Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 12/14/11
AREA FORECAST DISCUSSION...UPDATED
NWS TALLAHASSEE FL
945 AM EST Mon Dec 12 2011
.UPDATE...Latest RUC analysis shows most of the shortwave energy has
moved east of the CWA along with the bulk of the rainfall. Other
than patches of very light rain, there was only a scattering of
showers over the southeast Big Bend and coastal waters. Patchy light
rain or drizzle may remain possible into the afternoon but will
update grids and zones shortly to trim back PoPs based on radar
coverage. Abundant low level moisture will remain in place today and
the low cloudiness extends through most of Mississippi and spreading
to the west. The clouds will keep max temperatures today below
seasonal levels for all but Dixie county where low 70s are forecast.
&&
.MARINE (Today through Friday)...
High pressure over the Mid-Atlantic states will slowly weaken over
the next several days with conditions gradually improving over the
coastal waters. Winds and seas have diminished to exercise caution
levels this morning and the headline for today will be maintained.
Winds and seas will remain elevated at caution levels, especially
away from the coast through Wednesday before the gradient breaks
down and winds drop below 10 knots for the end of the week.
&&
.AVIATION...(Through 12z Tuesday)...
This set of TAFs remains very similar to the previous set. In
general, ceilings were either in the low end of the MVFR range, or
down into IFR, at TAF issuance time. Ensemble probabilities and MOS
guidance all suggest a prevailing IFR stratus ceiling for most of
the day, with some periods of LIFR possible tonight. Given the
rainfall over the past 12 hours adding a bit more moisture to the
surface, it`s also possible we will see some light fog at the
various terminals after 00z Tuesday, with the best chances being at
TLH and VLD (where winds are likely to be lightest).
&&
.HYDROLOGY...A few corridors of heavy rain overnight prompted the
issuance of several Flood Advisories, the last of which is scheduled
to expire at 7am EST. The Tallahassee area was directly impacted by
one area of heavy rain, with widespread 3 to 5 inch totals across
various parts of the city (heaviest totals generally south and
west). The airport ASOS (KTLH) picked up 3.57 inches through 5:50am
EST, and this is the highest 2-day rainfall total measured at
Tallahassee since January 20-21, 2010. Flooding issues around the
city were mainly related to some minor urban flooding and some
shallow water over a few roads. Another corridor of heavy rain
developed from NC Taylor County into C Madison County, FL. The KTLH
radar estimated 4 to 7.5 inches of rain in a narrow band in this
area, and radar rainfall estimates were pretty reliable overnight
based on observed rainfall. This is also similar to the Q2 estimates
(4-6 inches).
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 62 51 70 49 72 / 60 20 10 0 0
Panama City 61 50 67 50 68 / 40 10 0 0 0
Dothan 54 47 67 48 72 / 50 20 10 0 0
Albany 54 47 66 45 71 / 70 20 10 0 0
Valdosta 61 51 70 49 74 / 70 20 10 0 0
Cross City 73 53 73 50 75 / 60 20 10 0 0
Apalachicola 63 52 69 54 68 / 40 10 10 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
UPDATE...Barry
MARINE...Wool
AVIATION...Barry/Lamers
HYDROLOGY...Camp/Lamers
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
112 PM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL AT THE SURFACE THROUGH THE
MIDDLE OF THE WEEK. ONSHORE LOW LEVEL FLOW AND WARM ADVECTION
PROVIDE INCREASED CHANCES OF LIGHT RAIN TODAY ALONG WITH COOLER
TEMPERATURES. UPPER LEVEL RIDGING WILL BRING WARMING TEMPERATURES
MID WEEK WITH A FRONTAL BOUNDARY EXPECTED TO PUSH INTO THE REGION
LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR TRENDS SHOW THE BULK OF THE RAIN MOVING NORTHEAST SOUTHEAST
OF A WILLISTON TO LYNCHBURG LINE. ONLY WIDELY SCATTERED SHOWERS
ARE PRESENT ON RADAR ACROSS EAST CENTRAL GEORGIA AND CENTRAL SOUTH
CAROLINA AS THE SHORTWAVE WORKS ITS WAY ACROSS SOUTH CAROLINA. AS A
RESULT...MOVED PRECIPITATION NORTHEAST AND OUT OF THE AREA BY 00Z
THIS EVENING. LOW CLOUDS WILL CONTINUE ACROSS MUCH OF THE
AREA...EXCEPT FAR NORTH WHERE THERE ARE SOME BREAKS IN THE LOW
CLOUDS THIS AFTERNOON. NO OTHER CHANGES WERE MADE..
UPDATED FORECAST 10 AM EST...TEMPERATURES RUNNING COOLER THAN
FORECAST SO LOWERED MAXIMUM TEMPS INTO THE UPPER 40S SOUTHWEST TO
CENTRAL AND LOWER 50S NORTHEAST...WHERE CHANCES OF PRECIPITATION
IS LESS AND CLOUD COVER THINNER. RAIN COOLED AIR AND A DRY
NORTHEAST FLOW WILL IMPEDE TEMPERATURE RISES. THE REST OF THE
FORECAST WAS LEFT UNCHANGED. PRECIPITATION FORECAST IS EXCELLENT
IN DEPICTING EXTEND AND MOVEMENT OF THE RAINFALL SHIELD WHICH
COVERS THE SOUTHERN HALF OF THE FORECAST AREA.
SHORT WAVE CAUSING THIS ACTIVITY IS NOW IN SOUTHWEST SOUTH
CAROLINA AS DEPICTED BY THE WATER VAPOR SATELLITE LOOP. RUC MODEL
TOO FAST...WENT WITH THE SLOWER NAM MODEL, CLOUDS SHOULD BEGIN
LIFTING LATER THIS AFTERNOON AND THE RAIN WILL END FROM THE
SOUTHWEST AS THE SHORT WAVE LIFTS NORTHEAST TAKING THE ISENTROPIC
LIFT WITH IT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
A BUILDING UPPER RIDGE SETS UP OVER THE FORECAST AREA TUESDAY
INTO WEDNESDAY IN RESPONSE TO A DEEP UPSTREAM TROUGH EJECTING FROM
THE DESERT SOUTHWEST. THIS WILL BRING SOME WEAK DOWNSLOPING FLOW
OFF THE MOUNTAINS AND HELP ERODE THE CLOUDS AND ALLOW FOR A
WARMING TREND THROUGH MID WEEK. TEMPERATURES SHOULD CLIMB ABOVE
NORMAL WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO LOWER
40S WITH NO CHANCE FOR PRECIPITATION.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
NO LARGE CHANGES TO THE EXTENDED FORECAST. INCREASING CONFIDENCE
REGARDING THE PASSAGE OF A COLD FRONT THROUGH THE FORECAST AREA
LATE WEEK. LATEST GFS AND ECMWF BOTH SHOWING SHORTWAVE ENERGY
LIFTING THROUGH THE GREAT LAKES REGION AND DEVELOPING WESTERLY
ZONAL FLOW BEHIND THE SHORTWAVE WHICH PUSHES THE FRONT NEAR THE
FORECAST AREA ON FRIDAY AND LIKELY STALLS OR SLOWLY PUSHES THROUGH
THE REGION. DELAYED THE ONSET OF POPS TO THURSDAY NIGHT AND FRIDAY
AND GOING WITH A DRY FORECAST ON THURSDAY AND WARMER TEMPERATURES
AHEAD OF THE FRONT. TEMPERATURES FALL BACK TO NORMAL OVER THE
WEEKEND WITH THE FRONT NEARBY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL CONTINUE BUILDING IN ACROSS THE AREA OVER THE
NEXT 24 HOURS. SHORT WAVE WHICH BROUGHT THE RAIN IS NOW OVER
CENTRAL SOUTH CAROLINA AND MOVING EAST. MVFR CEILINGS COVER SOUTH
CAROLINA AND EAST CENTRAL GEORGIA WITH IFR CONDITIONS IN SOUTHEAST
GEORGIA. TRENDS INDICATE THAT THE CLOUDINESS IS ERODING FROM THE
NORTH AS THE HIGH BUILDS IN. MODEL GUIDANCE SHOW ONE MORE VERY
WEAK SHORT WAVE OVER THE TENNESSEE VALLEY. THIS MAY REINFORCE THE
CLOUD COVER LATER THIS AFTERNOON. THE HIGH WILL CONTINUE
STRENGTHENING AS RIDGE BUILDS INTO THE AREA FROM THE WEST TONIGHT.
WITH LOW CLOUDINESS EXTENDING ACROSS MUCH OF THE AREA THIS
AFTERNOON...KEPT MVFR CEILINGS THROUGH THE REST OF THE
DAY...FAVORING THE 17Z GFS LAMP GUIDANCE. VFR CEILINGS WILL RETURN
ACROSS THE ENTIRE AREA BETWEEN 23Z AND 00Z THIS EVENING.
WITH CLEARING SKIES LATER TONIGHT...EXPECT SOME FOG DEVELOPMENT
IN AREAS WHERE THERE WAS RAIN...AGS...OGB.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTED EXPECTED AT THIS
TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1148 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL AT THE SURFACE THROUGH THE
MIDDLE OF THE WEEK. ONSHORE LOW LEVEL FLOW AND WARM ADVECTION
PROVIDE INCREASED CHANCES OF LIGHT RAIN TODAY ALONG WITH COOLER
TEMPERATURES. UPPER LEVEL RIDGING WILL BRING WARMING TEMPERATURES
MID WEEK WITH A FRONTAL BOUNDARY EXPECTED TO PUSH INTO THE REGION
LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR TRENDS SHOW THE BULK OF THE RAIN MOVING NORTHEAST SOUTHEAST
OF A WILLISTON TO LYNCHBURG LINE. ONLY WIDELY SCATTERED SHOWERS
ARE PRESENT ON RADAR ACROSS EAST CENTRAL GEORGIA AND CENTRAL SOUTH
CAROLINA AS THE SHORTWAVE WORKS ITS WAY ACROSS SOUTH CAROLINA. AS A
RESULT...MOVED PRECIPITATION NORTHEAST AND OUT OF THE AREA BY 00Z
THIS EVENING. LOW CLOUDS WILL CONTINUE ACROSS MUCH OF THE
AREA...EXCEPT FAR NORTH WHERE THERE ARE SOME BREAKS IN THE LOW
CLOUDS THIS AFTERNOON. NO OTHER CHANGES WERE MADE..
UPDATED FORECAST 10 AM EST...TEMPERATURES RUNNING COOLER THAN
FORECAST SO LOWERED MAXIMUM TEMPS INTO THE UPPER 40S SOUTHWEST TO
CENTRAL AND LOWER 50S NORTHEAST...WHERE CHANCES OF PRECIPITATION
IS LESS AND CLOUD COVER THINNER. RAIN COOLED AIR AND A DRY
NORTHEAST FLOW WILL IMPEDE TEMPERATURE RISES. THE REST OF THE
FORECAST WAS LEFT UNCHANGED. PRECIPITATION FORECAST IS EXCELLENT
IN DEPICTING EXTEND AND MOVEMENT OF THE RAINFALL SHIELD WHICH
COVERS THE SOUTHERN HALF OF THE FORECAST AREA.
SHORT WAVE CAUSING THIS ACTIVITY IS NOW IN SOUTHWEST SOUTH
CAROLINA AS DEPICTED BY THE WATER VAPOR SATELLITE LOOP. RUC MODEL
TOO FAST...WENT WITH THE SLOWER NAM MODEL, CLOUDS SHOULD BEGIN
LIFTING LATER THIS AFTERNOON AND THE RAIN WILL END FROM THE
SOUTHWEST AS THE SHORT WAVE LIFTS NORTHEAST TAKING THE ISENTROPIC
LIFT WITH IT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
A BUILDING UPPER RIDGE SETS UP OVER THE FORECAST AREA TUESDAY
INTO WEDNESDAY IN RESPONSE TO A DEEP UPSTREAM TROUGH EJECTING FROM
THE DESERT SOUTHWEST. THIS WILL BRING SOME WEAK DOWNSLOPING FLOW
OFF THE MOUNTAINS AND HELP ERODE THE CLOUDS AND ALLOW FOR A
WARMING TREND THROUGH MID WEEK. TEMPERATURES SHOULD CLIMB ABOVE
NORMAL WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO LOWER
40S WITH NO CHANCE FOR PRECIPITATION.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
NO LARGE CHANGES TO THE EXTENDED FORECAST. INCREASING CONFIDENCE
REGARDING THE PASSAGE OF A COLD FRONT THROUGH THE FORECAST AREA
LATE WEEK. LATEST GFS AND ECMWF BOTH SHOWING SHORTWAVE ENERGY
LIFTING THROUGH THE GREAT LAKES REGION AND DEVELOPING WESTERLY
ZONAL FLOW BEHIND THE SHORTWAVE WHICH PUSHES THE FRONT NEAR THE
FORECAST AREA ON FRIDAY AND LIKELY STALLS OR SLOWLY PUSHES THROUGH
THE REGION. DELAYED THE ONSET OF POPS TO THURSDAY NIGHT AND FRIDAY
AND GOING WITH A DRY FORECAST ON THURSDAY AND WARMER TEMPERATURES
AHEAD OF THE FRONT. TEMPERATURES FALL BACK TO NORMAL OVER THE
WEEKEND WITH THE FRONT NEARBY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
CEILINGS LIFTING OVER THE NORTHERN TERMINALS...STAYING THE SAME OR
LOWERING OVER AGS...DNL...OGB. WEAK ISENTROPIC LIFT ASSOCIATED
WITH SHORTWAVE CURRENTLY OVER WESTERN SOUTH CAROLINA WILL SHIFT
EAST BY THIS EVENING...12 Z NAM AND 06Z GFS ARE IN AGREEMENT IN ENDING
ISENTROPIC LIFT BY TONIGHT. IMPROVED CONDITIONS TO VFR AT BOTH CAE
AND CUB WITH THE BULK OF THE PRECIPITATION EXPECTED TO REMAIN
SOUTH OF THESE LOCATIONS.
LOWERED CEILING AT OGB WHERE WITH THE BEST CHANCE OF RAIN IS AND
KEPT THE FORECAST THE SAME AT AGS AND DNL. MADE MINOR CHANGES TO
THE WIND FORECAST. IN ALL LOCATIONS..HOWEVER NORTHEAST WINDS ARE EXPECTED
THROUGH THE REMAINDER OF THIS AFTERNOON. REST LEFT UNCHANGED FOR
NOW. LOW CEILINGS EXTEND BACK INTO WESTERN ALABAMA. WITH THE LACK
OF A STRONG COLD FRONT TO SCOUR OUT THE MOISTURE...MVFR TO IFR
CEILINGS MAY COME BACK ACROSS THE REGION THIS EVENING. THIS WILL
BE MORE CLOSELY LOOKED AT WITH LATER MODEL RUNS.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1013 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL AT THE SURFACE THROUGH THE
MIDDLE OF THE WEEK. ONSHORE LOW LEVEL FLOW AND WARM ADVECTION
PROVIDE INCREASED CHANCES OF LIGHT RAIN TODAY ALONG WITH COOLER
TEMPERATURES. UPPER LEVEL RIDGING WILL BRING WARMING TEMPERATURES
MID WEEK WITH A FRONTAL BOUNDARY EXPECTED TO PUSH INTO THE REGION
LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED FORECAST...TEMPERATURES RUNNING COOLER THAN FORECAST SO
LOWERED MAXIMUM TEMPS INTO THE UPPER 40S SOUTHWEST TO CENTRAL AND
LOWER 50S NORTHEAST...WHERE CHANCES OF PRECIPITATION IS LESS AND
CLOUD COVER THINNER. RAIN COOLED AIR AND A DRY NORTHEAST FLOW WILL
IMPEDE TEMPERATURE RISES. THE REST OF THE FORECAST WAS LEFT UNCHANGED.
PRECIPITATION FORECAST IS EXCELLENT IN DEPICTING EXTEND AND
MOVEMENT OF THE RAINFALL SHIELD WHICH COVERS THE SOUTHERN HALF OF
THE FORECAST AREA.
SHORT WAVE CAUSING THIS ACTIVITY IS NOW IN SOUTHWEST SOUTH
CAROLINA AS DEPICTED BY THE WATER VAPOR SATELLITE LOOP. RUC MODEL
TOO FAST...WENT WITH THE SLOWER NAM MODEL, CLOUDS SHOULD BEGIN
LIFTING LATER THIS AFTERNOON AND THE RAIN WILL END FROM THE
SOUTHWEST AS THE SHORT WAVE LIFTS NORTHEAST TAKING THE ISENTROPIC
LIFT WITH IT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
A BUILDING UPPER RIDGE SETS UP OVER THE FORECAST AREA TUESDAY
INTO WEDNESDAY IN RESPONSE TO A DEEP UPSTREAM TROUGH EJECTING FROM
THE DESERT SOUTHWEST. THIS WILL BRING SOME WEAK DOWNSLOPING FLOW
OFF THE MOUNTAINS AND HELP ERODE THE CLOUDS AND ALLOW FOR A
WARMING TREND THROUGH MID WEEK. TEMPERATURES SHOULD CLIMB ABOVE
NORMAL WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO LOWER
40S WITH NO CHANCE FOR PRECIPITATION.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
NO LARGE CHANGES TO THE EXTENDED FORECAST. INCREASING CONFIDENCE
REGARDING THE PASSAGE OF A COLD FRONT THROUGH THE FORECAST AREA
LATE WEEK. LATEST GFS AND ECMWF BOTH SHOWING SHORTWAVE ENERGY
LIFTING THROUGH THE GREAT LAKES REGION AND DEVELOPING WESTERLY
ZONAL FLOW BEHIND THE SHORTWAVE WHICH PUSHES THE FRONT NEAR THE
FORECAST AREA ON FRIDAY AND LIKELY STALLS OR SLOWLY PUSHES THROUGH
THE REGION. DELAYED THE ONSET OF POPS TO THURSDAY NIGHT AND FRIDAY
AND GOING WITH A DRY FORECAST ON THURSDAY AND WARMER TEMPERATURES
AHEAD OF THE FRONT. TEMPERATURES FALL BACK TO NORMAL OVER THE
WEEKEND WITH THE FRONT NEARBY.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
CEILINGS LIFTING OVER THE NORTHERN TERMINALS...STAYING THE SAME OR
LOWERING OVER AGS...DNL...OGB. WEAK ISENTROPIC LIFT ASSOCIATED
WITH SHORTWAVE CURRENTLY OVER WESTERN SOUTH CAROLINA WILL SHIFT
EAST BY THIS EVENING...12 Z NAM AND 06Z GFS ARE IN AGREEMENT IN ENDING
ISENTROPIC LIFT BY TONIGHT. IMPROVED CONDITIONS TO VFR AT BOTH CAE
AND CUB WITH THE BULK OF THE PRECIPITATION EXPECTED TO REMAIN
SOUTH OF THESE LOCATIONS.
LOWERED CEILING AT OGB WHERE WITH THE BEST CHANCE OF RAIN IS AND
KEPT THE FORECAST THE SAME AT AGS AND DNL. MADE MINOR CHANGES TO
THE WIND FORECAST. IN ALL LOCATIONS..HOWEVER NORTHEAST WINDS ARE EXPECTED
THROUGH THE REMAINDER OF THIS AFTERNOON. REST LEFT UNCHANGED FOR
NOW. LOW CEILINGS EXTEND BACK INTO WESTERN ALABAMA. WITH THE LACK
OF A STRONG COLD FRONT TO SCOUR OUT THE MOISTURE...MVFR TO IFR
CEILINGS MAY COME BACK ACROSS THE REGION THIS EVENING. THIS WILL
BE MORE CLOSELY LOOKED AT WITH LATER MODEL RUNS.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1146 PM CST SUN DEC 11 2011
...UPDATE TO AVIATION...
.DISCUSSION...
LATEST WATER VAPOR LOOP AT 20Z WAS SHOWING THE UPPER TROUGH MOVING
SLOWLY ACROSS THE HIGH PLAINS FROM NEBRASKA INTO THE TEXAS
PANHANDLE. SHOWERS HAVE DEVELOPED OUT AHEAD OF THE WAVE IN OKLAHOMA
TODAY AND HAVE BEEN MOVING NORTHEAST SLOWLY THROUGH THE DAY.
SOUNDING FROM 12Z AT TOP AND SGF SHOWED PLENTY OF DRY AIR OFF THE
DECK THIS MORNING. SOME DRY AIR CONTINUES TO BE ENTRAINED THIS
EVENING IN THE EASTERN CWA PER MODEL TIME SECTIONS. LATEST RUN OF
THE RUC DOES NOT BRING ANY MEASURABLE PRECIPITATION AS FAR NORTH
INTO THE SOUTHERN CWA TONIGHT. THE UPPER WAVE WILL MOVE SLOWLY MOVE
ACROSS THE CENTRAL PLAINS TONIGHT WITH THE UPPER TROUGH AXIS MOVING
THROUGH THE EASTERN CWA BY 09Z MONDAY. 925-850 MB WINDS BECOME SOUTH
EARLY THIS EVENING THEN SOUTHWEST OVERNIGHT AND BY MORNING WILL
FOCUS MOISTURE TO THE EAST. EXPECT CLOUDS TO REMAIN THROUGH THE
NIGHT WITH SOME PATCHY FOG AND DRIZZLE POSSIBLE IN THE NORTHWEST
WHILE SPRINKLES ARE MORE LIKELY IN THE EAST. LOWS TONIGHT WILL
REMAIN ABOVE FREEZING SO NO FREEZING OR FROZEN PRECIPITATION IS
EXPECTED.
MONDAY SOME EARLY MORNING PATCHY DRIZZLE OR FOG IS POSSIBLE OFF THE
SNOW PACK TO THE WEST IN NORTH CENTRAL KANSAS. BY MID MORNING A
FRONTAL BOUNDARY WILL APPROACH FROM THE WEST BUT MAKES SLOW PROGRESS
THROUGH THE DAY AND BECOMES STATIONARY FROM SOUTHEAST NEBRASKA INTO
SOUTHWEST KANSAS. SOUTHERLY FLOW AHEAD OF THE FRONT WILL BRING
TEMPERATURES AGAIN IN THE MID AND UPPER 40S TO THE AREA.
53
MODELS ARE SIMILAR IN TAKING UPPER TROUGH OFF THE SOUTHERN CA COAST
MONDAY EVENING AND EJECTING IT NORTHEASTWARD INTO THE CENTRAL HIGH
PLAINS BY MIDDAY WEDNESDAY...THEN RAPIDLY INTO THE WESTERN GREAT
LAKES BY LATE WEDNESDAY NIGHT. THE MODELS ARE IN LESS AGREEMENT ON
HOW FAR SOUTHEAST THE COLD FRONT WILL PUSH SOUTHEAST INTO THE
NORTHWEST COUNTY WARNING AREA (CWA) MONDAY NIGHT BEFORE
STALLING...WITH THE NAM/SREF THE MOST AGGRESSIVE INTO THE NORTHWEST
1/3 OF THE CWA AND THE GFS/EC NOT BRINGING IT INTO THE NORTHWEST
CORNER AT ALL. WILL COMPROMISE FOR NOW WITH SOME
FREEZING/SUBFREEZING TEMPS IN THE FAR NORTHWEST CORNER BEHIND THE
FRONT AND WARMER ABOVE FREEZING TEMPS ELSEWHERE. WITH A CHANCE FOR
DRIZZLE/LIGHT RAIN INCREASING LATER IN THE NIGHT AND NO NON DIURNAL
TREND EXPECTED...CANNOT RULE OUT A WINDOW FOR SOME LIGHT FREEZING
PRECIP IN THE FAR NORTHWEST CORNER OF THE CWA 06-12Z
TUES...OTHERWISE EXPECT THE PRECIP WITH THIS SYSTEM TO BE A RAIN
EVENT TUESDAY THROUGH WEDNESDAY BEFORE ENDING WEDNESDAY NIGHT.
ELEVATED INSTABILITY AND FORCING LOOK SUFFICIENT FOR SOME THUNDER
POTENTIAL AHEAD OF THE FRONT IN THE DEEPER MOISTURE AXIS ACROSS THE
SOUTHEAST HALF OF THE CWA WHERE THE WARMER MORNING LOWS WEDNESDAY
WILL BE IN THE LOW TO MID 40S. AFTER HIGHS IN THE LOW TO MID 40S ON
TUESDAY...SHOULD SEE HIGHS RISE INTO THE LOW TO MIDDLE 50S FOR
WEDNESDAY.
AFTER THIS SYSTEM EXITS...MODELS DIVERGE THROUGH THE END OF THE WEEK
AND INTO NEXT WEEKEND ON HOW QUICKLY THE NEXT SHORTWAVE TO DIG INTO
THE SOUTHWEST CONUS WILL EJECT OUT INTO THE PLAINS. THE ECMWF MODEL
IS ABOUT 2 DAYS SLOWER WITH ITS ARRIVAL AND ASSOCIATED PRECIP THAN
THE GFS. WITH SUCH LOW CONFIDENCE ON ITS ARRIVAL TIME AND CURRENT
DRY FCST THROUGH SATURDAY...OPTED TO KEEP FCST DRY UNTIL SATURDAY
NIGHT/SUNDAY WITH LOW CHANCES FOR RAIN/FREEZING RAIN OR A SNOW
POTENTIAL. AFTER LOWS IN THE 20S AND HIGHS IN THE 30S BOTH FRIDAY
AND SATURDAY...HIGHS TEMPS SHOULD SLOWLY MODERATE AHEAD OF THE NEXT
UPPER TROUGH INTO THE 40S FOR HIGHS ON SUNDAY. 63
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE OVERNIGHT HOURS
WITH BKN/OVC CEILINGS OF 4-6KFT. EXPECT CEILINGS TO LOWER BY THE
MORNING HOURS AND BECOME MVFR/NEAR MVFR FOR THE REMAINDER OF THE
PERIOD.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1121 PM CST SUN DEC 11 2011
.AVIATION...
FOR THE 06Z TAF ISSUANCE...
STATUS CONTINUES TO SPREAD NORTH ACROSS ALL OF THE TAF SITES AS OF
05Z WITH THE 00Z NAM BUFR SOUNDINGS ALSO SUPPORTING A THICKENING
AND LOWERING TREND OF THESE LOW CLOUDS THROUGH THE EARLY MORNING
HOURS. AS THIS STATUS THICKENS AND LOWERS SOME HIGH LEVEL CLOUD
COVER WILL BEGIN TO SPREAD INTO SOUTHWEST KANSAS AS AN UPPER LEVEL
SHORT WAVE TROUGH APPROACHES THE AREA FROM THE SOUTHWEST. AS A
RESULT THIS STATUS WILL BE SLOW TO ERODE SO HAVE DECIDED TO FOLLOW
THE LATEST NAM GUIDANCE, HRRR AND BUFR SOUNDINGS IN KEEPING THESE
LOW CIGS IN PLACE THROUGH AT LEAST LATE MORNING. WINDS WILL
CONTINUE AROUND 20KTS THROUGH MUCH OF THE NIGHT BUT WILL BEGIN TO
SUBSIDE AT OR SHORTLY AFTER 12Z AS A TROUGH OF LOW PRESSURE AT THE
SURFACE STARTS TO MOVE INTO WESTERN KANSAS. GIVEN THESE WINDS SOME
LIGHT FOG WILL BE POSSIBLE BUT AREAS OF DENSE FOG IS NOT
ANTICIPATED. THE POSSIBLE EXCEPTION WILL BE NEAR THE GCK WHERE
WIND SPEEDS ARE EXPECTED BE LIGHTER GIVEN THE CLOSER PROXIMITY TO
THE SURFACE LEE TROUGH EARLY MONDAY MORNING. WILL THEREFORE BE A
LITTLE MORE PESSIMISTIC IN THE VSBYS BETWEEN BETWEEN 12 AND 15Z AT
GCK THAN AT DDC OR HYS. -RB
&&
PREV DISCUSSION... /ISSUED 326 PM CST SUN DEC 11 2011/
DISCUSSION...
DAYS 1-2...
BREEZY SOUTH TO SOUTHWEST WINDS THIS EVENING WILL DECREASE TO AROUND
10 TO 15 MPH BY MORNING. DEWPOINTS ARE ANTICIPATED TO INCREASE A FEW
DEGREES ACROSS EASTERN PORTIONS OF THE CWA AND STRATUS IS EXPECTED
TO REDEVELOP OR CONTINUE, MAINLY ACROSS AREAS EAST OF WAKEENEY TO
LIBERAL. A FEW PLACES MAY EXPERIENCE REDUCED VISIBILITIES DUE TO FOG
AFTER MIDNIGHT, HOWEVER, IT SHOULD NOT BE WIDESPREAD LIKE YESTERDAY.
SOME CIRROSTRATUS IS POSSIBLE ACROSS WESTERN KANSAS AS UPPER LEVEL
MOISTURE MOVES INTO THE PLAINS AHEAD OF THE UPPER LEVEL TROUGH OVER
CALIFORNIA. A COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS NEBRASKA
INTO NORTHERN KANSAS TOMORROW. MODELS THEN HAVE THIS FRONT STALLING
OUT AND BISECTING OUR CWA IN THE AFTERNOON. LOWER TO MID LEVEL
MOISTURE WILL CONTINUE TO INCREASE ACROSS OUR AREA ALLOWING FOR
MOSTLY CLOUDY SKIES TO PREVAIL. THE FRONTAL BOUNDARY THEN MOVES
NORTH AS A WARM FRONT TOMORROW NIGHT. SOME LIGHT DRIZZLE OR LIGHT
RAIN WILL BE POSSIBLE ACROSS THE EASTERN THIRD OF THE CWA WITH
FREEZING FOG OR FREEZING DRIZZLE POSSIBLE ACROSS THE NORTHWESTERN
PORTION OF THE CWA. MODELS CONTINUE TO INDICATE AN UPPER LEVEL
SHORTWAVE MOVING ACROSS NEW MEXICO AND INTO THE HIGH PLAINS ON
TUESDAY. A STRONG 250MB JET WILL BE FOUND ACROSS OUR AREA AT THIS
TIME ENHANCING LIFT ACROSS THE AREA. THESE FEATURES ARE ANTICIPATED
TO BRING A CHANCE OF RAIN ACROSS MUCH OF THE FORECAST AREA.
OTHERWISE EXPECT MOSTLY CLOUDY SKIES. LOWS TONIGHT ARE ANTICIPATED
TO RANGE FROM THE MID TO UPPER 20S IN THE WEST TO MID 30S ACROSS
EASTERN PORTIONS OF THE CWA. LOWS TOMORROW NIGHT ARE EXPECTED TO
RANGE FROM THE LOWER 30S NORTHWEST TO UPPER 30S SOUTHEAST. HIGHS
MONDAY AND TUESDAY ARE ANTICIPATED TO RANGE FROM THE UPPER 30S
NORTHWEST TO UPPER 40S SOUTHEAST.
DAYS 3-7...
THE MEDIUM RANGE FORECAST WILL START WITH A WARM FRONT STRADDLING
THE CWA ON WEDNESDAY, WITH A SHORT WAVE ALOFT PASSING FROM WEST TO
EAST. RAIN WILL MOSTLY LIKELY FALL WEDNESDAY OVER MOST OF THE CWA.
A FEW THUNDERSTORMS WILL BE POSSIBLE ACROSS THE EXTREME SOUTHEAST
CWA WEDNESDAY AFTERNOON, WITH EITHER FREEZING DRIZZLE OR LIGHT SNOW
MORE POSSIBLE IN OUR EXTREME NORTHWESTERN COUNTIES. THIS SHORT WAVE
IN THE 500MB LEVEL IS SMALL BUT POTENT, AND IT SHOULD KEEP SOME
PRECIP ACROSS OUR EAST UNTIL EARLY WEDNESDAY NIGHT. THURSDAY AND
FRIDAY WILL BE BETWEEN UPPER SYSTEMS AND SHOULD BE DRY. IT WILL
COOL DOWN THURSDAY AND FRIDAY FROM THE HIGHS ON WEDNESDAY IN THE
UPPER 40S NORTHWEST TO THE UPPER 50S IN THE SOUTHEAST. HIGHS BY
FRIDAY WILL ONLY RANGE FROM THE UPPER 30S IN OUR NORTH TO THE MIDDLE
40S ACROSS OUR SOUTH. SATURDAY WILL COOL DOWN DUE TO INCREASING
CLOUDS AND A SLIGHT FOR SNOW MOVING IN FROM THE SOUTH. THE TRACK OF
THE ASSOCIATED UPPER LOW WILL PLAY HEAVILY ON IF AND WHERE WE GET
ANY SNOW. BUT, IT DOES LOOK LIKE THE GEM AND GFS BOTH TRACK THE
UPPER 500 MB LOW DOWN INTO SOUTHWESTERN NEW MEXICO BY SATURDAY, AND
THEN BRING THE LOW NORTHEASTWARD INTO NORTH CENTRAL OKLAHOMA BY
SUNDAY NIGHT. THE EC MODEL IS SLOWER AND A BIT FARTHER SOUTH WITH
THE SYSTEM. ANYWAY, THE CREXTENDED MODEL INITIALLY PLACED 60 POPS
IN MY SOUTHEAST SUNDAY, GRADUATING DOWNWARD TO 30 POPS ACROSS OUR
WEST. I DID LOWER THE POPS TO 40 PERCENT IN OUR SOUTHEAST AND 30
PERCENT IN OUR WEST SUNDAY. THESE POPS CAN BE ADJUSTED UPWARDS OR
DOWNWARDS LATER, AS MODEL TRENDS BECOME MORE RELIABLE. FOR NOW, IF
THE GFS MODEL IS RIGHT, 2 TO 4 INCHES COULD FALL ACROSS A PORTION OF
OUR CWA SATURDAY NIGHT INTO SUNDAY. IF THE EC MODEL IS MORE
CORRECT, THEN JUST OUR SOUTHERN CWA WILL SEE SOME SNOW AND IT WILL
BE LATER THAN SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 35 44 35 46 / 10 20 50 50
GCK 32 42 32 45 / 0 10 40 50
EHA 27 43 37 48 / 10 10 40 40
LBL 34 45 37 49 / 10 10 40 40
HYS 34 41 32 43 / 10 10 40 50
P28 35 47 39 48 / 10 20 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1247 PM CST MON DEC 12 2011
.DISCUSSION...
18Z TAF PACKAGE.
&&
.AVIATION...
CHALLENGING AVIATION FORECAST THIS CYCLE...WITH NEAR TERM CONCERN
THE LOW STRATUS DECK OVER THE ACADIANA TERMINALS. VISIBLE
SATELLITE IMAGERY SHOWING STEADY EROSION OF THIS CLOUD DECK...SO A
TEMPO GROUP WAS USED AT KLFT AND KARA FOR THE NEXT 1 TO 2 HOURS
RESPECTIVELY. VFR WILL PREVAIL HERE THE REST OF THE AFTERNOON INTO
THE EARLY EVENING...BUT MODEL GUIDANCE IS INDICATING A RETURN OF
LOW CLOUDS/VISIBILITY RESTRICTIONS LATER TONIGHT. WILL BRING
PREVAILING LIFR HERE AND ALSO KAEX WHERE ADVECTI0N OF THE LOWER
CLOUD DECK IS EXPECTED. MORE UNCERTAINTY EXISTS FARTHER WEST AS MID LEVEL
CLOUDS AND HIGHER BOUNDARY LAYER WINDS COME INTO PLAY. WILL LOWER
TO MVFR FOR NOW...BUT THIS MAY PROVE OPTIMISTIC IN LIGHT OF
VISIBLE SATELLITE LOOP SHOWING WESTWARD PROGRESSION OF MARINE
STRATUS ALONG THE LA COAST.
13
&&
.PREV DISCUSSION... /ISSUED 1116 AM CST MON DEC 12 2011/
UPDATE...STRATUS NOW OVER ACADIANA/EAST CENTRAL LOUISIANA HAS
STALLED ITS WESTWARD MIGRATION AND IS IN THE PROCESS OF ERODING.
RAPID WARMUP THEN EXPECTED OVER ACADIANA. BULK OF WIDESPREAD
ALTOCUMULUS OVER EAST TEXAS/NORTH LOUISIANA SHOULD REMAIN PRIMARILY
OVER THIS AREA PER LATEST RUC 850-700 MB RH. WILL MAINTAIN CURRENT
FORECAST. NO UPDATE COMING.
MARCOTTE
PREV DISCUSSION... /ISSUED 520 AM CST MON DEC 12 2011/
DISCUSSION...
12Z TAF ISSUANCE.
AVIATION...
MID LEVEL BKN/OVC DECK ~9000FT MOVING ACROSS SE TX...EXPECTED TO
GRADUALLY MOVE EAST ACROSS C AND SC LA TODAY...OTHERWISE VFR
EXPECTED THROUGH THE PERIOD. NE WINDS EXPECTED TO GRADUALLY
BECOME MORE E BY LATE AFTERNOON AND EVENING.
DML
PREV DISCUSSION... /ISSUED 438 AM CST MON DEC 12 2011/
DISCUSSION...
SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC
COAST CONTINUING TO RIDGE OVER THE FORECAST AREA WITH LIGHT NERLY
LOW-LEVEL LOW PREVAILING AGAIN THIS MORNING. WATER VAPOR IMAGERY
SHOWS A DECENT SHORTWAVE CROSSING THE SRN PLAINS/WRN GULF COAST
STATES WHICH HAS HELPED PRODUCED A FEW SPRINKLES OR VERY LIGHT
SHOWERS MAINLY OVER THE WRN 1/2 OF THE FORECAST AREA SO FAR
OVERNIGHT. MEANWHILE WRLY FLOW ALOFT FROM THE PACIFIC CONTINUING
TO SPREAD PLENTY OF MID/UPPER-LEVEL MOISTURE AND ASSOCIATED CLOUDINESS
OVER THE REGION. TEMPS HAVE DIPPED JUST BELOW FREEZING ACROSS THE
NERN EXTREME OF THE FORECAST AREA WHERE CLOUDS HAVE YET TO
ENCROACH AND CUT OFF THE GOOD RADIATIVE COOLING...OTHERWISE TEMPS
GENERALLY IN THE MID/UPPER 30S ALONG/EAST OF THE SABINE AND
LOWER/MID 40S OVER SERN TX.
NO SIGNIFICANT CHANGES TO THE EARLY PART OF THIS FORECAST PACKAGE.
ANOTHER DAY OF LIGHT ERLY/NERLY FLOW EXPECTED TODAY AS THE SFC
HIGH LINGERS NEAR THE ERN SEA BOARD. MEANWHILE SRLY FLOW WILL
BEGIN TO DEVELOP ALOFT AS STRONG STORM SYSTEM CRASHES ASHORE ALONG
THE SRN CALIFORNIA COAST. RISING HEIGHTS/WARMING ALOFT WILL LEAD
TO THE BEGINNINGS OF A WARMING TREND WITH MAX TEMPS TODAY
GENERALLY 10 DEGREES WARMER THAN YESTERDAY. MEANWHILE MINS TONIGHT
FORECAST TO JUMP ALL THE WAY TO THE MID/UPPER 40S...WITH LOWER 50S
COASTAL LA AND GOLDEN TRIANGLE REGION.
MOISTURE WILL CONTINUE TO INCREASE THROUGH THE EARLY PART OF THE
WEEK AS LOW-LEVEL FLOW VEERS AROUND TO THE SOUTHEAST. DEWPOINTS
WILL CLIMB TO THE 50S/LOWER 60S THROUGH TUESDAY WHICH WILL ALLOW
FOR SOME FOG DEVELOPMENT...ESPECIALLY NEAR THE COAST WITH SST
CURRENTLY RUNNING IN THE LOWER/MID 50S.
THE SYSTEM MOVING ASHORE OVER SRN CA TODAY WILL EJECT NEWD THROUGH
MID-WEEK SPAWNING SFC LOW DEVELOPMENT OVER THE LEE OF THE ROCKIES
ON WEDNESDAY. THE LOW WILL PUSH NEWD...GRADUALLY PULLING A SFC
FRONTAL BOUNDARY TOWARD THE REGION. MODELS THIS MORNING ARE IN
BETTER AGREEMENT WITH OOZING THE FRONT ACROSS THE FORECAST AREA
LATE THURSDAY/EARLY FRIDAY TIME FRAME. NOT MUCH LIFT EXPECTED
ALOFT WITH BEST ENERGY PULLING WELL NE OF THE AREA BY FROPA...
INSTABILITY FAIRLY NEGLIGIBLE AS WELL SO ATTM EXPECTING MAINLY
JUST SCATTERED SHOWERS WITH THE FRONT WITH MAYBE SOME ISOLATED
THUNDER OVER THE FAR NERN ZONES. DUE TO THE SLOW-MOVING NATURE OF
THE FRONT AND FAIRLY NON-PROGRESSIVE PATTERN ALOFT WE COULD SEE A
FEW DAYS OF LINGERING SHOWERS AND THUS HAVE KEPT SMALL POPS IN THE
FORECAST THROUGH THE WEEKEND.
MARINE...
MAINLY LIGHT FLOW EXPECTED TODAY AND TONIGHT WITH HIGH PRESSURE
REMAINING IN CONTROL. WINDS WILL BEGIN TO INCREASE GRADUALLY
STARTING TOMORROW WITH LOW PRESSURE DEVELOPING OFF THE ROCKIES
ALTHOUGH SPEEDS SHOULD REMAIN BELOW ANY FLAGS. WINDS WILL STEADILY
VEER TO A SERLY DIRECTION THROUGH MID-WEEK...BECOMING MORE SRLY ON
THURSDAY AS THE FRONT APPROACHES...THEN FINALLY SHIFT TO AN
OFFSHORE FLOW POST-FROPA FRIDAY. SPLIT THE DIFFERENCE ON SPEEDS
BEHIND THE FRONT AS THE GFS GOES SCA WITH ITS NRLY WINDS...WHILE
THE EC IS A BIT MORE SLUGGISH WITH WINDS TOPPING OUT AROUND 10
KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 48 69 59 73 / 0 10 10 10
KBPT 52 69 61 73 / 0 10 10 20
KAEX 44 69 54 74 / 0 10 10 20
KLFT 48 69 57 74 / 0 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1116 AM CST MON DEC 12 2011
.UPDATE...STRATUS NOW OVER ACADIANA/EAST CENTRAL LOUISIANA HAS
STALLED ITS WESTWARD MIGRATION AND IS IN THE PROCESS OF ERODING.
RAPID WARMUP THEN EXPECTED OVER ACADIANA. BULK OF WIDESPREAD
ALTOCUMULUS OVER EAST TEXAS/NORTH LOUISIANA SHOULD REMAIN PRIMARILY
OVER THIS AREA PER LATEST RUC 850-700 MB RH. WILL MAINTAIN CURRENT
FORECAST. NO UPDATE COMING.
&&
MARCOTTE
&&
.PREV DISCUSSION... /ISSUED 520 AM CST MON DEC 12 2011/
DISCUSSION...
12Z TAF ISSUANCE.
AVIATION...
MID LEVEL BKN/OVC DECK ~9000FT MOVING ACROSS SE TX...EXPECTED TO
GRADUALLY MOVE EAST ACROSS C AND SC LA TODAY...OTHERWISE VFR
EXPECTED THROUGH THE PERIOD. NE WINDS EXPECTED TO GRADUALLY
BECOME MORE E BY LATE AFTERNOON AND EVENING.
DML
PREV DISCUSSION... /ISSUED 438 AM CST MON DEC 12 2011/
DISCUSSION...
SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC
COAST CONTINUING TO RIDGE OVER THE FORECAST AREA WITH LIGHT NERLY
LOW-LEVEL LOW PREVAILING AGAIN THIS MORNING. WATER VAPOR IMAGERY
SHOWS A DECENT SHORTWAVE CROSSING THE SRN PLAINS/WRN GULF COAST
STATES WHICH HAS HELPED PRODUCED A FEW SPRINKLES OR VERY LIGHT
SHOWERS MAINLY OVER THE WRN 1/2 OF THE FORECAST AREA SO FAR
OVERNIGHT. MEANWHILE WRLY FLOW ALOFT FROM THE PACIFIC CONTINUING
TO SPREAD PLENTY OF MID/UPPER-LEVEL MOISTURE AND ASSOCIATED CLOUDINESS
OVER THE REGION. TEMPS HAVE DIPPED JUST BELOW FREEZING ACROSS THE
NERN EXTREME OF THE FORECAST AREA WHERE CLOUDS HAVE YET TO
ENCROACH AND CUT OFF THE GOOD RADIATIVE COOLING...OTHERWISE TEMPS
GENERALLY IN THE MID/UPPER 30S ALONG/EAST OF THE SABINE AND
LOWER/MID 40S OVER SERN TX.
NO SIGNIFICANT CHANGES TO THE EARLY PART OF THIS FORECAST PACKAGE.
ANOTHER DAY OF LIGHT ERLY/NERLY FLOW EXPECTED TODAY AS THE SFC
HIGH LINGERS NEAR THE ERN SEA BOARD. MEANWHILE SRLY FLOW WILL
BEGIN TO DEVELOP ALOFT AS STRONG STORM SYSTEM CRASHES ASHORE ALONG
THE SRN CALIFORNIA COAST. RISING HEIGHTS/WARMING ALOFT WILL LEAD
TO THE BEGINNINGS OF A WARMING TREND WITH MAX TEMPS TODAY
GENERALLY 10 DEGREES WARMER THAN YESTERDAY. MEANWHILE MINS TONIGHT
FORECAST TO JUMP ALL THE WAY TO THE MID/UPPER 40S...WITH LOWER 50S
COASTAL LA AND GOLDEN TRIANGLE REGION.
MOISTURE WILL CONTINUE TO INCREASE THROUGH THE EARLY PART OF THE
WEEK AS LOW-LEVEL FLOW VEERS AROUND TO THE SOUTHEAST. DEWPOINTS
WILL CLIMB TO THE 50S/LOWER 60S THROUGH TUESDAY WHICH WILL ALLOW
FOR SOME FOG DEVELOPMENT...ESPECIALLY NEAR THE COAST WITH SST
CURRENTLY RUNNING IN THE LOWER/MID 50S.
THE SYSTEM MOVING ASHORE OVER SRN CA TODAY WILL EJECT NEWD THROUGH
MID-WEEK SPAWNING SFC LOW DEVELOPMENT OVER THE LEE OF THE ROCKIES
ON WEDNESDAY. THE LOW WILL PUSH NEWD...GRADUALLY PULLING A SFC
FRONTAL BOUNDARY TOWARD THE REGION. MODELS THIS MORNING ARE IN
BETTER AGREEMENT WITH OOZING THE FRONT ACROSS THE FORECAST AREA
LATE THURSDAY/EARLY FRIDAY TIME FRAME. NOT MUCH LIFT EXPECTED
ALOFT WITH BEST ENERGY PULLING WELL NE OF THE AREA BY FROPA...
INSTABILITY FAIRLY NEGLIGIBLE AS WELL SO ATTM EXPECTING MAINLY
JUST SCATTERED SHOWERS WITH THE FRONT WITH MAYBE SOME ISOLATED
THUNDER OVER THE FAR NERN ZONES. DUE TO THE SLOW-MOVING NATURE OF
THE FRONT AND FAIRLY NON-PROGRESSIVE PATTERN ALOFT WE COULD SEE A
FEW DAYS OF LINGERING SHOWERS AND THUS HAVE KEPT SMALL POPS IN THE
FORECAST THROUGH THE WEEKEND.
MARINE...
MAINLY LIGHT FLOW EXPECTED TODAY AND TONIGHT WITH HIGH PRESSURE
REMAINING IN CONTROL. WINDS WILL BEGIN TO INCREASE GRADUALLY
STARTING TOMORROW WITH LOW PRESSURE DEVELOPING OFF THE ROCKIES
ALTHOUGH SPEEDS SHOULD REMAIN BELOW ANY FLAGS. WINDS WILL STEADILY
VEER TO A SERLY DIRECTION THROUGH MID-WEEK...BECOMING MORE SRLY ON
THURSDAY AS THE FRONT APPROACHES...THEN FINALLY SHIFT TO AN
OFFSHORE FLOW POST-FROPA FRIDAY. SPLIT THE DIFFERENCE ON SPEEDS
BEHIND THE FRONT AS THE GFS GOES SCA WITH ITS NRLY WINDS...WHILE
THE EC IS A BIT MORE SLUGGISH WITH WINDS TOPPING OUT AROUND 10
KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 62 48 69 59 73 / 0 0 10 10 10
KBPT 62 52 69 61 73 / 0 0 10 10 20
KAEX 61 44 69 54 74 / 0 0 10 10 20
KLFT 65 48 69 57 74 / 0 0 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
819 PM EST TUE DEC 13 2011
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH OVER THE WRN CONUS
AND A RIDGE OVER THE SE WITH MAINLY ZONAL FLOW FROM THE NRN PLAINS
TO NEW ENGLAND. A VIGOROUS SHORTWAVE TROUGH WAS MOVING THROUGH AZ
WHILE A WEAKER UPSTREAM SHRTWV WAS MOVING INTO SRN SD. AT THE
SFC...A RIDGE EXTENDED FROM NORTHERN QUEBEC TO LAKE SUPERIOR
RESULTING IN WEAK ACYC FLOW OVER THE CWA WITH NO PCPN INDICATED BY
RADAR. WITH THE MILD/MOIST AIRMASS IN PLACE...PATCHY FOG LINGERED
OVER LOCATIONS NEAR THE WI BORDER.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
TONIGHT...AS THE HIGH SLIDES OFF TO THE SE...SRLY LOW LEVEL FLOW
WILL INCREASE WEAK UPSLOPE FLOW INTO PORTIONS OF WEST AND CENTRAL
UPPER MI MAY BE ENOUGH TO SUPPORT SOME PATCHY -DZ/-FZDZ AFT 06Z EVEN
THOUGH OVERALL LOW LEVEL (925-850 MB) LIFT IS VERY WEAK...PER
NAM/RUC...280K ISENTROPIC PROGS. OTHERWISE...WITH LITTLE DIURNAL
TEMP CHANGE IS EXPECTED OVER THE AREA. AREAS OF FOG...SOME LCLY
DENSE...MAY ALSO THICKEN WITH SLIGHT INCREASE IN MOISTURE ADVECTION.
WEDNESDAY...AS LOW PRESSURE DEVELOPS IN THE CENTRAL PLAINS AND MOVES
TOWARD THE UPPER MS VALLEY...LOW/MID LEVEL WAA AND MOISTURE
ADVECTION WILL INCREASE. THIS SHOULD BRING AN AREA OF LIGHT PCPN
OVER THE ENTIRE CWA BY AFTERNOON...PER NAM/GFS 290K-295K ISENTROPIC
PROGS. NAM WET-BULB ZERO HEIGHTS SUGGEST THAT THE PCPN SHOULD BE
MAINLY RAIN. HOWEVER...GIVEN LOW LEVEL TEMP PROFILES NEAR 0C OVER
THE INTERIOR WEST...CANNOT RULE OUT SOME SNOW. ANY ACCUMULATIONS
WOULD BE MINIMAL. EVEN THOUGH TEMPS WILL BE ABOVE FREEZING WHEN THE
RAIN ARRIVES...SOME UNTREATED ROADS MAY STILL BE COLD ENOUGH TO
CREATE PATCHY ICY SPOTS.
.LONG TERM /WED NIGHT THROUGH NEXT TUESDAY/...
SHORTWAVE CURRENTLY ROUNDING THE UPPER TROUGH OFF THE COAST OF SRN
CA WILL MOVE TOWARDS THE AREA LATE WED AFTN AND MOVE ACROSS THE AREA
WED EVENING. MODELS FAIRLY CONSISTENT ON THE MAIN ENERGY FROM THE
SHORTWAVE MOVING ACROSS CNTRL/ERN UPPER MI...WHICH WILL GRADUALLY
INTENSIFY THE LOW MOVING FROM IOWA AT 00Z THURS TO SE ONTARIO AT 12Z
THURS. OTHER THAN THE FAST AND NW OUTLIER 12Z NAM...MAIN DIFFERENCES
BETWEEN THE MODELS IS IN THE INTENSITY OF THE LOW. 06-12Z GFS RUNS
ON THE STRONG SIDE AND 00Z ECMWF ON WEAKER SIDE. WILL FOLLOW A BLEND
OF THE TWO SINCE TRACKS ARE SIMILAR AND ONLY MINOR DIFF IN THE
THERMAL PROFILES.
DURING THE EVENING...06 AND 12Z GFS SHOWING STRONG FGEN FROM
H800-400 ACROSS THE CWA. THINK THE BEST FORCING WILL BE ALONG THE
H800-600 FGEN AREA...WHERE THERE IS ABUNDANT MOISTURE AND STRONG
AGEOSTROPHIC UPWARD CIRCULATION. FARTHER NW...APPEARS TO BE A DECENT
H700-500 DRY AIR LAYER...AND DOWNWARD CIRCULATION MAY LIMIT PCPN
FARTHER NW TOWARDS A KIWD TO KCMX LINE. OVER THE E...EXPECT A STRONG
AREA OF H850-700 WAA AND 285-300K SFC ISENTROPIC ASCENT DURING THE
EVENING. THINK THE EXISTING 100 POPS LOOK GOOD AND WILL LEAVE THEM
AS IS. THEN HAVE A GRADUAL LOWERING HEADING OVER THE WEST TOWARDS
HIGH END LIKELY. COULD BE A SHARP CUTOFF TO THE WEST EXTENT OF THE
PCPN OVER THE WRN HALF OF LK SUPERIOR WITH THE FGEN CIRCULATION...SO
TRIED TO SHOW THAT POTENTIAL.
P-TYPE FOR THE WED NIGHT PERIOD IS WHERE THINGS GET TRICKY. BUFKIT
SOUNDINGS FROM THE GFS SHOW AN ISOTHERMAL PROFILE FROM SFC TO
5-6KFT. WITH THAT TYPE OF SITUATION...IT WILL LIKELY BE SNOW WHERE
LAYER IS NEAR 0C AND THEN RA/SN AROUND 1C AND ALL RA AROUND 2-3C.
KCMX MAY BE FAR ENOUGH N AND AWAY FROM THE WARM SURGE TO KEEP PCPN A
RA/SN MIX OR POSSIBLY EVEN ALL SNOW. THEN HEADING S AND E ACROSS THE
CWA...EXPECT A TRANSITION TO ALL RAIN. BIGGEST CONCERN IS GETTING
THAT RA/SN AREA PINNED DOWN AND STILL DON/T HAVE A GREAT FEEL...BUT
IT SHOULD BE OVER THE NW THIRD. FORTUNATELY...THE HEAVIEST QPF WILL
LIKELY BE TO THE SE OF THE UNCERTAIN AREA FOR RA/SN...SO IT SHOULD
LIMIT THE IMPACT IF IT DOES END UP ALL SNOW.
LAST COUPLE OF RUNS OF THE GFS HAVE REALLY BUMPED UP THE QPF IN THE
FGEN LOCATION MOVING ACROSS CNTRL UPPER MI...WITH LIQUID AMOUNTS
EXCEEDING 0.75IN...BUT IT IS LIKELY DUE TO THE MORE WRAPPED UP LOW
SOLN. WILL NOT GO THAT HIGH...BUT WILL NEED TO BE MONITORED IF
STRONGER LOW SOLN PANS OUT. OTHERWISE...EXPECT 0.25 TO 0.4 OF LIQUID
ACROSS THE SE HALF OF THE CWA...MAINLY DURING THE EVENING.
MAIN ENERGY AND DEEPER H700-500 MOISTURE PULLS OUT OVERNIGHT WED AND
HAVE DIMINISHING POPS TO ACCOUNT FOR THAT. P-TYPE IS AGAIN A CONCERN
HEADING INTO THE OVERNIGHT...SINCE THE DEEPER MOISTURE PULLS OUT
BEFORE THE COLDER AIR ARRIVES LATE WED NIGHT INTO THURS. THIS WILL
CUT THE POTENTIAL FOR ICE CRYSTALS IN THE CLOUD WAY DOWN AND LIMIT
THE POTENTIAL FOR SNOW. WITH TEMPERATURES DROPPING TOWARDS FREEZING
OVER THE WEST TOWARDS 12Z THURS...DID KEEP A MENTION OF -FZRA IN THE
FORECAST LATE...BUT POTENTIAL SEEMS LIMITED DURING THE OVERNIGHT
HOURS WITH THE SHORT PERIOD OF AT OR BELOW FREEZING TIME.
OTHERWISE...WILL ONLY MENTION A LOW CHANCE FOR SNOW OVER THE WEST
OVERNIGHT DUE TO LIMITED ICE CRYSTAL PRESENCE AND RAIN OVER THE
CENTRAL AND EAST. THINK THE BIGGEST HAZARD IS MORE LIKELY TO BE THE
WET ROADS ICING UP ON THURS...AS TEMPS FALL BELOW FREEZING THROUGH
THE DAY.
NRN STREAM UPPER TROUGH WILL SWEEP THROUGH THE CWA ON THURS. STILL
DIFFERENCES IN THE SPEED/INTENSITY IN THE MODELS WITH THIS
WAVE...BUT ALL HAVE THE GENERAL IDEA OF IT MOVING THROUGH THE UPPER
GREAT LKS ON THURS. THIS WAVE WILL DROP H850 TEMPS THROUGH THE DAY
TO -12C OVER THE W BY 00Z FRI. THESE COLDER TEMPS WILL STAY OVER THE
AREA THROUGH THE DAY FRI...ANOTHER WEAKER SHORTWAVE DROPS ACROSS THE
AREA. WITH TEMPS ALOFT PUTTING THE CLOUD LAYER BACK INTO THE ICE
CRYSTAL AREA ON THURS...EXPECT TO CHANCES FOR SNOW AS THE P-TYPE TO
BE ON THE INCREASE FROM WEST TO EAST. SHORTWAVE ENERGY WILL HELP
ENHANCE THE DEVELOPING LES THROUGH THE DAY. WILL CONTINUE TREND OF
HIGHER POPS OVER THE WEST IN THE MORNING WITH LES DEVELOPING AND
SHORTWAVE ARRIVING...THEN INCREASE LES POPS OVER THE E UNDER NW
WINDS IN THE AFTN INTO THURS NIGHT. IN ADDITION...WITH THE LOW
INTENSIFYING TO THE NE OF THE AREA...EXPECT A BREEZY DAY ON THURS
ACROSS THE AREA. THE HIGHEST WINDS SHOULD BE OVER THE E NEAR LK
SUPERIOR...WHERE WINDS COULD GUST TO 40-45MPH LATE IN THE AFTERNOON.
SFC RIDGE QUICKLY MOVES FROM W TO E OVER THE CWA ON THURS NIGHT INTO
FRI. MODELS SHOWING VERY PRONOUNCED H925-700 DRYING WITH THE ARRIVAL
OF THE RIDGE...SO HAVE TRENDED BACK LES POPS...ESPECIALLY OVER THE
WEST WHERE BUFKIT SOUNDINGS SHOWING INVERSION HEIGHTS FALLING
TOWARDS 3KFT. DID KEEP LIKELY/S OVER THE NW WIND FAVORED E LOCATIONS
THURS NIGHT INTO FRI MORNING...BUT DROPPED TO CHANCES IN THE AFTN AS
THE DRY AIR LIMITS POTENTIAL.
DAYS 4 THROUGH 7 /FRI NIGHT THROUGH NEXT TUESDAY/...
WEAK SHORTWAVE MOVING ACROSS THE AREA FRI NIGHT WILL BRING A LITTLE
MORE MOISTURE TO THE AREA AND KEEP COLDER AIR IN PLACE. EXPECT
ONGOING LES TO CONTINUE OVER THE E...WITH WINDS GRADUALLY SHIFTING
MORE WRLY. LES MAY TRY TO REDEVELOP OVER THE W WITH THE ARRIVAL OF
THE SHORTWAVE AND ADDITIONAL LLVL MOISTURE. WILL GO WITH LOW CHANCES
OVER THE KEWEENAW WITH THE MORE WRLY WINDS AND THEN LOW END LIKELY/S
OVER THE EAST.
UPPER TROUGH SHIFTS E ON SAT AND DRAGS A SFC TROUGH OVER NRN LK
SUPERIOR AND SRN ONTARIO THROUGH THE DAY AND INTO SAT NIGHT. THERE
HAS BEEN A STRONGER TREND WITH THE SFC FEATURES AND UPPER FORCING
OVER THE LAST DAY FOR THE SAT AND SAT NIGHT PERIOD...SO HAVE BUMPED
POPS UP TO SLIGHTS OVER THE NRN U.P. AND CHANCES OVER THE LAKE.
SOME DIFFERENCES APPEAR IN THE EXTENDED MODELS ON SUN INTO MON WITH
THE HANDLING OF A POTENTIAL RIDGE IN THE NRN STREAM AND A CLOSED LOW
OVER THE SW CONUS. LATEST 12Z RUN OF THE GFS HAS TRENDED SLOWER WITH
THE EXIT OF THE UPPER LOW OVER THE SW CONUS SUN INTO MON...AND MORE
IN LINE WITH THE 00Z ECMWF...SO HAVE FOLLOWED THAT FOR THE REST OF
THE EXTENDED. SFC RIDGE WILL MOVE ACROSS THE CWA ON SUN INTO SUN
NIGHT. NRN STREAM SHORTWAVE WILL APPROACH THE AREA MON INTO
TUES...BRINGING ANOTHER LOW CHANCE OF PCPN. HAS BEEN A GOOD AMOUNT
OF FLUCTUATION IN H850 TEMPS AFTER SUN...SO HAVE LIMITED CONFIDENCE
IN VALUES...BUT APPEARS THAT TEMPS WILL SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
LOW-LEVELS WILL REMAIN MOIST THROUGH THE TAF PERIOD AS A LOW
PRESSURE SYSTEM OVER THE CENTRAL PLAINS LIFTS NORTH INTO THE UPPER
GREAT LAKES ON WEDNESDAY. LIMITED MIXING TONIGHT AND MOIST LOW-LVLS
WILL CONTRIBUTE TO LOWER IFR CONDITIONS WITH CONDITIONS POSSIBLY
FALLING TO AROUND AIRPORT MINIMUMS WHEN WINDS PROVIDE ADDITIONAL
UPSLOPE LIFT. SOME DRYING MAY WORK INTO THE AREA TONIGHT AS WINDS
BECOME MORE SOUTHERLY. BEST CHANCE OF IMPROVEMENT WILL BE AT KIWD
WITH DOWNSLOPE WINDS...WHILE KSAW WILL REMAIN IFR AS SRLY WINDS ADD
ADDITIONAL MOISTURE OFF OF LK MICHIGAN AND ALSO PROVIDE SOME
UPSLOPE. CONFIDENCE IN DETAILS THROUGH ENTIRE TAF PERIOD IS ON THE
LOW SIDE. IN GENERAL...SIGNIFICANT IMPROVEMENT IS NOT ANTICIPATED
THROUGH WEDNESDAY MORNING. RAIN IS EXPECTED WED AFTERNOON AS SYSTEM
APPROACHES FROM THE CENTRAL PLAINS. THIS ADDITIONAL MOISTURE WILL
LIKELY KEEP CIGS IN THE LIFR CATEGORY WITH VBSYS RANGING FROM IFR TO
MVFR DURING THE DAY.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LIGHT SOUTHERLY WINDS WILL INCREASE INTO THE 15 TO 25 KT RANGE OVER
THE CENTRAL AND EAST PORTIONS OF THE LAKE WED AHEAD OF LOW PRESSURE
DEVELOPING IN THE PLAINS. THE LOW IS FCST TO DEEPEN AS IT LIFTS
ACROSS THE UPPER LAKES BY THURSDAY MORNING. STRONGEST WINDS THIS
WEEK WILL OCCUR JUST IN THE WAKE OF THE LOW THURSDAY MORNING THROUGH
MIDNIGHT THURSDAY NIGHT. CONFIDENCE THAT 35-40 KT GALES WILL OCCUR
IS HIGH SO THE WATCH CONTINUES FOR MUCH OF LK SUPERIOR. STRONG WINDS
WILL DIMINISH ON FRI WITH THE SLOW APPROACH OF A HIGH PRESSURE
RIDGE. A STRONGER SW FLOW WILL REDEVELOP ON SAT AFTER THIS HIGH
SHIFTS TO THE SE WITH WINDS TO AROUND 30 KT OVER WEST AND CENTRAL
PORTIONS OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JV
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
407 PM EST MON DEC 12 2011
.SYNOPSIS...
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS
NAMERICA WITH SRN BRANCH SW FLOW ALF OVER THE GRT LKS BTWN RDG OVER
THE ERN CONUS AND A WRN TROF. A SHRTWV EMBEDDED IN THIS SW FLOW IS
OVER MN AND CAUSING AN AREA OF -RA OVER WI INTO SE UPR MI...WHERE
DEEPER MSTR IS PRESENT. SOME SN IS MIXING IN WITH THIS PCPN IN THE
PRESENCE OF DYNAMIC COOLING ACCOMPANYING THE SHRTWV EVEN THOUGH SFC
TEMPS ARE ABV 32. ISSUED SPS THIS AFTN TO ACCOUNT FOR PERIODS OF
HEAVY SN/SLUSHY ACCUMS IN A SWATH OVER THE CNTRL WHERE DYNAMIC
COOLING RELATED TO AREA OF H85-7 FGEN IS MOST PRONOUNCED. OTRW...
TEMPS OVER THE ENTIRE CWA ARE WELL ABV NORMAL AND IN THE 30S.
ABUNDANT LLVL MSTR WITH DWPTS ALSO IN THE 30S IN LGT SW SFC FLOW HAS
CAUSED QUITE A BIT OF LO CLD/FOG OVER THE CWA...BUT A COLD FNT TO
THE N ASSOCIATED WITH A DISTURBANCE IN THE ARCTIC BRANCH OVER CAN IS
PRESSING SLOWLY SWD INTO LK SUP. THE COLD AIR BEHIND THIS FNT IS
QUITE SHALLOW PER THE 12Z INL RAOB...BUT SFC TEMPS AT NOON FALL
QUITE SHARPLY FM ARND 35 OVER THE KEWEENAW AND AHEAD OF THE FNT TO
19 AT THUNDER BAY ONTARIO.
&&
.SHORT TERM DISCUSSION /TNGT AND TUE/...
MAIN FCST CONCERNS IN THE SHORT TERM ARE PCPN CHCS/PTYPE ASSOCIATED
WITH SHRTWV LIFTING INTO WI. FOCUS FOR LATER TNGT AND TUE SHIFTS TO
INFLUX OF COLDER/DRIER AIR FM THE N AND IMPACT ON THE WX.
TNGT...SHRTWV OVER WI AND ACCOMPANYING DYNAMICS/DEEPER MSTR ARE
PROGGED TO LIFT OUT AND EXIT THE ERN ZNS BY LATE EVNG...SO GOING
MORE WDSPRD MIXED PCPN OVER MAINLY THE SE HALF WL DIMINISH WITH MID
LVL SUBSIDENCE/DRYING OVERSPREADING THE FA. HOWEVER...INFLUX OF
SHALLOW COLD AIR FOLLOWING NW-SE PASSAGE OF SFC COLD FNT WL MAINTAIN
A SHARP LLVL INVRN AND PRESENT OVC ST/SC DECK. IN PLACES WITH
UPSLOPE WIND FLOW...OPTED TO MAINTAIN MENTION OF -DZ/-FZDZ WITH
SHALLOW MSTR WELL BLO THE DGZ AND UNDER SUBSIDENCE ALF. CONSIDERING
THE LLVL CHILL OBSVD UPSTREAM...TENDED TO GO TOWARD THE LO SIDE OF
GUIDANCE FOR TEMPS FOLLOWING THE COLD FROPA. EVEN SO...AIRMASS WL
NOT BE SUFFICIENTLY COLD TO SUPPORT LES WITH SHARP INVRN.
TUE...SHALLOW COLD WEDGE WL REMAIN IN PLACE WITH SLOWING VEERING
FLOW TO MORE ESE IN THE AFTN AS CENTER OF HI PRES IN ONTARIO DRIFTS
TO THE E. WITH COLD WEDGE GETTING A BIT MORE SHALLOW...SUSPECT
LINGERING -DZ/-FZDZ WL BE MORE TIED TO UPSLOPE FLOW OVER THE NCNTRL
WHERE THERE WL BE ADDITIONAL MOISTENING OFF LK SUP. EXPECT LTL
DIURNAL TEMP RISE WITH LINGERING LO CLD OVC.
.LONG TERM /TUES NIGHT THROUGH NEXT MONDAY/...
ACTIVE MID TERM PORTION OF THE FORECAST...WITH A LOW PRESSURE SYSTEM
MOVING THROUGH THE AREA AROUND MID WEEK AND PROVIDING A WINTRY MIX
OF PCPN.
TUES NIGHT...UPPER RIDGE AXIS WILL BE SHIFTING E OF THE CWA THROUGH
THE NIGHT. SHOULD KEEP MUCH OF THE AREA DRY...ALTHOUGH PERSISTANT
LOW CLOUDS WILL BE COVERING MUCH OF THE AREA. WITH INCREASING
ISENTROPIC ASCENT AROUND THE 280 SFC AND DRY AIR ABOVE
5KFT...WOULDN/T BE SURPRISED IF THE SWRN HALF OF THE CWA EXPERIENCES
SOME DZ/FZDZ...SO HAVE PUT THE MENTION IN FOR MUCH OF THE NIGHT.
TRANSITIONED TO A RA/SN MIX ALONG THE WI BORDER OVERNIGHT...AS THE
280-300K ISENTROPIC ASCENT BEGINS TO MOVE INTO THE AREA. WITH THE
MOISTURE EATING AWAY AT THE DRY AIR...EXPECT THE DZ/RA TO QUICKLY
TRANSITION TO MAINLY SNOW ALONG THE BORDER AS ICE BECOMES PRESENT
AND THERE IS A NEARLY ISOTHERMAL LAYER AT/BELOW 0C FROM THE SFC TO
6KFT.
WITH THE MAIN TROUGH STILL WELL TO THE SW IN THE FOUR CORNERS
REGION...WEAK SHORTWAVE ENERGY WILL BE EJECTING NE TOWARDS THE AREA
ON WED. THIS WILL PUSH A WEAK LOW PRESSURE TROUGH ACROSS THE CWA
THROUGH THE DAY. BEST CHANCES OF PCPN ARE S AND E...CLOSER TO THE
MAIN PUSH OF THE SHORTWAVE...ALONG WITH H850-700 WAA AND ISENTROPIC
ASCENT. THIS AREA OF PCPN SHOULD QUICKLY MOVE NE THROUGH THE CWA
DURING THE MORNING AND EARLY AFTN AND LEAD TO A SLIGHTLY DRIER
PERIOD OVER THE W IN THE LATE AFTN BEFORE THE NEXT WAVE AFFECTS THE
AREA. DIFFICULTY IN THE FCST COMES FROM PCPN TYPE...AS THERE COULD
BE A MIXED BAG WITH THE PASSAGE OF THE SYSTEM. SOUNDINGS CONTINUE TO
SHOW A NEARLY ISOTHERMAL 0C LAYER FROM SFC TO 7KFT FOR THE
CENTRAL/WRN PORTIONS OF THE AREA...WHICH WOULD SUPPORT SNOW IN THE
MORNING. THEN AS SRLY WINDS INCREASE THROUGH THE DAY...LLVL TEMPS
LOOK TO RISE AND LEAVE THE LOWEST 2-4KFT ABOVE FREEZING /TOWARDS
2-3C/. AT THAT SAME TIME...THE DEEP MOISTURE EXITS THE AREA AND
THERE WILL LIKELY BE LITTLE/NO ICE POTENTIAL IN THE CLOUDS...SO HAVE
WENT MAINLY RAIN...WITH JUST A MENTION OF SNOW OVER THE N. MAY END
UP BEING JUST A -RA/DZ SITUATION IN THE LATE AFTN BEFORE NEXT WAVE
ARRIVES.
MAIN SHORTWAVE FROM THE SW FLOW ARRIVES ON WED NIGHT OVER THE ERN
CWA...WHICH MODELS RESPOND TO BY INTENSIFYING THE LOW OVER THE UPPER
GREAT LAKES. AT THE SAME TIME...NRN STREAM SHORTWAVE BEGINS TO ENTER
THE NRN PLAINS AND PHASES WITH THE SRN STREAM. MODELS HAVE A
NOTORIOUSLY TOUGH TIME WITH THESE EVENTS AND IT APPEARS THAT IT
CONTINUES WITH THIS SITUATION. ISSUES APPEAR WITH THE
TIMING/STRENGTH OF THE NRN STREAM WAVE...WHICH AFFECTS
INTENSITY/TRACK OF LOW. TRENDS IN THE GFS/ECMWF OVER THE LAST DAY OR
TWO HAVE BEEN FOR A WEAKER LOW TO TRACK ACROSS THE FAR ERN CWA WITH
A WEAKER NRN STREAM WAVE. WILL FOLLOW THAT TREND FOR THE WED NIGHT
AND THURS FORECAST...WITH AN EMPHASIS ON THE HPC PREFERRED GFS.
THEREFORE...HAVE THE HIGHEST POPS /80 PLUS/ OVER THE ERN HALF OF THE
CWA WITH THE BEST FORCING/MOISTURE. EXPECT THIS TO BE MAINLY RAIN
OVER THE EAST HALF...BUT IF THE ECMWF ENDS UP BEING CORRECT THERE
COULD BE SOME MIXING LATE.
FCST IS A LITTLE MORE TRICKY OVER THE W...SINCE IT IS ON THE FRINGE
OF THE BEST DEEP MOISTURE AND FORCING. IF PCPN OCCURS...HAVE A
FEELING THAT POTENTIAL FOR ICE IN THE CLOUDS IS LIMITED. HAVE
TRENDED TOWARDS MORE OF A RA SITUATION UNTIL THE COLDER AIR ARRIVES
TOWARDS DAYBREAK THURSDAY. DEPENDING ON HOW QUICKLY TEMPS FALL
DURING THE NIGHT AND INTO THURS MORNING...COULD SEE A PERIOD OF FZDZ
BEFORE TURNING TO ALL SNOW DURING THE MORNING.
THE LOW SHOULD THEN INTENSIFY OVER QUEBEC ON THURS...AS THE
SHORTWAVES PHASE. WITH SFC HIGH OVER THE NRN PLAINS AND JUST E OF
THE CANADIAN ROCKIES...EXPECT NW WINDS AND H850 TEMPS NEAR -12C TO
LEAD TO AT LEAST SOME LES DEVELOPING. INVERSION HEIGHTS AROUND
6-8KFT GIVES A DECENT CLOUD DEPTH...BUT WITH BEST FORCING BELOW THE
DGZ WILL LIMIT SNOW GROWTH. OPTED TO BUMP POPS UP HEADING INTO THE
AFTN...AS MORE FAVORABLE CONDITIONS FOR LES ARRIVE...ESPECIALLY
SINCE THE NRN CWA SHOULD BE SEEING WRAP AROUND MID-LVL MOISTURE FROM
THE LOW. FINALLY...SHOULD BE A BREEZY DAY ON THURS...WITH GUSTS
ALONG THE ERN LK SUPERIOR SHORELINE APPROACHING 40MPH.
DAYS 4 THROUGH 7 /THURS NIGHT THROUGH NEXT MONDAY/...
OVERALL...GOOD AGREEMENT IN THE EXTENDED MODELS ON THE OVERALL
PATTERN FOR THE EXTENDED PERIOD. ON THURS NIGHT...UPPER TROUGH WILL
BE PUSHING THROUGH THE AREA AND DROPPING H850 TEMPS TOWARDS -14C.
SHOULD STILL BE SOME MID-LVL MOISTURE OVER THE E BEFORE THE MOISTURE
EXITS THE AREA ON FRI AS THE INVERSION HEIGHTS FALL TOWARDS 5KFT
WITH HIGH PRESSURE RIDGE MOVING OVER THE WRN CWA. THUS...LES
INTENSITY SHOULD HIT IT/S PEAK THURS NIGHT...AS SHOWN IN LES
PARAMETER...BEFORE DIMINISHING IN INTENSITY THROUGH FRI. ONLY MADE
MINOR TWEAKS UP TO THE POPS OVER THE EAST AND THEN BUMPED UP TO HIGH
END CHANCE AND LOW LIKELY/S OVER THE NW WIND SNOW BELTS OVER THE
WEST FOR THURS NIGHT INTO FRI...ALTHOUGH THE CHANCES WILL DIMINISH
OVER THE W IN THE AFTN. IN ADDITION...WEAK SHORTWAVE ON FRI COULD
BRING SOME MID CLOUDS.
SFC HIGH PRESSURE RIDGE WILL QUICKLY MOVE EAST OF THE AREA ON FRI
NIGHT...WITH MODELS CONSISTENT ON A SHORTWAVE MOVING THROUGH THE
UPPER MISS VALLEY ON SAT. THIS WAVE WILL LIKELY DIVE S OF THE
CWA...AND CARRY THE BEST MOISTURE AND H850-500 Q-VECTOR CONV WITH
IT. OTHER THAN LINGERING LES OVER THE NW FAVORED LOCATIONS OVER THE
E IN THE MORNING BEFORE WIND SHIFT TO THE SW...WILL KEEP THE REST OF
THE CWA DRY.
UPPER RIDGE MOVING THROUGH SUNDAY...WITH H850 TEMPS RISING TOWARDS
1-4C. SHOULD LEAD TO ANOTHER WARM SUNDAY ACROSS THE AREA...BUT MAY
NOT BE QUITE AS WARM AS YESTERDAY/S HIGHS. DID BUMP UP TEMPS FROM
THE CONSENSUS OVER THE DOWNSLOPE AREAS NEAR LK SUPERIOR INTO THE
UPPER 30S. NEXT TROUGH WILL AFFECT THE AREA SUN NIGHT INTO
MON...BRINGING ANOTHER CHANCE OF PCPN TO THE AREA. DIFFERENCES IN
HOW AMPLIFIED THE TROUGH IS...ALONG WITH MOISTURE RETURN FROM THE
GULF...SO WILL LEAVE POPS AT SLIGHT/CHANCES.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
EXPECT PREDOMINANT IFR/LIFR CONDITIONS AT ALL 3 SITES THIS FCST
PERIOD WITH MOIST SW FLOW AHEAD OF A SLOW MOVING COLD FNT APRCHG FM
THE N. ALTHOUGH THE FNT WILL SINK SLOWLY S OVER THE FA LATER TDAY/
TNGT...SHALLOW INFLUX OF COLD AIR FM THE N THAT SHARPENS LLVL INVRN
WL MAINTAIN THE LO CLDS. THE BEST CHC FOR IMPROVEMENT TO MVFR WL BE
AT CMX...AS SOME LLVL DRYING BEHIND THE FNT MIGHT IMPACT THE
KEWEENAW WITH LESS OF AN UPSLOPE WIND COMPONENT AT TIMES TNGT. SOME
-FZDZ MAY IMPACT ALL 3 SITES AT TIMES WHEN THE LLVL WINDS ARE
UPSLOPE.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL PERSIST INTO EARLY WED AS A
LOW PRESSURE TROUGH SLOWLY SLIDES ACROSS LK SUPERIOR. WINDS BECOME
MORE SOUTHERLY AS ANOTHER LO PRES SYSTEM DEVELOPING IN THE PLAINS
BEGINS TO LIFT TOWARD THE UPPER GREAT LAKES. SE WINDS AHEAD OF THIS
LO MAY INCREASE TO 25 KTS ESPECIALLY OVER THE E HALF ON WED. THE
MAIN HAZARD WILL BE AFTER THE LOW MOVES TOWARD QUEBEC ON THU...WHEN
NW GALES IN ITS WAKE ENHANCED BY THE ARRIVAL OF VERY COLD AIR/MIXING
WILL PREVAIL. EXPECT THESE STRONG WINDS TO DIMINISH ON FRI WITH THE
SLOW APPROACH OF HI PRES. A STRONGER WSW FLOW WILL REDEVELOP ON SAT
AFTER THIS HI SHIFTS TO THE SE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 AM EST MON DEC 12 2011
UPDATED AVIATION DISCUSSION FOR 06Z TAFS
.SYNOPSIS...
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS
NAMERICA WITH NRN BRANCH RDGING BLDG INTO THE UPR GRT LKS. THESE
RISING HGTS...WITH 00Z-12Z H3 RISES UP TO 150M AT APX...ARE BEING
FORCED BY VIGOROUS WAD IN THE STRONG WSW FLOW /12Z H85 WIND SPEED AT
INL WAS 50KT/ BTWN SFC-H85 HI PRES IN THE MID ATLANTIC STATES AND LO
PRES JUST N OF THE BORDER MOVING E INTO NW ONTARIO THAT IS
ASSOCIATED WITH A SHRTWV NEAR LK WINNIPEG. THIS STRONG WAD HAS
PUSHED H85 TEMPS IN THE UPR MS VALLEY/GREAT LKS TO UNSEASONABLY HI
LVLS...WITH 12Z H85 TEMPS AT INL/MPX UP TO 7C VS 0C AT APX AND 3C AT
GRB TOWARD THE RETREATING COLD AIR. LO CLDS OVER THE E HALF OF THE
CWA THAT FORMED AS THIS WARMER AIR PUSHED OVER MORE RESILIENT NEAR
SFC COLD AIR IN THE PRESENCE OF RADIATIONAL COOLING LAST NGT ARE
ONLY GRDLY DISSIPATING EARLY THIS AFTN. OTRW...THE OVERALL DRYNESS
OF THE LOCAL 12Z RAOBS IS ALLOWING A MOSUNNY DAY. BUT MORE LO CLDS
ARE PUSHING NEWD THRU IOWA TOWARD THE UPR MIDWEST IN THE SW LLVL
FLOW ARND THE HI IN THE MID ATLANTIC. A DISTURBANCE IN THE SRN
BRANCH FLOW IS NOW IN KANSAS AND MOVING NEWD AS WELL.
&&
.SHORT TERM DISCUSSION /TNGT AND MON/...
MAIN FCST CONCERNS THIS PACKAGE ARE LO CLD TRENDS AND THE POTENTIAL
FOR MIXED PCPN ON MON AS DISTURBANCE NOW IN KANSAS RIDES TO THE NE.
TNGT...EXPECT THE LINGERING LO CLDS OVER THE E TO BE GONE BY FCST
ISSUANCE...WITH MOCLR SKIES/WELL ABV NORMAL TEMPS DOMINATING.
ALTHOUGH THE LO CLDS HEADING NE FM IOWA ARE LIKELY TO MIX OUT WITH
DAYTIME TEMPS RISING INTO THE 30S/40S THIS AFTN...EXPECT THE ST/SC
TO REDVLP WITH LOSS OF DAYTIME HEATING AFT SUNSET. 12Z MODEL
GUIDANCE SHOWS THE HIER LLVL RH ARRIVING NEAR THE WI BORDER W OF IMT
THIS EVNG...SO EXPECT EXPANDING LO CLDS SW-NE. THE COMBINATION OF
THE LO CLDS/STEADY SW FLOW OF MILD AIR WL GREATLY REDUCE DIURNAL
FALL OF TEMPS...BUT MIN TEMPS WL STILL FALL BLO 32 EVERYWHERE.
LOCATIONS NEAR LK SUP WHERE THE SW FLOW DOWNSLOPES WL BE WARMEST.
OPTED TO RETAIN MENTION OF SOME -FZDZ OVER THE INTERIOR W LATE AWAY
FM THE DOWNSLOPING NEAR LK SUP AS SHALLOW MSTR INFLUX GROWS A BIT
DEEPER WITH SOME DPVA/OMEGA/DEEPER MSTR ADVCTN AHEAD OF APRCHG
KANSAS SHRTWV. BUT SINCE THE HIER RH WL REMAIN WELL BLO THE DGZ AND
STILL BE RELATIVELY SHALLOW /BLO ABOUT H85/...ANY PCPN SHOULD REMAIN
IN THE FORM OF SMALL WATER DROPLETS.
MON...COMBINATION OF ARRIVAL OF LO PRES TROF ATTENDANT TO SHRTWV/SFC
LO NOW IN NW ONTARIO...DEEPER MSTR FM THE SW...AND SHRTWV NOW IN
KANSAS/ACCOMPANYING DYNAMICS WL RESULT IN EXPANDING PCPN CHCS. THE
12Z NAM/GFS/LOCAL WRF-ARW RUNS ALL EXHIBIT THE HIEST QPF UP TO ARND
0.20 INCH OVER THE SE CWA...WHERE GFS SHOWS AN AXIS OF SHARPER H85-7
FGEN AND THE ALL MODELS INDICATE DEEPER MSTR/OMEGA EXTENDING THRU
THE DGZ. SO OPTED TO RETAIN GOING LIKELY POPS IN THIS AREA. PTYPE WL
BE A SGNFT CONCERN. SUSPECT ONLY -FZDZ/FLURRIES WL BE ARND EARLY
WITH RELATIVELY SHALLOW MSTR YET...BUT EITHER RA...SN...OR A MIX IS
MORE LIKELY BY THE AFTN AT LEAST OVER OVER THE SE HALF WITH DEEPER
MSTR/LARGER PCPN PARTICLES. FOR THE PAST SEVERAL RUNS...THE NAM HAS
BEEN WARMEST WITH LLVL TEMPS AND THUS INDICATES RA WL BE THE
PREDOMINANT PTYPE AT LEAST OVER THE SE. THE 12Z CNDN MODEL SUPPORTS
THIS WARMER RUN AS WELL. ALTHOUGH THE UNSEASONABLE WARMTH TDAY WOULD
SUG THESE MODELS ARE ON THE RIGHT TRACK...RELATIVELY DRY NATURE OF
THE AIRMASS/POTENTIAL FOR EVAP COOLING HINTS THE COOLER GFS/WRF-ARW/
09Z SREF ARE ON THE RIGHT TRACK. BLENDED IN THAT DIRECTION FOR LLVL
TEMPS FIELDS FOR NOW TO DETERMINE PTYES.
.LONG TERM /00Z TUESDAY THROUGH NEXT SUNDAY/...
MAIN FOCUS FOR THE EXTENDED IS WITH PTYPES AND CHANCES FOR FREEZING
PRECIP FROM MON NIGHT THROUGH WED MORNING...THEN WITH A SYSTEM
MOVING THROUGH WED NIGHT/THU.
A SFC TROUGH/FRONT WILL BE STALLED OVER UPPER MI FROM THE CENTRAL
PLAINS FROM THE START OF THE PERIOD MON NIGHT...THROUGH TUE. A WEAK
UPPER WAVE WILL BE MOVING THROUGH THE ERN CWA PRIOR TO 06Z
TUE...PRODUCING SOME RAIN EAST. THE HARDEST PART OF THIS FORECAST
PERIOD IS THAT SHALLOW MOISTURE WILL EXIST ALONG AND SOUTH OF THE
FRONT...WITH DRY MID LEVELS KEEPING ICE CRYSTALS FROM FORMING. THE
TEMP PROFILE WILL BE SUB-FREEZING THROUGH WEDNESDAY MORNING /EXCEPT
NEAR SFC TEMPS DURING THE DAY TUE/...WHICH WILL KEEP PRECIP WITH THE
DEEPER MOISTURE AND LIFT OVER THE EAST MON NIGHT AS SNOW...AND
DRIZZLE/FREEZING DRIZZLE DIFFERENTIATION ELSEWHERE WILL BE DEPENDENT
ON SFC TEMPS. AT THIS POINT...IT LOOKS LIKE THERE IS POTENTIAL FOR
UP TO A TENTH OF AN INCH OF ICE ACCUMULATION FROM 00Z TUE INTO TUE
MORNING...MAINLY OVER THE WEST HALF OF UPPER MI. SOME UNCERTAINTY
STILL EXISTS WITH HOW MUCH FREEZING DRIZZLE WILL FALL...AND WHERE
THE HEAVIEST AMOUNTS WILL BE.
ATTENTION THEN TURNS TO THE NEXT SYSTEM MOVING IN AS AN UPPER TROUGH
FROM CENTRAL CANADA EXTENDS OVER THE PLAINS AT 00Z THU...MOVES
ACROSS UPPER MI THU...THEN INTO QUEBEC FRI NIGHT. MODELS SEEM TO BE
COMING INTO BETTER AGREEMENT WITH THIS SYSTEM BUT THERE ARE STILL
SOME BIG DIFFERENCES BETWEEN THEM...AND THOSE DIFFERENCES PLAY A
HUGE ROLE IN THE FORECAST. THE GEM AND NAM LOOK ANOMALOUS WITH THE
SYSTEM...SO THEY WERE NOT USED. THE 11/00Z ECMWF...WHICH HAS SHOWN
BETTER RUN TO RUN CONTINUITY THAN THE GFS...HAS A DEEPER UPPER WAVE
CO-LOCATED WITH THE CLOSED SFC LOW THAN THE GFS. THE MAIN DIFFERENCE
BETWEEN THE MODEL STEMS FROM THE STRENGTH OF THE UPPER TROUGH MOVING
IN...WHICH LEADS TO /AMONG OTHER THINGS/ TIMING DIFFERENCES IN THE
LOW LEVELS. THE 11/12Z GFS BRINGS THE SFC LOW INTO THE CWA AROUND
06Z THU...WHILE THE 11/00Z ECMWF LAGS UNTIL AROUND 15Z THU. BOTH
MODELS BRING IN MID LEVEL TEMPS THAT WOULD LEAD TO LIQUID PRECIP
UNTIL THE LOW PASSES AND COLDER AIR COMES IN. SFC TEMPS WED NIGHT
WILL FALL TO AROUND 30F OVER THE WEST HALF OF UPPER MI...BUT SHOULD
STAY NEAR OR ABOVE FREEZING OVER THE EAST HALF. TEMPS OVER THE W
LOOK TO STAY NEAR OR ABOVE FREEZING THROUGH AROUND 03Z THU...AND
STAY THERE UNTIL MID TO LATE MORNING THU. THE GFS BRING THE BULK OF
THE SYNOPTIC QPF /EASILY GREATER THAN 0.25 INCHES IN SOME SPOTS FROM
BOTH THE ECMWF AND GFS/ BETWEEN 00Z AND 12Z THU...WHILE THE ECMWF IS
BETWEEN 12Z AND 18Z THU...SO REGARDLESS OF MODEL THERE IS POTENTIAL
FOR SIGNIFICANT FREEZING RAIN IF ALL THE INGREDIENTS COME TOGETHER.
IT NEEDS TO BE STRESSED AGAIN THAT THERE IS STILL A CONSIDERABLE
AMOUNT OF UNCERTAINTY WITH THIS SYSTEM...ESPECIALLY WITH THE SMALL
SCALE DETAILS NEEDED FOR FREEZING RAIN. DUE TO THE POTENTIAL FOR
SIGNIFICANT FREEZING RAIN ACCUMULATIONS...PAY EXTRA ATTENTION AND
KEEP UP TO DATE WITH LATER FORECASTS ON THIS SYSTEM.
MODELS ARE IN DECENT GENERAL AGREEMENT FROM FRI THROUGH SUN. NW
WINDS AND 850MB TEMPS FALLING TO AOB -12C BY AT LEAST 12Z FRI WILL
MAKE FOR POTENTIAL FOR LES...BUT DRY AIR IS ALSO MOVING IN. A SFC
RIDGE WILL MOVE THROUGH SAT AFTERNOON AND EAST BY LATE
SAT...BRINGING SWLY WINDS. SW FLOW BEHIND THE DEPARTING HIGH E AND
LOW PRESSURE W...ALONG WITH AN UPPER RIDGE BUILDING IN FROM THE
W...WILL LEAD TO 850MB TEMPS INCREASING TO AOA 0C BY LATE SUNDAY.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
LOW MVFR CIGS CONTINUE TO SPREAD ACROSS THE REGION THIS MORNING AND
WILL GRADUALLY LOWER TO IFR AT ALL THREE TAF SITES BY 10Z. CLOUD
PRODUCING LAYER IS QUITE SHALLOW SO DEVELOPMENT OF -DZ/FZDZ WILL BE
DELAYED UNTIL SOME DEEPER MOISTURE ARRIVES CLOSER TO 12Z. NOT
CONFIDENT ON THE DEVELOPMENT OF -FZDZ AS SFC TEMPERATURE TRENDS
WARMER THAN BUFKIT SOUNDINGS BY A FEW DEGREES. ONCE TROUGH SWINGS
THOUGH THE AREA EXPECT BETTER LIFT/FORCING TO PRODUCE LIGHT SNOW
DURING THE DAYTIME HOURS. KSAW TO HAVE A LITTLE WARMER TEMPERATURE
PROFILE AND SHOULD SEE -RASN IN THE AFTERNOON. AREAS OF SNOW
EXPECTED OVER ALL THREE SITES BY 0Z TUESDAY AS COLDER AIR FILTERS IN.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT SW WINDS UP TO 30 KTS LATE THIS AFTN TO DIMINISH TONIGHT WITH
THE APPROACH OF A LO PRES TROF AND WEAKER PRES GRADIENT. ALTHOUGH
THERE WILL BE A WSHFT TO THE N FOLLOWING THE PASSAGE OF THIS TROF ON
MON...RELATIVELY LIGHT WINDS UNDER 20 KTS WILL PERSIST INTO WED BUT
SLOWLY VEER TO THE S AS A LO PRES SYSTEM DEVELOPING IN THE PLAINS
BEGINS TO MOVE NE TOWARD THE UPPER GREAT LKS. SE WINDS AHEAD OF THIS
LO MAY INCREASE TO 25 KTS ESPECIALLY OVER THE E HALF. THE MAIN
HAZARD WILL BE AFTER THE LO MOVES TO THE NE ON THU...WHEN NW GALES
IN ITS WAKE ENHANCED BY THE ARRIVAL OF VERY COLD AIR/MIXING WILL
PREVAIL. EXPECT THESE STRONG WINDS TO DIMINISH ON FRI WITH THE SLOW
APPROACH OF HI PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...RJT
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1144 AM CST MON DEC 12 2011
.AVIATION... /18Z TAF ISSUANCE/
FRONTAL BOUNDARY MEANDERS FROM NEAR A KDLH-KSTC-KFSD LINE AT TAF
ISSUANCE. THE FRONT WILL DRIFT SLOWLY SE TO KMSP-KRNH THIS
AFTERNOON AND THEN TURN STATIONARY. CEILINGS ALONG THE FRONT ARE
MAINLY IFR AND THIS SHOULD PERSIST THROUGH THE TAF PERIOD. THE
OUTER FRINGES...KAXN AND KEAU...ARE A CHALLENGE WITH MVFR FORECAST
TO BECOME IFR TONIGHT. THE LIGHT WINDS AND MOIST LOW LEVEL
CONDITIONS SHOULD ALLOW FOR VISIBILITIES NEAR 1 MILE ALONG WITH
CEILINGS IN THE 200-400 FOOT RANGE TUESDAY MORNING. THE FLOW WILL
SLOWLY BECOME SOUTHEAST ON TUESDAY WITH RAIN ARRIVING LATE IN THE
DAY FOR KRWF AND KMSP. THE RAIN WILL SPREAD INTO KSTC...KRNH AND
KEAU TUESDAY EVENING. TEMPERATURES LOOK WARM ENOUGH THROUGH THE
NIGHT FOR RAIN AT THESE LOCATION. KAXN MAY BE A PROBLEM EARLY
TUESDAY EVENING WITH SOME POTENTIAL FOR FREEZING RAIN.
KMSP...CEILINGS BETWEEN 010-015 EARLY THIS AFTERNOON THEN DROPPING
BELOW 010 LATE IN THE AFTERNOON AS A FRONTAL BOUNDARY SETTLES
OVERHEAD. NOT CONFIDENT THE IFR CEILINGS WILL LIFT IN THE 24-30
HOUR PORTION OF THE TAF AND KEPT THEM IN. HOWEVER...DID ALLOW FOR
MVFR VISIBILITY TO DEVELOP LATE TUESDAY MORNING ONWARD.
&&
.DISCUSSION... /ISSUED 449 AM CST MON DEC 12 2011/
SUMMARY...STILL A CONCERN FOR SOME SLICK ROADS IN WESTERN
WISCONSIN...BUT OVERALL FREEZING DRIZZLE WILL NOT BE MUCH OF A
FACTOR THIS MORNING. MIXED PRECIPITATION IS EXPECTED TUESDAY NIGHT
THROUGH WEDNESDAY...BUT WE SHOULD SEE MOSTLY RAIN IN THE TWIN
CITIES METRO.
ALL THE AIRPORT OBSERVATIONS THIS MORNING RANGING BETWEEN 34-39
DEGREES IN MN AND WI. TEMPERATURES HAVE BEEN STEADY ALL NIGHT...SO
DON`T EXPECT MUCH OF A CHANGE THROUGHOUT THE MORNING HOURS. MADE
SOME CALLS TO COUNTIES IN WESTERN WI THIS MORNING. THERE HAVE
BEEN SOME SLICK SPOTS ON ROADS IN RUSK...PRICE...AND TAYLOR
COUNTIES THIS MORNING. EVEN WITH THE AIR TEMPERATURE ABOVE
FREEZING...ROAD PAVEMENT TEMPERATURES ARE RANGING BETWEEN 30-33
DEGREES GIVEN THE FROST IN THE GROUND. UNTREATED ROADS ARE SLICK
WHERE PRECIP IS FALLING IN WESTERN WI. SO FAR EASTERN MN HAS
REMAINED MAINLY DRIZZLE FREE AND TEMPERATURES IN MN ARE A COUPLE
DEGREES WARMER...SO THE SKIN TEMP ON THE ROADS MAY ALSO BE JUST
ABOVE FREEZING. WE`LL LET THE CURRENT FREEZING RAIN ADVISORY IN WI
RIDE FOR NOW AND THE 15Z EXPIRATION IS STILL REASONABLE AT THIS
TIME. 06-09Z RUNS OF THE HRRR HAVE BEEN HANDLING THE CURRENT LIGHT
PRECIP QUITE WELL...EVEN HIGHLIGHTING THE MORE CELLULAR NATURE TO
THE LIGHT RAIN ECHOES IN ARX`S AREA OF SOUTHWEST WI. THE HRRR DOES
SPREAD A MORE UNIFORM AREA OF LIGHT RETURNS FURTHER NORTHWEST INTO
EASTERN MN AND WESTERN WI BETWEEN 11-14Z AND LINGERS IT UNTIL THE
EARLY THIS AFTERNOON. AS A RESULT...HAVE KEPT REASONABLY HIGH POPS
AND MENTION OF DRIZZLE GOING FOR MOST OF THE DAY. THIS ALSO AGREES
WELL WITH THE SATURATION ON THE 280-295K ISENTROPIC SURFACES FROM
THE RUC AND NAM THIS MORNING.
REALLY DIDN`T CHANGE A WHOLE LOT FROM THE PREVIOUS FORECAST WITH
RESPECT TO THE MID WEEK SYSTEM. YESTERDAY`S FORECAST ALREADY
INTRODUCED 70-80% IN MANY LOCATIONS...AND HARD TO GO MUCH HIGHER
WITH THE 12.00Z ECMWF SHOWING A SLIGHTLY SLOWER TREND AND THE
LEADING WAVE OF PRECIP BRACKETING THE 12Z TIME FRAME WEDNESDAY
MORNING. IT`S BECOMING LESS LIKELY THAT WE`LL HAVE MUCH RAIN ON
THE FRONT SIDE OF THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY
MORNING. 925-850MB TEMPS JUST SEEM TO WARM TOO FAST WHEN THE
ISENTROPIC LIFT KICKS IN. 2M TEMPS ARE STILL NEAR FREEZING DURING
THIS TIME...WITH MOST OF THE GUIDANCE SHOWING 31-35 DEGREES BY
WEDNESDAY MORNING. MUCH LIKE TODAY...WITH AIR TEMPERATURES NEAR
FREEZING AND FROST IN THE GROUND...A LIGHT ICE ACCUMULATION IS
POSSIBLE ON UNTREATED SURFACES. HAVE INCLUDED A MIXTURE OF
RAIN/FREEZING RAIN IN THE FORECAST...AND EVENTUALLY TREND TOWARD
ALL RAIN BY WEDNESDAY AFTERNOON. THE ACTUALLY PV ANOMALY DOESN`T
SWING THROUGH AT THE BASE OF THE 500MB TROF UNTIL 06-12Z THURSDAY.
THE 12.00Z GFS AND ECMWF HAVE SOME SLIGHT TIMING DIFFERENCES WITH
STRENGTHENING AND PROPAGATION OF THE SURFACE REFLECTION BUT THE
OVERALL TRACK IS IN REASONABLE AGREEMENT...ALTHOUGH THE 12.06Z GFS
I SEE IS NOW COMING IN MUCH MORE AGGRESSIVE IN TERMS OF QPF. THE
06-12Z THURSDAY WINDOW IS LIKELY OUR BEST WINDOW FOR ACCUMULATING
SNOWFALL. IT ALL DEPENDS ON HOW FAST THE TEMPERATURE PROFILE
COLLAPSES AND WHERE THE DEFORMATION PRECIP SETS UP ACROSS
SOUTHEAST MN AND WESTERN WI.
OVERALL...THE MID WEEK SYSTEM AT LEAST HAS THE POTENTIAL TO BRING
THE MOST PRECIP WE`VE SEEN IN A COUPLE MONTHS...WHICH REALLY ISN`T
SAYING MUCH GIVEN HOW DRY IT`S BEEN. AFTER A FEW MORE MILD MID
DECEMBER TEMPERATURE DAYS...WE`LL GET A COOL DOWN FOR THURSDAY AND
FRIDAY...BUT HEIGHTS BUILD AGAIN FOR THE WEEKEND.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/CLF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
709 AM CST MON DEC 12 2011
.UPDATE...
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
SUMMARY...STILL A CONCERN FOR SOME SLICK ROADS IN WESTERN
WISCONSIN...BUT OVERALL FREEZING DRIZZLE WILL NOT BE MUCH OF A
FACTOR THIS MORNING. MIXED PRECIPITATION IS EXPECTED TUESDAY NIGHT
THROUGH WEDNESDAY...BUT WE SHOULD SEE MOSTLY RAIN IN THE TWIN
CITIES METRO.
ALL THE AIRPORT OBSERVATIONS THIS MORNING RANGING BETWEEN 34-39
DEGREES IN MN AND WI. TEMPERATURES HAVE BEEN STEADY ALL NIGHT...SO
DON`T EXPECT MUCH OF A CHANGE THROUGHOUT THE MORNING HOURS. MADE
SOME CALLS TO COUNTIES IN WESTERN WI THIS MORNING. THERE HAVE
BEEN SOME SLICK SPOTS ON ROADS IN RUSK...PRICE...AND TAYLOR
COUNTIES THIS MORNING. EVEN WITH THE AIR TEMPERATURE ABOVE
FREEZING...ROAD PAVEMENT TEMPERATURES ARE RANGING BETWEEN 30-33
DEGREES GIVEN THE FROST IN THE GROUND. UNTREATED ROADS ARE SLICK
WHERE PRECIP IS FALLING IN WESTERN WI. SO FAR EASTERN MN HAS
REMAINED MAINLY DRIZZLE FREE AND TEMPERATURES IN MN ARE A COUPLE
DEGREES WARMER...SO THE SKIN TEMP ON THE ROADS MAY ALSO BE JUST
ABOVE FREEZING. WE`LL LET THE CURRENT FREEZING RAIN ADVISORY IN WI
RIDE FOR NOW AND THE 15Z EXPIRATION IS STILL REASONABLE AT THIS
TIME. 06-09Z RUNS OF THE HRRR HAVE BEEN HANDLING THE CURRENT LIGHT
PRECIP QUITE WELL...EVEN HIGHLIGHTING THE MORE CELLULAR NATURE TO
THE LIGHT RAIN ECHOES IN ARX`S AREA OF SOUTHWEST WI. THE HRRR DOES
SPREAD A MORE UNIFORM AREA OF LIGHT RETURNS FURTHER NORTHWEST INTO
EASTERN MN AND WESTERN WI BETWEEN 11-14Z AND LINGERS IT UNTIL THE
EARLY THIS AFTERNOON. AS A RESULT...HAVE KEPT REASONABLY HIGH POPS
AND MENTION OF DRIZZLE GOING FOR MOST OF THE DAY. THIS ALSO AGREES
WELL WITH THE SATURATION ON THE 280-295K ISENTROPIC SURFACES FROM
THE RUC AND NAM THIS MORNING.
REALLY DIDN`T CHANGE A WHOLE LOT FROM THE PREVIOUS FORECAST WITH
RESPECT TO THE MID WEEK SYSTEM. YESTERDAY`S FORECAST ALREADY
INTRODUCED 70-80% IN MANY LOCATIONS...AND HARD TO GO MUCH HIGHER
WITH THE 12.00Z ECMWF SHOWING A SLIGHTLY SLOWER TREND AND THE
LEADING WAVE OF PRECIP BRACKETING THE 12Z TIME FRAME WEDNESDAY
MORNING. IT`S BECOMING LESS LIKELY THAT WE`LL HAVE MUCH RAIN ON
THE FRONT SIDE OF THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY
MORNING. 925-850MB TEMPS JUST SEEM TO WARM TOO FAST WHEN THE
ISENTROPIC LIFT KICKS IN. 2M TEMPS ARE STILL NEAR FREEZING DURING
THIS TIME...WITH MOST OF THE GUIDANCE SHOWING 31-35 DEGREES BY
WEDNESDAY MORNING. MUCH LIKE TODAY...WITH AIR TEMPERATURES NEAR
FREEZING AND FROST IN THE GROUND...A LIGHT ICE ACCUMULATION IS
POSSIBLE ON UNTREATED SURFACES. HAVE INCLUDED A MIXTURE OF
RAIN/FREEZING RAIN IN THE FORECAST...AND EVENTUALLY TREND TOWARD
ALL RAIN BY WEDNESDAY AFTERNOON. THE ACTUALLY PV ANOMALY DOESN`T
SWING THROUGH AT THE BASE OF THE 500MB TROF UNTIL 06-12Z THURSDAY.
THE 12.00Z GFS AND ECMWF HAVE SOME SLIGHT TIMING DIFFERENCES WITH
STRENGTHENING AND PROPAGATION OF THE SURFACE REFLECTION BUT THE
OVERALL TRACK IS IN REASONABLE AGREEMENT...ALTHOUGH THE 12.06Z GFS
I SEE IS NOW COMING IN MUCH MORE AGGRESSIVE IN TERMS OF QPF. THE
06-12Z THURSDAY WINDOW IS LIKELY OUR BEST WINDOW FOR ACCUMULATING
SNOWFALL. IT ALL DEPENDS ON HOW FAST THE TEMPERATURE PROFILE
COLLAPSES AND WHERE THE DEFORMATION PRECIP SETS UP ACROSS
SOUTHEAST MN AND WESTERN WI.
OVERALL...THE MID WEEK SYSTEM AT LEAST HAS THE POTENTIAL TO BRING
THE MOST PRECIP WE`VE SEEN IN A COUPLE MONTHS...WHICH REALLY ISN`T
SAYING MUCH GIVEN HOW DRY IT`S BEEN. AFTER A FEW MORE MILD MID
DECEMBER TEMPERATURE DAYS...WE`LL GET A COOL DOWN FOR THURSDAY AND
FRIDAY...BUT HEIGHTS BUILD AGAIN FOR THE WEEKEND.
&&
.AVIATION.../12Z TAF ISSUANCE/
PLENTY OF LOW LEVEL MOISTURE BEING ADVECTED IN FROM THE SOUTH
AHEAD OF A SLUGGISH COLD FRONT DRAPED OVER NRN MN INTO ERN SD
MAKING FOR WIDESPREAD LOW CLOUDS AND PATCHY REDUCED CIGS. WEAK
PRECIP ECHOES ARE BECOMING MORE PREVALENT ON KMPX RADAR THIS
MORNING...PRIMARILY SOUTH AND EAST OF KMSP WHERE PRECIP IS
EXPECTED TO REMAIN THROUGH THE DAY. NOT EXPECTING -FZDZ AS AIR
TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING...BUT WILL LOOK FOR
PERIODS OF -DZ THROUGH EARLY AFTN. EVEN IF PRECIP DOES NOT REACH
ANY OF THE TERMINALS...MVFR/IFR CIGS WILL BE A PRIMARY CONCERN
WITH MVFR VSBYS SECONDARY. LOW CLOUDS WILL REMAIN IN PLACE THROUGH
THE DAY. WINDS BETWEEN 5-10 KT WILL MAINLY MAKE FOR LOW STRATUS
WITH DECKS THROUGH EARLY AFTN IN THE LOWER RANGE OF MVFR ALTHOUGH
PERIODS OF IFR ARE POSSIBLE. BY THIS EVENING...IFR CIGS WILL BE
PREVALENT WITH MVFR VSBYS. AT TIMES...CIGS MAY DROP TO LIFR BUT
CONFIDENCE IS NOT HIGH ENOUGH ATTM TO GO THAT LOW WHEREAS
CONFIDENCE IS RATHER HIGH OF SEEING IFR...IF NOT LOWER...CIGS.
DEGRADED CONDITIONS WILL REMAIN THROUGH DAYBREAK TUESDAY MORNING.
MSP...MVFR CIGS WILL PREVAIL THROUGH LATE AFTN BUT THE 1700 FT
THRESHOLD WILL BE A TRICKY PROPOSITION TODAY. AM EXPECTING CIGS TO
WOBBLE BETWEEN 1500-1900 FT WHICH MAY CAUSE ISSUES WITH TRAFFIC
MANAGEMENT. AS FOR PRECIP THROUGH THE DAY...-FZDZ IS NOT EXPECTED
WITH A SHALLOW ENOUGH LOW LEVEL LAYER AND SFC TEMPS WELL ABOVE
FREEZING. THEREFORE...ANY PRECIP IS EXPECTED TO BE LIQUID AND NOT
A LOT AT THAT /ONLY UP TO A TENTH OF AN INCH ACCUMULATION/. MVFR
CIGS WILL PREVAIL THROUGH LATE AFTN THEN WILL LOOK FOR CIGS TO
DROP TO IFR WHICH WILL THEN PREVAIL TONIGHT THROUGH TUE MORNING.
LIFR CIGS ARE POSSIBLE DURING THE EARLY MORNING HOURS...BUT
CONFIDENCE NOT THAT HIGH ATTM FOR ITS INCLUSION.
OUTLOOK...MVFR CIGS MAY LINGER THROUGH TUESDAY AS THE FRONT
SETTLES NEAR THE IA/MN BORDER. COMPLEX SYSTEM MOVING SOUTHWEST TO
NORTHEAST ALONG THE FRONT TUE NIGHT THROUGH WED NIGHT WILL BRING
A VARIETY OF FROZEN AND/OR LIQUID PRECIPITATION WITH A HIGH
PROBABILITY OF DEGRADED FLIGHT CATEGORIES. VFR CONDITIONS RETURN
THU AND FRI AS HIGH PRESSURE RETURNS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR BARRON-
CHIPPEWA-EAU CLAIRE-RUSK.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
449 AM CST MON DEC 12 2011
.DISCUSSION...
SUMMARY...STILL A CONCERN FOR SOME SLICK ROADS IN WESTERN
WISCONSIN...BUT OVERALL FREEZING DRIZZLE WILL NOT BE MUCH OF A
FACTOR THIS MORNING. MIXED PRECIPITATION IS EXPECTED TUESDAY NIGHT
THROUGH WEDNESDAY...BUT WE SHOULD SEE MOSTLY RAIN IN THE TWIN
CITIES METRO.
ALL THE AIRPORT OBSERVATIONS THIS MORNING RANGING BETWEEN 34-39
DEGREES IN MN AND WI. TEMPERATURES HAVE BEEN STEADY ALL NIGHT...SO
DON`T EXPECT MUCH OF A CHANGE THROUGHOUT THE MORNING HOURS. MADE
SOME CALLS TO COUNTIES IN WESTERN WI THIS MORNING. THERE HAVE
BEEN SOME SLICK SPOTS ON ROADS IN RUSK...PRICE...AND TAYLOR
COUNTIES THIS MORNING. EVEN WITH THE AIR TEMPERATURE ABOVE
FREEZING...ROAD PAVEMENT TEMPERATURES ARE RANGING BETWEEN 30-33
DEGREES GIVEN THE FROST IN THE GROUND. UNTREATED ROADS ARE SLICK
WHERE PRECIP IS FALLING IN WESTERN WI. SO FAR EASTERN MN HAS
REMAINED MAINLY DRIZZLE FREE AND TEMPERATURES IN MN ARE A COUPLE
DEGREES WARMER...SO THE SKIN TEMP ON THE ROADS MAY ALSO BE JUST
ABOVE FREEZING. WE`LL LET THE CURRENT FREEZING RAIN ADVISORY IN WI
RIDE FOR NOW AND THE 15Z EXPIRATION IS STILL REASONABLE AT THIS
TIME. 06-09Z RUNS OF THE HRRR HAVE BEEN HANDLING THE CURRENT LIGHT
PRECIP QUITE WELL...EVEN HIGHLIGHTING THE MORE CELLULAR NATURE TO
THE LIGHT RAIN ECHOES IN ARX`S AREA OF SOUTHWEST WI. THE HRRR DOES
SPREAD A MORE UNIFORM AREA OF LIGHT RETURNS FURTHER NORTHWEST INTO
EASTERN MN AND WESTERN WI BETWEEN 11-14Z AND LINGERS IT UNTIL THE
EARLY THIS AFTERNOON. AS A RESULT...HAVE KEPT REASONABLY HIGH POPS
AND MENTION OF DRIZZLE GOING FOR MOST OF THE DAY. THIS ALSO AGREES
WELL WITH THE SATURATION ON THE 280-295K ISENTROPIC SURFACES FROM
THE RUC AND NAM THIS MORNING.
REALLY DIDN`T CHANGE A WHOLE LOT FROM THE PREVIOUS FORECAST WITH
RESPECT TO THE MID WEEK SYSTEM. YESTERDAY`S FORECAST ALREADY
INTRODUCED 70-80% IN MANY LOCATIONS...AND HARD TO GO MUCH HIGHER
WITH THE 12.00Z ECMWF SHOWING A SLIGHTLY SLOWER TREND AND THE
LEADING WAVE OF PRECIP BRACKETING THE 12Z TIME FRAME WEDNESDAY
MORNING. IT`S BECOMING LESS LIKELY THAT WE`LL HAVE MUCH RAIN ON
THE FRONT SIDE OF THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY
MORNING. 925-850MB TEMPS JUST SEEM TO WARM TOO FAST WHEN THE
ISENTROPIC LIFT KICKS IN. 2M TEMPS ARE STILL NEAR FREEZING DURING
THIS TIME...WITH MOST OF THE GUIDANCE SHOWING 31-35 DEGREES BY
WEDNESDAY MORNING. MUCH LIKE TODAY...WITH AIR TEMPERATURES NEAR
FREEZING AND FROST IN THE GROUND...A LIGHT ICE ACCUMULATION IS
POSSIBLE ON UNTREATED SURFACES. HAVE INCLUDED A MIXTURE OF
RAIN/FREEZING RAIN IN THE FORECAST...AND EVENTUALLY TREND TOWARD
ALL RAIN BY WEDNESDAY AFTERNOON. THE ACTUALLY PV ANOMALY DOESN`T
SWING THROUGH AT THE BASE OF THE 500MB TROF UNTIL 06-12Z THURSDAY.
THE 12.00Z GFS AND ECMWF HAVE SOME SLIGHT TIMING DIFFERENCES WITH
STRENGTHENING AND PROPAGATION OF THE SURFACE REFLECTION BUT THE
OVERALL TRACK IS IN REASONABLE AGREEMENT...ALTHOUGH THE 12.06Z GFS
I SEE IS NOW COMING IN MUCH MORE AGGRESSIVE IN TERMS OF QPF. THE
06-12Z THURSDAY WINDOW IS LIKELY OUR BEST WINDOW FOR ACCUMULATING
SNOWFALL. IT ALL DEPENDS ON HOW FAST THE TEMPERATURE PROFILE
COLLAPSES AND WHERE THE DEFORMATION PRECIP SETS UP ACROSS
SOUTHEAST MN AND WESTERN WI.
OVERALL...THE MID WEEK SYSTEM AT LEAST HAS THE POTENTIAL TO BRING
THE MOST PRECIP WE`VE SEEN IN A COUPLE MONTHS...WHICH REALLY ISN`T
SAYING MUCH GIVEN HOW DRY IT`S BEEN. AFTER A FEW MORE MILD MID
DECEMBER TEMPERATURE DAYS...WE`LL GET A COOL DOWN FOR THURSDAY AND
FRIDAY...BUT HEIGHTS BUILD AGAIN FOR THE WEEKEND.
&&
.AVIATION.../06Z TAF ISSUANCE/
WIDESPREAD MVFR CIGS WERE PREVALENT ALONG WITH FEW POCKETS OF IFR
CONDITIONS OVER SOUTH CENTRAL MN AT THIS TIME. SURFACE WINDS HAVE
STAYED UP FOR THE MOST PART ACROSS THE TAF SITES...KEEPING THE
BOUNDARY LAYER WELL MIXED. WATER VAPOR FROM THE SNOW MELT ACROSS THE
PARTS OF NORTHERN IOWA AND SOUTHERN MN...WAS ALSO KEEPING SURFACE
TEMPERATURES FROM LOWERING BELOW THE FREEZING MARK SO FAR. EXPECT
SOME PATCHY LIGHT DRIZZLE TO DEVELOP OVERNIGHT. LIGHT FREEZING
DRIZZLE APPARENTLY MORE LIKELY OVER PARTS OF WEST CENTRAL WISCONSIN
THAN OVER MN...BUT STILL SOMEWHAT OF CONCERN FOR AVIATION INTEREST
WITH NO DEICING EQUIPMENT THE REST OF TONIGHT AND MONDAY MORNING.
STRONG INVERSION ALOFT OVER THE TAF SITES...PRECIP SHOULD BE MAINLY
LIQUID THE REST OF THE DAY(MONDAY). AS THE COLD FRONT THAT IS DRAPED
OVER NORTHERN HALF OF MN...SLOWLY SAGS SOUTH DURING THE
PERIOD...EXPECT MORE WIDESPREAD IFR OR LIFR FLYING CONDITIONS
DEVELOPING OVER THE UPPER MIDWEST LATE IN THE DAY AND OVERNIGHT
MONDAY.
KMSP...MVFR CONDITIONS WILL PERSIST OVERNIGHT WITH CEILINGS OR
VISIBILITIES LOWERING BELOW 1000 FEET AGL AND 3 MILES IN PATCHY MIST
AND FOG. WEATHER CONDITIONS ARE EXPECTED TO LOWER AS A COLD FRONT
DIPS SOUTH LATE IN THE DAY MONDAY/MONDAY NIGHT WITH CEILING LOWERING
BELOW 1000 FEET AND VISIBILITIES 3 MILES IN FOG.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR BARRON-
CHIPPEWA-EAU CLAIRE-RUSK.
&&
$$
CLF/JVM
AREA FORECAST DISCUSSION...UPDATED
NWS HASTINGS NE
1128 AM CST MON DEC 12 2011
.UPDATE...SHORT UPDATE EARLIER THIS MORNING FOR AFTERNOON WEATHER
AND LESS FOG ACROSS THE AREA. CHALLENGE THIS AFTERNOON IS THE
NORTHWEST/WEST FRINGES OF THE NEBRASKA COUNTIES WHERE SKIES CLEARED
AND TEMPERATURES TANKED...AND LOCALLY DENSE FOG HAD SET IN. HARD TO
GAGE JUST HOW MUCH WARMING THEY MAY GET WITH SNOW STILL ON THE GROUND
BUT ALSO SOME PERIODS OF SUNSHINE. ELSEWHERE...CLOUDS SKIES WILL
HOLD FORM AND TEMPERATURES IN THE 30S TO LOWER 40S. NORTHWEST WINDS
BEHIND WEAK SURFACE BOUNDARY MAY ALLOW FOR TEMPERATURES TO SLIP A FEW
DEGREES LATER THIS AFTERNOON ACROSS THE NORTHERN SECTIONS OF THE
FORECAST AREA.
THERE IS INCREASING CONTINUITY AMONGST MORNING MODEL RUNS THAT THE
PERIOD OF MAIN CONCERN FOR ICING WILL BE AFTER 08Z TONIGHT WITH
INITIAL FREEZING DRIZZLE...AND THEN FROM ABOUT 12Z TO 18Z TUESDAY
ACROSS THE NORTHWEST PART OF THE CWFA IN TERMS OF FREEZING RAIN.
THIS WILL BE THE FOCUS THIS AFTERNOON IN THE SHORT TERM.
&&
.AVIATION...MVFR TO IFR CONDITIONS WILL PREVAIL THROUGHOUT THIS
FORECAST PERIOD FOR KGRI. THE MAIN ISSUE WILL BE LATER TONIGHT
WHEN NEAR LIFR CEILINGS/VISIBILITIES WILL START TO SET UP ALONG
WITH SOME LIGHT FREEZING DRIZZLE AFTER ABOUT 08Z. EVENTUALLY THIS
WILL TURN TO MORE OF A LIGHT FREEZING RAIN SHORTLY AFTER SUNRISE
TUESDAY...BUT TEMPERATURES WILL WARM BY NOON TO HAVE RAIN START TO
BE MORE PROMINENT. WINDS WILL BE LIGHT...BUT SHIFTING TO THE NORTH
AND EVENTUALLY EAST.
&&
.PREV DISCUSSION... /ISSUED 726 AM CST MON DEC 12 2011/
AVIATION...12Z KGRI TAF. GENERALLY POOR AVIATION CONDITIONS ARE
EXPECTED AT KGRI FOR MUCH OF THE NEXT 24 HOURS. THE WIDESPREAD LOW
LEVEL STRATUS ACROSS THE REGION THIS MORNING IS EXPECTED TO
THICKEN OVER THE NEXT FEW HOURS...WITH LOW MVFR CIGS AND VSBY
LIKELY TO RETURN AND PERSIST AT KGRI THROUGH ABOUT 12/18Z.
CEILINGS AND VSBYS WILL EVENTUALLY IMPROVE TO MORE ELEVATED MVFR
LEVELS BY EARLY AFTERNOON...HOWEVER THIS MINOR IMPROVEMENT IS
EXPECTED TO BE VERY SHORT LIVED...WITH LOW MVFR...OR EVEN
IFR...VISIBILITIES AND CEILINGS EXPECTED TO DEVELOP AFTER THE SUN
SETS. IN ADDITION...AN APPROACHING SYSTEM WILL BRING THE CHANCE
FOR SOME LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN LATE IN THE
TAF PERIOD...BUT KEPT AS -DZ FOR CURRENT TAF ISSUANCE AS ONSET IS
VERY NEAR THE END OF CURRENT VALID PERIOD. LIGHT SOUTHERLY WINDS
NEAR 10 KTS THIS MORNING WILL SHIFT MORE WESTERLY THROUGH THE
PERIOD...EVENTUALLY TRANSITIONING FULL CIRCLE OVERNIGHT...BECOMING
NORTHEASTERLY OVERNIGHT TONIGHT.
PREV DISCUSSION... /ISSUED 556 AM CST MON DEC 12 2011/
SHORT TERM...THROUGH WEDNESDAY NIGHT. PLENTY OF ISSUES TRYING TO
NAIL DOWN PRECIP TYPES/AMOUNTS ETC. DURING THE NEXT FEW DAYS HAS
LED TO A CHALLENGING NIGHT ON THE FORECAST DESK. MAIN CONCERNS
DURING THE NEXT FEW DAYS INVOLVE WHETHER THE CWA WILL SEE ANY
APPRECIABLE RISK OF GENERALLY LIGHT ICING...ALTHOUGH GENERAL
WARMING TREND OF SURFACE TEMPERATURES DURING LAST SEVERAL MODEL
RUNS SEEMS TO BE CONFINING THE MAIN RISK ZONE TO A SMALLER AND
SMALLER AREA OF THE NORTHWEST CWA.
STARTING OFF EARLY THIS MORNING...BEEN AN INTERESTING NIGHT FROM A
TEMP PERSPECTIVE...AS WIDESPREAD STRATUS AND SOUTHERLY BREEZES
HAVE KEPT READINGS SEVERAL DEGREES ABOVE FREEZING ACROSS THE VAST
MAJORITY OF THE CWA...RESULTING IN A SOMEWHAT RARE MODEST
OVERNIGHT SNOW MELT FOR THIS TIME OF YEAR. MAIN CONCERNS
OVERNIGHT...AND THROUGH THE NEXT FEW/SEVERAL HOURS ARE ACROSS THE
FAR WESTERN PORTIONS OF THE CWA...WHERE WEB CAMS AND AUTOMATED OBS
HAVE SUGGESTED THAT THERE IS A NARROW CORRIDOR OF LOCALLY DENSE
FOG LIKELY LURKING NEAR/WITHIN WESTERN PORTIONS OF DAWSON...GOSPER
AND FURNAS COUNTIES. THIS FOG IS GENERALLY TIED TO THE EDGE OF THE
EXPANSIVE LOW CLOUD DECK COVERING MUCH OF THE REGION...ALONG WHICH
THERE IS QUITE A TEMP GRADIENT INCLUDING A STRIKING 26 DEGREE
DIFFERENCE BETWEEN HOLDREGE AND MCCOOK AT 11Z. WITH ANY DENSE FOG
SEEMINGLY AFFECTING SUCH A SMALL PORTION OF THE AREA...HAVE OPTED
AGAINST AN ADVISORY...BUT HAVE IT MENTIONED IN THE GRIDS AND ALSO
IN THE HWO. AS FOR ANY LIGHT FREEZING DRIZZLE CONCERNS FROM 12-24
HOURS AGO...THESE HAVE APPARENTLY BEEN AVOIDED FOR NOW GIVEN THE
SEASONABLY MILD OVERNIGHT TEMPS...AND EVEN PLAIN LIGHT DRIZZLE HAS
APPARENTLY BEEN QUITE SCANT OVERNIGHT ACROSS THE AREA.
A QUICK LOOK AT 11Z OBJECTIVE SURFACE ANALYSIS PLACES A WEAK
TROUGH AXIS NEAR THE EDGE OF THE STRATUS/NEAR THE WESTERN EDGE OF
THE CWA...WITH STEADY SOUTH BREEZES 5-15 MPH AFFECTING NEARLY ALL
OF THE CWA TO THE EAST OF THIS AXIS. ALOFT...WATER VAPOR IMAGERY
AND SHORT TERM MODEL DATA CONFIRM THE PRESENCE OF A FAIRLY WEAK
MID LEVEL SHORTWAVE STARTING TO DEPART EASTERN NEB TO THE EAST-
NORTHEAST...WITH LOW STRATUS CEILINGS ACTUALLY RISING QUITE A BIT
IN MUCH OF THE CWA IN ITS WAKE. UPSTREAM...THE MAIN LARGE-SCALE
TROUGH OF CONCERN IS STILL CENTERED NEAR THE PACIFIC COAST.
FOR TODAY...THE MAIN CONCERN THIS MORNING IS WHETHER ANY DENSE
FOG ALONG THE STRATUS EDGE CAN WORK A BIT FARTHER EASTWARD INTO
THE AREA. FOR NOW HAVE DENSE FOG MENTION CONFINED SOLELY TO PARTS
OF DAWSON...GOSPER...FURNAS. AS FOR SKY COVER...LATEST SUGGESTIONS
FROM HRRR MODEL IS THAT STRATUS SHOULD HOLD FIRM ACROSS MOST OF
THE CWA THROUGH THE DAY...ALTHOUGH ROUGHLY THE WESTERN 1/4 OF THE
AREA COULD SEE SOME PARTIAL CLEARING ALONG/WEST OF THE WEAK LOW
LEVEL TROUGH AXIS. DEFINITELY SOMETHING TO WATCH. TEMP
WISE...GIVEN THE WARM START RAISED HIGHS ROUGHLY 3-4 DEGREES OVER
PREVIOUS FORECAST MOST AREAS...AND POSSIBLY NOT ENOUGH. WILL AIM
FOR A GRADIENT FROM MID 30S NORTHWEST TO LOW 40S SOUTHEAST...AND
MAYBE EVEN UPPER 40S IN THE MITCHELL COUNTY KS AREA. LIMITED LIFT
SHOULD KEEP ANY POTENTIAL DRIZZLE AT BAY TODAY.
TONIGHT...MAIN CHANGE WAS TO RAISE LOW TEMPS A NOTABLE 4-8 DEGREES
OVER PREVIOUS FORECAST MOST AREAS...ALTHOUGH THIS IS VERY
DEPENDENT ON WIDESPREAD CLOUD COVER HOLDING FIRM. ASSUMING THIS
OCCURS...AM NOW TALKING A GRADIENT FROM LOW-MID 20S NORTHWEST TO
LOW-MID 30S SOUTHEAST. WITH LIGHT WINDS...CANNOT RULE OUT PATCHY
TO AREAS OF FOG OVERNIGHT...BUT NOTHING THAT CAN REALLY BE PINNED
DOWN FOR POSSIBLE DENSE DEVELOPMENT. KEPT THEME FROM PREVIOUS
FORECAST INTACT...WITH SLIGHT CHANCE OF DRIZZLE IN THE SOUTH
BEFORE MIDNIGHT...AND THEN BETTER CHANCES FOR LIGHT MEASURABLE
PRECIP AFTER MIDNIGHT MAINLY ACROSS THE SOUTHERN HALF OF THE CWA
AS FIRST LEAD SHORTWAVE MOVES INTO THE REGION. COULD SEE LIGHT
ICING MAINLY ACROSS NEB ZONES...BUT NOT ANTICIPATING MAJOR ISSUES
AND DAY SHIFT SHOULD BE ABLE TO BETTER PIN DOWN THE SURFACE TEMP
TREND.
TUESDAY...RAISED POPS 10-20 PERCENT OVER PREVIOUS FORECAST MAINLY
FOR THE AFTERNOON...WITH 60-80 POPS NOW OVER MUCH OF THE
CENTRAL/SOUTHEAST CWA. ALSO RAISED HIGHS 2-4 DEGREES MOST
AREAS...WITH ANY RISK FOR FREEZING RAIN DURING THE DAY LARGELY
CONFINED TO LOCATIONS NORTHWEST OF A GREELEY-ELWOOD LINE...AND
EVEN THIS AREA MAY BE OVERDONE IF THE ECMWF/GFS HAVE A DECENT
HANDLE ON SURFACE TEMPS. HAVE HIGHS RANGING FROM THE MID 30S
NORTHWEST TO LOW-MID 40S IN KS ZONES AND AROUND HEBRON.
TUESDAY NIGHT...FORCING FROM INCOMING MID LEVEL WAVE AND UPPER
LEVEL JET INCREASE...AND HAVE AT LEAST 50 POPS CWA-WIDE...AND
LIKELIES MAINLY ACROSS THE EASTERN 1/3. COULD EASILY SEE SLIGHTLY
RISING/AT LEAST STEADY TEMPS THROUGH THE NIGHT...WITH ANY MENTION
OF FREEZING RAIN NOW CONFINED MAINLY TO VALLEY...SHERMAN...DAWSON
COUNTIES. WITH BOTH THE NAM/GFS PULLING AT LEAST 100-300 J/KG OF
MUCAPE INTO THE CWA...AND THE SREF PROBABILITIES INCREASING FOR
GENERAL THUNDER...EVEN INTRODUCED AN ISOLATED THUNDER MENTION TO
ROUGHLY THE SOUTHEAST 1/2 OF THE CWA OVERNIGHT...WHICH MAY OR MAY
NOT EXTEND INTO WED AS WELL BUT DON/T HAVE IT IN THERE YET.
WED INTO WED NIGHT...THE MAIN MID LEVEL WAVE MOVES DIRECTLY
THROUGH THE REGION...WITH ALL PRECIP LIKELY OVER BY MIDNIGHT. HAVE
LIKELY POPS ALREADY IN PLACE ACROSS ROUGHLY THE EASTERN 1/2 OF THE
CWA ALREADY...WHICH MAY NEED EXTENDED WESTWARD IN LATER UPDATES.
UNLESS MODELS SUDDENLY START TRENDING COLDER...THIS SHOULD BE A
FAIRLY WIDESPREAD LIGHT-MODERATE RAIN EVENT...WITH ONLY THE
SMALLEST CHANCE OF FREEZING RAIN IN FAR NORTHWEST ZONES WED
MORNING. AS THE SYSTEM DEPARTS WED EVENING...CAN`T RULE OUT A VERY
BRIEF PERIOD OF SNOW OR RAIN/SNOW MIX IN THE NORTHEAST. RAISED WED
HIGHS 2-3 DEGREES ON AVERAGE...NOW RANGING FROM UPPER 30S
NORTHWEST TO LOW 50S FAR SOUTHEAST.
IN SUMMARY...MAIN CONCERN OVER NEXT FEW DAYS IS WHETHER OR NOT
FREEZING RAIN WILL AMOUNT TO ANYTHING. DESPITE RECENT WARMING
TRENDS IN MODELS...CURRENTLY HAVE 1-2 HUNDREDTHS OF ICE POTENTIAL
IN MANY AREAS...AND LOCATIONS GENERALLY NORTHWEST OF A GREELEY TO
ELWOOD LINE UP TO AROUND 5 HUNDREDTHS TOTAL. ALTHOUGH THIS WOULD
BE ENOUGH TO CAUSE AT LEAST MINOR ISSUES...CONFIDENCE IN WHETHER
IT WILL OCCUR AT ALL IS STILL LOW ENOUGH TO PRECLUDE ANYTHING
BEYOND AN HWO MENTION. BESIDES...WOULD GENERALLY PREFER TO SEE
TEMPS INTO THE 20S VERSUS LOW 30S/AROUND 30 FOR ICING TO REALLY
TAKE HOLD...AND FOR MOST OF THE NEXT FEW DAYS THIS IS NOT THE CASE
DURING ANTICIPATED TIMES OF PRECIPITATION.
LONG TERM...12Z THURSDAY THROUGH SUNDAY...A RELATIVELY QUIET
WEATHER PATTERN APPEARS TO BE IN STORE FOR THE END OF THE WORK WEEK
AS A SPLIT UPPER LEVEL FLOW PATTERN WILL RESULT IN SHORT WAVE
RIDGING ACROSS THE CENTRAL PLAINS BEHIND WEDNESDAYS DEPARTING
DISTURBANCE. UNDER THIS PATTERN...NORTHWESTERLY FLOW ALOFT WILL
CARRY MULTIPLE UPPER LEVEL DISTURBANCES ACROSS THE NORTHERN PLAINS
AS A CUT OFF LOW MEANDERS ACROSS THE DESERT SOUTHWEST...RESULTING IN
DRY AND SEASONABLE CONDITIONS LOCALLY. QUESTION WILL BE LATE IN THE
EXTENDED WHEN THE AFOREMENTIONED LOW EJECTS INTO THE PLAINS...AS THE
EC AND GFS HAVE DISTINCTLY DIFFERENT SOLUTIONS FOR EARLY NEXT
WEEK...WITH THE GFS TAKING A MUCH MORE NORTHERLY AND WETTER TRACK
LOCALLY WITH THIS LOW AND THE EC KEEPING THE SYSTEM FURTHER SOUTH.
DUE TO THE UNCERTAINTY IN TRACK AND TIMING OF THIS NEXT SYSTEM AS
WELL AS PER COORDINATION WITH SURROUNDING OFFICES...MENTIONED MAINLY
SLIGHT CHANCES FOR PRECIP LATE IN THE UPCOMING WEEKEND AS MOISTURE
ADVECTS NORTHWARD AHEAD OF THE MAIN AREA OF LOW PRESSURE...MOST
LIKELY IN THE FORM OF RAIN OR A RAIN SNOW MIX.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
726 AM CST MON DEC 12 2011
.AVIATION...12Z KGRI TAF. GENERALLY POOR AVIATION CONDITIONS ARE
EXPECTED AT KGRI FOR MUCH OF THE NEXT 24 HOURS. THE WIDESPREAD LOW
LEVEL STRATUS ACROSS THE REGION THIS MORNING IS EXPECTED TO
THICKEN OVER THE NEXT FEW HOURS...WITH LOW MVFR CIGS AND VSBY
LIKELY TO RETURN AND PERSIST AT KGRI THROUGH ABOUT 12/18Z.
CEILINGS AND VSBYS WILL EVENTUALLY IMPROVE TO MORE ELEVATED MVFR
LEVELS BY EARLY AFTERNOON...HOWEVER THIS MINOR IMPROVEMENT IS
EXPECTED TO BE VERY SHORT LIVED...WITH LOW MVFR...OR EVEN
IFR...VISIBILITIES AND CEILINGS EXPECTED TO DEVELOP AFTER THE SUN
SETS. IN ADDITION...AN APPROACHING SYSTEM WILL BRING THE CHANCE
FOR SOME LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN LATE IN THE
TAF PERIOD...BUT KEPT AS -DZ FOR CURRENT TAF ISSUANCE AS ONSET IS
VERY NEAR THE END OF CURRENT VALID PERIOD. LIGHT SOUTHERLY WINDS
NEAR 10 KTS THIS MORNING WILL SHIFT MORE WESTERLY THROUGH THE
PERIOD...EVENTUALLY TRANSITIONING FULL CIRCLE OVERNIGHT...BECOMING
NORTHEASTERLY OVERNIGHT TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 556 AM CST MON DEC 12 2011/
SHORT TERM...THROUGH WEDNESDAY NIGHT. PLENTY OF ISSUES TRYING TO
NAIL DOWN PRECIP TYPES/AMOUNTS ETC. DURING THE NEXT FEW DAYS HAS
LED TO A CHALLENGING NIGHT ON THE FORECAST DESK. MAIN CONCERNS
DURING THE NEXT FEW DAYS INVOLVE WHETHER THE CWA WILL SEE ANY
APPRECIABLE RISK OF GENERALLY LIGHT ICING...ALTHOUGH GENERAL
WARMING TREND OF SURFACE TEMPERATURES DURING LAST SEVERAL MODEL
RUNS SEEMS TO BE CONFINING THE MAIN RISK ZONE TO A SMALLER AND
SMALLER AREA OF THE NORTHWEST CWA.
STARTING OFF EARLY THIS MORNING...BEEN AN INTERESTING NIGHT FROM A
TEMP PERSPECTIVE...AS WIDESPREAD STRATUS AND SOUTHERLY BREEZES
HAVE KEPT READINGS SEVERAL DEGREES ABOVE FREEZING ACROSS THE VAST
MAJORITY OF THE CWA...RESULTING IN A SOMEWHAT RARE MODEST
OVERNIGHT SNOW MELT FOR THIS TIME OF YEAR. MAIN CONCERNS
OVERNIGHT...AND THROUGH THE NEXT FEW/SEVERAL HOURS ARE ACROSS THE
FAR WESTERN PORTIONS OF THE CWA...WHERE WEB CAMS AND AUTOMATED OBS
HAVE SUGGESTED THAT THERE IS A NARROW CORRIDOR OF LOCALLY DENSE
FOG LIKELY LURKING NEAR/WITHIN WESTERN PORTIONS OF DAWSON...GOSPER
AND FURNAS COUNTIES. THIS FOG IS GENERALLY TIED TO THE EDGE OF THE
EXPANSIVE LOW CLOUD DECK COVERING MUCH OF THE REGION...ALONG WHICH
THERE IS QUITE A TEMP GRADIENT INCLUDING A STRIKING 26 DEGREE
DIFFERENCE BETWEEN HOLDREGE AND MCCOOK AT 11Z. WITH ANY DENSE FOG
SEEMINGLY AFFECTING SUCH A SMALL PORTION OF THE AREA...HAVE OPTED
AGAINST AN ADVISORY...BUT HAVE IT MENTIONED IN THE GRIDS AND ALSO
IN THE HWO. AS FOR ANY LIGHT FREEZING DRIZZLE CONCERNS FROM 12-24
HOURS AGO...THESE HAVE APPARENTLY BEEN AVOIDED FOR NOW GIVEN THE
SEASONABLY MILD OVERNIGHT TEMPS...AND EVEN PLAIN LIGHT DRIZZLE HAS
APPARENTLY BEEN QUITE SCANT OVERNIGHT ACROSS THE AREA.
A QUICK LOOK AT 11Z OBJECTIVE SURFACE ANALYSIS PLACES A WEAK
TROUGH AXIS NEAR THE EDGE OF THE STRATUS/NEAR THE WESTERN EDGE OF
THE CWA...WITH STEADY SOUTH BREEZES 5-15 MPH AFFECTING NEARLY ALL
OF THE CWA TO THE EAST OF THIS AXIS. ALOFT...WATER VAPOR IMAGERY
AND SHORT TERM MODEL DATA CONFIRM THE PRESENCE OF A FAIRLY WEAK
MID LEVEL SHORTWAVE STARTING TO DEPART EASTERN NEB TO THE EAST-
NORTHEAST...WITH LOW STRATUS CEILINGS ACTUALLY RISING QUITE A BIT
IN MUCH OF THE CWA IN ITS WAKE. UPSTREAM...THE MAIN LARGE-SCALE
TROUGH OF CONCERN IS STILL CENTERED NEAR THE PACIFIC COAST.
FOR TODAY...THE MAIN CONCERN THIS MORNING IS WHETHER ANY DENSE
FOG ALONG THE STRATUS EDGE CAN WORK A BIT FARTHER EASTWARD INTO
THE AREA. FOR NOW HAVE DENSE FOG MENTION CONFINED SOLELY TO PARTS
OF DAWSON...GOSPER...FURNAS. AS FOR SKY COVER...LATEST SUGGESTIONS
FROM HRRR MODEL IS THAT STRATUS SHOULD HOLD FIRM ACROSS MOST OF
THE CWA THROUGH THE DAY...ALTHOUGH ROUGHLY THE WESTERN 1/4 OF THE
AREA COULD SEE SOME PARTIAL CLEARING ALONG/WEST OF THE WEAK LOW
LEVEL TROUGH AXIS. DEFINITELY SOMETHING TO WATCH. TEMP
WISE...GIVEN THE WARM START RAISED HIGHS ROUGHLY 3-4 DEGREES OVER
PREVIOUS FORECAST MOST AREAS...AND POSSIBLY NOT ENOUGH. WILL AIM
FOR A GRADIENT FROM MID 30S NORTHWEST TO LOW 40S SOUTHEAST...AND
MAYBE EVEN UPPER 40S IN THE MITCHELL COUNTY KS AREA. LIMITED LIFT
SHOULD KEEP ANY POTENTIAL DRIZZLE AT BAY TODAY.
TONIGHT...MAIN CHANGE WAS TO RAISE LOW TEMPS A NOTABLE 4-8 DEGREES
OVER PREVIOUS FORECAST MOST AREAS...ALTHOUGH THIS IS VERY
DEPENDENT ON WIDESPREAD CLOUD COVER HOLDING FIRM. ASSUMING THIS
OCCURS...AM NOW TALKING A GRADIENT FROM LOW-MID 20S NORTHWEST TO
LOW-MID 30S SOUTHEAST. WITH LIGHT WINDS...CANNOT RULE OUT PATCHY
TO AREAS OF FOG OVERNIGHT...BUT NOTHING THAT CAN REALLY BE PINNED
DOWN FOR POSSIBLE DENSE DEVELOPMENT. KEPT THEME FROM PREVIOUS
FORECAST INTACT...WITH SLIGHT CHANCE OF DRIZZLE IN THE SOUTH
BEFORE MIDNIGHT...AND THEN BETTER CHANCES FOR LIGHT MEASURABLE
PRECIP AFTER MIDNIGHT MAINLY ACROSS THE SOUTHERN HALF OF THE CWA
AS FIRST LEAD SHORTWAVE MOVES INTO THE REGION. COULD SEE LIGHT
ICING MAINLY ACROSS NEB ZONES...BUT NOT ANTICIPATING MAJOR ISSUES
AND DAY SHIFT SHOULD BE ABLE TO BETTER PIN DOWN THE SURFACE TEMP
TREND.
TUESDAY...RAISED POPS 10-20 PERCENT OVER PREVIOUS FORECAST MAINLY
FOR THE AFTERNOON...WITH 60-80 POPS NOW OVER MUCH OF THE
CENTRAL/SOUTHEAST CWA. ALSO RAISED HIGHS 2-4 DEGREES MOST
AREAS...WITH ANY RISK FOR FREEZING RAIN DURING THE DAY LARGELY
CONFINED TO LOCATIONS NORTHWEST OF A GREELEY-ELWOOD LINE...AND
EVEN THIS AREA MAY BE OVERDONE IF THE ECMWF/GFS HAVE A DECENT
HANDLE ON SURFACE TEMPS. HAVE HIGHS RANGING FROM THE MID 30S
NORTHWEST TO LOW-MID 40S IN KS ZONES AND AROUND HEBRON.
TUESDAY NIGHT...FORCING FROM INCOMING MID LEVEL WAVE AND UPPER
LEVEL JET INCREASE...AND HAVE AT LEAST 50 POPS CWA-WIDE...AND
LIKELIES MAINLY ACROSS THE EASTERN 1/3. COULD EASILY SEE SLIGHTLY
RISING/AT LEAST STEADY TEMPS THROUGH THE NIGHT...WITH ANY MENTION
OF FREEZING RAIN NOW CONFINED MAINLY TO VALLEY...SHERMAN...DAWSON
COUNTIES. WITH BOTH THE NAM/GFS PULLING AT LEAST 100-300 J/KG OF
MUCAPE INTO THE CWA...AND THE SREF PROBABILITIES INCREASING FOR
GENERAL THUNDER...EVEN INTRODUCED AN ISOLATED THUNDER MENTION TO
ROUGHLY THE SOUTHEAST 1/2 OF THE CWA OVERNIGHT...WHICH MAY OR MAY
NOT EXTEND INTO WED AS WELL BUT DON/T HAVE IT IN THERE YET.
WED INTO WED NIGHT...THE MAIN MID LEVEL WAVE MOVES DIRECTLY
THROUGH THE REGION...WITH ALL PRECIP LIKELY OVER BY MIDNIGHT. HAVE
LIKELY POPS ALREADY IN PLACE ACROSS ROUGHLY THE EASTERN 1/2 OF THE
CWA ALREADY...WHICH MAY NEED EXTENDED WESTWARD IN LATER UPDATES.
UNLESS MODELS SUDDENLY START TRENDING COLDER...THIS SHOULD BE A
FAIRLY WIDESPREAD LIGHT-MODERATE RAIN EVENT...WITH ONLY THE
SMALLEST CHANCE OF FREEZING RAIN IN FAR NORTHWEST ZONES WED
MORNING. AS THE SYSTEM DEPARTS WED EVENING...CAN`T RULE OUT A VERY
BRIEF PERIOD OF SNOW OR RAIN/SNOW MIX IN THE NORTHEAST. RAISED WED
HIGHS 2-3 DEGREES ON AVERAGE...NOW RANGING FROM UPPER 30S
NORTHWEST TO LOW 50S FAR SOUTHEAST.
IN SUMMARY...MAIN CONCERN OVER NEXT FEW DAYS IS WHETHER OR NOT
FREEZING RAIN WILL AMOUNT TO ANYTHING. DESPITE RECENT WARMING
TRENDS IN MODELS...CURRENTLY HAVE 1-2 HUNDREDTHS OF ICE POTENTIAL
IN MANY AREAS...AND LOCATIONS GENERALLY NORTHWEST OF A GREELEY TO
ELWOOD LINE UP TO AROUND 5 HUNDREDTHS TOTAL. ALTHOUGH THIS WOULD
BE ENOUGH TO CAUSE AT LEAST MINOR ISSUES...CONFIDENCE IN WHETHER
IT WILL OCCUR AT ALL IS STILL LOW ENOUGH TO PRECLUDE ANYTHING
BEYOND AN HWO MENTION. BESIDES...WOULD GENERALLY PREFER TO SEE
TEMPS INTO THE 20S VERSUS LOW 30S/AROUND 30 FOR ICING TO REALLY
TAKE HOLD...AND FOR MOST OF THE NEXT FEW DAYS THIS IS NOT THE CASE
DURING ANTICIPATED TIMES OF PRECIPITATION.
LONG TERM...12Z THURSDAY THROUGH SUNDAY...A RELATIVELY QUIET
WEATHER PATTERN APPEARS TO BE IN STORE FOR THE END OF THE WORK WEEK
AS A SPLIT UPPER LEVEL FLOW PATTERN WILL RESULT IN SHORT WAVE
RIDGING ACROSS THE CENTRAL PLAINS BEHIND WEDNESDAYS DEPARTING
DISTURBANCE. UNDER THIS PATTERN...NORTHWESTERLY FLOW ALOFT WILL
CARRY MULTIPLE UPPER LEVEL DISTURBANCES ACROSS THE NORTHERN PLAINS
AS A CUT OFF LOW MEANDERS ACROSS THE DESERT SOUTHWEST...RESULTING IN
DRY AND SEASONABLE CONDITIONS LOCALLY. QUESTION WILL BE LATE IN THE
EXTENDED WHEN THE AFOREMENTIONED LOW EJECTS INTO THE PLAINS...AS THE
EC AND GFS HAVE DISTINCTLY DIFFERENT SOLUTIONS FOR EARLY NEXT
WEEK...WITH THE GFS TAKING A MUCH MORE NORTHERLY AND WETTER TRACK
LOCALLY WITH THIS LOW AND THE EC KEEPING THE SYSTEM FURTHER SOUTH.
DUE TO THE UNCERTAINTY IN TRACK AND TIMING OF THIS NEXT SYSTEM AS
WELL AS PER COORDINATION WITH SURROUNDING OFFICES...MENTIONED MAINLY
SLIGHT CHANCES FOR PRECIP LATE IN THE UPCOMING WEEKEND AS MOISTURE
ADVECTS NORTHWARD AHEAD OF THE MAIN AREA OF LOW PRESSURE...MOST
LIKELY IN THE FORM OF RAIN OR A RAIN SNOW MIX.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
556 AM CST MON DEC 12 2011
.SHORT TERM...THROUGH WEDNESDAY NIGHT. PLENTY OF ISSUES TRYING TO
NAIL DOWN PRECIP TYPES/AMOUNTS ETC. DURING THE NEXT FEW DAYS HAS
LED TO A CHALLENGING NIGHT ON THE FORECAST DESK. MAIN CONCERNS
DURING THE NEXT FEW DAYS INVOLVE WHETHER THE CWA WILL SEE ANY
APPRECIABLE RISK OF GENERALLY LIGHT ICING...ALTHOUGH GENERAL
WARMING TREND OF SURFACE TEMPERATURES DURING LAST SEVERAL MODEL
RUNS SEEMS TO BE CONFINING THE MAIN RISK ZONE TO A SMALLER AND
SMALLER AREA OF THE NORTHWEST CWA.
STARTING OFF EARLY THIS MORNING...BEEN AN INTERESTING NIGHT FROM A
TEMP PERSPECTIVE...AS WIDESPREAD STRATUS AND SOUTHERLY BREEZES
HAVE KEPT READINGS SEVERAL DEGREES ABOVE FREEZING ACROSS THE VAST
MAJORITY OF THE CWA...RESULTING IN A SOMEWHAT RARE MODEST
OVERNIGHT SNOW MELT FOR THIS TIME OF YEAR. MAIN CONCERNS
OVERNIGHT...AND THROUGH THE NEXT FEW/SEVERAL HOURS ARE ACROSS THE
FAR WESTERN PORTIONS OF THE CWA...WHERE WEB CAMS AND AUTOMATED OBS
HAVE SUGGESTED THAT THERE IS A NARROW CORRIDOR OF LOCALLY DENSE
FOG LIKELY LURKING NEAR/WITHIN WESTERN PORTIONS OF DAWSON...GOSPER
AND FURNAS COUNTIES. THIS FOG IS GENERALLY TIED TO THE EDGE OF THE
EXPANSIVE LOW CLOUD DECK COVERING MUCH OF THE REGION...ALONG WHICH
THERE IS QUITE A TEMP GRADIENT INCLUDING A STRIKING 26 DEGREE
DIFFERENCE BETWEEN HOLDREGE AND MCCOOK AT 11Z. WITH ANY DENSE FOG
SEEMINGLY AFFECTING SUCH A SMALL PORTION OF THE AREA...HAVE OPTED
AGAINST AN ADVISORY...BUT HAVE IT MENTIONED IN THE GRIDS AND ALSO
IN THE HWO. AS FOR ANY LIGHT FREEZING DRIZZLE CONCERNS FROM 12-24
HOURS AGO...THESE HAVE APPARENTLY BEEN AVOIDED FOR NOW GIVEN THE
SEASONABLY MILD OVERNIGHT TEMPS...AND EVEN PLAIN LIGHT DRIZZLE HAS
APPARENTLY BEEN QUITE SCANT OVERNIGHT ACROSS THE AREA.
A QUICK LOOK AT 11Z OBJECTIVE SURFACE ANALYSIS PLACES A WEAK
TROUGH AXIS NEAR THE EDGE OF THE STRATUS/NEAR THE WESTERN EDGE OF
THE CWA...WITH STEADY SOUTH BREEZES 5-15 MPH AFFECTING NEARLY ALL
OF THE CWA TO THE EAST OF THIS AXIS. ALOFT...WATER VAPOR IMAGERY
AND SHORT TERM MODEL DATA CONFIRM THE PRESENCE OF A FAIRLY WEAK
MID LEVEL SHORTWAVE STARTING TO DEPART EASTERN NEB TO THE EAST-
NORTHEAST...WITH LOW STRATUS CEILINGS ACTUALLY RISING QUITE A BIT
IN MUCH OF THE CWA IN ITS WAKE. UPSTREAM...THE MAIN LARGE-SCALE
TROUGH OF CONCERN IS STILL CENTERED NEAR THE PACIFIC COAST.
FOR TODAY...THE MAIN CONCERN THIS MORNING IS WHETHER ANY DENSE
FOG ALONG THE STRATUS EDGE CAN WORK A BIT FARTHER EASTWARD INTO
THE AREA. FOR NOW HAVE DENSE FOG MENTION CONFINED SOLELY TO PARTS
OF DAWSON...GOSPER...FURNAS. AS FOR SKY COVER...LATEST SUGGESTIONS
FROM HRRR MODEL IS THAT STRATUS SHOULD HOLD FIRM ACROSS MOST OF
THE CWA THROUGH THE DAY...ALTHOUGH ROUGHLY THE WESTERN 1/4 OF THE
AREA COULD SEE SOME PARTIAL CLEARING ALONG/WEST OF THE WEAK LOW
LEVEL TROUGH AXIS. DEFINITELY SOMETHING TO WATCH. TEMP
WISE...GIVEN THE WARM START RAISED HIGHS ROUGHLY 3-4 DEGREES OVER
PREVIOUS FORECAST MOST AREAS...AND POSSIBLY NOT ENOUGH. WILL AIM
FOR A GRADIENT FROM MID 30S NORTHWEST TO LOW 40S SOUTHEAST...AND
MAYBE EVEN UPPER 40S IN THE MITCHELL COUNTY KS AREA. LIMITED LIFT
SHOULD KEEP ANY POTENTIAL DRIZZLE AT BAY TODAY.
TONIGHT...MAIN CHANGE WAS TO RAISE LOW TEMPS A NOTABLE 4-8 DEGREES
OVER PREVIOUS FORECAST MOST AREAS...ALTHOUGH THIS IS VERY
DEPENDENT ON WIDESPREAD CLOUD COVER HOLDING FIRM. ASSUMING THIS
OCCURS...AM NOW TALKING A GRADIENT FROM LOW-MID 20S NORTHWEST TO
LOW-MID 30S SOUTHEAST. WITH LIGHT WINDS...CANNOT RULE OUT PATCHY
TO AREAS OF FOG OVERNIGHT...BUT NOTHING THAT CAN REALLY BE PINNED
DOWN FOR POSSIBLE DENSE DEVELOPMENT. KEPT THEME FROM PREVIOUS
FORECAST INTACT...WITH SLIGHT CHANCE OF DRIZZLE IN THE SOUTH
BEFORE MIDNIGHT...AND THEN BETTER CHANCES FOR LIGHT MEASURABLE
PRECIP AFTER MIDNIGHT MAINLY ACROSS THE SOUTHERN HALF OF THE CWA
AS FIRST LEAD SHORTWAVE MOVES INTO THE REGION. COULD SEE LIGHT
ICING MAINLY ACROSS NEB ZONES...BUT NOT ANTICIPATING MAJOR ISSUES
AND DAY SHIFT SHOULD BE ABLE TO BETTER PIN DOWN THE SURFACE TEMP
TREND.
TUESDAY...RAISED POPS 10-20 PERCENT OVER PREVIOUS FORECAST MAINLY
FOR THE AFTERNOON...WITH 60-80 POPS NOW OVER MUCH OF THE
CENTRAL/SOUTHEAST CWA. ALSO RAISED HIGHS 2-4 DEGREES MOST
AREAS...WITH ANY RISK FOR FREEZING RAIN DURING THE DAY LARGELY
CONFINED TO LOCATIONS NORTHWEST OF A GREELEY-ELWOOD LINE...AND
EVEN THIS AREA MAY BE OVERDONE IF THE ECMWF/GFS HAVE A DECENT
HANDLE ON SURFACE TEMPS. HAVE HIGHS RANGING FROM THE MID 30S
NORTHWEST TO LOW-MID 40S IN KS ZONES AND AROUND HEBRON.
TUESDAY NIGHT...FORCING FROM INCOMING MID LEVEL WAVE AND UPPER
LEVEL JET INCREASE...AND HAVE AT LEAST 50 POPS CWA-WIDE...AND
LIKELIES MAINLY ACROSS THE EASTERN 1/3. COULD EASILY SEE SLIGHTLY
RISING/AT LEAST STEADY TEMPS THROUGH THE NIGHT...WITH ANY MENTION
OF FREEZING RAIN NOW CONFINED MAINLY TO VALLEY...SHERMAN...DAWSON
COUNTIES. WITH BOTH THE NAM/GFS PULLING AT LEAST 100-300 J/KG OF
MUCAPE INTO THE CWA...AND THE SREF PROBABILITIES INCREASING FOR
GENERAL THUNDER...EVEN INTRODUCED AN ISOLATED THUNDER MENTION TO
ROUGHLY THE SOUTHEAST 1/2 OF THE CWA OVERNIGHT...WHICH MAY OR MAY
NOT EXTEND INTO WED AS WELL BUT DON/T HAVE IT IN THERE YET.
WED INTO WED NIGHT...THE MAIN MID LEVEL WAVE MOVES DIRECTLY
THROUGH THE REGION...WITH ALL PRECIP LIKELY OVER BY MIDNIGHT. HAVE
LIKELY POPS ALREADY IN PLACE ACROSS ROUGHLY THE EASTERN 1/2 OF THE
CWA ALREADY...WHICH MAY NEED EXTENDED WESTWARD IN LATER UPDATES.
UNLESS MODELS SUDDENLY START TRENDING COLDER...THIS SHOULD BE A
FAIRLY WIDESPREAD LIGHT-MODERATE RAIN EVENT...WITH ONLY THE
SMALLEST CHANCE OF FREEZING RAIN IN FAR NORTHWEST ZONES WED
MORNING. AS THE SYSTEM DEPARTS WED EVENING...CAN`T RULE OUT A VERY
BRIEF PERIOD OF SNOW OR RAIN/SNOW MIX IN THE NORTHEAST. RAISED WED
HIGHS 2-3 DEGREES ON AVERAGE...NOW RANGING FROM UPPER 30S
NORTHWEST TO LOW 50S FAR SOUTHEAST.
IN SUMMARY...MAIN CONCERN OVER NEXT FEW DAYS IS WHETHER OR NOT
FREEZING RAIN WILL AMOUNT TO ANYTHING. DESPITE RECENT WARMING
TRENDS IN MODELS...CURRENTLY HAVE 1-2 HUNDREDTHS OF ICE POTENTIAL
IN MANY AREAS...AND LOCATIONS GENERALLY NORTHWEST OF A GREELEY TO
ELWOOD LINE UP TO AROUND 5 HUNDREDTHS TOTAL. ALTHOUGH THIS WOULD
BE ENOUGH TO CAUSE AT LEAST MINOR ISSUES...CONFIDENCE IN WHETHER
IT WILL OCCUR AT ALL IS STILL LOW ENOUGH TO PRECLUDE ANYTHING
BEYOND AN HWO MENTION. BESIDES...WOULD GENERALLY PREFER TO SEE
TEMPS INTO THE 20S VERSUS LOW 30S/AROUND 30 FOR ICING TO REALLY
TAKE HOLD...AND FOR MOST OF THE NEXT FEW DAYS THIS IS NOT THE CASE
DURING ANTICIPATED TIMES OF PRECIPITATION.
.LONG TERM...12Z THURSDAY THROUGH SUNDAY...A RELATIVELY QUIET
WEATHER PATTERN APPEARS TO BE IN STORE FOR THE END OF THE WORK WEEK
AS A SPLIT UPPER LEVEL FLOW PATTERN WILL RESULT IN SHORT WAVE
RIDGING ACROSS THE CENTRAL PLAINS BEHIND WEDNESDAYS DEPARTING
DISTURBANCE. UNDER THIS PATTERN...NORTHWESTERLY FLOW ALOFT WILL
CARRY MULTIPLE UPPER LEVEL DISTURBANCES ACROSS THE NORTHERN PLAINS
AS A CUT OFF LOW MEANDERS ACROSS THE DESERT SOUTHWEST...RESULTING IN
DRY AND SEASONABLE CONDITIONS LOCALLY. QUESTION WILL BE LATE IN THE
EXTENDED WHEN THE AFOREMENTIONED LOW EJECTS INTO THE PLAINS...AS THE
EC AND GFS HAVE DISTINCTLY DIFFERENT SOLUTIONS FOR EARLY NEXT
WEEK...WITH THE GFS TAKING A MUCH MORE NORTHERLY AND WETTER TRACK
LOCALLY WITH THIS LOW AND THE EC KEEPING THE SYSTEM FURTHER SOUTH.
DUE TO THE UNCERTAINTY IN TRACK AND TIMING OF THIS NEXT SYSTEM AS
WELL AS PER COORDINATION WITH SURROUNDING OFFICES...MENTIONED MAINLY
SLIGHT CHANCES FOR PRECIP LATE IN THE UPCOMING WEEKEND AS MOISTURE
ADVECTS NORTHWARD AHEAD OF THE MAIN AREA OF LOW PRESSURE...MOST
LIKELY IN THE FORM OF RAIN OR A RAIN SNOW MIX.
&&
.PREV DISCUSSION... /ISSUED 945 PM CST SUN DEC 11 2011/
AVIATION...12Z KGRI TAF. GENERALLY POOR AVIATION CONDITIONS ARE
EXPECTED AT KGRI FOR MUCH OF THE NEXT 24 HOURS. THE WIDESPREAD LOW
LEVEL STRATUS ACROSS THE REGION THIS MORNING IS EXPECTED TO
THICKEN OVER THE NEXT FEW HOURS...WITH LOW MVFR CIGS AND VSBY
LIKELY TO RETURN AND PERSIST AT KGRI THROUGH ABOUT 12/18Z.
CEILINGS AND VSBYS WILL EVENTUALLY IMPROVE TO MORE ELEVATED MVFR
LEVELS BY EARLY AFTERNOON...HOWEVER THIS MINOR IMPROVEMENT IS
EXPECTED TO BE VERY SHORT LIVED...WITH LOW MVFR...OR EVEN
IFR...VISIBILITIES AND CEILINGS EXPECTED TO DEVELOP AFTER THE SUN
SETS. IN ADDITION...AN APPROACHING SYSTEM WILL BRING THE CHANCE
FOR SOME LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN LATE IN THE
TAF PERIOD...BUT KEPT AS -DZ FOR CURRENT TAF ISSUANCE AS ONSET IS
VERY NEAR THE END OF CURRENT VALID PERIOD. LIGHT SOUTHERLY WINDS
NEAR 10 KTS THIS MORNING WILL SHIFT MORE WESTERLY THROUGH THE
PERIOD...EVENTUALLY TRANSITIONING FULL CIRCLE OVERNIGHT...BECOMING
NORTHEASTERLY OVERNIGHT TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1015 AM CST MON DEC 12 2011
.DISCUSSION...CLOUDS AND RESULTANT TEMPERATURES CONTINUE TO BE THE
MAIN CHALLENGE TODAY. 925MB WINDS ARE NORTHEAST WHILE SFC WINDS
ARE DUE NORTH...AND THESE WINDS SHOULD REMAIN CONSISTENT THROUGH
THE DAY. THUS...CURRENT CLOUD LOCATIONS EXPECTED TO CHANGE LITTLE
(CLEARING AREA SOMEWHERE IN THE MIDDLE OF THE FA). NOT SURE IF THE
CLEAR AREA WILL FILL IN...BUT MODEL CONVECTIVE TEMPS INTO THE 70S
SUGGEST IT WILL NOT. BASED ON EXPECTED CLOUD COVER...ADJUSTED
TEMPS FOR LITTLE RISE UNDER CLOUDS AND 5-7F RISE IN CLEAR AREA.
&&
.AVIATION...THERE STILL REMAINS A HIGH DEGREE OF UNCERTAINTY
CONCERNING CEILING FORECAST TODAY. KDVL...KBJI...KFAR ARE
IFR/MVFR WHILE KGFK AND KTVF ARE VFR. IFR/MVFR CEILINGS LIKELY TO
REMAIN IN ABOUT THE SAME LOCATION THROUGH THE AFTERNOON HOURS.
DUE TO DRY NORTHEAST LOW-LEVEL FLOW...DIFFICULT TO KNOW THE
EXTENT TO WHICH CLOUDS MAY IMPACT TAF SITES. KGFK AND KTVF SHOULD
STAY VFR THROUGH AT LEAST 18 UTC...WITH LOW CLOUDS POSSIBLY
IMPACTING THESE AIRFIELDS THIS AFTERNOON. WILL UPDATE TAFS AS
GREATER CERTAINTY IS REALIZED.
&&
.PREV DISCUSSION... /ISSUED 402 AM CST MON DEC 12 2011/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
PRIMARY FORECAST CHALLENGE WILL BE CLOUD COVER AND CORRESPONDING
TEMPERATURES. GFS/NAM/ECMWF/GEM MASS/THERMAL FIELDS ARE IN GOOD
AGREEMENT...BUT ONLY THE RUC AND HRRR BEST RESEMBLE CURRENT CLOUD
TRENDS. WILL FOLLOW HIGH RESOLUTION MODELS FOR THE NEAR TERM...
TRANSITIONING TO A MODEL BLEND THEREAFTER.
09 UTC SURFACE ANALYSIS SHOWS A WEAK TROUGH EXTENDING FROM SOUTH
CENTRAL SD INTO THE MN ARROWHEAD WITH LOW STRATUS ALONG AND
SOUTHEAST OF THE TROUGH AXIS. A SECOND AREA OF LOW CLOUDS IS
TRAPPED BENEATH CANADIAN HIGH PRESSURE AND EXTENDS ALONG AND
NORTHWEST OF A LINE FROM HALLOCK TO DEVILS LAKE TO BISMARCK.
BETWEEN THESE CLOUDS SKIES ARE CLEAR...BUT THE TWO CLOUD DECKS
ARE CRAWLING TOWARD EACH OTHER. RUC/HRRR SUGGEST DRY LOW-LEVEL
NORTHEAST FLOW WILL KEEP SOUTHEAST ND INTO NORTH CENTRAL MN CLOUD
FREE THROUGH AT LEAST EARLY MORNING...BUT MAY BEGIN TO FILL IN
THEREAFTER. AS A RESULT...AREAS NOT IN THE NORTHWEST OR SOUTHEAST
FORECAST AREA WILL START THE DAY SUNNY WITH A GRADUAL INCREASE IN
CLOUDS...POSSIBLY BECOMING MOSTLY CLOUDY BY LATE THIS AFTERNOON.
WILL KEEP FORECAST DRY TODAY...BUT SOME LIGHT DRIZZLE IS POSSIBLE
GIVEN VERY DRY AIR ATOP NEAR SURFACE SATURATED LAYER. AS CLOUD COVER
EXPANDS...DO NOT EXPECT MUCH MOVEMENT IN TEMPERATURES WITH A
GENERAL GRADIENT FROM THE UPPER TEENS ACROSS PORTIONS OF THE
DEVILS LAKE BASIN TO THE UPPER 20S TO NEAR 30 DEGREES ACROSS WEST
CENTRAL MN. LIGHT NORTHEAST WIND WILL BE THE RULE THROUGH THE DAY.
TUESDAY WILL BE DRY AND SLIGHTLY WARMER AS SURFACE HIGH PRESSURE
AXIS DRIFTS ACROSS THE FORECAST AREA AND LIGHT RETURN FLOW DEVELOPS.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S.
DID NOT CHANGE POPS MUCH WEDNESDAY AND WEDNESDAY NIGHT...KEEPING
CHANCES FOR SNOW ALONG AND EAST OF A LINE FROM LISBON TO FARGO TO
BAUDETTE. MODELS ARE NOW IN GOOD AGREEMENT SHOWING A NORTHERN STREAM
SHORT-WAVE KICK MORE POTENT ENERGY FROM SOUTHWEST CONUS CUT-OFF
LOW FARTHER SOUTH AND EAST ACROSS IA AND WI. ACCUMULATIONS...IF
ANY...SHOULD BE MINIMAL. TEMPERATURES WEDNESDAY WILL RISE INTO THE
UPPER 20S TO LOWER 30S BEFORE COOLING OFF THE LATTER HALF OF THE
WEEK.
LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
THE MAIN CHALLENGE WILL CONTINUE TO BE TEMPS WITH NO STORMS IN
SIGHT. A COLD FRONT WILL USHER IN MUCH COLDER AIR ON THURSDAY ALONG
WITH BRISK/BREEZY CONDITIONS. TEMPS WILL MODERATE ABOVE NORMAL
BY NEXT WEEKEND WITH UPPER RIDGE BUILDING AND 850MB TEMPS CLIMBING
OVER 0C ONCE AGAIN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
402 AM CST MON DEC 12 2011
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
PRIMARY FORECAST CHALLENGE WILL BE CLOUD COVER AND CORRESPONDING
TEMPERATURES. GFS/NAM/ECMWF/GEM MASS/THERMAL FIELDS ARE IN GOOD
AGREEMENT...BUT ONLY THE RUC AND HRRR BEST RESEMBLE CURRENT CLOUD
TRENDS. WILL FOLLOW HIGH RESOLUTION MODELS FOR THE NEAR TERM...
TRANSITIONING TO A MODEL BLEND THEREAFTER.
09 UTC SURFACE ANALYSIS SHOWS A WEAK TROUGH EXTENDING FROM SOUTH
CENTRAL SD INTO THE MN ARROWHEAD WITH LOW STRATUS ALONG AND
SOUTHEAST OF THE TROUGH AXIS. A SECOND AREA OF LOW CLOUDS IS
TRAPPED BENEATH CANADIAN HIGH PRESSURE AND EXTENDS ALONG AND
NORTHWEST OF A LINE FROM HALLOCK TO DEVILS LAKE TO BISMARCK.
BETWEEN THESE CLOUDS SKIES ARE CLEAR...BUT THE TWO CLOUD DECKS
ARE CRAWLING TOWARD EACH OTHER. RUC/HRRR SUGGEST DRY LOW-LEVEL
NORTHEAST FLOW WILL KEEP SOUTHEAST ND INTO NORTH CENTRAL MN CLOUD
FREE THROUGH AT LEAST EARLY MORNING...BUT MAY BEGIN TO FILL IN
THEREAFTER. AS A RESULT...AREAS NOT IN THE NORTHWEST OR SOUTHEAST
FORECAST AREA WILL START THE DAY SUNNY WITH A GRADUAL INCREASE IN
CLOUDS...POSSIBLY BECOMING MOSTLY CLOUDY BY LATE THIS AFTERNOON.
WILL KEEP FORECAST DRY TODAY...BUT SOME LIGHT DRIZZLE IS POSSIBLE
GIVEN VERY DRY AIR ATOP NEAR SURFACE SATURATED LAYER. AS CLOUD COVER
EXPANDS...DO NOT EXPECT MUCH MOVEMENT IN TEMPERATURES WITH A
GENERAL GRADIENT FROM THE UPPER TEENS ACROSS PORTIONS OF THE
DEVILS LAKE BASIN TO THE UPPER 20S TO NEAR 30 DEGREES ACROSS WEST
CENTRAL MN. LIGHT NORTHEAST WIND WILL BE THE RULE THROUGH THE DAY.
TUESDAY WILL BE DRY AND SLIGHTLY WARMER AS SURFACE HIGH PRESSURE
AXIS DRIFTS ACROSS THE FORECAST AREA AND LIGHT RETURN FLOW DEVELOPS.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S.
DID NOT CHANGE POPS MUCH WEDNESDAY AND WEDNESDAY NIGHT...KEEPING
CHANCES FOR SNOW ALONG AND EAST OF A LINE FROM LISBON TO FARGO TO
BAUDETTE. MODELS ARE NOW IN GOOD AGREEMENT SHOWING A NORTHERN STREAM
SHORT-WAVE KICK MORE POTENT ENERGY FROM SOUTHWEST CONUS CUT-OFF
LOW FARTHER SOUTH AND EAST ACROSS IA AND WI. ACCUMULATIONS...IF
ANY...SHOULD BE MINIMAL. TEMPERATURES WEDNESDAY WILL RISE INTO THE
UPPER 20S TO LOWER 30S BEFORE COOLING OFF THE LATTER HALF OF THE
WEEK.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
THE MAIN CHALLENGE WILL CONTINUE TO BE TEMPS WITH NO STORMS IN
SIGHT. A COLD FRONT WILL USHER IN MUCH COLDER AIR ON THURSDAY ALONG
WITH BRISK/BREEZY CONDITIONS. TEMPS WILL MODERATE ABOVE NORMAL
BY NEXT WEEKEND WITH UPPER RIDGE BUILDING AND 850MB TEMPS CLIMBING
OVER 0C ONCE AGAIN.
&&
.AVIATION...
HIGH DEGREE OF UNCERTAINTY CONCERNING CEILING FORECAST TODAY AS
THE REGION IS SANDWICHED BY IFR/LOW MVFR CLOUDS TO THE NORTHWEST
AND SOUTHEAST. KDVL AND KBJI ARE CLOUDY WITH CLEARING JUST TO
THEIR SOUTHEAST AND NORTHWEST RESPECTIVELY. IFR/MVFR CEILINGS
LIKELY TO IMPACT THESE TWO AIRFIELDS FOR MUCH OF THE DAY. DUE TO
DRY NORTHEAST LOW-LEVEL FLOW...DIFFICULT TO KNOW THE EXTENT TO
WHICH CLOUDS MAY IMPACT VALLEY TAF SITES. KGFK...KFAR AND KTVF
SHOULD STAY CLOUD-FREE THROUGH AT LEAST 12 UTC...WITH LOW CLOUDS
POSSIBLY IMPACTING AIRFIELDS LATER THIS MORNING OR EARLY AFTERNOON.
WILL UPDATE TAFS AS GREATER CERTAINTY IS REALIZED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/DK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1239 PM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONS WEATHER INTO TUESDAY. THE
HIGH WILL MOVE EAST TUESDAY NIGHT AS A WARM FRONT APPROACHES THE
AREA FROM THE SOUTHWEST. THE WARM FRONT WILL PUSH ACROSS THE
REGION ON WEDNESDAY...FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT
INTO THURSDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND COAST
TO THE THE OHIO AND TENNESSEE VALLEYS THIS MORNING. THE HIGH IS
EXPECTED TO MOVE LITTLE TODAY. AFTER A COLD START...TEMPERATURES
WILL MODERATE UNDER ABUNDANT SUNSHINE. CIRRUS WILL INCREASE IN
COVERAGE BUT IT WILL REMAIN MOSTLY SUNNY. HIGHS WILL RANGE FROM
THE LOWER 40S NORTH TO THE UPPER 40S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE WILL REESTABLISH ITSELF OVER THE OHIO VALLEY
TONIGHT INTO TUESDAY. MEANWHILE...WEAK UPR LVL ENERGY WILL TRACK
ACROSS THE GREAT LAKES. RETURN LOW LEVEL FLOW MAY BRING SOME LOWER
CLOUDS TO OUR SE CWFA THIS EVENING/OVERNIGHT WHILE MID LVL
MOISTURE STREAMS IN FROM THE WEST. CLOUD COVER WILL PREVENT
TEMPERATURES FROM COOLING OFF TOO MUCH AND SHOULD RANGE FROM THE
MID 20S TO THE LOWER 30S. SKIES ON TUESDAY WILL RANGE FROM
PARTLY TO MOSTLY CLOUDY AS MID LVL MOISTURE CONTINUES TO ADVECT
ACROSS THE REGION FROM THE WEST. HIGHS WILL VARY FROM THE MID 40S
NORTH TO NEAR 50 SOUTH.
MODELS ARE IN GOOD AGREEMENT FOR TUESDAY NIGHT INTO WEDNESDAY.
SURFACE HIGH WILL MOVE EAST AS A WARM FRONT DEVELOPS TO OUR
SOUTHWEST. THE WARM FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY.
DEEP MOISTURE WILL INCREASE OVER THE REGION THROUGH THE PERIOD.
THIS MOISTURE WILL COINCIDE WITH A STRONG LOW LEVEL JET AND UPR
LVL DIVERGENCE FROM THE RR QUAD OF AN UPR LVL JET. THIS WILL
RESULT IN SHOWERS WITH THE HIGHEST THREAT POISED FOR THE NRN
ZONES. HAVE RAISED POPS TO CATEGORICAL ACRS NRN AREAS TUESDAY
NIGHT INTO WEDNESDAY. PCPN CHANCES WILL DIMINISH TO LOW CHANCE
SOUTH OF THE OHIO RIVER.
THE WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY NIGHT. THE
WARM FRONT WILL BE FOLLOWED BY A COLD FRONT WHICH WILL PUSH
SOUTHEAST ACROSS THE REGION ON THURSDAY. DEEP MOISTURE COUPLED
WITH DECENT LOW LEVEL FORCING AHEAD OF THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS. HAVE GONE WITH CATEGORICAL POPS. THE
FRONT WILL PUSH SOUTHEAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS
INTO THE WESTERN GREAT LAKES. THIS WILL BRING AN END TO THE PCPN.
TEMPERATURES TUESDAY NIGHT INTO THURSDAY NIGHT WILL EXHIBIT NON
DIURNAL TRENDS AND HAVE RELIED ON A BLEND OF RAW 2 M GFS AND ECMWF
FOR THE MOST PART.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND. A WEAK
SHORT WAVE MAY DROP DOWN ACROSS THE GREAT LAKES ON SATURDAY...BUT
IT LOOKS LIKE BETTER FORCING WITH THIS WILL REMAIN OFF TO OUR
NORTH SO WILL THEREFORE MAINTAIN A DRY FORECAST THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. COOLER AIR WILL FILTER IN
BEHIND THE FRONT LATE IN THE WEEK...LEADING TO A RETURN TO MORE
SEASONABLE TEMPERATURES THROUGH THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
WITH HIGH PRESSURE REMAINING OVER THE REGION...VFR IS EXPECTED TO
PERSIST. BR FORMATION IS NOT LIKELY IN THIS DRY AIRMASS. MODELS
SHOW INCREASING CLOUDS...FIRST IN HIGH LEVELS TODAY...THEN IN
THE MID LEVELS TONIGHT...FOLLOWED BY A LAYER AT AROUND 5000 FT ON
TUESDAY. WINDS WILL STAY LIGHT OUT OF THE SOUTH.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...CONIGLIO/HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
933 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONS WEATHER INTO TUESDAY. THE
HIGH WILL MOVE EAST TUESDAY NIGHT AS A WARM FRONT APPROACHES THE
AREA FROM THE SOUTHWEST. THE WARM FRONT WILL PUSH ACROSS THE
REGION ON WEDNESDAY...FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT
INTO THURSDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND COAST
TO THE THE OHIO AND TENNESSEE VALLEYS THIS MORNING. THE HIGH IS
EXPECTED TO MOVE LITTLE TODAY. AFTER A COLD START...TEMPERATURES
WILL MODERATE UNDER ABUNDANT SUNSHINE. CIRRUS WILL INCREASE IN
COVERAGE BUT IT WILL REMAIN MOSTLY SUNNY. HIGHS WILL RANGE FROM
THE LOWER 40S NORTH TO THE UPPER 40S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE WILL REESTABLISH ITSELF OVER THE OHIO VALLEY
TONIGHT INTO TUESDAY. MEANWHILE...WEAK UPR LVL ENERGY WILL TRACK
ACROSS THE GREAT LAKES. RETURN LOW LEVEL FLOW MAY BRING SOME LOWER
CLOUDS TO OUR SE CWFA THIS EVENING/OVERNIGHT WHILE MID LVL
MOISTURE STREAMS IN FROM THE WEST. CLOUD COVER WILL PREVENT
TEMPERATURES FROM COOLING OFF TOO MUCH AND SHOULD RANGE FROM THE
MID 20S TO THE LOWER 30S. SKIES ON TUESDAY WILL RANGE FROM
PARTLY TO MOSTLY CLOUDY AS MID LVL MOISTURE CONTINUES TO ADVECT
ACROSS THE REGION FROM THE WEST. HIGHS WILL VARY FROM THE MID 40S
NORTH TO NEAR 50 SOUTH.
MODELS ARE IN GOOD AGREEMENT FOR TUESDAY NIGHT INTO WEDNESDAY.
SURFACE HIGH WILL MOVE EAST AS A WARM FRONT DEVELOPS TO OUR
SOUTHWEST. THE WARM FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY.
DEEP MOISTURE WILL INCREASE OVER THE REGION THROUGH THE PERIOD.
THIS MOISTURE WILL COINCIDE WITH A STRONG LOW LEVEL JET AND UPR
LVL DIVERGENCE FROM THE RR QUAD OF AN UPR LVL JET. THIS WILL
RESULT IN SHOWERS WITH THE HIGHEST THREAT POISED FOR THE NRN
ZONES. HAVE RAISED POPS TO CATEGORICAL ACRS NRN AREAS TUESDAY
NIGHT INTO WEDNESDAY. PCPN CHANCES WILL DIMINISH TO LOW CHANCE
SOUTH OF THE OHIO RIVER.
THE WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY NIGHT. THE
WARM FRONT WILL BE FOLLOWED BY A COLD FRONT WHICH WILL PUSH
SOUTHEAST ACROSS THE REGION ON THURSDAY. DEEP MOISTURE COUPLED
WITH DECENT LOW LEVEL FORCING AHEAD OF THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS. HAVE GONE WITH CATEGORICAL POPS. THE
FRONT WILL PUSH SOUTHEAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS
INTO THE WESTERN GREAT LAKES. THIS WILL BRING AN END TO THE PCPN.
TEMPERATURES TUESDAY NIGHT INTO THURSDAY NIGHT WILL EXHIBIT NON
DIURNAL TRENDS AND HAVE RELIED ON A BLEND OF RAW 2 M GFS AND ECMWF
FOR THE MOST PART.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND. A WEAK
SHORT WAVE MAY DROP DOWN ACROSS THE GREAT LAKES ON SATURDAY...BUT
IT LOOKS LIKE BETTER FORCING WITH THIS WILL REMAIN OFF TO OUR
NORTH SO WILL THEREFORE MAINTAIN A DRY FORECAST THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. COOLER AIR WILL FILTER IN
BEHIND THE FRONT LATE IN THE WEEK...LEADING TO A RETURN TO MORE
SEASONABLE TEMPERATURES THROUGH THE WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL MEANDER OVER THE UPPER OHIO VALLEY REGION
THROUGH THE NEXT DAY OR SO. THIS WILL BRING LIGHT TO CALM WINDS
(OCCASIONALLY UP TO AROUND 5 KNOTS OUT OF THE SOUTH). SOME CIRRUS
WILL SPILL INTO THE REGION TODAY...WITH MID CLOUDS POSSIBLE
OVERNIGHT AND EARLY TUESDAY.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...CONIGLIO/HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
627 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONS WEATHER INTO TUESDAY. THE
HIGH WILL MOVE EAST TUESDAY NIGHT AS A WARM FRONT APPROACHES THE
AREA FROM THE SOUTHWEST. THE WARM FRONT WILL PUSH ACROSS THE
REGION ON WEDNESDAY...FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT
INTO THURSDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND COAST
TO THE THE OHIO AND TENNESSEE VALLEYS THIS MORNING. THE HIGH IS
EXPECTED TO MOVE LITTLE TODAY. AFTER A COLD START...TEMPERATURES
ARE EXPECTED TO MODERATE UNDER ABUNDANT SUNSHINE. HIGHS WILL RANGE
FROM THE LOWER 40S NORTH TO THE UPPER 40S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE WILL REESTABLISH ITSELF OVER THE OHIO VALLEY
TONIGHT INTO TUESDAY. MEANWHILE...WEAK UPR LVL ENERGY WILL TRACK
ACROSS THE GREAT LAKES. RETURN LOW LEVEL FLOW MAY BRING SOME LOWER
CLOUDS TO OUR SE CWFA THIS EVENING/OVERNIGHT WHILE MID LVL
MOISTURE STREAMS IN FROM THE WEST. CLOUD COVER WILL PREVENT
TEMPERATURES FROM COOLING OFF TOO MUCH AND SHOULD RANGE FROM THE
MID 20S TO THE LOWER 30S. SKIES ON TUESDAY WILL RANGE FROM
PARTLY TO MOSTLY CLOUDY AS MID LVL MOISTURE CONTINUES TO ADVECT
ACROSS THE REGION FROM THE WEST. HIGHS WILL VARY FROM THE MID 40S
NORTH TO NEAR 50 SOUTH.
MODELS ARE IN GOOD AGREEMENT FOR TUESDAY NIGHT INTO WEDNESDAY.
SURFACE HIGH WILL MOVE EAST AS A WARM FRONT DEVELOPS TO OUR
SOUTHWEST. THE WARM FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY.
DEEP MOISTURE WILL INCREASE OVER THE REGION THROUGH THE PERIOD.
THIS MOISTURE WILL COINCIDE WITH A STRONG LOW LEVEL JET AND UPR
LVL DIVERGENCE FROM THE RR QUAD OF AN UPR LVL JET. THIS WILL
RESULT IN SHOWERS WITH THE HIGHEST THREAT POISED FOR THE NRN
ZONES. HAVE RAISED POPS TO CATEGORICAL ACRS NRN AREAS TUESDAY
NIGHT INTO WEDNESDAY. PCPN CHANCES WILL DIMINISH TO LOW CHANCE
SOUTH OF THE OHIO RIVER.
THE WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY NIGHT. THE
WARM FRONT WILL BE FOLLOWED BY A COLD FRONT WHICH WILL PUSH
SOUTHEAST ACROSS THE REGION ON THURSDAY. DEEP MOISTURE COUPLED
WITH DECENT LOW LEVEL FORCING AHEAD OF THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS. HAVE GONE WITH CATEGORICAL POPS. THE
FRONT WILL PUSH SOUTHEAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS
INTO THE WESTERN GREAT LAKES. THIS WILL BRING AN END TO THE PCPN.
TEMPERATURES TUESDAY NIGHT INTO THURSDAY NIGHT WILL EXHIBIT NON
DIURNAL TRENDS AND HAVE RELIED ON A BLEND OF RAW 2 M GFS AND ECMWF
FOR THE MOST PART.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND. A WEAK
SHORT WAVE MAY DROP DOWN ACROSS THE GREAT LAKES ON SATURDAY...BUT
IT LOOKS LIKE BETTER FORCING WITH THIS WILL REMAIN OFF TO OUR
NORTH SO WILL THEREFORE MAINTAIN A DRY FORECAST THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. COOLER AIR WILL FILTER IN
BEHIND THE FRONT LATE IN THE WEEK...LEADING TO A RETURN TO MORE
SEASONABLE TEMPERATURES THROUGH THE WEEKEND.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL MEANDER OVER THE UPPER OHIO VALLEY REGION
THROUGH THE NEXT DAY OR SO. THIS WILL BRING LIGHT TO CALM WINDS
(OCCASIONALLY UP TO AROUND 5 KNOTS OUT OF THE SOUTH). SOME CIRRUS
WILL SPILL INTO THE REGION TODAY...WITH MID CLOUDS POSSIBLE
OVERNIGHT AND EARLY TUESDAY.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
356 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONS WEATHER INTO TUESDAY. THE
HIGH WILL MOVE EAST TUESDAY NIGHT AS A WARM FRONT APPROACHES THE
AREA FROM THE SOUTHWEST. THE WARM FRONT WILL PUSH ACROSS THE
REGION ON WEDNESDAY...FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT
INTO THURSDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND COAST
TO THE THE OHIO AND TENNESSEE VALLEYS THIS MORNING. THE HIGH IS
EXPECTED TO MOVE LITTLE TODAY. AFTER A COLD START...TEMPERATURES
ARE EXPECTED TO MODERATE UNDER ABUNDANT SUNSHINE. HIGHS WILL RANGE
FROM THE LOWER 40S NORTH TO THE UPPER 40S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE WILL REESTABLISH ITSELF OVER THE OHIO VALLEY
TONIGHT INTO TUESDAY. MEANWHILE...WEAK UPR LVL ENERGY WILL TRACK
ACROSS THE GREAT LAKES. RETURN LOW LEVEL FLOW MAY BRING SOME LOWER
CLOUDS TO OUR SE CWFA THIS EVENING/OVERNIGHT WHILE MID LVL
MOISTURE STREAMS IN FROM THE WEST. CLOUD COVER WILL PREVENT
TEMPERATURES FROM COOLING OFF TOO MUCH AND SHOULD RANGE FROM THE
MID 20S TO THE LOWER 30S. SKIES ON TUESDAY WILL RANGE FROM
PARTLY TO MOSTLY CLOUDY AS MID LVL MOISTURE CONTINUES TO ADVECT
ACROSS THE REGION FROM THE WEST. HIGHS WILL VARY FROM THE MID 40S
NORTH TO NEAR 50 SOUTH.
MODELS ARE IN GOOD AGREEMENT FOR TUESDAY NIGHT INTO WEDNESDAY.
SURFACE HIGH WILL MOVE EAST AS A WARM FRONT DEVELOPS TO OUR
SOUTHWEST. THE WARM FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY.
DEEP MOISTURE WILL INCREASE OVER THE REGION THROUGH THE PERIOD.
THIS MOISTURE WILL COINCIDE WITH A STRONG LOW LEVEL JET AND UPR
LVL DIVERGENCE FROM THE RR QUAD OF AN UPR LVL JET. THIS WILL
RESULT IN SHOWERS WITH THE HIGHEST THREAT POISED FOR THE NRN
ZONES. HAVE RAISED POPS TO CATEGORICAL ACRS NRN AREAS TUESDAY
NIGHT INTO WEDNESDAY. PCPN CHANCES WILL DIMINISH TO LOW CHANCE
SOUTH OF THE OHIO RIVER.
THE WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY NIGHT. THE
WARM FRONT WILL BE FOLLOWED BY A COLD FRONT WHICH WILL PUSH
SOUTHEAST ACROSS THE REGION ON THURSDAY. DEEP MOISTURE COUPLED
WITH DECENT LOW LEVEL FORCING AHEAD OF THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS. HAVE GONE WITH CATEGORICAL POPS. THE
FRONT WILL PUSH SOUTHEAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS
INTO THE WESTERN GREAT LAKES. THIS WILL BRING AN END TO THE PCPN.
TEMPERATURES TUESDAY NIGHT INTO THURSDAY NIGHT WILL EXHIBIT NON
DIURNAL TRENDS AND HAVE RELIED ON A BLEND OF RAW 2 M GFS AND ECMWF
FOR THE MOST PART.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND. A WEAK
SHORT WAVE MAY DROP DOWN ACROSS THE GREAT LAKES ON SATURDAY...BUT
IT LOOKS LIKE BETTER FORCING WITH THIS WILL REMAIN OFF TO OUR
NORTH SO WILL THEREFORE MAINTAIN A DRY FORECAST THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. COOLER AIR WILL FILTER IN
BEHIND THE FRONT LATE IN THE WEEK...LEADING TO A RETURN TO MORE
SEASONABLE TEMPERATURES THROUGH THE WEEKEND.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL MEANDER OVER THE UPPER OHIO VALLEY REGION
THROUGH THE NEXT DAY OR SO. THIS WILL BRING LIGHT TO CALM WINDS
(OCCASIONALLY UP TO AROUND 5 KNOTS OUT OF THE SOUTH). SOME CIRRUS
WILL SPILL INTO THE REGION TODAY...BUT NO LOW CLOUDS ARE EXPECTED
AT THIS TIME.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
947 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED OVER THE MID ATLANTIC THROUGH MUCH OF
THE FIRST HALF OF THE WEEK. A MOIST FLOW OFF THE ATLANTIC AND NORTH
ACROSS FLORIDA AND GEORGIA WILL RESULT IN CLOUDY SKIES AND SOME RAIN
TODAY AND THEN DRIER WEATHER WILL RETURN INTO MID WEEK. A COLD
FRONT WILL APPROACH TOWARD THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM...WATER VAPOR IMAGERY AND RUC 500 MB HEIGHT FIELDS SHOW
A SHORTWAVE LIFTING NE THROUGH THE THE CENTRAL CAROLINAS MID
MORNING. THIS FEATURE SHOULD LIFT ANY LINGERING LIGHT PIEDMONT
PRECIPITATION EAST OF THE AREA BY NOON. LOW LEVEL WARM AND MOIST
ADVECTION WILL CONTINUE FROM THE SW...HOWEVER...SO THE CLOUDS SHOULD
BE HERE TO STAY OVER THE NOSE OF SFC HIGH PRES...WITH SLIGHT CHC TO
CHC POPS STILL WARRANTED FOR THE SW PART OF THE AREA THROUGH THE
AFTN. WILL MAINTAIN A DECENT GRADIENT ON MAX T FROM MID TO UPPER 40S
IN NE GA/WRN UPSTATE TO LOWER 50S INTERSTATE 77 AREA THIS AFTN.
THE SFC HIGH WILL RETROGRADE WWD TONIGHT AS HEIGHTS RISE ALOFT. 850
MB FLOW WILL STEADILY VEER W THEN NW THROUGH THE OVERNIGHT HOURS.
ANY SPRINKLES SHOULD BE CONFINED MAINLY TO MTN AREAS...WITH
DOWNSLOPING POSSIBLY ALLOWING SOME SCATTERING IN THE
FOOTHILLS/PIEDMONT CLOUDS. LINGERING CLOUDS AND LIGHT MIXING SHOULD
ALLOW MIN TEMPS TO RUN 5 TO 10 DEGREES ABOVE NORMAL MOST AREAS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 200 AM MONDAY...UPPER LEVEL HEIGHTS ATOP THE SE CONUS WILL BE
RISING ON TUESDAY. THE COOLISH NORTHERLY LLVL FLOW IS PROGGED TO
WEAKEN...AND AN ACCOMPANYING RISE IN 100-85H THICKNESS SHOULD BOOST
MAX TEMPS TO ABT 8 DEG F ABOVE CLIMO...AS PER THE LATEST MOS BLEND.
UPPER LEVEL RIDGE AXIS WILL CONTINUE TO BUILD EAST THRU WEDNESDAY...
ALIGNING ITSELF ATOP THE CWFA AND AIDING IN THE CONTINUATION OF FAIR
WX CONDITIONS. MILD LLVL RETURN FLOW INCREASES AND SHOULD SUPPORT
MAX TEMPS A FEW DEG F WARMER THAN PERSISTENCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 230 AM MONDAY...THE MEDIUM RANGE MODELS AGREE ON THE UPPER
RIDGE BREAKING DOWN OVER THE SOUTHEAST WITH THE AXIS FROM FLORIDA TO
EASTERN VIRGINIA EARLY THURSDAY. BY 00Z FRIDAY...THE RIDGE WILL
HAVE SIGNIFICANTLY FLATTENED OUT WITH THE STRONG SHORTWAVE CROSSING
THE GREAT LAKES. THE SLOW MOVING COLD FRONT WILL DRAPE SW TO NE
ACROSS THE SOUTHERN APPALACHIANS. FROM THURSDAY INTO THURSDAY NIGHT
WAVES OF LOW PRESSURE WILL ENHANCE PRECIP ALONG THE FRONT. THE
SUPPORTING ENERGY WILL MOVE OUT FRIDAY WITH VERY LITTLE RAIN OVER
THE AREA. THE NEW ECMWF BRINGS ANOTHER SHORTWAVE RAPIDLY ACROSS THE
PLAINS AND MISS VALLEY SATURDAY INDUCING THE SURFACE RESPONSE ACROSS
THE SOUTHEAST ALONG THE FRONT. THIS LAST BATCH OF RAIN WILL MOVE
EAST OF OUR AREA SATURDAY NIGHT. HIGH PRESSURE WILL BE IN CONTROL
SUNDAY AND SUNDAY NIGHT WITH DRY WEATHER. TEMPERATURES WILL BE
ABOVE NORMAL IN THE MEDIUM RANGE...MUCH ABOVE THURS AND FRI...THEN
ONLY A FEW DEGREES ABOVE NORMAL OVER THE WEEKEND FOR HIGH TEMPS.
WITH CLOUDINESS...LOWS WILL BE MUCH ABOVE NORMAL.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...A SURFACE RIDGE STRETCHING FROM THE DELMARVA
TO THE WESTERN CAROLINAS WILL MAINTAIN NE WINDS IN THE 5 TO 10 KT
RANGE THROUGHOUT TODAY...EXCEPT SOUTHEAST AT KAVL. THE SFC RIDGING
WILL ACTUALLY BUILD WWD TOWARD THE MTN CHAIN TONIGHT AS HEIGHTS RISE
FROM THE WEST ALOFT. WINDS WILL DIMINISH THIS EVENING. LOW VFR TO
MVFR STRATOCUMULUS WILL PERSIST ACROSS THE REGION IN MOIST...WARM
ADVECTION FLOW THROUGH THE DAY...BUT ANY LIGHT LINGERING PRECIP
SHOULD MOVE EAST OF THE AREA WITH AN UPPER LEVEL SHORTWAVE BY 18Z.
SOME LIGHT PRECIP COULD RETURN THIS EVENING FROM THE SW...BUT THIS
APPEARS UNLIKELY TO IMPACT ANY OF THE TAF SITES. WILL KEEP
CONDITIONS VFR THROUGH THE EVENING...WITH SCATTERING OVERNIGHT AS
850 MB FLOW TURNS A WESTERLY DOWNSLOPE.
OUTLOOK...GENERALLY DRY CONDITIONS SHOULD PERSIST UNTIL AT LEAST
THURSDAY...WHEN A COLD FRONT WILL APPROACH FROM THE WEST.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...HG
SHORT TERM...CSH
LONG TERM...DEO
AVIATION...HG
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1225 PM CST MON DEC 12 2011
.UPDATE...
AREAS OF FOG HAVE FOR THE MOST PART LIFTED ACROSS THE TEXAS AND
OKLAHOMA PANHANDLES THIS MORNING. POSSIBLE FOR PATCHY AREAS OF LIGHT
FOG TO CONTINUE EARLY THIS AFTERNOON BUT NOT EXPECTING FOG TO BECOME
MORE WIDE SPREAD GIVEN WIND SPEEDS AROUND 10 TO 20 MPH. THUS HAVE
OPTED TO LEAVE THIS OUT OF THE FORECAST FOR THIS AFTERNOON. OTHERWISE
EXPECT ANOTHER CLOUDY AND COOL DAY WITH HIGH TEMPS MAINLY IN THE 40S
TO NEAR 50 IN THE EASTERN TEXAS AND OKLAHOMA PANHANDLES. HAVE MADE
MINOR ADJUSTMENTS TO WIND AND SKY GRIDS TO ACCOUNT FOR CURRENT
TRENDS...BUT FOR THE MOST PART THE INHERITED FORECAST LOOKS TO BE ON
TRACK WITH NO OTHER AMENDMENTS NEEDED. UPDATED FORECAST PRODUCTS
HAVE BEEN SENT.
CLK
&&
.PREV DISCUSSION... /ISSUED 1156 AM CST MON DEC 12 2011/
AVIATION...
/18 UTC TAFS/ FOG AND LOW CLOUDS REMAIN THE MAIN AVIATION FORECAST
CONCERN FOR THIS FORECAST CYCLE.
AT KAMA...HAVE SEEN VISBYS IMPROVE AS THE FOG HAS SLOWLY LIFTED.
EXPECT VISBYS TO IMPROVE TO VFR BY 19 UTC...HOWEVER WILL CONTINUE TO
SEE LIFR CIGS THROUGH THE AFTERNOON. GUSTY SOUTHWEST WINDS THIS
MORNING WILL DIMINISH BUT STILL REMAIN BETWEEN 10-15 KTS THIS
AFTERNOON. LIGHT FOG WILL DEVELOP AT THE TERMINAL /AROUND 23Z/ BUT
NOT EXPECTING VISBYS TO REALLY DETEIORATE UNTIL CLOSER TO 06Z IN
AREAS OF FOG AND DRIZZLE. SHOULD SEE VISBYS IMPROVE BY 16 UTC TUESDAY
HOWEVER STILL EXPECT IFR CONDITIONS. WINDS WILL BACK MORE TO THE
SOUTHEAST WITH SPEEDS AGAIN BETWEEN 10-15 KTS.
AT KDHT/KGUY...CONDITIONS HAVE IMPROVED TO VFR BUT EXPECT THIS TO BE
FLEETING AS AREAS OF LIGHT FOG WITH CIGS AND VISBYS DETEIORATING TO
MVFR. SIMILAR TO KAMA...EXPECT AREAS OF DRIZZLE AND FOG TO DEVELOP
AROUND 03 UTC WHICH WILL CAUSE CONDITIONS TO LOWER TO LIFR. SHOULD
SEE VISBYS AND CIGS IMPROVE TO IFR AT THE END OFF THE FORECAST
PERIOD. WINDS WILL BE LIGHTER AT KDHT/KGUY AS THE EFFECTS A 45-50 KT
LOW LEVEL JET WILL BE MORE PRONOUNCED ACROSS THE SOUTHERN TEXAS
PANHANDLE.
CLK
PREV DISCUSSION... /ISSUED 556 AM CST MON DEC 12 2011/
AVIATION...
FOR THE 12Z TAFS...GENERALLY HAVE LOW TO MODERATE CONFIDENCE AT
ALL SITES.
AT KAMA...BELIEVE IFR OR LOWER CONDITIONS WILL PREVAIL FOR AT LEAST
THE NEXT 24 HOURS AND WENT WITH A MORE PESSIMISTIC FORECAST IN
REGARDS TO CEILINGS/VISIBILITIES. CONFIDENCE IS MODERATE THAT VLIFR
CONDITIONS WILL OCCUR THROUGH 16Z...THEN SOME IMPROVEMENT 16-24Z...
BEFORE CONDITIONS DETERIORATE AFTER 00Z. HAVE MODERATE CONFIDENCE THAT
LIFR CONDITIONS OR LOWER WILL OCCUR AFTER 00Z. -DZ WILL LIKELY OCCUR
AFTER 02Z.
AT KDHT...THINK IFR CONDITIONS WILL IMPROVE TO AT LEAST MVFR IF NOT
BETTER 17-20Z. DETERIORATING CONDITIONS WILL LIKELY OCCUR AFTER
00Z. HAVE LOW CONFIDENCE FOR LIFR CONDITIONS AFTER 04Z.
AT KGUY...HAVE MODERATE CONFIDENCE THAT CONDITIONS WILL IMPROVE TO
VFR 16-20Z...BEFORE DETERIORATING AFTER 22Z...ESPECIALLY AFTER 06Z.
HAVE VERY LOW CONFIDENCE FOR LIFR CONDITIONS AFTER 11Z.
MBS
PREV DISCUSSION... /ISSUED 443 AM CST MON DEC 12 2011/
DISCUSSION...
TODAY-TONIGHT: HAVE SEEN SOME PATCHY AREAS OF FOG ACROSS THE
PANHANDLES THIS MORNING...BUT STRONGER SURFACE WINDS HAVE PRECLUDED
ANY DENSE FOG CONCERNS. EXPECT PATCHY FOG TO CONTINUE THROUGH MOST
OF THE MORNING HOURS SOUTH AND EAST OF A LINE FROM DALHART TO GUYMON.
MUCH LOWER VISIBILITIES HAVE BEEN NOTED ACROSS THE SOUTH PLAINS WHERE
SURFACE/LOW-LEVEL WINDS HAVE WEAKENED...PER KLBB VAD DATA. RUC DATA
INDICATES WINDS ACROSS THE PANHANDLES MAY ALSO WEAKEN...AND IF THIS
OCCURS...VISIBILITIES WILL LIKELY DETERIORATE. STILL NOT EXPECTING
ANY DENSE FOG ISSUES AS SURFACE WINDS SHOULD REMAIN ABOVE 10
MPH...BUT WILL MONITOR CLOSELY. WOULDN/T BE SURPRISED TO SEE SOME
DRIZZLE ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE THROUGH 9 AM WHERE
FORECAST SOUNDINGS INDICATE THE LOW-LEVEL MOISTURE WILL REMAIN
AROUND 2000 FT DEEP...BUT SINCE THIS IS ON THE MARGINAL END FOR
DRIZZLE...LEFT OUT OF THE FORECAST FOR NOW. OTHERWISE...EXPECT MOST
OF THE AREA TO REMAIN GRUNGED IN WITH LOW CLOUDS FOR MOST OF THE DAY.
AS A RESULT...HIGH TEMPERATURES WILL CONTINUE TO REMAIN BELOW
SEASONAL NORMS. IT IS INTERESTING TO NOTE THAT THE AVERAGE DAILY
TEMPERATURE AT AMARILLO...BORGER...DALHART...AND GUYMON HAS NOT BEEN
ABOVE NORMAL SINCE NOVEMBER 30. AS ISENTROPIC ASCENT INCREASES THIS
EVENING AND OVERNIGHT...PRECIPITATION CHANCES WILL ALSO INCREASE. QPF
AMOUNTS WILL BE LIGHT WITH MOST LOCATIONS SEEING LESS THAN 0.10"
THROUGH SUNRISE ON TUESDAY. EXPECTING THE PRECIPITATION TYPE TO BE
ALL LIQUID AS WARM AIR ADVECTION...MOISTURE ADVECTION...AND LOW
CLOUDS SHOULD KEEP TEMPERATURES ABOVE FREEZING. ONCE AGAIN...ANOTHER
ROUND OF PATCHY FOG IS EXPECTED DEVELOP AREAWIDE...BUT THE RAIN SHOULD
KEEP THE NEAR GROUND AIR MIXED ENOUGH TO LIMIT ANY DENSE FOG
CONCERNS.
TUESDAY-TUESDAY NIGHT: PATCHY FOG MAY LINGER INTO THE LATE MORNING
HOURS ON TUESDAY. OTHERWISE...ANOTHER DREARY DAY IS EXPECTED WITH LOW
CLOUDS AND INCREASING PRECIPITATION CHANCES...ESPECIALLY AFTER NOON.
MAX TEMPS WILL ONCE AGAIN BE ON THE COOL SIDE. MET AND MAV GUIDANCE
APPEAR TOO HIGH...SO FOLLOWED RAW NAM TEMPERATURES CLOSELY. BY
TUESDAY AFTERNOON...FORECAST SOUNDINGS INDICATE SOME WEAK ELEVATED
INSTABILITY DEVELOPING ACROSS MOST OF THE PANHANDLES AS LOW-LEVEL
MOISTURE INCREASES AND MID-LEVEL LAPSE RATES STEEPEN. KEPT
THUNDERSTORMS IN THE FORECAST AND SHIFTED THEM SLIGHTLY WESTWARD.
STRONGER MOISTURE ADVECTION IS EXPECTED ACROSS MOST OF THE AREA ON
TUESDAY NIGHT....AND IN FACT...THE ECMWF...GGEM...AND GFS ALL SHOW
SURFACE DEW POINTS IN THE MID TO UPPER 50S ACROSS THE SOUTHEAST TEXAS
PANHANDLE! IT/S AMAZING TO REALIZE THAT WE STRUGGLED TO SEE DEW
POINTS THAT HIGH DURING THE SPRING AND SUMMER...BUT IT/S POSSIBLE
THEY MAY REACH THAT HIGH IN DECEMBER. REGARDLESS...AS FORCING FOR
ASCENT IMPINGES ON THE MOIST AND WEAKLY UNSTABLE AIR
MASS...PRECIPITATION AND THUNDERSTORM CHANCES WILL REALLY RAMP UP
TUESDAY EVENING AND NIGHT. WITHIN THE LAST COUPLE OF WEEKS...HAVE
NOTICED THAT THE SUBTROPICAL JET HAS HAD A CONNECTION TO THE
TROPICS...AND THIS LOOKS TO BE THE CASE AGAIN WITH THIS SYSTEM. AS A
RESULT...WON/T BE SURPRISED TO SEE RAINFALL AMOUNTS OVERACHIEVE IN
SOME LOCATIONS. REGARDING THUNDERSTORM POTENTIAL...FORECAST
SOUNDINGS ARE SHOWING UP TO 300 J/KG OF MUCAPE ALONG WITH DEEP LAYER
SHEAR AROUND 70 KT. AS A RESULT...MAY SEE A FEW STRONG STORMS PRODUCE
SMALL HAIL TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. NOT EXPECTING ANY
WINTRY PRECIPITATION AS SURFACE AND LOW-LEVEL TEMPERATURES WILL
REMAIN ABOVE FREEZING.
WEDNESDAY-WEDNESDAY NIGHT: THE DRY SLOT WILL QUICKLY SWEEP ACROSS THE
FORECAST AREA DURING THE DAY. THERE MAY BE ENOUGH LINGERING LOW-
LEVEL MOISTURE ACROSS THE FAR EASTERN PANHANDLES DURING THE MORNING
FOR A CHANCE OF PRECIPITATION. KEPT THUNDERSTORMS IN THE
FORECAST...BUT FORECAST SOUNDINGS INDICATING LESS THAN 50 J/KG OF
MUCAPE. THANKS TO THE DRY SLOT...THE SUN WILL MAKE AN APPEARANCE
ACROSS THE REGION. HIGH TEMPERATURES SHOULD BE ABLE TO RISE INTO THE
50S AND POSSIBLY 60S AS STRONG DOWNSLOPING WINDS DEVELOP. SPEAKING OF
THE WINDS...EXPECT THEM TO STRENGTHEN BY LATE WEDNESDAY MORNING INTO
THE MID-AFTERNOON HOURS. FORECAST SOUNDINGS INDICATE MIXING HEIGHTS WILL
BE RELATIVELY SHALLOW AND WILL NOT BE ABLE TO TAP INTO THE HIGH
MOMENTUM MID-LEVEL AIR. NONETHELESS...FORECAST SOUNDINGS ARE SHOWING
30-35 KT FLOW AT THE TOP OF THE BOUNDARY LAYER. CONTINUED TO KEEP
WINDS BELOW ADVISORY CRITERIA...ESPECIALLY SINCE MET WINDS ARE
TRENDING LOWER. HOWEVER...IF THE GFS IS CORRECT...COULD SEE ADVISORY
LEVEL WINDS...ESPECIALLY ON THE CAPROCK. AS THE UPPER TROUGH AND
ATTENDANT SURFACE LOW MOVE INTO THE UPPER MISSISSIPPI VALLEY...A COLD
FRONT WILL PUSH SOUTHWARD ACROSS THE PANHANDLES WITH MUCH COOLER AND
DRIER AIR FILTERING INTO THE AREA. AS THE AFOREMENTIONED SYNOPTIC
FEATURES PULL AWAY FROM THE AREA...THE PRESSURE GRADIENT WILL ALSO
RELAX...ALLOWING WINDS TO QUICKLY SUBSIDE UNDER 10 MPH BY SUNRISE
THURSDAY.
THURSDAY-THURSDAY NIGHT: DRY AND SUB-SEASONAL TEMPERATURES ARE
EXPECTED AS NNE UPSLOPE WINDS PREVAIL THROUGH THE DAY. DUE TO THE
UPSLOPE WINDS...LOWERED HIGHS IN ALL AREAS. A CHILLY NIGHT IS
EXPECTED WITH LOWS IN THE 20S AND LOWER 30S.
FRIDAY-MONDAY: STILL A LOT OF UNCERTAINTIES DURING THIS TIME PERIOD.
THE DGEX AND GFS CONTINUE TO REMAIN FASTER WITH THE CUTOFF LOW THAN
THE ECMWF AND GGEM. JUST NOTICED THE NEW 06 UTC GFS HAS NOW TRENDED
SLOWER WITH THE CLOSED LOW AND IS MORE SIMILAR TO THE ECMWF AND
GGEM. EXPECT PRECIPITATION TO DEVELOP ACROSS THE SOUTHWEST TEXAS
PANHANDLE SATURDAY EVENING BEFORE SPREADING ACROSS ALL OF THE
FORECAST AREA SATURDAY NIGHT. RAIN IS LIKELY SATURDAY EVENING AND
THEN POSSIBLY MIXING WITH OR CHANGING TO SNOW SATURDAY NIGHT. SOME
INDICATIONS THAT LOW-LEVEL THERMAL PROFILES MAY BE A LITTLE WARM FOR
SNOW...BUT DUE TO THE UNCERTAINTY...KEPT A RAIN/SNOW MIX IN THE
FORECAST. BEYOND SUNDAY...CONSIDERABLE UNCERTAINTY EXISTS...BUT
FOLLOWED MORE CLOSELY TO THE ECMWF FOR NOW. IF IT DOES VERIFY...WE
COULD BE LOOKING AT MORE WINTER MISCHIEF BY EARLY NEXT WEEK. STILL
PLENTY OF TIME TO WATCH THIS SYSTEM SO STAY TUNED.
JACKSON
FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE EXPECTED TO REMAIN ABOVE 30 PERCENT
ACROSS ALL OF THE PANHANDLES FOR THE NEXT SEVEN DAYS. AS A
RESULT...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/03
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1158 AM CST MON DEC 12 2011
.DISCUSSION...SEE AVIATION AND SHORT TERM SECTIONS FOR UPDATES.
&&
.SHORT TERM UPDATE /THIS AFTERNOON/...NOTHING TOO EARTH-SHAKING
BUT DID TWEAK TEMPERATURES DOWN SEVERAL DEGREES ACROSS THE BOARD BASED
ON CURRENT TRENDS...AS WELL AS RUC AND NAM DATA. SOUTHEAST FLOW
JUST OFF THE DECK IS TRYING HARD TO ERODE THE CLOUD MASS NEAR THE
COAST AND HAVING MODEST SUCCESS...BUT TEMPERATURES WILL STRUGGLE
TO THE 75/76 RANGE AS PREVIOUSLY FORECAST AND HAVE DIPPED TO THE
LOWER 70S. FARTHER WEST AND NORTH...MAINLY WEST OF HIGHWAY
281...THE COLD AIR IS STILL TRAPPED AND MAY BARELY ERODE BEFORE
SUNSET. MCALLEN THROUGH WESTERN BROOKS LOOKS LIKE THE EDGE...WITH
AREAS TO THE WEST TOTALLY SOCKED IN ANOTHER DAY. THIS WILL KEEP
TEMPERATURES FROM REACHING MUCH ABOVE 60 AND HAVE LOWERED HIGHS 3
TO 5 DEGREES HERE AS WELL.
THE OTHER BIG STORY WILL BE EXPECTATION FOR DENSE FOG OVERNIGHT.
MORE IN THE AFTERNOON DISCUSSION AT AROUND 2 PM. SEE PRELIMINARY
NUMBERS BELOW FOR ADJUSTMENTS./52-BSG/
.AVIATION...SOUTHEAST FLOW TRYING TO REACH THE SURFACE HAS HELPED
PUSH BREAKS INTO THE LOWER VALLEY (KHRL/KBRO)...AND CEILINGS HAVE RESPONDED
BY LIFTING INTO VFR RANGE. WINDS DEAD CALM AT 18Z BUT SHOULD
INCREASE A HAIR FROM THE EAST OR EAST/SOUTHEAST FOR A FEW HOURS
BEFORE SETTLING BACK TO LIGHT...BUT IMPORTANT...SPEEDS OVERNIGHT.
EXPECT CEILINGS TO TUMBLE BACK TO IFR TOWARD MIDNIGHT AND
VISIBILITY TO FOLLOW AFTER MIDNIGHT...CONTINUING THROUGH MID
MORNING BEFORE RAIPDLY BREAKING WITH SOUTHEAST WINDS PICKING UP TO
NEAR 10 KNOTS...AND JUMPING MUCH HIGHER RIGHT AROUND 18Z.
LIFE IS DIFFERENT 40 TO 50 MILES TO THE WEST. KMFE REMAINS IN IFR
BUT SHOULD HESITANTLY BREAK TO THE EDGE OF MVFR BEFORE 20Z...WITH
VISIBILITY NO ISSUE THIS AFTERNOON. OVERNIGHT WILL BE ANOTHER
ISSUE. CURRENT DATA FROM THE NAM 3 HOUR FORECAST
SOUNDINGS...ALONG WITH IDEA THAT TEMPERATURE AND DEWPOINT WILL
REMAIN STEADY OR SLOWLY RISE A DEGREE OR TWO WILL SET UP HIGH
POTENTIAL FOR DENSE FOG AND LOW CEILINGS...LIFR/LIFR WITH CALM
WINDS. LOWEST CONDITIONS WILL COINCIDE WITH EARLY MORNING PREP AND
FLIGHTS...AND DELAYS ARE A GOOD BET INTO AND OUT OF MCALLEN.
HAVE ISSUED A RARE PREVAILING LIFR CEILING/VISIBILITY
FORECAST...WITH A GRADUAL LIFT THROUGH LATE MORNING AND A MORE
RAPID RISE TOWARD NOON.
FINALLY...AT ALL TERMINALS...LOW LEVEL WIND SHEAR WILL BE NOTABLE
BUT NOT ENOUGH TO ADD WITH SPEEDS HOLDING AT OR BELOW 25 KNOTS
THROUGH 12Z WITHIN THE 500 TO 2000 FOOT LAYER./52-BSG/
&&
.PREV DISCUSSION... /ISSUED 526 AM CST MON DEC 12 2011/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...CIGS HAVE FALLEN BELOW 500 FEET AT ALL LOCATIONS THIS
MORNING...WITH FOG BEGINNING TO LOWER BELOW 3 MILES. CONDITIONS
SHOULD IMPROVE AFTER SUNRISE...WITH CIGS REACHING 300 FEET BY
NOON. SOME BINOVC STILL EXPECTED LATE AFTERNOON...BUT CIGS THICKEN
BACK UP AFTER SUNSET. STILL LOOKING AT MORE FOG TONIGHT...AND HAS
GOOD CHANCE OF BEING DENSER AND STARTING EARLIER IN THE EVENING.
LIGHT WINDS WILL SHIFT SOUTHEAST AND INCREASE TO 10 TO 15 KNOTS
DURING THE AFTERNOON. WINDS WILL RETURN TO L/V AFTER SUNSET.
PREV DISCUSSION... /ISSUED 406 AM CST MON DEC 12 2011/
SHORT TERM .SHORT TERM /MONDAY THROUGH TUESDAY/...OVERCAST SKIES CONTINUE
WITH OCCASIONAL DRIZZLE AND LIGHT RAIN AS THE COASTAL TROUGH
CONTINUES TO INDUCE OVERRUNNING AREAWIDE. WEAK RIDGING ALOFT WILL
BEGIN TO HELP BREAK DOWN THE SFC TROUGH THIS AFTERNOON...BRINGING
OVERRUNNING PRECIP TO AN END. CLOUD COVER WILL REMAIN MOSTLY
OVERCAST TODAY...WITH BREAKS FINALLY STARTING TO SHOW UP LATE
AFTERNOON. LIGHT WINDS AND ABUNDANT MOISTURE WILL SET THE STAGE
FOR FOG FORMATION OVERNIGHT TONIGHT. LLVL MOISTURE AND INSTABILITY
FROM A WEAK SHORTWAVE ROTATING AROUND THE GULF RIDGE WILL BRING
ANOTHER CHANCE FOR MORE SHOWERY PRECIPITATION DURING THE DAY
TUESDAY. HAVE NUDGED POP CHANCES UP ACCORDINGLY...BUT RAINS WILL
NOT BE WIDESPREAD AS IN PREVIOUS DAYS.
TEMPERATURES WILL HAVE A BETTER CHANCE TO REACH INTO THE 60S
TODAY...WITH HIGHEST READINGS WHERE ANY BREAKS IN CLOUD COVER OCCUR.
LOWS TONIGHT WILL ONLY REACH THE LOW TO MID 60S DUE TO FURTHER
INCREASES OF LLVL MOISTURE ACROSS THE REGION. TEMPS TUESDAY REACH
FURTHER INTO THE 70S...POSSIBLY REACHING 80...WITH BETTER AMOUNTS OF
SUNSHINE.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...PROGRESSIVE SPLIT FLOW
PATTERN ACROSS NORTH AMERICA TO MAINTAIN AN UNSETTLED WET AND
MILD FORECAST FOR ALL OF DEEP SOUTH TEXAS AND RIO GRANDE RIVER.
THIS UN LA NINA LIKE SET UP WILL BE DIFFICULT TO TIME THE SEVERAL
SHORTWAVE TROUGHS TRACKING STEADILY FROM THE WEST COAST THROUGH
THE DESERT SOUTHWEST AND INTO THE PLAINS. BOTH GFS AND ECMWF ARE
UNCANNY SIMILAR SO FORECAST CONFIDENCE IS ABOVE AVERAGE. AS
MENTIONED BIG QUESTIONS ARISE WITH TIMING OF SHORTWAVE AND
STRENGTH OF SHORTWAVES AND THE MAIN UPPER TROUGH. DO NOT SEE ANY
SIGNIFICANT COLD AIR SURGES MAKING THIS FAR SOUTH WITH THE
NORTHERN JET REMAINING ALONG THE CANADIAN BORDER DIPPING INTO THE
MIDWEST STATES. A MORE MILD MARITIME AIRMASS WILL KEEP OUR
TEMPERATURES ABOVE NORMAL MUCH OF THE LONG TERM. MOISTURE FIELDS
LOOK MODEST THROUGH THE MIDDLE HALF OF THE WEEK WITH DEEPER
MOISTURE SEEN FOR NEXT FRIDAY AND SATURDAY SIMILAR TO WHAT WAS
EXPERIENCED THIS PASS WEEKEND.
WILL START OUT WITH A BREEZY TO WINDY WEDNESDAY AS A STORM SYSTEM
LIFTS OUT OF THE 4 CORNERS REGION. GFS SUGGEST A STRONG LOW LEVEL
JET DEVELOPING AND WITH THE FINALLY PEAKING OUT MODEST MIXING OF
THE STRONGER WINDS ARE ANTICIPATED. THIS WILL PUSH TEMPERATURES
INTO THE LOWER 80S MOST LOCATIONS. RAIN CHANCES ARE NEAR NIL.
SHOWERS RETURN TO THE FORECAST THURSDAY AS ANOTHER COASTAL TROUGH
IS PROGGED TO DEVELOP. THIS TROUGH BECOMES ENHANCED FRIDAY AND
SATURDAY AS A LARGE UPPER TROUGH DIGS INTO THE SW DESERTS. A COLD
FRONT BEGINS TO ADVANCE TOWARDS THE CWA DURING THE LATER HALF OF
THE WEEK POSSIBLE DRAPING ITSELF ACROSS THE REGION ON SATURDAY.
GRIDDS SHOW CHANCE POPS AT THIS TIME AS DOES THE MODEL GUIDANCE
THIS WILL LIKELY BECOME MORE DEFINED AS WE APPROACH NEXT WEEKEND.
TEMPERATURES TO FALL DUE TO THE INCREASE IN CLOUDS...RAIN AND
POSSIBLE COLD FRONT PASSAGE.
MARINE...
NOW THROUGH TUESDAY...BREEZY CONDITIONS IN THE VICINITY OF THE SFC
COASTAL TROUGH CONTINUE TO PRODUCE WINDS AROUND 20 KNOTS AND SEAS 6
TO 7 FEET OFFSHORE. WINDS HAVE BEGUN TO DECREASE SLOWLY AS THE
TROUGH BEGINS TO WEAKEN OFFSHORE. SMALL CRAFT ADVISORIES REMAIN FOR
THE GULF WATERS THROUGH 6AM...AND WITH SLOWLY IMPROVING CONDITIONS
EXPECTED...WILL NOT BE ANTICIPATING EXTENDING ADVISORIES FURTHER.
BREEZY CONDITIONS WILL STILL BE ABLE TO KEEP SEAS ELEVATED AT 6 TO 7
FEET TODAY...FALLING TO 4 TO 5 FEET TUESDAY AFTERNOON.
TUESDAY NIGHT THROUGH FRIDAY...AN INCREASE IN WINDS AND SEAS ARE
ANTICIPATED TUESDAY NIGHT INTO WEDNESDAY AS STORM SYSTEM TRACKS
INTO INTO THE CENTRAL PLAINS. PRESSURE GRADIENT TO TIGHTEN AS
PRESSURES LOWER COMBINING WITH BROAD HIGH PRESSURE OVER THE GULF.
SMALL CRAFT ADVISORIES ARE LIKELY. WINDS TO RELAX THURSDAY AND
FRIDAY BUT SEAS WILL BE SLOW TO SUBSIDE WITH A PERSISTENT EAST FLOW
ACROSS THE GULF PRODUCING A MODERATE LONG PERIOD SWELL. UNCERTAIN
HOW HIGH THE SWELL GETS OR HOW LOW IT MIGHT FALL BUT AT LEAST
EXERCISE CAUTION WORDING IS ANTICIPATED. RAIN CHANCES INCREASE
THURSDAY WITH EVEN HIGHER CHANCES FRIDAY AND SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 71 67 76 66 / 20 10 20 10
BROWNSVILLE 70 65 78 65 / 20 10 20 10
HARLINGEN 72 64 79 64 / 30 10 20 10
MCALLEN 66 64 82 65 / 30 10 20 10
RIO GRANDE CITY 60 59 80 62 / 40 10 20 10
SOUTH PADRE ISLAND 69 68 73 67 / 20 10 20 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR GMZ150-
155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1156 AM CST MON DEC 12 2011
.AVIATION...
/18 UTC TAFS/ FOG AND LOW CLOUDS REMAIN THE MAIN AVIATION FORECAST
CONCERN FOR THIS FORECAST CYCLE.
AT KAMA...HAVE SEEN VISBYS IMPROVE AS THE FOG HAS SLOWLY LIFTED.
EXPECT VISBYS TO IMPROVE TO VFR BY 19 UTC...HOWEVER WILL CONTINUE TO
SEE LIFR CIGS THROUGH THE AFTERNOON. GUSTY SOUTHWEST WINDS THIS
MORNING WILL DIMINISH BUT STILL REMAIN BETWEEN 10-15 KTS THIS
AFTERNOON. LIGHT FOG WILL DEVELOP AT THE TERMINAL /AROUND 23Z/ BUT
NOT EXPECTING VISBYS TO REALLY DETEIORATE UNTIL CLOSER TO 06Z IN
AREAS OF FOG AND DRIZZLE. SHOULD SEE VISBYS IMPROVE BY 16 UTC TUESDAY
HOWEVER STILL EXPECT IFR CONDITIONS. WINDS WILL BACK MORE TO THE
SOUTHEAST WITH SPEEDS AGAIN BETWEEN 10-15 KTS.
AT KDHT/KGUY...CONDITIONS HAVE IMPROVED TO VFR BUT EXPECT THIS TO BE
FLEETING AS AREAS OF LIGHT FOG WITH CIGS AND VISBYS DETEIORATING TO
MVFR. SIMILAR TO KAMA...EXPECT AREAS OF DRIZZLE AND FOG TO DEVELOP
AROUND 03 UTC WHICH WILL CAUSE CONDITIONS TO LOWER TO LIFR. SHOULD
SEE VISBYS AND CIGS IMPROVE TO IFR AT THE END OFF THE FORECAST
PERIOD. WINDS WILL BE LIGHTER AT KDHT/KGUY AS THE EFFECTS A 45-50 KT
LOW LEVEL JET WILL BE MORE PRONOUNCED ACROSS THE SOUTHERN TEXAS
PANHANDLE.
CLK
&&
.PREV DISCUSSION... /ISSUED 556 AM CST MON DEC 12 2011/
AVIATION...
FOR THE 12Z TAFS...GENERALLY HAVE LOW TO MODERATE CONFIDENCE AT
ALL SITES.
AT KAMA...BELIEVE IFR OR LOWER CONDITIONS WILL PREVAIL FOR AT LEAST
THE NEXT 24 HOURS AND WENT WITH A MORE PESSIMISTIC FORECAST IN
REGARDS TO CEILINGS/VISIBILITIES. CONFIDENCE IS MODERATE THAT VLIFR
CONDITIONS WILL OCCUR THROUGH 16Z...THEN SOME IMPROVEMENT 16-24Z...
BEFORE CONDITIONS DETERIORATE AFTER 00Z. HAVE MODERATE CONFIDENCE THAT
LIFR CONDITIONS OR LOWER WILL OCCUR AFTER 00Z. -DZ WILL LIKELY OCCUR
AFTER 02Z.
AT KDHT...THINK IFR CONDITIONS WILL IMPROVE TO AT LEAST MVFR IF NOT
BETTER 17-20Z. DETERIORATING CONDITIONS WILL LIKELY OCCUR AFTER
00Z. HAVE LOW CONFIDENCE FOR LIFR CONDITIONS AFTER 04Z.
AT KGUY...HAVE MODERATE CONFIDENCE THAT CONDITIONS WILL IMPROVE TO
VFR 16-20Z...BEFORE DETERIORATING AFTER 22Z...ESPECIALLY AFTER 06Z.
HAVE VERY LOW CONFIDENCE FOR LIFR CONDITIONS AFTER 11Z.
MBS
PREV DISCUSSION... /ISSUED 443 AM CST MON DEC 12 2011/
DISCUSSION...
TODAY-TONIGHT: HAVE SEEN SOME PATCHY AREAS OF FOG ACROSS THE
PANHANDLES THIS MORNING...BUT STRONGER SURFACE WINDS HAVE PRECLUDED
ANY DENSE FOG CONCERNS. EXPECT PATCHY FOG TO CONTINUE THROUGH MOST
OF THE MORNING HOURS SOUTH AND EAST OF A LINE FROM DALHART TO GUYMON.
MUCH LOWER VISIBILITIES HAVE BEEN NOTED ACROSS THE SOUTH PLAINS WHERE
SURFACE/LOW-LEVEL WINDS HAVE WEAKENED...PER KLBB VAD DATA. RUC DATA
INDICATES WINDS ACROSS THE PANHANDLES MAY ALSO WEAKEN...AND IF THIS
OCCURS...VISIBILITIES WILL LIKELY DETERIORATE. STILL NOT EXPECTING
ANY DENSE FOG ISSUES AS SURFACE WINDS SHOULD REMAIN ABOVE 10
MPH...BUT WILL MONITOR CLOSELY. WOULDN/T BE SURPRISED TO SEE SOME
DRIZZLE ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE THROUGH 9 AM WHERE
FORECAST SOUNDINGS INDICATE THE LOW-LEVEL MOISTURE WILL REMAIN
AROUND 2000 FT DEEP...BUT SINCE THIS IS ON THE MARGINAL END FOR
DRIZZLE...LEFT OUT OF THE FORECAST FOR NOW. OTHERWISE...EXPECT MOST
OF THE AREA TO REMAIN GRUNGED IN WITH LOW CLOUDS FOR MOST OF THE DAY.
AS A RESULT...HIGH TEMPERATURES WILL CONTINUE TO REMAIN BELOW
SEASONAL NORMS. IT IS INTERESTING TO NOTE THAT THE AVERAGE DAILY
TEMPERATURE AT AMARILLO...BORGER...DALHART...AND GUYMON HAS NOT BEEN
ABOVE NORMAL SINCE NOVEMBER 30. AS ISENTROPIC ASCENT INCREASES THIS
EVENING AND OVERNIGHT...PRECIPITATION CHANCES WILL ALSO INCREASE. QPF
AMOUNTS WILL BE LIGHT WITH MOST LOCATIONS SEEING LESS THAN 0.10"
THROUGH SUNRISE ON TUESDAY. EXPECTING THE PRECIPITATION TYPE TO BE
ALL LIQUID AS WARM AIR ADVECTION...MOISTURE ADVECTION...AND LOW
CLOUDS SHOULD KEEP TEMPERATURES ABOVE FREEZING. ONCE AGAIN...ANOTHER
ROUND OF PATCHY FOG IS EXPECTED DEVELOP AREAWIDE...BUT THE RAIN SHOULD
KEEP THE NEAR GROUND AIR MIXED ENOUGH TO LIMIT ANY DENSE FOG
CONCERNS.
TUESDAY-TUESDAY NIGHT: PATCHY FOG MAY LINGER INTO THE LATE MORNING
HOURS ON TUESDAY. OTHERWISE...ANOTHER DREARY DAY IS EXPECTED WITH LOW
CLOUDS AND INCREASING PRECIPITATION CHANCES...ESPECIALLY AFTER NOON.
MAX TEMPS WILL ONCE AGAIN BE ON THE COOL SIDE. MET AND MAV GUIDANCE
APPEAR TOO HIGH...SO FOLLOWED RAW NAM TEMPERATURES CLOSELY. BY
TUESDAY AFTERNOON...FORECAST SOUNDINGS INDICATE SOME WEAK ELEVATED
INSTABILITY DEVELOPING ACROSS MOST OF THE PANHANDLES AS LOW-LEVEL
MOISTURE INCREASES AND MID-LEVEL LAPSE RATES STEEPEN. KEPT
THUNDERSTORMS IN THE FORECAST AND SHIFTED THEM SLIGHTLY WESTWARD.
STRONGER MOISTURE ADVECTION IS EXPECTED ACROSS MOST OF THE AREA ON
TUESDAY NIGHT....AND IN FACT...THE ECMWF...GGEM...AND GFS ALL SHOW
SURFACE DEW POINTS IN THE MID TO UPPER 50S ACROSS THE SOUTHEAST TEXAS
PANHANDLE! IT/S AMAZING TO REALIZE THAT WE STRUGGLED TO SEE DEW
POINTS THAT HIGH DURING THE SPRING AND SUMMER...BUT IT/S POSSIBLE
THEY MAY REACH THAT HIGH IN DECEMBER. REGARDLESS...AS FORCING FOR
ASCENT IMPINGES ON THE MOIST AND WEAKLY UNSTABLE AIR
MASS...PRECIPITATION AND THUNDERSTORM CHANCES WILL REALLY RAMP UP
TUESDAY EVENING AND NIGHT. WITHIN THE LAST COUPLE OF WEEKS...HAVE
NOTICED THAT THE SUBTROPICAL JET HAS HAD A CONNECTION TO THE
TROPICS...AND THIS LOOKS TO BE THE CASE AGAIN WITH THIS SYSTEM. AS A
RESULT...WON/T BE SURPRISED TO SEE RAINFALL AMOUNTS OVERACHIEVE IN
SOME LOCATIONS. REGARDING THUNDERSTORM POTENTIAL...FORECAST
SOUNDINGS ARE SHOWING UP TO 300 J/KG OF MUCAPE ALONG WITH DEEP LAYER
SHEAR AROUND 70 KT. AS A RESULT...MAY SEE A FEW STRONG STORMS PRODUCE
SMALL HAIL TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. NOT EXPECTING ANY
WINTRY PRECIPITATION AS SURFACE AND LOW-LEVEL TEMPERATURES WILL
REMAIN ABOVE FREEZING.
WEDNESDAY-WEDNESDAY NIGHT: THE DRY SLOT WILL QUICKLY SWEEP ACROSS THE
FORECAST AREA DURING THE DAY. THERE MAY BE ENOUGH LINGERING LOW-
LEVEL MOISTURE ACROSS THE FAR EASTERN PANHANDLES DURING THE MORNING
FOR A CHANCE OF PRECIPITATION. KEPT THUNDERSTORMS IN THE
FORECAST...BUT FORECAST SOUNDINGS INDICATING LESS THAN 50 J/KG OF
MUCAPE. THANKS TO THE DRY SLOT...THE SUN WILL MAKE AN APPEARANCE
ACROSS THE REGION. HIGH TEMPERATURES SHOULD BE ABLE TO RISE INTO THE
50S AND POSSIBLY 60S AS STRONG DOWNSLOPING WINDS DEVELOP. SPEAKING OF
THE WINDS...EXPECT THEM TO STRENGTHEN BY LATE WEDNESDAY MORNING INTO
THE MID-AFTERNOON HOURS. FORECAST SOUNDINGS INDICATE MIXING HEIGHTS WILL
BE RELATIVELY SHALLOW AND WILL NOT BE ABLE TO TAP INTO THE HIGH
MOMENTUM MID-LEVEL AIR. NONETHELESS...FORECAST SOUNDINGS ARE SHOWING
30-35 KT FLOW AT THE TOP OF THE BOUNDARY LAYER. CONTINUED TO KEEP
WINDS BELOW ADVISORY CRITERIA...ESPECIALLY SINCE MET WINDS ARE
TRENDING LOWER. HOWEVER...IF THE GFS IS CORRECT...COULD SEE ADVISORY
LEVEL WINDS...ESPECIALLY ON THE CAPROCK. AS THE UPPER TROUGH AND
ATTENDANT SURFACE LOW MOVE INTO THE UPPER MISSISSIPPI VALLEY...A COLD
FRONT WILL PUSH SOUTHWARD ACROSS THE PANHANDLES WITH MUCH COOLER AND
DRIER AIR FILTERING INTO THE AREA. AS THE AFOREMENTIONED SYNOPTIC
FEATURES PULL AWAY FROM THE AREA...THE PRESSURE GRADIENT WILL ALSO
RELAX...ALLOWING WINDS TO QUICKLY SUBSIDE UNDER 10 MPH BY SUNRISE
THURSDAY.
THURSDAY-THURSDAY NIGHT: DRY AND SUB-SEASONAL TEMPERATURES ARE
EXPECTED AS NNE UPSLOPE WINDS PREVAIL THROUGH THE DAY. DUE TO THE
UPSLOPE WINDS...LOWERED HIGHS IN ALL AREAS. A CHILLY NIGHT IS
EXPECTED WITH LOWS IN THE 20S AND LOWER 30S.
FRIDAY-MONDAY: STILL A LOT OF UNCERTAINTIES DURING THIS TIME PERIOD.
THE DGEX AND GFS CONTINUE TO REMAIN FASTER WITH THE CUTOFF LOW THAN
THE ECMWF AND GGEM. JUST NOTICED THE NEW 06 UTC GFS HAS NOW TRENDED
SLOWER WITH THE CLOSED LOW AND IS MORE SIMILAR TO THE ECMWF AND
GGEM. EXPECT PRECIPITATION TO DEVELOP ACROSS THE SOUTHWEST TEXAS
PANHANDLE SATURDAY EVENING BEFORE SPREADING ACROSS ALL OF THE
FORECAST AREA SATURDAY NIGHT. RAIN IS LIKELY SATURDAY EVENING AND
THEN POSSIBLY MIXING WITH OR CHANGING TO SNOW SATURDAY NIGHT. SOME
INDICATIONS THAT LOW-LEVEL THERMAL PROFILES MAY BE A LITTLE WARM FOR
SNOW...BUT DUE TO THE UNCERTAINTY...KEPT A RAIN/SNOW MIX IN THE
FORECAST. BEYOND SUNDAY...CONSIDERABLE UNCERTAINTY EXISTS...BUT
FOLLOWED MORE CLOSELY TO THE ECMWF FOR NOW. IF IT DOES VERIFY...WE
COULD BE LOOKING AT MORE WINTER MISCHIEF BY EARLY NEXT WEEK. STILL
PLENTY OF TIME TO WATCH THIS SYSTEM SO STAY TUNED.
JACKSON
FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE EXPECTED TO REMAIN ABOVE 30 PERCENT
ACROSS ALL OF THE PANHANDLES FOR THE NEXT SEVEN DAYS. AS A
RESULT...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/03
AREA FORECAST DISCUSSION
NWS AMARILLO TX
443 AM CST MON DEC 12 2011
.DISCUSSION...
TODAY-TONIGHT: HAVE SEEN SOME PATCHY AREAS OF FOG ACROSS THE
PANHANDLES THIS MORNING...BUT STRONGER SURFACE WINDS HAVE PRECLUDED
ANY DENSE FOG CONCERNS. EXPECT PATCHY FOG TO CONTINUE THROUGH MOST
OF THE MORNING HOURS SOUTH AND EAST OF A LINE FROM DALHART TO GUYMON.
MUCH LOWER VISIBILITIES HAVE BEEN NOTED ACROSS THE SOUTH PLAINS WHERE
SURFACE/LOW-LEVEL WINDS HAVE WEAKENED...PER KLBB VAD DATA. RUC DATA
INDICATES WINDS ACROSS THE PANHANDLES MAY ALSO WEAKEN...AND IF THIS
OCCURS...VISIBILITIES WILL LIKELY DETERIORATE. STILL NOT EXPECTING
ANY DENSE FOG ISSUES AS SURFACE WINDS SHOULD REMAIN ABOVE 10
MPH...BUT WILL MONITOR CLOSELY. WOULDN/T BE SURPRISED TO SEE SOME
DRIZZLE ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE THROUGH 9 AM WHERE
FORECAST SOUNDINGS INDICATE THE LOW-LEVEL MOISTURE WILL REMAIN
AROUND 2000 FT DEEP...BUT SINCE THIS IS ON THE MARGINAL END FOR
DRIZZLE...LEFT OUT OF THE FORECAST FOR NOW. OTHERWISE...EXPECT MOST
OF THE AREA TO REMAIN GRUNGED IN WITH LOW CLOUDS FOR MOST OF THE DAY.
AS A RESULT...HIGH TEMPERATURES WILL CONTINUE TO REMAIN BELOW
SEASONAL NORMS. IT IS INTERESTING TO NOTE THAT THE AVERAGE DAILY
TEMPERATURE AT AMARILLO...BORGER...DALHART...AND GUYMON HAS NOT BEEN
ABOVE NORMAL SINCE NOVEMBER 30. AS ISENTROPIC ASCENT INCREASES THIS
EVENING AND OVERNIGHT...PRECIPITATION CHANCES WILL ALSO INCREASE. QPF
AMOUNTS WILL BE LIGHT WITH MOST LOCATIONS SEEING LESS THAN 0.10"
THROUGH SUNRISE ON TUESDAY. EXPECTING THE PRECIPITATION TYPE TO BE
ALL LIQUID AS WARM AIR ADVECTION...MOISTURE ADVECTION...AND LOW
CLOUDS SHOULD KEEP TEMPERATURES ABOVE FREEZING. ONCE AGAIN...ANOTHER
ROUND OF PATCHY FOG IS EXPECTED DEVELOP AREAWIDE...BUT THE RAIN SHOULD
KEEP THE NEAR GROUND AIR MIXED ENOUGH TO LIMIT ANY DENSE FOG
CONCERNS.
TUESDAY-TUESDAY NIGHT: PATCHY FOG MAY LINGER INTO THE LATE MORNING
HOURS ON TUESDAY. OTHERWISE...ANOTHER DREARY DAY IS EXPECTED WITH LOW
CLOUDS AND INCREASING PRECIPITATION CHANCES...ESPECIALLY AFTER NOON.
MAX TEMPS WILL ONCE AGAIN BE ON THE COOL SIDE. MET AND MAV GUIDANCE
APPEAR TOO HIGH...SO FOLLOWED RAW NAM TEMPERATURES CLOSELY. BY
TUESDAY AFTERNOON...FORECAST SOUNDINGS INDICATE SOME WEAK ELEVATED
INSTABILITY DEVELOPING ACROSS MOST OF THE PANHANDLES AS LOW-LEVEL
MOISTURE INCREASES AND MID-LEVEL LAPSE RATES STEEPEN. KEPT
THUNDERSTORMS IN THE FORECAST AND SHIFTED THEM SLIGHTLY WESTWARD.
STRONGER MOISTURE ADVECTION IS EXPECTED ACROSS MOST OF THE AREA ON
TUESDAY NIGHT....AND IN FACT...THE ECMWF...GGEM...AND GFS ALL SHOW
SURFACE DEW POINTS IN THE MID TO UPPER 50S ACROSS THE SOUTHEAST TEXAS
PANHANDLE! IT/S AMAZING TO REALIZE THAT WE STRUGGLED TO SEE DEW
POINTS THAT HIGH DURING THE SPRING AND SUMMER...BUT IT/S POSSIBLE
THEY MAY REACH THAT HIGH IN DECEMBER. REGARDLESS...AS FORCING FOR
ASCENT IMPINGES ON THE MOIST AND WEAKLY UNSTABLE AIR
MASS...PRECIPITATION AND THUNDERSTORM CHANCES WILL REALLY RAMP UP
TUESDAY EVENING AND NIGHT. WITHIN THE LAST COUPLE OF WEEKS...HAVE
NOTICED THAT THE SUBTROPICAL JET HAS HAD A CONNECTION TO THE
TROPICS...AND THIS LOOKS TO BE THE CASE AGAIN WITH THIS SYSTEM. AS A
RESULT...WON/T BE SURPRISED TO SEE RAINFALL AMOUNTS OVERACHIEVE IN
SOME LOCATIONS. REGARDING THUNDERSTORM POTENTIAL...FORECAST
SOUNDINGS ARE SHOWING UP TO 300 J/KG OF MUCAPE ALONG WITH DEEP LAYER
SHEAR AROUND 70 KT. AS A RESULT...MAY SEE A FEW STRONG STORMS PRODUCE
SMALL HAIL TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. NOT EXPECTING ANY
WINTRY PRECIPITATION AS SURFACE AND LOW-LEVEL TEMPERATURES WILL
REMAIN ABOVE FREEZING.
WEDNESDAY-WEDNESDAY NIGHT: THE DRY SLOT WILL QUICKLY SWEEP ACROSS THE
FORECAST AREA DURING THE DAY. THERE MAY BE ENOUGH LINGERING LOW-
LEVEL MOISTURE ACROSS THE FAR EASTERN PANHANDLES DURING THE MORNING
FOR A CHANCE OF PRECIPITATION. KEPT THUNDERSTORMS IN THE
FORECAST...BUT FORECAST SOUNDINGS INDICATING LESS THAN 50 J/KG OF
MUCAPE. THANKS TO THE DRY SLOT...THE SUN WILL MAKE AN APPEARANCE
ACROSS THE REGION. HIGH TEMPERATURES SHOULD BE ABLE TO RISE INTO THE
50S AND POSSIBLY 60S AS STRONG DOWNSLOPING WINDS DEVELOP. SPEAKING OF
THE WINDS...EXPECT THEM TO STRENGTHEN BY LATE WEDNESDAY MORNING INTO
THE MID-AFTERNOON HOURS. FORECAST SOUNDINGS INDICATE MIXING HEIGHTS WILL
BE RELATIVELY SHALLOW AND WILL NOT BE ABLE TO TAP INTO THE HIGH
MOMENTUM MID-LEVEL AIR. NONETHELESS...FORECAST SOUNDINGS ARE SHOWING
30-35 KT FLOW AT THE TOP OF THE BOUNDARY LAYER. CONTINUED TO KEEP
WINDS BELOW ADVISORY CRITERIA...ESPECIALLY SINCE MET WINDS ARE
TRENDING LOWER. HOWEVER...IF THE GFS IS CORRECT...COULD SEE ADVISORY
LEVEL WINDS...ESPECIALLY ON THE CAPROCK. AS THE UPPER TROUGH AND
ATTENDANT SURFACE LOW MOVE INTO THE UPPER MISSISSIPPI VALLEY...A COLD
FRONT WILL PUSH SOUTHWARD ACROSS THE PANHANDLES WITH MUCH COOLER AND
DRIER AIR FILTERING INTO THE AREA. AS THE AFOREMENTIONED SYNOPTIC
FEATURES PULL AWAY FROM THE AREA...THE PRESSURE GRADIENT WILL ALSO
RELAX...ALLOWING WINDS TO QUICKLY SUBSIDE UNDER 10 MPH BY SUNRISE
THURSDAY.
THURSDAY-THURSDAY NIGHT: DRY AND SUB-SEASONAL TEMPERATURES ARE
EXPECTED AS NNE UPSLOPE WINDS PREVAIL THROUGH THE DAY. DUE TO THE
UPSLOPE WINDS...LOWERED HIGHS IN ALL AREAS. A CHILLY NIGHT IS
EXPECTED WITH LOWS IN THE 20S AND LOWER 30S.
FRIDAY-MONDAY: STILL A LOT OF UNCERTAINTIES DURING THIS TIME PERIOD.
THE DGEX AND GFS CONTINUE TO REMAIN FASTER WITH THE CUTOFF LOW THAN
THE ECMWF AND GGEM. JUST NOTICED THE NEW 06 UTC GFS HAS NOW TRENDED
SLOWER WITH THE CLOSED LOW AND IS MORE SIMILAR TO THE ECMWF AND
GGEM. EXPECT PRECIPITATION TO DEVELOP ACROSS THE SOUTHWEST TEXAS
PANHANDLE SATURDAY EVENING BEFORE SPREADING ACROSS ALL OF THE
FORECAST AREA SATURDAY NIGHT. RAIN IS LIKELY SATURDAY EVENING AND
THEN POSSIBLY MIXING WITH OR CHANGING TO SNOW SATURDAY NIGHT. SOME
INDICATIONS THAT LOW-LEVEL THERMAL PROFILES MAY BE A LITTLE WARM FOR
SNOW...BUT DUE TO THE UNCERTAINTY...KEPT A RAIN/SNOW MIX IN THE
FORECAST. BEYOND SUNDAY...CONSIDERABLE UNCERTAINTY EXISTS...BUT
FOLLOWED MORE CLOSELY TO THE ECMWF FOR NOW. IF IT DOES VERIFY...WE
COULD BE LOOKING AT MORE WINTER MISCHIEF BY EARLY NEXT WEEK. STILL
PLENTY OF TIME TO WATCH THIS SYSTEM SO STAY TUNED.
JACKSON
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE EXPECTED TO REMAIN ABOVE 30 PERCENT
ACROSS ALL OF THE PANHANDLES FOR THE NEXT SEVEN DAYS. AS A
RESULT...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 48 40 49 43 58 / 5 30 50 50 5
BEAVER OK 50 39 49 45 55 / 5 30 50 60 20
BOISE CITY OK 44 36 45 36 51 / 5 20 50 50 10
BORGER TX 50 42 48 45 58 / 5 30 50 60 10
BOYS RANCH TX 50 40 49 43 57 / 5 30 50 50 5
CANYON TX 48 41 49 43 60 / 5 30 50 50 5
CLARENDON TX 50 41 50 48 61 / 10 30 50 60 20
DALHART TX 49 36 49 35 54 / 5 30 50 50 5
GUYMON OK 48 36 48 41 55 / 5 20 50 60 10
HEREFORD TX 48 42 49 43 58 / 5 30 50 50 5
LIPSCOMB TX 50 41 49 47 57 / 5 30 50 60 20
PAMPA TX 48 41 48 45 57 / 5 30 50 60 20
SHAMROCK TX 51 40 50 49 63 / 10 30 50 60 20
WELLINGTON TX 51 41 52 49 65 / 10 30 50 60 20
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
17/13
AREA FORECAST DISCUSSION
NWS SPOKANE WA
230 PM PST Mon Dec 12 2011
.SYNOPSIS...High pressure will be over the Inland Northwest for
through Wednesday. Expect more fog/stratus formation tonight. A
stronger and more organized Pacific storm system will arrive
Wednesday evening and Thursday with the possibility of more
substantial snow accumulations over a large area. Dry and benign
conditions will return for the beginning of the weekend.
&&
.DISCUSSION...
Tonight through Wednesday: More fog and stratus to deal with. With the
departure of the low pressure trough, high pressure has been
sinking into the region from the north and funneling down the
north/south valleys especially the Okanogan valley. This process
has helped erode and keep back the stratus that has been banked up
across the southern section of the forecast area. This area has a
well defined line - stretching from Othello to Harrington to just
south of Spokane and Coeur d`Alene to the Silver Valley. This
evening the northerly pressure gradient will weaken as high
pressure settles over the region. This will shut off the winds and
allow the area of stratus and fog to expand northward. This is
seen well by the NAM, RUC and the HRR encompassing the Spokane/
Coeur d`Alene area and the Moses Lake/Ephrata area and heading to
the northern valleys overnight and into Tuesday morning. Mixing
and winds will be weak on Tuesday giving way to little break up
the low level cloud deck. This will make temperatures tricky
depending on how clear some areas will be and for how long.
Anticipate diurnal temperature change from Lewiston to Pullman and
Ritzville. The coolest spots will be in the sheltered northern
valleys like the Methow and near Priest Lake. For Tuesday and
Tuesday night, a weak weather disturbance will ride over the upper
level ridge and spread mid and high level clouds across the Inland
Northwest. Dynamics look weak with a dry air above the boundary
layer, giving way to a slight chance of snow for the higher
elevations into the north and the Idaho Panhandle. This may
disrupt the stratus deck temporarily, but high pressure will
return again on Wednesday for more stable and dry conditions. The
air stagnation advisory will remain in effect for the region.
/rfox.
Wednesday night and Thursday...A dramatic change to the stagnant
and benign weather conditions of late will occur on Wednesday
night and Thursday. Just about all of the available model guidance
brings a noticeably stronger system through the region than the
recent feeble impulses. The ECMWF model has been most consistent
with the character of this incoming storm over the past few
days...although the GFS/Canadian/UKMET and SREF guidance have also
tenuously climbed aboard in the last 24 hours.
At this time it appears a rather vigorous and fast moving short
wave will drop through the region from northwest to southeast. the
cyclonic diffluent base dynamic region will sweep through the
northern zones and sustain a steady strength or slightly weakening
surface low pressure tracking just north of the Canadian border
and dropping into Montana by late Thursday. The close approach of
this low will drag a warm front/cold front couplet through the
northern and eastern zones late Wednesday night and Thursday
morning. For a six to 9 hour period or so a moderate Pacific
moisture feed will fuel precipitation along this frontal couplet.
Air mass characteristics will support snow in just about all
locations overnight and Thursday morning...but snow-water ratios
will likely be rather low in the lowest elevations at Lewiston and
Wenatchee. Thus...confidence is increasing for a widespread snow
event Wednesday night and Thursday. The northerly track of the
offending surface low and the relatively fast transit of the
heaviest lift region argues strongly that this will be a
significant...but generally sub-warning criteria event...perhaps
2-4 inches in the higher plateaus of the Columbia Basin and
valleys north and west of the basin. The best chance of truly
heavy snow will probably be near the Canadian border over
Northeast Washington and North Idaho closer to the actual surface
low track...and in the Panhandle Mountains where post frontal
orographic ascent will augment synoptic accumulation potential. It
is too early to pin down this potential as of yet. In any
event...Thursday morning`s commute will probably be dicey over
much of Eastern Washington and North Idaho.
This system will likely provide some relief to the recent run of
stagnant air quality...and the next conference call with air
quality officials will occur Thursday morning and the disposition
of the current Air Stagnation Advisory will be further evaluated
based on how this system manifest itself.
By late Thursday this storm is moving out of the region with
lingering snow showers in the Panhandle Mountains and probably the
Camas Prairie...While a new shot of dry continental air will push
down the Okanogan Valley and begin a new low level air mass
exchange in the Columbia Basin.
Thursday night through Saturday...Reasonable model agreement
continues this period featuring a new upper level ridge forming
over the northwest. This will lead to generally dry and quiet
conditions with a possible return to increasingly stagnant
inversion conditions once again. Where models do differ...it is
with the strength of this ridge and the potential for weak
impulses to trigger a few mountain snow showers across the north
and maybe a stray flurry in some valley locations. Otherwise it
looks like an essentially dry and cool period...but with a better
potential for overnight and early morning fog since fresh snow
cover will provide a better moisture source and enhance
overnight radiational cooling potential better than the recent
stretch of quiet weather. /Fugazzi
For Saturday night through Monday...The EC brings a quick hitting
system across the Inland Northwest Saturday night in deep
northwesterly flow. This would likely only result in light
mountain snow before the model develops the ridge of high pressure
back over the Pacific Northwest. The GFS meanwhile brings a weak
stretching system across the Inland Northwest Sunday dampening the
ridge, which allows the jet stream to shift overhead, and
subsequently allow a series of storm systems to move into the
region early next week...more typical of December. However, given
the pattern of late, I trended pops below climo and more in line
with the EC. /Neuman
&&
.AVIATION...
18Z TAFs...High pressure will continue to build into the region.
Northerly flow resulted in an erosion of fog and low clouds from
KEAT and KGEG/KSFF. But IFR/MVFR cigs and vsbys will plague KCOE,
KPUW, KLWS and KMWH through 21z with slight improvements through
00z. Surface pressure gradients and winds will become very light and
combined with high pressure, and clearing of mid and high level
clouds will lead to more widespread fog and stratus formation
especially after 6z and persisting through 18z Tuesday at most of
the TAF locations. /rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 18 29 21 32 25 33 / 0 10 10 0 60 60
Coeur d`Alene 18 30 22 33 26 33 / 0 10 10 10 70 60
Pullman 23 33 23 36 27 35 / 0 10 10 10 50 60
Lewiston 22 35 25 38 29 40 / 0 10 10 10 30 50
Colville 20 30 20 32 22 34 / 0 10 10 10 70 60
Sandpoint 18 28 22 31 24 33 / 0 10 20 10 70 70
Kellogg 20 29 22 32 25 31 / 0 10 20 20 60 70
Moses Lake 16 30 15 33 21 36 / 0 10 0 10 40 20
Wenatchee 19 29 23 32 26 36 / 0 10 0 10 60 20
Omak 13 30 18 32 21 36 / 0 10 0 10 70 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Thursday for Central
Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
Lewiston Area-Northern Panhandle.
WA...Air Stagnation Advisory until Noon PST Thursday for East Slopes
Northern Cascades-Lower Garfield and Asotin Counties-Moses
Lake Area-Northeast Mountains-Okanogan Highlands-Okanogan
Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-
Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
943 PM CST TUE DEC 13 2011
.UPDATE...
MAIN PROBLEM IS SMALL POSSIBILITY OF RAIN/SNOW MIX ACROSS MAINLY
PORTIONS OF MARQUETTE COUNTY. FORECAST SOUNDINGS INDICATE THAT BY
THE TIME THE PRECIPITATION ARRIVES IT SHOULD BE MAINLY RAIN.
PRECIPITATION BEGAN AS RAIN OVER THE DELLS. EVAPORATIVE COOLING
WILL MAKE IT A CLOSE CALL.
&&
.AVIATION/06Z TAFS/...
EXPECT PRECIPITATION TO SPREAD NORTH AND EAST DURING THE EARLY
MORNING HOURS WITH CIGS/VSBYS EVENTUALLY LOWERING TO IFR/LIFR.
MAIN SURFACE LOW RILL MOVE ACROSS SOUTHWEST TO NORTHEAST WISCONSIN
WEDNESDAY NIGHT...WITH FAR SOUTH CENTRAL AND PORTIONS OF SOUTHEAST
WISCONSIN GETTING INTO THE MILDER AIR BRIEFLY. THIS SHOULD CAUSE
CIGS/VSBYS TO IMPROVE. MINIMAL ELEVATED CAPE COULD BRING SOME
EMBEDDED THUNDERSTORMS MAINLY WEDNESDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 327 PM CST TUE DEC 13 2011/
VERY SHORT TERM...
TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWED A DEEP TROUGH OVER THE
WESTERN U.S...WITH A LARGE PLUME OF MOISTURE STRETCHING FROM TEXAS
THROUGH NORTHERN MISSOURI. SHORTWAVE EJECTING OUT OF THE SW UPPER
LOW WILL BRING A SFC LOW FROM THE PLAINS THROUGH IOWA ON WED. FIRST
ROUND OF PRECIPITATION WILL BEGIN ALREADY TONIGHT ON THE NOSE OF THE
LOW LEVEL JET AND AN INITIAL WEAK SHORTWAVE OUT AHEAD OF THE MAIN
TROUGH. STRONG ISENTROPIC LIFT ALONG THIS SURGE OF WARM AND MOIST
AIR WILL ALLOW FOR MODERATE RAIN OVERNIGHT THROUGH EARLY WED
MORNING.
MODELS SLOWED DOWN THE ONSET OF THE PRECIP...SO BACKED OFF POPS A
BIT IN THE 03Z-06Z TIME RANGE. PRECIP FOR THE FIRST ROUND COULD
APPROACH A QUARTER INCH.
A LULL IN THE STEADY PRECIP IS EXPECTED DURING THE MORNING HOURS ON
WED. THE INITIAL WAA AND ISENTROPIC LIFT WILL BE TO THE NORTH OF THE
FORECAST AREA...AND THE WARM FRONTAL PRECIP WILL STILL BE SOUTH OF
THE WI/IL BORDER. DURING THIS LULL...THERE MAY BE SOME AREAS OF FOG
AND MUCH LOWER CLOUDS.
THEN THE SECOND ROUND OF PRECIP WILL COME IN EITHER LATE MORNING OR
EARLY AFTERNOON ON WED...TIMING STILL UNCERTAIN. STRONG DYNAMICS
WITH THIS SURGE OF MOISTURE...SINCE THE 500MB TROUGH AND SFC LOW
WILL BE APPROACHING...ALONG WITH THE SFC AND 850MB WARM FRONT. WITH
THE STRONG FORCING...ISOLATED THUNDER NOT OUT OF THE QUESTION. KEPT
THE SCHC THUNDER MENTION IN THE AFTERNOON. UP TO A HALF INCH OF RAIN
POSSIBLE WITH THIS SECOND ROUND. TEMPS EXPECTED TO RISE INTO THE
MID/UPPER 40S WITH THE FRONT LATE WED AFTERNOON.
SHORT TERM...WEDNESDAY NIGHT THROUGH FRIDAY.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM TO
HIGH.
SOUTHERLY FLOW AHEAD OF THE SURFACE LOW BRINGS THERMAL RIDGE INTO
THE SOUTHEAST THAT WILL ALLOW TEMPERATURES TO CLIMB TO THE LOW 50S.
MAIN AREA OF PRECIPITATION WILL END FROM WEST TO EAST AFTER 06Z
THURSDAY WITH SUBSIDENCE BEHIND 500 MB AND SURFACE TROUGHS.
OMEGA AHEAD OF SECOND NORTHERN STREAM SHORT WAVE MAINLY FOCUSED TO
THE NORTH WITH THE STRONGEST 700-500MB FRONTOGENETIC RESPONSE DURING
THE DAY THURSDAY. COLDER AIR HOLDS OFF UNTIL PASSAGE OF THIS SECOND
WAVE...SO EXPECT ANY LINGERING PRECIPITATION THURSDAY TO BE VERY
LIGHT RAIN OR DRIZZLE...WITH DRYING IN THE DENDRITE GROWTH ZONE
PREVENTING CRYSTAL FORMATION AND SNOW. EARLY DAYTIME HIGH
TEMPERATURES AROUND 12-13Z THURSDAY THEN COOLING THROUGH THE DAY.
ANY LIGHT PRECIPITATION SHOULD END BY 18Z.
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
SURFACE HIGH PRESSURE BUILDS OVER FOR THURSDAY NIGHT AND FRIDAY.
CLEARING SKIES THURSDAY NIGHT...BUT WINDS WILL TAKE A BIT LONGER TO
LIGHTEN/DECOUPLE OVERNIGHT. LOWS AROUND 20 NORTHWEST...TO MID 20S
ALONG THE LAKE. -5C TO -6C 925 MB TEMPERATURES SUPPORT LOW TO MID 30
HIGHS FRIDAY.
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY. FORECAST CONFIDENCE LOW
TO MEDIUM.
NORTHWEST TO SOUTHEAST MOVING SHORT WAVE CROSSES REGION FRIDAY
NIGHT/SATURDAY...BUT DRY LOWER LAYERS WILL PREVENT
MEASURABLE...THOUGH A FEW FLURRIES ARE POSSIBLE. WILL LEAVE ANY
PRECIPITATION MENTION OUT FOR NOW. DRY NORTHWEST FLOW WITH NORMAL
TEMPERATURES SATURDAY...BEGINS TO BACK WEST SUNDAY AND THEN
SOUTHWEST MONDAY AS NEXT SYSTEM EJECTS OUT OF THE SOUTHWEST U.S.
INTO THE CENTRAL PLAINS. WHILE MODELS DIFFER ON EXACTING
DETAILS...EARLY TREND IS TO TAKE SURFACE LOW ACROSS ILLINOIS AND
INDIANA MONDAY NIGHT/TUESDAY...WITH SOUTHERN WISCONSIN ON THE
NORTHERN EDGE OF THE PRECIPITATION SHIELD. WARMTH PUSHING BACK NORTH
AHEAD OF LOW WILL BRING A MAINLY RAIN/SNOW MIX...CHANGING TO ALL
SNOW AFTER LOW PASSAGE. WILL HAVE TO WATCH FOR ACCUMULATING SNOW
POTENTIAL IF PROFILE TEMPERATURES COO MORE THAN CURRENTLY
INDICATED.
AVIATION/00Z TAFS/...VFR CIGS WILL SLOWLY LOWER AS SOUTH WINDS
SLOWLY INCREASE LOW LEVEL MOISTURE THIS EVENING. SLOWED THE TIMING
OF THIS LOWERING TO EARLY EVENING. MVFR CIGS WILL DEVELOP FROM WEST
TO EAST ACROSS THE CWA DURING THE AFTERNOON INTO THE EARLY EVENING.
RAIN VIA WARM...MOIST ADVECTION WILL THEN ARRIVE AT THE TAF SITES BY
AROUND MIDNIGHT AND CONTINUE INTO WED. CIGS WILL FALL TO LIFR WITH
THE RAIN AND SATURATION OF THE LOW LEVEL ATMOSPHERE WHILE VSBYS WILL
FALL TO IFR.
THERE SHOULD BE A PERIOD OF TIME WED MORNING WHERE THERE IS A LULL
IN THE STEADY RAIN...WHICH WOULD ACTUALLY DIMINISH VISIBILITY AND
LOWER THE CEILING HEIGHTS. NOT SURE OF EXACT TIMING OF THIS
LULL...THEN RAIN WILL INCREASE ONCE AGAIN EARLY WED AFTERNOON AS THE
MAIN UPPER AND SFC LOW APPROACH SOUTHERN WI. THE SECOND ROUND OF
RAIN IS EXPECTED TO BE HEAVIER THAN THE FIRST...AND THE STRONG
FORCING SHOULD ALLOW FOR SOME ISOLATED THUNDER.
MARINE...INCREASING SOUTHERLY WINDS WILL ALLOW FOR BUILDING WAVES
TO NEAR-SMALL CRAFT ADVISORY CRITERIA WED AFTERNOON. WAVE MODEL FCST
WAVE HEIGHTS UP TO 3 TO 4 FEET...SO HELD OFF ON ISSUING A SMALL CRAFT
ADVY. WEST WINDS BEHIND THE DEPARTING LOW ON THU WILL INCREASE...AND
WIND GUSTS TO 25 KNOTS ARE POSSIBLY/LIKELY WITH THE COLD AIR
ADVECTION. SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/WEDNESDAY AND AVIATION/MARINE...MRC
WEDNESDAY NIGHT THROUGH TUESDAY...REM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CST TUE DEC 13 2011
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
233 PM CST TUE DEC 13 2011
ACTIVE WEATHER NEXT 48 HOURS LOOKS TO HAVE MINIMAL IMPACT. FOCUS
REMAINS CENTERED ON DETAILS OF PRECIPITATION LATER TONIGHT AND INTO
WEDNESDAY NIGHT.
SHORT WAVE ENERGY ROTATING OUT OF LARGE SOUTHWEST U.S. PV-ANOMALY
WILL DRAMATICALLY INCREASE DYNAMICS STARTING THIS EVENING WITH
STRONG LIFT...LARGE LOW LEVEL MOISTURE PUSH AND EXPECTED INCREASE IN
PRECIPITATION COVERAGE. LAYER PRECIPITABLE WATER VALUES EXCEED 300
PERCENT AHEAD OF THIS WAVE WITH PROGGED 850 MB DEW POINT
TEMPERATURES CLOSE TO 10 C MOVING NORTHWARD. SURFACE TEMPERATURES
STARTING OFF RELATIVELY MILD /ALL ABOVE FREEZING/ AS LOW LEVEL WARM
AIR ADVECTION EXPECTED TO INCREASE THIS EVENING. THIS SHOULD KEEP
BULK OF PRECIPITATION AT ONSET TONIGHT AS JUST RAIN BUT STILL SOME
CONCERN ALONG AND NORTHEAST OF INTERSTATE 94 WHERE SOME COOLING
COULD ALLOW MIX BEFORE EVERYONE CHANGES TO RAIN EARLY TOMORROW
MORNING. MODEL SOUNDINGS SUGGEST VERY CLOSE CALL ON RAIN/SNOW MIX
BUT EVEN SHORT RANGE ENSEMBLE PLUMES POINTING TOWARDS MAINLY RAIN.
AS BULK OF SHORT WAVE ENERGY EJECTS ON WEDNESDAY SHOULD BE RAIN
AROUND FOR MOST OF WEDNESDAY. BEST LOW LEVEL WARM AIR AND MOISTURE
ADVECTION APPEARS TO REMAIN JUST SOUTH AND EAST OF FORECAST AREA BUT
COULD NOT RULE OUT SOME THUNDER WITH ISOLATED CONVECTION PER
PREVIOUS FORECAST AND STORM PREDICTION CENTER DAY 2 OUTLOOK. HIGHEST
RISK FOR ANY THUNDER FROM EASTERN IOWA INTO SOUTHERN WISCONSIN.
LEADING SHORT WAVE ENERGY SHOULD MOVE EAST FAIRLY QUICKLY WEDNESDAY
NIGHT SO UNSURE HOW EXTENSIVE PRECIPITATION WILL BE BEHIND THIS. AS
COOLER AIR BEGINS TO WRAP IN SO DOES SOME DRYING. EVEN THOUGH COLUMN
TEMPERATURES COOL ENOUGH FOR TRANSITION OVER TO SNOW...ICE VANISHES
FROM CLOUD LAYER JUST ABOUT AS FAST. HAD INITIALLY THOUGHT ABOUT
CHANCE FOR SOME FREEZING DRIZZLE AS COLDER AIR SETTLES IN BUT LACK
OF LIFT SHOULD PREVENT THAT. MOST LIKELY SCENARIO IS ABRUPT END TO
RAIN AND FALLING TEMPERATURES...ESPECIALLY AFTER A MILD WEDNESDAY
EVENING AHEAD OF FRONT.
SHORT WAVE TROUGH PROGGED BY MOST GUIDANCE IN NORTHWEST BRANCH OF
SPLIT UPPER FLOW TO FOLLOW ON THE HEELS OF THIS SYSTEM BRINGING
STRONG COLD AIR ADVECTION FOR THURSDAY. PRESSURE GRADIENT SUGGESTS
LOW END WIND EVENT BUT NOT SURE SPEEDS WILL HIT ADVISORY CRITERIA.
ONE CHANGE IN FORECASTS INCLUDES INCREASE IN CLOUDS AS WRAP AROUND
STRATUS FIELD COULD FORM IN COLD AIR ADVECTION AND LAST INTO FRIDAY.
AT THIS POINT WILL REMAIN OPTIMISTIC THAT CLOUDS WILL CLEAR WITH
DRYING THURSDAY NIGHT BUT THIS WILL HAVE TO BE MONITORED ALONG WITH
WIND SPEEDS. FALLING TEMPERATURES THURSDAY EXPECTED IN WHAT APPEARS
TO BE A RAW...WINDY LATE FALL DAY BEFORE THINGS RELAX ON FRIDAY.
.LONG TERM...SATURDAY THROUGH TUESDAY
233 PM CST TUE DEC 13 2011
SPLIT FLOW REGIME CONTINUES IN MEDIUM RANGE WITH WEEKEND STARTING
OFF ON COOLER SIDE. SOME HINTS OF WEAK SHORT WAVE ENERGY OR UPPER
SHEAR AXIS IN NORTHWEST FLOW STRETCHING FROM SOUTHERN CANADA INTO
THE GREAT LAKES BUT FAIRLY DRY REGIME SHOULD KEEP THINGS QUIET.
MAIN FOCUS IN THIS RANGE IS SIGNAL OF SOUTHWEST SYSTEM EJECTING INTO
THE CENTRAL U.S. EARLY NEXT WEEK. ECMWF HAS BEEN MORE CONSISTENT
KEEPING THIS SYSTEM JUST SOUTH OF THE AREA WHILE GFS RUNS HAVE BEEN
BACK AND FORTH. 13.12Z GFS MORE IN LINE WITH ECMWF WITH FURTHER
SOUTH SOLUTION BUT WILL KEEP SMALL POPS GOING FOR DAY 6 /MON/ FOR
CONSISTENCY AND COLLABORATION PURPOSES. STILL TOO EARLY FOR DETAILS
WITH ANY POTENTIAL IMPACT. WITH BARE GROUND ANTICIPATED WILL
INTRODUCE MIX OF RAIN AND SNOW WITH HIGHS IN THE 30S KEEPING CHANCES
OF A BROWN CHRISTMAS HIGHER THAN NORMAL THIS YEAR.
&&
.AVIATION...TONIGHT AND WEDNESDAY
609 PM CST TUE DEC 13 2011
FORECAST CONCERNS THIS TAF PERIOD ARE PRECIPITATION TIMING AND
CEILINGS/VISIBILITIES AT BOTH KRST AND KLSE. DEVELOPING SURFACE LOW
ACROSS CENTRAL PLAINS WILL CONTINUE TO LIFT NORTHEAST TOWARDS THE
AREA. AS OF 00Z...VFR CONDITIONS WERE ACROSS SOUTHEAST MINNESOTA
AND WEST CENTRAL WISCONSIN. MVFR CONDITIONS WITH LIGHT RAIN /
DRIZZLE ACROSS NORTHWEST IOWA AND SOUTHWEST MINNESOTA WILL SPREAD
EAST LATER THIS EVENING. COMPARED TO OBSERVATIONS...BOTH RUC AND
NAM MODEL FORECASTS ARE SEVERAL HOURS DELAYED IN PRECIPITATION
TIMING...SO BROUGHT IN RAIN EARLIER...03Z AT KRST AND 05Z AT KLSE.
INCREASING MOISTURE AND SATURATION OVERNIGHT WILL ALLOW CEILINGS
AND VISIBILITIES DROP TO IFR...TO AROUND 600 FT AT KRST AND 900 FT
AT KLSE. LIGHTER WINDS ON WEDNESDAY MAY ALLOW LIFR CONDITIONS TO
DEVELOP...ESPECIALLY AT KRST...WHERE CEILINGS AS LOW AS 300 FT ARE
POSSIBLE. AT KLSE...KEPT A 500 FT DECK THROUGH THE DAY.
PRECIPITATION FOR MUCH OF THE DAY WILL LEAD TO IFR CONDITIONS
THROUGH WEDNESDAY EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
233 PM CST TUE DEC 13 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...SHEA
LONG TERM....SHEA
AVIATION...ZT/HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
534 AM CST MON DEC 12 2011
.SHORT TERM...TODAY THROUGH WEDNESDAY
331 AM CST MON DEC 12 2011
FORECAST CONCERNS ARE ON DRIZZLE/FREEZING DRIZZLE THIS MORNING AND
AGAIN TONIGHT AND THE POTENTIAL FOR AREAS OF FOG LATE TONIGHT INTO
TUESDAY MORNING. FOCUS THEN TURNS TO STORM SYSTEM EXPECTED TO
IMPACT THE AREA TUESDAY NIGHT INTO WEDNESDAY...WITH PRECIPITATION
TYPE CONCERNS.
CURRENT RADAR AND SURFACE OBSERVATIONS SHOWED DRIZZLE FALLING
ACROSS MUCH OF THE FORECAST AREA. AREAS OF FREEZING DRIZZLE HAVE
BEEN REPORTED ACROSS NORTH CENTRAL WISCONSIN THROUGH SOUTHWEST
WISCONSIN...WITH SOME SECONDARY ROADWAYS VERY SLICK.
DRIZZLE WILL CONTINUE ACROSS THE AREA THIS MORNING AS LOW LEVEL
MOISTURE CONTINUES TO STREAM INTO THE REGION FROM THE SOUTHERN
PLAINS. ISENTROPIC LIFT ON THE 280-300K SURFACE ALONG WITH A WEAK
SHORTWAVE TROUGH MOVING ACROSS THE REGION...WILL ACT TO PRODUCE
DRIZZLE ACROSS MUCH OF THE FORECAST AREA THROUGH THIS AFTERNOON.
SURFACE TEMPERATURES HAVE WARMED ABOVE FREEZING ACROSS MUCH OF THE
FORECAST AREA EARLY THIS MORNING. HOWEVER...SOME SECONDARY ROADWAYS
AND SHADED LOCATIONS WILL LIKELY HAVE SURFACE TEMPERATURES AROUND
FREEZING AND SHOULD EXPERIENCE SOME LIGHT ICING. WILL CONTINUE THE
FREEZING DRIZZLE ADVISORY THROUGH 9 AM FOR THIS LIGHT ICING
POTENTIAL. DRIZZLE AND CLOUDY SKIES CAN BE EXPECTED INTO THIS
EVENING...WITH THE DRIZZLE GRADUALLY TAPERING OFF DURING THE LATE
EVENING INTO THE OVERNIGHT HOURS. SOME PATCHY FREEZING DRIZZLE CAN
BE EXPECTED ACROSS WESTERN AND CENTRAL WISCONSIN...WHERE A FEW
LOCATIONS WILL DROP TO FREEZING. AT THIS TIME IT APPEARS ICING WILL
BE MINIMAL BUT WILL HAVE TO CLOSELY MONITOR TEMPERATURES THROUGH THE
DAY TODAY. IF TEMPERATURES COOL FURTHER THAN WHAT IS CURRENTLY
ANTICIPATED...A FREEZING RAIN ADVISORY MAY BE NEEDED THIS EVENING
INTO TONIGHT...ESPECIALLY ALONG AND NORTH OF THE I-94 CORRIDOR. LOOK
FOR LOW TEMPERATURES TO FALL INTO THE LOWER 30S TONIGHT UNDER CLOUDY
SKIES.
LOW LEVEL MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA ON TUESDAY
WITH WEAK RIDGING ALOFT MOVING OVERHEAD. WITH LIGHT AND VARIABLE
WINDS ACROSS THE REGION AND ANY REMAINING SNOW MELTING...AREAS OF
FOG MAY DEVELOP AND COULD POTENTIALLY BE DENSE EARLY TUESDAY MORNING.
HAVE ADDED AREAS OF FOG TO THE FORECAST LATE MONDAY NIGHT THROUGH
MID MORNING TUESDAY. STRATUS LOOKS TO PERSIST ACROSS MUCH OF THE
FORECAST AREA WITH MOSTLY CLOUDY SKIES EXPECTED. ANY VERTICAL MOTION
MOVING ACROSS THE REGION COULD TRIGGER SOME LIGHT DRIZZLE.
TEMPERATURES SHOULD BE ABOVE FREEZING ON TUESDAY...WITH HIGHS IN THE
MID 30S TO AROUND 40 SO ICING SHOULD NOT BE A CONCERN.
AN UPPER LEVEL TROUGH IS EXPECTED TO MOVE FROM THE SOUTHWEST CONUS
INTO THE CENTRAL PLAINS LATE TUESDAY NIGHT. WARM AIR ADVECTION ALOFT
WILL SPREAD ACROSS THE REGION...WITH RAIN AND SNOW DEVELOPING ACROSS
MUCH OF THE FORECAST AREA. AT THIS TIME FORECAST SOUNDINGS APPEAR
WARM ENOUGH FOR THE PRECIPITATION TO FALL AS RAIN. TEMPERATURES LOOK
TO FALL INTO THE 33 TO 36 DEGREE RANGE LATE TUESDAY EVENING THEN
GRADUALLY WARM AFTER MIDNIGHT. WILL HAVE TO CLOSELY MONITOR THE NEXT
FEW MODEL RUNS...IF TEMPERATURES DO NOT WARM AS ANTICIPATED A BRIEF
PERIOD OF FREEZING RAIN MAY DEVELOP LATE TUESDAY NIGHT. HAVE KEPT
PRECIPITATION TYPES AS RAIN/SNOW TUESDAY NIGHT GIVEN THE EXPECTED
TEMPERATURES. FORECAST SOUNDINGS ARE SHOWING SOME ELEVATED CAPE
ACROSS MUCH OF THE FORECAST AREA...WITH AROUND 150 J/KG LIFTING
FROM 730 MB. IF THE ELEVATED CAPE CONTINUES IN THE NEXT SET OF
MODEL RUNS...ISOLATED THUNDER MAY NEED TO BE ADDED TO THE FORECAST
LATE TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.
12.00 GFS AND ECMWF ARE IN REASONABLE AGREEMENT ON WEDNESDAY SHOWING
RAIN PERSISTING THROUGH THE DAY ACROSS THE FORECAST AREA AS THE
UPPER LEVEL TROUGH MOVES FROM THE CENTRAL PLAINS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THE NAM KEEPS THE BULK OF THE PRECIPITATION
ACROSS SOUTHEAST IOWA THROUGH NORTHERN ILLINOIS. HAVE LEANED MORE
TOWARD THE GFS AND ECMWF SOLUTION. FELT THE GFS WAS A BIT OVERDONE
ACROSS SOUTHEAST MINNESOTA INTO NORTHWEST WISCONSIN...PAINTING MUCH
HEAVIER PRECIPITATION ACROSS THE AREA WITH A DEEPER SURFACE LOW OVER
THE OTHER MODELS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE
FORECAST AREA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING WITH
TEMPERATURES FALLING. RAIN SHOULD GRADUALLY CHANGE OVER TO SNOW FROM
NORTHWEST TO SOUTHEAST AS COOLER AIR FILTERS INTO THE AREA. LIGHT
SNOW ACCUMULATION IS POSSIBLE...BUT EXACTLY HOW MUCH WILL FALL WILL
DEPEND ON THE TRACK OF THE LOW AND WHEN THE COOLER AIR WRAPS INTO
THE REGION. LOOK FOR LOW TEMPERATURES TO OCCUR LATE IN THE
NIGHT...WITH TEMPS FALLING INTO THE UPPER 20S ACROSS SOUTHEAST
MINNESOTA THOUGH NORTH CENTRAL WISCONSIN TO THE MID 30S ACROSS FAR
SOUTHWEST WISCONSIN.
.LONG TERM...THURSDAY THROUGH SUNDAY
331 AM CST MON DEC 12 2011
MUCH COLDER AIR WILL PUSH INTO THE AREA ON THURSDAY IN THE WAKE OF A
COLD FRONT...WITH 850 MB TEMPERATURES FALLING FROM 1 C EARLY
THURSDAY MORNING...TO -8 C BY EARLY THURSDAY EVENING. LOOK FOR
TEMPERATURES TO FALL THROUGH THE DAY...WITH READINGS IN THE MID
20S BY LATE THURSDAY AFTERNOON. SOME LIGHT SNOW MAY LINGER ACROSS
THE AREA ON THURSDAY BUT SHOULD QUICKLY TAPER OFF INTO THE
AFTERNOON AS COLD HIGH PRESSURE STARTS TO BUILD IN. LOOK FOR LOWS
TO FALL INTO THE TEENS THURSDAY NIGHT. THE HIGH IS EXPECTED TO
REMAIN OVER THE AREA INTO THE WEEKEND WITH COOL AND QUIET WEATHER
ANTICIPATED. HIGHS WILL BE MAINLY IN THE 20S WITH LOWS IN THE
TEENS. MODELS ARE SHOWING A WARM UP FOR SUNDAY WITH HIGHS CLIMBING
BACK INTO THE MID TO UPPER 30S.
&&
.AVIATION...TODAY AND TONIGHT
534 AM CST MON DEC 12 2011
ABUNDANT LOW LEVEL MOISTURE ALONG WITH A SHORTWAVE TROUGH MOVING
THROUGH MINNESOTA HAS RESULTED IN WIDESPREAD DRIZZLE ACROSS THE
AREA. MOST OF THE PRECIPITATION THUS FAR HAS BEEN AFFECTING THE
KLSE TAF SITE...BUT EXPECT DRIZZLE AT KRST AT TIMES THROUGH MUCH
OF THE DAY ALSO. CEILINGS HAVE REMAINED IN THE UPPER MVFR TO LOWER VFR
CATEGORIES. HOWEVER....BOTH THE 12.07Z RUC AND 13.06Z NAM BUFKIT
SOUNDING CONTINUE TO INDICATE LOWERING CEILINGS THIS MORNING
BETWEEN 12Z-15Z. DID LOWER CEILINGS INTO THE LOWER MVFR
CATEGORY...BUT WILL HAVE WATCH CLOSELY FOR ANY IFR CONDITIONS.
PRECIPITATION WILL COME TO AN END THIS EVENING...WITH A FEW POCKET
OF FREEZING DRIZZLE STILL POSSIBLE. HOWEVER...FELL BETTER CHANCES WILL
BE TO THE EAST OF THE TAF SITES. PRESSURE GRADIENT DOES RELAX
TONIGHT AND WITH THE CONTINUATION OF LOW LEVEL MOISTURE...EXPECT
CEILINGS TO ONCE AGAIN LOWER INTO THE IFR CATEGORY. WITH AN
ADDITIONAL INFLUX OF MOISTURE FROM MELTING SNOW WOULD EXPECT FOG
FORMATION TO OCCUR. DID LOWER VISIBILITIES INTO THE IFR CATEGORY
AFTER 05Z AT BOTH SITES...BUT CANNOT RULE OUT DENSE FOG WITH
VISIBILITIES UNDER ONE QUARTER OF A MILE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
331 AM CST MON DEC 12 2011
WI...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ017-
029-034-042>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
331 AM CST MON DEC 12 2011
.SHORT TERM...TODAY THROUGH WEDNESDAY
331 AM CST MON DEC 12 2011
FORECAST CONCERNS ARE ON DRIZZLE/FREEZING DRIZZLE THIS MORNING AND
AGAIN TONIGHT AND THE POTENTIAL FOR AREAS OF FOG LATE TONIGHT INTO
TUESDAY MORNING. FOCUS THEN TURNS TO STORM SYSTEM EXPECTED TO
IMPACT THE AREA TUESDAY NIGHT INTO WEDNESDAY...WITH PRECIPITATION
TYPE CONCERNS.
CURRENT RADAR AND SURFACE OBSERVATIONS SHOWED DRIZZLE FALLING
ACROSS MUCH OF THE FORECAST AREA. AREAS OF FREEZING DRIZZLE HAVE
BEEN REPORTED ACROSS NORTH CENTRAL WISCONSIN THROUGH SOUTHWEST
WISCONSIN...WITH SOME SECONDARY ROADWAYS VERY SLICK.
DRIZZLE WILL CONTINUE ACROSS THE AREA THIS MORNING AS LOW LEVEL
MOISTURE CONTINUES TO STREAM INTO THE REGION FROM THE SOUTHERN
PLAINS. ISENTROPIC LIFT ON THE 280-300K SURFACE ALONG WITH A WEAK
SHORTWAVE TROUGH MOVING ACROSS THE REGION...WILL ACT TO PRODUCE
DRIZZLE ACROSS MUCH OF THE FORECAST AREA THROUGH THIS AFTERNOON.
SURFACE TEMPERATURES HAVE WARMED ABOVE FREEZING ACROSS MUCH OF THE
FORECAST AREA EARLY THIS MORNING. HOWEVER...SOME SECONDARY ROADWAYS
AND SHADED LOCATIONS WILL LIKELY HAVE SURFACE TEMPERATURES AROUND
FREEZING AND SHOULD EXPERIENCE SOME LIGHT ICING. WILL CONTINUE THE
FREEZING DRIZZLE ADVISORY THROUGH 9 AM FOR THIS LIGHT ICING
POTENTIAL. DRIZZLE AND CLOUDY SKIES CAN BE EXPECTED INTO THIS
EVENING...WITH THE DRIZZLE GRADUALLY TAPERING OFF DURING THE LATE
EVENING INTO THE OVERNIGHT HOURS. SOME PATCHY FREEZING DRIZZLE CAN
BE EXPECTED ACROSS WESTERN AND CENTRAL WISCONSIN...WHERE A FEW
LOCATIONS WILL DROP TO FREEZING. AT THIS TIME IT APPEARS ICING WILL
BE MINIMAL BUT WILL HAVE TO CLOSELY MONITOR TEMPERATURES THROUGH THE
DAY TODAY. IF TEMPERATURES COOL FURTHER THAN WHAT IS CURRENTLY
ANTICIPATED...A FREEZING RAIN ADVISORY MAY BE NEEDED THIS EVENING
INTO TONIGHT...ESPECIALLY ALONG AND NORTH OF THE I-94 CORRIDOR. LOOK
FOR LOW TEMPERATURES TO FALL INTO THE LOWER 30S TONIGHT UNDER CLOUDY
SKIES.
LOW LEVEL MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA ON TUESDAY
WITH WEAK RIDGING ALOFT MOVING OVERHEAD. WITH LIGHT AND VARIABLE
WINDS ACROSS THE REGION AND ANY REMAINING SNOW MELTING...AREAS OF
FOG MAY DEVELOP AND COULD POTENTIALLY BE DENSE EARLY TUESDAY MORNING.
HAVE ADDED AREAS OF FOG TO THE FORECAST LATE MONDAY NIGHT THROUGH
MID MORNING TUESDAY. STRATUS LOOKS TO PERSIST ACROSS MUCH OF THE
FORECAST AREA WITH MOSTLY CLOUDY SKIES EXPECTED. ANY VERTICAL MOTION
MOVING ACROSS THE REGION COULD TRIGGER SOME LIGHT DRIZZLE.
TEMPERATURES SHOULD BE ABOVE FREEZING ON TUESDAY...WITH HIGHS IN THE
MID 30S TO AROUND 40 SO ICING SHOULD NOT BE A CONCERN.
AN UPPER LEVEL TROUGH IS EXPECTED TO MOVE FROM THE SOUTHWEST CONUS
INTO THE CENTRAL PLAINS LATE TUESDAY NIGHT. WARM AIR ADVECTION ALOFT
WILL SPREAD ACROSS THE REGION...WITH RAIN AND SNOW DEVELOPING ACROSS
MUCH OF THE FORECAST AREA. AT THIS TIME FORECAST SOUNDINGS APPEAR
WARM ENOUGH FOR THE PRECIPITATION TO FALL AS RAIN. TEMPERATURES LOOK
TO FALL INTO THE 33 TO 36 DEGREE RANGE LATE TUESDAY EVENING THEN
GRADUALLY WARM AFTER MIDNIGHT. WILL HAVE TO CLOSELY MONITOR THE NEXT
FEW MODEL RUNS...IF TEMPERATURES DO NOT WARM AS ANTICIPATED A BRIEF
PERIOD OF FREEZING RAIN MAY DEVELOP LATE TUESDAY NIGHT. HAVE KEPT
PRECIPITATION TYPES AS RAIN/SNOW TUESDAY NIGHT GIVEN THE EXPECTED
TEMPERATURES. FORECAST SOUNDINGS ARE SHOWING SOME ELEVATED CAPE
ACROSS MUCH OF THE FORECAST AREA...WITH AROUND 150 J/KG LIFTING
FROM 730 MB. IF THE ELEVATED CAPE CONTINUES IN THE NEXT SET OF
MODEL RUNS...ISOLATED THUNDER MAY NEED TO BE ADDED TO THE FORECAST
LATE TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.
12.00 GFS AND ECMWF ARE IN REASONABLE AGREEMENT ON WEDNESDAY SHOWING
RAIN PERSISTING THROUGH THE DAY ACROSS THE FORECAST AREA AS THE
UPPER LEVEL TROUGH MOVES FROM THE CENTRAL PLAINS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THE NAM KEEPS THE BULK OF THE PRECIPITATION
ACROSS SOUTHEAST IOWA THROUGH NORTHERN ILLINOIS. HAVE LEANED MORE
TOWARD THE GFS AND ECMWF SOLUTION. FELT THE GFS WAS A BIT OVERDONE
ACROSS SOUTHEAST MINNESOTA INTO NORTHWEST WISCONSIN...PAINTING MUCH
HEAVIER PRECIPITATION ACROSS THE AREA WITH A DEEPER SURFACE LOW OVER
THE OTHER MODELS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE
FORECAST AREA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING WITH
TEMPERATURES FALLING. RAIN SHOULD GRADUALLY CHANGE OVER TO SNOW FROM
NORTHWEST TO SOUTHEAST AS COOLER AIR FILTERS INTO THE AREA. LIGHT
SNOW ACCUMULATION IS POSSIBLE...BUT EXACTLY HOW MUCH WILL FALL WILL
DEPEND ON THE TRACK OF THE LOW AND WHEN THE COOLER AIR WRAPS INTO
THE REGION. LOOK FOR LOW TEMPERATURES TO OCCUR LATE IN THE
NIGHT...WITH TEMPS FALLING INTO THE UPPER 20S ACROSS SOUTHEAST
MINNESOTA THOUGH NORTH CENTRAL WISCONSIN TO THE MID 30S ACROSS FAR
SOUTHWEST WISCONSIN.
.LONG TERM...THURSDAY THROUGH SUNDAY
331 AM CST MON DEC 12 2011
MUCH COLDER AIR WILL PUSH INTO THE AREA ON THURSDAY IN THE WAKE OF A
COLD FRONT...WITH 850 MB TEMPERATURES FALLING FROM 1 C EARLY
THURSDAY MORNING...TO -8 C BY EARLY THURSDAY EVENING. LOOK FOR
TEMPERATURES TO FALL THROUGH THE DAY...WITH READINGS IN THE MID
20S BY LATE THURSDAY AFTERNOON. SOME LIGHT SNOW MAY LINGER ACROSS
THE AREA ON THURSDAY BUT SHOULD QUICKLY TAPER OFF INTO THE
AFTERNOON AS COLD HIGH PRESSURE STARTS TO BUILD IN. LOOK FOR LOWS
TO FALL INTO THE TEENS THURSDAY NIGHT. THE HIGH IS EXPECTED TO
REMAIN OVER THE AREA INTO THE WEEKEND WITH COOL AND QUIET WEATHER
ANTICIPATED. HIGHS WILL BE MAINLY IN THE 20S WITH LOWS IN THE
TEENS. MODELS ARE SHOWING A WARM UP FOR SUNDAY WITH HIGHS CLIMBING
BACK INTO THE MID TO UPPER 30S.
&&
.AVIATION...THROUGH 06Z TUESDAY
1135 PM CST SUN DEC 11 2011
CEILINGS HAVE ACTUALLY LIFTED ACROSS THE AREA THIS EVENING AND
WILL START THE TAFS OUT WITH EITHER MVFR OR VFR CEILINGS BUT WITH
MVFR VISIBILITIES FROM SOME LIGHT FOG. STILL EXPECTING CONDITIONS
TO DETERIORATE LATER TONIGHT AS THE SHORT WAVE TROUGH APPROACHES
AND INCREASES THE LIFT. THE 12.03Z RUC AND 12.00Z NAM NOW SUGGESTS
THE LOWER CEILINGS...VISIBILITY AND DRIZZLE WILL BE SLOWER TO
ARRIVE AND PUSHED THIS BACK TO AROUND 10Z BUT THERE ARE SOME
INDICATIONS IT COULD EVEN HOLD OFF LONGER. TEMPERATURES STILL TO
BE WARM ENOUGH TO KEEP THE PRECIPITATION AS DRIZZLE WITH LITTLE
THREAT FOR ANY FREEZING DRIZZLE AT THE TAF SITES. THE DRIZZLE
SHOULD BEGIN TO TAPER OFF DURING THE AFTERNOON AND HAVE PUSHED
BOTH THE VISIBILITY AND CEILING UP A LITTLE AS THIS OCCURS. THE
LOW LEVEL MOISTURE DOES NOT GET CLEANED OUT OF THE AREA WITH THE
FLOW REMAINING OUT OF THE SOUTH OR SOUTHWEST THROUGH 06Z MONDAY SO
VERY POSSIBLE THAT THE CEILINGS WILL START TO GO DOWN AGAIN MONDAY
EVENING WITH SOME COOLING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
331 AM CST MON DEC 12 2011
WI...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ017-
029-034-042>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 PM CST SUN DEC 11 2011
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
250 PM CST SUN DEC 11 2011
AMPLE CHALLENGES TO THE FORECAST FOR THE NEXT FEW DAYS...WITH THE
FOCUS ON THE PCPN TYPE.
TONIGHT AND MONDAY NOT LOOKING AS CLEAR-CUT AS THE PAST FEW DAYS
SUGGESTED IT WOULD BE...WITH FREEZING DRIZZLE TO DRIZZLE AND BACK
OVER TO FREEZING DRIZZLE. PCPN WILL OCCUR FOR THE REGION...BUT WHAT
FALLS IS MORE HAZY NOW.
LATEST FOG/STRATUS SATELLITE IMAGERY INDICATES AN EXPANSIVE AREA OF
STRATUS MOVING NORTHEAST ACROSS THE PLAINS...SURGING ACROSS THE
LOCAL AREA. THIS WAS IN RESPONSE TO A WARM/MOIST PUSH OF LOW LEVEL
AIR RIDING ACROSS A SNOW PACK. DESPITE WINDS OF 10 KTS OR
GREATER...VSBYS WITH THE STRATUS ARE 2-4 MILES...BRINGING AN ASPECT
OF ADVECTION FOG TO THE FORECAST.
THE FAVORABLE LOW LEVEL MOISTURE TRANSPORT/WARM AIR ADVECTION NOSES
ACROSS THE FORECAST AREA TONIGHT...PERSISTING THROUGH MUCH OF
MONDAY. THIS IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE THAT WILL
SPIN FROM THE CENTRAL PLAINS TO ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY BY 18Z MON. THE SATURATION IS ALL IN THE LOW LEVELS
THOUGH...AS EVIDENCED BY TIME/HEIGHT X-SECTIONS AND BUFKIT
SOUNDINGS. AS SUCH...THE DEPTH OF THE SATURATION AND TEMPS AT THE
TOP OF THE ANTICIPATED CLOUD LAYER WILL HAVE AN IMPACT ON THE PCPN
TYPE. PREVIOUS MODEL RUNS POINTED TO NO ICE IN THE CLOUD...THUS
LIQUID AND LIKELY DRIZZLE. HOWEVER...INDICATIONS NOW ARE THAT -10 TO
-12 C COULD BE REALIZED IN CLOUD TOPS...MAKING ICE MORE LIKELY AND
POTENTIALLY SNOW IF THE REST OF THE THERMAL PROFILE WOULD SUPPORT
IT. IN ADDITION...THE SATURATION COULD BECOME DEEP ENOUGH FOR A
PERIOD ON SAT WHERE RAIN WOULD BE MORE LIKELY RATHER THAN DRIZZLE.
ACCUMULATION WOULD STILL BE MINOR...AND BELIEVE DRIZZLE WILL BE THE
MORE PREDOMINANT LIQUID TYPE...SO WILL STAY WITH DRIZZLE FOR NOW.
ANOTHER QUESTION THAT HAS BECOME PROBLEMATIC ARE SFC TEMPS.
PREVIOUSLY FREEZING TEMPERATURES OVERNIGHT/MONDAY MORNING LOOKED
LIKE A SURE THING FOR THE ENTIRE FORECAST AREA. LATEST MODELS RUNS
BRING THIS INTO QUESTION. THE LOW LEVEL WARM AIR ADVECTION WILL NOT
ONLY GO INTO CLOUD/PCPN PRODUCTION LATE TONIGHT...BUT IT SHOULD ALSO
SERVE TO HELP STEADY...OR EVEN RISE...TEMPERATURES OVERNIGHT. IF
THIS OCCURS...WESTERN PARTS OF THE FORECAST AREA HAVE A
PRETTY GOOD CHANCE OF STAYING ABOVE FREEZING. LATEST RUC13 TEMPS AND
LAMP GUIDANCE SUPPORTS THIS...AND HAVE TAILORED TEMPS TONIGHT THIS
WAY. AS A RESULT...THE WESTERN 1/2 OF THE FORECAST AREA WILL LIKELY
MISS OUT ON ANY FREEZING DRIZZLE. FARTHER EAST THOUGH TEMPS HAVE A
MUCH BETTER CHANCE TO COOL TO FREEZING...AND THUS AN ICING THREAT
WHEN THE DRIZZLE MOVES IN. WILL GO WITH A FREEZING RAIN ADV FOR THE
COUNTIES IN THE EAST...ESPECIALLY IN THE I-94 CORRIDOR...FROM 09-15Z
MON.
THIS SCENARIO WILL HAVE TO BE MONITORED VERY CLOSELY TONIGHT...AS
THE AMOUNT OF WARMING AND ONSET OF THE DRIZZLE WILL OBVIOUSLY PLAY
KEY ROLES IN WHERE THE FREEZING DRIZZLE THREAT WILL BE HIGHEST.
AN UPPER LEVEL TROUGH WILL LIFT OUT OF THE DESERT
SOUTHWEST...BRINGING THE TROUGH AXIS ACROSS THE REGION ON WED. THIS
SYSTEM LOOKS LIKE IT COULD PACK A PRETTY GOOD PUNCH WITH GOOD QG
CONVERGENCE...SLOPING FRONTOGENETIC LIFT...AND THE ENERGY FROM THE
UPPER LEVEL SHORTWAVE. TIMING AND POSITIONING WILL PLAY AN IMPORTANT
ROLE AS WARM AIR WILL BE A FACTOR FOR PCPN TYPE.
UNFORTUNATELY...EACH MODEL HAS A DIFFERENT IDEA ON WHAT WILL
OCCUR...AND BRINGS THE FORECAST CONFIDENCE DOWN AS A RESULT. NAM IS
THE QUICKEST OF ALL...TAKING THE SFC LOW TO LAKE SUPERIOR BY 00Z
THU. THE GFS IS OVER SOUTHWEST IA...THE EC THE CENTRAL PLAINS...AND
THE GEM EASTERN IA. A LOT OF INCONSISTENCY WITHIN THE MODELS
TOO...EXCEPT FOR THE EC WHICH SHOWS A BIT BETTER RUN TO RUN
AGREEMENT. WILL LEAN ON THE EC AS A RESULT...BLENDING IT WITH THE
CONSENSUS SOLUTION.
BEFORE THE HEART OF THE SYSTEM MOVES IN WED
AFTERNOON/NIGHT...ANOTHER GOOD SURGE OF LOW LEVEL MOISTURE
TRANSPORT/WARM AIR ADVECTION TUE NIGHT/WED MORNING WILL LIKELY LEAD
TO A BROAD AREA OF PRECIPITATION SPREADING ACROSS PORTIONS OF THE
REGION. SATURATION LOOKS DEEP ENOUGH TO SUPPORT ICE IN THE
CLOUD...BUT WARMING IN THE NEAR SFC LAYER SUGGESTS MELTING AND THE
POTENTIAL FOR RAIN OR FREEZING RAIN. THE WARMING CONTINUES FOR THE
REST OF WED AS THE MAIN PART OF THE STORM MOVES IN...WITH RAIN THE
LIKELY PCPN TYPE AS A RESULT. LOOKS LIKE ANY SNOW BAND WITH THIS
STORM WILL HANG WELL WEST/NORTH. OVERALL...CONFIDENCE IS HIGH THAT
PRECIPITATION WILL OCCUR. WHEN ITS MOST LIKELY IS NOT. CONFIDENCE IS
ALSO RISING THAT IT WILL LIKELY BE RAIN FOR THE MAJORITY OF THE
EVENT.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
250 PM CST SUN DEC 11 2011
MODEL DIFFERENCES CONTINUE...LOWERING CONFIDENCE IN SOME OF THE
DETAILS. WHILE THE GFS HAS MOVED TO A NORTHWEST STORM TRACK ALA THE
ECMWF AND GEM...STILL LOTS OF TIMING VARIANCE ON HOW QUICKLY THE
SYSTEM WILL KICK NORTHEAST. THE GFS IS THE FAST SOLUTION...WITH THE
EC SLOWER AND THE GEM IN BETWEEN. THE EC WOULD LINGER PCPN LONGER
OVER THE FORECAST AREA...CONTINUING INTO THU. ALSO...WITH THE EC
STAYING THE FARTHEST WEST...ITS ALSO MUCH WARMER MAKING RAIN A
MORE LIKELY PCPN TYPE FOR A LONGER STRETCH OF TIME. PCPN TYPE WILL
BE A DIFFICULTY WITH THIS STORM. WILL CONTINUE TO LEAN ON THE
EC/CONSENSUS SOLUTION FOR NOW.
HIGH PRESSURE STARTS TO BUILD IN FROM THE WEST THU NIGHT...MOVING
OVERHEAD FOR SAT WHILE THE UPPER LEVEL FLOW TAKES ON A MORE ZONAL
SHAPE FOR THE WEEKEND. FRI/SAT SHOULD BE DRY WITH SEASONAL TEMPS.
&&
.AVIATION...THROUGH 06Z TUESDAY
1135 PM CST SUN DEC 11 2011
CEILINGS HAVE ACTUALLY LIFTED ACROSS THE AREA THIS EVENING AND
WILL START THE TAFS OUT WITH EITHER MVFR OR VFR CEILINGS BUT WITH
MVFR VISIBILITIES FROM SOME LIGHT FOG. STILL EXPECTING CONDITIONS
TO DETERIORATE LATER TONIGHT AS THE SHORT WAVE TROUGH APPROACHES
AND INCREASES THE LIFT. THE 12.03Z RUC AND 12.00Z NAM NOW SUGGESTS
THE LOWER CEILINGS...VISIBILITY AND DRIZZLE WILL BE SLOWER TO
ARRIVE AND PUSHED THIS BACK TO AROUND 10Z BUT THERE ARE SOME
INDICATIONS IT COULD EVEN HOLD OFF LONGER. TEMPERATURES STILL TO
BE WARM ENOUGH TO KEEP THE PRECIPITATION AS DRIZZLE WITH LITTLE
THREAT FOR ANY FREEZING DRIZZLE AT THE TAF SITES. THE DRIZZLE
SHOULD BEGIN TO TAPER OFF DURING THE AFTERNOON AND HAVE PUSHED
BOTH THE VISIBILITY AND CEILING UP A LITTLE AS THIS OCCURS. THE
LOW LEVEL MOISTURE DOES NOT GET CLEANED OUT OF THE AREA WITH THE
FLOW REMAINING OUT OF THE SOUTH OR SOUTHWEST THROUGH 06Z MONDAY SO
VERY POSSIBLE THAT THE CEILINGS WILL START TO GO DOWN AGAIN MONDAY
EVENING WITH SOME COOLING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST SUN DEC 11 2011
WI...FREEZING RAIN ADVISORY FROM 3 AM TO 9 AM CST MONDAY FOR WIZ017-
029-034-042>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1257 AM EST WED DEC 14 2011
UPDATED AVIATION DISCUSSION FOR 06Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH OVER THE WRN CONUS
AND A RIDGE OVER THE SE WITH MAINLY ZONAL FLOW FROM THE NRN PLAINS
TO NEW ENGLAND. A VIGOROUS SHORTWAVE TROUGH WAS MOVING THROUGH AZ
WHILE A WEAKER UPSTREAM SHRTWV WAS MOVING INTO SRN SD. AT THE
SFC...A RIDGE EXTENDED FROM NORTHERN QUEBEC TO LAKE SUPERIOR
RESULTING IN WEAK ACYC FLOW OVER THE CWA WITH NO PCPN INDICATED BY
RADAR. WITH THE MILD/MOIST AIRMASS IN PLACE...PATCHY FOG LINGERED
OVER LOCATIONS NEAR THE WI BORDER.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
TONIGHT...AS THE HIGH SLIDES OFF TO THE SE...SRLY LOW LEVEL FLOW
WILL INCREASE WEAK UPSLOPE FLOW INTO PORTIONS OF WEST AND CENTRAL
UPPER MI MAY BE ENOUGH TO SUPPORT SOME PATCHY -DZ/-FZDZ AFT 06Z EVEN
THOUGH OVERALL LOW LEVEL (925-850 MB) LIFT IS VERY WEAK...PER
NAM/RUC...280K ISENTROPIC PROGS. OTHERWISE...WITH LITTLE DIURNAL
TEMP CHANGE IS EXPECTED OVER THE AREA. AREAS OF FOG...SOME LCLY
DENSE...MAY ALSO THICKEN WITH SLIGHT INCREASE IN MOISTURE ADVECTION.
WEDNESDAY...AS LOW PRESSURE DEVELOPS IN THE CENTRAL PLAINS AND MOVES
TOWARD THE UPPER MS VALLEY...LOW/MID LEVEL WAA AND MOISTURE
ADVECTION WILL INCREASE. THIS SHOULD BRING AN AREA OF LIGHT PCPN
OVER THE ENTIRE CWA BY AFTERNOON...PER NAM/GFS 290K-295K ISENTROPIC
PROGS. NAM WET-BULB ZERO HEIGHTS SUGGEST THAT THE PCPN SHOULD BE
MAINLY RAIN. HOWEVER...GIVEN LOW LEVEL TEMP PROFILES NEAR 0C OVER
THE INTERIOR WEST...CANNOT RULE OUT SOME SNOW. ANY ACCUMULATIONS
WOULD BE MINIMAL. EVEN THOUGH TEMPS WILL BE ABOVE FREEZING WHEN THE
RAIN ARRIVES...SOME UNTREATED ROADS MAY STILL BE COLD ENOUGH TO
CREATE PATCHY ICY SPOTS.
.LONG TERM /WED NIGHT THROUGH NEXT TUESDAY/...
SHORTWAVE CURRENTLY ROUNDING THE UPPER TROUGH OFF THE COAST OF SRN
CA WILL MOVE TOWARDS THE AREA LATE WED AFTN AND MOVE ACROSS THE AREA
WED EVENING. MODELS FAIRLY CONSISTENT ON THE MAIN ENERGY FROM THE
SHORTWAVE MOVING ACROSS CNTRL/ERN UPPER MI...WHICH WILL GRADUALLY
INTENSIFY THE LOW MOVING FROM IOWA AT 00Z THURS TO SE ONTARIO AT 12Z
THURS. OTHER THAN THE FAST AND NW OUTLIER 12Z NAM...MAIN DIFFERENCES
BETWEEN THE MODELS IS IN THE INTENSITY OF THE LOW. 06-12Z GFS RUNS
ON THE STRONG SIDE AND 00Z ECMWF ON WEAKER SIDE. WILL FOLLOW A BLEND
OF THE TWO SINCE TRACKS ARE SIMILAR AND ONLY MINOR DIFF IN THE
THERMAL PROFILES.
DURING THE EVENING...06 AND 12Z GFS SHOWING STRONG FGEN FROM
H800-400 ACROSS THE CWA. THINK THE BEST FORCING WILL BE ALONG THE
H800-600 FGEN AREA...WHERE THERE IS ABUNDANT MOISTURE AND STRONG
AGEOSTROPHIC UPWARD CIRCULATION. FARTHER NW...APPEARS TO BE A DECENT
H700-500 DRY AIR LAYER...AND DOWNWARD CIRCULATION MAY LIMIT PCPN
FARTHER NW TOWARDS A KIWD TO KCMX LINE. OVER THE E...EXPECT A STRONG
AREA OF H850-700 WAA AND 285-300K SFC ISENTROPIC ASCENT DURING THE
EVENING. THINK THE EXISTING 100 POPS LOOK GOOD AND WILL LEAVE THEM
AS IS. THEN HAVE A GRADUAL LOWERING HEADING OVER THE WEST TOWARDS
HIGH END LIKELY. COULD BE A SHARP CUTOFF TO THE WEST EXTENT OF THE
PCPN OVER THE WRN HALF OF LK SUPERIOR WITH THE FGEN CIRCULATION...SO
TRIED TO SHOW THAT POTENTIAL.
P-TYPE FOR THE WED NIGHT PERIOD IS WHERE THINGS GET TRICKY. BUFKIT
SOUNDINGS FROM THE GFS SHOW AN ISOTHERMAL PROFILE FROM SFC TO
5-6KFT. WITH THAT TYPE OF SITUATION...IT WILL LIKELY BE SNOW WHERE
LAYER IS NEAR 0C AND THEN RA/SN AROUND 1C AND ALL RA AROUND 2-3C.
KCMX MAY BE FAR ENOUGH N AND AWAY FROM THE WARM SURGE TO KEEP PCPN A
RA/SN MIX OR POSSIBLY EVEN ALL SNOW. THEN HEADING S AND E ACROSS THE
CWA...EXPECT A TRANSITION TO ALL RAIN. BIGGEST CONCERN IS GETTING
THAT RA/SN AREA PINNED DOWN AND STILL DON/T HAVE A GREAT FEEL...BUT
IT SHOULD BE OVER THE NW THIRD. FORTUNATELY...THE HEAVIEST QPF WILL
LIKELY BE TO THE SE OF THE UNCERTAIN AREA FOR RA/SN...SO IT SHOULD
LIMIT THE IMPACT IF IT DOES END UP ALL SNOW.
LAST COUPLE OF RUNS OF THE GFS HAVE REALLY BUMPED UP THE QPF IN THE
FGEN LOCATION MOVING ACROSS CNTRL UPPER MI...WITH LIQUID AMOUNTS
EXCEEDING 0.75IN...BUT IT IS LIKELY DUE TO THE MORE WRAPPED UP LOW
SOLN. WILL NOT GO THAT HIGH...BUT WILL NEED TO BE MONITORED IF
STRONGER LOW SOLN PANS OUT. OTHERWISE...EXPECT 0.25 TO 0.4 OF LIQUID
ACROSS THE SE HALF OF THE CWA...MAINLY DURING THE EVENING.
MAIN ENERGY AND DEEPER H700-500 MOISTURE PULLS OUT OVERNIGHT WED AND
HAVE DIMINISHING POPS TO ACCOUNT FOR THAT. P-TYPE IS AGAIN A CONCERN
HEADING INTO THE OVERNIGHT...SINCE THE DEEPER MOISTURE PULLS OUT
BEFORE THE COLDER AIR ARRIVES LATE WED NIGHT INTO THURS. THIS WILL
CUT THE POTENTIAL FOR ICE CRYSTALS IN THE CLOUD WAY DOWN AND LIMIT
THE POTENTIAL FOR SNOW. WITH TEMPERATURES DROPPING TOWARDS FREEZING
OVER THE WEST TOWARDS 12Z THURS...DID KEEP A MENTION OF -FZRA IN THE
FORECAST LATE...BUT POTENTIAL SEEMS LIMITED DURING THE OVERNIGHT
HOURS WITH THE SHORT PERIOD OF AT OR BELOW FREEZING TIME.
OTHERWISE...WILL ONLY MENTION A LOW CHANCE FOR SNOW OVER THE WEST
OVERNIGHT DUE TO LIMITED ICE CRYSTAL PRESENCE AND RAIN OVER THE
CENTRAL AND EAST. THINK THE BIGGEST HAZARD IS MORE LIKELY TO BE THE
WET ROADS ICING UP ON THURS...AS TEMPS FALL BELOW FREEZING THROUGH
THE DAY.
NRN STREAM UPPER TROUGH WILL SWEEP THROUGH THE CWA ON THURS. STILL
DIFFERENCES IN THE SPEED/INTENSITY IN THE MODELS WITH THIS
WAVE...BUT ALL HAVE THE GENERAL IDEA OF IT MOVING THROUGH THE UPPER
GREAT LKS ON THURS. THIS WAVE WILL DROP H850 TEMPS THROUGH THE DAY
TO -12C OVER THE W BY 00Z FRI. THESE COLDER TEMPS WILL STAY OVER THE
AREA THROUGH THE DAY FRI...ANOTHER WEAKER SHORTWAVE DROPS ACROSS THE
AREA. WITH TEMPS ALOFT PUTTING THE CLOUD LAYER BACK INTO THE ICE
CRYSTAL AREA ON THURS...EXPECT TO CHANCES FOR SNOW AS THE P-TYPE TO
BE ON THE INCREASE FROM WEST TO EAST. SHORTWAVE ENERGY WILL HELP
ENHANCE THE DEVELOPING LES THROUGH THE DAY. WILL CONTINUE TREND OF
HIGHER POPS OVER THE WEST IN THE MORNING WITH LES DEVELOPING AND
SHORTWAVE ARRIVING...THEN INCREASE LES POPS OVER THE E UNDER NW
WINDS IN THE AFTN INTO THURS NIGHT. IN ADDITION...WITH THE LOW
INTENSIFYING TO THE NE OF THE AREA...EXPECT A BREEZY DAY ON THURS
ACROSS THE AREA. THE HIGHEST WINDS SHOULD BE OVER THE E NEAR LK
SUPERIOR...WHERE WINDS COULD GUST TO 40-45MPH LATE IN THE AFTERNOON.
SFC RIDGE QUICKLY MOVES FROM W TO E OVER THE CWA ON THURS NIGHT INTO
FRI. MODELS SHOWING VERY PRONOUNCED H925-700 DRYING WITH THE ARRIVAL
OF THE RIDGE...SO HAVE TRENDED BACK LES POPS...ESPECIALLY OVER THE
WEST WHERE BUFKIT SOUNDINGS SHOWING INVERSION HEIGHTS FALLING
TOWARDS 3KFT. DID KEEP LIKELY/S OVER THE NW WIND FAVORED E LOCATIONS
THURS NIGHT INTO FRI MORNING...BUT DROPPED TO CHANCES IN THE AFTN AS
THE DRY AIR LIMITS POTENTIAL.
DAYS 4 THROUGH 7 /FRI NIGHT THROUGH NEXT TUESDAY/...
WEAK SHORTWAVE MOVING ACROSS THE AREA FRI NIGHT WILL BRING A LITTLE
MORE MOISTURE TO THE AREA AND KEEP COLDER AIR IN PLACE. EXPECT
ONGOING LES TO CONTINUE OVER THE E...WITH WINDS GRADUALLY SHIFTING
MORE WRLY. LES MAY TRY TO REDEVELOP OVER THE W WITH THE ARRIVAL OF
THE SHORTWAVE AND ADDITIONAL LLVL MOISTURE. WILL GO WITH LOW CHANCES
OVER THE KEWEENAW WITH THE MORE WRLY WINDS AND THEN LOW END LIKELY/S
OVER THE EAST.
UPPER TROUGH SHIFTS E ON SAT AND DRAGS A SFC TROUGH OVER NRN LK
SUPERIOR AND SRN ONTARIO THROUGH THE DAY AND INTO SAT NIGHT. THERE
HAS BEEN A STRONGER TREND WITH THE SFC FEATURES AND UPPER FORCING
OVER THE LAST DAY FOR THE SAT AND SAT NIGHT PERIOD...SO HAVE BUMPED
POPS UP TO SLIGHTS OVER THE NRN U.P. AND CHANCES OVER THE LAKE.
SOME DIFFERENCES APPEAR IN THE EXTENDED MODELS ON SUN INTO MON WITH
THE HANDLING OF A POTENTIAL RIDGE IN THE NRN STREAM AND A CLOSED LOW
OVER THE SW CONUS. LATEST 12Z RUN OF THE GFS HAS TRENDED SLOWER WITH
THE EXIT OF THE UPPER LOW OVER THE SW CONUS SUN INTO MON...AND MORE
IN LINE WITH THE 00Z ECMWF...SO HAVE FOLLOWED THAT FOR THE REST OF
THE EXTENDED. SFC RIDGE WILL MOVE ACROSS THE CWA ON SUN INTO SUN
NIGHT. NRN STREAM SHORTWAVE WILL APPROACH THE AREA MON INTO
TUES...BRINGING ANOTHER LOW CHANCE OF PCPN. HAS BEEN A GOOD AMOUNT
OF FLUCTUATION IN H850 TEMPS AFTER SUN...SO HAVE LIMITED CONFIDENCE
IN VALUES...BUT APPEARS THAT TEMPS WILL SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
LOW-LEVELS WILL REMAIN MOIST THROUGH THE TAF PERIOD AS A LOW
PRESSURE SYSTEM OVER THE CENTRAL PLAINS LIFTS NORTH INTO THE UPPER
GREAT LAKES ON WEDNESDAY. LIMITED MIXING TONIGHT...MOIST LOW-LVLS
AND LIGHT UPSLOPE SE FLOW SHOULD LEAD TO LIFR TO VLIFR CONDITIONS IN
STRATUS/FOG AT KSAW. TRICKIER FCST IN STORE FOR KCMX AND KIWD
OVERNIGHT AS SE FLOW IS MORE DOWNSLOPE FOR THESE LOCATIONS WHICH
COULD MITIGATE STRATUS/FOG. LOOK FOR ONLY IFR CONDITIONS AT KCMX AND
VFR TO POSSIBLY MVFR CIGS AT KIWD.
IN GENERAL...SIGNIFICANT IMPROVEMENT IS NOT ANTICIPATED THROUGH
WEDNESDAY MORNING AT ANY OF THE TAF SITES. RAIN IS EXPECTED BY WED
AFTERNOON AS SYSTEM APPROACHES FROM THE CENTRAL PLAINS. THIS
ADDITIONAL MOISTURE FROM THE RAIN COMBINED WITH A SHIFT TO MORE
WESTERLY UPSLOPE WINDS BEHIND THE LOW PRES SYSTEM WILL LIKELY LOWER
CONDITIONS TO LIFR OR VLIFR AT BOTH KCMX AND KIWD BY WED EVENING. AT
KSAW...EXPECT LIFR CONDITIONS TO LOWER TO VLIFR BY LATE WED
AFTERNOON IN CONTINUED MOIST UPSLOPE FLOW. ONLY CHANCE FOR MARGINAL
IMPROVEMENT WOULD BE A SHIFT TO WRLY WINDS LATE EVENING BEHIND THE
SYSTEM/S COLD FRONT.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LIGHT SOUTHERLY WINDS WILL INCREASE INTO THE 15 TO 25 KT RANGE OVER
THE CENTRAL AND EAST PORTIONS OF THE LAKE WED AHEAD OF LOW PRESSURE
DEVELOPING IN THE PLAINS. THE LOW IS FCST TO DEEPEN AS IT LIFTS
ACROSS THE UPPER LAKES BY THURSDAY MORNING. STRONGEST WINDS THIS
WEEK WILL OCCUR JUST IN THE WAKE OF THE LOW THURSDAY MORNING THROUGH
MIDNIGHT THURSDAY NIGHT. CONFIDENCE THAT 35-40 KT GALES WILL OCCUR
IS HIGH SO THE WATCH CONTINUES FOR MUCH OF LK SUPERIOR. STRONG WINDS
WILL DIMINISH ON FRI WITH THE SLOW APPROACH OF A HIGH PRESSURE
RIDGE. A STRONGER SW FLOW WILL REDEVELOP ON SAT AFTER THIS HIGH
SHIFTS TO THE SE WITH WINDS TO AROUND 30 KT OVER WEST AND CENTRAL
PORTIONS OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
402 AM CST WED DEC 14 2011
.DISCUSSION...
A BIT OF A TRICKY FORECAST THIS MORNING WITH THE FIRST WAVE MOVING
THROUGH EAST CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN. RAIN
AND SNOW MIXED OCCURRING OVER PARTS OF CENTRAL MINNESOTA AND
WESTERN WISCONSIN. THE LATEST RUC AND VSREF PICKING UP ON THE LOW
LEVEL THICKNESS FIELDS AND MARGINAL 850 MB TEMPS AND IT COULD BE
ALL SNOW FOR A TIME EARLY. NOT MENTIONING MUCH ACCUMULATION AT
THIS POINT /LESS THAN AN INCH/ WITH MUCH OF THE FORCING MOVING
OUT. OTHERWISE WE WILL BE LEFT WITH MOST OF THE REMAINDER OF THE
MORNING WITH NOT REAL WIDESPREAD PRECIP...MOSTLY DRIZZLE.
FORTUNATELY...TEMPS MAINLY ABOVE 32 OR JUST AT 32 WHERE SOME SNOW
MOST ROAD TEMPS ON THE ARE NOT SUGGESTING A MAJOR THREAT FOR ICE.
MAY STILL INCLUDE A MENTION OF FREEZING DRIZZLE IN CENTRAL MN.
THE NAM AND GFS AND ARE GENERALLY IN LINE WITH BRINGING THE
SOUTHERN ROCKIES VORT NORTHEAST TOWARD IOWA WITH SIG FORCING
BRUSHING SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN DURING
THE AFTERNOON AND EVENING. THE TEMP STRUCTURE IS STILL INITIALLY
TOO WARM FOR MUCH SNOW BUT COOLING DOES TAKE PLACE AS THE 500 MB
HEIGHT FALLS TRACK ACROSS NORTHEAST IOWA. HAVE INDICATED NEAR AN
INCH OF SNOW FOR PARTS OF EAST CENTRAL MN AND WEST CENTRAL
WISCONSIN BUT WILL NEED TO WATCH THE TRENDS DURING THE DAY. THERE
IS CERTAINLY PLENTY OF MOISTURE WITH PWAT VALUES OVER 300 PERCENT
OF NORMAL THROUGH THE CENTRAL PLAINS.
BLUSTERY AND COLDER CONDITIONS MOVE IN FOR THURSDAY WITH COLD
ADVECTION KEEPING TEMP TRENDS STEADY FROM OVERNIGHT LOWS IN SOME
AREAS.
THE CLIPPER TYPE SYSTEM MOVING INTO THE AREA ON FRIDAY LOOKS
WELL DEFINED BUT LACKING MOISTURE. HAVE INTRODUCED AT LEAST A SLIGHT
CHANCE FOR LIGHT SNOW IN THE WEST BUT THERE MAY BE A NEED TO
EXPAND THAT IN LATER FORECASTS. SATURDAY LOOKS MILD BEHIND THAT
SYSTEM WITH DECENT CHANCE OF BRINGING SOME LOW 40S INTO THE
SOUTHWEST..EAST OF THE BUFFALO RIDGE.
ANOTHER SYSTEM IN THE SPLIT FLOW WILL NEED TO BE WATCHED MID
WEEK. THIS LOOKS TO BE MAINLY SOUTHEAST OF OF OUR AREA BUT THE
TRACKS OF PAST SYSTEMS THIS EARLY WINTER HAVE AFFECTED THE
SOUTHEAST HALF OF OUR FORECAST AREA...AND THE SAME MAY HOLD TUE
WITH THIS ONE.
&&
.AVIATION... /06Z TAF ISSUANCE/
VFR CONDITIONS OVER EASTERN AREAS WILL GRADUALLY GIVE WAY TO IFR
CONDITIONS OVER THE NEXT FEW HOURS AS LIGHT RAIN GRADUALLY SATURATES
LOWER LEVELS OF THE ATMOSPHERE. LIGHT RAIN/DRIZZLE TO CONTINUE INTO
THE EARLY MORNING BEFORE TAPERING AS INITIAL SURGE OF FORCING MOVES
THROUGH. WILL SEE INCREASING THREAT LIGHT RAIN DEVELOPING WED
AFTERNOON AS SURFACE FRONT AND UPPER TROUGH MOVES THROUGH. THIS
SLIDES EAST BY EARLY EVENING WITH PERHAPS SOME RAIN/SNOW CHANGING TO
SNOW OVER EASTERN AREAS THROUGH 06Z THU. WILL GRADUALLY LIFT
CEILINGS AND END PRECIPITATION FROM WEST TO EAST DURING THE NIGHT.
LIGHT SOUTHEAST WIND FLOW AHEAD OF FRONT...BECOMING NORTHWEST WITH
FROPA.
KMSP...VFR CIGS GRADUALLY LOWERING TO IFR THROUGH THE EARLY MORNING.
LIGHT RAIN SHOULD TAPER OR END AS DRIZZLE EARLY MORNING. AS UPPER
TROUGH AND SURFACE FRONT APPROACHES...INCREASING CHANCE OF LIGHT
RAIN DEVELOPING IN THE AFTERNOON/EARLY EVENING....PERHAPS ENDING AS
A LIGHT RAIN/SNOW MIX BEFORE 06Z THU.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/DWE
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
647 AM CST WED DEC 14 2011
.UPDATE...
UPDATED FOR THE 12Z AVIATION DISCUSSION BELOW.
.DISCUSSION...
A BIT OF A TRICKY FORECAST THIS MORNING WITH THE FIRST WAVE MOVING
THROUGH EAST CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN. RAIN
AND SNOW MIXED OCCURRING OVER PARTS OF CENTRAL MINNESOTA AND
WESTERN WISCONSIN. THE LATEST RUC AND VSREF PICKING UP ON THE LOW
LEVEL THICKNESS FIELDS AND MARGINAL 850 MB TEMPS AND IT COULD BE
ALL SNOW FOR A TIME EARLY. NOT MENTIONING MUCH ACCUMULATION AT
THIS POINT /LESS THAN AN INCH/ WITH MUCH OF THE FORCING MOVING
OUT. OTHERWISE WE WILL BE LEFT WITH MOST OF THE REMAINDER OF THE
MORNING WITH NOT REAL WIDESPREAD PRECIP...MOSTLY DRIZZLE.
FORTUNATELY...TEMPS MAINLY ABOVE 32 OR JUST AT 32 WHERE SOME SNOW
MOST ROAD TEMPS ON THE ARE NOT SUGGESTING A MAJOR THREAT FOR ICE.
MAY STILL INCLUDE A MENTION OF FREEZING DRIZZLE IN CENTRAL MN.
THE NAM AND GFS AND ARE GENERALLY IN LINE WITH BRINGING THE
SOUTHERN ROCKIES VORT NORTHEAST TOWARD IOWA WITH SIG FORCING
BRUSHING SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN DURING
THE AFTERNOON AND EVENING. THE TEMP STRUCTURE IS STILL INITIALLY
TOO WARM FOR MUCH SNOW BUT COOLING DOES TAKE PLACE AS THE 500 MB
HEIGHT FALLS TRACK ACROSS NORTHEAST IOWA. HAVE INDICATED NEAR AN
INCH OF SNOW FOR PARTS OF EAST CENTRAL MN AND WEST CENTRAL
WISCONSIN BUT WILL NEED TO WATCH THE TRENDS DURING THE DAY. THERE
IS CERTAINLY PLENTY OF MOISTURE WITH PWAT VALUES OVER 300 PERCENT
OF NORMAL THROUGH THE CENTRAL PLAINS.
BLUSTERY AND COLDER CONDITIONS MOVE IN FOR THURSDAY WITH COLD
ADVECTION KEEPING TEMP TRENDS STEADY FROM OVERNIGHT LOWS IN SOME
AREAS.
THE CLIPPER TYPE SYSTEM MOVING INTO THE AREA ON FRIDAY LOOKS
WELL DEFINED BUT LACKING MOISTURE. HAVE INTRODUCED AT LEAST A SLIGHT
CHANCE FOR LIGHT SNOW IN THE WEST BUT THERE MAY BE A NEED TO
EXPAND THAT IN LATER FORECASTS. SATURDAY LOOKS MILD BEHIND THAT
SYSTEM WITH DECENT CHANCE OF BRINGING SOME LOW 40S INTO THE
SOUTHWEST..EAST OF THE BUFFALO RIDGE.
ANOTHER SYSTEM IN THE SPLIT FLOW WILL NEED TO BE WATCHED MID
WEEK. THIS LOOKS TO BE MAINLY SOUTHEAST OF OF OUR AREA BUT THE
TRACKS OF PAST SYSTEMS THIS EARLY WINTER HAVE AFFECTED THE
SOUTHEAST HALF OF OUR FORECAST AREA...AND THE SAME MAY HOLD TUE
WITH THIS ONE.
&&
.AVIATION.../12Z TAF ISSUANCE/
WITH LIFR CEILINGS ALMOST EVERYWHERE...THE CLOUD BASE FORECAST IS
ACTUALLY NOT ALL THAT CHALLENGING FOR THE FIRST 6 HOURS. WITH THE
BROAD SURFACE TROF SETTLING IN AND A NICE FETCH OF MOISTURE FROM
THE SOUTHEAST...THESE CEILINGS AREN`T GOING ANYWHERE FOR MOST FOR
THE DAY. ITS POSSIBLE SOME SPOTS SEE THE DECK LIFT 200-400FT BY THIS
AFTERNOON...BUT SHOULD STILL REMAIN IFR. THE VISIBILITY FORECAST
IS MORE CHALLENGING GIVEN THE AREAS OF FOG AND DRIZZLE MIXED WITH
SCATTERED LIGHT RAIN SHOWERS. EVEN THOUGH IT FLIES IN THE FACE OF
CLIMATOLOGY...WORRIED THAT THE VISIBILITY MAY ACTUALLY GET WORSE
DURING A FEW HOUR WINDOW LATE THIS MORNING/THIS
AFTERNOON...ESPECIALLY IF THE RAIN HANGS TO OUR SOUTH FOR A WHILE.
WINDS SHOULD DECREASE UNDER THE TROF AND MAY GO CALM. PLENTY OF
1/4SM AND 1/2SM VISIBILITIES IN EASTERN SD AND WESTERN MN THIS
MORNING. BETTER CHANCES FOR LIGHT RAIN IN SOUTHEAST MN AND WESTERN
WI TODAY...WITH THE CHANGE OVER TO SNOW HAPPENING SOMETIME LATE
THIS EVENING.
KMSP...VISIBILITIES BELOW 2SM AND CEILINGS UNDER 500FT ARE NOT
GOING ANYWHERE FOR THE NEXT 6 HOURS. IN FACT...HAVE INCLUDED A
TEMPO GROUP FOR 1/2SM FOG EARLY THIS AFTERNOON WHEN WINDS DECREASE
AND MAY GO CALM FOR A TIME BEFORE TURNING TO THE WEST/NORTHWEST
LATE THIS EVENING. DON`T HAVE SUPREME CONFIDENCE WE`LL BUCK
CLIMATOLOGY AND SEE VISBYS DECREASE IN THE AFTERNOON...BUT THESE
ARE THE TYPES OF SITUATIONS WHEN IT DOES INDEED HAPPEN. THE WILD
CARD IS THE RAIN SHOWERS...WHICH WHEN PRESENT WOULD ACTUALLY KEEP
THE VISBYS FROM DROPPING TOO LOW. RIGHT NOW THE CHANGE OVER TO
SNOW TO ANY REMAINING PRECIPITATION WILL LIKELY SOMETIME AROUND
MIDNIGHT...WITH THE SURFACE AIR TEMPERATURE FALLING BELOW FREEZING
3-4 HOURS LATER.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/CLF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
720 AM CST WED DEC 14 2011
.UPDATE...DID A QUICK UPDATE TO DECREASE SKY COVER A TAD FOR LATE
MORNING/THIS AFTERNOON. LATEST RUC GUIDANCE INITIALIZED VERY WELL
BASED ON THE 12Z JAN RAOB...WITH THIS SAME GUIDANCE NOW MORE
SUGGESTIVE OF THE CLOUDS TRYING TO BREAK UP AFTER 1 PM. HIGH TEMPS
STILL LOOK GOOD THOUGH AND HAVENT MADE ANY ADJUSTMENTS...BUT THIS MAY
VERY WELL CHANGE ONCE THE EXTENT OF THE CLOUD COVER IS BETTER KNOWN
LATER THIS MORNING. /BK/
&&
.PREV DISCUSSION... /ISSUED 400 AM CST WED DEC 14 2011/
..DENSE FOG OCCURRING OVER PORTIONS OF THE ARKLAMISS THIS MORNING...
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...WIDESPREAD STRATUS
CONTINUES TO BLANKET THE ARKLAMISS THIS MORNING AS GENTLE MOIST
UPGLIDE OCCURS FROM THE SOUTHEAST. VISIBILITY RESTRICTIONS HAVE BEEN
A BIT EASIER TO COME BY TONIGHT AS OPPOSED TO LAST NIGHT...
ESPECIALLY ACROSS AREAS EAST OF I-55 AND ALONG THE HIGHWAY 82
CORRIDOR AND INTO SOUTHEAST AR. SURFACE OBSERVATIONS ACROSS THESE
AREAS SHOW FAIRLY WIDESPREAD RESTRICTIONS OF 1/2MI OR LESS AND WILL
GO WITH A DENSE FOG ADVISORY ACCORDINGLY...WHICH MEANT AN EXPANSION
OF THE CURRENT ADVISORY TO THE SOUTHEAST. LOOKING AT OBSERVATIONS
FROM YESTERDAY MORNING AND CLIMATOLOGY IT LOOKS LIKE THE VIS SHOULD
START COMING UP AFTER 9AM AND WILL END THE ADVISORY AT THAT TIME. A
SLOWLY INCREASING PRESSURE GRADIENT ACROSS SOUTHWESTERN ZONES
APPEARS TO BE LIMITING FOG POTENTIAL IN THIS AREA AS LATEST OBS FROM
HEZ/TVR/MCB/MLU INDICATE 5MI OR BETTER VIS. THE DENSE FOG ADVISORY
THAT WAS IN EFFECT FOR PORTIONS OF THIS AREA HAS BEEN CANCELLED AS A
RESULT. WILL KEEP A CLOSE ON THE FOG SITUATION THIS MORNING SO STAY
TUNED FOR UPDATES. WE MAY NEED TO EXPAND THE ADVISORY INTO THE
JACKSON METRO AT SOME POINT.
FOCUS THEN SHIFTS TO CLOUD COVER POTENTIAL THIS AFTERNOON AND HOW
THAT WILL IMPACT AFTERNOON HIGHS. LATEST RUC GUIDANCE IS NOT
CONFIDENT WE WILL SEE MUCH SUN THIS AFTERNOON AS LOW LEVEL MOISTURE
FIELDS REMAIN SATURATED FOR ALL BUT FAR EASTERN AREAS WHERE SOME
THINNING OF THE CLOUDS IS POSSIBLE. LATEST NAM/SREF INDICATE SOME
THINNING POSSIBLE NORTH OF I-20 THIS AFTERNOON REMAINING SOCKED IN
ELSEWHERE. OVERALL I LIKE WHAT THE RUC IS SHOWING AND HAVE
GENERALLY STUCK WITH CLOUDY SKIES TODAY FOR ALL AREAS...SHOWING A
FEW PEAKS OF SUN IN THE EAST THIS AFTERNOON. I DO HOWEVER THINK
THERE IS SOME POTENTIAL FOR A FEW BREAKS IN THE CLOUDS ACROSS THE
SOUTHWEST LATER ON AS THE LOW LEVEL FLOW PICKS UP IN RESPONSE TO A
PRESSURE GRADIENT THAT CONTINUES TO TIGHTEN. SO...WITH CLOUD COVER
REMAINING FAIRLY SOLID TODAY I HAVE GONE WITH THE LOWEST MEMBER OF
THE GFS MOS SUITE(MID TO UPPER 60S) FOR TEMPS TODAY...WHICH MIGHT
STILL BE TOO HIGH AS I THINK WE MIGHT STRUGGLE TO GET TO THE LOW 60S
ACROSS A BIG PORTION OF THE AREA.
TONIGHT INTO THURSDAY...A COLD FRONT WILL BE MOVING INTO SOUTH
CENTRAL AR LATE TONIGHT ATTENDANT TO A S/WV LIFTING ACROSS THE
CENTRAL PLAINS AND INTO THE GREAT LAKES REGION. LIGHT RAIN CHANCES
WILL BE ON THE INCREASE LATE TONIGHT/EARLY TOMORROW MORNING ACROSS
THE DELTA AS THIS FEATURE APPROACHES...WITH A FEW LIGHT NORTHWARD
MOVING SHOWERS AHEAD OF THE FRONT POSSIBLE ALONG/WEST OF THE MS
RIVER. THE FRONT WILL LIMP INTO MS LATE THURSDAY PUSHING SHOWER
CHANCES FURTHER SOUTHEAST AS IT ADVANCES. INSTABILITY IS RATHER WEAK
WITH THIS SYSTEM THANKS TO WARM MID/UPPER LEVEL TEMPS AND ASSOCIATED
WEAK LAPSE RATES. FORCING IS REAL WEAK AS WE REMAIN UNDER THE
INFLUENCE OF UPPER RIDGING ALOFT...ALL COMBINED I THINK THE
POTENTIAL FOR ANY STRONG TO SEVERE STORMS IS LOW THURSDAY. BUT...IF
THE INSTABILITY COMES IN A BIT HIGHER THAN FORECAST THERE COULD BE A
MARGINAL RISK OF 50MPH WIND GUSTS ACROSS THE FAR NORTHWEST EARLY TO
MID DAY THURSDAY. WILL GO AHEAD AND KEEP THAT MENTION IN THE HWO FOR
NOW. THE FRONT WILL STALL ACROSS CENTRAL PORTIONS OF THE FA THURSDAY
EVENING AS ANOTHER S/WV IN SOUTHWESTERLY FLOW LIFTS ACROSS THE
SOUTHERN PLAINS AND INTO THE MID MS VALLEY EARLY FRI. AS THIS BETTER
FORCING INTERACTS WITH THE FRONT WE COULD SEE A PERIOD OF MODERATE
RAIN THURSDAY NIGHT AS THE WAVE PASSES.
AS FOR TEMPS...LOWERED HIGHS FOR THURSDAY FOR MOST SITES AS CLOUD
COVER/RAIN POTENTIAL KEEP US FROM CLIMBING MUCH ABOVE
70...ESPECIALLY ACROSS THE DELTA WHERE WE PROBABLY WONT EVEN GET TO
70. OVERNIGHT LOWS SEEMED REASONABLE THIS PERIOD. /BK/
LONG TERM...FRIDAY THROUGH WEDNESDAY...TWO PERIODS OF RAIN ARE
EXPECTED IN THE LONG TERM. THIS FIRST IS FRIDAY AND THE SECOND IS
MONDAY NIGHT. COME FRIDAY MORNING A NEARLY STATIONARY COLD FRONT IS
EXPECTED TO BE ACROSS THE SOUTHEAST PORTION OF OUR CWA. THE NAM IS A
LITTLE FARTHER NORTH...BUT MODEL CONSENSUS PLACES THE FRONT FROM
SOUTH OF NATCHEZ TO JUST NORTH OF MERIDIAN AT SUNRISE. THERE IS
EXPECTED TO BE PLENTY OF POST FRONTAL PRECIPITATION ACROSS OUR CWA
AS A CLOSED LOW OVER THE DESERT SOUTHWEST DRAWS PACIFIC MOISTURE
ACROSS THE SOUTHERN PLAINS AND OUR REGION ON SOUTHWEST WINDS ALOFT.
A COUPLE OF NORTHERN STREAM SHORTWAVES WILL MOVE ACROSS THE PLAINS
FRIDAY AND SATURDAY AND HELP A +1030MB SURFACE HIGH DROP SOUTH TO
THE ARKLATEX REGION BY SATURDAY AFTERNOON. AS THIS HIGH DROPS SOUTH
THE NEARLY STATIONARY FRONT WILL BE PUSHED SOUTH OF OUR CWA AND THE
ASSOCIATED RAIN WILL END. THE BULK OF THE RAIN SHOULD END FROM THE
NORTH FRIDAY EVENING BUT A SLIGHT CHANCE OF RAIN WILL CONTINUE IN
THE SOUTH INTO SATURDAY MORNING. GUIDANCE POPS CAME IN A LITTLE HIGH
AND TOO FAR NORTH. HAVE CUT GUIDANCE POPS ACROSS OUR CWA SATURDAY
THROUGH SUNDAY. TEMPERATURES WILL BE WELL ABOVE NORMAL FRIDAY SOUTH
OF THE FRONT AND NEAR NORMAL NORTH OF THE FRONT. COOLER...BUT NEAR
NORMAL TEMPERATURES ARE EXPECTED SATURDAY. THE SURFACE HIGH WILL
BECOME CENTERED OVER OUR CWA SUNDAY MORNING AND CONTINUE SHIFTING
EAST DURING THE DAY. INDUCED RIDGING ALOFT WILL STRENGTHEN OVERHEAD
DUE TO THE CLOSED LOW MOVING JUST SOUTH OF THE FOUR CORNERS REGION.
THIS RIDGING SURFACE AND ALOFT SHOULD ALLOW TEMPERATURES TO RECOVER
NICELY SUNDAY AND TOP OUT ABOVE NORMAL AGAIN. HIGHS WILL BE IN THE
LOW TO MID 60S. RIDGING SURFACE AND ALOFT WILL SHIFT EAST MONDAY AS
THE CLOSED LOW MOVES TO THE SOUTHERN PLAINS. WAA WILL STRENGTHEN
OVER OUR CWA AHEAD OF THE APPROACHING SYSTEM LEADING TO RAIN CHANCES
INCREASING FROM THE WEST MONDAY. THE GFS AND ECMWF DISAGREE ON THE
PROGRESSION OF THE LOW MONDAY AND TUESDAY. THE GFS MAINTAINS THE
CLOSED LOW AND LIFTS THE BOTH THE UPPER LEVEL LOW AND SURFACE LOW
SLOWLY ACROSS THE OZARKS MONDAY NIGHT AND OVER THE TENNESSEE VALLEY
BY TUESDAY MORNING. THE MORE PROGRESSIVE ECMWF OPENS UP THE CLOSED
LOW AND MOVES BOTH THE UPPER LEVEL TROUGH AND SURFACE LOW TO THE
UPPER GREAT LAKES REGION BY TUESDAY MORNING. BOTH SCENARIOS BRING A
COLD FRONT WITH WIDESPREAD RAIN TO OUR CWA MONDAY NIGHT INTO TUESDAY
BUT THE GFS PARAMETERS SUGGEST THE POSSIBILITY FOR SEVERE WEATHER
MONDAY NIGHT FOR OUR CWA. WITH SUCH MODEL DISCREPANCIES WL HOLD OFF
INTRODUCING MENTION OF SEVERE WEATHER POTENTIAL IN THE HWO BUT LOOK
TO FUTURE RUNS FOR SOME CONTINUITY AND A MORE LIKELY CONSENSUS.
WEDNESDAY CURRENTLY LOOKS TO BE COOLER AND DRY FOR OUR REGION. /22/
&&
.AVIATION...
WDSPRD IFR CIG ARE PLAGUING THE REGION THIS
MORNING...ACCOMPANIED BY VRBL VSBYS RANGING FROM 1/4 TO 6SM. CIG
WILL LIKELY VARY BETWEEN 100 AND 800 FT UNTIL 17Z AT MOST SITES.
CLIMATOLOGY SUGGESTS CIG WILL TREND MVFR BY 18-19Z ALTHOUGH
CONFIDENCE IS LOW IN THIS BEING WDSPRD AS WE STRUGGLED TO LIFT MVFR
YESTERDAY. BEST CHANCE OF SEEING ANY SCT LOW CLOUDS WILL BE AT
MEI/HEZ THIS AFTN BUT THIS WILL PROB BE SHORT IF IT OCCURS AS IFR
CIG RETURN THIS EVENING. VIS WILL TREND MVFR 13-14Z BUT A TREND BACK
TOWARD IFR VSBY IS LIKELY TONIGHT. SFC WINDS WILL BE OUT OF THE SE
TODAY BECMG SRLY TONIGHT. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 68 59 72 57 / 0 13 48 82
MERIDIAN 70 54 74 59 / 0 10 37 74
VICKSBURG 69 60 71 52 / 1 22 69 84
HATTIESBURG 69 57 76 58 / 4 10 25 49
NATCHEZ 70 63 74 55 / 1 16 63 83
GREENVILLE 66 59 67 48 / 3 43 78 81
GREENWOOD 67 62 69 51 / 1 31 75 80
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MSZ018-019-
025>039-044>046-050>052-056>058-065-066-073-074.
LA...NONE.
AR...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR ARZ074-075.
&&
$$
BK/22
AREA FORECAST DISCUSSION
NWS JACKSON MS
400 AM CST WED DEC 14 2011
...DENSE FOG OCCURRING OVER PORTIONS OF THE ARKLAMISS THIS MORNING...
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT...WIDESPREAD STRATUS
CONTINUES TO BLANKET THE ARKLAMISS THIS MORNING AS GENTLE MOIST
UPGLIDE OCCURS FROM THE SOUTHEAST. VISIBILITY RESTRICTIONS HAVE BEEN
A BIT EASIER TO COME BY TONIGHT AS OPPOSED TO LAST NIGHT...
ESPECIALLY ACROSS AREAS EAST OF I-55 AND ALONG THE HIGHWAY 82
CORRIDOR AND INTO SOUTHEAST AR. SURFACE OBSERVATIONS ACROSS THESE
AREAS SHOW FAIRLY WIDESPREAD RESTRICTIONS OF 1/2MI OR LESS AND WILL
GO WITH A DENSE FOG ADVISORY ACCORDINGLY...WHICH MEANT AN EXPANSION
OF THE CURRENT ADVISORY TO THE SOUTHEAST. LOOKING AT OBSERVATIONS
FROM YESTERDAY MORNING AND CLIMATOLOGY IT LOOKS LIKE THE VIS SHOULD
START COMING UP AFTER 9AM AND WILL END THE ADVISORY AT THAT TIME. A
SLOWLY INCREASING PRESSURE GRADIENT ACROSS SOUTHWESTERN ZONES
APPEARS TO BE LIMITING FOG POTENTIAL IN THIS AREA AS LATEST OBS FROM
HEZ/TVR/MCB/MLU INDICATE 5MI OR BETTER VIS. THE DENSE FOG ADVISORY
THAT WAS IN EFFECT FOR PORTIONS OF THIS AREA HAS BEEN CANCELLED AS A
RESULT. WILL KEEP A CLOSE ON THE FOG SITUATION THIS MORNING SO STAY
TUNED FOR UPDATES. WE MAY NEED TO EXPAND THE ADVISORY INTO THE
JACKSON METRO AT SOME POINT.
FOCUS THEN SHIFTS TO CLOUD COVER POTENTIAL THIS AFTERNOON AND HOW
THAT WILL IMPACT AFTERNOON HIGHS. LATEST RUC GUIDANCE IS NOT
CONFIDENT WE WILL SEE MUCH SUN THIS AFTERNOON AS LOW LEVEL MOISTURE
FIELDS REMAIN SATURATED FOR ALL BUT FAR EASTERN AREAS WHERE SOME
THINNING OF THE CLOUDS IS POSSIBLE. LATEST NAM/SREF INDICATE SOME
THINNING POSSIBLE NORTH OF I-20 THIS AFTERNOON REMAINING SOCKED IN
ELSEWHERE. OVERALL I LIKE WHAT THE RUC IS SHOWING AND HAVE
GENERALLY STUCK WITH CLOUDY SKIES TODAY FOR ALL AREAS...SHOWING A
FEW PEAKS OF SUN IN THE EAST THIS AFTERNOON. I DO HOWEVER THINK
THERE IS SOME POTENTIAL FOR A FEW BREAKS IN THE CLOUDS ACROSS THE
SOUTHWEST LATER ON AS THE LOW LEVEL FLOW PICKS UP IN RESPONSE TO A
PRESSURE GRADIENT THAT CONTINUES TO TIGHTEN. SO...WITH CLOUD COVER
REMAINING FAIRLY SOLID TODAY I HAVE GONE WITH THE LOWEST MEMBER OF
THE GFS MOS SUITE(MID TO UPPER 60S) FOR TEMPS TODAY...WHICH MIGHT
STILL BE TOO HIGH AS I THINK WE MIGHT STRUGGLE TO GET TO THE LOW 60S
ACROSS A BIG PORTION OF THE AREA.
TONIGHT INTO THURSDAY...A COLD FRONT WILL BE MOVING INTO SOUTH
CENTRAL AR LATE TONIGHT ATTENDANT TO A S/WV LIFTING ACROSS THE
CENTRAL PLAINS AND INTO THE GREAT LAKES REGION. LIGHT RAIN CHANCES
WILL BE ON THE INCREASE LATE TONIGHT/EARLY TOMORROW MORNING ACROSS
THE DELTA AS THIS FEATURE APPROACHES...WITH A FEW LIGHT NORTHWARD
MOVING SHOWERS AHEAD OF THE FRONT POSSIBLE ALONG/WEST OF THE MS
RIVER. THE FRONT WILL LIMP INTO MS LATE THURSDAY PUSHING SHOWER
CHANCES FURTHER SOUTHEAST AS IT ADVANCES. INSTABILITY IS RATHER WEAK
WITH THIS SYSTEM THANKS TO WARM MID/UPPER LEVEL TEMPS AND ASSOCIATED
WEAK LAPSE RATES. FORCING IS REAL WEAK AS WE REMAIN UNDER THE
INFLUENCE OF UPPER RIDGING ALOFT...ALL COMBINED I THINK THE
POTENTIAL FOR ANY STRONG TO SEVERE STORMS IS LOW THURSDAY. BUT...IF
THE INSTABILITY COMES IN A BIT HIGHER THAN FORECAST THERE COULD BE A
MARGINAL RISK OF 50MPH WIND GUSTS ACROSS THE FAR NORTHWEST EARLY TO
MID DAY THURSDAY. WILL GO AHEAD AND KEEP THAT MENTION IN THE HWO FOR
NOW. THE FRONT WILL STALL ACROSS CENTRAL PORTIONS OF THE FA THURSDAY
EVENING AS ANOTHER S/WV IN SOUTHWESTERLY FLOW LIFTS ACROSS THE
SOUTHERN PLAINS AND INTO THE MID MS VALLEY EARLY FRI. AS THIS BETTER
FORCING INTERACTS WITH THE FRONT WE COULD SEE A PERIOD OF MODERATE
RAIN THURSDAY NIGHT AS THE WAVE PASSES.
AS FOR TEMPS...LOWERED HIGHS FOR THURSDAY FOR MOST SITES AS CLOUD
COVER/RAIN POTENTIAL KEEP US FROM CLIMBING MUCH ABOVE
70...ESPECIALLY ACROSS THE DELTA WHERE WE PROBABLY WONT EVEN GET TO
70. OVERNIGHT LOWS SEEMED REASONABLE THIS PERIOD. /BK/
.LONG TERM...FRIDAY THROUGH WEDNESDAY...TWO PERIODS OF RAIN ARE
EXPECTED IN THE LONG TERM. THIS FIRST IS FRIDAY AND THE SECOND IS
MONDAY NIGHT. COME FRIDAY MORNING A NEARLY STATIONARY COLD FRONT IS
EXPECTED TO BE ACROSS THE SOUTHEAST PORTION OF OUR CWA. THE NAM IS A
LITTLE FARTHER NORTH...BUT MODEL CONSENSUS PLACES THE FRONT FROM
SOUTH OF NATCHEZ TO JUST NORTH OF MERIDIAN AT SUNRISE. THERE IS
EXPECTED TO BE PLENTY OF POST FRONTAL PRECIPITATION ACROSS OUR CWA
AS A CLOSED LOW OVER THE DESERT SOUTHWEST DRAWS PACIFIC MOISTURE
ACROSS THE SOUTHERN PLAINS AND OUR REGION ON SOUTHWEST WINDS ALOFT.
A COUPLE OF NORTHERN STREAM SHORTWAVES WILL MOVE ACROSS THE PLAINS
FRIDAY AND SATURDAY AND HELP A +1030MB SURFACE HIGH DROP SOUTH TO
THE ARKLATEX REGION BY SATURDAY AFTERNOON. AS THIS HIGH DROPS SOUTH
THE NEARLY STATIONARY FRONT WILL BE PUSHED SOUTH OF OUR CWA AND THE
ASSOCIATED RAIN WILL END. THE BULK OF THE RAIN SHOULD END FROM THE
NORTH FRIDAY EVENING BUT A SLIGHT CHANCE OF RAIN WILL CONTINUE IN
THE SOUTH INTO SATURDAY MORNING. GUIDANCE POPS CAME IN A LITTLE HIGH
AND TOO FAR NORTH. HAVE CUT GUIDANCE POPS ACROSS OUR CWA SATURDAY
THROUGH SUNDAY. TEMPERATURES WILL BE WELL ABOVE NORMAL FRIDAY SOUTH
OF THE FRONT AND NEAR NORMAL NORTH OF THE FRONT. COOLER...BUT NEAR
NORMAL TEMPERATURES ARE EXPECTED SATURDAY. THE SURFACE HIGH WILL
BECOME CENTERED OVER OUR CWA SUNDAY MORNING AND CONTINUE SHIFTING
EAST DURING THE DAY. INDUCED RIDGING ALOFT WILL STRENGTHEN OVERHEAD
DUE TO THE CLOSED LOW MOVING JUST SOUTH OF THE FOUR CORNERS REGION.
THIS RIDGING SURFACE AND ALOFT SHOULD ALLOW TEMPERATURES TO RECOVER
NICELY SUNDAY AND TOP OUT ABOVE NORMAL AGAIN. HIGHS WILL BE IN THE
LOW TO MID 60S. RIDGING SURFACE AND ALOFT WILL SHIFT EAST MONDAY AS
THE CLOSED LOW MOVES TO THE SOUTHERN PLAINS. WAA WILL STRENGTHEN
OVER OUR CWA AHEAD OF THE APPROACHING SYSTEM LEADING TO RAIN CHANCES
INCREASING FROM THE WEST MONDAY. THE GFS AND ECMWF DISAGREE ON THE
PROGRESSION OF THE LOW MONDAY AND TUESDAY. THE GFS MAINTAINS THE
CLOSED LOW AND LIFTS THE BOTH THE UPPER LEVEL LOW AND SURFACE LOW
SLOWLY ACROSS THE OZARKS MONDAY NIGHT AND OVER THE TENNESSEE VALLEY
BY TUESDAY MORNING. THE MORE PROGRESSIVE ECMWF OPENS UP THE CLOSED
LOW AND MOVES BOTH THE UPPER LEVEL TROUGH AND SURFACE LOW TO THE
UPPER GREAT LAKES REGION BY TUESDAY MORNING. BOTH SCENARIOS BRING A
COLD FRONT WITH WIDESPREAD RAIN TO OUR CWA MONDAY NIGHT INTO TUESDAY
BUT THE GFS PARAMETERS SUGGEST THE POSSIBILITY FOR SEVERE WEATHER
MONDAY NIGHT FOR OUR CWA. WITH SUCH MODEL DISCREPANCIES WL HOLD OFF
INTRODUCING MENTION OF SEVERE WEATHER POTENTIAL IN THE HWO BUT LOOK
TO FUTURE RUNS FOR SOME CONTINUITY AND A MORE LIKELY CONSENSUS.
WEDNESDAY CURRENTLY LOOKS TO BE COOLER AND DRY FOR OUR REGION. /22/
&&
.AVIATION...WDSPRD IFR CIG ARE PLAGUING THE REGION THIS
MORNING...ACCOMPANIED BY VRBL VSBYS RANGING FROM 1/4 TO 6SM. CIG
WILL LIKELY VARY BETWEEN 100 AND 800 FT UNTIL 17Z AT MOST SITES.
CLIMATOLOGY SUGGESTS CIG WILL TREND MVFR BY 18-19Z ALTHOUGH
CONFIDENCE IS LOW IN THIS BEING WDSPRD AS WE STRUGGLED TO LIFT MVFR
YESTERDAY. BEST CHANCE OF SEEING ANY SCT LOW CLOUDS WILL BE AT
MEI/HEZ THIS AFTN BUT THIS WILL PROB BE SHORT IF IT OCCURS AS IFR
CIG RETURN THIS EVENING. VIS WILL TREND MVFR 13-14Z BUT A TREND BACK
TOWARD IFR VSBY IS LIKELY TONIGHT. SFC WINDS WILL BE OUT OF THE SE
TODAY BECMG SRLY TONIGHT. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 68 59 72 57 / 0 13 48 82
MERIDIAN 70 54 74 59 / 0 10 37 74
VICKSBURG 69 60 71 52 / 1 22 69 84
HATTIESBURG 69 57 76 58 / 4 10 25 49
NATCHEZ 70 63 74 55 / 1 16 63 83
GREENVILLE 66 59 67 48 / 3 43 78 81
GREENWOOD 67 62 69 51 / 1 31 75 80
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MSZ018-019-
025>039-044>046-050>052-056>058-065-066-073-074.
LA...NONE.
AR...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR ARZ074-075.
&&
$$
BK/22/BK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
934 AM EST WED DEC 14 2011
.SYNOPSIS...
A WEAK WARM FRONT LIFTS TO OUR NORTH TODAY. A COLD FRONT CROSSES
THURSDAY EVENING. DEEPER MOISTURE MAY KINK BACK NORTH AND BRUSH
AREA ON FRIDAY. DRY WITH HIGH PRESSURE FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
BASED ON LATEST RADAR TRENDS AND THE HRRR MODEL...HAVE UPDATED
POPS. MEASURABLE PRECIPITATION WAS MUCH FARTHER SOUTH THAN
PREVIOUSLY EXPECTED. HOWEVER...HRRR MODEL INDICATES THE AREA OF
SHOWERS SHOULD PUSH NORTH OF AREA THIS AFTERNOON.
WILL LIKELY TWEAK SKY GRIDS DOWNWARD AS VISIBLE IMAGERY SHOWS
ABUNDANT SUNSHINE TO OUR SOUTHWEST. CURRENT TEMPS ARE COOLER THAN
FORECASTED...SO WILL TWEAK DOWNWARD DOWNWARD. HOWEVER...STILL FEEL
FORECASTED HIGHS ARE REACHABLE...AND WILL NOT CHANGE.
PREVIOUS DISCUSSION...
ILL-DEFINED WARM FRONT SOMEWHERE NEAR THE JUNCTION OF THE
MISSISSIPPI AND OHIO RIVERS EARLY THIS MORNING MOVES NE THROUGH
THE FORECAST AREA THIS AFTERNOON. WARM ADVECTION RAIN OUT AHEAD OF
THE FRONT ENCOMPASSING MUCH OF THE OHIO VALLEY NORTH OF THE RIVER
EARLY THIS MORNING WILL STAY MAINLY ON THAT SIDE OF THE RIVER AS
IT IMPACTS OUR SE OHO COUNTIES...BLEEDING INTO NORTHERN WV BEFORE
LIFTING N THIS AFTERNOON.
AREA WILL THEN BE ENTIRELY IN WARM SECTOR BY LATE TODAY AND REMAIN
SO THROUGH TONIGHT. TIGHTENING GRADIENT SPELLS INCREASING WINDS
TONIGHT ESPECIALLY ON THE RIDGES. MODELS IN GOOD AGREEMENT ON
TIMING OF COLD FRONT APPROACHING FROM THE W...WITH SHOWERS AHEAD OF
THE FRONT REACHING NEAR THE OHIO RIVER BY 12Z THU.
HIGHS TODAY LOOKED GOOD...CLOSE TO ADJMETBC.,,WITH LITTLE CHANGE
NEEDED. BLENDED IN ADJMET FOR LOWS TONIGHT WHICH ALSO ENTAILED ONLY
SMALL CHANGES. DID WARM THE RIDGE AND HILLTOPS A BIT OVERNIGHT AS
SW WINDS INCREASE THERE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
NO MAJOR CHANGES NEEDED TO THE SHORT TERM PERIOD. COLD FRONT WILL
MOVE INTO THE CWA AT THE BEGINNING OF THE PERIOD...SPREADING SHOWERS
FROM WEST TO EAST WITH IT. THIS IS A RATHER MOIST SYSTEM...WITH PW
VALUES EXPECTED TO CLIMB INTO THE 1.1 TO 1.3 RANGE...AIDED BY 50+KT
LLJ. STILL NOT EXPECTING ANY WATER ISSUES WITH THIS SYSTEM HOWEVER
DUE TO ITS OVERALL PROGRESSIVE NATURE...AND STILL FIGURING GENERALLY
ABOUT 0.5 TO 0.75 INCHES QPF. WITH THE GOOD SOUTHERLY FLOW EXPECTED
OUT AHEAD OF THE APPROACHING COLD FRONT...MAX TEMPERATURES ON
THURSDAY ARE EXPECTED TO CLIMB WELL ABOVE NORMAL...WITH ALL OF THE
CWA EXPECTED TO CLIMB INTO THE 50S TO LOWER 60S. WITH THE WARM AIR
IN PLACE...SHOULD SEE A MAINLY RAIN EVENT...EXCEPT FOR THE
POSSIBILITY OF SOME LIGHT RAIN/SNOW OR SNOW SHOWERS IN THE NORTHERN
MOUNTAIN ZONES FRIDAY MORNING BEHIND THE FRONT. HOWEVER...THIS WILL
DEPEND ON A VARIETY OF FACTORS INCLUDING AMOUNT OF ATMOSPHERIC
MOISTURE REMAINING AND HOW MUCH COLD AIR IS ACTUALLY IN PLACE.
REGARDLESS...ACCUMULATIONS DO NOT LOOK FAVORABLE.
FRONTAL BOUNDARY WILL EXIT TO THE SOUTH ON FRIDAY WITH ANOTHER WAVE
RIDING ALONG THE FRONT FROM THE SOUTH FRIDAY THROUGH FRIDAY NIGHT.
THIS WILL MAINLY AFFECT THE SOUTHERN AND EASTERN ZONES. RECENT RUN
OF THE NAM APPEARS TO KEEP MOISTURE ASSOCIATED WITH THIS FEATURE
FARTHER TO THE SOUTH THAN THE GFS OR ECMWF...AND IF THIS SCENARIO
TURNS OUT...WILL MAINLY AFFECT SOUTHWEST VA AND EXTREME SOUTHERN
COAL FIELDS. GFS AND ECMWF OVERSPREAD MOISTURE FARTHER NORTH INTO
THE AREA...AS FAR NORTH AS CRW. FOR NOW...KEPT ONLY CHANCE TO SLIGHT
CHANCE POPS TO THE NORTH...WITH LIKELY OVER SOUTHWEST VA AND
SOUTHERN COAL FIELDS DUE TO UNCERTAINTY. IF MOISTURE IS ABLE TO
SPREAD FARTHER NORTH...AND DEPENDING ON THE EXACT TRACK OF THE
WAVE...COULD SEE SOME LIGHT SNOW IN THE NORTHERN MOUNTAIN ZONES
FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
SFC HIGH BUILDS IN OVER THE WEEKEND TO PROVIDE FOR DRY AND
SEASONABLE CONDITIONS...ALBEIT ON THE COLD SIDE FOR LOW TEMPS. NEXT
SYS SLATED FOR MON NIGHT AND TUES AS SW LOW EJECTS NE TOWARD THE
AREA...INCREASING THE CHANCES FOR RAIN.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
WARM FRONT WILL BE THE MAIN WEATHER MAKER THIS PERIOD...WITH ITS
PASSAGE DURING THE DAY ON WED.
PATCHY MVFR STRATOCU MAINLY NEAR OHIO RIVER AS THE WARM FRONT
APPROACHES. LIGHT RAIN ASSOCIATED WITH THE FRONT AFFECTING EASTERN
OHIO INTO NORTHERN WV THIS MORNING WITH NO APPRECIABLE VSBY
RESTRICTIONS. THE RAIN WHICH WILL MOVE N OF THE AREA THROUGH LATE
MORNING.
CIGS WILL LIFT FROM S TO N...FOLLOWED BY CLEARING...AS THE FRONT
MOVES N THROUGH THE AREA THIS AFTERNOON. EXPECT VFR AREA WIDE BY
THIS EVENING IN THE WARM SECTOR. SHOWERS ASSOCIATED WITH A COLD
FRONT APPROACHING FROM THE W WILL REACH THE OHIO RIVER AROUND 12Z
THU. MVFR AND WORSE CONDITIONS SHOULD HOLD OFF UNTIL AFTER 12Z.
LIGHT AND VARIABLE WINDS THIS MORNING WILL STRENGTHEN A BIT FROM THE
S DURING THE DAY TODAY...AND MAY NOT DIMINISH MUCH TONIGHT. WINDS
TONIGHT WILL ACTUALLY STRENGTHEN ON THE RIDGES...AS LIGHT W WINDS
ALOFT THIS MORNING BACK TO SW BY WED EVENING AND BECOME STRONG THIS
EVENING AND REMAIN STRONG OVERNIGHT. WIND SHEAR TOWARD THU MORNING
COULD APPROACH LLWS CRITERIA OF 20KTS/200FT WITHIN 2KFT AGL.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF THE MVFR CIGS THIS MORNING
COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY M H H H H H H H H H H H
HTS CONSISTENCY M H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L L L L L H H H H H
PKB CONSISTENCY M M M M H H H H H H H H
CKB CONSISTENCY H H M L H H H H H H H H
AFTER 12Z THURSDAY...
IFR POSSIBLE IN RAIN SHOWERS WITH COLD FRONT THURSDAY INTO THURSDAY
NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...JSH/TRM
SHORT TERM...SL
LONG TERM...30
AVIATION...TRM
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
941 AM CST WED DEC 14 2011
.UPDATE...
ELONGATED TROF AXIS PERSISTS FROM THE CENTRAL PLAINS BACK INTO THE
SOUTHWEST US WITH ONE SIGNIFICANT PIECE OF ENERGY EJECTING
NORTHEAST THIS MORNING. THIS S/W WILL HELP PUSH A PACIFIC FRONT
THROUGH THE REGION THIS AFTERNOON. REGIONAL RADAR IMAGERY ALREADY
SHOWS A BROKEN LINE OF PRIMARILY SHOWERS DEVELOPING TO THE
NORTHWEST OF THE CWA. THIS IS EXPECTED TO GRADUALLY FILL IN AND
MOVE EAST THROUGH THE DAY AS THE FRONT GAINS MOMENTUM. ALL OF THE
HIGH RESOLUTION SHORT TERM GUIDANCE SUGGESTS THAT A LINE OF
CONVECTION WILL MOVE THROUGH NORTH TEXAS THROUGH THIS AFTERNOON
ALONG THE FRONT...HOWEVER THERE IS SOME DISCREPANCY AS TO HOW
INTENSE IT WILL BE. LATEST NAM IS MOST AGGRESSIVE WITH INSTABILITY
AND STILL INDICATES AN AXIS OF 700-1000J/KG OF OF CAPE ACROSS
NORTH TEXAS AND WEAKENS THE CAPPING AROUND 700MB. RUC SOUNDINGS
ARE NOT SO QUICK TO ERODE THE CAPPING AND INDICATE THAT DEEP
CONVECTION WILL BE HARD TO COME BY. GIVEN THE EXTENSIVE CLOUD
COVER AND ONGOING DRIZZLE TEND TO THINK THE LESS AGGRESSIVE RUC
MAY HAVE A BETTER HANDLE ON THINGS. WILL CONTINUE TO MENTION
THUNDERSTORMS THROUGH THE AFTERNOON...BUT OVERALL SEVERE WEATHER
THREAT MAY BE CONFINED TO A FEW ISOLATED CELLS. THIS IS ONE OF
THOSE SITUATIONS THOUGH WHERE A LITTLE EXTRA HEATING OR SLIGHTLY
MORE WEAKENING OF THE CAP COULD RESULT IN MORE WIDESPREAD SEVERE
CONVECTION SO IT IS WORTH WATCHING THROUGH THE AFTERNOON. ONLY
SOME MINOR TWEAKS TO POP/WEATHER WORDING THROUGH THE AFTERNOON
OTHERWISE NO MAJOR CHANGES TO THE CURRENT FORECAST.
DUNN
&&
.AVIATION...
.CONCERNS...
MANY CHALLENGES WITH CIGS/VSBY AND TIMING OF SURFACE TROUGH AND
ASSOCIATED TSRA/CB THIS AFTERNOON. COLD FRONT TIMING A LITTLE
TRICKY THURSDAY MORNING.
CURRENT REGIONAL RADAR AND AREA WX OBSERVATIONS INDICATE LIFT IS
INCREASING ACROSS NORTHWEST TX/WRN OK THIS MORNING WITH SHRA/-RA
BECOMING WIDESPREAD FROM KSPS TO KCDS/KOKC. GUSTY SE WINDS 13-23KTS
ARE ASSISTING IN THE PRODUCTION OF SPOTTY -RA/-DZ AND IFR STRATUS.
WHERE HEAVIER DZ OCCURS...CIGS ARE FALLING INTO LIFR CATEGORY
BETWEEN 003-005 KFT. WILL HAVE A TEMPO GROUP FOR THIS POSSIBILITY
THROUGH MID MORNING AT ALL TERMINALS.
INCREASING LIFT THIS AFTERNOON WILL COMBINE WITH LOW LEVEL WARMING
/GUSTY SOUTH WINDS TO LIFT CIGS BACK INTO THE MVFR...OR POSSIBLY A
LOW VFR CATEGORY BY 21Z. BEST GUESS WINDOW FOR TSRA AT DFW
TERMINALS WILL BE 20-22Z AND 22Z-00Z AT WACO. -SHRA/-RA LIKELY
WILL LINGER THROUGH MID EVENING.
WINDS GRADUALLY SHIFT SOUTHWEST AND DECREASE TO 5-10 KTS AFTER
PASSAGE OF SURFACE TROUGH LATE THIS AFTERNOON...THEN BECOME NORTHWEST
AROUND 10 KTS EARLY THURSDAY MORNING WITH THE COLD FRONT MOVING
THROUGH THE AREA.
05/
&&
.PREV DISCUSSION... /ISSUED 344 AM CST WED DEC 14 2011/
MOIST ISENTROPIC ASCENT WILL CONTINUE TODAY AS THE LOW LEVEL JET
REMAINS STRONG AND CONTINUES TO TRANSPORT RICH MOISTURE INTO THE
REGION. SOME INSTABILITY WILL WORK INTO THE WESTERN COUNTIES THIS
MORNING AND THEN SPREAD EASTWARD THIS AFTERNOON AND EVENING. THERE
IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WITH HAIL AND DAMAGING
WINDS DUE TO AN APPROACHING SHORTWAVE...A 90-100 KNOT JET ALOFT AND
400-1000 J/KG OF CAPE. BEST TIMING FOR SEVERE WILL BE MID/LATE
AFTERNOON OVER THE WESTERN HALF AND THIS EVENING FOR THE EASTERN
HALF. A COLD FRONT WILL SWING THROUGH NORTH TEXAS LATER TONIGHT
AND BRING COOLER NORTHERLY WINDS BACK TO THE REGION.
A STRONG SHORTWAVE WILL KICK OUT OF THE PERSISTENT SOUTHERN
CALIFORNIA UPPER LOW AND PASS OVER THE REGION THURSDAY EVENING.
HAVE HELD ONTO LOW POPS THURSDAY AND THURSDAY NIGHT AS MID LEVEL
LIFT MOVES ACROSS THE REGION. AS THE SHORTWAVE MIGRATES EAST OF THE
REGION...RAIN CHANCES WILL END FOR MOST OF THE CWA BUT LINGER
OVER THE SOUTHERN COUNTIES THROUGH FRIDAY. THERE WILL BE A BRIEF
LULL IN RAIN CHANCES ON SATURDAY...BUT THEY RETURN TO THE WESTERN
COUNTIES SATURDAY NIGHT AS THE MAIN UPPER LOW OVER SOUTHERN
CALIFORNIA BEGINS TO MOVE EAST. AS THE UPPER SYSTEM NEARS TEXAS...
RAIN CHANCES WILL INCREASE WEST TO EAST SUNDAY THROUGH
MONDAY...AND HAVE INCLUDED THUNDERSTORM POTENTIAL FOR MONDAY
MORNING. ANOTHER COLD FRONT WILL MOVE THROUGH THE REGION MONDAY
EVENING.
TEMPERATURES FOR THE MOST PART WILL BE SEASONAL WITH ABOVE NORMAL
CONDITIONS AHEAD OF TONIGHT/S COLD FRONT AND MONDAY/S COLD FRONT.
75
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 72 50 58 39 53 / 100 50 30 40 10
WACO, TX 74 50 57 43 54 / 80 50 40 60 10
PARIS, TX 72 53 64 42 53 / 80 70 30 50 10
DENTON, TX 69 46 58 36 51 / 100 40 30 30 10
MCKINNEY, TX 69 49 60 40 52 / 100 50 30 40 10
DALLAS, TX 71 51 58 40 54 / 100 50 40 40 10
TERRELL, TX 70 53 61 42 55 / 90 60 40 50 10
CORSICANA, TX 72 55 59 45 55 / 70 60 40 60 10
TEMPLE, TX 73 53 58 43 56 / 60 50 50 60 20
MINERAL WELLS, TX 71 43 55 34 51 / 100 20 30 30 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER CO
1045 AM MST WED DEC 14 2011
.UPDATE...
&&
.SHORT TERM...NO CHANGES OF NOTES TO THE ZONES...MAY TWEAK SOME
WINDS FOR TODAY IN THE GRIDS. WEAK SURGE CAME ACROSS PLAINS THIS
MORNING BEHIND SYSTEM MOVING WELL TO OUR EAST BUT WIND DIRECTIONS
QUITE TRICKY NEAR THE FRONT RANGE WITH THE NW FLOW MAINLY FARTHER
OUT ON THE PLAINS AND IN AND NEAR THE FOOTHILLS RIGHT NOW. BUT
ENOUGH SUN AND MIXING TO GEET MOST TEMPERATURES INTO THE 40S THIS
AFTERNOON. A WEAK WAVE MOVING ACROSS WYOMING RIGHT NOW BUT THIS IS
WEAKENING WITH TIME AND LOOKS LIKE THE MAIN THING WITH THIS COULD
BE SOME INCREASE IN SNOW SHOWERS IN THE MOUNTAINS TONIGHT SO WILL
ASSESS THIS. PERSISTENCE THOUGH WOULD SUGGEST NOT A LOT WITH THIS
WAVE UNFORTUNATELY AND PLAINS LOOK DRY.
.AVIATION...TRICKY PART IS WINDS. AT DIA QUITE UNCERTAIN ABOUT
THEM EVER GOING NW AND INSTEAD BASED ON HRRR AND WRF SHORT RANGE
MODEL RUNS BROUGHT A WEAKISH NORTHERLY TO NE SHIFT IN THIS
AFTERNOON. THEN COMES AROUND TO SE THIS EVENING BEFORE DRAINAGE
SETS IN. APPEARS TO BE GOOD CHANCE OF A DENVER CYCLONE THURSDAY
AND PLAYED WINDS THAT WAY. BJC COULD HOWEVER SEE SOME W TO NW FLOW
INCREASE ALTHOUGH FOR NOW STAYING NEAR THE FOOTHILLS SO TRICKY
THERE AS WELL.
&&
.PREV DISCUSSION... /ISSUED 318 AM MST WED DEC 14 2011/
SHORT TERM...UPPER TROUGH AXIS CURRENTLY OVER WESTERN COLORADO AS
DEPICTED IN SATELLITE AND RADAR. SNOW IS INCREASING OVER THE HIGH
COUNTRY AS UPPER FLOW TRANSITIONS FROM SOUTHWEST TO NORTHWEST AND
LIFT INCREASES. NOT TOO MUCH MOISTURE LEFT WITH THIS SYSTEM THEN A
SHORTWAVE CURRENTLY OVER IDAHO WILL MOVE SOUTHEAST TO BRING A
LITTLE MORE SNOW THROUGH THE DAY AND TONIGHT. ALL TOGETHER
THOUGH...ONLY A FEW INCHES AT MOST THROUGH THE DAY. TEMPERATURES
TODAY WILL BE ABOUT 10 DEGREES LESS THAN YESTERDAY AS COLDER AIR
SPREADS OVER COLORADO BEHIND THE UPPER TROUGH. WESTERLY SURFACE
WINDS WILL ALSO BE INCREASING BEHIND THE TROUGH THROUGH THE DAY AS
THE LOW PRESSURE MOVES EAST. WILL SEE GUSTY WINDS IN THE FOOTHILLS
THIS AFTERNOON WITH SPEEDS OF 20 TO 35 MPH WITH GUSTS TO 45 MPH
POSSIBLE.
THE FOG OVER THE PLAINS CONTINUES TO PUSH SLIGHTLY EAST AS DRIER AIR
MOVES IN FROM THE WEST. KEEPING IN THE SLIGHT CHANCE OF LIGHT SNOW
OVER THE FAR EASTERN PLAINS AS THE AREA OF LIFT PASSES OVERHEAD THIS
MORNING. AS THE SYSTEM PUSHES EAST AND CLOUDS CLEAR...SOME SUN AND
THE MIXING FROM THE APPROACHING COLDER AIR FROM THE NORTH WILL ALLOW
ANY INVERSIONS OVER THE PLAINS TO BREAK AND ALLOW TEMPERATURES TO
WARM OVER YESTERDAYS READINGS. THE GUSTY WEST WINDS NEAR THE
FOOTHILLS WILL LET TEMPERATURES WARM A LITTLE MORE THERE...ALREADY
THIS MORNING THE NCAR MESA LAB HAS WARMED INTO THE UPPER 30S WITH
WEST WINDS WHILE JUST A SHORT DISTANCE AWAY TO ERIE ITS IN THE MID
TEENS. WEST TO NORTHWEST SURFACE WINDS ARE EXPECTED TO SPREAD OVER
THE PLAINS TODAY WITH CLEARING SKIES. WILL LIKELY SEE COLDER MINIMUM
TEMPERATURES TONIGHT WITH THE CLEAR SKIES AND COLDER AIRMASS FROM
THE NORTH.
LONG TERM...UPPER LEVEL RIDGE WILL BUILD OVER COLORADO ON THURSDAY
AS NEXT UPPER LEVEL LOW DRIVES SOUTHWARD ALONG THE WEST COAST. THIS
WILL RESULT IN MOSTLY SUNNY SKIES. HOWEVER...LACK OF DOWNSLOPE FLOW
ALONG WITH REMAINING SNOW COVER SHOULD KEEP HIGH TEMPS A COUPLE
DEGREES BELOW NORMAL.
ON FRIDAY...A SHORT WAVE MOVING ACROSS THE NORTHERN PLAINS STATES
WILL PUSH ANOTHER WEAK COLD FRONT ACROSS NORTHEAST COLORADO. THIS
SHOULD DROP TEMPS A COUPLE DEGREES FROM THURSDAYS HIGHS. NO
PRECIPITATION IS EXPECTED EVEN IN THE MOUNTAINS AS A GENERALLY DRY
AND SUBSIDENT AIRMASS WILL PREVAIL IN BETWEEN THE NORTHERN PLAINS
SHORT WAVE AND THE STRONGER UPPER LOW SPINNING NEAR THE COLORADO
RIVER DELTA/NORTHERN BAJA. IN FACT...IT SHOULD BE ANOTHER MOSTLY
SUNNY DAY.
LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED SATURDAY INTO EARLY
SUNDAY. HOWEVER...TEMPERATURES WILL TURN WARMER WITH SOME
MODERATION IN THE AIRMASS.
BY LATE SUNDAY AND MONDAY THE UPPER LOW OVER THE FAR SOUTHWEST IS
EXPECTED TO GRADUALLY KICK EAST/NORTHEAST AS A WEAK UPSTREAM KICKER
MOVES INTO THE PACIFIC NORTHWEST. THE CHANCE OF ANY PRECIPITATION
AT THIS POINT LOOKS QUITE SLIM WITH THE MAIN TROUGH BEING TOO FAR
SOUTH. THE NORTHERN SYSTEM WILL ALSO BE QUITE WEAK...SO ANY MENTION
OF SNOW IN THE FORECAST WILL BE LIMITED TO THE MOUNTAINS FOR NOW.
AVIATION...VFR CONDITIONS TO PREVAIL THROUGH THURSDAY MORNING. LOW
CLOUDS AND FOG ARE EXPECTED TO REMAIN EAST OF THE DENVER AREA
AIRPORTS. LIGHT DRAINAGE WINDS WILL CONTINUE EARLY THIS MORNING
TRANSITIONING TO WEST AND NORTHWEST WINDS MIDMORNING...INCREASING
AFTER 15Z AS DOWNSLOPE WINDS PREVAIL. CEILINGS TO REMAIN ABOVE 10000
FEET AGL THROUGH THE DAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SZOKE
LONG TERM....99
AVIATION...SZOKE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
238 PM CST WED DEC 14 2011
.DISCUSSION...
ISSUED 238 PM CST WED DEC 14 2011
SPRING-LIKE STORM SYSTEM BRINGING SHOWERS AND SCATTERED
THUNDERSTORMS TO THE CENTRAL/NORTHERN CWA TODAY IN BROAD...WARM
SOUTHWEST FLOW. HEAVIEST RAINS OF 1.5-2.5 INCHES HAVE FALLEN NORTH
OF A BEARDSTOWN TO BLOOMINGTON LINE. MODERATE RAINFALL RATES AND
UNFROZEN GROUND HAVE PRODUCED LITTLE IN THE WAY OF WATER PROBLEMS.
UPPER LEVEL DYNAMICS HELPING DRIVE THIS ACTIVITY AS SFC LOW AND
FRONT ANALYZED AT 19Z ACROSS EASTERN NEB/NRN KS. EVEN WITH THICK
CLOUDS AND RAIN...EARLY AFTERNOON TEMPS WERE RUNNING 15-20 DEGREES
ABOVE NORMAL. SHORT TERM FORECAST ISSUE IS ENDING OF RAIN WITH
COLD FRONTAL PASSAGE LATE TONIGHT AND RETURN TO SEASONABLE TEMPS.
BEYOND...NEXT MAJOR SYSTEM LOOKS TO IMPACT REGION EARLY NEXT WEEK.
SHORT TERM...TONIGHT THROUGH THURSDAY
UNSEASONABLY HIGH P/W VALUES AROUND 1.25 INCHES AND STRONG FORCING
ALOFT WILL CONTINUE TO DRIVE MODERATE RAIN AND EMBEDDED
THUNDERSTORMS THIS EVENING. LATEST HIGH RES NAM AND HRRR RUNS SHOW
ROUNDS OF CONVECTION TRANSLATING EAST ACROSS THE CWA THROUGH LATE
EVENING. PLENTY OF ELEVATED INSTABILITY FOR THUNDER...AND VERY
STRONG LLJ OVERHEAD /1 KM AGL WINDS 50 KTS/ BUT DUE TO STRONG LOW
LEVEL INVERSION DO NOT EXPECT ANY OF THIS TO MAKE IT DOWN TO THE
SURFACE. MAIN BATCH OF RAIN ASSOCIATED WITH PRE-FRONTAL TROUGH
LOOKS TO PUSH INTO INDIANA AFTER MIDNIGHT...WHEN THE ACTUAL COLD
FRONT ENTERS THE NW CWA. EXPECT A LINE OF SCATTERED SHOWERS
ALONG/AHEAD OF THE FRONT...WHICH WILL EXIT THE SE CWA AROUND 15Z
THU. BRISK WEST WINDS GUSTING TO 20-25 MPH WILL MOVE IN BEHIND THE
FRONT...BRINGING IN COOLER AND DRIER AIR.
CLOUD FORECAST FOR THURSDAY IS PROBLEMATIC WITH DRY AIR ADVECTING
IN...BUT FCST SOUNDINGS SHOW A SHALLOW LAYER OF MOISTURE TRAPPED
BENEATH A SHARP SUBSIDENCE INVERSION AROUND 925 MB. THIS COMBINED
WITH CYCLONIC FLOW ALOFT AND WEAK SUN ANGLE MAKES A LOW STRATUS
DECK LOOK LIKELY TO HOLD AT LEAST INTO MID AFTERNOON. TEMPERATURES
MAY HOLD STEADY FOR A FEW HOURS IN THE MORNING...THEN SLOWLY FALL
THROUGH THE AFTERNOON WHEN STRONGER CAA KICKS IN.
LONG TERM...FRIDAY THROUGH WEDNESDAY
QUIET AND SEASONABLE WEATHER IS ON TAP FOR THE FRIDAY INTO SUNDAY
PERIOD. ZONAL/WNW FLOW ALOFT AND HIGH PRESSURE AT THE SURFACE WILL
BE RESPONSIBLE FOR THE TRANQUIL CONDITIONS. AS THE HIGH SHIFTS OFF
TO THE SOUTHEAST LATE IN THE WEEKEND SOUTHERLY FLOW DEVELOPS AHEAD
OF THE NEXT SYSTEM IN THE SW.
CURRENT INDICATIONS SHOW THIS EVENT MAY BE SIMILAR TO THE STORM
THAT IS CURRENTLY IMPACTING THE AREA. THE 12Z ECMWF AND CANADIAN GEM
ARE SIMILAR IN TRACKING A STRONG LOW FROM THE TX PANHANDLE REGION
MONDAY MORNING...INTO THE LOWER GREAT LAKES BY TUESDAY EVENING.
12Z GFS IS MUCH SLOWER AND FARTHER SOUTH AND WAS NOT FOLLOWED FOR
THIS FORECAST. EVENTUAL LOW TRACK WILL DETERMINE EXACT PRECIP TYPE
AND AMOUNTS...BUT CURRENT SOLUTION WOULD POINT TO PRIMARILY
ANOTHER MODERATE RAIN EVENT FOR THE CWA FOR SUNDAY NIGHT INTO TUESDAY.
LATER MODEL RUNS WILL NEED TO BE MONITORED...AS ECMWF DIGS A
NORTHERN STREAM WAVE INTO THE MIDWEST FOR A MORE PHASED SYSTEM AND
POTENTIAL SNOW BAND ON THE NW SIDE OF THE STORM. AFTER A BRIEF
SHOT OF COLDER AIR BEHIND THIS LOW...ZONAL FLOW LOOKS TO MODERATE
TEMPS FOR MID WEEK.
25
&&
.AVIATION...
ISSUED 1150 AM CST WED DEC 14 2011
CEILINGS BELOW 1K FT ALONG I-74 TAF SITES OF PIA...BMI AND CMI MAY
LIFT FOR A TIME THIS AFTERNOON TO MVFR ESPECIALLY AT CMI WHILE
MVFR CEILINGS EXPECTED AT SPI AND DEC WITH DEC CURRENTLY DOWN TO
1K FT BROKEN CEILING. CONTINUED RAIN SHOWERS ACROSS THE CENTRAL IL
TERMINALS THIS AFTERNOON AND EVENING WITH ISOLATED THUNDERSTORMS
POSSIBLE BUT TOO TOUGH TO PIN POINT DOWN EXACT LOCATION AND TIME.
VISIBILITIES OF 1 TO 3 MILES AT PIA AND BMI WITH RAIN AND FOG COULD
LIFT TO MVFR FOR A TIME THIS AFTERNOON. MEANWHILE CMI WILL HAVE
MVFR VSBYS AND POSSIBLY VFR AT TIMES WHILE DEC AND SPI TO SEE MVFR
VSBYS RETURN DURING THE AFTERNOON WITH RETURN OF MORE RAIN
SHOWERS FROM THE SW. 1007 MB LOW PRESSURE OVER NORTHCENTRAL KS TO
DEEPEN NE TO 1002 MB OVER EAST CENTRAL WI BY MIDNIGHT AND TO 992
MB OVER SW QUEBEC BY 18Z/NOON THU. THIS TO SWING A COLD FRONT SE
THROUGH CENTRAL IL LATER TONIGHT...REACHING PIA BY 09Z AND CMI BY
12Z. SHOWERS END AFTER FRONTAL PASSAGE AS STRONG SOUTH WINDS WITH
GUSTS INCREASING TO 23-28 KTS DURING THIS AFTERNOON...TURN W/NW
BEHIND THE FRONT LATE TONIGHT AND THU MORNING. CONTINUE BROKEN TO
OVERCAST CEILINGS OF 1-2K FT BEHIND THE COLD FRONT THU MORNING AS
VFR VISBILITIES ARRIVE WITH FOG LIFTING.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
418 PM EST WED DEC 14 2011
.SHORT TERM...
TONIGHT THROUGH THURSDAY NIGHT...
KIWX RADAR DEPICTING BAND OF MOD/HVY RAIN ALONG/AHEAD OF WARM FRONT
LIFTING NORTH THROUGH THE AREA THIS AFTERNOON. THIS IS IN
ASSOCIATION WITH DEVELOPING SFC LOW IN CENTRAL PLAINS. WATER VAPOR
IMAGERY AND LATEST RUC ANALYSIS SHOWING LEAD SHORT WAVE EJECTING OUT
OF FOUR CORNERS AND WILL COMBINE WITH COUPLED JET STRUCTURE FROM
NORTHERN GREAT LAKES DOWN INTO THE CENTRAL PLAINS TO DEEPEN SFC LOW
AND DRIVE IT INTO WESTERN GREAT LAKES THIS EVENING. THIS WILL
PLACE THE FCST AREA IN ENHANCED MOIST SOUTHERLY FLOW IN THE WARM
SECTOR AND SUPPORT ANOTHER ROUND OF PRECIPITATION TONIGHT. COLD
FRONT WILL MOVE THROUGH THE AREA ON THURSDAY AND BRING AN END TO
RAIN BY 18Z. SIGNIFICANT DRYING BEHIND THE FRONT ALONG WITH MARGINAL
DELTA T WILL PROVIDE LITTLE SUPPORT FOR LES IN THE WAKE OF THIS
SYSTEM SO FAVOR CURRENT GRIDS IN KEEPING JUST A MENTION OF FLURRIES
ATTM. FIRST TWO PERIODS OF FCST WILL FEATURE NON-DIURNAL TEMP
PATTERN AS WARM FRONT LIFTING NORTH OF THE AREA TONIGHT WILL KEEP
TEMPS STEADY/SLOWLY RISING...THEN CAA BEHIND PASSAGE OF COLD FRONT
THURSDAY WILL SEE HIGHS REACHED IN THE MORNING FOLLOWED BY FALLING
TEMPS IN THE AFTERNOON. COOLER BUT SEASONABLE TEMPS THURSDAY NIGHT
WITH LOWS IN THE MID-UPPER 20S.
&&
.LONG TERM...
FRIDAY THROUGH WEDNESDAY
ACTIVE NORTHERN STREAM WILL INFLUENCE LOWER HEIGHTS INTO THE REGION
THIS WEEKEND WITH COLDER/DRIER AIR PUSHING INTO THE GREAT LAKES...AS
PERIPHERY DISTURBANCES ADVECT THROUGH THE FLOW. A SERIES OF THESE
WEAK INFLUENCES MAY INFLUENCE ENOUGH LIFT AND COLUMN SATURATION TO
SUPPORT LIGHT SNOW OR FLURRIES ACROSS THE NORTH...ALONG WITH A WEAK
LAKE RESPONSE. OTHERWISE...MODELS AND ENSEMBLES CONTINUE TO SUPPORT
THE EJECTION OF A SW CONUS DISTURBANCE INTO THE REGION BY EARLY NEXT
WEEK...WITH SOME RATHER SIG DISCREPANCIES AMONG DETERMINISTIC
SOLUTIONS. WILL STAY THE COURSE WITH PERSISTENCE...FAVORING THE
WARMER ECMWF AND GEM. THIS WILL ESP BE TRUE IF FLOW PHASING IS
REALIZED...WHICH IS CERTAINLY POSSIBLE GIVEN THE PATTERN. SMALL
ADJUSTMENT MADE TO THE PREVIOUS FORECAST...GENERALLY TO POPS/WX.
FRI-SUN...OVERALL DRY/SLIGHTLY DISTURBED FLOW WILL REMAIN IN THE
GREAT LAKES REGION. CONTINUED TO OPT NOT TO INCLUDE A LAKE EFFECT
SNOW SHOWER MENTION FRI-SAT FAR NW GIVEN MARGINAL SUPPORT FOR LAKE
INDUCE CONVECTION...WITH ONLY A FLURRY MENTION ATTM...SPREAD OVER
THE ENTIRE NORTH TO COVER THE POTENTIAL FOR LIGHT SNOW WITH ANY OF
THE WEAK DISTURBANCES. PROFILES INDICATE SIG DRYING IN THE SFC TO H8
LAYER WITH MARGINAL DELTA T/S PRESENT. CANNOT RULE OUT A FEW
FLURRIES OR LIGHT LAKE EFFECT SNOW SHOWERS IF COLDER PROFILES
VERIFY...COUPLED WITH A WEAK NORTHERN STREAM DISTURBANCE PROGGED
INTO THE REGION...WHICH COULD GENERATE ENOUGH INVERSION HEIGHT
UNDULATION TO SUPPORT PERHAPS A FEW SNOW SHOWERS/FLURRIES IN SHORT
FETCH WESTERLY FLOW. OTHERWISE...TEMPS ARE EXPECTED TO REMAIN AROUND
NORMAL TO SLIGHTLY ABOVE IN THE PERIOD...WITH LAKE EFFECT CLOUDS
ACROSS NORTHERN AREAS LINGERING THROUGH SAT.
MON-WED...CHANCES FOR A DECENT STORM SYSTEM CONTINUE...AS AN ACTIVE
NORTHERN STREAM IMPULSE LIKELY INTERACTS WITH ANOTHER SW CONUS
UPPER LOW. ADVECTION TIMING/THERMAL FIELDS/AND HEIGHT FALL DEPTH
INTO THE REGION IS STILL MUCH UNCERTAIN...BUT GIVEN THE GFS/S
TENDENCY TOWARD PROGRESSIVE FLOW...LIKELY BIASING THE NAEFS
SOLUTIONS...HAVE CONTINUED TO SIDE TOWARD THE MORE RELIABLE ECMWF. A
TREND TO A DEEPER H5 SOLUTION WOULD CERTAINLY BE NEEDED...ESP IF
WAVE PHASING RESULTS...WITH COUPLED JET DYNAMICS LIKELY SHIFTING THE
SFC LOW TRACK NW OF THE FA...AS SEEN IN THE GEM. RETAINED A
RAIN/SNOW MENTION IN MOST PERIODS...MAINLY TO COVER
UNCERTAINTY...BUT IT CERTAINLY LOOKS LIKE RAIN WILL BE THE DOMINATE
WEATHER TYPE IN THE PERIOD...ESP SE HALF. CONTINUE TO EXPECT MORE
ADJUSTMENT IN THIS PERIOD.
&&
.AVIATION.../18Z TAFS/
KIWX RADAR INDICATING BAND OF MODERATE TO HEAVY RAIN IMPACTING KSBN
ATTM AND IS EXPECTED TO ARRIVE AT KFWA BETWEEN 19-20Z THIS AFTERNOON
KEEPING IFR CONDITIONS OVER THE AREA THROUGH MUCH OF THE TAF PERIOD.
LOW PRESSURE WILL TRACK UP INTO THE WESTERN GREAT LAKES THIS EVENING
KEEPING GUSTY S/SW FLOW AND LLWS AT BOTH TAF SITES INTO THE EARLY
MORNING HOURS THURSDAY. COLD FRONT WILL MOVE THROUGH THURSDAY
MORNING AND BRING AN END TO THE RAIN BUT LOW LEVEL MOISTURE WILL
KEEP IFR/MFVR CIGS OVER THE AREA THROUGH THE END OF THE TAF PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...GALE WATCH THROUGH THURSDAY EVENING FOR LMZ043-046.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...JC
AVIATION...LOGSDON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1143 AM EST WED DEC 14 2011
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
RAIN SHOWERS WILL IMPACT THE REGION THROUGH EARLY THURSDAY AS FIRST
A WARM FRONT THEN A COLD FRONT PASS THROUGH THE OHIO VALLEY. IN THE
WAKE OF THIS FRONT...HIGH PRESSURE WILL BUILD INTO THE AREA THROUGH
THE WEEKEND. A LOW PRESSURE SYSTEM MAY APPROACH THE AREA FROM THE
SOUTHWEST EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
FORECAST CHALLENGES FOR THIS AFTERNOON INCLUDE TEMPERATURES AND
HOW TO HANDLE POPS. A DECENT STRATUS LAYER HAS LINGERED ACROSS
THE REGION HINDERING AN INCREASE IN TEMPERATURES...MAINLY ACROSS
THE NORTHERN HALF. THEREFORE...DECREASED HIGHS 2-3 DEGREES ACROSS
THIS AREA SINCE IT WILL ALSO BE THE FOCUS FOR ANY AFTERNOON
SHOWERS WHICH WILL CONTINUE TO INHIBIT WARMING. TEMPERATURES
ACROSS THE SOUTH APPEAR TO BE ON TRACK AND RISING AS EXPECTED SO
DID NOT MESS WITH THE PREVIOUS FORECAST.
SIGNIFICANTLY CUT POPS ACROSS THE CENTRAL PORTION OF THE FORECAST
AREA AND COMPLETELY REMOVED ANY PRECIPITATION MENTION FOR THE SOUTH
AND EAST BEFORE 21Z. THE LATEST RUC AND HRRR DATA DEPICT RAINFALL
SHOULD REMAIN OUT OF THIS AREA FOR MOST OF THE NEAR TERM. ON THE
OTHER HAND...CONTINUED LIKELY POPS ACROSS THE EXTREME NORTHWEST AS
CURRENT RADAR TRENDS INDICATE THE MAIN PRECIPITATION SHIELD MOVING
INTO THE NORTHWEST QUADRANT OF THE STATE. REGARDING THUNDER
MENTION...WITHOUT ANY REAL INSTABILITY...LEFT ANY MENTION OUT OF
THE GRIDS PRIOR TO 21Z. LEFT SLIGHT CHANCE WORDING IN THE
NORTHWEST AS LATEST MODELS SOUNDINGS INDICATE SOME ELEVATED
CONVECTION CANNOT BE COMPLETELY RULED OUT.
LASTLY...DECREASED WINDS THROUGHOUT THE NEAR TERM. EVEN WITH A
DECENT PRESSURE GRADIENT ACROSS THE AREA...OBSERVATIONS AND
LATEST GUIDANCE INDICATE WINDS WILL BE MORE IN THE 10-15 KT RANGE
THIS AFTERNOON AS COMPARED TO 15-20 KTS...OR HIGHER...AS INDICATED
PREVIOUSLY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
BREAK IN RAIN WILL BE SHORT LIVED AS THE AFFECTS OF THE APPROACHING
EJECTING LOW AND SURFACE COLD FRONT BEGIN MOVING INTO THE NORTHWEST
ZONES LATER THIS AFTERNOON AND THROUGH EVENING. MODELS REMAIN IN
GOOD AGREEMENT WITH THIS FEATURE AND ARE ACTUALLY EVEN MORE
PROGRESSIVE THAN PREVIOUS MODEL RUNS. 850 MB JET LOOKS EVEN STRONGER
THIS RUN AROUND 60 KTS ACROSS CENTRAL INDIANA BY 06Z. LOOK FOR GUSTY
WINDS AROUND 35 TO 40 MPH. WILL CONTINUE TO GO WITH 100% POPS...AND
A CHANCE FOR THUNDERSTORMS TO ACCOUNT FOR THE ELEVATED INSTABILITY.
WE ARE NOT IN A RISK FOR SEVERE WX.
AS JUST MENTIONED...MODELS ARE MORE PROGRESSIVE WITH THE
FRONT...BASICALLY CLEARING IT OF THE FORECAST ARE BY LATE THU MORN.
THINK THIS MIGHT BE A LITTLE TOO FAST BASED ON PAST EVENTS...SO WENT
WITH A SLIGHTLY SLOWER FROPA TIMING...REDUCING CHANCES FROM NW TO SE
THROUGHOUT THE DAY THU. IT DOES APPEAR THAT THE BULK OF THE RAIN
WILL BE OVER BY LATE THU MORNING FOR LOCATIONS NORTH OF I-70...WITH
THE REST TO THE AREA TO FOLLOW SHORTLY THEREAFTER.
TEMPERATURE FORECAST IS OF COURSE TRICKY...DEPENDING ON THE EXACT
POSITION OF THE FRONT. SINCE THIS MODELS WERE MORE PROGRESSIVE THIS
ROUND...DROPPED HIGHS ACROSS THE NW COUNTIES SLIGHTLY DURING THE DAY
THU.
HIGH PRESSURE BUILDS IN POST FROPA. LOOK FOR A RETURN TO COOLER AND
DRY WX.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
FAIRLY WIDE DISCREPANCY IN GUIDANCE WITH HANDLING OF NEXT
SIGNIFICANT WEATHER MAKER IN THE LONG TERM PERIOD...LATE IN THE
WEEKEND INTO EARLY NEXT WEEK. HOWEVER...THERE REMAINS A GENERAL
CONSENSUS IN FORMATION OF A LOW PRESSURE SYSTEM TO OUR
WEST/SOUTHWEST LATE IN THE WEEKEND WHICH THEN PUSHES INTO THE
REGION LATE SUNDAY NIGHT THROUGH TUESDAY NIGHT...AND ALLBLEND POPS
REFLECT THIS WELL.
GIVEN ANTICIPATED UPPER LEVEL PATTERN...TEMPS LOOK REASONABLE AS
WELL. SEE NO REASON TO DEVIATE FROM ALLBLEND WITH SIGNIFICANT
DISCREPANCIES IN GUIDANCE.
&&
.AVIATION /UPDATE FOR 141530Z TAFS/...
PREVIOUS DISCUSSION SUMMARIZES SITUATION WELL. AS IT INDICATES...
FREQUENT UPDATING WILL BE NEEDED TODAY. THE PREVIOUS DISCUSSION
FOLLOWS.
POOR FLYING CONDITIONS THROUGH THE PERIOD AS AMPLE LOW LEVEL
MOISTURE STREAMS ACROSS THE AREA AHEAD OF DEVELOPING LOW PRESSURE TO
THE WEST.
ALL SITES IFR IN ONE MANNER OR ANOTHER...MOST WITH BOTH CEILINGS AND
VISIBILITIES. SHOULD SEE SOME IMPROVEMENT DURING THE COURSE OF THE
DAY...MORE LIKELY AT IND/BMG AS IT APPEARS THESE SITES WILL BE A BIT
NEARER THE EDGE OF THE WIDESPREAD IFR TO OUR WEST.
THAT SAID...FLUCTUATIONS ARE LIKELY AND CONFIDENCE IS LOW IN THE
EXACT DETAILS OF THE FORECAST...ALTHOUGH RELATIVELY HIGH IN SOME
MANNER OF RESTRICTION THROUGH MUCH OF THE PERIOD.
WILL BE A LULL IN PRECIP THROUGH MUCH OF TODAY WITH ADDITIONAL RAIN
MOVING IN THIS EVENING. THUNDER CANNOT BE RULED OUT...BUT REMAINS
LOW PROBABILITY AND WILL BE LEFT OUT AT THIS TIME.
WINDS WILL INCREASE TO AROUND 15KT LATER TODAY AND REMAIN RELATIVELY
STRONG THROUGHOUT. A FEW GUSTS CANNOT BE RULED OUT THIS
AFTERNOON...BUT FEEL THAT CLOUD COVER WILL HELP TO SUPPRESS THIS
SOMEWHAT. GUSTS WOULD ONLY BE TO AROUND 20-25KT.
LATER TONIGHT...A STRONG LOW LEVEL JET /50-60KT/ WILL ACCOMPANY THE
COLD FRONT AS IT APPROACHES. WILL INCLUDE LOW LEVEL WIND SHEAR AS
MOMENTUM TRANSFER PROGS INDICATE LITTLE GUSTINESS OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...HOMANN/CP
SHORT TERM...SMF
LONG TERM....NIELD
AVIATION...JK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
319 PM CST WED DEC 14 2011
.SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB WARM FRONT FROM SOUTH DAKOTA INTO
SOUTHERN WISCONSIN. A LLJ RAN FROM THE WESTERN GREAT LAKES TO NORTH
TEXAS WITH THE STRONG CORE OF 50-55 KNOTS FROM EASTERN KANSAS INTO
NORTH TEXAS. A STRONG MOISTURE FEED RAN FROM THE GULF COAST INTO THE
WESTERN GREAT LAKES. RADAR TRENDS SHOW THE CONVECTION AND
THUNDERSTORMS HAVE SHIFTED INTO EASTERN ILLINOIS WITH PRECIPITATION
INTENSITY DECREASING ACROSS IOWA AND MISSOURI.
18Z SFC ANALYSIS HAD A WEAK LOW NEAR KLNK WITH A WARM FRONT ALONG
THE IA/MO BORDER INTO CENTRAL ILLINOIS. A COLD FRONT RAN FROM THE
LOW BACK INTO SOUTHEAST COLORADO. DEW POINTS SOUTH OF THE WARM FRONT
WERE IN THE 50S AND 60S.
&&
.SHORT TERM...TONIGHT AND THURSDAY...
THE RUC HAS BEEN DOING A REASONABLE JOB OF HANDLING THE IMMEDIATE
SHORT TERM AND THE TRENDS OF THE RUC WERE FOLLOWED FOR INPUT TONIGHT.
THE LIFT TOOL INDICATES THE THREAT OF THUNDER IS NOW OVER WITH THE
PASSAGE OF A STRONG VORT MAX. OVERALL PRECIPITATION INTENSITY WILL
NOW BE LIGHT DURING THE EVENING HOURS WITH EVERYTHING TRANSITIONING
TO MORE DRIZZLE WITH TIME. THUS DRIZZLE WITH SOME RAIN WILL BE SEEN
DURING THE EVENING HOURS ALONG WITH PATCHY FOG. AFTER MIDNIGHT...
CONDENSATION PRESSURE DEFICITS SLOWLY RISE IN THE WEST WITH THE
BETTER FORCING SHIFTING EAST OF THE MISSISSIPPI. THE RUC DOES SHOW
ANOTHER ROUND OF FORCING ARRIVING AROUND MIDNIGHT IN THE WESTERN
CWFA. THUS WILL CONTINUE THE DRIZZLE WITH OVERALL LOWER CHANCES OF
RAIN. PATCHY FOG WILL STILL BE AN ISSUE AFTER MIDNIGHT.
THE OVERALL DENSE FOG IS PATCHY IN NATURE AND GENERALLY CONFINED TO
THE HWY 20 CORRIDOR. THE MORE WIDESPREAD AND LIKELY DENSE FOG SHOULD
BE SEEN ACROSS WISCONSIN AND MINNESOTA WHERE THE SFC LOW TRACKS.
THE COLD FRONT WILL MOVE THROUGH THE CWFA AFTER MIDNIGHT. WINDS
SHOULD REMAIN UP WHICH WILL KEEP THE FOG FROM GETTING TOO DENSE AS
THE OVERALL ATMOSPHERIC COLUMN COOLS. LOW TEMPERATURES SHOULD OCCUR
BETWEEN 7 AND 9 AM THURSDAY MORNING.
THURSDAY...THERE MAY OR MAY NOT BE SOME LINGERING DRIZZLE ACROSS THE
EASTERN CWFA EARLY IN THE MORNING. CONDENSATION PRESSURE DEFICITS
CONTINUE TO RISE AND NO FORCING IS PRESENT. HOWEVER...FORECAST
SOUNDINGS DO SHOW CONSIDERABLE DRYING ABOVE THE LOW CLOUDS SO SOME
DRIZZLE MAY BE POSSIBLE. CLEARING WILL BE SLOW TO OCCUR DURING THE
MORNING. AS HIGH PRESSURE BEGINS BUILDING IN BY MID DAY A GENERAL
CLEARING OF SKIES SHOULD BE SEEN FROM WEST TO EAST DURING THE
AFTERNOON. MAX TEMPERATURES WILL OCCUR BETWEEN 7 AND 9 AM THURSDAY
MORNING WITH TEMPERATURES SLOWLY FALLING THROUGH THE DAY.
..08..
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...THE LONG TERM
BEGINS WITH A BRIEF COOL DOWN IN THE WAKE OF OUR CURRENT
STORM...THEN AFTER ABOUT 48 HOURS OF NORTHWEST FLOW...WE BEGIN TO
TREND TOWARD ANOTHER POTENTIAL SIGNIFICANT STORM SYSTEM FOR SUNDAY
NIGHT THROUGH TUESDAY.
MOISTURE WILL BE STARVED...BUT SOME POSSIBLE FLURRIES OR BRIEF LIGHT
SNOW COULD OCCUR SATURDAY AFTERNOON IN THE FAR NORTH AS SHEARED OUT
SHORT WAVE ARRIVES FROM THE NORTHWEST. THIS LOOKS TO MAIN PRODUCE
MID CLOUDS DURING THE AFTERNOON AND EVENING HOURS SATURDAY.
TEMPERATURES WILL BE COOL...BUT NOT COLD. WITH LOWS IN THE LOWER TO
MID 20S...AND HIGHS GENERALLY IN THE LOWER TO UPPER 30S.
SUNDAY...THERE BEGINS TO BE ANOTHER CHANGE TOWARD AN ACTIVE STORM
SYSTEM. THERE ARE MAJOR DIFFERENCES IN THE POSITION OF A NORTHWEST
FLOW WAVE THAT MAKES LANDFALL ON EITHER THE SOUTHWEST CANADIAN
COAST/BRITISH COLUMBIA...OR NORTHWESTERN CONUS. THIS SMALL
DIFFERENCE IN MODELS GREATLY INFLUENCED THE AMOUNT OF PHASING OF THE
UPPER LOW WHICH SHOULD BE CUT OFF IN THE SOUTHWEST CONUS AT THAT
TIME. THE UKMET...GEM...AND ECMWF CONTINUE TO SHOW THE NORTHWEST
FLOW WAVE HITTING THE WA/OR COASTLINE THEN DRAWING THE CUT OFF LOW
NORTHEAST SUNDAY NIGHT. THE GFS MAKES A MORE NORTHERLY ENTRY INTO
CENTRAL BRITISH COLUMBIA WITH THE NORTHWESTERN SHORT
WAVE...THUS...IT IS DELAYED BY 24 HOURS ON PHASING WITH THE LOW IN
THE SOUTHWEST...AND LESS SO AT THAT. THUS...FOR THAT REASON
ALONE...THE GFS REMAINS FAR SOUTH OF OTHER GLOBAL MODELS...AS WELL
AS SLOWER. THE CURRENT STORM OVERHEAD WAS ALSO FORECAST BY THE GFS
TO BE FARTHER SOUTH WHEN IT WAS OUT IN THIS DAY 6 PERIOD FOR SIMILAR
REASONS...AND THEREFORE WHEN COMBINED WITH THE FACT THAT THERE IS
LITTLE OR NO SNOW COVER IN THE MIDWEST AND THERE IS NO ARCTIC AIR IN
PLACE TO KEEP A SYSTEM SOUTH...I BELIEVE IN A MORE PHASED NORTHERLY
SOLUTION. THIS POTENTIAL STORM LOOKS TO HAVE ANOTHER OPEN GULF...AND
MODEST TO STRONG UPPER FORCING. THUS...SHOULD IT OCCUR...ANOTHER
ROUND OF MODERATE RAIN IS LIKELY.
SNOW MAY OCCUR ON THE BACKSIDE PENDING THE SPEED OF THE SYSTEM AND
ABILITY TO DYNAMICALLY COOL THE ATMOSPHERE. THERE IS LITTLE
CONFIDENCE IN THAT PROCESS AT THIS TIME...BUT ENOUGH TO WARRANT
INCLUDING A RAIN OR SNOW FORECAST FOR THE NORTHWEST HALF MONDAY
NIGHT. TUESDAY MAY SEE SNOW...BUT THAT WILL DEPEND GREATLY ON THIS
SYSTEM REMAINING CLOSED AT MID LEVELS. WEDNESDAY OF NEXT WEEK
APPEARS DRY AND SEASONALLY COOL.
..ERVIN..
&&
.AVIATION...
IFR TO LIFR CONDITIONS WILL CONTINUE THROUGH 12Z/15. THE PASSAGE OF
A SHORTWAVE ALOFT HAS ENDED THE TS THREAT FOR KMLI/KBRL. WINDS
SHOULD REMAIN UP TO PREVENT VSBYS FROM DROPPING BLO 3SM BUT BRIEF
INCURSIONS BLO 3SM WILL BE POSSIBLE. OVERALL CONDITIONS WILL IMPROVE
TO MVFR AFT 12Z/15 WITH CONDITIONS IMPROVING TO VFR AFT 18Z/15.
..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
506 PM EST WED DEC 14 2011
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS EVENING, WITH A BREAK
IN PRECIPITATION EXPECTED EARLY TONIGHT. SHOWERS WILL BE MORE
PERSISTENT THURSDAY WHEN A COLD FRONT CROSSES THE REGION. IN THE
WAKE OF THE FRONT, SNOW SHOWERS WILL BE POSSIBLE EARLY FRIDAY
ALONG THE I-80 CORRIDOR AND EASTERN RIDGES.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES WEAK RIDGING MOVING
ACROSS THE UPPER OHIO VALLEY. AT THE SURFACE, A 1006MB LOW IS
CENTERED ACROSS THE CENTRAL PLAINS WITH A WARM FRONT EXTENDING
ACROSS THE MISSOURI AND LOWER OHIO VALLEYS. WELL UPSTREAM, A COLD
FRONT EXTENDS SOUTH OF THE LOW INTO THE SOUTHERN PLAINS. AHEAD OF THE
WARM FRONT, LIFT FROM OVERRUNNING IS ALLOWING FOR SCATTERED
SHOWERS TO PUSH NORTHEAST OF THE AREA. A LAYER OF 850-500MB DRY
AIR IN THE WARM SECTOR IS ALLOWING FOR CLEARING ACROSS PORTIONS OF
EASTERN OHIO.
TONIGHT...THE WARM FRONT WILL LIFT NORTH OF THE AREA. WITH LIFT
FROM OVERRUNNING PUSHING NORTH OF THE AREA, EXPECT MOST OF THE
FORECAST AREA TO BE DRY FROM 00Z THROUGH 06Z. AFTER 06Z, NAM12 AND
WRF-NMM SUPPORT DEEPER MOISTURE ASSOCIATED AHEAD OF THE COLD FRONT
IN ILLINOIS BEGINNING TO PUSH INTO EASTERN OHIO. THUS, THIS WILL
ALLOW FOR AN AREA OF MORE PERSISTENT SHOWERS TO BEGIN TO SHIFT
INTO THE AREA. CHC POPS IN OHIO WILL INCREASE TO CATEGORICAL POPS
ACROSS WESTERN PA AND EASTERN OHIO BY DAWN ON THURSDAY.
STRONG WARM AIR ADVECTION OVERNIGHT WILL ALLOW FOR NEAR STEADY TEMPS
INITIALLY THAT WILL BEGIN TO INCREASE DURING THE PRE-DAWN HOURS.
TEMPS OVERNIGHT WILL RANGE FROM THE MID 40S ACROSS THE EASTERN
RIDGES TO THE LOWER 50S IN EASTERN OHIO.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
GFS/NAM/CANADIAN ARE IN REASONABLE AGREEMENT IN THE TIMING AND QPF
WITH THE COLD FRONT AS IT PUSHES ACROSS THE OHIO VALLEY AND INTO THE
AREA BY THURSDAY EVENING. CATEGORICAL POPS ARE FORECAST AHEAD OF THE
FRONT WITH AROUND A HALF OF AN INCH OF RAIN EXPECTED ON THURSDAY.
WARM AIR ADVECTION WILL BE ONGOING IN A SOUTHWESTERLY LOW-LEVEL FLOW
IN THE WARM SECTOR. FORCING ALONG AND AHEAD OF THE FRONT ALONG WITH
WEAK INSTABILITY AND STRONG SHEAR MAY BE JUST ENOUGH FOR A FEW
THUNDERSTORMS EARLY THURSDAY AFTERNOON IN EASTERN OHIO. THUS, HAVE
INCLUDED A SCHC FOR THUNDER THERE. IN ADDITION, A TIGHTENING
PRESSURE GRADIENT AHEAD OF THE FRONTAL TROUGH WILL ALLOW FOR WIND
GUSTS OF UP TO 25 TO 30 MPH THURSDAY AFTERNOON.
MAV/MET GUIDANCE SEEM TO BE RESOLVING WARM AIR ADVECTION FAIRLY WELL
AHEAD OF THE FRONT, SO FORECAST IS A MOS BLEND. THIS WILL ALLOW HIGHS
ON THURSDAY TO BE 15-20 DEGREES ABOVE NORMAL. LOCATIONS IN
NORTH-CENTRAL WV AND PORTIONS OF EASTERN OHIO HAVE A GOOD SHOT OF
HITTING 60 TOMORROW.
THURSDAY NIGHT...THE COLD FRONT IS PROGGED TO PUSH EAST OF
PITTSBURGH AFTER 00Z FRIDAY WITH PRECIPITATION QUICKLY CUTTING OFF
IN THE WAKE OF THE FRONT. WINDS WILL SHIFT TO NORTHWESTERLY BEHIND
THE FRONT WITH COLD AIR ADVECTION ENSUING ACROSS LAKE ERIE. THE
TEMP DIFFERENTIAL BETWEEN 850 TEMPS AND LAKE ERIE SHOULD BE ENOUGH
TO INSTIGATE SOME LAKE EFFECT SNOW SHOWERS FOR THE I-80 CORRIDOR
BY THE PRE-DAWN HOURS FRIDAY AND UPSLOPING SNOW SHOWERS BY DAWN
FOR THE EASTERN RIDGES. COLD AIR ADVECTION WILL ALLOW FOR LOW
TEMPS TO DROP OFF SHARPLY OVERNIGHT WITH LOWS IN THE LOWER 30S
ACROSS MUCH OF THE AREA.
FRIDAY...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE WEST WITH A
COOL NORTHWESTERLY FLOW OFF THE GREAT LAKES CONTINUING. SNOW
SHOWERS FOR THE I-80 CORRIDOR AND EASTERN RIDGES WILL DIMINISH BY
THE AFTERNOON AS 850 TEMPS WARM AND WIND COMPONENT BECOMES MORE
WESTERLY. ACCUMULATIONS WILL BE LIGHT, GENERALLY LESS THAN AN INCH
WITH THE SNOW SHOWERS BEHIND THE FRONT. THE NORTHWESTERLY FLOW WILL
ALSO SERVE TO KEEP THE AREA CLOUDY ON FRIDAY. WITH THE ARCTIC AIR
MASS WORKING INTO THE AREA, TEMPERATURES WILL BE SLOW TO RECOVER
THROUGHOUT THE DAY. HIGHS WILL RANGE FROM THE MID 30S ACROSS THE
EASTERN RIDGES AND I-80 CORRIDOR TO THE LOWER 40S NORTH-CENTRAL WV.
FRIDAY NIGHT AND SATURDAY...HIGH PRESSURE WILL ALLOW FOR MOSTLY
DRY WEATHER FRIDAY NIGHT AND MOST OF THE DAY SATURDAY. LATE IN THE
DAY, A SHORT WAVE TROUGH WILL BEGIN TO DIVE FROM THE GREAT LAKES
SOUTHEASTWARD INTO THE AREA. THIS WILL RETURN THE CHANCE OF SNOW
SHOWERS, ESPECIALLY NORTH OF PITTSBURGH, BY THE EVENING.
TEMPERATURES WILL BE NEAR NORMAL SEASONAL VALUES.
&&
.LONG TERM /SATURDAY NIGHT NIGHT THROUGH WEDNESDAY/...
STILL VARYING MODEL SOLUTIONS THIS PERIOD REGARDING HOW MUCH ENERGY
THE NORTHERN BRANCH OF THE UPPER LEVEL JET, COMING EAST FROM
SOUTHERN CANADA, INPUTS INTO THE SOUTHERN JET STREAM BRANCH
EMANATING FROM CALIFORNIA. DEFERRING TO HPC OPINION, FAVORED NAEFS
SOLUTION OVER ECENS MODEL OUTPUT, WHICH SHOWED THE NORTHERN BRANCH
HAVING GREATER INFLUENCE.
THE EFFECT THIS HAS ON THE UPPER OHIO VALLEY WILL BE INITIALLY A
COLDER AIRFLOW ACROSS THE GREAT LAKES, WHICH WILL SUBSEQUENTLY
PROVIDE A LARGER COVERAGE OF LAKE ENHANCED CLOUDS AND LIGHT SNOW
SHOWERS SUNDAY.
IT ALSO MEANS A SLOWER-MOVING AND MORE DEVELOPED LOW PRESSURE SYSTEM
COMING NORTHEAST FROM TEXAS EARLY NEXT WEEK. PER GFS MOS AND NAEFS
MEDIAN VALUES, DAYTIME TEMPERATURES WILL BE NEAR SEASONABLE VALUES.
ASSOCIATED CLOUDS CAN CAUSE NIGHTTIME TEMPERATURES TO BE WARMER
THAN NORMAL, BUT NO WARMER THAN FREEZING FOR MOST LOCATIONS. SO
HAVE FORECASTED MIXED PRECIPITATION LATE MONDAY INTO WEDNESDAY.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA, COUPLED WITH RECENT
HRRR, GFS LAMP AND NAM MODEL OUTPUT, EXPECT POST-WARM FRONTAL BAND
OF IFR STRATUS TO BEGIN TO DISSIPATE THIS EVENING.
THIS SCENARIO IS TYPICALLY NOT FAVORED FROM A DIURNAL CLIMATOLOGICAL
VIEWPOINT. HOWEVER THERE APPEARS TO INCREASING LOW LEVEL DRYING IN
THE WARM SECTOR THAT CONDITIONS IMPROVE TO AT LEAST MVFR.
NAM MODEL PROFILES CONTINUE TO SHOW A LOW LEVEL JET, WITH
SOUTHWEST WINDS NEAR 40KT AT 2KFT AGL, DEVELOPING AFTER 03Z. HENCE
HAVE ADDED LOW LEVEL WIND SHEAR /LLWS/ TO ALL SITES 03Z-10Z.
NAM MODEL PROFILES THEN SHOW PASSAGE OF A COLD FRONTAL BAND OF
MODERATE SHOWERS LATE TONIGHT INTO MIDDAY THURSDAY, THAT SHOULD
LOWER FLIGHT CONDITIONS BACK INTO THE IFR RANGE. THE COLD FRONTAL
SHOWER BAND WILL PROVIDE SUFFICIENT VERTICAL MIXING TO COUPLE SOME
FASTER WINDS TO THE SURFACE AND SO END THE LLWS THREAT. NEAR THE
RIDGES, SURFACE SOUTHERLY WINDS CAN GUST TO 20-25 KTS. POST COLD
FRONTAL VERTICAL MIXING CAN INDUCE SOUTHWEST WIND GUSTS TO 25-30 KTS
FOR ALL SITES THROUGH THURSDAY AFTERNOON. AS SHOWER INTENSITY
DECREASES, THE VERTICAL MIXING SHOULD IMPROVE FLIGHT CONDITIONS TO
MVFR AS THE DAY WEARS ON.
OUTLOOK... THURSDAY NIGHT THROUGH MONDAY...
FOR THURSDAY NIGHT, FORESEE POSSIBLE LINGERING COLD POOL MVFR
STRATOCUMULUS AREAWIDE. FOR FRIDAY INTO SUNDAY, LINGERING MVFR
STRATOCUMULUS WILL BE POSSIBLE MAINLY NORTH AND MOUNTAINS. FOR
MONDAY, INCOMING WARM FRONTAL SHOWERS MAY PRODUCE RESTRICTIONS LATE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
118 PM EST WED DEC 14 2011
.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE UPPER OHIO VALLEY THIS
AFTERNOON, BRINGING SHOWERS TO THE AREA. SHOWERS WILL BE MORE
PERSISTENT THURSDAY WHEN A COLD FRONT CROSSES THE REGION. IN THE
WAKE OF THE FRONT, SNOW SHOWERS WILL BE POSSIBLE EARLY FRIDAY
ALONG THE I-80 CORRIDOR AND EASTERN RIDGES.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST RADAR TRENDS AS OVERRUNNING PRECIP HAS DECREASED
SIGNIFICANTLY IN COVERAGE.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES WEAK RIDGING MOVING
ACROSS THE UPPER OHIO VALLEY. AT THE SURFACE, A 1006MB LOW IS
CENTERED ACROSS THE CENTRAL PLAINS WITH A WARM FRONT EXTENDING
ACROSS THE MISSOURI AND LOWER OHIO VALLEYS. WELL UPSTREAM, A COLD
FRONT EXTENDS SOUTH OF THE FEATURE ACROSS THE SOUTHERN PLAINS. AHEAD
OF THE WARM FRONT, LIFT FROM OVERRUNNING IS ALLOWING FOR SCATTERED
SHOWERS TO PUSH ACROSS THE AREA. A LAYER OF 850-500MB DRY AIR IN THE
WARM SECTOR IS ALLOWING FOR CLEARING ACROSS SOUTHERN WEST VIRGINIA.
THIS AFTERNOON...THE WARM FRONT WILL CONTINUE TO PUSH NORTHWARD
CLOSER TO THE AREA WITH THE BEST LIFT WILL SHIFTING NORTH OF THE
AREA. THUS, SHOWERS WILL DECREASE IN COVERAGE ACROSS THE AREA AND
COME TO AN END SOUTH OF PITTSBURGH. SOME CLOUD BREAKS ARE EXPECTED
SOUTH OF PITTSBURGH AS THE LAYER OF DRY AIR MOVES INTO THE AREA ALONG
WITH THE WARM SECTOR. HIGHS WILL BE AROUND 10 DEGREES ABOVE
NORMAL, RANGING FROM THE MID 40S ACROSS THE I-80 CORRIDOR AND
EASTERN RIDGES TO THE LOWER 50S IN NORTH-CENTRAL WV AND EASTERN
OHIO.
TONIGHT...THE WARM FRONT WILL LIFT NORTH OF THE AREA. WITH LIFT
FROM OVERRUNNING PUSHING NORTH OF THE AREA, EXPECT MOST OF THE
FORECAST AREA TO BE DRY FROM 00Z THROUGH 06Z. AFTER 06Z, NAM12 AND
WRF-NMM SUPPORT DEEPER MOISTURE ASSOCIATED AHEAD OF THE COLD FRONT
IN ILLINOIS BEGINNING TO PUSH INTO EASTERN OHIO. THUS, THIS WILL
ALLOW FOR AN AREA OF MORE PERSISTENT SHOWERS TO BEGIN TO SHIFT
INTO THE AREA. CHC POPS IN OHIO WILL INCREASE TO CATEGORICAL POPS
ACROSS WESTERN PA AND EASTERN OHIO BY DAWN ON THURSDAY.
STRONG WARM AIR ADVECTION OVERNIGHT WILL ALLOW FOR NEAR STEADY TEMPS
INITIALLY AND BEGINNING TO INCREASE DURING THE PRE-DAWN HOURS. THUS,
TEMPS OVERNIGHT WILL RANGE FROM THE MID 40S ACROSS THE EASTERN
RIDGES TO THE LOWER 50S IN EASTERN OHIO.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THE MODELS ARE IN REASONABLE AGREEMENT THAT AN AREA OF DRY AIR WILL
PUSH INTO THE AREA WITH WAA IN THE WARM SECTOR AS A COLD FRONT
APPROACHES FROM THE WEST TONIGHT. WITH A BREAK IN PRECIP EXPECTED,
DRY OR SCHC POPS ARE FORECAST ACROSS MOST OF THE AREA. FORCING
FROM A COLD FRONT WILL SUPPORT PRECIP FOR THE AREA WITH
CATEGORICAL POPS REACHING THE PITTSBURGH METRO BY DAWN ON
THURSDAY. MORE PERSISTENT RAINFALL IS EXPECTED THROUGH MUCH OF THE
DAY THURSDAY AS THE FRONT SLOWLY PROGRESSES ACROSS THE OHIO
VALLEY. ONGOING WARM AIR ADVECTION WILL ALLOW FOR TEMPS TO BE 15
TO 20 DEGREES ABOVE NORMAL.
THE FRONT WILL CROSS THE AREA THURSDAY NIGHT WITH A LOW-LEVEL
NORTHWESTERLY FLOW AND HIGH PRESSURE BUILDING IN FROM THE WEST IN
ITS WAKE. 850MB AND LAKE ERIE TEMP DIFFERENTIAL WILL BE SUFFICIENT
TO SUPPORT A FEW LAKE EFFECT SNOW SHOWERS IN THE WAKE OF THIS
SYSTEM ON FRIDAY. TEMPS ON FRIDAY WILL BE SLIGHTLY BELOW NORMAL
UNDER CAA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
EXPECT A MAINLY DRY WEEKEND WITH NEAR TO BELOW NORMAL TEMPS.
STILL A GOOD DEAL OF UNCERTAINTY FOR EARLY NEXT WEEK. DIFFERENCES
IN MEDIUM RANGE MODELS WILL PROMOTE VERY LITTLE CHANGES TO LONG
TERM FORECAST.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA, COUPLED WITH RECENT
HRRR, GFS LAMP AND NAM MODEL OUTPUT, EXPECT POST-WARM FRONTAL BAND
OF IFR STRATUS AND DRIZZLE TO SPREAD NORTHEASTWARD THROUGH MUCH OF
THE UPPER OHIO VALLEY THIS AFTERNOON. HRRR FLIGHT RULE FORECASTS AND
NAM MODEL PROFILES, IN PARTICULAR, SHOW THE IFR CONDITIONS CAN
LINGER INTO EVENING. ITS POSSIBLE WITH LOWLEVEL SOUTHEAST WINDS THAT
LOCATIONS, SUCH AS KLBE, MAY DETERIORATE TO MAINLY JUST MVFR
CONDITIONS DUE TO DOWNSLOPING EFFECTS.
ALTHOUGH NOT FAVORED FROM A DIURNAL CLIMATOLOGICAL VIEWPOINT, THERE
MAY BE SUFFICIENT LOW LEVEL DRYING IN THE WARM SECTOR THAT
CONDITIONS IMPROVE TO MVFR. NAM MODEL PROFILES CONTINUE TO SHOW A
LOW LEVEL JET, WITH SOUTHWEST WINDS NEAR 40KT AT 2KFT AGL,
DEVELOPING AFTER 03Z. HENCE HAVE ADDED LOW LEVEL WIND SHEAR /LLWS/
TO ALL SITES 03Z-10Z.
NAM MODEL PROFILES THEN SHOW PASSAGE OF A COLD FRONTAL BAND OF
MODERATE SHOWERS THAT SHOULD LOWER FLIGHT CONDITIONS INTO THE IFR
RANGE. THE COLD FRONTAL SHOWER BAND WILL PROVIDE SUFFICIENT VERTICAL
MIXING TO COUPLE SOME FASTER WINDS TO THE SURFACE AND SO END THE
LLWS THREAT. NEAR THE RIDGES, SURFACE SOUTHERLY WINDS CAN GUST TO
20-25 KTS. POST COLD FRONTAL VERTICAL MIXING CAN INDUCE SOUTHWEST
WIND GUSTS TO 25-30 KTS FOR ALL SITES THROUGH THURSDAY AFTERNOON.
AS SHOWERS INTENSITY DECREASES, THIS VERTICAL MIXING SHOULD THEN
IMPROVE FLIGHT CONDITIONS TO MVFR.
OUTLOOK... THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT AND FRIDAY, FORESEE POSSIBLE LINGERING COLD POOL MVFR
STRATOCUMULUS AREAWIDE. SATURDAY AND SUNDAY, LINGERING MVFR
STRATOCUMULUS POSSIBLE MAINLY NORTH AND MOUNTAINS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1235 PM CST WED DEC 14 2011
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
A BIT OF A TRICKY FORECAST THIS MORNING WITH THE FIRST WAVE MOVING
THROUGH EAST CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN. RAIN
AND SNOW MIXED OCCURRING OVER PARTS OF CENTRAL MINNESOTA AND
WESTERN WISCONSIN. THE LATEST RUC AND VSREF PICKING UP ON THE LOW
LEVEL THICKNESS FIELDS AND MARGINAL 850 MB TEMPS AND IT COULD BE
ALL SNOW FOR A TIME EARLY. NOT MENTIONING MUCH ACCUMULATION AT
THIS POINT /LESS THAN AN INCH/ WITH MUCH OF THE FORCING MOVING
OUT. OTHERWISE WE WILL BE LEFT WITH MOST OF THE REMAINDER OF THE
MORNING WITH NOT REAL WIDESPREAD PRECIP...MOSTLY DRIZZLE.
FORTUNATELY...TEMPS MAINLY ABOVE 32 OR JUST AT 32 WHERE SOME SNOW
MOST ROAD TEMPS ON THE ARE NOT SUGGESTING A MAJOR THREAT FOR ICE.
MAY STILL INCLUDE A MENTION OF FREEZING DRIZZLE IN CENTRAL MN.
THE NAM AND GFS AND ARE GENERALLY IN LINE WITH BRINGING THE
SOUTHERN ROCKIES VORT NORTHEAST TOWARD IOWA WITH SIG FORCING
BRUSHING SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN DURING
THE AFTERNOON AND EVENING. THE TEMP STRUCTURE IS STILL INITIALLY
TOO WARM FOR MUCH SNOW BUT COOLING DOES TAKE PLACE AS THE 500 MB
HEIGHT FALLS TRACK ACROSS NORTHEAST IOWA. HAVE INDICATED NEAR AN
INCH OF SNOW FOR PARTS OF EAST CENTRAL MN AND WEST CENTRAL
WISCONSIN BUT WILL NEED TO WATCH THE TRENDS DURING THE DAY. THERE
IS CERTAINLY PLENTY OF MOISTURE WITH PWAT VALUES OVER 300 PERCENT
OF NORMAL THROUGH THE CENTRAL PLAINS.
BLUSTERY AND COLDER CONDITIONS MOVE IN FOR THURSDAY WITH COLD
ADVECTION KEEPING TEMP TRENDS STEADY FROM OVERNIGHT LOWS IN SOME
AREAS.
THE CLIPPER TYPE SYSTEM MOVING INTO THE AREA ON FRIDAY LOOKS
WELL DEFINED BUT LACKING MOISTURE. HAVE INTRODUCED AT LEAST A SLIGHT
CHANCE FOR LIGHT SNOW IN THE WEST BUT THERE MAY BE A NEED TO
EXPAND THAT IN LATER FORECASTS. SATURDAY LOOKS MILD BEHIND THAT
SYSTEM WITH DECENT CHANCE OF BRINGING SOME LOW 40S INTO THE
SOUTHWEST..EAST OF THE BUFFALO RIDGE.
ANOTHER SYSTEM IN THE SPLIT FLOW WILL NEED TO BE WATCHED MID
WEEK. THIS LOOKS TO BE MAINLY SOUTHEAST OF OF OUR AREA BUT THE
TRACKS OF PAST SYSTEMS THIS EARLY WINTER HAVE AFFECTED THE
SOUTHEAST HALF OF OUR FORECAST AREA...AND THE SAME MAY HOLD TUE
WITH THIS ONE.
&&
.AVIATION.../18Z TAF ISSUANCE/
DEEP UPPER TROUGH OVER THE THE CENTRAL CONUS SENDING A SWARM OF
SHORTWAVES OUR DIRECTION AND WILL CONTINUE TO KEEP SIMPLY UGLY
CONDITIONS IN PLACE...WITH WIDESPREAD LIFR/IFR CONDITIONS EXPECTED
TO PERSIST AT ALL LOCATION THROUGH AT LEAST 06Z. THROUGH TONIGHT...
A RWF TO SIREN...WI LINE WILL BE A GOOD SEPARATION OF EXPECTED
WEATHER. NW OF THIS LINE...DENSE FOG HAS BEEN IN PLACE ALL
MORNING. GFSLAMP FROM BOTH AXN/STC KEEP 1/2SM OR LESS VSBY IN
PLACE THROUGH 6Z. DID NOT KEEP VIS THAT LOW FOR THAT LONG IN
THESE TAFS...AS WAVE MOVING ACROSS THE CENTRAL DAKOTAS HAS BE
SPREADING DZ/SN/RA EAST. THIS PRECIP SHOULD REACH CENTRAL/WRN MN
AROUND 00Z WITH THE HOPE THAT AS IT DOES SO...THE PRECIP WILL HELP
MIX THINGS ENOUGH TO GET THE VSBYS ABOVE 1/2SM. SE OF THE
AFOREMENTIONED LINE...RA AND DZ WILL DOMINATE THE WEATHER THROUGH
06Z. CIGS SHOULD REMAIN AT OR BELOW 005 DURING THIS TIME...BUT THE
FALLING RAIN WILL HELP HOLD VSBYS UP TO BETWEEN 2SM AND 4SM.
P-TYPE WITH THIS LOOKS TO REMAIN MOSTLY RAIN...BUT BETWEEN 3Z AND
6Z A TRANSITION TO SNOW WILL BE POSSIBLE...BUT BY THEN THE PRECIP
WILL BE MOVING OUT. ESTABLISHMENT OF W/NW WINDS AFTER 00Z FROM
WEST TO EAST WILL HELP CLEAN OUT THE FG AND RAIN TONIGHT...BUT IFR
CIGS LOOK TO REMAIN IN PLACE MOST OF THE NIGHT. GOING INTO
THURSDAY MORNING...STRONG CAA MOVING IN FROM THE NW DURING THE
MORNING WILL ALSO BRING ALONG A REINFORCING SHOT OF
STRATUS...THOUGH BY THEN CIGS SHOULD IMPROVE TO MVFR LEVELS.
KMSP...LOOKING AT LATEST RADAR TRENDS...-RA LOOKS TO BE THE
PREDOMINATE PLAYER FOR THE NEXT FEW HOURS. MPXWRF/HRRR
REFLECTIVITY FORECASTS BOTH HANDLING THIS PRECIP WELL...WITH THE
BULK OF IT MOVING EAST OF MSP AFTER 04Z. FORECAST SOUNDINGS OFF THE
RUC/GFS SHOW IT BECOMING COLD ENOUGH OF SN BETWEEN 3Z AND
6Z...BUT BY THEN MAJORITY OF PRECIP LOOKS TO BE EAST OF FIELD...SO
ONLY HAVE A VCSH MENTION FOR NOW...BUT THERE COULD BE A BRIEF 2 OR
3 HOUR PERIOD WHERE -SN IS OBSERVED. RH PROFILE OFF THE NAM KEEPS
IFR CIGS IN PLACE THROUGH 12Z...AND GIVEN EXTENT OF CLOUDS TO THE
WEST...FAVORED A SLOWER SOLUTION FOR IMPROVING THINGS TO MVFR. CAA
DURING THE COURSE OF THE DAY THURSDAY SHOULD KEEP AT LEAST MVFR
CIGS IN PLACE INTO THE AFTERNOON...BUT HOPEFULLY WE WILL GET TO
SEE SOME SUN LATE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/MPG
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
331 PM CST WED DEC 14 2011
.DISCUSSION...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE ONGOING ACROSS NORTH
TEXAS THIS AFTERNOON AS A PACIFIC COLD FRONT MOVES EAST. THE UPPER
LEVEL SYSTEM RESPONSIBLE FOR DEEP LAYER ASCENT IS SHEARING OUT
ACROSS THE SOUTHERN PLAINS AND WILL MOVE NORTHEAST THIS EVENING
ALLOWING THE FRONTAL BOUNDARY TO SLOW DOWN AS IT MOVES EAST.
LATEST RUC SOUNDINGS AND LOCALLY DERIVED CONVECTIVE PARAMETERS
INDICATE THAT 700MB WARM NOSE HAS MOSTLY ERODED WITH ONLY WEAK
INHIBITION PRESENT IN VICINITY OF THE FRONT. ANYWHERE FROM
500-700J/KG OF INSTABILITY REMAINS PRESENT AND WILL SUPPORT
THUNDERSTORMS THROUGH THE REMAINDER OF THE EVENING INTO TONIGHT.
OVERALL SEVERE WEATHER THREAT IS LOW BUT SOME HAIL WILL REMAIN
POSSIBLE. FRONT WILL DRIFT SOUTH AND EAST LATER TONIGHT WITH
PRECIP TAPERING FROM WEST TO EAST.
ALTHOUGH SURFACE FRONT WILL BE SOUTH OF THE AREA ON THURSDAY AMPLE
MOISTURE WILL RIDE ATOP THE SHALLOW COOLER AIR. REMNANTS OF THE
UPPER LOW OVER THE SOUTHWEST IS EXPECTED TO EJECT NORTHEAST DURING
THE DAY TOMORROW. THIS SYSTEM SHOULD PROVIDE SUFFICIENT FORCING TO
LIFT MOISTURE IN THE 850-700MB LAYER. ELEVATED INSTABILITY WILL BE
WEAK ALTHOUGH IT SHOULD BE SUFFICIENT FOR SHOWERY TYPE PRECIP TO
DEVELOP EVEN THOUGH THE NEAR SURFACE LAYER WILL BE DRY. MODEL
GUIDANCE IS IN GOOD AGREEMENT ON THIS SOLUTION AND HAVE RAISED
POPS FOR THU/THU NIGHT ACROSS NORTH TEXAS.
FRIDAY AND SATURDAY STILL LOOK LIKE THE QUIETEST DAYS THROUGH THE
NEXT SEVERAL WITH MOST AREAS STAYING DRY. THE NEXT STRONG SYSTEM
IS EXPECTED TO MOVE OUT OF THE SOUTHWEST US BY SUNDAY. MOISTURE
WILL SURGE NORTHWARD AHEAD OF THIS UPPER LOW...WHICH IS FORECAST
TO REMAIN CLOSED AS IT MOVES ACROSS NORTH TEXAS. THIS SYSTEM
CONTINUES TO LOOK MORE POTENT AND AGAIN WE MAY SEE SOME
SIGNIFICANT RAINFALL AS IT MOVES THROUGH. WILL HAVE TO MONITOR FOR
SEVERE WEATHER POTENTIAL AS WE GET CLOSER TO THE EVENT.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 54 56 40 54 38 / 60 50 70 10 10
WACO, TX 58 58 42 53 42 / 90 60 70 20 20
PARIS, TX 55 57 39 51 37 / 90 40 70 20 10
DENTON, TX 51 54 38 51 33 / 40 40 70 10 10
MCKINNEY, TX 54 56 41 52 36 / 70 40 70 20 10
DALLAS, TX 55 58 41 54 41 / 70 50 70 20 10
TERRELL, TX 57 59 42 52 40 / 90 50 70 20 10
CORSICANA, TX 59 62 45 54 42 / 90 60 70 30 20
TEMPLE, TX 59 59 42 53 43 / 80 70 70 20 20
MINERAL WELLS, TX 48 52 37 50 35 / 10 40 60 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1119 AM CST WED DEC 14 2011
.AVIATION...
IFR CONDITIONS REMAIN FAIRLY EXTENSIVE ACROSS NORTH TEXAS LATE
THIS MORNING. LOCAL AIRPORTS ALONG THE I 35 CORRIDOR CONTINUE TO
REPORT CIGS AT OR BELOW 010 AND FEEL THIS WILL CONTINUE THROUGH
THE MID AFTERNOON HOURS. CONDITIONS SHOULD THEN IMPROVE SOME AS
TEMPERATURES APPROACH 70 AND WINDS BEGIN TO VEER AHEAD OF THE
PACIFIC FRONT TO THE WEST.
INSTABILITY SHOULD NOT BE OVERLY IMPRESSIVE AS INITIAL SHORTWAVE
MOVES ACROSS THE AREA THIS AFTERNOON. HOWEVER...CONVERGENCE ALONG THE
SURFACE BOUNDARY COMBINED WITH SB CAPES BETWEEN 500 AND 1000 J/KG
SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF THUNDERSTORMS. WILL
TIME THE ONSET OF OCCASIONAL TS IN THE METROPLEX SIMILAR TO THE
12Z LOCAL WRF SOLUTION...WHICH WOULD BEGIN AROUND 22Z. WINDS WILL
VEER TO THE SW BEHIND THE LEADING EDGE OF THE HEAVIER PRECIP. MAIN
PUSH OF COOLER DRIER AIR AT THE SURFACE WOULD BE LATE TONIGHT AND
WILL CONTINUE WITH THE NORTHWEST WINDS PRIOR TO SUNRISE TOMORROW.
IT LOOKS LIKE THE FRONT MAY HANG UP JUST SOUTH OF THE FORECAST
AREA TOMORROW. OVERRUNNING PRECIP WILL THEN BECOME A POSSIBILITY
BY TOMORROW AFTERNOON AS THE NEXT SHORTWAVE PROPAGATES EASTWARD
INTO THE AREA.
30
&&
.UPDATE...
ELONGATED TROF AXIS PERSISTS FROM THE CENTRAL PLAINS BACK INTO THE
SOUTHWEST US WITH ONE SIGNIFICANT PIECE OF ENERGY EJECTING
NORTHEAST THIS MORNING. THIS S/W WILL HELP PUSH A PACIFIC FRONT
THROUGH THE REGION THIS AFTERNOON. REGIONAL RADAR IMAGERY ALREADY
SHOWS A BROKEN LINE OF PRIMARILY SHOWERS DEVELOPING TO THE
NORTHWEST OF THE CWA. THIS IS EXPECTED TO GRADUALLY FILL IN AND
MOVE EAST THROUGH THE DAY AS THE FRONT GAINS MOMENTUM. ALL OF THE
HIGH RESOLUTION SHORT TERM GUIDANCE SUGGESTS THAT A LINE OF
CONVECTION WILL MOVE THROUGH NORTH TEXAS THROUGH THIS AFTERNOON
ALONG THE FRONT...HOWEVER THERE IS SOME DISCREPANCY AS TO HOW
INTENSE IT WILL BE. LATEST NAM IS MOST AGGRESSIVE WITH INSTABILITY
AND STILL INDICATES AN AXIS OF 700-1000J/KG OF OF CAPE ACROSS
NORTH TEXAS AND WEAKENS THE CAPPING AROUND 700MB. RUC SOUNDINGS
ARE NOT SO QUICK TO ERODE THE CAPPING AND INDICATE THAT DEEP
CONVECTION WILL BE HARD TO COME BY. GIVEN THE EXTENSIVE CLOUD
COVER AND ONGOING DRIZZLE TEND TO THINK THE LESS AGGRESSIVE RUC
MAY HAVE A BETTER HANDLE ON THINGS. WILL CONTINUE TO MENTION
THUNDERSTORMS THROUGH THE AFTERNOON...BUT OVERALL SEVERE WEATHER
THREAT MAY BE CONFINED TO A FEW ISOLATED CELLS. THIS IS ONE OF
THOSE SITUATIONS THOUGH WHERE A LITTLE EXTRA HEATING OR SLIGHTLY
MORE WEAKENING OF THE CAP COULD RESULT IN MORE WIDESPREAD SEVERE
CONVECTION SO IT IS WORTH WATCHING THROUGH THE AFTERNOON. ONLY
SOME MINOR TWEAKS TO POP/WEATHER WORDING THROUGH THE AFTERNOON
OTHERWISE NO MAJOR CHANGES TO THE CURRENT FORECAST.
DUNN
&&
.PREV DISCUSSION... /ISSUED 344 AM CST WED DEC 14 2011/
MOIST ISENTROPIC ASCENT WILL CONTINUE TODAY AS THE LOW LEVEL JET
REMAINS STRONG AND CONTINUES TO TRANSPORT RICH MOISTURE INTO THE
REGION. SOME INSTABILITY WILL WORK INTO THE WESTERN COUNTIES THIS
MORNING AND THEN SPREAD EASTWARD THIS AFTERNOON AND EVENING. THERE
IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WITH HAIL AND DAMAGING
WINDS DUE TO AN APPROACHING SHORTWAVE...A 90-100 KNOT JET ALOFT AND
400-1000 J/KG OF CAPE. BEST TIMING FOR SEVERE WILL BE MID/LATE
AFTERNOON OVER THE WESTERN HALF AND THIS EVENING FOR THE EASTERN
HALF. A COLD FRONT WILL SWING THROUGH NORTH TEXAS LATER TONIGHT
AND BRING COOLER NORTHERLY WINDS BACK TO THE REGION.
A STRONG SHORTWAVE WILL KICK OUT OF THE PERSISTENT SOUTHERN
CALIFORNIA UPPER LOW AND PASS OVER THE REGION THURSDAY EVENING.
HAVE HELD ONTO LOW POPS THURSDAY AND THURSDAY NIGHT AS MID LEVEL
LIFT MOVES ACROSS THE REGION. AS THE SHORTWAVE MIGRATES EAST OF THE
REGION...RAIN CHANCES WILL END FOR MOST OF THE CWA BUT LINGER
OVER THE SOUTHERN COUNTIES THROUGH FRIDAY. THERE WILL BE A BRIEF
LULL IN RAIN CHANCES ON SATURDAY...BUT THEY RETURN TO THE WESTERN
COUNTIES SATURDAY NIGHT AS THE MAIN UPPER LOW OVER SOUTHERN
CALIFORNIA BEGINS TO MOVE EAST. AS THE UPPER SYSTEM NEARS TEXAS...
RAIN CHANCES WILL INCREASE WEST TO EAST SUNDAY THROUGH
MONDAY...AND HAVE INCLUDED THUNDERSTORM POTENTIAL FOR MONDAY
MORNING. ANOTHER COLD FRONT WILL MOVE THROUGH THE REGION MONDAY
EVENING.
TEMPERATURES FOR THE MOST PART WILL BE SEASONAL WITH ABOVE NORMAL
CONDITIONS AHEAD OF TONIGHT/S COLD FRONT AND MONDAY/S COLD FRONT.
75
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 72 50 58 39 53 / 100 50 30 40 10
WACO, TX 74 50 57 43 54 / 80 50 40 60 10
PARIS, TX 72 53 64 42 53 / 80 70 30 50 10
DENTON, TX 69 46 58 36 51 / 100 40 30 30 10
MCKINNEY, TX 69 49 60 40 52 / 100 50 30 40 10
DALLAS, TX 71 51 58 40 54 / 100 50 40 40 10
TERRELL, TX 70 53 61 42 55 / 90 60 40 50 10
CORSICANA, TX 72 55 59 45 55 / 70 60 40 60 10
TEMPLE, TX 73 53 58 43 56 / 60 50 50 60 20
MINERAL WELLS, TX 71 43 55 34 51 / 100 20 30 30 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
316 PM CST WED DEC 14 2011
.TONIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
SHEARED VORT MAX STRETCHING FROM NORTHEAST NEW MEXICO TO EASTERN
NEBRASKA APPARENT IN 1945Z WATER VAPOR IMAGERY AND RUC ANALYSIS.
RAIN SPREAD BACK INTO SOUTHERN WI EARLY THIS AFTERNOON...SUPPORTED
BY 500MB VORT MAX PUSHING INTO SOUTH CENTRAL WI...WARM AIR ADVECTION
AND CONTINUED ISENTROPIC LIFT. OMEGA VALUES WILL ALSO INCREASE
BETWEEN NOW AND 7 PM AS WELL...PER RUC AND NAM MODEL SNDGS.
REGIONAL RADAR NOW ROUGHLY SHOWING DRY SLOT MOVING INTO CENTRAL
IOWA...CORRESPONDING TO THE CENTER OF SFC LOW PRESSURE. OBS STILL
SHOWING DRIZZLE IN THE VICINITY. SFC LOW WILL MOVE INTO NORTHEAST
IOWA AROUND 00Z...AND CLIP THE NORTHWEST FORECAST AREA AS IT MOVES
ACROSS CENTRAL WI AT 03Z. THE SFC TROUGH/COLD FRONT WILL THEN TREK
ACROSS SOUTHEAST WI FROM 05Z TO 09Z...USHERING IN COLDER AND DRIER
AIR...AS THE SFC LOW MOVES INTO EASTERN UPPER MICHIGAN. LOW LEVELS
WILL REMAIN MOIST BEHIND THE FRONT...BUT DRY OUT ALOFT...THUS
CAUSING DRIZZLE BEHIND THE DEPARTING LOW THROUGH AROUND 15Z/9AM THU
MORNING.
THE BAGGY PRESSURE GRADIENT OVER THE WESTERN FORECAST AREA WILL
ALLOW FOR AREAS OF DENSE FOG THROUGH LATE EVENING UNTIL THE COLD
FRONT COMES THROUGH AND THE WINDS INCREASE. DENSE FOG ADVY POSTED.
TEMPERATURES WILL KEEP RISING THROUGH THE EVENING...REACHING OUR
DAILY HIGH IN THE UPPER 40S/LOWER 50S AROUND MIDNIGHT. TEMPS WILL
GRADUALLY FALL THROUGH THE DAY THU...DROPPING DOWN TO AROUND
FREEZING FROM NW TO SE DURING THE AFTERNOON HOURS.
PRECIP IS EXPECTED TO END BY LATE THU MORNING...AND CLOUDS SHOULD
BREAK UP DURING THE AFTERNOON HOURS...BECOMING PARTLY CLOUDY BY
EVENING.
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE IS HIGH.
SKIES CONTINUE TO CLEAR OUT EARLY THURSDAY EVENING AS THE LOW
PULLS AWAY AND HIGH PRESSURE BUILDS IN. THINGS COOL DOWN...BUT
REMAIN AT OR SLIGHTLY ABOVE NORMAL.
.FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
A COUPLE OF WEAK MID LEVEL SHORT WAVES COME THROUGH THE FAST
NORTHWEST FLOW FRIDAY NIGHT AND AGAIN SATURDAY AFTERNOON. MOISTURE
BEGINS TO RETURN AND THERE IS SOME INDICATION WE COULD GET ENOUGH
COLUMN SATURATION TO SQUEEZE OUT A FEW FLAKES OF SNOW. HAVE
INTRODUCED A SLIGHT CHANCE OF LIGHT SNOW...BUT LITTLE OR NO
ACCUMULATION IS EXPECTED. THE GFS AND THE NAM ARE HINTING AT SOME
VERY LIGHT QPF THROUGH THIS PERIOD.
.SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM.
QUIET CONDITIONS EXPECTED THIS PERIOD AS WEAK RIDGING MOVES
THROUGH. TEMPS REMAIN AT OR ABOVE NORMAL.
.SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE IS LOW.
THERE IS MAJOR MODEL UNCERTAINTY FOR EARLY NEXT WEEK. AT ISSUE IS
WHETHER WE/LL SEE A LOW MOVE UP INTO THE GREAT LAKES AND GIVE US
RAIN...OR STAY WELL TO THE SOUTH AND KEEP US DRY...OR TAKE A
COMPROMISE OF THE TWO AND POSSIBLY GIVE US SOME ACCUMULATING SNOW.
THE GFS HAS MAINTAINED IT/S SOUTHERN DRY SOLUTION FOR US...THE
CANADIAN LOOKS FAIRLY WARM/RAINY WITH A LOW MOVING INTO THE
CENTRAL GREAT LAKES...WHILE THE ECMWF IS A COMPROMISER TAKING A
LOW THROUGH CENTRAL ILLINOIS/INDIANA. THE ECMWF WOULD BE COOLER
DURING THE PRECIP AND THIS COULD RESULT IN SOME ACCUMULATING
SNOW...NOTHING MAJOR AT THIS POINT. THE MODELS ARE HAVING A VERY
DIFFICULT TIME PHASING ENERGY FROM THE SOUTHERN AND NORTHERN
STREAMS. HAVE KEPT POPS IN THE CHC CATEGORY UNTIL WE GET A LITTLE
MORE CONSENSUS.
&&
.AVIATION/00Z TAFS/...SURFACE LOW PRESSURE WILL TRACK ACROSS
NORTHEAST IOWA...CENTRAL WI AND EASTERN UPPER MICHIGAN THROUGH
TONIGHT. BAGGY PRESSURE GRADIENT BENEATH THE SFC LOW WILL COVER
SOUTH CENTRAL WI...ALLOWING AREAS OF DENSE FOG TO DEVELOP/PERSIST
THROUGH THE EVENING.
RAIN ASSOCIATED WITH THE 500MB SHORTWAVE...850MB WARM AIR
ADVECTION...AND STRONG OMEGA WILL DIMINISH AS THE SFC LOW COMES
OVERHEAD...AS THE DRY SLOT HITS THE REGION.
COLD FRONTAL PASSAGE WILL OCCUR BETWEEN 05Z AND 08Z TONIGHT. STRONG
COLD ADVECTION THU AM WILL IMPROVE CONDITIONS BY RAISING THE
CEILINGS AND IMPROVING VISIBILITY. WIND GUSTS TO 30 KNOTS
POSSIBLE...ESPECIALLY AT MKE. CLOUDS SHOULD SCATTER OUT DURING THU
AFTERNOON.
&&
.MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT FROM 6 PM TNT THROUGH
9 PM THU EVENING. BREEZY SSWLY WINDS AND HIGH WAVES WILL DEVELOP
THIS EVENING WITH A COLD FRONTAL PASSAGE EXPECTED TO SHIFT THE WINDS
TO THE WEST BY 09Z TNT. STRONG COLD ADVECTION WILL COMBINE WITH THE
RELATIVELY MILD LAKE MI WATER TEMPS TO PRODUCE UNSTABLE CONDITIONS
IN THE LOW LEVEL ATMOSPHERE. THIS WILL ENHANCE THE ALREADY MODERATE
WIND FIELD WITH WIND GUSTS EXPECTED TO REACH 30 KTS. THE WAVES WILL
DECREASE AFTER COLD FROPA DUE TO THE WLY COMPONENT OF THE WIND AND
THEREFORE LESS FETCH TO GENERATE WAVES. HOWEVER...HIGH WAVES WILL
STILL OCCUR OVER THE OPEN WATERS OF LAKE MI. THE WINDS WILL SUBSIDE
BY LATE THU EVENING AS A LARGE HIGH PRESSURE AREA APPROACHES FROM
THE WEST.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ046-047-056-
057-062-063-067-068.
LM...SMALL CRAFT ADVISORY UNTIL 9 PM CST THURSDAY FOR LMZ643>646.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...MRC
THURSDAY NIGHT THROUGH WEDNESDAY...DAVIS