PERIODS OF IFR AS A
SYSTEM DEVELOPS AND BRINGS PERIODS OF PRECIPITATION.
&&
.MARINE...
A LAKE WIND ADVISORY IS IN EFFECT FOR TONIGHT. LOW LEVEL SOUTHERLY
JET OVER THE REGION OVERNIGHT...SO EXPECT SOUTH WINDS 15 TO 25
KTS. WAVE HEIGHTS WILL RANGE FROM 2 TO 4 FEET ON THE BROAD LAKE.
WINDS ARE EXPECTED TO DROP BELOW ADVISORY CRITERIA SATURDAY
MORNING AND THEN SHIFT INTO THE NORTH SATURDAY AFTERNOON WITH THE
PASSAGE OF A COLD FRONT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ003-
004-006>008-010>012-016>019.
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ034.
&&
$$
SYNOPSIS...JMG
NEAR TERM...RJS/LOCONTO
SHORT TERM...JMG
LONG TERM...DEAL
AVIATION...EVENSON/DEAL
MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1234 AM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WILL PASS JUST SOUTH OF THE REGION TONIGHT INTO
SATURDAY WITH MODERATING TEMPERATURES AND WIDESPREAD LIGHT MIXED
PRECIPITATION EXPECTED. COLDER AND DRIER WEATHER RETURNS BEHIND THIS
SYSTEM BY SATURDAY NIGHT AND PERSISTS INTO MONDAY AS CANADIAN HIGH
PRESSURE BRIDGES ACROSS THE NORTHEAST. BY THE MIDDLE OF NEXT
WEEK...THERE IS INCREASING CONFIDENCE THAT A SIGNIFICANT WINTER
STORM MAY AFFECT THE REGION WITH MODERATE TO HEAVY RAIN AND SNOW.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 1233 AM EST SATURDAY...CURRENT FORECAST LOOKS TO BE ON
TRACK WITH ONLY CHANGE BEING TO BLEND IN CURRENT OBSERVATIONS.
LIGHT SNOW HAS BEGUN IN NORTHERN AND CENTRAL VT BUT THE STEADIEST
AREAS OF LIGHT SNOW HAS BEEN ACROSS SOUTHERN VT INTO ESSEX COUNTY
NY. ASSESSMENT OF KENX DUAL-POL DATA AND RAP THERMAL PROGS SUGGEST
MELTING LAYER ROUGHLY EXTENDS FROM NORTHWEST MA UP TO THE NORTH
SIDE OF THE ALBANY METRO THEN EASTWARD ALONG I-90. SO STILL SOME
TIME FOR SNOW TO ACCUMULATE FURTHER BEFORE AFOREMENTIONED WARM
NOSE LIFTS NORTH AND PRECIPITATION BECOMES MORE OF A MIX OF
SNOW...SLEET AND FREEZING RAIN. THIS IS ALREADY CAPTURED WELL IN
GOING FORECAST SO NO CHANGES TO THE WINTER WEATHER ADVISORY AT
THIS TIME.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 1020 PM EST FRIDAY
FOLLOWS...
LIGHT PRECIPITATION IS RATHER WIDESPREAD ACROSS VERMONT THIS
EVENING. PRECIP IS MOSTLY IN THE FORM OF SNOW...WITH A FEW POCKETS
OF FREEZING RAIN/FREEZING DRIZZLE. ACROSS NORTHERN NEW
YORK...SPOTTY COVERAGE OF PRECIPITATION WITH SOME AREAS OF LIGHT
SNOW OR MIXED PRECIP. NO SIGNIFICANT CHANGES TO GOING
FORECAST...JUST A FEW ADJUSTMENTS TO POPS AND WX OVER NEXT FEW
HOURS TO REFLECT LATEST CONDITIONS AND TRENDS. THERMAL PROFILES
STILL INDICATE LIGHT SNOW TURNS TO A WINTRY MIX OVERNIGHT...AND TO
RAIN IN SOME AREAS. HIGHEST POPS FOR THE OVERNIGHT PERIOD ACROSS
CENTRAL AND SOUTHERN SECTIONS OF VERMONT WITH LOWEST POPS ACROSS
SAINT LAWRENCE VALLEY. GOING FORECAST HAS ALL OF THIS WELL
COVERED. ALSO...NO CHANGES TO WINTER WEATHER ADVISORIES WHICH ARE
IN EFFECT FOR MUCH OF VERMONT OUTSIDE OF CHAMPLAIN VALLEY AND PART
OF ESSEX COUNTY NY. LOOK FOR A FEW INCHES OF SNOW WITH LIGHT ICE
ACCUMULATION.
EARLIER DISCUSSION...
FORECAST REMAINS MORE OR LESS ON TRACK FOR TONIGHT AS CLOUDS
CONTINUE TO THICKEN AND LOWER AS DEEP WARM THERMAL ADVECTION
OVERSPREADS THE REGION FROM THE SOUTH AND WEST. PRECIPITATION SEEN
ON RADAR LATE THIS AFTERNOON ACROSS EASTERN PORTIONS OF NY STATE
IS MAINLY IN VIRGA FORM...BUT STEADIER LIGHT PCPN STILL ON TRACK
TO ARRIVE LATER THIS EVENING/TONIGHT AS LEAD SURFACE WAVE TRACKS
ENE FROM THE OHIO VALLEY. LEANED TOWARD GFS THERMAL PROFILES AS
NAM SHOWING ITS TYPICAL COLDER BIAS ALOFT. LATEST CAM TRENDS ALSO
SUGGEST BULK OF STEADIER PCPN TO AFFECT AREAS GENERALLY ALONG AND
SOUTH OF A KART- KSLK-KBTV-K1V4 LINE LATER TONIGHT WITH FAR
NORTHERN COUNTIES SEEING ONLY SCT LIGHT PCPN AT BEST. THAT
SAID...I`M STILL EXPECTING A PERIOD OF SHSN/LIGHT SNOWS TO
OVERSPREAD A GOOD PORTION OF THE AREA LATER THIS EVENING/TONIGHT
BEFORE PCPN TRANSITIONS TO A MIX OF PL/FZRA...ESP ACROSS EASTERN
PORTIONS OF VT SOUTH OF ROUTE 2 OR SO. ELSEWHERE...ESP IN THE
CHAMPLAIN VALLEY AND DACKS...MIX WITH PL/FZRA SHOULD BE RELATIVELY
BRIEF BEFORE TRANSITION TO LIGHT RAIN GIVEN SOUTHERLY FLOW WILL
CONTINUE TO WARM THE NEAR SFC LAYERS. THUS MORE MINIMAL IMPACTS IN
THESE LOCATIONS DESPITE ROADS POSSIBLY BEING A LITTLE SLICK BY
MORNING. TEMPERATURES TO REMAIN STEADY OR SLOWLY RISE
OVERNIGHT...MOST PRONOUNCED FROM THE WESTERN SLOPES WEST ACROSS
THE CHAMPLAIN VALLEY INTO OUR NRN NY COUNTIES. SNOWFALL AMOUNTS BY
SATURDAY MORNING GENERALLY A DUSTING TO 2 INCHES CHAMPLAIN
VALLEY...A GOOD PORTION OF THE NRN DACKS AND SLV. IN CURRENT
WINTER WX ADVISORY AREA...1-3 INCHES OF SNOW EXPECTED ACROSS THE
HIGH PEAKS REGION AND MUCH OF VERMONT EAST OF THE GREENS WHERE
THERMAL PROFILES WILL BE SLIGHTLY COLDER. LOCALIZED HIGHER
AMOUNTS...2-4 INCHES OR SO POSSIBLE ACROSS PORTIONS OF NC/NE VT.
AGAIN...SOME LIGHT TO TRACE AMOUNTS OF ICE WILL ALSO BE POSSIBLE
IN THESE AREAS
&&
.SHORT TERM /7 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 326 PM EST FRIDAY...BY TOMORROW WIDESPREAD LIGHT TO
MODERATE PRECIPITATION CONTINUES AS SECONDARY AND MORE ROBUST SFC
WAVE RIDES ACROSS THE NORTHERN MID-ATLANTIC INTO SOUTHERN NEW
ENGLAND. THERMAL PROFILES CONTINUE TO SLOWLY WARM SUCH THAT MOST
AREAS EXCEPT THE FAR NORTH/NORTHWEST SHOULD FULLY TRANSITION TO
LIGHT RAIN BY MID TO LATE MORNING WITH PERHAPS A FEW POCKETS OF
LIGHT FZRA LINGERING ACROSS SHELTERED ERN VT HOLLOWS THROUGH NOON
OR SO. MODELS FAIRLY CONSISTENT IN SHOWING A RATHER SHARP CUTOFF
IN STEADIER PCPN NORTH AND WEST OF A KSLK-KBTV-KNPT LINE TOMORROW.
SO AREAS ACROSS FAR NW VT INTO FAR NRN NY/SLV STEADIER PCPN LESS
LIKELY.
BY LATER IN THE AFTERNOON INTO EARLY EVENING THE APPROACH OF A
MODESTLY STRONG NORTHERN STREAM UPPER TROUGH WILL PUSH A COLD FRONT
THROUGH THE REGION WITH STEADIER PCPN EXITING SOUTH AND EAST OVER
TIME. AS POST-FRONTAL FLOW TRENDS NORTH/NORTHWESTERLY...PCPN SHOULD
TRANSITION BACK TO A PERIOD OF LIGHT SNOW/SHSN FOR A FEW HOURS
BEFORE ENDING AS DRIER AIR FILTERS INTO THE REGION. THUS AN
ADDITIONAL BACKSIDE D-2" SNOWFALL WILL BE POSSIBLE IN THE 21-03Z
TIME FRAME.
THEREAFTER...COLD FRONT EXITS SOUTHEAST OVERNIGHT SATURDAY AS
ANOMALOUSLY STRONG 1045 MB CANADIAN POLAR HIGH BUILDS ACROSS THE
REGION BY SUNDAY/SUNDAY NIGHT ON DIMINISHING NORTHWESTERLY FLOW.
THUS THE IDEA OF GRADUAL CLEARING FROM NORTHWEST TO SOUTHEAST
SATURDAY EVENING LOOKS ON TRACK AS TEMPERATURES TREND BACK TOWARD
SEASONALLY COLD VALUES. INDEED...AS HIGH CRESTS ATOP THE REGION
SUNDAY NIGHT WIDESPREAD VALUES IN THE SINGLE DIGITS ABOVE/BELOW ZERO
LOOK QUITE REALISTIC AS LIGHT WINDS/CLR SKIES LEAD TO OPTIMAL
LONGWAVE RADIATIVE PROCESSES.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 326 PM EST FRIDAY...DRY WEATHER IS EXPECTED THROUGH MONDAY
NIGHT AS A DOME OF HIGH PRESSURE CONTINUES BUILDING INTO THE AREA.
BY TUESDAY MORNING THE UPPER LEVEL TROUGH WILL DIG INTO THE GREAT
LAKES AND PUSH THE HIGH PRESSURE WELL OFF TO THE NORTHEAST OVER
NEWFOUNDLAND OPENING THE REGION UP FOR A EITHER A COASTAL LOW OR A
SHORTWAVE WITH THE UPPER LEVEL TROUGH DEPENDING ON THE MODEL TO
PUSH INTO THE REGION. RIGHT NOW THE GFS IS THE LONE LONG RANGE
MODEL WITH THE SHORT WAVE SOLUTION. THE ECMWF IS MUCH MORE ALIGNED
WITH THE UKMET, CANADIAN AND DGEX IN BRINGING IN A COASTAL LOW UP
THE EAST COAST THEN PHASING JUST OFF THE COAST OF NEW JERSEY. AS
THE PHASING OCCURS THERE IS AN INCREASING CHANCE OF RAIN/SNOW
SHOWER ON WEDNESDAY. THE OCCLUDED LOW REDEVELOPS JUST OFF OF CAPE
COD WHICH COULD BRING THE PORTIONS OF THE AREA HEAVY SNOWFALL AS
THE WINDS SHIFT AROUND AND DEVELOP A MORE NORTHERLY COMPONENT.
WITH HIGH PRESSURE TO THE NORTHWEST NEAR LAKE SUPERIOR A STRONG
PRESSURE GRADIENT WILL BRING STRONG NORTHEASTERLY WINDS ON
WEDNESDAY SHIFTING TO NORTHERLY BY THURSDAY. RIGHT NOW THE
FORECAST IS A BLEND OF THE MODELS WITH LIKELY RAIN/SNOW SHOWERS ON
TUESDAY WITH A CHANCE OF SNOW SHOWERS ON THURSDAY AS WE GET HIT BY
THE BACK SIDE OF THE LOW. MAX TEMPS WILL BE FOR THE MOST PART NEAR
NORMAL WITH MIN TEMPS RUNNING A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...A GENERAL DETERIORATION OF FLIGHT CONDITIONS
IS EXPECTED OVER THE NEXT 24 HOURS. ALL SITES START VFR THIS
EVENING WITH A FEW BRIEF REDUCTIONS TO MVFR IN LIGHT SNOW
SHOWERS/FLURRIES FOR THE FIRST COUPLE OF HOURS.
AFTERWARD...CEILINGS WILL LOWER TO MVFR AREA-WIDE AND AREAS OF
LIGHT MIXED PRECIPITATION WILL CONTINUE TO DEVELOP AND BRING
PERIODS OF REDUCED VISIBILITIES (MAINLY TO MVFR ALTHOUGH SOME IFR
POSSIBLE AT SLK). MOST SITES WILL CHANGE TO RAIN LATE
TONIGHT/EARLY SATURDAY MORNING. SOUTHERLY FLOW TONIGHT (EXCEPT
NORTHEAST AT MSS) WILL TURN NORTH/NORTHWESTERLY BY SATURDAY
AFTERNOON USHERING IN AN ADDITIONAL LOWERING OF CEILINGS AND A
CHANGE BACK OVER TO SNOW...THUS EXPECTING WIDESPREAD MVFR/IFR BY
LATE SATURDAY.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...
00Z SUN - 06Z SUN: MVFR/IFR IN LIGHT SNOW...GRADUALLY ENDING FROM
WEST TO EAST.
06Z SUN - 12Z TUES: VFR...THOUGH A CHANCE OF MVFR DEVELOPING
DURING THE DAY MONDAY.
12Z TUES - 00Z THURS: MVFR EXPECTED WITH PERIODS OF IFR AS A
SYSTEM DEVELOPS AND BRINGS PERIODS OF PRECIPITATION.
&&
.MARINE...
A LAKE WIND ADVISORY IS IN EFFECT FOR TONIGHT. LOW LEVEL SOUTHERLY
JET OVER THE REGION OVERNIGHT...SO EXPECT SOUTH WINDS 15 TO 25
KTS. WAVE HEIGHTS WILL RANGE FROM 2 TO 4 FEET ON THE BROAD LAKE.
WINDS ARE EXPECTED TO DROP BELOW ADVISORY CRITERIA SATURDAY
MORNING AND THEN SHIFT INTO THE NORTH SATURDAY AFTERNOON WITH THE
PASSAGE OF A COLD FRONT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ003-
004-006>008-010>012-016>019.
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ034.
&&
$$
SYNOPSIS...JMG
NEAR TERM...RJS/LOCONTO
SHORT TERM...JMG
LONG TERM...DEAL
AVIATION...DEAL/MUCCILLI
MARINE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
425 AM EST SAT DEC 6 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE CAROLINAS BRINGING SHOWERS TODAY AND
ISOLATED THUNDERSTORMS TONIGHT BEFORE REACHING OFF SHORE OVERNIGHT. A
STRONG WEDGE OF HIGH PRESSURE WILL BUILD SOUTH SUNDAY AND
MONDAY...BRINGING GUSTY NORTH WINDS AND MUCH COOLER TEMPERATURES.
CANADIAN HIGH PRESSURE NEXT WEEK WILL MAINTAIN SEASONABLY COOL
TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 4 AM SATURDAY...SURFACE LOW PRECEDING AN UPPER TROUGH WAS
APPROACHING THE CENTRAL APPALACHIANS...HELPING TO LIFT A COASTAL
TROUGH ONTO THE CAROLINA COAST EARLY THIS MORNING. KLTX SENSING
MODERATE CONVECTION OFFSHORE OF CAPE FEAR MOVING NORTH TOWARD SURF
CITY TO CARTERET COUNTY TO CAPE LOOKOUT. ORGANIZED PRECIPITATION
WAS ADVANCING INTO THE WESTERN CAROLINAS. THE TRENDING WEATHER
FEATURES OCEAN CONVECTION MOVING N AND NE OF NE SC/SE NC THROUGH
MORNING WHILE A BROADER SHIELD OF -RA ENCROACHES FROM THE WEST.
A COLD FRONT WILL SWEEP OFF THE COAST LATE THIS EVENING. AHEAD OF
THE FRONT DESTABILIZATION MAY STRENGTHEN IN THE AFTERNOON IF CLOUD
BREAKS ALLOW SURFACE WARMING...OTHERWISE BEST MIXED LAYER CAPES
SPIKE AS DOES OMEGA AND COLUMN MOISTURE OVER THE AREA BETWEEN
00Z-04Z. LOW-LEVELS WIND DO NOT APPEAR TO SUPPORT A SEVERE THREAT
AHEAD OF THE FRONT BUT WILL MAINTAIN ISOLATED TSTM MENTION.
MAXIMUM TEMPERATURES WILL NOT BE EASY SINCE BREAKS IN THE CLOUDS
COULD WARM LOCAL TEMPS QUICKLY IN THE GROWING WARM SECTOR. BREAKS
HOWEVER SHOULD NOT LAST LONG WITH PLENTIFUL UPSTREAM CLOUDS NOTED
CURRENTLY...UPPER 60S TO LOWER 70S MOST PLACES AND A LITTLE COOLER
BY THE SEA. COLD AIR ADVECTION ALREADY UNDERWAY PRIOR TO DAYBREAK
IN BRISK AND DEEP NORTH WIND FLOW...AND GUSTY. MINIMUMS BY FIRST
LIGHT SUNDAY IN THE 40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STRONG HIGH PRESSURE WILL BUILD DOWN
ACROSS THE CAROLINAS ON SUNDAY. A 1045 MB HIGH WILL MOVE ACROSS
CANADA FROM JUST NORTH OF THE GREAT LAKES TO THE CANADIAN
MARITIMES BY MONDAY. TIGHTENED GRADIENT FLOW WILL EXIST BETWEEN
THIS AREA OF HIGH PRESSURE AND LOW PRESSURE LINGERING OVER THE
DISTANT OFF SHORE WATERS OF THE CAROLINAS. EXPECT GUSTY NORTHERLY
WINDS WINDS THROUGH MUCH OF THE PERIOD. SHOULD SEE SOME CLEARING
OUT ON SUNDAY IN DRY NORTHERLY FLOW ESPECIALLY THROUGH INLAND
AREAS ALTHOUGH STRONG INVERSION COULD LOCK IN A DECENT LAYER OF
MOISTURE UNDERNEATH. CAA WILL BRING 850 TEMPS DOWN SEVERAL DEGREES
THROUGH SUNDAY INTO EARLY MONDAY. COASTAL AREAS MAY BE THE LAST
PLACE TO SEE SOME SUNSHINE ON SUNDAY AFTN. PCP WATER VALUES DROP
DOWN NEAR A QUARTER OF AN INCH INLAND WEST OF I95 BUT CLOSE TO THE
COAST VALUES REMAIN AROUND A HALF INCH UNTIL LATER ON SUNDAY.
OVERALL EXPECT TO SEE SOME SUNSHINE BY SUNDAY AFTERNOON WITH TEMPS
IN THE 50S.
MID TO UPPER TROUGH WILL DIG DOWN FROM THE GREAT LAKES ON MONDAY
PUSHING NEXT NORTHERN STREAM SYSTEM EAST. THIS WILL PUSH THE HIGH
PRESSURE OFF THE COAST OF THE CANADIAN MARITIMES LEAVING A WEDGE
OF HIGH PRESSURE DOWN THROUGH THE INLAND CAROLINAS. AT THE SAME
TIME LOW PRESSURE OFF SHORE WILL RETROGRADE BACK WEST TOWARD THE
CAROLINA COAST BEFORE LIFTING OFF TO THE NORTH MON NIGHT. THE LOW
LEVEL INVERSION WILL STRENGTHEN FURTHER AS WARMER AND MOISTER FLOW
DEVELOPS IN THE LOW LEVELS. EXPECT LOW CLOUDS AND CONTINUED COOL
CONDITIONS WITH GUSTY NORTHERLY WINDS AND TEMPS IN THE 50S ONCE
AGAIN. MOST PCP SHOULD REMAIN OFF THE COAST BUT MAY SEE SOME WORK
ITS WAY INLAND THROUGH THE DAY AS LOW MOVES UP ALONG THE CAROLINA
COAST TOWARD VA. BY MON NIGHT DIGGING MID TO UPPER TROUGH WILL
PUSH COLD FRONT EAST WHILE LOW PRESSURE LIFTS OFF TO THE NORTH.
THIS WILL SQUEEZE OUT ANY REMAINING WEDGE BY EARLY TUES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...DEEP MID TO UPPER TROUGH WILL PUSH
NORTHERN STREAM SYSTEM EAST AS LOW PRESSURE SYSTEM LIFTS NORTHEAST
AWAY FROM THE CAROLINAS UP ALONG THE EASTERN SEABOARD. ONCE THIS
SYSTEM SHIFTS OFF SHORE BY LATE TUES IT WILL DRY OUT THE COLUMN
IN DEEP NW FLOW. ALL THE RESIDUAL LOW LEVEL MOISTURE WILL DIMINISH
WITH DEEP DRY COLUMN IN PLACE BY WED THROUGH FRI. OVERALL EXPECT
CLEARING SKIES ON TUES WITH STRONG DRY HIGH PRESSURE BUILDING IN.
A REINFORCING SHOT OF COLD AIR WITH 850 TEMPS DROPPING DOWN BELOW
0C WILL KEEP COOL TEMPS THROUGH MID WEEK. EXPECT HIGHS IN THE 50S
MOST DAYS WITH WED BEING THE COOLEST DAY. SHOULD SEE PLENTY OF
SUNSHINE WED AND THURS.
HIGH PRESSURE WILL MOVE CLOSER OVERHEAD BY THURS INTO FRI WITH
WEAK GRADIENT MAINTAINING LIGHT WINDS ALLOWING AIR MASS TO MODIFY
AND BECOME SLIGHTLY WARMER. A SHORTWAVE IN THE MID LEVELS WILL PASS
THROUGH THURS NIGHT INTO FRI WHICH SHOULD GIVE US SOME PASSING HIGHER
CLOUDS. WILL KEEP POPS OUT OF FORECAST FOR NOW.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE ON THE BACK END OF THE FORECAST
PERIOD WITH RESPECT TO CEILINGS AND THE TIMING OF PRECIP. LOOKS LIKE
THERE COULD BE TWO BATCHES OF RAIN/SHOWERS: THE FIRST AROUND SUNRISE
WITH A COASTAL TROUGH...THEN ANOTHER ROUND IN THE LATE AFTERNOON
AHEAD OF A COLD FRONT. MODELS ARE IN REASONABLE AGREEMENT
INTRODUCING IFR STRATUS/FOG AROUND DAYBREAK IF NOT BEFORE...AND THIS
MAKES SENSE GIVEN THE WEAK WARM AIR ADVECTION. THE HRRR MODEL THINKS
THAT ILM STANDS THE BEST CHANCE FOR MORNING PRECIP...BUT THE MYRTLES
COULD ALSO GET INTO THE ACT. THINK THE MORNING PRECIP WILL GIVE WAY
TO MVFR CEILINGS AND SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT WHICH
WILL ARRIVE AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...PERIODS OF MVFR/IFR CIGS ARE LIKELY THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK. GUSTY NORTH WINDS SUN/MON BEHIND
THE COLD FRONT. BECOMING VFR DURING TUE. VFR WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 4 AM SATURDAY...WINDS AHEAD OF A COLD FRONT WILL REMAIN
RELATIVELY LIGHT TODAY...INCREASING MORE SHARPLY INTO EARLY SUNDAY
AS COLD AIR SPILLS ACROSS THE WATERS. ADVISORY SC WATERS AND GALE
WATCH NC TO BEGINS 11Z SUNDAY WITH THIS ISSUANCE. PRESENTLY NNE
WIND 10 KT AT MASONBORO BUOY AND SE 15G17KT FRYING PAN ILLUSTRATES
WELL THE COASTAL TROUGH BOUNDARY. WILL HAVE TO WATCH FOR ADVISORY
CONDITIONS EARLIER THAN PLANNED SINCE 41013 ALREADY APPROACHING 6
FT. ISOLATED TSTMS POSSIBLE TONIGHT ON THE 0-20 NM WATERS JUST
AHEAD OF THE COLD FRONT. BY DAYBREAK SUNDAY EXPECT 30 KT GUSTS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...GALE WATCH REMAINS IN EFFECT FOR THE NC
WATERS BEGINNING SUNDAY MORNING WITH A SMALL CRAFT ADVISORY OVER
SOUTH CAROLINA WATERS AS WINDS INCREASE THROUGH SUN INTO SUN NIGHT
20 TO 30 KTS WITH FREQUENT GUSTS TO 35 KTS OR GREATER AS STRONG
HIGH PRESSURE BUILDS DOWN INTO THE CAROLINAS. THIS TIGHTENED
GRADIENT FLOW WILL CONTINUE INTO MONDAY AS WEDGE STRENGTHENS DOWN
THROUGH INLAND CAROLINAS WHILE LOW PRESSURE LINGERS AND SHIFTS
CLOSER TO THE COAST BEFORE LIFTING OFF TO THE NORTH BY EARLY TUES.
THIS WILL MAINTAIN STRONG NORTHERLY WINDS AND HIGH SEAS. SEAS WILL
RAMP UP SUN MORNING ABOVE SCA THRESHOLDS AND PEAKING CLOSE TO 10
FT IN OUTER WATERS OVERNIGHT SUN INTO EARLY MON MORNING. OVERALL
SEAS WILL INCREASE UP TO 6 TO 10 FT SUN NIGHT SUBSIDING THROUGH
MON NIGHT AS WINDS BEGIN TO DIMINISH DOWN TO 10 TO 20 KTS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE WILL BUILD DOWN FROM THE
NORTHWEST THROUGH MID WEEK. THE WINDS WILL DIMINISH THROUGH TUES
INTO WED BUT DECENT COLD SURGE COULD KICK WINDS BACK UP TUES NIGHT
TO 15 TO 20 KTS AND OUTER SEAS NEAR 6 FT. OTHERWISE EXPECT WINDS
TO DROP DOWN TO 10 TO 15 KTS THROUGH THE PERIOD WITH SEAS CLOSER
TO SCA TUES BUT DROPPING DOWN THROUGH WED TO 2 TO 5 FT.
&&
.TIDES/COASTAL FLOODING...
AS OF 700 PM WEDNESDAY...THE FULL MOON IS TODAY. WE EXPECT
ELEVATED WATER LEVELS DURING THE TIME OF HIGH TIDE THROUGH THE
WEEKEND. THE MORNING HIGH TIDE WILL BE HIGHEST AND THIS IS WHEN WE
EXPECT THE TIDE TO COME UP WELL ONTO THE BEACH. STRONG NNE WINDS
SUNDAY AND SUNDAY NIGHT WILL HELP TO ENHANCE THE ASTRONOMICAL
EFFECTS. THE LOWER CAPE FEAR RIVER WILL ALSO EXPERIENCE HIGHER THAN
PREDICTED WATER LEVELS AND MAY REACH COASTAL FLOOD ADVISORY CRITERIA
DURING THE MORNING HIGH TIDE THROUGH THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM SUNDAY TO 6 AM EST MONDAY FOR
AMZ254-256.
GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR
AMZ250-252.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MJC/DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
344 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE. BASED ON UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID
CLOUDS...WILL TREND HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH
HIGHS RANGING FROM THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND
50 DEGREES OR SO IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR
INSOLATION WILL BE MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN
BAND...AND A TRAILING SEPARATE AREA OF SHALLOW CONVECTIVE
PRECIPITATION FORECAST TO MOVE ACROSS THE AREA LATER THIS AFTERNOON.
THAT TRAILING PRECIPITATION WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF A THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A
SURFACE LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST
NNE FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND
AREAS OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE
EASTWARD THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO
THIRDS OF THE CWFA. LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 340 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT: BRIEF SHORTWAVE RIDGING WILL BUILD EAST
ACROSS OUR REGION AND CAUSE STRONG ARCTIC HIGH PRESSURE CENTERED
OVER NEW ENGLAND TO RIDGE DOWN THE EAST COAST THIS PERIOD...IN
ADVANCE OF A PAIR OF PHASED (OR NEARLY SO) SHORTWAVE TROUGHS
FORECAST TO AMPLIFY FROM THE PLAINS TO THE MS VALLEY THROUGH SUN
NIGHT. DESPITE MAINLY CLEAR SKIES...EXCEPT SOME LINGERING LOW CLOUDS
OVER EASTERN NC...A BRISK AND GUSTY NE WIND WILL RESULT IN RATHER
CHILLY CONDITIONS...WITH HIGHS MOSTLY IN THE MID-UPPER 40S (TO NEAR
50 SOUTH). THE AMPLIFICATION OF THE AFOREMENTIONED TROUGHS ALOFT
WILL CAUSE THE LOW LEVEL FLOW (925 MB) TO ASSUME AN INCREASINGLY
EASTERLY COMPONENT (TOWARD THE PRESSURE FALLS ACCOMPANYING HE
APPROACHING TROUGH)..SUCH THAT THE LOW CLOUDS OVER THE EASTERN PART
OF THE STATE WILL DEVELOP/ADVECT WSW ACROSS CENTRAL NC THROUGH MON
MORNING. LOWS CENTERED IN THE MIDDLE 30S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 335 AM SATURDAY...
CONFIDENCE IS LOWER THAN DESIRED FOR A DAY 3 (MONDAY) FORECAST DUE
TO MODEL DIFFERENCES REGARDING THE INTERACTION OF NORTHERN AND
SOUTHERN STREAM SHORTWAVES AS THEY CROSS THE CENTRAL AND EASTERN US.
MODELS HAVE BEEN COMING INTO A LITTLE BETTER AGREEMENT...SHOWING THE
LEAD SOUTHERN STREAM SHORTWAVE MOVING FROM THE DEEP SOUTH ACROSS THE
CAROLINAS ON MONDAY...WITH A NORTHERN STREAM WAVE TO DIVE SOUTH
ACROSS THE REGION ON TUESDAY. IN RESPONSE TO THE LEAD WAVE...A
SURFACE LOW OFF THE SOUTHEAST COAST WILL RE-INTENSIFY AND LIFT NORTH
ALONG THE EAST COAST. THE NAM AND CANADIAN ARE STRONG OUTLIERS
REGARDING THE STRENGTH OF THE LOW AND ASSOCIATED PRECEDING EASTERLY
FLOW...PRODUCING HEAVIER PRECIP EARLIER ON MONDAY. THE ECMWF IS A
LITTLE MORE AMPLIFIED WITH THE LEAD WAVE...RESULTING MORE PRECIP
THAN THE GFS...BUT STILL RELATIVELY LIGHT AND NOT UNTIL MONDAY
AFTERNOON. THIS HAS SOME SIGNIFICANCE...AS A STRONG 1040+ MB
SURFACE HIGH EXTENDING INTO THE NC FROM NEW ENGLAND WILL BE
RETREATING DURING THE DAY BUT WOULD OFFER SOME PTYPE CONCERNS IN THE
NORTHWEST PIEDMONT WITH PRECIP EARLY MONDAY MORNING...AS THE NAM
DEPICTS. HOWEVER THIS IS DISCOUNTED AT THIS TIME. WILL SHOW POPS
INCREASING BY MIDDAY...SLIGHT CHANCE WEST TO CHANCE IN THE
EAST...ENDING FROM SOUTHWEST TO NORTHEAST MONDAY NIGHT AS THE
SURFACE LOW MOVES OFF TO THE NORTHEAST. THE QPF FORECAST IS FOR LESS
THAN A TENTH OF AN INCH...BUT WOULDNT BE SURPRISED TO SEE MODELS
PRODUCE MORE PRECIP IN LATER RUNS. HAVE LOWERED HIGHS A FEW DEGREES
ACROSS THE PIEDMONT BASED ON INCREASING POTENTIAL FOR
PRECIP...RANGING FROM LOWER 40S NORTHWEST TO NEAR 50 SOUTHEAST.
LOWS MONDAY NIGHT IN THE LOWER 30S NORTHEAST TO UPPER 30S SOUTHEAST.
A STRONG NORTHERN STREAM SHORTWAVE WILL DIVE ACROSS NC ON
TUESDAY....FOLLOWED BY A REINFORCING SHOT OF COLD ADVECTION TUESDAY
NIGHT. THE ECMWF SPITS OUT SOME VERY LIGHT QPF ACROSS THE NORTH
TUESDAY AFTERNOON...BUT WILL HOLD OFF ON INTRODUCING POPS AS MOISTURE
WILL BE LIMITED. HIGH PRESSURE IS THEN FORECAST TO BUILD ACROSS
THEN BUILD SLOWLY ACROSS THE SOUTHEAST BETWEEN AN UPPER LOW THAT
CLOSES OFF OVER NEW ENGLAND AND RIDGING OVER THE CENTRAL US. TEMPS
MAY SLOWLY MODERATE BUT WILL REMAIN AT OR JUST BELOW NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS HAS DEVELOPED AND SPREAD DIRECTLY ACROSS
THE CENTRAL CAROLINAS THIS MORNING...CENTERED FROM NEAR CAE TO RDU
TO TDF...OR JUST EAST OF THE TRIAD TERMINALS AND JUST WEST OF FAY.
THIS CLOUD BAND IS FORECAST TO HOLD RELATIVELY STATIONARY THROUGH
12Z...BEFORE SHIFTING EAST TOWARD RWI THROUGH 18Z. MEANWHILE...A PRE-
FRONTAL BAND OF RAIN AND OCCASIONAL IFR-MVFR CONDITIONS...AMIDST
OTHERWISE LOW VFR CEILINGS...WILL ARRIVE FROM THE WEST BETWEEN 10-
12Z AT WESTERN TERMINALS TO 14-17Z AT EASTERN ONES...BASICALLY ON
THE HEELS OF THE DEPARTING INITIAL BAND OF MVFR CEILINGS. THEN YET A
THIRD REGIME OF IFR-MVFR CONDITIONS AND NUMEROUS TO WIDESPREAD
SHOWERS (AND ISOLATED THUNDERSTORMS) WILL SWEEP EAST INTO OUR AREA
BETWEEN 17-19Z AT WESTERN TERMINALS TO BETWEEN 20-22Z AT EASTERN
ONES. THE PASSAGE OF A COLD FRONT AND FOLLOWING WNW BREEZE WILL HELP
SCOUR AND LIFT THE CLOUD LAYER...PARTICULARLY AT TRIAD TERMINALS
THIS EVENING...THOUGH SUB-VFR CONDITIONS AND AREAS OF LIGHT RAIN OR
DRIZZLE ARE APT TO LINGER THROUGHOUT THE NIGHT...ESPECIALLY AT
RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
335 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE. BASED ON UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID
CLOUDS...WILL TREND HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH
HIGHS RANGING FROM THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND
50 DEGREES OR SO IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR
INSOLATION WILL BE MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN
BAND...AND A TRAILING SEPARATE AREA OF SHALLOW CONVECTIVE
PRECIPITATION FORECAST TO MOVE ACROSS THE AREA LATER THIS AFTERNOON.
THAT TRAILING PRECIPITATION...WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF A THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A
SURFACE LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST
NNE FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND
AREAS OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE
EASTWARD THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO
THIRDS OF THE CWFA. LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 220 PM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE LATEST RUN OF THE ECMWF AGREES WELL
WITH THE GFS IN REGARD TO THE LOW AND ITS ASSOCIATED COLD FRONT
MOVING OFF THE CAROLINA COAST PRIOR TO 12Z SUNDAY. AS SUCH...HAVE A
DRY FORECAST FOR SUNDAY AND SUNDAY NIGHT. THE BIG QUESTION WILL BE
HOW QUICKLY THE SKIES CLEAR AND HOW THAT WILL AFFECT TEMPERATURES.
FOR NOW...EXPECT HIGHS IN THE UPPER 40S NW TO 723MID 50S SOUTH AND
EAST...ALTHOUGH IF SKIES CLEAR QUICKER/SLOWER THAT COULD CHANGE BY A
COUPLE/FEW DEGREES. LOWS GENERALLY IN LOW 30S NW TO UPPER 30S SE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 335 AM SATURDAY...
CONFIDENCE IS LOWER THAN DESIRED FOR A DAY 3 (MONDAY) FORECAST DUE
TO MODEL DIFFERENCES REGARDING THE INTERACTION OF NORTHERN AND
SOUTHERN STREAM SHORTWAVES AS THEY CROSS THE CENTRAL AND EASTERN US.
MODELS HAVE BEEN COMING INTO A LITTLE BETTER AGREEMENT...SHOWING THE
LEAD SOUTHERN STREAM SHORTWAVE MOVING FROM THE DEEP SOUTH ACROSS THE
CAROLINAS ON MONDAY...WITH A NORTHERN STREAM WAVE TO DIVE SOUTH
ACROSS THE REGION ON TUESDAY. IN RESPONSE TO THE LEAD WAVE...A
SURFACE LOW OFF THE SOUTHEAST COAST WILL RE-INTENSIFY AND LIFT NORTH
ALONG THE EAST COAST. THE NAM AND CANADIAN ARE STRONG OUTLIERS
REGARDING THE STRENGTH OF THE LOW AND ASSOCIATED PRECEDING EASTERLY
FLOW...PRODUCING HEAVIER PRECIP EARLIER ON MONDAY. THE ECMWF IS A
LITTLE MORE AMPLIFIED WITH THE LEAD WAVE...RESULTING MORE PRECIP
THAN THE GFS...BUT STILL RELATIVELY LIGHT AND NOT UNTIL MONDAY
AFTERNOON. THIS HAS SOME SIGNIFICANCE...AS A STRONG 1040+ MB
SURFACE HIGH EXTENDING INTO THE NC FROM NEW ENGLAND WILL BE
RETREATING DURING THE DAY BUT WOULD OFFER SOME PTYPE CONCERNS IN THE
NORTHWEST PIEDMONT WITH PRECIP EARLY MONDAY MORNING...AS THE NAM
DEPICTS. HOWEVER THIS IS DISCOUNTED AT THIS TIME. WILL SHOW POPS
INCREASING BY MIDDAY...SLIGHT CHANCE WEST TO CHANCE IN THE
EAST...ENDING FROM SOUTHWEST TO NORTHEAST MONDAY NIGHT AS THE
SURFACE LOW MOVES OFF TO THE NORTHEAST. THE QPF FORECAST IS FOR LESS
THAN A TENTH OF AN INCH...BUT WOULDNT BE SURPRISED TO SEE MODELS
PRODUCE MORE PRECIP IN LATER RUNS. HAVE LOWERED HIGHS A FEW DEGREES
ACROSS THE PIEDMONT BASED ON INCREASING POTENTIAL FOR
PRECIP...RANGING FROM LOWER 40S NORTHWEST TO NEAR 50 SOUTHEAST.
LOWS MONDAY NIGHT IN THE LOWER 30S NORTHEAST TO UPPER 30S SOUTHEAST.
A STRONG NORTHERN STREAM SHORTWAVE WILL DIVE ACROSS NC ON
TUESDAY....FOLLOWED BY A REINFORCING SHOT OF COLD ADVECTION TUESDAY
NIGHT. THE ECMWF SPITS OUT SOME VERY LIGHT QPF ACROSS THE NORTH
TUESDAY AFTERNOON...BUT WILL HOLD OFF ON INTRODUCING POPS AS MOISTURE
WILL BE LIMITED. HIGH PRESSURE IS THEN FORECAST TO BUILD ACROSS
THEN BUILD SLOWLY ACROSS THE SOUTHEAST BETWEEN AN UPPER LOW THAT
CLOSES OFF OVER NEW ENGLAND AND RIDGING OVER THE CENTRAL US. TEMPS
MAY SLOWLY MODERATE BUT WILL REMAIN AT OR JUST BELOW NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS HAS DEVELOPED AND SPREAD DIRECTLY ACROSS
THE CENTRAL CAROLINAS THIS MORNING...CENTERED FROM NEAR CAE TO RDU
TO TDF...OR JUST EAST OF THE TRIAD TERMINALS AND JUST WEST OF FAY.
THIS CLOUD BAND IS FORECAST TO HOLD RELATIVELY STATIONARY THROUGH
12Z...BEFORE SHIFTING EAST TOWARD RWI THROUGH 18Z. MEANWHILE...A PRE-
FRONTAL BAND OF RAIN AND OCCASIONAL IFR-MVFR CONDITIONS...AMIDST
OTHERWISE LOW VFR CEILINGS...WILL ARRIVE FROM THE WEST BETWEEN 10-
12Z AT WESTERN TERMINALS TO 14-17Z AT EASTERN ONES...BASICALLY ON
THE HEELS OF THE DEPARTING INITIAL BAND OF MVFR CEILINGS. THEN YET A
THIRD REGIME OF IFR-MVFR CONDITIONS AND NUMEROUS TO WIDESPREAD
SHOWERS (AND ISOLATED THUNDERSTORMS) WILL SWEEP EAST INTO OUR AREA
BETWEEN 17-19Z AT WESTERN TERMINALS TO BETWEEN 20-22Z AT EASTERN
ONES. THE PASSAGE OF A COLD FRONT AND FOLLOWING WNW BREEZE WILL HELP
SCOUR AND LIFT THE CLOUD LAYER...PARTICULARLY AT TRIAD TERMINALS
THIS EVENING...THOUGH SUB-VFR CONDITIONS AND AREAS OF LIGHT RAIN OR
DRIZZLE ARE APT TO LINGER THROUGHOUT THE NIGHT...ESPECIALLY AT
RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...WSS
LONG TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE. BASED ON UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID
CLOUDS...WILL TREND HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH
HIGHS RANGING FROM THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND
50 DEGREES OR SO IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR
INSOLATION WILL BE MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN
BAND...AND A TRAILING SEPARATE AREA OF SHALLOW CONVECTIVE
PRECIPITATION FORECAST TO MOVE ACROSS THE AREA LATER THIS AFTERNOON.
THAT TRAILING PRECIPITATION...WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF A THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A
SURFACE LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST
NNE FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND
AREAS OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE
EASTWARD THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO
THIRDS OF THE CWFA. LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 220 PM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE LATEST RUN OF THE ECMWF AGREES WELL
WITH THE GFS IN REGARD TO THE LOW AND ITS ASSOCIATED COLD FRONT
MOVING OFF THE CAROLINA COAST PRIOR TO 12Z SUNDAY. AS SUCH...HAVE A
DRY FORECAST FOR SUNDAY AND SUNDAY NIGHT. THE BIG QUESTION WILL BE
HOW QUICKLY THE SKIES CLEAR AND HOW THAT WILL AFFECT TEMPERATURES.
FOR NOW...EXPECT HIGHS IN THE UPPER 40S NW TO 723MID 50S SOUTH AND
EAST...ALTHOUGH IF SKIES CLEAR QUICKER/SLOWER THAT COULD CHANGE BY A
COUPLE/FEW DEGREES. LOWS GENERALLY IN LOW 30S NW TO UPPER 30S SE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 220 PM FRIDAY...
MONDAY THROUGH FRIDAY: CONFIDENCE IS STILL NOT TERRIBLY HIGH FOR
NEXT WEEK...HOWEVER IT HAS INCREASED SOME OVERALL AS THE MODELS
APPEAR TO BE SLOWLY COMING INTO BETTER AGREEMENT. THE ECMWF SEEMS TO
BE TRENDING MORE TOWARD THE GFS WITH THE UPPER LEVEL LOW THAT MOVES
THROUGH THE GREAT LAKES AND NORTHEAST U.S. TOWARD THE END OF NEXT
WEEK. ALTHOUGH IT CONTINUES TO BE DEEPER WITH THE UPPER LEVEL TROUGH
AND STILL TRIES TO GENERATE A BIT OF PRECIPITATION OVER PORTIONS OF
THE CAROLINAS EARLY IN THE WEEK. THERE IS STILL SOME UNCERTAINTY
WITH RESPECT TO THAT LOW...AND GIVEN THE MODEL TREND...EXPECT IT TO
STAY MAINLY WELL NORTH OF THE REGION AND BE OF LITTLE CONSEQUENCE IN
THE PRECIPITATION DEPARTMENT FOR CENTRAL NC AT THIS TIME. WITH THAT
HYPOTHESIS IN MIND...EXPECT NEXT WEEK TO BE GENERALLY DRY...WITH
HIGH PRESSURE DOMINATING AT THE SURFACE. THE FIRST HIGH WILL RIDGE
IN FROM THE NORTHEAST AND RESULT IN A WEDGE OF A COLD AIR OVER THE
AREA. A REINFORCING SHOT OF COLD AIR WILL PUSH THROUGH THE AREA
TUESDAY NIGHT INTO WEDNESDAY...WITH ANOTHER AREA OF HIGH PRESSURE
SUBSEQUENTLY BUILDING IN THROUGH THE END OF THE WEEK. HIGHS ON
MONDAY WILL BE THE COOLEST OF THE PERIOD...MID 40S NW TO LOW 50S SE.
HIGHS WILL CONTINUE TO BE A LITTLE BIT OF A RO723LLER COASTER
THROUGH THE REST OF THE WEEK...WITH LOW TO MID 50S EXPECTED ON
TUESDAY AND FRIDAY...BUT UPPER 40S TO LOW 50S WEDNESDAY AND
THURSDAY. LOWS WILL GENERALLY DECREASE FROM THE LOW 30S NW TO UPPER
30S SE MONDAY NIGHT TO UPPER 20S ACROSS THE AREA BY WED AND THU
NIGHTS...MODERATING AGAIN INTO THE LOW 30S FRI NIGHT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS HAS DEVELOPED AND SPREAD DIRECTLY ACROSS
THE CENTRAL CAROLINAS THIS MORNING...CENTERED FROM NEAR CAE TO RDU
TO TDF...OR JUST EAST OF THE TRIAD TERMINALS AND JUST WEST OF FAY.
THIS CLOUD BAND IS FORECAST TO HOLD RELATIVELY STATIONARY THROUGH
12Z...BEFORE SHIFTING EAST TOWARD RWI THROUGH 18Z. MEANWHILE...A PRE-
FRONTAL BAND OF RAIN AND OCCASIONAL IFR-MVFR CONDITIONS...AMIDST
OTHERWISE LOW VFR CEILINGS...WILL ARRIVE FROM THE WEST BETWEEN 10-
12Z AT WESTERN TERMINALS TO 14-17Z AT EASTERN ONES...BASICALLY ON
THE HEELS OF THE DEPARTING INITIAL BAND OF MVFR CEILINGS. THEN YET A
THIRD REGIME OF IFR-MVFR CONDITIONS AND NUMEROUS TO WIDESPREAD
SHOWERS (AND ISOLATED THUNDERSTORMS) WILL SWEEP EAST INTO OUR AREA
BETWEEN 17-19Z AT WESTERN TERMINALS TO BETWEEN 20-22Z AT EASTERN
ONES. THE PASSAGE OF A COLD FRONT AND FOLLOWING WNW BREEZE WILL HELP
SCOUR AND LIFT THE CLOUD LAYER...PARTICULARLY AT TRIAD TERMINALS
THIS EVENING...THOUGH SUB-VFR CONDITIONS AND AREAS OF LIGHT RAIN OR
DRIZZLE ARE APT TO LINGER THROUGHOUT THE NIGHT...ESPECIALLY AT
RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...WSS
LONG TERM...KC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 AM EST SAT DEC 6 2014
.SYNOPSIS...A COLD FRONT WILL APPROACH FROM THE WEST TODAY...THEN
CROSS OUR REGION THIS EVENING. HIGH PRESSURE WILL FOLLOW FOR SUNDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 1010 PM FRIDAY...
TWO MAIN FORECAST PROBLEMS FOR THIS EVENING...THE FIRST...WILL THERE
BE FOG ACROSS THE SOUTHERN COUNTIES...AND SECOND...THE ARRIVAL TIME
OF THE PRECIPITATION ON SATURDAY. ADDRESSING THE FOG...MUCH OF
CENTRAL NC REMAINS ENSHROUDED IN CLOUD COVER WITH SOME CLEARING
ACROSS THE SOUTHWEST. VISIBILITIES FOR THE MOST PART HAVE REMAINED
ABOVE TEN MILES AS DEWPOINT DEPRESSIONS HAVE ALSO REMAINED PLUS OR
MINUS FIVE DEGREES. AS THE AREA OF CLEARING OVER THE SOUTHWEST MOVES
EASTWARD...THERE COULD BE A FEW HOURS BEFORE SUNRISE WHEN THE
TEMPERATURE DROPS TO THE DEWPOINT AND SOME PATCHY DENSE FOG WILL BE
POSSIBLE. FOR THE MOST PART HOWEVER...LOW STRATUS WILL BE THE MORE
LIKELY SCENARIO WITH SEVERAL SITES IN THE SANDHILLS ALREADY SHOWING
MVFR CEILINGS.
THE MAIN SYSTEM THAT IS EXPECTED TO GENERATE PRECIPITATION OVER THE
AREA ON SATURDAY REMAINS OVER THE TENNESSEE VALLEY AND SHORT TERM
MODELS ARE PROGGING THE ARRIVAL OF THE PRECIP TO BE A LITTLE BIT
LATER THAN PREVIOUSLY ANTICIPATED. HAVE CUT BACK ON POPS SATURDAY
MORNING AND BLEND INTO HIGHER POPS STILL EXPECTED FOR SATURDAY
AFTERNOON/EVENING. THE LATEST RAP MODEL ACTUALLY SHOWS PRECIP IN OUR
CWA BEGINNING FIRST IN THE EAST IN ASSOCIATION WITH A SMALLER WAVE
MOVING IN OFF OF THE SW ATLANTIC AFTER 9Z AND THEN PRECIPITATION
ASSOCIATED WITH THE WESTERN SYSTEM APPROACHING THE NW PIEDMONT AFTER
12Z SATURDAY.
LOWS TONIGHT WILL RANGE FROM THE LOW TO MIDDLE 40S.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 310 PM FRIDAY...
SATURDAY... S/W AND ASSOCIATED SURFACE FRONT WILL BE TO OUR WEST AT
18Z...CROSSING OUR REGION SATURDAY EVENING. LOW-MID LEVEL SOUTH-
SOUTHWEST FLOW WILL ADVECT ABUNDANT MOISTURE INTO OUR REGION.
MEANWHILE SUFFICIENT LIFT WILL BE PROVIDED BY: A.) DIVERGENCE ALOFT
DUE TO THE CAROLINAS BEING IN THE FAVORABLE POSITION OF TWO JETS
(ONE EXITING NEW ENGLAND WHILE THE OTHER DIVING SEWD ACROSS THE TN
VALLEY); B.) 40-60M/12 HOUR MID LEVEL HEIGHT FALLS; C.) AND LATER IN
THE DAY, CONVERGENCE ALONG THE SFC-850MB COLD FRONT. THIS FAVORABLE
ATMOSPHERE SHOULD CAUSE NUMEROUS SHOWERS TO OVERSPREAD THE PIEDMONT
AND THE NORTHERN COASTAL PLAIN DURING THE MORNING HOURS...AND INTO
THE SANDHILLS AND THE REMAINDER OF THE COASTAL PLAIN IN THE
AFTERNOON.
POTENTIAL EXISTS FOR A FEW THUNDERSTORMS TO OCCUR SATURDAY AFTERNOON-
EARLY EVENING AS MID LEVEL LAPSE RATES REACH AS HIGH AS 6.5-7 DEG
C/KM AND BULK SHEAR ACHIEVES FAVORABLE VALUES 30-35KTS. LOW LEVEL
INSTABILITY LACKING AS SBCAPE IS AOB 200 J/KG WHILE MUCAPE NO HIGHER
THAN 200-250 J/KG LATE SATURDAY-SATURDAY EVENING. THUS...EXPECT
CONVECTION TO BE ELEVATED WITH LITTLE IF ANY CHANCE OF STORMS
BECOMING STRONG/SEVERE.
HIGH TEMPS SATURDAY STILL A CHALLENGE...DEPENDENT UPON EXTENT OF
RAIN SHOWERS. STILL FAVOR MAX TEMPS SLIGHTLY COOLER THAN GUIDANCE
ACROSS THE PIEDMONT AS A SHORT-LIVED IN-SITU OR HYBRID CAD MAY SET
UP EARLY SATURDAY. CONVERSELY...IF SHOWERS HOLD OFF LONG
ENOUGH...TEMPS IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN MAY WARM
INTO THE MID-UPPER 60S.
SATURDAY NIGHT... SURFACE COLD FRONT PROGRESSES EAST ACROSS CENTRAL
NC IN THE EVENING...EXITING OUR COASTAL PLAIN COUNTIES AROUND OR
SHORTLY AFTER MIDNIGHT. THE 850-700MB TROUGHS FOLLOW SHORTLY
AFTERWARDS. LOW-MID LEVEL N-NW FLOW IN THE WAKE OF THE TROUGH
PASSAGE WILL AID TO DIMINISH SHOWER COVERAGE IN THE WEST SATURDAY
EVENING...AND OVERNIGHT IN THE EAST. PARTIAL CLEARING SHOULD
INITIATE IN THE NORTH-NW AFTER MIDNIGHT. SURFACE FRONTAL PASSAGE
WILL BE NOTED BY WINDS VEERING TO THE N-NW AND INITIALLY GUSTING
AROUND 20KTS. MIN TEMPS LOW-MID 40S NORTH TO UPPER 40S SE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 220 PM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE LATEST RUN OF THE ECMWF AGREES WELL
WITH THE GFS IN REGARD TO THE LOW AND ITS ASSOCIATED COLD FRONT
MOVING OFF THE CAROLINA COAST PRIOR TO 12Z SUNDAY. AS SUCH...HAVE A
DRY FORECAST FOR SUNDAY AND SUNDAY NIGHT. THE BIG QUESTION WILL BE
HOW QUICKLY THE SKIES CLEAR AND HOW THAT WILL AFFECT TEMPERATURES.
FOR NOW...EXPECT HIGHS IN THE UPPER 40S NW TO 723MID 50S SOUTH AND
EAST...ALTHOUGH IF SKIES CLEAR QUICKER/SLOWER THAT COULD CHANGE BY A
COUPLE/FEW DEGREES. LOWS GENERALLY IN LOW 30S NW TO UPPER 30S SE.
MONDAY THROUGH FRIDAY: CONFIDENCE IS STILL NOT TERRIBLY HIGH FOR
NEXT WEEK...HOWEVER IT HAS INCREASED SOME OVERALL AS THE MODELS
APPEAR TO BE SLOWLY COMING INTO BETTER AGREEMENT. THE ECMWF SEEMS TO
BE TRENDING MORE TOWARD THE GFS WITH THE UPPER LEVEL LOW THAT MOVES
THROUGH THE GREAT LAKES AND NORTHEAST U.S. TOWARD THE END OF NEXT
WEEK. ALTHOUGH IT CONTINUES TO BE DEEPER WITH THE UPPER LEVEL TROUGH
AND STILL TRIES TO GENERATE A BIT OF PRECIPITATION OVER PORTIONS OF
THE CAROLINAS EARLY IN THE WEEK. THERE IS STILL SOME UNCERTAINTY
WITH RESPECT TO THAT LOW...AND GIVEN THE MODEL TREND...EXPECT IT TO
STAY MAINLY WELL NORTH OF THE REGION AND BE OF LITTLE CONSEQUENCE IN
THE PRECIPITATION DEPARTMENT FOR CENTRAL NC AT THIS TIME. WITH THAT
HYPOTHESIS IN MIND...EXPECT NEXT WEEK TO BE GENERALLY DRY...WITH
HIGH PRESSURE DOMINATING AT THE SURFACE. THE FIRST HIGH WILL RIDGE
IN FROM THE NORTHEAST AND RESULT IN A WEDGE OF A COLD AIR OVER THE
AREA. A REINFORCING SHOT OF COLD AIR WILL PUSH THROUGH THE AREA
TUESDAY NIGHT INTO WEDNESDAY...WITH ANOTHER AREA OF HIGH PRESSURE
SUBSEQUENTLY BUILDING IN THROUGH THE END OF THE WEEK. HIGHS ON
MONDAY WILL BE THE COOLEST OF THE PERIOD...MID 40S NW TO LOW 50S SE.
HIGHS WILL CONTINUE TO BE A LITTLE BIT OF A RO723LLER COASTER
THROUGH THE REST OF THE WEEK...WITH LOW TO MID 50S EXPECTED ON
TUESDAY AND FRIDAY...BUT UPPER 40S TO LOW 50S WEDNESDAY AND
THURSDAY. LOWS WILL GENERALLY DECREASE FROM THE LOW 30S NW TO UPPER
30S SE MONDAY NIGHT TO UPPER 20S ACROSS THE AREA BY WED AND THU
NIGHTS...MODERATING AGAIN INTO THE LOW 30S FRI NIGHT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS HAS DEVELOPED AND SPREAD DIRECTLY ACROSS
THE CENTRAL CAROLINAS THIS MORNING...CENTERED FROM NEAR CAE TO RDU
TO TDF...OR JUST EAST OF THE TRIAD TERMINALS AND JUST WEST OF FAY.
THIS CLOUD BAND IS FORECAST TO HOLD RELATIVELY STATIONARY THROUGH
12Z...BEFORE SHIFTING EAST TOWARD RWI THROUGH 18Z. MEANWHILE...A PRE-
FRONTAL BAND OF RAIN AND OCCASIONAL IFR-MVFR CONDITIONS...AMIDST
OTHERWISE LOW VFR CEILINGS...WILL ARRIVE FROM THE WEST BETWEEN 10-
12Z AT WESTERN TERMINALS TO 14-17Z AT EASTERN ONES...BASICALLY ON
THE HEELS OF THE DEPARTING INITIAL BAND OF MVFR CEILINGS. THEN YET A
THIRD REGIME OF IFR-MVFR CONDITIONS AND NUMEROUS TO WIDESPREAD
SHOWERS (AND ISOLATED THUNDERSTORMS) WILL SWEEP EAST INTO OUR AREA
BETWEEN 17-19Z AT WESTERN TERMINALS TO BETWEEN 20-22Z AT EASTERN
ONES. THE PASSAGE OF A COLD FRONT AND FOLLOWING WNW BREEZE WILL HELP
SCOUR AND LIFT THE CLOUD LAYER...PARTICULARLY AT TRIAD TERMINALS
THIS EVENING...THOUGH SUB-VFR CONDITIONS AND AREAS OF LIGHT RAIN OR
DRIZZLE ARE APT TO LINGER THROUGHOUT THE NIGHT...ESPECIALLY AT
RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...ELLIS
SHORT TERM...WSS
LONG TERM...KC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
124 AM EST SAT DEC 6 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A COASTAL TROUGH WILL
LIFT NORTH AS A WARM FRONT ON SATURDAY...AHEAD OF A COLD FRONT
WHICH WILL MOVE ACROSS THE AREA SATURDAY NIGHT. THIS COLD FRONT
WILL BRING A PERIOD OF SHOWERS WITH AN ISOLATED THUNDERSTORM
POSSIBLE. A STRONG WEDGE OF HIGH PRESSURE WILL BUILD SOUTH SUNDAY
AND MONDAY...BRINGING GUSTY NORTH WINDS AND MUCH COOLER
TEMPERATURES. CANADIAN HIGH PRESSURE NEXT WEEK WILL MAINTAIN
SEASONABLY COOL TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 124 AM SATURDAY...A COASTAL TROUGH DEVELOPING ACROSS THE
WATERS IS EXPECTED TO DRIFT TO THE COAST OVERNIGHT. CONVERGENT
FLOW IN ASSOCIATION WITH THE TROUGH SHOULD HELP TO BRING SOME OF
THE OFFSHORE SHOWERS ONTO THE COAST LATE TONIGHT. THE HIGH
RESOLUTION HRRR IS MOST BULLISH WITH THIS SCENARIO...PRIMARILY FOR
THE CAPE FEAR AREA LATE TONIGHT. OTHERWISE AS CHILLY HIGH PRESSURE
DRIFTS OFFSHORE AND A TROUGH APPROACHES FROM THE W...A DEEP S TO
SW FLOW WILL ENVELOP THE EASTERN CAROLINAS. THE COLUMN WILL
CONTINUE TO SLOWLY MOISTEN...PRECIPITABLE WATER VALUES WILL REACH
NEAR 1.25 INCHES BY SUNRISE. SHOWERS ASSOCIATED WITH THE
AFOREMENTIONED TROUGH WILL REMAIN W OF THE FORECAST AREA INTO
EARLY SAT MORNING. A WARM AIR ADVECTION PATTERN AND INCREASING
MOISTURE CONTENT WILL BRING A GOOD DEAL OF CLOUDINESS THROUGH THE
NIGHT. THE CLOUDS SHOULD HELP TO FLATTEN THE TEMP CURVE WITH LOWS
MAINLY IN THE MID AND UPPER 40S INLAND AND LOWER 50S AT THE
COAST...SO LITTLE TEMP MOVEMENT THROUGH THE NIGHT. ALTHOUGH MODELS
ARE INDICATING A PRONOUNCED NEAR SURFACE INVERSION DEVELOPING...THEY
ARE RELUCTANT TO SATURATE THE LEVEL CLOSEST TO THE GROUND. ALSO...
USING A UPS FOG METHODOLOGY GRIDDED SMART TOOL...FOG IS EXPECTED TO
DEVELOP W OF THE FORECAST AREA AND ADVECT NORTHWARD WITH TIME.
THUS...STILL LOOKS AS THOUGH SIGNIFICANT FOG WILL HAVE A DIFFICULT
TIME DEVELOPING AND WILL FAVOR LOW STRATUS OVER FOG AT THIS
TIME...BUT CONTINUE TO MONITOR NEAR TERM TRENDS. THIS LOW STRATUS
MAY PRODUCE SOME SPOTTY DRIZZLE FROM TIME TO TIME AND HAVE ADDED
PATCHY DRIZZLE TO THE FORECAST TOWARD MORNING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...COASTAL TROUGH LIFTING NORTH AS A WARM
FRONT SATURDAY MORNING WILL CREATE A WARM DAY...ESPECIALLY ALONG
THE COAST...BUT RAIN CHANCES WILL INCREASE RAPIDLY LATE IN THE
DAY. AS THE COASTAL TROUGH LIFTS NORTH EARLY...WAA WILL FOLLOW
THROUGH THE AFTN...WITH 850MB TEMPS CLIMBING TO AROUND 10C BY
SATURDAY AFTN. AS THIS OCCURS HOWEVER...CLOUD COVER WILL BE ON THE
INCREASE THANKS TO MOIST ADVECTION AND PVA AHEAD OF A SHORTWAVE
WHICH WILL MOVE JUST NORTH OF THE AREA SATURDAY NIGHT. BENEATH
THIS SHORTWAVE...A SURFACE LOW WILL PUSH EAST NEAR THE NC/VA
BORDER...DRAGGING A COLD FRONT ACROSS THE CWA SATURDAY NIGHT. AS
PWATS RISE TO ABOUT 1.25 INCHES AND MID-LEVEL LAPSE RATES CLIMB
TOWARDS 7C/KM...SCATTERED SHOWERS WITH ISOLATED TSTMS ARE
EXPECTED. INSTABILITY REMAINS MINIMAL...BUT CANNOT RULE OUT A FEW
LIGHTNING STRIKES...AND THIS IS ECHOED BY THE GENERAL RISK
ENCOMPASSING THE ILM CWA IN THE SWODY2. TOTAL QPF WILL NOT BE VERY
HIGH...BUT BRIEF PERIODS OF HEAVY RAIN IS POSSIBLE WITHIN A FEW
HOURS EITHER SIDE OF SATURDAY EVENING. COOL ADVECTION BEGINS IN
EARNEST BEHIND THE COLD FRONT LATE SATURDAY NIGHT...SO TEMPS WHICH
WILL RISE TOWARDS 70 ALONG THE COAST SATURDAY AFTN...MID 60S WELL
INLAND...WILL DROP RAPIDLY INTO THE LOW 40S WELL NW...TO AROUND 50
AT THE COAST...BY SUNDAY MORNING.
A QUIETER BUT MUCH COOLER DAY ON SUNDAY AS A STRONG WEDGE OF HIGH
PRESSURE DEVELOPS BEHIND THE COLD FRONT FROM SATURDAY NIGHT. WITH
LOW-LEVEL MOISTURE PROGGED TO REMAIN HIGH BENEATH THE WEDGE...PARTLY
TO MOSTLY CLOUDY CONDITIONS WILL PERSIST MUCH OF SUNDAY. THIS
COMBINED WITH COOL ADVECTION WILL LIMIT WARMING...AND HIGHS MAY BE
REACHED VERY EARLY IN THE DAY...WITH LITTLE DIURNAL RANGE. EXPECT
HIGHS ONLY IN THE LOW 50S IN THE FAR NORTH...TO MID 50S IN THE
SOUTH. SOME CLEARING WILL OCCUR VERY LATE...AND CONTINUED CAA WILL
HELP MINS FALL INTO THE UPPER 30S SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE MID LEVEL PATTERN WILL BE QUITE
PROGRESSIVE THROUGH THE PERIOD WITH THE AREA REMAINING VOID OF ANY
SIGNIFICANT PRECIPITATION. INITIALLY A LINGERING LOW PRESSURE
SYSTEM OFF THE SOUTHEAST COAST MAY PROVIDE A FEW SHOWERS...MORESO
ALONG THE COAST MONDAY BEFORE A COLD FRONT...ASSOCIATED WITH
FAIRLY STRONG SHORTWAVE MOVING THROUGH THE MIDWEST SWEEPS THE AREA
CLEAN. BEYOND THIS A WEAKENING CYCLONIC FLOW ALOFT WILL PREVAIL
ACROSS THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BUILD DOWN
FROM THE UPPER MIDWEST TO ESSENTIALLY OVER THE AREA BY FRIDAY THUS
A DRY FORECAST. TEMPERATURES TRENDS LOOK A LITTLE BELOW
CLIMATOLOGY WITH HIGHS MOSTLY IN THE 50S AND LOWS IN THE LOWER TO
MIDDLE 30S
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE ON THE BACK END OF THE FORECAST
PERIOD WITH RESPECT TO CEILINGS AND THE TIMING OF PRECIP. LOOKS LIKE
THERE COULD BE TWO BATCHES OF RAIN/SHOWERS: THE FIRST AROUND SUNRISE
WITH A COASTAL TROUGH...THEN ANOTHER ROUND IN THE LATE AFTERNOON
AHEAD OF A COLD FRONT. MODELS ARE IN REASONABLE AGREEMENT
INTRODUCING IFR STRATUS/FOG AROUND DAYBREAK IF NOT BEFORE...AND THIS
MAKES SENSE GIVEN THE WEAK WARM AIR ADVECTION. THE HRRR MODEL THINKS
THAT ILM STANDS THE BEST CHANCE FOR MORNING PRECIP...BUT THE MYRTLES
COULD ALSO GET INTO THE ACT. THINK THE MORNING PRECIP WILL GIVE WAY
TO MVFR CEILINGS AND SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT WHICH
WILL ARRIVE AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...PERIODS OF MVFR/IFR CIGS ARE LIKELY THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK. GUSTY NORTH WINDS SUN/MON BEHIND
THE COLD FRONT. BECOMING VFR DURING TUE. VFR WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 125 PM SATURDAY...A COASTAL TROUGH WILL BE IN CLOSE PROXIMITY
THROUGH TONIGHT AND LIKELY JUST ABOUT ON THE IMMEDIATE COAST AROUND
DAYBREAK SAT. NE WINDS ARE EXPECTED TO SHIFT TO THE E OR ESE
OVERNIGHT WITH ITS PASSAGE. WIND SPEEDS WILL BE UP TO 10 TO 15 KT
LATE THIS EVE...DECREASING TO 10 KT OR LESS OVERNIGHT. SEAS WILL BE
3 TO 4 FT WITH A 8 TO 10 SECOND EASTERLY SWELL PRESENT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...QUIET MARINE CONDITIONS TO START THE
PERIOD...BUT RAPID DETERIORATION IS EXPECTED ON SUNDAY. WEAK
COASTAL TROUGH WILL LIFT NORTH ON SATURDAY...WITH WINDS TURNING
FROM SE TO SW THROUGH THE AFTN...BUT AT LIGHT SPEEDS. LOW PRESSURE
MOVING NORTH OF THE AREA WILL DRAG A COLD FRONT ACROSS THE WATERS
SATURDAY NIGHT...AND WINDS WILL TURN ABRUPTLY TO THE NORTH AT
15-20 KTS BY SUNDAY MORNING. SEAS ON SATURDAY WILL BE GENERALLY
2-4 FT REGARDLESS OF WIND DIRECTION...BUT WILL BEGIN TO RISE LATE
BEHIND THE COLD FRONT.
GALE WATCH HAS BEEN HOISTED FOR THE NC WATERS BEGINNING SUNDAY
MORNING...AND THERE IS PRETTY HIGH CONFIDENCE IN A GALE OCCURRING
SUNDAY AS A STRONG WEDGE OF HIGH PRESSURE BUILDS DOWN THE COAST.
THIS WILL CAUSE A TIGHT GRADIENT OVER THE WATERS...AND WIND WILL
BECOME NE AT 20-30 KTS ON SUNDAY...WITH FREQUENT GUSTS TO 35 KTS OR
MORE EXPECTED ACROSS THE NC WATERS. THERE IS LOWER CONFIDENCE IN
GALE-FORCE WINDS ACROSS SC WATERS...BUT AT LEAST A STRONG SMALL
CRAFT ADVISORY IS EXPECTED. THESE STRONG WINDS WILL ALSO PUSH SEAS
UP TO TO 5-9 FT ON SUNDAY...WITH THE EXCEPTION BEING THE WAVE
SHADOWED REGION SW OF BRUNSWICK COUNTY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...NEXT WEEK WILL NOT BE THE BEST OF TIMES FOR
THE MARINE COMMUNITY AS BLUSTERY CONDITIONS AND ELEVATED SEAS WILL
CONTINUE. FOR MONDAY A POTENT NORTHERLY FLOW WILL CONTINUE AS LOW
PRESSURE MOVES WELL OFF TO THE NORTHEAST AND MASSIVE HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. EXPECT WINDS OF 20-25 KNOTS...POSSIBLY
HIGHER WITH CERTAIN SMALL CRAFT CONDITIONS AND POSSIBLY GALES. THE
WINDS DO DIMINISH THROUGHOUT THE DAY TO SETTLE AT 10-15 KNOTS BY
TUESDAY MORNING. HERE THE WINDS WILL REMAIN THROUGH WEDNESDAY. SEAS
WILL BE HIGHEST MONDAY WITH 3-6 FEET DROPPING TO 2-5 FEET TUESDAY
AND WEDNESDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 700 PM WEDNESDAY...THE FULL MOON IS ON SATURDAY. WE EXPECT
ELEVATED WATER LEVELS DURING THE TIME OF HIGH TIDE THROUGH THE
WEEKEND. THE MORNING HIGH TIDE WILL BE HIGHEST AND THIS IS WHEN WE
EXPECT THE TIDE TO COME UP WELL ONTO THE BEACH. STRONG NNE WINDS
SUNDAY AND SUNDAY NIGHT WILL HELP TO ENHANCE THE ASTRONOMICAL
EFFECTS. THE LOWER CAPE FEAR RIVER WILL ALSO EXPERIENCE HIGHER THAN
PREDICTED WATER LEVELS AND MAY REACH COASTAL FLOOD ADVISORY CRITERIA
DURING THE MORNING HIGH TIDE THROUGH THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR AMZ250-252.
&&
$$
NEAR TERM...RJD/8
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...DL
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1243 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1242 AM CST SAT DEC 6 2014
CHANGES FOR THIS UPDATE INCLUDE...INCREASED OVERNIGHT LOW
TEMPERATURES...INCREASED CLOUD COVER.
LOW STRATUS CONTINUES TO BUILD EAST ACROSS NORTH DAKOTA. THIS
THICK STRATUS DECK HAS INHIBITED DIURNAL COOLING.
THEREFORE...INCREASED OVERNIGHT LOW TEMPERATURES FOR LOCATIONS
UNDER THIS CLOUD DECK. SPEAKING OF CLOUDS...INCREASED COVERAGE AND
DURATION OF THE CLOUD COVER THROUGH THE MORNING EARLY MORNING
HOURS. LATEST SATELLITE TRENDS AND SHORT-TERM GUIDANCE SUGGESTS
THIS THICK CLOUD COVER WILL REMAIN ENTRENCHED OVER NORTH DAKOTA
UNTIL LATER THIS MORNING WHEN WAA ADVECTION KICKS IN IN ERNEST.
A SCATTERED LIGHT WINTRY MIX CONTINUES ACROSS PORTIONS OF
SOUTHWEST NORTH DAKOTA WHERE WARMER AIR ALOFT HAS PUSHED NORTH.
WILL MONITOR THIS DEVELOPMENT AS ADJUSTMENTS MAY BE NEEDED TO THE
PRECIP FORECAST FOR THE EARLY MORNING HOURS.
UPDATE ISSUED AT 923 PM CST FRI DEC 5 2014
FOR LATE EVENING UPDATE MAIN CONCERN WAS PRECIPITATION OVER THE
FAR SOUTHWEST. LATEST HIGH-RES MODELS WERE HAVING SOME TROUBLE ON
PLACEMENT OF PRECIPITATION THIS EVENING...BUT REGIONAL RADAR
MOSAIC ALONG WITH BOWMAN ARB RADAR INDICATED VERY LIGHT
PRECIPITATION SHIFTING TOWARDS WEST CENTRAL AND SOUTHWEST NORTH
DAKOTA. THEREFORE...HAVE SPREAD LOW POPS THROUGH THE SOUTHWEST.
NEXT CONCERN WAS PRECIP TYPE AS SOME WARMER AIR ALOFT IS STARTING
TO PUSH TOWARDS THE FAR SOUTHWEST. WITH THIS...HAVE ADDED THE
MENTION OF POSSIBLE SLEET/FREEZING RAIN...ALTHOUGH CHANCES AND
COVERAGE WILL BE VERY LOW. ONLY OTHER CHANGE FOR UPDATE WAS
DROPPING LOW TEMPERATURES A BIT OVER THE NORTHWEST/NORTH CENTRAL
AS OBBS JUST NORTH OF THE CANADIAN BORDER HAVE ALREADY DIPPED DOWN
TOWARDS ZERO. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 621 PM CST FRI DEC 5 2014
MAIN CHANGE FOR EARLY EVENING UPDATE WAS TO INCREASE CLOUD COVER
ACROSS ALL AREAS EXCEPT FAR SOUTH CENTRAL/JAMES RIVER VALLEY AS
BROAD AREA CONTINUES TO SHIFT SOUTHEAST. WILL HAVE TO KEEP AN
EYE ON TEMPERATURES THROUGH THE EVENING AS WHEREVER THERE ARE
BREAKS IN THE CLOUD COVER OVER THE NORTH...THE TEMPERATURE HAS
DROPPED QUICKLY. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
CURRENTLY...HIGH PRESSURE OVER NORTHWEST NORTH DAKOTA THIS EARLY
AFTERNOON IS FORECAST TO MOVE EAST ACROSS THE FORECAST AREA
TONIGHT. IFR STRATUS REMAINS OVER NORTHWEST NORTH DAKOTA FROM
CROSBY AND WILLISTON...EAST TO STANLEY...BUT HAVING A HARD TIME
MAKING IT MUCH FARTHER EAST THIS AFTERNOON. TEMPERATURES RANGED
FROM THE UPPER TEENS-LOW 20S NORTH TO UPPER 20S-LOW 30S SOUTH.
MAIN CONCERN FOR THE SHORT TERM PERIOD IS STRATUS/FOG
POSSIBILITIES AND POSSIBLE LIGHT PRECIPITATION ACROSS THE NORTH.
THE 05 DEC 12 UTC NAM AND MESOSCALE MODELS HAVE BEEN HINTING AT A
BAND OF LIGHT PRECIPITATION MOVING ACROSS NORTHERN NORTH DAKOTA
LATE TONIGHT INTO SATURDAY MORNING. THE 18 UTC NAM HAS DISPLACED
THE PRECIPITATION FARTHER SOUTH...BUT RAP/HRRR HAVE BEEN PRETTY
CONSISTENT IN KEEPING VERY LIGHT PRECIPITATION ACROSS THE NORTH.
HAVE ADDED SOME SLIGHT CHANCE POPS NORTHWEST AND NORTH CENTRAL
LATER THIS EVENING INTO SATURDAY MORNING...TAPERING TO ONLY
FLURRIES AS PRECIPITATION MOVES FROM NORTH CENTRAL INTO NORTHEAST
ND. HAVE KEPT PRECIPITATION ALL SNOW AS IT LOOKS LIKE THE WARMER
TEMPERATURES ALOFT DO NOT ARRIVE UNTIL BEST FORCING HAS ALREADY
PASSED...THUS PRECIP SHOULD REMAIN ALL SNOW.
MESOSCALE MODELS CONTINUE TO SHOW INCREASING LOW LEVEL MOISTURE
ACROSS THE NORTH AND EAST THIS AFTERNOON AND THIS EVENING...THEN
POSSIBLY SHIFTING MORE TO THE SOUTHWEST LATER TONIGHT AS SOUTHEAST
FLOW KICKS IN ON THE BACK SIDE OF THE SURFACE HIGH. HAVE OPTED TO
MENTION PATCHY FOG TONIGHT AS RAP BUFR SOUNDINGS DO SUGGEST FOG
MOST AREAS. ALSO HAVE BUMPED UP SKY COVER LATE EVENING THROUGH
SATURDAY MORNING. TEMPERATURES ALSO TRICKY AS WE WILL LIKELY SEE A
QUICK DROP THIS EVENING EAST WITH RISING TEMPERATURES LATE.
PERHAPS A QUICK DROP CENTRAL/WEST WITH RISING TEMPERATURES LATE
EVENING INTO THE OVERNIGHT AND THEN DROPPING OFF BY MORNING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
SATURDAY NIGHT THROUGH SUNDAY NIGHT...AN UPPER LEVEL LOW/SHARP
TROUGH WITH AN ASSOCIATED SURFACE COLD FRONT WILL PUSH ACROSS
WESTERN AND CENTRAL NORTH DAKOTA SUNDAY INTO SUNDAY NIGHT. SOUTH TO
SOUTHWESTERLY FLOW AHEAD OF THIS SYSTEM WILL ALLOW FOR WARMING
THROUGH SUNDAY MORNING. THE H85 BAROCLINIC ZONE BEGINS TO PUSH
ACROSS THE FAR WEST BY 18Z AND THEN SHIFTS INTO CENTRAL NORTH DAKOTA
SUNDAY AFTERNOON/EVENING. STILL SOME THREAT OF A WINTRY MIX ACROSS
NORTHERN NORTH DAKOTA...BUT IT APPEARS THE BETTER CHANCE FOR
PRECIPITATION MAY OCCUR SUNDAY EVENING INTO SUNDAY NIGHT ACROSS
NORTHERN NORTH DAKOTA...ASSOCIATED WITH A WEAK/NARROW TROWAL PER GFS
H7-H5 EQUIVALENT POTENTIAL TEMPERATURE. AMOUNTS LOOK VERY
LIGHT...PERHAPS A TENTH OR TWO OF AN INCH OF SNOW. WEST TO NORTHWEST
WINDS INCREASE IN THE WEST DURING THE AFTERNOON WITH THE STRONGEST
WINDS NOT ARRIVING UNTIL SUNDAY NIGHT FOR CENTRAL NORTH DAKOTA.
EXPECT 20 TO 35MPH WINDS DEVELOPING BEHIND THIS SYSTEM. WITH LIMITED
SNOW SHOWERS AND QPF...AT THIS TIME HAVE NOT MENTIONED ANY BLOWING
SNOW.
MONDAY THROUGH FRIDAY...BRISK NORTHWEST WINDS CONTINUE DURING THE
DAY MONDAY BUT ABATE MONDAY EVENING. COLDER MONDAY AFTERNOON WITH
HIGHS 20 NORTHEAST TO MID 30S FAR SOUTHWEST. THEREAFTER A
PROGRESSIVE PATTERN ENSUES WITH NO SIGNIFICANT SHORTWAVES FORECAST
THROUGH THE REMAINDER OF THE LONG TERM PERIOD. A WARMING TREND IS
STILL IN THE FORECAST WITH HIGHS 35F TO 45F WEDNESDAY THROUGH
FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1242 AM CST SAT DEC 6 2014
IFR CIGS WILL CONTINUE OVER NORTH CENTRAL NORTH DAKOTA THROUGH
MUCH OF THE NIGHT...AFFECTING KMOT. ELSEWHERE VFR TO MVFR CIGS
CAN BE EXPECTED. PATCHY FOG MAY DEVELOP OVERNIGHT AT SOME OR ALL
TERMINALS...WITH KMOT/KJMS MOST LIKELY TO SEE FOG.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...TWH
LONG TERM...KS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1119 PM CST FRI DEC 5 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 304 PM CST FRI DEC 5 2014
ALTHOUGH VISIBILITY HAS IMPROVED...FOG CONTINUES TO RESIDE THROUGH
NORTHWEST IOWA THIS AFTERNOON...SO THE BIGGEST CHALLENGE TONIGHT
REMAINS HOW QUICKLY FOG ERODES AS DRIER AIR FILTERS IN BEHIND THE
SURFACE TROUGH PUSHING ACROSS THE REGION. WATCHING THE TRENDS
THROUGH THE AFTERNOON...VISIBILITIES HAVE QUICKLY IMPROVED AS THE
WINDS TRANSITIONED TO NORTHERLY BEHIND THE TROUGH AND THE DRIER AIR
DRAINED IN. USING THAT AND RAP 925 MB RH FIELDS WHICH HAVE ALSO
CORRELATED WELL WITH THE FOG...HAVE THE FOG LINGERING THROUGH
PORTIONS OF NORTHWEST IOWA THROUGH THE EVENING THEN SLOWLY ERODING
FROM THE NORTH AND WEST AS DRIER AIR TAKES OVER DURING THE NIGHT.
COLDER AIR WILL ALSO FILTER SOUTH OVERNIGHT...WITH LOWS BOTTOMING
OUT AROUND 10 THROUGH THE HIGHWAY 14 CORRIDOR TO THE UPPER TEENS
THROUGH THE MISSOURI RIVER VALLEY.
SURFACE HIGH PRESSURE SETTLES INTO THE REGION ON SATURDAY...SO
SHOULD SEE SOME SUN ALONG WITH RELATIVELY LIGHT WINDS DURING THE DAY
WITH A WEAK GRADIENT EXISTING ACROSS THE REGION. WITH THERMAL
PROFILES A LITTLE COOLER HIGHS WILL RANGE FROM THE LOWER 30S NORTH
TO UPPER 30S SOUTH.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 304 PM CST FRI DEC 5 2014
THE PRIMARY FORECAST CONCERNS IN THE MEDIUM AND SHORT RANGE CONTINUE
TO FOCUS ON LIGHT PRECIPITATION CHANCES SUNDAY AND WARMUP INTO
NEXT WEEK/WEEKEND.
SUNDAY...MODELS STILL ON TRACK BRINGING TWO PIECES OF SHORTWAVE
ENERGY INTO THE REGION LATE SATURDAY NIGHT AND INTO SUNDAY. THE
FIRST WAVE WILL LIFT NORTHWARD FROM THE SOUTHWESTERN US WITH THE
SECOND WAVE DIPPING SOUTHEAST FROM THE PACIFIC NORTHWEST.
AGAIN...MOISTURE REMAINS RATHER SHALLOW IN NATURE AS THESE WAVES
MOVE THROUGH BUT AM ANTICIPATING A NARROW CORRIDOR OF LIGHT FREEZING
RAIN/DRIZZLE DEVELOPING NEAR DAYBREAK ALONG AND WEST OF I-29. WHILE
THE ATMOSPHERIC PROFILE LACKS ICE CRYSTALS FOR MOST OF THE
EVENT...THERE COULD BE A BRIEF WINDOW OF SATURATION EARLY IN THE
AFTERNOON WHICH WOULD OWE TO SLEET INTRODUCTION ESPECIALLY IN THE NE
ZONES. THE PRECIPITATION SHOULD BE LIGHT ENOUGH TO AVOID ANY
MAJOR ICING CONCERNS...ESPECIALLY SINCE SFC TEMPERATURES WILL
CONTINUE TO RISE THROUGH THE MORNING AND SHOULD CLIMB ABOVE
FREEZING IN THE AFTERNOON.
NEXT WEEK...SLIGHT MODEL DIFFERENCES CONTINUE FOR MUCH OF NEXT WEEK
WITH BOTH MAJOR EXTENDED RANGE MODELS SHOWING INCREASED RIDGING
ACROSS THE CONUS INTO NEXT WEEKEND. TEMPERATURES WILL COOL SLIGHTLY
BEHIND SUNDAYS DEPARTING TROUGH...BUT STILL AVERAGE NEAR OR SLIGHTLY
ABOVE SEASONAL NORMALS. FAIRLY SUBSTANTIAL DIFFERENCES PERSIST IN
THE HANDLING OF SHORTWAVE ENERGY MOVING THROUGH THE PACIFIC
NORTHWEST ON MONDAY. ECMWF KEEPS THIS ENERGY WELL NORTH OF THE
CWA...MEANWHILE THE GFS PULLS THE WAVE THROUGH THE CENTRAL PLAINS.
THE END RESULTS COULD BE SUBSTANTIAL DIFFERENT FOR WEDNESDAY-
FRIDAY. SHOULD THE GFS SOLUTION VERIFY...THE RESULT WOULD BE
INCREASED CLOUD COVER...FOG...AND SLIGHTLY COOLER TEMPS IN THE
LOCAL AREA. ON THE FLIPSIDE...THE MORE AMPLIFIED ECMWF SOLN COULD
SUGGEST VERY WARM TEMPERATURES THURSDAY AND INTO THE WEEKEND. FOR
TODAY...PREFERENCES CONTINUE TO FALL TOWARDS THE ECMWF...BUT WILL
HEDGE A BIT TOWARDS THE OTHER CAMP OF SOLNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1119 PM CST FRI DEC 5 2014
MONITORING A QUICK END ON KSUX AREA WEBCAMS TO THE VLIFR AND IFR
CONDITIONS AROUND KSUX WHICH ARE EXPECTED TO BE OUT OF THE KSUX
AREA BY ISSUANCE OF THE 06Z TAFS. MOISTURE WILL KEEP THREAT OF
SOME MVFR VISIBILITIES AROUND THE KSUX AREA INTO EARLY MORNING
AS NORTHERLY WINDS DIMINISH. FOR KFSD...MORE LIKELY TO GET ONLY
A PERIOD OF SHALLOW VALLEY FOG...WITH DEEPER DRY LAYER ALOFT.
TOWARD THE END OF THE TAF PERIOD...MAY SEE RESURGENCE IN THE LIFR
CEILINGS AS FLOW TURNS TO THE SOUTHEAST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...DUX
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1011 PM MST FRI DEC 5 2014
.UPDATE...
ISSUED AT 725 PM MST FRI DEC 5 2014
STALLED LL BAROCLINIC ZONE ACROSS THE FAR NORTH WILL INTERACT
WITH A PASSING MID LEVEL IMPULSE THIS EVENING...POSSIBLY
SUPPORTING A FEW LIGHT SHOWERS ACROSS FAR NW SD. HAVE ADDED A
SLIGHT CHANCE FOR PRECIP THERE...OPTING FOR A WINTRY MIX GIVEN
WARM WEDGE ALOFT. OTHERWISE...SUFFICIENT LL MOISTURE AT THE SFC
MAY SUPPORT PATCHY AREAS OF FOG LATER TONIGHT ACROSS WESTERN SD.
HOWEVER...ENSUING SFC PRESSURE FALLS PER LEE SIDE TROUGHING WILL
SUPPORTING INCREASING LL FLOW...INCREASING TURBULENT MIX DOWN OF
DRY AIR. THIS WILL LIKELY LIMIT COVERAGE OF ANY FOG...ESP AWAY
FROM VALLEYS. HAVE TRIMMED DOWN FOG MENTION AND RELEGATED MENTION
TO PATCHY.
&&
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 207 PM MST FRI DEC 5 2014
UPPER LEVEL ANALYSIS SHOWS A RIDGE OVER THE WESTERN
CONUS...WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS. CANADIAN
SURFACE HIGH IS MOVING SOUTHWARD INTO MT/ND. SKIES ARE PARTLY
CLOUDY...WITH GENERALLY LIGHT WINDS AND TEMPS IN THE UPPER 30S AND
40S.
LIGHT WINDS WILL BECOME SOUTHEASTERLY TONIGHT AS THE SURFACE HIGH
CROSSES ND...BRINGING MOISTURE INTO THE AREA. SEVERAL MODELS ARE
STILL HINTING AT SOME FOG SETTING UP AROUND THE AREA. THE HRRR AND
RAP ARE SHOWING LOW CEILINGS ACROSS THE SD PLAINS DEVELOPING AFTER
MIDNIGHT...AND LATEST RUNS ALSO HAVE FOG WRAPPING AROUND THE
SOUTHERN HILLS INTO NORTHEAST WY. MEANWHILE THE NAM HAS THE BEST
CHANCES FOR FOG AROUND THE HILLS AND INTO NORTHEAST WY...NOT SO MUCH
ON THE SD PLAINS. THE NAM SEEMS TO BE OVERESTIMATING MOISTURE
LATELY...AND SINCE WINDS IN NORTHEAST WY LOOK A LITTLE STRONGER
OVERNIGHT...HAVE MORE UNCERTAINTY ABOUT FOG DEVELOPMENT THERE.
DECREASED AREAS OF FOG TO PATCHY ACROSS NORTHEAST WY...KEEPING AREAS
OF FOG JUST EAST OF THE HILLS. COULD ALSO BE SOME PATCHY FOG IN
SURROUNDING AREAS ACROSS THE SD PLAINS. AS THE SURFACE HIGH MOVES
SOUTHEAST OVERNIGHT...COLD AIR WILL ADVECT INTO THE EASTERN CWA.
LOWS WILL RANGE FROM THE TEENS ACROSS NORTH CENTRAL/NORTHWEST SD TO
THE UPPER 20S IN NORTHEAST WY.
SOUTHERLY WINDS WILL BECOME BREEZY BY LATE SATURDAY MORNING AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN THE HIGH PRESSURE TO THE EAST AND
THE INCOMING LOW. EXPECT FOG TO DISSIPATE BY MID-MORNING. THERE IS
SOME UNCERTAINTY WITH TEMPS ON SATURDAY...AS MODELS HAVE A 10-DEGREE
SPREAD FOR HIGHS IN SOME PLACES. WITH SOUTHERLY BOUNDARY-LAYER WINDS
AND WARM AIR ADVECTION...KEPT TEMPS MILD...IN THE MID 30S NORTH AND
EAST TO THE UPPER 40S FARTHER WEST. LOWS SATURDAY NIGHT WILL BE IN
THE 20S TO LOWER 30S.
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 207 PM MST FRI DEC 5 2014
MODELS ARE IN GOOD AGREEMENT DURING THE EXTENDED
PERIOD...WITH RELATIVELY HIGH PREDICTABILITY THROUGH AT LEAST
WEDNESDAY. IN THE MEAN...THERE WILL BE A LONG-WAVE TROUGH OFF THE
WEST COAST WITH A LONG-WAVE RIDGE NEAR THE CNTRL CONUS.
ON SUNDAY A SHORT-WAVE TROUGH WILL MOVE ACROSS THE FAR NRN PLAINS
AND THROUGH THE L/W RIDGE...BRINGING A COLD FRONT AND NORTHWEST WIND
SHIFT ACROSS THE CWA. THIS WILL BRING SCT SHRASN TO THE BLKHLS. ON
MONDAY THROUGH WEDNESDAY THE RIDGE REBOUNDS...BUT WITH A WEAK SHORT-
WAVE TROUGH SLOWLY MOVING ACROSS THE NRN PLAINS. THIS IS NOT
EXPECTED TO BRING ANY PRECIP TO THE CWA GIVEN THE LIMITED FORCING
FOR ASCENT AND LACK OF LOW- TO MID-LEVEL MOISTURE.
ON THURSDAY AND FRIDAY...THE LONG-WAVE TROUGH MOVES INTO THE ERN
HALF OF THE CONUS WITH SOUTHWEST FLOW ALOFT DEVELOPING ACROSS THE
CWA IN RESPONSE TO A DEEP UPPER LOW COMING ONSHORE NEAR CA. THE GFS
SEEMS A BIT AGGRESSIVE WITH THIS LOW...SO HAVE KEPT THE FORECAST DRY
THROUGH FRIDAY. NEVERTHELESS...THERE ARE INDICATIONS THAT A BIG
STORM COULD BE LOOMING ON THE HORIZON FOR LATE NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1010 PM MST FRI DEC 5 2014
VFR CONDITIONS EXPECTED THROUGH THE PERIOD MOST PLACES. INCREASED
BL MOISTURE WITH A PERIOD OF LIGHT WINDS AND CLEAR SKIES MAY
SUPPORT PATCHY/AREAS OF FOG TONIGHT. HOWEVER...INCREASING LL
SOUTHERLY FLOW AND LIMITED MOISTURE ADVECTION SHOULD LIMIT
COVERAGE OF ANY FOG/STRATUS. GIVEN LOW PROBS/CONFIDENCE HAVE
OPTED TO LEAVE OUT OF TERMINALS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JC
SHORT TERM...POJORLIE
LONG TERM...BUNKERS
AVIATION...JC
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1158 PM CST FRI DEC 5 2014
.AVIATION...
A COLD FRONT HAS MOVED THROUGH NORTH AND CENTRAL TEXAS AS OF
0550Z. NORTH TO NORTHEAST WINDS AROUND 10 KNOTS WILL PREVAIL
THROUGH THE PERIOD. MVFR STRATUS HAS MOVED INTO THE METROPLEX AND
WILL MOVE INTO WACO AROUND 09Z. CEILINGS MAY FALL INTO THE IFR
CATEGORY 10-15Z. THE BROKEN TO OVERCAST CLOUDS ARE EXPECTED TO
BECOME SCATTERED AROUND 18Z SATURDAY. MVFR CEILINGS SHOULD
DEVELOP AGAIN AROUND 06Z SUNDAY.
58
&&
.UPDATE...
COLD FRONT IS ABOUT HALFWAY THROUGH THE CWA THIS EVENING BUT MOST
OF THE SHOWER ACTIVITY HAS DIMINISHED AS UPPER TROUGH PULLS
FARTHER AWAY TO THE EAST. OUTSIDE OF AN ISOLATED SHOWER RIGHT
ALONG THE FRONT...MOST AREAS WILL NOT SEE ANY RAIN. LOWERED POPS
FOR THE REMAINDER OF THE EVENING AND CONFINED THEM TO A NARROW
BAND RIGHT ALONG THE FRONT OVER THE EASTERN COUNTIES.
OTHERWISE...ONLY SOME MINOR DOWNWARD TWEAKS IN LOW TEMPERATURES
WERE NEEDED ACROSS THE NORTH AND NORTHWEST COUNTIES.
DUNN
&&
.PREV DISCUSSION... /ISSUED 339 PM CST FRI DEC 5 2014/
FOR TODAY...THE ONLY SIGNIFICANT CHANGE TO THE FORECAST FROM THE
MORNING UPDATE WAS TO INCREASE POPS SLIGHTLY ALONG AND SOUTHEAST
OF THE FORECAST POSITION OF THE COLD FRONT ACROSS THE CWA THROUGH
TONIGHT. EARLY AFTERNOON RUNS OF THE HRRR CONSISTENTLY ADVERTISE A
SCATTERED LINE OF SHOWERS DEVELOPING ALONG THE LEADING EDGE OF THE
COLD FRONT AS IT MOVES ACROSS THE CWA. AT 20Z/2PM...THE SURFACE
OBSERVATIONS INDICATED THAT THE LEADING EDGE OF THE COLD FRONT WAS
LOCATED ALONG A LINE FROM ARDMORE TO BOWIE TO BRECKENRIDGE. EARLY
AFTERNOON VISIBLE SATELLITE IMAGERY SHOWED A THIN LINE OF CUMULUS
ORGANIZING ALONG THE FRONT...SUPPORTING THE HRRR FORECAST FOR
STRONGER LIFT AND BETTER RAIN SHOWER CHANCES IN THE IMMEDIATE
VICINITY OF THE FRONT.
DESPITE THE INCREASE IN RAIN CHANCES IN THE SHORT TERM
FORECAST...CONTINUE TO THINK CHANCES OF LIGHTNING ARE LOW. 19Z
AIRCRAFT SOUNDINGS FROM KDFW AND KDAL AIRPORTS CONTINUE TO SHOW
MID-LEVEL LAPSE RATES THAT ARE TOO STABLE TO SUPPORT FREE
CONVECTION. LAPSE RATES HAVE INCREASED A BIT FROM 12Z...LIKELY DUE
FROM DYNAMIC LIFT ASSOCIATED WITH A SHORTWAVE TROUGH LOCATED OVER
OKLAHOMA EARLY THIS AFTERNOON ACCORDING TO WATER VAPOR SATELLITE
IMAGERY. HOWEVER DUE TO THE POSITION OF THE SHORTWAVE
TROUGH...THINK THAT THE EFFECTS OF DYNAMIC LIFT ON OUR MID-LEVEL
LAPSE RATES HAVE ALREADY OCCURRED. AS A RESULT...LEFT
PRECIPITATION ALONG THE FRONT THUNDERSTORM FREE THROUGH TONIGHT.
WILL CERTAINLY CONTINUE TO MONITOR AIRCRAFT OBSERVATIONS THROUGH
THIS EVENING...AND WILL UPDATE THE FORECAST IF IT LOOKS LIKE
THUNDER IS BECOMING MORE LIKELY.
SATURDAY...THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE ENTIRE
FORECAST AREA BY SATURDAY MORNING...LEAVING COOLER AND MUCH DRIER
AIR IN PLACE ACROSS THE REGION. ALTHOUGH THE COLD FRONT DOES NOT
REPRESENT A STRONG CANADIAN AIRMASS...AFTER TODAY`S TEMPERATURES
IN THE MID TO UPPER 70S...IT WILL CERTAINLY BE NOTICEABLY COOLER
TOMORROW BEHIND THE FRONT. HIGHS ARE EXPECTED TO TOP OUT NEAR 60
DEGREES FOR MOST LOCATIONS...VERY CLOSE TO NORMAL HIGHS FOR THIS
TIME OF YEAR. BETWEEN LOW-LEVEL DRY AIR ADVECTION BEHIND THE FRONT
AND SHORTWAVE RIDGING ALOFT...MAINTAINED A DRY FORECAST FOR
SATURDAY.
SUNDAY...A RELATIVELY FAST MOVING SHORTWAVE TROUGH...CURRENTLY
LOCATED ABOUT 800 MILES WEST OF BAJA CALIFORNIA...IS EXPECTED TO
MOVE OVER THE SOUTHERN PLAINS SUNDAY AFTERNOON. WITH A LOW-LEVEL
COOL AIRMASS STILL IN PLACE ACROSS THE CWA BEHIND TODAY`S
FRONT...ALL MODEL GUIDANCE INDICATES THAT THIS SHORTWAVE TROUGH
WILL RESULT IN STRONG WARM AIR ADVECTION OVER THE CWA ON SUNDAY.
WARM AIR ADVECTION OVER THE COOL LOW-LEVEL AIRMASS DOES REPRESENT
PERSISTENT LIFT...HOWEVER PRECIPITATION PROSPECTS FOR THE REGION
LOOK VERY LIMITED AT THIS TIME. DESPITE NEARLY ALL MODELS SHOWING
THE PERSISTENT LIFT ON SUNDAY...THE PROSPECTS FOR MOISTURE RETURN
LOOK VERY LIMITED...AND FOCUSED ON LOCATIONS JUST WEST AND SOUTH
OF THE CWA. AS A RESULT...WENT AHEAD AND BUMPED POPS DOWN 10
PERCENT ACROSS THE ENTIRE AREA THROUGHOUT THE DAY ON SUNDAY.
THINK THAT OUR BEST CHANCES FOR LIGHT RAINFALL MAY BE WHEN THE
SHORTWAVE TROUGH MOVES DIRECTLY OVERHEAD SUNDAY AFTERNOON. MODELS
SHOW A BAND OF RELATIVELY STRONG MID-LEVEL FRONTOGENETIC FORCING
MOVING OVER THE CWA RIGHT OUT AHEAD OF THE SHORTWAVE ON SUNDAY.
THIS WILL LIKELY RESULT IN SOME ELEVATED PRECIPITATION...HOWEVER
THE LOW-LEVEL AIRMASS LOOKS DRY ENOUGH THAT MOST OF THIS SHOULD
EVAPORATE BEFORE REACHING THE SURFACE. AT ANY RATE...THE END
RESULT WAS THAT ISOLATED RAIN SHOWERS WERE INCLUDED IN THE
FORECAST EVEN WHERE POPS ARE AS LOW AS 10 PERCENT TO ACCOUNT FOR
THIS VIRGA/LIGHT RAIN POTENTIAL.
MONDAY INTO TUESDAY...IN GENERAL...A REINFORCING SHOT OF COOL AND
DRY AIR WILL BUILD INTO THE AREA BEHIND SUNDAY`S SHORTWAVE TROUGH
KEEPING US DRY ACROSS NORTH TEXAS FOR EARLY NEXT WEEK. THE LARGE
SCALE UPPER AIR PATTERN IS EXPECTED TO BE DOMINATED BY LARGE
TROUGHS OVER THE FAR EAST AND WEST COASTS...RESULTING IN BROAD
RIDGING OR NEARLY ZONAL FLOW OVER THE CENTRAL PORTION OF THE
COUNTRY. THIS PATTERN ALSO GENERALLY FAVORS DRY WEATHER FOR THE
CWA...HOWEVER PERSISTENT WESTERLY FLOW ALOFT OVER THE CONUS
ROCKIES WILL RESULT IN LEE-SIDE TROUGHING INCREASING IN INTENSITY
THROUGHOUT THE WEEK. WITH LEE-SIDE TROUGHING DEVELOPING AND A COOL
AIRMASS IN PLACE...WE WILL ONCE AGAIN HAVE A SITUATION WHERE WE
HAVE SOUTHERLY FLOW ALOFT IMPINGING ON A COOL LOW-LEVEL AIRMASS
NEAR THE SURFACE. THIS WILL RESULT IN PERSISTENT...ALBEIT
WEAK...LIFT AND MOISTURE RETURN BY TUESDAY AFTERNOON. BACKED OFF
ON POPS A BIT FROM THE PREVIOUS FORECAST ON TUESDAY...HOWEVER
MAINTAINED SOME 20 POPS OVER THE FAR WESTERN CWA TUESDAY
AFTERNOON...NEAREST TO THE LOW-LEVEL MOISTURE RETURN CONSISTENTLY
ADVERTISED IN MEDIUM RANGE GUIDANCE.
WEDNESDAY...MODELS ADVERTISE THAT THE UPPER LEVEL PATTERN WILL
AMPLIFY WITH RIDGING BUILDING OVER THE CONUS ROCKIES IN RESPONSE
TO A STRONG UPPER TROUGH BUILDING EASTWARD...FARTHER ON SHORE THE
WESTERN CONUS COAST. THIS RESULTS IN NORTHWEST FLOW ALOFT OVER THE
REGION ON WEDNESDAY...IN WHICH MODELS HAVE BEEN CONSISTENTLY
SENDING A STRONG BUT COMPACT SHORTWAVE TROUGH SOUTHEAST THROUGH
THE CWA OVER THE PAST COUPLE OF DAYS. THIS TROUGH IS EXPECTED TO
REMAIN WELL NORTH OF NORTH TEXAS...BUT SHOULD HELP SPREAD SOME OF
THE MOISTURE RETURN FROM WEST TEXAS EASTWARD OVER THE CWA ON
WEDNESDAY. IF MOISTURE DOES SPREAD EAST AS ADVERTISED AND LOW-
LEVEL WARM AIR ADVECTION AND ISENTROPIC LIFT CONTINUES... LIGHT
RAIN SHOWERS WILL LIKELY SPREAD ACROSS THE ENTIRE CWA ON
WEDNESDAY. BECAUSE LIFT IS EXPECTED TO REMAIN WEAK...RAIN SHOWERS
SHOULD BE SPOTTY/HIT-AND-MISS ON WEDNESDAY.
THURSDAY AND FRIDAY...MODELS INDICATE THAT LOW-LEVEL WARM AIR
ADVECTION PERSISTS...HOWEVER MODELS ARE ALSO BRINGING THE UPPER
LEVEL RIDGE OUT FROM THE CONUS ROCKIES AND OVER THE GREAT PLAINS
FOR THE LATTER PART OF THE WEEK. DESPITE PERSISTENT LOW-LEVEL
LIFT...WILL FAVOR THE UPPER LEVEL RIDGING IN THIS FORECAST AND
KEEP THURSDAY AND FRIDAY DRY FOR NOW AS MID AND UPPER LEVEL
FORCING SHOULD BE DOMINATED BY SUBSIDENCE.
NEXT WEEKEND...MODELS ARE DEFINITELY STRUGGLING WITH RUN TO RUN
AND MODEL TO MODEL CONSISTENCY WITH REGARDS TO THE EVOLUTION OF
THE STRONG WEST COAST UPPER TROUGH. HOWEVER...MODELS HAVE BEEN
CONSISTENTLY BRINGING THIS TROUGH OVER THE PLAINS NEXT
WEEKEND...WHICH MAY RESULT IN SOME DECENT RAIN CHANCES FOR THE
REGION. THIS IS CURRENTLY BEYOND THE VALID FORECAST PERIOD...BUT
IT IS A SYSTEM THAT WE WILL BE KEEPING A CLOSE EYE ON IN THE
COMING DAYS.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 49 61 44 57 43 / 5 5 5 10 10
WACO, TX 51 63 46 57 43 / 10 10 10 20 20
PARIS, TX 49 60 42 56 39 / 20 10 5 10 10
DENTON, TX 45 60 42 56 41 / 5 5 5 10 5
MCKINNEY, TX 45 60 42 57 40 / 5 5 5 10 10
DALLAS, TX 50 61 45 56 44 / 5 5 5 10 10
TERRELL, TX 49 62 44 58 40 / 10 5 5 10 10
CORSICANA, TX 52 63 45 59 43 / 20 10 10 20 20
TEMPLE, TX 51 64 46 58 44 / 10 10 10 20 20
MINERAL WELLS, TX 45 60 42 56 42 / 0 5 10 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/91
AREA FORECAST DISCUSSION
NWS PORTLAND OR
851 PM PST FRI DEC 5 2014
.SYNOPSIS...THE FIRST IN A SERIES OF WETTER...WARMER...BREEZIER STORM
SYSTEMS WAS MOVING INTO NORTHWEST OREGON AND SOUTHWEST WASHINGTON
TONIGHT...WITH SOME LINGERING COLD AIR IN THE UPPER HOOD RIVER VALLEY
AND SHELTERED VALLEYS OF THE SOUTH WASHINGTON CASCADES.
HOWEVER...TEMPERATURES SHOULD MODERATE AS THE FAIRLY STRONG FRONT
MOVES THROUGH LATE TONIGHT AND EARLY SATURDAY. SNOW LEVELS WILL LOWER
TO AROUND 4500 FEET LATE TONIGHT AND SATURDAY MORNING IN THE
CASCADES...WITH THE BEST CHANCE OF DECENT ACCUMULATING SNOWS IN THE
SOUTH WASHINGTON CASCADES. A BRIEF UPPER RIDGE WILL BRING DRYING BUT
ALSO SOME VALLEY FOG SATURDAY NIGHT AND SUNDAY. THE NEXT SYSTEM MOVES
IN SUNDAY NIGHT AND MONDAY...WITH A SERIES OF WETTER AND WINDIER
SYSTEMS MONDAY NIGHT INTO THURSDAY.
&&
.SHORT TERM...TONIGHT THROUGH MONDAY...THE FIRST IN A SERIES OF
DECENT FRONTS WAS SPREADING IN FROM THE SOUTHWEST THIS EVENING...AND
WILL COVER THE AREA OVERNIGHT. STRONG EAST WINDS THROUGH THE GORGE
AND THE RESULTANT COLD AIR DAMMING ALONG THE EAST SLOPES OF THE
CASCADES INDICATES ONE MORE ROUND OF SOME FREEZING RAIN IN THE UPPER
HOOD RIVER VALLEY...THE EASTERN VALLEYS OF SKAMANIA COUNTY...AND
POSSIBLY EVEN NEAR HOOD RIVER AND THE EAST SLOPES OF MOUNT HOOD. THE
FRONT MOVES THROUGH BY 12Z AND THE MODELS INDICATE THE AIR MASS
SHOULD MODERATE AROUND THAT TIME WITH A DECREASING CHANCE OF FREEZING
RAIN.
HOWEVER...THERE IS A CIRCULATION CENTER ALONG THE FRONT ASSOCIATED
WITH THE MAIN UPPER LEVEL VORTICITY THAT MOVES THROUGH BEHIND THE
FRONT LATE TONIGHT AND SATURDAY MORNING. THIS SHOULD BRING MORE
SHOWERS TO THE AREA...AND POSSIBLY EVEN A THUNDERSTORM. THE MODELS
ARE FOCUSING THE MAIN POST FRONTAL BAND OF PRECIPITATION SATURDAY TO
BE LOCATED FROM THE CENTRAL OREGON COAST RANGE TO THE SOUTH
WASHINGTON CASCADES. QPF LATE TONIGHT AND SATURDAY MORNING IN THE
SOUTH WASHINGTON CASCADES SUPPORT SNOW ADVISORY TYPE SNOW AMOUNTS...
PERHAPS 4 TO 8 INCHES. HAVE THUS CONVERTED THE FREEZING RAIN ADVISORY
FOR THE SOUTH WASHINGTON CASCADES TO A WINTER WEATHER ADVISORY FOR
FREEZING RAIN AND THEN SNOW TO REFLECT THIS TRANSITION. HAVE KEPT THE
FREEZING RAIN ADVISORY FOR THE UPPER HOOD RIVER VALLEY...AND WILL
NEED TO MONITOR WHETHER IT GETS COLD ENOUGH NEAR HOOD RIVER TO GET
ANY FREEZING RAIN THAT REQUIRES AN ADVISORY THERE LATER TONIGHT.
THE SHOWERS SHOULD EASE SATURDAY AFTERNOON AS THE ONSHORE FLOW BEHIND
THE DEPARTING SYSTEM WEAKENS...THEN AN UPPER RIDGE BRIEFLY BUILDS
INTO THE PACIFIC NORTHWEST SATURDAY NIGHT AND SUNDAY FOR DRYING. BUT
THIS WILL LIKELY LEAD TO AREAS OF FOG DEVELOPING SATURDAY NIGHT AND
CONTINUING THROUGH AT LEAST SUNDAY MORNING AND POSSIBLY INTO THE
AFTERNOON...ESPECIALLY IN AREAS AWAY FROM THE GORGE.
THE NEXT SYSTEM IS EXPECTED TO APPROACH AGAIN FROM THE SOUTHWEST LATE
SUNDAY BUT MAINLY IMPACT THE AREA SUNDAY NIGHT INTO MONDAY. THIS
SYSTEM SHOULD GIVE US ANOTHER SHOT OF PRECIPITATION...BUT IT APPEARS
TO WEAKEN A BIT AFTER HITTING NORTHERN CALIFORNIA FIRST AND THEN
LIFTING NORTHWARD THROUGH OREGON. THE NEXT SERIES OF MUCH
STRONGER...WETTER...AND WINDY SYSTEMS APPEARS HEADED TO OUR AREA IN
THE MID WEEK PERIOD NEXT WEEK. TOLLESON
.LONG TERM...TUESDAY THROUGH FRIDAY...NOT MUCH CHANGE TO THE OVERALL
THINKING FOR THE EXTENDED FORECAST PERIOD. POPS WERE HELD ABOVE CLIMO
FOR MUCH OF THE FORECAST. A MORE COMPACT AND ENERGETIC STORM SYSTEM
LOOKS LIKE IT WILL IMPACT THE AREA ON TUESDAY...BUT WHETHER OR NOT
HIGH WINDS WILL SURFACE ON THE COAST REMAINS UNCERTAIN THIS FAR OUT.
A SECOND LOW PRESSURE SYSTEM DEVELOPING IN THE NORTHEAST PACIFIC WILL
SEND ANOTHER FRONT INTO THE REGION TOWARDS MIDWEEK...BUT AS THE UPPER
LEVEL JET PLOWS SOUTH OF THE REGION...THE FRONT WILL PIVOT MORE
LONGITUDINALLY AS IT PUSHES THROUGH THE REGION. THIS SHOULD ACT TO
HELP QPF TOTALS IN THE VALLEY...BUT PERHAPS CUT DOWN ON THE RAIN
TOTALS IN THE COAST RANGE AND CASCADES...AND HELP EASE ANY FLOOD
CONCERNS. ONCE THIS FRONT PUSHES THROUGH THE REGION...SNOW LEVELS
SHOULD LOWER AND ADDITIONAL ONSHORE FLOW SHOULD BRING PERIODS OF
SHOWERS TO THE AREA...LIKELY IN THE FORM OF SNOW ABOVE 4000 TO 5000
FT. HOWEVER...WITH THE MAIN JET AND UPPER LEVEL SUPPORT DIGGING WELL
TO OUR SOUTH...BIG MOUNTAIN SNOWS APPEAR UNLIKELY. /NEUMAN
&&
.AVIATION...IFR FOG AND STRATUS HAVE PERSISTED INTO THIS EVENING FOR
THE SOUTHERN WILLAMETTE VALLEY. OTHERWISE CONDITIONS ARE MOSTLY VFR
ACROSS THE REGION AT CURRENT. HOWEVER...RAIN IS INCREASING FROM THE
SW IN ASSOCIATION WITH AN APPROACHING PACIFIC FRONTAL SYSTEM. EXPECT
A PERIOD OF MVFR CONDITIONS WITH A FEW POCKETS OF IFR AS THE MODERATE
RAIN BAND MOVES THROUGH LATER THIS EVENING AND OVERNIGHT. THE MAIN
RAIN BAND SHOULD BE THROUGH BY 12Z...WITH CONDITIONS GRADUALLY
IMPROVING THEREAFTER. THERE WILL BE PLENTY OF SHOWERS REMAINING
THROUGH TOMORROW AFTERNOON...ESPECIALLY FURTHER NORTH AND ALONG THE
COAST. THERE MAY BE PERIODS OF MVFR IN ANY HEAVIER SHOWERS THROUGH
ABOUT MIDDAY. THEN EXPECT MOSTLY VFR CONDITIONS FOR THE AFTERNOON.
PARTIALLY CLEARING SKIES SHOULD ALLOW FOG TO BEGIN FORMING BY LATER
TOMORROW EVENING.
GUSTY EASTERLY WINDS THROUGH THE COLUMBIA RIVER GORGE INTO KTTD
SHOULD BEGIN TO EASE AFTER MIDNIGHT.
KPDX AND APPROACHES...A BAND OF MODERATE RAIN WILL MOVE THROUGH THE
TERMINAL LATER THIS EVENING AND OVERNIGHT. EXPECT A PERIOD OF MVFR
CONDITIONS DURING THIS TIME. THE RAIN BAND MOVES THROUGH BY 11Z OR
12Z. SHOWERS CONTINUE MUCH OF THE DAY...WITH MVFR CONDITIONS POSSIBLE
THROUGH THE MORNING DURING ANY HEAVIER SHOWERS. PYLE
&&
.MARINE...A PACIFIC FRONTAL SYSTEM WILL MOVE THROUGH THE WATERS
TONIGHT...BRINGING A PERIOD OF SOLID SMALL CRAFT ADVISORY WINDS AND
CHOPPY SEAS. WINDS WILL GRADUALLY PICK UP OVER THE NEXT SEVERAL
HOURS...WITH THE STRONGEST WINDS EXPECTED AFTER MIDNIGHT AS THE
SURFACE TROUGH MOVES THROUGH THE WATERS. THE LATEST FCST MODELS
CONTINUE TO INDICATE THAT A FEW LOW END GALE FORCE GUSTS ARE POSSIBLE
OVER THE NEAR SHORE WATERS AND RIGHT ALONG THE COAST. HOWEVER...DO
NOT THINK THEY WILL BE FREQUENT ENOUGH TO JUSTIFY A GALE WARNING.
WITH THE INCREASING WINDS...EXPECT SHORT PERIOD FRESHLY GENERATED
SWELL TO CREATE CHOPPY CONDITIONS ON THE WATERS. DECIDED TO ISSUE A
SMALL CRAFT ADVISORY FOR SEAS WITH WAVE HEIGHTS EXPECTED TO BUILD
INTO THE 8 TO 10 FT RANGE WITH PERIODS OF 8 OR 9 SEC.
THE SURFACE TROUGH SHOULD PUSH ONSHORE BETWEEN 12Z AND 15Z...AFTER
WHICH WINDS WILL SHIFT TO THE SW AND SUBSIDE SOMEWHAT. HOWEVER...LOW
END SMALL CRAFT ADVISORY WINDS MAY CONTINUE THROUGH MUCH OF THE
DAY...PARTICULARLY FURTHER SOUTH. THERE SHOULD BE A BIT OF A LULL IN
THE WINDS AND SEAS LATER TOMORROW AND TOMORROW NIGHT. HOWEVER A
STRONGER FRONT IS EXPECTED TO MOVE INTO THE WATERS SUN AND SUN
NIGHT...WITH GALE FORCE WINDS A POSSIBILITY SUN NIGHT.
ADDITIONAL MODERATE TO STRONG FRONTS ARE MODELED TO MOVE THROUGH THE
PAC NW WATERS EVERY 24 TO 36 HRS THROUGH THE FIRST HALF OF NEXT WEEK.
IT APPEARS THAT THERE WILL BE SEVERAL CHANCES FOR SOLID GALES...AND
POSSIBLY EVEN SOME LOW END GALES ALTHOUGH CONFIDENCE IN THIS IS LOW
AT THIS TIME. IN RESPONSE TO THIS SERIES OF FRONTS...THE ENP WAVE
GUIDANCE IS PUSHING SEAS INTO THE UPPER TEENS TO NEAR 20 FT BEGINNING
MON NIGHT AND REMAINING IN THIS GENERAL RANGE THROUGH MUCH OF THE
WEEK. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING RAIN ADVISORY UNTIL 10 AM PST SATURDAY FOR UPPER HOOD
RIVER VALLEY.
WA...WINTER WEATHER ADVISORY UNTIL NOON PST SATURDAY FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON PST SATURDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON PST SATURDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST SATURDAY FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
710 PM PST FRI DEC 5 2014
.SYNOPSIS...
A series of storm systems will bring a wintry mix of precipitation
to the Pacific Northwest through a good portion of the weekend.
Each day valley temperatures will warm a bit meaning a gradual
transition from freezing rain and snow to just plain rain. A
break in storm systems occurs Sunday but ends quickly with more
winter storms passing through as early as Sunday night and
continuing on through at least the early part of the next
workweek.
&&
.DISCUSSION...
Evening update: the forecast is generally on track, with newest
models continuing to bring the next batch of precipitation in from
the west tonight into Saturday. The chances tonight will be
largely near the Cascades, with the highest threat starting after
about 09Z (1 AM). Some light precipitation will also be possible
across the northern mountains of WA and ID tonight. Models then
blossom the precipitation across the remainder of eastern WA and
north ID between 4 AM and 1 PM Saturday, before things start to
wind down from the west Saturday night.
Some adjustments made to increase fog coverage from the previous
forecast, though it is expected to be largely patchy in fashion
and may still have opportunity to decrease from the southeast
overnight. Main area I added some patchy fog was toward the Blues
and L-C Valley, as well as out across the Basin into the the
Waterville Plateau. The fog is down to a half mile or so in spots,
such as near GEG and LWS, though it hasn`t been all that
consistently that low in LWS. I kept the fog going through the
night, but make it patchier in areas where it has been most dense
(i.e. western Spokane county and along the highway 2 corridor.
Later in the forecast, toward Saturday night into Sunday morning,
models suggest some low level moisture and southwest flow will
combine to bring a stratus and fog threat. It seems like a good
pattern for it. So the forecast was update to add this for a good
chunk of the basin/valley areas. Its coverage will be fine tuned
over the next day or so. /J. Cote`
&&
.AVIATION...
00Z TAFS: Widespread fog and low stratus will hang around much of
the region with MVFR/IFR conditions expected through tonight.
There is moderate confidence that flight conditions will improve
at the KLWS, KGEG, KSFF and KCOE TAF sites overnight due to
increased easterly flow that should bring in some drier air at
lower levels. These same locations could see sky conditions
scatter out, but confidence is low that this will occur due to how
moist the boundary layer is early this evening. A mid level cold
front will push across the region during the morning on Saturday.
This will result in an increasing chance for light rain at all TAF
sites with cigs degrading back into MVFR/IFR category. There is a
slight chance for freezing rain at KEAT through tonight into
Saturday morning, but there is some model discrepancy that
temperatures will be able to cool back to below freezing. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 37 32 37 31 38 / 10 90 20 0 10 30
Coeur d`Alene 31 35 33 36 31 38 / 10 90 40 0 10 30
Pullman 38 39 33 38 35 43 / 10 100 20 0 10 30
Lewiston 37 39 35 45 37 46 / 10 90 10 0 10 20
Colville 32 34 31 38 29 38 / 30 70 30 0 10 30
Sandpoint 29 34 32 37 29 36 / 10 90 50 10 0 30
Kellogg 34 35 33 38 30 37 / 10 100 50 0 0 30
Moses Lake 34 36 30 40 32 38 / 50 90 0 0 10 30
Wenatchee 31 35 30 39 32 39 / 80 80 0 0 20 30
Omak 30 34 28 33 29 36 / 60 80 0 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Air Stagnation Advisory until Noon PST Tuesday for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until Noon PST Saturday for East Slopes
Northern Cascades-Wenatchee Area.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
710 PM PST FRI DEC 5 2014
.SYNOPSIS...
A series of storm systems will bring a wintry mix of precipitation
to the Pacific Northwest through a good portion of the weekend.
Each day valley temperatures will warm a bit meaning a gradual
transition from freezing rain and snow to just plain rain. A
break in storm systems occurs Sunday but ends quickly with more
winter storms passing through as early as Sunday night and
continuing on through at least the early part of the next
workweek.
&&
.DISCUSSION...
Evening update: the forecast is generally on track, with newest
models continuing to bring the next batch of precipitation in from
the west tonight into Saturday. The chances tonight will be
largely near the Cascades, with the highest threat starting after
about 09Z (1 AM). Some light precipitation will also be possible
across the northern mountains of WA and ID tonight. Models then
blossom the precipitation across the remainder of eastern WA and
north ID between 4 AM and 1 PM Saturday, before things start to
wind down from the west Saturday night.
Some adjustments made to increase fog coverage from the previous
forecast, though it is expected to be largely patchy in fashion
and may still have opportunity to decrease from the southeast
overnight. Main area I added some patchy fog was toward the Blues
and L-C Valley, as well as out across the Basin into the the
Waterville Plateau. The fog is down to a half mile or so in spots,
such as near GEG and LWS, though it hasn`t been all that
consistently that low in LWS. I kept the fog going through the
night, but make it patchier in areas where it has been most dense
(i.e. western Spokane county and along the highway 2 corridor.
Later in the forecast, toward Saturday night into Sunday morning,
models suggest some low level moisture and southwest flow will
combine to bring a stratus and fog threat. It seems like a good
pattern for it. So the forecast was update to add this for a good
chunk of the basin/valley areas. Its coverage will be fine tuned
over the next day or so. /J. Cote`
&&
.AVIATION...
00Z TAFS: Widespread fog and low stratus will hang around much of
the region with MVFR/IFR conditions expected through tonight.
There is moderate confidence that flight conditions will improve
at the KLWS, KGEG, KSFF and KCOE TAF sites overnight due to
increased easterly flow that should bring in some drier air at
lower levels. These same locations could see sky conditions
scatter out, but confidence is low that this will occur due to how
moist the boundary layer is early this evening. A mid level cold
front will push across the region during the morning on Saturday.
This will result in an increasing chance for light rain at all TAF
sites with cigs degrading back into MVFR/IFR category. There is a
slight chance for freezing rain at KEAT through tonight into
Saturday morning, but there is some model discrepancy that
temperatures will be able to cool back to below freezing. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 37 32 37 31 38 / 10 90 20 0 10 30
Coeur d`Alene 31 35 33 36 31 38 / 10 90 40 0 10 30
Pullman 38 39 33 38 35 43 / 10 100 20 0 10 30
Lewiston 37 39 35 45 37 46 / 10 90 10 0 10 20
Colville 32 34 31 38 29 38 / 30 70 30 0 10 30
Sandpoint 29 34 32 37 29 36 / 10 90 50 10 0 30
Kellogg 34 35 33 38 30 37 / 10 100 50 0 0 30
Moses Lake 34 36 30 40 32 38 / 50 90 0 0 10 30
Wenatchee 31 35 30 39 32 39 / 80 80 0 0 20 30
Omak 30 34 28 33 29 36 / 60 80 0 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Air Stagnation Advisory until Noon PST Tuesday for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until Noon PST Saturday for East Slopes
Northern Cascades-Wenatchee Area.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
405 PM PST FRI DEC 5 2014
.SYNOPSIS...
A series of storm systems will bring a wintry mix of precipitation
to the Pacific Northwest through a good portion of the weekend.
Each day valley temperatures will warm a bit meaning a gradual
transition from freezing rain and snow to just plain rain. A
break in storm systems occurs Sunday but ends quickly with more
winter storms passing through as early as Sunday night and
continuing on through at least the early part of the next
workweek.
&&
.DISCUSSION...
Tonight: Conditions will dry out across the eastern and southern
third of the forecast area while the Cascades...Wenatchee
Area...and areas of the northern mountain deal with a messy wintry
mix.
Precipitation for much of today has been uneventful to say
the least with most midlevel circulations falling apart once they
cross into Chelan County. Regional radar indicates a line of
showers continuing to fill in from Kittitas County southward to
the central Oregon Cascades which are tracking north toward the
Hwy 97 corridor. It is uncertain whether these showers will
survive the trip into Chelan/Douglas Counties but HRRR continues
to hint at some showers during the 23-02z time-frame. Most
locations remain below freezing with a few exceptions. With
wetbulb effects and sunset approaching, it is unlikely any
location will remain above freezing. The showers moving through
the next few hours will not be a major player for freezing
rain.
Freezing rain advisories were extended to capture steady
light to moderate precipitation moving in after midnight and
continuing into Saturday morning. This is a much different setup
compared the last 48 hours which have proved much drier than
expected. This system will feature southeast flow in the lower
levels, moderate isentropic ascent, and rich moisture. So as far
as I am concerned, the precipitation will be certain...now the
temperatures will be a bigger wild card. Temperatures are
typically slow to warm with SE flow in the lower levels however
as the air mass moistens...it has no where to go but warmer. When
this transition occurs will be the challenge of the night.
Needless to say, travel is likely to be slick near the Cascades
and Wenatchee Area. Some light precip is possible in the Okanogan
Valley and Northern Mountains but amounts should be low and
concerns are lower.
One other travel concern looks to be localized along Hwy 2 between
Airway Heights and Davenport which is dense fog. There may be a
few other areas out there, but this looks to be the worse case via
a tour of CAMS and motorists should plan on visibilities near 1/4
mile at times. Temperatures remain near 32F for most locations
north of I-90 so there is also the potential for black ice
redeveloping tonight. Temperatures will not fall much from current
readings (maybe 1-2 degrees) and may even rise or remain steady
for much of the night so we are not expecting a hard freeze in any
locations. /sb
Saturday through Monday...High pressure will be over the Pacific
Northwest through Sunday before getting pushed off to the east
Sunday night. A couple of vigorous but fast moving short wave
disturbances will move through the ridge...the first on
Saturday...the second on Monday. These two waves will result in
more wet weather across the region through the short term.
Temperatures will be on the increase with warm air advection and
should be above normal through Monday.
*Precipitation: Yes more wet weather with chances of mixed
precipitation. The wave moving through the region on Saturday
will tap into fairly deep Pacific moisture and combine with
moderate to strong isentropic up-glide and orographic lift for
light to moderate precipitation. Precipitation will be on the
increase across the western zones around 12z and push across the
forecast area through the day. A cold front will follow quickly
behind. The front should eject into Montana late Saturday
afternoon. Low level southeast-south flow Saturday morning will
eliminate any Cascade shadowing for the lowers east slopes and
the deep basin. The flow will shift around to the southwest-west
by late Saturday afternoon as the front moves through the area.
Drying from the west should begin by late morning, with
precipitation lingering across the Panhandle through the evening
hours. Saturday night and Sunday the area will be in a dry
period, although fog and low clouds will be probable. The next
weak wave will run through the ridge on Monday. This wave does
not have the deep moisture tap nor the lifting mechanism of the
previous wave but will still result in some very light
precipitation Monday afternoon.
*Precipitation type: The valleys up against the Cascades have had
difficulty mixing out the cold air damned up against the
mountains. All indications are that precipitation may be as
freezing rain overnight, but should turn over to snow before
sunrise Saturday...especially for the Methow valley. Along the
the Columbia river and some of the northern valleys freezing rain
may also be a possibility for a few hours early Saturday morning,
but with increasing southerly flow these valleys should switch
over to rain. Precipitation amounts will range from around a
tenth or more for the lower elevations and a quarter to a third
of an inch for the mountains for the Saturday system. Snow
accumulation of 3-4 inches will be possible for the mountains
with possibly 1-2 inches for the Methow valley. For the Monday
system precipitation should be as valley rain and mountain snow,
with very light accumulations. Tobin
Monday night through Friday: Confidence is high that the region
will see a pattern shift through next week. Medium range models
are in good agreement that the longwave ridge of high pressure
will shift east into the Rookies and over the Northern Plains.
This will place the region in a more mild and wet weather pattern.
A pair of very moist low pressure systems will impact the region.
There is still some uncertainty with the timing of these two
systems. There is better agreement with the first system as models
show the region firmly under the warm sector Monday night into
Tuesday, and then the cold front sweeping through around Tuesday
afternoon or night. Models diverge considerably more with the
second weather system. The ECMWF is faster and shows a stronger
warm frontal passage Tuesday night into Wednesday morning. The GFS
is much slower with precip redeveloping Wednesday afternoon/evening.
Snow levels will be increasing with each of these weather systems.
A pocket of cold air looks to remain along the lee side of the
northern Cascades into the Okanogan Highlands through at least
Monday night. This will keep snow levels lower to between 2,000
and 3,000 feet. There is a chance for some wet snow in the upper
reaches of the Methow Valley, but confidence is low. All other
valley locations are expected to see rainfall. Moderate to heavy
rainfall amounts will be possible with P-wats +2 standard
deviations of normal and up to between 0.75-1.00 inches.
Temperatures will warm to above normal through mid week. The upper
level trough in the Gulf of Alaska looks to dig in across the
region late next week. This will result in an end to the warming
trend with temperatures dipping back closer to normal by Friday.
/SVH
&&
.AVIATION...
00Z TAFS: Widespread fog and low stratus will hang around much of
the region with MVFR/IFR conditions expected through tonight.
There is moderate confidence that flight conditions will improve
at the KLWS, KGEG, KSFF and KCOE TAF sites overnight due to
increased easterly flow that should bring in some drier air at
lower levels. These same locations could see sky conditions
scatter out, but confidence is low that this will occur due to how
moist the boundary layer is early this evening. A mid level cold
front will push across the region during the morning on Saturday.
This will result in an increasing chance for light rain at all TAF
sites with cigs degrading back into MVFR/IFR category. There is a
slight chance for freezing rain at KEAT through tonight into
Saturday morning, but there is some model discrepancy that
temperatures will be able to cool back to below freezing. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 37 32 37 31 39 / 10 90 20 0 10 30
Coeur d`Alene 31 35 33 36 31 39 / 10 90 40 0 10 30
Pullman 38 39 33 38 35 44 / 10 100 20 0 10 30
Lewiston 37 39 35 45 37 47 / 10 90 10 0 10 20
Colville 32 34 31 38 29 39 / 30 70 30 0 10 30
Sandpoint 29 34 32 37 29 36 / 10 90 50 10 0 30
Kellogg 34 35 33 38 30 38 / 10 100 50 0 0 30
Moses Lake 34 36 30 40 32 39 / 50 90 0 0 10 30
Wenatchee 31 35 30 39 32 39 / 80 80 0 0 20 30
Omak 30 34 28 33 29 36 / 60 80 0 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Air Stagnation Advisory until Noon PST Tuesday for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until Noon PST Saturday for East Slopes
Northern Cascades-Wenatchee Area.
&&
$$
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
940 AM CST Sat Dec 6 2014
.UPDATE...
ISSUED AT 939 AM CST SAT DEC 6 2014
Main concern for today is with cloud cover. Widespread stratus
covers the forecast area this morning, with ceilings east of I-57
managing to reach just above 1000 feet while they remain 500 feet
or less most areas west. This morning`s upper air sounding, plus
forecast soundings off the latest NAM and RAP models, show a
persistent inversion around 950 mb. There is some clearing that
has occurred over the northwest corner of Illinois, but visible
satellite loops showing only slow southern progress toward the
Quad Cities area. We`re in the time of year where low sun angle
makes it difficult to burn off the low clouds. Areas northwest of
Peoria most likely to see any sun this afternoon although there
will still be quite a few clouds around. The remainder of the CWA
should remain mainly cloudy.
Going forecast is in pretty good shape, and only required some
minor tweaks to incorporate current trends.
&&
.SHORT TERM...(Today)
ISSUED AT 323 AM CST SAT DEC 6 2014
The 08z/2am surface analysis has a 1015mb low in NC Kentucky moving
northeast along a stationary front. Rain showers on the NW flank of
the low are steadily progressing eastward out of our E-SE counties.
The back edge of precip should reach I-57 by 09z/3am and be
completely out of our IL counties by 13z/7am.
Despite dry air aloft flowing into Illinois on N-NW winds, a strong
subsidence inversion is indicated in all the short term models. That
will limit mixing of the dry air in to the low level moisture, and
work to keep clouds across our forecast area over the next 12 hours
if not well into tonight. The satellite images are showing a
clearing line progressing south toward IL across MN/WI, however,
that clearing should slow down with the intensification of the
inversion today. High temps will not climb appreciably under the
blanket of clouds, with readings topping out in the upper 30s toward
Galesburg and into the mid 40s toward Lawrenceville.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 323 AM CST SAT DEC 6 2014
High pressure continues to build into the region, although the
inversion remains and will likely see a continuation of the clouds
until the incredibly dry air aloft finally works its way down into
the higher RH in the llvls. This same dry air is also the deciding
factor in the next issue for the forecast with an approaching wave
Sun night/Monday. Prev models had more disagreement and the NAM
with a more southerly track for the wave was the outlier. With this
run, both the GFS and ECMWF starting to look a lot more like the
prev NAM. A small system developing into a larger upper trof late
in the weekend...with the look of two smaller waves bringing pops
back into the region. Although the GFS and the ECMWF are more
consistent with the prev NAM, the NAM is far more scarce with the
QPF. Keeping the forecast chances low for shower activity after
midnight Sun night/Monday... not only for lack of continuity from
run to run, but the considerable amount of dry air will take a while
to overcome. Not convinced the best lift will coincide with the
eventual saturation of the column.
Beyond Monday and its cold front, temps cool briefly, then moderate
back into the 40s for highs through the end of the week. 00z ECMWF
completely pulls back on a small disturbance Wed night/Thursday, and
should this trend continue, will likely pull the pops altogether out
of the next couple runs. For now, slight pops in the forecast to
cover a brief disturbance diving into the Great Lakes region on the
retreating edge of the larger scale 500 mb trof exiting out to the
northeast. This difference btwn the GFS and the European also
delineates the break point in the extended between any agreement in
the midst of a small pattern shift. Depth of the thickness ridge
going into day 7 and 8 will definitely result in some blend issues
going into next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 600 AM CST SAT DEC 6 2014
The cloud forecast will continue to be challenging over the next
24 hours, as a clearing line approaches central IL from the north.
However, the HRRR and NAM keep low clouds entrenched until later this
evening, while the GFS dissipates the low clouds this morning.
The HRRR does show the brief small area of break in the low clouds
that drifted across the area the last 6 hours, but it also indicates
that break will fill in and the clearing line will barely graze our NW
counties this afternoon, but not reach all the way to PIA.
The NAM/SREF/RAP forecast soundings all show a strong subsidence
inversion trapping the low level moisture across our terminal
sites today. So confidence is moderate in keeping low clouds in
place through the day. Ceiling heights will start out LIFR at
BMI/DEC and IFR at PIA/CMI/SPI. All ceilings should at least climb
to MVFR after 18z with heating of the day and lifting of the LCL.
We went with some clearing eventually developing tonight with
advancing high pressure and a deeper layer of dry air.
Winds will remain north today at 10-14kt and shift to northeast
tonight as they diminish below 10kt.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
821 AM CST SAT DEC 6 2014
.SHORT TERM...
409 AM CST
THROUGH SATURDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT AND INTO SATURDAY MORNING...THE MAIN
FORECAST CONCERNS WILL FOCUS ON SKY COVER AND THE IMPACT ON
TEMPERATURE TRENDS. LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY
INDICATE AN EXTENSIVE STRATUS DECK ACROSS THE REGION TRAPPED BENEATH
A STRONG INVERSION BASED AT AROUND 900MB. LATEST MODEL SOUNDINGS
INDICATE THAT THE INVERSION WILL HOLD FAST THROUGH THE REMAINDER OF
THE NIGHT AND MUCH OF THE DAY SATURDAY. ALSO...AS THE CENTER OF
HIGH PRESSURE MOVES ACROSS THE UPPER GREAT LAKES AND LOW PRESSURE
CONTINUES TO MOVE THROUGH THE OHIO VALLEY...WINDS WILL REMAIN NELY
OFF OF LAKE MICHIGAN...KEEPING MUCH OF NERN IL AND NWRN IN UNDER
CLOUD COVER A BIT LONGER THAN PREVIOUSLY ANTICIPATED. AS THE CENTER
OF THE HIGH SHIFTS TO THE EAST LATE THIS AFTERNOON AND THIS
EVENING...SFC FLOW WILL VEER MORE ELY-SELY...ALLOWING THE STRATUS
DECK TO FINALLY SCATTER OUT. NWRN PORTIONS OF THE CWA...GENERALLY
WEST OF THE FOX VALLEY COULD SCATTER OUT A BIT QUICKER THAN NERN
IL/NWRN IN AND LOCATION UNDER A FETCH OFF OF LAKE MICHIGAN. THIS
MAKES THE TEMPERATURE FORECAST FOR SATURDAY A BIT TRICKY AND WILL
ULTIMATELY DEPEND ON HOW QUICKLY CLOUD COVER CAN BREAK UP.
HOWEVER...THE REGION WILL STILL BE UNDER A COLD ADVECTIVE PATTERN AS
THE CENTER OF THE HIGH BUILDS ACROSS NRN MN AND LAKE SUPERIOR
TODAY...SO THE DIURNAL TEMPERATURE TREND SHOULD BE A LITTLE SLOWER
THAN...BUT AS THE CENTER OF THE HIGH SHIFT EAST OF LAKE SUPERIOR
LATE THIS AFTERNOON...THERE IS THE POTENTIAL FOR A LITTLE WARM
ADVECTION...AND WITH CLEARING SKIES...TEMPERATURES COULD SPIKE A FEW
DEGREES LATE THIS AFTERNOON...BEFORE THE SUN ANGLE GETS TOO LOW.
FOR THE REMAINDER OF SATURDAY NIGHT...EXPECT QUIET CONDITIONS AS SFC
RIDGING EXTENDS SOUTHWEST ACROSS THE AREA AND THROUGH THE MIDDLE
MISSISSIPPI VALLEY...WITH WINDS GRADUALLY VEERING TO SELY BY SUNDAY
MORNING. WITH DECREASING CLOUD COVER...DECREASING LOW LEVEL
MOISTURE...THE LOWER LEVELS SHOULD BE ABLE TO DECOUPLE OVERNIGHT
WITH WINDS DROPPING OFF AND RADIATIVE COOLING ALLOWING FOR
TEMPERATURES TO DROP INTO THE LOWER 20S FOR MOST AREAS...WITH THE
EXCEPTION OF THE URBAN HEAT ISLAND OF THE CHICAGO METRO AREA WHICH
SHOULD REMAIN IN THE UPPER 20S TO AROUND 30F.
KREIN
&&
.LONG TERM...
409 AM CST
SUNDAY THROUGH NEXT FRIDAY...
SUNDAY IS SHAPING UP TO BE A RELATIVELY PLEASANT DAY WITH SELY WINDS
PERSISTING THROUGH THE DAY AS THE HIGH MOVES INTO SERN CANADA AND A
LOW PRESSURE SYSTEM MOVES OUT OF THE SRN CANADIAN ROCKIES AND ACROSS
THE NRN PLAINS. THE EVOLUTION OF THIS SYSTEM HAS BEEN RELATIVELY
CONSISTENT OVER RECENT MODEL RUNS...IN TRACKING ACROSS THE NORTHERN
PLAINS AND DRAGGING A WEAK COLD FRONT AS IT TRACKS EWD. WINDS AHEAD
OF THE SYSTEM WILL VEER TO MORE SOUTHERLY ALLOWING SOME WARMER AIR
TO FILTER INTO THE REGION...BRINGING HIGHS IN THE UPPER 30S ACROSS
THE AREA. THE WEATHER PICTURE BECOMES A LITTLE MORE COMPLICATED AS
THE NEXT SYSTEM APPROACHES THE REGION. SINCE HIGH PRESSURE RIDGING
IS STILL EXPECTED TO EXTEND FROM NEW ENGLAND THROUGH THE LOWER
MISSISSIPPI VALLEY...THE GULF OF MEXICO WILL BE CUT OFF FROM THE
APPROACHING SYSTEM AND THE ONLY AVAILABLE MOISTURE FOR IT TO WORK
WITH WILL BE THE MEAGER AMOUNTS IN PLACE...PWATS AROUND A QUARTER OF
AN INCH AND WHAT MOISTURE IT CAN BRING AS A PACIFIC SOURCED MID
LEVEL SHORTWAVE. THROUGH THE EVENING ON SUNDAY...SFC TEMPERATURES
ARE EXPECTED TO DROP OFF INTO THE UPPER 20S TO THE LOWER 30S. MODEL
SOUNDING FOR SUNDAY NIGHT INTO MONDAY MORNING INDICATE WARMING ABOVE
THE BOUNDARY LAYER WITH TEMPS RISING TO 1-2C ABOVE A SUB-FREEZING
SFC LAYER. THE PCPN TYPE FORECAST FOR SUNDAY NIGHT INTO MONDAY
MORNING WILL BE COMPLICATED BY THE DEPTH AND DEGREE OF THE WARM
LAYER AND HOW FAR NORTH THE WARM LAYER CAN REACH. THE LATEST
GUIDANCE SUGGESTS THAT PCPN SHOULD START OUT AS A LITTLE LIGHT SNOW
OVER THE ROCKFORD AREA EARLY SUNDAY EVENING BEFORE THE WARM
INTRUSION REACHES INTO NCNTRL IL...WITH A TRANSITION OVER TO
FREEZING RAIN AND...PERHAPS...A LITTLE SLEET MIXING IN...WHICH WOULD
BE DEPENDENT ON THE DEPTH OF THE SURFACE-BASED FREEZING LAYER. AS
THE SYSTEM SLOWLY CROSSES THE AREA...MANY LOCATIONS COULD SEE A
PERIOD OF LIGHT FREEZING RAIN LATE SUNDAY NIGHT INTO EARLY MONDAY
MORNING...BEFORE CHANGING OVER TO ALL RAIN BY MIDDAY MONDAY. WITH
AVAILABLE DEEP LAYER MOISTURE STILL LIMITED...WITH PWATS ONLY OF A
HALF INCH OR SO...PCPN AMOUNTS SHOULD BE LIGHT...BUT EVEN A LIGHT
GLAZING OF FREEZING RAIN IN TIME FOR THE MONDAY MORNING RUSH HOURS
COULD CREATE TRAVEL DIFFICULTIES. HOWEVER...HIGH PRESSURE IS
EXPECTED TO QUICKLY BUILD ACROSS THE REGION FOLLOWING THE FRONTAL
PASSAGE...AND ANY PCPN SHOULD COME TO AN END BY LATE MONDAY
AFTERNOON OVER THE WRN PORTIONS OF THE CWA AND IN THE EARLY EVENING
FOR THE FAR SOUTHEAST. TEMPERATURES SHOULD BE HIGH ENOUGH DURG THE
LATE AFTERNOON HOURS THAT THE CHANCES FOR ANY FREEZING PCPN FOR THE
EVENING RUSH HOURS ARE LOW.
AS THE NEXT AREA OF HIGH PRESSURE BUILDS ACROSS THE REGION...A SHORT
PERIOD OF COOL...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY...WITH
HIGHS IN THE LOWER TO MIDDLE 30S AND OVERNIGHT LOWS IN THE UPPER
TEENS TO LOWER 20S. THE SYSTEM PASSING THROUGH THE AREA MONDAY
NIGHT IS EXPECTED TO DEVELOP INTO A DEEP UPPER LOW OVER THE MID
ATLANTIC REGION BY WEDNESDAY AND THEN SLOWLY MOVE UP THE EAST
COAST. BY WEDNESDAY NIGHT...THE DEEP UPPER LOW WILL MOVE OVER NEW
ENGLAND AS UPPER RIDING BUILDS FROM THE SRN ROCKIES THROUGH THE
UPPER MISSISSIPPI VALLEY. A WEAK SHORTWAVE IN THE NLY FLOW ALOFT
BETWEEN THESE TO LARGE SCALE SYSTEMS COULD BRING A BIT OF LIGHT SNOW
FOR WEDNESDAY NIGHT INTO THURSDAY...BUT ANY ASSOCIATED SNOWFALL
SHOULD BE LIGHT. TOWARDS THE END OF THE WEEK..THE UPPER RIDGING IS
EXPECTED TO BUILD ACROSS THE UPPER MIDWEST...BRINGING A WARMING
TREND FOR LATE NEXT WEEK...WITH TEMPS POSSIBLY REACHING THE LOWER TO
MIDDLE 40S BY NEXT FRIDAY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CIGS AROUND 1500 FT LIFTING THROUGH MIDDAY AND SCATTERING SOME
TIME LATE THIS AFTERNOON.
* N-NNE WINDS 12-15 KT GUSTING TO 20-25 KT AT TIMES THROUGH THE
AFTERNOON.
KMD
//DISCUSSION...UPDATED 12Z...
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
WHILE HIGH PRESSURE MOVES INTO THE UPPER MISSISSIPPI RIVER VALLEY.
STEADIER N TO NE WINDS HAVE SET UP IN THE 10-14 KT RANGE WITH
SPORADIC GUSTS ALSO APPEARING AT TIMES. GUSTS WILL LIKELY BECOME
MORE FREQUENT THIS AFTERNOON ESPECIALLY WHERE BREAKS CAN DEVELOP
IN THE CLOUD COVER. WINDS WILL GRADUALLY DIMINISH AND TURN
NORTHEAST THIS EVENING BEFORE SHIFTING SOUTHEAST TOWARD DAYBREAK
MONDAY.
CIGS WILL BE A CHALLENGE THROUGH THE MORNING. OBS SHOW BASE
HEIGHTS RANGING FROM 600-1100 FT ACROSS THE TERMINALS AND POINTS
UPSTREAM. A SLIGHT WIND COMPONENT OFF THE LAKE SEEMS TO BE KEEPING
BASES A LITTLE HIGHER WITHIN SEVERAL MILES INLAND OF THE SHORE
THANKS TO WARMER AIR OVER THE WATER. SATELLITE IMAGERY SHOWS A
WELL DEFINED BACK EDGE TO THE STRATUS ACROSS SOUTHERN WISCONSIN
WHICH IS MOVING SOUTHEAST. STRATUS IS ALSO EXTENSIVE ACROSS LAKE
MICHIGAN. THE BACK EDGE OF THIS STRATUS WILL LIKELY WORK ACROSS
MOST OF IF NOT ALL OF THE AREA THROUGH AROUND 16Z. HOWEVER...THERE
IS NOT SIGNIFICANT AMOUNTS OF DRY AIR WORKING INTO THE REGION SO
SCT-BKN STRATO CU MAY DEVELOP TOWARD MIDDAY....PROVIDED THE
CURRENT BAND DOES EXIT AND DOES NOT SLOW ITS SOUTHWARD PROGRESS.
IN OTHER WORDS THERE MAY BE A BREAK IN THE LOW CLOUDS BEFORE
DIURNAL CU DEVELOPS. ALSO...FLOW IN THE CLOUD LAYER WILL BE AIMED
FROM THE NORTHEAST RIGHT ACROSS THE LAKE SO LAKE PROCESSES MAY BE
SUFFICIENT TO KEEP STRATUS GOING AT LEAST WITHIN SEVERAL MILES OF
SHORE WELL INTO THE AFTERNOON. WILL GO AHEAD AND KEEP A LONGER
PERIOD OF STRATUS IN THE FORECAST FOR NOW WHICH COULD BE
PESSIMISTIC. OTHERWISE SKIES WILL CLEAR THIS EVENING IF THEY DO
NOT DO SO EARLIER. MORNING VSBY BETWEEN 2-5 SM WILL IMPROVE AS WE
GRADUALLY BEGIN TO WARM UP AFTER DAYBREAK.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN CLOUD BASES LIFTING THROUGH MIDDAY...BUT LOW
CONFIDENCE IN TIMING OF SCATTERING.
* HIGH CONFIDENCE IN WIND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
256 AM CST
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
EARLY THIS MORNING WITH STRONG HIGH PRESSURE MOVING EASTWARD ACROSS
THE EASTERN DAKOTAS. WINDS ARE STARTING TO INCREASE AS THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS TIGHTENS UP THROUGH THE MORNING.
AS A RESULT...EXPECT NORTH TO NORTHEAST WINDS TO RANGE FROM 20 TO 25
KT WITH GUSTS TO 30 KT ACROSS THE CENTRAL AND SOUTHERN PARTS OF THE
LAKE THIS MORNING/AFTERNOON WITH NORTHERN AREAS DIMINISHING THROUGH
THE AFTERNOON AS THE INFLUENCE OF THE HIGH ARRIVES. SPEEDS WILL
DIMINISH ACROSS THE LAKE THIS EVENING AND TONIGHT AS THE DIRECTION
TURNS EAST THEN SOUTHEAST AS THE HIGH SHIFTS TO THE EAST. WILL
CONTINUE WITH THE SMALL CRAFT ADVISORY INTO EARLY TONIGHT AS THE
LONG FETCH OF WIND WILL KEEP WAVES ELEVATED AFTER WINDS DIMINISH THIS
EVENING.
LOW PRESSURE WILL DEVELOP IN THE LEE OF THE NORTHERN ROCKIES SUNDAY
AND MOVE EASTWARD ALONG THE U.S./CANADIAN BORDER...CROSSING LAKE
SUPERIOR MONDAY EVENING. THE LOW WILL DRAG A COLD FRONT ACROSS THE
LAKE MONDAY EVENING. SOUTHERLY WINDS WILL INCREASE AHEAD OF THE LOW
SUNDAY AND SUNDAY NIGHT THEN SHIFT TO THE NORTHWEST BEHIND THE FRONT
MONDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD IN BEHIND THE LOW INTO
TUESDAY WITH A FAIRLY STRONG PUSH OF COLDER AIR AND A TIGHT PRESSURE
GRADIENT SUPPORTING GUSTY NORTH TO NORTHWEST WINDS. WINDS WILL
DIMINISH WEDNESDAY AS THE HIGH MOVES OVERHEAD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
610 AM CST Sat Dec 6 2014
.SHORT TERM...(Today)
ISSUED AT 323 AM CST SAT DEC 6 2014
The 08z/2am surface analysis has a 1015mb low in NC Kentucky moving
northeast along a stationary front. Rain showers on the NW flank of
the low are steadily progressing eastward out of our E-SE counties.
The back edge of precip should reach I-57 by 09z/3am and be
completely out of our IL counties by 13z/7am.
Despite dry air aloft flowing into Illinois on N-NW winds, a strong
subsidence inversion is indicated in all the short term models. That
will limit mixing of the dry air in to the low level moisture, and
work to keep clouds across our forecast area over the next 12 hours
if not well into tonight. The satellite images are showing a
clearing line progressing south toward IL across MN/WI, however,
that clearing should slow down with the intensification of the
inversion today. High temps will not climb appreciably under the
blanket of clouds, with readings topping out in the upper 30s toward
Galesburg and into the mid 40s toward Lawrenceville.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 323 AM CST SAT DEC 6 2014
High pressure continues to build into the region, although the
inversion remains and will likely see a continuation of the clouds
until the incredibly dry air aloft finally works its way down into
the higher RH in the llvls. This same dry air is also the deciding
factor in the next issue for the forecast with an approaching wave
Sun night/Monday. Prev models had more disagreement and the NAM
with a more southerly track for the wave was the outlier. With this
run, both the GFS and ECMWF starting to look a lot more like the
prev NAM. A small system developing into a larger upper trof late
in the weekend...with the look of two smaller waves bringing pops
back into the region. Although the GFS and the ECMWF are more
consistent with the prev NAM, the NAM is far more scarce with the
QPF. Keeping the forecast chances low for shower activity after
midnight Sun night/Monday... not only for lack of continuity from
run to run, but the considerable amount of dry air will take a while
to overcome. Not convinced the best lift will coincide with the
eventual saturation of the column.
Beyond Monday and its cold front, temps cool briefly, then moderate
back into the 40s for highs through the end of the week. 00z ECMWF
completely pulls back on a small disturbance Wed night/Thursday, and
should this trend continue, will likely pull the pops altogether out
of the next couple runs. For now, slight pops in the forecast to
cover a brief disturbance diving into the Great Lakes region on the
retreating edge of the larger scale 500 mb trof exiting out to the
northeast. This difference btwn the GFS and the European also
delineates the break point in the extended between any agreement in
the midst of a small pattern shift. Depth of the thickness ridge
going into day 7 and 8 will definitely result in some blend issues
going into next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 600 AM CST SAT DEC 6 2014
The cloud forecast will continue to be challenging over the next
24 hours, as a clearing line approaches central IL from the north.
However, the HRRR and NAM keep low clouds entrenched until later this
evening, while the GFS dissipates the low clouds this morning.
The HRRR does show the brief small area of break in the low clouds
that drifted across the area the last 6 hours, but it also indicates
that break will fill in and the clearing line will barely graze our NW
counties this afternoon, but not reach all the way to PIA.
The NAM/SREF/RAP forecast soundings all show a strong subsidence
inversion trapping the low level moisture across our terminal
sites today. So confidence is moderate in keeping low clouds in
place through the day. Ceiling heights will start out LIFR at
BMI/DEC and IFR at PIA/CMI/SPI. All ceilings should at least climb
to MVFR after 18z with heating of the day and lifting of the LCL.
We went with some clearing eventually developing tonight with
advancing high pressure and a deeper layer of dry air.
Winds will remain north today at 10-14kt and shift to northeast
tonight as they diminish below 10kt.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
948 AM EST SAT DEC 6 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 948 AM EST SAT DEC 6 2014
RAINFALL HAS EXITED THE FORECAST AREA FOR THE MOST PART...SO WILL
TAKE OUT POPS FOR THE REST OF THE DAY.
SHORT TERM MODELS SUGGEST LITTLE CHANCE OF ANY SIGNIFICANT CLEARING
TODAY. THICK CLOUD COVER COMBINED WITH LOW LEVEL COLD ADVECTION
SUGGESTS ONLY SUBTLE TEMPERATURE RISES FOR THE REST OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS.
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 061500Z KIND TAF UPDATE/...
ISSUED AT 921 AM EST SAT DEC 6 2014
A LARGE AREA OF MAINLY MVFR VISIBILITY RESTRICTIONS IN LIGHT FOG
CONTINUES ACROSS THE AREA...SO IT WILL PROBABLY BE SEVERAL MORE
HOURS BEFORE VISIBILITIES IMPROVE. WILL LOWER THE VISIBILITY
FORECAST INTO THE MVFR CATEGORY INTO THE EARLY AFTERNOON ON THE
UPDATE.
PREVIOUS DISCUSSION FOLLOWS.
IFR CONDITIONS WILL IMPROVE TO MVFR LATE THIS MORNING BEFORE
IMPROVING TO VFR OVERNIGHT.
SATELLITE CONTINUES TO SHOW EXTENSIVE CLOUDINESS ACROSS
INDIANA...ILLINOIS..MISSOURI AND IOWA. SURFACE ANALYSIS EARLY THIS
MORNING SHOWS LOW PRESSURE OVER EASTERN KENTUCKY...PULLING
NORTHEAST. RADAR SHOWS THE BACK EDGE OF PRECIP ALONG A LAF/HUF
LINE...PUSHING EAST.
SHOWERS ARE EXPECTED TO END BY 14Z AT ALL THE TAF SITES...HOWEVER
EXTENSIVE CLOUDS WILL REMAIN AS TIME HEIGHTS SHOW LINGERING LOWER
LEVEL MOISTURE THROUGH THE DAY AND THE PREVIOUSLY MENTIONED
UPSTREAM OBS WITH PLENTIFUL CLOUDINESS. THUS WILL CONTINUE MVFR
CIGS THROUGH MUCH OF THE DAY AS SURFACE HIGH PRESSURE SLOWLY WORKS IN.
RIDGING ALOFT FINALLY BEGINS TO WORK IN OVERNIGHT...AND WILL
TREND TOWARD VFR AT THAT TIME AS ANTICYCLONIC FLOW BECOMES PREDOMINATE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JAS
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...JP/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
921 AM EST SAT DEC 6 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /TODAY/...
ISSUED AT 356 AM EST SAT DEC 6 2014
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 061500Z KIND TAF UPDATE/...
ISSUED AT 921 AM EST SAT DEC 6 2014
A LARGE AREA OF MAINLY MVFR VISIBILITY RESTRICTIONS IN LIGHT FOG
CONTINUES ACROSS THE AREA...SO IT WILL PROBABLY BE SEVERAL MORE
HOURS BEFORE VISIBILITIES IMPROVE. WILL LOWER THE VISIBILITY
FORECAST INTO THE MVFR CATEGORY INTO THE EARLY AFTERNOON ON THE
UPDATE.
PREVIOUS DISCUSSION FOLLOWS.
IFR CONDITIONS WILL IMPROVE TO MVFR LATE THIS MORNING BEFORE
IMPROVING TO VFR OVERNIGHT.
SATELLITE CONTINUES TO SHOW EXTENSIVE CLOUDINESS ACROSS
INDIANA...ILLINOIS..MISSOURI AND IOWA. SURFACE ANALYSIS EARLY THIS
MORNING SHOWS LOW PRESSURE OVER EASTERN KENTUCKY...PULLING
NORTHEAST. RADAR SHOWS THE BACK EDGE OF PRECIP ALONG A LAF/HUF
LINE...PUSHING EAST.
SHOWERS ARE EXPECTED TO END BY 14Z AT ALL THE TAF SITES...HOWEVER
EXTENSIVE CLOUDS WILL REMAIN AS TIME HEIGHTS SHOW LINGERING LOWER
LEVEL MOISTURE THROUGH THE DAY AND THE PREVIOUSLY MENTIONED
UPSTREAM OBS WITH PLENTIFUL CLOUDINESS. THUS WILL CONTINUE MVFR
CIGS THROUGH MUCH OF THE DAY AS SURFACE HIGH PRESSURE SLOWLY WORKS IN.
RIDGING ALOFT FINALLY BEGINS TO WORK IN OVERNIGHT...AND WILL
TREND TOWARD VFR AT THAT TIME AS ANTICYCLONIC FLOW BECOMES PREDOMINATE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...JP/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
553 AM EST SAT DEC 6 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /TODAY/...
ISSUED AT 356 AM EST SAT DEC 6 2014
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 061200Z TAFS/...
ISSUED AT 529 AM EST SAT DEC 6 2014
IFR CONDITIONS WILL IMPROVE TO MVFR LATE THIS MORNING BEFORE
IMPROVING TO VFR OVERNIGHT.
SATELLITE CONTINUES TO SHOW EXTENSIVE CLOUDINESS ACROSS
INDIANA...ILLINOIS..MISSOURI AND IOWA. SURFACE ANALYSIS EARLY THIS
MORNING SHOWS LOW PRESSURE OVER EASTERN KENTUCKY...PULLING
NORTHEAST. RADAR SHOWS THE BACK EDGE OF PRECIP ALONG A LAF/HUF
LINE...PUSHING EAST.
SHOWERS ARE EXPECTED TO END BY 14Z AT ALL THE TAF SITES...HOWEVER
EXTENSIVE CLOUDS WILL REMAIN AS TIME HEIGHTS SHOW LINGERING LOWER
LEVEL MOISTURE THROUGH THE DAY AND THE PREVIOUSLY MENTIONED
UPSTREAM OBS WITH PLENTIFUL CLOUDINESS. THUS WILL CONTINUE MVFR
CIGS THROUGH MUCH OF THE DAY AS SURFACE HIGH PRESSURE SLOWLY WORKS IN.
RIDGING ALOFT FINALLY BEGINS TO WORK IN OVERNIGHT...AND WILL
TREND TOWARD VFR AT THAT TIME AS ANTICYCLONIC FLOW BECOMES PREDOMINATE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
917 AM CST SAT DEC 6 2014
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 915 AM CST SAT DEC 6 2014
WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE A WEAK UPPER LEVEL
RIDGE OF HIGH PRESSURE MOVING EASTWARD ACROSS THE WESTERN HIGH
PLAINS. MEANWHILE, AN UPPER LEVEL SHORTWAVE TROUGH IS PUSHING ASHORE
INTO SOUTHERN CALIFORNIA. NEAR THE SURFACE, A BROAD AREA OF HIGH
PRESSURE EXTENDS FROM THE UPPER MIDWEST SOUTHWEST INTO THE CENTRAL
PLAINS OF KANSAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 210 AM CST SAT DEC 6 2014
A SOUTHEASTERLY FLOW WILL DEVELOP BY LATE AFTERNOON AS A TROUGH
OF LOW PRESSURE BEGINS DEEPENS ALONG THE LEE OF THE ROCKIES AND A
SURFACE HIGH MOVES EAST TOWARDS THE MID MISSISSIPPI VALLEY. NAM,
RAP, NMM, AND ARW WERE ALL IN GOOD AGREEMENT WITH MORE HUMID AIR
IN LOWER LEVELS SPREADING BACK INTO SOUTHWEST KANSAS BY EARLY
TONIGHT AS THIS SOUTHEASTERLY FLOW DEVELOPS. BASED ON THE
AGREEMENT BETWEEN THE NEAR TERM MODELS AND EVEN RUN TO RUN
CONSISTENCY WILL EXPAND THE FOG POTENTIAL ACROSS ALL OF WESTERN
KANSAS TONIGHT BASED ON INCREASING LOW LEVEL MOISTURE AND UPSLOPE
FLOW. DENSE FOG ALSO MAY BE POSSIBLE AFTER MIDNIGHT EAST OF
HIGHWAY 283 GIVEN THE LIGHTER LOW LEVEL WINDS. DEPTH OF THIS LOW
LEVEL MOISTURE WILL STAY BELOW 3000FT AGL SO AM NOT ANTICIPATING
DRIZZLE DEVELOPMENT. HOWEVER WITH WARM AIR ADVECTION, MOISTURE,
AND WEAK ISENTROPIC LIFT DEVELOPING AHEAD OF AN UPPER LEVEL TROUGH
ACROSS SOUTH CENTRAL AND NORTH CENTRAL KANSAS WILL GO AHEAD AND
INSERT A CHANCE FOR SPRINKLES OR EVEN AN ISOLATED RAIN SHOWER. AS
FOR LOWS TONIGHT WENT ABOVE ALL GUIDANCE GIVEN THE MID TO UPPER 30
DEGREE DEWPOINTS RETURNING DURING THE OVERNIGHT HOURS.
AS FOR TODAY MID AND HIGH CLOUDS WILL INCREASE FROM THE WEST WITH
CLOUDY AFTERNOON SKIES LIKELY FOR ALL OF WESTERN KANSAS BY LATE
DAY. NET 24 HOUR TEMPERATURE TRENDS FROM 00Z SATURDAY TO 00Z
SUNDAY INDICATE AT 3 TO 5C COOL DOWN WHICH WOULD FAVOR THE WARMER
MAV/MOSGUIDE. HOWEVER GIVEN THE INCREASING CLOUD COVER WILL TREND
TOWARDS THE COOLER MET GUIDANCE FOR HIGHS WHICH ALSO WAS CLOSE TO
THE PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 407 AM CST SAT DEC 6 2014
A RELATIVELY CHALLENGING FORECAST LIES AHEAD IN THE 24 TO 60 HOUR
TIMEFRAME, PRIMARILY WITH RESPECT TO STRATUS DEVELOPMENT, FOG AND
POTENTIAL FOR VERY LIGHT SHOWERS. SUNDAY MORNING WILL LIKELY BEGIN
WITH WIDESPREAD LOW STRATUS AND AT LEAST SOME POTENTIAL FOR AREAS
OF...OR EVEN WIDESPREAD FOG EVEN IF NOT NECESSARILY DENSE.
BOUNDARY LAYER MOISTURE ADVECTION SHOULD BE DECREASING AS THE
SURFACE WINDS BECOME MORE SOUTHWEST TO WESTERLY AIDING IN DRYING
OUT THE CLOUD LAYER BY THE AFTERNOON. ADDITIONALLY, THE NMM/ARW
AND NAM INDICATE ANY LIGHT SHOWERS ASSOCIATED WITH THE MID LEVEL
WARM ADVECTION/ DEFORMATION AXIS SHOULD BE OVER BY NOON AS WELL.
ALTHOUGH SOME FOG DEVELOPMENT IS ALSO POSSIBLE ACROSS THE
EASTERNMOST COUNTIES MONDAY MORNING, THE BETTER BOUNDARY LAYER
MOISTURE WILL HAVE BEEN REMOVED WHICH WILL NOT FAVOR DEEPER
STRATUS DEVELOPMENT. THE PATTERN SUPPORTS FOG AND STRATUS BETTER
ONCE AGAIN BY MONDAY NIGHT AND TUESDAY MORNING WITH WHAT THE NAM
SHOWS AS AN UPTICK IN SURFACE LAYER MOISTURE ALONG A COLD FRONTAL
BOUNDARY. A CONVINCING SURFACE MOISTURE CONVERGENCE PATTERN
SOMEWHERE ROUGHLY FROM NORTHERN OKLAHOMA THROUGH EAST CENTRAL
COLORADO COULD RESULT.
DECENT AGREEMENT ACROSS MODEL DATA AND MOS EXISTS WITH RESPECT TO
THE DAILY HIGHS SUNDAY THROUGH TUESDAY, MAINLY IN THE MID 50S TO
AROUND 60 FAR WEST. TEMPERATURES WILL WARM FASTEST WEST OF HIGHWAY
283 AS THE STRATUS ERODES SUNDAY. TUESDAY MAY BRING COOLER
TEMPERATURES BEHIND THE COOL BOUNDARY ESPECIALLY IN LOCATIONS LIKE
HAYS AND STAFFORD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 559 AM CST SAT DEC 6 2014
IFR STRATUS WAS RAPIDLY ADVANCING WESTWARD ACROSS SOUTH CENTRAL
KANSAS THIS MORNING. THE HRRR HAD A REASIONABLE HANDLE ON THE
AREAL COVERAGE AND SPATIAL TRENDS. WITH SUCH UNCERTAINTY IN THE
IMPACTS FOR KDDC, WE`VE ADDED A TEMPO PERIOD FOR 500 FT CIELINGS
FOR THE NEXT 3 HOURS WHICH MIGHT BE AMENDED WITHIN THAT
TIMEFRAME. VFR CONDITIONS SHOULD THEN PREVAIL AT LEAST UNTIL THE
OVENIGHT HOURS WHEN STRATUS AND FOG MAY REDEVELOP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 37 58 34 / 0 0 20 0
GCK 48 38 59 29 / 0 0 10 0
EHA 53 41 62 35 / 0 0 10 0
LBL 51 39 59 31 / 0 0 10 0
HYS 45 34 54 35 / 0 0 20 0
P28 47 37 54 35 / 0 0 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
601 AM CST SAT DEC 6 2014
...UPDATED AVIATION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 210 AM CST SAT DEC 6 2014
A SOUTHEASTERLY FLOW WILL DEVELOP BY LATE AFTERNOON AS A TROUGH
OF LOW PRESSURE BEGINS DEEPENS ALONG THE LEE OF THE ROCKIES AND A
SURFACE HIGH MOVES EAST TOWARDS THE MID MISSISSIPPI VALLEY. NAM,
RAP, NMM, AND ARW WERE ALL IN GOOD AGREEMENT WITH MORE HUMID AIR
IN LOWER LEVELS SPREADING BACK INTO SOUTHWEST KANSAS BY EARLY
TONIGHT AS THIS SOUTHEASTERLY FLOW DEVELOPS. BASED ON THE
AGREEMENT BETWEEN THE NEAR TERM MODELS AND EVEN RUN TO RUN
CONSISTENCY WILL EXPAND THE FOG POTENTIAL ACROSS ALL OF WESTERN
KANSAS TONIGHT BASED ON INCREASING LOW LEVEL MOISTURE AND UPSLOPE
FLOW. DENSE FOG ALSO MAY BE POSSIBLE AFTER MIDNIGHT EAST OF
HIGHWAY 283 GIVEN THE LIGHTER LOW LEVEL WINDS. DEPTH OF THIS LOW
LEVEL MOISTURE WILL STAY BELOW 3000FT AGL SO AM NOT ANTICIPATING
DRIZZLE DEVELOPMENT. HOWEVER WITH WARM AIR ADVECTION, MOISTURE,
AND WEAK ISENTROPIC LIFT DEVELOPING AHEAD OF AN UPPER LEVEL TROUGH
ACROSS SOUTH CENTRAL AND NORTH CENTRAL KANSAS WILL GO AHEAD AND
INSERT A CHANCE FOR SPRINKLES OR EVEN AN ISOLATED RAIN SHOWER. AS
FOR LOWS TONIGHT WENT ABOVE ALL GUIDANCE GIVEN THE MID TO UPPER 30
DEGREE DEWPOINTS RETURNING DURING THE OVERNIGHT HOURS.
AS FOR TODAY MID AND HIGH CLOUDS WILL INCREASE FROM THE WEST WITH
CLOUDY AFTERNOON SKIES LIKELY FOR ALL OF WESTERN KANSAS BY LATE
DAY. NET 24 HOUR TEMPERATURE TRENDS FROM 00Z SATURDAY TO 00Z
SUNDAY INDICATE AT 3 TO 5C COOL DOWN WHICH WOULD FAVOR THE WARMER
MAV/MOSGUIDE. HOWEVER GIVEN THE INCREASING CLOUD COVER WILL TREND
TOWARDS THE COOLER MET GUIDANCE FOR HIGHS WHICH ALSO WAS CLOSE TO
THE PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 407 AM CST SAT DEC 6 2014
A RELATIVELY CHALLENGING FORECAST LIES AHEAD IN THE 24 TO 60 HOUR
TIMEFRAME, PRIMARILY WITH RESPECT TO STRATUS DEVELOPMENT, FOG AND
POTENTIAL FOR VERY LIGHT SHOWERS. SUNDAY MORNING WILL LIKELY BEGIN
WITH WIDESPREAD LOW STRATUS AND AT LEAST SOME POTENTIAL FOR AREAS
OF...OR EVEN WIDESPREAD FOG EVEN IF NOT NECESSARILY DENSE.
BOUNDARY LAYER MOISTURE ADVECTION SHOULD BE DECREASING AS THE
SURFACE WINDS BECOME MORE SOUTHWEST TO WESTERLY AIDING IN DRYING
OUT THE CLOUD LAYER BY THE AFTERNOON. ADDITIONALLY, THE NMM/ARW
AND NAM INDICATE ANY LIGHT SHOWERS ASSOCIATED WITH THE MID LEVEL
WARM ADVECTION/ DEFORMATION AXIS SHOULD BE OVER BY NOON AS WELL.
ALTHOUGH SOME FOG DEVELOPMENT IS ALSO POSSIBLE ACROSS THE
EASTERNMOST COUNTIES MONDAY MORNING, THE BETTER BOUNDARY LAYER
MOISTURE WILL HAVE BEEN REMOVED WHICH WILL NOT FAVOR DEEPER
STRATUS DEVELOPMENT. THE PATTERN SUPPORTS FOG AND STRATUS BETTER
ONCE AGAIN BY MONDAY NIGHT AND TUESDAY MORNING WITH WHAT THE NAM
SHOWS AS AN UPTICK IN SURFACE LAYER MOISTURE ALONG A COLD FRONTAL
BOUNDARY. A CONVINCING SURFACE MOISTURE CONVERGENCE PATTERN
SOMEWHERE ROUGHLY FROM NORTHERN OKLAHOMA THROUGH EAST CENTRAL
COLORADO COULD RESULT.
DECENT AGREEMENT ACROSS MODEL DATA AND MOS EXISTS WITH RESPECT TO
THE DAILY HIGHS SUNDAY THROUGH TUESDAY, MAINLY IN THE MID 50S TO
AROUND 60 FAR WEST. TEMPERATURES WILL WARM FASTEST WEST OF HIGHWAY
283 AS THE STRATUS ERODES SUNDAY. TUESDAY MAY BRING COOLER
TEMPERATURES BEHIND THE COOL BOUNDARY ESPECIALLY IN LOCATIONS LIKE
HAYS AND STAFFORD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 559 AM CST SAT DEC 6 2014
IFR STRATUS WAS RAPIDLY ADVANCING WESTWARD ACROSS SOUTH CENTRAL
KANSAS THIS MORNING. THE HRRR HAD A REASIONABLE HANDLE ON THE
AREAL COVERAGE AND SPATIAL TRENDS. WITH SUCH UNCERTAINTY IN THE
IMPACTS FOR KDDC, WE`VE ADDED A TEMPO PERIOD FOR 500 FT CIELINGS
FOR THE NEXT 3 HOURS WHICH MIGHT BE AMENDED WITHIN THAT
TIMEFRAME. VFR CONDITIONS SHOULD THEN PREVAIL AT LEAST UNTIL THE
OVENIGHT HOURS WHEN STRATUS AND FOG MAY REDEVELOP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 37 58 34 / 0 10 20 0
GCK 48 38 59 29 / 0 10 10 0
EHA 53 41 62 35 / 0 10 10 0
LBL 51 39 59 31 / 0 10 10 0
HYS 45 34 54 35 / 0 10 20 0
P28 47 37 54 35 / 10 10 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1018 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION INTO THIS EVENING. HIGH PRESSURE WILL
GIVE A DRY DAY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID MORNING UPDATE TO SLOW TIMING FOR RAIN TO END BASED ON LATEST
RADAR TRENDS AND INCOMING 12Z MODELS. STILL A CHANCE FOR SLEET TO
MIX IN FAR NORTH THIS AFTERNOON BUT NOTHING OF CONSEQUENCE. HOURLY
TEMPERATURES AND WINDS ADJUSTED TOWARD NEWEST LAMP GUIDANCE. WINDS
WERE INCREASED ESPECIALLY THIS EVENING AS SURFACE LOW PUSHES EAST.
PREVIOUS BELOW.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV THROUGH THAT
TROF IS CURRENTLY PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD
PROGRESS OF WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO
FOREGO PROBLEM CONTRIBUTION FOR THE UPR OH REGION. NEVERTHELESS...PCPN
CHCS WL INCRS ON MON NGT INTO TUESDAY AS ISENTROPIC LIFT...WARM
MOIST ADVCTN DVLPS ON THE ERN FLANKS OF THE HIGH AMPLITUDE ERN
CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A DEEP ERN CONUS TROF IS PROGGED TO PERSIST THRU ERLY INTO THE
WKEND AS COASTAL SFC LOW PRES TRACKS UP THE E COAST. FCST SNW
SHWR CHCS INTO WED NGT UNTIL THE LOW AND UPR SPPRT EXITS THE RGN.
A WK SRTWV IS PROGGED TO ROTATE THRU THE GT LKS ARND THE MAIN TROF
FRI THOUGH WITH BLDG SFC HIGH PRES UNDER THE TROF KEPT A DRY FCST.
BLO SEASONAL TEMPS SHOULD RTN TO NR AVG BY LT WK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
WDSPRD IFR/OCNL LIFR CONDS ARE EXPD TO CONT TDA AS UPR OH VLY LOW
PRES BRINGS RAIN TO THE RGN. THE EXCEPTION IS MGW AND LBE WHERE
OCNL MVFR IS EXPD ERLY...WITH CONDS DCRG TO IFR BY MID TO LT MRNG
AS MORE FAVORABLE LLVL MOISTURE ADVECTS OVR THOSE SITES. INCRG
NRLY WNDS AND COND IMPROVEMENT TO LOW END MVFR ARE EXPD BY THIS
EVE AS THE SFC LOW SHIFTS E AND RAIN TAPERS OFF...WITH SKIES
EVENTUALLY SCT OUT TWD SUNRISE SUN MRNG.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RSTRNS ARE EXPD MON NGT THRU WED AS LOW PRES BRINGS SNW SHWRS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
638 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION TODAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NO MAJOR CHANGES WERE NEEDED FOR THE PRE DAWN UPDATE AS LOW PRES
MOVG UP THE OHIO VALLEY WL MAINTAIN RAIN ACROSS THE REGION INTO
THE AFTERNOON.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV THROUGH THAT
TROF IS CURRENTLY PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD
PROGRESS OF WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO
FOREGO PROBLEM CONTRIBUTION FOR THE UPR OH REGION. NEVERTHELESS...PCPN
CHCS WL INCRS ON MON NGT INTO TUESDAY AS ISENTROPIC LIFT...WARM
MOIST ADVCTN DVLPS ON THE ERN FLANKS OF THE HIGH AMPLITUDE ERN
CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A DEEP ERN CONUS TROF IS PROGGED TO PERSIST THRU ERLY INTO THE
WKEND AS COASTAL SFC LOW PRES TRACKS UP THE E COAST. FCST SNW
SHWR CHCS INTO WED NGT UNTIL THE LOW AND UPR SPPRT EXITS THE RGN.
A WK SRTWV IS PROGGED TO ROTATE THRU THE GT LKS ARND THE MAIN TROF
FRI THOUGH WITH BLDG SFC HIGH PRES UNDER THE TROF KEPT A DRY FCST.
BLO SEASONAL TEMPS SHOULD RTN TO NR AVG BY LT WK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
WDSPRD IFR/OCNL LIFR CONDS ARE EXPD TO CONT TDA AS UPR OH VLY LOW
PRES BRINGS RAIN TO THE RGN. THE EXCEPTION IS MGW AND LBE WHERE
OCNL MVFR IS EXPD ERLY...WITH CONDS DCRG TO IFR BY MID TO LT MRNG
AS MORE FAVORABLE LLVL MOISTURE ADVECTS OVR THOSE SITES. INCRG
NRLY WNDS AND COND IMPROVEMENT TO LOW END MVFR ARE EXPD BY THIS
EVE AS THE SFC LOW SHIFTS E AND RAIN TAPERS OFF...WITH SKIES
EVENTUALLY SCT OUT TWD SUNRISE SUN MRNG.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RSTRNS ARE EXPD MON NGT THRU WED AS LOW PRES BRINGS SNW SHWRS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/07
AREA FORECAST DISCUSSION
NWS BUFFALO NY
705 AM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE PASSING TO THE SOUTH OF THE REGION WILL BRING RAIN
WHICH WILL TAPER OFF FROM WEST TO EAST THIS AFTERNOON. HIGH PRESSURE
WILL THEN BUILD ACROSS THE REGION SUNDAY AND MONDAY WITH FAIR BUT
CHILLY WEATHER. LOW PRESSURE DEVELOPING ACROSS NEW ENGLAND IS LIKELY
TO BRING RAIN OR SNOW TO OUR REGION ON TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 700 AM...REGIONAL RADAR IMAGERY SHOWS A LARGE AREA OF
PRECIPITATION ACROSS MOST OF THE CWA...WITH THE ONLY DRY AREAS
NORTH OF A IAG-ART LINE. THERE WILL CONTINUE TO BE A SHARP CUT OFF
ON THE BACK OF THE SYSTEM...WITH AREAS NORTH OF NIAGARA FALLS TO
WATERTOWN LIKELY TO STAY DRY WHILE EVERYWHERE ELSE GETS A SOAKING
RAIN. IN TERMS OF MODEL GUIDANCE...THE HRRR IS IN LINE WITH MODEL
CONSENSUS AND PAINTS A PRETTY REASONABLE PICTURE OF HOW THE EVENT
IS LIKELY TO PLAY OUT. PRECIPITATION WILL TAPER OFF FROM WEST TO
EAST THIS AFTERNOON. THIS WILL BRING A DECENT AMOUNT OF RAIN TO
THE SOUTHERN TIER WITH A CONSENSUS OF HIGH-RES GUIDANCE BRINGING
HALF TO THREE-QUARTERS OF AN INCH OF RAIN. AMOUNTS WILL TAPER OFF
ABRUPTLY NORTH OF THIS...WITH BARELY MEASURABLE AMOUNTS NW OF
IAG/ART.
AS FOR PRECIPITATION TYPE...TEMPERATURES ARE ABOVE FREEZING IN MOST
AREAS WITH ONLY HIGHER TERRAIN IN LEWIS COUNTY STILL BELOW
FREEZING WHERE A WINTER WEATHER ADVISORY REMAINS IN PLACE.
ELSEWHERE...PRECIPITATION WILL FALL AS RAIN THROUGH THIS MORNING. COLDER
AIR (BOTH SURFACE AND ALOFT) WILL BUILD IN WHEN THE LOW PASSES TO
THE SOUTH AND SHIFTS WINDS TO THE NORTH THIS AFTERNOON. HOWEVER...THIS
WILL ONLY LEAVE A NARROW MARGIN FOR SNOW JUST AS PRECIPITATION IS
TAPERING OFF. LITTLE...IF ANY...ACCUMULATION IS EXPECTED BEFORE
PRECIPITATION ENDS.
THERE WILL ALSO BE AREAS OF FOG THIS MORNING...ESPECIALLY ACROSS
HIGHER TERRAIN IN THE SOUTHERN TIER.
HIGH PRESSURE WILL BUILD ACROSS THE UPPER LAKES THIS EVENING...THEN
GRADUALLY SHIFT INTO ONTARIO AND QUEBEC LATE TONIGHT. THIS WILL
BRING COOLER AND DRIER AIR INTO THE REGION TONIGHT. THE NORTHERLY
FLOW ACROSS THE LAKES MAY INITIALLY DELAY CLEARING...BUT WITH 850MB
TEMPERATURES ONLY -6C...LAKE INDUCED INSTABILITY WILL BE TOO SMALL TO
SUPPORT LAKE EFFECT PRECIPITATION AND MARGINAL TO RESULT IN LAKE
EFFECT CLOUDS. EXPECT CLOUDS TO LINGER THIS EVENING IN UPSLOPE
LOCATIONS...BUT EVENTUALLY SCATTER OUT LATE TONIGHT. EARLIER
CLEARING SHOULD ALLOW FOR LOWS 10 TO 15 EAST OF LAKE ONTARIO...WITH
UPPER TEENS TO LOWER 20S ELSEWHERE. THERE IS A SMALL CHANCE FOR
BLACK ICE IN SPOTS TONIGHT...BUT IT APPEARS WINDS LATE THIS
AFTERNOON AND EARLY EVENING SHOULD HELP DRY OUT ROADS IN MANY AREAS
BEFORE TEMPERATURES DROP BELOW FREEZING.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
FAIR WEATHER IS EXPECTED SUNDAY THROUGH MONDAY NIGHT AS AN AREA OF
HIGH PRESSURE CROSSES SOUTHERN CANADA. THIS HIGH PRESSURE...STARTING
SUNDAY MORNING TO OUR WEST WILL BRING A LIGHT AND COOL NORTHERLY
FLOW ACROSS NEW YORK STATE. THOUGH A GOOD DEAL OF SUNSHINE IS
EXPECTED...THESE COOL NORTHERLY WINDS WILL KEEP MOST AREAS IN THE
20S THROUGH THE DAY. SUNDAY NIGHT OUR WINDS WILL VEER AROUND TO
EASTERLY AND THEN SOUTHEASTERLY ON MONDAY BEHIND THE BUBBLE OF HIGH
PRESSURE. A SEASONABLY COOL SUNDAY NIGHT WILL WARM TO THE MID 30S TO
LOWER 40S ACROSS THE REGION MONDAY WITH THE VEERING WINDS. AS
SOUTHERLY FLOW ALOFT INCREASES THROUGH THE DAY MONDAY EXPECT CLOUDS
TO THICKEN THROUGH THE DAY. A TIGHTENING PRESSURE GRADIENT BETWEEN
THE COOLER HIGH PRESSURE AIRMASS TO OUR SOUTHEAST AND A WARMING
AIRMASS AHEAD OF AN AREA OF LOW PRESSURE OVER THE WESTERN GREAT
LAKES WILL BRING A GUSTY BREEZE ACROSS THE WESTERN AND CENTRAL PART
OF NEW YORK STATE. SOUTHEAST WINDS MAY REACH GUSTS 25 TO 35
MPH...AND POSSIBLY NEAR 40 MPH ALONG THE LAKE ERIE SHORELINE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AN INTERESTING WEATHER SYSTEM IS STILL ON TRACK TO EVOLVE MONDAY
NIGHT THROUGH WEDNESDAY. GLOBAL MODELS CONTINUE TO STRUGGLE WITH THE
FAIRLY COMPLEX EVOLUTION OF THIS SYSTEM. TO APPRECIATE THE
COMPLEXITY...THIS SYSTEM IS EXPECTED TO EVOLVE OUT OF A PACIFIC
SHORTWAVE CURRENTLY COMING ON SHORE IN THE PAC NORTHWEST ANOTHER
WEAK SOUTHERN STREAM SHORTWAVE NEAR SOUTHERN CALIFORNIA AND A HIGH
LATITUDE WAVE THAT IS PROGGED TO PHASE WITH BOTH SHORTWAVES OVER THE
NORTHEAST CONUS. MODEL TRENDS TODAY HAVE BEEN TOWARD CUTTING OFF AN
UPPER-LEVEL LOW OVER NEW ENGLAND RATHER THAN MAINTAINING AN OPEN
WAVE. HOWEVER...THIS IS WHERE THE SIMILARITIES IN THE MODELS END.
WHILE THE GFS HAS CAUGHT ONTO THE ECMWF TREND OF CUTTING OFF THE
LOW...IT REMAINS A FARTHER NORTH SOLUTION...WITH THE LOW CENTERED
OVER SOUTHERN CANADA JUST NORTH OF VERMONT BY WEDNESDAY MORNING. THE
FARTHER SOUTH ECMWF SOLUTION ACTUALLY CENTERS THE LOW OVER NEW
JERSEY BY WEDNESDAY MORNING. GIVEN THE CUT-OFF NATURE OF THIS
LOW...NEITHER SOLUTION CONTAINS SIGNIFICANT AMOUNTS OF COLD
AIR...BUT THE GFS REMAINS ON THE COOLER SIDE WITH 850MB TEMPS AROUND
-10 TO -12 C...COMPARED TO THE EC WHICH IS AROUND -6 TO -8 C.
SO WHAT DOES THIS ALL MEAN FOR THE FORECAST? THE OVERALL TREND HAS
BEEN TOWARD A WETTER SOLUTION FOR THE FORECAST AREA...AND THUS HAVE
INCREASED POPS TO LIKELY TUESDAY AND TUESDAY NIGHT. PRECIPITATION
WOULD LIKELY START AS EITHER RAIN OR A RAIN/SNOW MIX MONDAY
NIGHT...AND REMAINING A RAIN/SNOW MIX THROUGH THE DAY TUESDAY. THEN
WITH COOLER TEMPERATURES FILTERING INTO THE FORECAST AREA TUESDAY
INTO TUESDAY NIGHT MIXED PRECIPITATION SHOULD CHANGE OVER TO SNOW
WITH PERHAPS SOME LAKE ENHANCEMENT IF THE COLDER GFS SOLUTION
VERIFIES. BY WEDNESDAY A COOL...BRISK NORTHWEST FLOW WILL AGAIN KEEP
LIKELY SNOW SHOWERS ACROSS THE REGION...ESPECIALLY ACROSS THE
UPSLOPE HILLS OF SW NYS AND EASTERN LAKE ONTARIO REGION. WILL RAISE
POPS TO LIKELY HERE...AND SLOWLY TAPERING THEM OFF TO JUST CHANCE
POPS THURSDAY AS THE COMPLEX AREA OF LOW PRESSURE EXITS EASTWARD.
WEDNESDAY AND THURSDAY TEMPERATURES SHOULD AVERAGE JUST BELOW NORMAL
WITH THE COOL NW FLOW.
TIMING DIFFERENCES REMAIN ON HOW QUICKLY THE CUT OFF LOW WILL MOVE
EASTWARD WITH THE EC HOLDING THE LOW BACK THE LONGEST...AND THUS
DELAYING THE ONSET OF WARMER TEMPERATURES UNTIL THE START OF THE
FOLLOWING WEEK. THE GFS HOWEVER MOVES THE LOW OUT MORE QUICKLY...AND
THE AMPLIFYING PATTERN ACROSS THE CONUS WOULD RESULT IN MILD
TEMPERATURES ACROSS THE FORECAST AREA BY THE WEEKEND.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AT 12Z...LOW PRESSURE WAS TRACKING TO THE SOUTH OF THE
REGION...BRINGING WIDESPREAD RAIN TO AREAS SOUTH OF IAG/ART. CIGS
HAVE LOWERED CONSIDERABLY WITH A MIX OF MVFR AND IFR CONDITIONS IN
MOST AREAS. A SHIFT TO NORTHERLY WINDS SHOULD CAUSE CIGS TO
LOWER...WITH FAIRLY WIDESPREAD IFR CONDITIONS EXPECTED. EVEN LOWER
MOISTURE AND FOG IS EXPECTED ACROSS HIGHER TERRAIN SUCH AS
JHW. DRIER AIR WILL BUILD IN BEHIND THE LOW...FOLLOWED BY SURFACE
HIGH PRESSURE TONIGHT. IFR CIGS WILL GRADUALLY LIFT THIS
AFTERNOON...EVENTUALLY RETURNING TO VFR TONIGHT AS DRIER AIR
BUILDS IN TONIGHT.
OUTLOOK...
SUNDAY AND MONDAY...MAINLY VFR.
TUESDAY AND WEDNESDAY...MVFR WITH RAIN OR SNOW LIKELY.
&&
.MARINE...
WINDS WILL SHIFT TO THE NORTH ONCE LOW PRESSURE PASSES TO OUR SOUTH
TODAY. THIS WILL REQUIRE SMALL CRAFT ADVISORIES ON THE SOUTH SHORES
OF LAKE ONTARIO LATE TODAY THROUGH EARLY SUNDAY. HAVE ALSO ADDED
SMALL CRAFT ADVISORIES TO LAKE ERIE SOUTH OF DUNKIRK...WHERE THE 15
TO 20 KT FLOW SHOULD BE AMPLE TO BUILD WAVES TO 5 FT. HIGH PRESSURE
WILL BUILD IN ON SUNDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NYZ008.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
SUNDAY FOR LEZ040.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 10 AM
EST SUNDAY FOR LOZ043-044.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
SUNDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...THOMAS
LONG TERM...CHURCH/THOMAS
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
708 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE IF IN-SITU WEDGING BECAME ESTABLISHED. HOWEVER...BASED ON
UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID CLOUDS...WILL TREND
HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH HIGHS RANGING FROM
THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND 50 DEGREES OR SO
IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR INSOLATION WILL BE
MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN BAND...AND A TRAILING
SEPARATE AREA OF SHALLOW CONVECTIVE PRECIPITATION FORECAST TO MOVE
ACROSS THE AREA LATER THIS AFTERNOON AND EVENING.
THAT TRAILING PRECIPITATION WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A SURFACE
LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST NNE
FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND AREAS
OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE EASTWARD
THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO THIRDS OF
THE CWFA. IT WILL ALSO BECOME NOTICEABLY BLUSTERY IN STRONG CAA AS
THE LOW LEVEL RIDGING BUILDS EAST OF THE APPALACHIANS...WITH LOWS
MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 340 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT: BRIEF SHORTWAVE RIDGING WILL BUILD EAST
ACROSS OUR REGION AND CAUSE STRONG ARCTIC HIGH PRESSURE CENTERED
OVER NEW ENGLAND TO RIDGE DOWN THE EAST COAST THIS PERIOD...IN
ADVANCE OF A PAIR OF PHASED (OR NEARLY SO) SHORTWAVE TROUGHS
FORECAST TO AMPLIFY FROM THE PLAINS TO THE MS VALLEY THROUGH SUN
NIGHT. DESPITE MAINLY CLEAR SKIES...EXCEPT SOME LINGERING LOW CLOUDS
OVER EASTERN NC...A BRISK AND GUSTY NE WIND WILL RESULT IN RATHER
CHILLY CONDITIONS...WITH HIGHS MOSTLY IN THE MID-UPPER 40S (TO NEAR
50 SOUTH). THE AMPLIFICATION OF THE AFOREMENTIONED TROUGHS ALOFT
WILL CAUSE THE LOW LEVEL FLOW (925 MB) TO ASSUME AN INCREASINGLY
EASTERLY COMPONENT (TOWARD THE PRESSURE FALLS ACCOMPANYING HE
APPROACHING TROUGH)...SUCH THAT THE LOW CLOUDS OVER THE EASTERN PART
OF THE STATE WILL DEVELOP/ADVECT WSW ACROSS CENTRAL NC THROUGH MON
MORNING. LOWS RANGING FROM THE UPPER 20S IN THE WEST TO MIDDLE 30S
EAST.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 335 AM SATURDAY...
CONFIDENCE IS LOWER THAN DESIRED FOR A DAY 3 (MONDAY) FORECAST DUE
TO MODEL DIFFERENCES REGARDING THE INTERACTION OF NORTHERN AND
SOUTHERN STREAM SHORTWAVES AS THEY CROSS THE CENTRAL AND EASTERN US.
MODELS HAVE BEEN COMING INTO A LITTLE BETTER AGREEMENT...SHOWING THE
LEAD SOUTHERN STREAM SHORTWAVE MOVING FROM THE DEEP SOUTH ACROSS THE
CAROLINAS ON MONDAY...WITH A NORTHERN STREAM WAVE TO DIVE SOUTH
ACROSS THE REGION ON TUESDAY. IN RESPONSE TO THE LEAD WAVE...A
SURFACE LOW OFF THE SOUTHEAST COAST WILL RE-INTENSIFY AND LIFT NORTH
ALONG THE EAST COAST. THE NAM AND CANADIAN ARE STRONG OUTLIERS
REGARDING THE STRENGTH OF THE LOW AND ASSOCIATED PRECEDING EASTERLY
FLOW...PRODUCING HEAVIER PRECIP EARLIER ON MONDAY. THE ECMWF IS A
LITTLE MORE AMPLIFIED WITH THE LEAD WAVE...RESULTING MORE PRECIP
THAN THE GFS...BUT STILL RELATIVELY LIGHT AND NOT UNTIL MONDAY
AFTERNOON. THIS HAS SOME SIGNIFICANCE...AS A STRONG 1040+ MB
SURFACE HIGH EXTENDING INTO THE NC FROM NEW ENGLAND WILL BE
RETREATING DURING THE DAY BUT WOULD OFFER SOME PTYPE CONCERNS IN THE
NORTHWEST PIEDMONT WITH PRECIP EARLY MONDAY MORNING...AS THE NAM
DEPICTS. HOWEVER THIS IS DISCOUNTED AT THIS TIME. WILL SHOW POPS
INCREASING BY MIDDAY...SLIGHT CHANCE WEST TO CHANCE IN THE
EAST...ENDING FROM SOUTHWEST TO NORTHEAST MONDAY NIGHT AS THE
SURFACE LOW MOVES OFF TO THE NORTHEAST. THE QPF FORECAST IS FOR LESS
THAN A TENTH OF AN INCH...BUT WOULDNT BE SURPRISED TO SEE MODELS
PRODUCE MORE PRECIP IN LATER RUNS. HAVE LOWERED HIGHS A FEW DEGREES
ACROSS THE PIEDMONT BASED ON INCREASING POTENTIAL FOR
PRECIP...RANGING FROM LOWER 40S NORTHWEST TO NEAR 50 SOUTHEAST.
LOWS MONDAY NIGHT IN THE LOWER 30S NORTHEAST TO UPPER 30S SOUTHEAST.
A STRONG NORTHERN STREAM SHORTWAVE WILL DIVE ACROSS NC ON
TUESDAY....FOLLOWED BY A REINFORCING SHOT OF COLD ADVECTION TUESDAY
NIGHT. THE ECMWF SPITS OUT SOME VERY LIGHT QPF ACROSS THE NORTH
TUESDAY AFTERNOON...BUT WILL HOLD OFF ON INTRODUCING POPS AS MOISTURE
WILL BE LIMITED. HIGH PRESSURE IS THEN FORECAST TO BUILD ACROSS
THEN BUILD SLOWLY ACROSS THE SOUTHEAST BETWEEN AN UPPER LOW THAT
CLOSES OFF OVER NEW ENGLAND AND RIDGING OVER THE CENTRAL US. TEMPS
MAY SLOWLY MODERATE BUT WILL REMAIN AT OR JUST BELOW NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 700 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS WILL LIKELY SHIFT EAST OF RDU/FAY/RWI
BETWEEN 15-18Z...AS THE FLOW IN THAT LAYER VEERS FROM SOUTHERLY TO
SOUTHWESTERLY...AFTER WHICH TIME A SEVERAL HOUR PERIOD OF VFR
CONDITIONS ARE PROBABLE DURING THE MIDDAY TO EARLY AFTERNOON HOURS.
MEANWHILE...A PRE-FRONTAL BAND OF RAIN...FALLING FROM MOSTLY VFR
CEILINGS BUT PRODUCING MVFR SURFACE VISIBILITY RESTRICTIONS...WILL
MOVE EAST AND ARRIVE AT RDU AND FAY BETWEEN 14-15Z AND RWI BETWEEN
16-18Z...BASICALLY ON THE HEELS OF THE DEPARTING INITIAL BAND OF
MVFR CEILINGS. THEN YET A THIRD REGIME OF IFR-MVFR CONDITIONS AND
NUMEROUS TO WIDESPREAD SHOWERS (AND ISOLATED THUNDERSTORMS) WILL
SWEEP EAST INTO OUR AREA BETWEEN 17-19Z AT WESTERN TERMINALS TO
BETWEEN 20-23Z AT EASTERN ONES. THE PASSAGE OF A COLD FRONT AND
FOLLOWING BRISK NW BREEZE WILL HELP SCOUR AND LIFT THE CLOUD
LAYER...PARTICULARLY AT TRIAD TERMINALS THIS EVENING...THOUGH SUB-
VFR CONDITIONS AND AREAS OF LIGHT RAIN OR DRIZZLE ARE APT TO LINGER
THROUGHOUT THE NIGHT...ESPECIALLY AT RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
706 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE. BASED ON UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID
CLOUDS...WILL TREND HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH
HIGHS RANGING FROM THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND
50 DEGREES OR SO IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR
INSOLATION WILL BE MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN
BAND...AND A TRAILING SEPARATE AREA OF SHALLOW CONVECTIVE
PRECIPITATION FORECAST TO MOVE ACROSS THE AREA LATER THIS AFTERNOON.
THAT TRAILING PRECIPITATION WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF A THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A
SURFACE LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST
NNE FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND
AREAS OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE
EASTWARD THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO
THIRDS OF THE CWFA. IT WILL ALSO BECOME NOTICEABLY BLUSTERY IN STRONG
CAA AS THE LOW LEVEL RIDGING BUILDS EAST OF THE APPALACHIANS...WITH
LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 340 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT: BRIEF SHORTWAVE RIDGING WILL BUILD EAST
ACROSS OUR REGION AND CAUSE STRONG ARCTIC HIGH PRESSURE CENTERED
OVER NEW ENGLAND TO RIDGE DOWN THE EAST COAST THIS PERIOD...IN
ADVANCE OF A PAIR OF PHASED (OR NEARLY SO) SHORTWAVE TROUGHS
FORECAST TO AMPLIFY FROM THE PLAINS TO THE MS VALLEY THROUGH SUN
NIGHT. DESPITE MAINLY CLEAR SKIES...EXCEPT SOME LINGERING LOW CLOUDS
OVER EASTERN NC...A BRISK AND GUSTY NE WIND WILL RESULT IN RATHER
CHILLY CONDITIONS...WITH HIGHS MOSTLY IN THE MID-UPPER 40S (TO NEAR
50 SOUTH). THE AMPLIFICATION OF THE AFOREMENTIONED TROUGHS ALOFT
WILL CAUSE THE LOW LEVEL FLOW (925 MB) TO ASSUME AN INCREASINGLY
EASTERLY COMPONENT (TOWARD THE PRESSURE FALLS ACCOMPANYING HE
APPROACHING TROUGH)...SUCH THAT THE LOW CLOUDS OVER THE EASTERN PART
OF THE STATE WILL DEVELOP/ADVECT WSW ACROSS CENTRAL NC THROUGH MON
MORNING. LOWS RANGING FROM THE UPPER 20S IN THE WEST TO MIDDLE 30S
EAST.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 335 AM SATURDAY...
CONFIDENCE IS LOWER THAN DESIRED FOR A DAY 3 (MONDAY) FORECAST DUE
TO MODEL DIFFERENCES REGARDING THE INTERACTION OF NORTHERN AND
SOUTHERN STREAM SHORTWAVES AS THEY CROSS THE CENTRAL AND EASTERN US.
MODELS HAVE BEEN COMING INTO A LITTLE BETTER AGREEMENT...SHOWING THE
LEAD SOUTHERN STREAM SHORTWAVE MOVING FROM THE DEEP SOUTH ACROSS THE
CAROLINAS ON MONDAY...WITH A NORTHERN STREAM WAVE TO DIVE SOUTH
ACROSS THE REGION ON TUESDAY. IN RESPONSE TO THE LEAD WAVE...A
SURFACE LOW OFF THE SOUTHEAST COAST WILL RE-INTENSIFY AND LIFT NORTH
ALONG THE EAST COAST. THE NAM AND CANADIAN ARE STRONG OUTLIERS
REGARDING THE STRENGTH OF THE LOW AND ASSOCIATED PRECEDING EASTERLY
FLOW...PRODUCING HEAVIER PRECIP EARLIER ON MONDAY. THE ECMWF IS A
LITTLE MORE AMPLIFIED WITH THE LEAD WAVE...RESULTING MORE PRECIP
THAN THE GFS...BUT STILL RELATIVELY LIGHT AND NOT UNTIL MONDAY
AFTERNOON. THIS HAS SOME SIGNIFICANCE...AS A STRONG 1040+ MB
SURFACE HIGH EXTENDING INTO THE NC FROM NEW ENGLAND WILL BE
RETREATING DURING THE DAY BUT WOULD OFFER SOME PTYPE CONCERNS IN THE
NORTHWEST PIEDMONT WITH PRECIP EARLY MONDAY MORNING...AS THE NAM
DEPICTS. HOWEVER THIS IS DISCOUNTED AT THIS TIME. WILL SHOW POPS
INCREASING BY MIDDAY...SLIGHT CHANCE WEST TO CHANCE IN THE
EAST...ENDING FROM SOUTHWEST TO NORTHEAST MONDAY NIGHT AS THE
SURFACE LOW MOVES OFF TO THE NORTHEAST. THE QPF FORECAST IS FOR LESS
THAN A TENTH OF AN INCH...BUT WOULDNT BE SURPRISED TO SEE MODELS
PRODUCE MORE PRECIP IN LATER RUNS. HAVE LOWERED HIGHS A FEW DEGREES
ACROSS THE PIEDMONT BASED ON INCREASING POTENTIAL FOR
PRECIP...RANGING FROM LOWER 40S NORTHWEST TO NEAR 50 SOUTHEAST.
LOWS MONDAY NIGHT IN THE LOWER 30S NORTHEAST TO UPPER 30S SOUTHEAST.
A STRONG NORTHERN STREAM SHORTWAVE WILL DIVE ACROSS NC ON
TUESDAY....FOLLOWED BY A REINFORCING SHOT OF COLD ADVECTION TUESDAY
NIGHT. THE ECMWF SPITS OUT SOME VERY LIGHT QPF ACROSS THE NORTH
TUESDAY AFTERNOON...BUT WILL HOLD OFF ON INTRODUCING POPS AS MOISTURE
WILL BE LIMITED. HIGH PRESSURE IS THEN FORECAST TO BUILD ACROSS
THEN BUILD SLOWLY ACROSS THE SOUTHEAST BETWEEN AN UPPER LOW THAT
CLOSES OFF OVER NEW ENGLAND AND RIDGING OVER THE CENTRAL US. TEMPS
MAY SLOWLY MODERATE BUT WILL REMAIN AT OR JUST BELOW NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 700 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS WILL LIKELY SHIFT EAST OF RDU/FAY/RWI
BETWEEN 15-18Z...AS THE FLOW IN THAT LAYER VEERS FROM SOUTHERLY TO
SOUTHWESTERLY...AFTER WHICH TIME A SEVERAL HOUR PERIOD OF VFR
CONDITIONS ARE PROBABLE DURING THE MIDDAY TO EARLY AFTERNOON HOURS.
MEANWHILE...A PRE-FRONTAL BAND OF RAIN...FALLING FROM MOSTLY VFR
CEILINGS BUT PRODUCING MVFR SURFACE VISIBILITY RESTRICTIONS...WILL
MOVE EAST AND ARRIVE AT RDU AND FAY BETWEEN 14-15Z AND RWI BETWEEN
16-18Z...BASICALLY ON THE HEELS OF THE DEPARTING INITIAL BAND OF
MVFR CEILINGS. THEN YET A THIRD REGIME OF IFR-MVFR CONDITIONS AND
NUMEROUS TO WIDESPREAD SHOWERS (AND ISOLATED THUNDERSTORMS) WILL
SWEEP EAST INTO OUR AREA BETWEEN 17-19Z AT WESTERN TERMINALS TO
BETWEEN 20-23Z AT EASTERN ONES. THE PASSAGE OF A COLD FRONT AND
FOLLOWING BRISK NW BREEZE WILL HELP SCOUR AND LIFT THE CLOUD
LAYER...PARTICULARLY AT TRIAD TERMINALS THIS EVENING...THOUGH SUB-
VFR CONDITIONS AND AREAS OF LIGHT RAIN OR DRIZZLE ARE APT TO LINGER
THROUGHOUT THE NIGHT...ESPECIALLY AT RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
634 AM EST SAT DEC 6 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE CAROLINAS BRINGING SHOWERS TODAY
AND ISOLATED THUNDERSTORMS TONIGHT...BEFORE MOVING OFFSHORE INTO
VERY EARLY SUNDAY. STRONG HIGH PRESSURE WILL BUILD SOUTH SUNDAY
AND MONDAY...BRINGING GUSTY NORTH WINDS AND COLDER TEMPERATURES.
CANADIAN HIGH PRESSURE NEXT WEEK WILL MAINTAIN SEASONABLY COOL
TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 634 AM SATURDAY...OCEAN CONVECTION ON ITS WAY OUT AND NNE
OF THE AREA BUT LIGHTER RAINFALL KNOCKING ON OUR FAR INTERIOR DOOR
STEP. SMALL ADJUSTMENTS TO POPS TO MATCH RADAR FOR THE DAYBREAK
UPDATE AND EARLY MORNING HOURLY TEMPERATURE TRENDS WERE TWEAKED TO
REFLECT RECENT METARS...THE PREVIOUS DISCUSSION FOLLOWS WITH NO
MAJOR CHANGES TO THE FORECAST TO KICK-OFF SATURDAY.
SURFACE LOW PRECEDING AN UPPER TROUGH WAS APPROACHING THE CENTRAL
APPALACHIANS...HELPING TO LIFT A COASTAL TROUGH ONTO THE CAROLINA
COAST EARLY THIS MORNING. KLTX SENSING MODERATE CONVECTION
OFFSHORE OF CAPE FEAR MOVING NORTH TOWARD SURF CITY TO CARTERET
COUNTY TO CAPE LOOKOUT. ORGANIZED PRECIPITATION WAS ADVANCING INTO
THE WESTERN CAROLINAS. THE TRENDING WEATHER FEATURES OCEAN
CONVECTION MOVING N AND NE OF NE SC/SE NC THROUGH MORNING WHILE A
BROADER SHIELD OF -RA ENCROACHES FROM THE WEST.
A COLD FRONT WILL SWEEP OFF THE COAST LATE THIS EVENING. AHEAD OF
THE FRONT DESTABILIZATION MAY STRENGTHEN IN THE AFTERNOON IF CLOUD
BREAKS ALLOW SURFACE WARMING...OTHERWISE BEST MIXED LAYER CAPES
SPIKE AS DOES OMEGA AND COLUMN MOISTURE OVER THE AREA BETWEEN
00Z-04Z. LOW-LEVEL WINDS DO NOT APPEAR TO SUPPORT A SEVERE THREAT
AHEAD OF THE FRONT BUT WILL MAINTAIN ISOLATED TSTM MENTION.
MAXIMUM TEMPERATURES WILL NOT BE EASY SINCE BREAKS IN THE CLOUDS
COULD WARM LOCAL TEMPS QUICKLY IN THE GROWING WARM SECTOR. BREAKS
HOWEVER SHOULD NOT LAST LONG WITH PLENTIFUL UPSTREAM CLOUDS NOTED
CURRENTLY...UPPER 60S TO LOWER 70S MOST PLACES AND A LITTLE COOLER
BY THE SEA. COLD AIR ADVECTION ALREADY UNDERWAY PRIOR TO DAYBREAK
IN BRISK AND DEEP NORTH WIND FLOW...AND GUSTY. MINIMUMS BY FIRST
LIGHT SUNDAY IN THE 40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STRONG HIGH PRESSURE WILL BUILD DOWN
ACROSS THE CAROLINAS ON SUNDAY. A 1045 MB HIGH WILL MOVE ACROSS
CANADA FROM JUST NORTH OF THE GREAT LAKES TO THE CANADIAN
MARITIMES BY MONDAY. TIGHTENED GRADIENT FLOW WILL EXIST BETWEEN
THIS AREA OF HIGH PRESSURE AND LOW PRESSURE LINGERING OVER THE
DISTANT OFF SHORE WATERS OF THE CAROLINAS. EXPECT GUSTY NORTHERLY
WINDS WINDS THROUGH MUCH OF THE PERIOD. SHOULD SEE SOME CLEARING
OUT ON SUNDAY IN DRY NORTHERLY FLOW ESPECIALLY THROUGH INLAND
AREAS ALTHOUGH STRONG INVERSION COULD LOCK IN A DECENT LAYER OF
MOISTURE UNDERNEATH. CAA WILL BRING 850 TEMPS DOWN SEVERAL DEGREES
THROUGH SUNDAY INTO EARLY MONDAY. COASTAL AREAS MAY BE THE LAST
PLACE TO SEE SOME SUNSHINE ON SUNDAY AFTN. PCP WATER VALUES DROP
DOWN NEAR A QUARTER OF AN INCH INLAND WEST OF I95 BUT CLOSE TO THE
COAST VALUES REMAIN AROUND A HALF INCH UNTIL LATER ON SUNDAY.
OVERALL EXPECT TO SEE SOME SUNSHINE BY SUNDAY AFTERNOON WITH TEMPS
IN THE 50S.
MID TO UPPER TROUGH WILL DIG DOWN FROM THE GREAT LAKES ON MONDAY
PUSHING NEXT NORTHERN STREAM SYSTEM EAST. THIS WILL PUSH THE HIGH
PRESSURE OFF THE COAST OF THE CANADIAN MARITIMES LEAVING A WEDGE
OF HIGH PRESSURE DOWN THROUGH THE INLAND CAROLINAS. AT THE SAME
TIME LOW PRESSURE OFF SHORE WILL RETROGRADE BACK WEST TOWARD THE
CAROLINA COAST BEFORE LIFTING OFF TO THE NORTH MON NIGHT. THE LOW
LEVEL INVERSION WILL STRENGTHEN FURTHER AS WARMER AND MOISTER FLOW
DEVELOPS IN THE LOW LEVELS. EXPECT LOW CLOUDS AND CONTINUED COOL
CONDITIONS WITH GUSTY NORTHERLY WINDS AND TEMPS IN THE 50S ONCE
AGAIN. MOST PCP SHOULD REMAIN OFF THE COAST BUT MAY SEE SOME WORK
ITS WAY INLAND THROUGH THE DAY AS LOW MOVES UP ALONG THE CAROLINA
COAST TOWARD VA. BY MON NIGHT DIGGING MID TO UPPER TROUGH WILL
PUSH COLD FRONT EAST WHILE LOW PRESSURE LIFTS OFF TO THE NORTH.
THIS WILL SQUEEZE OUT ANY REMAINING WEDGE BY EARLY TUES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...DEEP MID TO UPPER TROUGH WILL PUSH
NORTHERN STREAM SYSTEM EAST AS LOW PRESSURE SYSTEM LIFTS NORTHEAST
AWAY FROM THE CAROLINAS UP ALONG THE EASTERN SEABOARD. ONCE THIS
SYSTEM SHIFTS OFF SHORE BY LATE TUES IT WILL DRY OUT THE COLUMN
IN DEEP NW FLOW. ALL THE RESIDUAL LOW LEVEL MOISTURE WILL DIMINISH
WITH DEEP DRY COLUMN IN PLACE BY WED THROUGH FRI. OVERALL EXPECT
CLEARING SKIES ON TUES WITH STRONG DRY HIGH PRESSURE BUILDING IN.
A REINFORCING SHOT OF COLD AIR WITH 850 TEMPS DROPPING DOWN BELOW
0C WILL KEEP COOL TEMPS THROUGH MID WEEK. EXPECT HIGHS IN THE 50S
MOST DAYS WITH WED BEING THE COOLEST DAY. SHOULD SEE PLENTY OF
SUNSHINE WED AND THURS.
HIGH PRESSURE WILL MOVE CLOSER OVERHEAD BY THURS INTO FRI WITH
WEAK GRADIENT MAINTAINING LIGHT WINDS ALLOWING AIR MASS TO MODIFY
AND BECOME SLIGHTLY WARMER. A SHORTWAVE IN THE MID LEVELS WILL PASS
THROUGH THURS NIGHT INTO FRI WHICH SHOULD GIVE US SOME PASSING HIGHER
CLOUDS. WILL KEEP POPS OUT OF FORECAST FOR NOW.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE ON THE BACK END OF THE FORECAST
PERIOD WITH RESPECT TO CEILINGS AND THE TIMING OF PRECIP. LOOKS LIKE
THERE COULD BE TWO BATCHES OF RAIN/SHOWERS: THE FIRST AROUND SUNRISE
WITH A COASTAL TROUGH...THEN ANOTHER ROUND IN THE LATE AFTERNOON
AHEAD OF A COLD FRONT. MODELS ARE IN REASONABLE AGREEMENT
INTRODUCING IFR STRATUS/FOG AROUND DAYBREAK IF NOT BEFORE...AND THIS
MAKES SENSE GIVEN THE WEAK WARM AIR ADVECTION. THE HRRR MODEL THINKS
THAT ILM STANDS THE BEST CHANCE FOR MORNING PRECIP...BUT THE MYRTLES
COULD ALSO GET INTO THE ACT. THINK THE MORNING PRECIP WILL GIVE WAY
TO MVFR CEILINGS AND SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT WHICH
WILL ARRIVE AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...PERIODS OF MVFR/IFR CIGS ARE LIKELY THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK. GUSTY NORTH WINDS SUN/MON BEHIND
THE COLD FRONT. BECOMING VFR DURING TUE. VFR WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 634 AM SATURDAY...WINDS AHEAD OF A COLD FRONT WILL REMAIN
RELATIVELY LIGHT TODAY...INCREASING MORE SHARPLY INTO EARLY SUNDAY
AS COLD AIR SPILLS ACROSS THE WATERS. ADVISORY SC WATERS AND GALE
WATCH NC TO BEGINS 11Z SUNDAY WITH THIS ISSUANCE. PRESENTLY NNE
WIND 10 KT AT MASONBORO BUOY AND SE 15G17KT FRYING PAN ILLUSTRATES
WELL THE COASTAL TROUGH BOUNDARY. WILL HAVE TO WATCH FOR ADVISORY
CONDITIONS EARLIER THAN PLANNED SINCE 41013 ALREADY APPROACHING 6
FT. ISOLATED TSTMS POSSIBLE TONIGHT ON THE 0-20 NM WATERS JUST
AHEAD OF THE COLD FRONT. BY DAYBREAK SUNDAY EXPECT 30 KT GUSTS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...GALE WATCH REMAINS IN EFFECT FOR THE NC
WATERS BEGINNING SUNDAY MORNING WITH A SMALL CRAFT ADVISORY OVER
SOUTH CAROLINA WATERS AS WINDS INCREASE THROUGH SUN INTO SUN NIGHT
20 TO 30 KTS WITH FREQUENT GUSTS TO 35 KTS OR GREATER AS STRONG
HIGH PRESSURE BUILDS DOWN INTO THE CAROLINAS. THIS TIGHTENED
GRADIENT FLOW WILL CONTINUE INTO MONDAY AS WEDGE STRENGTHENS DOWN
THROUGH INLAND CAROLINAS WHILE LOW PRESSURE LINGERS AND SHIFTS
CLOSER TO THE COAST BEFORE LIFTING OFF TO THE NORTH BY EARLY TUES.
THIS WILL MAINTAIN STRONG NORTHERLY WINDS AND HIGH SEAS. SEAS WILL
RAMP UP SUN MORNING ABOVE SCA THRESHOLDS AND PEAKING CLOSE TO 10
FT IN OUTER WATERS OVERNIGHT SUN INTO EARLY MON MORNING. OVERALL
SEAS WILL INCREASE UP TO 6 TO 10 FT SUN NIGHT SUBSIDING THROUGH
MON NIGHT AS WINDS BEGIN TO DIMINISH DOWN TO 10 TO 20 KTS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE WILL BUILD DOWN FROM THE
NORTHWEST THROUGH MID WEEK. THE WINDS WILL DIMINISH THROUGH TUES
INTO WED BUT DECENT COLD SURGE COULD KICK WINDS BACK UP TUES NIGHT
TO 15 TO 20 KTS AND OUTER SEAS NEAR 6 FT. OTHERWISE EXPECT WINDS
TO DROP DOWN TO 10 TO 15 KTS THROUGH THE PERIOD WITH SEAS CLOSER
TO SCA TUES BUT DROPPING DOWN THROUGH WED TO 2 TO 5 FT.
&&
.TIDES/COASTAL FLOODING...
AS OF 700 PM WEDNESDAY...THE FULL MOON IS TODAY. WE EXPECT
ELEVATED WATER LEVELS DURING THE TIME OF HIGH TIDE THROUGH THE
WEEKEND. THE MORNING HIGH TIDE WILL BE HIGHEST AND THIS IS WHEN WE
EXPECT THE TIDE TO COME UP WELL ONTO THE BEACH. STRONG NNE WINDS
SUNDAY AND SUNDAY NIGHT WILL HELP TO ENHANCE THE ASTRONOMICAL
EFFECTS. THE LOWER CAPE FEAR RIVER WILL ALSO EXPERIENCE HIGHER THAN
PREDICTED WATER LEVELS AND MAY REACH COASTAL FLOOD ADVISORY CRITERIA
DURING THE MORNING HIGH TIDE THROUGH THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM SUNDAY TO 6 AM EST MONDAY FOR
AMZ254-256.
GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR
AMZ250-252.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MJC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 950 AM CST SAT DEC 6 2014
CLOUDS CONTINUE TO SPREAD ACROSS THE CWA AS SEEN ON SATELLITE AND
WEB CAMS...SO INCREASED CLOUD COVER FOR MUCH OF THE DAY. WE COULD
START SEEING SOME BREAKS IN THE WEST LATE AS THE EDGE OF THE CLOUD
DECK APPROACHES. THERE HAS BEEN A FEW FLURRIES REPORTED NEAR THE
WESTERN CWA BORDER SO INCLUDED AN ISOLATED MENTION THROUGH THE
NEXT FEW HOURS. LOWERED HIGHS A DEGREE OR SO WITH INCREASED
CLOUDS...BUT STILL THINK WE SHOULD GET INTO THE 20S.
UPDATE ISSUED AT 655 AM CST SAT DEC 6 2014
THERE HAS BEEN PATCHY DENSE FOG DEVELOP OVER THE PAST FEW
HOURS...BUT QUICKLY DISSIPATE ONCE MID-HIGH CLOUDS COME OVERHEAD.
THE ONLY UPDATE IS FOR THE SKY GRID TO ACCOUNT FOR MID-LEVEL
CLOUDS SPREADING OVER THE REGION A BIT FASTER THAN ANTICIPATED
(FOLLOWED THE RAP 700MB RH FIELD).
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
FREEZING RAIN POTENTIAL ON SUNDAY WILL BE THE MAIN CONCERN FOR
THIS PERIOD. 00Z MODELS IN DECENT AGREEMENT...ALTHOUGH DIFFERENCES
IN THERMAL PROFILES WILL MAKE FOR A CHALLENGING FORECAST.
HIGH PRESSURE PROPAGATES ACROSS THE REGION TODAY WITH SOUTHERLY
RETURN FLOW SETTING UP THIS AFTERNOON. SATELLITE IMAGERY AND
OBSERVATIONS INDICATE PATCHY FOG DEVELOPING...AND WILL NEED TO
MONITOR (DID INCLUDE PATCHY FOG IN THE FORECAST FOR SOME
LOCATIONS). WEAK SYSTEM WILL BE PROPAGATING ACROSS SOUTHERN CANADA
TODAY...AND ALTHOUGH THE STRONGEST FORCING WILL BE NORTH OF THE
INTERNATIONAL BORDER...DO EXPECT AN AREA OF CLOUDS TO MOVE
THROUGH THE REGION. THE TEMPERATURE FORECAST IS A BIT TRICKY. MOST
AREAS SHOULD BE ABLE TO RISE INTO THE 20S THIS AFTERNOON...THEN
AFTER A BRIEF DIP IN VALUES...STRONGER WARM AIR ADVECTION
COMMENCES TONIGHT AND ANTICIPATE SLOWLY RISING VALUES.
MAJORITY OF MODEL GUIDANCE IS INDICATING A STRONGER SIGNAL FOR
FREEZING RAIN SUNDAY MORNING...ESPECIALLY THE SOUTHERN VALLEY INTO
WEST CENTRAL MINNESOTA AND PORTIONS OF NORTHWEST MINNESOTA (MAINLY
ALONG AND EAST OF A LINE FROM WAHPETON TO BAUDETTE). QPF AMOUNTS
LIKELY AROUND 0.10 INCHES. THE GENERAL IDEA IS THAT EVAPORATIVE
COOLING WILL TRANSITION A FREEZING RAIN/SLEET MIX TO SNOW...BUT
GIVEN THE SREF P-TYPE PROBABILITIES (VERY HIGH FREEZING RAIN
PROBABILITIES)...THE THOUGHT IS THAT THE OPERATIONAL MODELS MAY
BE EVAPORATIVELY COOLING TOO QUICKLY (WHICH DOES HAPPEN) AND/OR
TOO DRY ALOFT. IF CONFIDENCE INCREASES IN THE EXPECTED THERMAL
PROFILE...ALONG WITH SFC TEMPERATURES REMAINING BELOW
FREEZING...SOME SORT OF ADVISORY MAY BE NEEDED FOR THIS AREA.
OTHERWISE...AREAS TO THE WEST WILL LIKELY BE WELL INTO THE 30S ON
SUNDAY AND MOSTLY DRY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
SUNDAY NIGHT-MONDAY NIGHT...DEFORMATION ZONE SNOW SHOWERS SUNDAY
NIGHT INTO THE EARLY PORTIONS OF MONDAY AS THE SYSTEM FROM THE
SHORT TERM PERIOD MOVES AWAY FROM THE REGION. HIGH PRESSURE BUILDS
INTO THE REGION BY LATER MONDAY. ANTICIPATE A COLDER AIRMASS WITH
TEMPERATURES NEAR NORMAL (THE HIGHS ON MONDAY MAY OCCUR IN THE
MORNING).
TUESDAY-FRIDAY...EXTENDED PERIOD BEGINS UNDER NORTHWEST FLOW AND
NEAR AVERAGE TEMPERATURES FOR THE FIRST HALF OF DECEMBER.
AFTERWARDS GUIDANCE DIFFERS ON TIMING AND PLACEMENT OF SHORT WAVE
ENERGY RIDING THROUGH UPPER RIDGE DURING THE MIDDLE OF THE WEEK.
ECMWF PREFERS TO KEEP WAVE OVER SOUTHERN CANADA WHILE GFS IS
FARTHER SOUTH CLOSER TO THE NORTHERN/CENTRAL PLAINS INTERFACE. GFS
IS TYPICALLY A BIT FASTER WITH THIS FEATURE AND THE WEAK SHORT
WAVE IS NOT EXPECTED TO HAVE A GREAT IMPACT ON FORECAST. THE EARLY
PERIOD AVERAGE TEMPERATURES WILL BEGIN TO WARM FROM WEDNESDAY
THROUGH FRIDAY AS RETURN FLOW/WARM ADVECTION INCREASES WITH A
SHORT WAVE RIDGE BUILDING INTO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 655 AM CST SAT DEC 6 2014
AREA OF VFR CIGS WILL MOVE ACROSS THE REGION TODAY. LIGHT AND
VARIABLE WINDS WILL BECOME SOUTHERLY THIS AFTERNOON AND COULD BE A
BIT BREEZY THIS EVENING AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
655 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 655 AM CST SAT DEC 6 2014
THERE HAS BEEN PATCHY DENSE FOG DEVELOP OVER THE PAST FEW
HOURS...BUT QUICKLY DISSIPATE ONCE MID-HIGH CLOUDS COME OVERHEAD.
THE ONLY UPDATE IS FOR THE SKY GRID TO ACCOUNT FOR MID-LEVEL
CLOUDS SPREADING OVER THE REGION A BIT FASTER THAN ANTICIPATED
(FOLLOWED THE RAP 700MB RH FIELD).
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
FREEZING RAIN POTENTIAL ON SUNDAY WILL BE THE MAIN CONCERN FOR
THIS PERIOD. 00Z MODELS IN DECENT AGREEMENT...ALTHOUGH DIFFERENCES
IN THERMAL PROFILES WILL MAKE FOR A CHALLENGING FORECAST.
HIGH PRESSURE PROPAGATES ACROSS THE REGION TODAY WITH SOUTHERLY
RETURN FLOW SETTING UP THIS AFTERNOON. SATELLITE IMAGERY AND
OBSERVATIONS INDICATE PATCHY FOG DEVELOPING...AND WILL NEED TO
MONITOR (DID INCLUDE PATCHY FOG IN THE FORECAST FOR SOME
LOCATIONS). WEAK SYSTEM WILL BE PROPAGATING ACROSS SOUTHERN CANADA
TODAY...AND ALTHOUGH THE STRONGEST FORCING WILL BE NORTH OF THE
INTERNATIONAL BORDER...DO EXPECT AN AREA OF CLOUDS TO MOVE
THROUGH THE REGION. THE TEMPERATURE FORECAST IS A BIT TRICKY. MOST
AREAS SHOULD BE ABLE TO RISE INTO THE 20S THIS AFTERNOON...THEN
AFTER A BRIEF DIP IN VALUES...STRONGER WARM AIR ADVECTION
COMMENCES TONIGHT AND ANTICIPATE SLOWLY RISING VALUES.
MAJORITY OF MODEL GUIDANCE IS INDICATING A STRONGER SIGNAL FOR
FREEZING RAIN SUNDAY MORNING...ESPECIALLY THE SOUTHERN VALLEY INTO
WEST CENTRAL MINNESOTA AND PORTIONS OF NORTHWEST MINNESOTA (MAINLY
ALONG AND EAST OF A LINE FROM WAHPETON TO BAUDETTE). QPF AMOUNTS
LIKELY AROUND 0.10 INCHES. THE GENERAL IDEA IS THAT EVAPORATIVE
COOLING WILL TRANSITION A FREEZING RAIN/SLEET MIX TO SNOW...BUT
GIVEN THE SREF P-TYPE PROBABILITIES (VERY HIGH FREEZING RAIN
PROBABILITIES)...THE THOUGHT IS THAT THE OPERATIONAL MODELS MAY
BE EVAPORATIVELY COOLING TOO QUICKLY (WHICH DOES HAPPEN) AND/OR
TOO DRY ALOFT. IF CONFIDENCE INCREASES IN THE EXPECTED THERMAL
PROFILE...ALONG WITH SFC TEMPERATURES REMAINING BELOW
FREEZING...SOME SORT OF ADVISORY MAY BE NEEDED FOR THIS AREA.
OTHERWISE...AREAS TO THE WEST WILL LIKELY BE WELL INTO THE 30S ON
SUNDAY AND MOSTLY DRY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
SUNDAY NIGHT-MONDAY NIGHT...DEFORMATION ZONE SNOW SHOWERS SUNDAY
NIGHT INTO THE EARLY PORTIONS OF MONDAY AS THE SYSTEM FROM THE
SHORT TERM PERIOD MOVES AWAY FROM THE REGION. HIGH PRESSURE BUILDS
INTO THE REGION BY LATER MONDAY. ANTICIPATE A COLDER AIRMASS WITH
TEMPERATURES NEAR NORMAL (THE HIGHS ON MONDAY MAY OCCUR IN THE
MORNING).
TUESDAY-FRIDAY...EXTENDED PERIOD BEGINS UNDER NORTHWEST FLOW AND
NEAR AVERAGE TEMPERATURES FOR THE FIRST HALF OF DECEMBER.
AFTERWARDS GUIDANCE DIFFERS ON TIMING AND PLACEMENT OF SHORT WAVE
ENERGY RIDING THROUGH UPPER RIDGE DURING THE MIDDLE OF THE WEEK.
ECMWF PREFERS TO KEEP WAVE OVER SOUTHERN CANADA WHILE GFS IS
FARTHER SOUTH CLOSER TO THE NORTHERN/CENTRAL PLAINS INTERFACE. GFS
IS TYPICALLY A BIT FASTER WITH THIS FEATURE AND THE WEAK SHORT
WAVE IS NOT EXPECTED TO HAVE A GREAT IMPACT ON FORECAST. THE EARLY
PERIOD AVERAGE TEMPERATURES WILL BEGIN TO WARM FROM WEDNESDAY
THROUGH FRIDAY AS RETURN FLOW/WARM ADVECTION INCREASES WITH A
SHORT WAVE RIDGE BUILDING INTO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 655 AM CST SAT DEC 6 2014
AREA OF VFR CIGS WILL MOVE ACROSS THE REGION TODAY. LIGHT AND
VARIABLE WINDS WILL BECOME SOUTHERLY THIS AFTERNOON AND COULD BE A
BIT BREEZY THIS EVENING AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...TG
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1157 AM MST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1149 AM MST SAT DEC 6 2014
LOTS OF MID/HIGH CLOUDINESS SPREADING ACROSS SOUTHERN CO AHEAD OF
THE NEXT UPPER TROF MOVING INTO THE SOUTHWEST US. THIS HAS
RESULTED IN A SLOW WARM UP FOR PORTIONS OF THE LOWER ARKANSAS
RIVER VALLEY...KPUB TO KLHX...WHERE TEMPERATURES HAVE HELD IN THE
UPPER 30S. HAVE DROPPED MAX TEMPERATURE FOR TODAY A DEGREE OR TWO
FOR KPUB AND KLHX...AS WINDS SHOULD STAY LIGHT LIMITING MIXING.
ELSEWHERE...SOUTHERLY WINDS ACROSS THE SOUTHERN AND EASTERN
PORTIONS OF THE PLAINS SHOULD HELP TEMPERATURES WARM INTO THE
LOWER 50S. MEANWHILE...STARTING TO SEE THE FIRST ROUNDS OF SNOW
VIA KCPW OBSERVATION. THIS SHOULD BECOME MORE WIDESPREAD THROUGH
LATE AFTERNOON AND INTO THE EVENING AS THE UPPER TROF APPROACHES.
HAVE DELAYED THE ONSET OF SNOW FOR THE SANGRES BASED ON THE
LATEST SOLUTIONS FROM HRRR AND RAP13...OTHERWISE...POP GRIDS LOOK
ON TARGET. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM MST SAT DEC 6 2014
...SOME LIGHT SNOW FOR THE MOUNTAINS LATER TODAY...
A BROAD EXPANSE OF THICK HIGH CLOUDS IS OVERSPREADING WRN CO THIS
MORNING. THIS IS ASSOCIATE WITH A TROUGH THAT IS CROSSING THE W
COAST. THIS WEAK SYSTEM WILL MOVE STEADILY THROUGH THE DESERT SW
THIS MORNING...THEN PASS THROUGH ERN CO THIS EVE. CLOUD COVER SHOULD
STAY WITH US THROUGH THIS AFTERNOON...THEN GRADUALLY CLEAR
OVERNIGHT FROM W TO E. CLOUDS AND SLIGHT COOLING ALOFT WILL HOLD MAX
TEMPS ABOUT 10 DEGREES BELOW ADIABATIC MAXES...OR AROUND 50 DEGREES
FOR THE PLAINS...AND 40S FOR THE HIGH VALLEYS.
NOT SEEING MUCH POTENTIAL FOR SNOWFALL WITH THIS SYSTEM GIVEN THE
GENERALLY WEAK DYNAMICS AND QUICK PROGRESSION. BEST CHANCE FOR SOME
LIGHT ACCUMS WILL BE OVER THE SW MTS...WHICH COULD SEE 2-4 INCHES BY
SUN MORNING...MAYBE A BIT HIGHER IN SPOTS. ELSEWHERE ALONG THE
CONTDVD...JUST AN INCH OR TWO. ERN RANGES WILL SEE SOME SCT SNOW
SHOWERS AND POSSIBLY SOME LIGHT ACCUMS FOR THE HIGHER ELEVATIONS.
LOOKS RELATIVELY MILD TONIGHT FOR THE PLAINS WITH TEMPS IN THE
UPPER 20S TO AROUND FREEZING. ROSE
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 339 AM MST SAT DEC 6 2014
GENERALLY MILD AND DRY CONDITIONS ARE FORECAST TO PREVAIL ACROSS
THE REGION THROUGH THE EXTENDED PERIOD.
A FAST MOVING UPPER LEVEL SHORTWAVE TROUGH WILL BE MOVING EAST OF
THE AREA SUNDAY MORNING WITH HIGH PRESSURE ALOFT BUILDING ACROSS
THE REGION BY SUNDAY AFTERNOON. MODELS HANG ON TO A FEW LIGHT SNOW
SHOWERS OVER THE MOUNTAINS SUNDAY MORNING...WITH ALL SHOWER
ACTIVITY COMING TO AN END BY MID TO LATE MORNING SUNDAY. MIGRANT
HIGH PRESSURE WILL MOVE ACROSS THE REGION THROUGH TUESDAY. DRY
CONDITIONS WILL PERSIST UNDER THIS HIGH PRESSURE. TEMPERATURES
WILL REMAIN MILD ACROSS THE REGION WITH 50S FOR THE PLAINS FOR
AFTERNOON HIGHS.
A WEAK SHORTWAVE TROUGH IS FORECAST TO MOVE ACROSS THE DESERT
SOUTHWEST ON WEDNESDAY. ALL MODEL GUIDANCE HAS THIS DISTURBANCE
MOVING TOO FAR TO THE SOUTH TO BRING ANY PRECIPITATION TO THE
AREA. A WEAK COLD FRONT WILL IMPACT THE PLAINS...WITH A FEW
DEGREES OF COOLING EXPECTED WEDNESDAY AFTERNOON.
HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE AREA FOR LATE IN THE
WEEK AS A TROUGH STRENGTHENS ALONG THE WEST COAST. THE UPPER FLOW
ACROSS COLORADO WILL TRANSITION TO SOUTHWESTERLY BY THURSDAY WHICH
WILL AID IN AFTERNOON MIXING. EXPECT A NICE WARM UP THURSDAY AND
FRIDAY WITH LOWER 60S EXPECTED ACROSS THE PLAINS. THERE ARE SOME
MODEL DIFFERENCES FRIDAY INTO SATURDAY...THE GFS IS FASTER IN
BRINGING THE UPPER SYSTEM OFF THE WEST COAST AND ACROSS COLORADO.
THE GFS DEVELOPS WIDESPREAD PRECIPITATION ACROSS THE CONTINENTAL
DIVIDE BY FRIDAY NIGHT...AND SPREADING ACROSS THE AREA ON
SATURDAY. THE ECMWF IS ABOUT 24 HOURS SLOWER WITH THIS SYSTEM
KEEPING COLORADO DRY THROUGH SATURDAY. THIS SYSTEM WILL NEED TO BE
MONITORED...AS IT COULD BRING DECENT SNOWFALL TO THE CONTINENTAL
DIVIDE. MOZLEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1006 AM MST SAT DEC 6 2014
CIGS WILL LOWER THROUGH THE DAY AS A DISTURBANCE OUT WEST MOVES
ACROSS THE REGION. CIGS WILL REMAIN VFR AT KCOS AND KPUB WITH
WINDS INCREASING OUT OF THE SOUTH AT AROUND 10 KTS AT KCOS DURING
THE AFTERNOON. KPUB WILL SEE LIGHTER WINDS FROM THE EAST. SNOW
WILL REMAIN CONFINED TO THE MOUNTAIN AREAS TODAY. KALS MAY SEE A
PASSING SHOWER IN THE VICINITY OF THE TERMINAL THIS EVENING...BUT
PROBABILITY LOOKS TOO LOW AT THIS POINT TO WARRANT INCLUSION IN
THE TAF. MEANWHILE MOUNTAIN AREAS WILL SEE IFR TO LIFR
CONDITIONS...PARTICULARLY ALONG THE CONTDVD WHERE SNOW SHOWERS
WILL INCREASE THROUGH THE AFTERNOON AND CONTINUE THROUGH TONIGHT.
-KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...ROSE
LONG TERM...MOZLEY
AVIATION...KT
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
503 PM CST Sat Dec 6 2014
.SHORT TERM...(Tonight)
ISSUED AT 308 PM CST SAT DEC 6 2014
Clearing trend has finally started to make some headway southward
this afternoon, with the edge of the stratocumulus deck generally
along a Macomb to Peoria to Pontiac line at 230 pm. AWIPS timing
tool would suggest a position along I-72 in the 530-6 pm time frame,
while the HRRR is a bit slower around 8 pm. Additional erosion from
the northeast is indicated by the HRRR late evening, although at the
same time cirrus clouds will be streaming east from the Plains.
Thus, have mainly gone with a partly cloudy sky for tonight`s
forecast.
North/northeast flow to prevail into tonight, as high pressure
currently over Lake Superior settles southeast across the Great
Lakes. Temperatures expected to drop into the mid to upper 20s
overnight.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 308 PM CST SAT DEC 6 2014
High pressure will shift eastward from Illinois Sunday as a clipper
system approaches from the WNW. This system will start bringing
increasingly thick high clouds through the day Sunday, but the air
mass will generally remain quite dry in a layer from around 2000 to
12000 feet. This dry layer will take some time to saturate
overnight, which means only a slight chance for precipitation NW of
the Illinois River before midnight. These layers will saturate
through the night allowing a better chance for precipitation
reaching the surface mainly during the morning. Dry air will start
to move in aloft during the day Monday as the system shifts east of
the area, ending deep enough saturation for precipitation processes
to take place. Precipitation type looks to be largely rain for
central Illinois given a deep warm layer just off the surface. Still
some chance for light freezing rain with temperatures hovering very
near the freezing mark at the surface. Farther to the north, the
warm layer off the surface is less pronounced, which could allow for
snow or a mix of rain and snow to reach the surface..
A high pressure ridge will develop over the plains for much of the
week with NW flow and dry conditions for central IL. Temperatures
will remain below normal for much of the week as a result. Friday
and Saturday may see a substantial warmup as the plains ridge shifts
over IL. Only chance for precipitation in the extended forecast at
this time appears to be around Friday morning as a few models hint
at a weak disturbance meandering through the region at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 500 PM CST SAT DEC 6 2014
MVFR and IFR cigs slowly shifting south early this evening and at
the same time, a large area of cirrus clouds was streaking east into
our area. A band of moisture/clouds (MVFR) was also seen over northeast
Illinois coming off of Lake Michigan and was tracking southwest and
may affect BMI and CMI in the 01z to 03z time frame. Short term high
resolution models continue to push the low clouds south over the next
several hours reaching SPI and DEC by around 02z. These two sites look
to be the pivot point with respect to their eventual movement later
tonight with models suggesting more of a southwest to west track as
high pressure shifts over the central Great Lakes and our flow becomes
more northeast to east. Once we do lose the MVFR cigs, it appears we
will have to deal with the mid and high level (VFR) cigs late tonight
and into Sunday. Surface winds will be northeast to east at 5 to
10 kts tonight with winds becoming east to southeast at 10 to 15 kts
on Sunday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
405 PM CST SAT DEC 6 2014
.SHORT TERM...
257 PM CST
NORTHEAST FLOW OVER THE REGION AHEAD OF HIGH PRESSURE HAS
CONTINUED TO EASE IN DRIER AIR. MID-AFTERNOON VISIBLE SATELLITE
IMAGERY REVEALS ONLY SOME DEPARTING STRATUS ACROSS THE FAR
SOUTHERN FORECAST AREA...AND SOME REMAINING RIBBONS OF LAKE EFFECT
CLOUDS INTO FAR NORTHEAST IL AND NORTHWEST IN. WATER VAPOR IMAGERY
CONFIRMS DRIER MID-LEVEL AIR AND SUPPRESSION MOVING OVERHEAD WHICH
SHOULD MITIGATE CLOUDS THIS EVENING...OUTSIDE OF A FEW LAKE
EFFECT CLOUDS INCHING WESTWARD OVER NORTHERN IL WITHIN THE
VEERING FLOW. A LIGHT WIND COMPONENT WILL REMAIN THIS EVENING
ALTHOUGH AS THE 1039 MB HIGH PASSES ACROSS WI...THE WINDS WILL
LIKELY BECOME LIGHT AND VARIABLE ALLOWING FOR FURTHER TEMPERATURE
DROP. DEW POINTS ARE SEVERAL DEGREES ABOVE THIS AT PRESENT...BUT
NOT REALLY A PATTERN WHERE WOULD EXPECT FOG...ESPECIALLY ANYTHING
OF NOTE.
SOUTHEAST WINDS WILL SETTLE IN ON SUNDAY WITH THE DEPARTING HIGH
AND LOW PRESSURE MARCHING EASTWARD NEAR THE NORTHERN CONUS BORDER.
HIGH CLOUDS LOOK TO GRADUALLY INCREASE/THICKEN DURING THE
AFTERNOON. GIVEN HIGHS TODAY REACHED THE UPPER 30S TO LOWER 40S
WOULD ENVISION SUNDAY BEING IN THE SAME ARENA IF CLOUDS DO NOT
THICKEN EARLIER THAN FORECAST.
MTF
&&
.LONG TERM...
315 PM CST
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
OVERALL THE EXTENDED PERIOD WILL CONTINUE TO FEATURE A FAIRLY
PROGRESSIVE WEATHER PATTERN...WITH ONLY A QUICK HIT OF SOME COLDER
AIR FOR LATE TUESDAY INTO WEDNESDAY. THE MAIN FORECAST CONCERNS
DURING THE PERIOD WILL BE THE INCREASING POTENTIAL OF A QUICK HIT OF
WINTERY WEATHER LATE SUNDAY NIGHT INTO MONDAY MORNING.
WATER VAPOR IMAGERY INDICATES THE NEXT PACIFIC SYSTEM OF
INTEREST...NOW SHIFTING ONSHORE ACROSS WASHINGTON STATE. THIS
FEATURE...ALONG WITH AN ASSOCIATED AREA OF LOW PRESSURE IS EXPECTED
TO TRACK QUICKLY ALONG OR NEAR THE CANADIAN INTERNATIONAL
BORDER SUNDAY THROUGH TUESDAY. TYPICALLY THIS TYPE OF TRACK IS NOT
GOOD FOR MUCH PRECIPITATION FOR THE AREA...AND OVERALL THIS WILL BE
THE CASE. HOWEVER...IT APPEARS THAT QUICK HIT OF WINTRY PRECIPITATION
IS LIKELY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING.
A PERIOD OF INCREASING ISENTROPIC ASCENT COMBINED WITH SOME DECENT
Q-VECTOR CONVERGENCE...ASSOCIATED WITH ADDITIONAL SHORTWAVE ENERGY
DIGGING SOUTHEASTWARD TOWARDS THAT AREA LATER SUNDAY NIGHT...SHOULD
PROVIDE A SHORT PERIOD OF FORCING SUPPORTIVE OF PRECIPITATION ACROSS
NORTHERN ILLINOIS/NORTHWESTERN INDIANA. OVERALL...THIS STILL APPEARS
TO BE A SMALL EVENT FOR THE AREA. HOWEVER...IT APPEARS THAT A
STRENGTHENING BAROCLINIC ZONE ALONG AN OCCLUDED FRONTAL BOUNDARY MAY
PROVIDE A SHORT PERIOD OF ENHANCED MESOSCALE FORCING...SUPPORTIVE A
SHORT PERIOD OF HEAVIER PRECIPITATION...ESPECIALLY GIVEN THE PRESENCE
OF STEEP MID LEVEL LAPSE RATES INTO MONDAY MORNING. THUS...IT
APPEARS THAT BAND OF PRECIPITATION...POSSIBLY ONLY LASTING A COUPLE
HOURS AT ANY GIVEN LOCATION...IS LIKELY TO MOVE ACROSS THE AREA IN
TIME FOR THE MONDAY MORNING RUSH.
PRECIP TYPE STILL APPEARS TO BE TRICKY WITH THIS ACTIVITY EARLY
MONDAY. ASIDE FOR THE NAM SOLUTION...MOST MODEL DERIVED SOUNDINGS
ACROSS NORTHERN ILLINOIS INDICATE MAX LAYER TEMPERATURES OF ONLY +1
TO +1.5 DEGREES CELSIUS...WHICH WOULD SUGGEST ONLY PARTIAL MELTING OF
DENDRITES...POSSIBLY RESULTING IN SNOW AND SLEET PRECIP TYPES ACROSS
MOST OF FAR NORTHERN ILLINOIS. ALSO...GIVEN THAT THERE COULD BE SOME
ENHANCE PRECIP RATES WITH THIS ACTIVITY...AS WELL AS THE FACT THAT
EVAPORATIVE COOLING POTENTIAL SUNDAY NIGHT WILL BE HIGH...IT APPEARS
PRUDENT TO MENTION MORE OF A SNOW AND SLEET SCENARIO ACROSS FAR
NORTHERN ILLINOIS RATHER THAN FREEZING RAIN AT THIS POINT. THEREFORE...I
HAVE TRENDED THE FORECAST IN THIS DIRECTION.
ACCUMULATIONS ARE ALSO POSSIBLE WITH THIS ACTIVITY. IN FACT...SOME
AREAS COULD GET A QUICK INCH OF SNOW...IF IT FALLS PRIMARILY AS SUCH.
AT THIS TIME IT APPEARS THE BEST POTENTIAL FOR THIS APPEARS TO BE
ROUGHLY ALONG AND NORTH OF I-88 IN NORTHERN ILLINOIS. ALTHOUGH TOTAL
AMOUNTS WILL BE LIGHT...THE POSSIBILITY OF A QUICK HALF TO ONE INCH OF
SNOW RIGHT AROUND DAYBREAK MONDAY COULD CAUSE PROBLEMS FOR THE
MONDAY MORNING COMMUTE. AREAS SOUTH OF INTERSTATE 80 COULD SEE MORE
OF MIX BAG OF RAIN...FREEZING RAIN...SLEET AND SNOW GIVEN SLIGHTLY
WARMER MID LEVEL TEMPERATURES. SURFACE TEMPERATURES HERE MAY BE
HOVERING RIGHT AROUND FREEZING...SO QUESTIONS STILL RESIDE AROUND
HOW MUCH OF THIS PRECIP WILL BE FROZEN.
ONCE THIS BAND OF HEAVER PRECIP SHIFTS EAST OF THE AREA BY LATE
MORNING...IT APPEARS THAT THE MID LEVELS WILL DRY OUT
SUBSTANTIALLY...THUS ANY LINGERING PRECIP MONDAY AFTERNOON WOULD
LIKELY BE MORE DRIZZLY. THE COLDER SIDE OF THE STORM SYSTEM WILL
ARRIVE ACROSS THE REGION BY EARLY MONDAY EVENING...AS WINDS BECOME A
BIT GUSTY OUT OF THE WEST NORTHWEST. THIS SHOULD RESULT IN A COLDER
DAY ACROSS THE AREA ON TUESDAY. MOST AREAS WILL REMAIN DRY TUESDAY
AND TUESDAY NIGHT. HOWEVER...SOME LAKE EFFECT SNOW SHOWERS OR
FLURRIES ARE POSSIBLE ACROSS NORTHWESTERN INDIANA DURING THE DAY
TUESDAY. THEN AS THE LOWER LEVEL FLOW VEERS MORE NORTHERLY LATE
TUESDAY THESE LAKE EFFECT FLURRIES COULD GET INTO NORTHEASTERN
ILLINOIS TUESDAY EVENING. OVERALL...THIS DOES NOT APPEAR TO BE MUCH
OF A LAKE EFFECT EVENT AS LAKE INDUCED INVERSION HEIGHTS DO NOT
APPEAR VERY IMPRESSIVE...AND EVEN APPEAR TO REMAIN BELOW THE DENDRITIC
GROWTH ZONE.
THE WEATHER THE REST OF THE WEEK APPEARS TO BE FAIRLY QUIT...BUT ON
A WARMING TREND. MID LEVEL HEIGHT RISES ARE EXPECTED TO OVERSPREAD
MUCH OF THE CENTRAL CONUS LATER IN THE PERIOD IN RESPONSE TO THE
PERSISTENT NEGATIVE HEIGHT ANOMALIES ACROSS THE NORTHEASTERN PACIFIC
AND GULF OF ALASKA REGION SHIFTING EASTWARD TOWARDS THE WESTERN
NORTH AMERICAN COAST. THIS PARTICULARLY PATTERN STILL LOOKS TO BE
CONDUCE FOR A PERIOD OF MUCH ABOVE NORMAL TEMPERATURES NEXT FRIDAY
AND ESPECIALLY INTO SATURDAY. MODEL GUIDANCE HAS BEEN IN GOOD
AGREEMENT IN INDICATING THIS LARGER SCALE EL NINO-LIKE PATTERN
EVOLVING...AND GIVEN THAT THIS IS PATTERN KNOWN FOR PRODUCING MILD
CONDITIONS LOCALLY...CONFIDENCE IS ABOVE AVERAGE FOR THIS PERIOD TO
EXPERIENCE ABOVE AVERAGE TEMPERATURES. AT THIS TIME I HAVE REMAINED
A BIT CONSERVATIVE ON TEMPERATURES...ONLY WARMING THEM TO NEAR 50 FOR
SATURDAY. THIS COULD BE SEVERAL DEGREES TOO LOW IF THE CURRENT MODEL
FORECASTS PAN OUT. MOST GUIDANCE IS INDICATING 925 MB TEMPERATURES
ANYWHERE FROM +6 TO +10 DEGREES CELSIUS...WHICH COULD SUPPORT
TEMPERATURES INTO THE 50S BY NEXT SATURDAY UNDER A 570+ DM MID LEVEL
RIDGE.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* THIN SCT/BKN MVFR DECK 2500-2700 FT ERODING SHORTLY...WITH
MDW/GYY LIKELY TO OBSERVE A CIG THROUGH ABOUT 00Z.
* NORTH-NORTHEAST WINDS 10-15 KT GUSTING AROUND 20 KT WILL
DIMINISH QUICKLY THROUGH EARLY EVENING. WINDS BECOME SOUTHEAST
AT OR ABOVE 10 KT SUNDAY FROM MIDDAY ON.
RATZER
//DISCUSSION...UPDATED 18Z...
MVFR CLOUDS BEGINNING TO GO BROKEN OR SCATTER OUT IN PLACES THIS
AFTERNOON. EXPECT THAT CLOUDS WILL CONTINUE TO SPREAD ONSHORE FROM
THE LAKE THROUGH THE AFTERNOON AND EARLY EVENING HOURS. WITH THE
CLOUDS BREAKING UP SOME...WINDS WILL CONTINUE TO BE GUSTY OUT OF
THE NE. HIGH PRESSURE SLIDES BY TONIGHT WHICH WILL ALLOW SKIES TO
CLEAR QUITE A BIT MORE THIS EVENING AND WINDS WILL DIE DOWN AND
BECOME EASTERLY. WITH THE HIGH EAST OF THE AREA SUNDAY...EXPECT WINDS
TO SHIFT TO THE SOUTHEAST AND APPROACH OR EXCEED 10 KT SUNDAY
AFTERNOON. HIGH CLOUDS WILL BE SPREADING IN THROUGH THE DAY.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN TRENDS OF ALL ELEMENTS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
222 PM CST
TONIGHT THROUGH SUNDAY
THE STIFF NORTHERLY WINDS ACROSS THE LAKE TODAY WILL EASE THIS
EVENING AND VEER EASTWARD BY OVERNIGHT. WAVES WILL SUBSIDE BELOW 5
FT BY LATE TONIGHT. THE PROGRESSIVE PATTERN CONTINUES WITH HIGH
PRESSURE ADVANCING OVER THE LAKE QUICKLY OVERNIGHT FOLLOWED BY
INFLUENCE OF APPROACHING LOW PRESSURE ALREADY BY SUNDAY WITH WINDS
TURNING SOUTHEASTERLY.
SUNDAY NIGHT ONWARD
STRONG HIGH PRESSURE SHIFTING EASTWARD FROM QUEBEC AND WEAK LOW
PRESSURE TRACKING EAST ALONG THE CANADIAN BORDER WILL REALLY TIGHTEN
THE PRESSURE GRADIENT AND CAUSE SOUTHEAST WINDS TO TURN SOUTH AND
STRENGTHEN ON SUNDAY NIGHT INTO MONDAY MORNING. LOOKING AT GUSTS
PRIMARILY UP TO 25 TO 30 KT OVER THE OPEN WATERS...BUT COULD SEE A
FEW GALE FORCE GUSTS ON NORTH HALF. COLD FRONT TRAILING FROM THE
WEAK LOW PRESSURE WILL CROSS THE LAKE MONDAY EVENING AND
NIGHT...FOLLOWED BY ANOTHER EXPANSIVE HIGH PRESSURE. WINDS WILL TURN
WEST-NORTHWEST MONDAY NIGHT TO NORTHERLY BY TUESDAY MORNING.
CURRENTLY EXPECTING SPEEDS/GUSTS UP TO 30 KT LATE MONDAY NIGHT
THROUGH TUESDAY...BUT AGAIN CANNOT RULE OUT A PERIOD OF GALES ON THE
NORTH TUESDAY MORNING WHEN PRESSURE RISES MAXIMIZE. NORTHERLY WINDS
WILL GRADUALLY DIMINISH ON TUESDAY NIGHT INTO WEDNESDAY AS THE HIGH
TRAVERSES THE LAKE...SHIFTING TO SOUTHWEST ON THURSDAY INTO THURSDAY
NIGHT ON THE BACK SIDE OF THE HIGH.
FOR THE NEARSHORE WATERS...SMALL CRAFT ADVISORY CRITERIA IS POSSIBLE
SUNDAY NIGHT INTO MONDAY MORNING...ESPECIALLY FOR THE ILLINOIS
SHORE. SMALL CRAFT CONDITIONS ARE THEN LIKELY TUESDAY MORNING INTO
WEDNESDAY.
MTF/RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
321 PM CST Sat Dec 6 2014
.SHORT TERM...(Tonight)
ISSUED AT 308 PM CST SAT DEC 6 2014
Clearing trend has finally started to make some headway southward
this afternoon, with the edge of the stratocumulus deck generally
along a Macomb to Peoria to Pontiac line at 230 pm. AWIPS timing
tool would suggest a position along I-72 in the 530-6 pm time frame,
while the HRRR is a bit slower around 8 pm. Additional erosion from
the northeast is indicated by the HRRR late evening, although at the
same time cirrus clouds will be streaming east from the Plains.
Thus, have mainly gone with a partly cloudy sky for tonight`s
forecast.
North/northeast flow to prevail into tonight, as high pressure
currently over Lake Superior settles southeast across the Great
Lakes. Temperatures expected to drop into the mid to upper 20s
overnight.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 308 PM CST SAT DEC 6 2014
High pressure will shift eastward from Illinois Sunday as a clipper
system approaches from the WNW. This system will start bringing
increasingly thick high clouds through the day Sunday, but the air
mass will generally remain quite dry in a layer from around 2000 to
12000 feet. This dry layer will take some time to saturate
overnight, which means only a slight chance for precipitation NW of
the Illinois River before midnight. These layers will saturate
through the night allowing a better chance for precipitation
reaching the surface mainly during the morning. Dry air will start
to move in aloft during the day Monday as the system shifts east of
the area, ending deep enough saturation for precipitation processes
to take place. Precipitation type looks to be largely rain for
central Illinois given a deep warm layer just off the surface. Still
some chance for light freezing rain with temperatures hovering very
near the freezing mark at the surface. Farther to the north, the
warm layer off the surface is less pronounced, which could allow for
snow or a mix of rain and snow to reach the surface..
A high pressure ridge will develop over the plains for much of the
week with NW flow and dry conditions for central IL. Temperatures
will remain below normal for much of the week as a result. Friday
and Saturday may see a substantial warmup as the plains ridge shifts
over IL. Only chance for precipitation in the extended forecast at
this time appears to be around Friday morning as a few models hint
at a weak disturbance meandering through the region at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 321 PM CST SAT DEC 6 2014
Clearing trend has made more substantial progress than earlier
thought, reaching KPIA at 21Z. Have updated the TAFs to scatter
out the clouds before 03Z. Some increase in mid and high cloudiness
is expected from the west after 06Z. Have kept conditions VFR
overnight, but will need to watch for some potential lower
visibilities in the areas that never had a chance to really clear
out before sunset.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
316 PM CST SAT DEC 6 2014
.SHORT TERM...
257 PM CST
NORTHEAST FLOW OVER THE REGION AHEAD OF HIGH PRESSURE HAS
CONTINUED TO EASE IN DRIER AIR. MID-AFTERNOON VISIBLE SATELLITE
IMAGERY REVEALS ONLY SOME DEPARTING STRATUS ACROSS THE FAR
SOUTHERN FORECAST AREA...AND SOME REMAINING RIBBONS OF LAKE EFFECT
CLOUDS INTO FAR NORTHEAST IL AND NORTHWEST IN. WATER VAPOR IMAGERY
CONFIRMS DRIER MID-LEVEL AIR AND SUPPRESSION MOVING OVERHEAD WHICH
SHOULD MITIGATE CLOUDS THIS EVENING...OUTSIDE OF A FEW LAKE
EFFECT CLOUDS INCHING WESTWARD OVER NORTHERN IL WITHIN THE
VEERING FLOW. A LIGHT WIND COMPONENT WILL REMAIN THIS EVENING
ALTHOUGH AS THE 1039 MB HIGH PASSES ACROSS WI...THE WINDS WILL
LIKELY BECOME LIGHT AND VARIABLE ALLOWING FOR FURTHER TEMPERATURE
DROP. DEW POINTS ARE SEVERAL DEGREES ABOVE THIS AT PRESENT...BUT
NOT REALLY A PATTERN WHERE WOULD EXPECT FOG...ESPECIALLY ANYTHING
OF NOTE.
SOUTHEAST WINDS WILL SETTLE IN ON SUNDAY WITH THE DEPARTING HIGH
AND LOW PRESSURE MARCHING EASTWARD NEAR THE NORTHERN CONUS BORDER.
HIGH CLOUDS LOOK TO GRADUALLY INCREASE/THICKEN DURING THE
AFTERNOON. GIVEN HIGHS TODAY REACHED THE UPPER 30S TO LOWER 40S
WOULD ENVISION SUNDAY BEING IN THE SAME ARENA IF CLOUDS DO NOT
THICKEN EARLIER THAN FORECAST.
MTF
&&
.LONG TERM...
315 PM CST
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
OVERALL THE EXTENDED PERIOD WILL CONTINUE TO FEATURE A FAIRLY
PROGRESSIVE WEATHER PATTERN...WITH ONLY A QUICK HIT OF SOME COLDER
AIR FOR LATE TUESDAY INTO WEDNESDAY. THE MAIN FORECAST CONCERNS
DURING THE PERIOD WILL BE THE INCREASING POTENTIAL OF A QUICK HIT OF
WINTERY WEATHER LATE SUNDAY NIGHT INTO MONDAY MORNING.
WATER VAPOR IMAGERY INDICATES THE NEXT PACIFIC SYSTEM OF
INTEREST...NOW SHIFTING ONSHORE ACROSS WASHINGTON STATE. THIS
FEATURE...ALONG WITH AN ASSOCIATED AREA OF LOW PRESSURE IS EXPECTED
TO TRACK QUICKLY ALONG OR NEAR THE CANADIAN INTERNATIONAL
BORDER SUNDAY THROUGH TUESDAY. TYPICALLY THIS TYPE OF TRACK IS NOT
GOOD FOR MUCH PRECIPITATION FOR THE AREA...AND OVERALL THIS WILL BE
THE CASE. HOWEVER...IT APPEARS THAT QUICK HIT OF WINTRY PRECIPITATION
IS LIKELY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING.
A PERIOD OF INCREASING ISENTROPIC ASCENT COMBINED WITH SOME DECENT
Q-VECTOR CONVERGENCE...ASSOCIATED WITH ADDITIONAL SHORTWAVE ENERGY
DIGGING SOUTHEASTWARD TOWARDS THAT AREA LATER SUNDAY NIGHT...SHOULD
PROVIDE A SHORT PERIOD OF FORCING SUPPORTIVE OF PRECIPITATION ACROSS
NORTHERN ILLINOIS/NORTHWESTERN INDIANA. OVERALL...THIS STILL APPEARS
TO BE A SMALL EVENT FOR THE AREA. HOWEVER...IT APPEARS THAT A
STRENGTHENING BAROCLINIC ZONE ALONG AN OCCLUDED FRONTAL BOUNDARY MAY
PROVIDE A SHORT PERIOD OF ENHANCED MESOSCALE FORCING...SUPPORTIVE A
SHORT PERIOD OF HEAVIER PRECIPITATION...ESPECIALLY GIVEN THE PRESENCE
OF STEEP MID LEVEL LAPSE RATES INTO MONDAY MORNING. THUS...IT
APPEARS THAT BAND OF PRECIPITATION...POSSIBLY ONLY LASTING A COUPLE
HOURS AT ANY GIVEN LOCATION...IS LIKELY TO MOVE ACROSS THE AREA IN
TIME FOR THE MONDAY MORNING RUSH.
PRECIP TYPE STILL APPEARS TO BE TRICKY WITH THIS ACTIVITY EARLY
MONDAY. ASIDE FOR THE NAM SOLUTION...MOST MODEL DERIVED SOUNDINGS
ACROSS NORTHERN ILLINOIS INDICATE MAX LAYER TEMPERATURES OF ONLY +1
TO +1.5 DEGREES CELSIUS...WHICH WOULD SUGGEST ONLY PARTIAL MELTING OF
DENDRITES...POSSIBLY RESULTING IN SNOW AND SLEET PRECIP TYPES ACROSS
MOST OF FAR NORTHERN ILLINOIS. ALSO...GIVEN THAT THERE COULD BE SOME
ENHANCE PRECIP RATES WITH THIS ACTIVITY...AS WELL AS THE FACT THAT
EVAPORATIVE COOLING POTENTIAL SUNDAY NIGHT WILL BE HIGH...IT APPEARS
PRUDENT TO MENTION MORE OF A SNOW AND SLEET SCENARIO ACROSS FAR
NORTHERN ILLINOIS RATHER THAN FREEZING RAIN AT THIS POINT. THEREFORE...I
HAVE TRENDED THE FORECAST IN THIS DIRECTION.
ACCUMULATIONS ARE ALSO POSSIBLE WITH THIS ACTIVITY. IN FACT...SOME
AREAS COULD GET A QUICK INCH OF SNOW...IF IT FALLS PRIMARILY AS SUCH.
AT THIS TIME IT APPEARS THE BEST POTENTIAL FOR THIS APPEARS TO BE
ROUGHLY ALONG AND NORTH OF I-88 IN NORTHERN ILLINOIS. ALTHOUGH TOTAL
AMOUNTS WILL BE LIGHT...THE POSSIBILITY OF A QUICK HALF TO ONE INCH OF
SNOW RIGHT AROUND DAYBREAK MONDAY COULD CAUSE PROBLEMS FOR THE
MONDAY MORNING COMMUTE. AREAS SOUTH OF INTERSTATE 80 COULD SEE MORE
OF MIX BAG OF RAIN...FREEZING RAIN...SLEET AND SNOW GIVEN SLIGHTLY
WARMER MID LEVEL TEMPERATURES. SURFACE TEMPERATURES HERE MAY BE
HOVERING RIGHT AROUND FREEZING...SO QUESTIONS STILL RESIDE AROUND
HOW MUCH OF THIS PRECIP WILL BE FROZEN.
ONCE THIS BAND OF HEAVER PRECIP SHIFTS EAST OF THE AREA BY LATE
MORNING...IT APPEARS THAT THE MID LEVELS WILL DRY OUT
SUBSTANTIALLY...THUS ANY LINGERING PRECIP MONDAY AFTERNOON WOULD
LIKELY BE MORE DRIZZLY. THE COLDER SIDE OF THE STORM SYSTEM WILL
ARRIVE ACROSS THE REGION BY EARLY MONDAY EVENING...AS WINDS BECOME A
BIT GUSTY OUT OF THE WEST NORTHWEST. THIS SHOULD RESULT IN A COLDER
DAY ACROSS THE AREA ON TUESDAY. MOST AREAS WILL REMAIN DRY TUESDAY
AND TUESDAY NIGHT. HOWEVER...SOME LAKE EFFECT SNOW SHOWERS OR
FLURRIES ARE POSSIBLE ACROSS NORTHWESTERN INDIANA DURING THE DAY
TUESDAY. THEN AS THE LOWER LEVEL FLOW VEERS MORE NORTHERLY LATE
TUESDAY THESE LAKE EFFECT FLURRIES COULD GET INTO NORTHEASTERN
ILLINOIS TUESDAY EVENING. OVERALL...THIS DOES NOT APPEAR TO BE MUCH
OF A LAKE EFFECT EVENT AS LAKE INDUCED INVERSION HEIGHTS DO NOT
APPEAR VERY IMPRESSIVE...AND EVEN APPEAR TO REMAIN BELOW THE DENDRITIC
GROWTH ZONE.
THE WEATHER THE REST OF THE WEEK APPEARS TO BE FAIRLY QUIT...BUT ON
A WARMING TREND. MID LEVEL HEIGHT RISES ARE EXPECTED TO OVERSPREAD
MUCH OF THE CENTRAL CONUS LATER IN THE PERIOD IN RESPONSE TO THE
PERSISTENT NEGATIVE HEIGHT ANOMALIES ACROSS THE NORTHEASTERN PACIFIC
AND GULF OF ALASKA REGION SHIFTING EASTWARD TOWARDS THE WESTERN
NORTH AMERICAN COAST. THIS PARTICULARLY PATTERN STILL LOOKS TO BE
CONDUCE FOR A PERIOD OF MUCH ABOVE NORMAL TEMPERATURES NEXT FRIDAY
AND ESPECIALLY INTO SATURDAY. MODEL GUIDANCE HAS BEEN IN GOOD
AGREEMENT IN INDICATING THIS LARGER SCALE EL NINO-LIKE PATTERN
EVOLVING...AND GIVEN THAT THIS IS PATTERN KNOWN FOR PRODUCING MILD
CONDITIONS LOCALLY...CONFIDENCE IS ABOVE AVERAGE FOR THIS PERIOD TO
EXPERIENCE ABOVE AVERAGE TEMPERATURES. AT THIS TIME I HAVE REMAINED
A BIT CONSERVATIVE ON TEMPERATURES...ONLY WARMING THEM TO NEAR 50 FOR
SATURDAY. THIS COULD BE SEVERAL DEGREES TOO LOW IF THE CURRENT MODEL
FORECASTS PAN OUT. MOST GUIDANCE IS INDICATING 925 MB TEMPERATURES
ANYWHERE FROM +6 TO +10 DEGREES CELSIUS...WHICH COULD SUPPORT
TEMPERATURES INTO THE 50S BY NEXT SATURDAY UNDER A 570+ DM MID LEVEL
RIDGE.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS SCATTERING SOME TIME LATE THIS AFTERNOON.
* N-NNE WINDS 12-15 KT GUSTING TO 20-22 KT AT TIMES THROUGH THE
AFTERNOON. SE WINDS AT OR ABOVE 10 KT SUNDAY FROM MIDDAY ON.
KMD
//DISCUSSION...UPDATED 18Z...
MVFR CLOUDS BEGINNING TO GO BROKEN OR SCATTER OUT IN PLACES THIS
AFTERNOON. EXPECT THAT CLOUDS WILL CONTINUE TO SPREAD ONSHORE FROM
THE LAKE THROUGH THE AFTERNOON AND EARLY EVENING HOURS. WITH THE
CLOUDS BREAKING UP SOME...WINDS WILL CONTINUE TO BE GUSTY OUT OF
THE NE. HIGH PRESSURE SLIDES BY TONIGHT WHICH WILL ALLOW SKIES TO
CLEAR QUITE A BIT MORE THIS EVENING AND WINDS WILL DIE DOWN AND
BECOME EASTERLY. WITH THE HIGH EAST OF THE AREA SUNDAY...EXPECT WINDS
TO SHIFT TO THE SOUTHEAST AND APPROACH OR EXCEED 10 KT SUNDAY
AFTERNOON. HIGH CLOUDS WILL BE SPREADING IN THROUGH THE DAY.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* LOW CONFIDENCE IN TIMING OF SCATTERING THE MVFR CLOUD DECK LATER
TODAY.
* HIGH CONFIDENCE IN WIND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
222 PM CST
TONIGHT THROUGH SUNDAY
THE STIFF NORTHERLY WINDS ACROSS THE LAKE TODAY WILL EASE THIS
EVENING AND VEER EASTWARD BY OVERNIGHT. WAVES WILL SUBSIDE BELOW 5
FT BY LATE TONIGHT. THE PROGRESSIVE PATTERN CONTINUES WITH HIGH
PRESSURE ADVANCING OVER THE LAKE QUICKLY OVERNIGHT FOLLOWED BY
INFLUENCE OF APPROACHING LOW PRESSURE ALREADY BY SUNDAY WITH WINDS
TURNING SOUTHEASTERLY.
SUNDAY NIGHT ONWARD
STRONG HIGH PRESSURE SHIFTING EASTWARD FROM QUEBEC AND WEAK LOW
PRESSURE TRACKING EAST ALONG THE CANADIAN BORDER WILL REALLY TIGHTEN
THE PRESSURE GRADIENT AND CAUSE SOUTHEAST WINDS TO TURN SOUTH AND
STRENGTHEN ON SUNDAY NIGHT INTO MONDAY MORNING. LOOKING AT GUSTS
PRIMARILY UP TO 25 TO 30 KT OVER THE OPEN WATERS...BUT COULD SEE A
FEW GALE FORCE GUSTS ON NORTH HALF. COLD FRONT TRAILING FROM THE
WEAK LOW PRESSURE WILL CROSS THE LAKE MONDAY EVENING AND
NIGHT...FOLLOWED BY ANOTHER EXPANSIVE HIGH PRESSURE. WINDS WILL TURN
WEST-NORTHWEST MONDAY NIGHT TO NORTHERLY BY TUESDAY MORNING.
CURRENTLY EXPECTING SPEEDS/GUSTS UP TO 30 KT LATE MONDAY NIGHT
THROUGH TUESDAY...BUT AGAIN CANNOT RULE OUT A PERIOD OF GALES ON THE
NORTH TUESDAY MORNING WHEN PRESSURE RISES MAXIMIZE. NORTHERLY WINDS
WILL GRADUALLY DIMINISH ON TUESDAY NIGHT INTO WEDNESDAY AS THE HIGH
TRAVERSES THE LAKE...SHIFTING TO SOUTHWEST ON THURSDAY INTO THURSDAY
NIGHT ON THE BACK SIDE OF THE HIGH.
FOR THE NEARSHORE WATERS...SMALL CRAFT ADVISORY CRITERIA IS POSSIBLE
SUNDAY NIGHT INTO MONDAY MORNING...ESPECIALLY FOR THE ILLINOIS
SHORE. SMALL CRAFT CONDITIONS ARE THEN LIKELY TUESDAY MORNING INTO
WEDNESDAY.
MTF/RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
308 PM CST Sat Dec 6 2014
.SHORT TERM...(Tonight)
ISSUED AT 308 PM CST SAT DEC 6 2014
Clearing trend has finally started to make some headway southward
this afternoon, with the edge of the stratocumulus deck generally
along a Macomb to Peoria to Pontiac line at 230 pm. AWIPS timing
tool would suggest a position along I-72 in the 530-6 pm time frame,
while the HRRR is a bit slower around 8 pm. Additional erosion from
the northeast is indicated by the HRRR late evening, although at the
same time cirrus clouds will be streaming east from the Plains.
Thus, have mainly gone with a partly cloudy sky for tonight`s
forecast.
North/northeast flow to prevail into tonight, as high pressure
currently over Lake Superior settles southeast across the Great
Lakes. Temperatures expected to drop into the mid to upper 20s
overnight.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 308 PM CST SAT DEC 6 2014
High pressure will shift eastward from Illinois Sunday as a clipper
system approaches from the WNW. This system will start bringing
increasingly thick high clouds through the day Sunday, but the air
mass will generally remain quite dry in a layer from around 2000 to
12000 feet. This dry layer will take some time to saturate
overnight, which means only a slight chance for precipitation NW of
the Illinois River before midnight. These layers will saturate
through the night allowing a better chance for precipitation
reaching the surface mainly during the morning. Dry air will start
to move in aloft during the day Monday as the system shifts east of
the area, ending deep enough saturation for precipitation processes
to take place. Precipitation type looks to be largely rain for
central Illinois given a deep warm layer just off the surface. Still
some chance for light freezing rain with temperatures hovering very
near the freezing mark at the surface. Farther to the north, the
warm layer off the surface is less pronounced, which could allow for
snow or a mix of rain and snow to reach the surface..
A high pressure ridge will develop over the plains for much of the
week with NW flow and dry conditions for central IL. Temperatures
will remain below normal for much of the week as a result. Friday
and Saturday may see a substantial warmup as the plains ridge shifts
over IL. Only chance for precipitation in the extended forecast at
this time appears to be around Friday morning as a few models hint
at a weak disturbance meandering through the region at this time.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1133 AM CST SAT DEC 6 2014
Challenging forecast with the low cloud deck that currently covers
the TAF sites. An area of clearing is moving southwest from
northern Illinois, and is timed to reach KPIA around 2030Z.
However, guidance indicates the remainder of the TAF sites will
stay with the lower ceilings through the evening. Ceilings in
eastern Illinois and western Indiana currently around 1500 feet,
and think that there will be gradual improvement to at least that
level this afternoon. HRRR and RAP models suggest any wholesale
clearing probably would be after 06Z, as some drier air is
advected southwest from lower Michigan. Northerly winds will
gradually trend clockwise this evening as high pressure builds
into the Great Lakes, then become more east-southeast on Sunday as
the high moves away.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1238 PM CST SAT DEC 6 2014
.UPDATE...1057 AM CST
MINOR ADJUSTMENTS HAVE BEEN MADE TO CLOUD TRENDS AND TEMPERATURES
THIS AFTERNOON. BROAD WEAK COLD AIR ADVECTION CONTINUES ACROSS THE
FORECAST AREA AS LOW PRESSURE OVER THE CENTRAL APPALACHIANS PULLS
AWAY AND HIGH PRESSURE OVER NORTHERN MN BUILDS EASTWARD. SYNOPTIC
STRATUS CLOUDS CONTINUE BASICALLY SOUTH OF I-80 WHILE LAKE INDUCED
CLOUDS PERSIST ACROSS MOST OF THE CHICAGO METRO AREA. VISIBLE
SATELLITE IMAGERY IS INDICATING BREAKS ACROSS THE LAKE AS DRIER
AIR FILTERS IN AND GIVEN THE SOMEWHAT WEAK COLD ADVECTION. ACARS
DATA INDICATES THE INVERSION IS STILL STOUT BUT WEAKENING AND THE
SATURATION IS ONLY ABOUT 1000 FT THICK. WITH THE UPSTREAM SATELLITE
TRENDS AND THE SOMEWHAT SHALLOW DEPTH OF THE CLOUDS...THINK MANY
AREAS ARE GOING TO GET SOME THINNING OR SCATTERING CLOUD
COVER BY MID-AFTERNOON...WITH THE EXCEPTION BEING THE FAR
SOUTHERN FORECAST AREA. HAVE ADJUSTED TEMPERATURES AS WELL AS CAN
FOR THE FLUCTUATING CLOUD COVER...THOUGH HIGHS FALL OUT SIMILARLY
TO FORECAST.
MTF
&&
.SHORT TERM...
409 AM CST
THROUGH SATURDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT AND INTO SATURDAY MORNING...THE MAIN
FORECAST CONCERNS WILL FOCUS ON SKY COVER AND THE IMPACT ON
TEMPERATURE TRENDS. LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY
INDICATE AN EXTENSIVE STRATUS DECK ACROSS THE REGION TRAPPED BENEATH
A STRONG INVERSION BASED AT AROUND 900MB. LATEST MODEL SOUNDINGS
INDICATE THAT THE INVERSION WILL HOLD FAST THROUGH THE REMAINDER OF
THE NIGHT AND MUCH OF THE DAY SATURDAY. ALSO...AS THE CENTER OF
HIGH PRESSURE MOVES ACROSS THE UPPER GREAT LAKES AND LOW PRESSURE
CONTINUES TO MOVE THROUGH THE OHIO VALLEY...WINDS WILL REMAIN NELY
OFF OF LAKE MICHIGAN...KEEPING MUCH OF NERN IL AND NWRN IN UNDER
CLOUD COVER A BIT LONGER THAN PREVIOUSLY ANTICIPATED. AS THE CENTER
OF THE HIGH SHIFTS TO THE EAST LATE THIS AFTERNOON AND THIS
EVENING...SFC FLOW WILL VEER MORE ELY-SELY...ALLOWING THE STRATUS
DECK TO FINALLY SCATTER OUT. NWRN PORTIONS OF THE CWA...GENERALLY
WEST OF THE FOX VALLEY COULD SCATTER OUT A BIT QUICKER THAN NERN
IL/NWRN IN AND LOCATION UNDER A FETCH OFF OF LAKE MICHIGAN. THIS
MAKES THE TEMPERATURE FORECAST FOR SATURDAY A BIT TRICKY AND WILL
ULTIMATELY DEPEND ON HOW QUICKLY CLOUD COVER CAN BREAK UP.
HOWEVER...THE REGION WILL STILL BE UNDER A COLD ADVECTIVE PATTERN AS
THE CENTER OF THE HIGH BUILDS ACROSS NRN MN AND LAKE SUPERIOR
TODAY...SO THE DIURNAL TEMPERATURE TREND SHOULD BE A LITTLE SLOWER
THAN...BUT AS THE CENTER OF THE HIGH SHIFT EAST OF LAKE SUPERIOR
LATE THIS AFTERNOON...THERE IS THE POTENTIAL FOR A LITTLE WARM
ADVECTION...AND WITH CLEARING SKIES...TEMPERATURES COULD SPIKE A FEW
DEGREES LATE THIS AFTERNOON...BEFORE THE SUN ANGLE GETS TOO LOW.
FOR THE REMAINDER OF SATURDAY NIGHT...EXPECT QUIET CONDITIONS AS SFC
RIDGING EXTENDS SOUTHWEST ACROSS THE AREA AND THROUGH THE MIDDLE
MISSISSIPPI VALLEY...WITH WINDS GRADUALLY VEERING TO SELY BY SUNDAY
MORNING. WITH DECREASING CLOUD COVER...DECREASING LOW LEVEL
MOISTURE...THE LOWER LEVELS SHOULD BE ABLE TO DECOUPLE OVERNIGHT
WITH WINDS DROPPING OFF AND RADIATIVE COOLING ALLOWING FOR
TEMPERATURES TO DROP INTO THE LOWER 20S FOR MOST AREAS...WITH THE
EXCEPTION OF THE URBAN HEAT ISLAND OF THE CHICAGO METRO AREA WHICH
SHOULD REMAIN IN THE UPPER 20S TO AROUND 30F.
KREIN
&&
.LONG TERM...
409 AM CST
SUNDAY THROUGH NEXT FRIDAY...
SUNDAY IS SHAPING UP TO BE A RELATIVELY PLEASANT DAY WITH SELY WINDS
PERSISTING THROUGH THE DAY AS THE HIGH MOVES INTO SERN CANADA AND A
LOW PRESSURE SYSTEM MOVES OUT OF THE SRN CANADIAN ROCKIES AND ACROSS
THE NRN PLAINS. THE EVOLUTION OF THIS SYSTEM HAS BEEN RELATIVELY
CONSISTENT OVER RECENT MODEL RUNS...IN TRACKING ACROSS THE NORTHERN
PLAINS AND DRAGGING A WEAK COLD FRONT AS IT TRACKS EWD. WINDS AHEAD
OF THE SYSTEM WILL VEER TO MORE SOUTHERLY ALLOWING SOME WARMER AIR
TO FILTER INTO THE REGION...BRINGING HIGHS IN THE UPPER 30S ACROSS
THE AREA. THE WEATHER PICTURE BECOMES A LITTLE MORE COMPLICATED AS
THE NEXT SYSTEM APPROACHES THE REGION. SINCE HIGH PRESSURE RIDGING
IS STILL EXPECTED TO EXTEND FROM NEW ENGLAND THROUGH THE LOWER
MISSISSIPPI VALLEY...THE GULF OF MEXICO WILL BE CUT OFF FROM THE
APPROACHING SYSTEM AND THE ONLY AVAILABLE MOISTURE FOR IT TO WORK
WITH WILL BE THE MEAGER AMOUNTS IN PLACE...PWATS AROUND A QUARTER OF
AN INCH AND WHAT MOISTURE IT CAN BRING AS A PACIFIC SOURCED MID
LEVEL SHORTWAVE. THROUGH THE EVENING ON SUNDAY...SFC TEMPERATURES
ARE EXPECTED TO DROP OFF INTO THE UPPER 20S TO THE LOWER 30S. MODEL
SOUNDING FOR SUNDAY NIGHT INTO MONDAY MORNING INDICATE WARMING ABOVE
THE BOUNDARY LAYER WITH TEMPS RISING TO 1-2C ABOVE A SUB-FREEZING
SFC LAYER. THE PCPN TYPE FORECAST FOR SUNDAY NIGHT INTO MONDAY
MORNING WILL BE COMPLICATED BY THE DEPTH AND DEGREE OF THE WARM
LAYER AND HOW FAR NORTH THE WARM LAYER CAN REACH. THE LATEST
GUIDANCE SUGGESTS THAT PCPN SHOULD START OUT AS A LITTLE LIGHT SNOW
OVER THE ROCKFORD AREA EARLY SUNDAY EVENING BEFORE THE WARM
INTRUSION REACHES INTO NCNTRL IL...WITH A TRANSITION OVER TO
FREEZING RAIN AND...PERHAPS...A LITTLE SLEET MIXING IN...WHICH WOULD
BE DEPENDENT ON THE DEPTH OF THE SURFACE-BASED FREEZING LAYER. AS
THE SYSTEM SLOWLY CROSSES THE AREA...MANY LOCATIONS COULD SEE A
PERIOD OF LIGHT FREEZING RAIN LATE SUNDAY NIGHT INTO EARLY MONDAY
MORNING...BEFORE CHANGING OVER TO ALL RAIN BY MIDDAY MONDAY. WITH
AVAILABLE DEEP LAYER MOISTURE STILL LIMITED...WITH PWATS ONLY OF A
HALF INCH OR SO...PCPN AMOUNTS SHOULD BE LIGHT...BUT EVEN A LIGHT
GLAZING OF FREEZING RAIN IN TIME FOR THE MONDAY MORNING RUSH HOURS
COULD CREATE TRAVEL DIFFICULTIES. HOWEVER...HIGH PRESSURE IS
EXPECTED TO QUICKLY BUILD ACROSS THE REGION FOLLOWING THE FRONTAL
PASSAGE...AND ANY PCPN SHOULD COME TO AN END BY LATE MONDAY
AFTERNOON OVER THE WRN PORTIONS OF THE CWA AND IN THE EARLY EVENING
FOR THE FAR SOUTHEAST. TEMPERATURES SHOULD BE HIGH ENOUGH DURG THE
LATE AFTERNOON HOURS THAT THE CHANCES FOR ANY FREEZING PCPN FOR THE
EVENING RUSH HOURS ARE LOW.
AS THE NEXT AREA OF HIGH PRESSURE BUILDS ACROSS THE REGION...A SHORT
PERIOD OF COOL...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY...WITH
HIGHS IN THE LOWER TO MIDDLE 30S AND OVERNIGHT LOWS IN THE UPPER
TEENS TO LOWER 20S. THE SYSTEM PASSING THROUGH THE AREA MONDAY
NIGHT IS EXPECTED TO DEVELOP INTO A DEEP UPPER LOW OVER THE MID
ATLANTIC REGION BY WEDNESDAY AND THEN SLOWLY MOVE UP THE EAST
COAST. BY WEDNESDAY NIGHT...THE DEEP UPPER LOW WILL MOVE OVER NEW
ENGLAND AS UPPER RIDING BUILDS FROM THE SRN ROCKIES THROUGH THE
UPPER MISSISSIPPI VALLEY. A WEAK SHORTWAVE IN THE NLY FLOW ALOFT
BETWEEN THESE TO LARGE SCALE SYSTEMS COULD BRING A BIT OF LIGHT SNOW
FOR WEDNESDAY NIGHT INTO THURSDAY...BUT ANY ASSOCIATED SNOWFALL
SHOULD BE LIGHT. TOWARDS THE END OF THE WEEK..THE UPPER RIDGING IS
EXPECTED TO BUILD ACROSS THE UPPER MIDWEST...BRINGING A WARMING
TREND FOR LATE NEXT WEEK...WITH TEMPS POSSIBLY REACHING THE LOWER TO
MIDDLE 40S BY NEXT FRIDAY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS SCATTERING SOME TIME LATE THIS AFTERNOON.
* N-NNE WINDS 12-15 KT GUSTING TO 20-22 KT AT TIMES THROUGH THE
AFTERNOON. SE WINDS AT OR ABOVE 10 KT SUNDAY FROM MIDDAY ON.
KMD
//DISCUSSION...UPDATED 18Z...
MVFR CLOUDS BEGINNING TO GO BROKEN OR SCATTER OUT IN PLACES THIS
AFTERNOON. EXPECT THAT CLOUDS WILL CONTINUE TO SPREAD ONSHORE FROM
THE LAKE THROUGH THE AFTERNOON AND EARLY EVENING HOURS. WITH THE
CLOUDS BREAKING UP SOME...WINDS WILL CONTINUE TO BE GUSTY OUT OF
THE NE. HIGH PRESSURE SLIDES BY TONIGHT WHICH WILL ALLOW SKIES TO
CLEAR QUITE A BIT MORE THIS EVENING AND WINDS WILL DIE DOWN AND
BECOME EASTERLY. WITH THE HIGH EAST OF THE AREA SUNDAY...EXPECT WINDS
TO SHIFT TO THE SOUTHEAST AND APPROACH OR EXCEED 10 KT SUNDAY
AFTERNOON. HIGH CLOUDS WILL BE SPREADING IN THROUGH THE DAY.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW CONFIDENCE IN TIMING OF SCATTERING THE MVFR CLOUD DECK LATER
TODAY.
* HIGH CONFIDENCE IN WIND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
256 AM CST
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
EARLY THIS MORNING WITH STRONG HIGH PRESSURE MOVING EASTWARD ACROSS
THE EASTERN DAKOTAS. WINDS ARE STARTING TO INCREASE AS THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS TIGHTENS UP THROUGH THE MORNING.
AS A RESULT...EXPECT NORTH TO NORTHEAST WINDS TO RANGE FROM 20 TO 25
KT WITH GUSTS TO 30 KT ACROSS THE CENTRAL AND SOUTHERN PARTS OF THE
LAKE THIS MORNING/AFTERNOON WITH NORTHERN AREAS DIMINISHING THROUGH
THE AFTERNOON AS THE INFLUENCE OF THE HIGH ARRIVES. SPEEDS WILL
DIMINISH ACROSS THE LAKE THIS EVENING AND TONIGHT AS THE DIRECTION
TURNS EAST THEN SOUTHEAST AS THE HIGH SHIFTS TO THE EAST. WILL
CONTINUE WITH THE SMALL CRAFT ADVISORY INTO EARLY TONIGHT AS THE
LONG FETCH OF WIND WILL KEEP WAVES ELEVATED AFTER WINDS DIMINISH THIS
EVENING.
LOW PRESSURE WILL DEVELOP IN THE LEE OF THE NORTHERN ROCKIES SUNDAY
AND MOVE EASTWARD ALONG THE U.S./CANADIAN BORDER...CROSSING LAKE
SUPERIOR MONDAY EVENING. THE LOW WILL DRAG A COLD FRONT ACROSS THE
LAKE MONDAY EVENING. SOUTHERLY WINDS WILL INCREASE AHEAD OF THE LOW
SUNDAY AND SUNDAY NIGHT THEN SHIFT TO THE NORTHWEST BEHIND THE FRONT
MONDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD IN BEHIND THE LOW INTO
TUESDAY WITH A FAIRLY STRONG PUSH OF COLDER AIR AND A TIGHT PRESSURE
GRADIENT SUPPORTING GUSTY NORTH TO NORTHWEST WINDS. WINDS WILL
DIMINISH WEDNESDAY AS THE HIGH MOVES OVERHEAD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1133 AM CST Sat Dec 6 2014
.UPDATE...
ISSUED AT 939 AM CST SAT DEC 6 2014
Main concern for today is with cloud cover. Widespread stratus
covers the forecast area this morning, with ceilings east of I-57
managing to reach just above 1000 feet while they remain 500 feet
or less most areas west. This morning`s upper air sounding, plus
forecast soundings off the latest NAM and RAP models, show a
persistent inversion around 950 mb. There is some clearing that
has occurred over the northwest corner of Illinois, but visible
satellite loops showing only slow southern progress toward the
Quad Cities area. We`re in the time of year where low sun angle
makes it difficult to burn off the low clouds. Areas northwest of
Peoria most likely to see any sun this afternoon although there
will still be quite a few clouds around. The remainder of the CWA
should remain mainly cloudy.
Going forecast is in pretty good shape, and only required some
minor tweaks to incorporate current trends.
&&
.SHORT TERM...(Today)
ISSUED AT 323 AM CST SAT DEC 6 2014
The 08z/2am surface analysis has a 1015mb low in NC Kentucky moving
northeast along a stationary front. Rain showers on the NW flank of
the low are steadily progressing eastward out of our E-SE counties.
The back edge of precip should reach I-57 by 09z/3am and be
completely out of our IL counties by 13z/7am.
Despite dry air aloft flowing into Illinois on N-NW winds, a strong
subsidence inversion is indicated in all the short term models. That
will limit mixing of the dry air in to the low level moisture, and
work to keep clouds across our forecast area over the next 12 hours
if not well into tonight. The satellite images are showing a
clearing line progressing south toward IL across MN/WI, however,
that clearing should slow down with the intensification of the
inversion today. High temps will not climb appreciably under the
blanket of clouds, with readings topping out in the upper 30s toward
Galesburg and into the mid 40s toward Lawrenceville.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 323 AM CST SAT DEC 6 2014
High pressure continues to build into the region, although the
inversion remains and will likely see a continuation of the clouds
until the incredibly dry air aloft finally works its way down into
the higher RH in the llvls. This same dry air is also the deciding
factor in the next issue for the forecast with an approaching wave
Sun night/Monday. Prev models had more disagreement and the NAM
with a more southerly track for the wave was the outlier. With this
run, both the GFS and ECMWF starting to look a lot more like the
prev NAM. A small system developing into a larger upper trof late
in the weekend...with the look of two smaller waves bringing pops
back into the region. Although the GFS and the ECMWF are more
consistent with the prev NAM, the NAM is far more scarce with the
QPF. Keeping the forecast chances low for shower activity after
midnight Sun night/Monday... not only for lack of continuity from
run to run, but the considerable amount of dry air will take a while
to overcome. Not convinced the best lift will coincide with the
eventual saturation of the column.
Beyond Monday and its cold front, temps cool briefly, then moderate
back into the 40s for highs through the end of the week. 00z ECMWF
completely pulls back on a small disturbance Wed night/Thursday, and
should this trend continue, will likely pull the pops altogether out
of the next couple runs. For now, slight pops in the forecast to
cover a brief disturbance diving into the Great Lakes region on the
retreating edge of the larger scale 500 mb trof exiting out to the
northeast. This difference btwn the GFS and the European also
delineates the break point in the extended between any agreement in
the midst of a small pattern shift. Depth of the thickness ridge
going into day 7 and 8 will definitely result in some blend issues
going into next weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1133 AM CST SAT DEC 6 2014
Challenging forecast with the low cloud deck that currently covers
the TAF sites. An area of clearing is moving southwest from
northern Illinois, and is timed to reach KPIA around 2030Z.
However, guidance indicates the remainder of the TAF sites will
stay with the lower ceilings through the evening. Ceilings in
eastern Illinois and western Indiana currently around 1500 feet,
and think that there will be gradual improvement to at least that
level this afternoon. HRRR and RAP models suggest any wholesale
clearing probably would be after 06Z, as some drier air is
advected southwest from lower Michigan. Northerly winds will
gradually trend clockwise this evening as high pressure builds
into the Great Lakes, then become more east-southeast on Sunday as
the high moves away.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1025 AM CST SAT DEC 6 2014
.SHORT TERM...
409 AM CST
THROUGH SATURDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT AND INTO SATURDAY MORNING...THE MAIN
FORECAST CONCERNS WILL FOCUS ON SKY COVER AND THE IMPACT ON
TEMPERATURE TRENDS. LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY
INDICATE AN EXTENSIVE STRATUS DECK ACROSS THE REGION TRAPPED BENEATH
A STRONG INVERSION BASED AT AROUND 900MB. LATEST MODEL SOUNDINGS
INDICATE THAT THE INVERSION WILL HOLD FAST THROUGH THE REMAINDER OF
THE NIGHT AND MUCH OF THE DAY SATURDAY. ALSO...AS THE CENTER OF
HIGH PRESSURE MOVES ACROSS THE UPPER GREAT LAKES AND LOW PRESSURE
CONTINUES TO MOVE THROUGH THE OHIO VALLEY...WINDS WILL REMAIN NELY
OFF OF LAKE MICHIGAN...KEEPING MUCH OF NERN IL AND NWRN IN UNDER
CLOUD COVER A BIT LONGER THAN PREVIOUSLY ANTICIPATED. AS THE CENTER
OF THE HIGH SHIFTS TO THE EAST LATE THIS AFTERNOON AND THIS
EVENING...SFC FLOW WILL VEER MORE ELY-SELY...ALLOWING THE STRATUS
DECK TO FINALLY SCATTER OUT. NWRN PORTIONS OF THE CWA...GENERALLY
WEST OF THE FOX VALLEY COULD SCATTER OUT A BIT QUICKER THAN NERN
IL/NWRN IN AND LOCATION UNDER A FETCH OFF OF LAKE MICHIGAN. THIS
MAKES THE TEMPERATURE FORECAST FOR SATURDAY A BIT TRICKY AND WILL
ULTIMATELY DEPEND ON HOW QUICKLY CLOUD COVER CAN BREAK UP.
HOWEVER...THE REGION WILL STILL BE UNDER A COLD ADVECTIVE PATTERN AS
THE CENTER OF THE HIGH BUILDS ACROSS NRN MN AND LAKE SUPERIOR
TODAY...SO THE DIURNAL TEMPERATURE TREND SHOULD BE A LITTLE SLOWER
THAN...BUT AS THE CENTER OF THE HIGH SHIFT EAST OF LAKE SUPERIOR
LATE THIS AFTERNOON...THERE IS THE POTENTIAL FOR A LITTLE WARM
ADVECTION...AND WITH CLEARING SKIES...TEMPERATURES COULD SPIKE A FEW
DEGREES LATE THIS AFTERNOON...BEFORE THE SUN ANGLE GETS TOO LOW.
FOR THE REMAINDER OF SATURDAY NIGHT...EXPECT QUIET CONDITIONS AS SFC
RIDGING EXTENDS SOUTHWEST ACROSS THE AREA AND THROUGH THE MIDDLE
MISSISSIPPI VALLEY...WITH WINDS GRADUALLY VEERING TO SELY BY SUNDAY
MORNING. WITH DECREASING CLOUD COVER...DECREASING LOW LEVEL
MOISTURE...THE LOWER LEVELS SHOULD BE ABLE TO DECOUPLE OVERNIGHT
WITH WINDS DROPPING OFF AND RADIATIVE COOLING ALLOWING FOR
TEMPERATURES TO DROP INTO THE LOWER 20S FOR MOST AREAS...WITH THE
EXCEPTION OF THE URBAN HEAT ISLAND OF THE CHICAGO METRO AREA WHICH
SHOULD REMAIN IN THE UPPER 20S TO AROUND 30F.
KREIN
&&
.LONG TERM...
409 AM CST
SUNDAY THROUGH NEXT FRIDAY...
SUNDAY IS SHAPING UP TO BE A RELATIVELY PLEASANT DAY WITH SELY WINDS
PERSISTING THROUGH THE DAY AS THE HIGH MOVES INTO SERN CANADA AND A
LOW PRESSURE SYSTEM MOVES OUT OF THE SRN CANADIAN ROCKIES AND ACROSS
THE NRN PLAINS. THE EVOLUTION OF THIS SYSTEM HAS BEEN RELATIVELY
CONSISTENT OVER RECENT MODEL RUNS...IN TRACKING ACROSS THE NORTHERN
PLAINS AND DRAGGING A WEAK COLD FRONT AS IT TRACKS EWD. WINDS AHEAD
OF THE SYSTEM WILL VEER TO MORE SOUTHERLY ALLOWING SOME WARMER AIR
TO FILTER INTO THE REGION...BRINGING HIGHS IN THE UPPER 30S ACROSS
THE AREA. THE WEATHER PICTURE BECOMES A LITTLE MORE COMPLICATED AS
THE NEXT SYSTEM APPROACHES THE REGION. SINCE HIGH PRESSURE RIDGING
IS STILL EXPECTED TO EXTEND FROM NEW ENGLAND THROUGH THE LOWER
MISSISSIPPI VALLEY...THE GULF OF MEXICO WILL BE CUT OFF FROM THE
APPROACHING SYSTEM AND THE ONLY AVAILABLE MOISTURE FOR IT TO WORK
WITH WILL BE THE MEAGER AMOUNTS IN PLACE...PWATS AROUND A QUARTER OF
AN INCH AND WHAT MOISTURE IT CAN BRING AS A PACIFIC SOURCED MID
LEVEL SHORTWAVE. THROUGH THE EVENING ON SUNDAY...SFC TEMPERATURES
ARE EXPECTED TO DROP OFF INTO THE UPPER 20S TO THE LOWER 30S. MODEL
SOUNDING FOR SUNDAY NIGHT INTO MONDAY MORNING INDICATE WARMING ABOVE
THE BOUNDARY LAYER WITH TEMPS RISING TO 1-2C ABOVE A SUB-FREEZING
SFC LAYER. THE PCPN TYPE FORECAST FOR SUNDAY NIGHT INTO MONDAY
MORNING WILL BE COMPLICATED BY THE DEPTH AND DEGREE OF THE WARM
LAYER AND HOW FAR NORTH THE WARM LAYER CAN REACH. THE LATEST
GUIDANCE SUGGESTS THAT PCPN SHOULD START OUT AS A LITTLE LIGHT SNOW
OVER THE ROCKFORD AREA EARLY SUNDAY EVENING BEFORE THE WARM
INTRUSION REACHES INTO NCNTRL IL...WITH A TRANSITION OVER TO
FREEZING RAIN AND...PERHAPS...A LITTLE SLEET MIXING IN...WHICH WOULD
BE DEPENDENT ON THE DEPTH OF THE SURFACE-BASED FREEZING LAYER. AS
THE SYSTEM SLOWLY CROSSES THE AREA...MANY LOCATIONS COULD SEE A
PERIOD OF LIGHT FREEZING RAIN LATE SUNDAY NIGHT INTO EARLY MONDAY
MORNING...BEFORE CHANGING OVER TO ALL RAIN BY MIDDAY MONDAY. WITH
AVAILABLE DEEP LAYER MOISTURE STILL LIMITED...WITH PWATS ONLY OF A
HALF INCH OR SO...PCPN AMOUNTS SHOULD BE LIGHT...BUT EVEN A LIGHT
GLAZING OF FREEZING RAIN IN TIME FOR THE MONDAY MORNING RUSH HOURS
COULD CREATE TRAVEL DIFFICULTIES. HOWEVER...HIGH PRESSURE IS
EXPECTED TO QUICKLY BUILD ACROSS THE REGION FOLLOWING THE FRONTAL
PASSAGE...AND ANY PCPN SHOULD COME TO AN END BY LATE MONDAY
AFTERNOON OVER THE WRN PORTIONS OF THE CWA AND IN THE EARLY EVENING
FOR THE FAR SOUTHEAST. TEMPERATURES SHOULD BE HIGH ENOUGH DURG THE
LATE AFTERNOON HOURS THAT THE CHANCES FOR ANY FREEZING PCPN FOR THE
EVENING RUSH HOURS ARE LOW.
AS THE NEXT AREA OF HIGH PRESSURE BUILDS ACROSS THE REGION...A SHORT
PERIOD OF COOL...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY...WITH
HIGHS IN THE LOWER TO MIDDLE 30S AND OVERNIGHT LOWS IN THE UPPER
TEENS TO LOWER 20S. THE SYSTEM PASSING THROUGH THE AREA MONDAY
NIGHT IS EXPECTED TO DEVELOP INTO A DEEP UPPER LOW OVER THE MID
ATLANTIC REGION BY WEDNESDAY AND THEN SLOWLY MOVE UP THE EAST
COAST. BY WEDNESDAY NIGHT...THE DEEP UPPER LOW WILL MOVE OVER NEW
ENGLAND AS UPPER RIDING BUILDS FROM THE SRN ROCKIES THROUGH THE
UPPER MISSISSIPPI VALLEY. A WEAK SHORTWAVE IN THE NLY FLOW ALOFT
BETWEEN THESE TO LARGE SCALE SYSTEMS COULD BRING A BIT OF LIGHT SNOW
FOR WEDNESDAY NIGHT INTO THURSDAY...BUT ANY ASSOCIATED SNOWFALL
SHOULD BE LIGHT. TOWARDS THE END OF THE WEEK..THE UPPER RIDGING IS
EXPECTED TO BUILD ACROSS THE UPPER MIDWEST...BRINGING A WARMING
TREND FOR LATE NEXT WEEK...WITH TEMPS POSSIBLY REACHING THE LOWER TO
MIDDLE 40S BY NEXT FRIDAY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS AROUND 2000 FT SCATTERING SOME TIME LATE THIS AFTERNOON.
* N-NNE WINDS 12-15 KT GUSTING TO 20-22 KT AT TIMES THROUGH THE
AFTERNOON.
KMD
//DISCUSSION...UPDATED 12Z...
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
WHILE HIGH PRESSURE MOVES INTO THE UPPER MISSISSIPPI RIVER VALLEY.
STEADIER N TO NE WINDS HAVE SET UP IN THE 10-14 KT RANGE WITH
SPORADIC GUSTS ALSO APPEARING AT TIMES. GUSTS WILL LIKELY BECOME
MORE FREQUENT THIS AFTERNOON ESPECIALLY WHERE BREAKS CAN DEVELOP
IN THE CLOUD COVER. WINDS WILL GRADUALLY DIMINISH AND TURN
NORTHEAST THIS EVENING BEFORE SHIFTING SOUTHEAST TOWARD DAYBREAK
MONDAY.
CIGS WILL BE A CHALLENGE THROUGH THE MORNING. OBS SHOW BASE
HEIGHTS RANGING FROM 600-1100 FT ACROSS THE TERMINALS AND POINTS
UPSTREAM. A SLIGHT WIND COMPONENT OFF THE LAKE SEEMS TO BE KEEPING
BASES A LITTLE HIGHER WITHIN SEVERAL MILES INLAND OF THE SHORE
THANKS TO WARMER AIR OVER THE WATER. SATELLITE IMAGERY SHOWS A
WELL DEFINED BACK EDGE TO THE STRATUS ACROSS SOUTHERN WISCONSIN
WHICH IS MOVING SOUTHEAST. STRATUS IS ALSO EXTENSIVE ACROSS LAKE
MICHIGAN. THE BACK EDGE OF THIS STRATUS WILL LIKELY WORK ACROSS
MOST OF IF NOT ALL OF THE AREA THROUGH AROUND 16Z. HOWEVER...THERE
IS NOT SIGNIFICANT AMOUNTS OF DRY AIR WORKING INTO THE REGION SO
SCT-BKN STRATO CU MAY DEVELOP TOWARD MIDDAY....PROVIDED THE
CURRENT BAND DOES EXIT AND DOES NOT SLOW ITS SOUTHWARD PROGRESS.
IN OTHER WORDS THERE MAY BE A BREAK IN THE LOW CLOUDS BEFORE
DIURNAL CU DEVELOPS. ALSO...FLOW IN THE CLOUD LAYER WILL BE AIMED
FROM THE NORTHEAST RIGHT ACROSS THE LAKE SO LAKE PROCESSES MAY BE
SUFFICIENT TO KEEP STRATUS GOING AT LEAST WITHIN SEVERAL MILES OF
SHORE WELL INTO THE AFTERNOON. WILL GO AHEAD AND KEEP A LONGER
PERIOD OF STRATUS IN THE FORECAST FOR NOW WHICH COULD BE
PESSIMISTIC. OTHERWISE SKIES WILL CLEAR THIS EVENING IF THEY DO
NOT DO SO EARLIER. MORNING VSBY BETWEEN 2-5 SM WILL IMPROVE AS WE
GRADUALLY BEGIN TO WARM UP AFTER DAYBREAK.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW CONFIDENCE IN TIMING OF SCATTERING THE MVFR CLOUD DECK LATER
TODAY.
* HIGH CONFIDENCE IN WIND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
256 AM CST
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
EARLY THIS MORNING WITH STRONG HIGH PRESSURE MOVING EASTWARD ACROSS
THE EASTERN DAKOTAS. WINDS ARE STARTING TO INCREASE AS THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS TIGHTENS UP THROUGH THE MORNING.
AS A RESULT...EXPECT NORTH TO NORTHEAST WINDS TO RANGE FROM 20 TO 25
KT WITH GUSTS TO 30 KT ACROSS THE CENTRAL AND SOUTHERN PARTS OF THE
LAKE THIS MORNING/AFTERNOON WITH NORTHERN AREAS DIMINISHING THROUGH
THE AFTERNOON AS THE INFLUENCE OF THE HIGH ARRIVES. SPEEDS WILL
DIMINISH ACROSS THE LAKE THIS EVENING AND TONIGHT AS THE DIRECTION
TURNS EAST THEN SOUTHEAST AS THE HIGH SHIFTS TO THE EAST. WILL
CONTINUE WITH THE SMALL CRAFT ADVISORY INTO EARLY TONIGHT AS THE
LONG FETCH OF WIND WILL KEEP WAVES ELEVATED AFTER WINDS DIMINISH THIS
EVENING.
LOW PRESSURE WILL DEVELOP IN THE LEE OF THE NORTHERN ROCKIES SUNDAY
AND MOVE EASTWARD ALONG THE U.S./CANADIAN BORDER...CROSSING LAKE
SUPERIOR MONDAY EVENING. THE LOW WILL DRAG A COLD FRONT ACROSS THE
LAKE MONDAY EVENING. SOUTHERLY WINDS WILL INCREASE AHEAD OF THE LOW
SUNDAY AND SUNDAY NIGHT THEN SHIFT TO THE NORTHWEST BEHIND THE FRONT
MONDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD IN BEHIND THE LOW INTO
TUESDAY WITH A FAIRLY STRONG PUSH OF COLDER AIR AND A TIGHT PRESSURE
GRADIENT SUPPORTING GUSTY NORTH TO NORTHWEST WINDS. WINDS WILL
DIMINISH WEDNESDAY AS THE HIGH MOVES OVERHEAD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
940 AM CST Sat Dec 6 2014
.UPDATE...
ISSUED AT 939 AM CST SAT DEC 6 2014
Main concern for today is with cloud cover. Widespread stratus
covers the forecast area this morning, with ceilings east of I-57
managing to reach just above 1000 feet while they remain 500 feet
or less most areas west. This morning`s upper air sounding, plus
forecast soundings off the latest NAM and RAP models, show a
persistent inversion around 950 mb. There is some clearing that
has occurred over the northwest corner of Illinois, but visible
satellite loops showing only slow southern progress toward the
Quad Cities area. We`re in the time of year where low sun angle
makes it difficult to burn off the low clouds. Areas northwest of
Peoria most likely to see any sun this afternoon although there
will still be quite a few clouds around. The remainder of the CWA
should remain mainly cloudy.
Going forecast is in pretty good shape, and only required some
minor tweaks to incorporate current trends.
&&
.SHORT TERM...(Today)
ISSUED AT 323 AM CST SAT DEC 6 2014
The 08z/2am surface analysis has a 1015mb low in NC Kentucky moving
northeast along a stationary front. Rain showers on the NW flank of
the low are steadily progressing eastward out of our E-SE counties.
The back edge of precip should reach I-57 by 09z/3am and be
completely out of our IL counties by 13z/7am.
Despite dry air aloft flowing into Illinois on N-NW winds, a strong
subsidence inversion is indicated in all the short term models. That
will limit mixing of the dry air in to the low level moisture, and
work to keep clouds across our forecast area over the next 12 hours
if not well into tonight. The satellite images are showing a
clearing line progressing south toward IL across MN/WI, however,
that clearing should slow down with the intensification of the
inversion today. High temps will not climb appreciably under the
blanket of clouds, with readings topping out in the upper 30s toward
Galesburg and into the mid 40s toward Lawrenceville.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 323 AM CST SAT DEC 6 2014
High pressure continues to build into the region, although the
inversion remains and will likely see a continuation of the clouds
until the incredibly dry air aloft finally works its way down into
the higher RH in the llvls. This same dry air is also the deciding
factor in the next issue for the forecast with an approaching wave
Sun night/Monday. Prev models had more disagreement and the NAM
with a more southerly track for the wave was the outlier. With this
run, both the GFS and ECMWF starting to look a lot more like the
prev NAM. A small system developing into a larger upper trof late
in the weekend...with the look of two smaller waves bringing pops
back into the region. Although the GFS and the ECMWF are more
consistent with the prev NAM, the NAM is far more scarce with the
QPF. Keeping the forecast chances low for shower activity after
midnight Sun night/Monday... not only for lack of continuity from
run to run, but the considerable amount of dry air will take a while
to overcome. Not convinced the best lift will coincide with the
eventual saturation of the column.
Beyond Monday and its cold front, temps cool briefly, then moderate
back into the 40s for highs through the end of the week. 00z ECMWF
completely pulls back on a small disturbance Wed night/Thursday, and
should this trend continue, will likely pull the pops altogether out
of the next couple runs. For now, slight pops in the forecast to
cover a brief disturbance diving into the Great Lakes region on the
retreating edge of the larger scale 500 mb trof exiting out to the
northeast. This difference btwn the GFS and the European also
delineates the break point in the extended between any agreement in
the midst of a small pattern shift. Depth of the thickness ridge
going into day 7 and 8 will definitely result in some blend issues
going into next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 600 AM CST SAT DEC 6 2014
The cloud forecast will continue to be challenging over the next
24 hours, as a clearing line approaches central IL from the north.
However, the HRRR and NAM keep low clouds entrenched until later this
evening, while the GFS dissipates the low clouds this morning.
The HRRR does show the brief small area of break in the low clouds
that drifted across the area the last 6 hours, but it also indicates
that break will fill in and the clearing line will barely graze our NW
counties this afternoon, but not reach all the way to PIA.
The NAM/SREF/RAP forecast soundings all show a strong subsidence
inversion trapping the low level moisture across our terminal
sites today. So confidence is moderate in keeping low clouds in
place through the day. Ceiling heights will start out LIFR at
BMI/DEC and IFR at PIA/CMI/SPI. All ceilings should at least climb
to MVFR after 18z with heating of the day and lifting of the LCL.
We went with some clearing eventually developing tonight with
advancing high pressure and a deeper layer of dry air.
Winds will remain north today at 10-14kt and shift to northeast
tonight as they diminish below 10kt.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1137 AM EST SAT DEC 6 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 948 AM EST SAT DEC 6 2014
RAINFALL HAS EXITED THE FORECAST AREA FOR THE MOST PART...SO WILL
TAKE OUT POPS FOR THE REST OF THE DAY.
SHORT TERM MODELS SUGGEST LITTLE CHANCE OF ANY SIGNIFICANT CLEARING
TODAY. THICK CLOUD COVER COMBINED WITH LOW LEVEL COLD ADVECTION
SUGGESTS ONLY SUBTLE TEMPERATURE RISES FOR THE REST OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS.
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 061800Z TAFS/...
ISSUED AT 1137 AM EST SAT DEC 6 2014
A LARGE AREA OF MVFR CEILINGS 015-025 CURRENTLY ACROSS THE AREA.
SHORT TERM MODELS SUGGEST THESE CONDITIONS WILL HOLD THROUGH THE
EVENING HOURS...WITH THE POTENTIAL FOR SCATTERING OUT OF THE
CEILINGS FROM NORTH TO SOUTH TOWARDS 070600Z.
SURFACE WIND GUSTS 20-22 KTS FROM 360-020 DEGREES SHOULD CONTINUE
FOR THE AFTERNOON HOURS...DIMINISHING AROUND SUNSET.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JAS
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...JAS
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AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
1141 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1042 AM CST SAT DEC 6 2014
CURRENT SATELLITE SHOWS THE EXTENT OF THE CLOUD COVER FROM
PELLA...JUST SOUTH OF IOWA CITY TO PRINCETON. THIS CLOUD DECK HAD
SLOWED DOWN EARLIER WITH NE WINDS OFF THE LAKE. IN THE LAST COUPLE
OF HOURS THE CLEARING BEGAN TO INCREASE AND THE CLOUD DECK MOVED
SOUTH. HAD TO UPDATE THE CLOUD FORECAST TO TIME THE CURRENT DECK
BETTER. TIMING TOOL SUGGESTS SOUTHERN CWA WILL NOT CLEAR UNTIL MID
AFTERNOON. AS A RESULT TEMPS WILL BE WARMER IN THE NORTH THAN THE
SOUTH THIS AFTERNOON BY A COUPLE OF DEGREES. LOADED THE RUC HIGH
TEMPS AND THEN ADJUSTED CERTAIN SITES DOWN OR UP TO REPRESENT THE
CLOUD DECK ACROSS THE AREA. OTHERWISE...THE REST OF THE FORECAST
LOOKS GOOD.
UPDATE ISSUED AT 413 AM CST SAT DEC 6 2014
ADDED PATCHY DENSE FOG IN THE RIVER VALLEYS ACROSS THE NORTHERN
CWA. CLEARING HAS ALREADY ENTERED INTO NORTHERN IOWA AND CONTINUES
TO PUSH SOUTHWARD. FURTHER UPSTREAM...AREAS OF DENSE RADIATION FOG
HAVE DEVELOPED IN SOUTHERN MINNESOTA WITH SOME REPORTED
VISIBILITIES DOWN TO 1/4 SM. AGAIN...ANY DENSE FOG THAT DEVELOPS
OVER THE NEXT SEVERAL HOURS SHOULD BE FOCUSED IN LOW-LYING AREAS.
ALSO UPDATED SKY COVER THROUGH THE DAY WITH A FASTER NORTH TO
SOUTH BREAK UP OF THE STRATUS.
&&
.SYNOPSIS...
ISSUED AT 323 AM CST SAT DEC 6 2014
OVERVIEW...MID AND UPPER LEVEL FLOW BECOMES NORTHWESTERLY TODAY WITH
THE MIDWEST IN BETWEEN A SHORTWAVE TROUGH OVER BOTH THE EAST AND
WEST COASTS. 850 MB RIDGE AXIS WILL POSITION RIGHT ACROSS THE UPPER
MISSISSIPPI VALLEY REGION INTO SUNDAY MORNING. NO PRECIPITATION IS
FORECAST DURING THIS TIME AS THE NORTHWEST FLOW AND LARGE SCALE
SUBSIDENCE CONTINUE TO DRY OUT THE COLUMN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CST SAT DEC 6 2014
TODAY...CHALLENGE FOR TODAY WILL BE THE EXTENT AND PERSISTENCE OF
VERY LOW STRATUS CLOUDS. CURRENTLY...SFC OBSERVING STATIONS IN THE
DVN CWA ARE REPORTING CEILINGS BETWEEN 300-600 FT AGL WITH NO SIGNS
OF IMPROVEMENT SO FAR THROUGH THIS EVENING/OVERNIGHT. 11-3.9 MICRON
IR FOG PRODUCT DEPICTS THE CLEARING LINE TO NOW BE SOUTH OF KLSE
WITH A SLOW BUT STEADY SOUTHWARD PROGRESSION.
NAM/RAP FORECAST A VERY DRY COLUMN THROUGH THE DAY WITH THE
EXCEPTION OF A RESIDUAL MOIST LAYER THAT BECOMES TRAPPED AT AROUND
950-975 MB BENEATH A LARGE-SCALE SUBSIDENCE INVERSION. SOUNDINGS ARE
MORE SATURATED AT DAVENPORT AND POINTS SOUTHWARD AND LESS TO THE
N/NW. BEST CHANCES FOR CLEARING ARE N OF QUAD CITIES DURING THE
MORNING...THEN ALL BUT THE FAR SOUTHERN PORTION OF THE FORECAST AREA
DURING THE AFTN. NOT MUCH VARIATION IN SFC TEMPS TODAY WITH A SPREAD
OF ONLY MID TO UPPER 30S.
TONIGHT...LOW-LEVEL STRATUS SHOULD GET SCOURED OUT FOR MOST PLACES
BUT ANY CLEARING WILL BE BRIEF AS MID-LEVEL CLOUDS BEGIN TO STREAM
IN FROM THE SW AHEAD OF THE NEXT SHORTWAVE TROUGH SHIFTING EAST OF
THE ROCKIES. WEAK 1000-500 MB POSITIVE THICKNESS ADVECTION WILL
ENSUE AFTER 06Z/SUNDAY AS MID-LEVEL WINDS BACK FROM NW TO SW. LOWS
IN MID 20S WILL BE A FEW DEGREES ABOVE AVG.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 323 AM CST SAT DEC 6 2014
EARLY CHALLENGE IS THE SYSTEM MOVING INTO THE PACIFIC NW THAT WILL
BRING A GOOD POTENTIAL FOR LIGHT PRECIPITATION...POSSIBLY IN THE
FORM OF A WINTRY MIX...OVER THE AREA SUNDAY NIGHT INTO MONDAY
MORNING. DRY AND NEAR TO BELOW NORMAL TEMPERATURES WILL FOLLOW TUE
AND WED WITH PASSING HIGH PRESSURE. MODEL RUNS OVER THE PAST 24
HOURS HAVE TRENDED TOWARD A MORE AMPLIFIED UPPER LEVEL FLOW NEXT
WEEK RESULTING FROM A DEEPER UPPER LOW NOW DEPICTED OVER THE MID
ATLANTIC COAST AND THE NE U.S. LATE WED THROUGH FRI. THIS
SUGGESTS A LOWER CONFIDENCE LATE WEEK PERIOD WITH EVEN A POTENTIAL
FOR AT LEAST LIGHT PRECIPITATION AS THIS BLOCKING LOW MAY DELAY
THE EASTWARD PROGRESSION OF THE WESTERN U.S. UPPER RIDGE AND KEEP
A MORE ACTIVE...N-NW UPPER LEVEL FLOW IN PLACE OVERHEAD LATER INTO
THE WEEK.
SUNDAY THROUGH MONDAY...THE UPPER LEVEL SYSTEM OFF THE NW COAST IS
EXPECTED TO STRENGTHEN AND THEN PHASE WITH NORTHERN STREAM
ENERGY...DIGGING A LONGWAVE TROUGH OVER THE EASTERN U.S. TOWARD
MID WEEK. AS IT PASSES TO THE NORTH LATE SUNDAY NIGHT...IT
SENDS A ROUND OF MID LEVEL QG FORCING OVER THE FORECAST AREA ABOVE
LOW LEVEL WARM ADVECTION AND MODEST MOISTURE RETURN. TOP DOWN
APPROACH FROM FORECAST SOUNDINGS SUGGESTS A POSSIBLE RAIN/SNOW/SLEET
MIX ACROSS THE NORTHERN HALF OF THE FORECAST AREA...WITH RAIN/SNOW
CENTRAL AND MAINLY RAIN SOUTH...WHICH MAY CHANGE TO PRIMARILY RAIN
OVER ALL BUT THE FAR NORTHEAST WITH WARMING LOW LEVELS TOWARD
MORNING. CONFIDENCE REMAINS LOW IN THE MODEL DEPICTION OF
CRITICAL LOW LEVEL THERMAL PROFILES AND FURTHER ADJUSTMENTS TO
PRECIPITATION TYPES WILL LIKELY BE NEEDED. WITH THE SURFACE LOW
TRACKING WELL TO THE NORTH AND MODEST LIFT...QPF FOR THE EVENT
SHOULD BE LESS THAN A TENTH OF AN INCH WITH LITTLE IF ANY
ACCUMULATION OF SLEET OR SNOW NORTH. WITH THE SYSTEM SLOWING
SOME...HAVE EXTENDED POPS INTO MONDAY MORNING OVER THE EAST FOR
WHAT WOULD LIKELY BE RAIN OR RAIN/SNOW MIX. TEMPERATURES MAY
REACH INTO THE MID 40S IN THE SOUTH BEFORE THE COLD FRONT PUSHES
THROUGH IN THE AFTERNOON.
TUESDAY THROUGH TUE NIGHT...PASSING HIGH PRESSURE RIDGE WILL LIMIT
HIGHS TO THE 30S WITH OVERNIGHT LOWS IN THE UPPER TEENS TO LOWER
20S.
WEDNESDAY THROUGH FRIDAY...THE 00Z GFS...GEM AND ECMWF OFFER VARYING
SOLUTIONS WITH THE TIMING AND TRACK OF THE NEXT SHORTWAVE IN THE NW
FLOW AROUND MID WEEK...AND HOW FAST THE LARGE UPPER LOW EXITS THE
NORTHEAST. THE GFS AND GEM ARE IN ONE CAMP WITH LIGHT PRECIPITATION
DEVELOPING WITH THE NEXT SHORTWAVE IN THE NW FLOW AND ALONG A WARM
FRONT WED INTO WED NIGHT OVER ESPECIALLY THE SOUTH...THEN OVER THE
ENTIRE AREA WED NIGHT...WHEREAS THE ECMWF IS DRY WITH A SURFACE
RIDGE IN PLACE. RESULTING MODEL CONSENSUS BLENDS OF QPF AND POP FIELDS
SUGGESTED SEVERAL PERIODS OF LIGHT PRECIPITATION FROM WED THROUGH
FRI. WITH LOW CONFIDENCE IN THESE PERIODS DUE TO THE POOR
CONSISTENCY AND LACK OF AGREEMENT...HAVE KEPT ONLY SLIGHT CHANCES
FOR WHAT WOULD LIKELY BE LIGHT RAIN CONFINED TO ONLY WED NIGHT.
TEMPERATURES SHOULD STILL MODERATE WITH HIGHS BACK INTO THE 40S
THU AND FRI OVER ESPECIALLY THE SOUTH...BUT THE WELL ADVERTISED
TRANSITION TO MUCH ABOVE NORMAL TEMPERATURES MAY BE DELAYED TO
NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1132 AM CST SAT DEC 6 2014
MAIN CONCERN FOR AVIATION IN THE SHORT TERM ARE THE IFR CLOUD DECK
MOVING OUT OF THE AREA. THE ONLY TAF SITE AFFECTED BY THIS IS BRL
AND SHOULD SEE THE DECK OUT BY 2100Z AT THE LATEST. ONCE THE DECK
MOVES OUT VFR CONDITIONS WILL PERSIST DURING THE PERIOD. THE NAM
APPEARS TO HAVE PROBLEMS WITH BOUNDARY LAYER MOISTURE AGAIN AND
SUGGESTS THAT LOW CLOUDS WILL AFFECT THE TAF SITES TONIGHT. THAT
DOES NOT LOOK LIKELY AT ALL...SO DID NOT USE THE NAM DUE TO MODEL
ISSUES.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...SHEETS
AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
1048 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1042 AM CST SAT DEC 6 2014
CURRENT SATELLITE SHOWS THE EXTENT OF THE CLOUD COVER FROM
PELLA...JUST SOUTH OF IOWA CITY TO PRINCETON. THIS CLOUD DECK HAD
SLOWED DOWN EARLIER WITH NE WINDS OFF THE LAKE. IN THE LAST COUPLE
OF HOURS THE CLEARING BEGAN TO INCREASE AND THE CLOUD DECK MOVED
SOUTH. HAD TO UPDATE THE CLOUD FORECAST TO TIME THE CURRENT DECK
BETTER. TIMING TOOL SUGGESTS SOUTHERN CWA WILL NOT CLEAR UNTIL MID
AFTERNOON. AS A RESULT TEMPS WILL BE WARMER IN THE NORTH THAN THE
SOUTH THIS AFTERNOON BY A COUPLE OF DEGREES. LOADED THE RUC HIGH
TEMPS AND THEN ADJUSTED CERTAIN SITES DOWN OR UP TO REPRESENT THE
CLOUD DECK ACROSS THE AREA. OTHERWISE...THE REST OF THE FORECAST
LOOKS GOOD.
UPDATE ISSUED AT 413 AM CST SAT DEC 6 2014
ADDED PATCHY DENSE FOG IN THE RIVER VALLEYS ACROSS THE NORTHERN
CWA. CLEARING HAS ALREADY ENTERED INTO NORTHERN IOWA AND CONTINUES
TO PUSH SOUTHWARD. FURTHER UPSTREAM...AREAS OF DENSE RADIATION FOG
HAVE DEVELOPED IN SOUTHERN MINNESOTA WITH SOME REPORTED
VISIBILITIES DOWN TO 1/4 SM. AGAIN...ANY DENSE FOG THAT DEVELOPS
OVER THE NEXT SEVERAL HOURS SHOULD BE FOCUSED IN LOW-LYING AREAS.
ALSO UPDATED SKY COVER THROUGH THE DAY WITH A FASTER NORTH TO
SOUTH BREAK UP OF THE STRATUS.
&&
.SYNOPSIS...
ISSUED AT 323 AM CST SAT DEC 6 2014
OVERVIEW...MID AND UPPER LEVEL FLOW BECOMES NORTHWESTERLY TODAY WITH
THE MIDWEST IN BETWEEN A SHORTWAVE TROUGH OVER BOTH THE EAST AND
WEST COASTS. 850 MB RIDGE AXIS WILL POSITION RIGHT ACROSS THE UPPER
MISSISSIPPI VALLEY REGION INTO SUNDAY MORNING. NO PRECIPITATION IS
FORECAST DURING THIS TIME AS THE NORTHWEST FLOW AND LARGE SCALE
SUBSIDENCE CONTINUE TO DRY OUT THE COLUMN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CST SAT DEC 6 2014
TODAY...CHALLENGE FOR TODAY WILL BE THE EXTENT AND PERSISTENCE OF
VERY LOW STRATUS CLOUDS. CURRENTLY...SFC OBSERVING STATIONS IN THE
DVN CWA ARE REPORTING CEILINGS BETWEEN 300-600 FT AGL WITH NO SIGNS
OF IMPROVEMENT SO FAR THROUGH THIS EVENING/OVERNIGHT. 11-3.9 MICRON
IR FOG PRODUCT DEPICTS THE CLEARING LINE TO NOW BE SOUTH OF KLSE
WITH A SLOW BUT STEADY SOUTHWARD PROGRESSION.
NAM/RAP FORECAST A VERY DRY COLUMN THROUGH THE DAY WITH THE
EXCEPTION OF A RESIDUAL MOIST LAYER THAT BECOMES TRAPPED AT AROUND
950-975 MB BENEATH A LARGE-SCALE SUBSIDENCE INVERSION. SOUNDINGS ARE
MORE SATURATED AT DAVENPORT AND POINTS SOUTHWARD AND LESS TO THE
N/NW. BEST CHANCES FOR CLEARING ARE N OF QUAD CITIES DURING THE
MORNING...THEN ALL BUT THE FAR SOUTHERN PORTION OF THE FORECAST AREA
DURING THE AFTN. NOT MUCH VARIATION IN SFC TEMPS TODAY WITH A SPREAD
OF ONLY MID TO UPPER 30S.
TONIGHT...LOW-LEVEL STRATUS SHOULD GET SCOURED OUT FOR MOST PLACES
BUT ANY CLEARING WILL BE BRIEF AS MID-LEVEL CLOUDS BEGIN TO STREAM
IN FROM THE SW AHEAD OF THE NEXT SHORTWAVE TROUGH SHIFTING EAST OF
THE ROCKIES. WEAK 1000-500 MB POSITIVE THICKNESS ADVECTION WILL
ENSUE AFTER 06Z/SUNDAY AS MID-LEVEL WINDS BACK FROM NW TO SW. LOWS
IN MID 20S WILL BE A FEW DEGREES ABOVE AVG.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 323 AM CST SAT DEC 6 2014
EARLY CHALLENGE IS THE SYSTEM MOVING INTO THE PACIFIC NW THAT WILL
BRING A GOOD POTENTIAL FOR LIGHT PRECIPITATION...POSSIBLY IN THE
FORM OF A WINTRY MIX...OVER THE AREA SUNDAY NIGHT INTO MONDAY
MORNING. DRY AND NEAR TO BELOW NORMAL TEMPERATURES WILL FOLLOW TUE
AND WED WITH PASSING HIGH PRESSURE. MODEL RUNS OVER THE PAST 24
HOURS HAVE TRENDED TOWARD A MORE AMPLIFIED UPPER LEVEL FLOW NEXT
WEEK RESULTING FROM A DEEPER UPPER LOW NOW DEPICTED OVER THE MID
ATLANTIC COAST AND THE NE U.S. LATE WED THROUGH FRI. THIS
SUGGESTS A LOWER CONFIDENCE LATE WEEK PERIOD WITH EVEN A POTENTIAL
FOR AT LEAST LIGHT PRECIPITATION AS THIS BLOCKING LOW MAY DELAY
THE EASTWARD PROGRESSION OF THE WESTERN U.S. UPPER RIDGE AND KEEP
A MORE ACTIVE...N-NW UPPER LEVEL FLOW IN PLACE OVERHEAD LATER INTO
THE WEEK.
SUNDAY THROUGH MONDAY...THE UPPER LEVEL SYSTEM OFF THE NW COAST IS
EXPECTED TO STRENGTHEN AND THEN PHASE WITH NORTHERN STREAM
ENERGY...DIGGING A LONGWAVE TROUGH OVER THE EASTERN U.S. TOWARD
MID WEEK. AS IT PASSES TO THE NORTH LATE SUNDAY NIGHT...IT
SENDS A ROUND OF MID LEVEL QG FORCING OVER THE FORECAST AREA ABOVE
LOW LEVEL WARM ADVECTION AND MODEST MOISTURE RETURN. TOP DOWN
APPROACH FROM FORECAST SOUNDINGS SUGGESTS A POSSIBLE RAIN/SNOW/SLEET
MIX ACROSS THE NORTHERN HALF OF THE FORECAST AREA...WITH RAIN/SNOW
CENTRAL AND MAINLY RAIN SOUTH...WHICH MAY CHANGE TO PRIMARILY RAIN
OVER ALL BUT THE FAR NORTHEAST WITH WARMING LOW LEVELS TOWARD
MORNING. CONFIDENCE REMAINS LOW IN THE MODEL DEPICTION OF
CRITICAL LOW LEVEL THERMAL PROFILES AND FURTHER ADJUSTMENTS TO
PRECIPITATION TYPES WILL LIKELY BE NEEDED. WITH THE SURFACE LOW
TRACKING WELL TO THE NORTH AND MODEST LIFT...QPF FOR THE EVENT
SHOULD BE LESS THAN A TENTH OF AN INCH WITH LITTLE IF ANY
ACCUMULATION OF SLEET OR SNOW NORTH. WITH THE SYSTEM SLOWING
SOME...HAVE EXTENDED POPS INTO MONDAY MORNING OVER THE EAST FOR
WHAT WOULD LIKELY BE RAIN OR RAIN/SNOW MIX. TEMPERATURES MAY
REACH INTO THE MID 40S IN THE SOUTH BEFORE THE COLD FRONT PUSHES
THROUGH IN THE AFTERNOON.
TUESDAY THROUGH TUE NIGHT...PASSING HIGH PRESSURE RIDGE WILL LIMIT
HIGHS TO THE 30S WITH OVERNIGHT LOWS IN THE UPPER TEENS TO LOWER
20S.
WEDNESDAY THROUGH FRIDAY...THE 00Z GFS...GEM AND ECMWF OFFER VARYING
SOLUTIONS WITH THE TIMING AND TRACK OF THE NEXT SHORTWAVE IN THE NW
FLOW AROUND MID WEEK...AND HOW FAST THE LARGE UPPER LOW EXITS THE
NORTHEAST. THE GFS AND GEM ARE IN ONE CAMP WITH LIGHT PRECIPITATION
DEVELOPING WITH THE NEXT SHORTWAVE IN THE NW FLOW AND ALONG A WARM
FRONT WED INTO WED NIGHT OVER ESPECIALLY THE SOUTH...THEN OVER THE
ENTIRE AREA WED NIGHT...WHEREAS THE ECMWF IS DRY WITH A SURFACE
RIDGE IN PLACE. RESULTING MODEL CONSENSUS BLENDS OF QPF AND POP FIELDS
SUGGESTED SEVERAL PERIODS OF LIGHT PRECIPITATION FROM WED THROUGH
FRI. WITH LOW CONFIDENCE IN THESE PERIODS DUE TO THE POOR
CONSISTENCY AND LACK OF AGREEMENT...HAVE KEPT ONLY SLIGHT CHANCES
FOR WHAT WOULD LIKELY BE LIGHT RAIN CONFINED TO ONLY WED NIGHT.
TEMPERATURES SHOULD STILL MODERATE WITH HIGHS BACK INTO THE 40S
THU AND FRI OVER ESPECIALLY THE SOUTH...BUT THE WELL ADVERTISED
TRANSITION TO MUCH ABOVE NORMAL TEMPERATURES MAY BE DELAYED TO
NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 545 AM CST SAT DEC 6 2014
PATCHY DENSE RADIATION FOG MAY DEVELOP AT KCID AND KDBQ PRIOR TO
15Z TODAY AS STRATUS DECK BEGINS TO BREAK APART AND TEMPS FALL.
CONDITIONS WILL THEN SLOWLY IMPROVE THROUGH THIS MORNING FROM
NORTH TO SOUTH. BY MIDDAY...VFR IS ANTICIPATED AT ALL TERMINALS
EXCEPT KBRL WHERE PERIODS OF IFR/LIFR WILL LIKELY CONTINUE. A
STRONG SUBSIDENCE INVERSION WILL MAKE IT DIFFICULT TO MIX OUT
MOISTURE TRAPPED AROUND 950 MB OR BELOW 1 KFT AGL.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...SHEETS
AVIATION...UTTECH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
400 PM MST SAT DEC 6 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 207 PM MST SAT DEC 6 2014
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW PROGRESSIVE
TROUGH-RIDGE TROUGH PATTERN ACROSS US WITH RIDGE CURRENTLY
EXTENDING FROM SOUTH CENTRAL CANADA ACROSS THE CENTRAL PLAINS. SW
FLOW IS IN PLACE FROM THE FOUR CORNERS REGION AND INTO WESTERN KS
WITH SHORTWAVE TROUGH MOVING OUT OF THE GREAT BASIN TOWARDS THE
CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE OVER
EASTERN COLORADO WITH SOUTHERLY FLOW ACROSS OUR CWA.
AS SHORTWAVE TROUGH TRANSITIONS EASTWARD STATIONARY
FRONT/BAROCLINIC ZONE WITH SHIFT NORTH AND EAST ALLOWING FOR
SOUTHEAST MOISTURE RETURN INTO THE EASTERN HALF OF OUR CWA.
MIDLEVEL MOISTURE/UPPER LEVEL FORCING COULD ALLOW FOR A BRIEF
PERIOD OF LIGHT RAIN SHOWERS LATE TONIGHT...HOWEVER MODEL
SOUNDINGS INDICATE A SIGNIFICANT DRY LAYER WOULD LIKELY PREVENT
ANY ELEVATED PRECIPITATION FROM REACHING THE SURFACE.
MAIN CONCERN WILL BE POTENTIAL FOR DENSE FOG DEVELOPMENT AND
POTENTIAL FOR DRIZZLE ACROSS EASTERN CWA LATE TONIGHT THROUGH
SUNDAY MORNING. NAM/RAP SHOW WEAK SURFACE CONVERGENCE IN PROXIMITY
OF BAROCLINIC ZONE WHICH COULD PROVIDE ENOUGH LIFT WITHIN SHALLOW
SATURATED LAYER TO ALLOW FOR DRIZZLE DEVELOPMENT. THIS COULD BE
MORE OF A STRATUS/DRIZZLE EVENT...THOUGH CONSIDERING THE GOOD
MOISTURE RETURN LOWER VISIBILITIES ARE CERTAINLY POSSIBLE. HIGH
CLOUDS HAVE ALREADY BEEN HAVING AN IMPACT ON MIXING THIS
AFTERNOON...AND WITH THICKENING/LOWERING CLOUDS THOUGH THE NIGHT
(ALONG WITH TD VALUES INCREASING TO MID/UPPER 30S IN THE
EAST)...RADIATIONAL COOLING WILL BE LIMITED. NOT ONLY COULD THIS
LIMIT DENSE FOG DEVELOPMENT...BUT THIS MAKES FREEZING
FOG/FREEZING DRIZZLE UNLIKELY AT THIS POINT. AT THIS POINT HOLDING
OFF ON HIGHLIGHTS SEEMS THE BEST COURSE.
WITH SHIFT BACK TO SW FLOW AS SHORTWAVE RIDGING BUILDS BACK INTO
THE ROCKIES THERE SHOULD BE RAPID IMPROVEMENT IN CONDITIONS
SUNDAY.CLEARING SKIES AND WAA THROUGH THE AFTERNOON SHOULD ALLOW
HIGHS TO WARM TO AROUND 60F...THOUGH STRATUS MAY HOLD ON A LITTLE
LONGER IN OUR EASTERN CWA LIMITING DAYTIME MIXING AND KEEPING
HIGHS IN THE LOW TO MID 50S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 207 PM MST SAT DEC 6 2014
UPPER FLOW WILL BE NORTHWEST SUNDAY NIGHT AHEAD OF A RIDGE THAT WILL
BUILD INTO THE ROCKIES AND PLAINS MONDAY AND TUESDAY. SURFACE HIGH
PRESSURE WILL RESIDE OVER THE PLAINS THROUGH THIS TIME.
DRY CONDITIONS WILL CONTINUE ACROSS THE FA THROUGH TUESDAY.
SUBSIDENCE AND OR A LACK OF SIGNIFICANT FORCING ALONG WITH A LACK OF
LAYER MEAN RH WILL PROVIDE SUPPORT FOR THE DRY CONDITIONS. POPS
WILL BE NIL FROM SUNDAY NIGHT THROUGH TUESDAY.
MIN TEMPERATURES SHOULD BE IN THE MID AND UPPER 20S SUNDAY AND
MONDAY NIGHTS. MAX TEMPERATURES SHOULD RISE TO THE MID 50S MONDAY
AND TUESDAY.
IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)...
THIS PART OF THE FORECAST IS ALSO DRY. A RIDGE WILL RESIDE OVER THE
PLAINS THROUGH THURSDAY AND THEN SHIFT EAST FRIDAY AND SATURDAY WITH
FLOW BECOMING SOUTHWEST. SURFACE HIGH PRESSURE WILL CONTINUE OVER
THE CENTRAL PLAINS THROUGH WEDNESDAY FOLLOWED BY A TROUGH IN
EASTERN COLORADO FROM THURSDAY THROUGH SATURDAY.
MAX TEMPERATURES WILL GENERALLY BE IN THE MID TO UPPER 50S WEDNESDAY
AND SATURDAY. MAX TEMPERATURES THURSDAY AND FRIDAY SHOULD WARM TO
THE UPPER 50S WITH LOWER 60S IN THE WESTERN FA. MIN TEMPERATURES
SHOULD COOL TO THE UPPER 20S AND LOWER 30S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 400 PM MST SAT DEC 6 2014
KGLD...SOUTHEAST WIND AROUND 12KT AT TAF ISSUANCE WITH A SMALL
WINDOW OF 15G23KTS FROM 02Z-05Z UNDER A VFR OVERCAST SKY.
STRATUS/BR REACHES THE TERMINAL FROM THE EAST AROUND 06Z WITH IFR
CIGS EXPECTED FROM 08Z-11Z WITH WINDS FROM THE SOUTH AROUND 10KTS.
AROUND 12Z WINDS VEER TO THE SOUTHWEST 5-10KTS PUSHING THE STRATUS
SLOWLY EAST ALLOWING FOR VFR CONDITIONS TO RETURN. WINDS THEN GO
WEST 5-10KTS AROUND 15Z THEN NORTHWEST 13G21KT IN THE 18Z-22Z
TIMEFRAME UNDER A FEW FAIR WEATHER CUMULUS CLOUDS. GUSTS DISSIPATE
AROUND 23Z WITH A FEW HIGH CLOUDS POSSIBLE.
KMCK...SOUTHEAST WIND 5-10KT AT TAF ISSUANCE UNDER A VFR OVERCAST
SKY. STRATUS/DRIZZLE/BR WITH IFR CONDITIONS REACH THE TERMINAL
FROM THE EAST AROUND 08Z AND CONTINUE THROUGH 17Z BEFORE WINDS
VEER AROUND TO THE NORTHWEST NEAR 10KTS BY 18Z. THIS WILL SCOUR
OUT THE STRATUS PRODUCING VFR CONDITIONS FROM 18Z THROUGH THE REST
OF THE TAF PERIOD.
IT SHOULD BE NOTED THAT IN THESE SCENARIOS THAT HIGH RESOLUTION
MODELS OCCASIONALLY DONT PUSH THE STRATUS FAR ENOUGH WEST...BY AT
LEAST ONE ROW OF COUNTIES. IF THIS VERIFIES STRATUS/BR (POSSIBLY
FG WITH VLIFR CONDITIONS) MAY TAKE UP TO AN ADDITIONAL 3 HOURS TO
MOVE OUT OF BOTH TERMINALS. WITH A THICK OVERCAST SKY HARD TO
WATCH STRATUS PROGRESSION ON SATELLITE IMAGERY SO WILL HAVE TO
WATCH METARS AND RUC/HRRR AND 00Z NAM MODEL DATA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
208 PM MST SAT DEC 6 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 207 PM MST SAT DEC 6 2014
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW PROGRESSIVE
TROUGH-RIDGE TROUGH PATTERN ACROSS US WITH RIDGE CURRENTLY
EXTENDING FROM SOUTH CENTRAL CANADA ACROSS THE CENTRAL PLAINS. SW
FLOW IS IN PLACE FROM THE FOUR CORNERS REGION AND INTO WESTERN KS
WITH SHORTWAVE TROUGH MOVING OUT OF THE GREAT BASIN TOWARDS THE
CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE OVER
EASTERN COLORADO WITH SOUTHERLY FLOW ACROSS OUR CWA.
AS SHORTWAVE TROUGH TRANSITIONS EASTWARD STATIONARY
FRONT/BAROCLINIC ZONE WITH SHIFT NORTH AND EAST ALLOWING FOR
SOUTHEAST MOISTURE RETURN INTO THE EASTERN HALF OF OUR CWA.
MIDLEVEL MOISTURE/UPPER LEVEL FORCING COULD ALLOW FOR A BRIEF
PERIOD OF LIGHT RAIN SHOWERS LATE TONIGHT...HOWEVER MODEL
SOUNDINGS INDICATE A SIGNIFICANT DRY LAYER WOULD LIKELY PREVENT
ANY ELEVATED PRECIPITATION FROM REACHING THE SURFACE.
MAIN CONCERN WILL BE POTENTIAL FOR DENSE FOG DEVELOPMENT AND
POTENTIAL FOR DRIZZLE ACROSS EASTERN CWA LATE TONIGHT THROUGH
SUNDAY MORNING. NAM/RAP SHOW WEAK SURFACE CONVERGENCE IN PROXIMITY
OF BAROCLINIC ZONE WHICH COULD PROVIDE ENOUGH LIFT WITHIN SHALLOW
SATURATED LAYER TO ALLOW FOR DRIZZLE DEVELOPMENT. THIS COULD BE
MORE OF A STRATUS/DRIZZLE EVENT...THOUGH CONSIDERING THE GOOD
MOISTURE RETURN LOWER VISIBILITIES ARE CERTAINLY POSSIBLE. HIGH
CLOUDS HAVE ALREADY BEEN HAVING AN IMPACT ON MIXING THIS
AFTERNOON...AND WITH THICKENING/LOWERING CLOUDS THOUGH THE NIGHT
(ALONG WITH TD VALUES INCREASING TO MID/UPPER 30S IN THE
EAST)...RADIATIONAL COOLING WILL BE LIMITED. NOT ONLY COULD THIS
LIMIT DENSE FOG DEVELOPMENT...BUT THIS MAKES FREEZING
FOG/FREEZING DRIZZLE UNLIKELY AT THIS POINT. AT THIS POINT HOLDING
OFF ON HIGHLIGHTS SEEMS THE BEST COURSE.
WITH SHIFT BACK TO SW FLOW AS SHORTWAVE RIDGING BUILDS BACK INTO
THE ROCKIES THERE SHOULD BE RAPID IMPROVEMENT IN CONDITIONS
SUNDAY.CLEARING SKIES AND WAA THROUGH THE AFTERNOON SHOULD ALLOW
HIGHS TO WARM TO AROUND 60F...THOUGH STRATUS MAY HOLD ON A LITTLE
LONGER IN OUR EASTERN CWA LIMITING DAYTIME MIXING AND KEEPING
HIGHS IN THE LOW TO MID 50S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 207 PM MST SAT DEC 6 2014
UPPER FLOW WILL BE NORTHWEST SUNDAY NIGHT AHEAD OF A RIDGE THAT WILL
BUILD INTO THE ROCKIES AND PLAINS MONDAY AND TUESDAY. SURFACE HIGH
PRESSURE WILL RESIDE OVER THE PLAINS THROUGH THIS TIME.
DRY CONDITIONS WILL CONTINUE ACROSS THE FA THROUGH TUESDAY.
SUBSIDENCE AND OR A LACK OF SIGNIFICANT FORCING ALONG WITH A LACK OF
LAYER MEAN RH WILL PROVIDE SUPPORT FOR THE DRY CONDITIONS. POPS
WILL BE NIL FROM SUNDAY NIGHT THROUGH TUESDAY.
MIN TEMPERATURES SHOULD BE IN THE MID AND UPPER 20S SUNDAY AND
MONDAY NIGHTS. MAX TEMPERATURES SHOULD RISE TO THE MID 50S MONDAY
AND TUESDAY.
IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)...
THIS PART OF THE FORECAST IS ALSO DRY. A RIDGE WILL RESIDE OVER THE
PLAINS THROUGH THURSDAY AND THEN SHIFT EAST FRIDAY AND SATURDAY WITH
FLOW BECOMING SOUTHWEST. SURFACE HIGH PRESSURE WILL CONTINUE OVER
THE CENTRAL PLAINS THROUGH WEDNESDAY FOLLOWED BY A TROUGH IN
EASTERN COLORADO FROM THURSDAY THROUGH SATURDAY.
MAX TEMPERATURES WILL GENERALLY BE IN THE MID TO UPPER 50S WEDNESDAY
AND SATURDAY. MAX TEMPERATURES THURSDAY AND FRIDAY SHOULD WARM TO
THE UPPER 50S WITH LOWER 60S IN THE WESTERN FA. MIN TEMPERATURES
SHOULD COOL TO THE UPPER 20S AND LOWER 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1004 AM MST SAT DEC 6 2014
VFR CONDITIONS WILL PERSIST AT KGLD AND KMCK AT LEAST THROUGH
08Z. AFTER 08Z LOW LEVEL MOISTURE WILL BEGIN TO ADVECT NORTH AND
EAST WITH LOW STRATUS...FOG...AND POSSIBLY DRIZZLE SPREADING INTO
KMCK. KGLD LOOKS TO BE FAR ENOUGH WEST THAT CONDITIONS SHOULD
REMAIN VFR THROUGH THE TAF PERIOD. IFR CIGS APPEAR
LIKELY...HOWEVER THE CUTOFF OF POTENTIAL DENSE FOG/DRIZZLE IS
DEPICTED VERY CLOSE TO KMCK TERMINAL. ITS TOO EARLY WITH LIMITED
CONFIDENCE TO ADD LOWER CONDITIONS TO KMCK AT THIS POINT...BUT I
PLAN ON KEEPING IFR CIG AND MVFR VIS GROUP IN THE 10-15Z PERIOD.
GUSTY WINDS AT KGLD WILL DIMINISH AROUND SUNSET TODAY...WITH WINDS
AT BOTH TERMINALS REMAINING BELOW 12KT THROUGH THE REST OF THE TAF
PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1156 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION INTO THIS EVENING. HIGH PRESSURE WILL
GIVE A DRY DAY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID MORNING UPDATE TO SLOW TIMING FOR RAIN TO END BASED ON LATEST
RADAR TRENDS AND INCOMING 12Z MODELS. STILL A CHANCE FOR SLEET TO
MIX IN FAR NORTH THIS AFTERNOON BUT NOTHING OF CONSEQUENCE. HOURLY
TEMPERATURES AND WINDS ADJUSTED TOWARD NEWEST LAMP GUIDANCE. WINDS
WERE INCREASED ESPECIALLY THIS EVENING AS SURFACE LOW PUSHES EAST.
PREVIOUS BELOW.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV THROUGH THAT
TROF IS CURRENTLY PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD
PROGRESS OF WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO
FOREGO PROBLEM CONTRIBUTION FOR THE UPR OH REGION.
NEVERTHELESS...PCPN CHCS WL INCRS ON MON NGT INTO TUESDAY AS
ISENTROPIC LIFT...WARM MOIST ADVCTN DVLPS ON THE ERN FLANKS OF THE
HIGH AMPLITUDE ERN CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A DEEP ERN CONUS TROF IS PROGGED TO PERSIST THRU ERLY INTO THE
WKEND AS COASTAL SFC LOW PRES TRACKS UP THE E COAST. FCST SNW
SHWR CHCS INTO WED NGT UNTIL THE LOW AND UPR SPPRT EXITS THE RGN.
A WK SRTWV IS PROGGED TO ROTATE THRU THE GT LKS ARND THE MAIN TROF
FRI THOUGH WITH BLDG SFC HIGH PRES UNDER THE TROF KEPT A DRY FCST.
BLO SEASONAL TEMPS SHOULD RTN TO NR AVG BY LT WK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
LATEST OBSERVATIONS BEGINNING TO SHOW IFR CONDITIONS IMPROVING TO
MVFR ACROSS WESTERN OHIO WHERE WINDS ALOFT VEER TO THE
WEST/NORTHWEST BEHIND THE AXIS OF THE MID-LEVEL TROUGH PASSING
ACROSS THE REGION. WINDS WILL INCREASE AND BE GUSTY THROUGH MID
AFTERNOON AS THE TROUGH PASSES THROUGH AND THE BOUNDARY LAYER
DEEPENS...TAPPING STRONGER WINDS ALOFT. WINDS GUSTS WILL RANGE
BETWEEN 15 AND 20KTS ON AVERAGE. MID AND UPPER LEVELS WILL QUICKLY
DRY OUT BEHIND THE TROUGH CLEARING OUT MID AND UPPER LEVEL CLOUDS
FROM WEST TO EAST STARTING LATER THIS AFTERNOON. THIS TREND WILL
CONTINUE TONIGHT AS HIGH PRESSURE BUILDS IN...WITH DRY CONDITIONS
AND LIMITED CLOUD COVERAGE EXPECTED ON SUNDAY.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RESTRICTIONS ARE ANTICIPATED ON TUESDAY AS THE NEXT FRONTAL SYSTEM
TRANSITIONS OVER THE AREA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
314 PM CST Sat Dec 6 2014
.SHORT TERM: (Through Late Tonight)
Issued at 300 PM CST Sat Dec 6 2014
Low stratus located within the southern portion of a large high
pressure system continues to dominate the region at mid afternoon.
There has been a slow clearing trend to our north with the clearing
line located near the MO/IA border into northern IL. This high
pressure system will dominate tonight as it moves to the east with
low level flow gradually veering to easterly by mid evening and
then east-southeasterly overnight. Given the trends in the wind
field, there will probably be additional southward clearing into
the early evening then the northern edge will hold steady before
retreating back northwest overnight. The RAP H950 RH is the only
guidance that seems to have a decent handle on this evolution. The
abundance of clouds tonight would suggest MOS guadance is too low
on mins, with the coolest values expected across northeast MO and
west central IL.
Glass
.LONG TERM: (Sunday through Next Saturday)
Issued at 300 PM CST Sat Dec 6 2014
The high pressure system will continue to retreat on Sunday and
this will keep low clouds prevalent. Add in high clouds and it will
make for a mostly cloudy-cloudy day. There are some indications that
southern portions of the CWA could see some clearing from the
south of the low clouds, and hence warmer high temps are expected.
The next threat of precipitation will come Sunday night into
Monday morning. A short wave trof will dig into the mid-upper MS
valley. The large scale ascent associated with this wave along
increasing mid level moisture and low level warm advection should
be sufficient to generate some spotty/scattered precipitation
ahead of the attendant cold front. Temperature profiles indicate
the precipitation should be in the form of rain, with the highest
pops late Monday night across northeast MO and along and east of
the MS River on Monday morning. Monday should be milder with
decreasing clouds as first a prefrontal trof and then the cold
front then sweeps through the area. Another brief round of cold
air then dominates on Tuesday with expansive high pressure.
The upper air pattern will be in transition during the extended
period from Wednesday into next weekend. The eastern U.S. upper
trof/low will be progressive lifting northeast and eventually off
the Atlantic Seaboard. A northwest flow short wave in the wake of
the slowly retreating trof looks to impact our area sometime late
Wednesday into early Thursday, however present indications are any
precipitation threat should be confined to western MO. Heights
aloft then gradually rise in the wake of the shortwave trof and
high pressure departs, leading to southerly low level flow Friday
into the Saturday and a warming trend.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1147 AM CST Sat Dec 6 2014
Should see slow improvement in visibilities this afternoon but
only a slight gradual rise in ceiling heights, except at UIN where
the southward advancing clearing line across southern IA and
northwestern IL may make it to by late afternoon or early evening.
Elsewhere ceiling heights will likely only improve to around
1000 feet late this afternoon, then drop some late tonight along
with the redevelopment of at least light fog. Status clouds will
likely redevelop or advect back into UIN late tonight as the
surface/low level flow becomes easterly. For now will keep it
scattered in the UIN TAF tonight, but this may be too optimistic.
There should be more substantial improvement in the ceiling
heights at the other taf sites by late Sunday morning, possibly
into the MVFR catagory. Nly surface wind will gradually veer
around to an ely direction tonight, and a sely direction Sunday
morning as the surface ridge extending from MN southwest into the
TX panhandle moves eastward through our area.
Specifics for KSTL: The visibilities should become unrestricted by
late afternoon, but the ceiling height may only rise to around
1000 feet. The ceiling height may lower some late tonight along
with the redevelopment of at least light fog. Should see more
improvement on Sunday, possibly going VFR in the afternoon. Nly
surface wind will veer around to a nely direction this evening,
then to a sely direction by late Sunday morning.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
333 PM CST SAT DEC 6 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 333 PM CST SAT DEC 6 2014
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE POSSIBLE
FREEZING PRECIPITATION TONIGHT AND SUNDAY.
CURRENTLY A SHORTWAVE TROUGH IS LOCATED OVER EASTERN WASHINGTON. THE
WAVE WILL TRACK ALONG THE INTERNATIONAL BORDER OVERNIGHT AND DEVELOP
A SURFACE LOW IN THE LEE OF THE ROCKIES. THE SURFACE/UPPER LEVEL LOW
IS PROGGED TO BE OVER NORTHEAST MT/SOUTH CENTRAL SK BY 12 UTC
SUNDAY. WARM ADVECTION AHEAD OF THE LOW WILL RESULT IN WARM
TEMPERATURES ALOFT ENCOMPASSING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA TONIGHT. THUS THE POTENTIAL FOR FREEZING PRECIPITATION
THROUGH SUNDAY AFTERNOON.
THE LATEST 20 UTC RAP DEPICTS A BAND OF LIGHT REFLECTIVITIES MOVING
INTO WESTERN NORTH DAKOTA AROUND 08 UTC SUNDAY. HOWEVER...ANY
MEASURABLE PRECIPITATION REMAINS CONFINED TO THE FAR NORTHWEST
CORNER OF NORTH DAKOTA. THE RAP MAINTAINS THE LIGHT REFLECTIVITIES
AS THEY CROSS THE CWA BUT KEEPS MAINLY TRACE AMOUNTS...AND MAINLY
CONFINED TO THE FAR NORTHERN TIER COUNTIES. THE GFS/EC/GEM ALL
BRING VERY LIGHT QPF INTO THE FAR NORTHWEST THROUGH 12 UTC. THE
EC/GEM ALSO TRACK SOME TRACE AMOUNTS ALONG THE NORTHERN TIER
COUNTIES THROUGH THE MORNING. THE GFS IS FARTHER SOUTH AND IS ON
THE SOUTHERN SIDE OF THE ENVELOPE OF DETERMINISTIC SOLUTIONS. THUS
HAVE KEPT BEST CHANCE FOR QPF IN THE FAR NORTHWEST 06-12 UTC
SUNDAY AND ACROSS THE FAR NORTHERN TIER COUNTIES 12-18 UTC SUNDAY.
WILL STILL HAVE A MENTION OF SOME FREEZING RAIN SOUTHWEST AND
SOUTH CENTRAL (MAINLY ALONG AND NORTH OF I-94) BUT WITH NO
SIGNIFICANT ACCUMULATIONS. EVEN ACROSS THE NORTH...DETERMINISTIC
MODEL QPF REMAINS AT OR BELOW A HUNDREDTH OF AN INCH. ONLY A
LITTLE FREEZING RAIN CAN CAUSE SIGNIFICANT TRAVEL ISSUES. BUT WITH
LOW MODEL QPF...WILL HOLD OFF ON ANY HIGHLIGHTS AT THIS TIME. WE
WILL STILL HAVE TIME TO WATCH THINGS DEVELOP ACROSS NORTHEAST
MONTANA AND SOUTHERN SASKATCHEWAN THIS EVENING AND OVERNIGHT.
COULD STILL SEE A VERY LIGHT MIX OVER THE NORTH CENTRAL MONDAY
AFTERNOON. BUT WESTERN NORTH DAKOTA WILL BE ON THE BACK SIDE OF THE
MID LEVEL TROUGH WITH COLD ADVECTION TRACKING SOUTHEAST ACROSS THE
CWA DURING THE AFTERNOON. THUS THE WEST WILL QUICKLY TRANSITION TO
SNOW AND THE SOUTH CENTRAL SHOULD WARM UP ENOUGH TO SEE ALL RAIN
WITH A QUICK CHANGE TO SNOW AS THE COLD ADVECTION ARRIVES.
IT WILL ALSO BECOME BREEZY TO WINDY SUNDAY AFTERNOON FROM WEST TO
EAST BEHIND THE TRACK OF THE LOW. STRONGEST WINDS 20-30 MPH WITH
GUSTS TO 35 MPH WILL SPREAD FROM THE SOUTHWEST SUNDAY AFTERNOON INTO
THE CENTRAL LATE AFTERNOON TO EARLY EVENING. HIGHS SUNDAY WILL
LIKELY BE REACHED IN THE MORNING NORTH TO EARLY AFTERNOON SOUTH WITH
TEMPERATURES FALLING MID TO LATE AFTERNOON EVERYWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM CST SAT DEC 6 2014
POST FRONTAL NORTHWEST WINDS OF 20 TO 30 MPH ALONG WITH ISOLATED TO
SCATTERED SNOW SHOWERS WILL DOMINATE SUNDAY NIGHT. THE ENTIRE SYSTEM
DEPARTS CENTRAL NORTH DAKOTA BY 12Z MONDAY WITH COLDER AIR REMAINING
IN PLACE FOR THE MORNING FOLLOWED BY WARM AIR ADVECTION MONDAY
AFTERNOON ESPECIALLY IN THE WEST. A PROGRESSIVE PATTERN CONTINUES
WITH A TRANSITORY RIDGE SHIFTING THROUGH MONDAY NIGHT FOLLOWED BY A
DRY SHORTWAVE TROUGH PASSING THROUGH TUESDAY. THEREAFTER...UPPER
RIDGING DOMINATES AND SHIFTS EAST BY MIDWEEK ALLOWING A SOUTHWEST
FLOW TO RETURN. HOWEVER NOTHING FORESEEN IN THE SOUTHWEST FLOW IN
TERMS OF SIGNIFICANT SHORTWAVES AT LEAST THROUGH SATURDAY PER
GFS/GEM GLOBAL/SUPERBLEND. HOWEVER THE LATEST ECMWF PUSHES A FAST
MOVING SHORTWAVE AND CONSEQUENTLY LIGHT PRECIPITATION/FAVORING RAIN
SHOWERS AT THIS POINT...ACROSS THE NORTH THURSDAY. HIGH TEMPERATURES
WILL WARM TO BETWEEN 35F AND 45F WEDNESDAY THROUGH FRIDAY...THEN A
BIT COOLER FOR SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 333 PM CST SAT DEC 6 2014
VFR CONDITIONS THIS AFTERNOON AND TONIGHT. A LOW PRESSURE SYSTEM
WILL MOVE INTO THE AREA BY SUNDAY MORNING. COULD SEE A VERY BRIEF
PERIOD OF FREEZING RAIN AHEAD OF THE SYSTEM. ALTHOUGH WITH ONLY
SLIGHT CHANCES...WILL NOT ADD THE FZRA TO THE TAFS. SUNDAY WINDS
WILL SHIFT WEST TO NORTHWEST AND INCREASE...WITH INCREASING MVFR
CLOUDS AND A CHANCE OF SNOW SHOWERS...BUT MAINLY AFTER 18 UTC.
WILL BRING A SCATTERED MVFR LAYER INTO THE WEST AND NORTH LATE IN
THE FORECAST PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TWH
LONG TERM...KS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1249 PM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1249 PM CST SAT DEC 6 2014
CLOUDS CONTINUE OVER MUCH OF THE REGION...WITH THE WESTERN EDGE OF
THE DECK NOT MOVING INTO OUR CWA UNTIL LATE AFTERNOON. MADE ONLY A
FEW MINOR TWEAKS TO CLOUDS. THERE CONTINUE TO BE A FEW RADAR
RETURNS OVER THE REGION...BUT NOTHING IS REACHING THE GROUND AND
ONLY MID LEVEL CLOUDS HAVE BEEN REPORTED. WILL LET FLURRY MENTION
GO AWAY FOR THE AFTERNOON AS PLANNED. WILL CONTINUE TO KEEP TEMPS
CLIMBING INTO THE 20S AS EVEN WITH CLOUDS WE ARE UPPER TEENS TO
LOW 20S AT THE CURRENT HOUR.
UPDATE ISSUED AT 950 AM CST SAT DEC 6 2014
CLOUDS CONTINUE TO SPREAD ACROSS THE CWA AS SEEN ON SATELLITE AND
WEB CAMS...SO INCREASED CLOUD COVER FOR MUCH OF THE DAY. WE COULD
START SEEING SOME BREAKS IN THE WEST LATE AS THE EDGE OF THE CLOUD
DECK APPROACHES. THERE HAS BEEN A FEW FLURRIES REPORTED NEAR THE
WESTERN CWA BORDER SO INCLUDED AN ISOLATED MENTION THROUGH THE
NEXT FEW HOURS. LOWERED HIGHS A DEGREE OR SO WITH INCREASED
CLOUDS...BUT STILL THINK WE SHOULD GET INTO THE 20S.
UPDATE ISSUED AT 655 AM CST SAT DEC 6 2014
THERE HAS BEEN PATCHY DENSE FOG DEVELOP OVER THE PAST FEW
HOURS...BUT QUICKLY DISSIPATE ONCE MID-HIGH CLOUDS COME OVERHEAD.
THE ONLY UPDATE IS FOR THE SKY GRID TO ACCOUNT FOR MID-LEVEL
CLOUDS SPREADING OVER THE REGION A BIT FASTER THAN ANTICIPATED
(FOLLOWED THE RAP 700MB RH FIELD).
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
FREEZING RAIN POTENTIAL ON SUNDAY WILL BE THE MAIN CONCERN FOR
THIS PERIOD. 00Z MODELS IN DECENT AGREEMENT...ALTHOUGH DIFFERENCES
IN THERMAL PROFILES WILL MAKE FOR A CHALLENGING FORECAST.
HIGH PRESSURE PROPAGATES ACROSS THE REGION TODAY WITH SOUTHERLY
RETURN FLOW SETTING UP THIS AFTERNOON. SATELLITE IMAGERY AND
OBSERVATIONS INDICATE PATCHY FOG DEVELOPING...AND WILL NEED TO
MONITOR (DID INCLUDE PATCHY FOG IN THE FORECAST FOR SOME
LOCATIONS). WEAK SYSTEM WILL BE PROPAGATING ACROSS SOUTHERN CANADA
TODAY...AND ALTHOUGH THE STRONGEST FORCING WILL BE NORTH OF THE
INTERNATIONAL BORDER...DO EXPECT AN AREA OF CLOUDS TO MOVE
THROUGH THE REGION. THE TEMPERATURE FORECAST IS A BIT TRICKY. MOST
AREAS SHOULD BE ABLE TO RISE INTO THE 20S THIS AFTERNOON...THEN
AFTER A BRIEF DIP IN VALUES...STRONGER WARM AIR ADVECTION
COMMENCES TONIGHT AND ANTICIPATE SLOWLY RISING VALUES.
MAJORITY OF MODEL GUIDANCE IS INDICATING A STRONGER SIGNAL FOR
FREEZING RAIN SUNDAY MORNING...ESPECIALLY THE SOUTHERN VALLEY INTO
WEST CENTRAL MINNESOTA AND PORTIONS OF NORTHWEST MINNESOTA (MAINLY
ALONG AND EAST OF A LINE FROM WAHPETON TO BAUDETTE). QPF AMOUNTS
LIKELY AROUND 0.10 INCHES. THE GENERAL IDEA IS THAT EVAPORATIVE
COOLING WILL TRANSITION A FREEZING RAIN/SLEET MIX TO SNOW...BUT
GIVEN THE SREF P-TYPE PROBABILITIES (VERY HIGH FREEZING RAIN
PROBABILITIES)...THE THOUGHT IS THAT THE OPERATIONAL MODELS MAY
BE EVAPORATIVELY COOLING TOO QUICKLY (WHICH DOES HAPPEN) AND/OR
TOO DRY ALOFT. IF CONFIDENCE INCREASES IN THE EXPECTED THERMAL
PROFILE...ALONG WITH SFC TEMPERATURES REMAINING BELOW
FREEZING...SOME SORT OF ADVISORY MAY BE NEEDED FOR THIS AREA.
OTHERWISE...AREAS TO THE WEST WILL LIKELY BE WELL INTO THE 30S ON
SUNDAY AND MOSTLY DRY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
SUNDAY NIGHT-MONDAY NIGHT...DEFORMATION ZONE SNOW SHOWERS SUNDAY
NIGHT INTO THE EARLY PORTIONS OF MONDAY AS THE SYSTEM FROM THE
SHORT TERM PERIOD MOVES AWAY FROM THE REGION. HIGH PRESSURE BUILDS
INTO THE REGION BY LATER MONDAY. ANTICIPATE A COLDER AIRMASS WITH
TEMPERATURES NEAR NORMAL (THE HIGHS ON MONDAY MAY OCCUR IN THE
MORNING).
TUESDAY-FRIDAY...EXTENDED PERIOD BEGINS UNDER NORTHWEST FLOW AND
NEAR AVERAGE TEMPERATURES FOR THE FIRST HALF OF DECEMBER.
AFTERWARDS GUIDANCE DIFFERS ON TIMING AND PLACEMENT OF SHORT WAVE
ENERGY RIDING THROUGH UPPER RIDGE DURING THE MIDDLE OF THE WEEK.
ECMWF PREFERS TO KEEP WAVE OVER SOUTHERN CANADA WHILE GFS IS
FARTHER SOUTH CLOSER TO THE NORTHERN/CENTRAL PLAINS INTERFACE. GFS
IS TYPICALLY A BIT FASTER WITH THIS FEATURE AND THE WEAK SHORT
WAVE IS NOT EXPECTED TO HAVE A GREAT IMPACT ON FORECAST. THE EARLY
PERIOD AVERAGE TEMPERATURES WILL BEGIN TO WARM FROM WEDNESDAY
THROUGH FRIDAY AS RETURN FLOW/WARM ADVECTION INCREASES WITH A
SHORT WAVE RIDGE BUILDING INTO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1249 PM CST SAT DEC 6 2014
MID-LEVEL VFR CLOUD DECK IN THE 5-8 KFT RANGE WILL CLEAR FROM WEST
TO EAST LATE THIS AFTERNOON AND EVENING...WITH HIGH CIRRUS STREAMING
IN FROM THE WEST BY LATE TODAY. AS SFC LOW PRESSURE TO THE WEST
APPROACHES...SOUTH/SOUTHEAST WINDS WILL STRENGTHEN THIS
EVENING...PERHAPS A BIT GUSTY AT TIMES...DESPITE SHALLOW VERTICAL
MIXING. MOISTURE WILL SPREAD NORTHWARD BY EARLY SUNDAY...LIKELY
SPREADING LOW CLOUDS INTO THE REGION. FOR NOW TRENDED TO MVFR...BUT
BASED ON CURRENT OBS TO THE SOUTH AND MODEL GUIDANCE...IFR
CONDITIONS CERTAINLY A GOOD POSSIBILITY WITH PERHAPS SOME REDUCED
VSBYS AS WELL. EXACT TIMING OF ARRIVAL OF THE LOWER CEILINGS AT EACH
SITE REMAINS SOMEWHAT UNCERTAIN. SOME LIGHT SLEET/FZRA MAY AFFECT
ESPECIALLY KBJI BY LATE IN THE TAF PERIOD...WITH LOWER CONFIDENCE IN
PRECIP WESTWARD AT KFAR...KTVF...AND KGFK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...MAKOWSKI
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
316 PM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WAVE PASSES WITH COLDER AIR IN ITS WAKE TONIGHT.
HIGH PRESSURE SUNDAY. UPPER TROUGH MONDAY NIGHT/TUESDAY. COLDER
AIR TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 18Z THE FRONT HAS CLEARED CRW AND CKB WITH SURFACE LOW E OF
EKN. FRONT WILL CLEAR THE MOUNTAINS BY 21Z. AS THE FRONT
CROSSES...TEMPERATURE FALLS OF 7 TO 10 DEGREES CAN BE EXPECTED
WITH GRADUALLY LOWERING TEMPS THEREAFTER THROUGH THE EVENING. LOW
CIGS AND VSBY IN POST FRONTAL DZ CAN BE EXPECTED THRU THE
REMAINDER OF THE AFTERNOON...ALONG WITH GUSTY NW WINDS. WILL WATCH
-RA TO FILL BACK IN LATER THIS AFTERNOON AS THE UPPER LEVEL TROF
CROSSES. AREA WILL BEGIN TO DRY OUT WITH PASSAGE OF THE UPPER
LEVEL TROF...SAVE FOR SOME DZ HANGING ON ACROSS THE MOUNTAINS THIS
EVENING. ELECTED TO KEEP POSSIBILITY OF IT ENDING AS A LITTLE FRZ
DZ BUT NOT EXPECTING ANY IMPACTS.
WHAT WILL NOT CLEAR OUT THIS EVENING IS THE LOW STRATUS.
HOWEVER...DO EXPECT BASES TO LIFT A BIT TONIGHT. THINK SE OH WILL
SCT OUT DURING THE PREDAWN. HOWEVER...DEVELOPING SUBSIDENCE
INVERSION BENEATH THIS LINGERING MOISTURE WILL MAKE IT VERY
DIFFICULT FOR STRATUS TO BREAK UP E OF THE OH RIVER OVERNIGHT. WITH WEAK
CAA BENEATH THE INVERSION AND LOW LEVEL WINDS BECOMING MORE
NE...FELT IT NECESSARY TO HOLD THE STRATUS IN ALONG THE
CLIMATOLOGICAL FAVORED AREAS IN THIS SETUP....IE THE C LOWLANDS
AND COAL FIELDS THRU THE MORNING HOURS. CLOUDS WILL GRADUALLY SCT
OUT FROM NE TO SW...WITH AREAS ALONG AND S OF I64 CORRIDOR THE
LAST TO LOSE THE STRATUS...POSSIBLY HOLDING ON UNTIL LATE
AFTERNOON.
FOR TEMPS...USED A BLEND OF LAMP AND HRRR FOR TEMPS TONIGHT. FOR
SUNDAY...USED MET AS A BASE WHICH BETTER REFLECTED EXPECTED COOLER
READINGS ALONG AND ESPECIALLY S OF I64 CORRIDOR DUE TO CLOUDS.
FURTHER N...FELT LOCAL MOS WAS THE WAY TO GO WHERE READINGS SHOULD
REACH INTO THE MID OR UPPER 40S.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
STRONG MID LEVEL RIDGING AND HIGH PRESSURE INFLUENCES FROM EASTERN
CANADA DOMINATE SUNDAY...BUT SUNSHINE STILL LIMITED TO THE MORNING
HOURS WITH CIRRUS AHEAD OF THE UPPER LEVEL TROUGH DIGGING IN OVER
THE WESTERN GREAT LAKES. MODELS NOW SETTLING ON THE TROUGH AXIS
HOLDING THE DEVELOPING COASTAL SYSTEM OFFSHORE AND MAINLY AWAY FROM
OUR EASTERN MOST RIDGES...BUT WILL STILL ENTERTAIN SOME LOW END POPS
FOR THE FAR EASTERN PORTIONS OF RAND/POCA COUNTIES. SOME ICING IS
POSSIBLE IN THE SOUTHEAST UPSLOPE AREAS.
HAVE THE TRANSITION TO SNOW FOR THE LOWLAND UPSLOPE AREAS FROM RAIN
TO SNOW A BIT SLOWER...AND JUST BEGINNING BY THE END OF THE SHORT
TERM FORECAST AT 00Z WEDNESDAY. 925MB TEMPERATURES GO BELOW 0C JUST
AFTER 21Z TUESDAY FOR THE MOUNTAINS...MAKING THE 18Z TO 00Z PERIOD
THE RAIN/SNOW TRANSITION TIMES FOR THE MOUNTAINOUS AREAS. LOWLANDS
WILL TRANSITION TO SNOW LIKELY IN THE BEGINNING FEW HOURS OF THE
LONG TERM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
USED A BLEND OF THE GFS...GEFS MEAN...ECMWF...ECMWF MEAN...AND
CONTINUITY WITH THE PREVIOUS FORECAST. THIS WOULD HAVE WRAP AROUND
MOISTURE OVER THE REGION FOR TUESDAY NIGHT INTO WEDNESDAY. 850 MB
TEMPERATURES ARE MARGINAL FOR UPSLOPE SNOW...SO COULD SEE DRIZZLE
INSTEAD OF SNOW IN MANY AREAS. A HIGH PRESSURE SYSTEM THEN MOVES IN
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...ALLOWING
TEMPERATURES TO MODERATE SOME.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
SURFACE FRONT WAS E OF CRW/CKB AS OF 18Z. EXPECT IT TO CROSS KEKN
AND KBKW BY 20Z. CIGS AND VSBY WILL LOWER INTO IFR OR WORSE FOR A
TIME IN POST FRONTAL DZ ACROSS MUCH OF THE AREA. WINDS WILL ALSO
GUST IN THE 15 TO 20 KT RANGE...A BIT HIGHER WITH ACTUAL FROPA.
ANOTHER ROUND OF SHRA POSSIBLE LATER THIS AFTERNOON AND INTO THE
EARLY EVENING HRS WITH THE PASSAGE OF THE UPPER LEVEL TROF.
ALLOWED TO VSBY TO IMPROVE INTO MVFR AND EVENTUAL VFR OVERNIGHT AS
DRIER AIR ADVECTS IN NEAR THE SURFACE. ALSO ALLOWED CIGS TO LIFT A
BIT INTO MVFR...FOLLOWING PASSAGE OF THE UPPER TROF. STILL HAVE
CIGS BELOW 2 GRAND MARK THOUGH.
THE LOW STRATUS SHOULD SCT OUT ACROSS SE OH OVERNIGHT...BUT WILL
HANG TOUGH E OF THE OH RIVER TO AFFECT THE TAF SITES. THE LOW
LEVEL FLOW WILL BECOME MORE NE OVERNIGHT WITH SOME GUSTS
CONTINUING. THIS COMBINED WITH DEVELOPING SUBSIDENCE INVERSION
WILL KEEP THE LOW STRATUS IN PLACE FIRST HALF OF SUNDAY...WITH
KCRW AND KHTS PERHAPS NOT SCT OUT UNTIL AFTER END OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS MAY VARY.
TIMING ERADICATION OF LOW STRATUS MAY VARY...POSSIBLY OCCURRING
MUCH SOONER THAN CURRENTLY FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H M M H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H M M L L L L H H M
EKN CONSISTENCY H L L L L L L L L L L M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H M M H H H H H M M M M
AFTER 18Z SUNDAY...
IFR POSSIBLE IN RAIN/SNOW MONDAY NIGHT INTO WEDNESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30/26
NEAR TERM...30
SHORT TERM...26
LONG TERM...RPY
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
149 PM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WAVE PASSES WITH COLDER AIR IN ITS WAKE TONIGHT.
HIGH PRESSURE SUNDAY. LOW PRESSURE ALONG MID ATLANTIC COAST MONDAY
NIGHT. COLD FRONT TUESDAY WITH COLDER AIR TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 18Z THE FRONT HAS CLEARED CRW AND CKB WITH SURFACE LOW E OF
EKN. FRONT WILL CLEAR THE MOUNTAINS BY 21Z. AS THE FRONT
CROSSES...TEMPERATURE FALLS OF 7 TO 10 DEGREES CAN BE EXPECTED
WITH GRADUALLY LOWERING TEMPS THEREAFTER THROUGH THE EVENING. LOW
CIGS AND VSBY IN POST FRONTAL DZ CAN BE EXPECTED THRU THE
REMAINDER OF THE AFTERNOON...ALONG WITH GUSTY NW WINDS. WILL WATCH
-RA TO FILL BACK IN LATER THIS AFTERNOON AS THE UPPER LEVEL TROF
CROSSES. AREA WILL BEGIN TO DRY OUT WITH PASSAGE OF THE UPPER
LEVEL TROF...SAVE FOR SOME DZ HANGING ON ACROSS THE MOUNTAINS THIS
EVENING. ELECTED TO KEEP POSSIBILITY OF IT ENDING AS A LITTLE FRZ
DZ BUT NOT EXPECTING ANY IMPACTS.
WHAT WILL NOT CLEAR OUT THIS EVENING IS THE LOW STRATUS.
HOWEVER...DO EXPECT BASES TO LIFT A BIT TONIGHT. THINK SE OH WILL
SCT OUT DURING THE PREDAWN. HOWEVER...DEVELOPING SUBSIDENCE
INVERSION BENEATH THIS LINGERING MOISTURE WILL MAKE IT VERY
DIFFICULT FOR STRATUS TO BREAK UP E OF THE OH RIVER OVERNIGHT. WITH WEAK
CAA BENEATH THE INVERSION AND LOW LEVEL WINDS BECOMING MORE
NE...FELT IT NECESSARY TO HOLD THE STRATUS IN ALONG THE
CLIMATOLOGICAL FAVORED AREAS IN THIS SETUP....IE THE C LOWLANDS
AND COAL FIELDS THRU THE MORNING HOURS. CLOUDS WILL GRADUALLY SCT
OUT FROM NE TO SW...WITH AREAS ALONG AND S OF I64 CORRIDOR THE
LAST TO LOSE THE STRATUS...POSSIBLY HOLDING ON UNTIL LATE
AFTERNOON.
FOR TEMPS...USED A BLEND OF LAMP AND HRRR FOR TEMPS TONIGHT. FOR
SUNDAY...USED MET AS A BASE WHICH BETTER REFLECTED EXPECTED COOLER
READINGS ALONG AND ESPECIALLY S OF I64 CORRIDOR DUE TO CLOUDS.
FURTHER N...FELT LOCAL MOS WAS THE WAY TO GO WHERE READINGS SHOULD
REACH INTO THE MID OR UPPER 40S.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
STILL A TOUGH CLOUD AND TEMPERATURE FORECAST FOR SUNDAY...WITH LOW
LEVEL MOISTURE MOSTLY AOB 925 MB SUNDAY MORNING. WILL HOLD ONTO
THOSE CLOUDS A BIT LONGER IN SOUTHERN COAL FIELDS OF WV.
SURFACE HIGH PRESSURE QUICKLY PASSES OUR LONGITUDE SUNDAY AFTERNOON
WITH LOW LEVEL FLOW VEERING TO EAST AND SOUTHEAST SUNDAY NIGHT.
ANOTHER TOUGH TEMPERATURE FORECAST WITH 925 MB FLOW BLOWING AT 15 TO
25 KNOTS. SOME HIGH CLOUDS MAY ALSO BE AROUND SUNDAY NIGHT. WILL
TRY TO DROP TEMPERATURES A BIT LOWER...BUT NOT AS LOW AS NAM AND GFS
MOS GUIDANCE.
THE SURFACE WAVE ALONG THE MID ATLANTIC COAST...TRYING TO GET
ORGANIZED MONDAY INTO MONDAY NIGHT...MAY BRUSH OUR EASTERN MOUNTAIN
COUNTIES WITH DEEPER MOISTURE...BUT CURRENTLY WILL ONLY HAVE CHANCE
POPS THERE....BEFORE THAT DEEPER MOISTURE GETS SHUNTED EAST. THE
EASTERN LOW LEVEL FLOW SHOULD KEEP THOSE UPSLOPE AREAS A BIT COOLER
FOR MONDAY MAXIMUM TEMPERATURE. THE WESTERN
THE DIGGING UPPER/MID LEVEL TROUGH FROM THE UPPER MIDWEST STARTS
AFFECTING US TUESDAY WITH COLDER AIR BECOMING ESTABLISHED BY TUESDAY
NIGHT. INCREASED POPS FOR SNOW SHOWERS...ESPECIALLY FOR TUESDAY
NIGHT.
OVERALL...NO MAJOR STORMS FORESEEN...BUT A COLDER PATTERN
BY TUESDAY INTO WEDNESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
USED A BLEND OF THE GFS...GEFS MEAN...ECMWF...ECMWF MEAN...AND
CONTINUITY WITH THE PREVIOUS FORECAST. THIS WOULD HAVE WRAP AROUND
MOISTURE OVER THE REGION FOR TUESDAY NIGHT INTO WEDNESDAY. 850 MB
TEMPERATURES ARE MARGINAL FOR UPSLOPE SNOW...SO COULD SEE DRIZZLE
INSTEAD OF SNOW IN MANY AREAS. A HIGH PRESSURE SYSTEM THEN MOVES IN
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...ALLOWING
TEMPERATURES TO MODERATE SOME.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SURFACE FRONT WAS E OF CRW/CKB AS OF 18Z. EXPECT IT TO CROSS KEKN
AND KBKW BY 20Z. CIGS AND VSBY WILL LOWER INTO IFR OR WORSE FOR A
TIME IN POST FRONTAL DZ ACROSS MUCH OF THE AREA. WINDS WILL ALSO
GUST IN THE 15 TO 20 KT RANGE...A BIT HIGHER WITH ACTUAL FROPA.
ANOTHER ROUND OF SHRA POSSIBLE LATER THIS AFTERNOON AND INTO THE
EARLY EVENING HRS WITH THE PASSAGE OF THE UPPER LEVEL TROF.
ALLOWED TO VSBY TO IMPROVE INTO MVFR AND EVENTUAL VFR OVERNIGHT AS
DRIER AIR ADVECTS IN NEAR THE SURFACE. ALSO ALLOWED CIGS TO LIFT A
BIT INTO MVFR...FOLLOWING PASSAGE OF THE UPPER TROF. STILL HAVE
CIGS BELOW 2 GRAND MARK THOUGH.
THE LOW STRATUS SHOULD SCT OUT ACROSS SE OH OVERNIGHT...BUT WILL
HANG TOUGH E OF THE OH RIVER TO AFFECT THE TAF SITES. THE LOW
LEVEL FLOW WILL BECOME MORE NE OVERNIGHT WITH SOME GUSTS
CONTINUING. THIS COMBINED WITH DEVELOPING SUBSIDENCE INVERSION
WILL KEEP THE LOW STRATUS IN PLACE FIRST HALF OF SUNDAY...WITH
KCRW AND KHTS PERHAPS NOT SCT OUT UNTIL AFTER END OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS MAY VARY.
TIMING ERADICATION OF LOW STRATUS MAY VARY...POSSIBLY OCCURRING
MUCH SOONER THAN CURRENTLY FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M M H H H H H H H H H H
BKW CONSISTENCY H H H H H M M L L L L H
EKN CONSISTENCY H H H L L L L L L L L L
PKB CONSISTENCY H M H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
IFR POSSIBLE IN RAIN/SNOW MONDAY NIGHT INTO WEDNESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30/26
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...RPY
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
147 PM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WAVE PASSES WITH COLDER AIR IN ITS WAKE TONIGHT.
HIGH PRESSURE SUNDAY. LOW PRESSURE ALONG MID ATLANTIC COAST MONDAY
NIGHT. COLD FRONT TUESDAY WITH COLDER AIR TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 18Z THE FRONT HAS CLEARED CRW AND CKB WITH SURFACE LOW E OF
EKN. FRONT WILL CLEAR THE MOUNTAINS BY 21Z. AS THE FRONT
CROSSES...TEMPERATURE FALLS OF 7 TO 10 DEGREES CAN BE EXPECTED
WITH GRADUALLY LOWERING TEMPS THEREAFTER THROUGH THE EVENING. LOW
CIGS AND VSBY IN POST FRONTAL DZ CAN BE EXPECTED THRU THE
REMAINDER OF THE AFTERNOON...ALONG WITH GUSTY NW WINDS. WILL WATCH
-RA TO FILL BACK IN LATER THIS AFTERNOON AS THE UPPER LEVEL TROF
CROSSES. AREA WILL BEGIN TO DRY OUT WITH PASSAGE OF THE UPPER
LEVEL TROF...SAVE FOR SOME DZ HANGING ON ACROSS THE MOUNTAINS THIS
EVENING. ELECTED TO KEEP POSSIBILITY OF IT ENDING AS A LITTLE FRZ
DZ BUT NOT EXPECTING ANY IMPACTS.
WHAT WILL NOT CLEAR OUT THIS EVENING IS THE LOW STRATUS.
HOWEVER...DO EXPECT BASES TO LIFT A BIT TONIGHT. THINK SE OH WILL
SCT OUT DURING THE PREDAWN. HOWEVER...DEVELOPING SUBSIDENCE
INVERSION BENEATH THIS LINGERING MOISTURE WILL MAKE IT VERY
DIFFICULT FOR STRATUS TO BREAK UP E OF THE OH RIVER OVERNIGHT. WITH WEAK
CAA BENEATH THE INVERSION AND LOW LEVEL WINDS BECOMING MORE
NE...FELT IT NECESSARY TO HOLD THE STRATUS IN ALONG THE
CLIMATOLOGICAL FAVORED AREAS IN THIS SETUP....IE THE C LOWLANDS
AND COAL FIELDS THRU THE MORNING HOURS. CLOUDS WILL GRADUALLY SCT
OUT FROM NE TO SW...WITH AREAS ALONG AND S OF I64 CORRIDOR THE
LAST TO LOSE THE STRATUS...POSSIBLY HOLDING ON UNTIL LATE
AFTERNOON.
FOR TEMPS...USED A BLEND OF LAMP AND HRRR FOR TEMPS TONIGHT. FOR
SUNDAY...USED MET AS A BASE WHICH BETTER REFLECTED EXPECTED COOLER
READINGS ALONG AND ESPECIALLY S OF I64 CORRIDOR DUE TO CLOUDS.
FURTHER N...FELT LOCAL MOS WAS THE WAY TO GO WHERE READINGS SHOULD
REACH INTO THE MID OR UPPER 40S.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
STILL A TOUGH CLOUD AND TEMPERATURE FORECAST FOR SUNDAY...WITH LOW
LEVEL MOISTURE MOSTLY AOB 925 MB SUNDAY MORNING. WILL HOLD ONTO
THOSE CLOUDS A BIT LONGER IN SOUTHERN COAL FIELDS OF WV.
SURFACE HIGH PRESSURE QUICKLY PASSES OUR LONGITUDE SUNDAY AFTERNOON
WITH LOW LEVEL FLOW VEERING TO EAST AND SOUTHEAST SUNDAY NIGHT.
ANOTHER TOUGH TEMPERATURE FORECAST WITH 925 MB FLOW BLOWING AT 15 TO
25 KNOTS. SOME HIGH CLOUDS MAY ALSO BE AROUND SUNDAY NIGHT. WILL
TRY TO DROP TEMPERATURES A BIT LOWER...BUT NOT AS LOW AS NAM AND GFS
MOS GUIDANCE.
THE SURFACE WAVE ALONG THE MID ATLANTIC COAST...TRYING TO GET
ORGANIZED MONDAY INTO MONDAY NIGHT...MAY BRUSH OUR EASTERN MOUNTAIN
COUNTIES WITH DEEPER MOISTURE...BUT CURRENTLY WILL ONLY HAVE CHANCE
POPS THERE....BEFORE THAT DEEPER MOISTURE GETS SHUNTED EAST. THE
EASTERN LOW LEVEL FLOW SHOULD KEEP THOSE UPSLOPE AREAS A BIT COOLER
FOR MONDAY MAXIMUM TEMPERATURE. THE WESTERN
THE DIGGING UPPER/MID LEVEL TROUGH FROM THE UPPER MIDWEST STARTS
AFFECTING US TUESDAY WITH COLDER AIR BECOMING ESTABLISHED BY TUESDAY
NIGHT. INCREASED POPS FOR SNOW SHOWERS...ESPECIALLY FOR TUESDAY
NIGHT.
OVERALL...NO MAJOR STORMS FORESEEN...BUT A COLDER PATTERN
BY TUESDAY INTO WEDNESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MODELS INDICATE A HIGH PRESSURE MOVING OVER NEW ENGLAND...EXTENDING
SOUTHWEST INTO WV SUNDAY NIGHT. ALTHOUGH A COLD AIR MASS WILL BE IN
PLACE...THIS PATTERN WOULD BRING EAST TO SOUTHEAST FLOW...CAPABLE TO
PRODUCE DOWNSLOPING WARMING ACROSS THE LOWLANDS SUNDAY NIGHT.
INCREASED FEW DEGREES FROM HPC GUIDANCE ACCORDINGLY.
FOR MONDAY...BUFKIT SOUNDINGS SHOW DRY AIR ALOFT WITH LIMITED
MOISTURE IN THE VERY LOW LEVELS WHILE A H500 WEAK SHORTWAVE CROSSES
THE AREA. KEPT LOW CHANCE POPS WITH THIS FEATURE...MORE ALONG THE
GFS SOLUTION. THE ECMWF BRINGS STRONG COLD AIR ADVECTION FOR THE
SAME TIME PERIOD WITH SUCH A WEAK WAVE. BELIEVE ECMWF IS OVERDOING
CAA SO PREFERRED THE GFS.
BY MONDAY NIGHT FLOW IN THE LOW LEVELS TURN NORTHWEST WITH SOME CAA
FROM BOTH MODELS. FIGURE A GOOD SET UP FOR UPSLOPE PCPN. THE GFS
BRINGS THE 0C LEVEL AROUND THE NORTHEAST MOUNTAINS WHILE IN THE
ECMWF...THE 0C LINE GOES WAY SOUTH OF THE AREA. WENT WITH A BLEND
SOLUTION EXPECTING CHANCE POPS WITH FEW SNOW SHOWERS OR MIX PCPN
OVER THE MOST FAVORABLE UPSLOPE AREAS...AND RAIN ELSEWHERE. PCPN IS
EXPECTED TO TAMPER OFF ON TUESDAY KEEPING CHANCE POPS OVER THE
EASTERN MOUNTAINS ESPECIALLY WITH THE UPSLOPE COMPONENT AND DRY
WEATHER SPREADING FROM SOUTHEAST OH...EAST.
DRY WEATHER EXPECTED THROUGH THE REST OF THE PERIOD AS A HIGH
PRESSURE BUILDS IN.
WENT CLOSE TO HPC TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SURFACE FRONT WAS E OF CRW/CKB AS OF 18Z. EXPECT IT TO CROSS KEKN
AND KBKW BY 20Z. CIGS AND VSBY WILL LOWER INTO IFR OR WORSE FOR A
TIME IN POST FRONTAL DZ ACROSS MUCH OF THE AREA. WINDS WILL ALSO
GUST IN THE 15 TO 20 KT RANGE...A BIT HIGHER WITH ACTUAL FROPA.
ANOTHER ROUND OF SHRA POSSIBLE LATER THIS AFTERNOON AND INTO THE
EARLY EVENING HRS WITH THE PASSAGE OF THE UPPER LEVEL TROF.
ALLOWED TO VSBY TO IMPROVE INTO MVFR AND EVENTUAL VFR OVERNIGHT AS
DRIER AIR ADVECTS IN NEAR THE SURFACE. ALSO ALLOWED CIGS TO LIFT A
BIT INTO MVFR...FOLLOWING PASSAGE OF THE UPPER TROF. STILL HAVE
CIGS BELOW 2 GRAND MARK THOUGH.
THE LOW STRATUS SHOULD SCT OUT ACROSS SE OH OVERNIGHT...BUT WILL
HANG TOUGH E OF THE OH RIVER TO AFFECT THE TAF SITES. THE LOW
LEVEL FLOW WILL BECOME MORE NE OVERNIGHT WITH SOME GUSTS
CONTINUING. THIS COMBINED WITH DEVELOPING SUBSIDENCE INVERSION
WILL KEEP THE LOW STRATUS IN PLACE FIRST HALF OF SUNDAY...WITH
KCRW AND KHTS PERHAPS NOT SCT OUT UNTIL AFTER END OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS MAY VARY.
TIMING ERADICATION OF LOW STRATUS MAY VARY...POSSIBLY OCCURRING
MUCH SOONER THAN CURRENTLY FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M M H H H H H H H H H H
BKW CONSISTENCY H H H H H M M L L L L H
EKN CONSISTENCY H H H L L L L L L L L L
PKB CONSISTENCY H M H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
IFR POSSIBLE IN RAIN/SNOW MONDAY NIGHT INTO TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30/26
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
304 PM CST SAT DEC 6 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM CST SAT DEC 6 2014
COMPLEX FORECAST OVER THE NEXT DAY AS AN UPPER WAVE MOVES ACROSS THE
AREA...ACCOMPANIED BY A LOW PRESSURE MOVING ACROSS THE CANADIAN
BORDER DRAGGING A COLD FRONT THROUGH THE REGION. AS OF THIS
AFTERNOON...LOW STRATUS HAS ERODED AND PUSHED OFF TO THE SOUTH OF
THE CWA. HOWEVER AS LOW LEVEL WINDS TURN MORE SOUTHEASTERLY AND
SOUTHERLY AHEAD OF THE APPROACHING FRONT...EXPECT THIS STRATUS TO
BEGIN STREAMING BACK INTO THE REGION. THE RAP SEEMS TO HAVE THE BEST
HANDLE ON THIS...AND THINK THIS LOW STRATUS SHOULD APPROACH SIOUX
CITY AROUND MIDNIGHT...PUSHING NORTH INTO THE EARLY MORNING
HOURS...LIKELY MAKING IT EVERYWHERE ALONG AND EAST OF THE JAMES
RIVER.
NEXT QUESTION IS FOG POTENTIAL. ONE THING GOING AGAINST WIDESPREAD
DENSE FOG IS THE STRONG SOUTHERLY BREEZE...WHICH WILL LIKELY BE
AVERAGING 15 TO 25 MPH...GUSTING 25 TO 35 MPH. PROBABLY EVEN A BIT
HIGHER ALONG THE BUFFALO RIDGE. HOWEVER MOISTURE IS SHALLOW AND NEAR
THE GROUND...SO STRATUS COULD COME IN LOW ENOUGH TO RESULT IN DENSE
FOG EVEN GIVEN THE WIND...WHICH THE RAP SUGGESTS. GIVEN THE
UNCERTAINTY WILL JUST INCLUDE PATCHY FOG IN THE GRIDS FOR NOW...AND
THE EVENING AND OVERNIGHT SHIFT WILL HAVE TO MONITOR TRENDS AND
ADJUST AS NEEDED.
THE NEXT QUESTION IS PRECIPITATION POTENTIAL. TWO ASPECTS TO
THIS...DRIZZLE WITH THE LOW LEVEL MOISTURE...AND RAIN WITH THE UPPER
LEVEL FEATURE AND FRONTOGENESIS. WITH REGARDS TO THE DRIZZLE
POTENTIAL...MOISTURE IS ORIGINALLY PRETTY SHALLOW WHICH WOULD SEEM
TO MAKE DRIZZLE UNLIKELY. BY LATER TONIGHT INTO TOMORROW MORNING
MOISTURE DEPTH BEGINS TO INCREASE...AS DOES LIFT IN THE MOISTURE
LAYER. THIS WOULD SEEM TO SUGGEST AN INCREASE IN THE DRIZZLE
POTENTIAL BY MID MORNING EAST OF THE JAMES RIVER. THE PASSAGE OF THE
FRONT WILL EVENTUALLY END THAT THREAT FROM WEST TO EAST THROUGH THE
AFTERNOON. THE UPPER LEVEL WAVE AND MID LEVEL FRONTOGENESIS WILL TRY
TO PRODUCE SOME LIGHT PRECIPITATION AS WELL FROM EARLY SUNDAY INTO
THE AFTERNOON. QUITE A BIT OF MID LEVEL DRY AIR FOR THIS
PRECIPITATION TO OVERCOME THOUGH...AND MOST MODELS ARE TRENDING
DRIER. SO DID CUT BACK QPF...WITH BEST CHANCE OF MEASURABLE
PRECIPITATION ALONG AND EAST OF INTERSTATE 29...WITH CHANCES
INCREASING AS YOU GO EAST.
LAST QUESTION IS PRECIPITATION TYPE. WITH QUITE A STRONG WARM NOSE
ALOFT...THINK ANYTHING WILL EITHER BE LIGHT RAIN OR FREEZING RAIN.
COULD SEE A BIT OF SLEET MIXED IN...BUT NOT EXPECTING IT TO BE A
PREDOMINANT TYPE. THUS PTYPE WILL PROBABLY COME DOWN TO SURFACE
TEMPERATURES. USED A BLEND OF RAW GUIDANCE...WEIGHTED TOWARDS THE
GEM...ECMWF AND WRF ARW FOR HOURLY TEMPERATURES TONIGHT INTO
TOMORROW. THIS WARMS SIOUX CITY ABOVE FREEZING BY 14Z...SIOUX FALLS
BY 16Z AND THE REMAINDER OF THE CWA BY 18Z. THUS I DO THINK A PERIOD
OF FREEZING DRIZZLE OR LIGHT FREEZING RAIN IS POSSIBLE. ALTHOUGH BY
THE TIME THE DRIZZLE INCREASES...WE COULD VERY WELL BE ABOVE
FREEZING...LIMITING THE FREEZING POTENTIAL. THE BEST CHANCE OF A
LIGHT COATING OF ICE SEEMS TO BE EAST OF INTERSTATE 29 WHERE COLD
AIR HOLDS ON A BIT LONGER. GIVEN THE UNCERTAINTY WILL HOLD OFF ON
ANY ADVISORY. BUT THOSE WITH MORNING TRAVEL PLANS SHOULD KEEP ALERT
OF THE FORECAST...AS EVEN JUST A LIGHT COATING OF ICE CAN CAUSE
IMPACTS. EVENING AND OVERNIGHT SHIFT WILL HAVE TO MONITOR
TRENDS...AND ISSUE ANY ADVISORY IF CONFIDENCE IN MORE WIDESPREAD
FREEZING DRIZZLE OR LIGHT FREEZING RAIN INCREASES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM CST SAT DEC 6 2014
THE MAIN FOCUS IN THE MEDIUM AND EXTENDED FOCUSES ON TEMPERATURES.
WHILE MAJORITY OF PRECIPITATION WILL TAKE PLACE DURING THE DAY ON
SUNDAY...WILL HAVE TO WATCH FOR LOW STRATUS ROTATING BACK INTO THE
AREA BEHIND DEPARTING UPPER TROUGH SUNDAY NIGHT. SOUNDINGS SUGGEST
A VERY LIGHT PRECIPITATION POTENTIAL...IN THE FORM OF
FLURRIES/SPRINKLES/DRIZZLE.
COLDER AIR WILL NOT QUITE MAKE IT SOUTHWARD ON MONDAY...BUT THE
WESTERLY WIND AND LINGERING WARM AIR ALOFT WILL STILL ALLOW FOR
ABOVE NORMAL TEMPERATURES. A MORE DIRECT COOLDOWN WILL ARRIVE ON
TUESDAY AS SURFACE HIGH PRESSURE MOVES OVERHEAD. THE MISSOURI RIVER
VALLEY MAY STILL REACH THE MID 30S...BUT AREAS FURTHER NORTHEAST
COULD STRUGGLE TO CLIMB ABOVE FREEZING.
LOW LVL WARM ADVECTION BEGINS LATE TUESDAY AS MID-LVL HEIGHTS RISE
OVER THE CENTRAL CONUS. GFS/ECMWF CONSISTENT NOW IN BRINGING A
WEAK SHORTWAVE THROUGH THE AREA TUESDAY NIGHT AND WEDNESDAY...BUT
LITTLE IMPACT IS ANTICIPATED OTHER THAN CLOUD COVER.
THEN BEGINS A STRETCH OF ABOVE NORMAL TEMPERATURES...SOME THAT COULD
RIVAL SOME OF OUR WARMER TEMPERATURES RECORDED IN DECEMBER.
MODELS STILL DIFFERING TO SOME DEGREE ON MOISTURE RETURN AND
IMPACT ON STRATUS ACROSS THE REGION. ALOFT...TEMPERATURES ARE
SURELY IMPRESSIVE WITH 925MB TEMPERATURES BY SATURDAY APPROACHING
+10C...AND 850MB TEMPERATURES AROUND +15C...SOME OF THE WARMEST
READINGS RECORDED VIA SOUNDINGS IN DECEMBER AT ABERDEEN. MODEL
PREFERENCE CONTINUES TO FALL WITH THE ECMWF...WHICH DOES SHOW
STRATUS ADVECTING INTO THE AREA BY THURSDAY...BUT IS NOT NEARLY AS
AGGRESSIVE AS THE TYPICALLY OVERSATURATED GFS AND SUGGESTED A
SLIGHTLY MORE VEERED LOW LVL FLOW. THAT SAID...FOR TEMPERATURES
WED- SAT UTILIZED A BLEND OF WPC AND ECMWF...WHICH FALL ON THE
WARMEST SIDE OF GUIDANCE AND STILL MAY NOT BE WARM ENOUGH FOR
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1132 AM CST SAT DEC 6 2014
COMPLEX FORECAST OVER THE NEXT 24 HOURS. STRATUS NEAR KSUX
CONTINUES TO DISSIPATE AND MOVE OFF TO THE SOUTHWEST...AND EXPECT
THEM TO BE VFR BY 19 OR 20Z. HOWEVER...AS THE SOUTHERLY LOW LEVEL
JET INCREASES TONIGHT...EXPECT THIS STRATUS TO RETURN TO THE
AREA. TIMED THIS USING A MODEL CONSENSUS...WEIGHTED TOWARDS THE
RAP WHICH CURRENTLY HAS THE BEST HANDLE OF THINGS. UNCERTAINTY ON
HOW LOW THE CIGS GET...SO KEPT IFR FOR NOW...BUT WOULD NOT BE
SURPRISED TO SEE AREAS OF LIFR. ALSO THE SOUTHERLY BREEZE MAY KEEP
DENSE FOG FROM FORMING...ALTHOUGH STRATUS MAY COME IN LOW ENOUGH
THAT WE DO INDEED GET DENSE FOG. SO IN SUMMARY...CONFIDENCE ON AT
LEAST MVFR TO IFR CIGS IS HIGH TONIGHT INTO TOMORROW
MORNING...CONFIDENCE ON TIMING IS MODERATE...WITH LOW CONFIDENCE
ON EXACT CIG HEIGHT AND VISIBILITY.
OTHER CONCERN IS DRIZZLE OR FREEZING FRIZZLE. THIS IS CERTAINLY A
POSSIBILITY WITH THE STRATUS...ALTHOUGH WOULD LIKE TO SEE A
DEEPER LAYER OF SATURATION. THUS CONFIDENCE REMAINS LOW ON THIS
AND WILL KEEP OUT OF THE TAFS FOR NOW. ALSO MAY SEE A PERIOD OF
LIGHT RAIN OR FREEZING RAIN AS THE FRONT AND WAVE PASS ACROSS
TOMORROW MORNING. BUT BEST CHANCE OF THIS IS EAST OF INTERSTATE
29...SO WILL KEEP THE TAFS DRY. BUT WITH THE LIGHT FREEZING RAIN
OR DRIZZLE POTENTIAL...WILL NEED TO MONITOR TRENDS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...DUX
AVIATION...CHENARD