Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/23/15

AREA FORECAST DISCUSSION

NWS RENO NV

943 PM PST SUN DEC 20 2015

.UPDATE...

BUOYS AT LAKE TAHOE ARE SHOWING A DECREASE IN WIND SPEEDS LATE
THIS EVENING A LITTLE FASTER THAN ORIGINALLY FORECAST. THIS COULD
BE IN RESPONSE TO PRECIPITATION MAKING ITS WAY INTO THE TAHOE
BASIN DAMPENING THE WINDS. THINK THIS WILL BE THE CASE THROUGH THE
REMAINDER OF THE NIGHT BEFORE INCREASING PRESSURE/THERMAL GRADIENT
STARTS TO INCREASE THE WINDS AGAIN MONDAY. THUS...WE WILL CANCEL
THE LAKE WIND ADVISORY FOR LAKE TAHOE A LITTLE EARLY TONIGHT.

ELSEWHERE...LIGHT SNOW CONTINUES FOR THE TAHOE BASIN NORTH INTO
PARTS OF SIERRA AND PLUMAS COUNTIES. THIS PRECIPITATION IS NOT
HEAVY BUT HAS BEEN CAUSING TRAVEL PROBLEMS IN PARTS OF THE TAHOE
BASIN...ESPECIALLY INTERSTATE 80. THIS IS JUST THE PRECURSOR TO A
MUCH MORE SUBSTANTIAL PUSH OF MOISTURE INTO THE REGION MONDAY
THROUGH TUESDAY. ADJUSTMENTS WILL LIKELY BE NEEDED TO FORECASTS
OVER THE NEXT 36 HOURS...BUT FOR NOW WE WILL MAKE NO SIGNIFICANT
CHANGES TO THE NEXT 12 HOURS OUTSIDE OF THE WINDS. 20

.PREVIOUS DISCUSSION... /ISSUED 351 PM PST SUN DEC 20 2015/

SYNOPSIS...

ACTIVE WINTER PATTERN CONTINUES THROUGH THE END OF THE WEEK. EACH
STORM WILL BRING SNOW, WIND, AND THE POTENTIAL FOR TRAVEL
HEADACHES. THE MAIN PERIODS OF CONCERN WILL BE MONDAY INTO TUESDAY
AND CHRISTMAS EVE INTO CHRISTMAS DAY. AT THIS POINT IT APPEARS
THAT WEDNESDAY WILL BE THE BEST TRAVEL DAY IF YOUR PLANS INCLUDE
CROSSING THE SIERRA.

SHORT TERM...

THERE HAVE BEEN SIGNIFICANT CHANGES EARLY THIS WEEK AS MODELS HAVE
BECOME EXTREMELY WET FROM MONDAY THROUGH TUESDAY AFTERNOON.
MOISTURE FLUX OFF THE PACIFIC HAS INCREASED SEVERAL FOLD WITH AN
ANOMALOUS STREAM SLAMMING INTO THE SIERRA FOR 12-24 HOURS. THIS
HAS CORRELATED TO A LARGE INCREASE IN FORECAST SNOW TOTALS FROM
WESTERN LASSEN COUNTY SOUTH THROUGH MONO COUNTY. WINTER STORM
WARNINGS HAVE BEEN ISSUED GENERALLY STARTING MONDAY MORNING AND
CONTINUING THROUGH TUESDAY MORNING FROM LASSEN COUNTY THROUGH THE
TAHOE BASIN. A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR MONO
COUNTY WITH FROM LATE MONDAY MORNING THROUGH TUESDAY AFTERNOON.

..PRECIPITATION...
A BROAD 1-1.5 INCH PWAT PLUME WILL STREAM INTO THE REGION EARLY
MONDAY AND PERSIST THROUGH TUESDAY AFTERNOON. THIS WILL ALLOW FOR
AN EXTENDED PERIOD OF SNOW TO FALL MAINLY IN THE SIERRA AND
NORTHERN ZONES NEAR THE OREGON BORDER. SNOW LEVELS WILL START LOW
AROUND 5000-5500 FT BEFORE RISING TO AROUND 7000 FT THROUGH
TUESDAY MORNING. THE RESULT WILL BE COPIOUS SNOWFALL ABOVE 7000
FEET IN THE SIERRA SERIOUSLY IMPACTING TRAVEL OVER AREA PASSES.
ALL SAID AND DONE...THERE COULD BE 2-3 FEET ABOVE 7000 FEET IN THE
TAHOE BASIN.

THERE IS A LOT OF UNCERTAINTY BELOW 7000 FEET ESPECIALLY IN THE
TAHOE BASIN AND AROUND TRUCKEE. SINCE SNOW LEVELS START FAIRLY
LOW, THERMAL PROFILES WILL LIKELY GO ISOTHERMAL WITH SNOW MELT
DELAYING THE LIFTING OF SNOW LEVELS. THEREFORE, 4 TO 8 INCHES OF
HEAVY WET SNOW WILL BE POSSIBLE DOWN TO LAKE LEVEL. HOWEVER, IF
SNOW RATES DECREASE, SNOW LEVELS WILL RISE MORE RAPIDLY AND SNOW
WILL SWITCH TO RAIN.

SIMILARLY, LASSEN AND PLUMAS WILL SEE AN INFLUX OF MOISTURE. SNOW
TOTALS HAVE INCREASE MAINLY WEST OF HIGHWAY 395 ABOVE 5500 FT - 8
TO 14 INCHES POSSIBLE. LOWER TOTALS ARE EXPECTED EAST OF HIGHWAY
395 AND MORE SEQUESTERED TO NORTHERN LASSEN COUNTY - 4 TO 8 INCHES
POSSIBLE.

DUE TO SHADOWING, ACCUMULATIONS WILL BE LOWER FOR MONO COUNTY.
GENERALLY EXPECTING 6 TO 18 INCHES MAINLY WEST OF HIGHWAY 395 AND
ABOVE 7500 FEET. THE HIGHEST TOTALS WILL BE AROUND MAMMOTH
MOUNTAIN AND THE HIGHER SIERRA.

WESTERN NEVADA WILL BE LARGELY SHADOWED AND LITTLE SNOW
ACCUMULATION IS LIKELY. LOCATIONS DOWN TO 5500 FEET COULD SEE AN
INCH OR TWO, BUT THE CHARACTER WILL BE WET AND LESS LIKELY TO
CAUSE WIDESPREAD TRAVEL CONCERNS. EXPECT RAIN BELOW 5500 FEET.

STILL EXPECTING CONSISTENT ACCUMULATIONS FOR THE SURPRISE VALLEY
AND NORTHERN WASHOE COUNTY. 2 TO 6 INCHES WILL BE MOST LIKELY
WITH ABOUT A 25% CHANCE OF HIGHER TOTALS UP TO 8 INCHES.

PRECIPITATION WILL TAPER OFF TUESDAY AFTERNOON WITH PRIMARY
MOISTURE SHIFTING SOUTH. SNOW LEVELS WILL DROP AS FLOW ALOFT TURNS
MORE NORTHERLY AND LINGERING SCATTERED SNOW SHOWERS CAN BE
EXPECTED FOR THE SIERRA FROM THE TAHOE BASIN TO THE OREGON BORDER.

..WINDS...
IT IS BREEZY AROUND THE REGION TODAY WITH GUSTS 20-35 MPH FOR
VALLEYS/SLOPES AND 45-60 MPH FOR NORTHERN SIERRA RIDGES AND THE
HIGHER PEAKS OF FAR WESTERN NEVADA. THERE IS A LAKE WIND ADVISORY IN
PLACE FOR LAKE TAHOE THROUGH EVENING. WINDS HAVE INCREASED TO 10-20
MPH ON THE LAKE PER BUOYS. WITH WINDS INCREASING OVER THE TAHOE
CREST AND THE 22Z HRRR INDICATES HIGHER WINDS FOR LATE THIS
AFTERNOON AND EARLY EVENING ON THE LAKE, WINDS MAY RAMP UP A BIT
MORE SHORTLY.

MOVING ON TO TOMORROW, WINDS ALOFT WILL INCREASE WITH 700 MB WINDS
OF 50-75 KTS IN THE NAM IN THE AFTERNOON. NAM CROSS-SECTIONS HINT AT
SOME DOWNSLOPING WINDS MONDAY AFTERNOON IN THE LEE OF THE CARSON
RANGE AND WINDS ALOFT DO NOT INCREASE ABOVE 700 MB SO SHADOWING
SHOULD BE STRONG. WITH ALL THIS IN MIND, WE EXPECT WINDS GUSTING TO
65-70 MPH IN THE FOOTHILLS WITH WIDESPREAD GUSTS 40-55 MPH. STRONG
WINDS MAY EXTEND OUT TO ALONG HIGHWAY 50 IN CHURCHILL COUNTY FROM
ABOUT FALLON WESTWARD, AND SOUTH ALONG HIGHWAY 395 TO ABOUT
BRIDGEPORT.

FOR THE TAHOE BASIN, NORTHEAST CALIFORNIA AND FAR NORTHWEST NEVADA,
INCREASING PRECIPITATION MONDAY AFTERNOON IS EXPECTED TO STABILIZE
THE ATMOSPHERE ENOUGH TO HOLD WINDS DOWN CONSIDERABLY. HOWEVER, IT
WILL STILL BE RATHER BREEZY GIVEN A RESPECTABLE SURFACE GRADIENT
(SUB-990 MB MSLP LOW ALONG THE OREGON-WASHINGTON BORDER), ESPECIALLY
DURING PERIODS OF SLACKENED PRECIPITATION.

TUESDAY, WINDS SHOULD RELAX CONSIDERABLY ALTHOUGH IT WILL REMAIN
BREEZY. SNYDER

LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...

CONFIDENCE CONTINUES TO INCREASE FOR AN ALL SNOW EVENT STARTING LATE
WEDNESDAY NIGHT FOR NORTHEAST CA TO THE SIERRA CREST WEST OF TAHOE,
AND SPREADING ACROSS THE REMAINDER OF THE REGION ON THURSDAY. SNOW
AMOUNTS WILL NOT BE EXCESSIVE DUE TO THE FAST MOVEMENT OF THIS STORM
SYSTEM, BUT LATEST GUIDANCE IS HINTING AT UNSTABLE CONDITIONS
ALLOWING FOR BANDS OF SNOW TO EFFICIENTLY SPREAD ACROSS WESTERN NV,
WITH ACCUMULATIONS MORE LIKELY EVEN IN LOWER VALLEYS OF WEST CENTRAL
NV. SNOWFALL RATES WILL ALSO BE SIGNIFICANT, WITH UP TO 2 INCHES PER
HOUR AT TIMES. THE BEST RECOMMENDATION FOR CHRISTMAS HOLIDAY TRAVEL
IN THE SIERRA AND WESTERN NV IS TO COMPLETE THE TRIP ON WEDNESDAY IF
POSSIBLE.

EARLY SNOWFALL PROJECTIONS FOR EASTERN CA REMAIN SIMILAR TO OUR
THINKING FROM YESTERDAY, AS AREAS WEST OF TAHOE TO THE SIERRA CREST
MAY RECEIVE OVER 1 FOOT OF SNOWFALL. AT LEAST 6 INCHES OF SNOW ARE
POSSIBLE FROM NORTHEAST CA TO MONO COUNTY WEST OF HIGHWAY 395,
INCLUDING THE TAHOE BASIN. THE MAIN ADJUSTMENT WAS FOR THE
SUSANVILLE-RENO-CARSON CITY VICINITY WHERE WE COULD RECEIVE 3-6
INCHES, WITH A COUPLE OF INCHES POSSIBLE EAST TO THE HIGHWAY 95
CORRIDOR.

BY LATE THURSDAY, THE STEADY SNOW WILL QUICKLY WIND DOWN ACROSS THE
REGION, WITH SOME BANDS OF SNOW SHOWERS LINGERING MAINLY SOUTH OF
SUSANVILLE-FALLON INTO THE EVENING.

ANY SNOW THAT FALLS THURSDAY NIGHT WILL STICK AROUND FOR CHRISTMAS
DAY AND NEXT WEEKEND AS COLD CONDITIONS WILL PREVAIL. HIGHS ARE ONLY
EXPECTED TO REACH THE LOWER 30S IN LOWER ELEVATIONS AND 20S NEAR THE
SIERRA. THERE IS LOWER POTENTIAL FOR A SECONDARY SHORTWAVE BRINGING
MORE ORGANIZED AREAS OF SNOW TO THE REGION, BUT FLURRIES AND LIGHT
SNOW SHOWERS WILL REMAIN POSSIBLE THROUGH THE DAY.

FOR NEXT WEEKEND, DRY CONDITIONS ARE EXPECTED AS RIDGE BUILDS OVER
THE REGION WITH CLEAR TO PARTLY CLOUDY SKIES. CHILLY TEMPERATURES
WILL CONTINUE WITH LOWS DROPPING TO THE SINGLE DIGITS AND LOWER
TEENS BOTH FRIDAY AND SATURDAY NIGHTS, WITH EVEN COLDER TEMPS NEAR
OR BELOW ZERO POSSIBLE IN LOWER VALLEYS IF SNOW COVER IS PRESENT.
HIGHS BOTH SATURDAY AND SUNDAY WILL REMAIN BELOW NORMAL IN THE 20S
AND 30S, WITH VALLEY INVERSIONS LIKELY. A SHORT PERIOD OF STRONGER
NORTH TO NORTHEAST RIDGE WINDS REMAINS POSSIBLE ACROSS THE SIERRA
FRIDAY NIGHT INTO SATURDAY MORNING. MJD

AVIATION...

MULTIPLE WEATHER RELATED IMPACTS FOR AVIATION ARE EXPECTED THROUGH
TUESDAY. FOR MONDAY, THE PRIMARY IMPACTS WILL BE INCREASED WINDS
WITH GUSTS 35-45 KT AT MOST TERMINALS, AND SIERRA RIDGE GUSTS 70-85
KT. THE STRONG RIDGE GUSTS WILL CONTINUE INTO TUESDAY, WITH ONLY A
SLIGHT DECREASE IN WIND SPEEDS FOR LOWER ELEVATIONS. THESE WINDS
WILL PRODUCE TURBULENT FLYING CONDITIONS ACROSS THE SIERRA AND
WESTERN NV.

LIGHT SNOW SHOWERS WILL BE POSSIBLE AT THE SIERRA TERMINALS MONDAY,
WITH A HIGHER POTENTIAL FOR SNOW ACCUMULATIONS ON RUNWAYS ALONG WITH
IFR OR WORSE CIGS/VSBY MONDAY NIGHT INTO TUESDAY. FOR WESTERN NV,
ISOLATED -SHRA ARE POSSIBLE MONDAY, WITH SOME INCREASE IN SHOWER
POTENTIAL BY TUESDAY. WHILE CIGS/VSBY WILL GENERALLY REMAIN IN THE
VFR CATEGORY FOR KRNO-KCXP (EXCEPT MVFR AT TIMES IN HEAVIER SHOWERS)
MOUNTAIN OBSCURATIONS ARE LIKELY TO PERSIST FOR MUCH OF MONDAY AND
TUESDAY. ICING WILL GENERALLY BE MIXED WITH HIGHEST ACCRETION
FROM THE SURFACE TO AROUND 14000 FT MSL. MJD

.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY FROM 10 AM MONDAY TO 4 AM PST TUESDAY
NVZ005.

WINTER STORM WARNING FROM 10 AM MONDAY TO 10 AM PST TUESDAY
NVZ002.

WIND ADVISORY FROM 9 AM TO 10 PM PST MONDAY NVZ003.

LAKE WIND ADVISORY FROM 9 AM TO 5 PM PST MONDAY FOR PYRAMID LAKE
IN NVZ004.

CA...WINTER STORM WARNING FROM 4 AM MONDAY TO 4 AM PST TUESDAY ABOVE
5500 FEET FOR CAZ071.

WINTER WEATHER ADVISORY FROM 10 AM MONDAY TO 4 AM PST TUESDAY
CAZ070.

WINTER WEATHER ADVISORY FROM 10 AM MONDAY TO 4 PM PST TUESDAY
CAZ073.

WINTER STORM WARNING FROM 10 AM MONDAY TO 10 AM PST TUESDAY
CAZ072.

FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)

AREA FORECAST DISCUSSION

NWS TAMPA BAY RUSKIN FL

910 PM EST TUE DEC 22 2015

.UPDATE...
01Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A BROAD UPPER TROUGH
IN PLACE OVER MUCH OF THE CONUS FROM THE PACIFIC COAST TO THE MS
VALLEY. WEAK RIDGING EXISTS OVER THE WESTERN ATLANTIC...AND WILL
BE EXPANDING WESTWARD TO INFLUENCE OUR LOCAL WEATHER MORE AND MORE
THROUGH THE MIDDLE PORTION OF THE WEEK. AT THE SURFACE...OUR
REGION LIES WITHIN A BROAD MOIST SOUTHERLY FLOW REGIME AROUND THE
WESTERN PERIPHERY OF RIDGING OVER THE WESTERN ATLANTIC. THE
CONTINUED SOUTHERLY FLOW IS BRINGING ABUNDANT LOW LEVEL MOISTURE
AND RATHER HUMID CONDITIONS FOR DECEMBER. WHILE A FEW SHOWERS
DEVELOPED OVER THE FLORIDA PENINSULA THIS PAST AFTERNOON...IT WAS
A WASHOUT...WITH WIDESPREAD RAIN...JUST TO THE NORTHWEST OF OUR
ZONES ACROSS THE BIG BEND AND FLORIDA PANHANDLE.

TODAY WAS ABOUT THE CLOSEST THAT THIS MORE ORGANIZED RAIN WAS
GOING TO COME TO OUR AREA. WITH THE UPPER RIDGE STRENGTHENING
OVERHEAD THE NEXT COUPLE OF DAYS...WE CAN EXPECT ANY SIGNIFICANT
RAIN TO REMAIN OFF TO OUR NORTH AND NORTHWEST.

WHILE NO ORGANIZED RAINFALL IS EXPECTED...THE FORECAST REMAINS
UNSEASONABLY WARM. SEE LITTLE REASON NOT TO ANTICIPATE
TEMPERATURES INTO THE LOWER/MIDDLE 80S AWAY FROM THE BEACHES
THROUGH THE NEXT SEVERAL DAYS (AT LEAST).

THE FORECAST IS GOING TO BECOME A "BROKEN RECORD" THROUGH THE
REMAINDER OF THE WEEK. WELL ABOVE NORMAL TEMPERATURES...AND JUST A
SLIGHT CHANCE OF AN AFTERNOON INSTABILITY SHOWER EACH DAY.

.AVIATION...
GENERAL VFR CONDITIONS ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA
THIS EVENING...ALTHOUGH PLENTY OF LOW LEVEL MOISTURE IN PLACE...
THE DEEPER INTO THE OVERNIGHT WE GET...THE POTENTIAL FOR AREAS OF
IFR/MVFR CIGS/VIS WILL BE INCREASING. HAVE ALL TERMINALS IN
PREVAILING MVFR AFTER 07-08Z...WITH ANY SPOT POSSIBLY SEEING A
PERIOD OF IFR RESTRICTIONS IN THE HOURS SURROUNDING SUNRISE. CIGS
SHOULD LIFT WEDNESDAY MORNING...WITH GENERAL VFR CONDITIONS AND
GUSTY SOUTHERLY WINDS DEVELOPING FOR LATE MORNING AND AFTERNOON.

.MARINE...
HIGH PRESSURE OVER THE WESTERN ATLANTIC CONTINUES TO RIDGE
WESTWARD OVER THE FLORIDA PENINSULA AND EASTERN GULF THROUGH THE
END OF THE WEEK. SOUTHEASTERLY FLOW WILL PREVAIL...HOWEVER WITH
A FAIRLY WEAK GRADIENT ACROSS THE AREA...WINDS SHOULD GENERALLY
REMAIN BELOW 15 KNOTS. THIS PATTERN WILL LIKELY HOLD THROUGH THE
UPCOMING WEEKEND...WITH THE NEXT POTENTIAL COLD FRONT TO IMPACT
THE EASTERN GULF OF MEXICO NOT ARRIVING UNTIL THE EARLY PART OF
NEXT WEEK.

.PRELIMINARY POINT TEMPS/POPS...
TPA 71 82 69 84 / 20 10 10 10
FMY 71 85 71 86 / 20 10 10 10
GIF 70 85 70 85 / 40 10 10 10
SRQ 71 82 70 83 / 20 10 10 10
BKV 70 85 68 85 / 20 10 10 10
SPG 70 82 71 83 / 20 10 10 10

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&

UPDATE/AVIATION/MARINE...14/MROCZKA

AREA FORECAST DISCUSSION

NWS CHARLESTON SC

648 PM EST TUE DEC 22 2015

.SYNOPSIS...
UNSEASONABLY WARM AND MOIST AIR WILL AFFECT THE AREA WHILE A
SERIES OF UPPER LEVEL DISTURBANCES IMPACT THE SOUTHEAST THROUGH
MID WEEK. HIGH PRESSURE AND UNSEASONABLY WARM TEMPERATURES WILL
PREVAIL LATE WEEK THROUGH EARLY NEXT WEEK.

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A BAND OF LIGHT SHOWERS MOVING INTO SOUTHEAST GEORGIA EARLY THIS
EVENING APPEARS TO BE ALIGNED WITH A WEAK AREA MULTI-SURFACE
ISENTROPIC ASSENT. LATEST RAP OUTPUT SHOWS THIS AREA OF SHOWERS
PROPAGATING INTO SOUTHEAST SOUTH CAROLINA AND WEAKENING AS
ASSENT DIMINISHES AND WEAK ISENTROPIC DOWNGLIDE COMMENCES.
MODIFIED POPS TO ACCOUNT FOR CURRENT RADAR TRENDS WITH POPS
50-70 PERCENT PREVAILING FOR THE NEXT FEW HOURS.

HIGH RESOLUTION GUIDANCE KEEPS THE BULK OF ANY ADDITIONAL
ISENTROPIC ASSENT DISPLACED TO THE WEST CLOSER TO THE DECAYING
WARM FRONT THAT EXTENDS ACROSS CENTRAL GEORGIA...THROUGH THE CSRA
TO NEAR COLUMBIA. THIS IS WHERE THE BETTER CHANCES FOR MEASURABLE
RAIN WILL GRADUALLY TRANSITION. INDEED...THE LATEST MRMS RALAS
PRODUCT SHOWS SHOWER ACTIVITY OVER NORTHERN FLORIDA GRADUALLY
WEAKENING WHERE ISENTROPIC DOWNGLIDE IS ALREADY OCCURRING. THIS
LEADS TO LOWER CONFIDENCE ON EXACTLY HOW MUCH MEASURABLE RAIN WILL
OCCUR OVERNIGHT ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA. POPS AND QPF HAVE BEEN LOWERED FROM MIDNIGHT ON TO
ACCOUNT FOR DRIER TRENDS NOTED IN BOTH THE H3R AND RAP. IT WILL
REMAIN A WARM AND HUMID NIGHT WITH LOWS IN THE LOWER-MID 60S.

CONCERNS SHIFTS TO SEA FOG AND FOG DEVELOPING FROM STATUS BUILD-
DOWN. THE PATTERN APPEARS TO FAVOR A WIDESPREAD STRATUS BUILD-DOWN
EVENT AS RAIN DIMINISHES AND WEAK LOW-LEVEL JETTING ENSUES.
ALREADY SEEING A NUMBER OF INLAND STATIONS REPORTING CEILINGS LESS
THAN 1000 FT WHICH INDICATES BUILD-DOWN IS ALREADY IN PROGRESS.
THE RAIN MOVING ACROSS SOUTHEAST GEORGIA COULD DELAY ANY
ADDITIONAL CLOUD LOWERING THERE FOR A FEW MORE HOURS...BUT SHOULD
RESTART BY LATE EVENING. THIS WILL EVENTUALLY TRANSLATE TO AREAS
OF FOG AND POSSIBLY SOME LIGHT DRIZZLE...BUT VSBYS MAY NOT GO MUCH
BELOW 1-2 MILES GIVEN THE DEGREE OF LOW-LEVEL JETTING IN PLACE.
CLOSER TO THE COAST...SEA FOG WAS ALREADY PREVALENT OVER THE
COASTAL WATERS AND AS WINDS TURN BACK TO THE SOUTH OVER THE NEXT
FEW HOURS...THE COMBINATION OF SEA FOG MOVING INLAND AND STRATUS
BUILD-DOWN COULD BE JUST ENOUGH TO TIP VSBYS BELOW 1 MILE. A DENSE
FOG ADVISORY MAY VERY WELL BE NEEDED IN SOME AREAS BEFORE SUNRISE
WEDNESDAY AND TRENDS ARE BEING MONITORED CLOSELY.

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY THROUGH WEDNESDAY NIGHT...THE AREA REMAINS FIRMLY
ENTRENCHED WITHIN A DEEP AND RICH SOUTH/SE FLOW THROUGHOUT THE
ENTIRE VERTICAL COLUMN...IN THE ZONE BETWEEN STRONG SUB-TROPICAL
RIDGING TO THE EAST/SE BOTH SURFACE AND ALOFT...AND A DEEP CYCLONE
AND FRONTAL SYSTEM OVER THE CENTRAL/NORTHERN PLAINS THAT LIFTS
INTO SOUTHERN CANADA. THE TAP OF COPIOUS AMOUNTS OF MOISTURE WILL
CONTINUE TO FEED INTO THE REGION FROM NOT ONLY THE GULF OF
MEXICO...BUT ALSO THE PACIFIC. ASSOCIATED PWATS OF 1.9-2.0 INCHES
IS CLOSE TO THE HIGHEST ON RECORD FOR THESE PARTS IN DECEMBER.
ALTHOUGH THE BEST FORCING AND DYNAMICS REMAIN OFF TO THE
WEST/NW...THE CLOSE PROXIMITY TO MID LEVEL IMPULSES AND UPPER
DIVERGENCE WILL COMBINE WITH AN ABUNDANTLY MOIST ATMOSPHERE TO
PRODUCE ANOTHER FAIRLY WET AND CLOUDY DAY. THE FLOW LOOKS A LITTLE
TOO FAST WITH A35-40 KT LOW LEVEL JET TRAVERSING THE AREA FOR ANY
SIGNIFICANT FLOODING CONCERNS. ALTHOUGH MINOR FLOODING MAY OCCUR
WITH SOME HEAVY DOWNPOURS AND FURTHER COMPLICATIONS AROUND THE
TIMES OF HIGH TIDE IN THE PRE-DAWN AND AGAIN IN THE EARLY EVENING.

MODEST SHEAR VALUES AND SOME CAPE SUPPORTS THE POTENTIAL FOR A
FEW T-STORMS. BUT POOR LAPSE RATES AND THE OVERCAST SKIES SUGGEST
THAT ANY SEVERE RISK IS CLOSE TO ZERO.

LAND-BASED FOG IN THE MORNING WILL LIFT BY 10 AM BUT LINGER NEAR
OR JUST OFF THE COAST THE REST OF THE DAY...BEFORE COMING BACK
AGAIN WEDNESDAY NIGHT. DENSE FOG ADVISORIES MIGHT BE
REQUIRED...ALTHOUGH THE WIND FIELDS WEDNESDAY NIGHT MIGHT BE A
LITTLE TOO STRONG.

TEMPS WILL REMAIN FAR ABOVE NORMAL...BELOW ANY RECORD HIGHS
WEDNESDAY BUT POSSIBLY NEAR RECORD HIGH MINIMUMS WEDNESDAY NIGHT.

THURSDAY THROUGH FRIDAY...DEEP RIDGING BOTH SURFACE AND ALOFT
WILL EXPAND WEST FROM THE ATLANTIC AS 500 MB HEIGHTS CLIMB TO NEAR
RECORD LEVELS FOR DECEMBER. WE MIGHT BE ABOVE 5900 METERS BOTH
DAYS AS 850 MB TEMPS REMAIN NEAR 2 OR 3 STANDARD DEVIATIONS ABOVE
NORMAL. COMBINED WITH LOW LEVEL THICKNESS APPROACHING 1400 METERS
WILL GENERATE YET ADDITIONAL WARMTH. AND AS INCREDIBLE AS IT
SOUNDS PARTS OF THE FORECAST DISTRICT CHRISTMAS EVE AND CHRISTMAS
DAY WILL REACH NEAR OR OVER 80F. THIS IS SOME 20F ABOVE WHAT IS
CONSIDERABLE NORMAL FOR THIS TIME OF YEAR. MORE SUBSIDENCE AND
LESS AVAILABLE MOISTURE POINTS TOWARDS LESS RISK FOR SHOWERS AND
T-STORMS. BUT THE POTENTIAL FOR FOG IS HIGH GIVEN LESS GEOSTROPHIC
WINDS...ELEVATED DEW POINTS...STRATUS BUILD-DOWN AND THE RISK FOR
SEA FOG. DENSE ADVISORIES SEEM A GOOD BET THURSDAY NIGHT INTO
FRIDAY MORNING.

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A DEEP LAYERED RIDGE WILL PREVAIL NEXT WEEKEND INTO EARLY NEXT
WEEK. WARM AND MOIST AIR WILL PERSIST WITH HIGH TEMPS APPROACHING
DAILY RECORDS AND DEWPOINTS WELL INTO THE 60S. A WEAK COASTAL
TROUGH MAY MOVE INLAND AT SOME POINT OVER THE WEEKEND SO WE HELD
ONTO SLIGHT CHANCE POPS AT TIMES. BUT THERE DO NOT LOOK TO BE ANY
SIGNIFICANT WEATHER SYSTEMS UNTIL EARLY TO MID NEXT WEEK WHEN A
FRONT APPROACHES.

.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
KCHS...IFR CIGS ARE ALREADY IN PLACE AT KCHS AND ARE EXPECTED TO
DROP BELOW ALTERNATE MINIMUMS 02-03Z. THE VSBY FORECAST IS NOT AS
CLEAR CUT...BUT VSBYS AS LOW AS 2-3SM ARE POSSIBLE...MAINLY AFTER
09Z. IF SEA FOG MOVES INLAND FROM THE ATLANTIC LIKE SOME GUIDANCE
SUGGESTS...THEN BOTH CIGS AND/OR VSBYS COULD DROP BELOW AIRFIELD
MINIMUMS. THIS IS NOT EXPECTED ATTM. CONDITIONS WILL IMPROVE BY
14Z...BUT MVFR CIGS WILL PREVAIL THROUGH THE PERIOD.

KSAV...LIGHT RAIN MOVING ACROSS THE TERMINAL WILL DELAY THE ONSET
OF IFR CIGS UNTIL AFTER 03Z...AFTER WHICH STRATUS BUILD-DOWN WILL
ENSUE. EXPECT CIGS TO DROP BELOW AIRFIELD MINIMUMS BY 08-09Z...BUT
THE TIMING OF THIS IS A LITTLE UNCERTAIN. IT COULD EASILY GET
THERE BEFORE THEN...BUT CONFIDENCE IS NOT HIGH ENOUGH ATTM TO MOVE
THIS FORWARD IN TIME. IT APPEARS BOTH VSBYS AND CIGS WILL REMAIN
ABOVE AIRFIELD MINIMUMS...BUT IT COULD BE CLOSE IF SOME SEA FOG
ADVECTS IN FROM OFF THE ATLANTIC. CONDITIONS WILL IMPROVE BY
14Z...BUT MVFR CIGS WILL PREVAIL THROUGH THE PERIOD.

EXTENDED AVIATION OUTLOOK...PROLONGED PERIODS OF MVFR OR LOWER
CONDITIONS WILL IMPACT THE TERMINALS MUCH OF THE TIME WEDNESDAY
AFTERNOON INTO SUNDAY...WITH THE WORST WEATHER OF IFR/LIFR TO
OCCUR AT NIGHT AND INTO THE MORNING HOURS IN DENSE FOG/STRATUS.

.MARINE...
TONIGHT..VSBYS HAVE IMPROVED A BIT ACROSS THE WATERS WHERE WINDS
HAVE BACKED A BIT MORE TO THE SOUTHEAST. THIS HAS REDUCED PARCEL
RESIDENCE TIMES OVER THE CHILLY SHELF WATERS. EXPECT WINDS TO BACK
BACK TO THE SOUTH OVER THE NEXT FEW HOURS WHICH SHOULD SUPPORT A
REDEVELOPMENT OF DENSE SEA FOG. A MARINE DENSE FOG ADVISORY IS IN
EFFECT FOR ALL NEARSHORE LEGS THROUGH MIDNIGHT...BUT THIS MAY NEED
TO BE EXTENDED. SOME FOG HAS REACHED THE CHARLESTON HARBOR...AND
THE ADVISORY MAY VERY WELL NEED TO BE EXPANDED TO INCLUDE IT LATER
THIS EVENING.

OTHERWISE...WINDS WILL VEER SOUTH OVERNIGHT WITH WINDS 10 KT OR
SO NEARSHORE WATERS AND AS HIGH AS 15 KT OFFSHORE WATERS. SEAS
WILL AVERAGE 3-5 FT NEARSHORE AND 4-6 FT OFFSHORE.

WEDNESDAY THROUGH WEDNESDAY NIGHT...THE COASTAL WATERS WILL LIE
WITHIN THE WESTERN PERIPHERY OF AN EXPANDING REGION OF ATLANTIC
HIGH PRESSURE...AS AN INTENSE STORM SYSTEM PULLS RAPIDLY NORTH/NE
THROUGH THE GREAT PLAINS AND INTO SOUTHERN CANADA. WHILE MIXING IS
STRONGLY CURTAILED WITHIN THE WARM ADVECTION PATTERN...THE
GRADIENT FLOW IS STILL HIGH ENOUGH TO SUPPORT A LOW-END SMALL
CRAFT ADVISORY FOR AT LEAST AMZ350 AND AMZ374. A FEW 6-FOOTERS
COULD SLIDE INTO AMZ352...BUT THE COVERAGE IS FAR TOO LIMITED TO
HOIST AND ADVISORY AT THIS TIME. ALSO...WINDS MIGHT REACH CLOSE TO
25 KT FOR A FEW HOURS WEDNESDAY AFTERNOON INTO THE EVENING...BUT
PROBABILITIES ARE LOW ENOUGH WHERE WE DON/T NEED AN ADVISORY FOR
THEM EITHER.

THURSDAY THROUGH SUNDAY...A STRONG AND BROAD SUB-TROPICAL
ATLANTIC HIGH WILL BUILD WESTWARD ACROSS THE MARITIME COMMUNITY
RESULTING IN GENERAL SOUTH/SE WIND AT OR BELOW 15 KT. FOR THE MOST
PART SEAS WILL BE NO MORE THAN 3-5 FT...EXCEPT LINGERING 6-FOOTERS
ON THE OUTER GA WATERS THROUGH MUCH OF THURSDAY WHERE AN SCA
REMAINS IN EFFECT.

SEA FOG...CONDITIONS ARE FAVORABLE FOR A CONTINUATION OF SEA FOG
INTO THE WEEKEND...DUE TO THE UNSEASONABLY WARM AND VERY HUMID AIR
OVER-RIDING THE COOLER SHELF WATERS. WINDS MIGHT BE A LITTLE TOO
STRONG WEDNESDAY INTO WEDNESDAY NIGHT TO KEEP THE DENSE FOG TO A
MINIMUM. BUT LIGHTER WIND FIELDS THURSDAY INTO THE WEEKEND COULD
RESULT IN A GREATER COVERAGE OF DENSE FOG. EITHER WAY...MARINE
DENSE FOG ADVISORIES APPEAR HIGHLY LIKELY...WITH THE POSSIBILITY
THAT THE FOG WILL IMPACT CHARLESTON HARBOR AT TIMES EACH MORNING
AND AGAIN DURING MUCH OF THE NIGHT TIME HOURS THROUGH THE PERIOD.

THUNDERSTORMS...MARINERS ARE ADVISED THAT ISOLATED TO SCATTERED
THUNDERSTORMS WILL OCCASIONALLY IMPACT THE COASTAL WATERS...AND
SIMILAR TO TUESDAY THERE WILL BE THE RISK FOR WIND GUSTS
APPROACHING 34 KT AT TIMES.

.CLIMATE...
RECORD HIGHS FOR DECEMBER 23RD...
KCHS...82/2013.
KCXM...76/1990.
KSAV...81/1956.

RECORD HIGHS FOR DECEMBER 24TH...
KCHS...76/1988.
KCXM...76/1921.
KSAV...80/1931.

RECORD HIGHS FOR DECEMBER 25TH...
KCHS...80/2008.
KCXM...76/2008 (MULTIPLE YEARS).
KSAV...80/2008 (MULTIPLE YEARS).

RECORD HIGHS FOR DECEMBER 26TH...
KCHS...78/1942.
KCXM...74/1982 (MULTIPLE YEARS).
KSAV...79/1987.

RECORD HIGH MINIMUMS FOR DECEMBER 23RD...
KCHS...66/1990.
KCXM...68/1990.
KSAV...65/1990.

RECORD HIGH MINIMUMS FOR DECEMBER 24TH...
KCHS...60/1964.
KCXM...60/1964.
KSAV...62/1879.

RECORD HIGH MINIMUMS FOR DECEMBER 25TH...
KCHS...62/2008 (MULTIPLE YEARS).
KCXM...63/1964 (MULTIPLE YEARS).
KSAV...65/1932.

RECORD HIGH MINIMUMS FOR DECEMBER 26TH...
KCHS...67/1964.
KCXM...66/1964.
KSAV...63/1987 (MULTIPLE YEARS).

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350-352-
354.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR AMZ374.
SMALL CRAFT ADVISORY FROM 7 AM WEDNESDAY TO 11 AM EST THURSDAY
FOR AMZ350.

AREA FORECAST DISCUSSION

NWS INDIANAPOLIS IN

1002 PM EST TUE DEC 22 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW

.SYNOPSIS...
ISSUED AT 256 PM EST TUE DEC 22 2015

PATTERN TO REMAIN MILD THROUGH AND BEYOND THE SEVEN DAY FORECAST.
A COUPLE OF SIGNIFICANT STORMS SYSTEMS...WEDNESDAY WITH POTENTIAL
DAMAGING WIND...AND THIS WEEKEND...WITH HEAVY RAIN THAT MAY LEAD
TO FLOODING...WILL FINISH OUT THE ACTIVE WEATHER PATTERN LATE THIS
YEAR.

.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1002 PM EST TUE DEC 22 2015

AFTER SOME SUNSHINE FOR MOST LATE THIS AFTERNOON...LOWER STRATUS
HAS ADVECTED BACK ACROSS MOST OF THE FORECAST AREA AS OF 03Z WITH
MOISTURE STREAMING NORTH AND INTERACTING WITH THE SHALLOW
INVERSION STILL PRESENT. FAR NORTHERN COUNTIES HAVE MANAGED TO
DROP QUICKLY INTO THE MID AND UPPER 30S THIS EVENING WHERE SKIES
HAVE REMAINED CLEAR THE LONGEST...WITH TEMPS RANGING FROM THE MID
40S TO LOWER 50S OVER MOST OF THE REST OF THE FORECAST AREA.

PIECES ALREADY STARTING TO ALIGN THAT WILL BRING THE WARM
TEMPERATURES WEDNESDAY ALONG WITH THE UNUSUAL SEVERE WEATHER RISK
FOR THE AFTERNOON AND EVENING WEDNESDAY. POLEWARD MOISTURE RETURN
OVER THE LAST 6 HOURS FROM THE GULF COAST HAS BEEN IMPRESSIVE TO
OUR SOUTH TO PUT IT MILDLY. 60+ DEGREE DEWPOINTS NOW WELL INTO THE
TENNESSEE VALLEY AND WILL LIKELY ADVANCE INTO KENTUCKY AFTER
MIDNIGHT. ALREADY SEEING PATCHY FOG IN THE LOWER WABASH VALLEY AS
THE DEEPER MOISTURE ARRIVES AND EXPECT THAT TO CONTINUE OVERNIGHT
IN SOME AREAS.

LOWS HAVE ALREADY BEEN MET...WITH TEMPERATURES STEADILY
CLIMBING FOR THE REST OF THE NIGHT AS WARM MOIST AIR SPREADS
NORTH. RAP AND NAM BOTH HINTING AT SURFACE TEMPS NEAR 60 OVER
SOUTHERN FORECAST AREA BY DAYBREAK AND CONSIDERING CURRENT TEMPS
OVER THE TENNESSEE AND LOWER MISSISSIPPI VALLEYS...THAT DOES NOT
SEEM FAR OFF.

CONVECTION ACROSS THE LOWER MISSISSIPPI VALLEY WILL RACE NORTHEAST
OVERNIGHT AND WHILE BULK OF THE ACTIVITY SHOULD REMAIN TO THE
SOUTHEAST OF THE FORECAST AREA...HI-RES GUIDANCE CONTINUING TO
CAPTURE SCATTERED SHOWERS INCREASING IN COVERAGE AFTER 06Z FROM
THE SOUTH AS WARM ADVECTION INTENSIFIES OVER THE OHIO VALLEY.
HAVE ADJUSTED POPS SLIGHTLY...BUT INTRODUCING LOW CHANCES FOR
ENTIRE FORECAST AREA FOR THE PREDAWN HOURS. MEANWHILE BACK TO THE
SOUTHWEST...EXPECT RAPID CONVECTIVE DEVELOPMENT OVER THE OZARKS AS
THE INTENSE LOW PRESSURE SWINGS OUT THROUGH THE CENTRAL PLAINS AND
BEGINS TO INTERACT WITH THE GULF MOISTURE FETCH. THIS WILL
CONTINUE TO INCREASE IN COVERAGE AND EXPAND INTO THE REGION BY MID
TO LATE MORNING WEDNESDAY.

ZONE AND GRID UPDATES OUT.

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

ISSUED AT 256 PM EST TUE DEC 22 2015

FORECAST ISSUE IS SEVERE WEATHER THREAT WEDNESDAY. THOUGH MODEL
DYNAMICS IN FAIRLY GOOD AGREEMENT...AMOUNT OF DESTABILIZATION
PRIOR TO MAIN SHOWER/SQUALL BAND ARRIVAL IN THE AFTERNOON MAY
DETERMINE HOW GUSTY CONVECTION MAY GET. MODEL SOUNDINGS SUGGEST
MIXING OF 40MPH GUSTS TO THE GROUND PRIOR TO ANY STORM LINE MAY
OCCUR AS WELL SO HAVE INCLUDED GUSTY WORDING IN THE FORECAST.

NAM SOMEWHAT DIFFERENT THAN OTHER MODELS IN HAVING QUITE DISTINCT
AND SIMILARLY POTENT ROUNDS OF STORMS...AFTERNOON AND THEN EVENING
WITH COLD FRONT TIED WITH TWO INSTABILITY AXES. WILL LEAN TOWARD
A BLEND OF MODELS AND FORECAST WORDING MAY NOT REFLECT THE
SEPARATION BUT TWO HEAVIER ROUNDS OF RAIN APPEAR POSSIBLE.

STRENGTH OF WARM ADVECTION SHOULD LEAD TO ADVERTISED RECORD OR
NEAR RECORD HIGHS IN THE UPPER 60S WEDNESDAY.

WEDNESDAY NIGHT...NAM IS SLOWEST WITH COLD FRONT WHILE GFS IS
QUITE FAST SO WILL AVERAGE BETWEEN THESE. END RESULT IS AT LEAST
ONE MORE DECENT SHOT OF RAIN WITH COLD FRONT PASSAGE DURING THE
EVENING WITH LINGERING SHOWERS ENDING BEFORE DAYBREAK.

THURSDAY AND PART OF FRIDAY...A DRY TRANQUIL PERIOD IS IN STORE
AS HIGH PRESSURE BUILDS IN BEHIND THE INTENSIFYING LOW THAT LIFTS
NE INTO THE HUDSON BAY AREA. HAVE KEPT TEMPERATURES NEAR GUIDANCE
AND STILL WELL ABOVE NORMAL WITH HIGHS MAINLY IN THE 50S AND LOWS
ABOVE FREEZING.

AS THE NEXT STRONG SHORTWAVE DUMPS INTO THE WESTERN TROUGH...THE
SURFACE BOUNDARY THAT SLIPPED INTO KENTUCKY THURSDAY WILL LIFT
BACK NORTH TO BEGIN THE NEXT RAINY PERIOD.

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

ISSUED AT 232 PM EST TUE DEC 22 2015

ECMWF CONTINUES TO SUGGEST STRONG SOUTHWEST FLOW ALOFT OVER THE
EASTERN HALF OF THE UNITED STATES DURING THIS PERIOD...WITH MILD AND
MOIST GULF AIR FLOWING NORTH INTO THE OHIO VALLEY. A DEEP LOW
DEVELOPING OVER THE AMERICAN SOUTHWEST WILL GRADUALLY PUSH EAST
INTO TEXAS DURING THIS PERIOD...OCCASIONAL EJECTING WEAK SHORT
WAVES INTO THE SW FLOW ALOFT TOWARD THE OHIO VALLEY THROUGH
TUESDAY. MEANWHILE IN THE LOWER LEVELS A FRONTAL BOUNDARY IS
EXPECTED TO LINGER ACROSS CENTRAL INDIANA AND THE OHIO VALLEY
THROUGH MUCH OF THE PERIOD...PROVIDING A FOCUS FOR LOWER LEVEL
CONVERGENCE AND PRECIPITATION. THUS WILL AGAIN CONTINUE THE
ONGOING FORECAST THROUGH THE PERIOD WITH PLENTY OF POPS AND ABOVE
NORMAL TEMPERATURES.

.AVIATION /DISCUSSION FOR THE 230300Z KIND TAF UPDATE/...
ISSUED AT 930 PM EST TUE DEC 22 2015

IFR CEILINGS AROUND 008 AGL HAVE ALREADY MOVED INTO THE KIND TERMINAL.
THIS HAS BEEN ADDRESSED WITH AN EARLIER UPDATE.

SHORT TERM MODEL GUIDANCE SUGGESTS THERE MAY A WINDOW BETWEEN
230400Z-230800Z WHERE THE LOW CEILINGS MAY TEMPORARILY SCATTER OUT AT
THE KIND TERMINAL AS SOME DRIER AIR WORKS IN FROM THE SOUTHEAST.
CEILINGS HAVE IMPROVED OVER SOUTHEAST INDIANA RECENTLY...SO THIS
SCENARIO IS POSSIBLE. WILL CONTINUE TO MONITOR TRENDS.

PREVIOUS DISCUSSION FOLLOWS.

AREAS OF CEILINGS 010-015 CONTINUE ACROSS CENTRAL INDIANA...WITH
SOME BREAKS IN THE CLOUD COVER OVER THE KIND/KBMG TERMINALS. SUSPECT
THIS WILL BE SHORT LIVED AS SATELLITE INDICATES CEILINGS EXPANDING
RATHER RAPIDLY NORTHWARD OVER SOUTHERN INDIANA. NOCTURNAL COOLING OF
THE BOUNDARY LAYER AND MOIST ADVECTION SHOULD ALLOW FOR CEILINGS TO
FALL INTO THE IFR CATEGORY AFTER ABOUT 230500Z. SOME VISIBILITY
RESTRICTIONS IN FOG ALSO PROBABLE IN THE HOURS PRIOR TO DAYBREAK
WEDNESDAY...BUT THE CEILINGS SHOULD BE THE BIGGER ISSUE.

SURFACE WINDS 130-160 DEGREES AT 6-9 KTS TONIGHT.

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

SYNOPSIS...TUCEK
NEAR TERM...RYAN
SHORT TERM...TUCEK
LONG TERM....PUMA
AVIATION...JAS

AREA FORECAST DISCUSSION

NWS NORTHERN INDIANA

337 PM EST MON DEC 21 2015

.SYNOPSIS...
ISSUED AT 331 PM EST MON DEC 21 2015

A CHANCE OF SHOWERS ALONG WITH AREAS OF DRIZZLE WILL PERSIST INTO
TONIGHT WITH OVERNIGHT LOWS FALLING INTO THE LOWER 40S.
TEMPERATURES WILL NOT WARM MUCH ON TUESDAY AS CLOUD COVER HOLDS
STRONG WITH HIGHS REACHING THE MIDDLE 40S TO AROUND 50. CHANCES
FOR SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL ARRIVE WEDNESDAY
INTO WEDNESDAY EVENING ALONG WITH RECORD BREAKING HIGHS FROM THE
UPPER 50S TO MIDDLE 60S.

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 331 PM EST MON DEC 21 2015

KIWX RADAR SHOWING DIMINISHING TRENDS IN BOTH INTENSITY AND COVERAGE
OF SHRA THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC ANALYSIS
DEPICTING LEAD SHORT WAVE MOVING NE ACROSS SOUTHERN GREAT LAKES
REGION WITH TRAILING UPPER TROF MOVING INTO THE PLAINS STATES.
CONTINUED SW FLOW ALOFT WILL BRING SECOND DISTURBANCE NE INTO
SOUTHERN GREAT LAKES BY TUESDAY MORNING WHICH WILL KEEP SMALL
CHANCES FOR LIGHT PRECIP OVERNIGHT. FORECAST SOUNDINGS INDICATING
2KFT SATURATED LAYER BELOW LOW LEVEL INVERSION WHICH WILL BRING
POTENTIAL FOR PATCHY FOG/DRIZZLE OVERNIGHT AS WELL. STRONG UPPER JET
DYNAMICS COMING ONSHORE INTO THE PACIFIC NW WILL AMPLIFY THE PATTERN
AND INDUCE 80-100M HEIGHT RISES OVER OUR AREA TUESDAY WHICH WILL
PROVIDE A BRIEF BREAK IN PRECIP. PATTERN REMAINS UNSEASONABLY MILD
THIS PERIOD WITH LOWS IN THE L40S AND HIGHS 45-50.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 331 PM EST MON DEC 21 2015

INCREASINGLY DYNAMIC PATTERN WILL BE SETTING UP FOR THE REGION
THROUGH THE REMAINDER OF THE LONG TERM AND BEYOND WITH INITIAL
FOCUS ON STRONG MID WEEK SYSTEM.

FIRST UPPER LEVEL WAVE OF INTEREST HAS NOW MADE IT ONSHORE IN THE NW
STATES WITH A PIECE OF THIS STARTING TO DROP SOUTH INTO THE PLAINS
BY TUESDAY. AS IT DOES...THE UPPER FLOW WILL BUCKLE SENDING YET
ANOTHER SURGE OF WARM AND INCREASINGLY HUMID (UNSTABLE?) AIR INTO
THE REGION FOR WEDNESDAY AND WEDNESDAY NIGHT. AS MENTIONED IN
OVERNIGHT DISCUSSION...FOCUS ON NOT ONLY HEAVY RAIN BUT ALSO SEVERE
POTENTIAL LOOMS ESPECIALLY WEDS AFTERNOON AND EVENING. FIRST FOR
RAINFALL...PWATS OF AROUND 1.25" OR GREATER WILL FUNNEL IN AHEAD OF
THE FRONT ON 50+ KT LOW LEVEL JET BY WEDNESDAY AFTERNOON. JUST
ENOUGH INSTABILITY GETS INTO THE AREA LATE AFTERNOON/EARLY EVENING
WITH SFC BASED CAPES BETWEEN 250 AND 500 J/KG WITH 0-6 KM BULK SHEAR
IN EXCESS OF 70 KNOTS WEDNESDAY NIGHT. THIS WOULD SET THE STAGE FOR
A POTENTIAL OF LOW TOPPED SUPERCELLS IN A LOW CAPE/HIGH SHEAR
ENVIRONMENT. NOW...THE DRAWBACKS...PREFRONTAL TROUGH MAY HAVE
ALREADY SHIFTED ACROSS THE AREA PRIOR TO THE ARRIVAL OF THE PHASING
OF THESE FEATURES WITH NAM SHOWING STG-SVR STORMS CLOSER TO THE OHIO
RIVER AND POINTS SOUTH. FOR NOW HAVE EXPANDED THUNDER MENTION INTO
WEDS EVENING AND WENT CHC VS SLGT CHC. WILL TOUCH UP HWO TO EXTEND
WIND THREAT INTO WEDS EVE BUT HOLD OFF ON ANY MENTION OF SEVERE FOR
THE MOMENT. SPC DAY3 OUTLOOK DOES HAVE MUCH OF OUR AREA IN MARGINAL
RISK WITH GREATER RISK BY FAR FURTHER SOUTH. WITH REGARDS TO
TEMPERATURES UNTIL THE DEEP LOW PASSES...OVERNIGHT LOWS WILL OCCUR
TUESDAY EVENING WITH CLIMBING TEMPS THROUGH THE NIGHT INTO WEDNESDAY
AS HIGHS TOP OUT AT WHAT SHOULD BE RECORD VALUES.

A BRIEF DRY PERIOD WILL BE IN STORE FOR THURS AND THURS NIGHT BEFORE
2 WAVES MOVE TOWARDS THE AREA. THE FIRST WILL BE ON THE WEAKER SIDE
(AT LEAST IN COMPARISON TO NEXT WEEKS SYSTEM) BUT WILL HELP
REINFORCE THE BOUNDARY TO OUR SOUTH AND BEGIN TO PUSH IT BACK NORTH
WITH RAIN CHANCES INCREASE ESPECIALLY SAT AND SAT NGT WHERE HIGH CHC
TO LIKELY POPS ARE WARRANTED GIVEN THE ACTIVE PATTERN. TOWARDS THE
END AND ESPECIALLY OUTSIDE THE FORECAST PERIOD A POWERFUL STORM
LOOKS TO TAKE SHAPE ACROSS THE SW STATES AND EJECT INTO THE EASTERN
PLAINS/WESTERN GREAT LAKES. THIS WILL LIKELY BRING MORE RAIN TO THE
AREA ALONG WITH A THREAT OF STORMS. ALSO GIVEN THE SERIES OF
SYSTEMS...HYDRO CONCERNS COULD INCREASE BETWEEN CHRISTMAS AND NEW
YEARS.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED
AT 1230 PM EST MON DEC 21 2015

RADAR TRENDS SHOWING PRECIP MOVING OUT OF THE AREA GOING INTO THE
AFTERNOON HOURS AS LEAD SHORT WAVE MOVES NE THROUGH THE GREAT LAKES
REGION. BREEZY S/SW WINDS WILL CONTINUE TO BEGIN THE TAF PERIOD
ALTHOUGH PROXIMITY OF SURFACE LOW MAY LIMIT GUSTS AT KSBN. UPSTREAM
OBS INDICATING IFR CIGS WILL CONTINUE THIS AFTERNOON WITH POTENTIAL
FOR SOME IMPROVEMENT BY EARLY EVENING BEFORE APPROACH OF SECOND
UPPER LEVEL DISTURBANCE TONIGHT BRINGS A CHANCE FOR A FEW SHOWERS
ALONG WITH IFR CIGS. HIRES MODELS AND FORECAST SOUNDINGS INDICATING
LOW LEVEL INVERSION OVERNIGHT AND PERSISTING INTO TUESDAY MORNING
WILL KEEP LOWEST 2KFT SATURATED AND POTENTIAL FOR CIGS TO DROP DOWN
TO LIFR. SURFACE LOW EXPECTED TO LIFT NE TUESDAY AND ALLOW WEAK HIGH
PRESSURE TO BUILD INTO THE AREA WHICH WILL BRING GRADUALLY IMPROVING
CONDITIONS TOWARD THE END OF THE TAF PERIOD.

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.

SYNOPSIS...FISHER
SHORT TERM...JAL
LONG TERM...FISHER
AVIATION...LOGSDON

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AREA FORECAST DISCUSSION

NWS NORTHERN INDIANA

1259 AM EST MON DEC 21 2015

.SYNOPSIS...
ISSUED AT 1258 AM EST MON DEC 21 2015

THIS WEEK WILL FEATURE WELL ABOVE NORMAL TEMPERATURES AND SEVERAL
OPPORTUNITIES FOR RAIN AS UPPER LEVEL SYSTEMS LIFT NORTHEAST
THROUGH THE REGION. THE FIRST SYSTEM MOVES THROUGH TODAY WITH
WIDESPREAD RAIN...ESPECIALLY DURING THE MORNING AND EARLY
AFTERNOON HOURS. AFTER A BRIEF DRY PERIOD ON TUESDAY...RAIN
SHOWERS LIKELY RETURN WEDNESDAY INTO WEDNESDAY NIGHT. HIGHS TODAY
AND TUESDAY WILL GENERALLY RANGE BETWEEN THE UPPER 40S AND LOW
50S...WITH RECORD WARMTH INTO THE LOW TO MID 60S POSSIBLE
WEDNESDAY. COOLER AND DRIER WEATHER IS THEN EXPECTED TO RETURN
THURSDAY INTO FRIDAY...WITH RENEWED RAIN CHANCES BY NEXT WEEKEND.

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 336 PM EST SUN DEC 20 2015

WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS DEPICTING UPPER TROF
OVER THE FOUR CORNERS WITH POTENT 120KT UPPER JET MOVING UP THE
EAST SIDE OF THE TROF AXIS. THIS ENERGY WILL EJECT EASTWARD AND
HELP ORGANIZE DEVELOPING SURFACE LOW IN THE PLAINS. DESPITE
PROGRESSIVE NATURE OF THIS SYSTEM...IMPRESSIVE DYNAMICS WILL AID
IN DECENT MOISTURE TRANSPORT INTO THE REGION OVERNIGHT AND SUPPORT
WIDESPREAD LIGHT TO MODERATE RAIN. GOOD ISENTROPIC ASCENT AHEAD OF
THIS SYSTEM WILL RAPIDLY SATURATE THE LOW LEVELS AFTER 06Z IN OUR
WESTERN CWA WITH ARRIVAL OF 60KT LLJ EARLY MONDAY MORNING. WILL
TREND ARRIVAL OF PRECIP IN A NW/SE ORIENTATION WITH NW CWA
BECOMING LIKELY SHORTLY AROUND 06Z AND SE BY 09Z MONDAY. MODELS IN
DECENT AGREEMENT WITH BRINGING WEAK DRY SLOT INTO THE AREA MONDAY
AFTERNOON WHICH WILL DIMINISH...BUT NOT ELIMINATE...POPS DOWN TO
CHANCE/SLIGHT CHANCE. WARM AIR ADVECTION PATTERN ON STRONG
SOUTHERLY FLOW WILL LIMIT DIURNAL TEMP CHANGES DURING THE PERIOD
WITH LOWS TONIGHT NEAR 40F AND HIGHS NEAR 50F OVER MOST OF THE CWA
MONDAY.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 336 PM EST SUN DEC 20 2015

RETURN TO ABOVE TO WELL ABOVE NORMAL TEMPERATURES FOR MOST IF NOT
ALL THE FORECAST PERIOD...WITH A FEW CHANCES FOR
RAINFALL...ESPECIALLY MIDWEEK.

LOW PRESSURE WILL BE QUICKLY EXITING TO THE NORTHEAST OF THE AREA
WITH A TRAILING DISTURBANCE MOVING THROUGH THE AREA MONDAY NIGHT.
SOME WEAK LIFT IS DEPICTED IN ALL MODELS IN THE LOWEST LEVELS WITH
NAM THE MOST PRONOUNCED. NOT SURE ABOUT HOW MUCH OF THE PRECIP
WILL BE MEASURABLE RAIN VS DRIZZLE GIVEN SHALLOW NATURE OF LIFT.
WILL KEEP WITH SLGT CHC TO CHC POPS AND ADD MENTION OF PATCHY
DRIZZLE THROUGH THE NIGHT. LITTLE SIGNIFICANT CHANGE IN SURFACE
TEMPERATURES MON NGT INTO TUESDAY WITH ONLY A GLANCING BLOW OF
SLIGHTLY COLDER BUT STILL ABOVE NORMAL) AIR.

FOCUS THEN SHIFTS TO DEEP TROUGH DIGGING INTO THE CENTRAL PLAINS
WHICH WILL EJECT TOWARDS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT
ADVECTING WARMER AND MORE HUMID AIR (PWATS 0.75 TO 1 INCH) INTO
THE REGION. WITH CURRENTLY FORECASTED HIGHS OF 60 OR
HIGHER...RECORD HIGH TEMPERATURES WILL BE BROKEN FOR BOTH SOUTH
BEND AND FT WAYNE (59 IN 1933 AND 59 IN 1941 RESPECTIVELY).
SHOWERS CHANCES WILL INCREASE FROM WEST TO EAST WEDNESDAY
AFTERNOON INTO WEDNESDAY NIGHT WITH ALL LOCATIONS TO SEE AT LEAST
SOME MEASURABLE RAINFALL. HEAVIEST AXIS OF RAINFALL LOOKS TO
REMAIN INTO ILLINOIS. NEIGHBORS TO THE WEST AND SOUTH HAVE ADDED
MENTION OF THUNDER AND WHILE NAM/GFS DO ATTEMPT BRING A NARROW
RIBBON OF NEAR ZERO SHOWALTERS IN BETWEEN 00Z AND 6Z NOT CONVINCED
COVERAGE (IF ANY) WILL BE ENOUGH TO WARRANT A MENTION.

GIVEN THE WESTERLY TRACK OF THE LOW AND RELOADING OF AN EVEN
STRONGER TROUGH IN THE WEST...NO MAJOR COLD AIR ARRIVES WITH
READINGS DROPPING BACK TO THE 40S AND 50S...STILL WELL ABOVE THE
NORMALS IN THE UPPER 30S AND NOT BODING WELL FOR ANY CHANCES OF A
WHITE CHRISTMAS FOR THE AREA. LARGE MODEL DIFFERENCES EXIST WITH
HANDLING OF CLOSED UPPER LOW AND ITS IMPACTS THIS WEEKEND. HAVE
CONTINUED WITH SLGT CHC TO CHC POPS STARTING FRIDAY NIGHT AND
PERSISTING THROUGH THE WEEKEND. TEMPERATURES MAY RETURN TO NEAR
NORMAL LEVELS AT THE END OF THE PERIOD BUT GIVEN LARGE MODEL
DIFFERENCES NOT SURE IF THIS WILL HOLD TRUE OR NOT.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1258 AM EST MON DEC 21 2015

FLIGHT CONDITIONS WILL STEADILY WORSEN THIS MORNING AS RAIN AND
ASSOCIATED TOP DOWN SATURATION OVERSPREADS IN ADVANCE OF A
MID LEVEL WAVE APPROACHING FROM KANSAS. BULK OF RAIN WILL LIFT
OUT OF THE AREA THIS AFTN AS FOCUSED DEEP LAYER ASCENT/MOISTURE
CONVERGENCE EXITS. HOWEVER...STILL EXPECT IFR TO LOW MVFR
CONDITIONS AND AREAS OF DRIZZLE/LIGHT RAIN INTO THE LATE AFTN/EVE
GIVEN SATURATED LOW LEVELS ALONG A TRAILING SFC TROUGH.
OTHERWISE...GUSTY SSW WINDS/WIND SHEAR CONCERNS EXPECTED THIS
MORNING/EARLY AFTN WITHIN STRONG LOW LEVEL JET CORE.

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LMZ043-
046.

SYNOPSIS...STEINWEDEL
SHORT TERM...JAL
LONG TERM...FISHER
AVIATION...STEINWEDEL

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AREA FORECAST DISCUSSION

NWS DES MOINES IA

544 PM CST TUE DEC 22 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 345 PM CST TUE DEC 22 2015

REMNANTS OF THE MORNING STRATUS SHIELD REMAIN OVER THE NORTHEASTERN
THIRD TO HALF OF THE STATE AND WILL GENERALLY REMAIN SO THIS EVENING
AS THE STRONG INVERSION REMAINS IN PLACE AND WE LOSE WHATS LEFT OF
ANY DAYTIME HEATING AND MIXING. AS A RESULT...CEILINGS AND
VISIBILITIES WILL CONTINUE TO BE LOW IN THOSE AREAS...AROUND 500
FEET AND A COUPLE MILES OR LESS RESPECTIVELY THROUGH THE SHORT TERM.
HAVE NOT CURRENTLY INTRODUCED FOG INTO THE GRIDS...BUT MAY WARRANT
SO DURING THE EVENING...ESPECIALLY FOR AREAS THAT HOLD OFF ON SEEING
PRECIP LONGER AND MOISTURE ADVECTION CONTINUES. AREAS THAT SAW
CLEARING WILL PROGRESSIVELY SEE HIGH BASED CLOUDS MOVE IN BEFORE
CEILINGS FALL AGAIN AS SURFACE LOW AND FORCING PROGRESSES TOWARDS
THE REGION FROM CENTRAL/EASTERN KANSAS.

THE AFOREMENTIONED SURFACE LOW WILL BE THE MAIN CONCERN IN THE SHORT
TERM...BEGINNING TO REALLY INFLUENCE THE AREA AFTER 03Z. THROUGH THE
DAY...NAM AND HRRR HAVE TENDED TO HANDLE THE CLEARING BEST...SO HAVE
TRENDED THAT WAY IN THE GRIDS FOR THIS EVENING. WITHIN THE SHORT
TERM WINDOW...BEST INITIAL FORCING IS THERMODYNAMIC WITH A GOOD PUSH
OF THETA-E ADVECTION ALONG WITH ISENTROPIC LIFT IN THE 290K REGION.
THE DEFORMATION ZONE WILL ALSO BEGIN TO SET UP IN NORTHWEST IOWA
AFTER 06Z...FURTHER BOOSTING LIFT. CURRENTLY...THE COLUMN IS QUITE
DRY FROM ABOUT 850MB TO 500MB...WHICH CALLS INTO SOME QUESTION WHEN
THE COLUMN WILL SATURATE AND PRECIP WILL BEGIN...BUT BEGAN TO UP
POPS IN NORTHWEST IOWA AROUND 5Z AND THROUGH THE SHORT TERM WINDOW
IN CONJUNCTION WITH HRRR/NAM SOLUTIONS.

.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 345 PM CST TUE DEC 22 2015

THE LONG TERM REMAINS ACTIVE WITH SEVERAL SHORTWAVES EJECTING OUT
OF THE BAST OF A LONG WAVE TROUGH OUT WEST. WE BEGIN THE PERIOD
WITH THE SYSTEM AFFECTING THE SHORT TERM LIFTING NORTHEAST. THERE
WILL BE A BRIEF PERIOD OF OF SNOW ON THE BACKSIDE OF THIS SYSTEM
AS IT LIFTS OFF TO THE NORTHEAST. MOST OF THE FORCING EXITS BEFORE
THE CHANGEOVER SO I AM NOT LOOKING AT MUCH ACCUMULATION PLUS WE
WILL BE TOO WARM ALOFT...MAY EVEN SEE A BIT OF FREEZING RAIN WITH
THIS. ALSO...SOME INSTABILITY WORKS INTO EASTERN IOWA AS THIS
SYSTEM LIFTS OUT WHICH MEANS WE COULD SEE SOME ISOLATED THUNDER
WEDNESDAY AFTERNOON. AFTER THIS SYSTEM DEPARTS THERE WILL BE A
BRIEF RESPITE WEDNESDAY NIGHT BEFORE ANOTHER WEAK SHORTWAVE
TRANSLATES ACROSS THE SOUTH AND EAST. TEMPS WILL BE WARM ENOUGH
FOR RAIN WITH THIS SO NOT FORESEEING MUCH IN THE WAY OF TRAVEL
PROBLEMS BUT WITH RIVERS STILL VERY HIGH...ANY HEAVIER RAINFALL
WILL LIKELY RESULT IN FLOODING AGAIN.

THE NEXT MAIN SYSTEM WILL BE A DEEPENING LOW ACROSS THE SOUTHERN
PLAINS LIFTING NORTHEAST. I THINK THE MODELS ARE LIKELY TOO FAST
WITH THIS SYSTEM GIVEN HOW THE LOW IS DEEPENING BUT INITIALLY THIS
WILL BE A RAIN PRODUCER WITH COLD AIR WRAPPING INTO THE LOW
CHANGING PRECIP OVER TO SNOW. THIS ONE MAY BE A POTENTIAL SNOW
PRODUCER FOR US AND NEEDS TO BE WATCHED BUT WILL ALSO BRING
ADDITIONAL FLOODING THREATS.

.AVIATION...23/00Z
ISSUED AT 540 PM CST TUE DEC 22 2015

SOUTHERN SITES...KDSM AND KOTM...WILL SEE VFR CONDITIONS EARLY
BEFORE LOWER CEILINGS AND VISIBILITIES MOVE IN WITH APPROACHING LOW
PRESSURE SYSTEM.CEILINGS AND VISIBILITIES WILL REMAIN PRIMARILY
MVFR ACROSS SITES THROUGH PERIOD WITH CONDITIONS DROPPING TO IFR
OR LIFR AT TIMES WITH RA AT SITES....GENERALLY AFTER 12Z THROUGH
00Z. WINDS WILL BE STRONG AND GUSTY BEYOND 12Z...INCREASING AND
BECOMING NORTHWESTERLY LATE IN THE PERIOD.

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

SHORT TERM...CURTIS
LONG TERM...FAB
AVIATION...AWB

AREA FORECAST DISCUSSION

National Weather Service Topeka KS

1136 PM CST SUN DEC 20 2015

...Update to aviation forecast discussion...

.UPDATE...
Issued at 526 PM CST SUN DEC 20 2015

Have increasing confidence in an area of showers and a few
embedded thunderstorms developing and tracking from central KS
into northeast and east central KS from mid-evening through the
early morning hours. Have increased precip chances in these areas
with confidence very high in the development of this area of
precip, but PoPs muted because of the expected scattered nature
and relatively small area of focused ascent. The driving force for
the majority of this precipitation will be the strong forcing
immediately ahead of the compact upper level short wave forecast
to track from southwest through northeast Kansas in the next 12
hours. Still see signs of elevated instability developing in
advance of this forcing so embedded thunderstorms remain possible
as well.

.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN DEC 20 2015

Winds already picking up in the early morning hours, with winds
aloft forecast to increase and stay up through the day today. This
has kept overnight lows up in the 40s most areas. As the boundary
layer mixes out this morning, RAP and GFS suggest winds at the top
of the mixed layer are close to 50 kts. As a result, expect high
temperatures to make it into the middle/upper50s, and wind speeds to
gust near wind advisory criteria of 40 kts. Will hoist a wind
advisory for those counties along and south of I-70. Still a chance
for some light drizzle and light rain to develop late this morning
in the WAA regime, followed by precip chances continuing due to the
shortwave trof moving eastward out of the high plains later this
evening. These showers could also aid in mixing down some of the
stronger wind speeds through the day today.

Both GFS and NAM indicating just a few hours with some weak
instability in the column in the midnight to 3am timeframe as the
stronger lift and cold pool aloft move over the eastern part of the
state. Have left thunder out at this time given small window, but
is worth mentioning here. As trof moves eastward, cooler air moves
in behind and lows fall into he 20s to middle 30s.

.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN DEC 20 2015

On Monday another mid level trough tracks over the central US, which
should not have much effect on the overall weather. Highs will be
cooler in the mid to upper 40s. On Tuesday return flow quickly
develops as yet another shortwave approaches from the west, which
will allow temperatures to warm back into the 50s. This shortwave
trough appears to deepen Tuesday night as it passes over the
forecast area. Increased moisture and lift as well as an advancing
cold front could support rain Wednesday morning and into the
afternoon. This precip appears to stay confined to portions of
eastern KS. Towards the end of the week a few of the models continue
to bring out weak shortwaves that could cause light precip, but
confidence in timing and location is low at this point. Models
continue to show a strong system over the southern Rockies over the
weekend, but also continue to struggle on how to evolve that
system.

.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1133 PM CST SUN DEC 20 2015

Showers and embedded TS will impact TAF sites between now and
around 09Z, ending at MHK slightly before that time. A cold front
with winds shifting out of the northwest will impact MHK near
0730Z and TOP/FOE between 09Z and 10Z. MVFR cigs are likely to
persist through this period and into the morning hours with an
expectation to scatter in the late morning to early afternoon time
frame.

.TOP Watches/Warnings/Advisories...
NONE.
&&

UPDATE...Barjenbruch
SHORT TERM...67
LONG TERM...Sanders
AVIATION...Barjenbruch

AREA FORECAST DISCUSSION

NWS JACKSON KY

101 PM EST MON DEC 21 2015

.UPDATE...
ISSUED AT 101 PM EST MON DEC 21 2015

MADE MINOR ADJUSTMENTS TO THE FORECAST BASED ON MID DAY OBS...BUT
WITH NO SUBSTANTIVE CHANGE TO THE OVERALL FORECAST.

UPDATE ISSUED AT 1125 AM EST MON DEC 21 2015

FIRST ROUND OF PRECIP HAS EXITED TO THE EAST...AND ANOTHER ROUND
IS HEADING IN FROM THE WEST. HAVE MADE MINOR UPDATES TO GRIDS FOR
THE TIMING. WITH CLOUDS AND PRECIP...TEMPS ARE RISING A BIT SLOWER
THAN WAS FORECAST. HAVE KNOCKED DOWN AFTERNOON HIGHS SLIGHTLY.

UPDATE ISSUED AT 846 AM EST MON DEC 21 2015

AN AREA OF LIGHT RAIN IS MOVING EAST ACROSS THE REGION...BUT IS
GRADUALLY DIMINISHING AS IT MOVES INTO DRIER AIR. HAVE UPDATED THE
GRIDS FOR TIMING OF THIS PRECIP. HAVE ALSO BLENDED EARLY MORNING
OBSERVED TEMPS/DEW POINTS INTO THE DAYTIME FORECAST.

UPDATE ISSUED AT 620 AM EST MON DEC 21 2015

A LINE OF MEASURABLE RAIN SHOWERS IS MAKING STEADY PROGRESS
THROUGH CENTRAL KENTUCKY AND WILL BE IN HERE SHORTLY AFTER 12Z.
WILL UPDATED THE POPS TO BETTER TIME THIS FEATURE. ALSO...SOME OF
THE EASTERN VALLEYS ARE STILL IN THE 30S...BUT MOST OF THE AREA IS
SEEING MID AND UPPER 40S OUT THERE FOR TEMPERATURES. WILL ALSO
ADJUST THESE PER THE LATEST SHORTBLEND GUIDANCE...CURRENT OBS...
AND TRENDS. THESE UPDATED GRIDS WILL BE SENT TO THE NDFD AND WEB
SERVERS.

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM EST MON DEC 21 2015

08Z SFC ANALYSIS SHOWS A RELATIVELY TIGHT PRESSURE GRADIENT OVER
KENTUCKY BETWEEN HIGH PRESSURE RETREATING TO THE EAST WHILE DEEP
LOW PRESSURE MOVES INTO THE CENTRAL PLAINS. THIS GRADIENT...IN
ADDITION TO A LAYER OF THICK HIGH CLOUDS...IS SUPPORTING A MILDER
NIGHT ACROSS EAST KENTUCKY WITH READINGS IN MOST PLACES IN THE MID
40S. HOWEVER...SOME OF THE FAR EASTERN VALLEY ARE SHELTERED ENOUGH
THAT THEY HAVE MADE IT TO NEAR FREEZING. EXPECT THESE TO MIX OUT
BEFORE DAWN AND QUICKLY RISE INTO THE MID 40S WHEN THE WINDS PICK
UP FROM THE SOUTH AT 5 TO 10 MPH. MEANWHILE...DEW POINTS ARE
GENERALLY IN THE MID TO UPPER 20S THROUGHOUT EAST KENTUCKY EARLY
THIS MORNING WITH ANY RETURNS SHOWING UP ON RADAR TOO WEAK TO MAKE
IT TO THE SFC GIVEN THE DRY LOW LAYERS.

THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A FLAT SOUTHEAST RIDGE
MOVING OFF TO THE EAST IN THE FACE OF A PAIR OF COMPACT SHORTWAVES
ROLLING PAST TO THE NORTHWEST OF THE JKL CWA. THE FIRST WILL BE
WEAKENING AS IT MOVES INTO THE NORTHERN OHIO VALLEY FROM THE
SOUTHERN PLAINS LATER TODAY...THOUGH SOME WEAK ENERGY IS MOVING
OVERHEAD CURRENTLY...AS WELL. AFTER A BRIEF REBUILD OF THE RIDGE
THE NEXT MID LEVEL WAVE CROSSES INTO THE CENTRAL OHIO VALLEY BY
DAWN TUESDAY...MAINTAINING ITS STRENGTH BETTER. THE RIDGE WILL
THEN HOLD ON TOUGH SOUTHEAST OF KENTUCKY WHILE THE BROAD SOUTHWEST
FLOW CONTINUES THROUGHOUT THE REGION AND ENERGY STARTS TO
RECHARGE TO THE SOUTHWEST. GIVEN THE MODEL AGREEMENT...HAVE AGAIN
FAVORED SOLUTIONS FROM THE HIGHER RESOLUTION HRRR AND NAM12...WITH
RESPECT TO WEATHER DETAILS.

SENSIBLE WEATHER WILL FEATURE A MILD START FOR MOST TODAY...ASIDE
FROM THE DEEP...SHELTERED VALLEYS IN THE EAST. AN
APPROACHING...BUT STALLING...COLD FRONT WILL PROVIDE A GLIDE PATH
FOR WAVES OF MOISTURES TO MOVE OVER EASTERN KENTUCKY DURING THE
SHORT TERM PORTION OF THE FORECAST AND BEYOND. LOOK FOR A WEAK ONE
TO PASS THROUGH LATER TODAY WITH A DECENT CHANCE FOR SHOWERS...
HOWEVER...AFTER A SHORT LULL...ANOTHER STRONGER AND WETTER WAVE
WILL PASS THROUGH TONIGHT INTO TUESDAY MORNING. PERSISTENT SOUTH
TO SOUTHWEST WINDS WILL KEEP TEMPERATURES WARM THROUGH THE MIDDLE
OF WEEK AND BEYOND...AS WELL. HIGHS TODAY WILL BE IN THE MID TO
UPPER 50S FOR MOST PLACES WITH LOW 60S ON TAP FOR TUESDAY. WE ARE
LOOKING FOR GENERALLY JUST A FEW TENTHS OF AN INCH OF RAINFALL
TODAY FOLLOWED BY A QUARTER TO A HALF AN INCH OF ACCUMULATION
TONIGHT WITH ANOTHER TENTH OR SO POSSIBLE DURING THE DAY TUESDAY.

FOR TEMPERATURES AND DEW POINTS...HAVE AGAIN STARTED WITH THE
SHORTBLEND GRIDS INTO TONIGHT FOLLOWED BY THE SUPERBLEND THROUGH
THE DAY TUESDAY. ONLY MADE MINOR CHANGES TO THE TEMPERATURES GIVEN
THE MOIST...CLOUDY...AND LIKELY WELL MIXED ENVIRONMENT IN PLACE
FOR THE SHORT TERM. AS FOR POPS...ENDED UP MOST SIMILAR TO THE
MET VALUES FOR TODAY INTO TUESDAY...THOUGH THE MAV IS NOT FAR
OFF...EITHER.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EST MON DEC 21 2015

RECORD BREAKING WARMTH ALONG WITH SEVERAL PERIODS OF RAIN WILL
CONTINUE TO HIGHLIGHT THE WEATHER FORECAST AS WE HEAD TOWARDS AND
PAST CHRISTMAS.

THE PERIOD WILL START WITH A SHORTWAVE TROUGH MOVING UP THE SPINE OF
THE APPALACHIANS. WITH THE STALLED FRONTAL BOUNDARY TO OUR
NORTHWEST...WE SHOULD SEE MOISTURE INCREASE AS THIS SYSTEM SPREADS
NORTHWARD TUESDAY NIGHT. THIS WILL LEAD TO QUICKLY INCREASING RAIN
CHANCES. THE BULK OF THE RAIN SHOULD COME PRIOR TO DAYBREAK...WITH
THE WAVE DEPARTING QUICKLY TO THE NORTH. THIS WILL SET UP A
POTENTIAL DRY START TO THE DAY. DESPITE THE CLOUDS...TEMPERATURES
WILL LIKELY CLIMB CLOSE TO 70...LIKELY ECLIPSING A FEW RECORDS. RAIN
CHANCES WILL INCREASE AS WE HEAD INTO THE EVENING HOURS AS A
SHORTWAVE TROUGH PUSHES INTO THE GREAT LAKES...HELPING TO PUSH A
COLD FRONT ACROSS THE OHIO RIVER VALLEY. MODELS ARE SHOWING
CONSISTENT SIGNS OF WIDESPREAD RAIN AS THIS FRONT APPROACHES THE
AREA...SO WILL GO WITH CATEGORICAL RAIN CHANCES. IN ADDITION...MID
LEVEL LAPSE RATES WILL STEEPEN UP A BIT AHEAD OF THE FRONT...SO PLAN
TO INCLUDE A SLIGHT THREAT FOR SOME THUNDER THROUGH FROM WEDNESDAY
EVENING THROUGH THE OVERNIGHT HOURS. THE FRONT WILL LIKELY NOT MAKE
IT THROUGH THE AREA AND STALL BEFORE IT REACHES EASTERN
KENTUCKY...WITH RAIN CHANCES LIKELY LINGERING THROUGH MUCH OF
CHRISTMAS EVE...ESPECIALLY IN THE SOUTHEAST. RECORDS COULD
POTENTIALLY BE REACHED ON THURSDAY AS WELL IF THE RAIN EXITS EARLY
ENOUGH ALLOWING TIME FOR OUR TEMPERATURES TO RECOVER.

MODEL UNCERTAINTY GREATLY INCREASES CHRISTMAS MORNING THROUGH THE
FOLLOWING WEEKEND. WHILE CONFIDENCE IS LOW...GENERAL EVOLUTION
WOULD SUPPORT A WARM FRONT LIFTING NORTH ACROSS THE AREA ON
CHRISTMAS OR FRIDAY NIGHT...WITH ANOTHER SURGE OF WIDESPREAD
RAIN. THIS FRONT WILL THEN STALL OR CONTINUE MOVING NORTH THIS
WEEKEND WITH EVEN WARMER TEMPERATURES SPREADING NORTH FOR THE
WEEKEND. ONCE AGAIN...RECORD TEMPERATURES WILL BE POSSIBLE
SATURDAY THROUGH MONDAY AS WE COULD EASILY REACH THE MID TO UPPER
60S EACH DAY AND LIKELY END UP IN THE LOWER 70S FOR A FEW OF THE
DAYS IF CLOUDS DISSIPATE ENOUGH. DEPENDING HOW FAR NORTH THE FRONT
MOVES WILL DETERMINE HOW MUCH RAIN WE SEE OVER THE WEEKEND. ECMWF
LIFTS THE FRONT WELL NORTH...KEEPING MUCH OF KENTUCKY DRY FROM
LATE SATURDAY THROUGH MONDAY. GFS IS FARTHER SOUTH AND WOULD KEEP
SOME RAIN CHANCES OVER THE AREA. FOR NOW...WILL KEEP SOME RAIN
CHANCES IN THE FORECAST...BUT TREND THE FORECAST WARMER FOR THE
WEEKEND. IT LOOKS LIKE THE WARMTH MAY HOLD THROUGH THE END OF THE
YEAR.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1251 PM EST MON DEC 21 2015

CONDITIONS WERE OVERCAST BUT VFR AT TAF ISSUANCE. AN AREA OF
SHOWERS WAS ABOUT TO MOVE INTO THE REGION FROM THE NW...WITH
LOCALIZED MVFR. THIS AREA OF PRECIP WILL CONTINUE TO SINK SE
THROUGH THE AFTERNOON. A MORE SIGNIFICANT ROUND OF SHOWERS IS
EXPECTED TONIGHT...DEVELOPING FROM FROM SOUTH TO NORTH BETWEEN
ABOUT 00Z AND 06Z. A GENERALIZED REDUCTION TO MVFR IS EXPECTED
WITH THE SHOWERS TONIGHT...WITH SOME VARIATION AT TIMES. MUCH OF
THE PRECIPITATION SHOULD TAPER OFF TOWARD DAWN...BUT MVFR AND
LOCALIZED IFR CONDITIONS WILL LIKELY LINGER THROUGH THE REST OF
THE PERIOD.

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...HAL/GREIF
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...HAL

AREA FORECAST DISCUSSION

National Weather Service Paducah KY

1154 AM CST MON DEC 21 2015

.UPDATE...
Issued at 1154 AM CST MON DEC 21 2015

Have updated the public forecast this morning mainly to lower
PoPs, as the forcing is primarily in the very lowest layers, so
drizzle or light showers are the main precipitation types through
the remainder of the day. There may be an uptick in precipitation
over west Kentucky this evening, as an upper-level disturbance and
weak cold front move through the area.

Cannot rule out a stray TSRA over west Kentucky this afternoon,
but with low overcast skies, instability will be difficult to
come by. If there is any thunder it would be most likely over
west Kentucky as the cold front approaches later this evening.

Went through the night and into Tuesday morning on sky grids, as
it appears that very low overcast conditions will be the rule over
most of the area both ahead of and behind the wind shift.

The AVIATION section has been updated for the 18Z TAF issuance.

.SHORT TERM...(Today through Wednesday night)
Issued at 305 AM CST MON DEC 21 2015

With a broad ridge in the Central Pacific and a series of
shortwaves expected to dig and rotate around a broad trough in the
southwest U.S. Unfortunately, this places the WFO PAH forecast
area in a broad southwesterly flow aloft, subject to frequent
instrusions of sharper lapse rates from passing upper level jet
dynamics and low level moist/warm advection scenarios.

The last 24 hours has seen a more dramatic (but not totally
unexpected) shift of better instability into the WFO PAH forecast
area. Enhanced convective activity over Western MO at this time is
just better evidence of the increased shear aloft and instability.

For the short term, blended the higher resolution HRRR explicit
model convective suite with the broader ECMWF/Canadian/GFS to
account for precipitation chances within and across several hours.
Added a wing of isolated thunderstorm chances riding up the
southeast MO foothills and into Southwest IL toward the I-64
corridor through the noon hour and the instability works northeast
with the approaching wave and slowing and weakening cold front.

The trend introduced yesterday of a break in the convective
activity late tonight and into Tuesday continues to be supported
as instability and moisture are lacking. However, this is short-
lived as the next shortwave (much more amplified in the 00z Monday Canadian
and GFS deterministic guidance versus the ECMWF) provides enough
ageostrophic response to lower pressures and reform the frontal
boundary, as well as sharpen moisture/theta-e advection back
northward late Tuesday afternoon and evening. The proximity of the
core of the stronger winds and instability should begin to support
sufficient updrafts for upright convection (thunderstorms). These
will advect northeast from Arkansas and Tennessee fairly quickly
by daybreak on Wednesday.

A strong enough gradient of moisture, shear, instability will be
in place Wednesday afternoon and evening to support a short
episode of enhanced convection and minor severe potential. Some of
this will be dependent on the degree of convection in the lower
Mississippi Valley impacting the degree and quality moisture
advection into the area.

Did not due a good job of temporal temperature trends in the light
of warm advection yesterday. Somewhat difficult to adequately
depict non-diurnal temperature trends. Temperatures on Wednesday
reflect some minor breaks in the cloud cover combined with strong
warm air advection. Could have gone a couple of degrees higher,
but timing of convection and cloud debris creates greater
uncertainty for seeing temperatures 25-30 degrees above normal at
this time.

.LONG TERM...(Thursday through Sunday)
Issued at 305 AM CST MON DEC 21 2015

An unsettled pattern is forecast in the long term. The 21/00z GFS
and 20/12z ECMWF were a pretty good match with the h5 pattern.
The new 21/00z ECMWF is also in line. Having said that, there have
been considerable run to run continuity issues prior, especially
with the evolution of a closed low over the SW U.S., and its effects
on the steering flow across our area, and resultant frontal
position, which is important with respect to PoPs. Therefore, the
uncertainty factor involved means keeping PoPs more broad brush
spatially with slightly lower values farther out in time.

For Thursday into Thursday evening (Christmas Eve), will carry a dry
forecast. The ECMWF continues to develop showers into southern
sections of the CWFA before daybreak Christmas. The other models do
not. Have slight chances to cover this early morning chance. PoPs
increase from south to north Friday through Friday night, with a
thunder chance also in play. Saturday into Sunday, the general
depiction is best chance PoPs will shift to NW sections of the CWFA
and lower across the SE (west KY) as the upper steering flow backs.
Will continue to carry thunder through the duration for the most
part as elevated instability and favorable mid level lapse rates
are maintained in both the ECMWF and GFS. Some locally heavy rain
cannot be ruled out, but still too soon as far as the details
including placement and amounts.

There continues to be a moderate spread with respect to temperatures
Friday and beyond, depending on the period. To minimize potential
errors, incorporated persistence with the latest Ensemble MOS
numbers. We incorporated Raw Model output where MOS is least likely
to deviate from its climo aspect as well. Overall, above normal
temperatures will be the rule.

.AVIATION...
Issued at 1154 AM CST MON DEC 21 2015

IFR ceilings will gradually work eastward across the region this
afternoon, and then as a cold front approaches late this evening
and overnight, ceilings will lower to LIFR levels. The cold front
will have a brief wind shift to west northwest, but it will
basically wash out over the region early Tuesday and a southeast
wind will develop late Tuesday morning. Could see periodic MVFR
light rain this afternoon mainly at KEVV and KOWB, but the best
chance of precipitation appears to be just ahead of the cold front
late this evening into the overnight hours when drizzle or shower
activity will be possible. Cannot even rule out a TS at KOWB.
Ceilings should improve quickly by late morning.

.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

UPDATE...DRS
SHORT TERM...Smith
LONG TERM...CN
AVIATION...DRS

AREA FORECAST DISCUSSION

NWS JACKSON KY

1251 PM EST MON DEC 21 2015

.UPDATE...
ISSUED AT 1125 AM EST MON DEC 21 2015

UPDATE ISSUED AT 846 AM EST MON DEC 21 2015

UPDATE ISSUED AT 620 AM EST MON DEC 21 2015

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM EST MON DEC 21 2015

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EST MON DEC 21 2015

RECORD BREAKING WARMTH ALONG WITH SEVERAL PERIODS OF RAIN WILL
CONTINUE TO HIGHLIGHT THE WEATHER FORECAST AS WE HEAD TOWARDS AND
PAST CHRISTMAS.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1251 PM EST MON DEC 21 2015

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...HAL/GREIF
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...HAL

AREA FORECAST DISCUSSION

NWS JACKSON KY

1125 AM EST MON DEC 21 2015

.UPDATE...
ISSUED AT 1125 AM EST MON DEC 21 2015

UPDATE ISSUED AT 846 AM EST MON DEC 21 2015

UPDATE ISSUED AT 620 AM EST MON DEC 21 2015

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM EST MON DEC 21 2015

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EST MON DEC 21 2015

RECORD BREAKING WARMTH ALONG WITH SEVERAL PERIODS OF RAIN WILL
CONTINUE TO HIGHLIGHT THE WEATHER FORECAST AS WE HEAD TOWARDS AND
PAST CHRISTMAS.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM EST MON DEC 21 2015

AN APPROACHING COLD FRONT WILL BRING IN A DECK OF MID LEVEL CIGS
EARLY IN THE PERIOD. BETWEEN 12 AND 14Z...THOUGH...RAIN SHOWERS
WILL BEGIN MOVING INTO THE WESTERN TAF SITES...SPREADING EASTWARD
AS CLOUDS CONTINUE TO LOWER TO NEAR MVFR CONDITIONS. EXPECT RAIN
CHANCES AND MVFR CIGS TO INCREASE THROUGHOUT THE REST OF THE
AFTERNOON...WITH PREVAILING RAIN EXPECTED BETWEEN 14 AND 19Z.
AFTER A LULL ANOTHER ROUND OF SHOWERS WILL BE POSSIBLE LATER
TONIGHT. WINDS WILL INCREASE FROM THE SOUTH TO SOUTHWEST THIS
MORNING AND GUST UP TO 20 KNOTS THE BULK OF THE DAY...ESPECIALLY
DURING ANY OF THE HEAVIER RAIN SHOWERS.

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF

AREA FORECAST DISCUSSION

NWS JACKSON KY

846 AM EST MON DEC 21 2015

.UPDATE...
ISSUED AT 846 AM EST MON DEC 21 2015

UPDATE ISSUED AT 620 AM EST MON DEC 21 2015

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM EST MON DEC 21 2015

08Z SFC ANALYSIS SHOWS A RELATIVELY TIGHT PRESSURE GRADIENT OVER
KENTUCKY BETWEEN HIGH PRESSURE RETREATING TO THE EAST WHILE DEEP
LOW PRESSURE MOVES INTO THE CENTRAL PLAINS. THIS GRADIENT...IN
ADDITION TO A LAYER OF THICK HIGH CLOUDS...IS SUPPORTING A MILDER
NIGHT ACROSS EAST KENTUCKY WITH READINGS IN MOST PLACES IN THE MID
40S. HOWEVER...SOME OF THE FAR EASTERN VALLEY ARE SHELTERED ENOUGH
THAT THEY HAVE MADE IT TO NEAR FREEZING. EXPECT THESE TO MIX OUT
BEFORE DAWN AND QUICKLY RISE INTO THE MID 40S WHEN THE WINDS PICK
UP FROM THE SOUTH AT 5 TO 10 MPH. MEANWHILE...DEWPOINTS ARE
GENERALLY IN THE MID TO UPPER 20S THROUGHOUT EAST KENTUCKY EARLY
THIS MORNING WITH ANY RETURNS SHOWING UP ON RADAR TOO WEAK TO MAKE
IT TO THE SFC GIVEN THE DRY LOW LAYERS.

FOR TEMPERATURES AND DEWPOINTS...HAVE AGAIN STARTED WITH THE
SHORTBLEND GRIDS INTO TONIGHT FOLLOWED BY THE SUPERBLEND THROUGH
THE DAY TUESDAY. ONLY MADE MINOR CHANGES TO THE TEMPERATURES GIVEN
THE MOIST...CLOUDY...AND LIKELY WELL MIXED ENVIRONMENT IN PLACE
FOR THE SHORT TERM. AS FOR POPS...ENDED UP MOST SIMILAR TO THE
MET VALUES FOR TODAY INTO TUESDAY...THOUGH THE MAV IS NOT FAR
OFF...EITHER.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EST MON DEC 21 2015

RECORD BREAKING WARMTH ALONG WITH SEVERAL PERIODS OF RAIN WILL
CONTINUE TO HIGHLIGHT THE WEATHER FORECAST AS WE HEAD TOWARDS AND
PAST CHRISTMAS.

MODEL UNCERTAINTY GREATLY INCREASES CHRISTMAS MORNING THROUGH THE
FOLLOWING WEEKEND. WHILE CONFIDENCE IS LOW...GENERAL EVOLUTION
WOULD SUPPORT A WARM FRONT LIFTING NORTH ACROSS THE AREA ON
CHRISTMAS OR FRIDAY NIGHT...WITH ANOTHER SURGE OF WIDESPREAD RAIN.
THIS FRONT WILL THEN STALL OR CONTINUE MOVING NORTH THIS WEEKEND
WITH EVEN WARMER TEMPERATURES SPREADING NORTH FOR THE WEEKEND. ONCE
AGAIN...RECORD TEMPERATURES WILL BE POSSIBLE SATURDAY THROUGH MONDAY
AS WE COULD EASILY REACH THE MID TO UPPER 60S EACH DAY AND LIKELY
END UP IN THE LOWER 70S FOR A FEW OF THE DAYS IF CLOUDS DISSIPATE
ENOUGH. DEPENDING HOW FAR NORTH THE FRONT MOVES WILL DETERMINE HOW
MUCH RAIN WE SEE OVER THE WEEKEND. ECMWF LIFTS THE FRONT WELL
NORTH...KEEPING MUCH OF KENTUCKY DRY FROM LATE SATURDAY THROUGH
MONDAY. GFS IS FARTHER SOUTH AND WOULD KEEP SOME RAIN CHANCES OVER
THE AREA. FOR NOW...WILL KEEP SOME RAIN CHANCES IN THE
FORECAST...BUT TREND THE FORECAST WARMER FOR THE WEEKEND. IT LOOKS
LIKE THE WARMTH MAY HOLD THROUGH THE END OF THE YEAR.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM EST MON DEC 21 2015

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...HAL/GREIF
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF

AREA FORECAST DISCUSSION...UPDATED

NWS JACKSON KY

645 AM EST MON DEC 21 2015

.UPDATE...
ISSUED AT 620 AM EST MON DEC 21 2015

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM EST MON DEC 21 2015

08Z SFC ANALYSIS SHOWS A RELATIVELY TIGHT PRESSURE GRADIENT OVER
KENTUCKY BETWEEN HIGH PRESSURE RETREATING TO THE EAST WHILE DEEP
LOW PRESSURE MOVES INTO THE CENTRAL PLAINS. THIS GRADIENT...IN
ADDITION TO A LAYER OF THICK HIGH CLOUDS...IS SUPPORTING A MILDER
NIGHT ACROSS EAST KENTUCKY WITH READINGS IN MOST PLACES IN THE MID
40S. HOWEVER...SOME OF THE FAR EASTERN VALLEY ARE SHELTERED ENOUGH
THAT THEY HAVE MADE IT TO NEAR FREEZING. EXPECT THESE TO MIX OUT
BEFORE DAWN AND QUICKLY RISE INTO THE MID 40S WHEN THE WINDS PICK
UP FROM THE SOUTH AT 5 TO 10 MPH. MEANWHILE...DEWPOINTS ARE
GENERALLY IN THE MID TO UPPER 20S THROUGHOUT EAST KENTUCKY EARLY
THIS MORNING WITH ANY RETURNS SHOWING UP ON RADAR TOO WEAK TO MAKE
IT TO THE SFC GIVEN THE DRY LOW LAYERS.

FOR TEMPERATURES AND DEWPOINTS...HAVE AGAIN STARTED WITH THE
SHORTBLEND GRIDS INTO TONIGHT FOLLOWED BY THE SUPERBLEND THROUGH
THE DAY TUESDAY. ONLY MADE MINOR CHANGES TO THE TEMPERATURES GIVEN
THE MOIST...CLOUDY...AND LIKELY WELL MIXED ENVIRONMENT IN PLACE
FOR THE SHORT TERM. AS FOR POPS...ENDED UP MOST SIMILAR TO THE
MET VALUES FOR TODAY INTO TUESDAY...THOUGH THE MAV IS NOT FAR
OFF...EITHER.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EST MON DEC 21 2015

RECORD BREAKING WARMTH ALONG WITH SEVERAL PERIODS OF RAIN WILL
CONTINUE TO HIGHLIGHT THE WEATHER FORECAST AS WE HEAD TOWARDS AND
PAST CHRISTMAS.

MODEL UNCERTAINTY GREATLY INCREASES CHRISTMAS MORNING THROUGH THE
FOLLOWING WEEKEND. WHILE CONFIDENCE IS LOW...GENERAL EVOLUTION
WOULD SUPPORT A WARM FRONT LIFTING NORTH ACROSS THE AREA ON
CHRISTMAS OR FRIDAY NIGHT...WITH ANOTHER SURGE OF WIDESPREAD RAIN.
THIS FRONT WILL THEN STALL OR CONTINUE MOVING NORTH THIS WEEKEND
WITH EVEN WARMER TEMPERATURES SPREADING NORTH FOR THE WEEKEND. ONCE
AGAIN...RECORD TEMPERATURES WILL BE POSSIBLE SATURDAY THROUGH MONDAY
AS WE COULD EASILY REACH THE MID TO UPPER 60S EACH DAY AND LIKELY
END UP IN THE LOWER 70S FOR A FEW OF THE DAYS IF CLOUDS DISSIPATE
ENOUGH. DEPENDING HOW FAR NORTH THE FRONT MOVES WILL DETERMINE HOW
MUCH RAIN WE SEE OVER THE WEEKEND. ECMWF LIFTS THE FRONT WELL
NORTH...KEEPING MUCH OF KENTUCKY DRY FROM LATE SATURDAY THROUGH
MONDAY. GFS IS FARTHER SOUTH AND WOULD KEEP SOME RAIN CHANCES OVER
THE AREA. FOR NOW...WILL KEEP SOME RAIN CHANCES IN THE
FORECAST...BUT TREND THE FORECAST WARMER FOR THE WEEKEND. IT LOOKS
LIKE THE WARMTH MAY HOLD THROUGH THE END OF THE YEAR.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM EST MON DEC 21 2015

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF

AREA FORECAST DISCUSSION

National Weather Service Paducah KY

543 AM CST MON DEC 21 2015

.SHORT TERM...(Today through Wednesday night)
Issued at 305 AM CST MON DEC 21 2015

.LONG TERM...(Thursday through Sunday)
Issued at 305 AM CST MON DEC 21 2015

.AVIATION...
Issued at 542 AM CST MON DEC 21 2015

Following the current passage of the bands of convection this
morning and into the afternoon, the WFO PAH TAF sites will
transition from lower MVFR ceilings to periodic IFR ceilings in
advance of the approaching cold front. Frontal passage will move
near or past the kcgi and kevv TAF site in the 05z to 08z Tuesday
time frame with corresponding visibilties between 1 1/2 to 3
statute miles.

.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

SHORT TERM...Smith
LONG TERM...CN
AVIATION...Smith

AREA FORECAST DISCUSSION

National Weather Service Paducah KY

306 AM CST MON DEC 21 2015

.SHORT TERM...(Today through Wednesday night)
Issued at 305 AM CST MON DEC 21 2015

.LONG TERM...(Thursday through Sunday)
Issued at 305 AM CST MON DEC 21 2015

.AVIATION...
Issued at 516 PM CST SUN DEC 20 2015

Bulk moisture headed in/down the column will result in lowering
cigs and ultimately showers by late tonight-early tmrw for all
terminals. Inherited IFR cigs and will calibrate around that as we
extend the forecast thru the pm hours. Should see diurnal
improvement to MVFR although vicinity showers could still
impact...esp further south and east (KOWB).

.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

SHORT TERM...Smith
LONG TERM...CN

AREA FORECAST DISCUSSION

NWS JACKSON KY

330 AM EST MON DEC 21 2015

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM EST MON DEC 21 2015

08Z SFC ANALYSIS SHOWS A RELATIVELY TIGHT PRESSURE GRADIENT OVER
KENTUCKY BETWEEN HIGH PRESSURE RETREATING TO THE EAST WHILE DEEP
LOW PRESSURE MOVES INTO THE CENTRAL PLAINS. THIS GRADIENT...IN
ADDITION TO A LAYER OF THICK HIGH CLOUDS...IS SUPPORTING A MILDER
NIGHT ACROSS EAST KENTUCKY WITH READINGS IN MOST PLACES IN THE MID
40S. HOWEVER...SOME OF THE FAR EASTERN VALLEY ARE SHELTERED ENOUGH
THAT THEY HAVE MADE IT TO NEAR FREEZING. EXPECT THESE TO MIX OUT
BEFORE DAWN AND QUICKLY RISE INTO THE MID 40S WHEN THE WINDS PICK
UP FROM THE SOUTH AT 5 TO 10 MPH. MEANWHILE...DEWPOINTS ARE
GENERALLY IN THE MID TO UPPER 20S THROUGHOUT EAST KENTUCKY EARLY
THIS MORNING WITH ANY RETURNS SHOWING UP ON RADAR TOO WEAK TO MAKE
IT TO THE SFC GIVEN THE DRY LOW LAYERS.

FOR TEMPERATURES AND DEWPOINTS...HAVE AGAIN STARTED WITH THE
SHORTBLEND GRIDS INTO TONIGHT FOLLOWED BY THE SUPERBLEND THROUGH
THE DAY TUESDAY. ONLY MADE MINOR CHANGES TO THE TEMPERATURES GIVEN
THE MOIST...CLOUDY...AND LIKELY WELL MIXED ENVIRONMENT IN PLACE
FOR THE SHORT TERM. AS FOR POPS...ENDED UP MOST SIMILAR TO THE
MET VALUES FOR TODAY INTO TUESDAY...THOUGH THE MAV IS NOT FAR
OFF...EITHER.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EST MON DEC 21 2015

RECORD BREAKING WARMTH ALONG WITH SEVERAL PERIODS OF RAIN WILL
CONTINUE TO HIGHLIGHT THE WEATHER FORECAST AS WE HEAD TOWARDS AND
PAST CHRISTMAS.

MODEL UNCERTAINTY GREATLY INCREASES CHRISTMAS MORNING THROUGH THE
FOLLOWING WEEKEND. WHILE CONFIDENCE IS LOW...GENERAL EVOLUTION
WOULD SUPPORT A WARM FRONT LIFTING NORTH ACROSS THE AREA ON
CHRISTMAS OR FRIDAY NIGHT...WITH ANOTHER SURGE OF WIDESPREAD RAIN.
THIS FRONT WILL THEN STALL OR CONTINUE MOVING NORTH THIS WEEKEND
WITH EVEN WARMER TEMPERATURES SPREADING NORTH FOR THE WEEKEND. ONCE
AGAIN...RECORD TEMPERATURES WILL BE POSSIBLE SATURDAY THROUGH MONDAY
AS WE COULD EASILY REACH THE MID TO UPPER 60S EACH DAY AND LIKELY
END UP IN THE LOWER 70S FOR A FEW OF THE DAYS IF CLOUDS DISSIPATE
ENOUGH. DEPENDING HOW FAR NORTH THE FRONT MOVES WILL DETERMINE HOW
MUCH RAIN WE SEE OVER THE WEEKEND. ECMWF LIFTS THE FRONT WELL
NORTH...KEEPING MUCH OF KENTUCKY DRY FROM LATE SATURDAY THROUGH
MONDAY. GFS IS FARTHER SOUTH AND WOULD KEEP SOME RAIN CHANCES OVER
THE AREA. FOR NOW...WILL KEEP SOME RAIN CHANCES IN THE
FORECAST...BUT TREND THE FORECAST WARMER FOR THE WEEKEND. IT LOOKS
LIKE THE WARMTH MAY HOLD THROUGH THE END OF THE YEAR.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 130 AM EST MON DEC 21 2015

HIGH PRESSURE WILL REMAIN IN CONTROL ACROSS THE REGION THROUGH
THE FIRST PART OF THE TAF PERIOD...PROVIDING VFR CONDITIONS UNDER
THICKENING HIGH CLOUDS. AN APPROACHING COLD FRONT WILL BRING IN A
DECK OF MID LEVEL CIGS TOWARD DAWN. BY 14Z...THOUGH...RAIN
SHOWERS WILL BEGIN MOVING INTO THE WESTERN TAF SITES...SPREADING
EASTWARD AS CLOUDS CONTINUE TO LOWER TO NEAR MVFR CONDITIONS.
EXPECT RAIN CHANCES AND MVFR CIGS TO INCREASE THROUGHOUT THE REST
OF THE AFTERNOON...WITH PREVAILING RAIN EXPECTED BETWEEN 16 AND
21Z. WINDS WILL BE LIGHT AND VARIABLE THROUGH MID MORNING...
BEFORE INCREASING AND GUSTING UP TO 20 KNOTS OUT OF THE SOUTH
FOR THE AFTERNOON...ESPECIALLY DURING ANY OF THE HEAVIER RAIN
SHOWERS.

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF/JMW

AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

934 PM EST TUE DEC 22 2015

.SYNOPSIS...
A STEADY FEED OF MOISTURE ON THE BACK SIDE OF HIGH PRESSURE OVER
THE WESTERN ATLANTIC WILL KEEP THE UNSEASONABLY WARM AND UNSETTLED
CONDITIONS ACROSS THE AREA THROUGH THURSDAY. A WEAK COLD FRONT
APPROACHES LATE THURSDAY...THEN STALLS ACROSS THE AREA THROUGH
THE WEEKEND.

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
VRB LYRD CLDNS OVR THE FA THIS EVE. (SCT) -RA CONTG TO MOVE NE
ACRS MOSTLY NE NC ATTM. WIDESPREAD ST (CIGS 500-1500FT) MNLY ACRS
FM I 95 ON W...ALG W/ PATCHY FG. 00Z/23 RUC HAS AREA OF RA
BLOSSOMING FM SCNTRL VA S THROUGH WRN PORTION OF NC AFT
MDNGT...WHICH CONTS TO SPREAD TO THE N AND NE THROUGH THE REST OF
THE NGT. MEANWHILE...RA WILL RMN LIKELY INVOF THE CST. WILL NEED
TO MONITOR FG...ESP INLAND...THOUGH RIGHT NOW XPCG MOSTLY LO ST
OVR WIDESPREAD FG. LO TEMPS IN THE U50S TO ARND 60F.

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
SAID S/W PROGGED TO TRACK NE ALONG THE SPINE OF THE MTS WED. THIS
SYSTM TAPS COPIOUS AMTS OF GOM MSTR AND DRIVES IT NE. MSTR OFF THE
ATLNTC GETS ENTRAINED INTO THE SYSTM AS WELL. APPEARS THE BULLSEYE
FOR THE HEAVIEST RAINFALL WILL BE ACROSS THE MTS. FOR AKQ FA...THIS
WUD MOST AFFECT THE VA PIEDMONT MAINLY WEST OF I95 WHERE BTWN 1 TO
1.5 INCHES WILL BE PSBL (HIGHEST OUT NR LKU-FVX). RAINFALL TDY WAS
ARND AN INCH. AFTR THE COORD CALL AND GIVEN THE QUICK MOVMNT OF THE
HEAVIEST AXIS OF RAINFALL WED...NO FLOOD PRODUCTS WILL BE ISSUED
WITH THIS PACKAGE. THE RUNOFF WILL LIKELY END UP IN THE RIVERS
RAISING LEVELS OVER THE NEXT FEW DAYS.

AS THE BEST OMEGA LIFTS NORTH WED AFTRN...PCPN BECOMES SOMEWHAT MORE
CONVECTIVE THAN STRATIFORM GIVEN THE UNUSUAL WARM AIRMASS. NOT
MUCH INSTABILITY PROGGED...BUT CAN NOT RULE OUT ELVATED THUNDER
DRNG THE AFTR AS WAVES OF PCPN TRAVERSE EAST DUE TO LINGERING
TROFINESS. DESPITE THE CLOUDS/PCPN...TMPS APPRCH RECORD LEVELS IN
SOME AREAS. HIGHS 70-75.

MAIN LOW LIFTS NORTH INTO SRN NEW ENGLAND WED NITE. COPIOUS AMTS OF
MSTR REMAIN ACROSS THE FA DUE TO WEAK DISTURBANCES MOVG NE. TSCTNS
LOADED WITH ENUF MSTR TO KEEP CHC/LIKELY POPS GOING. FOG WILL BECOME
AN ISSUE ONCE AGAIN. WARM AND RTHR HUMID WITH LOWS IN THE M-U60S.

MODELS SHOWING AKQ FA IN A WARM SECTOR SCENARIO FOR X-MAS EVE AHEAD
OF THE APPRCHG BNDRY TO THE NW. NOT MUCH SPRT FOR PCPN UNTIL THE
AFTRN WHERE SCT CONVECTION IS PSBL GIVEN THE AVAILABLE MSTR AND
ADVANCING BNDRY. HIGHS WILL ALL DEPEND ON HOW MUCH SUN DVLPS...BUT
ALL DATA SHOWING SUMMER LIKE READINGS WITH HIGHS 75-80. IT IS NOT A
QUESTION ON WHETHER WE SET NEW RECORD HIGH TMPS...BUT BY HOW MUCH???
WILL FEEL MORE LIKE LABOR DAY THAN X-MAS EVE.

CHC POPS THU NITE ALONG WITH MORE FOG PTNTL AS THE BNDRY WEAKENS BUT
LINGERS ACROSS THE AREA. WARM AND HUMID ONCE AGAIN WITH LOWS U50S
NORTH TO M60S SOUTH.

MODELS DIFFER FRI ON JUST WHERE THE BNDRY ENDS UP. CONSENSUS IS FOR
IT TO SAG SOUTH AS A BKDR COLD FRNT TO NE THE VA/NC BORDER. ENUF
MSTR TO KEEP CHC POPS IN FCST. NOT AS WARM...BUT STILL WELL ABV
NRML. WINDS TURN NORTH FOR A SHORT TIME ALLOWING SOMEWHAT COOLER
AIR TO FILTER SOUTH. HIGHS RANGE FROM THE M-U60S OVER THE ERN
SHORE...L- M70S ELSEWHERE. THESE VALUES FALLING JUST SHY OF THE
RECORD HIGHS FOR X-MAS DAY.

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIOD WILL FEATURE A CONTINUATION OF WARM TEMPS AND
CHANCES FOR SHOWERS. RIDGING OVER THE SOUTHEASTERN STATES WILL
PREVENT SIGNIFICANT AIR MASS CHANGES. A WEAK FRONTAL BOUNDARY WILL
BE OVER THE MID ATLANTIC STATES DURING THE LONG TERM PERIOD. THERE
IS GENERALLY A 30 PERCENT CHANCE FOR PCPN ALTHOUGH THESE SHOWERS
CHANCES DROP OFF SATURDAY NIGHT AND SUNDAY AND THEN INCREASE ONCE
AGAIN SUNDAY NIGHT THROUGH TUESDAY. PCPN IS NOT EXPECTED TO BE
WIDESPREAD.

HIGH TEMPERATURES WILL GENERALLY RUN IN THE 60S TO LWR 70S EXCEPT
EXCEPT UPR 50S TO 60S ON MONDAY. LOWS ARE FORECAST TO RANGE IN THE
UPR 40S TO 50S NORTH PORTIONS AND 50S TO NEAR 60 PORTIONS.

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
CONDS DETERIORATE THIS EVENG/OVRNGT AS CIGS DROP TO IFR/LIFR AS
WELL AS AREAS OF FOG PSBL WITH A WARM/MOIST AIRMASS IN PLACE.
CHANCES OF RAIN INCREASE THRU THE LATE OVRNGT HRS AS WELL.

PERIODS OF SHOWERS WITH PSBL IFR WILL CONTINUE WED...WITH
DECREASING CHANCES THURSDAY. EXPECT WIND GUST UP TO 20KT ACROSS
THE AREA DUE TO THE STRENGTHENING PRESSURE GRADIENT AHEAD OF THE
DEVELOPING LOW.

OUTLOOK...A WEAK FRONTAL BOUNDARY WILL BE IN THE VICINITY OF THE
MID ATLANTIC STATES BEGINNING FRIDAY. ASIDE FROM PCPN...PATCHY IFR
CONDITIONS WILL BE PSBL IN THE OUTLOOK PERIOD DURING THE PREDAWN
THROUGH MID MORNING HOURS THU/FRI DUE TO LOW STRATUS AND FOG (BUT
SHOULD NOT BE AS WIDESPREAD AS WED MORNING).

.MARINE...
SOUTH TO SOUTHWEST WINDS WILL PREVAIL OVER THE MARINE AREA
THROUGH EARLY FRIDAY. SEAS IN THE NORTHERN COASTAL WATERS HAVE
FALLEN BELOW 5 FT.

THE PRESSURE GRADIENT TIGHTENS LATE WEDNESDAY AS MESO SCALE LOW
PRESSURE DEVELOPS OVER WEST VIRGINIA AS DEPICTED BY THE NAM.
SOUTHERLY WINDS ARE FORECAST TO INCREASE AND PRODUCE SCA OVER THE
BAY...LOWER JAMES AND CURRITUCK SOUND STARTING AT 18Z. SCA ALSO
STARTS IN THE COASTAL WATERS AT 21Z AS SEAS ARE EXPECTED TO BUILD TO
5 TO 6 FT. CURRENT ADVISORY S OF PARRAMORE ISLAND WILL NEED TO BE
EXTENDED NORTH WHEN THE CURRENT ADVISORY EXPIRES.

WHILE THE WINDS OVER INLAND WATERS DIMINISH ALLOWING THE SCA TO END
AROUND 06Z THURSDAY...THE SCA IN THE COASTAL WATERS WILL CONTINUE AS
SEAS STAY 5 FT OR HIGHER THROUGH MUCH OF THURSDAY.

WINDS DIMINISH FRIDAY AS A WEAK FRONTAL BOUNDARY DROPS INTO THE
REGION. PRESSURE GRADIENT WILL BE WEAK ALONG THE BOUNDARY. CURRENT
INDICATIONS HAVE SEAS BUILDING EARLY NEXT WEEK DUE TO A PROLONGED
PERIOD OF ONSHORE WINDS.

.CLIMATE...
CORRECTED
RECORD HIGH TEMPS FOR DEC 23RD:
RIC...73 IN 1990
ORF...77 IN 1990
SBY...71 IN 1990
ECG...76 IN 2013

RECORD HIGH TEMPS FOR DEC 24TH: RECORD HIGH MIN TEMPS FOR DEC 24TH:
RIC...71 IN 1988 RIC...49 IN 1979
ORF...75 IN 1891 ORF...59 IN 1891
SBY...70 IN 2014 SBY...50 IN 2014
ECG...75 IN 1990 ECG...58 IN 1956

RECORD HIGH TEMPS FOR DEC 25TH: RECORD HIGH MIN TEMPS FOR DEC 25TH:
RIC...74 IN 1955 RIC...58 IN 1964
ORF...75 IN 1964 ORF...59 IN 1964
SBY...73 IN 1932 SBY...60 IN 1964
ECG...75 IN 1955 ECG...56 IN 1964

ALL TIME HIGH TEMPS FOR DEC:
RIC...81 IN 1998
ORF...81 IN 2013
SBY...77 IN 2013

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM WEDNESDAY TO 1 AM EST THURSDAY
FOR ANZ630>634-638.
SMALL CRAFT ADVISORY FROM 4 PM WEDNESDAY TO 4 PM EST THURSDAY
FOR ANZ650-652-654-656-658.

$$
SYNOPSIS...ALB/MPR
NEAR TERM...ALB
SHORT TERM...MPR
LONG TERM...LSA
AVIATION...MAS/DAP
MARINE...LSA
CLIMATE...AKQ

AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

1151 AM EST MON DEC 21 2015

.AVIATION...

SHRAS WILL REMAIN WIDESPREAD EARLY TO MID AFTERNOON BEFORE GRADUALLY
BECOMING MORE SCATTERED IN NATURE AS VORTICITY CENTER SHIFT OVER AND
EVENTUALLY EAST OF THE REGION OVERNIGHT. SCT SHRA CHANCES WILL STILL
PERSIST TONIGHT AS A WEAKER SHORTWAVE TRACKS OVER AREA IN THE WAKE
OF THIS MAIN LEAD WAVE. IFR CEILINGS WILL ALSO PERSIST AS THIS DUAL
WAVE STRUCTURE LEADS TO AN ELONGATED LOW PRESSURE SYSTEM/TROUGH THAT
SLOWLY SHIFTS EAST THROUGH THE AREA. IN FACT...THE DIFFUSE PRESSURE
GRADIENT ALONG THE AXIS OF THIS TROUGH MAY VERY WELL LEAD TO LIFR
CONDITIONS LATER TONIGHT...MAINLY FNT/MBS AS THE TRACK OF THE LOW
MAINTAINS SSW FLOW PTK SOUTH THROUGHOUT THE NIGHT. EXPECT IMPROVED
CONDITIONS BY THE END OF THE FORECAST PERIOD AS A SHORTWAVE RIDGE
ACTS TO FORCE THIS BOUNDARY NORTH OF ALL TERMINALS TUESDAY AFTN.

FOR DTW...IFR CONDITIONS WILL PREVAIL FOR THE REST OF TODAY ON INTO
TUESDAY AS LOW PRESSURE SLOWLY TRACKS THROUGH LOWER MICHIGAN. WITH
TIME THIS AFTERNOON...WIDESPREAD SHRAS WILL SHIFT NORTH OF THE
TERMINAL AS MID LEVEL DRY SLOT BRINGS A TRANSITION TO PATCHY -DZ/BR
WITH SCT SHRAS AT TIMES.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TUESDAY
MORNING.

* HIGH CONFIDENCE IN RAIN AS PRECIPITATION TYPE.

* LOW CONFIDENCE FOR POTENTIAL IN CIGS/VSBY BELOW 200FT AND/OR 1/2SM
LATE TONIGHT.

.PREV DISCUSSION...ISSUED 315 AM EST MON DEC 21 2015

DISCUSSION...

COPIOUS AMOUNT OF UPPER LEVEL ENERGY DIVING SOUTHEAST THROUGH THE
PACIFIC NORTHWEST OVER THE NEXT SEVERAL DAYS...MAINTAINING A WET AND
ACTIVE PATTERN...WITH RECORD WARMTH LIKELY OVER SOUTHEAST MICHIGAN ON
WEDNESDAY.

PACIFIC PINEAPPLE CONNECTION ESTABLISHED THIS MORNING JUST EAST
OF MISSISSIPPI RIVER VALLEY...AND RAIN SHIELD SHOULD CONTINUE TO
BLOSSOM AS UPPER LEVEL WAVE/PV CENTER NEAR KANSAS CITY EARLY THIS
MORNING TRACKS THROUGH FAR SOUTHERN LOWER MICHIGAN THIS AFTERNOON.
WITH FAVORABLE MOISTURE AND FORCING...EXPECTING RAINFALL TOTALS
CLOSING IN ON HALF AN INCH...ESPECIALLY IF WE CAN GET ANY CONVECTIVE
ELEMENTS GOING...AS SHOWALTER INDEX DROPS DOWN TO AROUND 1 C. DID
NOTE SOME LIGHTNING STRIKES OVER EASTERN WISCONSIN YESTERDAY
EVENING...AS WELL AS ONGOING STRIKES UNDERNEATH THE CENTER...BUT
LEFT MENTION OUT OF THE FORECAST IN LINE WITH SPC DAY 1.

VERY STRONG LOW LEVEL WINDS FIELDS AROUND THIS MORNING...PARTIALLY
ARTIFACT OF SURFACE/NEAR SURFACE STABLE LAYER...AND EXPECTING LIMITED
MIXING TODAY...IN LINE WITH RAP SOUNDINGS TO KEEP WIND GUSTS IN THE
25 TO 30 KNOT RANGE...MAINLY SOUTH TOWARD OHIO BORDER...AS SURFACE
TEMPERATURES DON`T BUDGE MUCH FROM PRESENT LOW/MID 40 VALUES.

ALTHOUGH MID LEVEL DRY SLOT LOOKS TO BE MOVING THROUGH THE CWA THIS
EVENING...IT APPEARS THERE WILL BE SUFFICIENT LOW LEVEL
MOISTURE/CONVERGENCE/CYCLONIC FLOW TO MAINTAIN SOME LIGHT
RAINFALL OR DRIZZLE AT THE VERY LEAST. COLD ADVECTION AND WESTERLY
WINDS DEVELOPING LATE TONIGHT WILL ATTEMPT TO DRY THE LOW LEVELS
OUT...BUT WITH STRENGTHENING/LOWERING INVERSION ON TUESDAY...WOULD
EXPECT SUFFICIENT MOISTURE TRAPPED UNDERNEATH TO MAINTAIN CLOUDY
SKIES INTO THE AFTERNOON HOURS...WITH POSSIBLE CLEARING WORKING UP
FROM THE SOUTH LATE.

AMPLIFYING LONGWAVE TROUGH AXIS OVER CENTRAL NORTH AMERICA ON
WEDNESDAY...RESULTING IN VERY STRONG/DEEP SOUTHWEST FLOW
PUMPING WARM AND MOIST AIRMASS INTO LOWER MICHIGAN DURING THE DAY.
LOW LEVEL JET PROGGED TO EXCEED 60 KNOTS. 925 MB TEMPS FORECASTED TO
RISE INTO THE LOWER TEENS...SUGGESTING HIGH TEMPERATURES POTENTIALLY
RISING INTO THE 60S. HOWEVER...SATURATION LOOKS TO BE OCCURRING WITH
THE ISENTROPIC ASCENT/MOISTURE TRANSPORT...AS 850 MB DEW PTS RISE TO
RECORD SETTING 10 C PER 00Z EURO...AND SEEMS LIKELY RAIN WILL
DEVELOP...LIMITING THE MAXES A BIT. EVEN A CONSERVATIVE MAX
FORECAST IN THE 55 TO 60 DEGREE RANGE WILL SET US UP TO BREAK THE
DAILY RECORDS FOR DECEMBER 23RD:

DTW 56 (1893)
FNT 55 (1982)
MBS 53 (1982)

MORE COMPELLING EVIDENCE WITH LI`S DROPPING BELOW ZERO TO INCLUDE A
THUNDER MENTION INTO WEDNESDAY EVENING AS STRENGTHENING/AGGRESSIVE
6 HR 500 MB HEIGHT FALLS (-70 TO -90 M) CENTER WORKS THROUGH THE
CENTRAL GREAT LAKES.

WITH MAIN UPPER WAVE RACING NORTHEAST INTO QUEBEC THURSDAY
MORNING...AND VEERING WINDS FAILING TO BECOME FULLY WEST-
NORTHWEST...AMOUNT OF COLD ADVECTION SPILLING INTO SOUTHERN LOWER
MICHIGAN LATE WEDNESDAY NIGHT INTO THURSDAY IS IN QUESTION. VERY
TIGHT BAROCLINIC ZONE AT 925/850 MB WILL MAKE FOR SENSITIVE
TEMPERATURE FORECAST...BUT ASSUMING 925 MB TEMPS REMAIN A COUPLE
DEGREES ABOVE ZERO...TEMPERATURES SHOULD HAVE NO PROBLEM
HOLDING IN THE UPPER 40S TO LOWER 50S.

MARINE...

AN ELONGATED AREA OF SURFACE LOW PRESSURE WILL LIFT NORTHEASTWARD
THROUGH THE WESTERN AND CENRAL GREAT LAKES TODAY. A MODEST
SOUTHWESTERLY FLOW OF 15 TO 25 KNOTS WILL REMAIN IN PLACE FROM THE
CENTRAL LAKE HURON BASIN SOUTHWARD THROUGH MUCH OF THIS AFTERNOON.
THE STRONGEST WINDS...POTENTIALLY REACHING 30 KNOTS FOR A TIME...ARE
EXPECTED TO BE IN PLACE FROM LAKE ST CLAIR SOUTHWARD INCLUDING THE
MICHIGAN WATERS OF LAKE ERIE. SMALL CRAFT ADVISORIES REMAIN IN
EFFECT FOR THE SOUTHERN MARINE AREAS TO ACCOUNT FOR THE MODERATE
PRESSURE GRADIENT. SURFACE WINDS WILL THEN VEER TO THE WEST IN THE
WAKE OF THE SURFACE LOW PRESSURE TONIGHT AS A WEAK SURFACE RIDGE
PASSES THROUGH THE REGION. A RETURN TO INCREASING MODERATE SOUTHERLY
FLOW IS EXPECTED ON WEDNESDAY AS THE NEXT LOW PRESSURE SYSTEM
ORGANIZES OVER THE NATIONS HEARTLAND.

HYDROLOGY...

AN AREA OF UPPER LEVEL LOW PRESSURE WILL DRAW MOISTURE NORTHWARD
INTO SOUTHEASTERN MICHIGAN THIS MORNING. WIDESPREAD LIGHT TO
MODERATE RAIN WILL DEVELOP BEFORE DAYBREAK AND PERSIST THROUGHOUT
MUCH OF THE DAY. HIGH CONFIDENCE EXISTS FOR RAINFALL AMOUNTS OF
BETWEEN .25 AND .50 OF AN INCH. INDICATIONS ARE THE HIGHER END OF
THE RANGE WILL OCCUR NORTH OF THE I 69 CORRIDOR.

A STRONG WARM FRONT WILL LIFT INTO THE GREAT LAKES REGION ON
WEDNESDAY AHEAD OF THE NEXT DYNAMIC UPPER LEVEL TROUGH. A RETURN OF
RECORD BREAKING WARM TEMPERATURES AND MOISTURE WILL LEAD TO ANOTHER
WIDESPREAD PRECIPITATION EVENT. LATEST FORECAST INFORMATION SUGGESTS
AS MUCH AS .50 TO .75 OF INCH OF RAINFALL WILL BE POSSIBLE WEDNESDAY
AFTERNOON THROUGH THURSDAY NIGHT.

WITH THE TIME SEPARATION BETWEEN EVENTS AND DRY ANTECEDENT
CONDITIONS...LITTLE CONCERN FOR FLOODING POTENTIAL EXISTS.

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ444.

AVIATION.....DG
DISCUSSION...SF
MARINE.......CB
HYDROLOGY....CB

YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).

AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

647 AM EST MON DEC 21 2015

.AVIATION...

THE LATEST OBSERVATIONS UPSTREAM SUPPORT THE RECENT MODELED
SOLUTIONS FOR WIDESPREAD IFR CEILINGS TO FILL IN ACROSS SOUTHEASTERN
MICHIGAN AFTER 12Z. PRECIPITATION ASSOCIATED WITH THE MAIN FRONTAL
WAVE IS EXPECTED TO FALL BETWEEN 12-20Z FROM SOUTH TO NORTH.
MIDLEVEL MOISTURE WILL THEN STRIP OUT OF THE COLUMN DURING THE
EVENING...LEAVING BEHIND A STOUT LAYER OF LOW LEVEL
MOISTURE/SATURATION UP TO 6000 FT AGL. PERSISTENCE OF SURFACE
TROUGHING ADDS SUPPORT FOR LINGERING DRIZZLE ACTIVITY THROUGHOUT
MUCH OF THE OVERIGHT. BASED ON THE GUIDANCE THERE IS NOW REASONABLY
HIGHER CONFIDENCE FOR LIFR CONDITIONS DEVELOPING OVERNIGHT. MSLP
CONFIGURATION LENDS SUPPORT FOR FOG NORTH OF AND POSSIBLY ALONG THE
GLACIAL TERRAIN...WITH SLIGHTLY BETTER SURFACE WINDS KEEPING BULK OF
SATURATION LOCKED IN AS AN LIFR CEILING THROUGH 12Z.

FOR DTW...IFR CIGS ON PACE TO BLANKET THE TERMINAL AFTER 13Z.
SURFACE WINDS ARE EXPECTED TO INCREASE THIS MORNING AS THE PRESSURE
GRADIENT TIGHTENS OVER PORTIONS OF OHIO...INTO FAR SOUTHEASTERN
MICHIGAN. THERE IS A MODERATE TO HIGH CHANCE FOR SW WIND GUSTS TO
REACH 26 KNOTS. WIDESPREAD RAIN TO MOVE OUT AROUND 19-20Z THIS
AFTERNOON. LINGERING LOW LEVEL MOISTURE THEN BRINGS INCREASING
CONCERN FOR LIFR CEILINGS TO DEVELOP AFTER 00Z TONIGHT. BETTER
SUPPORT FOR LIFR VISIBILITIES APPEARS TO REMAIN NW OF KDTW.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FEET TODAY.

* HIGH CONFIDENCE IN RAIN AS PRECIPITATION TYPE.

* LOW CONFIDENCE OR POTENTIAL IN CIGS/VSBY BELOW 200FT AND/OR 1/2SM.

.PREV DISCUSSION...ISSUED 315 AM EST MON DEC 21 2015

DISCUSSION...

DTW 56 (1893)
FNT 55 (1982)
MBS 53 (1982)

MARINE...

HYDROLOGY...

WITH THE TIME SEPARATION BETWEEN EVENTS AND DRY ANTECEDENT
CONDITIONS...LITTLE CONCERN FOR FLOODING POTENTIAL EXISTS.

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ444.

AVIATION.....CB
DISCUSSION...SF
MARINE.......CB
HYDROLOGY....CB

YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).

AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

315 AM EST MON DEC 21 2015

.DISCUSSION...

DTW 56 (1893)
FNT 55 (1982)
MBS 53 (1982)

.MARINE...

.HYDROLOGY...

WITH THE TIME SEPARATION BETWEEN EVENTS AND DRY ANTECEDENT
CONDITIONS...LITTLE CONCERN FOR FLOODING POTENTIAL EXISTS.

.AVIATION...ISSUED 1156 PM EST SUN DEC 20 2015

WIND GUSTS HAVE REMAINED FAIRLY ELEVATED THIS EVENING. SUSPECT THAT
ONCE RAIN MOVES IN THE BOUNDARY LAYER WILL COOL ENOUGH TO SUPPRESS
SOME OF THE GUSTINESS. THE DTX VAD WIND PROFILE CONTINUES TO SUPPORT
50 TO 55 KNOTS IN THE 1500 TO 2000 FT LAYER SHOWN IN LATEST MODEL
SOLUTIONS. THUS...THE LOW LEVEL WIND SHEAR WILL REMAIN IN THE TAFS
THROUGH DAYBREAK. RAIN IS QUICKLY ADVANCING IN FROM THE SOUTHWEST.
THE RAIN WILL OVERSPREAD THE TERMINALS FROM 06Z TO ROUGHLY 09Z.
CEILINGS WILL INITIALLY BE IN THE LOW END VFR RANGE. COOLING IN THE
LOW LEVELS AND ADDITIONAL MOISTURE ADVECTION DURING THE MORNING
SHOULD QUICKLY LOWER CEILINGS TO IFR. MODEL SOUNDINGS SUGGEST THIS
WILL OCCUR RATHER ABRUPTLY AROUND OR SHORTLY AFTER 12Z.

FOR DTW...THE SOUTH WINDS SHOULD DECREASE A BIT AS THE RAIN MOVES IN
/08-10Z TIME FRAME/. THIS SUGGESTS CONDITIONS WILL TRANSITION FROM
THAT OF LOW LEVEL CONVECTIVE TURBULENCE TO MORE PURE LOW LEVEL WIND
SHEAR. IT HAS THE POTENTIAL TO BE RATHER GUSTY /SOUTH WINDS/ MON
AFTERNOON. THE EARLY DAY RAINFALL MAY HOWEVER CAUSE THE BOUNDARY
LAYER TO REMAIN A LITTLE MORE STABLE THROUGH THE DAY. THIS WILL
SUPPORT WINDS A TOUCH ON THE CONSERVATIVE SIDE.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FEET TODAY.

* HIGH CONFIDENCE IN RAIN AS PRECIPITATION TYPE.

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ444.

DISCUSSION...SF
MARINE.......CB
HYDROLOGY....CB
AVIATION.....SC

YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).

AREA FORECAST DISCUSSION

NWS DULUTH MN

902 PM CST TUE DEC 22 2015

.UPDATE...
ISSUED AT 902 PM CST TUE DEC 22 2015

MINIMUM TEMPERATURE FORECAST HAS BEEN MET AND TEMPS CONINTUE TO
WARM. HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR SLOWLY RISING
TEMPS TONIGHT. WITH THE WARM TEMPS TO START WEDNESDAY...WITH
SEVERAL SPOTS ABOVE FREEZING...REMOVED THE MENTION OF FREEZING
DRIZZLE AND SLEET.

UPDATE ISSUED AT 746 PM CST TUE DEC 22 2015

SFC LOW CENTER HAS MOVED INTO SE ND AND THE LIGHT SNOW HAS ENDED.
SFC TEMPS HAVE WARMED TO 32F OR WARMER IN SEVERAL SPOTS. AS A
RESULT...HAVE REMOVED THE MENTION OF FREEZING
DRIZZLE...SLEET...DRIZZLE. STILL EXPECTING THE NEXT ROUND OF SNOW
TO DEVELOP IN NW WI AFTER MIDNIGHT. HOWEVER...SHORT TERM HIRES
MODELS INCLUDING THE DLH WRF AND HRRR ARE POINTING TO THE
POSSIBILITY OF ALL RAIN IN NW WI OR A RAIN SNOW MIX. WILL KEEP THE
PREDOMINATE PTYPE AS SNOW. MADE SOME OTHER MINOR ADJUSTMENTS.

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 413 PM CST TUE DEC 22 2015

THIS AFTERNOON A COMPACT SHORTWAVE TROF STRETCHED FROM NORTHEAST
MONTANA INTO EASTERN SOUTH DAKOTA. THE TROF WAS ACCOMPANIED BY A
POTENT CYCLONIC VORTICITY ANOMALY AND STRONG WARM AIR ADVECTION.
AT THE SURFACE A CLOSE LOW WAS CENTERED OVER NORTHERN SOUTH DAKOTA
WITH A TROF OF LOW PRESSURE STRETCHING NORTHEASTWARD INTO
NORTHWEST ONTARIO. LIGHT...TO OCCASIONALLY MODERATE...SNOW WAS
FALLING OVER EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA. SNOW
SHOWERS AND AREAS OF FREEZING DRIZZLE STRETCHED FARTHER EASTWARD
INTO NORTHEAST MINNESOTA.

THE SHORTWAVE TROF AND ASSOCIATED SURFACE LOW WILL LIFT THROUGH
NORTHWEST MINNESOTA AND INTO ONTARIO TONIGHT. PATCHY AREAS OF
FREEZING DRIZZLE ARE EXPECTED TO CONTINUE OVER MUCH OF NORTHEAST
MINNESOTA THANKS IN LARGE PART TO A WEDGE OF DRY AIR BETWEEN THE
GLACIATED CLOUDS ALOFT AND THE SATURATED NEAR-SURFACE LAYER. THE
FREEZING DRIZZLE WILL CHANGE TO OR MIX WITH LIGHT SNOW OVER MY
WESTERN ZONES AS THE SYSTEM PASSES BY. SNOW ACCUMULATION SHOULD
BE LIGHT...AS THE BEST FORCING FOR ASCENT WILL QUICKLY MOVE
THROUGH ANY SPECIFIC LOCATION. LOOK FOR SNOW TOTALS IN THE DUSTING
TO 2 INCH RANGE...WITH THE HIGHEST ACCUMULATION OVER WESTERN
PORTIONS OF KOOCHICHING COUNTY.

ATTENTION THEN SHIFTS TO WEDNESDAY...AS A SECONDARY AREA OF LOW
PRESSURE LIFTS FROM THE CENTRAL PLAINS INTO NORTHERN WISCONSIN BY
LATE WEDNESDAY AFTERNOON. DETERMINISTIC AND ENSEMBLE GUIDANCE IS
ALL POINTING TOWARD STRONG WARM AIR ADVECTION AHEAD OF AND EAST OF
THE LOW...AND SURFACE TEMPERATURES OVER WISCONSIN CLIMBING INTO
THE UPPER 30S TO LOW 40S. WITH THE WARM ADVECTION AND ISENTROPIC
ASCENT...AND ASSOCIATED PRECIPITATION... AM CONCERNED GUIDANCE MAY
BE TRENDING TOO WARM WITH SFC TEMPS. HAVE TRENDED CLOSER TO THE
DETERMINISTIC NAM GUIDANCE FOR TEMPS ON WEDNESDAY...WHICH YIELDS
30-35F FOR MAX TEMPS.

PRECIP TYPES ARE A CHALLENGE FOR WEDNESDAY. THE AIRMASS WILL BE
COLD ENOUGH FOR SNOW...WITH PATCHY FREEZING DRIZZLE...OVER MY
MINNESOTA ZONES. HOWEVER...ASCENT IS MUCH WEAKER AND DO NOT EXPECT
MORE THAN FLURRIES AND FREEZING DRIZZLE THROUGH THE AFTERNOON.
WHERE PRECIPITATION IS LIKELY TO BE HEAVIEST...MAINLY FROM THE
TWIN PORTS SOUTH ALONG I-35 AND EASTWARD...A WINTRY MIX OF SNOW...
SLEET...AND RAIN SEEMS FAVORED. SHOULD TEMPERATURES REMAIN
COOLER...AND IF THE ADVECTION ALOFT TRENDS CLOSER TO THE GFS
SOLUTION...FREEZING RAIN WOULD BE MORE OF A CONCERN. BETWEEN THE
SLEET AND SNOW POTENTIAL...THERE IS A THREAT FOR SOME ICY ROADS.
DUE TO THE LINGERING UNCERTAINTY IN PTYPE AND TEMPERATURES...HELD
OFF ON AN ADVISORY FOR NOW BUT ONE MAY BE NEEDED BY MORNING.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 413 PM CST TUE DEC 22 2015

BY WEDNESDAY EVENING THE SFC LOW WILL BE RACING OFF TO THE
NORTHEAST...AND ITS WHEREABOUTS DEPEND UPON THE MODEL AND HAVE
USED THE GFS/ECMWF COMPROMISE OF THE SLOWER MOVEMENT. THE
CYCLONIC FLOW AROUND THE LOW WILL KEEP SNOW SHOWERS GOING INTO
THURSDAY MORNING. THEY WILL END IN THE AFTERNOON. HOWEVER...THERE
COULD BE SOME ISOLATED LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH
SHORE AS 8H TEMPS OF -8C TO -10C BLOW ACROSS A +5C LAKE SUPERIOR.
HOWEVER...A WEST COMPONENT DOES NOT GIVE A VERY LONG FETCH AND IF
ANY SNOW SHOWERS DO OCCUR...THEY WILL BE ISOLATED AND LIGHT.

BROAD UPPER LEVEL TROFINESS WILL DOMINATE THE FLOW THROUGH THE
EXTENDED PERIOD. THIS WILL KEEP THE NORTHLAND IN A MILD SOUTHWEST OR
WEST AIRFLOW. ONCE THE CURRENT LOW PRESSURE PASSES THERE WILL BE
LITTLE PRECIPITATION UNTIL ABOUT SATURDAY WHEN ANOTHER LOW WILL MOVE
NORTH INTO IOWA AND ILLINOIS. AND ANOTHER ONE MAY BRING SNOW NEXT
TUESDAY.

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 534 PM CST TUE DEC 22 2015

A SFC LOW WAS MOVING INTO ND AT THE OUTSET OF THE FORECAST. THIS
RESULTED IN A SOUTHERLY FLOW OVER THE TERMINALS. PLENTY OF
IFR/MVFR CIGS WERE AFFECTING THE AREA WITH SOME PATCHY BR AND
FLURRIES. AS THE SFC LOW TRACKS NEWD THROUGH THE REST OF THE
FORECAST PERIOD...SOME PATCHY -FZDZ AND FLURRIES MAY BE FOUND.
AFTER 10Z...LIGHT SNOW WILL BEGIN TO AFFECT THE TERMINALS WITH THE
LOWEST VSBYS IN MODERATE SNOW...POSSIBLY HEAVY AT TIMES...AFFECTING
HYR AND TO A LESSER EXTENT AT DLH. OTHER TERMINALS WILL NOT HAVE
SUCH RESTRICTIVE VSBYS. THIS WILL PERSIST THROUGH THE FORECAST.

.PRELIMINARY POINT TEMPS/POPS...
DLH 30 32 22 25 / 30 70 30 10
INL 30 32 18 22 / 10 20 30 20
BRD 30 32 19 24 / 10 20 20 10
HYR 32 34 24 28 / 70 100 50 10
ASX 32 34 27 30 / 50 90 60 20

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY FOR LSZ140-141.

UPDATE...GSF
SHORT TERM...HUYCK
LONG TERM...CLC
AVIATION...GSF

AREA FORECAST DISCUSSION

NWS DULUTH MN

746 PM CST TUE DEC 22 2015

.UPDATE...
ISSUED AT 746 PM CST TUE DEC 22 2015

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 413 PM CST TUE DEC 22 2015

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 413 PM CST TUE DEC 22 2015

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 534 PM CST TUE DEC 22 2015

.PRELIMINARY POINT TEMPS/POPS...
DLH 30 32 22 25 / 30 70 30 10
INL 30 32 18 22 / 10 20 30 20
BRD 30 32 19 24 / 10 20 20 10
HYR 32 34 24 28 / 70 100 50 10
ASX 32 34 27 30 / 50 90 60 20

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY FOR LSZ140-141.

UPDATE...GSF
SHORT TERM...HUYCK
LONG TERM...CLC
AVIATION...GSF

AREA FORECAST DISCUSSION...UPDATED

NWS ST LOUIS MO

943 PM CST TUE DEC 22 2015

.UPDATE:
Issued at 927 PM CST Tue Dec 22 2015

A few adjustments to the forecast tonight...mainly to try and time
clouds a little better and to reflect precip trends shown by the
latest short range guidance. Both the RAP and HRRR are delaying
the onset of precipitation until after 10-11Z across much of the
area, so have cut back the PoPs a bit...keeping likelies out of
the forecast until 11-12Z, and then only in far southern zones and
northwest zones where guidance is showing accumulating precip.
Quickly ramp up to likely and categorical after 12Z.

Of second concern, watching fog inch toward our southeast CWFA
border. Will continue to monitor, but I may have to issue a dense
fog advisory before midnight if the fog continues to spread
northeast.

Carney

.SHORT TERM: (Through Late Tonight)
Issued at 332 PM CST Tue Dec 22 2015

Over the last few hour the low stratus has eroded rapidly in most of
the MO counties in our CWA. However, some lower clouds are
lingering over our s IL counties, with another, more persistent and
thicker cloud deck remaining anchored in the post frontal AMS from
se MO into the Ohio Valley. With a s/se component to the low level
flow continuing overnight believe that lower clouds will expand
across the eastern half of the CWA during the evening through a
combination of redevelopment with noctural cooling of the boundary
layer and/or nwd advection of Ohio Valley cloud deck. Over central
MO, the higher level cloudiness of this evening should also give way
to lower clouds after midnight as increasing southerly flow/low
level jet causes low level moisture to surge into the area.

The resultant moisture transport and isentropic ascent, combined
with larger scale UVV associated with lead shortwave ejecting ahead
of central Plains trof, should allow showers to develop after 06z in
a N/S band west of the Mississippi River that will gradually
increase in coverage and expand east with time. Although forecast
instability looks fairly meager the low level advection profile does
lead to decent lower/mid level lapse rates that would support the
idea of some elevated convection. For now I`ve maintained slight
chance of thunderstorms because of this, but evening shift will
certainly have to monitor this.

Temperatures may dip briefly this evening, before the combo of
increasing winds and clouds cause steady or slowly rising temps
during the overnight hours.

Truett

.LONG TERM: (Wednesday through Next Tuesday)
Issued at 332 PM CST Tue Dec 22 2015

(Wednesday)

Very active and unsettled weather on Wednesday as sfc low deepends
across eastern Kansas early Wednesday morning and tracks toward
southern Iowa by midday. Expect north/south oriented band of rain
showers w/ embedded thunderstorms to sweep through the area. Should
be a break during the late morning hours/early afternoon before at
least scattered thunderstorms develop along the trailing cold front.
Threat of severe thunderstorms has increased over the past 24-48
hours due to higher forecast instability. NWP guidance suggests
SBCAPE values of 500-1000+ J/kg as a break in the rainfall and
possible breaks in the clouds would help to increase the
instability...potentially even further than what is currently being
advertised. Deep-layer shear of 50-70 knots combined with the
forecast instability would be more than enough to support all forms
of severe weather. Supercells are also quite possible along/ahead of
front as deep-layer shear vector is oriented roughly 30 degrees to
cold front. Tornado threat is increased due to very high 0-1km shear
and helicity...but south/southwest sfc winds and relatively high
LCL values could be inhibiting factors to tornadic development.

(Thursday through Christmas Day)

A relatively quiet quiet period will come between Thursday and
Christmas Day. Mostly dry weaher is expected with the exception
being Christmas Day acrosss the southeastern portion of the CWA with
a chance of showers as warm advection increases at lower levels.
Temperatures both day/night will be cooler than Wednesday...but
still well above normal levels for the end of December.

(Christmas Night through Monday)

Frontal boundary that had stalled south of the CWA will move back
northward Christmas night and Saturday and bring a round of showers
and embedded thunderstorms to the region. The retreating warm front
is then forecast to stall out somewhere across the CWA and provide
the focus for widespread showers/thunderstorms through Saturday
night with moderate to potentially heavy rainfall rates. Frontal
boundary will sag back southward by Sunday morning. Temperatures
will cool and instability...even aloft...becomes negligible. Have
removed thunder wording for the Sunday period but still have
likely/categorical PoPs north of the boundary for light/moderate
rain. Sunday looks like a real chilly/raw day with high temperatures
foercast to be only in the 40s with northeast winds and rain. Sfc
system will occlude near the Arklatex region late on Sunday and
track toward north-central Missouri by Monday afternoon. Another
round of moderate to potentially heavy rainfall is likely to occur
late Sunday night/early Monday along with embedded thunderstorms
also possible. An early look at total rainfall for this event looks
to be on the order of 3 to 6 inches across the southeastern half of
the CWA...with locally higher amounts possible due to convection.
This rainfall will likely lead to additional flooding along area
rivers/streams. For more details...please see the hydrologic outlook
(ESF).

(Tuesday)

The atmosphere looks to finally quiet down next Tuesday as the
previous system moves out into southeastern Canada. Temepratures
will remain above normal on Tuesday with highs in the 40s. Some
signs of a pattern shift heading toward the New Year as longwave
ridging builds near the west coast. If this indeed occurs...at
turn toward near or below normal temperatures and drier conditions
would be more likely.

Gosselin

.AVIATION: (For the 00z TAFs through 00z Wednesday Evening)
Issued at 702 PM CST Tue Dec 22 2015

Predominantly IFR CIGs accelerating their movement to the NW will
envelope the STL metro TAF sites by 01z and eventually push on to
UIN and COU later tonight, but may be a bit more delayed due to
anticipated slight veering of steering winds from the S which will
slow the westward thrust. IFR VSBYs also exist, but deeper into
the cloud shield in western KY and far southern IL and still some
doubt as to how low VSBYs will go in STL metro and UIN later
tonight. For now, went on the conservative, optimistic side but
still a shift from previous TAF set. These clouds will prevail
until low level steering winds develop a westerly component to
them Wednesday morning and should see improvement to them into
MVFR.

A low level jet of 45-50kts will develop later this evening
initially into COU-UIN and expand into STL metro overnight and
with the strong inversion in place, will result in LLWS and have
placed in TAFs.

Showers and a few TSRA will rapidly expand into the area towards
daybreak initially into UIN and COU and then somewhat later into
STL metro. For now have handled with SHRA but may have to add TS
later. This should last for 3-4 hours.

A new round of SHRA/TSRA will try to develop later in the
afternoon Wednesday but relatively high uncertainty on how and
when, and with enough other issues to deal with in the short-term
have left this dry.

TES

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

WFO LSX

AREA FORECAST DISCUSSION

National Weather Service Kansas City/Pleasant Hill MO

936 PM CST TUE DEC 22 2015

.UPDATE...
Issued at 935 PM CST TUE DEC 22 2015

Have made some adjustments to the overnight as well as Wednesday`s
PoPs. This will be most noticeable over the west central and northern
CWA. Satellite imagery shows a shortwave trough lifting northeast
from the eastern TX Panhandle/northwest TX area with a vorticity max
near CDS. Expect scattered elevated showers to form ahead of this
feature after 06z once a narrow tongue of h8 moisture is lifted into
the region via isentropic ascent on the 295K surface. Have followed
the HRRR trend of the past 3-4 runs which is supported quite well by
the 00z NAM as well as the 18z runs of the NAM and GFS. Think we`ll
see showers break out across northwest MO first with a southward
development into the KC area. Will probably see some scattered
elevated showers also pop up well downstream across northeast MO.

Using the above models as a guide believe the deeper moisture
represented by the h7 condensation pressure deficits will be swept
northeast rather quickly and by 15zish Wednesday the more widespread
showers will have lifted out of west central and north central MO.
The deformation band of more stratiform rain now looks like it will
linger over northwest MO well into the afternoon hours.

Have also adjusted overnight temperatures to reflect a steady as she
goes to a slight upward drift.....at least until the rain forms.

.DISCUSSION...
Issued at 345 PM CST TUE DEC 22 2015

Big picture today shows the Nation dominated by a large trough who`s
axis resides across the Western Plains. The local result is a
southwest flow across the Lower Missouri River Valley which has
helped keep the cooler winter air out of our section of the Central
Plains. So, despite that fact that it was cloudy and cold this
morning, along with it being late December, we have warmed into the
40s and 50s again across the region with the help of the southeast
surface wind. Tonight, a shortwave trough, swinging through the base
of the mean longwave trough, will lift across the Central and
Northern Plains late tonight and Wednesday. Resulting warm air
advection ahead of the shortwave will kick in late tonight and
persist through much of Wednesday morning. Currently, models
advertise the rain to move to our northeast by noon Wednesday, but
showers and isolated thunderstorms may linger into the afternoon,
especially as you look farther east across Missouri. None of tonight
or Wednesday weather is expected to be severe, and rainfall totals
Wednesday are only expected to be around a few tenths at most.

For Thursday into Christmas Day...locally, across far eastern Kansas
and the northern half of Missouri, we expect it to be dry, but there
is a none-zero chance that a little precipitation might occur.
Thursday a secondary shortwave trough will follow the larger
Wednesday shortwave trough northeast across the Plains. Most models
have been keen to focus on this quick secondary shortwaves potential
to squeeze some light precipitation out. Have kept slight chance
POPs in across far northern reaches of the forecast area through
Wednesday night into Thursday; and depending on temperatures at that
time, some snow might develop. And, for Christmas Day, while it
could be overcast day, currently it looks like the daylight hours
will be dry locally, but we will be watching for rain to spread
north from southern Missouri that night, with rain persisting
through the weekend.

The weather Christmas Night, and through the weekend, is going to be
a bit of mess. Thursday and Friday we don`t have much chance of
getting wet as we are between storm inducing shortwave troughs, but
by Friday a large amplification in the flow is expected as a strong
shortwave trough digs deep into the mean CONUS trough across the
western CONUS, eventually developing a closed low over the Desert
Southwest which will slowly amble northeast across the Plains late
this weekend into next work week. ECMWF and GFS solutions have all
been pointing at this, though specifics on where the low goes and
how quickly it gets there have been all over the place, with the
ECMWF slowing and then speeding the low up significantly over the
past two model runs. For early in the event, Christmas Night into
Saturday, we will be well ahead of the closed low which will help
keep our temperatures benign for late December with high in the 40s
and 50s still possible Saturday. This means any precipitation early
on will be all liquid for our area. And, the amount of QPF the
models are spitting out indicates that a lot of rain will fall.
Currently, storm totals from Friday night through Monday night in
central Missouri are in the 4 to 6 inch range, tapering to between 1
and 2 inches in the far northwest corner of Missouri. As a result,
anticipate river and stream flooding will be an issue over the
weekend and into next week.

Otherwise, there will be an issue with precipitation type late in
the weekend and early next work week as the low ejects northeast
across the Plains. However, this far out in time, models are having
the typically hard time settling on a solution with the medium
range operational and ensemble models showing a fair amount of
spread in the solutions. So, with out any cold air in place across
our section of the country confidence in precipitation types late in
the weekend and next work week are very low, but have included some
snow and rain snow mix in parts of the Sunday through Monday night
periods.

.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 523 PM CST TUE DEC 22 2015

VFR conditions will prevail through the evening hours with increased
winds out of the southeast. Precipitation will begin to develop
overnight, with perhaps some isolated thunder. During this time,
ceilings will reduce to MVFR with diminishing conditions coming into
picture by early Wednesday morning. A shift in mid-level winds out of
the southwest will help to taper off precipitation, though low-level
moisture will bring ceilings down to IFR around 12Z. These are
expected to persist until the early afternoon as winds increase and
shift out of the northwest. Some lingering precipitation could enter
the terminal sites on the back side of the surface low, though this
should only impact KSTJ at the time.

.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&

UPDATE...MJ
DISCUSSION...Cutter
AVIATION...Welsh

AREA FORECAST DISCUSSION

NWS ST LOUIS MO

120 PM CST MON DEC 21 2015

.SHORT TERM: (Through Tuesday Afternoon)
Issued at 120 PM CST Mon Dec 21 2015

The cold front is making steady progress east across the area
with falling temperatures and a wind shift to the west-northwest.
Dry slot and breaks in the overcast allowed St. Louis to top out
at 67 degrees late this morning which tied the record for the
date that was set back in 1967. What a way to start astronomical
winter, which officially begins at 10:48 PM this evening!

Post frontal IFR stratus deck will blanket the CWA this evening and
despite the subsidence behind the storm system, the low level
moisture will be trapped under the inversion and keep the cloud deck
around tonight or allow for dense fog to develop if there is
clearing. HRRR has been very reliable in these post frontal cloud
forecasts as of late and it shows a LIFR cloud deck through at least
14Z on Tuesday.

Believe clouds or fog will try to scatter/dissipate from
southwest to northeast on Tuesday as flow becomes southerly. Have
forecast temperatures a bit cooler for Tuesday across the
northeastern half of the CWA due to this expected cloud cover.

CVKING

.LONG TERM: (Tuesday Night through Next Monday)
Issued at 120 PM CST Mon Dec 21 2015

Active weather pattern sets up Tuesday night through the
remainder of the forecast. Next shortwave and attendant surface
low/cold front is expected to approach the area from the west
Tuesday night and move across the CWA by late Wednesday evening.
Moisture advection is forecast to increase Tuesday night as the
low level jet increases and showers should be on the increase
after midnight. Can`t rule out a few rumbles of thunder as well,
given MUCAPES around 500 J/KG. This first round of "warm
advection precipitation" should move northeast by late morning on
Wednesday and depending on the amount of clearing and
destablization that can take place across the eastern half of the
CWA, severe thunderstorms may develop ahead and along the cold
front. As with almost any cold season event, the shear and
helicity values are extremely favorable for organized convection.
The question will be the surface based instabilty. The NAM is the
most bullish with around 500-750 J/KG. SPC has placed the eastern
portion of the CWA in a Marginal Risk for Day 3, and historical
analogs (St. Louis University CIPS) certainly support this. Have
introduced severe wording in the HWO and Situational Report to
account for this potential.

Needless to say temperatures will be well above average Tuesday
night and Wednesday. Some of the guidance actually has 70s on
Wednesday afternoon. I would think that is a tad too high, but we
got up to 67 degrees today so I suppose anything is possible this
winter!

The storms, if they develop, should exit rapidly to the east
Wednesday night leaving Christmas Eve and much of Christmas Day dry
and cooler (but yes, still above normal).

Attention then turns to a prolonged rain event Christmas night
through the Holiday Weekend with the prospect of flooding. The
synoptic setup is that the front that drifted to our south moves
back north and sits just to the south of us for a few days with a
classic setup for elevated convection as a deep trof and surface low
develop to our southwest. The front lifts north by early next week
with the system moving over the top of us. GFS has a maximum of
7-10 inches of rain from southwest Missouri through the St. Louis
Metro, the ECWMF has 4-6 inches, and the Central Region SuperBlend
of model data (which includes WPC) has widespread amounts of 5-7
inches. This amount of rain, even spread out over several days,
will cause local streams, creeks and rivers to flood. If
convection occurs and locally higher amounts are realized, then
flash flooding could be a possibility toward the end of the event
once the ground has been thoroughly saturated. Given these
concerns have decided to add mention of flooding in both the HWO
and Situation Report.

Temperatures will remain above normal and fluctuate depending on the
exact placement of the front during the extended portion of the
forecast.

CVKING

.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1139 AM CST Mon Dec 21 2015

Wind gusts drop off with frontal passage and ceilings fall to
MVFR. After frontal passage winds shift to the west and northwest
with ceilings dropping to IFR around midnight. Leaning toward low
clouds opposed to fog for early morning based on model guidance.
Winds shift to the south east by mid morning.

Specifics for KSTL:
Gusty winds from the southeast with scattered clouds ahead of the
frontal passage this afternoon. Wind shifts to the west and sky
becomes overcast with the passage between 20z and 22z. IFR
conditions are expected around midnight. There is a possibility
for fog but guidance as of now leans more toward a low ceiling
instead. Later shifts may need to adjust between fog and stratus.

Walsh/Kanofsky

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

WFO LSX

AREA FORECAST DISCUSSION...UPDATED

NWS BILLINGS MT

942 AM MST MON DEC 21 2015

.UPDATE...

WITH THE WARMING BEHIND THE SHORTWAVE LAST NIGHT...TEMPERATURES
DID NOT DROP AS LOW AS HAD BEEN EXPECTED...SO RAISED HIGHS THIS
AFTERNOON A COUPLE OF DEGREES. ANY CHANCE THIS MORNING FOR FOG
HAS DIMINISHED...AND HAS BEEN REMOVED FROM THE FORECAST. REIMER

.SHORT TERM...VALID FOR TDY AND TUE...

A FAST PROGRESSIVE PATTERN CONTINUES THROUGH THE SHORT-TERM
PERIOD. DUE TO THE NATURE OF THE FAST-MOVING WAVES...MODELS ARE
SHOWING DIFFERENCES IN THE HANDLING OF VARIOUS PATTERN FEATURES.

THE FIRST IN A SERIES OF SHORTWAVES WAS CROSSING THE AREA EARLY
THIS MORNING AND WAS SEEN IN WATER VAPOR IMAGERY. THIS WAVE HAD
WEAK PRESSURE FALLS AHEAD OF IT AND WEAK RISES BEHIND IT...AND HAS
CHANGED THE ORIENTATION OF THE SURFACE PRESSURE GRADIENT OVER THE
GAP FLOW AREAS TO A MORE SSW TO ENE GRADIENT. AS A RESULT OF THIS
CHANGE...THE WINDS IN KLVM AND NYE HAVE DECREASED. VISIBILITIES IN
BLOWING SNOW HAVE ALSO COME UP IN KLVM. THE GRADIENT WILL BEGIN TO
FLATTEN OUT AGAIN AROUND 18Z AHEAD OF THE NEXT WAVE...BUT WINDS
ALOFT WILL NOT BE THAT STRONG. THUS WILL CANCEL THE WIND ADVISORY
WITH THIS PACKAGE. WINDS ALOFT DO INCREASE LATE IN THE
AFTERNOON...AND IT/S NOT VERY UNSTABLE...BUT THE PRESSURE GRADIENT
DID NOT SUPPORT GOOD GAP FLOW WITH A SURFACE LOW APPROACHING FROM
THE PACIFIC NW.

REGARDING MORNING FOG...THE EASTWARD MOVING WAVE WILL CONTINUE TO
INCREASE TEMPERATURE/DEWPOINT SPREADS SO ANY FOG WILL BE SHORT-
LIVED AFTER 12Z. THE RAP SUPPORTED THIS SCENARIO AS WELL. SO HAVE
AREAS OF FOG OVER THE SE AND KSHR AREA BASED ON WEB CAMS AND
CURRENT SPREADS...BUT DO NOT ANTICIPATE THE NEED FOR A DENSE FOG
ADVISORY. SOME LIGHT SNOW OR BLOWING SNOW WAS OCCURRING ON THE
COOKE CITY WEB CAM THIS MORNING...OTHERWISE NOT SEEING ANY SNOW
OVER THE AREA AT THIS TIME. CHANCES FOR SNOW WILL INCREASE OVER
AND NEAR THE WESTERN MOUNTAINS...AS WELL AS THE NE BIG HORNS
TODAY AS THE SECOND WAVE APPROACHES...ACCOMPANIED BY ISENTROPIC
LIFT/WARM ADVECTION. DID NOT SEE MUCH ACCUMULATION BASED ON LIGHT
QPF AND TIME-HEIGHTS. THE WAVE AND ACCOMPANYING SURFACE LOW MOVE
ACROSS MT TONIGHT AND MODELS WERE NOT IN GOOD AGREEMENT ON LOW
PLACEMENT AND QPF. BEST SNOW CHANCES WILL BE OVER THE WESTERN
MOUNTAINS. GOOD LIFT AND DECENT DENDRITIC GROWTH SUPPORTED SEVERAL
INCHES OF SNOW THERE. BLENDED GOING POPS WITH CONSALL DUE TO THE
ABOVE UNCERTAINTY. PRESSURE GRADIENT BECOMES MORE FAVORABLE FOR
GAP FLOW LATE TONIGHT...HOWEVER GFS SOUNDINGS WERE VERY UNSTABLE
WHICH WILL WORK AGAINST STRONG GAP FLOW. THUS WILL KEEP WINDS
UNDER ADVISORY CRITERIA.

THE SHORTWAVE PUSHES INTO THE DAKOTAS TUE MORNING AND WEAK ENERGY
FOLLOWS THE WAVE. MODELS CONTINUED THEIR DISAGREEMENTS WITH QPF
PLACEMENT...SO BLENDED POPS WITH CONSALL...RESULTING IN HIGHEST
POPS OVER WESTERN MOUNTAINS. AIRMASS SHOULD DRY OUT LATE TUE
NIGHT. ARTHUR

.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...

EXTENDED PERIOD BEGINS WITH A TROUGH AXIS THROUGH CENTRAL
MONTANA. THE FLOW ALOFT WILL MOSTLY BE ZONAL WITH A SERIES OF WEAK
DISTURBANCES PASSING THROUGH CENTRAL MONTANA. THESE WAVES WILL
BRING WITH THEM LIKELY SNOW SHOWERS TO HIGHER TERRAIN AND WESTERN
LOCATIONS. THESE WILL IMPACT LOCATIONS IN AND WEST OF THE DIVIDE
NEAR LIVINGSTON AND COOKE CITY. A FEW OF THESE SNOW SHOWERS COULD
MAKE IT PAST THE DIVIDE BUT AM NOT EXPECTING IMPACTFUL...IF
ANY...ACCUMULATIONS THROUGH CHRISTMAS DAY.

BIGGER CHANGE IN THE WEATHER TAKES SHAPE CHRISTMAS-EVE AFTERNOON
AS PACIFIC TROUGH BEGINS TO AMPLIFY ALONG THE WESTERN US. AS THIS
FEATURE DIGS SOUTH...SFC HIGH PRESSURE SLIDES IN FROM THE
NORTHEAST AND USHERS IN MUCH COOLER AIR CHRISTMAS EVE AND
CHRISTMAS DAY. MORNING LOWS SHOULD BOTTOM OUT IN THE SINGLE DIGITS
FOR MOST LOCATIONS WITH HIGH TEMPERATURES IN THE TEENS. MOST
LOCATIONS APPEAR DRY FOR NOW BUT EXTREME SOUTHERN PARTS OF MONTANA
COULD SEE AN ISOLATED SNOW SHOWER CHRISTMAS AND EARLY SATURDAY AS
THE PACIFIC TROUGH CUTS OFF OVER UTAH AND NORTHERN COLORADO.

IN ADDITION TO THE COOLER TEMPERATURES CHRISTMAS DAY...THE
BIGGEST CONCERN REVOLVES AROUND A PERIOD OF STRONG GAP WINDS
AROUND LIVINGSTON AND BIG TIMBER. RIDGE AXIS MOVING BEHIND THE CUT
OFF LOW TO OUR SOUTH SHOULD ALLOW GOOD RADIATIONAL COOLING
CONDITIONS AND PRESSURE GRADIENTS APPEAR VERY FAVORABLE FOR TWO
PERIODS OF ELEVATED WINDS. STRENGTHENING FLOW OVER NORTHWEST
MONTANA WILL ALSO HELP INDUCE LEE-SIDE TROUGHING SATURDAY
AFTERNOON. THE FIRST EVENT WILL AFFECT LIVINGSTON SATURDAY NIGHT
AND SUNDAY MORNING...AND THE SECOND WILL BE BIG TIMBER AND
HARLOWTON AS THE GRADIENT BECOMES MORE WESTERLY SUNDAY MORNING AND
AFTERNOON. DOBBS

.AVIATION...

VFR FLIGHT CONDITIONS WILL PREVAIL ACROSS THE LOWER ELEVATIONS
TODAY. A PACIFIC DISTURBANCE WILL BRING SNOW TO THE BEARTOOTH...
ABSAROKA AND CRAZY MOUNTAINS ALONG WITH FREQUENT OBSERVATIONS THIS
AFTERNOON AND TONIGHT. LOCAL MVFR IS POSSIBLE NEAR KMLS TONIGHT
BUT VFR SHOULD PERSIST ELSEWHERE. EXPECT SW WIND GUSTS OF 30-40
KTS AT KLVM. JKL

.PRELIMINARY POINT TEMP/POPS...

TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 036 025/035 015/028 014/025 005/017 003/023 014/037
1/B 22/J 21/E 11/E 11/E 11/U 11/N
LVM 035 027/033 014/026 015/025 001/021 003/023 012/034
2/J 33/J 22/J 22/J 22/J 11/N 11/N
HDN 039 022/037 009/028 014/027 004/017 901/022 006/034
1/B 23/J 21/E 11/E 11/E 11/U 11/B
MLS 036 021/033 011/025 011/023 005/017 901/019 009/029
1/U 22/J 31/B 11/B 11/E 11/U 11/U
4BQ 038 022/036 012/029 012/027 008/020 003/021 008/030
1/B 12/J 21/B 11/B 11/E 21/U 11/U
BHK 037 021/034 015/026 011/024 006/017 001/020 007/031
1/B 12/J 32/J 11/B 11/E 11/B 11/B
SHR 036 021/036 007/028 010/025 002/019 901/024 007/034
1/B 12/J 22/J 11/B 12/J 21/U 11/B

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

$$
WEATHER.GOV/BILLINGS

AREA FORECAST DISCUSSION

NWS BILLINGS MT

323 AM MST MON DEC 21 2015

.SHORT TERM...VALID FOR TDY AND TUE...

A FAST PROGRESSIVE PATTERN CONTINUES THROUGH THE SHORT-TERM
PERIOD. DUE TO THE NATURE OF THE FAST-MOVING WAVES...MODELS ARE
SHOWING DIFFERENCES IN THE HANDLING OF VARIOUS PATTERN FEATURES.

.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...

.AVIATION...

VFR CONDITIONS SHOULD PREVAIL AT ALL TAF SITES THROUGH THE
PERIOD. THOUGH SOME MVFR/IFR FOG IS POSSIBLE FOR A VERY BRIEF
PERIOD NEAR SUNRISE AT KMLS AND KSHR. UPPER LEVEL DISTURBANCE
PUSHING EAST IS WORKING AGAINST THIS THOUGH SO AM NOT CONFIDENT
FLIGHT RULES DROP BELOW VFR. VCSH POSSIBLE AT KLVM LATE THIS
MORNING THROUGH THE AFTERNOON. MOUNTAIN OBSCURATIONS CAN BE
EXPECTED IN THE HEAVIER SHOWERS. DOBBS

.PRELIMINARY POINT TEMP/POPS...

TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 035 025/035 015/028 014/025 005/017 003/023 014/037
1/B 22/J 21/E 11/E 11/E 11/U 11/N
LVM 035 027/033 014/026 015/025 001/021 003/023 012/034
2/J 33/J 22/J 22/J 22/J 11/N 11/N
HDN 038 022/037 009/028 014/027 004/017 901/022 006/034
1/B 23/J 21/E 11/E 11/E 11/U 11/B
MLS 037 021/033 011/025 011/023 005/017 901/019 009/029
1/B 22/J 31/B 11/B 11/E 11/U 11/U
4BQ 037 022/036 012/029 012/027 008/020 003/021 008/030
1/B 12/J 21/B 11/B 11/E 21/U 11/U
BHK 037 021/034 015/026 011/024 006/017 001/020 007/031
1/B 12/J 32/J 11/B 11/E 11/B 11/B
SHR 036 021/036 007/028 010/025 002/019 901/024 007/034
1/B 12/J 22/J 11/B 12/J 21/U 11/B

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

$$
WEATHER.GOV/BILLINGS

AREA FORECAST DISCUSSION...UPDATED

NWS BILLINGS MT

932 PM MST SUN DEC 20 2015

.UPDATE...
TWO FORECAST ISSUES THIS EVENING WHICH ARE DIVIDED BY SURFACE
PRESSURE TROUGH WITH DRIER AIR TO THE WEST WITH MOIST AIR TO THE
EAST. FIRST...FOG DEVELOPING ACROSS MUCH OF EASTERN MONTANA . WE
UPDATED EARLY TO ADD THIS TO FORECAST FROM STILLWATER COUNTY
EASTWARD AND INCLUDING SHERIDAN COUNTY IN WYOMING. THIS IS ALL
EAST OF THE SURFACE TROUGH. I DO NOT ANTICIPATE BEING AS
WIDESPREAD DENSE LIKE IT WAS SUNDAY MORNING...SO HAVE HELD OFF ON
ADVISORY FOR NOW. CLOUDS MOVING OVER REGION FROM WEST MAY CAUSE
FOG TO LIFT AND DISSIPATE IN SOME AREAS LATE.

WEST OF SURFACE TROUGH PRESSURE GRADIENT HAS INCREASED AND IS
PRODUCING STRONG SOUTHWEST WINDS IN GAP AREAS AROUND LIVINGSTON
AND NYE. MOS GUIDANCE NOT HANDLING THIS WELL AS HAS BEEN THE CASE
LATELY...BUT HRRR MODEL SOUNDINGS DEFINEATELY SHOW STRONG WINDS
WITHIN BOUNDARY LAYER. NEXT SHIFT MAY NEED TO ISSUE ADVISORY...BUT
LIVINGSTON WINDS CURRENTLY REMAINING SAFELY BELOW OUR ADVISORY
CRITERIA. THE WINDS HAVE CREATED SOME BLOWING SNOW AGAIN...BUT
SEEMS LIMITED TO BETWEEN 1 AND 3 MILES AND NOT AS BAD AS LAST
THURSDAY NIGHT...PROBABLY DUE TO SOME ABOVE FREEZING TEMPS THIS
WEEKEND. AT ANY RATE...HAVE INCREASED WINDS AND INCLUDED BLOWING
SNOW IN FORECAST FOR THESE AREAS OVERNIGHT. ISSUED WIND ADVISORY
THROUGH JUST 9 AM BASED ON LULL TOMORROW IN NAM DATA...BUT
SUSPECT WE COULD SEE THESE WINDS AGAIN TOMORROW NIGHT. BT

.SHORT TERM...VALID FOR MON AND TUE...

THE TRAIN OF SHORTWAVES CONTINUES THROUGH THE SHORT TERM...WITH
FLOW REMAINING PROGRESSIVE THROUGH THE PERIOD. GIVEN THIS
PROGRESSIVE PATTERN...THESE SYSTEMS WILL FOR THE MOST PART BE
LACKING IN DYNAMIC...THUS NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS.

THE FIRST WAVE MOVES THROUGH OVERNIGHT...HOWEVER THE BULK OF THE
ENERGY MOVES NORTH OF THE AREA RESULTING IN MUCH OF THE AREA
REMAINING DRY. THERE IS STILL SOME INSTABILITY...MAINLY AROUND
THE SOUTHWESTERN MOUNTAINS AND FOOTHILLS...SO A LITTLE BIT OF
ACCUMULATING SNOWFALL CAN BE EXPECTED IN THE HIGHER TERRAIN. FOR
THE REMAINDER OF THE AREA...THERE COULD BE SOME PATCHY FOG BUT AT
THIS POINT GIVEN WINDS WILL BE STRONGER HAVE NOT MENTIONED
ANYTHING IN THE GRIDS.

MONDAY NIGHT THE NEXT WAVE WILL MOVE THROUGH AND BRING A SLIGHTLY
BETTER CHANCE FOR SNOWFALL. THE ENERGY WITH THIS SYSTEM WILL PUSH
FARTHER SOUTH...WHICH WILL SPREAD THE SNOW CHANCES OUT ON TO THE
PLAINS. THE INSTABILITY WILL BE BETTER WITH THIS SYSTEM...SO COULD
SEE SOME BETTER ACCUMULATIONS...BUT WILL STILL REMAIN UNDER ANY
CRITERIA.

TEMPERATURES WILL REMAIN FAIRLY SEASONAL THROUGH THE PERIOD.
REIMER

.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...

EXTENDED MODELS WERE IN OVERALL AGREEMENT THROUGH THE PERIOD IN
SHOWING WESTERLY FLOW WITH MULTIPLE SHORTWAVES... AS PER EURO AND
GFS GUIDANCE. PRECIP CHANCES LOOK TO BE MOSTLY LIMITED TO WESTERN
TERRAIN ON WED AND THUR WITH SLIGHT CHANGES IN THE EASTERN PLAINS
ON WED. MODELS CONTINUE TO BRING A DEEPER TROUGH INTO THE REGION
ON FRI... BRINGING THE MOST WIDESPREAD CHANCES OF SLIGHT POPS
BETWEEN THE MORNING AND AFTERNOON HOURS OF XMAS DAY. PRECIP
CHANCES WILL THEN DIMINISH IN SE MT AS THE POSITIVELY TILTED
TROUGH EXITS LATER THAT DAY. UPPER-LEVEL FLOW LOOKS TO THEN RETURN
TO RIDGING BEHIND THIS TROUGH... WITH A MUCH DRIER PATTERN ACROSS
THE CWA.

SFC PRESSURE GRADIENT SETS UP QUITE STRONGLY OVER THE WESTERN
FOOTHILLS OVERNIGHT SAT AND CONTINUES THRU SUN WITH SOME
DIFFERENCES BETWEEN THE MODELS ON HOW THE GRADIENT SETS UP. BASED
ON THE CONTINUED GRADIENT STRENGTH...HAVE RETAINED GAP FLOW WINDS
WITHIN THE ADVISORY/WARNING CRITERIA DURING THIS TIME FRAME. WILL
DEFINITELY NEED TO WATCH MODEL TRENDS TO SEE IF THIS PATTERN
CONTINUES TO PERSIST FROM RUN-TO-RUN.

NEAR-NORMAL TEMPERATURES WILL CONTINUE EARLY IN THE PERIOD. THUR
AND FRI WILL BE THE COLDEST DAYS WITH MAXT VALUES IN THE MID TO
LOW 20S...THEN TEMPERATURES WILL MODERATE THROUGH THE WEEKEND...
PERHAPS INTO THE MID 30S ON SUN. MROWELL

.AVIATION...

SOME AREAS OF FOG EXPECTED TONIGHT ACROSS SOUTHERN MONTANA AND
NORTH-CENTRAL WYOMING. A FEW SNOW SHOWERS ARE POSSIBLE WEST OF
KBIL OVERNIGHT AND MON AFTERNOON-EVENING. CONDITIONS CAN DROP TO
MVFR/IFR IN SNOW SHOWERS AND VLIFR IN FOG. OTHERWISE...CONDITIONS
WILL BE VFR. MOUNTAIN OBSCURATIONS LIKELY TONIGHT AND MONDAY.
LLWS IS POSSIBLE NEAR KBIL...KMLS AND KSHR TONIGHT INTO MON
MORNING. RMS/BT

.PRELIMINARY POINT TEMP/POPS...

MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 021/034 023/035 018/029 013/024 008/020 007/024 015/036
11/B 23/J 22/J 11/E 12/J 11/N 11/N
LVM 021/033 024/034 018/027 014/025 008/020 006/020 012/032
33/S 45/J 42/J 22/J 22/J 21/N 11/N
HDN 017/037 019/037 012/032 007/026 002/020 001/024 002/035
11/B 23/J 22/J 11/E 12/J 21/U 11/B
MLS 021/036 017/033 013/029 012/023 004/019 003/023 009/035
11/B 13/J 22/J 11/E 12/J 11/U 11/B
4BQ 020/036 018/036 014/029 009/026 007/022 002/023 010/035
01/B 12/J 22/J 11/E 12/J 21/B 11/B
BHK 020/035 017/033 014/029 013/025 005/020 005/023 009/036
11/B 03/J 31/B 11/B 11/E 21/B 11/B
SHR 017/036 018/036 013/028 006/026 003/022 000/023 008/037
12/S 23/J 22/J 11/B 12/J 21/U 11/B

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WIND ADVISORY IN EFFECT UNTIL 8 AM MST MONDAY FOR ZONES
65-66.
WY...NONE.

$$
WEATHER.GOV/BILLINGS

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

1145 AM CST MON DEC 21 2015

.SYNOPSIS...
ISSUED AT 340 AM CST MON DEC 21 2015

H5 ANALYSIS FROM EARLIER THIS EVENING HAD A LOW AMPLITUDE PATTERN
ACROSS THE CONUS. ZONAL FLOW WAS PRESENT FROM THE WEST COAST...EWD
TO THE MISSISSIPPI RIVER. EAST OF THE RIVER...LOW AMPLITUDE
RIDGING WAS PRESENT FROM SOUTH CAROLINA...NWD INTO SRN QUEBEC.
ACROSS THE CENTRAL AND SRN PLAINS...A DECENT SHORTWAVE TROUGH WAS
NOTED OVER SERN COLORADO. CURRENTLY...THIS FEATURE WAS LOCATED
OVER CENTRAL KS. AT THE SURFACE...A COLD FRONT HAS PASSED WELL
SOUTH OF THE FORECAST AREA THIS EVENING AND WAS ORIENTED ALONG A
LINE FROM DES MOINES IOWA...TO ST JOSEPH MISSOURI...TO WICHITA
KANSAS. ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...A VEIL OF LOW
CLOUDINESS HAS SET IN ACROSS THE FORECAST AREA WITH CIGS GENERALLY
BETWEEN 500 TO 1000 FT AGL OVERNIGHT. SOME FOG WAS PRESENT IN THE
NEBRASKA PANHANDLE...ALONG THE WESTERN FLANK OF THE INVADING
STRATUS. TEMPERATURES WERE FAIRLY MILD FOR MID DECEMBER AS 3 AM
CST READINGS WERE GENERALLY IN THE 20S.

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST MON DEC 21 2015

FOG POTENTIAL THIS MORNING...COUPLED WITH CLOUDINESS AND ITS
IMPACTS ON TEMPERATURES WILL BE THE MAIN FORECAST CHALLENGE. FOR
THIS MORNING WITH RESPECT TO FOG POTENTIAL...SUPPORT FOR AT LEAST
A PATCHY FOG MENTION CONTINUES INTO THE MID TO LATE MORNING
HOURS...ESPECIALLY OVER NORTH CENTRAL NEBRASKA PER THE LATEST
NAM12...SREF PROBABILITIES FCST...AS WELL AS THE HRRR SFC VISBY
FORECAST. ALBEIT...THE HRRR IS MOST AGGRESSIVE WITH THE
FOG...CONTINUING IT WELL INTO THE AFTERNOON HOURS ACROSS NORTHERN
AND NORTHEASTERN PORTIONS OF THE FORECAST AREA. THE HRRR DOES NOT
HAVE THE SUPPORT OF THE NAM12 AND SREF FOR EXTENDING FOG PAST
MIDDAY. THIS IS ALSO REFLECTED IN THE STATISTICAL GUIDANCE AS
WELL. THAT BEING SAID...WILL PLAN ON ENDING THE MENTION OF FOG
AFTER 16Z THIS MORNING. AS FOR TEMPERATURES TODAY...LOW LEVEL
CLOUDS SHOULD HANG ON WELL INTO THE AFTERNOON HOURS ACROSS
NORTHERN NEBRASKA PER NAM12 AND SREF H850-H900 LAYER RH
FORECASTS...AND THIS WILL HAVE A HUGE IMPACT ON HIGHS IN THE NORTH
TODAY. FOR THE SRN HALF OF THE FORECAST AREA...LOW CLOUDS SHOULD
BURN OFF BY MIDDAY...ALLOWING TEMPS TO REACH INTO THE 40S. FOR
TONIGHT...A SURFACE TROUGH WILL DEEPEN ACROSS EASTERN WYOMING WITH
A TIGHTENING SURFACE PRESSURE GRADIENT DEVELOPING OVERNIGHT. H925
AND H85 WINDS SUPPORT SOME MIXING AFTER MIDNIGHT...AND GUIDANCE
ACTUALLY SUPPORTS TEMPS WARMING IN THE WEST AND NORTHERN CWA
OVERNIGHT WITH LOWS OCCURRING DURING THE EVENING HRS. WITH THE
EXCEPTION OF THE PLATTE RIVER VALLEY WHERE UPPER TEENS ARE
EXPECTED...LOWS WILL GENERALLY BE IN THE MIDDLE 20S AND SHOULD BE
ACHIEVED DURING THE LATE EVENING TO THE EARLY OVERNIGHT HRS.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM CST MON DEC 21 2015

A COUPLE OF FAST MOVING SHORTWAVE DISTURBANCES WILL CROSS THE AREA
TUESDAY AND WEDNESDAY. AN INCREASE IN MID AND HIGH LEVEL
CLOUDINESS CAN BE EXPECTED DURING THIS TIME. DID ADD A SLIGHT
CHANCE FOR SNOW SHOWERS WEDNESDAY NIGHT. APPEARS TO BE ENOUGH
LIFT AND SATURATION PRESENT TO WARRANT A SLIGHT CHANCE DURING
THIS TIME. OTHERWISE A MILD PACIFIC AIRMASS IN PLACE WITH A
WESTERLY DOWNSLOPE CHINOOK TYPE LOW LEVEL FLOW. DESPITE DOWNSLOPE
FLOW...DID LIMIT DAYTIME HIGHS A BIT TO UPPER 30S AND 40S DUE TO
EXPECTED MID AND HIGH CLOUDS AND LINGERING SNOW COVER IN SPOTS.

MODELS HAVE COME INTO BETTER AGREEMENT TONIGHT FOR THE CHRISTMAS
EVE THROUGH SATURDAY PERIOD. GEM/GFS/ECMWF AND MOST GFS ENSEMBLE
MEMBERS INDICATE THAT A SIGNIFICANT SHORTWAVE WILL DIVE SOUTHEAST
FROM THE GULF OF ALASKA INTO THE DESERT SOUTHWEST BY CHRISTMAS
MORNING. ALL THREE OPERATIONAL MODELS CLOSE THE SYSTEM OFF AND
SLOWLY MOVE IT EASTWARD TOWARD WEST TX BY SUNDAY NIGHT. BROAD
SOUTHWEST FLOW ALOFT WITH EMBEDDED 140 KT JET STREAK WILL
OVERSPREAD THE CENTRAL AND SOUTHERN PLAINS CHRISTMAS DAY THROUGH
SATURDAY NIGHT AHEAD OF THE SYSTEM. LIFT ASSOCIATED WITH THE JET
CIRCULATION AND DECENT LOW/MID LEVEL MOISTURE ADVECTION INTO THE
AREA SHOULD YIELD A PERIOD OF SNOW CHRISTMAS NIGHT THROUGH
SATURDAY. WILL CONTINUE THE CAUTIOUS...CONSERVATIVE APPROACH
REGARDING SNOW CHANCES THIS FORECAST CYCLE...BUT...IF MODELS
CONTINUE TO SHOW TONIGHTS IMPROVED AGREEMENT...CHANCES WILL HAVE
TO BE INCREASED. IN ADDITION...A STRONG COLD FRONT WILL CROSS THE
AREA DURING THE DAY SATURDAY. NORTH WINDS WILL INCREASE BEHIND THE
FRONT...WHICH COULD LEAD TO SOME BLOWING SNOW IF ENOUGH
ACCUMULATES.

BY SUNDAY...THE JET DYNAMICS AND ASSOCIATED LIFT WILL
WEAKEN...AND WITH THE CLOSED UPPER LOW EXPECTED TO BE WELL TO OUR
SOUTH...WILL LEAVE THE FORECAST DRY.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1145 AM CST MON DEC 21 2015

THERE IS A CONFLICTING MESSAGE IN THE NEAR TERM SOLUTIONS
CONCERNING THE RETURN OF STRATUS AND/OR FOG AT BOTH KLBF AND KVTN
THIS EVENING AND OVERNIGHT. FOR THIS...FORECAST CONFIDENCE IS
RATHER WEAK. WE DO ANTICIPATE THAT SOUTHWEST TO WESTERLY WINDS
WILL INCREASE OVERNIGHT ACROSS THE PANHANDLE AND CENTRAL SANDHILLS
AS THE SFC PRESSURE GRADIENT INCREASES. THIS WOULD FAVOR STRATUS
RATHER THAN FOG. WILL INCLUDE A SCT015 DECK AT BOTH KVTN AND
KLBF...AND UPDATE AS CONDITIONS WARRANT.

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...TAYLOR
AVIATION...JACOBS

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

555 AM CST MON DEC 21 2015

.SYNOPSIS...
ISSUED AT 340 AM CST MON DEC 21 2015

H5 ANALYSIS FROM EARLIER THIS EVENING HAD A LOW
AMPLITUDE PATTERN ACROSS THE CONUS. ZONAL FLOW WAS PRESENT FROM THE
WEST COAST...EWD TO THE MISSISSIPPI RIVER. EAST OF THE RIVER...LOW
AMPLITUDE RIDGING WAS PRESENT FROM SOUTH CAROLINA...NWD INTO SRN
QUEBEC. ACROSS THE CENTRAL AND SRN PLAINS...A DECENT SHORTWAVE
TROUGH WAS NOTED OVER SERN COLORADO. CURRENTLY...THIS FEATURE WAS
LOCATED OVER CENTRAL KS. AT THE SURFACE...A COLD FRONT HAS PASSED
WELL SOUTH OF THE FORECAST AREA THIS EVENING AND WAS ORIENTED ALONG
A LINE FROM DES MOINES IOWA...TO ST JOSEPH MISSOURI...TO WICHITA
KANSAS. ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...A VEIL OF LOW
CLOUDINESS HAS SET IN ACROSS THE FORECAST AREA WITH CIGS GENERALLY
BETWEEN 500 TO 1000 FT AGL OVERNIGHT. SOME FOG WAS PRESENT IN THE
NEBRASKA PANHANDLE...ALONG THE WESTERN FLANK OF THE INVADING
STRATUS. TEMPERATURES WERE FAIRLY MILD FOR MID DECEMBER AS 3 AM CST
READINGS WERE GENERALLY IN THE 20S.

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST MON DEC 21 2015

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM CST MON DEC 21 2015

BY SUNDAY...THE JET DYNAMICS AND ASSOCIATED LIFT WILL
WEAKEN...AND WITH THE CLOSED UPPER LOW EXPECTED TO BE WELL TO OUR
SOUTH...WILL LEAVE THE FORECAST DRY.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 554 AM CST MON DEC 21 2015

FOR THE KLBF TERMINAL...EXPECT CIGS BELOW 1000 FT AGL THIS
MORNING..RISING TO 1500 FT AGL BY 17Z. CIGS WILL SCATTER OUT BY
MID AFTERNOON WITH CIGS OF 12000 TO 20000 FT AGL THROUGH 12Z
TUESDAY. FOR THE KVTN TERMINAL...EXPECT CIGS BELOW 1000 FT AGL
THROUGH 18Z...INCREASING TO 1200 FT AGL FOR MOST OF THE AFTERNOON
HOURS. CIGS WILL SCATTER OUT BY SUNSET WITH CIGS RANGING FROM
10000 TO 20000 FT AGL TONIGHT.

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...TAYLOR
AVIATION...BUTTLER

AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

342 AM CST MON DEC 21 2015

.SYNOPSIS...
ISSUED AT 340 AM CST MON DEC 21 2015

H5 ANALYSIS FROM EARLIER THIS EVENING HAD A LOW
AMPLITUDE PATTERN ACROSS THE CONUS. ZONAL FLOW WAS PRESENT FROM THE
WEST COAST...EWD TO THE MISSISSIPPI RIVER. EAST OF THE RIVER...LOW
AMPLITUDE RIDGING WAS PRESENT FROM SOUTH CAROLINA...NWD INTO SRN
QUEBEC. ACROSS THE CENTRAL AND SRN PLAINS...A DECENT SHORTWAVE
TROUGH WAS NOTED OVER SERN COLORADO. CURRENTLY...THIS FEATURE WAS
LOCATED OVER CENTRAL KS. AT THE SURFACE...A COLD FRONT HAS PASSED
WELL SOUTH OF THE FORECAST AREA THIS EVENING AND WAS ORIENTED ALONG
A LINE FROM DES MOINES IOWA...TO ST JOSEPH MISSOURI...TO WICHITA
KANSAS. ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...A VEIL OF LOW
CLOUDINESS HAS SET IN ACROSS THE FORECAST AREA WITH CIGS GENERALLY
BETWEEN 500 TO 1000 FT AGL OVERNIGHT. SOME FOG WAS PRESENT IN THE
NEBRASKA PANHANDLE...ALONG THE WESTERN FLANK OF THE INVADING
STRATUS. TEMPERATURES WERE FAIRLY MILD FOR MID DECEMBER AS 3 AM CST
READINGS WERE GENERALLY IN THE 20S.

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST MON DEC 21 2015

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM CST MON DEC 21 2015

BY SUNDAY...THE JET DYNAMICS AND ASSOCIATED LIFT WILL
WEAKEN...AND WITH THE CLOSED UPPER LOW EXPECTED TO BE WELL TO OUR
SOUTH...WILL LEAVE THE FORECAST DRY.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1133 PM CST SUN DEC 20 2015

IFR CEILINGS TO PERSIST AT KVTN OVERNIGHT UNTIL 16Z MONDAY. IN
ADDITION PATCHY FOG POSSIBLE WITH 3SM BR FCST UNTIL 10Z. AFTER
16Z...STRATUS SHOULD SCATTER OUT WITH VFR CONDITIONS. AT
KLBF...IFR CONDITIONS SHOULD PERSIST UNTIL 15Z...ALSO SCATTERING
OUT AND BECOMING VFR.

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...TAYLOR
AVIATION...ROBERG

AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

1238 PM EST MON DEC 21 2015

.SYNOPSIS...
IT WILL BE CLOUDY TODAY WITH SPOTTY LIGHT RAIN SHOWERS THIS
AFTERNOON TO EVENING. HOWEVER...A MORE SOLID BATCH OF RAIN WILL
MOVE THROUGH THE REGION TUESDAY MORNING. THOUGH IT WILL REMAIN
UNSETTLED WEDNESDAY AND THURSDAY WITH OCCASIONAL
SHOWERS...TEMPERATURES WILL ALSO TREND WARMER. RECORD HIGHS ARE
POSSIBLE CHRISTMAS EVE DAY.

.NEAR TERM /THROUGH TONIGHT/...
UPDATED AT NOON... CURRENT FORECAST IS ON TRACK. RADAR IS SHOWING
SOME LIGHT RETURNS OVER OUR NORTHERN AND WESTERN COUNTIES BUT
LATEST OBSERVATIONS INDICATE THAT MOST OF THIS IS NOT REACHING THE
GROUND. LATEST HRRR SHOWS SOME LIGHT ECHOES ASSOCIATED WITH A WEAK
MID-LEVEL WAVE WEAKENING AS THEY MOVE EAST ACROSS CENTRAL NY LATER
THIS AFTERNOON. THE LATEST SREF ALSO INDICATE THAT POPS REMAIN
RATHER LOW THIS AFTERNOON... ESPECIALLY FOR LOCATIONS ALONG AND
EAST OF I-81 AND SOUTH OF SYRACUSE. OUR CURRENT FORECAST MATCHES
THESE TRENDS QUITE WELL AND HAVE NOT CHANGED POPS WITH THIS
UPDATE. MAIN CHANGE WAS TO NUDGE TEMPERATURES UP A FEW DEGREES
OVER THE LAKE PLANE WHERE READINGS ARE ALREADY APPROACHING 50 IN
MANY LOCATIONS. FARTHER SOUTH AND EAST TEMPERATURES ARE A BIT
COOLER AND SHOULD HOLD IN THE MID TO UPPER 40S. PREVIOUS
DISCUSSION IS BELOW.

635 AM UPDATE...
TEMPERATURES WERE ALREADY FORECAST TO CREEP UP THE LAST SEVERAL
HOURS...BUT THAT IS OCCURRING EVEN FASTER THAN HAD BEEN
FIGURED...ESPECIALLY IN THE FINGER LAKES AREA. I TWEAKED
TEMPERATURE GRIDS TO KEEP UP WITH OBS AND ALSO QUICKENED THE
PROGRESSION FROM MOSTLY CLOUDY TO PLAIN CLOUDY FOR MOST OF THE
DAY...REST OF FORECAST ON TRACK.

PREVIOUS DISCUSSION...
WE HAVE JUST BEGUN WHAT WILL BE AN EXTENDED PERIOD OF MILD AND
MOIST SOUTHWEST FLOW ALOFT...ONE RIDDLED WITH MULTIPLE EMBEDDED
WAVES AND RESULTANT CHANCES FOR SHOWERS.

AT 145 AM...MOISTURE IS NOW STREAMING IN ALOFT AS PER THE WATER
VAPOR IMAGERY EARLY THIS MORNING. FOR MOST LOCATIONS...LOW
TEMPERATURES FOR THE NIGHT ALREADY OCCURRED WHEN WE HAD INITIALLY
CLEAR SKY EARLY SUNDAY EVENING AND THUS SOME RADIATIONAL COOLING.
NOT THE CASE NOW...WITH HIGH THIN CLOUDS ALOFT...AND WARM AIR
ADVECTION UNDERWAY. TEMPERATURES WILL HOLD NEARLY STEADY OR CREEP
UP THE REMAINDER OF THE OVERNIGHT HOURS. THIS WILL MAKE HEADWAY
TOWARDS HIGHS IN THE LOWER TO MID 40S FOR TODAY...ABOUT 10 DEGREES
ABOVE CLIMATOLOGY. THAT IS ONLY THE BEGINNING COMPARED TO COMING
DAYS.

IN THE VERY QUICK FLOW ALOFT...A WEAK WAVE NOW NEAR KANSAS CITY
WILL ZIP NORTHEAST THROUGH OUR REGION ALREADY THIS AFTERNOON INTO
EVENING...HOWEVER...IT WILL HAVE TO COMBAT A LOT OF DRY AIR IN THE
LOWER LEVELS. THE BARK OF RADAR COVERAGE WILL LIKELY BE WORSE THAN
THE BITE...SINCE MUCH OF THE SHOWER ACTIVITY WILL COME IN THE FORM
OF VIRGA...DRYING UP BEFORE HITTING THE GROUND. WITH SOUTHERLY
WIND UPSLOPING INTO NORTHERN ONEIDA COUNTY...SHOWER CHANCES ARE
BETTER THERE...BUT MAJORITY OF OUR AREA WILL ONLY SEE RAIN AMOUNTS
ON THE ORDER OF HUNDREDTHS OF AN INCH. INDEED SOME IN NORTHEAST PA
TO FINGER LAKES NY COULD END UP WITH NOTHING AT ALL OTHER THAN
CLOUDS WITH THIS FIRST WAVE...HOWEVER...BETTER RAIN CHANCES ARE
QUICKLY EN ROUTE.

THOUGH MOST OF TONIGHT WILL BE QUIET...THE LEADING EDGE OF A
SECOND STRONGER WAVE WILL START TO SPREAD THIS BATCH OF RAIN INTO
THE AREA AROUND OR JUST BEFORE DAWN. AHEAD OF THAT SECOND
WAVE...CLOUDS...WARM AIR ADVECTION...AND SOUTH- SOUTHWESTERLY
BOUNDARY LAYER WIND WILL CONTINUE TONIGHT...SO TEMPERATURES WILL
BARELY MOVE WITH LOWS IN UPPER 30S- LOWER 40S.

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
415 AM UPDATE...
WE CONTINUE WITH MOIST SOUTHWEST FLOW...WITH WARMING TEMPERATURES
AND BATCHES OF RAIN PASSING TUESDAY MORNING AND WEDNESDAY
AFTERNOON-EVENING.

A STRONG WAVE IS CURRENTLY CROSSING THE ROCKIES. YESTERDAY
MORNING IT WAS JUST ARRIVING AT THE WEST COAST AFTER TRAVERSING
OVER THE DATA-SPARSE PACIFIC. ONE OF THE CHALLENGES OF A VERY
BRISK FLOW ALOFT...IS MODELS GETTING AN ADEQUATE HANDLE OF QUICKLY
MOVING WAVES WELL UPSTREAM. AS EARLY AS ABOUT 24 HOURS
AGO...MODELS WERE HINTING AT THIS WAVE CAUSING SOME POTENTIAL FOR
RAIN...AND NOW WITH THE LATEST RUNS THEY HAVE REALLY GRABBED ONTO
IT AND HAVE EVEN QUICKENED ITS PACE BY A FEW HOURS. THE UPPER WAVE
WILL CATCH UP WITH A SURFACE LOW PRESSURE PASSING THROUGH THE
GREAT LAKES...WHILE GAINING SUPPORT FROM THE RIGHT ENTRANCE REGION
OF A STRONG JET MAX ALOFT.

IN COORDINATION WITH SURROUNDING OFFICES...RAIN CHANCES HAVE BEEN
BUMPED INTO 70-80 PERCENT RANGE FOR SEVERAL HOURS TUESDAY MORNING.
AREAL AVERAGE RAINFALL OF TWO TO FOUR TENTHS OF AN INCH AT THIS
POINT IS EXPECTED...BUT IT IS POSSIBLE THAT MESOSCALE ENHANCEMENT
COULD OCCUR SOMEWHERE WITHIN THE AREA /FORCED ASCENT VIA JET
SUPPORT OR OTHER METHODS/ TO PUSH LOCALIZED AMOUNTS PAST A HALF
INCH. STEADY MORNING RAIN WILL TRANSITION TO SPOTTY LINGERING
SHOWERS IN AFTERNOON. DESPITE ALL THE RAIN...STILL EXPECTING TO
MANAGE MID 40S TO NEAR 50 FOR HIGHS.

MODEL CONSENSUS HAS THE NEXT WAVE IN THE PARADE ARRIVING MIDDAY
WEDNESDAY THROUGH AFTERNOON-EVENING. RAIN AGAIN LOOKS LIKELY
THEN...FOR THE WHOLE AREA GENERALLY BUT ESPECIALLY FROM WYOMING
VALLEY-POCONOS IN PA THROUGH CATSKILLS-UPPER SUSQUEHANNA REGION IN
NY. TEMPERATURES WILL ALSO GO UP ANOTHER 4-8 DEGREES...WIDESPREAD
50S FOR HIGHS...FOLLOWED BY LOWS THAT MAY ACHIEVE RECORD HIGH
MINIMUMS WEDNESDAY NIGHT /UPPER 40S-LOWER 50S/.

.LONG TERM /THURSDAY THROUGH SUNDAY/...
0240 AM UPDATE...NO MAJOR CHANGES TO LONG RANGE FORECAST. ONLY
MODIFICATION WAS TO BUMP HIGHS UP A COUPLE DEGREES FOR CHRISTMAS
EVE DAY. HIGHS THIS DAY LOOK TO BE IN THE LOWER TO MID 60S ACROSS
THE AREA...POTENTIALLY BREAKING RECORDS. FOR FURTHER DETAILS, SEE
DISCUSSION BELOW.

300 PM SUNDAY UPDATE...

WITH HIGH PRESSURE OFF THE SOUTHEAST COAST, AND A TROF IN THE
SOUTHWEST US, A DEEP SOUTHWEST FLOW WILL CONTINUE THROUGH THE
PERIOD. THE RESULT WILL REMAIN UNSETTLED WEATHER WITH CHANCES FOR
RAIN SHOWERS BUT ALSO MILD WEATHER, WITH RECORD WARMTH POSSIBLE
BY CHRISTMAS EVE DAY.

AFTER A LULL TUESDAY NIGHT, A NEW DISTURBANCE WILL MOVE INTO THE
AREA BY WEDNESDAY WITH MORE SHOWERS POSSIBLE. BY THIS TIME
HOWEVER A MUCH DEEPER TROF WILL DIG OVER THE UPPER MIDWEST, WHICH
WILL KEEP CHANCES FOR RAIN HIGH WEDNESDAY INTO THE FIRST PART OF
THURSDAY. DESPITE THE CLOUDS AND RAIN CHANCES WITH 850 TEMPS IN
THE +10C TO +12C RANGE BOTH DAYS, HIGHS WILL BE IN THE 50S AND
60S. RIGHT NOW CHRISTMAS EVE DAY LOOKS LIKE OUR BEST SHOT AT
BREAKING RECORDS, WITH FORECAST HIGHS IN THE 60S FOR MOST OF THE
AREA.

AS THE UPPER LEVEL TROF MENTIONED ABOVE LIFTS NORTH BY FRIDAY,
HIGH PRESSURE WILL BRING DRIER AND NOT QUITE AS MILD WEATHER TO
THE AREA FRIDAY AND SATURDAY. STILL WITH A PACIFIC ORIGIN,HIGHS
BOTH DAYS WILL STILL BE WELL ABOVE AVERAGE OR WELL INTO THE 40S!

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
1230 PM UPDATE...

VFR THROUGH LATE THIS AFTERNOON WITH A FEW SPRINKLES FROM TIME TO
TIME NY TERMINALS, AS CIGS LOWER FROM AROUND 10,000 FEET TO UNDER
5,000 FEET. BY TONIGHT AS WE CONTINUE TO MOISTEN UP, MVFR CIGS
WILL BECOME POSSIBLE AFTER 0Z AT MOST OF THE TERMINALS WITH THE
EXCEPTION OF KSYR AND KRME. AT KSYR AND KRME WHILE IT WILL BE
CLOSE, THE SOUTHERLY COMPONENT OF THE WIND MAY KEEP CIGS JUST
ABOVE MVFR, BARELY.

RAIN WILL OVERSPREAD THE TERMINALS BETWEEN 09Z AND 12Z SOUTHERN
TERMINALS, AND BY 14Z UP NORTH, TUESDAY. AS THIS HAPPENS CIGS WILL
LOWER A BIT MORE, WITH WIDESPREAD MVFR CIGS AND VSBYS EXPECTED. AT
THE HILLTOP TERMINALS OF KITH AND KBGM, IFR CIGS AND VSBYS
POSSIBLE IN RAIN AND MIST.

.OUTLOOK...

WED-THUR...RESTRICTIONS LIKELY AT TIMES AS A SERIES OF WAVES MOVE
THROUGH BRINGING PERIODS OF RAIN AND SHOWERS.

FRI...VFR.

SAT...RESTRICTIONS POSSIBLE IN RAIN.

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

$$
SYNOPSIS...MDP
NEAR TERM...MDP/MSE
SHORT TERM...MDP
LONG TERM...HEDEN/PCF
AVIATION...HEDEN

AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

1216 PM EST MON DEC 21 2015

PREVIOUS DISCUSSION...
WE HAVE JUST BEGUN WHAT WILL BE AN EXTENDED PERIOD OF MILD AND
MOIST SOUTHWEST FLOW ALOFT...ONE RIDDLED WITH MULTIPLE EMBEDDED
WAVES AND RESULTANT CHANCES FOR SHOWERS.

300 PM SUNDAY UPDATE...

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
630 AM UPDATE...

HIGH CLOUDS OVER THE AREA WILL LOWER TO A DECK AROUND 4-5 KFT BY
LATER TODAY AS AN INITIAL WAVE MOVES THROUGH. EXPECT CONDITIONS TO
REMAIN VFR HOWEVER. THIS FIRST WAVE MAY PRODUCE A FEW SHOWERS OVER
CENTRAL NY TERMINALS THOUGH CONFIDENCE NOT HIGH ENOUGH TO WARRANT INCLUSION
IN TAFS. A STRONGER WAVE APPROACHES LATE TONIGHT WITH CIGS
LOWERING TO MVFR FOR ALL SITES EXCEPT KSYR. RAIN MOVES INTO THE
THREE SOUTHERN TERMINALS BEFORE 12Z AND REMAINING TERMINALS AFTER
12Z TUESDAY MORNING.

WINDS WILL BE S/SE BECOMING MORE S/SW BY THIS AFTERNOON AND
GENERALLY BE AT SPEEDS OF AROUND 8-13 KNOTS WITH HIGHER GUSTS AT
TIMES UP TO 20 KNOTS FOR KITH/KBGM.

.OUTLOOK...

TUE-THUR...RESTRICTIONS LIKELY AT TIMES AS A SERIES OF WAVES MOVE
THROUGH BRINGING PERIODS OF RAIN AND SHOWERS.

FRI...VFR.

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

$$
SYNOPSIS...MDP
NEAR TERM...MDP/MSE
SHORT TERM...MDP
LONG TERM...HEDEN/PCF
AVIATION...PCF/TAC

AREA FORECAST DISCUSSION

NWS RALEIGH NC

806 PM EST TUE DEC 22 2015

.SYNOPSIS...A WEDGE FRONT WILL REMAIN QUASI-STATIONARY OVER THE
PIEDMONT THROUGH TONIGHT...THEN BE OVERTAKEN BY A MARITIME WARM
FRONT THAT WILL SURGE ACROSS THE CAROLINAS AND VIRGINIA ON
WEDNESDAY. ANOMALOUSLY STRONG SUB-TROPICAL HIGH PRESSURE OVER THE
WEST-CENTRAL ATLANTIC OCEAN WILL THEN DIRECT UNSEASONABLY WARM AND
MOIST SOUTHERLY FLOW THROUGHOUT THE SOUTHEASTERN UNITED STATES
THROUGH CHRISTMAS.

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM TUESDAY...

...HEAVY RAIN AND SOME LOCALIZED FLOODING POSSIBLE OVER THE WESTERN
PIEDMONT LATE TONIGHT INTO WEDNESDAY...

EARLIER RAINFALL IS NOW NEAR THE COAST AS THE ASSOCIATED SHEAR AXIS
AND DEEPEST MOISTURE HAVE SHIFTED EAST. SLIGHTLY DRIER MID LEVEL
AIR...WHICH HAS AIDED PERIODS OF DENSE FOG IN THE WEDGE AIRMASS
OVER THE WESTERN PIEDMONT...WILL GIVE WAY TO ANOTHER SURGE OF DEEP
MOISTURE ACCOMPANYING ANOTHER WAVE IN THE SOUTHWEST FLOW. PW WILL
INCREASE BACK TO NEAR 1.8 INCHES...WHICH IS NEARLY A CLIMATOLOGICAL
MAX FOR THIS TIME OF YEAR. WHILE THE MAIN AMPLIFICATION OF THE UPPER
TROUGH MOVING OUT OF THE SOUTHERN US WILL BE WELL WEST OF HERE... A
NOTABLE SHORTWAVE CURRENTLY OVER THE LOWER MISSISSIPPI VALLEY IS
FORECAST TOP LIFT ALONG THE SPINE OF THE APPALACHIANS AND SERVE AS A
FOCUS FOR HEAVY RAINFALL. THE WESTERN PIEDMONT LIES ON THE EAST
EDGE OF THE GENERAL MODEL CONSENSUS OF 2+ INCHES OF QPF...BUT GIVEN
THE ANOMALIES IN THIS PATTERN AND THE 1-2 INCHES THAT FEEL LAST
NIGHT...A FLASH FLOOD WATCH WILL BE ISSUED STARTING AT MIDNIGHT
TONIGHT FOR THE WESTERN PIEDMONT. PRIOR TO THE RAIN...THE HRRR SHOWS
WIDESPREAD FOG SETTLING BACK IN WITHIN THE WEDGE AIRMASS. A DENSE
FOG ADVISORY MAY BE NEEDED BEFORE PRECIP SPREADS IN FROM THE SOUTH
AND HELPS TO AT LEAST MIX OUT THE 1/4 MILE VSBYS. TEMPS WILL HOLD
STEADY OR RISE LATE TONIGHT WITH THE STRENGTHENING WARM
ADVECTION..WITH READINGS IN THE UPPER 50S TO UPPER 60S.

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM TUESDAY...

ONGOING PRECIP WEDNESDAY MORNING WILL BE FOCUSED ACROSS THE WESTERN
PIEDMONT AS A DISTURBANCE LIFTS ALONG THE APPALACHIANS. INCREDIBLY
HIGH PW DISCUSSED INT HE NEAR TERM FORECAST WILL REMAIN OVER THE
AREA WITH NO AIRMASS CHANGE IN SIGHT. THE FOCUS FOR PRECIP...LIKELY
MORE CONVECTIVE IN NATURE...SHOULD SHIFT EAST DURING THE DAY AS THE
DISTURBANCE LIFTS OFF TO THE NORTH AND A TRAILING SHEAR AXIS MOVES
EAST. MID-LEVEL LAPSE RATES ARE EXPECTED TO BE WEAK EAST OF THE
APPALACHIANS (THOUGH THE GFS FORECASTS 6+ C/KM)...BUT GIVEN TEMPS
CLIMBING INTO THE MID 70S AND DEWPOINTS APPROACHING 70...FORECAST
SOUNDINGS SHOW A RANGE OF 500-1000 J/KG OF MUCAPE IN THE COASTAL
PLAIN WEDNESDAY AFTERNOON. EVEN IF THIS IS A LITTLE
OVERDONE...CONVECTION SHOULD BE UNINHIBITED AND COULD TAP INTO THE
40-50KT DEEP SHEAR AND RESULT IN AT LEAST AN ISOLATED SEVERE THREAT.
CONFIDENCE IS LOW GIVEN THE TIME OF YEAR...BUT THE PATTERN IS
UNUSUALLY WARM AND MOIST. EVEN WITHOUT STRONG STORMS...CONVECTIVE
CELLS WILL BE CAPABLE OF PRODUCING ANOTHER INCH OR MORE OF RAIN IN
ISOLATED AREAS...SO A LOCALIZED FLASH FLOOD THREAT MAY STILL BE
THERE.

THE OVERALL COVERAGE OF PRECIP WILL LESSEN WEDNESDAY NIGHT...THOUGH
MODELS CONTINUE TO SHOW POTENTIAL FOR SOME SCATTERED SHOWERS WELL ON
THROUGH THE NIGHT. LOWS WILL BE VERY MILD IN THE MID AND UPPER 60S.

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 200 PM TUESDAY...

THU AND THU NIGHT: STILL SOME DIFFERENCES IN THE MODELS WITH RESPECT
TO RAIN...THUS THERE IS STILL SOME UNCERTAINTY. HOWEVER...IT IS
LOOKING LIKE THURSDAY COULD BE RELATIVELY DRY...BUT WILL KEEP A
CHANCE OF SOME RAIN IN THE FORECAST. RAIN SHOULD NOT BE NEARLY AS
WIDESPREAD AS IN PRECEDING DAYS. BEST CHANCES FOR CONVECTION WILL
BE IN THE NORTHWEST...ESPECIALLY IN THE AFT/EVE AND INTO THE
OVERNIGHT. HIGHEST TEMPERATURES OF THE LONG TERM ARE STILL EXPECTED
ON THURSDAY AS THE SOUTHERLY WARM ADVECTION PEAKS. HIGHS IN THE LOW
TO MID 70S NW TO AROUND 80 DEGREES IN THE SE. LOWS GENERALLY IN THE
MID 60S.

FRI THROUGH SUN: AS OF THE LATEST MEDIUM RANGE MODEL RUNS...THIS
PERIOD WILL LIKELY BE DOMINATED BY SUB-TROPICAL RIDGING ALOFT OVER
THE SOUTHEAST U.S.. SOUTHERLY TO SOUTHWESTERLY RETURN FLOW AROUND
THE SURFACE HIGH WILL CONTINUE TO USHER WARM MOIST AIR INTO THE
REGION...RESULTING IN A VERY WARM AND MOIST PERIOD FOR THIS TIME OF
YEAR. THE OCCASIONAL UPPER LEVEL DISTURBANCE RIDING THE RIDGE MAY
GENERATING ENOUGH LIFT IN THE ANOMALOUSLY WARM MOIST AIRMASS TO KICK
OFF SOME SHOWERS...MAINLY IN THE AFT/EVE HOURS. THE GENERAL PRECIP
TREND FOR THIS PERIOD WILL BE CHARACTERIZED BY A LULL DURING THE
OVERNIGHT AND MORNING HOURS AND HIGHEST CHANCES DURING THE AFT/EVE.
THE INITIAL FRONTAL SURGE THAT WAS ORIGINALLY EXPECTED TO PUSH SOUTH
INTO THE AREA ON FRIDAY WILL LIKELY STAY WELL TO THE NORTH THROUGH
AT LEAST SUNDAY EVENING. LOWS THROUGH THE PERIOD WILL BE FAIRLY
CONSISTENT...AND WELL ABOVE NORMAL...IN THE MID 50S TO LOW 60S.
HIGHS WILL LIKELY FLUCTUATE A BIT MORE...BUT GENERALLY STAY BETWEEN
THE MID 60S AND UPPER 70S...WHICH IS 10-15 DEGREES ABOVE NORMAL FOR
LATE DECEMBER.

MONDAY AND MONDAY NIGHT...THE GFS AND ECMWF VARY ON WHETHER THEY
THINK A SECONDARY SURGE WILL PUSH FAR ENOUGH SOUTH TO MOVE INTO
CENTRAL NC FOR THE BEGINNING OF THE WEEK. WILL HOLD OFF ON MAKING
ANY DRASTIC CHANGES TO THE PREVIOUS FORECAST FOR EARLY NEXT WEEK
UNTIL THERE IS BETTER AGREEMENT ONE WAY OR THE OTHER.

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 740 PM TUESDAY...

24 HOUR TAF PERIOD: ADVERSE AVIATION CONDITIONS ARE EXPECTED TO
CONTINUE FOR THE 24 HOUR TAF PERIOD... AS A WARM MOIST AIRMASS
REMAINS OVER CENTRAL NC.

SUB-VFR CIGS AND VISBYS ARE EXPECTED TO EXPAND/REDEVELOP TONIGHT
ACROSS ALL OF CENTRAL NC... WITH THE WORST CONDITIONS AT KGSO/KINT
(ALREADY LIFR). ANOTHER ROUND OF RAIN/SHOWERS... WITH PERHAPS A
FEW EMBEDDED STORMS... IS EXPECTED TO MOVE INTO THE AREA LATE
TONIGHT... FIRST ACROSS THE WESTERN TERMINALS... THEN SPREADING EAST
THROUGH THE MORNING INTO THE AFTERNOON WEDNESDAY.

CIGS/VISBYS AT KGSO/KINT ARE EXPECTED TO REMAIN IN THE LIFR CATEGORY
FOR MOST OF THE TAF PERIOD... WITH POSSIBLY SOME BRIEF IMPROVEMENT
ACTUALLY AS THE PRECIP MOVES INTO THE AREA LATE TONIGHT... THEN
AGAIN BY MID TO LATE AFTERNOON WEDNESDAY (THOUGH LIKELY ONLY
IMPROVING TO IFR). IN ADDITION TO THE POSSIBLE SUB-VFR CONDITIONS...
WE MAY SEE SOME MARGINAL LLWS CONDITIONS IN THE 10Z TO 16Z
WEDNESDAY KGSO/KINT... AS WINDS AT AROUND 2 KFT STRENGTHEN TO AROUND
30 TO 35 KTS. HOWEVER... WITH GENERALLY UNIDIRECTIONAL LOW
LEVEL FLOW AND SURFACE WINDS SPEEDS INCREASING DURING THAT TIME
AS WELL... WILL NOT INCLUDE ANY MENTION OF LLWS AT KGSO/KINT.

FURTHER EAST AT KRDU/KFAY/KRWI... WE SHOULD SEE IMPROVEMENT IN CIGS
AND VISBYS BY MID TO LATE MORNING INTO THE AFTERNOON... WITH
POSSIBLY SOME VFR CONDITIONS AT KRWI AND KFAY BY MID AFTERNOON.
HOWEVER... EXPECT WE WILL SEE SOME SCATTERED TO NUMEROUS SHOWERS...
WITH ISOLATED STORMS FROM MID MORNING THROUGH MID AFTERNOON... AND
INCREASING SOUTHERLY WINDS... WITH GUSTS OF UP TO 20 TO 25 KTS
POSSIBLE.

OUTLOOK: A MOIST DEEP SOUTHWESTERLY FLOW DOWNSTREAM OF THE LONG WAVE
TROUGH IN PLACE ACROSS THE CENTRAL CONUS WILL SUPPORT A PROLONGED
PERIOD OF ADVERSE AVIATION CONDITIONS THROUGH MUCH OF THE PERIOD.
SUB-VFR CONDITIONS IN LOW CLOUDS/STRATUS WILL ALSO BE LIKELY EACH
MORNING... ALONG WITH THE TREAT OF SOME SHOWERS EACH DAY.

.CLIMATE...

HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.

DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)

DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)

.RAH WATCHES/WARNINGS/ADVISORIES... NONE.

SYNOPSIS...2
NEAR TERM...22
SHORT TERM...22
LONG TERM...10
AVIATION...77/22
CLIMATE...HARTFIELD/BLAES

AREA FORECAST DISCUSSION

NWS RALEIGH NC

310 PM EST MON DEC 21 2015

.SYNOPSIS... A SOUTHERLY FLOW OF WARMER AND MORE MOIST AIR WILL
DEVELOP TODAY AND PERSIST FOR MUCH OF THE WEEK. MEANWHILE...A COLD
FRONT WILL APPROACH THE AREA FROM THE WEST ON TUESDAY...THEN STALL
OVER THE REGION.

.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 PM MONDAY...

WARM ADVECTION...AHEAD OF A COLD FRONT IN THE MISSISSIPPI VALLEY
REGION...CONTINUES ACROSS THE SOUTHEAST US IN DEEP SOUTHEASTERLY
FLOW. A LIGHT BAND OF RAIN ASSOCIATED WITH A NARROW REGION OF 700MB
MOISTURE JUST WEST OF THE TRIAD MAY PRODUCE SOME VERY LIGHT RAIN
THIS AFTERNOON...BUT THE LOW-LEVELS ARE STILL RATHER DRY AND ITS
TAKING SOME TIME FOR THE PRECIP TO REACH THE GROUND. THUS...A LARGE
MAJORITY OF THE CWA WILL BE DRY THIS EVENING. MODELS SHOW A LARGE
AREA OF RAIN BREAKING OUT OUT OVER GA/AL THIS EVENING AND SPREADING
NORTHEAST INTO THE CAROLINAS AFTER MIDNIGHT AS A SHORTWAVE PASSES TO
OUR NORTHWEST AND A LOW LEVEL JET INCREASES THE ISENTROPIC LIFT/WARM
OVER OUR REGION. THE HRRR SHOWS THE PRECIP MOVING INTO THE
SOUTHERN/WESTERN PIEDMONT AROUND 08Z. THIS IS GENERALLY IN AGREEMENT
WITH THE LARGE SCALE MODELS...WHICH SHOW THE HEAVIEST RAINFALL
AMOUNTS...0.50-0.75"...ACROSS THE SOUTHERN PIEDMONT THROUGH 12Z
TUESDAY. PW WILL BE INCREASING TO WELL OVER 1.5"...SO SOME OF THE
RAIN COULD BE LOCALLY HEAVIER...BUT INSTABILITY LOOKS VERY MEAGER
WITH WEAK LAPSE RATES ALOFT DESPITE THE WARM ADVECTION AND LOW LEVEL
JETTING. WITH DEWPOINTS RECOVERING AHEAD OF THE PRECIP TONIGHT...
LOWS SHOULD END UP IN THE MID 40S NORTHWEST TO MID 50S.

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 305 PM MONDAY...

ONGOING SHOWERS WILL SHIFT NORTH AND EAST TUESDAY MORNING AS THE LOW
LEVEL JET SURGES OFF TO THE NORTHEAST. BUFR SOUNDINGS SHOW SOME
MARKEDLY DRIER MID-LEVEL AIR THAT SHOULD RENDER MUCH OF THE AIR FREE
OF PRECIP BY TUESDAY AFTERNOON...ALTHOUGH SHALLOW ISENTROPIC LIFT
COULD STILL SUPPORT SOME DRIZZLE ACROSS THE WESTERN PIEDMONT. THIS
FORECAST WILL DRASTICALLY CUT BACK POPS AFTER 18Z...AND CHANCE POPS
MAY STILL BE TOO HIGH. ALL GUIDANCE GIVES HIGHS IN THE 60S BY
TUESDAY AFTERNOON...BUT GIVEN THAT THERE WILL BE NO AIRMASS CHANGE
AFTER THE PRECIPITATION TONIGHT...ITS KINDA HARD TO UNDERSTAND THE
NORTHWEST PIEDMONT REACHING 60. MET GUIDANCE IS ONE OF THE ONLY
MODELS TO GIVE UPPER 50S...SO WILL GO WITH UPPER 50S NORTHWEST TO
NEAR 70 SOUTHEAST.

ANOTHER ROUND OF PRECIP WILL BE HEADING OUT EAST TUESDAY NIGHT AS A
DEEPER TROUGH MOVES THROUGH THE CENTRAL US AND THE LOW LEVEL
JET/WARM ADVECTION INTENSIFY OVER THE SOUTHEAST US ONCE AGAIN. THE
PREFERRED GFS AND ECMWF TAKE THE HEAVIEST QPF THROUGH THE MOUNTAINS
AS THE LOW LEVEL FLOW BACKS AROUND TO MORE SOUTHEASTERLY...BUT WITH
PW STILL WELL ABOVE NORMAL AND STRONG WARM ADVECTION...WILL CARRY
LIKELY POPS AFTER 00Z AND CATEGORICAL ACROSS THE WEST. THE
PROBABILITY THUNDER STILL LOOKS LOW GIVEN WEAK LAPSE RATES..THOUGH
THE CHANCE MAY BE SLIGHTLY HIGHER THAN TONIGHT WITH A STRONGER LOW
LEVEL JET. IT STILL LOOKS TOO ISOLATED TO INCLUDE IN THE FORECAST
FOR NOW. LOWS WILL BE MILDER IN THE UPPER 60S TO LOWER 70S.

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 1055 AM MONDAY...

...WIDESPREAD RAIN WED INTO WED NIGHT...
...ABOVE NORMAL TEMPS TO PERSIST THROUGH THE WEEKEND...

WED/THU: SHORTWAVE ENERGY DIVING SOUTHEAST THROUGH THE PACIFIC NW
AND NORTHERN CA TONIGHT WILL AMPLIFY A LONGWAVE TROUGH OVER THE
INTERMOUNTAIN WEST AND DESERT SW ON TUE. CYCLOGENESIS WILL OCCUR
OVER THE CENTRAL PLAINS TUE NIGHT AS THE AMPLIFYING TROUGH
PROGRESSES ACROSS THE ROCKIES. AN ENERGETIC SFC CYCLONE WILL
ACCOMPANY THE UPPER TROUGH AS IT LIFTS NORTHEAST THROUGH THE
NORTHERN GREAT LAKES ON WED AND INTO CANADA WED NIGHT. DOWNSTREAM
ACROSS THE SOUTHEAST...SOUTHERLY LOW-LEVEL FLOW EMANATING FROM THE
GOMEX WILL STRENGTHEN IN CONCERT WITH STRENGTHENING SW FLOW ALOFT
AND TRANSPORT AN UNSEASONABLY MOIST AIRMASS INTO THE CAROLINAS (PWAT
VALUES > 1.50" AND SFC DEWPOINTS IN THE 60S TO NEAR 70F). GIVEN WELL
ABOVE NORMAL MOISTURE IN THE PRESENCE OF BROAD WARM ADVECTION AND
OCCASIONAL BOUTS OF DPVA ATTENDANT SMALL AMPLITUDE WAVES IN SW FLOW
ALOFT...EXPECT WIDESPREAD MODERATE TO OCCASIONALLY HEAVY RAIN WED
INTO WED NIGHT...WITH PRECIP AMOUNTS ~1.00" (LOCALLY HIGHER AMOUNTS
IN NW PIEDMONT). 1000-850 MB THICKNESSES SUPPORT ABOVE NORMAL
TEMPERATURES WED/THU. CLOUD COVER AND RAIN WILL HELP MODERATE TEMPS
ON WED (UPPER 60S TO LOWER 70S)...THOUGH LESS SO ON THU (MID/UPPER
70S) AS THE BEST WARM ADVECTION SHIFTS NORTH INTO THE MID-ATLANTIC
AND PRECIP CHANCES DIMINISH TO ISOLD/SCT DIURNAL SHOWERS. AT THIS
TIME DO NOT ANTICIPATE A CHANCE FOR THUNDER GIVEN MOIST-ADIABATIC
THERMAL PROFILES AND NO SIGNIFICANT FORCING...PARTICULARLY W/REGARD
TO DPVA/LAYER-LIFTING. DESPITE A LACK OF THUNDER...TIGHTENING OF THE
LOW-LEVEL HEIGHT/MSLP GRADIENT MAY YIELD GUSTY SOUTHWEST WINDS WED
AFTERNOON AND AGAIN ON THU...WITH WIND GUSTS UP TO ~45 MPH POSSIBLE
IN HEAVIER CONVECTION.

FRI-MON: THE COLD FRONT ASSOC/W THE UPPER LEVEL TROUGH AND ATTENDANT
SFC CYCLONE RAPIDLY PROGRESSING INTO CANADA WILL RAPIDLY WEAKEN AS
IT PROGRESSES EAST OF THE APPALACHIANS...BECOMING WSW-ENE ORIENTED
BEFORE STALLING IN VICINITY OF THE CAROLINA/SOUTHEAST COAST FRI.
LONG RANGE GUIDANCE DIVERGES SUBSTANTIALLY SAT-MON...APPARENTLY AS A
RESULT OF UNCERTAINTY IN THE EVOLUTION OF A POTENT UPPER LEVEL WAVE
(MOVING ASHORE THE NORTHERN CA/PACIFIC COAST FRI) EXPECTED TO
AMPLIFY INTO A CLOSED LOW OVER SOUTHERN CA AND THE DESERT SW THIS
WEEKEND BEFORE PROGRESSING SLOWLY EAST/NE INTO PORTIONS OF THE
CENTRAL CONUS BY EARLY NEXT WEEK. WITH THE ABOVE IN MIND...EXPECT
ABOVE NORMAL TEMPERATURES (TEMPERED BY BROKEN TO OVERCAST CLOUD
COVER) TO PERSIST OVER THE WEEKEND WITH VERY LITTLE POTENTIAL FOR
PRECIPITATION ASIDE FROM A FEW SPRINKLES OR AN OCCASIONAL SHOWER.
FORECAST UNCERTAINTY INCREASES DRAMATICALLY BY EARLY NEXT WEEK...
THOUGH PRECIP CHANCES SHOULD GENERALLY INCREASE FROM WEST-EAST
MON/TUE AS A COLD FRONT APPROACHES FROM THE WEST. -VINCENT

.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 1235 PM MONDAY...

OTHER THAN SOME 2000 FT STRATUS LINGERING IN THE FOOTHILLS AND
WESTERN PIEDMONT...VFR CONDITIONS ARE EXPECTED TO CONTINUE ACROSS
CENTRAL NC THIS AFTERNOON. THE MVFR CEILINGS AT KGSO AND KINT MAY
BRIEFLY SCATTER OUT THROUGH 00Z...BUT SHOULD COME BACK IN TONIGHT AS
A MOISTURE CONTINUES TO INCREASE WITH WARM ADVECTION AHEAD OF A COLD
FRONT MOVING THROUGH THE MISSISSIPPI VALLEY REGION. AN UPPER TROUGH
LIFTING THROUGH THE MIDWEST TONIGHT WILL HELP TO SPREAD RAIN INTO
CENTRAL NC FROM THE SOUTHWEST AFTER 06Z...BRINGING IFR OR LIFR
CONDITIONS TO MOST...IF NOT ALL...TERMINALS LATE TONIGHT AND EARLY
TUESDAY. MODELS APPEAR TO BE A LITTLE SLOWER WITH THE ARRIVAL OF
THE RAIN AND LOW CLOUDS...WITH SOME INDICATIONS FROM KRDU TO THE
EAST MAY STAY VFR OR MVFR THROUGH 12Z. OVERALL...FORECAST
CONFIDENCE IS BELOW AVERAGE.

LONG TERM: A TUMULTUOUS PERIOD FOR AVIATION CONDITIONS AS A SLUG OF
MOISTURE MOVES OUT OF THE GULF OF MEXICO AND OVER THE SOUTHEASTERN
CONUS...WHICH COULD POTENTIALLY PRODUCE SEVERAL EXTENDED PERIODS OF
RAIN THROUGH THE WEEK AND INTO THE WEEKEND.

.CLIMATE...

DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)

DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)

.RAH WATCHES/WARNINGS/ADVISORIES... NONE.

SYNOPSIS...22
NEAR TERM...22
SHORT TERM...22
LONG TERM...VINCENT
AVIATION...22
CLIMATE...HARTFIELD/BLAES

AREA FORECAST DISCUSSION

NWS RALEIGH NC

1235 PM EST MON DEC 21 2015

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...

WATER IMAGERY THIS MORNING SHOWS A LONG FETCH OF MOISTURE FROM THE
PACIFIC ACROSS THE SOUTHERN US SOUTHWESTERLY DEEP LAYER FLOW SETS IN
FOR MUCH OF THE WEEK. REGIONAL 12Z RAOBS...NAMELY KFFC AND
KGSO...SHOW STEADY MOISTENING ALOFT THAT WILL KEEP SKIES CLOUDY
TODAY EVEN IF THE BLANKET OF STRATOCU OVER CENTRAL THIS MORNING
THINS OUT..WHICH RECENT RAP SOUNDINGS SUGGEST ACTUALLY WONT HAPPEN.
ADDITIONAL MOISTENING FROM WARM ADVECTION OVER THE WESTERN PIEDMONT
WILL RESULT IN SOME LOWER STRATUS BY THIS AFTERNOON. CURRENT FORECAST
HIGHS LOOKS TO AGREE WELL WITH INCREASING MID-CLOUD COVER...SO WILL
NUDGE THEM DOWN A COUPLE DEGREES GIVEN THE PERVASIVE 3-5K FT
CEILINGS...ESPECIALLY ACROSS THE WEST WHERE MULTIPLE LAYER OF CLOUDS
WILL STRONGLY INHIBIT HEATING. HIGHS SHOULD TOP IN THE LOWER 50S
WEST TO LOWER 60S EAST. -22

RAIN CHANCES WILL INCREASE THIS EVENING IN THE WEST AS SATURATION
BEGINS TO OCCUR AND PRECIPITABLE WATER VALUES CLIMB TO 1.25 INCHES.
ACCORDING TO 500 MB VORTICITY...THE FIRST REAL WAVE OF DYNAMICS
SHOULD HOLD OFF UNTIL BETWEEN 6 AND 12Z WHEN LOW LEVEL ISENTROPIC
LIFT REALLY BEGINS TO INCREASE SIGNIFICANTLY. NOT MORE THAN A FEW
HUNDREDTHS OF AN INCH OF QPF SHOULD ACCUMULATE BEFORE 12Z TUESDAY
BUT THIS INCREASE IN MOISTURE WILL REALLY LIMIT LOW TEMPERATURES
FROM DROPPING OVERNIGHT WITH LOWS IN THE TRIAD BOTTOMING OUT IN THE
UPPER 50S TO MID 50S IN THE SOUTHEAST.

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 325 AM MONDAY...

RAIN CHANCES WILL OVERSPREAD THE ENTIRE CWA ON TUESDAY AS SEVERAL
SHORT WAVES CROSS THE AREA FROM THE SOUTH. CONVECTIVE ALLOWING
MODELS DIFFER A LITTLE BIT ON THE INTENSITY AND COVERAGE OF THE
RAINFALL...SO WOULD NOT BE SURPRISED TO SEE A FEW PERIODS OF HEAVIER
RAIN...FOLLOWED BY SOME LULLS...MOST LIKELY CORRESPONDING TO THE
DIFFERENT WAVES MOVING THROUGH THE AREA. QPF VALUES WILL MOST LIKELY
BE BETWEEN A HALF OF AN INCH AND AN INCH ON TUESDAY. EXPECT OVERCAST
SKIES FOR THE DURATION OF THE DAY BUT INCREASING WARM AIR ADVECTION
WILL BRING HIGH TEMPERATURES GENERALLY INTO THE 60S WITH LOW 60S IN
THE NW PIEDMONT AND UPPER 60S IN THE SOUTHEAST. BY TUESDAY NIGHT A
SECOND STRONGER WAVE OF PRECIPITATION WILL MOVE INTO WESTERN AREAS
OF THE CWA. DESPITE RAIN CHANCES ALL DAY...FLASH FLOOD GUIDANCE
REMAINS FAIRLY HIGH AND MMEFS INDICATES THAT MAIN STREAM RIVERS
SHOULD REMAIN BELOW FLOOD STAGE. LOW TEMPERATURES TUESDAY NIGHT WILL
ONLY FALL INTO THE MID 50S TO POTENTIALLY NEAR 60 DEGREES IN THE
SOUTHEAST. THIS IS A GOOD 25 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR AND WONT EVEN BE THE WARMEST LOWS OF THE WEEK.

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 315 AM MONDAY...

WED THROUGH WED NIGHT: PERSISTENT UPPER LEVEL SOUTHWESTERLY FLOW
WILL CONTINUE...WITH SOUTHERLY FLOW AT THE SURFACE ADVECTING WARM
MOIST AIR INTO THE REGION. AN UPPER LEVEL SHORTWAVE WILL IMPINGE ON
THE CAROLINAS AS IT TRAVERSES THE EASTERN EDGE OF THE TROUGH OVER
THE MIDWEST...HELPING TO PROVIDE SUFFICIENT LIFT IN THE SATURATED
COLUMN TO PRODUCE SOME SIGNIFICANT RAINFALL. AS A RESULT...RAIN WILL
BE LIKELY DURING THE DAY AND INTO THE EARLY OVERNIGHT...WITH CHANCES
DECREASING SOME TOWARD DAYBREAK. THE SURFACE PRESSURE GRADIENT WILL
INCREASE DURING THE AFT/EVE...RESULTING IN INCREASING WIND SPEEDS.
HIGHS IN THE UPPER 60S TO MID 70S. LOWS IN THE LOW TO MID 60S.

THURSDAY AND THURSDAY NIGHT: STILL SOME DIFFERENCES IN THE MODELS
WITH RESPECT TO PRECIPITATION...THUS FORECAST UNCERTAINTY IS STILL
SOMEWHAT HIGH. HOWEVER...IT IS LOOKING MORE AND MORE LIKE THURSDAY
COULD BE RELATIVELY DRY...WITH JUST A SLIGHT CHANCE TO CHANCE OF
SOME RAIN. HIGHEST TEMPERATURES OF THE LONG TERM ARE STILL EXPECTED
ON THURSDAY AS THE SOUTHERLY WARM ADVECTION PEAKS. HIGHS IN THE LOW
70S NW TO UPPER 70S SE. LOWS UPPER 50S TO MID 60S.

FRIDAY ONWARD: THE APPROACHING FRONT WILL WEAKEN AS IT BECOMES MORE
WEST-EAST ORIENTED OVER VA/MD ON FRIDAY. THE MEDIUM RANGE MODELS
KEEP THE FRONT TO OUR NORTH...WITH UPPER LEVEL RIDGING FROM THE SE
PERSISTING OVER NC THROUGH THE WEEKEND. HOWEVER...DIFFERENCES
BETWEEN THE MODES WITH RESPECT TO THE PROGRESSION AND LOCATION OF
THE FRONT RESULT IN SIGNIFICANT DIFFERENCES IN PRECIP CHANCES. FOR
NOW WILL AT LEAST KEEP A SLIGHT CHANCE IN THROUGH THE EXTENDED UNTIL
BETTER AGREEMENT IS SEEN...HOWEVER THERE IS A DESCENT CHANCE MUCH OF
THIS PERIOD COULD BE DRY WITH JUST A FEW SHOWERS POSSIBLE. HIGHS
THROUGH THE PERIOD WILL GENERALLY RANGE FROM THE MID 60S TO MID 70S.
LOWS WILL GENERALLY BE IN THE 50S...WITH SOME LOW 60S POSSIBLE IN
THE SOUTH.

.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 1235 PM MONDAY...

.CLIMATE...

DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)

DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)

.RAH WATCHES/WARNINGS/ADVISORIES... NONE.

SYNOPSIS...22
NEAR TERM...ELLIS/22
SHORT TERM...ELLIS
LONG TERM...KC
AVIATION...22
CLIMATE...HARTFIELD/BLAES

AREA FORECAST DISCUSSION

NWS RALEIGH NC

1055 AM EST MON DEC 21 2015

.SYNOPSIS...A SOUTHERLY FLOW OF WARMER AND MORE MOIST AIR WILL
DEVELOP TODAY AND PERSIST FOR MUCH OF THE WEEK. MEANWHILE...A COLD
FRONT WILL APPROACH THE AREA FROM THE WEST ON TUESDAY...THEN STALL
OVER THE REGION.

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 325 AM MONDAY...

.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
AS OF 1200 PM MONDAY...

...WIDESPREAD RAIN WED INTO WED NIGHT...
...ABOVE NORMAL TEMPS TO PERSIST THROUGH THE WEEKEND...

.AVIATION /12Z TUESDAY THROUGH FRIDAY/...
AS OF 645 AM MONDAY...

24 HOUR TAF PERIOD: MVFR CONDITIONS HAVE MOVED INTO THE TRIAD AT
THIS TIME BUT EASTERN SITES COULD POTENTIALLY REMAIN VFR THROUGH
MOST OF THE TAF PERIOD WITH MVFR CEILINGS CREEPING INTO THE EAST
BETWEEN 00Z AND 06Z TUESDAY. RAIN CHANCES WILL ALSO AS THE TAF
PERIOD GOES ON WITH SOME LIGHT SPRINKLES SHOWING UP ON HIGH
RESOLUTION MODELS IN THE EAST BEFORE MORE SUBSTANTIAL RAIN CHANCES
INCREASE FROM WEST TO EAST EARLY TUESDAY MORNING.

.CLIMATE...

DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)

DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)

.RAH WATCHES/WARNINGS/ADVISORIES... NONE.

SYNOPSIS...22
NEAR TERM...ELLIS/22
SHORT TERM...ELLIS
LONG TERM...VINCENT
AVIATION...ELLIS
CLIMATE...HARTFIELD/BLAES

AREA FORECAST DISCUSSION

NWS RALEIGH NC

930 AM EST MON DEC 21 2015

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 325 AM MONDAY...

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 315 AM MONDAY...

.AVIATION /12Z TUESDAY THROUGH FRIDAY/...
AS OF 645 AM MONDAY...

.CLIMATE...

DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)

DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)

.RAH WATCHES/WARNINGS/ADVISORIES... NONE.

SYNOPSIS...22
NEAR TERM...ELLIS/22
SHORT TERM...ELLIS
LONG TERM...KC
AVIATION...ELLIS
CLIMATE...HARTFIELD/BLAES

AREA FORECAST DISCUSSION

NWS BISMARCK ND

957 PM CST TUE DEC 22 2015

.UPDATE...
ISSUED AT 934 PM CST TUE DEC 22 2015

...WILL CONTINUE THE WINTER STORM WARNING FAR NORTH CENTRAL...

SURFACE LOW PRESSURE OVER EAST CENTRAL NORTH DAKOTA WITH UPPER LOW
OVER SOUTHWEST MANITOBA. WARM SECTOR PRECIPITATION HAS PRETTY MUCH
LIFTED NORTH THROUGH NORTHERN MINNESOTA WITH MAINLY WRAP AROUND
MOISTURE CAUGHT IN THE DEFORMATION ZONE THAT STRETCHES BACK WEST
ACROSS NORTHERN NORTH DAKOTA AND INTO NORTHEAST MONTANA. LIGHT
SNOW STILL CONTINUING OVER NORTHERN PORTIONS OF PIERCE AND MCHENRY
COUNTY AND PRETTY MUCH MOST OF ROLETTE AND BOTTINEAU COUNTIES.
LATEST MESOSCALE MODELS CONTINUE TO INDICATE THIS AREA OF
PRECIPITATION REMAINING OVER THE WARNING AREA THROUGH AT LEAST 06
UTC AND THEN DISSIPATING...LIFTING NORTH THEREAFTER...WHILE WEAK
SHORTWAVE ENERGY PUSHES FROM NORTHEAST MONTANA INTO WESTERN NORTH
DAKOTA. HAVE UPDATE POPS TO KEEP CATEGORICAL POPS ACROSS THE
NORTH THROUGH 06 UTC...AND THEN SLOWLY TAPERING TO CHANCE POPS
AROUND 12Z. A DEEP DENDRITIC GROWTH LAYER REMAINS ACROSS NORTHERN
NORTH DAKOTA...AND OCCASIONAL BANDS OF HIGHER REFLECTIVITIES
CONTINUE TO DEVELOP ACROSS THE WARNING AREA. THEREFORE WILL
CONTINUE THE WARNING FOR NOW AND WILL TONE DOWN THE ADDITIONAL
SNOWFALL AMOUNTS. MANY AREAS WITHIN THE WARNING AREA HAD RECEIVED
4 TO 7 INCHES THROUGH LATE AFTERNOON...SO COULD SEE SOME MORE
REPORTS OF 6-8 INCHES WHEN MORNING REPORTS COME IN THURSDAY.
WARNING DOES EXPIRE AT 12 UTC BUT THE OVERNIGHT SHIFT CAN CANCEL
EARLY IF SNOW ENDS.

BACK IN NORTHWEST NORTH DAKOTA...LITTLE IF ANY SNOW FELL DURING
THE DAY WEDNESDAY...BUT WITH SNOW THIS EVENING...CONINUING INTO
THURSDAY MORNING...WOULD EXPECT A FEW REPORTS OF 1-2 INCHES.

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 253 PM CST TUE DEC 22 2015

HEAVY SNOW NORTH CENTRAL THROUGH EARLY THIS EVENING HIGHLIGHTS THE
SHORT TERM FORECAST.

AS OF 2130 UTC...A SECONDARY SHORTWAVE EVIDENT ON WATER VAPOR HAS
PROPAGATED NORTHEAST OUT OF NORTH CENTRAL SOUTH DAKOTA INTO SOUTH
CENTRAL NORTH DAKOTA...AS REFLECTED IN THE INTENSIFICATION OF
SNOWFALL ACROSS SOUTH CENTRAL NORTH DAKOTA OVER THE PAST ONE TO
TWO HOURS. THIS WAVE WILL CONTINUE TO PROPAGATE NORTHEAST AND
INTERACT WITH THE TROWAL ACROSS NORTH CENTRAL AND NORTHEAST NORTH
DAKOTA TO CONTINUE TO SUPPORT HEAVY SNOWFALL THROUGH EARLY THIS
EVENING. THE 17-20 UTC HRRR AND RAP ITERATIONS HAVE HANDLED THE
MESOSCALE BANDING OF SNOWFALL WELL THROUGH THE AFTERNOON AND WILL
FOLLOW THEIR SOLUTIONS THROUGH THE EVENING...BLENDED TO THE 12 UTC
GLOBAL SUITE LATE TONIGHT INTO WEDNESDAY MORNING. OVERALL...STORM
TOTAL SNOWFALL ACCUMULATIONS OF 6 TO 8 INCHES REMAIN UNCHANGED FOR
THE TOWNER...RUGBY...BOTTINEAU AND ROLETTE AREAS...WITH LOCALLY
HIGHER AMOUNTS. ELSEWHERE FOR TONIGHT INTO WEDNESDAY
MORNING...LIGHT SNOW IS EXPECTED. THIS IS IN ASSOCIATION WITH THE
WEAKENING TROWAL AND A WAVE CURRENTLY ACROSS NORTH CENTRAL
MONTANA THAT WILL PROPAGATE SOUTHEAST. ADDITIONAL SNOWFALL
ACCUMULATIONS OF AROUND ONE...TO POSSIBLY TWO INCHES ACROSS THE
WEST INTO THE SOUTH CENTRAL ARE FORECAST.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 253 PM CST TUE DEC 22 2015

COOLING TEMPERATURES INTO THE WEEKEND HIGHLIGHT THE EXTENDED
FORECAST.

THE 12 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN AGREEMENT ON
A BROAD...UPPER LEVEL WESTERN AND CENTRAL CONUS TROUGH TO BEGIN
THE PERIOD TO POSSIBLY TRANSITION TO SPLIT FLOW BY THE
WEEKEND...POTENTIALLY PLACING THE NORTHERN PLAINS IN NORTHWEST
FLOW ALOFT WITH THE NORTHERN STREAM. THIS SUPPORTS A POSSIBLE COOL
DOWN INTO THE WEEKEND. OVERALL...THE CHRISTMAS TRAVEL OUTLOOK
LOOKS GOOD WITH RATHER QUIET WEATHER.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 934 PM CST TUE DEC 22 2015

MVFR TO OCCASIONAL IFR CONDITIONS ARE EXPECTED ACROSS WESTERN AND
CENTRAL NORTH DAKOTA TONIGHT AND THROUGH MUCH OF THE DAY ON
THURSDAY. LIGHT WEST FLOW TONIGHT WILL TURN NORTH TO NORTHWEST
AND INCREASE TO UP TO 15 MPH ON THURSDAY.

.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 AM CST WEDNESDAY FOR NDZ004-005-012-
013.

UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...TWH

AREA FORECAST DISCUSSION

NWS BISMARCK ND

249 PM CST MON DEC 21 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 215 PM CST MON DEC 21 2015

FOG TONIGHT AND ACCUMULATING SNOW TUESDAY HIGHLIGHT THE SHORT TERM
FORECAST.

THE 15-19 UTC HRRR ITERATIONS AND THE 12 UTC NAM NEST ONCE AGAIN
TONIGHT DEPICT FOG DEVELOPMENT WITHIN THEIR RESPECTIVE VISIBILITY
FIELDS. THESE FORECASTS HAVE PERFORMED WELL THE PAST WEEK IN
SIGNALING FOG...AND WILL FOLLOW THEIR SOLUTIONS WHICH SUGGEST FOG
GENERALLY ALONG AND EAST OF HIGHWAY 83 TONIGHT INTO EARLY TUESDAY
MORNING BEFORE THE SNOWFALL. A DENSE FOG ADVISORY MAY BE
POSSIBLE.

FOR TUESDAY...THE 12 UTC AND INCOMING 18 UTC DETERMINISTIC AND
ENSEMBLE SUITES ARE IN AGREEMENT ON A WAVE EJECTING NORTHEAST OUT
OF WYOMING...DEEPENING AND POTENTIALLY CLOSING OFF AS IT
PROPAGATES ACROSS NORTH DAKOTA. STRONG FRONTOGENETIC FORCING AND
VERTICAL MOTION IN THE DENDRITIC GROWTH LAYER ARE EXPECTED ALONG
AND NORTH OF THE 700 MB LOW TRACK FROM SOUTHWEST THROUGH NORTHEAST
NORTH DAKOTA TO SUPPORT MESOSCALE BANDING OF SNOW. THE GREATEST
SNOWFALL AMOUNTS OF 3 TO 5 INCHES ARE FORECAST ACROSS THE FAR
NORTH CENTRAL AND TURTLE MOUNTAINS WHERE SNOWFALL DURATION WILL BE
THE LONGEST IN ASSOCIATION WITH THE DEVELOPING TROWAL. THUS...HAVE
ISSUED A WINTER WEATHER ADVISORY FOR THESE AREAS. FOR NOW...THE
LACK OF STRONG ELEVATED INSTABILITY IS EXPECTED TO KEEP SNOWFALL
AMOUNTS BELOW WARNING LEVELS. HOWEVER...THIS WILL HAVE TO BE
CLOSELY MONITORED IN THE MODEL SOLUTIONS OVER THE NEXT 12 HOURS.
ELSEWHERE...WIDESPREAD ONE TO THREE INCH SNOWFALL AMOUNTS ARE
EXPECTED.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 215 PM CST MON DEC 21 2015

SURFACE LOW AND ASSOCIATED MID/UPPER LEVEL TROUGH WILL EXIT THE
TURTLE MOUNTAINS AND SHIFT INTO SOUTHERN ONTARIO BY 12Z WEDNESDAY.
SNOW WILL GRADUALLY DIMINISH AND END TUESDAY NIGHT WITH A COLD
POCKET/THERMAL TROUGH LINGERING THROUGH WEDNESDAY. THIS WILL RESULT
IN PLENTY OF CLOUDS AND POSSIBLE FLURRIES WEDNESDAY. ANOTHER WEAK
SHORTWAVE IS EXPECTED THURSDAY AFTERNOON/EVENING...BUT ANY
PRECIPITATION THREAT IS VERY MINIMAL. A SPLIT FLOW DEVELOPS FOR
THE REST OF THE EXTENDED PERIOD AS AN UPPER TROUGH/LOW IS CARVED
OUT IN THE SOUTHWEST. NORTH DAKOTA FALLS UNDER A SOUTHWEST FLOW
ALOFT CHRISTMAS DAY/FRIDAY...WITH A DEFORMATION ZONE EVOLVING
ACROSS SOUTHERN NORTH DAKOTA FRIDAY NIGHT INTO SATURDAY MORNING.
CHRISTMAS DAY REMAINS DRY WITH MOISTURE ADVECTION INCREASING
FRIDAY EVENING FAR SOUTH. THIS IS IN RESPONSE TO AN INITIAL
MID/UPPER LEVEL LOW EJECTING FROM THE SOUTHWEST UPPER TROUGH WILL
SLIDE ACROSS SOUTH DAKOTA DURING THE ABOVE TIME. WILL CONTINUE TO
WATCH THE TRACK BUT AS OF NOW SOME LIGHT SNOW IS EXPECTED SOUTH OF
I-94 DURING THIS TIME. THIS SHORTWAVE DEPARTS SATURDAY NIGHT WITH
DRY WEATHER UNTIL AT LEAST MONDAY. HIGHS WILL REMAINING IN THE 20S
WED/THU...THEN COLDER AIR WILL BE DRAWN INTO THE APPROACHING
SOUTHWEST SYSTEM WITH WINDS BECOMING NORTH TO NORTHEAST FRI/SAT.
AS THE SYSTEM DEPARTS AND WINDS BECOME SOUTHWEST...HIGHS WILL ONCE
AGAIN REBOUND INTO THE 20S SUNDAY AND MONDAY. OVERNIGHT LOWS WILL
BE COLDEST FRIDAY MORNING THROUGH SUNDAY MORNING WITH LOWS 5 BELOW
ZERO NORTH TO 5 ABOVE ZERO SOUTH.

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM CST MON DEC 21 2015

LIFR/VLIFR FOG AND STATUS AT KBIS/KMOT WILL SLOWLY IMPROVE POSSIBLY
TO VFR BY LATE THIS AFTERNOON THROUGH EARLY EVENING.
HOWEVER...ANOTHER ROUND OF FOG AND STRATUS MAY BE POSSIBLE
TONIGHT. LIFR/VLIFR CONDITIONS AT KJMS CONTINUING THROUGH THE
NIGHT. VFR CONDITIONS EXPECTED AT KDIK/KISN THROUGH THE EVENING.
WIDESPREAD SNOW AND IFR CONDITIONS ARE EXPECTED ACROSS THE AREA
ON TUESDAY.

.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 AM TUESDAY TO MIDNIGHT CST
TUESDAY NIGHT FOR NDZ005-012-013-022-023-025.

SHORT TERM...AYD
LONG TERM...KS
AVIATION...AYD

AREA FORECAST DISCUSSION

NWS BISMARCK ND

1252 AM CST MON DEC 21 2015

.UPDATE...
ISSUED AT 1253 AM CST MON DEC 21 2015

DENSE FOG ADVISORY CONTINUES FOR MUCH OF WEST AND CENTRAL NORTH
DAKOTA...AND EXPANDED THE ADVISORY TO INCLUDE MORE COUNTIES IN THE
SOUTHWEST AND IN THE NORTH CENTRAL. VISIBILITIES HAD IMPROVED AT
WILLISTON THE PAST COUPLE OF HOURS...BUT JUST EAST OF THERE
VISIBILITIES WERE 1/2-1/4 MILE. EXPANDED THE ADVISORY TO INCLUDE
DICKINSON AND HETTINGER (HETTINGER WAS ALREADY AT 1/4 MILE AND
SHORT TERM MODELS HAVE THIS EXPANDING NORTHWARD). ALSO EXPANDED
THE ADVISORY INTO BOTTINEAU...ROLETTE AND MCHENRY AND PIERCE
COUNTIES. OTHER CHANGE WAS RAISING MIN TEMPS FOR PARTS OF THE
SOUTH CENTRAL INTO THE JAMES VALLEY.

UPDATE ISSUED AT 834 PM CST SUN DEC 20 2015

HAVE ISSUED A DENSE FOG ADVISORY FOR MUCH OF NORTHWEST AND CENTRAL
NORTH DAKOTA. VISIBILITIES ON AREA WEATHER CAMERAS AND SURFACE
OBSERVATIONS BEGAN DROPPING QUICKLY AFTER 7 PM CENTRAL...MAINLY
ABOUT 30 TO 50 MILES EITHER SIDE OF THE MISSOURI RIVER VALLEY FROM
WILLISTON TO THE SOUTH DAKOTA LINE.

SURFACE HIGH PRESSURE OVER NORTHEAST NORTH DAKOTA IS KEEPING THE
DENSE FOG OUT OF THE EASTERN PORTIONS OF CENTRAL NORTH DAKOTA...AT
LEAST FOR THE TIME BEING. CLEAR TO PARTLY CLOUDY SKIES AND
CURRENTLY NO FOG IN THE SOUTHWEST WHERE SKIES WHICH SAW SOME SUN
TODAY. HOWEVER DEWPOINT DEPRESSIONS CONTINUE TO DROP HERE. THE
LATEST HRRR AND RAP MESOSCALE MODELS SHOW THE LOW STRATUS AND FOG
SPREADING EAST LATER TONIGHT AS THE SURFACE HIGH IN NORTHEAST ND
MOVES EAST. THESE MODELS ARE ALSO SHOWING LOW STRATUS RETURNING TO
THE SOUTHWEST AFTER MIDNIGHT. THUS IF THESE MODELS ARE CORRECT WE
MAY NEED TO ADD ON TO THE CURRENT ADVISORY LATE TONIGHT. FOR NOW
THOUGH IT DEPICTS WELL WHERE CURRENT VISIBILITIES ARE LOWEST.

TEXT PRODUCTS HAVE BEEN UPDATED

UPDATE ISSUED AT 633 PM CST SUN DEC 20 2015

WIDESPREAD STRATUS COVERS ALL OF CENTRAL NORTH DAKOTA ALONG AND
EAST OF THE HIGHWAY 83 CORRIDOR. WEST OF HERE...STRATUS ENDS OVER
BURKE AND MOUNTRAIL...SOUTH THROUGH MERCER...MORTON...GRANT AND
SIOUX COUNTIES. THEN A NARROW BREAK THE CLOUDS AND CLEAR
SKIES...WITH STRATUS AGAIN IN THE FAR WEST INTO NORTHEAST MONTANA.

FIRST THIS CLEAR STRIP IS WREAKING HAVOC WITH TEMPERATURES HAVE
FALLEN TO NEAR THE SINGLE DIGITS...WITH A 9 DEGREE F READING AT
TIOGA AT 6 PM CENTRAL. NOT FAR EITHER SIDE OF THIS CLEAR SPOT...
TEMPERATURES ARE IN THE LOWER TO MIDDLE 20S.

SECOND...ALTHOUGH VISIBILITIES HAVE IMPROVED OVER MOST OF
NORTHWEST NORTH DAKOTA...THERE REMAINS A SMALL AREA OF LOW
VISIBILITIES ON THE WESTERN EDGE OF THE STRATUS OVER CENTRAL NORTH
DAKOTA...ADJACENT TO THE NARROW CLEAR STRIP. THE HRRR AND HRRREXP
MESOSCALE MODELS EXPAND THE AREA OF LOW STRATUS ACROSS A GOOD
PORTION OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT...WHILE THE
NAMNEST AND RUC ARE NOT AS VIGOROUS EXPANDING THE LOWER
VISIBILITIES. DID ALLOW THE DENSE FOG ADVISORY TO EXPIRE BUT
DEPENDING ON HOW THINGS TREND THIS EVENING WE MAY NEED TO ISSUE
ANOTHER DENSE FOG ADVISORY LATER THIS EVENING.

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 242 PM CST SUN DEC 20 2015

FOG AND PATCHY FREEZING DRIZZLE TONIGHT HIGHLIGHT THE SHORT TERM
FORECAST.

THE DENSE FOG ADVISORY ACROSS NORTHWEST NORTH DAKOTA REMAINS IN
EFFECT UNTIL 00 UTC. CERTAINLY POSSIBLE THAT THE ADVISORY MAY
NEED TO BE EXPANDED IN TIME AND OR AREA THROUGH THE EVENING AND
OVERNIGHT AS CURRENT STRATUS ACROSS WESTERN AND CENTRAL NORTH
DAKOTA IS EXPECTED TO BUILD DOWN POTENTIALLY INTO FOG. THIS
SCENARIO IS SUPPORTED BY THE 18 UTC NAM NEST AND 16-19 UTC HRRR
ITERATION VISIBILITY FORECASTS AND THE 12 UTC NAM/GFS BUFR
SOUNDINGS. GIVEN A DRY LAYER FORECAST TO BE ABOVE THE STRATUS DECK
TO SUBLIMATE ANY ICE CRYSTALS FROM MID TO UPPER LEVEL
CLOUDS...PATCHY FREEZING DRIZZLE IS ALSO POSSIBLE. DO NOT HAVE A
GREAT AMOUNT OF CERTAINTY REGARDING THE FREEZING DRIZZLE
POTENTIAL. THUS...CONFINED THE MENTION TO THE HIGHER TERRAIN OF
THE WEST WHERE CEILINGS ARE EXPECTED TO BE LOWEST.

FOR MONDAY...THE 12 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN
GOOD AGREEMENT ON A RAPIDLY PROPAGATING SHORTWAVE ACROSS NORTH
DAKOTA TO SUPPORT A BAND OF LIGHT SNOW GENERALLY ACROSS THE CENTRAL
AND EAST. SNOWFALL ACCUMULATIONS OF LESS THAN ONE INCH ARE
EXPECTED.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 242 PM CST SUN DEC 20 2015

ACCUMULATING SNOWFALL POTENTIAL TUESDAY HIGHLIGHTS THE EXTENDED
FORECAST.

THE 12 AND INCOMING 18 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE
IN AGREEMENT ON A SHORTWAVE EJECTING OUT OF WYOMING TUESDAY
MORNING...AND DEEPENING AS IT PROPAGATES EAST-NORTHEAST ACROSS
NORTH DAKOTA THROUGH THE DAY. LIGHT TO MODERATE SNOWFALL
ACCUMULATIONS MAY BE POSSIBLE...ESPECIALLY ACROSS NORTH CENTRAL
NORTH DAKOTA AND INTO THE JAMES RIVER VALLEY. HOWEVER...THE
HEAVIEST AMOUNTS AS OF NOW LOOK TO BE POSSIBLY FOCUSED OUTSIDE OF
THE CWA ACROSS NORTHEAST NORTH DAKOTA WHERE FRONTOGENETICAL
FORCING AND RESULTANT BANDING OF SNOW MAY BE GREATER. WILL
CONTINUE TO MONITOR THIS SYSTEM OVER THE COMING DAYS IN LIGHT OF
CHRISTMAS TRAVEL. THEREAFTER...THE UPPER LEVEL FLOW PATTERN OF
NEAR ZONAL ACROSS THE NORTHERN PLAINS IN THE BASE OF A VERY BROAD
AND LOW AMPLITUDE TROUGH MAY TRANSITION TO SPLIT FLOW BY LATE NEXT
WEEK AND WEEKEND. THIS WOULD SUPPORT SEASONABLE TEMPERATURES AND
RELATIVELY QUIET WEATHER.

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1253 AM CST MON DEC 21 2015

WIDESPREAD IFR-LIFR CEILINGS EXPECTED FOR MUCH OF THE OVERNIGHT
HOURS THIS MORNING WITH A VERY LIGHT SURFACE FLOW. IFR VSBYS ALSO
EXPECTED AT KBIS/KMOT...AND THINK KISN AND KJMS SHOULD BECOME IFR IN
VSBY. MORE UNSURE ABOUT KDIK AT THIS TIME. IFR CONDITIONS SHOULD
IMPROVE FROM WEST TO EAST DURING THE DAYTIME ON MONDAY...BEGINNING
AROUND 15Z-16Z AT KISN/KDIK AND DURING THE AFTERNOON HOURS MONDAY
FOR CENTRAL ND TAF SITES.

.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ001>005-009>013-017>023-033>036-041-042-044>047-050.

UPDATE...JV
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...JV

AREA FORECAST DISCUSSION

NWS CLEVELAND OH

1140 PM EST SUN DEC 20 2015

.SYNOPSIS...
HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL MOVE EAST AND
ALLOW LOW PRESSURE TO MOVE THROUGH THE GREAT LAKES REGION MONDAY
INTO TUESDAY. THE LOW WILL DRAG A WEAK COLD FRONT THROUGH THE AREA
BEGINNING LATE MONDAY NIGHT. THE FRONT WILL COME BACK NORTH AS A
WARM FRONT TUESDAY NIGHT. UNSEASONABLY WARM WEATHER WILL CONTINUE
THROUGH MID WEEK WITH ONLY A SLIGHT COOL DOWN LATE IN THE WEEK.

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CIRRUS CONTINUES TO STREAM ACROSS THE REGION. THERE COULD BE SOME
THIN SPOTS MAINLY THROUGH THE FIRST HALF OF THE NIGHT BUT ON
BALANCE BELIEVE MOSTLY CLOUDY WILL BE GOOD. BIG QUESTION IS
WHETHER THE RAIN GETS INTO THE WESTERN COUNTIES BEFORE MORNING.
LATEST HRRR AND RAP CONTINUE THEIR DIFFERENCES WITH HRRR
CONTINUING TO BE FASTER WITH EAST SPREAD OF RAIN. THUS LOW
CONFIDENCE WITH TIMING OF PRECIP LATE TONIGHT. WILL USE AVERAGING
OF THESE MODELS WHICH STILL KEEPS POPS ABOUT WHERE THEY ARE
ALREADY.

MODERATE SOUTH WINDS AND INCREASING CLOUDS WILL MAKE IT HARD FOR
TEMPS TO FALL MUCH MORE.

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
MONDAY BEGINS WITH RAIN MOVING INTO THE WEST HALF OF THE AREA.
MODELS CONTINUE TO SHOW LOW PRESSURE MOVING THROUGH THE GREAT
LAKES REGION WITH A STRENGTHENING LOW LEVEL JET AND GOOD MOISTURE
TRANSPORT INTO THE AREA. HAVE WENT WITH CATEGORICAL POPS FOR THE
ENTIRE AREA SPREADING WEST TO EAST THROUGH THE MORNING. MODELS
WRAP A DRY SLOT INTO THE WEST FOR THE AFTERNOON SO LOWERED POPS
FROM THE WEST THROUGH THE AFTERNOON. BY EVENING HOWEVER THE NAM
SHOWS A SHORT WAVE MOVING THROUGH THE BASE OF THE TROUGH IN THE
CENTRAL PLAINS. THROUGH THE OVERNIGHT THIS WAVE WILL MOVE ENE INTO
THE LOWER OHIO VALLEY. ACCORDINGLY MODELS BRING ANOTHER SLUG OF
MOISTURE INTO THE AREA FROM THE SOUTH...AFFECTING MAINLY
SOUTH/SOUTHEAST COUNTIES. SO WHILE POPS CONTINUE TO FALL ACROSS
THE NORTHWEST...HAVE HELP POPS IN THE HIGH CHANCE/LIKELY CATEGORY
FAR SOUTHEAST FOR THE SECOND HALF OF THE NIGHT. TUESDAY HIGH
PRESSURE AND DRIER AIR MOVE IN FROM THE WEST. HELD ONTO LOW
CHANCE POPS SOUTHEAST FOR THE MORNING BUT OTHERWISE SHOULD BE DRY.
TUESDAY NIGHT THE SOUTHERLY LOW LEVEL JET GETS GOING AGAIN AHEAD
OF ANOTHER LOW DEVELOPING IN THE SOUTHERN PLAINS. A WARM FRONT
EAST FROM THE LOW WILL TRACK NORTH ACROSS THE AREA OVERNIGHT
BRINGING MOIST MILD AIR BACK TO THE AREA. BROUGHT CHC POPS BACK TO
THE REGION AFTER MIDNIGHT WITH LIKELY POPS WEDNESDAY. WILL
CONTINUE LIKELY POPS WEDNESDAY NIGHT AS THE LOW...MOVING THROUGH
THE CENTRAL GREAT LAKES...DRAGS A COLD FRONT THROUGH THE AREA.
TEMPS MILD MONDAY AND TUESDAY TO SPRING-LIKE ON WEDNESDAY.

.LONG TERM /THURSDAY THROUGH SUNDAY/...
QUITE A BIT OF VARIABILITY IN THE DETAILS FOR THE HOLIDAY AND THE
END OF THE WEEK. ACTIVE WEATHER PATTERN CONTINUES...BUT THE BEST
COLD AIR DOES NOT GET A CHANCE TO REACH INTO OUR AREA WITH THE
SOUTHEAST U.S. RIDGE HOLDING ON. THE COLD FRONT FOR THURSDAY IS
TRENDING FASTER AND THAT WILL IMPACT TEMPERATURES. HAVE LOWERED THEM
BY A FEW DEGREES...BUT IF THIS TREND CONTINUES WE MAY NEED FURTHER
REDUCTION. PRECIP CHANCES ACROSS THE EAST WILL BE EXITING. HIGH
PRESSURE ACROSS THE MID MISSISSIPPI VALLEY WILL BUILD ACROSS THE
UPPER OHIO VALLEY FOR THURSDAY NIGHT AND FRIDAY. BY SATURDAY THE
PATTERN WILL BE MORE AMPLIFIED AGAIN WITH A DEEP TROUGH ACROSS THE
FOUR CORNERS REGION. LATEST ECMWF HAS COME IN LINE CLOSER TO THE GFS
IN DRAGGING/SLOWING THE SOUTHERN ENERGY ACROSS THE CONTINENT...STILL
WELL DISCONNECTED FROM THE NORTHERN JET. HAVE PRECIP CHANCES
STARTING LATE FRIDAY NIGHT AND CONTINUING THROUGH THE DAY SUNDAY.
WARM FRONTAL ZONE DEVELOPS OVERHEAD AND MOVES LITTLE AS HIGH
PRESSURE AND STRONG ZONAL FLOW REMAINS ACROSS SOUTHERN CANADA JUST
NORTH OF THE LAKES. WAVES OF LOW PRESSURE LOOK TO RIDE THE FRONT
SLOWLY SINKING IT SOUTHWARD...POSSIBLY SUNDAY. WHILE THERE ARE SOME
DAY TO DAY FLUCTUATIONS IN TEMPERATURES...ALL OF THEM ARE STAYING
WELL ABOVE NORMAL.

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THINGS ARE GOING ABOUT AS EXPECTED. MAINLY MID LEVEL CIGS ARE OVER
THE AREA. SURFACE WINDS ARE MAINLY UNDER 20 KNOTS SO WILL KEEP THE
WIND SHEAR MENTIONED AS BEFORE. PLACES LIKE KERI AND KFDY WHICH
HAVE STRONGER SURFACE WINDS WILL NOT GET THE WIND SHEAR MENTION.
THE NEW MODELS ARE QUICKER BRINGING IN THE RAIN TODAY. HAVE SPED
THINGS UP ABOUT TWO HOURS. MVFR CIGS WILL BEGIN TO DEVELOP FROM
WEST TO EAST BEGINNING ABOUT MID MORNING. SOME IFR CIGS ARE
POSSIBLE TOWARD THE END OF THE TAF PERIOD. SOME GUSTS IN EXCESS OF
30 KNOTS ARE LIKELY ON MONDAY.

OUTLOOK...NON VFR POSSIBLE MONDAY AFTERNOON THROUGH TUESDAY
MORNING. NON VFR POSSIBLE AGAIN WEDNESDAY AND WEDNESDAY NIGHT.

.MARINE...
HAVE RAISED THE SMALL CRAFT ADVISORY FOR TONIGHT AND THROUGH
MONDAY. TONIGHTS WINDS WILL BE MARGINAL...BUT WILL CERTAINLY
INCREASE DURING THE DAY MONDAY. LOW PRESSURE WILL BE TRACKING
NORTHEAST ACROSS THE CENTRAL LAKES TONIGHT...WEAKENING
CONSIDERABLY TUESDAY WHEN IT REACHES QUEBEC. THE SOUTH-SOUTHWEST
GRADIENT REMAINS STRONG...KEEPING WINDS FAIRLY STEADY STATE
TONIGHT BETWEEN 18 AND 25 KNOTS AND INCREASING TO UPWARDS OF 30
KNOTS MONDAY. WINDS NEVER SHIFT MUCH WITH THE DISSIPATING COLD
FRONT AND HIGH PRESSURE TAKING OVER BRIEFLY TUESDAY. THE NEXT
SYSTEM CENTERED AROUND THURSDAY MORNING WILL AGAIN HAVE STIFF
WINDS. HIGH PRESSURE BUILDS ACROSS THE OHIO VALLEY
FRIDAY...MAINTAINING THE PREDOMINATE SOUTHWEST FLOW.

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 AM EST TUESDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 9 PM EST MONDAY FOR LEZ142>146.

$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...KUBINA
MARINE...OUDEMAN

AREA FORECAST DISCUSSION...UPDATED

NWS NORMAN OK

1132 PM CST SUN DEC 20 2015

.AVIATION...21/06Z TAF ISSUANCE...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD. BREEZY
SOUTH WINDS ACROSS CENTRAL OKLAHOMA WILL RELAX THROUGH THE EARLY
MORNING HOURS...GRADUALLY VEERING TO THE WEST/NORTHWEST THROUGH
SUNRISE. ACROSS WESTERN OKLAHOMA...AND INTO NORTHERN TEXAS...
SOUTHWESTERLY WINDS WILL SLOWLY VEER TO THE WEST NORTHWEST THROUGH
THE MORNING HOURS. OVERALL... WINDS WILL CALM THROUGH THE MIDDLE
OF THE PERIOD AS SURFACE HIGH PRESSURE SPREADS ACROSS THE SOUTHERN
PLAINS.

JTK

.PREV DISCUSSION... /ISSUED 636 PM CST SUN DEC 20 2015/

UPDATE...
ADJUSTED DRIZZLE/LIGHT RAIN CHANCES FOR TONIGHT.

DISCUSSION...
CURRENT WV IMAGERY REVEALS A DEVELOPING INTRUSION OF DRIER AIR OFF
THE PANHANDLES INTO NORTH/NWRN OKLAHOMA THIS EVENING. 21/00Z SFC
ANALYSIS PLACES THE SFC LOW NEAR SERN KS... WELL IN PHASE WITH THE
UPPER LOW VISIBLE ON WV. THE EXPERIMENTAL HRRR CONTINUES TO PULL
BACK PRECIP DEVELOPMENT FOR MOST OF CENTRAL OK THIS EVENING. FOR
THE PAST FEW HOURS... LIGHT SHOWERS/DRIZZLE CONTINUES TO DEVELOP
AHEAD OF THE SFC LOW OVER NERN OK/SWRN KS...ON THE FOCUS OF
DECENT ISENTROPIC ASCENT ACROSS THE ERN HALF OF OK. GIVEN THE
CURRENT PLACEMENT OF THE SFC LOW AND DEVELOPING CONDITIONS...
LIKE THE DELAYED DEVELOPMENT OF DRIZZLE/LIGHT RAIN FROM THE
EXPERIMENTAL HRRR...WHICH WILL CORRESPOND WITH INCREASING
MOISTURE AND FORCING FOR ASCENT LATER TONIGHT...WELL EAST OF I-35.
THEREFORE...TRIMMED BACK PRECIP CHANCES...KEPT LOW DRIZZLE AND
LIGHT RAIN CHANCES ALONG THE I-35 CORRIDOR...GRADUALLY TAPERING
THEMOFF TO THE EAST THROUGH THE EARLY MORNING HOURS.

JTK

PREV DISCUSSION... /ISSUED 237 PM CST SUN DEC 20 2015/

DISCUSSION...
SHORTWAVE TROUGH MOVING THROUGH THE CENTRAL AND SOUTHERN PLAINS
MAY STILL BRING A FEW SHOWERS TO PARTS OF EASTERN OKLAHOMA
TONIGHT. OTHERWISE... ALTHOUGH THE WINDS HAVE BEEN A BIT GUSTY...
HAVE NOT QUITE REACHED WIND ADVISORY ACROSS MUCH OF THE ADVISORY
AREA. WILL THEREFORE GO AHEAD AND CANCEL THE ADVISORY EARLY.
GUSTY SOUTH WINDS WILL RELAX SOME THIS EVENING BEFORE A WEAK COLD
FRONT WILL MOVE SOUTH THROUGH THE AREA WITH MUCH LIGHTER WINDS
FOR LATE TONIGHT AND MONDAY.

SHOULD SEE MORE SUN ON MONDAY... BUT TEMPS WILL BE CLOSE TO TODAY
AS SLIGHTLY COOLER AIRMASS WILL OVERSPREAD THE OKLAHOMA AND
NORTH TEXAS. SOUTH WINDS RETURN AND INCREASE FOR TUESDAY. THESE
WINDS WILL BRING MOISTURE QUICKLY BACK NORTHWARD... INTO AT LEAST
THE EASTERN HALF OF OKLAHOMA. A QUICK MOVING STORM SYSTEM WILL TRY
AND TAP INTO THIS MOISTURE PRODUCING SOME LATE DAY AND EVENING
THUNDERSTORMS ACROSS MAINLY SOUTHEAST/EASTERN OKLAHOMA. A FEW
STRONG TO PERHAPS SEVERE STORMS MAY OCCUR BEFORE THEY PUSH EAST OF
THE AREA.

ANOTHER WEAK COLD FRONT WILL THEN PUSH THROUGH WITH MAINLY
MILD/DRY WEATHER INTO THE DAY ON CHRISTMAS.

AS FOR BEYOND CHRISTMAS... STILL MUCH UNCERTAINTY REMAINS. MODELS
CONT TO FLIP FLOP BACK AND FORTH WHETHER TO CLOSE THE SYSTEM OFF
AND PRODUCE ABUNDANT PRECIP ACROSS THE SOUTHERN PLAINS OR KEEP IT
AN OPEN WAVE... WHICH PRODUCING VERY LITTLE PRECIP. NO MATTER
WHICH OCCURS... THE ONE FACTOR THAT SEEMS TO BE MORE CONSISTENT IS
THAT IT WILL BE TURNING COLDER WITH HIGHS SATURDAY AND SUNDAY
MAINLY IN THE 40S.

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 41 57 34 64 / 10 0 0 0
HOBART OK 37 57 34 64 / 0 0 0 0
WICHITA FALLS TX 43 64 36 70 / 0 0 0 0
GAGE OK 31 55 31 64 / 0 0 0 0
PONCA CITY OK 36 52 31 62 / 20 0 0 0
DURANT OK 54 67 41 68 / 20 10 0 0

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

04/03/04

AREA FORECAST DISCUSSION

NWS Tulsa OK

1120 PM CST SUN DEC 20 2015

.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
MVFR conditions prevail across eastern Oklahoma and Western
Arkansas this evening. Will some improvement in conditions at
the eastern Oklahoma TAF sites overnight with VFR conditions
expected across the whole area by Monday afternoon.

.PREV DISCUSSION... /ISSUED 802 PM CST SUN DEC 20 2015/

DISCUSSION...

Cluster of showers within the warm conveyor ahead of the southern
high Plains vort max is moving quickly east this evening. A few
locations picked up .01 of an inch. The next round of precip will
be with the wave and front...which will sweep across the region
after midnight tonight. The best rain chances will be east of
Tulsa and north of I-40. Some isolated thunder will be possible
given weak elevated instability. Pops have been removed thru
midnight west of the first round of showers.

Lacy

PREV DISCUSSION... /ISSUED 600 PM CST SUN DEC 20 2015/

UPDATE...

Adjusted pops for the evening and overnight based on radar trends
and HRRR data. See discussion below.

DISCUSSION...

Shortwave trough clearly evident in satellite imagery this
evening...centered near Springfield CO moving quickly east. Lift
in advance of the system is interacting with the tongue of low
level moisture that has nosed north into OK. This has allowed
showers to begin popping up on radar over the past hour across NE
OK. The line of showers over Osage/Pawnee counties appears to be
the back edge of the precip potential. As elevated instability
increases downstream across NE OK into NW AR later tonight...the
potential for a few lightning strikes increases. Higher pops were
brought back westward in advance of the line of showers on
radar...and adjusted after midnight per latest HRRR data. The
greater coverage ahead of the wave/front will be from I-40
northward.

Lacy

PREV DISCUSSION... /ISSUED 536 PM CST SUN DEC 20 2015/

AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
MVFR conditions will be predominate through much of Tonight and
even into Monday morning in some locations in advance of a
cold front that will move through late Tonight into Monday morning.
Conditions will improve Monday afternoon.

PREV DISCUSSION... /ISSUED 339 PM CST SUN DEC 20 2015/

DISCUSSION...
Strong low level flow in advance of the wave currently over
northern New Mexico will continue to advect moisture
northward...and as lift increases overnight...scattered convection
is expected to develop. Northern portions of the forecast area
area nearer the steeper lapse rates thus warrant a mention of
isolate thunder later tonight. The associated cold front will pass
through the area Monday morning with high pressure building across
the area yielding a dry and warm Tuesday.

The next wave begins to influence the region late Tuesday as the
moist sector expands northward Tuesday night ahead of the sfc
low...which will track into north central OK before lifting
rapidly northeastward on Wednesday. Instability will recover
sufficiently to warrant a mention of thunderstorms during this
period...however higher instability is likely further south and
east of the forecast area.

Temperatures will remain unseasonably warm especially overnight
lows within this pattern...which will continue at least into next
weekend. Thereafter the forecast continues to remain highly
uncertain regarding both timing and placement of any potential
storm system for early next week.

TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.

AVIATION...10

AREA FORECAST DISCUSSION

NWS PORTLAND OR

918 AM PST MON DEC 21 2015

.SYNOPSIS...ANOTHER VERY STRONG PACIFIC STORM SYSTEM IS EXPECTED TO
REACH THE S WA COAST THIS MORNING...AND MOVE E ACROSS SW WA TODAY
INTO EASTERN WA. THIS STORM IS EXPECTED TO PRODUCE STRONG WINDS
ACROSS MUCH 0F NORTHWEST OREGON AND FAR SOUTHERN PARTS OF SOUTHWEST
WA. SNOW IS EXPECTED IN THE CASCADES AND POSSIBLY DOWN AS LOW AS
HOOD RIVER AND PARKDALE. THE STORM MOVES EAST LATE TODAY AND TONIGHT.
ANOTHER FRONTAL SYSTEM SYSTEM WILL MOVE THROUGH TUESDAY AND
TUESDAY NIGHT. A COOLER UPPER TROUGH WILL DIG DOWN THE COAST FOR THE
LATTER PART OF THE WEEK... MAINTAINING THE UNSETTLED WEATHER PATTERN
AND DROPPING SNOW LEVELS CONSIDERABLY BY CHRISTMAS EVE DAY AND
CHRISTMAS DAY...THOUGH MOISTURE WILL BE DECREASING.
&&

.SHORT TERM...THE SURFACE LOW PRESSURE CENTER THIS MORNING IS
CURRENTLY JUST WEST OF BUOY 46089. THE BUOY AS OF AROUND 17Z MEASURED
A BAROMETRIC PRESSURE OF 981.4 MB. THIS IS A BIT STRONGER THAN THE
MODELS HAVE BEEN FORECASTING...INDICATING THE LOW PRESSURE CENTER
INTO THE UPPER 970S AS IT REACHES THE COAST. OTHERWISE...THIS SYSTEM
APPEARS TO BE TRACKING RIGHT ALONG WITH THE MODELS...CREATING HIGH
CONFIDENCE THAT IT WILL MOVE ONSHORE NEAR WILLAPA BAY LATER THIS
MORNING. WINDS HAVE STARTED INCREASING ALONG THE CENTRAL COAST AND
IN THE SOUTH AND CENTRAL WILLAMETTE VALLEY...WITH GUSTS ALREADY TO
40 TO 50 KT AS FAR NORTH AS TILLAMOOK...AND 30 TO 45 KT PEAK GUSTS
AT EUGENE...SALEM...AND AS FAR NORTH AS AURORA.

TEMPS IN THE GORGE AND CENTRAL HOOD RIVER VALLEY APPEAR TO BE STAYING
FOR THE MOST PART ABOVE FREEZING THIS MORNING...WHICH IS KEEPING SNOW
FROM ACCUMULATING BELOW 1500 FT.

NO CHANGES TO REST OF DISCUSSION. PREVIOUS DISCUSSION
FOLLOWS...SURFACE LOW WAS PASSING CLOSE TO BUOY 46005 BETWEEN 09Z AND
10Z THIS MORNING...ABOUT 300 NM W OF ABERDEEN WA. PRES ESTIMATED
AROUND 989 MB. THIS TRACKS FAIRLY WELL WITH MODELS IN
GENERAL AS FAR AS TRACK AND INTENSITY. NEWEST RUNS OF HRRR AND GFS
EARLY THIS MORNING SHOWED A TENDENCY FOR A SLIGHTLY STRONGER DEEPER
LOW THAN PREVIOUS RUNS...WITH GFS DOWN TO CLOSE TO 980 MB CENTER AS
IT MOVES ONSHORE NEAR WILLAPA BAY. OVERALL MODELS HAVE BEEN
PLEASANTLY CONSISTENT WITH THE TRACK OF THE LOW...COMING INLAND NEAR
THE LONG BEACH PENINSULA BETWEEN 18Z AND 20Z. MODELS CONTINUE TO
SHOW SURFACE LOW WEAKENING LITTLE AS IT MOVES INLAND ACROSS SW WA
TODAY. H8 WINDS TENDING TO PEAK ON THE ORDER OF 55 KT THIS MORNING
OVER NW OREGON...WHICH APPEARS TO BE A LITTLE STRONGER THAN THE
COMPARABLE SYSTEMS IN DEC 2012 AND JAN 1990. THE TRACK SUGGESTS THE
NORTHERN PART OF THE S WA COAST ZONE AND WILLAPA HILLS MAY BE SPARED
THE WINDS. THE FAST MOVEMENT OF THE LOW INFERS STRONG PRES RISES
MOVING IN BEHIND...SO MUCH OF THE REST OF THE AREA LOOKS ON TRACK
FOR THE EXPECTED WINDS. CASCADES MAY BE A LITTLE QUESTIONABLE FOR
HITTING THEIR HIGH WIND CRITERIA GIVEN FREE AIR H7 WINDS PEAKING
AROUND 65 TO 70 KT. OVERALL PREFER TO STICK WITH THE CURRENT WIND
WARNINGS AS THEY ARE NOW.

TEMPS IN THE GORGE AND HOOD RIVER VALLEY STARTING OUT A FEW DEGREES
ABOVE FREEZING EARLY THIS MORNING. NAM BUFR SOUNDINGS DO HOWEVER
SHOW SOME COOLING AS HEAVIER PRECIPITATION ARRIVES AFTER 14Z...
BEFORE WARMING KICKS IN AGAIN AFTER 18Z. WILL DOWNGRADE THE WINTER
STORM WARNING THERE TO AN ADVISORY DUE TO MARGINAL TEMPS AND
EXPECTED SHORT DURATION OF SNOW. PRECIPITATION SHIELD AHEAD OF THE
WARM FRONT THIS MORNING WILL BRING HIGH POPS THIS MORNING...BUT
DRIER WESTERLY FLOW IS FORCED IN QUICKLY TODAY...TRENDING THE
PRECIPITATION TOWARDS MORE OROGRAPHICALLY DRIVEN SHOWERS IN THE
AFTERNOON AND EVENING. WITH THE OROGRAPHIC LIFT CONTINUING INTO THE
EVENING...WILL CONTINUE WITH A LOW END WINTER STORM WARNING FOR THE
CASCADES TODAY THROUGH THIS EVENING. THE SNOW SHOWERS FOR THE
CASCADES WILL EASE UP OVERNIGHT AS ONSHORE FLOW WEAKENS. SNOW LEVELS
MAY DIP DOWN BELOW 2500 FEET IN THE HEAVIER PRECIPITATION THIS
MORNING AHEAD OF THE WARM FRONT...SO WILL KEEP THE ADVISORY FOR SNOW
GOING THROUGH THE MORNING.

TUE AND WED A COUPLE MORE SHORTWAVES EMBEDDED IN A VERY FAST
WESTERLY FLOW ALOFT MOVE ACROSS THE REGION. A 160 KT 300 MB JET OVER
NW OREGON TUE SINKS S TOWARDS THE CA BORDER WED. THIS SETS UP A
PATTERN FAVORABLE FOR SNOW IN THE CASCADES TUE AND WED...WITH SNOW
LEVELS LOWERING TO THE CASCADE FOOTHILLS AND HIGHER COAST RANGE.
-MCCOY/DE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...WEDNESDAY
NIGHT THROUGH SUNDAY...UPPER-LEVEL TROUGH DIGGING SOUTHWARD OVER THE
WESTERN CONUS WILL KEEP SHOWERS IN THE FORECAST WEDNESDAY NIGHT
THROUGH THURSDAY. SNOW LEVELS WILL BE DROPPING THURSDAY INTO THURSDAY
NIGHT TO 1000 TO 1500 FEET IN THE SOUTHERN HALF OF OUR AREA...BUT
SNOW LEVELS COULD DROP AS LOW AS 500 TO 1000 FT IN THE NORTHERN HALF
OF OUR AREA. SHOWERS WILL BE STARTING TO TAPER OFF LATE THURSDAY INTO
EARLY FRIDAY. WITH SNOW LEVELS GETTING SO LOW IN THE NORTHERN
WILLAMETTE VALLEY...WE COULD SEE A FEW SNOWFLAKES MIX IN WITH RAIN
SHOWERS ALL THE WAY DOWN TO THE VALLEY FLOOR LATE THURSDAY INTO EARLY
FRIDAY. WE LIKELY WILL NOT SEE ANY ACCUMULATION EXCEPT AT ELEVATIONS
ABOVE 500 FT. BY MIDDAY FRIDAY...RIDGING WILL BUILD HIGH PRESSURE
OVER THE AREA CUTTING OFF ANY CHANCE FOR PRECIPITATION THROUGH FRIDAY
NIGHT EXCEPT FOR A SLIGHT CHANCE OF FLURRIES IN THE CASCADES.

OUR NEXT SYSTEM BRINGS MORE PRECIPITATION ON SATURDAY INTO SUNDAY.
SNOW LEVELS COME BACK UP TO AROUND 3000-4000 FT WITH THIS
SYSTEM...BUT COLD AIR TRAPPED IN THE HOOD RIVER VALLEY AND CENTRAL
GORGE COULD MEAN A WINTRY MIX IN THESE LOWER AREAS. -MCCOY
&&

.AVIATION...A WARM FRONT MOVING THROUGH THE REGION IS BRINGING
RAIN AND PREDOMINANTLY MVFR CONDITIONS THIS MORNING. THERE ARE
POCKETS OF IFR CONDITIONS IN HEAVIER BANDS OF RAIN. SOUTH TO
SOUTHWEST WINDS TO INCREASE THROUGH THE MORNING BEHIND THE WARM
FRONT...WHICH SHOULD LIFT CIGS TO MAINLY VFR INTO TONIGHT ACROSS
THE AREA. WIND GUSTS OF SOUTH TO SOUTHWEST AT 50 TO 60 KT APPEAR
LIKELY FOR COASTAL TAF SITES THROUGH ABOUT 19Z MORNING...AND 40
TO 50 KT IN THE WILLAMETTE VALLEY THROUGH ABOUT 21Z. THE STRONGEST
WINDS SHOULD ONLY A COUPLE HOURS WITH LATEST MODEL GUIDANCE
SUGGEST THE STRONGEST WINDS INLAND MAY OCCUR AROUND KHIO...KMMV
AND KUAO. WINDS WILL SHIFT TO WESTERLY AS THE LOW PRES PUSHES
THROUGH THE REGION THIS AFTERNOON.

KPDX AND APPROACHES...BREEZY EAST WINDS AND MVFR CONDITIONS THIS
MORNING BEFORE STRONG SOUTHWEST WINDS DEVELOP AROUND MIDDAY AND
CONDITIONS TURN MAINLY VFR FOR THIS AFTERNOON AND EVENING. A 1 TO
3 HOUR PERIOD OF SOUTH TO SOUTHWEST WIND GUSTS OF 40 TO 50 KT
APPEAR LIKELY TO DEVELOP BETWEEN 19Z AND 22Z MONDAY. PYLE/NEUMAN
&&

.MARINE...A LOW PRES CENTER CURRENTLY LOCATED JUST NORTH OF BUOY
46089 WILL MOVE QUICKLY ONSHORE THIS MORNING ALONG THE LONG BEACH
PENINSULA. GALE FORCE SOUTHERLY WINDS OCCURRING OVER THE WATERS
THIS MORNING WITH A LEADING WARM FRONT. A STRONGER BURST OF
WESTERLY WINDS WILL OCCUR JUST TO THE SOUTH OF THE LOW AS IT
TRACKS EASTWARD ACROSS OUR NORTHERN WATERS THIS MORNING. AS A
RESULT...WIND GUSTS OF 45 TO 55 KT APPEAR LIKELY ACROSS OUR WATERS
THROUGH MIDDAY. THIS WILL LIKELY RESULT IN SEAS BUILDING ABRUPTLY
AND TOPPING OUT IN AT LEAST THE 20 TO 25 FT RANGE MIDDAY/EARLY
AFTERNOON. GIVEN THE FAST MOVING NATURE OF THIS STORM SYSTEM SEAS
SHOULD SETTLE BACK DOWN INTO THE MID TO UPPER TEENS FAIRLY QUICKLY
LATER THIS EVENING.

ANOTHER STORM SYSTEM APPEARS TO BRING GUSTY WEST-NORTHWEST WINDS
OF 35 TO 40 KT TUESDAY AND TUESDAY NIGHT. A WESTERLY SWELL LIKELY
IN EXCESS OF 20 FT WILL LIKELY PUSH INTO THE WATERS DURING THIS
TIME AND LINGER THROUGH MUCH OF WEDNESDAY. COASTAL FLOODING AND/OR
HIGH SURF ISSUES IN SOME SHAPE OR FORM APPEAR LIKELY ALONG OUR
COAST AS A RESULT.

UNSETTLED WEATHER WILL CONTINUE TO KEEP SEAS ABOVE 10 FT WITH
OCCASIONAL BOUTS OF 20 TO 35 KT WINDS THROUGH THURSDAY BEFORE HIGH
PRESSURE BUILDS TEMPORARILY INTO THE PACIFIC NORTHWEST AROUND
FRIDAY/SATURDAY. IT STILL APPEARS SEAS MAY DROP BELOW 10 FT FOR
12-36 PERIOD DURING THIS TIME BEFORE ANOTHER STORM SYSTEM MOVES
INTO THE REGION LATE IN THE WEEKEND. PYLE/NEUMAN
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR CENTRAL
COLUMBIA RIVER GORGE-NORTHERN OREGON CASCADES-UPPER HOOD
RIVER VALLEY.

WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY.

HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR GREATER
PORTLAND METRO AREA-LOWER COLUMBIA-WESTERN COLUMBIA RIVER
GORGE.

HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR CENTRAL
WILLAMETTE VALLEY-NORTHERN OREGON CASCADE FOOTHILLS-SOUTH
WILLAMETTE VALLEY.

WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR NORTHERN OREGON

CASCADE FOOTHILLS.

WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CASCADES
IN LANE COUNTY-NORTHERN OREGON CASCADES.

HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR CENTRAL
COAST RANGE OF WESTERN OREGON-COAST RANGE OF NORTHWEST
OREGON.

HIGH WIND WARNING UNTIL 2 PM PST THIS AFTERNOON FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR CENTRAL
COLUMBIA RIVER GORGE-SOUTH WASHINGTON CASCADES.

WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE.

HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR GREATER
VANCOUVER AREA-I-5 CORRIDOR IN COWLITZ COUNTY-SOUTH
WASHINGTON CASCADE FOOTHILLS-WESTERN COLUMBIA RIVER GORGE.

HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR SOUTH
WASHINGTON COAST-WILLAPA HILLS.

WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR SOUTH
WASHINGTON CASCADE FOOTHILLS.

WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR SOUTH
WASHINGTON CASCADES.

PZ...STORM WARNING UNTIL 2 PM PST THIS AFTERNOON FOR COASTAL WATERS
FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 AM PST
TUESDAY.

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING FROM 11 AM THIS MORNING TO 7 PM PST THIS
EVENING FOR CENTRAL COLUMBIA RIVER GORGE-NORTHERN OREGON
CASCADES-UPPER HOOD RIVER VALLEY.

WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY.

HIGH WIND WARNING FROM 10 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR GREATER PORTLAND METRO AREA-LOWER COLUMBIA-
WESTERN COLUMBIA RIVER GORGE.

HIGH WIND WARNING FROM 9 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR CENTRAL WILLAMETTE VALLEY-NORTHERN OREGON
CASCADE FOOTHILLS-SOUTH WILLAMETTE VALLEY.

WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR NORTHERN OREGON

CASCADE FOOTHILLS.

WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR NORTHERN
OREGON CASCADES.

WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CASCADES
IN LANE COUNTY.

HIGH WIND WARNING FROM 8 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR CENTRAL COAST RANGE OF WESTERN OREGON-COAST
RANGE OF NORTHWEST OREGON.

HIGH WIND WARNING UNTIL 2 PM PST THIS AFTERNOON FOR CENTRAL
OREGON COAST.

HIGH WIND WARNING FROM 7 AM THIS MORNING TO 2 PM PST THIS
AFTERNOON FOR NORTH OREGON COAST.

WA...HIGH WIND WARNING FROM 11 AM THIS MORNING TO 7 PM PST THIS
EVENING FOR CENTRAL COLUMBIA RIVER GORGE-SOUTH WASHINGTON
CASCADES.

WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE.

HIGH WIND WARNING FROM 10 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR GREATER VANCOUVER AREA-I-5 CORRIDOR IN
COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS-WESTERN
COLUMBIA RIVER GORGE.

HIGH WIND WARNING FROM 9 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR SOUTH WASHINGTON COAST-WILLAPA HILLS.

WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR SOUTH
WASHINGTON CASCADE FOOTHILLS.

WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR SOUTH
WASHINGTON CASCADES.

PZ...STORM WARNING UNTIL 2 PM PST THIS AFTERNOON FOR COASTAL WATERS
FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
4 AM PST TUESDAY.

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.

AREA FORECAST DISCUSSION

NWS PORTLAND OR

310 AM PST MON DEC 21 2015

.SYNOPSIS...ANOTHER VERY STRONG PACIFIC STORM SYSTEM IS EXPECTED TO
REACH THE S WA COAST THIS MORNING...AND MOVE E ACROSS SW WA TODAY
INTO EASTERN WA. THIS STORM IS EXPECTED TO PRODUCE STRONG WINDS
ACROSS MUCH 0F NORTHWEST OREGON AND FAR SOUTHERN PARTS OF SOUTHWEST
WA. SNOW IS EXPECTED IN THE CASCADES AND POSSIBLY DOWN AS LOW AS
HOOD RIVER AND PARKDALE. THE STORM MOVES EAST LATE MONDAY AND MONDAY
NIGHT. ANOTHER FRONTAL SYSTEM SYSTEM WILL MOVE THROUGH TUESDAY AND
TUESDAY NIGHT. A COOLER UPPER TROUGH WILL DIG DOWN THE COAST FOR THE
LATTER PART OF THE WEEK... MAINTAINING THE UNSETTLED WEATHER PATTERN
AND DROPPING SNOW LEVELS CONSIDERABLY BY CHRISTMAS EVE DAY AND
CHRISTMAS DAY...THOUGH MOISTURE WILL BE DECREASING.
&&

.SHORT TERM...SURFACE LOW WAS PASSING CLOSE TO BUOY 46005 BETWEEN
09Z AND 10Z THIS MORNING...ABOUT 300 NM W OF ABERDEEN WA. PRES
ESTIMATED AROUND 989 MB. THIS TRACKS FAIRLY WELL WITH MODELS IN
GENERAL AS FAR AS TRACK AND INTENSITY. NEWST RUNS OF HRRR AND GFS
EARLY THIS MORNING SHOWED A TENDENCY FOR A SLIGHTLY STRONGER DEEPER
LOW THAN PREVIOUS RUNS...WITH GFS DOWN TO CLOSE TO 980 MB CENTER AS
IT MOVES ONSHORE NEAR WILLAPA BAY. OVERALL MODELS HAVE BEEN
PLEASANTLY CONSISTENT WITH THE TRACK OF THE LOW...COMING INLAND NEAR
THE LONG BEACH PENINSULA BETWEEN 18Z AND 20Z. MODELS CONTINUE TO
SHOW SURFACE LOW WEAKENING LITTLE AS IT MOVES INLAND ACROSS SW WA
TODAY. H8 WINDS TENDING TO PEAK ON THE ORDER OF 55 KT THIS MORNING
OVER NW OREGON...WHICH APPEARS TO BE A LITTLE STRONGER THAN THE
COMPARABLE SYSTEMS IN DEC 2012 AND JAN 1990. THE STRACK SUGGESTS THE
NORTHERN PART OF THE S WA COAST ZONE AND WILLAPA HILLS MAY BE SPARED
THE WINDS. THE FAST MOVEMENT OF THE LOW INFERS STRONG PRES RISES
MOVING IN BEHIND...SO MUCH OF THE REST OF THE AREA LOOKS ON TRACK
FOR THE EXPECTED WINDS. CASCADES MAY BE A LITTLE QUESTIONABLE FOR
HITTING THEIR HIGH WIND CRITERIA GIVEN FREE AIR H7 WINDS PEAKING
AROUND 65 TO 70 KT. OVERALL PREFER TO STICK WITH THE CURRENT WIND
WARNINGS AS THEY ARE NOW.

TEMPS IN THE GORGE AND HOOD RIVER VALLEY STARTING OUT A FEW DEGREES
ABOVE FREEZING EARLY THIS MORNING. NAM BUFR SOUNDINGS DO HOWEVER
SHOW SOME COOLING AS HEAVIER PRECIPITATION ARRIVES AFTER 14Z...
BEFORE WARMING KICKS IN AGAIN AFTER 18Z. WILL DOWNGRADE THE WINTER
STORM WARNING THERE TO AN ADVISORY DUE TO MARGINAL TEMPS AND
EXPECTED SHORT DURATION OF SNOW. PRECIPITATION SHIELD AHEAD OF THE
WARM FRONT THIS MORNING WILL BRING HIGH POPS THIS MONRNING...BUT
DRIER WESTERLY FLOW IS FORCED IN QUICKLY TODAY...TRENDING THE
PRECIPITATION TOWARDS MORE OROGRAPHICALLY DRIVEN SHOWERS IN THE
AFTERNOON AND EVENING. WITH THE OROGRAPHIC LIFT CONTINUING INTO THE
EVENING...WILL CONTINUE WITH A LOW END WINTER STORM WARNING FOR THE
CASCADES TODAY THROUGH THIS EVENING. THE SNOW SHOWERS FOR THE
CASCADES WILL EASE UP OVERNIGHT AS ONSHORE FLOW WEAKEND. SNOW LEVELS
MAY DIP DOWN BELOW 2500 FEET IN THE HEAVIER PRECIPITATION THIS
MORNING AHEAD OF THE WARM FRONT...SO WILL KEEP THE ADVISORY FOR SNOW
GOING THROUGH THE MORNING.

.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...UPPER-LEVEL TROUGH
DIGGING SOUTHWARD OVER THE WESTERN CONUS WILL KEEP SHOWERS IN THE
FORECAST WEDNESDAY NIGHT THROUGH THURSDAY. SNOW LEVELS WILL BE
DROPPING THURSDAY INTO THURSDAY NIGHT TO 1000 TO 1500 FEET IN THE
SOUTHERN HALF OF OUR AREA...BUT SNOW LEVELS COULD DROP AS LOW AS 500
TO 1000 FT IN THE NORTHERN HALF OF OUR AREA. SHOWERS WILL BE STARTING
TO TAPER OFF LATE THURSDAY INTO EARLY FRIDAY. WITH SNOW LEVELS
GETTING SO LOW IN THE NORTHERN WILLAMETTE VALLEY...WE COULD SEE A FEW
SNOWFLAKES MIX IN WITH RAIN SHOWERS ALL THE WAY DOWN TO THE VALLEY
FLOOR LATE THURSDAY INTO EARLY FRIDAY. WE LIKELY WILL NOT SEE ANY
ACCUMULATION EXCEPT AT ELEVATIONS ABOVE 500 FT. BY MIDDAY
FRIDAY...RIDGING WILL BUILD HIGH PRESSURE OVER THE AREA CUTTING OFF
ANY CHANCE FOR PRECIPITATION THROUGH FRIDAY NIGHT EXCEPT FOR A SLIGHT
CHANCE OF FLURRIES IN THE CASCADES.

.AVIATION...A WARM FRONT WILL LIFT NORTHEASTWARD ACROSS THE AREA
THIS MORNING BRINGING WIDESPREAD MVFR CONDITIONS EARLY THIS
MORNING WITH PERHAPS A BRIEF PERIOD OR TWO OF IFR CONDITIONS AT A
FEW TAF SITES. STRONG SOUTH TO SOUTHWEST WINDS WILL THEN SPREAD
INTO THE REGION AS THE LOWER ATMOSPHERE DESTABILIZES. THIS SHOULD
PRODUCE MAINLY VFR CONDITIONS INTO TONIGHT ACROSS THE AREA...BUT
WIND GUSTS OF SOUTH TO SOUTHWEST WIND GUSTS OF 50 TO 60 KT APPEAR
LIKELY FOR COASTAL TAF SITES THIS MORNING...AND 40 TO 50 KT IN THE
WILLAMETTE VALLEY AROUND 20Z. THE STRONGEST WINDS SHOULD ONLY
LAST 1 TO 3 HOURS WITH LATEST MODEL GUIDANCE SUGGEST THE STRONGEST
WINDS MAY OCCUR AROUND KHIO...KMMV AND KUAO.

KPDX AND APPROACHES...INCREASING EAST WINDS AND MVFR CONDITIONS
WILL LIKELY ACCOMPANY A WARM FRONT THIS MORNING BEFORE STRONG
SOUTHWEST WINDS DEVELOP AND CONDITIONS TURN MAINLY VFR THIS
AFTERNOON AND EVENING. A 1 TO 3 HOUR PERIOD OF SOUTH TO SOUTHWEST
WIND GUSTS OF 40 TO 50 KT APPEAR LIKELY TO DEVELOP BETWEEN 19Z AND
22Z MONDAY. /NEUMAN
&&

.MARINE...A DEVELOPING LOW PRESSURE CURRENTLY JUST EAST-NORTHEAST
OF BUOY 46005...NEAR 130W...WILL MOVE EASTWARD INTO SOUTH
WASHINGTON COAST MIDDAY. STRONG SOUTH...AND THEN WEST WINDS WILL
DEVELOP SOUTH OF THE LOW PRESSURE AS IT TRACKS EASTWARD ACROSS OUR
NORTHERN WATERS THIS MORNING. AS A RESULT...WIND GUSTS OF 45 TO 55
KT APPEAR LIKELY ACROSS OUR WATERS THROUGH MIDDAY. THIS WILL
LIKELY RESULT IN SEAS BUILDING ABRUPTLY AND TOPPING OUT IN AT
LEAST THE 20 TO 25 FT RANGE MIDDAY/EARLY AFTERNOON. GIVEN THE FAST
MOVING NATURE OF THIS STORM SYSTEM SEAS SHOULD SETTLE BACK DOWN
INTO THE MID TO UPPER TEENS FAIRLY QUICKLY LATE THIS AFTERNOON OR
EARLY THIS EVENING.

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING FROM 11 AM THIS MORNING TO 7 PM PST THIS
EVENING FOR CENTRAL COLUMBIA RIVER GORGE-NORTHERN OREGON
CASCADES-UPPER HOOD RIVER VALLEY.

WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COLUMBIA RIVER GORGE-UPPER HOOD RIVER VALLEY.

HIGH WIND WARNING FROM 10 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR GREATER PORTLAND METRO AREA-LOWER COLUMBIA-
WESTERN COLUMBIA RIVER GORGE.

HIGH WIND WARNING FROM 9 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR CENTRAL WILLAMETTE VALLEY-NORTHERN OREGON
CASCADE FOOTHILLS-SOUTH WILLAMETTE VALLEY.

WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR NORTHERN OREGON
CASCADE FOOTHILLS.