Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/04/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
ISSUED BY NATIONAL WEATHER SERVICE TUCSON AZ
931 AM MST TUE DEC 2 2014
.SYNOPSIS...
A LARGE AREA OF LOW PRESSURE AND DEEP TROPICAL MOISTURE PLUME WILL
AFFECT THE DESERT SOUTHWEST TODAY INTO THURSDAY...BRINGING SLIGHTLY
COOLER TEMPERATURES...CLOUDINESS...AND CHANCES OF OFF AND ON LIGHT
SHOWERS. UNSETTLED WEATHER MAY RETURN OVER THE WEEKEND AS ANOTHER
WEATHER SYSTEM AFFECTS THE WESTERN STATES.
&&
.DISCUSSION...LATEST IR/VIS SATELLITE IMAGERY SHOWS OVERCAST SKIES
ACROSS SOUTH CENTRAL ARIZONA INTO SOUTHEAST CALIFORNIA AS A DEEP
TROPICAL PLUME OF MOISTURE IS MAKING ITS WAY INTO THE AREA ON THE
SOUTHEAST SIDE OF AN UPPER LOW NOW NEAR 35N/135W. A CLEARLY DEFINED
TOP DOWN MOISTENING PROCESS IS UNDERWAY WITH THE 12Z YUMA SOUNDING
SHOWING A NEARLY SATURATED ATMOSPHERE ABOVE 600 MB AND ABOUT 0.7
INCHES OF PRECIPITABLE WATER. CURRENT SURFACE DEWPOINTS ARE NOW IN
THE 40S FROM THE LOWER COLORADO RIVER VALLEY INTO SOUTHEAST
CALIFORNIA AND MAINLY IN THE 30S ACROSS SOUTH CENTRAL ARIZONA. RADAR
IMAGERY IS STILL FAIRLY QUIET IN OUR CWA WITH JUST A FEW POCKETS OF
VIRGA...BUT EXPECT ISOLATED TO PERHAPS SCATTERED SHOWERS TO PICKUP
THIS AFTERNOON ESPECIALLY ACROSS SOUTHEAST CALIFORNIA AS FAVORABLE
SOUTHWEST FLOW WILL CONTINUE TO TRANSPORT ABUNDANT MOISTURE INTO THE
AREA. THIS MOISTURE WILL COMBINE WITH EMBEDDED DISTURBANCES ALOFT
PROVIDING INCREASED LIFT TO PRODUCE SOME SHOWERS. AS THE EVENING
PROGRESSES AND INTO THE OVERNIGHT HOURS...THE CHANCE OF SHOWERS WILL
PROGRESS EASTWARD INTO SOUTH CENTRAL ARIZONA INCLUDING THE PHOENIX
AREA. NOTE THAT THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH THE
SHORT TERM GUIDANCE WITH THIS SYSTEM AS THE HRRR AND RUC13 ARE MORE
AGGRESSIVE BRINGING SHOWERS EASTWARD INTO THE PHOENIX AREA TONIGHT
COMPARED TO THE RELATIVELY DRY NAM12 FOR EXAMPLE. CURRENT THINKING
IS THE NAM12 IS TOO DRY AND LEANING TOWARDS THE WETTER SOLUTIONS.
BELIEVE OUR CURRENT FORECAST HANDLES THIS WELL AND LOOKS IN GOOD
SHAPE...SO NO UPDATES NEEDED DAT THIS TIME. SEE PREVIOUS DISCUSSION
BELOW FOR ADDITIONAL DETAILS.
&&
.PREVIOUS DISCUSSION...
SOLID BAND OF TROPICAL MOISTURE STRETCHED FROM THE EAST CENTRAL
PACIFIC WELL INTO CA...AZ AND UT THIS MORNING PER IR/WV IMAGERY. MID
TO HIGH LEVEL CLOUDS DECKS FROM 8KFT TO 20KFT HAVE BEEN OBSERVED SO
FAR OVER SOME OF THE SOUTHERN CA AIRFIELDS WITH SOME OF THE THICKER
CLOUDS AND LIGHT SHOWER ACTIVITY PICKED UP ON AREA RADARS. LARGE
AREA OF WEAKENING PACIFIC LOW PRESSURE WILL HELP TO DRAW THIS
MOISTURE FURTHER INTO CA TODAY. CLOUD COVER FOR MUCH OF THE EVENING
ALONG WITH GRADUALLY INCREASING DEWPOINTS HAVE KEPT OVERNIGHT TEMPS
MILD ACROSS OUR FORECAST AREA. WHILE AM TEMPERATURES ARE STARTING
OFF WARMER...IN SOME LOCALES BY 6 TO 8 DEGREES...THICK CLOUD COVER
TODAY SHOULD LIMIT THE TOP END OF THE DIURNAL CURVE. INCREASING
LIGHT SHOWER COVERAGE ACROSS THE WESTERN FORECAST ZONES WILL ALLOW
FOR UPPER 60 TO LOW 70 DEGREE READINGS AND THICK CLOUD COVER WILL
ALSO LIMIT THE DIURNAL CURVE ACROSS SOUTH-CENTRAL AZ WITH LOW 70S
POSSIBLE FOR PHX AND SURROUNDING LOWER DESERTS.
WHILE THE OVERALL SYNOPTIC PATTERN REMAINS LARGELY THE SAME AS
PREVIOUS FORECASTS...SOME INCREASED SHORT TERM MODEL AGREEMENT
WARRANTED SIGNIFICANT CHANGES TO THE FORECAST. SYNOPTICALLY
SPEAKING...WILL WATCH THE UPPER LOW WEAKEN OFF THE NORTHERN CA COAST
WHILE THE BULK OF THE MOISTURE PLUME WILL BE EXHAUSTED OVER THE
COASTAL MOUNTAINS OF SOUTHERN CA. ELEVATED MID TO HIGH LEVEL
MOISTURE...NEARLY SATURATING FORECAST SOUNDINGS OVER THE WESTERN
FORECAST ZONES...WILL EXPAND INTO SOUTHEAST CA TODAY. STILL
EXPECTING THE BEST WINDOW FOR PRECIP ACTIVITY TO BEGIN TODAY AND
LAST THROUGH THURSDAY AREAWIDE AND COULD EVEN BROKEN DOWN FURTHER BY
WHAT COULD BE LOOKED AT AS THREE POTENTIAL WAVES/ROUNDS OF PRECIP
ACTIVITY.
THE FIRST COMES WITH THE INITIAL EXPANSION OF THE ELEVATED MOISTURE
PLUME FURTHER INTO THE AREA TODAY. WITH FAVORABLE OROGRAPHIC
ORIENTATION AND SUBTLE 300MB JET SUPPORT (75-80KTS) NOSING OVER THE
SANTA ROSA...SAN JACINTO AND SAN BERNARDINO MTNS. LIGHT SHOWER
ACTIVITY...HEAVIER EXPECTED ACROSS SOME OF THE HIGHEST
ELEVATIONS...WILL PICK UP THROUGH THE DAY ACROSS THE SOUTHEAST CA
FORECAST ZONES. WITH THE BEST DYNAMICS IN TERMS OF LAPSE RATES AND
LIFT REMAIN WELL TO OUR NORTHWEST COVERAGE OF PRECIP WILL BE
SPOTTY...CERTAINLY SO THE LOWER IN ELEVATION YOU GO INTO THE DESERTS
AND TOWARDS THE CO RIVER VALLEY. THE FIRST WAVE WILL RESULT
GENERALLY IN A BRUSHPASS FOR THE SOUTH-CENTRAL AZ DESERTS INTO THE
EVENING...WITH VIRGA AND THICKENING CLOUDS THE MAJORITY RESULT.
CLOUDY CONDITIONS WILL CONTINUE INTO WEDNESDAY. EVEN WITH SLIGHT
CHANCE TO CHANCE POPS IN THE FORECAST...TRACE TO VERY LIGHT RAINFALL
AMOUNTS ARE POSSIBLE FOR THE LOWER DESERT LOCALES. DELIBERATELY WENT
WITH COVERAGE WORDING IN THE WEATHER GRIDS TODAY...DESCRIPTORS LIKE
ISOLATED TO SCATTERED FITTING THIS ROUND OF POTENTIAL PRECIP.
THE PACIFIC LOW WILL EVENTUALLY OPEN UP INTO A WAVE AS THE
CIRCULATION CENTER LIFTS INTO THE PACIFIC NW LATE WEDNESDAY INTO
THURSDAY. TRAILING SHORTWAVE ENERGY OFF THE MAIN LOW WILL SYNC WITH
A VORT MAX CURRENTLY MOVING THROUGH THE TROPICAL MOISTURE TAP WELL
WEST OF SOUTHERN BAJA OVER THE PACIFIC. IR/WV IMAGERY SHOW THIS
FEATURE SUPPORTING SOME COOLER...POSSIBLE CONVECTIVE...CLOUD TOPS AS
IT WAS MOVING TO THE E-NE. THESE ELEMENTS COMBINED WITH A IMPROVING
MOISTURE PROFILE OVER AZ...WITH POTENTIAL PWATS OVER AN INCH IN SOME
LOCALES...INTRODUCE THE SECOND POTENTIAL WAVE OF PRECIP ACTIVITY
POSSIBLE BY EARLY THURSDAY MORNING. GFS/EC FORECASTS ARE IN GENERAL
AGREEMENT THAT THIS ROUND COULD HAVE THE HEAVIEST RAINFALL AMOUNTS
IN THE PERIOD WITH WIDESPREAD SHOWER ACTIVITY POSSIBLE BY THE
THURSDAY AM COMMUTE. ANY LINGERING DYNAMICS AND MOISTURE CLEAR TO
THE EAST THROUGH THE DAY THURSDAY...DRYING CONDITIONS OUT FOR FRIDAY
WHILE KEEPING DAYTIME TEMPERATURES FAIRLY MILD.
BEYOND FRIDAY...MODEL CONFIDENCE HAS TAKEN ANOTHER NOTICEABLE DIVE.
WHAT COULD STILL BE THE POTENTIAL THIRD WAVE OF PRECIP IN THE FORM
OF A FAST MOVING PACIFIC SHORTWAVE HAS WIDELY VARYING FORECAST AND
PRECIP SOLNS IN THE GFS/ECMWF/GEM SUITES. FORECAST SOLNS AND TIMING
PHASE FURTHER HEADING INTO NEXT WEEK. AS SUCH...TEMPERATURE AND POP
FORECASTS WERE BLENDED OF CONSENSUS AND CLIMO GUIDANCE. WE WILL
STILL HOLD ON TO SLIGHTLY ABOVE NORMAL HIGH TEMPERATURES...ONLY
SLIGHT CHANCES SATURDAY ACROSS THE HIGHER TERRAIN OF SOUTHERN GILA
COUNTY AND MOSTLY DRY CONDITIONS TO OPEN NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
CIGS WILL THICKEN AND LOWER THROUGH WEDNESDAY MORNING...WITH MODELS
IN GOOD AGREEMENT BASE HEIGHTS FALLING TO AROUND 7K FT THIS EVENING
AND OVERNIGHT. BEST OPPORTUNITY FOR CIGS FALLING TO THE 6K FT
THRESHOLD WILL BE LATER WEDNESDAY MORNING INTO THURSDAY.
OTHERWISE...VIRGA WILL LIKELY BE EXTENSIVE TODAY AND TONIGHT WITH
ONLY A FEW ISOLD SHRA REACHING THE SFC AROUND CNTRL ARIZONA
TERMINALS. SFC WINDS WILL STAY VERY LIGHT...AND COULD REMAIN LIGHT
AND VARIABLE FOR EXTENDED TIME PERIODS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND
KBLH...
CIGS WILL THICKEN AND LOWER SUBSTANTIALLY THROUGH WEDNESDAY MORNING
WITH SCATTERED SHOWERS AFFECTING ALL OF SOUTHEAST CALIFORNIA.
CONFIDENCE IS HIGH THAT EXTENSIVE VIRGA AND EVENTUALLY SCT SHRA WILL
PREVAIL THROUGHOUT THE AREA...HOWEVER TIMING OF MORE EXPANSIVE SHRA
AND LOWEST CIG AGL ARE MORE UNCERTAIN. HAVE ONLY INCLUDED A VICINITY
MENTION FOR THE TIME BEING AS SHRA MAY BE MORE SHORT DURATION/LOWER
IMPACT...AND KEPT CIGS AOA 6F FT BASED ON FORECAST DATA.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A SERIES OF FAST MOVING WEATHER DISTURBANCES WILL BRING THE
OPPORTUNITY FOR SCATTERED SHOWERS TO THE DISTRICT. THURSDAY AND
SATURDAY WILL YIELD THE BEST CHANCES FOR WETTING RAIN...THOUGH
COVERAGE OF STORM TOTAL AMOUNTS OVER ONE TENTH OF AN INCH WILL BE
LIMITED. WITH WIDESPREAD EXCELLENT OVERNIGHT RECOVERY...AFTERNOON
MINIMUM HUMIDITY LEVELS WILL ONLY FALL INTO A 30-50 PERCENT RANGE
THROUGH THE WEEKEND...THEN TOWARDS A 20-30 PERCENT RANGE EARLY NEXT
WEEK. WIND SPEEDS WILL REMAIN VERY LIGHT AND THIS OVERALL TIME
FRAME WILL OFFER VERY LOW FIRE DANGER.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...GL
PREVIOUS DISCUSSION...NOLTE
AVIATION...MO
FIRE WEATHER...MO
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NWS LOS ANGELES/OXNARD CA
445 PM PST WED DEC 3 2014
...UPDATED PUBLIC DISCUSSION...
.SYNOPSIS...
SCATTERED SHOWERS WILL PERSIST ACROSS SOUTHWESTERN CALIFORNIA TODAY
WITH HEAVIER PRECIPITATION IN LOS ANGELES COUNTY LATE THIS AFTERNOON
AND EARLY EVENING. THERE IS A SLIGHT CHANCE OF LIGHT RAIN SHOWERS
FRIDAY NIGHT INTO EARLY SATURDAY...OTHERWISE CONDITIONS WILL BE DRY
AND WARMER INTO THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM (TODAY-SAT)...UPDATE
HAVE DECIDED TO ADD SLIGHT CHANCE OF THUNDERSTORMS TO THE EASTERN
PORTION OF LOS ANGELES COUNTY THROUGH MIDNIGHT. THIS WOULD ALSO
INCLUDE OVER THE RECENT BURN AREAS INCLUDING THE COLBY AND WILLIAMS
BURN AREAS. LATEST RAP MODELS WERE INDICATING MORE INSTABILITY OVER
EAST LOS ANGELES COUNTY INTO ORANGE COUNTY THROUGH MIDNIGHT. LATEST
RADAR RETURNS WERE ALSO INDICATING SOME STRONGER RAIN ENHANCEMENTS
OVER THIS REGION THIS WELL.
***FROM PREVIOUS DISCUSSION***
FORECAST AREA REMAINS DIVIDED INTO THREE SEPARATE PARTS. THE
NORTHERN AND SOUTHERN ENDS ARE WETTER WITH OCCASIONAL SHOWERS WHILE
THE MIDDLE THIRD (SBA AND SRN SLO COUNTIES) IS RELATIVELY DRY WITH
EVEN SOME SUNSHINE. THIS WILL REMAIN THE CASE THROUGH EARLY THU.
MOST OF THE PRECIP IS FAIRLY INNOCUOUS WITH RATES GENERALLY WELL
UNDER A TENTH OF AN INCH PER HR. THE MAIN AREA WE`RE FOCUSING IN ON
FOR TONIGHT IS LA COUNTY WHICH MODELS KEEP ON THE VERY NORTHERN
PERIPHERY OF SOME ENERGY COMING UP FROM THE SOUTHWEST LATER THIS
AFTERNOON AND TONIGHT. SINCE IT`S VERY DIFFICULT TO PICK OUT THIS
FEATURE ON SATELLITE IT`S NEXT TO IMPOSSIBLE TO EVALUATE WHETHER
MODELS ARE TRACKING THIS FEATURE CORRECTLY, AND EVEN A SLIGHT WAG
EITHER DIRECTION COULD BE THE DIFFERENCE BETWEEN SCATTERED LIGHT
SHOWERS AND RAIN RATES EQUAL TO OR IN EXCESS OF A HALF INCH PER
HOUR. WHILE MY GUT FEELING IS THAT THE HEAVIER ACTION WILL REMAIN TO
THE SOUTH AND EAST OF LA COUNTY, THERE REMAINS JUST ENOUGH OF A
CHANCE TO STAY THE COURSE ON THE FORECAST AND MAINTAIN THE BURN AREA
FLASH FLOOD WATCH AS IS. CERTAINLY RAINFALL COVERAGE AND INTENSITIES
WILL INCREASE SOMEWHAT THROUGH THE EVENING, BUT IN ORDER TO POSE A
THREAT TO BURN AREAS WE`LL NEED A CONSIDERABLE RAMP UP IN
INTENSITIES AND THE ODDS DON`T FAVOR THAT HAPPENING IN LA COUNTY.
AGAIN THOUGH, GIVEN THE RAMIFICATIONS OF THOSE POTENTIAL RAIN RATES
THERE REMAINS ENOUGH JUSTIFICATION FOR KEEPING THE WATCH GOING.
FAIRLY SAFE TO SAY THOUGH THAT IF THIS INTENSIFICATION DOES NOT
DEVELOP BY THIS EVENING THEN IT PROBABLY WON`T HAPPEN AND THE NEXT
SHIFT CAN CONTINUE TO EVALUATE THE NEED FOR THE WATCH GOING INTO THE
OVERNIGHT HOURS.
GOING INTO THU THE SOUTHERN PART OF THE FORECAST AREA IS EXPECTED TO
START DRYING OUT, HOWEVER THE NORTHERN THIRD, MOSTLY WRN SLO COUNTY
AND POSSIBLY THE NRN PORTION OF SBA, WILL CONTINUE TO SEE OCCASIONAL
LIGHT SHOWERS AS A WEAK WARM FRONTAL BOUNDARY SETS UP ALONG THE
CENTRAL COAST. AMOUNTS GENERALLY UNDER A TENTH OF AN INCH.
BY FRIDAY AFTERNOON AND EVENING MODELS ARE SHOWING ANOTHER WEAK
FRONTAL BOUNDARY HITTING THE CENTRAL COAST BRINGING ANOTHER INCREASE
IN RAIN CHANCES. THIS ONE APPEARS TO HAVE A LITTLE MORE STRENGTH TO
IT BUT STILL MOSTLY LIGHT AMOUNTS, QUARTER TO HALF INCH AT MOST. THE
FRONT WILL WEAKEN BUT LIKELY HOLD TOGETHER WELL ENOUGH TO GENERATE
SOME DRIZZLE/SPRINKLES/LIGHT SHOWERS AS FAR SOUTH AS LA COUNTY LATE
FRIDAY NIGHT.
IMPROVING CONDITIONS EXPECTED SATURDAY AS WE TRANSITION TO WEAK
NORTHERLY FLOW. THIS SHOULD CLEAR THINGS OUT PRETTY FAST BY
AFTERNOON WITH PLENTY OF SUNSHINE BY AFTERNOON AND WARMER TEMPS.
.LONG TERM (SUN-WED)...DRY AND WARMER THROUGH THE PERIOD AS HIGH
PRESSURE BUILDS ALOFT AND WEAK OFFSHORE FLOW DEVELOPS. HIGH TEMPS
WARMING INTO THE 70S BY MONDAY AND POSSIBLY SOME LOWER 80S BY EITHER
TUE OR WED.
&&
.AVIATION...04/0000Z...
AT 2315Z...THERE WAS NO MARINE INVERSION AT KLAX.
LOW TO MODERATE CONFIDENCE IN THE 00Z TAFS. ALTHO IFR/IFR/MVFR
CIGS/VSBYS ARE EXPECTED AT TIMES AT ALL AIRFIELDS DURING THE TAF
PERIOD...THE TIMING OF CIGS/VSBYS BETWEEN FLIGHT CATS IS PROBLEMATIC
WITH LOW CONFIDENCE. THERE IS MODERATE CONFIDENCE CONDITIONS WILL
IMPROVE TO VFR THU AFTERNOON AT KPRB...KOXR...AND MODERATE TO HI
CONFIDENCE AT KLAX...KLGB..KBUR AND KVNY. THERE IS ALSO MODERATE
CONFIDENCE THAT CIGS AT KSBP...KSMX AND KSBA WILL REMAIN MVFR THRU
THU AFTERNOON. AT KWJF AND KPMD...THERE IS GENERALLY HI CONFIDENCE
THAT CONDITIONS WILL IMPROVE TO VFR BY 15Z THU.
KLAX...LOW TO MODERATE CONFIDENCE IN THE 00Z TAF. ALTHO IFR/IFR/
MVFR CIGS/VSBYS ARE EXPECTED AT TIMES DURING THE TAF PERIOD...THE
TIMING OF CIGS/VSBYS BETWEEN FLIGHT CATS IS PROBLEMATIC WITH LOW
CONFIDENCE. THERE IS MODERATE TO HI CONFIDENCE THAT CONDITIONS WILL
IMPROVE TO VFR BY 20Z THU...BEFORE LOWERING TO MVFR BY 03Z THU
EVENING.
KBUR...LOW TO MODERATE CONFIDENCE IN THE 00Z TAF. ALTHO IFR/IFR/
MVFR CIGS/VSBYS ARE EXPECTED AT TIMES DURING THE TAF PERIOD...THE
TIMING OF CIGS/VSBYS BETWEEN FLIGHT CATS IS PROBLEMATIC WITH LOW
CONFIDENCE. THERE IS MODERATE TO HI CONFIDENCE THAT CONDITIONS WILL
IMPROVE TO VFR BY 14Z THU.
&&
.MARINE...03/0200 PM PST...
IT IS LIKELY SMALL CRAFT ADVISORY CONDITIONS WILL NOT EXIST THROUGH
THE PERIOD. OTHERWISE SWELLS ORIGINATING FROM THE LOW PRESSURE
SYSTEM OVER THE EASTERN PACIFIC WITHIN 240-270 DEGREES RELATIVE TO
SOUTHWEST CALIFORNIA WILL PEAK TODAY AND RANGE FROM 5-7 FEET IN THE
BIGHT AND 7-10 FEET ELSEWHERE. A LONGER PERIOD SWELL ORIGINATING
FROM THE WESTERN PACIFIC STORM LAST WEEK FRIDAY AND ORIENTED BETWEEN
290-300 DEGREES WILL ARRIVE THURSDAY MORNING AND PEAK THURSDAY NIGHT
AND REMAIN BELOW 8 FEET.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FOR LA COUNTY BURN AREAS (SEE LAXFFALOX).
BEACH HAZARDS STATEMENT (SEE LAXCFWLOX).
&&
$$
PUBLIC...KAPLAN/MW
AVIATION...SIRARD
MARINE...30
SYNOPSIS...KJ
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
322 PM MST TUE DEC 2 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 222 PM MST TUE DEC 2 2014
BIG RECOVERY TODAY WITH VERY MILD TEMPERATURES THAT WARMED EVEN
MORE THAN ANTICIPATED WITH A SOMEWHAT DELAYED ARRIVAL OF
CLOUDINESS FROM THE APPROACHING SYSTEM NOW HITTING THE WEST COAST.
WINDS HAVE BEEN INTERESTING WITH DIA STAYING RATHER QUIET WHILE
WESTERLIES PREVAILED ACROSS MUCH OF THE PLAINS...LOOKS LIKE A LEE
SIDE CYCLONE DEVELOPED RIGHT OVER THE AIRPORT. TOMORROW WILL BE
MUCH COOLER AGAIN AS ANOTHER AREA OF HIGH PRESSURE MOVES SOUTHWARD
TO OUR EAST WITH THE OVERALL TROUGH OVER THE MIDDLE CONUS. AN
INITIAL SURGE OF COOLER AIR HAS ALREADY MOVED INTO THE NORTHEAST
CORNER OF THE STATE AND THIS WILL BE FOLLOWED BY A REENFORCEMENT
OF COLDER AIR TONIGHT AS THE MAIN HIGH PUSHES SOUTHEASTWARD. MAIN
QUESTION FOR LATER TONIGHT INTO SUNRISE HOURS IS IF THE LOWER
LEVELS WILL BE MOIST ENOUGH FOR AREAS OF FOG AND LOWER CEILINGS.
SOMEWHAT OF A MIXED MESSAGE FROM THE MODELS...LATEST RAP AND HRRR
RUNS DO NOT SHOW ANY LOWER CLOUDS OR FOG WHILE GOESR PROVING
GROUND SYNTHETIC IMAGERY KEEPS THE LOWER CLOUD FARTHER NORTH. SREF
PROBABILITIES THOUGH ARE IN THE MID RANGE. FOR NOW HAVE KEPT FOG
OUT OF THE GRIDS BUT SOMETHING TO KEEP AN EYE ON FOR THE NEXT
SHIFT.
FOR TOMORROW WITH THE HIGH PRESSURE SLIDING WELL OFF TO OUR EAST
THE FLOW WILL QUICKLY TURN AROUND TO SOUTHERLY ON THE PLAINS AND
SHOULD SET UP A NICE DENVER CYCLONE. THIS COULD KEEP ANY LOWER CLOUDINESS
IN LONGER FROM BOULDER THROUGH DENVER COUNTIES...OTHERWISE DO
EXPECT A GENERALLY MOSTLY CLOUDY DAY ON THE PLAINS WITH LOTS OF
MID LEVEL CLOUDS FROM THE CALIFORNIA SYSTEM. THAT SYSTEM WEAKENS
RAPIDLY AS IT MOVES EASTWARD TONIGHT AND TOMORROW AND NOT
EXPECTING ANY PRECIPITATION TO MAKE IT ONTO THE PLAINS. IN THE
MOUNTAINS HAVE DELAYED THE START OF ANY SNOW A BIT OVERNIGHT THEN
GRADUALLY INCREASING CHANCES TOMORROW FOR A 1 TO 4 INCH TYPE
SNOW...MAYBE MORE IN SOME AREAS BUT OVERALL NOT A GREAT FLOW
PATTERN AND NOT VERY UNSTABLE EITHER SO AT LEAST THROUGH TOMORROW
NOT A LOT OF SNOW ANTICIPATED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 222 PM MST TUE DEC 2 2014
A WEAK DISTURBANCE WILL MOVE ACROSS COLORADO WEDNESDAY NIGHT WITH
A PERIOD OF SNOW WEDNESDAY EVENING OVER THE MOUNTAINS. SNOW WILL
DECREASING LATER IN THE NIGHT AS MOISTURE DEPTH BECOMES MORE
SHALLOW. EXPECT SNOWFALL AMOUNTS TO BE ON THE LIGHT SIDE WITH ONLY
MARGINAL LAPSE RATES. EXPECT HIGHER SNOWFALL AMOUNTS WILL EFFECT
ZONE 31 AND HIGHER AREAS OF ZONE 33.
THE FLOW ALOFT WILL BE MAINLY WESTERLY ON THURSDAY WHILE A SMALL
RIPPLE MOVES THROUGH THE FLOW ON THURSDAY NIGHT. OVERALL MOISTURE
DEPTH WILL REMAIN SHALLOW BUT A BRIEF BUMP UP ON POPS THURSDAY
NIGHT.
THE RIDGE ALOFT BUILDS INTO THE REGION FRIDAY NIGHT WITH MORE
DRYING IN THE MOUNTAINS BUT THIS WILL BE SHORT LIVED. THE NEXT
TROF WILL MOVE ACROSS THE REGION ON LATE SATURDAY AND SUNDAY. MUCH
OF THE ENERGY AND MOISTURE WILL OVER SOUTHERN COLORADO SO ONLY LOW
POPS NEEDED IN THE MOUNTAINS FOR NOW.
ACROSS LOWER ELEVATIONS...CONDITIONS WILL REMAIN DRY AND WARMER
FOR THURSDAY AND FRIDAY. MAYBE ONLY SLIGHT COOLING ON SUNDAY
FOLLOWING A WEAK COLD FRONT. DRY AND WARMER AGAIN FOR MONDAY AND
TUESDAY AS THE RIDGE ALOFT BUILDS INTO COLORADO.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON)
ISSUED AT 222 PM MST TUE DEC 2 2014
WINDS HAVE CERTAINLY BEEN TRICKY TODAY WITH DIA APPARENTLY RIGHT
BENEATH A SMALLER SCALE AREA OF LOW PRESSURE TODAY DEVELOPING IN
THE LEE OF THE ROCKIES. SURGE OF COOLER AIR NOW MOVING INTO THE
FAR NORTHEAST PLAINS. A REENFORCING SURGE WILL COME IN LATER
TONIGHT. STILL TRICKY AS TO HOW LOW THE CEILING GETS AS WELL AS
CHANCE OF SOME FOG AS WE GET TO VERY LATE TONIGHT FOR DIA AND FOR
THAT MATTER BJC AND APA. DENVER CYCLONE FLOW TOMORROW WILL LIKELY
MEAN ANOTHER DAY OF TRICKY WINDS AT DIA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SZOKE
LONG TERM...ENTREKIN
AVIATION...SZOKE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
108 PM EST TUE DEC 2 2014
.SYNOPSIS...
A WARM FRONT ARRIVES TONIGHT...RESULTING IN A WINTRY MIX OF
PRECIPITATION INTO EARLY WEDNESDAY MORNING...THEN CHANGING TO ALL
RAIN. MUCH MILDER WEATHER BRIEFLY RETURNS WEDNESDAY AFTERNOON.
THURSDAY BEGINS A TREND TOWARDS COLDER BUT DRY CONDITIONS. LOW
PRESSURE MAY BRING A PERIOD OF RAIN SOMETIME THIS WEEKEND WITH A
POSSIBLE WINTRY MIX ACROSS THE INTERIOR.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1 PM UPDATE...
LOW CLOUDS EXPANDING ACROSS SNE BUT LAPS SOUNDINGS SONTINUE TO
SHOW VERY DRY AIR IN THE 850-700 MB LAYER. RAP MOISTENS/SATURATES
THIS LAYER 21-23Z FROM BDL-PVD SO CURRENT FORECAST TIMING APPEARS
ON TRACK. LIGHT SNOW AND MIXED PRECIP WILL DEVELOP LATE AFTERNOON
FROM N CT TO S RI WITH MAINLY RAIN ALONG THE S COAST.
PREVIOUS DISCUSSION...
MAIN CHANGE TO FORECAST UPDATE WAS TO DELAY ONSET OF HIGHER POPS.
12Z SOUNDINGS SHOW EXTREMELY DRY AIR IN THE 850-700 MB LAYER AND
MODELS SUGGEST THE MOISTENING/SATURATION OF THIS LAYER DOES NOT
OCCUR UNTIL 21Z FROM BDL TO RI COAST THEN SLOWLY SPREADING N INTO
THE EARLY EVENING. BEST CHANCE OF PRECIP LATE THIS AFTERNOON WILL
BE ACROSS SW NEW ENG INTO S RI WITH MAINLY DRY CONDITIONS THROUGH
THE DAY NORTH OF THE PIKE.
PRECIP SHOULD BEGIN AS SNOW/SLEET MIX IN THE INTERIOR AND
RAIN/SLEET NEAR THE S COAST. MID LEVEL WARMING WILL BE ADVANCING
NORTH QUICKLY WHICH WILL LIMIT DURATION OF SNOW THIS EVENING WITH
MORE OF A SLEET/FZRA PROBLEM IN THE INTERIOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
*** WINTRY PRECIPITATION TO IMPACT PORTIONS OF SOUTHERN NEW
ENGLAND TONIGHT...
THE CENTRAL ISSUE WITH THIS PORTION OF THE FORECAST WILL BE
THERMAL PROFILES. NAM AND SREF SOLUTIONS ARE QUICKER TO WARM THE
OVERALL COLUMN THAN THE GFS AND ECMWF. ALL GUIDANCE DOES
EVENTUALLY BRING LOWER LEVEL TEMPERATURES ABOVE FREEZING HEADING
INTO WEDNESDAY. THUS...EXPECTING ALL WINTRY PRECIPITATION TO
EVENTUALLY TRANSITION TO ALL RAIN SOMETIME WEDNESDAY MORNING. THIS
WILL PLACE ADDITIONAL IMPORTANCE ON THE AMOUNT OF LOW LEVEL COLD
AIR WHICH STAYS ENTRENCHED WITHIN THE HIGHER TERRAIN OF WESTERN MA
AND SOUTHERN NH.
AT THIS POINT...THINKING THERE IS A SUFFICIENT CONCERN FOR A
PERIOD OF FREEZING RAIN TO WARRANT A WINTER WEATHER ADVISORY
ACROSS PORTIONS OF NORTHWESTERN MA AND SOUTHWEST NH. DECIDED TO
START THIS ADVISORY BEFORE THE START OF ANY PRECIPITATION. AM NOT
THINKING WE WILL ACHIEVE THE SNOWFALL CRITERION BY ITSELF.
STRONG WARM ADVECTION WILL HAVE ALLOWED MOST AREAS TO HAVE WARMED
ABOVE FREEZING BY DAYBREAK WEDNESDAY. HOWEVER...ISOLATED POCKETS
OF LIGHT FREEZING RAIN CAN/T BE RULED OUT THROUGH MID MORNING
ACROSS THE NORMALLY COLDEST LOCATIONS OF SOUTHWEST NH/NORTHWEST MA.
OTHERWISE...MUCH OF THE TIME FROM LATER WEDNESDAY MORNING INTO
THE AFTERNOON WILL END UP DRY...OTHER THAN A SPOT SHOWER OR TWO.
THIS A RESULT OF BETTER LIFT/DEEPER MOISTURE EXITS THE REGION.
HIGH TEMPS SHOULD RECOVER WELL INTO THE 40S ACROSS THE DISTANT
INTERIOR. MEANWHILE...ACROSS THE COASTAL PLAIN...850 TEMPS AROUND
+6C AND GOOD MIXING SHOULD YIELD HIGHS IN THE UPPER 50S TO LOWER
60S DESPITE AN ABUNDANCE OF CLOUDS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
* GRADUALLY TURNING COLDER THU AND FRI BUT DRY
* RAIN/WINTRY MIX POSSIBLE SOMETIME THIS WEEKEND BUT LOW
CONFIDENCE
OVERALL...00Z MODEL DATA IS IN FAIRLY GOOD AGREEMENT THROUGH THE
LONG TERM PERIOD. THERE ARE OF COURSE DISCREPANCIES IN TIMING BUT
THE GENERAL SYNOPTIC PATTERN IS IN DECENT AGREEMENT. HIGH PRESSURE
MOVING ACROSS NORTHERN NEW ENGLAND WILL ALLOW COLDER TEMPERATURES
TO FILTER INTO SOUTHERN NEW ENGLAND THURSDAY AND FRIDAY. LOW
PRESSURE MOVES THROUGH QUEBEC EARLY IN THE WEEKEND BRINGING A COLD
FRONT THROUGH SOUTHERN NEW ENGLAND SATURDAY. ANOTHER HIGH PRESSURE
THAN PASSES TO THE NORTH ALLOWING COLD AIR TO DRAIN DOWN AT THE
SURFACE RESULTING IN THE POTENTIAL FOR A WINTRY MIX OF
PRECIPITATION ACROSS THE INTERIOR AND RAIN ON THE COASTAL PLAIN.
DESPITE THE MODEL AGREEMENT...THERE IS STILL SOME UNCERTAINTY WITH
THE WEEKEND STORM GIVEN THE TIME FRAME AS WELL AS THE SENSITIVE
TEMPERATURE PROFILE. A DEGREE OR TWO CHANGE IN TEMPERATURE CAN
CHANGE THE TYPE OF PRECIPITATION EXPECTED.
WEDNESDAY NIGHT...MODELS HINT AT A FEW LEFTOVER SHOWERS EARLY IN
THE EVENING. OTHERWISE...EXPECT A DRYING TREND AS THE COLD FRONT
MOVES OFFSHORE BEFORE MIDNIGHT. TEMPERATURES DROP BEHIND THE
FRONT...THOUGH THE POTENTIAL FOR GUSTY WINDS MAY KEEP THEM FROM
BOTTOMING OUT.
THURSDAY AND FRIDAY...HIGH PRESSURE MOVES THROUGH NORTHERN NEW
ENGLAND. THIS WILL ALLOW COLD AIR DRAINAGE INTO SOUTHERN NEW
ENGLAND WITH TEMPERATURES COOLING OVER THESE TWO DAYS. STILL...
TEMPERATURES ARE EXPECTED TO BE RIGHT AROUND NORMAL FOR EARLY
DECEMBER.
SATURDAY THROUGH MONDAY...THIS PERIOD IS MOST UNCERTAIN WITH THE
POTENTIAL FOR BOTH A COLD FRONT AND A COASTAL STORM IN THE MODEL
SOLUTIONS. SATURDAY A COLD FRONT WILL MOVE THROUGH SOUTHERN NEW
ENGLAND WITH HIGH PRESSURE BUILDING ONCE AGAIN NORTH OF SOUTHERN
NEW ENGLAND. THEN MODELS HAVE A FEW TIMING/TRACK DIFFERENCES
WITH A POTENTIAL COASTAL LOW THAT COULD BRING PRECIPITATION TO THE
REGION SUNDAY AND MONDAY. THERE IS POTENTIAL THAT THIS COULD BE
A WINTRY MIX...PARTICULARLY ACROSS THE INTERIOR WHERE COLDER AIR
DRAINS FROM HIGH PRESSURE NORTH OF THE REGION AND WARMER AIR IN
THE MID LEVELS. ALONG THE COASTAL PLAIN...THIS IS MORE LIKELY TO
BE RAIN. HOWEVER...PLENTY OF UNCERTAINTY REMAINS WITH THIS
WEEKENDS FORECAST.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM /THROUGH TUESDAY NIGHT/...
THROUGH 00Z...LOWERING CIGS TO MVFR ACROSS MUCH OF THE REGION.
SNOW/MIXED PRECIP/RAIN DEVELOPS 22-00Z FROM BDL/BAF TO CAPE COD.
NORTHERN TERMINALS DRY THROUGH 00Z.
TONIGHT...OVERALL HIGH CONFIDENCE BUT LOWER CONFIDENCE ON TIMING
OF PRECIP TRANSITION. WIDESPREAD MVFR/IFR CONDITIONS AS WINTRY MIX
EXPANDS NORTH ACROSS SNE. PTYPE MAINLY RAIN S COAST TERMINALS WITH
SNOW TRANSITIONING TO PL/FZRA THEN RA INTERIOR. MINOR SNOW/ICE
ACCUMULATIONS LIKELY INTERIOR. ALL INTERIOR LOCATIONS SHOULD BE
ABOVE FREEZING BY 12Z WITH RAIN DOMINANT PTYPE. SE WIND GUSTS TO
25 KT DEVELOPING OVERNIGHT ON CAPE/ISLANDS.
WEDNESDAY...MODERATE CONFIDENCE. A MIX OF MVFR/IFR CONDITIONS
LIKELY. STEADY RAIN LIFTS TO THE NORTH IN THE MORNING BUT AREAS
OF DRIZZLE AND PATCHY FOG LIKELY. GUSTY SW WINDS DEVELOPING IN
THE COASTAL PLAIN WITH G25-30 KT LIKELY.
KBOS TERMINAL...MODERATE CONFIDENCE IN PRECIPITATION TIMING AND
TYPE. A BRIEF PERIOD OF SNOW OR SLEET POSSIBLE THIS EVENING AT
ONSET. NO FZRA EXPECTED.
KBDL TERMINAL...MODERATE CONFIDENCE IN PRECIPITATION TIMING AND
TYPE. SNOW/SLEET AT ONSET WITH A BRIEF PERIOD OF FZRA LIKELY THIS
EVENING BEFORE CHANGING TO ALL RAIN.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEDNESDAY NIGHT...HIGH CONFIDENCE. ANY LINGERING MVFR CONDITIONS
WILL QUICKLY IMPROVE TO VFR.
THURSDAY...HIGH CONFIDENCE. VFR.
FRIDAY...MODERATE CONFIDENCE. INCREASING CLOUDS WILL LEAD TO
MVFR/IFR CIGS ACROSS MUCH OF THE AREA.
SATURDAY...LOW CONFIDENCE. MVFR/IFR CIGS WITH RAIN SHOWERS SE AND
POSSIBLE WINTRY MIX NW WILL SLOWLY IMPROVE AFTER COLD FRONT MOVES
THROUGH REGION.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE.
TODAY...WINDS TURN EASTERLY WITH MAX GUSTS UP TO 25 KT SHIFTING
TO SOUTHERN WATERS. SMALL CRAFT ADVISORY SEAS CONTINUE OVER OPEN
WATERS. FOR SOME OF THE NEAR SHORE WATERS...AM EXPECTING
CONDITIONS TO DROP BELOW ADVISORY CRITERIA FOR A TIME...ONLY TO
INCREASE AGAIN LATER TODAY. DECIDED TO JUST MAINTAIN THE CURRENT
ADVISORIES FOR THE NEAR SHORE WATERS...RATHER THAN DROPPING THE
CURRENT ADVISORIES...JUST TO PUT THEM BACK IN PLACE LATER TODAY.
AFTER CONSIDERING THE LATEST OBSERVATIONS...DECIDED TO CANCEL THE
SMALL CRAFT ADVISORIES FOR NANTUCKET SOUND AND CAPE COD BAY EARLY.
TONIGHT...VEERING WINDS BECOME SOUTHERLY. GUSTS UP TO 25 KT
POSSIBLE AS LOW LEVEL WINDS INCREASE. EXPECTED INVERSION WILL
LIMIT THE MAGNITUDE OF GUSTS. VSBYS REDUCED IN RAIN AND FOG.
WEDNESDAY...SOUTHWEST WIND GUSTS TO 25 KNOTS EXPECTED AHEAD OF A
COLD FRONT
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEDNESDAY NIGHT AND THURSDAY...SOUTHWESTERLY WINDS AND SEAS
DIMINISH AS HIGH PRESSURE BUILDS NORTH OF THE WATERS. SMALL
CRAFT ADVISORIES LIKELY NECESSARY WEDNESDAY NIGHT.
FRIDAY...WINDS AND SEAS REMAIN BELOW SMALL CRAFT CRITERIA AS HIGH
PRESSURE CRESTS OVER THE WATERS.
SATURDAY...WINDS AND SEAS SLOWLY BUILD AS A COLD FRONT APPROACHES
THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WINTER WEATHER ADVISORY UNTIL 9 AM EST WEDNESDAY FOR MAZ002-
003-008-009.
NH...WINTER WEATHER ADVISORY UNTIL 11 AM EST WEDNESDAY FOR NHZ011-
015.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ235-237-
250-254>256.
&&
$$
SYNOPSIS...BELK/RLG
NEAR TERM...KJC
SHORT TERM...BELK
LONG TERM...RLG
AVIATION...KJC/RLG
MARINE...BELK/RLG
AREA FORECAST DISCUSSION
NWS NEW YORK NY
332 AM EST TUE DEC 2 2014
.SYNOPSIS...
CANADIAN HIGH PRESSURE BUILDS TO THE NORTH...THEN NORTHEAST
THROUGH TUESDAY. WEAK LOW PRESSURE OFF THE CAROLINA COAST ON
TUESDAY MOVES NORTH ACROSS THE REGION LATE TUESDAY NIGHT. ANOTHER
COLD FRONT PASSES WEDNESDAY AFTERNOON WITH STRONG HIGH PRESSURE
BUILDING IN FROM THURSDAY INTO FRIDAY. A STATIONARY FRONTAL BOUNDARY
WILL THEN SET UP NEAR THE AREA FOR THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MAIN AREA OF RAIN HAS PUSHED OFFSHORE. MINOR CHANGES MADE TO
REFLECT CURRENT OBSERVATIONS.
LOWS WEIGHED TOWARDS NAM AND HRRR 2-M TEMPERATURES WHICH
TYPICALLY FAIR BETTER IN THESE SHALLOW LOW LEVEL COLD AIR
SCENARIOS THAN MOS. GENERALLY AROUND FREEZING NYC METRO AND 20S
ELSEWHERE...EXCEPT AROUND 30 NEAR THE IMMEDIATE COAST AND MID 30S
NEAR KMTP.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
HIGH PRESSURE TRACKS INTO THE CANADIAN MARITIME PROVINCES
TUESDAY...WHICH QUICKLY VEERS WINDS TO EAST AS WEAK LOW PRESSURE
FORMS OFF THE COAST OF NORFOLK. ALL NWP APPEARS CONSISTENT WITH
LIGHT PRECIPITATION MOVING IN BEFORE SUNSET.
THERMAL PROFILES SUPPORT A BRIEF MIX AT THE START FOR THE COAST
WITH SNOW INLAND. THE SOUTHEAST VEERING FLOW QUICKLY WARMS TEMPS
ALOFT RESULTING IN A WINTRY MIX INLAND AS WELL BY 8 PM OR SO. THE
PROBLEM IS THAT THE COLD AIR WILL LIKELY HOLD AT THE SURFACE UNTIL
MIDNIGHT OR FEW HOURS AFTER SUCH THAT FREEZING RAIN BECOMES A
TRAVEL PROBLEM. WE DO EXPECT THE VAST MAJORITY OF THE INTERIOR TO
BE ABOVE FREEZING BY SUNRISE.
A WINTER WEATHER ADVISORY WILL LIKELY BE NEEDED FOR THE INTERIOR.
BASED ON COLLABORATION WITH SURROUNDING NWS OFFICES...WE WILL ISSUE
THESE ON THE MIDNIGHT SHIFT (ASSUMING THE FORECAST DOES NOT
CHANGE).
ACCUMULATION OF SNOW OVER THE INTERIOR IS LESS THAN AN INCH AND
PROBABILISTIC SNOW DATA HAS BEEN ISSUED. ICE ACCUMULATION OF LESS
THAN A TENTH OF AN INCH OR LESS IS FORECAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE UPPER JET WILL ALLOW FOR GENERALLY ZONAL FLOW ALOFT THROUGH
THE LONG TERM.
ON WED...THE CWA WILL ENTER THE WARM SECTOR BRIEFLY AS A WARM
FRONT LIFTS TO THE N. THIS WILL CUT OFF THE STEADY RAIN...BUT
ALLOW FOR SOME POCKETS OF LIGHT RAIN AND DZ TO DEVELOP. SOME
PATCHY FG WILL ALSO BE POSSIBLE. TEMPS ABOUT 5 DEGREES ABOVE
NORMAL.
THE COLD FRONT COMES THROUGH WED NIGHT. THIS USHERS THE HIGHER
HUMIDITY OFFSHORE...AND CLEARS OUT THE SKIES FOR THU. TEMPS ON THU
BELOW CLIMATOLOGY BY A FEW DEGREES.
THE CWA IS THEN IN THE BATTLE ZONE BETWEEN THE DEPARTING 1040S
HIGH OVER ERN CANADA...AND SOUTHWESTERLY FLOW ALOFT PRODUCING
SOME WAA AND WEAK MOISTURE TRANSPORT. THIS WILL KEEP IT MAINLY
CLOUDY FRI THROUGH THE WEEKEND...WITH PERIODS OF PRECIPITATION.
ALL AREAS SUSCEPTIBLE TO SNOW OR A WINTRY MIX TO START OUT THE
PRECIPITATION FRI...THEN THE COASTS AND CITY APPEAR TO TRANSITION
TO MAINLY ALL RAIN FOR THE REMAINDER OF THE PERIOD. THE INTERIOR
WILL STRUGGLE BOTH TO WARM INITIALLY...AND THEREAFTER STAY ABOVE
FREEZING. AS A RESULT...A WINTRY MIX HAS BEEN INCLUDED IN THE
FORECAST THROUGH THE WEEKEND.
THE UNSETTLED PATTERN MAY END WITH WEAK LOW PRESSURE DEVELOPING
AND THEN FINALLY TRACKING OUT TO SEA. THE ROUGH TIMING FOR THIS IS
MON...ALTHOUGH IT IS TOO FAR OUT TO PIN DOWN AT THIS TIME. THIS
SCENARIO WOULD RESULT IN MORE RAIN AT THE COASTS AND A MIX AGAIN
ACROSS THE INTERIOR. BECAUSE THIS SETUP WOULD BE MORE CONDUCIVE TO
COOLING ALOFT...THE INTERIOR WOULD RUN THE THREAT FOR A CHANGEOVER
TO ALL SNOW WITH SOME ACCUMULATIONS.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
***HIGH IMPACT EVENT THIS AFTERNOON***
VFR AND NORTHERLY WINDS CONTINUE EARLY THIS MORNING WITH SOME
OCCASIONAL GUSTS IN THE UPPER TEENS TO NEAR 20 KT. GUSTS IN THE
UPPER TEENS ARE EXPECTED AFTER SUNRISE...ALTHOUGH MAY BE MORE
OCNL...ESPECIALLY OUTSIDE OF NYC.
A WINTRY MIX OF PCPN IS EXPECTED TO OVERSPREAD THE REGION DURING THE
AFTERNOON. A BRIEF PERIOD OF SN/PL AT THE COAST TO START...CHANGING
TO PLAIN RAIN IN THE EARLY EVE. KSWF SHOULD SEE A FEW HOURS OF -SN
AN IS THE ONLY TERMINAL EXPECTED TO HAVE ANY ACCUMULATION...LESS
THAN AN INCH BEFORE MIXING WITH PL AND FZRA DURING THE FIRST HALF OF
THE EVENING...AND THEN PLAIN RAIN AROUND MIDNIGHT OR SO. CONDITIONS WILL
QUICKLY DROP TO IFR ONCE THE SNOW STARTS...WITH A MORE GRADUAL
TRANSITION TO MVFR THEN IFR AT THE COAST WITH THE WINTRY MIX. TIMING
OF PCPN...CHANGEOVER OF P-TYPES AND IFR CONDS MAY BE A FEW HOURS OFF.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGH CONFIDENCE FORECAST THROUGH THE MORNING.
AMENDMENTS POSSIBLE THIS AFTERNOON FOR CHANGING FLIGHT CATEGORIES AND
P-TYPE CHANGES.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE FORECAST THROUGH THE MORNING.
AMENDMENTS POSSIBLE THIS AFTERNOON FOR CHANGING FLIGHT CATEGORIES AND
P-TYPE CHANGES.
KEWR FCSTER COMMENTS: HIGH CONFIDENCE FORECAST THROUGH THE MORNING.
AMENDMENTS POSSIBLE THIS AFTERNOON FOR CHANGING FLIGHT CATEGORIES AND
P-TYPE CHANGES.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES
SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE FORECAST THROUGH THE MORNING.
AMENDMENTS POSSIBLE THIS AFTERNOON FOR CHANGING FLIGHT CATEGORIES AND
P-TYPE CHANGES.
KHPN FCSTER COMMENTS: HIGH CONFIDENCE FORECAST THROUGH THE MORNING.
AMENDMENTS POSSIBLE THIS AFTERNOON FOR CHANGING FLIGHT CATEGORIES AND
P-TYPE CHANGES.
KISP FCSTER COMMENTS: HIGH CONFIDENCE FORECAST THROUGH THE MORNING.
AMENDMENTS POSSIBLE THIS AFTERNOON FOR CHANGING FLIGHT CATEGORIES AND
P-TYPE CHANGES.
.OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...
.TUE NIGHT...IFR OR LOWER IN RAIN.
.WED...SUB-VFR POSSIBLE IN -RA/DZ/FG IN THE MORNING. IMPROVING
CONDS LATE.
.THU...VFR.
.FRI...LIGHT RAIN AND/OR SNOW POSSIBLE IN THE AFTERNOON.
.FRI NIGHT...CHANCE FOR RAIN ALONG THE COAST AND
SNOW/SLEET/FREEZING RAIN ACROSS INTERIOR.
.SAT...CHANCE FOR RAIN ALONG THE COAST AND SNOW/SLEET/FREEZING
RAIN FOR INTERIOR IN THE MORNING...THEN CHANCE FOR RAIN IN THE
AFTERNOON.
&&
.MARINE...
GUSTS EVERYWHERE EXCEPT THE OCEAN ZONES HAVE FALLEN BELOW 25 KT.
THEREFORE THE SMALL CRAFT ADVISORIES FOR THE SOUND...NEW YORK
HARBOR...SOUTH SHORE BAYS...AND PECONIC AND GARDINER BAYS HAVE
BEEN ALLOWED TO EXPIRE. SCA REMAIN OVER THE OCEAN ZONES.
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
LOOKING UPSTREAM...APPEARS WIND GUSTS SHOULD FALL BELOW SCA LEVELS
ON NON-OCEAN WATERS AROUND MIDNIGHT...SO CURRENT HEADLINES APPEAR
ON TRACK.
SCA CONDITION REMAIN ON THE WATERS ON TUESDAY AND WILL LIKELY
NEED EXTENDING INTO TUESDAY NIGHT.
WINDS INCREASE AHEAD OF A COLD FRONT WED. SCA SPEEDS
LIKELY...ESPECIALLY ERN WATERS. THE WINDS SHIFT WITH THE FRONT
WED NIGHT...THEN DECREASE BELOW SCA LEVELS THU. WINDS AND SEAS
WILL THEN LIKELY REMAIN BELOW SCA LEVELS TIL SUN.
THEREAFTER...THE POTENTIAL DEVELOPMENT OF LOW PRESSURE MAY BRING
WINDS AND SEAS TO SCA LEVELS...PARTICULARLY ON THE OCEAN.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH TUESDAY
MORNING.
QPF LATE DAY TUE INTO WED MORNING SHOULD BE ABOUT A THIRD
OF AN INCH. A WINTRY MIX OVER THE INTERIOR IS FORECAST AND NO
HYDROLOGIC IMPACTS ARE EXPECTED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...JMC/MALOIT/TONGUE
NEAR TERM...JP
SHORT TERM...TONGUE
LONG TERM...JMC
AVIATION...BC
MARINE...JMC/MALOIT/TONGUE
HYDROLOGY...TONGUE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1215 AM EST TUE DEC 2 2014
.SYNOPSIS...
CANADIAN HIGH PRESSURE BUILDS TO THE NORTH...THEN NORTHEAST
THROUGH TUESDAY. WEAK LOW PRESSURE OFF THE CAROLINA COAST ON
TUESDAY MOVES NORTH ACROSS THE REGION LATE TUESDAY NIGHT. ANOTHER
COLD FRONT PASSES WEDNESDAY AFTERNOON WITH STRONG HIGH PRESSURE
BUILDING IN FROM THURSDAY INTO FRIDAY. A STATIONARY FRONTAL BOUNDARY
WILL THEN SET UP NEAR THE AREA FOR THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MAIN AREA OF RAIN HAS PUSHED OFFSHORE. MINOR CHANGES MADE TO
REFLECT CURRENT OBSERVATIONS.
LOWS WEIGHED TOWARDS NAM AND HRRR 2-M TEMPERATURES WHICH
TYPICALLY FAIR BETTER IN THESE SHALLOW LOW LEVEL COLD AIR
SCENARIOS THAN MOS. GENERALLY AROUND FREEZING NYC METRO AND 20S
ELSEWHERE...EXCEPT AROUND 30 NEAR THE IMMEDIATE COAST AND MID 30S
NEAR KMTP.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
HIGH PRESSURE TRACKS INTO THE CANADIAN MARITIME PROVINCES
TUESDAY...WHICH QUICKLY VEERS WINDS TO EAST AS WEAK LOW PRESSURE
FORMS OFF THE COAST OF NORFOLK. ALL NWP APPEARS CONSISTENT WITH
LIGHT PRECIPITATION MOVING IN BEFORE SUNSET.
THERMAL PROFILES SUPPORT A BRIEF MIX AT THE START FOR THE COAST
WITH SNOW INLAND. THE SOUTHEAST VEERING FLOW QUICKLY WARMS TEMPS
ALOFT RESULTING IN A WINTRY MIX INLAND AS WELL BY 8 PM OR SO. THE
PROBLEM IS THAT THE COLD AIR WILL LIKELY HOLD AT THE SURFACE UNTIL
MIDNIGHT OR FEW HOURS AFTER SUCH THAT FREEZING RAIN BECOMES A
TRAVEL PROBLEM. WE DO EXPECT THE VAST MAJORITY OF THE INTERIOR TO
BE ABOVE FREEZING BY SUNRISE.
A WINTER WEATHER ADVISORY WILL LIKELY BE NEEDED FOR THE INTERIOR.
BASED ON COLLABORATION WITH SURROUNDING NWS OFFICES...WE WILL ISSUE
THESE ON THE MIDNIGHT SHIFT (ASSUMING THE FORECAST DOES NOT
CHANGE).
ACCUMULATION OF SNOW OVER THE INTERIOR IS LESS THAN AN INCH AND
PROBABILISTIC SNOW DATA HAS BEEN ISSUED. ICE ACCUMULATION OF LESS
THAN A TENTH OF AN INCH OR LESS IS FORECAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE UPPER JET WILL ALLOW FOR GENERALLY ZONAL FLOW ALOFT THROUGH
THE LONG TERM.
ON WED...THE CWA WILL ENTER THE WARM SECTOR BRIEFLY AS A WARM
FRONT LIFTS TO THE N. THIS WILL CUT OFF THE STEADY RAIN...BUT
ALLOW FOR SOME POCKETS OF LIGHT RAIN AND DZ TO DEVELOP. SOME
PATCHY FG WILL ALSO BE POSSIBLE. TEMPS ABOUT 5 DEGREES ABOVE
NORMAL.
THE COLD FRONT COMES THROUGH WED NIGHT. THIS USHERS THE HIGHER
HUMIDITY OFFSHORE...AND CLEARS OUT THE SKIES FOR THU. TEMPS ON THU
BELOW CLIMATOLOGY BY A FEW DEGREES.
THE CWA IS THEN IN THE BATTLE ZONE BETWEEN THE DEPARTING 1040S
HIGH OVER ERN CANADA...AND SOUTHWESTERLY FLOW ALOFT PRODUCING
SOME WAA AND WEAK MOISTURE TRANSPORT. THIS WILL KEEP IT MAINLY
CLOUDY FRI THROUGH THE WEEKEND...WITH PERIODS OF PRECIPITATION.
ALL AREAS SUSCEPTIBLE TO SNOW OR A WINTRY MIX TO START OUT THE
PRECIPITATION FRI...THEN THE COASTS AND CITY APPEAR TO TRANSITION
TO MAINLY ALL RAIN FOR THE REMAINDER OF THE PERIOD. THE INTERIOR
WILL STRUGGLE BOTH TO WARM INITIALLY...AND THEREAFTER STAY ABOVE
FREEZING. AS A RESULT...A WINTRY MIX HAS BEEN INCLUDED IN THE
FORECAST THROUGH THE WEEKEND.
THE UNSETTLED PATTERN MAY END WITH WEAK LOW PRESSURE DEVELOPING
AND THEN FINALLY TRACKING OUT TO SEA. THE ROUGH TIMING FOR THIS IS
MON...ALTHOUGH IT IS TOO FAR OUT TO PIN DOWN AT THIS TIME. THIS
SCENARIO WOULD RESULT IN MORE RAIN AT THE COASTS AND A MIX AGAIN
ACROSS THE INTERIOR. BECAUSE THIS SETUP WOULD BE MORE CONDUCIVE TO
COOLING ALOFT...THE INTERIOR WOULD RUN THE THREAT FOR A CHANGEOVER
TO ALL SNOW WITH SOME ACCUMULATIONS.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
***HIGH IMPACT EVENT TUESDAY AFTERNOON AND EVENING***
NLY WINDS CONTINUE OVERNIGHT. GUSTS HAVE INCREASED A BIT IN
FREQUENCY THE PAST HOUR OR TWO...BUT STILL NOT CONVINCED THEY WILL
CONTINUE ALL NIGHT. THEREFORE...HAVE LEFT THEM OUT OF THE 06Z TAFS
UNTIL MORNING. VFR CONDS CONTINUE THROUGH THE MORNING. GUSTS IN
THE UPPER TEENS ARE EXPECTED TO RETURN AFT SUNRISE...ALTHOUGH MAY
BE MORE OCNL...ESPECIALLY OUTSIDE OF NYC.
A WINTRY MIX OF PCPN IS EXPECTED TO OVERSPREAD THE REGION DURING
THE AFTN. A BRIEF PERIOD OF SN/PL AT THE COAST TO START...CHANGING
TO PLAIN RAIN IN THE EARLY EVE. KSWF SHOULD SEE A FEW HOURS OF
-SN AN IS THE ONLY TERMINAL EXPECTED TO HAVE ANY
ACCUMULATION...ALTHOUGH LESS THAN AN INCH BEFORE MIXING WITH PL
AND FZRA DURING THE FIRST HALF OF THE EVE...AND THEN PLAIN RAIN
AROUND MIDNIGHT OR SO. CONDS WILL QUICKLY DROP TO IFR ONCE THE
SNOW STARTS...WITH A MORE GRADUAL TRANSITION TO MVFR THEN IFR AT
THE COAST WITH THE WINTRY MIX. TIMING OF PCPN...CHANGEOVER OF
P-TYPES AND IFR CONDS MAY BE A FEW HOURS OFF.
.OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...
.TUE NIGHT...IFR OR LOWER IN RAIN.
.WED...SUB-VFR POSSIBLE IN -RA/DZ/FG IN THE MORNING. IMPROVING
CONDS LATE.
.THU...VFR.
.FRI...LIGHT RAIN AND/OR SNOW POSSIBLE IN THE AFTERNOON.
.FRI NIGHT...CHANCE FOR RAIN ALONG THE COAST AND
SNOW/SLEET/FREEZING RAIN ACROSS INTERIOR.
.SAT...CHANCE FOR RAIN ALONG THE COAST AND SNOW/SLEET/FREEZING
RAIN FOR INTERIOR IN THE MORNING...THEN CHANCE FOR RAIN IN THE
AFTERNOON.
&&
.MARINE...
GUSTS EVERYWHERE EXCEPT THE OCEAN ZONES HAVE FALLEN BELOW 25 KT.
THEREFORE THE SMALL CRAFT ADVISORIES FOR THE SOUND...NEW YORK
HARBOR...SOUTH SHORE BAYS...AND PECONIC AND GARDINER BAYS HAVE
BEEN ALLOWED TO EXPIRE. SCA REMAIN OVER THE OCEAN ZONES.
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
LOOKING UPSTREAM...APPEARS WIND GUSTS SHOULD FALL BELOW SCA LEVELS
ON NON-OCEAN WATERS AROUND MIDNIGHT...SO CURRENT HEADLINES APPEAR
ON TRACK.
SCA CONDITION REMAIN ON THE WATERS ON TUESDAY AND WILL LIKELY
NEED EXTENDING INTO TUESDAY NIGHT.
WINDS INCREASE AHEAD OF A COLD FRONT WED. SCA SPEEDS
LIKELY...ESPECIALLY ERN WATERS. THE WINDS SHIFT WITH THE FRONT
WED NIGHT...THEN DECREASE BELOW SCA LEVELS THU. WINDS AND SEAS
WILL THEN LIKELY REMAIN BELOW SCA LEVELS TIL SUN.
THEREAFTER...THE POTENTIAL DEVELOPMENT OF LOW PRESSURE MAY BRING
WINDS AND SEAS TO SCA LEVELS...PARTICULARLY ON THE OCEAN.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH TUESDAY
MORNING.
QPF LATE DAY TUE INTO WED MORNING SHOULD BE ABOUT A THIRD
OF AN INCH. A WINTRY MIX OVER THE INTERIOR IS FORECAST AND NO
HYDROLOGIC IMPACTS ARE EXPECTED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...JMC/MALOIT/TONGUE
NEAR TERM...JP
SHORT TERM...TONGUE
LONG TERM...JMC
AVIATION...24
MARINE...JMC/MALOIT/TONGUE
HYDROLOGY...TONGUE
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
949 PM EST WED DEC 3 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST THROUGH THE AREA THIS EVENING. A
STRONG HIGH PRESSURE SYSTEM OVER THE MIDWEST THIS AFTERNOON WILL
BUILD TO OUR NORTH THURSDAY, REACHING THE CANADIAN MARITIMES ON
FRIDAY. A LOW PRESSURE SYSTEM IS FORECAST TO TRACK FROM THE
SOUTHERN PLAINS TO THE SOUTHERN APPALACHIANS SATURDAY, BEFORE
EMERGING OFF THE MID-ATLANTIC COAST LATE IN THE WEEKEND INTO
MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
NOT MUCH CHANGE TO THE GRIDS THIS EVENING THOUGH THE CAA PUSH
BEHIND THE FRONT HAS BEEN LESS THAN STELLAR. HAVE DECREASED THE
WINDS AND THE GUSTS A BIT DOWNWARD, FOR THE TIME BEING. THE RAP IS
STILL SHOWING THE LOW-LEVEL CAA PUSH OVER THE NEXT COUPLE OF HOURS
WITH 925MB WINDS REACHING THE 30 KNOT MARK, SO DO NOT THINK WE
WILL BE COMPLETELY GUST FREE TONIGHT. OTHERWISE WE WILL REMAIN DRY
TONIGHT WITH CLEARING SKIES OVERHEAD. LOWS WILL RANGE FROM THE LOW
20S IN THE FAR NORTH TO THE LOW 30S SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
GREAT LAKES THURSDAY MORNING WILL MIGRATE NORTHEAST AND BECOME
CENTERED OVER SOUTHERN QUEBEC BY THURSDAY EVENING. EXPECT CLEAR
SKIES FOR MUCH OF THE DAY, WITH SOME HIGH CLOUDS MOVING IN FROM THE
SOUTHWEST LATER IN THE DAY. WINDS SHOULD BE FAIRLY BENIGN AS THE
CENTER OF THE HIGH MOVES BY JUST TO OUR NORTH. HIGH TEMPS WILL RANGE
FROM THE MID 40S IN THE FAR NORTH TO MID 40S SOUTH, WHICH IS NEAR OR
JUST SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE 1040 MB ARCTIC HIGH TO OUR NORTH WILL QUICKLY SHIFT EAST FROM
MONTREAL THURSDAY EVENING TO THE CANADIAN MARITIMES ON FRIDAY. THE
COLD AND DRY AIR NEAR THE SURFACE THAT DRAINED DOWN THE EASTERN
SEABOARD WILL ALSO START TO RETREAT AS THE HIGH MOVES TOWARD THE
COAST AND LIGHT ONSHORE FLOW DEVELOPS. A LOW-LEVEL RIDGE IS
FORECAST TO BUILD ALONG THE SOUTHEAST COAST DURING THIS TIME.
DEVELOPING SWLY RETURN FLOW AROUND THE RIDGE WILL PRODUCE AN
OVERRUNNING SETUP ALONG A WARM FRONT BOUNDARY. THERE ARE SOME
MODEL DIFFERENCES REGARDING HOW QUICKLY PRECIP OVERSPREADS THE
AREA FROM SOUTH TO NORTH LATE FRIDAY. WE FAVORED AN EARLIER
(AFTERNOON) ONSET GIVEN THE NOTABLE ISENTROPIC LIFT IN THE LOW AND
MID LEVELS.
SIMILAR TO THE EVENT YESTERDAY, A PERIOD OF LIGHT WINTRY PRECIP
(SNOW/SLEET) AT THE ONSET IS POSSIBLE FRIDAY AFTERNOON INTO FRIDAY
NIGHT AWAY FROM THE COAST BUT IT WOULD ONLY BE BRIEF TOWARD THE
I-95 CORRIDOR AS WARM AIR ALOFT MOVES IN AND TEMPS REMAIN ABOVE
FREEZING. OUR NWRN ZONES WILL BE DEEPER INTO THE COLD AIR, SO THE
EVENTUAL TRANSITION TO RAIN WILL TAKE LONGER AND THE THUS THE
POTENTIAL FOR MEASURABLE (ALBEIT LIGHT) SNOW/SLEET ACCUMULATION
ARE GREATER. ALSO LIKE YESTERDAY`S EVENT, THE CAD SETUP WILL
ALREADY HAVE BEEN ESTABLISHED PRIOR TO THE ONSET, SO THE SHALLOW
LAYER OF COLD AIR WILL BE MORE RESISTANT TO EROSION DUE TO THE
HILLY TERRAIN IN NE PA/NW NJ. THE 12Z GUIDANCE SHOWS SURFACE TEMPS
RISING TO ABOVE FREEZING IN THESE NW ZONES AROUND THE SAME TIME
THE WARM FRONT PASSES THROUGH AND THE STEADIER PRECIP MOVES IN,
RESULTING IN A QUICK CHANGEOVER TO RAIN. HOWEVER, MODELS TEND TO
UNDERESTIMATE THE RESISTANCE OF THE COLD AIR THAT IS TRAPPED NEAR
THE SURFACE IN THESE CAD SETUPS, SO WE WILL CONTINUE TO HIGHLIGHT
A POTENTIAL FOR A PERIOD OF FREEZING RAIN FRIDAY NIGHT ALONG AND
NORTH OF I-78.
A PROGRESSIVE SHORTWAVE TROUGH EMBEDDED IN THE ZONAL FLOW PATTERN IS
EXPECTED TO TRACK FROM THE OH-TN VALLEYS TO THE MID-ATLANTIC
REGION ON SATURDAY. THE SURFACE REFLECTION OF THE LOW IS FORECAST
TO CROSS THE SOUTHERN APPALACHIANS LATE IN THE DAY. RAIN IS LIKELY
ON SATURDAY WITH THE AREA STILL SITUATED IN MOIST PRE-FRONTAL WARM
SECTOR.
FORECAST UNCERTAINTY INCREASES SIGNIFICANTLY FOR THE SECOND HALF OF
THE WEEKEND AND EARLY NEXT WEEK. THE 12Z ECMWF AND CANADIAN
OPERATIONAL MODELS INDICATE A MUCH MORE AMPLIFIED PATTERN OVER THE
CONUS COMPARED TO THE GFS/GEFS MEAN. THE FORMER TWO MODELS SHOW A
STRONG RIDGE DEVELOPING OVER THE WESTERN CONUS AND DOWNSTREAM
AMPLIFICATION OF THE EASTERN CONUS TROUGH. MEANWHILE THE GFS-BASED
RUNS ARE MUCH FLATTER. BOTH THE ECMWF AND CANADIAN DEVELOP A REX
BLOCK ALONG THE EAST COAST WITH YET ANOTHER STRONG (1040+ MB)
SURFACE HIGH BUILDING TO OUR NORTH ACROSS EASTERN CANADA AND LOW
PRESSURE EMERGING OFF THE MID-ATLANTIC COAST. IN THESE SOLUTIONS,
THE LOW MEANDERS OFFSHORE WHILE GRADUALLY DEEPENING AS A RESULT
OF THE BLOCKING PATTERN. THE GFS WAS OF COURSE MUCH MORE PROGRESSIVE
WITH ANY POTENTIAL LOW HEADING OUT TO SEA. IF THE MORE AMPLIFIED
SCENARIO PANS OUT, THEN SUNDAY AND MONDAY WILL BE UNSETTLED FOR
OUR FORECAST AREA WITH A PROLONGED PERIOD OF PRECIP AND GUSTY
WINDS ALONG THE COAST. DEPENDING ON THE TRACK OF THE LOW, THERE
MAY ALSO BE WINTRY PTYPE ISSUES AWAY FROM THE COAST WITH COLDER
AIR WRAPPING AROUND THE BACKSIDE OF THE LOW. THERE IS STILL MUCH
UNCERTAINTY THIS FAR OUT TO START SPECIFYING PTYPES SO STAY TUNED
FOR UPDATES.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TONIGHT - THURSDAY...VFR. GUSTY NORTHWEST WINDS LATE THIS EVENING
WILL SUBSIDE WITH CLEARING SKIES. WINDS VEER TOWARDS THE NORTH
TOMORROW EVENING.
OUTLOOK...
THURSDAY NIGHT...VFR CONDITIONS EXPECTED.
FRIDAY...VFR CONDITIONS IN THE MORNING MAY TRANSITION TO MVFR IN THE
AFTN AS PRECIP DEVELOPS FROM S TO N. IF PRECIP COMES IN EARLIER THAT
CURRENTLY EXPECTED, THEN IFR MAY DEVELOP LATE IN THE DAY. BRIEF
PERIOD OF SN/IP AT THE ONSET BEFORE IT QUICKLY CHANGES OVER TO RA.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...PERIODS OF RA LIKELY. IFR LIKELY
FRIDAY NIGHT. CONDITIONS MAY TRY TO IMPROVE TO MVFR DURING THE DAY
SATURDAY BUT IMPROVEMENT MAY NOT OCCUR UNTIL THE COLD FROPA SOMETIME
SATURDAY NIGHT.
SUNDAY THROUGH MONDAY...LOW FORECAST CONFIDENCE. THERE IS A
POTENTIAL FOR A COASTAL STORM TO IMPACT THE TERMINALS DURING THIS
TIME, RESULTING IN IFR CONDITIONS AND PRECIP. RAIN MAY MIX WITH OR
CHANGE TO SN/IP IN THIS SETUP BY MONDAY ESPECIALLY OUT TOWARD
RDG/ABE. NE FLOW WOULD ALSO BECOME GUSTY.
&&
.MARINE...
THE SMALL CRAFT ADVISORY ON THE DELAWARE BAY WAS EXTENDED THROUGH
THE OVERNIGHT HOURS TO MATCH THE END TIME ON THE OCEAN. IT`S VERY
POSSIBLE THIS ENDING TIME IS TOO LONG, BUT LATER SHIFTS CAN CANCEL
IT EARLY IF CONDITIONS WARRANT. SEAS OF 2 TO 3 FEET ARE EXPECTED
ON THE BAY, WITH SEAS UP TO 5 FEET (OR MAYBE JUST A LITTLE HIGHER)
ON THE OCEAN. AS SURFACE HIGH PRESSURE MOVES NORTHEAST FROM THE
LOWER GREAT LAKES AREA, WINDS AND SEAS WILL CALM DOWN BELOW SCA
CONDITIONS ON THE BAY AND OCEAN TOWARD MORNING.
OUTLOOK...
THURSDAY NIGHT THROUGH SATURDAY...NO MARINE HAZARDS EXPECTED.
SATURDAY NIGHT THROUGH MONDAY...MODELS ARE HINTING AT THE
DEVELOPMENT OF A COASTAL LOW NEARBY. N-NE WINDS AROUND THE LOW WOULD
INTENSIFY AS A RESULT. OFFICIAL FORECAST INDICATES SCA WINDS AND
SEAS. HOWEVER, GALES WOULD BE POSSIBLE IF THE LOW DOES DEEPEN
RAPIDLY OFF THE COAST.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST THURSDAY FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...HEAVENER/MIKETTA
SHORT TERM...MIKETTA
LONG TERM...KLEIN
AVIATION...HEAVENER/KLEIN/MIKETTA
MARINE...KLEIN/MIKETTA
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
935 AM EST TUE DEC 2 2014
.DISCUSSION...
LL MOISTURE CONFINED IN THE LOWER LEVELS (BLO H85) COUPLED WITH
ENHANCED CLOUD LINES EMANATING WITHIN IN PERTURBATIONS IN STOUT LL
ONSHORE FLOW WL CONTINUE TO PRODUCE SOME MARINE AND MEASURABLE
COASTAL SHOWERS DURING TEH REMAINDER OF THE DAY. SHOWERS WILL HAVE
CAPABILITY OF PRODUCING MEASURABLE RAIN ACROSS THE INTERIOR MAINLY
FROM ORANGE COUNTY SWD. COASTAL SITES MAY SEE UPWARDS OF .1 TO .2
INCHES LOCALLY WITH INLAND AREAS MAINLY LESS THAN 01 FROM ACTIVITY.
THE FORECAST IS IN GOOD SHAPE ATTM AND NO UPDTS ARE PLANNED.
&&
.AVIATION...
TEMPO BKN040 WITH ISOLATED/SCT LIGHT RAIN SHOWERS THROUGH 03/00Z
THEN ISOLATED AT THE COAST AFTER 03/00Z. WILL KEEP VCSH IN TAFS.
&&
.MARINE...
XMR 915 MHZ PROFILER NETWORK ALONG WITH THE SOUNDING FROM THE SAME
LOCATION SHOW 25 KT WINDS IN THE LOWER 3K FT. LTST RUC SHORT TERM
GUID FROM SFC TO H925 SUGGEST CONTINUATION OF AT LEAST 20 TO 25 KT
THROUGH THE BL FOR THE REMAINDER OF THE DAY FOR MOST OF THE COAST
ASIDE FROM THE VOLUSIA AREA. WITH LTST SFC AND BUOY OBS INDICATING
THE SAME HAVE EXPENDED THE SCA TO COVER THE NEARSHORE WATERS FROM
THE VOLUSIA AND BREVARD LINE SOUTHWARD. SEA HGHTS HAVE PRETTY MUCH
BECOME FULLY ARISEN OVER THE ADVISORY AREA WITH 5 TO 7 FT BEING
INDICATED.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY TO 10 AM EST
WEDNESDAY FOR WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD
COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS FROM SEBASTIAN
INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-WATERS FROM
VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM
OFFSHORE.
SMALL CRAFT ADVISORY TO 10 AM EST WEDNESDAY FOR WATERS FROM
VOLUSIA BREVARD COUNTY LINE TO JUPITER INLET OUT TO 20 NM.
&&
$$
JP/WU
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
942 AM EST TUE DEC 2 2014
.SYNOPSIS...
WEAK COLD FRONT WILL STRUGGLE TO CROSS THE MOUNTAINS TODAY AS HIGH
PRESSURE OVER NEW ENGLAND WILL PUSH WEDGE TYPE CONDITIONS INTO THE
AREA FROM THE NORTH. THE FRONTAL REMAINS WILL PERSIST OVER THE
AREA INTO THE WEEKEND WHEN THE NEXT SYSTEM WILL PUSH THE FRONT
THROUGH THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
TO THE WEST...A WEAK COLD FRONT WILL CONTINUE STRUGGLING TO CROSS
THE MOUNTAINS. WEDGE FRONT TO THE NORTH SLOWLY PUSHING SOUTHWARD INTO
THE NORTHERN MIDLANDS. GIVEN WEAK ISENTROPIC LIFT...HAVE SCALED
BACK TIMING OF POPS FOR THE NORTHERN MIDLANDS UNTIL THIS EVENING.
12Z NAM AND RUC MODELS INDICATE RAIN ALONG THE COAST COULD MOVE
INTO THE WESTERN MIDLANDS THIS AFTERNOON...THOUGH MEASURABLE RAIN
NOT EXPECTED. STILL EXPECT CLOUDS TO INCREASE THIS AFTERNOON.
HIGH TEMPERATURES CONTINUE TO REFLECT THE STRUGGLES OF THE FRONT
AND WEDGE CONDITIONS. HAVE RANGED AFTERNOON HIGHS FROM NEAR 60
ALONG THE NC LINE TO THE LOWER 70S ACROSS THE CSRA.
WEDGE CONDITIONS WILL CONTINUE BUILDING INTO THE FORECAST AREA
OVERNIGHT AS LOW LEVEL WINDS TURN EAST TO SOUTHEASTERLY USHERING
ADDITIONAL MOISTURE INTO THE REGION. EXPECT CLOUDS TO INCREASE
OVERNIGHT. HOWEVER WITH WEAK DYNAMICS AND PWAT VALUES OF 1 INCH
OR LESS RAIN CHANCES WILL BE LIMITED. HAVE MAINTAINED SLIGHT
CHANCE POPS FOR THE WESTERN MIDLANDS OVERNIGHT WITH DRY CONDITIONS
EXPECTED ELSEWHERE. FOG WILL ALSO DEVELOP DURING THE EARLY MORNING
HOURS WITH WIDESPREAD FOG EXPECTED BY DAYBREAK WEDNESDAY. DO NOT
EXPECT FOG TO BE DENSE ATTM...HOWEVER SOME POTENTIAL EXISTS FOR
DENSE FOG AND WILL CONTINUE TO MONITOR. OVERNIGHT LOWS WILL BE IN
THE MIDDLE 40S TO AROUND 50.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
LOW LEVEL MOISTURE WILL CONTINUE ACROSS THE FORECAST AREA
WEDNESDAY AND THURSDAY AS THE REMAINS OF THE FRONT BECOME DIFFUSE
ACROSS THE AREA. THIS WILL KEEP MOSTLY CLOUDY SKIES ACROSS THE
REGION WITH DRY AIR IN THE MID AND UPPER LEVELS. THIS COMBINATION
WILL KEEP RAIN CHANCES LIMITED TO SLIGHT CHANCE ACROSS THE WESTERN
MIDLANDS ON WEDNESDAY AND THURSDAY. WITH THE DRY AIR IN THE MID
LEVELS AND PLENTY OF LOW LEVEL MOISTURE WEDNESDAY NIGHT THE
POTENTIAL FOR WIDESPREAD FOG...POSSIBLY DENSE...IS INCREASING.
TEMPERATURES THROUGH THE SHORT TERM WILL BE IN THE MIDDLE 60S TO
AROUND 70 FOR AFTERNOON HIGHS AND OVERNIGHT LOWS IN THE MIDDLE 40S
TO AROUND 50.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MODELS CONTINUE MAKING SIGNIFICANT RUN TO RUN CHANGES WITH
DIFFERENCES BETWEEN MODELS ALSO PERSISTING. AS SUCH CONFIDENCE IN
THE LONG TERM FORECAST REMAINS LOW WITH FEW CHANGES MADE TO THE
FORECAST. MODELS AGREE THE REMAINS OF THE FRONTAL BOUNDARY WILL
REMAIN STRETCHED ACROSS THE REGION ON FRIDAY WITH DEVELOPING LOW
PRESSURE OVER NORTHEASTERN TX ORGANIZING THE BOUNDARY FRIDAY
AFTERNOON. THE SYSTEM WILL PROGRESS EASTWARD WITH INCREASING
CHANCES OF RAIN FOR SATURDAY AND SATURDAY NIGHT AND THE SYSTEM
PASSING EAST OF THE FORECAST AREA ON SUNDAY. THE UPPER LEVEL
TROUGH WILL THEN DEEPEN OVER THE EASTERN US KEEPING ACTIVE WEATHER
OVER THE AREA AND RAIN CHANCES AGAIN NEXT MONDAY. TEMPERATURES
THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS DURING THE DAYLIGHT HOURS EXPECTED TO DETERIORATE
THIS EVENING AS WEDGE CONDITIONS DEVELOP.
CEILINGS AROUND 3500 FT THIS AFTERNOON. GUIDANCE SUGGESTING
CEILINGS WILL LOWER THIS EVENING AND LIKELY BECOME MVFR OR IFR FOR
TONIGHT.
EXTENDED AVIATION OUTLOOK...MVFR/IFR CEILINGS POSSIBLE AT TIMES
THROUGH SATURDAY AS A SERIES OF FRONTS STALL NEAR OUR REGION OR
BACK DOOR THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ030.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
711 AM EST TUE DEC 2 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL PERSIST OVER THE AREA TODAY. A COLD FRONT
WILL DROP SOUTH INTO THE AREA ON THURSDAY AND LINGER THROUGH FRIDAY
BEFORE ANOTHER COLD FRONT SWEEPS THROUGH FROM THE WEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BACKDOOR COLD FRONT ACROSS SOUTHEASTERN NORTH CAROLINA AROUND
DAYBREAK WILL TEND TO HANGUP ACROSS NC/SC STATE LINE LATER THIS
MORNING AND ESPECIALLY AFTER THE SURFACE-BASED INVERSION BREAKS
AFTER MID MORNING. MODEL FORECAST SOUNDINGS STILL INDICATE VERY
WARM LAYERS ATOP THIS INVERSION AND A CLEAN BACKDOOR FROPA IS
UNLIKELY TODAY ACROSS SE AND CENTRAL COASTAL SOUTH CAROLINA.
CLOUDS...TEMPS...AND EVEN SPOTTY CHANCES FOR SHOWERS TODAY THE
MAIN FORECAST QUESTS.
ACROSS SE SOUTH CAROLINA...ISENTROPIC LIFT ALONG A SHALLOW SURFACE
ONGOING ALONG OUR SOUTH CAROLINA ZONES EARLY IS EXPECTED TO NOSE
INTO NE SOUTH CAROLINA LEAVING SOME POTENTIAL FOR BREAKS IN THE
CLOUDS AT TIMES FROM CHARLESTON TO BEAUFORT BY THIS AFTERNOON. CLOUD
PATTERN EVOLUTION LATER THIS MORNING WILL FORETELL HIGHS THAT COULD
STRUGGLE TO REACH 70 OR POSSIBLY EVEN REACH THE MID-UPPER 70S. WE
RAISED TEMPS AT CHARLESTON TOWARD THE MID 70S. SCATTERED SHOWERS
OVER THE ADJACENT WATERS DISSIPATING MOVING TOWARD THE BEACHES AND
BARRIER ISLANDS...A FEW LIGHT SHOWERS AND SPRINKLES MAY REACH THE
COAST THROUGH MID/LATE MORNING.
ACROSS SE GEORGIA THERE IS A GREATER POTENTIAL FOR LONGER PERIODS
OF SUNSHINE AND WE HAVE MAINTAINED A SOLID MID 70S PATTERN. QUITE
A FEW OF THE HIGH RESOLUTION MODELS INCLUDING THE 06Z RAP AND H3R
INDICATE WEAK INSTABILITY COULD DEVELOP ACROSS SE GEORGIA THIS
AFTERNOON WITH EVEN SMALL SBCAPES. WHILE K INDICES WERE PROGGED IN
THE MID TEENS AND DEEPER MOISTURE LIMITED...THERE WAS ENOUGH
EVIDENCE IN THE HIGH RESOLUTION QPF/REFLECTIVITY OUTPUT TO PAINT
SOME POPS BETWEEN 15-20 PERCENT ALONG THE CONVERGENCE CORRIDOR AS
SPOTTY SHOWERS APPEAR TO BE A POSSIBILITY...AT LEAST BRIEFLY THIS
AFTERNOON.
TONIGHT...THERE ARE STRONG INDICATIONS FOR FOG AND STRATUS IF CLOUDS
SCATTER OUT OR REMAIN SCATTERED THIS EVENING. VARIOUS VSBY AND CIG
PROGS SUGGEST A POTENTIAL FOR AREAS OF DENSE FOG BUT THE MESOSCALE
WILL ONCE AGAIN DICTATE AS SOIL TEMPS HAVE BEEN WARMING THE PAST
FEW DAYS. IN EITHER CASE...INCREASING SUBSIDENCE ABOVE THE WEDGE
INVERSION IS A STRONG INDICATOR FOR STRATUS BUILD-DOWN TRENDS. WE
MAINTAINED AREAS OF FOG ALL INLAND LOCALES AND PATCHY FOG ALONG
THE COAST...LOWS IN THE 50S ALL AREAS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
THE WEAK HIGH PRESSURE WEDGE WILL QUICKLY ERODE WEDNESDAY MORNING AS
THE PARENT HIGH GETS WHISKED AWAY TO THE EAST. THE MORNING FOG AND
STRATUS WILL BE SLOW TO BURN OFF...BUT ONCE THAT OCCURS A FAIRLY
NICE DAY IS IN STORE WITH PARTLY TO MOSTLY SUNNY SKIES AND HIGHS IN
THE LOW/MID 70S.
THURSDAY INTO FRIDAY AN EXPANSIVE CANADIAN HIGH WILL BUILD OVER THE
NORTHEAST UNITED STATES AND WEDGE DOWN THE EASTERN SEABOARD.
TEMPERATURES ON THURSDAY ARE TRICKY BECAUSE THE COLDER AIR MAY NOT
OOZE INTO THE REGION UNTIL LATE IN THE DAY. ADDITIONALLY...PARTLY
SUNNY SKIES ARE POSSIBLE IN THE MORNING BEFORE MOISTURE INCREASES
AND CLOUDS THICKEN. WE ARE SHOWING FAIRLY WARM TEMPS YET AGAIN WITH
HIGHS IN THE LOWER 70S.
MODELS ARE IN GOOD AGREEMENT THAT THE WEDGE FRONT WILL DROP SOUTH OF
THE AREA BY FRIDAY MORNING WITH COOL NORTHEAST FLOW DEVELOPING.
ABUNDANT CLOUDS WILL BE IN PLACE AS A WEAK COASTAL TROUGH DEVELOPS
AND SOME SHOWERS DEVELOP OVER THE MARINE AREA. THE COLD ADVECTION
AND EXTENSIVE CLOUDINESS WILL KEEP HIGHS IN THE LOW/MID 60S NORTH
WITH UPPER 60S SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE LATE WEEK WEDGE OF HIGH PRESSURE WILL ERODE ON SATURDAY BEFORE
ANOTHER LARGE HIGH SHIFTS OUT OF CENTRAL CANADA TOWARD THE NORTHEAST
STATES LATE IN THE WEEKEND. THERE ARE SIGNIFICANT MODEL DIFFERENCES
SATURDAY AFTERNOON INTO SATURDAY NIGHT AS A SHORTWAVE SHIFTS THROUGH
THE CENTRAL PLAINS AND PRODUCES A SURFACE LOW IN THE MISSISSIPPI
VALLEY. THE ECMWF IS MUCH STRONGER WITH THE LOW AND BRINGS IT
STRAIGHT THROUGH THE AREA WHILE THE GFS LIFTS IT NORTHEAST. WE
INTRODUCED SLIGHT CHANCE POPS SATURDAY AFTERNOON AND NIGHT. ANOTHER
DISTURBANCE LOOKS TO BRUSH THE AREA ON MONDAY SO WE ADDED SLIGHT
CHANCE POPS FOR NORTHERN AREAS. SUBSTANTIAL CLOUD COVER AND SURGES
OF COLD ADVECTION WILL KEEP TEMPS BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
CLOUD COVER OVERNIGHT AND EARLY THIS MORNING HELP PUT A LID ON FOG
FORMATION AND BOTH KSAV AND KCHS SHOULD BE VFR TODAY THROUGH MOST
OF THIS EVENING. MID LEVEL SUBSIDENCE...A STRENGTHENING WEDGE
INVERSION AND COPIOUS LOW LEVEL MOISTURE SUGGEST TONIGHT WILL
EVENTUALLY BE A DIFFERENT STORY AT THE TERMINALS AS IFR CIGS AND
PERHAPS IFR VSBYS DEVELOP DURING THE END OF THE 12Z TAF CYCLE. WE
HAVE A SOLID TREND IN THAT DIRECTION WITH VERY LOW END MVFR CIGS
FOR NOW.
EXTENDED AVIATION OUTLOOK...CEILING AND/OR VISIBILITY RESTRICTIONS
POSSIBLE EACH MORNING.
&&
.MARINE...
WE MAINTAINED A PERSISTENCE FORECAST WITH A FAIRLY WEAK PRES GRADIENT
TO PERSIST INTO TONIGHT INDICATIVE OF SYNOPTIC FLOW BELOW 15 KT ACROSS
ALL WATERS. SINCE A WEAK COASTAL TROUGH HAD DEVELOPED...ENOUGH
THERMAL/MOISTURE GRADIENTS WILL EXIST TO BUMP SPEED INTO TO 10-15
KT RANGE DURING THE AFTERNOON AND EVENING HOURS. THERE HAS BEEN AN
INCREASING SE SWELL COMPONENT SHOWING UP AT THE PLATFORMS OFFSHORE
AND EXPECT SEAS SEAWARD FROM GRAYS REEF AND BUOY TANGO TO BUILD TO
4-5 FT LATER TODAY AND TONIGHT...IN LINE WITH THE LATEST WAVE-
WATCH AND SWAN MODEL OUTPUT.
A FAIRLY WEAK ALBEIT PROLONGED NORTHEAST FETCH WILL EXIST WEDNESDAY
AND THURSDAY BEFORE STRENGTHENING THURSDAY NIGHT AND FRIDAY IN THE
WAKE OF A BACKDOOR COLD FRONT. THE GRADIENT WEAKENS ON SATURDAY AS
THE HIGH BUILDS SOUTH AND WEAKENS SOMEWHAT...THOUGH INCREASING WINDS
ARE POSSIBLE LATE SUNDAY BEHIND ANOTHER COLD FRONT. BASED ON THE
WEAKER WINDS WITH THE LATEST FORECAST...SEAS MAY STAY JUST BELOW 6
FT MUCH OF THE PERIOD. HOWEVER A BRIEF WINDOW OF SOME 6 FOOTERS IS
POSSIBLE FRIDAY INTO SATURDAY OVER OFFSHORE PORTIONS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE...JRL
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
421 AM EST TUE DEC 2 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL PERSIST OVER THE AREA TODAY. A COLD FRONT
WILL DROP SOUTH INTO THE AREA ON THURSDAY AND LINGER THROUGH FRIDAY
BEFORE ANOTHER COLD FRONT SWEEPS THROUGH FROM THE WEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...A COASTAL TROUGH WAS DEVELOPING EARLY THIS MORNING. SINCE
MIDNIGHT THERE HAS BEEN EXTENSIVE COVERAGE OF STRATOCU ACROSS SE
SOUTH CAROLINA WITH SCATTERED AREAS OF STRATOCU ACROSS SE GEORGIA.
SURFACE DEW POINTS HAVE INCREASED TO THE LOWER TO MID 50S ACROSS
THE REGION AND AREAS THAT MANAGE TO REMAIN TOTALLY CLEAR STILL
HAVE A RISK FOR SOME FOG AND STRATUS FORMATION. AT THE CURRENT
TIME...THE REGION WITH BETTER CHANCES FOR FOG APPEARS TO BE TO THE
SOUTH OF I-16 IN GEORGIA BUT EVEN THERE...CLOUDS REMAIN A QUESTION
MARK. WE HAVE PATCHY TO AREAS OF FOG IN THE FORECAST TO START THE
DAY BUT NOT MUCH EXPECTATION FOR WIDESPREAD FOG THIS MORNING. A
FEW SHOWERS HAD DEVELOPED OFFSHORE BUT UNLIKELY TO MOVE ONSHORE
PER COASTAL PROXIMITY SOUNDINGS.
A BACKDOOR COLD FRONT ACROSS EASTERN NORTH CAROLINA AROUND DAYBREAK
WILL TEND TO HANGUP ACROSS NC/SC STATE LINE LATER THIS MORNING AND
ESPECIALLY AFTER THE SURFACE-BASED INVERSION BREAKS AFTER MID
MORNING. MODEL FORECAST SOUNDINGS STILL INDICATE VERY WARM LAYERS
ATOP THIS INVERSION AND A CLEAN BACKDOOR FROPA IS UNLIKELY TODAY
ACROSS SE AND CENTRAL COASTAL SOUTH CAROLINA. CLOUDS...TEMPS...AND
EVEN SPOTTY CHANCES FOR SHOWERS TODAY THE MAIN FORECAST QUESTS.
ACROSS SE SOUTH CAROLINA...ISENTROPIC LIFT ALONG A SHALLOW SURFACE
ONGOING ALONG OUR SOUTH CAROLINA ZONES EARLY IS EXPECTED TO NOSE
INTO NE SOUTH CAROLINA LEAVING SOME POTENTIAL FOR BREAKS IN THE
CLOUDS AT TIMES FROM CHARLESTON TO BEAUFORT BY THIS AFTERNOON. CLOUD
PATTERN EVOLUTION LATER THIS MORNING WILL FORETELL HIGHS THAT COULD
STRUGGLE TO REACH 70 OR POSSIBLY EVEN REACH THE MID-UPPER 70S. WE
TOOK THE MIDDLE ROAD WITH LOWER 70S AT CHARLESTON. ISOLATED SHOWERS
COULD DEVELOP TODAY IN SE SOUTH CAROLINA BUT WE MAINTAINED SILENT
POPS FOR NOW.
ACROSS SE GEORGIA THERE IS A GREATER POTENTIAL FOR LONGER PERIODS
OF SUNSHINE AND WE HAVE MAINTAINED A SOLID MID 70S PATTERN. QUITE
A FEW OF THE HIGH RESOLUTION MODELS INCLUDING THE 06Z RAP AND H3R
INDICATE WEAK INSTABILITY COULD DEVELOP ACROSS SE GEORGIA THIS
AFTERNOON WITH EVEN SMALL SBCAPES. WHILE K INDICES WERE PROGGED IN
THE MID TEENS AND DEEPER MOISTURE LIMITED...THERE WAS ENOUGH
EVIDENCE IN THE HIGH RESOLUTION QPF/REFLECTIVITY OUTPUT TO PAINT
SOME POPS BETWEEN 15-20 PERCENT ALONG THE CONVERGENCE CORRIDOR AS
SPOTTY SHOWERS APPEAR TO BE A POSSIBILITY...AT LEAST BRIEFLY THIS
AFTERNOON.
TONIGHT...THERE ARE STRONG INDICATIONS FOR FOG AND STRATUS IF CLOUDS
SCATTER OUT OR REMAIN SCATTERED THIS EVENING. VARIOUS VSBY AND CIG
PROGS SUGGEST A POTENTIAL FOR AREAS OF DENSE FOG BUT THE MESOSCALE
WILL ONCE AGAIN DICTATE AS SOIL TEMPS HAVE BEEN WARMING THE PAST
FEW DAYS. WE MAINTAINED AREAS OF FOG ALL INLAND LOCALES AND PATCHY
FOG ALONG THE COAST...LOWS IN THE 50S ALL AREAS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
THE WEAK HIGH PRESSURE WEDGE WILL QUICKLY ERODE WEDNESDAY MORNING AS
THE PARENT HIGH GETS WHISKED AWAY TO THE EAST. THE MORNING FOG AND
STRATUS WILL BE SLOW TO BURN OFF...BUT ONCE THAT OCCURS A FAIRLY
NICE DAY IS IN STORE WITH PARTLY TO MOSTLY SUNNY SKIES AND HIGHS IN
THE LOW/MID 70S.
THURSDAY INTO FRIDAY AN EXPANSIVE CANADIAN HIGH WILL BUILD OVER THE
NORTHEAST UNITED STATES AND WEDGE DOWN THE EASTERN SEABOARD.
TEMPERATURES ON THURSDAY ARE TRICKY BECAUSE THE COLDER AIR MAY NOT
OOZE INTO THE REGION UNTIL LATE IN THE DAY. ADDITIONALLY...PARTLY
SUNNY SKIES ARE POSSIBLE IN THE MORNING BEFORE MOISTURE INCREASES
AND CLOUDS THICKEN. WE ARE SHOWING FAIRLY WARM TEMPS YET AGAIN WITH
HIGHS IN THE LOWER 70S.
MODELS ARE IN GOOD AGREEMENT THAT THE WEDGE FRONT WILL DROP SOUTH OF
THE AREA BY FRIDAY MORNING WITH COOL NORTHEAST FLOW DEVELOPING.
ABUNDANT CLOUDS WILL BE IN PLACE AS A WEAK COASTAL TROUGH DEVELOPS
AND SOME SHOWERS DEVELOP OVER THE MARINE AREA. THE COLD ADVECTION
AND EXTENSIVE CLOUDINESS WILL KEEP HIGHS IN THE LOW/MID 60S NORTH
WITH UPPER 60S SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE LATE WEEK WEDGE OF HIGH PRESSURE WILL ERODE ON SATURDAY BEFORE
ANOTHER LARGE HIGH SHIFTS OUT OF CENTRAL CANADA TOWARD THE NORTHEAST
STATES LATE IN THE WEEKEND. THERE ARE SIGNIFICANT MODEL DIFFERENCES
SATURDAY AFTERNOON INTO SATURDAY NIGHT AS A SHORTWAVE SHIFTS THROUGH
THE CENTRAL PLAINS AND PRODUCES A SURFACE LOW IN THE MISSISSIPPI
VALLEY. THE ECMWF IS MUCH STRONGER WITH THE LOW AND BRINGS IT
STRAIGHT THROUGH THE AREA WHILE THE GFS LIFTS IT NORTHEAST. WE
INTRODUCED SLIGHT CHANCE POPS SATURDAY AFTERNOON AND NIGHT. ANOTHER
DISTURBANCE LOOKS TO BRUSH THE AREA ON MONDAY SO WE ADDED SLIGHT
CHANCE POPS FOR NORTHERN AREAS. SUBSTANTIAL CLOUD COVER AND SURGES
OF COLD ADVECTION WILL KEEP TEMPS BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
KCHS...LATEST SATELLITE TRENDS SUGGEST STRATOCUMULUS CLOUDS
EXPANDING AT 5-6 KFT AND FOG POTENTIAL LOOKS DIMINISHED. UNTIL
TRENDS DICTATE WE HAVE RAN WITH VFR OVERNIGHT. VFR INTO THIS
EVENING WITH SOME LOWER CLOUDS STARTING TO INCREASE NEAR THE
END OF THE 06Z CYCLE.
KSAV...SCATTERED CLOUDS AROUND WERE DIMINISHING THE POTENTIAL
FOR FOG FORMATION BUT WE RETAINED MVFR CONDITIONS IN A TEMPO
LATER TONIGHT AS OTHER CONDITIONS REMAINED QUITE FAVORABLE.
AFTER MID MORNING...VFR INTO THIS EVENING.
EXTENDED AVIATION OUTLOOK...CEILING AND/OR VISIBILITY RESTRICTIONS
POSSIBLE EACH MORNING.
&&
.MARINE...
WE MAINTAINED A PERSISTENCE FORECAST WITH A FAIRLY WEAK PRES GRADIENT
TO PERSIST INTO TONIGHT INDICATIVE OF SYNOPTIC FLOW BELOW 15 KT ACROSS
ALL WATERS. SINCE A WEAK COASTAL TROUGH HAD DEVELOPED...ENOUGH
THERMAL/MOISTURE GRADIENTS WILL EXIST TO BUMP SPEED INTO TO 10-15
KT RANGE DURING THE AFTERNOON AND EVENING HOURS. THERE HAS BEEN AN
INCREASING SE SWELL COMPONENT SHOWING UP AT THE PLATFORMS OFFSHORE
AND EXPECT SEAS SEAWARD FROM GRAYS REEF AND BUOY TANGO TO BUILD TO
4-5 FT LATER TODAY AND TONIGHT...IN LINE WITH THE LATEST WAVE-
WATCH AND SWAN MODEL OUTPUT.
A FAIRLY WEAK ALBEIT PROLONGED NORTHEAST FETCH WILL EXIST WEDNESDAY
AND THURSDAY BEFORE STRENGTHENING THURSDAY NIGHT AND FRIDAY IN THE
WAKE OF A BACKDOOR COLD FRONT. THE GRADIENT WEAKENS ON SATURDAY AS
THE HIGH BUILDS SOUTH AND WEAKENS SOMEWHAT...THOUGH INCREASING WINDS
ARE POSSIBLE LATE SUNDAY BEHIND ANOTHER COLD FRONT. BASED ON THE
WEAKER WINDS WITH THE LATEST FORECAST...SEAS MAY STAY JUST BELOW 6
FT MUCH OF THE PERIOD. HOWEVER A BRIEF WINDOW OF SOME 6 FOOTERS IS
POSSIBLE FRIDAY INTO SATURDAY OVER OFFSHORE PORTIONS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE...JRL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
413 PM CST TUE DEC 2 2014
.SHORT TERM...
256 PM CST
TONIGHT THROUGH FRIDAY...
THE THEME OF THE FORECAST IS CONTINUED SEASONABLY COOL AND
DRY...WITH PERIODS OF NEAR TO...FOR DECEMBER...SLIGHTLY ABOVE NORMAL
TEMPERATURES OVER THE WEEKEND. THE LARGE SCALE WEATHER PATTERN IS
CHARACTERIZED BY AN UPPER TROUGH OVER NORTH CENTRAL CANADA WITH
QUASI-ZONAL FLOW DRAPED ACROSS EAST CENTRAL USA. OUR NECK OF THE
WOODS IS ON THE SOUTHERN END OF THE TROUGH AXIS...WITH SOME
SHORTWAVE ENERGY RIDING THROUGH THE BASE OF THE TROUGH INTO MN/WI. A
FEW ADDITIONAL TROUGHS LIE OFF THE CALIFORNIA COAST AND OFF THE TIP
OF ALASKA. AT THE SURFACE...STRONG HIGH PRESSURE IS IN NEW ENGLAND
WHILE WEAKER HIGH PRESSURE EXTENDS OVER OUR AREA SW TO THE MID
MISSOURI VALLEY...WITH WEAK LOW PRESSURE SLIDING SOUTHEAST INTO
NORTHERN MINNESOTA.
STRATUS IS SURGING NORTHWARD AS PRESSURE LOWERS TO THE
NORTH...THOUGH THERE IS A BACK EDGE APPROACHING THE MISSISSIPPI
RIVER ON THE LEADING EDGE OF DRIER AIR IN THE PLAINS. THE ENERGY
AT THE BASE OF THE CANADIAN TROUGH WILL CONTINUE TO SLIDE EAST
TODAY. THE MOISTURE STARVED SYSTEM...PW`S UNDER 0.3 IN...WILL
CONTINUE TO RESULT IN HIGH CLOUDS AND VERY LIGHT SNOW TO OUR
NORTH. THE WEAK SURFACE LOW IN NORTHERN MINNESOTA WILL SLIDE TO
LAKE SUPERIOR TONIGHT. AS THIS OCCURS A COLD FRONT WILL APPROACH
FROM THE NW...BUT CONVERGENCE ON THE FRONT IS WEAK...SO NOT
EXPECTING MUCH OUT OF THIS. THE LOW LEVEL MOISTURE GETS SHUNTED
EAST QUICKLY WITH APPROACH OF DRIER AIR FROM THE NORTHWEST THIS
EVENING AND TONIGHT...THOUGH SOME MID AND HIGHER CLOUDS WILL DRIFT
THROUGH OVERNIGHT WITH THE TROUGH.
THE SURFACE LOW WILL DEEPEN QUITE A BIT MORE NEAR JAMES BAY ON
WEDNESDAY...BUT BY THIS TIME THE SHORTWAVE ENERGY WILL BE EAST OF
OUR AREA. WE GET A BRIEF REINFORCING SHOT OF SLIGHTLY COLDER
AIR...SHOULD SEE A BIT MORE SUNSHINE AFTER ANY LINGERING LOWER LEVEL
MOISTURE IN THE SOUTHEAST ERODES. SURFACE HIGH BUILDS IN LATE IN THE
DAY AND OVERNIGHT...RESULTING IN A CRISP AND DRY NIGHT WEDNESDAY
NIGHT.
THE SURFACE HIGH RETREATS SLOWLY ON THURSDAY AS THE FLOW ALOFT TURNS
ZONAL AGAIN. THE TROUGH OFF THE CALIFORNIA COAST DISSOLVES...BUT
SOME WEAK ENERGY ASSOCIATED WITH IT RAPIDLY MOVES EASTWARD.
MOISTURE TRANSPORT INCREASES IN THE SOUTHWEST FLOW AHEAD OF THIS
DISTURBANCE. ISENTROPIC LIFT REALLY DOES NOT GET GOING INTO THURSDAY
NIGHT AND MORE SO FRIDAY...SO REMOVED SLIGHT CHANCE MENTION FOR
THURSDAY. LOOKS LIKE BEST ISENTROPIC LIFT COINCIDES WITH MOISTURE TO
OUR SOUTH...AND THE ECMWF CONTINUES A CONSISTENT TREND OF PRECIP
REMAINING SOUTH OF I-80. KEPT SOME SMALL POPS NORTH WITH THE GFS
HOLDING ONTO SOME PRECIP...BUT FEEL THAT MUCH OF THIS WILL SLIDE BY
TO THE SOUTH AS WE HANG ONTO A DRIER NE FLOW.
KMD
&&
.LONG TERM...
256 PM CST
SATURDAY THROUGH TUESDAY...
IT APPEARS TO BE A BENIGN AND MILDER PATTERN FOR THE WEEKEND. QUIET
WESTERLY FLOW ALOFT AND SURFACE HIGH PRESSURE IN CONTROL. NORTHEAST
FLOW WILL KEEP THINGS A BIT COOLER...THEN HIGH PRESSURE SHIFTS
SOMEWHAT EAST SUNDAY. HIGH PRESSURE ALOFT OFF IN THE ATLANTIC KEEPS
THE CANADIAN TROUGH AT BAY...AND THEREFORE ALLOWS SHORTWAVE ENERGY
CURRENTLY OFF THE ALASKA COAST TO PUSH SOUTHWEST OUT OF THE CANADIAN
ROCKIES IN A CLIPPER-LIKE MANNER SUNDAY NIGHT INTO MONDAY. MODELS
ARE MIXED AS TO WHETHER WE GET ANY PRECIP WITH THIS WITH THE
"WETTER" GFS JUST GRAZING THE AREA WITH SOME LIGHT RAIN TURNING TO
POSSIBLY SNOW...WHILE THE EC IS DRY WITH THE ENERGY HEADING NORTH.
THE PATTERN LOOKS TO AMPLIFY SOME BY EARLY TO MID NEXT WEEK...BUT
NOT UNTIL AFTER A PERIOD OF DRY AND COOLER NORTHERLY FLOW TO START
THE WEEK. EVENTUALLY THIS WILL ALLOW A RIDGE IN THE WEST TO MAKE
SOME HEADWAY EASTWARD BUT THIS APPEARS TO HAVE SLOWED A LITTLE BIT.
MODELS HAVE MODERATE PREDICTABILITY ON THIS FEATURE AT THIS TIME
WHICH WOULD BRING DRY AND MILDER WEATHER.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* MVFR CIGS THIS AFTN AND EVENING.
KREIN
//DISCUSSION...UPDATED 22Z...
THE MVFR STRATOCU DECK IS HAVING A HARD TIME REACHING ORD/DPA WITH
THE LATEST SATELLITE IMAGERY SHOWING SOME EROSION ON THE LEADING
EDGE OF THE CLOUD DECK. ALSO...LATEST SFC OBS UPSTREAM INDICATING
A MORE LAYERED CLOUD PROFILE WITH SCT018 UNDER AN OVC LOW END VFR
DECK. SO...HAVE BACKED OFF A LITTLE ON CLOUD COVER AT ORD/DPA TO A
TEMPO MVFR. MDW/RFD/GYY SHOULD REMAIN PREVAILING MVFR AS PER THE
GOING FORECAST...THOUGH TIMING OF IMPROVEMENT IS A LITTLE LESS
CERTAIN...BUT WILL MAINTAIN THE 06Z TIMING FOR IMPROVEMENT TO
PREVAILING VFR AT ALL SITES...WITH CONTINUED SW WINDS ARND 10 KT.
STILL ANTICIPATE CLEARING SKIES FOR WEDNESDAY AS HIGH PRESSURE
MOVES ACROSS THE AREA WITH WEST WINDS ARND 10 KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE IN CIGS AT ORD.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. WEST WINDS.
THURSDAY...VFR. EAST WINDS.
FRIDAY...CHANCE FOR MVFR. EAST WINDS.
SATURDAY...CHANCE FOR MVFR. NORTHEAST WINDS.
SUNDAY...CHANCE FOR RAIN/SNOW AND IFR. SOUTHEAST WINDS.
MONDAY...CHANCE FOR RAIN/SNOW AND IFR CONDS EARLY. SOUTH/SOUTHWEST
WINDS.
BEACHLER
&&
.MARINE...
123 PM CST
HIGH PRESSURE TO THE EAST OF THE LAKE AND A TROUGH OF LOW PRESSURE
APPROACHING FROM THE WEST HAS ALLOWED FOR SOUTHERLY WINDS
TODAY...WITH HIGHEST SPEEDS TO 30 KT BEING OBSERVED OVER THE
NORTHERN HALF OF THE LAKE. THESE SAME SPEEDS WILL LIKELY CONTINUE
TONIGHT BUT WITH WINDS BECOMING MORE WESTERLY AS THIS TROUGH AND
FRONTAL BOUNDARY MOVE ACROSS THE LAKE THROUGH WEDNESDAY MORNING.
SPEEDS WILL BRIEFLY COME DOWN WEDNESDAY MORNING WITH THE DEPARTURE
OF THIS TROUGH...BUT WILL INCREASE IN THE AFTERNOON AS HIGH
PRESSURE BUILDS SOUTHEAST ACROSS THE REGION. EXPECT ANOTHER PERIOD
OF TO 30 KT WINDS OVER THE ENTIRE LAKE WEDNESDAY AFTERNOON INTO
THE NIGHT...BEFORE WINDS DIMINISH INTO THURSDAY MORNING AS THIS
HIGH MOVES OVERHEAD. THIS HIGH WILL SHIFT TO THE EAST THURSDAY
INTO THURSDAY NIGHT...WITH A PERIOD OF SOUTHERLY FLOW EXPECTED
THROUGH THE END OF THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ745...10 PM TUESDAY TO 4 AM THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
310 PM CST Tue Dec 2 2014
.SHORT TERM...(Tonight)
ISSUED AT 310 PM CST TUE DEC 2 2014
20z/2pm surface analysis shows ridge axis extending from the Great
Lakes to Texas. Despite presence of high pressure, low-level
moisture remains trapped beneath a strong subsidence inversion
evident on latest LAPS soundings, which has resulted in overcast
conditions across central Illinois this afternoon. Visible
satellite imagery shows back edge of clouds slowly eroding across
central Missouri, with satellite timing tools bringing the clearing
into the western KILX CWA by mid-evening. Latest HRRR has a similar
trend, suggesting clearing skies from west to east by mid to late
evening. Based on satellite trends and expected southwesterly
return flow on the back side of the departing high, think skies will
become mostly clear across locations along/northwest of a
Taylorville to Champaign line by midnight. Further southeast, cloud
cover will be much slower to exit, with soundings indicating mostly
cloudy skies through the entire night across the far E/SE CWA. Due
to the initial cloud cover and a light southwesterly wind, have gone
2 to 3 degrees above MAV guidance for lows tonight, with readings
ranging from the lower 20s far northwest around Galesburg to the
lower 30s far southeast.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 310 PM CST TUE DEC 2 2014
Morning upper air and moisture channel satellite data shows minor
upper wave moving east across the northern US, approaching Great
Lakes. This system will drag a weak cold front into IL region on
early on Wednesday, coming through dry and bringing high pressure in
behind it.
Main system to affect area is currently off the west coast. Forecast
models bring a wave east from the offshore low, it tracking east
over the western state through day Thursday. southerly low level
flow expected to develop Thursday in response to the system exiting
the Rockies. Overrunning flow will develop precipitation by late
Thursday, but will not reach region till Thursday night, so dropped
Thursday pcpn. Pops spreading into the CWA Thursday night. With
temperature though near freezing, possibly some freezing rain in the
central and north central parts of IL Thursday night, before
temperatures rise Friday morning with the bulk of pcpn on Friday and
Friday night.
Track of the developing surface low is still a little uncertain, as
GFS brings low across KY and EUR across northern AL. Pcpn to
gradually pull out on Saturday, and will be faster if EUR solution
is right.
Weak northern stream system to again move over Great Lakes on
Monday, but have kept forecast dry at this time, again due to the
differences in the models on track and moisture.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1154 AM CST TUE DEC 2 2014
Large area of low cloudiness remains trapped beneath a strong
subsidence inversion late this morning. Ceilings are currently
high IFR/low MVFR, but should improve into the MVFR category
across the board within the next hour or two.
Main aviation concerns will be ceiling heights initially, then
timing of clearing later this evening. Based on latest obs, have
started out with IFR ceilings at all terminals except KPIA. Given
upstream trends, have raised ceilings to MVFR at the remaining TAF
sites between 19z and 20z. Latest HRRR shows clearing line
currently over northwest Missouri advancing steadily eastward this
afternoon, reaching the Illinois River Valley by around 00z.
Meanwhile, satellite timing tools are slightly slower, indicating
clearing may not reach the far western KILX CWA until around 02z.
Will therefore maintain the previous forecast, with clearing
arriving at KPIA by 03z, then further east to KCMI by 06z. After
that, clear skies and light southwesterly winds are anticipated
through Wednesday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Goetsch
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
124 PM CST TUE DEC 2 2014
.SHORT TERM...
200 AM CST
THROUGH WEDNESDAY...
HIGH PRESSURE WILL MOVE EAST OF THE REGION TODAY ALLOWING FOR
SOUTHERLY WINDS TO DEVELOP AND WARM AIR ADVECTION TO COMMENCE.
SUNSHINE THIS MORNING SHOULD GIVE WAY TO INCREASINGLY CLOUDINESS
THIS AFTERNOON WHICH ALONG WITH THE COLD START SHOULD KEEP TEMPS
FROM GETTING TOO TERRIBLY MILD...THOUGH STILL WARMER THAN MONDAY.
CLOUD COVER AND SOUTHWEST WINDS STAYING UP TONIGHT AHEAD OF AN
APPROACHING COLD FRONT SHOULD KEEP TEMPS FROM FALLING OFF TOO MUCH
TONIGHT. WEAK COLD FRONT WILL MOVE THROUGH WEDNESDAY MORNING AND
KNOCK A COUPLE DEGREES OF TEMPS...BUT THAT WILL BE SOMEWHAT
CANCELLED OUT BY FAR MORE SUNSHINE WEDNESDAY.
IZZI
&&
.LONG TERM...
200 AM CST
WEDNESDAY NIGHT ONWARD...
SEASONABLY COOL CONDITIONS WILL PREVAIL THE REMAINDER OF THE WEEK
WITH GENERALLY EASTERLY WINDS DEVELOPING AFTER HIGH PRESSURE
SCOOTS OFF TO THE EAST THURSDAY. THE SHORTWAVE TROUGH WE`VE BEEN
WATCHING IN THE MEDIUM RANGE MODELS FOR DAYS NOW LOOKS TO BE MORE
OF A LATE THURS NIGHT OR FRIDAY SYSTEM NOW AND STILL GENERALLY
SOUTH OF OUR CWA. HAVE MAINTAINED THE MODEL BLENDED SLIGHT CHANCE
POPS SOUTH OF THE KANKAKEE RIVER...BUT STILL LOOKS LIKE A LIGHT IF
ANY TYPE PRECIP EVENT. WEEKEND STILL LOOKING DRY WITH NEAR-TO
ABOVE AVERAGE TEMPS WITH THE PARALLEL GFS THE MOST BULLISH IN
WARMING TEMPS INTO THE MID-UPPER 40S SAT THROUGH TUESDAY WHILE THE
ECMWF DROPS A COLD FRONT ACROSS AREA MONDAY COOLING TEMPS OFF.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS THIS AFTN AND EVENING.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE IS OVER QUEBEC ALLOWING WINDS TO BECOME SW ARND 10
KT. MAY SEE A FEW OCNL GUSTS BUT EXPECTING THEM TO SUBSIDE AS THE
MVFR CIGS PUSH NORTH. THE MVFR CIGS ARE STEADILY MOVING NORTH SO
HAVE MUCH HIGHER CONFIDENCE IN TIMING. CIGS ARE FALLING TO LOW END
MVFR TO IFR DOWNSTATE BUT THINKING THE LOWER STUFF WILL STAY SOUTH
OF THE TERMINALS. THE MOISTURE AND MVFR CLOUDS SHOULD PUSH EAST
AROUND 06Z LEADING TO VFR CONDITIONS AND CONTINUED SW WINDS ARND
10 KT. SKIES CLEAR WEDNESDAY MORNING WITH WEST WINDS ARND 10 KT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. WEST WINDS.
THURSDAY...VFR. EAST WINDS.
FRIDAY...CHANCE FOR MVFR. EAST WINDS.
SATURDAY...CHANCE FOR MVFR. NORTHEAST WINDS.
SUNDAY...CHANCE FOR RAIN/SNOW AND IFR. SOUTHEAST WINDS.
MONDAY...CHANCE FOR RAIN/SNOW AND IFR CONDS EARLY. SOUTH/SOUTHWEST
WINDS.
BEACHLER
&&
.MARINE...
123 PM CST
HIGH PRESSURE TO THE EAST OF THE LAKE AND A TROUGH OF LOW PRESSURE
APPROACHING FROM THE WEST HAS ALLOWED FOR SOUTHERLY WINDS
TODAY...WITH HIGHEST SPEEDS TO 30 KT BEING OBSERVED OVER THE
NORTHERN HALF OF THE LAKE. THESE SAME SPEEDS WILL LIKELY CONTINUE
TONIGHT BUT WITH WINDS BECOMING MORE WESTERLY AS THIS TROUGH AND
FRONTAL BOUNDARY MOVE ACROSS THE LAKE THROUGH WEDNESDAY MORNING.
SPEEDS WILL BRIEFLY COME DOWN WEDNESDAY MORNING WITH THE DEPARTURE
OF THIS TROUGH...BUT WILL INCREASE IN THE AFTERNOON AS HIGH
PRESSURE BUILDS SOUTHEAST ACROSS THE REGION. EXPECT ANOTHER PERIOD
OF TO 30 KT WINDS OVER THE ENTIRE LAKE WEDNESDAY AFTERNOON INTO
THE NIGHT...BEFORE WINDS DIMINISH INTO THURSDAY MORNING AS THIS
HIGH MOVES OVERHEAD. THIS HIGH WILL SHIFT TO THE EAST THURSDAY
INTO THURSDAY NIGHT...WITH A PERIOD OF SOUTHERLY FLOW EXPECTED
THROUGH THE END OF THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1154 AM CST Tue Dec 2 2014
.UPDATE...
ISSUED AT 1038 AM CST TUE DEC 2 2014
Elongated high pressure ridge stretching from southeastern Canada
back to the western Gulf Coast this morning. Weak winds across the
area picking up an increasingly southern component as the ridge
shifts eastward. Llvl moisture trapped under a strong inversion
has spread cloud cover across the area. Low clouds expected to
persist through the evening hours according to the NAM and HRRR,
and given the strength of the inversion on ILX and SGF soundings
this morning...have maintained the cloud cover through the day.
Hourly forecast doing well and no updates are anticipated at this
time.
&&
.SHORT TERM...(Today through Wednesday night)
ISSUED AT 330 AM CST TUE DEC 2 2014
Blanket of low/mid clouds over central and southern parts of IL/MO
are steadily lifting northward toward I-72 in central IL early
this morning and models show these clouds lifting across the rest
of central IL during this morning. These clouds then appear to
hang around into tonight especially over eastern IL and decrease
from west to east later tonight into Wed morning. Highs today
generally in the 30s with lower 30s nw of the IL river and
Lawrenceville approaching 40F. So trended forecast today cloudier
and a bit cooler. Strong 1043 mb arctic high pressure over
southern Quebec was ridging sw into northern IL and MO and
creating a strong inversion over region which will trap the low
clouds.
Another Canadian high pressure over the northern Rockies will
settle into the Midwest Wed afternoon and continue dry weather
over central/se IL through at least Wed night. More sunshine
expected Wed with low clouds lingering longest in southeast IL.
Lows tonight range from lower 20s over the IL river valley to near
30F se of I-70. A bit milder highs Wed with more sunshine range
from mid 30s from Peoria north to the lower 40s south of I-72.
Clouds increase later Wed night from the sw with lows around 20F
northern counties and mid to upper 20s in southeast IL.
&&
.LONG TERM...(Thursday through Tuesday)
ISSUED AT 330 AM CST TUE DEC 2 2014
00Z models continue to trend slower with arriving of over running
precipitation from frontal boundary south of IL on Thu/Fri and
Canadian high pressure drifting east across the Great Lakes region.
Have trimmed back pops to just slight chance sw areas Thu with
light freezing rain and sleet in morning and just light rain Thu
afternoon. NE areas should stay dry but cloud up too. Highs Thu in
the mid to upper 30s with Lawrenceville around 40F. Have
increasing chances of precipitation during Thu night and
especially Friday with likely chances of rain in southeast IL
Friday. Chance of light freezing rain/sleet north of I-72 Thu
night though pops are slight northern counties and qpf amounts
very light then if at all. Increase rain chances Fri night
especially in southeast IL as low pressure ejects ne from the
southern plains into mid TN by dawn Sat. Lingered slight chance of
light rain in southeast IL Sat morning then dry the rest of the
weekend. Temps modify to highs in the low to mid 40s from Fri-Mon.
Have slight chance of light precipitation early next work week
with cold front pressing se into region with northern areas
possibly getting a mix of light precipitation. Cooler temps next
Tue.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1154 AM CST TUE DEC 2 2014
Large area of low cloudiness remains trapped beneath a strong
subsidence inversion late this morning. Ceilings are currently
high IFR/low MVFR, but should improve into the MVFR category
across the board within the next hour or two.
Main aviation concerns will be ceiling heights initially, then
timing of clearing later this evening. Based on latest obs, have
started out with IFR ceilings at all terminals except KPIA. Given
upstream trends, have raised ceilings to MVFR at the remaining TAF
sites between 19z and 20z. Latest HRRR shows clearing line
currently over northwest Missouri advancing steadily eastward this
afternoon, reaching the Illinois River Valley by around 00z.
Meanwhile, satellite timing tools are slightly slower, indicating
clearing may not reach the far western KILX CWA until around 02z.
Will therefore maintain the previous forecast, with clearing
arriving at KPIA by 03z, then further east to KCMI by 06z. After
that, clear skies and light southwesterly winds are anticipated
through Wednesday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...07
LONG TERM...07
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1132 AM CST TUE DEC 2 2014
.SHORT TERM /TODAY/...
ISSUED AT 319 AM CST TUE DEC 2 2014
SURFACE RIDGE CURRENTLY RETREATING TO THE EAST WITH WARM ADVECTION
INCREASING RAPIDLY ON BACKSIDE. PRESSURE GRADIENT TIGHTENS RAPIDLY
WITH STRONG SOUTH WINDS ALREADY IN NORTHWEST IOWA. TEMPERATURES
HAVE ALSO STABILIZED AND EVEN RISEN WITH THE INCREASED MIXING AND
CLOUD COVER ACROSS NORTHERN IOWA. WILL CONTINUE TO SEE THE WARMING
THROUGH THE DAY AS THERMAL RIDGE SLIDES INTO THE STATE BY MIDDAY.
HAVE REMAINED ON THE WARM SIDE OF GUIDANCE FOR HIGHS THIS AFTERNOON
WITH STRONG MIXING AND SOME SUNSHINE ALONG WITH LIMITED SNOW COVER
WHICH SHOULD ALLOW READINGS TO CLIMB NICELY. OF CONCERN WITH
CLOUDS...THERE IS A BROAD EXPANSE OF LOWER CLOUDINESS ACROSS
MISSOURI THIS MORNING WHICH IS LIFTING NORTHWARD ON STRONG SOUTHERLY
LOW LEVEL FLOW. BOTH RAP AND HRRR INDICATE THIS AREA OF CLOUDS
SLIDING ACROSS THE SOUTHEAST THIRD OF THE FORECAST AREA THIS MORNING
INTO EARLY AFTERNOON BEFORE EXITING TO THE EAST. THEREFORE...HAVE
GONE WITH MUCH MORE CLOUD COVERAGE ACROSS THE SOUTHEAST THROUGH
EARLY AFTERNOON BEFORE THE CLOUDS PUSH EASTWARD.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 319 AM CST TUE DEC 2 2014
THE PATTERN FOR MUCH OF THE UPPER MIDWEST REMAINS BENIGN FOR THE
EXTENDED. TONIGHT A BOUNDARY WILL WORK ITS WAY ACROSS IOWA BUT
MOISTURE IS WOEFULLY LACKING. IN FACT THERE DOESN`T APPEAR TO BE
ENOUGH TO PRODUCE MUCH CLOUD COVER. THE ONLY SENSIBLE WEATHER WILL
BE A WIND SHIFT LATE TONIGHT TO THE NORTHWEST AND SLIGHTLY COOLER
TEMPS FOR WEDNESDAY AND WEDNESDAY NIGHT.
BY LATE WEDNESDAY NIGHT AND THURSDAY THE HIGH SHIFTS EAST ALLOWING
FOR A RETURN TO A LIGHT SOUTHERLY FLOW SO TEMPS WILL BEGIN TO WARM
BACK UP ON THURSDAY. MID LEVEL MOISTURE WILL BE ENOUGH FOR SOME
CLOUD COVER SO I DID NOT GO TOO WARM ON THURSDAY. THURSDAY NIGHT
AND FRIDAY SHOULD BE A LITTLE WARMER AS DEEPER SOUTHERLY FLOW
BECOMES ESTABLISHED. HOWEVER...A SHORTWAVE PUSHING ACROSS THE
SOUTHERN PLAINS WILL DRAW SOME MOISTURE NORTHWARD. AT THIS POINT IT
DOES NOT APPEAR THAT MUCH MOISTURE WILL MAKE IT INTO IOWA BUT THIS
DOES BEAR WATCHING. TEMP PROFILES ARE RATHER INTERESTING AS WELL.
SOUNDINGS SHOW NEAR SURFACE TEMPS AT OR JUST BELOW FREEZING LATE
THURSDAY EVENING TO THURSDAY NIGHT BUT WE SHOULD MIX ENOUGH TO STAY
ABOVE FREEZING WITH THE POSSIBLE EXCEPTION OF THE NORTHWEST CWA. IT
IS POSSIBLE THAT FAR SOUTHERN IOWA MAY SEE SOME PATCHY DRIZZLE WITH
THE MOISTURE MOVING UP. AT THIS POINT THE MODELS REALLY KEEP ANY OF
THIS POTENTIAL SOUTH OF IOWA ALTHOUGH IT WILL BE CLOSE. I DID PUT
SOME SLIGHT CHANCE POPS IN ACROSS THE SOUTH FOR THE SAKE OF
COLLABORATION AND THE SREF AND CANADIAN DO BRING SOMETHING INTO THE
SOUTH AND EAST...HOWEVER MY CONFIDENCE IS LOW.
THAT SYSTEM THEN MOVES OFF ON FRIDAY AND TEMPS BEHIND IT ARE JUST A
BIT COOLER FOR FRIDAY NIGHT AND SATURDAY BUT STILL AT OR ABOVE
NORMAL HIGHS FOR EARLY DECEMBER.
BY LATE IN THE EXTENDED THE MODELS DEVELOP A RATHER STRONG SHORTWAVE
ACROSS CANADA AND THE NORTHERN PLAINS THAT IMPACTS THE UPPER MIDWEST
LATE SUNDAY INTO MONDAY. THE CANADIAN AND THE EURO MODELS ARE A
LITTLE STRONGER WITH THIS SYSTEM AND THEY DIG THE SHORTWAVE INTO
IOWA BUT THERE IS ALSO A SOUTHERN STREAM SHORTWAVE DURING THIS TIME
THAT DOES NOT EXACTLY PHASE WITH THE NORTHERN ONE THUS THEY DEVELOP
TWO AREAS OF PRECIP...ONE ACROSS THE NORTHERN PLAINS AND ONE ACROSS
THE SOUTHERN PLAINS LEAVING IOWA IN BETWEEN WITH LITTLE OR NO
PRECIP. BY THE TIME THE SHORTWAVES DO PHASE THE SYSTEM IS EAST OF
IOWA. WE HAD SLIGHT CHANCE POPS GOING AND I SAW NO REASON TO PULL
THEM AT THIS POINT BUT THERE CERTAINLY DOES NOT APPEAR TO BE A
GREATER CHANCE THAN THAT GIVEN THE MODEL SOLUTIONS. ALSO...TEMPS
DURING THIS PERIOD SHOULD BE WARM ENOUGH FOR RAIN SOUTH AND A MIX
NORTH DURING THE DAY AND A MIX SOUTH TO SNOW NORTH SUNDAY NIGHT.
EARLY NEXT WEEK WILL BE A LITTLE COOLER FOLLOWING THIS SYSTEM.
&&
.AVIATION...02/18Z
ISSUED AT 1132 AM CST TUE DEC 2 2014
MVFR CIGS WILL CONTINUE IN SOUTHEAST IA THRU EARLY TO MID-
AFTN...THEN LIFT OFF TOWARDS THE E. ONLY KOTM IS EXPECTED TO BE
IMPACTED BY THE MVFR CIGS...WITH SCT CLOUDS AFFECTING THE KDSM AND
KALO TERMINALS. SFC WINDS WILL BE QUITE STRONG FROM THE SOUTH TO
SOUTHWEST TDA BUT WILL LIGHTEN QUICKLY THIS EVENING. WINDS WILL
BECOME NORTHWEST BEHIND A SFC FRONT PASSING THRU THE STATE OVERNIGHT
TONIGHT INTO WEDNESDAY MORNING BUT WILL NOT BE AS STRONG AS TODAY/S
WINDS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...COGIL
LONG TERM...FAB
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
553 AM CST TUE DEC 2 2014
.SHORT TERM /TODAY/...
ISSUED AT 319 AM CST TUE DEC 2 2014
SURFACE RIDGE CURRENTLY RETREATING TO THE EAST WITH WARM ADVECTION
INCREASING RAPIDLY ON BACKSIDE. PRESSURE GRADIENT TIGHTENS RAPIDLY
WITH STRONG SOUTH WINDS ALREADY IN NORTHWEST IOWA. TEMPERATURES
HAVE ALSO STABILIZED AND EVEN RISEN WITH THE INCREASED MIXING AND
CLOUD COVER ACROSS NORTHERN IOWA. WILL CONTINUE TO SEE THE WARMING
THROUGH THE DAY AS THERMAL RIDGE SLIDES INTO THE STATE BY MIDDAY.
HAVE REMAINED ON THE WARM SIDE OF GUIDANCE FOR HIGHS THIS AFTERNOON
WITH STRONG MIXING AND SOME SUNSHINE ALONG WITH LIMITED SNOW COVER
WHICH SHOULD ALLOW READINGS TO CLIMB NICELY. OF CONCERN WITH
CLOUDS...THERE IS A BROAD EXPANSE OF LOWER CLOUDINESS ACROSS
MISSOURI THIS MORNING WHICH IS LIFTING NORTHWARD ON STRONG SOUTHERLY
LOW LEVEL FLOW. BOTH RAP AND HRRR INDICATE THIS AREA OF CLOUDS
SLIDING ACROSS THE SOUTHEAST THIRD OF THE FORECAST AREA THIS MORNING
INTO EARLY AFTERNOON BEFORE EXITING TO THE EAST. THEREFORE...HAVE
GONE WITH MUCH MORE CLOUD COVERAGE ACROSS THE SOUTHEAST THROUGH
EARLY AFTERNOON BEFORE THE CLOUDS PUSH EASTWARD.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 319 AM CST TUE DEC 2 2014
THE PATTERN FOR MUCH OF THE UPPER MIDWEST REMAINS BENIGN FOR THE
EXTENDED. TONIGHT A BOUNDARY WILL WORK ITS WAY ACROSS IOWA BUT
MOISTURE IS WOEFULLY LACKING. IN FACT THERE DOESN`T APPEAR TO BE
ENOUGH TO PRODUCE MUCH CLOUD COVER. THE ONLY SENSIBLE WEATHER WILL
BE A WIND SHIFT LATE TONIGHT TO THE NORTHWEST AND SLIGHTLY COOLER
TEMPS FOR WEDNESDAY AND WEDNESDAY NIGHT.
BY LATE WEDNESDAY NIGHT AND THURSDAY THE HIGH SHIFTS EAST ALLOWING
FOR A RETURN TO A LIGHT SOUTHERLY FLOW SO TEMPS WILL BEGIN TO WARM
BACK UP ON THURSDAY. MID LEVEL MOISTURE WILL BE ENOUGH FOR SOME
CLOUD COVER SO I DID NOT GO TOO WARM ON THURSDAY. THURSDAY NIGHT
AND FRIDAY SHOULD BE A LITTLE WARMER AS DEEPER SOUTHERLY FLOW
BECOMES ESTABLISHED. HOWEVER...A SHORTWAVE PUSHING ACROSS THE
SOUTHERN PLAINS WILL DRAW SOME MOISTURE NORTHWARD. AT THIS POINT IT
DOES NOT APPEAR THAT MUCH MOISTURE WILL MAKE IT INTO IOWA BUT THIS
DOES BEAR WATCHING. TEMP PROFILES ARE RATHER INTERESTING AS WELL.
SOUNDINGS SHOW NEAR SURFACE TEMPS AT OR JUST BELOW FREEZING LATE
THURSDAY EVENING TO THURSDAY NIGHT BUT WE SHOULD MIX ENOUGH TO STAY
ABOVE FREEZING WITH THE POSSIBLE EXCEPTION OF THE NORTHWEST CWA. IT
IS POSSIBLE THAT FAR SOUTHERN IOWA MAY SEE SOME PATCHY DRIZZLE WITH
THE MOISTURE MOVING UP. AT THIS POINT THE MODELS REALLY KEEP ANY OF
THIS POTENTIAL SOUTH OF IOWA ALTHOUGH IT WILL BE CLOSE. I DID PUT
SOME SLIGHT CHANCE POPS IN ACROSS THE SOUTH FOR THE SAKE OF
COLLABORATION AND THE SREF AND CANADIAN DO BRING SOMETHING INTO THE
SOUTH AND EAST...HOWEVER MY CONFIDENCE IS LOW.
THAT SYSTEM THEN MOVES OFF ON FRIDAY AND TEMPS BEHIND IT ARE JUST A
BIT COOLER FOR FRIDAY NIGHT AND SATURDAY BUT STILL AT OR ABOVE
NORMAL HIGHS FOR EARLY DECEMBER.
BY LATE IN THE EXTENDED THE MODELS DEVELOP A RATHER STRONG SHORTWAVE
ACROSS CANADA AND THE NORTHERN PLAINS THAT IMPACTS THE UPPER MIDWEST
LATE SUNDAY INTO MONDAY. THE CANADIAN AND THE EURO MODELS ARE A
LITTLE STRONGER WITH THIS SYSTEM AND THEY DIG THE SHORTWAVE INTO
IOWA BUT THERE IS ALSO A SOUTHERN STREAM SHORTWAVE DURING THIS TIME
THAT DOES NOT EXACTLY PHASE WITH THE NORTHERN ONE THUS THEY DEVELOP
TWO AREAS OF PRECIP...ONE ACROSS THE NORTHERN PLAINS AND ONE ACROSS
THE SOUTHERN PLAINS LEAVING IOWA IN BETWEEN WITH LITTLE OR NO
PRECIP. BY THE TIME THE SHORTWAVES DO PHASE THE SYSTEM IS EAST OF
IOWA. WE HAD SLIGHT CHANCE POPS GOING AND I SAW NO REASON TO PULL
THEM AT THIS POINT BUT THERE CERTAINLY DOES NOT APPEAR TO BE A
GREATER CHANCE THAN THAT GIVEN THE MODEL SOLUTIONS. ALSO...TEMPS
DURING THIS PERIOD SHOULD BE WARM ENOUGH FOR RAIN SOUTH AND A MIX
NORTH DURING THE DAY AND A MIX SOUTH TO SNOW NORTH SUNDAY NIGHT.
EARLY NEXT WEEK WILL BE A LITTLE COOLER FOLLOWING THIS SYSTEM.
&&
.AVIATION...02/12Z
ISSUED AT 548 AM CST TUE DEC 2 2014
MAIN CONCERN FOR THIS PERIOD WILL BE LOW CLOUDS IN MISSOURI
ADVECTING INTO IOWA THIS MORNING. THESE MVFR CEILINGS ARE EXPECTED
TO AFFECT KOTM LATER THIS MORNING INTO THE EARLY AFTERNOON BEFORE
HEADING EASTWARD. THESE LOWER CEILINGS MAY ALSO CLIP KDSM AND KALO
BRIEFLY AS WELL. OTHERWISE...ANY OTHER CEILINGS WILL BE VFR WITH
UNRESTRICTED VISIBILITIES. SURFACE WINDS WILL BE QUITE STRONG FROM
THE SOUTH TO SOUTHWEST TODAY BUT SHOULD LIGHTEN QUICKLY THIS
EVENING AS A FRONTAL BOUNDARY PASSES THROUGH THE STATE. WINDS WILL
BECOME NORTHWEST BEHIND THE FRONT BUT NOT PARTICULARLY STRONG.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...COGIL
LONG TERM...FAB
AVIATION...COGIL
AREA FORECAST DISCUSSION...CORRECTION
NWS DES MOINES IA
510 AM CST TUE DEC 2 2014
.SHORT TERM /TODAY/...
ISSUED AT 319 AM CST TUE DEC 2 2014
SURFACE RIDGE CURRENTLY RETREATING TO THE EAST WITH WARM ADVECTION
INCREASING RAPIDLY ON BACKSIDE. PRESSURE GRADIENT TIGHTENS RAPIDLY
WITH STRONG SOUTH WINDS ALREADY IN NORTHWEST IOWA. TEMPERATURES
HAVE ALSO STABILIZED AND EVEN RISEN WITH THE INCREASED MIXING AND
CLOUD COVER ACROSS NORTHERN IOWA. WILL CONTINUE TO SEE THE WARMING
THROUGH THE DAY AS THERMAL RIDGE SLIDES INTO THE STATE BY MIDDAY.
HAVE REMAINED ON THE WARM SIDE OF GUIDANCE FOR HIGHS THIS AFTERNOON
WITH STRONG MIXING AND SOME SUNSHINE ALONG WITH LIMITED SNOW COVER
WHICH SHOULD ALLOW READINGS TO CLIMB NICELY. OF CONCERN WITH
CLOUDS...THERE IS A BROAD EXPANSE OF LOWER CLOUDINESS ACROSS
MISSOURI THIS MORNING WHICH IS LIFTING NORTHWARD ON STRONG SOUTHERLY
LOW LEVEL FLOW. BOTH RAP AND HRRR INDICATE THIS AREA OF CLOUDS
SLIDING ACROSS THE SOUTHEAST THIRD OF THE FORECAST AREA THIS MORNING
INTO EARLY AFTERNOON BEFORE EXITING TO THE EAST. THEREFORE...HAVE
GONE WITH MUCH MORE CLOUD COVERAGE ACROSS THE SOUTHEAST THROUGH
EARLY AFTERNOON BEFORE THE CLOUDS PUSH EASTWARD.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 319 AM CST TUE DEC 2 2014
THE PATTERN FOR MUCH OF THE UPPER MIDWEST REMAINS BENIGN FOR THE
EXTENDED. TONIGHT A BOUNDARY WILL WORK ITS WAY ACROSS IOWA BUT
MOISTURE IS WOEFULLY LACKING. IN FACT THERE DOESN`T APPEAR TO BE
ENOUGH TO PRODUCE MUCH CLOUD COVER. THE ONLY SENSIBLE WEATHER WILL
BE A WIND SHIFT LATE TONIGHT TO THE NORTHWEST AND SLIGHTLY COOLER
TEMPS FOR WEDNESDAY AND WEDNESDAY NIGHT.
BY LATE WEDNESDAY NIGHT AND THURSDAY THE HIGH SHIFTS EAST ALLOWING
FOR A RETURN TO A LIGHT SOUTHERLY FLOW SO TEMPS WILL BEGIN TO WARM
BACK UP ON THURSDAY. MID LEVEL MOISTURE WILL BE ENOUGH FOR SOME
CLOUD COVER SO I DID NOT GO TOO WARM ON THURSDAY. THURSDAY NIGHT
AND FRIDAY SHOULD BE A LITTLE WARMER AS DEEPER SOUTHERLY FLOW
BECOMES ESTABLISHED. HOWEVER...A SHORTWAVE PUSHING ACROSS THE
SOUTHERN PLAINS WILL DRAW SOME MOISTURE NORTHWARD. AT THIS POINT IT
DOES NOT APPEAR THAT MUCH MOISTURE WILL MAKE IT INTO IOWA BUT THIS
DOES BEAR WATCHING. TEMP PROFILES ARE RATHER INTERESTING AS WELL.
SOUNDINGS SHOW NEAR SURFACE TEMPS AT OR JUST BELOW FREEZING LATE
THURSDAY EVENING TO THURSDAY NIGHT BUT WE SHOULD MIX ENOUGH TO STAY
ABOVE FREEZING WITH THE POSSIBLE EXCEPTION OF THE NORTHWEST CWA. IT
IS POSSIBLE THAT FAR SOUTHERN IOWA MAY SEE SOME PATCHY DRIZZLE WITH
THE MOISTURE MOVING UP. AT THIS POINT THE MODELS REALLY KEEP ANY OF
THIS POTENTIAL SOUTH OF IOWA ALTHOUGH IT WILL BE CLOSE. I DID PUT
SOME SLIGHT CHANCE POPS IN ACROSS THE SOUTH FOR THE SAKE OF
COLLABORATION AND THE SREF AND CANADIAN DO BRING SOMETHING INTO THE
SOUTH AND EAST...HOWEVER MY CONFIDENCE IS LOW.
THAT SYSTEM THEN MOVES OFF ON FRIDAY AND TEMPS BEHIND IT ARE JUST A
BIT COOLER FOR FRIDAY NIGHT AND SATURDAY BUT STILL AT OR ABOVE
NORMAL HIGHS FOR EARLY DECEMBER.
BY LATE IN THE EXTENDED THE MODELS DEVELOP A RATHER STRONG SHORTWAVE
ACROSS CANADA AND THE NORTHERN PLAINS THAT IMPACTS THE UPPER MIDWEST
LATE SUNDAY INTO MONDAY. THE CANADIAN AND THE EURO MODELS ARE A
LITTLE STRONGER WITH THIS SYSTEM AND THEY DIG THE SHORTWAVE INTO
IOWA BUT THERE IS ALSO A SOUTHERN STREAM SHORTWAVE DURING THIS TIME
THAT DOES NOT EXACTLY PHASE WITH THE NORTHERN ONE THUS THEY DEVELOP
TWO AREAS OF PRECIP...ONE ACROSS THE NORTHERN PLAINS AND ONE ACROSS
THE SOUTHERN PLAINS LEAVING IOWA IN BETWEEN WITH LITTLE OR NO
PRECIP. BY THE TIME THE SHORTWAVES DO PHASE THE SYSTEM IS EAST OF
IOWA. WE HAD SLIGHT CHANCE POPS GOING AND I SAW NO REASON TO PULL
THEM AT THIS POINT BUT THERE CERTAINLY DOES NOT APPEAR TO BE A
GREATER CHANCE THAN THAT GIVEN THE MODEL SOLUTIONS. ALSO...TEMPS
DURING THIS PERIOD SHOULD BE WARM ENOUGH FOR RAIN SOUTH AND A MIX
NORTH DURING THE DAY AND A MIX SOUTH TO SNOW NORTH SUNDAY NIGHT.
EARLY NEXT WEEK WILL BE A LITTLE COOLER FOLLOWING THIS SYSTEM.
&&
.AVIATION...02/06Z
ISSUED AT 1136 PM CST MON DEC 1 2014
SLY FLOW WILL BE OVER IA THROUGH TONIGHT INTO TUE WITH A
STRENGTHENING PRESSURE GRADIENT SETTING UP OVER NWRN IA. HAVE
INTRODUCED LLWS INTO THE TAFS FOR KFOD AND KMCW UNTIL AFTER
SUNRISE WITH A STRONG LOW LEVEL JET IN PLACE. OTHERWISE...VFR
CONDITIONS WILL PREVAIL AS THE NEXT FRONTAL SYSTEM MOVES THROUGH
THE STATE LATE TUESDAY AND TUESDAY NIGHT.
OUTLOOK...VFR CONDITIONS WILL HOLD THROUGH MUCH OF THE WEEK. A
SERIES OF FRONTS WILL BRING WIND SHIFTS...BUT WEATHER IS NOT
EXPECTED WITH THEM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COGIL
LONG TERM...FAB
AVIATION...MS DEC 14
AREA FORECAST DISCUSSION
NWS DES MOINES IA
322 AM CST TUE DEC 2 2014
.SHORT TERM /TODAY/...
ISSUED AT 319 AM CST TUE DEC 2 2014
SURFACE RIDGE CURRENTLY RETREATING TO THE EAST WITH WARM ADVECTION
INCREASING RAPIDLY ON BACKSIDE. PRESSURE GRADIENT TIGHTENS RAPIDLY
WITH STRONG SOUTH WINDS ALREADY IN NORTHWEST IOWA. TEMPERATURES
HAVE ALSO STABILIZED AND EVEN RISEN WITH THE INCREASED MIXING AND
CLOUD COVER ACROSS NORTHERN IOWA. WILL CONTINUE TO SEE THE WARMING
THROUGH THE DAY AS THERMAL RIDGE SLIDES INTO THE STATE BY MIDDAY.
HAVE REMAINED ON THE WARM SIDE OF GUIDANCE FOR HIGHS THIS AFTERNOON
WITH STRONG MIXING AND SOME SUNSHINE ALONG WITH LIMITED SNOW COVER
WHICH SHOULD ALLOW READINGS TO CLIMB NICELY. OF CONCERN WITH
CLOUDS...THERE IS A BROAD EXPANSE OF LOWER CLOUDINESS ACROSS
MISSOURI THIS MORNING WHICH IS LIFTING NORTHWARD ON STRONG SOUTHERLY
LOW LEVEL FLOW. BOTH RAP AND HRRR INDICATE THIS AREA OF CLOUDS
SLIDING ACROSS THE SOUTHEAST THIRD OF THE FORECAST AREA THIS MORNING
INTO EARLY AFTERNOON BEFORE EXITING TO THE EAST. THEREFORE...HAVE
GONE WITH MUCH MORE CLOUD COVERAGE ACROSS THE SOUTHEAST THROUGH
EARLY AFTERNOON BEFORE THE CLOUDS PUSH EASTWARD.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 319 AM CST TUE DEC 2 2014
THE PATTERN FOR MUCH OF THE UPPER MIDWEST REMAINS BENIGN FOR THE
EXTENDED. TONIGHT A BOUNDARY WILL WORK ITS WAY ACROSS IOWA BUT
MOISTURE IS WOEFULLY LACKING. IN FACT THERE DOESN`T APPEAR TO BE
ENOUGH TO PRODUCE MUCH CLOUD COVER. THE ONLY SENSIBLE WEATHER WILL
BE A WIND SHIFT LATE TONIGHT TO THE NORTHWEST AND SLIGHTLY COOLER
TEMPS FOR WEDNESDAY AND WEDNESDAY NIGHT.
BY LATE WEDNESDAY NIGHT AND THURSDAY THE HIGH SHIFTS EAST ALLOWING
FOR A RETURN TO A LIGHT SOUTHERLY FLOW SO TEMPS WILL BEGIN TO WARM
BACK UP. MID LEVEL MOISTURE WILL BE ENOUGH FOR SOME CLOUD COVER SO
I DID NOT GO TOO WARM ON THURSDAY. THURSDAY NIGHT AND FRIDAY SHOULD
BE A LITTLE WARMER AS DEEPER SOUTHERLY FLOW BECOMES ESTABLISHED.
HOWEVER...A SHORTWAVE PUSHING ACROSS THE SOUTHERN PLAINS WILL DRAW
SOME MOISTURE NORTHWARD. AT THIS POINT IT DOES NOT APPEAR THAT MUCH
MOISTURE WILL MAKE IT INTO IOWA BUT THIS DOES BEAR WATCHING. TEMP
PROFILES ARE RATHER INTERESTING AS WELL. SOUNDINGS SHOW NEAR
SURFACE TEMPS AT OR JUST BELOW FREEZING LATE THURSDAY EVENING TO
THURSDAY NIGHT BUT WITHOUT ICE INTRODUCTION IT IS POSSIBLE THAT FAR
SOUTHERN IOWA MAY SEE SOME PATCHY FREEZING DRIZZLE AND BY LATE
FRIDAY MORNING TEMPS WOULD BE WARM ENOUGH TO SUPPORT DRIZZLE. AT
THIS POINT THE MODELS REALLY KEEP ANY OF THIS POTENTIAL SOUTH OF
IOWA ALTHOUGH IT WILL BE CLOSE. MY CONFIDENCE IS NOT HIGH ENOUGH TO
MENTION ANY PRECIP ON DAY 4...ESPECIALLY SINCE DURING THE CRITICAL
TIME WHEN TEMPS ARE AROUND FREEZING ALL MODELS KEEP ANY PRECIP SOUTH
OF THE STATE.
THAT SYSTEM THEN MOVES OFF ON FRIDAY AND TEMPS BEHIND IT ARE JUST A
BIT COOLER FOR FRIDAY NIGHT AND SATURDAY BUT STILL AT OR ABOVE
NORMAL HIGHS FOR EARLY DECEMBER.
BY LATE IN THE EXTENDED THE MODELS DEVELOP A RATHER STRONG SHORTWAVE
ACROSS CANADA AND THE NORTHERN PLAINS THAT IMPACTS THE UPPER MIDWEST
LATE SUNDAY INTO MONDAY. THE CANADIAN AND THE EURO MODELS ARE A
LITTLE STRONGER WITH THIS SYSTEM AND THEY DIG THE SHORTWAVE INTO
IOWA BUT THERE IS ALSO A SOUTHERN STREAM SHORTWAVE DURING THIS TIME
THAT DOES NOT EXACTLY PHASE WITH THE NORTHERN ONE THUS THEY DEVELOP
TWO AREAS OF PRECIP...ONE ACROSS THE NORTHERN PLAINS AND ONE ACROSS
THE SOUTHERN PLAINS LEAVING IOWA IN BETWEEN WITH LITTLE OR NO
PRECIP. BY THE TIME THE SHORTWAVES DO PHASE THE SYSTEM IS EAST OF
IOWA. WE HAD SLIGHT CHANCE POPS GOING AND I SAW NO REASON TO PULL
THEM AT THIS POINT BUT THERE CERTAINLY DOES NOT APPEAR TO BE A
GREATER CHANCE THAN THAT GIVEN THE MODEL SOLUTIONS. ALSO...TEMPS
DURING THIS PERIOD SHOULD BE WARM ENOUGH FOR RAIN SOUTH AND A MIX
NORTH DURING THE DAY AND A MIX SOUTH TO SNOW NORTH SUNDAY NIGHT.
EARLY NEXT WEEK WILL BE A LITTLE COOLER FOLLOWING THIS SYSTEM.
&&
.AVIATION...02/06Z
ISSUED AT 1136 PM CST MON DEC 1 2014
SLY FLOW WILL BE OVER IA THROUGH TONIGHT INTO TUE WITH A
STRENGTHENING PRESSURE GRADIENT SETTING UP OVER NWRN IA. HAVE
INTRODUCED LLWS INTO THE TAFS FOR KFOD AND KMCW UNTIL AFTER
SUNRISE WITH A STRONG LOW LEVEL JET IN PLACE. OTHERWISE...VFR
CONDITIONS WILL PREVAIL AS THE NEXT FRONTAL SYSTEM MOVES THROUGH
THE STATE LATE TUESDAY AND TUESDAY NIGHT.
OUTLOOK...VFR CONDITIONS WILL HOLD THROUGH MUCH OF THE WEEK. A
SERIES OF FRONTS WILL BRING WIND SHIFTS...BUT WEATHER IS NOT
EXPECTED WITH THEM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COGIL
LONG TERM...FAB
AVIATION...MS DEC 14
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1154 PM CST MON DEC 1 2014
.UPDATE...
ISSUED AT 921 PM CST MON DEC 1 2014
HAVE LOWERED MINS MANY AREAS WITH MAINLY CLEAR SKIES AND LIGHT WINDS
ALLOWING TEMPS TO PLUNGE AT OR JUST BELOW FCST MINS IN A FEW SITES.
CONCERNS MLI COULD BE CONSIDERABLY COLDER GIVEN DRY AIR AND FAVORABLE
E/SE WIND COMPONENT. ALSO WATCHING STRATUS OFF LAKE MICHIGAN ADVANCING
TOWARD FAR EASTERN CWA ATTIM. NAM AND RAP MODEL LOW LEVEL RH PROGS
HAVE DECENT HANDLE AND SUPPORT BRUNT OF THIS CLOUD DECK TO BRUSH
NORTHWEST IL PORTION OF CWA LATE THIS EVE INTO OVERNIGHT BEFORE
LIFTING NORTH IN DEVELOPING SE/S WINDS ON BACKSIDE OF DEPARTING
HIGH. COULD SEE SOME STRATUS FRAGMENTS AS FAR WEST AS NEAR THE
MISSISSIPPI RIVER FOR A TIME LATER TNGT. OTHERWISE... SOME MID LEVEL
WARM ADVECTION CLOUDINESS POSSIBLE GENERALLY NORTHERN CWA. LATE
TONIGHT AND ESPECIALLY TUESDAY WILL HAVE TO WATCH FOR STRATUS
OVER MO POSSIBLY LIFTING NORTHWARD OVER AREA IN STRENGTHENING
SOUTHERLY WINDS. THIS COULD HAVE BIG IMPLICATIONS TO HIGHS FOR
TUESDAY. UPDATED GRIDS AND ZFP TO BE SENT SOON.
&&
.SYNOPSIS...
ISSUED AT 321 PM CST MON DEC 1 2014
A VERY COLD AND DRY AIRMASS WAS IN PLACE OVER THE REGION THIS
AFTERNOON COURTESY OF A 1040 MB ARCTIC HIGH CENTERED OVER MN AND WI.
DENSE HIGH CLOUD COVER FILTERING THE LOW DECEMBER SUN ANGLE AND
LIGHT WINDS HAD LIMITED WARMING TO ONLY IN THE MID TEENS TO AROUND
20 AS OF 2 PM WITH DEWPOINTS ONLY IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO. A FAST ZONAL FLOW ALOFT AND LEE TROUGHING DEVELOPING
IN THE PLAINS WILL REPLACE THE HIGH WITH A RETURN FLOW AND WARMER
TEMPERATURES TUESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 321 PM CST MON DEC 1 2014
FOCUS REMAINS ON TEMPERATURES THROUGHOUT THE SHORT TERM.
TONIGHT...THE PASSAGE OF A WEAK MID LEVEL SHORTWAVE AND AXIS OF MID
LEVEL MOISTURE CURRENTLY AFFECTING THE AREA...ALONG WITH A LARGE
AREA OF CLEARING SEEN ON VISIBLE SATELLITE IMAGES UPSTREAM ACROSS
THE NEB AND KS...WOULD INDICATE A PERIOD OF CLEAR TO PARTLY CLOUDY
SKIES THIS EVENING. UNDER CLEAR SKIES...THE VERY DRY AIRMASS AND
LIGHT NE WINDS WILL LEAD TO RAPID COOLING THIS EVENING AND HAVE
TEMPERATURES COOLING BACK INTO THE SINGLE DIGITS ACROSS THE
NORTH...WITH TEENS ELSEWHERE. THE QUESTION WILL THEN BE HOW FAST THE
NEXT ROUND OF CI OVERSPREAD THE AREA AHEAD OF THE NEXT SYSTEM MOVING
THROUGH THE NORTHERN ROCKIES. FOR NOW...WILL COUNT ON THE FAST UPPER
LEVEL FLOW TO SPREAD THE SHIELD OF AT LEAST THIN CI OVER THE DAKOTAS
TO REACH INTO THE AREA AFTER MIDNIGHT TO PREVENT TEMPERATURES FROM
DROPPING MUCH LOWER. TEMPERATURES MAY THEN BECOME STEADY AROUND
SUNRISE AS A LIGHT RETURN FLOW SETS UP. FORECAST MINS FROM AROUND
7 NORTH TO 17 IN THE FAR SOUTH WOULD STILL BE A FEW DEGREES LOWER
THAN THOSE OBSERVED THIS MORNING...WHICH WOUND UP SEVERAL DEGREES
ABOVE THE EVEN WARMEST MODEL GUIDANCE FROM YESTERDAY/S FORECAST CYCLE.
TUESDAY...SOUTH WINDS AND DEEP WARM ADVECTION WILL RESULT IN WARMER
TEMPERATURES THAN TODAY...BUT LIKELY STILL BELOW NORMAL FOR EARLY DECEMBER.
HIGH CLOUDS SHOULD BE THINNER THAN TODAY. WITH SNOW COVER NEARLY
GONE OVER THE FORECAST AREA TO OFFSET WARMING...BLENDED MODEL HIGHS
FROM THE UPPER 20S IN THE FAR NORTH AND 30S ELSEWHERE LOOK
REASONABLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 321 PM CST MON DEC 1 2014
FOR THE WEEK AHEAD...BELOW NORMAL TEMPS EXPECTED THROUGH FRI THEN
NEAR AVG TEMPS THROUGH THE WEEKEND. SLIGHT CHANCE FOR LIGHT PRECIP
ON THU WHEN LIGHT RAIN OR FREEZING RAIN IS POSSIBLE. A WEAK TROUGH
OF LOW PRESSURE MAY BRING LIGHT PRECIP ON SUN AS WELL.
WEDNESDAY...A ~125 KT JET STREAK WILL MOVE RIGHT ACROSS IOWA BUT
MOST OF THE APPRECIABLE ABSOLUTE VORTICITY WILL REMAIN TO THE NORTH
OVER MN AND WI. THIS WILL KEEP ANY PRECIP CHANCES NORTH AS WELL.
PRIMARY SENSIBLE EFFECT WILL BE A SHIFT TO NW WINDS WHICH WILL USHER
IN COLDER AIR ONCE AGAIN. 850 MB TEMPS WILL FALL FROM +2 C TO -6 C
BY AFTN. HIGHS WILL RANGE FROM UPPER 20S NORTH TO UPPER 30S SOUTH.
THURSDAY AND FRIDAY..THE 300 MB PATTERN WILL TRANSITION INTO A SPLIT
FLOW WITH THE SOUTHERN BRANCH BRINGING IN PACIFIC MOISTURE ALOFT. AT
THE LOW-LEVELS...A LOW PRESSURE TROUGH WILL EXIT THE CENTRAL ROCKIES
AND TRAVERSE THE PLAINS. SW 850 MB WINDS WILL RESPOND TO AN
INCREASING PRESSURE GRADIENT...AND WAA/THETA-E ADVECTION WILL LEAD
TO SLIGHT CHANCES FOR LIGHT PRECIP. SFC FLOW WILL BE MORE OUT OF THE
E/SE...SLOWING SFC WARMING ON THU WITH HIGHS A FEW DEGREES COOLER
THAN PREVIOUS DAY. MAIN QUESTION IS HOW FAR NORTH THE LOWER LEVEL
GULF OF MEXICO MOISTURE WILL REACH INTO THE MIDWEST.
LATEST 12.1/12Z MODEL RUNS KEEP MOST OF THE AREA DRY. ALTHOUGH THE
ECMWF STILL HAS LIGHT QPF ACROSS THE CWA THU/THU NIGHT.
LOW-LEVEL ATMOSPHERE IS EXCEPTIONALLY DRY AHEAD OF THIS SYSTEM.
SFC-850 MB THETA-E ADVECTION WILL EVENTUALLY LEAD TO SATURATION IN
THIS LAYER BUT IT MAY TAKE UNTIL LATE THU EVENING WHEN LAYERED
Q-VECTOR CONVERGENCE HAS ALREADY PUSHED EAST OF AREA. IF LIGHT
PRECIP WERE TO OCCUR...MAY HAVE PRECIP TYPE ISSUES WITH 850 MB WARM
NOSE IN PLACE. INCLUDED -RA/-FZRA TO ACCOUNT FOR THIS ON THU.
SATURDAY...850-500 MB FLOW BECOMES ZONAL...SO DRY AND CALM
CONDITIONS ARE EXPECTED. TEMPS WILL NOT CHANGE MUCH GIVEN LACK OF
ANY NOTABLE THERMAL ADVECTION AND STEADY 1000-500 THICKNESSES
BETWEEN 540-546 DAM. CONSENSUS HIGHS ARE IN THE MID 30S TO LOWER 40S.
SUNDAY...POTENTIAL SHORTWAVE TROUGH MAY BRING LIGHT RAIN OR SNOW TO
THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM CST MON DEC 1 2014
POTENTIAL FOR MLI AND DBQ TO BE BRUSHED BY PERIOD OF MVFR CIGS
WITH LAKE ENHANCED STRATUS OVERNIGHT... BUT CONFIDENCE IS LOW
ATTIM WITH DEVELOPING SOUTHERLY WINDS AT 925 MB LIKELY TO STEER
DECK DUE NORTH. THUS FOR NOW HAVE HINTED AT POTENTIAL WITH
SCT020 PRIOR TO DAYBREAK AT MLI AND DBQ AND LET LATER SHIFTS
AMEND IF NEEDED. NEXT CHALLENGE IS THE DEVELOPING SOUTHERLY WINDS
AT 925 MB LIKELY TO ADVECT IN STRATUS FROM MO DURING THE DAY ON
TUESDAY WITH MAINLY VFR CIGS OF 3500-4500FT AGL AND CHANCE OF
HIGH MVFR CIGS 2500-3000FT MAINLY AT MLI AND BRL. EASTERLY WINDS
TO VEER TO SOUTH/SOUTHWEST BY TUESDAY AFTERNOON WITH SUSTAINED
SPEEDS GENERALLY 6-12 KTS. DEPTH OF SOUTHWEST WINDS SHOULD BRING
DRYING AND SCOURING OF STRATUS WITH VFR HIGH CLOUDINESS BY
TUESDAY EVENING AHEAD OF WEAK WIND SHIFT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...05
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...UTTECH
AVIATION...05
AREA FORECAST DISCUSSION
NWS GOODLAND KS
604 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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 440 PM MST WED DEC 3 2014
LARGE AREA OF LOW CLOUDS APPROACHING FROM SOUTHWEST AND SOUTH
CENTRAL KANSAS AT THIS TIME. MODELS DIFFER ON HOW FAR WEST TO TAKE
THIS CLOUD SHIELD AND DEVELOPING FOG. LOOKS LIKE MORE OF A CHANCE
FOR THE LOW CLOUDS RATHER THAN THE FOG. AT THIS TIME THIS COULD
PRIMARILY AFFECT KGLD. CONDITIONS DO NOT LOOK LIKE THEY WORSEN
UNTIL LATE IN THE EVENING.
SO INTRODUCED A SCATTERED LOW DECK AT KGLD WITH A TEMPO GROUP OF
MVFR CEILINGS AND FOG FROM 06Z TO 14Z. WILL CONTINUE TO WATCH
CLOSELY AND MAY HAVE TO RAMP UP ON THE MVFR CONDITIONS BY LATER
THIS EVENING. VFR CONDITIONS LOOK TO BE IN PLACE THROUGH THE
ENTIRE PERIOD FOR KMCK. ALTHOUGH IF SOME OF THE MORE AGGRESSIVE
MODELS COME TRUE THERE COULD BE SOME LOW CLOUDS NEAR KMCK NEAR 12Z
SO JUST INCLUDED A SCATTERED LOW DECK THERE AT THIS TIME.
OTHERWISE IT WILL BE A LIGHT AND SHIFTING WIND FIELD AT BOTH
SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...FS
LONG TERM...024
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
512 PM CST Wed Dec 3 2014
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Thursday)
Issued at 249 PM CST WED DEC 3 2014
The mid-level flow will remain fairly zonal across the region
tonight through Thursday with a weak embedded shortwave skimming
just south and east of the area. Surface high pressure was centered
over the forecast area this afternoon with a stationary boundary
extending from west to east roughly along the Oklahoma/Texas
border. Despite mid/high clouds blanketing the region with
east-northeasterly winds, afternoon temperatures were able to reach
near the seasonal normals in the low/mid 40s. Models show
precipitation developing along the stationary boundary to the
south tonight with the low-level jet helping to advect some of
that low-level moisture northward into eastern Kansas. Model
soundings show increasing low-level saturation preset by around
midnight over far east central Kansas and remaining in place
through the overnight hours into Thursday morning. Little to no
saturation is expected in the dendritic growth zone with a layer
of dry air above the shallow low-level saturation. As a result,
any precipitation that develops would likely be in the form of
drizzle. However, one of the forecast challenges is with regards
to temperatures. With increasing cloud cover expected over east
central Kansas, some guidance is suggesting that this would keep
overnight temperatures near or possibly even a couple of degrees
above the freezing mark. So this uncertainty in how low
temperatures will drop results in uncertainty in whether or not
precipitation will be in the form of drizzle or freezing drizzle.
In addition to the challenging temperature forecast, the amount of
available lift continues to look fairly weak, so have kept only
slight to low-end chance PoPs. If anything, with winds veering
toward the southeast Thursday morning, expect temperatures to
quickly warm up above the freezing mark by mid-morning, in which
any light precipitation should be in the form of drizzle.
Temperatures for Thursday should be fairly similar to today with
highs in the 40s.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 249 PM CST WED DEC 3 2014
Forecast challenge is precip chances/type Thur night-Fri. Prefer
ECMWF for this period.
The storm system now offshore of Southern CA., is forecast to race
east across the southern Rockies and into the region Thu night and
Fri. All models are consistent in bringing rain into the area after
06Z Friday lasting through the day Friday with the sfc low moving
across OK/southern MO Fri. The area will be on the north side of
the sfc system so would expect a modest diurnal range of temps
where precip does fall on Friday so have lowered highs where rain
is expected. Since the system remains offshore could still see
some adjustment of the track/timing of the storm but at this point
it looks to be all rain and anywhere from one quarter to one half
inch mainly south of I-70 at this point.
Beyond Friday...ridging will provide a dry day with near avg temps
on Saturday. Another wave will move across the region on Sunday
but moisture will be limited so any precip-rain chances will be
scattered at best with low chance wording appropriate at this
point. The pattern will amplify with a large upper low forecast to
develop across the Ohio Valley Monday into Tues. The area should
stay dry but the upper low will act to keep temps near avg with
any warm up expected to be delayed into the middle or later part
of next week.
&&
.AVIATION...(For the 00Z TAFs through 00Z Thursday Evening)
Issued at 512 PM CST WED DEC 3 2014
Main concern continues to be potential for light freezing drizzle
late tonight. Confidence in it occurring remains marginal due to
the models showing vertical motion to be very weak if it occurs
at all. Measurable precip appears unlikely at the terminals, but
have introduced a mention of light mist (BR) for TOP and FOE since
the NAM and HRRR hint at some very light QPF moving into Shawnee
county between 10Z and 11Z. Have better confidence in MVFR CIGS
moving in before sunrise as low level moisture surges north within
the low level warm air advection pattern. Have chosen to scatter
the low clouds out by early afternoon in spite of the NAM progs.
Think some mid level dry air advection and mixing of the boundary
layer will allow the MVFR CIGS to diminish.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Omitt
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS PADUCAH KY
300 PM CST Tue Dec 2 2014
.SHORT TERM...(This Afternoon through Thursday night)
Issued at 1152 AM CST TUE DEC 2 2014
Low clouds have persisted and temps are being held down as a
result. The models continue to try and decrease the low trop
moisture through tonight. But, until we see a more clear trend via
satellite, will go slower than any model suggests. We trended more
toward the RAP through the evening hours as it is the most
pessimistic.
High pressure will move across the plains, upper Midwest and
eventually Great Lakes region Wednesday through Wednesday night.
Tonight through Wednesday evening should be dry. We added back
very small chance PoPs to the SW 1/3 of the area after midnight.
Should be a minimal to trace type of event. But, from late
Wednesday night through Thursday morning, both the GFS and ECMWF
show a notable increase in 850-700mb moisture coincident with
increasing QG forcing and isentropic lift/WAA. Ignoring the QPF
forecast as a basis for precip. PoPs will be based on the models
tendency to underestimate light precip chances in this type of
setup, as both the moisture, albeit not terribly deep, is there
along with the forcing. As far as type, could be a mix of very
light rain/sprinkles/light sleet to start. Maybe a very brief
period of light freezing rain/sprinkles/light sleet Thursday
morning over the northern 1/2 of the area. Otherwise just light
rain chances through the day Thursday. Thursday night, rain
chances really ramp up especially after midnight, as mid level
energy pushes east from the central states.
Temps will be a blend of MOS, and base model output.
.LONG TERM...(Friday through Tuesday)
Issued at 300 PM CST TUE DEC 2 2014
The longer term period starts off very wet. All models agree that
shortwave energy over the Plains will move northeast accompanied by
surface low pressure development and an influx of widespread
moisture (with precipitable water values rather high from 1.0 to
1.25 inches). With good isentropic lift associated with the
low-level jet, expect widespread rain during the day Friday and much
of Friday night. Rainfall amounts of over an inch are very possible,
especially along and south/east of the Ohio River. All of the
precipitation will be liquid in the form of rain, but model
soundings Friday night into Saturday morning suggest there could be
some heavier convective showers and perhaps a few rumbles of
thunder, mainly over parts of western KY as the exit region of an
upper jet streak approaches to enhance lift.
How long the rain lingers is unclear at this time, as model runs
show varying strengths and speeds of the system. GFS and ECMWF
maintain an open wave and slightly weaker surface development, while
the GEM is deeper and slower. Overall synoptic pattern favors more
of an open progressive wave, although models at times do suppress
systems a bit too much. For now, will keep system rather
progressive but allow scattered to numerous showers to linger
Saturday before ending later in the day as the system heads east.
Thereafter, the weather should become more benign with no other
significant weather systems expected to approach the region. Thus,
will keep dry weather in the forecast on Sunday and early next week.
Temperatures Friday with the rain will be a bit tricky. Rain should
hold readings down somewhat, especially over southern IL and
southwest IN, but good southerly flow should allow moderation well
up in the 50s over much of western/southwestern KY. High and low
temperatures should remain roughly within several degrees of normal
late in the weekend and early next week.
&&
.AVIATION...
Issued at 1129 AM CST TUE DEC 2 2014
With weak advection and expansive low cloud cover persisting
across the region, will hold on to the low clouds and lower vsbys
through the end of the day and into tonight. IFR/LIFR conditions
to last a bit longer this p.m. Staring to see some movement on
the western edge from east KS into far west MO, east OK, but it
has a long way to go, and trajectories are SSW/NNE. Should
conditions improve more than anticipated, later shifts can adjust
accordingly. Winds will become light SSW and last through tonight,
then switch to NW Wednesday morning.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1152 AM CST Tue Dec 2 2014
.SHORT TERM...(This Afternoon through Thursday night)
Issued at 1152 AM CST TUE DEC 2 2014
Low clouds have persisted and temps are being held down as a
result. The models continue to try and decrease the low trop
moisture through tonight. But, until we see a more clear trend via
satellite, will go slower than any model suggests. We trended more
toward the RAP through the evening hours as it is the most
pessimistic.
High pressure will move across the plains, upper Midwest and
eventually Great Lakes region Wednesday through Wednesday night.
Tonight through Wednesday evening should be dry. We added back
very small chance PoPs to the SW 1/3 of the area after midnight.
Should be a minimal to trace type of event. But, from late
Wednesday night through Thursday morning, both the GFS and ECMWF
show a notable increase in 850-700mb moisture coincident with
increasing QG forcing and isentropic lift/waa. Ignoring the QPF
forecast as a basis for precip. PoPs will be based on the models
tendency to underestimate light precip chances in this type of
setup, as both the moisture, albeit not terribly deep, is there
along with the forcing. As far as type, could be a mix of very
light rain/sprinkles/light sleet to start. Maybe a very brief
period of light freezing rain/sprinkles/light sleet Thursday
morning over the northern 1/2 of the area. Otherwise just light
rain chances through the day Thursday. Thursday night, rain
chances really ramp up especially after midnight, as mid level
energy pushes east from the central states.
Temps will be a blend of MOS, and base model output.
.LONG TERM...(Friday through Monday)
Issued at 252 AM CST TUE DEC 2 2014
The continuation of fast zonal flow aloft will keep a fairly active
weather pattern into the long term. General agreement among the
deterministic models and their ensemble means lends relatively high
confidence through next weekend, with more uncertainty due to model
variances thereafter.
The period will start off wet as a frontal boundary enhances across
the region in response to the approach of shortwave energy aloft.
Will carry likely to categorical PoPs Friday with high end chance to
likely Friday night. Maintained the mention of showers, but kept
thunder out of the forecast for now. However, its inclusion may be
necessary if later model runs continue to hint at the potential for
weak elevated instability in close proximity to the surface wave,
especially Friday night. Precipitation will taper off from west to
east late Friday night and Saturday as the system departs.
Dry weather is expected Saturday night and Sunday as a weak mid
level ridge builds in. More uncertainty enters the forecast early
next week as the upper flow pattern transitions to northwesterly.
Whether or not we see any precipitation in this transition is
questionable at this point given the lack of agreement among model
solutions. For now, we stuck close to the initialized blend, which
strikes a good balance between the faster ECMWF and slower GFS. This
yields a small chance of rain Sunday night and Monday.
At this time, all of the precipitation in the long term appears to
be in liquid form as forecast models suggest the thermal profile
will be too warm for wintry precipitation. Of course, this can and
often does change as model solutions gain a better handle on the
systems in question.
&&
.AVIATION...
Issued at 1129 AM CST TUE DEC 2 2014
With weak advection and expansive low cloud cover persisting
across the region, will hold on to the low clouds and lower vsbys
through the end of the day and into tonight. IFR/LIFR conditions
to last a bit longer this p.m. Staring to see some movement on
the western edge from east KS into far west MO, east OK, but it
has a long way to go, and trajectories are SSW/NNE. Should
conditions improve more than anticipated, later shifts can adjust
accordingly. Winds will become light SSW and last through tonight,
then switch to NW Wednesday morning.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1129 AM CST Tue Dec 2 2014
.UPDATE...
Issued at 1129 AM CST TUE DEC 2 2014
Updated the Aviation section.
UPDATE Issued at 1052 AM CST TUE DEC 2 2014
Satellite trends, trajectories, weak flow suggest clouds will
persist, not surprising. RAP probably has best handle on clouds as
well as temps. Based the rest of the day forecast on the 13km RAP.
Other models seem to trend optimistic too fast. This is also seen in
the sounding forecast data. So, clouds, lower high temps today in
summary. Products and grids updated.
UPDATE Issued at 843 AM CST TUE DEC 2 2014
Updates right off the bat. Will have to slow down decrease in
cloud cover based on sat trends, and the RAP depiction of
persistent low level moisture. Also, areas below 1 mile vsby,
considerable 1-2 mi coverage, and drizzle. Good vsbys are
restricted to our far NW CWFA. So added that for a few hours this
morning. In fact, had a few reports of freezing drizzle as well,
that may continue a couple more hours (mid morning `ish). Grids
reflect the updates.
&&
.SHORT TERM...(Today through Thursday night)
Issued at 252 AM CST TUE DEC 2 2014
Surface High pressure builds across the TN river valley today, as
the cold front that recently made passage makes its continued move
to our east. Drier columnar air in the southern Plains will
gradually work its way into/down the column in the near term. It
should lead to some breaks in the clouds today and tonight, esp
north and west.
By Wed., the front that moved east and laid its boundary back to
our south remains the focus for moisture pooling...resulting in
extensive clouds to our south and potentially bleeding into our
southern most counties Wed night. We backed off on pcpn since both
the 00Z NAM and GFS suggested the qpf with the system stays
largely near/west of the Ozarks thru 12Z Thursday.
On Thursday, this boundary lifts back to the north and enters some
overrunning pcpn. Then Thursday Night, some energy from the
southern plains makes its way into MO, so we`ll see a marked
uptick in Pops, particularly late Thursday night.
Temps remain cool but do not offer much off highs in the 40s and
lows in the 30s thru the short term. And since we hold Pops til
Thursday, all such Pops look to be liquid.
.LONG TERM...(Friday through Monday)
Issued at 252 AM CST TUE DEC 2 2014
The continuation of fast zonal flow aloft will keep a fairly active
weather pattern into the long term. General agreement among the
deterministic models and their ensemble means lends relatively high
confidence through next weekend, with more uncertainty due to model
variances thereafter.
The period will start off wet as a frontal boundary enhances across
the region in response to the approach of shortwave energy aloft.
Will carry likely to categorical PoPs Friday with high end chance to
likely Friday night. Maintained the mention of showers, but kept
thunder out of the forecast for now. However, its inclusion may be
necessary if later model runs continue to hint at the potential for
weak elevated instability in close proximity to the surface wave,
especially Friday night. Precipitation will taper off from west to
east late Friday night and Saturday as the system departs.
Dry weather is expected Saturday night and Sunday as a weak mid
level ridge builds in. More uncertainty enters the forecast early
next week as the upper flow pattern transitions to northwesterly.
Whether or not we see any precipitation in this transition is
questionable at this point given the lack of agreement among model
solutions. For now, we stuck close to the initialized blend, which
strikes a good balance between the faster ECMWF and slower GFS. This
yields a small chance of rain Sunday night and Monday.
At this time, all of the precipitation in the long term appears to
be in liquid form as forecast models suggest the thermal profile
will be too warm for wintry precipitation. Of course, this can and
often does change as model solutions gain a better handle on the
systems in question.
&&
.AVIATION...
Issued at 1129 AM CST TUE DEC 2 2014
With weak advection and expansive low cloud cover persisting
across the region, will hold on to the low clouds and lower vsbys
through the end of the day and into tonight. IFR/LIFR conditions
to last a bit longer this p.m. Staring to see some movement on
the western edge from east KS into far west MO, east OK, but it
has a long way to go, and trajectories are SSW/NNE. Should
conditions improve more than anticipated, later shifts can adjust
accordingly. Winds will become light SSW and last through tonight,
then switch to NW Wednesday morning.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1052 AM CST Tue Dec 2 2014
.UPDATE...
Issued at 1052 AM CST TUE DEC 2 2014
Satellite trends, trajectories, weak flow suggest clouds will
persist, not surprising. RAP probably has best handle on clouds as
well as temps. Based the rest of the day forecast on the 13km RAP.
Other models seem to trend optimistic too fast. This is also seen in
the sounding forecast data. So, clouds, lower high temps today in
summary. Products and grids updated.
UPDATE Issued at 843 AM CST TUE DEC 2 2014
Updates right off the bat. Will have to slow down decrease in
cloud cover based on sat trends, and the RAP depiction of
persistent low level moisture. Also, areas below 1 mile vsby,
considerable 1-2 mi coverage, and drizzle. Good vsbys are
restricted to our far NW CWFA. So added that for a few hours this
morning. In fact, had a few reports of freezing drizzle as well,
that may continue a couple more hours (mid morning `ish). Grids
reflect the updates.
&&
.SHORT TERM...(Today through Thursday night)
Issued at 252 AM CST TUE DEC 2 2014
Surface High pressure builds across the TN river valley today, as
the cold front that recently made passage makes its continued move
to our east. Drier columnar air in the southern Plains will
gradually work its way into/down the column in the near term. It
should lead to some breaks in the clouds today and tonight, esp
north and west.
By Wed., the front that moved east and laid its boundary back to
our south remains the focus for moisture pooling...resulting in
extensive clouds to our south and potentially bleeding into our
southern most counties Wed night. We backed off on pcpn since both
the 00Z NAM and GFS suggested the qpf with the system stays
largely near/west of the Ozarks thru 12Z Thursday.
On Thursday, this boundary lifts back to the north and enters some
overrunning pcpn. Then Thursday Night, some energy from the
southern plains makes its way into MO, so we`ll see a marked
uptick in Pops, particularly late Thursday night.
Temps remain cool but do not offer much off highs in the 40s and
lows in the 30s thru the short term. And since we hold Pops til
Thursday, all such Pops look to be liquid.
.LONG TERM...(Friday through Monday)
Issued at 252 AM CST TUE DEC 2 2014
The continuation of fast zonal flow aloft will keep a fairly active
weather pattern into the long term. General agreement among the
deterministic models and their ensemble means lends relatively high
confidence through next weekend, with more uncertainty due to model
variances thereafter.
The period will start off wet as a frontal boundary enhances across
the region in response to the approach of shortwave energy aloft.
Will carry likely to categorical PoPs Friday with high end chance to
likely Friday night. Maintained the mention of showers, but kept
thunder out of the forecast for now. However, its inclusion may be
necessary if later model runs continue to hint at the potential for
weak elevated instability in close proximity to the surface wave,
especially Friday night. Precipitation will taper off from west to
east late Friday night and Saturday as the system departs.
Dry weather is expected Saturday night and Sunday as a weak mid
level ridge builds in. More uncertainty enters the forecast early
next week as the upper flow pattern transitions to northwesterly.
Whether or not we see any precipitation in this transition is
questionable at this point given the lack of agreement among model
solutions. For now, we stuck close to the initialized blend, which
strikes a good balance between the faster ECMWF and slower GFS. This
yields a small chance of rain Sunday night and Monday.
At this time, all of the precipitation in the long term appears to
be in liquid form as forecast models suggest the thermal profile
will be too warm for wintry precipitation. Of course, this can and
often does change as model solutions gain a better handle on the
systems in question.
&&
.AVIATION...
Issued at 252 AM CST TUE DEC 2 2014
MVFR cigs will be the rule, with occasional mention of IFR cigs,
thru the bulk of the morning hours. Some clearing is trying to
make its way in from the south and west, with KCGI at nearest
threat. If it does advance eastward across KPAH, it will be short-
lived, with pm hours showing redevelopnig cu anyway. A gradual
improvement from MVFR to lower VFR cigs is potentially expected.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
843 AM CST Tue Dec 2 2014
.UPDATE...
Issued at 843 AM CST TUE DEC 2 2014
Updates right off the bat. Will have to slow down decrease in
cloud cover based on sat trends, and the RAP depiction of
persistent low level moisture. Also, areas below 1 mile vsby,
considerable 1-2 mi coverage, and drizzle. Good vsbys are
restricted to our far NW CWFA. So added that for a few hours this
morning. In fact, had a few reports of freezing drizzle as well,
that may continue a couple more hours (mid morning `ish). Grids
reflect the updates.
&&
.SHORT TERM...(Today through Thursday night)
Issued at 252 AM CST TUE DEC 2 2014
Surface High pressure builds across the TN river valley today, as
the cold front that recently made passage makes its continued move
to our east. Drier columnar air in the southern Plains will
gradually work its way into/down the column in the near term. It
should lead to some breaks in the clouds today and tonight, esp
north and west.
By Wed., the front that moved east and laid its boundary back to
our south remains the focus for moisture pooling...resulting in
extensive clouds to our south and potentially bleeding into our
southern most counties Wed night. We backed off on pcpn since both
the 00Z NAM and GFS suggested the qpf with the system stays
largely near/west of the Ozarks thru 12Z Thursday.
On Thursday, this boundary lifts back to the north and enters some
overrunning pcpn. Then Thursday Night, some energy from the
southern plains makes its way into MO, so we`ll see a marked
uptick in Pops, particularly late Thursday night.
Temps remain cool but do not offer much off highs in the 40s and
lows in the 30s thru the short term. And since we hold Pops til
Thursday, all such Pops look to be liquid.
.LONG TERM...(Friday through Monday)
Issued at 252 AM CST TUE DEC 2 2014
The continuation of fast zonal flow aloft will keep a fairly active
weather pattern into the long term. General agreement among the
deterministic models and their ensemble means lends relatively high
confidence through next weekend, with more uncertainty due to model
variances thereafter.
The period will start off wet as a frontal boundary enhances across
the region in response to the approach of shortwave energy aloft.
Will carry likely to categorical PoPs Friday with high end chance to
likely Friday night. Maintained the mention of showers, but kept
thunder out of the forecast for now. However, its inclusion may be
necessary if later model runs continue to hint at the potential for
weak elevated instability in close proximity to the surface wave,
especially Friday night. Precipitation will taper off from west to
east late Friday night and Saturday as the system departs.
Dry weather is expected Saturday night and Sunday as a weak mid
level ridge builds in. More uncertainty enters the forecast early
next week as the upper flow pattern transitions to northwesterly.
Whether or not we see any precipitation in this transition is
questionable at this point given the lack of agreement among model
solutions. For now, we stuck close to the initialized blend, which
strikes a good balance between the faster ECMWF and slower GFS. This
yields a small chance of rain Sunday night and Monday.
At this time, all of the precipitation in the long term appears to
be in liquid form as forecast models suggest the thermal profile
will be too warm for wintry precipitation. Of course, this can and
often does change as model solutions gain a better handle on the
systems in question.
&&
.AVIATION...
Issued at 252 AM CST TUE DEC 2 2014
MVFR cigs will be the rule, with occasional mention of IFR cigs,
thru the bulk of the morning hours. Some clearing is trying to
make its way in from the south and west, with KCGI at nearest
threat. If it does advance eastward across KPAH, it will be short-
lived, with pm hours showing redevelopnig cu anyway. A gradual
improvement from MVFR to lower VFR cigs is potentially expected.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1236 AM EST Tue Dec 2 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 900 PM EST Mon Dec 1 2014
Precipitation coverage has dropped in the last couple of hours as
main precipitation now has shifted east of the area. Still looking
scattered rain showers for the remainder of the evening hours. A
couple of sleet reports have come in across southern Indiana. Dual
pol data and RAP soundings show freezing level between 3-4 kft, so
an occasional sleet pellet will remain possible through the evening
hours. Forecast largely on track with overnight temps holding in the
lower to middle 30s.
After coordinating with IND and PAH, introduced the chance for rain
showers and drizzle to the forecast for tomorrow for the area. This
would be mainly during the morning hours as latest guidance
continues to show some weak warm air advection precipitation
developing in conjunction with 850mb moisture transport. 01.18z
guidance picked up on this and now the HRRR and other meso models
show this developing toward sunrise. It should be another cloudy day
with highs stuck in the 40s.
Issued at 600 PM EST Mon Dec 1 2014
Main band of precipitation pushing east across south central KY into
the Bluegrass region early this evening. Areas to the north are more
spotty but likely to see drizzle with plenty of low level moisture
and weak lift in place. Temperatures are hovering in the 33 to 36
degree range for the last few hours, and not expecting further drops
as dewpoints have bottomed out or even come up a degree or two.
Still a slight chance for a sleet pellet or two across the north
where the colder air resides, but feel the main weather type this
evening and especially the overnight will be rain showers giving way
to drizzle. Have added drizzle to the forecast and adjusted POPs
for the evening hours.
Looking at some of the 01.18z data coming in, may need to raise POPs
for Tuesday or at least incorporate drizzle as forecast soundings
show low level moisture remaining in place trapped underneath a weak
inversion. With no ice present aloft and weak/moderate lift in the
low levels, drizzle would be the predominant ptype. Will evaluate
this further for a later update if necessary.
.SHORT TERM (Now through Tuesday Night)...
Issued at 300 PM EST Mon Dec 1 2014
Slow moving shallow arctic cold front will basically stall and wash
out over Tennessee. In fact, surface winds will shift to the east
tonight and then become very light Tuesday as a weak surface trough
moves across the southern Bluegrass.
Light rain will continue through mid to late afternoon north of the
Ohio River, and through late afternoon or early evening across
central Kentucky. A few sleet pellets may still mix in with rain
late this afternoon along and north of the Ohio, but temperatures
expected to stay just above freezing this afternoon will preclude
any light icing. Even by mid-evening, across our northern counties such
as Dubois and Scott, temperatures will stay at or above freezing.
Overnight lows will fall into the 30 to 33 degree range along our
northern tier of counties, and probably down to the lower 30s along
and south of the Ohio. Light rain will taper off later this evening
across our southeast.
With the approach of this surface trough, temperatures will actually
begin to warm aloft after midnight. Expect extensive cloudiness and
some drizzle overnight through mid morning Tuesday. High
temperatures will vary quite widely Tuesday from northwest to
southeast. Highs near Lake Cumberland may reach the lower to mid 50s
while staying near 40 across southwestern Indiana. Will continue
with just a slight chance of some light rain southeast of the Ohio
Tuesday, but any amounts will stay very light.
Cloudy skies will continue Tuesday night with lows in the lower to
mid 30s.
.LONG TERM (Wednesday through Monday)...
Issued at 250 PM EST Mon Dec 1 2014
The upper level pattern during the long term forecast period will
largely be zonal, with fast moving disturbances moving through the
flow and the surface boundary remaining stalled nearby. Therefore,
the main forecast concern is precipitation chances and timing.
For Wednesday, one surface boundary will be pushing through eastern
Kentucky with Canadian high pressure building in from the northwest.
Steady cold air advection and a drying airmass should keep most of
the forecast area dry, with the exception being the Cumberland
regions where the 01.12z guidance continues to suggest the front
will stall out for the afternoon. Confined POPs to that area,
keeping the rest of the forecast area dry.
Reasonable agreement that across the Ohio Valley the Wednesday night
through Thursday morning period will be under the influence of high
pressure, so the slight precipitation chances were removed. Quick
warm advection return flow will lead to increasing clouds Thursday
and some saturation and lift is focused in the mid levels.
Some of the 01.12z deterministic guidance develops precipitation by
Thursday afternoon but the trend has been slower and drier with the
moisture return, so POPs were lowered, especially during the morning
hours. If the 01.12z guidance verifies, Thursday morning will be
dry. Rain chances look to spread south to north across the area
during the afternoon and evening hours and that wave will pass to
the north Thursday night into Friday.
01.12z guidance then shows a slightly stronger wave crossing the
southern US Friday into the first part of Saturday, with rain
chances centered on Friday night. This looks to be the wettest, most
widespread rain period of the week. 60 to 70 percent POPs look good
at this point. Beyond Saturday, some signals for a drier period with
high pressure building in, especially for Sunday.
Temperatures for the remainder of the work week and this weekend are
expected to be within seasonable normals and daily diurnals will be
the low with plenty of clouds and precipitation chances. Highs upper
40s to lower 50s and lows in the upper 30s to lower 40s.
&&
.AVIATION (06Z TAF Update)...
Updated at 1235 AM EST Tue Dec 2 2014
Still seeing forecast models indicating a lowering of cigs through
the rest of the overnight, down to IFR for all sites by daybreak,
with some drizzle as well. Temperatures should remain just above
freezing at each of the terminals. These lower cigs likely will
remain for most of the day tomorrow, though we may get back into the
MVFR range by mid/late afternoon. Northeast winds now will become
more variable as a surface front to our south lifts closer to the
state and the pressure gradient loosens.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........ZT
Short Term.....JSD
Long Term......ZT
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1134 PM CST Mon Dec 1 2014
.SHORT TERM...(Tonight through Wednesday night)
Issued at 253 PM CST MON DEC 1 2014
The light precipitation activity continues to diminish across the
region. Evidence per the RAP and Wvapor imagery of a h7/h5 wave
still to our west. It`s rather weak. But there may be just enough
lift with the residual moisture, to result in some very light
precip through the evening. Both the NAM and RAP pick up on this
minimal QPF. The freezing line is expected to move little through
the night. So issued a Special Weather Statement for portions of
southeast MO, southern IL through the evening, for the potential
for spotty very light freezing rain/drizzle. Overnight, PoPs
diminish. Dry weather Tuesday through most of Wednesday. Chance of
light rain very late in the day working into southeast MO. The
chances will increase from SW to NE Wednesday night. Later in the
night through early Thursday morning, may see a light mix across
northern portions of the area. Temps were a blend of MOS, existing
numbers and base model output.
.LONG TERM...(Thursday through Sunday)
Issued at 303 PM CST MON DEC 1 2014
The GFS/ECMWF ensemble means were in general agreement on the
longwave pattern over the CONUS at this time, except on Mon (Day 7)
where the picture is a bit murkier in the swrn CONUS. We will be
lucky to see the sun in the wrn half of the area on Sat.
The finer details of the shrtwv activity were more uncertain among
the med range models, as they have had some trouble locking onto the
Pacific Express.
The extended forecast will start out with the lingering influence of
cold high sfc pressure for the PAH forecast area. By 12z Thu, model
soundings show the nrn half of the region may receive some light
freezing rain, changing to rain by mid morning. Sleet is possible.
The srn half will have rain. This should occur as moist flow aloft
begins to ride over the cooler air at the sfc.
The forecast will be very wet starting Thu night as a frontal
boundary sets up west to east somewhere across the PAH forecast
area, along with a developing wave of low pressure. The boundary is
forecast to move sewd on late on Fri in response to another shrtwv.
The best PoPs will be in the srn half of the region. Rain should
start to diminish from the nw Fri night as the system moves off, and
the region should be rain-free by Sat night under some degree of
ridging.
The ECMWF and GFS operational 12Z runs have different degrees of mid
level ridging over the weekend, and therefore the flatter GFS has
yet another shrtwv moving in from the west significantly quicker
than the ECMWF/UKMET and possibly the GEM. Therefore, what the
initialization blend provided was tamped down a bit as far as the
onset of rainfall. At this time, mainly areas west of the MS River
will have PoPs Sun. Due to model disagreement, limited chances of
rain were left in for Sun night and Mon. For now, thunder was left
out of the forecast, though it is not entirely impossible near the
low pressure wave Fri.
Expect temps to remain relatively mild through the extended period,
close to average for this time of year.
&&
.AVIATION...
Issued at 1134 PM CST MON DEC 1 2014
MVFR/IFR cigs and VFR/MVFR vsbys expected overnight. Any MVFR
vsbys will improve to VFR by 16z, but cigs will be slow to
improve, gradually increasing through MVFR to possibly low VFR by
00z. Northeast winds at 5 to 10 kts will drop to less than 5 kts
by 10z, then become southwest around 5 kts by 14z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
LONG TERM...DB
AVIATION...RST
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1206 PM CST TUE DEC 2 2014
.AVIATION...
FOR THE 02/18Z TAFS...LOW STRATUS PERSISTS ACROSS MUCH OF THE AREA
RESULTING IN MVFR/IFR FLIGHT CONDITIONS AT MOST TAF SITES. VSBYS
WILL CONTINUE TO SLOWLY IMPROVE AND CIGS MAY ALSO SLOWLY LIFT BUT
MVFR CONDITIONS SHOULD PERSIST AT MOST LOCATIONS. DESPITE ANY
IMPROVEMENTS...CIGS SHOULD LOWER AFTER SUNSET THIS EVENING ONCE
AGAIN. AREAS OF FOG MAY ALSO DEVELOP. SIMILAR TO TODAY...CIGS
SHOULD BE SLOW TO LIFT AND IMPROVE AFTER SUNRISE WEDNESDAY. A FEW
SHWRS COULD DEVELOP LATE IN THE TAF PERIOD MAINLY NORTH OF I-20
ALONG A WEAK STATIONARY FRONT. /09/
&&
.PREV DISCUSSION... /ISSUED 1108 AM CST TUE DEC 2 2014/
DISCUSSION...
UPDATED TO MAKE A FEW MINOR CHANGES TO THE WINDS...DEW POINTS...
AND RAISED THE EXPECTED DAYTIME HIGHS FOR PARTS OF NORTHEAST TEXAS
INTO NORTHWEST LOUISIANA AND SOUTHWEST ARKANSAS. PATCHY LIGHT RAIN
AND DRIZZLE OVER PARTS OF DEEP EAST TEXAS INTO LOWER NORTHWEST AND
ACROSS PARTS OF NORTH CENTRAL LOUISIANA SO LEFT RAIN CHANCES
THIS REGION. CLOUDS NOT EXPECTED TO BREAK MUCH SINCE THE MORNING
SOUNDING INDICATED AN INVERSION WITH MOISTURE UNDERNEATH IT. /06/
PREV DISCUSSION... /ISSUED 434 AM CST TUE DEC 2 2014/
DISCUSSION...
SCT AREAS OF -RA/-DZ CONTINUE FROM THE SAM RAYBURN COUNTRY OF DEEP
E TX INTO MUCH OF NCNTRL LA/SCNTRL AR THIS MORNING...GENERALLY
ALONG THE RESIDUAL 925MB TROUGH...WHERE WEAK ISENTROPIC FORCING
ALONG THE 285-290K SURFACES PERSIST. THE 00Z NAM AND HRRR HAS
INITIALIZED WELL ON THIS -RA THIS MORNING...WITH THE 925MB TROUGH
EXPECTED TO WEAKEN LATER THIS MORNING...THUS ENDING THE -RA BY
MIDDAY. HAVE CARRIED OVER SLIGHT CHANCE POPS THIS MORNING FOR
THESE AREAS...WITH MOSTLY DRY CONDITIONS EXPECTED THIS AFTERNOON
THROUGH TONIGHT AS THE MOISTURE LAYER BECOMES MORE SHALLOW WITH
TIME. THE 10Z SFC ANALYSIS INDICATES SFC RIDGING IN PLACE ACROSS
NCNTRL TX THIS MORNING...WITH THIS RIDGE EXPECTED TO SHIFT E INTO
THE REGION LATER TODAY...AND REMAIN IN PLACE ACROSS THE LOWER MS
VALLEY THROUGH WEDNESDAY. THE MODIFIED ARCTIC AIR MASS IN PLACE
ACROSS THE REGION IN WAKE OF MONDAY/S COLD FROPA WILL REMAIN QUITE
SHALLOW...WITH A VERY STEEP CAPPING INVERSION EVIDENT ON THE 02/00Z
KSHV RAOB...EXPECTED TO KEEP THE STRATUS SHIELD IN PLACE AND THUS
MAINTAINING THE COOL CONDITIONS FOR AT LEAST THE NEXT COUPLE OF
DAYS. HAVE UNDERCUT MOS MAX TEMPS AND CLOSER TO THE NAM 2M TEMPS THROUGH
WEDNESDAY...WITH WARMING EXPECTED TO BE LIMITED ESPECIALLY WHERE
THE LOW STRATUS SHIELD WILL BE A BIT DEEPER...MAINLY FROM DEEP E
TX ACROSS NCNTRL LA. SOME OF THE STRATUS MAY THIN ENOUGH FROM S TO
N BENEATH THE SFC RIDGE WEDNESDAY THAT WOULD ALLOW FOR SOME
WARMING MAINLY S OF THE I-20 CORRIDOR OF E TX/N LA...BUT
CONSIDERABLE UNCERTAINTY REMAINS AS CLOUD COVER WILL REMAIN
ABUNDANT.
THE SHORT TERM PROGS ARE IN GOOD AGREEMENT IN THE DEVELOPMENT OF
WEAK ISENTROPIC FORCING AFTER DAYBREAK WEDNESDAY OVER EXTREME NE
TX/SE OK/ADJACENT SW AR...AHEAD OF A WEAK COLD FRONT THAT WILL
SHIFT S ACROSS OK/AR AND STALL ALONG THE RED RIVER VALLEY OF N
TX/SRN OK INTO CNTRL AR. MUCH LIKE THIS PAST FRONT...THIS 2ND
FRONT WILL BE SHALLOW...BUT SHOULD BE DEEP ENOUGH TO PROVIDE
ENOUGH FRONTAL CONVERGENCE/OVERRUNNING FOR SCT -SHRA MAINLY NW OF
THE I-30 CORRIDOR. THIS FRONT IS EXPECTED TO RETURN N AWAY FROM
THE REGION THURSDAY...WITH THE AIR MASS EXPECTED TO MODIFY FURTHER
S ACROSS TX/LA...WITH MORE SEASONAL TEMPS RETURNING TO MUCH OF THE
REGION. THE GFS/ECMWF/CANADIAN REMAIN IN GOOD AGREEMENT WITH THE
NEXT PROGRESSIVE BUT WEAK SHORTWAVE TRANSLATING E ACROSS THE
DESERT SW THURSDAY AND INTO THE SRN PLAINS BY FRIDAY
MORNING...ENHANCING SCT -SHRA OVER MUCH OF THE AREA. THE
CANADIAN/ECMWF ARE A LITTLE MORE BULLISH WITH QPF THAN THE
GFS...BUT CONFIDENCE HAS INCREASED WITH BETTER RAIN COVERAGE SUCH
THAT POPS HAVE BEEN INCREASED TO LIKELY ALONG AND N OF THE I-20
CORRIDOR OF E TX/N LA. HAVE ALSO RAISED POPS TO HIGH CHANCE
FARTHER S...WITH THE -SHRA EXPECTED TO DIMINISH FROM W TO E FRIDAY
NIGHT WITH THE DEPARTING SHORTWAVE.
THE REMAINDER OF THE EXTENDED IS A LOW CONFIDENCE ONE...AS MODEL
UNCERTAINTIES INCREASE WITH THE GFS/ECMWF BY MID AND LATE WEEKEND.
THE GFS IS QUITE AGGRESSIVE WITH THE NEXT SHORTWAVE SHIFTING E
ACROSS THE SRN PLAINS/LOWER MS VALLEY SUNDAY...WITH THE ECMWF A
BIT SLOWER /BY 12 HOURS/ AND MUCH DRIER THAN THE WETTER/FASTER
GFS. PREFER THE SLOWER ECMWF AND HAVE MAINTAINED LOW CHANCE POPS
FOR THE AREA SUNDAY NIGHT/MONDAY...BEFORE TEMPS COOL SLIGHTLY WITH
THE NEXT COLD FROPA THAT WILL BUILD S EARLY NEXT WEEK.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 51 45 63 50 66 / 10 10 10 10 10
MLU 48 43 63 49 67 / 20 10 10 10 10
DEQ 48 39 52 45 60 / 0 10 30 30 30
TXK 49 42 57 48 62 / 0 10 20 20 20
ELD 49 41 59 46 63 / 10 10 10 20 20
TYR 50 44 61 53 67 / 0 10 20 20 20
GGG 50 44 61 52 67 / 0 10 20 20 20
LFK 53 47 67 53 69 / 0 0 10 10 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1108 AM CST TUE DEC 2 2014
.DISCUSSION...
UPDATED TO MAKE A FEW MINOR CHANGES TO THE WINDS...DEW POINTS...
AND RAISED THE EXPECTED DAYTIME HIGHS FOR PARTS OF NORTHEAST TEXAS
INTO NORTHWEST LOUISIANA AND SOUTHWEST ARKANSAS. PATCHY LIGHT RAIN
AND DRIZZLE OVER PARTS OF DEEP EAST TEXAS INTO LOWER NORTHWEST AND
ACROSS PARTS OF NORTH CENTRAL LOUISIANA SO LEFT RAIN CHANCES
THIS REGION. CLOUDS NOT EXPECTED TO BREAK MUCH SINCE THE MORNING
SOUNDING INDICATED AN INVERSION WITH MOISTURE UNDERNEATH IT. /06/
&&
.PREV DISCUSSION... /ISSUED 520 AM CST TUE DEC 2 2014/
AVIATION...
MVFR WEST TO IFR-VLIFR FROM KTXK DOWN TO KSHV AND POINTS EAST. AS
THE COLD AIR DEEPENS A BIT WE WILL SEE MVFR WORKING EASTWARD AND
EVEN SOME VFR CIGS LATER IN THE CYCLE OUT WEST. SFC AND LOW LEVEL
WINDS ARE NW 10-20KTS POST FROPA AND THEN BACK TO SW BY 3-4KFT AND
PICK UP SPEED A BIT. FG/DZ WILL PERSIST FOR A FEW HOURS AND SLOWLY
IMPROVE 16-20Z. EXPECTING VFR/MVFR CIGS FOR MOST SITES BY SUNSET.
LIGHTWINDS AND STILL MOIST SOIL MAY BRING SOME MVFR VSBY AND CIGS
AGAIN OVERNIGHT WITH A MUCH BETTER DAY WEDNESDAY.
PREV DISCUSSION... /ISSUED 434 AM CST TUE DEC 2 2014/
DISCUSSION...
SCT AREAS OF -RA/-DZ CONTINUE FROM THE SAM RAYBURN COUNTRY OF DEEP
E TX INTO MUCH OF NCNTRL LA/SCNTRL AR THIS MORNING...GENERALLY
ALONG THE RESIDUAL 925MB TROUGH...WHERE WEAK ISENTROPIC FORCING
ALONG THE 285-290K SURFACES PERSIST. THE 00Z NAM AND HRRR HAS
INITIALIZED WELL ON THIS -RA THIS MORNING...WITH THE 925MB TROUGH
EXPECTED TO WEAKEN LATER THIS MORNING...THUS ENDING THE -RA BY
MIDDAY. HAVE CARRIED OVER SLIGHT CHANCE POPS THIS MORNING FOR
THESE AREAS...WITH MOSTLY DRY CONDITIONS EXPECTED THIS AFTERNOON
THROUGH TONIGHT AS THE MOISTURE LAYER BECOMES MORE SHALLOW WITH
TIME. THE 10Z SFC ANALYSIS INDICATES SFC RIDGING IN PLACE ACROSS
NCNTRL TX THIS MORNING...WITH THIS RIDGE EXPECTED TO SHIFT E INTO
THE REGION LATER TODAY...AND REMAIN IN PLACE ACROSS THE LOWER MS
VALLEY THROUGH WEDNESDAY. THE MODIFIED ARCTIC AIR MASS IN PLACE
ACROSS THE REGION IN WAKE OF MONDAY/S COLD FROPA WILL REMAIN QUITE
SHALLOW...WITH A VERY STEEP CAPPING INVERSION EVIDENT ON THE 02/00Z
KSHV RAOB...EXPECTED TO KEEP THE STRATUS SHIELD IN PLACE AND THUS
MAINTAINING THE COOL CONDITIONS FOR AT LEAST THE NEXT COUPLE OF
DAYS. HAVE UNDERCUT MOS MAX TEMPS AND CLOSER TO THE NAM 2M TEMPS THROUGH
WEDNESDAY...WITH WARMING EXPECTED TO BE LIMITED ESPECIALLY WHERE
THE LOW STRATUS SHIELD WILL BE A BIT DEEPER...MAINLY FROM DEEP E
TX ACROSS NCNTRL LA. SOME OF THE STRATUS MAY THIN ENOUGH FROM S TO
N BENEATH THE SFC RIDGE WEDNESDAY THAT WOULD ALLOW FOR SOME
WARMING MAINLY S OF THE I-20 CORRIDOR OF E TX/N LA...BUT
CONSIDERABLE UNCERTAINTY REMAINS AS CLOUD COVER WILL REMAIN
ABUNDANT.
THE SHORT TERM PROGS ARE IN GOOD AGREEMENT IN THE DEVELOPMENT OF
WEAK ISENTROPIC FORCING AFTER DAYBREAK WEDNESDAY OVER EXTREME NE
TX/SE OK/ADJACENT SW AR...AHEAD OF A WEAK COLD FRONT THAT WILL
SHIFT S ACROSS OK/AR AND STALL ALONG THE RED RIVER VALLEY OF N
TX/SRN OK INTO CNTRL AR. MUCH LIKE THIS PAST FRONT...THIS 2ND
FRONT WILL BE SHALLOW...BUT SHOULD BE DEEP ENOUGH TO PROVIDE
ENOUGH FRONTAL CONVERGENCE/OVERRUNNING FOR SCT -SHRA MAINLY NW OF
THE I-30 CORRIDOR. THIS FRONT IS EXPECTED TO RETURN N AWAY FROM
THE REGION THURSDAY...WITH THE AIR MASS EXPECTED TO MODIFY FURTHER
S ACROSS TX/LA...WITH MORE SEASONAL TEMPS RETURNING TO MUCH OF THE
REGION. THE GFS/ECMWF/CANADIAN REMAIN IN GOOD AGREEMENT WITH THE
NEXT PROGRESSIVE BUT WEAK SHORTWAVE TRANSLATING E ACROSS THE
DESERT SW THURSDAY AND INTO THE SRN PLAINS BY FRIDAY
MORNING...ENHANCING SCT -SHRA OVER MUCH OF THE AREA. THE
CANADIAN/ECMWF ARE A LITTLE MORE BULLISH WITH QPF THAN THE
GFS...BUT CONFIDENCE HAS INCREASED WITH BETTER RAIN COVERAGE SUCH
THAT POPS HAVE BEEN INCREASED TO LIKELY ALONG AND N OF THE I-20
CORRIDOR OF E TX/N LA. HAVE ALSO RAISED POPS TO HIGH CHANCE
FARTHER S...WITH THE -SHRA EXPECTED TO DIMINISH FROM W TO E FRIDAY
NIGHT WITH THE DEPARTING SHORTWAVE.
THE REMAINDER OF THE EXTENDED IS A LOW CONFIDENCE ONE...AS MODEL
UNCERTAINTIES INCREASE WITH THE GFS/ECMWF BY MID AND LATE WEEKEND.
THE GFS IS QUITE AGGRESSIVE WITH THE NEXT SHORTWAVE SHIFTING E
ACROSS THE SRN PLAINS/LOWER MS VALLEY SUNDAY...WITH THE ECMWF A
BIT SLOWER /BY 12 HOURS/ AND MUCH DRIER THAN THE WETTER/FASTER
GFS. PREFER THE SLOWER ECMWF AND HAVE MAINTAINED LOW CHANCE POPS
FOR THE AREA SUNDAY NIGHT/MONDAY...BEFORE TEMPS COOL SLIGHTLY WITH
THE NEXT COLD FROPA THAT WILL BUILD S EARLY NEXT WEEK.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 51 45 63 50 66 / 10 10 10 10 10
MLU 48 43 63 49 67 / 20 10 10 10 10
DEQ 48 39 52 45 60 / 0 10 30 30 30
TXK 49 42 57 48 62 / 0 10 20 20 20
ELD 49 41 59 46 63 / 10 10 10 20 20
TYR 50 44 61 53 67 / 0 10 20 20 20
GGG 50 44 61 52 67 / 0 10 20 20 20
LFK 53 47 67 53 69 / 0 0 10 10 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
06
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
520 AM CST TUE DEC 2 2014
.AVIATION...
MVFR WEST TO IFR-VLIFR FROM KTXK DOWN TO KSHV AND POINTS EAST. AS
THE COLD AIR DEEPENS A BIT WE WILL SEE MVFR WORKING EASTWARD AND
EVEN SOME VFR CIGS LATER IN THE CYCLE OUT WEST. SFC AND LOW LEVEL
WINDS ARE NW 10-20KTS POST FROPA AND THEN BACK TO SW BY 3-4KFT AND
PICK UP SPEED A BIT. FG/DZ WILL PERSIST FOR A FEW HOURS AND SLOWLY
IMPROVE 16-20Z. EXPECTING VFR/MVFR CIGS FOR MOST SITES BY SUNSET.
LIGHTWINDS AND STILL MOIST SOIL MAY BRING SOME MVFR VSBY AND CIGS
AGAIN OVERNIGHT WITH A MUCH BETTER DAY WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 434 AM CST TUE DEC 2 2014/
DISCUSSION...
SCT AREAS OF -RA/-DZ CONTINUE FROM THE SAM RAYBURN COUNTRY OF DEEP
E TX INTO MUCH OF NCNTRL LA/SCNTRL AR THIS MORNING...GENERALLY
ALONG THE RESIDUAL 925MB TROUGH...WHERE WEAK ISENTROPIC FORCING
ALONG THE 285-290K SURFACES PERSIST. THE 00Z NAM AND HRRR HAS
INITIALIZED WELL ON THIS -RA THIS MORNING...WITH THE 925MB TROUGH
EXPECTED TO WEAKEN LATER THIS MORNING...THUS ENDING THE -RA BY
MIDDAY. HAVE CARRIED OVER SLIGHT CHANCE POPS THIS MORNING FOR
THESE AREAS...WITH MOSTLY DRY CONDITIONS EXPECTED THIS AFTERNOON
THROUGH TONIGHT AS THE MOISTURE LAYER BECOMES MORE SHALLOW WITH
TIME. THE 10Z SFC ANALYSIS INDICATES SFC RIDGING IN PLACE ACROSS
NCNTRL TX THIS MORNING...WITH THIS RIDGE EXPECTED TO SHIFT E INTO
THE REGION LATER TODAY...AND REMAIN IN PLACE ACROSS THE LOWER MS
VALLEY THROUGH WEDNESDAY. THE MODIFIED ARCTIC AIR MASS IN PLACE
ACROSS THE REGION IN WAKE OF MONDAY/S COLD FROPA WILL REMAIN QUITE
SHALLOW...WITH A VERY STEEP CAPPING INVERSION EVIDENT ON THE 02/00Z
KSHV RAOB...EXPECTED TO KEEP THE STRATUS SHIELD IN PLACE AND THUS
MAINTAINING THE COOL CONDITIONS FOR AT LEAST THE NEXT COUPLE OF
DAYS. HAVE UNDERCUT MOS MAX TEMPS AND CLOSER TO THE NAM 2M TEMPS THROUGH
WEDNESDAY...WITH WARMING EXPECTED TO BE LIMITED ESPECIALLY WHERE
THE LOW STRATUS SHIELD WILL BE A BIT DEEPER...MAINLY FROM DEEP E
TX ACROSS NCNTRL LA. SOME OF THE STRATUS MAY THIN ENOUGH FROM S TO
N BENEATH THE SFC RIDGE WEDNESDAY THAT WOULD ALLOW FOR SOME
WARMING MAINLY S OF THE I-20 CORRIDOR OF E TX/N LA...BUT
CONSIDERABLE UNCERTAINTY REMAINS AS CLOUD COVER WILL REMAIN
ABUNDANT.
THE SHORT TERM PROGS ARE IN GOOD AGREEMENT IN THE DEVELOPMENT OF
WEAK ISENTROPIC FORCING AFTER DAYBREAK WEDNESDAY OVER EXTREME NE
TX/SE OK/ADJACENT SW AR...AHEAD OF A WEAK COLD FRONT THAT WILL
SHIFT S ACROSS OK/AR AND STALL ALONG THE RED RIVER VALLEY OF N
TX/SRN OK INTO CNTRL AR. MUCH LIKE THIS PAST FRONT...THIS 2ND
FRONT WILL BE SHALLOW...BUT SHOULD BE DEEP ENOUGH TO PROVIDE
ENOUGH FRONTAL CONVERGENCE/OVERRUNNING FOR SCT -SHRA MAINLY NW OF
THE I-30 CORRIDOR. THIS FRONT IS EXPECTED TO RETURN N AWAY FROM
THE REGION THURSDAY...WITH THE AIR MASS EXPECTED TO MODIFY FURTHER
S ACROSS TX/LA...WITH MORE SEASONAL TEMPS RETURNING TO MUCH OF THE
REGION. THE GFS/ECMWF/CANADIAN REMAIN IN GOOD AGREEMENT WITH THE
NEXT PROGRESSIVE BUT WEAK SHORTWAVE TRANSLATING E ACROSS THE
DESERT SW THURSDAY AND INTO THE SRN PLAINS BY FRIDAY
MORNING...ENHANCING SCT -SHRA OVER MUCH OF THE AREA. THE
CANADIAN/ECMWF ARE A LITTLE MORE BULLISH WITH QPF THAN THE
GFS...BUT CONFIDENCE HAS INCREASED WITH BETTER RAIN COVERAGE SUCH
THAT POPS HAVE BEEN INCREASED TO LIKELY ALONG AND N OF THE I-20
CORRIDOR OF E TX/N LA. HAVE ALSO RAISED POPS TO HIGH CHANCE
FARTHER S...WITH THE -SHRA EXPECTED TO DIMINISH FROM W TO E FRIDAY
NIGHT WITH THE DEPARTING SHORTWAVE.
THE REMAINDER OF THE EXTENDED IS A LOW CONFIDENCE ONE...AS MODEL
UNCERTAINTIES INCREASE WITH THE GFS/ECMWF BY MID AND LATE WEEKEND.
THE GFS IS QUITE AGGRESSIVE WITH THE NEXT SHORTWAVE SHIFTING E
ACROSS THE SRN PLAINS/LOWER MS VALLEY SUNDAY...WITH THE ECMWF A
BIT SLOWER /BY 12 HOURS/ AND MUCH DRIER THAN THE WETTER/FASTER
GFS. PREFER THE SLOWER ECMWF AND HAVE MAINTAINED LOW CHANCE POPS
FOR THE AREA SUNDAY NIGHT/MONDAY...BEFORE TEMPS COOL SLIGHTLY WITH
THE NEXT COLD FROPA THAT WILL BUILD S EARLY NEXT WEEK.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 50 45 63 50 66 / 10 10 10 10 10
MLU 48 43 63 49 67 / 20 10 10 10 10
DEQ 48 39 52 45 60 / 10 10 30 30 30
TXK 49 42 57 48 62 / 10 10 20 20 20
ELD 48 41 59 46 63 / 20 10 10 20 20
TYR 49 44 61 53 67 / 0 10 20 20 20
GGG 49 44 61 52 67 / 0 10 20 20 20
LFK 53 47 67 53 69 / 10 0 10 10 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24/15
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
434 AM CST TUE DEC 2 2014
.DISCUSSION...
SCT AREAS OF -RA/-DZ CONTINUE FROM THE SAM RAYBURN COUNTRY OF DEEP
E TX INTO MUCH OF NCNTRL LA/SCNTRL AR THIS MORNING...GENERALLY
ALONG THE RESIDUAL 925MB TROUGH...WHERE WEAK ISENTROPIC FORCING
ALONG THE 285-290K SURFACES PERSIST. THE 00Z NAM AND HRRR HAS
INITIALIZED WELL ON THIS -RA THIS MORNING...WITH THE 925MB TROUGH
EXPECTED TO WEAKEN LATER THIS MORNING...THUS ENDING THE -RA BY
MIDDAY. HAVE CARRIED OVER SLIGHT CHANCE POPS THIS MORNING FOR
THESE AREAS...WITH MOSTLY DRY CONDITIONS EXPECTED THIS AFTERNOON
THROUGH TONIGHT AS THE MOISTURE LAYER BECOMES MORE SHALLOW WITH
TIME. THE 10Z SFC ANALYSIS INDICATES SFC RIDGING IN PLACE ACROSS
NCNTRL TX THIS MORNING...WITH THIS RIDGE EXPECTED TO SHIFT E INTO
THE REGION LATER TODAY...AND REMAIN IN PLACE ACROSS THE LOWER MS
VALLEY THROUGH WEDNESDAY. THE MODIFIED ARCTIC AIR MASS IN PLACE
ACROSS THE REGION IN WAKE OF MONDAY/S COLD FROPA WILL REMAIN QUITE
SHALLOW...WITH A VERY STEEP CAPPING INVERSION EVIDENT ON THE 02/00Z
KSHV RAOB...EXPECTED TO KEEP THE STRATUS SHIELD IN PLACE AND THUS
MAINTAINING THE COOL CONDITIONS FOR AT LEAST THE NEXT COUPLE OF
DAYS. HAVE UNDERCUT MOS MAX TEMPS AND CLOSER TO THE NAM 2M TEMPS THROUGH
WEDNESDAY...WITH WARMING EXPECTED TO BE LIMITED ESPECIALLY WHERE
THE LOW STRATUS SHIELD WILL BE A BIT DEEPER...MAINLY FROM DEEP E
TX ACROSS NCNTRL LA. SOME OF THE STRATUS MAY THIN ENOUGH FROM S TO
N BENEATH THE SFC RIDGE WEDNESDAY THAT WOULD ALLOW FOR SOME
WARMING MAINLY S OF THE I-20 CORRIDOR OF E TX/N LA...BUT
CONSIDERABLE UNCERTAINTY REMAINS AS CLOUD COVER WILL REMAIN
ABUNDANT.
THE SHORT TERM PROGS ARE IN GOOD AGREEMENT IN THE DEVELOPMENT OF
WEAK ISENTROPIC FORCING AFTER DAYBREAK WEDNESDAY OVER EXTREME NE
TX/SE OK/ADJACENT SW AR...AHEAD OF A WEAK COLD FRONT THAT WILL
SHIFT S ACROSS OK/AR AND STALL ALONG THE RED RIVER VALLEY OF N
TX/SRN OK INTO CNTRL AR. MUCH LIKE THIS PAST FRONT...THIS 2ND
FRONT WILL BE SHALLOW...BUT SHOULD BE DEEP ENOUGH TO PROVIDE
ENOUGH FRONTAL CONVERGENCE/OVERRUNNING FOR SCT -SHRA MAINLY NW OF
THE I-30 CORRIDOR. THIS FRONT IS EXPECTED TO RETURN N AWAY FROM
THE REGION THURSDAY...WITH THE AIR MASS EXPECTED TO MODIFY FURTHER
S ACROSS TX/LA...WITH MORE SEASONAL TEMPS RETURNING TO MUCH OF THE
REGION. THE GFS/ECMWF/CANADIAN REMAIN IN GOOD AGREEMENT WITH THE
NEXT PROGRESSIVE BUT WEAK SHORTWAVE TRANSLATING E ACROSS THE
DESERT SW THURSDAY AND INTO THE SRN PLAINS BY FRIDAY
MORNING...ENHANCING SCT -SHRA OVER MUCH OF THE AREA. THE
CANADIAN/ECMWF ARE A LITTLE MORE BULLISH WITH QPF THAN THE
GFS...BUT CONFIDENCE HAS INCREASED WITH BETTER RAIN COVERAGE SUCH
THAT POPS HAVE BEEN INCREASED TO LIKELY ALONG AND N OF THE I-20
CORRIDOR OF E TX/N LA. HAVE ALSO RAISED POPS TO HIGH CHANCE
FARTHER S...WITH THE -SHRA EXPECTED TO DIMINISH FROM W TO E FRIDAY
NIGHT WITH THE DEPARTING SHORTWAVE.
THE REMAINDER OF THE EXTENDED IS A LOW CONFIDENCE ONE...AS MODEL
UNCERTAINTIES INCREASE WITH THE GFS/ECMWF BY MID AND LATE WEEKEND.
THE GFS IS QUITE AGGRESSIVE WITH THE NEXT SHORTWAVE SHIFTING E
ACROSS THE SRN PLAINS/LOWER MS VALLEY SUNDAY...WITH THE ECMWF A
BIT SLOWER /BY 12 HOURS/ AND MUCH DRIER THAN THE WETTER/FASTER
GFS. PREFER THE SLOWER ECMWF AND HAVE MAINTAINED LOW CHANCE POPS
FOR THE AREA SUNDAY NIGHT/MONDAY...BEFORE TEMPS COOL SLIGHTLY WITH
THE NEXT COLD FROPA THAT WILL BUILD S EARLY NEXT WEEK.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 50 45 63 50 66 / 10 10 10 10 10
MLU 48 43 63 49 67 / 20 10 10 10 10
DEQ 48 39 52 45 60 / 10 10 30 30 30
TXK 49 42 57 48 62 / 10 10 20 20 20
ELD 48 41 59 46 63 / 20 10 10 20 20
TYR 49 44 61 53 67 / 0 10 20 20 20
GGG 49 44 61 52 67 / 0 10 20 20 20
LFK 53 47 67 53 69 / 10 0 10 10 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1159 PM CST MON DEC 1 2014
.AVIATION...
FOR THE 02/06Z TAFS...A STRONG COLD FRONT HAS CLEARED THE
AREA...BUT CIGS REMAIN LOW...LEAVING LIFR/IFR CONDITIONS AT
ELD/MLU/SHV/TXK AND MVFR CONDITIONS AT TYR/GGG/LFK. PATCHY -DZ AND
-RA WILL PERSIST OVERNIGHT AT MLU/ELD/SHV BUT SHOULD FINALLY EXIT
THE AREA BY DAYBREAK. LOW CIGS/VSBYS WILL REMAIN IN PLACE
OVERNIGHT RESULTING IN MVFR/IFR AND POSSIBLY LIFR FLIGHT CONDITIONS
THROUGH MUCH OF THE PERIOD WITH A SLOW IMPROVEMENT FROM W TO E
AFTER 02/12Z. WINDS WILL REMAIN NWLY BETWEEN 07 AND 10 KTS
THROUGH MOST OF THE TAF PERIOD. /20/
&&
.PREV DISCUSSION... /ISSUED 915 PM CST MON DEC 1 2014/
DISCUSSION...
STRONG COLD FRONT HAS CLEARED OUR ENTIRE REGION THIS EVENING
LEAVING STRONG...YET SHALLOW COLD AIR ADVECTION IN ITS WAKE.
TAKING A LOOK AT OUR 00Z SOUNDING...THE COLD AIR IS ABOUT 3KFT
THICK WITH A STRONG INVERSION NOTED AT THE 900MB LEVEL. WINDS AT
AND ABOVE THE WARM NOSE WERE STILL FROM A WSW DIRECTION. WHILE A
MAJORITY OF THE RAIN HAS MOVED OUT OF THE REGION ATTM...CANNOT
RULE OUT THE POSSIBILITY OF SOME REDEVELOPMENT OF LIGHT RAIN
AND/OR DRIZZLE OVERNIGHT.
WE SAY THIS BECAUSE A QUICK LOOK AT THE ISENTROPIC LEVEL NEAR A
THETA SFC OF 900-925MB...CONDENSATION PRESSURE DEFICITS SUPPORT
THIS POSSIBILITY. THE HRRR SHOWS THIS BEST AS WINDS APPEAR TO BACK
SLIGHTLY ABOVE THE WARM NOSE AFTER MIDNIGHT. FOR THIS REASON...
HAVE ADDED THE MENTION OF LIGHT RAIN OR DRIZZLE AS FAR WEST AS THE
TYR/GGG AREAS FOR THE REMAINDER OF THE NIGHT. ALREADY SEEING SOME
WEAK RETURNS ON RADAR SOUTH OF GGG WHICH SUPPORTS THIS THEORY.
CONCERNING OTHER CHANGES...THE PERSISTENT LIGHT RAIN/DRIZZLE
ACROSS NE LA HAS DROPPED TEMPERATURES TO AT OR NEAR FCST LOWS
OVERNIGHT SO LOWERED TEMPERATURES ACROSS PORTIONS OF NE LA INTO S
AR. OTHER CHANGES INCLUDED HOURLY TEMPERATURE AND DEWPOINT TRENDS
WHICH WERE TOO WARM GIVEN THE STRONG COLD AIR ADVECTION IN PLACE.
OTHERWISE...ALL OTHER ELEMENTS ARE IN GOOD SHAPE. UPDATED ZONE
PACKAGE OUT SHORTLY...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 38 51 46 64 54 / 20 10 10 10 20
MLU 38 50 44 64 50 / 30 10 10 10 10
DEQ 31 47 39 54 50 / 10 10 10 20 30
TXK 34 49 43 57 52 / 20 10 10 20 20
ELD 35 49 42 60 50 / 20 10 10 10 20
TYR 35 50 45 62 55 / 20 10 10 20 20
GGG 35 50 46 64 55 / 20 10 10 10 20
LFK 38 54 48 68 56 / 20 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
20
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 PM EST WED DEC 3 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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 642 PM EST WED DEC 3 2014
ALTHOUGH A COLD AND GUSTY WNW FLOW WILL PERSIST THIS EVENING OVER
WRN UPPER MI...DRY AIR MOVING IN FROM MN WILL RESULT IN DIMINISHING
LES AND IMPROVING CONDITIONS AT CMX. THE MORE EXPOSED CMX
LOCATION WILL STILL SEE STRONGER WINDS AND MORE BLSN WITH LINGERING
MVFR VSBY THIS EVENING. THE UPSLOPE FLOW AT CMX WILL ALSO KEEP CIGS NEAR
MVFR THRESHOLD TONIGHT DESPITE THE INCOMING DRY AIR UNTIL WINDS
BACKING TO SW BRINGS 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...
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR LSZ248>251-265>267.
GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ244-245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
ISSUED BY NATIONAL WEATHER SERVICE GREEN BAY WI
416 PM EST TUE DEC 2 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 415 PM EST TUE DEC 2 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SHORTWAVE
TROUGH AND ASSOCIATED COLD FRONT MOVING ACROSS THE NORTHERN
MISSISSIPPI VALLEY THIS AFTERNOON. AN AREA OF SNOW WITHIN A
MID-LEVEL FGEN BAND OVER NORTHERN WISCONSIN CONTINUES TO
DEVELOP...AND THE LATEST GUIDANCE PUSHES THIS AREA OF SNOW NORTHEAST
ACROSS THE CENTRAL UPPER PENINSULA LATER THIS AFTERNOON. STRONG
GUSTY WINDS OVER WESTERN LAKE SUPERIOR HAVE BEEN GRADUALLY
DIMINISHING WITH THE APPROACH OF THIS COLD FRONT BUT CONTINUE TO
GUST NEAR GALE FORCE OVER THE EASTERN HALF OF THE LAKE. THE MAIN
FORECAST CONCERNS INCLUDE SNOW ACCUMULATIONS FOLLOWED BY GALE
HEADLINES.
TONIGHT...THE SHORTWAVE TROUGH OVER NORTHERN MINNESOTA WILL
CONTINUE TO MOVE EAST AND ACROSS THE REGION. AHEAD OF THE
SHORTWAVE...QG FORCING/MID-LEVEL FGEN WILL COMBINE WITH MID-LEVEL
LAPSE RATES AROUND 6.5 C/KM TO PRODUCE A BAND OF SNOW ACROSS
CENTRAL AND EASTERN SECTIONS OF THE UPPER PENINSULA THIS EVENING.
MODELS PLACE THIS BAND OF SNOW AT DIFFERENT LOCATIONS...BUT
OBSERVATIONAL TRENDS SUPPORT LEANING TOWARDS THE MESO
MODELS...WHICH WOULD CREATE THIS HIGHEST SNOW AMOUNTS FROM IRON
MOUNTAIN TO WHITEFISH POINT. CANNOT RULE OUT SOME ENHANCEMENT OFF
LAKE MICHIGAN DUE TO THE SOUTHERLY WINDS AROUND MANISTIQUE AS
WELL. WILL SHOW A GENERAL 1 TO 2 INCHES IN THESE AREAS...BUT COULD
SEE LOCALLY HIGHER AMOUNTS IN THE LAKE ENHANCEMENT AREAS IF THE
MARGINAL DELTA T/S ARE SUFFICIENT. BEHIND THE SHORTWAVE...WINDS
WILL VEER TO THE WEST OVERNIGHT AND CREATE LAKE EFFECT SNOW
SHOWERS FROM ONTONAGON TO THE TIP OF THE KEWEENAW. SUBSIDENCE
BEHIND THE SHORTWAVE WILL LIMIT ACCUMS TO SUB ADVISORY LEVELS.
LOWS RANGING FROM THE MIDDLE SINGLE DIGITS SOUTH-CENTRAL TO THE
MIDDLE TEENS NEAR THE GREAT LAKES.
WEDNESDAY...AS THE SHORTWAVE EXITS THE REGION DURING THE
MORNING...VEERING WINDS TO THE WNW WILL BE COLD AND DRY AIR
ADVECTING OVER THE COURSE OF THE DAY. HIGH TEMPERATURES WILL BE A
FEW DEGREES COLDER AS A RESULT. DELTA T/S WILL BECOME MORE
FAVORABLE FOR LAKE EFFECT SNOW IN THE WESTERLY SNOW BELTS...BUT
THAT WILL BE COUNTERACTED BY THE INCOMING DRY AIRMASS.
REGARDLESS...SNOW INTENSITY SHOULD INCREASE FROM GRAND MARAIS
THROUGH WHITEFISH POINT IN THE AFTERNOON AS WIND DIRECTIONS VEER.
COULD SEE ANOTHER INCH OR TWO IN THE SNOW BELTS. HIGHS RANGING
FROM THE UPPER TEENS SOUTHWEST TO THE MIDDLE 20S EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 415 PM EST TUE DEC 2 2014
A RELATIVELY FLAT ZONAL FLOW ACROSS THE CONUS WL KEEP ARCTIC AIR
LOCKED NORTH IN CANADA AND LIMIT SNOW POTENTIAL OVER UPR MI THRU
SAT. A QUICK MOVING SHORTWAVE TROF IS FCST TO REACH THE GREAT
LAKES REGION SUNDAY NGT/MON AND BRING THE NEXT CHC OF SYNOPTIC
SNOW...LAKE EFFECT SNOW SHWRS TO THE AREA. TOO EARLY YET FOR
SPECIFICS AS THE MDLS HAVE DIFFERENCES ON THE SPEED AND DEPTH OF
THE SHORTWAVE TRFO AS WELL AS THE AMOUNT OF WARM AIR THAT MAY GET
DRAWN NORTH AHEAD OF THE SYSTEM WHICH MAY LIMIT ACCUMULATIONS.
TEMPS WL LIKELY END UP CLOSE TO NORMAL WITH BRIEF WARM-UPS
FOLLOWED BY BRIEF COOL DOWNS.
W-NW WINDS TO CONT INTO WED EVENING...BRINGING LAKE EFFECT SNOW
SHWRS TO MUCH OF THE NRN SECTION OF UPR MI. KEWEENAW...HOUGHTON...
ALGER AND LUCE COUNTIES TO BE THE MOST SUSCEPTIBLE TO ACCUMULATING
SNOW...ESPECIALLY THE LATTER 2 COUNTIES WHO HAVE THE LONGEST
FETCH. ADDITIONAL ACCUMULATIONS TO RANGE FROM AN INCH OR LESS NW
SECTIONS OF THE FORECAST AREA...TO 1 TO 3 INCHES FOR ERN SECTIONS.
THE LAKE EFFECT WL TEND TO WEAKEN OVER THE WRN U.P. LATER WED NGT
AS WINDS BEGIN TO BACK TO THE W-SW DUE TO THE PASSAGE OF A SURFACE
RIDGE OF HI PRES. BEFORE THE SURFACE RIDGE ARRIVES...IT COULD BE A
GUSTY EVENING OVER THE REGION WITH WIND GUSTS APPROACHING 30 MPH
ALONG THE LAKE SUPERIOR SHORELINE. THIS WL GENERATE BLOWING/DRIFTING
OF THE NEW SNOW. QUITE A RANGE IN TEMPS EXPECTED WED NGT BETWEEN THE
DECREASING CLODUS/DIMINISHING WINDS OVER WRN SECTIONS AND MORE
CLOUDS/WIND OVER ERN SECTIONS. LOOK FOR READINGS TO RANGE FROM A
COUPLE OF DEGS EITHER SIDE OF ZERO INTERIOR WEST TO THE MID-TEENS
FROM GRAND MARAIS EWD.
AS THE HIGH PRESSURE SLIDES TO THE EAST ON THU...RETURN FLOW
DEVELOPS ACROSS UPR MI AS WINDS BACK TO THE S-SW. PRETTY STRONG
SURGE OF WAA INDICATED BY THE MODELS AS 8H TEMPS CLIMB FROM THE
TEENS BELOW ZERO TO THE SINGLE DIGITS BELOW ZERO(C). THE
ISENTROPIC LIFT IS NOT STRONG ENUF TO ALLOW PCPN TO DEVELOP...
HOWEVER THERE IS ENUF LIFT TO BRING MORE CLOUDS BACK INTO THE
PICTURE...ESPECIALLY DURING THE AFTERNOON. THE COMBINATION OF A
COLD START TO THE DAY AND INCREASING CLOUDS WL COUNTER THE WARMING
TEMPS ALOFT...THUS MAX TEMPS TO ONLY REACH THE LOWER TO MID 20S.
QUIET CONDITIONS EXPECTED THU NGT AS THE S-SW WINDS TO PERSIST AND
LITTLE EVIDENCE OF ANY LIFTING MECHANISM ADVERTISED BY THE MODELS.
STILL A DECENT AMOUNT OF CLOUDS ANTICIPATED AND THIS WL HELP HOLD
TEMPS UP A BIT. LOOK FOR MIN TEMPS TO SETTLE MAINLY INTO THE TEENS.
A WEAK COLD FRONT IS FCST TO MOVE INTO THE REGION FRI AFTERNOON AND
VEER THE WINDS MORE TO THE W-NW BY 00Z SAT. LITTLE IN THE WAY OF
MOISTURE IS APPARENT AS A SRN STREAM SYSTEM OVER THE OZARKS/TN
VALLEY INTERCEPTS ANY GULF MOISTURE. PREFER TO LEAVE THE FCST DRY
PER PREVIOUS SHIFT. MAX TEMPS TO MAINLY BE IN THE 30-35 DEG RANGE
WITH THE WARMER READINGS IN THE EAST.
A LARGE CANADIAN HI PRES TO BE OUR MAIN WEATHER FEATURE FOR THE
FIRST HALF OF THE UPCOMING WEEKEND AND PROVIDE A MOSTLY DRY
STRETCH OF WEATHER. THE ONLY EXCEPTION WOULD BE A MINIMAL CHC OF
LAKE EFFECT SNOW SHWRS NEAR LAKE SUPERIOR DUE TO N-NW WINDS. 8H
TEMPS ONLY AROUND -8C OVER THE LAKE WOULD LIMIT SNOW POTENTIAL.
TRAJS BECOME UNFAVORABLE BY SAT...SO DRY CONDITIONS TO PREVAIL.
MAX TEMPS ON SAT TO AGAIN BE GENERALLY IN THE 30-35 DEG RANGE WITH
A FEW UPR 20S OVER THE INTERIOR WEST.
AFTER A QUIET SAT NGT...ATTENTION TURNS TO THE WEST WHERE A WEAK
SFC LOW/CDFNT AND SHORTWAVE TROF ARE PROGGED TO MOVE EAST INTO THE
UPR MS VALLEY/WRN GREAT LAKES ON SUNDAY. 12Z GFS/GEM ARE SLOWER
WITH THE MOVEMENT OF THIS SYSTEM AND BARELY GET THE LEADING EDGE
OF PCPN TO FAR WRN SECTIONS BY 00Z MON. MEANWHILE...THE ECMWF/UKMET
ARE FASTER OVERALL AND WOULD BRING THE PCPN CHCS THRU ALMOST ALL
OF UPR MI BY 00Z MON. DUE TO THE WIDE DISCREPANCY IN TIMING...HAVE
FOLLOWED THE CONSENSUS SOLUTION FOR NOW WHICH BRINGS PCPN CHCS THRU
MOST OF UPR MI SUNDAY AFTERNOON. ANOTHER POTENTIAL CONCERN IS PCPN
TYPE...ESPECIALLY IF THE GFS/GEM ARE CORRECT WHERE A MIX WOULD BE
POSSIBLE HEADED INTO SUNDAY EVENING.
THE CHCS FOR BOTH SYNOPTIC AND LAKE EFFECT SNOWS WL CONT INTO
SUNDAY NGT AS THE SYSTEM PUSHES ACROSS THE GREAT LAKES. MUCH TOO
EARLY FOR ANY ACCUMULATION NUMBERS...ESPECIALLY DUE TO THE
DIFFERENCES IN THE MODELS. LAKE EFFECT SNOW SHWRS BECOME MORE OF
AN ISSUE HEADED INTO MON AS WINDS EVENTUALLY BECOME NW AND CAA
SWEEPS SWD SENDING 8H TEMPS DOWN INTO THE -10 TO -15 DEG RANGE(C).
HAVE PLACED HIGHER CHC POPS OVER THE TYPICALLY FAVORED LOCATIONS
FROM KEWEENAW EWD. THE LAKE EFFECT POTENTIAL IS EXPECTED TO LINGER
INTO MON NGT BEFORE GRADUALLY TAPERING OFF HEADED INTO TUE AS
ANOTHER AREA OF HI PRES BUILDS INTO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT
415 PM EST TUE DEC 2 2014
A LOW PRESSURE TROUGH WILL MOVE ACROSS THE AREA FROM WEST TO EAST DURING
THE LATE AFTERNOON AND EVENING HOURS. IT WILL PRODUCE MVFR CEILINGS
AND VISIBILITIES AND SNOW SHOWERS. LOCAL IFR CONDITIONS POSSIBLE AT
CMX AND SAW. SCATTERED TO BROKEN CLOUDS BETWEEN 2000 AND 3000 FEET
FORECAST WEDNESDAY WITH SCATTERED LAKE EFFECT SNOW SHOWERS AT CMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EST TUE DEC 2 2014
SOUTHERLY GALES ARE ONGOING ACROSS THE EASTERN HALF OF THE LAKE.
SHOULD SEE WINDS DIMINISH AS A COLD FRONT APPROACHES THE
REGION BY EARLY THIS EVENING. BEHIND THE FRONT...ANOTHER W-NW GALE EVENT
WILL FOLLOW WEDNESDAY AFTERNOON AND NIGHT. BUT SINCE THE WEATHER
PATTERN IS PROGRESSIVE...THE PASSAGE OF THE TRAILING HI PRES RIDGE
THRU THE AREA ON THU WILL RESULT IN DIMINISHING/BACKING WINDS TO
THE SW FOR LATER IN THE WEEK. NO GALES ARE EXPECTED DURING THIS
TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MPC
LONG TERM...AK
AVIATION...RDM
MARINE...MPC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
411 PM EST TUE DEC 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 PM EST TUE DEC 2 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SHORTWAVE
TROUGH AND ASSOCIATED COLD FRONT MOVING ACROSS THE NORTHERN
MISSISSIPPI VALLEY THIS AFTERNOON. AN AREA OF SNOW WITHIN A
MID-LEVEL FGEN BAND OVER NORTHERN WISCONSIN CONTINUES TO
DEVELOP...AND THE LATEST GUIDANCE PUSHES THIS AREA OF SNOW NORTHEAST
ACROSS THE CENTRAL UPPER PENINSULA LATER THIS AFTERNOON. STRONG
GUSTY WINDS OVER WESTERN LAKE SUPERIOR HAVE BEEN GRADUALLY
DIMINISHING WITH THE APPROACH OF THIS COLD FRONT BUT CONTINUE TO
GUST NEAR GALE FORCE OVER THE EASTERN HALF OF THE LAKE. THE MAIN
FORECAST CONCERNS INCLUDE SNOW ACCUMULATIONS FOLLOWED BY GALE
HEADLINES.
TONIGHT...THE SHORTWAVE TROUGH OVER NORTHERN MINNESOTA WILL
CONTINUE TO MOVE EAST AND ACROSS THE REGION. AHEAD OF THE
SHORTWAVE...QG FORCING/MID-LEVEL FGEN WILL COMBINE WITH MID-LEVEL
LAPSE RATES AROUND 6.5 C/KM TO PRODUCE A BAND OF SNOW ACROSS
CENTRAL AND EASTERN SECTIONS OF THE UPPER PENINSULA THIS EVENING.
MODELS PLACE THIS BAND OF SNOW AT DIFFERENT LOCATIONS...BUT
OBSERVATIONAL TRENDS SUPPORT LEANING TOWARDS THE MESO
MODELS...WHICH WOULD CREATE THIS HIGHEST SNOW AMOUNTS FROM IRON
MOUNTAIN TO WHITEFISH POINT. CANNOT RULE OUT SOME ENHANCEMENT OFF
LAKE MICHIGAN DUE TO THE SOUTHERLY WINDS AROUND MANISTIQUE AS
WELL. WILL SHOW A GENERAL 1 TO 2 INCHES IN THESE AREAS...BUT COULD
SEE LOCALLY HIGHER AMOUNTS IN THE LAKE ENHANCEMENT AREAS IF THE
MARGINAL DELTA T/S ARE SUFFICIENT. BEHIND THE SHORTWAVE...WINDS
WILL VEER TO THE WEST OVERNIGHT AND CREATE LAKE EFFECT SNOW
SHOWERS FROM ONTONAGON TO THE TIP OF THE KEWEENAW. SUBSIDENCE
BEHIND THE SHORTWAVE WILL LIMIT ACCUMS TO SUB ADVISORY LEVELS.
LOWS RANGING FROM THE MIDDLE SINGLE DIGITS SOUTH-CENTRAL TO THE
MIDDLE TEENS NEAR THE GREAT LAKES.
WEDNESDAY...AS THE SHORTWAVE EXITS THE REGION DURING THE
MORNING...VEERING WINDS TO THE WNW WILL BE COLD AND DRY AIR
ADVECTING OVER THE COURSE OF THE DAY. HIGH TEMPERATURES WILL BE A
FEW DEGREES COLDER AS A RESULT. DELTA T/S WILL BECOME MORE
FAVORABLE FOR LAKE EFFECT SNOW IN THE WESTERLY SNOW BELTS...BUT
THAT WILL BE COUNTERACTED BY THE INCOMING DRY AIRMASS.
REGARDLESS...SNOW INTENSITY SHOULD INCREASE FROM GRAND MARAIS
THROUGH WHITEFISH POINT IN THE AFTERNOON AS WIND DIRECTIONS VEER.
COULD SEE ANOTHER INCH OR TWO IN THE SNOW BELTS. HIGHS RANGING
FROM THE UPPER TEENS SOUTHWEST TO THE MIDDLE 20S EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 410 PM EST TUE DEC 2 2014
A RELATIVELY FLAT ZONAL FLOW ACROSS THE CONUS WL KEEP ARCTIC AIR
LOCKED NORTH IN CANADA AND LIMIT SNOW POTENTIAL OVER UPR MI THRU
SAT. A QUICK MOVING SHORTWAVE TROF IS FCST TO REACH THE GREAT
LAKES REGION SUNDAY NGT/MON AND BRING THE NEXT CHC OF SYNOPTIC
SNOW...LAKE EFFECT SNOW SHWRS TO THE AREA. TOO EARLY YET FOR
SPECIFICS AS THE MDLS HAVE DIFFERENCES ON THE SPEED AND DEPTH OF
THE SHORTWAVE TRFO AS WELL AS THE AMOUNT OF WARM AIR THAT MAY GET
DRAWN NORTH AHEAD OF THE SYSTEM WHICH MAY LIMIT ACCUMULATIONS.
TEMPS WL LIKELY END UP CLOSE TO NORMAL WITH BRIEF WARM-UPS
FOLLOWED BY BRIEF COOL DOWNS.
W-NW WINDS TO CONT INTO WED EVENING...BRINGING LAKE EFFECT SNOW
SHWRS TO MUCH OF THE NRN SECTION OF UPR MI. KEWEENAW...HOUGHTON...
ALGER AND LUCE COUNTIES TO BE THE MOST SUSCEPTIBLE TO ACCUMULATING
SNOW...ESPECIALLY THE LATTER 2 COUNTIES WHO HAVE THE LONGEST
FETCH. ADDITIONAL ACCUMULATIONS TO RANGE FROM AN INCH OR LESS NW
SECTIONS OF THE FORECAST AREA...TO 1 TO 3 INCHES FOR ERN SECTIONS.
THE LAKE EFFECT WL TEND TO WEAKEN OVER THE WRN U.P. LATER WED NGT
AS WINDS BEGIN TO BACK TO THE W-SW DUE TO THE PASSAGE OF A SURFACE
RIDGE OF HI PRES. BEFORE THE SURFACE RIDGE ARRIVES...IT COULD BE A
GUSTY EVENING OVER THE REGION WITH WIND GUSTS APPROACHING 30 MPH
ALONG THE LAKE SUPERIOR SHORELINE. THIS WL GENERATE BLOWING/DRIFTING
OF THE NEW SNOW. QUITE A RANGE IN TEMPS EXPECTED WED NGT BETWEEN THE
DECREASING CLODUS/DIMINISHING WINDS OVER WRN SECTIONS AND MORE
CLOUDS/WIND OVER ERN SECTIONS. LOOK FOR READINGS TO RANGE FROM A
COUPLE OF DEGS EITHER SIDE OF ZERO INTERIOR WEST TO THE MID-TEENS
FROM GRAND MARAIS EWD.
AS THE HIGH PRESSURE SLIDES TO THE EAST ON THU...RETURN FLOW
DEVELOPS ACROSS UPR MI AS WINDS BACK TO THE S-SW. PRETTY STRONG
SURGE OF WAA INDICATED BY THE MODELS AS 8H TEMPS CLIMB FROM THE
TEENS BELOW ZERO TO THE SINGLE DIGITS BELOW ZERO(C). THE
ISENTROPIC LIFT IS NOT STRONG ENUF TO ALLOW PCPN TO DEVELOP...
HOWEVER THERE IS ENUF LIFT TO BRING MORE CLOUDS BACK INTO THE
PICTURE...ESPECIALLY DURING THE AFTERNOON. THE COMBINATION OF A
COLD START TO THE DAY AND INCREASING CLOUDS WL COUNTER THE WARMING
TEMPS ALOFT...THUS MAX TEMPS TO ONLY REACH THE LOWER TO MID 20S.
QUIET CONDITIONS EXPECTED THU NGT AS THE S-SW WINDS TO PERSIST AND
LITTLE EVIDENCE OF ANY LIFTING MECHANISM ADVERTISED BY THE MODELS.
STILL A DECENT AMOUNT OF CLOUDS ANTICIPATED AND THIS WL HELP HOLD
TEMPS UP A BIT. LOOK FOR MIN TEMPS TO SETTLE MAINLY INTO THE TEENS.
A WEAK COLD FRONT IS FCST TO MOVE INTO THE REGION FRI AFTERNOON AND
VEER THE WINDS MORE TO THE W-NW BY 00Z SAT. LITTLE IN THE WAY OF
MOISTURE IS APPARENT AS A SRN STREAM SYSTEM OVER THE OZARKS/TN
VALLEY INTERCEPTS ANY GULF MOISTURE. PREFER TO LEAVE THE FCST DRY
PER PREVIOUS SHIFT. MAX TEMPS TO MAINLY BE IN THE 30-35 DEG RANGE
WITH THE WARMER READINGS IN THE EAST.
A LARGE CANADIAN HI PRES TO BE OUR MAIN WEATHER FEATURE FOR THE
FIRST HALF OF THE UPCOMING WEEKEND AND PROVIDE A MOSTLY DRY
STRETCH OF WEATHER. THE ONLY EXCEPTION WOULD BE A MINIMAL CHC OF
LAKE EFFECT SNOW SHWRS NEAR LAKE SUPERIOR DUE TO N-NW WINDS. 8H
TEMPS ONLY AROUND -8C OVER THE LAKE WOULD LIMIT SNOW POTENTIAL.
TRAJS BECOME UNFAVORABLE BY SAT...SO DRY CONDITIONS TO PREVAIL.
MAX TEMPS ON SAT TO AGAIN BE GENERALLY IN THE 30-35 DEG RANGE WITH
A FEW UPR 20S OVER THE INTERIOR WEST.
AFTER A QUIET SAT NGT...ATTENTION TURNS TO THE WEST WHERE A WEAK
SFC LOW/CDFNT AND SHORTWAVE TROF ARE PROGGED TO MOVE EAST INTO THE
UPR MS VALLEY/WRN GREAT LAKES ON SUNDAY. 12Z GFS/GEM ARE SLOWER
WITH THE MOVEMENT OF THIS SYSTEM AND BARELY GET THE LEADING EDGE
OF PCPN TO FAR WRN SECTIONS BY 00Z MON. MEANWHILE...THE ECMWF/UKMET
ARE FASTER OVERALL AND WOULD BRING THE PCPN CHCS THRU ALMOST ALL
OF UPR MI BY 00Z MON. DUE TO THE WIDE DISCREPANCY IN TIMING...HAVE
FOLLOWED THE CONSENSUS SOLUTION FOR NOW WHICH BRINGS PCPN CHCS THRU
MOST OF UPR MI SUNDAY AFTERNOON. ANOTHER POTENTIAL CONCERN IS PCPN
TYPE...ESPECIALLY IF THE GFS/GEM ARE CORRECT WHERE A MIX WOULD BE
POSSIBLE HEADED INTO SUNDAY EVENING.
THE CHCS FOR BOTH SYNOPTIC AND LAKE EFFECT SNOWS WL CONT INTO
SUNDAY NGT AS THE SYSTEM PUSHES ACROSS THE GREAT LAKES. MUCH TOO
EARLY FOR ANY ACCUMULATION NUMBERS...ESPECIALLY DUE TO THE
DIFFERENCES IN THE MODELS. LAKE EFFECT SNOW SHWRS BECOME MORE OF
AN ISSUE HEADED INTO MON AS WINDS EVENTUALLY BECOME NW AND CAA
SWEEPS SWD SENDING 8H TEMPS DOWN INTO THE -10 TO -15 DEG RANGE(C).
HAVE PLACED HIGHER CHC POPS OVER THE TYPICALLY FAVORED LOCATIONS
FROM KEWEENAW EWD. THE LAKE EFFECT POTENTIAL IS EXPECTED TO LINGER
INTO MON NGT BEFORE GRADUALLY TAPERING OFF HEADED INTO TUE AS
ANOTHER AREA OF HI PRES BUILDS INTO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1254 PM EST TUE DEC 2 2014
A LOW PRESSURE TROUGH WILL MOVE ACROSS THE AREA FROM WEST TO EAST DURING
THE LATE AFTERNOON AND EVENING HOURS. IT WILL PRODUCE MVFR CEILINGS
AND VISIBILITIES AND SNOW SHOWERS. LOCAL IFR CONDITIONS POSSIBLE AT
CMX AND SAW. SCATTERED TO BROKEN CLOUDS BETWEEN 2000 AND 3000 FEET
FORECAST WEDNESDAY WITH SCATTERED LAKE EFFECT SNOW SHOWERS AT CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST TUE DEC 2 2014
SOUTHERLY GALES ARE ONGOING ACROSS THE EASTERN HALF OF THE LAKE.
SHOULD SEE WINDS DIMINISH AS A COLD FRONT APPROACHES THE
REGION BY EARLY THIS EVENING. BEHIND THE FRONT...ANOTHER W-NW GALE EVENT
WILL FOLLOW WEDNESDAY AFTERNOON AND NIGHT. BUT SINCE THE WEATHER
PATTERN IS PROGRESSIVE...THE PASSAGE OF THE TRAILING HI PRES RIDGE
THRU THE AREA ON THU WILL RESULT IN DIMINISHING/BACKING WINDS TO
THE SW FOR LATER IN THE WEEK. NO GALES ARE EXPECTED DURING THIS
TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...31
AVIATION...02
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1151 PM EST MON DEC 1 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 336 PM EST MON DEC 1 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A PROGRESSIVE...
NEARLY W-E FLOW ALONG THE CNDN BORDER. SHRTWV EMBEDDED WITHIN THIS
FLOW IS CURRENTLY MOVING THRU ERN ONTARIO. LLVL NW FLOW/H85 THERMAL
TROF WITH TEMPS AS LO AS -25 TO -28C RESULTED IN NUMEROUS LK EFFECT
SN SHOWERS MAINLY IN THE W-NW WIND SN BELTS. BUT STRONG SUBSIDENCE
RELATED TO DNVA/DEEP LYR QVECTOR DVGC THAT LOWERED THE INVRN BASE TO
H9-925 AS SHOWN ON THE 12Z INL/MPX RAOBS AS WELL AS TENDENCY FOR THE
LLVL FLOW TO BECOME MORE ACYC WITH APRCH OF SFC HI PRES IN SRN MN IS
LIMITING THE INTENSITY OF THE SN SHOWERS. THE SN SHOWERS ARE ALSO
SHIFTING AS THE FLOW BEGINS TO BACK WITH HI PRES MOVING INTO WI. NW
WIND GUSTS REACHED 45-50 MPH ALONG LK SUP DURING THE MRNG...BUT
WEAKENING PRES GRADIENT FOLLOWING PASSAGE OF PRES RISE CENTER THIS
MRNG IS CAUSING WINDS TO SLOWLY DIMINISH. THE HI WAVES WHIPPED UP BY
THESE STRONG WINDS...AS HI AS 15 FT...AND ABOVE NORMAL LK WATER LVLS
WARRANTED ISSUANCE OF A LK SHORE FLOOD ADVY FOR THE MORE EXPOSED
ALGER/LUCE COUNTIES THAT WL EXPIRE AT 2/00Z. LOOKING TO THE W...
SKIES ARE MOCLR IN MN UNDER HI PRES RDG/AXIS OF LOWEST PWAT OF 0.03
INCH /10-15 PCT OF NORMAL/ REPORTED ON THE 12Z MPX/INL RAOBS...BUT
MORE HI CLDS IN ADVANCE OF A SHRTWV MOVING THRU THE PAC NW/SW CANADA
ARE ALREADY PUSHING INTO WRN MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LES TRENDS LATE
TODAY...LO TEMPS TNGT WITH PASSAGE OF SFC RDG/VERY DRY AIRMASS AND
THEN POTENTIAL FOR SOME WAA PCPN ON TUE IN THE STRENGTHENING S FLOW
BTWN THE DEPARTING HI PRES AND LO PRES TROF ASSOCIATED WITH SHRTWV
NOW MOVING THRU THE ROCKIES.
LATE TODAY/TNGT...AS THE SFC HI PRES CENTER IN SRN MN SHIFTS E THRU
WI...NRN LOWER MI AND INTO QUEBEC BY 12Z TUE...THE WINDS WL BACK
STEADILY TO THE S...CAUSING LINGERING SN SHOWERS IN THE W-NW WIND SN
BELTS TO SHIFT OUT INTO THE LK BY MIDNGT OR SO. WINDS WL ALSO
DIMINISH THIS EVNG WITH THE ARRIVAL OF THE WEAKER GRADIENT
ASSOCIATED WITH THE HI. CONSIDERING THE VERY DRY INCOMING AIRMASS...
EXPECT TEMPS OVER MUCH OF THE CWA TO DIP AOB ZERO THIS EVNG. BUT
INCOMING HI CLDS RELATED TO STRENGTHENING S FLOW/ISENTROPIC ASCENT
UNDER SHARPENING PRES GRADIENT BTWN DEPARTING SFC HI TO THE E AND LO
PRES TROF IN THE PLAINS WL TEND TO LIMIT THE DIURNAL TEMP FALL AND
CAUSE TEMPS TO RISE OVERNGT. DESPITE THESE LIMITATIONS...TENDED TO
LOWER GOING FCST MIN TEMPS TOWARD -10F OVER THE INTERIOR W AND
SCENTRAL. ANOTHER CONCERN IS POTENTIAL FOR SOME SN SHOWERS TO DVLP
OVERNGT DOWNWIND OF LK MI IN THE S FLOW AND IN PRESENCE OF H85 TEMPS
AS LO AS -8 TO -10C /VS LK WATER TEMP ARND 5C AS REPORTED ON THE NRN
LK MI BUOY/. THE MAIN LIMITING FACTOR ON THE COVERAGE/INTENSITY OF
THESE SN SHOWERS WL BE LO INVRN BASE FCST NEAR 3K FT AGL AND VERY
DRY NATURE OF THE LLVL AIR. THESE SN SHOWERS WL IMPACT MAINLY DELTA
COUNTY AFTER 06Z.
TUE...AREA OF DEEP LYR QVECTOR CNVGC ASSOCIATED WITH DPVA IN ADVANCE
OF APRCHG SHRTWV/PERSISTENT ISENTROPIC ASCENT IN THE SW FLOW BTWN
ACCOMPANYING SFC TROF AND DEPARTING HI PRES IN SE CANADA ARE FCST TO
IMPACT THE CWA. THE MAIN LIMITING FACTOR TO WIDESPREAD PCPN WL BE
MARGINAL MSTR RETURN ARND THE H85 LEVEL. SINCE THE MODELS SHOW SOME
HIER H85 DEWPTS ADVECTING INTO THE E HALF IN THE AFTN UNDER THE DEEP
LYR FORCING AND WHERE THERE WL REMAIN A LK EFFECT COMPONENT IN THE
SW FLOW OFF LK MI WITH H85 TEMPS NEAR -8C...FCST THE HIER POPS/PCPN
TOTALS IN THAT AREA. NOT OUT OF THE QUESTION THERE COULD BE A FEW
INCHES OF SN IN THE ERN CWA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 313 PM EST MON DEC 1 2014
A VERY PROGRESSIVE PATTERN IS EXPECTED FOR THE LONG TERM
FORECAST...AS THE NORTHERN STREAM JET SLIDES NORTH INTO SOUTHERN
CANADA AND SWEEPS A SERIES OF COLD FRONTS OR TROUGHS EAST ACROSS THE
AREA. BETWEEN THE FRONTS/TROUGHS...AREAS OF HIGH PRESSURE WILL MOVE
THROUGH THE REGION WHICH WILL PROVIDE PERIODS OF PARTLY CLOUDY TO
CLEAR SKIES OVER THE AREA. WITH THE NORTHERN STREAM OF THE JET
SLIDING FARTHER TO THE NORTH...SHOULD SEE A GRADUAL MODERATION TO
THE TEMPERATURES THIS WEEK...POTENTIALLY EVEN BEING A FEW DEGREES
ABOVE NORMAL ON SATURDAY/SUNDAY (NORMAL HIGHS IN THE UPPER 20S TO
LOWER 30S).
THE FIRST TROUGH WILL SWEEP ACROSS THE UPPER GREAT LAKES REGION ON
TUESDAY EVENING...SHIFTING THE GUSTY SOUTHERLY WINDS TO THE WEST BY
WEDNESDAY MORNING. AHEAD OF THE TROUGH...EXPECT THERE TO BE SOME
LINGERING LAKE EFFECT OFF LAKE MICHIGAN OVER DELTA/SCHOOLCRAFT
INTIALLY IN THE EVENING...BUT QUICKLY DEPARTING WITHIN A COUPLE
HOURS. AS THAT DEPARTS...THE INITIAL SURGE OF ENERGY AND DEEPER
MOISTURE FROM THE SHORTWAVE WILL MOVE THROUGH THE EASTERN CWA AND
PRODUCE AN INCREASE IN COVERAGE/INTENSITY OF THE SNOW SHOWERS. SOME
LOCATIONS MIGHT PICK UP A QUICK INCH OR TWO OF SNOW BEFORE IT
DEPARTS SHORTLY AFTER MIDNIGHT. BEHIND THE TROUGH...BOUNDARY LAYER
WINDS WILL SHIFT TO THE WEST OR WEST-NORTHEST AND PRODUCE SOME LIGHT
LAKE EFFECT SNOW SHOWERS. ALTHOUGH 875MB TEMPS FALL TO AROUND
-15C...THE STRENGTH OF THE INVERSION AT THAT LEVEL WILL LIKELY KEEP
THE CLOUD DEPTH LIMITED AND IN TURN THE SNOWFALL AMOUNTS LIGHT. THAT
WILL CONTINUE THROUGH WEDNESDAY MORNING UNTIL A SECONDARY TROUGH
MOVES THROUGH ON WEDNESDAY AFTERNOON (ASSOCIATED WITH ANOTHER
SHORTWAVE ON THE WEST SIDE OF THE DEPARTING UPPER TROUGH). THAT
SHORTWAVE WILL USHER IN COLDER 850MB TEMPS (TO -16C)...WHILE
PROVIDING DEEPER MOISTURE AND RAISING INVERSION HEIGHTS TO 7-8KFT.
THAT WILL LEAD TO A 6-12HR PERIOD OF LIGHT TO MODERATE LAKE EFFECT
SNOW IN THE WEST-NORTHWEST WIND LOCATIONS. WHILE MUCH OF THE CLOUD
IS WITHIN THE DGZ...THINKING THE STRENGTH OF THE WINDS (GUSTING TO
30-40MPH) WILL HELP FRACTURE THE DENDRITES AND LEAD TO SNOW RATIOS
LOWER THAN NORMALLY EXPECTED IN THAT SITUATION.
THAT PERIOD OF LAKE EFFECT WILL QUICKLY DIMINISH FROM WEST TO EAST
WEDNESDAY NIGHT...AS AN AREA OF HIGH PRESSURE SHIFTS EAST INTO THE
AREA. THIS HIGH WILL CONTINUE TO THE EAST ACROSS THE UPPER GREAT
LAKES REGION ON THURSDAY MORNING AND BRING AN END TO MOST OF THE
LAKE EFFECT (OR AT LEAST PUSH IT OVER EASTERN LAKE SUPERIOR AS
WINDS BACK). WINDS WILL BACK TO THE SOUTH BEHIND THE HIGH ON
THURSDAY AFTERNOON AND NIGHT...AHEAD OF THE NEXT TROUGH THAT WILL
MOVE THROUGH THE AREA ON FRIDAY INTO FRIDAY NIGHT. THIS PERIOD
SHOULD BE FAIRLY QUIET AND EXPECT HIGHS TO RISE TOWARDS NORMAL ON
FRIDAY. WITH THE TROUGH BEING FAIRLY WEAK AS IT MOVES
THROUGH...DON/T EXPECT MUCH CHANGE IN THE CONDITIONS BEHIND THE
FRONT AS COLDEST 850MB TEMPS ARE LOCKED UP WELL TO THE NORTH AND
GENERALLY HAVE VALUES AROUND -4C OVER LAKE SUPERIOR. THIS LEADS TO
MARGINAL LAKE EFFECT CLOUD DELTA-T VALUES FRIDAY NIGHT INTO
SATURDAY AS THE NEXT AREA OF HIGH PRESSURE MOVES IN. WITH LIMITED
LOW LEVEL MOISTURE SHOWN ON THE MODELS...WILL JUST GO WITH PARTLY
CLOUDY SKIES OVER THE AREA...ESPECIALLY IN AREAS FAVORED BY
NORTHWEST WIND.
THAT NEXT AREA OF HIGH PRESSURE WILL DEPART ON SATURDAY NIGHT
ALLOWING THE NEXT SHORTWAVE AND SURFACE LOW/TROUGH TO APPROACH THE
AREA FROM THE DAKOTAS SUNDAY INTO SUNDAY NIGHT. WILL FOLLOW A
GENERAL CONSENSUS OF THE GFS/ECMWF AT THIS POINT AND SHOW SLIGHT
CHANCE POPS SPREADING ACROSS THE AREA. THE BIGGEST DIFFERENCE
BETWEEN THE MODELS COMES FROM THE AMOUNT OF COLD AIR THAT MOVES IN
BEHIND THE LOW/TROUGH ON MONDAY (850MB TEMPS OF -4C ON THE GFS AND
-8C ON THE ECMWF). EITHER WAY...THIS APPEARS MARGINAL FOR LAKE
EFFECT AND WILL SHOW DIMINISHING POPS ON MONDAY AS THE SYSTEM
DEPARTS. ALL IN ALL...SATURDAY THROUGH MONDAY THE AREA SHOULD SEE
TEMPERATURES A LITTLE ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1150 PM EST MON DEC 1 2014
DRY AIR MASS WILL ALLOW VFR CONDITIONS TO CONTINUE INTO THE MORNING
HRS AT KIWD/KCMX. MEANWHILE...WITH LAKE EFFECT CLOUDS ALREADY
ADVANCING N OVER LAKE MI IN DEVELOPING SOUTHERLY FLOW BEHIND
DEPARTING HIGH PRES...LOW MVFR CIGS WILL DEVELOP AT KSAW OVERNIGHT.
NOT OUT OF THE QUESTION THAT CIGS COULD BE IFR. OTHERWISE...AT ALL
TERMINALS...TIGHTENING PRES GRADIENT ON THE BACKSIDE OF THE HIGH
PRES RIDGE WILL RESULT IN LLWS AS WINDS INCREASE ABOVE NOCTURNAL
INVERSION. THESE STRONGER WINDS WILL TEND TO MIX OUT A BIT THIS
MORNING...RESULTING IN GUSTY SFC WINDS. AS WINDS BECOME A LITTLE
MORE SW DURING THE DAY...EXPECT LOW MVFR CIGS TO CLEAR OUT AT KSAW
LATE MORNING OR EARLY AFTN. THEN...APPROACHING DISTURBANCE MAY
SPREAD SOME -SN INTO UPPER MI THIS AFTN. IT APPEARS BETTER POTENTIAL
OF -SN IS FARTHER E AT KSAW WHERE -SN MAY BE ACCOMPANIED BY MVFR
CONDITIONS. BEHIND A PASSING COLD FRONT...LAKE EFFECT SNOW
SHOWERS/MVFR CONDITIONS WILL DEVELOP AT KCMX LATE THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 336 PM EST MON DEC 1 2014
EXPECT WINDS/FREEZING SPRAY TO DIMINISH AND BACK TOWARD THE W AND SW
WITH PASSAGE OF SFC HI PRES RDG THIS EVNG. ALLOWED GOING HEAVY
FREEZING SPRAY/GALE HEADLINES OVER THE EASTERN LAKE TO END AS
PLANNED. BUT AS THE HI MOVES STEADILY TO THE E AND ANOTHER LO PRES
TROF MOVES INTO THE NORTHERN PLAINS TONIGHT...THE PRES GRADIENT WILL
SHARPEN AND CAUSE S WINDS TO INCREASE. THERE WILL BE A PERIOD OF S
GALES MAINLY OVER THE E HALF OF THE LAKE ON TUE WHEN THE SHARPEST
GRADIENT WILL PASS OVERHEAD. ISSUED A GALE WARNING FOR LAKE SUPERIOR
OPEN WATER ZONES 264>267. THIS GALE EVENT WILL BE RELATIVELY SHORT
LIVED AS THE TROF/WEAKER GRADIENT PASSES W-E THROUGH THE UPPER LAKES
LATE TUE...WITH GALES ENDING TUE EVENING. THERE IS LIKELY TO BE
ANOTHER W-NW GALE EVENT WED AFTERNOON/NIGHT FOLLOWING A COLD FRONTAL
PASSAGE. BUT SINCE THE WEATHER PATTERN IS PROGRESSIVE...THE PASSAGE
OF THE TRAILING HI PRES RIDGE THRU THE AREA ON THU WILL RESULT IN
DIMINISHING/BACKING WINDS TO THE SW FOR LATER IN THE WEEK. NO GALES
ARE EXPECTED DURING THIS TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 10 AM TO 7 PM EST TUESDAY FOR LSZ267.
GALE WARNING FROM 7 AM TO 7 PM EST TUESDAY FOR LSZ266.
GALE WARNING FROM 7 AM TO 1 PM EST TUESDAY FOR LSZ264-265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1151 AM CST TUE DEC 2 2014
.UPDATE...
ISSUED AT 1151 AM CST TUE DEC 2 2014
UPDATED TO INCREASE POPS IN NW WI. RADAR INDICATES INCREASE
COVERAGE AND SOME INTENSITY WITH THE PRECIP SHIELD MOVING UP INTO
THE REGION. MN DOT WEB CAMS DO SHOW SOME VERY LIGHT SNOW HAS BEEN FALLING
IN THE TWIN CITIES. THE SNOW WILL DISSIPATE 00Z.
UPDATE ISSUED AT 1145 AM CST TUE DEC 2 2014
UPDATED AVIATION DISCUSSION FOR 18Z TAF ISSUANCE BELOW.
UPDATE ISSUED AT 1020 AM CST TUE DEC 2 2014
MADE MINOR CHANGES TO THIS AFTERNOON`S FORECAST. AREA OF LIGHT
SNOW SHOWERS MOVING ACROSS CENTRAL AND SOUTHERN MN WITH MOST OF
PRECIP NOT HITTING THE GROUND. ADJUSTED POPS ON CURRENT TRENDS AND
LATEST MODELS. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
AT 330 AM...CLOUDS WERE GRADUALLY INCREASING/THICKENING ACROSS THE
NORTHLAND. TEMPS WERE GENERALLY IN THE SINGLE DIGITS ABOVE
ZERO...BUT WITH GUSTY SOUTH WINDS WE DID HAVE SOME WIND CHILL
READINGS IN THE TEENS BELOW ZERO. SOME SCATTERED SNOW
SHOWERS/FLURRIES WERE FOUND ACROSS THE FAR NORTH SHORE OF LAKE
SUPERIOR AS SOUTHERLY WINDS HAVE SHIFTED LAKE EFFECT SNOW SHOWERS
ONTO THAT SECTION OF THE NORTH SHORE.
THE MAIN FOCUS FOR TODAY IS DAYTIME HIGHS AND CHANCE OF LIGHT
SNOW. THE NAM CONTINUES TO INDICATE THE POTENTIAL FOR SOME LIGHT
SNOW SPREADING INTO EC MN AND NW WI AS THE DAY WEARS ON. THE
LATEST 06Z RUN HAS SHIFTED THE BAND A BIT SOUTH...GENERALLY INTO
OUR SOUTHERN WI ZONES. MODEL QPF WOULD SUPPORT AN INCH OR SO OF
SNOW IN A RELATIVELY NARROW CORRIDOR. STILL...THE HRRR AND THE 4KM
NMM WRF DO NOT SUPPORT MUCH IN THE WAY OF PRECIPITATION ACROSS
THAT AREA THIS AFTERNOON. WITH THE ECMWF AND GFS ALSO LOOKING
REASONABLY DRY...HAVE OPTED TO ONLY HAVE CHANCE POPS ACROSS NW WI
TODAY. ACROSS THE REMAINDER OF THE AREA...WILL CARRY CHANCE/SCT
POPS ACROSS THE FAR NORTH SHORE...AND SCATTERED FLURRIES ELSEWHERE.
THE CLOUDS AND FLURRIES WILL LINGER INTO TONIGHT...AS A WEAK
TROUGH MOVES ACROSS THE REGION. BROUGHT OVERNIGHT LOWS UP A BIT AS
WINDS AND CLOUDS WILL HELP TO KEEP TEMPS UP.
HIGHS TODAY AND WEDNESDAY ARE EXPECTED TO RANGE FROM THE TEENS TO
AROUND 20. SHOULD BE A GOOD DEAL OF SUNSHINE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
THE EXTENDED PERIOD CONTINUES TO LOOK RELATIVELY QUIET WITH A
WARMING TREND.
THE UPPER FLOW WILL BE QUASI ZONAL THROUGH MOST OF THE PERIOD WITH A
COUPLE SHORTWAVES FORECAST TO PASS THROUGH/NEAR THE NORTHLAND.
HIGH PRESSURE OVER THE AREA WEDNESDAY NIGHT WILL MOVE EAST
THURSDAY...BUT MAINLY DRY CONDITIONS. WE DROPPED THE MENTION OF
FLURRIES FOR MOST AREAS ON THURSDAY AS FORCING LOOKS RATHER WEAK AND
SOUNDINGS DRY. THERE STILL MAY BE SOME LIGHT SNOW/FLURRIES ALONG
PORTIONS OF THE NORTH SHORE DUE TO SOUTHERLY WINDS LEADING TO SOME
LAKE SNOW SNOW. DELTA-T VALUES ARE NOT THAT HIGH...SO ANY
ACCUMULATION SHOULD BE LIGHT.
A SHORTWAVE WILL SLIDE ALONG THE INTERNATIONAL BORDER THURSDAY NIGHT
INTO FRIDAY. WE LEFT THE FORECAST DRY AS THIS WAVE BRUSHES THE
REGION. SOUNDINGS SHOW DRY LOW-MID LEVELS. WE MAY NEED TO ADD A POP
OR FLURRIES IF MORE MOISTURE MAKES IT INTO THE AREA.
A STRONGER CLIPPER SYSTEM WILL BRING A CHANCE FOR SNOW OR A WINTRY
MIXTURE TO PORTIONS OF THE REGION SUNDAY/SUNDAY NIGHT. AT THIS
TIME...PRECIP AMOUNTS LOOK TO BE LIGHT.
HIGH TEMPERATURES ARE EXPECTED TO BE IN THE LOWER TO MIDDLE TWENTIES
THURSDAY...THEN WARM INTO THE UPPER TWENTIES TO LOWER THIRTIES ON
SUNDAY. TEMPS WILL COOL SEVERAL DEGREES MONDAY AS COOLER AIR MOVES
IN BEHIND THE DEPARTING CLIPPER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1145 AM CST TUE DEC 2 2014
SHORT WAVE TROF AXIS CURRENTLY LOCATED OVER THE EASTERN DAKOTAS
WILL CONTINUE TO MOVE STEADILY EASTWARD THIS AFTERNOON AND
EVENING. THIS WAVE WILL BE ACCOMPANIED BY FAIRLY DECENT MID LEVEL
FRONTOGENESIS..WHICH SHOULD BE SUFFICIENT TO BRING A 2-5 HOUR
PERIOD OF LIGHT SNOW TO KHYR LATER THIS AFTERNOON..AND MAY BRING
THEM DOWN INTO THE MVFR FLIGHT CATEGORY FOR A SHORT TIME.
HOWEVER..THERE SHOULD BE A STRONG GRADIENT ON THE NORTH SIDE OF
THE SNOW..AND WE EXPECT ONLY FLURRIES AT MOST AT KDLH/KBRD..AND
MOST LIKELY ONLY A PERIOD OF LOWERED VFR CEILINGS.
OTHERWISE..SURFACE TROF AXIS WILL PASS ACROSS THE DULUTH CWA
TONIGHT..TURNING WINDS TO LIGHT WEST/NORTHWEST. MVFR CEILINGS AND
SOME LIGHT SNOW OR FLURRIES ARE ALSO EXPECTED WED MORNING AS A
STRATUS DECK ADVECTS/DEVELOPS WITHIN STRENGTHENING LOW LEVEL COLD
ADVECTION REGIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 17 5 16 3 / 20 10 0 0
INL 12 0 10 -9 / 20 10 10 0
BRD 20 5 16 3 / 20 10 0 0
HYR 20 5 18 0 / 40 20 0 0
ASX 21 9 18 3 / 40 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
UPDATE...STEWART
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1145 AM CST TUE DEC 2 2014
.UPDATE...
ISSUED AT 1145 AM CST TUE DEC 2 2014
UPDATED AVIATION DISCUSSION FOR 18Z TAF ISSUANCE BELOW.
UPDATE ISSUED AT 1020 AM CST TUE DEC 2 2014
MADE MINOR CHANGES TO THIS AFTERNOON`S FORECAST. AREA OF LIGHT
SNOW SHOWERS MOVING ACROSS CENTRAL AND SOUTHERN MN WITH MOST OF
PRECIP NOT HITTING THE GROUND. ADJUSTED POPS ON CURRENT TRENDS AND
LATEST MODELS. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
AT 330 AM...CLOUDS WERE GRADUALLY INCREASING/THICKENING ACROSS THE
NORTHLAND. TEMPS WERE GENERALLY IN THE SINGLE DIGITS ABOVE
ZERO...BUT WITH GUSTY SOUTH WINDS WE DID HAVE SOME WIND CHILL
READINGS IN THE TEENS BELOW ZERO. SOME SCATTERED SNOW
SHOWERS/FLURRIES WERE FOUND ACROSS THE FAR NORTH SHORE OF LAKE
SUPERIOR AS SOUTHERLY WINDS HAVE SHIFTED LAKE EFFECT SNOW SHOWERS
ONTO THAT SECTION OF THE NORTH SHORE.
THE MAIN FOCUS FOR TODAY IS DAYTIME HIGHS AND CHANCE OF LIGHT
SNOW. THE NAM CONTINUES TO INDICATE THE POTENTIAL FOR SOME LIGHT
SNOW SPREADING INTO EC MN AND NW WI AS THE DAY WEARS ON. THE
LATEST 06Z RUN HAS SHIFTED THE BAND A BIT SOUTH...GENERALLY INTO
OUR SOUTHERN WI ZONES. MODEL QPF WOULD SUPPORT AN INCH OR SO OF
SNOW IN A RELATIVELY NARROW CORRIDOR. STILL...THE HRRR AND THE 4KM
NMM WRF DO NOT SUPPORT MUCH IN THE WAY OF PRECIPITATION ACROSS
THAT AREA THIS AFTERNOON. WITH THE ECMWF AND GFS ALSO LOOKING
REASONABLY DRY...HAVE OPTED TO ONLY HAVE CHANCE POPS ACROSS NW WI
TODAY. ACROSS THE REMAINDER OF THE AREA...WILL CARRY CHANCE/SCT
POPS ACROSS THE FAR NORTH SHORE...AND SCATTERED FLURRIES ELSEWHERE.
THE CLOUDS AND FLURRIES WILL LINGER INTO TONIGHT...AS A WEAK
TROUGH MOVES ACROSS THE REGION. BROUGHT OVERNIGHT LOWS UP A BIT AS
WINDS AND CLOUDS WILL HELP TO KEEP TEMPS UP.
HIGHS TODAY AND WEDNESDAY ARE EXPECTED TO RANGE FROM THE TEENS TO
AROUND 20. SHOULD BE A GOOD DEAL OF SUNSHINE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
THE EXTENDED PERIOD CONTINUES TO LOOK RELATIVELY QUIET WITH A
WARMING TREND.
THE UPPER FLOW WILL BE QUASI ZONAL THROUGH MOST OF THE PERIOD WITH A
COUPLE SHORTWAVES FORECAST TO PASS THROUGH/NEAR THE NORTHLAND.
HIGH PRESSURE OVER THE AREA WEDNESDAY NIGHT WILL MOVE EAST
THURSDAY...BUT MAINLY DRY CONDITIONS. WE DROPPED THE MENTION OF
FLURRIES FOR MOST AREAS ON THURSDAY AS FORCING LOOKS RATHER WEAK AND
SOUNDINGS DRY. THERE STILL MAY BE SOME LIGHT SNOW/FLURRIES ALONG
PORTIONS OF THE NORTH SHORE DUE TO SOUTHERLY WINDS LEADING TO SOME
LAKE SNOW SNOW. DELTA-T VALUES ARE NOT THAT HIGH...SO ANY
ACCUMULATION SHOULD BE LIGHT.
A SHORTWAVE WILL SLIDE ALONG THE INTERNATIONAL BORDER THURSDAY NIGHT
INTO FRIDAY. WE LEFT THE FORECAST DRY AS THIS WAVE BRUSHES THE
REGION. SOUNDINGS SHOW DRY LOW-MID LEVELS. WE MAY NEED TO ADD A POP
OR FLURRIES IF MORE MOISTURE MAKES IT INTO THE AREA.
A STRONGER CLIPPER SYSTEM WILL BRING A CHANCE FOR SNOW OR A WINTRY
MIXTURE TO PORTIONS OF THE REGION SUNDAY/SUNDAY NIGHT. AT THIS
TIME...PRECIP AMOUNTS LOOK TO BE LIGHT.
HIGH TEMPERATURES ARE EXPECTED TO BE IN THE LOWER TO MIDDLE TWENTIES
THURSDAY...THEN WARM INTO THE UPPER TWENTIES TO LOWER THIRTIES ON
SUNDAY. TEMPS WILL COOL SEVERAL DEGREES MONDAY AS COOLER AIR MOVES
IN BEHIND THE DEPARTING CLIPPER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1145 AM CST TUE DEC 2 2014
SHORT WAVE TROF AXIS CURRENTLY LOCATED OVER THE EASTERN DAKOTAS
WILL CONTINUE TO MOVE STEADILY EASTWARD THIS AFTERNOON AND
EVENING. THIS WAVE WILL BE ACCOMPANIED BY FAIRLY DECENT MID LEVEL
FRONTOGENESIS..WHICH SHOULD BE SUFFICIENT TO BRING A 2-5 HOUR
PERIOD OF LIGHT SNOW TO KHYR LATER THIS AFTERNOON..AND MAY BRING
THEM DOWN INTO THE MVFR FLIGHT CATEGORY FOR A SHORT TIME.
HOWEVER..THERE SHOULD BE A STRONG GRADIENT ON THE NORTH SIDE OF
THE SNOW..AND WE EXPECT ONLY FLURRIES AT MOST AT KDLH/KBRD..AND
MOST LIKELY ONLY A PERIOD OF LOWERED VFR CEILINGS.
OTHERWISE..SURFACE TROF AXIS WILL PASS ACROSS THE DULUTH CWA
TONIGHT..TURNING WINDS TO LIGHT WEST/NORTHWEST. MVFR CEILINGS AND
SOME LIGHT SNOW OR FLURRIES ARE ALSO EXPECTED WED MORNING AS A
STRATUS DECK ADVECTS/DEVELOPS WITHIN STRENGTHENING LOW LEVEL COLD
ADVECTION REGIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 17 5 16 3 / 20 10 0 0
INL 12 0 10 -9 / 20 10 10 0
BRD 20 5 16 3 / 20 10 0 0
HYR 20 5 18 0 / 30 20 0 0
ASX 21 9 18 3 / 30 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1020 AM CST TUE DEC 2 2014
.UPDATE...
ISSUED AT 1020 AM CST TUE DEC 2 2014
MADE MINOR CHANGES TO THIS AFTERNOON`S FORECAST. AREA OF LIGHT
SNOW SHOWERS MOVING ACROSS CENTRAL AND SOUTHERN MN WITH MOST OF
PRECIP NOT HTTING THE GROUND. ADJUTSED POPS ON CURRENT TRENDS AND
LATEST MODELS. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
AT 330 AM...CLOUDS WERE GRADUALLY INCREASING/THICKENING ACROSS THE
NORTHLAND. TEMPS WERE GENERALLY IN THE SINGLE DIGITS ABOVE
ZERO...BUT WITH GUSTY SOUTH WINDS WE DID HAVE SOME WIND CHILL
READINGS IN THE TEENS BELOW ZERO. SOME SCATTERED SNOW
SHOWERS/FLURRIES WERE FOUND ACROSS THE FAR NORTH SHORE OF LAKE
SUPERIOR AS SOUTHERLY WINDS HAVE SHIFTED LAKE EFFECT SNOW SHOWERS
ONTO THAT SECTION OF THE NORTH SHORE.
THE MAIN FOCUS FOR TODAY IS DAYTIME HIGHS AND CHANCE OF LIGHT
SNOW. THE NAM CONTINUES TO INDICATE THE POTENTIAL FOR SOME LIGHT
SNOW SPREADING INTO EC MN AND NW WI AS THE DAY WEARS ON. THE
LATEST 06Z RUN HAS SHIFTED THE BAND A BIT SOUTH...GENERALLY INTO
OUR SOUTHERN WI ZONES. MODEL QPF WOULD SUPPORT AN INCH OR SO OF
SNOW IN A RELATIVELY NARROW CORRIDOR. STILL...THE HRRR AND THE 4KM
NMM WRF DO NOT SUPPORT MUCH IN THE WAY OF PRECIPITATION ACROSS
THAT AREA THIS AFTERNOON. WITH THE ECMWF AND GFS ALSO LOOKING
REASONABLY DRY...HAVE OPTED TO ONLY HAVE CHANCE POPS ACROSS NW WI
TODAY. ACROSS THE REMAINDER OF THE AREA...WILL CARRY CHANCE/SCT
POPS ACROSS THE FAR NORTH SHORE...AND SCATTERED FLURRIES ELSEWHERE.
THE CLOUDS AND FLURRIES WILL LINGER INTO TONIGHT...AS A WEAK
TROUGH MOVES ACROSS THE REGION. BROUGHT OVERNIGHT LOWS UP A BIT AS
WINDS AND CLOUDS WILL HELP TO KEEP TEMPS UP.
HIGHS TODAY AND WEDNESDAY ARE EXPECTED TO RANGE FROM THE TEENS TO
AROUND 20. SHOULD BE A GOOD DEAL OF SUNSHINE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
THE EXTENDED PERIOD CONTINUES TO LOOK RELATIVELY QUIET WITH A
WARMING TREND.
THE UPPER FLOW WILL BE QUASI ZONAL THROUGH MOST OF THE PERIOD WITH A
COUPLE SHORTWAVES FORECAST TO PASS THROUGH/NEAR THE NORTHLAND.
HIGH PRESSURE OVER THE AREA WEDNESDAY NIGHT WILL MOVE EAST
THURSDAY...BUT MAINLY DRY CONDITIONS. WE DROPPED THE MENTION OF
FLURRIES FOR MOST AREAS ON THURSDAY AS FORCING LOOKS RATHER WEAK AND
SOUNDINGS DRY. THERE STILL MAY BE SOME LIGHT SNOW/FLURRIES ALONG
PORTIONS OF THE NORTH SHORE DUE TO SOUTHERLY WINDS LEADING TO SOME
LAKE SNOW SNOW. DELTA-T VALUES ARE NOT THAT HIGH...SO ANY
ACCUMULATION SHOULD BE LIGHT.
A SHORTWAVE WILL SLIDE ALONG THE INTERNATIONAL BORDER THURSDAY NIGHT
INTO FRIDAY. WE LEFT THE FORECAST DRY AS THIS WAVE BRUSHES THE
REGION. SOUNDINGS SHOW DRY LOW-MID LEVELS. WE MAY NEED TO ADD A POP
OR FLURRIES IF MORE MOISTURE MAKES IT INTO THE AREA.
A STRONGER CLIPPER SYSTEM WILL BRING A CHANCE FOR SNOW OR A WINTRY
MIXTURE TO PORTIONS OF THE REGION SUNDAY/SUNDAY NIGHT. AT THIS
TIME...PRECIP AMOUNTS LOOK TO BE LIGHT.
HIGH TEMPERATURES ARE EXPECTED TO BE IN THE LOWER TO MIDDLE TWENTIES
THURSDAY...THEN WARM INTO THE UPPER TWENTIES TO LOWER THIRTIES ON
SUNDAY. TEMPS WILL COOL SEVERAL DEGREES MONDAY AS COOLER AIR MOVES
IN BEHIND THE DEPARTING CLIPPER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 539 AM CST TUE DEC 2 2014
VFR CONDITIONS WERE OCCURRING ACROSS THE NORTHLAND THIS MORNING
WITH MID TO UPPER LEVEL CLOUDS OVERHEAD. A TROUGH OF LOW PRESSURE
WILL MOVE THROUGH THE AREA TODAY BRINGING A CHANCE FOR LIGHT
SNOW/FLURRIES TO MAINLY THE KHYR AREA. A PERIOD OF MVFR CEILINGS
WILL BE POSSIBLE FOR MOST AREAS LATER THIS AFTERNOON INTO THE
EVENING. MORE MVFR CEILINGS WILL MOVE INTO WESTERN AREAS LATE IN
THE PERIOD.
GUSTY SOUTHERLY WINDS WILL DIMINISH TODAY AND GRADUALLY VEER TO W/SW.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 17 5 16 3 / 20 10 0 0
INL 12 0 10 -9 / 20 10 10 0
BRD 20 5 16 3 / 20 10 0 0
HYR 20 5 18 0 / 30 20 0 0
ASX 21 9 18 3 / 30 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
UPDATE...STEWART
SHORT TERM...DAP
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
539 AM CST TUE DEC 2 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
AT 330 AM...CLOUDS WERE GRADUALLY INCREASING/THICKENING ACROSS THE
NORTHLAND. TEMPS WERE GENERALLY IN THE SINGLE DIGITS ABOVE
ZERO...BUT WITH GUSTY SOUTH WINDS WE DID HAVE SOME WIND CHILL
READINGS IN THE TEENS BELOW ZERO. SOME SCATTERED SNOW
SHOWERS/FLURRIES WERE FOUND ACROSS THE FAR NORTH SHORE OF LAKE
SUPERIOR AS SOUTHERLY WINDS HAVE SHIFTED LAKE EFFECT SNOW SHOWERS
ONTO THAT SECTION OF THE NORTH SHORE.
THE MAIN FOCUS FOR TODAY IS DAYTIME HIGHS AND CHANCE OF LIGHT
SNOW. THE NAM CONTINUES TO INDICATE THE POTENTIAL FOR SOME LIGHT
SNOW SPREADING INTO EC MN AND NW WI AS THE DAY WEARS ON. THE
LATEST 06Z RUN HAS SHIFTED THE BAND A BIT SOUTH...GENERALLY INTO
OUR SOUTHERN WI ZONES. MODEL QPF WOULD SUPPORT AN INCH OR SO OF
SNOW IN A RELATIVELY NARROW CORRIDOR. STILL...THE HRRR AND THE 4KM
NMM WRF DO NOT SUPPORT MUCH IN THE WAY OF PRECIPITATION ACROSS
THAT AREA THIS AFTERNOON. WITH THE ECMWF AND GFS ALSO LOOKING
REASONABLY DRY...HAVE OPTED TO ONLY HAVE CHANCE POPS ACROSS NW WI
TODAY. ACROSS THE REMAINDER OF THE AREA...WILL CARRY CHANCE/SCT
POPS ACROSS THE FAR NORTH SHORE...AND SCATTERED FLURRIES ELSEWHERE.
THE CLOUDS AND FLURRIES WILL LINGER INTO TONIGHT...AS A WEAK
TROUGH MOVES ACROSS THE REGION. BROUGHT OVERNIGHT LOWS UP A BIT AS
WINDS AND CLOUDS WILL HELP TO KEEP TEMPS UP.
HIGHS TODAY AND WEDNESDAY ARE EXPECTED TO RANGE FROM THE TEENS TO
AROUND 20. SHOULD BE A GOOD DEAL OF SUNSHINE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
THE EXTENDED PERIOD CONTINUES TO LOOK RELATIVELY QUIET WITH A
WARMING TREND.
THE UPPER FLOW WILL BE QUASI ZONAL THROUGH MOST OF THE PERIOD WITH A
COUPLE SHORTWAVES FORECAST TO PASS THROUGH/NEAR THE NORTHLAND.
HIGH PRESSURE OVER THE AREA WEDNESDAY NIGHT WILL MOVE EAST
THURSDAY...BUT MAINLY DRY CONDITIONS. WE DROPPED THE MENTION OF
FLURRIES FOR MOST AREAS ON THURSDAY AS FORCING LOOKS RATHER WEAK AND
SOUNDINGS DRY. THERE STILL MAY BE SOME LIGHT SNOW/FLURRIES ALONG
PORTIONS OF THE NORTH SHORE DUE TO SOUTHERLY WINDS LEADING TO SOME
LAKE SNOW SNOW. DELTA-T VALUES ARE NOT THAT HIGH...SO ANY
ACCUMULATION SHOULD BE LIGHT.
A SHORTWAVE WILL SLIDE ALONG THE INTERNATIONAL BORDER THURSDAY NIGHT
INTO FRIDAY. WE LEFT THE FORECAST DRY AS THIS WAVE BRUSHES THE
REGION. SOUNDINGS SHOW DRY LOW-MID LEVELS. WE MAY NEED TO ADD A POP
OR FLURRIES IF MORE MOISTURE MAKES IT INTO THE AREA.
A STRONGER CLIPPER SYSTEM WILL BRING A CHANCE FOR SNOW OR A WINTRY
MIXTURE TO PORTIONS OF THE REGION SUNDAY/SUNDAY NIGHT. AT THIS
TIME...PRECIP AMOUNTS LOOK TO BE LIGHT.
HIGH TEMPERATURES ARE EXPECTED TO BE IN THE LOWER TO MIDDLE TWENTIES
THURSDAY...THEN WARM INTO THE UPPER TWENTIES TO LOWER THIRTIES ON
SUNDAY. TEMPS WILL COOL SEVERAL DEGREES MONDAY AS COOLER AIR MOVES
IN BEHIND THE DEPARTING CLIPPER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 539 AM CST TUE DEC 2 2014
VFR CONDITIONS WERE OCCURRING ACROSS THE NORTHLAND THIS MORNING
WITH MID TO UPPER LEVEL CLOUDS OVERHEAD. A TROUGH OF LOW PRESSURE
WILL MOVE THROUGH THE AREA TODAY BRINGING A CHANCE FOR LIGHT
SNOW/FLURRIES TO MAINLY THE KHYR AREA. A PERIOD OF MVFR CEILINGS
WILL BE POSSIBLE FOR MOST AREAS LATER THIS AFTERNOON INTO THE
EVENING. MORE MVFR CEILINGS WILL MOVE INTO WESTERN AREAS LATE IN
THE PERIOD.
GUSTY SOUTHERLY WINDS WILL DIMINISH TODAY AND GRADUALLY VEER TO W/SW.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 17 5 16 3 / 20 10 0 0
INL 12 0 10 -9 / 20 10 10 0
BRD 18 5 16 3 / 20 10 0 0
HYR 20 5 18 0 / 30 20 0 0
ASX 21 9 18 3 / 30 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...DAP
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
356 AM CST TUE DEC 2 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
AT 330 AM...CLOUDS WERE GRADUALLY INCREASING/THICKENING ACROSS THE
NORTHLAND. TEMPS WERE GENERALLY IN THE SINGLE DIGITS ABOVE
ZERO...BUT WITH GUSTY SOUTH WINDS WE DID HAVE SOME WIND CHILL
READINGS IN THE TEENS BELOW ZERO. SOME SCATTERED SNOW
SHOWERS/FLURRIES WERE FOUND ACROSS THE FAR NORTH SHORE OF LAKE
SUPERIOR AS SOUTHERLY WINDS HAVE SHIFTED LAKE EFFECT SNOW SHOWERS
ONTO THAT SECTION OF THE NORTH SHORE.
THE MAIN FOCUS FOR TODAY IS DAYTIME HIGHS AND CHANCE OF LIGHT
SNOW. THE NAM CONTINUES TO INDICATE THE POTENTIAL FOR SOME LIGHT
SNOW SPREADING INTO EC MN AND NW WI AS THE DAY WEARS ON. THE
LATEST 06Z RUN HAS SHIFTED THE BAND A BIT SOUTH...GENERALLY INTO
OUR SOUTHERN WI ZONES. MODEL QPF WOULD SUPPORT AN INCH OR SO OF
SNOW IN A RELATIVELY NARROW CORRIDOR. STILL...THE HRRR AND THE 4KM
NMM WRF DO NOT SUPPORT MUCH IN THE WAY OF PRECIPITATION ACROSS
THAT AREA THIS AFTERNOON. WITH THE ECMWF AND GFS ALSO LOOKING
REASONABLY DRY...HAVE OPTED TO ONLY HAVE CHANCE POPS ACROSS NW WI
TODAY. ACROSS THE REMAINDER OF THE AREA...WILL CARRY CHANCE/SCT
POPS ACROSS THE FAR NORTH SHORE...AND SCATTERED FLURRIES ELSEWHERE.
THE CLOUDS AND FLURRIES WILL LINGER INTO TONIGHT...AS A WEAK
TROUGH MOVES ACROSS THE REGION. BROUGHT OVERNIGHT LOWS UP A BIT AS
WINDS AND CLOUDS WILL HELP TO KEEP TEMPS UP.
HIGHS TODAY AND WEDNESDAY ARE EXPECTED TO RANGE FROM THE TEENS TO
AROUND 20. SHOULD BE A GOOD DEAL OF SUNSHINE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM CST TUE DEC 2 2014
THE EXTENDED PERIOD CONTINUES TO LOOK RELATIVELY QUIET WITH A
WARMING TREND.
THE UPPER FLOW WILL BE QUASI ZONAL THROUGH MOST OF THE PERIOD WITH A
COUPLE SHORTWAVES FORECAST TO PASS THROUGH/NEAR THE NORTHLAND.
HIGH PRESSURE OVER THE AREA WEDNESDAY NIGHT WILL MOVE EAST
THURSDAY...BUT MAINLY DRY CONDITIONS. WE DROPPED THE MENTION OF
FLURRIES FOR MOST AREAS ON THURSDAY AS FORCING LOOKS RATHER WEAK AND
SOUNDINGS DRY. THERE STILL MAY BE SOME LIGHT SNOW/FLURRIES ALONG
PORTIONS OF THE NORTH SHORE DUE TO SOUTHERLY WINDS LEADING TO SOME
LAKE SNOW SNOW. DELTA-T VALUES ARE NOT THAT HIGH...SO ANY
ACCUMULATION SHOULD BE LIGHT.
A SHORTWAVE WILL SLIDE ALONG THE INTERNATIONAL BORDER THURSDAY NIGHT
INTO FRIDAY. WE LEFT THE FORECAST DRY AS THIS WAVE BRUSHES THE
REGION. SOUNDINGS SHOW DRY LOW-MID LEVELS. WE MAY NEED TO ADD A POP
OR FLURRIES IF MORE MOISTURE MAKES IT INTO THE AREA.
A STRONGER CLIPPER SYSTEM WILL BRING A CHANCE FOR SNOW OR A WINTRY
MIXTURE TO PORTIONS OF THE REGION SUNDAY/SUNDAY NIGHT. AT THIS
TIME...PRECIP AMOUNTS LOOK TO BE LIGHT.
HIGH TEMPERATURES ARE EXPECTED TO BE IN THE LOWER TO MIDDLE TWENTIES
THURSDAY...THEN WARM INTO THE UPPER TWENTIES TO LOWER THIRTIES ON
SUNDAY. TEMPS WILL COOL SEVERAL DEGREES MONDAY AS COOLER AIR MOVES
IN BEHIND THE DEPARTING CLIPPER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1126 PM CST MON DEC 1 2014
VFR EXPECTED UNTIL 15Z WHEN SOME LIGHT SNOW/FLURRIES ARE FORECAST.
WITH THIS PCPN...MVFR IS ANTICIPATED. LLWS IS POSSIBLE THROUGH
ABOUT 09Z AS LLJ PASSES NEARBY. EXPECT AN IMPROVEMENT TO VFR AFTER
00Z EXCEPT IN THE VCNTY OF HYR WHERE MVFR CIGS WILL LINGER.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 17 5 16 3 / 20 10 0 0
INL 12 0 10 -9 / 20 10 10 0
BRD 18 5 16 3 / 20 10 0 0
HYR 20 5 18 0 / 30 20 0 0
ASX 21 9 18 3 / 30 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...DAP
LONG TERM...MELDE
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1123 PM MST MON DEC 1 2014
.UPDATE...
PER INCREASING LOW LEVEL FRONTOGENESIS AS WEAK COLD FRONT SPILLS
IN FROM THE NW...WE ARE SEEING SOME BANDED SNOW SHOWERS DEVELOP
ACROSS OUR LOWER ELEVATIONS INCLUDING THE BILLINGS AREA. HAVE
ADJUSTED POPS OVERNIGHT TO ACCOUNT FOR THIS. ANY ACCUMS WILL NOT
AMT TO MUCH AS PCPN SHOULD STAY GENERALLY LIGHT. PCPN WILL TAPER
OFF LATE TONIGHT/EARLY TUESDAY AS SHORTWAVE PASSES. JKL
&&
.SHORT TERM...VALID FOR TUE AND WED...
SURFACE TROUGH OVER CENTRAL ZONES PULLING EAST WITH TEMPERATURES
CLIMBING THROUGH THE 20S IN MOST LOCATIONS WITH A FEW EXCEPTIONS.
HIGHER ELEVATIONS ARE THE WARM SPOTS WITH AREAS WITH TIMBERCREST
RAWS AT 40 WHILE A FEW SHELTERED LOCATIONS LIKE LITTLE BIG HORN
ARE STILL IN SINGLE DIGITS. THIS DEPARTURE OF THE ARCTIC LOOKS TO
BE PERMANENT AS SPEEDY CYCLONIC FLOW ALOFT WILL BRING A SERIES OF
WEAK PACIFIC SYSTEMS ACROSS THE AREA.
WATER VAPOR SHOWS DRY AIR GETTING DRAGGED INTO THE AREA AHEAD OF
THE CYCLONIC FLOW IS LIMITING THE NORTHWARD PROGRESS OF MOISTURE
THAT IS BEING PUSHED OUT OF THE EASTERN PACIFIC BY A LOW OFF THE
CALIFORNIA COAST. THIS MOISTURE IS STREAMING INTO IDAHO AND
SOUTHWEST MONTANA AND COOKE CITY CAMS DO SHOW SOME SNOW BUT
DEWPOINTS IN THE TEENS AT DERBY MOUNTAIN AND TIMBERCREST SHOW THIS
IS ONLY IMPACTING THE BACKSIDE OF THE BEARTOOTHS AND THE
ABSAROKAS. RUC CONSISTENTLY HOLDING THIS SNOW OUT OF THE LOWER
ELEVATIONS BUT DO HAVE 4 TO 8 INCH MOUNTAIN ACCUMULATIONS EXPECTED
OVERNIGHT.
AS AXIS OF CYCLONIC FLOW SHIFTS THROUGH THE REGION TONIGHT IT DOES
ALLOW THE SURFACE TROUGH TO PULL EASTWARD AS A WEAK FRONT. HIGH
PRESSURE BEHIND THIS FRONT IS VERY LIMITED AS IT IS NOT A STRONG
AIRMASS CHANGE SO TONIGHTS TEMPERATURES WILL BE MUCH WARMER
TONIGHT THAN PREVIOUS NIGHT. THERE IS A WINDOW OF SOME GAP FLOW
WINDS IN THE LIVINGSTON AREA THIS EVENING BUT THEY WILL WANE AS
THE BOUNDARY SHIFTS SOUTH OF THE AREA.
TUESDAY ANOTHER BOUNDARY SHIFTS ACROSS THE AREA WITH A BETTER
POCKET OF HIGH PRESSURE BEHIND IT. THIS SETS UP A BREEZY DAY WITH
NORTHWEST WINDS SO DESPITE A MUCH WARMER START TEMPERATURES WILL
NOT CLIMB PAST THE 30S. HIGH RISES KICKING IN TUESDAY NIGHT
STRENGTHEN THIS HIGH AS IT MOVES INTO EASTERN MONTANA SO SURFACE
FLOW BECOMES LIGHT AND RADIATIONAL COOLING WILL BRING A SHOT AT
SINGLE DIGIT TEMPERATURES ACROSS THE EASTERN HALF OF THE AREA.
WEDNESDAY AN UPPER LEVEL RIDGE AXIS THAT HAS A BUNCH OF ENERGY
FLOWING THROUGH IT CAUSES HEIGHTS TO RISE OVER THE AREA. THIS
SUPPORTS ANOTHER BIT OF MODERATION WITH CONTINUED DRY WEATHER.
BORSUM
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
MINIMAL CHANGES THROUGH THE LONG TERM PERIOD...WITH GENERALLY
QUIET WEATHER THROUGHOUT THE PERIOD. MODELS REMAIN IN PRETTY GOOD
AGREEMENT THROUGH EARLY SATURDAY...WHERE MODELS BEGIN TO DIVERGE.
A DIRTY RIDGE DEVELOPS OVER IDAHO AND WESTERN MONTANA BY
THURSDAY...WITH A GOOD TAP PACIFIC MOISTURE STREAMING INTO THE
WESTERN MOUNTAINS. A STRONGER WAVE WILL ROTATE THROUGH
THURSDAY...GIVING A CHANCE FOR POPS INTO THE FOOTHILLS AND NEAR
WESTERN PLAINS...BUT STILL NOT EXPECTING SIGNIFICANT
ACCUMULATIONS OTHER THAN THE MOUNTAINS.
SHORTWAVE RIDGING BUILDS IN FOR FRIDAY INTO SATURDAY...POINTING TO
A MORE SIGNIFICANT WARM UP...AND DRY WEATHER. MODELS INDICATE
A STRONGER PACIFIC SYSTEM PUSHING INTO THE REGION SATURDAY
NIGHT...BUT DIFFER ON STRENGTH OF THE WAVE AND AMOUNT OF MOISTURE.
GFS SWEEPS THE WAVE ACROSS THE REGION BRINGING A CHANCE FOR PRECIP
ACROSS THE AREA THROUGH SUNDAY...WHILE EC BRINGS WEAKER WAVE...AND
SHIFT BULK OF MOISTURE TO THE NORTH. HAVE INTRODUCED SLIGHT POPS
FOR THE SATURDAY NIGHT PERIOD...BUT ONLY PLACEHOLDER...FLURRY
TYPE...POPS IN FOR SUNDAY AT THIS POINT. THE RIDGE APPEARS TO
REDEVELOP OVERNIGHT SUNDAY NIGHT...AND GENERALLY PERSISTS THROUGH
THE END OF THE PERIOD.
TEMPS IN 40S CAN BE EXPECTED THROUGHOUT THE EXTENDED
PERIOD...PEAKING WITH HIGHS NEAR 50 FOR FRIDAY AND SATURDAY. AAG
&&
.AVIATION...
SOUTHWEST WINDS GUSTING UP TO 25-40 KTS WILL AFFECT KLVM
OVERNIGHT AND INTO TUESDAY. LOOK FOR SNOW SHOWERS OVER THE HIGH
COUNTRY WITH THE BEARTOOTH MOUNTAINS OFTEN OBSCURED. MAINLY VFR
CONDITIONS CAN OTHERWISE BE EXPECTED THROUGH TONIGHT ACROSS MUCH
OF THE REGION. SCATTERED SNOW WILL MOVE INTO THE BIG HORNS REGION
EARLY TUESDAY OBSCURING THE HIGHER ELEVATIONS. THERE IS A SLIGHT
THREAT OF MVFR CONDITIONS IN THE KSHR VICINITY AFTER 10Z...BUT
PLAN TO KEEP THIS OUT OF OF THE KSHR TAF FOR NOW. BT
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 019/034 010/033 019/045 027/048 027/050 025/043 025/042
21/B 00/B 12/W 11/B 00/B 21/B 00/B
LVM 030/037 014/040 029/045 029/046 028/050 025/044 027/041
21/B 01/B 13/W 22/W 11/B 21/B 11/B
HDN 016/034 006/033 015/044 022/046 022/050 021/043 021/043
21/B 00/B 12/J 11/B 00/B 21/M 00/B
MLS 008/027 002/029 009/038 016/041 019/044 019/039 018/039
20/B 00/B 01/B 11/B 00/B 11/M 00/B
4BQ 013/033 005/034 014/042 018/044 022/044 020/041 020/039
21/B 00/B 01/B 11/U 00/B 11/M 00/B
BHK 006/025 004/028 011/035 015/040 019/040 018/035 016/036
21/B 00/U 01/B 00/B 00/B 11/M 00/B
SHR 013/036 010/038 021/045 023/046 021/049 020/044 022/042
22/J 00/B 12/W 11/B 00/B 22/W 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1159 AM CST TUE DEC 2 2014
.UPDATE...
ISSUED AT 1149 AM CST TUE DEC 2 2014
UPDATED THE FORECAST TO INCREASE TEMPERATURES. WE SHOULD GET A
FAIR AMOUNT OF COMPRESSIONAL WARMING AHEAD OF AN APPROACHING COLD
FRONT. THE COLD FRONT IS AT OUR CWA DOORSTEP AND WILL SLIDE
SOUTHEAST. EVEN BEHIND THE COLD FRONT...COLD AIR ADVECTION IS NOT
STRONG...AND MIXING ALONG WITH DOWNSLOPE SHOULD
COMPENSATE...KEEPING TEMPERATURES QUITE A BIT WARMER THAN
ORIGINALLY EXPECTED. THE HRRR SEEMS TO BE HANDLING LATEST TRENDS
WELL. I ALSO INCREASED WIND...ESPECIALLY GUSTS. WIND SHOULD
DIMINISH JUST AHEAD OF THE FRONT...BUT WILL PICK UP AGAIN IN OUR
NORTHWESTERN CWA BY LATE AFTERNOON BEHIND THE FRONT. WE COULD GET
NEAR CRITICAL FIRE DANGER TODAY DUE TO WIND AND LOW HUMIDITY. OUR
EAST/SOUTHEAST IS THE BIGGEST CONCERN (ESPECIALLY NEAR HEBRON)...AS
DEWOINTS RECOVER SLOWER THERE...ALONG WITH TAKING LONGER FOR WIND
TO DIMINISH AHEAD OF THE COLD FRONT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CST TUE DEC 2 2014
ITS BEEN ANOTHER NIGHT OF QUIET CONDITIONS ACROSS THE PLAINS
TONIGHT...WITH CONTINUED ZONAL FLOW IN PLACE IN THE UPPER LEVELS.
SATELLITE IMAGERY SHOWS A BROAD SHORTWAVE TROUGH CURRENTLY MAKING
ITS WAY EAST OUT OF THE NRN ROCKIES...AND THIS SYSTEM WILL HAVE AN
IMPACT ON OUR CWA LATER TODAY. AT THE SFC...A TROUGH OF LOW
PRESSURE IS DRAPED ALONG THE HIGH PLAINS...WITH A RIDGE AXIS
EXTENDING FROM OVER THE OK/TX BORDER NORTHEAST TO THE PARENT HIGH
OVER THE NERN CONUS. THIS HAS RESULTED IN CONTINUED
SOUTH/SOUTHWESTERLY WINDS OVERNIGHT...WHICH AT TIMES HAS BEEN
GUSTY...MAINLY OVER THE NRN HALF OF THE CWA. SKIES ARE MOSTLY
CLEAR/PARTLY CLOUDY...AND TEMPS AS OF 3 AM RANGE FROM THE LOWER
TEENS TO LOWER 20S.
THE FORECAST THOUGH THE SHORT TERM PERIOD TODAY/TONIGHT REMAINS A
DRY ONE...EVEN WITH A DISTURBANCE AFFECTING THE REGION. MODELS
CONTINUE TO SHOW THERE BEING AN OVERALL LACK OF MOISTURE WITH ITS
PASSAGE. THE ABOVE MENTIONED BROAD TROUGH WILL CONTINUE TO PUSH
EAST TODAY...MAINLY AFFECTING THE NRN/CENTRAL PLAINS...BEFORE
EXITING TO THE EAST THIS EVENING.
THE ONE NOTABLE AFFECT THIS SYSTEM WILL HAVE IS WITH ITS
ACCOMPANYING SURFACE COLD FRONT. CURRENTLY OFF TO THE N/NW OF THE
CWA...MODEL TIMING REMAINS IN PRETTY GOOD AGREEMENT...WITH THE
FRONT STARTING TO CREEP INTO NWRN PORTIONS OF THE CWA BY MIDDAY.
THERE ISNT A STRONG PUSH BEHIND THIS FRONT...AND MODELS SHOW BY
00Z THIS EVENING IT HASNT QUITE CLEARED THE SERN THIRD OR SO OF
THE CWA. A DAYTIME FRONTAL PASSAGE MAKES THE TEMPERATURE FORECAST
TRICKY...AND TODAY IS NO EXCEPTION. THERE ARE SOME NOTABLE
DIFFERENCES BETWEEN MODELS/GUIDANCE...ESP WITH THE RAP/HRRR. THERE
IS A WARMER AIRMASS IN PLACE ALOFT...AND EXPECTING THAT RIGHT
AHEAD OF THE FRONTAL PASSAGE THERE WILL BE BUMPS UP IN TEMPS AS
MIXING INCREASES AND CAN TAP INTO THAT WARMER AIR. THIS LOOKS TO
MAIN AFFECT THE NRN/WRN PORTIONS OF THE CWA...DUE TO THE TIMING OF
THE FRONTAL PASSAGE...LOCATIONS FURTHER SOUTH LIKELY WONT SEE THAT
FRONT MOVE IN UNTIL LATER IN THE AFTERNOON...AND IT LOOKS TO HAVE
LOST SOME OF ITS PUSH BY THEN. GOING STRAIGHT RAP/HRRR WOULD GIVE
HIGH TEMPS IN THE LOWER 60S FOR A NARROW CORRIDOR OF
LOCATIONS...WITH MANY OTHERS WELL INTO THE 50S /AGAIN THIS IS
MAINLY IN NEB/. DID AT LEAST INCORPORATE A BLEND OF THAT IDEA INTO
THE FORECAST...BUT PRETTY HESITANT TO GO AS WARM AS THEY SUGGEST.
CONFIDENCE IN HIGHS IS ON THE LOW SIDE...AND THE CURRENT FORECAST
IS A RANGE FROM THE MID 40S TO MID 50S...DAY SHIFT SHOULD HAVE A
PRETTY GOOD IDEA BY LATE MORNING HOW THINGS ARE GOING TO PLAY OUT
ALONG/AHEAD OF THE SFC FRONT AND MAY HAVE TO MAKE ADJUSTMENTS TO
HIGH TEMPERATURES.
DO HAVE SOME LOWER RH VALUES DEVELOPING ACROSS CENTRAL/SRN
PORTIONS OF THE CWA AT TIMES THIS AFTERNOON...BUT THOSE ARE
DEPENDENT ON THE WARMER TEMPS THE RAP/HRRR ARE SHOWING. EVEN IF
THOSE RH VALUES MATERIALIZE...EXPECTING THEM TO NOT MATCH UP WITH
THE GUSTIER WINDS THAT MAY ACCOMPANY THE FRONTAL PASSAGE...SO WILL
CONTINUE TO LEAVE ANY FIRE WX CONCERNS OUT OF THE HWO BUT WILL
ALSO BE SOMETHING FOR THE DAY SHIFT TO KEEP AN EYE ON IF THINGS
TREND WORSE THAN CURRENTLY FORECAST.
TONIGHT...THE NORTHERLY WINDS SETTLE IN ACROSS THE ENTIRE CWA AS
HIGH PRESSURE AT THE SURFACE STARTS BUILDING IN FROM THE
NW...SPEEDS LOOK TO TOP OUT AROUND 10 MPH. LOWS IN THE MID TEENS
TO LOWER 20S ARE FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM CST TUE DEC 2 2014
PRIMARILY ZONAL FLOW ALOFT IS EXPECTED TO CONTINUE THROUGH THE
EXTENDED PERIODS WITH MULTIPLE WEAK DISTURBANCES FORECAST TO
TRANSITION ACROSS THE ROCKIES...HAVING LITTLE APPRECIABLE IMPACT
ON THE LOCAL WEATHER.
STARTING OFF...WEDNESDAY WILL LIKELY BE THE COOLEST DAY OF THE
EXTENDED PERIODS AS TEMPERATURES WILL BE SLOW TO RECOVER BEHIND
THIS AFTERNOON/EVENINGS COLD FRONT. AS A RESULT...ACTUALLY
TWEAKED DOWN FORECAST HIGH TEMPERATURES A FEW DEGREES AS IF LATEST
GUIDANCE IS CORRECT...WITH COLD AIR ADVECTION CONTINUING THROUGH
THE AFTERNOON HOURS WEDNESDAY...THERE IS THE POTENTIAL FOR SOME
LOCATIONS POSSIBLY NOT CLIMBING ABOVE FREEZING DURING THE
AFTERNOON HOURS. WHILE GUIDANCE IS TRENDING COOLER...DID NOT FEEL
CONFIDENT ENOUGH TO GO QUITE THAT LOW...BUT KEPT MOST LOCATIONS IN
THE 30S.
THEREAFTER...THE LOCAL AIRMASS WILL BEGIN TO MODERATE SOME AS
RETURN FLOW AROUND THE SURFACE HIGH WILL RESULT IN SOUTHERLY
BREEZES...AND WARMER AIR ADVECTING NORTHWARD ACROSS THE LOCAL
AREA...WITH A MORE CLIMATOLOGICALLY NORMAL DAY IS EXPECTED FOR
THURSDAY. AT THE SAME TIME...EXPECT THE REMNANTS OF THE WEST COAST
STORM APPROACHING CENTRAL CALIFORNIA THIS MORNING TO REACH THE
LOCAL AREA...WITH THE BRUNT OF THIS SYSTEM...AS WELL AS THE
SUBSEQUENT SYSTEM...EXPECTED TO REMAIN SOUTH OF THE LOCAL AREA.
WHILE THE MODELS ARE TRENDING FURTHER SOUTH WITH THE WEEKEND
STORM...DECIDED TO KEEP SMALL CHANCES FOR PRECIP IN THE FORECAST
ANYHOW...MAINLY ACROSS KANSAS...ALBEIT WITH THE CURRENT TRENDS WE
VERY WELL MAY END UP BEING DRY THROUGH THE ENTIRE EXTENDED
FORECAST PERIODS.
OVERALL...EXPECT A FAIRLY QUIET PATTERN THROUGH THE UPCOMING
WEEKEND...WITH A COOL START TO THE EXTENDED PERIODS
WEDNESDAY...AND MODERATING TEMPERATURES THROUGH THE REMAINDER OF
THE EXTENDED RESULTING IN TEMPERATURES RETURNING TO NEAR OR JUST
ABOVE CLIMATOLOGY.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1149 AM CST TUE DEC 2 2014
WIND WILL BE A BIT TRICKY TODAY. GUSTY WIND FROM THE SOUTHWEST
WILL CONTINUE UNTIL A COLD FRONT APPROACHES...AND THEN THE WIND
WILL DIMINISH. THE WIND WILL CHANGE DIRECTION TO THE NORTHWEST BY
EVENING...BUT BY THEN...WIND WILL HAVE DIMINISHED BEHIND THE FRONT
AFTER SUNSET. WE COULD GET SOME MID-LEVEL PATCHY SKY COVER FOR A
FEW HOURS THIS AFTERNOON...AND AGAIN BY LATE MORNING WEDNESDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...ADP
LONG TERM...ROSSI
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1039 PM EST WED DEC 3 2014
.SYNOPSIS...A COLD FRONT WILL CROSS THE AREA OVERNIGHT. SURFACE HIGH
PRESSURE WILL BUILD IN... WHILE UPPER LEVEL DISTURBANCE MOVE ACROSS
THE AREA THURSDAY AND FRIDAY.
&&
.NEAR TERM /TONIGHT THROUGH THURSDAY NIGHT/...
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 /00Z 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...
NONE.
&&
$$
SYNOPSIS...SEC/DJF
NEAR TERM...SEC/DJF
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
643 PM EST WED DEC 3 2014
.SYNOPSIS...A COLD FRONT MOVES THROUGH CENTRAL NORTH CAROLINA
TONIGHT. SURFACE HIGH PRESSURE BUILDS OVER THE MID-ATLANTIC AND THE
CAROLINAS FOR THURSDAY AND FRIDAY...WHILE UPPER-LEVEL DISTURBANCES
MOVE OVER OR NEAR THE AREA. ANOTHER COLD FRONT MOVES THROUGH THE
REGION SATURDAY.
&&
.NEAR TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 310 PM WEDNESDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE SURFACE FRONT STILL WEDGED
AGAINST THE MOUNTAINS...BUT OVERNIGHT ALL OF THE GUIDANCE SUGGESTS
THIS FRONT WILL PUSH THROUGH CENTRAL NORTH CAROLINA. THE LATEST
VISIBLE IMAGE SHOWS SINCE 1815Z TO 19Z A RAPID INCREASE IN THINNING
AND/OR CLEAR PATCHES AND THIS TREND IS EXPECTED TO CONTINUE THROUGH
THE REST OF THE AFTERNOON INTO THE EVENING...PARTICULARLY AS THE
OROGRAPHIC CIRRUS ON INFRARED IMAGERY HAS STARTED TO DIMINISH OVER
THE MOUNTAINS FROM SOUTH TO NORTH. MORE DIFFICULT IS THE TREND OF
CONDITIONS OVERNIGHT...BASED ON THE BUFR SOUNDINGS...MOS GUIDANCE...
AND HRRR WRF OUTPUT.
WITH THE FRONT STILL TO THE NORTHWEST...AND WITH EROSION OF LOW
CLOUDS ONGOING BUT WITH DEW POINTS STILL HIGH...THINK THERE IS THE
POTENTIAL FOR FOG AND/OR LOW CLOUDS WITH THE GREATEST CHANCE OF THIS
ALONG AND SOUTH OF ABOUT U.S. 64 WHERE DEW POINTS ARE WELL INTO THE
50S. NEITHER THE SREF ENSEMBLE VISIBILITY GUIDANCE NOR THE HRRR WRF
SHOW THIS...BUT THE PATTERN SEEMS TO FIT AND IS NOTED BY THE
MAJORITY OF THE MOS GUIDANCE. AS SUCH...NOTED PATCHY FOG FOR PART OF
THE NIGHT IN THAT AREA. OTHERWISE...UNDER AN AVERAGE PARTLY CLOUDY
SKY...WITH SOME CLEAR PATCHES AT TIMES ESPECIALLY NORTH AND MORE
AREAS OF LOWER CLOUDS AND FOG POSSIBLE SOUTH...OVERNIGHT LOWS FROM
NEAR THE MID 30S TOWARD KTDF TO NEAR 45 IN THE FAR 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 /00Z 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...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
207 PM CST TUE DEC 2 2014
.UPDATE...
ISSUED AT 207 PM CST TUE DEC 2 2014
DID INCREASE AFTERNOON TEMPERATURES SOUTHWEST AND INTO THE SOUTH
CENTRAL WHERE THE SNOW PACK IS THINNER. OTHERWISE...THE FORECAST
IS ON TRACK.
UPDATE ISSUED AT 933 AM CST TUE DEC 2 2014
ON GOING FORECAST IS ON TRACK WITH WEAK HIGH PRESSURE IN PLACE. NO
CHANGES NEEDED OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 15
UTC.
UPDATE ISSUED AT 636 AM CST TUE DEC 2 2014
NO MAJOR UPDATES WERE NEEDED TO THE ONGOING FORECAST. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE FRESHENED UP PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CST TUE DEC 2 2014
RELATIVELY QUIET WEATHER WITH CONTINUED BELOW NORMAL TEMPERATURES
WILL BE THE MAIN HIGHLIGHTS IN THE SHORT TERM PERIOD.
CURRENTLY...LONG WAVE TROUGH AXIS SWINGING EAST INTO THE NORTHERN
PLAINS THIS MORNING...WITH AN EMBEDDED S/WV AT THE BASE OF THE
TROUGH MOVING EAST-SOUTHEAST ACROSS NORTH DAKOTA. THIS FEATURE IS
INTERACTING WITH A SOUTHWARD RETREATING FRONTAL BOUNDARY STRETCHED
WEST TO EAST ACROSS SOUTHEASTERN MONTANA INTO NORTHERN SOUTH
DAKOTA...RESULTING IN WEAK RADAR RETURNS ALONG TO NORTH OF THIS
BOUNDARY INCLUDING OVER MY SOUTHWESTERN COUNTIES. CIGS LOWERING
FROM 4-6K AGL SO POSSIBLE SOME LIGHT SNOW IS FALLING. OBSERVING
SITES THOUGH HAVE NOT REPORTED ANYTHING AND HAVE NOT SEEN ANYTHING
ON AREA WEBCAMS THUS FAR. STILL...WITH THE CIGS THIS LOW WILL
CONTINUE TO MENTION A SLIGHT CHANCE FOR LIGHT SNOW THIS
AM...LEANING ON THE LATEST HRRR OUTPUT. ZERO IMPACTS.
WEAK CAA BEHIND THE BOUNDARY AND IN THE WAKE OF THE UPPER TROUGH
TODAY INTO TONIGHT. DAYTIME HIGHS WILL BE WARMER SOME LOCATIONS
BUT REMAIN COLD RANGING FROM 10 ABOVE NEAR THE TURTLE MOUNTAINS TO
THE MID/UPPER 20S SOUTHWEST INTO FAR SOUTH CENTRAL. MOST MODELS
ARE INDICATING SOME LIGHT QPF WITH THE CAA TODAY OVER MY
NORTH...WHICH WAS ADDED INTO THE FORECAST LAST EVENING...SO SEE
NO REASON TO REMOVE.
MAINLY DRY WITH DECREASING CLOUDS TONIGHT AS SURFACE HIGH PRESSURE
BUILDS EASTWARD INTO THE DAKOTAS. LOWS GENERALLY 5 ABOVE TO 5
BELOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 309 AM CST TUE DEC 2 2014
BROAD PACIFIC RIDGING BUILDING OVER THE WESTERN CONUS WILL LEAD
TO MAINLY DRY CONDITIONS AND A WARMING TREND TO ABOVE NORMAL
TEMPERATURES BY THE END OF THE WEEK.
THE MEDIUM RANGE MODELS DIFFER WITH RESPECT TO THE TIMING AND
POSITION OF A SHORTWAVE POTENTIALLY AFFECTING NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. THE LATEST GEM/ECMWF ARE MORE
PROGRESSIVE AND FARTHER NORTH WITH THIS FEATURE...WHEREAS THE GFS
IS SLOWER AND FARTHER SOUTH. FOR NOW WILL SIDE WITH THE CONSENSUS
SOLUTIONS AND KEEP THE MENTION OF SNOW CHANCES NEAR THE TURTLE
MOUNTAIN REGION SUNDAY.
COOLER AIR IS THEN FORECAST TO FILTER IN BEHIND THE SHORTWAVE WITH
BELOW NORMAL TEMPERATURES EXPECTED MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 205 PM CST TUE DEC 2 2014
GENERALLY VFR CONDITIONS FOR THE PERIOD WITH HIGH PRESSURE IN
PLACE. MVFR STRATUS MAY CLIP KISN/KMOT THIS EVENING INTO TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...NH
LONG TERM...TM
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
933 AM CST TUE DEC 2 2014
.UPDATE...
ISSUED AT 933 AM CST TUE DEC 2 2014
ON GOING FORECAST IS ON TRACK WITH WEAK HIGH PRESSURE IN PLACE. NO
CHANGES NEEDED OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 15
UTC.
UPDATE ISSUED AT 636 AM CST TUE DEC 2 2014
NO MAJOR UPDATES WERE NEEDED TO THE ONGOING FORECAST. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE FRESHENED UP PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CST TUE DEC 2 2014
RELATIVELY QUIET WEATHER WITH CONTINUED BELOW NORMAL TEMPERATURES
WILL BE THE MAIN HIGHLIGHTS IN THE SHORT TERM PERIOD.
CURRENTLY...LONG WAVE TROUGH AXIS SWINGING EAST INTO THE NORTHERN
PLAINS THIS MORNING...WITH AN EMBEDDED S/WV AT THE BASE OF THE
TROUGH MOVING EAST-SOUTHEAST ACROSS NORTH DAKOTA. THIS FEATURE IS
INTERACTING WITH A SOUTHWARD RETREATING FRONTAL BOUNDARY STRETCHED
WEST TO EAST ACROSS SOUTHEASTERN MONTANA INTO NORTHERN SOUTH
DAKOTA...RESULTING IN WEAK RADAR RETURNS ALONG TO NORTH OF THIS
BOUNDARY INCLUDING OVER MY SOUTHWESTERN COUNTIES. CIGS LOWERING
FROM 4-6K AGL SO POSSIBLE SOME LIGHT SNOW IS FALLING. OBSERVING
SITES THOUGH HAVE NOT REPORTED ANYTHING AND HAVE NOT SEEN ANYTHING
ON AREA WEBCAMS THUS FAR. STILL...WITH THE CIGS THIS LOW WILL
CONTINUE TO MENTION A SLIGHT CHANCE FOR LIGHT SNOW THIS
AM...LEANING ON THE LATEST HRRR OUTPUT. ZERO IMPACTS.
WEAK CAA BEHIND THE BOUNDARY AND IN THE WAKE OF THE UPPER TROUGH
TODAY INTO TONIGHT. DAYTIME HIGHS WILL BE WARMER SOME LOCATIONS
BUT REMAIN COLD RANGING FROM 10 ABOVE NEAR THE TURTLE MOUNTAINS TO
THE MID/UPPER 20S SOUTHWEST INTO FAR SOUTH CENTRAL. MOST MODELS
ARE INDICATING SOME LIGHT QPF WITH THE CAA TODAY OVER MY
NORTH...WHICH WAS ADDED INTO THE FORECAST LAST EVENING...SO SEE
NO REASON TO REMOVE.
MAINLY DRY WITH DECREASING CLOUDS TONIGHT AS SURFACE HIGH PRESSURE
BUILDS EASTWARD INTO THE DAKOTAS. LOWS GENERALLY 5 ABOVE TO 5
BELOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 309 AM CST TUE DEC 2 2014
BROAD PACIFIC RIDGING BUILDING OVER THE WESTERN CONUS WILL LEAD
TO MAINLY DRY CONDITIONS AND A WARMING TREND TO ABOVE NORMAL
TEMPERATURES BY THE END OF THE WEEK.
THE MEDIUM RANGE MODELS DIFFER WITH RESPECT TO THE TIMING AND
POSITION OF A SHORTWAVE POTENTIALLY AFFECTING NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. THE LATEST GEM/ECMWF ARE MORE
PROGRESSIVE AND FARTHER NORTH WITH THIS FEATURE...WHEREAS THE GFS
IS SLOWER AND FARTHER SOUTH. FOR NOW WILL SIDE WITH THE CONSENSUS
SOLUTIONS AND KEEP THE MENTION OF SNOW CHANCES NEAR THE TURTLE
MOUNTAIN REGION SUNDAY.
COOLER AIR IS THEN FORECAST TO FILTER IN BEHIND THE SHORTWAVE WITH
BELOW NORMAL TEMPERATURES EXPECTED MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY)
ISSUED AT 930 AM CST TUE DEC 2 2014
A WEAK SURFACE COLD FRONT WILL MOVE ACROSS EASTERN NORTH DAKOTA
INTO NORTHWEST MINNESOTA THIS MORNING. VFR CONDITIONS EXPECTED AT
ALL TAF SITES THROUGH THE 12Z PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...NH
LONG TERM...TM
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
637 AM CST TUE DEC 2 2014
.UPDATE...
ISSUED AT 636 AM CST TUE DEC 2 2014
NO MAJOR UPDATES WERE NEEDED TO THE ONGOING FORECAST. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE FRESHENED UP PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CST TUE DEC 2 2014
RELATIVELY QUIET WEATHER WITH CONTINUED BELOW NORMAL TEMPERATURES
WILL BE THE MAIN HIGHLIGHTS IN THE SHORT TERM PERIOD.
CURRENTLY...LONG WAVE TROUGH AXIS SWINGING EAST INTO THE NORTHERN
PLAINS THIS MORNING...WITH AN EMBEDDED S/WV AT THE BASE OF THE
TROUGH MOVING EAST-SOUTHEAST ACROSS NORTH DAKOTA. THIS FEATURE IS
INTERACTING WITH A SOUTHWARD RETREATING FRONTAL BOUNDARY STRETCHED
WEST TO EAST ACROSS SOUTHEASTERN MONTANA INTO NORTHERN SOUTH
DAKOTA...RESULTING IN WEAK RADAR RETURNS ALONG TO NORTH OF THIS
BOUNDARY INCLUDING OVER MY SOUTHWESTERN COUNTIES. CIGS LOWERING
FROM 4-6K AGL SO POSSIBLE SOME LIGHT SNOW IS FALLING. OBSERVING
SITES THOUGH HAVE NOT REPORTED ANYTHING AND HAVE NOT SEEN ANYTHING
ON AREA WEBCAMS THUS FAR. STILL...WITH THE CIGS THIS LOW WILL
CONTINUE TO MENTION A SLIGHT CHANCE FOR LIGHT SNOW THIS
AM...LEANING ON THE LATEST HRRR OUTPUT. ZERO IMPACTS.
WEAK CAA BEHIND THE BOUNDARY AND IN THE WAKE OF THE UPPER TROUGH
TODAY INTO TONIGHT. DAYTIME HIGHS WILL BE WARMER SOME LOCATIONS
BUT REMAIN COLD RANGING FROM 10 ABOVE NEAR THE TURTLE MOUNTAINS TO
THE MID/UPPER 20S SOUTHWEST INTO FAR SOUTH CENTRAL. MOST MODELS
ARE INDICATING SOME LIGHT QPF WITH THE CAA TODAY OVER MY
NORTH...WHICH WAS ADDED INTO THE FORECAST LAST EVENING...SO SEE
NO REASON TO REMOVE.
MAINLY DRY WITH DECREASING CLOUDS TONIGHT AS SURFACE HIGH PRESSURE
BUILDS EASTWARD INTO THE DAKOTAS. LOWS GENERALLY 5 ABOVE TO 5
BELOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 309 AM CST TUE DEC 2 2014
BROAD PACIFIC RIDGING BUILDING OVER THE WESTERN CONUS WILL LEAD
TO MAINLY DRY CONDITIONS AND A WARMING TREND TO ABOVE NORMAL
TEMPERATURES BY THE END OF THE WEEK.
THE MEDIUM RANGE MODELS DIFFER WITH RESPECT TO THE TIMING AND
POSITION OF A SHORTWAVE POTENTIALLY AFFECTING NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. THE LATEST GEM/ECMWF ARE MORE
PROGRESSIVE AND FARTHER NORTH WITH THIS FEATURE...WHEREAS THE GFS
IS SLOWER AND FARTHER SOUTH. FOR NOW WILL SIDE WITH THE CONSENSUS
SOLUTIONS AND KEEP THE MENTION OF SNOW CHANCES NEAR THE TURTLE
MOUNTAIN REGION SUNDAY.
COOLER AIR IS THEN FORECAST TO FILTER IN BEHIND THE SHORTWAVE WITH
BELOW NORMAL TEMPERATURES EXPECTED MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 636 AM CST TUE DEC 2 2014
WEAK SURFACE COLD FRONT WILL MOVE ACROSS THE REGION. BKN MID
LEVEL CLOUDS NORTH WITH MOSTLY CLEAR CONDITIONS SOUTH ARE
FORECAST. VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE 12Z
PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...NH
LONG TERM...TM
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
309 AM CST TUE DEC 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CST TUE DEC 2 2014
RELATIVELY QUIET WEATHER WITH CONTINUED BELOW NORMAL TEMPERATURES
WILL BE THE MAIN HIGHLIGHTS IN THE SHORT TERM PERIOD.
CURRENTLY...LONG WAVE TROUGH AXIS SWINGING EAST INTO THE NORTHERN
PLAINS THIS MORNING...WITH AN EMBEDDED S/WV AT THE BASE OF THE
TROUGH MOVING EAST-SOUTHEAST ACROSS NORTH DAKOTA. THIS FEATURE IS
INTERACTING WITH A SOUTHWARD RETREATING FRONTAL BOUNDARY STRETCHED
WEST TO EAST ACROSS SOUTHEASTERN MONTANA INTO NORTHERN SOUTH
DAKOTA...RESULTING IN WEAK RADAR RETURNS ALONG TO NORTH OF THIS
BOUNDARY INCLUDING OVER MY SOUTHWESTERN COUNTIES. CIGS LOWERING
FROM 4-6K AGL SO POSSIBLE SOME LIGHT SNOW IS FALLING. OBSERVING
SITES THOUGH HAVE NOT REPORTED ANYTHING AND HAVE NOT SEEN ANYTHING
ON AREA WEBCAMS THUS FAR. STILL...WITH THE CIGS THIS LOW WILL
CONTINUE TO MENTION A SLIGHT CHANCE FOR LIGHT SNOW THIS
AM...LEANING ON THE LATEST HRRR OUTPUT. ZERO IMPACTS.
WEAK CAA BEHIND THE BOUNDARY AND IN THE WAKE OF THE UPPER TROUGH
TODAY INTO TONIGHT. DAYTIME HIGHS WILL BE WARMER SOME LOCATIONS
BUT REMAIN COLD RANGING FROM 10 ABOVE NEAR THE TURTLE MOUNTAINS TO
THE MID/UPPER 20S SOUTHWEST INTO FAR SOUTH CENTRAL. MOST MODELS
ARE INDICATING SOME LIGHT QPF WITH THE CAA TODAY OVER MY
NORTH...WHICH WAS ADDED INTO THE FORECAST LAST EVENING...SO SEE
NO REASON TO REMOVE.
MAINLY DRY WITH DECREASING CLOUDS TONIGHT AS SURFACE HIGH PRESSURE
BUILDS EASTWARD INTO THE DAKOTAS. LOWS GENERALLY 5 ABOVE TO 5
BELOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 309 AM CST TUE DEC 2 2014
BROAD PACIFIC RIDGING BUILDING OVER THE WESTERN CONUS WILL LEAD
TO MAINLY DRY CONDITIONS AND A WARMING TREND TO ABOVE NORMAL
TEMPERATURES BY THE END OF THE WEEK.
THE MEDIUM RANGE MODELS DIFFER WITH RESPECT TO THE TIMING AND
POSITION OF A SHORTWAVE POTENTIALLY AFFECTING NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. THE LATEST GEM/ECMWF ARE MORE
PROGRESSIVE AND FARTHER NORTH WITH THIS FEATURE...WHEREAS THE GFS
IS SLOWER AND FARTHER SOUTH. FOR NOW WILL SIDE WITH THE CONSENSUS
SOLUTIONS AND KEEP THE MENTION OF SNOW CHANCES NEAR THE TURTLE
MOUNTAIN REGION SUNDAY.
COOLER AIR IS THEN FORECAST TO FILTER IN BEHIND THE SHORTWAVE WITH
BELOW NORMAL TEMPERATURES EXPECTED MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 309 AM CST TUE DEC 2 2014
A WEAK COLD FRONT OVER WESTERN NORTH DAKOTA WILL MOVE ACROSS
CENTRAL NORTH DAKOTA TONIGHT. VFR CONDITIONS EXPECTED AT ALL TAF
SITES WITH MID AND HIGH LEVEL CLOUDS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NH
LONG TERM...TM
AVIATION...NH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
647 AM EST TUE DEC 2 2014
.SYNOPSIS...
COLD TEMPERATURES WILL ALLOW FOR THE POSSIBILITY OF LIGHT FREEZING
RAIN THIS MORNING...BEFORE TEMPERATURES BEGIN TO WARM UP. A AREA OF
HIGH PRESSURE WILL MOVE THROUGH THE GREAT LAKES ON WEDNESDAY AND
THURSDAY...PROVIDING DRY CONDITIONS FOR THE OHIO VALLEY. WARMING
TEMPERATURES AND A CHANCE FOR RAIN WILL RETURN BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COMPLICATED FORECAST HAS SET UP FOR THE MORNING...WITH
SIGNIFICANT UNCERTAINTY IN SEVERAL IMPORTANT FACTORS. THE FREEZING
RAIN ADVISORY PREVIOUSLY IN EFFECT HAS BEEN MAINTAINED...BUT
CONFIDENCE IN WIDESPREAD HAZARDOUS CONDITIONS IS NOT PARTICULARLY
HIGH.
A COLD AIR MASS AT THE SURFACE HAS BOTTOMED OUT...WITH THE
MAJORITY OF THE ILN FORECAST AREA BELOW FREEZING. A FEW SPOTS NEAR
AND SOUTH OF THE OHIO RIVER REMAIN IN THE 32-35 DEGREE RANGE.
TEMPERATURES ARE EXPECTED TO REMAIN VERY CLOSE TO CURRENT VALUES
UNTIL AFTER SUNRISE...WHEN A SLOW INCREASE IS EXPECTED TO BEGIN.
A SIGNIFICANT WARMING TREND HAS ALREADY BEGUN IN THE 925MB-800MB
LAYER...ALONG WITH SOME WEAK ASSOCIATED ISENTROPIC LIFT AND
CONVERGENCE. THIS WILL BE ONE OF THE WEAK FORCING MECHANISMS
HELPING TO GENERATE PRECIPITATION THIS MORNING...AND THE
EFFECTIVENESS OF THIS FORCING IS DUBIOUS AT BEST. THERE IS ALSO A
WEAK SHORTWAVE AT 700MB THAT IS MOVING INTO THE REGION...BUT THIS
WAVE IS UNDERGOING A DAMPENING OF AMPLITUDE. ALSO...700MB IS NEAR
THE TOP OF THE EXPECTED SOMEWHAT-SHALLOW LAYER OF NEAR-SATURATION
(GENERALLY AT AND BELOW 8KFT BASED ON RAP SOUNDINGS). EVEN ADDED
TOGETHER...IT IS HARD TO FIND SIGNIFICANT FORCING...AND IT IS NO
SURPRISE THAT MODEL QPF RESPONSE IS GENERALLY LIGHT AND SCATTERED.
THIS ALSO MATCHES CURRENT OBSERVATIONAL TRENDS...WITH ONLY WIDELY
SCATTERED OR ISOLATED PATCHES OF ECHOES ACROSS THE ILN FORECAST
AREA AND UPSTREAM. HRRR/RAP RUNS SUGGEST A MAXIMIZATION OF
PRECIPITATION COVERAGE NEAR 15Z...WITH THE GREATEST CHANCES IN
THE EASTERN (AND POSSIBLY NORTHEASTERN) SECTIONS OF THE FORECAST
AREA. ONLY THE 06Z NAM12 SUGGESTS WIDESPREAD PRECIPITATION AMOUNTS
OF MORE THAN ONE OR TWO HUNDREDTHS OF AN INCH...AND ITS DEWPOINT
INITIALIZATION WAS SEVERAL DEGREES TOO HIGH.
THE TEMPERATURE FORECAST IS ALSO A CAUSE FOR CONCERN...WITH WIDE
SPREAD IN THE EXPECTED TIMING AND MAGNITUDE OF NEAR-SURFACE
WARMING. SREF PLUMES SHOW OVER 10 DEGREES OF SPREAD AT
21Z...STRADDLING EITHER SIDE OF THE FREEZING MARK. THE LOW-LEVEL
ADVECTION IS NOT PARTICULARLY STRONG...AND WITH CLOUDS IN
PLACE...INSOLATION WILL NOT ADD MUCH TO THE WARMING EITHER. THE
WHOLE CWA SHOULD EVENTUALLY BREAK ABOVE FREEZING...BUT THIS IS
UNLIKELY TO HAPPEN QUICKLY. WITH DEWPOINTS STILL GENERALLY IN THE
LOWER 20S...SATURATION STILL NEEDS TO OCCUR...AND THIS MAY ALSO
HELP KEEP TEMPERATURES DOWN.
ULTIMATELY...WHAT IS EXPECTED IS THAT OBSERVED RADAR ECHOES WILL
SHOW A GRADUAL INCREASE IN COVERAGE AND INTENSITY BETWEEN NOW AND
15Z. HOWEVER...THE PRECIPITATION IS STILL EXPECTED TO REMAIN
SCATTERED IN NATURE. THERE COULD BE A FEW PATCHES OF RESPECTABLE
PRECIPITATION...PRODUCING SEVERAL HUNDREDTHS OF AN INCH OF LIQUID
EQUIVALENT. SOME LOCATIONS MAY ONLY END UP UNDER LIGHT ECHOES
(TRACE AMOUNTS). NEAR ONSET OF PRECIPITATION...LIGHT SLEET COULD
OCCUR...AS THE WARM LAYER ALOFT ONLY SLIGHTLY CROSSES THE FREEZING
MARK...AND NEAR-SURFACE SATURATION STILL OCCURS. AFTER
THAT...SOUNDINGS WILL STRONGLY FAVOR FREEZING RAIN UNTIL SURFACE
TEMPERATURES RISE ABOVE FREEZING. BASED ON THE EXPECTED
TEMPERATURE PROFILES...THE ADVISORY TIMING STILL LOOKED TO BE
ALIGNED NICELY. THE ONLY QUESTION IS ACTUALLY GETTING
PRECIPITATION TO OCCUR...AND IT MAY END UP THAT ISSUES ARE NOT
PARTICULARLY BAD IN MOST LOCATIONS. HOWEVER CONFIDENCE WAS NOT
HIGH ENOUGH IN THE ZERO-IMPACT BEST-CASE SCENARIO TO REMOVE ANY
OF THE ADVISORY WITH THIS FORECAST UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
A WEAK TROUGH JUST WEST OF THE APPALACHIANS WILL KEEP A CHANCE FOR
LIGHT RAIN IN THE FORECAST FOR THE FAR EASTERN CWA INTO THE EARLY
MORNING HOURS ON WEDNESDAY. AFTER THAT OCCURS...ANOTHER PUSH OF
COLD AND DRY AIR WILL PASS THROUGH THE GREAT LAKES...AS HIGH
PRESSURE SETTLES OVER THE OHIO VALLEY BY WEDNESDAY NIGHT. SOME
DOWNWARD ADJUSTMENTS WERE MADE TO THE TEMPERATURE FORECAST THROUGH
THIS PERIOD...AS THE SURFACE TEMPERATURE BOUNDARY IS NOW EXPECTED
TO REMAIN GENERALLY SOUTH OF THE ILN CWA THROUGH THE END OF THE
WEEK. SOME OF THE WARMER MODELS ALLOW FOR WARMING IN SOUTHERN OHIO
AND NORTHEAST KENTUCKY ON WEDNESDAY AFTERNOON...AND THE FORECAST
WILL ALLOW FOR THIS POSSIBILITY WITH SLIGHTLY WARMER TEMPERATURES
THERE.
DOMINATED BY HIGH PRESSURE...QUIET CONDITIONS ARE EXPECTED
THURSDAY...WITH SOUTHERLY FLOW BEGINNING AS THE HIGH MOVES OFF TO
THE EAST. A WAVE IN THE SOUTHERN STREAM FLOW SHOULD REMAIN SOUTH
OF THE ILN CWA...MEANING THAT ATTENTION FOR THE NEXT CHANCE OF
PRECIPITATION WILL FOCUS MORE ON FRIDAY. THIS IS AN ADJUSTMENT
FROM PREVIOUS FORECASTS...AS THE 00Z MODEL SUITE HAS TRENDED
SLOWER WITH THE RETURN OF DEEPER MOISTURE TO THE OHIO VALLEY. IT
NOW APPEARS THAT PRECIPITATION WILL BE MOST LIKELY FROM FRIDAY
AFTERNOON THROUGH SATURDAY MORNING. THE SLOWER ONSET MEANS THAT
PRECIPITATION TYPE ISSUES WERE LESS OF AN ISSUE WITH THIS SET OF
GRIDS...BUT SOME MIX WITH SNOW (OR POSSIBLY FREEZING
PRECIPITATION) COULD BE POSSIBLE AS WELL (MORE LIKELY IN THE
NORTHERN HALF OF THE CWA).
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODEL DIFFERENCES CONTINUE INTO THE WEEKEND AS BOTH THE 12Z ECMWF
AND 12Z CMC ARE STRONGER THAN THE 12Z GFS WITH THE DEVELOPING MID
LEVEL SHORT WAVE MOVING ACROSS THE CENTRAL UNITED STATES. AS A
RESULT...THE ECMWF AND CMC ARE STRONGER AND SLOWER WITH AN
ASSOCIATED SURFACE WAVE MOVING THROUGH THE TENNESSEE VALLEY FRIDAY
NIGHT INTO SATURDAY NIGHT. BASED ON THIS...WILL GO AHEAD AND
LINGER CHANCE POPS THROUGH ABOUT THE FIRST HALF OF THE WEEKEND.
SOME MID LEVEL RIDGING AND DRYING WILL BRIEFLY DEVELOP ACROSS THE
AREA ON SUNDAY AHEAD OF THE NEXT APPROACHING SHORT WAVE AND SLIGHT
CHANCE OF SHOWERS FOR MONDAY.
TEMPERATURES WILL BE FAIRLY SEASONABLE THROUGH THE LONG TERM PERIOD
WITH HIGHS MOSTLY IN THE 40S AND OVERNIGHT LOWS IN THE 30S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
CENTER OF ARCTIC HIGH PRESSURE OVER SOUTHERN QUEBEC THIS MORNING
WILL MOVE EAST TO A POSITION NEAR THE MOUTH OF THE ST. LAWRENCE
RIVER BY 00Z WEDNESDAY. AS THIS OCCURS...LOW LEVEL FLOW WILL VEER
WITH TIME ALONG WITH INCREASING WARM...MOIST ADVECTION ALOFT. AN
EMBEDDED DISTURBANCE IN THE WEST TO SOUTHWEST FLOW ALOFT WILL
COMBINE WITH WEAK LIFT IN THE DEVELOPING WARM...MOIST PATTERN
ALOFT TO GENERATE SOME LIGHT PRECIPITATION...MAINLY BETWEEN 12Z
AND 18Z. WITH TEMPERATURES NEAR OR BELOW FREEZING...THIS
PRECIPITATION WILL LIKELY FALL AS LIGHT FREEZING RAIN OR SLEET AT
THE SURFACE FOR A BRIEF PERIOD OF TIME. THIS SHOULD BE MAINLY
NORTH OF THE OHIO RIVER. RIGHT NOW...THINKING THE PCPN WILL BE
LIGHT ENOUGH NOT TO RESTRICT VISIBILITIES. HOWEVER...LOW LEVEL
MOISTURE SOUTH OF THE OHIO RIVER WILL EVENTUALLY GET PULLED/ADVECTED
NORTH THAN NORTHEAST THROUGH TIME. THIS WILL RESULT IN LOWERING
CEILINGS WHICH WILL EVENTUALLY DROP INTO THE IFR CATEGORY. PCPN
WILL EXIT THE REGION AFTER 18Z AS DEEPER MOISTURE AND LIFT WITH
THE DISTURBANCE MOVE OFF TO THE EAST/NORTHEAST.
FOR TONIGHT...REGION SHOULD BE STUCK IN THE LOW LEVEL MOIST...WAA
PATTERN WHICH WILL CONTINUE THE IFR CEILINGS INTO WEDNESDAY
MORNING.
OUTLOOK...MVFR/IFR CEILINGS EXPECTED TO LINGER INTO WEDNESDAY.
MVFR/IFR CONDITIONS POSSIBLE FRIDAY AND SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ053>056-060>065-073-074.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ070>072-077>082-088.
KY...FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
KYZ091>093.
IN...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
INZ058-059.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR INZ066-
073>075-080.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
419 AM EST TUE DEC 2 2014
.SYNOPSIS...
COLD TEMPERATURES WILL ALLOW FOR THE POSSIBILITY OF LIGHT FREEZING
RAIN THIS MORNING...BEFORE TEMPERATURES BEGIN TO WARM UP. A AREA OF
HIGH PRESSURE WILL MOVE THROUGH THE GREAT LAKES ON WEDNESDAY AND
THURSDAY...PROVIDING DRY CONDITIONS FOR THE OHIO VALLEY. WARMING
TEMPERATURES AND A CHANCE FOR RAIN WILL RETURN BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COMPLICATED FORECAST HAS SET UP FOR THE MORNING...WITH
SIGNIFICANT UNCERTAINTY IN SEVERAL IMPORTANT FACTORS. THE FREEZING
RAIN ADVISORY PREVIOUSLY IN EFFECT HAS BEEN MAINTAINED...BUT
CONFIDENCE IN WIDESPREAD HAZARDOUS CONDITIONS IS NOT PARTICULARLY
HIGH.
A COLD AIR MASS AT THE SURFACE HAS BOTTOMED OUT...WITH THE
MAJORITY OF THE ILN FORECAST AREA BELOW FREEZING. A FEW SPOTS NEAR
AND SOUTH OF THE OHIO RIVER REMAIN IN THE 32-35 DEGREE RANGE.
TEMPERATURES ARE EXPECTED TO REMAIN VERY CLOSE TO CURRENT VALUES
UNTIL AFTER SUNRISE...WHEN A SLOW INCREASE IS EXPECTED TO BEGIN.
A SIGNIFICANT WARMING TREND HAS ALREADY BEGUN IN THE 925MB-800MB
LAYER...ALONG WITH SOME WEAK ASSOCIATED ISENTROPIC LIFT AND
CONVERGENCE. THIS WILL BE ONE OF THE WEAK FORCING MECHANISMS
HELPING TO GENERATE PRECIPITATION THIS MORNING...AND THE
EFFECTIVENESS OF THIS FORCING IS DUBIOUS AT BEST. THERE IS ALSO A
WEAK SHORTWAVE AT 700MB THAT IS MOVING INTO THE REGION...BUT THIS
WAVE IS UNDERGOING A DAMPENING OF AMPLITUDE. ALSO...700MB IS NEAR
THE TOP OF THE EXPECTED SOMEWHAT-SHALLOW LAYER OF NEAR-SATURATION
(GENERALLY AT AND BELOW 8KFT BASED ON RAP SOUNDINGS). EVEN ADDED
TOGETHER...IT IS HARD TO FIND SIGNIFICANT FORCING...AND IT IS NO
SURPRISE THAT MODEL QPF RESPONSE IS GENERALLY LIGHT AND SCATTERED.
THIS ALSO MATCHES CURRENT OBSERVATIONAL TRENDS...WITH ONLY WIDELY
SCATTERED OR ISOLATED PATCHES OF ECHOES ACROSS THE ILN FORECAST
AREA AND UPSTREAM. HRRR/RAP RUNS SUGGEST A MAXIMIZATION OF
PRECIPITATION COVERAGE NEAR 15Z...WITH THE GREATEST CHANCES IN
THE EASTERN (AND POSSIBLY NORTHEASTERN) SECTIONS OF THE FORECAST
AREA. ONLY THE 06Z NAM12 SUGGESTS WIDESPREAD PRECIPITATION AMOUNTS
OF MORE THAN ONE OR TWO HUNDREDTHS OF AN INCH...AND ITS DEWPOINT
INITIALIZATION WAS SEVERAL DEGREES TOO HIGH.
THE TEMPERATURE FORECAST IS ALSO A CAUSE FOR CONCERN...WITH WIDE
SPREAD IN THE EXPECTED TIMING AND MAGNITUDE OF NEAR-SURFACE
WARMING. SREF PLUMES SHOW OVER 10 DEGREES OF SPREAD AT
21Z...STRADDLING EITHER SIDE OF THE FREEZING MARK. THE LOW-LEVEL
ADVECTION IS NOT PARTICULARLY STRONG...AND WITH CLOUDS IN
PLACE...INSOLATION WILL NOT ADD MUCH TO THE WARMING EITHER. THE
WHOLE CWA SHOULD EVENTUALLY BREAK ABOVE FREEZING...BUT THIS IS
UNLIKELY TO HAPPEN QUICKLY. WITH DEWPOINTS STILL GENERALLY IN THE
LOWER 20S...SATURATION STILL NEEDS TO OCCUR...AND THIS MAY ALSO
HELP KEEP TEMPERATURES DOWN.
ULTIMATELY...WHAT IS EXPECTED IS THAT OBSERVED RADAR ECHOES WILL
SHOW A GRADUAL INCREASE IN COVERAGE AND INTENSITY BETWEEN NOW AND
15Z. HOWEVER...THE PRECIPITATION IS STILL EXPECTED TO REMAIN
SCATTERED IN NATURE. THERE COULD BE A FEW PATCHES OF RESPECTABLE
PRECIPITATION...PRODUCING SEVERAL HUNDREDTHS OF AN INCH OF LIQUID
EQUIVALENT. SOME LOCATIONS MAY ONLY END UP UNDER LIGHT ECHOES
(TRACE AMOUNTS). NEAR ONSET OF PRECIPITATION...LIGHT SLEET COULD
OCCUR...AS THE WARM LAYER ALOFT ONLY SLIGHTLY CROSSES THE FREEZING
MARK...AND NEAR-SURFACE SATURATION STILL OCCURS. AFTER
THAT...SOUNDINGS WILL STRONGLY FAVOR FREEZING RAIN UNTIL SURFACE
TEMPERATURES RISE ABOVE FREEZING. BASED ON THE EXPECTED
TEMPERATURE PROFILES...THE ADVISORY TIMING STILL LOOKED TO BE
ALIGNED NICELY. THE ONLY QUESTION IS ACTUALLY GETTING
PRECIPITATION TO OCCUR...AND IT MAY END UP THAT ISSUES ARE NOT
PARTICULARLY BAD IN MOST LOCATIONS. HOWEVER CONFIDENCE WAS NOT
HIGH ENOUGH IN THE ZERO-IMPACT BEST-CASE SCENARIO TO REMOVE ANY
OF THE ADVISORY WITH THIS FORECAST UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
A WEAK TROUGH JUST WEST OF THE APPALACHIANS WILL KEEP A CHANCE FOR
LIGHT RAIN IN THE FORECAST FOR THE FAR EASTERN CWA INTO THE EARLY
MORNING HOURS ON WEDNESDAY. AFTER THAT OCCURS...ANOTHER PUSH OF
COLD AND DRY AIR WILL PASS THROUGH THE GREAT LAKES...AS HIGH
PRESSURE SETTLES OVER THE OHIO VALLEY BY WEDNESDAY NIGHT. SOME
DOWNWARD ADJUSTMENTS WERE MADE TO THE TEMPERATURE FORECAST THROUGH
THIS PERIOD...AS THE SURFACE TEMPERATURE BOUNDARY IS NOW EXPECTED
TO REMAIN GENERALLY SOUTH OF THE ILN CWA THROUGH THE END OF THE
WEEK. SOME OF THE WARMER MODELS ALLOW FOR WARMING IN SOUTHERN OHIO
AND NORTHEAST KENTUCKY ON WEDNESDAY AFTERNOON...AND THE FORECAST
WILL ALLOW FOR THIS POSSIBILITY WITH SLIGHTLY WARMER TEMPERATURES
THERE.
DOMINATED BY HIGH PRESSURE...QUIET CONDITIONS ARE EXPECTED
THURSDAY...WITH SOUTHERLY FLOW BEGINNING AS THE HIGH MOVES OFF TO
THE EAST. A WAVE IN THE SOUTHERN STREAM FLOW SHOULD REMAIN SOUTH
OF THE ILN CWA...MEANING THAT ATTENTION FOR THE NEXT CHANCE OF
PRECIPITATION WILL FOCUS MORE ON FRIDAY. THIS IS AN ADJUSTMENT
FROM PREVIOUS FORECASTS...AS THE 00Z MODEL SUITE HAS TRENDED
SLOWER WITH THE RETURN OF DEEPER MOISTURE TO THE OHIO VALLEY. IT
NOW APPEARS THAT PRECIPITATION WILL BE MOST LIKELY FROM FRIDAY
AFTERNOON THROUGH SATURDAY MORNING. THE SLOWER ONSET MEANS THAT
PRECIPITATION TYPE ISSUES WERE LESS OF AN ISSUE WITH THIS SET OF
GRIDS...BUT SOME MIX WITH SNOW (OR POSSIBLY FREEZING
PRECIPITATION) COULD BE POSSIBLE AS WELL (MORE LIKELY IN THE
NORTHERN HALF OF THE CWA).
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODEL DIFFERENCES CONTINUE INTO THE WEEKEND AS BOTH THE 12Z ECMWF
AND 12Z CMC ARE STRONGER THAN THE 12Z GFS WITH THE DEVELOPING MID
LEVEL SHORT WAVE MOVING ACROSS THE CENTRAL UNITED STATES. AS A
RESULT...THE ECMWF AND CMC ARE STRONGER AND SLOWER WITH AN
ASSOCIATED SURFACE WAVE MOVING THROUGH THE TENNESSEE VALLEY FRIDAY
NIGHT INTO SATURDAY NIGHT. BASED ON THIS...WILL GO AHEAD AND
LINGER CHANCE POPS THROUGH ABOUT THE FIRST HALF OF THE WEEKEND.
SOME MID LEVEL RIDGING AND DRYING WILL BRIEFLY DEVELOP ACROSS THE
AREA ON SUNDAY AHEAD OF THE NEXT APPROACHING SHORT WAVE AND SLIGHT
CHANCE OF SHOWERS FOR MONDAY.
TEMPERATURES WILL BE FAIRLY SEASONABLE THROUGH THE LONG TERM PERIOD
WITH HIGHS MOSTLY IN THE 40S AND OVERNIGHT LOWS IN THE 30S.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
CENTER OF ARCTIC HIGH PRESSURE OVER SOUTHERN QUEBEC EARLY THIS
MORNING WILL MOVE EAST TO A POSITION NEAR THE MOUTH OF THE ST.
LAWRENCE RIVER BY 00Z WEDNESDAY. AS THIS OCCURS...LOW LEVEL FLOW
WILL VEER WITH TIME ALONG WITH INCREASING WARM...MOIST ADVECTION
ALOFT. AN EMBEDDED DISTURBANCE IN THE WEST TO SOUTHWEST FLOW
ALOFT WILL COMBINE WITH WEAK LIFT IN THE DEVELOPING WARM...MOIST
PATTERN ALOFT TO GENERATE SOME LIGHT PRECIPITATION...MAINLY
BETWEEN 12Z AND 18Z. WITH TEMPERATURES NEAR OR BELOW
FREEZING...THIS PRECIPITATION WILL LIKELY FALL AS FREEZING RAIN AT
THE SURFACE FOR A PERIOD OF TIME. RIGHT NOW...THINKING THE PCPN
WILL BE LIGHT ENOUGH NOT TO RESTRICT VISIBILITIES. HOWEVER...LOW
LEVEL MOISTURE SOUTH OF THE OHIO RIVER WILL EVENTUALLY GET
PULLED/ADVECTED NORTH THAN NORTHEAST THROUGH TIME. THIS WILL
RESULT IN LOWERING CEILINGS WHICH WILL EVENTUALLY DROP INTO THE
IFR CATEGORY. PCPN WILL EXIT THE REGION AFTER 18Z AS DEEPER
MOISTURE AND LIFT WITH THE DISTURBANCE MOVE OFF TO THE
EAST/NORTHEAST.
FOR TONIGHT...REGION SHOULD BE STUCK IN THE LOW LEVEL MOIST...WAA
PATTERN WHICH WILL CONTINUE THE IFR CEILINGS INTO WEDNESDAY
MORNING.
OUTLOOK...MVFR/IFR CEILINGS EXPECTED TO LINGER INTO WEDNESDAY.
MVFR/IFR CONDITIONS POSSIBLE FRIDAY AND SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR OHZ053>056-060>065-073-074.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ070>072-077>082-088.
KY...FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
KYZ091>093.
IN...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR INZ058-059.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR INZ066-
073>075-080.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1253 AM EST TUE DEC 2 2014
.SYNOPSIS...
MUCH COLDER AIR WILL FILTER INTO THE AREA TONIGHT BEHIND A COLD
FRONT. PRECIPITATION WILL WORK BACK INTO THE REGION LATE TONIGHT
AS AIR IS LIFTED OVER THE FRONT. SUB FREEZING SURFACE TEMPERATURES
COULD LEAD TO SOME FREEZING RAIN. THE PRECIPITATION WILL GRADUALLY
WORK EAST OF THE REGION TUESDAY NIGHT. FOR WEDNESDAY INTO
WEDNESDAY NIGHT...HIGH PRESSURE WILL SLOWLY WORK INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
IN RIGHT REAR ENTRANCE REGION OF UPR LEVEL JET ALONG WITH SOME H8
JET CONVERGENCE LED TO WIDESPREAD AREA OF PCPN ACRS THE REGION
THIS AFTN. INITIAL WEAK IMPULSE EXITING THE REGION WITH PCPN IN A
GENERAL LULL ATTM.
FOCUS SHIFTS TO NEXT WEAK SYSTEM PIVOTING THRU THE REGION. WEAK
ISENTROPIC LIFT DEVELOPS WITH MOISTURE OVERRUNNING THE STALLED SFC
FNT TO OUR SOUTH OVERNIGHT. THIS EVENT LOOKS TO BE A VERY LIGHT
QPF EVENT. LATEST RUNS WOULD SUGGEST MOST AREAS RECEIVE QPF OF
LESS THAN A TENTH OF AN INCH. WITH A NE LOW LEVEL FLOW TEMPERATURES
WILL BE AT OR BELOW FREEZING FOR SEVERAL HOURS AROUND SUNRISE AND
INTO THE EARLY MORNING.
RAP MODEL HAD GOOD HANDLE ON THIS EVENINGS 00Z ILN SOUNDING. HAVE
TRENDED HOURLY TEMPERATURE SOLN TOWARD LATEST RAP AND FOR
PRECIPITATION TYPE HAVE ADJUSTED TOWARD SREF SOLN. THIS YIELDS
A 2 TO 4 HOUR PERIOD OF VERY LIGHT FREEZING RAIN OVER THE EXISTING
FREEZING RAIN ADVSY AREA. THEREFORE...HAVE CONTINUED EXISTING FREEZING
RAIN ADVSY. HAVE ADDED SCIOTO COUNTY WHERE TEMPS ALSO LOOK TO BE
AT OR BELOW FREEZING FOR A FEW HOURS EARLY TUESDAY MORNING.
AS BOUNDARY LAYER WARMS UP LIGHT PCPN WILL CHANGE TO RAIN TUESDAY
MORNING FROM SOUTH TO NORTH.
PREV DISCUSSION...
THIS AFTERNOONS WINTRY MIX OF RAIN...SLEET AND SNOW CONTINUES TO WORK
TO THE EAST. LATEST TIMING HAS IT LINGERING IN THE SOUTHEAST AT
THE BEGINNING OF THE TONIGHT PERIOD. AS THE EVENING
PROGRESSES...THE PCPN WILL GET SHUNTED EAST AND SOUTH OF THE
REGION.
HIGH PRESSURE PASSING TO THE NORTH OF THE GREAT LAKES WILL WORK TO
NEW ENGLAND BY 12Z TUESDAY. THIS WILL CAUSE THE FLOW TO BECOME
SOUTHERLY AND MOISTURE WILL BE LIFTED NORTH ACROSS THE STALLED
BOUNDARY. CRITICAL THICKNESSES ARE SHOWING THE ATMOSPHERE WILL BE
WARM ENOUGH FOR RAIN...BUT WITH SUBFREEZING TEMPERATURES WORKING IN
TONIGHT BEHIND A COLD FRONT...THE AREA COULD EXPERIENCE SOME
FREEZING RAIN LATE TONIGHT INTO TUESDAY MORNING. THE 12Z MODEL
RUNS HAVE BECOME MORE AGGRESSIVE WITH THE PCPN ASSOCIATED WITH THIS
EVENT. IT LOOKS LIKE THE SOUTHERN COUNTIES IN NRN KENTUCKY WILL
STAY ABOVE FREEZING TONIGHT...SO THE THREAT SHOULD BE A LITTLE
FARTHER NORTH. ISSUED A FREEZING RAIN ADVISORY FROM THE CVG TRI-
STATE AREA OVER TO PIKE COUNTY OHIO...NORTHWARD TO AROUND I-70.
LOW TEMPERATURES WILL RANGE FROM THE MID 20S IN WEST CENTRAL OHIO
TO THE LOWER 30S IN NRN KENTUCKY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
THE PCPN WILL LIFT NORTH QUICKLY ON TUESDAY. SFC TEMPERATURES WILL
STRUGGLE TO WARM. FREEZING RAIN COULD LINGER AROUND I-70 TO AROUND
18Z. NORTH OF I-70...PCPN SHOULD FALL AS SNOW OR SLEET. TEMPERATURES
WILL GRADUALLY WARM ON TUESDAY REACHING THE LOWER 40S IN THE SOUTH
AND THE UPPER 30S IN THE NORTH.
THE PCPN WILL BEGIN TO TRANSITION TO THE EAST TUESDAY AFTERNOON.
PCPN WILL LINGER IN THE EAST INTO TUESDAY NIGHT. HIGH PRESSURE
WILL BEGIN TO NOSE IN WEDNESDAY AND WILL BECOME MORE ENTRENCHED
WEDNESDAY NIGHT.
HIGHS ON WEDNESDAY WILL RECOVER INTO THE 40S AND LOWER 50S,
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE IN PLACE ACROSS THE REGION THURSDAY MORNING
WILL BEGIN TO SHIFT OFF TO THE EAST THROUGH THE DAY. INCREASING
SOUTHWESTERLY LOW LEVEL FLOW ON THE BACK SIDE OF THE HIGH WILL LEAD
TO SOME DEVELOPING ISENTROPIC LIFT THURSDAY INTO THURSDAY NIGHT.
THERE IS QUITE A BIT OF MODEL VARIATION IN THE ONSET OF ANY PCPN
THOUGH SO WILL TREND TOWARD THE 12Z ECMWF WHICH IS IN BETWEEN THE
FASTER GFS AND SLOWER CMC. WITH THIS IN MIND...WILL HAVE SOME LOWER
CHANCE POPS DEVELOPING INTO THE FAR SOUTH LATE THURSDAY AFTERNOON
AND THEN ALLOW FOR HIGHER CHANCE POPS TO SPREAD NORTHWARD THURSDAY
NIGHT. PTYPE COULD BE A BIT OF AN ISSUE THURSDAY NIGHT INTO FRIDAY
MORNING DEPENDING ON HOW FAST THE PCPN MOVES IN AND/OR THE COLDER
AIRMASS RETREATS NORTHWARD IN THE DEVELOPING WAA. FOR NOW WILL ALLOW
FOR SOME SNOW OR RAIN/SNOW MIX ACROSS THE NORTH BEFORE CHANGING PCPN
OVER TO ALL RAIN THROUGH THE DAY ON FRIDAY.
MODEL DIFFERENCES CONTINUE INTO THE WEEKEND AS BOTH THE 12Z ECMWF
AND 12Z CMC ARE STRONGER THAN THE 12Z GFS WITH THE DEVELOPING MID
LEVEL SHORT WAVE MOVING ACROSS THE CENTRAL UNITED STATES. AS A
RESULT...THE ECMWF AND CMC ARE STRONGER AND SLOWER WITH AN
ASSOCIATED SURFACE WAVE MOVING THROUGH THE TENNESSEE VALLEY FRIDAY
NIGHT INTO SATURDAY NIGHT. BASED ON THIS...WILL GO AHEAD AND LINGER
CHANCE POPS THROUGH ABOUT THE FIRST HALF OF THE WEEKEND. SOME MID
LEVEL RIDGING AND DRYING WILL BRIEFLY DEVELOP ACROSS THE AREA ON
SUNDAY AHEAD OF THE NEXT APPROACHING SHORT WAVE AND SLIGHT CHANCE OF
SHOWERS FOR MONDAY.
TEMPERATURES WILL BE FAIRLY SEASONABLE THROUGH THE LONG TERM PERIOD
WITH HIGHS MOSTLY IN THE 40S AND OVERNIGHT LOWS IN THE 30S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
CENTER OF ARCTIC HIGH PRESSURE OVER SOUTHERN QUEBEC EARLY THIS
MORNING WILL MOVE EAST TO A POSITION NEAR THE MOUTH OF THE ST.
LAWRENCE RIVER BY 00Z WEDNESDAY. AS THIS OCCURS...LOW LEVEL FLOW
WILL VEER WITH TIME ALONG WITH INCREASING WARM...MOIST ADVECTION
ALOFT. AN EMBEDDED DISTURBANCE IN THE WEST TO SOUTHWEST FLOW
ALOFT WILL COMBINE WITH WEAK LIFT IN THE DEVELOPING WARM...MOIST
PATTERN ALOFT TO GENERATE SOME LIGHT PRECIPITATION...MAINLY
BETWEEN 12Z AND 18Z. WITH TEMPERATURES NEAR OR BELOW
FREEZING...THIS PRECIPITATION WILL LIKELY FALL AS FREEZING RAIN AT
THE SURFACE FOR A PERIOD OF TIME. RIGHT NOW...THINKING THE PCPN
WILL BE LIGHT ENOUGH NOT TO RESTRICT VISIBILITIES. HOWEVER...LOW
LEVEL MOISTURE SOUTH OF THE OHIO RIVER WILL EVENTUALLY GET
PULLED/ADVECTED NORTH THAN NORTHEAST THROUGH TIME. THIS WILL
RESULT IN LOWERING CEILINGS WHICH WILL EVENTUALLY DROP INTO THE
IFR CATEGORY. PCPN WILL EXIT THE REGION AFTER 18Z AS DEEPER
MOISTURE AND LIFT WITH THE DISTURBANCE MOVE OFF TO THE
EAST/NORTHEAST.
FOR TONIGHT...REGION SHOULD BE STUCK IN THE LOW LEVEL MOIST...WAA
PATTERN WHICH WILL CONTINUE THE IFR CEILINGS INTO WEDNESDAY
MORNING.
OUTLOOK...MVFR/IFR CEILINGS EXPECTED TO LINGER INTO WEDNESDAY.
MVFR/IFR CONDITIONS POSSIBLE FRIDAY AND SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR OHZ053>056-060>065-073-074.
FREEZING RAIN ADVISORY FROM 4 AM TO 10 AM EST THIS MORNING FOR
OHZ070>072-077>082-088.
KY...FREEZING RAIN ADVISORY FROM 4 AM TO 10 AM EST THIS MORNING FOR
KYZ091>093.
IN...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR INZ058-059.
FREEZING RAIN ADVISORY FROM 4 AM TO 10 AM EST THIS MORNING FOR
INZ066-073>075-080.
&&
$$
SYNOPSIS...HICKMAN/SITES
NEAR TERM...AR
SHORT TERM...SITES
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS TULSA OK
1121 PM CST MON DEC 1 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
FOR THE 6Z TAFS... CEILINGS HAVE LOWERED TO IFR LEVELS IN PORTIONS
OF WESTERN ARKANSAS... AND WILL LIKELY BOUNCE BETWEEN IFR AND
MVFR INTO MID MORNING TUESDAY AT THOSE TAF SITES. MVFR CEILINGS WILL
ALSO CONTINUE AT KMLC... WHILE OTHER EASTERN OKLAHOMA SITES
CONTINUE TO HAVE CEILINGS ABOVE 3K FEET. VFR CONDITIONS ARE
EXPECTED TO RETURN TO ALL SITES BY MID DAY TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 801 PM CST MON DEC 1 2014/
UPDATE...
LOWS HAVE BEEN ADJUSTED BASED ON THE LATEST OBS/HRRR MODEL TRENDS. SEE
DISCUSSION BELOW.
DISCUSSION...
THE LATEST HRRR DATA SUGGESTS THAT THE CLOUDS WILL BREAK FROM WEST
TO EAST TOWARD DAWN. HOWEVER...IT IS TYPICAL FOR THE MODEL
GUIDANCE TO GET RID OF THE LOW CLOUDS FASTER THAN IT ACTUALLY
OCCURS THIS TIME OF YEAR. FOR THIS UPDATE...I HAVE TWEAKED LOWS UP
IN THE WEST A FEW DEGREES GIVEN THE REAL POSSIBILITY THAT THE
CLOUDS WILL PROVIDE A BLANKET THE ENTIRE NIGHT.
LACY
PREV DISCUSSION... /ISSUED 514 PM CST MON DEC 1 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
FOR THE 0Z TAFS... MVFR CEILINGS WILL PREVAIL AT WESTERN ARKANSAS
SITES THROUGH MOST OF THE OVERNIGHT HOURS. HIGHER CEILINGS WILL
PREVAIL AT EASTERN OKLAHOMA SITES. VFR CONDITIONS ARE EXPECTED TO
RETURN TO ALL SITES DURING THE DAY TUESDAY.
PREV DISCUSSION... /ISSUED 342 PM CST MON DEC 1 2014/
DISCUSSION...
THIN LAYER SC CLOUD OVER FORECAST AREA PROBLEMATIC
FOR THE OVERNIGHT MIN TEMPERATURE FORECAST. MODELS
DIFFER ON HOW PERSISTENT THAT CLOUD LAYER WILL BE.
FAIRLY CONFIDENT NORTHWEST AR ZONES WILL REMAIN
CLOUDY WHILE WESTERN ZONES EVENTUALLY CLEAR. USING
LATEST RUC/HRRR SOLUTION WHICH LEADS TO TEENS WEST
LOW-MID 20S EAST WITH CLOUD COVER.
NORTHWEST UPPER FLOW WILL BACK TO WEST - SOUTHWEST
OPENING DOOR TO INCREASING MOISTURE ON LOWER LEVEL
SOUTHERLY FLOW. CHANCE FOR PRECIPITATION AS EARLY
AS WEDNESDAY...WITH THE BEST CHANCE THURSDAY NIGHT
AND FRIDAY WITH UPPER SUPPORT.
LOW CHANCE/MARGINAL POP SATURDAY MAINLY SOUTH I-40.
UPPER WAVE THAT REACHES THE WEST COAST FRIDAY WILL
BRING OUR AREA A GOOD (OR BETTER) CHANCE OF RAIN
SUNDAY AND SUNDAY NIGHT. SLOWER ECMWF WOULD TARGET
LATE SUNDAY..WITH MOST OF THE PRECIP SUNDAY NIGHT.
TEMPERATURES FRIDAY THROUGH THE WEEKEND BIT ABOVE
NORMAL. GW
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
200 AM EST TUE DEC 2 2014
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE WILL MOVE TOWARD THE REGION
TUESDAY...BRINGING A LIGHT WINTRY MIX THAT WILL LAST INTO TUESDAY
NIGHT. A LARGE HIGH PRESSURE AREA WILL THEN SLIDE OVER THE GREAT
LAKES INTO NEW ENGLAND IN THE SECOND HALF OF THE WEEK. LOW PRESSURE
OVER THE TENNESSEE VALLEY MAY MOVE INTO THE MID- ATLANTIC STATES
THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
TIGHT BAROCLINIC ZONE REMAINS JUST SOUTH OF PA EARLY THIS
MORNING...PRODUCING SOME LIGHT OVERRUNNING PRECIP OVER VIRGINIA
INTO EXTREME SE PA AT 06Z. UPSTREAM RADAR TRENDS AND LATEST NEAR
TERM MDL DATA FAVORS KEEPING THE PRECIP LIMITED TO AREAS SOUTH OF
A KHGR TO KLNS LINE THRU DAWN. ALTHOUGH 06Z SFC OBS REPORTING RAIN
AT KTHV...MDL SOUNDINGS INDICATE A TRANSITION TO MAINLY SLEET
TOWARD DAWN...AS NORTHERLY FLOW ADVECTS COLDER AIR INTO SOUTHERN
PA.
A BLEND OF LATEST LAMP AND HRRR GUIDANCE SUGGESTS TEMPS WILL
CONTINUE TO COAST DOWNWARD EARLY THIS MORNING...WITH 12Z TEMPS
RANGING FROM THE UTEENS OVR THE N MTNS...TO THE L30S OVR THE LOWER
SUSQ VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
FREEZING RAIN AND WINTER WEATHER ADVISORIES HIGHLIGHT THE UPCOMING
LIGHT AND GENERALLY NUISANCE WEATHER EVENT FOR TUESDAY INTO
TUESDAY NIGHT.
LIGHT PRECIP...INITIALLY IN THE FORM OF LIGHT SNOW AND SLEET WILL
BE SPREADING NORTH ACROSS THE AREA EARLY TUESDAY...BEFORE
OVERSPREADING CENTRAL AND NORTHERN AREAS DURING THE MORNING INTO
EARLY AFTERNOON.
A VERY COMPLICATED PRECIP TYPE/TRANSITION WILL OCCUR BETWEEN
12Z TUESDAY AND 12Z WEDNESDAY...THANKS TO A SLOWLY RETREATING
RELATIVELY SHALLOW COLD AIR MASS.
A WAVE OF LOW PRESSURE WILL SLIDE NE FROM THE OHIO VALLEY
BENEATH THE WELL-DEFINED RIGHT ENTRANCE REGION OF A STRONG 130-150
KT UPPER LEVEL JET THAT WILL BE STRETCHED FROM THE UPPER OHIO
RIVER VALLEY AND LOWER GLAKES REGION.
AFTER AN INITIAL FEW...TO SVRL HOUR PERIOD OF WET SNOW/SLEET
DURING THE MORNING TO EARLY AFTERNOON HOURS HEADING FROM SOUTH TO
NORTH...A CHANGEOVER TO MAINLY LIGHT FREEZING RAIN AND FREEZING
DRIZZLE IS EXPECTED FOR LATER TUESDAY AFTERNOON AND TUESDAY NIGHT.
SNOWFALL/SLEET AMOUNTS TUESDAY WILL BE AOB 1 INCH IN MOST
PLACES...FOLLOWED BY AROUND 0.10 OF ICE ACROSS SCENT PENN. UP TO
0.25 OF AN INCH OF GLAZING IS POSSIBLE BY 09Z WED ACROSS THE
LAURELS AND NW MTNS...NEAR AND JUST TO THE EAST OF THE RT 219
CORRIDOR.
LATE DAY MAX TEMPS TUESDAY WILL BE IN THE LOWER TO MID 30S AT
BEST. ANY FCST TEMP ERRORS TUESDAY WILL BE ON THE HIGH SIDE
CONSIDERING THE VERY LOW SFC DEWPOINTS HEADED OUR WAY /FOR LATE
MONDAY NIGHT INTO TUESDAY/ FROM THE UPPER MIDWEST.
TEMPS SHOULD WARM UP ENOUGH AT THE SFC TO TURN THE PRECIP TO
LIGHT RAIN LATER TUES NIGHT ACROSS THE LAURELS AND LOWER SUSQ
VALLEY...WHILE AREAS OF LIGHT FZRA OR FZDZ COULD PERSIST THROUGH
MOST OR ALL OF THE NIGHT THROUGHOUT THE CENTRAL AND NRN MTNS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE LONG TERM BEGINS AT THE TAIL END OF A MARGINAL EVENT. WARM AIR
CONTINUES TO STREAM IN ALOFT...WITH 850MB TEMPS AT 00Z WEDNESDAY
AROUND +3C AND INCREASING AS THE NIGHT CONTINUES. WITH COLD AIR
DAMMING TAKING PLACE EXPECT PERIODS OF RAIN TO FREEZING RAIN TO
CONTINUE INTO WEDNESDAY MORNING. THE FREEZING RAIN WILL
LINGER...ESPECIALLY IN CENTRAL PA WHERE IT WILL BE DECOUPLED. THE
LOWER SUSQ..AND THE ELEVATED REGIONS THAT MIX OUT...OR WHERE THE
WARM AIR REACHES THE SFC...WILL SEE RAIN.
BY MID WEDNESDAY MORNING...ANY LINGERING PRECIPITATION WILL
SWITCH TO RAIN. ONCE THE TROUGH LIFTS TO THE NORTHEAST THE PRECIP
WILL CEASE ABRUPTLY AND DRY...COLD NORTHWESTERLY FLOW WILL
DOMINATE THE PATTERN AGAIN. MAINLY ZONAL FLOW PATTERN WILL ONCE
AGAIN PERSIST THROUGH THE SECOND HALF OF THE WEEK.
ANOTHER LARGE HIGH PRESSURE AREA WILL MOVE FROM THE UPPER
PLAINS/MIDWEST INTO THE EASTERN U.S. FOR THE LATTER HALF OF THE
WEEK. A BUBBLING- UP OF MOISTURE/PRECIP FROM THE OHIO/TENN VALLEYS
IS AN AGREED-UPON SOLUTION AMONG THE VARIOUS GUID MEMBERS.
THUS...SOME PRECIP IS POSSIBLE FOR THE WEEKEND. HOWEVER...THE EC
AND GFS THEN DIFFER ON WHAT DOES/NOT DEVELOP ON THE COAST. THEY
ARE IN SLIGHTLY BETTER AGREEMENT TODAY...BUT STILL MAJOR VARIANCES
OM TIMING AND INTENSITY. WILL HOLD THE FORECAST VERY SIMILAR TO
GOING FCST FOR NEXT WEEKEND. HAVE LEFT BROAD AREAS OF POPS LATE
FRIDAY...INTO SATURDAY EVENING.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
CIGS SHOULD REMAIN IN THE VFR TO MVFR RANGE OVERNIGHT AS LARGE SFC
HIGH CENTERED TO THE NORTH OF PA SETTLES OVER THE STATE. SFC
WINDS WILL VEER FROM NW TO ENE BY 12Z TUES.
LOW MVFR TO IFR CIGS AND VSBYS WILL GRADUALLY SPREAD NWD ACROSS
THE AIRSPACE TUESDAY MORNING AND AFTERNOON AS A WEAK SFC TROF
MOVES EAST ACROSS THE MID ATLC. A PERIOD OF LLWS IS LIKELY TUES
EVE INTO TUE NIGHT WITH 40-50KT SWRLY WINDS A FEW TO SVRL KFT AGL.
SFC TEMPERATURES SHOULD SLOWLY CLIMB A FEW DEGS ABOVE FREEZING
TUES NGT OVER THE SE AIRFIELDS CHANGING ANY LINGERING PCPN TO
PLAIN RAIN...BUT THE COLD AIR APPEARS TO REMAIN ENTRENCHED OVER
THE INTERIOR SECTIONS WHICH SUGGESTS PATCHY -FZRA/-FZDZ IS
POSSIBLE. SOME LOCALLY DENSE FOG IS ALSO POSSIBLE ON THE RIDGES.
OUTLOOK...
WED...LOW CIGS TERMINAL-WIDE EARLY. PM IMPROVEMENT TO MVFR/VFR
LKLY E OF THE ALLEGHENY MTNS. HIGH CONFIDENCE IN PROLONGED IFR AT
JST.
THU...MVFR CIGS POSSIBLE WEST...OTHERWISE VFR WITH NO SIG WX.
FRI-SAT...MVFR/IFR CONDS LKLY IN RAIN OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
WEDNESDAY FOR PAZ004>006-012-037-041-042-045-046-049>053-058.
FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 AM EST
WEDNESDAY FOR PAZ017-024-025-033-034.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 7 AM EST
WEDNESDAY FOR PAZ010-011-018-019-026>028-035-036-056-057-059-
063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...LAMBERT
LONG TERM...CERU/GARTNER
AVIATION...GARTNER/STEINBUGL
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
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 556 PM CST WED DEC 3 2014/
UPDATE...
PLEASE SEE UPDATED 00Z AVIATION DISCUSSION BELOW.
AVIATION...
POOR FLYING CONDITIONS ONGOING AND EXPECTED TO WORSEN THROUGH THE
OVERNIGHT AS CURRENT MVFR/IFR CATEGORIES WILL DROP TO WIDESPREAD
IFR AND LIFR/VLIFR DUE TO EXTREMELY LOW CIGS AND VISIBILITIES.
FOG, SOME DENSE, NEAR KSAT/KSSF LOOKS POSSIBLE TO LIKELY DURING
06-14Z WITH INTERMITTENT -DZ. KAUS WILL LIKELY DROP BELOW 1SM
DURING SAME TIME FRAME WITH DENSE FOG ALSO POSSIBLE BUT NOT AS
LIKELY. KDRT IS VFR CURRENTLY BUT WILL BECOME IFR/LIFR DUE TO LOW
CIGS NEAR MIDNIGHT. SLIGHTLY HIGHER WINDS AT KDRT COULD PREVENT
1/4SM VISIBILITIES BUT WILL MONITOR TRENDS CLOSELY AS NUMEROUS
SHORT-TERM HI-RES GUIDANCE IS INDICATING WIDESPREAD FOG WITH
AREAS OF DENSE FOG, LEADING TO MODERATE TO HIGH CONFIDENCE.
/ALLEN/
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...33
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
911 PM CST WED DEC 3 2014
.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
&&
.AVIATION...
/ISSUED 530 PM CST WED DEC 3 2014/
/00Z TAFS/
CONCERNS...MVFR...IFR...AND LIFR CONDITIONS THROUGH THE PERIOD.
PERIODS OF FOG AND DRIZZLE.
MVFR CIGS BETWEEN 1-2 KFT AT THE START OF THE TAF PERIOD WILL
LOWER INTO IFR AND THEN LIFR HEIGHTS THROUGH THE NIGHT. EXPECT
LIFR/IFR CONDITIONS TO PREVAIL THROUGH THE MORNING WITH CIGS
EVENTUALLY LIFTING BETWEEN 1-3 KFT IN THE AFTERNOON HOURS.
HOWEVER...CIGS WILL LOWER AGAIN THURSDAY EVENING AND NIGHT. FOG
AND DRIZZLE WILL PREVAIL AT SOME TAF SITES THIS EVENING AND THEN
BECOME MORE WIDESPREAD OVERNIGHT...IMPROVING BY MIDDAY WHEN
CEILINGS START TO LIFT. AT TIMES...BRIEF PERIODS OF LIGHT RAIN MAY
OCCUR AT A TAF SITE THROUGH THE MORNING HOURS. THE WINDS THROUGH
THE PERIOD WILL BE FROM THE SOUTH TO SOUTHEAST...GENERALLY BELOW
10 KTS.
82/JLD
&&
.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 AUSTIN/SAN ANTONIO TX
1214 PM CST TUE DEC 2 2014
.AVIATION...
WENT WITH THE PESSIMISTIC FORECAST AS GFS HAS US BREAKING OUT OF
COLD AIR MUCH TOO SOON. NAM HAS A GOOD HANDLE ON COLD AIR RIGHT
NOW AND KEEPS THE CLOUDS AND OVERRUNNING SITUATION THROUGH
TOMORROW AS SURFACE RIDGE AXIS HOLDS ON NEAR THE ESCARPMENT. THIS
OVERRUNNING SHOULD KEEP CIGS IN THE MVFR THIS AFTERNOON...LOWERING
TO IFR OVERNIGHT TOWARD WED MORNING. HAVE INCLUDED DRIZZLE AND
LIGHT FOG TO ACCOMPANY THE CIGS. MAY SEE SOME SLIGHT IMPROVEMENT
BY TOMORROW AFTERNOON...BIT IT DEPENDS ON HOW QUICK THE ONSHORE
FLOW REESTABLISHES. THE LATEST NAM KEEPS US IN THE SOUP ALL THE
WAY THROUGH WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 1050 AM CST TUE DEC 2 2014/
UPDATE... /ADDING LIGHT SPRINKLES AND DRIZZLE FOR TODAY/
A QUICK UPDATE WAS ISSUED OVER MOST OF THE AREA TO INCLUDE
INTERMITTENT DRIZZLE AND SPRINKLES AS REPORTED AT CZO AND SEEN ON
RADAR IMAGERY. A SHALLOW DRY AIR LAYER REMAINS IN PLACE...SO
MOISTURE ACCUMULATION ON SURFACES SHOULD BE MINIMAL. MOST MODELS
SHOW SOME POTENTIAL FOR ADDITIONAL ACTIVITY FOR LATE TONIGHT...AND
THIS IS ALREADY ACCOUNTED FOR IN THE EARLY MORNING PACKAGE. WITH
THE ACTIVITY OCCURRING EARLY...THE AFTERNOON PACKAGE MAY NEED TO
CONSIDER THE POSSIBILITY OF THE SEPARATE EVENTS FILLING IN TO
BECOME CONTINUOUS. NO OTHER FORECAST CHANGES WERE MADE...AS THE
MORNING OBSERVATIONS WERE CONSISTENT WITH FORECAST TRENDS.
PREV DISCUSSION... /ISSUED 522 AM CST TUE DEC 2 2014/
AVIATION...
MODELS CONTINUE TO SHOW MVFR CIGS REMAINING IN PLACE THROUGHOUT
THE DAY ACROSS SOUTH CENTRAL TEXAS. THE WRF SIMULATED SATELLITE
AND MODEL CROSS SECTIONS KEEP THE AREA TERMINALS SOCKED IN THROUGH
THE DAY WITH LOWER END MVFR CIGS...THE HIGH RESOLUTION HRRR AND
SREF ALONG WITH THE MOS GUIDANCE ALL SHOW IMPROVEMENT DURING THE
AFTERNOON HOURS. HAVE TAKEN THE MIDDLE OF THE ROAD FOR THIS TAF
PACKAGE WITH CIGS IMPROVING TO HIGH END MVFR THIS AFTERNOON. FOR
THE MORNING HOURS ON WEDNESDAY EXPECT CIGS TO DROP AGAIN TO LOW
END MVFR OR HIGH END IFR. WINDS WILL BE OUT OF THE NORTH FOR MOST
OF TODAY BUT START TO TURN OUT OF THE EAST AND SOUTHEAST BY THIS
EVENING WITH SPEEDS BETWEEN 5 AND 10 KNOTS.
TREADWAY
PREV DISCUSSION... /ISSUED 322 AM CST TUE DEC 2 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
UPPER AIR ANALYSIS LAST EVENING SHOWED NORTHWESTERLY FLOW OVER
TEXAS BETWEEN A TROUGH OVER THE SOUTHEAST AND RIDGE ALONG THE WEST
COAST. AT THE SURFACE THE COLD FRONT HAS MOVED OFF SHORE AND HIGH
PRESSURE WAS CENTERED IN NORTH TEXAS. WINDS WERE FROM THE NORTH.
AREA SOUNDINGS AT 00Z SHOWED A STRONG FRONTAL INVERSION WITH A
SATURATED LAYER ABOVE WHICH WAS KEEPING SKIES CLOUDY. DURING THIS
PERIOD THE UPPER RIDGE WILL SHIFT TO THE EAST AND FLATTEN BRINGING
ZONAL FLOW OVER TEXAS. BELOW THIS RIDGE MOIST ISENTROPIC FLOW WILL
CONTINUE KEEPING SKIES CLOUDY THROUGH WEDNESDAY. THERE MAY ALSO BE
SUFFICIENT LIFT TO PRODUCE DRIZZLE WEDNESDAY MORNING OVER THE
EASTERN HALF OF THE CWA. AFTER A CHILLY DAY TODAY...TEMPERATURES
WILL RECOVER TO NEAR NORMAL.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
ZONAL FLOW WILL CONTINUE IN THE UPPER LEVELS THROUGH THE MIDDLE OF
THE WEEK. THE LOW LEVEL FLOW WILL REMAIN MOIST FROM THE SOUTHEAST
AND ISENTROPIC LIFT WILL INCREASE BRINGING A SLIGHT CHANCE FOR
RAIN TO THE EAST THURSDAY. RAIN CHANCES WILL SPREAD ACROSS THE
ENTIRE AREA THURSDAY NIGHT. FRIDAY A WEAK TROUGH WILL MOVE ACROSS
THE SOUTHERN PLAINS AND THIS WILL MEAN A LITTLE BETTER CHANCE FOR
RAIN. A COLD FRONT WILL MOVE THROUGH THE CWA SATURDAY CONTINUING
RAIN CHANCES. MODELS BEGIN TO DIVERGE EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 53 48 68 55 69 / 10 - - 10 20
AUSTIN BERGSTROM INTL AIRPORT 53 47 68 54 70 / 10 - - 10 20
NEW BRAUNFELS MUNI AIRPORT 54 49 68 55 71 / 10 - - 10 20
BURNET MUNI AIRPORT 52 46 65 53 66 / - - - 10 20
DEL RIO INTL AIRPORT 55 47 66 52 67 / - - - 10 10
GEORGETOWN MUNI AIRPORT 51 47 66 53 68 / 10 - - 10 20
HONDO MUNI AIRPORT 53 47 64 54 69 / 10 - - 10 10
SAN MARCOS MUNI AIRPORT 54 48 67 54 70 / 10 - - 10 20
LA GRANGE - FAYETTE REGIONAL 54 50 70 56 71 / 10 10 10 10 20
SAN ANTONIO INTL AIRPORT 54 50 66 57 70 / 10 - - 10 20
STINSON MUNI AIRPORT 54 49 67 57 71 / 10 - - 10 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...00
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1050 AM CST TUE DEC 2 2014
.UPDATE... /ADDING LIGHT SPRINKLES AND DRIZZLE FOR TODAY/
A QUICK UPDATE WAS ISSUED OVER MOST OF THE AREA TO INCLUDE
INTERMITTENT DRIZZLE AND SPRINKLES AS REPORTED AT CZO AND SEEN ON
RADAR IMAGERY. A SHALLOW DRY AIR LAYER REMAINS IN PLACE...SO
MOISTURE ACCUMULATION ON SURFACES SHOULD BE MINIMAL. MOST MODELS
SHOW SOME POTENTIAL FOR ADDITIONAL ACTIVITY FOR LATE TONIGHT...AND
THIS IS ALREADY ACCOUNTED FOR IN THE EARLY MORNING PACKAGE. WITH
THE ACTIVITY OCCURRING EARLY...THE AFTERNOON PACKAGE MAY NEED TO
CONSIDER THE POSSIBILITY OF THE SEPARATE EVENTS FILLING IN TO
BECOME CONTINUOUS. NO OTHER FORECAST CHANGES WERE MADE...AS THE
MORNING OBSERVATIONS WERE CONSISTENT WITH FORECAST TRENDS.
&&
.PREV DISCUSSION... /ISSUED 522 AM CST TUE DEC 2 2014/
AVIATION...
MODELS CONTINUE TO SHOW MVFR CIGS REMAINING IN PLACE THROUGHOUT
THE DAY ACROSS SOUTH CENTRAL TEXAS. THE WRF SIMULATED SATELLITE
AND MODEL CROSS SECTIONS KEEP THE AREA TERMINALS SOCKED IN THROUGH
THE DAY WITH LOWER END MVFR CIGS...THE HIGH RESOLUTION HRRR AND
SREF ALONG WITH THE MOS GUIDANCE ALL SHOW IMPROVEMENT DURING THE
AFTERNOON HOURS. HAVE TAKEN THE MIDDLE OF THE ROAD FOR THIS TAF
PACKAGE WITH CIGS IMPROVING TO HIGH END MVFR THIS AFTERNOON. FOR
THE MORNING HOURS ON WEDNESDAY EXPECT CIGS TO DROP AGAIN TO LOW
END MVFR OR HIGH END IFR. WINDS WILL BE OUT OF THE NORTH FOR MOST
OF TODAY BUT START TO TURN OUT OF THE EAST AND SOUTHEAST BY THIS
EVENING WITH SPEEDS BETWEEN 5 AND 10 KNOTS.
TREADWAY
PREV DISCUSSION... /ISSUED 322 AM CST TUE DEC 2 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
UPPER AIR ANALYSIS LAST EVENING SHOWED NORTHWESTERLY FLOW OVER
TEXAS BETWEEN A TROUGH OVER THE SOUTHEAST AND RIDGE ALONG THE WEST
COAST. AT THE SURFACE THE COLD FRONT HAS MOVED OFF SHORE AND HIGH
PRESSURE WAS CENTERED IN NORTH TEXAS. WINDS WERE FROM THE NORTH.
AREA SOUNDINGS AT 00Z SHOWED A STRONG FRONTAL INVERSION WITH A
SATURATED LAYER ABOVE WHICH WAS KEEPING SKIES CLOUDY. DURING THIS
PERIOD THE UPPER RIDGE WILL SHIFT TO THE EAST AND FLATTEN BRINGING
ZONAL FLOW OVER TEXAS. BELOW THIS RIDGE MOIST ISENTROPIC FLOW WILL
CONTINUE KEEPING SKIES CLOUDY THROUGH WEDNESDAY. THERE MAY ALSO BE
SUFFICIENT LIFT TO PRODUCE DRIZZLE WEDNESDAY MORNING OVER THE
EASTERN HALF OF THE CWA. AFTER A CHILLY DAY TODAY...TEMPERATURES
WILL RECOVER TO NEAR NORMAL.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
ZONAL FLOW WILL CONTINUE IN THE UPPER LEVELS THROUGH THE MIDDLE OF
THE WEEK. THE LOW LEVEL FLOW WILL REMAIN MOIST FROM THE SOUTHEAST
AND ISENTROPIC LIFT WILL INCREASE BRINGING A SLIGHT CHANCE FOR
RAIN TO THE EAST THURSDAY. RAIN CHANCES WILL SPREAD ACROSS THE
ENTIRE AREA THURSDAY NIGHT. FRIDAY A WEAK TROUGH WILL MOVE ACROSS
THE SOUTHERN PLAINS AND THIS WILL MEAN A LITTLE BETTER CHANCE FOR
RAIN. A COLD FRONT WILL MOVE THROUGH THE CWA SATURDAY CONTINUING
RAIN CHANCES. MODELS BEGIN TO DIVERGE EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 53 48 68 55 69 / 10 - - 10 20
AUSTIN BERGSTROM INTL AIRPORT 53 47 68 54 70 / 10 - - 10 20
NEW BRAUNFELS MUNI AIRPORT 54 49 68 55 71 / 10 - - 10 20
BURNET MUNI AIRPORT 52 46 65 53 66 / - - - 10 20
DEL RIO INTL AIRPORT 55 47 66 52 67 / - - - 10 10
GEORGETOWN MUNI AIRPORT 51 47 66 53 68 / 10 - - 10 20
HONDO MUNI AIRPORT 53 47 64 54 69 / 10 - - 10 10
SAN MARCOS MUNI AIRPORT 54 48 67 54 70 / 10 - - 10 20
LA GRANGE - FAYETTE REGIONAL 54 50 70 56 71 / 10 10 10 10 20
SAN ANTONIO INTL AIRPORT 54 50 66 57 70 / 10 - - 10 20
STINSON MUNI AIRPORT 54 49 67 57 71 / 10 - - 10 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...00
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
522 AM CST TUE DEC 2 2014
.AVIATION...
MODELS CONTINUE TO SHOW MVFR CIGS REMAINING IN PLACE THROUGHOUT
THE DAY ACROSS SOUTH CENTRAL TEXAS. THE WRF SIMULATED SATELLITE
AND MODEL CROSS SECTIONS KEEP THE AREA TERMINALS SOCKED IN THROUGH
THE DAY WITH LOWER END MVFR CIGS...THE HIGH RESOLUTION HRRR AND
SREF ALONG WITH THE MOS GUIDANCE ALL SHOW IMPROVEMENT DURING THE
AFTERNOON HOURS. HAVE TAKEN THE MIDDLE OF THE ROAD FOR THIS TAF
PACKAGE WITH CIGS IMPROVING TO HIGH END MVFR THIS AFTERNOON. FOR
THE MORNING HOURS ON WEDNESDAY EXPECT CIGS TO DROP AGAIN TO LOW
END MVFR OR HIGH END IFR. WINDS WILL BE OUT OF THE NORTH FOR MOST
OF TODAY BUT START TO TURN OUT OF THE EAST AND SOUTHEAST BY THIS
EVENING WITH SPEEDS BETWEEN 5 AND 10 KNOTS.
TREADWAY
&&
.PREV DISCUSSION... /ISSUED 322 AM CST TUE DEC 2 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
UPPER AIR ANALYSIS LAST EVENING SHOWED NORTHWESTERLY FLOW OVER
TEXAS BETWEEN A TROUGH OVER THE SOUTHEAST AND RIDGE ALONG THE WEST
COAST. AT THE SURFACE THE COLD FRONT HAS MOVED OFF SHORE AND HIGH
PRESSURE WAS CENTERED IN NORTH TEXAS. WINDS WERE FROM THE NORTH.
AREA SOUNDINGS AT 00Z SHOWED A STRONG FRONTAL INVERSION WITH A
SATURATED LAYER ABOVE WHICH WAS KEEPING SKIES CLOUDY. DURING THIS
PERIOD THE UPPER RIDGE WILL SHIFT TO THE EAST AND FLATTEN BRINGING
ZONAL FLOW OVER TEXAS. BELOW THIS RIDGE MOIST ISENTROPIC FLOW WILL
CONTINUE KEEPING SKIES CLOUDY THROUGH WEDNESDAY. THERE MAY ALSO BE
SUFFICIENT LIFT TO PRODUCE DRIZZLE WEDNESDAY MORNING OVER THE
EASTERN HALF OF THE CWA. AFTER A CHILLY DAY TODAY...TEMPERATURES
WILL RECOVER TO NEAR NORMAL.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
ZONAL FLOW WILL CONTINUE IN THE UPPER LEVELS THROUGH THE MIDDLE OF
THE WEEK. THE LOW LEVEL FLOW WILL REMAIN MOIST FROM THE SOUTHEAST
AND ISENTROPIC LIFT WILL INCREASE BRINGING A SLIGHT CHANCE FOR
RAIN TO THE EAST THURSDAY. RAIN CHANCES WILL SPREAD ACROSS THE
ENTIRE AREA THURSDAY NIGHT. FRIDAY A WEAK TROUGH WILL MOVE ACROSS
THE SOUTHERN PLAINS AND THIS WILL MEAN A LITTLE BETTER CHANCE FOR
RAIN. A COLD FRONT WILL MOVE THROUGH THE CWA SATURDAY CONTINUING
RAIN CHANCES. MODELS BEGIN TO DIVERGE EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 53 48 68 55 69 / - - - 10 20
AUSTIN BERGSTROM INTL AIRPORT 53 47 68 54 70 / - - - 10 20
NEW BRAUNFELS MUNI AIRPORT 54 49 68 55 71 / - - - 10 20
BURNET MUNI AIRPORT 52 46 65 53 66 / - - - 10 20
DEL RIO INTL AIRPORT 55 47 66 52 67 / - - - 10 10
GEORGETOWN MUNI AIRPORT 51 47 66 53 68 / - - - 10 20
HONDO MUNI AIRPORT 53 47 64 54 69 / - - - 10 10
SAN MARCOS MUNI AIRPORT 54 48 67 54 70 / - - - 10 20
LA GRANGE - FAYETTE REGIONAL 54 50 70 56 71 / - 10 10 10 20
SAN ANTONIO INTL AIRPORT 54 50 66 57 70 / - - - 10 20
STINSON MUNI AIRPORT 54 49 67 57 71 / - - - 10 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...12
SYNOPTIC/GRIDS...05
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1039 PM CST MON DEC 1 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
AND NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 1032 PM CST MON DEC 1 2014
HAD TO MOVE LAKE-ENHANCED CLOUDS AND FLURRIES A BIT FARTHER INLAND
THAN PREVIOUSLY THOUGHT...BUT THEY SHOULD GRADUALLY PULL OUT TUES
MORNING AS LLVL WINDS BECOME SSW. GIVEN A VERY SHALLOW LAYER OF
MOISTURE...MARGINAL INSTABILITY AND POOR ORGANIZATION ON RADAR...
HAVE BACKED OFF ON POPS A BIT AND JUST MENTIONED FLURRIES.
&&
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 246 PM CST MON DEC 1 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE MOVING INTO THE NORTHERN MISSISSIPPI VALLEY EARLY THIS
AFTERNOON. WINDS ARE GRADUALLY DIMINISHING AS THIS HIGH PRESSURE
DRAWS CLOSER TO THE REGION...BUT TEMPERATURES HAVE STRUGGLED TO RISE
SO FAR TODAY. WIND CHILLS REMAIN BETWEEN 0 AND 10 DEGREES BELOW
ZERO. CLEAR SKIES EXIST ALL THE WAY ACROSS THE NORTHERN
PLAINS...BUT THE NEXT SYSTEM IS MOVING ACROSS THE PACIFIC
NORTHWEST. FORECAST CONCERNS ARE THREE FOLD...AND INCLUDE MIN TEMPS
TONIGHT...SMALL LAKE EFFECT SNOW CHANCES LATE TONIGHT INTO TUESDAY
MORNING...AND LIGHT SNOW CHANCES OVER N-C WISCONSIN FOR TUESDAY
AFTERNOON.
TONIGHT...ARCTIC HIGH PRESSURE WILL QUICKLY SLIDE ACROSS THE REGION
THIS EVENING AND HEAD TOWARDS NEW ENGLAND BY LATE TONIGHT. THOUGH
THE COLDEST AIR WILL HAVE DEPARTED THE REGION TO THE EAST...CLEAR
SKIES AND LIGHT WINDS WILL PROMOTE TUMBLING TEMPERATURES THIS
EVENING. ALWAYS DIFFICULT TO DETERMINE HOW LOW TO GO IN THESE
INSTANCES BECAUSE THE COLD SPOTS CAN QUICKLY FALL 20 DEGREES IN JUST
A FEW HOURS. UPSTREAM OBS THIS MORNING SHOWED PLENTY OF READINGS IN
THE 10 TO 15 BELOW RANGE AND THATS A GOOD START FOR THE COLD SPOTS
OF N-C WISCONSIN. AS THE SURFACE HIGH EXITS...THE SURFACE PRESSURE
GRADIENT RAPIDLY TIGHTENS AND SHOULD SEE TEMPERATURES RISE LATE IN
THE EVENING AND OVERNIGHT...WHEN CIRRUS ARRIVES.
ADDITIONALLY...SURFACE TO 950MB WINDS WILL SHIFT TO THE SOUTHEAST
OVER LAKE MICHIGAN OVERNIGHT WHICH WILL LIKELY BRING STRATO-CU AND
FLURRIES TO MUCH OF EASTERN WISCONSIN. KEPT A SMALL ACCUMULATION
OVER THE DOOR...BUT THINKING ONLY A DUSTING AT BEST DUE TO THE VERY
DRY AIRMASS IN PLACE. LOWS 0 TO 5 ABOVE OVER THE FOX VALLEY AND LAKE
SHORE.
TUESDAY...AS LAKE EFFECT CLOUDS AND FLURRIES IMPACT EASTERN
WISCONSIN...MID AND HIGH CLOUDS WILL BE SPREADING OVERHEAD DURING
THE MORNING AHEAD OF A SHEARED SHORTWAVE. THINK THE CLOUDS AND
FLURRIES WILL BECOME INCREASINGLY CONFINED TO THE LAKE SHORE AS LOW
LEVEL WINDS VEER TO THE SOUTH AND THEN SSW DURING THE MORNING. DO
NOT SEE MUCH POTENTIAL FOR SEEDER-FEEDER PROCESSES DUE TO A VERY DRY
LAYER BETWEEN 900-700MB. AS THE SHORTWAVE DRAWS CLOSER DURING THE
AFTERNOON...PROGGED SOUNDINGS OVER N-C WISCONSIN SHOW THAT DRY WEDGE
ERODING. WITH FORCING FROM DECENT MID-LEVEL FGEN...CAN SEE A LIGHT
SNOW CHANCE FOR THE NORTH BY MID AFTERNOON. WILL INCREASE PRECIP
CHANCES SOME. HIGHS RETURNING TO THE 20S.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 246 PM CST MON DEC 1 2014
WINTER IS TAKING A VACATION FOR THE NEXT WEEK OR SO
AS UPPER HEIGHTS RISE AND FLOW BECOMES ZONAL. OTHER THAN SOME
LIGHT SNOW OR FLURRIES WITH A WEAK COLD FRONT TUESDAY NIGHT IT
LOOKS LIKE IT WILL BE DRY THROUGH THE REMAINDER OF THE WEEK.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1032 PM CST MON DEC 1 2014
LAKE-EFFECT STRATUS (MVFR CIGS) AND FLURRIES WILL AFFECT THE
FOX VALLEY AND LAKESHORE AREAS OVERNIGHT INTO TUESDAY MORNING.
THESE CLOUDS SHOULD RETREAT BACK TOWARDS THE LAKE BY MIDDAY
TUESDAY. ELSEWHERE...MID AND HIGH CLOUDS WILL BE ON THE INCREASE
OVERNIGHT INTO TUESDAY. AN UPPER LEVEL DISTURBANCE WILL BRING SCT
SNOW SHOWERS AND ASSOCIATED MVFR CONDITIONS TO THE REGION DURING
THE LATE AFTERNOON AND EVENING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
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:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
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:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
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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 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 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...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
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 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 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 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 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 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 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
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
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
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:
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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:
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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:
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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 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 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 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
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 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.
&&
$$
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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.
&&
$$
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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
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
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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 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 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
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 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 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 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
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
[top]
Area Forecast Discussion
National Weather Service Spokane WA
239 PM PST THU DEC 4 2014
.SYNOPSIS...
A series of storm systems will bring a wintry mix of precipitation
to the Pacific Northwest tonight and on through a good portion of
the weekend. 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...Highlights in effect to address the freezing rain and
the resulting ice accumulation. Idaho and Washington Palouse was
again added to ongoing freezing rain advisories as that area never
quite got rid of its cold air at low levels this warmer moist air
is overrunning and producing this wintry mix which includes snow
and some rain in areas that did warm up enough to allow the
transition. Otherwise majority of pavement temperatures across the
northern two thirds of the forecast area roughly just as cold.
Have relied on the Hourly HRRR runs for most of the day to
maintain confidence in keeping the freezing rain highlights
associated with the next incoming weather disturbance which is
very pronounced in the current radar mosaic over South Central
Washington and North Central Oregon. Some locations such as
Wenatchee airport have broke slightly above freezing but this
trend is not widespread and with the considerable amount of ice
accumulation resulting from this system passing there the ice
storm warning remains in effect tonight. /Pelatti
Friday through Sunday...A weak wave will track across the northwest/northern
mountains Friday morning...as high pressure builds into the
region. Another fairly fast moving short wave disturbance will
move through the ridge on Saturday. This will be followed by high
pressure re-building Saturday night and Sunday for a drying trend.
Temperatures will be on the increase with high warming into the
mid 30s to mid 40s both Friday and Saturday.
*Precipitation: The combination of the weak wave moving through
the northern zones will combine with isentropic up-glide and
orographic lift for precipitation to linger across the northern
zones through the day on Friday. Otherwise the precipitation
chances will be winding down. There will be a brief lull in the
action Friday night as the ridge of high pressure moves into the
region, but there will still be some light precipitation chances
possible across the northern zones. The next wave will tap into
another round of deep Pacific moisture Saturday morning and bring
a quick shot of moisture to the region. Isentropic up-glide will
be on the increase across the western zones around 12z with the
cold front following less than 6 hours later. The low level flow
will be southeast to south Saturday morning eliminating any
Cascade shadowing for the lowers east slopes and the deep
basin...then the floe will become south-southwest through the
day. Drying from the west is expected before mid day, but
precipitation will linger through Saturday evening for the
Panhandle. Storm total precipitation will range from around a
tenth for the lower elevations and possibly up to a quarter 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.
*Precipitation type: This is a much more difficult forecast
compared to the precipitation. Warm air advection Friday is
expected to increase snow levels through the day. However cold
air trapped up against the cascades and in many of the deeper
valleys and northern mountain valleys will be tougher to scour
out. Some areas of freezing rain were kept in the forecast from
about the West plains west into the valleys of the Cascades early
Friday morning. As the warm air continues to advect north Friday
morning precipitation in some of the stubborn valleys along the
Columbia river and the northern mountains will see a period of
light freezing precipitation before that to turns over the rain.
This will be watched closely for any additional highlights
needed. By Saturday we can expect valley rain and mountain snow.
The exception will most likely be the Methow valley where
precipitation should stay as all snow. Tobin
Sunday night through Thursday: A ridge pattern will be in place to
start this period. Sunday night is expected to remain dry for most
of the region with some spill over the Cascades bringing some
snow showers to the higher elevations. As the ridge pushes east,
a warm moist southwesterly flow will setup for the beginning of
the week and last through the end period. The models are in fairly
good agreement for this scenario. The warming trend will keep this
a rain event for the most of the Inland Northwest. The only areas
expected for snow will be elevations above 5000 feet. This will last
through Thursday before models are indicating the next wave of
cold air to push into the region. Temperatures for this period
will be on the high side of the season normals with highs in the
mid 40s and lows in the mid 30s. /JDC
&&
.AVIATION...
18Z TAFS: Wintry mix of precipitation consisting of light
rain, snow, and freezing rain will be troublesome for the
aviation area for the next 24 hours or more. Generally this mix
will be south of a line from Lake Chelan to Deer Park. Low
ceilings and visibilities, down to IFR at times, will continue to
be the issue with the mixture of precipitation that falls.
Locations in the vicinity of KEAT Generally south of Lake Chelan
and to the west of KEPH will see the intensity of ice accumulation
pick up overnight tonight into early Friday morning. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 29 39 33 41 32 39 / 80 40 10 80 10 10
Coeur d`Alene 29 40 34 41 33 40 / 80 40 10 80 20 0
Pullman 31 43 37 44 33 44 / 80 20 10 90 10 10
Lewiston 36 45 40 47 35 45 / 70 20 10 70 10 0
Colville 28 37 34 40 31 39 / 80 30 30 60 20 0
Sandpoint 30 38 34 40 32 40 / 80 50 20 80 30 10
Kellogg 31 39 34 38 33 39 / 90 60 10 90 40 0
Moses Lake 29 38 32 41 29 39 / 70 20 50 70 10 0
Wenatchee 29 37 34 41 30 38 / 80 40 60 60 0 10
Omak 25 35 32 38 26 35 / 70 40 50 70 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Freezing Rain Advisory until 4 AM PST Friday for Idaho Palouse.
Freezing Rain Advisory until 4 AM PST Friday for Coeur d`Alene
Area.
WA...Air Stagnation Advisory until 4 AM PST Saturday for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
ICE Storm Warning until 10 AM PST Friday for East Slopes
Northern Cascades-Waterville Plateau-Wenatchee Area.
Freezing Rain Advisory until 4 AM PST Friday for Washington
Palouse.
Freezing Rain Advisory until 4 AM PST Friday for Spokane Area.
Freezing Rain Advisory until 7 AM PST Friday 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