Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/28/14
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1001 AM PDT Wed Mar 26 2014
.Synopsis...
Significant mountain snow and gusty winds are likely with
good potential for isolated thunderstorms today...some possibly
strong storms. Wet and cooler weather will continue through the
weekend.
&&
.Updated Discussion...
Next wave of precip is spreading into the Sierra as the next
batch of short-wave energy rotates inland. Forecast soundings
indicate showers and potential for some thunderstorms today in the
valley. Buoyancy or CAPE is only around 100 J/kg at most from the
NAM and RUC. But the HRRR was showing between 100-200 J/kg. The
CAPE layer is relatively shallow. But, that is normal for here.
The interesting thing to note is the shear values. The 0-1 km
shear is anywhere from 12 to 20 m/s while the 0-6 km shear is
from 35 to 55 m/s, with the strongest areas between Sacramento and
Red Bluff. The significance of these shear profiles are that they
are very favorable for rotating updrafts if individual cells are
able to develop. Similar to yesterday, it will be a waiting game
today to see if enough clearing develops behind the main area of
showers that will move across the area during the morning.
The back of edge of the wave/clouds are near the coast.
Orographic flow may keep clouds are coastal range, but shadowed
areas in the valley may see enough clearing later. We already see
evidence of some thinning clouds in the western valley.
We are not making any major changes to the snow amounts and the
Winter Storm Warning. The next wet system is forecast to drop
southward through the region Saturday. JClapp
&&
.Extended Discussion (Sunday through Wednesday)
Models show weak ridging over the state on Sunday but WAA and
weak lift could promote some continued light overrunning
precipitation mainly north of the Sacramento area. Daytime highs
will range from a little below normal to the north where cloud
cover will be more extensive to a little above normal to the
south. The next in a series of Pacific storm systems is forecast
fairly consistently by the extended models to move into NORCAL by
Monday afternoon bringing a good chance of precipitation to the
entire CWA. Relatively low snow levels are expected with this cold
system. Moisture feed into this system is relatively modest with
predicted TPW values of only around .8 inches. Therefore...only
expecting this storm to be a moderate precipitation producer. The
upper low is forecast to push through NORCAL on Tuesday bringing a
continued shower threat and cooler than normal daytime
temperatures. Latest model runs push upper ridging over the west
coast by Wednesday of next week. If this model trend continues
then will need to reduce precipitation chances in current grid
package.
&&
.Aviation...
Another day of showers and thunderstorms today with an unstable
airmass behind last evenings cold frontal passage. VFR with local
MVFR in the Valley today, with the best chance of MVFR for the
Northern Sac Valley. Over the mountains, IFR ceilings and
visibilities with snow down to 4500 feet. Improving conditions for
the Valley overnight, with improving conditions for the mountains
by 18z. -DVC
&&
.STO Watches/Warnings/Advisories...
Winter Storm Warning until 11 am pdt Thursday above 5000 feet in
the west slope northern Sierra Nevada...western Plumas
county/Lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
348 AM EDT WED MAR 26 2014
.SYNOPSIS...
AN INTENSE LOW PRESSURE SYSTEM WILL MOVE INTO THE CANADIAN MARITIMES
LATER TODAY AND TONIGHT. MEANWHILE HIGH PRESSURE BUILDS INTO OUR
REGION LATER TODAY AND TONIGHT, THEN SHIFTS OFFSHORE THURSDAY. LOW
PRESSURE TRACKING ACROSS THE GREAT LAKES SHOULD PULL A WARM FRONT
NORTH ACROSS OUR AREA THURSDAY NIGHT, THEN A COLD FRONT SETTLES INTO
OUR AREA LATER FRIDAY. THIS FRONT MAY STALL AS ANOTHER LOW TRACKS
ALONG IT SATURDAY, BEFORE SHIFTING TO OUR EAST SATURDAY NIGHT INTO
SUNDAY. HIGH PRESSURE RETURNS FOR LATER SUNDAY INTO MONDAY, THEN THE
NEXT COLD FRONT MAY ARRIVE LATE MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ALL WINTER WARNINGS AND ADVISORIES DISCONTINUED AT 2AM. WE`LL UPDATE
THE SNOWFALL REPORTS THOROUGHLY BETWEEN 430 AM AND 11 AM AS TIME
AVAILS.
STORM BASICALLY DONE FOR US EXCEPT MAYBE ANOTHER ONE QUARTER TO ONE
HALF INCH ALONG THE COAST.
WE`VE ADDED A SECONDARY SNOW SHOWER BAND TO THE I95 REGION WESTWARD
IN THE 07Z-11Z TIME FRAME PER THE LATEST RAP AND NAM MODELS. THIS
WILL BE A WINDEX EVENT WITH MOIST UNSTABLE LOW LEVEL LAPSE RATES
SUDDENLY DRYING-STABILIZING AS STRONG NW WINDS DEVELOP NEAR SUNRISE.
SEE THE RADAR PROGRESSION FROM VCNTY KBGM TO KUNV IN CENTRAL PA.
TODAY DURING THE DAYLIGHT HOURS...WIND ADVISORY MIDDLESEX COUNTY
SOUTHEASTWARD INTO COASTAL OCEAN AND WE MAY YET EXPAND THAT TO MUCH
OF COASTAL NJ AND DE AT 330 AM...STILL CONSIDERING. RIGHT NOW WE`LL
GO WITH ISOLATED 40 KT GUSTS AND LEAVE IT A NON ADVISORY SITN.
OTRW...ONCE THE DRY AIR ARRIVES AND STABILIZES THE CONSIDERABLE
MORNING CLOUDINESS WILL EVAPORATE TO REVEAL BRIGHT SUNNY SKIES
THIS AFTN WITH GUSTY NW WINDS 35 TO 45 MPH AND STRONG CAA ALOFT.
ISOLATED GUSTS TO 50 MPH EXPECTED. TEMPS WERE PRIMARILY THE WARMER
GFS VALUES. NAM SEEMS TO HAVE HAD A SLIGHT COLD BIAS FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
**RECORD BREAKING COLD IN OUR AREA TONIGHT**
TONIGHT...HIGH PRESSURE WILL MOVE IN FROM THE WEST OVERNIGHT.
CLEAR SKIES TILL A FEW CIRRUS AT SUNRISE. GUSTY NW WINDS 20-25 MPH
AT 8 PM DIMINISH AND DECOUPLE. PRESUMING REMAINING SNOW COVER SE
NJ..DE AND MD...WE SHOULD SEE RECORD BREAKING MINS IN THE TEENS
THERE AND EVEN RECORDS POSSIBLE ELSEWHERE THROUGH OUR FCST AREA
EXCEPT NOT AT KMPO. PLEASE SEE THE CLIMATE SECTION OF THIS PRODUCT
FOR THE LISTING OF THE RECORDS. THIS FCST USED THE WARMER OF THE
AVBL 00Z/26 NCEP MOS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE OVERALL SYNOPTIC SETUP IS COMPRISED OF SOME RIDGING IN THE EAST
THURSDAY INTO FRIDAY, THEN A TROUGH IN THE PLAINS AMPLIFIES EASTWARD
WITH THE RIDGE AMPLIFYING OFF THE EAST COAST. THE SHARPENING TROUGH
SHIFTS OFF THE EAST COAST LATER IN THE WEEKEND, THEN BRIEF RIDGING
ARRIVES BEFORE THE NEXT UPPER-LEVEL TROUGH ARRIVES FOR TUESDAY. THIS
ADVERTISED PATTERN WILL ALLOW WARMER AIR TO ARRIVE OVERALL DESPITE
SEVERAL TIMES OF UNSETTLED WEATHER. THE SATURDAY SYSTEM IN
PARTICULAR HAS THE POTENTIAL TO PRODUCE AN AREA OF HEAVY RAIN ACROSS
THE CWA. WE USED A MODEL BLEND WITH CONTINUITY THURSDAY INTO
SATURDAY, THEN BLENDED IN THE 00Z WPC GUIDANCE THEREAFTER.
FOR THURSDAY...AS RIDGING ARRIVES ALONG THE EAST COAST, THE SURFACE
HIGH OVER THE AREA WILL BE SHIFTING OFFSHORE. THIS WILL ALLOW FOR A
RATHER COLD START TO THE DAY, HOWEVER A DEVELOPING SOUTHWESTERLY
FLOW ON THE BACKSIDE OF THE SURFACE HIGH WILL YIELD TO A MODERATING
AIRMASS. AS THE WAA GETS UNDERWAY AND A WARM FRONT ORGANIZES TO OUR
SOUTHWEST, AT LEAST SOME INCREASE IN HIGH CLOUDS IS ANTICIPATED
THROUGH THE DAY AND AT NIGHT. A CONTINUED SOUTHERLY FLOW AT NIGHT
WILL RESULT IN HIGHER MINIMUM TEMPERATURES. THE INCREASING WAA ALONG
WITH THE ADVANCEMENT OF THE WARM FRONT AT NIGHT MAY RESULT IN SOME
LIGHT PRECIPITATION ARRIVING FROM THE WEST TOWARD DAYBREAK FRIDAY.
OVERALL THOUGH WITH THE SLOWER RESPONSE IN THE SURFACE DEW POINTS,
IT LOOKS LIKE MUCH OF THE CWA REMAINS DRY. HOWEVER, PERHAPS A LOW
CHC FOR SOME MIXED PRECIPITATION ARRIVING FAST ENOUGH INTO THE
POCONO REGION.
FOR FRIDAY...LOW PRESSURE IS FORECAST TO TRACK ACROSS THE NORTHERN
GREAT LAKES AND ACROSS SOUTHEASTERN CANADA. THE STRONGER
SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE WILL MAINTAIN WAA AND
THEREFORE A WARM FRONT SHOULD LIFT TO OUR NORTH. PRIOR TO THIS
HAPPENING THROUGH, FORECAST SOUNDINGS ACROSS THE FAR NORTHWEST ZONES
AND ESPECIALLY THE POCONOS SHOW THE LOW-LEVEL COLD AIR HANGING ON.
THIS MAY RESULT IN A LITTLE WINTRY MIX OR FREEZING RAIN AT THE
ONSET. HOWEVER GIVEN THE STRENGTH OF THE FLOW, WAA AND ALSO THE
SURFACE LOW TRACKING TO OUR NORTH, ANY FROZEN/FREEZING PRECIPITATION
IS EXPECTED TO BE BRIEF. THE ASSOCIATED COLD FRONT WILL THEN MOVE
INTO OUR AREA DURING THE AFTERNOON AND EVENING. AS ADDITIONAL ENERGY
DEVELOPS ALONG THE TAIL END OF THE FRONT, THE BOUNDARY SHOULD TEND
TO SLOW AND STALL IN OUR VICINITY AT NIGHT. THERE LOOKS TO BE GOOD
FRONTAL FORCING FOR A TIME AS IT ENTERS OUR CWA, THEREFORE SHOWERS
SHOULD BE WIDESPREAD. THE PW VALUES ARE FORECAST TO SURGE TO NEAR AN
INCH AHEAD OF THE FRONT AND THEREFORE SOME DOWNPOURS WILL BE
POSSIBLE. THE SHOWERS SHOULD TAPER OFF AT NIGHT FOR A TIME AS THE
BOUNDARY SETTLES SOUTHWARD AND A SPLIT OCCURS BETWEEN THE LARGE
SCALE LIFT.
FOR SATURDAY AND SUNDAY...LOW PRESSURE WILL MOVE THROUGH THE
TENNESSEE AND OHIO VALLEYS EARLY SATURDAY, THEN SLIDE TOWARD OUR
AREA. THIS LOW WILL TRACK ALONG THE STALLED FRONTAL BOUNDARY DURING
THE DAY, THEN SHIFT OFF THE COAST LATER AT NIGHT. THE UPPER-LEVEL
TROUGH IS FORECAST TO AMPLIFY QUITE A BIT AS IT APPROACHES THE EAST
COAST, AND IT MAY ACTUALLY CLOSE OFF. THIS WOULD PROVIDE AMPLE LIFT
ACROSS THE AREA AND RESULT IN PERIODS OF RAIN. IT APPEARS THE
SURFACE LOW TRAVERSES OUR CWA SATURDAY NIGHT. THE PW VALUES ARE
FORECAST TO INCREASE WITH THIS SYSTEM INTO THE RANGE OF ABOUT
1.0-1.3 INCHES. THIS COMBINED WITH AMPLE LIFT WILL LEAD TO THE
POTENTIAL FOR SOME HEAVY RAIN TO OCCUR, POTENTIALLY LEADING TO AT
LEAST SOME POOR DRAINAGE FLOODING. WHILE SOME ELEVATED INSTABILITY
CANNOT BE RULED OUT, WE ARE THINKING THAT ANY THUNDER WOULD BE
ISOLATED AND THEREFORE IT WAS NOT INCLUDED ATTM. FOR SUNDAY, THE
ENTIRE SYSTEM IS FORECAST TO BE EXITING TO OUR EAST WITH ANY RAIN
PROBABLY ENDING EARLY. HOWEVER, IF IT BECOMES CLOSED OFF IT MAY BE
SLOWER TO CLEAR OUT OF OUR CWA AND SOME RAIN MAY LINGER LONGER
SUNDAY. AS OF NOW, WE LEANED MORE TOWARD WPC GUIDANCE AND KEPT SOME
LOW CHC POPS. A RIDGE BEGINS TO MOVE IN LATER IN THE DAY AND
ESPECIALLY AT NIGHT ALONG WITH HIGH PRESSURE AT THE SURFACE.
FOR MONDAY AND TUESDAY...HIGH PRESSURE SLIDES TO OUR SOUTH AND EAST
MONDAY, THEN THE NEXT LOW PRESSURE SYSTEM AND COLD FRONT ARRIVES
THEREAFTER. THIS ALSO LOOKS LIKE A SURFACE LOW DEVELOPING ALONG A
COLD FRONT FROM THE MISSOURI RIVER VALLEY EASTWARD MONDAY, THEN THIS
MOVES ACROSS OUR AREA LATE MONDAY NIGHT AND TUESDAY. THERE IS SOME
UNCERTAINTY WITH THE TIMING AND STRENGTH OF THIS SYSTEM, THEREFORE
WENT FAIRLY CLOSE TO WPC GUIDANCE.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR INTERIOR BUT MVFR CONDS IN LEFTOVER SNOW ALONG
THE COAST BECOMES VFR BY 10Z. A BAND OF MVFR CONDS SNOW SHOWERS
SHOULD CROSS KRDG/KABE AROUND 10-11Z AND MAY REACH KPHL AROUND
12Z. NW WINDS INCREASE WITH GUSTS 25-35 DEVELOPING NEAR 12Z.
CONFIDENCE HIGH.
TODAY AFTER 12Z...VFR. LINGERING FLURRIES POSSIBLE TIL 16Z WITH SCT-
BKN AOA 4000 FT THEN VFR MOSTLY CLEAR THIS AFTN. GUSTY NW WINDS
33-40 KTS FROM THE GET GO AT 12Z. CONFIDENCE HIGH.
TONIGHT...VFR CLEAR. GUSTY NORTHWEST WINDS 20-30 KT DURING THE
EVENING...DIMINISHING OVERNIGHT. CONFIDENCE HIGH.
OUTLOOK...
THURSDAY...VFR. SOUTH TO SOUTHWEST WINDS 10 TO 15 KNOTS. THE CLOUDS
INCREASE AT NIGHT WITH THE ADVANCEMENT OF A WARM FRONT.
FRIDAY...VFR TO START, THEN LOWERING TO MVFR /POSSIBLY IFR/ AS
SHOWERS ARRIVE FROM WEST TO EAST AHEAD OF A COLD FRONT. THIS FRONT
SHOULD SLOW OR STALL IN OUR VICINITY AT NIGHT AS LOW PRESSURE
DEVELOPS ALONG THE TAIL END OF IT. SOUTHWESTERLY WINDS 10 TO 15
KNOTS, THEN DIMINISHING AT NIGHT AND TURNING TO THE NORTHWEST.
SATURDAY...SUB-VFR WITH PERIODS OF RAIN AS LOW PRESSURE SLOWLY MOVES
ACROSS THE AREA. THE RAIN SHOULD START TO TAPER OFF LATE AT NIGHT.
LIGHT NORTHEAST WINDS, BECOMING NORTHERLY AT NIGHT.
SUNDAY...THERE MAY BE SUB-VFR CONDITIONS EARLY WITH SOME SHOWERS,
OTHERWISE VFR. OUR CONFIDENCE IS LOWER DUE TO HOW FAST THE SATURDAY
SYSTEM SHIFTS TO THE EAST. GENERALLY NORTHERLY WINDS 10 TO 15 KNOTS.
&&
.MARINE...
GLW CONTINUES AS PREVIOUSLY ADVERTISED. NW WIND GUSTS 35-45KT TODAY
DIMINISH TONIGHT.
OUTLOOK...
THURSDAY...SUB-ADVISORY CONDITIONS ARE ANTICIPATED AS WARMER AIR
STARTS TO ADVECT OVER THE COOLER WATERS WITH THE ADVANCEMENT OF A
WARM FRONT LATE. THE SEAS ARE ALSO EXPECTED TO SUBSIDE.
FRIDAY...THE WINDS AND SEAS MAY INCREASE ENOUGH TO REACH SMALL CRAFT
ADVISORY CRITERIA AHEAD OF A COLD FRONT.
SATURDAY AND SUNDAY...THE CONDITIONS SHOULD LOWER TO BELOW ADVISORY
CRITERIA SATURDAY, HOWEVER SHOULD THEN INCREASE TO SMALL CRAFT
ADVISORY CONDITIONS EITHER LATER SATURDAY NIGHT OR SUNDAY. THIS WILL
BE DUE TO LOW PRESSURE MOVING NEARLY RIGHT OVER OUR AREA, HOWEVER
THE DETAILS STILL NEED TO BE IRONED OUT.
&&
.CLIMATE...
HERE ARE THE DAILY RECORD SNOWFALL AT OUR CLIMO BIG 4:
MARCH 25TH MARCH 26TH
ATLANTIC CITY 2.0 IN 2013 0.1 IN 2001
BOTH THE ABOVE WERE RECORDS OR RECORD EQUALING AND THE RER HAS
POSTED.
PHILADELPHIA SEASONAL SNOW TOTAL NOW 68.0...STILL #2 BEHIND THE 78.7
OF THE 2009-2010 WINTER.
ALLENTOWN SEASONAL SNOW TOTAL NOW 67.8...RANKED #3 BEHIND THE 75.4
OF 1993-94 AND 71.4 INCHES OF 1995-1996
ATLANTIC CITY SEASONAL SNOW TOTAL NOW 43.6 AND RANKED AT LEAST
NUMBER 5. WE`LL UPDATE THIS BY 430 AM.
MINIMUM TEMPERATURES ON THE 27TH...THERE IS A GOOD CHANCE THAT
ALL OF THESE SITES LISTED BELOW EXCEPT MOUNT POCONO WILL BE WITHIN
2 DEGREES OF RECORD: IT WILL HELP IF THERE IS STILL SNOW COVERING
THE GROUND AT DAYBREAK THURSDAY.
RECORD LOWS FOR THURSDAY MORNING.
ACY 16 2001
PHL 21 1894
ILG 22 2001 1975 AND 1951
ABE 15 2001
TTN 20 1894
GED 18 1951
RDG 19 2001
MPO 6 1975 IS NOT WITHIN REACH.
AS FOR THE MONTHLY AVERAGES...IT LOOKS LIKE PHL TEMPS WILL BE
AVERAGING AT LEAST 4 DEGREES BELOW NORMAL.
&&
.EQUIPMENT...
WE`VE HAD PROBLEMS SINCE LAST EVENING WITH OUR WEB SITE UPDATING
PROPERLY AND IT PROBABLY WONT BE FIXED UNTIL ABOUT 7 OR 8AM. IT
MAY BE TIED TO AN EASTERN REGION ROUTER ISSUE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WIND ADVISORY FROM 8 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NJZ012>014-020-026.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...GORSE/MEOLA
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
301 AM EDT WED MAR 26 2014
.SYNOPSIS...
VERY STRONG LOW PRESSURE WELL EAST OF THE MID ATLANTIC COAST WAS
INTENSIFYING VERY RAPIDLY AS IT HEADS FOR NOVA SCOTIA LATE TODAY.
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT AND THURSDAY. A
COLD FRONT WILL MOVE INTO THE AREA ON FRIDAY AND STALL. LOW
PRESSURE WILL MOVE ALONG THE FRONT, PUSHING A WARM FRONT THROUGH
THE AREA ON SATURDAY AND THEN CROSSING THE REGION SATURDAY NIGHT.
HIGH PRESSURE WILL RETURN FOR SUNDAY AND MONDAY. ANOTHER AREA OF
LOW PRESSURE WILL MOVE TOWARD THE REGION ON TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
ALL WINTER WARNINGS AND ADVISORIES DISCONTINUED AT 2AM. WE`LL UPDATE
THE SNOWFALL REPORTS THOROUGHLY BETWEEN 430 AM AND 11 AM AS TIME
AVAILS.
STORM BASICALLY DONE FOR US EXCEPT MAYBE ANOTHER ONE QUARTER TO ONE
HALF INCH ALONG THE COAST.
WE`VE ADDED A SECONDARY SNOW SHOWER BAND TO THE I95 REGION WESTWARD
IN THE 07Z-11Z TIME FRAME PER THE LATEST RAP AND NAM MODELS. THIS
WILL BE A WINDEX EVENT WITH MOIST UNSTABLE LOW LEVEL LAPSE RATES
SUDDENLY DRYING-STABILIZING AS STRONG NW WINDS DEVELOP NEAR SUNRISE.
SEE THE RADAR PROGRESSION FROM VCNTY KBGM TO KUNV IN CENTRAL PA.
TODAY DURING THE DAYLIGHT HOURS...WIND ADVISORY MIDDLESEX COUNTY
SOUTHEASTWARD INTO COASTAL OCEAN AND WE MAY YET EXPAND THAT TO MUCH
OF COASTAL NJ AND DE AT 330 AM...STILL CONSIDERING. RIGHT NOW WE`LL
GO WITH ISOLATED 40 KT GUSTS AND LEAVE IT A NON ADVISORY SITN.
OTRW...ONCE THE DRY AIR ARRIVES AND STABILIZES THE CONSIDERABLE
MORNING CLOUDINESS WILL EVAPORATE TO REVEAL BRIGHT SUNNY SKIES
THIS AFTN WITH GUSTY NW WINDS 35 TO 45 MPH AND STRONG CAA ALOFT.
ISOLATED GUSTS TO 50 MPH EXPECTED. TEMPS WERE PRIMARILY THE WARMER
GFS VALUES. NAM SEEMS TO HAVE HAD A SLIGHT COLD BIAS FOR TODAY.
&&
.SHORT TERM /TONIGHT/...
**RECORD BREAKING COLD IN OUR AREA TONIGHT**
TONIGHT...HIGH PRESSURE WILL MOVE IN FROM THE WEST OVERNIGHT.
CLEAR SKIES TILL A FEW CIRRUS AT SUNRISE. GUSTY NW WINDS 20-25 MPH
AT 8 PM DIMINISH AND DECOUPLE. PRESUMING REMAINING SNOW COVER SE
NJ..DE AND MD...WE SHOULD SEE RECORD BREAKING MINS IN THE TEENS
THERE AND EVEN RECORDS POSSIBLE ELSEWHERE THROUGH OUR FCST AREA
EXCEPT NOT AT KMPO. PLEASE SEE THE CLIMATE SECTION OF THIS PRODUCT
FOR THE LISTING OF THE RECORDS. THIS FCST USED THE WARMER OF THE
AVBL 00Z/26 NCEP MOS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THURSDAY...A COLD START TO THE DAY AS THE NORTHWEST FLOW CONTINUES.
THE HIGH PRESSURE CENTERS ITSELF OVER THE CAROLINAS AND THEN MOVES
OFFSHORE LATER THURSDAY. THE NORTHWEST FLOW WILL BECOME MORE
WESTERLY AND THEN SOUTHWESTERLY, ALLOWING SOME WARMER AIR TO MOVE
INTO THE REGION. IN ADDITION, WE WILL START TO HAVE MORE CLOUDS MOVE
IN AS THE WARM AIR ADVECTION INCREASES.
FRIDAY...LOW PRESSURE MOVES ACROSS THE NORTHERN GREAT LAKES THURSDAY
NIGHT AND CONTINUES TO MOVE INTO EASTERN CANADA ON FRIDAY. THE
ASSOCIATED COLD FRONT WILL APPROACH FROM THE WEST AND CROSS INTO THE
AREA DURING THE AFTERNOON/EVENING ON FRIDAY. SHOWERS WILL DEVELOP IN
ADVANCE OF THE APPROACHING FRONT AND IT IS LOOKING TO BE KIND OF A
WET DAY ACROSS OUR AREA. WARM AIR WILL CONTINUE TO BE IN THE AREA
AND TEMPERATURES WILL BE ABOVE NORMAL AND SHOULD BE ABLE TO REACH
INTO THE UPPER 50S TO LOWER, MAYBE EVEN SOME MID, 60S. THE FRONTAL
BOUNDARY LOOKS TO STALL ACROSS OR NEAR OUR AREA ON FRIDAY NIGHT.
SATURDAY...LOW PRESSURE WILL MOVE THROUGH THE TENNESSEE AND OHIO
VALLEYS EARLY ON SATURDAY AND MOVE TOWARD OUR AREA. THIS LOW WILL
TRAVERSE THE PREVIOUS FRONTAL BOUNDARY AND AS IT APPROACHES THE
REGION, IT WILL PUSH A WARM FRONT NORTHWARD THROUGH OUR AREA. THE
LOW WILL CROSS THE REGION ON SATURDAY NIGHT. PRECIPITABLE WATER
VALUES INCREASE THROUGH THIS TIME AND RANGE AROUND 1.0-1.3 INCHES.
THE POTENTIAL FOR SOME HEAVY RAIN WILL BE THERE AS WELL AS SOME POOR
DRAINAGE FLOODING. NOT SEEING ALL THAT MUCH INSTABILITY WITH THIS
SYSTEM AS IT MOVES THROUGH AND HAVE LOW CONFIDENCE IN ANY THUNDER
OCCURRING. WE THINK THUNDER WOULD BE VERY ISOLATED AND HAVE LEFT IT
OUT OF THE FORECAST AT THIS TIME. THIS SYSTEM WILL BEAR SOME
WATCHING IN THE COMING DAYS.
SUNDAY...THINGS START TO CLEAR OUT DURING THE MORNING HOURS AS HIGH
PRESSURE STARTS TO BUILD IN FROM THE WEST. TEMPERATURES WILL BE A
BIT COOLER THAN SATURDAY BUT WILL REMAIN CLOSER TO NORMAL.
MONDAY...WITH THE HIGH REMAINING NEAR THE AREA, WE SHOULD HAVE A
MODERATE AND DRY DAY ACROSS THE REGION. A STRONG MID-LEVEL SHORTWAVE
WILL ROTATE THROUGH THE REGION AND COULD CAUSE SOME GUSTY WINDS.
TUESDAY...LOW PRESSURE DEVELOPS OVER THE TENNESSEE VALLEY AND PUSHES
TO THE EAST...CROSSING THE DELMARVA TUESDAY NIGHT. PLENTY OF
UNCERTAINTY WITH THE TIMING AND STRENGTH OF THIS SYSTEM SO STAY
TUNED FOR DETAILS OVER THE NEXT WEEK.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR INTERIOR BUT MVFR CONDS IN LEFTOVER SNOW ALONG
THE COAST BECOMES VFR BY 10Z. A BAND OF MVFR CONDS SNOW SHOWERS
SHOULD CROSS KRDG/KABE AROUND 10-11Z AND MAY REACH KPHL AROUND
12Z. NW WINDS INCREASE WITH GUSTS 25-35 DEVELOPING NEAR 12Z.
CONFIDENCE HIGH.
TODAY AFTER 12Z...VFR. LINGERING FLURRIES POSSIBLE TIL 16Z WITH SCT-
BKN AOA 4000 FT THEN VFR MOSTLY CLEAR THIS AFTN. GUSTY NW WINDS
33-40 KTS FROM THE GET GO AT 12Z. CONFIDENCE HIGH.
TONIGHT...VFR CLEAR. GUSTY NORTHWEST WINDS 20-30 KT DURING THE
EVENING...DIMINISHING OVERNIGHT. CONFIDENCE HIGH.
OUTLOOK...
THURSDAY...VFR CONDITIONS EXPECTED. SOUTH TO SOUTHWEST WINDS WILL
REMAIN GUSTY WITH GUSTS UP TO 20 KNOTS.
FRIDAY...VFR CONDITIONS EXPECTED TO START WITH DETERIORATING
CONDITIONS TO MVFR, POSSIBLY IFR, AS PRECIPITATION MOVES INTO THE
REGION. SOUTHWESTERLY WINDS AROUND 10 KNOTS.
SATURDAY...MVFR TO IFR CONDITIONS WILL CONTINUE AS A FRONTAL SYSTEM
MOVES THROUGH THE REGION. LIGHT WINDS.
SUNDAY...MVFR CONDITIONS EARLY SHOULD BE IMPROVING TO VFR
CONDITIONS. NORTHERLY WINDS AROUND 10 TO 15 KNOTS.
&&
.MARINE...
GLW CONTINUES AS PREVIOUSLY ADVERTISED. NW WIND GUSTS 35-45KT TODAY
DIMINISH TONIGHT.
OUTLOOK...
THURSDAY...SUB-ADVISORY CONDITIONS ARE EXPECTED.
FRIDAY...WINDS AND SEAS INCREASE AND SMALL CRAFT ADVISORY CONDITIONS
WILL PROBABLY OCCUR.
SATURDAY AND SUNDAY...SMALL CRAFT CONDITIONS WILL CONTINUE THROUGH
THE WEEKEND AS A LOW PRESSURE SYSTEM MOVES THROUGH THE AREA.
&&
.CLIMATE...
HERE ARE THE DAILY RECORD SNOWFALL AT OUR CLIMO BIG 4:
MARCH 25TH MARCH 26TH
ATLANTIC CITY 2.0 IN 2013 0.1 IN 2001
BOTH THE ABOVE WERE RECORDS OR RECORD EQUALING AND THE RER HAS
POSTED.
PHILADELPHIA SEASONAL SNOW TOTAL NOW 68.0...STILL #2 BEHIND THE 78.7
OF THE 2009-2010 WINTER.
ALLENTOWN SEASONAL SNOW TOTAL NOW 67.8...RANKED #3 BEHIND THE 75.4
OF 1993-94 AND 71.4 INCHES OF 1995-1996
ATLANTIC CITY SEASONAL SNOW TOTAL NOW 43.6 AND RANKED AT LEAST
NUMBER 5. WE`LL UPDATE THIS BY 430 AM.
MINIMUM TEMPERATURES ON THE 27TH...THERE IS A GOOD CHANCE THAT
ALL OF THESE SITES LISTED BELOW EXCEPT MOUNT POCONO WILL BE WITHIN
2 DEGREES OF RECORD: IT WILL HELP IF THERE IS STILL SNOW COVERING
THE GROUND AT DAYBREAK THURSDAY.
RECORD LOWS FOR THURSDAY MORNING.
ACY 16 2001
PHL 21 1894
ILG 22 2001 1975 AND 1951
ABE 15 2001
TTN 20 1894
GED 18 1951
RDG 19 2001
MPO 6 1975 IS NOT WITHIN REACH.
AS FOR THE MONTHLY AVERAGES...IT LOOKS LIKE PHL TEMPS WILL BE
AVERAGING AT LEAST 4 DEGREES BELOW NORMAL.
&&
.EQUIPMENT...
WE`VE HAD PROBLEMS SINCE LAST EVENING WITH OUR WEB SITE UPDATING
PROPERLY AND IT PROBABLY WONT BE FIXED UNTIL ABOUT 7 OR 8AM. IT
MAY BE TIED TO AN EASTERN REGION ROUTER ISSUE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WIND ADVISORY FROM 8 AM THIS MORNING TO 6 PM EDT THIS EVENING
FOR NJZ012>014-020-026.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...DRAG/MEOLA 3A
NEAR TERM...DRAG 3A
SHORT TERM...DRAG 3A
LONG TERM...MEOLA
AVIATION...DRAG/MEOLA 3A
MARINE...DRAG/MEOLA 3A
CLIMATE...3A
EQUIPMENT...3A
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
349 PM CDT Wed Mar 26 2014
...Updated Short Term section...
.SHORT TERM...(This evening through Thursday)
ISSUED AT 348 PM CDT WED MAR 26 2014
Main challenge in the forecast tonight will be advisory level wind
speeds and precipitation chances. Today`s wave of precipitation that
grazed southwest Kansas (affecting south-central Kansas) was moving
out late this afternoon, however quick on its heels was another
potent upper tropospheric jet streak. This was already leading to
enhancement in mid and upper level cloud across Colorado. A few
showers and and isolated lightning strike or two will form across
the dry low level airmass of southeastern/east-central Colorado. A
few of these convective elements will move east into far southwest
Kansas this evening, however the real-estate of very limited
convective instability is quite narrow, so it will be extremely
difficult for any of these surface-based showers/isolated
thunderstorm to thrive much past sunset. In fact, the latest runs of
the 3km HRRR model suggest a dissipation of any surface based
activity not long after 00Z.
Surface winds are expected to back around or shortly after 00Z to
the south-southeast ahead of the dryline, and this will allow low
level moisture to pull back west, and widespread low clouds should
form. Light fog may also develop along and east of Highway 283,
however we will keep fog out of the grids for now, as the duration
of low clouds will be limited as winds begin to veer with the low
moving east around or shortly after 06Z.
On Thursday, we will be looking at another fairly windy day behind
the cold front passage, however the gradient behind the low will not
be as intense as we saw ahead of the low today, despite some deeper
mixing to help boost the surface winds. The forecast of 20 to 25
knots sustained in the late morning to early afternoon look pretty
good, however, these winds may need to be increased a bit
approaching yet another wind advisory issuance, perhaps. The
midnight shift will have to look at this closer (especially farther
north toward the I-70 corridor). The airmass behind the front will
have substantial downslope modification, so we will actually see
warmer temperatures tomorrow than what we saw today east of highway
283 (given all the clouds and light rain in this area today). Late
in the afternoon, there is the potential for some virga showers
developing across far west-central KS near the Colorado border as
convective temperature is reached given very chilly mid-level
temperatures (500mb temps of down to -25C and 700mb temps of around
-5C).
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 115 PM CDT WED MAR 26 2014
The extended period will be characterized by a progressive upper
level westerly flow over central North America. Low amplitude
shortwave troughs will periodically move east over the United States
through the period. The first shortwave during this period will move
out over the central High Plains late Thursday night into Friday
morning. The models have been consistent in keeping the bulk of any
precipitation with this wave confined to northern Kansas where the
better mid level moisture will be. Will keep the chance pops along
I-70 intact early Friday morning but have trimmed back pops a little
bit on the southern edge in southwest Kansas.
Later in the period, another shortwave will move out over the
central High Plains around Sunday night with a Pacific cold front
pushing across western Kansas during the afternoon or evening hours.
A few showers and thunderstorms could develop toward central Kansas
depending on whether enough return flow moisture can make it back
into Kansas. A potentially better chance for thunderstorms could
occur across western Kansas as the GFS and ECMWF are showing better
low level moisture return into the central High Plains ahead of this
system.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 1134 AM CDT WED MAR 26 2014
Strong south winds of 28 to 32 knots sustained will prevail through
the early evening hours. GCK, DDC, HYS should remain in VFR flight
category through the day as the stratus and associated MVFR ceilings
will likely remain just east of a HYS-DDC line. Some of this low
level moisture will pull back west perhaps affecting DDC and HYS
this evening, so the flight category forecast for DDC and HYS will
be difficult this evening. There is enough confidence to forecast at
least six or so hours of IFR ceiling at HYS, but DDC and especially
GCK are likely to stay out of the low ceiling.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 43 62 34 59 / 10 10 20 20
GCK 41 62 35 61 / 20 10 20 20
EHA 43 67 37 61 / 20 10 10 0
LBL 43 67 36 62 / 20 10 10 10
HYS 42 58 33 57 / 20 30 20 20
P28 46 67 35 61 / 20 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until Midnight CDT tonight FOR KSZ030-031-044>046-
063>066-076>081-086>090.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Gerard
AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS PADUCAH KY
832 PM CDT Thu Mar 27 2014
.MESOSCALE DISCUSSION...
Issued at 831 PM CDT THU MAR 27 2014
Warm Sector (warm advection) showers and thunderstorms should
continue to push northeast amazing quickly (around 67 knots or 77
mph) this evening...as the 13km RAP showing 50 to 65 knots in a
layer from about 1700 feet up to near 10kft. Although the same
layer is expected to be nearly saturated through at least 2 am CDT
and nearly moist adiabatic...cannot rule out some momentum
transfer of winds to the surface with showers and thunderstorms
with better updrafts. There is still some excellent 0-3km helicity
(around 600 m2/s2) available this evening to support these stronger
updrafts with 0-1 KM CAPE gradient increasing from less than 100
J/KG upward to nearly 500 J/KG along the northeast-southwest
oriented convective line moving through Central MO at this time.
The 13km RAP and 3km HRRR do not reduce the instability
significantly until 09-10z (4-5 am) this morning as it moves
across the Ohio River.
At this time, local concern is for locally damaging wind gusts
overnight versus any larger hail, except with the convective line
in Missouri. The HRRR suggests that stronger wind gusts in excess
of 40 mph may be likely along and north of a Perryville
MO...Marion IL...Owensboro KY line between 1030 pm to 3 am CDT
time frame. Will issue SPS to highlight stronger wind gusts with
isolated convection ahead of line. Will also modify HWO to reflect
better wind potential in the near term.
&&
.SHORT TERM...(Tonight through Saturday night)
Issued at 255 PM CDT THU MAR 27 2014
Models are in general agreement with the timing, movement and
strength of weather features through the first half of the
weekend. Round of warm air advection showers and sct thunderstorms
will continue in a belt right up the Ohio River Valley as we head
into the early evening hours. May see small grauple/small hail in
a few of the stronger cells, but the main instability axis will
remain west of this area, out over MO. Convection later this
evening and overnight associated with approaching sfc front and
mid lvl s/wv will be more widespread across the entire forecast
area. Still may be a small window before midnight over se MO for
some strong storms, but instability really wanes during the night
along the sfc front. Main risk would be with damaging wind gusts
in any bowing segments.
Friday, lingering early morning PoPs over the se 1/4 of the area
will give way to increasing chance PoPs over the far southwest in
the late afternoon. This will be in response to yet another s/wv
moving from the central Plains Friday night to the Ohio Valley
region by midday Saturday. Surface low pressure will move along
the aforementioned frontal boundary that stalls just south of the
area. Sharp h7 wave and decent forcing will result in another
round of decent rains across the area Friday night, with elevated
thunder possible mainly across the srn 1/2 of the forecast area.
Chances will end quickly from west to east Saturday morning, with
dry weather returning Saturday afternoon and night.
Temps were a blend of MOS and bias corrected blended data.
.LONG TERM...(Sunday through Thursday)
Issued at 255 PM CDT THU MAR 27 2014
A ridge of high pressure will keep the PAH forecast area dry and
pleasant Sunday into Sunday night. Abundant sunshine and southerly
winds will help temperatures reach near normal readings in the lower
to middle 60s, with lows Sunday night a little above normal in the
lower to middle 40s.
South winds will increase on Monday ahead of a cold front, helping
temperatures reach the upper 60s to around 70 degrees. ECMWF takes
the front through dry Monday night, while GFS and GEM show some very
light QPF mainly in our western counties Monday afternoon and/or
evening. There is very little moisture to work with, and just went
with some slight chance pops for showers for our west/northwest
counties on Monday, and kept Monday night dry. Behind the front,
temperatures will only fall back to near seasonal readings
By 12z Wednesday, models are in good agreement showing a surface low
over Oklahoma. GEM is most aggressive with precip with this system,
spreading QPF across much of the PAH fa by 12z Wednesday. GFS and
ECMWF only bring some light QPF into our far western counties by the
same time. The good agreement between the GFS/ECMWF leads us to
just include some low pops for our western third of counties Tuesday
night. Precipitation chances will then increase significantly from
west to east Wednesday into Wednesday night, and went with likely
pops for Wednesday night. GFS/ECMWF take the low slowly across the
PAH fa Wednesday night into Thursday, and this will keep decent
chances of precip across our region through the end of the forecast
period. Both models show some pretty healthy CAPE values and LIs
from -1 to -4 across our region from late Tuesday night through
Thursday morning, so went with showers and thunderstorms through
the period.
&&
.AVIATION...
Issued at 637 PM CDT THU MAR 27 2014
Since the original forecast package issuance, current convective
activity is moving about two hours ahead of model timing. Adjusted
timing of MVFR ceilings and visibilities at all WFO PAH TAF sites
earlier (some before midnight) to account for this change.
Otherwise, a return to VFR ceiling and visibility should return
from west to east between 13z-16z on Friday.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
MESOSCALE...Smith
SHORT TERM...MEFFERT
LONG TERM...RST
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS GAYLORD MI
155 PM EDT WED MAR 26 2014
.SYNOPSIS...
ISSUED AT 343 AM EDT WED MAR 26 2014
HIGH PRESSURE TODAY WILL GIVE WAY TO AN APPROACHING STORM SYSTEM
TONIGHT...WHICH WILL PASS THROUGH THE REGION BY FRIDAY MORNING. THIS
SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION ACROSS NORTHERN
MICHIGAN...WITH PRIMARILY SNOW EXPECTED ACROSS EASTERN UPPER
MICHIGAN...AND A RAIN AND SNOW MIXTURE FURTHER SOUTH. HIGH PRESSURE
AND DRY WEATHER RETURNS OVER THE WEEKEND...WITH TEMPERATURES
RETURNING TO MORE SEASONAL LEVELS BY SUNDAY AND MONDAY.
&&
.UPDATE...
ISSUED AT 144 PM EDT WED MAR 26 2014
CU FIELDS HAVE BEEN POPPING UP OVER THE FORECAST AREA, BUT IT IS
STILL A PARTLY SUNNY DAY, BEFORE THE STORM. SO NO CHANGES IN THE
NEAR-TERM (NOW-00Z), EXPECTED.
UPDATE ISSUED AT 959 AM EDT WED MAR 26 2014
TEMPERATURES ARE ROARING BACK TODAY AFTER THE COLD START. SO FAR,
EVERYTHING IS ON TRACK. NO CHANGES EXPECTED AT THIS POINT.
UPDATE ISSUED AT 640 AM EDT WED MAR 26 2014
SCATTERED CU ROAMING MAINLY THE NW LOWER LOWER COAST...BUT NO
REPORTS OF FLURRIES. TEMPS HAVE PLUMMETED INTO PRIMARILY THE
SINGLE DIGITS BELOW ZERO...WITH THE COLDER LOW LYING AREAS DOWN
INTO THE TEENS BELOW ZERO. NO MAJOR UPDATES NEEDED THROUGH TONIGHT
AS THE LATEST DATA SEEMINGLY STILL IN LINE WITH THE FORECAST.
ECMWF STILL THE OUTLIER WITH THE COLDER...MORE SNOWIER SUGGESTION.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 343 AM EDT WED MAR 26 2014
...MODERATING TEMPERATURES WITH NEW STORM AND NEW SNOW DEVELOPING
TONIGHT AND POSSIBLY SOME FREEZING DRIZZLE...
IMPACTS: SLICK AND SNOW COVERED ROADS BY DAYBREAK...ESPECIALLY
EASTERN UPPER WHERE BETTER ACCUMULATIONS ARE ANTICIPATED.
CONFIDENCE: DECENT ON LOCATION OF SNOW AND BETTER ACCUMULATIONS.
LESS CONFIDENCE ON EXTENT OF SNOW/PRECIPITATION ALONG
M-55...ESPECIALLY OVER NEARER THE SAGINAW BAY. CONFIDENCE NOT TOO
HIGH ON FREEZING DRIZZLE EITHER...BUT IMPACT OF THAT LOOKS MINIMAL.
CURRENT WEATHER AND SYNOPTIC PATTERN/EVOLUTION:
UPPER LEVEL TROUGHING IS EXITING EAST OVERNIGHT...WITH RISING MID
LEVEL HEIGHTS THAT WILL CONTINUE RISING THROUGH THE DAY. LIGHTER
WINDS WITH SFC HIGH PRESSURE TO GET REPLACED BY INCREASING
WAA...ESPECIALLY TONIGHT...AHEAD OF DEEPENING SFC LOW PRESSURE INTO
THE CENTRAL PLAINS OVERNIGHT. A WARM FRONT WILL GET BLASTED
NORTHWARD INTO THE WESTERN/SOUTHERN GREAT LAKES...AIDED ALONG BY
STRENGTHENING SW LOW LEVEL WINDS OF 50+ KTS FEEDING INCREASING GULF
OF MEXICO MOISTURE INTO THE GREAT LAKES. TWO DISTINCT SHORTWAVES ARE
SEEN FOR TONIGHT...ONE LIFTING THROUGH THE OHIO RIVER VALLEY...AND
ANOTHER MORE DEFINED WAVE...ASSOCIATED WITH THE MAIN SFC LOW INTO
THE PLAINS. THERE WILL BE SOME WEAKER SHORTWAVE ENERGY LIFTING IN
ACROSS THE U.S. CANADIAN BORDER...BUT OVERALL DEEP LAYER -DIVQ NOT
OUT OF THIS WORLD...AS IT WILL BE ALIGNED ALONG AN INVERTED SFC
TROUGH AXIS FROM THE SFC LOW INTO THE FAR WESTERN GREAT LAKES. NRN
MICHIGAN FORCING WILL BE DRIVEN MOSTLY BY WAA.
WEATHER EXPECTATIONS:
LINGERING PATCHY LAKE DRIVEN CLOUDS WILL BE AROUND THE NW LOWER
COASTLINE THIS MORNING...WITH A CHANGEOVER TO SCATTERED DIURNALLY
DRIVEN CUMULUS THIS MORNING/EARLY AFTERNOON. HIGH LEVEL CIRRUS
CLOUDS WILL ALSO START THICKENING UP LATER TODAY. TEMPERATURES WILL
REACH THE LOWER 20S IN EASTERN UPPER...TO NEAR 30F IN AND AROUND THE
GTV BAY. CLOUDS THICKEN THROUGH THE EVENING...WITH SOME LIGHT SNOWS
LIKELY BREAKING OUT ACROSS EASTERN UPPER AND NW LOWER LATE IN THE
EVENING. THESE SNOWS WILL PICK UP IN INTENSITY THROUGH THE OVERNIGHT
HOURS. THINGS ARE LESS CLEAR ACROSS THE SE CWA...ESPECIALLY CLOSER
TO SAG BAY...BUT LIKELY LIGHT SNOWS FOR AT LEAST A PERIOD OF TIME.
ALTHOUGH NOT A CLASSIC PATTERN...MAYBE SOME FREEZING DRIZZLE AND
LIGHT SNOW TOWARD DAYBREAK ACROSS A GOOD CHUNK OF NRN LOWER.
SNOW AMOUNTS...STILL LOOK PRETTY GOOD BASED ON LATEST DATA. GENERAL
1-3 INCHES...MAX IN HIGHER TERRAIN OF INTERIOR NRN LOWER INTO THE
STRAITS AND PARTS OF EASTERN UPPER. LESS THAN AN INCH NEARER THE SAG
BAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM EDT WED MAR 26 2014
...ACTIVE PERIOD OF WEATHER FORTHCOMING...
HIGH IMPACT WEATHER POTENTIAL: SIGNIFICANT MIXED PRECIPITATION EVENT
THURSDAY THROUGH EARLY FRIDAY. SEVERAL INCHES OF WET SNOW
ACCUMULATION REMAINS POSSIBLE...ESPECIALLY FOR EASTERN UPPER.
OVERVIEW: CHANGE TO A MORE ACTIVE...ALBEIT MILDER...PATTERN STARTING
TO KICK INTO OVERDRIVE...WITH NOAM WATER VAPOR IMAGERY CONFIRMING
HIGH RES RUC GUIDANCE OF DEEPENING FAR WEST ATLANTIC STORM...ALL THE
WHILE WESTERN RIDGING HAS ESSENTIALLY SUCCUMBED TO STRONG PACIFIC
ENERGY PUSHING INTO THE PACIFIC NORTHWEST. THE FORMER WILL
ESSENTIALLY ACT AS A SLING-SHOT...PROPELLING OVERHEAD TROUGHING/COLD
POOL TO THE NORTHEAST AS IT UNDERGOES EXPLOSIVE DEEPENING ON ITS WAY
TO THE CANADIAN MARITIMES. UNFORTUNATELY...WHILE THE LATTER LOOKS TO
BRING IN SOME "MILDER" AIR AS IT PUSHES EAST ACROSS THE CONUS...IT
ALSO LOOKS TO DRUM UP SOME SIGNIFICANT LATE WINTER TYPE WEATHER
ACROSS OUR AREA TO END THIS WORK WEEK. OPEN FOR BUSINESS PACIFIC
MEANS ACTIVE WEATHER COULD CONTINUE FOR THE FORECASTABLE FUTURE...
AND WITH COLD AIR LURKING JUST TO OUR NORTH...SETS UP POTENTIAL FOR
ADDITIONAL MESSY MIXED PRECIP EVENTS HEADING INTO NEXT WEEK. WE
SHALL SEE.
PRIMARY FORECAST CONCERNS/CHALLENGES: PLENTY...WITH EMPHASIS NO
DOUBT CENTERED ON PRECIPITATION TYPE/AMOUNTS/AND TIMING OF EXPECTED
LATE SEASON WINTER STORM THURSDAY THROUGH EARLY FRIDAY. HEADLINE
POTENTIAL WILL ALSO NEED TO BE ADDRESSED.
DETAILS: UNFORTUNATELY...STILL ONE VERY CHALLENGING...AND HENCE
RATHER LOW CONFIDENCE FORECAST HEADING THROUGH THURSDAY AND THURSDAY
EVENING. PROBLEMS ARE REALLY TWO-FOLD...CENTERING ON EXACT THERMAL
PROPERTIES AND EVIDENCE DEEP MOISTURE MAY DEPART FOR A TIME THURSDAY
MORNING...LEAVING OPEN AN OPPORTUNITY FOR SOME FREEZING DRIZZLE.
SYSTEM DRIVING ALL THIS UNCERTAINTY IS CURRENT WEST COAST WAVE
EXPECTED TO RACE EAST ACROSS THE REGION...DEPARTING OFF TO OUR EAST
QUICKLY ON FRIDAY. TACKLING THE FIRST CONCERN (THERMAL FIELDS): MID
LEVEL WAVE ITSELF CONTINUES TO LOOK DISJOINTED ON ITS PASSAGE...
WHICH PROBABLY ACCOUNTS FOR CONTINUED RATHER WIDE RANGE IN EXACT
SURFACE LOW TRACK AND ATTENDANT LOW LEVEL THERMAL PROGS. 12Z ECWMF
EASILY FURTHEST SOUTH...KEEPING MAIN SURFACE WAVE TIED TO SOUTHERN
PORTION OF VORT LOBE...PASSING IT ACROSS SOUTHEAST LOWER MICHIGAN
EARLY FRIDAY MORNING. THIS SOLUTION WOULD SUGGEST MAINLY AN ALL SNOW
SCENARIO FOR AREAS ALONG AND NORTH OF M-32...WITH A RAIN/SNOW
MIXTURE FURTHER SOUTH (TRANSITION TO JUST RAIN DOWN NEAR SAGINAW
BAY). WHILE FURTHER NORTH...ALL OTHER AVAILABLE GUIDANCE OFFERING
VARIOUS THERMAL SOLUTIONS...WITH EVEN SOME OF THE NORTHERN MEMBERS
SHOWING EASTERN UPPER AND FAR NORTHERN LOWER MICHIGAN REMAINING ALL
SNOW. AS FOR THE SECOND CONCERN (FREEZING DRIZZLE POTENTIAL THURSDAY
MORNING): COULD EASILY ENVISION A LOSS OF DEEP SATURATION FOR A TIME
THURSDAY MORNING/EARLY THURSDAY AFTERNOON FOR NORTHERN LOWER AS
INITIAL WING OF STRONG WAA/CONVERGENCE PASSES BY TO OUR
NORTH...WAITING ON APPROACH OF MID LEVEL SUPPORT LATER IN THE DAY TO
DRIVE REEMERGENCE OF DEEPER MOISTURE. MODEL DERIVED SOUNDINGS
PARTIALLY CONCUR...WITH MOISTURE SHALLOWING OUT JUST ABOVE -10C.
THIS WOULD POTENTIALLY SET UP A FREEZING DRIZZLE SCENARIO BEFORE
SURFACE TEMPERATURES WARM...WHICH MAY BE A HIGH IMPACT TRAVEL EVENT
IF/WHERE WEDNESDAY NIGHTS SNOWS DO NOT MATERIALIZE. KINDA POINTLESS
TO INCLUDE THIS TYPE OF SPECIFICS JUST YET WHEN DEALING WITH
CONTINUED GUIDANCE CHAOS...BUT DEFINITELY SOMETHING TO KEEP AN EYE
ON. DESPITE WHAT HAPPENS THURSDAY AND THURSDAY EVENING...SURFACE LOW
BACKSIDE CAA AND ARRIVAL OF DEEPER MOISTURE SHOULD CHANGE ANY MIXED
PRECIP BACK TO SNOW FROM NORTHWEST TO SOUTHEAST THURSDAY
NIGHT...WITH A RAIN OR A MIXTURE HANGING ON LONGEST ACROSS THE FAR
SOUTHEAST. ANY LINGERING PRECIPITATION SHOULD END RATHER QUICKLY ON
FRIDAY.
SNOW AMOUNTS AND POSSIBLE HEADLINES: AS MENTIONED...JUST NOT OVERLY
IMPRESSED WITH DYNAMICS WITH THIS SYSTEM. MID LEVEL WAVE/SURFACE
REFLECTION BOTH APPEAR TO WEAKEN ON THEIR PASSAGE. SYSTEM DOES HAVE
A RATHER HEALTHY MOISTURE TAP WITH IT...WITH CONNECTION TO THE
WESTERN GULF OF MEXICO HELPING SPIKE PWAT VALUES TO NEAR THREE
QUARTERS OF AN INCH BY LATER THURSDAY. SHOULD BE A DECENT PRECIP
MAKER (NOTHING TOO HEAVY GIVING WEAKENING SUPPORT)...AND AS
MENTIONED YESTERDAY...WOULDN/T BE SURPRISED TO SEE SOME AREAS EXCEED
HALF INCH LIQUID EQUIVALENT AMOUNTS BY THE TIME EVERYTHING WRAPS UP
FRIDAY. OF COURSE...SNOW AMOUNTS ALL TIED TO THERMAL FIELDS...WITH
THE GREATEST SUPPORT FOR SIGNIFICANT SNOW ACCUMULATIONS ACROSS
EASTERN UPPER MICHIGAN. MUCH TOUGHER CALL ACROSS NORTHERN LOWER
MICHIGAN. GIVEN ARRAY OF UNCERTAINTIES...SIMPLY CANNOT JUSTIFY
MAKING SIGNIFICANT CHANGES TO INHERITED FORECAST...WHICH KEEPS THE
MAIN SNOW ACCUMULATIONS...ON THE ORDER OF 3 TO 5 INCHES...ACROSS
EASTERN UPPER MICHIGAN...WITH AMOUNTS ACROSS NORTHERN LOWER RANGING
FROM AN INCH OR TWO NEAR THE TIP OF THE MITT...TO JUST A DUSTING
SOUTH OF M-68. WHILE NOT FORTHCOMING ON THIS SHIFT...COULD
EVENTUALLY SEE THE NEED FOR AN ADVISORY FOR AREAS NORTH OF THE
BRIDGE.
REST OF THE FORECAST: WITH PRIMARY FOCUS ON EARLY PERIOD
SYSTEM...TOOK MORE OF A GENERIC GUIDANCE BLEND APPROACH FOR THE
WEEKEND INTO THE START OF NEXT WORK WEEK. CANADIAN HIGH PRESSURE
BUILDS INTO THE NORTHERN LAKES LATER FRIDAY THROUGH SATURDAY...WITH
ATTENDANT QUICK SHOT OF CAA. FORTUNATELY...THIS AIRMASS LOOKS TO BE
NOWHERE NEAR AS COLD AS ITS PREDECESSORS...AND HIGHS SATURDAY SHOULD
BE ABLE TO REACH WELL INTO THE 30S. THIS HIGH SHOULD KEEP NEXT WAVE
AND AXIS OF PRECIPITATION OFF TO OUR SOUTH TO START THE WEEKEND.
PLENTY OF QUESTIONS/UNCERTAINTY THERE-ON-AFTER...WITH SOME HINTS
SLOW SOUTHWARD MOVING BAROCLINIC AXIS WILL INTERACT WITH ADDITIONAL
ENERGY MOVING OUT OF THE ROCKIES...THE TWO WORKING IN TANDEM TO
DRIVE ANOTHER ROUND OF MIXED PRECIPITATION INTO OUR AREA TO START
NEXT WORK WEEK. DEPENDING ON JUST HOW FAR SOUTH AND QUICK THIS FRONT
MOVES INTO THE NORTHERN LAKES (IF IT DOES AT ALL) WILL DICTATE JUST
HOW "WARM" CONDITIONS BECOME SUNDAY AND MONDAY. CURRENT SUPPORT FOR
WIDESPREAD HIGHS REACHING INTO THE 40S BOTH DAYS OVER NORTHER LOWER
MICHIGAN...JUST A TOUCH COOLER NORTH OF THE STRAITS. LETS GET
THROUGH THIS FIRST SYSTEM...WITH PLENTY OF TIME TO REVISIT THESE
LATER PERIODS IN COMING DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 150 PM EDT WED MAR 26 2014
SLOWED THE TIMING DOWN ON THE PRECIPITATION FOR THE NIGHT ON THE
EAST SIDE OF THE STATE AS THE MODELS ARE BEGINNING TO AGREE ON THE
TRACK. THE MAIN IMPACT OVERNIGHT WILL BE THE LOWERING OF THE CIGS
AS THE WARM FRONT APPROACHES. THEN BY 12Z WITH THE WARM FRONT ON
OUR DOORSTEP, THE VSBYS WILL BEGIN TO FALL AS SNOW MOVES IN, AND
LOW LEVEL WIND SHEAR. WILL BE EXPECTING AS MIX NEAR TVC AND MBL
AROUND 12Z, AND THEN ALL RAIN BY 15Z AS THE WARM AIR FLOODS INTO
THE REGION. FOR NOW, IT LOOKS LIKE A MIX THROUGH 18Z AT APN AND
PLN AS THE WARM FRONT IS SLOW TO MOVE THROUGH THE NE LOWER, AND IS
HUNG UP AT THE STRAITS. SFC TEMPERATURES AT THIS POINT LOOK TO BE
ABOVE FREEZING IN THE MORNING, SO WON`T EXPECT ANY FREEZING RAIN,
EXCEPT FOR WHAT RAIN FALLS ON UNTREATED PAVEMENT, SO THAT
SCATTERED ICE PATCHES WILL FORM.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...MSB
SHORT TERM...SMD
LONG TERM...MSB
AVIATION...JSL
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1001 AM EDT WED MAR 26 2014
.SYNOPSIS...
ISSUED AT 343 AM EDT WED MAR 26 2014
HIGH PRESSURE TODAY WILL GIVE WAY TO AN APPROACHING STORM SYSTEM
TONIGHT...WHICH WILL PASS THROUGH THE REGION BY FRIDAY MORNING. THIS
SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION ACROSS NORTHERN
MICHIGAN...WITH PRIMARILY SNOW EXPECTED ACROSS EASTERN UPPER
MICHIGAN...AND A RAIN AND SNOW MIXTURE FURTHER SOUTH. HIGH PRESSURE
AND DRY WEATHER RETURNS OVER THE WEEKEND...WITH TEMPERATURES
RETURNING TO MORE SEASONAL LEVELS BY SUNDAY AND MONDAY.
&&
.UPDATE...
ISSUED AT 959 AM EDT WED MAR 26 2014
TEMPERATURES ARE ROARING BACK TODAY AFTER THE COLD START. SO FAR,
EVERYTHING IS ON TRACK. NO CHANGES EXPECTED AT THIS POINT.
UPDATE ISSUED AT 640 AM EDT WED MAR 26 2014
SCATTERED CU ROAMING MAINLY THE NW LOWER LOWER COAST...BUT NO
REPORTS OF FLURRIES. TEMPS HAVE PLUMMETED INTO PRIMARILY THE
SINGLE DIGITS BELOW ZERO...WITH THE COLDER LOW LYING AREAS DOWN
INTO THE TEENS BELOW ZERO. NO MAJOR UPDATES NEEDED THROUGH TONIGHT
AS THE LATEST DATA SEEMINGLY STILL IN LINE WITH THE FORECAST.
ECMWF STILL THE OUTLIER WITH THE COLDER...MORE SNOWIER SUGGESTION.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 343 AM EDT WED MAR 26 2014
...MODERATING TEMPERATURES WITH NEW STORM AND NEW SNOW DEVELOPING
TONIGHT AND POSSIBLY SOME FREEZING DRIZZLE...
IMPACTS: SLICK AND SNOW COVERED ROADS BY DAYBREAK...ESPECIALLY
EASTERN UPPER WHERE BETTER ACCUMULATIONS ARE ANTICIPATED.
CONFIDENCE: DECENT ON LOCATION OF SNOW AND BETTER ACCUMULATIONS.
LESS CONFIDENCE ON EXTENT OF SNOW/PRECIPITATION ALONG
M-55...ESPECIALLY OVER NEARER THE SAGINAW BAY. CONFIDENCE NOT TOO
HIGH ON FREEZING DRIZZLE EITHER...BUT IMPACT OF THAT LOOKS MINIMAL.
CURRENT WEATHER AND SYNOPTIC PATTERN/EVOLUTION:
UPPER LEVEL TROUGHING IS EXITING EAST OVERNIGHT...WITH RISING MID
LEVEL HEIGHTS THAT WILL CONTINUE RISING THROUGH THE DAY. LIGHTER
WINDS WITH SFC HIGH PRESSURE TO GET REPLACED BY INCREASING
WAA...ESPECIALLY TONIGHT...AHEAD OF DEEPENING SFC LOW PRESSURE INTO
THE CENTRAL PLAINS OVERNIGHT. A WARM FRONT WILL GET BLASTED
NORTHWARD INTO THE WESTERN/SOUTHERN GREAT LAKES...AIDED ALONG BY
STRENGTHENING SW LOW LEVEL WINDS OF 50+ KTS FEEDING INCREASING GULF
OF MEXICO MOISTURE INTO THE GREAT LAKES. TWO DISTINCT SHORTWAVES ARE
SEEN FOR TONIGHT...ONE LIFTING THROUGH THE OHIO RIVER VALLEY...AND
ANOTHER MORE DEFINED WAVE...ASSOCIATED WITH THE MAIN SFC LOW INTO
THE PLAINS. THERE WILL BE SOME WEAKER SHORTWAVE ENERGY LIFTING IN
ACROSS THE U.S. CANADIAN BORDER...BUT OVERALL DEEP LAYER -DIVQ NOT
OUT OF THIS WORLD...AS IT WILL BE ALIGNED ALONG AN INVERTED SFC
TROUGH AXIS FROM THE SFC LOW INTO THE FAR WESTERN GREAT LAKES. NRN
MICHIGAN FORCING WILL BE DRIVEN MOSTLY BY WAA.
WEATHER EXPECTATIONS:
LINGERING PATCHY LAKE DRIVEN CLOUDS WILL BE AROUND THE NW LOWER
COASTLINE THIS MORNING...WITH A CHANGEOVER TO SCATTERED DIURNALLY
DRIVEN CUMULUS THIS MORNING/EARLY AFTERNOON. HIGH LEVEL CIRRUS
CLOUDS WILL ALSO START THICKENING UP LATER TODAY. TEMPERATURES WILL
REACH THE LOWER 20S IN EASTERN UPPER...TO NEAR 30F IN AND AROUND THE
GTV BAY. CLOUDS THICKEN THROUGH THE EVENING...WITH SOME LIGHT SNOWS
LIKELY BREAKING OUT ACROSS EASTERN UPPER AND NW LOWER LATE IN THE
EVENING. THESE SNOWS WILL PICK UP IN INTENSITY THROUGH THE OVERNIGHT
HOURS. THINGS ARE LESS CLEAR ACROSS THE SE CWA...ESPECIALLY CLOSER
TO SAG BAY...BUT LIKELY LIGHT SNOWS FOR AT LEAST A PERIOD OF TIME.
ALTHOUGH NOT A CLASSIC PATTERN...MAYBE SOME FREEZING DRIZZLE AND
LIGHT SNOW TOWARD DAYBREAK ACROSS A GOOD CHUNK OF NRN LOWER.
SNOW AMOUNTS...STILL LOOK PRETTY GOOD BASED ON LATEST DATA. GENERAL
1-3 INCHES...MAX IN HIGHER TERRAIN OF INTERIOR NRN LOWER INTO THE
STRAITS AND PARTS OF EASTERN UPPER. LESS THAN AN INCH NEARER THE SAG
BAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM EDT WED MAR 26 2014
...ACTIVE PERIOD OF WEATHER FORTHCOMING...
HIGH IMPACT WEATHER POTENTIAL: SIGNIFICANT MIXED PRECIPITATION EVENT
THURSDAY THROUGH EARLY FRIDAY. SEVERAL INCHES OF WET SNOW
ACCUMULATION REMAINS POSSIBLE...ESPECIALLY FOR EASTERN UPPER.
OVERVIEW: CHANGE TO A MORE ACTIVE...ALBEIT MILDER...PATTERN STARTING
TO KICK INTO OVERDRIVE...WITH NOAM WATER VAPOR IMAGERY CONFIRMING
HIGH RES RUC GUIDANCE OF DEEPENING FAR WEST ATLANTIC STORM...ALL THE
WHILE WESTERN RIDGING HAS ESSENTIALLY SUCCUMBED TO STRONG PACIFIC
ENERGY PUSHING INTO THE PACIFIC NORTHWEST. THE FORMER WILL
ESSENTIALLY ACT AS A SLING-SHOT...PROPELLING OVERHEAD TROUGHING/COLD
POOL TO THE NORTHEAST AS IT UNDERGOES EXPLOSIVE DEEPENING ON ITS WAY
TO THE CANADIAN MARITIMES. UNFORTUNATELY...WHILE THE LATTER LOOKS TO
BRING IN SOME "MILDER" AIR AS IT PUSHES EAST ACROSS THE CONUS...IT
ALSO LOOKS TO DRUM UP SOME SIGNIFICANT LATE WINTER TYPE WEATHER
ACROSS OUR AREA TO END THIS WORK WEEK. OPEN FOR BUSINESS PACIFIC
MEANS ACTIVE WEATHER COULD CONTINUE FOR THE FORECASTABLE FUTURE...
AND WITH COLD AIR LURKING JUST TO OUR NORTH...SETS UP POTENTIAL FOR
ADDITIONAL MESSY MIXED PRECIP EVENTS HEADING INTO NEXT WEEK. WE
SHALL SEE.
PRIMARY FORECAST CONCERNS/CHALLENGES: PLENTY...WITH EMPHASIS NO
DOUBT CENTERED ON PRECIPITATION TYPE/AMOUNTS/AND TIMING OF EXPECTED
LATE SEASON WINTER STORM THURSDAY THROUGH EARLY FRIDAY. HEADLINE
POTENTIAL WILL ALSO NEED TO BE ADDRESSED.
DETAILS: UNFORTUNATELY...STILL ONE VERY CHALLENGING...AND HENCE
RATHER LOW CONFIDENCE FORECAST HEADING THROUGH THURSDAY AND THURSDAY
EVENING. PROBLEMS ARE REALLY TWO-FOLD...CENTERING ON EXACT THERMAL
PROPERTIES AND EVIDENCE DEEP MOISTURE MAY DEPART FOR A TIME THURSDAY
MORNING...LEAVING OPEN AN OPPORTUNITY FOR SOME FREEZING DRIZZLE.
SYSTEM DRIVING ALL THIS UNCERTAINTY IS CURRENT WEST COAST WAVE
EXPECTED TO RACE EAST ACROSS THE REGION...DEPARTING OFF TO OUR EAST
QUICKLY ON FRIDAY. TACKLING THE FIRST CONCERN (THERMAL FIELDS): MID
LEVEL WAVE ITSELF CONTINUES TO LOOK DISJOINTED ON ITS PASSAGE...
WHICH PROBABLY ACCOUNTS FOR CONTINUED RATHER WIDE RANGE IN EXACT
SURFACE LOW TRACK AND ATTENDANT LOW LEVEL THERMAL PROGS. 12Z ECWMF
EASILY FURTHEST SOUTH...KEEPING MAIN SURFACE WAVE TIED TO SOUTHERN
PORTION OF VORT LOBE...PASSING IT ACROSS SOUTHEAST LOWER MICHIGAN
EARLY FRIDAY MORNING. THIS SOLUTION WOULD SUGGEST MAINLY AN ALL SNOW
SCENARIO FOR AREAS ALONG AND NORTH OF M-32...WITH A RAIN/SNOW
MIXTURE FURTHER SOUTH (TRANSITION TO JUST RAIN DOWN NEAR SAGINAW
BAY). WHILE FURTHER NORTH...ALL OTHER AVAILABLE GUIDANCE OFFERING
VARIOUS THERMAL SOLUTIONS...WITH EVEN SOME OF THE NORTHERN MEMBERS
SHOWING EASTERN UPPER AND FAR NORTHERN LOWER MICHIGAN REMAINING ALL
SNOW. AS FOR THE SECOND CONCERN (FREEZING DRIZZLE POTENTIAL THURSDAY
MORNING): COULD EASILY ENVISION A LOSS OF DEEP SATURATION FOR A TIME
THURSDAY MORNING/EARLY THURSDAY AFTERNOON FOR NORTHERN LOWER AS
INITIAL WING OF STRONG WAA/CONVERGENCE PASSES BY TO OUR
NORTH...WAITING ON APPROACH OF MID LEVEL SUPPORT LATER IN THE DAY TO
DRIVE REEMERGENCE OF DEEPER MOISTURE. MODEL DERIVED SOUNDINGS
PARTIALLY CONCUR...WITH MOISTURE SHALLOWING OUT JUST ABOVE -10C.
THIS WOULD POTENTIALLY SET UP A FREEZING DRIZZLE SCENARIO BEFORE
SURFACE TEMPERATURES WARM...WHICH MAY BE A HIGH IMPACT TRAVEL EVENT
IF/WHERE WEDNESDAY NIGHTS SNOWS DO NOT MATERIALIZE. KINDA POINTLESS
TO INCLUDE THIS TYPE OF SPECIFICS JUST YET WHEN DEALING WITH
CONTINUED GUIDANCE CHAOS...BUT DEFINITELY SOMETHING TO KEEP AN EYE
ON. DESPITE WHAT HAPPENS THURSDAY AND THURSDAY EVENING...SURFACE LOW
BACKSIDE CAA AND ARRIVAL OF DEEPER MOISTURE SHOULD CHANGE ANY MIXED
PRECIP BACK TO SNOW FROM NORTHWEST TO SOUTHEAST THURSDAY
NIGHT...WITH A RAIN OR A MIXTURE HANGING ON LONGEST ACROSS THE FAR
SOUTHEAST. ANY LINGERING PRECIPITATION SHOULD END RATHER QUICKLY ON
FRIDAY.
SNOW AMOUNTS AND POSSIBLE HEADLINES: AS MENTIONED...JUST NOT OVERLY
IMPRESSED WITH DYNAMICS WITH THIS SYSTEM. MID LEVEL WAVE/SURFACE
REFLECTION BOTH APPEAR TO WEAKEN ON THEIR PASSAGE. SYSTEM DOES HAVE
A RATHER HEALTHY MOISTURE TAP WITH IT...WITH CONNECTION TO THE
WESTERN GULF OF MEXICO HELPING SPIKE PWAT VALUES TO NEAR THREE
QUARTERS OF AN INCH BY LATER THURSDAY. SHOULD BE A DECENT PRECIP
MAKER (NOTHING TOO HEAVY GIVING WEAKENING SUPPORT)...AND AS
MENTIONED YESTERDAY...WOULDN/T BE SURPRISED TO SEE SOME AREAS EXCEED
HALF INCH LIQUID EQUIVALENT AMOUNTS BY THE TIME EVERYTHING WRAPS UP
FRIDAY. OF COURSE...SNOW AMOUNTS ALL TIED TO THERMAL FIELDS...WITH
THE GREATEST SUPPORT FOR SIGNIFICANT SNOW ACCUMULATIONS ACROSS
EASTERN UPPER MICHIGAN. MUCH TOUGHER CALL ACROSS NORTHERN LOWER
MICHIGAN. GIVEN ARRAY OF UNCERTAINTIES...SIMPLY CANNOT JUSTIFY
MAKING SIGNIFICANT CHANGES TO INHERITED FORECAST...WHICH KEEPS THE
MAIN SNOW ACCUMULATIONS...ON THE ORDER OF 3 TO 5 INCHES...ACROSS
EASTERN UPPER MICHIGAN...WITH AMOUNTS ACROSS NORTHERN LOWER RANGING
FROM AN INCH OR TWO NEAR THE TIP OF THE MITT...TO JUST A DUSTING
SOUTH OF M-68. WHILE NOT FORTHCOMING ON THIS SHIFT...COULD
EVENTUALLY SEE THE NEED FOR AN ADVISORY FOR AREAS NORTH OF THE
BRIDGE.
REST OF THE FORECAST: WITH PRIMARY FOCUS ON EARLY PERIOD
SYSTEM...TOOK MORE OF A GENERIC GUIDANCE BLEND APPROACH FOR THE
WEEKEND INTO THE START OF NEXT WORK WEEK. CANADIAN HIGH PRESSURE
BUILDS INTO THE NORTHERN LAKES LATER FRIDAY THROUGH SATURDAY...WITH
ATTENDANT QUICK SHOT OF CAA. FORTUNATELY...THIS AIRMASS LOOKS TO BE
NOWHERE NEAR AS COLD AS ITS PREDECESSORS...AND HIGHS SATURDAY SHOULD
BE ABLE TO REACH WELL INTO THE 30S. THIS HIGH SHOULD KEEP NEXT WAVE
AND AXIS OF PRECIPITATION OFF TO OUR SOUTH TO START THE WEEKEND.
PLENTY OF QUESTIONS/UNCERTAINTY THERE-ON-AFTER...WITH SOME HINTS
SLOW SOUTHWARD MOVING BAROCLINIC AXIS WILL INTERACT WITH ADDITIONAL
ENERGY MOVING OUT OF THE ROCKIES...THE TWO WORKING IN TANDEM TO
DRIVE ANOTHER ROUND OF MIXED PRECIPITATION INTO OUR AREA TO START
NEXT WORK WEEK. DEPENDING ON JUST HOW FAR SOUTH AND QUICK THIS FRONT
MOVES INTO THE NORTHERN LAKES (IF IT DOES AT ALL) WILL DICTATE JUST
HOW "WARM" CONDITIONS BECOME SUNDAY AND MONDAY. CURRENT SUPPORT FOR
WIDESPREAD HIGHS REACHING INTO THE 40S BOTH DAYS OVER NORTHER LOWER
MICHIGAN...JUST A TOUCH COOLER NORTH OF THE STRAITS. LETS GET
THROUGH THIS FIRST SYSTEM...WITH PLENTY OF TIME TO REVISIT THESE
LATER PERIODS IN COMING DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 640 AM EDT WED MAR 26 2014
MAYBE JUST A VERY BRIEF MVFR CIG/FLURRY ALONG NW LOWER COAST EARLY
THIS MORNING. OTHERWISE...VFR FOR AWHILE...AS THE RETURN OF SKIES
TODAY WILL SEE CU/STRATOCU IN THE 4-5K RANGE...WITH INCREASING
HIGH LEVEL CLOUDS. THESE CLOUDS WILL THICKEN THROUGH TONIGHT DUE
TO AN INCOMING LOW PRESSURE SYSTEM. THIS SYSTEM WILL SPREAD SNOW
NORTH INTO NW LOWER/EASTERN UPPER LATE THIS EVENING...AND ACROSS
APN AFTER MIDNIGHT. CIGS AND VSBYS WILL DROP INTO IFR RANGE
THROUGH THE OVERNIGHT HOURS.
A SW BREEZE DEVELOPS DURING THE DAY WEDNESDAY...BECOMING LIGHTER
SE THAT EVENING. LLWS DEVELOPS AT ALL TAF SITES LATE IN THE
TAF.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...MSB
SHORT TERM...SMD
LONG TERM...MSB
AVIATION...SMD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
650 AM EDT WED MAR 26 2014
.SYNOPSIS...
ISSUED AT 343 AM EDT WED MAR 26 2014
HIGH PRESSURE TODAY WILL GIVE WAY TO AN APPROACHING STORM SYSTEM
TONIGHT...WHICH WILL PASS THROUGH THE REGION BY FRIDAY MORNING. THIS
SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION ACROSS NORTHERN
MICHIGAN...WITH PRIMARILY SNOW EXPECTED ACROSS EASTERN UPPER
MICHIGAN...AND A RAIN AND SNOW MIXTURE FURTHER SOUTH. HIGH PRESSURE
AND DRY WEATHER RETURNS OVER THE WEEKEND...WITH TEMPERATURES
RETURNING TO MORE SEASONAL LEVELS BY SUNDAY AND MONDAY.
&&
.UPDATE...
ISSUED AT 640 AM EDT WED MAR 26 2014
SCATTERED CU ROAMING MAINLY THE NW LOWER LOWER COAST...BUT NO
REPORTS OF FLURRIES. TEMPS HAVE PLUMMETED INTO PRIMARILY THE
SINGLE DIGITS BELOW ZERO...WITH THE COLDER LOW LYING AREAS DOWN
INTO THE TEENS BELOW ZERO. NO MAJOR UPDATES NEEDED THROUGH TONIGHT
AS THE LATEST DATA SEEMINGLY STILL IN LINE WITH THE FORECAST.
ECMWF STILL THE OUTLIER WITH THE COLDER...MORE SNOWIER SUGGESTION.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 343 AM EDT WED MAR 26 2014
...MODERATING TEMPERATURES WITH NEW STORM AND NEW SNOW DEVELOPING
TONIGHT AND POSSIBLY SOME FREEZING DRIZZLE...
IMPACTS: SLICK AND SNOW COVERED ROADS BY DAYBREAK...ESPECIALLY
EASTERN UPPER WHERE BETTER ACCUMULATIONS ARE ANTICIPATED.
CONFIDENCE: DECENT ON LOCATION OF SNOW AND BETTER ACCUMULATIONS.
LESS CONFIDENCE ON EXTENT OF SNOW/PRECIPITATION ALONG
M-55...ESPECIALLY OVER NEARER THE SAGINAW BAY. CONFIDENCE NOT TOO
HIGH ON FREEZING DRIZZLE EITHER...BUT IMPACT OF THAT LOOKS MINIMAL.
CURRENT WEATHER AND SYNOPTIC PATTERN/EVOLUTION:
UPPER LEVEL TROUGHING IS EXITING EAST OVERNIGHT...WITH RISING MID
LEVEL HEIGHTS THAT WILL CONTINUE RISING THROUGH THE DAY. LIGHTER
WINDS WITH SFC HIGH PRESSURE TO GET REPLACED BY INCREASING
WAA...ESPECIALLY TONIGHT...AHEAD OF DEEPENING SFC LOW PRESSURE INTO
THE CENTRAL PLAINS OVERNIGHT. A WARM FRONT WILL GET BLASTED
NORTHWARD INTO THE WESTERN/SOUTHERN GREAT LAKES...AIDED ALONG BY
STRENGTHENING SW LOW LEVEL WINDS OF 50+ KTS FEEDING INCREASING GULF
OF MEXICO MOISTURE INTO THE GREAT LAKES. TWO DISTINCT SHORTWAVES ARE
SEEN FOR TONIGHT...ONE LIFTING THROUGH THE OHIO RIVER VALLEY...AND
ANOTHER MORE DEFINED WAVE...ASSOCIATED WITH THE MAIN SFC LOW INTO
THE PLAINS. THERE WILL BE SOME WEAKER SHORTWAVE ENERGY LIFTING IN
ACROSS THE U.S. CANADIAN BORDER...BUT OVERALL DEEP LAYER -DIVQ NOT
OUT OF THIS WORLD...AS IT WILL BE ALIGNED ALONG AN INVERTED SFC
TROUGH AXIS FROM THE SFC LOW INTO THE FAR WESTERN GREAT LAKES. NRN
MICHIGAN FORCING WILL BE DRIVEN MOSTLY BY WAA.
WEATHER EXPECTATIONS:
LINGERING PATCHY LAKE DRIVEN CLOUDS WILL BE AROUND THE NW LOWER
COASTLINE THIS MORNING...WITH A CHANGEOVER TO SCATTERED DIURNALLY
DRIVEN CUMULUS THIS MORNING/EARLY AFTERNOON. HIGH LEVEL CIRRUS
CLOUDS WILL ALSO START THICKENING UP LATER TODAY. TEMPERATURES WILL
REACH THE LOWER 20S IN EASTERN UPPER...TO NEAR 30F IN AND AROUND THE
GTV BAY. CLOUDS THICKEN THROUGH THE EVENING...WITH SOME LIGHT SNOWS
LIKELY BREAKING OUT ACROSS EASTERN UPPER AND NW LOWER LATE IN THE
EVENING. THESE SNOWS WILL PICK UP IN INTENSITY THROUGH THE OVERNIGHT
HOURS. THINGS ARE LESS CLEAR ACROSS THE SE CWA...ESPECIALLY CLOSER
TO SAG BAY...BUT LIKELY LIGHT SNOWS FOR AT LEAST A PERIOD OF TIME.
ALTHOUGH NOT A CLASSIC PATTERN...MAYBE SOME FREEZING DRIZZLE AND
LIGHT SNOW TOWARD DAYBREAK ACROSS A GOOD CHUNK OF NRN LOWER.
SNOW AMOUNTS...STILL LOOK PRETTY GOOD BASED ON LATEST DATA. GENERAL
1-3 INCHES...MAX IN HIGHER TERRAIN OF INTERIOR NRN LOWER INTO THE
STRAITS AND PARTS OF EASTERN UPPER. LESS THAN AN INCH NEARER THE SAG
BAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM EDT WED MAR 26 2014
...ACTIVE PERIOD OF WEATHER FORTHCOMING...
HIGH IMPACT WEATHER POTENTIAL: SIGNIFICANT MIXED PRECIPITATION EVENT
THURSDAY THROUGH EARLY FRIDAY. SEVERAL INCHES OF WET SNOW
ACCUMULATION REMAINS POSSIBLE...ESPECIALLY FOR EASTERN UPPER.
OVERVIEW: CHANGE TO A MORE ACTIVE...ALBEIT MILDER...PATTERN STARTING
TO KICK INTO OVERDRIVE...WITH NOAM WATER VAPOR IMAGERY CONFIRMING
HIGH RES RUC GUIDANCE OF DEEPENING FAR WEST ATLANTIC STORM...ALL THE
WHILE WESTERN RIDGING HAS ESSENTIALLY SUCCUMBED TO STRONG PACIFIC
ENERGY PUSHING INTO THE PACIFIC NORTHWEST. THE FORMER WILL
ESSENTIALLY ACT AS A SLING-SHOT...PROPELLING OVERHEAD TROUGHING/COLD
POOL TO THE NORTHEAST AS IT UNDERGOES EXPLOSIVE DEEPENING ON ITS WAY
TO THE CANADIAN MARITIMES. UNFORTUNATELY...WHILE THE LATTER LOOKS TO
BRING IN SOME "MILDER" AIR AS IT PUSHES EAST ACROSS THE CONUS...IT
ALSO LOOKS TO DRUM UP SOME SIGNIFICANT LATE WINTER TYPE WEATHER
ACROSS OUR AREA TO END THIS WORK WEEK. OPEN FOR BUSINESS PACIFIC
MEANS ACTIVE WEATHER COULD CONTINUE FOR THE FORECASTABLE FUTURE...
AND WITH COLD AIR LURKING JUST TO OUR NORTH...SETS UP POTENTIAL FOR
ADDITIONAL MESSY MIXED PRECIP EVENTS HEADING INTO NEXT WEEK. WE
SHALL SEE.
PRIMARY FORECAST CONCERNS/CHALLENGES: PLENTY...WITH EMPHASIS NO
DOUBT CENTERED ON PRECIPITATION TYPE/AMOUNTS/AND TIMING OF EXPECTED
LATE SEASON WINTER STORM THURSDAY THROUGH EARLY FRIDAY. HEADLINE
POTENTIAL WILL ALSO NEED TO BE ADDRESSED.
DETAILS: UNFORTUNATELY...STILL ONE VERY CHALLENGING...AND HENCE
RATHER LOW CONFIDENCE FORECAST HEADING THROUGH THURSDAY AND THURSDAY
EVENING. PROBLEMS ARE REALLY TWO-FOLD...CENTERING ON EXACT THERMAL
PROPERTIES AND EVIDENCE DEEP MOISTURE MAY DEPART FOR A TIME THURSDAY
MORNING...LEAVING OPEN AN OPPORTUNITY FOR SOME FREEZING DRIZZLE.
SYSTEM DRIVING ALL THIS UNCERTAINTY IS CURRENT WEST COAST WAVE
EXPECTED TO RACE EAST ACROSS THE REGION...DEPARTING OFF TO OUR EAST
QUICKLY ON FRIDAY. TACKLING THE FIRST CONCERN (THERMAL FIELDS): MID
LEVEL WAVE ITSELF CONTINUES TO LOOK DISJOINTED ON ITS PASSAGE...
WHICH PROBABLY ACCOUNTS FOR CONTINUED RATHER WIDE RANGE IN EXACT
SURFACE LOW TRACK AND ATTENDANT LOW LEVEL THERMAL PROGS. 12Z ECWMF
EASILY FURTHEST SOUTH...KEEPING MAIN SURFACE WAVE TIED TO SOUTHERN
PORTION OF VORT LOBE...PASSING IT ACROSS SOUTHEAST LOWER MICHIGAN
EARLY FRIDAY MORNING. THIS SOLUTION WOULD SUGGEST MAINLY AN ALL SNOW
SCENARIO FOR AREAS ALONG AND NORTH OF M-32...WITH A RAIN/SNOW
MIXTURE FURTHER SOUTH (TRANSITION TO JUST RAIN DOWN NEAR SAGINAW
BAY). WHILE FURTHER NORTH...ALL OTHER AVAILABLE GUIDANCE OFFERING
VARIOUS THERMAL SOLUTIONS...WITH EVEN SOME OF THE NORTHERN MEMBERS
SHOWING EASTERN UPPER AND FAR NORTHERN LOWER MICHIGAN REMAINING ALL
SNOW. AS FOR THE SECOND CONCERN (FREEZING DRIZZLE POTENTIAL THURSDAY
MORNING): COULD EASILY ENVISION A LOSS OF DEEP SATURATION FOR A TIME
THURSDAY MORNING/EARLY THURSDAY AFTERNOON FOR NORTHERN LOWER AS
INITIAL WING OF STRONG WAA/CONVERGENCE PASSES BY TO OUR
NORTH...WAITING ON APPROACH OF MID LEVEL SUPPORT LATER IN THE DAY TO
DRIVE REEMERGENCE OF DEEPER MOISTURE. MODEL DERIVED SOUNDINGS
PARTIALLY CONCUR...WITH MOISTURE SHALLOWING OUT JUST ABOVE -10C.
THIS WOULD POTENTIALLY SET UP A FREEZING DRIZZLE SCENARIO BEFORE
SURFACE TEMPERATURES WARM...WHICH MAY BE A HIGH IMPACT TRAVEL EVENT
IF/WHERE WEDNESDAY NIGHTS SNOWS DO NOT MATERIALIZE. KINDA POINTLESS
TO INCLUDE THIS TYPE OF SPECIFICS JUST YET WHEN DEALING WITH
CONTINUED GUIDANCE CHAOS...BUT DEFINITELY SOMETHING TO KEEP AN EYE
ON. DESPITE WHAT HAPPENS THURSDAY AND THURSDAY EVENING...SURFACE LOW
BACKSIDE CAA AND ARRIVAL OF DEEPER MOISTURE SHOULD CHANGE ANY MIXED
PRECIP BACK TO SNOW FROM NORTHWEST TO SOUTHEAST THURSDAY
NIGHT...WITH A RAIN OR A MIXTURE HANGING ON LONGEST ACROSS THE FAR
SOUTHEAST. ANY LINGERING PRECIPITATION SHOULD END RATHER QUICKLY ON
FRIDAY.
SNOW AMOUNTS AND POSSIBLE HEADLINES: AS MENTIONED...JUST NOT OVERLY
IMPRESSED WITH DYNAMICS WITH THIS SYSTEM. MID LEVEL WAVE/SURFACE
REFLECTION BOTH APPEAR TO WEAKEN ON THEIR PASSAGE. SYSTEM DOES HAVE
A RATHER HEALTHY MOISTURE TAP WITH IT...WITH CONNECTION TO THE
WESTERN GULF OF MEXICO HELPING SPIKE PWAT VALUES TO NEAR THREE
QUARTERS OF AN INCH BY LATER THURSDAY. SHOULD BE A DECENT PRECIP
MAKER (NOTHING TOO HEAVY GIVING WEAKENING SUPPORT)...AND AS
MENTIONED YESTERDAY...WOULDN/T BE SURPRISED TO SEE SOME AREAS EXCEED
HALF INCH LIQUID EQUIVALENT AMOUNTS BY THE TIME EVERYTHING WRAPS UP
FRIDAY. OF COURSE...SNOW AMOUNTS ALL TIED TO THERMAL FIELDS...WITH
THE GREATEST SUPPORT FOR SIGNIFICANT SNOW ACCUMULATIONS ACROSS
EASTERN UPPER MICHIGAN. MUCH TOUGHER CALL ACROSS NORTHERN LOWER
MICHIGAN. GIVEN ARRAY OF UNCERTAINTIES...SIMPLY CANNOT JUSTIFY
MAKING SIGNIFICANT CHANGES TO INHERITED FORECAST...WHICH KEEPS THE
MAIN SNOW ACCUMULATIONS...ON THE ORDER OF 3 TO 5 INCHES...ACROSS
EASTERN UPPER MICHIGAN...WITH AMOUNTS ACROSS NORTHERN LOWER RANGING
FROM AN INCH OR TWO NEAR THE TIP OF THE MITT...TO JUST A DUSTING
SOUTH OF M-68. WHILE NOT FORTHCOMING ON THIS SHIFT...COULD
EVENTUALLY SEE THE NEED FOR AN ADVISORY FOR AREAS NORTH OF THE
BRIDGE.
REST OF THE FORECAST: WITH PRIMARY FOCUS ON EARLY PERIOD
SYSTEM...TOOK MORE OF A GENERIC GUIDANCE BLEND APPROACH FOR THE
WEEKEND INTO THE START OF NEXT WORK WEEK. CANADIAN HIGH PRESSURE
BUILDS INTO THE NORTHERN LAKES LATER FRIDAY THROUGH SATURDAY...WITH
ATTENDANT QUICK SHOT OF CAA. FORTUNATELY...THIS AIRMASS LOOKS TO BE
NOWHERE NEAR AS COLD AS ITS PREDECESSORS...AND HIGHS SATURDAY SHOULD
BE ABLE TO REACH WELL INTO THE 30S. THIS HIGH SHOULD KEEP NEXT WAVE
AND AXIS OF PRECIPITATION OFF TO OUR SOUTH TO START THE WEEKEND.
PLENTY OF QUESTIONS/UNCERTAINTY THERE-ON-AFTER...WITH SOME HINTS
SLOW SOUTHWARD MOVING BAROCLINIC AXIS WILL INTERACT WITH ADDITIONAL
ENERGY MOVING OUT OF THE ROCKIES...THE TWO WORKING IN TANDEM TO
DRIVE ANOTHER ROUND OF MIXED PRECIPITATION INTO OUR AREA TO START
NEXT WORK WEEK. DEPENDING ON JUST HOW FAR SOUTH AND QUICK THIS FRONT
MOVES INTO THE NORTHERN LAKES (IF IT DOES AT ALL) WILL DICTATE JUST
HOW "WARM" CONDITIONS BECOME SUNDAY AND MONDAY. CURRENT SUPPORT FOR
WIDESPREAD HIGHS REACHING INTO THE 40S BOTH DAYS OVER NORTHER LOWER
MICHIGAN...JUST A TOUCH COOLER NORTH OF THE STRAITS. LETS GET
THROUGH THIS FIRST SYSTEM...WITH PLENTY OF TIME TO REVISIT THESE
LATER PERIODS IN COMING DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 640 AM EDT WED MAR 26 2014
MAYBE JUST A VERY BRIEF MVFR CIG/FLURRY ALONG NW LOWER COAST EARLY
THIS MORNING. OTHERWISE...VFR FOR AWHILE...AS THE RETURN OF SKIES
TODAY WILL SEE CU/STRATOCU IN THE 4-5K RANGE...WITH INCREASING
HIGH LEVEL CLOUDS. THESE CLOUDS WILL THICKEN THROUGH TONIGHT DUE
TO AN INCOMING LOW PRESSURE SYSTEM. THIS SYSTEM WILL SPREAD SNOW
NORTH INTO NW LOWER/EASTERN UPPER LATE THIS EVENING...AND ACROSS
APN AFTER MIDNIGHT. CIGS AND VSBYS WILL DROP INTO IFR RANGE
THROUGH THE OVERNIGHT HOURS.
A SW BREEZE DEVELOPS DURING THE DAY WEDNESDAY...BECOMING LIGHTER
SE THAT EVENING. LLWS DEVELOPS AT ALL TAF SITES LATE IN THE
TAF.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...SMD
SYNOPSIS...MSB
SHORT TERM...SMD
LONG TERM...MSB
AVIATION...SMD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 AM EDT WED MAR 26 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
SRN HUDSON BAY THROUGH THE CNTRL GREAT LAKES INTO THE SE CONUS AND A
RIDGE OVER THE ROCKIES RESULTING IN NW FLOW THROUGH THE NRN GREAT
LAKES. AT THE SFC...ACYC WNW WINDS PREVAILED THROUGH UPPER MICHIGAN
AHEAD OF A RIDGE BUILDING INTO THE UPPER MS VALLEY. IN THE COLD
AIRMASS WITH 850 MB TEMPS TO AROUND -23C...DIURNAL CLOUD AND
FLURRIES HAD DEVELOPED OVER MUCH OF THE REGION. HOWEVER...LITTLE OR
NO ACCUMULATION HAS OCCURRED SINCE EARLY AFTERNOON.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...EXPECT THE LIGHT SNOW
SHOWERS OR FLURRIES TO DIMINISH AND THE CLOUDS TO ALSO GRADUALLY
DISSIPATE. AS THE HIGH PRES RIDGE BUILDS INTO THE AREA AND WINDS
BECOME LIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS WILL DEVELOP.
WITH PWAT VALUES AOB 0.10 INCH...EXPECT TEMPS WILL DROP OFF TO
VALUES WELL BELOW GUIDANCE...ESPECIALLY AT THE TYPICAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR.
WEDNESDAY...WAA WILL DEVELOP AS THE PATTERN DEAMPLIFIES. DESPITE
SOME INCREASE IN MID/HIGH CLOUDS...THE COMBINATION OF SRLY FLOW AND
LIMITED SUNSHINE SHOULD BOOST TEMPS BACK INTO THE MID 20 TO AROUND
30. DURING THE AFTERNOON 285K-290K ISENTRROPIC LIFT MAY BE STRONG
ENOUGH TO PRODUCE SOME LIGHT SNOW. HOWEVER...WITH THE DRY LOWER
LEVELS...ONLY SLIGHT CHANCE POPS WERE MENTIONED LATE OVER THE WEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 423 PM EDT TUE MAR 25 2014
A LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES REGION WILL
CONTROL THE FIRST PART OF THE LONG TERM FORECAST. THIS LOW...WHICH
WILL BE AROUND 989MB IN WESTERN NEBRASKA AT 00Z THURSDAY...WILL
SLIDE AN ELONGATED TROUGH NORTHEAST THROUGH NORTHWEST MINNESOTA AT
THE SAME TIME. THIS TROUGH WILL BE ASSOCIATED WITH THE FIRST WAVE
OF PRECIPITATION ASSOCIATED WITH THE SYSTEM. AS THIS TROUGH SLIDES
EAST ON WEDNESDAY NIGHT AND OVER FAR WESTERN LAKE SUPERIOR BY 12Z
THURSDAY...BROAD WARM AIR ADVECTION ON THE 850-600MB LEVELS AND
ISENTROPIC ASCENT ON THE THE 275-295K SFCS WILL SLIDE
EAST-NORTHEAST THROUGH THE CWA. WOULD EXPECT THE SNOW TO SLIDE INTO
THE NORTHERN HALF OF THE CWA DURING THE EVENING HOURS AND THEN GET
ADDITIONAL DEVELOPMENT OVER THE EAST DURING THE OVERNIGHT HOURS AS
THE WAA BECOMES MAXIMIZED/FOCUSED THERE. QPF IN THESE WAA EVENTS IS
ALWAYS TRICKY AND THE MODELS HAVE BEEN STRUGGLING ON THE EXACT
AMOUNTS/LOCATIONS...SO HAVE FOCUSED ON WHERE THE FORCING IS
MAXIMIZED WITH THE HIGHEST POPS/QPF. IN ADDITION FOR THE
EAST...THERE MAY BE ENOUGH LINGERING COLD AIR WITH THE SOUTHERLY
WINDS OFF THE PATCH OF OPEN WATER OVER NORTHWEST LAKE MICHIGAN TO
LEAD TO A LITTLE BIT OF ENHANCEMENT. OVERALL...HAVE SNOWFALL
AMOUNTS OF 0.5-2.5 INCHES FOR THE WEDNESDAY NIGHT PERIOD...WITH THE
LOWEST VALUES ALONG THE WI BORDER AND THE HIGHEST OVER THE KEWEENAW
AND LUCE COUNTIES. ONE ITEM OF NOTE IS THE MODELS ARE SHOWING THE
DEEP MOISTURE CUTTING OUT FROM THE SOUTH DURING THE OVERNIGHT HOURS.
THIS WOULD LEAD TO A TRANSITION TO A FREEZING RAIN/DRIZZLE SITUATION
UNTIL THE LOW LEVEL TEMPERATURES CAN WARM ON THURSDAY MORNING.
HEADING INTO THURSDAY...THE SURFACE TROUGH WILL SHIFT EAST ACROSS
THE CWA WHILE THE SURFACE LOW IS MOVING NORTHEAST INTO
SOUTHERN WISCONSIN BY THURSDAY EVENING. 12Z GFS REMAINS THE FASTEST
SOLUTION AND MOVING THE LOW NORTHEAST THROUGH NORTHWEST LOWER
MICHIGAN THURSDAY EVENING...WHILE THE NAM IS WAY TO THE NW. THE 12Z
GEM/ECMWF MEANWHILE ARE MUCH SLOWER AND TRACK THE LOW THROUGH THE
NORTHERN/CENTRAL OF LOWER MICHIGAN RESPECTIVELY LATE THURSDAY
NIGHT. WITH THE EXTREMELY WELL CLUSTERED 00Z ECMWF ENSEMBLE MEMBERS
ON THE LOW TRACK...HAVE A HARD TIME GOING MUCH AWAY FROM THAT IDEA
ALTHOUGH THE 12Z ECMWF WAS FARTHER SOUTHEAST. THUS...LIKE YESTERDAY
WILL FOLLOW THE SLOWER IDEA FOR TIMING AND THEN A BLEND OF THE
ECMWF/GFS/GEM FOR THE LOW TRACK.
AS FOR HOW THE PRECIPITATION WILL EVOLVE...EXPECT THERE TO BE SOME
WAA PRECIPITATION CONTINING INTO THE MORNING HOURS OVER THE EASTERN
CWA...BUT MODELS DO HINT AT THE DEEPER MOISTURE BEGINNING TO CUT
OUT OVER THE REST OF WESTERN/CENTRAL CWA AND WOULD EXPECT A
TRANSITION AWAY FROM SNOW AND TOWARDS A MIX OR RAIN/DRIZZLE. THAT
SIMILAR IDEA OF LIQUID PRECIP FOR THE MORNING SEEMS REASONABLE WITH
THE LACK OF DEEP MOISTURE AND MUCH OF THE CLOUD LAYER BELOW THE
FAVORED ICE CRYSTAL TEMPERATURES. SINCE THIS IDEA HAS BEEN SHOWN
OVER THE LAST DAY...TRANSITIONED THAT AREA TO MORE RAIN/DRIZZLE THAN
SNOW FOR THURSDAY MORNING. SURFACE TEMPERATURES WILL BE NEAR OR
SLIGHTLY BELOW FREEZING AT INITIALLY THURSDAY MORNING...SO THERE
COULD BE A FEW HOUR PERIOD OF FREEZING DRIZZLE...BUT WITH SOME
SNOW LIKELY OCCURRING EARLIER THE IMPACTS SHOULD BE LIMITED. FARTHER
WEST...WOULD EXPECT THERE TO BE A STRONG BAND OF PRECIPITATION
(MAINLY SNOW) ALONG THE WEST SIDE OF THE SURFACE TROUGH. THIS BAND
WILL BE OVER WESTERN LAKE SUPERIOR LATE WEDNESDAY NIGHT AND THEN
SHIFT EAST AND ONSHORE OVER THE FAR WEST ON THURSDAY MORNING. THIS
EASTWARD SHIFT WILL CONTINUE THROUGH THE AFTERNOON/EVENING HOURS
ACROSS THE REST OF THE CWA AND WOULD EXPECT SOME INTENSIFICATION OF
THE BAND DUE TO THE SHORTWAVE TROUGH EXPECTED TO PULL NORTHEAST WITH
THE SURFACE LOW AND INTO THE GREAT LAKES REGION. OUR CWA WILL BE ON
THE NORTHERN EDGE OF THAT WAVE...BUT THERE SHOULD STILL BE SOME
INFLUENCE. THEN AS THE LOW PULLS OUT OF LOWER MICHIGAN LATE THURSDAY
NIGHT AND FRIDAY MORNING...THE PRECIPITATION WILL FOLLOW SUIT AND
SHOULD BE MAINLY OUT OF THE CWA BY 12Z FRIDAY. THERE COULD BE SOME
LIGHT UPSLOPE SNOW UNDER THE NW WINDS ON FRIDAY OVER THE NW/NC U.P.
BUT WITH LITTLE HELP FROM LAKE ENHANCEMENT (MARGINAL 850MB TEMPS
AROUND -10C)...LITTLE OPEN WATER...AND DRY AIR MOVING IN FROM THE
APPROACHING HIGH WILL QUICKLY DIMINISH POPS FRIDAY MORNING.
NOW FOR PCPN AMOUNTS/TYPE. QPF AMOUNTS FOR THURSDAY INTO THURSDAY
NIGHT WILL LIKELY BE AROUND 0.33-0.66 (HEAVIEST EAST)...BUT THERE
COULD BE SOME LOCALIZED HIGHER AMOUNTS IN ANY BANDED LOCATIONS ALONG
THE SURFACE TROUGH. WITH DIFFERING IDEAS FROM THE MODELS ON HOW TO
HANDLE THE LOW-MID LEVEL WARMING...HAVE BEEN STRUGGLING WITH HOW
MUCH RAIN TO PUT IN THE FORECAST. GEM CONTINUES TO SHOW THE WARMEST
THERMAL PROFILE AND WOULD PUT RAIN OVER MUCH OF THE CWA. ECMWF/GFS
IN DECENT AGREEMENT THROUGH MUCH OF THURSDAY BEFORE THE FASTER GFS
QUICKLY PULLS COLD AIR INTO THE CWA. THE ECMWF SOLUTION WOULD KEEP
THE PRECIPITATION ASSOCIATED WITH THE FGEN/TROUGH AS MAINLY SNOW
AND THAT SEEMS REASONABLE WITH THE EXPECTED INTENSITY AS THAT
STRONGER BAND MOVES THROUGH. BEFORE THE TROUGH ARRIVES AND THE
EXPECTED LOSS OF DEEP MOISTURE...WILL HOLD ONTO SOME RAIN OVER
THE CENTRAL AND SHIFT IT EAST THROUGH THE DAY. OVER THE SOUTH
CENTRAL (MENOMINEE COUNTY)...THINK THEY WOULD HAVE BEST OPPORTUNITY
TO SEE AT LEAST HALF OF THE THURSDAY AFTERNOON PRECIP AS RAIN UNTIL
THE COLD AIR SURGES IN THURSDAY EVENING. THE P-TYPE MAKES THE
SNOWFALL FORECAST TRICKY...BUT THE GOING FORECAST HAS 1-4 INCHES
OVER MOST OF THE AREA AND SOME HIGHER AMOUNTS WHERE THE PRECIP WILL
BE ALL SNOW (KEWEENAW PENINSULA AND LUCE COUNTY). WILL CONTINUE TO
MENTION IN THE HWO...ALTHOUGH ADJUST THE WORDING TO HIGHLIGHT THE
FREEZING RAIN POTENTIAL LATE WEDNESDAY NIGHT INTO THURSDAY MORNING.
ALL IN ALL...IT APPEARS THAT IT WILL MAINLY BE AN ADVISORY TYPE
EVENT.
AS FOR THE REST OF THE FORECAST PERIOD...THE HIGH PRESSURE RIDGE
WILL LEAD TO CLEARING SKIES ON FRIDAY AFTERNOON/EVENING AND A QUIET
PERIOD OF WEATHER HEADING INTO SATURDAY. A TRANSITION TO MORE ZONAL
FLOW ON SATURDAY COULD SET THE STAGE FOR A BRIEF PERIOD OF PRECIP
ASSOCIATED WITH A SHORTWAVE MOVING EAST ALONG THE US/CANADIAN
BORDER ON SATURDAY NIGHT. BEST OPPORTUNITY WOULD BE OVER THE
NORTHERN HALF OF LAKE SUPERIOR AND WILL ONLY HAVE SLIGHT CHANCES
OVER THE NORTHERN PART OF THE CWA. WARM SOUTHWESTERLY FLOW AHEAD OF
A COLD FRONT THAT WILL MOVE THROUGH ON SUNDAY NIGHT WILL LEAD TO
NORMAL TO ABOVE NORMAL HIGHS ON SUNDAY. ECMWF/GEM CONTINUE TO
HANDLE HIGHS WELL THIS DAY (MID-UPPER 40S OVER THE WEST HALF OF
UPPER MICHIGAN)...WHILE THE GFS IS HEAVILY BIASED BY ITS SNOW COVER
KEEPING TEMPS DOWN. WILL CONTINUE TO FOCUS ON GEM/ECMWF TEMPS FOR
HIGHS.
AS THE COLD FRONT MOVES THROUGH ON SUNDAY NIGHT...SHOULD SEE SOME
PRECIPITATION ASSOCIATED WITH IT. THERMAL PROFILE WOULD SUPPORT
RAIN TRANSITIONING TO SNOW FROM WEST TO EAST THROUGH THE NIGHT AND
INTO MONDAY MORNING. MODELS DIFFER MORE ON THE EVOLUTION OF THE
UPPER TROUGH AND ASSOCIATED SURFACE LOW HEADING INTO MONDAY...WITH
THE 12Z ECMWF DIGGING IT MUCH FARTHER SOUTH (MID MISSISSIPPI
VALLEY) WHILE THE 12Z GFS HAS IT IN THE GREAT LAKES REGION. WILL
FOLLOW A GENERAL BLEND OF THE TWO FOR NOW. BEHIND THE WAVE...HIGH
PRESSURE WILL START TO MOVE IN ON TUESDAY AND TEMPERATURES WILL FALL
BACK TO BELOW NORMAL VALUES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1232 AM EDT WED MAR 26 2014
HIGH PRESSURE CONTINUES TO SLOWLY BUILD INTO THE CENTRAL U.S.
OVERNIGHT WITH SFC PRESSURE GRADIENT OVER UPPER MICHIGAN REMAINING
RELAXED THROUGH THE MORNING. ISOLATED FLURRIES CONTINUE TO LINGER
OVER THE REGION BUT WILL COME TO AN END AS DRIER AIR MOVES IN. AS
THE SFC HIGH PASSES TOT HE SOUTH OF THE REGION...RIDGE AXIS SLIDES
ACROSS THE U.P. OVERNIGHT AND WEDNESDAY MORNING WITH VFR CONDITIONS
PREVAILING THROUGH 0Z. APPROACHING LOW PRESSURE SYSTEM TO BRING IN
INCREASING CLOUDS...BUT EXPECT CIGS TO STAY ABOVE MVFR THROUGH THE
END OF THE FORECAST. ALL THREE TAF SITES TO SEE SOME LIGHT SNOW
DEVELOPING AFTER 0Z HOWEVER VSBYS TO REMAIN VFR THROUGH 6Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 401 AM EDT WED MAR 26 2014
THE RIDGE ACROSS THE UPPER GREAT LAKES WILL SHIFT TO THE LOWER GREAT
LAKES THIS EVENING...AS LOW PRESURE ORGANIZES ACROSS THE CENTRAL
PLAINS. EXPECT THE LOW TO SLIDE ACROSS IA ON THURSDAY WHILE
EXTENDING A TROUGH ACROSS LAKE SUPERIOR. THE LOW WILL THEN TRACK
ACROSS LOWER MI AND LAKE HURON THURSDAY NIGHT INTO FRIDAY MORNING.
HIGH PRESSURE ACROSS SOUTH CENTRAL CANADA...NORTH DAKOTA...AND
MINNESOTA AROUND DAYBREAK FRIDAY WILL SHIFT ACROSS THE UPPER GREAT
LAKES FRIDAY NIGHT. IN BETWEEN THE EXITING LOW AND NEARING HIGH...A
FEW NW GALE FORCE GUSTS TO 35KTS WILL BE POSSIBLE OVER MAINLY E LAKE
SUPERIOR LATE THURSDAY NIGHT-FRIDAY MORNING. THE AREA OF HIGH
PRESSURE WILL THEN SLOWLY MOVE INTO QUEBEC OVER THE WEEKEND AS THE
NEXT LOW PRESSURE SYSTEM NEARS FROM THE PLAINS STATES ON SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...RJT
MARINE...KF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
344 AM EDT WED MAR 26 2014
.SYNOPSIS...
ISSUED AT 343 AM EDT WED MAR 26 2014
HIGH PRESSURE TODAY WILL GIVE WAY TO AN APPROACHING STORM SYSTEM
TONIGHT...WHICH WILL PASS THROUGH THE REGION BY FRIDAY MORNING. THIS
SYSTEM WILL BRING A WINTRY MIX OF PRECIPITATION ACROSS NORTHERN
MICHIGAN...WITH PRIMARILY SNOW EXPECTED ACROSS EASTERN UPPER
MICHIGAN...AND A RAIN AND SNOW MIXTURE FURTHER SOUTH. HIGH PRESSURE
AND DRY WEATHER RETURNS OVER THE WEEKEND...WITH TEMPERATURES
RETURNING TO MORE SEASONAL LEVELS BY SUNDAY AND MONDAY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 343 AM EDT WED MAR 26 2014
...MODERATING TEMPERATURES WITH NEW STORM AND NEW SNOW DEVELOPING
TONIGHT AND POSSIBLY SOME FREEZING DRIZZLE...
IMPACTS: SLICK AND SNOW COVERED ROADS BY DAYBREAK...ESPECIALLY
EASTERN UPPER WHERE BETTER ACCUMULATIONS ARE ANTICIPATED.
CONFIDENCE: DECENT ON LOCATION OF SNOW AND BETTER ACCUMULATIONS.
LESS CONFIDENCE ON EXTENT OF SNOW/PRECIPITATION ALONG
M-55...ESPECIALLY OVER NEARER THE SAGINAW BAY. CONFIDENCE NOT TOO
HIGH ON FREEZING DRIZZLE EITHER...BUT IMPACT OF THAT LOOKS MINIMAL.
CURRENT WEATHER AND SYNOPTIC PATTERN/EVOLUTION:
UPPER LEVEL TROUGHING IS EXITING EAST OVERNIGHT...WITH RISING MID
LEVEL HEIGHTS THAT WILL CONTINUE RISING THROUGH THE DAY. LIGHTER
WINDS WITH SFC HIGH PRESSURE TO GET REPLACED BY INCREASING
WAA...ESPECIALLY TONIGHT...AHEAD OF DEEPENING SFC LOW PRESSURE INTO
THE CENTRAL PLAINS OVERNIGHT. A WARM FRONT WILL GET BLASTED
NORTHWARD INTO THE WESTERN/SOUTHERN GREAT LAKES...AIDED ALONG BY
STRENGTHENING SW LOW LEVEL WINDS OF 50+ KTS FEEDING INCREASING GULF
OF MEXICO MOISTURE INTO THE GREAT LAKES. TWO DISTINCT SHORTWAVES ARE
SEEN FOR TONIGHT...ONE LIFTING THROUGH THE OHIO RIVER VALLEY...AND
ANOTHER MORE DEFINED WAVE...ASSOCIATED WITH THE MAIN SFC LOW INTO
THE PLAINS. THERE WILL BE SOME WEAKER SHORTWAVE ENERGY LIFTING IN
ACROSS THE U.S. CANADIAN BORDER...BUT OVERALL DEEP LAYER -DIVQ NOT
OUT OF THIS WORLD...AS IT WILL BE ALIGNED ALONG AN INVERTED SFC
TROUGH AXIS FROM THE SFC LOW INTO THE FAR WESTERN GREAT LAKES. NRN
MICHIGAN FORCING WILL BE DRIVEN MOSTLY BY WAA.
WEATHER EXPECTATIONS:
LINGERING PATCHY LAKE DRIVEN CLOUDS WILL BE AROUND THE NW LOWER
COASTLINE THIS MORNING...WITH A CHANGEOVER TO SCATTERED DIURNALLY
DRIVEN CUMULUS THIS MORNING/EARLY AFTERNOON. HIGH LEVEL CIRRUS
CLOUDS WILL ALSO START THICKENING UP LATER TODAY. TEMPERATURES WILL
REACH THE LOWER 20S IN EASTERN UPPER...TO NEAR 30F IN AND AROUND THE
GTV BAY. CLOUDS THICKEN THROUGH THE EVENING...WITH SOME LIGHT SNOWS
LIKELY BREAKING OUT ACROSS EASTERN UPPER AND NW LOWER LATE IN THE
EVENING. THESE SNOWS WILL PICK UP IN INTENSITY THROUGH THE OVERNIGHT
HOURS. THINGS ARE LESS CLEAR ACROSS THE SE CWA...ESPECIALLY CLOSER
TO SAG BAY...BUT LIKELY LIGHT SNOWS FOR AT LEAST A PERIOD OF TIME.
ALTHOUGH NOT A CLASSIC PATTERN...MAYBE SOME FREEZING DRIZZLE AND
LIGHT SNOW TOWARD DAYBREAK ACROSS A GOOD CHUNK OF NRN LOWER.
SNOW AMOUNTS...STILL LOOK PRETTY GOOD BASED ON LATEST DATA. GENERAL
1-3 INCHES...MAX IN HIGHER TERRAIN OF INTERIOR NRN LOWER INTO THE
STRAITS AND PARTS OF EASTERN UPPER. LESS THAN AN INCH NEARER THE SAG
BAY.
&&
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM EDT WED MAR 26 2014
...ACTIVE PERIOD OF WEATHER FORTHCOMING...
HIGH IMPACT WEATHER POTENTIAL: SIGNIFICANT MIXED PRECIPITATION EVENT
THURSDAY THROUGH EARLY FRIDAY. SEVERAL INCHES OF WET SNOW
ACCUMULATION REMAINS POSSIBLE...ESPECIALLY FOR EASTERN UPPER.
OVERVIEW: CHANGE TO A MORE ACTIVE...ALBEIT MILDER...PATTERN STARTING
TO KICK INTO OVERDRIVE...WITH NOAM WATER VAPOR IMAGERY CONFIRMING
HIGH RES RUC GUIDANCE OF DEEPENING FAR WEST ATLANTIC STORM...ALL THE
WHILE WESTERN RIDGING HAS ESSENTIALLY SUCCUMBED TO STRONG PACIFIC
ENERGY PUSHING INTO THE PACIFIC NORTHWEST. THE FORMER WILL
ESSENTIALLY ACT AS A SLING-SHOT...PROPELLING OVERHEAD TROUGHING/COLD
POOL TO THE NORTHEAST AS IT UNDERGOES EXPLOSIVE DEEPENING ON ITS WAY
TO THE CANADIAN MARITIMES. UNFORTUNATELY...WHILE THE LATTER LOOKS TO
BRING IN SOME "MILDER" AIR AS IT PUSHES EAST ACROSS THE CONUS...IT
ALSO LOOKS TO DRUM UP SOME SIGNIFICANT LATE WINTER TYPE WEATHER
ACROSS OUR AREA TO END THIS WORK WEEK. OPEN FOR BUSINESS PACIFIC
MEANS ACTIVE WEATHER COULD CONTINUE FOR THE FORECASTABLE FUTURE...
AND WITH COLD AIR LURKING JUST TO OUR NORTH...SETS UP POTENTIAL FOR
ADDITIONAL MESSY MIXED PRECIP EVENTS HEADING INTO NEXT WEEK. WE
SHALL SEE.
PRIMARY FORECAST CONCERNS/CHALLENGES: PLENTY...WITH EMPHASIS NO
DOUBT CENTERED ON PRECIPITATION TYPE/AMOUNTS/AND TIMING OF EXPECTED
LATE SEASON WINTER STORM THURSDAY THROUGH EARLY FRIDAY. HEADLINE
POTENTIAL WILL ALSO NEED TO BE ADDRESSED.
DETAILS: UNFORTUNATELY...STILL ONE VERY CHALLENGING...AND HENCE
RATHER LOW CONFIDENCE FORECAST HEADING THROUGH THURSDAY AND THURSDAY
EVENING. PROBLEMS ARE REALLY TWO-FOLD...CENTERING ON EXACT THERMAL
PROPERTIES AND EVIDENCE DEEP MOISTURE MAY DEPART FOR A TIME THURSDAY
MORNING...LEAVING OPEN AN OPPORTUNITY FOR SOME FREEZING DRIZZLE.
SYSTEM DRIVING ALL THIS UNCERTAINTY IS CURRENT WEST COAST WAVE
EXPECTED TO RACE EAST ACROSS THE REGION...DEPARTING OFF TO OUR EAST
QUICKLY ON FRIDAY. TACKLING THE FIRST CONCERN (THERMAL FIELDS): MID
LEVEL WAVE ITSELF CONTINUES TO LOOK DISJOINTED ON ITS PASSAGE...
WHICH PROBABLY ACCOUNTS FOR CONTINUED RATHER WIDE RANGE IN EXACT
SURFACE LOW TRACK AND ATTENDANT LOW LEVEL THERMAL PROGS. 12Z ECWMF
EASILY FURTHEST SOUTH...KEEPING MAIN SURFACE WAVE TIED TO SOUTHERN
PORTION OF VORT LOBE...PASSING IT ACROSS SOUTHEAST LOWER MICHIGAN
EARLY FRIDAY MORNING. THIS SOLUTION WOULD SUGGEST MAINLY AN ALL SNOW
SCENARIO FOR AREAS ALONG AND NORTH OF M-32...WITH A RAIN/SNOW
MIXTURE FURTHER SOUTH (TRANSITION TO JUST RAIN DOWN NEAR SAGINAW
BAY). WHILE FURTHER NORTH...ALL OTHER AVAILABLE GUIDANCE OFFERING
VARIOUS THERMAL SOLUTIONS...WITH EVEN SOME OF THE NORTHERN MEMBERS
SHOWING EASTERN UPPER AND FAR NORTHERN LOWER MICHIGAN REMAINING ALL
SNOW. AS FOR THE SECOND CONCERN (FREEZING DRIZZLE POTENTIAL THURSDAY
MORNING): COULD EASILY ENVISION A LOSS OF DEEP SATURATION FOR A TIME
THURSDAY MORNING/EARLY THURSDAY AFTERNOON FOR NORTHERN LOWER AS
INITIAL WING OF STRONG WAA/CONVERGENCE PASSES BY TO OUR
NORTH...WAITING ON APPROACH OF MID LEVEL SUPPORT LATER IN THE DAY TO
DRIVE REEMERGENCE OF DEEPER MOISTURE. MODEL DERIVED SOUNDINGS
PARTIALLY CONCUR...WITH MOISTURE SHALLOWING OUT JUST ABOVE -10C.
THIS WOULD POTENTIALLY SET UP A FREEZING DRIZZLE SCENARIO BEFORE
SURFACE TEMPERATURES WARM...WHICH MAY BE A HIGH IMPACT TRAVEL EVENT
IF/WHERE WEDNESDAY NIGHTS SNOWS DO NOT MATERIALIZE. KINDA POINTLESS
TO INCLUDE THIS TYPE OF SPECIFICS JUST YET WHEN DEALING WITH
CONTINUED GUIDANCE CHAOS...BUT DEFINITELY SOMETHING TO KEEP AN EYE
ON. DESPITE WHAT HAPPENS THURSDAY AND THURSDAY EVENING...SURFACE LOW
BACKSIDE CAA AND ARRIVAL OF DEEPER MOISTURE SHOULD CHANGE ANY MIXED
PRECIP BACK TO SNOW FROM NORTHWEST TO SOUTHEAST THURSDAY
NIGHT...WITH A RAIN OR A MIXTURE HANGING ON LONGEST ACROSS THE FAR
SOUTHEAST. ANY LINGERING PRECIPITATION SHOULD END RATHER QUICKLY ON
FRIDAY.
SNOW AMOUNTS AND POSSIBLE HEADLINES: AS MENTIONED...JUST NOT OVERLY
IMPRESSED WITH DYNAMICS WITH THIS SYSTEM. MID LEVEL WAVE/SURFACE
REFLECTION BOTH APPEAR TO WEAKEN ON THEIR PASSAGE. SYSTEM DOES HAVE
A RATHER HEALTHY MOISTURE TAP WITH IT...WITH CONNECTION TO THE
WESTERN GULF OF MEXICO HELPING SPIKE PWAT VALUES TO NEAR THREE
QUARTERS OF AN INCH BY LATER THURSDAY. SHOULD BE A DECENT PRECIP
MAKER (NOTHING TOO HEAVY GIVING WEAKENING SUPPORT)...AND AS
MENTIONED YESTERDAY...WOULDN/T BE SURPRISED TO SEE SOME AREAS EXCEED
HALF INCH LIQUID EQUIVALENT AMOUNTS BY THE TIME EVERYTHING WRAPS UP
FRIDAY. OF COURSE...SNOW AMOUNTS ALL TIED TO THERMAL FIELDS...WITH
THE GREATEST SUPPORT FOR SIGNIFICANT SNOW ACCUMULATIONS ACROSS
EASTERN UPPER MICHIGAN. MUCH TOUGHER CALL ACROSS NORTHERN LOWER
MICHIGAN. GIVEN ARRAY OF UNCERTAINTIES...SIMPLY CANNOT JUSTIFY
MAKING SIGNIFICANT CHANGES TO INHERITED FORECAST...WHICH KEEPS THE
MAIN SNOW ACCUMULATIONS...ON THE ORDER OF 3 TO 5 INCHES...ACROSS
EASTERN UPPER MICHIGAN...WITH AMOUNTS ACROSS NORTHERN LOWER RANGING
FROM AN INCH OR TWO NEAR THE TIP OF THE MITT...TO JUST A DUSTING
SOUTH OF M-68. WHILE NOT FORTHCOMING ON THIS SHIFT...COULD
EVENTUALLY SEE THE NEED FOR AN ADVISORY FOR AREAS NORTH OF THE
BRIDGE.
REST OF THE FORECAST: WITH PRIMARY FOCUS ON EARLY PERIOD
SYSTEM...TOOK MORE OF A GENERIC GUIDANCE BLEND APPROACH FOR THE
WEEKEND INTO THE START OF NEXT WORK WEEK. CANADIAN HIGH PRESSURE
BUILDS INTO THE NORTHERN LAKES LATER FRIDAY THROUGH SATURDAY...WITH
ATTENDANT QUICK SHOT OF CAA. FORTUNATELY...THIS AIRMASS LOOKS TO BE
NOWHERE NEAR AS COLD AS ITS PREDECESSORS...AND HIGHS SATURDAY SHOULD
BE ABLE TO REACH WELL INTO THE 30S. THIS HIGH SHOULD KEEP NEXT WAVE
AND AXIS OF PRECIPITATION OFF TO OUR SOUTH TO START THE WEEKEND.
PLENTY OF QUESTIONS/UNCERTAINTY THERE-ON-AFTER...WITH SOME HINTS
SLOW SOUTHWARD MOVING BAROCLINIC AXIS WILL INTERACT WITH ADDITIONAL
ENERGY MOVING OUT OF THE ROCKIES...THE TWO WORKING IN TANDEM TO
DRIVE ANOTHER ROUND OF MIXED PRECIPITATION INTO OUR AREA TO START
NEXT WORK WEEK. DEPENDING ON JUST HOW FAR SOUTH AND QUICK THIS FRONT
MOVES INTO THE NORTHERN LAKES (IF IT DOES AT ALL) WILL DICTATE JUST
HOW "WARM" CONDITIONS BECOME SUNDAY AND MONDAY. CURRENT SUPPORT FOR
WIDESPREAD HIGHS REACHING INTO THE 40S BOTH DAYS OVER NORTHER LOWER
MICHIGAN...JUST A TOUCH COOLER NORTH OF THE STRAITS. LETS GET
THROUGH THIS FIRST SYSTEM...WITH PLENTY OF TIME TO REVISIT THESE
LATER PERIODS IN COMING DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1157 PM EDT TUE MAR 25 2014
SOME RESTRICTIONS IN -SHSN TONIGHT TVC/MBL. -SN DEVELOPING LATE
WED EVENING MBL/TVC. OTHERWISE VFR.
COLD HIGH PRESSURE IN THE MID MS VALLEY WILL MOVE EAST THRU
WEDNESDAY. LINGERING NW FLOW LAKE EFFECT CLOUDS/SHSN WILL
WANE VERY LATE TONIGHT AS WINDS START TO BACK AND THE AIRMASS GETS
DRIER. BRIEF CIG/VSBY RESTRICTIONS POSSIBLE AT TVC/MBL OVERNIGHT.
OTHERWISE VFR...AS THE RETURN OF CU/STRATOCU ON WEDNESDAY WILL BE
IN THE 4-5K RANGE. AN INCOMING LOW PRESSURE SYSTEM WILL SPREAD
SNOW NORTH INTO LOWER MI WED NIGHT...LEADING PORTION OF THIS WILL
REACH MBL/TVC TOWARD THE TAIL END OF THE TAF PERIOD.
A SW BREEZE DEVELOPS DURING THE DAY WEDNESDAY...BECOMING LIGHTER
SE THAT EVENING. LLWS DEVELOPS AT MBL VERY LATE IN THE TAF...WITH
STRONGER SSW WINDS JUST OFF THE DECK.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...MSB
SHORT TERM...SMD
LONG TERM...MSB
AVIATION...JZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1232 AM EDT WED MAR 26 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
SRN HUDSON BAY THROUGH THE CNTRL GREAT LAKES INTO THE SE CONUS AND A
RIDGE OVER THE ROCKIES RESULTING IN NW FLOW THROUGH THE NRN GREAT
LAKES. AT THE SFC...ACYC WNW WINDS PREVAILED THROUGH UPPER MICHIGAN
AHEAD OF A RIDGE BUILDING INTO THE UPPER MS VALLEY. IN THE COLD
AIRMASS WITH 850 MB TEMPS TO AROUND -23C...DIURNAL CLOUD AND
FLURRIES HAD DEVELOPED OVER MUCH OF THE REGION. HOWEVER...LITTLE OR
NO ACCUMULATION HAS OCCURRED SINCE EARLY AFTERNOON.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...EXPECT THE LIGHT SNOW
SHOWERS OR FLURRIES TO DIMINISH AND THE CLOUDS TO ALSO GRADUALLY
DISSIPATE. AS THE HIGH PRES RIDGE BUILDS INTO THE AREA AND WINDS
BECOME LIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS WILL DEVELOP.
WITH PWAT VALUES AOB 0.10 INCH...EXPECT TEMPS WILL DROP OFF TO
VALUES WELL BELOW GUIDANCE...ESPECIALLY AT THE TYPICAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR.
WEDNESDAY...WAA WILL DEVELOP AS THE PATTERN DEAMPLIFIES. DESPITE
SOME INCREASE IN MID/HIGH CLOUDS...THE COMBINATION OF SRLY FLOW AND
LIMITED SUNSHINE SHOULD BOOST TEMPS BACK INTO THE MID 20 TO AROUND
30. DURING THE AFTERNOON 285K-290K ISENTRROPIC LIFT MAY BE STRONG
ENOUGH TO PRODUCE SOME LIGHT SNOW. HOWEVER...WITH THE DRY LOWER
LEVELS...ONLY SLIGHT CHANCE POPS WERE MENTIONED LATE OVER THE WEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 423 PM EDT TUE MAR 25 2014
A LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES REGION WILL
CONTROL THE FIRST PART OF THE LONG TERM FORECAST. THIS LOW...WHICH
WILL BE AROUND 989MB IN WESTERN NEBRASKA AT 00Z THURSDAY...WILL
SLIDE AN ELONGATED TROUGH NORTHEAST THROUGH NORTHWEST MINNESOTA AT
THE SAME TIME. THIS TROUGH WILL BE ASSOCIATED WITH THE FIRST WAVE
OF PRECIPITATION ASSOCIATED WITH THE SYSTEM. AS THIS TROUGH SLIDES
EAST ON WEDNESDAY NIGHT AND OVER FAR WESTERN LAKE SUPERIOR BY 12Z
THURSDAY...BROAD WARM AIR ADVECTION ON THE 850-600MB LEVELS AND
ISENTROPIC ASCENT ON THE THE 275-295K SFCS WILL SLIDE
EAST-NORTHEAST THROUGH THE CWA. WOULD EXPECT THE SNOW TO SLIDE INTO
THE NORTHERN HALF OF THE CWA DURING THE EVENING HOURS AND THEN GET
ADDITIONAL DEVELOPMENT OVER THE EAST DURING THE OVERNIGHT HOURS AS
THE WAA BECOMES MAXIMIZED/FOCUSED THERE. QPF IN THESE WAA EVENTS IS
ALWAYS TRICKY AND THE MODELS HAVE BEEN STRUGGLING ON THE EXACT
AMOUNTS/LOCATIONS...SO HAVE FOCUSED ON WHERE THE FORCING IS
MAXIMIZED WITH THE HIGHEST POPS/QPF. IN ADDITION FOR THE
EAST...THERE MAY BE ENOUGH LINGERING COLD AIR WITH THE SOUTHERLY
WINDS OFF THE PATCH OF OPEN WATER OVER NORTHWEST LAKE MICHIGAN TO
LEAD TO A LITTLE BIT OF ENHANCEMENT. OVERALL...HAVE SNOWFALL
AMOUNTS OF 0.5-2.5 INCHES FOR THE WEDNESDAY NIGHT PERIOD...WITH THE
LOWEST VALUES ALONG THE WI BORDER AND THE HIGHEST OVER THE KEWEENAW
AND LUCE COUNTIES. ONE ITEM OF NOTE IS THE MODELS ARE SHOWING THE
DEEP MOISTURE CUTTING OUT FROM THE SOUTH DURING THE OVERNIGHT HOURS.
THIS WOULD LEAD TO A TRANSITION TO A FREEZING RAIN/DRIZZLE SITUATION
UNTIL THE LOW LEVEL TEMPERATURES CAN WARM ON THURSDAY MORNING.
HEADING INTO THURSDAY...THE SURFACE TROUGH WILL SHIFT EAST ACROSS
THE CWA WHILE THE SURFACE LOW IS MOVING NORTHEAST INTO
SOUTHERN WISCONSIN BY THURSDAY EVENING. 12Z GFS REMAINS THE FASTEST
SOLUTION AND MOVING THE LOW NORTHEAST THROUGH NORTHWEST LOWER
MICHIGAN THURSDAY EVENING...WHILE THE NAM IS WAY TO THE NW. THE 12Z
GEM/ECMWF MEANWHILE ARE MUCH SLOWER AND TRACK THE LOW THROUGH THE
NORTHERN/CENTRAL OF LOWER MICHIGAN RESPECTIVELY LATE THURSDAY
NIGHT. WITH THE EXTREMELY WELL CLUSTERED 00Z ECMWF ENSEMBLE MEMBERS
ON THE LOW TRACK...HAVE A HARD TIME GOING MUCH AWAY FROM THAT IDEA
ALTHOUGH THE 12Z ECMWF WAS FARTHER SOUTHEAST. THUS...LIKE YESTERDAY
WILL FOLLOW THE SLOWER IDEA FOR TIMING AND THEN A BLEND OF THE
ECMWF/GFS/GEM FOR THE LOW TRACK.
AS FOR HOW THE PRECIPITATION WILL EVOLVE...EXPECT THERE TO BE SOME
WAA PRECIPITATION CONTINING INTO THE MORNING HOURS OVER THE EASTERN
CWA...BUT MODELS DO HINT AT THE DEEPER MOISTURE BEGINNING TO CUT
OUT OVER THE REST OF WESTERN/CENTRAL CWA AND WOULD EXPECT A
TRANSITION AWAY FROM SNOW AND TOWARDS A MIX OR RAIN/DRIZZLE. THAT
SIMILAR IDEA OF LIQUID PRECIP FOR THE MORNING SEEMS REASONABLE WITH
THE LACK OF DEEP MOISTURE AND MUCH OF THE CLOUD LAYER BELOW THE
FAVORED ICE CRYSTAL TEMPERATURES. SINCE THIS IDEA HAS BEEN SHOWN
OVER THE LAST DAY...TRANSITIONED THAT AREA TO MORE RAIN/DRIZZLE THAN
SNOW FOR THURSDAY MORNING. SURFACE TEMPERATURES WILL BE NEAR OR
SLIGHTLY BELOW FREEZING AT INITIALLY THURSDAY MORNING...SO THERE
COULD BE A FEW HOUR PERIOD OF FREEZING DRIZZLE...BUT WITH SOME
SNOW LIKELY OCCURRING EARLIER THE IMPACTS SHOULD BE LIMITED. FARTHER
WEST...WOULD EXPECT THERE TO BE A STRONG BAND OF PRECIPITATION
(MAINLY SNOW) ALONG THE WEST SIDE OF THE SURFACE TROUGH. THIS BAND
WILL BE OVER WESTERN LAKE SUPERIOR LATE WEDNESDAY NIGHT AND THEN
SHIFT EAST AND ONSHORE OVER THE FAR WEST ON THURSDAY MORNING. THIS
EASTWARD SHIFT WILL CONTINUE THROUGH THE AFTERNOON/EVENING HOURS
ACROSS THE REST OF THE CWA AND WOULD EXPECT SOME INTENSIFICATION OF
THE BAND DUE TO THE SHORTWAVE TROUGH EXPECTED TO PULL NORTHEAST WITH
THE SURFACE LOW AND INTO THE GREAT LAKES REGION. OUR CWA WILL BE ON
THE NORTHERN EDGE OF THAT WAVE...BUT THERE SHOULD STILL BE SOME
INFLUENCE. THEN AS THE LOW PULLS OUT OF LOWER MICHIGAN LATE THURSDAY
NIGHT AND FRIDAY MORNING...THE PRECIPITATION WILL FOLLOW SUIT AND
SHOULD BE MAINLY OUT OF THE CWA BY 12Z FRIDAY. THERE COULD BE SOME
LIGHT UPSLOPE SNOW UNDER THE NW WINDS ON FRIDAY OVER THE NW/NC U.P.
BUT WITH LITTLE HELP FROM LAKE ENHANCEMENT (MARGINAL 850MB TEMPS
AROUND -10C)...LITTLE OPEN WATER...AND DRY AIR MOVING IN FROM THE
APPROACHING HIGH WILL QUICKLY DIMINISH POPS FRIDAY MORNING.
NOW FOR PCPN AMOUNTS/TYPE. QPF AMOUNTS FOR THURSDAY INTO THURSDAY
NIGHT WILL LIKELY BE AROUND 0.33-0.66 (HEAVIEST EAST)...BUT THERE
COULD BE SOME LOCALIZED HIGHER AMOUNTS IN ANY BANDED LOCATIONS ALONG
THE SURFACE TROUGH. WITH DIFFERING IDEAS FROM THE MODELS ON HOW TO
HANDLE THE LOW-MID LEVEL WARMING...HAVE BEEN STRUGGLING WITH HOW
MUCH RAIN TO PUT IN THE FORECAST. GEM CONTINUES TO SHOW THE WARMEST
THERMAL PROFILE AND WOULD PUT RAIN OVER MUCH OF THE CWA. ECMWF/GFS
IN DECENT AGREEMENT THROUGH MUCH OF THURSDAY BEFORE THE FASTER GFS
QUICKLY PULLS COLD AIR INTO THE CWA. THE ECMWF SOLUTION WOULD KEEP
THE PRECIPITATION ASSOCIATED WITH THE FGEN/TROUGH AS MAINLY SNOW
AND THAT SEEMS REASONABLE WITH THE EXPECTED INTENSITY AS THAT
STRONGER BAND MOVES THROUGH. BEFORE THE TROUGH ARRIVES AND THE
EXPECTED LOSS OF DEEP MOISTURE...WILL HOLD ONTO SOME RAIN OVER
THE CENTRAL AND SHIFT IT EAST THROUGH THE DAY. OVER THE SOUTH
CENTRAL (MENOMINEE COUNTY)...THINK THEY WOULD HAVE BEST OPPORTUNITY
TO SEE AT LEAST HALF OF THE THURSDAY AFTERNOON PRECIP AS RAIN UNTIL
THE COLD AIR SURGES IN THURSDAY EVENING. THE P-TYPE MAKES THE
SNOWFALL FORECAST TRICKY...BUT THE GOING FORECAST HAS 1-4 INCHES
OVER MOST OF THE AREA AND SOME HIGHER AMOUNTS WHERE THE PRECIP WILL
BE ALL SNOW (KEWEENAW PENINSULA AND LUCE COUNTY). WILL CONTINUE TO
MENTION IN THE HWO...ALTHOUGH ADJUST THE WORDING TO HIGHLIGHT THE
FREEZING RAIN POTENTIAL LATE WEDNESDAY NIGHT INTO THURSDAY MORNING.
ALL IN ALL...IT APPEARS THAT IT WILL MAINLY BE AN ADVISORY TYPE
EVENT.
AS FOR THE REST OF THE FORECAST PERIOD...THE HIGH PRESSURE RIDGE
WILL LEAD TO CLEARING SKIES ON FRIDAY AFTERNOON/EVENING AND A QUIET
PERIOD OF WEATHER HEADING INTO SATURDAY. A TRANSITION TO MORE ZONAL
FLOW ON SATURDAY COULD SET THE STAGE FOR A BRIEF PERIOD OF PRECIP
ASSOCIATED WITH A SHORTWAVE MOVING EAST ALONG THE US/CANADIAN
BORDER ON SATURDAY NIGHT. BEST OPPORTUNITY WOULD BE OVER THE
NORTHERN HALF OF LAKE SUPERIOR AND WILL ONLY HAVE SLIGHT CHANCES
OVER THE NORTHERN PART OF THE CWA. WARM SOUTHWESTERLY FLOW AHEAD OF
A COLD FRONT THAT WILL MOVE THROUGH ON SUNDAY NIGHT WILL LEAD TO
NORMAL TO ABOVE NORMAL HIGHS ON SUNDAY. ECMWF/GEM CONTINUE TO
HANDLE HIGHS WELL THIS DAY (MID-UPPER 40S OVER THE WEST HALF OF
UPPER MICHIGAN)...WHILE THE GFS IS HEAVILY BIASED BY ITS SNOW COVER
KEEPING TEMPS DOWN. WILL CONTINUE TO FOCUS ON GEM/ECMWF TEMPS FOR
HIGHS.
AS THE COLD FRONT MOVES THROUGH ON SUNDAY NIGHT...SHOULD SEE SOME
PRECIPITATION ASSOCIATED WITH IT. THERMAL PROFILE WOULD SUPPORT
RAIN TRANSITIONING TO SNOW FROM WEST TO EAST THROUGH THE NIGHT AND
INTO MONDAY MORNING. MODELS DIFFER MORE ON THE EVOLUTION OF THE
UPPER TROUGH AND ASSOCIATED SURFACE LOW HEADING INTO MONDAY...WITH
THE 12Z ECMWF DIGGING IT MUCH FARTHER SOUTH (MID MISSISSIPPI
VALLEY) WHILE THE 12Z GFS HAS IT IN THE GREAT LAKES REGION. WILL
FOLLOW A GENERAL BLEND OF THE TWO FOR NOW. BEHIND THE WAVE...HIGH
PRESSURE WILL START TO MOVE IN ON TUESDAY AND TEMPERATURES WILL FALL
BACK TO BELOW NORMAL VALUES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1232 AM EDT WED MAR 26 2014
HIGH PRESSURE CONTINUES TO SLOWLY BUILD INTO THE CENTRAL U.S.
OVERNIGHT WITH SFC PRESSURE GRADIENT OVER UPPER MICHIGAN REMAINING
RELAXED THROUGH THE MORNING. ISOLATED FLURRIES CONTINUE TO LINGER
OVER THE REGION BUT WILL COME TO AN END AS DRIER AIR MOVES IN. AS
THE SFC HIGH PASSES TOT HE SOUTH OF THE REGION...RIDGE AXIS SLIDES
ACROSS THE U.P. OVERNIGHT AND WEDNESDAY MORNING WITH VFR CONDITIONS
PREVAILING THROUGH 0Z. APPROACHING LOW PRESSURE SYSTEM TO BRING IN
INCREASING CLOUDS...BUT EXPECT CIGS TO STAY ABOVE MVFR THROUGH THE
END OF THE FORECAST. ALL THREE TAF SITES TO SEE SOME LIGHT SNOW
DEVELOPING AFTER 0Z HOWEVER VSBYS TO REMAIN VFR THROUGH 6Z.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS ANOTHER HIGH
PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING
IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE
THROUGH THE GREAT LAKES REGION LATE THURSDAY NIGHT AND FRIDAY.
AHEAD OF THE LOW...SRLY WINDS WILL INCREASE TO 20 TO 25 KNOTS.
THEN...EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF THE LOW
THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON INTO
SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...RJT
MARINE...JLB
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
405 PM CDT Wed Mar 26 2014
.SHORT TERM: (Through Late Tonight)
Issued at 354 PM CDT Wed Mar 26 2014
Still expect that the leading edge of the showers currently over
northeast Oklahoma and southeast Kansas to continue to progress
northeastward into central Missouri early this evening, and then
move into northeast and east central Missouri by mid-late evening.
This goes along well with the latest runs of the RAP and our
localWRF which shows these showers being generated by 925-850mb
moisture convergence ahead of mid-level shortwave trough currently
western Oklahoma. These models show that this shortwave will
lift northeastward this evening and get sheared out as it lifts
through the CWA around 06Z, though low level moisture convergence
will be set up over the area through 12Z warranting high chance or
likely pops through the night.
The increase in clouds and the gradient winds staying up tonight
should keep temperatures from falling like they have the past few
nights. They may drop initially as the rain begins, but
temperatures are expected to remain above freezing with this event
because of the strong warm air advection. Went on the cooler side
of MOS for lows tonight given how low the dewpoints currently are.
Britt
.LONG TERM: (Thursday through Next Wednesday)
Issued at 354 PM CDT Wed Mar 26 2014
Ongoing showers and a few thunderstorms at daybreak on Thursday
should continue to lift northeast away from forecast area.
Otherwise, will see a break in activity til main frontal boundary
approaches region late Thursday afternoon over central MO. A few
storms may be severe late Thursday afternoon and evening with strong
low-mid level shear as a 500 mb wind max moves through the area.
The amount of instability is still in question and may be a limiting
factor for the amount and intensity of severe weather. As for high
temperatures, should be in the upper 50s to upper 60s since frontal
passage will be a bit slower than previously forecast.
Activity to taper off after midnight Thursday night as system exits
region. Not a lot of CAA behind this system, so lows will be in the
low 30s to mid 40s.
On Friday should see more precipitation develop as another shortwave
slides southeast through region on northwest flow and wave develops
along tail end of front that just moved through. So some overrunning
pcpn will develop south of forecast area and lift northeast into
forecast area by Friday evening, though best chances will be along
and south of I-70. As for precipitation type, it should be mostly in
the form of rain as colder air is slower to filter in. Could see
some rain mixed with snow after 06z Saturday for northern portions
of forecast area. Precipitation to exit region by daybreak Saturday.
Highs on Friday will be a bit cooler, in the low 50s to low 60s.
Lows Friday night will be in the low 30s far north to around 40 far
south.
On Saturday weak ridging builds in and skies clear out. Highs will
only be in the 50s.
Beyond that ridge moves off to the east on Sunday allowing warmer
weather to return. Highs on Sunday will be in the 60s. Then next in
a series of weather systems to approach the area late Sunday night
through Monday. Most of area has silent slight chance pops with low
chance pops along and east of Mississippi River on Monday. Highs on
Monday will be in the upper 50s to mid 60s. Then dry weather returns
to region Monday night through Tuesday before next system moves in.
This system is a bit stronger with better low level moisture. Rain
to begin moving in Tuesday night and persist through Wednesday.
Highs will be in the low 50s to low 60s Tuesday and Wednesday.
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 109 PM CDT Wed Mar 26 2014
Dry and VFR conditions are expected through 00Z. Then area of
showers currently over Oklahoma will move northeastward into
central Missouri, reaching KCOU around 02Z and the St. Louis metro
TAF sites and KUIN around 04Z. The airmass is currently very dry,
so expect VFR conditions through 08Z when visibilities lower to
MVFR. Around this same time, the low level jet will increase, so
have kept LLWS conditions. LLWS will wind down by mid morning as
south winds pick up and the low level jet weakens with mixing. Do
not expect as much MVFR ceilings tomorrow morning as precipitation
moves out of the area, but do expect additional showers and
thunderstorms to move through the TAF sites later Thursday
afternoon and evening.
Specifics for KSTL: Still looks like area of showers over central
Oklahoma will move into the terminal around 04Z. Expect showers to
continue into tomorrow morning with MVFR visibilities late tonight
and early Thursday. LLWS will develop late tonight as the low
level jet intensifies, but will then diminish by mid morning
Thursday as south winds increase and daytime mixing commences.
Expect mainly VFR ceilings on Thursday. Thunderstorms will develop
ahead of a surface cold front that will move through terminal on
Thursday evening. Scattered storms will be in the area as soon as
21Z on Thursday afternoon, so have included them in the TAF with
this issuance.
Britt
&&
.FIRE WEATHER:
Issued at Wed 404 PM CDT Wed Mar 26 2014
Will keep the Red Flag warning going until 7 pm as criteria is
being met or close to it in the warning area. By early this
evening, the winds will begin the decrease and RH will increase at
the same time that the rain currently entering southwest MO will
be approaching central MO.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...RED FLAG WARNING until 7 PM CDT this evening FOR Audrain MO-
Boone MO-Callaway MO-Cole MO-Gasconade MO-Knox MO-Lewis MO-
Lincoln MO-Marion MO-Moniteau MO-Monroe MO-Montgomery MO-
Osage MO-Pike MO-Ralls MO-Shelby MO-Warren MO.
IL...RED FLAG WARNING until 7 PM CDT this evening FOR Adams IL-Brown
IL-Calhoun IL-Greene IL-Jersey IL-Macoupin IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
311 PM CDT Wed Mar 26 2014
.SHORT TERM: (Through Late Tonight)
Issued at 304 PM CDT Wed Mar 26 2014
Still expect that the leading edge of the showers currently over
northeast Oklahoma and southeast Kansas to continue to progress
northeastward into central Missouri early this evening, and then
move into northeast and east central Missouri by mid-late evening.
This goes along well with the latest runs of the RAP and our
localWRF which shows these showers being generated by 925-850mb
moisture convergence ahead of mid-level shortwave trough currently
western Oklahoma. These models show that this shortwave will
lift northeastward this evening and get sheared out as it lifts
through the CWA around 06Z, though low level moisture convergence
will be set up over the area through 12Z warranting high chance or
likely pops through the night.
The increase in clouds and the gradient winds staying up tonight
should keep temperatures from falling like they have the past few
nights. They may drop initially as the rain begins, but
temperatures are expected to remain above freezing with this event
because of the strong warm air advection. Went on the cooler side
of MOS for lows tonight given how low the dewpoints currently are.
Britt
.LONG TERM: (Thursday through Next Wednesday)
Issued at 304 PM CDT Wed Mar 26 2014
Ongoing showers...with some isolated thunderstorms possible early
Thursday morning should continue to lift northeast away from
forecast area. Otherwise, will see a break in activity til main
frontal boundary approaches region late Thursday afternoon over
central MO. A few storms may be severe late Thursday afternoon and
evening with strong low-mid level shear as a 500 mb wind max moves
through the area. The amount of instability is still in question
and may be a limiting factor for the amount and intensity of
severe weather. As for high temperatures, should be in the upper
50s to upper 60s since frontal passage will be a bit slower than
previously forecast.
Activity to taper off after midnight Thursday night as system exits
region. Not a lot of CAA behind this system, so lows will be in the
low 30s to mid 40s.
On Friday should see more precipitation develop as another shortwave
slides southeast through region on northwest flow and wave develops
along tail end of front that just moved through. So some overrunning
pcpn will develop south of forecast area and lift northeast into
forecast area by Friday evening, though best chances will be along
and south of I-70. As for precipitation type, it should be mostly in
the form of rain as colder air is slower to filter in. Could see
some rain mixed with snow after 06z Saturday for northern portions
of forecast area. Precipitation to exit region by daybreak Saturday.
Highs on Friday will be a bit cooler, in the low 50s to low 60s.
Lows Friday night will be in the low 30s far north to around 40 far
south.
On Saturday weak ridging builds in and skies clear out. Highs will
only be in the 50s.
Beyond that ridge moves off to the east on Sunday allowing warmer
weather to return. Highs on Sunday will be in the 60s. Then next in
a series of weather systems to approach the area late Sunday night
through Monday. Most of area has silent slight chance pops with low
chance pops along and east of Mississippi River on Monday. Highs on
Monday will be in the upper 50s to mid 60s. Then dry weather returns
to region Monday night through Tuesday before next system moves in.
This system is a bit stronger with better low level moisture. Rain
to begin moving in Tuesday night and persist through Wednesday.
Highs will be in the low 50s to low 60s Tuesday and Wednesday.
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 109 PM CDT Wed Mar 26 2014
Dry and VFR conditions are expected through 00Z. Then area of
showers currently over Oklahoma will move northeastward into
central Missouri, reaching KCOU around 02Z and the St. Louis metro
TAF sites and KUIN around 04Z. The airmass is currently very dry,
so expect VFR conditions through 08Z when visibilities lower to
MVFR. Around this same time, the low level jet will increase, so
have kept LLWS conditions. LLWS will wind down by mid morning as
south winds pick up and the low level jet weakens with mixing. Do
not expect as much MVFR ceilings tomorrow morning as precipitation
moves out of the area, but do expect additional showers and
thunderstorms to move through the TAF sites later Thursday
afternoon and evening.
Specifics for KSTL: Still looks like area of showers over central
Oklahoma will move into the terminal around 04Z. Expect showers to
continue into tomorrow morning with MVFR visibilities late tonight
and early Thursday. LLWS will develop late tonight as the low
level jet intensifies, but will then diminish by mid morning
Thursday as south winds increase and daytime mixing commences.
Expect mainly VFR ceilings on Thursday. Thunderstorms will develop
ahead of a surface cold front that will move through terminal on
Thursday evening. Scattered storms will be in the area as soon as
21Z on Thursday afternoon, so have included them in the TAF with
this issuance.
Britt
&&
.FIRE WEATHER:
Issued at 1058 AM CDT Wed Mar 26 2014
Just a quick update to say that the Red Flag Warning still looks
on track. Southerly winds are increasing from the south late this
morning and will increase into criteria by this afternoon.
Likewise, minimum RH values are also expected to fall throughout
the area this afternoon.
Britt
Previous Discussion Issued at 240 AM CDT Wed Mar 26 2014
Critical fire conditions that will merit a Red Flag Warning are
expected to be met for mainly the afternoon hours for a good swath
of our region that will include northeast and central MO and curl
eastward to also include parts of west-central IL and southwest
IL--but should stop short of the Saint Louis Metro area. The 20ft
wind forecast is the primary driving factor of who to include and
not to include, as all areas are expected to drop to around 20%
for minimum RH values and 10hr fuel moisture criteria being met as
well.
The core of the strongest 20ft winds will be over in northeast and
central MO and areas westward but some of the critical winds will
likely take a bit longer into the afternoon to work their way
into parts of southwest IL.
Heightened fire weather conditions will be found for the remainder
of our area, including the Saint Louis metro area, much of
southeast and east-central MO and southern IL.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...RED FLAG WARNING until 7 PM CDT this evening FOR Audrain MO-
Boone MO-Callaway MO-Cole MO-Gasconade MO-Knox MO-Lewis MO-
Lincoln MO-Marion MO-Moniteau MO-Monroe MO-Montgomery MO-
Osage MO-Pike MO-Ralls MO-Shelby MO-Warren MO.
IL...RED FLAG WARNING until 7 PM CDT this evening FOR Adams IL-Brown
IL-Calhoun IL-Greene IL-Jersey IL-Macoupin IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BUFFALO NY
137 AM EDT WED MAR 26 2014
.SYNOPSIS...
COLDER AIR WILL BUILD IN BEHIND AN EXITING COLD FRONT OVERNIGHT...CAUSING
SOME LAKE EFFECT SNOW SHOWERS SOUTH AND SOUTHEAST OF THE LAKES.
WARMER AIR WILL ARRIVE TOWARDS THE END OF THE WEEK...ACCOMPANIED
BY INCREASING CHANCES FOR ADDITIONAL PRECIPITATION.
&&
.NEAR TERM /THROUGH TODAY/...
AT 1000 PM A COLD FRONT EXTENDS FROM ELMIRA TO FT DRUM...WITH THIS
FRONT POISED TO EXIT TO OUR EAST IN THE NEXT HOUR OR SO. THERE
HAVE ONLY BEEN SCATTERED SNOW SHOWERS ALONG THE FRONTAL BOUNDARY
ITSELF...WITH THE STEADIEST SNOW SHOWERS COMING BEHIND THE FRONT.
A LARGE PART OF THIS IS DUE TO LAKE ENHANCEMENT AS TEMPERATURES
ALOFT COOL RAPIDLY. THE 00Z BUFFALO SOUNDING IS POST-FRONTAL AND
SHOWS 850MB TEMPERATURES DOWN TO -12C...WITH COLDER AIR ON ITS HEELS.
LIGHT SNOW SHOULD MOVE EAST OF LAKE ONTARIO DURING THE NEXT COUPLE
HOURS...WHILE LAKE ENHANCED SNOW SHOWERS LINGER SOUTH OF LAKE
ONTARIO IN THE NW POST-FRONTAL FLOW. WITH THE AXIS OF THE UPPER TROF
UPSTREAM...EXPECT SOME LAKE ENHANCEMENT TO CONTINUE BEHIND THE
FRONT OVERNIGHT. THIS SHOULD BE MORE PRONOUNCED OFF LAKE
ONTARIO...BUT WITH SOME BREAKS IN THE ICE ON LAKE ERIE...SOME
LIGHT LAKE EFFECT SNOW OR FLURRIES IS POSSIBLE THERE TOO. IN TERMS
OF GUIDANCE...THE HRRR CONTINUES TO HAVE THE BEST HANDLE ON THE
PROGRESSION OF THE FRONT...BUT THE RGEM SHOULD HAVE A BETTER
HANDLE ON THE POST-FRONTAL LAKE ENHANCEMENT.
A COLD NW FLOW WILL CONTINUE MULTI BANDED LAKE EFFECT SNOW SOUTH
AND SOUTHEAST OF LAKE ONTARIO...WITH LIGHT STREAMERS ALSO LIKELY
COMING OFF LAKE ERIE AS WELL. THE STEADIEST SNOWS WILL COME LATE
TONIGHT AND INTO WEDNESDAY MORNING SOUTH AND SOUTHEAST OF LAKE
ONTARIO. IN GENERAL...THE MULTI BANDED STRUCTURE SHOULD PRODUCE
ONLY LIGHT ACCUMULATIONS IN THE INCH OR TWO RANGE. UPSLOPING OR
LOCALIZED BANDING MAY PRODUCE SLIGHTLY GREATER AMOUNTS...BUT THESE
WILL LIKELY FALL SHORT OF ADVISORY CRITERIA. OUTSIDE OF THESE LAKE
AREAS...AND ACROSS THE NORTH COUNTRY TOMORROW WILL LIKELY BE DRY
WITH LAKE EFFECT CLOUDS SLOWLY FADING TO SOME AFTERNOON SUNSHINE.
TEMPERATURES OVERNIGHT WILL DROP INTO THE SINGLE DIGITS IN A FEW
SPOTS...BUT LAKE CLOUDS SHOULD KEEP TEMPERATURES IN THE TEENS TO
AROUND 20 IN MOST AREAS. TOMORROW WILL BE COLD WITH AFTERNOON
HIGHS FORECAST TO BE JUST ABOVE RECORD LOW MAXES. HIGHS WILL RANGE
FROM THE UPPER TEENS TO MID 20S. EVEN IN A COLD AIRMASS THE HIGHER
LATE MARCH SUN ANGLE CAN STILL BRING SOME WARMTH TO THE SURFACE.
WILL SIDE SLIGHTLY ABOVE MODEL GUIDANCE FOR AFTERNOON HIGHS FOR
WEDNESDAY WHICH WILL STILL PLACE TEMPERATURES ABOUT 20 DEGREES
BELOW NORMAL. THE RECORD LOW MAXES FOR MARCH 26TH ARE AS FOLLOWS:
BUFFALO 23/1894...ROCHESTER 22/1923...WATERTOWN 27/1972.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
THE COLD AIR WILL PERSIST WEDNESDAY NIGHT. A NORTHWEST FLOW WILL KEEP
LAKE EFFECT SHOWERS LINGERING SOUTHEAST OF LAKE ONTARIO. THIS
ACTIVITY SHOULD BEGIN TO WIND DOWN TOWARD THURSDAY MORNING AS HIGH
PRESSURE SETTLES OVERHEAD. IT WILL BE ANOTHER VERY COLD NIGHT WITH
MOST LOW TEMPERATURES IN THE LOWER TEENS WITH SINGLE DIGITS LIKELY
ACROSS THE SOUTHERN TIER AND NORTH COUNTRY.
HIGH PRESSURE WILL SHIFT EAST OF THE AREA DURING THE DAY THURSDAY.
THIS WILL ALLOW SHORTWAVE ENERGY CURRENTLY OVER SOUTHERN CALIFORNIA
TO LIFT NORTHEAST TOWARD THE REGION. LOW LEVEL JET WILL RAMP UP
QUICKLY DURING THIS TIME...TO OVER 50 KNOTS BY LATE THURSDAY...
FORCING A SIGNIFICANT INCREASE IN ISENTROPIC ASCENT OVER A
RELATIVELY DEEP LAYER. TEMPERATURES WILL MODERATE CONSIDERABLY UNDER
INCREASING WARM AIR ADVECTION WHICH WILL PUSH TEMPERATURES WELL INTO
THE 40S...ALTHOUGH THEY MAY LINGER IN THE 30S ACROSS PORTIONS OF THE
NORTH COUNTRY.
INITIAL SURGE OF WARM AIR ADVECTION PRECIPITATION WILL LIKELY REMAIN
FOCUSED JUST TO OUR WEST THROUGH MUCH OF THE DAY THURSDAY...BUT BULK
OF THE LATEST 12Z GUIDANCE SUGGESTS THAT THE APPROACHING SHORTWAVE
MAY VERY WELL TOUCH OFF A FEW SHOWERS ACROSS WESTERN NEW YORK PRIOR
TO 00Z THURSDAY EVENING.
IT CONTINUES TO LOOKS LIKE THE BEST CHANCE FOR WIDESPREAD RAIN WILL
ARRIVE THURSDAY NIGHT AND CONTINUE THROUGH MUCH OF THE DAY FRIDAY AS
THE MAIN MID LEVEL TROUGH AXIS AND ASSOCIATED SURFACE LOW LIFT
THROUGH THE GREAT LAKES. THE EARLIER SEEN TIMING DIFFERENCES BETWEEN
DETERMINISTIC RUNS BEGINNING TO DECREASE WITH A COMPROMISE SOLUTION
SUGGESTING THE BEST CHANCE FOR THE STEADIEST RAINS BETWEEN 06Z AND
18Z FRIDAY.
THE RAINFALL...ABOUT A HALF INCH ON AVERAGE AND MILDER
TEMPERATURES...HIGHS AROUND 50 FRIDAY COULD POSE SOME ICE BREAKUP
AND ASSOCIATED FLOODING ISSUES. THESE TRENDS WILL NEED TO BE
MONITORED.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
FORECAST CONFIDENCE DECREASES SUBSTANTIALLY HEADING INTO THE WEEKEND
AS LAST PIECE OF PACIFIC ENERGY PUSHES THROUGH THE REGION. LATEST
12Z GFS ALONG WITH 00Z ECMWF...SUGGESTING ANOTHER ROUND OF SURFACE
CYCLOGENESIS ALONG THE OHIO VALLEY EARLY IN THE WEEKEND. 12Z
CANADIAN SHOWING THE SURFACE WAVE FARTHER TO THE NORTH. THIS WOULD
SPREAD A SHIELD OF STEADY PRECIPITATION INTO THE WESTERN AND
CENTRAL NEW YORK DURING SATURDAY. GFS THERMAL PROFILES EVEN SUGGEST
A PREDOMINATELY SNOW EVENT FOR NORTHERN AREAS WITH A CHANGE OVER TO
SNOW FOR THE SOUTHERN TIER. SIGNIFICANT RUN-TO-RUN INCONSISTENCY
REGARDING THIS SYSTEM LEADS TO LOW FORECAST CONFIDENCE THOUGH...AND
WILL HAVE TO GET A BETTER HANDLE ON EVOLUTION OF THE WAVE PUSHING
ACROSS THE REGION THURSDAY NIGHT AND FRIDAY BEFORE ANY HOPE OF
PINNING DOWN THE SATURDAY FORECAST.
CONDITIONS DO LOOK TO IMPROVE BEHIND THIS SYSTEM...AS HIGH PRESSURE
BUILDS IN FOR THE LATTER PART OF THE WEEKEND AND INTO EARLY NEXT
WEEK. MILDER PACIFIC AIR WILL FLOOD THE REGION DURING THIS TIME WITH
HIGHS SUNDAY IN THE 40S...AND INTO THE 50S MONDAY WITH SOME INTERIOR
SECTIONS PERHAPS TOPPING 60 DEGREES. NEXT PACIFIC SYSTEM MAY BRING
ADDITIONAL RAIN/SNOW CHANCES BY TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
IN THE WAKE OF AN ARCTIC COLD FRONT...SCATTERED TO NUMEROUS LAKE
EFFECT SNOW SHOWERS WILL DEVELOP SOUTHEAST OF LAKE ONTARIO THROUGH
THE BALANCE OF THE NIGHT...THEN WILL CONTINUE INTO THE EARLY TO
MID MORNING HOURS. THESE WILL PRODUCE RESTRICTIONS TO IFR/MVFR AT
TIMES...WITH LOW-END VFR CONDITIONS GENERALLY PREVAILING OUTSIDE
OF THE SNOW SHOWERS.
AFTER THAT TIME...INCREASING LATE MARCH DIURNAL INFLUENCES WILL
RESULT IN THE LAKE EFFECT SNOW SHOWERS WEAKENING AND BECOMING MORE
DISORGANIZED THROUGH THE REMAINDER OF THE DAY...WITH CIGS ALSO
GENERALLY LIFTING OVER TIME WITH DIURNAL MIXING. ALL OF THIS SHOULD
EVENTUALLY RESULT IN CONDITIONS IMPROVING TO VFR IN MOST AREAS.
TONIGHT...HIGH PRESSURE AND DRIER AIR WILL BUILD EASTWARD ACROSS NEW
YORK STATE AND BRING AN END TO ANY LINGERING LAKE EFFECT SNOW
SHOWERS OFF LAKE ONTARIO...WHILE ALSO HELPING TO SCATTER OUT ANY
LINGERING LOWER CIGS. OVERNIGHT...INCREASING WARM AIR ADVECTION
SETTING UP ALOFT WILL RESULT IN SOME INCREASE IN MID AND HIGH
CLOUDS...THOUGH OVERALL CONDITIONS WILL GENERALLY REMAIN VFR.
OUTLOOK...
THURSDAY...MAINLY VFR.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...MVFR/IFR WITH RAIN LIKELY
AND WINDY.
SATURDAY...MVFR WITH A CHANCE OF RAIN SHOWERS.
SUNDAY...MAINLY VFR.
&&
.MARINE...
A COLD FRONT AND SURFACE TROUGH WILL CROSS THE LOWER LAKES TONIGHT
AND COLDER AIR BEHIND THE COLD FRONT WILL POUR OVER THE EASTERN
GREAT LAKES. THIS COLDER...AND BLUSTERY AIRMASS WILL KICK UP WAVES
ON LAKE ONTARIO SUCH THAT SMALL CRAFT CONDITIONS WILL OCCUR AROUND
THE MIDNIGHT HOUR AND THROUGH THE DAY ON WEDNESDAY. HIGH PRESSURE
WILL RIDGE TOWARDS THE LOWER LAKES WEDNESDAY NIGHT AND THIS WILL
ALLOW FOR LIGHTER WINDS AND WAVES TO DROP BACK BELOW SMALL CRAFT
CONDITIONS ON LAKE ONTARIO.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT THURSDAY FOR LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
LOZ042.
&&
$$
SYNOPSIS...APFFEL/THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...APFFEL/JJR
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
337 PM CDT WED MAR 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 338 PM CDT WED MAR 26 2014
ALTHOUGH LOW LEVEL MOISTURE IS MORE LIMITED THAN EARLIER
THOUGHT...VISIBLE SATELLITE LOOPS SHOW CONVECTIVE LOOKING MID
LEVEL CLOUDS. RAP MID LEVEL LAPSE RATES ARE CLOSE TO ADIABATIC
AND BUFKIT SOUNDINGS SHOW 12K-15K FEET AGL SATURATION IN THE
DENDRITIC GROWTH ZONE. SO SHOULD SEE SOME FLAKE SHOWING UP AT THE
SURFACE EVENTUALLY. DID REDUCE THE CHANCE OF SNOW CONSIDERABLY
ACROSS THE WEST. LEFT THE BEST CHANCE AT LIKELY NORTH CENTRAL THIS
EVENING. THE BETTER CHANCE OF PRECIPITATION WILL TRANSITION TO
THE AREA SOUTH AND EAST OF THE JAMES RIVER VALLEY ON THURSDAY.
ON THURSDAY...A SURFACE HIGH WILL PUSH SOUTH INTO CENTRAL NORTH
DAKOTA. THE JAMES RIVER VALLEY WILL SEE INCREASED WINDS OF 20 TO
30 MPH THURSDAY AFTERNOON...BUT BELOW WIND ADVISORY CRITERIA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 338 PM CDT WED MAR 26 2014
THE MAIN FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD ARE A SERIES
OF STORMS SYSTEMS THAT WILL IMPACT THE NORTHERN PLAINS IN A MORE
ACTIVE...LESS AMPLIFIED PATTERN.
ON THURSDAY NIGHT AND FRIDAY...A COOL SURFACE HIGH OVER SOUTHERN
CANADA AND THE DAKOTAS WILL SLIDE SOUTHEAST AS A WEAK UPPER LEVEL
SHORTWAVE MOVES SOUTHEAST FROM MONTANA TO THE CENTRAL PLAINS. THIS
WILL INDUCE LOW PRESSURE OVER EASTERN MONTANA/WY/WESTERN DAKOTAS
THURSDAY NIGHT WHICH WILL ALSO MOVE/DEVELOP SOUTHEAST ON FRIDAY.
LIGHT RAIN/SNOW IS POSSIBLE ACROSS THE WESTERN HALF OF THE STATE
THURSDAY NIGHT...AND OVER ALL OF WESTERN AND CENTRAL NORTH DAKOTA ON
FRIDAY. CONTINUED COOL THIS PERIOD WITH LOWS THURSDAY NIGHT FROM
ZERO TO 20 ABOVE...AND HIGHS FRIDAY FROM THE 20S TO NEAR 40.
FRIDAY NIGHT AND SATURDAY...A WARM-UP BEGINS WITH A LOW PRESSURE
SYSTEM EXPECTED TO DEVELOP OVER THE ROCKIES OF SOUTHERN
ALBERTA/MONTANA. THIS WILL INDUCE SOUTHERLY WINDS ACROSS THE REGION.
AFTER LOWS FRIDAY NIGHT IN THE TEENS NORTH CENTRAL TO 20S
ELSEWHERE...EXPECT A NICE WARM-UP SATURDAY WITH HIGHS REACHING THE
40S IN THE TURTLE MOUNTAINS TO THE UPPER 50S SOUTH AND WEST OF THE
MISSOURI RIVER.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE LOW PRESSURE SYSTEM THAT
WILL BRING THE SATURDAY WARM-UP WILL DEEPEN AND BEGIN TO
MOVE/DEVELOP OVER WYOMING/SOUTH DAKOTA AS A SIGNIFICANT LONGWAVE
TROUGH MOVES EAST ACROSS THE ROCKIES. THIS SYSTEM WILL INTENSIFY AS
IT CONTINUES EASTWARD INTO IOWA/MINNESOTA BY DAYBREAK MONDAY. THIS
SYSTEM WILL BRING A LARGE AREA OF RAIN AND SNOW TO THE CENTRAL AND
NORTHERN PLAINS. EXPECT CHANCES OF RAIN SATURDAY NIGHT...CHANGING TO
SNOW SUNDAY MORNING...THEN BACK TO RAIN ACROSS THE SOUTH SUNDAY
AFTERNOON...BEFORE BACK TO ALL SNOW SUNDAY NIGHT. THIS SCENARIO
WOULD RESULT IN A COUPLE OF INCHES OF SNOW IN THE NORTH
CENTRAL...WITH MORE RAIN THAN SNOW SOUTH. LOWS SATURDAY NIGHT SHOULD
BE IN THE 20S TO LOWER 30S...WITH HIGHS SUNDAY RANGING FROM 30 NORTH
TO THE 40S SOUTH.
THE NEXT SYSTEM TO AFFECT THE AREA DEVELOPS IN THE ROCKIES NEAR
COLORADO MONDAY NIGHT/TUESDAY AND EMERGES INTO THE PLAINS
TUESDAY/TUESDAY NIGHT AND DEVELOPING IN THE MISSISSIPPI AND OHIO
VALLEYS WEDNESDAY NIGHT. THIS SYSTEM HAS THE POTENTIAL FOR RAIN AND
SNOW ACROSS THE NORTHERN PLAINS...BUT MUCH UNCERTAINTY REMAINS WITH
THE EVOLUTION OF THIS SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 338 PM CDT WED MAR 26 2014
SURFACE TROUGH ACROSS EASTERN MONTANA WILL MOVE ACROSS NORTH
DAKOTA TONIGHT. EXPECT LIGHT RAIN AND SNOW FROM KDIK-KMOT WITH
GENERALLY VFR CONDITIONS THROUGH 00Z. AFTER 00Z MVFR CONDITIONS
LIKELY TO SPREAD SOUTH FROM KMOT INTO KBIS AND KJMS AFTER 05Z.
GUSTY NORTHWEST WINDS 15 TO 25 KTS DEVELOPING AT KJMS AFTER 15Z
THURSDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WAA
LONG TERM...JV
AVIATION...WAA
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
121 PM CDT WED MAR 26 2014
.UPDATE...
18Z AVIATION DISCUSSION UPDATED BELOW.
BASED ON LATEST RAP 925MB TEMPS ACROSS THE SOUTHWEST CWA FOR LATER
THIS AFTERNOON...HAVE INCREASED HIGHS A COUPLE DEGREES. WILL SEE A
MILD DAY ACROSS THE CWA WITH TEMPS GENERALLY IN THE 50S AND
60S...WITH READINGS AROUND 70 ALONG AND SOUTH OF I-90. BREEZY
SOUTHERLY WINDS WILL BE FELT ACROSS THE EASTERN CWA...BUT IT STILL
APPEARS THERE WILL BE NO NEED FOR A WIND ADVISORY AS THE STRONGEST
WINDS LOOK TO SET UP OVER SOUTHEAST SD INTO PORTIONS OF SOUTHERN
MN AND NORTHWEST IA.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
PRESSURE RISES AND INCREASING SOUTHEASTERLY WINDS HAVE ALLOWED
TEMPERATURES TO LEVEL OR EVEN SLOWLY RISE THROUGH THE NIGHT AND
INTO THIS MORNING.
WINDS WILL BE STRONG AND GUSTY ACROSS THE EASTERN CWA THIS
AFTERNOON...PERHAPS EVEN HITTING MARGINAL WIND ADVISORY CRITERIA.
HOWEVER...GIVEN A WARM AIR ADVECTION PATTERN...NOT CONVINCED THAT
CRITERIA WILL BE MET...OR IF IT IS IT WILL BE A VERY SHORT PERIOD
OF TIME. MODELS SHOW THE SURFACE LOW MOVING OUT OF SOUTHEAST
MONTANA/NORTHEAST WYOMING...TOWARD THE TRIPLE POINT OF
WYOMING/SOUTH DAKOTA/NEBRASKA...AND THEN SOUTHEAST ACROSS NEBRASKA
AND SOUTHERN SOUTH DAKOTA BEFORE LIFTING INTO IOWA AND EVENTUALLY
INTO THE GREAT LAKES REGION. THIS TRACK LIFTS A WARM FRONT
NORTHWARD ACROSS OUR CWA THIS AFTERNOON. WHILE WARMER TEMPERATURES
ARE EXPECTED FOR THIS AFTERNOON /HIGHS IN THE 50S AND 60S/ THIS
AIR MASS IS ALSO QUITE DRY...WITH MODEL SURFACE TEMP/DEWPOINT
SPREADS RANGING FROM 20 TO 30 DEGREES ACROSS MOST OF THE CWA THIS
AFTERNOON. COMBINED WITH GUSTY WINDS...THIS DOES PUSH THE SOUTHERN
AND EASTERN CWA INTO THE HIGH FIRE DANGER CATEGORY. THE DRY AIR
WILL ALSO SEVERELY LIMIT PRECIPITATION DEVELOPMENT INITIALLY.
MODELS DO SHOW SATURATION ALONG THE COLD FRONT LATER THIS EVENING
AND OVERNIGHT ACROSS THE EASTERN CWA. MODERATE FRONTOGENESIS AND
STEEP LAPSE RATES WILL LIKELY COUPLE RESULTING IN A BAND OF RAIN
OR SNOWFALL...BUT MOST LIKELY EAST OF THIS CWA. SO WHILE THE BEST
CHANCES FOR PRECIPITATION ARE CURRENTLY FORECAST FOR THIS TIME
PERIOD ACROSS THE EASTERN CWA...SNOWFALL AMOUNTS AT THIS POINT
WERE LEFT AROUND A HALF INCH OR LESS.
GUSTY NORTHERLY WINDS ARE AGAIN EXPECTED ACROSS MUCH OF THE REGION
GOING INTO THURSDAY AS THE PRESSURE GRADIENT TIGHTENS UP BETWEEN
THE EXITING LOW AND HIGH PRESSURE DROPPING OUT OF CANADA. WEAK
COLD AIR ADVECTION ENSURES BELOW NORMAL TEMPERATURES AGAIN FOR
THURSDAY AND FRIDAY. ALSO...ADDITIONAL PRECIPITATION CHANCES ARE
POSSIBLE ACROSS THE SOUTHWEST CWA FRIDAY DUE TO SHORTWAVE ENERGY
AND A MID LEVEL BAROCLINIC ZONE SETTING UP ACROSS SOUTHWEST SOUTH
DAKOTA.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
HIGH PRESSURE WILL EXIT THE AREA TO THE EAST FRIDAY NIGHT AHEAD OF
AN APPROACHING LOW PRESSURE SYSTEM. FAIRLY STRONG WAA BETWEEN
THESE TWO SYSTEMS WILL RESULT IN ABOVE NORMAL TEMPERATURES BOTH
SATURDAY AND SUNDAY. THE LOW CENTER TRACKS ACROSS SOUTHERN SOUTH
DAKOTA DURING THE DAY SUNDAY...AND THERE IS DECENT CONSENSUS
BETWEEN THE MODELS ON THIS...WHICH IS A FURTHER NORTH SOLUTION AS
COMPARED TO THE PREVIOUS MODEL RUNS. DIFFERENCES SHOW UP SUNDAY
NIGHT AS TO THE LOCATION AND AMOUNT OF PRECIPITATION ON THE BACK
SIDE OF THE LOW. FOR THE TIME BEING...WILL STICK CLOSE TO ALLBLEND
POPS...WHICH ARE MAINLY IN THE SCHC/CHC CATEGORY BRINGING SOME
RAIN IN SUNDAY...WITH A POSSIBLE SWITCH OVER TO SNOW SUNDAY NIGHT
AND COLDER AIR GETS PULLED SOUTHWARD ON THE BACK SIDE OF THE
EXITING LOW. HIGH PRESSURE THEN DROPS BACK OVER THE REGION AND
REMAINS DOMINANT THROUGH EARLY TUESDAY. ANOTHER LOW PRESSURE
SYSTEM THEN APPROACHES FROM THE WEST...AND LOOKS TO BRING
PRECIPITATION AND GUSTY WINDS TO THE AREA TUESDAY AFTERNOON AND
TUESDAY NIGHT. WILL ALSO SEE A RETURN TO BELOW NORMAL TEMPERATURES
MONDAY AND TUESDAY.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
AN UPPER LEVEL LOW PRESSURE TROUGH OUT WEST WILL MOVE INTO THE
REGION TONIGHT AND THURSDAY AND INTENSIFY. A COLD FRONT WILL ALSO
BE SINKING SOUTH ACROSS THE REGION THROUGH THE NIGHT BRINGING
WINDS AROUND TO THE NORTH. AS THE SURFACE PRESSURE GRADIENT
TIGHTENS UP AND CAA MIXING STRONG WINDS OFF THE SURFACE COME
DOWN...EXPECT IT TO BECOME WINDY AT ALL LOCATIONS TONIGHT AND
THURSDAY. THESE NORTH WINDS ALONG WITH THE DEVELOPING SYSTEM WILL
ALSO BRING IN MVFR STRATUS CLOUDS TO ALL LOCATIONS. THE OTHER
IMPORTANT ISSUE WILL BE THE DEVELOPMENT OFF A DEFORMATION
ZONE/FRONTOGENETICAL BAND OF SNOW LATER TONIGHT AND THURSDAY
MORNING. THE MODELS DIFFER ON THE EXACT LOCATION OF THIS IN OUR
EASTERN AREA. THUS...AT THIS TIME JUST INSERTED SOME LIGHT SNOW IN
AT ATY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...SERR
LONG TERM...PARKIN
AVIATION...MOHR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1102 AM CDT WED MAR 26 2014
.UPDATE...REST OF TODAY
BASED ON LATEST RAP 925MB TEMPS ACROSS THE SOUTHWEST CWA FOR LATER
THIS AFTERNOON...HAVE INCREASED HIGHS A COUPLE DEGREES. WILL SEE A
MILD DAY ACROSS THE CWA WITH TEMPS GENERALLY IN THE 50S AND
60S...WITH READINGS AROUND 70 ALONG AND SOUTH OF I-90. BREEZY
SOUTHERLY WINDS WILL BE FELT ACROSS THE EASTERN CWA...BUT IT STILL
APPEARS THERE WILL BE NO NEED FOR A WIND ADVISORY AS THE STRONGEST
WINDS LOOK TO SET UP OVER SOUTHEAST SD INTO PORTIONS OF SOUTHERN
MN AND NORTHWEST IA.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
PRESSURE RISES AND INCREASING SOUTHEASTERLY WINDS HAVE ALLOWED
TEMPERATURES TO LEVEL OR EVEN SLOWLY RISE THROUGH THE NIGHT AND
INTO THIS MORNING.
WINDS WILL BE STRONG AND GUSTY ACROSS THE EASTERN CWA THIS
AFTERNOON...PERHAPS EVEN HITTING MARGINAL WIND ADVISORY CRITERIA.
HOWEVER...GIVEN A WARM AIR ADVECTION PATTERN...NOT CONVINCED THAT
CRITERIA WILL BE MET...OR IF IT IS IT WILL BE A VERY SHORT PERIOD
OF TIME. MODELS SHOW THE SURFACE LOW MOVING OUT OF SOUTHEAST
MONTANA/NORTHEAST WYOMING...TOWARD THE TRIPLE POINT OF
WYOMING/SOUTH DAKOTA/NEBRASKA...AND THEN SOUTHEAST ACROSS NEBRASKA
AND SOUTHERN SOUTH DAKOTA BEFORE LIFTING INTO IOWA AND EVENTUALLY
INTO THE GREAT LAKES REGION. THIS TRACK LIFTS A WARM FRONT
NORTHWARD ACROSS OUR CWA THIS AFTERNOON. WHILE WARMER TEMPERATURES
ARE EXPECTED FOR THIS AFTERNOON /HIGHS IN THE 50S AND 60S/ THIS
AIR MASS IS ALSO QUITE DRY...WITH MODEL SURFACE TEMP/DEWPOINT
SPREADS RANGING FROM 20 TO 30 DEGREES ACROSS MOST OF THE CWA THIS
AFTERNOON. COMBINED WITH GUSTY WINDS...THIS DOES PUSH THE SOUTHERN
AND EASTERN CWA INTO THE HIGH FIRE DANGER CATEGORY. THE DRY AIR
WILL ALSO SEVERELY LIMIT PRECIPITATION DEVELOPMENT INITIALLY.
MODELS DO SHOW SATURATION ALONG THE COLD FRONT LATER THIS EVENING
AND OVERNIGHT ACROSS THE EASTERN CWA. MODERATE FRONTOGENESIS AND
STEEP LAPSE RATES WILL LIKELY COUPLE RESULTING IN A BAND OF RAIN
OR SNOWFALL...BUT MOST LIKELY EAST OF THIS CWA. SO WHILE THE BEST
CHANCES FOR PRECIPITATION ARE CURRENTLY FORECAST FOR THIS TIME
PERIOD ACROSS THE EASTERN CWA...SNOWFALL AMOUNTS AT THIS POINT
WERE LEFT AROUND A HALF INCH OR LESS.
GUSTY NORTHERLY WINDS ARE AGAIN EXPECTED ACROSS MUCH OF THE REGION
GOING INTO THURSDAY AS THE PRESSURE GRADIENT TIGHTENS UP BETWEEN
THE EXITING LOW AND HIGH PRESSURE DROPPING OUT OF CANADA. WEAK
COLD AIR ADVECTION ENSURES BELOW NORMAL TEMPERATURES AGAIN FOR
THURSDAY AND FRIDAY. ALSO...ADDITIONAL PRECIPITATION CHANCES ARE
POSSIBLE ACROSS THE SOUTHWEST CWA FRIDAY DUE TO SHORTWAVE ENERGY
AND A MID LEVEL BAROCLINIC ZONE SETTING UP ACROSS SOUTHWEST SOUTH
DAKOTA.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
HIGH PRESSURE WILL EXIT THE AREA TO THE EAST FRIDAY NIGHT AHEAD OF
AN APPROACHING LOW PRESSURE SYSTEM. FAIRLY STRONG WAA BETWEEN
THESE TWO SYSTEMS WILL RESULT IN ABOVE NORMAL TEMPERATURES BOTH
SATURDAY AND SUNDAY. THE LOW CENTER TRACKS ACROSS SOUTHERN SOUTH
DAKOTA DURING THE DAY SUNDAY...AND THERE IS DECENT CONSENSUS
BETWEEN THE MODELS ON THIS...WHICH IS A FURTHER NORTH SOLUTION AS
COMPARED TO THE PREVIOUS MODEL RUNS. DIFFERENCES SHOW UP SUNDAY
NIGHT AS TO THE LOCATION AND AMOUNT OF PRECIPITATION ON THE BACK
SIDE OF THE LOW. FOR THE TIME BEING...WILL STICK CLOSE TO ALLBLEND
POPS...WHICH ARE MAINLY IN THE SCHC/CHC CATEGORY BRINGING SOME
RAIN IN SUNDAY...WITH A POSSIBLE SWITCH OVER TO SNOW SUNDAY NIGHT
AND COLDER AIR GETS PULLED SOUTHWARD ON THE BACK SIDE OF THE
EXITING LOW. HIGH PRESSURE THEN DROPS BACK OVER THE REGION AND
REMAINS DOMINANT THROUGH EARLY TUESDAY. ANOTHER LOW PRESSURE
SYSTEM THEN APPROACHES FROM THE WEST...AND LOOKS TO BRING
PRECIPITATION AND GUSTY WINDS TO THE AREA TUESDAY AFTERNOON AND
TUESDAY NIGHT. WILL ALSO SEE A RETURN TO BELOW NORMAL TEMPERATURES
MONDAY AND TUESDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY AND INTO THIS
EVENING. LOOK FOR MVFR CIGS TO OVERSPREAD THE AREA AFTER 06Z.
LIGHT SNOW MAY REDUCE VSBYS INTO THE MVFR CATEGORY ACROSS THE FAR
EASTERN CWA...INCLUDING KATY...LATE TONIGHT AS WELL.
SOUTHERLY WINDS WILL INCREASE INTO THE 15 TO 30 KNOT RANGE BY MID
MORNING. LOOK FOR SOME DIMINISHMENT IN THE WINDS DURING THE
EVENING...THEN WINDS WILL SHIFT TO A NORTH/NORTHWESTERLY DIRECTION
AND WILL INCREASE INTO THE 20 TO 35 KNOT RANGE DURING THE
OVERNIGHT HOURS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TMT
SHORT TERM...SERR
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1045 PM CDT THU MAR 27 2014
.UPDATE...
RAN A QUICK UPDATE TO INCREASE POPS FOR THUNDERSTORM CHANCES
ACROSS THE CWA TOMORROW.
WATER VAPOR SATELLITE IMAGERY WAS TRACKING A COMPACT SHORTWAVE
TROUGH OVER SOUTHERN CALIFORNIA...MOVING EAST TOWARDS ARIZONA AND
NEW MEXICO. THIS TROUGH IS EXPECTED TO SPREAD LARGE SCALE FORCING
FOR ASCENT OVER NORTH TX STARTING AROUND 18Z. CONVECTION THIS
EVENING ACROSS THE CWA WAS LIMITED TO COLLIN COUNTY AND AREAS
NORTHEAST...SO ANY REMNANT OUTFLOW BOUNDARIES ARE EXPECTED TO
REMAIN IN PLACE ACROSS THE NORTHEASTERN CWA...IF THEY DONT JUST
DISSIPATE ALL TOGETHER BY TOMORROW MORNING. THE DRYLINE MADE IT
AS FAR EAST AS A GAINESVILLE TO FORT WORTH TO HAMILTON LINE THIS
AFTERNOON...AND WAS OBSERVED TO BE RETREATING BACK TO THE WEST AT
THE TIME OF THIS DISCUSSION. A COLD FRONT WAS OBSERVED ACROSS EAST
CENTRAL OKLAHOMA...STRETCHING BACK WEST TO THE TEXAS PANHANDLE.
THIS BOUNDARY WAS MOVING SLOWLY SOUTH THIS EVENING...AT AROUND 10
MPH.
THE 00Z NAM AND RAP MODELS WERE CONSISTENT IN SHOWING A LOW-LEVEL
(850 MB) THETA-E RIDGE MOVING NORTHEAST ACROSS THE CWA FROM AROUND
THE MILLS/LAMPASAS COUNTY AREA TOMORROW MORNING. THIS THETA-E
RIDGE WAS MORE OR LESS CONSISTENT WITH THE ZONE OF BEST Q-VECTOR
CONVERGENCE OR POSITIVE PRESSURE ADVECTION ON THE 1.5 PVU SURFACE.
AS A RESULT...THINK THAT THE THETA-E RIDGE IS LIKELY TO BE REAL
AND ASSOCIATED WITH LARGE SCALE FORCING FOR ASCENT BROUGHT ON BY
THE APPROACHING SHORTWAVE TROUGH. THIS THETA-E RIDGE IS EXPECTED
TO EXPAND IN AREAL COVERAGE WHILE MOVING NORTHEAST ACROSS THE
SOUTHEASTERN HALF OF THE CWA TOMORROW MORNING. NON-CONVECTION
ALLOWING OPERATIONAL GUIDANCE CONSISTENTLY HAS ITS CONVECTIVE
PARAMETERIZATION SCHEMES TRIGGERED IN THIS ZONE OF RICH THETA-E
AIR...SO CONFIDENCE IN A MORNING ROUND OF LARGELY UNORGANIZED
THUNDERSTORM ACTIVITY HAS INCREASED. WENT AHEAD AND BUMPED UP POPS
TO 30 PERCENT FOR LOCATIONS ALONG AND SOUTH OF A LAMPASAS TO
HILLSBORO TO PALESTINE LINE TOMORROW MORNING AS A RESULT. SEVERE
WEATHER IS POSSIBLE WITH THIS ACTIVITY...BUT SHOULD REMAIN
ELEVATED IN NATURE LEAVING ONLY A MARGINAL HAIL THREAT DURING THE
MORNING HOURS OF THE DAY.
FOR THE AFTERNOON...THE MORNING CONVECTION...DEPENDING ON HOW
STRONG IT IS...AND HOW LARGE ITS AREAL COVERAGE IS...MAY IMPEDE
AFTERNOON THUNDERSTORM INITIATION. AFTERNOON THUNDERSTORM
INITIATION IS MOST LIKELY ALONG THE DRYLINE...AND THEN AGAIN ALONG
THE COLD FRONT. INITIATION IS DEPENDENT UPON GOOD SOLAR INSOLATION
REMOVING A LOW-LEVEL INVERSION AND MIXING OUT LOW-LEVEL MORNING
STRATUS...ALLOWING FOR SURFACE BASED STORMS. MESOSCALE FORCING FOR
ASCENT ASSOCIATED WITH THE COLD FRONT AND DRYLINE WILL CERTAINLY
SUPPORT STRONG LIFT NEAR THESE BOUNDARIES...HOWEVER FORECAST
SOUNDINGS INDICATE TOO MUCH CONVECTIVE INHIBITION TO BE OVERCOME
BY LIFT ALONE. ASSUMING MORNING CONVECTION EITHER DOES NOT PAN
OUT...OR THAT THE CLOUDS CLEAR OUT SUFFICIENTLY TO ALLOW FOR A FEW
HOURS OF HEATING...THUNDERSTORM INITIATION ALONG THESE BOUNDARIES
CAN BE EXPECTED TO OCCUR AROUND 21Z OR 4 PM CDT.
AT 21Z...THE DRYLINE IS EXPECTED TO BE LOCATED JUST WEST OF THE
INTERSTATE 35 CORRIDOR WITH THE COLD FRONT DROPPING SOUTH TO A
SHERMAN TO FORT WORTH TO CISCO LINE. THIS LEAVES THE TRIPLE POINT
NEAR THE DFW AREA...WHERE THE STRONGEST MESOSCALE FORCING FOR
ASCENT SHOULD OCCUR. WENT AHEAD AND BUMPED POPS UP TO 30 PERCENT
NEAR THESE BOUNDARIES...INCREASING TO 50 PERCENT TO THE EAST AND
SOUTHEAST. WITH THE FAST MOVING NATURE OF THE SHORTWAVE TROUGH AND
ITS ENHANCED MID-UPPER LEVEL WIND SPEEDS...ANY INITIATED STORMS
WOULD TEND TO PULL AWAY FROM THESE BOUNDARIES SOMEWHAT QUICKLY.
HIGH RESOLUTION MODELS INDICATE THE POTENTIAL FOR AROUND 2000 J/KG
OF SURFACE BASED CAPE WITH A DEEP LAYER BULK SHEAR MAGNITUDE OF
AROUND 50 KTS...A BASIC PARAMETER SPACE OVERLAP FAVORING AN
ORGANIZED STORM MODE WITH SUPERCELLS...OR CLUSTERS OF STORMS WITH
EMBEDDED SUPERCELL STRUCTURES.
WHETHER THIS MUCH CAPE CAN BE REALIZED OR NOT DEPENDS LARGELY ON
THE FACTORS DISCUSSED ABOVE...AND WILL BE LARGELY UNKNOWN UNTIL WE
SEE HOW MUCH PRECIPITATION EXISTS TOMORROW MORNING. IF THE CAPE IS
REALIZED...THE PRIMARY SEVERE WEATHER HAZARDS SHOULD BE LARGE HAIL
AND DAMAGING WINDS. A CONDITIONAL TORNADO THREAT IS DEPENDENT UPON
INDIVIDUAL STORMS INTERACTING WITH ANY REMNANT BOUNDARIES TOMORROW
AFTERNOON. OVERALL THE TORNADO THREAT DOES NOT LOOK HIGH FROM THE
SYNOPTIC ENVIRONMENT...BUT WE WILL SEE HOW EVERYTHING EVOLVES
AFTER TOMORROW MORNING. THE THREAT FOR TORNADOES LOOKS LOW FOR NOW
AT LEAST. STORMS SHOULD MOVE EAST OF THE CWA QUICKLY AFTER SUNSET
AS THE SHORTWAVE TROUGH PUSHES EAST...AND THE COLD FRONT BEGINS TO
MOVE QUICKLY ACROSS THE CWA.
CAVANAUGH
&&
.AVIATION...
/00Z TAFS/
CONCERNS...RETURN OF IFR CIGS OVERNIGHT AND POTENTIAL FOR THUNDER
FRIDAY AFTERNOON.
WIND SPEEDS WILL FINALLY DIMINISH WITHIN AN HOUR AND DROP BELOW 10
KTS THIS EVENING. TWO DRYLINES CURRENTLY BISECT TARRANT COUNTY
WITH SOUTHWEST WINDS AT KFTW AND NORTHWEST WINDS AT KAFW. EXPECT
THE WINDS AT THESE TWO SITES TO RETURN TO A SOUTH DIRECTION THIS
EVENING AS THE DRYLINES RETREAT BACK TO THE WEST. THERE IS SOME
DISCREPANCY AMONG IF MVFR/IFR CIGS WILL RETURN TO THE I-35
CORRIDOR OVERNIGHT. WITH THE DRYLINE REMAINING WEST OF THE TAF
SITES...WILL CONTINUE TO MENTION LOW CIGS RETURNING TO THE
AIRPORTS BUT WILL PUSH THE RETURN TIME BACK TO AROUND 09Z. WITH
LIGHT WINDS EXPECTED OVERNIGHT AND A VERY HUMID ATMOSPHERE STILL
IN PLACE...IFR CIGS ARE LIKELY WITH BASES BETWEEN 400-1000 FEET.
AREAS OF FOG WILL LIKELY DEVELOP WITH 3-5SM BR. CEILINGS WILL
START TO LIFT LATE FRIDAY MORNING WITH VFR CONDITIONS DURING THE
AFTERNOON HOURS.
A STRONG SHORTWAVE CURRENTLY OVER SOUTHERN CALIFORNIA WILL BE
CROSSING THE REGION FRIDAY AFTERNOON AND FORECAST SOUNDINGS
INDICATE AN UNSTABLE AND LIKELY UNCAPPED ATMOSPHERE WITH DECENT
LAPSE RATES ALOFT. THIS SUPPORTS A THUNDER THREAT DURING THE
AFTERNOON HOURS AS THE SHORTWAVE PROVIDES SUFFICIENT LIFT. SEVERE
STORMS CANNOT BE RULED OUT AT THE AIRPORTS WITH A THREAT FOR HAIL
AND DAMAGING WINDS. A COLD FRONT WILL MOVE THROUGH THE METROPLEX
TAF SITES AROUND 22Z AND KACT CLOSER TO 00Z. THUNDERSTORMS WILL
CONTINUE TO BE A THREAT IN THE METROPLEX THROUGH 00Z...EVEN BEHIND
THE FRONT. NORTHWEST TO NORTH WINDS WILL OCCUR BEHIND THE FRONT.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 311 PM CDT THU MAR 27 2014/
AN UPPER LEVEL TROUGH CAN BE SEEN ON THE LATEST WATER VAPOR LOOP
LIFTING NORTHEAST FROM THE CENTRAL PLAINS TOWARDS THE GREAT LAKES.
A DEEP SURFACE CYCLONE IS FOLLOWING ALONG A SIMILAR PATH BENEATH
THE UPPER TROUGH...AND THE RESULTING FLOW IS SENDING A COLD FRONT
SOUTHWARD TOWARDS NORTH TEXAS. BOTH THE FRONT AND FORCING FOR
ASCENT ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL REMAIN WELL
NORTH OF NORTH TEXAS THIS EVENING. ANY SURFACE FOCUS FOR
CONVECTION WILL BE ASSOCIATED WITH A DRYLINE...WHICH WAS
ENCROACHING ON THE I-35 CORRIDOR THIS AFTERNOON. ISOLATED
THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH SUNSET THIS EVENING
ALONG THE DRYLINE...WITH THE BETTER CHANCES FOR CONVECTION WELL
EAST OF THE DRYLINE WHERE MOISTURE LEVELS ARE HIGHER AND WEAK
ASCENT FROM THE SOUTHERN EXTENT OF THE PLAINS SYSTEM WILL RESIDE.
THOUGH COVERAGE WILL BE LOW DUE TO VEERING SURFACE WINDS AND A
LINGERING CAP OVERHEAD...CAPE OF 1500 TO 2000 J/KG ENSURES THAT
ANY STORMS THAT DEVELOP COULD BECOME STRONG TO POSSIBLY SEVERE
WITH HAIL AND DAMAGING WINDS. WEST OF THE DRYLINE...HIGH FIRE
DANGER WILL CONTINUE FOR A FEW MORE HOURS BEFORE TEMPERATURES FALL
AND WINDS DECREASE AFTER SUNSET.
THE FRONT WILL CROSS THE RED RIVER TONIGHT AND SAG SLOWLY SOUTH
TO NEAR THE I-20 CORRIDOR AROUND NOON FRIDAY...WITH THE DRYLINE
EXTENDING SOUTHWEST FROM THE FRONT ACROSS THE SOUTHWESTERN
COUNTIES BY NOON FRIDAY AS WELL. THESE BOUNDARIES SHOULD BOTH SERVE
AS A FOCUS FOR CONVECTION AS A SECOND UPPER LEVEL TROUGH PASSES
OVERHEAD. THIS FEATURE IS CURRENTLY OVER SOUTHERN CALIFORNIA AND
WILL MOVE QUICKLY EASTWARD INTO THE DESERT SOUTHWEST
TONIGHT...THEN ACROSS TEXAS TOMORROW. SUFFICIENT INSTABILITY WILL
BE PRESENT ONCE AGAIN WITH SLIGHTLY BETTER UPPER LEVEL SUPPORT IN
PLACE...AND ANY STORM THAT DEVELOPS MAY BECOME STRONG TO POSSIBLE
SEVERE. THE BEST CHANCES WILL AGAIN BE OVER THE EAST AND SOUTHEAST
COUNTIES WHERE THE HIGHEST MOISTURE LEVELS / 1 INCH OR GREATER
PWATS / WILL BE LOCATED. THE EXTENT OF THE CONVECTION IS SOMEWHAT
OF A QUESTION MARK...WITH NAM12 BEING AGGRESSIVE AND THE GFS MUCH
MORE PASSIVE AND FARTHER EAST WITH THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS. HIGHER COVERAGE THAN TODAY WOULD MAKE SENSE BASED
ON THE ADDITION OF THE COLD FRONT AND THE CLOSER PROXIMITY OF THE
UPPER LEVEL TROUGH. THIS MAY BE NEGATED THOUGH IF THE UPPER LEVEL
FEATURE MOVES ACROSS PRIOR TO PEAK HEATING...LEAVING US IN THE
SUBSIDENT REGION BY AFTERNOON. WE WILL MAINTAIN THE 40 POPS IN THE
EAST ZONES FOR FRIDAY...LOWERING TO 20 IN THE CENTRAL ZONES
INCLUDING THE DALLAS-FORT WORTH METROPLEX FOR NOW.
THIS SYSTEM WILL MOVE EAST OF THE REGION TOMORROW NIGHT...BRINGING
UPPER RIDGING...WIDESPREAD SUBSIDENCE AND NICE WEATHER TO NORTH
TEXAS FOR THE WEEKEND. PLENTIFUL SUN WILL ALLOW HIGH TEMPERATURES
TO CLIMB INTO THE MID AND UPPER 70S... WITH MOSTLY CLEAR SKIES
ALLOWING NIGHT TIME LOWS TO DROP INTO THE MID AND UPPER 40S. A
WEAK DISTURBANCE WILL MOVE ACROSS THE SOUTHERN PLAINS ON
MONDAY...BRINGING AN INCREASE IN CLOUDS BUT LITTLE IN THE WAY OF
PRECIPITATION. MODELS CONTINUE TO ADVERTISE A STRONGER UPPER
TROUGH DEEPENING OVER THE 4-CORNERS REGION WEDNESDAY...WHICH
SHOULD BRING A DECENT CHANCE OF SHOWERS AND THUNDERSTORMS DURING
THE MIDDLE PART OF NEXT WEEK.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 57 79 48 76 49 / 20 30 30 0 0
WACO, TX 59 82 49 77 48 / 20 50 50 0 0
PARIS, TX 60 76 45 73 45 / 40 20 20 0 0
DENTON, TX 53 77 45 75 44 / 20 20 20 0 0
MCKINNEY, TX 57 78 46 75 45 / 20 30 30 0 0
DALLAS, TX 59 79 49 76 50 / 20 30 30 0 0
TERRELL, TX 60 80 47 75 46 / 30 40 40 0 0
CORSICANA, TX 62 81 49 76 47 / 30 50 50 0 0
TEMPLE, TX 60 82 50 78 48 / 20 50 50 0 0
MINERAL WELLS, TX 51 80 45 77 44 / 10 10 10 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
106 PM CDT WED MAR 26 2014
.DISCUSSION...UPDATED FOR 18Z AVIATION.
&&
.AVIATION...CEILINGS ARE CURRENTLY A MIX OF VFR AND MVFR ACROSS
SOUTH TEXAS TERMINALS...WITH GUSTY WINDS EXPECTED THIS AFTERNOON
AT ALI/CRP/VCT. SHOWERS WITH ISOLATED THUNDERSTORMS HAVE DEVELOPED
ACROSS THE NORTHERN COASTAL PLAINS AND VICTORIA CROSSROADS. HAVE
INCLUDED -SHRA REMARKS AND A TEMPO GROUP FOR -TSRA AT VCT. LOWER
CONFIDENCE EXISTS AS TO WHETHER REDEVELOPMENT FARTHER TO THE SOUTH
BUT HAVE MAINTAINED VCSH REMARKS AT ALI/CRP FOR THE AFTERNOON.
GUSTY WINDS WILL SUBSIDE AFTER 00Z WITH A MVFR CEILINGS SETTLING
OVER SOUTH TEXAS. LOW CLOUDS WILL HANG AROUND THROUGH THE END OF
THE FORECAST CYCLE. ADDITIONAL RAIN CHANCES WILL EXIST TOMORROW
ESPECIALLY OVER THE NORTHEAST SECTIONS...AND HAVE INCLUDED VCTS
REMARKS AT VCT.
&&
.PREV DISCUSSION... /ISSUED 1153 AM CDT WED MAR 26 2014/
DISCUSSION...LARGE AREA OF PRECIPITATION IS LOCATED NORTH OF THE
AREA WITH SHOWERS AND ISOLATED THUNDERSTORMS OVER THE GULF WATERS.
EARLIER RUN OF THE HRRR SHOWED AN OVERALL DOWNWARD TREND IN PRECIP
FOR THE AFTERNOON...BUT CONFIDENCE IS NOT HIGH ENOUGH TO LOWER
POPS DRASTICALLY WITH SUFFICIENT MOISTURE AND JET STREAK NEARBY.
CONDITIONS WILL REMAIN MOSTLY CLOUDY THROUGH THE AFTERNOON THOUGH A
FEW BREAKS MAY BE POSSIBLE AT TIMES. TEMPERATURES WILL GENERALLY
BE IN THE 60S TO LOWER 70S THIS AFTERNOON. MARINE HEADLINES APPEAR
TO BE IN GOOD SHAPE WITH STRONG OFFSHORE FLOW IN PLACE. UPDATED
PRODUCTS OUT.
PREV DISCUSSION... /ISSUED 638 AM CDT WED MAR 26 2014/
DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
AVIATION...CONTINUE TO ANTICIPATE NON-CONVECTIVE LLWS AT VCT AND
ALI DRG THE 09-14Z PERIOD THIS MORNING. ALSO CONTINUE TO EXPECT A
TRANSITION TO MVFR CEILINGS BY MID MORNING TODAY. ADDITIONAL
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EXPECTED TODAY.
EXPECT MVFR VISIBILITIES NEAR SHOWERS/STORMS. ANTICIPATE THAT PCPN
WL PERSIST THROUGH THE REMAINDER OF THE TAF PERIOD. BREEZY ONSHORE
FLOW EXPECTED TO DEVELOP OVER THE REGION BY MID MORNING. WIND
SHOULD DECREASE AFTER 00Z THURSDAY. PATCHY SEA FOG ANTICIPATED DRG
THE 06-12Z THU PERIOD OVER THE BAYS/NEARSHORE WATERS YET EAST OF
CRP AND VCT.
PREV DISCUSSION... /ISSUED 456 AM CDT WED MAR 26 2014/
SHORT TERM (TODAY THROUGH THURSDAY)...WATER VAPOR IMAGERY
REVEALS AN UPPER LEVEL DISTURBANCE MOVING ACRS WRN TX. THE BULK OF
THE DYNAMICS IS EXPECTED TO REMAIN NORTH OF THE CWA AS IT MOVES
EAST. HOWEVER...JET DYNAMICS IS EXPECTED TO PERSIST OVER THE
REGION DURING THE PERIOD. PWAT VALUES OVER THE CWA/MSA ARE
SIGNIFICANTLY GREATER THAN NORMAL. THE COMBINATION OF MSTR AND
DYNAMICS WL CONTRIBUTE TO CONVECTION YET WITH INSTABILITY AS THE
LIMITING FACTOR. THUS EXPECT SCT SHOWERS AND ISOLD THUNDERSTORMS
OVER THE REGION TODAY. NAM DETERMINISTIC DEPICT 30KT 925MB ONSHORE
FLOW TODAY WHICH IS PROGD TO MIX TOWARD THE SFC. YET FEEL THAT
COOL TEMPS WL LIMIT VERTICAL MIXING. WL FCST BREEZY/WINDY
CONDITIONS YET BELOW THE WIND ADVSY THRESHOLD. JET DYNAMICS AND
SUFFICIENT MSTR SHOULD MAINTAIN AT LEAST SCT SHOWER ACTIVITY
TONIGHT. EXPECT CONVECTIVE ACTIVITY TO DECREASE FROM WEST TO EAST
THURSDAY AS DRIER AIR FILTERS INTO THE AREA. SIGNIFICANTLY WARMER
MAX TEMPS EXPECTED OVER THE WRN CWA.
MARINE...SCA CONDITIONS EXPECTED OVER THE WATERS TODAY AND TO
CONTINUE OVER THE COASTAL WATERS TONIGHT OWING TO BOTH WIND AND
SEAS. EXPECT A MODERATE RIP CURRENT RISK TODAY. YET A LOW RISK
THURSDAY AS WIND VEERS TO THE SOUTH. OWING TO THE FOREGOING JET
DYNAMICS AND MSTR...EXPECT SCT CONVECTION TODAY AND THURSDAY.
LONG TERM (THURSDAY NIGHT THROUGH MONDAY)...LOW CHANCES FOR
PRECIP FRIDAY DUE TO LIMITED MOISTURE OVER THE REGION. LINGERING
SCA CONDITIONS FROM SHORT TERM WILL END BY FRIDAY MORNING. SURFACE
PRESSURE TROUGH WILL MOVE INTO THE AREA LEADING TO W/WNW FLOW OVER
THE BRUSH COUNTRY AND DRYLINE RIGHT IN THE MIDDLE OF THE CWA.
EASTERN ZONES WILL STILL SEE LIMITED MOISTURE...BUT SOUTH WINDS AT
THE SURFACE COMBINED WITH A WEAK SHORTWAVE MOVING THROUGH THE
REGION MAY HELP TO BRIEFLY MOISTEN THINGS UP ENOUGH TO ENABLE A
FEW ISOLATED SHOWERS OVER THE NORTHERN COASTAL BEND AND VICTORIA
CROSSROADS. REGARDLESS...TEMPERATURES WILL BE WELL ABOVE AVERAGE
FOR MUCH OF THE CWA FRIDAY...PARTICULARLY OVER THE BRUSH COUNTRY.
A DRY COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION SATURDAY
MORNING...BRINGING N/NE WINDS AND MORE SEASONAL TEMPERATURES.
SURFACE PRESSURE RIDGE BEHIND THE FRONT WILL SETTLE IN BRIEFLY
BEFORE SHIFTING EASTWARD SUNDAY MORNING. DRY MID/UPPER LEVELS WILL
LEAD TO A DRY...CLEAR...AND VERY WARM MONDAY. MOISTURE WILL
GRADUALLY RETURN TUESDAY...WITH INCREASING CLOUD COVER AND
SLIGHTLY LOWER TEMPERATURES AS A RESULT. HAVE GONE WITH 20% POPS
FOR DAY 7 AND DAY 8 AS PWATS MAY INCREASE TO A POINT THAT WILL
ALLOW LIMITED CONVECTIVE ACTIVITY. HIGH DEWPOINTS HAVE PROMPTED ME
TO PUT A MENTION OF FOG IN THE FORECAST FOR TUESDAY. HIGHER WINDS
WEDNESDAY DUE TO A LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS
WILL PROBABLY PREVENT MUCH IN THE WAY OF FOG DEVELOPMENT...SO HAVE
NOT PUT IN FOG WEDNESDAY MORNING DESPITE HIGH MAXIMUM RH VALUES.
GFS MAY BE HINTING AT A COLD FRONT AT THE END OF THE PERIOD...BUT
ECM DISAGREES. WIND FIELDS ON DAY 8 REFLECT THIS POSSIBILITY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 65 81 66 88 62 / 50 30 10 10 10
VICTORIA 61 78 65 85 59 / 50 40 10 20 10
LAREDO 65 91 66 95 64 / 30 20 10 10 10
ALICE 63 86 63 93 62 / 50 30 10 10 10
ROCKPORT 64 72 67 79 60 / 50 40 10 20 10
COTULLA 61 88 61 91 56 / 30 20 10 10 10
KINGSVILLE 65 84 65 91 64 / 50 30 10 10 10
NAVY CORPUS 64 74 68 82 63 / 50 40 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THURSDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT
20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
&&
$$
XX/99...AVIATION
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
104 PM CDT WED MAR 26 2014
.DISCUSSION...
18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
MID TO UPPER LEVEL RIDGING AND DRY LOWER LEVELS HAVE PRECIPITATION
REMAINING MAINLY VIRGA THROUGH THE 18Z HOUR. A NICE SWATH OF PRIMARILY
LIGHT RAIN RIDING IN ALONG THE I-10 CORRIDOR...WITH LIGHTNING BEING
REPORTED OFF TO THE FAR SOUTHWEST OVER SAN ANTONIO`S AIR SPACE.
KEPT MAINLY VCSH WITH A CENTRAL HUB TEMPO OF PASSING LIGHT SHOWERS
AND VFR OVERCAST. LOWER LEVELS WILL SATURATE UP THROUGH THE AFTERNOON
SO LOWERING CEILINGS TO MVFR THROUGH MID TO LATE EVENING...A MODERATE
CHANCE FOR FOR PRE-SUNRISE IFR DECKS. A BREAK IN THE EVENING INTO
EARLY MORNING PRECIPITATION-WISE AS REGION FALLS BETWEEN SHORTWAVE
DISTURBANCES. INCREASING INSTABILITY MOVING IN FROM THE WEST MID
TO LATE THURSDAY MORNING AS MID-LEVEL RIDGING BREAKS DOWN AHEAD OF
THE NEXT WEAK WESTERN PLAINS SHORTWAVE TROUGH. HIGHER PROBABILITY
OF RETURNING RAIN...WITH POSSIBLE THUNDER ...DURING THIS TAF`S
LATE PERIOD. 31
&&
.PREV DISCUSSION... /ISSUED 1022 AM CDT WED MAR 26 2014/
DISCUSSION...
A SMATTERING OF LIGHT RAIN MOVING ACROSS THE NORTHERN PART OF THE
CWA THIS MORNING BUT MOST OF THE PRECIP IS EVAPORATING BEFORE
REACHING THE GROUND. A SECOND AREA OF PRECIP OVER CENTRAL TEXAS
WILL MOVE EAST THIS AFTN AND AFFECT MAINLY THE CENTRAL/SOUTHERN PART
OF THE CWA. HRRR HAS VERIFIED BEST THIS MORNING SO WILL LEAN
TOWARD THE LESS AGGRESSIVE HRRR FOR RAIN CHANCES/AMOUNTS. TEMP
FCST LOOKS GOOD SO NO CHANGES THERE. NEW ZONES OUT BY 1030 AM. 43
&&
PREV DISCUSSION... /ISSUED 348 AM CDT WED MAR 26 2014/
DISCUSSION...
VERY LIGHT PCPN CONTINUING TO MOVE IN FROM THE W/SW THIS MORNING
WITH RAINFALL RATES SLOWLY INCREASING THROUGH THE DAY AS THE AIR-
MASS SLOWLY MOISTENS. THIS INITIAL SHORTWAVE IS EXPECTED TO MOVE
EAST OF THE CWA BY THIS EVENING. A BRIEF BREAK OVERNIGHT BUT NOT
COMPLETELY DRY AS THE OVERRUNNING PATTERN ALONG WITH STRONG WAA/
ONSHORE FLOW PRODUCES PATCHY AREAS OF -RA/DZ/FG. RAIN CHANCES TO
INCREASE ONCE AGAIN ON THURS AS ANOTHER DISTURBANCE MOVES IN VIA
THE SUBTROPICAL JET. PROGGED JET DYNAMICS (LFQ)/LAPSE RATES LOOK
GOOD...BUT THERE ARE STILL CONCERNS REGARDING INSTABILITY WITH A
LINGERING BKN/OVC DECK LIMITING THE POSSIBLE HEATING. NO MENTION
OF SVR FOR THURS PLANNED ATTM...BUT WILL HAVE TO SEE HOW DETAILS
EVOLVE TONIGHT.
KEEPING FAIRLY LOW POPS IN FOR FRI/FRI NIGHT WITH THE PASSAGE OF
ANOTHER COLD FRONT. WEAK CAA COMBINED WITH WEAK RIDGING ALOFT IN
THE WAKE OF THIS BOUNDARY SHOULD ALLOW FOR A GENERALLY QUIET/DRY
WEEKEND WITH NEAR SEASONAL TEMPS. EXTENDED GUIDANCE INDICATING A
POSSIBLE BACKDOOR COLD FRONT ON MON ALONG WITH THE RETURN OF THE
SWLY FLOW ALOFT/POPS FOR SE TX LATE NEXT TUES/WEDS. 41
&&
MARINE...
EAST AND SOUTHEAST WINDS WILL BE THE NORM EARLY THIS MORNING WITH
WINDS INCREASING AS PRESSURES FALL IN THE LEE OF THE SOUTHERN
ROCKIES. LLJ DEVELOPING FROM BRO TO SJT TO AMA AT 06Z AND WILL
EXPAND EASTWARD TO BLANKET THE WESTERN COASTAL WATERS AND AREAS
FROM HUNTSVILLE TO GALVESTON AND WELL OUT INTO THE GULF. WINDS
WILL BE INCREASING STEADILY THIS MORNING AND WILL MAINTAIN THE SCA
FOR ALL WATERS AND HAVE EXTENDED IT INTO THURSDAY AFTERNOON. SEAS
BUILDING AND FETCH FROM THE CENTRAL GULF WILL BRING IN INCREASING
SWELLS WITH THE WIND WAVE INCREASE LOCALLY...SUSTAINED WINDS OF
NEAR 20 KNOTS NEARING 25-30 KNOTS FOR THE LATE AFTERNOON/EVENING
HOURS. RAIN CHANCES INCREASING LATE THIS AFTERNOON THROUGH THE
EVENING AND MAY PEAK ON THURSDAY AS S/W ROTATES THROUGH NCTX AND
SUBTROPICAL JET NOSES INTO COASTAL AREAS 6 PM THURSDAY. WILL NEED
TO KEEP A CLOSE EYE ON STORM THAT MAY DEVELOP OVER THE NORTHERN
CWA AND POTENTIALLY TRACK SE INTO THE GALVESTON BAY AND NEARSHORE
WATERS LATE THURSDAY AFTERNOON AND EVENING. GRADIENT RELAXES MAIN
TROUGH AXIS SWINGS THROUGH THE STATE FRIDAY WHICH SHOULD PUSH A
COLD FRONT THROUGH AND INTO THE GULF SATURDAY MORNING. SCA CONDITIONS
MAY BE POSSIBLE FROM AROUND 4 AM THROUGH 4 PM SATURDAY. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 58 76 64 83 55 / 30 60 20 20 20
HOUSTON (IAH) 60 76 65 82 58 / 30 60 20 20 20
GALVESTON (GLS) 63 72 66 75 63 / 30 60 30 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 3 PM CDT THURSDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...31
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1153 AM CDT WED MAR 26 2014
.DISCUSSION...LARGE AREA OF PRECIPITATION IS LOCATED NORTH OF THE
AREA WITH SHOWERS AND ISOLATED THUNDERSTORMS OVER THE GULF WATERS.
EARLIER RUN OF THE HRRR SHOWED AN OVERALL DOWNWARD TREND IN PRECIP
FOR THE AFTERNOON...BUT CONFIDENCE IS NOT HIGH ENOUGH TO LOWER
POPS DRASTICALLY WITH SUFFICIENT MOISTURE AND JET STREAK NEARBY.
CONDITIONS WILL REMAIN MOSTLY CLOUDY THROUGH THE AFTERNOON THOUGH A
FEW BREAKS MAY BE POSSIBLE AT TIMES. TEMPERATURES WILL GENERALLY
BE IN THE 60S TO LOWER 70S THIS AFTERNOON. MARINE HEADLINES APPEAR
TO BE IN GOOD SHAPE WITH STRONG OFFSHORE FLOW IN PLACE. UPDATED
PRODUCTS OUT.
&&
.PREV DISCUSSION... /ISSUED 638 AM CDT WED MAR 26 2014/
DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
AVIATION...CONTINUE TO ANTICIPATE NON-CONVECTIVE LLWS AT VCT AND
ALI DRG THE 09-14Z PERIOD THIS MORNING. ALSO CONTINUE TO EXPECT A
TRANSITION TO MVFR CEILINGS BY MID MORNING TODAY. ADDITIONAL
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EXPECTED TODAY.
EXPECT MVFR VISIBILITIES NEAR SHOWERS/STORMS. ANTICIPATE THAT PCPN
WL PERSIST THROUGH THE REMAINDER OF THE TAF PERIOD. BREEZY ONSHORE
FLOW EXPECTED TO DEVELOP OVER THE REGION BY MID MORNING. WIND
SHOULD DECREASE AFTER 00Z THURSDAY. PATCHY SEA FOG ANTICIPATED DRG
THE 06-12Z THU PERIOD OVER THE BAYS/NEARSHORE WATERS YET EAST OF
CRP AND VCT.
PREV DISCUSSION... /ISSUED 456 AM CDT WED MAR 26 2014/
SHORT TERM (TODAY THROUGH THURSDAY)...WATER VAPOR IMAGERY
REVEALS AN UPPER LEVEL DISTURBANCE MOVING ACRS WRN TX. THE BULK OF
THE DYNAMICS IS EXPECTED TO REMAIN NORTH OF THE CWA AS IT MOVES
EAST. HOWEVER...JET DYNAMICS IS EXPECTED TO PERSIST OVER THE
REGION DURING THE PERIOD. PWAT VALUES OVER THE CWA/MSA ARE
SIGNIFICANTLY GREATER THAN NORMAL. THE COMBINATION OF MSTR AND
DYNAMICS WL CONTRIBUTE TO CONVECTION YET WITH INSTABILITY AS THE
LIMITING FACTOR. THUS EXPECT SCT SHOWERS AND ISOLD THUNDERSTORMS
OVER THE REGION TODAY. NAM DETERMINISTIC DEPICT 30KT 925MB ONSHORE
FLOW TODAY WHICH IS PROGD TO MIX TOWARD THE SFC. YET FEEL THAT
COOL TEMPS WL LIMIT VERTICAL MIXING. WL FCST BREEZY/WINDY
CONDITIONS YET BELOW THE WIND ADVSY THRESHOLD. JET DYNAMICS AND
SUFFICIENT MSTR SHOULD MAINTAIN AT LEAST SCT SHOWER ACTIVITY
TONIGHT. EXPECT CONVECTIVE ACTIVITY TO DECREASE FROM WEST TO EAST
THURSDAY AS DRIER AIR FILTERS INTO THE AREA. SIGNIFICANTLY WARMER
MAX TEMPS EXPECTED OVER THE WRN CWA.
MARINE...SCA CONDITIONS EXPECTED OVER THE WATERS TODAY AND TO
CONTINUE OVER THE COASTAL WATERS TONIGHT OWING TO BOTH WIND AND
SEAS. EXPECT A MODERATE RIP CURRENT RISK TODAY. YET A LOW RISK
THURSDAY AS WIND VEERS TO THE SOUTH. OWING TO THE FOREGOING JET
DYNAMICS AND MSTR...EXPECT SCT CONVECTION TODAY AND THURSDAY.
LONG TERM (THURSDAY NIGHT THROUGH MONDAY)...LOW CHANCES FOR
PRECIP FRIDAY DUE TO LIMITED MOISTURE OVER THE REGION. LINGERING
SCA CONDITIONS FROM SHORT TERM WILL END BY FRIDAY MORNING. SURFACE
PRESSURE TROUGH WILL MOVE INTO THE AREA LEADING TO W/WNW FLOW OVER
THE BRUSH COUNTRY AND DRYLINE RIGHT IN THE MIDDLE OF THE CWA.
EASTERN ZONES WILL STILL SEE LIMITED MOISTURE...BUT SOUTH WINDS AT
THE SURFACE COMBINED WITH A WEAK SHORTWAVE MOVING THROUGH THE
REGION MAY HELP TO BRIEFLY MOISTEN THINGS UP ENOUGH TO ENABLE A
FEW ISOLATED SHOWERS OVER THE NORTHERN COASTAL BEND AND VICTORIA
CROSSROADS. REGARDLESS...TEMPERATURES WILL BE WELL ABOVE AVERAGE
FOR MUCH OF THE CWA FRIDAY...PARTICULARLY OVER THE BRUSH COUNTRY.
A DRY COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION SATURDAY
MORNING...BRINGING N/NE WINDS AND MORE SEASONAL TEMPERATURES.
SURFACE PRESSURE RIDGE BEHIND THE FRONT WILL SETTLE IN BRIEFLY
BEFORE SHIFTING EASTWARD SUNDAY MORNING. DRY MID/UPPER LEVELS WILL
LEAD TO A DRY...CLEAR...AND VERY WARM MONDAY. MOISTURE WILL
GRADUALLY RETURN TUESDAY...WITH INCREASING CLOUD COVER AND
SLIGHTLY LOWER TEMPERATURES AS A RESULT. HAVE GONE WITH 20% POPS
FOR DAY 7 AND DAY 8 AS PWATS MAY INCREASE TO A POINT THAT WILL
ALLOW LIMITED CONVECTIVE ACTIVITY. HIGH DEWPOINTS HAVE PROMPTED ME
TO PUT A MENTION OF FOG IN THE FORECAST FOR TUESDAY. HIGHER WINDS
WEDNESDAY DUE TO A LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS
WILL PROBABLY PREVENT MUCH IN THE WAY OF FOG DEVELOPMENT...SO HAVE
NOT PUT IN FOG WEDNESDAY MORNING DESPITE HIGH MAXIMUM RH VALUES.
GFS MAY BE HINTING AT A COLD FRONT AT THE END OF THE PERIOD...BUT
ECM DISAGREES. WIND FIELDS ON DAY 8 REFLECT THIS POSSIBILITY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 70 65 81 66 88 / 40 50 30 10 10
VICTORIA 68 61 78 65 85 / 40 50 40 10 20
LAREDO 74 65 91 66 95 / 30 30 20 10 10
ALICE 70 63 86 63 93 / 30 50 30 10 10
ROCKPORT 69 64 72 67 79 / 40 50 40 10 20
COTULLA 70 61 88 61 91 / 30 30 20 10 10
KINGSVILLE 70 65 84 65 91 / 40 50 30 10 10
NAVY CORPUS 69 64 74 68 82 / 40 50 40 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THURSDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT
20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
&&
$$
TB/78...SHORT TERM
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1022 AM CDT WED MAR 26 2014
.DISCUSSION...
A SMATTERING OF LIGHT RAIN MOVING ACROSS THE NORTHERN PART OF THE
CWA THIS MORNING BUT MOST OF THE PRECIP IS EVAPORATING BEFORE
REACHING THE GROUND. A SECOND AREA OF PRECIP OVER CENTRAL TEXAS
WILL MOVE EAST THIS AFTN AND AFFECT MAINLY THE CENTRAL/SOUTHERN PART
OF THE CWA. HRRR HAS VERIFIED BEST THIS MORNING SO WILL LEAN
TOWARD THE LESS AGGRESSIVE HRRR FOR RAIN CHANCES/AMOUNTS. TEMP
FCST LOOKS GOOD SO NO CHANGES THERE. NEW ZONES OUT BY 1030 AM. 43
&&
.PREV DISCUSSION... /ISSUED 656 AM CDT WED MAR 26 2014/
DISCUSSION...
12Z AVIATION DISCUSSION BELOW.
AVIATION...
MOISTURE INCREASING WITH STRENGTHENED SOUTHEASTERLIES AS EARLY
DAY HIGH OVERCAST TRANSITIONS TO LOW-END VFR DECKS BY SUNSET.
A MODERATE SUSTAINED...STRONG IN GUST...SOUTHEASTERLY WIND OVER
MORE CENTRAL AND WESTERN FORECAST AREA TERMINALS FROM AROUND 18Z
THROUGH 00-01Z. OCCASIONAL DRIZZLE OR SPRINKLES THROUGH THE
MAJORITY OF THE DAY...HIGHER CHANCES FOR LIGHT RAIN OR PASSING
SHOWERS FROM THIS EVENING THROUGH THURSDAY SUNRISE. THE PASSAGE OF
A SOUTHWESTERLY DISTURBANCE WILL HEIGHTEN THE CHANCE OF RECEIVING
MORE STEADY OR PERSISTENT RAIN DURING THE LATE EVENING THROUGH
EARLY THURSDAY MORNING HOURS. REGIONAL ATMOSPHERE WILL REMAIN
STABLE THROUGH AT LEAST LATE THURSDAY MORNING SO...WITH A GRADUAL
SATURATION OF THE LOWER LEVELS TODAY...JUST RAIN WITH NO THUNDER
IS FORECAST IN THIS 26/12Z PACKAGE. CEILING TREND WILL BE TO FALL
TO MVFR FROM AS EARLY AS 27/02-04Z WITH AREAWIDE MVFR BY 27/08-10Z
..WITH A REMOTE CHANCE OF PERIODIC IFR. 31
PREV DISCUSSION... /ISSUED 348 AM CDT WED MAR 26 2014/
DISCUSSION...
VERY LIGHT PCPN CONTINUING TO MOVE IN FROM THE W/SW THIS MORNING
WITH RAINFALL RATES SLOWLY INCREASING THROUGH THE DAY AS THE AIR-
MASS SLOWLY MOISTENS. THIS INITIAL SHORTWAVE IS EXPECTED TO MOVE
EAST OF THE CWA BY THIS EVENING. A BRIEF BREAK OVERNIGHT BUT NOT
COMPLETELY DRY AS THE OVERRUNNING PATTERN ALONG WITH STRONG WAA/
ONSHORE FLOW PRODUCES PATCHY AREAS OF -RA/DZ/FG. RAIN CHANCES TO
INCREASE ONCE AGAIN ON THURS AS ANOTHER DISTURBANCE MOVES IN VIA
THE SUBTROPICAL JET. PROGGED JET DYNAMICS (LFQ)/LAPSE RATES LOOK
GOOD...BUT THERE ARE STILL CONCERNS REGARDING INSTABILITY WITH A
LINGERING BKN/OVC DECK LIMITING THE POSSIBLE HEATING. NO MENTION
OF SVR FOR THURS PLANNED ATTM...BUT WILL HAVE TO SEE HOW DETAILS
EVOLVE TONIGHT.
KEEPING FAIRLY LOW POPS IN FOR FRI/FRI NIGHT WITH THE PASSAGE OF
ANOTHER COLD FRONT. WEAK CAA COMBINED WITH WEAK RIDGING ALOFT IN
THE WAKE OF THIS BOUNDARY SHOULD ALLOW FOR A GENERALLY QUIET/DRY
WEEKEND WITH NEAR SEASONAL TEMPS. EXTENDED GUIDANCE INDICATING A
POSSIBLE BACKDOOR COLD FRONT ON MON ALONG WITH THE RETURN OF THE
SWLY FLOW ALOFT/POPS FOR SE TX LATE NEXT TUES/WEDS. 41
MARINE...
EAST AND SOUTHEAST WINDS WILL BE THE NORM EARLY THIS MORNING WITH
WINDS INCREASING AS PRESSURES FALL IN THE LEE OF THE SOUTHERN
ROCKIES. LLJ DEVELOPING FROM BRO TO SJT TO AMA AT 06Z AND WILL
EXPAND EASTWARD TO BLANKET THE WESTERN COASTAL WATERS AND AREAS
FROM HUNTSVILLE TO GALVESTON AND WELL OUT INTO THE GULF. WINDS
WILL BE INCREASING STEADILY THIS MORNING AND WILL MAINTAIN THE SCA
FOR ALL WATERS AND HAVE EXTENDED IT INTO THURSDAY AFTERNOON. SEAS
BUILDING AND FETCH FROM THE CENTRAL GULF WILL BRING IN INCREASING
SWELLS WITH THE WIND WAVE INCREASE LOCALLY...SUSTAINED WINDS OF
NEAR 20 KNOTS NEARING 25-30 KNOTS FOR THE LATE AFTERNOON/EVENING
HOURS. RAIN CHANCES INCREASING LATE THIS AFTERNOON THROUGH THE
EVENING AND MAY PEAK ON THURSDAY AS S/W ROTATES THROUGH NCTX AND
SUBTROPICAL JET NOSES INTO COASTAL AREAS 6 PM THURSDAY. WILL NEED
TO KEEP A CLOSE EYE ON STORM THAT MAY DEVELOP OVER THE NORTHERN
CWA AND POTENTIALLY TRACK SE INTO THE GALVESTON BAY AND NEARSHORE
WATERS LATE THURSDAY AFTERNOON AND EVENING. GRADIENT RELAXES MAIN
TROUGH AXIS SWINGS THROUGH THE STATE FRIDAY WHICH SHOULD PUSH A
COLD FRONT THROUGH AND INTO THE GULF SATURDAY MORNING. SCA CONDITIONS
MAY BE POSSIBLE FROM AROUND 4 AM THROUGH 4 PM SATURDAY. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 66 58 76 64 83 / 50 30 60 20 20
HOUSTON (IAH) 67 60 76 65 82 / 40 30 60 20 20
GALVESTON (GLS) 66 63 72 66 75 / 40 30 60 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 3 PM CDT THURSDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1217 AM CDT WED MAR 26 2014
.DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
&&
.AVIATION...ANTICIPATE NON-CONVECTIVE LLWS CONDITION TO OCCUR AT
VCT AND ALI MAINLY DRG THE 09-14Z WED PERIOD. EXPECT A TRANSITION
TO MVFR CEILINGS BY MID MORNING WEDNESDAY...ALONG WITH SCATTERED
SHOWER ACTIVITY RESULTING IN MVFR VISIBILITIES. CONDITION
CHARACTERIZED BY MVFR CEILINGS/MVFR VSBYS NEAR SHOWERS WL THEN PERSIST
THROUGH THE REMAINDER OF THE PERIOD. BREEZY ONSHORE FLOW EXPECTED
TO DEVELOP OVER THE REGION BY MID MORNING WED THEN CONTINUE UNTIL
THE EARLY EVENING.
&&
.PREV DISCUSSION... /ISSUED 924 PM CDT TUE MAR 25 2014/
DISCUSSION...HAVE MADE SEVERAL CHANGES TO THE ONGOING FORECAST.
00Z KCRP RAOB SHOWS VERY DRY AIRMASS FROM SFC TO H6 THOUGH PWAT
ANALYSIS INDICATES DEEPER MOISTURE LOCATED ACROSS FAR SOUTHERN AND
WESTERN ZONES. A S/W TROUGH CURRENTLY MOVING EAST ACROSS COAHUILA
MX WILL APPROACH THE RIO GRANDE AFTER MIDNIGHT. LIGHT TO AT TIMES
MODERATE PRECIP IS EXPECTED TO DEVELOP OVERNIGHT...THOUGH IT WILL
TAKE SOME TIME FOR PRECIP TO REACH THE SURFACE DUE TO DRIER LOWER
LEVELS /ESPECIALLY ACROSS THE EAST/. HAVE REDUCED POPS FOR THIS
EVENING...BUT INCREASED POPS FOR AFTER MIDNIGHT ALONG THE RIO
GRANDE. HAVE LEANED TOWARDS LATEST AVAILABLE HRRR AND SPC 4KM WRF
GUIDANCE FOR POPS FOR TONIGHT. OTHER CHANGES TO FORECAST WERE TO
REDUCE MENTION OF THUNDER FOR TONIGHT AND TO INCREASE WIND SPEEDS
FOR WED AND WED NIGHT /DUE TO EXPECTED STRENGTHENING LLJ/.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 69 67 81 67 82 / 60 30 20 10 10
VICTORIA 65 63 79 65 83 / 70 40 40 10 10
LAREDO 73 68 92 69 93 / 30 20 10 10 10
ALICE 70 65 87 66 86 / 50 30 20 10 10
ROCKPORT 69 67 70 68 78 / 60 30 20 10 10
COTULLA 69 64 87 64 88 / 40 20 10 10 10
KINGSVILLE 70 66 84 67 84 / 50 30 20 10 10
NAVY CORPUS 70 67 76 67 77 / 60 30 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THURSDAY FOR THE FOLLOWING
ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60
NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL
FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM
BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT
ARANSAS TO PORT O`CONNOR.
SMALL CRAFT ADVISORY UNTIL 7 AM CDT THURSDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT
20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP
CHANNEL OUT 20 NM.
&&
$$
WC/87...AVIATION
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
1057 AM PDT WED MAR 26 2014
.SYNOPSIS...A showery and unsettled spring time weather pattern
will persist through Thursday. A few thunderstorms will also be
possible this afternoon and again on Thursday. Temperatures will
gradually cool through the rest of the week. The cooler
temperatures will allow snow to fall over the mountains and the
higher elevations of the Inland Northwest. A wetter but warmer
system will track into the region on Friday and persist into the
weekend. This will result in widespread rain and high mountain
snow.
&&
.DISCUSSION...
Forecast update sent out for the rest of this morning through this
afternoon. I generally decreased chances for precip and cloud
cover across the region for this morning, especially across the
northern half. Visible satellite imagery shows quite a bit of
clear across much of the region. We will continue to destabilize
into this afternoon as surface temps warm up. A 500 mb cold pool
of around -28 degrees Celsius should provide enough instability
for isolated to scattered showers across much of the region,
especially across the mountains. The GFS and NAM model solutions
show the best instability of up to around 200 J/KG of surface base
CAPE across the extreme SE portions of WA and into the central ID
Panhandle. Equilibrium heights will be up to around 20 kft or so,
which is suitable for some isolated thunderstorms. This will
include locations in the Northeast Blue Mountains and foothills,
Palouse, L-C Valley, Camas Prairie and in the Central Panhandle
Mtns. There is also a chance we could see an isolated thunderstorm
or two across the Northeast Mtns and Northern Panhandle, but
confidence is even lower due to weaker instability off of the
models exhibited here.
Another upper level low pressure system is beginning to push into
western WA and OR this morning. This is producing some light
precip west of the Cascades with some mid to high level cloud
cover pushing east of the Cascade crest and into the western
basin. This cloud cover is expected to limit the surface heating
over the Cascades this afternoon; in turn, this will limit how
much instability that can be achieved. I went ahead and removed
thunderstorms from the forecast in this area. We will see an
increasing chance for showers this afternoon into the Cascades
with this precip spreading further into eastern WA and into the ID
Panhandle through tonight. /SVH
&&
.AVIATION...
18Z TAFS: The region will be under an unstable air mass this
afternoon with Scattered showers developing across much of the
region by the early afternoon hours. Deeper convection will be
possible near the KPUW and KLWS TAF sites after 20Z with isolated
thunderstorms possible. However, confidence for thunderstorms is
not high enough at this time to include in the TAFs. A low
pressure system spinning offshore of WA this morning will push
inland tonight. This will push across a band of rain through the
overnight hours from southwest to northeast. Moist upslope flow at
the KGEG, KSFF and KCOE TAF sites is expected to drop cigs into
MVFR category through Thursday morning; MVFR cigs will also be
possible at KEAT overnight with the rain. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 37 48 33 47 38 / 30 70 80 40 100 80
Coeur d`Alene 51 34 45 33 47 36 / 30 70 90 60 90 90
Pullman 52 38 47 34 49 39 / 50 70 70 50 90 100
Lewiston 57 41 52 36 55 44 / 50 70 70 50 70 80
Colville 56 32 51 34 51 35 / 40 60 70 30 100 80
Sandpoint 48 32 44 34 45 34 / 40 60 90 70 90 90
Kellogg 48 34 44 33 46 35 / 50 70 100 80 90 100
Moses Lake 59 39 57 38 55 40 / 20 40 20 20 80 40
Wenatchee 58 38 56 37 53 36 / 30 50 20 20 80 50
Omak 59 34 56 33 51 34 / 20 50 30 20 70 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
956 AM PDT WED MAR 26 2014
.SYNOPSIS...A showery and unsettled spring time weather pattern
will persist through Thursday. A few thunderstorms will also be
possible this afternoon and again on Thursday. Temperatures will
gradually cool through the rest of the week. The cooler
temperatures will allow snow to fall over the mountains and the
higher elevations of the Inland Northwest. A wetter but warmer
system will track into the region on Friday and persist into the
weekend. This will result in widespread rain and high mountain
snow.
&&
.DISCUSSION...
Forecast update sent out for the rest of this morning through this
afternoon. I generally decreased chances for precip and cloud
cover across the region for this morning, especially across the
northern half. Visible satellite imagery shows quite a bit of
clear across much of the region. We will continue to destabilize
into this afternoon as surface temps warm up. A 500 mb cold pool
of around -28 degrees Celsius should provide enough instability
for isolated to scattered showers across much of the region,
especially across the mountains. The GFS and NAM model solutions
show the best instability of up to around 200 J/KG of surface base
CAPE across the extreme SE portions of WA and into the central ID
Panhandle. Equilibrium heights will be up to around 20 kft or so,
which is suitable for some isolated thunderstorms. This will
include locations in the Northeast Blue Mountains and foothills,
Palouse, L-C Valley, Camas Prairie and in the Central Panhandle
Mtns. There is also a chance we could see an isolated thunderstorm
or two across the Northeast Mtns and Northern Panhandle, but
confidence is even lower due to weaker instability off of the
models exhibited here.
Another upper level low pressure system is beginning to push into
western WA and OR this morning. This is producing some light
precip west of the Cascades with some mid to high level cloud
cover pushing east of the Cascade crest and into the western
basin. This cloud cover is expected to limit the surface heating
over the Cascades this afternoon; in turn, this will limit how
much instability that can be achieved. I went ahead and removed
thunderstorms from the forecast in this area. We will see an
increasing chance for showers this afternoon into the Cascades
with this precip spreading further into eastern WA and into the ID
Panhandle through tonight. /SVH
&&
.AVIATION...
12Z TAFS: VFR conditions are expected at all sites through most of
the period. The exception will revolve around an MVFR cloud deck
impacting the COE area...and likely just east of SFF. No idea how
extensive the deck is since its totally obscured by high clouds on
satellite. Consequently we utilized RAP model data which shows
drier air moving in from the west by 17z as well as conditional
climatology. Anyway confidence is not high. Otherwise the main
weather feature for this afternoon and early evening will be a
rapid destabilization of the atmosphere and a growing possibility
of showers. Although the instability will not be that
impressive...there will be a small chance of thunderstorms over SE
WA which could be near LWS and perhaps PUW between 21z-02z. MWH
and EAT won`t see much of a chance today...but should see a
growing chance overnight as the atmosphere destabilizes even
further with the approach of a cold upper level low. The low will
head toward the WA/ID border after 06z...which will result in
numerous showers and a band of wraparound precipitation. THERE`S a
small chance of MVFR cigs developing near this band but we did not
have enough confidence to put in prevailing wording. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 37 48 33 47 38 / 30 70 80 40 100 80
Coeur d`Alene 51 34 45 33 47 36 / 30 70 90 60 90 90
Pullman 52 38 47 34 49 39 / 50 70 70 50 90 100
Lewiston 57 41 52 36 55 44 / 50 70 70 50 70 80
Colville 56 32 51 34 51 35 / 40 60 70 30 100 80
Sandpoint 48 32 44 34 45 34 / 40 60 90 70 90 90
Kellogg 48 34 44 33 46 35 / 50 70 100 80 90 100
Moses Lake 59 39 57 38 55 40 / 20 40 20 20 80 40
Wenatchee 58 38 56 37 53 36 / 30 50 20 20 80 50
Omak 59 34 56 33 51 34 / 20 50 30 20 70 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
919 AM PDT WED MAR 26 2014
.SYNOPSIS...COOL AND SHOWERY WEATHER CONTINUES TODAY. A STRONG
FRONTAL SYSTEM WILL MARCH ACROSS THE REGION LATE THU NIGHT AND FRI.
WARM FRONT WILL SPREAD STEADY RAIN AND BREEZY CONDITIONS INTO THE
AREA LATER THU NIGHT. THEN COLD FRONT ARRIVES LATE FRI. THIS FRONT
WILL SAG S INTO CALIFORNIA FRI NIGHT AND SAT...WITH A RETURN TO COOL
SHOWERY WEATHER FOR THE WEEKEND.
&&
.SHORT TERM...NOT MUCH CHANGE IN OVERALL TRENDS FOR TODAY AND
TONIGHT. UPPER LOW LOCATED OFF THE WA COAST THIS AM...WITH SHOWERS
CONTINUING TO PUSH INLAND. THE LOW IS VERTICALLY STACKED...AND WILL
SLOWLY WEAKEN IS IT MOVES INLAND OVER W WASH THROUGH TONIGHT. THIS
WILL MAINTAIN SHOWERY PATTERN ACROSS REGION...WITH LOCALLY BREEZY
CONDITIONS IN THE AFTERNOON INTO THIS EVENING. CAN NOT RULE OUT AN
ISOLATED THUNDERSTORM...BUT BEST THREAT IS TODAY RATHER THAN THU.
HOWEVER...THREAT NOT AS GOOD AS THAT ON TUE AS INSTABILITY WEAKER..
WINTER WX ADVISORY FOR SNOW REMAINS IN EFFECT FOR THE HIGH CASCADES
AT ELEVATIONS 4000 FT AND ABOVE FOR TONIGHT AND THU. LIKELY TO GET 3
TO 6 INCHES ABOUT EVERY 12 HOURS...BUT COULD BE BRIEF BURST SUCH THAT
SOME LOCALES GET MORE DURING THAT PERIOD.
ATTENTION THEN TURNS TO WHAT WILL LIKELY BE A MORE SUBSTANTIAL RAIN
EVENT THU NIGHT/FRI. AN UPPER LOW NOW IN THE VICINITY OF 45N/160W IS
STARTING TO DEVELOP A MOISTURE TAP INTO THE SUBTROPICS...WHICH WILL
PERSIST AS THIS SYSTEM APPROACHES. MODELS SHOW FAIRLY GOOD AGREEMENT
THAT A WARM FRONT WILL SPREAD RAIN ONSHORE INTO WRN OREGON/SW
WASHINGTON THU NIGHT...WITH AN OCCLUDING COLD FRONT CONTINUING THE
RAIN INTO FRI. WHERE MODELS STILL DIVERGE IS JUST HOW LONG THIS
FRONTAL ZONE WILL LINGER OVER THE REGION. THE 06Z NAM WANTS TO PIVOT
THE FRONT OVER W OREGON FRI...WHILE THE 00Z/06Z GFS PUSH THE
FRONT SOUTH FASTER WITH LESS QPF FOR OUR AREA. THE 00Z ECMWF IS A
COMPROMISE BETWEEN THE NAM/GFS SOLUTIONS. OVERALL IT IS APPEARING
FAIRLY LIKELY THAT THERE WILL BE SOME SORT OF SPLIT IN THE MOISTURE
FLOW...WITH THE HEAVIEST MOISTURE TRANSPORT/HIGHEST PRECIPITABLE
WATER FOCUSING ON THE OR/CA BORDER BY FRI EVENING. THIS SOLUTION
WOULD PROBABLY AVOID MUCH IN THE WAY OF HYDROLOGIC ISSUES FOR OUR
FORECAST AREA.
ANOTHER THING TO KEEP AN EYE ON WITH FOR THE THU NIGHT/FRI SYSTEM IS
THE CASCADE SNOW POTENTIAL. IF THE FRONTAL SYSTEM OCCLUDES OVER US
IT MAY STILL BE COLD ENOUGH FOR SIGNIFICANT SNOW IN THE HIGHER
ELEVATIONS OF THE S WA/N OR CASCADES...MAINLY MT HOOD NORTHWARD.
WITH LIQUID QPF OF 1-2 INCHES...OR 12 TO 20 INCHES OF SNOW
POTENTIAL...POSSIBLE. THIS COULD PUSH THE HIGHER ELEVATIONS INTO
ADVISORY OR EVEN PERHAPS WARNING CRITERIA. SNOW LEVELS AND EXPECTED
QPF ARE STILL A LITTLE TOO UNCERTAIN TO ISSUE A WINTER STORM
WATCH...BUT WILL CONTINUE TO REEVALUATE. WEAGLEROCK
.LONG TERM...NO CHANGES...FRIDAY NIGHT THROUGH TUESDAY...
EXPECT LITTLE CHANGE IN THE OVERALL WEATHER PATTERN OVER THE EXTENDED
FCST PERIOD. A SERIES OF UPPER LEVEL TROUGHS WILL KEEP COOL AND WET
WEATHER CONTINUING THROUGH THE WEEKEND AND THE FIRST HALF OF NEXT
WEEK. A SIGNIFICANT SYSTEM LOOKS LIKE IT WILL BRING MODERATE
PRECIPITATION TO THE REGION FRI NIGHT...BUT THE LATEST MODEL CYCLE
CONTINUES TO KEEP THE HEAVIEST QPF FOCUSED OVER N CALIFORNIA AND S
OREGON. AFTER THIS FRONT PUSHES THROUGH...DO NOT CURRENTLY SEE ANY
MAJOR SYSTEMS THROUGH EARLY NEXT WEEK. BUT THERE WILL PLENTY OF
CHANCES FOR LIGHT RAIN AND MOUNTAIN SNOW. EXPECT TEMPERATURES TO RUN
ABOUT 5 TO 7 DEGREES BELOW NORMAL OVER THE LONG TERM PERIOD. PYLE
&&
.AVIATION...MIX OF MVFR AND VFR CONDITIONS CONTINUE IN SHOWERS
THROUGH THIS EVENING. EXPECT INCREASING MVFR CIGS AROUND 2500 FT AS
THE MAIN LOW MOVES ONSHORE AFTER 06Z THU...BUT MOSTLY VFR
CONDITIONS RETURN BY 14-16Z THU MORNING.
KPDX AND APPROACHES...MIX OF MVFR AND VFR CIGS AROUND 2000-2500 FT
IN SHOWERS CONTINUES THROUGH 18-20Z THIS MORNING...THEN EXPECT
MOSTLY VFR CONDITIONS. INCREASING MVFR CIGS AFTER 06-08Z THU WHEN
THE LOW PUSHES INLAND. /27
&&
.MARINE...FEW CHANGES...WEAKENING LOW PRESSURE WILL DROP SE
TOWARDS THE COLUMBIA RIVER MOUTH TODAY THEN FILL AND OPEN UP THIS
EVENING. GUSTY SE WINDS WILL BE HIGHEST OVER THE CENTRAL COAST
WATERS WHERE GUSTS MAY APPROACH 30 KT THIS EVENING WITH WHATS LEFT
OF THE ACCOMPANYING FRONT...BUT OVERALL STILL EXPECT GUSTS TO
PERSIST IN THE 20-25 KT RANGE THROUGH THU AFTERNOON. THE NEXT
SYSTEM WILL BE QUICK ON THE HEALS WITH MODERATE POTENTIAL FOR A
COASTAL JET DEVELOPING BY MIDNIGHT THU NIGHT INTO FRI AS A SYSTEM
GRAZES THE NORTHERN WATERS WITH A GALE THREAT EXTENDING SOUTH
ACROSS THE WATERS. HIGHEST SPEEDS WOULD LIKELY BE INSIDE OF 20 NM
AS A FIRST GUESS. WANT TO SEE HOW THE DETAILS PLAY OUT OVER THE
NEXT COUPLE MODEL RUNS HOWEVER. ANOTHER SIMILARLY STRONG STORM
SYSTEM LOOKS ON TAP FOR SATURDAY.
SEAS SHOULD GENERALLY REMAIN IN THE 10 TO 12 FT RANGE INTO THE
WEEKEND THOUGH A BRIEF SWELL BREAK DOWN TO 9 FT IS POSSIBLE LATER
THIS AFTERNOON. HOWEVER...INCREASING WIND WAVES LOOK TO BE ENOUGH
TO HOLD COMBINED SEAS ABOVE THE 10 FT ADVISORY THRESHOLD. DECIDED
TO PUSH THE SMALL CRAFT ADVISORY FOR SEAS OUT THROUGH THURSDAY
EVENING FOR NOW. SLIGHTLY HIGHER SEAS APPEAR PROBABLE WITH THE
SATURDAY SYSTEM. /JBONK
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM PDT
THURSDAY FOR CASCADES IN LANE COUNTY-NORTHERN OREGON
CASCADES.
WA...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM PDT
THURSDAY FOR SOUTH WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PDT THURSDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER TO FLORENCE OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT
THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER TO FLORENCE
OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM
PDT THIS AFTERNOON...THEN AGAIN FROM 11 PM THIS EVENING TO
4 AM PDT THURSDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA..
Area Forecast Discussion
National Weather Service Spokane WA
512 AM PDT WED MAR 26 2014
.SYNOPSIS...A showery and unsettled spring time weather pattern
will persist through Thursday. A few thunderstorms will also be
possible this afternoon and again on Thursday. Temperatures will
gradually cool through the rest of the week. The cooler
temperatures will allow snow to fall over the mountains and the
higher elevations of the Inland Northwest. A wetter but warmer
system will track into the region on Friday and persist into the
weekend. This will result in widespread rain and high mountain
snow.
&&
.DISCUSSION...
Today through Tonight...Todays weather will begin quiet
enough...as we are in a brief lull between yesterdays front
and a deep cold core upper level low currently poised around
47n/134w. Model guidance is in very good agreement that this
low will meander toward the coast through the day. As it
does...we expect to see slowly falling or steady 500 mb
temperatures between -27 to -30c. These values are similar to what
was experienced yesterday in the Cascades...and significantly
colder over the eastern third of Washington and the Idaho
Panhandle. So what does this mean? It suggests we will likely see
a rapid blossoming of showers during the latter half of the day in
response to daytime heating and the resultant instability. Just
about any location in the Inland NW could see some showers during
the afternoon...however whether or not it happens over any given
location is not a sure bet. Based on the positioning of the
low...about 200 miles west of Astoria by 4pm...it would place the
best chances either in the diffluent region over the Cascades or
over NE Washington and the Panhandle due to southwest orographic
ascent. While showers are likely to form this afternoon the
possibility of thunder is tougher to answer. Forcing from the
upper level low will likely remain well west of our forecast area
today so the impetus for thunder will likely have to rely on
diurnal heating combining with the greatest potential instability.
Model soundings and SREF data suggest the best chances will be
reserved for the SE corner of Washington and the southern third of
the Idaho Panhandle. There would also be a small chance over the
Cascades....generally south of Lake Chelan.
For tonight...the threat of thunder will wane markedly with the
loss of diurnal heating...however the low will continue its march
to the east. Just where it ends up by morning is uncertain...as
model guidance places the low as far south as Portland or as far
north as the southern tip of Vancouver Island. Nonetheless the
approach of the low should continue the threat of showers through
the nighttime hours as broad ascent feasts on good mid-level lapse
rates. The chances for showers will steadily increase from the
southwest corner of our forecast area during the evening and
spread NE overnight as a wraparound band of precipitation forms in
addition to the numerous showers. Some model solutions are
predicting moderate amounts of precipitation from this wraparound
band...while snow levels could drop as low as 2500-3000 ft near
the Canadian border. This suggests light to moderate snow could
impact some of the mountain passes as well as a few of the higher
valleys late tonight and continuing into Thursday morning. fx
Thursday through Sunday night...The closed low off the Washington
coast today will move through the Inland Northwest as an open
wave on Thursday. This will lead to an increase in showers
especially over the high terrain of Eastern Washington and North
Idaho where low level upslope flow will enhance shower activity.
As the wave moves into Montana by late Thursday afternoon...sun
breaks on the back side of this wave over Eastern Washington and
North Idaho combined with colder air aloft with 500mb temps near
-29C will destabilize the atmosphere with GFS and NAM stability
parameters showing the potential for a few lightning strikes with
uncapped CAPE values of 200-500 J/KG. Snow levels of 3000-4000
feet in the mountains could also bring light to moderate snow
accumulations. Showers will linger into Thursday evening then
become confined mainly to the Idaho Panhandle overnight as a brief
short wave ridge noses into Central and Eastern Washington ahead
of the next system.
Another low pressure system will set up between 130-140W off
Vancouver Island on Friday. A warm front will move through
bringing widespread rain and mountain snow with snow levels in the
afternoon rising to 4000-5000 feet...increasing further to
4500-6000 feet Friday evening with the lowest values in the
Cascades and northern mountains. The rising snow levels should
limit snow impacts over the mountain passes. The cold front
quickly follows overnight Friday into Saturday. As the upper jet
sags back south of the area, precipitation will once again turn
showery over the weekend with the greatest areal coverage of
showers during the afternoon/early evening hours when the
atmosphere becomes increasingly unstable. Stability parameters
again show a threat for isolated thunderstorms both Saturday and
Sunday especially over the higher terrain of northeast Washington
and North Idaho. Snow levels will range from 4000-5000 feet on
Saturday falling to 3000-4500 feet Sunday. This will bring a
renewed threat for mountain snow accumulations over the passes but
nothing significant is expected at this time with mainly light
accumulations expected. JW
Monday through Wednesday: A low of the WA coast will bring an
active weather pattern for this period. Model agreement is fairly
low with the location of the most precip. The GFS is keeping the
moisture South of the region while the ECMWF is bringing the
moisture through the region. The bulk of the moisture is expected
to impact the Cascades and isolated showers throughout the Inland
Northwest. The timing of the system is expected to begin the
Cascades by Monday night and continue through the rest of the
region on Tuesday and early Wednesday. The temperatures are
expected to be near the normals for this time of year. /JDC
&&
.AVIATION...
12Z TAFS: VFR conditions are expected at all sites through most of
the period. The exception will revolve around an MVFR cloud deck
impacting the COE area...and likely just east of SFF. No idea how
extensive the deck is since its totally obscured by high clouds on
satellite. Consequently we utilized RAP model data which shows
drier air moving in from the west by 17z as well as conditional
climatology. Anyway confidence is not high. Otherwise the main
weather feature for this afternoon and early evening will be a
rapid destabilization of the atmosphere and a growing possibility
of showers. Although the instability will not be that
impressive...there will be a small chance of thunderstorms over SE
WA which could be near LWS and perhaps PUW between 21z-02z. MWH
and EAT won`t see much of a chance today...but should see a
growing chance overnight as the atmosphere destabilizes even
further with the approach of a cold upper level low. The low will
head toward the WA/ID border after 06z...which will result in
numerous showers and a band of wraparound precipitation. THERE`S a
small chance of MVFR cigs developing near this band but we did not
have enough confidence to put in prevailing wording. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 37 48 33 47 38 / 40 70 80 40 100 80
Coeur d`Alene 51 34 45 33 47 36 / 50 70 90 60 90 90
Pullman 52 38 47 34 49 39 / 40 70 70 40 90 100
Lewiston 57 41 52 36 55 44 / 40 70 70 40 70 80
Colville 56 32 51 34 51 35 / 50 60 70 30 100 80
Sandpoint 48 32 44 34 45 34 / 60 60 90 60 90 90
Kellogg 48 34 44 33 46 35 / 50 70 100 80 90 100
Moses Lake 59 39 57 38 55 40 / 20 40 20 20 80 40
Wenatchee 58 38 56 37 53 36 / 30 50 20 20 80 50
Omak 59 34 56 33 51 34 / 30 50 30 20 70 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 PM CDT THU MAR 27 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 355 PM CDT THU MAR 27 2014
AT 3 PM...A 992 MB SURFACE LOW WAS CENTERED OF THE SOUTHWEST
CORNER OF IOWA. THE LATEST MSAS SHOWS 3 HOUR HEIGHT FALLS OF 3
MILLIBARS ACROSS EASTERN IOWA...SOUTHERN WISCONSIN...AND NORTHERN
ILLINOIS. AS RESULT...EXPECT THE LOW TO CONTINUE TO TRACK
NORTHEAST ACROSS IOWA LATE THIS AFTERNOON AND EARLY EARLY EVENING.
MODERATE TO STRONG 850 MB MOISTURE TRANSPORT MOVES INTO NORTHEAST
IOWA...AND SOUTHWEST AND CENTRAL WISCONSIN BETWEEN 27.21Z AND
28.03Z. DUE TO THIS...INCREASED THE PRECIPITATION TOTALS INTO THE
0.35 TO 0.75 INCH RANGE.
IN ADDITION TO THIS...THE MOST UNSTABLE CAPES CLIMB UP TO
300 J/KG ACROSS PARTS OF NORTHEAST IOWA...SOUTHEAST
MINNESOTA...AND SOUTHWEST AND CENTRAL WISCONSIN. THERE HAS ALREADY
BEEN A FEW ISOLATED REPORTS OF LIGHTNING ALONG AND SOUTH OF
INTERSTATE 90 THIS AFTERNOON. WITH THE CAPES A BIT FURTHER NORTH
AND WEST...EXPANDED THE CHANCE OF THUNDERSTORMS MORE INTO
NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND AS FAR AS NORTH OF
INTERSTATE 90 CORRIDOR THROUGH 28.03Z. WITH THE 0-3 KM AND 0-6 KM
SHEAR LESS THAN 30 KNOTS...NOT EXPECTING ANYTHING SEVERE.
MEANWHILE ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL
WISCONSIN...COLD AIR ADVECTION DEVELOPS ACROSS SOUTHEAST
MINNESOTA AND NORTH CENTRAL WISCONSIN. THE NAM IS THE STRONGEST
AND FASTEST WITH THIS COLD AIR ADVECTION. AS A RESULT...IT
PRODUCES MUCH MORE SNOW ACROSS SOUTHEAST MINNESOTA /UP TO 2.5
INCHES IN COBB/ TONIGHT. HOWEVER THE 18Z AMDAR SOUNDINGS SHOW THAT
IT IS A BIT TOO COLD AND MUCH CLOSER TO THE RAP AND GFS. AS A
RESULT...TRENDED THE SWITCH OVER FROM RAIN TO SNOW A BIT LATER
THAN PREVIOUSLY FORECAST. IT LOOKS LIKE THIS WILL OCCUR...NORTH
OF INTERSTATE 94 BETWEEN 27.21Z AND 28.00Z...WEST OF MISSISSIPPI
RIVER BETWEEN 28.00Z AND 28.03Z...AND ACROSS THE REMAINDER OF THE
AREA BETWEEN 28.04Z AND 28.08Z. SOUTHEAST MINNESOTA WILL SEE UP TO
AN INCH...AND AROUND 3 INCHES NORTH OF WISCONSIN 29 IN NORTH
CENTRAL WISCONSIN. ELSEWHERE VERY LITTLE...IF ANY...SNOW IS
EXPECTED.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 PM CDT THU MAR 27 2014
ON SUNDAY...A TIGHT PRESSURE GRADIENT DEVELOPS ALONG AND SOUTH OF
THE INTERSTATE 90 CORRIDOR AHEAD OF A DEEPENING LOW OVER THE
NORTHERN PLAINS. THIS TIGHT PRESSURE GRADIENT WILL ALLOW THE
SUSTAINED SOUTH WINDS TO CLIMB INTO THE 15 TO 25 KNOT RANGE AND
THE WINDS WILL GUST UP TO 35 MPH. AT THE SAME...THE 850 MB
TEMPERATURES WILL CLIMB INTO THE 10 TO 14C RANGE ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA. BUFKIT SOUNDING SHOW THAT WE
WILL NOT QUITE MIX UP TO THIS LEVEL...BUT WE WILL MIX UP INTO THE
900 TO 875 MB LAYER...AND THIS WILL ALLOW TEMPERATURES TO CLIMB
INTO THE LOW AND MID 50S NORTH OF INTERSTATE 94...AND AROUND 60
ACROSS THE REMAINDER OF THE AREA.
FROM SUNDAY NIGHT INTO MONDAY NIGHT...THE MODELS CONTINUE TO SHOW
THAT A NEGATIVELY TILTED SHORT WAVE TROUGH WILL MOVE THROUGH THE
FORECAST AREA. TEMPERATURES ALOFT ARE WARM ENOUGH THAT MUCH OF THE
PRECIPITATION WILL FALL MAINLY IN THE FORM OF RAIN. WHILE THE
0-6 KM SHEAR ARE GREATER THAN 35 KNOTS...THERE IS VERY LITTLE
CAPE ACROSS THE REGION...SO THERE IS NOT ANY THREAT FOR ANY SEVERE
WEATHER.
BEYOND THIS TIME PERIOD...THE 27.00Z MODELS HAVE DIFFERING
OPINIONS ON HOW FAR NORTH A LOW WILL TRACK THROUGH NORTHERN AND
MID MISSISSIPPI RIVER VALLEY. THE ECMWF IS MUCH FURTHER NORTH THAN
THE GFS. WITH SUCH DIVERSE SOLUTIONS...JUST STAYED WITH THE MODEL
CONSENSUS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 605 PM CDT THU MAR 27 2014
SURFACE LOW PRESSURE IS MOVING NORTHEAST ACROSS CENTRAL IOWA LATE
THIS AFTERNOON. BROAD AREA OF PRECIPITATION NORTH OF THE LOW WITH
TEMPERATURES WARM ENOUGH FOR ALL RAIN AT BOTH TAF SITES SO FAR. AS
THE LOW MOVES PAST EARLY THIS EVENING...THE COLDER AIR WILL START
TO FILTER IN FROM THE NORTHWEST. BOTH THE 27.18Z NAM AND 27.21Z
RAP BUFKIT SOUNDING SHOW THE POTENTIAL FOR A CHANGE OVER TO ALL
SNOW AT KRST. HOWEVER...BOTH MODELS WOULD HAVE THIS HAPPENING
RIGHT AROUND 00Z...WHICH BASED ON CURRENT OBSERVATIONS WOULD BE
TOO SOON. WILL SHOW THE CHANGE OVER TO SNOW OCCURRING AROUND 02Z.
AT KLSE...THERE ALSO LOOKS TO BE THE POTENTIAL FOR A CHANGE OVER
TO SNOW OR FOR SNOW TO MIX WITH THE RAIN...BUT ALSO A CONCERN AS
TO WHETHER ICE WILL BE IN THE CLOUDS. PLAN TO HANDLE THIS BY
STAYING PREDOMINANTLY WITH RAIN BUT SHOW THE POSSIBILITY OF A
RAIN/SNOW MIX LATE IN THE EVENING. AS THE PRECIPITATION
ENDS...LOOK FOR THE NORTHWEST WINDS TO INCREASE WITH SUSTAINED
SPEEDS OF 15 TO 20 KNOTS AND GUSTS OF 25 TO 30 KNOTS. ONCE THIS
OCCURS...SHOULD SEE THE VISIBILITY IMPROVE TO VFR WITH THE
CEILINGS STARTING TO RISE TOWARD MVFR. IR SATELLITE SHOWING MVFR
CLOUDS EXTENDING WELL BEHIND THE SURFACE LOW ACROSS NEBRASKA AND
THE NAM DOES NOT CLEAR THE 850 MB MOISTURE FIELD WITH THESE CLOUDS
UNTIL AFTER 12Z. THUS...PUSHED THE SCATTERING OF THE CLOUDS BACK
UNTIL MID MORNING BUT CONCERNED THAT BOTH THE RAP AND NAM KEEP THE
925MB MOISTURE LEVELS HIGH THROUGH MUCH OF THE DAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
346 AM EDT FRI MAR 28 2014
.SYNOPSIS...
MOISTURE WILL BE HIGH AHEAD OF A SLOW MOVING FRONTAL SYSTEM. THE
FRONT WILL MOVE THROUGH THE FORECAST AREA LATE SATURDAY. HIGH
PRESSURE AND DRIER CONDITIONS WILL PREVAIL SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...A MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SHOULD HELP SUPPORT
SHOWERS TODAY. THE NAM AND GFS MOS PLUS RADAR TRENDS SUPPORT HIGH
POPS. BASED TIMING ON RADAR TRENDS AND THE LATEST HRRR. CLOUDINESS
AND SHOWERS SHOULD LIMIT INSTABILITY. THE NAM INDICATES JUST WEAK
INSTABILITY. THE HRRR AND SATELLITE TRENDS SUPPORT KEEPING THE
STRONGER CONVECTION SOUTH OF THE FORECAST AREA. EXPECT MAINLY
SHOWERS INSTEAD OF THUNDERSTORMS. USED THE COOLER TEMPERATURE
GUIDANCE BECAUSE OF CLOUDINESS.
TONIGHT...THE MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SUPPORT
CONTINUED HIGH POPS TONIGHT. COVERAGE MAY INCREASE TOWARD MORNING
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. COOLING ALOFT ASSOCIATED
WITH THE UPPER TROUGH SUPPORTS A HIGHER CHANCE OF THUNDERSTORMS
TOWARD MORNING. SHEAR WILL BE ON THE INCREASE INDICATING WELL-
ORGANIZED THUNDERSTORMS MAY OCCUR BUT THE NAM SUGGESTS ANY
SURFACE-BASED INSTABILITY WILL REMAIN WEAK THROUGH THE NIGHT. THE
DIURNAL TIMING SHOULD ALSO HELP LIMIT INSTABILITY. THEREFORE...THE
RISK OF SEVERE THUNDERSTORMS APPEARS LOW AT THIS TIME. THE WARMER
TEMPERATURE GUIDANCE APPEARS BETTER BECAUSE OF CLOUDINESS.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
SATURDAY...MOISTURE SHOULD BE HIGH AHEAD OF THE COLD FRONT
SATURDAY. THE NAM INDICATES THE DEEPEST MOISTURE EARLY SATURDAY.
THE GFS AND ECMWF SHOW THE DEEPEST MOISTURE AROUND THE MIDDLE OF
THE DAY AHEAD OF THE COLD FRONT. THE MODELS WERE MORE CONSISTENT
WITH COLD FRONTAL PASSAGE LATE IN THE DAY OR EVENING. WE
MAINTAINED LIKELY POPS DURING MUCH OF THE DAY WITH THE TIMING
DIFFICULT BECAUSE ISENTROPIC LIFT APPEARS GREATER IN THE
MORNING...BUT CONVERGENCE AHEAD OF THE COLD FRONT SHOULD BE HIGHER
DURING THE AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE H85
WINDS OF 35 TO 40 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S NEAR
-3 DURING THE AFTERNOON. THERE WILL BE A THREAT OF SEVERE
THUNDERSTORMS BECAUSE OF THIS SHEAR AND INSTABILITY. ANY LINGERING SHOWERS
AND THUNDERSTORMS SHOULD END FROM WEST TO EAST SATURDAY EVENING
AS DRYING BECOMES DOMINATE BEHIND THE COLD FRONT. WE USED THE
GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE
DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE
IN THE PERIOD AHEAD OF A COLD FRONT. THE COOLEST NIGHT SHOULD BE
SUNDAY NIGHT. STRONG NOCTURNAL COOLING SHOULD OCCUR WITH DRY HIGH
PRESSURE OVERHEAD AND LIGHT WINDS. AN AVERAGE OF THE GFS...ECMWF
AND EKD MOS SUPPORTS LOWS MAINLY IN THE UPPER 30S. FROST WILL BE
POSSIBLE MAINLY IN THE NORMALLY COLDER LOCATIONS. WARMER
TEMPERATURES SHOULD OCCUR BEGINNING MONDAY AS THE HIGH SHIFTS
EASTWARD AND THE AIR MASS CONTINUES TO MODIFY. THE GFS...ECMWF...
AND EKD MOS SUPPORT HIGHS IN THE UPPER 70S TO AROUND 80 TUESDAY
THROUGH THURSDAY.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS FORECAST FOR THE NEXT SEVERAL HOURS. AS LOW-LEVEL
MOISTURE INCREASES LATE TONIGHT...LAMP GUIDANCE AND MAV/MET MOS
SUGGESTING MVFR CIGS DEVELOPING DURING THE PRE-DAWN HOURS. THERE IS
THE POSSIBILITY OF IFR CEILINGS AROUND SUNRISE...BUT CONFIDENCE TOO
LOW TO INCLUDE. SHOULD SEE AT LEAST SCATTERED SHOWERS DEVELOPING BY
MIDDAY...BUT BETTER CHANCE DURING THE AFTERNOON INTO THE EVENING
HOURS. LAMP GUIDANCE INDICATE MVFR CIGS CONTINUING THROUGH THE END
OF THE TAF PERIOD...WHILE NAM INDICATES A PERIOD OF CIGS ABOVE 3000
FEET DURING THE AFTERNOON HOURS. WILL LEAN A BIT MORE TOWARDS THE
MORE PESSIMISTIC LAMP FORECAST.
INCREASING SOUTHERLY LOW LEVEL JET OVERNIGHT. LATEST CAE VWP SHOWING
40-45 KT WIND AROUND 2 KFT EARLY THIS MORNING. WILL MENTION LLWS FOR
ALL TAF SITES UNTIL AROUND 15Z THIS MORNING.
EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS EXPECTED FRIDAY
NIGHT INTO SATURDAY AHEAD OF COLD FRONT THAT WILL CROSS THE AREA LATE
SATURDAY AFTERNOON. BREEZY CONDITIONS IN THE WAKE OF THE FRONT
SATURDAY NIGHT INTO SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
315 AM CDT FRI MAR 28 2014
.DISCUSSION...
801 PM CDT
ONLY SOME MINOR TWEAKS HAVE BEEN MADE TO THE GOING FORECAST FOR
THE REST OF TONIGHT INTO EARLY FRIDAY MORNING. THE PRIMARY TIME
FOR RAIN SHOWERS WITH SOME SCATTERED THUNDERSTORMS REMAINS NOW
THROUGH MIDNIGHT.
A WELL-DEFINED SHORT-WAVE TROUGH FROM MN INTO CENTRAL MN THIS
EARLY EVE IS ADVANCING EAST NORTHEASTWARD. THE 00Z RAOB SOUNDINGS AND
PROFILERS INDICATED A 55-60 KT LOW LEVEL JET AHEAD OF THIS INTO
THE FORECAST AREA. SOME OF THE BETTER DEEPER MOISTURE RETURN THAT
COULD BE ASSOCIATED WITH THIS IS LIKELY BEING ROBBED BY QUITE A
BIT OF CONVECTION ACROSS THE LOWER MISSISSIPPI VALLEY...AS WELL
AS THE SUBTROPICAL JET REMAINING WELL SOUTH.
NONETHELESS...NORTH-TO-SOUTH ARCS OF CONVECTION AHEAD OF THE MAIN
VORT MAX CONTINUE TO PROGRESS ACROSS NORTHERN AND WESTERN IL AND
SHOULD CONTINUE AT A SIMILAR COVERAGE INTO THE CHICAGO AREA. THE
DEGREE OF LIGHTNING HAS FLUCTUATED SOME BUT CONFINED TO WITHIN A
NARROW AXIS OF DWINDLING MUCAPE AHEAD OF THE SYSTEM. SOME BRIEF
DOWNPOURS AND MAYBE A FEW BOOSTS TO THE ALREADY HIGH SYNOPTIC
GUSTS...BUT ALL-IN-ALL JUST SOME GARDEN VARIETY SCATTERED STORMS
AS EXPECTED. AS A DRY CONVEYOR BELT AS SEEN ON WATER VAPOR AND
UPPER AIR RAOBS IN KS ROTATES INTO THE FORECAST AREA EARLY
OVERNIGHT THERE SHOULD STILL BE A LULL IN ACTIVITY...WITH SOME
UPTICK EXPECTED BETWEEN 3-8 AM NORTH OF I-80 AS THE CENTER OF THE
WAVE PASSES AND TAPS SOME WRAPAROUND MOISTURE. IF THE LOW-LEVELS
COOL ENOUGH...SOME WET SNOW IS POSSIBLE INTO THE EARLY PART OF THE
MORNING RUSH. WITH SURFACE TEMPS SEVERAL DEGREES ABOVE FREEZING
AND ROADS ALREADY WET...WOULD NOT SEEM LIKE MUCH FOR IMPACTS.
TEMPERATURES WILL CONTINUE TO HOLD STEADY IN THE STRONG SOUTHERLY
FLOW WITH ADVECTION AND HIGHER DEW POINT AIR HELPING TO MAINTAIN
TEMPERATURES IN THE UPPER 40S TO MID 50S FAR SOUTH. AS THE FRONT
PASSES DURING THE EARLY OVERNIGHT...READINGS SHOULD STEADILY HEAD
DOWNWARD WITH GOING FORECAST HOURLY TEMPS AND LOWS LOOKING ON
TRACK.
MTF
//PREV DISCUSSION...
300 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM POTENTIAL THIS
EVENING...MIX OF RAIN/SNOW EARLY FRIDAY MORNING...LAKE BREEZES
FRIDAY AND SATURDAY...CHANCE OF RAIN/SNOW FRIDAY NIGHT SOUTH...
TEMPS AROUND 60 SUNDAY/MONDAY AND ANOTHER CHANCE OF THUNDERSTORMS
MONDAY AFTERNOON/EVENING.
TEMPS HAVE STRUGGLED INTO THE LOWER/MID 40S THIS AFTERNOON WITH
BREEZY SOUTHERLY WINDS...WHICH HAVE BEEN LOWER THAN EXPECTED.
CURRENT SHOWER ACTIVITY WILL MOVE NORTHEAST OF THE CWA IN THE NEXT
1-2 HOURS WITH A 2-4 HOUR DRY PERIOD INTO EARLY THIS EVENING. LOW
PRESSURE OVER SOUTHWEST IOWA WILL LIFT NORTHEAST ACROSS SOUTHERN
WISCONSIN THIS EVENING WITH A TRAILING COLD FRONT MOVING ACROSS
THE AREA THIS EVENING. LINE OF THUNDERSTORMS HAS DEVELOPED AHEAD
OF THIS COLD FRONT ACROSS EASTERN KANSAS AND WESTERN MISSOURI.
THIS ACTIVITY WILL ACCOMPANY THE FRONT THIS EVENING THOUGH SHORT
TERM/HIGH RES GUIDANCE DIFFERS ON THUNDER COVERAGE/INTENSITY
LATER THIS EVENING. POSSIBLE THAT SOME OF THIS WILL LIFT NORTH
WITH THE LOW AND THE MAIN LINE MOVES EAST ACROSS CENTRAL IL. THUS
HAVE MAINTAINED CHANCE THUNDER MENTION WHICH MAY NEED TO BE
INCREASED AS THE LINE APPROACHES. THUNDER POTENTIAL/DURATION WILL
ONLY LAST AN HOUR OR TWO. PRECIP EXPECTED TO END BEHIND THE FRONT
BUT THEN WRAP AROUND PRECIP ON THE BACK SIDE OF THE LOW WILL
SPREAD BACK ACROSS NORTHERN ILLINOIS OVERNIGHT PERHAPS LINGERING
INTO EARLY FRIDAY MORNING. AS COLDER AIR SPREADS BACK ACROSS THE
REGION...PRECIP WILL CHANGE TO A MIX OF RAIN/SNOW WITH PERHAPS
PRECIP BECOMING ALL SNOW BEFORE ENDING ACROSS THE FAR NORTH. WHILE
NO ACCUMULATION IS IN THE FORECAST...IF PRECIP WERE TO CHANGE OVER
TO SNOW SOONER...THEN ITS POSSIBLE THERE COULD BE SOME MINOR SNOW
ACCUMULATIONS...AGAIN MAINLY ACROSS THE FAR NORTHERN CWA.
TEMPERATURES WILL CONTINUE TO CLIMB THIS AFTERNOON INTO THIS
EVENING WITH CALENDAR DAY HIGHS LIKELY TO OCCUR IN THE MID/LATE
EVENING AHEAD OF THE FRONT. NOT OUT OF THE QUESTION FOR SOME LOWER
50S TO MAKE IT AS FAR NORTH AS THE CHICAGO METRO AREA WITH STRONG
SOUTHERLY FLOW...BUT THESE TEMPS WILL BE SHORT-LIVED. AS NOTED...
WINDS HAVE NOT BEEN AS STRONG AS ORIGINALLY EXPECTED. HOWEVER...
AS THE LOW APPROACHES AND ONGOING SHOWER ACTIVITY ENDS...EXPECT
WINDS/GUSTS TO INCREASE THROUGH THE LATE AFTERNOON AND INTO THE
EVENING WITH GUSTS UP TO 40 MPH STILL POSSIBLE...PERHAPS A BIT
STRONGER JUST AHEAD AND JUST BEHIND THE FRONT.
ONCE THE PRECIP ENDS FRIDAY MORNING...NORTHERLY WINDS WILL TURN
MORE NORTHEAST AS HIGH PRESSURE BUILDS ACROSS THE UPPER MIDWEST.
GUIDANCE SUGGESTS A RATHER STRONG LAKE BREEZE/FRONT MOVING IN FROM
THE LAKE IN THE AFTERNOON AND HAVE ATTEMPTED TO ACCOUNT FOR THAT
WITH FALLING TEMPS IN THE AFTERNOON AS WINDS SHIFT NORTHEAST.
AHEAD OF THAT LAKE BREEZE...HIGHS IN THE LOWER/MID 40S LOOK ON
TRACK WITH UPPER 40S/NEAR 50 FURTHER INLAND...WESTERN/SOUTHERN CWA.
NOT MUCH CONFIDENCE REGARDING THE NEXT SYSTEM MOVING THROUGH THE
OHIO VALLEY FRIDAY NIGHT INTO SATURDAY MORNING. MODELS HAVE
TRENDED A BIT FURTHER SOUTHEAST AND PRECIP COULD END UP STAYING
MAINLY SOUTH OF THE AREA. ONLY CHANGE TO THIS TIME PERIOD WAS TO
SHIFT THE PRECIP EDGE A BIT FURTHER SOUTH TO THE I-80 CORRIDOR.
PRECIP TYPE ALSO REMAINS PROBLEMATIC...ASSUMING IT PRECIPITATES
THIS FAR NORTH WITH THE POTENTIAL FOR SOME FREEZING RAIN IF
SURFACE TEMPS WERE TO DROP BELOW FREEZING BY SATURDAY MORNING.
WITH THE EXCEPTION OF ANY LINGERING PRECIP SATURDAY MORNING OVER
THE FAR SOUTHEAST...THE WEEKEND STILL ON TRACK TO BE DRY THOUGH
SATURDAY WILL BE CHILLY OVER MUCH OF THE METRO AREA WITH A LAKE
BREEZE KEEPING THE LAKESHORE AREAS ONLY IN THE 30S. FLOW QUICKLY
SHIFTS SOUTHERLY SATURDAY NIGHT INTO SUNDAY WITH BREEZY SOUTHERLY
WINDS PUSHING TEMPS INTO THE UPPER 50S/LOWER 60S. EXPECT SOME SORT
OF SOUTHEASTERLY COMPONENT ALONG THE IL SHORE...SO LAKESHORE AREAS
FROM DOWNTOWN NORTH COULD BE CONSIDERABLY COLDER.
MODELS CONTINUE TO SLOW THE NEXT LOW MOVING ACROSS THE MIDWEST ON
MONDAY...ONLY TO WESTERN WISCONSIN BY MONDAY EVENING. THIS SHOULD
PROVIDE STRONG SOUTHWESTERLY WINDS OVER THE ENTIRE AREA HELPING TO
PUSH TEMPS INTO THE LOWER 60S OVER MUCH OF THE AREA. HAVE REMOVED
PRECIP MONDAY MORNING EXCEPT THE FAR NORTHWEST AND ADDED THUNDER
BACK TO THE FORECAST FOR THE AFTERNOON. TIMING STILL UNCERTAIN
FROM THIS DISTANCE BUT WITH A COLD FRONT EXPECT TO MOVE ACROSS THE
AREA EITHER LATE MONDAY AFTERNOON OR MONDAY EVENING...THUNDER
LOOKS REASONABLE.
PROGRESSIVE PATTERN CONTINUES WITH ANOTHER STORM SYSTEM LIFTING
NORTHEAST ACROSS THE OHIO VALLEY AND SOUTHERN LAKES REGION TUESDAY
NIGHT THROUGH THURSDAY. MODEL CONSENSUS IS TO KEEP MUCH OF THE
AREA ON THE NORTHERN AND COLDER SIDE OF THIS SYSTEM MAKING PRECIP
TYPE A LITTLE TRICKY. HAVE STAYED RAIN DURING THE DAY WITH A MIX
AT NIGHT MAINLY NORTH...BUT CURRENT THERMAL PROFILES WOULD
SUGGEST MAINLY RAIN THROUGH THE EVENT. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* STRONG AND GUSTY SOUTH WINDS WILL RELAX AND TURN MORE WESTERLY.
* MVFR CIGS WILL PERSIST THROUGH THE MORNING...AND POSSIBLY DROP
TO IFR WITH SECOND WAVE OF RAIN OR LIGHT SNOW. VFR THIS AFTERNOON.
LENNING
//DISCUSSION...UPDATED 06Z...
A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THROUGH LOWER
MICHIGAN. AS THE LOW MOVES OUT...WINDS WILL VEER FROM SOUTH TO
WEST OVERNIGHT AND THEN AROUND TO NORTHEAST BY AFTERNOON.
CEILINGS GENERALLY ARE STAYING AT MVFR FOR THE TIME BEING...BUT
RAIN SHOWERS WRAPPING AROUND THE LOW MAY BRIEFLY DROP CIGS TO IFR
TOWARD MORNING AS THEY PASS THROUGH. SKIES LIKELY SCATTER OUT
DURING THE LATE MORNING OR AFTERNOON AS DRIER AIR MOVES IN AHEAD
OF AN APPROACHING HIGH.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE ON TIMING OF WIND DIRECTIONAL CHANGES.
* MEDIUM TO HIGH CONFIDENCE ON CEILING TRENDS...THOUGH LOWER
CONFIDENCE REGARDING IFR TOWARD MORNING.
LENNING
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...VFR. NORTHEAST WINDS.
SUNDAY...VFR. SOUTH WINDS.
MONDAY...CHANCE OF SHRA/TSRA LATE. MODERATE-STRONG SOUTH WINDS.
TUESDAY...VFR PROBABLE. WEST WINDS.
WEDNESDAY...CHANCE OF RAIN AND IFR/MVFR CIGS. NORTHEAST WINDS.
IZZI
&&
.MARINE...
307 AM CDT
A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THIS MORNING
ACROSS LOWER MICHIGAN AND LAKE HURON. NORTHWEST TO NORTH GALES
WILL EASE QUICKLY THIS MORNING AS THE LOW PULLS AWAY AND THE
PRESSURE GRADIENT WEAKENS. A RIDGE WILL CROSS THE LAKE ON SATURDAY
BEFORE THE NEXT LOW PRESSURE SYSTEM STARTS TO APPROACH OUT OF THE
CENTRAL PLAINS. ALTHOUGH THIS LOW DOES NOT REACH THE LAKE UNTIL
TUESDAY...SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL DEVELOP BY
EARLY SUNDAY. A PERIOD OF GALES IS AGAIN POSSIBLE LATE MONDAY
INTO TUESDAY...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE
LAKE...AS THE LOW MOVES THROUGH.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 4
AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
313 AM CDT Fri Mar 28 2014
.DISCUSSION...
ISSUED 313 AM CDT Fri Mar 28 2014
SHORT TERM...Today through Sunday
Main forecast challenge in the immediate short-term will be timing
the departure of low clouds today. 07z/2am surface analysis shows
low pressure over southern Lake Michigan with cold front trailing
southward along the I-57 corridor. Extensive area of wrap-around
cloud cover is noted on IR satellite imagery blanketing Iowa,
northern Missouri, and western Illinois. With low-level flow
becoming northwesterly, these clouds will spill across central
Illinois early this morning. All model guidance suggests an
overcast start to the day, but how quickly the clouds clear out
remains in question. NAM forecast soundings indicate clouds will
mix out/dissipate between 15z and 18z. Latest HRRR hints at this
as well, although the process may be slower than the NAM
advertises. Given subsidence behind departing upper short-wave and
late March sun working on the low clouds, think skies will
temporarily clear around midday into the early afternoon. After
that, high clouds will quickly begin to increase ahead of the next
approaching system by mid to late afternoon.
Next forecast concern revolves around low pressure expected to
track from Texas into the Tennessee River Valley tonight. Models
have been having difficulty resolving how far north associated
precip will spread. 00z Mar 28 suite is still in disagreement,
with the GFS being the most aggressive in bringing precip furthest
north. Since GFS is often too bullish with light QPF events and
airmass will be drying today, think the NAM has a more realistic
handle on the situation. As such, will keep locations along and
north of a Jacksonville to Bloomington line dry tonight. Best rain
chances will be focused along/south of I-70 in closer proximity to
the low track, with POPs steadily decreasing further northwest.
Despite overnight lows in the middle to upper 30s, NAM forecast
soundings remain warm enough for rain. If colder/further north GFS
verifies, a rain/snow mix may be possible along the northern
fringe of the precip area. Will leave mention of mix out of the
forecast due to skepticism about the GFS QPF field.
After a few lingering showers across the far E/SE KILX CWA
Saturday morning, dry and warmer weather will be the rule this
weekend. As southerly winds develop, high temperatures will climb
into the lower to middle 60s by Sunday.
LONG TERM...Monday through Thursday
Models are still advertising cold frontal passage late Monday,
although amount of available moisture appears to be quite limited.
GFS surface dewpoints are initially around 40 degrees Monday
morning and only climb to the upper 40s to near 50 by late
afternoon. Despite decent upper dynamics associated with vigorous
short-wave, lack of deep moisture return from the Gulf will limit
convective potential. As a result, will only carry low chance for
showers on Monday. Slightly cooler and drier weather will settle
into the region behind the departing front on Tuesday before
another system comes into the picture by mid-week. There are still
some key timing differences with this feature: however, all models
agree that it will have much more moisture to work with. With
short-wave crossing the Rockies into the central CONUS, surface
low pressure is expected to track from eastern Colorado on
Tuesday to the southern Great Lakes by Thursday night. Initial
surge of WAA clouds/precip will arrive Tuesday night into
Wednesday: however, with central Illinois remaining in the cool
sector, very little thunder is expected. Once warm front lifts
northward into the area and low pressure approaches from the
southwest, showers and thunderstorms will become more prevalent
Wednesday night into Thursday.
Barnes
&&
.AVIATION...
ISSUED 1153 PM CDT Thu Mar 27 2014
Band of storms has now passed east of KCMI. Cold front now
approaching KPIA with a wind shift from 200-230 to 260-290. Winds
should remain gusty until the surface low over southwest Wisconsin
pushes into the Great lakes toward 12z.
Low clouds are wrapping around the system and are moving into
KPIA attm and should push into KBMI and KSPI by TAF valid time and
swing into KDEC and KCMI shortly after, Cigs are pretty uniform
low MVFR or high VFR. Since low is pulling away will go with Cigs
in the MVFR range for the most part through mid-morning.
Wave is expected to move northeastward along the front through the
Tennessee Valley. Some question as to how far to the northwest
moisture will be able to extend. Any precip would likely be after
06z. However, VFR Cigs are likely by late afternoon. Although CIGs
may drop into MVFR by 06z at KSPI and KDEC, given the uncertianty
in the extent of moisture will keep things VFR for now.
Barker
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
257 AM CDT Fri Mar 28 2014
.SHORT TERM: (Through Sunday)
Issued at 255 AM CDT Fri Mar 28 2014
Surface low moving northeast across Lake Michigan this morning with
the trailing cold front about to exit the eastern CWA. Large area of
"wrap around" clouds affecting the northern half of the CWA this
morning will continue to move east and scatter with strong late
March insolation. Clouds will be on the increase again by this
afternoon as the next shortwave trof currently crossing the Rockies
digs toward the Midwest. Model guidance in good agreement that
surface low pressure will develop in eastern TX and move northeast
into TN by Saturday morning. Deepening mid/upper level trof will
cause rain to develop and increase from the southwest late this
afternoon, covering the southeastern half of the CWA this evening.
Greatest QPF (as much as a half inch) look to remain across the
eastern Ozarks, southeast MO and southern IL, with lighter amounts
of a tenth of an inch or less up to St. Louis and south central IL.
Trof will quickly move east of the area by Saturday morning with
seasonal temperatures and dry conditions expected as a surface ridge
builds into the Middle Mississippi River Valley from the Plains.
500mb heights quickly rise and return surface flow ensues on Sunday
in the wake of the surface ridge. Temperatures expected to jump well
above normal and have forecast highs a few degrees above the warmest
guidance given favorable synoptic pattern.
CVKING
.LONG TERM: (Sunday Night through Thursday)
Issued at 255 AM CDT Fri Mar 28 2014
Active weather pattern expected next week with a cold front moving
across the region on Sunday night/Monday morning providing a chance
of showers, with a larger synoptic system affecting the region
Tuesday night through at least Thursday morning. Temperatures will
be cooler than average in the wake of the cold front on Tuesday, but
moderation is expected as early as Wednesday as a warm front is
advertised to develop and move north into the Midwest. Models
advertising some healthy QPF with this system, which is welcome news
given the 3 month precipitation deficits.
CVKING
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1147 PM CDT Thu Mar 27 2014
Convection over southeast sections of the CWA will continue to
move away from the TAF sites, and primary overnight concern deals
with SC and associated MVFR cigs (2-3kft) that are rotating
across the northern half of Missouri in the wake of the cold
front. Earlier RAP runs appear to have the best handle on this low
level moisture, which has now made it as far south as COU, and
should work into the STL metro area over the next few hours. Then
expect cloud deck to gradually clear/dissipate from SW to NE
across the CWA in the 12-16z time frame due to combination of low
level drying, diurnal heating, and loss of cyclonic curvature.
Approach of next shortwave should mean thickening mid clouds by
early tomorrow evening, with a few showers threatening the STL
metro late in the period.
Specifics for KSTL: As mentioned above, MVFR cigs (2-3kft) that have
dropped into mid MO should arrive in the STL area over the next
few hours and linger into early tomorrow morning. Forecast
soundings then suggest a gradual clearing trend by mid morning
which will cause the low cloud deck to scatter out. Mid level
cloud deck in advance of the next system will begin increasing by
late afternoon, with a few showers moving into the area in the
03-06z time frame.
Truett
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 57 41 57 38 / 5 80 5 0
Quincy 51 35 54 36 / 5 10 5 0
Columbia 54 36 59 38 / 10 20 5 0
Jefferson City 56 36 59 37 / 10 20 5 0
Salem 56 40 55 34 / 5 80 10 0
Farmington 61 40 59 35 / 20 80 5 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1203 AM CDT Fri Mar 28 2014
.SHORT TERM: (Through Late Tonight)
Issued at 306 PM CDT Thu Mar 27 2014
A dynamic low pressure system will push rapidly across our
forecast area late this afternoon and this evening. Wind shear
params are quite favorable for strong to severe storms. However,
instability params are currently not as favorable as indicated by
the 18z SGF sounding. It shows a strong mid-level cap (CIN 315
J/kg) and lower instability available without much additional
surface heating.
Some clearing is developing about and hour or two before the line
of storms arrives, per satellite and radar loops. We will continue to
expect a line of convection to race through the area starting
between 4 and 5 pm for our western counties and reaching our
eastern counties by 10 or 11 pm. The primary hazards will be large
hail and damaging winds, especially the cap erodes sufficiently
for uninhibited updrafts.
Behind the line of storms and cold fropa, we should see some
clearing develop from west to east after midnight as steady NW
winds bring colder are to the region.
Shimon
.LONG TERM: (Friday through Next Thursday)
Issued at 306 PM CDT Thu Mar 27 2014
Despite some sunshine on Friday the mixing of 850mb temps in the
2C to 8C range will keep highs around 50 north with around 60
south. Increasing clouds in the afternoon will indicate the
approach of the next low pressure system. That shortwave is
forecast to track just south of Missouri and Illinois, with
varying solutions in the 12z models as to how far north the
precipitation shield will extend Friday evening. The GFS and
Canadian GEM continue to be the most aggressive with the
northern extent, covering a majority of the LSX forecast area,
while the NAM and ECMWF just affect the southeastern third of the
area. We confined likely PoPs in th evening to the southeastern
areas where the best forcing for precip will most likely reside,
with chance PoPs in all but the NW third. After midnight Friday
night, the wave will quickly slide to the east and dry air will
help to limit the northern extent to areas southeast of St Louis.
Dry and cool conditions will return for Saturday as sunshine
prevails for much of the day. Surface ridging and steady height
rises aloft on Sunday will produce a noticeable warming trend, as
highs climb into the mid 60s to around 70. The mild conditions
will extend into Monday but precipitation chances will increase
Monday morning ahead of a cold front. Low pressure will track from
eastern Colorado to Iowa on Monday, as its trailing cold front
reaches western Missouri by 00z/7pm Monday. Moisture will be
limited this far south of the system, so precip coverage only
warranted chance PoPs for now. A few light showers may linger in
western Illinois Monday night, but most areas should see dry
conditions overnight.
The next in a long series of weather systems is projected to
arrive in the area late Tuesday night or Wednesday, as a warm
frontogenesis develops across our forecast area from SW to NE. Per
the GFS, low pressure will eventually track NE along that front
later Wed into Wed evening, increasing precip chances into the
likely category in the NW Wed afternoon and the SE Wed night.
Timing differences in the extended have prompted the inclusion of
chance PoPs as late as Thursday due to the ECMWF indicating a
delayed passage of low pressure along the front.
Shimon
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1147 PM CDT Thu Mar 27 2014
Convection over southeast sections of the CWA will continue to
move away from the TAF sites, and primary overnight concern deals
with SC and associated MVFR cigs (2-3kft) that are rotating
across the northern half of Missouri in the wake of the cold
front. Earlier RAP runs appear to have the best handle on this low
level moisture, which has now made it as far south as COU, and
should work into the STL metro area over the next few hours. Then
expect cloud deck to gradually clear/dissipate from SW to NE
across the CWA in the 12-16z time frame due to combination of low
level drying, diurnal heating, and loss of cyclonic curvature.
Approach of next shortwave should mean thickening mid clouds by
early tomorrow evening, with a few showers threatening the STL
metro late in the period.
Specifics for KSTL: As mentioned above, MVFR cigs (2-3kft) that have
dropped into mid MO should arrive in the STL area over the next
few hours and linger into early tomorrow morning. Forecast
soundings then suggest a gradual clearing trend by mid morning
which will cause the low cloud deck to scatter out. Mid level
cloud deck in advance of the next system will begin increasing by
late afternoon, with a few showers moving into the area in the
03-06z time frame.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS PORTLAND OR
916 PM PDT THU MAR 27 2014
.SYNOPSIS...RAIN WILL INCREASE TONIGHT AS A WARM FRONT APPROACHES
FROM THE SOUTHWEST. WILL HAVE RAIN...HEAVY AT TIMES LATER TONIGHT AND
FRIDAY. COOLER CONDITIONS WITH SHOWERS EXPECTED FRI NIGHT
THROUGH SUN...WITH SNOW AT THE CASCADE PASSES. UNSETTLED WEATHER
CONTINUES INTO NEXT WEEK.
&&
.UPDATE...MADE MINOR CHANGES WITH THE EVENING UPDATE. HAVE ADDED A
SLIGHT CHANCE FOR THUNDERSTORMS TO SW WASHINGTON AND THE NORTHER
OREGON COAST RANGE FRIDAY AFTERNOON AND ACROSS THE ENTIRE PORTLAND
FORECAST AREA SATURDAY AFTERNOON. ALSO INCREASED QPF ALONG THE COAST
AND COAST RANGE A TAD FOR SATURDAY. OTHERWISE...PREVIOUS FORECAST IS
ON TRACK WITH A COMPLEX LOW BRINGING ROUNDS OF RAIN AND MOUNTAIN SNOW
THROUGH EARLY NEXT WEEK. THE FIRST SYSTEM OF INTEREST IS A WARM FRONT
THAT WILL PRODUCE STEADY RAIN AND HIGH ELEVATION (ABOVE 5500 FEET)
SNOW TONIGHT AND FRIDAY. THIS WILL BE CLOSELY FOLLOWED BY A COLD FRONT
FRIDAY NIGHT AND SATURDAY. SNOW LEVELS WILL LOWER SATURDAY AFTERNOON
WITH SNOW ACCUMULATIONS LIKELY FOR THE CASCADE PASSES. THERE IS A
GOOD CHANCE THAT SMALL HAIL WILL ACCOMPANY MANY OF THE SHOWERS
SATURDAY AFTERNOON.HARTLEY
PREVIOUS SHORT TERM DISCUSSION...TODAY THROUGH SATURDAY...
SHOWERS CONTINUE IN THE COOLER ONSHORE FLOW THIS AFTERNOON. THESE MAY
STILL PACK SOME PUNCH...WITH A BRIEF DOWNPOUR. BUT SHOULD NOT BE AS
INTENSE AS THOSE OVER THE PAST FEW DAYS. SHOWERS WILL DECREASE THIS
EVENING AS THE UPPER LOW SHIFTS FURTHER INLAND OVER WASHINGTON.
OCCASIONAL SNOW IN THE CASCADES AS THE PASSES...BUT NOT MUCH MORE
WILL FALL...WITH A FEW MORE INCHES INTO THIS EVENING.
WARM FRONT WILL PUSH INTO THE REGION FROM THE SW TONIGHT. DECENT
ISENTROPIC LIFT STARTS LATER THIS EVENING. LOOKS GOOD THAT RAIN WILL
DEVELOP ALONG THE CENTRAL OREGON COAST THIS EVENING...AND SPREAD N
AND E OVERNIGHT. RAIN WILL BECOME HEAVY AT TIMES LATER TONIGHT AND
CONTINUE ON FRI. STILL LOOKS LIKE GOOD 2 TO 5 INCHES OF RAIN...WITH
HEAVIEST RAINFALL OVER THE OREGON MTNS. IN THE CASCADES...LIKELY 1
TO 3 INCHES OF RAIN. HOWEVER...WILL SEE THIS START AS SNOW WITH 2 TO
5 INCHES ACCUMULATING OVERNIGHT BEFORE TURNING TO RAIN LATE
TONIGHT/EARLY FRI AS SNOW LEVELS CLIMB TO NEAR 6000 FT. BUT ABOVE
6000 FT...COULD GET UP TO 1 FOOT OF SNOW LATER TONIGHT AND FRI.
NOT FLOODING EXPECTED AT THIS TIME...BUT RIVERS WILL SEE SHARP RISES
FRI DUE TO THE RAIN. MODELS MOSTLY AGREE THAT AXIS OF HEAVIEST RAIN
SHIFTS INTO SW OREGON/NW CALIF ON LATER FRI AFTERNOON AND EVENING.
RAIN WILL TRANSITION TO SHOWERS FRI EVENING AS THE FRONT DROPS SLOWLY
SOUTHWARD INTO SW OREGON. OTHER CONCERN WILL BE SOMEWHAT ELEVATED
POTENTIAL FOR MUD/LANDSLIDES DUE TO SATURATED SOILS...PRIMARILY ALONG
THE COAST...THROUGH COAST RANGES AND IN COLUMBIA GORGE ON FRI AND
INTO FRI NIGHT.
EVEN THROUGH PRES GRADIENTS INCREASE TONIGHT AND FRI AM...STILL WILL
NOT BE ENOUGH TO CREATE ANY WIDESPREAD PROBLEMS. THIS SAID IT SEEMS
REASONABLE TO EXPECT GUSTS 40 TO 45 MPH ON THE COAST AND 25 TO 35 MPH
FROM THE COAST RANGE INLAND.
THE UPPER TROUGH WILL REMAIN IN PLACE THROUGH SATURDAY BRINGING
PERIODIC SHOWER BANDS WITH SNOW LEVELS LOWERING TO 4000 FEET
ONCE AGAIN. MAY NEED TO CONSIDER ANOTHER ROUND OF MARGINAL CASCADE
SNOW ADVISORIES DEPENDING ON THE QPF DETAILS THAT EMERGE. SATURDAY
WILL BE A COOL SPRING DAY...WITH PLENTY OF SHOWERS AND EVEN ISOLATED
THUNDERSTORMS WITH SMALL HAIL. WITH SNOW LEVELS STILL DOWN...WILL
CONTINUE TO SEE SNOW IN THE CASCADES. ROCKEY.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
SATURDAY NIGHT THROUGH WEDNESDAY... EXPECT MORE OF THE SAME COOL AND
WET WEATHER FOR THE EXTENDED FCST PERIOD. A BROAD UPPER LEVEL TROUGH
WILL REMAIN OVER THE NE PAC OVER THE WEEKEND AND INTO EARLY NEXT
WEEK. NO SIGNIFICANT IMPACTS ARE EXPECTED DURING THIS TIME...BUT
PERIODIC WAVES ROTATING THROUGH THE TROUGH WILL BRING TIMES OF
ENHANCED SHOWER ACTIVITY. MUCH OF THE PRECIPITATION SHOULD FALL AS
SNOW AT THE CASCADE PASSES...BUT ACCUMULATIONS SHOULD BE RELATIVELY
LIGHT. OTHERWISE...EXPECT PLENTY OF CLOUDS AND TEMPS A FEW DEGREES
BELOW NORMAL. CONFIDENCE IS INCREASING THAT A MORE ORGANIZED FRONTAL
SYSTEM WILL MOVE INTO THE PAC NW TOWARDS THE MIDDLE OF NEXT
WEEK. PYLE
&&
.AVIATION...EXPECT MAINLY VFR CONDITIONS THIS EVENING TO
TRANSITION TO A MIX OF IFR AND MVFR CONDITIONS. THESE LOWER FLIGHT
CONDITIONS SHOULD PERSIST FOR MUCH OF FRIDAY...WITH NORTHERN TAF
SITES TRENDING VFR EARLIER IN THE AFTERNOON THAN SOUTHERN TAF
SITES.
KPDX AND APPROACHES...STEADIER RAIN WILL BEGIN TO SPREAD IN AFTER
09Z AND CONTINUE FOR MUCH OF FRIDAY. EXPECT A LOT OF MVFR
CONDITIONS LATE TONIGHT AND FRIDAY WITH HIGH END IFR CONDITIONS
POSSIBLE FOR BRIEF PERIODS. EAST WINDS SHOULD KEEP CONDITIONS MORE
ON THE MVFR SIDE THOUGH. /NEUMAN
&&
.MARINE...WINDS HAVE BEEN SLOWER TO INCREASE THAN MODELS HAVE
PREDICTED THUS FAR. NONETHELESS...BUOY 50 IS STARTING TO PICK UP AND
SHOULD INCREASE INTO LOW END GALE FORCE LEVELS AFTER MIDNIGHT. THE
LATEST RAP MODEL WINDS SHOULD LOW END GALE FORCE WINDS SURGING UP
THE INNER WATERS TO THE COLUMBIA RIVER MOUTH. HOWEVER...THE
NAM...LOCAL WRF MODEL AND HRRR ALL SEEM TO SUGGEST THE HIGHER GUSTS
WILL REMAIN OVER THE CENTRAL OREGON WATERS. AS A RESULT...KEPT THE
INHERITED SMALL CRAFT ADVISORIES IN PLACE FOR THE NORTHERN WATERS
AND THE GALE WARNING FOR THE CENTRAL OREGON WATERS...BUT AM A BIT
WORRIED WE COULD SEE A BRIEF PERIOD OF LOW END GALE FORCE WINDS UP
NORTH. IN ADDITION...A COASTAL JET WILL LIKELY ENHANCE WINDS WITHIN
20 NM OF THE COAST.
SEAS SHOULD BUMP UP A COUPLE FEET FROM THEIR CURRENT LEVELS
FRIDAY...ESPECIALLY OVER THE CENTRAL OREGON WATERS. THIS WILL BE
LARGELY IN RESPONSE TO THE GUSTY WINDS TONIGHT AND FRIDAY MORNING.
/NEUMAN
ANOTHER SYSTEM WILL BRING ANOTHER SURGE OF WINDS ON SAT...WITH
ANOTHER LOW END GALE LOOKING LIKE A POSSIBILITY AT THIS POINT.
STRONGER WESTERLY SWELL IS MODELED TO BUILD LATE SAT AND SUN. THE
LATEST ENP GUIDANCE INDICATES THAT SEAS MAY BUILD INTO THE MID
TEENS. YET ANOTHER FRONT ARRIVES LATE SUN INTO MON. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 PM PDT FRIDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PDT FRIDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
GALE WARNING UNTIL 1 PM PDT FRIDAY FOR COASTAL WATERS FROM
CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 AM TO
6 AM PDT FRIDAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 PM TO
6 PM PDT FRIDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA..
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1204 AM CDT FRI MAR 28 2014
.AVIATION...
/06Z TAFS/
CONCERNS...IFR CONDITIONS OVERNIGHT AND THUNDERSTORMS FRIDAY
AFTERNOON. A COLD FRONT ARRIVES LATER ON FRIDAY WITH MVFR CIGS
RETURNING BEHIND THE FRONT.
MVFR AND IFR CEILINGS ARE SPREADING WEST ACROSS NORTH AND CENTRAL
TEXAS. EXPECT ALL TAF SITES TO BE UNDER IFR CIGS BY 07Z TONIGHT.
IN ADDITION...AREAS OF FOG ARE POSSIBLE WITH VISIBILITIES 2-5SM.
CONDITIONS WILL IMPROVE LATE FRIDAY MORNING AS A DRYLINE AND COLD
FRONT ENCROACH ALONG THE I-35 CORRIDOR. THE WINDS IN THE METROPLEX
WILL BEGIN TO TURN TOWARD THE WEST IN THE AFTERNOON HOURS AND THEN
THE FRONT ARRIVES AROUND 22Z. SOUTH WINDS WILL PREVAIL AT KACT
WITH LIGHT WINDS IMMEDIATELY AHEAD OF THE FRONT IN THE LATE
AFTERNOON HOURS WITH FROPA AROUND 29/00Z. KACT COULD SEE SOME
SHOWERS AND POSSIBLY ISOLATED THUNDER BY MID TO LATE FRIDAY
MORNING BUT A STRONG SHORTWAVE WILL BRING A CHANCE FOR
THUNDERSTORMS TO ALL THE AIRPORTS DURING THE AFTERNOON HOURS. SOME
OF THE STORMS COULD BE SEVERE. THE THREAT FOR THUNDER WILL END IN
THE EARLY EVENING HOURS.
82/JLD
&&
.UPDATE...
RAN A QUICK UPDATE TO INCREASE POPS FOR THUNDERSTORM CHANCES
ACROSS THE CWA TOMORROW.
WATER VAPOR SATELLITE IMAGERY WAS TRACKING A COMPACT SHORTWAVE
TROUGH OVER SOUTHERN CALIFORNIA...MOVING EAST TOWARDS ARIZONA AND
NEW MEXICO. THIS TROUGH IS EXPECTED TO SPREAD LARGE SCALE FORCING
FOR ASCENT OVER NORTH TX STARTING AROUND 18Z. CONVECTION THIS
EVENING ACROSS THE CWA WAS LIMITED TO COLLIN COUNTY AND AREAS
NORTHEAST...SO ANY REMNANT OUTFLOW BOUNDARIES ARE EXPECTED TO
REMAIN IN PLACE ACROSS THE NORTHEASTERN CWA...IF THEY DONT JUST
DISSIPATE ALL TOGETHER BY TOMORROW MORNING. THE DRYLINE MADE IT
AS FAR EAST AS A GAINESVILLE TO FORT WORTH TO HAMILTON LINE THIS
AFTERNOON...AND WAS OBSERVED TO BE RETREATING BACK TO THE WEST AT
THE TIME OF THIS DISCUSSION. A COLD FRONT WAS OBSERVED ACROSS EAST
CENTRAL OKLAHOMA...STRETCHING BACK WEST TO THE TEXAS PANHANDLE.
THIS BOUNDARY WAS MOVING SLOWLY SOUTH THIS EVENING...AT AROUND 10
MPH.
THE 00Z NAM AND RAP MODELS WERE CONSISTENT IN SHOWING A LOW-LEVEL
(850 MB) THETA-E RIDGE MOVING NORTHEAST ACROSS THE CWA FROM AROUND
THE MILLS/LAMPASAS COUNTY AREA TOMORROW MORNING. THIS THETA-E
RIDGE WAS MORE OR LESS CONSISTENT WITH THE ZONE OF BEST Q-VECTOR
CONVERGENCE OR POSITIVE PRESSURE ADVECTION ON THE 1.5 PVU SURFACE.
AS A RESULT...THINK THAT THE THETA-E RIDGE IS LIKELY TO BE REAL
AND ASSOCIATED WITH LARGE SCALE FORCING FOR ASCENT BROUGHT ON BY
THE APPROACHING SHORTWAVE TROUGH. THIS THETA-E RIDGE IS EXPECTED
TO EXPAND IN AREAL COVERAGE WHILE MOVING NORTHEAST ACROSS THE
SOUTHEASTERN HALF OF THE CWA TOMORROW MORNING. NON-CONVECTION
ALLOWING OPERATIONAL GUIDANCE CONSISTENTLY HAS ITS CONVECTIVE
PARAMETERIZATION SCHEMES TRIGGERED IN THIS ZONE OF RICH THETA-E
AIR...SO CONFIDENCE IN A MORNING ROUND OF LARGELY UNORGANIZED
THUNDERSTORM ACTIVITY HAS INCREASED. WENT AHEAD AND BUMPED UP POPS
TO 30 PERCENT FOR LOCATIONS ALONG AND SOUTH OF A LAMPASAS TO
HILLSBORO TO PALESTINE LINE TOMORROW MORNING AS A RESULT. SEVERE
WEATHER IS POSSIBLE WITH THIS ACTIVITY...BUT SHOULD REMAIN
ELEVATED IN NATURE LEAVING ONLY A MARGINAL HAIL THREAT DURING THE
MORNING HOURS OF THE DAY.
FOR THE AFTERNOON...THE MORNING CONVECTION...DEPENDING ON HOW
STRONG IT IS...AND HOW LARGE ITS AREAL COVERAGE IS...MAY IMPEDE
AFTERNOON THUNDERSTORM INITIATION. AFTERNOON THUNDERSTORM
INITIATION IS MOST LIKELY ALONG THE DRYLINE...AND THEN AGAIN ALONG
THE COLD FRONT. INITIATION IS DEPENDENT UPON GOOD SOLAR INSOLATION
REMOVING A LOW-LEVEL INVERSION AND MIXING OUT LOW-LEVEL MORNING
STRATUS...ALLOWING FOR SURFACE BASED STORMS. MESOSCALE FORCING FOR
ASCENT ASSOCIATED WITH THE COLD FRONT AND DRYLINE WILL CERTAINLY
SUPPORT STRONG LIFT NEAR THESE BOUNDARIES...HOWEVER FORECAST
SOUNDINGS INDICATE TOO MUCH CONVECTIVE INHIBITION TO BE OVERCOME
BY LIFT ALONE. ASSUMING MORNING CONVECTION EITHER DOES NOT PAN
OUT...OR THAT THE CLOUDS CLEAR OUT SUFFICIENTLY TO ALLOW FOR A FEW
HOURS OF HEATING...THUNDERSTORM INITIATION ALONG THESE BOUNDARIES
CAN BE EXPECTED TO OCCUR AROUND 21Z OR 4 PM CDT.
AT 21Z...THE DRYLINE IS EXPECTED TO BE LOCATED JUST WEST OF THE
INTERSTATE 35 CORRIDOR WITH THE COLD FRONT DROPPING SOUTH TO A
SHERMAN TO FORT WORTH TO CISCO LINE. THIS LEAVES THE TRIPLE POINT
NEAR THE DFW AREA...WHERE THE STRONGEST MESOSCALE FORCING FOR
ASCENT SHOULD OCCUR. WENT AHEAD AND BUMPED POPS UP TO 30 PERCENT
NEAR THESE BOUNDARIES...INCREASING TO 50 PERCENT TO THE EAST AND
SOUTHEAST. WITH THE FAST MOVING NATURE OF THE SHORTWAVE TROUGH AND
ITS ENHANCED MID-UPPER LEVEL WIND SPEEDS...ANY INITIATED STORMS
WOULD TEND TO PULL AWAY FROM THESE BOUNDARIES SOMEWHAT QUICKLY.
HIGH RESOLUTION MODELS INDICATE THE POTENTIAL FOR AROUND 2000 J/KG
OF SURFACE BASED CAPE WITH A DEEP LAYER BULK SHEAR MAGNITUDE OF
AROUND 50 KTS...A BASIC PARAMETER SPACE OVERLAP FAVORING AN
ORGANIZED STORM MODE WITH SUPERCELLS...OR CLUSTERS OF STORMS WITH
EMBEDDED SUPERCELL STRUCTURES.
WHETHER THIS MUCH CAPE CAN BE REALIZED OR NOT DEPENDS LARGELY ON
THE FACTORS DISCUSSED ABOVE...AND WILL BE LARGELY UNKNOWN UNTIL WE
SEE HOW MUCH PRECIPITATION EXISTS TOMORROW MORNING. IF THE CAPE IS
REALIZED...THE PRIMARY SEVERE WEATHER HAZARDS SHOULD BE LARGE HAIL
AND DAMAGING WINDS. A CONDITIONAL TORNADO THREAT IS DEPENDENT UPON
INDIVIDUAL STORMS INTERACTING WITH ANY REMNANT BOUNDARIES TOMORROW
AFTERNOON. OVERALL THE TORNADO THREAT DOES NOT LOOK HIGH FROM THE
SYNOPTIC ENVIRONMENT...BUT WE WILL SEE HOW EVERYTHING EVOLVES
AFTER TOMORROW MORNING. THE THREAT FOR TORNADOES LOOKS LOW FOR NOW
AT LEAST. STORMS SHOULD MOVE EAST OF THE CWA QUICKLY AFTER SUNSET
AS THE SHORTWAVE TROUGH PUSHES EAST...AND THE COLD FRONT BEGINS TO
MOVE QUICKLY ACROSS THE CWA.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 311 PM CDT THU MAR 27 2014/
AN UPPER LEVEL TROUGH CAN BE SEEN ON THE LATEST WATER VAPOR LOOP
LIFTING NORTHEAST FROM THE CENTRAL PLAINS TOWARDS THE GREAT LAKES.
A DEEP SURFACE CYCLONE IS FOLLOWING ALONG A SIMILAR PATH BENEATH
THE UPPER TROUGH...AND THE RESULTING FLOW IS SENDING A COLD FRONT
SOUTHWARD TOWARDS NORTH TEXAS. BOTH THE FRONT AND FORCING FOR
ASCENT ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL REMAIN WELL
NORTH OF NORTH TEXAS THIS EVENING. ANY SURFACE FOCUS FOR
CONVECTION WILL BE ASSOCIATED WITH A DRYLINE...WHICH WAS
ENCROACHING ON THE I-35 CORRIDOR THIS AFTERNOON. ISOLATED
THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH SUNSET THIS EVENING
ALONG THE DRYLINE...WITH THE BETTER CHANCES FOR CONVECTION WELL
EAST OF THE DRYLINE WHERE MOISTURE LEVELS ARE HIGHER AND WEAK
ASCENT FROM THE SOUTHERN EXTENT OF THE PLAINS SYSTEM WILL RESIDE.
THOUGH COVERAGE WILL BE LOW DUE TO VEERING SURFACE WINDS AND A
LINGERING CAP OVERHEAD...CAPE OF 1500 TO 2000 J/KG ENSURES THAT
ANY STORMS THAT DEVELOP COULD BECOME STRONG TO POSSIBLY SEVERE
WITH HAIL AND DAMAGING WINDS. WEST OF THE DRYLINE...HIGH FIRE
DANGER WILL CONTINUE FOR A FEW MORE HOURS BEFORE TEMPERATURES FALL
AND WINDS DECREASE AFTER SUNSET.
THE FRONT WILL CROSS THE RED RIVER TONIGHT AND SAG SLOWLY SOUTH
TO NEAR THE I-20 CORRIDOR AROUND NOON FRIDAY...WITH THE DRYLINE
EXTENDING SOUTHWEST FROM THE FRONT ACROSS THE SOUTHWESTERN
COUNTIES BY NOON FRIDAY AS WELL. THESE BOUNDARIES SHOULD BOTH SERVE
AS A FOCUS FOR CONVECTION AS A SECOND UPPER LEVEL TROUGH PASSES
OVERHEAD. THIS FEATURE IS CURRENTLY OVER SOUTHERN CALIFORNIA AND
WILL MOVE QUICKLY EASTWARD INTO THE DESERT SOUTHWEST
TONIGHT...THEN ACROSS TEXAS TOMORROW. SUFFICIENT INSTABILITY WILL
BE PRESENT ONCE AGAIN WITH SLIGHTLY BETTER UPPER LEVEL SUPPORT IN
PLACE...AND ANY STORM THAT DEVELOPS MAY BECOME STRONG TO POSSIBLE
SEVERE. THE BEST CHANCES WILL AGAIN BE OVER THE EAST AND SOUTHEAST
COUNTIES WHERE THE HIGHEST MOISTURE LEVELS / 1 INCH OR GREATER
PWATS / WILL BE LOCATED. THE EXTENT OF THE CONVECTION IS SOMEWHAT
OF A QUESTION MARK...WITH NAM12 BEING AGGRESSIVE AND THE GFS MUCH
MORE PASSIVE AND FARTHER EAST WITH THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS. HIGHER COVERAGE THAN TODAY WOULD MAKE SENSE BASED
ON THE ADDITION OF THE COLD FRONT AND THE CLOSER PROXIMITY OF THE
UPPER LEVEL TROUGH. THIS MAY BE NEGATED THOUGH IF THE UPPER LEVEL
FEATURE MOVES ACROSS PRIOR TO PEAK HEATING...LEAVING US IN THE
SUBSIDENT REGION BY AFTERNOON. WE WILL MAINTAIN THE 40 POPS IN THE
EAST ZONES FOR FRIDAY...LOWERING TO 20 IN THE CENTRAL ZONES
INCLUDING THE DALLAS-FORT WORTH METROPLEX FOR NOW.
THIS SYSTEM WILL MOVE EAST OF THE REGION TOMORROW NIGHT...BRINGING
UPPER RIDGING...WIDESPREAD SUBSIDENCE AND NICE WEATHER TO NORTH
TEXAS FOR THE WEEKEND. PLENTIFUL SUN WILL ALLOW HIGH TEMPERATURES
TO CLIMB INTO THE MID AND UPPER 70S... WITH MOSTLY CLEAR SKIES
ALLOWING NIGHT TIME LOWS TO DROP INTO THE MID AND UPPER 40S. A
WEAK DISTURBANCE WILL MOVE ACROSS THE SOUTHERN PLAINS ON
MONDAY...BRINGING AN INCREASE IN CLOUDS BUT LITTLE IN THE WAY OF
PRECIPITATION. MODELS CONTINUE TO ADVERTISE A STRONGER UPPER
TROUGH DEEPENING OVER THE 4-CORNERS REGION WEDNESDAY...WHICH
SHOULD BRING A DECENT CHANCE OF SHOWERS AND THUNDERSTORMS DURING
THE MIDDLE PART OF NEXT WEEK.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 57 79 48 76 49 / 20 30 30 0 0
WACO, TX 59 82 49 77 48 / 20 50 50 0 0
PARIS, TX 60 76 45 73 45 / 40 20 20 0 0
DENTON, TX 53 77 45 75 44 / 20 20 20 0 0
MCKINNEY, TX 57 78 46 75 45 / 20 30 30 0 0
DALLAS, TX 59 79 49 76 50 / 20 30 30 0 0
TERRELL, TX 60 80 47 75 46 / 30 40 40 0 0
CORSICANA, TX 62 81 49 76 47 / 30 50 50 0 0
TEMPLE, TX 60 82 50 78 48 / 20 50 50 0 0
MINERAL WELLS, TX 51 80 45 77 44 / 10 10 10 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/69
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
436 AM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT WILL ENTER OUR REGION BY TONIGHT. ANOTHER AREA OF
LOW PRESSURE WILL RIDE EASTWARD ALONG THE STALLED FRONT FROM THE
MIDDLE MISSISSIPPI VALLEY ON SATURDAY. THIS FRONT WILL EXIT THE
COAST SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM EDT FRIDAY...
WINDS EARLY THIS MORNING WILL STAY GUSTY OVER THE HIGHER RIDGES AND
THROUGH SOME GAPS ON THE NORTH SIDE OF TWO MOUNTAINS. NOT GETTING
ANY REPORTS OF WIND DAMAGE/POWER OUTAGES...BUT HAD ONE SPOTTER
REPORT GUSTS OVER 50 MPH PER WIND INSTRUMENT. GIVEN LACK OF COVERAGE
OVERALL AND WITH SFC/LOW LVL FLOW STARTING TO VEER MORE TOWARD SOUTH
TO SSW...AN ADVISORY IS NOT NEEDED. OUR TYPICAL WINDIEST PLACES IN
THIS PATTERN HAVE ONLY GUSTED TO 42 MPH IN TAZEWELL COUNTY. AN SPS
WAS ISSUED TO COVER THE HIGHER RIDGES UNTIL THE LOW LVL JET LIFTS
NORTH.
RAIN SHOWERS FORMING ALONG WEAK THETA-E RIDGE AHEAD OF THE MAIN
SYSTEM OVER THE NEW RIVER VALLEY THIS MORNING AND BLUE RIDGE. MAINLY
WILL SEE ISOLATED/SCATTERED COVERAGE EARLY BEFORE MAIN LINE BATCH
MOVES IN AFTER 12Z. STILL NOT SEEING WIDESPREAD COVERAGE BUT ENOUGH
TO WARRANT LIKELY TO CATEGORICAL POPS OVER THE WEST LATER THIS
MORNING...AS THETA-E RIDGE SHIFTS FROM FAR SW VA INTO THE NRN VA
AREA. THE LATEST HRRR IS HANDLING THIS PRETTY WELL IN REGARDS TO
PRECIP AND SHOWS POTENTIAL BREAK IN THE ACTION MID MORNING...AS ONE
AREA OF SHOWERS MOVES INTO THE SHENANDOAH VALLEY...AND THE NEXT AREA
SLIDING NORTHEAST TOWARD THE NC MTNS/FAR SW VA AGAIN BY MIDDAY. WILL
LEAN THIS MORNING POPS THIS WAY...BLENDING TOWARD A GFS/SREF/ECMWF
SOLUTION BY AFTERNOON. GFS DRYING IT FASTER WHICH AGREES WITH THE
00Z WRF/HRRR TO SOME EXTENT AS WELL AS THE 00Z NAM. THIS AFTERNOON
WILL HAVE CHANCE POPS ACROSS THE NRN CWA TO LIKELY IN THE SRN TIER
FROM THE NC MTNS TO SOUTHSIDE VA...WITH POTENTIAL FOR SLIGHT CHANCE
TO NO CHANCE RAIN AROUND 00Z NORTH OF INTERSTATE 64.
TEMPS WILL BE MILD TODAY BUT CLOUDS/RAIN SHOWERS WILL HELP TO KEEP
THEM COOLER THAN NORMAL. MAV/MET BLEND SEEMS TO HANDLE THIS BEST.
LOOK FOR HIGHS FROM THE LOWER TO MID 50S NORTH CAROLINA MTNS/SRN
BLUE RIDGE OF VA TO LOWER TO MID 60S ACROSS THE MTN EMPIRE AS WELL
AS THE PIEDMONTS AND ROANOKE VALLEY.
TONIGHT...A DRYING OUT SOME ALOFT WITH LOW LVL MOISTURE STAYING
CLOSE AT HAND...SO WILL SEE SOME LIGHT RAIN EARLY IN THE SOUTH WITH
MAIN WAVE OF LOW PRESSURE TRACKING TOWARD MID TN/SRN KY BY LATE
TONIGHT. THIS WILL BUCKLE THE FRONT NORTH AGAIN WITH CATEGORICAL
RAIN RETURNING FROM SOUTH TO NORTH OVERNIGHT. MILD LOWS IN THE
40S...LOWER 50S.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AN UPPER LEVEL TROUGH WILL TRACK EAST OVER THE MID WEST
GENERATING A SURFACE LOW THAT WILL TRACK ALONG THE FRONTAL
BOUNDARY SATURDAY MORNING. THE UPPER LEVEL TROUGH WILL START TO
CLOSE OFF SATURDAY AFTERNOON...WITH A NEW SURFACE LOW DEVELOPING
ALONG THE LEE SIDE OF THE SOUTHERN APPALACHIANS. THIS SURFACE LOW
IS EXPECTED TO TRACK ACROSS THE CAROLINA-VIRGINIA PIEDMONT
SATURDAY AFTERNOON/EVENING...THEN OFF THE DELMARVA COAST SATURDAY
NIGHT. THE GFS HAS THE CLOSED UPPER LOW OVER WEST VIRGINIA
SATURDAY EVENING...TRACKING OVER THE FORECAST AREA AND ACROSS
SOUTHERN VIRGINIA SUNDAY MORNING. THE NAM/ECM HAS THE CLOSED LOW
SLIGHTLY FARTHER TO THE SOUTH...TRACKING FROM SOUTHWESTERN
VIRGINIA SATURDAY EVENING...ACROSS NORTH CAROLINA THROUGH THE
MORNING...THEN OFF THE NORTH CAROLINA COAST BY SUNDAY EVENING.
WITH AMPLE MOISTURE AND GOOD JET DYNAMICS...MOST OF SATURDAY WILL BE
WET. THE GOOD NEWS IS THAT IT WILL FALL AS RAIN AND NOT SNOW. AS THE
SECOND LOW TAKES SHAPE AND RACES NORTHEAST OF THE AREA SATURDAY
EVENING...A DRY SLOT WILL TEMPORARILY END THE RAIN SHOWERS. RAIN
SHOWERS RE-ENTERS THE AREA AS THE UPPER LEVEL LOW TRACKS EAST
THROUGH SUNDAY MORNING. TEMPERATURES SHOULD REMAIN WARM ENOUGH ON
THE FRONT END OF THIS LOW TO KEEP P-TYPE AS LIQUID. ON THE BACK
SIDE...COLD AIR AND WRAP-AROUND MOISTURE MAY CHANGE RAIN OVER TO
SNOW/GRAUPEL FOR THE MOUNTAINS...POSSIBLY EAST OF THE BLUE RIDGE
SUNDAY MORNING. CAN NOT RULE OUT A STRIKE OR TWO OF LIGHTNING AS THE
UPPER LOW MOVES OVERHEAD...BUT WILL LEAVE OUT OF THE WEATHER GRIDS
WITH IT TRACKING OVER IN THE MORNING. BY SUNDAY
EVENING...PRECIPITATION WILL BE EAST OF THE AREA...THEN THE WINDS
WILL PICK UP FROM THE NORTH-NORTHWEST. HIGH PRESSURE BUILDS IN
QUICKLY TO CONFINE STRONGEST WINDS TO A 12 HOUR PERIOD
SUNDAY...WEAKENING THROUGH THE NIGHT.
RAINFALL AMOUNTS SATURDAY INTO SATURDAY EVENING WILL RANGE FROM A
THIRD TO THREE-QUARTERS OF AN INCH. IF TODAYS RAIN IS SIGNIFICANT
ENOUGH AND MODELS MAINTAIN SIMILAR QPF TOTALS FOR SATURDAY...A FLOOD
WATCH MAY BE ISSUED. CONFIDENCE IS LOW AT THIS TIME.
CONSIDER WINTERS GRIP ON THE AREA THIS YEAR...HESITANT TO GO WITH A
LITTLE IF ANY SNOWFALL STATEMENT. BOTH THE NAM AND ECM PAINT A
DUSTING TO AN INCH ACROSS THE MOUNTAINS AND INTO THE FOOTHILLS FROM
MIDNIGHT TO NOON SUNDAY. THE GFS IS SIMILAR BUT WITH A 3-4 INCH
BULLEYE CENTERED ON SNOWSHOE WV. WITH THE UPPER LEVEL LOW COMING
OVER DURING THE MORNING...CHANCES ARE GOOD FOR SNOWFALL ESPECIALLY
ACROSS THE WEST. IF THE UPPER LOW IS SLOW TO MOVE ACROSS THE
AREA...THEN WE CAN NOT RULE OUT A COMMON INCH OR TWO ACROSS THE
MOUNTAINS...SLIGHTLY HIGHER AMOUNTS ALONG HIGHER ELEVATIONS.
HOWEVER...MODELS ZIP THE UPPER LOW ACROSS THE FORECAST AREA...WITH A
NARROW BAND OF MOISTURE BEHIND IT...TO KEEP TOTALS UNDER AN INCH.
THERE IS A WIDE RANGE IN GUIDANCE TEMPERATURES FOR SATURDAY. FOR
EXAMPLE...GFSMOS FOR ROANOKE IS 66F WHILE THE NAM IS FORECASTING
50F. THE ECMMOS IS 61F. WITH RAIN EXPECTED FOR MUCH OF THE
DAY...KEPT TEMPERATURES COOL...OBVIOUSLY BETWEEN GUIDANCE...SIMILAR
TO PREVIOUS FORECAST. WITH AN EARLY EXIT OF THE CLOSED
LOW...TEMPERATURES WILL REBOUND QUICKLY SUNDAY AFTERNOON. GUIDANCE
WAS A LITTLE MORE HELPFUL WILL FORECASTED HIGHS AROUND 5F COLDER
THAN NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EST THURSDAY...
LOOKS LIKE MARCH WILL GO OUT LIKE A LAMB AS THE FIRST HALF OF NEXT
WEEK LOOKS DRY. 1024 MB SURFACE HIGH IS PROGGED TO PASS OVHD
MONDAY...FOLLOWED BY A DRY FRONTAL PASSAGE TUESDAY. ASIDE FOR SOME
SCATTERED CLOUDS AND A WIND SHIFT TUESDAY...NO SENSIBLE WEATHER
CHALLENGES ANTICIPATED FOR MONDAY THROUGH WEDNESDAY.
THAT SAID...NOT QUITE AS PRISTINE FROM THE ROCKIES INTO THE UPPER
MID WEST WHERE THE STORM TRACK WILL NOT BE AS FORGIVING. THIS MID
CONUS STORMINESS WILL EVENTUALLY WORK ITS WAY TOWARD THE EAST COAST
BY THE END OF THE WEEK WITH THE BAROCLINIC ZONE SLIDING BACK OUR WAY
WITH THE THREAT FOR UNSETTLED WEATHER FROM THURSDAY INTO NEXT
WEEKEND.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
AS OF 140 AM EDT FRIDAY...
EXPECT VFR CONDITIONS THIS MORNING. HOWEVER...THERE WILL BE LOW
LEVEL WIND SHEAR PRIOR TO SHOWERS ARRIVING AT ALL TERMINALS BUT
BLF WHERE THEY WILL BE MIXING ABOVE THE INVERSION.
CIGS WILL LOWER THROUGH THE MORNING WITH SHOWERS ENTERING BLF/LWB
FIRST AROUND 10Z...REACHING BCB/ROA 11-12Z AND MAKING IT TOWARD
LYH/DAN 13-15Z.
THERE WILL BE PERIODS OF MODERATE SHOWERS WHICH COULD TAKE THE
VSBY DOWN TO MVFR...BUT AMOUNT OF TIME THIS OCCURS WILL BE LESS
THAN TEMPO GROUPS PROVIDE EXCEPT BCB IN THE 12-14Z.
THIS AFTERNOON...THE MAIN AREA OF SHOWERS WILL BE SHIFTING SE OF
THE AREA...BUT WILL STILL SEE SPOTTY SHOWERS AROUND...BUT AGAIN
TOUGH TO PINPOINT WHEN AND IF IT WILL HIT ANY TAF SITES. SHOULD
SEE SOME MVFR IMPROVE BACK TO VFR THIS AFTERNOON AS WELL.
THE NEXT UPSTREAM WAVE OF LOW PRESSURE WILL BUCKLE THE FRONT
TOWARD THE NORTH...AND MODELS FAVOR A RETURN TO EITHER LIGHT
RAIN/DRIZZLE AT MOST SITES FRIDAY EVENING WITH CIGS DROPPING BACK
TO LOW END MVFR AND SOME IFR.
ANOTHER STRONGER COLD FRONT WILL MOVE THROUGH THE REGION ON
SATURDAY. THERE WILL BE BETTER CHANCE FOR SOME ISOLATED TO
SCATTERED THUNDERSTORMS BE ASSOCIATED WITH THE FRONT. AGAIN...MOST
AREAS WILL REMAIN VFR OUTSIDE THE STRONGER CELLS ALONG THE FRONT.
SATURDAY NIGHT INTO SUNDAY...STRONG NORTHWEST WINDS ARE EXPECTED
AS THE PARENT UPPER LOW MAKES ITS WAY ACROSS THE AREA. UPSLOPE
SHOWERS ARE POSSIBLE ALONG A KLWB-KBLF LINE INTO SUNDAY. DRY
WEATHER AND VFR CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY.
&&
.EQUIPMENT...
AS OF 135 AM EDT THURSDAY...
ACCESS TO DATA ON OUR WEB PAGE...WWW.ERH.NOAA.GOV/RNK/...REMAINS
LIMITED DUE TO REGIONAL SERVER ISSUES. THERE IS NO ESTIMATE AT
THIS TIME FOR WHEN IT WILL BE REPAIRED.
OUR NEW...BUT UNFINISHED SITE...WWW.WEATHER.GOV/RNK/ IS OPERATING
PROPERLY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...RCS
LONG TERM...PM
AVIATION...DS/JC/WP
EQUIPMENT...AMS/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
311 AM CDT FRI MAR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CDT FRI MAR 28 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE U.S. WEST COAST INTO BRITISH COLUMBIA...A
PACIFIC SHORTWAVE OVER WYOMING...A VIGOROUS PACIFIC SHORTWAVE NEAR
DAVENPORT IA...AND A POLAR SHORTWAVE OVER LAKE WINNIPEG. THE
DAVENPORT IA SHORTWAVE...IN COMBINATION WITH PRECIPITABLE WATER
VALUES OF 0.6-0.9 INCHES / 200 PERCENT OF NORMAL / AND FRONTOGENESIS
HELPED PRODUCE PRECIPITATION ACROSS MUCH OF THE FORECAST AREA
YESTERDAY TO AROUND MIDNIGHT. MUCH OF THIS PRECIPITATION FELL AS
RAIN...WHICH WITH FROZEN GROUND HAS LED TO PLENTY OF RUNOFF AND
RISES ON AREA RIVERS AND STREAMS. SEE THE HYDROLOGY SECTION FOR MORE
INFORMATION. SOME OF THE PRECIPITATION FELL AS SNOW...MAINLY IN
NORTHWEST TO NORTH SECTIONS OF THE AREA...WITH THE MOST IN TAYLOR
COUNTY. LOW LEVEL CYCLONIC FLOW AROUND LOW PRESSURE OVER CENTRAL
LAKE MICHIGAN HAS KEPT CLOUDS IN PLACE THROUGH THE NIGHT...THOUGH
CLEARING WAS EVIDENT OVER THE NORTHWEST HALF OF MINNESOTA.
PRECIPITABLE WATER AT BIS WAS QUITE LOW WITH THE RIDGE...0.17 INCHES
AT BIS AND ABR OR 50-60 PERCENT OF NORMAL. COLDER AIR WAS ALSO
FILTERING IN...REFLECTING A CANADIAN RIDGE OF HIGH PRESSURE BUILDING
SOUTH INTO THE UPPER MIDWEST. FARTHER TO THE WEST...CLOUDS AND SOME
SCATTERED LIGHT PRECIPITATION WAS OCCURRING OVER WYOMING WITH THE
SHORTWAVE THERE.
AFTER AN ACTIVE PERIOD OF PRECIPITATION THE PAST 24 HOURS...THIS
SHORT TERM PERIOD LOOKS MUCH QUIETER. FOCUS FOR ANY POTENTIAL
PRECIPITATION WOULD BE ON THE SHORTWAVE OVER WYOMING...WHICH IS
PROGGED BY MODELS TO CROSS THE FORECAST AREA TONIGHT. HOWEVER...
THERE ARE 2 ITEMS GOING AGAINST PRECIPITATION... 1. ANOTHER
SHORTWAVE COMING OUT OF ARIZONA IS SUGGESTED TO INTENSIFY AND DEEPEN
AS IT REACHES MISSOURI TONIGHT...ROBBING THE WYOMING SHORTWAVE OF
MOISTURE. 2. THE WYOMING SHORTWAVE WILL BE HEADING INTO A DRY
AIRMASS AS SEEN ON THE BIS/ABR SOUNDINGS. MODELS CONTINUE TO DEPICT
THAT ANY PRECIPITATION WITH THE SHORTWAVE WILL DRY UP BEFORE THE
SHORTWAVE GETS TO THE FORECAST AREA...THUS STAYED WITH A DRY
FORECAST.
CLOUDS AND TEMPERATURES NOW BECOME THE MAIN CONCERNS. LOW CLOUDS
LOOK TO QUICKLY EXIT OFF TO THE EAST THIS MORNING AS THE DRIER AIR
TO OUR NORTHWEST ADVECTS IN. SCT-BKN MID AND HIGH CLOUDS WILL THEN
TRAVERSE THE AREA THIS AFTERNOON THROUGH TONIGHT AS THE WYOMING
SHORTWAVE MOVES THROUGH. 925MB TEMPS ARE PROGGED BETWEEN -2 TO -6C
AT 18Z...THOUGH MORE SUN TODAY WILL HELP TO COUNTERACT SOME OF THE
COLDER AIR. IN FACT...OVER THE SNOW FREE AREAS...TEMPERATURES MAY
EVEN END UP A LITTLE WARMER THAN YESTERDAY. ALTHOUGH SURFACE WINDS
LOOK LIGHT TONIGHT...THE CLOUDS SHOULD HELP TO HOLD READINGS UP FROM
THE MID TEENS TO MID 20S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 311 AM CDT FRI MAR 28 2014
MUCH OF THE LONG TERM PERIOD FOCUSES ON AN IMPRESSIVE LONG WAVE
TROUGH SITTING OVER THE EASTERN PACIFIC. ALL MODELS SHOW THAT A
POTENT SHORTWAVE WILL COME OUT OF THIS TROUGH AND TRACK INTO THE
FORECAST AREA FOR MONDAY. THEN THE ENTIRE TROUGH LOOKS TO COME INTO
THE WESTERN U.S. ON TUESDAY...TRACKING INTO THE CENTRAL PLAINS ON
THURSDAY.
MUCH OF FRIDAY NIGHT THROUGH SUNDAY LOOKS TO BE DOMINATED BY
BUILDING RIDGING AHEAD OF THE POTENT SHORTWAVE MARCHING ACROSS THE
WESTERN U.S.. NO CONCERNS FOR PRECIPITATION DURING THIS PERIOD AS
THE FORECAST AREA TRANSITIONS FROM UNDER DOMINANCE OF HIGH PRESSURE
TO INTO THE WARM SECTOR OF A DEEPENING SURFACE CYCLONE OVER
NORTHEAST COLORADO. TEMPERATURES AND WINDS ARE THE MAIN ISSUES.
925MB TEMPS ARE PROGGED SLIGHTLY WARMER ON SATURDAY...0 TO -
4C...WHICH WITH WHAT LOOKS TO BE PLENTY OF SUN SHOULD HELP BOOST
TEMPS INTO THE 40S...PERHAPS EVEN AROUND 50 IN SOME VALLEY
LOCATIONS. SOUTH TO SOUTHWEST WINDS REALLY PICK UP SATURDAY
NIGHT...UPWARDS OF 40-50 KT BY 12Z SUN AT 925MB...CAUSING 925-850MB
TEMPS TO REALLY CLIMB. ANTICIPATING LOWS IN THE EVENING SATURDAY
NIGHT...THEN HOLD STEADY TO SLOWLY RISE AS THE WARM AIR SURGES IN.
THE CLIMB CONTINUES THROUGH SUNDAY AS THE 925MB TEMPS CLIMB TO AS
MUCH AS 10-13C BY 00Z MONDAY. 400-250MB RH PROGS SUGGESTS PLENTY OF
SCT-BKN CIRRUS...BUT THE SUN AND WARM 925MB TEMPS SHOULD HELP PROPEL
READINGS INTO THE FIRST 60S OF THE YEAR FOR MOST LOCATIONS. MORE
SNOWPACK OVER TAYLOR/CLARK WILL HOLD READINGS BACK THERE INTO THE
50S...THOUGH THIS SNOWPACK IS GOING TO MELT FAST GIVEN THE WARM AIR
AND BREEZY CONDITIONS...YIELDING HYDRO CONCERNS. SEE HYDROLOGY
SECTION.
ATTENTION THEN TURNS TO THE POTENT SHORTWAVE HEADING INTO THE
FORECAST AREA FOR MONDAY. BOTH THE GFS AND ECMWF HAVE REALLY SLOWED
AND DEEPENED THIS SHORTWAVE AND THE ASSOCIATED SURFACE LOW OVER THE
PAST 24-48 HOURS. THIS RESULTS IN THE FORECAST AREA STAYING IN THE
WARM SECTOR LONGER AND THUS WARMER CONDITIONS ARE FORECAST FOR
SUNDAY NIGHT AND MONDAY. THERE ARE A COUPLE OF PRECIPITATION IMPACTS
TOO. FIRST...THE DEFORMATION BAND ON THE NORTHWEST SIDE OF THE LOW
NOW ONLY LOOKS TO IMPACT THE NORTHWEST HALF OF THE AREA MONDAY
AFTERNOON AND NIGHT...THOUGH IT MAY STAY ENTIRELY NORTHWEST OF THE
FORECAST AREA. SECOND...A LEAD WAVE OF RAIN RESULTING FROM
ISENTROPIC LIFT IS LOOKING LIKELY TO PROGRESS ACROSS THE FORECAST
AREA LATE SUNDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THIRD...THE
SYSTEMS COLD FRONT AND STRONG DYNAMICS ARE PROGGED TO MOVE THROUGH
MONDAY AFTERNOON AND EVENING. THERE IS A CAP TO BE OVERCOME...BUT
WITH SUCH STRONG FORCING...CANNOT RULE OUT A BAND OF SHOWERS AND
STORMS FIRING ON THE FRONT. SHOULD STORMS FORM...WHICH IS A BIG
IF...THERE IS AMPLE SHEAR TO SUPPORT SEVERE. WE WILL NEED TO KEEP AN
EYE ON INSTABILITY VERSUS CAPPING FOR MONDAY AFTERNOON.
TUESDAY INTO TUESDAY NIGHT LOOK TO BE QUIET AND MUCH COLDER...THEN
WEATHER GETS ACTIVE AGAIN FOR WEDNESDAY INTO THURSDAY AS THE REST OF
THE UPPER TROUGH LIFTS TOWARDS THE REGION. THIS TIME AROUND...WE MAY
HAVE TO DEAL WITH A WINTRY MIX SIDE DUE TO WARM/MOIST ADVECTION
ALOFT AND A FLOW OF DRY AIR AND COLD ADVECTION AT THE SURFACE.
THEN...IF THE 28.00Z ECMWF IS CORRECT...WE WILL AT LEAST CHANGE OVER
TO ALL RAIN AND PERHAPS BRING MORE THUNDERSTORMS. NEEDLESS TO
SAY...PLENTY OF UNCERTAINTY OUT THIS FAR AND THUS STAYED WITH A
MODEL CONSENSUS FOR NOW. CERTAINLY ANOTHER ITEM TO WATCH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1159 PM CDT THU MAR 27 2014
MAIN AREA OF PRECIPITATION CONTINUES TO PROGRESS STEADILY EASTWARD
AND WILL BE PAST KLSE BY 06Z. HOWEVER...THE LOW CLOUDS AND IFR
CEILINGS WILL CONTINUE THROUGH MUCH OF THE NIGHT. OBSERVATIONS
INDICATE CEILINGS OF A THOUSAND FEET OR LESS EXTEND BACK INTO
WESTERN IOWA WITH MVFR CEILINGS TO THE MISSOURI RIVER. THE 28.00Z
NAM CONTINUES TO HAVE A GOOD HANDLE ON THIS MOISTURE AND SHOWS
THESE CLOUDS REMAINING THROUGH THE NIGHT AND DISSIPATING UNTIL MID
MORNING. GRADIENT IS TIGHT ENOUGH BEHIND THE PASSING SURFACE LOW
FOR SOME GUSTY NORTH TO NORTHWEST WINDS THROUGH THE NIGHT AS WELL.
THESE WILL ALSO SETTLE DOWN BY MID MORNING. SHORT WAVE TROUGH
COMING ACROSS THE NORTHERN ROCKIES IS EXPECTED TO AMPLIFY AND MOVE
SOUTH OF THE REGION FRIDAY. THIS SHOULD STILL PASS CLOSE ENOUGH TO
PRODUCE MID LEVEL CLOUDS ACROSS THE REGION WITH A VFR CEILING.
HIGH PRESSURE WILL DOMINATE AT THE SURFACE WITH ANY PRECIPITATION
FROM THE WAVE STAYING WELL TO THE SOUTH OF THE AREA.
&&
.HYDROLOGY...
ISSUED AT 311 AM CDT FRI MAR 28 2014
AREA RIVERS AND STREAMS CONTINUE TO MOSTLY RISE EARLY THIS MORNING
FROM THE RECENT RAIN. RAINFALL AMOUNTS AS MUCH AS A LITTLE OVER 1
INCH WERE OBSERVED...HIGHEST OVER THE SOUTHEAST HALF OF THE
FORECAST AREA. WITH FROZEN GROUND...MUCH OF THIS RAIN HAS TURNED
INTO RUNOFF. SO FAR THE ONLY FLOOD WARNING ISSUED AND VERIFIED WAS
ONTARIO...WHILE MOST OTHER RIVERS AND STREAMS ARE STAYING BELOW
FLOOD STAGE. EXPECTING MOST SHORT RESPONDING SITES LIKE ONTARIO TO
BEGIN FALLING SOON...WHILE LONGER RESPONDING LOCATIONS WILL CLIMB
FOR THE NEXT DAY OR SO AS RUNOFF CONTINUES TO FILTER THROUGH. SEE
THE LATEST HYDROLOGY RELATED STATEMENTS FOR MORE DETAILS.
NEXT HYDROLOGY CONCERN COMES SUNDAY THROUGH MONDAY AS A STRONG
SURGE OF WARM AIR COMES INTO THE REGION ON BREEZY SOUTH WINDS. IN
ADDITION...RAIN APPEARS LIKELY ON MONDAY. WITH PLENTY OF SNOW
STILL PRESENT ALONG/NORTH OF HIGHWAY 10...CONCERN THAT THIS SNOW
COULD RAPIDLY MELT...RESULTING IN MORE RISES ON RIVERS SUCH AS THE
TREMPEALEAU AND BLACK. WILL ISSUE AN ESF TO COVER THE POTENTIAL
FOR FLOODING. SOMEWHAT COOLER AIR FLOWING IN FOR TUESDAY AND
WEDNESDAY WILL SLOW THE MELT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1159 PM CDT THU MAR 27 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 355 PM CDT THU MAR 27 2014
AT 3 PM...A 992 MB SURFACE LOW WAS CENTERED OF THE SOUTHWEST
CORNER OF IOWA. THE LATEST MSAS SHOWS 3 HOUR HEIGHT FALLS OF 3
MILLIBARS ACROSS EASTERN IOWA...SOUTHERN WISCONSIN...AND NORTHERN
ILLINOIS. AS RESULT...EXPECT THE LOW TO CONTINUE TO TRACK
NORTHEAST ACROSS IOWA LATE THIS AFTERNOON AND EARLY EARLY EVENING.
MODERATE TO STRONG 850 MB MOISTURE TRANSPORT MOVES INTO NORTHEAST
IOWA...AND SOUTHWEST AND CENTRAL WISCONSIN BETWEEN 27.21Z AND
28.03Z. DUE TO THIS...INCREASED THE PRECIPITATION TOTALS INTO THE
0.35 TO 0.75 INCH RANGE.
IN ADDITION TO THIS...THE MOST UNSTABLE CAPES CLIMB UP TO
300 J/KG ACROSS PARTS OF NORTHEAST IOWA...SOUTHEAST
MINNESOTA...AND SOUTHWEST AND CENTRAL WISCONSIN. THERE HAS ALREADY
BEEN A FEW ISOLATED REPORTS OF LIGHTNING ALONG AND SOUTH OF
INTERSTATE 90 THIS AFTERNOON. WITH THE CAPES A BIT FURTHER NORTH
AND WEST...EXPANDED THE CHANCE OF THUNDERSTORMS MORE INTO
NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND AS FAR AS NORTH OF
INTERSTATE 90 CORRIDOR THROUGH 28.03Z. WITH THE 0-3 KM AND 0-6 KM
SHEAR LESS THAN 30 KNOTS...NOT EXPECTING ANYTHING SEVERE.
MEANWHILE ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL
WISCONSIN...COLD AIR ADVECTION DEVELOPS ACROSS SOUTHEAST
MINNESOTA AND NORTH CENTRAL WISCONSIN. THE NAM IS THE STRONGEST
AND FASTEST WITH THIS COLD AIR ADVECTION. AS A RESULT...IT
PRODUCES MUCH MORE SNOW ACROSS SOUTHEAST MINNESOTA /UP TO 2.5
INCHES IN COBB/ TONIGHT. HOWEVER THE 18Z AMDAR SOUNDINGS SHOW THAT
IT IS A BIT TOO COLD AND MUCH CLOSER TO THE RAP AND GFS. AS A
RESULT...TRENDED THE SWITCH OVER FROM RAIN TO SNOW A BIT LATER
THAN PREVIOUSLY FORECAST. IT LOOKS LIKE THIS WILL OCCUR...NORTH
OF INTERSTATE 94 BETWEEN 27.21Z AND 28.00Z...WEST OF MISSISSIPPI
RIVER BETWEEN 28.00Z AND 28.03Z...AND ACROSS THE REMAINDER OF THE
AREA BETWEEN 28.04Z AND 28.08Z. SOUTHEAST MINNESOTA WILL SEE UP TO
AN INCH...AND AROUND 3 INCHES NORTH OF WISCONSIN 29 IN NORTH
CENTRAL WISCONSIN. ELSEWHERE VERY LITTLE...IF ANY...SNOW IS
EXPECTED.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 PM CDT THU MAR 27 2014
ON SUNDAY...A TIGHT PRESSURE GRADIENT DEVELOPS ALONG AND SOUTH OF
THE INTERSTATE 90 CORRIDOR AHEAD OF A DEEPENING LOW OVER THE
NORTHERN PLAINS. THIS TIGHT PRESSURE GRADIENT WILL ALLOW THE
SUSTAINED SOUTH WINDS TO CLIMB INTO THE 15 TO 25 KNOT RANGE AND
THE WINDS WILL GUST UP TO 35 MPH. AT THE SAME...THE 850 MB
TEMPERATURES WILL CLIMB INTO THE 10 TO 14C RANGE ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA. BUFKIT SOUNDING SHOW THAT WE
WILL NOT QUITE MIX UP TO THIS LEVEL...BUT WE WILL MIX UP INTO THE
900 TO 875 MB LAYER...AND THIS WILL ALLOW TEMPERATURES TO CLIMB
INTO THE LOW AND MID 50S NORTH OF INTERSTATE 94...AND AROUND 60
ACROSS THE REMAINDER OF THE AREA.
FROM SUNDAY NIGHT INTO MONDAY NIGHT...THE MODELS CONTINUE TO SHOW
THAT A NEGATIVELY TILTED SHORT WAVE TROUGH WILL MOVE THROUGH THE
FORECAST AREA. TEMPERATURES ALOFT ARE WARM ENOUGH THAT MUCH OF THE
PRECIPITATION WILL FALL MAINLY IN THE FORM OF RAIN. WHILE THE
0-6 KM SHEAR ARE GREATER THAN 35 KNOTS...THERE IS VERY LITTLE
CAPE ACROSS THE REGION...SO THERE IS NOT ANY THREAT FOR ANY SEVERE
WEATHER.
BEYOND THIS TIME PERIOD...THE 27.00Z MODELS HAVE DIFFERING
OPINIONS ON HOW FAR NORTH A LOW WILL TRACK THROUGH NORTHERN AND
MID MISSISSIPPI RIVER VALLEY. THE ECMWF IS MUCH FURTHER NORTH THAN
THE GFS. WITH SUCH DIVERSE SOLUTIONS...JUST STAYED WITH THE MODEL
CONSENSUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1159 PM CDT THU MAR 27 2014
MAIN AREA OF PRECIPITATION CONTINUES TO PROGRESS STEADILY EASTWARD
AND WILL BE PAST KLSE BY 06Z. HOWEVER...THE LOW CLOUDS AND IFR
CEILINGS WILL CONTINUE THROUGH MUCH OF THE NIGHT. OBSERVATIONS
INDICATE CEILINGS OF A THOUSAND FEET OR LESS EXTEND BACK INTO
WESTERN IOWA WITH MVFR CEILINGS TO THE MISSOURI RIVER. THE 28.00Z
NAM CONTINUES TO HAVE A GOOD HANDLE ON THIS MOISTURE AND SHOWS
THESE CLOUDS REMAINING THROUGH THE NIGHT AND DISSIPATING UNTIL MID
MORNING. GRADIENT IS TIGHT ENOUGH BEHIND THE PASSING SURFACE LOW
FOR SOME GUSTY NORTH TO NORTHWEST WINDS THROUGH THE NIGHT AS WELL.
THESE WILL ALSO SETTLE DOWN BY MID MORNING. SHORT WAVE TROUGH
COMING ACROSS THE NORTHERN ROCKIES IS EXPECTED TO AMPLIFY AND MOVE
SOUTH OF THE REGION FRIDAY. THIS SHOULD STILL PASS CLOSE ENOUGH TO
PRODUCE MID LEVEL CLOUDS ACROSS THE REGION WITH A VFR CEILING.
HIGH PRESSURE WILL DOMINATE AT THE SURFACE WITH ANY PRECIPITATION
FROM THE WAVE STAYING WELL TO THE SOUTH OF THE AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS EUREKA CA
400 AM PDT FRI MAR 28 2014
.SYNOPSIS...A RAINY FRIDAY IS ON TAP FOR NW CALIFORNIA AS AN
ATMOSPHERIC RIVER SETS IN THIS MORNING. RAIN WILL TAPER TO SHOWERS
ON SATURDAY AND BRING A SLIGHT CHANCE OF A THUNDERSTORM AND SMALL
HAIL.
&&
.SHORT TERM (TODAY THROUGH TUESDAY)...MADE SLIGHT ADJUSTMENTS TO THE
EARLY MORNING FORECAST TO SLOW THE SOUTHERN PROGRESSION OF THE FRONT
BY A COUPLE HOURS. THE ONLY NOTICEABLE CHANGE WILL BE FOR SOUTHERN
MENDOCINO COUNTY THIS MORNING. OTHERWISE LEFT THE FORECAST NEARLY
THE SAME FOR TODAYS RAIN. THE MAIN FORECAST MODELS, THE GFS AND NAM,
CONTINUE TO SHOW THE ONSET OF STEADY RAIN BETWEEN 12Z AND 18Z.
HOWEVER, THE SHORT TERM RUC HOLDS OFF THE ONSET UNTIL ABOUT 18Z TO
19Z. REGARDLESS, PERIODS OF LIGHT RAIN ARE EXPECTED AHEAD OF THE
FULL ONSET OF THE ATMOSPHERIC RIVER RAINS, SO HAVE LEFT THE 100 POPS
FOR THE EARLY MORNING HOURS. LOOKING AT THE GEFS IVT MEAN VS THE OP
GFS IVT FROM THE 12Z RUN YESTERDAY AND THERE APPEARS TO BE A BIT OF
WIGGLE ROOM IN THE EXACT LANDING OF THE AR HEAD. THE GEFS MEAN TAKES
THE BULK OF THE IVT INTO SRN ORE WHILE THE OP GFS BRINGS IT INTO FAR
NORTHERN CAL. CAN NOT FIND ENOUGH EVIDENCE TO LOWER QPF AMOUNTS, BUT
AS THE DAY GOES ON WE MAY NEED TO ADJUST THE QPF DOWNWARD SLIGHTLY.
THIS WILL DEPEND ON WHERE THE HEAD OF THE AR HITS. SNOW LEVELS
WILL REMAIN AROUND 6KFT TODAY WITH ONLY THE HIGHEST PEAKS
RECEIVING ANY SNOW.
THE COLD FRONT STEERING TODAYS AR WILL SLOWLY SINK TO THE SOUTH
THROUGH THE DAY AND OVERNIGHT. AN UNSTABLE COOL AIR MASS WITH
LOWERING HEIGHTS WILL FILL IN BEHIND THE FRONT. A POST FRONTAL
TROUGH WILL BRING INSTABILITY ASSOCIATED WITH A VORT MAX TO THE
REGION ON SATURDAY AS THE TROUGH APPROACHES. MODELS ARE SHOWING
INCREASING CAPE AND LOWERING LI`S WITH THIS VORT MAX. WITH FAIRLY
WARM AIR IN PLACE AT THE SURFACE AND COOLING AIR ALOFT, THE
INGREDIENTS SHOULD BE PRESENT FOR WIDESPREAD CONVECTIVE SHOWERS
ACROSS NWCA. THERE IS A SLIGHT CHANCE SOME OF THESE SHOWERS WILL BE
THUNDERSTORMS, PRODUCING SMALL HAIL AND LOCALLY GUSTY WINDS. THE NAM
IS SHOWING A THIN CAPE PROFILE FOR MUCH OF THE AREA ON SAT WITH
VALUES IN THE FEW HUNDRED J/KG. THE TOP OF THE CONVECTION COULD
REACH AS HIGH AS 22KFT WITH A TEMP OF -37C. THIS SHOULD PROVIDE
ENOUGH DEPTH TO PRODUCE SMALL HAIL. FOR THE FORECAST, WENT AHEAD AND
MATCHED THE NEIGHBORS AND EXPANDED THE SLIGHT CHANCE OF TSTMS ACROSS
THE ENTIRE CWA. SPC CONTINUES TO SHOW NWCA IN THE THUNDERLINE FOR
SAT.
SUNDAY BROUGHT SOME SIGNIFICANT CHANGES TO THE ONGOING FORECAST.
WENT AHEAD AND BIT OFF ON THE IDEA OF A DRY DAY. SO PULLED BACK POPS
TO SLIGHT CHANCE OR LESS. MONDAY HOWEVER I WENT THE OTHER WAY.
MODELS HAVE BEEN CONSISTENT WITH A DIGGING UPPER LOW DIVING INTO
CALIFORNIA AND BRING ANOTHER QUICK SHOT OF RAIN. CONFIDENCE IS
INCREASING FOR RAIN ON MONDAY, SO WENT AHEAD AND UPPED THE POPS TO
100 FOR A SHORT TIME. THIS DIGGING LOW COULD PROVE TO VERY
INTERESTING WITH SHARP COOLING ALOFT, A NEG TILTED TROUGH AXIS, AND
A STRONG VORT MAX. THIS COULD BRING NWCA ANOTHER SHOT OF TSTMS AND
SMALL HAIL ON MONDAY. THE OTHER ISSUE TO WATCH ON MONDAY WILL BE
LOWERING SNOW LEVELS AND WIDESPREAD PRECIPITATION. THIS COULD
BRING A FEW INCHES OF SNOW TO AREA PASSES BY MONDAY EVENING. MORE
TO COME. TUESDAY WILL BRING THE BEGINNING OF A SHORT BREAK IN
WEATHER. BFG
.LONG TERM (WEDNESDAY THRU FRIDAY)...WED WILL CONTINUE A SHORT BREAK
IN THE WEATHER. MODELS ARE INDICATING ANOTHER UPPER TROUGH DIVING IN
FOR THE SECOND HALF OF THE WEEK, BUT ARE HAVING ISSUES WITH TIMING
STRENGTH. WITH A WET PATTERN EXPECTED, KEPT WITH THE IDEA OF LIKELY
RAIN FOR THU THROUGH SAT. CONFIDENCE IS LOW TO MODERATE DUE TO
UNCERTAINTY IN TIMING AND STRENGTH. BFG
&&
.AVIATION...BREEZY SOUTHERLY WINDS WILL ACCOMPANY PERIODS OF
HEAVY RAIN TODAY. EXPECT MVFR WITH PERIODS OF LIFR DURING HEAVY
RAIN ACROSS THE REGION.
&&
.MARINE...SOUTHERLY WINDS WILL PERSIST ACROSS THE WATERS THROUGH THE
MIDDLE OF NEXT WEEK. A SERIES OF LONG PERIOD WESTERLY SWELLS WILL
PROPAGATE ACROSS THE WATERS THROUGH THE MIDDLE OF NEXT WEEK. THE
WINDS AND SEAS WILL INCREASE TODAY AS A COLD FRONT APPROACHES THE
AREA. THE SEAS WILL REMAIN ELEVATED THROUGH THE MIDDLE OF NEXT
WEEK. SMALL CRAFT ADVISORIES ARE IN EFFECT ACROSS THE WATERS
THROUGH EARLY NEXT WEEK.
&&
.HYDROLOGY...
AN ATMOSPHERIC RIVER ACCOMPANIED BY A SLOW MOVING COLD FRONT WILL
BRING COPIOUS AMOUNTS OF RAINFALL TO NORTHWEST CALIFORNIA TODAY
THROUGH SATURDAY MORNING. STEADY RAIN AND OCCASIONAL PERIODS OF
HEAVY RAIN CAN BE EXPECTED AS THE FRONT MOVES ACROSS THE REGION.
THE HIGHER RAINFALL VALUES WILL OCCUR IN DEL NORTE COUNTY AND
ALONG THE COASTAL MOUNTAIN RANGES.
THE RAINFALL WILL BEGIN OVER DEL NORTE COUNTY THIS MORNING AND
MOVE SOUTH ACROSS HUMBOLDT AND TRINITY COUNTIES THROUGHOUT
FRIDAY AFTERNOON AND INTO MENDOCINO COUNTY FRIDAY EVENING.
POTENTIAL IMPACTS:
THE MAIN STEM RIVERS WILL HAVE RAPID RISES...BUT NO FLOODING IS
EXPECTED. ALL THE RIVERS ARE FORECAST TO REMAIN BELOW MONITOR
STAGE.
THE TRIBUTARY STREAMS WILL ALSO RISE BUT ARE EXPECTED TO
REMAIN WITHIN THEIR BANKS.
THERE IS THE POSSIBILITY OF URBAN FLOODING DUE TO CLOGGED STORM
DRAINS. AREAS WITH POOR DRAINAGE AND OTHER LOW LYING AREAS CAN
EXPECT PONDING OF WATER.
AFTER THE FRONT PASSES SCATTERED SHOWERS ARE EXPECTED THROUGHOUT
THE DAY SATURDAY.
FORECAST PRECIPITATION AMOUNTS:
VALID 500 AM FRIDAY TO 500 AM SATURDAY
SMITH RIVER BASIN...........3 TO 4 INCHES
KLAMATH RIVER BASIN.........2 TO 3 INCHES
REDWOOD CREEK BASIN.........2.5 TO 3.5 INCHES
TRINITY RIVER BASIN.........2 TO 3 INCHES
MAD RIVER BASIN.............2 TO 3 INCHES
VAN DUZEN RIVER BASIN.......2.5 TO 3.5INCHES
SF EEL RIVER BASIN..........2.5 TO 3.5 INCHES
EEL RIVER BASIN.............2 TO 3 INCHES
VALID FROM 1100 AM FRIDAY TO 1100 AM SATURDAY
NAVARRO RIVER BASIN.........2 TO 3 INCHES
RUSSIAN RIVER BASIN.........1.5 TO 2.5 INCHES
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 9 AM PDT SUNDAY PZZ450-455-475.
SMALL CRAFT ADVISORY UNTIL 4 PM PDT MONDAY PZZ470.
&&
$$
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AREA FORECAST DISCUSSION
NWS TAUNTON MA
1014 AM EDT FRI MAR 28 2014
.SYNOPSIS...
LOW PRESSURE MOVING ACROSS THE EASTERN GREAT LAKES TODAY WILL
PROVIDE MILD CONDITIONS AND SCATTERED AFTERNOON RAIN SHOWERS TO
SOUTHERN NEW ENGLAND. DRY WEATHER BRIEFLY RETURNS TONIGHT INTO
SATURDAY MORNING BEFORE A COASTAL STORM DEVELOPS SOUTH OF NEW
ENGLAND...BRINGING A CHILLY WINDSWEPT SOAKING RAIN TO THE REGION
SATURDAY NIGHT INTO SUNDAY. DRY WEATHER RETURNS AROUND TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...RAINFALL STARTING TO BECOME MORE WIDESPREAD ACROSS
NORTHWEST MA AND SOUTHWEST NH. TEMPERATURES ACROSS THAT REGION ARE
ALL ABOVE FREEZING NOW...ENDING THE THREAT OF FREEZING RAIN. AS
SUCH...ALLOWED THE WINTER WEATHER ADVISORY TO EXPIRE AT 10 AM.
OTHER THAN THAT...TWEAKED THE NEAR TERM FORECAST TO BETTER REFLECT
OBSERVED TRENDS. THROUGH THE 28/11Z RAP AND HRRR HAD A DECENT
HANDLE ON RAINFALL TIMING...AS DID THE 06Z NAM. INCORPORATED THOSE
SOURCES INTO THIS FORECAST UPDATE. WILL NEED TO KEEP AN EYE ON MAX
TEMPERATURES EARLY THIS AFTERNOON. NOW THAT THE WARM FRONT HAS
PUSHED NORTH...IF THE TIMING OF THICKER CLOUDS IS SLOWER THAN
CURRENT FORECAST THEN THOSE WILL NEED TO BE BUMPED HIGHER.
COVERAGE OF SHOWERS THIS AFTERNOON SHOULD BE SCATTERED SO NOT
EXPECTING A WASHOUT BY ANY MEANS.
AS SURFACE LOW MOVES NORTHEAST THROUGH THE ST LAWRENCE RIVER
VALLEY...WARM SECTOR OVERSPREADS SOUTHERN NEW ENGLAND WITH TEMPS
RISING WELL INTO THE 50S AND POSSIBLY NEAR 60 THIS AFTERNOON. THIS
IS COURTESY OF A STRONG LOW LEVEL SOUTHWEST JET OF 55-65 KT. THIS
WILL RESULT IN WINDY CONDITIONS ACROSS THE REGION WITH STRONGEST
WINDS PER BUFKIT NAM SOUNDINGS ACROSS NORTHEAST MA WITH GUSTS UP
TO 35 KT/40 MPH. NOT QUITE WIND ADVISORY CRITERIA BUT NEVERTHELESS
WINDY CONDITIONS. LESS MIXING ELSEWHERE WILL RESULT IN LOWER WIND
SPEEDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
COLD FRONT SLIPS OFFSHORE ALONG WITH DEEP LAYER MOISTURE. COLUMN
BEGINS TO DRY YIELDING PARTIAL CLEARING ESPECIALLY NORTHERN MA AND
SOUTHWEST NH WITH MID TO HIGH CLOUDS ACROSS CT/RI AND SOUTHEAST MA.
POST FRONTAL AIRMASS NOT COLD AT ALL WITH MINS TONIGHT ONLY IN THE
U30S TO M40S...WARMER THAN NORMAL!
SATURDAY...
DRY TO START ALONG WITH SOME PARTIAL SUNSHINE ESPECIALLY NORTHERN MA
INTO SOUTHWEST NH. ALTHOUGH THIS WILL BE SHORT LIVED AS FRONTAL
BOUNDARY OFFSHORE BEGINS TO MOVE NORTHWARD AS LOW PRES DEVELOPS ON
THE FRONT OVER THE MID ATLC REGION. WARM CONVEYOR BELT RAINS BEGIN
TO MOVE NORTHWARD INTO CT/RI AND SOUTHEAST MA DURING MID TO LATE
AFTERNOON. GOOD MODEL AGREEMENT HERE ON TIMING ONSET OF PRECIP.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
* MORE SEASONABLE TEMPS EXPECTED THROUGH THE LONG TERM
* HEAVY RAIN LIKELY WITH COASTAL STORM THIS WEEKEND
THE 00Z MODELS ARE IN REASONABLY GOOD AGREEMENT ON THE SYNOPTIC
PATTERN. MAIN DIFFERENCES LIE IN THE EXACT TRACK AND SPEED OF A
FAIRLY STACKED SYSTEM MOVING OFF THE MID-ATLANTIC COAST AND
NORTHEASTWARD TOWARDS SOUTHERN NEW ENGLAND. THE 12Z ECMWF IS FASTER
AND A BIT FARTHER NORTH WHILE THE 00Z NAM IS SLOWER AND FARTHER
SOUTH. THE 00Z GFS IS A GOOD MIDDLE GROUND SOLUTION AND IS MORE IN
LINE WITH THE ENSEMBLE MEANS SO WILL LEAN MORE TOWARDS THE GFS TRACK
FOR THIS STORM. THIS COASTAL STORM WILL BE THE MAJOR FEATURE IN THE
LONG TERM WITH SIGNIFICANT IMPACTS ON SOUTHERN NEW ENGLAND THROUGH
THE WEEKEND AND INTO TUESDAY MORNING. THROUGHOUT THE REST OF THE
LONG TERM...A MID LEVEL RIDGE BUILDS OVER SOUTHERN NEW ENGLAND AND
QUIET...DRY WEATHER IS EXPECTED THROUGH THE MIDDLE OF THE WEEK.
SATURDAY NIGHT THROUGH MONDAY...LOW PRESSURE MOVES OFFSHORE NORTH
CAROLINA AND MOVES NORTHEAST TO NEAR THE 40/70 BENCHMARK. AS STATED
ABOVE...THERE ARE SOME DIFFERENCES IN THE MODELS BUT AM LEANING
TOWARDS THE GFS. ALL MODELS...INCLUDING THE ENSEMBLES...ARE
INDICATING A HIGH LIKELIHOOD OF 2 TO 4 INCHES OF RAIN ACROSS
SOUTHERN NEW ENGLAND. IN ADDITION...PWAT VALUES ARE 2 TO 3 STANDARD
DEVIATIONS ABOVE NORMAL...SO HEAVY RAIN IS LIKELY AT TIMES. DESPITE
HOW DRY ITS BEEN OVER THE LAST MONTH...JUST OVER AN INCH OF PRECIP
FOR THE MONTH OF MARCH...THIS AMOUNT OF RAIN OVER A 36 TO 48 HOUR
TIME FRAME IS LIKELY TO PRODUCE AT LEAST URBAN AND POOR DRAINAGE
FLOODING. RIVER BASINS HAVE A DECENT CAPACITY BECAUSE ITS BEEN
DRY...BUT WE WILL HAVE TO KEEP AN EYE ON THEM...PARTICULARLY IF WE
GET MORE THAN 2 TO 3 INCHES OF RAIN. WHILE MOST OF THE PRECIP IS
EXPECTED TO BE RAIN...AS THE LOW MOVES OUT TO SEA AND COOLER AIR
GETS DRAWN DOWN INTO THE REGION ON NORTHERLY FLOW...COULD SEE A
PERIOD OF WINTRY WEATHER MONDAY AS PRECIP COMES TO AN END. STILL
SOME UNCERTAINTY WITH THIS STORM SO WILL NEED TO KEEP AN EYE ON THE
MODEL TRENDS OVER THE NEXT DAY OR SO.
TUESDAY AND BEYOND...A MID LEVEL RIDGE BUILDS OVER THE NORTHEAST
WITH A HIGH LIKELIHOOD OF DRY WEATHER AND SEASONABLE TEMPERATURES.
THERE IS A LOW PROBABILITY OF SOME SHOWERS AS A COUPLE OF LOW
PRESSURE SYSTEMS MOVE THROUGH THE GREAT LAKES AND INTO QUEBEC.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
FORECAST CONFIDENCE THIS PERIOD IS MODERATE TO HIGH. CIGS AND
VSBYS BASED ON AN EVEN BLEND OF NAM/MET/GFS/MAV DATA SETS.
REMAINDER OF THE FORECAST WAS A BLEND OF ALL MODEL GUIDANCE. WIND
FORECAST MORE WEIGHTED TOWARD HI RES NAM.
TODAY...VFR TO START WITH CIGS SLOWLY LOWERING TO MVFR THIS
AFTERNOON IN SCATTERED SHOWERS. MAIN ISSUE TODAY WILL BE GUSTY SW
WINDS THIS AFTERNOON. G35 KT POSSIBLE OVER EASTERN MA WITH
G25-30KT ELSEWHERE. LESS SURFACE WIND ALONG THE SOUTH COAST
INCLUDING CAPE COD WHICH WILL RESULT IN LLWS WITH SW WIND 50-60 AT
2 KFT.
TONIGHT...FRONT SLIPS SOUTH OF NEW ENGLAND. MVFR/IFR SOUTH COAST
IMPROVING TO VFR LATE. ELSEWHERE MVFR IMPROVES TO VFR. ANY
LINGERING RAIN SHOWERS ON THE SOUTH COAST MOVE OFFSHORE LATER IN
THE EVENING.
SATURDAY...VFR AND DRY TO START BUT THEN LOWERING TO MVFR AS RAIN
OFF THE SOUTH COAST COMES ONSHORE LATER IN THE AFTERNOON FROM
SOUTH TO NORTH.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SW WINDS MAY GUSTS UP TO
35-40 KT THIS AFTERNOON.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT THROUGH MONDAY...MODERATE CONFIDENCE. AREAS OF MVFR
CIGS/VSBYS IN HEAVY RAIN/FOG. A WINTRY MIX IS POSSIBLE LATE SUNDAY
NIGHT INTO MONDAY AS PRECIP COMES TO AN END.
TUESDAY...MODERATE TO HIGH CONFIDENCE. IMPROVING CONDITIONS AS RAIN
MOVES OUT OF THE REGION.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE TO HIGH FORECAST CONFIDENCE THRU SAT NIGHT.
TODAY...
INCREASING SW WINDS AS COLD FRONT APPROACHES FROM THE WEST. SW WINDS
GUSTS TO 25-30 KT WITH STRONGEST WIND NEAR SHORE GIVEN WARM LAND
TEMPS. MODERATE RISK OF GUSTS 35-40 KT NORTH OF PLYMOUTH TO CAPE ANN
THIS AFTERNOON. THUS HAVE ISSUED A GALE WARNING FOR THIS AREA AND
SCA FOR ALL OTHER WATERS. SCATTERED RAIN SHOWERS.
TONIGHT...
COLD FRONT SLIPS OFFSHORE WITH WINDS DIMINISHING AND SHIFTING FROM
SW TO WNW BY MORNING.
SATURDAY...
WARM FRONT LIFTS NORTH WITH INCREASING SOUTH WINDS ACROSS THE SOUTH
OCEAN WATERS. RAIN ALSO OVERSPREADS SOUTHERN WATERS.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT THROUGH MONDAY...LOW TO MODERATE CONFIDENCE. GALE
WARNINGS WILL LIKELY BE NEEDED FOR SOME OF THE COASTAL WATERS AS LOW
PRESSURE MOVES OVER THE WATERS. SEAS INCREASE TO 10 TO 15 FEET ON
THE OUTER WATERS. VISIBILITIES WILL LIKELY BE LIMITED AT TIMES IN
HEAVY RAIN AND FOG.
TUESDAY...WINDS AND SEAS DIMINISH AS WEAK HIGH PRESSURE BEGINS TO
BUILD OVER THE WATERS.
&&
.TIDES/COASTAL FLOODING...
INCREASING SPRING TIDE WILL BE OCCURRING OVER THIS WEEKEND WITH
TIDES REACHING BETWEEN 11.2 AND 11.5 AT HIGH TIDE IN BOSTON. AS A
COASTAL STORM AFFECTS THE REGION OVER THE WEEKEND...WINDS WILL
GENERALLY BE IN A NORTHERLY TO NORTHEASTERLY DIRECTION. WITH THESE
WIND DIRECTIONS EXPECT THE MOST VULNERABLE COASTLINES WILL BE THE
NORTH FACING BEACHES OF CAPE COD AS WELL AS NANTUCKET.
HOWEVER...WITH THE EXPECTED STRENGTH OF THE WINDS AND AN UNCERTAIN
TRACK...COASTAL FLOODING IS POSSIBLE ALONG THE ENTIRE EAST COAST OF
MASSACHUSETTS. BEACH EROSION IS A CONCERN AS WELL GIVEN MULTIPLE
TIDE CYCLES WILL BE IMPACTED. THE MOST LIKELY TIDE CYCLES TO
RESULT IN FLOODING ARE THE SUNDAY NIGHT HIGH TIDE AND POSSIBLY THE
MONDAY MIDDAY HIGH TIDE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR ANZ231>234.
GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR ANZ230-251.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ235-237-
250-254>256.
&&
$$
SYNOPSIS...NOCERA/RLG
NEAR TERM...BELK/NOCERA/RLG
SHORT TERM...NOCERA
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN
MARINE...NOCERA/DUNTEN
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1041 AM EDT FRI MAR 28 2014
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL AS WEAK UPPER DISTURBANCES
MOVE THROUGH THE AREA TODAY AND TONIGHT. A COLD FRONT WILL CROSS
THE REGION SATURDAY AFTERNOON AND EVENING...FOLLOWED BY DRY HIGH
PRESSURE THROUGH THURSDAY. A COLD FRONT MAY AFFECT THE AREA NEXT
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATE THIS MORNING...CLOUDS HAVE STEADILY FILLED IN ACROSS THE
FORECAST AREA WITH MUCH OF IT BECOMING OVERCAST NOW. THERE ARE
STILL SOME BREAKS ON VISIBLE SATELLITE IMAGERY...BUT THESE SHOULD
FILL IN THROUGH THE DAY ESPECIALLY AS MID/HIGH CLOUDS STREAM IN
FROM ONGOING CONVECTION TO THE WEST. RADAR IMAGERY SHOWS PERIODIC
SHOWERS MOVING ONSHORE IN THE SOUTHERLY FLOW...MAINLY AFFECTING
CHARLESTON AND BERKELEY COUNTIES THIS MORNING. DIAGNOSING WHAT IS
CURRENTLY GOING ON AROUND THE REGION...THERE IS A FAIRLY LARGE
COMPLEX OF CONVECTION ONGOING ALONG THE GULF COAST FROM AROUND
NEW ORLEANS TO THE WESTERN FLORIDA PANHANDLE. BASED ON REGIONAL
RAOB/S THIS CONVECTION APPEARS TO BE ASSOCIATED WITH AN AREA OF
ELEVATED INSTABILITY. THIS IS FURTHER SUPPORTED BY NEGATIVE
SHOWALTER INDICES FROM THE RAP AND AN AREA OF ENHANCED MID LEVEL
LAPSE RATES NOTED FROM THE SPC MESOANALYSIS PAGE. FOR
INSTANCE...COMPARING THE 12Z KTLH AND KCHS SHOWS SIMILAR MID LEVEL
ENVIRONMENTS OTHER THAN THE PROMINENT SUBSIDENCE INVERSION NOTED
IN THE KCHS SOUNDING AT AROUND 650 MB. THIS INVERSION IS SUPPORTED
BY INTERROGATING ALL TILTS RADAR OF THE CURRENT SHOWER
ACTIVITY...WHICH SHOWS THE DEPTH OF REFLECTIVITY SHUTTING OFF
AROUND 11 KFT...WHICH IS NEAR THE 650 MB LEVEL. SO THE BEST MID
LEVEL ENVIRONMENT IS CERTAINLY TO OUR WEST AND SOUTHWEST AND BASED
ON CURRENT HI-RES MODEL RUNS IT APPEARS THAT WILL CONTINUE THROUGH
THE DAY. THE 11Z HRRR APPEARS TO BE HANDLING THE ONGOING
CONVECTION THE BEST...AND THROUGH THE DAY IT TAKES THE MOST
INTENSE UPSTREAM CONVECTION IN A SOUTHEASTWARD DIRECTION OVER THE
FLORIDA PANHANDLE AND THE EASTERN GULF. THIS SEEMS REASONABLE AS
THE BEST MID LEVEL ENVIRONMENT AND LATER SURFACE BASED INSTABILITY
WILL BE TO THE SOUTH AND SOUTHEAST OF ITS CURRENT LOCATION.
SO...FOR THE FORECAST AREA...THE THINKING IS THAT WE WILL CONTINUE
TO SEE SHALLOW CONVECTION AT BEST. I HAVE ADJUSTED POPS
ACCORDINGLY...AND THE SCHEME FAVORS THE EASTERN AREAS NOW AND THEN
THE WESTERN AREAS LATER AS THE DIMINISHING UPSTREAM
SHOWERS/CONVECTION ATTEMPT TO PUSH IN. WITH THE CLOUD COVER
ONGOING AND EXPECTED...HIGH TEMPERATURES ARE TRICKY. I HAVE
LOWERED VALUES MORE INTO THE LOW TO MID 70S...BUT THIS COULD BE ON
THE LOW END IF WE GET MORE SUN THAN EXPECTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
TONIGHT...ATLANTIC HIGH PRESSURE WILL PREVAIL AS A COLD FRONT
APPROACHES FROM THE TENNESSEE VALLEY AND DEEP SOUTH. SOUTHERLY
FLOW WILL CONTINUE TO ADVECT DEEP MOISTURE INTO THE REGION. THE
COMBINATION OF THE DEEP LAYERED MOISTURE...FORCING FOR ASCENT
ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL
JET...AND A POTENT SHORT WAVE PASSING ALOFT WILL SUPPORT SCATTERED
TO NUMEROUS SHOWERS ACROSS THE AREA...ESPECIALLY LATE THIS EVENING
AND OVERNIGHT. IN ADDITION...INSTABILITY PARAMETERS/MID LEVEL
LAPSE RATES ARE SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORMS AS
WELL. TEMPERATURES WILL NOT FALL SIGNIFICANTLY GIVEN THE SOUTHERLY
FLOW AND CLOUD COVER...WITH LOWS EXPECTED TO BE AROUND 60 IN MOST
AREAS.
A POTENT UPPER SHORTWAVE WILL MOVE INTO THE CENTRAL APPALACHIANS
ON SATURDAY. SOUTHWEST FLOW WILL STRENGTHEN CONSIDERABLY AS THE
DAY WEARS ON...WITH 0-6 KM WINDS 40-45 KT BY 00Z SUN. THIS WILL
ALSO INCREASE MOISTURE ACROSS THE AREA WITH PWATS ABOVE 1.50
INCHES BY 18Z SAT. A COLD FRONT IS EXPECTED TO SWEEP THROUGH THE
AREA SATURDAY EVENING. THERE REMAINS CONSIDERABLE UNCERTAINTY
REGARDING THE DEGREE OF BOUNDARY LAYER DESTABILIZATION AHEAD OF
THE FRONT. GIVEN THE EXTENSIVE LOW-LEVEL MOISTURE ADVECTING INTO
THE REGION DURING THE DAY WE WOULD EXPECT TO HAVE QUITE A BIT OF
LOW STRATOCUMULUS IN PLACE. HOWEVER SOME OF THE GUIDANCE IS
DEPICTING A WEAK DRY SLOT DURING THE MIDDAY HOURS AFTER A BATCH OF
MORNING PRECIP MOVES THROUGH. BOTH THE GFS AND NAM ARE SHOWING
1500 J/KG CAPES WITH LIFTED INDICES BELOW -4C DURING THE AFTERNOON
ACROSS SOUTHEAST GA. THIS COINCIDES WITH 40-45 KT OF BULK SHEAR.
IT IS ALSO WORTH NOTING THAT THE STORM PREDICTION CENTER STILL
SHOWS OUR ENTIRE FORECAST AREA WITHIN THE DAY 2 SLIGHT RISK. WE
PLAN TO ADD MENTION OF POSSIBLE SEVERE WEATHER TO THE HAZARDOUS
WEATHER OUTLOOK.
STRONG LOW-LEVEL WARM ADVECTION AND PRE-FRONTAL COMPRESSION ON
SATURDAY WILL PUSH HIGH TEMPS INTO THE UPPER 70S. THIS COULD
POTENTIALLY BE TOO COOL IF SOME BREAKS DEVELOP IN THE CLOUDS.
CONSIDERABLE COVERAGE OF SHOWERS AND THUNDERSTORMS IS EXPECTED
THROUGH SATURDAY EVENING BEFORE PRECIP TAPERS OFF BEHIND THE FRONT.
A SLIGHT COOL DOWN IS EXPECTED FOR SUNDAY DUE TO COLD ADVECTION WITH
THE HIGH BUILDING IN...HOWEVER DOWNSLOPE FLOW WILL ALLOW TEMPS TO
REACH 70 OR THEREABOUTS. A 30-35 KT GEOSTROPHIC WIND FIELD AND DEEP
MIXING WILL RESULT IN BREEZY CONDITIONS ESPECIALLY DURING THE HOURS
OF PEAK HEATING.
DRY WEATHER WITH MODERATING TEMPERATURES EXPECTED ON MONDAY WITH
HIGHS REBOUNDING INTO THE LOWER TO MIDDLE 70S.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A BROAD UPPER LEVEL RIDGE WILL PREVAIL MONDAY NIGHT THROUGH THURSDAY
WITH DRY HIGH PRESSURE AT THE SURFACE. THIS WILL RESULT IN ABOVE
NORMAL TEMPERATURES WITH HIGHS CLIMBING INTO THE UPPER 70S OR LOWER
80S AND LOWS MAINLY IN THE 50S. THE UPPER RIDGE BREAKS DOWN ON
FRIDAY WITH A WEAK COLD FRONT POSSIBLY MOVING IN FROM THE WEST.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS SHOULD GENERALLY PREVAIL AT BOTH KCHS AND KSAV
THROUGH AT LEAST THIS AFTERNOON. BRIEF/ISOLATED SHOWERS ARE
POSSIBLE AROUND KCHS THROUGH MUCH OF THE MORNING...BUT GIVEN
LIMITED COVERAGE AND OVERALL LOW CONFIDENCE...THERE WILL BE NO
MENTION IN THE KCHS TAF. BREEZY CONDITIONS WILL DEVELOP THIS
AFTERNOON WITH GUSTS UPWARDS OF 20 KT AT TIMES. INCREASING LOW
LEVEL MOISTURE AND A PASSING UPPER LEVEL DISTURBANCE WILL RESULT
IN SCATTERED TO NUMEROUS SHOWERS AND PERHAPS A FEW THUNDERSTORMS
LATER THIS AFTERNOON INTO TONIGHT. AS A RESULT...HAVE ADDED VICINITY
SHOWERS TO THE TAF/S BEGINNING EARLY THIS AFTERNOON...THEN
PREVAILING SHOWERS LATE THIS AFTERNOON THROUGH THIS EVENING.
CEILINGS COULD PERIODICALLY LOWER TO MVFR LEVELS LATE THIS AFTERNOON AND
THIS EVENING...ESPECIALLY IN SHOWERS. THEN...MVFR CEILINGS WILL
BECOME MORE PREVALENT AFTER MIDNIGHT AT BOTH TERMINALS...WITH EVEN
A LOW PROBABILITY OF IFR CEILINGS DEVELOPING AT KSAV.
EXTENDED AVIATION OUTLOOK...OCCASIONAL FLIGHT RESTRICTIONS POSSIBLE
SATURDAY AFTERNOON AND EVENING IN SCATTERED SHOWERS AND
THUNDERSTORMS. VFR CONDITIONS EXPECTED THEREAFTER. BREEZY CONDITIONS
EXPECTED ON SUNDAY.
&&
.MARINE...
TODAY...A SOUTHERLY RETURN FLOW WILL BECOME WELL ESTABLISHED
ACROSS THE COASTAL WATERS TODAY AS ATLANTIC HIGH PRESSURE
PREVAILS. DESPITE SOME STRONGER WINDS ALOFT...MIXING WILL REMAIN
LIMITED OVER THE COOLER NEAR SHORE WATERS THUS WINDS AT THE
SURFACE SHOULD NOT EXCEED 10 TO 15 KT. HOWEVER...WINDS OVER THE
OUTER GA WATERS AND IN CHARLESTON HARBOR ALONG THE LAND/SEA
INTERFACE COULD REACH UPWARDS OF 15 TO 20 KT AT TIMES THIS
AFTERNOON. A SOUTHEAST SWELL WILL KEEP SEAS ELEVATED IN THE 3-5 FT
RANGE TODAY...WITH A SMALL POTENTIAL FOR SOME 6 FT SEAS TO
ENCROACH UPON THE FAR REACHES OF THE OUTER GA WATERS. GIVEN
LIMITED CONFIDENCE...HAVE OPTED TO NOT ISSUE A SMALL CRAFT
ADVISORY...ALTHOUGH CONDITIONS COULD WARRANT OTHERWISE LATER
TODAY. DEW POINTS SURGING INTO THE LOWER 60S WITHIN THE SOUTHERLY
FLOW COULD SUPPORT THE DEVELOPMENT OF PATCHY SEA FOG LATER THIS
AFTERNOON ACROSS THE NEAR SHORE WATERS.
TONIGHT...THE SOUTHERLY FLOW WILL STRENGTHEN TO UPWARDS OF 15 TO
20 KT ACROSS THE COASTAL WATERS AS THE SURFACE PRESSURE GRADIENT
TIGHTENS BETWEEN ATLANTIC HIGH PRESSURE AND A COLD FRONT WELL TO
THE WEST. A SOUTHEAST SWELL WILL KEEP SEAS SOLIDLY IN THE 3-5 FT
RANGE...HIGHEST ACROSS THE OUTER GA WATERS. THERE IS A SMALL
POTENTIAL THAT MARGINAL SMALL CRAFT ADVISORY CONDITIONS FOR WINDS
AND/OR SEAS COULD OCCUR OVER THE OUTER GA WATERS...BUT NOT ENOUGH
CONFIDENCE TO RAISE AN ADVISORY AT THIS TIME. THE POTENTIAL FOR
PATCHY SEA FOG WILL PERSIST TONIGHT ACROSS THE NEAR SHORE WATERS
AND CHARLESTON HARBOR AS A WARM/MOIST SOUTHERLY FLOW PREVAILS.
SATURDAY THROUGH TUESDAY...WIND FIELDS WILL INCREASE SATURDAY INTO SATURDAY
NIGHT AS A STRONG COLD FRONT MOVES THROUGH. ON SATURDAY THE FLOW
WILL BE OUT OF THE SOUTH AND CONDITIONS SHOULD REMAIN BELOW
ADVISORY CRITERIA. BUT ONCE COLD ADVECTION CRANKS UP LATE SATURDAY
EVENING AND OVERNIGHT AND GEOSTROPHIC WINDS INCREASE TO 35-40
KT...WE EXPECT SMALL CRAFT ADVISORY CONDITIONS ON MOST IF NOT ALL
MARINE ZONES. CONDITIONS WILL QUICKLY IMPROVE ON SUNDAY AS THE
HIGH PRESSURE CENTER MOVES CLOSER TO THE WATERS. FAIRLY QUIET
WINDS/SEAS ANTICIPATED SUNDAY NIGHT THROUGH MID WEEK AS THE HIGH
PRESSURE DOMINATES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...JAQ/JRL
MARINE...JAQ/JRL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1040 AM EDT FRI MAR 28 2014
.UPDATE...
HAVE MADE SIGNIFICANT ADJUSTMENTS TO THE FORECAST TO ACCOUNT FOR
LATEST THINKING WITH TODAYS WEATHER. AXIS OF PRECIPITATION IS
FURTHER SOUTH THAN ORIGINALLY ANTICIPATED...AND PREVIOUS FORECAST
POP AND WX GRIDS DID NOT MATCH THIS POSITIONING.
OVERALL...MODEL GUIDANCE WITH THIS SYSTEM IS POOR...WITH VERY FEW
DEPICTING THE CURRENT RADAR TRENDS WELL. HAVE OVERALL GONE WITH
THE HRRR WHICH SEEMS TO HAVE A BETTER HANDLE ON THE CURRENT
CONDITIONS. THE HRRR DOES SUGGEST MUCH OF THE COMPLEX IN MS/AL
WILL ORGANIZE INTO THIS AFTERNOON...BECOMING MORE LINEAR IN
NATURE...AND PUSHING ACROSS SOUTHWEST GEORGIA. ALTHOUGH THERE IS A
QUESTION OF WHETHER THIS LINEAR CONVECTION WILL MATERIALIZE...THE
HRRR CONTINUES TO SHOW MUCH OF NORTH GEORGIA CUT OFF FROM GULF
MOISTURE...AND LIMITS THE AMOUNT OF PRECIP OVER THE NORTHERN
SECTIONS OF THE CWA. AS A RESULT...HAVE CONTINUED THE TREND OF
HIGHEST POPS ACROSS CENTRAL GEORGIA INTO THE OVERNIGHT PERIOD.
WILL CONTINUE TO UPDATE THE GRIDS AS NECESSARY...ESPECIALLY THE
NEXT 24 HOURS.
31
.PREV DISCUSSION... /ISSUED 717 AM EDT FRI MAR 28 2014/
PREV DISCUSSION... /ISSUED 341 AM EDT FRI MAR 28 2014/
SHORT TERM /TODAY THROUGH SATURDAY/...
SURFACE ANALYSIS SHOWS A COLD FRONT STRETCHING FROM THE CENTRAL
GREAT LAKES BACK THROUGH THE ARKLATEX. A LARGE AREA OF PRECIPITATION
HAS DEVELOPED TO THE EAST OF THE BOUNDARY AN IS MOVING INTO NW
PORTIONS OF THE CWFA. PRECIP WILL CONTINUE TO INCREASE FOR MUCH OF
THE AREA TODAY AS THE FRONT SLOWLY PUSHES EASTWARD.
THE NORTHERN END OF THE FRONT WILL MAKE SOME EASTWARD PROGRESS
TODAY...WHILE THE SOUTHERN END WILL LAG UNTIL EARLY SATURDAY
MORNING. A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE SOUTHERN TAIL
OF THE FRONT TONIGHT...AND FINALLY HELP PUSH THE FRONT THROUGH THE
CWFA ON SATURDAY. THE NORTHERN END OF THE FRONT WILL BECOME
TEMPORARILY STATIONARY NEAR THE TN/GA BORDER THIS EVENING AND
OVERNIGHT. EXPECT SHOWERS AND A FEW THUNDERSTORMS TO TRAIN ACROSS
THE NORTHERN HALF OF THE CWFA...IN THE VICINITY OF THE BOUNDARY
TONIGHT.
MODELS SHOWING A BIT MORE INSTABILITY ACROSS THE SOUTHERN CWFA FOR
THIS AFTERNOON THAN IN PREVIOUS RUNS. STILL...ONLY A COUPLE HUNDRED
JULES OF CAPE. WILL KEEP THUNDER CHANCES AT A MINIMUM TODAY AND ONLY
MENTION A SLIGHT CHANCE. EVEN THOUGH A BREAK IN THE WIDESPREAD
PRECIPITATION IS EXPECTED THIS EVENING...THE CHANCES FOR THUNDER
WILL SLIGHTLY INCREASE AS A MID LEVEL SHORTWAVE TRAVERSES THE AREA
AND STEEPENS LAPSE RATES. STILL...SURFACE INSTABILITY WILL BE
LIMITED...SO WILL CAP THE THUNDER WORDING AT A CHANCE. A BIT MORE
INSTABILITY WILL BE PRESENT SATURDAY AFTERNOON...ESPECIALLY ACROSS
THE SOUTHEAST PORTION OF THE CWFA. THIS AREA HAS THE POTENTIAL FOR
SOME HEATING...WITH TEMPS IN THE LOWER TO MIDDLE 70S. SURFACE BASED
CAPES SHOULD RANGE FROM 500 TO 1000 J/KG. THE BEST SHEAR SHOULD
LAG...ALONG WITH THE FRONTAL BOUNDARY. HOWEVER...WILL NOT RULE OUT
STRONG THUNDERSTORMS WITH ISOLATED SEVERE STORMS POSSIBLE. DAMAGING
WIND GUSTS SHOULD BE THE PRIMARY MODE OF SEVERE WEATHER.
NLISTEMAA
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
FOR THE MOST PART...SYSTEM THAT BRINGS RAIN TO THE AREA IN THE
SHORT TERM SHOULD HAVE EXITED THE AREA BY THE BEGINNING OF THE
LONG TERM. THE EXCEPTION TO THIS IS ACROSS FAR NORTHEAST GEORGIA
AND THE FAR SOUTHEAST PART OF THE CWA WHERE SOME RAIN COULD LINGER
THROUGH SATURDAY NIGHT. AT THIS POINT...IT APPEARS THE
PRECIPITATION SHOULD END ACROSS THE NE GA MOUNTAINS BEFORE THE
COOLER TEMPERATURES MOVE IN. AFTER THIS HIGH PRESSURE WILL
DOMINATE THROUGH ABOUT MID WEEK. BOTH THE GFS AND THE ECMWF
SUGGEST THE NEXT SYSTEM MOVING THROUGH IN THE LATER HALF OF THE
WEEK. INSTABILITY VALUES SUPPORT THE MENTION OF THUNDER IN THE
FORECAST THURSDAY INTO FRIDAY.
11
HYDROLOGY...
ONE CONCERN FOR THE FORECAST PERIOD IS LOCALLY HEAVY RAINFALL. PWATS
JUST UNDER AN INCH AND HALF WILL BE LIKELY THIS AFTERNOON THROUGH
SATURDAY. THESE NUMBERS ARE VERY CLOSE TO BEING 2SD ABOVE NORMAL FOR
THIS TIME OF YEAR. 6HR FFG GUIDANCE RANGES FROM AROUND 2 TO 3
INCHES ACROSS THE CWFA. STORM TOTAL PRECIP FROM TODAY THROUGH
SATURDAY NIGHT AVERAGES AN INCH AND A HALF TO JUST ABOUT TWO AND
THREE QUARTERS OF AN INCH. SINCE THE RAINFALL IS EXPECTED TO BE OVER
A LONGER PERIOD OF TIME...FF ISN`T A MAJOR CONCERN AT THIS TIME.
HOWEVER...WHERE THUNDERSTORMS REPEATEDLY TRAIN...SOME LOCALIZED FF
IS POSSIBLE. DO EXPECT SOME RISES ON THE RIVERS BUT NOT CONFIDENT
ENOUGH TO SAY IF RIVERS WILL GO INTO FLOOD YET.
NLISTEMAA
AVIATION...
12Z UPDATE...
RAIN HAS STARTED TO OVERSPREAD THE METRO AREA THIS MORNING AHEAD
OF A COLD FRONT ACROSS THE ARKLATEX. A BREAK IN THE PRECIP IS
EXPECTED THIS EVENING...BUT PRECIP WILL FILL IN AGAIN EARLY FRIDAY
AS THE COLD FRONT MOVES THROUGH. MODELS ARE PROGGING IFR CIGS WITH
THE WIDESPREAD RAIN TODAY...AND THINK THAT IS REASONABLE. CIGS MAY
END UP LOWER THAN FORECAST OVERNIGHT...BUT FOR NOW WILL KEEP LOWEST VALUES
AROUND 500FT. WINDS WILL REMAIN OUT OF THE SE.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON IFR CIGS. HIGH CONFIDENCE REMAINING
ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 64 55 69 40 / 100 80 70 10
ATLANTA 63 57 66 41 / 100 70 70 5
BLAIRSVILLE 56 52 60 35 / 100 80 60 20
CARTERSVILLE 62 57 65 40 / 100 80 70 5
COLUMBUS 67 60 72 45 / 100 50 60 5
GAINESVILLE 59 54 64 39 / 100 80 70 5
MACON 69 59 73 42 / 90 50 60 10
ROME 62 57 64 40 / 100 80 70 5
PEACHTREE CITY 64 57 68 38 / 100 70 70 5
VIDALIA 76 61 75 47 / 60 40 70 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....BAKER
AVIATION...31
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
756 AM EDT FRI MAR 28 2014
.SYNOPSIS...
MOISTURE WILL BE HIGH AHEAD OF A SLOW MOVING FRONTAL SYSTEM. THE
FRONT WILL MOVE THROUGH THE FORECAST AREA LATE SATURDAY. HIGH
PRESSURE AND DRIER CONDITIONS WILL PREVAIL SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...A MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SHOULD HELP SUPPORT
SHOWERS TODAY. THE NAM AND GFS MOS PLUS RADAR TRENDS SUPPORT HIGH
POPS. BASED TIMING ON RADAR TRENDS AND THE LATEST HRRR. CLOUDINESS
AND SHOWERS SHOULD LIMIT INSTABILITY. THE NAM INDICATES JUST WEAK
INSTABILITY. THE HRRR AND SATELLITE TRENDS SUPPORT KEEPING THE
STRONGER CONVECTION SOUTH OF THE FORECAST AREA. EXPECT MAINLY
SHOWERS INSTEAD OF THUNDERSTORMS. USED THE COOLER TEMPERATURE
GUIDANCE BECAUSE OF CLOUDINESS.
TONIGHT...THE MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SUPPORT
CONTINUED HIGH POPS TONIGHT. COVERAGE MAY INCREASE TOWARD MORNING
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. COOLING ALOFT ASSOCIATED
WITH THE UPPER TROUGH SUPPORTS A HIGHER CHANCE OF THUNDERSTORMS
TOWARD MORNING. SHEAR WILL BE ON THE INCREASE INDICATING WELL-
ORGANIZED THUNDERSTORMS MAY OCCUR BUT THE NAM SUGGESTS ANY
SURFACE-BASED INSTABILITY WILL REMAIN WEAK THROUGH THE NIGHT. THE
DIURNAL TIMING SHOULD ALSO HELP LIMIT INSTABILITY. THEREFORE...THE
RISK OF SEVERE THUNDERSTORMS APPEARS LOW AT THIS TIME. THE WARMER
TEMPERATURE GUIDANCE APPEARS BETTER BECAUSE OF CLOUDINESS.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
SATURDAY...MOISTURE SHOULD BE HIGH AHEAD OF THE COLD FRONT
SATURDAY. THE NAM INDICATES THE DEEPEST MOISTURE EARLY SATURDAY.
THE GFS AND ECMWF SHOW THE DEEPEST MOISTURE AROUND THE MIDDLE OF
THE DAY AHEAD OF THE COLD FRONT. THE MODELS WERE MORE CONSISTENT
WITH COLD FRONTAL PASSAGE LATE IN THE DAY OR EVENING. WE
MAINTAINED LIKELY POPS DURING MUCH OF THE DAY WITH THE TIMING
DIFFICULT BECAUSE ISENTROPIC LIFT APPEARS GREATER IN THE
MORNING...BUT CONVERGENCE AHEAD OF THE COLD FRONT SHOULD BE HIGHER
DURING THE AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE H85
WINDS OF 35 TO 40 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S NEAR
-3 DURING THE AFTERNOON. THERE WILL BE A THREAT OF SEVERE
THUNDERSTORMS BECAUSE OF THIS SHEAR AND INSTABILITY. ANY LINGERING SHOWERS
AND THUNDERSTORMS SHOULD END FROM WEST TO EAST SATURDAY EVENING
AS DRYING BECOMES DOMINATE BEHIND THE COLD FRONT. WE USED THE
GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE
DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE
IN THE PERIOD AHEAD OF A COLD FRONT. THE COOLEST NIGHT SHOULD BE
SUNDAY NIGHT. STRONG NOCTURNAL COOLING SHOULD OCCUR WITH DRY HIGH
PRESSURE OVERHEAD AND LIGHT WINDS. AN AVERAGE OF THE GFS...ECMWF
AND EKD MOS SUPPORTS LOWS MAINLY IN THE UPPER 30S. FROST WILL BE
POSSIBLE MAINLY IN THE NORMALLY COLDER LOCATIONS. WARMER
TEMPERATURES SHOULD OCCUR BEGINNING MONDAY AS THE HIGH SHIFTS
EASTWARD AND THE AIR MASS CONTINUES TO MODIFY. THE GFS...ECMWF...
AND EKD MOS SUPPORT HIGHS IN THE UPPER 70S TO AROUND 80 TUESDAY
THROUGH THURSDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
REGIONAL RADAR LOOP SHOWS AN AREA OF SHOWERS IN THE UPSTATE AND
SHOWERS AND A FEW THUNDERSTORMS EXTENDING SOUTHWESTWARD THROUGH
GEORGIA. SHOULD SEE AT LEAST SCATTERED SHOWERS REACHING THE TAF
SITES BY MIDDAY...BUT BETTER CHANCE DURING THE AFTERNOON INTO THE
EVENING HOURS. CURRENT OBSERVATIONS SHOW MAINLY VFR CONDITIONS IN
THE UPSTATE WHICH INCREASES CONFIDENCE THAT TAF SITES MAY REMAIN
VFR THROUGH MUCH OF THE MORNING. LAMP GUIDANCE INDICATES
CONDITIONS DETERIORATING TO MVFR EARLY THIS AFTERNOON AND
REMAINING MVFR OR IFR THROUGH THE END OF THE TAF PERIOD...WHILE
NAM INDICATES A PERIOD OF CIGS ABOVE 3000 FEET DURING THE
EARLY AFTERNOON HOURS. WILL LEAN A BIT MORE TOWARDS THE MORE
PESSIMISTIC LAMP FORECAST.
LATEST CAE VWP SHOWING 40 KT WIND AROUND 2 KFT EARLY THIS
MORNING...WITH LIGHT WINDS AT THE SURFACE. WILL MENTION LLWS FOR ALL
TAF SITES UNTIL AROUND 15Z THIS MORNING.
EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS EXPECTED SATURDAY
AHEAD OF A COLD FRONT THAT WILL CROSS THE AREA LATE SATURDAY
AFTERNOON. BREEZY CONDITIONS IN THE WAKE OF THE FRONT SATURDAY
NIGHT INTO SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
641 AM EDT FRI MAR 28 2014
.SYNOPSIS...
MOISTURE WILL BE HIGH AHEAD OF A SLOW MOVING FRONTAL SYSTEM. THE
FRONT WILL MOVE THROUGH THE FORECAST AREA LATE SATURDAY. HIGH
PRESSURE AND DRIER CONDITIONS WILL PREVAIL SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...A MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SHOULD HELP SUPPORT
SHOWERS TODAY. THE NAM AND GFS MOS PLUS RADAR TRENDS SUPPORT HIGH
POPS. BASED TIMING ON RADAR TRENDS AND THE LATEST HRRR. CLOUDINESS
AND SHOWERS SHOULD LIMIT INSTABILITY. THE NAM INDICATES JUST WEAK
INSTABILITY. THE HRRR AND SATELLITE TRENDS SUPPORT KEEPING THE
STRONGER CONVECTION SOUTH OF THE FORECAST AREA. EXPECT MAINLY
SHOWERS INSTEAD OF THUNDERSTORMS. USED THE COOLER TEMPERATURE
GUIDANCE BECAUSE OF CLOUDINESS.
TONIGHT...THE MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SUPPORT
CONTINUED HIGH POPS TONIGHT. COVERAGE MAY INCREASE TOWARD MORNING
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. COOLING ALOFT ASSOCIATED
WITH THE UPPER TROUGH SUPPORTS A HIGHER CHANCE OF THUNDERSTORMS
TOWARD MORNING. SHEAR WILL BE ON THE INCREASE INDICATING WELL-
ORGANIZED THUNDERSTORMS MAY OCCUR BUT THE NAM SUGGESTS ANY
SURFACE-BASED INSTABILITY WILL REMAIN WEAK THROUGH THE NIGHT. THE
DIURNAL TIMING SHOULD ALSO HELP LIMIT INSTABILITY. THEREFORE...THE
RISK OF SEVERE THUNDERSTORMS APPEARS LOW AT THIS TIME. THE WARMER
TEMPERATURE GUIDANCE APPEARS BETTER BECAUSE OF CLOUDINESS.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
SATURDAY...MOISTURE SHOULD BE HIGH AHEAD OF THE COLD FRONT
SATURDAY. THE NAM INDICATES THE DEEPEST MOISTURE EARLY SATURDAY.
THE GFS AND ECMWF SHOW THE DEEPEST MOISTURE AROUND THE MIDDLE OF
THE DAY AHEAD OF THE COLD FRONT. THE MODELS WERE MORE CONSISTENT
WITH COLD FRONTAL PASSAGE LATE IN THE DAY OR EVENING. WE
MAINTAINED LIKELY POPS DURING MUCH OF THE DAY WITH THE TIMING
DIFFICULT BECAUSE ISENTROPIC LIFT APPEARS GREATER IN THE
MORNING...BUT CONVERGENCE AHEAD OF THE COLD FRONT SHOULD BE HIGHER
DURING THE AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE H85
WINDS OF 35 TO 40 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S NEAR
-3 DURING THE AFTERNOON. THERE WILL BE A THREAT OF SEVERE
THUNDERSTORMS BECAUSE OF THIS SHEAR AND INSTABILITY. ANY LINGERING SHOWERS
AND THUNDERSTORMS SHOULD END FROM WEST TO EAST SATURDAY EVENING
AS DRYING BECOMES DOMINATE BEHIND THE COLD FRONT. WE USED THE
GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE
DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE
IN THE PERIOD AHEAD OF A COLD FRONT. THE COOLEST NIGHT SHOULD BE
SUNDAY NIGHT. STRONG NOCTURNAL COOLING SHOULD OCCUR WITH DRY HIGH
PRESSURE OVERHEAD AND LIGHT WINDS. AN AVERAGE OF THE GFS...ECMWF
AND EKD MOS SUPPORTS LOWS MAINLY IN THE UPPER 30S. FROST WILL BE
POSSIBLE MAINLY IN THE NORMALLY COLDER LOCATIONS. WARMER
TEMPERATURES SHOULD OCCUR BEGINNING MONDAY AS THE HIGH SHIFTS
EASTWARD AND THE AIR MASS CONTINUES TO MODIFY. THE GFS...ECMWF...
AND EKD MOS SUPPORT HIGHS IN THE UPPER 70S TO AROUND 80 TUESDAY
THROUGH THURSDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS LOW-LEVEL MOISTURE INCREASES...MODEL GUIDANCE SUGGESTING MVFR
CIGS DEVELOPING EARLY THIS MORNING. THERE IS THE POSSIBILITY OF IFR
CEILINGS AROUND SUNRISE...BUT CONFIDENCE TOO LOW TO INCLUDE. SHOULD
SEE AT LEAST SCATTERED SHOWERS DEVELOPING BY MIDDAY...BUT BETTER
CHANCE DURING THE AFTERNOON INTO THE EVENING HOURS. LAMP GUIDANCE
INDICATE MVFR CIGS CONTINUING THROUGH THE END OF THE TAF
PERIOD...WHILE NAM INDICATES A PERIOD OF CIGS ABOVE 3000 FEET DURING
THE AFTERNOON HOURS. WILL LEAN A BIT MORE TOWARDS THE MORE
PESSIMISTIC LAMP FORECAST.
LATEST CAE VWP SHOWING 40 KT WIND AROUND 2 KFT EARLY THIS
MORNING...WITH LIGHT WINDS AT THE SURFACE. WILL MENTION LLWS FOR ALL
TAF SITES UNTIL AROUND 15Z THIS MORNING.
EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS EXPECTED FRIDAY
NIGHT INTO SATURDAY AHEAD OF COLD FRONT THAT WILL CROSS THE AREA LATE
SATURDAY AFTERNOON. BREEZY CONDITIONS IN THE WAKE OF THE FRONT
SATURDAY NIGHT INTO SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1018 AM CDT FRI MAR 28 2014
.DISCUSSION...
1018 AM CDT
HAVE MADE SOME ADJUSTMENTS TO SKY GRIDS TODAY TO BE A BIT LESS
OPTIMISTIC WITH CLEARING. LOW LEVEL MOISTURE/STRATUS IS CURRENTLY
TRAPPED UNDER A FAIRLY SHARP INVERSION AND INVERSION IS LIKELY TO
PERSIST NOT OFFERING MUCH HOPE FOR BETTER MIXING. CLEARING LINE
OVER CENTRAL WISCONSIN IS MAKING FAIRLY QUICK PROGRESS SOUTHWARD
AND WILL PROBABLY MAKE IT INTO AT LEAST OUR NORTHERN CWA THIS
AFTERNOON...THOUGH WITH LOW LEVEL FLOW SLACKENING THIS AFTERNOON
AND VEERING NE WOULD EXPECT THIS CLEARING LINE TO SLOW DOWN A BIT.
ASSUMING CLOUD COVER LINGERS INTO THE AFTERNOON...TEMPERATURES
WILL BE SLOW TO RECOVER AND HAVE SHAVED A FEW DEGREES OFF GOING
HIGH TEMPS.
UPDATED GRIDS/TEXT PRODUCTS HAVE BEEN SENT.
IZZI
&&
.PREV DISCUSSION...
323 AM CDT
TODAY...
SURFACE COLD FRONT IS CLEARING THE EASTERN COUNTIES IN THE CWA EARLY
THIS MORNING WHILE A SECONDARY TROUGH IS DIGGING ACROSS NORTHERN
ILLINOIS WITH WINDS TURNING SHARPLY TO THE NNW WITH GUSTS WELL INTO
THE 20 KT RANGE. SHOWERS BEHIND THIS TROUGH WILL SWEEP ACROSS
NORTHERN ILLINOIS AND NORTHWEST INDIANA...EXITING TO THE EAST BY MID
TO LATE MORNING. BREEZY CONDITIONS THIS MORNING SHOULD GRADUALLY
TAPER THROUGH THE DAY AS THE AS THE LOW LIFTS TOWARDS QUEBEC AND
FILLS. TEMPS INTO THE MID TO UPPER 40S ARE EXPECTED THIS
AFTERNOON...BUT A LAKE BREEZE WILL TURN WINDS NORTHEASTERLY AND COOL
TEMPS BACK INTO THE 30S ALONG THE LAKE.
THIS WEEKEND...
LOW PRESSURE WILL LIFT FROM ARKLATEX INTO THE UPPER OHIO VALLEY BY
MIDDAY SATURDAY. BEST CHANCES FOR PRECIP WILL BE SOUTH OF I-80
ESPECIALLY IN NORTHWEST INDIANA...AND FOR NOW IT APPEARS AREAS NORTH
WILL REMAIN DRY. GFS INDICATES WET BULBS DROPPING BELOW ZERO THROUGH
THE COLUMN AROUND OR BEFORE THE ONSET OF PRECIP INDICATE ALL SNOW.
NAM SOUNDINGS ON THE OTHER HAND SHOW SLIGHTLY WARMER TEMPS ALOFT
HINTING AT THE POSSIBILITY FOR RAIN/SNOW MIX...THOUGH SREF P-TYPE
PROBABILITY INDICATES BETTER CHANCES FOR SNOW. COMING OFF HIGHS IN
THE UPPER 40S IN AREAS MOST LIKELY TO SEE PRECIP...AND OVERNIGHT
LOWS SOUTH OF 80 AT OR EVEN SLIGHTLY ABOVE FREEZING...THE LIKELIHOOD
OF ACCUMULATING SNOW IS LOW AND WOULD LIKELY BE CONFINED TO THE
GRASS. IN ADDITION...GIVEN THE MARGINAL SOUNDINGS...SNOW PRODUCTION
WOULD BE INEFFICIENT. WILL MAINTAIN RAIN/SNOW MIX IN THE FORECAST
FOR NOW GIVEN THE CURRENT UNCERTAINTY.
HIGH PRESSURE WILL THEN TRANSLATE ACROSS THE REGION OVER THE
REMAINDER OF THE WEEKEND RESULTING IN DRY WEATHER FROM SATURDAY
AFTERNOON ON. H85 THERMAL TROUGH WILL APPROACH THE REGION ON
SATURDAY...THOUGH SUBSIDENCE ALOFT SETTLING OVER THE UPPER MIDWEST
THROUGH THE DAY SATURDAY WILL RESULT IN DRYING AND WARMING OF THE
MID LEVELS WHICH WILL HELP MODULATE THE COLDER AIRMASS MOVING
OVERHEAD. WITH AFTERNOON SUNSHINE...EXPECT AREAS AWAY FROM THE LAKE
TO RISE INTO THE MID TO UPPER 40S AGAIN...WITH A FEW 50S MAINLY
SOUTH OF I-80. ALONG THE LAKE FRONT...A BREEZE OFF THE LAKE THROUGH
THE DAY WILL KEEP TEMPERATURES MUCH COOLER...IN THE MID 30S. THE
SURFACE RIDGE AXIS WILL PASS OVERHEAD SATURDAY NIGHT...AND SOUTHERLY
FLOW WILL RAMP UP THROUGH THE DAY SUNDAY AHEAD OF OUR NEXT AREA OF
LOW PRESSURE STARTING TO TAKE SHAPE OVER THE PLAINS. STRONG WARM
ADVECTION IS EXPECTED THROUGH THE DAY SUNDAY WHICH WILL RESULT IN
H85 TEMPS RISING TO AROUND 10C BY SUNDAY EVENING. SOUTHERLY WINDS
MAY TAKE ON A SLIGHT WESTERLY COMPONENT BY SUNDAY AFTERNOON...IN THE
190-200 DIRECTION...WHICH WITH THE INCREASING WINDS SHOULD HELP
STAVE OFF ANY LAKE BREEZE/LAKE COOLING SUNDAY. NAM/GFS SOUNDINGS
SHOW LOW TO MID 20 KT GUSTS POSSIBLE BY SUNDAY AFTERNOON.
TEMPERATURES SHOULD RISE TO AROUND 60 RIGHT UP TO THE LAKE FRONT
SUNDAY AFTERNOON.
MONDAY...
AFOREMENTIONED SURFACE LOW PROGGED TO LIFT FROM THE MID MISSOURI
VALLEY EARLY MONDAY INTO MN/WI MONDAY EVENING. LATEST GUIDANCE IN
DECENT AGREEMENT ON THE LOCAL AREA GETTING FULL WARM SECTOR ON
MONDAY. LEANED TOWARD WARMER SIDE OF GUIDANCE MONDAY WITH A BLEND OF
BIAS CORRECTED GEM AND ECMWF. THIS RESULTS IN LOW TO MID 60S AREA
WIDE MONDAY AFTERNOON...AND WITH A MODERATE-STRONG SSW WIND...DO NOT
ANTICIPATE ANY COOLING ALONG THE LAKE. A 60-70KT LOW LEVEL JET
FOCUSES STRONG CONVERGENCE ACROSS THE MID MISSOURI VALLEY SUNDAY
NIGHT...THEN AT 40-50 KT REFOCUSES TO OUR NORTH MONDAY
EVENING/NIGHT. ACROSS NORTHERN ILLINOIS IN THE WARM SECTOR...
INSTABILITY IS PRETTY MEAGER WITH A STRONG CAP IN PLACE...THOUGH
SOME DYNAMIC COOLING ASSOCIATED WITH NEGATIVELY TILTED H5 WAVE AND
EXIT REGION OF UPPER JET MAY RESULT IN SOME SCATTERED CONVECTION.
ALL-IN-ALL THOUGH...GIVEN THE UNFAVORABLE TIMING OF THE FRONT
OVERNIGHT...NOT TOO IMPRESSED WITH PRECIP CHANCES MONDAY AND TRIMMED
POPS FOR THIS PERIOD.
TUESDAY THROUGH THURSDAY...
PRETTY LOW CONFIDENCE IN THE DETAILS AT THIS POINT...BUT TUESDAY
THROUGH THURSDAY SHOULD BE AN ACTIVE PERIOD WITH A SERIES OF
DISTURBANCES MOVING ACROSS THE REGION. THERE REMAINS SIGNIFICANT
DIFFERENCES AT THIS POINT BETWEEN MODELS WITH RESPECT TO THE LOW
TRACK WHICH WILL DETERMINE TEMPS AND PRECIP TYPE. GFS INDICATES A
FASTER MORE SOUTHERLY LOW WHILE THE ECMWF HINTS AT A WARMER SOLUTION
WITH A DEEPER LOW THAT TRACKS FARTHER NORTH. FOR NOW...STAYED CLOSE
TO A CONSENSUS BLEND.
TUBELESS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* NORTHWEST WINDS TURNING NORTH TOWARD MIDDAY AND NORTHEAST THIS
AFTERNOON.
* MVFR CIGS AROUND 015 GRADUALLY LIFTING TOWARD 020-025 INTO THE
AFTERNOON.
MDB
//DISCUSSION...UPDATED 14Z...
PRECIP HAS CLEARED THE TERMINALS LEAVING AN EXPANSIVE AREA OF MVFR
CLOUD COVER IN THE 012-020 RANGE WHICH WILL LIKELY CONTINUE INTO
THE AFTERNOON...THOUGH MAY SEE SCATTERING DEVELOP ON ITS FRINGES
INTO MIDDAY. OTHERWISE NORTHWEST WINDS WILL TURN NORTHERLY INTO
MIDDAY THEN NORTHEAST THIS AFTERNOON.
MDB
FROM 12Z...
RAIN SHOWERS WITH POCKETS OF IFR WRAPPING AROUND THE BACK SIDE OF
A DEPARTING LOW WILL CLEAR THE AREA BY MID MORNING. WINDS HAVE
TURNED NORTHWEST AND WILL CONTINUE TO VEER AROUND TO NORTHEAST BY
THE AFTERNOON. NOT CERTAIN ABOUT TIMING OF CHANGE OVER TO AN
EASTERLY COMPONENT BUT BEST ESTIMATE IS AROUND NOON OR SHORTLY
AFTER. LINGERING MVFR CIGS LATE THIS MORNING WILL EVENTUALLY
SCATTER OUT TO VFR THIS AFTERNOON.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN WIND TRENDS...MEDIUM CONFIDENCE IN TIMING OF
DIRECTION CHANGES.
* HIGH CONFIDENCE IN MVFR CIGS THROUGH EARLY AFTERNOON...WITH
MEDIUM CONFIDENCE IN HOW LONG THEY CONTINUE THROUGH THE
AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. NORTHEAST WINDS TURNING SOUTHEAST.
SUNDAY...VFR. SOUTH WINDS.
MONDAY...CHANCE OF SHRA/TSRA LATE. MODERATE-STRONG SOUTH WINDS.
TUESDAY...VFR PROBABLE. WEST WINDS.
WEDNESDAY...CHANCE OF RAIN AND IFR/MVFR CIGS. NORTHEAST WINDS.
THURSDAY...CHANCE OF RAIN OR SNOW AND IFR/MVFR. NORTHEAST WINDS.
LENNING
&&
.MARINE...
307 AM CDT
A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THIS MORNING
ACROSS LOWER MICHIGAN AND LAKE HURON. NORTHWEST TO NORTH GALES
WILL EASE QUICKLY THIS MORNING AS THE LOW PULLS AWAY AND THE
PRESSURE GRADIENT WEAKENS. A RIDGE WILL CROSS THE LAKE ON SATURDAY
BEFORE THE NEXT LOW PRESSURE SYSTEM STARTS TO APPROACH OUT OF THE
CENTRAL PLAINS. ALTHOUGH THIS LOW DOES NOT REACH THE LAKE UNTIL
TUESDAY...SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL DEVELOP BY
EARLY SUNDAY. A PERIOD OF GALES IS AGAIN POSSIBLE LATE MONDAY
INTO TUESDAY...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE
LAKE...AS THE LOW MOVES THROUGH.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 2 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
1014 AM CDT Fri Mar 28 2014
.DISCUSSION...
ISSUED 1014 AM CDT Fri Mar 28 2014
Updated forecast to lower highs a few degrees and increase cloud
cover mainly across central/northern CWA. 10 AM visible satellite
imagery showed a strip of clearing north of the Ohio River
extending into the far SE CWA, while farther north a thick blanket
of stratus/SC stretched back through most of MO/IA and southern
WI. HRRR and RAP RH trends in the 950-900 MB level suggest the
clearing over the far SE will slowly shift north towards I-72 by
late afternoon as southerly winds strengthen in that layer. This
clearing will be brief however as mid clouds ahead of next wave
developing in the Plains overspread the region later this
afternoon and evening. Brisk NW winds this morning to ease through
afternoon as low pressure pushes east of the Great Lakes and MSLP
gradient relaxes.
25
&&
.AVIATION...
ISSUED 646 AM CDT Fri Mar 28 2014
MVFR cigs will continue this morning. Big question is how long
will these clouds last. This time of year, clouds at this level
usually burn off rather quickly. However, area is in good cyclonic
flow will lots of clouds/low level moisture across most of MO, all
of Iowa and up into WI. So, think that these clouds will last
longer than normal. So have the MVFR cigs continuing until around
18z, and then lower clouds will scatter out; but high cirrus
around 20kft will have moved in by then. As the next system
approaches the area, but moves south of the state, clouds will
begin to lower during the early evening hours, after 00z, to
around 8kft. Believe rain is possible at DEC and CMI TAFs during
the overnight hours, so have included 5sm -ra with cigs just above
the 3kft foot level. Other sites will not see rain, but see cigs
fall to around 4-5kft late. West winds will remain gusty for a few
hours this morning and then decrease for later this morning, with
CMI being the last one to loose the gusts. As wind speeds
decrease, direction will also become more northerly. Then
northeast winds are expected tomorrow night.
Auten
&&
.PREV DISCUSSION...
ISSUED 313 AM CDT Fri Mar 28 2014
SHORT TERM...Today through Sunday
Main forecast challenge in the immediate short-term will be timing
the departure of low clouds today. 07z/2am surface analysis shows
low pressure over southern Lake Michigan with cold front trailing
southward along the I-57 corridor. Extensive area of wrap-around
cloud cover is noted on IR satellite imagery blanketing Iowa,
northern Missouri, and western Illinois. With low-level flow
becoming northwesterly, these clouds will spill across central
Illinois early this morning. All model guidance suggests an
overcast start to the day, but how quickly the clouds clear out
remains in question. NAM forecast soundings indicate clouds will
mix out/dissipate between 15z and 18z. Latest HRRR hints at this
as well, although the process may be slower than the NAM
advertises. Given subsidence behind departing upper short-wave and
late March sun working on the low clouds, think skies will
temporarily clear around midday into the early afternoon. After
that, high clouds will quickly begin to increase ahead of the next
approaching system by mid to late afternoon.
Next forecast concern revolves around low pressure expected to
track from Texas into the Tennessee River Valley tonight. Models
have been having difficulty resolving how far north associated
precip will spread. 00z Mar 28 suite is still in disagreement,
with the GFS being the most aggressive in bringing precip furthest
north. Since GFS is often too bullish with light QPF events and
airmass will be drying today, think the NAM has a more realistic
handle on the situation. As such, will keep locations along and
north of a Jacksonville to Bloomington line dry tonight. Best rain
chances will be focused along/south of I-70 in closer proximity to
the low track, with POPs steadily decreasing further northwest.
Despite overnight lows in the middle to upper 30s, NAM forecast
soundings remain warm enough for rain. If colder/further north GFS
verifies, a rain/snow mix may be possible along the northern
fringe of the precip area. Will leave mention of mix out of the
forecast due to skepticism about the GFS QPF field.
After a few lingering showers across the far E/SE KILX CWA
Saturday morning, dry and warmer weather will be the rule this
weekend. As southerly winds develop, high temperatures will climb
into the lower to middle 60s by Sunday.
LONG TERM...Monday through Thursday
Models are still advertising cold frontal passage late Monday,
although amount of available moisture appears to be quite limited.
GFS surface dewpoints are initially around 40 degrees Monday
morning and only climb to the upper 40s to near 50 by late
afternoon. Despite decent upper dynamics associated with vigorous
short-wave, lack of deep moisture return from the Gulf will limit
convective potential. As a result, will only carry low chance for
showers on Monday. Slightly cooler and drier weather will settle
into the region behind the departing front on Tuesday before
another system comes into the picture by mid-week. There are still
some key timing differences with this feature: however, all models
agree that it will have much more moisture to work with. With
short-wave crossing the Rockies into the central CONUS, surface
low pressure is expected to track from eastern Colorado on
Tuesday to the southern Great Lakes by Thursday night. Initial
surge of WAA clouds/precip will arrive Tuesday night into
Wednesday: however, with central Illinois remaining in the cool
sector, very little thunder is expected. Once warm front lifts
northward into the area and low pressure approaches from the
southwest, showers and thunderstorms will become more prevalent
Wednesday night into Thursday.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
702 AM CDT FRI MAR 28 2014
.DISCUSSION...
323 AM CDT
TODAY...
SURFACE COLD FRONT IS CLEARING THE EASTERN COUNTIES IN THE CWA EARLY
THIS MORNING WHILE A SECONDARY TROUGH IS DIGGING ACROSS NORTHERN
ILLINOIS WITH WINDS TURNING SHARPLY TO THE NNW WITH GUSTS WELL INTO
THE 20 KT RANGE. SHOWERS BEHIND THIS TROUGH WILL SWEEP ACROSS
NORTHERN ILLINOIS AND NORTHWEST INDIANA...EXITING TO THE EAST BY MID
TO LATE MORNING. BREEZY CONDITIONS THIS MORNING SHOULD GRADUALLY
TAPER THROUGH THE DAY AS THE AS THE LOW LIFTS TOWARDS QUEBEC AND
FILLS. TEMPS INTO THE MID TO UPPER 40S ARE EXPECTED THIS
AFTERNOON...BUT A LAKE BREEZE WILL TURN WINDS NORTHEASTERLY AND COOL
TEMPS BACK INTO THE 30S ALONG THE LAKE.
THIS WEEKEND...
LOW PRESSURE WILL LIFT FROM ARKLATEX INTO THE UPPER OHIO VALLEY BY
MIDDAY SATURDAY. BEST CHANCES FOR PRECIP WILL BE SOUTH OF I-80
ESPECIALLY IN NORTHWEST INDIANA...AND FOR NOW IT APPEARS AREAS NORTH
WILL REMAIN DRY. GFS INDICATES WET BULBS DROPPING BELOW ZERO THROUGH
THE COLUMN AROUND OR BEFORE THE ONSET OF PRECIP INDICATE ALL SNOW.
NAM SOUNDINGS ON THE OTHER HAND SHOW SLIGHTLY WARMER TEMPS ALOFT
HINTING AT THE POSSIBILITY FOR RAIN/SNOW MIX...THOUGH SREF P-TYPE
PROBABILITY INDICATES BETTER CHANCES FOR SNOW. COMING OFF HIGHS IN
THE UPPER 40S IN AREAS MOST LIKELY TO SEE PRECIP...AND OVERNIGHT
LOWS SOUTH OF 80 AT OR EVEN SLIGHTLY ABOVE FREEZING...THE LIKELIHOOD
OF ACCUMULATING SNOW IS LOW AND WOULD LIKELY BE CONFINED TO THE
GRASS. IN ADDITION...GIVEN THE MARGINAL SOUNDINGS...SNOW PRODUCTION
WOULD BE INEFFICIENT. WILL MAINTAIN RAIN/SNOW MIX IN THE FORECAST
FOR NOW GIVEN THE CURRENT UNCERTAINTY.
HIGH PRESSURE WILL THEN TRANSLATE ACROSS THE REGION OVER THE
REMAINDER OF THE WEEKEND RESULTING IN DRY WEATHER FROM SATURDAY
AFTERNOON ON. H85 THERMAL TROUGH WILL APPROACH THE REGION ON
SATURDAY...THOUGH SUBSIDENCE ALOFT SETTLING OVER THE UPPER MIDWEST
THROUGH THE DAY SATURDAY WILL RESULT IN DRYING AND WARMING OF THE
MIDLEVELS WHICH WILL HELP MODULATE THE COLDER AIRMASS MOVING
OVERHEAD. WITH AFTERNOON SUNSHINE...EXPECT AREAS AWAY FROM THE LAKE
TO RISE INTO THE MID TO UPPER 40S AGAIN...WITH A FEW 50S MAINLY
SOUTH OF I-80. ALONG THE LAKE FRONT...A BREEZE OFF THE LAKE THROUGH
THE DAY WILL KEEP TEMPERATURES MUCH COOLER...IN THE MID 30S. THE
SURFACE RIDGE AXIS WILL PASS OVERHEAD SATURDAY NIGHT...AND SOUTHERLY
FLOW WILL RAMP UP THROUGH THE DAY SUNDAY AHEAD OF OUR NEXT AREA OF
LOW PRESSURE STARTING TO TAKE SHAPE OVER THE PLAINS. STRONG WARM
ADVECTION IS EXPECTED THROUGH THE DAY SUNDAY WHICH WILL RESULT IN
H85 TEMPS RISING TO AROUND 10C BY SUNDAY EVENING. SOUTHERLY WINDS
MAY TAKE ON A SLIGHT WESTERLY COMPONENT BY SUNDAY AFTERNOON...IN THE
190-200 DIRECTION...WHICH WITH THE INCREASING WINDS SHOULD HELP
STAVE OFF ANY LAKE BREEZE/LAKE COOLING SUNDAY. NAM/GFS SOUNDINGS
SHOW LOW TO MID 20 KT GUSTS POSSIBLE BY SUNDAY AFTERNOON.
TEMPERATURES SHOULD RISE TO AROUND 60 RIGHT UP TO THE LAKE FRONT
SUNDAY AFTERNOON.
MONDAY...
AFOREMENTIONED SURFACE LOW PROGGED TO LIFT FROM THE MID MISSOURI
VALLEY EARLY MONDAY INTO MN/WI MONDAY EVENING. LATEST GUIDANCE IN
DECENT AGREEMENT ON THE LOCAL AREA GETTING FULL WARM SECTOR ON
MONDAY. LEANED TOWARD WARMER SIDE OF GUIDANCE MONDAY WITH A BLEND OF
BIAS CORRECTED GEM AND ECMWF. THIS RESULTS IN LOW TO MID 60S AREA
WIDE MONDAY AFTERNOON...AND WITH A MODERATE-STRONG SSW WIND...DO NOT
ANTICIPATE ANY COOLING ALONG THE LAKE. A 60-70KT LOW LEVEL JET
FOCUSES STRONG CONVERGENCE ACROSS THE MID MISSOURI VALLEY SUNDAY
NIGHT...THEN AT 40-50 KT REFOCUSES TO OUR NORTH MONDAY
EVENING/NIGHT. ACROSS NORTHERN ILLINOIS IN THE WARM SECTOR...
INSTABILITY IS PRETTY MEAGER WITH A STRONG CAP IN PLACE...THOUGH
SOME DYNAMIC COOLING ASSOCIATED WITH NEGATIVELY TILTED H5 WAVE AND
EXIT REGION OF UPPER JET MAY RESULT IN SOME SCATTERED CONVECTION.
ALL-IN-ALL THOUGH...GIVEN THE UNFAVORABLE TIMING OF THE FRONT
OVERNIGHT...NOT TOO IMPRESSED WITH PRECIP CHANCES MONDAY AND TRIMMED
POPS FOR THIS PERIOD.
TUESDAY THROUGH THURSDAY...
PRETTY LOW CONFIDENCE IN THE DETAILS AT THIS POINT...BUT TUESDAY
THROUGH THURSDAY SHOULD BE AN ACTIVE PERIOD WITH A SERIES OF
DISTURBANCES MOVING ACROSS THE REGION. THERE REMAINS SIGNIFICANT
DIFFERENCES AT THIS POINT BETWEEN MODELS WITH RESPECT TO THE LOW
TRACK WHICH WILL DETERMINE TEMPS AND PRECIP TYPE. GFS INDICATES A
FASTER MORE SOUTHERLY LOW WHILE THE ECMWF HINTS AT A WARMER SOLUTION
WITH A DEEPER LOW THAT TRACKS FARTHER NORTH. FOR NOW...STAYED CLOSE
TO A CONSENSUS BLEND.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* PERIODS OF IFR CIGS WITH RAIN SHOWERS EARLY THIS MORNING...THEN
MVFR INTO AFTERNOON.
* NORTHWEST WINDS GUSTY AT TIMES...TURNING NORTH BY MIDDAY AND NORTHEAST
BY AFTERNOON.
LENNING
//DISCUSSION...UPDATED 12Z...
RAIN SHOWERS WITH POCKETS OF IFR WRAPPING AROUND THE BACK SIDE OF
A DEPARTING LOW WILL CLEAR THE AREA BY MID MORNING. WINDS HAVE
TURNED NORTHWEST AND WILL CONTINUE TO VEER AROUND TO NORTHEAST BY
THE AFTERNOON. NOT CERTAIN ABOUT TIMING OF CHANGE OVER TO AN
EASTERLY COMPONENT BUT BEST ESTIMATE IS AROUND NOON OR SHORTLY
AFTER. LINGERING MVFR CIGS LATE THIS MORNING WILL EVENTUALLY
SCATTER OUT TO VFR THIS AFTERNOON.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE ON TIMING AND DURATION OF IFR EARLY THIS
MORNING...BUT HIGHER CONFIDENCE OF PREVAILING MVFR LATER.
* HIGH CONFIDENCE THAT RAIN SHOWERS WILL END BY MID MORNING.
* MEDIUM CONFIDENCE ON TIMING OF WIND DIRECTION CHANGES.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. NORTHEAST WINDS TURNING SOUTHEAST.
SUNDAY...VFR. SOUTH WINDS.
MONDAY...CHANCE OF SHRA/TSRA LATE. MODERATE-STRONG SOUTH WINDS.
TUESDAY...VFR PROBABLE. WEST WINDS.
WEDNESDAY...CHANCE OF RAIN AND IFR/MVFR CIGS. NORTHEAST WINDS.
THURSDAY...CHANCE OF RAIN OR SNOW AND IFR/MVFR. NORTHEAST WINDS.
LENNING
&&
.MARINE...
307 AM CDT
A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THIS MORNING
ACROSS LOWER MICHIGAN AND LAKE HURON. NORTHWEST TO NORTH GALES
WILL EASE QUICKLY THIS MORNING AS THE LOW PULLS AWAY AND THE
PRESSURE GRADIENT WEAKENS. A RIDGE WILL CROSS THE LAKE ON SATURDAY
BEFORE THE NEXT LOW PRESSURE SYSTEM STARTS TO APPROACH OUT OF THE
CENTRAL PLAINS. ALTHOUGH THIS LOW DOES NOT REACH THE LAKE UNTIL
TUESDAY...SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL DEVELOP BY
EARLY SUNDAY. A PERIOD OF GALES IS AGAIN POSSIBLE LATE MONDAY
INTO TUESDAY...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE
LAKE...AS THE LOW MOVES THROUGH.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 11 AM FRIDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 2 PM FRIDAY.
&&
$$
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WWW.TWITTER.COM/NWSCHICAGO
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Area Forecast Discussion
National Weather Service Lincoln IL
646 AM CDT Fri Mar 28 2014
.DISCUSSION...
ISSUED 313 AM CDT Fri Mar 28 2014
SHORT TERM...Today through Sunday
Main forecast challenge in the immediate short-term will be timing
the departure of low clouds today. 07z/2am surface analysis shows
low pressure over southern Lake Michigan with cold front trailing
southward along the I-57 corridor. Extensive area of wrap-around
cloud cover is noted on IR satellite imagery blanketing Iowa,
northern Missouri, and western Illinois. With low-level flow
becoming northwesterly, these clouds will spill across central
Illinois early this morning. All model guidance suggests an
overcast start to the day, but how quickly the clouds clear out
remains in question. NAM forecast soundings indicate clouds will
mix out/dissipate between 15z and 18z. Latest HRRR hints at this
as well, although the process may be slower than the NAM
advertises. Given subsidence behind departing upper short-wave and
late March sun working on the low clouds, think skies will
temporarily clear around midday into the early afternoon. After
that, high clouds will quickly begin to increase ahead of the next
approaching system by mid to late afternoon.
Next forecast concern revolves around low pressure expected to
track from Texas into the Tennessee River Valley tonight. Models
have been having difficulty resolving how far north associated
precip will spread. 00z Mar 28 suite is still in disagreement,
with the GFS being the most aggressive in bringing precip furthest
north. Since GFS is often too bullish with light QPF events and
airmass will be drying today, think the NAM has a more realistic
handle on the situation. As such, will keep locations along and
north of a Jacksonville to Bloomington line dry tonight. Best rain
chances will be focused along/south of I-70 in closer proximity to
the low track, with POPs steadily decreasing further northwest.
Despite overnight lows in the middle to upper 30s, NAM forecast
soundings remain warm enough for rain. If colder/further north GFS
verifies, a rain/snow mix may be possible along the northern
fringe of the precip area. Will leave mention of mix out of the
forecast due to skepticism about the GFS QPF field.
After a few lingering showers across the far E/SE KILX CWA
Saturday morning, dry and warmer weather will be the rule this
weekend. As southerly winds develop, high temperatures will climb
into the lower to middle 60s by Sunday.
LONG TERM...Monday through Thursday
Models are still advertising cold frontal passage late Monday,
although amount of available moisture appears to be quite limited.
GFS surface dewpoints are initially around 40 degrees Monday
morning and only climb to the upper 40s to near 50 by late
afternoon. Despite decent upper dynamics associated with vigorous
short-wave, lack of deep moisture return from the Gulf will limit
convective potential. As a result, will only carry low chance for
showers on Monday. Slightly cooler and drier weather will settle
into the region behind the departing front on Tuesday before
another system comes into the picture by mid-week. There are still
some key timing differences with this feature: however, all models
agree that it will have much more moisture to work with. With
short-wave crossing the Rockies into the central CONUS, surface
low pressure is expected to track from eastern Colorado on
Tuesday to the southern Great Lakes by Thursday night. Initial
surge of WAA clouds/precip will arrive Tuesday night into
Wednesday: however, with central Illinois remaining in the cool
sector, very little thunder is expected. Once warm front lifts
northward into the area and low pressure approaches from the
southwest, showers and thunderstorms will become more prevalent
Wednesday night into Thursday.
Barnes
&&
.AVIATION...
ISSUED 646 AM CDT Fri Mar 28 2014
MVFR cigs will continue this morning. Big question is how long
will these clouds last. This time of year, clouds at this level
usually burn off rather quickly. However, area is in good cyclonic
flow will lots of clouds/low level moisture across most of MO, all
of Iowa and up into WI. So, think that these clouds will last
longer than normal. So have the MVFR cigs continuing until around
18z, and then lower clouds will scatter out; but high cirrus
around 20kft will have moved in by then. As the next system
approaches the area, but moves south of the state, clouds will
begin to lower during the early evening hours, after 00z, to
around 8kft. Believe rain is possible at DEC and CMI TAFs during
the overnight hours, so have included 5sm -ra with cigs just above
the 3kft foot level. Other sites will not see rain, but see cigs
fall to around 4-5kft late. West winds will remain gusty for a few
hours this morning and then decrease for later this morning, with
CMI being the last one to loose the gusts. As wind speeds
decrease, direction will also become more northerly. Then
northeast winds are expected tomorrow night.
Auten
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1030 AM CDT FRI MAR 28 2014
.UPDATE...
ADJUSTED THE POPS DOWNWARD A LITTLE FOR MOST PLACES FOR THE
REMAINDER OF THE MORNING AND AFTERNOON. LOOKS LIKE CAP SHOULD HOLD
ENOUGH THAT JUST WIDELY SCATTERED SHOWERS...MAINLY LIGHT...UNDER
THE CAP WILL BE ALL THAT CAN GET GOING. AFTER 21Z...4 PM...UPPER
LEVEL SUPPORT WILL BE MOVING TOWARD THE REGION...THIS MAY ALLOW
FOR SOME STRONGER SHOWERS AND STORMS TO DEVELOP OVER WESTERN
PORTIONS OF SOUTHEAST TEXAS...TYLER AND HARDIN COUNTIES...SO HAVE
KEPT HIGHER POPS IN THIS AREA...WITH THE MENTION OF POSSIBLE
SEVERE. ALSO...VISIBILITIES HAVE BEEN IMPROVING OVER THE MARINE
AREAS A LITTLE QUICKER THAN PREVIOUSLY EXPECTED...WITH
VISIBILITIES AT CAMERON UP TO 2 MILES...AND PLATFORMS SOUTHEAST OF
GALVESTON AND SOUTH OF MARSH ISLAND ALSO AROUND 2 MILES. EXPECT A
LITTLE MORE IMPROVEMENT OVER THE NEXT COUPLE OF HOURS AS WARMING
PROVIDES ENOUGH INSTABILITY TO HELP BRIEFLY LIFT THE FOG OR MAKE
IT MORE PATCHY IN NATURE. THEREFORE...WILL HAVE THE MARINE DENSE
FOG ADVISORY EXPIRE AT NOON TIME.
RUA
&&
.PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 28 2014/
AVIATION...LIFR AND IFR CEILINGS WILL CONTINUE THROUGH THE MOST
OF THE MORNING ALONG WITH REDUCED VIS IN BR AND -RA. CONDITIONS
WILL GRADUALLY IMPROVE FROM LATE MORNING INTO THE AFTERNOON,
HOWEVER ADDITIONAL RAIN AND THUNDERSTORMS WILL DEVELOP DURING THE
AFTERNOON AND EVENING. THIS WILL REDUCE CEILINGS AND VIS ONCE
AGAIN. RAIN CHANCES WILL DECREASE PAST MIDNIGHT WITH FG DEVELOPING
TOWARD SAT MORNING. WINDS WILL BE SE TO SW TODAY AT 12 KTS OR LESS
OUTSIDE OF STORMS. WINDS MAY BECOME GUSTY AND ERRATIC IN OR NEAR STORMS.
PREV DISCUSSION... /ISSUED 531 AM CDT FRI MAR 28 2014/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE OVER MAINLY EAST CENTRAL
LOUISIANA THIS MORNING...GENERALLY WITHIN AREA OF ENHANCED LOW
LEVEL MSTR INFLUX/CONVERGENCE AND BENEATH DIVERGENCE ALOFT
ENHANCED BY COUPLED JET STRUCTURE BETWEEN SUB-TROPICAL JET AND JET
MAX ASSOCIATED WITH SHORTWAVE TROF LIFTING THROUGH THE UPPER
MIDWEST. UPSTREAM WATER VAPOR IMAGERY CONTINUES TO DEPICT AN
ACTIVE SUB-TROPICAL JET...WITH ANOTHER SHORTWAVE TROF JUST PASSING
EAST OF THE FOUR CORNERS.
THE ONGOING ACTIVITY IS EXPECTED TO GENERALLY SHIFT EASTWARD THIS
MORNING...WITH A GENERAL LULL IN ACTIVITY EXPECTED UNTIL THE APPROACH
OF THIS UPSTREAM SHORTWAVE LATER THIS AFTERNOON. HRRR AND OTHER
MESOSCALE MODELS INDICATE CONVECTION INITIATING OVER CENTRAL/EAST
TEXAS EARLY TO MID AFTERNOON...WITH SUBSEQUENT DOWNSTREAM
MOVEMENT/DEVELOPMENT ACROSS THE FORECAST AREA THIS EVENING. THE MARINE
LAYER MAY PROVE DETRIMENTAL OVER THE COASTAL COUNTIES/PARISHES...BUT
INSTABILITY IS OVERALL PROGGED TO BE GREATER THAN IT WAS ON
THURSDAY...WITH THE ADDITION OF SFC FEATURES...LIKE THE APPROACHING
CDFNT...TO BETTER FOCUS DEVELOPMENT. SPC HAS ENTIRE AREA OUTLINE
IN A SLIGHT RISK...WITH LARGE HAIL/DAMAGING WINDS THE PRIMARY
HAZARDS. LOW LEVEL SHEAR/HELICITY...WHILE NOT PRECLUDING
TORNADOES...SUGGESTS THE RISK IS SUBORDINATE TO THE OTHER TWO.
DECREASING WINDS HAVE SUBSEQUENTLY RESULTED IN DECREASING VSBYS
OVER THE COASTAL WATERS AS WELL AS INLAND. SUFFICIENT TURBULENT
MIXING WILL LIKELY PREVENT INLAND VSBYS FROM REACHING DENSE FOG
CRITERIA...BUT REFER TO THE MARINE DISCUSSION BELOW FOR THE COASTAL
WATERS.
THE CDFNT IS PROGGED TO SWEEP THROUGH THE REGION LATE TONIGHT...WITH
COOLER AND DRIER AIR GIVING WAY TO A PLEASANT WEEKEND. RAIN
CHANCES LOOK TO RETURN FOR THE MID TO LATTER PART OF THE WEEK AMID
THE RETURN OF A WAA REGIME AND ACTIVE SUB-TROPICAL JET.
13
MARINE...
SOUTH WINDS HAVE STEADILY DECREASED EARLY THIS MORNING...WHICH IS
PERMITTING A SLOWER TRANSPORT OF MOISTURE LADEN AIR OVER
RELATIVELY COOLER SHELF WATERS. THE RESULT HAS BEEN A STEADY
DECREASE IN VISIBILITIES SEEN AT OFFSHORE AND COASTAL REPORTING
SITES. WITH THIS PATTERN EXPECTED TO REMAIN IN PLACE UNTIL A COLD
FRONT PASSES EARLY SATURDAY...CONDITIONS WILL CONTINUE TO SUPPORT
MARINE FOG FORMATION. A MARINE FOG ADVISORY HAS BEEN ISSUED...AND
MAY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7 PM
CDT. GOOD CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED UNTIL
THIS COLD FRONT MOVES THROUGH THE REGION LATE FRIDAY NIGHT INTO
EARLY SATURDAY. A MODEST OFFSHORE FLOW IS EXPECTED OVER THE
WEEKEND IN THE WAKE OF THE FRONT...WITH SOUTHERLY WINDS RETURNING
TO START THE WORK WEEK.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 78 62 76 49 72 / 30 60 10 10 10
KBPT 77 62 78 52 73 / 30 50 10 10 10
KAEX 80 57 72 44 73 / 30 60 10 10 10
KLFT 79 63 74 49 73 / 30 60 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR THE FOLLOWING ZONES:
CALCASIEU LAKE...COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM...COASTAL WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...
SABINE LAKE...VERMILION BAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
638 AM CDT FRI MAR 28 2014
.AVIATION...LIFR AND IFR CEILINGS WILL CONTINUE THROUGH THE MOST
OF THE MORNING ALONG WITH REDUCED VIS IN BR AND -RA. CONDITIONS
WILL GRADUALLY IMPROVE FROM LATE MORNING INTO THE AFTERNOON,
HOWEVER ADDITIONAL RAIN AND THUNDERSTORMS WILL DEVELOP DURING THE
AFTERNOON AND EVENING. THIS WILL REDUCE CEILINGS AND VIS ONCE
AGAIN. RAIN CHANCES WILL DECREASE PAST MIDNIGHT WITH FG DEVELOPING
TOWARD SAT MORNING. WINDS WILL BE SE TO SW TODAY AT 12 KTS OR LESS
OUTSIDE OF STORMS. WINDS MAY BECOME GUSTY AND ERRATIC IN OR NEAR STORMS.
&&
.PREV DISCUSSION... /ISSUED 531 AM CDT FRI MAR 28 2014/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE OVER MAINLY EAST CENTRAL
LOUISIANA THIS MORNING...GENERALLY WITHIN AREA OF ENHANCED LOW
LEVEL MSTR INFLUX/CONVERGENCE AND BENEATH DIVERGENCE ALOFT
ENHANCED BY COUPLED JET STRUCTURE BETWEEN SUB-TROPICAL JET AND JET
MAX ASSOCIATED WITH SHORTWAVE TROF LIFTING THROUGH THE UPPER
MIDWEST. UPSTREAM WATER VAPOR IMAGERY CONTINUES TO DEPICT AN
ACTIVE SUB-TROPICAL JET...WITH ANOTHER SHORTWAVE TROF JUST PASSING
EAST OF THE FOUR CORNERS.
THE ONGOING ACTIVITY IS EXPECTED TO GENERALLY SHIFT EASTWARD THIS
MORNING...WITH A GENERAL LULL IN ACTIVITY EXPECTED UNTIL THE APPROACH
OF THIS UPSTREAM SHORTWAVE LATER THIS AFTERNOON. HRRR AND OTHER
MESOSCALE MODELS INDICATE CONVECTION INITIATING OVER CENTRAL/EAST
TEXAS EARLY TO MID AFTERNOON...WITH SUBSEQUENT DOWNSTREAM
MOVEMENT/DEVELOPMENT ACROSS THE FORECAST AREA THIS EVENING. THE MARINE
LAYER MAY PROVE DETRIMENTAL OVER THE COASTAL COUNTIES/PARISHES...BUT
INSTABILITY IS OVERALL PROGGED TO BE GREATER THAN IT WAS ON
THURSDAY...WITH THE ADDITION OF SFC FEATURES...LIKE THE APPROACHING
CDFNT...TO BETTER FOCUS DEVELOPMENT. SPC HAS ENTIRE AREA OUTLINE
IN A SLIGHT RISK...WITH LARGE HAIL/DAMAGING WINDS THE PRIMARY
HAZARDS. LOW LEVEL SHEAR/HELICITY...WHILE NOT PRECLUDING
TORNADOES...SUGGESTS THE RISK IS SUBORDINATE TO THE OTHER TWO.
DECREASING WINDS HAVE SUBSEQUENTLY RESULTED IN DECREASING VSBYS
OVER THE COASTAL WATERS AS WELL AS INLAND. SUFFICIENT TURBULENT
MIXING WILL LIKELY PREVENT INLAND VSBYS FROM REACHING DENSE FOG
CRITERIA...BUT REFER TO THE MARINE DISCUSSION BELOW FOR THE COASTAL
WATERS.
THE CDFNT IS PROGGED TO SWEEP THROUGH THE REGION LATE TONIGHT...WITH
COOLER AND DRIER AIR GIVING WAY TO A PLEASANT WEEKEND. RAIN
CHANCES LOOK TO RETURN FOR THE MID TO LATTER PART OF THE WEEK AMID
THE RETURN OF A WAA REGIME AND ACTIVE SUB-TROPICAL JET.
13
MARINE...
SOUTH WINDS HAVE STEADILY DECREASED EARLY THIS MORNING...WHICH IS
PERMITTING A SLOWER TRANSPORT OF MOISTURE LADEN AIR OVER
RELATIVELY COOLER SHELF WATERS. THE RESULT HAS BEEN A STEADY
DECREASE IN VISIBILITIES SEEN AT OFFSHORE AND COASTAL REPORTING
SITES. WITH THIS PATTERN EXPECTED TO REMAIN IN PLACE UNTIL A COLD
FRONT PASSES EARLY SATURDAY...CONDITIONS WILL CONTINUE TO SUPPORT
MARINE FOG FORMATION. A MARINE FOG ADVISORY HAS BEEN ISSUED...AND
MAY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7 PM
CDT. GOOD CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED UNTIL
THIS COLD FRONT MOVES THROUGH THE REGION LATE FRIDAY NIGHT INTO
EARLY SATURDAY. A MODEST OFFSHORE FLOW IS EXPECTED OVER THE
WEEKEND IN THE WAKE OF THE FRONT...WITH SOUTHERLY WINDS RETURNING
TO START THE WORK WEEK.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 77 62 76 49 72 / 30 60 10 10 10
KBPT 79 62 78 52 73 / 30 50 10 10 10
KAEX 78 57 72 44 73 / 40 60 10 10 10
KLFT 78 63 74 49 73 / 50 60 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: CALCASIEU LAKE...COASTAL WATERS FROM CAMERON LA TO
HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL
CITY TO CAMERON LA OUT 20 NM...COASTAL WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...
SABINE LAKE...VERMILION BAY.
&&
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&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
531 AM CDT FRI MAR 28 2014
.DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE OVER MAINLY EAST CENTRAL
LOUISIANA THIS MORNING...GENERALLY WITHIN AREA OF ENHANCED LOW
LEVEL MSTR INFLUX/CONVERGENCE AND BENEATH DIVERGENCE ALOFT
ENHANCED BY COUPLED JET STRUCTURE BETWEEN SUB-TROPICAL JET AND JET
MAX ASSOCIATED WITH SHORTWAVE TROF LIFTING THROUGH THE UPPER
MIDWEST. UPSTREAM WATER VAPOR IMAGERY CONTINUES TO DEPICT AN
ACTIVE SUB-TROPICAL JET...WITH ANOTHER SHORTWAVE TROF JUST PASSING
EAST OF THE FOUR CORNERS.
THE ONGOING ACTIVITY IS EXPECTED TO GENERALLY SHIFT EASTWARD THIS
MORNING...WITH A GENERAL LULL IN ACTIVITY EXPECTED UNTIL THE APPROACH
OF THIS UPSTREAM SHORTWAVE LATER THIS AFTERNOON. HRRR AND OTHER
MESOSCALE MODELS INDICATE CONVECTION INITIATING OVER CENTRAL/EAST
TEXAS EARLY TO MID AFTERNOON...WITH SUBSEQUENT DOWNSTREAM
MOVEMENT/DEVELOPMENT ACROSS THE FORECAST AREA THIS EVENING. THE MARINE
LAYER MAY PROVE DETRIMENTAL OVER THE COASTAL COUNTIES/PARISHES...BUT
INSTABILITY IS OVERALL PROGGED TO BE GREATER THAN IT WAS ON
THURSDAY...WITH THE ADDITION OF SFC FEATURES...LIKE THE APPROACHING
CDFNT...TO BETTER FOCUS DEVELOPMENT. SPC HAS ENTIRE AREA OUTLINE
IN A SLIGHT RISK...WITH LARGE HAIL/DAMAGING WINDS THE PRIMARY
HAZARDS. LOW LEVEL SHEAR/HELICITY...WHILE NOT PRECLUDING
TORNADOES...SUGGESTS THE RISK IS SUBORDINATE TO THE OTHER TWO.
DECREASING WINDS HAVE SUBSEQUENTLY RESULTED IN DECREASING VSBYS
OVER THE COASTAL WATERS AS WELL AS INLAND. SUFFICIENT TURBULENT
MIXING WILL LIKELY PREVENT INLAND VSBYS FROM REACHING DENSE FOG
CRITERIA...BUT REFER TO THE MARINE DISCUSSION BELOW FOR THE COASTAL
WATERS.
THE CDFNT IS PROGGED TO SWEEP THROUGH THE REGION LATE TONIGHT...WITH
COOLER AND DRIER AIR GIVING WAY TO A PLEASANT WEEKEND. RAIN
CHANCES LOOK TO RETURN FOR THE MID TO LATTER PART OF THE WEEK AMID
THE RETURN OF A WAA REGIME AND ACTIVE SUB-TROPICAL JET.
13
&&
.MARINE...
SOUTH WINDS HAVE STEADILY DECREASED EARLY THIS MORNING...WHICH IS
PERMITTING A SLOWER TRANSPORT OF MOISTURE LADEN AIR OVER
RELATIVELY COOLER SHELF WATERS. THE RESULT HAS BEEN A STEADY
DECREASE IN VISIBILITIES SEEN AT OFFSHORE AND COASTAL REPORTING
SITES. WITH THIS PATTERN EXPECTED TO REMAIN IN PLACE UNTIL A COLD
FRONT PASSES EARLY SATURDAY...CONDITIONS WILL CONTINUE TO SUPPORT
MARINE FOG FORMATION. A MARINE FOG ADVISORY HAS BEEN ISSUED...AND
MAY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7 PM
CDT. GOOD CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED UNTIL
THIS COLD FRONT MOVES THROUGH THE REGION LATE FRIDAY NIGHT INTO
EARLY SATURDAY. A MODEST OFFSHORE FLOW IS EXPECTED OVER THE
WEEKEND IN THE WAKE OF THE FRONT...WITH SOUTHERLY WINDS RETURNING
TO START THE WORK WEEK.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 77 62 76 49 / 30 60 10 10
KBPT 79 62 78 52 / 30 50 10 10
KAEX 78 57 72 44 / 40 60 10 10
KLFT 78 63 74 49 / 50 60 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CALCASIEU
LAKE-COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT
20 NM-COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA
OUT 20 NM-COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA OUT 20 NM-SABINE LAKE-VERMILION BAY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
633 AM CDT FRI MAR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT FRI MAR 28 2014
THE UPPER LEVEL LOW ACROSS NERN WY APPEARS TO BE DRIFTING EAST
SOUTHEAST WHICH WOULD CARRY IT INTO NRN NEBRASKA THIS AFTERNOON. A
WARM FRONT IS EXPECTED TO LIFT NORTH AHEAD OF THE LOW PUSHING
TEMPERATURES INTO THE UPPER 50S ACROSS SWRN NEB WHILE THE FAR
NORTHEAST REMAINS IN THE UPPER 30S. THE RAP...GEM REGIONAL AND NAM
CONTINUE ISOLATED TO SCATTERED SNOW SHOWERS ALONG THE FRONT WHICH
TRANSITIONS TO RAIN SHOWERS THIS AFTN SOUTH OF THE FRONT. VERY
LITTLE QPF IS EXPECTED...0.05 INCHES OR LESS WITH THIS SYSTEM BUT
THIS COULD BE UNDERDONE GIVEN THE MODELS MAY BE USING RADAR AS A QPF
GUIDE AND THERE IS NO RADAR COVERAGE ACROSS NERN WY.
SO POPS ARE ISOLATED TO SCATTERED AND A WAIT AND SEE APPROACH IS IN
PLACE UNTIL THE SYSTEMS CLEARS THE BLACK HILLS. OBSERVATION SITES IN
NORTHEAST WYOMING HAVE DROPPED BELOW 1 MILE AT TIMES IN THE SNOW SO
THERE MAY AN OPPORTUNITY FOR HIGHER QPF THAN SHOWN BY THESE MODELS.
THE ECM DOES NOT PRODUCE VERY HIGH QPF EITHER.
THIS SYSTEM EXITS THE FCST AREA THIS EVENING AND IN DOING SO TUGS
ANOTHER WEAK AREA OF ARCTIC HIGH PRESSURE INTO THE FCST AREA
OVERNIGHT. LOWS IN THE 20S ARE EXPECTED TONIGHT AND WE SHOULD SEE A
WARM FRONT LIFTING THROUGH WRN NEB AFTER MIDNIGHT SETTING THINGS UP
FOR A WARM DAY ON SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 347 AM CDT FRI MAR 28 2014
A TRANSIENT LOW AMPLITUDE RIDGE WILL BUILD ACROSS THE
CENTRAL/NORTHERN PLAINS THIS WEEKEND...BUT THEN BREAK DOWN LATE
SUNDAY WITH THE APPROACH OF A SOUTH-CENTRAL ROCKIES SHORTWAVE
TROUGH. AT THE SURFACE...A LEE TROUGH OVER THE HIGH PLAINS WILL
DEVELOP SATURDAY IN ADVANCE OF THE APPROACHING UPPER TROUGH. THIS
WILL ALLOW FOR A INCREASING PRESSURE GRADIENT ACROSS CENTRAL
NEBRASKA AS HIGH PRESSURE REMAINS IN THE VICINITY OF THE GREAT
LAKES. TEMPERATURES WILL SOAR IN ADVANCE OF THE LEE SFC TROUGH AS
A DOWNSLOPING SOUTHWESTERLY COMPONENT OF THE LOWER TROPOSPHERIC
WIND COMBINES WITH A FULL LATE MARCH SUN. HIGHS WILL REACH WELL
INTO THE 70S SATURDAY FOR MUCH OF THE SANDHILLS REGION AND POINTS
SOUTH WITH UPPER 60S ELSEWHERE. DEW POINT FORECAST IS PROBLEMATIC
AT THIS POINT...MODEL GUIDANCE HAS STRUGGLE WITH RECENT SIMILAR
EVENTS DISPLAYING A MOIST BIAS OF 20 DEGREES OR MORE AT TIMES
ACROSS THE CENTRAL SANDHILLS AND SOUTHWEST NEBRASKA. ECM DATA AND
THE WRF-ARW SEEM TO HAVE HANDLE THOSE CASES BETTER...KEYING IN ON
THE ADVECTION/MIXING OF ABNORMALLY DRY AIR FROM OUR SOUTHWEST.
THOSE MODELS WERE USED AS A STARTING POINT...AND THEN ADJUSTED
MANUALLY TO ACCOUNT FOR THE INCREASED MIXING/DRYING. IN
ADDITION...THE SHARPENING PRESSURE GRADIENT ELUDED TO ABOVE WILL
WORK IN CONJUNCTION WITH DEEP MIXING GENERATED FROM STEEP LOW
LEVEL LAPSE RATES TO ALLOW FOR GUSTS IN EXCESS OF 25...POSSIBLY 35
MPH...RANGE LATE MORNING THROUGH MUCH OF THE AFTERNOON. GIVEN THE
LARGE TD AND DRY BULB SPREAD...MINIMUM RH OF 15 PERCENT OR LESS IS
LIKELY FOR MUCH OF THE SANDHILLS FIRE ZONES. WILL ISSUE A FIRE
WEATHER WATCH FOR ZONES 204...206...209...210 & 219 WITH THIS
FORECAST PACKAGE WITH THE ANTICIPATION THAT A RFW WILL BE
REQUIRED. SUNDAY IS A BIT LESS APPARENT...INCREASING HIGH LEVEL
CLOUDS WILL SHADE OUR CURED 1HR FUELS AND WINDS ARE FAR LESS
CERTAIN. DESPITE A SIMILAR TD/T SETUP AND FAVORABLE UPPER LEVEL
RIDGE BREAKDOWN PATTERN...WILL HOLD OFF FOR ANOTHER MODEL SUITE
UNTIL ISSUING ANY FIRE HEADLINES FOR SUNDAY. GUIDANCE DISAGREES ON
THE LOCATION OF A SFC TROUGH/WARM FRONT...WITH THE ECM AND GFS OFF
BY GREATER THAN 100 MILES...THERE/S BUST POTENTIAL CONCERNING
MAXIMUM TEMPERATURES ACROSS OUR NORTHERN ZONES ON SUNDAY. AS OF
NOW...GENERALLY SIDED WITH THE ECM CAMP WHICH IS THE WARMER AND
DRIER SOLUTION FOR MUCH OF THE CWA. HIGHS MAY APPROACH 80F SOUTH
OF I80 SUNDAY AFTERNOON...WHERE ALONG THE SOUTH DAKOTA
BORDER...MID 60S IS FORECAST. SOME CONVECTION IS POSSIBLE LATE
SUNDAY AFTERNOON AND EVENING AS THE WAVE TRANSLATES EAST ONTO THE
PLAINS...STEEP LAPSE RATES WILL RESULT IN AT LEAST WEAK ELEVATED
INSTABILITY ACROSS THE ENTIRE CWA...HOWEVER LOWER TROPOSPHERIC
MOISTURE WILL BE LACKING. SFC TD/T SPREADS OF UP TO 40-50F WILL
YIELD HIGH BASED STORMS CAPABLE OF GUSTY OUTFLOW WIND AND POSSIBLY
A FEW CG STRIKES. MODIFIED ARCTIC AIR WILL BE PULLED SOUTH BEHIND
THE WAVE ON MONDAY...WHICH MAY PROVIDE FOR SOME SNOW ACROSS OUR
NORTHERN ZONES...BUT ATTM THE MODELS SEEM TO BE TARGETING THE
NORTHERN PLAINS WITH THE BEST FORCING/HEAVIEST QPF/ACCUMULATIONS.
BEYOND MONDAY...QUASI-ZONAL TO AT TIMES SOUTHWEST FLOW ALOFT WILL
TARGET THE CENTRAL PLAINS THROUGH LATE WEEK. THE MODELS ARE
TRENDING TO ANOTHER TROUGH ENCOMPASSING MUCH OF THE WEST COAST BYE
LATE WEEK. UNSETTLED WEATHER IS PROBABLE IN THIS PATTERN WITH
SEASONAL TO SLIGHTLY BELOW AVERAGE TEMPERATURES LIKELY FOR THE
REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 633 AM CDT FRI MAR 28 2014
AREAS OF MVFR CIGS IN ISOLATED TO SCATTERED SNOW SHOWERS IMPROVE
TO MOSTLY VFR FROM 18Z ONWARD.
ONE AREA OF CONCERN IS ALONG U.S.HIGHWAY 20 WHERE AN ARCTIC FRONT
WILL LIKELY STALL. THE RAP MODEL SUGGESTED MVFR/IFR CIGS NEAR KVTN
THROUGH 02Z THIS EVENING. THE NAM AND GFS INDICATE MVFR IMPROVING
TO VFR AND THIS IS WHAT THE FORECAST USES FOR KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR NEZ204-206-209-210-219.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1058 AM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE
INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM
AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF
SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD
FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER
OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY.
TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD
FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...HIGH PRESSURE IS WELL OFFSHORE AND SOUTH
WINDS ACROSS THE CAROLINAS ARE BEING CAUSED BY RETURN FLOW BETWEEN
THE HIGH AND A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS.
SUBTROPICAL MOISTURE MOVING NORTHWARD IS SHOWING UP WITH CLIMBING
SURFACE DEWPOINTS AND PRECIPITABLE WATER VALUES...BOTH EXPECTED TO
RISE SIGNIFICANTLY TONIGHT.
AN AREA OF THICK MID AND HIGH CLOUDINESS ACROSS THE SOUTHEASTERN
STATES IS BEING PRODUCED BY A MESOSCALE CONVECTIVE SYSTEM ACROSS
MISSISSIPPI. SYNOPTIC MODELS ARE HAVING THEIR TROUBLE WITH THIS
SYSTEM...BUT THE LATEST FEW RUNS OF THE HRRR SHOW THE BULK OF THIS
CONVECTION DIMINISHING BEFORE ADVECTING THIS FAR EAST. INCREASING
MOISTURE SHOULD YIELD AN INCREASE IN SHOWER ACTIVITY LATE THIS
AFTERNOON ACROSS THE PEE DEE REGION...REACHING THE COAST AROUND
SUNSET OR SHORTLY THEREAFTER. A SECOND UNRELATED AREA OF SHOWERS
DEVELOPING ALONG THE GULF STREAM OFF THE GA/SC COAST IS STREAMING
NORTHWARD NEAR CHARLESTON AND GEORGETOWN...AND THREATENS TO BRING
SHOWERS ACROSS EASTERN SOUTH CAROLINA OVER THE NEXT SEVERAL HOURS.
POP/WX FORECASTS HAVE BEEN UPDATED TO FOCUS ON THESE TWO AREAS.
FEW CHANGES HAVE BEEN MADE TO FORECAST TEMPERATURES...STILL EXPECTED
TO REACH THE LOWER 70S FOR MOST AREAS AWAY FROM THE COOLING
INFLUENCE OF THE OCEAN.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SURFACE LOW AND MID LEVEL TROUGH WILL BE WEST
OF THE AREA AT THE START OF THE PERIOD WITH THE REGION SOLIDLY IN
THE WARM SECTOR. SEVERAL FACTORS APPEAR TO BE IN PLACE SUPPORTING
CONVECTION SAT INTO SAT NIGHT. STRENGTHENING MID LEVEL SOUTHWEST
FLOW WILL CONTINUE TO PUMP MOISTURE INTO THE REGION. FORECAST
SOUNDINGS SHOW PRECIPITABLE WATER VALUES CLOSE TO 1.5 INCH. DIURNAL
INSTABILITY WILL ALSO BE PRESENT WITH HIGHS EXPECTED TO CLIMB INTO
THE LOWER 70S IN MOST AREAS. LOW LEVEL CONVERGENCE ALONG THE
RESULTANT SEA BREEZE MAY INITIATE CONVECTION IN THE AFTERNOON. ALOFT
THE APPROACHING 5H TROUGH WILL ENHANCE MID LEVEL LAPSE RATES BUT THE
UNKNOWN FACTOR AT THIS POINT REMAINS WHAT IMPACT POTENTIAL
CONVECTION IN THE NORTHEAST GULF OF MEXICO WILL HAVE ON INSTABILITY
SHOWERS/THUNDERSTORMS.
FARTHER WEST A LINE OF CONVECTION SHOULD BE DEVELOPING ASSOCIATED
WITH THE ADVANCING COLD FRONT. THIS LINE WILL MOVE INTO WHAT SHOULD
BE A MOIST/UNSTABLE ENVIRONMENT LATE SAT AND PUSH OFF THE COAST SAT
NIGHT. ALTHOUGH THE FRONT WILL HAVE PLENTY OF LOW LEVEL CONVERGENCE
AND MID LEVEL SUPPORT THERE IS SOME QUESTION AS TO THE STATE OF THE
ATMOSPHERE IT WILL BE MOVING INTO. THE CONVECTIVE LINE ASSOCIATED
WITH THE FRONT MAY END UP WEAKENING AS IT MOVES INTO THE REGION IF
EARLIER AFTERNOON CONVECTION IS MORE WIDESPREAD AND USES UP A LOT OF
THE AVAILABLE INSTABILITY. ON THE OTHER HAND SHOULD THE GULF
CONVECTION BE ABLE TO SUPPRESS MUCH OF THE ACTIVITY DURING THE FIRST
HALF OF SAT THE COLD FRONT WOULD HAVE PLENTY OF INSTABILITY TO WORK
WITH. SO IT IS NOT SO MUCH A QUESTION OF WILL IT RAIN...BUT MORE OF
A QUESTION OF WHEN WILL IT RAIN.
SEVERE WEATHER THREAT PERSISTS...ALTHOUGH WITH CAVEATS. LOW LEVEL
JETTING WILL BE WEAK FOR MUCH OF THE DAY BEFORE INCREASING TO 30 TO
35 KT JUST AHEAD OF THE FRONT. THE MAIN THREAT WOULD BE DAMAGING
WIND...ENHANCED BY STORMS MOVING CLOSE TO 30 MPH. IF STRONG/SEVERE
STORMS DEVELOP THEY ARE LIKELY TO DO SO WITH THE LINE OF CONVECTION
AHEAD OF THE FRONT...AGAIN ASSUMING DIURNAL DRIVEN CONVECTION IS
LIMITED IN SCOPE DURING THE DAY SAT.
COLD FRONT PUSHES OFF THE COAST LATE SAT NIGHT WITH THE MID LEVEL
TROUGH FOLLOWING ON SUN. COLD ADVECTION BEHIND THE FRONT WILL DROP
SUN TEMPS BELOW CLIMO...BUT COLD AIR WILL BE A LITTLE TOO LATE TO
HAVE A SIGNIFICANT IMPACT ON SAT NIGHT LOWS WHICH WILL END UP NEAR
TO SLIGHTLY ABOVE CLIMO. SUN SHOULD BE DRY WITH DEEP NORTHWEST FLOW
BEHIND THE TROUGH DROPPING PWATS UNDER .5 INCH FOR SUN AM AND UNDER
.25 INCH BY SUN EVENING. GRADIENT RELAXES SUN NIGHT BUT HIGH REMAINS
WEST OF THE AREA THROUGH THE END OF THE PERIOD SO SUN NIGHT WILL NOT
BE AN IDEAL RADIATIONAL COOLING NIGHT. STILL LOWS END UP BELOW CLIMO.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...LOW AMPLITUDE MID LEVEL RIDGING AND SPRAWLING
SURFACE HIGH WILL KEEP THE AREA DRY AND SEASONABLE THROUGH THE
PERIOD. COOLEST DAY WILL BE MON WITH SURFACE HIGH DIRECTLY OVERHEAD.
HIGH THEN DRIFTS OFFSHORE TUE THROUGH THU BRINGING SEVERAL DAYS OF
BEAUTIFUL SPRING WEATHER. PREVIOUSLY MEDIUM RANGE GUIDANCE HAD BEEN
MOVING A DRY COLD FRONT ACROSS THE AREA TUE NIGHT INTO WED. NOW THAT
GUIDANCE IS SUGGESTING MORE MID LEVEL AMPLIFICATION THIS SEEMS
UNLIKELY AND IN FACT THE 00Z GUIDANCE IS BACKING OFF ON THE DRY
FRONT. TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO MON TRANSITION TO
ABOVE CLIMO MON NIGHT THROUGH THE END OF THE PERIOD.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...RETURN FLOW WILL COMMENCE SHORTLY. HAVE LEANED FAIRLY
HEAVILY ON THE HRRR EARLY...WITH SHOWERS POPPING UP ALONG THE
MYRTLES BY LATE MORNING. INCREASING SOUTHERLY GRADIENT WILL CAUSE
WINDS TO GUSTS OVER 20 KTS AT TIMES...ESPECIALLY ALONG THE COAST.
SCATTERED SHOWERS WILL GIVE WAY TO MORE WIDESPREAD RAIN THIS EVENING
AS DEEP MOISTURE MOVES INTO THE REGION. RAIN CHANCES WILL BE HIGHEST
INLAND THIS EVENING...SPREADING TO THE COAST A FEW HOURS LATER.
CEILINGS ARE A BIT PROBLEMATIC...BUT WILL GO FOR MVFR PREDOMINATELY
WITH POCKETS OF IFR POSSIBLE.
EXTENDED OUTLOOK...SHOWERS AND T-STORMS WITH MVFR/TEMPO IFR
CONDITIONS OVERNIGHT AND ON SATURDAY. VFR SUNDAY THROUGH TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...HIGH PRESSURE THAT MOVED OFF THE NC COAST
YESTERDAY IS NOW CROSSING 60 DEGREES WEST LONGITUDE AS IT CONTINUES
TO PUT DISTANCE BETWEEN ITSELF AND THE EAST COAST. LOW PRESSURE
MOVING THROUGH THE GREAT LAKES HAS A COLD FRONT EXTENDING SOUTH INTO
TEXAS. THIS FRONT WILL NOT ARRIVE UNTIL TOMORROW...ALLOWING
SOUTHERLY WINDS AHEAD OF THE FRONT TO CONTINUE ADVECTING A
SUBTROPICAL AIRMASS ACROSS THE COASTAL WATERS. AS DEWPOINTS INCREASE
AND EXCEED THE NEARSHORE WATER TEMPERATURES THERE IS AN INCREASING
POTENTIAL FOR SEA FOG THIS AFTERNOON AND TONIGHT...PARTICULARLY
WITHIN 10 MILES OF SHORE WHERE WATER TEMPERATURES ARE COLDEST.
SOUTH WINDS CURRENTLY AROUND 10-12 KNOTS SHOULD INCREASE A FEW MORE
KNOTS TODAY...BUT MAY ACTUALLY DIMINISH A LITTLE THIS EVENING AS AN
AREA OF DYING CONVECTION ARRIVES AND THE PRESSURE GRADIENT IS
DISRUPTED. REGARDLESS...WINDS SHOULD BUILD BACK UP TOWARD 12-15
KNOTS OVERNIGHT. SEAS ARE STILL A BIT HIGHER THAN WIND SPEEDS ALONE
WOULD SUGGEST...COURTESY OF THE HUGE LOW THAT MOVED NORTH THROUGH
THE WESTERN ATLANTIC A FEW DAYS AGO. AT THE FRYING PAN SHOALS BUOY
THERE IS STILL A SMALL 14 SECOND EAST SWELL PRESENT...WHICH WHEN
ADDED TO THE SHORTER 6-SECOND PERIOD WIND WAVES TOTALS AROUND 4
FEET. TOTAL SEAS EVEN INSIDE 20 MILES SHOULD INCREASE ON TOWARD 4-6
FEET BY THIS EVENING.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SOUTHERLY FLOW WILL APPROACH 20 KT SAT AS
GRADIENT OVER THE WATERS IS PINCHED BETWEEN ADVANCING COLD FRONT AND
HIGH PRESSURE. ANTICIPATE A LINE OF CONVECTION AHEAD OF THE FRONT
WHICH WILL CROSS THE WATERS SAT EVE/NIGHT. OFFSHORE FLOW DEVELOPS
BEHIND THE FRONT WITH GRADIENT AND DEVELOPING COLD ADVECTION KEEPING
SPEEDS AROUND 20 KT. LITTLE CHANGE IN THE GRADIENT SUN AS HIGH
BUILDS KEEPS NORTHWEST WINDS A SOLID 20 KT FOR MUCH OF THE DAY.
OFFSHORE FLOW SLOWLY WEAKENS SUN NIGHT...DROPPING TO 15 KT BY THE
END OF THE PERIOD...AS GRADIENT RELAXES. SEAS 4 TO 6 FT EXPECTED SAT
INTO SUN WHEN OFFSHORE COMPONENT DROPS SEAS TO 3 TO 5 FT. CONTINUED
OFFSHORE FLOW COMBINED WITH REDUCTION IN SPEEDS SUN NIGHT WILL DROP
SEAS TO 2 TO 4 FT BY THE END OF THE PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...OFFSHORE FLOW AROUND 15 KT AT THE START OF THE
PERIOD WILL DECREASE DURING MON AS HIGH PRESSURE MOVES OVER HEAD.
SPEEDS WILL DROP UNDER 10 KT BY MON EVENING...BECOMING LIGHT AND
VARIABLE MON NIGHT. HIGH SHIFTS OFFSHORE FOR TUE WITH RETURN FLOW
SLOWLY RISING INTO THE 10 TO 15 KT RANGE LATE TUE AND TUE NIGHT.
SEAS WILL RUN 2 TO 3 FT FOR A MAJORITY OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT
SATURDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...SGL/RJD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
953 AM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATER TODAY AND THEN
STALL TO THE NORTH TONIGHT. DEVELOPING LOW PRESSURE MOVING ACROSS TO
THE NORTH WILL PULL THE FRONT THROUGH THE AREA SATURDAY NIGHT. THE
LOW WILL CONTINUE DEEPENING AS IT MOVES TO THE NORTHEAST SUNDAY AND
SUNDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE WEST THROUGH
MONDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 945 AM FRIDAY...TEMPERATURES HAVE WARMED VERY QUICKLY THIS
MORNING WITH MOST AREAS ALREADY WELL INTO THE 60S. AS A
RESULT...HAVE RAISED MAXIMUM TEMPERATURES A COUPLE OF
DEGREES...ESPECIALLY ALONG THE SOUTH COAST. CLOUDS WILL CONTINUE
TO INCREASE DURING THE AFTERNOON...BUT RAP AND 4KM WRF MODELS HOLD
OFF ANY PRECIPITATION UNTIL AFTER 21Z OVER THE WESTERN COASTAL
PLAINS COUNTIES. EXPECT A BROKEN LINE OF SHOWERS...BUT INSTABILITY
WILL BE MARGINAL FOR ANY THUNDER LATE THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS OF 430 AM FRIDAY...INCREASING MSTR AND SHRT WV ACTIVITY WILL
PRODUCE HIGHER THREAT OF SHOWERS TONIGHT...WITH TSTM MENTION LIMITED
TO COAST. GENERALLY CONTINUED PREVIOUS FCST OF POPS 50% COAST TO 70%
INLAND THIS EVENING...AND 60%-70% ALL ZONES OVERNIGHT. SRLY FLOW AND
CLOUD COVER WILL KEEP TEMPS MID 50S TO AROUND 60.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 4 AM FRI...UNSETTLED PATTERN TO START THE LONG TERM PERIOD
THIS WEEKEND...THEN DRY AND SEASONABLY WARM FOR NEXT WEEK.
SHORT WAVE TROUGH ACROSS CENTRAL CONUS TODAY WILL AMPLIFY THROUGH
SATURDAY AND CLOSE OFF A MID LEVEL VORT SAT EVENING. MODELS COMING
IN BETTER AGREEMENT ON THIS SYNOPTIC SETUP AS WELL AS TIMING OF
THE FEATURES. THE NEUTRAL TILT CLOSED LOW WILL PROMOTE SFC LOW
DEVELOPMENT OVER CENTRAL NC SAT EVENING. AHEAD OF IT...INC SW LLJ
WILL FURTHER INC MOISTURE ADVECTION INTO E NC. BNDRY LAYER
STREAMLINES SUGGEST MOISTURE CONVERGENCE WILL BE MAXIMIZED SAT
EVENING...WITH BEST CHANCE OF WIDESPREAD RAIN SHOWERS OCCURRING
THEN. AHEAD OF THE SYSTEM...OCNL SHOWERS WITH EMBEDDED THUNDER
WILL OCCUR DURING THE DAY SAT. GFS ENSEMBLES CLUSTER FAIRLY WELL
WITH SFC LOW PLACEMENT ACROSS NC TO SOUTHERN VA BETWEEN 00Z AND
06Z SUN. THE 28/00Z ECM IS ALSO FAVORING THIS GENERAL POSITIONING
OF THE LOW. AS FAR AS SVR POTENTIAL IS CONCERNED...WIDESPREAD
CLOUDINESS AND RAIN SHOWER ACTIVITY WILL ACT TO LIMIT
DESTABILIZATION DURING THE DAY SAT...AND NOT EXPECTING MUCH IN WAY
OF ORGANIZED CONVECTION. NEVERTHELESS...BULK SHEAR WILL BE
SUFFICIENT FOR A FEW STORMS TO BECOME STRONG TO SEVERE WITH MAIN
THREAT ISOLATED DAMAGING WINDS. GFS AND NAM INDICATE SFC WINDS
BECOME BACKED SSE SAT EVENING AS H85-H90 FLOW REMAINS SW. THIS
WOULD PRODUCE FAIR AMOUNT OF LOW LEVEL TURNING/0-3KM HELICITY.
SHOULD ANY STORMS BECOME MORE ORGANIZED...CANNOT RULE OUT AN
ISOLATED TORNADO THREAT ESP LATE SAT AFTERNOON THROUGH EARLY
EVENING BEFORE LOW PULLS EAST AND SFC WINDS VEER SW TO W.
RAIN SHOWERS WILL DECREASE SAT NIGHT AS MOISTURE AND LIFT SHIFT
EAST WITH SFC EXITING SFC LOW. TEMPS WILL BE MILD MOST OF THE
NIGHT BEFORE WINDS BECOME W TO EVENTUALLY NW BY LATE SAT NIGHT AND
ALLOW TEMPS TO COOL TO THE LOW 50S. UPR LEVEL VORT WILL SLOWLY
MIGRATE EAST THROUGH THE DAY SUNDAY...AND HAVE CONTINUED TO WEIGHT
ECMWF SOLN WHICH WOULD KEEP WIDESPREAD LOW CLOUDS AND NUMEROUS
SHOWERS ACROSS E NC THROUGH THE FIRST HALF OF SUNDAY. HAVE INC
POPS TO LIKELY ACROSS THE NE ZONES...AND RETAINED HIGH CHANCE SCT
WORDING FURTHER S AND W. TEMPS WILL ALSO BE ON THE COOL SIDE WITH
THE WIDESPREAD CLOUDS AND SHOWER ACTIVITY WITH MOST AREAS IN THE
MID 50S...WITH SOME LOW 50S OBX.
DRAMATIC CLEARING OCCURS SUN NIGHT AS UPR LOW MOVES OUT TO SEA AND
TEMPS SEASONABLY COOL IN THE UPR 30S/LOW 40S FOR LOWS MON MORNING.
VERY DRY AIRMASS FOR MONDAY AS STRONG SUBSIDENCE AND BUILDING HIGH
PRES MOVE INTO THE AREA. 1000-850MB RH VALS PLUMMET TO THE 20%
RANGE ACCORDING TO THE ECM. WILL HAVE TO MONITOR FOR POTENTIAL
FIRE WEATHER CONCERNS. TEMPS WILL REBOUND TO THE MID/UPR 60S.
SPRAWLING SFC HIGH PRES WITH QUASI ZONAL FLOW WILL PRODUCE
PLEASANTLY DRY AND WARM CONDITIONS THROUGH THE MID WEEK TIME
PERIOD AND BEYOND WITH TEMPS WARMING TO THE MID/UPR 70S TO NEAR 80
BY THURSDAY. NEXT SYSTEM MAY AFFECT THE REGION FRIDAY INTO THE
WEEKEND.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 12Z SATURDAY/...
AS OF 730 AM FRIDAY...VFR CONDITIONS WILL PREVAIL INTO THIS
AFTN...THEN MVFR CIGS/VSBYS EXPECTED WITH SHRA DURING EVENING
LINGERING INTO OVERNIGHT. PRE-FRONTAL WARM SECTOR CONDITIONS
EXPECTED DURING THE TAF PERIOD WITH HIGH PRES OFFSHORE AND COLD
FRONT APPROACHING FROM W. SCT-BKN SCU WILL DEVELOP THROUGH MORNING
HOURS WITH INCREASING SRLY FLOW BUT CIGS EXPECTED TO REMAIN ABOVE 3K
FT. ISOLD SHRA PSBL INLAND LATE MORNING BUT BETTER COVERAGE LIKELY
DURING AFTN AND EVENING WITH CIGS AND VSBYS LOWERING TO MVFR. MOIST
LOW LVLS WILL RESULT IN CIGS LOWERING TO AROUND 1K FT FOR INLAND
SITES OVERNIGHT. SRLY WINDS WILL GUST UP TO 20-25 KT THIS AFTN.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 4 AM FRI...MVFR OR LOWER IN NUMEROUS SHOWERS AND EMBEDDED
THUNDER SAT THROUGH SAT NIGHT. THE FRONT WILL MOVE OFF THE COAST
EARLY SUNDAY WITH SURFACE WINDS VEERING FROM SOUTH SOUTHWEST TO
NORTHWEST. SUB-VFR CONTINUES SUNDAY WITH SCATTERED TO NUMEROUS
SHOWERS IN LINGERING WRAPAROUND MOISTURE. VFR RETURNS ON SUN NIGHT
THROUGH MUCH OF NEXT WEEK AS LARGE HIGH PRES BUILDS IN BRINGING
EXCELLENT FLYING CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 955 AM FRIDAY...TIGHTENING PRES GRAD EXPECTED TO PRODUCE
15-20 KT WINDS OVER NEAR SHORE WATERS DURING THE AFTERNOON...WITH SEAS
BUILDING TO 4-6 FT SRN WATERS...THUS CONTINUED SCA. WINDS WILL
DIMINISH THIS EVENING AS GRADIENT WEAKENS...AND SEAS FALLING BELOW
6 FT AGAIN LATE TONIGHT.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 4 AM FRI...POOR BOATING CONDITIONS SAT THROUGH THE FIRST PART
OF NEXT WEEK. SW WINDS WILL INC ONCE AGAIN DURING THE DAY SAT TO 25
KT OR HIGHER...ESP THE SOUTHERN/CENTRAL WATERS...AND SEAS WILL INC
TO 6 FT OR HIGHER. THE S TO SW WINDS WILL REMAIN STRONG THROUGH SAT
EVENING AHEAD OF LOW PRES AND A COLD FRONT. THE LOW WILL MOVE
OFFSHORE WITH THE COLD FRONT LATE SAT NIGHT AND WINDS TURNING TO THE
W AND THEN NW BY SUN MORNING. THE OFFSHORE LOW WILL SLOWLY PUSH AWAY
AND KEEP THE NW GRADIENT RATHER STRONG WITH SCA CONTINUING THROUGH
THE DAY SUNDAY. WINDS WILL FINALLY DIMINISH ON MONDAY THOUGH
LINGERING LARGE SWELL ABOVE 6 FT WILL CONTINUE ESP ACROSS
NORTHERN/CENTRAL WATERS. CONDITIONS IMPROVE MON NIGHT AS GRADIENT
RELAXES. WINDS WILL TURN SW BUT REMAIN LIGHT TUE THROUGH MID WEEK AS
LARGE HIGH PRES MOVES TO THE SOUTH OF THE AREA. PLEASANT BOATING
CONDITIONS EXPECTED DURING THIS TIME FRAME.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...TL
AVIATION...JBM/TL
MARINE...JBM/CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
654 AM EDT FRI MAR 28 2014
.SYNOPSIS...
MUCH MORE MOIST AND WARMER AIR WILL BE IN PLACE AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST. THE FRONT WILL MOVE ACROSS THE AREA
SATURDAY NIGHT. THE RISK FOR SHOWERS AND THUNDERSTORMS WILL BE ON
THE INCREASE UNTIL PASSAGE OF THE COLD FRONT. SOME STORMS MAY BE
STRONG TO SEVERE SATURDAY AND SATURDAY NIGHT. A BRIEF COOL DOWN WILL
OCCUR BEHIND THE FRONT SUNDAY. HIGH PRESSURE NEXT WEEK WILL BRING
DRY WEATHER WITH TEMPERATURES CLIMBING WELL ABOVE NORMAL. A COLD
FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM FRIDAY...RETURN FLOW AROUND DEPARTING HIGH PRESSURE HAS
TAKEN A FIRM HOLD ON THE AREA AND WE ARE BEGINNING TO SEE DEWPOINTS
SURGE HIGHER...NOW UP TO THE MID AND UPPER 40S ALONG THE COAST...AND
IN THE LOWER 40S FOR MOST INLAND LOCATIONS. TEMPS HAVE ALSO RISEN
WITH THE APPROACH OF MORNING...IN THE MID AND UPPER 40S IN MOST
LOCATIONS...TOPPING 50 DEGREES IN SOME COASTAL AREAS.
DEEP S TO SW FLOW WILL BE IN PLACE THIS PERIOD AND THIS WILL BRING
INCREASING MOISTURE AND TEMPERATURE WHICH WILL RESULT IN INCREASED
INSTABILITY. PRECIPITABLE WATER VALUES WILL BE NEAR 1 INCH THIS
MORNING...CLIMBING TO 1.25 TO 1.5 INCHES LATER TODAY AND TONIGHT.
THE COLUMN SUFFICIENTLY SATURATES TO A DEPTH THAT DOES SUPPORT
MEASURABLE PRECIPITATION. SHORTWAVE ENERGY IN THE MID LEVELS DOES
APPROACH FROM THE W TODAY AND THEN ACROSS THE AREA TONIGHT. THERE IS
SOME INDICATION THE ENERGY MAY SPLIT...WITH THE FORECAST AREA LYING
IN BETWEEN THE BEST UPPER LEVEL SUPPORT. THERE IS ALSO SOME CONCERN
THAT WIDESPREAD CONVECTION ALONG THE GULF COAST MAY SERVE TO ROB OR
AT LEAST DELAY DEEPER MOISTURE RETURN.
AN EXAMINATION OF INSTABILITY AND MID LEVEL LAPSE RATES DOES SUPPORT
INCLUSION OF HIGHER POPS THIS PERIOD. MIXED LAYER CAPE VALUES DO
CLIMB TO 300 J/KG WHILE SURFACE BASED VALUES REACH 500 TO 1000 J/KG.
MID LEVEL LAPSE RATES DO REACH UP TO 7 DEG C/KM.
SO ALTHOUGH WE ARE CONFIDENT MEASURABLE PRECIPITATION WILL OCCUR...
THERE IS SOME UNCERTAINTY AS TO WHEN TO INCLUDE THE HIGHEST POPS.
LOOKING AT THE MOST RECENT RADAR/SATELLITE DATA...THERE IS A LARGE
AREA OF DEEP CONVECTION ONGOING ACROSS THE CENTRAL AND EASTERN GULF
COASTAL AREAS. THIS SUGGESTS DEEPEST MOISTURE RETURN MAY BE DELAYED.
EXTRAPOLATION FOR TIMING WOULD BRING THE HIGHEST RISK FOR SHOWERS
AND THUNDERSTORMS INTO THE AREA TONIGHT...MORE LIKELY LATE TONIGHT
WITH THE ARRIVAL OF AN UPPER LEVEL IMPULSE WORKING ITS WAY UP THE
CAROLINA COAST. OF COURSE THIS DOES NOT PRECLUDE SHOWERS AND SOME
THUNDERSTORMS TODAY OR THIS EVE AND HIGHER RESOLUTION MODELS ARE
SHOWING CONVECTION BREAKING OUT WITH HEATING OF THE DAY WITH PERHAPS
THE SEA BREEZE SERVING AS A FOCAL POINT. RAINFALL AMOUNTS WILL BE
HIGHLY VARIABLE...BUT SOME LOCATIONS COULD RECEIVE AS MUCH AS
THREE-QUARTERS OF AN INCH WITH ONE-QUARTER TO ONE-HALF INCH MORE
COMMON...THESE AMOUNTS JUST THROUGH TONIGHT.
THICKER CLOUD COVER WILL BE ARRIVING/DEVELOPING THROUGH THE DAY WITH
MORE OR LESS CLOUDY SKIES EXPECTED DURING THE AFTERNOON AND TONIGHT.
ALSO...AS DEWPOINTS CREEP HIGHER...WE SHOULD BEGIN TO SEE SEA
STRATUS/SEA FOG DEVELOP...PERHAPS IMPINGING ONTO THE IMMEDIATE COAST
IN SOUTHERLY FLOW LATE DAY AND ESPECIALLY TONIGHT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 70S TODAY...BUT THE SEABREEZE
WILL KEEP COASTAL AREAS IN THE MID AND UPPER 60S. LOWS TONIGHT WILL
BE BALMY AS COMPARED TO RECENT NIGHTS...UPPER 50S TO AROUND 60
DEGREES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SURFACE LOW AND MID LEVEL TROUGH WILL BE WEST
OF THE AREA AT THE START OF THE PERIOD WITH THE REGION SOLIDLY IN
THE WARM SECTOR. SEVERAL FACTORS APPEAR TO BE IN PLACE SUPPORTING
CONVECTION SAT INTO SAT NIGHT. STRENGTHENING MID LEVEL SOUTHWEST
FLOW WILL CONTINUE TO PUMP MOISTURE INTO THE REGION. FORECAST
SOUNDINGS SHOW PRECIPITABLE WATER VALUES CLOSE TO 1.5 INCH. DIURNAL
INSTABILITY WILL ALSO BE PRESENT WITH HIGHS EXPECTED TO CLIMB INTO
THE LOWER 70S IN MOST AREAS. LOW LEVEL CONVERGENCE ALONG THE
RESULTANT SEA BREEZE MAY INITIATE CONVECTION IN THE AFTERNOON. ALOFT
THE APPROACHING 5H TROUGH WILL ENHANCE MID LEVEL LAPSE RATES BUT THE
UNKNOWN FACTOR AT THIS POINT REMAINS WHAT IMPACT POTENTIAL
CONVECTION IN THE NORTHEAST GULF OF MEXICO WILL HAVE ON INSTABILITY
SHOWERS/THUNDERSTORMS.
FARTHER WEST A LINE OF CONVECTION SHOULD BE DEVELOPING ASSOCIATED
WITH THE ADVANCING COLD FRONT. THIS LINE WILL MOVE INTO WHAT SHOULD
BE A MOIST/UNSTABLE ENVIRONMENT LATE SAT AND PUSH OFF THE COAST SAT
NIGHT. ALTHOUGH THE FRONT WILL HAVE PLENTY OF LOW LEVEL CONVERGENCE
AND MID LEVEL SUPPORT THERE IS SOME QUESTION AS TO THE STATE OF THE
ATMOSPHERE IT WILL BE MOVING INTO. THE CONVECTIVE LINE ASSOCIATED
WITH THE FRONT MAY END UP WEAKENING AS IT MOVES INTO THE REGION IF
EARLIER AFTERNOON CONVECTION IS MORE WIDESPREAD AND USES UP A LOT OF
THE AVAILABLE INSTABILITY. ON THE OTHER HAND SHOULD THE GULF
CONVECTION BE ABLE TO SUPPRESS MUCH OF THE ACTIVITY DURING THE FIRST
HALF OF SAT THE COLD FRONT WOULD HAVE PLENTY OF INSTABILITY TO WORK
WITH. SO IT IS NOT SO MUCH A QUESTION OF WILL IT RAIN...BUT MORE OF
A QUESTION OF WHEN WILL IT RAIN.
SEVERE WEATHER THREAT PERSISTS...ALTHOUGH WITH CAVEATS. LOW LEVEL
JETTING WILL BE WEAK FOR MUCH OF THE DAY BEFORE INCREASING TO 30 TO
35 KT JUST AHEAD OF THE FRONT. THE MAIN THREAT WOULD BE DAMAGING
WIND...ENHANCED BY STORMS MOVING CLOSE TO 30 MPH. IF STRONG/SEVERE
STORMS DEVELOP THEY ARE LIKELY TO DO SO WITH THE LINE OF CONVECTION
AHEAD OF THE FRONT...AGAIN ASSUMING DIURNAL DRIVEN CONVECTION IS
LIMITED IN SCOPE DURING THE DAY SAT.
COLD FRONT PUSHES OFF THE COAST LATE SAT NIGHT WITH THE MID LEVEL
TROUGH FOLLOWING ON SUN. COLD ADVECTION BEHIND THE FRONT WILL DROP
SUN TEMPS BELOW CLIMO...BUT COLD AIR WILL BE A LITTLE TOO LATE TO
HAVE A SIGNIFICANT IMPACT ON SAT NIGHT LOWS WHICH WILL END UP NEAR
TO SLIGHTLY ABOVE CLIMO. SUN SHOULD BE DRY WITH DEEP NORTHWEST FLOW
BEHIND THE TROUGH DROPPING PWATS UNDER .5 INCH FOR SUN AM AND UNDER
.25 INCH BY SUN EVENING. GRADIENT RELAXES SUN NIGHT BUT HIGH REMAINS
WEST OF THE AREA THROUGH THE END OF THE PERIOD SO SUN NIGHT WILL NOT
BE AN IDEAL RADIATIONAL COOLING NIGHT. STILL LOWS END UP BELOW CLIMO.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...LOW AMPLITUDE MID LEVEL RIDGING AND SPRAWLING
SURFACE HIGH WILL KEEP THE AREA DRY AND SEASONABLE THROUGH THE
PERIOD. COOLEST DAY WILL BE MON WITH SURFACE HIGH DIRECTLY OVERHEAD.
HIGH THEN DRIFTS OFFSHORE TUE THROUGH THU BRINGING SEVERAL DAYS OF
BEAUTIFUL SPRING WEATHER. PREVIOUSLY MEDIUM RANGE GUIDANCE HAD BEEN
MOVING A DRY COLD FRONT ACROSS THE AREA TUE NIGHT INTO WED. NOW THAT
GUIDANCE IS SUGGESTING MORE MID LEVEL AMPLIFICATION THIS SEEMS
UNLIKELY AND IN FACT THE 00Z GUIDANCE IS BACKING OFF ON THE DRY
FRONT. TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO MON TRANSITION TO
ABOVE CLIMO MON NIGHT THROUGH THE END OF THE PERIOD.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...RETURN FLOW WILL COMMENCE SHORTLY. HAVE LEANED FAIRLY
HEAVILY ON THE HRRR EARLY...WITH SHOWERS POPPING UP ALONG THE
MYRTLES BY LATE MORNING. INCREASING SOUTHERLY GRADIENT WILL CAUSE
WINDS TO GUSTS OVER 20 KTS AT TIMES...ESPECIALLY ALONG THE COAST.
SCATTERED SHOWERS WILL GIVE WAY TO MORE WIDESPREAD RAIN THIS EVENING
AS DEEP MOISTURE MOVES INTO THE REGION. RAIN CHANCES WILL BE HIGHEST
INLAND THIS EVENING...SPREADING TO THE COAST A FEW HOURS LATER.
CEILINGS ARE A BIT PROBLEMATIC...BUT WILL GO FOR MVFR PREDOMINATELY
WITH POCKETS OF IFR POSSIBLE.
EXTENDED OUTLOOK...SHOWERS AND T-STORMS WITH MVFR/TEMPO IFR
CONDITIONS OVERNIGHT AND ON SATURDAY. VFR SUNDAY THROUGH TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM FRIDAY...THE PRESSURE GRADIENT BETWEEN A LARGE AREA OF
HIGH PRESSURE OFFSHORE AND A TROUGH OF LOW PRESSURE TO OUR W WILL
BE TIGHTEST TONIGHT...ESPECIALLY LATE TONIGHT AND SAT AS THE
TROUGH BEGINS TO MAKE ITS EASTWARD PUSH. THUS THIS IS WHEN THE
STRONGEST WINDS ARE EXPECTED ACROSS THE WATERS. THE STRONGEST
WINDS ARE EXPECTED ACROSS THE OUTERMOST WATERS AND EASTWARD WHERE
SEA SURFACE TEMPS ARE MUCH HIGHER THAN ACROSS THE NEAR SHORE
WATERS...THUS ALLOWING FOR THE GREATEST MIXING. WIND SPEEDS WITHIN
20 NM OF THE COAST WILL BE AS HIGH AS 15 TO 20 KT. PERSISTENTLY
HIGHER SOUTH WINDS OFFSHORE WILL ALLOW SEAS TO BUILD AND EXPECT
THE 6 FT THRESHOLD WILL BE MET ACROSS PORTIONS OF THE OUTER WATERS
AS EARLY AS THIS AFTERNOON AND MORESO TONIGHT...NECESSITATING A
SMALL CRAFT ADVISORY WHICH WILL BE RAISED AT THIS TIME.
FINALLY...HIGHER DEWPOINTS ADVECTING NORTHWARD AHEAD OF AN
APPROACHING TROUGH SHOULD ALLOW FOR THE DEVELOPMENT OF SEA
FOG...LIKELY MOST PREVALENT OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SOUTHERLY FLOW WILL APPROACH 20 KT SAT AS
GRADIENT OVER THE WATERS IS PINCHED BETWEEN ADVANCING COLD FRONT AND
HIGH PRESSURE. ANTICIPATE A LINE OF CONVECTION AHEAD OF THE FRONT
WHICH WILL CROSS THE WATERS SAT EVE/NIGHT. OFFSHORE FLOW DEVELOPS
BEHIND THE FRONT WITH GRADIENT AND DEVELOPING COLD ADVECTION KEEPING
SPEEDS AROUND 20 KT. LITTLE CHANGE IN THE GRADIENT SUN AS HIGH
BUILDS KEEPS NORTHWEST WINDS A SOLID 20 KT FOR MUCH OF THE DAY.
OFFSHORE FLOW SLOWLY WEAKENS SUN NIGHT...DROPPING TO 15 KT BY THE
END OF THE PERIOD...AS GRADIENT RELAXES. SEAS 4 TO 6 FT EXPECTED SAT
INTO SUN WHEN OFFSHORE COMPONENT DROPS SEAS TO 3 TO 5 FT. CONTINUED
OFFSHORE FLOW COMBINED WITH REDUCTION IN SPEEDS SUN NIGHT WILL DROP
SEAS TO 2 TO 4 FT BY THE END OF THE PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...OFFSHORE FLOW AROUND 15 KT AT THE START OF THE
PERIOD WILL DECREASE DURING MON AS HIGH PRESSURE MOVES OVER HEAD.
SPEEDS WILL DROP UNDER 10 KT BY MON EVENING...BECOMING LIGHT AND
VARIABLE MON NIGHT. HIGH SHIFTS OFFSHORE FOR TUE WITH RETURN FLOW
SLOWLY RISING INTO THE 10 TO 15 KT RANGE LATE TUE AND TUE NIGHT.
SEAS WILL RUN 2 TO 3 FT FOR A MAJORITY OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT
SATURDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...SGL/RJD
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
948 AM EDT FRI MAR 28 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL PULL A COLD FRONT EAST ACROSS THE AREA
TODAY. ANOTHER LOW PRESSURE SYSTEM WILL TRACK THROUGH THE TENNESSEE
AND LOWER OHIO VALLEY ON SATURDAY. HIGH PRESSURE OVER THE UPPER
GREAT LAKES WILL EXPAND SOUTH ON SUNDAY...THEN SHIFT EAST OF THE
AREA ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT WAS OVER NORTHWEST OHIO AND IT WILL REACH NORTHWEST
PA THIS AFTERNOON. WINDS CAN STILL BE GUSTY AHEAD OF THE FRONT BUT
BELOW WIND ADVISORY CRITERIA. SCATTERED SHOWERS WILL BE DEVELOPING
THROUGH THE MORNING AND INTO THE AFTERNOON. TEMPERATURES ARE
PEAKING NOW AND WILL SLOWLY FALL AFTER THE FRONTAL PASSAGE.
PREVIOUS DISCUSSION...
WINDS HAVE BEEN GUSTING BETWEEN 40-45 MPH (WITH EVEN A PEAK WIND
TO 50 MPH AT FINDLAY) EARLY THIS MORNING ACROSS NW AND NORTH
CENTRAL OHIO. THIS HAS BEEN OCCURRING WELL OUT AHEAD OF THE FRONT
IN THE VICINITY OF THE LOW LEVEL JET. HAVE CONTEMPLATED ISSUING A
WIND ADVISORY BUT WINDS SHOULD ONLY BE THAT STRONG FOR A COUPLE
HOUR WINDOW AT ANY GIVEN LOCATION BEFORE DECREASING WITH GUSTS
CLOSER TO 35 MPH AS WE HAVE SEEN UPSTREAM IN INDIANA AND EVEN NW
OHIO NOW. THE RUC SHOWS A DECREASING TREND FOR THE LOW LEVEL JET
AND THE HRRR HAS BEEN HIGHLIGHTING THE STRONGEST CORRIDOR OF WINDS
FROM FDY/MNN/MFD TO CLE. WINDS SHOULD START TO DECREASE FROM MFD-
CLE THROUGH 9 AM SO WILL HOLD OFF ON AN ADVISORY. NORTHEAST OHIO
WILL STILL SEE WINDS INCREASE BUT HOPEFULLY GUSTS WILL NOT BE
QUITE AS STRONG...HOLDING CLOSER TO 40 MPH FOR THE MOST PART.
WINDS WILL GUST TO AROUND 40 MPH AGAIN WITH THE FRONTAL PASSAGE
BUT THESE WILL ALSO BE BRIEF.
EARLIER DISCUSSION...
LOW PRESSURE CURRENTLY LOCATED OVER LAKE MICHIGAN WITH A COLD FRONT
EXTENDING SOUTH ACROSS ILLINOIS. WINDS HAVE BEEN INCREASING AHEAD OF
THE FRONT AND SEVERAL SITES IN INDIANA AND WESTERN OHIO HAVE BRIEFLY
GUSTED TO AROUND 40 MPH. EXPECT TO SEE THE BREEZY WINDS EXPAND
EASTWARD AND THROUGH THE EARLY MORNING HOURS WITH GUSTS IN THE 30-40
MPH RANGE...WITH LOCALLY HIGHER GUSTS TOWARDS ERIE PA WHERE
DOWNSLOPING MAY ENHANCE THE WINDS. NOT ENTIRELY OUT OF THE QUESTION
THAT WE MAY NEED A WIND ADVISORY FOR A FEW HOURS THIS MORNING IN
ERIE BUT STILL LOOKING JUST A LITTLE TOO MARGINAL TO ISSUE AT THIS
TIME AS WINDS TRY TO SHIFT TO MORE SSW WHICH IS LESS FAVORABLE.
TEMPERATURES WILL PEAK IN THE LOW 50S THIS MORNING IMMEDIATELY AHEAD
OF THE FRONT WHICH WILL REACH TOL AROUND 9 AM...CLE AROUND NOON AND
ERI EARLY THIS AFTERNOON. TEMPERATURES WILL FALL INTO THE MID AND
UPPER 40S BEHIND THE FRONT MOST AREAS THIS AFTERNOON.
ONE MORE BAND OF SHOWERS EXTENDS FROM FINDLAY SOUTHWEST AHEAD OF THE
MID-LEVEL DRY-SLOT. THIS AREA OF SHOWERS EXPECTED TO QUICKLY MOVE
NORTHEAST ACROSS OHIO THIS MORNING....WITH JUST A SLIGHT CHANCE OF
ADDITIONAL SHOWERS RE-DEVELOPING ALONG THE FRONT. THE AIR MASS DRIES
OUT QUICKLY BY THIS AFTERNOON AS A SHORTWAVE RIDGE BUILD ALOFT.
SKIES WILL START TO SCATTER OUT IN NW OHIO THIS AFTERNOON...POSSIBLY
AS FAR EAST AS CLE/CAK BY SUNSET.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
SKIES WILL CLEAR OUT THIS EVENING WITH NORTH TO NORTHEAST FLOW ON
THE SOUTHERN PERIPHERY OF HIGH PRESSURE BUILD OVER THE UPPER GREAT
LAKES. LOWS WILL FALL INTO THE LOW 30S TONIGHT.
THE FORECAST REMAINS A CHALLENGE FOR SATURDAY AS MODELS CONTINUE TO
SHOW SPREAD WITH THERMAL PROFILES WHICH WILL HAVE AN EFFECT ON
PRECIPITATION TYPE. SHORTWAVE ENERGY OBSERVED OVER THE ROCKY
MOUNTAINS THIS MORNING WILL DEEPEN INTO A FAIRLY SHARP TROUGH AS
IT CROSSES THE MISSISSIPPI VALLEY ON SATURDAY. A SURFACE LOW WILL
DEEPEN AHEAD OF THIS FEATURE...TRACKING NORTHEAST FROM THE
TENNESSEE TO LOWER OHIO VALLEY. FRONTOGENESIS WILL STRENGTHEN OVER
THE AREA IN THE 850-700MB LAYER LEADING TO WIDESPREAD
PRECIPITATION. THERE WILL BE A DRY NORTHERLY FLOW IN THE LOW
LEVELS TO START THE DAY WHICH MAY SLIGHTLY DELAY PRECIPITATION.
MODELS VARY WITH HOW MUCH WARM AIR WILL BE IN PLACE ALOFT TO START
THE DAY WITH THE ECMWF ADVERTISING A WARM LAYER OF 1-3C NEAR 850MB
WHILE THE GFS ALSO STARTS THE DAY OFF WARM IN THE EASTERN
CWA...BUT QUICKLY COOLS THE COLUMN FROM WEST TO EAST. SUSPECT WE
WILL SEE WESTERN AREAS MAKE A QUICK TRANSITION TO A WET SNOW ON
SATURDAY MORNING WHILE RAIN IS MORE PREVALENT EAST OF ABOUT I-71.
GOOD PRECIPITATION RATES ARE EXPECTED AS A NUMBER OF FACTORS COME
TOGETHER...INCLUDING FAVORABLE JET DYNAMICS ALOFT.
THE SNOWFALL FORECAST IS COMPLICATED GIVEN IT BEING A DAYTIME SNOW
EVENT AT THE END OF MARCH. SNOW WILL ACCUMULATE BETTER ON GRASSY
SURFACES THAN ROADWAYS...ESPECIALLY AS TEMPERATURES HOVER IN THE
LOW TO MID 30S. THE SNOW WILL BE WET WHICH WILL LEAD TO MORE
COMPACTION. HAVE GONE WITH A BLEND OF THE COOLER GFS/NAM AND
WARMER ECMWF/GEM WITH REGARD TO PRECIP TYPE BUT LEANING TOWARDS
THE LOWER ACCUMULATIONS GIVEN THE LIMITATIONS MENTIONED ABOVE.
GOING WITH A PURE 00Z/GFS SOLUTION COULD YIELD AS MUCH AS 3-5
INCHES FOR A CORRIDOR FROM CLE/ERI AS SNOW STARTS TO ACCUMULATE
MORE EFFICIENTLY AS WE HEAD TOWARDS SUNSET. THE GOING FORECAST
ONLY CALLS FOR A COUPLE INCHES BUT MAY NEED TO BE RAMPED UP BASED
ON LATER MODEL GUIDANCE. DID ADJUST HIGH TEMPERATURES DOWN A FEW
DEGREES ON SATURDAY WITH LITTLE DIURNAL RISE.
PRECIPITATION WILL COME TO AN END ON SATURDAY NIGHT WITH LITTLE
INFLUENCE FROM LAKE ERIE GIVEN 850MB TEMPERATURES ONLY DROPPING TO
AROUND -4C. HIGH PRESSURE THEN BUILDS OVER THE AREA ON SUNDAY WITH
MOSTLY SUNNY SKIES. SOUTHERLY FLOW RETURNS ON MONDAY AHEAD OF THE
NEXT SYSTEM WITH HIGHS IN THE UPPER 50S TO LOW 60S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
THE MODELS CONTINUE TO BE SIMILAR IN THEIR FORECASTS WITH SOME MINOR
DETAILS TO BE WORKED OUT. A COLD FRONT WILL CROSS THE AREA ON
TUESDAY. THE ECMWF HAS BECOME SLOWER THAN THE OTHER MODELS AND
CONSEQUENTLY IS WARMER (60S VERSUS 50S FOR HIGHS). WOULD RATHER
REMAIN CONSERVATIVE AND NEAR THE CURRENT FORECAST UNTIL WE SEE A
MORE DEFINITE TREND.
THE NEXT PANHANDLE HOOK IS PROGGED TO COME OUT OF THE SOUTHERN
PLAINS BY WEDNESDAY NIGHT AND MOVE TO THE GREAT LAKES ON THURSDAY.
INCREASED THE CHANCE OF RAIN IN THE FORECAST FOR WEDNESDAY NIGHT AND
THURSDAY. WE MAY TAKE A WHILE TO BREAK INTO THE WARM SECTOR WITH AN
EAST FLOW PROGGED FOR A WHILE WEDNESDAY INTO THURSDAY SO DID NOT GO
AS WARM AS IT COULD BE FOR HIGH TEMPS AND DID NOT MENTION THUNDER...
THERE IS PLENTY OF TIME TO TREND THE FORECAST IN THAT DIRECTION IF
NECESSARY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
WILL ALLOW FOR SHOWERS AT THE EASTERN TAF SITES KCAK KYNG KERI
EARLY THIS MORNING. CANNOT RULE OUT A BRIEF SHOWER/SPRINKLE WHEN
THE ACTUAL FRONT MOVES THROUGH MID MORNING THROUGH EARLY AFTERNOON
BUT DID NOT INCLUDE IT IN THE FORECAST. CEILINGS WILL LOWER TO
MVFR AFTER FRONTAL PASSAGE. GUSTY SOUTH WINDS WILL BECOME
SOUTHWEST AND EVENTUALLY WEST...THEN DIMINISH QUICKLY LATE THIS
AFTERNOON/EARLY EVENING. GUSTS 35 TO NEAR 40 KNOTS THIS MORNING.
CLEARING AND VFR CONDITIONS WILL SPREAD FROM WEST TO EAST LATE
THIS AFTERNOON AND THIS EVENING. MID AND HIGH CLOUDS WILL INCREASE
SATURDAY MORNING.
.OUTLOOK...NON VFR WILL REDEVELOP SAT AND PERSIST ACROSS NE OH/NW
PA INTO SUNDAY. NON VFR POSSIBLE AGAIN TUE.
&&
.MARINE...
THE STRONG LOW LEVEL JET WILL BE OVER LAKE ERIE THIS MORNING BUT
WITH THE LAKE STILL SO COLD IT IS UNLIKELY THE WIND WILL MIX
DOWN TO THE SURFACE. SOUTH WINDS OF 20-30 KNOTS SHOULD DO IT THIS
MORNING. THERE COULD BE BETTER MIXING AS THE FRONT CROSSES THE LAKE
FROM MID MORNING THROUGH MID AFTERNOON AND AN OBSERVATION OR TWO
NEAR 35 KNOTS IS POSSIBLE BUT DO NOT WANT TO ISSUE A GALE WARNING
FOR AN ISOLATED/BRIEF EVENT.
HIGH PRESSURE WILL BUILD IN QUICKLY TONIGHT. THE NEXT LOW PRESSURE
SYSTEM WILL PASS SOUTH OF THE LAKE ON SATURDAY AND WINDS WILL VEER
TO THE NORTH AND NORTHEAST. NNE WINDS COULD BECOME BRISK ON
SATURDAY...THERE IS STILL SOME UNCERTAINTY ON THE TRACK AND
STRENGTH OF THE LOW. HIGH PRESSURE IS EXPECTED TO SPREAD ACROSS THE
EASTERN GREAT LAKES SUNDAY INTO MONDAY. THE NEXT LOW WILL TRACK
ACROSS THE WESTERN GREAT LAKES BY MONDAY NIGHT WITH WINDS ON LAKE
ERIE INCREASING WITH THE NEXT COLD FRONT ON TUESDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/KIELTYKA
SHORT TERM...KEC
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
737 AM EDT FRI MAR 28 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL PULL A COLD FRONT EAST ACROSS THE AREA
TODAY. ANOTHER LOW PRESSURE SYSTEM WILL TRACK THROUGH THE TENNESSEE
AND LOWER OHIO VALLEY ON SATURDAY. HIGH PRESSURE OVER THE UPPER
GREAT LAKES WILL EXPAND SOUTH ON SUNDAY...THEN SHIFT EAST OF THE
AREA ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WINDS HAVE BEEN GUSTING BETWEEN 40-45 MPH (WITH EVEN A PEAK WIND TO
50 MPH AT FINDLAY) EARLY THIS MORNING ACROSS NW AND NORTH CENTRAL
OHIO. THIS HAS BEEN OCCURRING WELL OUT AHEAD OF THE FRONT IN THE
VICINITY OF THE LOW LEVEL JET. HAVE CONTEMPLATED ISSUING A WIND
ADVISORY BUT WINDS SHOULD ONLY BE THAT STRONG FOR A COUPLE HOUR
WINDOW AT ANY GIVEN LOCATION BEFORE DECREASING WITH GUSTS CLOSER TO
35 MPH AS WE HAVE SEEN UPSTREAM IN INDIANA AND EVEN NW OHIO NOW. THE
RUC SHOWS A DECREASING TREND FOR THE LOW LEVEL JET AND THE HRRR HAS
BEEN HIGHLIGHTING THE STRONGEST CORRIDOR OF WINDS FROM FDY/MNN/MFD
TO CLE. WINDS SHOULD START TO DECREASE FROM MFD-CLE THROUGH 9 AM SO
WILL HOLD OFF ON AN ADVISORY. NORTHEAST OHIO WILL STILL SEE WINDS
INCREASE BUT HOPEFULLY GUSTS WILL NOT BE QUITE AS STRONG...HOLDING
CLOSER TO 40 MPH FOR THE MOST PART. WINDS WILL GUST TO AROUND 40
MPH AGAIN WITH THE FRONTAL PASSAGE BUT THESE WILL ALSO BE BRIEF.
EARLIER DISCUSSION...
LOW PRESSURE CURRENTLY LOCATED OVER LAKE MICHIGAN WITH A COLD FRONT
EXTENDING SOUTH ACROSS ILLINOIS. WINDS HAVE BEEN INCREASING AHEAD OF
THE FRONT AND SEVERAL SITES IN INDIANA AND WESTERN OHIO HAVE BRIEFLY
GUSTED TO AROUND 40 MPH. EXPECT TO SEE THE BREEZY WINDS EXPAND
EASTWARD AND THROUGH THE EARLY MORNING HOURS WITH GUSTS IN THE 30-40
MPH RANGE...WITH LOCALLY HIGHER GUSTS TOWARDS ERIE PA WHERE
DOWNSLOPING MAY ENHANCE THE WINDS. NOT ENTIRELY OUT OF THE QUESTION
THAT WE MAY NEED A WIND ADVISORY FOR A FEW HOURS THIS MORNING IN
ERIE BUT STILL LOOKING JUST A LITTLE TOO MARGINAL TO ISSUE AT THIS
TIME AS WINDS TRY TO SHIFT TO MORE SSW WHICH IS LESS FAVORABLE.
TEMPERATURES WILL PEAK IN THE LOW 50S THIS MORNING IMMEDIATELY AHEAD
OF THE FRONT WHICH WILL REACH TOL AROUND 9 AM...CLE AROUND NOON AND
ERI EARLY THIS AFTERNOON. TEMPERATURES WILL FALL INTO THE MID AND
UPPER 40S BEHIND THE FRONT MOST AREAS THIS AFTERNOON.
ONE MORE BAND OF SHOWERS EXTENDS FROM FINDLAY SOUTHWEST AHEAD OF THE
MID-LEVEL DRY-SLOT. THIS AREA OF SHOWERS EXPECTED TO QUICKLY MOVE
NORTHEAST ACROSS OHIO THIS MORNING....WITH JUST A SLIGHT CHANCE OF
ADDITIONAL SHOWERS RE-DEVELOPING ALONG THE FRONT. THE AIR MASS DRIES
OUT QUICKLY BY THIS AFTERNOON AS A SHORTWAVE RIDGE BUILD ALOFT.
SKIES WILL START TO SCATTER OUT IN NW OHIO THIS AFTERNOON...POSSIBLY
AS FAR EAST AS CLE/CAK BY SUNSET.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
SKIES WILL CLEAR OUT THIS EVENING WITH NORTH TO NORTHEAST FLOW ON
THE SOUTHERN PERIPHERY OF HIGH PRESSURE BUILD OVER THE UPPER GREAT
LAKES. LOWS WILL FALL INTO THE LOW 30S TONIGHT.
THE FORECAST REMAINS A CHALLENGE FOR SATURDAY AS MODELS CONTINUE TO
SHOW SPREAD WITH THERMAL PROFILES WHICH WILL HAVE AN EFFECT ON
PRECIPITATION TYPE. SHORTWAVE ENERGY OBSERVED OVER THE ROCKY
MOUNTAINS THIS MORNING WILL DEEPEN INTO A FAIRLY SHARP TROUGH AS
IT CROSSES THE MISSISSIPPI VALLEY ON SATURDAY. A SURFACE LOW WILL
DEEPEN AHEAD OF THIS FEATURE...TRACKING NORTHEAST FROM THE
TENNESSEE TO LOWER OHIO VALLEY. FRONTOGENESIS WILL STRENGTHEN OVER
THE AREA IN THE 850-700MB LAYER LEADING TO WIDESPREAD
PRECIPITATION. THERE WILL BE A DRY NORTHERLY FLOW IN THE LOW
LEVELS TO START THE DAY WHICH MAY SLIGHTLY DELAY PRECIPITATION.
MODELS VARY WITH HOW MUCH WARM AIR WILL BE IN PLACE ALOFT TO START
THE DAY WITH THE ECMWF ADVERTISING A WARM LAYER OF 1-3C NEAR 850MB
WHILE THE GFS ALSO STARTS THE DAY OFF WARM IN THE EASTERN
CWA...BUT QUICKLY COOLS THE COLUMN FROM WEST TO EAST. SUSPECT WE
WILL SEE WESTERN AREAS MAKE A QUICK TRANSITION TO A WET SNOW ON
SATURDAY MORNING WHILE RAIN IS MORE PREVALENT EAST OF ABOUT I-71.
GOOD PRECIPITATION RATES ARE EXPECTED AS A NUMBER OF FACTORS COME
TOGETHER...INCLUDING FAVORABLE JET DYNAMICS ALOFT.
THE SNOWFALL FORECAST IS COMPLICATED GIVEN IT BEING A DAYTIME SNOW
EVENT AT THE END OF MARCH. SNOW WILL ACCUMULATE BETTER ON GRASSY
SURFACES THAN ROADWAYS...ESPECIALLY AS TEMPERATURES HOVER IN THE
LOW TO MID 30S. THE SNOW WILL BE WET WHICH WILL LEAD TO MORE
COMPACTION. HAVE GONE WITH A BLEND OF THE COOLER GFS/NAM AND
WARMER ECMWF/GEM WITH REGARD TO PRECIP TYPE BUT LEANING TOWARDS
THE LOWER ACCUMULATIONS GIVEN THE LIMITATIONS MENTIONED ABOVE.
GOING WITH A PURE 00Z/GFS SOLUTION COULD YIELD AS MUCH AS 3-5
INCHES FOR A CORRIDOR FROM CLE/ERI AS SNOW STARTS TO ACCUMULATE
MORE EFFICIENTLY AS WE HEAD TOWARDS SUNSET. THE GOING FORECAST
ONLY CALLS FOR A COUPLE INCHES BUT MAY NEED TO BE RAMPED UP BASED
ON LATER MODEL GUIDANCE. DID ADJUST HIGH TEMPERATURES DOWN A FEW
DEGREES ON SATURDAY WITH LITTLE DIURNAL RISE.
PRECIPITATION WILL COME TO AN END ON SATURDAY NIGHT WITH LITTLE
INFLUENCE FROM LAKE ERIE GIVEN 850MB TEMPERATURES ONLY DROPPING TO
AROUND -4C. HIGH PRESSURE THEN BUILDS OVER THE AREA ON SUNDAY WITH
MOSTLY SUNNY SKIES. SOUTHERLY FLOW RETURNS ON MONDAY AHEAD OF THE
NEXT SYSTEM WITH HIGHS IN THE UPPER 50S TO LOW 60S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
THE MODELS CONTINUE TO BE SIMILAR IN THEIR FORECASTS WITH SOME MINOR
DETAILS TO BE WORKED OUT. A COLD FRONT WILL CROSS THE AREA ON
TUESDAY. THE ECMWF HAS BECOME SLOWER THAN THE OTHER MODELS AND
CONSEQUENTLY IS WARMER (60S VERSUS 50S FOR HIGHS). WOULD RATHER
REMAIN CONSERVATIVE AND NEAR THE CURRENT FORECAST UNTIL WE SEE A
MORE DEFINITE TREND.
THE NEXT PANHANDLE HOOK IS PROGGED TO COME OUT OF THE SOUTHERN
PLAINS BY WEDNESDAY NIGHT AND MOVE TO THE GREAT LAKES ON THURSDAY.
INCREASED THE CHANCE OF RAIN IN THE FORECAST FOR WEDNESDAY NIGHT AND
THURSDAY. WE MAY TAKE A WHILE TO BREAK INTO THE WARM SECTOR WITH AN
EAST FLOW PROGGED FOR A WHILE WEDNESDAY INTO THURSDAY SO DID NOT GO
AS WARM AS IT COULD BE FOR HIGH TEMPS AND DID NOT MENTION THUNDER...
THERE IS PLENTY OF TIME TO TREND THE FORECAST IN THAT DIRECTION IF
NECESSARY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
WILL ALLOW FOR SHOWERS AT THE EASTERN TAF SITES KCAK KYNG KERI
EARLY THIS MORNING. CANNOT RULE OUT A BRIEF SHOWER/SPRINKLE WHEN
THE ACTUAL FRONT MOVES THROUGH MID MORNING THROUGH EARLY AFTERNOON
BUT DID NOT INCLUDE IT IN THE FORECAST. CEILINGS WILL LOWER TO
MVFR AFTER FRONTAL PASSAGE. GUSTY SOUTH WINDS WILL BECOME
SOUTHWEST AND EVENTUALLY WEST...THEN DIMINISH QUICKLY LATE THIS
AFTERNOON/EARLY EVENING. GUSTS 35 TO NEAR 40 KNOTS THIS MORNING.
CLEARING AND VFR CONDITIONS WILL SPREAD FROM WEST TO EAST LATE
THIS AFTERNOON AND THIS EVENING. MID AND HIGH CLOUDS WILL INCREASE
SATURDAY MORNING.
.OUTLOOK...NON VFR WILL REDEVELOP SAT AND PERSIST ACROSS NE OH/NW
PA INTO SUNDAY. NON VFR POSSIBLE AGAIN TUE.
&&
.MARINE...
THE STRONG LOW LEVEL JET WILL BE OVER LAKE ERIE THIS MORNING BUT
WITH THE LAKE STILL SO COLD IT IS UNLIKELY THE WIND WILL MIX
DOWN TO THE SURFACE. SOUTH WINDS OF 20-30 KNOTS SHOULD DO IT THIS
MORNING. THERE COULD BE BETTER MIXING AS THE FRONT CROSSES THE LAKE
FROM MID MORNING THROUGH MID AFTERNOON AND AN OBSERVATION OR TWO
NEAR 35 KNOTS IS POSSIBLE BUT DO NOT WANT TO ISSUE A GALE WARNING
FOR AN ISOLATED/BRIEF EVENT.
HIGH PRESSURE WILL BUILD IN QUICKLY TONIGHT. THE NEXT LOW PRESSURE
SYSTEM WILL PASS SOUTH OF THE LAKE ON SATURDAY AND WINDS WILL VEER
TO THE NORTH AND NORTHEAST. NNE WINDS COULD BECOME BRISK ON
SATURDAY...THERE IS STILL SOME UNCERTAINTY ON THE TRACK AND
STRENGTH OF THE LOW. HIGH PRESSURE IS EXPECTED TO SPREAD ACROSS THE
EASTERN GREAT LAKES SUNDAY INTO MONDAY. THE NEXT LOW WILL TRACK
ACROSS THE WESTERN GREAT LAKES BY MONDAY NIGHT WITH WINDS ON LAKE
ERIE INCREASING WITH THE NEXT COLD FRONT ON TUESDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
746 AM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT WILL ENTER OUR REGION BY TONIGHT. ANOTHER AREA OF
LOW PRESSURE WILL RIDE EASTWARD ALONG THE STALLED FRONT FROM THE
MIDDLE MISSISSIPPI VALLEY ON SATURDAY. THIS FRONT WILL EXIT THE
COAST SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM EDT FRIDAY...
WINDS EARLY THIS MORNING WILL STAY GUSTY OVER THE HIGHER RIDGES AND
THROUGH SOME GAPS ON THE NORTH SIDE OF TWO MOUNTAINS. NOT GETTING
ANY REPORTS OF WIND DAMAGE/POWER OUTAGES...BUT HAD ONE SPOTTER
REPORT GUSTS OVER 50 MPH PER WIND INSTRUMENT. GIVEN LACK OF COVERAGE
OVERALL AND WITH SFC/LOW LVL FLOW STARTING TO VEER MORE TOWARD SOUTH
TO SSW...AN ADVISORY IS NOT NEEDED. OUR TYPICAL WINDIEST PLACES IN
THIS PATTERN HAVE ONLY GUSTED TO 42 MPH IN TAZEWELL COUNTY. AN SPS
WAS ISSUED TO COVER THE HIGHER RIDGES UNTIL THE LOW LVL JET LIFTS
NORTH.
RAIN SHOWERS FORMING ALONG WEAK THETA-E RIDGE AHEAD OF THE MAIN
SYSTEM OVER THE NEW RIVER VALLEY THIS MORNING AND BLUE RIDGE. MAINLY
WILL SEE ISOLATED/SCATTERED COVERAGE EARLY BEFORE MAIN LINE BATCH
MOVES IN AFTER 12Z. STILL NOT SEEING WIDESPREAD COVERAGE BUT ENOUGH
TO WARRANT LIKELY TO CATEGORICAL POPS OVER THE WEST LATER THIS
MORNING...AS THETA-E RIDGE SHIFTS FROM FAR SW VA INTO THE NRN VA
AREA. THE LATEST HRRR IS HANDLING THIS PRETTY WELL IN REGARDS TO
PRECIP AND SHOWS POTENTIAL BREAK IN THE ACTION MID MORNING...AS ONE
AREA OF SHOWERS MOVES INTO THE SHENANDOAH VALLEY...AND THE NEXT AREA
SLIDING NORTHEAST TOWARD THE NC MTNS/FAR SW VA AGAIN BY MIDDAY. WILL
LEAN THIS MORNING POPS THIS WAY...BLENDING TOWARD A GFS/SREF/ECMWF
SOLUTION BY AFTERNOON. GFS DRYING IT FASTER WHICH AGREES WITH THE
00Z WRF/HRRR TO SOME EXTENT AS WELL AS THE 00Z NAM. THIS AFTERNOON
WILL HAVE CHANCE POPS ACROSS THE NRN CWA TO LIKELY IN THE SRN TIER
FROM THE NC MTNS TO SOUTHSIDE VA...WITH POTENTIAL FOR SLIGHT CHANCE
TO NO CHANCE RAIN AROUND 00Z NORTH OF INTERSTATE 64.
TEMPS WILL BE MILD TODAY BUT CLOUDS/RAIN SHOWERS WILL HELP TO KEEP
THEM COOLER THAN NORMAL. MAV/MET BLEND SEEMS TO HANDLE THIS BEST.
LOOK FOR HIGHS FROM THE LOWER TO MID 50S NORTH CAROLINA MTNS/SRN
BLUE RIDGE OF VA TO LOWER TO MID 60S ACROSS THE MTN EMPIRE AS WELL
AS THE PIEDMONTS AND ROANOKE VALLEY.
TONIGHT...A DRYING OUT SOME ALOFT WITH LOW LVL MOISTURE STAYING
CLOSE AT HAND...SO WILL SEE SOME LIGHT RAIN EARLY IN THE SOUTH WITH
MAIN WAVE OF LOW PRESSURE TRACKING TOWARD MID TN/SRN KY BY LATE
TONIGHT. THIS WILL BUCKLE THE FRONT NORTH AGAIN WITH CATEGORICAL
RAIN RETURNING FROM SOUTH TO NORTH OVERNIGHT. MILD LOWS IN THE
40S...LOWER 50S.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AN UPPER LEVEL TROUGH WILL TRACK EAST OVER THE MID WEST
GENERATING A SURFACE LOW THAT WILL TRACK ALONG THE FRONTAL
BOUNDARY SATURDAY MORNING. THE UPPER LEVEL TROUGH WILL START TO
CLOSE OFF SATURDAY AFTERNOON...WITH A NEW SURFACE LOW DEVELOPING
ALONG THE LEE SIDE OF THE SOUTHERN APPALACHIANS. THIS SURFACE LOW
IS EXPECTED TO TRACK ACROSS THE CAROLINA-VIRGINIA PIEDMONT
SATURDAY AFTERNOON/EVENING...THEN OFF THE DELMARVA COAST SATURDAY
NIGHT. THE GFS HAS THE CLOSED UPPER LOW OVER WEST VIRGINIA
SATURDAY EVENING...TRACKING OVER THE FORECAST AREA AND ACROSS
SOUTHERN VIRGINIA SUNDAY MORNING. THE NAM/ECM HAS THE CLOSED LOW
SLIGHTLY FARTHER TO THE SOUTH...TRACKING FROM SOUTHWESTERN
VIRGINIA SATURDAY EVENING...ACROSS NORTH CAROLINA THROUGH THE
MORNING...THEN OFF THE NORTH CAROLINA COAST BY SUNDAY EVENING.
WITH AMPLE MOISTURE AND GOOD JET DYNAMICS...MOST OF SATURDAY WILL BE
WET. THE GOOD NEWS IS THAT IT WILL FALL AS RAIN AND NOT SNOW. AS THE
SECOND LOW TAKES SHAPE AND RACES NORTHEAST OF THE AREA SATURDAY
EVENING...A DRY SLOT WILL TEMPORARILY END THE RAIN SHOWERS. RAIN
SHOWERS RE-ENTERS THE AREA AS THE UPPER LEVEL LOW TRACKS EAST
THROUGH SUNDAY MORNING. TEMPERATURES SHOULD REMAIN WARM ENOUGH ON
THE FRONT END OF THIS LOW TO KEEP P-TYPE AS LIQUID. ON THE BACK
SIDE...COLD AIR AND WRAP-AROUND MOISTURE MAY CHANGE RAIN OVER TO
SNOW/GRAUPEL FOR THE MOUNTAINS...POSSIBLY EAST OF THE BLUE RIDGE
SUNDAY MORNING. CAN NOT RULE OUT A STRIKE OR TWO OF LIGHTNING AS THE
UPPER LOW MOVES OVERHEAD...BUT WILL LEAVE OUT OF THE WEATHER GRIDS
WITH IT TRACKING OVER IN THE MORNING. BY SUNDAY
EVENING...PRECIPITATION WILL BE EAST OF THE AREA...THEN THE WINDS
WILL PICK UP FROM THE NORTH-NORTHWEST. HIGH PRESSURE BUILDS IN
QUICKLY TO CONFINE STRONGEST WINDS TO A 12 HOUR PERIOD
SUNDAY...WEAKENING THROUGH THE NIGHT.
RAINFALL AMOUNTS SATURDAY INTO SATURDAY EVENING WILL RANGE FROM A
THIRD TO THREE-QUARTERS OF AN INCH. IF TODAYS RAIN IS SIGNIFICANT
ENOUGH AND MODELS MAINTAIN SIMILAR QPF TOTALS FOR SATURDAY...A FLOOD
WATCH MAY BE ISSUED. CONFIDENCE IS LOW AT THIS TIME.
CONSIDER WINTERS GRIP ON THE AREA THIS YEAR...HESITANT TO GO WITH A
LITTLE IF ANY SNOWFALL STATEMENT. BOTH THE NAM AND ECM PAINT A
DUSTING TO AN INCH ACROSS THE MOUNTAINS AND INTO THE FOOTHILLS FROM
MIDNIGHT TO NOON SUNDAY. THE GFS IS SIMILAR BUT WITH A 3-4 INCH
BULLEYE CENTERED ON SNOWSHOE WV. WITH THE UPPER LEVEL LOW COMING
OVER DURING THE MORNING...CHANCES ARE GOOD FOR SNOWFALL ESPECIALLY
ACROSS THE WEST. IF THE UPPER LOW IS SLOW TO MOVE ACROSS THE
AREA...THEN WE CAN NOT RULE OUT A COMMON INCH OR TWO ACROSS THE
MOUNTAINS...SLIGHTLY HIGHER AMOUNTS ALONG HIGHER ELEVATIONS.
HOWEVER...MODELS ZIP THE UPPER LOW ACROSS THE FORECAST AREA...WITH A
NARROW BAND OF MOISTURE BEHIND IT...TO KEEP TOTALS UNDER AN INCH.
THERE IS A WIDE RANGE IN GUIDANCE TEMPERATURES FOR SATURDAY. FOR
EXAMPLE...GFSMOS FOR ROANOKE IS 66F WHILE THE NAM IS FORECASTING
50F. THE ECMMOS IS 61F. WITH RAIN EXPECTED FOR MUCH OF THE
DAY...KEPT TEMPERATURES COOL...OBVIOUSLY BETWEEN GUIDANCE...SIMILAR
TO PREVIOUS FORECAST. WITH AN EARLY EXIT OF THE CLOSED
LOW...TEMPERATURES WILL REBOUND QUICKLY SUNDAY AFTERNOON. GUIDANCE
WAS A LITTLE MORE HELPFUL WILL FORECASTED HIGHS AROUND 5F COLDER
THAN NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EST THURSDAY...
LOOKS LIKE MARCH WILL GO OUT LIKE A LAMB AS THE FIRST HALF OF NEXT
WEEK LOOKS DRY. 1024 MB SURFACE HIGH IS PROGGED TO PASS OVHD
MONDAY...FOLLOWED BY A DRY FRONTAL PASSAGE TUESDAY. ASIDE FOR SOME
SCATTERED CLOUDS AND A WIND SHIFT TUESDAY...NO SENSIBLE WEATHER
CHALLENGES ANTICIPATED FOR MONDAY THROUGH WEDNESDAY.
THAT SAID...NOT QUITE AS PRISTINE FROM THE ROCKIES INTO THE UPPER
MID WEST WHERE THE STORM TRACK WILL NOT BE AS FORGIVING. THIS MID
CONUS STORMINESS WILL EVENTUALLY WORK ITS WAY TOWARD THE EAST COAST
BY THE END OF THE WEEK WITH THE BAROCLINIC ZONE SLIDING BACK OUR WAY
WITH THE THREAT FOR UNSETTLED WEATHER FROM THURSDAY INTO NEXT
WEEKEND.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 740 AM EDT FRIDAY...
SCATTERED SHOWERS WILL AFFEC THE AREA THIS MORNING...BECOMING MORE
NUMEROUS IN THE MOUNTAINS...PERHAPS ARRIVING AT LYH BY MIDDAY.
CIGS WILL FLUCTUATE BETWEEN LOW END VFR TO HIGH END MVFR THIS
MORNING THRU THE AFTERNOON. STILL SOME WINDS JUST ABOVE THE
INVERSION OUT OF THE SW GUSTING TO 40 KNOTS...SO KEPT LLWS IN
EARLY BEFORE SHOWERS.
THERE SHOULD BE A BREAK IN THE COVERAGE THIS AFTERNOON...WITH
ACTIVITY PICKING UP AGAIN TONIGHT IN THE SOUTH SPREADING NWD
OVERNIGHT. OVERALL SHOULD SEE SOME GUSTY WINDS MIX DOWN IN THE
ROA/LYH/DAN AREA THIS AFTERNOON WITH WINDS WEAKENING THIS EVENING.
MODELS ARE LOWERING CIGS/VSBYS TO MVFR OR IFR OVERNIGHT WITH RAIN
MOVING BACK IN.
THE LOW MOVES ACROSS SATURDAY WITH MOST SITES REMAIN SUB VFR WITH
RAIN SHOWERS. AN ISOLATED THUNDERSTORM WILL BE POSSIBLE OVER
LYH/DAN SAT AFTERNOON. WINDS PICK UP BEHIND THE LOW SAT NIGHT-
SUNDAY MORNING...BEFORE HIGH PRESSURE WORKS IN FOR MONDAY. LOOK
FOR IMPROVING CIGS/VSBYS SAT NIGHT IN THE EAST AND BY SUNDAY
AFTERNOON IN THE WEST.
DRY WEATHER AND VFR CONDITIONS ARE EXPECTED MONDAY THROUGH
TUESDAY.
&&
.EQUIPMENT...
AS OF 135 AM EDT THURSDAY...
ACCESS TO DATA ON OUR WEB PAGE...WWW.ERH.NOAA.GOV/RNK/...REMAINS
LIMITED DUE TO REGIONAL SERVER ISSUES. THERE IS NO ESTIMATE AT
THIS TIME FOR WHEN IT WILL BE REPAIRED.
OUR NEW...BUT UNFINISHED SITE...WWW.WEATHER.GOV/RNK/ IS OPERATING
PROPERLY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...RCS
LONG TERM...PM
AVIATION...DS/JC/WP
EQUIPMENT...AMS/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
646 AM CDT FRI MAR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CDT FRI MAR 28 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE U.S. WEST COAST INTO BRITISH COLUMBIA...A
PACIFIC SHORTWAVE OVER WYOMING...A VIGOROUS PACIFIC SHORTWAVE NEAR
DAVENPORT IA...AND A POLAR SHORTWAVE OVER LAKE WINNIPEG. THE
DAVENPORT IA SHORTWAVE...IN COMBINATION WITH PRECIPITABLE WATER
VALUES OF 0.6-0.9 INCHES / 200 PERCENT OF NORMAL / AND FRONTOGENESIS
HELPED PRODUCE PRECIPITATION ACROSS MUCH OF THE FORECAST AREA
YESTERDAY TO AROUND MIDNIGHT. MUCH OF THIS PRECIPITATION FELL AS
RAIN...WHICH WITH FROZEN GROUND HAS LED TO PLENTY OF RUNOFF AND
RISES ON AREA RIVERS AND STREAMS. SEE THE HYDROLOGY SECTION FOR MORE
INFORMATION. SOME OF THE PRECIPITATION FELL AS SNOW...MAINLY IN
NORTHWEST TO NORTH SECTIONS OF THE AREA...WITH THE MOST IN TAYLOR
COUNTY. LOW LEVEL CYCLONIC FLOW AROUND LOW PRESSURE OVER CENTRAL
LAKE MICHIGAN HAS KEPT CLOUDS IN PLACE THROUGH THE NIGHT...THOUGH
CLEARING WAS EVIDENT OVER THE NORTHWEST HALF OF MINNESOTA.
PRECIPITABLE WATER AT BIS WAS QUITE LOW WITH THE RIDGE...0.17 INCHES
AT BIS AND ABR OR 50-60 PERCENT OF NORMAL. COLDER AIR WAS ALSO
FILTERING IN...REFLECTING A CANADIAN RIDGE OF HIGH PRESSURE BUILDING
SOUTH INTO THE UPPER MIDWEST. FARTHER TO THE WEST...CLOUDS AND SOME
SCATTERED LIGHT PRECIPITATION WAS OCCURRING OVER WYOMING WITH THE
SHORTWAVE THERE.
AFTER AN ACTIVE PERIOD OF PRECIPITATION THE PAST 24 HOURS...THIS
SHORT TERM PERIOD LOOKS MUCH QUIETER. FOCUS FOR ANY POTENTIAL
PRECIPITATION WOULD BE ON THE SHORTWAVE OVER WYOMING...WHICH IS
PROGGED BY MODELS TO CROSS THE FORECAST AREA TONIGHT. HOWEVER...
THERE ARE 2 ITEMS GOING AGAINST PRECIPITATION... 1. ANOTHER
SHORTWAVE COMING OUT OF ARIZONA IS SUGGESTED TO INTENSIFY AND DEEPEN
AS IT REACHES MISSOURI TONIGHT...ROBBING THE WYOMING SHORTWAVE OF
MOISTURE. 2. THE WYOMING SHORTWAVE WILL BE HEADING INTO A DRY
AIRMASS AS SEEN ON THE BIS/ABR SOUNDINGS. MODELS CONTINUE TO DEPICT
THAT ANY PRECIPITATION WITH THE SHORTWAVE WILL DRY UP BEFORE THE
SHORTWAVE GETS TO THE FORECAST AREA...THUS STAYED WITH A DRY
FORECAST.
CLOUDS AND TEMPERATURES NOW BECOME THE MAIN CONCERNS. LOW CLOUDS
LOOK TO QUICKLY EXIT OFF TO THE EAST THIS MORNING AS THE DRIER AIR
TO OUR NORTHWEST ADVECTS IN. SCT-BKN MID AND HIGH CLOUDS WILL THEN
TRAVERSE THE AREA THIS AFTERNOON THROUGH TONIGHT AS THE WYOMING
SHORTWAVE MOVES THROUGH. 925MB TEMPS ARE PROGGED BETWEEN -2 TO -6C
AT 18Z...THOUGH MORE SUN TODAY WILL HELP TO COUNTERACT SOME OF THE
COLDER AIR. IN FACT...OVER THE SNOW FREE AREAS...TEMPERATURES MAY
EVEN END UP A LITTLE WARMER THAN YESTERDAY. ALTHOUGH SURFACE WINDS
LOOK LIGHT TONIGHT...THE CLOUDS SHOULD HELP TO HOLD READINGS UP FROM
THE MID TEENS TO MID 20S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 311 AM CDT FRI MAR 28 2014
MUCH OF THE LONG TERM PERIOD FOCUSES ON AN IMPRESSIVE LONG WAVE
TROUGH SITTING OVER THE EASTERN PACIFIC. ALL MODELS SHOW THAT A
POTENT SHORTWAVE WILL COME OUT OF THIS TROUGH AND TRACK INTO THE
FORECAST AREA FOR MONDAY. THEN THE ENTIRE TROUGH LOOKS TO COME INTO
THE WESTERN U.S. ON TUESDAY...TRACKING INTO THE CENTRAL PLAINS ON
THURSDAY.
MUCH OF FRIDAY NIGHT THROUGH SUNDAY LOOKS TO BE DOMINATED BY
BUILDING RIDGING AHEAD OF THE POTENT SHORTWAVE MARCHING ACROSS THE
WESTERN U.S.. NO CONCERNS FOR PRECIPITATION DURING THIS PERIOD AS
THE FORECAST AREA TRANSITIONS FROM UNDER DOMINANCE OF HIGH PRESSURE
TO INTO THE WARM SECTOR OF A DEEPENING SURFACE CYCLONE OVER
NORTHEAST COLORADO. TEMPERATURES AND WINDS ARE THE MAIN ISSUES.
925MB TEMPS ARE PROGGED SLIGHTLY WARMER ON SATURDAY...0 TO -
4C...WHICH WITH WHAT LOOKS TO BE PLENTY OF SUN SHOULD HELP BOOST
TEMPS INTO THE 40S...PERHAPS EVEN AROUND 50 IN SOME VALLEY
LOCATIONS. SOUTH TO SOUTHWEST WINDS REALLY PICK UP SATURDAY
NIGHT...UPWARDS OF 40-50 KT BY 12Z SUN AT 925MB...CAUSING 925-850MB
TEMPS TO REALLY CLIMB. ANTICIPATING LOWS IN THE EVENING SATURDAY
NIGHT...THEN HOLD STEADY TO SLOWLY RISE AS THE WARM AIR SURGES IN.
THE CLIMB CONTINUES THROUGH SUNDAY AS THE 925MB TEMPS CLIMB TO AS
MUCH AS 10-13C BY 00Z MONDAY. 400-250MB RH PROGS SUGGESTS PLENTY OF
SCT-BKN CIRRUS...BUT THE SUN AND WARM 925MB TEMPS SHOULD HELP PROPEL
READINGS INTO THE FIRST 60S OF THE YEAR FOR MOST LOCATIONS. MORE
SNOWPACK OVER TAYLOR/CLARK WILL HOLD READINGS BACK THERE INTO THE
50S...THOUGH THIS SNOWPACK IS GOING TO MELT FAST GIVEN THE WARM AIR
AND BREEZY CONDITIONS...YIELDING HYDRO CONCERNS. SEE HYDROLOGY
SECTION.
ATTENTION THEN TURNS TO THE POTENT SHORTWAVE HEADING INTO THE
FORECAST AREA FOR MONDAY. BOTH THE GFS AND ECMWF HAVE REALLY SLOWED
AND DEEPENED THIS SHORTWAVE AND THE ASSOCIATED SURFACE LOW OVER THE
PAST 24-48 HOURS. THIS RESULTS IN THE FORECAST AREA STAYING IN THE
WARM SECTOR LONGER AND THUS WARMER CONDITIONS ARE FORECAST FOR
SUNDAY NIGHT AND MONDAY. THERE ARE A COUPLE OF PRECIPITATION IMPACTS
TOO. FIRST...THE DEFORMATION BAND ON THE NORTHWEST SIDE OF THE LOW
NOW ONLY LOOKS TO IMPACT THE NORTHWEST HALF OF THE AREA MONDAY
AFTERNOON AND NIGHT...THOUGH IT MAY STAY ENTIRELY NORTHWEST OF THE
FORECAST AREA. SECOND...A LEAD WAVE OF RAIN RESULTING FROM
ISENTROPIC LIFT IS LOOKING LIKELY TO PROGRESS ACROSS THE FORECAST
AREA LATE SUNDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THIRD...THE
SYSTEMS COLD FRONT AND STRONG DYNAMICS ARE PROGGED TO MOVE THROUGH
MONDAY AFTERNOON AND EVENING. THERE IS A CAP TO BE OVERCOME...BUT
WITH SUCH STRONG FORCING...CANNOT RULE OUT A BAND OF SHOWERS AND
STORMS FIRING ON THE FRONT. SHOULD STORMS FORM...WHICH IS A BIG
IF...THERE IS AMPLE SHEAR TO SUPPORT SEVERE. WE WILL NEED TO KEEP AN
EYE ON INSTABILITY VERSUS CAPPING FOR MONDAY AFTERNOON.
TUESDAY INTO TUESDAY NIGHT LOOK TO BE QUIET AND MUCH COLDER...THEN
WEATHER GETS ACTIVE AGAIN FOR WEDNESDAY INTO THURSDAY AS THE REST OF
THE UPPER TROUGH LIFTS TOWARDS THE REGION. THIS TIME AROUND...WE MAY
HAVE TO DEAL WITH A WINTRY MIX SIDE DUE TO WARM/MOIST ADVECTION
ALOFT AND A FLOW OF DRY AIR AND COLD ADVECTION AT THE SURFACE.
THEN...IF THE 28.00Z ECMWF IS CORRECT...WE WILL AT LEAST CHANGE OVER
TO ALL RAIN AND PERHAPS BRING MORE THUNDERSTORMS. NEEDLESS TO
SAY...PLENTY OF UNCERTAINTY OUT THIS FAR AND THUS STAYED WITH A
MODEL CONSENSUS FOR NOW. CERTAINLY ANOTHER ITEM TO WATCH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 646 AM CDT FRI MAR 28 2014
MVFR CONDITIONS THIS MORNING WILL GRADUALLY GIVE WAY TO VFR
CONDITIONS LATE THIS MORNING INTO THIS AFTERNOON AS SURFACE HIGH
PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. PLAN ON CEILINGS IN
THE 1200 TO 2000 FT RANGE THIS MORNING...SCATTERING OUT BY LATE
MORNING AND EARLY AFTERNOON. A STORM SYSTEM IS EXPECTED TO TRACK
ACROSS THE CENTRAL PLAINS THIS AFTERNOON INTO THE OVERNIGHT HOURS
SPREADING MID TO HIGH LEVEL CLOUDS ACROSS THE TAF SITES WITH CLOUD
BASES IN THE 10 KFT TO 20 KFT RANGE.
&&
.HYDROLOGY...
ISSUED AT 311 AM CDT FRI MAR 28 2014
AREA RIVERS AND STREAMS CONTINUE TO MOSTLY RISE EARLY THIS MORNING
FROM THE RECENT RAIN. RAINFALL AMOUNTS AS MUCH AS A LITTLE OVER 1
INCH WERE OBSERVED...HIGHEST OVER THE SOUTHEAST HALF OF THE
FORECAST AREA. WITH FROZEN GROUND...MUCH OF THIS RAIN HAS TURNED
INTO RUNOFF. SO FAR THE ONLY FLOOD WARNING ISSUED AND VERIFIED WAS
ONTARIO...WHILE MOST OTHER RIVERS AND STREAMS ARE STAYING BELOW
FLOOD STAGE. EXPECTING MOST SHORT RESPONDING SITES LIKE ONTARIO TO
BEGIN FALLING SOON...WHILE LONGER RESPONDING LOCATIONS WILL CLIMB
FOR THE NEXT DAY OR SO AS RUNOFF CONTINUES TO FILTER THROUGH. SEE
THE LATEST HYDROLOGY RELATED STATEMENTS FOR MORE DETAILS.
NEXT HYDROLOGY CONCERN COMES SUNDAY THROUGH MONDAY AS A STRONG
SURGE OF WARM AIR COMES INTO THE REGION ON BREEZY SOUTH WINDS. IN
ADDITION...RAIN APPEARS LIKELY ON MONDAY. WITH PLENTY OF SNOW
STILL PRESENT ALONG/NORTH OF HIGHWAY 10...CONCERN THAT THIS SNOW
COULD RAPIDLY MELT...RESULTING IN MORE RISES ON RIVERS SUCH AS THE
TREMPEALEAU AND BLACK. WILL ISSUE AN ESF TO COVER THE POTENTIAL
FOR FLOODING. SOMEWHAT COOLER AIR FLOWING IN FOR TUESDAY AND
WEDNESDAY WILL SLOW THE MELT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1123 AM PDT FRI MAR 28 2014
.SYNOPSIS...SHOWERS WILL CONTINUE ACROSS THE NORTH BAY TODAY WITH
PARTLY CLOUDY SKIES FROM THE BAY AREA SOUTHWARD. RAIN WILL SLOWLY
INCREASE OVER THE NORTH BAY OVERNIGHT AND THEN SPREAD SOUTHWARD
THROUGH THE BAY AREA DURING THE DAY SATURDAY...REACHING THE
CENTRAL COAST BY SATURDAY AFTERNOON AND EVENING. DRY WEATHER
RETURNS SUNDAY AND THEN A STRONG COLD FRONT WILL ARRIVE MONDAY
WITH RAIN AND GUSTY WINDS. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ON TUESDAY...DRYING WEDNESDAY AND THEN MORE RAIN POSSIBLE
BY NEXT THURSDAY AND FRIDAY.
&&
.DISCUSSION...AS OF 9:13 AM PDT FRIDAY...SHOWERS CONTINUE ACROSS
THE NORTH BAY AT THIS HOUR WITH NONE OF THE MODELS CAPTURING THE
ACTIVITY...NOT EVEN THE HRRR AND RAP MODELS. FOR THE MOST PART
SHOWERS ARE LIGHT AND CONFINED TO THE HILLS AND COAST BUT MT ST
HELENA...MT TAMALPAIS AND WOODACRE HAVE ALL RECEIVED OVER THREE
TENTHS OF AN INCH IN THE LAST 12 HOURS. ANYWAY...WILL KEEP LIGHT
SHOWERS GOING THROUGH THE DAY IN THE NORTH BAY WITH DRY WEATHER
FROM SAN FRANCISCO SOUTHWARD.
WARM FRONTAL BOUNDARY WILL BECOME MORE ORGANIZED BY THIS EVENING
IN THE VICINITY OF CAPE MENDOCINO WITH SHOWERS BECOMING STEADY
RAIN OVER THE NORTH BAY TONIGHT. LIGHT SOUTH/SOUTHWEST FLOW WILL
CREATE FAVORABLE UPSLOPE AS THE FRONT DRIFTS SOUTHWARD INTO THE
BAY AREA BY SUNRISE SATURDAY MORNING. FOR THE MOST PART IT LOOKS
LIKE A GENTLE...SOAKING RAIN WITH FAIRLY LIGHT WINDS. LATEST QPF
SHOWS 1-2 INCHES FOR THE WETTEST COASTAL HILLS WITH 0.25-0.75 FOR
THE VALLEYS...DRIER OF COURSE IN THE USUAL RAIN SHADOWED INLAND
VALLEYS. LATEST NAM MODEL SHOWS THINGS DRYING OUT IN THE NORTH BAY
BY SATURDAY AFTERNOON WHILE RAIN CONTINUES FOR MUCH OF THE DAY
THROUGHOUT THE BAY AREA WITH THE HEAVIEST RAINS REACHING THE
MONTEREY BAY REGION BY THE LATE AFTERNOON AND EARLY EVENING HOURS.
THE FRONT WILL BE FAIRLY SLOW MOVING AS IT PASSES THROUGH OUR CWA
BUT THEN QUICKLY EXIT THE REGION SATURDAY NIGHT LEAVING DRY
WEATHER IN ITS WAKE FOR SUNDAY.
ATTENTION WILL THEN TURN TO POTENTIALLY STRONGER SYSTEM THAT WILL
ARRIVE MONDAY. LATEST TIMING BRINGS RAIN INTO THE NORTH BAY BEFORE
NOON ON MONDAY AND THEN STEADY RAINS PASSING THROUGH THE BAY AREA
FOR THE MONDAY AFTERNOON COMMUTE. RAINS ASSOCIATED WITH THE
FRONTAL PASSAGE SHOULD BRIEFLY BE HEAVY WITH STRONG AND WELL
DEFINED COLD FRONTAL BOUNDARY. STEADY RAIN WILL TURN TO SHOWERS BY
MONDAY EVENING. HOWEVER THE CORE OF THE UPPER LOW WILL KEEP
NUMEROUS SHOWERS AND MAYBE EVEN THUNDERSTORMS GOING FOR MUCH OF
TUESDAY WITH FAVORABLE NORTHWESTERLY POST-FRONTAL SET-UP. EARLY
QPF ESTIMATES WITH MONDAY/TUESDAY SYSTEM SUGGESTS 0.50-1.00 FOR
THE VALLEYS AND 2 INCHES FOR THE HILLS.
A BREAK IN THE WEATHER ON WEDS WITH MORE RAIN CHANCES BY NEXT
THURSDAY AND FRIDAY. WILL BE UPDATING THE GRIDS WITH THE LATEST
THINKING FOR THE AFTERNOON PACKAGES.
&&
.AVIATION...AS OF 11:05 AM PDT FRIDAY...DOPPLER RADAR SHOWS RAIN
SHOWERS CONTINUE TO MOVE ACROSS THE NORTH BAY THIS MORNING.
SHOWERS WILL TAPER THIS AFTERNOON BEFORE THE NEXT WAVE OF RAIN
HITS THE AREA SATURDAY. MID AND UPPER LEVEL CLOUDS WILL CONTINUE
TO STREAM IN ACROSS THE REGION AHEAD OF THE APPROACHING COLD FRONT
WITH WINDS EXPECTED TO VEER INCREASINGLY TO THE SOUTH AS THE DAY
PROGRESSES. RAIN IS ANTICIPATED TO BEGIN IN THE NORTH BAY AFTER
MIDNIGHT TONIGHT...SPREADING SOUTH ACROSS THE REGION THROUGH THE
MORNING. MODERATE CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR...GENERALLY LIGHT SOUTHERLY
WINDS ARE EXPECTED TO PREVAIL THOUGH MUCH OF THE FORECAST PERIOD.
WINDS WILL BECOME SOUTHWESTERLY BY EARLY AFTERNOON AS THE COLD
FRONT GETS CLOSER TO THE COAST. MODERATE CONFIDENCE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: RWW
AVIATION: CW
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
913 AM PDT FRI MAR 28 2014
.SYNOPSIS...SHOWERS WILL CONTINUE ACROSS THE NORTH BAY TODAY WITH
PARTLY CLOUDY SKIES FROM THE BAY AREA SOUTHWARD. RAIN WILL SLOWLY
INCREASE OVER THE NORTH BAY OVERNIGHT AND THEN SPREAD SOUTHWARD
THROUGH THE BAY AREA DURING THE DAY SATURDAY...REACHING THE
CENTRAL COAST BY SATURDAY AFTERNOON AND EVENING. DRY WEATHER
RETURNS SUNDAY AND THEN A STRONG COLD FRONT WILL ARRIVE MONDAY
WITH RAIN AND GUSTY WINDS. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ON TUESDAY...DRYING WEDNESDAY AND THEN MORE RAIN POSSIBLE
BY NEXT THURSDAY AND FRIDAY.
&&
.DISCUSSION...AS OF 9:13 AM PDT FRIDAY...SHOWERS CONTINUE ACROSS
THE NORTH BAY AT THIS HOUR WITH NONE OF THE MODELS CAPTURING THE
ACTIVITY...NOT EVEN THE HRRR AND RAP MODELS. FOR THE MOST PART
SHOWERS ARE LIGHT AND CONFINED TO THE HILLS AND COAST BUT MT ST
HELENA...MT TAMALPAIS AND WOODACRE HAVE ALL RECEIVED OVER THREE
TENTHS OF AN INCH IN THE LAST 12 HOURS. ANYWAY...WILL KEEP LIGHT
SHOWERS GOING THROUGH THE DAY IN THE NORTH BAY WITH DRY WEATHER
FROM SAN FRANCISCO SOUTHWARD.
WARM FRONTAL BOUNDARY WILL BECOME MORE ORGANIZED BY THIS EVENING
IN THE VICINITY OF CAPE MENDOCINO WITH SHOWERS BECOMING STEADY
RAIN OVER THE NORTH BAY TONIGHT. LIGHT SOUTH/SOUTHWEST FLOW WILL
CREATE FAVORABLE UPSLOPE AS THE FRONT DRIFTS SOUTHWARD INTO THE
BAY AREA BY SUNRISE SATURDAY MORNING. FOR THE MOST PART IT LOOKS
LIKE A GENTLE...SOAKING RAIN WITH FAIRLY LIGHT WINDS. LATEST QPF
SHOWS 1-2 INCHES FOR THE WETTEST COASTAL HILLS WITH 0.25-0.75 FOR
THE VALLEYS...DRIER OF COURSE IN THE USUAL RAIN SHADOWED INLAND
VALLEYS. LATEST NAM MODEL SHOWS THINGS DRYING OUT IN THE NORTH BAY
BY SATURDAY AFTERNOON WHILE RAIN CONTINUES FOR MUCH OF THE DAY
THROUGHOUT THE BAY AREA WITH THE HEAVIEST RAINS REACHING THE
MONTEREY BAY REGION BY THE LATE AFTERNOON AND EARLY EVENING HOURS.
THE FRONT WILL BE FAIRLY SLOW MOVING AS IT PASSES THROUGH OUR CWA
BUT THEN QUICKLY EXIT THE REGION SATURDAY NIGHT LEAVING DRY
WEATHER IN ITS WAKE FOR SUNDAY.
ATTENTION WILL THEN TURN TO POTENTIALLY STRONGER SYSTEM THAT WILL
ARRIVE MONDAY. LATEST TIMING BRINGS RAIN INTO THE NORTH BAY BEFORE
NOON ON MONDAY AND THEN STEADY RAINS PASSING THROUGH THE BAY AREA
FOR THE MONDAY AFTERNOON COMMUTE. RAINS ASSOCIATED WITH THE
FRONTAL PASSAGE SHOULD BRIEFLY BE HEAVY WITH STRONG AND WELL
DEFINED COLD FRONTAL BOUNDARY. STEADY RAIN WILL TURN TO SHOWERS BY
MONDAY EVENING. HOWEVER THE CORE OF THE UPPER LOW WILL KEEP
NUMEROUS SHOWERS AND MAYBE EVEN THUNDERSTORMS GOING FOR MUCH OF
TUESDAY WITH FAVORABLE NORTHWESTERLY POST-FRONTAL SET-UP. EARLY
QPF ESTIMATES WITH MONDAY/TUESDAY SYSTEM SUGGESTS 0.50-1.00 FOR
THE VALLEYS AND 2 INCHES FOR THE HILLS.
A BREAK IN THE WEATHER ON WEDS WITH MORE RAIN CHANCES BY NEXT
THURSDAY AND FRIDAY. WILL BE UPDATING THE GRIDS WITH THE LATEST
THINKING FOR THE AFTERNOON PACKAGES.
&&
.AVIATION...AS OF 4:40 AM PDT FRIDAY...A MIX OF SUN AND CLOUDS
WILL PASS OVER THE TERMINALS TODAY WITH A STRAY SHOWER POSSIBLE AS
A COLD FRONT APPROACHES THE CENTRAL CALIFORNIA COAST. SHOWERS ARE
EXPECTED IN THE SANTA ROSA AREA TODAY WITH RAIN HITTING THE SAN
FRANCISCO BAY AREA AFTER MIDNIGHT.
VICINITY OF KSFO...VFR...GENERALLY LIGHT SOUTHERLY WINDS ARE
EXPECTED TO PREVAIL THIS MORNING. WINDS WILL BECOME SOUTHWEST BY
EARLY AFTERNOON AS THE COLD FRONT GETS CLOSER TO THE COAST. A
PASSING SHOWER WILL BE POSSIBLE THIS MORNING WITH LIGHT RAIN
EXPECTED TO BEGIN AFTER MIDNIGHT. MODERATE CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR...GENERALLY LIGHT SOUTHERLY WINDS
ARE EXPECTED TO PREVAIL THIS MORNING. WINDS WILL BECOME SOUTHWESTERLY
BY EARLY AFTERNOON AS THE COLD FRONT GETS CLOSER TO THE COAST.
MODERATE CONFIDENCE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: RWW
AVIATION: LARRY
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AREA FORECAST DISCUSSION
NWS EUREKA CA
906 AM PDT FRI MAR 28 2014
.SYNOPSIS...RAIN WILL CONTINUE TO SPREAD SOUTH TODAY AS AN
ATMOSPHERIC RIVER SLOWLY MOVES SOUTH OVER THE AREA. RAIN WILL
TAPER TO SHOWERS LATE TONIGHT AND BRING A SLIGHT CHANCE OF A
THUNDERSTORM AND SMALL HAIL ON SUNDAY.
&&
.UPDATE...RAIN HAS SPREAD SOUTH A BIT SLOWER THAN EXPECTED
TODAY...AT LEAST IN THE LOW ELEVATIONS. MODERATE TO THE HIGHER
ELEVATIONS HAVE BEEN GETTING SIGNIFICANT RAINFALL AS EXPECTED.
COOSKIE MOUNTAIN NEAR CAPE MENDOCINO HAS GOTTEN 1.40 INCHES AS OF
8 AM. RAIN IS STILL EXPECTED IN THE EUREKA AREA...BUT IT WILL
START A BIT LATER AND AMOUNTS WILL BE A LOWER THAN PREVIOUSLY
EXPECTED. MKK
&&
.PREV DISCUSSION......ISSUED AT 400 AM PDT...
SHORT TERM (TODAY THROUGH TUESDAY)...MADE SLIGHT ADJUSTMENTS TO THE
EARLY MORNING FORECAST TO SLOW THE SOUTHERN PROGRESSION OF THE FRONT
BY A COUPLE HOURS. THE ONLY NOTICEABLE CHANGE WILL BE FOR SOUTHERN
MENDOCINO COUNTY THIS MORNING. OTHERWISE LEFT THE FORECAST NEARLY
THE SAME FOR TODAYS RAIN. THE MAIN FORECAST MODELS, THE GFS AND NAM,
CONTINUE TO SHOW THE ONSET OF STEADY RAIN BETWEEN 12Z AND 18Z.
HOWEVER, THE SHORT TERM RUC HOLDS OFF THE ONSET UNTIL ABOUT 18Z TO
19Z. REGARDLESS, PERIODS OF LIGHT RAIN ARE EXPECTED AHEAD OF THE
FULL ONSET OF THE ATMOSPHERIC RIVER RAINS, SO HAVE LEFT THE 100 POPS
FOR THE EARLY MORNING HOURS. LOOKING AT THE GEFS IVT MEAN VS THE OP
GFS IVT FROM THE 12Z RUN YESTERDAY AND THERE APPEARS TO BE A BIT OF
WIGGLE ROOM IN THE EXACT LANDING OF THE AR HEAD. THE GEFS MEAN TAKES
THE BULK OF THE IVT INTO SRN ORE WHILE THE OP GFS BRINGS IT INTO FAR
NORTHERN CAL. CAN NOT FIND ENOUGH EVIDENCE TO LOWER QPF AMOUNTS, BUT
AS THE DAY GOES ON WE MAY NEED TO ADJUST THE QPF DOWNWARD SLIGHTLY.
THIS WILL DEPEND ON WHERE THE HEAD OF THE AR HITS. SNOW LEVELS
WILL REMAIN AROUND 6KFT TODAY WITH ONLY THE HIGHEST PEAKS
RECEIVING ANY SNOW.
THE COLD FRONT STEERING TODAYS AR WILL SLOWLY SINK TO THE SOUTH
THROUGH THE DAY AND OVERNIGHT. AN UNSTABLE COOL AIR MASS WITH
LOWERING HEIGHTS WILL FILL IN BEHIND THE FRONT. A POST FRONTAL
TROUGH WILL BRING INSTABILITY ASSOCIATED WITH A VORT MAX TO THE
REGION ON SATURDAY AS THE TROUGH APPROACHES. MODELS ARE SHOWING
INCREASING CAPE AND LOWERING LI`S WITH THIS VORT MAX. WITH FAIRLY
WARM AIR IN PLACE AT THE SURFACE AND COOLING AIR ALOFT, THE
INGREDIENTS SHOULD BE PRESENT FOR WIDESPREAD CONVECTIVE SHOWERS
ACROSS NWCA. THERE IS A SLIGHT CHANCE SOME OF THESE SHOWERS WILL BE
THUNDERSTORMS, PRODUCING SMALL HAIL AND LOCALLY GUSTY WINDS. THE NAM
IS SHOWING A THIN CAPE PROFILE FOR MUCH OF THE AREA ON SAT WITH
VALUES IN THE FEW HUNDRED J/KG. THE TOP OF THE CONVECTION COULD
REACH AS HIGH AS 22KFT WITH A TEMP OF -37C. THIS SHOULD PROVIDE
ENOUGH DEPTH TO PRODUCE SMALL HAIL. FOR THE FORECAST, WENT AHEAD AND
MATCHED THE NEIGHBORS AND EXPANDED THE SLIGHT CHANCE OF TSTMS ACROSS
THE ENTIRE CWA. SPC CONTINUES TO SHOW NWCA IN THE THUNDERLINE FOR
SAT.
SUNDAY BROUGHT SOME SIGNIFICANT CHANGES TO THE ONGOING FORECAST.
WENT AHEAD AND BIT OFF ON THE IDEA OF A DRY DAY. SO PULLED BACK POPS
TO SLIGHT CHANCE OR LESS. MONDAY HOWEVER I WENT THE OTHER WAY.
MODELS HAVE BEEN CONSISTENT WITH A DIGGING UPPER LOW DIVING INTO
CALIFORNIA AND BRING ANOTHER QUICK SHOT OF RAIN. CONFIDENCE IS
INCREASING FOR RAIN ON MONDAY, SO WENT AHEAD AND UPPED THE POPS TO
100 FOR A SHORT TIME. THIS DIGGING LOW COULD PROVE TO VERY
INTERESTING WITH SHARP COOLING ALOFT, A NEG TILTED TROUGH AXIS, AND
A STRONG VORT MAX. THIS COULD BRING NWCA ANOTHER SHOT OF TSTMS AND
SMALL HAIL ON MONDAY. THE OTHER ISSUE TO WATCH ON MONDAY WILL BE
LOWERING SNOW LEVELS AND WIDESPREAD PRECIPITATION. THIS COULD
BRING A FEW INCHES OF SNOW TO AREA PASSES BY MONDAY EVENING. MORE
TO COME. TUESDAY WILL BRING THE BEGINNING OF A SHORT BREAK IN
WEATHER. BFG
LONG TERM (WEDNESDAY THRU FRIDAY)...WED WILL CONTINUE A SHORT BREAK
IN THE WEATHER. MODELS ARE INDICATING ANOTHER UPPER TROUGH DIVING IN
FOR THE SECOND HALF OF THE WEEK, BUT ARE HAVING ISSUES WITH TIMING
STRENGTH. WITH A WET PATTERN EXPECTED, KEPT WITH THE IDEA OF LIKELY
RAIN FOR THU THROUGH SAT. CONFIDENCE IS LOW TO MODERATE DUE TO
UNCERTAINTY IN TIMING AND STRENGTH. BFG
AVIATION...BREEZY SOUTHERLY WINDS WILL ACCOMPANY PERIODS OF
HEAVY RAIN TODAY. EXPECT MVFR WITH PERIODS OF LIFR DURING HEAVY
RAIN ACROSS THE REGION.
MARINE...SOUTHERLY WINDS WILL PERSIST ACROSS THE WATERS THROUGH THE
MIDDLE OF NEXT WEEK. A SERIES OF LONG PERIOD WESTERLY SWELLS WILL
PROPAGATE ACROSS THE WATERS THROUGH THE MIDDLE OF NEXT WEEK. THE
WINDS AND SEAS WILL INCREASE TODAY AS A COLD FRONT APPROACHES THE
AREA. THE SEAS WILL REMAIN ELEVATED THROUGH THE MIDDLE OF NEXT
WEEK. SMALL CRAFT ADVISORIES ARE IN EFFECT ACROSS THE WATERS
THROUGH EARLY NEXT WEEK.
HYDROLOGY...
AN ATMOSPHERIC RIVER ACCOMPANIED BY A SLOW MOVING COLD FRONT WILL
BRING COPIOUS AMOUNTS OF RAINFALL TO NORTHWEST CALIFORNIA TODAY
THROUGH SATURDAY MORNING. STEADY RAIN AND OCCASIONAL PERIODS OF
HEAVY RAIN CAN BE EXPECTED AS THE FRONT MOVES ACROSS THE REGION.
THE HIGHER RAINFALL VALUES WILL OCCUR IN DEL NORTE COUNTY AND
ALONG THE COASTAL MOUNTAIN RANGES.
THE RAINFALL WILL BEGIN OVER DEL NORTE COUNTY THIS MORNING AND
MOVE SOUTH ACROSS HUMBOLDT AND TRINITY COUNTIES THROUGHOUT
FRIDAY AFTERNOON AND INTO MENDOCINO COUNTY FRIDAY EVENING.
POTENTIAL IMPACTS:
THE MAIN STEM RIVERS WILL HAVE RAPID RISES...BUT NO FLOODING IS
EXPECTED. ALL THE RIVERS ARE FORECAST TO REMAIN BELOW MONITOR
STAGE.
THE TRIBUTARY STREAMS WILL ALSO RISE BUT ARE EXPECTED TO
REMAIN WITHIN THEIR BANKS.
THERE IS THE POSSIBILITY OF URBAN FLOODING DUE TO CLOGGED STORM
DRAINS. AREAS WITH POOR DRAINAGE AND OTHER LOW LYING AREAS CAN
EXPECT PONDING OF WATER.
AFTER THE FRONT PASSES SCATTERED SHOWERS ARE EXPECTED THROUGHOUT
THE DAY SATURDAY.
FORECAST PRECIPITATION AMOUNTS:
VALID 500 AM FRIDAY TO 500 AM SATURDAY
SMITH RIVER BASIN...........3 TO 4 INCHES
KLAMATH RIVER BASIN.........2 TO 3 INCHES
REDWOOD CREEK BASIN.........2.5 TO 3.5 INCHES
TRINITY RIVER BASIN.........2 TO 3 INCHES
MAD RIVER BASIN.............2 TO 3 INCHES
VAN DUZEN RIVER BASIN.......2.5 TO 3.5INCHES
SF EEL RIVER BASIN..........2.5 TO 3.5 INCHES
EEL RIVER BASIN.............2 TO 3 INCHES
VALID FROM 1100 AM FRIDAY TO 1100 AM SATURDAY
NAVARRO RIVER BASIN.........2 TO 3 INCHES
RUSSIAN RIVER BASIN.........1.5 TO 2.5 INCHES
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 9 AM PDT SUNDAY PZZ450-455-475.
SMALL CRAFT ADVISORY UNTIL 4 PM PDT MONDAY PZZ470.
&&
$$
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AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1024 AM MDT FRI MAR 28 2014
.UPDATE...
&&
.SHORT TERM...MIXING HAS COMMENCED...ALLOWING FOR GUSTY WESTERLY
WINDS TO SPREAD OFF THE FOOTHILLS ONTO THE ADJACENT PLAINS. SOME
GUSTS AROUND 45 MPH OCCURRING ACROSS PORTIONS OF THE AREA.
MOUNTAIN WEB CAMS STILL INDICATING SOME LIGHT SNOW ALONG THE
CONTINENTAL DIVIDE OF SUMMIT AND GRAND COUNTIES. THERE MAY ALSO BE
SOME LIGHT SNOW ACROSS THE PARK AND GORE RANGES OF WESTERN JACKSON
COUNTY. OVERALL THE SNOW IS SHOWING SOME SIGNS OF DECREASING AS
SLIGHTLY DRIER AND MORE SUBSIDENT AIRMASS SPREADS ACROSS THE
AREA. FLOW ALOFT HAS BECOME MORE NORTHWEST BEHIND THE RECENT UPPER
TROUGH. LATEST MODEL CROSS SECTIONS SHOW MOISTURE DEPTH DECREASING
THROUGH THE DAY...WOULD EXPECT TO SEE A CONTINUED DECREASE IN
MOUNTAIN SNOW...THOUGH IT MAY BE A GRADUAL DECREASE DUE TO
PERSISTENT OROGRAPHICS. ANY ADDITIONAL ACCUMULATIONS TO BE
LIGHT...THOUGH SOME FAVORED WEST FACING AREAS COULD SEE UP TO AN
INCH OF ADDITIONAL SNOWFALL. CURRENT FORECASTS SHOW THIS
TREND...SO ONLY MINOR CHANGES EXPECTED. CURRENT WESTERLY WINDS TO
SHIFT TO THE NORTHWEST BY 18Z AS MIXING CONTINUES AND SURFACE
GRADIENT BECOMES NORTHWEST. LATEST RAP INDICATING MAX GUSTS
AROUND 45 MPH STILL A POSSIBILITY THROUGH THE AFTERNOON...
ESPECIALLY IN AND NEAR THE FOOTHILLS AND ALONG THE WYOMING BORDER.
WILL MAKE SOME MINOR ADJUSTMENTS TO WIND GRIDS. WINDS STILL
EXPECTED TO DECREASE THIS EVENING WITH WEAKENING GRADIENT. LATEST
MODELS SHOWING SOME POTENTIAL FOR A FEW SHOWERS ACROSS THE FAR
NORTHEAST PLAINS THIS AFTERNOON AS A BATCH OF MID LEVEL MOISTURE
SPREADS INTO THE AREA WITH THE NORTHWEST FLOW ALOFT. LATEST RAP
GENERATES LIGHT QPF IN NORTHEAST WELD...WESTERN LOGAN AND NORTHERN
WASHINGTON COUNTIES BETWEEN 21Z AND 00Z. DON`T SEE ANYTHING ON
SATELLITE UPSTREAM AT THIS TIME TO INDICATE SHOWERS COULD DEVELOP.
WILL KEEP THINGS DRY FOR NOW BUT WILL CONTINUE TO MONITOR FOR ANY
DEVELOPMENT.
.AVIATION...WESTERLY WINDS FINALLY SPREADING ACROSS THE AREA...
WITH KBJC ALREADY SHIFTING TO THE WEST NORTHWEST. AS MIXING
CONTINUES...SHOULD SEE WINDS AT KDEN AND KAPA INCREASING BECOMING
WEST NORTHWEST BY 18Z IN LINE WITH LATEST RAP AND HRRR. CURRENT
TAFS SHOW THIS TREND AND WILL CONTINUE FOR THE UPCOMING ISSUANCE.
SOME GUSTS TO AROUND 30 KTS STILL POSSIBLE BY 21Z. WINDS EXPECTED
TO DECREASE THIS EVENING...TRANSITIONING TO A DRAINAGE FLOW. VFR
TO PREVAIL WITH CEILINGS ABOVE 12000 FEET AGL.
&&
.PREV DISCUSSION... /ISSUED 436 AM MDT FRI MAR 28 2014/
SHORT TERM...A BAND OF MODERATE TO HEAVY SNOW CONTINUES TO TRACK
EAST AND SOUTHEAST OVER THE PLAINS...AND WILL BE MOVING THROUGH
WASHINGTON AND NORTHEAST ELBERT COUNTIES THROUGH 5 AM. HAVE
ALREADY ADJUSTED FORECAST FOR THIS SNOWFALL THROUGH SUNRISE AND
HAVE EXTENDED SOME LOW POPS FOR EARLY THIS AM OUT OVER THE EASTERN
BORDER OF CWA. ALREADY CLEARING SKIES FURTHER WEST TOWARDS THE
FRONT RANGE AS SUBSIDENCE STARTING TO KICK IN AS UPPER LEVEL TROF
MOVES OVER THE STATE WITH MAIN CIRCULATION NOTED OVER NORTHEAST
WYOMING. DRYING NOTED IN WATER VAPOR IMAGERY OVER SOUTHERN
WYOMING AS GUSTY NORTHWEST WINDS ALREADY DEVELOPING OVER CYS AND
SOUTHERN PORTIONS OF SOUTHERN WYOMING. SHOULD SEE WINDS SPREADING
OVER THE FRONT RANGE FOOTHILLS FROM 10Z-15Z. STILL SOME
OROGRAPHIC INDUCED SNOW SHOWERS ONGOING OVER THE HIGHER MOUNTAINS
BUT SHOULD SEE A DIMINISH OF THE SHOWERS AS THE DAY WEARS ON AS
HIGH PRESSURE RIDGE BUILDS IN.
WINDS WILL BE INCREASING ON THE PLAINS THIS AFTERNOON AS LOW
LEVELS OF AIRMASS MIX OUT TO NEAR 500MB UNDER SUBSIDENT AIRMASS.
COULD SEE SOME GUSTS UP AROUND 30KT. WINDS WILL DIMINISH ON THE
PLAINS THIS EVENING AS AIRMASS DECOUPLES. WILL SEE A CONTINUATION
OF THE WINDS IN THE MOUNTAINS AND FOOTHILLS TONIGHT AS CROSS
SECTIONS SHOW CROSS BARRIER FLOW AROUND 30KT. TEMPERATURES WILL BE
SLIGHTLY COOLER TODAY BEHIND THE TROF BUT COOLING MITIGATED BY THE
STRONGER DOWNSLOPE FLOW.
LONG TERM...STRONG UNDULATING UPPER LEVEL ZONAL ZONE WILL REMAIN
OVER THE WESTERN HALF OF THE COUNTRY THROUGH THE FORESEEABLE
FUTURE ACCORDING THE LATEST MODEL OUTPUT. WE BEGIN WITH A
SHORTWAVE RIDGE WHICH MODELS PROPAGATE ACROSS THE CENTRAL ROCKY
MOUNTAIN REGION THIS WEEKEND. AMBIENT AIRMASS WARMS AND BECOMES
STRONGLY CAPPED AT MID-LEVEL ON SATURDAY AS THE FRONT SIDE OF
THIS RIDGE MOVES ACROSS THE FORECAST AREA. SATURDAY MAY NOT BE
THE WARMEST OF THE TWO DAYS...BUT PROBABLY THE SUNNIEST. MEANWHILE
WIDESPREAD PRESSURE FALLS ACROSS THE NORTHERN GREAT PLAINS ON
SATURDAY WILL HELP TO ENHANCE THE DOWNSLOPE GRADIENT FLOW ALONG
AND EAST OF THE COLORADO FRONT RANGE DURING THE DAY. BY MID-
AFTERNOON COULD SEE SOUTHWEST WINDS GUSTING TO AROUND 25KTS ALONG
THE PALMER DIVIDE FROM WESTERN ELBERT TO LINCOLN COUNTIES. IN
ADDITION...MIN RELATIVE HUMIDITY VALUES COULD FALL TO AS LOW AS 15
PCT WITH LATE DAY TEMPERATURES IN THE MID TO UPPER 60S. SHOULD
LATER MODEL RUNS INDICATE STRONGER WINDS AND/OR LOWER RH VALUES
FOR A PERIOD LONGER THAN A FEW HOURS...IT MAY BE NECESSARY TO
ISSUE A FIRE WEATHER WATCH FOR THIS AREA. AS IT STANDS NOW NO
WATCH. BY SUNDAY...FLOW ALOFT TRANSITIONS FROM WEST-NORTHWESTERLY
TO SOUTHWESTERLY WITH THE PASSAGE OF THE 500MB RIDGE AXIS SATURDAY
NIGHT. THIS OPENS THE DOOR TO AN INFLUX OF HIGH LEVEL MOISTURE
LEADING TO A GRADUAL INCREASE IN HIGH LEVEL CLOUD COVER THROUGH
THE DAY. IN ADDITION...FLOW ALOFT IS FORECAST TO STRENGTHEN
THROUGH THE DAY WITH 45-60KT 700-500MB WINDS BY AFTERNOON. ON THE
PLAINS...PRESSURE FALLS AROUND A SFC LOW FORMING IN THE NEBRASKA
PANHANDLE WILL FURTHER ENHANCE TO SOUTH-SOUTHWEST WINDS ALREADY
ON THE PLAINS. BY AFTERNOON COULD SEE GUSTS IN THE 30-40KT RANGE
ALONG THE PALMER DIVIDE OUT TO THE KANSAS LINE. MAX TEMPERATURES
IN THE MID 60S TO LOWER 70S...RH VALUES POSSIBLY IN THE 8 TO 15
PCT RANGE AND THE GUSTY WINDS MENTIONED ABOVE WILL FURTHER
ENHANCE THE WILDLAND FIRE DANGER IN THIS AREA. NO FIREWEATHER
WATCH YET...HOWEVER ONE MAY BE ISSUED WITHIN THE NEXT 24 HOURS
FOR SUNDAY AFTERNOON AND EVENING. THAT SAID...WILL INTRODUCE
AREAS OF BLOWING DUST TO THE SUNDAY FORECAST FOR THE SOUTHEAST
CORNER OF THE FORECAST AREA. AS NOTED ABOVE...IT APPEARS SUNDAY
WILL BE THE WARMER OF THE TWO WEEKEND DAYS BUT MAY NOT SEE AS MUCH
SUNSHINE...ESPLY IN THE MTNS AND ACROSS THE NORTHEAST CORNER OF
THE STATE NEAR THE DEVELOPING SFC LOW. BY AFTERNOON COULD SEE
SCATTERED INSTABILITY SHOWERS FORMING IN THE HIGH COUNTRY AND BY
EVENING ACROSS THE FAR NORTHEAST CORNER OF THE STATE. CAN/T RULE
OUT A FEW T-STORMS AS WELL.
ON MONDAY...THE UPPER RIDGE SHIFTS EAST ALLOWING THE NEXT IN A
SERIES OF LOW AMPLITUDE SHORTWAVE TROUGHS TO PASS OVER THE STATE.
MODELS ALSO SHOW A COLD FRONT EXTENDING FROM THE SFC LOW NEAR THE
NORTHEAST TIP OF COLORADO PUSHING SOUTH ACROSS NORTHEASTERLY
COLORADO DURING THE EARLY MORNING HOURS. COOLING ALOFT WILL COMBINE
WITH THE INFLUX OF COOLER SFC AIR FROM WYOMING TO LOWER
TEMPERATURES TO NEAR OR SLIGHTLY BELOW AVERAGE ON MONDAY. THE
TROUGH QUICKLY MOVES OUT BY AFTERNOON ACCORDING TO MODELS AND WITH
DRYING AND SUBSIDENCE IN ITS WAKE SHOULD SEE LITTLE IF ANY PRECIP
ON MONDAY. INSTEAD NORTHWEST WINDS OF 30-40KTS ON THE PLAINS AND
FOOTHILLS DURING THE MORNING HOURS.
FOR THE REST OF THE WEEK...A WEAK SHORTWAVE RIDGE QUICKLY PASSES BY
MONDAY NIGHT...FOLLOWED BY ANOTHER SOMEWHAT STRONGER SHORTWAVE
TROUGH. MODELS SHOW THIS TROUGH DEEPENING OVER THE GREAT BASIN ON
TUESDAY AND MIGRATING OVER COLORADO BY WEDNESDAY. ANOTHER COLD
FRONT IS FORECAST TO SLIDE SOUTH ACROSS THE AREA AS THE TROUGH
PASSES. SHOULD SEE PRECIP CHANCES INCREASING FIRST IN THE HIGH
COUNTRY ON TUESDAY AND SPREADING TO NEARLY ALL ALL OF THE FORECAST
AREA BY WEDNESDAY. COULD SEE HIGHS ON WEDNESDAY SEVERAL DEGS BELOW
AVERAGE FOR THE DATE. COULD SEE THIS TROUGH HANG AROUND UNTIL
THURSDAY MORNING IF THE MODELS ARE CORRECT. AFTER THAT...DRIER
AND WARMER CONDITIONS RETURN WITH A STRONG UPPER RIDGE BUILDING
IN FROM THE GREAT BASIN.
AVIATION...SNOW HAS ENDED AT TERMINALS AS VFR CONDITIONS HAVE
RETURNED. MID LEVEL CLOUD DECK WILL DIMINISH BY DAYBREAK. EXPECT
INCREASING WEST TO NORTHWEST WINDS 15Z-19Z AND COULD SEE SOME
GUSTS UP AROUND 30KT THIS AFTERNOON WITH GOOD LOW LEVEL MIXING.
WINDS WILL DECREASE THIS EVENING WITH A RETURN TO DRAINAGE FLOW
FROM THE SOUTH AND SOUTHWEST.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS TAUNTON MA
440 PM EDT FRI MAR 28 2014
.SYNOPSIS...
DRY WEATHER BRIEFLY RETURNS LATER TONIGHT INTO SATURDAY MORNING.
A COASTAL STORM DEVELOPS SOUTH OF NEW ENGLAND SATURDAY...BRINGING
A CHILLY...WINDSWEPT...SOAKING RAIN TO OUR REGION SATURDAY NIGHT
INTO SUNDAY. DRY WEATHER RETURNS AROUND TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
430 PM UPDATE...WINDS HAVE DIMINISHED A BIT ACROSS PORTIONS OF
SOUTHEAST MA. SOUTHWEST WINDS ARE FUNNELING UP BUZZARDS BAY AND
TAPPING INTO THE HIGHER WINDS ABOUT 3000 FEET AGL. EXPECTING
MIXING TO DIMINISH THIS EVENING...WHICH SHOULD DROP WIND GUSTS
BELOW ADVISORY CRITERION. WILL LEAVE THE WIND ADVISORY UP FOR THE
NEXT COUPLE OF HOURS.
LIGHT RAINFALL SPREADING EAST. 28/18Z HRRR IS THE MOST AGGRESSIVE
GENERATING MEASURABLE RAINFALL. RADAR TRENDS THOUGH INDICATE A
DRYING ACROSS MOST OF RI AND SOUTHEAST MA AS IT MOVES EAST.
THINKING PRIMARILY SPRINKLES FOR THOSE AREAS...BUT WILL NOT RULE
OUT THE POSSIBILITY OF A FEW LOCATIONS GETTING MEASURABLE
RAINFALL.
TEMPERATURES CONTINUE TO RISE ALONG THE IMMEDIATE EAST COAST...
THANKS TO THE PERSISTENT SOUTHWEST WINDS. NOW THAT THE CLOUDS HAVE
ARRIVED...WE SHOULD START THE SLOW FALL THROUGH THIS EVENING.
EXPECTING THE RAINFALL TO MOVE OFFSHORE BY MID EVENING...ALTHOUGH
A COLD FRONT WILL TAKE A LITTLE LONGER TO DO SO. ONCE THIS FRONT
MOVES OFFSHORE...EXPECTING AT LEAST PARTIAL CLEARING TO DEVELOP
FROM NORTH TO SOUTH.
IT WILL BE TOUGH FOR TEMPERATURES TO DROP MUCH TONIGHT...WITH A
DECENT SOUTHERLY WIND AND CLOUDS PERSISTING THROUGH THE EVENING.
THINKING IT WILL BE A CASE OF TEMPERATURES SLOWLY FALLING THIS
EVENING...THEN FALLING MUCH MORE QUICKLY AFTER MIDNIGHT WHERE THE
CLOUDS BREAK UP.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
DRY TO START ALONG WITH SOME PARTIAL SUNSHINE...ESPECIALLY ACROSS
NORTHERN MA INTO SOUTHWEST NH. A LOW PRESSURE DEVELOPS ALONG THIS
FRONT IN THE CENTRAL APPALACHIANS BY SATURDAY EVENING. HIGH
PRESSURE OVER QUEBEC...SHOULD KEEP THIS FRONT TO OUR SOUTH THROUGH
THE DAY. HOWEVER...THERE WILL BE PLENTY OF WARM CONVEYOR BELT
PROCESSES TO INCREASE CLOUDS AND RAINFALL CHANCES THROUGH THE
DAY.
TEMPERATURES SHOULD BE SIMILAR TO FRIDAY...MAINLY DUE TO THE
HIGHER STARTING POINT SATURDAY MORNING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* POTENT STORM SYSTEM WITH A GAMUT OF HEADLINES POSSIBLE SATURDAY
NIGHT INTO SUNDAY.
* DRY WEATHER FOR THE MIDDLE OF THE WEEK
* MORE ACTIVE PATTERN FOR THE END OF THE WEEK
MODELS AND CONFIDENCE...
MODERATE CONFIDENCE IN THE OVERALL FORECAST ESPECIALLY BECAUSE OF
THE SIGNIFICANT SPREAD LATE NEXT WEEK. HOWEVER DO HAVE HIGH
CONFIDENCE THAT HEAVY PRECIP WILL OCCUR LATE SAT INTO SUN ACROSS A
GOOD PORTION OF THE REGION. MODERATE CONFIDENCE THAT SOME OF THAT
PRECIP WILL BE IN A WINTRY MIX LATE SUNDAY INTO MONDAY. LOWER
CONFIDENCE ON THE FORECAST FOR NEXT WEEK HOWEVER IT APPEARS THAT
THERE MAY BE A DRY DAY OR TWO THANKS TO HIGH PRESSURE.
12Z GUIDANCE IS IN GOOD AGREEMENT WITHIN THE MEDIUM
RANGE...HOWEVER IN THE LONG RANGE IT APPEARS TO HAVE SIGNIFICANT
DIFFERENCES. A STALLED LOW WILL MOVE OVER THE REGION LATE SATURDAY
AND STALL UNTIL MONDAY. UPPER LEVEL RIDGE WILL DEVELOP BY
TUESDAY/WEDNESDAY BEFORE ANOTHER STRONG UPPER LEVEL LOW MOVES INTO
THE REGION BY THE END OF THE WEEK. OVERALL TRENDED THE FORECAST
OUTSIDE OF THE SYSTEM TOWARD THE ENSEMBLES. DETAILS ON THE STALLED
LOW ARE BELOW.
DETAILS...
SATURDAY NIGHT INTO MONDAY...
* MODELS/OVERVIEW...A FRONT WILL STALL OVER THE REGION COMBINED
WITH THE APPROACHING UPPER LEVEL LOW...WILL BE THE FOCUS FOR THE
WEATHER OVER THE WEEKEND. DETAILS ON THE MODEL GUIDANCE...FIRST
THREW OUT THE NAM AS IT IS TO PROGRESSIVE AND THEREFORE BRINGING
A COLD BIAS INTO THE REGION THE LATE SUNDAY INTO MONDAY TIME
PERIOD. TRENDED TOWARDS THE EC/GFS AS THE MORE AMPLIFIED TREND
SEEM REASONABLE. THE OVERALL AXIS OF HEAVIER PRECIP ON BOTH OF
THE GFS AND EC HAS SHIFTED SLIGHTLY EASTWARD COMPARED TO 00Z
GUIDANCE. THIS GOES ALONG WITH THE THINKING OF THE ENSEMBLES.
OVERALL TRENDED THE FORECAST TO A 2:1 GFS TO EC COMBO WITH THE
QPF GEARED MORE TOWARDS THE RFC.
* DETAILS...STACKED COASTAL LOW WILL MOVE CLOSER TO THE REGION
SATURDAY NIGHT INTO SUNDAY RESULTING IN THE DEVELOPMENT OF A
STRONG SOUTHERLY LLJ BEHIND THE WARM FRONT. EXPECT HEAVY RAIN TO
START AFTER 06Z SAT NIGHT AS A BOUNDARY LAYER CONVERGENCE REGION
SETS UP ACROSS THE 95 CORRIDOR WITH EXCELLENT MOISTURE TRANSPORT
FEEDING INTO IT. THE LLJ WILL STRENGTHEN THROUGH THE MORNING
HOURS ON SUNDAY RESULTING IN SHOWALTER VALUES REACHING ABOVE 0C
AND K INDEX VALUES ABOVE 30C. THIS COULD DEVELOP SOME ISOLATED
THUNDER DURING THE DAY ON SUNDAY WHICH WILL BE CONFIDED TO THE
LOCATIONS SOUTH OF THE MASS PIKE INCLUDING THE WATERS. THIS
COINCIDES WITH THE NOSE OF THE LLJ. INTERESTING NOTE IS THAT THE
BOUNDARY LAYER MOISTURE CONFERENCE JUST SITS OVER THE 95
CORRIDOR THROUGH 00Z MONDAY. THIS GIVES FORECASTER CONFIDENCE
THAT THE AXIS OF HEAVIER PRECIP WILL SIT JUST ALONG OR NW OF
THIS CONVERGENCE AREA. A DRY SLOW WILL TRY TO MAKE ITS WAY OVER
THE CAPE AND THE ISLANDS BY LATE SUNDAY AS THE SYSTEM DEEPENS
AND BEGINS TO DEVELOP A TROWAL FEATURE ON THE BACKSIDE. AS THE
LOW PRESSURE SYSTEM MOVES EASTWARD...THIS TROWAL FEATURE WILL
BECOME MORE PRONOUNCE AND WITH STRONG NORTHERLY WINDS ON THE
BACKSIDE OF THE SYSTEM EXPECT SOME WINTRY PRECIP. RIGHT NOW IT
APPEARS THAT THE MAIN P-TYPE WILL BE IN THE FORM OF A COLD RAIN
WITH SOME SLEET OF FREEZING RAIN MIXED IN AS TEMPERATURES AT
THE SURFACE WILL DROP FASTER THAN ALOFT. THIS MIXING WILL LAST
INTO MONDAY BEFORE THE SYSTEM PULLS OUT OF THE REGION ENTIRELY
BY MONDAY AFTERNOON.
* IMPACTS...HAVE INCREASING CONFIDENCE THAT HEAVY PRECIP WILL
OCCUR AND A MODERATE CONFIDENCE THAT OVER 2 INCHES WILL FALL
ACROSS SOUTHERN NEW ENGLAND BETWEEN SAT EVENING INTO SUNDAY
NIGHT. THEREFORE WE HAVE ISSUED A FLOOD WATCH FOR AREAS THAT
MAY SEE NOT ONLY A GOOD AMOUNT OF QPF BUT ALSO THE POTENTIAL FOR
RIVER RISE. THE 12Z GEFS HAVE A 60-70 PERCENT PROBABILITY OF
EXCEEDING 2 INCHES AND WITHIN A 24 HOUR PERIOD BOTH THE GFS AND
EC SHOW THE POSSIBILITY OF OVER 2 INCHES. TRENDED THE FORECAST
TOWARDS A COMBINATION OF THE GFS/EC AND RFC FOR QPF. AT MOST A
FEW OF THE MAIN STEM RIVERS MAY RISE INTO ACTION AND MAY TOUCH
FLOOD STAGE DEPENDING ON WHERE THE HEAVIEST QPF FALLS AS WELL AS
SNOW MELT AND ICE JAM POTENTIAL. IF WE ANTICIPATE 3 OR MORE THEN
WE MAY HAVE TO START LOOKING AT RIVER FLOODING POTENTIAL...MORE
DETAILS BELOW. AS MENTIONED ABOVE APPEARS THAT ELEVATED THUNDER
WILL OCCUR ON SUNDAY...DO NOT ANTICIPATE ANY STRONG OR SEVERE
WEATHER AT THIS TIME. BECAUSE OF THE STRONG LLJ WE COLD SEE WIND
ADV HEADLINES ACROSS THE CAPE AND THE ISLANDS BUT LEFT THE
POTENTIAL OUT FOR NOW AS CONFIDENCE IS LOWER. ON THE BACKSIDE OF
THIS SYSTEM...TEMPERATURES COULD DROP BELOW 32 AND WITH TEMPS
ALOFT BEING 2-3C ABOVE 0 THEN THERE IS THE POTENTIAL FOR ICE ESP
ACROSS THE NW PORTION OF THE FORECAST REGION. HOWEVER IF DYNAMIC
COOLING OCCURS AND THE SYSTEM CAN DRAW THAT COLD AIR ALOFT DOWN
TO THE LOW LEVELS THEN THERE MAY BE SLEET/SNOW ON THE BACKSIDE.
THIS ICE/SLEET POTENTIAL LINES UP WITH WPC GRAPHICS. THERE IS
ALSO THE POTENTIAL FOR MINOR COASTAL FLOODING ALONG BOTH THE
SOUTH COAST AND EAST COAST SHORELINES FOR MULTIPLE HIGH TIDE
CYCLES...MORE DETAILS BELOW.
TUESDAY AND WEDNESDAY....
WEAK RIDGING ALOFT WILL SET-UP ACROSS THE AREA ON TUESDAY AND
WEDNESDAY YIELDING TO HIGH PRESSURE AND HOPEFULLY DRY WEATHER.
TEMPERATURES WILL BE CLOSER TO SEASONABLE THANKS TO A THERMAL RIDGE.
THURSDAY AND BEYOND...
SEVERAL RIPPLES MOVING THROUGH THE LONG WAVE RIDGE WILL YIELD TO
CLOUDS AND SHOWERY WEATHER. TEMPERATURES WILL BE CLOSE TO
SEASONABLE.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERALL FORECAST CONFIDENCE IS MODERATE THROUGH SATURDAY. HAVE
HIGH CONFIDENCE IN TRENDS...BUT ONLY MODERATE CONFIDENCE IN
TIMING.
THROUGH 00Z...MAINLY VFR OUTSIDE OF SHOWERS...WITH MVFR IN
ANY SHOWERS. LOCAL IFR DEVELOPING ACROSS THE HIGHER TERRAIN OF
CENTRAL MA AND SOUTHWEST NH.
TONIGHT...FRONT SLIPS SOUTH OF NEW ENGLAND. MVFR/IFR IMPROVES TO
VFR...TAKING LONGEST ALONG THE SOUTH COAST. ANY LINGERING RAIN
SHOWERS ON THE SOUTH COAST MOVE OFFSHORE LATE THIS EVENING.
SATURDAY...VFR AND DRY TO START...THEN LOWERING TO MVFR AS RAIN
MOVES NORTH LATER IN THE AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SW WINDS MAY BRIEFLY GUST
UP TO 35 KT LATE THIS AFTERNOON.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
SATURDAY NIGHT THROUGH MONDAY...MODERATE CONFIDENCE. AREAS OF MVFR
CIGS/VSBYS IN HEAVY RAIN/FOG. A WINTRY MIX IS POSSIBLE LATE SUNDAY
NIGHT INTO MONDAY AS PRECIP COMES TO AN END.
TUESDAY INTO WEDNESDAY...MODERATE TO HIGH CONFIDENCE. IMPROVING
CONDITIONS AS RAIN MOVES OUT OF THE REGION...VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE TO HIGH FORECAST CONFIDENCE THRU SAT NIGHT.
TONIGHT...
A COLD FRONT MOVES OFFSHORE WITH WINDS DIMINISHING AND SHIFTING
FROM SW TO WNW BY SATURDAY MORNING. WILL NEED TO REPLACE GALE
WARNINGS WITH SMALL CRAFT ADVISORIES AS WINDS DIMINISH THIS
EVENING.
SATURDAY...
WARM FRONT LIFTS NORTH WITH INCREASING SOUTH WINDS ACROSS THE
SOUTHERN OUTER COASTAL WATERS. RAIN ALSO OVERSPREADS SOUTHERN
WATERS.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
SATURDAY NIGHT THROUGH MONDAY...LOW TO MODERATE CONFIDENCE. GALE
WARNINGS WILL LIKELY BE NEEDED FOR SOME OF THE COASTAL WATERS AS LOW
PRESSURE MOVES OVER THE WATERS. SEAS INCREASE TO 10 TO 15 FEET ON
THE OUTER WATERS. VISIBILITIES WILL LIKELY BE LIMITED AT TIMES IN
HEAVY RAIN AND FOG.
TUESDAY INTO WEDNESDAY...WINDS AND SEAS DIMINISH AS WEAK HIGH
PRESSURE BEGINS TO BUILD OVER THE WATERS.
&&
.HYDROLOGY...
MARCH PRECIPITATION HAS BEEN MOSTLY SPARSE ACROSS SOUTHERN NEW
ENGLAND...BUT WE MAY MAKE UP FOR THIS IN ABUNDANCE DURING THIS
WEEKEND. RIVERS AND STREAMS ARE RUNNING BELOW NORMAL FOR THIS TIME
OF YEAR...WHICH PROVIDES US A BUFFER. HOWEVER...THE POTENTIAL FOR 2
TO 4 INCHES OF RAINFALL WITH VEGETATION STILL DORMANT
...PLUS SNOWMELT IN THE FAR INTERIOR...IS SUFFICIENT TO BRING THE
CONCERN OF MINOR FLOODING ON AREA RIVERS AND STREAMS. THE MAIN AREA
OF CONCERN AT THIS TIME IS INTERIOR SOUTHERN NEW ENGLAND...AND THIS
IS WHERE FLOOD WATCHES ARE GOING INTO EFFECT. POOR DRAINAGE AREAS
...SMALL STREAMS...AND SOME LARGER TRIBUTARY RIVERS WILL BE AT RISK.
IN ADDITION...THE MORE VULNERABLE FORECAST LOCATIONS ON THE LOWER
MAINSTEM CONNECTICUT RIVER WILL NEED TO BE MONITORED OVER THE
COURSE OF THIS EVENT.
FOR RIVER FORECAST POINTS THAT ARE BEING MONITORED...GO TO
HTTP://WATER.WEATHER.GOV/AHPS2/FORECASTS.PHP?WFO=BOX . LOCATIONS OF
MAIN CONCERN ARE THOSE FORECAST TO GO TO ACTION STAGE OR HIGHER.
NOTE THAT THE FORECASTS GO OUT 72 HOURS...AND IN SOME INSTANCES THE
GAUGES ARE FORECAST TO BE CLIMBING THROUGH THE END OF THE
FORECAST PERIOD. AS MENTIONED...AT THIS TIME MINOR FLOODING IS
EXPECTED TO BE THE THREAT ON THE LARGER RIVERS.
WHILE REPORTS FROM OFFICIALS IN THE INTERIOR INDICATE RIVER ICE HAS
DECREASED IN COVERAGE AND THICKNESS OVER THE PAST TWO WEEKS...THERE
ARE STILL INDICATIONS THAT SOME RIVERS AND STREAMS IN SOUTHWEST NEW
HAMPSHIRE AND FAR NORTHWEST MASSACHUSETTS HAVE SUFFICIENT ICE TO
WARRANT A LOW RISK OF ICE JAMS AND ICE JAM RELATED FLOODING. WORDING
IN THE FLOOD WATCH IS BEING MENTIONED ACCORDINGLY.
&&
.TIDES/COASTAL FLOODING...
THE WEEKEND INTO EARLY NEXT WEEK SYSTEM POSES SOME RISK OF
COASTAL FLOODING AND BEACH EROSION SINCE THE ASTRONOMICAL HIGH
TIDES ARE RELATIVELY HIGH. THE SITUATION IS A BIT COMPLICATED WITH
BOTH SOUTH AND EAST COASTS AS WELL AS MULTIPLE HIGH TIDE CYCLES AT
RISK. AT THIS TIME THE IMPACT LOOKS TO BE MOSTLY MINOR BUT JUST A
FAIRLY MODEST STRENGTHENING OF THE COASTAL LOW AND ASSOCIATED LOW
LEVEL JET COULD RESULT IN A MODERATE IMPACT AT A FEW LOCATIONS.
SINCE THE EVENT IS STILL 2 TO 3 DAYS OUT...THE ONLY HEADLINE
ISSUED NOW IS A COASTAL FLOOD ADVISORY FOR PORTIONS OF THE RI AND
MA SOUTH COAST FOR THE SUN MORNING HIGH TIDE. ADDITIONAL HEADLINES
MAY BE NEEDED DURING THE COURSE OF THE WEEKEND.
SOUTH COAST...HAVE AT LEAST MODERATE CONFIDENCE OF MINOR COASTAL
FLOODING DURING THE SUNDAY MORNING HIGH TIDE IN PORTIONS OF
NARRAGANSETT BAY AND OTHER PORTIONS OF THE RI/MA COAST INCLUDING
WESTPORT. A VIGOROUS LOW LEVEL JET OF 50 TO 60 KT ON BOTH THE GFS
AND ECMWF IS EXPECTED TO INDUCE A 1 TO 1.8 FOOT SURGE...HIGHEST
UPPER PART OF NARRAGANSETT BAY...FOR THE SUN MORNING HIGH TIDE.
WAVES APPROACHING 10 FT JUST OFFSHORE MAY BE SUFFICIENT FOR SOME
SPLASHOVER AT THE TIME OF THE HIGH TIDE ALONG SOME SOUTH COAST
EXPOSED BEACHES SUCH AS THE NEWPORT AND WESTPORT SOUTH COAST
BEACHES AS WELL AS THE WEST ISLAND CAUSEWAY IN FAIRHAVEN. LESS
CONFIDENT ON ANY IMPACTS FOR THE SUN EVENING HIGH TIDE. ANTICIPATE
THE S OR SE FLOW TO HAVE DIMINISHED OR ENDED BUT WATER MAY BE
SLOW TO EVACUATE FROM A FEW LOCATIONS INCLUDING NARRAGANSETT BAY
WITH PRES FALLS BEING A POSSIBLE SECONDARY FACTOR.
EAST COAST OF MA...A N TO NNE FLOW BECOMES ESTABLISHED LATE SUN
THROUGH MON AND THEN BECOMING MORE NNW BY MON NIGHT. A LOW LEVEL
JET OF 40 TO 50 KT IMPACTS THE COASTLINE N OF BOS FOR THE SUN
NIGHT HIGH TIDE AND MOST OF THE MA E COAST FOR THE MON MIDDAY HIGH
TIDE. THERE IS SOME SUGGESTION...ESPECIALLY FROM THE ECMWF
MODEL...THAT THE LOW LEVEL JET MAY PERSIST TO IMPACT THE HIGH TIDE
AROUND 1 AM TUE FOR NANTUCKET HARBOR AND THE N SIDE OF CAPE COD.
ALTHOUGH AT THIS TIME THE IMPACTS LOOK TO BE MOSTLY
MINOR...MULTIPLE HIGH TIDE CYCLES ARE LIKELY TO BE INVOLVED AND
JUST A MODESTLY STRONGER SYSTEM AND ASSOCIATED NNE WINDS COULD
RESULT IN POCKETS OF MODERATE IMPACTS. GIVEN THAT MULTIPLE TIDE
CYCLES WILL LIKELY BE AFFECTED...AT LEAST SOME BEACH EROSION IS
LIKELY FROM SALISBURY TO CAPE ANN INCLUDING PLUM ISLAND...THE
PLYMOUTH COUNTY COAST...N AND OCEAN SIDES OF CAPE COD AND THE E
SIDE OF NANTUCKET BEFORE THIS EVENT IS OVER.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR
CTZ002>004.
MA...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ018>023.
COASTAL FLOOD ADVISORY FROM 6 AM TO 10 AM EDT SUNDAY FOR
MAZ020.
FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR
MAZ002>006-008>012-026.
NH...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY AFTERNOON FOR
NHZ011-012-015.
RI...COASTAL FLOOD ADVISORY FROM 6 AM TO 10 AM EDT SUNDAY FOR
RIZ002-004-005-007.
FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR
RIZ001.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR ANZ231>234.
GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR ANZ230-251.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR ANZ235-237-
254.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ255-256.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
HYDROLOGY...NMB
TIDES/COASTAL FLOODING...THOMPSON
AREA FORECAST DISCUSSION
NWS ALBANY NY
422 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION TONIGHT WITH
IMPROVING CONDITIONS DEVELOPING FROM WEST TO EAST. ANOTHER STORM
SYSTEM APPROACHES AND WILL BRING MODERATE TO HEAVY AMOUNTS OF
PRECIPITATION FOR MOST OF THIS WEEKEND. THE POTENTIAL FOR
FLOODING AND ICE JAMS INCREASES ALONG WITH WINTER WEATHER
CONCERNS ACROSS THE ADIRONDACKS. OUR WEATHER IS EXPECTED TO
IMPROVE INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
TEMPERATURES ACROSS CENTRAL AND WESTERN NEW YORK HAVE RISEN WELL
INTO THE 50S AS THIS REGION HAS BEEN PRECIPITATION FREE THE PAST
SEVERAL HOURS /EVEN SOME BREAKS IN THE CLOUD COVER SEEN IN THE 1KM
VISIBLE IMAGERY/. WE STILL HAVE A FEW MORE HOURS OF DAYLIGHT AS WE
STILL COULD ACHIEVE OUR MILDER TEMPERATURES AND WE WILL RETAIN THE
HOURLY GRIDS WITH SLIGHT MODIFICATIONS PER OBSERVATIONS.
COLD FRONT WAS JUST APPROACHING EXTREME WESTERN NY AS SHOWERS WERE
JUST DEVELOPING AT THE TIME OF WRITING THIS DISCUSSION. PER THE
LATEST HRRR REFLECTIVITY FORECASTS...SEEMS THESE SHOWERS WILL MOVE
ACROSS THE REGION THROUGH EARLY THIS EVENING. THE THERMAL CONTRAST
WITH FROPA IS NOT THAT NOTICEABLE AS LATEST MOS GUIDANCE CAPTURES
THIS IDEA AS WE WILL LEAN TOWARD A SLIGHTLY WARMER OVERNIGHT LOWS.
RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION
OVERNIGHT WITH GRADUALLY IMPROVING SKY CONDITIONS FROM WEST TO
EAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
...FLOOD WATCH IN EFFECT OUTSIDE OF THE ADIRONDACKS...
...WINTER STORM WATCH IN EFFECT FOR THE ADIRONDACKS...
H2O VAPOR LOOP REVEALS THE KEY PLAYERS WITH A COUPLE OF NOTABLE
UPPER LEVEL WAVES ACROSS THE PLAINS. MODEL DIAGNOSIS HAS COME INTO
A RATHER GOOD AGREEMENT OF PHASING EVOLVING ACROSS THE
OHIO/TENNESSEE VALLEY TRANSITIONING INTO AN CLOSED UPPER LOW OVER
THE MID ATLANTIC REGION. THERMAL PROFILES CONTINUE TO WARM IN THE
GLOBAL MODELS AS THE NAM REMAINS TOO COLD. COMBINATION OF MODERATE
TO HEAVY QPF...THERMAL PROFILES LINING UP ACROSS THE
ADIRONDACKS...WARMING THERMAL PROFILES FOR ICE BEGINNING TO MOVE
ALONG THE RIVERS/STREAMS COULD RESULT IN ICE JAMS. NOW ONTO THE DETAILS...
SATURDAY...
MOST OF THE DAY SHOULD BE RATHER TRANQUIL AS WE BEGIN THE DAY
RATHER DRY WITH PARTIAL SUNSHINE IN THE MORNING. CLOUDS WILL
EVENTUALLY INCREASE FROM SOUTH TO NORTH AS TEMPERATURES ACROSS
MOST OF THE REGION MODERATING INTO THE 40S WITH COOLER 30S ACROSS
THE ADIRONDACK REGION. THESE TEMPS WILL BE KEY TO THE PRECIP TYPE
EXPECTED SATURDAY NIGHT.
SATURDAY NIGHT...
CROSS SECTIONS AND BUFR PROFILES WITH RESPECT TO TEMPERATURES
REVEAL A RATHER SHARP CONTRAST ACROSS THE ADIRONDACK REGION. THE
LOW LEVEL AGEOSTROPHIC FLOW INCREASES FROM THE NORTH WHICH COULD
KEEP THE NEAR SURFACE TEMPERATURES NEAR OR JUST BELOW FREEZING.
THIS COULD RESULT IN A PERIOD OF SLEET OR FREEZING RAIN
ACCUMULATION ACROSS THIS REGION AND PER COLLABORATION FROM
SURROUNDING WFOS AND WPC WWD...WE WILL HOIST A WINTER STORM WATCH
FOR THIS REGION.
OUTSIDE OF THIS REGION...A MODERATE TO HEAVY RAINFALL EVENT SEEMS
TO BE UNFOLDING AS PWAT ANOMALIES OF 1-3 STANDARD DEVIATIONS ABOVE
NORMAL...ASSOCIATED LOW LEVEL SOUTHERLY WIND ANOMALIES AND
IMPRESSIVE 2D FGEN OVERHEAD TO BRING ABOUT A PERIOD OF VERY WET
WEATHER. PLEASE REFER TO THE HYDROLOGY DISCUSSION BELOW FOR
FURTHER DETAILS.
SUNDAY...
MID LEVEL DRY SLOT APPROACHES AND SHOULD DIMINISH THE PRECIP
INTENSITY ACROSS THE AREA. DEFORMATION AXIS PER THE GLOBAL MODELS
APPEARS TO LINE UP JUST WEST OF OUR SERVICE AREA /NEAR I81/ SO THE
PRECIP THROUGH THE DAY IS EXPECTED TO REMAIN LIGHT. WE WILL LOWER
POPS ACCORDINGLY AS COLDER AIR ATTEMPTS TO SEEP INTO THE DACKS
WHERE ADDITIONAL LIGHT ACCUMULATIONS ARE POSSIBLE.
SUNDAY NIGHT...
THE AFOREMENTIONED DEFORMATION AXIS IS EXPECTED TO MIGRATE ACROSS
THE REGION...MEANWHILE...LOW LEVEL COLD ADVECTION IS FORECAST TO
INCREASE. THIS WOULD SUGGEST ANOTHER PERIOD OF WET WEATHER
TRANSITIONING TOWARD WINTRY TYPE PRECIPITATION ISSUES DEVELOPING
ACROSS THE ENTIRE REGION. THE LATEST ECMWF IS SUGGESTING QUITE A
STRONG SIGNAL THAT LATER FORECAST SHIFTS CAN FINE TUNE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE LONG TERM STARTS WITH THE CUTOFF LOW STILL BRINGING RESIDUAL
CLOUDS AND SHOWERS...MAINLY FROM THE HUDSON VALLEY EASTWARD ON
MONDAY. THIS LOW IS FORECAST TO SLOWLY PULL AWAY FURTHER EAST THAT
DAY...WITH CONDITIONS SLOWLY IMPROVING. HOWEVER...SINCE ANY SUNSHINE
WOULD GENERALLY BE LIMITED TO LATER IN THE DAY...WE HAVE TRIMMED
HIGH TEMPERATURES BACK FOR THAT DAY...GENERALLY LOOKING AT 50-55
ALBANY SOUTHWARD...40S FURTHER NORTH WEST AND EVEN EAST OF ALBANY
(WHERE CLOUDS WILL LINGER THE LONGEST).
RIDGE OF HIGH PRESSURE FINALLY BUILDS IN MONDAY NIGHT INTO TUESDAY.
THE QUESTION IS WHETHER OR NOT CLOUDS COULD REFORM UNDERNEATH AN
INVERSION MONDAY NIGHT. FOR NOW...WE PLAYED IT CAUTIOUSLY OPTIMISTIC
AND WENT WITH PARTLY CLOUDY MONDAY NIGHT. IF WE WERE TO
CLEAR...THERE COULD BE SOME FOG ISSUES TO DEAL WITH ALONG WITH LOWER
TEMPERATURES THAN WE ARE CURRENTLY FORECASTING. FOR NOW...WE LEFT
FOG OUT OF THE FORECAST SINCE THIS IS STILL SEVERAL DAYS OUT.
WITH PARTIAL CLEARING....LOOK FOR LOWS TO SLIP BACK INTO THE LOWER
TO MID 30S FROM THE CAPITAL REGION SOUTHWARD...20S FURTHER NORTH AND
ACROSS MUCH OF ELEVATED TERRAIN.
TUESDAY...FINALLY...LOOKS LIKE THE DAY MOST OF US HAVE BEEN WAITING
FOR. IT WILL MARK THE BEGINNING OF APRIL AND WE WILL LEAVE THE CHILL
OF MARCH BEHIND. EVEN IF WE DO START THE DAY CLOUDY...THEY SHOULD
BREAK UP FAIRLY QUICKLY. H850 TEMPERATURES LOOK TO WARM BACK UP TO
ABOUT +5C. WITH A STRONG APRIL SUNSHINE AND FAIRLY GOOD
MIXING...TEMPERATURES LOOK TO CLIMB TO THE UPPER 40S TO LOWER 50S
ACROSS THE ADIRONDACKS AND SOUTHERN GREENS...MID TO UPPER 50S ACROSS
THE REMAINDER OF THE REGION...WITH PERHAPS A FEW SPOTS IN THE MID
HUDSON VALLEY...TOUCHING 60 DEGREES. THE WIND SHOULD BE LIGHT SO IT
WILL FEEL PLEASANT OUTDOORS TO MOST FOLKS AND FINALLY FEEL LIKE
SPRING.
A WEAK SYSTEM FROM SOUTHERN CANADA LOOK TO BRING A FEW RAIN OR SNOW
SHOWERS...MAINLY NORTH OF THE CAPITAL REGION TUESDAY NIGHT INTO
WEDNESDAY. THIS SYSTEM LOOKS MOISTURE STARVED AT THIS POINT...SO ANY
PRECIPITATION LOOKS LIGHT. THIS STORM WILL DRAG A COLD FRONT THROUGH
THE MOST OF THE REGION BY WEDNESDAY...COOLING TEMPERATURES DOWN A
LITTLE. A WEST TO NORTHWEST BREEZE WILL HOLD TEMPERATURES IN THE
LOWER 50S LOCALLY IN THE CAPITAL REGION ON WEDNESDAY...MAINLY 40S
NORTH. TO THE LEE OF THE CATSKILLS...INCLUDING THE MID HUDSON VALLEY
AND LITCHFIELD COUNTY...THANKS TO A DOWNSLOPING WIND AND ABUNDANT
SUNSHINE...TEMPERATURES WILL ONCE AGAIN BOUNCE INTO THE MID OR UPPER
50S. THE REST OF THE REGION WILL RANGE FROM MOSTLY CLOUDY
(MOUNTAINS) TO PARTLY SUNNY(MOHAWK VALLEY AND GREATER CAPITAL
REGION).
HIGH PRESSURE WILL ATTEMPT TO WEDGE INTO THE REGION FROM SOUTH
CENTRAL CANADA LATER WEDNESDAY INTO THURSDAY. AT THE SAME TIME
HOWEVER...ANOTHER CUTOFF LOW PRESSURE IS FORECAST TO GATHER STRENGTH
IN THE NATION/S MIDSECTION.
THE QUESTION IS WHETHER OR NOT HIGH PRESSURE WILL TAKE CONTROL AND
KEEP THE CUTOFF TO OUR SOUTHWEST FOR THE REMAINDER OF THE WEEK.
OR...WILL THE LOW PRESSURE SLOWLY WORK INTO OUR REGION? THE FORMER
SOLUTION IS OFFERED BY THE 12Z EUROPEAN MODEL WHILE THE LATTER
WETTER SOLUTION IS FORECASTED BY THE 12Z GFS.
FOR NOW...FOLLOWED MAINLY THE WEATHER PREDICTION CENTER`S TAKE ON
THINGS (WPC)...WHICH LEANED MORE WITH THE WETTER GFS. WE HAVE SLIGHT
CHANCES OF POPS IN FOR THURSDAY...INCREASING THEM TO CHANCE THURSDAY
NIGHT THROUGH FRIDAY.
HIGH TEMPERATURES ON THURSDAY AND FRIDAY WILL BE HIGHLY DEPENDENT ON
CLOUD COVER. SINCE WE ARE GOING WITH INCREASING CLOUDS ON
THURSDAY...AND CLOUDY WITH BETTER CHANCES FOR SHOWERS FRIDAY...WENT
WITH SEASONABLE TEMPERATURES THURSDAY (MID 40S NORTH TO MID 50S
SOUTH) AND COOLER TEMPERATURES FRIDAY (LOWER 40S NORTH TO LOWER 50S
SOUTH).
IT MIGHT BE COLD ENOUGH THURSDAY NIGHT FOR SOME MOUNTAIN SNOWS...BUT
MOST VALLEY AREAS SHOULD REMAIN ALL RAIN.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AS A COLD FRONT APPROACHES THE REGION...AN AREA OF RAIN THIS AFTERNOON
WILL TAPER OFF TO SHOWERS BY THIS EVENING. WITHIN THIS
RAINFALL...FLYING CONDITIONS WILL GENERALLY BE MVFR...BUT BRIEF
PERIODS OF IFR CIGS/VSBYS CANNOT BE RULED OUT FOR KGFL/KPSF/KALB
THROUGH THE EARLY EVENING HOURS. HAVE ACCOUNTED FOR THIS WITH A
TEMPO GROUP. SOUTHERLY SFC WINDS WILL BE AROUND 10 KTS...WITH A
FEW HIGHER GUSTS FOR KALB...AS AIR IS FUNNELED UP THE HUDSON
VALLEY.
THE THREAT FOR RAINFALL WILL END THIS EVENING WITH THE PASSAGE OF
THE COLD FRONT. FLYING CONDITIONS WILL STILL BE MVFR FOR A FEW
HOURS DUE TO LINGERING LOW LEVEL MOISTURE KEEPING CIGS AROUND 1-3
KFT. BY LATER TONIGHT...A DRIER W-NW FLOW AT 5-10 KTS WILL ALLOW
FOR VFR CONDITIONS TO RETURN WITH JUST SOME REMAINING SCT CLOUDS
AROUND.
LIGHT N-NE WINDS WILL BE IN PLACE FOR SATURDAY MORNING WITH NO
PRECIPITATION. HOWEVER...MID AND HIGH LEVEL CLOUDS WILL INCREASE
THROUGH THE MORNING HOURS FROM SOUTH TO NORTH AS A STORM ORGANIZES
OVER THE MID ATLANTIC REGION. SOME RAIN WILL SPREAD BACK INTO THE
REGION FROM SOUTH TO NORTH DURING THE AFTN HOURS...WITH MVFR
CONDITIONS /MAINLY DUE TO VSBYS/ EXPECTED.
OUTLOOK...
SATURDAY AFTN: HIGH OPERATIONAL IMPACT. LIKELY RA.
SATURDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE RA...SLEET.
SUNDAY: HIGH OPERATIONAL IMPACT. BREEZY. DEFINITE RA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF
SHRA...SHSN.
MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY NIGHT TO WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE EXPECTED THROUGH AT LEAST THE
NEXT SEVERAL DAYS. THE WET WEATHER OF TODAY AND THEN A STRONGER
COASTAL SYSTEM EXPECTED TO BRING MODERATE TO HEAVY AMOUNTS OF
PRECIPITATION TO THE REGION OVER THE WEEKEND. SOME OF THE
PRECIPITATION MAY FALL AS SNOW OR A WINTRY MIX...ESPECIALLY ACROSS
THE HIGHER TERRAIN.
&&
.HYDROLOGY...
THERE WILL BE AN INCREASING POTENTIAL FOR HYDROLOGIC
ISSUES...INCLUDING RIVER ICE BREAK UP AND POSSIBLE FLOODING...OVER
THE WEEKEND. FLOOD WATCH IS NOW IN EFFECT OUTSIDE OF THE
ADIRONDACK REGION.
RAINFALL AMOUNTS CLOSE TO ONE HALF OF AN INCH HAVE BEEN OBSERVED
WITH SOME SLIGHT INCREASE NOTICED ON RIVER GAGES.
HOWEVER...TEMPERATURES HAVE BEEN SLOW TO RISE WHICH HAS ASSISTED
WITH THE RAINFALL LIKELY BEING ABSORBED INTO THE SNOWPACK AND
LITTLE ICE MOVEMENT AT THIS TIME.
HOWEVER...A MORE SIGNIFICANT STORM SYSTEM WILL MOVE FROM THE MID
ATLANTIC COAST TOWARDS NEW ENGLAND FOR LATE SATURDAY INTO SUNDAY.
THIS SYSTEM HAS THE POTENTIAL TO BRING MODERATE TO HEAVY AMOUNTS
OF PRECIPITATION TO THE REGION...ESPECIALLY FOR AREAS FROM THE
CAPITAL REGION SOUTH AND EAST...WITH MODEL CONSENSUS SHOWING ONE
TO THREE INCHES OF RAINFALL ACROSS SOUTHEASTERN PARTS OF THE
REGION. WHILE MUCH OF THIS WILL BE IN THE FORM OF RAINFALL...THERE
IS THE POTENTIAL FOR THE PRECIP TO CHANGE TO A WINTRY MIX OR
SNOWFALL BEFORE ENDING...MAINLY FOR NORTHERN AND HIGH TERRAIN
AREAS.
CURRENT NERFC RIVER FORECASTS SHOW RISING LEVELS TO NEAR OR ABOVE
FLOOD STAGE. THERE IS THE POTENTIAL FOR SIGNIFICANT
RISES...ESPECIALLY ACROSS THE HOUSATONIC BASIN...AND SUBSEQUENT
RIVER ELEVATION FORECASTS MAY NEED TO BE INCREASED IF THE LATEST
TRENDS IN MODEL GUIDANCE ARE CORRECT. ALTHOUGH QPF AMOUNTS ARE
ARE NOW FORECAST TO RANGE BETWEEN 1 AND 3 INCHES...THE CHALLENGE
IS ICE BREAKING UP ON LARGER MAIN STEM RIVERS AS WELL...WHICH COULD
POTENTIALLY CAUSE ICE JAMS IN SOME LOCATIONS. WITH THE BULK OF THE
RAINFALL EXPECTED TO OCCUR SATURDAY NIGHT IN A RELATIVELY SHORT
PERIOD OF TIME...SOME MINOR URBAN...LOW LYING...AND SMALL STREAM
FLOODING COULD POTENTIALLY OCCUR AS WELL. THE MOST LIKELY AREAS TO
SEE ISSUES WOULD BE FROM THE MOHAWK BASIN SOUTH AND EAST.
DRIER WEATHER LOOKS TO RETURN FOR MONDAY THROUGH WEDNESDAY OF NEXT
WEEK...ALLOWING RIVERS AND STREAMS TO SLOWLY RECEDE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR
CTZ001-013.
NY...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR
NYZ038>041-043-047>054-058>061-063>066-082>084.
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY
MORNING FOR NYZ032-033-042.
MA...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR
MAZ001-025.
VT...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR
VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...HWJIV
AVIATION...FRUGIS
FIRE WEATHER...BGM/JPV
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
332 PM EDT FRI MAR 28 2014
.DISCUSSION...
...ROUND OF STORMS OVERNIGHT WITH HEAVY RAIN AND GUSTY WINDS...
TONIGHT...MCS MOVING OFF THE LA COAST AND FL PANHANDLE THIS
AFTERNOON. CONVECTION PROPAGATING SOUTH INTO GREATER INSTABILITY
BUT AWAY FROM BEST MID/UPPER LVL WIND FIELD. SHORT RANGE
GUIDANCE...HRRR RAP AND LOCAL ARW SHOW MCS OR REDEVELOPED
CONVECTION ALONG ITS OUTFLOW BNDRY PUSHING INTO NRN PORTIONS OF
FCST AREA OVERNIGHT...MAINLY AFTER MIDNIGHT. GUIDANCE ALSO
RELATIVELY CONSISTENT IN WEAKENING CONVECTION OVERALL ONCE MCS
GETS AWAY FROM STRONG FORCING PROVIDED BY COUPLED UPPER JET
MCS FEATURE IS UNDER INFLUENCE CURRENTLY. STILL...ACTVTY WILL HAVE
25-30KT H8 WINDS AT ITS DISPOSAL AND CONVECTIVE DOWNDRAFTS WILL HAVE
POTENTIAL FOR STRONG WIND GUSTS. STRONGEST STORMS WILL BE ACROSS
NORTHERN SECTIONS. HAVE INTRODUCED MORE OF A PCPN GRADIENT FROM
NORTH TO SOUTH BASED ON CURRENT MDL TRENDS.
SATURDAY...PLENTY OF LYRD CLOUDINESS WILL BE ACROSS AREA WITH SCT
SHRA IN THE MORNING. ATMOSPHERE WILL BE SLOW TO REGROUP INTO
DIURNAL PHASE DUE TO LOSS OF HEATING WITH EXTENSIVE CLOUD COVER.
MODELS MUCH LESS IN AGREEMENT IN THIS TIME PERIOD IN PART DUE TO
CONVECTIVE DEBRIS AND LOCATION OF RESIDUAL VORT ASSCD WITH OLD
MCS. SFC FRONT WILL APPROACH AREA FROM NORTH LATE IN DAY AS SFC
LOW RAPIDLY INTENSIFIES OVER THE MID ATLC. HAVE LARGELY GONE WITH
GFS POPS...HIGH CHC AREA WIDE...BUT HAVE GONE WELL BELOW GUIDANCE
TEMPS DUE TO AFOREMENTIONED CLOUDS.
SAT NIGHT-SUN...UPPER LEVEL LOW SWINGS THROUGH THE EAST COAST
OVERNIGHT SAT DRIVING THE PARENT LOW OFF THE MID-ATLANTIC COAST AND
THE ASSOCIATED COLD FRONT THROUGH THE FLORIDA PENINSULA. SCATTERED
SHOWERS AND A FEW THUNDERSTORMS POSSIBLE IN THE EVENING AHEAD OF THE
ACTUAL FRONT...THOUGH HOW MUCH ACTIVITY THAT OCCURS DURING THE DAY
MAY AFFECT STABILITY INTO THE EVENING HOURS.
PRECIPITATION TAPERING OFF TOWARDS DAYBREAK WITH MOSTLY SUNNY SKIES
AND DRY CONDITIONS FOR SUNDAY.
MIN TEMPS SAT NIGHT WILL BE IN THE MID 50S NORTH TO UPPER 60S/LOW
70S AROUND LAKE OKEECHOBEE/TREASURE COAST WHERE FRONT WILL JUST BE
CLEARING AROUND SUNRISE SUN.
BREEZY NORTHWEST WINDS ON SUN WILL BRING MAX TEMPS DOWN A FEW
DEGREES FROM SAT INTO SEASONABLE MID-UPPER 70S.
FROM PREVIOUS DISCUSSION
MON-NEXT FRI...HIGH PRESSURE CENTER SHOULD DROP INTO NORTH FLORIDA
MON THEN ONLY GRADUALLY SLIDE SEAWARD INTO LATE WEEK. ONSHORE FLOW
WILL COMMENCE BUT ONLY SLOWLY MODIFY THE INITIALLY VERY DRY AIR
MASS. THE 00Z GFS INDICATED IT REMAINING DRY ENOUGH TO PRECLUDE
POPS THROUGH THE PERIOD. WITH THE HIGH PRESSURE NEARBY MON MORNING
TEMPS LOOK A LITTLE BELOW NORMAL...THEN A GRADUALLY MODERATION TO
A LITTLE ABOVE NORMAL IS INDICATED.
&&
.AVIATION...
MAINLY VFR CONDITIONS OVERNIGHT WITH EXCEPTION OF PERIOD OF
CONVECTIVE ACTVTY MOVING ACROSS MOST LOCATIONS OVERNIGHT. WILL
RESULT IN 2-3 HOUR PERIOD OF MVFR OR IFR CONDITIONS WITH BRIEF HVY
RAIN AND GUSTY WINDS.
&&
.MARINE...
TONIGHT-SAT...WIND SPEEDS HAVE DROPPED BLO SCA AS RIDGE BUIDLS TO
THE EAST. SEAS WILL SUBSIDE GDLY WITH SCEC TO FOLLOW SCA ENDING
LATE THIS AFTN. SOME STRONG STORMS WITH GUSTY WINDS TO MOVE
OFFSHORE TONIGHT AND AGAIN ON SATURDAY.
SUN...COLD FRONT PUSHES THROUGH THE WATERS SAT NIGHT WITH WINDS
BECOMING NE AROUND 20KTS BY DAYBREAK SUN WITH UP TO 25KTS WITH
INITIAL SURGE ESPECIALLY OVER OFFSHORE WATERS NORTH OF SEBASTIAN
INLET. WINDS DIMINISH THROUGH THE DAY ON SUN AS HIGH PRESSURE SLIDES
INTO THE EASTERN US WITH NW WINDS BECOMING 15KTS BY THE AFTERNOON
AND NORTH 10-15KTS OVERNIGHT.
WIND DIRECTION WILL HELP BUILD SEAS OFFSHORE...WITH 6-8FT BY LATE
MORN AND 4-6FT CLOSER TO THE COAST.
MON-TUE...SURFACE HIGH CENTER SLIDES OVER CENTRAL PENINSULA DURING
THE DAY ON MONDAY AND OFFSHORE TUE WILL CAUSE WINDS TO VEER TO THE
NORTHEAST/EAST ON MON AND THEN TO THE EAST ON TUE. SPEEDS LOOK CLOSE
TO 10 KNOTS EXCEPT MAYBE 10-15 KNOTS IN THE SOUTH ON MON. SEAS
INITIALLY 4-6FT OFFSHORE ON MON DIMINISHING 2-4FT BY TUES.
&&
.FIRE WEATHER...
SUN-TUE...POST-FRONTAL NORTHWEST FLOW WILL BRING IN A MUCH DRIER
AIRMASS FOR SUNDAY WITH MIN RH VALUES BELOW 30 PERCENT FOR MOST OF
EAST CENTRAL FLORIDA. SUSTAINED WINDS WILL GENERALLY BE AROUND
10-15MPH...THOUGH OCCASIONAL HIGHER GUSTS WILL BE POSSIBLE EARLIER
IN THE DAY. MIN RH IS FORECAST BELOW 35 PERCENT IN THE NORTH
INTERIOR ON MON...BUT NORTHEAST/EAST WINDS WILL DROP OFF BELOW 10
MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 67 82 58 75 / 70 50 40 0
MCO 67 83 61 77 / 60 50 30 0
MLB 70 83 65 76 / 60 50 40 0
VRB 66 83 67 76 / 60 50 40 10
LEE 66 82 58 75 / 70 50 30 0
SFB 68 83 60 77 / 70 50 30 0
ORL 68 83 60 76 / 70 50 30 0
FPR 70 83 69 76 / 50 50 40 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...LAKE WIND ADVISORY UNTIL 7 PM EDT THIS EVENING FOR COASTAL
VOLUSIA-INDIAN RIVER-INLAND VOLUSIA-MARTIN-NORTHERN BREVARD-
NORTHERN LAKE-OKEECHOBEE-ORANGE-OSCEOLA-SEMINOLE-SOUTHERN
BREVARD-SOUTHERN LAKE-ST. LUCIE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR COASTAL
WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20 NM-
COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM-WATERS FROM FLAGLER BEACH TO
VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS
FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-
WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET
20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...BLOTTMAN
LONG TERM....MOSES
AREA FORECAST DISCUSSION
NWS MIAMI FL
132 PM EDT FRI MAR 28 2014
.AVIATION...
KEPT THE FORECAST VFR THROUGH THE PERIOD AS CURRENT THINKING IS
THAT ANY LOWER CONDITIONS WILL BE LATE SATURDAY MORNING OR DURING
THE AFTERNOON. THE ONLY EXCEPT IS THAT THE HRRR DOES SHOW THE LINE
OF CONVECTION CURRENTLY IN THE FL PANHANDLE TO APPROACH LAKE
OKEECHOBEE AFT 04Z THIS EVENING AND THIS COULD BRING SOME SHRA
EARLIER THAN IN THE FORECAST ESPECIALLY AT APF AND PBI.
INSTABILITY WILL BE ON THE INCREASE TOO ON SATURDAY BUT MOST OF
THE THUNDER THREAT APPEARS TO BE AFT 18Z. SURFACE WIND WILL SLOWLY
DIMINISH THIS AFTERNOON AND THEN VEER TO A S-SSW DIRECTION EARLY
SATURDAY AS THE COLD FRONT APPROACHES.
KOB
&&
.PREV DISCUSSION... /ISSUED 927 AM EDT FRI MAR 28 2014/
UPDATE...
THE ONLY CHANGE MADE TO THE FORECAST WAS TO LOWER POPS THIS
MORNING ACROSS THE REGION. LOW LEVEL MOISTURE WILL START TO
INCREASE THIS AFTERNOON ALLOWING FOR A BETTER CHANCE OF SHOWERS. A
THUNDERSTORM OR TWO CANNOT BE RULED OUT AS WELL MAINLY NEAR LAKE
OKEECHOBEE. CHANCES OF SHOWERS WILL CONTINUE TO INCREASE TONIGHT
OUT AHEAD OF AN APPROACHING COLD FRONT.
PREV DISCUSSION... /ISSUED 732 AM EDT FRI MAR 28 2014/
AVIATION...
MAIN CONCERN TODAY WILL BE GUSTY SOUTHEAST SURFACE WIND TO
OCCASIONALLY OVER 20 KNOTS ALONG THE EAST WITH GRADIENT TOO STRONG
FOR A WEST COAST SEA BREEZE. VFR CONDITIONS WILL PREVAIL WITH A
FEW SHOWERS FROM TIME TO TIME BUT NOT ENOUGH COVERAGE FOR OTHER
THAN VCSH IN THE FORECAST.
KOB
PREV DISCUSSION... /ISSUED 404 AM EDT FRI MAR 28 2014/
DISCUSSION...
HIGH PRESSURE ACROSS THE WESTERN ATLANTIC WILL CONTINUE TO RETREAT
FURTHER TO THE NORTHEAST AND AWAY FROM THE FLORIDA PENINSULA THROUGH
THE DAY. THIS WILL ALLOW A DEEPER MOISTURE AXIS TO PUSH INTO THE
AREA WELL AHEAD OF A DEVELOPING AREA OF LOW PRESSURE ACROSS
SOUTHEAST TEXAS. THIS MEANS INCREASING SHOWER CHANCES ACROSS THE
AREA THIS AFTERNOON. A FEW THUNDERSTORMS MAY ALSO BE POSSIBLE MAINLY
ACROSS THE LAKE OKEECHOBEE REGION AS A FEW MID LEVEL IMPULSES PASS
BY. PRECIPITATION COVERAGE IS EXPECTED TO INCREASE TONIGHT OUT AHEAD
OF AN APPROACHING COLD FRONT IN THE CENTRAL GULF OF MEXICO. THE
ECMWF CURRENTLY DEPICTS LESS QPF OUTPUT THAN THE GFS...SO WENT WITH
A COMPROMISE FOR NOW WITH REGARD TO POPS THROUGH THE NIGHT.
BY SATURDAY A HIGHLY AMPLIFIED H5 SHORTWAVE WILL DIG SOUTHEAST
ACROSS THE MISSISSIPPI VALLEY AND INTO THE APPALACHIANS. AS IT
DOES...ITS ASSOCIATED SURFACE LOW WILL DEEPEN AND PUSH NORTHEAST AND
INTO THE OHIO VALLEY. THIS WILL PUSH THE COLD FRONT ACROSS THE
FLORIDA PENINSULA LATE SATURDAY AND INTO SUNDAY WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS POSSIBLE. CONVECTIVE PARAMETERS CONTINUE
TO LOOK MEAGER WITH THIS SYSTEM AND BETTER DYNAMICS WILL BE WELL
NORTH OF THE AREA. ALSO THE FRONTAL PASSAGE LOOKS TO TAKE PLACE
OVERNIGHT SATURDAY INTO SUNDAY WHICH WOULD ALSO BE UNFAVORABLE FOR
ANY STRONG THUNDERSTORM DEVELOPMENT.
THE FRONT AND ALL ASSOCIATED PRECIPITATION SHOULD EXIT THE AREA BY
MIDDAY SUNDAY GIVING WAY TO DRIER AND MUCH MORE MILD TEMPERATURES
UNDER NORTHERLY FLOW. HIGH PRESSURE WILL THEN DOMINATE THROUGH MOST
OF THE UPCOMING WEEK WITH CONTINUED DRY CONDITIONS AND NEAR NORMAL
TEMPERATURES.
THE GFS HINTS AT ANOTHER FRONT APPROACHING SOUTH FLORIDA BY THE END
OF NEXT WEEK BRINGING ANOTHER ROUND OF SHOWERS BUT THE ECMWF KEEPS
DRY UPPER RIDGING AND SOUTHEAST FLOW.
AVIATION...
VFR WITH BREEZY CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE DAY
AS THE PRESSURE GRADIENT OVER SOUTH FLORIDA CONTINUES TO REMAIN
TIGHT BETWEEN A HIGH TO THE ENE AND A LOW DEVELOPING OVER TEXAS.
WITH THE FLOW SOUTHEASTERLY AND PLENTY OF MOISTURE IN THE
ATMOSPHERE, THERE WILL BE A CHANCE OF SHOWERS. HOWEVER, THERE IS
HIGH UNCERTAINTY WITH THE COVERAGE AND LOCATION. BEST GUESS IS MORE
IN THE LAKE REGION AND NORTH, INTO CENTRAL FLORIDA. SO, NO MENTION
OF RAIN IN THE TAFS AT THIS TIME, ALTHOUGH THERE IS STILL A SLIGHT
POSSIBILITY OF A SHOWER AT A TAF SITE THIS AFTERNOON, ESPECIALLY
KPBI AND EVEN KAPF.
MARINE...
GUSTY SOUTHEASTERLY WINDS WILL CONTINUE ACROSS THE ATLANTIC
WATERS THROUGH THE MORNING WITH 6 TO 8 FOOT SEAS. FLOW WILL THEN
BECOME MORE SOUTHERLY AND THEN SOUTHWESTERLY BY SATURDAY AS A
COLD FRONT APPROACHES. THIS WILL ALLOW SEAS TO DIMINISH
CONSIDERABLY. WINDS AND SEAS WILL THEN QUICKLY INCREASE AGAIN
BEHIND THE FRONT ON SUNDAY INTO MONDAY.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168-172-
173.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
406 PM EDT FRI MAR 28 2014
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL DEVELOP TO THE WEST TONIGHT...PUSHING
A COLD FRONT TOWARD THE REGION. THE COLD FRONT WILL CROSS THE AREA
SATURDAY EVENING...FOLLOWED BY DRY HIGH PRESSURE INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
REST OF THE AFTERNOON AND TONIGHT...THE ONGOING COVERAGE OF SHOWERS
CONTINUES TO FAVOR MOSTLY SOUTHEAST GEORGIA AND THE FAR EASTERN AREA
INCLUDING THE COASTAL WATERS AND EASTERN CHARLESTON COUNTY.
CONVECTION CONTINUES TO BE QUITE SHALLOW THANKS TO THE MID LEVEL
SUBSIDENCE INVERSION NOTED IN THE MORNING SOUNDING. LOOKING AT
REGIONAL RADAR IMAGERY...THE HRRR CONTINUES TO BE THE MODEL BEST
HANDLING THE ONGOING DEEPER CONVECTION ALONG THE GULF AND THE SHOWER
ACTIVITY ACROSS THE FORECAST AREA. IT KEEPS SHOWERS GOING ACROSS THE
FORECAST AREA INTO THE EARLY PART OF THE OVERNIGHT ASSOCIATED WITH A
PASSING MID LEVEL SHORTWAVE NOTED IN WATER VAPOR IMAGERY. I HAVE
THEREFORE CONTINUED TO CARRY LIKELY TO CATEGORICAL POPS TO THE WEST
OVER THE NEXT FEW HOURS...WITH A BAND OF LIKELY AND HIGH CHANCE POPS
MOVING ACROSS FROM WEST TO EAST THROUGH LATE TONIGHT. THE MODELS ARE
PERSISTENT IN SHOWING AN AREA OF IMPROVED MID LEVEL LAPSE RATES AND
NEGATIVE SHOWALTER INDICES NOSING IN FROM THE WEST...SO ELEVATED
CONVECTION REMAINS A POSSIBILITY. A SLIGHT CHANCE OF THUNDER
CONTINUES IN THE FORECAST. BY SATURDAY MORNING...IT APPEARS WE WILL
BE IN A BIT OF A LULL FOR PRECIPITATION. THE MID/UPPER LEVELS BEGIN
TO DRY OUT A BIT AND WE MAY EVEN SEE A BRIEF PERIOD OF SOME NVA
ALOFT IN THE WAKE OF THE DEPARTING SHORTWAVE. THE GENERAL FLOW
REGIME WILL CONTINUE TO BE SOUTHERLY IN THE LOW LEVELS AHEAD OF THE
APPROACHING FRONT. THIS WILL RESULT IN A MILD AND MOIST NIGHT IN THE
ONSHORE FLOW. EXPECT LOWS ONLY IN THE LOW TO MID 60S. ALSO...I HAVE
ADDED PATCHY FOG EVERYWHERE OVERNIGHT. THERE WILL LIKELY BE ENOUGH
SURFACE LEVEL FLOW TO PREVENT FOG FROM BECOMING TOO WIDESPREAD...SO
PATCHY FOG SHOULD COVER IT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
PRIMARY FORECAST ATTENTION FOCUSES ON THE POTENTIAL FOR SEVERE
WEATHER SATURDAY. STARTED THE DAY WITH CHANCE POPS AS MORE
WIDESPREAD SHOWERS SHOULD HAVE EXITED TO THE E/NE. THEN...POPS RAMP
UP TO LIKELY BY EARLY/MID AFTERNOON AS AN AMPLIFYING UPPER
TROUGH/ASSOCIATED COLD FRONT APPROACH THE REGION FROM THE WEST.
FORCING FOR ASCENT AHEAD OF THESE FEATURES...INCLUDING HEIGHT FALLS
AND UPPER DIVERGENCE...700-500 LAPSE RATES EXCEEDING 6 C/KM AND
SUB-ZERO SHOWALTER INDICES AND 0-6 KM BULK SHEAR 40-50 KNOTS ALL
SUGGEST THE POTENTIAL FOR ONE OR MULTIPLE BANDS OF PRE-FRONTAL
CONVECTION PUSHING THROUGH THE REGION WITH AT GUSTY WINDS AND
LOCALLY HEAVY RAINFALL SATURDAY AFTERNOON/EVENING. FORECAST
UNCERTAINTY CENTERS ON THE AMOUNT OF INSOLATION/WARMING AND
ASSOCIATED DEGREE OF SURFACE-BASED INSTABILITY AHEAD OF THE COLD
FRONT. THE 28/12Z NAM SUGGESTS THAT CLOUDS/PRECIPITATION WILL LIMIT
INSTABILITY...AND THE RESULTING SEVERE THREAT WILL REMAIN LIMITED TO
ISOLATED/BRIEF DAMAGING WIND GUSTS. ON THE OTHER HAND...IF
AGGRESSIVE DRY SLOTTING BREAKS UP CLOUDS AND ALLOWS TEMPS TO RECOVER
TO AROUND 80F AS SUGGESTED BY 28/12Z GFS AND EURO
SOLUTIONS...RESULTING SURFACE BASED CAPE 1000-1800 J/KG WILL COMBINE
WITH FAVORABLE KINEMATIC PARAMETERS/SYNOPTIC FORCING TO SUPPORT A
MORE SIGNIFICANT SEVERE WEATHER THREAT...PERHAPS IN THE FORM OF AN
AFTERNOON/EARLY EVENING SQUALL LINE PRODUCING DAMAGING WIND GUSTS
AND EVEN SOME LARGE HAIL/AN ISOLATED TORNADO.
THE COLD FRONT AND ASSOCIATED PRECIPITATION WILL PUSH OFFSHORE
SATURDAY NIGHT. POPS RAMP DOWN STEADILY FROM CHANCE/LIKELY EARLY TO
VIRTUALLY ZERO PERCENT LATE. A SURGE OF COOLER DRIER AIR...DRIVEN BY
GUSTY NORTHWEST WINDS...WILL PUSH TEMPERATURES INTO THE MID/UPPER
40S AT MOST LOCATIONS BY SUNDAY MORNING.
BETWEEN DEEPENING LOW PRESSURE EXITING THE MID ATLANTIC COAST AND
HIGH PRESSURE BUILDING FROM THE W/NW...SUNDAY WILL FEATURE BREEZY
AND DRY CONDITIONS ACCOMPANIED BY TEMPERATURES IN THE UPPER 60S TO
LOWER 70S...JUST A SHADE BELOW NORMAL FOR LATE MARCH.
AS HIGH PRESSURE SHIFTS EAST AND WINDS DIMINISH SUNDAY
NIGHT...RADIATIONAL COOLING WILL SUPPORT LOW TEMPS IN THE LOWER TO
MID 40S MOST LOCATIONS. WELL INLAND...THE COOLEST LOCATIONS COULD
BOTTOM OUT IN THE UPPER 30S...BUT THE PROBABILITY FOR ANY FROST WILL
REMAIN VERY LOW.
MONDAY...UNDER HIGH PRESSURE TEMPERATURES WILL RECOVER INTO AT LEAST
THE MID 70S AWAY FROM THE BEACHES. A SEA BREEZE WILL DEVELOP AND
WILL PUSH INLAND MONDAY AFTERNOON.
LAKE WINDS...GUSTY WINDS AND CHOPPY WAVES COULD DEVELOP ON LAKE
MOULTRIE...ESPECIALLY SATURDAY NIGHT AND SUNDAY. A LAKE WIND
ADVISORY COULD EVENTUALLY BE REQUIRED.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A BROAD UPPER LEVEL RIDGE WILL PREVAIL MONDAY NIGHT THROUGH THURSDAY
WITH DRY HIGH PRESSURE AT THE SURFACE. THIS WILL RESULT IN ABOVE
NORMAL TEMPERATURES WITH HIGHS CLIMBING INTO THE UPPER 70S OR LOWER
80S AND LOWS MAINLY IN THE 50S. THE UPPER RIDGE BREAKS DOWN ON
FRIDAY WITH A WEAK COLD FRONT POSSIBLY MOVING IN FROM THE WEST.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
EXPECT UNSETTLED CONDITIONS THROUGH 18Z SATURDAY. SCATTERED TO
NUMEROUS SHOWERS HAVE DEVELOPED NEAR THE TERMINALS THIS AFTERNOON
SO A VCSH HAS BEEN ADDED. ALSO...TO ACCOUNT FOR DIRECT
IMPACTS...MVFR CONDITIONS HAVE BEEN ADDED IN A TEMPO GROUP THAT
RUNS THROUGH LATE AFTERNOON MAINLY FOR CEILINGS BUT ALSO FOR
VISIBILITIES AS RAINFALL BRIEFLY BECOMES MODERATE. THERE IS A LOW
CHANCE FOR A RUMBLE OF THUNDER...BUT THE PROBABILITY IS TOO LOW TO
INCLUDE IN THE FORECAST. THIS EVENING AND THROUGH THE OVERNIGHT...IT
IS BECOMING INCREASINGLY LIKELY THAT WIDESPREAD MVFR CEILINGS WILL
DEVELOP. I HAVE TIMED THIS INTO KSAV AT 00Z AND INTO KCHS AT 03Z.
WE WILL LIKELY SEE ADDITIONAL PERIODS OF SHOWERS AT BOTH SITES
LATE THIS EVENING BEFORE THIS AREA OF PRECIPITATION PUSHES OFF TO
THE EAST LATE. GUIDANCE CONTINUES TO INDICATE A LOW TO MODERATE
CHANCE OF IFR CONDITIONS LATE TONIGHT. PROBABILITIES ARE HIGHEST
AT KSAV...BUT I/M NOT READY TO COMMIT TO PREVAILING IFR THIS FAR
OUT. I HAVE TRENDED KSAV DOWN INTO THE LOW END MVFR RANGE STARTING
AT 06Z AND CONTINUING THROUGH THE MID MORNING. CEILINGS SHOULD
LIFT TO LOW END VFR MID/LATE SATURDAY MORNING. A COLD FRONT AND AN
INCREASING POTENTIAL FOR THUNDERSTORMS ALONG IT WILL APPROACH
SATURDAY AFTERNOON. SHOWERS OUT AHEAD OF THE FRONT WILL DEVELOP
FIRST AT KSAV AND WINDS WILL BEGIN TO PICK UP AND BE GUSTY OUT OF
THE SOUTH. THIS WILL ALSO HAPPEN AT KCHS...THOUGH LATER...AND HAS
NOT BEEN INCLUDED AT THIS TIME.
EXTENDED AVIATION OUTLOOK...OCCASIONAL FLIGHT RESTRICTIONS POSSIBLE
SATURDAY AFTERNOON AND EVENING IN SHOWERS/SCATTERED THUNDERSTORMS.
VFR CONDITIONS EXPECTED THEREAFTER. BREEZY CONDITIONS EXPECTED
SATURDAY NIGHT THROUGH SUNDAY.
&&
.MARINE...
REST OF THE AFTERNOON AND TONIGHT...PERSISTENT SOUTHEASTERLY FLOW
HAS CONTINUED TODAY BETWEEN THE HIGH OVER THE OPEN ATLANTIC AND THE
COLD FRONT TO THE WEST. THE COOL SEA SURFACE TEMPERATURES...ESPECIALLY
OVER THE SHELF WATERS...HAS PREVENTED WINDS FROM GETTING MUCH
STRONGER THAN 10 TO 15 KT THUS FAR. ONE SURPRISE HAS BEEN THE
RAPID INCREASE IN SEAS...PRIMARILY COMPRISED OF A 7 SECOND SWELL.
41008 HAS REPORTED SEAS UP TO ALMOST 8 FT AND 41008 IS NOW
REACHING TO AROUND 5 FT. DUE TO THESE OBSERVATIONS WE HAVE HOISTED
A SMALL CRAFT ADVISORY FOR THE OUTER GEORGIA WATERS THAT STARTS
NOW AND RUNS THROUGH THE NIGHT. 6 FT SEAS ARE EXPECTED TO DRAW
CLOSER TO SHORE AND BEGIN GET INTO THE NEARSHORE WATERS ALONG THE
CHARLESTON COUNTY COAST AFTER MIDNIGHT. A SMALL CRAFT ADVISORY HAS
BEEN INITIALIZED AT THAT TIME AND RUNS INTO SATURDAY.
OVERALL...WINDS WILL REMAIN IN THE 10-15 KT RANGE...PERHAPS UP TO
20 KT BEYOND 20 NM...THOUGH TONIGHT IN THE SOUTHERLY FLOW. ANOTHER
CONCERN IN THE MOIST SOUTHERLY FLOW IS THE POTENTIAL FOR SEA FOG
TO DEVELOP OVERNIGHT. I HAVE ADDED PATCHY FOG AFTER MIDNIGHT AS A
RESULT.
CONDITIONS WILL REMAIN FAVORABLE FOR SEA FOG UNTIL A COLD FRONT
CROSSES THE WATERS WITH MUCH DRIER AIR SATURDAY EVENING. THE
FORECAST INDICATES PATCHY FOG...BUT MORE WIDESPREAD FOG COULD PROMPT
DENSE FOG ADVISORIES.
SATURDAY THROUGH TUESDAY...ELEVATED SEAS WILL PERSIST...AND SOUTHERLY
WINDS WILL INCREASE TO 15-20 KT...WITH GUSTS TO 25 KT POSSIBLE
BEYOND 20 NM...AHEAD OF AN APPROACHING COLD FRONT. AFTER COLD
FROPA...SMALL CRAFT ADVISORY NORTHWEST WINDS/HAZARDOUS SEAS WILL
PREVAIL THROUGH SUNDAY. W/NW WINDS WILL GRADUALLY DIMINISH SUNDAY
NIGHT...AND HIGH PRESSURE WILL SHIFT OVER THE WATERS AND WILL
PROVIDE MUCH LIGHTER WINDS AND SUBSIDING SEAS MONDAY-TUESDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 5 PM EDT SUNDAY
FOR AMZ352.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT SUNDAY FOR AMZ374.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM EDT SUNDAY
FOR AMZ350.
&&
$$
SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...SPR
LONG TERM...JRL
AVIATION...BSH/SPR
MARINE...BSH/SPR
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
246 PM EDT FRI MAR 28 2014
.PREV DISCUSSION... /ISSUED 1040 AM EDT FRI MAR 28 2014/
UPDATE...
HAVE MADE SIGNIFICANT ADJUSTMENTS TO THE FORECAST TO ACCOUNT FOR
LATEST THINKING WITH TODAYS WEATHER. AXIS OF PRECIPITATION IS
FURTHER SOUTH THAN ORIGINALLY ANTICIPATED...AND PREVIOUS FORECAST
POP AND WX GRIDS DID NOT MATCH THIS POSITIONING.
OVERALL...MODEL GUIDANCE WITH THIS SYSTEM IS POOR...WITH VERY FEW
DEPICTING THE CURRENT RADAR TRENDS WELL. HAVE OVERALL GONE WITH
THE HRRR WHICH SEEMS TO HAVE A BETTER HANDLE ON THE CURRENT
CONDITIONS. THE HRRR DOES SUGGEST MUCH OF THE COMPLEX IN MS/AL
WILL ORGANIZE INTO THIS AFTERNOON...BECOMING MORE LINEAR IN
NATURE...AND PUSHING ACROSS SOUTHWEST GEORGIA. ALTHOUGH THERE IS A
QUESTION OF WHETHER THIS LINEAR CONVECTION WILL MATERIALIZE...THE
HRRR CONTINUES TO SHOW MUCH OF NORTH GEORGIA CUT OFF FROM GULF
MOISTURE...AND LIMITS THE AMOUNT OF PRECIP OVER THE NORTHERN
SECTIONS OF THE CWA. AS A RESULT...HAVE CONTINUED THE TREND OF
HIGHEST POPS ACROSS CENTRAL GEORGIA INTO THE OVERNIGHT PERIOD.
WILL CONTINUE TO UPDATE THE GRIDS AS NECESSARY...ESPECIALLY THE
NEXT 24 HOURS.
31
PREV DISCUSSION... /ISSUED 717 AM EDT FRI MAR 28 2014/
PREV DISCUSSION... /ISSUED 341 AM EDT FRI MAR 28 2014/
SHORT TERM /TODAY THROUGH SATURDAY/...
SURFACE ANALYSIS SHOWS A COLD FRONT STRETCHING FROM THE CENTRAL
GREAT LAKES BACK THROUGH THE ARKLATEX. A LARGE AREA OF PRECIPITATION
HAS DEVELOPED TO THE EAST OF THE BOUNDARY AN IS MOVING INTO NW
PORTIONS OF THE CWFA. PRECIP WILL CONTINUE TO INCREASE FOR MUCH OF
THE AREA TODAY AS THE FRONT SLOWLY PUSHES EASTWARD.
THE NORTHERN END OF THE FRONT WILL MAKE SOME EASTWARD PROGRESS
TODAY...WHILE THE SOUTHERN END WILL LAG UNTIL EARLY SATURDAY
MORNING. A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE SOUTHERN TAIL
OF THE FRONT TONIGHT...AND FINALLY HELP PUSH THE FRONT THROUGH THE
CWFA ON SATURDAY. THE NORTHERN END OF THE FRONT WILL BECOME
TEMPORARILY STATIONARY NEAR THE TN/GA BORDER THIS EVENING AND
OVERNIGHT. EXPECT SHOWERS AND A FEW THUNDERSTORMS TO TRAIN ACROSS
THE NORTHERN HALF OF THE CWFA...IN THE VICINITY OF THE BOUNDARY
TONIGHT.
MODELS SHOWING A BIT MORE INSTABILITY ACROSS THE SOUTHERN CWFA FOR
THIS AFTERNOON THAN IN PREVIOUS RUNS. STILL...ONLY A COUPLE HUNDRED
JULES OF CAPE. WILL KEEP THUNDER CHANCES AT A MINIMUM TODAY AND ONLY
MENTION A SLIGHT CHANCE. EVEN THOUGH A BREAK IN THE WIDESPREAD
PRECIPITATION IS EXPECTED THIS EVENING...THE CHANCES FOR THUNDER
WILL SLIGHTLY INCREASE AS A MID LEVEL SHORTWAVE TRAVERSES THE AREA
AND STEEPENS LAPSE RATES. STILL...SURFACE INSTABILITY WILL BE
LIMITED...SO WILL CAP THE THUNDER WORDING AT A CHANCE. A BIT MORE
INSTABILITY WILL BE PRESENT SATURDAY AFTERNOON...ESPECIALLY ACROSS
THE SOUTHEAST PORTION OF THE CWFA. THIS AREA HAS THE POTENTIAL FOR
SOME HEATING...WITH TEMPS IN THE LOWER TO MIDDLE 70S. SURFACE BASED
CAPES SHOULD RANGE FROM 500 TO 1000 J/KG. THE BEST SHEAR SHOULD
LAG...ALONG WITH THE FRONTAL BOUNDARY. HOWEVER...WILL NOT RULE OUT
STRONG THUNDERSTORMS WITH ISOLATED SEVERE STORMS POSSIBLE. DAMAGING
WIND GUSTS SHOULD BE THE PRIMARY MODE OF SEVERE WEATHER.
NLISTEMAA
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
FOR THE MOST PART...SYSTEM THAT BRINGS RAIN TO THE AREA IN THE
SHORT TERM SHOULD HAVE EXITED THE AREA BY THE BEGINNING OF THE
LONG TERM. THE EXCEPTION TO THIS IS ACROSS FAR NORTHEAST GEORGIA
AND THE FAR SOUTHEAST PART OF THE CWA WHERE SOME RAIN COULD LINGER
THROUGH SATURDAY NIGHT. AT THIS POINT...IT APPEARS THE
PRECIPITATION SHOULD END ACROSS THE NE GA MOUNTAINS BEFORE THE
COOLER TEMPERATURES MOVE IN. AFTER THIS HIGH PRESSURE WILL
DOMINATE THROUGH ABOUT MID WEEK. BOTH THE GFS AND THE ECMWF
SUGGEST THE NEXT SYSTEM MOVING THROUGH IN THE LATER HALF OF THE
WEEK. INSTABILITY VALUES SUPPORT THE MENTION OF THUNDER IN THE
FORECAST THURSDAY INTO FRIDAY.
11
HYDROLOGY...
ONE CONCERN FOR THE FORECAST PERIOD IS LOCALLY HEAVY RAINFALL. PWATS
JUST UNDER AN INCH AND HALF WILL BE LIKELY THIS AFTERNOON THROUGH
SATURDAY. THESE NUMBERS ARE VERY CLOSE TO BEING 2SD ABOVE NORMAL FOR
THIS TIME OF YEAR. 6HR FFG GUIDANCE RANGES FROM AROUND 2 TO 3
INCHES ACROSS THE CWFA. STORM TOTAL PRECIP FROM TODAY THROUGH
SATURDAY NIGHT AVERAGES AN INCH AND A HALF TO JUST ABOUT TWO AND
THREE QUARTERS OF AN INCH. SINCE THE RAINFALL IS EXPECTED TO BE OVER
A LONGER PERIOD OF TIME...FF ISN`T A MAJOR CONCERN AT THIS TIME.
HOWEVER...WHERE THUNDERSTORMS REPEATEDLY TRAIN...SOME LOCALIZED FF
IS POSSIBLE. DO EXPECT SOME RISES ON THE RIVERS BUT NOT CONFIDENT
ENOUGH TO SAY IF RIVERS WILL GO INTO FLOOD YET.
NLISTEMAA
&&
.AVIATION...
18Z UPDATE...
RAIN CONTINUES ACROSS THE AREA THIS AFTERNOON...AND TAF SITES ARE
LARGELY IFR. ANTICIPATE THE IFR CIGS TO CONTINUE INTO THE
OVERNIGHT PERIOD. ATL AND AHN AREA TAFS WILL SEE A BREAK IN THE
RAIN UNTIL 05-06Z. MCN AND CSG CAN EXPECT TO SEE RAINFALL INTO THE
EVENING HOURS. RAIN WILL TAPER OFF INTO THE OVERNIGHT PERIOD...AND
START BACK UP AROUND 06-08Z. TS POTENTIAL FOR SATURDAY IS STILL
LOW ENOUGH WHERE IT IS NOT ADVERTISED IN ANY TAFS AT THIS TIME.
THE BEST TIMING WOULD BE FROM 15-20Z SATURDAY IN THE CSG AND MCN
AREAS AND SOUTHWARD. SE WINDS WILL PERSIST THROUGH 10-12Z AS THE
FRONT PUSHES THROUGH THE ATL AREA AND SHIFTS WINDS TO THE NW. CSG
AND MCN WILL SEE THIS SHIFT CLOSER TO 14-16Z. SPEEDS WILL INCREASE
TO 10-15KT WITH GUSTS TO 20-25KT BY LATE SATURDAY MORNING.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON ALL ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 54 72 42 / 100 60 70 5
ATLANTA 62 56 69 42 / 100 70 70 5
BLAIRSVILLE 57 52 65 37 / 100 70 80 10
CARTERSVILLE 61 56 69 41 / 100 80 70 5
COLUMBUS 64 60 73 47 / 100 70 60 5
GAINESVILLE 58 53 68 41 / 100 70 80 5
MACON 65 58 74 44 / 100 60 60 5
ROME 62 56 68 42 / 100 80 80 5
PEACHTREE CITY 63 56 71 41 / 100 70 70 5
VIDALIA 69 60 75 48 / 100 80 60 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....BAKER
AVIATION...31
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
200 PM EDT FRI MAR 28 2014
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL AS WEAK UPPER DISTURBANCES
MOVE THROUGH THE AREA TODAY AND TONIGHT. A COLD FRONT WILL CROSS
THE REGION SATURDAY AFTERNOON AND EVENING...FOLLOWED BY DRY HIGH
PRESSURE THROUGH THURSDAY. A COLD FRONT MAY AFFECT THE AREA NEXT
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS AFTERNOON...AS EXPECTED CONVECTION HAS REMAINED QUITE
SHALLOW SO FAR AND HAS BEEN ON A BIT OF A DIMINISHING TREND AS IT
PUSHES IN FROM THE WEST. THERE ARE TWO MAIN AREAS OF PRECIPITATION
AT THIS POINT...THE ONE TO THE WEST ASSOCIATED WITH THE UPPER
SHORTWAVE AND UPSTREAM CONVECTION...AND THE ONE TO THE EAST WHICH
IS WHERE THE MORNING SHOWERS FIRST STARTED IN THE SOUTHERLY
MOISTURE FEED. I HAVE MADE SOME TWEAKS TO POPS TO BETTER MATCH
ONGOING CONDITIONS...AS WELL AS TEMPERATURES...BUT THE OVERALL
FORECAST REMAINS ON TRACK.
LATE THIS MORNING...CLOUDS HAVE STEADILY FILLED IN ACROSS THE
FORECAST AREA WITH MUCH OF IT BECOMING OVERCAST NOW. THERE ARE
STILL SOME BREAKS ON VISIBLE SATELLITE IMAGERY...BUT THESE SHOULD
FILL IN THROUGH THE DAY ESPECIALLY AS MID/HIGH CLOUDS STREAM IN
FROM ONGOING CONVECTION TO THE WEST. RADAR IMAGERY SHOWS PERIODIC
SHOWERS MOVING ONSHORE IN THE SOUTHERLY FLOW...MAINLY AFFECTING
CHARLESTON AND BERKELEY COUNTIES THIS MORNING. DIAGNOSING WHAT IS
CURRENTLY GOING ON AROUND THE REGION...THERE IS A FAIRLY LARGE
COMPLEX OF CONVECTION ONGOING ALONG THE GULF COAST FROM AROUND
NEW ORLEANS TO THE WESTERN FLORIDA PANHANDLE. BASED ON REGIONAL
RAOB/S THIS CONVECTION APPEARS TO BE ASSOCIATED WITH AN AREA OF
ELEVATED INSTABILITY. THIS IS FURTHER SUPPORTED BY NEGATIVE
SHOWALTER INDICES FROM THE RAP AND AN AREA OF ENHANCED MID LEVEL
LAPSE RATES NOTED FROM THE SPC MESOANALYSIS PAGE. FOR
INSTANCE...COMPARING THE 12Z KTLH AND KCHS SHOWS SIMILAR MID LEVEL
ENVIRONMENTS OTHER THAN THE PROMINENT SUBSIDENCE INVERSION NOTED
IN THE KCHS SOUNDING AT AROUND 650 MB. THIS INVERSION IS SUPPORTED
BY INTERROGATING ALL TILTS RADAR OF THE CURRENT SHOWER
ACTIVITY...WHICH SHOWS THE DEPTH OF REFLECTIVITY SHUTTING OFF
AROUND 11 KFT...WHICH IS NEAR THE 650 MB LEVEL. SO THE BEST MID
LEVEL ENVIRONMENT IS CERTAINLY TO OUR WEST AND SOUTHWEST AND BASED
ON CURRENT HI-RES MODEL RUNS IT APPEARS THAT WILL CONTINUE THROUGH
THE DAY. THE 11Z HRRR APPEARS TO BE HANDLING THE ONGOING
CONVECTION THE BEST...AND THROUGH THE DAY IT TAKES THE MOST
INTENSE UPSTREAM CONVECTION IN A SOUTHEASTWARD DIRECTION OVER THE
FLORIDA PANHANDLE AND THE EASTERN GULF. THIS SEEMS REASONABLE AS
THE BEST MID LEVEL ENVIRONMENT AND LATER SURFACE BASED INSTABILITY
WILL BE TO THE SOUTH AND SOUTHEAST OF ITS CURRENT LOCATION.
SO...FOR THE FORECAST AREA...THE THINKING IS THAT WE WILL CONTINUE
TO SEE SHALLOW CONVECTION AT BEST. I HAVE ADJUSTED POPS
ACCORDINGLY...AND THE SCHEME FAVORS THE EASTERN AREAS NOW AND THEN
THE WESTERN AREAS LATER AS THE DIMINISHING UPSTREAM
SHOWERS/CONVECTION ATTEMPT TO PUSH IN. WITH THE CLOUD COVER
ONGOING AND EXPECTED...HIGH TEMPERATURES ARE TRICKY. I HAVE
LOWERED VALUES MORE INTO THE LOW TO MID 70S...BUT THIS COULD BE ON
THE LOW END IF WE GET MORE SUN THAN EXPECTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
TONIGHT...ATLANTIC HIGH PRESSURE WILL PREVAIL AS A COLD FRONT
APPROACHES FROM THE TENNESSEE VALLEY AND DEEP SOUTH. SOUTHERLY
FLOW WILL CONTINUE TO ADVECT DEEP MOISTURE INTO THE REGION. THE
COMBINATION OF THE DEEP LAYERED MOISTURE...FORCING FOR ASCENT
ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL
JET...AND A POTENT SHORT WAVE PASSING ALOFT WILL SUPPORT SCATTERED
TO NUMEROUS SHOWERS ACROSS THE AREA...ESPECIALLY LATE THIS EVENING
AND OVERNIGHT. IN ADDITION...INSTABILITY PARAMETERS/MID LEVEL
LAPSE RATES ARE SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORMS AS
WELL. TEMPERATURES WILL NOT FALL SIGNIFICANTLY GIVEN THE SOUTHERLY
FLOW AND CLOUD COVER...WITH LOWS EXPECTED TO BE AROUND 60 IN MOST
AREAS.
A POTENT UPPER SHORTWAVE WILL MOVE INTO THE CENTRAL APPALACHIANS
ON SATURDAY. SOUTHWEST FLOW WILL STRENGTHEN CONSIDERABLY AS THE
DAY WEARS ON...WITH 0-6 KM WINDS 40-45 KT BY 00Z SUN. THIS WILL
ALSO INCREASE MOISTURE ACROSS THE AREA WITH PWATS ABOVE 1.50
INCHES BY 18Z SAT. A COLD FRONT IS EXPECTED TO SWEEP THROUGH THE
AREA SATURDAY EVENING. THERE REMAINS CONSIDERABLE UNCERTAINTY
REGARDING THE DEGREE OF BOUNDARY LAYER DESTABILIZATION AHEAD OF
THE FRONT. GIVEN THE EXTENSIVE LOW-LEVEL MOISTURE ADVECTING INTO
THE REGION DURING THE DAY WE WOULD EXPECT TO HAVE QUITE A BIT OF
LOW STRATOCUMULUS IN PLACE. HOWEVER SOME OF THE GUIDANCE IS
DEPICTING A WEAK DRY SLOT DURING THE MIDDAY HOURS AFTER A BATCH OF
MORNING PRECIP MOVES THROUGH. BOTH THE GFS AND NAM ARE SHOWING
1500 J/KG CAPES WITH LIFTED INDICES BELOW -4C DURING THE AFTERNOON
ACROSS SOUTHEAST GA. THIS COINCIDES WITH 40-45 KT OF BULK SHEAR.
IT IS ALSO WORTH NOTING THAT THE STORM PREDICTION CENTER STILL
SHOWS OUR ENTIRE FORECAST AREA WITHIN THE DAY 2 SLIGHT RISK. WE
PLAN TO ADD MENTION OF POSSIBLE SEVERE WEATHER TO THE HAZARDOUS
WEATHER OUTLOOK.
STRONG LOW-LEVEL WARM ADVECTION AND PRE-FRONTAL COMPRESSION ON
SATURDAY WILL PUSH HIGH TEMPS INTO THE UPPER 70S. THIS COULD
POTENTIALLY BE TOO COOL IF SOME BREAKS DEVELOP IN THE CLOUDS.
CONSIDERABLE COVERAGE OF SHOWERS AND THUNDERSTORMS IS EXPECTED
THROUGH SATURDAY EVENING BEFORE PRECIP TAPERS OFF BEHIND THE FRONT.
A SLIGHT COOL DOWN IS EXPECTED FOR SUNDAY DUE TO COLD ADVECTION WITH
THE HIGH BUILDING IN...HOWEVER DOWNSLOPE FLOW WILL ALLOW TEMPS TO
REACH 70 OR THEREABOUTS. A 30-35 KT GEOSTROPHIC WIND FIELD AND DEEP
MIXING WILL RESULT IN BREEZY CONDITIONS ESPECIALLY DURING THE HOURS
OF PEAK HEATING.
DRY WEATHER WITH MODERATING TEMPERATURES EXPECTED ON MONDAY WITH
HIGHS REBOUNDING INTO THE LOWER TO MIDDLE 70S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A BROAD UPPER LEVEL RIDGE WILL PREVAIL MONDAY NIGHT THROUGH THURSDAY
WITH DRY HIGH PRESSURE AT THE SURFACE. THIS WILL RESULT IN ABOVE
NORMAL TEMPERATURES WITH HIGHS CLIMBING INTO THE UPPER 70S OR LOWER
80S AND LOWS MAINLY IN THE 50S. THE UPPER RIDGE BREAKS DOWN ON
FRIDAY WITH A WEAK COLD FRONT POSSIBLY MOVING IN FROM THE WEST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
EXPECT UNSETTLED CONDITIONS THROUGH 18Z SATURDAY. SCATTERED TO
NUMEROUS SHOWERS HAVE DEVELOPED NEAR THE TERMINALS THIS AFTERNOON
SO A VCSH HAS BEEN ADDED. ALSO...TO ACCOUNT FOR DIRECT
IMPACTS...MVFR CONDITIONS HAVE BEEN ADDED IN A TEMPO GROUP THAT
RUNS THROUGH LATE AFTERNOON MAINLY FOR CEILINGS BUT ALSO FOR
VISIBILITIES AS RAINFALL BRIEFLY BECOMES MODERATE. THERE IS A LOW
CHANCE FOR A RUMBLE OF THUNDER...BUT THE PROBABILITY IS TOO LOW TO
INCLUDE IN THE FORECAST. THIS EVENING AND THROUGH THE OVERNIGHT...IT
IS BECOMING INCREASINGLY LIKELY THAT WIDESPREAD MVFR CEILINGS WILL
DEVELOP. I HAVE TIMED THIS INTO KSAV AT 00Z AND INTO KCHS AT 03Z.
WE WILL LIKELY SEE ADDITIONAL PERIODS OF SHOWERS AT BOTH SITES
LATE THIS EVENING BEFORE THIS AREA OF PRECIPITATION PUSHES OFF TO
THE EAST LATE. GUIDANCE CONTINUES TO INDICATE A LOW TO MODERATE
CHANCE OF IFR CONDITIONS LATE TONIGHT. PROBABILITIES ARE HIGHEST
AT KSAV...BUT I/M NOT READY TO COMMIT TO PREVAILING IFR THIS FAR
OUT. I HAVE TRENDED KSAV DOWN INTO THE LOW END MVFR RANGE STARTING
AT 06Z AND CONTINUING THROUGH THE MID MORNING. CEILINGS SHOULD
LIFT TO LOW END VFR MID/LATE SATURDAY MORNING. A COLD FRONT AND AN
INCREASING POTENTIAL FOR THUNDERSTORMS ALONG IT WILL APPROACH
SATURDAY AFTERNOON. SHOWERS OUT AHEAD OF THE FRONT WILL DEVELOP
FIRST AT KSAV AND WINDS WILL BEGIN TO PICK UP AND BE GUSTY OUT OF
THE SOUTH. THIS WILL ALSO HAPPEN AT KCHS...THOUGH LATER...AND HAS
NOT BEEN INCLUDED AT THIS TIME.
EXTENDED AVIATION OUTLOOK...OCCASIONAL FLIGHT RESTRICTIONS POSSIBLE
SATURDAY AFTERNOON AND EVENING IN SCATTERED SHOWERS AND
THUNDERSTORMS. VFR CONDITIONS EXPECTED THEREAFTER. BREEZY CONDITIONS
EXPECTED ON SUNDAY.
&&
.MARINE...
TODAY...A SOUTHERLY RETURN FLOW WILL BECOME WELL ESTABLISHED
ACROSS THE COASTAL WATERS TODAY AS ATLANTIC HIGH PRESSURE
PREVAILS. DESPITE SOME STRONGER WINDS ALOFT...MIXING WILL REMAIN
LIMITED OVER THE COOLER NEAR SHORE WATERS THUS WINDS AT THE
SURFACE SHOULD NOT EXCEED 10 TO 15 KT. HOWEVER...WINDS OVER THE
OUTER GA WATERS AND IN CHARLESTON HARBOR ALONG THE LAND/SEA
INTERFACE COULD REACH UPWARDS OF 15 TO 20 KT AT TIMES THIS
AFTERNOON. A SOUTHEAST SWELL WILL KEEP SEAS ELEVATED IN THE 3-5 FT
RANGE TODAY...WITH A SMALL POTENTIAL FOR SOME 6 FT SEAS TO
ENCROACH UPON THE FAR REACHES OF THE OUTER GA WATERS. GIVEN
LIMITED CONFIDENCE...HAVE OPTED TO NOT ISSUE A SMALL CRAFT
ADVISORY...ALTHOUGH CONDITIONS COULD WARRANT OTHERWISE LATER
TODAY. DEW POINTS SURGING INTO THE LOWER 60S WITHIN THE SOUTHERLY
FLOW COULD SUPPORT THE DEVELOPMENT OF PATCHY SEA FOG LATER THIS
AFTERNOON ACROSS THE NEAR SHORE WATERS.
TONIGHT...THE SOUTHERLY FLOW WILL STRENGTHEN TO UPWARDS OF 15 TO
20 KT ACROSS THE COASTAL WATERS AS THE SURFACE PRESSURE GRADIENT
TIGHTENS BETWEEN ATLANTIC HIGH PRESSURE AND A COLD FRONT WELL TO
THE WEST. A SOUTHEAST SWELL WILL KEEP SEAS SOLIDLY IN THE 3-5 FT
RANGE...HIGHEST ACROSS THE OUTER GA WATERS. THERE IS A SMALL
POTENTIAL THAT MARGINAL SMALL CRAFT ADVISORY CONDITIONS FOR WINDS
AND/OR SEAS COULD OCCUR OVER THE OUTER GA WATERS...BUT NOT ENOUGH
CONFIDENCE TO RAISE AN ADVISORY AT THIS TIME. THE POTENTIAL FOR
PATCHY SEA FOG WILL PERSIST TONIGHT ACROSS THE NEAR SHORE WATERS
AND CHARLESTON HARBOR AS A WARM/MOIST SOUTHERLY FLOW PREVAILS.
SATURDAY THROUGH TUESDAY...WIND FIELDS WILL INCREASE SATURDAY INTO SATURDAY
NIGHT AS A STRONG COLD FRONT MOVES THROUGH. ON SATURDAY THE FLOW
WILL BE OUT OF THE SOUTH AND CONDITIONS SHOULD REMAIN BELOW
ADVISORY CRITERIA. BUT ONCE COLD ADVECTION CRANKS UP LATE SATURDAY
EVENING AND OVERNIGHT AND GEOSTROPHIC WINDS INCREASE TO 35-40
KT...WE EXPECT SMALL CRAFT ADVISORY CONDITIONS ON MOST IF NOT ALL
MARINE ZONES. CONDITIONS WILL QUICKLY IMPROVE ON SUNDAY AS THE
HIGH PRESSURE CENTER MOVES CLOSER TO THE WATERS. FAIRLY QUIET
WINDS/SEAS ANTICIPATED SUNDAY NIGHT THROUGH MID WEEK AS THE HIGH
PRESSURE DOMINATES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...BSH
MARINE...JAQ/JRL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1253 PM CDT FRI MAR 28 2014
.DISCUSSION...
1018 AM CDT
HAVE MADE SOME ADJUSTMENTS TO SKY GRIDS TODAY TO BE A BIT LESS
OPTIMISTIC WITH CLEARING. LOW LEVEL MOISTURE/STRATUS IS CURRENTLY
TRAPPED UNDER A FAIRLY SHARP INVERSION AND INVERSION IS LIKELY TO
PERSIST NOT OFFERING MUCH HOPE FOR BETTER MIXING. CLEARING LINE
OVER CENTRAL WISCONSIN IS MAKING FAIRLY QUICK PROGRESS SOUTHWARD
AND WILL PROBABLY MAKE IT INTO AT LEAST OUR NORTHERN CWA THIS
AFTERNOON...THOUGH WITH LOW LEVEL FLOW SLACKENING THIS AFTERNOON
AND VEERING NE WOULD EXPECT THIS CLEARING LINE TO SLOW DOWN A BIT.
ASSUMING CLOUD COVER LINGERS INTO THE AFTERNOON...TEMPERATURES
WILL BE SLOW TO RECOVER AND HAVE SHAVED A FEW DEGREES OFF GOING
HIGH TEMPS.
UPDATED GRIDS/TEXT PRODUCTS HAVE BEEN SENT.
IZZI
//PREV DISCUSSION...
323 AM CDT
TODAY...
SURFACE COLD FRONT IS CLEARING THE EASTERN COUNTIES IN THE CWA EARLY
THIS MORNING WHILE A SECONDARY TROUGH IS DIGGING ACROSS NORTHERN
ILLINOIS WITH WINDS TURNING SHARPLY TO THE NNW WITH GUSTS WELL INTO
THE 20 KT RANGE. SHOWERS BEHIND THIS TROUGH WILL SWEEP ACROSS
NORTHERN ILLINOIS AND NORTHWEST INDIANA...EXITING TO THE EAST BY MID
TO LATE MORNING. BREEZY CONDITIONS THIS MORNING SHOULD GRADUALLY
TAPER THROUGH THE DAY AS THE AS THE LOW LIFTS TOWARDS QUEBEC AND
FILLS. TEMPS INTO THE MID TO UPPER 40S ARE EXPECTED THIS
AFTERNOON...BUT A LAKE BREEZE WILL TURN WINDS NORTHEASTERLY AND COOL
TEMPS BACK INTO THE 30S ALONG THE LAKE.
THIS WEEKEND...
LOW PRESSURE WILL LIFT FROM ARKLATEX INTO THE UPPER OHIO VALLEY BY
MIDDAY SATURDAY. BEST CHANCES FOR PRECIP WILL BE SOUTH OF I-80
ESPECIALLY IN NORTHWEST INDIANA...AND FOR NOW IT APPEARS AREAS NORTH
WILL REMAIN DRY. GFS INDICATES WET BULBS DROPPING BELOW ZERO THROUGH
THE COLUMN AROUND OR BEFORE THE ONSET OF PRECIP INDICATE ALL SNOW.
NAM SOUNDINGS ON THE OTHER HAND SHOW SLIGHTLY WARMER TEMPS ALOFT
HINTING AT THE POSSIBILITY FOR RAIN/SNOW MIX...THOUGH SREF P-TYPE
PROBABILITY INDICATES BETTER CHANCES FOR SNOW. COMING OFF HIGHS IN
THE UPPER 40S IN AREAS MOST LIKELY TO SEE PRECIP...AND OVERNIGHT
LOWS SOUTH OF 80 AT OR EVEN SLIGHTLY ABOVE FREEZING...THE LIKELIHOOD
OF ACCUMULATING SNOW IS LOW AND WOULD LIKELY BE CONFINED TO THE
GRASS. IN ADDITION...GIVEN THE MARGINAL SOUNDINGS...SNOW PRODUCTION
WOULD BE INEFFICIENT. WILL MAINTAIN RAIN/SNOW MIX IN THE FORECAST
FOR NOW GIVEN THE CURRENT UNCERTAINTY.
HIGH PRESSURE WILL THEN TRANSLATE ACROSS THE REGION OVER THE
REMAINDER OF THE WEEKEND RESULTING IN DRY WEATHER FROM SATURDAY
AFTERNOON ON. H85 THERMAL TROUGH WILL APPROACH THE REGION ON
SATURDAY...THOUGH SUBSIDENCE ALOFT SETTLING OVER THE UPPER MIDWEST
THROUGH THE DAY SATURDAY WILL RESULT IN DRYING AND WARMING OF THE
MID LEVELS WHICH WILL HELP MODULATE THE COLDER AIRMASS MOVING
OVERHEAD. WITH AFTERNOON SUNSHINE...EXPECT AREAS AWAY FROM THE LAKE
TO RISE INTO THE MID TO UPPER 40S AGAIN...WITH A FEW 50S MAINLY
SOUTH OF I-80. ALONG THE LAKE FRONT...A BREEZE OFF THE LAKE THROUGH
THE DAY WILL KEEP TEMPERATURES MUCH COOLER...IN THE MID 30S. THE
SURFACE RIDGE AXIS WILL PASS OVERHEAD SATURDAY NIGHT...AND SOUTHERLY
FLOW WILL RAMP UP THROUGH THE DAY SUNDAY AHEAD OF OUR NEXT AREA OF
LOW PRESSURE STARTING TO TAKE SHAPE OVER THE PLAINS. STRONG WARM
ADVECTION IS EXPECTED THROUGH THE DAY SUNDAY WHICH WILL RESULT IN
H85 TEMPS RISING TO AROUND 10C BY SUNDAY EVENING. SOUTHERLY WINDS
MAY TAKE ON A SLIGHT WESTERLY COMPONENT BY SUNDAY AFTERNOON...IN THE
190-200 DIRECTION...WHICH WITH THE INCREASING WINDS SHOULD HELP
STAVE OFF ANY LAKE BREEZE/LAKE COOLING SUNDAY. NAM/GFS SOUNDINGS
SHOW LOW TO MID 20 KT GUSTS POSSIBLE BY SUNDAY AFTERNOON.
TEMPERATURES SHOULD RISE TO AROUND 60 RIGHT UP TO THE LAKE FRONT
SUNDAY AFTERNOON.
MONDAY...
AFOREMENTIONED SURFACE LOW PROGGED TO LIFT FROM THE MID MISSOURI
VALLEY EARLY MONDAY INTO MN/WI MONDAY EVENING. LATEST GUIDANCE IN
DECENT AGREEMENT ON THE LOCAL AREA GETTING FULL WARM SECTOR ON
MONDAY. LEANED TOWARD WARMER SIDE OF GUIDANCE MONDAY WITH A BLEND OF
BIAS CORRECTED GEM AND ECMWF. THIS RESULTS IN LOW TO MID 60S AREA
WIDE MONDAY AFTERNOON...AND WITH A MODERATE-STRONG SSW WIND...DO NOT
ANTICIPATE ANY COOLING ALONG THE LAKE. A 60-70KT LOW LEVEL JET
FOCUSES STRONG CONVERGENCE ACROSS THE MID MISSOURI VALLEY SUNDAY
NIGHT...THEN AT 40-50 KT REFOCUSES TO OUR NORTH MONDAY
EVENING/NIGHT. ACROSS NORTHERN ILLINOIS IN THE WARM SECTOR...
INSTABILITY IS PRETTY MEAGER WITH A STRONG CAP IN PLACE...THOUGH
SOME DYNAMIC COOLING ASSOCIATED WITH NEGATIVELY TILTED H5 WAVE AND
EXIT REGION OF UPPER JET MAY RESULT IN SOME SCATTERED CONVECTION.
ALL-IN-ALL THOUGH...GIVEN THE UNFAVORABLE TIMING OF THE FRONT
OVERNIGHT...NOT TOO IMPRESSED WITH PRECIP CHANCES MONDAY AND TRIMMED
POPS FOR THIS PERIOD.
TUESDAY THROUGH THURSDAY...
PRETTY LOW CONFIDENCE IN THE DETAILS AT THIS POINT...BUT TUESDAY
THROUGH THURSDAY SHOULD BE AN ACTIVE PERIOD WITH A SERIES OF
DISTURBANCES MOVING ACROSS THE REGION. THERE REMAINS SIGNIFICANT
DIFFERENCES AT THIS POINT BETWEEN MODELS WITH RESPECT TO THE LOW
TRACK WHICH WILL DETERMINE TEMPS AND PRECIP TYPE. GFS INDICATES A
FASTER MORE SOUTHERLY LOW WHILE THE ECMWF HINTS AT A WARMER SOLUTION
WITH A DEEPER LOW THAT TRACKS FARTHER NORTH. FOR NOW...STAYED CLOSE
TO A CONSENSUS BLEND.
TUBELESS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* VARIABLE NORTH-NORTHWEST TO NORTH-NORTHEAST WINDS...TURNING
NORTHEAST MID/LATE AFTERNOON.
* CIGS AROUND 020 SCATTERING LATE THIS AFTERNOON OR EARLY THIS
EVENING.
* ANOTHER PERIOD OF LOWER CIGS POSSIBLE LATE TONIGHT/SATURDAY
MORNING...MVFR POSSIBLE.
MDB
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE CONTINUES TO MOVE NORTHEAST ACROSS EASTERN ONTARIO
AND WESTERN QUEBEC LEAVING NORTHERLY WINDS IN ITS WAKE ACROSS THE
LOCAL AREA. WINDS WILL LIKELY BE VARIABLE BETWEEN NORTHWEST AND
NORTH INLAND OF THE LAKE THROUGH THE AFTERNOON THEN TURN LIGHT
NORTHEASTERLY THIS EVENING. AREAS CLOSER TO THE LAKE INCLUDING
ORD/MDW/GYY WILL LIKELY FLUCTUATE BETWEEN NORTHWEST AND NORTH-
NORTHEAST WITH GYY BECOMING STEADY NORTHEAST EARLY THIS AFTERNOON.
NOT AS CONFIDENCE IN IF STEADIER NORTHEAST WINDS WILL SET UP AT
ORD/MDW DURING THE AFTERNOON OT HOLD OFF UNTIL EVENING. CLOUD
COVER REMAINS ABUNDANT...WHICH MAY ALSO SLOW THE TIMING OF A SHIFT
TO NORTHEAST WINDS/LAKE BREEZE. WITH THE SOUTHWARD ADVANCE OF
CLEARING ACROSS SOUTHERN WISCONSIN SLOWING WILL KEEP MVFR CIGS
ACROSS THE TERMINALS THROUGH THE AFTERNOON THEN SCATTER/CLEAR
EARLY THIS EVENING.
AN UPPER TROUGH CROSSES THE AREA LATER TONIGHT BRINGING LOWERING
CIGS. CIGS SHOULD REMAIN LOWER END MVFR BUT A PERIOD OF MVFR IS
POSSIBLE. THERE IS ALSO A MINIMAL THREAT FOR SOME LIGHT SNOW OR
JUST FLURRIES OVERNIGHT BUT WILL KEEP THE TAF DRY. NORTHEAST WINDS
WILL PERSIST THROUGH SATURDAY WITH SKIES SCATTERING/CLEARING
DURING THE MID/LATE MORNING HOURS.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WIND TRENDS...LOW-MEDIUM CONFIDENCE IN
TIMING OF SHIFT TO STEADIER NORTHEAST.
* HIGH CONFIDENCE IN MVFR CIGS THROUGH MID AFTERNOON...THEN LOW-
MEDIUM CONFIDENCE IN TIMING OF SCATTERING BEYOND THAT.
* MEDIUM CONFIDENCE THAT CIGS WILL REMAIN VFR OVERNIGHT/SATURDAY
MORNING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. NORTHEAST WINDS TURNING SOUTHEAST.
SUNDAY...VFR. SOUTH WINDS.
MONDAY...CHANCE OF SHRA/TSRA LATE. MODERATE-STRONG SOUTH WINDS.
TUESDAY...VFR PROBABLE. WEST WINDS.
WEDNESDAY...CHANCE OF RAIN AND IFR/MVFR CIGS. NORTHEAST WINDS.
THURSDAY...CHANCE OF RAIN OR SNOW AND IFR/MVFR. NORTHEAST WINDS.
LENNING
&&
.MARINE...
307 AM CDT
A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THIS MORNING
ACROSS LOWER MICHIGAN AND LAKE HURON. NORTHWEST TO NORTH GALES
WILL EASE QUICKLY THIS MORNING AS THE LOW PULLS AWAY AND THE
PRESSURE GRADIENT WEAKENS. A RIDGE WILL CROSS THE LAKE ON SATURDAY
BEFORE THE NEXT LOW PRESSURE SYSTEM STARTS TO APPROACH OUT OF THE
CENTRAL PLAINS. ALTHOUGH THIS LOW DOES NOT REACH THE LAKE UNTIL
TUESDAY...SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL DEVELOP BY
EARLY SUNDAY. A PERIOD OF GALES IS AGAIN POSSIBLE LATE MONDAY
INTO TUESDAY...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE
LAKE...AS THE LOW MOVES THROUGH.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 2 PM FRIDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1231 PM CDT Fri Mar 28 2014
.DISCUSSION...
ISSUED 1014 AM CDT Fri Mar 28 2014
Updated forecast to lower highs a few degrees and increase cloud
cover mainly across central/northern CWA. 10 AM visible satellite
imagery showed a strip of clearing north of the Ohio River
extending into the far SE CWA, while farther north a thick blanket
of stratus/SC stretched back through most of MO/IA and southern
WI. HRRR and RAP RH trends in the 950-900 MB level suggest the
clearing over the far SE will slowly shift north towards I-72 by
late afternoon as southerly winds strengthen in that layer. This
clearing will be brief however as mid clouds ahead of next wave
developing in the Plains overspread the region later this
afternoon and evening. Brisk NW winds this morning to ease through
afternoon as low pressure pushes east of the Great Lakes and MSLP
gradient relaxes.
&&
.AVIATION...
ISSUED 1231 PM CDT Fri Mar 28 2014
Extensive area of MVFR SC blankets all terminals this afternoon.
Latest model trends show this will take until late afternoon and
early evening to erode from the south and have shifted TAFS
towards that timing. The next weather disturbance will quickly
shift northeast from the Plains this evening spreading mid level
clouds across the area. All models (except NAM being farthest
north outlier) bring precip as far north as the I-72 corridor
after midnight through 10-12Z. Thermal profiles are near rain/snow
threshold and with surface temps above freezing have -RASN in
forecast with slight visibility reduction. Questionable if
farthest north sites will receive any precip so have VCSH for BMI
and kept PIA dry. Ceilings are expected to be near MVFR during
this precip event. Initially light north winds this afternoon will
veer around to the northeast and increase in speed overnight
through Sat morning up to 10-15 kts in response to low pressure
tracking south of the Ohio Valley.
25
&&
.PREV DISCUSSION...
ISSUED 313 AM CDT Fri Mar 28 2014
SHORT TERM...Today through Sunday
Main forecast challenge in the immediate short-term will be timing
the departure of low clouds today. 07z/2am surface analysis shows
low pressure over southern Lake Michigan with cold front trailing
southward along the I-57 corridor. Extensive area of wrap-around
cloud cover is noted on IR satellite imagery blanketing Iowa,
northern Missouri, and western Illinois. With low-level flow
becoming northwesterly, these clouds will spill across central
Illinois early this morning. All model guidance suggests an
overcast start to the day, but how quickly the clouds clear out
remains in question. NAM forecast soundings indicate clouds will
mix out/dissipate between 15z and 18z. Latest HRRR hints at this
as well, although the process may be slower than the NAM
advertises. Given subsidence behind departing upper short-wave and
late March sun working on the low clouds, think skies will
temporarily clear around midday into the early afternoon. After
that, high clouds will quickly begin to increase ahead of the next
approaching system by mid to late afternoon.
Next forecast concern revolves around low pressure expected to
track from Texas into the Tennessee River Valley tonight. Models
have been having difficulty resolving how far north associated
precip will spread. 00z Mar 28 suite is still in disagreement,
with the GFS being the most aggressive in bringing precip furthest
north. Since GFS is often too bullish with light QPF events and
airmass will be drying today, think the NAM has a more realistic
handle on the situation. As such, will keep locations along and
north of a Jacksonville to Bloomington line dry tonight. Best rain
chances will be focused along/south of I-70 in closer proximity to
the low track, with POPs steadily decreasing further northwest.
Despite overnight lows in the middle to upper 30s, NAM forecast
soundings remain warm enough for rain. If colder/further north GFS
verifies, a rain/snow mix may be possible along the northern
fringe of the precip area. Will leave mention of mix out of the
forecast due to skepticism about the GFS QPF field.
After a few lingering showers across the far E/SE KILX CWA
Saturday morning, dry and warmer weather will be the rule this
weekend. As southerly winds develop, high temperatures will climb
into the lower to middle 60s by Sunday.
LONG TERM...Monday through Thursday
Models are still advertising cold frontal passage late Monday,
although amount of available moisture appears to be quite limited.
GFS surface dewpoints are initially around 40 degrees Monday
morning and only climb to the upper 40s to near 50 by late
afternoon. Despite decent upper dynamics associated with vigorous
short-wave, lack of deep moisture return from the Gulf will limit
convective potential. As a result, will only carry low chance for
showers on Monday. Slightly cooler and drier weather will settle
into the region behind the departing front on Tuesday before
another system comes into the picture by mid-week. There are still
some key timing differences with this feature: however, all models
agree that it will have much more moisture to work with. With
short-wave crossing the Rockies into the central CONUS, surface
low pressure is expected to track from eastern Colorado on
Tuesday to the southern Great Lakes by Thursday night. Initial
surge of WAA clouds/precip will arrive Tuesday night into
Wednesday: however, with central Illinois remaining in the cool
sector, very little thunder is expected. Once warm front lifts
northward into the area and low pressure approaches from the
southwest, showers and thunderstorms will become more prevalent
Wednesday night into Thursday.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
324 PM CDT FRI MAR 28 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 237 PM CDT FRI MAR 28 2014
STRATUS HAS BEEN STUBBORN TO LEAVE AND WHILE CEILINGS WILL RAISE
THROUGH THE EVENING THE LOW STRATUS SHOULD LINGER UNTIL AN UPPER
LEVEL SHORTWAVE SWEEPS EAST THROUGH TONIGHT AND GRADUALLY SCOURS OUT
MOISTURE. SATELLITE IS SHOWING SOME HIGHER LEVEL CLOUDS WITH THIS
FEATURE SO WHILE THE LOW STRATUS CONDITIONS WILL IMPROVE WE SHOULD
STILL KEEP AN OVERCAST CONDITION THROUGH THE EVENING WITH GRADUAL
IMPROVEMENT AFT 08-09Z. CURRENT RADAR IS SHOWING SOME RETURNS OUT
WEST BUT OBSERVATIONS CONFIRM THAT THE PRECIP IS NOT REACHING THE
GROUND. THE NAM12 KEEPS CENTRAL IOWA DRY TONIGHT BUT THE RAP13 DOES
PRINT OUT SOME QPF IN THE BROAD ASCENT AHEAD OF THE SHORTWAVE
PASSING. IT CURRENTLY HAS A GOOD HANDLE ON WHERE PRECIP IS ON THE
RADAR BUT IS OVERDOING IT BECAUSE THERE ARE NO SITES REPORTING
PRECIP SO THE RAP IS LIKELY A BIT OVERDONE. EITHER WAY BOTH MODEL
PRETTY MUCH WIPE ANY PRECIP OUT BEFORE IT MOVES MUCH INTO CENTRAL
IOWA....WITH ONE EXCEPTION...THE RAP DOES DRIBBLE SOME SMALL QPF HERE
AND THERE ACROSS CENTRAL IOWA THROUGH 06Z. FOR NOW I HAVE OPTED TO
KEEP THE FORECAST AREA DRY AND ADVISE THE EVENING SHIFT THAT A
COUPLE OF THE RETURNS ON RADAR...IF THEY HOLD AS THEY COME ACROSS
CENTRAL IOWA...COULD PRODUCE A SPRINKLE OF FLURRY.
TEMPS ARE THE NEXT ISSUE. THE LOW CLOUD COVER REALLY HAMMERED HIGHS
TODAY WITH MOST LOCATIONS IN THE MID TO UPPER 30S. THE STRATUS
EARLY ON WILL KEEP TEMPS UP AND I DO NOT EXPECT MUCH DIURNAL CHANGE
THROUGH THE EVENING. HOWEVER I DO EXPECT CLOUDS TO CLEAR FROM WEST
OR NORTHWEST TO EAST/SOUTHEAST OVERNIGHT. THIS WILL ALLOW A QUICKER
FALL TO TEMPS OVERNIGHT EXCEPT FOR THE FAR SOUTHEAST WHERE CLOUDS
WILL LINGER THE LONGEST. I EITHER WENT ABOVE GUIDANCE OR STAYED ON
THE WARMER SIDE OF IT BASING THAT ON CLOUDS HANGING AROUND LONGER.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 237 PM CDT FRI MAR 28 2014
THE TRANSITION FROM WINTER TO SPRING APPEARS TO BE WELL UNDERWAY.
THE PATTERN FOR THE NEXT WEEK LOOKS SEASONABLY ACTIVE WITH
MULTIPLE SHORTWAVES MOVING THROUGH IN WESTERLY PROGRESSIVE FLOW.
SATURDAY AND SUNDAY...GENERAL SUBSIDENCE BEHIND TONIGHT/S
SHORTWAVE WILL PREVAIL ON SATURDAY. SURFACE RIDGE MOVES EAST BY
EVENING. TEMPERATURES WILL RECOVER NICELY REACHING THE 50S IN MOST
LOCATIONS. RIDGING ALOFT SATURDAY NIGHT AND SUNDAY AHEAD OF A
POTENT SHORTWAVE SHOULD RESULT IN THE WARMEST TEMPERATURES SINCE
LAST FALL ON SUNDAY. THE WARM UP HAS BEEN FORECAST FOR DAYS AND
KEPT WARM TEMPERATURES GOING. BASED WINDS ON MIXED LAYER WINDS OR
SLIGHTLY LESS SINCE IT IS A WARM ADVECTION SITUATION.
MONDAY AND TUESDAY...USED 12Z ECMWF/GFS TO BASE FORECAST. 12Z NAM
APPEARED TO BE AN OUTLIER. THE ECMWF/GFS WERE SLOWER AND STRONGER
WITH THE SHORTWAVE ENERGY EMERGING FROM THE CENTRAL ROCKIES AT 12Z
MONDAY. BOTH SOLUTIONS BRING A NEGATIVELY TILTED SHORTWAVE THROUGH
CENTRAL IOWA ON MONDAY. THE ECMWF IS NORTH OF THE GFS SURFACE LOW
POSITION AT 00Z TUESDAY. CENTRAL IOWA WILL BE IN THE WARM SECTOR
WITH A COLD FRONT MOVING INTO THE WESTERN COUNTIES BY AFTERNOON
AND A SURFACE LOW EITHER IN NORTHWEST IOWA OR NEARBY. LOOKING AT
THE MODEL SOUNDINGS...THE LIMITING FACTOR FOR SEVERE WEATHER WILL
BE TIMING CONSIDERATIONS AND THE AMOUNT OF LOW-LEVEL MOISTURE
TRANSPORTED INTO IOWA AHEAD OF THE SYSTEM. IF THINGS COME TOGETHER
IT COULD GET INTERESTING MONDAY EVENING IN CENTRAL IOWA. SHEAR
PARAMETERS ARE VERY FAVORABLE. FINALLY...THE WEATHER PATTERN IS ON
PAR FOR THE TIME OF YEAR. THERE HAVE BEEN NUMEROUS SEVERE WEATHER
EVENTS IN CENTRAL IOWA BETWEEN MARCH 31ST AND APRIL 12TH OVER THE
YEARS.
COLD AIR WILL MOVE BACK IN THE WAKE OF THIS SYSTEM AND TUESDAY
LOOKS DRY BUT COOLER AND BREEZY.
WEDNESDAY THROUGH FRIDAY...ACTIVE PATTERN CONTINUES. MODELS ARE IN
POOR AGREEMENT WITH THE DETAILS AT THIS RANGE. HOWEVER...IT
APPEARS LIKELY THAT ANOTHER STORM SYSTEM WILL IMPACT THE MIDWEST
LATE IN THE WEEK. CONFIDENCE CONCERNING THE FORECAST DETAILS ARE
BELOW AVERAGE AT THAT POINT.
&&
.AVIATION...28/18Z
ISSUED AT 1246 PM CDT FRI MAR 28 2014
STRATUS WILL BE HANGING IN LONGER THAN PREVIOUSLY THOUGHT. I HAVE
KEPT AN IFR FORECAST GOING INTO THE EVENING...UNTIL THE UPPER LEVEL
SHORTWAVE PASSES AND SCOURS OUT SOME OF THE MOISTURE. CIGS WILL
GRADUALLY IMPROVE THROUGH THE OVERNIGHT HOURS ALTHOUGH IF CLOUDS
BREAK WE COULD SEE SOME MVFR FOG CONDITIONS FOR A COUPLE HOURS. AFT
14-15Z JUST SOME SCT CLOUDS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FAB
LONG TERM...JOHNSON
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS TOPEKA KS
556 PM CDT Fri Mar 28 2014
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Saturday)
Issued at 342 PM CDT FRI MAR 28 2014
Center of upper wave moving across South Dakota today with another
wave crossing Texas. Enough forcing and moisture for scattered very
light precip across much of Kansas today. Light winds and little
insolation keeping temps in the middle 40s at 20Z. Visible satellite
showing additional precip attempting to form in southwest Nebraska
and northwest Kansas in steep low level lapse rates just ahead of
the trough axis.
Should see back edge of precip exiting east central Kansas by sunset
with clearing already occurring in central portions of the state.
Any convective activity to the west would likely not arrive until
after sunset, given its diurnal nature am not expecting much if
anything to survive this far east. Clear skies and light winds in a
reinforcing low level ridge overnight, but rather dry boundary layer
should keep fog in check. Upper heights rise Saturday with surface
ridge passing through in the daytime keeps winds on the lighter side
again with modest warm air advection as high clouds slowly increase.
Highs in the low to mid 60s remain on track. RH values dipping into
the middle 20s will likely keep elevated fire danger conditions
going for the west.
.LONG TERM...(Saturday Night through Friday)
Issued at 342 PM CDT FRI MAR 28 2014
Early on is the concern for winds on Sunday as 850 MB winds increase
to 40 to 45 kts by the afternoon hours. Forecast soundings show
mixing up to 825 MB with temperatures in the mid to upper 70s.
Afternoon relative humidity expected near or below 30 percent and
given the dry fuels expect high to very high fire danger on Sunday.
Also winds will increase to near 25 mph with gusts as high as 40 mph
not out of the question. Most likely will need a wind advisory for
Sunday.
Sunday night elevated showers and thunderstorms are possible across
the CWA after midnight when the low level jet increases ahead of an
approaching upper trough moving out of the Rockies. The trough moves
northeast from southwest Kansas into south central Nebraska during
the morning hours on Monday with a dry slot moving across eastern
Kansas. Wrap around precipitation is possible to the north of the
Nebraska border in the afternoon. A pacific cool front will move
across the CWA during the day on Monday. Will leave a dry forecast
for now, but this will need to be monitored.
Tuesday night increasing moisture and instability is forecast across
northern Kansas as the low level jet increases from the south. Good
moisture fetch from the gulf into the Southern and Central Plains.
Warm front sets up south of the CWA across southern Kansas with
isentropic lift increasing northward over the CWA especially after
midnight.
Wednesday looking like a busy day with potential for severe
thunderstorms across the CWA. Shear, instability and moisture coming
together along with the warm front sliding northward into the CWA in
the afternoon hours. Another Pacific front will move through
Thursday as the upper low moves across the Central Plains. Kept
chances of showers as instability shifts off to the east into the
Mid Mississippi Valley by evening. There is uncertainty in the track
of the upper low with the ECMWF further north and the GFS south
across Kansas. This will have an impact on both temperatures and
precipitation placement. Friday looking dry as the upper system is
well east. Temperatures for much of next week will average near or
below normal.
&&
.AVIATION...(For the 00Z TAFs through 00Z Saturday Evening)
Issued at 556 PM CDT FRI MAR 28 2014
With TOP reporting reduced VSBY for much of the day, am a little
concerned for the development of ground fog since the boundary
layer never really mixed out. RAP and NAM forecast soundings also
suggest there could be some shallow fog. At this time will mention
some MVFR VSBY at TOP overnight. MHK and FOE mixed out better
through the afternoon so think boundary layer moisture may be more
limited and fog potential is lower given some dry air advection
through the night. Otherwise conditions should be fine with
surface ridging over the area through the morning Saturday.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65
LONG TERM...53
AVIATION...Wolters
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
226 PM EDT FRI MAR 28 2014
.UPDATE...
ISSUED AT 210 PM EDT FRI MAR 28 2014
GRIDS WERE FRESHENED UP BASED ON THE LATEST OBSERVATION TRENDS.
SHOWER ACTIVITY IS NEXT TO NIL ACROSS THE REGION IN ADVANCE OF THE
COLD FRONT. THIS IS LIKELY DUE TO SOME MID LEVEL CAPPING AS SHORTWAVE
MID LEVEL RIDGING BETWEEN THE DEPARTING SHORTWAVE AND THE NEXT
SYSTEMS WORKS ACROSS THE OH VALLEY REGION. SHOWER ACTIVITY THIS
AFTERNOON SHOULD BE MINIMAL...IF ANY AT ALL ACROSS THE REGION. AT
THIS TIME...WE PLAN TO LET THE SLIGHT CHANCE POPS RIDE SINCE THE NAM
AND GFS AS WELL AS THE HRRR STILL HAVE SOME CONVECTION LATER THIS
AFTERNON AND INTO THE EVENING.
UPDATE ISSUED AT 1120 AM EDT FRI MAR 28 2014
THE PREFRONTAL CONVECTION HAS EXITED TO THE SOUTH AND EAST...ALTHOUGH
THE COLD FRONT IS ONLY MAKING SLOW SOUTHEAST PROGRESS AND IS NEAR OR
JUST WEST OF THE INTERSTATE 65 CORRIDOR. A MID LEVEL SHORTWAVE OVER
THE GREAT LAKES REGION IS EXITING TO THE NORTH AND EAST OF THE AREA.
A RELATIVE LULL IN ACTIVITY IS ANTICIPATED BETWEEN THIS DEPARTING
SHORTWAVE AND THE NEXT WAVE TO APPROACH THE AREA TONIGHT. THUS...POPS
HAVE BEEN LOWERED TO SLIGHT CHANCE FOR THE REMAINDER OF THE DAY INTO
THE EVENING. ALSO...HOURLY SKY...TEMPS AND DEWPOINTS HAVE BEEN FINE
TUNED TO REFLECT RECENT OBSERVATIONS AS WELL AS SATELLITE AND RADAR
IMAGERY.
UPDATE ISSUED AT 800 AM EDT FRI MAR 28 2014
THE THUNDERSTORMS WITH THE COLD FRONT ARE FADING OUT NOW SO HAVE
BACKED OFF OF THEM TO JUST AN ISOLATED MENTION IN THE GRIDS. HAVE
TIMED THE CORE OF THE PCPN THROUGH THE AREA FROM WEST TO EAST FROM 12
TO 15Z. ALSO...FINE TUNED TEMPS AND DEWPOINTS THROUGH THE NEXT
SEVERAL HOURS WITH THIS UPDATE PER THE LATEST OBS AND TRENDS. THESE
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 335 AM EDT FRI MAR 28 2014
06Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING THROUGH THE
GREAT LAKES WITH A SHARP COLD FRONT ENTERING THE OHIO VALLEY. THIS
BOUNDARY IS SHOWING UP WELL ON RADAR AS A THIN LINE OF SHOWERS AND
THUNDERSTORMS DROPPING SOUTHEAST TOWARD KENTUCKY. SCATTERED TO
NUMEROUS SHOWERS ARE FOUND OUT AHEAD OF THIS LINE THROUGH CENTRAL
EASTERN KENTUCKY. THIS ADVANCE CONVECTION IS WORKING TO MOISTEN UP
THE VERY DRY AIR OVER EAST KENTUCKY AND THUS FAR NOT AMOUNTING TO TOO
MUCH ACCUMULATION. HAVE TIMED THE FRONT INTO EAST KENTUCKY AROUND 12Z
AND THROUGH BY 15Z...HIGHLIGHTING THIS TIME FRAME WITH THE HIGHEST
POPS AND BEST CHANCE FOR THUNDER. IN THE MEANTIME...GUSTY SHOWERS AND
SPRINKLES WILL CONTINUE OVER THE CWA. AHEAD OF THE FRONT THE
TEMPERATURES ARE REMAINING QUITE MILD WITH READINGS GENERALLY IN THE
LOW TO MID 50S. DEWPOINTS VARY FROM THE LOWER 40S IN THE WEST TO
AROUND 30 IN THE FAR EAST. OUTSIDE OF THE HIGHER GUSTS IN SHOWERS...
WINDS ARE RUNNING FROM THE SOUTH TO SOUTHWEST AT 10 TO 15 MPH WITH
GUSTS TO 25 MPH. HIGHER SUSTAINED SPEEDS AND GUSTS TO 35 MPH ARE
STILL POSSIBLE WITH THE SHOWERS...PARTICULARLY OVER THE NORTHERN AND
WESTERN PARTS OF THE CWA.
THE MODELS ARE IN DECENT AGREEMENT ALOFT WITH THE SHALLOW TROUGH
PASSING THROUGH THE GREAT LAKES THIS MORNING. THIS IS FOLLOWED BY
SOUTHWEST FLOW AND AN AMPLIFYING TROUGH OVER THE CENTRAL PLAINS INTO
TONIGHT. THIS NEXT TROUGH IMPRESSIVELY DEEPENS AS IT MOVES INTO THE
AREA AND RIGHT OVER KENTUCKY ON SATURDAY. THIS FEATURE NEARLY CLOSES
OFF AND IS SURPRISINGLY SIMILAR IN THE MODELS AT 00Z SUNDAY WITH THE
GEM AND GFS THE STRONGEST. THE ECMWF AND NAM ARE A BIT WEAKER...BUT
THE PATTERNS AND TIMING ALL MATCH UP WELL. GIVEN THIS...HAVE GONE
WITH A GENERAL MODEL BLEND AND FOLLOW SPECIFICS FROM THE NAM12 AND
GFS.
SENSIBLE WEATHER WILL FEATURE A VERY ACTIVE AND CHANGEABLE SHORT TERM
PORTION OF THE FORECAST. FOR STARTERS...SHOWERS AND A POSSIBLE
THUNDERSTORM...WILL CROSS THROUGH ALL OF EAST KENTUCKY THIS MORNING
AS A COLD FRONT MOVES THROUGH. LOOK FOR CLOUDY SKIES TO REMAIN ALONG
WITH SOME LINGERING SHOWERS FOR THE AFTERNOON...ESPECIALLY OVER THE
SOUTHEAST. THIS FRONT WILL SETTLE JUST SOUTH OF THE AREA THIS EVENING
AND QUICKLY REACTIVATE OVER THE WEST BY MIDNIGHT. THIS NEXT WAVE...
DRIVEN BY THE APPROACHING AND STRENGTHENING MID LEVEL TROUGH...WILL
CONSOLIDATE OVER THE TENNESSEE VALLEY BY EARLY SATURDAY MORNING AND
RETURN SHOWERS AND POSSIBLE THUNDERSTORMS TO EAST KENTUCKY. THE
CENTER OF THIS LOW WILL PASS THROUGH FAR SOUTHEAST KENTUCKY DURING
THE DAY AND START TO PULL IN COLDER AIR FROM THE NORTH. THERE IS
STRONG MODEL SUPPORT FOR THE COLUMN OF AIR COOLING ENOUGH BY LATE
AFTERNOON IN THE NORTHWEST PARTS OF THE CWA TO RESULT IN A CHANGEOVER
TO SNOW. SFC TEMPERATURES WILL STAY UP WELL ABOVE FREEZING THROUGH
00Z SUNDAY SO ANY ACCUMULATIONS WILL HOLD OFF UNTIL LATER THAT NIGHT.
FOR TEMPERATURES...WINDS...AND DEW POINTS USED THE BC/CONSSHORT AS A
STARTING POINT THROUGH THE EARLY OVERNIGHT HOURS OF SATURDAY. AFTER
THAT USED AN ADJUSTED VERSION OF THE RAW NAM FOR TEMPS AND THE
BC/CONSALL FOR TD AND WINDS. AS FOR POPS...ENDED UP RATHER WET AND IN
LINE WITH THE MOS GUIDANCE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 AM EDT FRI MAR 28 2014
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A
PROGRESSIVE AND ACTIVE PATTERN IN PLACE AS A STRONG SHORTWAVE IS
MOVING THROUGH THE OH AND TN VALLEY AT THIS TIME AND MOVES UP THE
EAST COAST BY SUNDAY NIGHT. AFTER THAT...MID LEVEL RIDGING CAUSES A
FAST MOVING SHORT WAVE TO MOVE NORTHEAST INTO THE GREAT LAKES REGION
AND INTO NEW ENGLAND BY TUESDAY. AFTER THIS...A BROAD CLOSED LOW
CROSSES THE FRONT RANGE AND INTO THE CENTRAL PLAINS BY TUESDAY NIGHT
AND INTO WEDNESDAY. THIS WAVE DEEPENS AS IT THEN MOVES INTO THE MS
RIVER VALLEY ON THURSDAY. THE GFS AND EURO SEEM TO BE IN DECENT
AGREEMENT WITH THIS PATTERN...ESPECIALLY WITH THE LOW TOWARDS THE
END OF THE EXTENDED WHICH COULD BE A SIGNIFICANT EVENT.
IN THE LOWER LEVELS FOR SATURDAY NIGHT...THE COLDER AIR FILTERING IN
BEHIND THE FRONT THAT PASSED THROUGH ON SATURDAY WILL MAKE INTO THE
AREA FAST ENOUGH FOR RAIN TO CHANGE TO SNOW. IN FACT...WITH THE
SMALL LAYER OF DRIER AIR AT THE SURFACE FOR SOME WET BULBING...THE
COLDER AIR NOT FAR OFF THE SURFACE...AND THE CONVECTIVE PROPERTIES
OF THE SHOWERS...WILL NOT BE SURPRISED TO SEE SNOW AT 35 DEGREES AT
THE SURFACE. WITH THE DEPTH OF THE MOIST LAYER AND THE OMEGA
AVAILABLE...HAVE ALSO PUT IN SOME ACCUMULATING SNOW IN THE FORECAST
WITH MAINLY THE BLUE GRASS AND THE HIGHER TERRAIN IN THE NORTH AND
EAST. THE FRONT MOVING THROUGH ON TUESDAY LOOKS TO DRY OUT AS IT
APPROACHES THE AREA. THE BEST DYNAMICS TAKE A FARTHER TRACK NORTH
AND HAVE LEFT SLIGHT CHANCE POPS NORTH OF THE FORECAST AREA.
HOWEVER...WILL NOT BE SURPRISED TO SEE SOME SPRINKLES POP UP TUESDAY
AFTERNOON. ANY HINT THAT THE DEVELOPING SHOWERS WILL NOT SHEAR OUT
AND SOME ADDITIONAL MOISTURE AVAILABLE...THE CHANCE IS THERE FOR SOME
SHOWERS AND AN ISOLATED THUNDERSTORM. THERE IS A GOOD BIT OF SURFACE
INSTABILITY TUESDAY AFTERNOON. FOR NOW...WILL KEEP THIS PERIOD DRY.
WITH MOST LIKELY A DRY PERIOD CONTINUING INTO WEDNESDAY...THE SET UP
TOWARDS THE END OF THE EXTENDED WILL CHANGE THIS DRY PATTERN.
SURFACE HIGH PRESSURE SETS UP OVER THE SOUTHEAST AND PROVIDING WARM
MOIST SOUTHERLY FLOW INTO THE OH VALLEY AHEAD OF THE NEXT
APPROACHING POTENT SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS INTO
THE AREA LATE WEDNESDAY AND THROUGH THE REST OF THE EXTENDED. THIS
SET UP WILL BE ONE TO WATCH FOR HOW IT DEVELOPS. A LOT CAN CHANGE IN
THE MODELS BETWEEN NOW AND THEN BUT THE POTENTIAL FOR SEVERE WEATHER
IS PRESENT WITH THIS SET UP.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 210 PM EDT FRI MAR 28 2014
A COLD FRONT HAS BEGUN TO STALL ACROSS THE OH VALLEY REGION AS THE
FIRST SFC LOW AND ASSOCIATED MID LEVEL DISTURBANCE DEPART AND SFC LOW
PRESSURE BEGINS TO ORGANIZE OVER THE SOUTHERN PLAINS. THIS NEXT SFC
LOW WILL TRACK ACROSS THE AREA LATE TONIGHT AND INTO SAT. SOME LOCATIONS
SHOULD IMPROVE TO VFR FOR A WHILE OVER THE FIRST 6 TO 9 HOURS OF THE
PERIOD IN BETWEEN SYSTEMS. CLOUDS WILL REMAIN...JUST ABOVE THE MVFR
VFR BREAK IN LOCATIONS THAT DO IMPROVE TO VFR. THIS NEXT LOW WILL
BRING RENEWED CHANCES FOR SHOWERS AND POSSIBLY ISOLATED TSRA AS WELL
AS ANOTHER LOWERING OF CONDITIONS BACK TO MVFR BETWEEN 8Z AND 14Z.
THIS WILL BE AFTER
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...JP
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1229 PM CDT FRI MAR 28 2014
.AVIATION UPDATE...REGARDING 18Z TAF ISSUANCE. MVFR AND IFR
CEILINGS CAN BE EXPECTED TODAY AS A MOIST SOUTHERLY FLOW
CONTINUES. A FEW SHOWERS WILL BE POSSIBLE DURING THE
AFTERNOON...WITH INCREASING SHOWERS ALONG WITH THUNDERSTORMS INCOMING
FROM THE WEST GOING INTO THE EVENING HOURS. THIS ALONG AND AHEAD
OF OUR NEXT FRONTAL PASSAGE. CURRENTLY CARRYING PREVAILING FOR
THUNDER AT AEX WHERE LIFT WILL BE SOMEWHAT STRONGER FOR
CONVECTION...AND TEMPO GROUPS AT OUR SOUTHERN TERMINALS. COULD NOT
RULE OUT SOME STRONG OR EVEN SEVERE THUNDERSTORMS...AGAIN WITH
BEST CHANCES AT AEX. OTHERWISE...RAINS WILL TAPER OFF WITH THE
FRONTAL PASSAGE...BUT EXPECTING IFR CEILINGS AND SOME BR TO HOLD
POST-FRONTAL AS DRIER AIR SURFACE AIR WILL BE SLOW TO FILTER IN.
EXPECTING CLEARING SKIES WEST TO EAST POST-SUNRISE SATURDAY.
&&
MARCOTTE
&&
.PREV DISCUSSION... /ISSUED 1030 AM CDT FRI MAR 28 2014/
UPDATE...
ADJUSTED THE POPS DOWNWARD A LITTLE FOR MOST PLACES FOR THE
REMAINDER OF THE MORNING AND AFTERNOON. LOOKS LIKE CAP SHOULD HOLD
ENOUGH THAT JUST WIDELY SCATTERED SHOWERS...MAINLY LIGHT...UNDER
THE CAP WILL BE ALL THAT CAN GET GOING. AFTER 21Z...4 PM...UPPER
LEVEL SUPPORT WILL BE MOVING TOWARD THE REGION...THIS MAY ALLOW
FOR SOME STRONGER SHOWERS AND STORMS TO DEVELOP OVER WESTERN
PORTIONS OF SOUTHEAST TEXAS...TYLER AND HARDIN COUNTIES...SO HAVE
KEPT HIGHER POPS IN THIS AREA...WITH THE MENTION OF POSSIBLE
SEVERE. ALSO...VISIBILITIES HAVE BEEN IMPROVING OVER THE MARINE
AREAS A LITTLE QUICKER THAN PREVIOUSLY EXPECTED...WITH
VISIBILITIES AT CAMERON UP TO 2 MILES...AND PLATFORMS SOUTHEAST OF
GALVESTON AND SOUTH OF MARSH ISLAND ALSO AROUND 2 MILES. EXPECT A
LITTLE MORE IMPROVEMENT OVER THE NEXT COUPLE OF HOURS AS WARMING
PROVIDES ENOUGH INSTABILITY TO HELP BRIEFLY LIFT THE FOG OR MAKE
IT MORE PATCHY IN NATURE. THEREFORE...WILL HAVE THE MARINE DENSE
FOG ADVISORY EXPIRE AT NOON TIME.
RUA
PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 28 2014/
AVIATION...LIFR AND IFR CEILINGS WILL CONTINUE THROUGH THE MOST
OF THE MORNING ALONG WITH REDUCED VIS IN BR AND -RA. CONDITIONS
WILL GRADUALLY IMPROVE FROM LATE MORNING INTO THE AFTERNOON,
HOWEVER ADDITIONAL RAIN AND THUNDERSTORMS WILL DEVELOP DURING THE
AFTERNOON AND EVENING. THIS WILL REDUCE CEILINGS AND VIS ONCE
AGAIN. RAIN CHANCES WILL DECREASE PAST MIDNIGHT WITH FG DEVELOPING
TOWARD SAT MORNING. WINDS WILL BE SE TO SW TODAY AT 12 KTS OR LESS
OUTSIDE OF STORMS. WINDS MAY BECOME GUSTY AND ERRATIC IN OR NEAR STORMS.
PREV DISCUSSION... /ISSUED 531 AM CDT FRI MAR 28 2014/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE OVER MAINLY EAST CENTRAL
LOUISIANA THIS MORNING...GENERALLY WITHIN AREA OF ENHANCED LOW
LEVEL MSTR INFLUX/CONVERGENCE AND BENEATH DIVERGENCE ALOFT
ENHANCED BY COUPLED JET STRUCTURE BETWEEN SUB-TROPICAL JET AND JET
MAX ASSOCIATED WITH SHORTWAVE TROF LIFTING THROUGH THE UPPER
MIDWEST. UPSTREAM WATER VAPOR IMAGERY CONTINUES TO DEPICT AN
ACTIVE SUB-TROPICAL JET...WITH ANOTHER SHORTWAVE TROF JUST PASSING
EAST OF THE FOUR CORNERS.
THE ONGOING ACTIVITY IS EXPECTED TO GENERALLY SHIFT EASTWARD THIS
MORNING...WITH A GENERAL LULL IN ACTIVITY EXPECTED UNTIL THE APPROACH
OF THIS UPSTREAM SHORTWAVE LATER THIS AFTERNOON. HRRR AND OTHER
MESOSCALE MODELS INDICATE CONVECTION INITIATING OVER CENTRAL/EAST
TEXAS EARLY TO MID AFTERNOON...WITH SUBSEQUENT DOWNSTREAM
MOVEMENT/DEVELOPMENT ACROSS THE FORECAST AREA THIS EVENING. THE MARINE
LAYER MAY PROVE DETRIMENTAL OVER THE COASTAL COUNTIES/PARISHES...BUT
INSTABILITY IS OVERALL PROGGED TO BE GREATER THAN IT WAS ON
THURSDAY...WITH THE ADDITION OF SFC FEATURES...LIKE THE APPROACHING
CDFNT...TO BETTER FOCUS DEVELOPMENT. SPC HAS ENTIRE AREA OUTLINE
IN A SLIGHT RISK...WITH LARGE HAIL/DAMAGING WINDS THE PRIMARY
HAZARDS. LOW LEVEL SHEAR/HELICITY...WHILE NOT PRECLUDING
TORNADOES...SUGGESTS THE RISK IS SUBORDINATE TO THE OTHER TWO.
DECREASING WINDS HAVE SUBSEQUENTLY RESULTED IN DECREASING VSBYS
OVER THE COASTAL WATERS AS WELL AS INLAND. SUFFICIENT TURBULENT
MIXING WILL LIKELY PREVENT INLAND VSBYS FROM REACHING DENSE FOG
CRITERIA...BUT REFER TO THE MARINE DISCUSSION BELOW FOR THE COASTAL
WATERS.
THE CDFNT IS PROGGED TO SWEEP THROUGH THE REGION LATE TONIGHT...WITH
COOLER AND DRIER AIR GIVING WAY TO A PLEASANT WEEKEND. RAIN
CHANCES LOOK TO RETURN FOR THE MID TO LATTER PART OF THE WEEK AMID
THE RETURN OF A WAA REGIME AND ACTIVE SUB-TROPICAL JET.
13
MARINE...
SOUTH WINDS HAVE STEADILY DECREASED EARLY THIS MORNING...WHICH IS
PERMITTING A SLOWER TRANSPORT OF MOISTURE LADEN AIR OVER
RELATIVELY COOLER SHELF WATERS. THE RESULT HAS BEEN A STEADY
DECREASE IN VISIBILITIES SEEN AT OFFSHORE AND COASTAL REPORTING
SITES. WITH THIS PATTERN EXPECTED TO REMAIN IN PLACE UNTIL A COLD
FRONT PASSES EARLY SATURDAY...CONDITIONS WILL CONTINUE TO SUPPORT
MARINE FOG FORMATION. A MARINE FOG ADVISORY HAS BEEN ISSUED...AND
MAY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7 PM
CDT. GOOD CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED UNTIL
THIS COLD FRONT MOVES THROUGH THE REGION LATE FRIDAY NIGHT INTO
EARLY SATURDAY. A MODEST OFFSHORE FLOW IS EXPECTED OVER THE
WEEKEND IN THE WAKE OF THE FRONT...WITH SOUTHERLY WINDS RETURNING
TO START THE WORK WEEK.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 62 76 49 72 50 / 60 10 10 10 10
KBPT 62 78 52 73 53 / 50 10 10 10 10
KAEX 57 72 44 73 46 / 60 10 10 10 10
KLFT 63 74 49 73 49 / 60 10 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1211 PM CDT FRI MAR 28 2014
.UPDATE...
ISSUED AT 1116 AM CDT FRI MAR 28 2014
MADE SOME ADJUSTMENTS TO THE FORECAST TODAY...ADDING IN A CHANCE
OF SPRINKLES ACROSS SOUTHEAST NEBRASKA. VERY SUBTLE DISTURBANCE ON
WATER VAPOR MOVING OUT OF NORTH CENTRAL KANSAS COULD GENERATE SOME
PRECIP ALONG THE NE/KS BORDER REGION THIS MORNING. ALSO DROPPED
TEMPS THERE JUST A BIT DUE TO INCREASED CLOUD COVER. COULD ALSO BE
A FLURRY IN EXTREME NORTHEAST NEBRASKA...BUT BELIEVE ECHOES ARE
PROBABLY ALOFT THERE. HOWEVER...SLIGHT PRECIP CHANCES TUCKED IN
WITH THE UPPER TROUGH...CURRENTLY MOVING THROUGH CENTRAL SOUTH
DAKOTA...COULD MOVE INTO NORTHEAST NEBRASKA LATER THIS AFTERNOON
AND LINGER FOR AN HOUR OR TWO EARLY THIS EVENING...MORE IN LINE
WITH LATEST RAP SUGGESTION. ALSO DROPPED TEMPS IN NORTHEAST
NEBRASKA DUE TO THE POOR MIXING AND CLOUD COVER.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 304 AM CDT FRI MAR 28 2014
THE SHORTWAVE TROUGH THAT BROUGHT THE WEATHER TO THE AREA ON
THURSDAY IS MOVING THROUGH THE MID MS RIVER VALLEY EARLY THIS
MORNING. ON THE HEELS OF THIS SYSTEM EARLY MORNING WATER VAPOR
IMAGERY INDICATED ANOTHER SHORTWAVE TROUGH OVER THE HIGH PLAINS.
REGIONAL RADAR MOSAIC INDICATES THAT SCT LIGHT PRECIP ASSOCIATED
WITH THIS SYSTEM EXTENDS FROM SW SD INTO WRN KS. MODELS ARE
CONSISTENT IN TAKING THIS SHORTWAVE TROUGH EAST TODAY ACROSS THE
FA. LARGE-SCALE FORCING FOR ASCENT DOES INCREASE THROUGH THE DAY
AS THE BETTER 500 TO 300 MB Q-VECTOR CONVERGENCES MOVES THROUGH.
THE SYSTEM WILL BE MOVING INTO A DRY ATMOSPHERE WITH INCREASING
STATIC STABILITY THOUGH...WHICH IS EXPECTED TO SIGNIFICANTLY LIMIT
THE IMPACT TO THE SENSIBLE WEATHER FOR EASTERN NEB/WESTERN IA. WE
WILL SEE PERIODS OF CLOUDS TODAY /INITIALLY A WAA BAND THIS
MORNING FOLLOWED BY SOME POSSIBLE SUNSHINE AND MORE CLOUDS
ASSOCIATED WITH THE DPVA LATE THIS AFTERNOON/. WE HAVE CONFINED
THE AREAL EXTENT OF THE PRECIP TO OUR FAR NORTHWEST COUNTIES AND
WE WOULDN`T BE SURPRISED IF OUR ENTIRE AREA STAYS DRY TODAY. WITH
SOME PARTIAL SUNSHINE EXPECTED TODAY WE DID INCREASE HIGHS A TOUCH
ALONG AND SOUTH OF I80.
THE SURFACE RIDGE IN THE WAKE OF THIS SHORTWAVE TROUGH WILL CROSS
THE FA TONIGHT AND WITH SKIES CLEARING...WINDS BECOMING LIGHT AND
VARIABLE...AND RECENT RAIN WE LEFT IN THE FOG MENTION FOR FRI
NIGHT. RETURN FLOW WILL START LATE FRIDAY NIGHT INTO THE DAY ON
SATURDAY WITH SOUTHERLY WINDS INCREASING. WITH FULL SUNSHINE AND A
DRY GROUND WE SHOULD SEE DECENT MIXING WITH HIGHS IN THE 60S IN
ERN NEB AND UPPER 50S WRN IA. AS THE NEXT SHORTWAVE TROUGH MOVES
INTO THE ROCKIES SAT NIGHT SURFACE CYCLOGENESIS WILL INCREASE OVER
THE HIGH PLAINS LEADING TO A BREEZY AND MILD NIGHT FOR THE FA.
WITH MILD OVERNIGHT TEMPS ON SAT NIGHT THIS SHOULD SET THE STAGE
FOR A WARM AND WINDY SUN. MODELS INDICATE MID LEVEL LAPSE RATES OF
7.5 TO 8.5 C/KM ON SAT NIGHT AND HINT AT SOME MOISTURE IN THIS
LAYER AS WELL. THIS COULD LEAD TO SOME ACCAS SAT NIGHT INTO
SUNDAY BUT ATTM DOESN`T APPEAR THAT THIS WOULD NEGATIVELY AFFECT
HIGHS ON SUNDAY WITH 70S LIKELY SOUTH OF THE WARM FRONT AND AHEAD
OF THE COLD FRONT.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 304 AM CDT FRI MAR 28 2014
THE SHORTWAVE TROUGH IN THE SHORT TERM WILL EJECT NEWD ON SUNDAY
NIGHT WITH A SURFACE LOW CROSSING NEB OVERNIGHT. THE MODELS ARE
VERY CONSISTENT IN DEVELOPING A STRONG LOW-LEVEL JET ON SUNDAY
NIGHT ACROSS KS INTO NEB/IA. THE NAM HAS MUCH HIGHER H85 DEWPOINTS
AND APPEARS TO BE AN OUTLIER COMPARED TO THE EC/GFS. THE NAM/SREF
DEVELOPS SOME CONVECTIVE PRECIP...BUT POINT FORECAST SOUNDINGS
FROM THE NAM/SREF ARE STRONGLY CAPPED ON SUNDAY NIGHT EVEN WITH
THE HIGHER MOISTURE PROFILE. WE MAY SEE A FEW SHOWERS ABOVE THE
CAP OVER THE EASTERN 2/3RD OF THE FA AND WILL MAINTAIN SOME SCHC
POPS FOR THIS POSSIBILITY. THE SURFACE COLD FRONT WILL BE MOVING
THROUGH THE FA ON MONDAY WITH THE DEFORMATION ZONE MOVING ACROSS
SD/MN. SOME OF THIS MAY CLIP NE NEB AND WILL CONT WITH SOME CHC
POPS THERE DURING THE DAY.
THE PERIOD MONDAY NIGHT THROUGH TUES LOOKS QUIET AND DRY BEFORE
THE NEXT SHORTWAVE TROUGH MOVES INTO THE CENTRAL PLAINS. THE
EC/GFS HAVE STRONG DIFFERENCES IN THE TIMING AND TRACK OF THIS
SYSTEM...BUT CHC POPS FOR SOME RA APPEAR WARRANTED DURING THIS
PERIOD. WE WILL INCLUDE SOME CHC OF RA/SN IN THE NW DURING THE
OVERNIGHT PERIODS. OTHERWISE BELOW NORMAL TEMPERATURES ARE
EXPECTED FOR THE EXTENDED PERIOD OF THE FORECAST.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1209 PM CDT FRI MAR 28 2014
MVFR CEILINGS AT KOMA WERE BEGINNING TO MOVE BACK EAST BASED ON
RECENT SATELLITE IMAGERY AND WILL PROBABLY GO BACK TO VFR BY 20Z
AT THAT LOCATION. OTHERWISE...VFR CONDITIONS PREVAIL THROUGH THE
PERIOD WITH LIGHT WINDS GENERALLY LESS THAN 7 KNOTS. WINDS DO
BECOME SOUTH ON SATURDAY...AND COULD APPROACH 12 KNOTS AT KOFK BY
16Z...BUT NOT UNTIL AFTER THE END OF THE TAF PERIOD AT BOTH
KLNK/KOMA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...BOUSTEAD
LONG TERM...BOUSTEAD
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1121 AM CDT FRI MAR 28 2014
.UPDATE...
ISSUED AT 1116 AM CDT FRI MAR 28 2014
MADE SOME ADJUSTMENTS TO THE FORECAST TODAY...ADDING IN A CHANCE
OF SPRINKLES ACROSS SOUTHEAST NEBRASKA. VERY SUBTLE DISTURBANCE ON
WATER VAPOR MOVING OUT OF NORTH CENTRAL KANSAS COULD GENERATE SOME
PRECIP ALONG THE NE/KS BORDER REGION THIS MORNING. ALSO DROPPED
TEMPS THERE JUST A BIT DUE TO INCREASED CLOUD COVER. COULD ALSO BE
A FLURRY IN EXTREME NORTHEAST NEBRASKA...BUT BELIEVE ECHOES ARE
PROBABLY ALOFT THERE. HOWEVER...SLIGHT PRECIP CHANCES TUCKED IN
WITH THE UPPER TROUGH...CURRENTLY MOVING THROUGH CENTRAL SOUTH
DAKOTA...COULD MOVE INTO NORTHEAST NEBRASKA LATER THIS AFTERNOON
AND LINGER FOR AN HOUR OR TWO EARLY THIS EVENING...MORE IN LINE
WITH LATEST RAP SUGGESTION. ALSO DROPPED TEMPS IN NORTHEAST
NEBRASKA DUE TO THE POOR MIXING AND CLOUD COVER.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 304 AM CDT FRI MAR 28 2014
THE SHORTWAVE TROUGH THAT BROUGHT THE WEATHER TO THE AREA ON
THURSDAY IS MOVING THROUGH THE MID MS RIVER VALLEY EARLY THIS
MORNING. ON THE HEELS OF THIS SYSTEM EARLY MORNING WATER VAPOR
IMAGERY INDICATED ANOTHER SHORTWAVE TROUGH OVER THE HIGH PLAINS.
REGIONAL RADAR MOSAIC INDICATES THAT SCT LIGHT PRECIP ASSOCIATED
WITH THIS SYSTEM EXTENDS FROM SW SD INTO WRN KS. MODELS ARE
CONSISTENT IN TAKING THIS SHORTWAVE TROUGH EAST TODAY ACROSS THE
FA. LARGE-SCALE FORCING FOR ASCENT DOES INCREASE THROUGH THE DAY
AS THE BETTER 500 TO 300 MB Q-VECTOR CONVERGENCES MOVES THROUGH.
THE SYSTEM WILL BE MOVING INTO A DRY ATMOSPHERE WITH INCREASING
STATIC STABILITY THOUGH...WHICH IS EXPECTED TO SIGNIFICANTLY LIMIT
THE IMPACT TO THE SENSIBLE WEATHER FOR EASTERN NEB/WESTERN IA. WE
WILL SEE PERIODS OF CLOUDS TODAY /INITIALLY A WAA BAND THIS
MORNING FOLLOWED BY SOME POSSIBLE SUNSHINE AND MORE CLOUDS
ASSOCIATED WITH THE DPVA LATE THIS AFTERNOON/. WE HAVE CONFINED
THE AREAL EXTENT OF THE PRECIP TO OUR FAR NORTHWEST COUNTIES AND
WE WOULDN`T BE SURPRISED IF OUR ENTIRE AREA STAYS DRY TODAY. WITH
SOME PARTIAL SUNSHINE EXPECTED TODAY WE DID INCREASE HIGHS A TOUCH
ALONG AND SOUTH OF I80.
THE SURFACE RIDGE IN THE WAKE OF THIS SHORTWAVE TROUGH WILL CROSS
THE FA TONIGHT AND WITH SKIES CLEARING...WINDS BECOMING LIGHT AND
VARIABLE...AND RECENT RAIN WE LEFT IN THE FOG MENTION FOR FRI
NIGHT. RETURN FLOW WILL START LATE FRIDAY NIGHT INTO THE DAY ON
SATURDAY WITH SOUTHERLY WINDS INCREASING. WITH FULL SUNSHINE AND A
DRY GROUND WE SHOULD SEE DECENT MIXING WITH HIGHS IN THE 60S IN
ERN NEB AND UPPER 50S WRN IA. AS THE NEXT SHORTWAVE TROUGH MOVES
INTO THE ROCKIES SAT NIGHT SURFACE CYCLOGENESIS WILL INCREASE OVER
THE HIGH PLAINS LEADING TO A BREEZY AND MILD NIGHT FOR THE FA.
WITH MILD OVERNIGHT TEMPS ON SAT NIGHT THIS SHOULD SET THE STAGE
FOR A WARM AND WINDY SUN. MODELS INDICATE MID LEVEL LAPSE RATES OF
7.5 TO 8.5 C/KM ON SAT NIGHT AND HINT AT SOME MOISTURE IN THIS
LAYER AS WELL. THIS COULD LEAD TO SOME ACCAS SAT NIGHT INTO
SUNDAY BUT ATTM DOESN`T APPEAR THAT THIS WOULD NEGATIVELY AFFECT
HIGHS ON SUNDAY WITH 70S LIKELY SOUTH OF THE WARM FRONT AND AHEAD
OF THE COLD FRONT.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 304 AM CDT FRI MAR 28 2014
THE SHORTWAVE TROUGH IN THE SHORT TERM WILL EJECT NEWD ON SUNDAY
NIGHT WITH A SURFACE LOW CROSSING NEB OVERNIGHT. THE MODELS ARE
VERY CONSISTENT IN DEVELOPING A STRONG LOW-LEVEL JET ON SUNDAY
NIGHT ACROSS KS INTO NEB/IA. THE NAM HAS MUCH HIGHER H85 DEWPOINTS
AND APPEARS TO BE AN OUTLIER COMPARED TO THE EC/GFS. THE NAM/SREF
DEVELOPS SOME CONVECTIVE PRECIP...BUT POINT FORECAST SOUNDINGS
FROM THE NAM/SREF ARE STRONGLY CAPPED ON SUNDAY NIGHT EVEN WITH
THE HIGHER MOISTURE PROFILE. WE MAY SEE A FEW SHOWERS ABOVE THE
CAP OVER THE EASTERN 2/3RD OF THE FA AND WILL MAINTAIN SOME SCHC
POPS FOR THIS POSSIBILITY. THE SURFACE COLD FRONT WILL BE MOVING
THROUGH THE FA ON MONDAY WITH THE DEFORMATION ZONE MOVING ACROSS
SD/MN. SOME OF THIS MAY CLIP NE NEB AND WILL CONT WITH SOME CHC
POPS THERE DURING THE DAY.
THE PERIOD MONDAY NIGHT THROUGH TUES LOOKS QUIET AND DRY BEFORE
THE NEXT SHORTWAVE TROUGH MOVES INTO THE CENTRAL PLAINS. THE
EC/GFS HAVE STRONG DIFFERENCES IN THE TIMING AND TRACK OF THIS
SYSTEM...BUT CHC POPS FOR SOME RA APPEAR WARRANTED DURING THIS
PERIOD. WE WILL INCLUDE SOME CHC OF RA/SN IN THE NW DURING THE
OVERNIGHT PERIODS. OTHERWISE BELOW NORMAL TEMPERATURES ARE
EXPECTED FOR THE EXTENDED PERIOD OF THE FORECAST.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK...AND KOMA.)
ISSUED AT 607 AM CDT FRI MAR 28 2014
LIGHT AND VARIABLE WINDS ARE EXPECTED THROUGH THE TAF PERIOD. BANK
OF MVFR STRATUS IS PUSHING WESTWARD TOWARD KOMA...AND WILL LIKELY
IMPACT THE TAF SITE FOR MUCH OF THE MORNING...WITH VFR CONDITIONS
EXPECTED AFTER IT CLEARS AROUND MIDDAY AS MID-LEVEL CEILINGS
EVENTUALLY GIVE WAY TO CLEARING TONIGHT. AT KOFK...VFR CONDITIONS
ARE LIKELY THROUGH TODAY...WITH SOME PERIOD OF LOW-END VFR
CEILINGS POSSIBLE THIS AFTERNOON. AT KLNK...VFR CEILINGS ARE
EXPECTED TODAY...WITH CLEARING SKIES TONIGHT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...BOUSTEAD
LONG TERM...BOUSTEAD
AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
348 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A SLOW-MOVING COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT.
DEVELOPING LOW PRESSURE MOVING ACROSS TO THE NORTH WILL PULL THE FRONT
THROUGH THE AREA LATE SATURDAY INTO SATURDAY NIGHT. THE LOW WILL
CONTINUE DEEPENING AS IT MOVES TO THE NORTHEAST SUNDAY AND SUNDAY
NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE WEST THROUGH MONDAY.
THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY. ANOTHER COLD FRONT WILL
APPROACH THE AREA BY FRIDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 345 PM FRIDAY...LOW-LEVEL MOISTURE TRANSPORT AND
PRECIPITABLE WATER VALUES CONTINUE TO CREEP UP ACROSS THE CENTRAL
PART OF THE STATE AHEAD OF SLOW-MOVING COLD FRONT IN THE TENNESSEE
VALLEY. RADAR SHOWING SOME LIGHT SHOWERS GRADUALLY MOVING INTO THE
COASTAL PLAINS...WHICH IS WELL DEPICTED BY THE LATEST 4 KM NSSL
WRF AND RAP MODELS. THE ATMOSPHERE IS STABLE AND DO NOT EXPECT
THUNDER THROUGH MOST OF THE OVERNIGHT HOURS. HAVE TRENDED POPS
INTO THE LIKELY RANGE...MAINLY AFTER MIDNIGHT AS THE PRECIPITATION
INCREASES AND MOVES EAST. WITH THE INCREASED CLOUDS...PRECIP AND
SOUTHERLY WINDS...MINIMUM TEMPERATURES TONIGHT WILL BE VERY
MILD...REMAINING MAINLY IN THE UPPER 50S TO AROUND 60 DEGREES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
AS OF 345 PM FRIDAY...WIDESPREAD SHOWERS WILL COVER THE CWA ON
SATURDAY AND CONTINUE THE FORECAST OF CATEGORICAL POPS...WITH SOME
EMBEDDED THUNDERSTORMS. SPC CONTINUES TO HAVE OUR CWA IN A SLIGHT
RISK OF SEVERE THUNDERSTORMS FOR SATURDAY. EXPECT MORNING
CLOUDINESS AND SHOWERS TO LIMIT THE INSTABILITY DURING THE FIRST
HALF OF THE DAY...BUT WITH BETTER DIRECTIONAL SHEAR AND LI`S OF -2
TO -4 LATE IN THE DAY...THINK THE POTENTIAL FOR ANY SEVERE WEATHER
WILL BE BETTER...ESPECIALLY IN THE 20Z-02Z TIME FRAME. DAMAGING
WINDS GUSTS WILL BE THE MAIN THREAT AND GIVEN THE BACKED LOW-LEVEL
FLOW...CANNOT RULE OUT A BRIEF TORNADO. TEMPERATURES WILL WARM
INTO THE MID 60S OUTER BANKS TO MID 70S INLAND...DESPITE THE CLOUD
COVER...GIVEN GUSTY SOUTHERLY WINDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
AS OF 3 PM FRI...GFS/ECMWF IN RATHER GOOD AGREEMENT FOR MOST OF
THE LONG TERM. WIDESPREAD SHOWERS AND STORMS SATURDAY NIGHT WILL
SLOWLY TAPER OFF FROM THE WEST AFTER MIDNIGHT AS THE COLD FRONT
MOVES EAST. NO CHANGES TO POPS. FRONT WILL MOVE OFF THE COAST
SHORTLY AFTER 12Z SUNDAY. PLENTY OF WRAPAROUND MOISTURE ON SUNDAY
SO EXPECT CLOUDS AND SCATTERED SHOWERS TO CONTINUE THROUGH THE DAY
WITH THE BEST CHANCE ACROSS THE NORTHEAST COUNTIES. SHOWERS WILL
FINALLY END SUNDAY EVENING AS THE UPPER LOW AND DEEP MOISTURE MOVE
AWAY. UPPER LEVEL RIDGING WILL BE DOMINANT NEXT WEEK...WHILE AT
THE SURFACE HIGH PRESSURE OVER THE SOUTHEAST MONDAY SHIFTS EAST
AND REMAINS OFF THE COAST THROUGH THE END OF THE WEEK...MAKING FOR
A PERIOD OF DRY AND WARM WEATHER FOR THE AREA. THE NEXT CHANCE OF
RAIN COMES WITH THE NEXT FRONT APPROACHING ON FRIDAY.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM /TONIGHT AND SATURDAY/...
AS OF 115 PM FRIDAY...VFR CONDITIONS WILL CONTINUE THROUGH THE
AFTERNOON WITH SUB-VFR FORECASTED THIS EVENING THROUGH TOMORROW. A
POTENT LOW PRESSURE SYSTEM WILL BE APPROACHING THE REGION FROM THE
WEST. THEREFORE...EXPECT CLOUDS TO INCREASE/LOW THROUGH THE LATE
AFTERNOON/EVENING HOURS. GUSTY SOUTHERLY FLOW WILL CONTINUE FOR
THE NEXT COUPLE OF HOURS BUT SUBSIDE AS THE SURFACE HEATING
DIMINISHES. RAIN SHOULD ARRIVE THIS EVENING THROUGH THE OVERNIGHT
HOURS WITH VSBYS LOWERING IN RESPONSE. ANTICIPATE MAINLY MVFR AND
SOME PATCHY IFR CIGS/VSBYS THROUGH THE OVERNIGHT HOURS INTO
SATURDAY MORNING. SSE WINDS AROUND 5-10KTS EXPECTED SATURDAY.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 3 PM FRI...GFS/ECMWF IN RATHER GOOD AGREEMENT FOR MOST OF
THE LONG TERM. WIDESPREAD SHOWERS AND STORMS SATURDAY NIGHT WILL
SLOWLY TAPER OFF FROM THE WEST AFTER MIDNIGHT AS THE COLD FRONT
MOVES EAST. NO CHANGES TO POPS. FRONT WILL MOVE OFF THE COAST
SHORTLY AFTER 12Z SUNDAY. PLENTY OF WRAPAROUND MOISTURE ON SUNDAY
SO EXPECT CLOUDS AND SCATTERED SHOWERS TO CONTINUE THROUGH THE DAY
WITH THE BEST CHANCE ACROSS THE NORTHEAST COUNTIES. SHOWERS WILL
FINALLY END SUNDAY EVENING AS THE UPPER LOW AND DEEP MOISTURE MOVE
AWAY. UPPER LEVEL RIDGING WILL BE DOMINANT NEXT WEEK...WHILE AT
THE SURFACE HIGH PRESSURE OVER THE SOUTHEAST MONDAY SHIFTS EAST
AND REMAINS OFF THE COAST THROUGH THE END OF THE WEEK...MAKING FOR
A PERIOD OF DRY AND WARM WEATHER FOR THE AREA. THE NEXT CHANCE OF
RAIN COMES WITH THE NEXT FRONT APPROACHING ON FRIDAY.
&&
.MARINE...
SHORT TERM /TONIGHT AND SATURDAY/...
AS OF 345 PM FRIDAY...HAVE EXTENDED THE SMALL CRAFT ADVISORY SOUTH
OF OREGON INLET UNTIL 12Z ON SATURDAY MORNING. WINDS ARE RAMPING
UP WITH GUSTS TO 20 KNOTS AT DUCK PIER...AND 25 KNOTS AT DIAMOND
BUOY. SEAS CONTINUE TO HOVER AROUND 6 FEET AT DIAMOND SHOALS.
EXPECT GUSTY SOUTHERLY WINDS AT 15 TO 20 KNOTS...EXCEPT UP TO 25
KNOTS AT TIMES OVER THE WATERS SOUTH OF OREGON INLET TONIGHT INTO
SATURDAY. PER LATEST SWAN/NWPS...SEAS AS HIGH AS 6 TO 7 FEET ARE
LIKELY...ESPECIALLY OVER THE CENTRAL WATERS TONIGHT AND EARLY
SATURDAY. THERE WILL BE A LULL IN WINDS/SEAS DURING LATE MORNING
INTO AFTERNOON SATURDAY. AN ADDITIONAL SMALL CRAFT ADVISORY WILL
LIKELY BE REQUIRED LATER TONIGHT FOR ALL WATERS BEHIND THE STRONG
FRONT SATURDAY NIGHT.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 3 PM FRI...GFS/ECMWF IN CLOSE AGREEMENT AND USED A BLEND.
VERY POOR BOATING CONDITIONS TO START OUT THE LONG TERM WITH ONLY
SLOW IMPROVEMENT THROUGH THE PERIOD. STRONG SMALL CRAFT WIND/SEA
CONDITIONS TO BEGIN WITH ALONG AND AHEAD OF THE COLD FRONT. THE
FRONT WILL MOVE OFF THE COAST AROUND 12Z SUNDAY. WINDS WILL VEER
FROM SOUTHWEST SATURDAY EVENING TO WEST SUNDAY MORNING THEN TO
NORTHWEST DURING THE DAY SUNDAY. SMALL CRAFT CONDITIONS WILL
GRADUALLY END FROM SOUTH TO NORTH SUNDAY NIGHT INTO MONDAY NIGHT.
HIGH PRESSURE OVER THE AREA MONDAY WILL SHIFT OFF THE SOUTHEAST
COAST TUESDAY AND WEDNESDAY WITH LIGHT WEST TO SOUTHWEST WINDS AND
SEAS AVERAGING 2-4 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR AMZ152-154-
156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...HSA
AVIATION...HSA/LEP
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
312 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE
INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM
AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF
SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD
FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER
OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY.
TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD
FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 300 PM FRIDAY...A LARGE MCS ALONG THE EASTERN GULF COAST
DOMINATES THE WEATHER PATTERN ACROSS THE SOUTHEASTERN U.S.
THE CONVECTIVE ELEMENTS OF THIS FEATURE ARE LARGELY LIMITED TO
SOUTHERN GEORGIA AND POINTS SOUTH...WITH AN EXPANSIVE BUT
DETERIORATING AREA OF LIGHT RAIN EXTENDING INTO NORTH GEORGIA AND
WESTERN SOUTH CAROLINA. THIS ACTIVITY SHOULD MOVE EASTWARD...
AFFECTING THE SC PEE DEE REGION EARLY THIS EVENING. OTHER GENERALLY
LIGHT SHOWERS DEVELOPING IN A WEAKLY UNSTABLE AIRMASS ACROSS THE
EASTERN CAROLINAS MAY CONTINUE INTO THE EVENING HOURS AS WELL AS
SMALL ELEVATED INSTABILITY IS MAINTAINED BY A SOUTHERLY FLOW ACROSS
THE GULF STREAM OFF THE GEORGIA AND SOUTH CAROLINA COAST.
THE UPPER LEVEL DISTURBANCE THAT HELPED KICK OFF THE GULF COAST MCS
WILL TURN NORTHEASTWARD TONIGHT...APPROACHING THE EASTERN CAROLINAS
LATE. WHILE A RENEWED BLOWUP OF CONVECTION IS NOT ANTICIPATED DUE TO
MEAGER INSTABILITY...A DIFLUENT UPPER LEVEL PATTERN AND AN
INCREASING NEGATIVE TILT TO THE TROUGH SHOULD ENHANCE RAIN/SHOWER
POTENTIAL OVERNIGHT ALL THE WAY DOWN TO THE COAST. WHILE I CAN`T
BRING MYSELF TO PUT 100 POPS IN THE FORECAST...80-90 PERCENT SEEMS
APPROPRIATE. PRECIPITABLE WATER VALUES SHOULD GROW TO 1.5 INCHES
AFTER MIDNIGHT.
IN TERMS OF MODEL SOLUTIONS...IT IS INTERESTING TO SEE HOW THE
MODELS HAVE HANDLED (OR MISHANDLED) TWO ASPECTS OF THE WEATHER
TODAY. ONE IS THE RELATIVELY LIGHT WINDS OVER THE COASTAL WATERS...
PARTICULARLY WHEN CONTRASTED TO THE RATHER BREEZY CONDITIONS
EXPERIENCED INLAND TODAY. MOST SYNOPTIC GUIDANCE (PARTICULARLY THE
GFS) HAS BEEN TOO STRONG WITH MARINE WIND SPEEDS ALL DAY. ALSO OF
NOTE IS THE PERSISTENT AREA OF LIGHT SHOWERS THAT MOVED INTO
GEORGETOWN THIS MORNING AND NOW COVERS BRUNSWICK COUNTY ACROSS
WHITEVILLE INTO LUMBERTON AND ELIZABETHTOWN. THIS ACTIVITY HAS BEEN
WELL-FORECAST BY THE HRRR AND NAM BUT NOT THE GFS. PREFERRED MODELS
TONIGHT INCLUDE THE HRRR IN THE VERY NEAR-TERM...THEN THE 12Z NAM
AND 12Z CANADIAN OVERNIGHT.
WITH SOUTHERLY WINDS AND CLOUDS CONTINUING OVERNIGHT LOWS SHOULD
ONLY FALL TO 59-60 INLAND WITH 57-58 NEAR THE BEACHES DUE TO WINDS
BLOWING IN OFF THE COLDER NEARSHORE WATERS. THE NAM MOS GUIDANCE IS
MUCH CLOSER TO MY IDEAS THAN THE GFS MOS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...THE MAIN CHALLENGE CONTINUES TO CENTER AROUND THE
COMPLEX STORM SYSTEM MOVING ACROSS THE SOUTHEAST. TIMING AND
INTENSITY OF RAINFALL AND ASSOCIATED THUNDERSTORMS REMAIN THE MAIN
ISSUES. I HAVE LEANED HEAVILY TOWARD THE GFS FOR THE LATEST UPDATES
TO THE SHORT TERM.
INITIALLY WE COULD HAVE A LARGE SWATH OF RAIN COMING OFF THE
ATLANTIC. AFTER THIS...THERE SHOULD BE A LULL IF YOU WILL WITH SOME
NVA IN THE WAKE OF THIS INITIAL FEATURE. THE MAIN SHORTWAVE FINALLY
GETS ORGANIZED AND MOVES OFF TO THE EAST/NORTHEAST SATURDAY
AFTERNOON WITH YET ANOTHER DEEP MOISTURE FEED FROM THE GULF OF
MEXICO WITH THE ASSOCIATED COLD FRONT. I HAVE INCREASED POPS FOR
LATE AFTERNOON ACROSS WESTERN AREAS AND THE EVENING HOURS FOR
COASTAL SITES. SEVERE PARAMETERS REMAIN MARGINAL AND CONTINUE TO
HINGE ON THE AMOUNT OF INSTABILITY THE IS ABLE TO DEVELOP.
LARGE DIFFERENCES IN TEMPERATURE GUIDANCE WITH THE NAM/MET NUMBERS
QUITE A BIT LOWER FOR DAYTIME HIGHS SATURDAY. I WOULD EXPECT ANY
BREAKS AND THERE SHOULD BE AT LEAST A FEW WILL ALLOW HIGHS TO JUMP
MORE TOWARD THE GFS/MAV NUMBERS. GUIDANCE TRENDS CLOSER SATURDAY
NIGHT AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE LONG TERM APPEARS TO OFFER RAIN-FREE
WEATHER. AS FAR AS TEMPERATURES GO DAYTIME HIGHS WILL AVERAGE
ABOUT A CATEGORY ABOVE CLIMO WHILST NIGHTTIME LOWS SHOULD BE EVEN
MILDER. HIGH PRESSURE SLIDES INTO FLORIDA ON MONDAY KEEPING LOCAL
WINDS RATHER LIGHT. MEANWHILE UPPER RIDGING BUILDS IN FROM THE
WEST. TUESDAY THROUGH WEDNESDAY WILL SHIFT THE HIGH SLIGHTLY
EASTWARD WHILE THE UPPER LEVEL WAVE FLATTENS. END RESULT WILL BE A
SLIGHT BOLSTERING OF THE WARM ADVECTION INTO THE REGION. UPPER
LEVEL AMPLITUDE WILL THEN INCREASE AGAIN THURSDAY INTO FRIDAY AS A
STORM SYSTEM MOVES OUT OF THE ROCKIES AND DEVELOPS INTO THE PLAINS
THURSDAY...MOVING INTO OHIO VALLEY COME FRIDAY.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...QUITE A BIT OF UNCERTAINTY WITH RESPECT TO THE TIMING OF
THE PRECIP...AS WELL AS CEILINGS OVERNIGHT. SOUTHERLY GRADIENT WILL
CAUSE WINDS TO GUSTS OVER 20 KTS AT TIMES...ESPECIALLY ALONG THE
COAST. SCATTERED SHOWERS WILL GIVE WAY TO MORE WIDESPREAD LIGHT TO
MODERATE RAIN THIS EVENING AS DEEP MOISTURE MOVES INTO THE REGION.
RAIN CHANCES WILL BE HIGHEST INLAND THIS EVENING...SPREADING TO THE
COAST A FEW HOURS LATER. CEILINGS ARE A BIT PROBLEMATIC...BUT WILL
GO FOR MVFR PREDOMINATELY WITH POCKETS OF IFR POSSIBLE. TIME HEIGHT
INDICATES THERE MAY BE A LULL IN THE PRECIP OF ABOUT 6-7 HOURS
THROUGH THE LATE OVERNIGHT HOURS. SATURDAY...MODERATE TO PERHAPS
HEAVY PRECIP SPREADING FROM WEST TO EAST. AN EMBEDDED THUNDERSTORM
CANNOT BE RULED OUT. IN FACT...IF WE GET SOME CAPE WE COULD HAVE A
FEW STRONGER STORMS IN THE AFTERNOON INTO EARLY EVENING. AGAIN
CEILINGS PREDOMINATELY MVFR.
EXTENDED OUTLOOK...BECOMING VFR SATURDAY NIGHT. SLIGHT CHANCE FOR
SHOWERS AND MVFR CEILINGS OVER THE NORTHERN PORTION OF THE CWA.
OTHERWISE VFR THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...SOUTH WINDS SHOULD CONTINUE OVERNIGHT AS THE
CAROLINAS ARE IN BETWEEN HIGH PRESSURE WELL OFFSHORE AND AN
APPROACHING COLD FRONT OVER THE MISSISSIPPI VALLEY. THE GFS MODEL
HAS BEEN TOO STRONG WITH WIND SPEEDS ALL DAY...BUT A COMBINATION OF
THE 12Z NAM AND CANADIAN MODELS SEEMS LIKE A GOOD FIT. SOUTH WINDS
10-15 KNOTS WILL RAISE A SHORT-PERIOD WIND WAVE...BUT STRONGER WINDS
OFFSHORE WILL CREATE LARGER WAVES THAT WILL PUSH WESTWARD INTO THE
COASTAL WATERS AS WELL. THE COMBINATION SHOULD CREATE 4-6 FOOT SEAS
WITH A 6 SECOND DOMINANT PERIOD...AND A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT FOR THIS. WAVES OF SHOWERS ARE EXPECTED ACROSS THE
WATERS...WITH HEAVIER ACTIVITY POSSIBLE OVERNIGHT. PM FRIDAY...
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...FAIRLY BRISK CONDITIONS WILL PREVAIL OVER THE
WATERS THROUGH THE PERIOD. FOR SATURDAY...A SOUTHERLY FLOW OF
15-20 KNOTS WILL BE IN PLACE AS LOW PRESSURE AND A COLD FRONT EDGE
CLOSER FROM THE WEST. THIS FRONT CROSSES THE WATERS BETWEEN 0600
AND 1200 UTC SUNDAY. WINDS WILL TURN FROM THE WEST AND INCREASE TO
20-25 KNOTS. WITH COLD AIR ADVECTION DEVELOPING SUNDAY...THE WINDS
WILL REMAIN ELEVATED BUT HOPEFULLY NOT THE LEVEL WE SAW EARLIER IN
THE WEEK TO GALE CRITERIA. BY MONDAY MORNING THERE IS A SLOW
DECREASE TO AROUND 15 KNOTS.
SIGNIFICANT SEAS WILL HOVER AROUND SMALL CRAFT CRITERIA AND I WILL
GO AHEAD AND EXTEND THE ADVISORY TO COVER SATURDAY AND SATURDAY
NIGHT. THE CHANGE IN FETCH SHOULD EVENTUALLY ALLOW THE ADVISORY TO
EXPIRE SUNDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...MONDAY STARTS WITH A MODERATE NW FLOW A RESULT
OF BOTH DEEPENING STORM MOVING UP THE MIDATLANTIC COAST AND HIGH
PRESSURE BUILDING IN FROM THE WEST. AS BOTH PROGRESS EASTWARD THE
LOCAL GRADIENT SHOULD REALLY EASE AS THE DAY WEARS ON AND BY MONDAY
NIGHT THERE MAY BE A LIGHT ENOUGH GRADIENT FOR A TRUE LIGHT AND
VARIABLE WIND. TUESDAY INTO WEDNESDAY THE HIGH TAKES A MORE OFFSHORE
POSITION GENERATING A LIGHT S TO SW FLOW LOCALLY. SEAS BUILD FROM
THEIR MINIMAL MONDAY NIGHT VALUES TO ABOUT 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SUNDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
128 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATER THIS AFTERNOON AND
THEN STALL TO THE NORTH TONIGHT. DEVELOPING LOW PRESSURE MOVING
ACROSS TO THE NORTH WILL PULL THE FRONT THROUGH THE AREA SATURDAY
NIGHT. THE LOW WILL CONTINUE DEEPENING AS IT MOVES TO THE
NORTHEAST SUNDAY AND SUNDAY NIGHT WITH HIGH PRESSURE BUILDING IN
FROM THE WEST THROUGH MONDAY. THE HIGH WILL MOVE SOUTH OF THE AREA
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM FRIDAY...HAVE AGAIN RAISED MAXIMUM TEMPERATURES A
COUPLE OF DEGREES AS MANY PLACES HAVE SOARED INTO THE LOWER 70S
AND MID 70S ARE NOT OUT OF THE QUESTION OVER THE NEXT COUPLE OF
HOURS. REMAINDER OF FORECAST REMAINS ON TRACK WITH SHOWERS
MOVING INTO THE FAR WESTERN COUNTIES AROUND 21Z OR SO BASED ON 4
KM NSSL WRF AND RAP MODELS. INSTABILITY LACKING AND DO NOT EXPECT
ANY THUNDER UNTIL SATURDAY AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS OF 430 AM FRIDAY...INCREASING MSTR AND SHRT WV ACTIVITY WILL
PRODUCE HIGHER THREAT OF SHOWERS TONIGHT...WITH TSTM MENTION LIMITED
TO COAST. GENERALLY CONTINUED PREVIOUS FCST OF POPS 50% COAST TO 70%
INLAND THIS EVENING...AND 60%-70% ALL ZONES OVERNIGHT. SRLY FLOW AND
CLOUD COVER WILL KEEP TEMPS MID 50S TO AROUND 60.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
AS OF 4 AM FRI...UNSETTLED PATTERN TO START THE LONG TERM PERIOD
THIS WEEKEND...THEN DRY AND SEASONABLY WARM FOR NEXT WEEK.
SHORT WAVE TROUGH ACROSS CENTRAL CONUS TODAY WILL AMPLIFY THROUGH
SATURDAY AND CLOSE OFF A MID LEVEL VORT SAT EVENING. MODELS COMING
IN BETTER AGREEMENT ON THIS SYNOPTIC SETUP AS WELL AS TIMING OF
THE FEATURES. THE NEUTRAL TILT CLOSED LOW WILL PROMOTE SFC LOW
DEVELOPMENT OVER CENTRAL NC SAT EVENING. AHEAD OF IT...INC SW LLJ
WILL FURTHER INC MOISTURE ADVECTION INTO E NC. BNDRY LAYER
STREAMLINES SUGGEST MOISTURE CONVERGENCE WILL BE MAXIMIZED SAT
EVENING...WITH BEST CHANCE OF WIDESPREAD RAIN SHOWERS OCCURRING
THEN. AHEAD OF THE SYSTEM...OCNL SHOWERS WITH EMBEDDED THUNDER
WILL OCCUR DURING THE DAY SAT. GFS ENSEMBLES CLUSTER FAIRLY WELL
WITH SFC LOW PLACEMENT ACROSS NC TO SOUTHERN VA BETWEEN 00Z AND
06Z SUN. THE 28/00Z ECM IS ALSO FAVORING THIS GENERAL POSITIONING
OF THE LOW. AS FAR AS SVR POTENTIAL IS CONCERNED...WIDESPREAD
CLOUDINESS AND RAIN SHOWER ACTIVITY WILL ACT TO LIMIT
DESTABILIZATION DURING THE DAY SAT...AND NOT EXPECTING MUCH IN WAY
OF ORGANIZED CONVECTION. NEVERTHELESS...BULK SHEAR WILL BE
SUFFICIENT FOR A FEW STORMS TO BECOME STRONG TO SEVERE WITH MAIN
THREAT ISOLATED DAMAGING WINDS. GFS AND NAM INDICATE SFC WINDS
BECOME BACKED SSE SAT EVENING AS H85-H90 FLOW REMAINS SW. THIS
WOULD PRODUCE FAIR AMOUNT OF LOW LEVEL TURNING/0-3KM HELICITY.
SHOULD ANY STORMS BECOME MORE ORGANIZED...CANNOT RULE OUT AN
ISOLATED TORNADO THREAT ESP LATE SAT AFTERNOON THROUGH EARLY
EVENING BEFORE LOW PULLS EAST AND SFC WINDS VEER SW TO W.
RAIN SHOWERS WILL DECREASE SAT NIGHT AS MOISTURE AND LIFT SHIFT
EAST WITH SFC EXITING SFC LOW. TEMPS WILL BE MILD MOST OF THE
NIGHT BEFORE WINDS BECOME W TO EVENTUALLY NW BY LATE SAT NIGHT AND
ALLOW TEMPS TO COOL TO THE LOW 50S. UPR LEVEL VORT WILL SLOWLY
MIGRATE EAST THROUGH THE DAY SUNDAY...AND HAVE CONTINUED TO WEIGHT
ECMWF SOLN WHICH WOULD KEEP WIDESPREAD LOW CLOUDS AND NUMEROUS
SHOWERS ACROSS E NC THROUGH THE FIRST HALF OF SUNDAY. HAVE INC
POPS TO LIKELY ACROSS THE NE ZONES...AND RETAINED HIGH CHANCE SCT
WORDING FURTHER S AND W. TEMPS WILL ALSO BE ON THE COOL SIDE WITH
THE WIDESPREAD CLOUDS AND SHOWER ACTIVITY WITH MOST AREAS IN THE
MID 50S...WITH SOME LOW 50S OBX.
DRAMATIC CLEARING OCCURS SUN NIGHT AS UPR LOW MOVES OUT TO SEA AND
TEMPS SEASONABLY COOL IN THE UPR 30S/LOW 40S FOR LOWS MON MORNING.
VERY DRY AIRMASS FOR MONDAY AS STRONG SUBSIDENCE AND BUILDING HIGH
PRES MOVE INTO THE AREA. 1000-850MB RH VALS PLUMMET TO THE 20%
RANGE ACCORDING TO THE ECM. WILL HAVE TO MONITOR FOR POTENTIAL
FIRE WEATHER CONCERNS. TEMPS WILL REBOUND TO THE MID/UPR 60S.
SPRAWLING SFC HIGH PRES WITH QUASI ZONAL FLOW WILL PRODUCE
PLEASANTLY DRY AND WARM CONDITIONS THROUGH THE MID WEEK TIME
PERIOD AND BEYOND WITH TEMPS WARMING TO THE MID/UPR 70S TO NEAR 80
BY THURSDAY. NEXT SYSTEM MAY AFFECT THE REGION FRIDAY INTO THE
WEEKEND.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH 18Z SATURDAY/...
AS OF 115 PM FRIDAY...VFR CONDITIONS WILL CONTINUE THROUGH THE
AFTERNOON WITH SUB-VFR FORECASTED THIS EVENING THROUGH TOMORROW.
A POTENT LOW PRESSURE SYSTEM WILL BE APPROACHING THE REGION FROM THE
WEST. THEREFORE...EXPECT CLOUDS TO INCREASE/LOW THROUGH THE LATE
AFTERNOON/EVENING HOURS. GUSTY SOUTHERLY FLOW WILL CONTINUE FOR THE
NEXT COUPLE OF HOURS BUT SUBSIDE AS THE SURFACE HEATING DIMINISHES.
RAIN SHOULD ARRIVE THIS EVENING THROUGH THE OVERNIGHT HOURS WITH
VSBYS LOWERING IN RESPONSE. ANTICIPATE MAINLY MVFR AND SOME PATCHY
IFR CIGS/VSBYS THROUGH THE OVERNIGHT HOURS INTO SATURDAY MORNING.
SSE WINDS AROUND 5-10KTS EXPECTED SATURDAY.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 4 AM FRI...MVFR OR LOWER IN NUMEROUS SHOWERS AND EMBEDDED
THUNDER SAT THROUGH SAT NIGHT. THE FRONT WILL MOVE OFF THE COAST
EARLY SUNDAY WITH SURFACE WINDS VEERING FROM SOUTH SOUTHWEST TO
NORTHWEST. SUB-VFR CONTINUES SUNDAY WITH SCATTERED TO NUMEROUS
SHOWERS IN LINGERING WRAPAROUND MOISTURE. VFR RETURNS ON SUN NIGHT
THROUGH MUCH OF NEXT WEEK AS LARGE HIGH PRES BUILDS IN BRINGING
EXCELLENT FLYING CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM FRIDAY...SOUTHERLY WINDS ARE GRADUALLY INCREASING TO 15
TO 20 KNOTS ACROSS MOST OF THE WATERS AND SEAS ARE BUILDING WITH 6
FOOT NOW REPORTED AT DIAMOND BUOY. OTHER THAN BUMPING UP THE
INITIAL WINDS...NO BIG CHANGES TO THE MARINE FORECAST AT THIS
TIME.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 4 AM FRI...POOR BOATING CONDITIONS SAT THROUGH THE FIRST PART
OF NEXT WEEK. SW WINDS WILL INC ONCE AGAIN DURING THE DAY SAT TO 25
KT OR HIGHER...ESP THE SOUTHERN/CENTRAL WATERS...AND SEAS WILL INC
TO 6 FT OR HIGHER. THE S TO SW WINDS WILL REMAIN STRONG THROUGH SAT
EVENING AHEAD OF LOW PRES AND A COLD FRONT. THE LOW WILL MOVE
OFFSHORE WITH THE COLD FRONT LATE SAT NIGHT AND WINDS TURNING TO THE
W AND THEN NW BY SUN MORNING. THE OFFSHORE LOW WILL SLOWLY PUSH AWAY
AND KEEP THE NW GRADIENT RATHER STRONG WITH SCA CONTINUING THROUGH
THE DAY SUNDAY. WINDS WILL FINALLY DIMINISH ON MONDAY THOUGH
LINGERING LARGE SWELL ABOVE 6 FT WILL CONTINUE ESP ACROSS
NORTHERN/CENTRAL WATERS. CONDITIONS IMPROVE MON NIGHT AS GRADIENT
RELAXES. WINDS WILL TURN SW BUT REMAIN LIGHT TUE THROUGH MID WEEK AS
LARGE HIGH PRES MOVES TO THE SOUTH OF THE AREA. PLEASANT BOATING
CONDITIONS EXPECTED DURING THIS TIME FRAME.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ152-154-
156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...TL
AVIATION...TL/LEP
MARINE...JBM/CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATER THIS AFTERNOON AND
THEN STALL TO THE NORTH TONIGHT. DEVELOPING LOW PRESSURE MOVING
ACROSS TO THE NORTH WILL PULL THE FRONT THROUGH THE AREA SATURDAY
NIGHT. THE LOW WILL CONTINUE DEEPENING AS IT MOVES TO THE
NORTHEAST SUNDAY AND SUNDAY NIGHT WITH HIGH PRESSURE BUILDING IN
FROM THE WEST THROUGH MONDAY. THE HIGH WILL MOVE SOUTH OF THE AREA
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM FRIDAY...HAVE AGAIN RAISED MAXIMUM TEMPERATURES A
COUPLE OF DEGREES AS MANY PLACES HAVE SOARED INTO THE LOWER 70S
AND MID 70S ARE NOT OUT OF THE QUESTION OVER THE NEXT COUPLE OF
HOURS. REMAINDER OF FORECAST REMAINS ON TRACK WITH SHOWERS
MOVING INTO THE FAR WESTERN COUNTIES AROUND 21Z OR SO BASED ON 4
KM NSSL WRF AND RAP MODELS. INSTABILITY LACKING AND DO NOT EXPECT
ANY THUNDER UNTIL SATURDAY AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS OF 430 AM FRIDAY...INCREASING MSTR AND SHRT WV ACTIVITY WILL
PRODUCE HIGHER THREAT OF SHOWERS TONIGHT...WITH TSTM MENTION LIMITED
TO COAST. GENERALLY CONTINUED PREVIOUS FCST OF POPS 50% COAST TO 70%
INLAND THIS EVENING...AND 60%-70% ALL ZONES OVERNIGHT. SRLY FLOW AND
CLOUD COVER WILL KEEP TEMPS MID 50S TO AROUND 60.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 4 AM FRI...UNSETTLED PATTERN TO START THE LONG TERM PERIOD
THIS WEEKEND...THEN DRY AND SEASONABLY WARM FOR NEXT WEEK.
SHORT WAVE TROUGH ACROSS CENTRAL CONUS TODAY WILL AMPLIFY THROUGH
SATURDAY AND CLOSE OFF A MID LEVEL VORT SAT EVENING. MODELS COMING
IN BETTER AGREEMENT ON THIS SYNOPTIC SETUP AS WELL AS TIMING OF
THE FEATURES. THE NEUTRAL TILT CLOSED LOW WILL PROMOTE SFC LOW
DEVELOPMENT OVER CENTRAL NC SAT EVENING. AHEAD OF IT...INC SW LLJ
WILL FURTHER INC MOISTURE ADVECTION INTO E NC. BNDRY LAYER
STREAMLINES SUGGEST MOISTURE CONVERGENCE WILL BE MAXIMIZED SAT
EVENING...WITH BEST CHANCE OF WIDESPREAD RAIN SHOWERS OCCURRING
THEN. AHEAD OF THE SYSTEM...OCNL SHOWERS WITH EMBEDDED THUNDER
WILL OCCUR DURING THE DAY SAT. GFS ENSEMBLES CLUSTER FAIRLY WELL
WITH SFC LOW PLACEMENT ACROSS NC TO SOUTHERN VA BETWEEN 00Z AND
06Z SUN. THE 28/00Z ECM IS ALSO FAVORING THIS GENERAL POSITIONING
OF THE LOW. AS FAR AS SVR POTENTIAL IS CONCERNED...WIDESPREAD
CLOUDINESS AND RAIN SHOWER ACTIVITY WILL ACT TO LIMIT
DESTABILIZATION DURING THE DAY SAT...AND NOT EXPECTING MUCH IN WAY
OF ORGANIZED CONVECTION. NEVERTHELESS...BULK SHEAR WILL BE
SUFFICIENT FOR A FEW STORMS TO BECOME STRONG TO SEVERE WITH MAIN
THREAT ISOLATED DAMAGING WINDS. GFS AND NAM INDICATE SFC WINDS
BECOME BACKED SSE SAT EVENING AS H85-H90 FLOW REMAINS SW. THIS
WOULD PRODUCE FAIR AMOUNT OF LOW LEVEL TURNING/0-3KM HELICITY.
SHOULD ANY STORMS BECOME MORE ORGANIZED...CANNOT RULE OUT AN
ISOLATED TORNADO THREAT ESP LATE SAT AFTERNOON THROUGH EARLY
EVENING BEFORE LOW PULLS EAST AND SFC WINDS VEER SW TO W.
RAIN SHOWERS WILL DECREASE SAT NIGHT AS MOISTURE AND LIFT SHIFT
EAST WITH SFC EXITING SFC LOW. TEMPS WILL BE MILD MOST OF THE
NIGHT BEFORE WINDS BECOME W TO EVENTUALLY NW BY LATE SAT NIGHT AND
ALLOW TEMPS TO COOL TO THE LOW 50S. UPR LEVEL VORT WILL SLOWLY
MIGRATE EAST THROUGH THE DAY SUNDAY...AND HAVE CONTINUED TO WEIGHT
ECMWF SOLN WHICH WOULD KEEP WIDESPREAD LOW CLOUDS AND NUMEROUS
SHOWERS ACROSS E NC THROUGH THE FIRST HALF OF SUNDAY. HAVE INC
POPS TO LIKELY ACROSS THE NE ZONES...AND RETAINED HIGH CHANCE SCT
WORDING FURTHER S AND W. TEMPS WILL ALSO BE ON THE COOL SIDE WITH
THE WIDESPREAD CLOUDS AND SHOWER ACTIVITY WITH MOST AREAS IN THE
MID 50S...WITH SOME LOW 50S OBX.
DRAMATIC CLEARING OCCURS SUN NIGHT AS UPR LOW MOVES OUT TO SEA AND
TEMPS SEASONABLY COOL IN THE UPR 30S/LOW 40S FOR LOWS MON MORNING.
VERY DRY AIRMASS FOR MONDAY AS STRONG SUBSIDENCE AND BUILDING HIGH
PRES MOVE INTO THE AREA. 1000-850MB RH VALS PLUMMET TO THE 20%
RANGE ACCORDING TO THE ECM. WILL HAVE TO MONITOR FOR POTENTIAL
FIRE WEATHER CONCERNS. TEMPS WILL REBOUND TO THE MID/UPR 60S.
SPRAWLING SFC HIGH PRES WITH QUASI ZONAL FLOW WILL PRODUCE
PLEASANTLY DRY AND WARM CONDITIONS THROUGH THE MID WEEK TIME
PERIOD AND BEYOND WITH TEMPS WARMING TO THE MID/UPR 70S TO NEAR 80
BY THURSDAY. NEXT SYSTEM MAY AFFECT THE REGION FRIDAY INTO THE
WEEKEND.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH 12Z SATURDAY/...
AS OF 730 AM FRIDAY...VFR CONDITIONS WILL PREVAIL INTO THIS
AFTN...THEN MVFR CIGS/VSBYS EXPECTED WITH SHRA DURING EVENING
LINGERING INTO OVERNIGHT. PRE-FRONTAL WARM SECTOR CONDITIONS
EXPECTED DURING THE TAF PERIOD WITH HIGH PRES OFFSHORE AND COLD
FRONT APPROACHING FROM W. SCT-BKN SCU WILL DEVELOP THROUGH MORNING
HOURS WITH INCREASING SRLY FLOW BUT CIGS EXPECTED TO REMAIN ABOVE 3K
FT. ISOLD SHRA PSBL INLAND LATE MORNING BUT BETTER COVERAGE LIKELY
DURING AFTN AND EVENING WITH CIGS AND VSBYS LOWERING TO MVFR. MOIST
LOW LVLS WILL RESULT IN CIGS LOWERING TO AROUND 1K FT FOR INLAND
SITES OVERNIGHT. SRLY WINDS WILL GUST UP TO 20-25 KT THIS AFTN.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 4 AM FRI...MVFR OR LOWER IN NUMEROUS SHOWERS AND EMBEDDED
THUNDER SAT THROUGH SAT NIGHT. THE FRONT WILL MOVE OFF THE COAST
EARLY SUNDAY WITH SURFACE WINDS VEERING FROM SOUTH SOUTHWEST TO
NORTHWEST. SUB-VFR CONTINUES SUNDAY WITH SCATTERED TO NUMEROUS
SHOWERS IN LINGERING WRAPAROUND MOISTURE. VFR RETURNS ON SUN NIGHT
THROUGH MUCH OF NEXT WEEK AS LARGE HIGH PRES BUILDS IN BRINGING
EXCELLENT FLYING CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM FRIDAY...SOUTHERLY WINDS ARE GRADUALLY INCREASING TO 15
TO 20 KNOTS ACROSS MOST OF THE WATERS AND SEAS ARE BUILDING WITH 6
FOOT NOW REPORTED AT DIAMOND BUOY. OTHER THAN BUMPING UP THE
INITIAL WINDS...NO BIG CHANGES TO THE MARINE FORECAST AT THIS
TIME.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 4 AM FRI...POOR BOATING CONDITIONS SAT THROUGH THE FIRST PART
OF NEXT WEEK. SW WINDS WILL INC ONCE AGAIN DURING THE DAY SAT TO 25
KT OR HIGHER...ESP THE SOUTHERN/CENTRAL WATERS...AND SEAS WILL INC
TO 6 FT OR HIGHER. THE S TO SW WINDS WILL REMAIN STRONG THROUGH SAT
EVENING AHEAD OF LOW PRES AND A COLD FRONT. THE LOW WILL MOVE
OFFSHORE WITH THE COLD FRONT LATE SAT NIGHT AND WINDS TURNING TO THE
W AND THEN NW BY SUN MORNING. THE OFFSHORE LOW WILL SLOWLY PUSH AWAY
AND KEEP THE NW GRADIENT RATHER STRONG WITH SCA CONTINUING THROUGH
THE DAY SUNDAY. WINDS WILL FINALLY DIMINISH ON MONDAY THOUGH
LINGERING LARGE SWELL ABOVE 6 FT WILL CONTINUE ESP ACROSS
NORTHERN/CENTRAL WATERS. CONDITIONS IMPROVE MON NIGHT AS GRADIENT
RELAXES. WINDS WILL TURN SW BUT REMAIN LIGHT TUE THROUGH MID WEEK AS
LARGE HIGH PRES MOVES TO THE SOUTH OF THE AREA. PLEASANT BOATING
CONDITIONS EXPECTED DURING THIS TIME FRAME.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ152-154-
156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...TL
AVIATION...JBM/TL
MARINE...JBM/CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1258 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE
INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM
AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF
SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD
FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER
OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY.
TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD
FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM FRIDAY...LIGHT SHOWERS HAVE DEVELOPED ALONG THE GENERAL
CORRIDOR INDICATED BY THE HRRR MODEL RUNS EARLIER THIS
MORNING...FROM GEORGETOWN THROUGH CONWAY...MARION AND DILLON. THIS
APPEARS TO BE THE PREFERRED AXIS FOR ADDITIONAL SHOWER DEVELOPMENT
THROUGH THE AFTERNOON...WITH LITTLE INDICATION SHOWER POTENTIAL WILL
RISE ACROSS THE WILMINGTON METRO AREA UNTIL PERHAPS NEAR SUNSET. A
LARGE AREA OF RAIN WITH EMBEDDED SHOWERY/CONVECTIVE ELEMENTS JUST
NOW CROSSING THE SAVANNAH RIVER INTO CENTRAL AND WESTERN SOUTH
CAROLINA WILL BEGIN TO IMPINGE ON OUR PEE DEE COUNTIES (FLORENCE AND
DARLINGTON) LATE THIS AFTERNOON...WITH SHOWER CHANCES INCREASING
RAPIDLY INTO THE EARLY EVENING HOURS. PREVIOUS DISCUSSION FROM 1030
AM FOLLOWS...
HIGH PRESSURE IS WELL OFFSHORE AND SOUTH WINDS ACROSS THE CAROLINAS
ARE BEING CAUSED BY RETURN FLOW BETWEEN THE HIGH AND A COLD FRONT
EXTENDING FROM THE GREAT LAKES INTO TEXAS. SUBTROPICAL MOISTURE
MOVING NORTHWARD IS SHOWING UP WITH CLIMBING SURFACE DEWPOINTS AND
PRECIPITABLE WATER VALUES...BOTH EXPECTED TO RISE SIGNIFICANTLY
TONIGHT.
AN AREA OF THICK MID AND HIGH CLOUDINESS ACROSS THE SOUTHEASTERN
STATES IS BEING PRODUCED BY A MESOSCALE CONVECTIVE SYSTEM ACROSS
MISSISSIPPI. SYNOPTIC MODELS ARE HAVING THEIR TROUBLE WITH THIS
SYSTEM...BUT THE LATEST FEW RUNS OF THE HRRR SHOW THE BULK OF THIS
CONVECTION DIMINISHING BEFORE ADVECTING THIS FAR EAST. INCREASING
MOISTURE SHOULD YIELD AN INCREASE IN SHOWER ACTIVITY LATE THIS
AFTERNOON ACROSS THE PEE DEE REGION...REACHING THE COAST AROUND
SUNSET OR SHORTLY THEREAFTER. A SECOND UNRELATED AREA OF SHOWERS
DEVELOPING ALONG THE GULF STREAM OFF THE GA/SC COAST IS STREAMING
NORTHWARD NEAR CHARLESTON AND GEORGETOWN...AND THREATENS TO BRING
SHOWERS ACROSS EASTERN SOUTH CAROLINA OVER THE NEXT SEVERAL HOURS.
POP/WX FORECASTS HAVE BEEN UPDATED TO FOCUS ON THESE TWO AREAS.
FEW CHANGES HAVE BEEN MADE TO FORECAST TEMPERATURES...STILL EXPECTED
TO REACH THE LOWER 70S FOR MOST AREAS AWAY FROM THE COOLING
INFLUENCE OF THE OCEAN.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SURFACE LOW AND MID LEVEL TROUGH WILL BE WEST
OF THE AREA AT THE START OF THE PERIOD WITH THE REGION SOLIDLY IN
THE WARM SECTOR. SEVERAL FACTORS APPEAR TO BE IN PLACE SUPPORTING
CONVECTION SAT INTO SAT NIGHT. STRENGTHENING MID LEVEL SOUTHWEST
FLOW WILL CONTINUE TO PUMP MOISTURE INTO THE REGION. FORECAST
SOUNDINGS SHOW PRECIPITABLE WATER VALUES CLOSE TO 1.5 INCH. DIURNAL
INSTABILITY WILL ALSO BE PRESENT WITH HIGHS EXPECTED TO CLIMB INTO
THE LOWER 70S IN MOST AREAS. LOW LEVEL CONVERGENCE ALONG THE
RESULTANT SEA BREEZE MAY INITIATE CONVECTION IN THE AFTERNOON. ALOFT
THE APPROACHING 5H TROUGH WILL ENHANCE MID LEVEL LAPSE RATES BUT THE
UNKNOWN FACTOR AT THIS POINT REMAINS WHAT IMPACT POTENTIAL
CONVECTION IN THE NORTHEAST GULF OF MEXICO WILL HAVE ON INSTABILITY
SHOWERS/THUNDERSTORMS.
FARTHER WEST A LINE OF CONVECTION SHOULD BE DEVELOPING ASSOCIATED
WITH THE ADVANCING COLD FRONT. THIS LINE WILL MOVE INTO WHAT SHOULD
BE A MOIST/UNSTABLE ENVIRONMENT LATE SAT AND PUSH OFF THE COAST SAT
NIGHT. ALTHOUGH THE FRONT WILL HAVE PLENTY OF LOW LEVEL CONVERGENCE
AND MID LEVEL SUPPORT THERE IS SOME QUESTION AS TO THE STATE OF THE
ATMOSPHERE IT WILL BE MOVING INTO. THE CONVECTIVE LINE ASSOCIATED
WITH THE FRONT MAY END UP WEAKENING AS IT MOVES INTO THE REGION IF
EARLIER AFTERNOON CONVECTION IS MORE WIDESPREAD AND USES UP A LOT OF
THE AVAILABLE INSTABILITY. ON THE OTHER HAND SHOULD THE GULF
CONVECTION BE ABLE TO SUPPRESS MUCH OF THE ACTIVITY DURING THE FIRST
HALF OF SAT THE COLD FRONT WOULD HAVE PLENTY OF INSTABILITY TO WORK
WITH. SO IT IS NOT SO MUCH A QUESTION OF WILL IT RAIN...BUT MORE OF
A QUESTION OF WHEN WILL IT RAIN.
SEVERE WEATHER THREAT PERSISTS...ALTHOUGH WITH CAVEATS. LOW LEVEL
JETTING WILL BE WEAK FOR MUCH OF THE DAY BEFORE INCREASING TO 30 TO
35 KT JUST AHEAD OF THE FRONT. THE MAIN THREAT WOULD BE DAMAGING
WIND...ENHANCED BY STORMS MOVING CLOSE TO 30 MPH. IF STRONG/SEVERE
STORMS DEVELOP THEY ARE LIKELY TO DO SO WITH THE LINE OF CONVECTION
AHEAD OF THE FRONT...AGAIN ASSUMING DIURNAL DRIVEN CONVECTION IS
LIMITED IN SCOPE DURING THE DAY SAT.
COLD FRONT PUSHES OFF THE COAST LATE SAT NIGHT WITH THE MID LEVEL
TROUGH FOLLOWING ON SUN. COLD ADVECTION BEHIND THE FRONT WILL DROP
SUN TEMPS BELOW CLIMO...BUT COLD AIR WILL BE A LITTLE TOO LATE TO
HAVE A SIGNIFICANT IMPACT ON SAT NIGHT LOWS WHICH WILL END UP NEAR
TO SLIGHTLY ABOVE CLIMO. SUN SHOULD BE DRY WITH DEEP NORTHWEST FLOW
BEHIND THE TROUGH DROPPING PWATS UNDER .5 INCH FOR SUN AM AND UNDER
.25 INCH BY SUN EVENING. GRADIENT RELAXES SUN NIGHT BUT HIGH REMAINS
WEST OF THE AREA THROUGH THE END OF THE PERIOD SO SUN NIGHT WILL NOT
BE AN IDEAL RADIATIONAL COOLING NIGHT. STILL LOWS END UP BELOW CLIMO.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...LOW AMPLITUDE MID LEVEL RIDGING AND SPRAWLING
SURFACE HIGH WILL KEEP THE AREA DRY AND SEASONABLE THROUGH THE
PERIOD. COOLEST DAY WILL BE MON WITH SURFACE HIGH DIRECTLY OVERHEAD.
HIGH THEN DRIFTS OFFSHORE TUE THROUGH THU BRINGING SEVERAL DAYS OF
BEAUTIFUL SPRING WEATHER. PREVIOUSLY MEDIUM RANGE GUIDANCE HAD BEEN
MOVING A DRY COLD FRONT ACROSS THE AREA TUE NIGHT INTO WED. NOW THAT
GUIDANCE IS SUGGESTING MORE MID LEVEL AMPLIFICATION THIS SEEMS
UNLIKELY AND IN FACT THE 00Z GUIDANCE IS BACKING OFF ON THE DRY
FRONT. TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO MON TRANSITION TO
ABOVE CLIMO MON NIGHT THROUGH THE END OF THE PERIOD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...QUITE A BIT OF UNCERTAINTY WITH RESPECT TO THE TIMING OF
THE PRECIP...AS WELL AS CEILINGS OVERNIGHT. SOUTHERLY GRADIENT WILL
CAUSE WINDS TO GUSTS OVER 20 KTS AT TIMES...ESPECIALLY ALONG THE
COAST. SCATTERED SHOWERS WILL GIVE WAY TO MORE WIDESPREAD LIGHT TO
MODERATE RAIN THIS EVENING AS DEEP MOISTURE MOVES INTO THE REGION.
RAIN CHANCES WILL BE HIGHEST INLAND THIS EVENING...SPREADING TO THE
COAST A FEW HOURS LATER. CEILINGS ARE A BIT PROBLEMATIC...BUT WILL
GO FOR MVFR PREDOMINATELY WITH POCKETS OF IFR POSSIBLE. TIME HEIGHT
INDICATES THERE MAY BE A LULL IN THE PRECIP OF ABOUT 6-7 HOURS
THROUGH THE LATE OVERNIGHT HOURS. SATURDAY...MODERATE TO PERHAPS
HEAVY PRECIP SPREADING FROM WEST TO EAST. AN EMBEDDED THUNDERSTORM
CANNOT BE RULED OUT. IN FACT...IF WE GET SOME CAPE WE COULD HAVE A
FEW STRONGER STORMS IN THE AFTERNOON INTO EARLY EVENING. AGAIN
CEILINGS PREDOMINATELY MVFR.
EXTENDED OUTLOOK...BECOMING VFR SATURDAY NIGHT. SLIGHT CHANCE FOR
SHOWERS AND MVFR CEILINGS OVER THE NORTHERN PORTION OF THE CWA.
OTHERWISE VFR THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM FRIDAY...NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE
FORECAST WITH THIS EARLY AFTERNOON UPDATE. PREVIOUS DISCUSSION FROM
1030 AM FOLLOWS...
HIGH PRESSURE THAT MOVED OFF THE NC COAST YESTERDAY IS NOW CROSSING
60 DEGREES WEST LONGITUDE AS IT CONTINUES TO PUT DISTANCE BETWEEN
ITSELF AND THE EAST COAST. LOW PRESSURE MOVING THROUGH THE GREAT
LAKES HAS A COLD FRONT EXTENDING SOUTH INTO TEXAS. THIS FRONT WILL
NOT ARRIVE UNTIL TOMORROW...ALLOWING SOUTHERLY WINDS AHEAD OF THE
FRONT TO CONTINUE ADVECTING A SUBTROPICAL AIRMASS ACROSS THE COASTAL
WATERS. AS DEWPOINTS INCREASE AND EXCEED THE NEARSHORE WATER
TEMPERATURES THERE IS AN INCREASING POTENTIAL FOR SEA FOG THIS
AFTERNOON AND TONIGHT...PARTICULARLY WITHIN 10 MILES OF SHORE WHERE
WATER TEMPERATURES ARE COLDEST.
SOUTH WINDS CURRENTLY AROUND 10-12 KNOTS SHOULD INCREASE A FEW MORE
KNOTS TODAY...BUT MAY ACTUALLY DIMINISH A LITTLE THIS EVENING AS AN
AREA OF DYING CONVECTION ARRIVES AND THE PRESSURE GRADIENT IS
DISRUPTED. REGARDLESS...WINDS SHOULD BUILD BACK UP TOWARD 12-15
KNOTS OVERNIGHT. SEAS ARE STILL A BIT HIGHER THAN WIND SPEEDS ALONE
WOULD SUGGEST...COURTESY OF THE HUGE LOW THAT MOVED NORTH THROUGH
THE WESTERN ATLANTIC A FEW DAYS AGO. AT THE FRYING PAN SHOALS BUOY
THERE IS STILL A SMALL 14 SECOND EAST SWELL PRESENT...WHICH WHEN
ADDED TO THE SHORTER 6-SECOND PERIOD WIND WAVES TOTALS AROUND 4
FEET. TOTAL SEAS EVEN INSIDE 20 MILES SHOULD INCREASE ON TOWARD 4-6
FEET BY THIS EVENING.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SOUTHERLY FLOW WILL APPROACH 20 KT SAT AS
GRADIENT OVER THE WATERS IS PINCHED BETWEEN ADVANCING COLD FRONT AND
HIGH PRESSURE. ANTICIPATE A LINE OF CONVECTION AHEAD OF THE FRONT
WHICH WILL CROSS THE WATERS SAT EVE/NIGHT. OFFSHORE FLOW DEVELOPS
BEHIND THE FRONT WITH GRADIENT AND DEVELOPING COLD ADVECTION KEEPING
SPEEDS AROUND 20 KT. LITTLE CHANGE IN THE GRADIENT SUN AS HIGH
BUILDS KEEPS NORTHWEST WINDS A SOLID 20 KT FOR MUCH OF THE DAY.
OFFSHORE FLOW SLOWLY WEAKENS SUN NIGHT...DROPPING TO 15 KT BY THE
END OF THE PERIOD...AS GRADIENT RELAXES. SEAS 4 TO 6 FT EXPECTED SAT
INTO SUN WHEN OFFSHORE COMPONENT DROPS SEAS TO 3 TO 5 FT. CONTINUED
OFFSHORE FLOW COMBINED WITH REDUCTION IN SPEEDS SUN NIGHT WILL DROP
SEAS TO 2 TO 4 FT BY THE END OF THE PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...OFFSHORE FLOW AROUND 15 KT AT THE START OF THE
PERIOD WILL DECREASE DURING MON AS HIGH PRESSURE MOVES OVER HEAD.
SPEEDS WILL DROP UNDER 10 KT BY MON EVENING...BECOMING LIGHT AND
VARIABLE MON NIGHT. HIGH SHIFTS OFFSHORE FOR TUE WITH RETURN FLOW
SLOWLY RISING INTO THE 10 TO 15 KT RANGE LATE TUE AND TUE NIGHT.
SEAS WILL RUN 2 TO 3 FT FOR A MAJORITY OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT
SATURDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
521 PM CDT FRI MAR 28 2014
.UPDATE...
QUICK UPDATE TO ADD MENTION OF SEVERE THUNDERSTORM WATCH 39 WHICH
WILL INCLUDE THE HOUSTON METRO AREA THIS EVENING. 38
&&
.PREV DISCUSSION... /ISSUED 328 PM CDT FRI MAR 28 2014/
DISCUSSION...
AT 2 PM...A WEAK SURFACE LOW WAS LOCATED OVER CENTRAL TEXAS WITH A
WARM FRONT TO THE NORTHEAST...A DRY LINE EXTENDING SOUTH TOWARD
LAREDO AND A COLD FRONT EXTENDING WEST TOWARD THE BIG BEND.
CONVECTION HAS FIRED IN CENTRAL TEXAS THIS AFTERNOON BUT COVERAGE
REMAINS LIMITED. A SOUNDING FROM TEXAS A&M SHOWS A DECENT CAP
BETWEEN 900-800 MB AND CONSIDERABLE DRY AIR AT 800 MB. LOOKS LIKE
TEMPS WILL NEED TO WARM TO AROUND 86 DEGREES TO BREAK THE CAP.
CONVECTION OVER CENTRAL TEXAS WILL CONTINUE TO PUSH EAST AND COULD
HOLD TOGETHER AND MOVE ACROSS THE NORTHERN THIRD OF SE TX. THE
RAP...TEXAS TECH WRF AND HRRR ALL ARE SUPPORTIVE OF CONVECTION
MOVING ACROSS THE NORTH PART OF SE TX THIS EVENING BUT ALL THREE
MODELS HAVE BEEN TOO AGGRESSIVE WITH RAIN CHANCES YESTERDAY AND
AGAIN TODAY. WILL GO WITH LIKELY POPS OVER THE NORTH AND CHANCE
POPS CENTRAL. WILL MENTION SOME STORMS SEVERE OVER THE NORTH.
DENSE SEA FOG CONTINUES ALONG THE COAST. WEB CAMS AND SFC OBS CONT
TO SHOW DENSE SEA FOG IMPINGING ON THE COAST AND OFFSHORE. WILL
PROBABLY NEED A DENSE FOG ADVISORY TONIGHT FOR THE COASTAL
COUNTIES THROUGH 06Z. THE RAP AND GFS ARE FASTER WITH A COLD FRONT
TONIGHT AND IT APPEARS THAT THE FRONT WILL CLEAR THE COAST CLOSER
TO 06Z THAN 12Z SAT. ONCE WINDS GO OFFSHORE...DRIER AIR WILL
FILTER IN AND THE FOG WILL BEGIN TO DISSIPATE. HIGH PRESSURE WILL
DOMINATE SATURDAY AND SUNDAY WITH SEASONAL TEMPS AND PLENTY OF
SUNSHINE.
CLOUDS WILL RETURN LATE SUNDAY NIGHT AND PERSIST THROUGH MUCH OF
THE WEEK AHEAD AS HIGH PRESSURE DRIFTS EAST AND ONSHORE WINDS
PREVAIL. FCST SOUNDINGS SHOW SATURATION BENEATH A CAP SO FEEL
SOME STREAMER SHOWERS WILL BE POSSIBLE STARTING TUESDAY AND
CONTINUING THROUGH FRIDAY. TEMPERATURES WILL ALSO BE MILDER NEXT
WEEK WITH HIGHS NEAR 80 AND LOWS IN THE MID 60S. SOME DIFFERENCES
WITH REGARD TO TIMING OF DISTURBANCES EMBEDDED IN THE UPPER FLOW
SO WILL KEEP RAIN CHANCES ON THE LOW SIDE FOR NOW. GFS/ECMWF WITH
THE TIMING OF THE NEXT COLD FRONT EITHER NEXT FRIDAY OR SATURDAY.
43
MARINE...
DENSE SEA FOG TO BE THE MAIN ISSUE TONIGHT AS THE NEARSHORE DENSE
DECK CREEPS BACK ONTO THE COAST IN THE COMING HOURS. ANOTHER DENSE
SEA FOG ADVISORY LIKELY IN THE HOURS LEADING UP TO THE COLD FRONT
THAT IS TIMED TO REACH THE SHORELINE AROUND MIDNIGHT...OR SHORTLY
THEREAFTER. THIS FRONTAL PASSAGE WILL SCOUR OUT THE LOWER LEVEL
MOISTURE AND RESIDENT FOG AND CLEAR SKIES THROUGH EARLY SATURDAY
MORNING. LIGHT RAIN OR DRIZZLE WILL ACCOMPANY THIS FOG. POST-FRONTAL
NORTHERLIES OVER THE FAR OFFSHORE WATERS WILL LIKELY INCREASE TO
SCEC CRITERIA FOR A SHORT WHILE SATURDAY MORNING...GENERALLY 15
KNOTS OR LESS OVER THE BAYS AND NEARSHORE WATERS WITH OCCASIONAL 15-
20KT GUSTS OVER A SLIGHT CHOP. AS HIGH PRESSURE MOVES ACROSS FROM
WEST-TO-EAST...LIGHT EASTERLIES WILL SLOWLY VEER SOUTHEASTERLY BY
SUNDAY NIGHT. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 52 78 49 76 53 / 60 10 10 10 0
HOUSTON (IAH) 58 79 52 77 55 / 40 10 10 10 0
GALVESTON (GLS) 64 74 59 73 60 / 20 10 10 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 4 AM CDT SATURDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM SATURDAY MORNING
THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
328 PM CDT FRI MAR 28 2014
.DISCUSSION...
AT 2 PM...A WEAK SURFACE LOW WAS LOCATED OVER CENTRAL TEXAS WITH A
WARM FRONT TO THE NORTHEAST...A DRY LINE EXTENDING SOUTH TOWARD
LAREDO AND A COLD FRONT EXTENDING WEST TOWARD THE BIG BEND.
CONVECTION HAS FIRED IN CENTRAL TEXAS THIS AFTERNOON BUT COVERAGE
REMAINS LIMITED. A SOUNDING FROM TEXAS A&M SHOWS A DECENT CAP
BETWEEN 900-800 MB AND CONSIDERABLE DRY AIR AT 800 MB. LOOKS LIKE
TEMPS WILL NEED TO WARM TO AROUND 86 DEGREES TO BREAK THE CAP.
CONVECTION OVER CENTRAL TEXAS WILL CONTINUE TO PUSH EAST AND COULD
HOLD TOGETHER AND MOVE ACROSS THE NORTHERN THIRD OF SE TX. THE
RAP...TEXAS TECH WRF AND HRRR ALL ARE SUPPORTIVE OF CONVECTION
MOVING ACROSS THE NORTH PART OF SE TX THIS EVENING BUT ALL THREE
MODELS HAVE BEEN TOO AGGRESSIVE WITH RAIN CHANCES YESTERDAY AND
AGAIN TODAY. WILL GO WITH LIKELY POPS OVER THE NORTH AND CHANCE
POPS CENTRAL. WILL MENTION SOME STORMS SEVERE OVER THE NORTH.
DENSE SEA FOG CONTINUES ALONG THE COAST. WEB CAMS AND SFC OBS CONT
TO SHOW DENSE SEA FOG IMPINGING ON THE COAST AND OFFSHORE. WILL
PROBABLY NEED A DENSE FOG ADVISORY TONIGHT FOR THE COASTAL
COUNTIES THROUGH 06Z. THE RAP AND GFS ARE FASTER WITH A COLD FRONT
TONIGHT AND IT APPEARS THAT THE FRONT WILL CLEAR THE COAST CLOSER
TO 06Z THAN 12Z SAT. ONCE WINDS GO OFFSHORE...DRIER AIR WILL
FILTER IN AND THE FOG WILL BEGIN TO DISSIPATE. HIGH PRESSURE WILL
DOMINATE SATURDAY AND SUNDAY WITH SEASONAL TEMPS AND PLENTY OF
SUNSHINE.
CLOUDS WILL RETURN LATE SUNDAY NIGHT AND PERSIST THROUGH MUCH OF
THE WEEK AHEAD AS HIGH PRESSURE DRIFTS EAST AND ONSHORE WINDS
PREVAIL. FCST SOUNDINGS SHOW SATURATION BENEATH A CAP SO FEEL
SOME STREAMER SHOWERS WILL BE POSSIBLE STARTING TUESDAY AND
CONTINUING THROUGH FRIDAY. TEMPERATURES WILL ALSO BE MILDER NEXT
WEEK WITH HIGHS NEAR 80 AND LOWS IN THE MID 60S. SOME DIFFERENCES
WITH REGARD TO TIMING OF DISTURBANCES EMBEDDED IN THE UPPER FLOW
SO WILL KEEP RAIN CHANCES ON THE LOW SIDE FOR NOW. GFS/ECMWF WITH
THE TIMING OF THE NEXT COLD FRONT EITHER NEXT FRIDAY OR SATURDAY.
43
&&
.MARINE...
DENSE SEA FOG TO BE THE MAIN ISSUE TONIGHT AS THE NEARSHORE DENSE
DECK CREEPS BACK ONTO THE COAST IN THE COMING HOURS. ANOTHER DENSE
SEA FOG ADVISORY LIKELY IN THE HOURS LEADING UP TO THE COLD FRONT
THAT IS TIMED TO REACH THE SHORELINE AROUND MIDNIGHT...OR SHORTLY
THEREAFTER. THIS FRONTAL PASSAGE WILL SCOUR OUT THE LOWER LEVEL
MOISTURE AND RESIDENT FOG AND CLEAR SKIES THROUGH EARLY SATURDAY
MORNING. LIGHT RAIN OR DRIZZLE WILL ACCOMPANY THIS FOG. POST-FRONTAL
NORTHERLIES OVER THE FAR OFFSHORE WATERS WILL LIKELY INCREASE TO
SCEC CRITERIA FOR A SHORT WHILE SATURDAY MORNING...GENERALLY 15
KNOTS OR LESS OVER THE BAYS AND NEARSHORE WATERS WITH OCCASIONAL 15-
20KT GUSTS OVER A SLIGHT CHOP. AS HIGH PRESSURE MOVES ACROSS FROM
WEST-TO-EAST...LIGHT EASTERLIES WILL SLOWLY VEER SOUTHEASTERLY BY
SUNDAY NIGHT. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 52 78 49 76 53 / 60 10 10 10 0
HOUSTON (IAH) 58 79 52 77 55 / 40 10 10 10 0
GALVESTON (GLS) 64 74 59 73 60 / 20 10 10 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 PM CDT FRI MAR 28 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 346 PM CDT FRI MAR 28 2014
AT 3 PM...WATER VAPOR SHOWED A WEAKENING SHORT WAVE TROUGH MOVING
INTO SOUTHWEST MINNESOTA...AND MORE IMPRESSIVE SHORT WAVE MOVING
THROUGH SOUTHERN MISSOURI. THE 28.00Z MODELS ARE IN GENERAL
AGREEMENT THAT THE NORTHERN SYSTEM WILL CONTINUE TO WEAK TONIGHT
AND THE SOUTHERN STREAM SYSTEM WILL REMAIN THE DOMINANT SYSTEM.
THESE 2 SYSTEMS EVENTUALLY MERGE ACROSS CENTRAL ILLINOIS AND
INDIANA WITH AN INVERTED TROUGH EXTENING NORTHWEST TOWARD
NORTHEAST IOWA AND SOUTHWEST WISCOSNIN. WITH NORTHERLY FLOW
BRINGING DRIER AIR INTO THE REGION...THIS TROUGH WILL HAVE VERY
LITTLE MOISTURE TO WORK WITH. AS A RESULT...JUST EXPECT SOME
CLOUDS WITH THIS SYSTEM FOR TONIGHT AND EARLY SATURDAY MORNING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 346 PM CDT FRI MAR 28 2014
ON SUNDAY...THERE IS A BIT OF CONCERN ON THE HIGH TEMPERATURES.
MUCH OF THIS HAS TO DEAL WITH THE SPEED OF THE SYSTEM EJECTING OUT
OF THE CENTRAL PLAINS. THE NAM IS MUCH FASTER AT EJECTING THIS
SYSTEM TOWARD THE REGION...THUS...THE SOUTHERLY WINDS ARE MUCH
STRONGER ACROSS THE AREA. MEANWHILE THE GFS...GEM...AND ECMWF ARE
WEAKER WITH THESE SOUTHERLY WINDS. IN ADDITION...THESE MODELS
ALLOW A CANADIAN COLD FRONT DROP A BIT FURTHER SOUTH INTO THE
FORECAST AREA. AS A RESULT...THERE IS SOME CONCERN THAT
TEMPERATURES MAY NOT GET AS WARM NORTH OF THE INTERSTATE 90
CORRIDOR. SINCE THE CONSENSUS WAS TO GO WITH THE LATTER
MODELS...COOLED THE HIGH TEMPERATURES A BIT NORTH OF INTERSTATE
90.
FROM SUNDAY NIGHT INTO MONDAY NIGHT...BOTH THE GEM AND ECWMF HAVE
SLOWED THEIR MOVEMENT OF THE SURFACE LOW AND STRONG NEGATIVELY
TILTED SHORT WAVE TROUGH THE REGION. THEY ARE NOW MUCH CLOSER TO
THE GFS SOLUTION WHICH DOES NOT MOVE THESE SYSTEM THROUGH THE AREA
UNTIL THE LATE AFTERNOON AND EVENING. THIS SLOW DOWN IS NOTHING
UNUSUAL WITH SOUTHWEST SYSTEMS AND WOULD NOT BE SURPRISED TO SEE
SOME MORE SLOWING WITH THIS SYSTEM. MEANWHILE THE NAM/WRF HAS A
SLIGHTLY WEAKER WAVE WAVE ALOFT AND THE SURFACE LOW MOVES QUICKLY
NORTHEAST THROUGH THE AREA ON MONDAY NIGHT. THIS MODEL APPEARS TO
BE AN OUTLIER...SO IT WAS NOT USED FOR THIS TIME PERIOD. WHILE THE
GFS...GEM...AND ECMWF ARE IN GOOD AGREEMENT WITH OVER 50 KNOTS OF
0-6 KM SHEAR AND HELICITIES OF OVER 500 WITH THIS WAVE...THEY
DIFFER ON THE MOST UNSTABLE CAPE ACROSS THE REGION. THE GFS HAS
MUCH MORE PRECIPITATION IN THE WARM SECTOR OF THIS SYSTEM /WHICH
COVERS THE SOUTHERN 2/3RDS OF THE FORECAST AREA/. AS A RESULT...IT
HAS VERY LITTLE CAPE. THE ECWMF HAS A SLIGHTLY MORE CLEANER OF THE
WARM SECTOR OF THIS SYSTEM PRIOR TO THE COLD FRONT...THUS...IT HAS
SLIGHTLY GREATER MOST UNSTABLE CAPES /UP TO 300 J/KG/. THE GEM HAS
VERY LITTLE CONVECTION IN THE WARM SECTOR PRIOR TO THE COLD FRONT.
THIS ALLOWS THE MOST UNSTABLE CAPES TO CLIMB UP TO 700 J/KG. WITH
THIS LATTER SCENARIO...THERE WOULD BE MORE CONCERN ABOUT THE
POTENTIAL FOR SUPER CELL THUNDERSTORMS. WHILE THERE IS STILL A LOT
OF UNCERTAINTY ON THE SEVERE WEATHER THREAT...THE STRENGTH OF THIS
SYSTEM AND THE POTENTIAL FOR SLANTWISE AND UPRIGHT CONVECTION
LOOKS TO BE ENOUGH TO WARRANT AT LEAST THE MENTION OF THUNDER
ACROSS THE ENTIRE FORECAST AREA FROM MONDAY AFTERNOON INTO MONDAY
EVENING. IN ADDITION WITH THE SLOWER MOVEMENT INTO THE
AREA...INCREASED MONDAY HIGH TEMPERATURES AND MONDAY NIGHT LOW
TEMPERATURES ACROSS THE NORTHEAST IOWA AND WESTERN WISCONSIN.
FROM TUESDAY NIGHT THROUGH FRIDAY...THE 28.12Z MODELS CONTINUE TO
STRUGGLE WITH THE TRACK OF 2 LOW PRESSURE SYSTEMS THROUGH THE MID
AND UPPER MISSISSIPPI RIVER VALLEY. THE ECWMWF HAS SHIFTED FURTHER
NORTH...RESULTING IN MORE OF A RAIN SOLUTION FOR THE AREA.
MEANWHILE THE GFS AND GEM HAVE A MUCH MORE ACTIVE SOUTHERN STREAM
SYSTEM. AS A RESULT...THERE IS MORE OF A MIX FOR THE WEDNESDAY
THROUGH THURSDAY...AND THE SYSTEM FOR THURSDAY NIGHT AND FRIDAY
WILL BE SOUTH OF THE AREA. DUE TO THIS POOR MODEL CONSISTENCY AND
AGREEMENT...JUST STAYED WITH MODEL CONSENSUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1241 PM CDT FRI MAR 28 2014
MAIN AVIATION CONCERN IS MVFR STRATUS DECK SOUTH OF TAF SITES TO
PERSIST THIS AFTERNOON. LATEST 28.12Z NAM AND 28.15Z RAP NOT
HANDLING THE ERODING OF LOW STRATUS DECK/MOISTURE WELL PER LATEST
VISIBLE SATELLITE IMAGERY. WITH DRY NORTHERLY FLOW AND SUBSIDENCE
UNDER SURFACE HIGH OVER NORTHERN MINNESOTA...EXPECT THE
MVFR/STRATUS DECK TO DIMINISH ON NORTHERN PERIPHERY AND PRODUCE A
SCATTER DECK OF 2500 TO 3500 FEET AT THE RST/LSE TAF SITES THIS
AFTERNOON. WEAK LOW PRESSURE WILL MOVE INTO THE CENTRAL PLAINS
STATES THIS AFTERNOON/TONIGHT AND SPREAD A MID DECK(ABOVE 10K
FEET) OF CLOUDS OVER THE TAF SITES. THE 28.12Z GFS/NAM BUFKIT
SOUNDINGS ARE SHOWING AN INVERSION DEVELOPING TONIGHT AND
MOISTENING UP THE NEAR SURFACE BOUNDARY LAYER. THIS MOISTURE LOOKS
OVERDONE...AS REGION WILL BE UNDER THE INFLUENCE OF SURFACE HIGH
OVER NORTHERN WISCONSIN. EXPECT VFR CONDITIONS TO PREVAIL AT BOTH
LSE/RST TAF SITES TONIGHT THROUGH THE REST OF THE TAF PERIOD.
&&
.HYDROLOGY...
ISSUED AT 346 PM CDT FRI MAR 28 2014
MINOR FLOODING IS EXPECTED TO CONTINUE INTO SATURDAY ALONG PARTS
OF KICKAPOO AS RUNOFF FROM LAST NIGHT/S RAINFALL WORKS ITS WAY
DOWN THE RIVER.
FROM SUNDAY INTO MONDAY NIGHT...THE RAPID WARM UP WILL CAUSE THE
SNOW PACK NORTH OF INTERSTATE 94 TO MELT RAPIDLY. IN
ADDITION WITH FROZEN GROUND...ADDITIONAL RAINFALL ON MONDAY AND
MONDAY NIGHT WILL QUICKLY RUNOFF INTO AREA RIVERS AND STREAMS. THIS
WILL RESULT IN RISES ALONG THE BLACK...BUFFALO...AND TREMPEALEAU
RIVERS IN WESTERN WISCONSIN. THERE IS A DISTINCT POSSIBILITY THAT
THERE WILL BE THE POTENTIAL FOR SOME FLOODING ALONG THESE RIVERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DTJ
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1241 PM CDT FRI MAR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CDT FRI MAR 28 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE U.S. WEST COAST INTO BRITISH COLUMBIA...A
PACIFIC SHORTWAVE OVER WYOMING...A VIGOROUS PACIFIC SHORTWAVE NEAR
DAVENPORT IA...AND A POLAR SHORTWAVE OVER LAKE WINNIPEG. THE
DAVENPORT IA SHORTWAVE...IN COMBINATION WITH PRECIPITABLE WATER
VALUES OF 0.6-0.9 INCHES / 200 PERCENT OF NORMAL / AND FRONTOGENESIS
HELPED PRODUCE PRECIPITATION ACROSS MUCH OF THE FORECAST AREA
YESTERDAY TO AROUND MIDNIGHT. MUCH OF THIS PRECIPITATION FELL AS
RAIN...WHICH WITH FROZEN GROUND HAS LED TO PLENTY OF RUNOFF AND
RISES ON AREA RIVERS AND STREAMS. SEE THE HYDROLOGY SECTION FOR MORE
INFORMATION. SOME OF THE PRECIPITATION FELL AS SNOW...MAINLY IN
NORTHWEST TO NORTH SECTIONS OF THE AREA...WITH THE MOST IN TAYLOR
COUNTY. LOW LEVEL CYCLONIC FLOW AROUND LOW PRESSURE OVER CENTRAL
LAKE MICHIGAN HAS KEPT CLOUDS IN PLACE THROUGH THE NIGHT...THOUGH
CLEARING WAS EVIDENT OVER THE NORTHWEST HALF OF MINNESOTA.
PRECIPITABLE WATER AT BIS WAS QUITE LOW WITH THE RIDGE...0.17 INCHES
AT BIS AND ABR OR 50-60 PERCENT OF NORMAL. COLDER AIR WAS ALSO
FILTERING IN...REFLECTING A CANADIAN RIDGE OF HIGH PRESSURE BUILDING
SOUTH INTO THE UPPER MIDWEST. FARTHER TO THE WEST...CLOUDS AND SOME
SCATTERED LIGHT PRECIPITATION WAS OCCURRING OVER WYOMING WITH THE
SHORTWAVE THERE.
AFTER AN ACTIVE PERIOD OF PRECIPITATION THE PAST 24 HOURS...THIS
SHORT TERM PERIOD LOOKS MUCH QUIETER. FOCUS FOR ANY POTENTIAL
PRECIPITATION WOULD BE ON THE SHORTWAVE OVER WYOMING...WHICH IS
PROGGED BY MODELS TO CROSS THE FORECAST AREA TONIGHT. HOWEVER...
THERE ARE 2 ITEMS GOING AGAINST PRECIPITATION... 1. ANOTHER
SHORTWAVE COMING OUT OF ARIZONA IS SUGGESTED TO INTENSIFY AND DEEPEN
AS IT REACHES MISSOURI TONIGHT...ROBBING THE WYOMING SHORTWAVE OF
MOISTURE. 2. THE WYOMING SHORTWAVE WILL BE HEADING INTO A DRY
AIRMASS AS SEEN ON THE BIS/ABR SOUNDINGS. MODELS CONTINUE TO DEPICT
THAT ANY PRECIPITATION WITH THE SHORTWAVE WILL DRY UP BEFORE THE
SHORTWAVE GETS TO THE FORECAST AREA...THUS STAYED WITH A DRY
FORECAST.
CLOUDS AND TEMPERATURES NOW BECOME THE MAIN CONCERNS. LOW CLOUDS
LOOK TO QUICKLY EXIT OFF TO THE EAST THIS MORNING AS THE DRIER AIR
TO OUR NORTHWEST ADVECTS IN. SCT-BKN MID AND HIGH CLOUDS WILL THEN
TRAVERSE THE AREA THIS AFTERNOON THROUGH TONIGHT AS THE WYOMING
SHORTWAVE MOVES THROUGH. 925MB TEMPS ARE PROGGED BETWEEN -2 TO -6C
AT 18Z...THOUGH MORE SUN TODAY WILL HELP TO COUNTERACT SOME OF THE
COLDER AIR. IN FACT...OVER THE SNOW FREE AREAS...TEMPERATURES MAY
EVEN END UP A LITTLE WARMER THAN YESTERDAY. ALTHOUGH SURFACE WINDS
LOOK LIGHT TONIGHT...THE CLOUDS SHOULD HELP TO HOLD READINGS UP FROM
THE MID TEENS TO MID 20S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 311 AM CDT FRI MAR 28 2014
MUCH OF THE LONG TERM PERIOD FOCUSES ON AN IMPRESSIVE LONG WAVE
TROUGH SITTING OVER THE EASTERN PACIFIC. ALL MODELS SHOW THAT A
POTENT SHORTWAVE WILL COME OUT OF THIS TROUGH AND TRACK INTO THE
FORECAST AREA FOR MONDAY. THEN THE ENTIRE TROUGH LOOKS TO COME INTO
THE WESTERN U.S. ON TUESDAY...TRACKING INTO THE CENTRAL PLAINS ON
THURSDAY.
MUCH OF FRIDAY NIGHT THROUGH SUNDAY LOOKS TO BE DOMINATED BY
BUILDING RIDGING AHEAD OF THE POTENT SHORTWAVE MARCHING ACROSS THE
WESTERN U.S.. NO CONCERNS FOR PRECIPITATION DURING THIS PERIOD AS
THE FORECAST AREA TRANSITIONS FROM UNDER DOMINANCE OF HIGH PRESSURE
TO INTO THE WARM SECTOR OF A DEEPENING SURFACE CYCLONE OVER
NORTHEAST COLORADO. TEMPERATURES AND WINDS ARE THE MAIN ISSUES.
925MB TEMPS ARE PROGGED SLIGHTLY WARMER ON SATURDAY...0 TO -
4C...WHICH WITH WHAT LOOKS TO BE PLENTY OF SUN SHOULD HELP BOOST
TEMPS INTO THE 40S...PERHAPS EVEN AROUND 50 IN SOME VALLEY
LOCATIONS. SOUTH TO SOUTHWEST WINDS REALLY PICK UP SATURDAY
NIGHT...UPWARDS OF 40-50 KT BY 12Z SUN AT 925MB...CAUSING 925-850MB
TEMPS TO REALLY CLIMB. ANTICIPATING LOWS IN THE EVENING SATURDAY
NIGHT...THEN HOLD STEADY TO SLOWLY RISE AS THE WARM AIR SURGES IN.
THE CLIMB CONTINUES THROUGH SUNDAY AS THE 925MB TEMPS CLIMB TO AS
MUCH AS 10-13C BY 00Z MONDAY. 400-250MB RH PROGS SUGGESTS PLENTY OF
SCT-BKN CIRRUS...BUT THE SUN AND WARM 925MB TEMPS SHOULD HELP PROPEL
READINGS INTO THE FIRST 60S OF THE YEAR FOR MOST LOCATIONS. MORE
SNOWPACK OVER TAYLOR/CLARK WILL HOLD READINGS BACK THERE INTO THE
50S...THOUGH THIS SNOWPACK IS GOING TO MELT FAST GIVEN THE WARM AIR
AND BREEZY CONDITIONS...YIELDING HYDRO CONCERNS. SEE HYDROLOGY
SECTION.
ATTENTION THEN TURNS TO THE POTENT SHORTWAVE HEADING INTO THE
FORECAST AREA FOR MONDAY. BOTH THE GFS AND ECMWF HAVE REALLY SLOWED
AND DEEPENED THIS SHORTWAVE AND THE ASSOCIATED SURFACE LOW OVER THE
PAST 24-48 HOURS. THIS RESULTS IN THE FORECAST AREA STAYING IN THE
WARM SECTOR LONGER AND THUS WARMER CONDITIONS ARE FORECAST FOR
SUNDAY NIGHT AND MONDAY. THERE ARE A COUPLE OF PRECIPITATION IMPACTS
TOO. FIRST...THE DEFORMATION BAND ON THE NORTHWEST SIDE OF THE LOW
NOW ONLY LOOKS TO IMPACT THE NORTHWEST HALF OF THE AREA MONDAY
AFTERNOON AND NIGHT...THOUGH IT MAY STAY ENTIRELY NORTHWEST OF THE
FORECAST AREA. SECOND...A LEAD WAVE OF RAIN RESULTING FROM
ISENTROPIC LIFT IS LOOKING LIKELY TO PROGRESS ACROSS THE FORECAST
AREA LATE SUNDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THIRD...THE
SYSTEMS COLD FRONT AND STRONG DYNAMICS ARE PROGGED TO MOVE THROUGH
MONDAY AFTERNOON AND EVENING. THERE IS A CAP TO BE OVERCOME...BUT
WITH SUCH STRONG FORCING...CANNOT RULE OUT A BAND OF SHOWERS AND
STORMS FIRING ON THE FRONT. SHOULD STORMS FORM...WHICH IS A BIG
IF...THERE IS AMPLE SHEAR TO SUPPORT SEVERE. WE WILL NEED TO KEEP AN
EYE ON INSTABILITY VERSUS CAPPING FOR MONDAY AFTERNOON.
TUESDAY INTO TUESDAY NIGHT LOOK TO BE QUIET AND MUCH COLDER...THEN
WEATHER GETS ACTIVE AGAIN FOR WEDNESDAY INTO THURSDAY AS THE REST OF
THE UPPER TROUGH LIFTS TOWARDS THE REGION. THIS TIME AROUND...WE MAY
HAVE TO DEAL WITH A WINTRY MIX SIDE DUE TO WARM/MOIST ADVECTION
ALOFT AND A FLOW OF DRY AIR AND COLD ADVECTION AT THE SURFACE.
THEN...IF THE 28.00Z ECMWF IS CORRECT...WE WILL AT LEAST CHANGE OVER
TO ALL RAIN AND PERHAPS BRING MORE THUNDERSTORMS. NEEDLESS TO
SAY...PLENTY OF UNCERTAINTY OUT THIS FAR AND THUS STAYED WITH A
MODEL CONSENSUS FOR NOW. CERTAINLY ANOTHER ITEM TO WATCH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1241 PM CDT FRI MAR 28 2014
MAIN AVIATION CONCERN IS MVFR STRATUS DECK SOUTH OF TAF SITES TO
PERSIST THIS AFTERNOON. LATEST 28.12Z NAM AND 28.15Z RAP NOT
HANDLING THE ERODING OF LOW STRATUS DECK/MOISTURE WELL PER LATEST
VISIBLE SATELLITE IMAGERY. WITH DRY NORTHERLY FLOW AND SUBSIDENCE
UNDER SURFACE HIGH OVER NORTHERN MINNESOTA...EXPECT THE
MVFR/STRATUS DECK TO DIMINISH ON NORTHERN PERIPHERY AND PRODUCE A
SCATTER DECK OF 2500 TO 3500 FEET AT THE RST/LSE TAF SITES THIS
AFTERNOON. WEAK LOW PRESSURE WILL MOVE INTO THE CENTRAL PLAINS
STATES THIS AFTERNOON/TONIGHT AND SPREAD A MID DECK(ABOVE 10K
FEET) OF CLOUDS OVER THE TAF SITES. THE 28.12Z GFS/NAM BUFKIT
SOUNDINGS ARE SHOWING AN INVERSION DEVELOPING TONIGHT AND
MOISTENING UP THE NEAR SURFACE BOUNDARY LAYER. THIS MOISTURE LOOKS
OVERDONE...AS REGION WILL BE UNDER THE INFLUENCE OF SURFACE HIGH
OVER NORTHERN WISCONSIN. EXPECT VFR CONDITIONS TO PREVAIL AT BOTH
LSE/RST TAF SITES TONIGHT THROUGH THE REST OF THE TAF PERIOD.
&&
.HYDROLOGY...
ISSUED AT 311 AM CDT FRI MAR 28 2014
AREA RIVERS AND STREAMS CONTINUE TO MOSTLY RISE EARLY THIS MORNING
FROM THE RECENT RAIN. RAINFALL AMOUNTS AS MUCH AS A LITTLE OVER 1
INCH WERE OBSERVED...HIGHEST OVER THE SOUTHEAST HALF OF THE
FORECAST AREA. WITH FROZEN GROUND...MUCH OF THIS RAIN HAS TURNED
INTO RUNOFF. SO FAR THE ONLY FLOOD WARNING ISSUED AND VERIFIED WAS
ONTARIO...WHILE MOST OTHER RIVERS AND STREAMS ARE STAYING BELOW
FLOOD STAGE. EXPECTING MOST SHORT RESPONDING SITES LIKE ONTARIO TO
BEGIN FALLING SOON...WHILE LONGER RESPONDING LOCATIONS WILL CLIMB
FOR THE NEXT DAY OR SO AS RUNOFF CONTINUES TO FILTER THROUGH. SEE
THE LATEST HYDROLOGY RELATED STATEMENTS FOR MORE DETAILS.
NEXT HYDROLOGY CONCERN COMES SUNDAY THROUGH MONDAY AS A STRONG
SURGE OF WARM AIR COMES INTO THE REGION ON BREEZY SOUTH WINDS. IN
ADDITION...RAIN APPEARS LIKELY ON MONDAY. WITH PLENTY OF SNOW
STILL PRESENT ALONG/NORTH OF HIGHWAY 10...CONCERN THAT THIS SNOW
COULD RAPIDLY MELT...RESULTING IN MORE RISES ON RIVERS SUCH AS THE
TREMPEALEAU AND BLACK. WILL ISSUE AN ESF TO COVER THE POTENTIAL
FOR FLOODING. SOMEWHAT COOLER AIR FLOWING IN FOR TUESDAY AND
WEDNESDAY WILL SLOW THE MELT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DTJ
HYDROLOGY...AJ