Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/13/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1045 AM MDT THU APR 11 2013
.UPDATE...
&&
.SHORT TERM...SNOW CONTINUING ACROSS MOUNTAINS WITH THE BEST
SNOWFALL ALONG CONTINENTAL DIVIDE OF SUMMIT AND GRAND COUNTIES.
NORTHWEST FLOW PROVIDING GOOD OROGRAPHICS AS AREA HAS BEEN IN THE
FAVORED LIFT OF JET PASSING ACROSS WYOMING. ALSO...LAPSE RATES
AROUND 6 OR 7 C/KM ADDING TO SNOWFALL. SOME LIGHT SNOW OCCURRING
ACROSS MOUNTAIN VALLEYS. ACROSS FOOTHILLS AND PLAINS...A FEW
SHOWERS TRYING TO DEVELOP NEAR THE WYOMING BORDER BUT DOWNSLOPE
FLOW LIMITING THE DEVELOPMENT. FAVORED OROGRAPHICS IN NORTHWEST
FLOW ALOFT TO CONTINUE ACROSS MOUNTAINS THROUGH THE DAY...THOUGH
FAVORED LIFT FROM THE JET WILL BE SHIFTING INTO NEBRASKA BY THE
AFTERNOON. PLATTEVILLE PROFILER SHOWING WINDS ALOFT HAVE DECREASED
A BIT...IMPLYING THE JET IS MOVING AWAY FROM THE AREA.
STILL...LATEST RAP SHOWS LAPSE RATES AROUND 6 C/KM CONTINUING
THROUGH THE DAY...AND WITH OROGRAPHICS AND MOISTURE PRESENT...
SHOULD SEE SNOW CONTINUING OVER THE MOUNTAINS THROUGH THE DAY.
ADDITIONAL ACCUMULATIONS LOOK TO BE AROUND 3 TO 5 INCHES ALONG THE
DIVIDE...WITH LESS AMOUNTS ELSEWHERE. WILL CONTINUE THE MOUNTAIN
ADVISORY. ELSEWHERE...STILL APPEARS PRECIPITATION CHANCES LOOK LOW
GIVEN LACK OF ANY MID LEVEL QG ASCENT AND LOCAL DOWNSLOPE. BUT
WITH JET IN THE AREA...WILL CONTINUE THE CURRENT POPS. TEMPS THIS
AFTERNOON LOOK A BIT WARM FOR SNOW ON THE PLAINS...COULD BE SOME
MIX DURING THE EVENING. PRECIP TO DECREASE ACROSS MOUNTAINS AND
END ACROSS PLAINS DURING THE EVENING AS DRIER SUBSIDENT AIR MOVES
INTO THE AREA. SOME CLEARING ACROSS PLAINS COULD LEAD TO FOG
DEVELOPMENT AFTER MIDNIGHT.
.AVIATION...CURRENT TAF TRENDS LOOK ON TRACK...THOUGH WINDS HAVE
SHIFTING TO THE NORTHWEST. SHOULD SHIFT TO THE NORTH NORTHEAST
AFTER 18Z. STILL SOME FOG FLOATING AROUND AREA AIRPORTS...SHOULD
BE DISSIPATING BY 18Z. OTHERWISE...CEILINGS OF AROUND 7000 FEET
AGL TO PREVAIL THROUGH THE AFTERNOON. A FEW SHOWERS POSSIBLE THIS
AFTERNOON AND EVENING MAINLY EAST AND SOUTH OF DENVER. COULD SEE
CEILINGS LOWER TO AROUND 5000-6000 FEET WITH THE PASSING SHOWERS.
IF SHOWERS AFFECT THE AIRPORTS...COULD BE A MIXTURE OF RAIN AND
SNOW AROUND 23Z...WITH MAINLY SNOW AROUND 02Z. THE SHOWERS SHOULD
BE BRIEF WITH NO ACCUMULATION EXPECTED. SOME CLEARING BY MIDNIGHT
WITH A SLIGHT CHANCE OF FOG DEVELOPING. WILL CONTINUE WITH THE
VCFG FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 412 AM MDT THU APR 11 2013/
SHORT TERM...A POTENT LITTLE DISTURBANCE BEING CARRIED ALONG BY
80+KT NORTHWESTERLY FLOW ALOFT IS ALREADY BRINGING SNOW AND GUSTY
WINDS TO THE NORTHERN MTNS OF COLORADO. IN THE PAST HOUR OR SO...
CDOT CAMS AT THE EISENHOWER TUNNEL AND ON VAIL PASS HAVE SHOWN
SOME PRETTY WINTERY CONDITIONS UP THERE...AND THE BEST MOISTURE
AND FORCING FOR ASCENT STILL UPSTREAM OVER NERN UT/SWRN WY.
THEREFORE SHOULD CONTINUE TO SEE A GRADUAL DETERIATION IN WX
CONDITIONS AT HIGHER ELEVATIONS IN MTN ZONES 31..33 AND 34 DURING
THE NEXT 2-4 HOURS. COULD SEE SNOWFALL RATES APPROACHING 1 TO 1.5
INCHES PER HOUR LATER THIS MORNING ON WEST-NORTHWEST FACING
SLOPES...WITH TOTAL SNOW ACCUMULATIONS BY 00Z TODAY IN THE 4 TO 7
INCH RANGE. HOWEVER...MAY SEE HIGHER AMOUNTS IN PARTS OF THE PARK
AND GORE RANGES. FOR THAT REASON...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR SNOW AND BLOWING SNOW IN THE ABOVE MENTION MTN ZONES
NOW UNTIL 6 PM MDT TODAY. BASED ON ITS CURRENT FORWARD SPEED AND
MODEL GUIDANCE...SHOULD SEE HIGH COUNTRY SNOWFALL AND WIND SPEEDS
DIMINISHING THIS EVENING WITH DRYING AND SUBSIDENCE MOVING IN
BEHIND THIS SYSTEM.
ELSEWHERE...SHOULD SEE A STEADY INCREASE IN CLOUD COVER OVER THE
PLAINS THIS MORNING WITH MOSTLY TO OVERCAST SKIES BY MIDDAY...IF
NOT SOONER THAN THAT. THE LACK OF ANY SIGNIFICANT FORCING FOR
ASCENT WITH THE PASSING DISTURBANCE EAST OF THE MTNS SUGGESTS
PRECIPITATION WILL BE LIMITED IN COVERAGE. AFTERNOON AND EARLY
EVENING APPEARS TO BE THE BEST TIME FOR ANY PRECIP ON THE PLAINS.
HAVE INTRODUCED A SCATTERING OF LOW POPS TO REFLECT THIS
POSSIBILITY. FURTHERMORE...MODEL TEMPERATURE GUIDANCE LOOKS TOO
WARM TODAY CONSIDERING THE ANTICIPATED CLOUD COVER AND LINGERING
SNOW COVER. THEREFORE HAVE BACKED OFF ON MAX TEMPS OFFERED BY MOS
GUIDANCE BY AS MUCH 5-10DEGS F.
FOR TONIGHT...SHOULD SEE SKIES GRADUALLY CLEARING FORM NORTHWEST
TO SOUTHEAST BEHIND THIS DISTURBANCE. BUT CLEARING SKIES WILL
ALLOW STRONG RADIATIONAL COOLING TO GENERATE PATCHY FOG ON THE
PLAINS AFTER MIDNIGHT...SOME OF WHICH COULD BE RATHER THICK EAST
OF THE I-25 URBAN CORRIDOR. SHOULD SEE WARMER LOW TEMPERATURES
TONIGHT WITH THE START OF WARMING ALOFT.
LONG TERM...COLORADO WILL BE UNDER A NORTHWEST FLOW PATTERN ON
FRIDAY AND EARLY SATURDAY AS A WEAK DISTURBANCE AND FRONT SLIDES
ACROSS THE AREA FRIDAY AFTERNOON AND EARLY EVENING. APPEARS THE
BEST CHANCE FOR SHOWERS WILL BE OVER THE MOUNTAINS WITH SOME
OROGRAPHIC FLOW AND OVER THE FAR NORTHEAST PLAINS...CLOSER TO THE
DYNAMICAL FORCING AND JET STREAK. SATURDAY LOOKS TO BE THE DRIEST
AND WARMEST DAY OF THE UPCOMING WEEK AS THE FLOW TRANSITIONS AND
INCREASES FROM THE WEST. WITH THE STRONGER WESTERLY FLOW...MAY BE
A BRIEF PERIOD OF HIGH WIND POTENTIAL OVER THE FRONT RANGE ON
SATURDAY NIGHT AS STRONG JET ALOFT MOVES OVER NORTHERN COLORADO.
CROSS SECTIONS SHOW CROSS BARRIER FLOW SHOWING 50-60KT SO
CERTAINLY SOME POTENTIAL THERE FOR HIGH WINDS AND DEPEND ON EXACT
POSITION OF JET.
FOR MONDAY THROUGH WEDNESDAY...LOOKS LIKE ANOTHER UNSETTLED PERIOD
OVER COLORADO AS UPPER LEVEL TROF DEVELOPS OVER THE GREAT BASIN
AND GRADUALLY MOVES ACROSS COLORADO AROUND MID WEEK. MODEL
DIFFERENCES SHOWING UP IN THE TIMING WITH THIS TROF PASSAGE WITH
GFS THE FASTEST AND EUROPEAN THE SLOWEST. NOT A LOT OF CONFIDENCE
EITHER WAY BUT CERTAINLY COOLER TEMPERATURES AND A BETTER CHANCE
FOR SHOWERS MOVING BACK INTO THE REGION BY EARLY NEXT WEEK. BEST
CHANCES TO BE OVER FAR NORTHERN COLORADO...CLOSEST TO THE JET.
AVIATION...LIGHT EASTERLY/UPSLOPE FLOW IN THE LOW LEVELS AND THE
APPROACH FROM THE WEST OF MOISTURE ATTACHED TO AN UPPER LEVEL
WEATHER DISTURBANCE SHOULD KEEP SKIES OVER DENVER AREA AIRPORTS
MOSTLY CLOUD TO OVERCAST ALL DAY. CEILINGS WILL GENERALLY RANGE
FROM 7000 TO 11000 FEET AGL...WITH PERIODS OF LOWER CIGS IN THE
4000-5000 FOOT RANGE. THE LOWERING CEILINGS MAY BE ACCOMPANIED BY
RAIN SPRINKLES OR A BRIEF RAIN SHOWER TODAY...AND POSSIBLY A BRIEF
RAIN AND SNOW SHOWER EARLY THIS EVENING. NOT EXPECTING ANY SNOW
ACCUMULATION WITH THE PASSING SHOWERS. FOR WINDS...LIGHT AND
VARIABLE WINDS EARLY THIS MORNING ARE FORECAST TO BECOME SOUTHEAST
5-8KTS LATER THIS MORNING...THEN EAST-NORTHEAST AT 6-10KTS AFTER
19Z TODAY. BY EARLY THIS EVENING...LOOK FOR A SHIFT TO
NORTHWESTERLY WINDS UNDER 8 KTS...AND EVENTUALLY TO A LIGHT
DRAINAGE WIND PATTERN BY 06Z TONIGHT. THERE IS A SMALL CHANCE THAT
DIA AND BJC COULD SEE PATCHY FOG FORMING AFTER 09Z TONIGHT.
VISIBILITIES IN THE FOG COULD BRIEFLY LOWER TO AROUND 2 MILES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ031-
033-034.
&&
$$
SHORT TERM...D-L
LONG TERM....ENTREKIN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MIAMI FL
950 PM EDT FRI APR 12 2013
.UPDATE...
THE FORECAST WAS UPDATED TO REFLECT THE DISSIPATION OF THE SHOWERS
AND THUNDERSTORMS ACROSS THE NORTHEASTERN SECTION OF PALM BEACH
COUNTY EARLIER THIS EVENING. A SLIGHT CHANCE OF SHOWERS WAS LEFT
IN THE FORECAST OVER NIGHT FOR ALL AREAS AND FOR THE OFF SHORE
GULF WATERS A SLIGHT CHANCE OF THUNDERSTORMS WAS INCLUDED.
RECENT RADAR IMAGERY INDICATES SHOWERS MOVING NORTHWARD ACROSS
THE FLORIDA STRAITS AND THE KEYS. AS THE COLD FRONT CONTINUES TO
MOVE INTO THE EASTERN GULF...THERE IS A LINE OF THUNDERSTORMS
AHEAD OF THE FRONT IN THE EASTERN GULF. THE RAPID REFRESH GUIDANCE
INDICATED THAT CONVECTION MAY REACH THE OFF SHORE GULF WATERS
AROUND 05Z WITH A SLIGHT CHANCE OF THUNDERSTORMS MENTIONED IN THE
FORECAST.
OTHERWISE...FORECAST IS ON TRACK FOR SATURDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED ACROSS THE REGION IN THE
AFTERNOON AND EARLY EVENING.
60
&&
.PREV DISCUSSION... /ISSUED 734 PM EDT FRI APR 12 2013/
AVIATION...
THE THUNDERSTORMS OVER THE PALM BEACH COUNTY AREA SHOULD
DISSIPATE BY 9 PM EDT THIS EVENING LEAVING ONLY SOME SHOWERS UNTIL
11 PM EDT. SO WILL CONTINUE THE VCTS FOR KPBI UNTIL 01Z AND THEN
VCSH UNTIL 03Z TONIGHT. REST OF THE TAF SITES ACROSS SOUTH FLORIDA
SHOULD REMAIN DRY TONIGHT. THE SHOWERS WILL COME BACK INTO PLAY AT
ALL OF THE TAF SITES BETWEEN 12Z AND 16Z ON SATURDAY...BEFORE
THUNDERSTORMS DEVELOP FOR THE AFTERNOON HOURS ON SATURDAY. SO WILL
HAVE A VCSH FROM 12Z UNTIL 16Z AND THEN VCTS AFTER 16Z SATURDAY
FOR ALL TAF SITES OVER SOUTH FLORIDA.
THE WIND SPEEDS TONIGHT AT ALL OF THE TAF SITES WILL DECREASE FROM
5 TO 10 KNOTS THIS EVENING TO LESS THAN 5 KNOTS AFTER 03Z MAINLY
FROM THE SOUTH TO SOUTHWEST DIRECTION. THE ONLY EXCEPTION TO THIS
IS AT KAPF WHERE THE WINDS WILL BE FROM THE SOUTHEAST DIRECTION.
THE WINDS WILL THEN INCREASE ON SATURDAY MORNING TO AROUND 10
KNOTS FROM THE SOUTHEAST...WITH KAPF TAF SITE SWINGING TO A
SOUTHWEST DIRECTION AFTER 16Z SATURDAY.
THE VIS SHOULD REMAIN IN THE VFR CONDITIONS TONIGHT INTO SATURDAY
AT ALL OF THE TAF SITES...EXCEPT FOR KPBI...KFLL...KFXE...AND KAPF
TAF SITES WITH THE CEILING TO FALL DOWN INTO THE MVFR CONDITIONS
BETWEEN 10Z AND 13Z TONIGHT. THE REASON FOR THIS IS FOR POSSIBLE
FOG DEVELOP OVER THE INTERIOR AREAS THAT COULD WORK INTO THESE TAF
SITES.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 230 PM EDT FRI APR 12 2013/
SHORT TERM (TONIGHT-SUNDAY NIGHT)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED PLENTY OF MID/UPPER
MOISTURE SPREADING NORTHEAST ACROSS THE FLORIDA PENINSULA WITHIN THE
SOUTHWEST UPPER FLOW AND A WEAK RIDGE AXIS EXTENDING NORTH OVER THE
BAHAMAS. THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTH AND SOUTHWEST ACROSS THE FLORIDA BIG BEND TO THE CENTRAL GULF
OF MEXICO WITH MOIST SOUTHERLY FLOW ACROSS THE FLORIDA PENINSULA
AHEAD OF IT. THE LATEST SHORT-RANGE FORECAST GUIDANCE REMAINS IN
GOOD AGREEMENT AND SHOWS THIS FRONTAL BOUNDARY CONTINUING EASTWARD
TOWARD AND INTO CENTRAL FLORIDA LATER THIS EVENING THROUGH TONIGHT
BEFORE STALLING AROUND OR JUST NORTH OF THE LAKE THROUGH THE DAY
SATURDAY. PLENTY OF DEEP LAYER MOISTURE AND SOUTHWEST DEEP LAYER
FLOW COMBINED WITH DAYTIME HEATING AND AFTERNOON SEA BREEZES WILL
SUPPORT SCATTERED SHOWERS AND STORMS THROUGH SATURDAY.
FOR THE REMAINDER OF THE AFTERNOON AND EVENING TODAY...THE BEST
CHANCE FOR THESE STORMS WILL REMAIN OVER THE NORTHERN AND EASTERN
SECTIONS OF THE AREA...ESPECIALLY OVER PALM BEACH/BROWARD COUNTIES.
THE LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THE CURRENT
TRENDS AND INDICATE THE AFTERNOON CONVECTION BECOMING CONCENTRATED
OVER THE EAST COAST METRO AND COASTAL LOCATIONS FROM BROWARD TO PALM
BEACH COUNTIES THROUGH SUNSET...THEN TRENDING DOWN THROUGH
MID/LATE-EVENING PERIODS. CONSIDERING THE MOIST PROFILES IN
PLACE...THE MAIN IMPACTS WITH THESE STORMS TODAY WILL BE WET
MICROBURSTS AND HEAVY RAINFALL. ADDITIONALLY...LOCALIZED FLOODING
CAN`T BE RULED OUT IN THE AREAS WHERE THIS ACTIVITY SETS UP.
ON SATURDAY...ANOTHER POTENTIALLY ACTIVE DAY IS ANTICIPATED DUE TO A
COMBINATION OF DEEP LAYER MOISTURE...DAYTIME HEATING/INSTABILITY AND
THE FRONTAL BOUNDARY IN THE VICINITY OF THE AREA. THIS BOUNDARY
ALONG WITH THE AFTERNOON SEA BREEZE WILL BE THE FOCUS AREAS FOR
AFTERNOON CONVECTION. THE LATEST MODEL GUIDANCE DOES INDICATE MORE
OF A SOUTHERLY FLOW UP TO 700MB THROUGH THIS PERIOD TOMORROW...WHICH
MAY RESULT IN THE AFTERNOON ACTIVITY BECOMING CONCENTRATED GENERALLY
OVER THE NORTHERN 1/3 OF THE FORECAST AREA OR AROUND THE LAKE
REGION. SATURDAY NIGHT THROUGH SUNDAY NIGHT...THIS BOUNDARY WILL
CONTINUE TO DIMINISH AND BEGIN TO LIFT BACK TO THE NORTH AS A
SHORTWAVE TROUGH LIFTS NORTHEAST OVER THE CENTRAL GULF COAST REGION.
SOUTHEAST LOW-LEVEL FLOW WILL BE EXPECTED SUNDAY WITH THE BEST
CHANCE OF AFTERNOON SHOWERS/STORMS OVER THE NWRN 1/3 OF THE FORECAST
AREA OR FROM NAPLES TO THE LAKE.
LONG TERM (MONDAY-FRIDAY)...
MOSTLY QUIET WEATHER CONDITIONS WILL BE EXPECTED AS DEEP LAYER
RIDGING REMAINS AS THE DOMINANT SYNOPTIC FEATURE THROUGH THE
MID-WEEK TIME FRAME. LATER IN THE WEEK...THE MODELS REMAIN IN DECENT
AGREEMENT...OUTSIDE OF SOME MINOR TIMING DIFFERENCES...AND GENERALLY
SHOW ANOTHER FRONTAL BOUNDARY APPROACHING AND MOVING OVER THE STATE.
IF THE MODELS REMAIN PERSISTENT WITH THIS FEATURE OVER THE WEEKEND
AND INTO THE UPCOMING WEEK...EXPECT THE EXTENDED RANGE RAINFALL
CHANCES TO STEADILY INCREASE AS CONFIDENCE RISES. OTHERWISE...QUIET
CONDITIONS WILL CONTINUE THROUGH THE WEEK WITH TEMPERATURES
REMAINING ABOVE NORMAL WITH THE MOIST SOUTHERLY FLOW IN PLACE. THE
BEST CHANCE FOR AFTERNOON SHOWERS OR STORMS WILL REMAIN INLAND FROM
NAPLES TO THE LAKE.
MARINE...
MODERATE SOUTHERLY WINDS WILL PERSIST INTO THE WEEKEND AS A COLD
FRONT APPROACHES AND STALLS JUST NORTH OF THE SOUTH FLORIDA WATERS
SATURDAY. SCATTERED SHOWERS AND A FEW STORMS WILL BE EXPECTED
THROUGH SATURDAY AS THE FRONT APPROACHES AND STALLS JUST NORTH OF
THE AREA. THIS FRONTAL BOUNDARY WILL DIMINISH OVER THE WEEKEND AND
INTO THE UPCOMING WEEK WITH HIGH PRESSURE EXPECTED TO BUILD BACK
OVER THE AREA NEXT WEEK.
FIRE WEATHER...
PLENTY OF MOISTURE ALONG WITH INCREASING RAIN CHANCES WILL PRECLUDE
ANY CHANCE FOR CRITICAL FIRE WEATHER CONDITIONS THROUGH THE WEEKEND
AS A COLD FRONT APPROACHES AND STALLS AROUND THE LAKE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 84 71 83 / 20 50 20 20
FORT LAUDERDALE 74 85 73 84 / 20 50 20 20
MIAMI 73 86 72 84 / 20 40 20 20
NAPLES 72 83 70 86 / 20 40 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
734 PM EDT FRI APR 12 2013
.AVIATION...
THE THUNDERSTORMS OVER THE PALM BEACH COUNTY AREA SHOULD
DISSIPATE BY 9 PM EDT THIS EVENING LEAVING ONLY SOME SHOWERS UNTIL
11 PM EDT. SO WILL CONTINUE THE VCTS FOR KPBI UNTIL 01Z AND THEN
VCSH UNTIL 03Z TONIGHT. REST OF THE TAF SITES ACROSS SOUTH FLORIDA
SHOULD REMAIN DRY TONIGHT. THE SHOWERS WILL COME BACK INTO PLAY AT
ALL OF THE TAF SITES BETWEEN 12Z AND 16Z ON SATURDAY...BEFORE
THUNDERSTORMS DEVELOP FOR THE AFTERNOON HOURS ON SATURDAY. SO WILL
HAVE A VCSH FROM 12Z UNTIL 16Z AND THEN VCTS AFTER 16Z SATURDAY
FOR ALL TAF SITES OVER SOUTH FLORIDA.
THE WIND SPEEDS TONIGHT AT ALL OF THE TAF SITES WILL DECREASE FROM
5 TO 10 KNOTS THIS EVENING TO LESS THAN 5 KNOTS AFTER 03Z MAINLY
FROM THE SOUTH TO SOUTHWEST DIRECTION. THE ONLY EXCEPTION TO THIS
IS AT KAPF WHERE THE WINDS WILL BE FROM THE SOUTHEAST DIRECTION.
THE WINDS WILL THEN INCREASE ON SATURDAY MORNING TO AROUND 10
KNOTS FROM THE SOUTHEAST...WITH KAPF TAF SITE SWINGING TO A
SOUTHWEST DIRECTION AFTER 16Z SATURDAY.
THE VIS SHOULD REMAIN IN THE VFR CONDITIONS TONIGHT INTO SATURDAY
AT ALL OF THE TAF SITES...EXCEPT FOR KPBI...KFLL...KFXE...AND KAPF
TAF SITES WITH THE CEILING TO FALL DOWN INTO THE MVFR CONDITIONS
BETWEEN 10Z AND 13Z TONIGHT. THE REASON FOR THIS IS FOR POSSIBLE
FOG DEVELOP OVER THE INTERIOR AREAS THAT COULD WORK INTO THESE TAF
SITES.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 230 PM EDT FRI APR 12 2013/
SHORT TERM (TONIGHT-SUNDAY NIGHT)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED PLENTY OF MID/UPPER
MOISTURE SPREADING NORTHEAST ACROSS THE FLORIDA PENINSULA WITHIN THE
SOUTHWEST UPPER FLOW AND A WEAK RIDGE AXIS EXTENDING NORTH OVER THE
BAHAMAS. THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTH AND SOUTHWEST ACROSS THE FLORIDA BIG BEND TO THE CENTRAL GULF
OF MEXICO WITH MOIST SOUTHERLY FLOW ACROSS THE FLORIDA PENINSULA
AHEAD OF IT. THE LATEST SHORT-RANGE FORECAST GUIDANCE REMAINS IN
GOOD AGREEMENT AND SHOWS THIS FRONTAL BOUNDARY CONTINUING EASTWARD
TOWARD AND INTO CENTRAL FLORIDA LATER THIS EVENING THROUGH TONIGHT
BEFORE STALLING AROUND OR JUST NORTH OF THE LAKE THROUGH THE DAY
SATURDAY. PLENTY OF DEEP LAYER MOISTURE AND SOUTHWEST DEEP LAYER
FLOW COMBINED WITH DAYTIME HEATING AND AFTERNOON SEA BREEZES WILL
SUPPORT SCATTERED SHOWERS AND STORMS THROUGH SATURDAY.
FOR THE REMAINDER OF THE AFTERNOON AND EVENING TODAY...THE BEST
CHANCE FOR THESE STORMS WILL REMAIN OVER THE NORTHERN AND EASTERN
SECTIONS OF THE AREA...ESPECIALLY OVER PALM BEACH/BROWARD COUNTIES.
THE LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THE CURRENT
TRENDS AND INDICATE THE AFTERNOON CONVECTION BECOMING CONCENTRATED
OVER THE EAST COAST METRO AND COASTAL LOCATIONS FROM BROWARD TO PALM
BEACH COUNTIES THROUGH SUNSET...THEN TRENDING DOWN THROUGH
MID/LATE-EVENING PERIODS. CONSIDERING THE MOIST PROFILES IN
PLACE...THE MAIN IMPACTS WITH THESE STORMS TODAY WILL BE WET
MICROBURSTS AND HEAVY RAINFALL. ADDITIONALLY...LOCALIZED FLOODING
CAN`T BE RULED OUT IN THE AREAS WHERE THIS ACTIVITY SETS UP.
ON SATURDAY...ANOTHER POTENTIALLY ACTIVE DAY IS ANTICIPATED DUE TO A
COMBINATION OF DEEP LAYER MOISTURE...DAYTIME HEATING/INSTABILITY AND
THE FRONTAL BOUNDARY IN THE VICINITY OF THE AREA. THIS BOUNDARY
ALONG WITH THE AFTERNOON SEA BREEZE WILL BE THE FOCUS AREAS FOR
AFTERNOON CONVECTION. THE LATEST MODEL GUIDANCE DOES INDICATE MORE
OF A SOUTHERLY FLOW UP TO 700MB THROUGH THIS PERIOD TOMORROW...WHICH
MAY RESULT IN THE AFTERNOON ACTIVITY BECOMING CONCENTRATED GENERALLY
OVER THE NORTHERN 1/3 OF THE FORECAST AREA OR AROUND THE LAKE
REGION. SATURDAY NIGHT THROUGH SUNDAY NIGHT...THIS BOUNDARY WILL
CONTINUE TO DIMINISH AND BEGIN TO LIFT BACK TO THE NORTH AS A
SHORTWAVE TROUGH LIFTS NORTHEAST OVER THE CENTRAL GULF COAST REGION.
SOUTHEAST LOW-LEVEL FLOW WILL BE EXPECTED SUNDAY WITH THE BEST
CHANCE OF AFTERNOON SHOWERS/STORMS OVER THE NWRN 1/3 OF THE FORECAST
AREA OR FROM NAPLES TO THE LAKE.
LONG TERM (MONDAY-FRIDAY)...
MOSTLY QUIET WEATHER CONDITIONS WILL BE EXPECTED AS DEEP LAYER
RIDGING REMAINS AS THE DOMINANT SYNOPTIC FEATURE THROUGH THE
MID-WEEK TIME FRAME. LATER IN THE WEEK...THE MODELS REMAIN IN DECENT
AGREEMENT...OUTSIDE OF SOME MINOR TIMING DIFFERENCES...AND GENERALLY
SHOW ANOTHER FRONTAL BOUNDARY APPROACHING AND MOVING OVER THE STATE.
IF THE MODELS REMAIN PERSISTENT WITH THIS FEATURE OVER THE WEEKEND
AND INTO THE UPCOMING WEEK...EXPECT THE EXTENDED RANGE RAINFALL
CHANCES TO STEADILY INCREASE AS CONFIDENCE RISES. OTHERWISE...QUIET
CONDITIONS WILL CONTINUE THROUGH THE WEEK WITH TEMPERATURES
REMAINING ABOVE NORMAL WITH THE MOIST SOUTHERLY FLOW IN PLACE. THE
BEST CHANCE FOR AFTERNOON SHOWERS OR STORMS WILL REMAIN INLAND FROM
NAPLES TO THE LAKE.
MARINE...
MODERATE SOUTHERLY WINDS WILL PERSIST INTO THE WEEKEND AS A COLD
FRONT APPROACHES AND STALLS JUST NORTH OF THE SOUTH FLORIDA WATERS
SATURDAY. SCATTERED SHOWERS AND A FEW STORMS WILL BE EXPECTED
THROUGH SATURDAY AS THE FRONT APPROACHES AND STALLS JUST NORTH OF
THE AREA. THIS FRONTAL BOUNDARY WILL DIMINISH OVER THE WEEKEND AND
INTO THE UPCOMING WEEK WITH HIGH PRESSURE EXPECTED TO BUILD BACK
OVER THE AREA NEXT WEEK.
FIRE WEATHER...
PLENTY OF MOISTURE ALONG WITH INCREASING RAIN CHANCES WILL PRECLUDE
ANY CHANCE FOR CRITICAL FIRE WEATHER CONDITIONS THROUGH THE WEEKEND
AS A COLD FRONT APPROACHES AND STALLS AROUND THE LAKE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 84 71 83 / 30 50 20 20
FORT LAUDERDALE 74 85 73 84 / 20 50 20 20
MIAMI 73 86 72 84 / 20 40 20 20
NAPLES 72 83 70 86 / 20 40 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS MIAMI FL
230 PM EDT FRI APR 12 2013
.SHORT TERM (TONIGHT-SUNDAY NIGHT)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED PLENTY OF MID/UPPER
MOISTURE SPREADING NORTHEAST ACROSS THE FLORIDA PENINSULA WITHIN THE
SOUTHWEST UPPER FLOW AND A WEAK RIDGE AXIS EXTENDING NORTH OVER THE
BAHAMAS. THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTH AND SOUTHWEST ACROSS THE FLORIDA BIG BEND TO THE CENTRAL GULF
OF MEXICO WITH MOIST SOUTHERLY FLOW ACROSS THE FLORIDA PENINSULA
AHEAD OF IT. THE LATEST SHORT-RANGE FORECAST GUIDANCE REMAINS IN
GOOD AGREEMENT AND SHOWS THIS FRONTAL BOUNDARY CONTINUING EASTWARD
TOWARD AND INTO CENTRAL FLORIDA LATER THIS EVENING THROUGH TONIGHT
BEFORE STALLING AROUND OR JUST NORTH OF THE LAKE THROUGH THE DAY
SATURDAY. PLENTY OF DEEP LAYER MOISTURE AND SOUTHWEST DEEP LAYER
FLOW COMBINED WITH DAYTIME HEATING AND AFTERNOON SEA BREEZES WILL
SUPPORT SCATTERED SHOWERS AND STORMS THROUGH SATURDAY.
FOR THE REMAINDER OF THE AFTERNOON AND EVENING TODAY...THE BEST
CHANCE FOR THESE STORMS WILL REMAIN OVER THE NORTHERN AND EASTERN
SECTIONS OF THE AREA...ESPECIALLY OVER PALM BEACH/BROWARD COUNTIES.
THE LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THE CURRENT
TRENDS AND INDICATE THE AFTERNOON CONVECTION BECOMING CONCENTRATED
OVER THE EAST COAST METRO AND COASTAL LOCATIONS FROM BROWARD TO PALM
BEACH COUNTIES THROUGH SUNSET...THEN TRENDING DOWN THROUGH
MID/LATE-EVENING PERIODS. CONSIDERING THE MOIST PROFILES IN
PLACE...THE MAIN IMPACTS WITH THESE STORMS TODAY WILL BE WET
MICROBURSTS AND HEAVY RAINFALL. ADDITIONALLY...LOCALIZED FLOODING
CAN`T BE RULED OUT IN THE AREAS WHERE THIS ACTIVITY SETS UP.
ON SATURDAY...ANOTHER POTENTIALLY ACTIVE DAY IS ANTICIPATED DUE TO A
COMBINATION OF DEEP LAYER MOISTURE...DAYTIME HEATING/INSTABILITY AND
THE FRONTAL BOUNDARY IN THE VICINITY OF THE AREA. THIS BOUNDARY
ALONG WITH THE AFTERNOON SEA BREEZE WILL BE THE FOCUS AREAS FOR
AFTERNOON CONVECTION. THE LATEST MODEL GUIDANCE DOES INDICATE MORE
OF A SOUTHERLY FLOW UP TO 700MB THROUGH THIS PERIOD TOMORROW...WHICH
MAY RESULT IN THE AFTERNOON ACTIVITY BECOMING CONCENTRATED GENERALLY
OVER THE NORTHERN 1/3 OF THE FORECAST AREA OR AROUND THE LAKE
REGION. SATURDAY NIGHT THROUGH SUNDAY NIGHT...THIS BOUNDARY WILL
CONTINUE TO DIMINISH AND BEGIN TO LIFT BACK TO THE NORTH AS A
SHORTWAVE TROUGH LIFTS NORTHEAST OVER THE CENTRAL GULF COAST REGION.
SOUTHEAST LOW-LEVEL FLOW WILL BE EXPECTED SUNDAY WITH THE BEST
CHANCE OF AFTERNOON SHOWERS/STORMS OVER THE NWRN 1/3 OF THE FORECAST
AREA OR FROM NAPLES TO THE LAKE.
.LONG TERM (MONDAY-FRIDAY)...
MOSTLY QUIET WEATHER CONDITIONS WILL BE EXPECTED AS DEEP LAYER
RIDGING REMAINS AS THE DOMINANT SYNOPTIC FEATURE THROUGH THE
MID-WEEK TIME FRAME. LATER IN THE WEEK...THE MODELS REMAIN IN DECENT
AGREEMENT...OUTSIDE OF SOME MINOR TIMING DIFFERENCES...AND GENERALLY
SHOW ANOTHER FRONTAL BOUNDARY APPROACHING AND MOVING OVER THE STATE.
IF THE MODELS REMAIN PERSISTENT WITH THIS FEATURE OVER THE WEEKEND
AND INTO THE UPCOMING WEEK...EXPECT THE EXTENDED RANGE RAINFALL
CHANCES TO STEADILY INCREASE AS CONFIDENCE RISES. OTHERWISE...QUIET
CONDITIONS WILL CONTINUE THROUGH THE WEEK WITH TEMPERATURES
REMAINING ABOVE NORMAL WITH THE MOIST SOUTHERLY FLOW IN PLACE. THE
BEST CHANCE FOR AFTERNOON SHOWERS OR STORMS WILL REMAIN INLAND FROM
NAPLES TO THE LAKE.
&&
.MARINE...
MODERATE SOUTHERLY WINDS WILL PERSIST INTO THE WEEKEND AS A COLD
FRONT APPROACHES AND STALLS JUST NORTH OF THE SOUTH FLORIDA WATERS
SATURDAY. SCATTERED SHOWERS AND A FEW STORMS WILL BE EXPECTED
THROUGH SATURDAY AS THE FRONT APPROACHES AND STALLS JUST NORTH OF
THE AREA. THIS FRONTAL BOUNDARY WILL DIMINISH OVER THE WEEKEND AND
INTO THE UPCOMING WEEK WITH HIGH PRESSURE EXPECTED TO BUILD BACK
OVER THE AREA NEXT WEEK.
&&
.FIRE WEATHER...
PLENTY OF MOISTURE ALONG WITH INCREASING RAIN CHANCES WILL PRECLUDE
ANY CHANCE FOR CRITICAL FIRE WEATHER CONDITIONS THROUGH THE WEEKEND
AS A COLD FRONT APPROACHES AND STALLS AROUND THE LAKE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 84 72 83 / 20 50 20 20
FORT LAUDERDALE 74 84 74 83 / 20 50 20 20
MIAMI 74 84 74 83 / 20 40 20 20
NAPLES 70 82 69 83 / 20 40 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION
NWS MIAMI FL
139 PM EDT THU APR 11 2013
.AVIATION...
A SCT/BKN CLOUD DECK AT 20KFT WILL CONTINUE ACROSS THE TERMINALS...
WITH A FEW SHOWERS EMBEDDED. THESE SHOWERS WILL REMAIN CLOSE TO ONLY
KAPF...FOR THAT REASON KEPT THE VCSH AS PREVAILING FOR THAT SITE.
SOUTHEASTERLY FLOW WILL CONTINUE GUSTING UP TO 25 KTS AT ALL
TERMINALS THROUGH THE EVENING. WINDS WILL DECREASE IN SPEED
OVERNIGHT...AND WILL ONCE AGAIN PICK UP SPEED BY 12/15Z.
&&
.PREV DISCUSSION... /ISSUED 1002 AM EDT THU APR 11 2013/
UPDATE...
THE LATEST RUC 400 MB ANALYSIS OVERLAID ONTO THE LATEST WATER
VAPOR LOOP SHOWED A RIDGE AXIS EXTENDING NORTH AND NORTHEAST FROM THE
EASTERN GULF OF MEXICO TO NORTHERN FLORIDA AND GENERALLY INDICATES
THIS RIDGE BUILDING EASTWARD OVER THE LOCAL AREA THROUGH THE
COURSE OF THE DAY TODAY. MODEL SOUNDINGS REFLECT THIS AND INDICATE
A DECENT SUBSIDENCE INVERSION JUST ABOVE 500 MB FROM TBW TO MIA.
DESPITE THE STEEP LAPSE RATES NOTED IN THE SOUNDINGS FROM
600-500MB...THIS COULD BE A LIMITING FACTOR FOR DEEP CONVECTION
AND THE OVERALL THUNDERSTORM POTENTIAL THIS AFTERNOON/EARLY
EVENING. HOWEVER...IF THIS IS ERODED...A FEW STRONG STORMS WILL
BECOME A POSSIBILITY LATER TODAY. THESE LAPSE RATES COMBINED WITH
THE MID-LEVEL DRY AIR COULD RESULT IN STRONG WINDS AND SMALL HAIL
AS THE MAIN IMPACTS FROM ANY STRONG STORM THAT DOES DEVELOP.
CONSIDERING THE MEAN LOW-LEVEL FLOW IS SSE UP TO 700MB...THE BEST
CHANCE FOR THESE STORMS WILL REMAIN OVER THE NORTHERN SECTIONS OF
THE LOCAL AREA...ESPECIALLY FROM NAPLES TO THE LAKE REGION.
OUTSIDE OF A FEW MINOR TWEAKS WITHIN THE GRIDDED FORECAST BASED ON
THE MORNING OBSERVATIONS AROUND THE LOCAL AREA...NO MAJOR CHANGES
ARE ANTICIPATED. 85/AG
PREV DISCUSSION... /ISSUED 727 AM EDT THU APR 11 2013/
AVIATION...
VFR CONDITIONS THROUGH THE PERIOD AT ALL TERMINALS. HIGH PRESSURE
OVER THE WESTERN ATLANTIC WATERS WILL KEEP AN EASTERLY FLOW ACROSS
SOUTH FLORIDA TODAY...GUSTING UP TO 20 KTS AT TIMES. A FEW SHOWERS
COULD DEVELOP AND MOVE NEAR THE TERMINALS...BUT COVERAGE AND
LENGTH WILL BE NOT SIGNIFICANT THEREFORE...NO NEED TO MENTION ON
TAFS AT THIS TIME. WILL AMEND IF NECESSARY. WINDS EXPECTED TO
DECREASE IN SPEED AT AROUND 12/02Z.
PREV DISCUSSION... /ISSUED 346 AM EDT THU APR 11 2013/
SHORT TERM...
WITH HIGH PRESSURE TO THE EAST OF SOUTH FLORIDA, A SOUTHEASTERLY
FLOW HAS BROUGHT PLENTY OF MOISTURE TO INITIATE SOME AFTERNOON
THUNDERSTORMS ONCE AGAIN TODAY. THESE STORMS WILL MAINLY BE IN THE
LAKE REGION ONCE AGAIN. IN TERMS OF DYNAMICS, THERE WILL BE 500MB
VORTICITY ADVECTION MOVING ACROSS THE AREA. MODELS INDICATE
BETWEEN 600 AND 1000 JOULES OF CAPE. TYPICAL NEGATIVE LIS, AND
STRONG 500MB OMEGA VALUES. THE 700 MB OMEGAS ARE LESS THAN
YESTERDAY. THE 500MB RIDGE IS BREAKING DOWN, AND THERE WILL BE A
WEAK SHORT WAVE. JET SUPPORT TODAY WILL BE NEGLIGIBLE. SO, HAVE
KEPT CHC POPS OVER THE NORTHWEST AREA, DOWN TO ABOUT I75. IT DOES
LOOK TO BE SOMEWHAT MORE COVERAGE TODAY. ALSO, WHILE THERE WILL BE
SOMEWHAT OF A SEA BREEZE, IT MAY BE HARD TO DETECT AT THE SFC AS
WINDS WILL BE BREEZY TODAY.
TOMORROW WILL SEE A SIMILAR SETUP, EXCEPT TRANSLATED EASTWARD.
ALSO, WINDS TOMORROW WILL TURN MORE SOUTHERLY AND PERHAPS EVEN
MORE SOUTHWESTERLY.
HIGH TEMPERATURES FOR THE NEXT COUPLE OF DAYS WILL CONTINUE TO BE
IN THE MID TO UPPER 80S, TO AROUND 90. LOW TEMPERATURES WILL BE
FAIRLY WARM, WITH LOWS IN THE MID TO UPPER 60S IN THE INTERIOR AND
LOW TO MID 70S ALONG THE COASTAL AREAS.
CONDITIONS WILL BECOME MORE INTERESTING BY SATURDAY MORNING. A LOW
PRESSURE SYSTEM OVER THE PLAINS WILL MOVE EASTWARDS FOR THIS
WEEKEND. THIS SYSTEM WILL BRING A COLD FRONT TO THE FLORIDA
PENINSULA. THE FRONT IS CURRENTLY PROGGED TO STALL JUST NORTH OF
LAKE OKEECHOBEE. THIS WILL KEEP SOUTH FLORIDA IN THE WARM SECTOR
ON SATURDAY. THE MAIN ENERGY ASSOCIATED WITH THE FRONT WILL BE
WELL TO THE NORTH. THERE WILL NOT BE MUCH IN THE WAY OF ANYTHING
FOR SOUTH FLORIDA, EXCEPT INCREASING THE CHANCE FOR THUNDERSTORMS
SATURDAY AFTERNOON. THE AREA OF HIGHER POPS WILL GENERALLY BE
NORTH OF I75, AND HIGHER AS YOU GO NORTH, GETTING CLOSER TO THE
FRONTAL BOUNDARY. IT IS STILL FAR ENOUGH OUT THAT THE CHANCES WILL
CHANGE FOR ANY GIVEN AREA, UP OR DOWN, DEPENDING ON HOW FAR SOUTH
THE FRONT CAN GET. FOR NOW, DID NOT GO ABOVE 50 POPS FOR SATURDAY
AFTERNOON.
LONG TERM...
THE STALLED FRONT WILL SIT AROUND FOR A COUPLE OF DAYS AFTER,
MAKING LITTLE PROGRESS AND SHOULD EVENTUALLY WASH OUT, PROBABLY
FOR THE BEGINNING OF THE WEEK. AS IT DOES WASH OUT, HIGH PRESSURE
WILL AGAIN BRING A SOUTH TO SOUTHEASTERLY FLOW TO SOUTH FLORIDA,
ALLOWING FOR A CHANCE OF A FEW AFTERNOON THUNDERSTORMS TO POPS UP.
MODELS ARE INDICATING A SHORT WAVE MOVING ACROSS NORTH AND
CENTRAL FLORIDA SUNDAY NIGHT, BUT CURRENTLY THINKING IT WILL NOT
AFFECT THE CWA. SO, ONCE THE FRONT WASHES OUT, NOT EXPECTING ANY
REAL PATTERN CHANGE FOR THE REMAINDER OF THE FORECAST PERIOD. HIGH
TEMPERATURES WILL CONTINUE TO RANGE FROM THE LOW TO MID 80S ALONG
THE COAST TO MID TO UPPER 80S, POSSIBLY EVEN LOW 90S IN THE
INTERIOR OF THE STATE.
MARINE...
HIGH PRESSURE WILL REMAIN TO THE EAST OF THE AREA. THIS WILL BRING
CONTINUOUS STIFF SOUTHEAST WINDS OF 15 TO 20KTS TODAY. THEY WILL
BEGIN TO TURN MORE SOUTHERLY TOMORROW, BUT WILL CONTINUE TO BE
FAIRLY STIFF, ALTHOUGH SLIGHTLY LOWER TOMORROW. THERE IS A SLIGHT
CHANCE OF A SHOWER THROUGH TONIGHT AND POSSIBLE A SHOWER OR A
THUNDERSTORM TOMORROW. A WEAK COLD FRONT WILL STALL OVER THE AREA
SATURDAY, BRINGING AN INCREASED CHANCE OF A SHOWER AND/OR A
THUNDERSTORM FOR SATURDAY AFTERNOON.
FIRE WEATHER...
FIRE WEATHER CONCERNS ARE AT A LOW RIGHT NOW AS THERE IS PLENTY OF
SURFACE MOISTURE AROUND. IT WILL BE BREEZY TODAY, WITH WINDS OUT
OF THE SOUTHEAST. THERE IS A CHANCE OF A THUNDERSTORM IN THE
INTERIOR AREAS, ESPECIALLY NORTH, TOWARDS LAKE OKEECHOBEE. THIS
WILL REPEAT AGAIN TOMORROW, EXCEPT WINDS WILL BE MORE SOUTHERLY.
THEN, FOR THE WEEKEND, A COLD FRONT WILL APPROACH SOUTH FLORIDA,
BUT IS NOT EXPECTED TO MAKE IT INTO THE AREA. MODELS ARE SHOWING
IT TO STALL OVER CENTRAL FLORIDA. BUT, IT WILL INCREASE THE CHANCE
FOR THUNDERSTORMS ON SATURDAY AFTERNOON, AND MAYBE ON SUNDAY
AFTERNOON, BEFORE WASHING OUT. WITH WINDS JUST ABOVE THE SURFACE
OF AROUND 15 TO 20 MPH, NOT EXPECTING FOG FORMATION TONIGHT.
HOWEVER, WINDS ARE LOOKING AS THEY MAY DIMINISH AS THE FRONT
STALLS, WHICH MAY ALLOW FOG FOR SATURDAY AND SUNDAY MORNINGS.
PREV DISCUSSION... /ISSUED 143 AM EDT THU APR 11 2013/
AVIATION...
HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC WATERS
TODAY...AS LOW PRESSURE MOVES THROUGH THE GREAT LAKES. THIS WILL
ALLOW FOR A BREEZY TO WINDY SOUTHEAST WIND FLOW OVER THE SOUTH
FLORIDA TAF SITES TONIGHT WITH SPEEDS BETWEEN 15 TO 20 KNOTS WITH
GUSTS UP TO 28 KTS. THE SOUTHEAST WIND FLOW WILL CONTINUE
TONIGHT...BUT THE SPEEDS WILL DECREASE TO 10 KNOTS OR LESS AT THE
TAF SITES OVER SOUTH FLORIDA.
THE EAST COAST TAF SITES COULD SEE A SHOWER OR TWO ON THE
SOUTHEAST WIND FLOW TODAY...BUT THE COVERAGE AND DURATION WILL BE
FEW AND FAR BETWEEN. SO WILL LEAVE THE EAST COAST TAF SITES DRY AT
THIS TIME FOR TODAY INTO TONIGHT. KAPF TAF SITE COULD SEE SOME
SHOWERS IN THE AREA WITH MORE COVERAGE. SO HAVE ADDED VCSH TO KAPF
TAF SITE AFTER 15Z FOR TODAY.
THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS FOR
TODAY INTO TONIGHT FOR ALL OF THE TAF SITES.
AVIATION...54/BNB
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 84 72 84 / 20 40 20 50
FORT LAUDERDALE 75 84 74 84 / 20 30 20 50
MIAMI 74 85 74 85 / 20 30 20 50
NAPLES 71 83 70 83 / 20 20 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR COASTAL
BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS MIAMI FL
1002 AM EDT THU APR 11 2013
.UPDATE...
THE LATEST RUC 400 MB ANALYSIS OVERLAID ONTO THE LATEST WATER
VAPOR LOOP SHOWED A RIDGE AXIS EXTENDING NORTH AND NORTHEAST FROM THE
EASTERN GULF OF MEXICO TO NORTHERN FLORIDA AND GENERALLY INDICATES
THIS RIDGE BUILDING EASTWARD OVER THE LOCAL AREA THROUGH THE
COURSE OF THE DAY TODAY. MODEL SOUNDINGS REFLECT THIS AND INDICATE
A DECENT SUBSIDENCE INVERSION JUST ABOVE 500 MB FROM TBW TO MIA.
DESPITE THE STEEP LAPSE RATES NOTED IN THE SOUNDINGS FROM
600-500MB...THIS COULD BE A LIMITING FACTOR FOR DEEP CONVECTION
AND THE OVERALL THUNDERSTORM POTENTIAL THIS AFTERNOON/EARLY
EVENING. HOWEVER...IF THIS IS ERODED...A FEW STRONG STORMS WILL
BECOME A POSSIBILITY LATER TODAY. THESE LAPSE RATES COMBINED WITH
THE MID-LEVEL DRY AIR COULD RESULT IN STRONG WINDS AND SMALL HAIL
AS THE MAIN IMPACTS FROM ANY STRONG STORM THAT DOES DEVELOP.
CONSIDERING THE MEAN LOW-LEVEL FLOW IS SSE UP TO 700MB...THE BEST
CHANCE FOR THESE STORMS WILL REMAIN OVER THE NORTHERN SECTIONS OF
THE LOCAL AREA...ESPECIALLY FROM NAPLES TO THE LAKE REGION.
OUTSIDE OF A FEW MINOR TWEAKS WITHIN THE GRIDDED FORECAST BASED ON
THE MORNING OBSERVATIONS AROUND THE LOCAL AREA...NO MAJOR CHANGES
ARE ANTICIPATED. 85/AG
&&
.PREV DISCUSSION... /ISSUED 727 AM EDT THU APR 11 2013/
AVIATION...
VFR CONDITIONS THROUGH THE PERIOD AT ALL TERMINALS. HIGH PRESSURE
OVER THE WESTERN ATLANTIC WATERS WILL KEEP AN EASTERLY FLOW ACROSS
SOUTH FLORIDA TODAY...GUSTING UP TO 20 KTS AT TIMES. A FEW SHOWERS
COULD DEVELOP AND MOVE NEAR THE TERMINALS...BUT COVERAGE AND
LENGTH WILL BE NOT SIGNIFICANT THEREFORE...NO NEED TO MENTION ON
TAFS AT THIS TIME. WILL AMEND IF NECESSARY. WINDS EXPECTED TO
DECREASE IN SPEED AT AROUND 12/02Z.
PREV DISCUSSION... /ISSUED 346 AM EDT THU APR 11 2013/
SHORT TERM...
WITH HIGH PRESSURE TO THE EAST OF SOUTH FLORIDA, A SOUTHEASTERLY
FLOW HAS BROUGHT PLENTY OF MOISTURE TO INITIATE SOME AFTERNOON
THUNDERSTORMS ONCE AGAIN TODAY. THESE STORMS WILL MAINLY BE IN THE
LAKE REGION ONCE AGAIN. IN TERMS OF DYNAMICS, THERE WILL BE 500MB
VORTICITY ADVECTION MOVING ACROSS THE AREA. MODELS INDICATE
BETWEEN 600 AND 1000 JOULES OF CAPE. TYPICAL NEGATIVE LIS, AND
STRONG 500MB OMEGA VALUES. THE 700 MB OMEGAS ARE LESS THAN
YESTERDAY. THE 500MB RIDGE IS BREAKING DOWN, AND THERE WILL BE A
WEAK SHORT WAVE. JET SUPPORT TODAY WILL BE NEGLIGIBLE. SO, HAVE
KEPT CHC POPS OVER THE NORTHWEST AREA, DOWN TO ABOUT I75. IT DOES
LOOK TO BE SOMEWHAT MORE COVERAGE TODAY. ALSO, WHILE THERE WILL BE
SOMEWHAT OF A SEA BREEZE, IT MAY BE HARD TO DETECT AT THE SFC AS
WINDS WILL BE BREEZY TODAY.
TOMORROW WILL SEE A SIMILAR SETUP, EXCEPT TRANSLATED EASTWARD.
ALSO, WINDS TOMORROW WILL TURN MORE SOUTHERLY AND PERHAPS EVEN
MORE SOUTHWESTERLY.
HIGH TEMPERATURES FOR THE NEXT COUPLE OF DAYS WILL CONTINUE TO BE
IN THE MID TO UPPER 80S, TO AROUND 90. LOW TEMPERATURES WILL BE
FAIRLY WARM, WITH LOWS IN THE MID TO UPPER 60S IN THE INTERIOR AND
LOW TO MID 70S ALONG THE COASTAL AREAS.
CONDITIONS WILL BECOME MORE INTERESTING BY SATURDAY MORNING. A LOW
PRESSURE SYSTEM OVER THE PLAINS WILL MOVE EASTWARDS FOR THIS
WEEKEND. THIS SYSTEM WILL BRING A COLD FRONT TO THE FLORIDA
PENINSULA. THE FRONT IS CURRENTLY PROGGED TO STALL JUST NORTH OF
LAKE OKEECHOBEE. THIS WILL KEEP SOUTH FLORIDA IN THE WARM SECTOR
ON SATURDAY. THE MAIN ENERGY ASSOCIATED WITH THE FRONT WILL BE
WELL TO THE NORTH. THERE WILL NOT BE MUCH IN THE WAY OF ANYTHING
FOR SOUTH FLORIDA, EXCEPT INCREASING THE CHANCE FOR THUNDERSTORMS
SATURDAY AFTERNOON. THE AREA OF HIGHER POPS WILL GENERALLY BE
NORTH OF I75, AND HIGHER AS YOU GO NORTH, GETTING CLOSER TO THE
FRONTAL BOUNDARY. IT IS STILL FAR ENOUGH OUT THAT THE CHANCES WILL
CHANGE FOR ANY GIVEN AREA, UP OR DOWN, DEPENDING ON HOW FAR SOUTH
THE FRONT CAN GET. FOR NOW, DID NOT GO ABOVE 50 POPS FOR SATURDAY
AFTERNOON.
LONG TERM...
THE STALLED FRONT WILL SIT AROUND FOR A COUPLE OF DAYS AFTER,
MAKING LITTLE PROGRESS AND SHOULD EVENTUALLY WASH OUT, PROBABLY
FOR THE BEGINNING OF THE WEEK. AS IT DOES WASH OUT, HIGH PRESSURE
WILL AGAIN BRING A SOUTH TO SOUTHEASTERLY FLOW TO SOUTH FLORIDA,
ALLOWING FOR A CHANCE OF A FEW AFTERNOON THUNDERSTORMS TO POPS UP.
MODELS ARE INDICATING A SHORT WAVE MOVING ACROSS NORTH AND
CENTRAL FLORIDA SUNDAY NIGHT, BUT CURRENTLY THINKING IT WILL NOT
AFFECT THE CWA. SO, ONCE THE FRONT WASHES OUT, NOT EXPECTING ANY
REAL PATTERN CHANGE FOR THE REMAINDER OF THE FORECAST PERIOD. HIGH
TEMPERATURES WILL CONTINUE TO RANGE FROM THE LOW TO MID 80S ALONG
THE COAST TO MID TO UPPER 80S, POSSIBLY EVEN LOW 90S IN THE
INTERIOR OF THE STATE.
MARINE...
HIGH PRESSURE WILL REMAIN TO THE EAST OF THE AREA. THIS WILL BRING
CONTINUOUS STIFF SOUTHEAST WINDS OF 15 TO 20KTS TODAY. THEY WILL
BEGIN TO TURN MORE SOUTHERLY TOMORROW, BUT WILL CONTINUE TO BE
FAIRLY STIFF, ALTHOUGH SLIGHTLY LOWER TOMORROW. THERE IS A SLIGHT
CHANCE OF A SHOWER THROUGH TONIGHT AND POSSIBLE A SHOWER OR A
THUNDERSTORM TOMORROW. A WEAK COLD FRONT WILL STALL OVER THE AREA
SATURDAY, BRINGING AN INCREASED CHANCE OF A SHOWER AND/OR A
THUNDERSTORM FOR SATURDAY AFTERNOON.
FIRE WEATHER...
FIRE WEATHER CONCERNS ARE AT A LOW RIGHT NOW AS THERE IS PLENTY OF
SURFACE MOISTURE AROUND. IT WILL BE BREEZY TODAY, WITH WINDS OUT
OF THE SOUTHEAST. THERE IS A CHANCE OF A THUNDERSTORM IN THE
INTERIOR AREAS, ESPECIALLY NORTH, TOWARDS LAKE OKEECHOBEE. THIS
WILL REPEAT AGAIN TOMORROW, EXCEPT WINDS WILL BE MORE SOUTHERLY.
THEN, FOR THE WEEKEND, A COLD FRONT WILL APPROACH SOUTH FLORIDA,
BUT IS NOT EXPECTED TO MAKE IT INTO THE AREA. MODELS ARE SHOWING
IT TO STALL OVER CENTRAL FLORIDA. BUT, IT WILL INCREASE THE CHANCE
FOR THUNDERSTORMS ON SATURDAY AFTERNOON, AND MAYBE ON SUNDAY
AFTERNOON, BEFORE WASHING OUT. WITH WINDS JUST ABOVE THE SURFACE
OF AROUND 15 TO 20 MPH, NOT EXPECTING FOG FORMATION TONIGHT.
HOWEVER, WINDS ARE LOOKING AS THEY MAY DIMINISH AS THE FRONT
STALLS, WHICH MAY ALLOW FOG FOR SATURDAY AND SUNDAY MORNINGS.
PREV DISCUSSION... /ISSUED 143 AM EDT THU APR 11 2013/
AVIATION...
HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC WATERS
TODAY...AS LOW PRESSURE MOVES THROUGH THE GREAT LAKES. THIS WILL
ALLOW FOR A BREEZY TO WINDY SOUTHEAST WIND FLOW OVER THE SOUTH
FLORIDA TAF SITES TONIGHT WITH SPEEDS BETWEEN 15 TO 20 KNOTS WITH
GUSTS UP TO 28 KTS. THE SOUTHEAST WIND FLOW WILL CONTINUE
TONIGHT...BUT THE SPEEDS WILL DECREASE TO 10 KNOTS OR LESS AT THE
TAF SITES OVER SOUTH FLORIDA.
THE EAST COAST TAF SITES COULD SEE A SHOWER OR TWO ON THE
SOUTHEAST WIND FLOW TODAY...BUT THE COVERAGE AND DURATION WILL BE
FEW AND FAR BETWEEN. SO WILL LEAVE THE EAST COAST TAF SITES DRY AT
THIS TIME FOR TODAY INTO TONIGHT. KAPF TAF SITE COULD SEE SOME
SHOWERS IN THE AREA WITH MORE COVERAGE. SO HAVE ADDED VCSH TO KAPF
TAF SITE AFTER 15Z FOR TODAY.
THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS FOR
TODAY INTO TONIGHT FOR ALL OF THE TAF SITES.
AVIATION...54/BNB
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 73 84 72 / 20 20 40 20
FORT LAUDERDALE 83 75 84 74 / 20 20 30 20
MIAMI 83 74 85 74 / 20 20 30 20
NAPLES 84 71 83 70 / 20 20 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR COASTAL
BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1253 AM CDT THU APR 11 2013
.MESOSCALE DISCUSSION...
655 PM CDT
A CONTINUED INCREASE IN CONVECTION IS EXPECTED ACROSS CENTRAL IL
PROGRESSING NORTHEAST INTO THE FORECAST AREA...WITH A CHANCE FOR
RAINFALL EXCEEDING FLOOD GUIDANCE IN SOME AREAS...ALONG WITH THE
SLIGHT RISK OF A SEVERE STORM OR TWO...ESPECIALLY ACROSS THE NEW
WATCH AREA.
LATEST HAND SURFACE ANALYSIS INDICATES THE SURFACE BOUNDARY
REMAINS STATIONARY FROM SOUTHWEST IL ENE THROUGH CENTRAL IN. THE
SURFACE LOW IN EAST CENTRAL MO CONTINUES TO EVOLVE NORTHEAST BUT
THE BOUNDARY SHOULD ADVANCE LITTLE NORTHWARD WITH REGENERATING
CONVECTION. WHILE STORMS HAD BEEN MAINLY FOCUSED ALONG THE
BOUNDARY IN CENTRAL IL DURING THE AFTERNOON...THE LAST HOUR TO TWO
HAS SHOWN A TREND FOR MUCH MORE DEVELOPMENT TO THE NORTH OF THAT
AS WARM AND MOIST ADVECTION IN THE LOW-LEVEL JET LAYER INCREASES.
IR IMAGERY CONTINUES TO SHOW COOLING CLOUD TOPS FROM THIS AREA OF
CONVECTION AS WELL AS THE LARGE BATCH IN MO TO FAR WEST CENTRAL
IL.
THIS LOW-LEVEL JET WILL CONTINUE TO INCREASE WITH IMPRESSIVE
MOISTURE TRANSPORT AND REPLENISHMENT ADVANCING NORTHWARD THROUGH
THE EVENING...ESPECIALLY BETWEEN 03Z AND 08Z. SHOWERS AND EMBEDDED
STORMS SHOULD BE PLENTIFUL IN THE CWA DURING THIS TIME. THIS LOW-
LEVEL JET INCREASE WILL ALL BE A RESULT OF MID TO UPPER LEVEL
FORCING AND DIFFLUENCE INCREASING WITH THE UPPER TROUGH ADVANCING
EASTWARD...AND ANOTHER LEAD SHORT WAVE NEAR THE KS/MO BORDER. THIS
SHORT WAVE AND ASSOCIATED 60 KT 700 MB FLOW SHOULD HELP TO SUSTAIN
MORE THAN EFFICIENT SHEAR TO ORGANIZE CONVECTION ON THE LOW-LEVEL
JET NOSE AND ELEVATED THERMAL BOUNDARY ACROSS THE SOUTHERN THIRD
TO HALF OF THE FORECAST AREA. ELEVATED INSTABILITY OF 500-1000
J/KG IS ANALYZED ACROSS THE SOUTH AND ADAPTING AN AMDAR SOUNDING
FOR RAP FORECAST 850 T/TDS AT 03Z INDICATES PARCELS SHOULD BE NEAR
THAT UPPER BOUND IN THE SOUTHERN FORECAST AREA. SOME OF THE
CONVECTIVE ALLOWING GUIDANCE DOES SHOW A FOCUSED CIRCULATION
/ALMOST MCV-LIKE/ ACROSS THE SOUTHERN AREA. WHILE NORTH OF THE
BOUNDARY BY QUITE A DISTANCE...THE EFFECTIVE SHEAR OF 50-70 KT
FORECAST BY THE RAP OVER THE FAR SOUTHERN CWA AND ADJACENT
COUNTIES IS SUFFICIENT FOR POTENTIAL BOWING STRUCTURES ABLE TO
PUSH WIND DOWN. WE DID SEE SOME OF THAT WITH A SIMILAR COMPLEX
THIS MORNING TOWARD ROCHELLE.
THE HEAVY RAIN THREAT CONTINUES WITH NOT ONLY HIGH MOISTURE
VALUES FOR EFFICIENT RAIN PRODUCERS /700 MB DEW POINTS NEAR
4C/...BUT FORECAST STORM MOTION FOR PRECIP TRAINING ALONG THE
ELEVATED STATIONARY BOUNDARY. SUCH BEHAVIOR HAS ALREADY BEEN
OBSERVED WITH SOME OF THE STORMS IN CENTRAL IL. AREAS IN THE FAR
SOUTHEAST DID RECEIVE A RADAR ESTIMATED ONE AND A HALF TO THREE
INCHES OF RAIN EARLIER AND ARE MORE VULNERABLE...WHICH IS WHERE
THE CURRENT FLOOD ADVISORY IS IN EFFECT. WILL BE KEEPING A CLOSE
EYE ON RAINFALL RATES BUT ALL IN ALL FORECAST QPF FROM EARLIER
STILL LOOKS ON TRACK...BASICALLY A WIDESPREAD ONE TO ONE AND A
HALF INCHES TONIGHT...WITH THE ISOLATED HIGHER AMOUNTS NAMELY
SOUTH OF I-80.
MTF
&&
.DISCUSSION...
358 PM CDT
SHORT TERM...LATE THIS AFTERNOON AND TONIGHT...
NEXT SHORT WAVE LIFTING UP THE E SIDE OF THE PLAINS UPPER TROF
IS MOVING NORTHEASTWARD OVER IA AT MID AFTERNOON. AS IT HAS BEEN
APPROACHING A BROAD AREA OF RAIN HAD SPREAD FAR AS SOUTHERN WI
AND N CENTRAL IL WHILE S OF THE SURFACE BOUNDARY...THAT HAD
RETREATED BACK TO CENTRAL IL THIS MORNING...THUNDERSTORMS HAD
BROKEN OUT. WHILE SOME OF THESE THUNDERSTORMS AND HEAVIER SHOWERS
WERE BEING CARRIER NE OVER THE FAR SOUTHERN PORTION OF THE LOCAL
FORECAST AREA BY THE MEAN FLOW THEY QUICKLY BECOME ELEVATED DUE
TO THE VERY STABLE BOUNDARY LAYER IN PLACE N OF SAID BOUNDARY.
DEW POINTS S OF THE BOUNDARY RISE ARE IN THE LOWER AND MID 60S
WITH UPPER 60S FURTHER S. WITH PARTLY CLOUD SKIES OVER ABOUT THE
S HALF OF IL IT HAS BECOME QUITE UNSTABLE DOWNSTATE AS TEMPS HAVE
WARMED. WITH THE SHORT WAVE NOTED ABOVE TO MOVE ESE THEN E OVER
SOUTHERN WI AND FAR NORTHERN IL DURING THE LATE AFTERNOON AND
VERY EARLY EVENING AS IT APPROACHES AND THEN TOPS THE UPPER RIDGE
DOWN STREAM FROM THE CENTRAL U.S. TROF RAIN COVERAGE IS EXPECTED
TO TEMPORARILY DECREASE FOR THE REST OF THE FIRST HALF OF THE
EVENING. THIS SHORT WAVE PASSING BY IS ALSO EXPECTED TO KEEP THE
QUASI-STATIONARY FRONT DOWN ACROSS CENTRAL IL OR EVEN GIVE IT A
SLIGHT NUDGE FURTHER S THIS EVENING.
AS WE GET INTO LATER THIS EVENING AND OVERNIGHT YET ANOTHER SHORT
WAVE...CURRENTLY LIFTING NE FROM FAR NE TX IS TO LIFT TO EASTERN
IA AND NORTHERN IL BY THU MORNING. AS IT MOVES CLOSER LATER
TONIGHT EXPECT ANOTHER BROAD AREA OF RAIN TO DEVELOP AND SPREAD
ACROSS THE FORECAST AREA. WHILE THE LATE AFTERNOON-EARLY EVENING
RAIN IS NOT EXPECTED TO HAVE MUCH IF ANY THUNDERSTORMS ASSOCIATED
WITH IT AS THE BOUNDARY LAYER WILL REMAIN VERY STABLE AND
TEMPERATURE PROFILES ALOFT DO NOT LOOK ESPECIALLY CONDUCIVE TO
UPDRAFT DEVELOPMENT THE RAIN LATER THIS EVENING AND OVERNIGHT WILL
LIKELY HAVE SOME EMBEDDED ELEVATED THUNDERSTORMS AS SOME MINOR
MID LEVEL COOLING OCCURS AS THE UPPER TROF MOVES SLOWLY EASTWARD
DURING THE NIGHT. EVEN WITHOUT CONVECTIVE UPDRAFTS TE OVERALL DEEP
STRONG UPWARD LIFT AS THE MAIN SYSTEM APPROACHES WILL LIKELY
SUPPORT PERIODS OF MODERATE RAIN.
THURSDAY AND FRIDAY...
BY THU MORNING THE UPPER LOW IS PROGGED TO STILL BE OVER THE MID
MO VALLEY WHILE THE ASSOCIATED SURFACE CIRCULATION IS OVER/NEAR
THE LOCAL FORECAST AREA. BY THIS TIME THE BETTER FORCING WILL HAVE
MOVED ON TO OVER WI AND THE WESTERN GREAT LAKES. WITH THE MID AND
UPPER LEVEL LOWS TO THE W AND ONLY GRADUALLY DRIFT E DURING THE
DAY TOMORROW THE THREAT OF ADDITIONAL SHOWERS WILL PERSIST INTO IF
OT THROUGH THU NIGHT BEFORE THE UPPER SYSTEM STARTS TO PULL SLOWLY
AWAY TO THE NE. WHILE MUCH OF THE SOUTHERN AND EASTERN PORTIONS OF
THE FA MAY BRIEFLY GET INTO THE WARM SECTOR AS THE LOW MOVES
ACROSS THE AREA ONCE IT DOES LOW LEVEL COLD AIR ADVECTION GETS
ESTABLISHED AS THE VERY COOL AIR CURRENTLY OVER THE UPPER MIDWEST
AND THE WESTERN GREAT LAKES GETS WRAPPED AROUND THE DEPARTING
SURFACE LOW. OVERNIGHT LOWS THU NIGHT/FRI MORNING LOOK TO BE QUITE
COOL WITH 30S ACROSS THE AREA...AND POSSIBLY GETTING DOWN TO
FREEZING IN THE NORTH CENTRAL WESTERN PART OF THE FA. SOME LIGHT
SHOWERS CANNOT BE RULED OUT WITH COLD CYCLONIC FLOW STILL OVER THE
REGION INTO FRI AS THE UPPER LOW IS VERY SLOW TO MOVE OFF TO THE
NE. THERE MAY EVEN BE SOME LIGHT SNOW SHOWERS DURING THE LATE THU
NIGHT INTO FRI DUE TO THE RELUCTANCE OF THE LOW AND ITS COLD
CYCLONIC LOW IS VERY RELUCTANT TO SPEED AWAY. WITH COLD AIR STILL
IN PLACE AND MOSTLY CLOUDY SKIES FRI MAX TEMPS ARE ONLY EXPECTED
TO BE IN THE LOWER AND MID 40S...WITH SOME UPPER 40S IN THE S
COUNTIES OF THE FA.
SAT AND SUN...
COOL CONDITIONS TO PERSIST SAT AS WE REMAIN UNDER NW FLOW THEN
MODERATING TEMPS FOR SUN AS THE OLD UPPER LOW FINALLY MOVES ACROSS
QUEBEC AND THE FLOW BACKS TO WSW. HOWEVER...ANOTHER UPPER
DISTURBANCE IS PROGGED TO BE MOVING EASTWARD FROM THE NORTHERN
ROCKIES AND NORTHERN HIGH PLAINS. RETURN FLOW WILL BE
INCREASING...RESULTING IN THE MODERATION IN TEMPS...BUT WILL ALSO
BE DRAWING GULF MOISTURE NORTHWARD WITH A THREAT OF RAIN.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* RAIN/ISOLATED TSRA ENDING BY 07Z.
* STRONG/GUSTY EASTERLY WINDS THIS MORNING...WITH A BRIEF PERIOD
OF STRONGER WINDS AFTER RAIN ENDS WITH GUSTS POSSIBLY AS HIGH AS
35 KTS.
* IFR CIGS INTO THIS AFTERNOON AND POSSIBLE AGAIN TONIGHT. LIFR
POSSIBLE AROUND SUNRISE.
* SHOWERS MID/LATE MORNING. CMS
//DISCUSSION...UPDATED 06Z...
BACK EDGE OF THE RAIN MAKING STEADY PROGRESS EASTWARD AND WILL
CLEAR CHICAGO AREA AROUND 07Z. COULD STILL BE SOME ISOLATED
THUNDER BEFORE THE RAIN ENDS...BUT THE STRONGEST STORMS AND THE
BULK THE LIGHTNING HAVE SHIFTED EAST. EXPECT AT LEAST A FEW HOURS
OF DRY WEATHER BEFORE ANOTHER WEAK WAVE ROTATES ACROSS THE AREA
LATER THIS MORNING...WHICH SHOULD PRODUCE AT LEAST SCATTERED
SHOWERS.
EASTERLY WINDS WILL REMAIN STRONG/GUSTY THROUGH SUNRISE AND BEGIN
TO SLOWLY DIMINISH LATER THIS MORNING AS SURFACE LOW PRESSURE
MOVES NORTH AND ELONGATES ACROSS THE REGION. BRIEF PERIOD OF
STRONGER WINDS OCCURRING...JUST BEHIND THE BACK EDGE OF THE
PRECIP WITH SQI AS HIGH AS 42KTS RECENTLY. THESE STRONGER WINDS
LIKELY ASSOCIATED WITH A WAKE LOW AND HAVE COVERED THESE STRONGER
WINDS WITH A TEMPO FOR NOW...THOUGH CONFIDENCE IS LOW REGARDING
SPECIFIC STRENGTHEN AND DURATION. WINDS WILL EVENTUALLY BECOME
SOUTH/SOUTHWEST LATER THIS AFTERNOON INTO THIS EVENING AS THE
SURFACE LOW DRIFTS NORTH...BUT SOME REFINEMENT WILL LIKELY BE
NEEDED WITH LATER FORECASTS FOR TIMING.
IFR CIGS WILL CONTINUE INTO THE MORNING HOURS AND LIFR CIGS MAY
DEVELOP AS THE LOW MOVES ACROSS THE AREA. AS THE LOW DRIFTS NORTH
LATER THIS AFTERNOON INTO THIS EVENING...EXPECT SOME IMPROVEMENT
WITH CIGS POSSIBLY LIFTING TO LOW MVFR. AS COLDER AIR SPREAD BACK
ACROSS THE REGION LATER TONIGHT...CIGS MAY DROP BACK TO IFR. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE FOR PRECIP ENDING BY 07Z...MEDIUM CONFIDENCE FOR
SHOWERS LATER THIS MORNING.
* HIGH CONFIDENCE REGARDING WINDS/SPEEDS/GUSTS THROUGH MID MORNING
THEN LOW CONFIDENCE FOR THE REST OF THE PERIOD.
* HIGH CONFIDENCE FOR IFR CIGS THROUGH MID MORNING...LOW
CONFIDENCE REGARDING CIG TRENDS THIS AFTERNOON INTO THIS
EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...CHANCE OF RAIN/SNOW SHOWERS. MVFR POSSIBLE.
SATURDAY...VFR.
SUNDAY THROUGH TUESDAY...PERIODIC CHANCES OF RAIN. OCCASIONAL MVFR
CONDITIONS POSSIBLE.
RATZER
&&
.MARINE...
300PM...A STRONG PRESSURE GRADIENT REMAINS IN PLACE OVER LAKE
MICHIGAN...BETWEEN STRONG HIGH PRESSURE OVER SOUTHEASTERN CANADA
AND A TROUGH OF LOW PRESSURE AND AN ASSOCIATED QUASI-STATIONARY
WARM FRONT EXTENDING EAST THROUGH CENTRAL ILLINOIS AND
INDIANA. NORTHEAST TO EAST GALES WILL PERSIST OVER ALL OF THE OPEN
WATERS THROUGH THE DAY TOMORROW. THE INITIAL LOW WILL LIFT
NORTHEAST TO NORTHERN INDIANA TOMORROW AS A SECONDARY LOW DEVELOPS
OVER IOWA. AN OCCLUDED FRONT CONNECTING THE TWO LOWS WILL LIFT
NORTHWARD UP THE LENGTH OF LAKE MICHIGAN TOMORROW EVENING AND INTO
FRIDAY...FINALLY REACHING THE NORTHERN END OF THE LAKE BY FRIDAY
AFTERNOON. WINDS WILL SUBSIDE BELOW GALE FORCE AS THE OCCLUDED
FRONT LIFTS NORTHWARD UP THE LAKE WITH WIND DIRECTION SHIFTING TO
NORTHWESTERLY AND THEN WESTERLY. THE MAIN LOW WILL THEN LIFT
NORTHEASTWARD INTO SOUTHEASTERN CANADA FRIDAY NIGHT AS HIGH
PRESSURE BUILDS ACROSS THE CENTRAL PLAINS. THE HIGH WILL SPREAD
EAST ACROSS LAKE MICHIGAN SATURDAY LEADING TO A BRIEF PERIOD OF
RELATIVELY LIGHT WINDS. AS THE HIGH PUSHES EAST OF THE LAKE BY
SUNDAY...NEW LOW PRESSURE WILL DEVELOP OVER THE CENTRAL
PLAINS...BRINGING INCREASING SOUTHEASTERLY TO SOUTHERLY WINDS TO
THE LAKE.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10
AM THURSDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741...10 AM THURSDAY TO 11 PM
FRIDAY.
GALE WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878 UNTIL 9 PM THURSDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ563 UNTIL 10 AM FRIDAY.
SMALL CRAFT ADVISORY...LMZ742 UNTIL 11 PM FRIDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 5 AM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1204 AM CDT THU APR 11 2013
.DISCUSSION...
ISSUED 930 PM CDT WED APR 10 2013
MCS CLUSTER CONTINUES TO PUSH ACROSS ILLINOIS SOUTHWARD TO NEAR
MEMPHIS...WITH THE CORE OF THE LINE ABOUT HALFWAY ACROSS THE ILX
FORECAST AREA. SURFACE OBS SHOWING A COUPLE LOWS...ONE JUST WEST
OF EFFINGHAM WHICH MAY BE MORE OF A MESO-LOW...AND THE PRIMARY LOW
JUST WEST OF ST LOUIS. ASSOCIATED SURFACE BOUNDARY WAS ROUGHLY
ALONG I-70 AT 9 PM...WHICH THE MODELS HAVE BEEN STRUGGLING WITH
ITS PLACEMENT UNTIL RECENTLY. HOWEVER...THE LATEST RAP MODEL HAS A
BETTER HANDLE ON IT...AND IS SHOWING A NORTHWARD BULGE BACK TOWARD
CHAMPAIGN AND DANVILLE BY AROUND MIDNIGHT AS THE MAIN LOW MOVES
INTO CENTRAL ILLINOIS. CONTINUING SEVERE THREAT ACROSS AREAS
MAINLY EAST OF I-55 FOR THE NEXT 3 TO 4 HOURS OR SO...THEN RAIN
WILL BE TAPERING FROM THE WEST AFTER MIDNIGHT. TEMPERATURES WILL
STILL BE A CHALLENGE WITH THE SIGNIFICANT TEMPERATURE SHIFTS ALONG
OUR CURRENT BOUNDARY AND THE INCOMING COLD FRONT...BUT THE
SOUTHEAST CWA IS MOST LIKELY TO REMAIN IN THE WARM SECTOR MOST OF
THE NIGHT.
GEELHART
&&
.AVIATION...
ISSUED 1200 PM CDT WED APR 10 2013
MAIN FORECAST CONCERN NOW WILL BE DURATION OF MVFR AND LOCAL IFR
CONDITIONS AS SLOW MOVING UPPER LOW TO OUR WEST TRACKS INTO THE
NORTHERN PLAINS. LARGE AREA OF MVFR CIGS NOTED ON THE SATELLITE
AND SURFACE OBSERVATIONS SO WILL CONTINUE FROM PREVIOUS TRENDS IN
HOLDING MOST AREAS DOWN TO MVFR WITH OCCASIONAL CIGS DROPPING TO
IFR OVERNIGHT AND DURING THE MORNING HOURS OF THURSDAY. WE SHOULD
SEE A GRADUAL INCREASE IN CIGS TO BETWEEN 1200 TO 2000 FEET DURING
THE AFTERNOON BUT DON`T SEE MUCH HOPE FOR ANY WIDESPREAD DECREASE
IN CLOUD COVER AS OUR FLOW WILL REMAIN CYCLONIC INTO THE EVENING
HOURS. WINDS WILL START OUT FROM AN EASTERLY DIRECTION BUT AS THE
SFC LOW PUSHES OFF TO OUR NORTH...EXPECT WINDS TO TURN MORE INTO
A SOUTHWEST TO WEST DIRECTION BY TOMORROW AFTERNOON. WIND SPEEDS
WILL RANGE FROM 10 TO 15 KTS WITH A FEW GUSTS AROUND 20 KTS EARLY
THIS MORNING.
SMITH
&&
.PREV DISCUSSION...
ISSUED 316 PM CDT WED APR 10 2013
ACTIVE WEATHER ONGOING WITH STRONG STORMS IN EXTREME EASTERN IL
AND THUNDERSTORMS IN WEST CENTRAL IL. THE BIGGEST QUESTION FOR
THIS EVENING AND TONIGHT WILL BE THE MOVEMENT OF LOW PRESSURE WEST
OF STL AND THE ASSOCIATED BOUNDARY THAT MOVED THROUGH MUCH OF
CENTRAL IL AND PARTS OF EAST CENTRAL IL THIS MORNING.
TEMPERATURES WILL BE ALL OVER THE PLACE THE NEXT SEVEN DAYS AS
COLDER AIR MOVES IN THE NEXT FEW DAYS...FOLLOWED BY A WARM UP
LATER IN THE WEEK AND THEN A POTENTIAL COOL DOWN AGAIN BY MIDWEEK.
ANOTHER UPPER LEVEL SYSTEM AND ASSOCIATED LOW AND COLD
FRONT...SIMILAR TO THE ONE WE ARE EXPERIENCING TONIGHT-FRIDAY...
IS EXPECTED FROM ABOUT TUESDAY THROUGH MIDWEEK.
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
THERE IS QUITE A BIT OF UNCERTAINTY AS TO THE TRACK OF THE
AFOREMENTIONED SURFACE LOW TONIGHT...WHICH WILL MAKE A HUGE
DIFFERENCE IN TEMPERATURES AND POTENTIAL FOR STRONG/SVR STORMS. AT
THIS POINT IT LOOKS LIKE THE NAM AND LOCAL WRF HAVE THE PREFERRED
SOLUTION WITH THE FRONT CREEPING A LITTLE BIT TO THE NORTH AND THE
LOW TRACKING REAL CLOSE TO SPI AFTER MIDNIGHT AND JUST NORTH OF
CMI-DNV BY DAYBREAK. THIS WOULD KEEP THE BIGGEST THREAT FOR
STRONG/SVR STORMS ROUGHLY ALONG AND EAST OF I-55.
THURSDAY MORNING THE COLD FRONT IS EXPECTED TO BE NEAR THE INDIANA
BORDER...SO WILL KEEP THE MENTION OF T-STORMS GOING IN THE MORNING
IN EASTERN IL...WITH A CHANCE FOR SHOWERS IN WEST CENTRAL IL AND
EAST OF A PIA-DEC-EFFINGHAM LINE THROUGH EARLY EVENING IN THE LOW
LEVEL CYCLONIC FLOW AND SHORTWAVE LIFTING THROUGH THE UPPER
MIDWEST.
CYCLONIC FLOW IS EXPECTED TO REMAIN OVER MUCH OF THE AREA UNTIL
EARLY SATURDAY KEEPING CLOUDS AND COOL TEMPERATURES OVER CENTRAL
AND EASTERN IL. COULD SEE A FEW LIGHT SHOWERS NORTH OF A GBG-PIA-
BMI LINE FRIDAY...OTHERWISE THE REST OF THE FORECAST AREA WILL BE DRY.
LONG TERM...SATURDAY THROUGH WEDNESDAY
HIGH PRESSURE ON SATURDAY WILL GIVE US A BRIEF BREAK IN THE
RAINFALL. HOWEVER...INCREASING WARM ADVECTION IN THE LOW AND MID
LEVELS AND A ZONAL UPPER LEVEL FLOW WILL BRING A RETURN TO SHOWERS
SATURDAY NIGHT...WITH A FEW THUNDERSTORMS POSSIBLE TOWARD SUNDAY
MORNING.
BY EARLY NEXT WEEK OUR UPPER LEVEL PATTERN WILL BACK TO A
SOUTHWEST FLOW AS ANOTHER UPPER LEVEL LOW IS EXPECTED TO DIG INTO
THE SOUTHWESTERN STATES. THE GFS AND EUROPEAN ARE ACTUALLY FAIRLY
SIMILAR IN DEPICTING THIS SCENARIO...ALTHOUGH THE EURO IS A BIT
MORE AMPLIFIED.
THE BIG QUESTION FOR MONDAY THROUGH WEDNESDAY IS WHERE WILL A
NEARLY STATIONARY FRONT SET UP. BOTH THE GFS AND EUROPEAN INDICATE
THAT THE FRONT WILL SETTLE INTO CENTRAL IL MONDAY MORNING AND
REMAIN OVER THE AREA UNTIL AT LEAST TUESDAY. THE GFS IS QUICKER
BRINGING OUT AN AREA OF LOW PRESSURE LATER TUESDAY...WHILE THE
EURO HOLDS OFF UNTIL WEDNESDAY. THE BOTTOM LINE FOR NOW IS THAT
DUE TO THE FRONT IN THE VICINITY WILL NEED TO KEEP AN EXTENDED
PERIOD OF CHANCE POPS IN THE FORECAST FOR MONDAY THROUGH WEDNESDAY.
MILLER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1209 AM CDT THU APR 11 2013
.UPDATE...
ISSUED AT 959 PM CDT WED APR 10 2013
HAVE UPDATED FORECAST TO REDUCE WINTER IMPACTS OF THE SYSTEM.
EXTRAPOLATION OF CURRENT PRECIP SHIELD SUGGESTS SRN BACK EDGE WILL
LIFT INTO MN 09-12Z...WHICH HAS BEEN SUPPORTED BY RECENT HRRR RUNS
WHICH SEEM TO BE HANDLING REALITY WELL. TEMPS ARE STILL AS WARM AS
36F AS FAR NORTH AS FORT DODGE...ALGONA...FOREST CITY AND IOWA
FALLS AND DUAL POL CC PRODUCTS ARE INDICATING PLENTY OF MIXED
PHASE PRECIP SUGGESTING IT WILL BE DIFFICULT TO GET MUCH SNOW
ACCUMS GOING ANYTIME SOON. ROAD SURFACE TEMPS TO THE MN BORDER ARE STILL
JUST ABOVE FREEZING AS WELL. MODELS ARE IN GOOD AGREEMENT
INCREASING VERTICAL MOTION FAIRLY SOON...SO CONFIDENCE IN LOWER
AMOUNTS IS NOT EXTREMELY HIGH...BUT FELT A DOWNWARD TREND WAS
STILL JUSTIFIED. COULD NOT SEE SNOW RATES MATERIALIZE IN TIME TO
REACH PREVIOUSLY ANTICIPATED AMOUNTS.
&&
.SHORT TERM.../TONIGHT /
ISSUED AT 421 PM CDT WED APR 10 2013
SURFACE LOW WILL CONTINUE TO TRACK SLOWLY EAST NORTHEAST FROM
CENTRAL MISSOURI INTO NORTHERN ILLINOIS BY 12Z THURSDAY. MODELS
REMAIN IN GOOD AGREEMENT WITH THE OVERALL SYNOPTIC PATTERN...BUT
NAM DRIES OUT THE UPPER LEVELS PAST 06Z THURSDAY IN NORTHERN IOWA
RESULTING IN LESSER SNOW AMOUNTS. LEANED TOWARD A SREF/GFS BLEND.
LARGE SWATH OF THETA-E ADVECTION WILL CONTINUE TO BRING WIDESPREAD
LIGHT TO MODERATE RAIN THIS EVENING OVER CENTRAL AND SOUTHERN
PORTIONS OF THE STATE. DRY SLOT BEGINS TO PUNCH INTO THE SOUTH
CENTRAL PORTION OF THE FORECAST AREA LATE THIS EVENING AND HAVE
DECREASED POPS IN THIS LOCATION. OTHERWISE...HIGHEST POPS NORTH OF
I-80 AS THE BEST FORCING AND THETA-E ADVECTION WILL PERSIST THROUGH
TOMORROW MORNING. NAM BUFR SOUNDINGS AT MCW TO ALO DEPICT THEY LOSE
ICE INTRODUCTION PAST 06Z THURSDAY...WHILE THE GFS KEEPS THE DEEPER
MOISTURE GOING OVERNIGHT. LEANED TOWARD THE GFS SOLUTION AS GOOD
THETA-E ADVECTION AND MOISTURE TRANSPORT PERSISTS ALONG THE 290K TO
305K ISENTROPIC SURFACE ACROSS FAR NORTHERN IOWA. TEMPERATURES LOOK
TO REMAIN NEAR FREEZING ACROSS THE NORTHEAST AND MAY SEE SOME FZRA
THIS EVENING BEFORE THE SWITCH OCCURS PAST MIDNIGHT. FURTHER
WEST...DENISON TO CARROLL TO FORT DODGE WILL SEE PRECIP SWITCHING
BACK AND FORTH FROM FZRA AND SNOW...POSSIBLY EVEN SOME SLEET AT
TIMES. AS A RESULT...LEANED TOWARD A WINTER WEATHER ADVISORY
FURTHER SOUTH WITH THE WINTRY MIX TONIGHT INTO THURSDAY MORNING.
NO MAJOR CHANGES WITH THE ONGOING SNOW FORECAST FOR THE FAR
NORTHWEST PORTIONS OF THE FORECAST AREA.
.LONG TERM.../THURSDAY THROUGH WEDNESDAY/
ISSUED AT 421 PM CDT WED APR 10 2013
THE MID LEVEL DRY SLOT WILL HAVE LIFTED OVER MUCH OF CENTRAL IOWA
BY THURSDAY MORNING AND THIS WILL BRING RESULT IN A LOSS OF ICE
INTRODUCTION. POSSIBLE THIS WILL LEAD TO FREEZING DRIZZLE OVER THE
FAR NORTH YET THROUGH THE MORNING WHERE SFC TEMPERATURES REMAIN AT
OR BELOW FREEZING. GIVEN THE TIME OF YEAR...ENOUGH RADIATION
SHOULD MAKE IT THROUGH THE CLOUD TO HEAT TEMPERATURES ENOUGH TO
RISE ABOVE FREEZING OVER THE NORTH AND ELIMINATE THE FREEZING RAIN
POTENTIAL. COOLING THROUGH THE COLUMN WILL ERODE THE REMAINING
WARM LAYER OVER HEADLINE REGION WITH THE POTENTIAL CHANGING TO
RAIN OR SNOW AS THE NEXT SHORT WAVE WRAPS AROUND FROM THE WEST AND
BRINGING A RETURN TO ICE INTRODUCTION. THE PRECIPITATION WILL
GRADUALLY END AS SNOW OVER THE NORTHEAST THURSDAY NIGHT AND EARLY
FRIDAY WITH ONLY MINOR ACCUMULATIONS EXPECTED. KEPT HIGH
TEMPERATURES ON THURSDAY BELOW GUIDANCE WHICH ARE PRODUCING TOO
STEEP OF LOW LEVEL LAPSE RATES WITH THE GIVEN CLOUD COVER. A BLEND
OF RAW TEMPERATURES IS A BETTER FIT
COLD CONDITIONS WILL CONTINUE ON FRIDAY WITH BREEZY NORTHWEST
WINDS AND THE 850 MB THERMAL TROUGH EXTENDING INTO THE STATE. THE
MID LEVEL FLOW BECOMES MORE ZONAL ON SATURDAY AND AFTER A COOL
START...TEMPERATURES WILL WARM TO AROUND 10 DEGREES WARMER THAN
FRIDAY THOUGH STILL WELL BELOW SEASONAL AVERAGES. PRECIPITATION
CHANCES RETURN SATURDAY NIGHT WITH STRONG THETA-E ADVECTION
LIFTING INTO THE REGION. LOW PRESSURE MOVING THROUGH ON SUNDAY
WILL KEEP CHANCES GOING WITH THE POTENTIAL FOR SHOWERS AND
ISOLATED THUNDERSTORMS. ANOTHER LONG WAVE TROUGH WILL DEVELOP OVER
THE WESTERN CONUS THROUGH EARLY TO MID NEXT WEEK AND WILL KEEP THE
STATE IN AN ACTIVE PATTERN. THE 850 MB THERMAL GRADIENT WILL
REMAIN NEARBY THROUGH THE PERIOD THEN GRADUALLY SINK INTO THE AREA
TUESDAY INTO WEDNESDAY. MUCH OF THE PRECIPITATION WILL FALL IN
THE FORM OF RAIN THOUGH THE ARRIVAL OF THE COLDER AIR COULD BRING A
MIX OF SNOW ONCE AGAIN OVER THE NORTH.
&&
.AVIATION...11/06Z
ISSUED AT 1208 AM CDT THU APR 11 2013
WIDESPREAD IFR CONDITIONS EXIST ACROSS THE FORECAST AREA LATE THIS
EVENING AND LITTLE CHANGE IN CATEGORY IS ANTICIPATED INTO THE
NIGHT. A FEW SPOTS MAY BRIEFLY BUMP UP TO MVFR BUT THAT WOULD NOT
LAST LONG. AREA OF SOMEWHAT HEAVIER PRECIPITATION WILL CONTINUE
LIFTING NORTHWARD...MAINLY AFFECTING WRN HALF OF IA WITH
PREDOMINATELY RAIN. MAY SEE A SMALL WINDOW OF LIGHT FREEZING
PRECIP AT MCW HOWEVER. MUCH OF THE HEAVIER PRECIP SHOULD EXIT IA
INTO MN BY 11-12Z LEAVING BEHIND DRIZZLE AND STRATUS...STILL IFR
OR POSSIBLE LOW END MVFR BY AFTERNOON. IFR/MVFR CIGS WILL REMAIN
IN PLACE INTO WED EVENING AS WELL...POSSIBLY WITH SOME LIGHT SNOW
BY THAT TIME.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR
CALHOUN-CERRO GORDO-CRAWFORD-HANCOCK-HUMBOLDT-POCAHONTAS-SAC-
WORTH.
WINTER STORM WARNING UNTIL 1 PM CDT THIS AFTERNOON FOR EMMET-
KOSSUTH-PALO ALTO-WINNEBAGO.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
UPDATE/AVIATION...SMALL
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
229 PM EDT FRI APR 12 2013
.UPDATE...
ISSUED AT 228 PM EDT FRI APR 12 2013
GRIDS WERE UPDATED BASED ON RECENT OBSERVATIONS. CU AND OR STRATOCU
SHOULD INCREASE...ESPECIALLY NORTH OF A LINE FROM EKQ TO LOZ TO K22
OVER THE NEXT COUPLE OF HOURS AS A SHORTWAVE MOVES THROUGH THE OH
VALLEY REGION. THE CU AND STRATOCU MAY HANG ON FOR A WHILE LONGER
THAN PREVIOUSLY FORECAST THIS EVENING AS WELL. SKY COVER GRIDS WERE
UPDATED ACCORDINGLY.
UPDATE ISSUED AT 1157 AM EDT FRI APR 12 2013
BEHIND THE DEPARTING LOW PRESSURE SYSTEM...AN UPPER LEVEL DISTURBANCE
WILL ROTATE THROUGH THE OH VALLEY TODAY AND THIS COMBINED WITH SOME
LOW LEVEL MOISTURE FROM RECENT PRECIPITATION SHOULD RESULT IN SOME
CU THIS AFTERNOON. THE CU SHOULD BE MOST WIDESPREAD ACROSS THE NORTH
AND NOT AS MUCH COVERAGE CLOSER TO THE VA BORDER.
TEMPS AND DEWPOINTS WERE FRESHENED UP BASED ON RECENT OBSERVATIONS
AND WINDS WERE INCREASED A BIT...ESPECIALLY ACROSS THE SOUTH. WITH
THE UPDATED ZFP...MORNING WORDING WAS CLEANED UP.
UPDATE ISSUED AT 655 AM EDT FRI APR 12 2013
COLD FRONT IS JUST ABOUT TO PUSH EAST OF PIKE COUNTY WITH ALL OF THE
AREA NOW SEEING TEMPERATURES FALL FAIRLY QUICKLY ALONG WITH
DEWPOINTS. SOME MID 40 TEMPERATURES ALREADY SHOWING UP ACROSS MUCH OF
CENTRAL KENTUCKY. SOME DRIZZLE HAS PERSISTED BEHIND THE DEPARTING
FRONT WITH JUST ENOUGH LOW LEVEL MOISTURE TRAPPED BELOW THE LOW LEVEL
INVERSION. THIS DRIZZLE SHOULD BE SHORT LIVED THIS MORNING AS
CEILINGS INCREASE BY MID MORNING. RUC NOW SHOWS CLOUDS HANGING ON FOR
MOST OF THE DAY...WHILE THE NAM CONTINUES TO SHOW LOW CLOUDS
DISSOLVING. GIVEN LATEST SATELLITE TRENDS...OUR WESTERN COUNTIES MAY
BE CLEARING OUT SHORTLY. GIVEN THE WIND FLOW IS NOT FAVORABLE FOR LOW
CLOUDS HANGING IN TODAY...HAVE OPTED TO GO WITH A BIT FASTER CLEARING
HAVING SKIES GO MOSTLY SUNNY BY THIS AFTERNOON. LOW CLOUDS CAN
SOMETIMES BE TRICKY AND NAM DOES SHOW MORE CLOUDS MOVING IN LATER THIS
AFTERNOON. HOWEVER...AS OF RIGHT NOW...NOT MUCH UPSTREAM...SO OPTING
TO GO A LITTLE MORE OPTIMISTIC.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 308 AM EDT FRI APR 12 2013
COLD FRONT HAS REACHED THE I-75 CORRIDOR IN THE LAST HOUR AND WILL
CONTINUE TO PUSH EAST ACROSS THE AREA EARLY THIS MORNING...CLEARING
FAR EASTERN KENTUCKY AROUND DAYBREAK. COOLER AND DRIER AIR WILL
FILTER INTO THE AREA TODAY. WITH COLD ADVECTION DURING THE MORNING
HOURS...A SMALL CLIMB FROM MORNING LOWS IS ANTICIPATED. CLOUDS WILL
LIKELY HOLD ON LONGER THAN THE NAM SUGGEST...AND CLOSER TO THE RUC
SOLUTION. THIS HAS CLOUDS EVENTUALLY BREAKING UP BY EARLY AFTERNOON.
THIS WILL ALSO IMPACT THE TEMPERATURE CLIMB TODAY. WE SHOULD BE ABLE
TO AT LEAST REACH THE MID/UPPER 50S...WITH AREAS IN THE SOUTHWEST
POSSIBLY EXCEEDING 60 WITH MORE CLEARING.
HIGH PRESSURE WILL BUILD ACROSS THE AREA TONIGHT INTO TOMORROW WITH
SKIES GOING MOSTLY CLEAR. SHELTERED VALLEYS MAY DECOUPLE TONIGHT
LEADING TO READINGS AT LEAST INTO THE MID 30S. THIS SHOULD ALLOW FOR
SOME LIMITED FROST POTENTIAL TONIGHT. A QUIET SATURDAY IS ON TAP WITH
PLENTY OF SUNSHINE BOOSTING TEMPERATURES INTO THE 60S.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 308 AM EDT FRI APR 12 2013
THE MODELS HAVE COME INTO BETTER AGREEMENT ALOFT THROUGH THE BREADTH
OF THE EXTENDED PORTION OF THE FORECAST. THEY ALL STILL TAKE THE
GREAT LAKES TROUGH EAST EARLY IN THE PERIOD ALLOWING FOR RISING
HEIGHTS OVER KENTUCKY THIS WEEKEND AND INTO THE FIRST PART OF NEXT
WEEK. THEY ALSO ALL HAVE VARIOUS REPRESENTATIONS OF A MINOR TROUGH
PASSING THROUGH THE SOUTHEAST PORTION OF THE NATION DURING THE LATTER
PART OF THE WEEKEND. THIS UNCONSOLIDATED WAVE MAY YET HAVE A
SENSIBLE IMPACT ON THE WEATHER OF EAST KENTUCKY INTO MONDAY MORNING
WITH THE NAM12 THE MOST BEARISH AND THE GFS/GEM RATHER BENIGN.
MEANWHILE...A MODERATELY STRONG CLOSED LOW WILL BE LIFTING NORTHEAST
THROUGH THE NORTHERN PLAINS WELL AWAY FROM OUR AREA. TO THE WEST OF
THIS...A DEEPENING NODE OF THE BROAD NORTHWESTERN TROUGH WILL DEVELOP
INTO A POTENT TROUGH IN ITS OWN RIGHT AND SLOWLY START TO COME EAST.
AS THIS FEATURE STRENGTHENS AND DROPS TOWARD THE FOUR CORNERS REGION
IT WILL HELP TO PUMP UP THE DOWNSTREAM RIDGE OVER THE SOUTHEAST
PORTION OF THE NATION INTO MIDWEEK. THE ECMWF AND GFS ARE IN REAL
GOOD AGREEMENT NOW WITH THE LATTER PORTION OF THE EXTENDED WHILE THE
GEM IS QUICKER AND FURTHER NORTH WITH ITS TROUGH. THIS TROUGH MOVES
INTO THE CENTRAL PLAINS ON THURSDAY WITH HEIGHT FALLS INBOUND FOR
KENTUCKY. GIVEN THE AGREEMENT OF THE PREFERRED MODELS WITH THIS WILL
FAVOR A BLENDED SOLUTION THROUGH THE EXTENDED.
SENSIBLE WEATHER WILL FEATURE A DRY AND COOL START TO THE WEEKEND
WITH PATCHY FROST POSSIBLE IN THE DEEPER VALLEYS OF EAST KENTUCKY
SUNDAY MORNING. HOWEVER...MODERATING HIGH PRESSURE MOVING OFF TO THE
EAST AND A RIDGE BUILDING ALOFT WILL ALLOW FOR A SOLID WARM UP TO
COMMENCE AND CONTINUE INTO MID WEEK. A WEAK SFC WAVE PASSING TO THE
SOUTH OF EAST KENTUCKY LATE SUNDAY NIGHT AND EARLY MONDAY MAY
TRIGGER SOME CONVECTION OVER SOUTHERN PARTS OF THE CWA. ONCE THIS
PASSES...EAST KENTUCKY WILL BE ON THE NORTHWEST FRINGE OF A LARGE
AREA OF HIGH PRESSURE ALLOWING FOR RETURN FLOW MOISTURE TO INVADE
FROM A RELATIVELY OPEN GULF OF MEXICO. THIS MOISTURE WILL SLOWLY
BUILD THROUGH THE WEEK IN THIS EARLY SUMMER-LIKE PATTERN AND RESULT
IN A DAILY CHANCE FOR MAINLY AFTERNOON AND EVENING SHOWERS OR
THUNDERSTORMS THROUGH WEDNESDAY. A BETTER CHANCE OF RAIN CAN BE
ANTICIPATED ON THURSDAY AS A DEEP AREA OF LOW PRESSURE LIFTS OUT OF
THE CENTRAL PLAINS AND MOVES TO THE NORTHERN GREAT LAKES. THIS WILL
DRAG A COLD FRONT INTO KENTUCKY HELPING TO FOCUS THE BUILT UP
MOISTURE. WITH THE BETTER CHANCES OF RAIN THURSDAY WILL LIKELY BREAK
THE TREND OF CLIMBING HIGHS FROM DAY TO DAY.
THE CR GRID LOAD CAME IN PRETTY DECENT...BUT DID NUDGE DOWN POPS ON
MONDAY GIVEN THE UNCERTAINTY AND ALSO FINE TUNED THEM LATER IN THE
EXTENDED MORE TOWARD THE 12Z ECMWF. ALSO MAKE SOME SIGNIFICANT
TERRAIN BASED ADJUSTMENTS FOR LOWS EACH NIGHT...ANTICIPATING DECENT
RIDGE TO VALLEY SPLITS THROUGHOUT THE EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 228 PM EDT FRI APR 12 2013
DESPITE AN UPPER LEVEL DISTURBANCE TO ROTATE THROUGH THE OH VALLEY
THROUGH THIS EVENING AND ANOTHER ON SATURDAY...CEILINGS SHOULD REMAIN
IN THE VFR RANGE AT ALL TIMES AS SFC HIGH PRESSURE BUILDS INTO THE
REGION AND DRIER AIR WORKS IN ESPECIALLY AT LOWER LEVELS. CU AND
STRATOCU SHOULD HANG ON A FEW HOURS INTO THE EVENING...LIKELY INTO
THE 0Z TO 6Z RANGE WITH CLEARING THEREAFTER BEFORE A FEW CU DEVELOP
AROUND 15Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
227 PM EDT THU APR 11 2013
.UPDATE...
ISSUED AT 215 PM EDT THU APR 11 2013
HOURLY SKY...TEMPS AND DEWPOINTS HAVE BEEN FRESHENED UP FOR THE NEXT
FEW HOURS THIS AFTERNOON. SOME THINNER CIRRUS IS CURRENTLY WORKING
ACROSS THE CWA AT THIS POINT...ESPECIALLY EAST OF INTERSTATE 75 AND
TEMPS IN MANY LOCATIONS ARE PROBABLY NEARING DAYTIME HIGHS AS CU HAS
BEGUN TO DEVELOP. THE LATEST RADAR IMAGERY AND TRENDS INDICATE THAT
CONVECTION HAS BEEN SLOW TO INTENSIFY OVER MIDDLE TN AND CENTRAL KY.
HOWEVER...GIVEN CURRENT DEGREE OF SUNSHINE OVER MUCH OF THE AREA...
SOME INTENSIFICATION SHOULD OCCUR AS CONVECTION WORKS INTO THE
REGION LATE THIS AFTERNOON AND EVENING. AT THE LEAST THERE WILL BE
GUSTY WINDS WITH AN ANTICIPATED LINE OF CONVECTION AND CHANCES FOR A
FEW SEVERE THUNDERSTORMS ALONG THE LINE AS IT WORKS INTO EASTERN KY.
THE REGION REMAINS IN A SLIGHT RISK OF SEVERE THUNDERSTORMS AND
TIMING INTO LOCATIONS WEST OF I75...AROUND OR SHORTLY AFTER 5 PM
STILL LOOKS ON TARGET.
UPDATE ISSUED AT 1140 AM EDT THU APR 11 2013
DEBRIS CLOUD COVER FROM CONVECTION THAT OCCURRED AND IS OCCURRING
CLOSER TO THE APPROACHING BOUNDARY CONTINUES TO MOVE ACROSS THE
REGION. THIS IS LIMITING HEATING FROM WHAT THE POTENTIAL WOULD BE FOR
THIS TIME IN APRIL WITH A STRONG SUN ANGLE. DEWPOINTS WILL GRADUALLY
INCREASE AS WELL AND THEY ARE IN THE 50S...BUT UPPER 50S TO LOWER 60S
DEWPOINTS ARE GENERALLY CLOSER TO THE APPROACHING SFC COLD FRONT AND
FROM ABOUT THE OH RIVER AND NORTH. ANOTHER CONSIDERATION IS THE
SHORTWAVE MOVING FROM THE SOUTHERN PLAINS INTO THE LOWER MS VALLEY
REGION TOWARD AREAS WHERE MOISTURE IS DEEPER. CONVECTION THERE MAY
BECOME RATHER WIDESPREAD AND LIMIT MOISTURE TRANSPORT INTO THE REGION
SOMEWHAT AS WELL. HOWEVER...THE SYSTEM IS STILL EXPECTED TO BE RATHER
DYNAMIC AND SFC LOWS TRACKING BY TO OUR NORTH AND WEST DURING DAYTIME
TO EVENING TIMEFRAME IS A PATTERN THAT OFTEN TIMES PRODUCES AT LEAST
SOME SEVERE WEATHER IN EASTERN KY.
THE REGION REMAINS IN A SLIGHT RISK AREA FOR SEVERE THUNDERSTORMS
LATER TODAY...WITH PROBABILITIES GENERALLY GREATER TO OUR
SOUTH...ESPECIALLY GULF COAST STATES. A COMBINATION OF EXTRAPOLATION
OF SAT IMAGERY AND MODEL FORECASTS GENERALLY POINTS TOWARD THE LEAST
CLOUD COVER OVER THE NEXT FEW HOURS GENERALLY ALONG AND SOUTH OF A
LINE FROM MCCREARY COUNTY TO LOZ TO JKL TO K22 SOUTH AND EAST TOWARD
THE VA BORDER. THIS REGION SHOULD GET THE WARMEST THIS
AFTERNOON...BUT DEEPER MIXING WILL ALSO TEND TO DROP TO OR HOLD
DEWPOINTS IN THE LOWER TO MID 50S...BUT TEMPS IN LOWER ELEVATIONS IN
THIS AREA SHOULD REACH INTO THE 80 TO 85 RANGE ON AVERAGE. THIS
HEATING SHOULD ALLOW CAPE TO REACH THE 500 TO 1000 J/KG RANGE LATE
THIS AFTERNOON OR EARLY THIS EVENING AND THE APPROACH OF THE FRONT
AND UPPER LEVEL TROUGH SHOULD LEAD TO DEVELOPMENT OR RE-
INTENSIFICATION OF CONVECTION ALONG OR JUST AHEAD OF THE COLD FRONT
FROM VERY LATE AFTERNOON THROUGH THIS EVENING OR ABOUT 5 PM AND
AFTER. ALL FACTORS CONSIDERED SEEMS TO POINT TOWARD ISOLATED TO
SCATTERED SHOWERS OR ORDINARY THUNDERSTORMS IN THE WESTERN AND
NORTHWESTERN LOCATIONS FROM MID TO LATE AFTERNOON...WITH A LINE OF
GUSTY SHOWERS WITH SOME THUNDERSTORMS...WITH THE POTENTIAL FOR SOME
DAMAGING WIND GUSTS. SHEAR IS SUFFICIENT THAT IF THE BOUNDARY LAYER
CAN BECOME SUFFICIENTLY MOIST THAT A STRAY TORNADO ALONG THE LINE OF
CONVECTION CANNOT BE COMPLETELY RULED OUT. IF A STORM OR TWO WERE TO
ROTATE THAN SOME LARGE HAIL WOULD BE POSSIBLE...BUT THIS SHOULD BE
VERY ISOLATED...WITH ANY HAIL THAT OCCURS EXPECTED TO BE ALONG THE
LINES OF SUB SEVERE LEVELS.
THE GRIDS AND ZFP WERE UPDATED TO REFINE TIMING BASED ON CURRENT
OBSERVED TRENDS AND LATEST MODEL GUIDANCE AS WELL AS TO ADJUST SKY
AND TEMPS AS NOTED ABOVE.
UPDATE ISSUED AT 650 AM EDT THU APR 11 2013
STARTING TO SEE A FEW MID LEVEL RETURNS CREEPING INTO THE SOUTHWEST
PORTION OF THE AREA. HOWEVER...BASES REMAIN MUCH TOO HIGH TO ALLOW
FOR AND PRECIPITATION REACHING THE GROUND. PRECIPITATION IS
ATTEMPTING TO PUSH INTO CENTRAL KENTUCKY THIS MORNING...BUT IS MAKING
VERY SLOW PROGRESS. THE LATEST RAP AND NAM SUGGEST A LATER ONSET OF
PRECIPITATION TODAY...POSSIBLY HOLDING OFF UNTIL 7 OR 8 PM THIS
EVENING FOR MUCH OF THE AREA. THE I-75 CORRIDOR MAY SEE THINGS START
A BIT EARLY TOWARDS 5 OR 6 PM. THESE TRENDS MAY NEED TO BE WATCHED.
WITH INSTABILITY ALREADY IN QUESTION...A LATER ONSET TOWARDS MID TO
LATE EVENING MAY LIMIT THE SEVERE THREAT AS INSTABILITY MAY SIMPLY
NOT BE THERE. IN FACT...THE LATEST HRRR SHOWS PRETTY ROBUST
CONVECTION TO THE SOUTH OF THE AREA BY MID AFTERNOON...SUGGESTING
THAT THE EARLIER ASSUMPTION ABOUT STORMS TO THE SOUTH ROBBING US OF
OUR INSTABILITY MAY BE TRUE. THESE TRENDS WILL HAVE TO BE MONITORED
THIS MORNING. CLEARLY...THIS IS NOT A CLEAR CUT SCENARIO FOR SEVERE
WEATHER. HAVE MADE SOME MINOR TWEAKS TO THE LATEST
TEMPERATURE/DEWPOINT CURVES...AND ADJUSTED SLIGHTLY THE ONSET OF
PRECIPITATION. NO NEED TO UPDATE THE FORECAST THROUGH.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 316 AM EDT THU APR 11 2013
STRONG COLD FRONT CURRENTLY EXTENDS FROM NORTHERN INDIANA...SOUTHWARD
INTO FAR WESTERN KENTUCKY. A LINE OF SHOWERS AND STORMS CONTINUES TO
PUSH EAST ALONG THIS FRONTAL BOUNDARY. MODELS ARE ALL IN PRETTY GOOD
AGREEMENT WITH THE POSITION AND TIMING OF THIS FRONT AS IT CROSSES
EASTERN KENTUCKY LATER TODAY. UNIDIRECTIONAL WIND SHEAR IS SUFFICIENT
TO WARRANT A WIND THREAT WITH ANY THUNDERSTORMS THAT DEVELOP. LCL`S
MAY GET LOW ENOUGH IN THE CUMBERLAND PLATEAU TO SUPPORT AN ISOLATED
TORNADO...BUT THOSE LCL`S GO WAY UP AS YOU GO NORTH AND EAST. ONSET
FOR PRECPITATION SHOULD BE SOMETIME AFTER 2 PM FOR MOST AREAS TODAY.
THE BIG QUESTION SURROUNDING SEVERE POTENTIAL IS WHETHER ENOUGH
INSTABILITY WILL EXISTS TO SUPPORT THUNDERSTORMS WITH STRONG
DOWNDRAFTS. USING SFC BASED PARCEL OF 80/58 PRODUCES AROUND 900J/KG
OF SBCAPE. ALTHOUGH THIS IS MARGINAL...IT SHOULD BE SUFFICIENT TO
SUPPORT THUNDERSTORMS AND THUS WE COULD SEE SOME STRAY DAMAGING WIND
GUSTS. THUS...WILL MAINTAIN THE SEVERE THREAT WORDING IN THE HWO. THE
POTENTIAL DOES EXIST THAT CONVECTION DEVELOPING TO OUR SOUTH LATER
THIS AFTERNOON COULD ROB EASTERN KENTUCKY AND LIMIT THE SEVERE THREAT
OVER THE AREA. HOWEVER...THIS WOULD BE TOUGH TO BASE A FORECAST
ON...SO GOING TO MAINTAIN THE SEVERE THREAT.
SEVERE THREAT WILL COME TO AN END BY MIDNIGHT AS COLD FRONT PUSHES
EAST OUT OF THE AREA. RAIN WILL EVENTUALLY END FROM WEST TO EAST
OVERNIGHT. SYSTEM SHOULD BE PROGRESSIVE ENOUGH TO LIMIT ANY
SIGNIFICANT FLOODING ISSUE...ESPECIALLY WITH THE LACK OF RECENT
RAINFALL. SIGNIFICANTLY COOLER WEATHER WILL RETURN TO THE AREA LATE
TONIGHT. THE MORE SIGNIFICANT COLD AIR STAYS TO OUR NORTHWEST ON
FRIDAY. ALTHOUGH TEMPERATURES WILL BE COOLER...AFTERNOON READINGS MAY
STILL CLIMB INTO THE LOWER 60S UNDER SUNSHINE. SOME LOW CLOUDS MAY
START THE DAY...BUT GUSTY SOUTHWEST WINDS SHOULD ERODE THESE CLOUDS
FAIRLY QUICKLY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 AM EDT THU APR 11 2013
THE MODELS ARE IN REASONABLY GOOD AGREEMENT THROUGH THE EXTENDED AND
ONLY START TO SIGNIFICANTLY DIVERGE TOWARD THE END. THE ALL AGREE
THAT A DEEP CLOSED LOW OVER THE GREAT LAKES WILL ROTATE OUT OF THE
AREA TO THE NORTHEAST. THIS PROCESS IS FACILITATED BY A DECENT
SHORTWAVE THAT WILL TRACK THROUGH THE OHIO VALLEY ON SATURDAY...WITH
THE ECMWF REPRESENTING A GOOD COMPROMISE BETWEEN THE SLOWER GEM AND
FASTER GFS. HEIGHTS WILL RISE IN THE WAKE OF THE UPPER LOW/S
DEPARTURE WITH A HINT OF RIDGING TAKING PLACE TO CLOSE OUT THE
WEEKEND. TO THE SOUTH OF THE AREA...A LOOSE CLUSTER OF ENERGY WILL
DRIFT PAST LATER THAT NIGHT AND MAY BE ENOUGH TO HAVE AN EFFECT ON
THE SENSIBLE WEATHER OF SOUTHEAST KENTUCKY. OTHERWISE...RENEWED
RIDGING WILL TAKE SHAPE OVER SOUTHEAST PORTION OF THE NATION
RESULTING IN RISING HEIGHTS THROUGH TUESDAY. THE MODELS ARE HINTING
THAT THIS PATTERN MAY BREAK DOWN LATER IN THE WEEK AS TROUGHING OUT
WEST STARTS TO MOVE EAST INTO THE PLAINS ON WEDNESDAY...FASTEST IN
THE GFS WHEN COMPARED TO THE 12Z ECMWF. IN ADDITION...A FEW WEAKER
PATCHES OF ENERGY WILL LIKELY START TO MAKE THEIR WAY THROUGH THE
REGION OUT AHEAD OF THE LARGER...INBOUND...SYSTEM.
SENSIBLE WEATHER WILL FEATURE A BRIEF COOL DOWN FOR THE START OF THE
WEEKEND AS HIGH PRESSURE SETTLES INTO THE AREA FOLLOWING THE LARGER
LOW PRESSURE SYSTEM EXITING TO THE NORTHEAST. THIS HIGH WILL QUICKLY
MODERATE...THOUGH...SO THAT EACH AFTERNOON WE CAN EXPECT
TEMPERATURES A FEW DEGREES HIGHER THAN THE PREVIOUS ONE THROUGH
TUESDAY. MORE IN THE WAY OF CLOUDS AND A BETTER POTENTIAL FOR
SHOWERS AND THUNDERSTORMS...LIKE A SUMMER TIME DIURNAL CONVECTIVE
PATTERN...MAY KEEP TEMPS A BIT LOWER ON WEDNESDAY THAN TUESDAY. THIS
POTENTIAL AND THE UNCERTAINTY OF THE TIMING FOR THE NEXT SYSTEM
MIDWEEK CALLS FOR LOW TO MID RANGE POP CHANCES FOR WEDNESDAY. THE
REST OF THE EXTENDED WILL LIKELY BE DRY...THOUGH CAN/T RULE OUT A
STRAY SHOWER EARLY MONDAY AS A WEAK SFC WAVE PASSES BY TO THE
SOUTH.
THE CR GRID LOAD CAME IN PRETTY DECENT...BUT DID NUDGE DOWN POPS
TUESDAY AND WEDNESDAY MORE TOWARDS THE 12Z ECMWF. ALSO MAKE SOME
SIGNIFICANT TERRAIN BASED ADJUSTMENTS FOR LOWS EACH NIGHT...
ANTICIPATING DECENT RIDGE TO VALLEY SPLITS THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 225 PM EDT THU APR 11 2013
VFR CONDITIONS REMAIN IN PLACE AHEAD OF THE BOUNDARY IN EASTERN KY.
CU AROUND 5 TO 6KFT AGL HAS BEGUN TO DEVELOP. UNTIL CONVECTION
ARRIVES...VFR VIS AND CEILINGS ARE ANTICIPATED. AS A COLD FRONT
APPROACHES...WINDS WILL BECOME MORE SOUTH TO SOUTHWEST OVER THE NEXT
FEW HOURS...AND MAY BE ACCOMPANIED BY GUSTS UP TO 20 KT OR
SO...ESPECIALLY AT LOZ AND SME. SHRA AND SOME TSRA...SHOULD PUSH INTO
THE LAKE CUMBERLAND REGION AND THEN EASTERN KENTUCKY AS EARLY AS 21Z
AT LOCATIONS SUCH AS SME AND LOZ. CIGS SHOULD REMAIN ELEVATED
INITIALLY...BUT AS THE ATMOSPHERE MOISTENS OVER THE FIRST 3 TO 5
HOURS AFTER CONVECTION ARRIVES CIGS SHOULD DETERIORATE TO MVFR..THEN
IFR AND FINALLY APPROACH AIRPORT MINS AT SOME POINT DURING THE 0Z TO
13Z WINDOW. A FEW SEVERE WIND GUSTS ARE POSSIBLE WITH ANY THUNDERSTORMS
21Z THROUGH 4Z. BEHIND THE FRONT AND INITIAL LINE OF SHRA AND TSRA...
RAIN SHOULD PERSIST FOR A FEW HOURS...BUT EXIT THE AREA BETWEEN 6Z
AND 12Z. WE COULD EXPERIENCE STRATUS BUILDDOWN OR A BIT OF CLEARING
THAT MIGHT LEAD TO SOME FOG. THERE IS UNCERTAINTY AS TO HOW LOW VIS
MIGHT DROP WITH THIS AND DEPENDS ON DEGREE OF SATURATION. THE STRATUS
OR FOG SHOULD MIX INTO MVFR CU BETWEEN 12Z AND 16Z...AND THEN SOME CU IN
THE VFR RANGE AROUND 4 TO 5KFT AGL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1140 AM EDT THU APR 11 2013
.UPDATE...
ISSUED AT 1140 AM EDT THU APR 11 2013
DEBRIS CLOUD COVER FROM CONVECTION THAT OCCURRED AND IS OCCURRING
CLOSER TO THE APPROACHING BOUNDARY CONTINUES TO MOVE ACROSS THE
REGION. THIS IS LIMITING HEATING FROM WHAT THE POTENTIAL WOULD BE FOR
THIS TIME IN APRIL WITH A STRONG SUN ANGLE. DEWPOINTS WILL GRADUALLY
INCREASE AS WELL AND THEY ARE IN THE 50S...BUT UPPER 50S TO LOWER 60S
DEWPOINTS ARE GENERALLY CLOSER TO THE APPROACHING SFC COLD FRONT AND
FROM ABOUT THE OH RIVER AND NORTH. ANOTHER CONSIDERATION IS THE
SHORTWAVE MOVING FROM THE SOUTHERN PLAINS INTO THE LOWER MS VALLEY
REGION TOWARD AREAS WHERE MOISTURE IS DEEPER. CONVECTION THERE MAY
BECOME RATHER WIDESPREAD AND LIMIT MOISTURE TRANSPORT INTO THE REGION
SOMEWHAT AS WELL. HOWEVER...THE SYSTEM IS STILL EXPECTED TO BE RATHER
DYNAMIC AND SFC LOWS TRACKING BY TO OUR NORTH AND WEST DURING DAYTIME
TO EVENING TIMEFRAME IS A PATTERN THAT OFTEN TIMES PRODUCES AT LEAST
SOME SEVERE WEATHER IN EASTERN KY.
THE REGION REMAINS IN A SLIGHT RISK AREA FOR SEVERE THUNDERSTORMS
LATER TODAY...WITH PROBABILITIES GENERALLY GREATER TO OUR
SOUTH...ESPECIALLY GULF COAST STATES. A COMBINATION OF EXTRAPOLATION
OF SAT IMAGERY AND MODEL FORECASTS GENERALLY POINTS TOWARD THE LEAST
CLOUD COVER OVER THE NEXT FEW HOURS GENERALLY ALONG AND SOUTH OF A
LINE FROM MCCREARY COUNTY TO LOZ TO JKL TO K22 SOUTH AND EAST TOWARD
THE VA BORDER. THIS REGION SHOULD GET THE WARMEST THIS
AFTERNOON...BUT DEEPER MIXING WILL ALSO TEND TO DROP TO OR HOLD
DEWPOINTS IN THE LOWER TO MID 50S...BUT TEMPS IN LOWER ELEVATIONS IN
THIS AREA SHOULD REACH INTO THE 80 TO 85 RANGE ON AVERAGE. THIS
HEATING SHOULD ALLOW CAPE TO REACH THE 500 TO 1000 J/KG RANGE LATE
THIS AFTERNOON OR EARLY THIS EVENING AND THE APPROACH OF THE FRONT
AND UPPER LEVEL TROUGH SHOULD LEAD TO DEVELOPMENT OR RE-
INTENSIFICATION OF CONVECTION ALONG OR JUST AHEAD OF THE COLD FRONT
FROM VERY LATE AFTERNOON THROUGH THIS EVENING OR ABOUT 5 PM AND
AFTER. ALL FACTORS CONSIDERED SEEMS TO POINT TOWARD ISOLATED TO
SCATTERED SHOWERS OR ORDINARY THUNDERSTORMS IN THE WESTERN AND
NORTHWESTERN LOCATIONS FROM MID TO LATE AFTERNOON...WITH A LINE OF
GUSTY SHOWERS WITH SOME THUNDERSTORMS...WITH THE POTENTIAL FOR SOME
DAMAGING WIND GUSTS. SHEAR IS SUFFICIENT THAT IF THE BOUNDARY LAYER
CAN BECOME SUFFICIENTLY MOIST THAT A STRAY TORNADO ALONG THE LINE OF
CONVECTION CANNOT BE COMPLETELY RULED OUT. IF A STORM OR TWO WERE TO
ROTATE THAN SOME LARGE HAIL WOULD BE POSSIBLE...BUT THIS SHOULD BE
VERY ISOLATED...WITH ANY HAIL THAT OCCURS EXPECTED TO BE ALONG THE
LINES OF SUB SEVERE LEVELS.
THE GRIDS AND ZFP WERE UPDATED TO REFINE TIMING BASED ON CURRENT
OBSERVED TRENDS AND LATEST MODEL GUIDANCE AS WELL AS TO ADJUST SKY
AND TEMPS AS NOTED ABOVE.
UPDATE ISSUED AT 650 AM EDT THU APR 11 2013
STARTING TO SEE A FEW MID LEVEL RETURNS CREEPING INTO THE SOUTHWEST
PORTION OF THE AREA. HOWEVER...BASES REMAIN MUCH TOO HIGH TO ALLOW
FOR AND PRECIPITATION REACHING THE GROUND. PRECIPITATION IS
ATTEMPTING TO PUSH INTO CENTRAL KENTUCKY THIS MORNING...BUT IS MAKING
VERY SLOW PROGRESS. THE LATEST RAP AND NAM SUGGEST A LATER ONSET OF
PRECIPITATION TODAY...POSSIBLY HOLDING OFF UNTIL 7 OR 8 PM THIS
EVENING FOR MUCH OF THE AREA. THE I-75 CORRIDOR MAY SEE THINGS START
A BIT EARLY TOWARDS 5 OR 6 PM. THESE TRENDS MAY NEED TO BE WATCHED.
WITH INSTABILITY ALREADY IN QUESTION...A LATER ONSET TOWARDS MID TO
LATE EVENING MAY LIMIT THE SEVERE THREAT AS INSTABILITY MAY SIMPLY
NOT BE THERE. IN FACT...THE LATEST HRRR SHOWS PRETTY ROBUST
CONVECTION TO THE SOUTH OF THE AREA BY MID AFTERNOON...SUGGESTING
THAT THE EARLIER ASSUMPTION ABOUT STORMS TO THE SOUTH ROBBING US OF
OUR INSTABILITY MAY BE TRUE. THESE TRENDS WILL HAVE TO BE MONITORED
THIS MORNING. CLEARLY...THIS IS NOT A CLEAR CUT SCENARIO FOR SEVERE
WEATHER. HAVE MADE SOME MINOR TWEAKS TO THE LATEST
TEMPERATURE/DEWPOINT CURVES...AND ADJUSTED SLIGHTLY THE ONSET OF
PRECIPITATION. NO NEED TO UPDATE THE FORECAST THROUGH.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 316 AM EDT THU APR 11 2013
STRONG COLD FRONT CURRENTLY EXTENDS FROM NORTHERN INDIANA...SOUTHWARD
INTO FAR WESTERN KENTUCKY. A LINE OF SHOWERS AND STORMS CONTINUES TO
PUSH EAST ALONG THIS FRONTAL BOUNDARY. MODELS ARE ALL IN PRETTY GOOD
AGREEMENT WITH THE POSITION AND TIMING OF THIS FRONT AS IT CROSSES
EASTERN KENTUCKY LATER TODAY. UNIDIRECTIONAL WIND SHEAR IS SUFFICIENT
TO WARRANT A WIND THREAT WITH ANY THUNDERSTORMS THAT DEVELOP. LCL`S
MAY GET LOW ENOUGH IN THE CUMBERLAND PLATEAU TO SUPPORT AN ISOLATED
TORNADO...BUT THOSE LCL`S GO WAY UP AS YOU GO NORTH AND EAST. ONSET
FOR PRECPITATION SHOULD BE SOMETIME AFTER 2 PM FOR MOST AREAS TODAY.
THE BIG QUESTION SURROUNDING SEVERE POTENTIAL IS WHETHER ENOUGH
INSTABILITY WILL EXISTS TO SUPPORT THUNDERSTORMS WITH STRONG
DOWNDRAFTS. USING SFC BASED PARCEL OF 80/58 PRODUCES AROUND 900J/KG
OF SBCAPE. ALTHOUGH THIS IS MARGINAL...IT SHOULD BE SUFFICIENT TO
SUPPORT THUNDERSTORMS AND THUS WE COULD SEE SOME STRAY DAMAGING WIND
GUSTS. THUS...WILL MAINTAIN THE SEVERE THREAT WORDING IN THE HWO. THE
POTENTIAL DOES EXIST THAT CONVECTION DEVELOPING TO OUR SOUTH LATER
THIS AFTERNOON COULD ROB EASTERN KENTUCKY AND LIMIT THE SEVERE THREAT
OVER THE AREA. HOWEVER...THIS WOULD BE TOUGH TO BASE A FORECAST
ON...SO GOING TO MAINTAIN THE SEVERE THREAT.
SEVERE THREAT WILL COME TO AN END BY MIDNIGHT AS COLD FRONT PUSHES
EAST OUT OF THE AREA. RAIN WILL EVENTUALLY END FROM WEST TO EAST
OVERNIGHT. SYSTEM SHOULD BE PROGRESSIVE ENOUGH TO LIMIT ANY
SIGNIFICANT FLOODING ISSUE...ESPECIALLY WITH THE LACK OF RECENT
RAINFALL. SIGNIFICANTLY COOLER WEATHER WILL RETURN TO THE AREA LATE
TONIGHT. THE MORE SIGNIFICANT COLD AIR STAYS TO OUR NORTHWEST ON
FRIDAY. ALTHOUGH TEMPERATURES WILL BE COOLER...AFTERNOON READINGS MAY
STILL CLIMB INTO THE LOWER 60S UNDER SUNSHINE. SOME LOW CLOUDS MAY
START THE DAY...BUT GUSTY SOUTHWEST WINDS SHOULD ERODE THESE CLOUDS
FAIRLY QUICKLY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 AM EDT THU APR 11 2013
THE MODELS ARE IN REASONABLY GOOD AGREEMENT THROUGH THE EXTENDED AND
ONLY START TO SIGNIFICANTLY DIVERGE TOWARD THE END. THE ALL AGREE
THAT A DEEP CLOSED LOW OVER THE GREAT LAKES WILL ROTATE OUT OF THE
AREA TO THE NORTHEAST. THIS PROCESS IS FACILITATED BY A DECENT
SHORTWAVE THAT WILL TRACK THROUGH THE OHIO VALLEY ON SATURDAY...WITH
THE ECMWF REPRESENTING A GOOD COMPROMISE BETWEEN THE SLOWER GEM AND
FASTER GFS. HEIGHTS WILL RISE IN THE WAKE OF THE UPPER LOW/S
DEPARTURE WITH A HINT OF RIDGING TAKING PLACE TO CLOSE OUT THE
WEEKEND. TO THE SOUTH OF THE AREA...A LOOSE CLUSTER OF ENERGY WILL
DRIFT PAST LATER THAT NIGHT AND MAY BE ENOUGH TO HAVE AN EFFECT ON
THE SENSIBLE WEATHER OF SOUTHEAST KENTUCKY. OTHERWISE...RENEWED
RIDGING WILL TAKE SHAPE OVER SOUTHEAST PORTION OF THE NATION
RESULTING IN RISING HEIGHTS THROUGH TUESDAY. THE MODELS ARE HINTING
THAT THIS PATTERN MAY BREAK DOWN LATER IN THE WEEK AS TROUGHING OUT
WEST STARTS TO MOVE EAST INTO THE PLAINS ON WEDNESDAY...FASTEST IN
THE GFS WHEN COMPARED TO THE 12Z ECMWF. IN ADDITION...A FEW WEAKER
PATCHES OF ENERGY WILL LIKELY START TO MAKE THEIR WAY THROUGH THE
REGION OUT AHEAD OF THE LARGER...INBOUND...SYSTEM.
SENSIBLE WEATHER WILL FEATURE A BRIEF COOL DOWN FOR THE START OF THE
WEEKEND AS HIGH PRESSURE SETTLES INTO THE AREA FOLLOWING THE LARGER
LOW PRESSURE SYSTEM EXITING TO THE NORTHEAST. THIS HIGH WILL QUICKLY
MODERATE...THOUGH...SO THAT EACH AFTERNOON WE CAN EXPECT
TEMPERATURES A FEW DEGREES HIGHER THAN THE PREVIOUS ONE THROUGH
TUESDAY. MORE IN THE WAY OF CLOUDS AND A BETTER POTENTIAL FOR
SHOWERS AND THUNDERSTORMS...LIKE A SUMMER TIME DIURNAL CONVECTIVE
PATTERN...MAY KEEP TEMPS A BIT LOWER ON WEDNESDAY THAN TUESDAY. THIS
POTENTIAL AND THE UNCERTAINTY OF THE TIMING FOR THE NEXT SYSTEM
MIDWEEK CALLS FOR LOW TO MID RANGE POP CHANCES FOR WEDNESDAY. THE
REST OF THE EXTENDED WILL LIKELY BE DRY...THOUGH CAN/T RULE OUT A
STRAY SHOWER EARLY MONDAY AS A WEAK SFC WAVE PASSES BY TO THE
SOUTH.
THE CR GRID LOAD CAME IN PRETTY DECENT...BUT DID NUDGE DOWN POPS
TUESDAY AND WEDNESDAY MORE TOWARDS THE 12Z ECMWF. ALSO MAKE SOME
SIGNIFICANT TERRAIN BASED ADJUSTMENTS FOR LOWS EACH NIGHT...
ANTICIPATING DECENT RIDGE TO VALLEY SPLITS THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 650 AM EDT THU APR 11 2013
HIGH/MID CLOUDS CONTINUE TO STREAM EAST ACROSS THE AREA. VFR
CONDITIONS SHOULD CONTINUE AT THE TAF SITES INTO MIDDAY TODAY. WINDS
WILL TURN GUSTY OUT OF THE SOUTH-SOUTHWEST BY LATE MORNING INTO THE
AFTERNOON AS A COLD FRONT ARRIVES FROM THE WEST. SHOWERS AND
THUNDERSTORMS SHOULD PUSH INTO CENTRAL AND EASTERN KENTUCKY AS EARLY
AS 20Z OR 21Z. CIGS SHOULD REMAIN ELEVATED INITIALLY. A FEW SEVERE
WIND GUSTS ARE POSSIBLE WITH ANY THUNDERSTORMS TODAY. AS THE FRONT
PASSES THIS EVENING...LOW LEVEL MOISTURE WILL SURGE EAST ACROSS THE
AREA DROPPING CIGS TO MVFR...THEN EVENTUALLY IFR LATER ON. RAIN
SHOULD PERSIST INTO THE FIRST HALF OF TONIGHT AS WELL...WHICH COULD
AID IN SOME PATCHY FOG FORMATION RESTRICTING VISIBILITIES AT TIMES.
STRATUS BUILD DOWN COULD OCCUR ONTO THE RIDGES WHICH MAY DROP
VISIBILITIES TO A QUARTER MILE OR LESS ON THE RIDGETOPS TONIGHT.
CLEARLY...LESS THAN IDEAL FLYING CONDITIONS WILL BE FOUND ACROSS
EASTERN KENTUCKY TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
650 AM EDT THU APR 11 2013
.UPDATE...
ISSUED AT 650 AM EDT THU APR 11 2013
STARTING TO SEE A FEW MID LEVEL RETURNS CREEPING INTO THE SOUTHWEST
PORTION OF THE AREA. HOWEVER...BASES REMAIN MUCH TOO HIGH TO ALLOW
FOR AND PRECIPITATION REACHING THE GROUND. PRECIPITATION IS
ATTEMPTING TO PUSH INTO CENTRAL KENTUCKY THIS MORNING...BUT IS MAKING
VERY SLOW PROGRESS. THE LATEST RAP AND NAM SUGGEST A LATER ONSET OF
PRECIPITATION TODAY...POSSIBLY HOLDING OFF UNTIL 7 OR 8 PM THIS
EVENING FOR MUCH OF THE AREA. THE I-75 CORRIDOR MAY SEE THINGS START
A BIT EARLY TOWARDS 5 OR 6 PM. THESE TRENDS MAY NEED TO BE WATCHED.
WITH INSTABILITY ALREADY IN QUESTION...A LATER ONSET TOWARDS MID TO
LATE EVENING MAY LIMIT THE SEVERE THREAT AS INSTABILITY MAY SIMPLY
NOT BE THERE. IN FACT...THE LATEST HRRR SHOWS PRETTY ROBUST
CONVECTION TO THE SOUTH OF THE AREA BY MID AFTERNOON...SUGGESTING
THAT THE EARLIER ASSUMPTION ABOUT STORMS TO THE SOUTH ROBBING US OF
OUR INSTABILITY MAY BE TRUE. THESE TRENDS WILL HAVE TO BE MONITORED
THIS MORNING. CLEARLY...THIS IS NOT A CLEAR CUT SCENARIO FOR SEVERE
WEATHER. HAVE MADE SOME MINOR TWEAKS TO THE LATEST
TEMPERATURE/DEWPOINT CURVES...AND ADJUSTED SLIGHTLY THE ONSET OF
PRECIPITATION. NO NEED TO UPDATE THE FORECAST THROUGH.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 316 AM EDT THU APR 11 2013
STRONG COLD FRONT CURRENTLY EXTENDS FROM NORTHERN INDIANA...SOUTHWARD
INTO FAR WESTERN KENTUCKY. A LINE OF SHOWERS AND STORMS CONTINUES TO
PUSH EAST ALONG THIS FRONTAL BOUNDARY. MODELS ARE ALL IN PRETTY GOOD
AGREEMENT WITH THE POSITION AND TIMING OF THIS FRONT AS IT CROSSES
EASTERN KENTUCKY LATER TODAY. UNIDIRECTIONAL WIND SHEAR IS SUFFICIENT
TO WARRANT A WIND THREAT WITH ANY THUNDERSTORMS THAT DEVELOP. LCL`S
MAY GET LOW ENOUGH IN THE CUMBERLAND PLATEAU TO SUPPORT AN ISOLATED
TORNADO...BUT THOSE LCL`S GO WAY UP AS YOU GO NORTH AND EAST. ONSET
FOR PRECPITATION SHOULD BE SOMETIME AFTER 2 PM FOR MOST AREAS TODAY.
THE BIG QUESTION SURROUNDING SEVERE POTENTIAL IS WHETHER ENOUGH
INSTABILITY WILL EXISTS TO SUPPORT THUNDERSTORMS WITH STRONG
DOWNDRAFTS. USING SFC BASED PARCEL OF 80/58 PRODUCES AROUND 900J/KG
OF SBCAPE. ALTHOUGH THIS IS MARGINAL...IT SHOULD BE SUFFICIENT TO
SUPPORT THUNDERSTORMS AND THUS WE COULD SEE SOME STRAY DAMAGING WIND
GUSTS. THUS...WILL MAINTAIN THE SEVERE THREAT WORDING IN THE HWO. THE
POTENTIAL DOES EXIST THAT CONVECTION DEVELOPING TO OUR SOUTH LATER
THIS AFTERNOON COULD ROB EASTERN KENTUCKY AND LIMIT THE SEVERE THREAT
OVER THE AREA. HOWEVER...THIS WOULD BE TOUGH TO BASE A FORECAST
ON...SO GOING TO MAINTAIN THE SEVERE THREAT.
SEVERE THREAT WILL COME TO AN END BY MIDNIGHT AS COLD FRONT PUSHES
EAST OUT OF THE AREA. RAIN WILL EVENTUALLY END FROM WEST TO EAST
OVERNIGHT. SYSTEM SHOULD BE PROGRESSIVE ENOUGH TO LIMIT ANY
SIGNIFICANT FLOODING ISSUE...ESPECIALLY WITH THE LACK OF RECENT
RAINFALL. SIGNIFICANTLY COOLER WEATHER WILL RETURN TO THE AREA LATE
TONIGHT. THE MORE SIGNIFICANT COLD AIR STAYS TO OUR NORTHWEST ON
FRIDAY. ALTHOUGH TEMPERATURES WILL BE COOLER...AFTERNOON READINGS MAY
STILL CLIMB INTO THE LOWER 60S UNDER SUNSHINE. SOME LOW CLOUDS MAY
START THE DAY...BUT GUSTY SOUTHWEST WINDS SHOULD ERODE THESE CLOUDS
FAIRLY QUICKLY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 AM EDT THU APR 11 2013
THE MODELS ARE IN REASONABLY GOOD AGREEMENT THROUGH THE EXTENDED AND
ONLY START TO SIGNIFICANTLY DIVERGE TOWARD THE END. THE ALL AGREE
THAT A DEEP CLOSED LOW OVER THE GREAT LAKES WILL ROTATE OUT OF THE
AREA TO THE NORTHEAST. THIS PROCESS IS FACILITATED BY A DECENT
SHORTWAVE THAT WILL TRACK THROUGH THE OHIO VALLEY ON SATURDAY...WITH
THE ECMWF REPRESENTING A GOOD COMPROMISE BETWEEN THE SLOWER GEM AND
FASTER GFS. HEIGHTS WILL RISE IN THE WAKE OF THE UPPER LOW/S
DEPARTURE WITH A HINT OF RIDGING TAKING PLACE TO CLOSE OUT THE
WEEKEND. TO THE SOUTH OF THE AREA...A LOOSE CLUSTER OF ENERGY WILL
DRIFT PAST LATER THAT NIGHT AND MAY BE ENOUGH TO HAVE AN EFFECT ON
THE SENSIBLE WEATHER OF SOUTHEAST KENTUCKY. OTHERWISE...RENEWED
RIDGING WILL TAKE SHAPE OVER SOUTHEAST PORTION OF THE NATION
RESULTING IN RISING HEIGHTS THROUGH TUESDAY. THE MODELS ARE HINTING
THAT THIS PATTERN MAY BREAK DOWN LATER IN THE WEEK AS TROUGHING OUT
WEST STARTS TO MOVE EAST INTO THE PLAINS ON WEDNESDAY...FASTEST IN
THE GFS WHEN COMPARED TO THE 12Z ECMWF. IN ADDITION...A FEW WEAKER
PATCHES OF ENERGY WILL LIKELY START TO MAKE THEIR WAY THROUGH THE
REGION OUT AHEAD OF THE LARGER...INBOUND...SYSTEM.
SENSIBLE WEATHER WILL FEATURE A BRIEF COOL DOWN FOR THE START OF THE
WEEKEND AS HIGH PRESSURE SETTLES INTO THE AREA FOLLOWING THE LARGER
LOW PRESSURE SYSTEM EXITING TO THE NORTHEAST. THIS HIGH WILL QUICKLY
MODERATE...THOUGH...SO THAT EACH AFTERNOON WE CAN EXPECT
TEMPERATURES A FEW DEGREES HIGHER THAN THE PREVIOUS ONE THROUGH
TUESDAY. MORE IN THE WAY OF CLOUDS AND A BETTER POTENTIAL FOR
SHOWERS AND THUNDERSTORMS...LIKE A SUMMER TIME DIURNAL CONVECTIVE
PATTERN...MAY KEEP TEMPS A BIT LOWER ON WEDNESDAY THAN TUESDAY. THIS
POTENTIAL AND THE UNCERTAINTY OF THE TIMING FOR THE NEXT SYSTEM
MIDWEEK CALLS FOR LOW TO MID RANGE POP CHANCES FOR WEDNESDAY. THE
REST OF THE EXTENDED WILL LIKELY BE DRY...THOUGH CAN/T RULE OUT A
STRAY SHOWER EARLY MONDAY AS A WEAK SFC WAVE PASSES BY TO THE
SOUTH.
THE CR GRID LOAD CAME IN PRETTY DECENT...BUT DID NUDGE DOWN POPS
TUESDAY AND WEDNESDAY MORE TOWARDS THE 12Z ECMWF. ALSO MAKE SOME
SIGNIFICANT TERRAIN BASED ADJUSTMENTS FOR LOWS EACH NIGHT...
ANTICIPATING DECENT RIDGE TO VALLEY SPLITS THROUGH THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 650 AM EDT THU APR 11 2013
HIGH/MID CLOUDS CONTINUE TO STREAM EAST ACROSS THE AREA. VFR
CONDITIONS SHOULD CONTINUE AT THE TAF SITES INTO MIDDAY TODAY. WINDS
WILL TURN GUSTY OUT OF THE SOUTH-SOUTHWEST BY LATE MORNING INTO THE
AFTERNOON AS A COLD FRONT ARRIVES FROM THE WEST. SHOWERS AND
THUNDERSTORMS SHOULD PUSH INTO CENTRAL AND EASTERN KENTUCKY AS EARLY
AS 20Z OR 21Z. CIGS SHOULD REMAIN ELEVATED INITIALLY. A FEW SEVERE
WIND GUSTS ARE POSSIBLE WITH ANY THUNDERSTORMS TODAY. AS THE FRONT
PASSES THIS EVENING...LOW LEVEL MOISTURE WILL SURGE EAST ACROSS THE
AREA DROPPING CIGS TO MVFR...THEN EVENTUALLY IFR LATER ON. RAIN
SHOULD PERSIST INTO THE FIRST HALF OF TONIGHT AS WELL...WHICH COULD
AID IN SOME PATCHY FOG FORMATION RESTRICTING VISIBILITIES AT TIMES.
STRATUS BUILD DOWN COULD OCCUR ONTO THE RIDGES WHICH MAY DROP
VISIBILITIES TO A QUARTER MILE OR LESS ON THE RIDGETOPS TONIGHT.
CLEARLY...LESS THAN IDEAL FLYING CONDITIONS WILL BE FOUND ACROSS
EASTERN KENTUCKY TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
801 PM EDT FRI APR 12 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN
WI WITH SHORTWAVE SPOKES INTO SRN UPPER MI AND WRN LAKE SUPERIOR.
WIDESPREAD LIGHT SNOW (VSBY IN THE 1-4SM RANGE) STILL PREVAILED
ACROSS MUCH OF UPPER MI WITH THE FAVORABLE UPPER LEVEL DIV AND
700-300 MB QVECTOR CONV TO THE NORTH OF THE LOW. AT THE SFC...LOW
PRES WAS LOCATED OVER NW LOWER MI NEAR TVC WITH A TROUGH EXTENDING
TO THE EAST TO LAKE ONTARIO. WITH THE SFC-850 MB TROUGH EDGING
CLOSER TO THE AREA...THE ENE LOW LEVEL FLOW HAD DIMINISHED. EVEN
WITH 850 MB TEMPS DOWN TO AROUND -11C...RADAR SHOWED ONLY MINIMAL IF
ANY LAKE ENHANCEMENT INTO N CNTRL UPPER MI.
EXPECT LIGHT SNOW ASSOCIATED WITH THE MID LEVEL LOW TO PERSIST THIS
EVENING BUT WITH ACCUMULATIONS OF LESS THAN AN INCH. WITH THE LOW
LEVEL TROUGH AXIS SHIFTING TO NEAR E UPPER MI...LOW LEVEL CONV FOR
LAKE ENHANCED SNOW WILL BE LESS FAVORABLE THIS EVENING. HOWEVER...AS
THE TROUGH SHIFTS TO THE EAST AND WINDS BACK MORE NRLY AND STRENGTHEN
OVERNIGHT INTO SATURDAY MORNING...LAKE ENHANCED SNOW IS EXPECTED TO
BECOME HEAVIER OVER THE WEST AND THEN SHIFT INTO N CNTRL UPPER MI
LATE TONIGHT INTO SATURDAY MORNING. EVEN WITH ONLY MARGINAL 850 MB
TEMPS NEAR -12C AND LAKE INDUCED CAPES TO NEAR 300 J/KG...ABUNDANT
850-500 MB MOISTURE AND CYCLONIC LOW LEVEL FLOW WILL FAVOR AT LEAST
LIGHT TO MODERATE SNOW. SNOW/WATER RATIOS SHOULD ALSO BECOME MORE
FAVORABLE WITH SIGNIFICANT UPWARD MOTION IN THE 850-750 MB DGZ LAYER.
EVEN WITH THE SNOW TAPERING OFF FOR A TIME TONIGHT...THE ADVISORIES
OVER THE NW HALF WERE EXTENDED INTO SATURDAY WITH HIGHER SNOWFALL
RATES AGAIN DEVELOPING. ADDITIONAL AMOUNTS FROM 00Z-18Z SHOULD STILL
REMAIN IN THE 2 TO 6 INCH RANGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
THE LONG RANGE LOOKS TO FEATURE AN WX ACTIVE PATTERN WITH BLO NORMAL
TEMPS OVERALL AS MEAN UPR TROF OVER CENTRAL NAMERICA LINGERS. MAIN
FOCUS WL BE ON NEXT LO PRES DISTURBANCE PROGGED TO IMPACT THE CWA
LATE SUN THRU SUN NGT.
SAT NGT...SHRTWV RDG AXIS BTWN DEPARTING/WEAKENING CLOSED LO OVER SE
CANADA AND NEXT SHRTWV/SFC LO MOVING INTO THE NRN PLAINS IS FCST TO
BLD INTO THE GRT LKS. WITH ARRIVAL OF SFC HI PRES RDG/DRYING ALF
UNDER THE RISING HGTS...LINGERING -SHSN UNDER MORE PERSISTENT CYC NW
FLOW/DEEPER MSTR/H85 TEMPS AS LO AS -10C IN THE EVNG OVER THE
NCENTRAL AND E WL END AND GIVE WAY TO AT LEAST PARTIAL CLRG.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY ON SUN WITH SFC HI PRES
RDG SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/SW FLOW BTWN THE
DEPARTING HI AND NEXT SHRTWV/SFC LO MOVING THRU THE NRN PLAINS AND
TOWARD MN LATE ON SUN OVERSPREADS UPR MI. AS UPR DVGC/BAND OF H5-7
FGEN AHEAD OF ATTENDANT WARM FNT MOVES IN AFT 18Z...EXPECT PCPN TO
OVERSPREAD THE CWA BY 00Z MON. PTYPE WL BE A CONCERN AT THE ONSET OF
THE PCPN EVENT SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED
TEMP PROFILE WL AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN
SHOW ELEVATED WARM LYR ABV SUB ZERO NEAR SFC LYR. IN FACT...THESE
FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH SOME ZR FOR A
TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER TERRAIN OF THE W
HALF. BUT THESE SDNGS ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE
AFTN FOLLOWING AT LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL
DRY AIR...EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB
TEMPS. BUT THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES
CENTER OVER ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME
THIS LATE IN THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT.
HIER MOS TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 50-60KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH H85
TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NEGATIVELY TILTED
APPEARANCE OF SHRTWV/VERY DIFFLUENT SW FLOW ALF/MSTR SURGE WITH PWAT
FCST UP TO 1 INCH SUN EVNG...OR 200 PCT OF NORMAL...INDICATE QPF
NEARING 1 INCH IS ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF
LINGERING SN PILES MAY CAUSE SOME PONDING OF WATER. CONSIDERED
ADDING A CHC OF ELEVATED TS UNDER THE MOST IMPRESSIVE
MOISTENING/AXIS OF H85 LLJ...BUT FCST SDNGS SHOW H85-5 LAPSE RATES
NOT QUITE MOIST ADIABATIC. ARRIVAL OF DRY SLOT SUN NGT WL DIMINISH
POPS SW-NE AFTER THE EVNG.
MON...DRY SLOT ON THE SRN FLANK OF SHRTWV/SFC LO TRACKING ENEWD THRU
SRN ONTARIO WL END ANY LINGERING PCPN OVER THE E AND SCNTRL
ASSOCIATED WITH DEPARTING WARM CONVEYOR BELT. THE GFS IS MOST
AGGRESSIVE AT SHOWING SOME DEEPER MSTR/PCPN ON THE SE FLANK OF THE
UPR LO IMPACTING THE WRN ZNS...BUT BULK OF GUIDANCE INDICATES DEEPER
MSTR/PCPN WL REMAIN IN MN CLOSER TO LINGERING LO PRES TROF ON SW
FLANK OF LO DEPARTING TO THE NE. EXPECT AT LEAST PARTIAL SUNSHINE...
WHICH SHOULD BOOST MAX TEMPS INTO THE 40S AT MOST PLACES WITH H85
TEMPS FCST JUST A COUPLE DEGREES BLO 0C.
EXTENDED...DRYING/LLVL ACYC FLOW UNDER SLOWLY RISING HGTS BTWN
DEPARTING LO AND DEEPENING TROF IN THE ROCKIES WL BRING DRY WX AND
SEASONABLE TEMPS FOR MON NGT THRU TUE NGT. AS LO PRES LIFTS NEWD OUT
OF THE WRN TROF AND TOWARD THE GRT LKS ON WED INTO THU...ANOTHER
SGNFT MIXED PCPN EVENT APPEARS LIKELY. IF THE WELL CLUSTERED 00Z
ECMWF...CNDN...AND UKMET VERIFY...THE PTYPE WOULD BE MAINLY SN OVER
THE W HALF OF THE CWA WITH WARNING SN TOTALS LIKELY. THE 00Z/06Z/12Z
GFS ON THE OTHER HAND SHOWS A MUCH WEAKER LO TRACKING FARTHER TO THE
S AND MUCH LESS PCPN IMPACTING MAINLY THE SE HALF OF UPR MI. ALL
THESE SCENARIOS ARE WITHIN THE SPREAD SHOWN BY THE 00Z GFS ENSEMBLE
MEMBERS. COLDER AIR WITH SHSN WL FOLLOW ON FRI AS THE 00Z ECMWF
SHOWS H85 TEMPS TUMBLING TO -15C UNDER CYC NW FLOW LEFT IN THE WAKE
OF DEPARTING LO PRES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 758 PM EDT FRI APR 12 2013
WITH MID/UPPER LEVEL LOW DRIFTING ACROSS THE AREA...SCT/NMRS -SHSN
WILL CONTINUE TONIGHT INTO SAT MORNING. AT KIWD...EXPECT CONDITIONS
VARYING BTWN IFR/MVFR THIS EVENING WITH A GENERAL TREND TOWARD
PREVAILING IFR BY LATE EVENING AS WINDS BACK MORE NORTHERLY OVER THE
LAKE...INCREASING UPSLOPE INTO KIWD. WOULDN`T BE SURPRISED TO SEE
BRIEF LIFR AT TIMES. AT KCMX...IFR SHOULD PREVAIL THRU THE NIGHT
WITH SOME PERIODS OF LIFR. LIFR MAY BE MORE FREQUENT FOR A PERIOD
LATE EVENING/OVERNIGHT AS SFC TROF DRIFTS ACROSS THE AREA. AT
KSAW...EXPECT MVFR CONDITIONS SHOULD PREVAIL FOR MUCH OF THE NIGHT.
AS SFC TROF DROPS ACROSS THE AREA LATE TONIGHT...CONDITIONS SHOULD
FALL TO IFR. AT ALL SITES...EXPECT IMPROVEMENT TO MVFR LATE SAT
MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 445 PM EDT FRI APR 12 2013
AS LOW PRESSURE OVER LOWER MICHIGAN SLIDES TO THE EAST TONIGHT AND
SATURDAY...WINDS WILL DIMINISH. THIS OCCURS...WINDS WILL GRADUALLY
SHIFT TO THE NORTH-NORTHWEST THROUGH SATURDAY AS A LINGERING SURFACE
TROUGH ROTATES THROUGH LAKE SUPERIOR. ENE GALES LATE THIS AFTERNOON
WILL DIMINISH TO 20 TO 30 KT WINDS TONIGHT AND INTO THE 15 TO 25 KT
RANGE SATURDAY.
WINDS ON SAT NIGHT WILL TURN LIGHT WITH THE ARRIVAL OF A HI PRES
RIDGE. EXPECT INCREASING E WINDS UP TO 25 TO 30 KTS VEERING TO THE
SE ON SUN INTO SUN NIGHT AHEAD OF A LO PRES SYSTEM MOVING FROM THE
NORTHERN PLAINS TOWARD MN. NOT OUT OF THE QUESTION THERE COULD BE
SOME GALES DURING THIS EVENT. AS THIS LO PASSES THRU ONTARIO ON
MON/MON NIGHT AND THE PRES GRADIENT OVER LAKE SUP DIMINISHES...THE
WINDS WILL SUBSIDE WHILE VEERING TO THE S AND THEN W INTO TUE. EXPECT
THE WINDS TO SHIFT TO THE N BY WED AS HI PRES BUILDS IN CENTRAL
CANADA AND ANOTHER LO PRES SYSTEM MOVES NE THRU THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT SATURDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY UNTIL 11 AM EDT SATURDAY FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...ROLFSON
MARINE...JLB/KC
AREA FORECAST DISCUSSION...CORRECTED
NWS MARQUETTE MI
507 PM EDT FRI APR 12 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN
WI WITH SHORTWAVE SPOKES INTO SRN UPPER MI AND WRN LAKE SUPERIOR.
WIDESPREAD LIGHT SNOW (VSBY IN THE 1-4SM RANGE) STILL PREVAILED
ACROSS MUCH OF UPPER MI WITH THE FAVORABLE UPPER LEVEL DIV AND
700-300 MB QVECTOR CONV TO THE NORTH OF THE LOW. AT THE SFC...LOW
PRES WAS LOCATED OVER NW LOWER MI NEAR TVC WITH A TROUGH EXTENDING
TO THE EAST TO LAKE ONTARIO. WITH THE SFC-850 MB TROUGH EDGING
CLOSER TO THE AREA...THE ENE LOW LEVEL FLOW HAD DIMINISHED. EVEN
WITH 850 MB TEMPS DOWN TO AROUND -11C...RADAR SHOWED ONLY MINIMAL IF
ANY LAKE ENHANCEMENT INTO N CNTRL UPPER MI.
EXPECT LIGHT SNOW ASSOCIATED WITH THE MID LEVEL LOW TO PERSIST THIS
EVENING BUT WITH ACCUMULATIONS OF LESS THAN AN INCH. WITH THE LOW
LEVEL TROUGH AXIS SHIFTING TO NEAR E UPPER MI...LOW LEVEL CONV FOR
LAKE ENHANCED SNOW WILL BE LESS FAVORABLE THIS EVENING. HOWEVER...AS
THE TROUGH SHIFTS TO THE EAST AND WINDS BACK MORE NRLY AND STRENGTHEN
OVERNIGHT INTO SATURDAY MORNING...LAKE ENHANCED SNOW IS EXPECTED TO
BECOME HEAVIER OVER THE WEST AND THEN SHIFT INTO N CNTRL UPPER MI
LATE TONIGHT INTO SATURDAY MORNING. EVEN WITH ONLY MARGINAL 850 MB
TEMPS NEAR -12C AND LAKE INDUCED CAPES TO NEAR 300 J/KG...ABUNDANT
850-500 MB MOISTURE AND CYCLONIC LOW LEVEL FLOW WILL FAVOR AT LEAST
LIGHT TO MODERATE SNOW. SNOW/WATER RATIOS SHOULD ALSO BECOME MORE
FAVORABLE WITH SIGNIFICANT UPWARD MOTION IN THE 850-750 MB DGZ LAYER.
EVEN WITH THE SNOW TAPERING OFF FOR A TIME TONIGHT...THE ADVISORIES
OVER THE NW HALF WERE EXTENDED INTO SATURDAY WITH HIGHER SNOWFALL
RATES AGAIN DEVELOPING. ADDITIONAL AMOUNTS FROM 00Z-18Z SHOULD STILL
REMAIN IN THE 2 TO 6 INCH RANGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
THE LONG RANGE LOOKS TO FEATURE AN WX ACTIVE PATTERN WITH BLO NORMAL
TEMPS OVERALL AS MEAN UPR TROF OVER CENTRAL NAMERICA LINGERS. MAIN
FOCUS WL BE ON NEXT LO PRES DISTURBANCE PROGGED TO IMPACT THE CWA
LATE SUN THRU SUN NGT.
SAT NGT...SHRTWV RDG AXIS BTWN DEPARTING/WEAKENING CLOSED LO OVER SE
CANADA AND NEXT SHRTWV/SFC LO MOVING INTO THE NRN PLAINS IS FCST TO
BLD INTO THE GRT LKS. WITH ARRIVAL OF SFC HI PRES RDG/DRYING ALF
UNDER THE RISING HGTS...LINGERING -SHSN UNDER MORE PERSISTENT CYC NW
FLOW/DEEPER MSTR/H85 TEMPS AS LO AS -10C IN THE EVNG OVER THE
NCENTRAL AND E WL END AND GIVE WAY TO AT LEAST PARTIAL CLRG.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY ON SUN WITH SFC HI PRES
RDG SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/SW FLOW BTWN THE
DEPARTING HI AND NEXT SHRTWV/SFC LO MOVING THRU THE NRN PLAINS AND
TOWARD MN LATE ON SUN OVERSPREADS UPR MI. AS UPR DVGC/BAND OF H5-7
FGEN AHEAD OF ATTENDANT WARM FNT MOVES IN AFT 18Z...EXPECT PCPN TO
OVERSPREAD THE CWA BY 00Z MON. PTYPE WL BE A CONCERN AT THE ONSET OF
THE PCPN EVENT SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED
TEMP PROFILE WL AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN
SHOW ELEVATED WARM LYR ABV SUB ZERO NEAR SFC LYR. IN FACT...THESE
FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH SOME ZR FOR A
TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER TERRAIN OF THE W
HALF. BUT THESE SDNGS ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE
AFTN FOLLOWING AT LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL
DRY AIR...EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB
TEMPS. BUT THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES
CENTER OVER ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME
THIS LATE IN THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT.
HIER MOS TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 50-60KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH H85
TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NEGATIVELY TILTED
APPEARANCE OF SHRTWV/VERY DIFFLUENT SW FLOW ALF/MSTR SURGE WITH PWAT
FCST UP TO 1 INCH SUN EVNG...OR 200 PCT OF NORMAL...INDICATE QPF
NEARING 1 INCH IS ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF
LINGERING SN PILES MAY CAUSE SOME PONDING OF WATER. CONSIDERED
ADDING A CHC OF ELEVATED TS UNDER THE MOST IMPRESSIVE
MOISTENING/AXIS OF H85 LLJ...BUT FCST SDNGS SHOW H85-5 LAPSE RATES
NOT QUITE MOIST ADIABATIC. ARRIVAL OF DRY SLOT SUN NGT WL DIMINISH
POPS SW-NE AFTER THE EVNG.
MON...DRY SLOT ON THE SRN FLANK OF SHRTWV/SFC LO TRACKING ENEWD THRU
SRN ONTARIO WL END ANY LINGERING PCPN OVER THE E AND SCNTRL
ASSOCIATED WITH DEPARTING WARM CONVEYOR BELT. THE GFS IS MOST
AGGRESSIVE AT SHOWING SOME DEEPER MSTR/PCPN ON THE SE FLANK OF THE
UPR LO IMPACTING THE WRN ZNS...BUT BULK OF GUIDANCE INDICATES DEEPER
MSTR/PCPN WL REMAIN IN MN CLOSER TO LINGERING LO PRES TROF ON SW
FLANK OF LO DEPARTING TO THE NE. EXPECT AT LEAST PARTIAL SUNSHINE...
WHICH SHOULD BOOST MAX TEMPS INTO THE 40S AT MOST PLACES WITH H85
TEMPS FCST JUST A COUPLE DEGREES BLO 0C.
EXTENDED...DRYING/LLVL ACYC FLOW UNDER SLOWLY RISING HGTS BTWN
DEPARTING LO AND DEEPENING TROF IN THE ROCKIES WL BRING DRY WX AND
SEASONABLE TEMPS FOR MON NGT THRU TUE NGT. AS LO PRES LIFTS NEWD OUT
OF THE WRN TROF AND TOWARD THE GRT LKS ON WED INTO THU...ANOTHER
SGNFT MIXED PCPN EVENT APPEARS LIKELY. IF THE WELL CLUSTERED 00Z
ECMWF...CNDN...AND UKMET VERIFY...THE PTYPE WOULD BE MAINLY SN OVER
THE W HALF OF THE CWA WITH WARNING SN TOTALS LIKELY. THE 00Z/06Z/12Z
GFS ON THE OTHER HAND SHOWS A MUCH WEAKER LO TRACKING FARTHER TO THE
S AND MUCH LESS PCPN IMPACTING MAINLY THE SE HALF OF UPR MI. ALL
THESE SCENARIOS ARE WITHIN THE SPREAD SHOWN BY THE 00Z GFS ENSEMBLE
MEMBERS. COLDER AIR WITH SHSN WL FOLLOW ON FRI AS THE 00Z ECMWF
SHOWS H85 TEMPS TUMBLING TO -15C UNDER CYC NW FLOW LEFT IN THE WAKE
OF DEPARTING LO PRES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 150 PM EDT FRI APR 12 2013
EXPECT SCATTERED TO NUMEROUS SNOW SHOWERS THIS AFTERNOON INTO THIS
EVENING WITH VARIABLE VISIBILITIES WILL LIKELY BE BOUNCING BETWEEN 1
AND 4 MILES. FROM THIS AFTERNOON INTO THIS EVENING...LAKE
INFLUENCES WILL ENHANCE THE SNOW AT KCMX/KSAW AT TIMES. AS THE UPPER
LOW IS OVERHEAD AND THE SURFACE LOW MOVES NORTHEAST INTO
CANADA...WINDS WILL TURN MORE NORTHERLY TONIGHT AND LEAD MAINLY LAKE
ENHANCED SNOWFALL FOR ALL THREE SITES. VISIBILITIES WERE KEPT DOWN
DURING THAT PERIOD AND ALSO LOWERED CEILINGS DUE TO WINDS BECOMING
MORE FAVORABLE TO UPSLOPE. THE SNOW SHOULD TAPER OFF SATURDAY BUT
WILL LIKELY REMAIN IN THE LOWER MVFR RANGE INTO THE EARLY AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 445 PM EDT FRI APR 12 2013
AS LOW PRESSURE OVER LOWER MICHIGAN SLIDES TO THE EAST TONIGHT AND
SATURDAY...WINDS WILL DIMINISH. THIS OCCURS...WINDS WILL GRADUALLY
SHIFT TO THE NORTH-NORTHWEST THROUGH SATURDAY AS A LINGERING SURFACE
TROUGH ROTATES THROUGH LAKE SUPERIOR. ENE GALES LATE THIS AFTERNOON
WILL DIMINISH TO 20 TO 30 KT WINDS TONIGHT AND INTO THE 15 TO 25 KT
RANGE SATURDAY.
WINDS ON SAT NIGHT WILL TURN LIGHT WITH THE ARRIVAL OF A HI PRES
RIDGE. EXPECT INCREASING E WINDS UP TO 25 TO 30 KTS VEERING TO THE
SE ON SUN INTO SUN NIGHT AHEAD OF A LO PRES SYSTEM MOVING FROM THE
NORTHERN PLAINS TOWARD MN. NOT OUT OF THE QUESTION THERE COULD BE
SOME GALES DURING THIS EVENT. AS THIS LO PASSES THRU ONTARIO ON
MON/MON NIGHT AND THE PRES GRADIENT OVER LAKE SUP DIMINISHES...THE
WINDS WILL SUBSIDE WHILE VEERING TO THE S AND THEN W INTO TUE. EXPECT
THE WINDS TO SHIFT TO THE N BY WED AS HI PRES BUILDS IN CENTRAL
CANADA AND ANOTHER LO PRES SYSTEM MOVES NE THRU THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT SATURDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY UNTIL 11 AM EDT SATURDAY FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ084.
LAKE SUPERIOR...
GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB/KC
AREA FORECAST DISCUSSION
NWS GAYLORD MI
141 PM EDT FRI APR 12 2013
.SYNOPSIS...
ISSUED AT 350 AM EDT FRI APR 12 2013
SLOW MOVING...LOW PRESSURE IS LIFTING INTO THE UPPER GREAT LAKES
REGION AND WILL BRING A WINTRY MESS OF PRECIPITATION TYPES TO
NORTHERN MICHIGAN TODAY. THE FREEZING RAIN AND SLEET IS EXPECTED TO
TRANSITION OVER TO SNOW AND DRIZZLE THIS MORNING. THIS WILL CONTINUE
INTO THE EVENING BEFORE CHANGING TO ALL SNOW TONIGHT. HIGH PRESSURE
TRIES TO SNOW INTO THE REGION ON SATURDAY SO THAT WE WILL GET A
BREAK FOR THE WEEKEND.
&&
.UPDATE...
ISSUED AT 140 PM EDT FRI APR 12 2013
SHORT WAVE AND BATCH OF DEEPER MOISTURE HELPING TO DRIVE A ROUND
OF LIGHT SNOWFALL UP THROUGH NRN LOWER MICHIGAN CURRENTLY. EXPECT
THIS BATCH OF LIGHT PRECIP TO CONTINUE TO LIFT NORTHWARD THROUGH
THE AFTERNOON HOURS. COLDER AIR AND ANOTHER ROUND OF MOISTURE
ARRIVE TONIGHT WHILE LOW LEVEL MEAN WINDS SWING AROUND TO THE WEST
OFF THE LAKES. WILL ULTIMATELY GET SOME LIGHT LAKE SNOW SHOWERS
GOING LATER TONIGHT AS OVER LAKE INSTABILITY GRADUALLY INCREASES.
UPDATE ISSUED AT 1022 AM EDT FRI APR 12 2013
MAIN BATCH OF "WARM CONVEYOR" PRECIP HAS LIFTED NORTH/EAST OUT OF
THE CWA THIS MORNING...WHILE MID LEVEL DRY SLOT HAS PUNCHED UP
INTO NRN MICHIGAN (EVIDENT ON KAPX VAD WIND PROFILE). MAINLY JUST
SOME FLURRIES/DRIZZLE/FREEZING DRIZZLE OCCURRING AT THE MOMENT.
MAIN MID LEVEL SHORT WAVE SLOWLY ADVANCING NORTHEASTWARD ACROSS
WISCONSIN AND IS PRODUCING SOME ADDITIONAL LIGHT PRECIP THAT WILL
LIKELY IMPACT PARTS OF NORTHWEST LOWER AND EASTERN UPPER MICHIGAN
AS WE GO THROUGH THE AFTERNOON/EARLY EVENING. BUT OTHERWISE...MAIN
BATCH OF PRECIP IS DONE AND WINDS ARE WEAKENING. SO...WILL CANCEL
THE WINTER STORM WARNING FOR EASTERN UPPER MICHIGAN AHEAD OF
SCHEDULE.
UPDATE
ISSUED AT 712 AM EDT FRI APR 12 2013
ONGOING FORECAST IS PORTRAYING THE SCENE OUTSIDE PRETTY WELL. MAIN
SWATH OF PRECIPITATION IS WRAPPED FROM NE LOWER ACROSS EASTERN
UPPER. WITH COOLING OCCURRING THROUGHOUT THE ATMOSPHERE NOW...MOST
ALL AREAS HAVE SWITCHED OVER TO SNOW...OR LIGHT SNOW AND DRIZZLY
CONDITIONS UNDERNEATH DEEPER MOISTURE PEELING OFF TO THE EAST.
LATEST SATELLITE AND UPSTREAM SFC OBS SHOWING THAT EVERYONE IS
LIKELY TO GET INTO A PERIOD OR TWO OF DRIZZLE/FREEZING DRIZZLE. THE
WORST OF IT IS OVER NOW...AND WILL CANCEL THE WARNINGS FOR ALL BUT
EASTERN UPPER...WHERE SOME ADDITIONAL ACCUMULATIONS ARE
POSSIBLE...BUT EVEN HERE...DAY CREW MAY DECIDE TO END THE HEADLINES
BY LATE MORNING.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 350 AM EDT FRI APR 12 2013
CURRENTLY...POTENT UPPER LEVEL CLOSED LOW IS DRIFTING ACROSS THE
FAR NRN MISSISSIPPI VALLEY...WITH OCCLUDED LOW PRESSURE FROM THE
APPALACHIANS...AND TROUGHING/TROWAL EXTENDING BACK INTO SRN
WISCONSIN. MAIN H8-H7 WARM ADVECTION EXTENDS ALONG H8 WIND SPEED
MAX WHICH IS NOW EXTENDING FROM THE EASTERN GREAT LAKES BACK AROUND
THROUGH EASTERN UPPER MICHIGAN. THIS IS WHERE ONE SWATH OF BETTER
PRECIPITATION...IN THE FORM OF SNOW AND SOME SLEET...IS CO-LOCATED
WITH STRONG POCKET OF UPPER DIVERGENCE IN RIGHT ENTRANCE REGION OF
QUEBEC 120+KT UPPER JET. ANOTHER JET STREAK WAS CROSSING THE OHIO
RIVER VALLEY...AND ANOTHER POCKET OF UPPER DIVERGENCE IN LEFT EXIT
REGION OF WAS DEVELOPING ACROSS THE EASTERN GREAT LAKES. DPVA
AROUND THE CLOSED LOW ALOFT...COMBINED WITH THESE FORCING
MECHANISMS...HAS RESULTED IN MODEST TO STRONG DEEP LAYER LIFT AND
WIDESPREAD PRECIPITATION ACROSS MAINLY NE LOWER AND BACK AROUND
THROUGH EASTERN UPPER.
NOW...THERMALLY SPEAKING...WE HAVE GONE THROUGH QUITE ALONG PERIOD
OF SLEET AND FREEZING RAIN IN NRN LOWER...AS 00Z APX SOUNDING TELLS
THE STORY. 800-700MB DEEP 2-3C WARM NOSE IS EVIDENT...WITH A
COUNTERING DEEP SFC-800MB COLD LAYER WITH A MAXIMUM -6C READING AT
900MB...COLD ENOUGH TO RE-FREEZE TOTALLY MELTED DROPS FROM THAT 2-3C
DEEP WARM NOSE. ONE OF THE BETTER SLEET SOUNDINGS THIS FORECASTER
HAS SEEN. AS THE ENTIRE SYSTEM HAS BEEN SLOW TO TRANSITION NORTH AND
EAST WITH TIME...QUITE A BIT OF SLEET HAS BEEN ABLE TO FALL AND
ACCUMULATE. ACROSS EASTERN UPPER...SOME SLEET MAY BE TRYING TO MIX
WITH WHAT SHOULD BE PRIMARILY SNOW...BASED ON LATEST DUAL POL RADAR
LOOPING. RUC FCST SOUNDINGS ALSO SUGGEST ALL SNOW IN EASTERN
UPPER...WITH THE ELEVATED WARM COOLING STARTING AS OF THIS WRITING.
LATEST OBS SUGGESTING THAT THIS MAY BE TAKING PLACE NOW WITH MORE
OBSERVATIONS ACROSS THE WEST NOW LOOKING MORE "SNOWY" RATHER THAN
"ICY". ALSO IN THE MIX...IS THE CURRENT EFFORT FOR DEEPER MOISTURE
TO STRIP OUT ALOFT FROM THE WEST...WHICH ALLOWS US TO EXPERIENCE YET
ANOTHER PRECIPITATION TYPE...DRIZZLE AND FREEZING DRIZZLE.
IT SHOULD BE WORTH NOTING THAT NOT ALL FOLKS HAVE EXPERIENCED THIS
PLETHORA OF NASTY WINTRY WEATHER. DOWNSLOPING REGIONS ACROSS NW
LOWER...MAINLY FRANKFORT AND MANISTEE AREAS...WERE ABOVE FREEZING
FOR MUCH OF THE NIGHT...SO NOT FREEZING RAIN THERE.
IN THE SPIRIT OF A FORMER NWS COLLEAGUE..."WELL...AT LEAST IT`S
WINDY". YEAH...EAST WINDS WERE GUSTING AS HIGH AS 35-40 MPH MUCH OF
THE NIGHT TOO.
NOW...THE FORECAST...POTENT UPPER LOW WILL LIFT INTO EASTERN LAKE
SUPERIOR TODAY AND TONIGHT...WITH THE SFC TROUGHING/TROWAL AND
AXIS OF DEEPER MOISTURE AND FORCING LIFTING NORTH AND EAST
THROUGH THE MORNING. COLDER AIR SEEPS IN...AND THE TRANSITION OVER
TO MAINLY LIGHT SNOW WILL BE JOINED BY DRIZZLE AND FREEZING
DRIZZLE DUE TO DRYING ALOFT. THE THERMAL PROFILES BECOME AN
INCREASINGLY LIGHT SNOW/DRIZZLE LOOK...AS MOISTURE WILL BE AT OR
BELOW 10C FOR MOST OF THE DAY AND EVEN INTO THE EVENING. THE BEST
MOISTURE/FORCING WILL BE ACROSS CHIPPEWA COUNTY FOR THE LONGEST
PERIOD OF TIME. HERE...ALTHOUGH TOTAL QPF/SNOWFALL WERE LOWERED
SLIGHTLY...WILL STILL SEE A GRAND TOTAL OF 4 TO 8 INCHES BY THE
END OF THE DAY. LESSER AMOUNTS HEADING SOUTH UNTIL JUST AN INCH
DOWN NEAR THE M-55 CORRIDOR. CURRENT WINTER STORM HEADLINES WILL
HOLD TRUE...ENDING FROM SOUTH TO NORTH THROUGH THE DAY. LIGHT
SNOWS AND DRIZZLE ARE LIKELY AT LEAST INTO THE EVENING DUE TO THE
LOW LEVEL CONVERGENCE ASSOCIATED WITH THE ACTUAL SFC TROUGHING.
EVENTUALLY BY LATER TONIGHT...THE LOW LEVEL TROUGHING
WEAKENS/DEPARTS...WITH THE ENTIRE ATMOSPHERIC COLUMN COLD ENOUGH
FOR JUST SNOW. CAN MAKE A REAL GOOD ARGUMENT FOR LIKELY SNOWS FOR
MOST EVERYONE AT SOME POINT DURING THE NIGHT. THIS DUE NOT ONLY TO
THE LINGERING TROUGHING AT THE SFC...BUT ALSO WITH MID LEVEL
TROUGHING WITH THE UPPER CIRCULATIONS...WHICH WILL BE ALIGNED
ACROSS EASTERN UPPER. THUS...WILL HAVE THE BETTER ACCUMULATIONS
AND CHANCES FOR SNOW THERE. MAYBE ANOTHER INCH ACROSS EASTERN
UPPER...WITH LESSER AMOUNTS HEADING FURTHER SOUTH.
CLOUDY THROUGH THE PERIOD WITH LITTLE DIURNAL SWINGS IN
TEMPERATURE. HIGHS IN THE 30S TODAY...WITH LOWS IN THE MIDDLE 20S
TO LOWER 30S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 350 AM EDT FRI APR 12 2013
SATURDAY...AS THE 500 MB LOW DRIFTS EAST JUST NORTH OF THE FORECAST
AREA, THERE WILL BE ENOUGH FORCING TO CONTINUE THE SNOW SHOWERS.
HOWEVER, THE KICKER IS THAT THE 850 MB TEMPERATURES FALL TO AROUND
-10C AND WITH THE WATER TEMPERATURES SLIGHTLY WARMER AROUND +1 TO
+2C WE WILL PROBABLY GET SOME ENHANCEMENT ESPECIALLY NEARER THE SFC
AND 500 MB LOWS. SO WILL HAVE AN AREA OF LIKELY POPS IN E UPPER AND
ENHANCED CHANCE POPS IN NW LOWER. BY 00Z, THINGS BEGIN TO LOOK LIKE
LAKE EFFECT, HOWEVER, THE PROBLEM IS THAT THE 850 MB TEMPERATURES
BEGIN TO WARM BIT, AND WE LOSE THE ENHANCEMENT.
SATURDAY NIGHT...WE LOSE GOOD 850 MB AND SFC FLOW AS THE
TEMPERATURES RISE TO AROUND -8C. WILL ALLOW FOR SOME FLURRIES EARLY,
BUT ALL THINGS BEING EQUAL, THINK THAT THE WITH THE DRIER AIR MOVING
IN AS WELL, THAT THE SNOW WILL STOP SHORTLY HAVE 00Z.
SUNDAY...THE NEXT SYSTEM BEGINS TO LIFT NORTH INTO NORTHERN PLAINS.
THE GFS HAS IT A LITTLE MORE EAST IN MINNESOTA, WHILE THE 00Z ECMWF
HAS IT IN E NORTH DAKOTA. THE DIFFERENCE IS THAT THE GFS BRINGS
CHANCE POPS INTO NW LOWER SOONER. WITH THESE SYSTEMS BEING KIND OF
ALL OVER THE PLACE, IN THE RUN UP TO THEM, WILL HEDGE BETWEEN THE
TWO. SO CUT THE POPS BACK SO THAT NW LOWER HAVE SOME CHANCE POPS,
AND THE REST OF THE REGION IS RELATIVELY DRY. OVERNIGHT, THE WARM
FRONT IN EITHER CASE MAKES IT FAR ENOUGH NORTH RAIN TAKES OVER IN E
UPPER. THE FRONT STALLS THERE AS WELL SO THAT THE SFC LOW RIDES UP
INTO LAKE SUPERIOR ALONG IT. SO RAIN WILL BE EXPECTED IN E UPPER AND
WITH THE WARM SECTOR MOVING NORTH WILL HAVE LESS CHANCES TO THE
SOUTH.
EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, EXPECTING RAIN FROM THE
SYSTEM MOVING THROUGH DURING THE DAY. OVERNIGHT, WITH THE FRONT
THROUGH AND THE SFC LOW TO THE EAST, WILL EXPECT THAT E UPPER AND
PORTIONS OF N LOWER WILL CLEAR OUT AS HIGH PRESSURE BUILDS INTO THE
REGION. TUESDAY, THE FRONT HOLDS TO THE EAST WITH HIGH PRESSURE
NOSING INTO LOWER MICHIGAN. LOOKS LIKE SOME RAIN COULD HOLD ON WITH
WAVES RUNNING UP THE FRONT. SO WILL ALLOW FOR SOME RAIN IN NE
LOWER. WEDNESDAY, THE NEXT SYSTEM BEGINS TO PUSH OUT OF THE SOUTHERN
PLAINS AND BY THE TIME THAT IT GETS INTO THE MID-MISSISSIPPI VALLEY,
THE RAIN WILL SPREAD BACK NORTH THROUGH N LOWER AND IN E UPPER,
WHERE A MIX WILL BE EXPECTED. OF COURSE, THE WARM AIR WILL CONTINUE
NORTH CHANGING THE SNOW BACK TO RAIN OVERNIGHT. THURSDAY, THE MODELS
HAVE TWO DIFFERENT TRACKS. THE ECMWF STILL BRINGS THE SFC LOW OVER N
LOWER, WHICH WOULD BRING MORE RAIN TO THE REGION BEFORE CHANGING TO
SNOW THURSDAY NIGHT. THE GFS BRINGS THE SFC LOW UP THROUGH LAKE
ERIE. THIS WOULD BRING SNOW OR RAIN AND SNOW TO N LOWER AND E UPPER.
DECIDED TO PLAY AS RAIN THURSDAY, RAIN/SNOW THURSDAY NIGHT FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 140 PM EDT FRI APR 12 2013
TOUGH...LOWER CONFIDENCE AVIATION FORECAST THROUGH SATURDAY. JUST
SOME LIGHTER SNOW MOVING THROUGH NRN LOWER MICHIGAN CURRENTLY.
HOWEVER...VSBYS ARE FAIRLY LOW DUE TO FOG/MIST ACROSS THE REGION.
SFC LOW PRESSURE/TROUGH WILL TRACK UP THROUGH THE REGION THIS
EVENING RESULTING IN LIGHT WINDS. THIS WOULD SUGGEST THAT FOG/LOW
CLOUDS AND IFR CONDITIONS WILL BE THE RULE THROUGH TONIGHT.
WINDS TURN AROUND TO THE WEST LATER TONIGHT WITH COOLER AIR
BLEEDING BACK INTO THE REGION. THIS WILL ULTIMATELY GET SOME LIGHT
LAKE EFFECT SNOW SHOWERS GOING TOWARD MORNING AND PERSISTING INTO
SATURDAY.
LIGHT WINDS THROUGH TONIGHT...BUT INCREASING OUT OF THE WEST ON
SATURDAY WITH SOME GUSTS UP TO 20 KNOTS POSSIBLE SATURDAY AFTERNOON.
&&
.MARINE...
ISSUED AT 350 AM EDT FRI APR 12 2013
GALE FORCE GUSTS ARE IN FULL EFFECT ACROSS MOST OF THE SURROUNDING
NEARSHORE WATERS OF LAKES HURON AND MICHIGAN...NORTH OF GRAND
TRAVERSE LIGHT AND STURGEON POINT LIGHT. NORTH OF THERE...SOLID
ADVISORY LEVEL GUSTS WERE ONGOING...WHILE SOUTH OF THE
GALES...WINDS WERE DROPPING OFF RATHER QUICKLY WITH A LOOSE
GRADIENT ALONG LOW PRESSURE LIFTING NORTHWARD. THIS LIGHTER
GRADIENT WILL GRADUALLY OVERTAKE ALL OF THE NEARSHORE WATERS
THROUGH THE DAY...WITH GALES GRADUALLY STEPPING DOWN INTO
ADVISORY...THEN SUB ADVISORY LEVELS. THE LOW PRESSURE LIFTS EAST
TONIGHT...WITH COLD ADVECTION AND WESTERLY WINDS DEVELOPING...BUT
EXPECTATIONS ARE FOR WINDS TO BE BELOW ADVISORY LEVELS THROUGH
EARLY SUNDAY. THE NEXT LOW PRESSURE SYSTEM IS SET FOR LATER SUNDAY
AND INTO MONDAY. ADDITIONAL HEADLINES MAY BE REQUIRED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ323-341-
342-344.
LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...BA
SYNOPSIS...JL
SHORT TERM...SD
LONG TERM...JL
AVIATION...BA
MARINE...SD
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
709 PM CDT FRI APR 12 2013
.AVIATION...00Z TAF ISSUANCE...
CENTER OF UPPER LOW IS MOVING INTO THE UPPER PENINSULA OF MICHIGAN
EARLY THIS EVENING. HOWEVER..DEFORMATION ZONE CONTINUES TO EXTEND
WESTWARD FROM THE UPPER LOW CENTER ACROSS MUCH OF NORTHEAST
MINNESOTA AND NORTHWEST WISCONSIN..AND FORCING FOR ASCENT IN THIS
ZONE WILL CONTINUE TO PRODUCE RATHER WIDESPREAD LIGHT SNOW ACROSS
ALL TERMINAL SITES FOR THE FIRST FEW HOURS OF THIS TAF
PERIOD..ALONG WITH WIDESPREAD MVFR CEILINGS. LIGHT SNOW SHOULD
DIMINISH FROM WEST TO EAST BETWEEN 03-08Z AT MOST TERMINALS.
HOWEVER..PRECIP MAY HANG ON A LITTLE LONGER AT KDLH/KHYR IN CLOSER
PROXIMITY TO UPPER LOW AND DEFORMATION AXIS.
MAINLY MVFR CEILINGS ARE EXPECTED TO PERSIST OVERNIGHT AND SAT
MORNING..WITH A SLOW LIFTING OF CLOUD BASES DURING THE DAY
SATURDAY. HOWEVER..COMBINATION OF STEEP LOW LEVEL LAPSE
RATES/RESIDUAL BOUNDARY LAYER MOISTURE AND LIMITED HEATING
TOMORROW MAY RESULT IN THE DEVELOPMENT OF BROKEN MVFR/VFR
CUMULUS/STRATOCUMULUS DECK BEGINNING AROUND MIDDAY ALONG WITH
PERIODIC SNOW SHOWERS IN THE AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 345 PM CDT FRI APR 12 2013/
SHORT TERM...THROUGH SATURDAY.
WATER VAPOR SHOWS THE UPPER LOW MOVING NORTHEAST ACROSS NORTHERN
WISCONSIN THIS AFTERNOON...AND IT IS FORECAST TO MOVE OVER
EASTERN LAKE SUPERIOR TONIGHT...AND CONTINUE EAST ON SATURDAY.
LIGHT SNOW WILL LINGER TONIGHT...BUT BE MOST WIDESPREAD THROUGH
THE EVENING HOURS. INTENSITY OVERALL WILL BE LIGHT...BUT THERE
WILL BE PERIODS OF MODERATE SNOW WITH VSBYS DOWN TO AROUND A MILE
FOR A TIME. WE WENT WITH ADDITIONAL SNOWFALL AROUND AN INCH FOR
MOST AREAS...BUT WENT A BIT HIGHER OVER PORTIONS OF THE ARROWHEAD
AND ALONG THE SOUTH SHORE. THE SOUTH SHORE WILL GET INTO LAKE
ENHANCED SNOWFALL TONIGHT AS WINDS TURN NORTHERLY AND WITH 850MB
TEMPS FORECAST TO DROP TO AROUND -12C AND INVERSION LEVELS
INCREASE. THE SOUTH SHORE WILL HAVE TO BE WATCHED CLOSELY...IF
STABILITY IS LOWER THAN EXPECTED...SNOW RATES COULD GET HEAVY AT
TIMES ACROSS THE SNOWBELT OF ASHLAND/IRON COUNTIES. THE OTHER AREA
WE`LL HAVE TO MONITOR IS ACROSS NORTH CENTRAL DOUGLAS
COUNTY...SOUTHWEST TOWARD SOUTHEAST CARLTON COUNTIES. AS LOW LEVEL
WINDS BACK TO NORTHWEST TONIGHT...WE COULD SEE A GRAVITY WAVE
INDUCED BAND OF ENHANCED SNOWFALL DEVELOP. LOOKING AT A RAP CROSS
SECTION...A STRONG SIGNAL IS NOT SEEN ATTM.
LIGHT SNOW OR FLURRIES WILL LINGER INTO SATURDAY
MORNING...PARTICULARLY OVER THE EASTERN HALF OF THE CWA DUE TO THE
SLOW DEPARTURE OF THE UPPER LOW. HOWEVER...ADDITIONAL SNOWFALL
WILL BE QUITE LIGHT IF ANYTHING MEASURES AT ALL.
WE EXPECT HIGHS SATURDAY TO REACH THE 35 TO 40 FOR MOST AREAS.
LONG TERM...SATURDAY NIGHT - FRIDAY.
THE FOCUS IN THIS FORECAST IS THE WINTER STORM SYSTEM THAT IS
EXPECTED TO AFFECT THE NORTHLAND LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. THE MODELS CONTINUE TO INDICATE THAT A POTENT MID/UPPER LOW
PRESSURE SYSTEM AND ITS ASSOCIATED LOW PRESSURE SYSTEM AT THE
SURFACE WILL MOVE THROUGH THE NORTHERN PLAINS SUNDAY AND MOVE INTO
ONTARIO MONDAY.THE MODELS SEEM TO HAVE INCREASED THEIR SNOWFALL FOR
THIS SYSTEM FOR LATE SATURDAY NIGHT THROUGH MONDAY MORNING...AND
TRENDED A LITTLE COLDER. I STILL THINK THERE MAY BE A WINTRY MIX
ACROSS THE SOUTHERN FORECAST AREA DURING THE LATE MORNING AND AT
LEAST THE AFTERNOON DUE TO NOT ONLY WARMER SURFACE
TEMPERATURES...BUT INCREASING TEMPERATURES ALOFT. I DO NOT SEE ANY
SIGNIFICANT RISK OF FREEZING RAIN BASED ON THE SOUNDINGS...BUT WE
WILL NEED TO CONTINUALLY CHECK INTO THIS. THE WINTRY MIX ACROSS THE
SOUTH WILL LIKELY PREVENT MUCH ACCUMULATION OF SNOW...SO MOST OF THE
CONCERN IS FOR NE MINNESOTA FOR HEAVY SNOW WHERE TEMPERATURES WILL
BE COLDER. THIS STORM SYSTEM IS LOOKING MORE AND MORE LIKELY THAT IT
WILL BRING AT LEAST A WIDESPREAD 6 TO 8 INCHES ACROSS NE
MINNESOTA...ESPECIALLY NORTH OF HIGHWAY 2. SOME ARES OF FAR NORTHERN
MINNESOTA MAY GET UP TO 10 INCHES. I MAY BE ON THE HIGH SIDE WITH
THE STORM TOTAL SNOWFALL...SO I DO NOT IMAGINE AT THIS POINT THAT
THIS STORM WOULD YIELD MUCH MORE SNOW THAN THIS.
LIGHT SNOW COULD LINGER ACROSS NE MINNESOTA MONDAY INTO TUESDAY IN
THE WAKE OF THE STORM SYSTEM. BEYOND TUESDAY...PREVIOUS MODEL RUNS
HAD BEEN INDICATING THE POTENTIAL FOR ANOTHER WINTRY-WEATHER SYSTEM
MID TO LATE WEEK...BUT IT WAS GOING TO BE DEPENDENT THE TRACK OF THE
ASSOCIATED LOW PRESSURE SYSTEM. THE LATEST GFS AND ECMWF ARE BACKING
OFF ON HAVING THIS SYSTEM AFFECTING THE NORTHLAND IN THAT THEY HAVE
THE LOW TRACK VERY FAR SOUTH...BASICALLY FROM THE SOUTHERN PLAINS TO
MICHIGAN. HOWEVER...THE GEM HAS A TRACK THAT IS SIGNIFICANTLY
FARTHER NORTH AND STILL SUGGESTS THE POTENTIAL TO BRING SIGNIFICANT
SNOWFALL TO PARTS OF THE NORTHLAND MID TO LATE WEEK. UNTIL AND IF
THE GEM BACKS OFF ON THE SYSTEM...THAT WE STILL NEED TO CARRY PCPN
CHANCES FOR THE MID TO LATE WEEK.
OVERALL THE COLD WEATHER PATTERN IS EXPECTED TO CONTINUE OVER THE
UPCOMING WEEK.
AVIATION...18Z TAF ISSUANCE.
WIDESPREAD IFR/MVFR CIGS AND/OR VSBYS ARE EXPECTED ACROSS NE
MINNESOTA AND NW WISCONSIN THROUGH SATURDAY MORNING DUE TO LOW
CIGS AND LINGERING SNOW ACROSS THE REGION. THERE MAY BE PERIODS OF
LIFR CONDITIONS THIS AFTERNOON DUE TO REDUCED VSBY FROM HIGHER
SNOWFALL RATES...ESPECIALLY AT KDLH. THE 10 TO 20 KNOT NE WINDS
WILL WEAKEN AND BECOME N TO NNW TONIGHT. THERE MAY BE GRADUAL
IMPROVEMENT TO WIDESPREAD MVFR LATE TOMORROW MORNING IF THE CIGS
LIFT.
&&
.POINT TEMPS/POPS...
DLH 23 37 21 33 / 90 30 10 100
INL 19 38 17 37 / 60 20 0 90
BRD 24 38 24 37 / 50 10 50 100
HYR 20 38 20 41 / 80 40 10 100
ASX 24 37 17 39 / 90 60 0 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MNZ025-033>036.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ010-011-018-019-026-037.
WINTER STORM WARNING UNTIL 10 PM CDT THIS EVENING FOR MNZ012-020-
021.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ012-020-021.
WI...WINTER WEATHER ADVISORY UNTIL 7 AM CDT SATURDAY FOR WIZ003-004.
WINTER STORM WARNING UNTIL 7 AM CDT SATURDAY FOR WIZ002.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-147-148.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT SATURDAY FOR LSZ142>146.
SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ140-141.
&&
$$
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
734 AM CDT THU APR 11 2013
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY MORNING)
ISSUED AT 415 AM CDT THU APR 11 2013
WELL ADVERTISED PRECIPITATION BURST FINALLY STARTING TO COME
TOGETHER THIS MORNING ACROSS SRN MN. WATER VAPOR IMAGERY SHOWS MID
LEVEL DRY SLOT MOVING ACROSS IA AND INTO SW WI WITH A BAROCLINIC
LEAF WITH COOLING IR TEMPS STARTING TO OVERTAKE SRN MN. AT 3 AM SFC
FREEZING ALONG WITH SNOW LINE STRETCHED FROM NEW ULM UP INTO ST.
CLOUD. BESIDE SFC TEMPS BEING ABOVE FREEZING EAST OF ULM/STC...RAP
SOUNDINGS STILL SHOW A MELTING LAYER EXISTING BETWEEN H8-H7...HENCE
THE RAPL MIX SEEN OFF AND ON THROUGH THE EVENING HERE IN CHANHASSEN
AND OBSERVED AT MSP. HOWEVER...AS PRECIP INTENSITY CONTINUES TO
INCREASE THIS MORNING EXPECT THE SNOW LINE TO WORK EAST TO NEAR A
MANKATO/HASTINGS/RICE LAKE LINE AROUND DAYBREAK. THIS ERN SHIFT WILL
OCCUR FOR TWO REASONS. ONE...THOUGH AIR TEMPS MAY BE IN THE MID
30S...DEWPOINTS ARE ABOUT 10 DEGREES COOLER...SO WET BULBING EFFECTS
SHOULD START TO QUICKLY TAKE OVER THIS MORNING AND QUICKLY COOL SFC
TEMPS BELOW FREEZING ACROSS ALMOST THE ENTIRE AREA. FOR THE WARM
NOSE...IT WILL BE BEATEN BACK TO THE EAST AS STRONG LIFT IN THE
H8-H7 LAYER CAUSES IT TO COOL BACK BELOW FREEZING.
SO FAR THIS MORNING...THE SIOUX FALLS AREA PICKED UP 4-5 INCHES OF
SNOW...AND THAT WAS AS THIS BAND WAS JUST STARTING TO PICK UP IN
INTENSITY...SO STILL LOOKS GOOD TO SEE SOME RATHER RAPID AND
SIGNIFICANT SNOW ACCUMULATIONS NOW THROUGH ABOUT NOON. EXACTLY HOW
THAT WARM NOSE BREAKS DOWN IS WHAT WILL PLAY A LARGE ROLL IN HOW
MUCH SNOW IS SEEN THIS MORNING. SPREAD FOR WHERE THE SNOW LINE ENDS
UP THIS MORNING STILL SITS ANYWHERE FROM NEW ULM UP THROUGH MORA ON
THE RAP TO ALBERT LEA UP THROUGH LADYSMITH ON THE GEM...SO DESPITE
THE MAIN EVENT STARTING TO COMMENCE...A FAIR AMOUNT OF UNCERTAINTY
STILL EXISTS AS TO HOW MUCH SNOW THE TWIN CITIES GETS THIS MORNING.
THE RAP WOULD SAY 1 TO 3 INCHES AT BEST...WHILE THE GEM SOLUTION FOR
WHERE THE SNOW LINE ENDS UP WOULD PUT THE TWIN CITIES IN LINE FOR
DOUBLE DIGIT AMOUNTS. FOR THIS FORECAST FAVORED SOMETHING IN BETWEEN
WITH THE SNOW LINE MAKING IT TO NEAR THE MANKATO/HASTINGS/RICE LAKE
LINE MENTIONED EARLIER.
ALL MODELS SHOW THIS BAND QUICKLY LIFTING NORTH THOUGH THE MORNING
WITH IT MOSTLY NORTH OF THE MPX CWA BY 18Z. WHAT HAPPENS IN THE WAKE
OF THE HEAVY BAND IS STILL VERY DEBATABLE AT THE MOMENT. BASED ON
SOUNDINGS...CURRENT THINKING AS THAT MUCH OF THE AREA WILL LOSE ICE
IN THE CLOUDS...WITH DZ/FZDZ TAKING OVER FOR MUCH OF THE AFTERNOON
OUTSIDE OF WRN MN. ALREADY SEEING THIS ACROSS WRN IA...WHERE SEVERAL
SITES SOUTH OF THE COLD CLOUD TOPS NOW REPORTING DZ. TRIED TO
INCORPORATE THIS INTO THE GRIDS AS BEST AS POSSIBLE...BUT THIS WILL
NEED TO BE REFINED DURING THE MORNING.
FOR TONIGHT...AS THE UPPER LOW SLOWLY MOVES EAST ACROSS IA...WILL
SEE MID LEVEL MOISTURE FILL BACK IN FROM WEST TO EAST. FOLLOWED THE
IDEA OF THE 00Z NAM...WITH SNOW QUICKLY RETURNING TO MN BETWEEN 21Z
AND 00Z...WITH WI TRANSITION BACK TO SNOW BETWEEN 00Z AND 03Z AND
ICE GETS REINTRODUCED INTO THE CLOUDS. AFTER THAT...WILL BE IN MOIST
CYCLONIC FLOW THROUGH THE NIGHT...WITH PERIODS OF LIGHT SNOW
CONTINUING. HEAVIEST AMOUNTS TONIGHT ARE EXPECTED ACROSS WI...BUT
EVEN THERE...ONLY ANTICIPATING AN EXTRA 1-2 INCHES OF SNOW AS LIFT
AND DYNAMICS WILL BE CONSIDERABLY WEAKER THAN WHAT IS CURRENTLY
UNFOLDING.
AS FOR THE HEADLINES...SEE NO NEED FOR CHANGES...WITH GREATER THAN 6
INCHES OF SNOW STILL EXPECTED WEST OF A MANKATO/HASTINGS/RICE LAKE
LINE...WITH THE COMBINATION OF FZRA/IP/SN EAST OF THERE SUPPORTING
THE WARNING ACROSS EASTERN AREAS.
.LONG TERM...(FRIDAY MORNING THROUGH WEDNESDAY)
ISSUED AT 415 AM CDT THU APR 11 2013
CONTINUED COOL AND RATHER WET PATTERN INTO END OF PERIOD. CURRENT
SURFACE AND 50H LOW PRESSURE SYSTEM BECOMES ALMOST VERTICALLY
STACKED BY EARLY FRIDAY MORNING. ENERGY WRAPPING AROUND MID LEVEL
LOW AND COLD POOL ASSOCIATED WITH SAME JUSTIFIED FAIRLY HIGH POPS
OVER EASTERN THIRD OF CWA FRIDAY MORNING INTO THE AFTERNOON.
1000-500MB THICKNESS VALUES ASSURING ALL ACTIVITY WILL FALL AS
LIGHT SNOW. 50H LOW WILL MAKE A VERY SLOW EXIT INTO NORTHERN GREAT
LAKES REGION BY SATURDAY MORNING. ANY LINGERING SLT POPS OVER
WEST CENTRAL WI WILL END AS THIS OCCURS.
VERY SHORT DRY WINDOW OPENS UP OVER MUCH OF FA FOR MUCH OF MORNING
AND ALL OF THE AFTN HOURS. ZONAL FLOW REESTABLISHES ITSELF OVER
WESTERN HALF OF NORTHERN CONUS. THIS WILL USHER IN NEXT MID PACIFIC
STORM SYSTEM CURRENTLY SITUATED OVER GULF OF ALASKA. WARM FRONTAL
BOUNDARY ASSOCIATED WITH THIS SYSTEM WILL BEGIN TO AFFECT SW CWA
SATURDAY EVENING AND THEN OVERSPREAD ALL COUNTIES BY SUNDAY MORNING.
COULD BE A SHORT BOUT OF FREEZING RAIN OR DRIZZLE LATE SATURDAY NIGHT
OVER PORTION OF SW CWA ROUGHLY SW OF LINE FROM MORRIS TO BLUE EARTH.
CHANGEOVER TO ALL RAIN THIS REGION SHOULD OCCUR FAIRLY SOON AFTER
11 OR 12Z TIME FRAME. 850MB TEMPS TRANSITIONS SNOW OR A RAIN SNOW
MIX ACROSS REMAINDER OF CWA BY SATURDAY 18Z. SURFACE LOW PRESSURE
ASSOCIATED WITH THIS STORM SYSTEM WILL BE MUCH DEEPER (995MB)
...COMPARED TO CURRENT ONE...BUT UNFORTUNATELY ANOTHER SLOW MOVING
50H LOW WILL FORM WITH IT AND BOTH BECOME STACKED BY 15/06Z TIME
FRAME. TRACK INTO NORTHERN GREAT LAKES REGION WILL OCCUR BY
MONDAY EVENING.
DEEP MID LEVEL TROUGH BEGINS TO DIG OVER WESTERN CONUS BY TUESDAY
AFTN. BY WED AFTN 50H TROF WILL BE OBSERVED FROM NE NEW MEXICO
TO NW MN BY WED AFTN. PROGRESSION OF THIS TROF SLOWLY EASTWARD
GENERATES CHANCE PCPN ON BOTH WED AND THURSDAY. ATMOSPHERE STILL
LOOKS COLD ENOUGH TO INCLUDE EITHER A RAIN/SNOW MIX OR LIGHT SNOW
OVER MUCH OF FA BOTH DAYS.
INTO NEXT WEEKEND EXPECT ZONAL NORTHERN U.S. FLOW TO CONTINUE
UPSTREAM OF OUR LOCATION WITH ANOTHER MID PACIFIC STORM SYSTEM
BRINGING ANOTHER CHANCE FOR PCPN TO THE UPPER MIDWEST FRIDAY NIGHT
INTO SATURDAY. TEMPERATURES WILL CONTINUE THEIR PERSISTENT TREND
OF REMAINING ABOUT 10 DEGREES BELOW NORMAL INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 734 AM CDT THU APR 11 2013
HEAVY SNOW WELL UNDERWAY ACROSS MN...BUT BACK EDGE OF HEAVY PRECIP
ALREADY WORKING NORTH OUT OF SW/SC MN. HAVE THIS BACK EDGE OF SUB
1SM SNOW TIMED TO CLEAR RWF BY 13Z...MSP AROUND 14Z AND STC/AXN
BETWEEN 15Z AND 16Z. FOR WI...WITH DRY SLOT HEADING FOR CENTRAL
WI...RATES/AMOUNTS WILL BE LESS THERE...WITH EAU LIKELY TO SEE A
MAINLY RA/PL MIX WITH LIMITED SNOW. CONFIDENCE DOES DECREASE IN
PRECIP/VIS FORECAST AFTER THIS MORNINGS PRECIP BURST MOVES NORTH
OF THE AREA. INDICATIONS FROM THE NAM/RAP ARE THAT WE LOOSE ICE IN
THE CLOUDS EAST OF RWF/AXN...WITH PRIMARILY DZ EXPECTED THIS
AFTERNOON ACROSS ERN MN INTO WRN WI. VIS RESTRICTIONS MAY ALSO NOT
BE AS BAD AS CURRENTLY INDICATED...WITH PRECIP POSSIBLY JUST
CUTTING OF ALL TOGETHER THIS AFTERNOON...BUT CIGS LOOK TO REMAIN
FIRMLY IN THE IFR RANGE AS TERMINALS REMAIN JUST NORTH OF AN
INVERTED THROUGH. TONIGHT...AS DRY SLOT PUSHES EAST...DEEP
MOISTURE RETURNS...WITH ANY REMAINING PRECIP EXPECTED TO GO BACK
TO SNOW. BEST CHANCE FOR MORE PERSISTENT SNOWS OVERNIGHT WILL
SHIFT TO WRN WI. FINALLY...WINDS HAVE BEEN BEHAVING A BIT
UNEXPECTEDLY THIS MORNING...WITH HEAVY SNOW APPEARING TO
SIGNIFICANTLY DAMPEN WIND SPEEDS...THOUGH DO EXPECT THEM TO PICK
BACK UP FROM WHERE THEY LEFT OFF ONCE HEAVY SNOW MOVES OUT.
KMSP...STRONG SHORT TERM MODEL AGREEMENT WITH CURRENT BOUT OF
HEAVY SNOW QUICKLY SHUTTING OFF AROUND 14Z. CONFIDENCE DOES
DECREASE CONSIDERABLY IN PRECIP FORECAST AFTER ABOUT 15Z AS
MOISTURE IN THE SNOW GROWTH ZONE DEPARTS. SEE ONE OF TWO THINGS
HAPPENING. ONE...PRECIP ENDS WITH HEAVY SNOW...WITH NOTHING MORE
THAN FEW PASSING SPRINKLES. TWO...DZ OR A DZSN COMBO TAKES OVER
FOR THE REST OF THE AFTERNOON. OPTION ONE WOULD RESULT IN MAINLY
VFR VIS...WITH OPTION 2 KEEPING MAINLY MVFR VSBYS GOING. NO MATTER
WHAT HAPPENS WITH PRECIP...HARD PRESSED TO SEE CIGS LEAVING THE
IFR CATEGORY UNTIL FRIDAY MORNING. FOR WINDS...EXPECT THE NE WINDS
TO PICK BACK UP IN STRENGTH AS SNOW DIMINISHES...WITH A GRADUAL
BACKING OF WINDS TOWARD THE NW LATE TONIGHT.
/OUTLOOK FOR KMSP/
FRI...MVFR CIGS. -SN ENDING IN MORNING. WINDS NW 10 KTS.
SAT...MAINLY VFR...WITH MVFR CONDS OVERNIGHT. POSSIBLE -RA/-SN
OVERNIGHT. WINDS S AROUND 5 KT.
SUN...MVFR EXPECTED WITH IFR POSSIBLE...MAINLY IN THE MORNING.
MORNING -RA/-SN THEN AFTERNOON -RA. SE WINDS AROUND 10
KT...BECOMING S.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ041>045-
047>070-073>078-082>085-091>093.
WI...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...AZ
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
415 AM CDT THU APR 11 2013
.SHORT TERM...(TODAY THROUGH THURSDAY MORNING)
WELL ADVERTISED PRECIPITATION BURST FINALLY STARTING TO COME
TOGETHER THIS MORNING ACROSS SRN MN. WATER VAPOR IMAGERY SHOWS MID
LEVEL DRY SLOT MOVING ACROSS IA AND INTO SW WI WITH A BAROCLINIC
LEAF WITH COOLING IR TEMPS STARTING TO OVERTAKE SRN MN. AT 3 AM SFC
FREEZING ALONG WITH SNOW LINE STRETCHED FROM NEW ULM UP INTO ST.
CLOUD. BESIDE SFC TEMPS BEING ABOVE FREEZING EAST OF ULM/STC...RAP
SOUNDINGS STILL SHOW A MELTING LAYER EXISTING BETWEEN H8-H7...HENCE
THE RAPL MIX SEEN OFF AND ON THROUGH THE EVENING HERE IN CHANHASSEN
AND OBSERVED AT MSP. HOWEVER...AS PRECIP INTENSITY CONTINUES TO
INCREASE THIS MORNING EXPECT THE SNOW LINE TO WORK EAST TO NEAR A
MANKATO/HASTINGS/RICE LAKE LINE AROUND DAYBREAK. THIS ERN SHIFT WILL
OCCUR FOR TWO REASONS. ONE...THOUGH AIR TEMPS MAY BE IN THE MID
30S...DEWPOINTS ARE ABOUT 10 DEGREES COOLER...SO WET BULBING EFFECTS
SHOULD START TO QUICKLY TAKE OVER THIS MORNING AND QUICKLY COOL SFC
TEMPS BELOW FREEZING ACROSS ALMOST THE ENTIRE AREA. FOR THE WARM
NOSE...IT WILL BE BEATEN BACK TO THE EAST AS STRONG LIFT IN THE
H8-H7 LAYER CAUSES IT TO COOL BACK BELOW FREEZING.
SO FAR THIS MORNING...THE SIOUX FALLS AREA PICKED UP 4-5 INCHES OF
SNOW...AND THAT WAS AS THIS BAND WAS JUST STARTING TO PICK UP IN
INTENSITY...SO STILL LOOKS GOOD TO SEE SOME RATHER RAPID AND
SIGNIFICANT SNOW ACCUMULATIONS NOW THROUGH ABOUT NOON. EXACTLY HOW
THAT WARM NOSE BREAKS DOWN IS WHAT WILL PLAY A LARGE ROLL IN HOW
MUCH SNOW IS SEEN THIS MORNING. SPREAD FOR WHERE THE SNOW LINE ENDS
UP THIS MORNING STILL SITS ANYWHERE FROM NEW ULM UP THROUGH MORA ON
THE RAP TO ALBERT LEA UP THROUGH LADYSMITH ON THE GEM...SO DESPITE
THE MAIN EVENT STARTING TO COMMENCE...A FAIR AMOUNT OF UNCERTAINTY
STILL EXISTS AS TO HOW MUCH SNOW THE TWIN CITIES GETS THIS MORNING.
THE RAP WOULD SAY 1 TO 3 INCHES AT BEST...WHILE THE GEM SOLUTION FOR
WHERE THE SNOW LINE ENDS UP WOULD PUT THE TWIN CITIES IN LINE FOR
DOUBLE DIGIT AMOUNTS. FOR THIS FORECAST FAVORED SOMETHING IN BETWEEN
WITH THE SNOW LINE MAKING IT TO NEAR THE MANKATO/HASTINGS/RICE LAKE
LINE MENTIONED EARLIER.
ALL MODELS SHOW THIS BAND QUICKLY LIFTING NORTH THOUGH THE MORNING
WITH IT MOSTLY NORTH OF THE MPX CWA BY 18Z. WHAT HAPPENS IN THE WAKE
OF THE HEAVY BAND IS STILL VERY DEBATABLE AT THE MOMENT. BASED ON
SOUNDINGS...CURRENT THINKING AS THAT MUCH OF THE AREA WILL LOSE ICE
IN THE CLOUDS...WITH DZ/FZDZ TAKING OVER FOR MUCH OF THE AFTERNOON
OUTSIDE OF WRN MN. ALREADY SEEING THIS ACROSS WRN IA...WHERE SEVERAL
SITES SOUTH OF THE COLD CLOUD TOPS NOW REPORTING DZ. TRIED TO
INCORPORATE THIS INTO THE GRIDS AS BEST AS POSSIBLE...BUT THIS WILL
NEED TO BE REFINED DURING THE MORNING.
FOR TONIGHT...AS THE UPPER LOW SLOWLY MOVES EAST ACROSS IA...WILL
SEE MID LEVEL MOISTURE FILL BACK IN FROM WEST TO EAST. FOLLOWED THE
IDEA OF THE 00Z NAM...WITH SNOW QUICKLY RETURNING TO MN BETWEEN 21Z
AND 00Z...WITH WI TRANSITION BACK TO SNOW BETWEEN 00Z AND 03Z AND
ICE GETS REINTRODUCED INTO THE CLOUDS. AFTER THAT...WILL BE IN MOIST
CYCLONIC FLOW THROUGH THE NIGHT...WITH PERIODS OF LIGHT SNOW
CONTINUING. HEAVIEST AMOUNTS TONIGHT ARE EXPECTED ACROSS WI...BUT
EVEN THERE...ONLY ANTICIPATING AN EXTRA 1-2 INCHES OF SNOW AS LIFT
AND DYNAMICS WILL BE CONSIDERABLY WEAKER THAN WHAT IS CURRENTLY
UNFOLDING.
AS FOR THE HEADLINES...SEE NO NEED FOR CHANGES...WITH GREATER THAN 6
INCHES OF SNOW STILL EXPECTED WEST OF A MANKATO/HASTINGS/RICE LAKE
LINE...WITH THE COMBINATION OF FZRA/IP/SN EAST OF THERE SUPPORTING
THE WARNING ACROSS EASTERN AREAS.
.LONG TERM...(FRIDAY MORNING THROUGH WEDNESDAY)
CONTINUED COOL AND RATHER WET PATTERN INTO END OF PERIOD. CURRENT
SURFACE AND 50H LOW PRESSURE SYSTEM BECOMES ALMOST VERTICALLY
STACKED BY EARLY FRIDAY MORNING. ENERGY WRAPPING AROUND MID LEVEL
LOW AND COLD POOL ASSOCIATED WITH SAME JUSTIFIED FAIRLY HIGH POPS
OVER EASTERN THIRD OF CWA FRIDAY MORNING INTO THE AFTERNOON.
1000-500MB THICKNESS VALUES ASSURING ALL ACTIVITY WILL FALL AS
LIGHT SNOW. 50H LOW WILL MAKE A VERY SLOW EXIT INTO NORTHERN GREAT
LAKES REGION BY SATURDAY MORNING. ANY LINGERING SLT POPS OVER
WEST CENTRAL WI WILL END AS THIS OCCURS.
VERY SHORT DRY WINDOW OPENS UP OVER MUCH OF FA FOR MUCH OF MORNING
AND ALL OF THE AFTN HOURS. ZONAL FLOW REESTABLISHES ITSELF OVER
WESTERN HALF OF NORTHERN CONUS. THIS WILL USHER IN NEXT MID PACIFIC
STORM SYSTEM CURRENTLY SITUATED OVER GULF OF ALASKA. WARM FRONTAL
BOUNDARY ASSOCIATED WITH THIS SYTEM WILL BEGIN TO AFFECT SW CWA
SATURDAY EVENING AND THEN OVERSPREAD ALL COUNTIES BY SUNDAY MORNING.
COULD BE A SHORT BOUT OF FREEZING RAIN OR DRIZZLE LATE SATURDAY NIGHT
OVER PORTION OF SW CWA ROUGHLY SW OF LINE FROM MORRIS TO BLUE EARTH.
CHANGEOVER TO ALL RAIN THIS REGION SHOULD OCCUR FAIRLY SOON AFTER
11 OR 12Z TIME FRAME. 850MB TEMPS TRANSITIONS SNOW OR A RAIN SNOW
MIX ACROSS REMAINDER OF CWA BY SATURDAY 18Z. SURFACE LOW PRESSURE
ASSOCIATED WITH THIS STORM SYSTEM WILL BE MUCH DEEPER (995MB)
...COMPARED TO CURRENT ONE...BUT UNFORTUNATELY ANOTHER SLOW MOVING
50H LOW WILL FORM WITH IT AND BOTH BECOME STACKED BY 15/06Z TIME
FRAME. TRACK INTO NORTHERN GREAT LAKES REGION WILL OCCUR BY
MONDAY EVENING.
DEEP MID LEVEL TROUGH BEGINS TO DIG OVER WESTERN CONUS BY TUESDAY
AFTN. BY WED AFTN 50H TROF WILL BE OBSERVED FROM NE NEW MEXICO
TO NW MN BY WED AFTN. PROGRESSION OF THIS TROF SLOWLY EASTWARD
GENERATES CHANCE PCPN ON BOTH WED AND THURSDAY. ATMOSPHERE STILL
LOOKS COLD ENOUGH TO INCLUDE EITHER A RAIN/SNOW MIX OR LIGHT SNOW
OVER MUCH OF FA BOTH DAYS.
INTO NEXT WEEKEND EXPECT ZONAL NORTHERN U.S. FLOW TO CONTINUE
UPSTREAM OF OUR LOCATION WITH ANOTHER MID PACIFIC STORM SYSTEM
BRINGING ANOTHER CHANCE FOR PCPN TO THE UPPER MIDWEST FRIDAY NIGHT
INTO SATURDAY. TEMPERATURES WILL CONTINUE THEIR PERSISTENT TREND
OF REMAINING ABOUT 10 DEGREES BELOW NORMAL INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1201 AM CDT THU APR 11 2013
LITTLE CHANGE IN THINKING FROM 11/00Z TAFS EXCEPT FOR MAINLY
DURING THE FIRST FEW HOURS FROM 11/06Z ONWARD AS PRECIP HAS BEEN A
BIT SLOWER TO DEVELOP. HOWEVER...CURRENTLY KMPX RADAR SHOWS PLENTY
OF DEVELOPING AREAS OF PRECIPITATION...PREDOMINANTLY AS A WINTRY
MIX. THIS MIX WILL CONTINUE TO OVERSPREAD THE AREA AND CHANGE OVER
TO -SN BY 08Z-09Z. THE MAIN CONCERN THEN BECOMES PRECIP INTENSITY
AS SHORT-TERM MODELS STILL PIN DOWN THE 09Z-14Z TIMEFRAME WHEN
INTENSITY AND QPF WILL BE GREATEST. SOME SNOWFALL RATES MAY BE AS
HIGH AS 2-3 IN/HR FOR A BRIEF PERIOD AFTER SUNRISE SO HAVE HIT
THIS IN THE TAF WITH VSBY BETWEEN 1/2SM-1SM. PRECIP THEN LESSENS
IN INTENSITY LATE MRNG THRU THE AFTN...BUT DIFFICULT TO DISCERN
WHERE THERE MAY BE SOME DRY SLOTTING WHICH WOULD IMPROVE VSBY WITH
MUCH LIGHTER PRECIP. THEN...THERE WILL BE ANOTHER SURGE OF
MOISTURE AS THE SYSTEM EXITS WHICH MAY BRING A RETURN OF STRONGER
-SN ON THE BACKSIDE OF THE DEPARTING LOW PRES SYSTEM. CEILINGS
OVERALL TAKE A DIVE DOWN TO IFR AND REMAIN THERE THRU MUCH OF THE
DAY...THOUGH THERE MAY WELL BE OCNL PERIODS WHEN CIGS BOUNCE
UPWARDS INTO LOW-END MVFR. AS FOR THE WINDS...SPEEDS WILL
GENERALLY REACH 15G25KT THROUGH MUCH OF THE OVERNIGHT HOURS AND
THUR. DIRECTIONS WILL BE A BIT PROBLEMATIC...BUT PREVAILING
DIRECTIONS ON AVAILABLE MOS GUIDANCE IS IN THE 040-060 RANGE.
KMSP...TWO MAIN ISSUES WILL BE SNOWFALL INTENSITY ALONG WITH WIND
DIRECTIONS. PATCHY -RASN ARND MSP DURING THE EARLY MRNG HRS WILL
BECOME MORE WIDESPREAD AND CHANGE OVER TO -SN...APPROXIMATELY BY
11/08Z. SNOWFALL WILL THEN PICK UP IN INTENSITY THROUGH THE EARLY
MRNG HOURS...POSSIBLY HEAVY AT TIMES BETWEEN 09Z-13Z...RIGHT
THROUGH THE MRNG PUSH. VSBY MAY WELL DROP AS LOW AS 1/2SM BUT
CONFIDENCE IS HIGH IN SEEING VSBY LESS THAN 1SM. SNOWFALL THEN
LOOKS TO LESSEN IN INTENSITY BY LATE MRNG...GRADUALLY ALLOWING
VSBY TO RISE INTO MVFR RANGE. NEVERTHELESS...CEILINGS WILL BE
SOLIDLY IN IFR RANGE IF NOT LOWER FOR MUCH OF THE EVENT. AS FOR
WIND DIRECTIONS...AM HAVING A HARD TIME SEEING ANYTHING OTHER THAN
050-060 DIRECTION...WITH OCCASIONAL 040 BUT NOT LIKELY TO SEE 070.
FOR AROUND THE MORNING PUSH...WILL LOOK FOR PREDOMINANTLY 050.
SPEEDS WILL REMAIN ARND 15G25KT THROUGHOUT THIS TAF PERIOD.
/OUTLOOK FOR KMSP/
FRI...MVFR CIGS. -SN ENDING IN MORNING. WINDS NW 10 KTS.
SAT...MAINLY VFR...WITH MVFR CONDS OVERNIGHT. POSSIBLE -RA/-SN
OVERNIGHT. WINDS S AROUND 5 KT.
SUN...MVFR EXPECTED WITH IFR POSSIBLE...MAINLY IN THE MORNING.
MORNING -RA/-SN THEN AFTERNOON -RA. SE WINDS AROUND 10
KT...BECOMING S.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ041>045-
047>070-073>078-082>085-091>093.
WI...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...AZ
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1236 PM CDT THU APR 11 2013
.UPDATE...
ISSUED AT 1126 AM CDT THU APR 11 2013
CWFA WILL LIE UNDER CYCLONIC FLOW ALOFT WITH STRONG CAA PROGGED AT
850 HPA. KOAX HAD A TEMP OF -8C AT 1200 UTC THIS MORNING AND THE
850-HPA FRONT IS COMING THROUGH THE CENTER OF THE CWFA AS WE
SPEAK. WITH STRONG CAA AND MVFR CEILINGS CONTINUING THROUGH MID
AFTERNOON. THUS...HAVE LOWERED HI TEMPS AT LEAST A FEW DEGREES
AREAWIDE. IN ADDITION...HAVE ADDED PATCHY DRIZZLE FOR THE ENTIRE
CWA AND HAVE CUT CHC POPS BACK TO SCH POPS FOR ISOLATED SHOWERS
OVER NORTHEAST MISSOURI AND WEST-CENTRAL ILLINOIS. HESITANT TO
JUST GO WITH DRIZZLE/SPRINKLES OVER THIS REGION AND DROP
MEASURABLE POPS ALTOGETHER AS WV IMAGERY DOES HAVE A SHORTWAVE
UPSTREAM OVER NW MO AND LATEST HRRR GUIDANCE ALSO SUGGESTS
ISOLATED SHOWERS OVER THIS REGION UNDER THE COLD CORE 500-HPA
CYCLONE/STEEP MIDLEVEL LAPSE RATES ALOFT. ZONE UPDATE WILL BE OUT SHORTLY.
GOSSELIN
&&
.SHORT TERM...(THROUGH LATE THIS AFTERNOON)
ISSUED AT 350 AM CDT THU APR 11 2013
LIGHT RAIN/DRIZZLE THAT IS LINGERING OVER THE METRO AREA INTO
ILLINOIS IS SHOWING SLOW PROGRESSION EASTWARD EARLY THIS MORNING.
ANY LINGERING LIGHT RAIN WILL END THIS MORNING AS ASCENT WEAKENS
OVER THE AREA. WILL KEEP MENTION OF ISOLATED/SCATTERED LIGHT
SHOWERS ALONG AND NORTH OF I-70 THIS AFTERNOON WHERE LOW LEVEL
MOISTURE WILL LINGER IN CYCLONIC FLOW. TEMPERATURES WILL ONLY SHOW
A SLIGHT INCREASE TODAY WITH MAINLY CLOUDY SKIES AND COLD AIR
ADVECTION. ONLY TWEAKED GOING HIGHS WHICH MATCH UP WELL WITH MOS
HIGHS/MODEL 2 METER TEMPERATURES.
BRITT
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU APR 11 2013
UPPER LEVEL LOW AND ASSOCIATED SFC LOW OVER IA THIS EVNG WILL MOVE
NEWD INTO WI LATER TGT. IT APPEARS THAT MOST OF THE PRECIPITATION
IN THE WRAP AROUND MOISTURE WILL REMAIN N OF OUR FORECAST
AREA...ALTHOUGH THERE COULD BE A LITTLE LIGHT RAIN ACROSS NERN MO
AND W CNTRL IL...MAINLY THIS EVNG...POSSIBLY MIXED WITH A LITTLE
LIGHT SNOW LATE THIS EVNG. MUCH COLDER TEMPERATURES CAN BE
EXPECTED TGT WITH THE NAM AND ECMWF MODELS DROPPING THE -4 DEGREE
C ISOTHERM SEWD INTO SERN MO AND SWRN IL BY 12Z FRI...THE GFS
MODEL IS A LITTLE WARMER. LOWS TGT WILL LIKELY BE DOWN TO AROUND
THE FREEZING MARK ACROSS NERN AND CNTRL MO AS WELL AS W CNTRL IL.
BELOW NORMAL TEMPERATURES WILL CONINUE ON FRI WITH CLOUD COVER
CONTINUING ACROSS NERN MO AND W CNTRL IL INTO SWRN IL...BUT
PRECIPITATION REMAINING N-NE OF OUR AREA...MAINLY IN THE GREAT
LAKES REGION IN THE VICINITY OF THE UPPER/SFC LOW. A NW FLOW
SHORTWAVE WILL DROP SEWD THROUGH IA AND NRN IL FRI NGT BRINGING A
REINFORCING SHOT OF COLD AIR INTO NERN MO AND W CNTRL IL. WITH
POTENTIALLY LESS CLOUD COVER AND WEAKER SFC WINDS THE LOWS FRI NGT
WILL LIKELY BE LOWER THAN TGT...RANGING FROM THE UPPER 20S IN
NERN MO TO THE MID 30S IN SERN MO. WILL HOLD OFF ON ANY
FREEZE/FROST HEADLINES/PRODUCTS FOR NOW BUT LATER SHIFTS MAY NEED
TO ISSUE A FREEZE WARNING FOR PARTS OF OUR AREA TGT AND/OR FRI
NGT AS THE GROWING SEASON HAS BEGUN. A WARMING TREND WILL BEGIN
SAT AFTN AS THE SFC/LOW LEVEL WINDS BECOME S/SWLY BY 00Z SUN AS
THE SFC/850 MB RIDGE SHIFTS E-SE OF OUR AREA...AND THE UPPER LEVEL
HEIGHTS BEGIN TO RISE. THE PERSISTENT LOW LEVEL CLOUDS SHOULD ALSO
FINALLY ADVECT WELL NE OF OUR AREA BY SAT...ALTHOUGH IT APPEARS
THAT MID LEVEL...WAA CLOUDS WILL BE MOVING EWD INTO OUR AREA SAT
AFTN. STILL LOOKS LIKE THERE WILL BE THE POTENTIAL FOR ELEVATED
CONVECTION...MAINLY LATE SAT NGT AND MAINLY ACROSS NERN MO AND W
CNTRL IL...AS A STRENGTHENING SWLY LOW LEVEL JET BRINGS STRONG
LOW-MID LEVEL WAA TO THIS AREA ALONG WITH INCREASING LOW LEVEL
MOISTURE. THE CHANCE OF RAIN WILL CONTINUE ACROSS NERN MO AND W
CNTRL IL ON SUN AS AN UPPER LEVEL AND ASSOCIATED SFC LOW MOVE
NEWD THROUGH THE NRN PLAINS DRAGGING A COLD FRONT SLOWLY SEWD INTO
THE NWRN PORTION OF OUR FORECAST AREA. THIS FRONT SHOULD SAG SLOWLY
S-SEWD THROUGH OUR FORECAST AREA SUN NGT AND MON. THE GFS MODEL IS A
LITTLE MORE PROGESSIVE WITH THIS FRONT THAN THE ECMWF MODEL. IT
APPEARS THAT MOST OF THE PRECIPITATION WILL BE POST FRONTAL...BUT
WITH A LOT OF UNCERTAINTY WITH THE EXACT PLACEMENT OF THIS FRONT
WILL NEED TO BROADBRUSH CHANCE POPS ACROSS THE ENTIRE FORECAST
AREA MON NGT THROUGH TUE NGT. THE COOLEST TEMPERATURES SHOULD BE
ACROSS NERN MO WELL BEHIND THE COLD FRONT. THE BEST CHANCE OF RAIN
IS EXPECTED ON WED AND WED NGT AS A SFC LOW DEVELOPS ALONG THE
FRONT AS AN UPPER LEVEL TROUGH APPROACHES. THE ECMWF MODEL KEEPS
THE MAIN SFC LOW N OF OUR AREA MORE TYPICAL OF SPRING...WHILE THE
GFS MODEL IS FURTHER S WITH THE TRACK OF THE SFC LOW...KEEPING IT
JUST S OF OUR AREA AND IS A COLDER SOLUTION.
GKS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1224 PM CDT THU APR 11 2013
MAIN CONCERN FOR THE VALID TAF PERIOD IS CEILINGS. MVFR CEILINGS
WILL LIKELY HOLD STRONG INTO AT LEAST THE MID AFTERNOON HOURS AS
THE REGION IS UNDER PERSISTENT COLD/CYCLONIC FLOW ALOFT. WAS
PESSIMISTIC WITH TIMING OF CEILINGS CLIMBING ABOVE THE FUEL
ALTERNATE THRESHOLD OF 2000 FEET AS CEILINGS HAVE BEEN VERY
STUBBORN TO CLIMB THUS FAR TODAY. AM ALSO A BIT CONCERNED THAT
ONCE SUN GOES DOWN AND NOCTURNAL COOLING COMMENCES THAT CEILINGS
WILL HAVE A HARD TIME GETTING ABOVE MVFR...ESPECIALLY FOR THE
METRO TAFS AND QUINCY WHICH WILL BE IN CLOSER PROXIMITY TO
DEPARTING LOW PRESSURE SYSTEM. WINDS WILL STAY WESTERLY WITH SOME
GUSTS AROUND 20 KNOTS THIS AFTERNOON AND TOMORROW AS WELL.
SPECIFICS FOR KSTL...
MAIN CONCERN FOR THE VALID TAF PERIOD IS CEILINGS. MVFR CEILINGS
WILL LIKELY HOLD STRONG INTO AT LEAST THE MID AFTERNOON HOURS AS
THE REGION IS UNDER PERSISTENT COLD/CYCLONIC FLOW ALOFT. WAS
PESSIMISTIC WITH TIMING OF CEILINGS CLIMBING ABOVE THE FUEL
ALTERNATE THRESHOLD OF 2000 FEET AT LAMBERT AS CEILINGS HAVE BEEN
VERY STUBBORN TO CLIMB THUS FAR TODAY. AM ALSO A BIT CONCERNED
THAT ONCE SUN GOES DOWN AND NOCTURNAL COOLING COMMENCES THAT
CEILINGS WILL HAVE A HARD TIME GETTING ABOVE MVFR...BUT DUE TO LOW
CONFIDENCE IN THIS SCENARIO...HAVE ELECTED TO KEEP PREVIOUS
FORECAST GOINGN FOR NOW. WINDS WILL STAY WESTERLY WITH SOME GUSTS
AROUND 20 KNOTS THIS AFTERNOON BEFORE DIEING OFF THIS EVENING.
WINDS WILL INCREASE AND BECOME GUSTY AGAIN DURING THE DAY
TOMORROW.
GOSSELIN
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1135 AM CDT THU APR 11 2013
.UPDATE...
ISSUED AT 1126 AM CDT THU APR 11 2013
CWFA WILL LIE UNDER CYCLONIC FLOW ALOFT WITH STRONG CAA PROGGED AT
850 HPA. KOAX HAD A TEMP OF -8C AT 1200 UTC THIS MORNING AND THE
850-HPA FRONT IS COMING THROUGH THE CENTER OF THE CWFA AS WE
SPEAK. WITH STRONG CAA AND MVFR CEILINGS CONTINUING THROUGH MID
AFTERNOON. THUS...HAVE LOWERED HI TEMPS AT LEAST A FEW DEGREES
AREAWIDE. IN ADDITION...HAVE ADDED PATCHY DRIZZLE FOR THE ENTIRE
CWA AND HAVE CUT CHC POPS BACK TO SCH POPS FOR ISOLATED SHOWERS
OVER NORTHEAST MISSOURI AND WEST-CENTRAL ILLINOIS. HESITANT TO
JUST GO WITH DRIZZLE/SPRINKLES OVER THIS REGION AND DROP
MEASURABLE POPS ALTOGETHER AS WV IMAGERY DOES HAVE A SHORTWAVE
UPSTREAM OVER NW MO AND LATEST HRRR GUIDANCE ALSO SUGGESTS
ISOLATED SHOWERS OVER THIS REGION UNDER THE COLD CORE 500-HPA
CYCLONE/STEEP MIDLEVEL LAPSE RATES ALOFT. ZONE UPDATE WILL BE OUT SHORTLY.
GOSSELIN
&&
.SHORT TERM...(THROUGH LATE THIS AFTERNOON)
ISSUED AT 350 AM CDT THU APR 11 2013
LIGHT RAIN/DRIZZLE THAT IS LINGERING OVER THE METRO AREA INTO
ILLINOIS IS SHOWING SLOW PROGRESSION EASTWARD EARLY THIS MORNING.
ANY LINGERING LIGHT RAIN WILL END THIS MORNING AS ASCENT WEAKENS
OVER THE AREA. WILL KEEP MENTION OF ISOLATED/SCATTERED LIGHT
SHOWERS ALONG AND NORTH OF I-70 THIS AFTERNOON WHERE LOW LEVEL
MOISTURE WILL LINGER IN CYCLONIC FLOW. TEMPERATURES WILL ONLY SHOW
A SLIGHT INCREASE TODAY WITH MAINLY CLOUDY SKIES AND COLD AIR
ADVECTION. ONLY TWEAKED GOING HIGHS WHICH MATCH UP WELL WITH MOS
HIGHS/MODEL 2 METER TEMPERATURES.
BRITT
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU APR 11 2013
UPPER LEVEL LOW AND ASSOCIATED SFC LOW OVER IA THIS EVNG WILL MOVE
NEWD INTO WI LATER TGT. IT APPEARS THAT MOST OF THE PRECIPITATION
IN THE WRAP AROUND MOISTURE WILL REMAIN N OF OUR FORECAST
AREA...ALTHOUGH THERE COULD BE A LITTLE LIGHT RAIN ACROSS NERN MO
AND W CNTRL IL...MAINLY THIS EVNG...POSSIBLY MIXED WITH A LITTLE
LIGHT SNOW LATE THIS EVNG. MUCH COLDER TEMPERATURES CAN BE
EXPECTED TGT WITH THE NAM AND ECMWF MODELS DROPPING THE -4 DEGREE
C ISOTHERM SEWD INTO SERN MO AND SWRN IL BY 12Z FRI...THE GFS
MODEL IS A LITTLE WARMER. LOWS TGT WILL LIKELY BE DOWN TO AROUND
THE FREEZING MARK ACROSS NERN AND CNTRL MO AS WELL AS W CNTRL IL.
BELOW NORMAL TEMPERATURES WILL CONINUE ON FRI WITH CLOUD COVER
CONTINUING ACROSS NERN MO AND W CNTRL IL INTO SWRN IL...BUT
PRECIPITATION REMAINING N-NE OF OUR AREA...MAINLY IN THE GREAT
LAKES REGION IN THE VICINITY OF THE UPPER/SFC LOW. A NW FLOW
SHORTWAVE WILL DROP SEWD THROUGH IA AND NRN IL FRI NGT BRINGING A
REINFORCING SHOT OF COLD AIR INTO NERN MO AND W CNTRL IL. WITH
POTENTIALLY LESS CLOUD COVER AND WEAKER SFC WINDS THE LOWS FRI NGT
WILL LIKELY BE LOWER THAN TGT...RANGING FROM THE UPPER 20S IN
NERN MO TO THE MID 30S IN SERN MO. WILL HOLD OFF ON ANY
FREEZE/FROST HEADLINES/PRODUCTS FOR NOW BUT LATER SHIFTS MAY NEED
TO ISSUE A FREEZE WARNING FOR PARTS OF OUR AREA TGT AND/OR FRI
NGT AS THE GROWING SEASON HAS BEGUN. A WARMING TREND WILL BEGIN
SAT AFTN AS THE SFC/LOW LEVEL WINDS BECOME S/SWLY BY 00Z SUN AS
THE SFC/850 MB RIDGE SHIFTS E-SE OF OUR AREA...AND THE UPPER LEVEL
HEIGHTS BEGIN TO RISE. THE PERSISTENT LOW LEVEL CLOUDS SHOULD ALSO
FINALLY ADVECT WELL NE OF OUR AREA BY SAT...ALTHOUGH IT APPEARS
THAT MID LEVEL...WAA CLOUDS WILL BE MOVING EWD INTO OUR AREA SAT
AFTN. STILL LOOKS LIKE THERE WILL BE THE POTENTIAL FOR ELEVATED
CONVECTION...MAINLY LATE SAT NGT AND MAINLY ACROSS NERN MO AND W
CNTRL IL...AS A STRENGTHENING SWLY LOW LEVEL JET BRINGS STRONG
LOW-MID LEVEL WAA TO THIS AREA ALONG WITH INCREASING LOW LEVEL
MOISTURE. THE CHANCE OF RAIN WILL CONTINUE ACROSS NERN MO AND W
CNTRL IL ON SUN AS AN UPPER LEVEL AND ASSOCIATED SFC LOW MOVE
NEWD THROUGH THE NRN PLAINS DRAGGING A COLD FRONT SLOWLY SEWD INTO
THE NWRN PORTION OF OUR FORECAST AREA. THIS FRONT SHOULD SAG SLOWLY
S-SEWD THROUGH OUR FORECAST AREA SUN NGT AND MON. THE GFS MODEL IS A
LITTLE MORE PROGESSIVE WITH THIS FRONT THAN THE ECMWF MODEL. IT
APPEARS THAT MOST OF THE PRECIPITATION WILL BE POST FRONTAL...BUT
WITH A LOT OF UNCERTAINTY WITH THE EXACT PLACEMENT OF THIS FRONT
WILL NEED TO BROADBRUSH CHANCE POPS ACROSS THE ENTIRE FORECAST
AREA MON NGT THROUGH TUE NGT. THE COOLEST TEMPERATURES SHOULD BE
ACROSS NERN MO WELL BEHIND THE COLD FRONT. THE BEST CHANCE OF RAIN
IS EXPECTED ON WED AND WED NGT AS A SFC LOW DEVELOPS ALONG THE
FRONT AS AN UPPER LEVEL TROUGH APPROACHES. THE ECMWF MODEL KEEPS
THE MAIN SFC LOW N OF OUR AREA MORE TYPICAL OF SPRING...WHILE THE
GFS MODEL IS FURTHER S WITH THE TRACK OF THE SFC LOW...KEEPING IT
JUST S OF OUR AREA AND IS A COLDER SOLUTION.
GKS
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 627 AM CDT THU APR 11 2013
CEILINGS ARE IFR/LOW MVFR ACROSS THE REGION THIS MORNING. EXPECT A
SLOW INCREASE IN CEILINGS THROUGH THE DAY BEFORE BECOMING VFR BY
THIS AFTERNOON. WESTERLY WINDS WILL BE IN THE 10-14KT RANGE WITH
SOME GUSTS TO AROUND 20KTS. THERE WILL BE SCATTERED -SHRA MOVE
ACROSS NORTHEAST MO/WEST CENTRAL ILLINOIS THIS AFTERNOON...BUT
COVERAGE WILL NOT BE ENOUGH TO INCLUDE IN THE KUIN AT THIS TIME.
SPECIFICS FOR KSTL...CEILINGS WILL BE IN THE 800-1200FT RANGE
THROUGH 15Z BEFORE SLOWLY INCREASING THROUGH THE DAY. WESTERLY
WINDS WILL BE IN THE 10-14KT RANGE WITH SOME GUSTS TO AROUND
20KTS.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1143 PM CDT Wed Apr 10 2013
...Updated for Aviation...
.UPDATE...
Issued at 900 PM CDT WED APR 10 2013
Widespread rains have shifted east of the CWA this evening, therefore
have cancelled flood watch. Weak shortwave energy rotating around the
trough will continue to produce a band of showers and moderate
drizzle as it pivots into the region. HRRR guidance seems to capture
ongoing trends well, with this band of showers pivoting into northern
Missouri and eventually Iowa by Midnight.
Otherwise remaining forecast remains on track as temperatures slowly
cool through the 30s overnight.
&&
.SHORT TERM...(This Evening through Thursday)
Issued at 408 PM CDT WED APR 10 2013
Late This Afternoon through Thursday:
Can finally see the light at the end of the tunnel with respect to
the moderate rain and embedded convection. Latest satellite imagery
and radar data show a firm back edge to the post-frontal rain from
east-central KS through eastern OK. The entire region is lifting
northeastward at a fairly quick pace. The latest RAP mass fields/QPF
have the best handle on this and have sped up the ending time of the
rain over the CWA for this evening. While the moisture above h7 will
be stripped away by a pronounced dry slot, and thus putting an end
to the widespread rain, there will be relatively deep and nearly
saturated layer up through at least h8 so can`t rule out the
occasional sprinkle once the main rain band moves through.
The upper low and associated deep/positively tilted trough from the
Central High Plains through the Southern Rockies will continue to
influence our sensible weather through tomorrow. This feature is
expected to shift east while the low deepens over eastern NE/western
IA and the trough axis takes on a more neutral tilt. Am expecting
considerable low level moisture to remain trapped over the region
and provide a blanket of clouds through tomorrow. There will likely
be at least one mid level vorticity maxima that will rotate under the
primary upper low and track across eastern KS and northern MO on
Thursday. This feature could produce patches of light rain over much
of the CWA. However, the rain may be only enough to wet the pavement
south of Highway 36. North of this line will go with chance PoPs.
Will also need to consider some light snow over the northwest corner
of MO in the morning as progged soundings forecast just enough ice
crystals to support this threat.
As for temperatures will favor the consensus approach for overnight
lows while going under NAM/GFS MOS guidance due to the extensive
cloud cover and unseasonably cold airmass.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 408 PM CDT WED APR 10 2013
Thursday night through Wednesday...
The shortwave trough will gradually depart the region Thursday night
into Friday with cool temperatures remaining. Minimum temperatures
may drop to or a few degrees below freezing both Friday and Saturday
mornings, so those with agricultural interest or sensitive
vegetation concerns should closely monitor subsequent forecasts.
Otherwise, upper level ridging builds into the central portion of
the CONUS Saturday and Sunday, with southerly surface winds
returning. This will spell a notable warmup Saturday and especially
on Sunday, with maximum readings on Sunday reaching the 70s in many
locations. A shortwave trough will eject northeastward out of the
Northern Plains on Sunday with an associated cold front approaching
the CWA on Sunday. The forward progression of the front will be
hindered as the upper system moves quickly away from the area. This
frontal boundary will linger across or near the CWA Sunday afternoon
as the next shortwave trough enters the plains and follows a similar
track. With little overall change to the upper air pattern and the
close proximity of the surface boundary, the potential for
precipitation will exist across portions of the area each day Sunday
through Wednesday. Temperatures will be closely tied to the position
of the front, with the warmest readings residing across the southern
portions of the CWA.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1136 PM CDT WED APR 10 2013
Ceilings continue to bounce between MVFR/IFR for much of the evening
hours and this variability may continue through the remainder of the
overnight hours. Visibilities will be even more variable but should
remain between 3 and 6SM through daybreak...with very brief drops to
2SM or less.
For Thursday, conditions will slowly improve through the morning,
with ceilings lifting back toward VFR levels by mid afternoon. There
could be a few sprinkles or light showers along and north of Hwy 36
in the afternoon, but confidence too low to include in 06z TAFs.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...Dux
SHORT TERM...MJ
LONG TERM...Blair
AVIATION...Dux
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
845 PM EDT FRI APR 12 2013
.SYNOPSIS...
A LOW PRESSURE AREA WILL PASS SOUTH OF NEW ENGLAND OVERNIGHT.
AN UPPER LOW OVER THE GREAT LAKES WILL BRING A CHANCE OF RAIN AND
SNOW SHOWERS TO THE NORTH COUNTRY SATURDAY AND SUNDAY. A RIDGE OF
HIGH PRESSURE WILL BUILD INTO THE NORTH COUNTRY SUNDAY NIGHT AND MONDAY
WITH FAIR AND DRY WEATHER EXPECTED.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
AS OF 839 PM EDT FRIDAY...STILL DEALING WITH SOME ICING
ISSUES...GENERALLY ALONG/EAST OF THE GREEN MTNS FROM I-89
NORTHWARD TO THE CANADIAN BORDER WITH AREAS OF IP/FZRA/SHSN. THE
00Z OBSERVATIONS INDICATE TEMPS 31F AT MPV AND 32F AT 1V4. UP AT
2200FT...WALDEN VT REMAINS 27F. STILL SOME BROAD ISENTROPIC
UPGLIDE OCCURRING FROM SW-NE ACROSS THE FORECAST AREA THIS
EVENING. ASSOCIATED LIGHT SHOWERY PRECIPITATION EXTENDS AT 00Z
FROM THE CHAMPLAIN VALLEY NEWD ACROSS N-CENTRAL NERN VT. GENERALLY
LOOKING FOR MID-LEVEL DRYING NEXT FEW HOURS...WHICH WILL ALLOW THE
INTERMITTENT IP/FZRA TO END. ALSO... RAP SOUNDINGS SHOW GENERAL
COOLING OF VERTICAL TEMPERATURE PROFILE OVERNIGHT...WITH ABOVE
FREEZING LAYER DISSIPATING AROUND 05Z. FROM THAT POINT
ONWARD...ANTICIPATE ANY LINGERING SHOWERY PRECIPITATION ACROSS
N-CENTRAL/NERN VT WILL FALL AS SNOW SHOWERS OR FLURRIES WITH A
LIGHT COATING POSSIBLE IN SPOTS. THE WINTER WEATHER ADVISORY HAS
BEEN ALLOWED TO EXPIRE ON TIME...BUT HAZARDOUS WEATHER OUTLOOK HAS
BEEN REWORDED TO EMPHASIZE PROSPECT FOR LOCALIZED ICY SPOTS
LINGERING ON UNTREATED SECONDARY AND DIRT ROADS OVERNIGHT
CENTRAL/ERN VT...ESPECIALLY AT ELEVATIONS ABOVE 1000 FEET.
TRAVELERS OVERNIGHT IN N-CENTRAL/NERN VT SHOULD CONTINUE TO
EXERCISE CAUTION WITH NEAR STEADY TEMPS AROUND FREEZING EVEN AS
THE FREEZING PRECIPITATION ENDS.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 451 PM EDT FRIDAY...A CLOSED UPPER LOW OVER THE GREAT LAKES
EARLY SATURDAY WILL DRIFT SLOWLY EAST THROUGH SUNDAY. THIS UPPER
LOW WILL KEEP TEMPERATURES BELOW NORMAL SATURDAY AND
SUNDAY...ALONG WITH BRINGING A CHANCE OF RAIN AND SNOW SHOWERS TO
THE NORTH COUNTRY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE
REGION SUNDAY NIGHT WITH FAIR AND DRY WEATHER EXPECTED.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...THE BATTLE OF SPRING VS WINTER WL CONT
ACRS THE NE CONUS FOR THE EXTENDED...WITH LATEST MODEL TRENDS
INDICATING SOME SPRINGLIKE WX IS POSSIBLE. BOTH GFS/ECMWF SHOW
DEVELOPMENT OF MID/UPPER LVL RIDGE ACRS THE SE CONUS FOR NEXT
WEEK...WHILE SFC LOW PRES TRACKS TO OUR WEST...PLACING OUR CWA IN
THE WARM SECTOR. HOWEVER...THIS PATTERN WAS ALSO SUPPOSE TO HAPPEN
TODAY...INSTEAD THE LOW TRACKED TO OUR SOUTH...AND A SHARP THERMAL
GRADIENT WAS PRESENT WITH MIXED PRECIP. IN ADDITION...MODELS CONT
TO SHOW A STRONG SFC HIGH PRES LOCATED NEAR HUDSON BAY NEXT
WEEK AND THE ANTICYCLONIC FLW AROUND THIS SYSTEM MAY SUPPRESS THE
WARM UP. ITS ALWAYS VERY DIFFICULT TO DETERMINE EXACT POSITION OF
BOUNDARY IN THE DAY 4 THRU 7 PERIOD...ESPECIALLY GIVEN TIGHT
THERMAL GRADIENT. GIVEN THE UNCERTAINTY WL KEEP TEMPS CLOSE TO
SEASONAL NORMALS...BUT COULD EASILY SEE TEMPS WELL INTO THE
60S/L70S IF THE ECMWF PROGGED 85H TEMPS BTWN 10 AND 12C VERIFY ON
THURSDAY. GIVEN POSITION OF SFC BOUNDARY AND EMBEDDED
VORTS/ENHANCED MOISTURE WL KEEP FA UNSETTLED DURING THE EXTENDED
PERIOD. DIFFICULT TO DETERMINE EXACT TIMING OF SYSTEMS WITH FAST
FLW ALOFT. WL KEEP MENTION OF CHC POPS ON TUES...THEN AGAIN THURS
INTO FRIDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...SCATTERED RAIN WITH MTN RAIN/SNOW SHOWERS
THRU 02-03Z...THEN SOME DRY SLOT CONDS BEFORE A FEW MORE
SHORTWAVES DELIVER CHCS PRIOR TO DAYBREAK AND THEN SAT AFTN.
LIGHTER WNDS WILL LIKELY MEAN MVFR FOR MANY LOCALES DUE TO CIGS
AND SOME IFR CONDS PSBL AT KSLK. KMSS LIFR AT 00Z WILL LIKELY
IMPROVE TO MVFR/IFR AS WINDS SHIFT SW BY 03-04Z.
VFR-MVFR FOR SATURDAY WITH SOME ISOLD IFR PSBL WITH AFTN SHOWERS
FOR KSLK. WINDS WILL BE < 10 KTS.
OUTLOOK 00Z SUNDAY THROUGH TUESDAY...
00Z SUNDAY THROUGH 00Z MONDAY...CONTINUED UNSETTLED CONDITIONS
WITH A MIX OF MVFR/VFR LIKELY AS AN UPPER LOW OVER CANADA PRODUCES
SCATTERED RAIN AND SNOW SHOWERS...WITH SNOW SHOWERS MAINLY OVER
THE HIGHER ELEVATIONS OF THE ADIRONDACKS AND GREEN MOUNTAINS.
00Z MONDAY THROUGH 00Z TUESDAY...VFR CONDITIONS EXPECTED AS A
RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION.
00Z TUESDAY THROUGH 00Z WEDNESDAY...MVFR/IFR CONDITIONS POSSIBLE
IN RAIN SHOWERS AS A COLD FRONT MOVES THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...WGH
NEAR TERM...BANACOS
SHORT TERM...WGH
LONG TERM...TABER
AVIATION...TABER/SLW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
318 PM EDT FRI APR 12 2013
.SYNOPSIS...
UNSETTLED WEATHER EXPECTED THROUGH SUNDAY AFTERNOON AS AN UPPER
LEVEL DISTURBANCE REMAINS ACROSS THE NORTHEASTERN UNITED STATES.
HIGH PRESSURE WILL BUILD IN SUNDAY AFTERNOON WITH TEMPERATURES
MODERATING THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
315 PM UPDATE..
WIDESPREAD RAIN HAS MOVED THROUGH THE CWA EARLIER THAN EXPECTED
TODAY WITH MAINLY LIGHT SHOWERS AND DRIZZLE LEFT OVER. OCCLUDED
FRONT PROGGED TO MV THRU THIS EVNG WITH A LINE OF SHOWERS
ACCOMPANYING IT THRU ABOUT MIDNIGHT. HRRR HAS FAIRLY GOOD HANDLE ON
LINE OF SHOWERS ALONG FRONT AND EXPECT THIS TO CONTINUE TO PROGRESS
THRU THE AREA TONIGHT. SHOWERS LOOK TO COME TO AN END BY ABOUT 06Z
AS S/WV CURRENTLY ACRS SRN ILLINOIS PUSHES THRU THE REGION.
BNDRY LYR EXPECTED TO RMN WARM ENUF FOR RAIN SHOWERS UP THRU ABOUT
06Z BFR COLD AIR WORKS INTO THE LOWEST LEVELS. CHC OF SNOW SHOWERS
WL LKLY BE CONFINED TO ELEVATIONS ABV 1500FT AS LOW LYRS RMN WARM.
SKIES WL BCM PRTLY CLDY FM THE SOUTH TWD DAYBREAK AND MIN TEMPS WL
RMN IN THE MID-UPR 30S TO ARND 40F ACRS FAR SRN ZONES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
315 PM UPDATE...
YET ANOTHER S/WV WL ROTATE THRU SAT AFTN AND KEEP THE CHC FOR
SHOWERS GOING. EXPECTING LESS THAN A TENTH OF AN INCH THRU THE DAY
TOMORROW. WITH PSUNNY SKIES EXPECTED TOMORROW ACROSS MAJORITY OF CWA
TEMPS WL RISE TO AROUND 50 DEGREES EXCEPT THEY MAY STAY DOWN IN THE
40S ACRS THE NORTH.
SUNDAY WL LKLY RESULT IN HIGHS BLO CLIMO ACRS NY STATE WITH COLD AIR
FILTERING IN FM CANADA ON NRLY FLOW WITH SFC HIPRES BUILDING IN FM
THE WEST. H8 TEMPS EXPECTED TO DROP TO BTWN -6C AND -9C. EXPECT
WINDS TO BE OUT OF THE WEST BUT LITTLE CHC FOR LK EFFECT OVR FAR NRN
ZONES WITH DELTA T`S EARLY IN THE DAY ARND 12C AND HV KEPT LO-SLGT
CHC POPS THRU 18Z SUNDAY.
HIPRES WL END THE SHORT TERM WITH NO WX EXPECTED FM ABOUT SUN AFTN
THRU THE DAY MONDAY. TEMPS WL MODERATE THRU EARLY NEXT WEEK WITH
MAXES PROGGED TO BE IN THE 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 PM UPDATE...
FOLLOWED WPC GUIDANCE WITH A PATTERN THAT LOOKS SIMILAR TO THIS
PAST WEEK. EARLY IN THE PERIOD RIDGING IN THE EAST AND A TROF OVER
THE DESERT SOUTHWEST WILL KEEP US WITH A WARM FLOW OF AIR WITH
850S AROUND 12C TUESDAY MORNING. EVENTUALLY BOTH THE EURO AND GFS
SHOW A COLD FRONT MOVING INTO OUR AREA THEN WAFFLING BACK AND
FORTH THROUGH THE WEEK. TIMING AND PLACEMENT DIFFERENCES EXIST BUT
THE OVERALL IDEA OF A WET AND UNSETTLED PATTERN LOOK SOLID. TEMPS
ARE GENERALLY IN THE 60S AND THIS IS A GOOD START FOR NOW. AS WE
GET CLOSER AND THE DETAILS GET IRONED OUT WE MAY AGAIN SEE LARGE
NORTH/SOUTH TEMPERATURE DIFFERENCES DUE TO THE FRONTAL POSITION.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
18Z UPDATE...
LOW END MVFR CIGS WILL CONTINUE THROUGH EARLY EVENING WITH SCT.
RAIN SHOWERS. INITIALLY THESE SHOWERS THROUGH 21Z MAY BE STEADY
ENOUGH TO PRODUCE IFR VSBYS AT KRME BUT BEYOND THAT MAINLY VFR
VSBYS EXPECTED. CIGS WILL BE MUCH MORE PROBLEMATIC WITH A LOWERING
INVERSION THIS AFTERNOON MAKING IFR MORE LIKELY BY EVENING. IFR
VSBYS PERSIST AT KBGM THROUGH AFTERNOON...AND BECOME POSSIBLE AT
KELM/KITH/KAVP AND KRME BETWEEN 22Z AND 02Z AS THE INVERSION
LOWERS.
BEHIND A COLD FRONT TONIGHT...SOME DRIER AIR WILL WORK INTO THE
TERMINALS BETWEEN 04Z AND 08Z. SLOWLY IMPROVED RESTRICTIONS TO MVFR
AND EVENTUALLY VFR OVERNIGHT AS THIS DRIER AIR WORKS IN.
SOUTHEAST WINDS 10 GUSTING TO 20 THROUGH LATE THIS AFTERNOON
BECOMING WEST-NORTHWEST EARLY TONIGHT AT AROUND 5 KTS. WEST-
NORTHWEST WINDS SATURDAY 10 TO 15 KTS.
.OUTLOOK...
SAT TO SUN NGT...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
MON TO TUE...MVFR IN RAIN.
&&
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
302 PM EDT FRI APR 12 2013
.SYNOPSIS...
A STORM SYSTEM AND ASSOCIATED FRONTAL ZONE WILL MOVE ACROSS THE
REGION TODAY...BRINGING A SOAKING RAIN TO MUCH OF THE AREA. THE
WEEKEND WILL REMAIN UNSETTLED...WITH SCATTERED SHOWERS...AS AN
UPPER LEVEL DISTURBANCE REMAINS IN THE VICINITY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
945 AM UPDATE...
WIDESPREAD RAIN ALONG WITH ISOLD THUNDER IS MVG INTO CWA AT THIS
TIME. CLOUD-GROUND LIGHTNING STRIKES REPORTED SEVERAL HRS AGO BUT
HV SINCE DISSIPATED, HOWEVER POTENTIAL EXISTS FOR IN-CLOUD
LIGHTNING ALONG WITH A RUMBLE OF THUNDER. HWVR ELEVATED CAPE
APPEARS TO BE MORE PROMINENT IN THE NEXT HR OR TWO DOWN TO THE
SOUTH AS OPPOSED TO FURTHER NORTH, THUS HV REDUCED CHC THUNDER TO
ISOLD THUNDER FOR TDA.
MODELS ARE DOING VRY POOR WITH HANDLING OF DRY SLOT WITH LATEST
HRRR DATA HANDLING THE REFLECTIVITY GRADIENT BEST. BACK EDGE HAS
MVD INTO CNTRL PA AND TIMING OF THIS WOULD PUT IT INTO SRN TIER BY
NOON WHICH IS SIMILAR TO HRRR TIMING.
AS FOR ICING, STILL SOME POTENTIAL FOR ICING AT ELEVATIONS BTWN
1600 AND 2000 FEET PER LATEST RAP BUFKIT PROFILES. MESONET SITES
IN ISOLD LOCATIONS HANGING IN THE MID-30S WITH SHELDRAKE OB IN
SULLIVAN COUNTY BLO FRZG, THO THIS SEEMS OUT OF PLACE COMPARED TO
THOSE AROUND IT. WL ALLOW WINTER WX ADVISORY TO EXPIRE AT 15Z AND
CONTINUE SPS/HWO MENTION FOR ISOLD LOCALES POSSIBLY SEEING ICING
INTO EARLY AFTN.
WINDS WL GUST TO BETWEEN 30 AND 40 MPH FOR ANOTHER HOUR OR TWO
THIS BFR PRESSURE GRADIENT RELAXES THIS AFTN. NO OTHER CHGS NEEDED
AT THIS TIME.
610 AM UPDATE...
TEMPS ACRS THE WRN CATSKILLS CONTINUE THEIR SLOW RISE...WITH ONLY
ONE MESO SITE (EAST OF MONTICELLO...LOCH SHELDRAKE) REPORTING
32/32. LATEST LAPS PROFILES SUGGEST MAIN POTNL FOR ICING WOULD BE
IN A LAYER ROUGHLY FROM AROUND 1700-2200 FT. GIVEN THE OBSERVED
TRENDS...AND WITH PCPN NOT REACHING THE AREA FOR A FEW MORE
HRS...WE`LL LET FCST RIDE (NO NEW HEADLINES). ICING POTNL IS
DISCUSSED IN THE HWO...AND SPS MAY BE ISSUED LATER IF NEEDED FOR
ISOLATED ICING POTNL. PREV BLO...
COMPLICATED FCST W/RESPECT TO -FZRA POTNL ACRS ERN ZONES. VARYING
SOLUTIONS FOR THE LOW LVL THERMAL FIELDS...WITH NAM AND RUC
SUGGESTING THAT FAR ERN DELAWARE AND SULLIVAN COUNTIES COULD SEE
DAMMING OF COLD AIR INTO THE EARLY AFTN HRS. HOWEVER...T/TD`S ARE
VERY MARGINAL. MDL PROFILES INDICATE COOL AIR IS VERY SHALLOW WITH
A DEEP WARM ELEVATED LAYER...SUGGESTING THAT TEMPS AND TD`S COULD
ACTUALLY RISE WITH ONSET OF PCPN...AND MAIN TREND THUS FAR FOR T/TD`S
HAS BEEN FOR A VERY SLOW RISE. ADD TO THIS A PROJECTED START TIME
OF PCPN AFTER 12Z FURTHER COMPLICATING THE ISSUE. MARGINAL SITUATION
AND AFTER MUCH DEBATE WE WILL NOT ISSUE ANY ADDITIONAL ADVISORIES THIS
PCKG BUT WILL CONTINUE TO CLOSELY MONITOR. WE WILL ALLOW CRNT
ADVISORIES TO REMAIN UP INTO THE MRNG HRS FOR NRN ONEIDA AND
OTSEGO...ALTHO PCPN HERE WILL BE SPOTTY AT BEST THROUGH THE EARLY
MRNG HRS. FLOOD WATCH WILL ALSO REMAIN IN EFFECT FOR NRN ONEIDA
COUNTY DUE TO POTNL FOR +RA AIDED BY SNOW MELT. GUSTY SE WINDS
AHEAD OF THE FNT TDA WITH G30 LIKELY SPCLY HIER ELEVATIONS. MDLS
SHOW SI`S ARPCHNG ZERO ACRS PORTIONS OF NE PA AND THE SRN
TIER...CAN`T RULE OUT ISOLD TSRA THIS AFTN BUT WILL LET DAYSHIFT
ADD IF NEEDED.
MAIN BATCH OF RAIN WILL PULL OUT OF ERN ZONES THIS AFTN. FCST AREA
WILL BE LEFT IN SW FLOW ALOFT WITH MDLS SHOWING ANOTHER S/WV
PASSING ARND 06Z TNGT. LOW CHC POPS TO ACCOUNT FOR THIS FEATURE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
LTL CHG TO PREV FCST. S/WV`S WILL CONTINUE TO ROTATE ARND THE GT
LAKES UPR LOW...WITH MDLS INDICATING ONE FOR SAT AFTN AND ANOTHER
LATE SAT NGT AND SUN MRNG. SCT -SHRA WITH SOME -SHSN LATER AT
NGT. PSSG OF SUNDAY S/WV SHUD BEGIN A TREND OF IMPROVING
CONDITIONS...WITH HI PRES OVER THE RNG ON SUN NGT,
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
3 PM UPDATE...
FOLLOWED WPC GUIDANCE WITH A PATTERN THAT LOOKS SIMILAR TO THIS
PAST WEEK. EARLY IN THE PERIOD RIDGING IN THE EAST AND A TROF OVER
THE DESERT SOUTHWEST WILL KEEP US WITH A WARM FLOW OF AIR WITH
850S AROUND 12C TUESDAY MORNING. EVENTUALLY BOTH THE EURO AND GFS
SHOW A COLD FRONT MOVING INTO OUR AREA THEN WAFFLING BACK AND
FORTH THROUGH THE WEEK. TIMING AND PLACEMENT DIFFERENCES EXIST BUT
THE OVERALL IDEA OF A WET AND UNSETTLED PATTERN LOOK SOLID. TEMPS
ARE GENERALLY IN THE 60S AND THIS IS A GOOD START FOR NOW. AS WE
GET CLOSER AND THE DETAILS GET IRONED OUT WE MAY AGAIN SEE LARGE
NORTH/SOUTH TEMPERATURE DIFFERENCES DUE TO THE FRONTAL POSITION.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
18Z UPDATE...
LOW END MVFR CIGS WILL CONTINUE THROUGH EARLY EVENING WITH SCT.
RAIN SHOWERS. INITIALLY THESE SHOWERS THROUGH 21Z MAY BE STEADY
ENOUGH TO PRODUCE IFR VSBYS AT KRME BUT BEYOND THAT MAINLY VFR
VSBYS EXPECTED. CIGS WILL BE MUCH MORE PROBLEMATIC WITH A LOWERING
INVERSION THIS AFTERNOON MAKING IFR MORE LIKELY BY EVENING. IFR
VSBYS PERSIST AT KBGM THROUGH AFTERNOON...AND BECOME POSSIBLE AT
KELM/KITH/KAVP AND KRME BETWEEN 22Z AND 02Z AS THE INVERSION
LOWERS.
BEHIND A COLD FRONT TONIGHT...SOME DRIER AIR WILL WORK INTO THE
TERMINALS BETWEEN 04Z AND 08Z. SLOWLY IMPROVED RESTRICTIONS TO MVR
AND EVENTUALLY VFR OVERNIGHT AS THIS DRIER AIR WORKS IN.
SOUTHEAST WINDS 10 GUSTING TO 20 THROUGH LATE THIS AFTERNOON
BECOMING WEST-NORTHWEST EARLY TONIGHT AT AROUND 5 KTS. WEST-
NORTHWEST WINDS SATURDAY 10 TO 15 KTS.
.OUTLOOK...
SAT TO SUN NGT...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
MON TO TUE...MVFR IN RAIN.
&&
.HYDROLOGY...
520 AM FRIDAY UPDATE...
MINOR FLOODING FOR A FEW LOCATIONS AS MENTIONED BELOW FOR TODAY INTO
SATURDAY. LARGE AREA OF RAIN WITH SLOW MOVING COLD FRONT WILL MOVE
INTO THE AREA TODAY. THIS WILL YIELD ROUGHLY HALF TO THREE
QUARTERS OF AN INCH OR SO...HIGHEST IN ONEIDA COUNTY AND ALSO
PIKE/WAYNE/SULLIVAN. FOR ONEIDA COUNTY...SOME UNMELTED SNOW AND A
SATURATED GROUND FROM RECENT RAINFALL KEEPS FLOOD WATCH IN EFFECT.
A RIVER WARNING IS ALREADY OUT FOR THE MOHAWK RIVER AND DELTA DAM
BY OUR NEIGHBOR OFFICE IN ALBANY. ALSO...TIOUGHNIOGA RIVER IN
CORTLAND IS RUNNING HIGH AND IS EXPECTED TO CREST NEAR FLOOD STAGE
TONIGHT...SO FLOOD WARNING ISSUED FOR THERE /MINOR FLOODING
EXPECTED/.
WAVERLY-SAYRE ON SUSQUEHANNA WAS EARLIER FORECAST TO CREST NEAR FLOOD
STAGE BUT EXPECTATIONS HAVE DROPPED SOMEWHAT BASED ON LATEST QPF
TRENDS...THUS NO FLOOD WARNING ANTICIPATED THERE AT THIS TIME.
THAT BEING SAID...WHILE NOT TECHNICALLY FLOODING...WATER LEVELS WILL
STILL BE NOTICEABLY ELEVATED FOR MANY AREA STREAMS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NYZ009-037.
&&
$$
SYNOPSIS...
NEAR TERM...PVN
SHORT TERM...
LONG TERM...HEDEN
AVIATION...HEDEN
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
221 PM EDT FRI APR 12 2013
.SYNOPSIS...
A STORM SYSTEM AND ASSOCIATED FRONTAL ZONE WILL MOVE ACROSS THE
REGION TODAY...BRINGING A SOAKING RAIN TO MUCH OF THE AREA. THE
WEEKEND WILL REMAIN UNSETTLED...WITH SCATTERED SHOWERS...AS AN
UPPER LEVEL DISTURBANCE REMAINS IN THE VICINITY.
&&
.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...
WIDESPREAD RAIN ALONG WITH ISOLD THUNDER IS MVG INTO CWA AT THIS
TIME. CLOUD-GROUND LIGHTNING STRIKES REPORTED SEVERAL HRS AGO BUT
HV SINCE DISSIPATED, HOWEVER POTENTIAL EXISTS FOR IN-CLOUD
LIGHTNING ALONG WITH A RUMBLE OF THUNDER. HWVR ELEVATED CAPE
APPEARS TO BE MORE PROMINENT IN THE NEXT HR OR TWO DOWN TO THE
SOUTH AS OPPOSED TO FURTHER NORTH, THUS HV REDUCED CHC THUNDER TO
ISOLD THUNDER FOR TDA.
MODELS ARE DOING VRY POOR WITH HANDLING OF DRY SLOT WITH LATEST
HRRR DATA HANDLING THE REFLECTIVITY GRADIENT BEST. BACK EDGE HAS
MVD INTO CNTRL PA AND TIMING OF THIS WOULD PUT IT INTO SRN TIER BY
NOON WHICH IS SIMILAR TO HRRR TIMING.
AS FOR ICING, STILL SOME POTENTIAL FOR ICING AT ELEVATIONS BTWN
1600 AND 2000 FEET PER LATEST RAP BUFKIT PROFILES. MESONET SITES
IN ISOLD LOCATIONS HANGING IN THE MID-30S WITH SHELDRAKE OB IN
SULLIVAN COUNTY BLO FRZG, THO THIS SEEMS OUT OF PLACE COMPARED TO
THOSE AROUND IT. WL ALLOW WINTER WX ADVISORY TO EXPIRE AT 15Z AND
CONTINUE SPS/HWO MENTION FOR ISOLD LOCALES POSSIBLY SEEING ICING
INTO EARLY AFTN.
WINDS WL GUST TO BETWEEN 30 AND 40 MPH FOR ANOTHER HOUR OR TWO
THIS BFR PRESSURE GRADIENT RELAXES THIS AFTN. NO OTHER CHGS NEEDED
AT THIS TIME.
610 AM UPDATE...
TEMPS ACRS THE WRN CATSKILLS CONTINUE THEIR SLOW RISE...WITH ONLY
ONE MESO SITE (EAST OF MONTICELLO...LOCH SHELDRAKE) REPORTING
32/32. LATEST LAPS PROFILES SUGGEST MAIN POTNL FOR ICING WOULD BE
IN A LAYER ROUGHLY FROM AROUND 1700-2200 FT. GIVEN THE OBSERVED
TRENDS...AND WITH PCPN NOT REACHING THE AREA FOR A FEW MORE
HRS...WE`LL LET FCST RIDE (NO NEW HEADLINES). ICING POTNL IS
DISCUSSED IN THE HWO...AND SPS MAY BE ISSUED LATER IF NEEDED FOR
ISOLATED ICING POTNL. PREV BLO...
COMPLICATED FCST W/RESPECT TO -FZRA POTNL ACRS ERN ZONES. VARYING
SOLUTIONS FOR THE LOW LVL THERMAL FIELDS...WITH NAM AND RUC
SUGGESTING THAT FAR ERN DELAWARE AND SULLIVAN COUNTIES COULD SEE
DAMMING OF COLD AIR INTO THE EARLY AFTN HRS. HOWEVER...T/TD`S ARE
VERY MARGINAL. MDL PROFILES INDICATE COOL AIR IS VERY SHALLOW WITH
A DEEP WARM ELEVATED LAYER...SUGGESTING THAT TEMPS AND TD`S COULD
ACTUALLY RISE WITH ONSET OF PCPN...AND MAIN TREND THUS FAR FOR T/TD`S
HAS BEEN FOR A VERY SLOW RISE. ADD TO THIS A PROJECTED START TIME
OF PCPN AFTER 12Z FURTHER COMPLICATING THE ISSUE. MARGINAL SITUATION
AND AFTER MUCH DEBATE WE WILL NOT ISSUE ANY ADDITIONAL ADVISORIES THIS
PCKG BUT WILL CONTINUE TO CLOSELY MONITOR. WE WILL ALLOW CRNT
ADVISORIES TO REMAIN UP INTO THE MRNG HRS FOR NRN ONEIDA AND
OTSEGO...ALTHO PCPN HERE WILL BE SPOTTY AT BEST THROUGH THE EARLY
MRNG HRS. FLOOD WATCH WILL ALSO REMAIN IN EFFECT FOR NRN ONEIDA
COUNTY DUE TO POTNL FOR +RA AIDED BY SNOW MELT. GUSTY SE WINDS
AHEAD OF THE FNT TDA WITH G30 LIKELY SPCLY HIER ELEVATIONS. MDLS
SHOW SI`S ARPCHNG ZERO ACRS PORTIONS OF NE PA AND THE SRN
TIER...CAN`T RULE OUT ISOLD TSRA THIS AFTN BUT WILL LET DAYSHIFT
ADD IF NEEDED.
MAIN BATCH OF RAIN WILL PULL OUT OF ERN ZONES THIS AFTN. FCST AREA
WILL BE LEFT IN SW FLOW ALOFT WITH MDLS SHOWING ANOTHER S/WV
PASSING ARND 06Z TNGT. LOW CHC POPS TO ACCOUNT FOR THIS FEATURE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
LTL CHG TO PREV FCST. S/WV`S WILL CONTINUE TO ROTATE ARND THE GT
LAKES UPR LOW...WITH MDLS INDICATING ONE FOR SAT AFTN AND ANOTHER
LATE SAT NGT AND SUN MRNG. SCT -SHRA WITH SOME -SHSN LATER AT
NGT. PSSG OF SUNDAY S/WV SHUD BEGIN A TREND OF IMPROVING
CONDITIONS...WITH HI PRES OVER THE RNG ON SUN NGT,
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US MOVES EAST
EARLY IN THE LONG TERM. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR SUNDAY NIGHT INTO MONDAY BEFORE A SLOW MOVING COLD FRONT
BRINGS RAIN SHOWERS. MUCH LIKE THIS WEEK THE FRONT WAFFLES NORTH
AND SOUTH ACROSS THE AREA TUESDAY TO THURSDAY. LATE THURSDAY
MODELS BRING A STRONG COLD FRONT AND UPPER LEVEL TROF. MODELS
TIMING MAY BE TOO FAST WITH THE DEEP TROF IN THE WEST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
18Z UPDATE...
LOW END MVFR CIGS WILL CONTINUE THROUGH EARLY EVENING WITH SCT.
RAIN SHOWERS. INITIALLY THESE SHOWERS THROUGH 21Z MAY BE STEADY
ENOUGH TO PRODUCE IFR VSBYS AT KRME BUT BEYOND THAT MAINLY VFR
VSBYS EXPECTED. CIGS WILL BE MUCH MORE PROBLEMATIC WITH A LOWERING
INVERSION THIS AFTERNOON MAKING IFR MORE LIKELY BY EVENING. IFR
VSBYS PERSIST AT KBGM THROUGH AFTERNOON...AND BECOME POSSIBLE AT
KELM/KITH/KAVP AND KRME BETWEEN 22Z AND 02Z AS THE INVERSION
LOWERS.
BEHIND A COLD FRONT TONIGHT...SOME DRIER AIR WILL WORK INTO THE
TERMINALS BETWEEN 04Z AND 08Z. SLOWLY IMPROVED RESTRICTIONS TO MVR
AND EVENTUALLY VFR OVERNIGHT AS THIS DRIER AIR WORKS IN.
SOUTHEAST WINDS 10 GUSTING TO 20 THROUGH LATE THIS AFTERNOON
BECOMING WEST-NORTHWEST EARLY TONIGHT AT AROUND 5 KTS. WEST-
NORTHWEST WINDS SATURDAY 10 TO 15 KTS.
.OUTLOOK...
SAT TO SUN NGT...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
MON TO TUE...MVFR IN RAIN.
&&
.HYDROLOGY...
520 AM FRIDAY UPDATE...
MINOR FLOODING FOR A FEW LOCATIONS AS MENTIONED BELOW FOR TODAY INTO
SATURDAY. LARGE AREA OF RAIN WITH SLOW MOVING COLD FRONT WILL MOVE
INTO THE AREA TODAY. THIS WILL YIELD ROUGHLY HALF TO THREE
QUARTERS OF AN INCH OR SO...HIGHEST IN ONEIDA COUNTY AND ALSO
PIKE/WAYNE/SULLIVAN. FOR ONEIDA COUNTY...SOME UNMELTED SNOW AND A
SATURATED GROUND FROM RECENT RAINFALL KEEPS FLOOD WATCH IN EFFECT.
A RIVER WARNING IS ALREADY OUT FOR THE MOHAWK RIVER AND DELTA DAM
BY OUR NEIGHBOR OFFICE IN ALBANY. ALSO...TIOUGHNIOGA RIVER IN
CORTLAND IS RUNNING HIGH AND IS EXPECTED TO CREST NEAR FLOOD STAGE
TONIGHT...SO FLOOD WARNING ISSUED FOR THERE /MINOR FLOODING
EXPECTED/.
WAVERLY-SAYRE ON SUSQUEHANNA WAS EARLIER FORECAST TO CREST NEAR FLOOD
STAGE BUT EXPECTATIONS HAVE DROPPED SOMEWHAT BASED ON LATEST QPF
TRENDS...THUS NO FLOOD WARNING ANTICIPATED THERE AT THIS TIME.
THAT BEING SAID...WHILE NOT TECHNICALLY FLOODING...WATER LEVELS WILL
STILL BE NOTICEABLY ELEVATED FOR MANY AREA STREAMS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NYZ009-037.
&&
$$
SYNOPSIS...
NEAR TERM...PVN
SHORT TERM...
LONG TERM...TAC
AVIATION...HEDEN
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
221 PM EDT THU APR 11 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL INTO SATURDAY AS A COMPLEX AREA
OF LOW PRESSURE MOVES FROM THE GREAT LAKES INTO THE NORTHEAST.
RAIN SHOWERS...POSSIBLY MIXED WITH SLEET OVER PORTIONS OF CENTRAL
NEW YORK...CAN BE EXPECTED INTO FRIDAY...THEN SCATTERED RAIN OR
SNOW SHOWERS PERSISTING INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE... WE`VE TIGHTENED UP THE POP/WX GRIDS FOR THE REST
OF THE DAY INTO THIS EVE...OTHWS NO SIG CHGS ATTM.
ON THE LARGE-SCALE...E-W ORIENTED BNDRY ACRS PA CONTS TO SINK
FURTHER S ATTM...AS EVIDENCED BY THE SWD ADVANCEMENT OF THE LWR
CLOUD MASS. IN THE MEANTIME...THE "WARM FRNT ALOFT (ARND 850 MB)"
IS SITUATED ACRS NY STATE...WITH THE STEADIER PCPN FOCUSED ALG AND
N OF THIS FEATURE. BASED ON RADAR COVERAGE UPSTREAM...AND THE
LIKELY PASSAGE OF ADDTNL UPR-LVL S/WVS...WE EXPECT STEADY...ALBEIT
FAIRLY LGT PCPN...TO CONTINUE UP N THROUGH THE DAY...AND RIGHT
INTO TNT. AS FAR AS PTYP IS CONCERNED...WE`VE HAD SOME OCNL SLEET
MIX WITH THE RAIN THIS AM ACRS SOME OF OUR FAR NRN AREAS...AND
THIS MAY ALSO PERSIST THIS AFTN. A LOOK AT THE 12Z ALY/BUF RAOBS
SHOWS A DISCERNIBLE SUB-FRZG LYR BETWEEN ABT 1500 AND 4000 FT AGL.
THERE`S ALSO PLENTY OF COLD DRY AIR JUST TO OUR N...CONTINUING TO
TRY TO FEED INTO THE RGN. FORTUNATELY...SFC TEMPS ARE GENERALLY
ABV FRZG...AND GIVEN TIME OF DAY AND YEAR...WE EXPECT THIS WILL
CONTINUE TO BE THE CASE THIS AFTN...MITIGATING ANY FZRA POTENTIAL.
FARTHER S...PCPN WILL BE MUCH LGTR AND MORE SPOTTY THROUGH THE SRN TIER
OF NY...WITH DRY WX BASICALLY FORESEEN ACRS NE PA/SULLIVAN NY.
TEMPS MAY GO UP A FEW MORE DEGS THROUGH EARLY AFTN...BUT WE DON`T
EXPECT MUCH CHG FROM PRESENT READINGS...WITH LOW-LVL CAA AT PLAY N
OF THE ABV MENTIONED SFC FRNT.
620 AM UPDATE... TD`S HAVE FALLEN INTO THE L/M30S ACRS THE FINGER
LAKES AND CNTRL SRN TIER...WITH M20S JUST S OF LAKE ONTARIO. POTNL
FOR SOME PL THIS MRNG AS BAND OF SHRA ENTERS THESE AREAS. SIG
DIFFS IN THE PROFILES FOR NRN ONEIDA W/RESPECT TO A MIX LATER TDA
AND TNGT BUT WITH LOW CONFIDENCE WILL LET DAY SHIFT TAKE A CLOSER
LOOK AT THE 12Z DATA. PREV BLO...
NOT MUCH CHG FROM PREV FCST. INITIAL LOOK AT MDL GUIDANCE
APPEARED TO SHOW A COOL BIAS AT F06 W/RESPECT TO T/TD`S. GROUND
TEMPS WILL BE RELATIVELY WARM...AND WE DON`T SEE SFC TEMPS OR SFC
WET BULBS GETTING BLO 32F THIS MRNG...REDUCING OR ELIMINATING ANY
FZRA THREAT. THIS HAS BEEN REFLECTED IN THE LATEST WWD GUIDANCE
WHICH LOOKS GOOD FROM OUR PERSPECTIVE. POPS INCRSNG FROM SW TO NE
AS NXT BATCH OF SHRA MOVS BACK INTO THE RGN. KEPT POTNL FOR SOME
SLEET TO MIX IN WITH THE RAIN ACRS PORTIONS OF THE CNTRL SRN TIER
AND FINGER LAKES...AND NRN ONEIDA.
FVRBL JET CONFIGURATION TNGT WITH FCST AREA IN RR QUAD OF THE 250
MB JET...COUPLED WITH A 50 KT SRLY 850 JET. GOOD ISEN LIFT TNGT
INTO FRI AHEAD OF THE OCCLUDED FNT. COOLEST AIR WILL RESIDE ACRS
ERN ZONES...BUT MDLS AGAIN MAY BE OVERDONE WITH THE LOW LVL COOL
AIR. RETAINED POTNL FOR SOME SLEET FROM NRN ONEIDA INTO THE WRN
CATSKILLS. COULD GET FAIRLY GUSTY TNGT...SPCLY HIGHER
ELEVATIONS...AS SELY FLOW INCRS.
WE`LL PRBLY SEE A GOOD 3/4 TO ONE INCH OF RAIN THU NGT INTO
FRI. WE SHOULD BE ABLE TO HANDLE THESE AMTS...BUT A FEW MAIN STEM
POINTS MAY APRCH CAUTION STAGE.
LASTLY...CAN`T RULE OUT ISOLD TSRA THIS AFTN OR TNGT...SPCLY ACRS
PA...BUT WILL JUST GO WITH SHRA FOR NOW AND LET LATER UPDATES ADD
MENTION IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
OCCLUDED FNT PASSES ON FRI...WITH BATCH OF RAIN XPCTD TO MOV OUT
OF ERN ZONES FRI AFTN. MAIN UPR TROF REMAINS OVER THE
GTLAKES...AND S/WV`S EMBEDDED IN THE SWLY FLOW ACRS NY/PA COULD
TRIGGER SCT -SHRA...WITH POTNL FOR -SHSN LATER AT NGT. A WEAK WAVE
IS EXPECTED TO PASS FRI NGT...WITH A STRONGER S/WV ON SAT.
RETAINED CHC POPS MAINLY ACRS CNTRL NY AND NRN PA...WITH ONLY SLGT
CHC POPS FAR SE ZONES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US MOVES EAST
EARLY IN THE LONG TERM. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR SUNDAY NIGHT INTO MONDAY BEFORE A SLOW MOVING COLD FRONT
BRINGS RAIN SHOWERS. MUCH LIKE THIS WEEK THE FRONT WAFFLES NORTH
AND SOUTH ACROSS THE AREA TUESDAY TO THURSDAY. LATE THURSDAY
MODELS BRING A STRONG COLD FRONT AND UPPER LEVEL TROF. MODELS
TIMING MAY BE TOO FAST WITH THE DEEP TROF IN THE WEST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
130 PM UPDATE...
AVIATION FORECAST REMAINS DIFFICULT...DUE TO COMPLICATIONS OF
BATCHES OF SHOWERS MOVING ALONG A WAFFLING FRONTAL BOUNDARY IN
SOUTHERN PA THAT WILL LIFT NORTH THE REST OF TODAY FOLLOWED BY A
COLD FRONT FRIDAY.
MOSTLY VFR NOW...BUT CIGS WILL FALL TO MVFR LATE TODAY AND THIS
EVE THEN TO IFR CIG AND MVFR VSBYS LATE TONIGHT. THE IFR WILL
CONTINUE THROUGH 12Z AND MAYBE THROUGH 18Z. KAVP THE EXCEPTION AND
MVFR CIGS NOW WHICH SHOULD CONTINUE INTO THE EVENING.
A N TO NE 5 TO 10 KTS SHIFTING TO EAST TONIGHT AND INCREASING TO
10 TO 15 KTS WITH HIGHER GUSTS.
.OUTLOOK...
FRI AFTN...MVFR WITH PDS OF IFR AS SHOWERY FRONT PASSES. IMPROVING
TO VFR LATE.
FRI NGT TO SUN NGT...VFR...PSBL MVFR IN MIXED SHWRS.
MON TO TUE...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/MDP/TAC
NEAR TERM...MLJ
SHORT TERM...
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1041 AM EDT THU APR 11 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL INTO SATURDAY AS A COMPLEX AREA
OF LOW PRESSURE MOVES FROM THE GREAT LAKES INTO THE NORTHEAST.
SHOWERS...POSSIBLY MIXED WITH SLEET OVER PORTIONS OF CENTRAL NEW
YORK...CAN BE EXPECTED INTO FRIDAY...WITH SCATTERED RAIN OR SNOW
SHOWERS PERSISTING INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE... WE`VE TIGHTENED UP THE POP/WX GRIDS FOR THE REST
OF THE DAY INTO THIS EVE...OTHWS NO SIG CHGS ATTM.
ON THE LARGE-SCALE...E-W ORIENTED BNDRY ACRS PA CONTS TO SINK
FURTHER S ATTM...AS EVIDENCED BY THE SWD ADVANCEMENT OF THE LWR
CLOUD MASS. IN THE MEANTIME...THE "WARM FRNT ALOFT (ARND 850 MB)"
IS SITUATED ACRS NY STATE...WITH THE STEADIER PCPN FOCUSED ALG AND
N OF THIS FEATURE. BASED ON RADAR COVERAGE UPSTREAM...AND THE
LIKELY PASSAGE OF ADDTNL UPR-LVL S/WVS...WE EXPECT STEADY...ALBEIT
FAIRLY LGT PCPN...TO CONTINUE UP N THROUGH THE DAY...AND RIGHT
INTO TNT. AS FAR AS PTYP IS CONCERNED...WE`VE HAD SOME OCNL SLEET
MIX WITH THE RAIN THIS AM ACRS SOME OF OUR FAR NRN AREAS...AND
THIS MAY ALSO PERSIST THIS AFTN. A LOOK AT THE 12Z ALY/BUF RAOBS
SHOWS A DISCERNIBLE SUB-FRZG LYR BETWEEN ABT 1500 AND 4000 FT AGL.
THERE`S ALSO PLENTY OF COLD DRY AIR JUST TO OUR N...CONTINUING TO
TRY TO FEED INTO THE RGN. FORTUNATELY...SFC TEMPS ARE GENERALLY
ABV FRZG...AND GIVEN TIME OF DAY AND YEAR...WE EXPECT THIS WILL
CONTINUE TO BE THE CASE THIS AFTN...MITIGATING ANY FZRA POTENTIAL.
FARTHER S...PCPN WILL BE MUCH LGTR AND MORE SPOTTY THROUGH THE SRN TIER
OF NY...WITH DRY WX BASICALLY FORESEEN ACRS NE PA/SULLIVAN NY.
TEMPS MAY GO UP A FEW MORE DEGS THROUGH EARLY AFTN...BUT WE DON`T
EXPECT MUCH CHG FROM PRESENT READINGS...WITH LOW-LVL CAA AT PLAY N
OF THE ABV MENTIONED SFC FRNT.
620 AM UPDATE... TD`S HAVE FALLEN INTO THE L/M30S ACRS THE FINGER
LAKES AND CNTRL SRN TIER...WITH M20S JUST S OF LAKE ONTARIO. POTNL
FOR SOME PL THIS MRNG AS BAND OF SHRA ENTERS THESE AREAS. SIG
DIFFS IN THE PROFILES FOR NRN ONEIDA W/RESPECT TO A MIX LATER TDA
AND TNGT BUT WITH LOW CONFIDENCE WILL LET DAY SHIFT TAKE A CLOSER
LOOK AT THE 12Z DATA. PREV BLO...
NOT MUCH CHG FROM PREV FCST. INITIAL LOOK AT MDL GUIDANCE
APPEARED TO SHOW A COOL BIAS AT F06 W/RESPECT TO T/TD`S. GROUND
TEMPS WILL BE RELATIVELY WARM...AND WE DON`T SEE SFC TEMPS OR SFC
WET BULBS GETTING BLO 32F THIS MRNG...REDUCING OR ELIMINATING ANY
FZRA THREAT. THIS HAS BEEN REFLECTED IN THE LATEST WWD GUIDANCE
WHICH LOOKS GOOD FROM OUR PERSPECTIVE. POPS INCRSNG FROM SW TO NE
AS NXT BATCH OF SHRA MOVS BACK INTO THE RGN. KEPT POTNL FOR SOME
SLEET TO MIX IN WITH THE RAIN ACRS PORTIONS OF THE CNTRL SRN TIER
AND FINGER LAKES...AND NRN ONEIDA.
FVRBL JET CONFIGURATION TNGT WITH FCST AREA IN RR QUAD OF THE 250
MB JET...COUPLED WITH A 50 KT SRLY 850 JET. GOOD ISEN LIFT TNGT
INTO FRI AHEAD OF THE OCCLUDED FNT. COOLEST AIR WILL RESIDE ACRS
ERN ZONES...BUT MDLS AGAIN MAY BE OVERDONE WITH THE LOW LVL COOL
AIR. RETAINED POTNL FOR SOME SLEET FROM NRN ONEIDA INTO THE WRN
CATSKILLS. COULD GET FAIRLY GUSTY TNGT...SPCLY HIGHER
ELEVATIONS...AS SELY FLOW INCRS.
WE`LL PRBLY SEE A GOOD 3/4 TO ONE INCH OF RAIN THU NGT INTO
FRI. WE SHOULD BE ABLE TO HANDLE THESE AMTS...BUT A FEW MAIN STEM
POINTS MAY APRCH CAUTION STAGE.
LASTLY...CAN`T RULE OUT ISOLD TSRA THIS AFTN OR TNGT...SPCLY ACRS
PA...BUT WILL JUST GO WITH SHRA FOR NOW AND LET LATER UPDATES ADD
MENTION IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
OCCLUDED FNT PASSES ON FRI...WITH BATCH OF RAIN XPCTD TO MOV OUT
OF ERN ZONES FRI AFTN. MAIN UPR TROF REMAINS OVER THE
GTLAKES...AND S/WV`S EMBEDDED IN THE SWLY FLOW ACRS NY/PA COULD
TRIGGER SCT -SHRA...WITH POTNL FOR -SHSN LATER AT NGT. A WEAK WAVE
IS EXPECTED TO PASS FRI NGT...WITH A STRONGER S/WV ON SAT.
RETAINED CHC POPS MAINLY ACRS CNTRL NY AND NRN PA...WITH ONLY SLGT
CHC POPS FAR SE ZONES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US LIFTS EARLY IN
THE LONG TERM. NW FLOW CONTINUES SAT NGT TO SUN SO POSSIBLY
FLURRIES AND SPRINKLES. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR LATE SUNDAY BEFORE A WARM FRONT LIFTS NE WITH RAIN FOR THE
AREA STARTING SUN NGT. ONCE AGAIN THIS FRONT WILL STALL ACROSS THE
AREA UNTIL WED WHEN A COLD FRONT APPROACHES AHEAD OF A LARGE UL
TROF. MODELS MAY BE TOO FAST WITH THE COLD FRONT SO OFF AND ON
SHOWERS MOST LIKELY SCENARIO.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
7 AM UPDATE...
AVIATION FORECAST REMAINS DIFFICULT...DUE TO COMPLICATIONS OF
BATCHES OF SHOWERS MOVING ALONG A WAFFLING FRONTAL BOUNDARY IN OUR
VICINITY. LOW LEVEL DRY AIR COURTESY OF VEERING LIGHT FLOW
BETWEEN WAVES FOUND ITS WAY INTO KSYR-KRME...LIFTING CIGS VFR
THERE THIS MORNING. OTHER TERMINALS IFR TO LOW END MVFR...EVEN
LIFR FOR HILLTOP TERMINALS KBGM AND KITH. WEAK WAVE OF SHOWERS
MOVING THROUGH EARLY THIS MORNING WILL ACTUALLY SERVE TO STIR THE
CIG WHERE IT IS VERY LOW...MAINLY MVFR AS IT MOVES THROUGH.
ADDITIONAL WAVES WILL AFFECT THE REGION FROM MIDDAY THROUGH
EVENING...THE INDIVIDUAL TIMING OF WHICH IS CHALLENGING AND LOW
CONFIDENCE. THE ASSOCIATED NEARLY STATIONARY FRONT WILL THEN
EDGE NORTHWARD WITH TIME...PERHAPS GIVING KAVP-KELM-KBGM-KITH A
RELATIVE BREAK RAIN-WISE THIS EVENING...BUT POSITIONING OF
BOUNDARY WILL CONTINUE TO FAVOR RAIN THIS EVENING FOR KSYR-KRME.
SEVERAL TERMINALS WILL CONTINUE OR RETURN TO IFR CONDITIONS
TONIGHT...ESPECIALLY AS COLD FRONT OF SYSTEM MOVES INTO AREA
TOWARDS 12Z FRIDAY. WINDS THROUGH THE TAF PERIOD WILL BE LIGHT YET
VEERING WITH TIME...GENERALLY FROM A NORTHERLY DIRECTION THIS
MORNING TO AND EASTERLY ONE BY THIS EVENING...EVEN TOWARDS
SOUTHEAST OVERNIGHT TONIGHT. SEE TAFS FOR SPECIFICS.
.OUTLOOK...
FRI...MVFR WITH PDS OF IFR AS SHOWERY FRONT PASSES...ESPECIALLY
MORNING.
SAT AND SUN...VFR...PSBL MVFR IN MIXED SHWRS.
SUN NGT AND MON...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/MDP/TAC
NEAR TERM...MLJ
SHORT TERM...
LONG TERM...TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
821 AM EDT THU APR 11 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL INTO SATURDAY AS A COMPLEX AREA
OF LOW PRESSURE MOVES FROM THE GREAT LAKES INTO THE NORTHEAST.
SHOWERS...POSSIBLY MIXED WITH SLEET OVER PORTIONS OF CENTRAL NEW
YORK...CAN BE EXPECTED INTO FRIDAY...WITH SCATTERED RAIN OR SNOW
SHOWERS PERSISTING INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
620 AM UPDATE...
TD`S HAVE FALLEN INTO THE L/M30S ACRS THE FINGER LAKES AND CNTRL
SRN TIER...WITH M20S JUST S OF LAKE ONTARIO. POTNL FOR SOME PL THIS
MRNG AS BAND OF SHRA ENTERS THESE AREAS. SIG DIFFS IN THE PROFILES
FOR NRN ONEIDA W/RESPECT TO A MIX LATER TDA AND TNGT BUT WITH LOW
CONFIDENCE WILL LET DAY SHIFT TAKE A CLOSER LOOK AT THE 12Z DATA.
PREV BLO...
NOT MUCH CHG FROM
PREV FCST. INITIAL LOOK AT MDL GUIDANCE APPEARED TO SHOW A COOL
BIAS AT F06 W/RESPECT TO T/TD`S. GROUND TEMPS WILL BE RELATIVELY
WARM...AND WE DON`T SEE SFC TEMPS OR SFC WET BULBS GETTING BLO 32F
THIS MRNG...REDUCING OR ELIMINATING ANY FZRA THREAT. THIS HAS BEEN
REFLECTED IN THE LATEST WWD GUIDANCE WHICH LOOKS GOOD FROM OUR
PERSPECTIVE. POPS INCRSNG FROM SW TO NE AS NXT BATCH OF SHRA MOVS
BACK INTO THE RGN. KEPT POTNL FOR SOME SLEET TO MIX IN WITH THE
RAIN ACRS PORTIONS OF THE CNTRL SRN TIER AND FINGER LAKES...AND
NRN ONEIDA.
FVRBL JET CONFIGURATION TNGT WITH FCST AREA IN RR QUAD OF THE 250
MB JET...COUPLED WITH A 50 KT SRLY 850 JET. GOOD ISEN LIFT TNGT
INTO FRI AHEAD OF THE OCCLUDED FNT. COOLEST AIR WILL RESIDE ACRS
ERN ZONES...BUT MDLS AGAIN MAY BE OVERDONE WITH THE LOW LVL COOL
AIR. RETAINED POTNL FOR SOME SLEET FROM NRN ONEIDA INTO THE WRN
CATSKILLS. COULD GET FAIRLY GUSTY TNGT...SPCLY HIGHER
ELEVATIONS...AS SELY FLOW INCRS.
WE`LL PRBLY SEE A GOOD 3/4 TO ONE INCH OF RAIN THU NGT INTO
FRI. WE SHOULD BE ABLE TO HANDLE THESE AMTS...BUT A FEW MAIN STEM
POINTS MAY APRCH CAUTION STAGE.
LASTLY...CAN`T RULE OUT ISOLD TSRA THIS AFTN OR TNGT...SPCLY ACRS
PA...BUT WILL JUST GO WITH SHRA FOR NOW AND LET LATER UPDATES ADD
MENTION IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
OCCLUDED FNT PASSES ON FRI...WITH BATCH OF RAIN XPCTD TO MOV OUT
OF ERN ZONES FRI AFTN. MAIN UPR TROF REMAINS OVER THE
GTLAKES...AND S/WV`S EMBEDDED IN THE SWLY FLOW ACRS NY/PA COULD
TRIGGER SCT -SHRA...WITH POTNL FOR -SHSN LATER AT NGT. A WEAK WAVE
IS EXPECTED TO PASS FRI NGT...WITH A STRONGER S/WV ON SAT.
RETAINED CHC POPS MAINLY ACRS CNTRL NY AND NRN PA...WITH ONLY SLGT
CHC POPS FAR SE ZONES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US LIFTS EARLY IN
THE LONG TERM. NW FLOW CONTINUES SAT NGT TO SUN SO POSSIBLY
FLURRIES AND SPRINKLES. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR LATE SUNDAY BEFORE A WARM FRONT LIFTS NE WITH RAIN FOR THE
AREA STARTING SUN NGT. ONCE AGAIN THIS FRONT WILL STALL ACROSS THE
AREA UNTIL WED WHEN A COLD FRONT APPROACHES AHEAD OF A LARGE UL
TROF. MODELS MAY BE TOO FAST WITH THE COLD FRONT SO OFF AND ON
SHOWERS MOST LIKELY SCENARIO.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
7 AM UPDATE...
AVIATION FORECAST REMAINS DIFFICULT...DUE TO COMPLICATIONS OF
BATCHES OF SHOWERS MOVING ALONG A WAFFLING FRONTAL BOUNDARY IN OUR
VICINITY. LOW LEVEL DRY AIR COURTESY OF VEERING LIGHT FLOW
BETWEEN WAVES FOUND ITS WAY INTO KSYR-KRME...LIFTING CIGS VFR
THERE THIS MORNING. OTHER TERMINALS IFR TO LOW END MVFR...EVEN
LIFR FOR HILLTOP TERMINALS KBGM AND KITH. WEAK WAVE OF SHOWERS
MOVING THROUGH EARLY THIS MORNING WILL ACTUALLY SERVE TO STIR THE
CIG WHERE IT IS VERY LOW...MAINLY MVFR AS IT MOVES THROUGH.
ADDITIONAL WAVES WILL AFFECT THE REGION FROM MIDDAY THROUGH
EVENING...THE INDIVIDUAL TIMING OF WHICH IS CHALLENGING AND LOW
CONFIDENCE. THE ASSOCIATED NEARLY STATIONARY FRONT WILL THEN
EDGE NORTHWARD WITH TIME...PERHAPS GIVING KAVP-KELM-KBGM-KITH A
RELATIVE BREAK RAIN-WISE THIS EVENING...BUT POSITIONING OF
BOUNDARY WILL CONTINUE TO FAVOR RAIN THIS EVENING FOR KSYR-KRME.
SEVERAL TERMINALS WILL CONTINUE OR RETURN TO IFR CONDITIONS
TONIGHT...ESPECIALLY AS COLD FRONT OF SYSTEM MOVES INTO AREA
TOWARDS 12Z FRIDAY. WINDS THROUGH THE TAF PERIOD WILL BE LIGHT YET
VEERING WITH TIME...GENERALLY FROM A NORTHERLY DIRECTION THIS
MORNING TO AND EASTERLY ONE BY THIS EVENING...EVEN TOWARDS
SOUTHEAST OVERNIGHT TONIGHT. SEE TAFS FOR SPECIFICS.
.OUTLOOK...
FRI...MVFR WITH PDS OF IFR AS SHOWERY FRONT PASSES...ESPECIALLY
MORNING.
SAT AND SUN...VFR...PSBL MVFR IN MIXED SHWRS.
SUN NGT AND MON...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/MDP/TAC
NEAR TERM...
SHORT TERM...
LONG TERM...TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
723 AM EDT THU APR 11 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL INTO SATURDAY AS A COMPLEX AREA OF
LOW PRESSURE MOVES FROM THE GREAT LAKES INTO THE NORTHEAST.
SHOWERS...POSSIBLY MIXED SLEET OVER PORTIONS OF CENTRAL NEW
YORK...CAN BE EXPECTED INTO FRIDAY...WITH SCATTERED RAIN OR SNOW
SHOWERS PERSISTING INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
620 AM UPDATE...
TD`S HAVE FALLEN INTO THE L/M30S ACRS THE FINGER LAKES AND CNTRL
SRN TIER...WITH M20S JUST S OF LAKE ONTARIO. POTNL FOR SOME PL THIS
MRNG AS BAND OF SHRA ENTERS THESE AREAS. SIG DIFFS IN THE PROFILES
FOR NRN ONEIDA W/RESPECT TO A MIX LATER TDA AND TNGT BUT WITH LOW
CONFIDENCE WILL LET DAY SHIFT TAKE A CLOSER LOOK AT THE 12Z DATA.
PREV BLO...
NOT MUCH CHG FROM
PREV FCST. INITIAL LOOK AT MDL GUIDANCE APPEARED TO SHOW A COOL
BIAS AT F06 W/RESPECT TO T/TD`S. GROUND TEMPS WILL BE RELATIVELY
WARM...AND WE DON`T SEE SFC TEMPS OR SFC WET BULBS GETTING BLO 32F
THIS MRNG...REDUCING OR ELIMINATING ANY FZRA THREAT. THIS HAS BEEN
REFLECTED IN THE LATEST WWD GUIDANCE WHICH LOOKS GOOD FROM OUR
PERSPECTIVE. POPS INCRSNG FROM SW TO NE AS NXT BATCH OF SHRA MOVS
BACK INTO THE RGN. KEPT POTNL FOR SOME SLEET TO MIX IN WITH THE
RAIN ACRS PORTIONS OF THE CNTRL SRN TIER AND FINGER LAKES...AND
NRN ONEIDA.
FVRBL JET CONFIGURATION TNGT WITH FCST AREA IN RR QUAD OF THE 250
MB JET...COUPLED WITH A 50 KT SRLY 850 JET. GOOD ISEN LIFT TNGT
INTO FRI AHEAD OF THE OCCLUDED FNT. COOLEST AIR WILL RESIDE ACRS
ERN ZONES...BUT MDLS AGAIN MAY BE OVERDONE WITH THE LOW LVL COOL
AIR. RETAINED POTNL FOR SOME SLEET FROM NRN ONEIDA INTO THE WRN
CATSKILLS. COULD GET FAIRLY GUSTY TNGT...SPCLY HIGHER ELEVATIONS...AS
SELY FLOW INCRS.
WE`LL PRBLY SEE A GOOD 3/4 TO ONE INCH OF RAIN THU NGT INTO
FRI. WE SHOULD BE ABLE TO HANDLE THESE AMTS...BUT A FEW MAIN STEM
POINTS MAY APRCH CAUTION STAGE.
LASTLY...CAN`T RULE OUT ISOLD TSRA THIS AFTN OR TNGT...SPCLY ACRS
PA...BUT WILL JUST GO WITH SHRA FOR NOW AND LET LATER UPDATES ADD
MENTION IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
OCCLUDED FNT PASSES ON FRI...WITH BATCH OF RAIN XPCTD TO MOV OUT
OF ERN ZONES FRI AFTN. MAIN UPR TROF REMAINS OVER THE
GTLAKES...AND S/WV`S EMBEDDED IN THE SWLY FLOW ACRS NY/PA COULD
TRIGGER SCT -SHRA...WITH POTNL FOR -SHSN LATER AT NGT. A WEAK WAVE
IS EXPECTED TO PASS FRI NGT...WITH A STRONGER S/WV ON SAT.
RETAINED CHC POPS MAINLY ACRS CNTRL NY AND NRN PA...WITH ONLY SLGT
CHC POPS FAR SE ZONES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US LIFTS EARLY IN
THE LONG TERM. NW FLOW CONTINUES SAT NGT TO SUN SO POSSIBLY
FLURRIES AND SPRINKLES. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR LATE SUNDAY BEFORE A WARM FRONT LIFTS NE WITH RAIN FOR THE
AREA STARTING SUN NGT. ONCE AGAIN THIS FRONT WILL STALL ACROSS THE
AREA UNTIL WED WHEN A COLD FRONT APPROACHES AHEAD OF A LARGE UL
TROF. MODELS MAY BE TOO FAST WITH THE COLD FRONT SO OFF AND ON
SHOWERS MOST LIKELY SCENARIO.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AVIATION FORECAST REMAINS DIFFICULT...DUE TO COMPLICATIONS OF
BATCHES OF SHOWERS MOVING ALONG A WAFFLING FRONTAL BOUNDARY IN OUR
VICINITY. LOW LEVEL DRY AIR COURTESY OF VEERING LIGHT FLOW BETWEEN
WAVES FOUND ITS WAY INTO KSYR-KRME...LIFTING CIGS VFR THERE THIS
MORNING. OTHER TERMINALS IFR TO LOW END MVFR...EVEN LIFR FOR
HILLTOP TERMINALS KBGM AND KITH. WEAK WAVE OF SHOWERS MOVING
THROUGH EARLY THIS MORNING WILL ACTUALLY SERVE TO STIR THE CIG
WHERE IT IS VERY LOW...MAINLY MVFR AS IT MOVES THROUGH.
ADDITIONAL WAVES WILL AFFECT THE REGION FROM MIDDAY THROUGH
EVENING...THE INDIVIDUAL TIMING OF WHICH IS CHALLENGING AND LOW
CONFIDENCE. THE ASSOCIATED NEARLY STATIONARY FRONT WILL THEN
EDGE NORTHWARD WITH TIME...PERHAPS GIVING KAVP-KELM-KBGM-KITH A
RELATIVE BREAK RAIN-WISE THIS EVENING...BUT POSITIONING OF
BOUNDARY WILL CONTINUE TO FAVOR RAIN THIS EVENING FOR KSYR-KRME.
SEVERAL TERMINALS WILL CONTINUE OR RETURN TO IFR CONDITIONS
TONIGHT...ESPECIALLY AS COLD FRONT OF SYSTEM MOVES INTO AREA
TOWARDS 12Z FRIDAY. WINDS THROUGH THE TAF PERIOD WILL BE LIGHT YET
VEERING WITH TIME...GENERALLY FROM A NORTHERLY DIRECTION THIS
MORNING TO AND EASTERLY ONE BY THIS EVENING...EVEN TOWARDS
SOUTHEAST OVERNIGHT TONIGHT. SEE TAFS FOR SPECIFICS.
.OUTLOOK...
FRI...MVFR WITH PDS OF IFR AS SHOWERY FRONT PASSES...ESPECIALLY MORNING.
SAT AND SUN...VFR...PSBL MVFR IN MIXED SHWRS.
SUN NGT AND MON...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/MDP
NEAR TERM...CMG/DGM
SHORT TERM...DGM
LONG TERM...TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
627 AM EDT THU APR 11 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL INTO SATURDAY AS A COMPLEX AREA OF LOW
PRESSURE MOVES FROM THE GREAT LAKES INTO THE NORTHEAST. SHOWERS...POSSIBLY
MIXED SLEET OVER PORTIONS OF CENTRAL NEW YORK...CAN BE EXPECTED
INTO FRIDAY...WITH SCATTERED RAIN OR SNOW SHOWERS PERSISTING INTO
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
620 AM UPDATE...
TD`S HAVE FALLEN INTO THE L/M30S ACRS THE FINGER LAKES AND CNTRL
SRN TIER...WITH M20S JUST S OF LAKE ONTARIO. POTNL FOR SOME PL THIS
MRNG AS BAND OF SHRA ENTERS THESE AREAS. SIG DIFFS IN THE PROFILES
FOR NRN ONEIDA W/RESPECT TO A MIX LATER TDA AND TNGT BUT WITH LOW
CONFIDENCE WILL LET DAY SHIFT TAKE A CLOSER LOOK AT THE 12Z DATA.
PREV BLO...
NOT MUCH CHG FROM
PREV FCST. INITIAL LOOK AT MDL GUIDANCE APPEARED TO SHOW A COOL
BIAS AT F06 W/RESPECT TO T/TD`S. GROUND TEMPS WILL BE RELATIVELY
WARM...AND WE DON`T SEE SFC TEMPS OR SFC WET BULBS GETTING BLO 32F
THIS MRNG...REDUCING OR ELIMINATING ANY FZRA THREAT. THIS HAS BEEN
REFLECTED IN THE LATEST WWD GUIDANCE WHICH LOOKS GOOD FROM OUR
PERSPECTIVE. POPS INCRSNG FROM SW TO NE AS NXT BATCH OF SHRA MOVS
BACK INTO THE RGN. KEPT POTNL FOR SOME SLEET TO MIX IN WITH THE
RAIN ACRS PORTIONS OF THE CNTRL SRN TIER AND FINGER LAKES...AND
NRN ONEIDA.
FVRBL JET CONFIGURATION TNGT WITH FCST AREA IN RR QUAD OF THE 250
MB JET...COUPLED WITH A 50 KT SRLY 850 JET. GOOD ISEN LIFT TNGT
INTO FRI AHEAD OF THE OCCLUDED FNT. COOLEST AIR WILL RESIDE ACRS
ERN ZONES...BUT MDLS AGAIN MAY BE OVERDONE WITH THE LOW LVL COOL
AIR. RETAINED POTNL FOR SOME SLEET FROM NRN ONEIDA INTO THE WRN
CATSKILLS. COULD GET FAIRLY GUSTY TNGT...SPCLY HIGHER ELEVATIONS...AS
SELY FLOW INCRS.
WE`LL PRBLY SEE A GOOD 3/4 TO ONE INCH OF RAIN THU NGT INTO
FRI. WE SHOULD BE ABLE TO HANDLE THESE AMTS...BUT A FEW MAIN STEM
POINTS MAY APRCH CAUTION STAGE.
LASTLY...CAN`T RULE OUT ISOLD TSRA THIS AFTN OR TNGT...SPCLY ACRS
PA...BUT WILL JUST GO WITH SHRA FOR NOW AND LET LATER UPDATES ADD
MENTION IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
OCCLUDED FNT PASSES ON FRI...WITH BATCH OF RAIN XPCTD TO MOV OUT
OF ERN ZONES FRI AFTN. MAIN UPR TROF REMAINS OVER THE
GTLAKES...AND S/WV`S EMBEDDED IN THE SWLY FLOW ACRS NY/PA COULD
TRIGGER SCT -SHRA...WITH POTNL FOR -SHSN LATER AT NGT. A WEAK WAVE
IS EXPECTED TO PASS FRI NGT...WITH A STRONGER S/WV ON SAT.
RETAINED CHC POPS MAINLY ACRS CNTRL NY AND NRN PA...WITH ONLY SLGT
CHC POPS FAR SE ZONES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US LIFTS EARLY IN
THE LONG TERM. NW FLOW CONTINUES SAT NGT TO SUN SO POSSIBLY
FLURRIES AND SPRINKLES. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR LATE SUNDAY BEFORE A WARM FRONT LIFTS NE WITH RAIN FOR THE
AREA STARTING SUN NGT. ONCE AGAIN THIS FRONT WILL STALL ACROSS THE
AREA UNTIL WED WHEN A COLD FRONT APPROACHES AHEAD OF A LARGE UL
TROF. MODELS MAY BE TOO FAST WITH THE COLD FRONT SO OFF AND ON
SHOWERS MOST LIKELY SCENARIO.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AVIATION FORECAST REMAINS DIFFICULT...DUE TO COMPLICATIONS OF
BATCHES OF SHOWERS MOVING ALONG A WAFFLING FRONTAL BOUNDARY IN OUR
VICINITY. QUIET AT THE MOMENT PRECIPITATION-WISE...BUT NEXT WAVE
OF SHOWERS WILL SKIM THROUGH BEGINNING AROUND 09Z IN
AVP...FOLLOWED BY REMAINDER OF TERMINALS LATER IN THE MORNING. LOW
LEVEL DRY AIR COURTESY OF VEERING LIGHT FLOW BETWEEN WAVES IS
SNEAKING INTO KSYR-KRME...LIFTING CIGS INTO MVFR OR EVEN VFR THERE
THIS MORNING. OTHER TERMINALS EXCEPT KAVP ARE IFR OR LIFR...THOUGH
NOMINAL IMPROVEMENTS MAY OCCUR TOWARDS DAWN AS VEERING FLOW ATTEMPTS
TO BRING DRY LOW LEVEL AIR.
ADDITIONAL WAVES WILL AFFECT THE REGION FROM MIDDAY THROUGH
EVENING...THE INDIVIDUAL TIMING OF WHICH IS CHALLENGING AND LOW
CONFIDENCE. THE ASSOCIATED NEARLY STATIONARY FRONT WILL THEN
ATTEMPT TO EDGE NORTHWARD WITH TIME...PERHAPS GIVING KAVP-KELM-
KBGM-KITH A RELATIVE BREAK RAIN-WISE THIS EVENING BEFORE COLD
FRONT OF THE SYSTEM APPROACHES AFTER 06Z FRIDAY...BUT POSITIONING
OF BOUNDARY WILL CONTINUE TO FAVOR RAIN THIS EVENING FOR KSYR-
KRME. SEVERAL TERMINALS WILL CONTINUE OR RETURN TO IFR CONDITIONS
THIS EVENING. WINDS THROUGH THE TAF PERIOD WILL BE LIGHT YET
VEERING WITH TIME...GENERALLY FROM A NORTHERLY DIRECTION TO AND
EASTERLY ONE...SEE TAFS FOR SPECIFICS.
.OUTLOOK...
LATE THU NIGHT TO FRI...MVFR WITH PDS OF IFR AS SHOWERY FRONT PASSES.
SAT AND SUN...VFR...PSBL MVFR IN MIXED SHWRS.
SUN NGT AND MON...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/MDP
NEAR TERM...CMG/DGM
SHORT TERM...DGM
LONG TERM...TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
327 AM EDT THU APR 11 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL INTO SATURDAY AS A COMPLEX AREA OF LOW
PRESSURE MOVES FROM THE GREAT LAKES INTO THE NORTHEAST. SHOWERS...POSSIBLY
MIXED SLEET OVER PORTIONS OF CENTRAL NEW YORK...CAN BE EXPECTED
INTO FRIDAY...WITH SCATTERED RAIN OR SNOW SHOWERS PERSISTING INTO
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NOT MUCH CHG FROM PREV FCST. INITIAL LOOK AT MDL GUIDANCE APPEARED
TO SHOW A COOL BIAS AT F06 W/RESPECT TO T/TD`S. GROUND TEMPS WILL
BE RELATIVELY WARM...AND WE DON`T SEE SFC TEMPS OR SFC WET
BULBS GETTING BLO 32F THIS MRNG...REDUCING OR ELIMINATING ANY
FZRA THREAT. THIS HAS BEEN REFLECTED IN THE LATEST WWD GUIDANCE
WHICH LOOKS GOOD FROM OUR PERSPECTIVE. POPS INCRSNG FROM SW TO NE
AS NXT BATCH OF SHRA MOVS BACK INTO THE RGN. KEPT POTNL FOR SOME
SLEET TO MIX IN WITH THE RAIN ACRS PORTIONS OF THE CNTRL SRN TIER
AND FINGER LAKES...AND NRN ONEIDA.
FVRBL JET CONFIGURATION TNGT WITH FCST AREA IN RR QUAD OF THE 250
MB JET...COUPLED WITH A 50 KT SRLY 850 JET. GOOD ISEN LIFT TNGT
INTO FRI AHEAD OF THE OCCLUDED FNT. COOLEST AIR WILL RESIDE ACRS
ERN ZONES...BUT MDLS AGAIN MAY BE OVERDONE WITH THE LOW LVL COOL
AIR. RETAINED POTNL FOR SOME SLEET FROM NRN ONEIDA INTO THE WRN
CATSKILLS. COULD GET FAIRLY GUSTY TNGT...SPCLY HIGHER ELEVATIONS...AS
SELY FLOW INCRS.
WE`LL PRBLY SEE A GOOD 3/4 TO ONE INCH OF RAIN THU NGT INTO
FRI. WE SHOULD BE ABLE TO HANDLE THESE AMTS...BUT A FEW MAIN STEM
POINTS MAY APRCH CAUTION STAGE.
LASTLY...CAN`T RULE OUT ISOLD TSRA THIS AFTN OR TNGT...SPCLY ACRS
PA...BUT WILL JUST GO WITH SHRA FOR NOW AND LET LATER UPDATES ADD
MENTION IF NEEDED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
OCCLUDED FNT PASSES ON FRI...WITH BATCH OF RAIN XPCTD TO MOV OUT
OF ERN ZONES FRI AFTN. MAIN UPR TROF REMAINS OVER THE
GTLAKES...AND S/WV`S EMBEDDED IN THE SWLY FLOW ACRS NY/PA COULD
TRIGGER SCT -SHRA...WITH POTNL FOR -SHSN LATER AT NGT. A WEAK WAVE
IS EXPECTED TO PASS FRI NGT...WITH A STRONGER S/WV ON SAT.
RETAINED CHC POPS MAINLY ACRS CNTRL NY AND NRN PA...WITH ONLY SLGT
CHC POPS FAR SE ZONES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US LIFTS EARLY IN
THE LONG TERM. NW FLOW CONTINUES SAT NGT TO SUN SO POSSIBLY
FLURRIES AND SPRINKLES. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR LATE SUNDAY BEFORE A WARM FRONT LIFTS NE WITH RAIN FOR THE
AREA STARTING SUN NGT. ONCE AGAIN THIS FRONT WILL STALL ACROSS THE
AREA UNTIL WED WHEN A COLD FRONT APPROACHES AHEAD OF A LARGE UL
TROF. MODELS MAY BE TOO FAST WITH THE COLD FRONT SO OFF AND ON
SHOWERS MOST LIKELY SCENARIO.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
AVIATION FORECAST REMAINS DIFFICULT...DUE TO COMPLICATIONS OF
BATCHES OF SHOWERS MOVING ALONG A WAFFLING FRONTAL BOUNDARY IN OUR
VICINITY. QUIET AT THE MOMENT PRECIPITATION-WISE...BUT NEXT WAVE
OF SHOWERS WILL SKIM THROUGH BEGINNING AROUND 09Z IN
AVP...FOLLOWED BY REMAINDER OF TERMINALS LATER IN THE MORNING. LOW
LEVEL DRY AIR COURTESY OF VEERING LIGHT FLOW BETWEEN WAVES IS
SNEAKING INTO KSYR-KRME...LIFTING CIGS INTO MVFR OR EVEN VFR THERE
THIS MORNING. OTHER TERMINALS EXCEPT KAVP ARE IFR OR LIFR...THOUGH
NOMINAL IMPROVEMENTS MAY OCCUR TOWARDS DAWN AS VEERING FLOW ATTEMPTS
TO BRING DRY LOW LEVEL AIR.
ADDITIONAL WAVES WILL AFFECT THE REGION FROM MIDDAY THROUGH
EVENING...THE INDIVIDUAL TIMING OF WHICH IS CHALLENGING AND LOW
CONFIDENCE. THE ASSOCIATED NEARLY STATIONARY FRONT WILL THEN
ATTEMPT TO EDGE NORTHWARD WITH TIME...PERHAPS GIVING KAVP-KELM-
KBGM-KITH A RELATIVE BREAK RAIN-WISE THIS EVENING BEFORE COLD
FRONT OF THE SYSTEM APPROACHES AFTER 06Z FRIDAY...BUT POSITIONING
OF BOUNDARY WILL CONTINUE TO FAVOR RAIN THIS EVENING FOR KSYR-
KRME. SEVERAL TERMINALS WILL CONTINUE OR RETURN TO IFR CONDITIONS
THIS EVENING. WINDS THROUGH THE TAF PERIOD WILL BE LIGHT YET
VEERING WITH TIME...GENERALLY FROM A NORTHERLY DIRECTION TO AND
EASTERLY ONE...SEE TAFS FOR SPECIFICS.
.OUTLOOK...
LATE THU NIGHT TO FRI...MVFR WITH PDS OF IFR AS SHOWERY FRONT PASSES.
SAT AND SUN...VFR...PSBL MVFR IN MIXED SHWRS.
SUN NGT AND MON...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
LONG TERM...TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
218 AM EDT THU APR 11 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY THROUGH THURSDAY
NIGHT...WITH OCCASIONAL BATCHES OF RAIN MOVING WEST TO EAST ALONG
IT THROUGH OUR REGION. THERE IS ALSO A CHANCE OF SOME SPOTTY
FREEZING RAIN OVER HIGHER ELEVATIONS OF THE FINGER LAKES IN NEW
YORK. DRIER AIR WILL FINALLY MOVE IN...AFTER A SHOWERY COLD FRONT
PASSES FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1020 PM UPDATE...
MAIN AREA OF RAIN NOW WORKING THROUGH THE TWIN TIERS AND MUCH OF
NORTHEASTERN PA AS SUCCESSIVE SHORTWAVE DISTURBANCES TRAVEL EAST
ALONG A STALLED FRONTAL BOUNDARY. LOOKING UPSTREAM...RAIN WILL
LIKELY COME TO AN END FOR A SHORT WHILE BETWEEN 4 AND 6Z...WITH
ADDITIONAL ACTIVITY THEN EXPECTED TO MOVE IN LATER ON AS THE EARLY
MORNING HRS PROGRESS. LATEST LOOK AT AVAILABLE ISENTROPIC FIELDS
SUGGEST NEUTRAL ISENTROPIC UPGLIDE WILL PERSIST THROUGH MUCH OF
THE OVERNIGHT HRS ACROSS CENTRAL AND NORTHERN ZONES...WITH ASCENT
THEN INCREASING ONCE AGAIN AFTER 12Z AS MAIN LOW-LEVEL JET AXIS
APPROACHES FROM THE WEST.
LATEST RUC MLCAPE PLAN VIEW MAPS SHOWING ANY LINGERING INSTABILITY
NOW CONFINED TO AREAS WELL SOUTH OF THE FCST AREA. DESPITE THIS
HOWEVER...SEVERAL INDIVIDUAL STRIKES STILL DETECTED AND THUS WILL
MAINTAIN THUNDER MENTION FOR A FEW MORE HRS ACROSS THE SOUTH. MAIN
CONCERN GOING INTO THU MORNING CONTINUES TO BE PROSPECTS FOR FZRA
AS HIGH PRESSURE SOUTH OF HUDSON BAY CONTINUES TO BUILD SOUTH WITH
TIME EARLY THU MORNING. AS IT STANDS RIGHT NOW...BEST PROSPECTS
WILL BE ACROSS THE CENTRAL FINGER AND NORTHERN SOUTHERN TIER
PORTIONS OF THE FCST AREA HOWEVER CONSIDERING THE AMOUNT OF LOW
STRATUS HANGING AROUND THIS EVENING COUPLED WITH THE FACT THAT
TEMPS WILL LIKELY START WARMING UP FAIRLY QUICKLY TOMORROW
MORNING...FEEL ANY ICING CONCERNS SHOULD BE KEPT TO MINIMUM.
730 PM UPDATE... A FAIRLY BUSY LATE AFTERNOON/EVENING FOR
EARLY APRIL STANDARDS CONTINUES THIS HR WITH THE NEXT MCS
APPROACHING FROM THE WEST. CONVECTION ASSOCIATED WITH THE FIRST
CLUSTER RESULTED IN WIDESPREAD WIND DAMAGE ACROSS THE LOWER
WYOMING VALLEY AND POCONOS WHERE NUMBERS REPORTS OF DOWN TREES
WERE RECEIVED. WITH THIS FEATURE GONE...ATTENTION IS QUICKLY DRAWN
BACK TO OUR WEST WITH LATEST RADAR TRENDS SHOWING AN ORGANIZED
LINE-ECHO WAVE PATTERN (LEWP) STRETCHING FROM JUST NORTH OF
PITTSBURGH NORTHEAST THROUGH CENTRAL PA AND EVENTUALLY THE CENTRAL
CENTRAL TWIN TIERS OF CENTRAL TWIN TIERS. MAIN CULPRIT CONTINUES
TO BE A SERIES OF SHORTWAVE DISTURBANCES TRAVELING ALONG A STALLED
FRONTAL BOUNDARY WHICH REMAINS POSITIONED OVER THE FAR SOUTHERN
PORTION OF THE FCST AREA THIS EVENING. WILL OBVIOUSLY HAVE TO
WATCH POTENTIAL FOR SEVERE THIS EVENING HOWEVER APPROACHING
ACTIVITY IS WORKING INTO A REGION THAT EXPERIENCED THIS
AFTERNOON/S EARLIER CONVECTION. THAT SAID...WE CURRENTLY EXPECT A
WEAKENING TREND WITH FURTHER EASTWARD PROGRESS HOWEVER CANNOT RULE
OUT THE NEED FOR A FEW ROGUE SPS STATEMENTS OR A WARNING OR TWO.
AFTER A FEW HRS...HIGH RES MODELS SHOW A GRADUAL SOUTHWARD SHIFT
TO ONGOING ACTIVITY AS FRONT SLOWLY SAGS SOUTH WITH TIME.
NORTHERLY FLOW WORKING SOUTH FROM NORTHERN NY AND SOUTHERN CANADA
WILL SET THE STAGE FOR COOLING TEMPS TOWARDS MORNING WHERE SOME
LIGHT FZRA WILL BE POSSIBLE ACROSS THE HIGHER ELEVATIONS OF THE
NORTHERN FINGER LAKES...SOUTHERN TUG HILL...AND UPPER SUSQUEHANNA
VALLEY REGIONS. WILL CONTINUE TO MONITOR.
PREVIOUS NEAR TERM DISCUSSION...
COMPLEX SCENARIO OVER THE FCST AREA WITH DFRNT DVLPG WX THREATS.
IN THE VERY NEAR TERM...LINE OF TRWS OVER WRN PA MARCHING EAST
WILL BRING CONV TO THE FCST AREA. ATTM...LOOKS AS THOUGH MORE
LIMITED AVBL CAPE SHD WEAKEN THE CELLS AND THEY MOVE EAST.
HWVR...ANY CELLS WILL NEED TO WATCHED FOR FOR SVR WIND. SPC CRNTLY
NOT XPCTG A WATCH FOR PA.
OTR CNCRN FOR THE OVRNGT IS THE PSBLTY SOME FRZG RAIN LATE. HPC
WWD GRAPHICS PAINT AN AREA OF A TENTH TO QUARTER INCH OF ICE OVER
THE FINGER LAKES. HWVR...HIGH CONFIDENCE TEMPS FCST DUE TO GOOD
AGREEMENT BETWEEN THE MAV AND MET BARELY GENERATES ANY TEMPS AT OR
BLO FRZG UNTIL VERY LATE. CORE OF THE COLD AIR IS OVER THE AREA
AFT SUNRISE TMRW...WHEN MID APRIL SUN WILL MAKE ICE FORMATION DFCLT.
HAVE ELECTED TO HOLD OFF ON ANY FLAGS FOR ICE ATTM DUE TO VERY LOW
CONFIDENCE AND CVRG.
FINAL CNCRN IS QPF AMTS. SOME CONCERN THAT ENUF RAIN COULD FALL TO
CAUSE FLOODING ISSUES. NAM WHICH HAD BEEN FCSTG THE MOST QPF HAS
SLOWLY BACKED OFF. PCPN HAS BEEN ORGANIZING IN CONV COMPLEXES AND
MVG QUICKLY. IT SEEMS AS THROUGH THE THREAT FOR WIDESPREAD FLOOD
ISSUES IS LOW FOR TNGT.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
WV EXITS EARLY THU ALLOWING FOR MID LVL CONV AND A BLDG SFC HIPRES
ON THU. THIS BRINGS THE COLDEST AIR INTO THE AREA DURING THE MRNG
THU...BUT WITH APRIL SUN...HTG DESPITE THE CLDS SHD MINIMIZE THE
ICING THREAT. LTR IN THE DAY...NEXT WV APCHS AND BNDRY BEGINS TO
LIFT NWRD YET AGAIN...BRINGING AT LEAST THE SWRN PARTS OF THE FCST
AREA BACK INTO THE WRM SECTOR BY 12Z FRI. VIGOROUS UPR WV ALONG
WITH DVLPG LL CONV SHD GENERATE A GOOD SOAKING OF RAIN LATE THU
INTO FRI...WITH THE PSBLTY OF CONV.
DRY SLOT PUSHES THRU THE ENTIRE FCST AREA BY FRI AS THE UPR LOW
DRIFTS NORTH OF THE LAKES. HWVR...ENUF LL MOISTURE AND INSTABILITY
IN THE CAA FOR SOME SCT SHWRS THRU THE END OF THE PD. CAA CONTS
THRU THE END OF THE PD AS WELL WITH H8 TEMPS DROPPING TO NEAR -6C
BY 00Z SUN. SFC TEMPS DO NOT SUPPORT ANY SNOW...AT LEAST THRU THE
END OF THE SHRT TERM.
MEX/MAV GUID CONTD IN GOOD AGREEMENT UNTIL FRI WHEN THE MAV PUSHES
TEMPS HIGHER OF THE NE ZONES...WHILE THE MET KEEPS THE COLD AIR
LOCKED IN. CONTD WITH THE BLEND OF GUID THRU THE END OF THE PD AS
A COMPROMISE FOR THE END OF THE PD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. CONTINUATION OF THE WET AND UNSETTLED
CONDITIONS IN THE LONG TERM. UPPER TROF OVER NE US LIFTS EARLY IN
THE LONG TERM. NW FLOW CONTINUES SAT NGT TO SUN SO POSSIBLY
FLURRIES AND SPRINKLES. A RIDGE OF HIGH PRESSURE WITH BRIEF DRY
AIR LATE SUNDAY BEFORE A WARM FRONT LIFTS NE WITH RAIN FOR THE
AREA STARTING SUN NGT. ONCE AGAIN THIS FRONT WILL STALL ACROSS THE
AREA UNTIL WED WHEN A COLD FRONT APPROACHES AHEAD OF A LARGE UL
TROF. MODELS MAY BE TOO FAST WITH THE COLD FRONT SO OFF AND ON
SHOWERS MOST LIKELY SCENARIO.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AVIATION FORECAST REMAINS DIFFICULT...DUE TO COMPLICATIONS OF
BATCHES OF SHOWERS MOVING ALONG A WAFFLING FRONTAL BOUNDARY IN OUR
VICINITY. QUIET AT THE MOMENT PRECIPITATION-WISE...BUT NEXT WAVE
OF SHOWERS WILL SKIM THROUGH BEGINNING AROUND 09Z IN
AVP...FOLLOWED BY REMAINDER OF TERMINALS LATER IN THE MORNING. LOW
LEVEL DRY AIR COURTESY OF VEERING LIGHT FLOW BETWEEN WAVES IS
SNEAKING INTO KSYR-KRME...LIFTING CIGS INTO MVFR OR EVEN VFR THERE
THIS MORNING. OTHER TERMINALS EXCEPT KAVP ARE IFR OR LIFR...THOUGH
NOMINAL IMPROVEMENTS MAY OCCUR TOWARDS DAWN AS VEERING FLOW ATTEMPTS
TO BRING DRY LOW LEVEL AIR.
ADDITIONAL WAVES WILL AFFECT THE REGION FROM MIDDAY THROUGH
EVENING...THE INDIVIDUAL TIMING OF WHICH IS CHALLENGING AND LOW
CONFIDENCE. THE ASSOCIATED NEARLY STATIONARY FRONT WILL THEN
ATTEMPT TO EDGE NORTHWARD WITH TIME...PERHAPS GIVING KAVP-KELM-
KBGM-KITH A RELATIVE BREAK RAIN-WISE THIS EVENING BEFORE COLD
FRONT OF THE SYSTEM APPROACHES AFTER 06Z FRIDAY...BUT POSITIONING
OF BOUNDARY WILL CONTINUE TO FAVOR RAIN THIS EVENING FOR KSYR-
KRME. SEVERAL TERMINALS WILL CONTINUE OR RETURN TO IFR CONDITIONS
THIS EVENING. WINDS THROUGH THE TAF PERIOD WILL BE LIGHT YET
VEERING WITH TIME...GENERALLY FROM A NORTHERLY DIRECTION TO AND
EASTERLY ONE...SEE TAFS FOR SPECIFICS.
.OUTLOOK...
LATE THU NIGHT TO FRI...MVFR WITH PDS OF IFR AS SHOWERY FRONT PASSES.
SAT AND SUN...VFR...PSBL MVFR IN MIXED SHWRS.
SUN NGT AND MON...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/MDP
NEAR TERM...CMG/DGM
SHORT TERM...DGM
LONG TERM...TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
103 AM CDT THU APR 11 2013
.UPDATE...
ISSUED AT 102 AM CDT THU APR 11 2013
LATEST RADAR REFLECTIVITY SHOWS SOME LIGHT RETURNS ADVECTING
NORTHWEST ACROSS THE JAMES RIVER BASIN EARLY THIS MORNING. SURFACE
OBSERVATIONS OVER THE LAST FEW HOURS SHOW THAT LIGHT SNOW WAS
REPORTED IN OAKES IN DICKEY COUNTY. BASED ON LATEST 04Z RAP AND
NAM...HAVE INCREASED POPS ACROSS THE SOUTH CENTRAL THROUGH THIS EVENING...AS
SOME LIGHT SNOW/RAIN MIX MAY OCCUR. OTHERWISE NO MAJOR CHANGES TO
ONGOING FORECAST. THE WINTER WEATHER ADVISORY FOR DICKEY COUNTY
SEEMS TO BE IN GOOD SHAPE.
UPDATE ISSUED AT 933 PM CDT WED APR 10 2013
NO MAJOR CHANGES WERE MADE TO THE ONGOING FORECAST. THE CURRENT
WINTER WEATHER ADVISORY FOR DICKEY COUNTY APPEARS TO BE IN GOOD
SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 715 PM CDT WED APR 10 2013
A WINTER STORM ACROSS SOUTH DAKOTA CONTINUES TO SLOWLY SPIN NORTH
INTO SOUTHEASTERN NORTH DAKOTA THIS EVENING. EVEN THOUGH REGIONAL
RADARS ARE DETECTING ECHOES ACROSS SOUTH CENTRAL NORTH DAKOTA INTO
THE JAMES RIVER BASIN...NONE OF THE SNOW IS REACHING THE GROUND.
THE 00 UTC KBIS SOUNDING SHOWS A LARGE DRY LAYER FROM THE SURFACE
TO 650 MB CAUSING THE SNOW TO EVAPORATE BEFORE REACHING THE
GROUND. THE THERMODYNAMIC PROFILE OVER DICKEY COUNTY INDICATES
THIS LAYER SHOULD BECOME SATURATED BY AROUND SUNRISE THURSDAY
MORNING. THIS SHOULD ALLOW SNOW TO BEGIN REACHING THE GROUND AND
ACCUMULATING. THE CURRENT WINTER WEATHER ADVISORY FOR DICKEY
COUNTY LOOKS GOOD FOR THIS UPDATE WITH NO MODIFICATIONS REQUIRED.
FOR THIS UPDATE...ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED
ON CURRENT OBS/TRENDS. THE UPDATED GRIDDED/TEXT PRODUCTS HAVE BEEN
SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 PM CDT WED APR 10 2013
NORTHEAST FLOW OF COOL AND DRY AIR ORIGINATING FROM SURFACE HIGH
PRESSURE ACROSS MANITOBA HAS KEPT MOST OF THE AREA SOUTH OF
INTERSTATE 94 DRY SO FAR. HOWEVER...TONIGHT...THE H500 LOW WILL
MOVE FROM NEBRASKA/SOUTH DAKOTA BORDER NORTHEAST TO SOUTHWEST
MINNESOTA BY THURSDAY EVENING. THIS WILL INCREASE THE POTENTIAL
FOR LIGHT SNOW ACROSS SOUTHEAST NORTH DAKOTA. THE COUNTIES OF
MCINTOSH AND LAMOURE AND WILL POSSIBLY SEE 1 TO 3 INCHES OF SNOW
BY THURSDAY EVENING. DICKEY COUNTY WILL SEE AROUND 4 ACROSS ITS
SOUTHEAST. SO ISSUED A WINTER WEATHER ADVISORY FRO DICKEY COUNTY
BEGINNING MIDNIGHT TONIGHT THROUGH THURSDAY EVENING.
WITH THE UPPER LOW IN MINNESOTA...THE NEXT SHORTWAVE WILL BE
SLOWED AS IT MOVES INTO EASTERN MONTANA. BUT DO THINK THERE WILL
BE A SLIGHT CHANCE FOR RAIN OR SNOW THURSDAY AFTERNOON FAR WEST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT WED APR 10 2013
HIGHLIGHTING THE EXTENDED WILL BE CONTINUED BELOW NORMAL
TEMPERATURES AND A POTENTIAL SIGNIFICANT STORM SYSTEM SATURDAY INTO
MONDAY.
BELOW NORMAL TEMPERATURES ARE CONTINUED TO BE FAVORED ACROSS WESTERN
AND CENTRAL NORTH DAKOTA FOR THE DURATION OF THE LONG TERM FORECAST
UNDER AN UPPER LEVEL CENTRAL CONUS TROUGH.
LOOKING AHEAD TO THE STORM SYSTEM LATE SATURDAY INTO MONDAY...THE
12Z DETERMINISTIC MODELS ALL HAVE AN UPPER LEVEL WAVE COMING OUT OF
THE GULF OF ALASKA AND PROPAGATING INTO THE NORTHERN PLAINS LATE
SATURDAY INTO SUNDAY. MODELS HAVE SLOWED DOWN ON THE ARRIVAL OF
PRECIPITATION TO THE WESTERN PART OF NORTH DAKOTA SINCE
YESTERDAY...WITH THE GFS STILL HAVING THE SYSTEM ARRIVE THE
EARLIEST. DEPENDING ON WHEN THE PRECIPITATION ARRIVES...EXPECT A
RAIN SNOW MIX EARLY SATURDAY NIGHT AND SUNDAY AFTERNOON IN
NORTHWESTERN AND SOUTH CENTRAL NORTH DAKOTA...WITH ALL SNOW EXPECTED
LATE SATURDAY NIGHT INTO SUNDAY MORNING AND ONCE AGAIN SUNDAY
EVENING INTO MONDAY MORNING. PRECIPITATION SHOULD BE ALL SNOW NORTH
CENTRAL FOR THE ENTIRETY OF THE SYSTEM. HEAVIEST ACCUMULATIONS LOOK
TO BE FOR NORTHERN NORTH DAKOTA. THE 12Z ECMWF IS THE DEEPEST OF THE
DETERMINISTIC MODELS WITH THE GEM MORE OF A COMPROMISE BETWEEN THE
STRONGER ECMWF AND THE LESS ORGANIZED 12 UTC GEFS AND ITS ENSEMBLE
AND MEMBERS. THIS SYSTEM WILL HAVE TO BE CLOSELY MONITORED FOR
POTENTIAL HAZARDOUS WINTER WEATHER CONDITIONS FOR NORTHERN NORTH
DAKOTA AND THE POTENTIAL ADDITION OF SIGNIFICANT SNOW WATER TO THE
SOURIS RIVER BASIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 102 AM CDT THU APR 11 2013
VFR CONDITIONS WILL GIVE WAY TO MVFR CONDITIONS IN LIGHT SNOW AFTER
12Z FOR KJMS...FOLLOWED BY KBIS AFTER 17Z... THEN KMOT AFTER 00Z...AS
THE STORM SYSTEM CURRENTLY OVER SOUTH DAKOTA MOVES NORTH. ACROSS
THE WESTERN TERMINALS KDIK/KISN...MVFR CONDITIONS WILL DEVELOP AS
CEILINGS LOWER AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE
WEST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 AM CDT
FRIDAY FOR NDZ051.
&&
$$
UPDATE...LTH
SHORT TERM...WAA
LONG TERM...MM
AVIATION...LTH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
817 PM EDT FRI APR 12 2013
.SYNOPSIS...
COOLER AIR WILL BUILD IN BEHIND OUR DEPARTING FRONTAL
SYSTEM...BRINGING COOLER THAN NORMAL TEMPERATURES INTO THE
WEEKEND. HIGH PRESSURE WILL BUILD OVER THE EAST COAST AND ALLOW
INCREASINGLY MILD AIR TO MOVE NORTHWARD INTO THE REGION STARTING
ON MONDAY. NEXT WEEK LOOKS TO BE AT OR ABOVE NORMAL FOR
TEMPERATURES WITH SEVERAL MORE CHANCES FOR RAINFALL.
&&
.NEAR TERM /THROUGH SATURDAY/...
LITTLE MORE THAN A SMALL AREA OF SHOWERS MOVING OVER THE LOWER
SUSQ VALLEY ON THE NORTHERN EDGE OF A DEVELOPING SURFACE LOW
APPROACHING THE DEL MARVA. THIS SHOULD BE MOVING OUT OF THE AREA
BY MID EVENING...LEAVING US INCREASINGLY UNDER THE INFLUENCE OF
POST FRONTAL WESTERLY FLOW.
THE OVERNIGHT WILL SEE A SMALL CHANCE OF SHOWERS DEVELOP OVER THE
NORTHWEST AND PERHAPS DOWN INTO THE LAURELS...AND SOME OF THOSE
SHOWERS MAY EVEN MIX WITH WET SNOW OVER PARTS OF THE NORTHERN
MOUNTAINS LATER TONIGHT. BUT NOTHING OF SIGNIFICANCE IS EXPECTED.
LOWS WILL FALL TO NEAR FREEZING IN THE NORTHWEST...AND RANGE TO
NEAR 40 OVER THE SOUTHEAST.
AN APPROACHING WEAK TROUGH...ALONG WITH CONTINUED LOW LEVEL COLD
ADVECTION IS LIKELY TO KEEP A FAIR AMOUNT OF STRATO-CU IN THE
PICTURE FOR MUCH OF SATURDAY...WITH THE MOST CLOUDINESS OVER THE
NORTH AND WEST...AND MORE IN THE WAY OF PARTLY SUNNY SKIES
DEVELOPING OVER THE SOUTHEAST. HIGHS WILL REMAIN SEVERAL DEGREES
COOLER THAN NORMAL FOR MID APRIL.
&&
.SHORT TERM /SATURDAY NIGHT/...
HIGH PRESSURE WILL BEGIN BUILDING IN SATURDAY NIGHT. AS THE LAST
OF THE OVER-LAKE FLOW BRINGS CLOUDS AND LIGHT PRECIP TO THE
NORTHWEST...COULD ONCE AGAIN BE SOME LIGHT SNOW SHOWERS IN THE
AIR...BUT NO ACCUMS ARE EXPECTED. OVERNIGHT LOWS WILL BE SEVERAL
DEGREES COOLER THAN TONIGHT...STILL MUCH BELOW NORMAL.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
THE LARGE STORM THAT BROUGHT THE RECENT BOUT OF HEAVY SNOW TO THE
ROCKIES AND NORTHERN PLAINS STATES...ALONG WITH SEVERE WEATHER
ACROSS THE SOUTHERN PLAINS AND MISS VALLEY WILL SLOWLY WEAKEN AS IT
SLIDES EAST ACROSS THE UPPER GREAT LAKES TONIGHT AND SATURDAY.
THE SFC AND SLOWLY FILLING UPPER LOW...WILL WEAKEN AND ELONGATE
EAST-WEST ACROSS ONTARIO AND SRN QUEBEC DURING THE DAY SUNDAY. SOME
CLOUDS ACROSS THE NRN AND WESTERN MTNS /AND A FEW LIGHT RAIN AND
SNOW SHOWERS/ COULD STILL LINGER EARLY SUNDAY BEFORE THE POOL OF
UNSEASONABLY COLD 850-700 MB AIR RETREATS TO THE NE ACROSS NEW
ENGLAND.
850 MB TEMPS AVERAGING AROUND -2C /SW ZONES/ TO -5C ACROSS THE NE
PART OF PENN WILL COMBINE WITH THE MEAN WNW BLYR FLOW AND PERIODS OF
CLOUDS TO KEEP MAX TEMPS 3-5 DEG F BELOW NORMAL IN MOST PLACES
ACROSS SOUTHERN AND WESTERN PENN. THE GREATEST HIGH TEMP DEPARTURES
SUNDAY WILL BE ACROSS THE AREA NORTH AND EAST OF KIPT...WHERE THE
COLDER AIR ALOFT WILL LINGER THE LONGEST. VARIABLE AMOUNTS OF
HIGH-BASED STRATO CU AND SOME ALTO CU WILL LIKELY BE PRESENT ACROSS
THE CENTRAL AND SERN VALLEYS DURING THE DAY SUNDAY.
MAX TEMPS ACROSS THE HIGH PLATEAU OF SULLIVAN COUNTY MAY ONLY MAKE
IT TO THE MID 40S SUNDAY AFTERNOON. HIGHS ELSEWHERE ACROSS CENTRAL
AND NRN PA WILL BE BETWEEN 50-55F...WHILE THE SOUTHERN TIER SEES
MAXES REACH AROUND 60 DEGREES.
A WARM FRONT WILL PUSH NORTHEAST ACROSS THE FCST AREA SUNDAY NIGHT
AND MONDAY AS THE SFC RIDGE SLIDES OFF THE MID ATLANTIC COAST.
HOWEVER...WITH PRECIPITABLE WATER STILL BELOW THREE-QUARTERS OF AN
INCH /AROUND NORMAL/ AND A LACK OF ANY SIGNIFICANT FORCING
ALOFT...EXPECT THE PERIODS OF WARM ADVECTION ALTO CU TO CONTINUE
/ALONG WITH AN INCREASING SW BREEZE OVERNIGHT. ANY PRECIP IN THE
FORM OF SHOWERS WILL BE LIGHT AND SPOTTY AT BEST.
MONDAY WILL BE FEATURE PARTLY TO MOSTLY SUNNY SKIES...A GUSTY
SOUTHERLY BREEZE AND MUCH MILDER TEMPS.
MEDIUM RANGE OPERATIONAL MODELS...AND U.S./EURO ENSEMBLES CONTINUE
TO ADVERTISE ABOVE NORMAL HEIGHTS /PLUS 1-2 SIGMA/ ACROSS THE SERN
U.S. WITH A SERIES OF SHORT WAVES RIPPLING ENE ALONG A QUASI STNRY
FRONTAL BOUNDARY THAT WILL EXTEND FROM THE CENTRAL MISS VALLEY TO
THE EASTERN GREAT LAKES MONDAY THROUGH WEDNESDAY. MOST OF THE
SHOWERS ASSOCIATED WITH THIS FRONT SHOULD STAY JUST TO THE NW OF THE
STATE TUESDAY THROUGH THURSDAY.
HOWEVER...A PUSH OF COLDER AIR DIRECTED ACROSS UPSTATE NEW YORK AND
SERN CANADA TUESDAY NIGHT AND WED SHOULD ALLOW THE FRONT TO BRIEFLY
SLIP SOUTH ACROSS THE REGION ACCOMPANIED BY A VERY SHALLOW WEDGE OF
COOLER AIR AND SCATTERED SHOWERS. THE FRONT WILL STALL OUT NEAR OR
JUST SOUTH OF THE MASON-DIXON LINE DURING THE DAY WEDNESDAY BEFORE
RETURNING AS A WARM FRONT WED NIGHT AND THURSDAY.
FROM THIS VANTAGE POINT /NEARLY 7 DAYS OUT/...NEXT WEEK`S BIGGEST
RAIN MAKER LOOKS FAIRLY SIMILAR TO THE ONE THAT JUST MOVED THROUGH
THE REGION LAST NIGHT AND EARLIER TODAY - WITH RESPECT TO
TIMING...STRENGTH OF THE CFROPA AND POTENTIAL RAINFALL AMOUNTS OF
AROUND ONE INCH IN SOME AREAS.
BLEND OF ALL OPERATIONAL AND ENSEMBLE GUIDANCE SHOWS A QUITE CHILLY
AIRMASS MOVING INTO THE REGION FOR NEXT WEEKEND WITH THE LARGE SCALE
UPPER FLOW PATTERN FAVORING BELOW NORMAL HEIGHTS OF /-1 TO -2 SIGMA/
ACROSS THE MIDWEST AND PARTS OF THE NE U.S.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
EARLY EVENING SATL LOOP SHOWS LOW CLOUDS ENTRENCHED ACROSS EASTERN
PA...WHERE A MOIST...EASTERLY FLOW OFF OF THE ATLANTIC OCEAN
PERSISTS. MEANWHILE...A WARMER/DRIER SW FLOW HAS BROUGHT PARTIAL CLEARING
AND VFR CONDS ACROSS SW PA FROM JST TO AOO AT 23Z.
A COLD FRONT...JUST ENTERING WESTERN PA AT 23Z...WILL SWEEP
EASTWARD ACROSS THE REGION THIS EVENING...BRINGING WITH IT A
LIKELY RETURN TO MVFR STRATO-CU ACROSS THE W MTNS...AS BLYR COOLS
BENEATH STRENGTHENING INVERSION. THE 23Z IFR CIG AT BFD APPEARS TO
BE SHORT-LIVED...AS UPSTREAM OBS AND 13KM RAP SUGGEST DRIER AIR
WILL OVERSPREAD NW PA BY ARND 02Z. FURTHER EAST...LOW LVL
MOISTURE WILL BE SCOURED OUT UPON ARRIVAL OF OCCLUDED FRONT AND
DRIER WESTERLY FLOW. LATEST NEAR TERM MDL DATA SUGGESTS FRONT WILL
ARRIVE AT UNV BY 01ZZ...IPT ARND 03Z...MDT ARND 04Z AND LNS ARND
05Z.
ANY MVFR STRATO-CU ACROSS THE W MTNS SHOULD LIFT TO VFR BY MIDDAY
SAT DUE TO DIURNAL HEATING/STEEPENING LAPSE RTS. BIGGEST AVIATION
CONCERN SATURDAY WILL BE THE GUSTY WEST WINDS /BUFKIT SOUNDING
DATA SUPPORT AFTN GUSTS BTWN 20-25KTS/. PASSAGE OF AN UPPER LVL
TROF WILL LIKELY SUPPORT A FEW -SHSNRA OVR THE NW MTNS DURING THE
AFTN...WHICH COULD BRIEFLY LOWER VSBYS AT BFD.
.OUTLOOK...
SUN-MON...NO SIG WX EXPECTED.
TUE...AM LOW CIGS POSSIBLE.
WED...SCT TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/GARTNER
NEAR TERM...LA CORTE/GARTNER
SHORT TERM...DANGELO/GARTNER
LONG TERM...STEINBUGL/COLBERT
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1153 AM EDT FRI APR 12 2013
.SYNOPSIS...
A STRONG COLD FRONT MOVES EAST OF THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA TODAY. DRY HIGH PRESSURE WILL THEN BUILD IN FROM
THE WEST AND PERSIST THROUGH THE WEEKEND. AN UPPER LEVEL DISTURBANCE
WILL MOVE ACROSS THE AREA SUNDAY NIGHT WITH MOISTURE AND RAIN. A
MOIST SOUTHERLY FLOW THEN DEVELOPS ACROSS THE REGION THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1145 AM...DID A QUICK UPDATE FOR TEMP AND POP TRENDS. PREFRONTAL
LINE OF SHRA NOW WELL EAST OF THE AREA. ACTUALLY FRONT GETTING
LOST IN LEE TROUGH DEVELOPMENT...BUT DEWPOINTS INDICATE THE FRONT
IS MAKING THROUGH THE NC PIEDMONT AND SOUTHERN UPSTATE. LATEST
HRRR BACKING OFF ON THE IDEA OF ISOLATED SHOWERS OVER THE NC
PIEDMONT THIS AFTERNOON. WITH DEWPOINTS LOWERING...ANY SHOWER
DEVELOPMENT SEEMS UNLIKLEY...SO WILL REMOVE THE MENTIONABLE POPS.
PREVIOUS DISCUSSION:
AT 10AM EDT...LATEST SURFACE ANALYSIS INDICATES THAT THE ACTUAL
FRONT IS LOCATED FROM JUST EAST OF BOONE...SOUTH TO ABOUT
RUTHERFORDTON TO GSP. ONLY A WIND SHIFT AT THIS TIME WITH THE FRONT.
RADARS CONTINUE TO SHOW THE PREFRONTAL LINE OF NOW JUST SHRA FROM
UNION COUNTY NC...SW THROUGH SE CHESTER COUNTY SC AND THEN SOUTH OF
GREENWOOD. THIS LINE IS DRIFTING SE AND SHOULD CLEAR THE FORECAST
AREA BY MIDDAY. THEREFORE...I HAVE ADJUSTED THE POP FIELD TO FIT THE
LATEST RADAR AND TRENDS. THE HRRR IS INDICATING THAT SOME ISOLATED
SHRA COOULD DEVELOP WITH THE FRONT OVER THE EASTERN PORTION OF THE
FORECAST AREA WITH THE FRONTAL PASSAGE THIS AFTERNOON...SO HAVE
BROUGHT SOME ISOLATED POPS BACK INTO THAT AREA. OTHERWISE...EXPECT
CLEARING TO OCCUR WITH THE INCREASINGLY DOWNSLOPE WINDS. IT WILL
ALSO BE A BREEZY AFTERNOON WITH TEMPS WARMING TO A LITTLE ABOVE
AVERAGE EAST OF THE MOUNTAINS AND NEAR NORMAL MOUNTAINS. CURRENT MAX
TEMP FORECAST LOOKS ON TRACK.
1100 UTC UPDATE...WINDS WERE UPDATED TO INCLUDE THE 06Z NAM. POPS
HAVE BEEN ADJUSTED TO FIR THE TIMING OF PRECIPITATION MOVING OFF THE
BLUE RIDGE JUST AHEAD OF THE COLD FRONT.
AT 345 AM EST FRIDAY...A CLOSED UPPER LOW WILL MOVE FROM THE PLAINS
TO THE GREAT LAKES TODAY AND TONIGHT. AN ASSOCIATED COLD FRONT WILL
CROSS OUR AREA THIS MORNING...PRECEDED BY A WEAKENING LINE OF
CONVECTION. THE CURRENT TORNADO WATCH ALONG THE INTERSTATE 77
CORRIDOR WILL EXPIRE AT 400 AM...AND BASED ON RADAR TRENDS THE LINE
WILL MOVE OUT OF OUR AREA AROUND THAT TIME. CONVECTION ALONG THE
FRONT ITSELF STILL HAS LESS CHANCE OF BEING SEVERE...WITH LESS SHEAR
AND INSTABILITY. FRONTAL PASSAGE SHOULD BE AROUND DAYBREAK.
OBSERVATIONS SHOW LOW CLOUDS LINGERING FOR SOME DISTANCE BEHIND THE
FRONT...BUT CLOUDS SHOULD BREAK UP FROM THE SW BY MID MORNING.
GUSTY S WINDS WILL VEER TO WSW EAST OF THE MOUNTAINS AND NW IN THE
MOUNTAINS...REMAINING GUSTY. HIGH TEMPERATURES WILL RUNS SLIGHTLY
ABOVE NORMAL IN THE LEE OF THE MOUNTAINS WITH A WARMING DOWNSLOPE
FLOW...AND WILL BE AROUND NORMAL IN THE MOUNTAINS IN COLD ADVECTION.
WINDS WILL DECREASE TONIGHT AS THE PRESSURE GRADIENT WEAKENS...
VEERING NW IN NC...AND W IN SC. MINIMUM TEMPERATURES WILL RUN A A
FEW DEGREES BELOW NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SAT AND SAT NITE WILL BE QUIET WITH SLOWLY
RISING HEIGHTS AS AN UPPER LOW MOVES EASTWARD JUST NORTH OF THE
GREAT LAKES AND UPPER RIDGING MOVES IN FROM THE WEST. AT THE SFC...
WEAK HIGH PRESSURE MOVES ACROSS THE AREA AS WELL. SHUD BE DRY WX
WITH HIGHS A FEW DEGREES ABOVE NORMAL. LOWS WILL BE A LITTLE BELOW
NORMAL OVER THE MTNS AND A LITTLE ABOVE ELSEWHERE. SHORT WAVES KNOCK
DOWN THE RIDGE SUN AND MOVE ACROSS THE AREA SUN NITE. THE GFS IS A
LITTLE FASTER THAN THE OTHER GUIDANCE...BUT PRECIP MOVES TO OUR SWRN
DOORSTEP BY THE END OF THE DAY SUNDAY...THEN ACROSS THE AREA SUN
NITE. LOW LEVEL MOISTURE AND ISENTROPIC LIFT...ALONG WITH UPPER
DIVERGENCE....ARE MAXIMIZED SUN NITE WITH BEST PRECIP CHC OVER THE
SRN CWFA. WITH PRECIP HOLDING OFF...HIGHS SUN WILL BE UP TO 5
DEGREES ABOVE NORMAL. CLOUDS WILL KEEP LOWS 5 TO AS MUCH AS 10
DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 325 AM FRI...SHORT WAVES SLIDE EAST OF THE AREA MONDAY WITH
RIDGING RETURNING MON NITE. PRECIP TAPERS OFF MONDAY WITH ONLY SOME
LINGERING SHRA ACROSS THE NC MTNS MON NITE. HOWEVER...THERE WILL BE
CONTINUED CLOUDINESS AS LOW LEVELS REMAIN MOIST. HIGHS MONDAY WILL
BE A COUPLE OF DEGREES ABOVE NORMAL WITH LOWS MONDAY NITE AROUND 10
DEGREES ABOVE NORMAL.
THE UPPER RIDGE IS FORECAST TO LINGER THROUGH MIDWEEK. THE ECMWF AND
GFS KEEP A FRONTAL SYSTEM NORTH OF THE AREA TUE AND WED WITH
GENERALLY DIURNAL CONVECTION IN THE MOIST SLY FLOW. THEREFORE...HAVE
SCATTERED AFTERNOON CONVECTION CONFINED TO THE MOUNTAINS. ON THU...A
COLD FRONT WILL APPROACH FROM THE WEST. THE GFS IS INITIALLY FASTER
BRINGING THE FRONT TO E TN BY THE END OF THE DAY THU...BUT THEN
SLOWS CLOSER TO THE ECMWF THU NITE. WPC LIKES THE SLIGHTLY SLOWER
ECMWF SOLN...SO FOLLOWED THEIR GUIDANCE. THIS RAMPS UP CHANCE POPS
ACROSS THE AREA ON THU. TEMPERATURES WARM TO WELL ABOVE NORMAL ON
TUE/WED AND THEN BACK TO NEAR NORMAL FOR THU DUE TO CLOUDS AND
PRECIP.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AT KCLT...IFR CIG...AND POSSIBLE VSBY RESTRICTIONS IN SHOWERS...ARE
EXPECTED AS A COLD FRONT MOVES THROUGH EARLY THIS MORNING. BASED ON
OBSERVATIONS UPSTREAM AND BEHIND THE FRONT...MVFR CIG RESTRICTIONS
MAY PERSIS AFTER FRONTAL PASSAGE...BUT SHOULD LIFT BY MID MORNING AS
DRIER AIR ARRIVES. S WINDS WILL VEER TO WSW...REMAINING GUSTY. WINDS
BECOME LIGHT NW TONIGHT. GUIDANCE DOW NO SUPPORT RESTRICTIONS EARLY
SATURDAY MORNING AS THE NEW AIR MASS IS TOO DRY.
ELSEWHERE...IFR OT MVFR CIGS WILL PERSIST AHEAD OF AND BEHIND A COLD
FRONT CROSSING THE AREA EARLY THIS MORNING. MVFR VSBY RESTRICTIONS
ARE POSSIBLE IN SHOWERS AHEAD OF THE FRONT. DRIER AIR MAY TAKE A FEW
HOURS TO ARRIVE BEHIND THE FRONT BASED ON TRENDS UPSTREAM...BUT BY
MID MORNING...VFR IS EXPECTED. S WINDS WILL VEER TO WSW IN THE
FOOTHILLS TODAY...AND NW IN THE MOUNTAINS...BECOMING RATHER GUSTY.
WINDS WILL VEER TO THE NW IN NC TONIGHT...REMAINING WSW IN SC...AND
DIMINISHING AT ALL SITE. MODEL GUIDANCE MAINTAINS VFR THROUGH EARLY
SATURDAY MORNING AS THE NEWLY ARRIVED DRIER AIR MASS WILL NOT
SUPPORT FOG.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THE
WEEKEND. MOISTURE WILL APPROACH FORM THE SOUTH EARLY NEXT WEEK...BUT
CONFIDENCE IS LIMITED ON THE POSSIBILITY OF RESTRICTIONS.
CONFIDENCE TABLE...
16-22Z 22-04Z 04-10Z 10-16Z
KCLT HIGH 99% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...LG
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
209 PM EDT THU APR 11 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA TONIGHT. DRY HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST
AND PERSIST THROUGH THE WEEKEND. AN UPPER LEVEL DISTURBANCE WILL
DEVELOP OVER THE GULF COAST SUNDAY AND BRING MOISTURE BACK ACROSS
THE REGION THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...REEVALUATING TIMING OF CONVECTION THIS AFTN. 00Z EMC
4KM WRF DOING WELL WITH TIMING OF FRONTAL CONVECTION OVER THE LOWER
TENN AND MISS VALLEYS THIS MRNG. NO DEVELOPMENT YET IN THE WARM
SECTOR EITHER ON RADAR OR ON THE MODEL PROGS FOR THE CURRENT
TIME...BUT IT SHOWS SOME ACTIVITY DEVELOPING IN 16-17Z TIMEFRAME
OVER GA. NONETHELESS THIS WOULD NOT AFFECT ANY OF OUR ZONES UNTIL
AROUND 18Z. LATEST RAP KEEPS ACTIVITY OUT OF THE AREA UNTIL CLOSER
TO 20Z. SOME OTHER HI-RES MODELS DO DEVELOP SOME ISOLATED CONVECTION
PRIOR TO 18Z THOUGH. AS A RESULT I HAVE DELAYED/LOWERED POPS
SLIGHTLY THOUGH CONTINUING TO FOCUS ON THE SAVANNAH RIVER VALLEY FOR
MIDDAY DEVELOPMENT. SEE NO REASON TO THINK THAT SEVERE THREATS ARE
ANY DIFFERENT DESPITE PERHAPS GETTING A LATER START...GIVEN CONTINUED
GUIDANCE AGREEMENT ON ENVIRONMENTAL SHEAR AND DECENT INSTABILITY.
OTHERWISE...ADJUSTED SKY COVER FOR LATEST TRENDS AND SLOWED WARMING
UNTIL LOWER STRATUS MIX OUT LATE MRNG.
AS OF 345 AM...THROUGH THIS AFTERNOON...THE CWA WILL REMAIN BETWEEN
A STRONG COLD FRONT OVER THE MISSISSIPPI RIVER VALLEY AND HIGH
PRESSURE CENTERED OVER THE WESTERN ATLANTIC. THIS PATTERN WILL
PROVIDE ANOTHER DAY OF RETURN FLOW ACROSS THE REGION. MARGINALLY
GUSTY SW WINDS ARE EXPECTED TO DEVELOP AROUND MID DAY AND REMAIN
INTO TONIGHT. RECENT SATELLITE IMAGES INDICATED A SHIELD OF FAIRLY
THICK DEBRIS CIRRUS...MOVING WEST TO EAST. IN ADDITION...A FEW BANDS
OF STRATUS MAY DEVELOP ACROSS PORTIONS OF THE PIEDMONT THIS MORNING.
AS THE H5 RIDGE BUILDS OVER THE WESTERN ATLANTIC...HEIGHTS ACROSS
THE CWA WILL DECREASE. LLVL THICKNESSES AND H85 TEMPERATURES WILL
COOL A CATE OR TWO FROM YESTERDAY. THE COMBINATION OF INCREASING SKY
COVER AND SLIGHTLY COOLER LLVL TEMPS SHOULD RESULT IN HIGH TEMPS
AROUND 5 DEGREES LOWER THAN OBSERVED YESTERDAY...OR 5 DEGREES WARMER
THAN NORMAL. HIGHS IN THE U70S TO NEAR 80 WILL COMBINE WITH SFC
DEWPOINTS IN THE L60S TO SUPPORT A BROAD FIELD OF WEAK INSTABILITY
BY MID AFTERNOON. THE INSTABILITY SHOULD SUPPORT A HEALTHY FIELD OF
CU...HOWEVER...LINGERING WARM TEMPS AROUND H65 SHOULD WEAKLY CAP
DEEP CONVECTION FROM MORNING THROUGH MID AFTERNOON.
CONDITIONS WILL BECOME MORE SUITABLE FOR DEEP CONVECTION ACROSS THE
UPPER SAVANNAH VALLEY AND PORTIONS OF THE UPSTATE DURING THE LATE
AFTERNOON HOURS. MID LEVEL HEIGHTS ARE EXPECTED TO STEADILY DECREASE
AS AN INCREASINGLY NEGATIVELY TILTED TROF PUSH ACROSS THE DEEP
SOUTH. AS THE HEIGHTS DECREASE...THE WEAK AFTERNOON H85 INVERSION
ERODES...EASING CONVECTION TO DEEPEN WITHIN A LAYER OF CAPE AROUND
1000 J/KG. IN ADDITION...THE NEGATIVELY TILTED H5-H7 TROF WILL
RESULT IN THE LLVL WINDS TO BACK. IT IS DURING THIS PERIOD OF BACK
WIND FIELDS...FROM 23Z THROUGH 5Z...THAT NE GA AND SC 0-1KM HELICITY
RANGES FROM 150 TO 250...WITH SHEAR BETWEEN 20 TO 25 M/S. SWEAT
VALUES EXCEED 300 DURING THE MID EVENING HOURS. FORECAST SOUNDINGS
INDICATE THAT SIMILAR KINEMATICS SPREAD ACROSS THE CLT METRO AREA
BETWEEN MIDNIGHT INTO 4 AM. IN FACT...THE NAM HODOGRAPHS OVER CLT
APPEARS MORE TURNED...AS BL WINDS BECOME SE.
IT IS INTERESTING TO EVALUATE THE CONVECTIVE MODE IN THE CONVECTION
ALLOWING HIGH RES MODELS. EACH SOLUTION APPEARS TO SUPPORT TWO
ROUNDS OF SIGNIFICANT CONVECTION. THE FIRST ROUND DEVELOPS WELL
AHEAD OF THE FRONTAL BAND...WITH A CLUSTER FAVORED TO INITIALIZE
ACROSS THE CENTRAL SAVANNAH RIVER VALLEY AFTER 19Z. THIS CONVECTION
APPEARS TO ORGANIZED IN A NW TO SE ORIENTED BOW...SURGING NE ACROSS
THE UPSTATE. THE SECOND ROUND IS CLOSELY ASSOCIATED WITH THE SFC
COLD FRONT. THIS ACTIVITY APPEARS TO STAY INTACT AS IT CROSS THE NE
GA AND THE WESTERN CAROLINAS. GIVEN THE AMOUNT OF
HELICITY...SHEAR...AND CAPES NEAR 1000 J/KG...THE CONVECTIVE MODE
APPEARS LESS LINEAR THAN WHEN THE FRONT WAS FURTHER WEST.
INSTEAD...SIMULATED REFLECTIVITY SUGGESTS THAT CONVECTION WILL
ARRIVE WITH THE SECOND ROUND AS A COMBINATION OF SUPERCELLS AND
SHORT LINE SEGMENTS. WE WILL CONTINUE TO HIGHLIGHT THE THREAT OF
DAMAGING WINDS AND POSSIBLY OF A TORNADO OR TWO IN THE HWO. IN
ADDITION...SEVERE HAIL MAY EXIST WITH THE SUPERCELLS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 115 PM THURSDAY...A RATHER STRAIGHTFORWARD SYNOPTIC PATTERN
DEVELOPS THROUGH THE SHORT TERM. THE MODELS AGREE WELL WITH HEIGHTS
RISING AND THE H5 FLOW TRANSITIONING FROM BROADLY CYCLONIC TO
ANTICYCLONIC THROUGH 00Z MON. THERE WILL BE NO GOOD CHANCE OF PRECIP
THROUGH THE PERIOD AS DEEP LAYERED DRYING MOVES IN FROM THE NW AND
PERSISTS UNTIL UPPER/MID CLOUDS DEVELOP OUT OF THE SW BY MID DAY
SUN. SLIGHT POPS WERE MAINTAINED VERY LATE AROUND 21Z SUN AS
ISENTROPIC LIFT DEVELOPS ALONG WITH INCREASING MOISTURE FLUX. A LOOK
AT BL THETA/E SHOWS FAIRLY WEAK CAA FRI NIGHT...HOWEVER VERY GOOD
INSOLATION AND A DOWNSLOPING COMPONENT WILL OFFSET THE COOLING AND
ALLOW MAX TEMPS A COUPLE DEGREES ABOVE NORMAL. WITH THE INCREASING
UPPER CLOUDS SUN...INSOLATION WILL BE LIMITED YET H100/H85
THICKNESSES INCREASE BY 25 M FROM SAT AFTERNOON VALUES...THUS STILL
EXPECT A CONTINUED INCREASE IN MAXIMUM TEMPS...ABOUT 4-5 DEGREES
ABOVE NORMAL. MIN TEMPS WILL BE RIGHT AROUND NORMAL WITH PERHAPS
ENOUGH COOLING ACROSS THE HIGHER NC MTN TERRAIN TO PRODUCE PATCHY OR
AREAS OF FROST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 200 PM THU...ALL MEDIUM RANGE MODELS CONTINUE TO FORECAST A
SOUTHERN STREAM WAVE TO MOVE ACROSS THE FORECAST AREA ON MONDAY.
ALSO...ALL THE MODELS SHOW SOME DEGREE OF QPF RESPONSE WITH THIS
FEATURE. THEREFORE...WILL CONTINUE WITH THE IDEA OF FEATURING
SCATTERED TYPE POPS BEGINING LATE SUNDAY NIGHT AND CONTINUING
THROUGH MONDAY. IT APPEARS THAT THE SOUTHERN PORTION OF THE AREA
MIGHT HAVE BETTER COVERAGE AND THIS WILL BE LIKELY BE REFINED WITH
LATER FORECASTS.
AFTER THE WAVE EXITS TO THE EAST MONDAY NIGHT...AN UPPER RIDGE IS
FORECAST TO DEVELOP OVER THE SE STATES AND LINGER THROUGH MIDWEEK. I
LIKE THE ECM DEPICTION OF THE SENSIBLE WEATHER IN THE TUE/WED
TIMEFRAME WHICH DEPICTS ESSENTIALLY DIURNAL TYPE SHOWERS/TSTORMS
WHICH FITS THE CONCEPTUAL MODEL OF THE EXPECTED WEATHER PATTERN.
HENCE WILL FORECAST SCATTERED AFTERNOON SHOWERS/TSTORMS...BUT KEEP
THEM CONFINED TO THE MOUNTAINS. ON THU...A COLD FRONT WILL APPROACH
FROM THE WEST AND PERHAPS MOVE THROUGH THE AREA BY LATE IN THE DAY
PER THE GFS. THE ECM IS SLOWER AND HPC HAS TAKEN A COMPROMISE
SOLUTION WHICH STILL RAMPS UP CHANCE POPS ACROSS THE AREA ON THU.
TEMPERATURES WILL BE NEAR SEASONAL LEVELS ON MONDAY AND THEN WARM TO
WELL ABOVE NORMAL ON TUE/WED AND THEN BACK TO NEAR NORMAL FOR THU
DUE TO CLOUDS AND PRECIP.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...TWO ROUNDS OF SHOWERS/THUNDERSTORMS EXPECTED TO AFFECT THE
FIELD DURING THE PERIOD. FIRST...MOIST SOUTHERLY FLOW IN WARM SECTOR
OF LOW PRESSURE SYSTEM OVER THE MIDWEST WILL ALLOW SFC BASED
CONVECTION LATE THIS AFTN IN THE AREA. INITIALLY THE ATMOSPHERE WILL
REMAIN CAPPED AND ONLY SHALLOW CU WILL BE POSSIBLE BUT THIS CAP WILL
ERODE WITH MIDLEVEL TROUGHING/COOLING LEADING TO CAPE VALUES UPWARDS
OF 500 J/KG. DEEP LAYER SHEAR IS SUFFICIENT FOR ANY RESULTING TSRA
TO PRODUCE DAMAGING WIND GUSTS...AND THIS IS THE MAIN REASON WHY THE
REGION IS INCLUDED IN SPC SLIGHT RISK. CIGS SHOULD STAY VFR WITH
AFTN CONVECTION THOUGH HEAVY RAIN MAY REDUCE VSBY TO MVFR.
CONVECTION WILL DIMINISH SOMEWHAT WITH SUNSET BUT REMAIN SUPPORTIVE
OF TSRA OVERNIGHT. ADDITIONAL ACTIVITY WILL MAINLY BE ASSOCIATED
WITH COLD FROPA PROVIDING STRONG FORCING LATE TONIGHT. SHEAR WILL BE
STRONGER AT THAT TIME...AND GIVEN THE FORCING STORMS ARE EXPECTED TO
BE ABLE TO ORGANIZE INTO A LINE WHICH COULD PRODUCE WIDESPREAD
DAMAGING WINDS. PER LATEST MESOSCALE MODEL RUNS THIS LINE SHOULD
AFFECT THE FIELD AROUND 09Z. SOME LIGHT SHOWERS OR BRIEF TS MAY
CONTINUE BEHIND THE FROPA THROUGH DAYBREAK AS WINDS BEGIN TO SHIFT
TO SW.
ELSEWHERE...GENERALLY SIMILAR TO KCLT. THE GREATEST INSTABILITY WILL
BE PRESENT OVER THE UPSTATE...PARTICULARLY WEST AND SOUTH OF KGSP.
THUNDER THIS AFTERNOON WILL BE CAPABLE OF AT DAMAGING WIND GUSTS AND
AT LEAST SMALL HAIL...WITH INSTABILITY BECOMING A LIMITING FACTOR BY
EVENING. VSBY IN THE THUNDERSTORMS COULD BE AS LOW AS 1SM THOUGH
THIS IS EXPECTED TO BE ISOLATED...WITH MVFR REASONABLY LIKELY AROUND
THE AREA. COLD FROPA WITH LINE OF POTENTIALLY SEVERE CONVECTION
EXPECTED TO ENTER THE SW MTNS AND NE GA AROUND 06Z THEN PUSH EAST OF
KCLT BY 12Z. SOME LLVL MOISTURE LINGERS BEHIND THE FRONT SO MVFR
CIGS SHOULD LAST INTO FRI MRNG.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD BACK OVER THE REGION ON
FRIDAY AND REMAIN THROUGH THE WEEKEND.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 98% MED 61% MED 69% HIGH 85%
KGSP HIGH 83% MED 62% MED 74% MED 76%
KAVL HIGH 82% MED 71% MED 76% MED 76%
KHKY HIGH 100% MED 66% MED 77% MED 73%
KGMU HIGH 83% MED 70% MED 72% MED 75%
KAND HIGH 83% MED 68% MED 73% HIGH 80%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...NED/WIMBERLEY
SHORT TERM...SBK
LONG TERM...LG
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1033 AM EDT THU APR 11 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH THE REGION FROM THE WEST TODAY AND
CROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA TONIGHT. DRY HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE WEST OVER THE WEEKEND. A
WEAK LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE WESTERN GULF COAST
ON SUNDAY AND BRING MOISTURE BACK ACROSS THE SOUTHEAST THROUGH THE
FIRST HALF OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...REEVALUATING TIMING OF CONVECTION THIS AFTN. 00Z EMC
4KM WRF DOING WELL WITH TIMING OF FRONTAL CONVECTION OVER THE LOWER
TENN AND MISS VALLEYS THIS MRNG. NO DEVELOPMENT YET IN THE WARM
SECTOR EITHER ON RADAR OR ON THE MODEL PROGS FOR THE CURRENT
TIME...BUT IT SHOWS SOME ACTIVITY DEVELOPING IN 16-17Z TIMEFRAME
OVER GA. NONETHELESS THIS WOULD NOT AFFECT ANY OF OUR ZONES UNTIL
AROUND 18Z. LATEST RAP KEEPS ACTIVITY OUT OF THE AREA UNTIL CLOSER
TO 20Z. SOME OTHER HI-RES MODELS DO DEVELOP SOME ISOLATED CONVECTION
PRIOR TO 18Z THOUGH. AS A RESULT I HAVE DELAYED/LOWERED POPS
SLIGHTLY THOUGH CONTINUING TO FOCUS ON THE SAVANNAH RIVER VALLEY FOR
MIDDAY DEVELOPMENT. SEE NO REASON TO THINK THAT SEVERE THREATS ARE
ANY DIFFERENT DESPITE PERHAPS GETTING A LATER START...GIVEN CONTINUED
GUIDANCE AGREEMENT ON ENVIRONMENTAL SHEAR AND DECENT INSTABILITY.
OTHERWISE...ADJUSTED SKY COVER FOR LATEST TRENDS AND SLOWED WARMING
UNTIL LOWER STRATUS MIX OUT LATE MRNG.
AS OF 345 AM...THROUGH THIS AFTERNOON...THE CWA WILL REMAIN BETWEEN
A STRONG COLD FRONT OVER THE MISSISSIPPI RIVER VALLEY AND HIGH
PRESSURE CENTERED OVER THE WESTERN ATLANTIC. THIS PATTERN WILL
PROVIDE ANOTHER DAY OF RETURN FLOW ACROSS THE REGION. MARGINALLY
GUSTY SW WINDS ARE EXPECTED TO DEVELOP AROUND MID DAY AND REMAIN
INTO TONIGHT. RECENT SATELLITE IMAGES INDICATED A SHIELD OF FAIRLY
THICK DEBRIS CIRRUS...MOVING WEST TO EAST. IN ADDITION...A FEW BANDS
OF STRATUS MAY DEVELOP ACROSS PORTIONS OF THE PIEDMONT THIS MORNING.
AS THE H5 RIDGE BUILDS OVER THE WESTERN ATLANTIC...HEIGHTS ACROSS
THE CWA WILL DECREASE. LLVL THICKNESSES AND H85 TEMPERATURES WILL
COOL A CATE OR TWO FROM YESTERDAY. THE COMBINATION OF INCREASING SKY
COVER AND SLIGHTLY COOLER LLVL TEMPS SHOULD RESULT IN HIGH TEMPS
AROUND 5 DEGREES LOWER THAN OBSERVED YESTERDAY...OR 5 DEGREES WARMER
THAN NORMAL. HIGHS IN THE U70S TO NEAR 80 WILL COMBINE WITH SFC
DEWPOINTS IN THE L60S TO SUPPORT A BROAD FIELD OF WEAK INSTABILITY
BY MID AFTERNOON. THE INSTABILITY SHOULD SUPPORT A HEALTHY FIELD OF
CU...HOWEVER...LINGERING WARM TEMPS AROUND H65 SHOULD WEAKLY CAP
DEEP CONVECTION FROM MORNING THROUGH MID AFTERNOON.
CONDITIONS WILL BECOME MORE SUITABLE FOR DEEP CONVECTION ACROSS THE
UPPER SAVANNAH VALLEY AND PORTIONS OF THE UPSTATE DURING THE LATE
AFTERNOON HOURS. MID LEVEL HEIGHTS ARE EXPECTED TO STEADILY DECREASE
AS AN INCREASINGLY NEGATIVELY TILTED TROF PUSH ACROSS THE DEEP
SOUTH. AS THE HEIGHTS DECREASE...THE WEAK AFTERNOON H85 INVERSION
ERODES...EASING CONVECTION TO DEEPEN WITHIN A LAYER OF CAPE AROUND
1000 J/KG. IN ADDITION...THE NEGATIVELY TILTED H5-H7 TROF WILL
RESULT IN THE LLVL WINDS TO BACK. IT IS DURING THIS PERIOD OF BACK
WIND FIELDS...FROM 23Z THROUGH 5Z...THAT NE GA AND SC 0-1KM HELICITY
RANGES FROM 150 TO 250...WITH SHEAR BETWEEN 20 TO 25 M/S. SWEAT
VALUES EXCEED 300 DURING THE MID EVENING HOURS. FORECAST SOUNDINGS
INDICATE THAT SIMILAR KINEMATICS SPREAD ACROSS THE CLT METRO AREA
BETWEEN MIDNIGHT INTO 4 AM. IN FACT...THE NAM HODOGRAPHS OVER CLT
APPEARS MORE TURNED...AS BL WINDS BECOME SE.
IT IS INTERESTING TO EVALUATE THE CONVECTIVE MODE IN THE CONVECTION
ALLOWING HIGH RES MODELS. EACH SOLUTION APPEARS TO SUPPORT TWO
ROUNDS OF SIGNIFICANT CONVECTION. THE FIRST ROUND DEVELOPS WELL
AHEAD OF THE FRONTAL BAND...WITH A CLUSTER FAVORED TO INITIALIZE
ACROSS THE CENTRAL SAVANNAH RIVER VALLEY AFTER 19Z. THIS CONVECTION
APPEARS TO ORGANIZED IN A NW TO SE ORIENTED BOW...SURGING NE ACROSS
THE UPSTATE. THE SECOND ROUND IS CLOSELY ASSOCIATED WITH THE SFC
COLD FRONT. THIS ACTIVITY APPEARS TO STAY INTACT AS IT CROSS THE NE
GA AND THE WESTERN CAROLINAS. GIVEN THE AMOUNT OF
HELICITY...SHEAR...AND CAPES NEAR 1000 J/KG...THE CONVECTIVE MODE
APPEARS LESS LINEAR THAN WHEN THE FRONT WAS FURTHER WEST.
INSTEAD...SIMULATED REFLECTIVITY SUGGESTS THAT CONVECTION WILL
ARRIVE WITH THE SECOND ROUND AS A COMBINATION OF SUPERCELLS AND
SHORT LINE SEGMENTS. WE WILL CONTINUE TO HIGHLIGHT THE THREAT OF
DAMAGING WINDS AND POSSIBLY OF A TORNADO OR TWO IN THE HWO. IN
ADDITION...SEVERE HAIL MAY EXIST WITH THE SUPERCELLS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 AM THURSDAY...THE DEPARTING COLD FRONT AND LIFTING UPPER
SHORTWAVE WILL MOVE QUICKLY EAST AWAY FROM THE FORECAST AREA THROUGH
FRIDAY MORNING...WITH THE CONVECTIVE THREAT RAPIDLY ENDING. DEEP
LAYER DRYING WILL THEN SET UP THROUGH THE DAY IN THE WSW FLOW ALOFT
AROUND THE VORTEX OVER THE GREAT LAKES REGION. LOWER LEVEL W TO NW
WINDS WILL PROVIDE DOWNSLOPING E OF THE MTNS TO DRY OUT THE BL AND
ALLOW MAXES TO WARM A COUPLE OF CATEGORIES ABOVE NORMAL DESPITE THE
FALLING POST FROPA THICKNESSES. DRY HIGH PRES WILL BUILD IN FROM THE
WEST ON SATURDAY...WITH PLENTY OF SUNSHINE AND MAX TEMPS SLIGHTLY
ABOVE NORMAL. ANTICIPATE THAT MINS WILL REMAIN JUST WARM ENOUGH TO
PRECLUDE A FROST MENTION FOR SAT NIGHT...BUT WILL HAVE TO WATCH TEMP
TRENDS ALONG THE INTERSTATE 40 CORRIDOR SINCE RADIATING CONDITIONS
WILL BE GOOD LATE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 310 AM THU...ANOTHER SRN STREAM WAVE WILL DEVELOP ALONG THE
WRN GULF COAST ON SUNDAY. DPVA ASSOCIATED WITH THIS WAVE...AS WELL
AS UPPER JET DIVERGENCE...SHOULD SHOULD CROSS THE AREA SUNDAY NIGHT.
HOWEVER...LOWER LEVEL MOISTURE AND UPGLIDE WILL LIKELY NOT SET UP
UNTIL DAYBREAK MONDAY AND COULD LINGER THROUGH MON NIGHT.
A FLAT UPPER RIDGE WILL BUILD IN BEHIND THE DEPARTING SHORTWAVE ON
MONDAY...WITH RIDGING REMAINING DOMINANT OVER THE SE THROUGH MID
WEEK AS TEMPERATURE REBOUND. HOWEVER...LOW LEVEL MOISTURE AND SRLY
FLOW WILL ALSO PERSIST UNDER THE RIDGE TO CREATE MORE CLOUDS THAN
NOT THROUGH THE PERIOD. ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE EACH DAY...ESPECIALLY OVER THE MTNS
AND DURING THE DIURNALLY FAVORED AFTN/EVENING HOURS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AT KCLT /15Z UPDATE/...MVFR STRATUS EXPECTED TO PERSIST THROUGH THE
MORNING AS THERE HAS BEEN LITTLE IMPROVEMENT NEAR THE FIELD. WARMING
AND ATTENDANT MIXING HAS BEEN SLOW AND IT APPEARS THIS WILL BE
REQUIRED TO ERODE THE STRATUS. INSTABILITY SHOULD BE SUFFICIENT TO
ALLOW SOME LOW VFR CU TO QUICKLY FILL IN BEHIND IT...ESPECIALLY IN
LIGHT OF CU DEVELOPING OVER FAR NW SC.
CURRENTLY EXPECTING SIMILAR TIMING AND PLACEMENT OF SHRA/TSRA
ASSOCIATED WITH A STRONG COLD FRONT TO THOUGHTS AT 12Z ISSUANCE.
CONVECTION ALLOWING MODELS INDICATE THAN PRE FRONTAL SHRA/TSRA WILL
DEVELOP OVER THE CENTRAL SAVANNAH RIVER VALLEY BETWEEN
19-21Z...TRACKING NE...REACHING CLT BETWEEN 22-00Z. WILL MENTION A
TEMPO BETWEEN 22-24Z...WITH PREDOMINATE TSRA STARTING AT 00Z. MVFR
CEILING SHOULD DEVELOP IN THE WAKE OF THE TSRA...REMAINING THROUGH
12Z. HOWEVER 12Z NAM AND LATEST RAP HAVE SLIGHTLY DELAYED THE ACTION
THIS AFTERNOON SO IF ANYTHING ONSET MAY BE AN HOUR LATER.
ELSEWHERE...WILL KEEP MVFR CEILING WITH SCT IFR THROUGH MID MORNING
UNTIL MIXING ERODES STRATUS. SSW WIND WILL BECOME GUSTY BY MID DAY
AND REMAIN THROUGH EARLY FRIDAY MORNING.
THE NEXT ISSUE WILL BE THE TIMING AND PLACEMENT OF SHRA/TSRA
ASSOCIATED WITH A STRONG COLD FRONT. CONVECTION ALLOWING MODELS
INDICATE THAN PRE FRONTAL SHRA/TSRA WILL DEVELOP OVER THE CENTRAL
SAVANNAH RIVER VALLEY BETWEEN 19-21Z...TRACKING NE...REACHING THE
PIEDMONT TAFS AROUND BETWEEN 20-24Z. I WILL MENTION A PROB30...WITH
PREDOMINATE TSRA STARTING AT 1Z. MVFR CEILINGS MAY SPREAD ACROSS
THE REGION IN THE WAKE OF THE FIRST ROUND OF CONVECTION. FROPA WILL
OCCUR AFTER 6Z.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD BACK OVER THE REGION ON
FRIDAY AND REMAIN THROUGH THE WEEKEND.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT HIGH 97% HIGH 88% MED 72% HIGH 100%
KGSP HIGH 91% HIGH 94% HIGH 82% HIGH 100%
KAVL HIGH 100% HIGH 95% HIGH 98% HIGH 93%
KHKY HIGH 89% HIGH 83% MED 61% HIGH 100%
KGMU HIGH 90% HIGH 86% MED 77% HIGH 93%
KAND HIGH 95% HIGH 90% HIGH 93% HIGH 98%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...HG
NEAR TERM...NED/WIMBERLEY
SHORT TERM...HG
LONG TERM...HG
AVIATION...NED/WIMBERLEY
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
121 PM CDT THU APR 11 2013
.UPDATE...
18Z AVIATION DISCUSSION UPDATED BELOW.
LIGHT SNOW CONTINUES TO WRAP INTO THE REGION EARLY THIS AFTERNOON.
EXPECT THIS TO DIMINISH INTO THE LATE AFTERNOON AND EARLY EVENING
WITH ADDITIONAL ACCUMULATIONS OF AN INCH OR TWO. WINDS DONT SEEM
TO BE MUCH OF A PROBLEM ALONG WITH BLOWING SNOW. THUS...CANCELLED
THE WINTER STORM WARNING AND ADVISORY FOR THE EASTERN PART OF THE
REGION.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
LEFT EXIT REGION RESPONSIBLE FOR TRANSIENT BANDS OF MODERATE TO
HEAVY SNOWFALL THIS MORNING. HRRR DEPICTING CURRENT CONDITIONS
FAIRLY WELL...AND TRANSITIONS AREA OF HIGHEST RETURNS/BEST FORCING
NORTH OF THE CWA BY MID DAY. ASIDE FROM MINOR CONFIGURATION
CHANGES TO HEADLINES EARLIER...WILL STICK WITH CURRENT TIMING ON
END OF ACCUMULATING SNOWFALL. SREF PROBABILITIES STILL SUGGESTING
A FEW SPOTS TO TOP 8 INCHES IN FAR EASTERN SOUTH DAKOTA/MINNESOTA
COUNTIES.
WITH THE LAST OF THE SYNOPTIC SCALE SNOWFALL MOVING OUT...MODELS
STILL HINT AT A PERSISTENT STRATUS LAYER OVER THE REGION THROUGH
THE START OF THE WEEKEND. THE LACK OF THERMAL ADVECTION...AND H85
READINGS AROUND -7C OR A STANDARD DEVIATION BELOW CLIMO...SUGGEST
FORECAST TEMPERATURES THROUGH SATURDAY WILL REMAIN WELL BELOW
NORMAL. WE WILL SEE SOME DECENT THERMAL ADVECTION BETWEEN 1 TO 3KFT
LATE IN THE PERIOD OUT WEST...HOWEVER SOUTHEASTERLY LOW LEVEL FLOW
WILL CUT DOWN ON MIXING POTENTIAL AND INCREASING MID/HIGH CLOUDS
SHOULD LIMIT DAYTIME HEATING. THUS...HIGHS STILL SOME 10-15
DEGREES BELOW NORMAL THE HIGH POINT IN TEMPERATURES THIS PERIOD.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
A LOW PRESSURE SYSTEM WILL BE APPROACHING THE AREA FROM THE WEST
WHEN THE PERIOD STARTS. WAA PRECIPITATION ON THE LEADING EDGE OF
THE SYSTEM LOOKS PRETTY CERTAIN SATURDAY NIGHT...ESPECIALLY ACROSS
THE EASTERN CWA. THE SYSTEM SWINGS TO THE NORTHEAST ON SUNDAY AND
THERE LOOKS TO BE A BREAK IN THE PRECIPITATION SUNDAY NIGHT AND
MONDAY. ANOTHER SYSTEM THEN TRACKS ACROSS THE CENTRAL OR SOUTHERN
PLAINS DURING THE LATTER HALF OF THE PERIOD. THE GFS AND THE GEM
ARE CONSIDERABLY FURTHER SOUTH WITH THIS SYSTEM THAN THE
ECMWF...SO THERE IS A POSSIBILITY THAT WE WILL REMAIN DRY.
HOWEVER...AM NOT COMFORTABLE STRAYING THAT FAR FROM THE
ALLBLEND...SO WILL LEAVE A SMALL POP IN MONDAY NIGHT THROUGH
WEDNESDAY TO ACCOUNT FOR TRACKING DIFFERENCES.
WITH NEW SNOW COVER OVER MUCH OF THE CWA...DO NOT EXPECT TO SEE
TEMPERATURES REACH MEX GUIDANCE VALUES...AND WILL STAY ABOUT 5 TO
10 DEGREES BELOW IT FOR DAYTIME HIGHS. THIS WILL RESULT IN HIGH
TEMPERATURES MAINLY IN THE 30S AND 40S...WITH OVERNIGHT LOWS IN
THE 20S.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
AREAS OF -SN AND BR WILL PERSIST AT ALL TERMINALS THROUGH THE
AFTERNOON HOURS. VSBYS AT TIMES IN HEAVIER SNOW BANDS MAY DROP TO
AROUND 1SM OR LESS. CIGS WILL GENERALLY BE IFR/MVFR. THIS
EVENING...EXPECT -SN TO CONTINUE MAINLY AT KABR AND KATY WITH -SN
GRADUALLY ENDING BY MORNING. IFR/MVFR CIGS EXPECTED TO PERSIST
THROUGH FRIDAY MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...TMT
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1054 AM CDT THU APR 11 2013
.UPDATE...
WRAPAROUND/TROWAL SNOW WILL CONTINUE THROUGH THE AFTERNOON AND
SLOWLY DIMINISH IN COVERAGE AND INTENSITY. ADJUSTED WX AND POP GRIDS
FOR THE DRYING/NO SNOW AREA SWEEPING INTO THE EASTERN CWA LATE
THIS MORNING. THIS AREA SHOULD FILL BACK IN THROUGH THE LATE
AFTERNOON AND EARLY EVENING AND THEN END. ADDITIONAL AMOUNTS OF 1
TO 3 INCHES ARE EXPECTED. READJUSTED SNOWFALL GRIDS AND INCREASED
TOTAL SNOWFALL AMOUNTS. NOT MUCH INCREASE IN TEMPERATURES THROUGH
THE AFTERNOON.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
LEFT EXIT REGION RESPONSIBLE FOR TRANSIENT BANDS OF MODERATE TO
HEAVY SNOWFALL THIS MORNING. HRRR DEPICTING CURRENT CONDITIONS
FAIRLY WELL...AND TRANSITIONS AREA OF HIGHEST RETURNS/BEST FORCING
NORTH OF THE CWA BY MID DAY. ASIDE FROM MINOR CONFIGURATION
CHANGES TO HEADLINES EARLIER...WILL STICK WITH CURRENT TIMING ON
END OF ACCUMULATING SNOWFALL. SREF PROBABILITIES STILL SUGGESTING
A FEW SPOTS TO TOP 8 INCHES IN FAR EASTERN SOUTH DAKOTA/MINNESOTA
COUNTIES.
WITH THE LAST OF THE SYNOPTIC SCALE SNOWFALL MOVING OUT...MODELS
STILL HINT AT A PERSISTENT STRATUS LAYER OVER THE REGION THROUGH
THE START OF THE WEEKEND. THE LACK OF THERMAL ADVECTION...AND H85
READINGS AROUND -7C OR A STANDARD DEVIATION BELOW CLIMO...SUGGEST
FORECAST TEMPERATURES THROUGH SATURDAY WILL REMAIN WELL BELOW
NORMAL. WE WILL SEE SOME DECENT THERMAL ADVECTION BETWEEN 1 TO 3KFT
LATE IN THE PERIOD OUT WEST...HOWEVER SOUTHEASTERLY LOW LEVEL FLOW
WILL CUT DOWN ON MIXING POTENTIAL AND INCREASING MID/HIGH CLOUDS
SHOULD LIMIT DAYTIME HEATING. THUS...HIGHS STILL SOME 10-15
DEGREES BELOW NORMAL THE HIGH POINT IN TEMPERATURES THIS PERIOD.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
A LOW PRESSURE SYSTEM WILL BE APPROACHING THE AREA FROM THE WEST
WHEN THE PERIOD STARTS. WAA PRECIPITATION ON THE LEADING EDGE OF
THE SYSTEM LOOKS PRETTY CERTAIN SATURDAY NIGHT...ESPECIALLY ACROSS
THE EASTERN CWA. THE SYSTEM SWINGS TO THE NORTHEAST ON SUNDAY AND
THERE LOOKS TO BE A BREAK IN THE PRECIPITATION SUNDAY NIGHT AND
MONDAY. ANOTHER SYSTEM THEN TRACKS ACROSS THE CENTRAL OR SOUTHERN
PLAINS DURING THE LATTER HALF OF THE PERIOD. THE GFS AND THE GEM
ARE CONSIDERABLY FURTHER SOUTH WITH THIS SYSTEM THAN THE
ECMWF...SO THERE IS A POSSIBILITY THAT WE WILL REMAIN DRY.
HOWEVER...AM NOT COMFORTABLE STRAYING THAT FAR FROM THE
ALLBLEND...SO WILL LEAVE A SMALL POP IN MONDAY NIGHT THROUGH
WEDNESDAY TO ACCOUNT FOR TRACKING DIFFERENCES.
WITH NEW SNOW COVER OVER MUCH OF THE CWA...DO NOT EXPECT TO SEE
TEMPERATURES REACH MEX GUIDANCE VALUES...AND WILL STAY ABOUT 5 TO
10 DEGREES BELOW IT FOR DAYTIME HIGHS. THIS WILL RESULT IN HIGH
TEMPERATURES MAINLY IN THE 30S AND 40S...WITH OVERNIGHT LOWS IN
THE 20S.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
THE TAF FOR KATY REMAINS NIL DUE TO THE ASOS EQUIPMENT BEING NON
FUNCTIONAL.
AN AREA OF SNOW WILL REMAIN OVER THE EASTERN CWA DURING THE
MORNING HOURS. MVFR CIGS AND VSBYS WILL OCCASIONALLY BECOME IFR
UNDER THE HEAVIER SNOW BANDS. THE SNOW WILL TAPER OFF AND COME TO
AN END BY THIS EVENING...BUT CIGS WILL BECOME IFR AND REMAIN THAT
WAY THROUGH THE OVERNIGHT HOURS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR BROWN-CLARK-
CODINGTON-DAY-DEUEL-GRANT-HAMLIN-MARSHALL-ROBERTS-SPINK.
WINTER WEATHER ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
EDMUNDS-FAULK-MCPHERSON.
MN...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR BIG STONE-
TRAVERSE.
&&
$$
UPDATE...MOHR
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
623 AM CDT THU APR 11 2013
.UPDATE...
MADE SOME ADJUSTMENTS TO THE WINTER WEATHER HEADLINES. DROPPED
LYMAN...HAND AND BUFFALO COUNTIES FROM THE WARNING AS SNOW LOOKS
TO JUST BE LIGHT THERE THROUGH THE REST OF THE MORNING. ADDED
BROWN AND MARSHALL COUNTIES TO THE WINTER STORM WARNING WITH
SEVERAL INCHES ALREADY FALLING OVERNIGHT AND MORE COMING THIS
MORNING. WILL LIKELY SEE TOTAL AMOUNTS IN EXCESS OF 6 INCHES IN
THOSE TWO COUNTIES.
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
LEFT EXIT REGION RESPONSIBLE FOR TRANSIENT BANDS OF MODERATE TO
HEAVY SNOWFALL THIS MORNING. HRRR DEPICTING CURRENT CONDITIONS
FAIRLY WELL...AND TRANSITIONS AREA OF HIGHEST RETURNS/BEST FORCING
NORTH OF THE CWA BY MID DAY. ASIDE FROM MINOR CONFIGURATION
CHANGES TO HEADLINES EARLIER...WILL STICK WITH CURRENT TIMING ON
END OF ACCUMULATING SNOWFALL. SREF PROBABILITIES STILL SUGGESTING
A FEW SPOTS TO TOP 8 INCHES IN FAR EASTERN SOUTH DAKOTA/MINNESOTA
COUNTIES.
WITH THE LAST OF THE SYNOPTIC SCALE SNOWFALL MOVING OUT...MODELS
STILL HINT AT A PERSISTENT STRATUS LAYER OVER THE REGION THROUGH
THE START OF THE WEEKEND. THE LACK OF THERMAL ADVECTION...AND H85
READINGS AROUND -7C OR A STANDARD DEVIATION BELOW CLIMO...SUGGEST
FORECAST TEMPERATURES THROUGH SATURDAY WILL REMAIN WELL BELOW
NORMAL. WE WILL SEE SOME DECENT THERMAL ADVECTION BETWEEN 1 TO 3KFT
LATE IN THE PERIOD OUT WEST...HOWEVER SOUTHEASTERLY LOW LEVEL FLOW
WILL CUT DOWN ON MIXING POTENTIAL AND INCREASING MID/HIGH CLOUDS
SHOULD LIMIT DAYTIME HEATING. THUS...HIGHS STILL SOME 10-15
DEGREES BELOW NORMAL THE HIGH POINT IN TEMPERATURES THIS PERIOD.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
A LOW PRESSURE SYSTEM WILL BE APPROACHING THE AREA FROM THE WEST
WHEN THE PERIOD STARTS. WAA PRECIPITATION ON THE LEADING EDGE OF
THE SYSTEM LOOKS PRETTY CERTAIN SATURDAY NIGHT...ESPECIALLY ACROSS
THE EASTERN CWA. THE SYSTEM SWINGS TO THE NORTHEAST ON SUNDAY AND
THERE LOOKS TO BE A BREAK IN THE PRECIPITATION SUNDAY NIGHT AND
MONDAY. ANOTHER SYSTEM THEN TRACKS ACROSS THE CENTRAL OR SOUTHERN
PLAINS DURING THE LATTER HALF OF THE PERIOD. THE GFS AND THE GEM
ARE CONSIDERABLY FURTHER SOUTH WITH THIS SYSTEM THAN THE
ECMWF...SO THERE IS A POSSIBILITY THAT WE WILL REMAIN DRY.
HOWEVER...AM NOT COMFORTABLE STRAYING THAT FAR FROM THE
ALLBLEND...SO WILL LEAVE A SMALL POP IN MONDAY NIGHT THROUGH
WEDNESDAY TO ACCOUNT FOR TRACKING DIFFERENCES.
WITH NEW SNOW COVER OVER MUCH OF THE CWA...DO NOT EXPECT TO SEE
TEMPERATURES REACH MEX GUIDANCE VALUES...AND WILL STAY ABOUT 5 TO
10 DEGREES BELOW IT FOR DAYTIME HIGHS. THIS WILL RESULT IN HIGH
TEMPERATURES MAINLY IN THE 30S AND 40S...WITH OVERNIGHT LOWS IN
THE 20S.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
THE TAF FOR KATY REMAINS NIL DUE TO THE ASOS EQUIPMENT BEING NON
FUNCTIONAL.
AN AREA OF SNOW WILL REMAIN OVER THE EASTERN CWA DURING THE
MORNING HOURS. MVFR CIGS AND VSBYS WILL OCCASIONALLY BECOME IFR
UNDER THE HEAVIER SNOW BANDS. THE SNOW WILL TAPER OFF AND COME TO
AN END BY THIS EVENING...BUT CIGS WILL BECOME IFR AND REMAIN THAT
WAY THROUGH THE OVERNIGHT HOURS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR BROWN-CLARK-
CODINGTON-DAY-DEUEL-GRANT-HAMLIN-MARSHALL-ROBERTS-SPINK.
WINTER WEATHER ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
EDMUNDS-FAULK-MCPHERSON.
MN...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR BIG STONE-
TRAVERSE.
&&
$$
UPDATE...PARKIN
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
400 AM CDT THU APR 11 2013
.SHORT TERM...THROUGH SATURDAY
LEFT EXIT REGION RESPONSIBLE FOR TRANSIENT BANDS OF MODERATE TO
HEAVY SNOWFALL THIS MORNING. HRRR DEPICTING CURRENT CONDITIONS
FAIRLY WELL...AND TRANSITIONS AREA OF HIGHEST RETURNS/BEST FORCING
NORTH OF THE CWA BY MID DAY. ASIDE FROM MINOR CONFIGURATION
CHANGES TO HEADLINES EARLIER...WILL STICK WITH CURRENT TIMING ON
END OF ACCUMULATING SNOWFALL. SREF PROBABILITIES STILL SUGGESTING
A FEW SPOTS TO TOP 8 INCHES IN FAR EASTERN SOUTH DAKOTA/MINNESOTA
COUNTIES.
WITH THE LAST OF THE SYNOPTIC SCALE SNOWFALL MOVING OUT...MODELS
STILL HINT AT A PERSISTENT STRATUS LAYER OVER THE REGION THROUGH
THE START OF THE WEEKEND. THE LACK OF THERMAL ADVECTION...AND H85
READINGS AROUND -7C OR A STANDARD DEVIATION BELOW CLIMO...SUGGEST
FORECAST TEMPERATURES THROUGH SATURDAY WILL REMAIN WELL BELOW
NORMAL. WE WILL SEE SOME DECENT THERMAL ADVECTION BETWEEN 1 TO 3KFT
LATE IN THE PERIOD OUT WEST...HOWEVER SOUTHEASTERLY LOW LEVEL FLOW
WILL CUT DOWN ON MIXING POTENTIAL AND INCREASING MID/HIGH CLOUDS
SHOULD LIMIT DAYTIME HEATING. THUS...HIGHS STILL SOME 10-15
DEGREES BELOW NORMAL THE HIGH POINT IN TEMPERATURES THIS PERIOD.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
A LOW PRESSURE SYSTEM WILL BE APPROACHING THE AREA FROM THE WEST
WHEN THE PERIOD STARTS. WAA PRECIPITATION ON THE LEADING EDGE OF
THE SYSTEM LOOKS PRETTY CERTAIN SATURDAY NIGHT...ESPECIALLY ACROSS
THE EASTERN CWA. THE SYSTEM SWINGS TO THE NORTHEAST ON SUNDAY AND
THERE LOOKS TO BE A BREAK IN THE PRECIPITATION SUNDAY NIGHT AND
MONDAY. ANOTHER SYSTEM THEN TRACKS ACROSS THE CENTRAL OR SOUTHERN
PLAINS DURING THE LATTER HALF OF THE PERIOD. THE GFS AND THE GEM
ARE CONSIDERABLY FURTHER SOUTH WITH THIS SYSTEM THAN THE
ECMWF...SO THERE IS A POSSIBILITY THAT WE WILL REMAIN DRY.
HOWEVER...AM NOT COMFORTABLE STRAYING THAT FAR FROM THE
ALLBLEND...SO WILL LEAVE A SMALL POP IN MONDAY NIGHT THROUGH
WEDNESDAY TO ACCOUNT FOR TRACKING DIFFERENCES.
WITH NEW SNOW COVER OVER MUCH OF THE CWA...DO NOT EXPECT TO SEE
TEMPERATURES REACH MEX GUIDANCE VALUES...AND WILL STAY ABOUT 5 TO
10 DEGREES BELOW IT FOR DAYTIME HIGHS. THIS WILL RESULT IN HIGH
TEMPERATURES MAINLY IN THE 30S AND 40S...WITH OVERNIGHT LOWS IN
THE 20S.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A BAND OF SNOW WILL CONTINUE TO MOVE NORTH/NORTHWEST INTO THE
REGION THROUGH THE NIGHT. LOWEST IFR VSBYS ARE EXPECTED AT
KATY/KABR OVERNIGHT WITH IMPROVEMENT THURSDAY MORNING. KPIR/KMBG
WILL ALSO SEE LOWERED VSBYS DUE TO SNOWFALL...MOSTLY IN THE MVFR
RANGE OVERNIGHT. CIGS WILL VARY WIDELY FROM IFR TO VFR DEPENDING
UPON THE INTENSITY OF SNOWFALL.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR CLARK-
CODINGTON-DAY-DEUEL-GRANT-HAMLIN-ROBERTS-SPINK.
WINTER WEATHER ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
EDMUNDS-FAULK-MCPHERSON.
WINTER STORM WARNING UNTIL 7 AM CDT THIS MORNING FOR BUFFALO-
HAND-LYMAN.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT THIS EVENING FOR BROWN-
MARSHALL.
MN...WINTER STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR BIG STONE-
TRAVERSE.
&&
$$
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1150 PM CDT WED APR 10 2013
.DISCUSSION...
SEE AVIATION FOR 06Z TAF ISSUANCE
&&
.AVIATION...
SHRA HAVE EXPANDED IN COVERAGE THIS EVENING WITH TSRA DEVELOPING
SOUTH OF INTERSTATE 10 AND EAST OF INTERSTATE 45. THIS CONVECTION
LIKELY DUE TO GOOD UPPER LEVEL SUPPORT PROVIDED BY DIFFLUENT FLOW
ALOFT AND ALSO BY SHORTWAVE DISTURBANCE ROTATING AROUND THE BASE
OF THE MAIN TROUGH ALONG THE RIO GRANDE. HAVE ADDED VCTS WITH
TEMPO TSRA FOR ALL SITES WITH THE EXCEPTION OF CLL AND UTS.
ACTIVITY SHOULD BEGIN TO DECREASE IN COVERAGE AND INTENSITY AFTER
09Z WITH CIGS IMPROVING THROUGH MID MORNING. FORECAST REASONING
FOR REMAINDER OF TAF VALID PERIOD REMAINS UNCHANGED WITH VFR
CONDITIONS DEVELOPING. 38
&&
.PREV DISCUSSION... /ISSUED 834 PM CDT WED APR 10 2013/
UPDATE...
EVENING FORECAST UPDATE.
DISCUSSION...
COLD FRONT HAS PUSHED INTO THE UPPER TX COASTAL WATERS THIS
EVENING BUT HAS NOT MADE A WHOLE LOT OF PROGRESS. FRONT HAS SLOWED
WITH IT BECOMING MORE NNE/SSW ORIENTED. STARTING TO GET SOME
ELEVATED SHOWERS OVER THE FRONT MAINLY EAST OF A CONROE...KATY TO
BAY CITY LINE. WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH AND JET
STREAK COMING THROUGH MEX INTO THE RIO GRANDE VALLEY/S TX. THIS
MAY ENHANCE ELEVATED CONVECTION OVER SE TX DURING THE EARLY
MORNING HOURS. OVERALL THINK MODELS ARE ON TRACK BUT THAT
GFS/ECMWF ARE OVER DOING PRECIP AMOUNTS AND COVERAGE. THINK THERE
WILL BE SCATTERED ACTIVITY BUT PRECIP AMOUNTS WILL DEPEND ON
REDEVELOPMENT OF CELLS AND TRAINING. DECIDED TO KEEP POPS AROUND
50 PERCENT BUT COULD SEE ADJUSTMENT FOR HIGHER POPS. THE HRRR HAS
BEEN DOING FAIRLY WELL WITH ITS CONVECTIVE TRENDS SO FAR AND THINK
WITH IT DEVELOPING CONVECTION AFTER 07Z TONIGHT...COASTAL AREAS
COULD SEE SOME DECENT RAIN. WILL CONTINUE TO MONITOR TRENDS IN
CONVECTION BUT MAY NEED TO WATCH FOR HOW MUCH CONVECTION FORMS
AFTER MIDNIGHT WITH THE APPROACHING SHORTWAVE.
39
PREV DISCUSSION... /ISSUED 640 PM CDT WED APR 10 2013/
DISCUSSION...
SEE AVIATION FOR 00Z TAF ISSUANCE
AVIATION...
SURFACE FRONT HAS PUSHED THROUGH ALL SOUTHEAST TEXAS TERMINALS
THIS EVENING. WIND GUSTS ARE PICKING UP ACROSS THE NORTHERN HALF
OF THE REGION AS THE UPPER LEVEL FRONT ARRIVES AND THESE SHOULD
CONTINUE TO OVERSPREAD THE REST OF THE REGION WITHIN THE NEXT HOUR
OR SO.
MAIN CONCERN THIS EVENING REMAINS EXTENT OF IFR CIGS AND POTENTIAL
OVERNIGHT SHRA ACTIVITY. SEVERAL OF THE MODELS REDEVELOP
PRECIPITATION BEHIND THE FRONT ACROSS AREAS ALONG AND SOUTH OF
INTERSTATE 10 AND EAST OF US 59...AFFECTING ALL SITES EXCEPT CLL.
WILL KEEP MENTION OF VCSH THROUGH 09Z FOR SOUTHERN SITES BUT AM
EXPECTING ACTIVITY TO WANE OR PUSH EAST OF THE REGION BY THEN. ONE
MODEL DOES SUPPORT SOME STRONGER SHRA OR PERHAPS ISOLATED TSRA
AROUND 09Z DUE TO STRONG UPPER LEVEL DIFFLUENCE BUT AM NOT
CONFIDENT IN THIS SOLUTION AND WILL KEEP MENTION OF TSRA OUT OF
THE TAFS FOR NOW. AS PCPN BEGINS TO END EXPECT IFR CIGS TO BEGIN
IMPROVING...FIRST AT CLL AND THEN ACROSS THE REST OF THE REGION
BETWEEN 09-12Z THURSDAY. AM EXPECTING SCT250 OR SKC BY
MIDAFTERNOON THURSDAY WITH WINDS BECOMING NORTHEAST AFTER 11/00Z
AS BROAD SURFACE HIGH PRESSURE SHIFTS INTO THE MISSISSIPPI RIVER
VALLEY. 38
PREV DISCUSSION... /ISSUED 313 PM CDT WED APR 10 2013/
DISCUSSION...
AT 19Z...A WELL DEFINED COLD FRONT EXTENDED FROM TEXARKANA TO
HOUSTON TO JUST EAST OF PALACIOS. TEMPERATURES ARE ALMOST 25
DEGREES COOLER BEHIND THE FRONT. THE FRONT WILL CONTINUE TO MOVE
EAST THROUGH THE EVENING AND SHOULD CLEAR ALL OF SE TX BY 23Z (6
PM). AREA HAS REMAINED STRONGLY CAPPED AND SEVERE STORMS DID NOT
DEVELOP AND NONE ARE EXPECTED THIS EVENING. STILL SOME SMALL
CONCERN THAT ELEVATED CONVECTION COULD PRODUCE SOME HAIL AS THE
UPPER TROUGH NEARS LATER TONIGHT. THE UPPER TROUGH WILL PROVIDE
ADDITIONAL LIFT AND SE TX WILL LIE IN A RIGHT REAR QUAD OF THE JET
LATER TONIGHT. THE NAM 12 WHICH HAS PERFORMED RATHER WELL TODAY
ENDS THE RAINFALL BY 06Z WHILE THE GFS/ECMWF AND RAP MODELS ALL
WANT TO REDEVELOP PRECIP MAINLY ALONG AND EAST OF THE US HWY 59
CORRIDOR THROUGH 12Z THURSDAY. FCST SOUNDINGS SHOW SATURATION
BENEATH A STRONG CAP WITH TOTAL TOTALS IN THE LOWER 50S AND PW
VALUES AROUND 1.2 INCHES. FEEL THE POSITION OF THE UPPER JET IS
THE KEY TO WHETHER RAIN REDEVELOPS THIS EVENING AND MODELS DIFFER
A BIT WITH HOW QUICKLY THE UPPER TROUGH PUSHES EAST AND THIS WILL
DETERMINE WHETHER RAIN DEVELOPS OVER LAND OR OVER THE GULF. WATER
VAPOR IMAGERY SUPPORTS THE POSITION OF THE UPPER TROUGH ADVERTISED
BY THE ECMWF. HAVE LEANED TOWARD A BLEND OF HPC...ECMWF...GFS AND
RAP GUIDANCE FOR TONIGHT. RAIN WILL LIKELY BE ENDING AROUND 12Z
THURSDAY AND SKIES WILL QUICKLY CLEAR. TEMPS SHOULD REBOUND NICELY
UNDER FULL SUN DESPITE A VERY COOL START TO THE DAY. RELATIVELY
QUIET WEATHER FRI/SAT AS HIGH PRESSURE DRIFTS ACROSS THE SOUTHERN
PLAINS.
A WELL DEFINED S/WV WILL PUSH ACROSS TEXAS ON SUNDAY. THE GFS IS
QUITE AGGRESSIVE WITH THE MOISTURE RETURN ON SUNDAY. THE ECMWF
FOCUSES MORE OF THE PRECIP OFFSHORE YET IT`S SOLUTION ALSO OFFERS
UP A STRONG S/WV TROUGH MOVING ACROSS THE STATE. THE CANADIAN
SUPPORTS THE WETTER GFS SOLUTION SO WILL ADD POPS FOR SUNDAY. JET
DYNAMICS DON`T LOOK FAVORABLE SO WILL ONLY GO WITH SLIGHT RAIN
CHANCES FOR NOW.
UPPER LEVEL RIDGING OVER THE GULF OF MEXICO WILL AMPLIFY AND
EXPAND INTO SOUTHEAST TEXAS EARLY NEXT WEEK. FCST SOUNDINGS
SUPPORT MAX TEMPS IN THE UPPER 80S. BUMPED MAX TEMPS UP A FEW
DEGREES FOR MON-WED. ANOTHER FRONT EXPECTED TOWARD THE END OF NEXT
WEEK. THE POSITION OF THE UPPER RIDGE FAVORS THE SLOWER ECMWF SO
LEANED TOWARD THE SLOWER FROPA FOR THE END OF NEXT WEEK. 43
MARINE...
THE PRIMARY NEAR TERM ISSUES WILL BE THE RECENT COASTAL RUN UP AND
THE MODEST CHANCE FOR LINGERING OVERNIGHT PRECIPITATION. CURRENT
WATER LEVELS ARE AROUND A FOOT ABOVE NORMAL PER THIS RECENT NEAR 20
KNOT SOUTHEASTERLY FETCH...A NEAR SUNSET COLD FRONTAL PASSAGE WILL
VEER WINDS AROUND TO NORTHWEST AT SIMILAR MAGNITUDES. VARIOUS HIGHER
RESOLUTION WEATHER FORECAST MODELS ARE INDICATING MORE STEADY
RAINFALL OVER OUR (MORE EASTERN) WATERS TONIGHT AND LASTING THROUGH
SUNRISE THURSDAY. THE HIGHER CHANCE FOR POST-FRONTAL RAIN CAN BE
ATTRIBUTED TO THE FAVORABLE POSITIONING OF THE JET STREAM WITH THE
SLOWER EASTERN-ADVANCEMENT OF THE UPPER LEVEL TROUGH. EARLY THURSDAY
SCA LEVEL OFFSHORE WINDS WILL WEAKEN TO BELOW SCEC BY THE EVENING...BAYS
SHOULD BE BELOW SCEC BY THE EARLY AFTERNOON. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 42 68 46 76 52 / 20 10 0 0 0
HOUSTON (IAH) 47 70 49 77 53 / 50 10 0 0 0
GALVESTON (GLS) 51 72 60 76 63 / 50 20 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM 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...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
924 PM MDT FRI APR 12 2013
.UPDATE...
ISSUED AT 915 PM MDT FRI APR 12 2013
INHERITED FORECAST IN GOOD SHAPE TONIGHT. LATEST HRRR CONTINUES TO
POINT TO AT LEAST SOME PATCHY FOG/LOW STRATUS DEVELOPMENT ACROSS
THE EASTERN PLAINS TONIGHT. IN FACT...LATEST OBSERVATIONS ALONG
THE I25 CORRIDOR AS WELL AS IN THE KIMBALL VICINITY ARE ALREADY
RECORDING CLOUDS DECKS BELOW 3000 FEET. THIS LINES UP WELL WITH
THE 11-3.9 SATELLITE FOG PRODUCT. IN A RECENT UPDATE...INCREASED
CLOUDS AS WELL AS ADDED MENTION OF FOG TO MUCH OF THE EASTERN
PLAINS. HAVE ALSO REMOVED FOG MENTION IN THE LARAMIE VALLEY AS
WIND SPEEDS ARE ANTICIPATED TO REMAIN TOO HIGH FOR ITS
DEVELOPMENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 331 PM MDT FRI APR 12 2013
PLENTY OF SHORT TERM CHALLENGES WITH THIS FORECAST PACKAGE.
CURRENTLY...UPPER LEVEL DISTURBANCE THAT BROUGHT THE MODERATE SNOW
TO PLATTE AND SOUTHERN CONVERSE COUNTY THIS MORNING IS NOW PUSHING
OFF INTO WESTERN NEBRASKA THIS AFTERNOON. STILL QUITE A BIT OF
RETURNS ON THE CHEYENNE RADAR...EVEN SOME LIGHTNING STRIKES OVER
NORTHERN AND NORTHEASTERN COLORADO...BUT FOR THE MOST
PART...WIDESPREAD SNOW HAS COME TO AN END AS TEMPERATURES HAVE
CLIMBED INTO THE UPPER 30S. WENT AHEAD AND CANCELLED THE SNOW
ADVISORY WE ISSUED THIS MORNING AS UPPER SHORT WAVE MOVES EAST.
REMAINING SHOWER ACTIVITY SHOULD DISSIPATE OUT WITH LOSS OF
DAYTIME HEATING AFTER SUNSET.
ATTENTION TURNS TO WINDS TONIGHT. UPPER RIDGE AXIS LOOKS TO PASS
OVER THE AREA BY MIDNIGHT TONIGHT. UP UNTIL THAT POINT...MAY SEE
SOME EVENING FOG AS WE HAVE SEEN THE PAST FEW EVENING. WEST TO
SOUTHWESTERLY WINDS BEGIN TO INCREASE SIGNIFICANTLY TOWARDS 12Z
SATURDAY WITH GFS FORECASTING 50KTS OUT BY ALBANY COUNTY. THIS IN
RESPONSE TO A FRONTAL SYSTEM MOVING INTO NORTHWEST WYOMING. BY 18Z
SATURDAY...WE SEE THE UPPER LEVEL JET...ON THE ORDER OF 110KTS
PUSHING INTO CENTRAL WYOMING. OUR WIND PRONE AREAS SHOULD BE CLOSE
TO HIGH WIND WARNING CRITERIA BY THAT TIME WITH BREEZY WINDS
ELSEWHERE. WILL GO AHEAD AND ISSUE A HIGH WIND WATCH FOR SATURDAY
AFTERNOON FOR THESE AREAS. LATER SHIFTS WILL NEED TO WATCH OTHER
AREAS AS LATEST MOS GUIDANCE IS SHOWING PRETTY STRONG WINDS AT
RAWLINS AND LARAMIE. CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME TO
ISSUE A WATCH FOR THOSE AREAS.
FRONT THEN LOOKS TO MOVE THROUGH SOUTHERN WYOMING BY SATURDAY
EVENING. MODELS DO DEPICT SOME PRETTY GOOD QPF OVER THE SNOWY AND
SIERRA MADRE RANGES AT THIS TIME AND WE WILL PROBABLY NEED A SNOW
ADVISORY FOR THOSE LOCATIONS SATURDAY NIGHT INTO SUNDAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 331 PM MDT FRI APR 12 2013
A STRONG UPPER LOW WILL SHIFT EAST OF THE FORECAST AREA ON
SUNDAY...WITH A COLD FRONT DROPPING SOUTH THROUGH THE AREA SUNDAY
EVENING. AHEAD OF THE FRONT...THE SFC PRESSURE GRADIENT WILL REMAIN
FAIRLY STRONG AS A SFC LOW DEEPENS AHEAD OF THE MAIN UPPER LOW
OVER THE NORTHERN PLAINS. SO EXPECTING MODERATE TO STRONG WESTERLY
WINDS ON SUNDAY WITH THE PRESSURE GRADIENT IN PLACE AHEAD OF THE
COLD FRONT. SUBSIDENCE IN THE WAKE OF THE DEPARTING SYSTEM ALONG
WITH THE DOWNSLOPE WINDS SHOULD KEEP CONDITIONS MOSTLY DRY...WITH
MAYBE A FEW LIGHT SNOW SHOWERS ALONG THE FRONT AS IT DROPS SOUTH
IN THE EVENING IN ADDITION TO THE WESTERN SLOPES OF THE MOUNTAINS
DUE TO UPSLOPE FORCING. THE FRONT LOOKS TO STALL OVER THE
MOUNTAINS...WITH NORTHEAST UPSLOPE FLOW STRENGTHENING SUNDAY NIGHT.
THE NEXT UPPER SYSTEM DIGGING INTO THE FOUR CORNERS REGION ON MONDAY
WILL INDUCE STRONG SFC PRESSURE FALLS OVER THE GREAT BASIN ON SUNDAY
NIGHT AND MONDAY. SO ON TOP OF THE POST-FRONTAL UPSLOPE FLOW
DEVELOPING ACROSS THE CWA...THE INCREASING PRESSURE GRADIENT FORCING
DUE TO THE INTENSIFYING LOW WILL DEEPEN THE UPSLOPE COMPONENT
EVEN FURTHER. IN ADDITION...STILL LOOKING AT MIDLEVEL ENERGY
EJECTING OUT AHEAD OF THE DEEPENING UPPER LOW AND MOVING OVER THE
FORECAST AREA MONDAY AND TUESDAY. ALL IN ALL...STILL LOOKING AT
THE POTENTIAL FOR YET ANOTHER PERIOD FOR MODERATE TO HEAVY SNOW
BEGINNING LATE SUNDAY NIGHT AND CONTINUING THROUGH EARLY
WEDNESDAY. WILL CONTINUE TO EMPHASIZE THIS SYSTEM IN THE HWO ALONG
WITH CONTINUED TREND FOR INCREASED POPS...ESPECIALLY ALONG THE
LARAMIE RANGE...CHEYENNE RIDGE...AND WESTERN MOUNTAINS.
MODELS DIFFER QUITE A BIT WITH MOVING THIS SYSTEM TO THE EAST
WEDNESDAY NIGHT AND THURSDAY. THE ECMWF IS SIGNIFICANTLY SLOWER THAN
THE GFS AND GEM MODELS...MEANING SNOW COULD LINGER LONGER THROUGH
WEDNESDAY NIGHT AND NORTHWEST WINDS WILL REMAIN STRONGER. HOWEVER...THE
CONSENSUS SHOWS THE IMPACTS FROM THE STORM WILL DIMINISH LATE ON
WEDNESDAY...WITH NORTHWEST FLOW RETURNING TO THE CWA FOR THURSDAY.
TEMPERATURES THROUGH THE PERIOD WILL TREND MILD ON SUNDAY...THEN
MUCH COLDER MONDAY THROUGH WEDNESDAY BEHIND THE COLD FRONT AND AS
THE UPPER LOW MOVES SLOWLY OVERHEAD. TEMPS WILL SLOWLY WARM FOR
THURSDAY BUT WILL DEPEND HEAVILY ON THE SNOWPACK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON)
ISSUED AT 615 PM MDT FRI APR 12 2013
CLOUDS CONTINUE TO DISSIPATE ACROSS AREA TERMINALS WITH VFR
CONDITIONS PREVAILING EARLY THIS EVENING. DO HAVE A CONCERN ABOUT
MVFR OR EVEN IFR CIGS/VSBYS AT KCYS/KBFF AFTER 06Z OR SO IN
ANTICIPATION OF PATCHY FOG DEVELOPMENT. CONDITIONS WILL IMPROVE AT
THESE LOCATIONS SHORTLY AFTER SUNRISE ON SATURDAY. EXPECT CLOUD
DECKS TO SLOWLY DESCEND AT KRWL AND KLAR AFTER 18Z IN ADVANCE OF
THE NEXT WEAK UPPER LEVEL DISTURBANCE SET TO MOVE THROUGH SATURDAY
NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 331 PM MDT FRI APR 12 2013
NO FIRE WEATHER CONCERNS AS CURRENT SNOW PACK CONTINUES TO MELT
AND FUELS ARE MOIST. WE DO HAVE A PRETTY WIDESPREAD WIND EVENT
SATURDAY AS A COLD FRONT APPROACHES WESTERN WYOMING. SOUTHWEST TO
WEST WINDS GUSTING IN EXCESS OF 50 MPH LOOK LIKELY FOR A LARGE
PART OF SOUTHEAST WYOMING SATURDAY. AFTERNOON HUMIDITIES SATURDAY
AND SUNDAY ONLY EXPECTED TO FALL INTO THE UPPER 20S AND LOW 30S.
UNSETTLED WEATHER RETURNS TO THE AREA THE BEGINNING OF NEXT WEEK
WITH ACCUMULATING SNOWS RETURNING TO MUCH OF THE AREA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR WYZ106-110-116-117.
NE...NONE.
&&
$$
UPDATE...HAHN
SHORT TERM...CLAYCOMB
LONG TERM...RJM
AVIATION...HAHN
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
958 PM EDT FRI APR 12 2013
.SYNOPSIS...
LOW PRESSURE WILL TRACK WELL SOUTH OF THE REGION OVERNIGHT...
THEN EXIT EAST OF NOVA SCOTIA SATURDAY. UNSETTLED CONDITIONS WILL
PERSIST SUNDAY. HIGH PRESSURE WILL CROSS THE REGION MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
940 PM: SOME PRELIM SNOW REPORTS INDICATE SO FAR THE CURRENT FCST
IS ON TRACK...WITH MANY PLACES ALREADY RECEIVING 2 TO 3 INCHES
INCLUDING 2 INCHES HERE AT WFO CAR. SN RATIOS FOR LOCATIONS
CARRYING ALL SN ACROSS THE N HLF OF THE FA HAVE BEEN FAIRLY HIGH
(LIKE 12:1 AT CAR) EVEN AT LOWER TRRN PLACES WITH SFC TEMPS AT
FREEZING...PERHAPS DUE TO GROUND TEMPS REMAINING COLD DUE COLD DAY
AND SPCLY NGT TM TEMPS. OTHER THAN MINOR RE-DISTRIBUTIONS OF 6 HRLY
SNFL BETWEEN WHAT WAS OBSVD BETWEEN 18-24Z AND WHAT IS XPCTD OVR
THE 00-06Z AND 06-12Z PDS AND INCORPORATING LATEST OBSVD HRLY
TEMPS...NO CHGS WERE MADE TO THE LAST UPDATE. SNFL ACROSS SPCLY
THE N PTN OF THE FA STILL LOOKS UNCERTAIN AFT THE NEXT COUPLE OF
HRS...BUT MOST LOCATIONS SHOULD REACH AND EXCEED THE LOW END OF
FCST STORM TOTAL SNFL BASED ON LATEST REPORTS.
630 PM UPDATE: OUTSIDE OF ADDING TERRAIN AFFECTS TO 6 HRLY AND
RESULTANT EVENT TOTAL SNFL BASED ON THE CORRESPONDING 6 HRLY QPF
TOTALS FROM THE LAST FCST UPDATE...NO SIG CHGS TO THE GOING FCST
XCPT FOR SOME REDUCTION OF SNFL IN THE INTERIOR DOWNEAST ROW
OF ZONES...DUE TO A RAPID EXIT OF THE INITIAL OVRRNG BAND THRU
THE SRN HLF OF THE FA (SEE NEXT PARAGRAPH).
SAYING THIS...HOWEVER...THERE ARE CONCERNS...WITH NEAR TERM MODEL
GUIDANCE NOT IN MUCH AGREEMENT WITH THE EVOLUTION OF THIS EVENT.
SOME MODELS LIKE THE 18Z GFS AND 12Z CANGEM RUNS...BACKED UP BY
THE LATEST HRLY HRRR MODEL OUTPUT DO NOT GIVE MUCH IN ADDITIONAL
EQUIV QPF TO THE REGION...SPCLY NE ME AFT THE INITIAL OVRRNG BAND
OF PRECIP SLIDES E OF THE FA ERLY THIS EVE...AND THIS BAND APPEARS
TO BE MOVG OUT FASTER THAN ORIGINALLY ANTICIPATED. OTHER MODEL
GUIDANCE...SPCLY ENS MEAN GUIDANCE LIKE THE GFS AND SREF ENSMNS
DO BRING MODEST 0.10-0.15 INCHES OF LIQ EQUIV FOR BOTH THE 00-06Z
AND 06-12Z PDS OVRNGT. NOT SURE ATTM WHAT THE ACTUAL OUTCOME WILL
BE...BUT WE MAY BE LUCKY TO REACH LOWER END VALUES OF CURRENT
FCSTD TOTAL SNOWFALL RANGES BY SAT AFTN.
ORGNL DISC: A COMPLEX FORECAST THROUGH THE NEAR TERM WITH
PRECIPITATION TYPE AND SNOW/SLEET ACCUMULATIONS THE BIGGEST
CHALLENGES. WINTER WEATHER ADVISORIES REMAIN IN PLACE THROUGH
TONIGHT AND INTO SATURDAY MORNING.
PRIMARY LOW PRESSURE WILL CONTINUE TO SLIDE NORTHEAST ACROSS THE
GREAT LAKES TONIGHT AND SATURDAY. MEANWHILE, A SECONDARY SYSTEM
CURRENTLY DEVELOPING OVER NORTHERN VIRGINIA WILL MOVE OFF SHORE AND
TREK TOWARDS NOVA SCOTIA. PRECIPITATION ASSOCIATED WITH WARM
ADVECTION AHEAD OF THE PRIMARY SYSTEM IS CURRENTLY SPREADING INTO
SOUTHWESTERN PORTIONS OF OUR FORECAST AREA, AND IT WILL CONTINUE TO
PROGRESS EASTWARD THROUGH THIS EVENING. UPSTREAM OBS REPORTING
PLENTY OF MIXED PRECIPITATION, SO THE WARM LAYER ALOFT IS CLEARLY
MAKING ITS WAY INTO THE REGION. AS SUCH, WE STILL EXPECT A
SNOW/SLEET/RAIN MIX TO FALL ACROSS CENTRAL AND DOWNEAST MAINE THIS
EVENING AND OVERNIGHT. A FEW OF THE HIGHER ELEVATION SITES OUT WEST
HAVE BEEN REPORTING FREEZING RAIN FROM TIME TO TIME, SO DID
INTRODUCE A SLIGHT CHANCE OF FREEZING RAIN IN OUR HIGHER ELEVATIONS
IN THE GREENVILLE/DOVER-FOXCROFT AREA. NORTHERN MAINE WILL REMAIN
ALL SNOW FOR MUCH OF THE EVENT, WITH PERHAPS JUST A SHORT PERIOD AT
THE ONSET OF PRECIPITATION. AS ALWAYS WITH MIXED PRECIPITATION,
ACCUMULATIONS WILL BE A CHALLENGE ACROSS CENTRAL AND DOWNEAST MAINE.
EVEN IN THE NORTH ACCUMULATIONS MAY BE TEMPERED A BIT BY TODAY`S
MILD TEMPERATURES. EXPECTED SNOW AMOUNTS HAVE NOT CHANGED MUCH (SEE
DETAILS BELOW) WITH 4-7 INCHES ACROSS NORTHERN AND CENTRAL AREAS AND
2-4 IN THE INTERIOR DOWNEAST. LITTLE TO NO SNOW WILL ACCUMULATE
ALONG THE COAST AS OVERNIGHT TEMPS WILL HOVER IN THE MID 30S.
FOR TOMORROW, PRECIPITATION WILL BEGIN TO SLOWLY WIND DOWN FROM
SOUTH TO NORTH AS LOW PRESSURE PULLS AWAY FROM THE REGION. HOWEVER,
PRECIPITATION CHANCES WILL CONTINUE, ESPECIALLY OVER THE NORTH, AS
THE UPPER LEVEL PART OF THE SYSTEM APPROACHES FROM THE WEST.
TEMPERATURES WILL WARM UP INTO THE UPPER 30S TO LOWER 40S IN MOST
LOCATIONS, SO DO EXPECT LINGER SNOW SHOWERS WILL CHANGE OVER TO RAIN
DURING THE AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
SURFACE TROFFING WILL REMAIN ACROSS THE REGION SATURDAY NIGHT
BETWEEN LOW PRESSURE EAST OF THE MARITIMES AND A WEAKENING LOW
ACROSS QUEBEC PROVINCE. AN UPPER LOW WILL ALSO APPROACH FROM THE
WEST SATURDAY NIGHT. EVENING RAIN/SNOW SHOWERS WILL TRANSITION TO
SNOW SHOWERS ACROSS THE FORECAST AREA...MOST EXTENSIVE ACROSS THE
NORTH AND MOUNTAINS. SNOW ACCUMULATIONS ACROSS THE NORTH AND
MOUNTAINS SATURDAY NIGHT ARE EXPECTED TO BE AN INCH OR LESS...WITH
ANY ACCUMULATIONS DOWNEAST LESS THAN AN INCH. SURFACE TROFFING
PERSISTS ACROSS THE REGION SUNDAY WHILE THE UPPER LOW CROSSES THE
FORECAST AREA. CONDITIONS WILL REMAIN UNSETTLED ACROSS THE
FORECAST AREA SUNDAY WITH A CHANCE OF MORNING RAIN/SNOW SHOWERS
AND AFTERNOON RAIN SHOWERS. HIGH PRESSURE THEN BEGINS TO BUILD
EAST SUNDAY NIGHT WITH DECREASING CLOUDS. HIGH PRESSURE CROSSES
THE REGION MONDAY WITH GENERALLY PARTLY SUNNY SKIES...THOUGH CLOUD
COVER COULD BEGIN TO INCREASE ACROSS NORTHWEST AREAS LATE. HIGH
PRESSURE THEN MOVES EAST MONDAY NIGHT WHILE A WARM FRONT
APPROACHES LATE. CLOUD COVER WILL INCREASE ACROSS THE REGION
MONDAY NIGHT WITH A CHANCE OF RAIN/SNOW SHOWERS LATE PARTICULARLY
ACROSS NORTHERN AND NORTHWESTERN AREAS. TEMPERATURES WILL BE AT
SLIGHTLY BELOW NORMAL LEVELS SUNDAY...WITH NEAR NORMAL LEVEL
TEMPERATURES MONDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LOW PRESSURE WILL TRACK WELL NORTHWEST OF THE STATE TUESDAY WITH A COLD
FRONT CROSSING THE REGION TUESDAY NIGHT. THERE WILL BE A CHANCE
FOR SHOWERS IN ADVANCE OF AND WITH THE PASSAGE OF THE FRONT
TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL BUILD BACK IN FOR
WEDNESDAY UNDER A MIX OF SUN AND CLOUDS. THE NEXT SYSTEM LOOKS TO
ARRIVE BY THURSDAY BRINGING ANOTHER CHANCE FOR RAIN AND SHOWERS.
TEMPERATURES WILL BE NEAR IF NOT A LITTLE ABOVE MID APRIL AVERAGES
THROUGH THE LONG RANGE.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: ANY SITES WITH VFR WILL QUICKLY DROP TO MVFR AND THEN
IFR BY THIS EVENING AS WIDESPREAD WINTRY PRECIPITATION SPREADS
OVER THE REGION. THE NORTHERN TERMINALS WILL REMAIN ALL SNOW
THROUGH SATURDAY MORNING WHILE KBGR AND KBHB WILL SEE A MIX OF
RAIN/SNOW/SLEET. PRECIPITATION WILL SLOWLY WIND DOWN FROM SOUTH TO
NORTH SATURDAY, TAPERING TO RAIN AND SNOW SHOWERS BY AFTERNOON.
MOST SITES WILL IMPROVE TO MVFR BY 18Z, BUT THE NORTHERN SITES
COULD STILL SEE OCCASIONAL IFR CEILINGS THROUGH THE DAY.
SHORT TERM: OCCASIONAL MVFR CONDITIONS WILL OCCUR ACROSS THE
REGION SATURDAY NIGHT THROUGH SUNDAY. GENERALLY VFR CONDITIONS ARE
EXPECTED ACROSS THE REGION SUNDAY NIGHT INTO EARLY MONDAY NIGHT.
MVFR CONDITIONS WILL THEN BEGIN TO DEVELOP LATER MONDAY NIGHT WITH
A PERIOD OF IFR LIKELY TUESDAY BEFORE IMPROVEMENT TO VFR OCCURS
WEDNESDAY.
&&
.MARINE...
NEAR TERM: THE SMALL CRAFT ADVISORY REMAINS IN PLACE THROUGH
SATURDAY. LOW PRESSURE WILL MOVE TO THE SOUTH OF THE GULF OF MAINE
TONIGHT AND THEN PUSH INTO THE MARITIMES. WINDS WILL INCREASE TO
15 TO 25 KT WITH GUSTS TO 30 KNOTS THROUGH THIS EVENING AND REMAIN
SO OVERNIGHT. WHILE THE WINDS WILL SUBSIDE SATURDAY, WAVES WILL
STAY ABOVE 5 FT.
SHORT TERM: SMALL CRAFT ADVISORY LEVEL SEAS ARE POSSIBLE SATURDAY
EVENING. OTHERWISE...WINDS/SEAS ARE EXPECTED TO BE BELOW SMALL
CRAFT ADVISORY LEVELS SATURDAY NIGHT THROUGH MUCH OF MONDAY NIGHT.
WINDS/SEAS COULD THEN BEGIN TO INCREASE LATER MONDAY NIGHT
WITH SCA CONDITIONS POSSIBLE TUESDAY. VISIBILITIES COULD BE LOCALLY
REDUCED IN ANY RAIN/SNOW SHOWERS SATURDAY NIGHT INTO SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 11 AM EDT SATURDAY FOR
MEZ001>006-010.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT SATURDAY FOR MEZ011-
015>017-031-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORCROSS
LONG TERM...FITZSIMMONS
AVIATION...VJN/NORCROSS
MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
700 PM EDT FRI APR 12 2013
.SYNOPSIS...
LOW PRESSURE WILL TRACK WELL SOUTH OF THE REGION OVERNIGHT...
THEN EXIT EAST OF NOVA SCOTIA SATURDAY. UNSETTLED CONDITIONS WILL
PERSIST SUNDAY. HIGH PRESSURE WILL CROSS THE REGION MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
630 PM UPDATE: OUTSIDE OF ADDING TERRAIN AFFECTS TO 6 HRLY AND
RESULTANT EVENT TOTAL SNFL BASED ON THE CORRESPONDING 6 HRLY QPF
TOTALS FROM THE LAST FCST UPDATE...NO SIG CHGS TO THE GOING FCST
XCPT FOR SOME REDUCTION OF SNFL IN THE INTERIOR DOWNEAST ROW
OF ZONES...DUE TO A RAPID EXIT OF THE INITIAL OVRRNG BAND THRU
THE SRN HLF OF THE FA (SEE NEXT PARAGRAPH).
SAYING THIS...HOWEVER...THERE ARE CONCERNS...WITH NEAR TERM MODEL
GUIDANCE NOT IN MUCH AGREEMENT WITH THE EVOLUTION OF THIS EVENT.
SOME MODELS LIKE THE 18Z GFS AND 12Z CANGEM RUNS...BACKED UP BY
THE LATEST HRLY HRRR MODEL OUTPUT DO NOT GIVE MUCH IN ADDITIONAL
EQUIV QPF TO THE REGION...SPCLY NE ME AFT THE INITIAL OVRRNG BAND
OF PRECIP SLIDES E OF THE FA ERLY THIS EVE...AND THIS BAND APPEARS
TO BE MOVG OUT FASTER THAN ORIGINALLY ANTICIPATED. OTHER MODEL
GUIDANCE...SPCLY ENS MEAN GUIDANCE LIKE THE GFS AND SREF ENSMNS
DO BRING MODEST 0.10-0.15 INCHES OF LIQ EQUIV FOR BOTH THE 00-06Z
AND 06-12Z PDS OVRNGT. NOT SURE ATTM WHAT THE ACTUAL OUTCOME WILL
BE...BUT WE MAY BE LUCKY TO REACH LOWER END VALUES OF CURRENT
FCSTD TOTAL SNOWFALL RANGES BY SAT AFTN.
ORGNL DISC: A COMPLEX FORECAST THROUGH THE NEAR TERM WITH
PRECIPITATION TYPE AND SNOW/SLEET ACCUMULATIONS THE BIGGEST
CHALLENGES. WINTER WEATHER ADVISORIES REMAIN IN PLACE THROUGH
TONIGHT AND INTO SATURDAY MORNING.
PRIMARY LOW PRESSURE WILL CONTINUE TO SLIDE NORTHEAST ACROSS THE
GREAT LAKES TONIGHT AND SATURDAY. MEANWHILE, A SECONDARY SYSTEM
CURRENTLY DEVELOPING OVER NORTHERN VIRGINIA WILL MOVE OFF SHORE AND
TREK TOWARDS NOVA SCOTIA. PRECIPITATION ASSOCIATED WITH WARM
ADVECTION AHEAD OF THE PRIMARY SYSTEM IS CURRENTLY SPREADING INTO
SOUTHWESTERN PORTIONS OF OUR FORECAST AREA, AND IT WILL CONTINUE TO
PROGRESS EASTWARD THROUGH THIS EVENING. UPSTREAM OBS REPORTING
PLENTY OF MIXED PRECIPITATION, SO THE WARM LAYER ALOFT IS CLEARLY
MAKING ITS WAY INTO THE REGION. AS SUCH, WE STILL EXPECT A
SNOW/SLEET/RAIN MIX TO FALL ACROSS CENTRAL AND DOWNEAST MAINE THIS
EVENING AND OVERNIGHT. A FEW OF THE HIGHER ELEVATION SITES OUT WEST
HAVE BEEN REPORTING FREEZING RAIN FROM TIME TO TIME, SO DID
INTRODUCE A SLIGHT CHANCE OF FREEZING RAIN IN OUR HIGHER ELEVATIONS
IN THE GREENVILLE/DOVER-FOXCROFT AREA. NORTHERN MAINE WILL REMAIN
ALL SNOW FOR MUCH OF THE EVENT, WITH PERHAPS JUST A SHORT PERIOD AT
THE ONSET OF PRECIPITATION. AS ALWAYS WITH MIXED PRECIPITATION,
ACCUMULATIONS WILL BE A CHALLENGE ACROSS CENTRAL AND DOWNEAST MAINE.
EVEN IN THE NORTH ACCUMULATIONS MAY BE TEMPERED A BIT BY TODAY`S
MILD TEMPERATURES. EXPECTED SNOW AMOUNTS HAVE NOT CHANGED MUCH (SEE
DETAILS BELOW) WITH 4-7 INCHES ACROSS NORTHERN AND CENTRAL AREAS AND
2-4 IN THE INTERIOR DOWNEAST. LITTLE TO NO SNOW WILL ACCUMULATE
ALONG THE COAST AS OVERNIGHT TEMPS WILL HOVER IN THE MID 30S.
FOR TOMORROW, PRECIPITATION WILL BEGIN TO SLOWLY WIND DOWN FROM
SOUTH TO NORTH AS LOW PRESSURE PULLS AWAY FROM THE REGION. HOWEVER,
PRECIPITATION CHANCES WILL CONTINUE, ESPECIALLY OVER THE NORTH, AS
THE UPPER LEVEL PART OF THE SYSTEM APPROACHES FROM THE WEST.
TEMPERATURES WILL WARM UP INTO THE UPPER 30S TO LOWER 40S IN MOST
LOCATIONS, SO DO EXPECT LINGER SNOW SHOWERS WILL CHANGE OVER TO RAIN
DURING THE AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
SURFACE TROFFING WILL REMAIN ACROSS THE REGION SATURDAY NIGHT
BETWEEN LOW PRESSURE EAST OF THE MARITIMES AND A WEAKENING LOW
ACROSS QUEBEC PROVINCE. AN UPPER LOW WILL ALSO APPROACH FROM THE
WEST SATURDAY NIGHT. EVENING RAIN/SNOW SHOWERS WILL TRANSITION TO
SNOW SHOWERS ACROSS THE FORECAST AREA...MOST EXTENSIVE ACROSS THE
NORTH AND MOUNTAINS. SNOW ACCUMULATIONS ACROSS THE NORTH AND
MOUNTAINS SATURDAY NIGHT ARE EXPECTED TO BE AN INCH OR LESS...WITH
ANY ACCUMULATIONS DOWNEAST LESS THAN AN INCH. SURFACE TROFFING
PERSISTS ACROSS THE REGION SUNDAY WHILE THE UPPER LOW CROSSES THE
FORECAST AREA. CONDITIONS WILL REMAIN UNSETTLED ACROSS THE
FORECAST AREA SUNDAY WITH A CHANCE OF MORNING RAIN/SNOW SHOWERS
AND AFTERNOON RAIN SHOWERS. HIGH PRESSURE THEN BEGINS TO BUILD
EAST SUNDAY NIGHT WITH DECREASING CLOUDS. HIGH PRESSURE CROSSES
THE REGION MONDAY WITH GENERALLY PARTLY SUNNY SKIES...THOUGH CLOUD
COVER COULD BEGIN TO INCREASE ACROSS NORTHWEST AREAS LATE. HIGH
PRESSURE THEN MOVES EAST MONDAY NIGHT WHILE A WARM FRONT
APPROACHES LATE. CLOUD COVER WILL INCREASE ACROSS THE REGION
MONDAY NIGHT WITH A CHANCE OF RAIN/SNOW SHOWERS LATE PARTICULARLY
ACROSS NORTHERN AND NORTHWESTERN AREAS. TEMPERATURES WILL BE AT
SLIGHTLY BELOW NORMAL LEVELS SUNDAY...WITH NEAR NORMAL LEVEL
TEMPERATURES MONDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LOW PRESSURE WILL TRACK WELL NORTHWEST OF THE STATE TUESDAY WITH A COLD
FRONT CROSSING THE REGION TUESDAY NIGHT. THERE WILL BE A CHANCE
FOR SHOWERS IN ADVANCE OF AND WITH THE PASSAGE OF THE FRONT
TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL BUILD BACK IN FOR
WEDNESDAY UNDER A MIX OF SUN AND CLOUDS. THE NEXT SYSTEM LOOKS TO
ARRIVE BY THURSDAY BRINGING ANOTHER CHANCE FOR RAIN AND SHOWERS.
TEMPERATURES WILL BE NEAR IF NOT A LITTLE ABOVE MID APRIL AVERAGES
THROUGH THE LONG RANGE.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: ANY SITES WITH VFR WILL QUICKLY DROP TO MVFR AND THEN
IFR BY THIS EVENING AS WIDESPREAD WINTRY PRECIPITATION SPREADS
OVER THE REGION. THE NORTHERN TERMINALS WILL REMAIN ALL SNOW
THROUGH SATURDAY MORNING WHILE KBGR AND KBHB WILL SEE A MIX OF
RAIN/SNOW/SLEET. PRECIPITATION WILL SLOWLY WIND DOWN FROM SOUTH TO
NORTH SATURDAY, TAPERING TO RAIN AND SNOW SHOWERS BY AFTERNOON.
MOST SITES WILL IMPROVE TO MVFR BY 18Z, BUT THE NORTHERN SITES
COULD STILL SEE OCCASIONAL IFR CEILINGS THROUGH THE DAY.
SHORT TERM: OCCASIONAL MVFR CONDITIONS WILL OCCUR ACROSS THE
REGION SATURDAY NIGHT THROUGH SUNDAY. GENERALLY VFR CONDITIONS ARE
EXPECTED ACROSS THE REGION SUNDAY NIGHT INTO EARLY MONDAY NIGHT.
MVFR CONDITIONS WILL THEN BEGIN TO DEVELOP LATER MONDAY NIGHT WITH
A PERIOD OF IFR LIKELY TUESDAY BEFORE IMPROVEMENT TO VFR OCCURS
WEDNESDAY.
&&
.MARINE...
NEAR TERM: THE SMALL CRAFT ADVISORY REMAINS IN PLACE THROUGH
SATURDAY. LOW PRESSURE WILL MOVE TO THE SOUTH OF THE GULF OF MAINE
TONIGHT AND THEN PUSH INTO THE MARITIMES. WINDS WILL INCREASE TO
15 TO 25 KT WITH GUSTS TO 30 KNOTS THROUGH THIS EVENING AND REMAIN
SO OVERNIGHT. WHILE THE WINDS WILL SUBSIDE SATURDAY, WAVES WILL
STAY ABOVE 5 FT.
SHORT TERM: SMALL CRAFT ADVISORY LEVEL SEAS ARE POSSIBLE SATURDAY
EVENING. OTHERWISE...WINDS/SEAS ARE EXPECTED TO BE BELOW SMALL
CRAFT ADVISORY LEVELS SATURDAY NIGHT THROUGH MUCH OF MONDAY NIGHT.
WINDS/SEAS COULD THEN BEGIN TO INCREASE LATER MONDAY NIGHT
WITH SCA CONDITIONS POSSIBLE TUESDAY. VISIBILITIES COULD BE LOCALLY
REDUCED IN ANY RAIN/SNOW SHOWERS SATURDAY NIGHT INTO SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 11 AM EDT SATURDAY FOR
MEZ001>006-010.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT SATURDAY FOR MEZ011-
015>017-031-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORCROSS
LONG TERM...FITZSIMMONS
AVIATION...VJN/NORCROSS
MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
201 AM EDT SAT APR 13 2013
.UPDATE...
ISSUED AT 1034 PM EDT FRI APR 12 2013
NO CHANGES WERE MADE TO WINTER WX ADVY OVER THE W AND PORTION OF THE
NCNTRL EVEN THOUGH SNOW OVERALL THIS EVENING DOES NOT SUPPORT
MAINTAINING HEADLINES. AS WINDS BACK AROUND MORE NORTHERLY DURING
THE NIGHT AND WE HEAD INTO THE MORE FAVORABLE PART OF THE DIURNAL
CYCLE FOR LAKE EFFECT PROCESSES...THERE SHOULD BE SOME INCREASE IN
LAKE ENHANCED SNOW. IT ALSO APPEARS THAT INSTEAD OF GRADUALLY
BACKING WINDS...THE BACKING WINDS MAY OCCUR MORE AS A SFC TROF
PASSAGE AS HIGHER RES MODEL GUIDANCE INDICATES. THIS WOULD IMPROVE
CONVERGENCE AND OVERALL SNOW COVERAGE/INTENSITY LATE TONIGHT THRU
MID MORNING SAT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN
WI WITH SHORTWAVE SPOKES INTO SRN UPPER MI AND WRN LAKE SUPERIOR.
WIDESPREAD LIGHT SNOW (VSBY IN THE 1-4SM RANGE) STILL PREVAILED
ACROSS MUCH OF UPPER MI WITH THE FAVORABLE UPPER LEVEL DIV AND
700-300 MB QVECTOR CONV TO THE NORTH OF THE LOW. AT THE SFC...LOW
PRES WAS LOCATED OVER NW LOWER MI NEAR TVC WITH A TROUGH EXTENDING
TO THE EAST TO LAKE ONTARIO. WITH THE SFC-850 MB TROUGH EDGING
CLOSER TO THE AREA...THE ENE LOW LEVEL FLOW HAD DIMINISHED. EVEN
WITH 850 MB TEMPS DOWN TO AROUND -11C...RADAR SHOWED ONLY MINIMAL IF
ANY LAKE ENHANCEMENT INTO N CNTRL UPPER MI.
EXPECT LIGHT SNOW ASSOCIATED WITH THE MID LEVEL LOW TO PERSIST THIS
EVENING BUT WITH ACCUMULATIONS OF LESS THAN AN INCH. WITH THE LOW
LEVEL TROUGH AXIS SHIFTING TO NEAR E UPPER MI...LOW LEVEL CONV FOR
LAKE ENHANCED SNOW WILL BE LESS FAVORABLE THIS EVENING. HOWEVER...AS
THE TROUGH SHIFTS TO THE EAST AND WINDS BACK MORE NRLY AND STRENGTHEN
OVERNIGHT INTO SATURDAY MORNING...LAKE ENHANCED SNOW IS EXPECTED TO
BECOME HEAVIER OVER THE WEST AND THEN SHIFT INTO N CNTRL UPPER MI
LATE TONIGHT INTO SATURDAY MORNING. EVEN WITH ONLY MARGINAL 850 MB
TEMPS NEAR -12C AND LAKE INDUCED CAPES TO NEAR 300 J/KG...ABUNDANT
850-500 MB MOISTURE AND CYCLONIC LOW LEVEL FLOW WILL FAVOR AT LEAST
LIGHT TO MODERATE SNOW. SNOW/WATER RATIOS SHOULD ALSO BECOME MORE
FAVORABLE WITH SIGNIFICANT UPWARD MOTION IN THE 850-750 MB DGZ LAYER.
EVEN WITH THE SNOW TAPERING OFF FOR A TIME TONIGHT...THE ADVISORIES
OVER THE NW HALF WERE EXTENDED INTO SATURDAY WITH HIGHER SNOWFALL
RATES AGAIN DEVELOPING. ADDITIONAL AMOUNTS FROM 00Z-18Z SHOULD STILL
REMAIN IN THE 2 TO 6 INCH RANGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
THE LONG RANGE LOOKS TO FEATURE AN WX ACTIVE PATTERN WITH BLO NORMAL
TEMPS OVERALL AS MEAN UPR TROF OVER CENTRAL NAMERICA LINGERS. MAIN
FOCUS WL BE ON NEXT LO PRES DISTURBANCE PROGGED TO IMPACT THE CWA
LATE SUN THRU SUN NGT.
SAT NGT...SHRTWV RDG AXIS BTWN DEPARTING/WEAKENING CLOSED LO OVER SE
CANADA AND NEXT SHRTWV/SFC LO MOVING INTO THE NRN PLAINS IS FCST TO
BLD INTO THE GRT LKS. WITH ARRIVAL OF SFC HI PRES RDG/DRYING ALF
UNDER THE RISING HGTS...LINGERING -SHSN UNDER MORE PERSISTENT CYC NW
FLOW/DEEPER MSTR/H85 TEMPS AS LO AS -10C IN THE EVNG OVER THE
NCENTRAL AND E WL END AND GIVE WAY TO AT LEAST PARTIAL CLRG.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY ON SUN WITH SFC HI PRES
RDG SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/SW FLOW BTWN THE
DEPARTING HI AND NEXT SHRTWV/SFC LO MOVING THRU THE NRN PLAINS AND
TOWARD MN LATE ON SUN OVERSPREADS UPR MI. AS UPR DVGC/BAND OF H5-7
FGEN AHEAD OF ATTENDANT WARM FNT MOVES IN AFT 18Z...EXPECT PCPN TO
OVERSPREAD THE CWA BY 00Z MON. PTYPE WL BE A CONCERN AT THE ONSET OF
THE PCPN EVENT SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED
TEMP PROFILE WL AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN
SHOW ELEVATED WARM LYR ABV SUB ZERO NEAR SFC LYR. IN FACT...THESE
FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH SOME ZR FOR A
TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER TERRAIN OF THE W
HALF. BUT THESE SDNGS ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE
AFTN FOLLOWING AT LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL
DRY AIR...EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB
TEMPS. BUT THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES
CENTER OVER ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME
THIS LATE IN THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT.
HIER MOS TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 50-60KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH H85
TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NEGATIVELY TILTED
APPEARANCE OF SHRTWV/VERY DIFFLUENT SW FLOW ALF/MSTR SURGE WITH PWAT
FCST UP TO 1 INCH SUN EVNG...OR 200 PCT OF NORMAL...INDICATE QPF
NEARING 1 INCH IS ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF
LINGERING SN PILES MAY CAUSE SOME PONDING OF WATER. CONSIDERED
ADDING A CHC OF ELEVATED TS UNDER THE MOST IMPRESSIVE
MOISTENING/AXIS OF H85 LLJ...BUT FCST SDNGS SHOW H85-5 LAPSE RATES
NOT QUITE MOIST ADIABATIC. ARRIVAL OF DRY SLOT SUN NGT WL DIMINISH
POPS SW-NE AFTER THE EVNG.
MON...DRY SLOT ON THE SRN FLANK OF SHRTWV/SFC LO TRACKING ENEWD THRU
SRN ONTARIO WL END ANY LINGERING PCPN OVER THE E AND SCNTRL
ASSOCIATED WITH DEPARTING WARM CONVEYOR BELT. THE GFS IS MOST
AGGRESSIVE AT SHOWING SOME DEEPER MSTR/PCPN ON THE SE FLANK OF THE
UPR LO IMPACTING THE WRN ZNS...BUT BULK OF GUIDANCE INDICATES DEEPER
MSTR/PCPN WL REMAIN IN MN CLOSER TO LINGERING LO PRES TROF ON SW
FLANK OF LO DEPARTING TO THE NE. EXPECT AT LEAST PARTIAL SUNSHINE...
WHICH SHOULD BOOST MAX TEMPS INTO THE 40S AT MOST PLACES WITH H85
TEMPS FCST JUST A COUPLE DEGREES BLO 0C.
EXTENDED...DRYING/LLVL ACYC FLOW UNDER SLOWLY RISING HGTS BTWN
DEPARTING LO AND DEEPENING TROF IN THE ROCKIES WL BRING DRY WX AND
SEASONABLE TEMPS FOR MON NGT THRU TUE NGT. AS LO PRES LIFTS NEWD OUT
OF THE WRN TROF AND TOWARD THE GRT LKS ON WED INTO THU...ANOTHER
SGNFT MIXED PCPN EVENT APPEARS LIKELY. IF THE WELL CLUSTERED 00Z
ECMWF...CNDN...AND UKMET VERIFY...THE PTYPE WOULD BE MAINLY SN OVER
THE W HALF OF THE CWA WITH WARNING SN TOTALS LIKELY. THE 00Z/06Z/12Z
GFS ON THE OTHER HAND SHOWS A MUCH WEAKER LO TRACKING FARTHER TO THE
S AND MUCH LESS PCPN IMPACTING MAINLY THE SE HALF OF UPR MI. ALL
THESE SCENARIOS ARE WITHIN THE SPREAD SHOWN BY THE 00Z GFS ENSEMBLE
MEMBERS. COLDER AIR WITH SHSN WL FOLLOW ON FRI AS THE 00Z ECMWF
SHOWS H85 TEMPS TUMBLING TO -15C UNDER CYC NW FLOW LEFT IN THE WAKE
OF DEPARTING LO PRES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 158 AM EDT SAT APR 13 2013
SOME CLEARING AND LIGHTENING OF WINDS OVER THE PAST FEW HOURS HAS
LED TO SOME GROUND FOG AND VLIFR CONDITIONS AT SAW (AND ALSO ESC). AS
THE SURFACE TROUGH MOVES THROUGH IN THE NEXT FEW HRS...EXPECT THIS TO
SUBSIDE.
WITH MID/UPPER LEVEL LOW DRIFTING ACROSS THE AREA...SCT/NMRS -SHSN
WILL CONTINUE INTO THE MORNING HRS. AT KIWD...FAVORABLE UPSLOPE
NORTHERLY WINDS OFF THE LAKE SHOULD RESULT IN PREVAILING IFR
CONDITIONS. WOULDN`T BE SURPRISED TO SEE BRIEF LIFR AT TIMES AS WELL
AS MVFR. AT KCMX...EXPECT CONDITIONS VARYING BTWN MVFR AND IFR. IFR
MAY BE MORE PERSISTENT LATER IN THE NIGHT INTO THE MORNING AS SFC
TROF DRIFTS ACROSS THE AREA. AT KSAW...MVFR CONDITIONS SHOULD
PREVAIL FOR MUCH OF THE NIGHT. AS SFC TROF DROPS ACROSS THE AREA
LATE...CONDITIONS SHOULD FALL TO IFR. AT ALL SITES...EXPECT
IMPROVEMENT TO MVFR LATE THIS MORNING...AND -SHSN SHOULD END BY LATE
AFTN. MVFR CIGS MAY CLEAR OUT OF KIWD THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 445 PM EDT FRI APR 12 2013
AS LOW PRESSURE OVER LOWER MICHIGAN SLIDES TO THE EAST TONIGHT AND
SATURDAY...WINDS WILL DIMINISH. THIS OCCURS...WINDS WILL GRADUALLY
SHIFT TO THE NORTH-NORTHWEST THROUGH SATURDAY AS A LINGERING SURFACE
TROUGH ROTATES THROUGH LAKE SUPERIOR. ENE GALES LATE THIS AFTERNOON
WILL DIMINISH TO 20 TO 30 KT WINDS TONIGHT AND INTO THE 15 TO 25 KT
RANGE SATURDAY.
WINDS ON SAT NIGHT WILL TURN LIGHT WITH THE ARRIVAL OF A HI PRES
RIDGE. EXPECT INCREASING E WINDS UP TO 25 TO 30 KTS VEERING TO THE
SE ON SUN INTO SUN NIGHT AHEAD OF A LO PRES SYSTEM MOVING FROM THE
NORTHERN PLAINS TOWARD MN. NOT OUT OF THE QUESTION THERE COULD BE
SOME GALES DURING THIS EVENT. AS THIS LO PASSES THRU ONTARIO ON
MON/MON NIGHT AND THE PRES GRADIENT OVER LAKE SUP DIMINISHES...THE
WINDS WILL SUBSIDE WHILE VEERING TO THE S AND THEN W INTO TUE. EXPECT
THE WINDS TO SHIFT TO THE N BY WED AS HI PRES BUILDS IN CENTRAL
CANADA AND ANOTHER LO PRES SYSTEM MOVES NE THRU THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MIZ004-
005.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING
FOR MIZ002-009.
WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR MIZ001-
003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...JLB
LONG TERM...KC
AVIATION...MRD/ROLFSON
MARINE...JLB/KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1035 PM EDT FRI APR 12 2013
.UPDATE...
ISSUED AT 1034 PM EDT FRI APR 12 2013
NO CHANGES WERE MADE TO WINTER WX ADVY OVER THE W AND PORTION OF THE
NCNTRL EVEN THOUGH SNOW OVERALL THIS EVENING DOES NOT SUPPORT
MAINTAINING HEADLINES. AS WINDS BACK AROUND MORE NORTHERLY DURING
THE NIGHT AND WE HEAD INTO THE MORE FAVORABLE PART OF THE DIURNAL
CYCLE FOR LAKE EFFECT PROCESSES...THERE SHOULD BE SOME INCREASE IN
LAKE ENHANCED SNOW. IT ALSO APPEARS THAT INSTEAD OF GRADUALLY
BACKING WINDS...THE BACKING WINDS MAY OCCUR MORE AS A SFC TROF
PASSAGE AS HIGHER RES MODEL GUIDANCE INDICATES. THIS WOULD IMPROVE
CONVERGENCE AND OVERALL SNOW COVERAGE/INTENSITY LATE TONIGHT THRU
MID MORNING SAT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN
WI WITH SHORTWAVE SPOKES INTO SRN UPPER MI AND WRN LAKE SUPERIOR.
WIDESPREAD LIGHT SNOW (VSBY IN THE 1-4SM RANGE) STILL PREVAILED
ACROSS MUCH OF UPPER MI WITH THE FAVORABLE UPPER LEVEL DIV AND
700-300 MB QVECTOR CONV TO THE NORTH OF THE LOW. AT THE SFC...LOW
PRES WAS LOCATED OVER NW LOWER MI NEAR TVC WITH A TROUGH EXTENDING
TO THE EAST TO LAKE ONTARIO. WITH THE SFC-850 MB TROUGH EDGING
CLOSER TO THE AREA...THE ENE LOW LEVEL FLOW HAD DIMINISHED. EVEN
WITH 850 MB TEMPS DOWN TO AROUND -11C...RADAR SHOWED ONLY MINIMAL IF
ANY LAKE ENHANCEMENT INTO N CNTRL UPPER MI.
EXPECT LIGHT SNOW ASSOCIATED WITH THE MID LEVEL LOW TO PERSIST THIS
EVENING BUT WITH ACCUMULATIONS OF LESS THAN AN INCH. WITH THE LOW
LEVEL TROUGH AXIS SHIFTING TO NEAR E UPPER MI...LOW LEVEL CONV FOR
LAKE ENHANCED SNOW WILL BE LESS FAVORABLE THIS EVENING. HOWEVER...AS
THE TROUGH SHIFTS TO THE EAST AND WINDS BACK MORE NRLY AND STRENGTHEN
OVERNIGHT INTO SATURDAY MORNING...LAKE ENHANCED SNOW IS EXPECTED TO
BECOME HEAVIER OVER THE WEST AND THEN SHIFT INTO N CNTRL UPPER MI
LATE TONIGHT INTO SATURDAY MORNING. EVEN WITH ONLY MARGINAL 850 MB
TEMPS NEAR -12C AND LAKE INDUCED CAPES TO NEAR 300 J/KG...ABUNDANT
850-500 MB MOISTURE AND CYCLONIC LOW LEVEL FLOW WILL FAVOR AT LEAST
LIGHT TO MODERATE SNOW. SNOW/WATER RATIOS SHOULD ALSO BECOME MORE
FAVORABLE WITH SIGNIFICANT UPWARD MOTION IN THE 850-750 MB DGZ LAYER.
EVEN WITH THE SNOW TAPERING OFF FOR A TIME TONIGHT...THE ADVISORIES
OVER THE NW HALF WERE EXTENDED INTO SATURDAY WITH HIGHER SNOWFALL
RATES AGAIN DEVELOPING. ADDITIONAL AMOUNTS FROM 00Z-18Z SHOULD STILL
REMAIN IN THE 2 TO 6 INCH RANGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 PM EDT FRI APR 12 2013
THE LONG RANGE LOOKS TO FEATURE AN WX ACTIVE PATTERN WITH BLO NORMAL
TEMPS OVERALL AS MEAN UPR TROF OVER CENTRAL NAMERICA LINGERS. MAIN
FOCUS WL BE ON NEXT LO PRES DISTURBANCE PROGGED TO IMPACT THE CWA
LATE SUN THRU SUN NGT.
SAT NGT...SHRTWV RDG AXIS BTWN DEPARTING/WEAKENING CLOSED LO OVER SE
CANADA AND NEXT SHRTWV/SFC LO MOVING INTO THE NRN PLAINS IS FCST TO
BLD INTO THE GRT LKS. WITH ARRIVAL OF SFC HI PRES RDG/DRYING ALF
UNDER THE RISING HGTS...LINGERING -SHSN UNDER MORE PERSISTENT CYC NW
FLOW/DEEPER MSTR/H85 TEMPS AS LO AS -10C IN THE EVNG OVER THE
NCENTRAL AND E WL END AND GIVE WAY TO AT LEAST PARTIAL CLRG.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY ON SUN WITH SFC HI PRES
RDG SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/SW FLOW BTWN THE
DEPARTING HI AND NEXT SHRTWV/SFC LO MOVING THRU THE NRN PLAINS AND
TOWARD MN LATE ON SUN OVERSPREADS UPR MI. AS UPR DVGC/BAND OF H5-7
FGEN AHEAD OF ATTENDANT WARM FNT MOVES IN AFT 18Z...EXPECT PCPN TO
OVERSPREAD THE CWA BY 00Z MON. PTYPE WL BE A CONCERN AT THE ONSET OF
THE PCPN EVENT SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED
TEMP PROFILE WL AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN
SHOW ELEVATED WARM LYR ABV SUB ZERO NEAR SFC LYR. IN FACT...THESE
FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH SOME ZR FOR A
TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER TERRAIN OF THE W
HALF. BUT THESE SDNGS ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE
AFTN FOLLOWING AT LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL
DRY AIR...EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB
TEMPS. BUT THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES
CENTER OVER ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME
THIS LATE IN THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT.
HIER MOS TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 50-60KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH H85
TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NEGATIVELY TILTED
APPEARANCE OF SHRTWV/VERY DIFFLUENT SW FLOW ALF/MSTR SURGE WITH PWAT
FCST UP TO 1 INCH SUN EVNG...OR 200 PCT OF NORMAL...INDICATE QPF
NEARING 1 INCH IS ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF
LINGERING SN PILES MAY CAUSE SOME PONDING OF WATER. CONSIDERED
ADDING A CHC OF ELEVATED TS UNDER THE MOST IMPRESSIVE
MOISTENING/AXIS OF H85 LLJ...BUT FCST SDNGS SHOW H85-5 LAPSE RATES
NOT QUITE MOIST ADIABATIC. ARRIVAL OF DRY SLOT SUN NGT WL DIMINISH
POPS SW-NE AFTER THE EVNG.
MON...DRY SLOT ON THE SRN FLANK OF SHRTWV/SFC LO TRACKING ENEWD THRU
SRN ONTARIO WL END ANY LINGERING PCPN OVER THE E AND SCNTRL
ASSOCIATED WITH DEPARTING WARM CONVEYOR BELT. THE GFS IS MOST
AGGRESSIVE AT SHOWING SOME DEEPER MSTR/PCPN ON THE SE FLANK OF THE
UPR LO IMPACTING THE WRN ZNS...BUT BULK OF GUIDANCE INDICATES DEEPER
MSTR/PCPN WL REMAIN IN MN CLOSER TO LINGERING LO PRES TROF ON SW
FLANK OF LO DEPARTING TO THE NE. EXPECT AT LEAST PARTIAL SUNSHINE...
WHICH SHOULD BOOST MAX TEMPS INTO THE 40S AT MOST PLACES WITH H85
TEMPS FCST JUST A COUPLE DEGREES BLO 0C.
EXTENDED...DRYING/LLVL ACYC FLOW UNDER SLOWLY RISING HGTS BTWN
DEPARTING LO AND DEEPENING TROF IN THE ROCKIES WL BRING DRY WX AND
SEASONABLE TEMPS FOR MON NGT THRU TUE NGT. AS LO PRES LIFTS NEWD OUT
OF THE WRN TROF AND TOWARD THE GRT LKS ON WED INTO THU...ANOTHER
SGNFT MIXED PCPN EVENT APPEARS LIKELY. IF THE WELL CLUSTERED 00Z
ECMWF...CNDN...AND UKMET VERIFY...THE PTYPE WOULD BE MAINLY SN OVER
THE W HALF OF THE CWA WITH WARNING SN TOTALS LIKELY. THE 00Z/06Z/12Z
GFS ON THE OTHER HAND SHOWS A MUCH WEAKER LO TRACKING FARTHER TO THE
S AND MUCH LESS PCPN IMPACTING MAINLY THE SE HALF OF UPR MI. ALL
THESE SCENARIOS ARE WITHIN THE SPREAD SHOWN BY THE 00Z GFS ENSEMBLE
MEMBERS. COLDER AIR WITH SHSN WL FOLLOW ON FRI AS THE 00Z ECMWF
SHOWS H85 TEMPS TUMBLING TO -15C UNDER CYC NW FLOW LEFT IN THE WAKE
OF DEPARTING LO PRES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 758 PM EDT FRI APR 12 2013
WITH MID/UPPER LEVEL LOW DRIFTING ACROSS THE AREA...SCT/NMRS -SHSN
WILL CONTINUE TONIGHT INTO SAT MORNING. AT KIWD...EXPECT CONDITIONS
VARYING BTWN IFR/MVFR THIS EVENING WITH A GENERAL TREND TOWARD
PREVAILING IFR BY LATE EVENING AS WINDS BACK MORE NORTHERLY OVER THE
LAKE...INCREASING UPSLOPE INTO KIWD. WOULDN`T BE SURPRISED TO SEE
BRIEF LIFR AT TIMES. AT KCMX...IFR SHOULD PREVAIL THRU THE NIGHT
WITH SOME PERIODS OF LIFR. LIFR MAY BE MORE FREQUENT FOR A PERIOD
LATE EVENING/OVERNIGHT AS SFC TROF DRIFTS ACROSS THE AREA. AT
KSAW...EXPECT MVFR CONDITIONS SHOULD PREVAIL FOR MUCH OF THE NIGHT.
AS SFC TROF DROPS ACROSS THE AREA LATE TONIGHT...CONDITIONS SHOULD
FALL TO IFR. AT ALL SITES...EXPECT IMPROVEMENT TO MVFR LATE SAT
MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 445 PM EDT FRI APR 12 2013
AS LOW PRESSURE OVER LOWER MICHIGAN SLIDES TO THE EAST TONIGHT AND
SATURDAY...WINDS WILL DIMINISH. THIS OCCURS...WINDS WILL GRADUALLY
SHIFT TO THE NORTH-NORTHWEST THROUGH SATURDAY AS A LINGERING SURFACE
TROUGH ROTATES THROUGH LAKE SUPERIOR. ENE GALES LATE THIS AFTERNOON
WILL DIMINISH TO 20 TO 30 KT WINDS TONIGHT AND INTO THE 15 TO 25 KT
RANGE SATURDAY.
WINDS ON SAT NIGHT WILL TURN LIGHT WITH THE ARRIVAL OF A HI PRES
RIDGE. EXPECT INCREASING E WINDS UP TO 25 TO 30 KTS VEERING TO THE
SE ON SUN INTO SUN NIGHT AHEAD OF A LO PRES SYSTEM MOVING FROM THE
NORTHERN PLAINS TOWARD MN. NOT OUT OF THE QUESTION THERE COULD BE
SOME GALES DURING THIS EVENT. AS THIS LO PASSES THRU ONTARIO ON
MON/MON NIGHT AND THE PRES GRADIENT OVER LAKE SUP DIMINISHES...THE
WINDS WILL SUBSIDE WHILE VEERING TO THE S AND THEN W INTO TUE. EXPECT
THE WINDS TO SHIFT TO THE N BY WED AS HI PRES BUILDS IN CENTRAL
CANADA AND ANOTHER LO PRES SYSTEM MOVES NE THRU THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EDT SATURDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY UNTIL 11 AM EDT SATURDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...JLB
LONG TERM...KC
AVIATION...ROLFSON
MARINE...JLB/KC
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1006 PM CDT FRI APR 12 2013
.UPDATE...
CENTER OF UPPER LOW IS LOCATED JUST SOUTH OF MARQUETTE MI LATE
THIS EVENING..AND IS CONTINUING TO PULL OFF TO THE EAST. HOWEVER..
BENT-BACK AXIS OF DEFORMATION AND LOWER HEIGHTS EXTENDS WEST FROM
THE LOW CENTER ACROSS NRN MINNESOTA..AND THE EASTWARD PROGRESS IS
BEING HAMPERED BY THE AMPLIFYING S/W TROF SLIDING EWD ACROSS NRN
IOWA AT THE MOMENT. THUS..WEAK FORCING FOR ASCENT IS LIKELY TO
PERSIST FOR EVEN LONGER THAN PREVIOUSLY THOUGH OVERNIGHT..WITH
LIGHT SNOW PERSISTING ACROSS MUCH OF EASTERN MN AND NW WISCONSIN.
WHILE PRECIP RATES WILL BE MUCH LESS THAN OBSERVED EARLIER
TODAY..HIGHER SNOW-LIQUID RATIOS AS COLUMN COOLS MAY STILL RESULT
IN ANOTHER FEW INCHES IN SOME OF THE FAVORED TERRAIN AREAS OF THE
BAYFIELD PENINSULA AND GOGEBIC RANGE WHERE NE WINDS WILL STILL
PROVIDE SOME ADDED MOISTURE FROM LK SUPERIOR.
WINDS HAVE DIMINISHED MARKEDLY FROM THIS AFTERNOON..AND WITH THE
CESSATION OF STRONGER WINDS AND HEAVIER SNOWFALL RATES OVER THE
ARROWHEAD..WE HAVE ALLOWED THE WINTER STORM WARNING TO EXPIRE AS
SCHEDULED AT 10 PM. HOWEVER..WE HELD ON TO WARNINGS/ADVISORIES FOR
THE SNOWBELT AREAS OF NW WISCONSIN.
OTHERWISE..WINDS SHOULD CONTINUE TO DIMINISH OVERNIGHT ALONG WITH
CLOUDY SKIES PERSISTING. UPDATES TO GRIDS AND ALL ASSOCIATED TEXT
PRODUCTS HAVE BEEN SENT.
&&
.PREV DISCUSSION... /ISSUED 709 PM CDT FRI APR 12 2013/
AVIATION...00Z TAF ISSUANCE...
CENTER OF UPPER LOW IS MOVING INTO THE UPPER PENINSULA OF MICHIGAN
EARLY THIS EVENING. HOWEVER..DEFORMATION ZONE CONTINUES TO EXTEND
WESTWARD FROM THE UPPER LOW CENTER ACROSS MUCH OF NORTHEAST
MINNESOTA AND NORTHWEST WISCONSIN..AND FORCING FOR ASCENT IN THIS
ZONE WILL CONTINUE TO PRODUCE RATHER WIDESPREAD LIGHT SNOW ACROSS
ALL TERMINAL SITES FOR THE FIRST FEW HOURS OF THIS TAF
PERIOD..ALONG WITH WIDESPREAD MVFR CEILINGS. LIGHT SNOW SHOULD
DIMINISH FROM WEST TO EAST BETWEEN 03-08Z AT MOST TERMINALS.
HOWEVER..PRECIP MAY HANG ON A LITTLE LONGER AT KDLH/KHYR IN CLOSER
PROXIMITY TO UPPER LOW AND DEFORMATION AXIS.
MAINLY MVFR CEILINGS ARE EXPECTED TO PERSIST OVERNIGHT AND SAT
MORNING..WITH A SLOW LIFTING OF CLOUD BASES DURING THE DAY
SATURDAY. HOWEVER..COMBINATION OF STEEP LOW LEVEL LAPSE
RATES/RESIDUAL BOUNDARY LAYER MOISTURE AND LIMITED HEATING
TOMORROW MAY RESULT IN THE DEVELOPMENT OF BROKEN MVFR/VFR
CUMULUS/STRATOCUMULUS DECK BEGINNING AROUND MIDDAY ALONG WITH
PERIODIC SNOW SHOWERS IN THE AFTERNOON.
PREV DISCUSSION... /ISSUED 345 PM CDT FRI APR 12 2013/
SHORT TERM...THROUGH SATURDAY.
WATER VAPOR SHOWS THE UPPER LOW MOVING NORTHEAST ACROSS NORTHERN
WISCONSIN THIS AFTERNOON...AND IT IS FORECAST TO MOVE OVER
EASTERN LAKE SUPERIOR TONIGHT...AND CONTINUE EAST ON SATURDAY.
LIGHT SNOW WILL LINGER TONIGHT...BUT BE MOST WIDESPREAD THROUGH
THE EVENING HOURS. INTENSITY OVERALL WILL BE LIGHT...BUT THERE
WILL BE PERIODS OF MODERATE SNOW WITH VSBYS DOWN TO AROUND A MILE
FOR A TIME. WE WENT WITH ADDITIONAL SNOWFALL AROUND AN INCH FOR
MOST AREAS...BUT WENT A BIT HIGHER OVER PORTIONS OF THE ARROWHEAD
AND ALONG THE SOUTH SHORE. THE SOUTH SHORE WILL GET INTO LAKE
ENHANCED SNOWFALL TONIGHT AS WINDS TURN NORTHERLY AND WITH 850MB
TEMPS FORECAST TO DROP TO AROUND -12C AND INVERSION LEVELS
INCREASE. THE SOUTH SHORE WILL HAVE TO BE WATCHED CLOSELY...IF
STABILITY IS LOWER THAN EXPECTED...SNOW RATES COULD GET HEAVY AT
TIMES ACROSS THE SNOWBELT OF ASHLAND/IRON COUNTIES. THE OTHER AREA
WE`LL HAVE TO MONITOR IS ACROSS NORTH CENTRAL DOUGLAS
COUNTY...SOUTHWEST TOWARD SOUTHEAST CARLTON COUNTIES. AS LOW LEVEL
WINDS BACK TO NORTHWEST TONIGHT...WE COULD SEE A GRAVITY WAVE
INDUCED BAND OF ENHANCED SNOWFALL DEVELOP. LOOKING AT A RAP CROSS
SECTION...A STRONG SIGNAL IS NOT SEEN ATTM.
LIGHT SNOW OR FLURRIES WILL LINGER INTO SATURDAY
MORNING...PARTICULARLY OVER THE EASTERN HALF OF THE CWA DUE TO THE
SLOW DEPARTURE OF THE UPPER LOW. HOWEVER...ADDITIONAL SNOWFALL
WILL BE QUITE LIGHT IF ANYTHING MEASURES AT ALL.
WE EXPECT HIGHS SATURDAY TO REACH THE 35 TO 40 FOR MOST AREAS.
LONG TERM...SATURDAY NIGHT - FRIDAY.
THE FOCUS IN THIS FORECAST IS THE WINTER STORM SYSTEM THAT IS
EXPECTED TO AFFECT THE NORTHLAND LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. THE MODELS CONTINUE TO INDICATE THAT A POTENT MID/UPPER LOW
PRESSURE SYSTEM AND ITS ASSOCIATED LOW PRESSURE SYSTEM AT THE
SURFACE WILL MOVE THROUGH THE NORTHERN PLAINS SUNDAY AND MOVE INTO
ONTARIO MONDAY.THE MODELS SEEM TO HAVE INCREASED THEIR SNOWFALL FOR
THIS SYSTEM FOR LATE SATURDAY NIGHT THROUGH MONDAY MORNING...AND
TRENDED A LITTLE COLDER. I STILL THINK THERE MAY BE A WINTRY MIX
ACROSS THE SOUTHERN FORECAST AREA DURING THE LATE MORNING AND AT
LEAST THE AFTERNOON DUE TO NOT ONLY WARMER SURFACE
TEMPERATURES...BUT INCREASING TEMPERATURES ALOFT. I DO NOT SEE ANY
SIGNIFICANT RISK OF FREEZING RAIN BASED ON THE SOUNDINGS...BUT WE
WILL NEED TO CONTINUALLY CHECK INTO THIS. THE WINTRY MIX ACROSS THE
SOUTH WILL LIKELY PREVENT MUCH ACCUMULATION OF SNOW...SO MOST OF THE
CONCERN IS FOR NE MINNESOTA FOR HEAVY SNOW WHERE TEMPERATURES WILL
BE COLDER. THIS STORM SYSTEM IS LOOKING MORE AND MORE LIKELY THAT IT
WILL BRING AT LEAST A WIDESPREAD 6 TO 8 INCHES ACROSS NE
MINNESOTA...ESPECIALLY NORTH OF HIGHWAY 2. SOME ARES OF FAR NORTHERN
MINNESOTA MAY GET UP TO 10 INCHES. I MAY BE ON THE HIGH SIDE WITH
THE STORM TOTAL SNOWFALL...SO I DO NOT IMAGINE AT THIS POINT THAT
THIS STORM WOULD YIELD MUCH MORE SNOW THAN THIS.
LIGHT SNOW COULD LINGER ACROSS NE MINNESOTA MONDAY INTO TUESDAY IN
THE WAKE OF THE STORM SYSTEM. BEYOND TUESDAY...PREVIOUS MODEL RUNS
HAD BEEN INDICATING THE POTENTIAL FOR ANOTHER WINTRY-WEATHER SYSTEM
MID TO LATE WEEK...BUT IT WAS GOING TO BE DEPENDENT THE TRACK OF THE
ASSOCIATED LOW PRESSURE SYSTEM. THE LATEST GFS AND ECMWF ARE BACKING
OFF ON HAVING THIS SYSTEM AFFECTING THE NORTHLAND IN THAT THEY HAVE
THE LOW TRACK VERY FAR SOUTH...BASICALLY FROM THE SOUTHERN PLAINS TO
MICHIGAN. HOWEVER...THE GEM HAS A TRACK THAT IS SIGNIFICANTLY
FARTHER NORTH AND STILL SUGGESTS THE POTENTIAL TO BRING SIGNIFICANT
SNOWFALL TO PARTS OF THE NORTHLAND MID TO LATE WEEK. UNTIL AND IF
THE GEM BACKS OFF ON THE SYSTEM...THAT WE STILL NEED TO CARRY PCPN
CHANCES FOR THE MID TO LATE WEEK.
OVERALL THE COLD WEATHER PATTERN IS EXPECTED TO CONTINUE OVER THE
UPCOMING WEEK.
AVIATION...18Z TAF ISSUANCE.
WIDESPREAD IFR/MVFR CIGS AND/OR VSBYS ARE EXPECTED ACROSS NE
MINNESOTA AND NW WISCONSIN THROUGH SATURDAY MORNING DUE TO LOW
CIGS AND LINGERING SNOW ACROSS THE REGION. THERE MAY BE PERIODS OF
LIFR CONDITIONS THIS AFTERNOON DUE TO REDUCED VSBY FROM HIGHER
SNOWFALL RATES...ESPECIALLY AT KDLH. THE 10 TO 20 KNOT NE WINDS
WILL WEAKEN AND BECOME N TO NNW TONIGHT. THERE MAY BE GRADUAL
IMPROVEMENT TO WIDESPREAD MVFR LATE TOMORROW MORNING IF THE CIGS
LIFT.
&&
.POINT TEMPS/POPS...
DLH 30 23 37 21 / 100 90 30 10
INL 30 19 38 17 / 100 70 20 0
BRD 32 24 38 24 / 70 70 30 50
HYR 34 20 38 20 / 100 80 40 10
ASX 30 24 37 17 / 100 90 60 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MNZ025-033>036.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ010-011-018-019-026-037.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ012-020-021.
WI...WINTER WEATHER ADVISORY UNTIL 7 AM CDT SATURDAY FOR WIZ003-004.
WINTER STORM WARNING UNTIL 7 AM CDT SATURDAY FOR WIZ002.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-147-148.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT SATURDAY FOR LSZ140>146.
&&
$$
SHORT TERM...MILLER
AREA FORECAST DISCUSSION
NWS DULUTH MN
345 PM CDT FRI APR 12 2013
.SHORT TERM...THROUGH SATURDAY.
WATER VAPOR SHOWS THE UPPER LOW MOVING NORTHEAST ACROSS NORTHERN
WISCONSIN THIS AFTERNOON...AND IT IS FORECAST TO MOVE OVER
EASTERN LAKE SUPERIOR TONIGHT...AND CONTINUE EAST ON SATURDAY.
LIGHT SNOW WILL LINGER TONIGHT...BUT BE MOST WIDESPREAD THROUGH
THE EVENING HOURS. INTENSITY OVERALL WILL BE LIGHT...BUT THERE
WILL BE PERIODS OF MODERATE SNOW WITH VSBYS DOWN TO AROUND A MILE
FOR A TIME. WE WENT WITH ADDITIONAL SNOWFALL AROUND AN INCH FOR
MOST AREAS...BUT WENT A BIT HIGHER OVER PORTIONS OF THE ARROWHEAD
AND ALONG THE SOUTH SHORE. THE SOUTH SHORE WILL GET INTO LAKE
ENHANCED SNOWFALL TONIGHT AS WINDS TURN NORTHERLY AND WITH 850MB
TEMPS FORECAST TO DROP TO AROUND -12C AND INVERSION LEVELS
INCREASE. THE SOUTH SHORE WILL HAVE TO BE WATCHED CLOSELY...IF
STABILITY IS LOWER THAN EXPECTED...SNOW RATES COULD GET HEAVY AT
TIMES ACROSS THE SNOWBELT OF ASHLAND/IRON COUNTIES. THE OTHER AREA
WE`LL HAVE TO MONITOR IS ACROSS NORTH CENTRAL DOUGLAS
COUNTY...SOUTHWEST TOWARD SOUTHEAST CARLTON COUNTIES. AS LOW LEVEL
WINDS BACK TO NORTHWEST TONIGHT...WE COULD SEE A GRAVITY WAVE
INDUCED BAND OF ENHANCED SNOWFALL DEVELOP. LOOKING AT A RAP CROSS
SECTION...A STRONG SIGNAL IS NOT SEEN ATTM.
LIGHT SNOW OR FLURRIES WILL LINGER INTO SATURDAY
MORNING...PARTICULARLY OVER THE EASTERN HALF OF THE CWA DUE TO THE
SLOW DEPARTURE OF THE UPPER LOW. HOWEVER...ADDITIONAL SNOWFALL
WILL BE QUITE LIGHT IF ANYTHING MEASURES AT ALL.
WE EXPECT HIGHS SATURDAY TO REACH THE 35 TO 40 FOR MOST AREAS.
.LONG TERM...SATURDAY NIGHT - FRIDAY.
THE FOCUS IN THIS FORECAST IS THE WINTER STORM SYSTEM THAT IS
EXPECTED TO AFFECT THE NORTHLAND LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. THE MODELS CONTINUE TO INDICATE THAT A POTENT MID/UPPER LOW
PRESSURE SYSTEM AND ITS ASSOCIATED LOW PRESSURE SYSTEM AT THE
SURFACE WILL MOVE THROUGH THE NORTHERN PLAINS SUNDAY AND MOVE INTO
ONTARIO MONDAY.THE MODELS SEEM TO HAVE INCREASED THEIR SNOWFALL FOR
THIS SYSTEM FOR LATE SATURDAY NIGHT THROUGH MONDAY MORNING...AND
TRENDED A LITTLE COLDER. I STILL THINK THERE MAY BE A WINTRY MIX
ACROSS THE SOUTHERN FORECAST AREA DURING THE LATE MORNING AND AT
LEAST THE AFTERNOON DUE TO NOT ONLY WARMER SURFACE
TEMPERATURES...BUT INCREASING TEMPERATURES ALOFT. I DO NOT SEE ANY
SIGNIFICANT RISK OF FREEZING RAIN BASED ON THE SOUNDINGS...BUT WE
WILL NEED TO CONTINUALLY CHECK INTO THIS. THE WINTRY MIX ACROSS THE
SOUTH WILL LIKELY PREVENT MUCH ACCUMULATION OF SNOW...SO MOST OF THE
CONCERN IS FOR NE MINNESOTA FOR HEAVY SNOW WHERE TEMPERATURES WILL
BE COLDER. THIS STORM SYSTEM IS LOOKING MORE AND MORE LIKELY THAT IT
WILL BRING AT LEAST A WIDESPREAD 6 TO 8 INCHES ACROSS NE
MINNESOTA...ESPECIALLY NORTH OF HIGHWAY 2. SOME ARES OF FAR NORTHERN
MINNESOTA MAY GET UP TO 10 INCHES. I MAY BE ON THE HIGH SIDE WITH
THE STORM TOTAL SNOWFALL...SO I DO NOT IMAGINE AT THIS POINT THAT
THIS STORM WOULD YIELD MUCH MORE SNOW THAN THIS.
LIGHT SNOW COULD LINGER ACROSS NE MINNESOTA MONDAY INTO TUESDAY IN
THE WAKE OF THE STORM SYSTEM. BEYOND TUESDAY...PREVIOUS MODEL RUNS
HAD BEEN INDICATING THE POTENTIAL FOR ANOTHER WINTRY-WEATHER SYSTEM
MID TO LATE WEEK...BUT IT WAS GOING TO BE DEPENDENT THE TRACK OF THE
ASSOCIATED LOW PRESSURE SYSTEM. THE LATEST GFS AND ECMWF ARE BACKING
OFF ON HAVING THIS SYSTEM AFFECTING THE NORTHLAND IN THAT THEY HAVE
THE LOW TRACK VERY FAR SOUTH...BASICALLY FROM THE SOUTHERN PLAINS TO
MICHIGAN. HOWEVER...THE GEM HAS A TRACK THAT IS SIGNIFICANTLY
FARTHER NORTH AND STILL SUGGESTS THE POTENTIAL TO BRING SIGNIFICANT
SNOWFALL TO PARTS OF THE NORTHLAND MID TO LATE WEEK. UNTIL AND IF
THE GEM BACKS OFF ON THE SYSTEM...THAT WE STILL NEED TO CARRY PCPN
CHANCES FOR THE MID TO LATE WEEK.
OVERALL THE COLD WEATHER PATTERN IS EXPECTED TO CONTINUE OVER THE
UPCOMING WEEK.
&&
.AVIATION...18Z TAF ISSUANCE.
WIDESPREAD IFR/MVFR CIGS AND/OR VSBYS ARE EXPECTED ACROSS NE
MINNESOTA AND NW WISCONSIN THROUGH SATURDAY MORNING DUE TO LOW
CIGS AND LINGERING SNOW ACROSS THE REGION. THERE MAY BE PERIODS OF
LIFR CONDITIONS THIS AFTERNOON DUE TO REDUCED VSBY FROM HIGHER
SNOWFALL RATES...ESPECIALLY AT KDLH. THE 10 TO 20 KNOT NE WINDS
WILL WEAKEN AND BECOME N TO NNW TONIGHT. THERE MAY BE GRADUAL
IMPROVEMENT TO WIDESPREAD MVFR LATE TOMORROW MORNING IF THE CIGS
LIFT.
&&
.POINT TEMPS/POPS...
DLH 23 37 21 33 / 90 30 10 100
INL 19 38 17 37 / 60 20 0 90
BRD 24 38 24 37 / 50 10 50 100
HYR 20 38 20 41 / 80 40 10 100
ASX 24 37 17 39 / 90 60 0 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MNZ025-033>036.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ010-011-018-019-026-037.
WINTER STORM WARNING UNTIL 10 PM CDT THIS EVENING FOR MNZ012-021.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ012-020-021.
WINTER STORM WARNING UNTIL 5 PM CDT THIS AFTERNOON FOR MNZ020-
037.
WINTER WEATHER ADVISORY UNTIL 5 PM CDT THIS AFTERNOON FOR MNZ011-
019.
WI...WINTER STORM WARNING UNTIL 5 PM CDT THIS AFTERNOON FOR WIZ001.
WINTER WEATHER ADVISORY UNTIL 7 AM CDT SATURDAY FOR WIZ003-004.
WINTER STORM WARNING UNTIL 7 AM CDT SATURDAY FOR WIZ002.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-147-148.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT SATURDAY FOR LSZ142>146.
SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ140-141.
&&
$$
SHORT TERM...MELDE
LONG TERM....GROCHOCINSKI
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
136 AM EDT SAT APR 13 2013
.SYNOPSIS...
UNSETTLED WEATHER EXPECTED THROUGH SUNDAY AS AN UPPER LEVEL
DISTURBANCE REMAINS ACROSS THE NORTHEASTERN UNITED STATES. HIGH
PRESSURE WILL BUILD LATE SUNDAY WITH TEMPERATURES MODERATING
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
930 PM UPDATE...H5 SHORT WAVE MOVING FROM NORTHWEST PA INTO
CENTRAL NY IS GENERATING MORE SCATTERED RAIN SHOWERS OVER THE
REGION. INCREASED SHORT TERM POPS TO REFLECT THIS BUT EXPECT ACTIVITY
TO DIMINISH AGAIN AFTER MIDNIGHT AS WAVE MOVES THROUGH. CURRENT
FORECAST IN GREAT SHAPE JUST NEAR TERM POP/TEMP ADJUSTMENTS.
315 PM UPDATE.. WIDESPREAD RAIN HAS MOVED THROUGH THE CWA EARLIER
THAN EXPECTED TODAY WITH MAINLY LIGHT SHOWERS AND DRIZZLE LEFT
OVER. OCCLUDED FRONT PROGGED TO MV THRU THIS EVNG WITH A LINE OF
SHOWERS ACCOMPANYING IT THRU ABOUT MIDNIGHT. HRRR HAS FAIRLY GOOD
HANDLE ON LINE OF SHOWERS ALONG FRONT AND EXPECT THIS TO CONTINUE
TO PROGRESS THRU THE AREA TONIGHT. SHOWERS LOOK TO COME TO AN END
BY ABOUT 06Z AS S/WV CURRENTLY ACRS SRN ILLINOIS PUSHES THRU THE
REGION.
BNDRY LYR EXPECTED TO RMN WARM ENUF FOR RAIN SHOWERS UP THRU ABOUT
06Z BFR COLD AIR WORKS INTO THE LOWEST LEVELS. CHC OF SNOW SHOWERS
WL LKLY BE CONFINED TO ELEVATIONS ABV 1500FT AS LOW LYRS RMN WARM.
SKIES WL BCM PRTLY CLDY FM THE SOUTH TWD DAYBREAK AND MIN TEMPS WL
RMN IN THE MID-UPR 30S TO ARND 40F ACRS FAR SRN ZONES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
315 PM UPDATE...
YET ANOTHER S/WV WL ROTATE THRU SAT AFTN AND KEEP THE CHC FOR
SHOWERS GOING. EXPECTING LESS THAN A TENTH OF AN INCH THRU THE DAY
TOMORROW. WITH PSUNNY SKIES EXPECTED TOMORROW ACROSS MAJORITY OF CWA
TEMPS WL RISE TO AROUND 50 DEGREES EXCEPT THEY MAY STAY DOWN IN THE
40S ACRS THE NORTH.
SUNDAY WL LKLY RESULT IN HIGHS BLO CLIMO ACRS NY STATE WITH COLD AIR
FILTERING IN FM CANADA ON NRLY FLOW WITH SFC HIPRES BUILDING IN FM
THE WEST. H8 TEMPS EXPECTED TO DROP TO BTWN -6C AND -9C. EXPECT
WINDS TO BE OUT OF THE WEST BUT LITTLE CHC FOR LK EFFECT OVR FAR NRN
ZONES WITH DELTA T`S EARLY IN THE DAY ARND 12C AND HV KEPT LO-SLGT
CHC POPS THRU 18Z SUNDAY.
HIPRES WL END THE SHORT TERM WITH NO WX EXPECTED FM ABOUT SUN AFTN
THRU THE DAY MONDAY. TEMPS WL MODERATE THRU EARLY NEXT WEEK WITH
MAXES PROGGED TO BE IN THE 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 PM UPDATE...
FOLLOWED WPC GUIDANCE WITH A PATTERN THAT LOOKS SIMILAR TO THIS
PAST WEEK. EARLY IN THE PERIOD RIDGING IN THE EAST AND A TROF OVER
THE DESERT SOUTHWEST WILL KEEP US WITH A WARM FLOW OF AIR WITH
850S AROUND 12C TUESDAY MORNING. EVENTUALLY BOTH THE EURO AND GFS
SHOW A COLD FRONT MOVING INTO OUR AREA THEN WAFFLING BACK AND
FORTH THROUGH THE WEEK. TIMING AND PLACEMENT DIFFERENCES EXIST BUT
THE OVERALL IDEA OF A WET AND UNSETTLED PATTERN LOOK SOLID. TEMPS
ARE GENERALLY IN THE 60S AND THIS IS A GOOD START FOR NOW. AS WE
GET CLOSER AND THE DETAILS GET IRONED OUT WE MAY AGAIN SEE LARGE
NORTH/SOUTH TEMPERATURE DIFFERENCES DUE TO THE FRONTAL POSITION.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A PUSH OF DRY AIR ALONG A COLD FRONT HAS ARRIVED AT OUR NY
TERMINALS, BRINGING CEILINGS UP TO VFR. THE FRONT IS GETTING CLOSE
TO AVP, BUT IR SAT PROGS THE DRY AIR PUSH TO ARRIVE JUST PRIOR TO
7Z. FOR THIS REASON THE AVP TERMINAL IS FORECAST TO HAVE TEMPO IFR
CEILINGS FOR 1-2 HOURS.
SOME CONCERN THAT BGM/RME MAY FLIRT WITH IFR OVERNIGHT DUE TO LOW
TDD VALUES. HOWEVER THERE IS QUITE A BIT OF MIXING, AND LATEST
BUFKIT RAP DATA SHOWS NO IFR CLOUD POTENTIAL.
MVFR CLOUDS ARE PROGGED TO REFORM BETWEEN 10Z AND 14Z. CEILINGS
THIS AFTERNOON WILL BE BETWEEN 2500 AND 4000 FEET. MVFR
RESTRICTIONS IN SHOWER ACTIVITY ARE POSSIBLE TONIGHT.
.OUTLOOK...
SAT NGT TO SUN...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
SUN NGT TO MON...VFR.
MON NGT TO WED...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...HEDEN
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1026 PM EDT FRI APR 12 2013
.SYNOPSIS...
A LOW PRESSURE AREA WILL PASS SOUTH OF NEW ENGLAND OVERNIGHT.
AN UPPER LOW OVER THE GREAT LAKES WILL BRING A CHANCE OF RAIN AND
SNOW SHOWERS TO THE NORTH COUNTRY SATURDAY AND SUNDAY. A RIDGE OF
HIGH PRESSURE WILL BUILD INTO THE NORTH COUNTRY SUNDAY NIGHT AND MONDAY
WITH FAIR AND DRY WEATHER EXPECTED.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
AS OF 1019 PM EDT FRIDAY...STILL DEALING WITH SOME ICING
ISSUES...GENERALLY ALONG/EAST OF THE GREEN MTNS FROM I-89
NORTHWARD TO THE CANADIAN BORDER WITH AREAS OF IP/FZRA. THE 02Z
OBSERVATIONS INDICATE TEMPS 31F AT MPV AND 32F AT EFK (NEWPORT VT).
UP AT 2200FT...WALDEN VT REMAINS 27F. STILL SOME BROAD ISENTROPIC
UPGLIDE OCCURRING FROM SW-NE ACROSS THE FORECAST AREA LATE THIS
EVENING WITH INTERMITTENT LIGHT RAIN IN THE CHAMPLAIN VALLEY...AND
PERIODS OF LIGHT SLEET/FZRA ACROSS FAR N-CENTRAL AND NERN VT. GENERALLY
LOOKING FOR MID-LEVEL DRYING NEXT FEW HOURS...WHICH WILL ALLOW THE
INTERMITTENT IP/FZRA TO END. ALSO... RAP SOUNDINGS SHOW GENERAL
COOLING OF VERTICAL TEMPERATURE PROFILE OVERNIGHT...WITH ABOVE
FREEZING LAYER DISSIPATING AROUND 05Z. FROM THAT POINT
ONWARD...ANTICIPATE ANY LINGERING SHOWERY PRECIPITATION ACROSS
N-CENTRAL/NERN VT WILL FALL AS SNOW SHOWERS OR FLURRIES WITH A
LIGHT COATING POSSIBLE IN SPOTS. HAZARDOUS WEATHER OUTLOOK
CONTINUES TO EMPHASIZE THE PROSPECT FOR LOCALIZED ICY SPOTS
LINGERING ON UNTREATED SECONDARY AND DIRT ROADS OVERNIGHT
CENTRAL/ERN VT...ESPECIALLY AT ELEVATIONS ABOVE 1000 FEET.
TRAVELERS OVERNIGHT IN N-CENTRAL/NERN VT SHOULD CONTINUE TO
EXERCISE CAUTION WITH NEAR STEADY TEMPS AROUND FREEZING EVEN AS
THE FREEZING PRECIPITATION ENDS.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 451 PM EDT FRIDAY...A CLOSED UPPER LOW OVER THE GREAT LAKES
EARLY SATURDAY WILL DRIFT SLOWLY EAST THROUGH SUNDAY. THIS UPPER
LOW WILL KEEP TEMPERATURES BELOW NORMAL SATURDAY AND
SUNDAY...ALONG WITH BRINGING A CHANCE OF RAIN AND SNOW SHOWERS TO
THE NORTH COUNTRY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE
REGION SUNDAY NIGHT WITH FAIR AND DRY WEATHER EXPECTED.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...THE BATTLE OF SPRING VS WINTER WL CONT
ACRS THE NE CONUS FOR THE EXTENDED...WITH LATEST MODEL TRENDS
INDICATING SOME SPRINGLIKE WX IS POSSIBLE. BOTH GFS/ECMWF SHOW
DEVELOPMENT OF MID/UPPER LVL RIDGE ACRS THE SE CONUS FOR NEXT
WEEK...WHILE SFC LOW PRES TRACKS TO OUR WEST...PLACING OUR CWA IN
THE WARM SECTOR. HOWEVER...THIS PATTERN WAS ALSO SUPPOSE TO HAPPEN
TODAY...INSTEAD THE LOW TRACKED TO OUR SOUTH...AND A SHARP THERMAL
GRADIENT WAS PRESENT WITH MIXED PRECIP. IN ADDITION...MODELS CONT
TO SHOW A STRONG SFC HIGH PRES LOCATED NEAR HUDSON BAY NEXT
WEEK AND THE ANTICYCLONIC FLW AROUND THIS SYSTEM MAY SUPPRESS THE
WARM UP. ITS ALWAYS VERY DIFFICULT TO DETERMINE EXACT POSITION OF
BOUNDARY IN THE DAY 4 THRU 7 PERIOD...ESPECIALLY GIVEN TIGHT
THERMAL GRADIENT. GIVEN THE UNCERTAINTY WL KEEP TEMPS CLOSE TO
SEASONAL NORMALS...BUT COULD EASILY SEE TEMPS WELL INTO THE
60S/L70S IF THE ECMWF PROGGED 85H TEMPS BTWN 10 AND 12C VERIFY ON
THURSDAY. GIVEN POSITION OF SFC BOUNDARY AND EMBEDDED
VORTS/ENHANCED MOISTURE WL KEEP FA UNSETTLED DURING THE EXTENDED
PERIOD. DIFFICULT TO DETERMINE EXACT TIMING OF SYSTEMS WITH FAST
FLW ALOFT. WL KEEP MENTION OF CHC POPS ON TUES...THEN AGAIN THURS
INTO FRIDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...SCATTERED RAIN WITH MTN RAIN/SNOW SHOWERS
THRU 02-03Z...THEN SOME DRY SLOT CONDS BEFORE A FEW MORE
SHORTWAVES DELIVER CHCS PRIOR TO DAYBREAK AND THEN SAT AFTN.
LIGHTER WNDS WILL LIKELY MEAN MVFR FOR MANY LOCALES DUE TO CIGS
AND SOME IFR CONDS PSBL AT KSLK. KMSS LIFR AT 00Z WILL LIKELY
IMPROVE TO MVFR/IFR AS WINDS SHIFT SW BY 03-04Z.
VFR-MVFR FOR SATURDAY WITH SOME ISOLD IFR PSBL WITH AFTN SHOWERS
FOR KSLK. WINDS WILL BE < 10 KTS.
OUTLOOK 00Z SUNDAY THROUGH TUESDAY...
00Z SUNDAY THROUGH 00Z MONDAY...CONTINUED UNSETTLED CONDITIONS
WITH A MIX OF MVFR/VFR LIKELY AS AN UPPER LOW OVER CANADA PRODUCES
SCATTERED RAIN AND SNOW SHOWERS...WITH SNOW SHOWERS MAINLY OVER
THE HIGHER ELEVATIONS OF THE ADIRONDACKS AND GREEN MOUNTAINS.
00Z MONDAY THROUGH 00Z TUESDAY...VFR CONDITIONS EXPECTED AS A
RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION.
00Z TUESDAY THROUGH 00Z WEDNESDAY...MVFR/IFR CONDITIONS POSSIBLE
IN RAIN SHOWERS AS A COLD FRONT MOVES THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...WGH
NEAR TERM...BANACOS
SHORT TERM...WGH
LONG TERM...TABER
AVIATION...TABER/SLW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
946 PM EDT FRI APR 12 2013
.SYNOPSIS...
UNSETTLED WEATHER EXPECTED THROUGH SUNDAY AS AN UPPER LEVEL
DISTURBANCE REMAINS ACROSS THE NORTHEASTERN UNITED STATES. HIGH
PRESSURE WILL BUILD LATE SUNDAY WITH TEMPERATURES MODERATING
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
930 PM UPDATE...H5 SHORT WAVE MOVING FROM NORTHWEST PA INTO
CENTRAL NY IS GENERATING MORE SCATTERED RAIN SHOWERS OVER THE
REGION. INCREASED SHORT TERM POPS TO REFLECT THIS BUT EXPECT ACTIVITY
TO DIMINISH AGAIN AFTER MIDNIGHT AS WAVE MOVES THROUGH. CURRENT
FORECAST IN GREAT SHAPE JUST NEAR TERM POP/TEMP ADJUSTMENTS.
315 PM UPDATE.. WIDESPREAD RAIN HAS MOVED THROUGH THE CWA EARLIER
THAN EXPECTED TODAY WITH MAINLY LIGHT SHOWERS AND DRIZZLE LEFT
OVER. OCCLUDED FRONT PROGGED TO MV THRU THIS EVNG WITH A LINE OF
SHOWERS ACCOMPANYING IT THRU ABOUT MIDNIGHT. HRRR HAS FAIRLY GOOD
HANDLE ON LINE OF SHOWERS ALONG FRONT AND EXPECT THIS TO CONTINUE
TO PROGRESS THRU THE AREA TONIGHT. SHOWERS LOOK TO COME TO AN END
BY ABOUT 06Z AS S/WV CURRENTLY ACRS SRN ILLINOIS PUSHES THRU THE
REGION.
BNDRY LYR EXPECTED TO RMN WARM ENUF FOR RAIN SHOWERS UP THRU ABOUT
06Z BFR COLD AIR WORKS INTO THE LOWEST LEVELS. CHC OF SNOW SHOWERS
WL LKLY BE CONFINED TO ELEVATIONS ABV 1500FT AS LOW LYRS RMN WARM.
SKIES WL BCM PRTLY CLDY FM THE SOUTH TWD DAYBREAK AND MIN TEMPS WL
RMN IN THE MID-UPR 30S TO ARND 40F ACRS FAR SRN ZONES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
315 PM UPDATE...
YET ANOTHER S/WV WL ROTATE THRU SAT AFTN AND KEEP THE CHC FOR
SHOWERS GOING. EXPECTING LESS THAN A TENTH OF AN INCH THRU THE DAY
TOMORROW. WITH PSUNNY SKIES EXPECTED TOMORROW ACROSS MAJORITY OF CWA
TEMPS WL RISE TO AROUND 50 DEGREES EXCEPT THEY MAY STAY DOWN IN THE
40S ACRS THE NORTH.
SUNDAY WL LKLY RESULT IN HIGHS BLO CLIMO ACRS NY STATE WITH COLD AIR
FILTERING IN FM CANADA ON NRLY FLOW WITH SFC HIPRES BUILDING IN FM
THE WEST. H8 TEMPS EXPECTED TO DROP TO BTWN -6C AND -9C. EXPECT
WINDS TO BE OUT OF THE WEST BUT LITTLE CHC FOR LK EFFECT OVR FAR NRN
ZONES WITH DELTA T`S EARLY IN THE DAY ARND 12C AND HV KEPT LO-SLGT
CHC POPS THRU 18Z SUNDAY.
HIPRES WL END THE SHORT TERM WITH NO WX EXPECTED FM ABOUT SUN AFTN
THRU THE DAY MONDAY. TEMPS WL MODERATE THRU EARLY NEXT WEEK WITH
MAXES PROGGED TO BE IN THE 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 PM UPDATE...
FOLLOWED WPC GUIDANCE WITH A PATTERN THAT LOOKS SIMILAR TO THIS
PAST WEEK. EARLY IN THE PERIOD RIDGING IN THE EAST AND A TROF OVER
THE DESERT SOUTHWEST WILL KEEP US WITH A WARM FLOW OF AIR WITH
850S AROUND 12C TUESDAY MORNING. EVENTUALLY BOTH THE EURO AND GFS
SHOW A COLD FRONT MOVING INTO OUR AREA THEN WAFFLING BACK AND
FORTH THROUGH THE WEEK. TIMING AND PLACEMENT DIFFERENCES EXIST BUT
THE OVERALL IDEA OF A WET AND UNSETTLED PATTERN LOOK SOLID. TEMPS
ARE GENERALLY IN THE 60S AND THIS IS A GOOD START FOR NOW. AS WE
GET CLOSER AND THE DETAILS GET IRONED OUT WE MAY AGAIN SEE LARGE
NORTH/SOUTH TEMPERATURE DIFFERENCES DUE TO THE FRONTAL POSITION.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
730 PM UPDATE...
SLOW MOVING FRONT NEAR ELM MOVING EAST THROUGH THE REST OF THE TAF
SITES THIS EVENING. IFR AND LOW MVFR CIGS WILL CONTINUE THROUGH
MOST OF THE NIGHT. SOME DRIZZLE AND LIGHT SHOWERS AHEAD OF THE
FRONT CAUSING MVFR AND IFR VSBYS. THIS WILL END ALLOWING VSBYS TO
RISE BACK TO VFR. AROUND 12Z MVFR CIGS THEN BY 16Z VFR.
SE WINDS AT 5 TO 8 KTS AHEAD OF THE FRONT BECOMING W TO NW AT 5 TO
8 KTS THIS EVENING BEHIND THE FRONT. SOME LOCATIONS SUCH AS ELM
WILL PROBABLY BE LIGHT AND VARIABLE. SATURDAY WEST WINDS AT 10
KTS.
.OUTLOOK...
SAT NGT TO SUN...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
SUN NGT TO MON...VFR.
MON NGT TO WED...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...HEDEN
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
808 PM EDT FRI APR 12 2013
.SYNOPSIS...
UNSETTLED WEATHER EXPECTED THROUGH SUNDAY AS AN UPPER LEVEL
DISTURBANCE REMAINS ACROSS THE NORTHEASTERN UNITED STATES. HIGH
PRESSURE WILL BUILD LATE SUNDAY WITH TEMPERATURES MODERATING
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
315 PM UPDATE..
WIDESPREAD RAIN HAS MOVED THROUGH THE CWA EARLIER THAN EXPECTED
TODAY WITH MAINLY LIGHT SHOWERS AND DRIZZLE LEFT OVER. OCCLUDED
FRONT PROGGED TO MV THRU THIS EVNG WITH A LINE OF SHOWERS
ACCOMPANYING IT THRU ABOUT MIDNIGHT. HRRR HAS FAIRLY GOOD HANDLE ON
LINE OF SHOWERS ALONG FRONT AND EXPECT THIS TO CONTINUE TO PROGRESS
THRU THE AREA TONIGHT. SHOWERS LOOK TO COME TO AN END BY ABOUT 06Z
AS S/WV CURRENTLY ACRS SRN ILLINOIS PUSHES THRU THE REGION.
BNDRY LYR EXPECTED TO RMN WARM ENUF FOR RAIN SHOWERS UP THRU ABOUT
06Z BFR COLD AIR WORKS INTO THE LOWEST LEVELS. CHC OF SNOW SHOWERS
WL LKLY BE CONFINED TO ELEVATIONS ABV 1500FT AS LOW LYRS RMN WARM.
SKIES WL BCM PRTLY CLDY FM THE SOUTH TWD DAYBREAK AND MIN TEMPS WL
RMN IN THE MID-UPR 30S TO ARND 40F ACRS FAR SRN ZONES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
315 PM UPDATE...
YET ANOTHER S/WV WL ROTATE THRU SAT AFTN AND KEEP THE CHC FOR
SHOWERS GOING. EXPECTING LESS THAN A TENTH OF AN INCH THRU THE DAY
TOMORROW. WITH PSUNNY SKIES EXPECTED TOMORROW ACROSS MAJORITY OF CWA
TEMPS WL RISE TO AROUND 50 DEGREES EXCEPT THEY MAY STAY DOWN IN THE
40S ACRS THE NORTH.
SUNDAY WL LKLY RESULT IN HIGHS BLO CLIMO ACRS NY STATE WITH COLD AIR
FILTERING IN FM CANADA ON NRLY FLOW WITH SFC HIPRES BUILDING IN FM
THE WEST. H8 TEMPS EXPECTED TO DROP TO BTWN -6C AND -9C. EXPECT
WINDS TO BE OUT OF THE WEST BUT LITTLE CHC FOR LK EFFECT OVR FAR NRN
ZONES WITH DELTA T`S EARLY IN THE DAY ARND 12C AND HV KEPT LO-SLGT
CHC POPS THRU 18Z SUNDAY.
HIPRES WL END THE SHORT TERM WITH NO WX EXPECTED FM ABOUT SUN AFTN
THRU THE DAY MONDAY. TEMPS WL MODERATE THRU EARLY NEXT WEEK WITH
MAXES PROGGED TO BE IN THE 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 PM UPDATE...
FOLLOWED WPC GUIDANCE WITH A PATTERN THAT LOOKS SIMILAR TO THIS
PAST WEEK. EARLY IN THE PERIOD RIDGING IN THE EAST AND A TROF OVER
THE DESERT SOUTHWEST WILL KEEP US WITH A WARM FLOW OF AIR WITH
850S AROUND 12C TUESDAY MORNING. EVENTUALLY BOTH THE EURO AND GFS
SHOW A COLD FRONT MOVING INTO OUR AREA THEN WAFFLING BACK AND
FORTH THROUGH THE WEEK. TIMING AND PLACEMENT DIFFERENCES EXIST BUT
THE OVERALL IDEA OF A WET AND UNSETTLED PATTERN LOOK SOLID. TEMPS
ARE GENERALLY IN THE 60S AND THIS IS A GOOD START FOR NOW. AS WE
GET CLOSER AND THE DETAILS GET IRONED OUT WE MAY AGAIN SEE LARGE
NORTH/SOUTH TEMPERATURE DIFFERENCES DUE TO THE FRONTAL POSITION.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
730 PM UPDATE...
SLOW MOVING FRONT NEAR ELM MOVING EAST THROUGH THE REST OF THE TAF
SITES THIS EVENING. IFR AND LOW MVFR CIGS WILL CONTINUE THROUGH
MOST OF THE NIGHT. SOME DRIZZLE AND LIGHT SHOWERS AHEAD OF THE
FRONT CAUSING MVFR AND IFR VSBYS. THIS WILL END ALLOWING VSBYS TO
RISE BACK TO VFR. AROUND 12Z MVFR CIGS THEN BY 16Z VFR.
SE WINDS AT 5 TO 8 KTS AHEAD OF THE FRONT BECOMING W TO NW AT 5 TO
8 KTS THIS EVENING BEHIND THE FRONT. SOME LOCATIONS SUCH AS ELM
WILL PROBABLY BE LIGHT AND VARIABLE. SATURDAY WEST WINDS AT 10
KTS.
.OUTLOOK...
SAT NGT TO SUN...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
SUN NGT TO MON...VFR.
MON NGT TO WED...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...HEDEN
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1025 PM EDT FRI APR 12 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD IN BEHIND OUR DEPARTING FRONTAL
SYSTEM...BRINGING COOLER THAN NORMAL TEMPERATURES INTO THE
WEEKEND. THE HIGH WILL BUILD OVER THE EAST COAST AND ALLOW
INCREASINGLY MILD AIR TO MOVE NORTHWARD INTO THE REGION STARTING
ON MONDAY. NEXT WEEK LOOKS TO BE AT OR ABOVE NORMAL FOR
TEMPERATURES WITH SEVERAL MORE CHANCES FOR RAINFALL.
&&
.NEAR TERM /THROUGH SATURDAY/...
A FEW VERY LIGHT RETURNS CONTINUE OVER MY FAR EASTERN AND
NORTHEASTERN ZONES. LITTLE MORE THAN A STRAY SPRINKLE IS EXPECTED
INTO THE WEE HOURS. THE REMAINDER OF THE OVERNIGHT WILL SEE A
SMALL CHANCE OF SHOWERS REDEVELOP OVER THE NORTHWEST AND PERHAPS
DOWN INTO THE LAURELS...AND SOME OF THOSE SHOWERS MAY EVEN MIX
WITH WET SNOW OVER PARTS OF THE NORTHERN MOUNTAINS LATER TONIGHT.
BUT NOTHING OF SIGNIFICANCE IS EXPECTED.
LOWS WILL FALL TO NEAR FREEZING IN THE NORTHWEST...AND RANGE TO
NEAR 40 OVER THE SOUTHEAST.
AN APPROACHING WEAK TROUGH...ALONG WITH CONTINUED LOW LEVEL COLD
ADVECTION IS LIKELY TO KEEP A FAIR AMOUNT OF STRATO-CU IN THE
PICTURE FOR MUCH OF SATURDAY...WITH THE MOST CLOUDINESS OVER THE
NORTH AND WEST...AND MORE IN THE WAY OF PARTLY SUNNY SKIES
DEVELOPING OVER THE SOUTHEAST. HIGHS WILL REMAIN SEVERAL DEGREES
COOLER THAN NORMAL FOR MID APRIL.
&&
.SHORT TERM /SATURDAY NIGHT/...
HIGH PRESSURE WILL BEGIN BUILDING IN SATURDAY NIGHT. AS THE LAST
OF THE OVER-LAKE FLOW BRINGS CLOUDS AND LIGHT PRECIP TO THE
NORTHWEST...COULD ONCE AGAIN BE SOME LIGHT SNOW SHOWERS IN THE
AIR...BUT NO ACCUMS ARE EXPECTED. OVERNIGHT LOWS WILL BE SEVERAL
DEGREES COOLER THAN TONIGHT...STILL MUCH BELOW NORMAL.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
THE LARGE STORM THAT BROUGHT THE RECENT BOUT OF HEAVY SNOW TO THE
ROCKIES AND NORTHERN PLAINS STATES...ALONG WITH SEVERE WEATHER
ACROSS THE SOUTHERN PLAINS AND MISS VALLEY WILL SLOWLY WEAKEN AS IT
SLIDES EAST ACROSS THE UPPER GREAT LAKES TONIGHT AND SATURDAY.
THE SFC AND SLOWLY FILLING UPPER LOW...WILL WEAKEN AND ELONGATE
EAST-WEST ACROSS ONTARIO AND SRN QUEBEC DURING THE DAY SUNDAY. SOME
CLOUDS ACROSS THE NRN AND WESTERN MTNS /AND A FEW LIGHT RAIN AND
SNOW SHOWERS/ COULD STILL LINGER EARLY SUNDAY BEFORE THE POOL OF
UNSEASONABLY COLD 850-700 MB AIR RETREATS TO THE NE ACROSS NEW
ENGLAND.
850 MB TEMPS AVERAGING AROUND -2C /SW ZONES/ TO -5C ACROSS THE NE
PART OF PENN WILL COMBINE WITH THE MEAN WNW BLYR FLOW AND PERIODS OF
CLOUDS TO KEEP MAX TEMPS 3-5 DEG F BELOW NORMAL IN MOST PLACES
ACROSS SOUTHERN AND WESTERN PENN. THE GREATEST HIGH TEMP DEPARTURES
SUNDAY WILL BE ACROSS THE AREA NORTH AND EAST OF KIPT...WHERE THE
COLDER AIR ALOFT WILL LINGER THE LONGEST. VARIABLE AMOUNTS OF
HIGH-BASED STRATO CU AND SOME ALTO CU WILL LIKELY BE PRESENT ACROSS
THE CENTRAL AND SERN VALLEYS DURING THE DAY SUNDAY.
MAX TEMPS ACROSS THE HIGH PLATEAU OF SULLIVAN COUNTY MAY ONLY MAKE
IT TO THE MID 40S SUNDAY AFTERNOON. HIGHS ELSEWHERE ACROSS CENTRAL
AND NRN PA WILL BE BETWEEN 50-55F...WHILE THE SOUTHERN TIER SEES
MAXES REACH AROUND 60 DEGREES.
A WARM FRONT WILL PUSH NORTHEAST ACROSS THE FCST AREA SUNDAY NIGHT
AND MONDAY AS THE SFC RIDGE SLIDES OFF THE MID ATLANTIC COAST.
HOWEVER...WITH PRECIPITABLE WATER STILL BELOW THREE-QUARTERS OF AN
INCH /AROUND NORMAL/ AND A LACK OF ANY SIGNIFICANT FORCING
ALOFT...EXPECT THE PERIODS OF WARM ADVECTION ALTO CU TO CONTINUE
/ALONG WITH AN INCREASING SW BREEZE OVERNIGHT. ANY PRECIP IN THE
FORM OF SHOWERS WILL BE LIGHT AND SPOTTY AT BEST.
MONDAY WILL BE FEATURE PARTLY TO MOSTLY SUNNY SKIES...A GUSTY
SOUTHERLY BREEZE AND MUCH MILDER TEMPS.
MEDIUM RANGE OPERATIONAL MODELS...AND U.S./EURO ENSEMBLES CONTINUE
TO ADVERTISE ABOVE NORMAL HEIGHTS /PLUS 1-2 SIGMA/ ACROSS THE SERN
U.S. WITH A SERIES OF SHORT WAVES RIPPLING ENE ALONG A QUASI STNRY
FRONTAL BOUNDARY THAT WILL EXTEND FROM THE CENTRAL MISS VALLEY TO
THE EASTERN GREAT LAKES MONDAY THROUGH WEDNESDAY. MOST OF THE
SHOWERS ASSOCIATED WITH THIS FRONT SHOULD STAY JUST TO THE NW OF THE
STATE TUESDAY THROUGH THURSDAY.
HOWEVER...A PUSH OF COLDER AIR DIRECTED ACROSS UPSTATE NEW YORK AND
SERN CANADA TUESDAY NIGHT AND WED SHOULD ALLOW THE FRONT TO BRIEFLY
SLIP SOUTH ACROSS THE REGION ACCOMPANIED BY A VERY SHALLOW WEDGE OF
COOLER AIR AND SCATTERED SHOWERS. THE FRONT WILL STALL OUT NEAR OR
JUST SOUTH OF THE MASON-DIXON LINE DURING THE DAY WEDNESDAY BEFORE
RETURNING AS A WARM FRONT WED NIGHT AND THURSDAY.
FROM THIS VANTAGE POINT /NEARLY 7 DAYS OUT/...NEXT WEEK`S BIGGEST
RAIN MAKER LOOKS FAIRLY SIMILAR TO THE ONE THAT JUST MOVED THROUGH
THE REGION LAST NIGHT AND EARLIER TODAY - WITH RESPECT TO
TIMING...STRENGTH OF THE CFROPA AND POTENTIAL RAINFALL AMOUNTS OF
AROUND ONE INCH IN SOME AREAS.
BLEND OF ALL OPERATIONAL AND ENSEMBLE GUIDANCE SHOWS A QUITE CHILLY
AIRMASS MOVING INTO THE REGION FOR NEXT WEEKEND WITH THE LARGE SCALE
UPPER FLOW PATTERN FAVORING BELOW NORMAL HEIGHTS OF /-1 TO -2 SIGMA/
ACROSS THE MIDWEST AND PARTS OF THE NE U.S.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
EARLY EVENING SATL LOOP SHOWS LOW CLOUDS ENTRENCHED ACROSS EASTERN
PA...WHERE A MOIST...EASTERLY FLOW OFF OF THE ATLANTIC OCEAN
PERSISTS. MEANWHILE...A WARMER/DRIER SW FLOW HAS BROUGHT PARTIAL CLEARING
AND VFR CONDS ACROSS SW PA FROM JST TO AOO AT 23Z.
A COLD FRONT...JUST ENTERING WESTERN PA AT 23Z...WILL SWEEP
EASTWARD ACROSS THE REGION THIS EVENING...BRINGING WITH IT A
LIKELY RETURN TO MVFR STRATO-CU ACROSS THE W MTNS...AS BLYR COOLS
BENEATH STRENGTHENING INVERSION. THE 23Z IFR CIG AT BFD APPEARS TO
BE SHORT-LIVED...AS UPSTREAM OBS AND 13KM RAP SUGGEST DRIER AIR
WILL OVERSPREAD NW PA BY ARND 02Z. FURTHER EAST...LOW LVL
MOISTURE WILL BE SCOURED OUT UPON ARRIVAL OF OCCLUDED FRONT AND
DRIER WESTERLY FLOW. LATEST NEAR TERM MDL DATA SUGGESTS FRONT WILL
ARRIVE AT UNV BY 01Z...IPT ARND 03Z...MDT ARND 04Z AND LNS ARND
05Z.
ANY MVFR STRATO-CU ACROSS THE W MTNS SHOULD LIFT TO VFR BY MIDDAY
SAT DUE TO DIURNAL HEATING/STEEPENING LAPSE RTS. BIGGEST AVIATION
CONCERN SATURDAY WILL BE THE GUSTY WEST WINDS /BUFKIT SOUNDING
DATA SUPPORT AFTN GUSTS BTWN 20-25KTS/. PASSAGE OF AN UPPER LVL
TROF WILL LIKELY SUPPORT A FEW -SHSNRA OVR THE NW MTNS DURING THE
AFTN...WHICH COULD BRIEFLY LOWER VSBYS AT BFD.
.OUTLOOK...
SUN-MON...NO SIG WX EXPECTED.
TUE...AM LOW CIGS POSSIBLE.
WED...SCT TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/GARTNER
NEAR TERM...LA CORTE/GARTNER
SHORT TERM...DANGELO/GARTNER
LONG TERM...STEINBUGL/COLBERT
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS SPOKANE WA
808 PM PDT Fri Apr 12 2013
.SYNOPSIS...
The next storm system will spread rain and mountain snow into the
area starting tonight and Saturday. This storm will
also bring very windy conditions on Saturday, along with numerous
snow showers. Sunday will start a prolonged widespread cool and
showery period that will linger into the middle part of next week.
Snow levels will fall to the valley floors and mountain accumulations
will be likely.
&&
.DISCUSSION...
Our radar is filling in as widespread rainfall begins to fall over
much of the region. Water Vapor satellite imagery shows the upper
level cold front quickly pushing east of the Cascades around 700
PM this evening. A nicely defined dry slot can be made out moving
in behind this upper level front. The HRRR model is doing a pretty
good job handling the pcpn along the leading edge of the front.
Latest radar imagery seems to show a back edge beginning to into
the Moses Lake Area up into the Okanogan Highlands. This agrees
well with what the HRRR is suggesting as well. We will likely see
steady rainfall east of these areas over into the ID Panhandle
over the next 6 hours or so. Rainfall looks to exit the Spokane
Area between 11:00 PM and midnight tonight and then move east of
the ID Panhandle after about 2:00 AM on Saturday.
The main hazard for tonight will be snowfall in the mountains fort
he Northern Panhandle, Central Panhandle and in the east slopes of
the northern Cascades. Our winter weather advisory calling for 3
to 6 inches above 4000 feet looks good at this time for the ID
Panhandle. The main impact for travel in this area will be up over
Lookout Pass where hazardous travel is expected. The heaviest
snowfall in the east slopes of the northern Cascades will mainly
be right at the crest (especially as the cold front is moving
through). Behind the cold front, where we begin to tap into some
better instability with strong westerly flow, the HRRR model shows
a clear signature of a Puget Sound Convergent Zone setting up
across northern Chelan County around midnight and sliding
southward across Stevens Pass between 1:00 and 2:00 AM. Snow
levels will drop rapidly down into valley floors during this time
as well. This convergent zone does not appear as it will stretch
too far eastward, but the communities of Plain and possibly
Leavenworth could see some snowfall as this band moves in over the
area. The heaviest snowfall with this small scale band will likely
be reserved up over Stevens Pass. Snowfall rates could be quite
high due to the added lift from the low level convergence and
increasingly unstable lapse rates. As a result I bumped up snow
amounts quite a bit heading up to Stevens Pass where around an
inch of snow per hour will be possible between 1:00 and 5:00 AM.
We will keep our eye on this situation for the possibility of a
winter weather highlight, but, at this time, I am leaning toward
this being more of a localized event that would not need an
advisory along the east side of the northern Cascades. /SVH
&&
.AVIATION...
00Z TAFS: A strong cold front will sweep across the region tonight.
The atmosphere is moistening from the top down early this evening
with some sprinkles possible at KEAt and KMWH. More significant
rainfall will be more likely across extreme eastern WA into the ID
Panhandle. Expect -RA to begin at KGEG, KSFF and KCOE around 01Z and
about and hour later at KPUW and KLWS. KCOE and KPUW are expected
see a bit more moisture with the front and will see the best chances
for some MVFR cigs between 2-3 kft. Breezy conditions are expected
tonight, but even stronger winds will occur behind the front early
Saturday morning after 12Z. Expect westerly winds with gusts
increasing to between 30-45 kts through Saturday morning. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 34 48 32 48 31 49 / 90 50 40 40 30 30
Coeur d`Alene 33 45 31 46 30 48 / 90 70 50 50 40 30
Pullman 34 46 31 46 31 48 / 90 60 50 40 40 40
Lewiston 39 53 36 53 35 54 / 30 50 40 40 30 40
Colville 34 52 32 53 32 54 / 80 60 50 30 30 20
Sandpoint 33 44 31 45 30 46 / 100 80 70 50 40 30
Kellogg 32 37 29 40 27 41 / 100 80 60 70 50 40
Moses Lake 34 56 34 56 33 57 / 50 20 10 20 20 20
Wenatchee 33 51 34 53 34 54 / 10 10 10 20 20 20
Omak 30 55 30 55 32 56 / 20 20 20 30 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 2 AM to 7 PM PDT Saturday for Coeur d`Alene
Area-Idaho Palouse-Lewis and Southern Nez Perce Counties.
Winter Weather Advisory until 11 AM PDT Saturday for Central
Panhandle Mountains-Northern Panhandle.
WA...Wind Advisory from 2 AM to 7 PM PDT Saturday for Lower Garfield
and Asotin Counties-Moses Lake Area-Spokane Area-Upper
Columbia Basin-Washington Palouse-Waterville Plateau-
Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1201 AM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 915 PM MDT FRI APR 12 2013
INHERITED FORECAST IN GOOD SHAPE TONIGHT. LATEST HRRR CONTINUES TO
POINT TO AT LEAST SOME PATCHY FOG/LOW STRATUS DEVELOPMENT ACROSS
THE EASTERN PLAINS TONIGHT. IN FACT...LATEST OBSERVATIONS ALONG
THE I25 CORRIDOR AS WELL AS IN THE KIMBALL VICINITY ARE ALREADY
RECORDING CLOUDS DECKS BELOW 3000 FEET. THIS LINES UP WELL WITH
THE 11-3.9 SATELLITE FOG PRODUCT. IN A RECENT UPDATE...INCREASED
CLOUDS AS WELL AS ADDED MENTION OF FOG TO MUCH OF THE EASTERN
PLAINS. HAVE ALSO REMOVED FOG MENTION IN THE LARAMIE VALLEY AS
WIND SPEEDS ARE ANTICIPATED TO REMAIN TOO HIGH FOR ITS
DEVELOPMENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 331 PM MDT FRI APR 12 2013
PLENTY OF SHORT TERM CHALLENGES WITH THIS FORECAST PACKAGE.
CURRENTLY...UPPER LEVEL DISTURBANCE THAT BROUGHT THE MODERATE SNOW
TO PLATTE AND SOUTHERN CONVERSE COUNTY THIS MORNING IS NOW PUSHING
OFF INTO WESTERN NEBRASKA THIS AFTERNOON. STILL QUITE A BIT OF
RETURNS ON THE CHEYENNE RADAR...EVEN SOME LIGHTNING STRIKES OVER
NORTHERN AND NORTHEASTERN COLORADO...BUT FOR THE MOST
PART...WIDESPREAD SNOW HAS COME TO AN END AS TEMPERATURES HAVE
CLIMBED INTO THE UPPER 30S. WENT AHEAD AND CANCELLED THE SNOW
ADVISORY WE ISSUED THIS MORNING AS UPPER SHORT WAVE MOVES EAST.
REMAINING SHOWER ACTIVITY SHOULD DISSIPATE OUT WITH LOSS OF
DAYTIME HEATING AFTER SUNSET.
ATTENTION TURNS TO WINDS TONIGHT. UPPER RIDGE AXIS LOOKS TO PASS
OVER THE AREA BY MIDNIGHT TONIGHT. UP UNTIL THAT POINT...MAY SEE
SOME EVENING FOG AS WE HAVE SEEN THE PAST FEW EVENING. WEST TO
SOUTHWESTERLY WINDS BEGIN TO INCREASE SIGNIFICANTLY TOWARDS 12Z
SATURDAY WITH GFS FORECASTING 50KTS OUT BY ALBANY COUNTY. THIS IN
RESPONSE TO A FRONTAL SYSTEM MOVING INTO NORTHWEST WYOMING. BY 18Z
SATURDAY...WE SEE THE UPPER LEVEL JET...ON THE ORDER OF 110KTS
PUSHING INTO CENTRAL WYOMING. OUR WIND PRONE AREAS SHOULD BE CLOSE
TO HIGH WIND WARNING CRITERIA BY THAT TIME WITH BREEZY WINDS
ELSEWHERE. WILL GO AHEAD AND ISSUE A HIGH WIND WATCH FOR SATURDAY
AFTERNOON FOR THESE AREAS. LATER SHIFTS WILL NEED TO WATCH OTHER
AREAS AS LATEST MOS GUIDANCE IS SHOWING PRETTY STRONG WINDS AT
RAWLINS AND LARAMIE. CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME TO
ISSUE A WATCH FOR THOSE AREAS.
FRONT THEN LOOKS TO MOVE THROUGH SOUTHERN WYOMING BY SATURDAY
EVENING. MODELS DO DEPICT SOME PRETTY GOOD QPF OVER THE SNOWY AND
SIERRA MADRE RANGES AT THIS TIME AND WE WILL PROBABLY NEED A SNOW
ADVISORY FOR THOSE LOCATIONS SATURDAY NIGHT INTO SUNDAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 331 PM MDT FRI APR 12 2013
A STRONG UPPER LOW WILL SHIFT EAST OF THE FORECAST AREA ON
SUNDAY...WITH A COLD FRONT DROPPING SOUTH THROUGH THE AREA SUNDAY
EVENING. AHEAD OF THE FRONT...THE SFC PRESSURE GRADIENT WILL REMAIN
FAIRLY STRONG AS A SFC LOW DEEPENS AHEAD OF THE MAIN UPPER LOW
OVER THE NORTHERN PLAINS. SO EXPECTING MODERATE TO STRONG WESTERLY
WINDS ON SUNDAY WITH THE PRESSURE GRADIENT IN PLACE AHEAD OF THE
COLD FRONT. SUBSIDENCE IN THE WAKE OF THE DEPARTING SYSTEM ALONG
WITH THE DOWNSLOPE WINDS SHOULD KEEP CONDITIONS MOSTLY DRY...WITH
MAYBE A FEW LIGHT SNOW SHOWERS ALONG THE FRONT AS IT DROPS SOUTH
IN THE EVENING IN ADDITION TO THE WESTERN SLOPES OF THE MOUNTAINS
DUE TO UPSLOPE FORCING. THE FRONT LOOKS TO STALL OVER THE
MOUNTAINS...WITH NORTHEAST UPSLOPE FLOW STRENGTHENING SUNDAY NIGHT.
THE NEXT UPPER SYSTEM DIGGING INTO THE FOUR CORNERS REGION ON MONDAY
WILL INDUCE STRONG SFC PRESSURE FALLS OVER THE GREAT BASIN ON SUNDAY
NIGHT AND MONDAY. SO ON TOP OF THE POST-FRONTAL UPSLOPE FLOW
DEVELOPING ACROSS THE CWA...THE INCREASING PRESSURE GRADIENT FORCING
DUE TO THE INTENSIFYING LOW WILL DEEPEN THE UPSLOPE COMPONENT
EVEN FURTHER. IN ADDITION...STILL LOOKING AT MIDLEVEL ENERGY
EJECTING OUT AHEAD OF THE DEEPENING UPPER LOW AND MOVING OVER THE
FORECAST AREA MONDAY AND TUESDAY. ALL IN ALL...STILL LOOKING AT
THE POTENTIAL FOR YET ANOTHER PERIOD FOR MODERATE TO HEAVY SNOW
BEGINNING LATE SUNDAY NIGHT AND CONTINUING THROUGH EARLY
WEDNESDAY. WILL CONTINUE TO EMPHASIZE THIS SYSTEM IN THE HWO ALONG
WITH CONTINUED TREND FOR INCREASED POPS...ESPECIALLY ALONG THE
LARAMIE RANGE...CHEYENNE RIDGE...AND WESTERN MOUNTAINS.
MODELS DIFFER QUITE A BIT WITH MOVING THIS SYSTEM TO THE EAST
WEDNESDAY NIGHT AND THURSDAY. THE ECMWF IS SIGNIFICANTLY SLOWER THAN
THE GFS AND GEM MODELS...MEANING SNOW COULD LINGER LONGER THROUGH
WEDNESDAY NIGHT AND NORTHWEST WINDS WILL REMAIN STRONGER. HOWEVER...THE
CONSENSUS SHOWS THE IMPACTS FROM THE STORM WILL DIMINISH LATE ON
WEDNESDAY...WITH NORTHWEST FLOW RETURNING TO THE CWA FOR THURSDAY.
TEMPERATURES THROUGH THE PERIOD WILL TREND MILD ON SUNDAY...THEN
MUCH COLDER MONDAY THROUGH WEDNESDAY BEHIND THE COLD FRONT AND AS
THE UPPER LOW MOVES SLOWLY OVERHEAD. TEMPS WILL SLOWLY WARM FOR
THURSDAY BUT WILL DEPEND HEAVILY ON THE SNOWPACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 1153 PM MDT FRI APR 12 2013
AREA OF LOW STRATUS ACROSS FAR SOUTHEAST WYOMING AND THE SOUTHERN
NEBRASKA AT 06Z WILL MOVE EAST AND MOSTLY DISSIPATE BY 12Z. WEST
TO SOUTHWEST WINDS WILL INCREASE LATE TONIGHT INTO SATURDAY WITH
STRONG WINDS ALONG AND WEST OF THE LARAMIE RANGE. QUICK MOVING
SHORT WAVE WILL MOVE ACROSS THE AREA LATE TODAY INTO TONIGHT. SNOW
WILL OCCUR OVER THE MOUNTAINS OF SOUTHEAST WYOMING WITH MOST OF
THE SNOW OVER THE SNOWY AND SIERRA MADRE RANGES. MOUNTAINS WILL
BECOME OBSCURED IN THE SNOW.
&&
.FIRE WEATHER...
ISSUED AT 331 PM MDT FRI APR 12 2013
NO FIRE WEATHER CONCERNS AS CURRENT SNOW PACK CONTINUES TO MELT
AND FUELS ARE MOIST. WE DO HAVE A PRETTY WIDESPREAD WIND EVENT
SATURDAY AS A COLD FRONT APPROACHES WESTERN WYOMING. SOUTHWEST TO
WEST WINDS GUSTING IN EXCESS OF 50 MPH LOOK LIKELY FOR A LARGE
PART OF SOUTHEAST WYOMING SATURDAY. AFTERNOON HUMIDITIES SATURDAY
AND SUNDAY ONLY EXPECTED TO FALL INTO THE UPPER 20S AND LOW 30S.
UNSETTLED WEATHER RETURNS TO THE AREA THE BEGINNING OF NEXT WEEK
WITH ACCUMULATING SNOWS RETURNING TO MUCH OF THE AREA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR WYZ106-110-116-117.
NE...NONE.
&&
$$
UPDATE...HAHN
SHORT TERM...CLAYCOMB
LONG TERM...RJM
AVIATION...SML
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS MIAMI FL
208 AM EDT SAT APR 13 2013
.AVIATION...
OVERALL VFR CONDITIONS ARE FORECAST FOR THE NEXT 24 HOURS. HOWEVER,
PERIODS OF MVFR CEILINGS ARE POSSIBLE AROUND SHOWERS THAT WILL BE IN
THE VICINITY PARTICULAR OF TERMINALS IN MIAMI DADE THIS MORNING.
FOR THE MOMENT INCLUDED CLOUD DECKS UNDER 3 KFT GIVEN THE
UNCERTAINTY AND WILL AMEND AS NEEDED. LATER TODAY FORECAST SOUNDINGS
AND GUIDANCE IN GENERAL AGREE TSTMS WILL DEVELOP ACROSS INTERIOR
SECTIONS LIKELY AFFECTING VCNTY OF EAST COAST TERMINALS THROUGH
THE AFTERNOON AND EARLY EVENING HOURS. OUTFLOW BOUNDARIES COULD
ALSO HELP TRIGGER DEVELOPMENT CLOSE TO APF ALSO PLUS ANY ACTIVITY
MOVING IN FROM THE GULF, WHICH GIVEN UPR LEVEL TROUGH AND GULF
ACTIVITY IS VERY MUCH POSSIBLE. THEREFORE, VCSH FOR EAST COAST
TERMINALS THIS MORNING AND VCTS FOR AFTERNOON AND EVENING AS WELL
AS MENTION OF VCSH LATER THIS MORNING AND VCTS THIS AFTERNOON FOR
APF IS WARRANTED AT THIS TIME. SHOULD ANY TSTMS AFFECT ANY GIVEN
TERMINAL BRIEF PERIODS OF IFR CEILINGS AND VIS WILL BE LIKELY.
LIGHT SOUTHERLY WINDS THIS MORNING ALONG EAST COAST TERMINALS WILL
SHIFT FROM THE SE LATER TODAY AROUND 10 KNOTS. LIGHT SOUTH TO
SOUTHEAST WINDS AT APF WILL SHIFT FROM THE SW AROUND 10 KNOTS
SOMETIME AROUND NOON BEFORE BECOMING LIGHT AND VARIABLE DURING
EVENING HOURS.
&&
.PREV DISCUSSION... /ISSUED 950 PM EDT FRI APR 12 2013/
UPDATE...
THE FORECAST WAS UPDATED TO REFLECT THE DISSIPATION OF THE SHOWERS
AND THUNDERSTORMS ACROSS THE NORTHEASTERN SECTION OF PALM BEACH
COUNTY EARLIER THIS EVENING. A SLIGHT CHANCE OF SHOWERS WAS LEFT
IN THE FORECAST OVER NIGHT FOR ALL AREAS AND FOR THE OFF SHORE
GULF WATERS A SLIGHT CHANCE OF THUNDERSTORMS WAS INCLUDED.
RECENT RADAR IMAGERY INDICATES SHOWERS MOVING NORTHWARD ACROSS
THE FLORIDA STRAITS AND THE KEYS. AS THE COLD FRONT CONTINUES TO
MOVE INTO THE EASTERN GULF...THERE IS A LINE OF THUNDERSTORMS
AHEAD OF THE FRONT IN THE EASTERN GULF. THE RAPID REFRESH GUIDANCE
INDICATED THAT CONVECTION MAY REACH THE OFF SHORE GULF WATERS
AROUND 05Z WITH A SLIGHT CHANCE OF THUNDERSTORMS MENTIONED IN THE
FORECAST.
OTHERWISE...FORECAST IS ON TRACK FOR SATURDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS EXPECTED ACROSS THE REGION IN THE
AFTERNOON AND EARLY EVENING.
60
PREV DISCUSSION... /ISSUED 734 PM EDT FRI APR 12 2013/
AVIATION...
THE THUNDERSTORMS OVER THE PALM BEACH COUNTY AREA SHOULD
DISSIPATE BY 9 PM EDT THIS EVENING LEAVING ONLY SOME SHOWERS UNTIL
11 PM EDT. SO WILL CONTINUE THE VCTS FOR KPBI UNTIL 01Z AND THEN
VCSH UNTIL 03Z TONIGHT. REST OF THE TAF SITES ACROSS SOUTH FLORIDA
SHOULD REMAIN DRY TONIGHT. THE SHOWERS WILL COME BACK INTO PLAY AT
ALL OF THE TAF SITES BETWEEN 12Z AND 16Z ON SATURDAY...BEFORE
THUNDERSTORMS DEVELOP FOR THE AFTERNOON HOURS ON SATURDAY. SO WILL
HAVE A VCSH FROM 12Z UNTIL 16Z AND THEN VCTS AFTER 16Z SATURDAY
FOR ALL TAF SITES OVER SOUTH FLORIDA.
THE WIND SPEEDS TONIGHT AT ALL OF THE TAF SITES WILL DECREASE FROM
5 TO 10 KNOTS THIS EVENING TO LESS THAN 5 KNOTS AFTER 03Z MAINLY
FROM THE SOUTH TO SOUTHWEST DIRECTION. THE ONLY EXCEPTION TO THIS
IS AT KAPF WHERE THE WINDS WILL BE FROM THE SOUTHEAST DIRECTION.
THE WINDS WILL THEN INCREASE ON SATURDAY MORNING TO AROUND 10
KNOTS FROM THE SOUTHEAST...WITH KAPF TAF SITE SWINGING TO A
SOUTHWEST DIRECTION AFTER 16Z SATURDAY.
THE VIS SHOULD REMAIN IN THE VFR CONDITIONS TONIGHT INTO SATURDAY
AT ALL OF THE TAF SITES...EXCEPT FOR KPBI...KFLL...KFXE...AND KAPF
TAF SITES WITH THE CEILING TO FALL DOWN INTO THE MVFR CONDITIONS
BETWEEN 10Z AND 13Z TONIGHT. THE REASON FOR THIS IS FOR POSSIBLE
FOG DEVELOP OVER THE INTERIOR AREAS THAT COULD WORK INTO THESE TAF
SITES.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 230 PM EDT FRI APR 12 2013/
SHORT TERM (TONIGHT-SUNDAY NIGHT)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED PLENTY OF MID/UPPER
MOISTURE SPREADING NORTHEAST ACROSS THE FLORIDA PENINSULA WITHIN THE
SOUTHWEST UPPER FLOW AND A WEAK RIDGE AXIS EXTENDING NORTH OVER THE
BAHAMAS. THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTH AND SOUTHWEST ACROSS THE FLORIDA BIG BEND TO THE CENTRAL GULF
OF MEXICO WITH MOIST SOUTHERLY FLOW ACROSS THE FLORIDA PENINSULA
AHEAD OF IT. THE LATEST SHORT-RANGE FORECAST GUIDANCE REMAINS IN
GOOD AGREEMENT AND SHOWS THIS FRONTAL BOUNDARY CONTINUING EASTWARD
TOWARD AND INTO CENTRAL FLORIDA LATER THIS EVENING THROUGH TONIGHT
BEFORE STALLING AROUND OR JUST NORTH OF THE LAKE THROUGH THE DAY
SATURDAY. PLENTY OF DEEP LAYER MOISTURE AND SOUTHWEST DEEP LAYER
FLOW COMBINED WITH DAYTIME HEATING AND AFTERNOON SEA BREEZES WILL
SUPPORT SCATTERED SHOWERS AND STORMS THROUGH SATURDAY.
FOR THE REMAINDER OF THE AFTERNOON AND EVENING TODAY...THE BEST
CHANCE FOR THESE STORMS WILL REMAIN OVER THE NORTHERN AND EASTERN
SECTIONS OF THE AREA...ESPECIALLY OVER PALM BEACH/BROWARD COUNTIES.
THE LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THE CURRENT
TRENDS AND INDICATE THE AFTERNOON CONVECTION BECOMING CONCENTRATED
OVER THE EAST COAST METRO AND COASTAL LOCATIONS FROM BROWARD TO PALM
BEACH COUNTIES THROUGH SUNSET...THEN TRENDING DOWN THROUGH
MID/LATE-EVENING PERIODS. CONSIDERING THE MOIST PROFILES IN
PLACE...THE MAIN IMPACTS WITH THESE STORMS TODAY WILL BE WET
MICROBURSTS AND HEAVY RAINFALL. ADDITIONALLY...LOCALIZED FLOODING
CAN`T BE RULED OUT IN THE AREAS WHERE THIS ACTIVITY SETS UP.
ON SATURDAY...ANOTHER POTENTIALLY ACTIVE DAY IS ANTICIPATED DUE TO A
COMBINATION OF DEEP LAYER MOISTURE...DAYTIME HEATING/INSTABILITY AND
THE FRONTAL BOUNDARY IN THE VICINITY OF THE AREA. THIS BOUNDARY
ALONG WITH THE AFTERNOON SEA BREEZE WILL BE THE FOCUS AREAS FOR
AFTERNOON CONVECTION. THE LATEST MODEL GUIDANCE DOES INDICATE MORE
OF A SOUTHERLY FLOW UP TO 700MB THROUGH THIS PERIOD TOMORROW...WHICH
MAY RESULT IN THE AFTERNOON ACTIVITY BECOMING CONCENTRATED GENERALLY
OVER THE NORTHERN 1/3 OF THE FORECAST AREA OR AROUND THE LAKE
REGION. SATURDAY NIGHT THROUGH SUNDAY NIGHT...THIS BOUNDARY WILL
CONTINUE TO DIMINISH AND BEGIN TO LIFT BACK TO THE NORTH AS A
SHORTWAVE TROUGH LIFTS NORTHEAST OVER THE CENTRAL GULF COAST REGION.
SOUTHEAST LOW-LEVEL FLOW WILL BE EXPECTED SUNDAY WITH THE BEST
CHANCE OF AFTERNOON SHOWERS/STORMS OVER THE NWRN 1/3 OF THE FORECAST
AREA OR FROM NAPLES TO THE LAKE.
LONG TERM (MONDAY-FRIDAY)...
MOSTLY QUIET WEATHER CONDITIONS WILL BE EXPECTED AS DEEP LAYER
RIDGING REMAINS AS THE DOMINANT SYNOPTIC FEATURE THROUGH THE
MID-WEEK TIME FRAME. LATER IN THE WEEK...THE MODELS REMAIN IN DECENT
AGREEMENT...OUTSIDE OF SOME MINOR TIMING DIFFERENCES...AND GENERALLY
SHOW ANOTHER FRONTAL BOUNDARY APPROACHING AND MOVING OVER THE STATE.
IF THE MODELS REMAIN PERSISTENT WITH THIS FEATURE OVER THE WEEKEND
AND INTO THE UPCOMING WEEK...EXPECT THE EXTENDED RANGE RAINFALL
CHANCES TO STEADILY INCREASE AS CONFIDENCE RISES. OTHERWISE...QUIET
CONDITIONS WILL CONTINUE THROUGH THE WEEK WITH TEMPERATURES
REMAINING ABOVE NORMAL WITH THE MOIST SOUTHERLY FLOW IN PLACE. THE
BEST CHANCE FOR AFTERNOON SHOWERS OR STORMS WILL REMAIN INLAND FROM
NAPLES TO THE LAKE.
MARINE...
MODERATE SOUTHERLY WINDS WILL PERSIST INTO THE WEEKEND AS A COLD
FRONT APPROACHES AND STALLS JUST NORTH OF THE SOUTH FLORIDA WATERS
SATURDAY. SCATTERED SHOWERS AND A FEW STORMS WILL BE EXPECTED
THROUGH SATURDAY AS THE FRONT APPROACHES AND STALLS JUST NORTH OF
THE AREA. THIS FRONTAL BOUNDARY WILL DIMINISH OVER THE WEEKEND AND
INTO THE UPCOMING WEEK WITH HIGH PRESSURE EXPECTED TO BUILD BACK
OVER THE AREA NEXT WEEK.
FIRE WEATHER...
PLENTY OF MOISTURE ALONG WITH INCREASING RAIN CHANCES WILL PRECLUDE
ANY CHANCE FOR CRITICAL FIRE WEATHER CONDITIONS THROUGH THE WEEKEND
AS A COLD FRONT APPROACHES AND STALLS AROUND THE LAKE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 71 83 74 / 50 20 20 10
FORT LAUDERDALE 85 73 84 75 / 50 20 20 10
MIAMI 86 72 84 75 / 40 20 20 10
NAPLES 83 70 86 70 / 40 20 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...10/CD
AVIATION/RADAR...52/PS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
609 AM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 608 AM MDT SAT APR 13 2013
UPDATED FOR A DENSE FOG ADVISORY FOR HITCHCOCK AND RED WILLOW.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 440 AM MDT SAT APR 13 2013
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION INTO THE
BEGINNING OF NEXT WEEK...FIRE WEATHER CONCERNS TODAY...AND WINDS
TODAY/TONIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN
FROM THE PACIFIC ACROSS NORTH AMERICA INTO THE ATLANTIC. CONTINUES TO
SHOW AN AMPLIFIED AND BLOCKY PATTERN FROM THE PACIFIC INTO EASTERN
NORTH AMERICA. VERY STRONG AND COLD SYSTEM IS DIGGING INTO SOUTHWEST
CANADA AND THE PACIFIC NORTHWEST. CURRENTLY WEST NORTHWEST TO
NORTHWEST RESIDES OVER THE REGION.
AT JET LEVEL...THE MODELS TENDED TO NOT HAVE THE JET AXIS THAT IS
PUNCHING INTO THE PACIFIC NORTHWEST TOO FAR NORTH AND EAST. THE NAM
AND GFS WERE DOING BEST ON THIS SEGMENT. THE MODELS TENDED TO HAVE
THE HEIGHT FIELD TOO FAR SOUTH AND EAST. OVERALL THE GFS...UKMET
AND CANADIAN WERE DOING THE BEST. THE RUC AND ECMWF WERE DOING
SLIGHTLY BETTER THAN THE NAM ON THE SURFACE WIND AND PRESSURE
FIELD. GFS AND CANADIAN WERE DOING A LITTLE BETTER THAN THE NAM ON
THE LOW LEVEL THERMAL FIELD.
PER THE INITIAL ANALYSIS AND THE PATTERN WE ARE IN...CHOSE THE
MID/UPPER LEVEL SOLUTIONS THAT WERE FURTHER SOUTH AND FASTER
INITIALLY FOLLOWED BY BEING FURTHER SOUTH AND WEST WITH THE INCOMING
LATER.
TODAY/TONIGHT...FIRST WHAT TO DO WITH THE FOG. MODELS...EVEN
MESOSCALE...HAVING DIFFICULTY GRABBING ONTO THE FOG. WHAT IS
COMPLICATING THINGS IS A CLOUD DECK ABOVE THIS THAT HAS BEEN CAUSING
VARIABILITY IN THE FOG FIELD. BASED ON LATEST TRENDS...CHOSE TO GO
AREAS OF FOG IN THE NORTHERN AND WESTERN SECTIONS AND PATCHY
ELSEWHERE. AS THE SUN COMES UP AND THE WINDS BEGIN TO INCREASE...
THE FOG SHOULD BURN OFF.
CROSS MOUNTAIN FLOW WILL CAUSE LEE TROUGH TO DEVELOP RAPIDLY. 3 HOUR
PRESSURE FALLS AND GRADIENT WOULD INDICATE AT LEAST BREEZY POSSIBLY
A LITTLE HIGHER CONDITIONS. THIS WILL HAVE AN AFFECT ON THE FIRE
WEATHER CONDITIONS. REFER TO THAT BELOW. GUIDANCE HAS BEEN COOL THE
LAST FEW DAYS AND NOT BY A LITTLE BIT...EVEN WITH CLOUDS AROUND. SO
TOOK THE WARMEST BIAS AND ADJUSTED IT WITH SOME BIAS/CHANGE IN
FORECAST 850 MB TEMPERATURE TO ARRIVE AT THE HIGHS.
MAIN JET AXIS STAYS NORTH AND WEST OF THE AREA. ALSO MAIN MID LEVEL
AND PV ANOMALY ARE STILL NORTH OF THE AREA. ALSO SOUNDINGS HAVE TOO
MUCH OF A DRY LAYER. THERE IS SOME SURFACE BASED INSTABILITY IN THE
AFTERNOON BUT THAT IS CAPPED. THERE IS NO ELEVATED INSTABILITY PLUS
IT IS CAPPED AS WELL EVEN IF THERE WAS ANY. SO WILL KEEP THIS
PERIOD DRY. HOWEVER...SOME KIND OF PRECIPITATION COULD GET CLOSE TO
THE FAR NORTHERN SECTION. CLOUD COVER AND WESTERLY WINDS/WARM AIR
ADVECTION IN ADVANCE OF THE COLD FRONT THAT ARRIVES LATER TONIGHT
WILL KEEP THE MINS RATHER MILD. THEY MAY NOT BE WARM ENOUGH. RATHER
SUNDAY/SUNDAY NIGHT...RATHER STRONG 3 HOUR PRESSURE RISE WILL CAUSE
BREEZY TO WINDY CONDITIONS BEHIND THE FRONT IN THE MORNING. LEFT
FRONT QUADRANT OF STRONG JET BEGINS TO AFFECT THE AREA AT THE
BEGINNING OF THE DAY AND THEN STARTS GRADUALLY LIFTING TO THE NORTH
AT THE END OF THE DAY. MID LEVEL COLD AIR ADVECTION/BAROCLINIC ZONE
ALONG WITH RATHER STRONG PV ANOMALY PUSHES ACROSS THE AREA AT THE
SAME WITH THE BEST LIFT AND MOISTURE OVER THE NORTHERN PORTION OF THE
AREA. SO EXPANDED POPS THROUGH THE DAY WITH THE HIGHEST IN THE
NORTHERN PORTION. COMBINATION OF CLOUD COVER/PRECIPITATION AND COLD
AIR ADVECTION WILL TEMPERATURES FROM RISING TOO MUCH AND WENT A
LITTLE BELOW GUIDANCE.
RIGHT REAR QUADRANT IS OVER THE AREA DURING THE NIGHT AND GETS
BETTER AS THE NIGHT WHERES ON AND AS THE MID LEVEL BAROCLINIC ZONE
REMAINS OVER THE AREA. PLUS ANOTHER SHORTWAVE TROUGH APPROACHES BY
LATER IN THE NIGHT. CURRENT FORECAST CAPTURES THIS SCENARIO NICELY
AND DID NOT CHANGE IT WITH GREATEST CHANCE OF PRECIPITATION
WILL BE IN THE NORTH WITH A CHANGEOVER OR MIXTURE OF PHASE EXPECTED
IN THE WEST.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF JET/JET AXIS REMAINS
OVER OR NEAR THE NORTHWEST HALF OF THE AREA THROUGH THE PERIOD.
LOW LEVEL UPSLOPE INCREASES THROUGH THE DAY AS STRONG MID LEVEL
SOUTHWEST FLOW ALOFT CAUSES LEE TROUGH TO STRENGTHEN. ALSO A COUPLE
OF SHORTWAVE TROUGHS MOVE THROUGH IN THIS FLOW. ALMOST EVERY
PARAMETER OF THE FORECAST FOR THIS PERIOD WILL BE PROBLEMATIC.
BECAUSE OF THE PROXIMITY OF THE JET AND MID LEVEL LIFT...KEPT THE
HIGHEST POPS IN THAT SECTION. HOWEVER...THERE IS A SHARP CUTOFF
BETWEEN A LOT OF CLOUDS/NO CLOUDS AND PRECIPITATION/NO
PRECIPITATION. SO ANY SUBTLE SHIFT NORTH OR SOUTH WILL GREATLY
AFFECT EVERY PARAMETER OF THE FORECAST. SO MADE ONLY MINOR
MODIFICATIONS. IF MODELS CONTINUE THE CURRENT TRENDS...THE
NORTHWEST HALF...ESPECIALLY THE CORNER...WILL NEED TO HAVE POPS
RAMPED UP CONSIDERABLY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT APR 13 2013
AN UPPER LEVEL TROUGH WILL DEEPEN OVER THE WESTERN CONUS TO START
OUT THE PERIOD. THE TROUGH WILL LINGER THERE THROUGH WEDNESDAY
BEFORE MOVING TOWARD THE AREA. WHILE THE UPPER LEVEL TROUGH REMAINS
SEMI STATIONARY LIFT FROM THE TROUGH WILL MOVE OVER THE AREA AND THE
ENVIRONMENT WILL BECOME SATURATED. THE BEST LIFT WILL MOVE OVER THE
AREA TUESDAY NIGHT AND WEDNESDAY. HAVE THE BEST PRECIP. CHANCES FOR
TUESDAY NIGHT DUE TO THE STRONGER FRONTOGENESIS OVER THE AREA
COMPARED TO WEDNESDAY.
ON WEDNESDAY THE MID LEVEL TROUGH MOVES OVER THE AREA AND WINDS
INCREASE AS AN ARCTIC COLD FRONT MOVES THROUGH. THE GUSTY WINDS MAY
CAUSE PATCHY BLOWING SNOW. DURING THE EVENING THE LIFT BEGINS TO
DECLINE AS THE MID LEVEL TROUGH MOVES TO THE EAST AND THE UPPER
LEVEL TROUGH AXIS BEGINS TO MOVE THROUGH THE AREA. PRECIP. COMES TO
AN END THURSDAY MORNING AS THE LAST OF THE LINGERING LIFT FROM THE
MID LEVEL TROUGH MOVES OUT OF THE AREA.
THERE IS STILL SOME UNCERTAINTY AS TO WHAT THE PHASE OF THE PRECIP.
WILL BE FOR PORTIONS OF THE FORECAST SINCE MODELS DISAGREE WITH THE
AMOUNT OF SATURATION ABOVE THE -10C LEVEL...SO HAVE CHOSEN TO GO WITH
A RAIN/SNOW MIX AT THIS TIME WHICH WILL NEGATIVELY AFFECT FORECASTED
SNOWFALL AMOUNTS. IF TEMPERATURES COOL FURTHER SNOW-TO-LIQUID
RATIOS WILL INCREASE WHICH WILL ALSO CAUSE THE SNOWFALL AMOUNTS TO
INCREASE. CURRENTLY HAVE 1-4 INCHES FORECAST ACROSS THE AREA...WITH
THE HIGHER AMOUNTS OVER THE WESTERN PART OF THE AREA WHERE THE
BETTER LIFT WILL BE.
TEMPERATURES FOR THE PERIOD WILL BE BELOW NORMAL...BUT LOW
TEMPERATURES WILL NEAR NORMAL VALUES BY THE END OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 552 AM MDT SAT APR 13 2013
INITIAL CONCERN WILL BE FOG AND STRATUS. AT THIS TIME LIFR
CONDITIONS ARE OCCURRING AT KMCK AND ARE EXPECTED TO CONTINUE
UNTIL 15Z. AT KGLD...STRATUS AND FOG ARE NOT CURRENTLY AFFECTING
THE SITE BUT ARE NOT THAT FAR AWAY AND WILL HAVE THE POTENTIAL TO
AFFECT THE SITES WITH MVFR CONDITIONS. AFTER THE FOG AND STRATUS
ARE GONE GUSTY SOUTHERLY WINDS ARE EXPECTED UNTIL EARLY EVENING.
THUNDERSTORMS LATER THIS EVENING AND OVERNIGHT APPEAR TO STAY
NORTH AT KMCK SO NO MENTION WAS MADE IN THE TAF. AFTER 06Z A
STRONG COLD FRONT WILL MOVE THROUGH AND CREATE GUSTY NORTHWEST
WINDS.
&&
.FIRE WEATHER...
ISSUED AT 440 AM MDT SAT APR 13 2013
CRITICAL FIRE WEATHER CONDITIONS WILL BE CLOSE IN CHEYENNE AND
KIT CARSON COUNTIES...ESPECIALLY THE WESTERN SECTIONS. CONDITIONS
WILL BE VERY CLOSE. IF THIS MORNINGS CLOUD COVER IS SLOW TO BURN
OFF THEN MIXING WILL BE SLOWER TO COMMENCE AS WELL. AT THIS TIME...
IT WILL BE CLOSE IF THE 3 HOUR REQUIREMENT WILL BE REALIZED. AT THIS
TIME CHOSE TO NOT ISSUE A HIGHLIGHT. BUT WILL CONTINUE TO MONITOR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR NEZ080-081.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
557 AM MDT SAT APR 13 2013
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 440 AM MDT SAT APR 13 2013
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION INTO THE
BEGINNING OF NEXT WEEK...FIRE WEATHER CONCERNS TODAY...AND WINDS
TODAY/TONIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN
FROM THE PACIFIC ACROSS NORTH AMERICA INTO THE ATLANTIC. CONTINUES TO
SHOW AN AMPLIFIED AND BLOCKY PATTERN FROM THE PACIFIC INTO EASTERN
NORTH AMERICA. VERY STRONG AND COLD SYSTEM IS DIGGING INTO SOUTHWEST
CANADA AND THE PACIFIC NORTHWEST. CURRENTLY WEST NORTHWEST TO
NORTHWEST RESIDES OVER THE REGION.
AT JET LEVEL...THE MODELS TENDED TO NOT HAVE THE JET AXIS THAT IS
PUNCHING INTO THE PACIFIC NORTHWEST TOO FAR NORTH AND EAST. THE NAM
AND GFS WERE DOING BEST ON THIS SEGMENT. THE MODELS TENDED TO HAVE
THE HEIGHT FIELD TOO FAR SOUTH AND EAST. OVERALL THE GFS...UKMET
AND CANADIAN WERE DOING THE BEST. THE RUC AND ECMWF WERE DOING
SLIGHTLY BETTER THAN THE NAM ON THE SURFACE WIND AND PRESSURE
FIELD. GFS AND CANADIAN WERE DOING A LITTLE BETTER THAN THE NAM ON
THE LOW LEVEL THERMAL FIELD.
PER THE INITIAL ANALYSIS AND THE PATTERN WE ARE IN...CHOSE THE
MID/UPPER LEVEL SOLUTIONS THAT WERE FURTHER SOUTH AND FASTER
INITIALLY FOLLOWED BY BEING FURTHER SOUTH AND WEST WITH THE INCOMING
LATER.
TODAY/TONIGHT...FIRST WHAT TO DO WITH THE FOG. MODELS...EVEN
MESOSCALE...HAVING DIFFICULTY GRABBING ONTO THE FOG. WHAT IS
COMPLICATING THINGS IS A CLOUD DECK ABOVE THIS THAT HAS BEEN CAUSING
VARIABILITY IN THE FOG FIELD. BASED ON LATEST TRENDS...CHOSE TO GO
AREAS OF FOG IN THE NORTHERN AND WESTERN SECTIONS AND PATCHY
ELSEWHERE. AS THE SUN COMES UP AND THE WINDS BEGIN TO INCREASE...
THE FOG SHOULD BURN OFF.
CROSS MOUNTAIN FLOW WILL CAUSE LEE TROUGH TO DEVELOP RAPIDLY. 3 HOUR
PRESSURE FALLS AND GRADIENT WOULD INDICATE AT LEAST BREEZY POSSIBLY
A LITTLE HIGHER CONDITIONS. THIS WILL HAVE AN AFFECT ON THE FIRE
WEATHER CONDITIONS. REFER TO THAT BELOW. GUIDANCE HAS BEEN COOL THE
LAST FEW DAYS AND NOT BY A LITTLE BIT...EVEN WITH CLOUDS AROUND. SO
TOOK THE WARMEST BIAS AND ADJUSTED IT WITH SOME BIAS/CHANGE IN
FORECAST 850 MB TEMPERATURE TO ARRIVE AT THE HIGHS.
MAIN JET AXIS STAYS NORTH AND WEST OF THE AREA. ALSO MAIN MID LEVEL
AND PV ANOMALY ARE STILL NORTH OF THE AREA. ALSO SOUNDINGS HAVE TOO
MUCH OF A DRY LAYER. THERE IS SOME SURFACE BASED INSTABILITY IN THE
AFTERNOON BUT THAT IS CAPPED. THERE IS NO ELEVATED INSTABILITY PLUS
IT IS CAPPED AS WELL EVEN IF THERE WAS ANY. SO WILL KEEP THIS
PERIOD DRY. HOWEVER...SOME KIND OF PRECIPITATION COULD GET CLOSE TO
THE FAR NORTHERN SECTION. CLOUD COVER AND WESTERLY WINDS/WARM AIR
ADVECTION IN ADVANCE OF THE COLD FRONT THAT ARRIVES LATER TONIGHT
WILL KEEP THE MINS RATHER MILD. THEY MAY NOT BE WARM ENOUGH. RATHER
SUNDAY/SUNDAY NIGHT...RATHER STRONG 3 HOUR PRESSURE RISE WILL CAUSE
BREEZY TO WINDY CONDITIONS BEHIND THE FRONT IN THE MORNING. LEFT
FRONT QUADRANT OF STRONG JET BEGINS TO AFFECT THE AREA AT THE
BEGINNING OF THE DAY AND THEN STARTS GRADUALLY LIFTING TO THE NORTH
AT THE END OF THE DAY. MID LEVEL COLD AIR ADVECTION/BAROCLINIC ZONE
ALONG WITH RATHER STRONG PV ANOMALY PUSHES ACROSS THE AREA AT THE
SAME WITH THE BEST LIFT AND MOISTURE OVER THE NORTHERN PORTION OF THE
AREA. SO EXPANDED POPS THROUGH THE DAY WITH THE HIGHEST IN THE
NORTHERN PORTION. COMBINATION OF CLOUD COVER/PRECIPITATION AND COLD
AIR ADVECTION WILL TEMPERATURES FROM RISING TOO MUCH AND WENT A
LITTLE BELOW GUIDANCE.
RIGHT REAR QUADRANT IS OVER THE AREA DURING THE NIGHT AND GETS
BETTER AS THE NIGHT WHERES ON AND AS THE MID LEVEL BAROCLINIC ZONE
REMAINS OVER THE AREA. PLUS ANOTHER SHORTWAVE TROUGH APPROACHES BY
LATER IN THE NIGHT. CURRENT FORECAST CAPTURES THIS SCENARIO NICELY
AND DID NOT CHANGE IT WITH GREATEST CHANCE OF PRECIPITATION
WILL BE IN THE NORTH WITH A CHANGEOVER OR MIXTURE OF PHASE EXPECTED
IN THE WEST.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF JET/JET AXIS REMAINS
OVER OR NEAR THE NORTHWEST HALF OF THE AREA THROUGH THE PERIOD.
LOW LEVEL UPSLOPE INCREASES THROUGH THE DAY AS STRONG MID LEVEL
SOUTHWEST FLOW ALOFT CAUSES LEE TROUGH TO STRENGTHEN. ALSO A COUPLE
OF SHORTWAVE TROUGHS MOVE THROUGH IN THIS FLOW. ALMOST EVERY
PARAMETER OF THE FORECAST FOR THIS PERIOD WILL BE PROBLEMATIC.
BECAUSE OF THE PROXIMITY OF THE JET AND MID LEVEL LIFT...KEPT THE
HIGHEST POPS IN THAT SECTION. HOWEVER...THERE IS A SHARP CUTOFF
BETWEEN A LOT OF CLOUDS/NO CLOUDS AND PRECIPITATION/NO
PRECIPITATION. SO ANY SUBTLE SHIFT NORTH OR SOUTH WILL GREATLY
AFFECT EVERY PARAMETER OF THE FORECAST. SO MADE ONLY MINOR
MODIFICATIONS. IF MODELS CONTINUE THE CURRENT TRENDS...THE
NORTHWEST HALF...ESPECIALLY THE CORNER...WILL NEED TO HAVE POPS
RAMPED UP CONSIDERABLY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT APR 13 2013
AN UPPER LEVEL TROUGH WILL DEEPEN OVER THE WESTERN CONUS TO START
OUT THE PERIOD. THE TROUGH WILL LINGER THERE THROUGH WEDNESDAY
BEFORE MOVING TOWARD THE AREA. WHILE THE UPPER LEVEL TROUGH REMAINS
SEMI STATIONARY LIFT FROM THE TROUGH WILL MOVE OVER THE AREA AND THE
ENVIRONMENT WILL BECOME SATURATED. THE BEST LIFT WILL MOVE OVER THE
AREA TUESDAY NIGHT AND WEDNESDAY. HAVE THE BEST PRECIP. CHANCES FOR
TUESDAY NIGHT DUE TO THE STRONGER FRONTOGENESIS OVER THE AREA
COMPARED TO WEDNESDAY.
ON WEDNESDAY THE MID LEVEL TROUGH MOVES OVER THE AREA AND WINDS
INCREASE AS AN ARCTIC COLD FRONT MOVES THROUGH. THE GUSTY WINDS MAY
CAUSE PATCHY BLOWING SNOW. DURING THE EVENING THE LIFT BEGINS TO
DECLINE AS THE MID LEVEL TROUGH MOVES TO THE EAST AND THE UPPER
LEVEL TROUGH AXIS BEGINS TO MOVE THROUGH THE AREA. PRECIP. COMES TO
AN END THURSDAY MORNING AS THE LAST OF THE LINGERING LIFT FROM THE
MID LEVEL TROUGH MOVES OUT OF THE AREA.
THERE IS STILL SOME UNCERTAINTY AS TO WHAT THE PHASE OF THE PRECIP.
WILL BE FOR PORTIONS OF THE FORECAST SINCE MODELS DISAGREE WITH THE
AMOUNT OF SATURATION ABOVE THE -10C LEVEL...SO HAVE CHOSEN TO GO WITH
A RAIN/SNOW MIX AT THIS TIME WHICH WILL NEGATIVELY AFFECT FORECASTED
SNOWFALL AMOUNTS. IF TEMPERATURES COOL FURTHER SNOW-TO-LIQUID
RATIOS WILL INCREASE WHICH WILL ALSO CAUSE THE SNOWFALL AMOUNTS TO
INCREASE. CURRENTLY HAVE 1-4 INCHES FORECAST ACROSS THE AREA...WITH
THE HIGHER AMOUNTS OVER THE WESTERN PART OF THE AREA WHERE THE
BETTER LIFT WILL BE.
TEMPERATURES FOR THE PERIOD WILL BE BELOW NORMAL...BUT LOW
TEMPERATURES WILL NEAR NORMAL VALUES BY THE END OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 552 AM MDT SAT APR 13 2013
INITIAL CONCERN WILL BE FOG AND STRATUS. AT THIS TIME LIFR
CONDITIONS ARE OCCURRING AT KMCK AND ARE EXPECTED TO CONTINUE
UNTIL 15Z. AT KGLD...STRATUS AND FOG ARE NOT CURRENTLY AFFECTING
THE SITE BUT ARE NOT THAT FAR AWAY AND WILL HAVE THE POTENTIAL TO
AFFECT THE SITES WITH MVFR CONDITIONS. AFTER THE FOG AND STRATUS
ARE GONE GUSTY SOUTHERLY WINDS ARE EXPECTED UNTIL EARLY EVENING.
THUNDERSTORMS LATER THIS EVENING AND OVERNIGHT APPEAR TO STAY
NORTH AT KMCK SO NO MENTION WAS MADE IN THE TAF. AFTER 06Z A
STRONG COLD FRONT WILL MOVE THROUGH AND CREATE GUSTY NORTHWEST
WINDS.
&&
.FIRE WEATHER...
ISSUED AT 440 AM MDT SAT APR 13 2013
CRITICAL FIRE WEATHER CONDITIONS WILL BE CLOSE IN CHEYENNE AND
KIT CARSON COUNTIES...ESPECIALLY THE WESTERN SECTIONS. CONDITIONS
WILL BE VERY CLOSE. IF THIS MORNINGS CLOUD COVER IS SLOW TO BURN
OFF THEN MIXING WILL BE SLOWER TO COMMENCE AS WELL. AT THIS TIME...
IT WILL BE CLOSE IF THE 3 HOUR REQUIREMENT WILL BE REALIZED. AT THIS
TIME CHOSE TO NOT ISSUE A HIGHLIGHT. BUT WILL CONTINUE TO MONITOR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
410 AM EDT SAT APR 13 2013
.SYNOPSIS...
LOW PRESSURE AND ASSOCIATED COLD FRONT IS MOVING AWAY FROM THE AREA.
HIGH PRESSURE WILL BUILD OVER THE AREA TODAY AND CONTINUE THROUGH
THIS WEEKEND. THE HIGH WILL MOVE OFF THE COAST EARLY NEXT WEEK AND A
WARM FRONT WILL STALL OVER THE REGION DURING THIS TIME. A STRONGER
FRONT WILL APPROACH FROM THE WEST LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH 11Z SAT...LOW PRESSURE CENTER THAT WAS NEARLY STATIONARY LAST
EVENING OVER S-CNTRL VIRGINIA FINALLY MOVED NE AND OFF THE EASTERN
SEABOARD AND CONTINUES MOVING AWAY FROM THE AREA. THIS HAS ALLOWED A
COLD FRONT TO PUSH ACROSS THE AREA...OVERTAKING THE BACKDOOR COLD
FRONT THAT HAD SET UP A MARITIME AIRMASS OVER THE NE PORTION OF THE
CWA EARLIER. BEHIND THE COLD FRONT...A SURGE IN SURFACE WINDS WAS
ASSOCIATED WITH A RISING PRESSURE SURGE AS THIS LOW DEPARTED. SKIES
HAVE GENERALLY CLEARED AND VISIBILITIES IMPROVED DRAMATIC BEHIND THE
COLD FRONT. THE PRESSURE GRADIENT IS NOW IN THE PROCESS OF RELAXING
ALLOWING SURFACE WINDS TO DECREASE FOR THE REST OF THE OVERNIGHT.
EARLIER SHOWER ACTIVITY ALONG PORTIONS OF THE CENTRAL MD CHES BAY
ENDED AS WELL. WINDS SHOULD BACK FROM NORTHERLY TO MORE WESTERLY BY
DAYBREAK SATURDAY.
TODAY...HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE MID-ATLANTIC
REGION TODAY. DRY WEATHER WITH MOSTLY SUNNY SKIES WILL PREVAIL. BUT
TEMPERATURES ALOFT AT 850 HPA WITH COLD ADVECTION WILL BE 6-8 DEGC
COOLER THAN YESTERDAY. IN AREAS THAT WERE NOT IN YESTERDAYS MARITIME
WEDGE OF COOL AIR...MAX TEMPS THIS AFTERNOON WILL BE 10-15 DEGF
COOLER THAN YESTERDAY. IN THOSE AREA THAT WERE IN THE COOL
WEDGE...MAX TEMPS WILL ACTUALLY BE A TAD WARMER THAN YESTERDAY...
OWING TO AMPLE SUNSHINE. OVER TEMPERATURES TODAY WILL BE NEAR OR
EVEN SLIGHTLY ABOVE SEASONAL NORMALS. SCATTERED DIURNALLY DRIVEN
CUMULUS WILL IMPACT MOST AREAS BETWEEN ABOUT NOON AND 5 PM. DURING
THE MORNING WINDS WILL BE NORTHWEST OR WEST. TYPICALLY WITH WESTERLY
WINDS...A LEE TROUGH WILL DEVELOP ALONG THE APPALACHIANS...AND THIS
IS SHOWN IN THE 00Z NAM MODEL NICELY. THUS...WINDS MORE WESTERLY
WEST OF THE BLUE RIDGE...AND BACKED MORE TO THE SOUTHWEST EAST OF
THE BLUE RIDGE. TEMPERATURES ON THE NORTH AND WEST SIDES OF THE
TROUGH WILL BE SLIGHTLY COOLER...EAST AND SOUTH SLIGHTLY WARMER.
TONIGHT...EARLIER LOW PRESSURE TROUGH WILL MOVE EAST OF THE AREA
DURING THE EVENING...AS SHOWN IN 00Z NAM GUIDANCE...WITH WEAK HIGH
PRESSURE BUILDING INTO THE AREA DURING THE OVERNIGHT. WINDS LIGHT
OVERNIGHT WITH A WEST TO NW COMPONENT INDICATED IN GUIDANCE.
TEMPERATURES EXPECTED TO BE SEASONAL NORMALS AS WELL AND LEANED MORE
ON THE MET GUIDANCE VALUES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
SURFACE HIGH PRESSURE BUILDS ACROSS THE MIDDLE ATLANTIC ON SUNDAY
AND OFF THE COAST BY SUNDAY NIGHT. MILDER TEMPERATURES IN THE 60S TO
LOWER 70S CAN BE EXPECTED FOR AFTERNOON HIGH TEMPERATURES. THE
WARMEST CONDITIONS WILL BE FOUND ACROSS CENTRAL VIRGINIA...COOLEST
NEAR THE MASON DIXON LINE.
LOW LEVEL WINDS WILL SHIFT TO THE EAST AND SOUTHEAST LATER SUNDAY
INTO MONDAY AS HIGH PRESSURE REMAINS OFF THE COAST. THIS WILL HELP
DRAW MOISTURE INTO THE FORECAST AREA. MOSTLY CLOUDY CONDITIONS ARE
EXPECTED DURING THE DAY. TEMPERATURES ARE STILL EXPECTED TO BE
SLIGHTLY ABOVE NORMAL. AN AREA OF LOW PRESSURE WILL TRACK NORTHEAST
ALONG THE CAROLINA COASTLINE DURING THIS TIME FRAME. THE BULK OF THE
RAINFALL ASSOCIATED WITH THIS FEATURE WILL REMAIN TO OUR SOUTH YET
SOME LIGHT RAIN/SHOWERS MAY STILL BE POSSIBLE OVER SOUTHERN PORTIONS
OF THE CWFA. RAINFALL AMOUNTS WILL BE LIGHT. MOSTLY CLOUDY SKIES AND
LOW LEVEL MOISTURE WILL HELP KEEP OVERNIGHT TEMPERATURES ON THE MILD
SIDE MONDAY NIGHT INTO EARLY TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
TEMPERATURES WILL MODERATE WELL INTO THE 70S TUESDAY AND APPROACHING
THE UPPER 70S TO LOWER 80S ON WEDNESDAY. ANOTHER FRONTAL BOUNDARY
WILL GRADUALLY SAG SOUTH INTO AT LEAST THE NORTHERN EXTENT OF OUR
FORECAST AREA BY MID WEEK. THIS WILL BRING CHANCES FOR SCATTERED
SHOWERS AND THUNDERSTORMS ESPECIALLY NEAR THE MASON DIXON LINE BUT
LOCATION WILL BE DEPENDENT ON HOW FAR SOUTH THE BOUNDARY CAN SINK. A
STRONGER COLD FRONT IS PROGGED TO PUSH EAST ACROSS THE FORECAST AREA
LATE THURSDAY INTO FRIDAY BRINGING WITH IT MORE WIDESPREAD COVERAGE
OF SHOWERS AND ISOLATED THUNDERSTORMS. WILL GO LIKELY ON POPS FOR
THIS EVENT.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT VFR CONDITIONS THROUGH SUNDAY. EARLIER NORTHERLY WIND SURGE
HAS PASSED...AND EXPECT WINDS TO BE FROM A NW TO WEST COMPONENT
TODAY.
MOSTLY VFR EXPECTED SUNDAY FOLLOWED BY DECREASING CIGS AND VSBYS
MONDAY. SOME LIGHT RAIN/SHOWERS COULD IMPACT THE TERMINALS MONDAY.
ANOTHER FRONTAL BOUNDARY MAY SAG SOUTH ACROSS THE MASON DIXON LINE
FOR THE MIDDLE OF THE WEEK. A MORE SUBSTANTIAL FRONTAL PASSAGE WILL
OCCUR LATE THURSDAY OR FRIDAY WITH WIDESPREAD SHOWERS/ISOLATED
THUNDERSTORMS EXPECTED.
&&
.MARINE...
UPDATE...ON SECOND THOUGHT FOR TODAY...HAVE DECIDED AFTER LOOKING
AT MORE GUIDANCE TO CANCEL THE SMALL CRAFT ADVISORY WE HAD UP FOR
THIS AFTERNOON. THE 00Z NAM/GFS BOTH SHOW A LEE TROUGH WHICH WILL
HELP KNOCK DOWN WINDS. LATEST RAP AND 3KM HRRR ALSO SHOW RATHER
CHAOTIC WINDS ON THE WATERS FOR TODAY. SO WILL DROP MENTION OF THE
AFTERNOON SCA IN THE 430 UPDATE. THIS ALSO GOES ALONG WITH
DROPPING THE SCA THAT HAD BEEN UP THROUGH 6AM.
HIGH PRES BUILDS IN TONIGHT...AND THE PRESSURE GRADIENT WILL
RELAX...DO NOT EXPECT ANY SCA HEADLINES FOR TONIGHT.
WINDS WILL LIKELY REMAIN BELOW SCA LEVELS SUNDAY BUT APPROACH
CRITERIA MONDAY MORNING AS SOUTHERLY CHANNELING DEVELOPS. WINDS
REMAIN BELOW SCA LEVELS THROUGH MID WEEK FOLLOWED BY INCREASING
SOUTHERLY FLOW AHEAD OF THE NEXT FRONTAL PASSAGE LATE IN THE WEEK.
SMALL CRAFT CONDITIONS WILL LIKELY RETURN TO THE WATERS THURSDAY
AND ESPECIALLY FRIDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SMZ
SHORT TERM...KRW
LONG TERM...KRW
AVIATION...KRW/SMZ
MARINE...KRW/SMZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
738 AM EDT SAT APR 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT APR 13 2013
LAKE ENHANCEMENT HAVING A TOUGH TIME STARTING EARLY THIS
MORNING...EXCEPT FOR A BAND JUST WEST OF IWD. SEEMS LIKE THE MAIN
PROBLEM WITH ORGANIZATION IS LACK OF ANY SIGNIFICANT LOW LEVEL
CONVERGENCE DUE THE VERY WEAK WIND FIELDS OVER THE LAND. AGAIN...THE
EXCEPTION TO THIS IS OVER THE WEST WHERE CYCLONIC NNE FLOW IS QUITE
FAVORABLE FOR THE IWD AREA. LOCAL HI RES NWP AND ALONG WITH THE RAP
AND HRRR SUGGEST THAT AS THE LES WILL BECOME A LITTLE MORE ORGANIZED
BETWEEN 09Z AND 12Z AS THE SFC TROUGH OVER THE LAKE MOVES SOUTH AND
THE INVERSION DEEPENS TO NEARLY 8000FT AS WEAK Q-VECTOR CONVERGENCE
ASSOCIATED WITH THE UPPER TROUGH AXIS MOVES ACROSS THE AREA.
STILL...DESPITE THE EXPECTED INCREASED COVERAGE OF SNOW THIS
MORNING...THE FACT REMAINS THAT THERE IS NOT MUCH SNOW ONGOING RIGHT
NOW OTHER THAN FAR WESTERN GOGEBIC COUNTY...AND ANY ADDITIONAL
ACCUMULATION IN THE KEWEENAW AND IN THE NORTH CENTRAL AREAS WILL
ONLY AMOUNT TO AN INCH OR TWO. AS SUCH...HAVE OPTED TO DROP THE
ADVISORY FOR THOSE AREAS BUT KEEP IT FOR THE GOGEBIC AND ONTONAGON
THROUGH 15Z. SINCE IT IS NOT REALLY SNOWING IN THE CURRENT ADVISORY
AREA EXCEPT ACROSS THE FAR WEST...IT JUST DOES NOT SEEM PRUDENT TO
KEEP THE ADVISORY AT THIS TIME FOR MQT/BARAGA AND THE KEWEENAW FOR
ONLY AN ADDITIONAL INCH OR TWO OF ADDITIONAL SNOW. WILL STILL
FORECAST 2 TO LOCALLY 4 INCHES IN THE IRONWOOD/PORCUPINE MTNS AREA
FOR THIS MORNING AS THE SOUNDINGS LOOK QUITE FAVORABLE FOR A BRIEF
PERIOD OF MODERATE SNOWFALL WITH THE RISING INVERSION AND BETTER
DENDRITIC SNOW GROWTH WITH THE TOP OF THE INVERSION AROUND -18C.
AS THE LOW PULLS OUT...RIDGING SHOULD SLOWLY BUILD IN FROM THE WEST
THIS AFTERNOON INTO TONIGHT. THIS SHOULD ALLOW THE LES TO END FROM
WEST TO EAST DURING THE DAY AND INTO THIS EVENING. ANY LES THIS
EVENING WOULD BE FOCUSED IN AREAS EAST OF MUNISING DUE TO THE NW PBL
FLOW. HOWEVER...DO NOT EXPECT THIS LES TO LAST TOO LONG DUE TO THE
RIDGE BUILDING AND AND RAPIDLY DIMINISHING MOISTURE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT APR 13 2013
NAM SHOWS A 500 MB SHORTWAVE RIDGE OVER THE UPPER GREAT LAKES 12Z
SUN WITH A CLOSED LOW OVER THE NORTHERN ROCKIES. THIS CLOSED LOW
QUICKLY MOVES INTO THE NORTHERN PLAINS LATE SUN AND AFFECTS THE
UPPER GREAT LAKES SUN NIGHT BEFORE IT HEADS NORTHEAST AND SHEARS OUT
TO THE NORTH ON MON. NAM BRINGS IN SOME DEEPER MOISTURE SUN
AFTERNOON ALONG WITH 850-500 MB Q-VECTOR CONVERGENCE WHICH REMAINS
THROUGH SUN NIGHT BEFORE AREA GETS DRY SLOTTED ON MON. NAM SHOWS
SOME STRONG ISENTROPIC LIFT ON I280K-I295K SURFACES WITH DEEP
MOISTURE SUN EVENING WITH THE LIFT MOVING OUT BY 12Z MON. GFS AND
ECMWF SHOW ABOUT THE SAME THING AS WELL. LOOKS LIKE MON THAT MOST OF
THE CWA GETS DRY SLOTTED AND SHOULD HAVE BREEZY CONDITIONS ON
MONDAY. WITH DRY SLOT MOVING THROUGH...THINK THERE WILL BE SOME
SUNSHINE WITH SW WINDS ALLOWING SOME DOWNSLOPING TO OCCUR. FOR THIS
REASON AND A BIT MORE SUNSHINE...RAISED SOME HIGH TEMPERATURES A BIT
AND COULD SEE A FEW 50S FOR HIGHS ON MONDAY.
LOOKED AT A FEW THINGS AND AGREE WITH PREVIOUS SHIFTS THINKING OF
HAVING SOME SLEET...RAIN AND SNOW MENTIONED FOR PCPN TYPE FOR SUN
AFTERNOON AND EVENING BEFORE WARMING TAKES PLACE TO SWITCH ALL THE
PCPN OVER TO ALL RAIN LATE SUN NIGHT INTO MONDAY. COULD SEE
0.50-0.90 OF QPF FROM THIS EVENT WHICH WILL EQUATE OUT TO LESS THAN
TWO INCHES OF TOTAL SNOW AS THINGS ARE WARMING. WITH PCPN HOLDING
OFF UNTIL SUNDAY AFTERNOON...THINGS WILL BE WARM ENOUGH TO NOT HAVE
THE PCPN BE ALL SNOW OR SLEET. KEPT CATEGORICAL POPS IN FOR SUNDAY
NIGHT AND THEN HAVE DRY SLOT MOVING INTO THE WEST AND CENTRAL AREAS
FOR MON.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB CLOSED LOW IN JAMES
BAY 12Z TUE WITH TROUGHING EXTENDING FROM THAT BACK TO THE NORTHERN
PLAINS AND SOUTHERN ROCKIES. TROUGHING SLOWLY MOVES EAST 12Z WED AND
OUT INTO THE PLAINS 12Z THU AND INTO THE UPPER GREAT LAKES 12Z FRI.
ACTIVE AND COLD WEATHER PATTERN LOOKS TO CONTINUE WITH TEMPERATURES
REMAINING WELL BELOW NORMAL AND WETTER THAN NORMAL CONDITIONS WILL
ALSO CONTINUE THIS FORECAST PERIOD. TUE AND TUE NIGHT LOOK DRY FOR
NOW BEFORE NEXT STRONG SYSTEM ARRIVES FOR WED INTO FRI. THIS NEXT
SYSTEM LOOKS LIKE A MESS FOR PCPN TYPE WITH RAIN/SNOW MIX WITH
MOSTLY SNOW FALLING AS COLDER AIR COMES IN BEHIND IT ESPECIALLY FOR
FRI WITH THE ECMWF SHOWING 850 MB TEMPERATURES FALLING TO -12C TO
-14C. CONTINUED HIGH CHANCE POPS TO LIKELYS FOR THIS SYSTEM LOOK
GOOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 737 AM EDT SAT APR 13 2013
LIGHT SNOW WILL CONTINUE AT ALL OF THE TERMINALS THIS MORNING AS THE
UPPER LOW MOVES ACROSS THE AREA. IWD WILL BE THE MOST LIKELY TO SEE
IFR OR LIFR CONDITIONS THIS MORNING DUE THE LAKE ENHANCED
SNOW...ALTHOUGH ALL SITES HAVE THE POTENTIAL TO SEE IFR CONDITIONS
THIS MORNING BEFORE THE UPPER DISTURBANCE MOVES EAST. THE MOISTURE
AND REMAINING LIFT EXITS THE AREA BY THIS EVENING...WITH IWD SEEING
VFR CONDITIONS BY LATE THIS AFTERNOON. ONSHORE FLOW WILL KEEP CMX
AND SAW IN MVFR CONDITIONS UNTIL LATE TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EDT SAT APR 13 2013
BROAD LOW PRESSURE JUST EAST OF THE AREA WILL MOVE OUT TODAY. STILL
SOME GUSTY N-NW WINDS ACROSS THE WEST LAKE THIS MORNING...BUT THE
EXPECTATION IS THAT THESE WILL DIMINISH LATER THIS AFTERNOON INTO
THIS EVENING AS THE RIDGE OVER THE UPPER MISSISSIPPI VALLEY MOVES
ACROSS THE LAKE. AS LOW PRESSURE OVER THE PLAINS DEVELOPS TODAY AND
MOVES NORTH...EXPECT E-NE WINDS TO INCREASE SUNDAY AFTERNOON AND
NIGHT. COULD NOT RULE OUT NE GALES SUNDAY EVENING ACROSS THE
WEST...THEN SE GALES ACROSS THE EAST HALF LATE SUNDAY NIGHT INTO
EARLY MONDAY MORNING...BUT THEY WOULD LIKELY BE MARGINAL AND SHORT
LIVED. WINDS TURN SW BEHIND AN OCCLUDED FRONT ON MONDAY...THEN
GRADUALLY TURN W AND NW ON TUE AS HIGH PRESSURE BUILDS BACK IN. NE
WINDS RETURN WED AND PERHAPS ANOTHER STORM SYSTEM FOR LATE IN THE
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 11 AM EDT /10 AM CDT/ THIS MORNING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...07
AVIATION...MRD
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
440 AM EDT SAT APR 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT APR 13 2013
LAKE ENHANCEMENT HAVING A TOUGH TIME STARTING EARLY THIS
MORNING...EXCEPT FOR A BAND JUST WEST OF IWD. SEEMS LIKE THE MAIN
PROBLEM WITH ORGANIZATION IS LACK OF ANY SIGNIFICANT LOW LEVEL
CONVERGENCE DUE THE VERY WEAK WIND FIELDS OVER THE LAND. AGAIN...THE
EXCEPTION TO THIS IS OVER THE WEST WHERE CYCLONIC NNE FLOW IS QUITE
FAVORABLE FOR THE IWD AREA. LOCAL HI RES NWP AND ALONG WITH THE RAP
AND HRRR SUGGEST THAT AS THE LES WILL BECOME A LITTLE MORE ORGANIZED
BETWEEN 09Z AND 12Z AS THE SFC TROUGH OVER THE LAKE MOVES SOUTH AND
THE INVERSION DEEPENS TO NEARLY 8000FT AS WEAK Q-VECTOR CONVERGENCE
ASSOCIATED WITH THE UPPER TROUGH AXIS MOVES ACROSS THE AREA.
STILL...DESPITE THE EXPECTED INCREASED COVERAGE OF SNOW THIS
MORNING...THE FACT REMAINS THAT THERE IS NOT MUCH SNOW ONGOING RIGHT
NOW OTHER THAN FAR WESTERN GOGEBIC COUNTY...AND ANY ADDITIONAL
ACCUMULATION IN THE KEWEENAW AND IN THE NORTH CENTRAL AREAS WILL
ONLY AMOUNT TO AN INCH OR TWO. AS SUCH...HAVE OPTED TO DROP THE
ADVISORY FOR THOSE AREAS BUT KEEP IT FOR THE GOGEBIC AND ONTONAGON
THROUGH 15Z. SINCE IT IS NOT REALLY SNOWING IN THE CURRENT ADVISORY
AREA EXCEPT ACROSS THE FAR WEST...IT JUST DOES NOT SEEM PRUDENT TO
KEEP THE ADVISORY AT THIS TIME FOR MQT/BARAGA AND THE KEWEENAW FOR
ONLY AN ADDITIONAL INCH OR TWO OF ADDITIONAL SNOW. WILL STILL
FORECAST 2 TO LOCALLY 4 INCHES IN THE IRONWOOD/PORCUPINE MTNS AREA
FOR THIS MORNING AS THE SOUNDINGS LOOK QUITE FAVORABLE FOR A BRIEF
PERIOD OF MODERATE SNOWFALL WITH THE RISING INVERSION AND BETTER
DENDRITIC SNOW GROWTH WITH THE TOP OF THE INVERSION AROUND -18C.
AS THE LOW PULLS OUT...RIDGING SHOULD SLOWLY BUILD IN FROM THE WEST
THIS AFTERNOON INTO TONIGHT. THIS SHOULD ALLOW THE LES TO END FROM
WEST TO EAST DURING THE DAY AND INTO THIS EVENING. ANY LES THIS
EVENING WOULD BE FOCUSED IN AREAS EAST OF MUNISING DUE TO THE NW PBL
FLOW. HOWEVER...DO NOT EXPECT THIS LES TO LAST TOO LONG DUE TO THE
RIDGE BUILDING AND AND RAPIDLY DIMINISHING MOISTURE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT APR 13 2013
NAM SHOWS A 500 MB SHORTWAVE RIDGE OVER THE UPPER GREAT LAKES 12Z
SUN WITH A CLOSED LOW OVER THE NORTHERN ROCKIES. THIS CLOSED LOW
QUICKLY MOVES INTO THE NORTHERN PLAINS LATE SUN AND AFFECTS THE
UPPER GREAT LAKES SUN NIGHT BEFORE IT HEADS NORTHEAST AND SHEARS OUT
TO THE NORTH ON MON. NAM BRINGS IN SOME DEEPER MOISTURE SUN
AFTERNOON ALONG WITH 850-500 MB Q-VECTOR CONVERGENCE WHICH REMAINS
THROUGH SUN NIGHT BEFORE AREA GETS DRY SLOTTED ON MON. NAM SHOWS
SOME STRONG ISENTROPIC LIFT ON I280K-I295K SURFACES WITH DEEP
MOISTURE SUN EVENING WITH THE LIFT MOVING OUT BY 12Z MON. GFS AND
ECMWF SHOW ABOUT THE SAME THING AS WELL. LOOKS LIKE MON THAT MOST OF
THE CWA GETS DRY SLOTTED AND SHOULD HAVE BREEZY CONDITIONS ON
MONDAY. WITH DRY SLOT MOVING THROUGH...THINK THERE WILL BE SOME
SUNSHINE WITH SW WINDS ALLOWING SOME DOWNSLOPING TO OCCUR. FOR THIS
REASON AND A BIT MORE SUNSHINE...RAISED SOME HIGH TEMPERATURES A BIT
AND COULD SEE A FEW 50S FOR HIGHS ON MONDAY.
LOOKED AT A FEW THINGS AND AGREE WITH PREVIOUS SHIFTS THINKING OF
HAVING SOME SLEET...RAIN AND SNOW MENTIONED FOR PCPN TYPE FOR SUN
AFTERNOON AND EVENING BEFORE WARMING TAKES PLACE TO SWITCH ALL THE
PCPN OVER TO ALL RAIN LATE SUN NIGHT INTO MONDAY. COULD SEE
0.50-0.90 OF QPF FROM THIS EVENT WHICH WILL EQUATE OUT TO LESS THAN
TWO INCHES OF TOTAL SNOW AS THINGS ARE WARMING. WITH PCPN HOLDING
OFF UNTIL SUNDAY AFTERNOON...THINGS WILL BE WARM ENOUGH TO NOT HAVE
THE PCPN BE ALL SNOW OR SLEET. KEPT CATEGORICAL POPS IN FOR SUNDAY
NIGHT AND THEN HAVE DRY SLOT MOVING INTO THE WEST AND CENTRAL AREAS
FOR MON.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB CLOSED LOW IN JAMES
BAY 12Z TUE WITH TROUGHING EXTENDING FROM THAT BACK TO THE NORTHERN
PLAINS AND SOUTHERN ROCKIES. TROUGHING SLOWLY MOVES EAST 12Z WED AND
OUT INTO THE PLAINS 12Z THU AND INTO THE UPPER GREAT LAKES 12Z FRI.
ACTIVE AND COLD WEATHER PATTERN LOOKS TO CONTINUE WITH TEMPERATURES
REMAINING WELL BELOW NORMAL AND WETTER THAN NORMAL CONDITIONS WILL
ALSO CONTINUE THIS FORECAST PERIOD. TUE AND TUE NIGHT LOOK DRY FOR
NOW BEFORE NEXT STRONG SYSTEM ARRIVES FOR WED INTO FRI. THIS NEXT
SYSTEM LOOKS LIKE A MESS FOR PCPN TYPE WITH RAIN/SNOW MIX WITH
MOSTLY SNOW FALLING AS COLDER AIR COMES IN BEHIND IT ESPECIALLY FOR
FRI WITH THE ECMWF SHOWING 850 MB TEMPERATURES FALLING TO -12C TO
-14C. CONTINUED HIGH CHANCE POPS TO LIKELYS FOR THIS SYSTEM LOOK
GOOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 158 AM EDT SAT APR 13 2013
SOME CLEARING AND LIGHTENING OF WINDS OVER THE PAST FEW HOURS HAS
LED TO SOME GROUND FOG AND VLIFR CONDITIONS AT SAW (AND ALSO ESC). AS
THE SURFACE TROUGH MOVES THROUGH IN THE NEXT FEW HRS...EXPECT THIS TO
SUBSIDE.
WITH MID/UPPER LEVEL LOW DRIFTING ACROSS THE AREA...SCT/NMRS -SHSN
WILL CONTINUE INTO THE MORNING HRS. AT KIWD...FAVORABLE UPSLOPE
NORTHERLY WINDS OFF THE LAKE SHOULD RESULT IN PREVAILING IFR
CONDITIONS. WOULDN`T BE SURPRISED TO SEE BRIEF LIFR AT TIMES AS WELL
AS MVFR. AT KCMX...EXPECT CONDITIONS VARYING BTWN MVFR AND IFR. IFR
MAY BE MORE PERSISTENT LATER IN THE NIGHT INTO THE MORNING AS SFC
TROF DRIFTS ACROSS THE AREA. AT KSAW...MVFR CONDITIONS SHOULD
PREVAIL FOR MUCH OF THE NIGHT. AS SFC TROF DROPS ACROSS THE AREA
LATE...CONDITIONS SHOULD FALL TO IFR. AT ALL SITES...EXPECT
IMPROVEMENT TO MVFR LATE THIS MORNING...AND -SHSN SHOULD END BY LATE
AFTN. MVFR CIGS MAY CLEAR OUT OF KIWD THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EDT SAT APR 13 2013
BROAD LOW PRESSURE JUST EAST OF THE AREA WILL MOVE OUT TODAY. STILL
SOME GUSTY N-NW WINDS ACROSS THE WEST LAKE THIS MORNING...BUT THE
EXPECTATION IS THAT THESE WILL DIMINISH LATER THIS AFTERNOON INTO
THIS EVENING AS THE RIDGE OVER THE UPPER MISSISSIPPI VALLEY MOVES
ACROSS THE LAKE. AS LOW PRESSURE OVER THE PLAINS DEVELOPS TODAY AND
MOVES NORTH...EXPECT E-NE WINDS TO INCREASE SUNDAY AFTERNOON AND
NIGHT. COULD NOT RULE OUT NE GALES SUNDAY EVENING ACROSS THE
WEST...THEN SE GALES ACROSS THE EAST HALF LATE SUNDAY NIGHT INTO
EARLY MONDAY MORNING...BUT THEY WOULD LIKELY BE MARGINAL AND SHORT
LIVED. WINDS TURN SW BEHIND AN OCCLUDED FRONT ON MONDAY...THEN
GRADUALLY TURN W AND NW ON TUE AS HIGH PRESSURE BUILDS BACK IN. NE
WINDS RETURN WED AND PERHAPS ANOTHER STORM SYSTEM FOR LATE IN THE
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 11 AM EDT /10 AM CDT/ THIS MORNING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...07
AVIATION...MRD/ROLFSON
MARINE...MRD
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1202 AM CDT SAT APR 13 2013
.AVIATION...06Z TAF ISSUANCE...
WIDESPREAD LIGHT SNOW ACROSS ALL TERMINAL SITES FOR THE FIRST FEW
HOURS OF THIS TAF PERIOD..ALONG WITH LOW VFR/HIGH MVFR CEILINGS.
LIGHT SNOW SHOULD DIMINISH FROM WEST TO EAST AFTER 12Z AT MOST
TERMINALS. A SLOW LIFTING OF CLOUD BASES IS EXPECTED TODAY.
HOWEVER..A COMBINATION OF STEEP LOW LEVEL LAPSE RATES/RESIDUAL
BOUNDARY LAYER MOISTURE MAY PRODUCE BROKEN MVFR/VFR STRATOCUMULUS
DECK BEGINNING AROUND MIDDAY ALONG WITH PERIODIC SNOW SHOWERS IN
THE AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 1006 PM CDT FRI APR 12 2013/
UPDATE...
CENTER OF UPPER LOW IS LOCATED JUST SOUTH OF MARQUETTE MI LATE
THIS EVENING..AND IS CONTINUING TO PULL OFF TO THE EAST. HOWEVER..
BENT-BACK AXIS OF DEFORMATION AND LOWER HEIGHTS EXTENDS WEST FROM
THE LOW CENTER ACROSS NRN MINNESOTA..AND THE EASTWARD PROGRESS IS
BEING HAMPERED BY THE AMPLIFYING S/W TROF SLIDING EWD ACROSS NRN
IOWA AT THE MOMENT. THUS..WEAK FORCING FOR ASCENT IS LIKELY TO
PERSIST FOR EVEN LONGER THAN PREVIOUSLY THOUGH OVERNIGHT..WITH
LIGHT SNOW PERSISTING ACROSS MUCH OF EASTERN MN AND NW WISCONSIN.
WHILE PRECIP RATES WILL BE MUCH LESS THAN OBSERVED EARLIER
TODAY..HIGHER SNOW-LIQUID RATIOS AS COLUMN COOLS MAY STILL RESULT
IN ANOTHER FEW INCHES IN SOME OF THE FAVORED TERRAIN AREAS OF THE
BAYFIELD PENINSULA AND GOGEBIC RANGE WHERE NE WINDS WILL STILL
PROVIDE SOME ADDED MOISTURE FROM LK SUPERIOR.
WINDS HAVE DIMINISHED MARKEDLY FROM THIS AFTERNOON..AND WITH THE
CESSATION OF STRONGER WINDS AND HEAVIER SNOWFALL RATES OVER THE
ARROWHEAD..WE HAVE ALLOWED THE WINTER STORM WARNING TO EXPIRE AS
SCHEDULED AT 10 PM. HOWEVER..WE HELD ON TO WARNINGS/ADVISORIES FOR
THE SNOWBELT AREAS OF NW WISCONSIN.
OTHERWISE..WINDS SHOULD CONTINUE TO DIMINISH OVERNIGHT ALONG WITH
CLOUDY SKIES PERSISTING. UPDATES TO GRIDS AND ALL ASSOCIATED TEXT
PRODUCTS HAVE BEEN SENT.
PREV DISCUSSION... /ISSUED 345 PM CDT FRI APR 12 2013/
SHORT TERM...THROUGH SATURDAY.
WATER VAPOR SHOWS THE UPPER LOW MOVING NORTHEAST ACROSS NORTHERN
WISCONSIN THIS AFTERNOON...AND IT IS FORECAST TO MOVE OVER
EASTERN LAKE SUPERIOR TONIGHT...AND CONTINUE EAST ON SATURDAY.
LIGHT SNOW WILL LINGER TONIGHT...BUT BE MOST WIDESPREAD THROUGH
THE EVENING HOURS. INTENSITY OVERALL WILL BE LIGHT...BUT THERE
WILL BE PERIODS OF MODERATE SNOW WITH VSBYS DOWN TO AROUND A MILE
FOR A TIME. WE WENT WITH ADDITIONAL SNOWFALL AROUND AN INCH FOR
MOST AREAS...BUT WENT A BIT HIGHER OVER PORTIONS OF THE ARROWHEAD
AND ALONG THE SOUTH SHORE. THE SOUTH SHORE WILL GET INTO LAKE
ENHANCED SNOWFALL TONIGHT AS WINDS TURN NORTHERLY AND WITH 850MB
TEMPS FORECAST TO DROP TO AROUND -12C AND INVERSION LEVELS
INCREASE. THE SOUTH SHORE WILL HAVE TO BE WATCHED CLOSELY...IF
STABILITY IS LOWER THAN EXPECTED...SNOW RATES COULD GET HEAVY AT
TIMES ACROSS THE SNOWBELT OF ASHLAND/IRON COUNTIES. THE OTHER AREA
WE`LL HAVE TO MONITOR IS ACROSS NORTH CENTRAL DOUGLAS
COUNTY...SOUTHWEST TOWARD SOUTHEAST CARLTON COUNTIES. AS LOW LEVEL
WINDS BACK TO NORTHWEST TONIGHT...WE COULD SEE A GRAVITY WAVE
INDUCED BAND OF ENHANCED SNOWFALL DEVELOP. LOOKING AT A RAP CROSS
SECTION...A STRONG SIGNAL IS NOT SEEN ATTM.
LIGHT SNOW OR FLURRIES WILL LINGER INTO SATURDAY
MORNING...PARTICULARLY OVER THE EASTERN HALF OF THE CWA DUE TO THE
SLOW DEPARTURE OF THE UPPER LOW. HOWEVER...ADDITIONAL SNOWFALL
WILL BE QUITE LIGHT IF ANYTHING MEASURES AT ALL.
WE EXPECT HIGHS SATURDAY TO REACH THE 35 TO 40 FOR MOST AREAS.
LONG TERM...SATURDAY NIGHT - FRIDAY.
THE FOCUS IN THIS FORECAST IS THE WINTER STORM SYSTEM THAT IS
EXPECTED TO AFFECT THE NORTHLAND LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. THE MODELS CONTINUE TO INDICATE THAT A POTENT MID/UPPER LOW
PRESSURE SYSTEM AND ITS ASSOCIATED LOW PRESSURE SYSTEM AT THE
SURFACE WILL MOVE THROUGH THE NORTHERN PLAINS SUNDAY AND MOVE INTO
ONTARIO MONDAY.THE MODELS SEEM TO HAVE INCREASED THEIR SNOWFALL FOR
THIS SYSTEM FOR LATE SATURDAY NIGHT THROUGH MONDAY MORNING...AND
TRENDED A LITTLE COLDER. I STILL THINK THERE MAY BE A WINTRY MIX
ACROSS THE SOUTHERN FORECAST AREA DURING THE LATE MORNING AND AT
LEAST THE AFTERNOON DUE TO NOT ONLY WARMER SURFACE
TEMPERATURES...BUT INCREASING TEMPERATURES ALOFT. I DO NOT SEE ANY
SIGNIFICANT RISK OF FREEZING RAIN BASED ON THE SOUNDINGS...BUT WE
WILL NEED TO CONTINUALLY CHECK INTO THIS. THE WINTRY MIX ACROSS THE
SOUTH WILL LIKELY PREVENT MUCH ACCUMULATION OF SNOW...SO MOST OF THE
CONCERN IS FOR NE MINNESOTA FOR HEAVY SNOW WHERE TEMPERATURES WILL
BE COLDER. THIS STORM SYSTEM IS LOOKING MORE AND MORE LIKELY THAT IT
WILL BRING AT LEAST A WIDESPREAD 6 TO 8 INCHES ACROSS NE
MINNESOTA...ESPECIALLY NORTH OF HIGHWAY 2. SOME ARES OF FAR NORTHERN
MINNESOTA MAY GET UP TO 10 INCHES. I MAY BE ON THE HIGH SIDE WITH
THE STORM TOTAL SNOWFALL...SO I DO NOT IMAGINE AT THIS POINT THAT
THIS STORM WOULD YIELD MUCH MORE SNOW THAN THIS.
LIGHT SNOW COULD LINGER ACROSS NE MINNESOTA MONDAY INTO TUESDAY IN
THE WAKE OF THE STORM SYSTEM. BEYOND TUESDAY...PREVIOUS MODEL RUNS
HAD BEEN INDICATING THE POTENTIAL FOR ANOTHER WINTRY-WEATHER SYSTEM
MID TO LATE WEEK...BUT IT WAS GOING TO BE DEPENDENT THE TRACK OF THE
ASSOCIATED LOW PRESSURE SYSTEM. THE LATEST GFS AND ECMWF ARE BACKING
OFF ON HAVING THIS SYSTEM AFFECTING THE NORTHLAND IN THAT THEY HAVE
THE LOW TRACK VERY FAR SOUTH...BASICALLY FROM THE SOUTHERN PLAINS TO
MICHIGAN. HOWEVER...THE GEM HAS A TRACK THAT IS SIGNIFICANTLY
FARTHER NORTH AND STILL SUGGESTS THE POTENTIAL TO BRING SIGNIFICANT
SNOWFALL TO PARTS OF THE NORTHLAND MID TO LATE WEEK. UNTIL AND IF
THE GEM BACKS OFF ON THE SYSTEM...THAT WE STILL NEED TO CARRY PCPN
CHANCES FOR THE MID TO LATE WEEK.
OVERALL THE COLD WEATHER PATTERN IS EXPECTED TO CONTINUE OVER THE
UPCOMING WEEK.
&&
.POINT TEMPS/POPS...
DLH 30 23 37 21 / 100 90 30 10
INL 30 19 38 17 / 100 70 20 0
BRD 32 24 38 24 / 70 70 30 50
HYR 34 20 38 20 / 100 80 40 10
ASX 30 24 37 17 / 100 90 60 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MNZ025-033>036.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ010-011-018-019-026-037.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ012-020-021.
WI...WINTER WEATHER ADVISORY UNTIL 7 AM CDT SATURDAY FOR WIZ003-004.
WINTER STORM WARNING UNTIL 7 AM CDT SATURDAY FOR WIZ002.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-147-148.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT SATURDAY FOR LSZ140>146.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
356 AM EDT SAT APR 13 2013
.SYNOPSIS...
THINGS WILL BE MAINLY DRY TO START OFF TODAY. HOWEVER...UPPER
LEVEL LOW PRESSURE WILL SHIFT FROM THE NORTHERN GREAT LAKES TO THE
NORTHEAST OVER THE COURSE OF THE WEEKEND. PASSING DISTURBANCES IN
THE VICINITY OF THIS SYSTEM WILL CAUSE SCATTERED SHOWERS MAINLY IN
CENTRAL NEW YORK LATE TODAY THROUGH TONIGHT...BEFORE DIMINISHING
SUNDAY MORNING. RAIN SHOWERS WILL MIX WITH SNOW SHOWERS TONIGHT
AND EARLY SUNDAY. HIGH PRESSURE WILL BUILD IN LATE SUNDAY...WITH
WARMER WEATHER COMING FOR THE FOLLOWING SEVERAL DAYS.
&&
.NEAR TERM /THROUGH TONIGHT/...
215 AM UPDATE...
WITH SHORTWAVE EXITING THE AREA AND MUCH DRIER AIR MASS MOVING
IN...SPOTTY SHOWERS AND DRIZZLE ARE QUICKLY COMING TO AN END FOR
THE REMAINDER OF THE PREDAWN HOURS. INCOMING AIR MASS WILL HAVE
PRECIPITABLE WATER VALUES OF ONLY BETWEEN A THIRD AND A HALF INCH
DURING THE DAY TODAY. I CUT BACK AND/OR DELAYED POPS SIGNIFICANTLY
FOR MOST OF TODAY...WHICH WILL BE MAINLY DRY YET STILL WITH FAIR
AMOUNT OF CLOUDS. INVERTED-V IN LOWER LEVELS OF SOUNDINGS
INDICATE THAT IN ADDITION TO COVERAGE OF SHOWERS BEING VERY
LIMITED UNTIL LATE TODAY /FROM HAVING TO FIGHT THE DRY
AIR/...20-25 MPH GUSTS SHOULD HAVE NO PROBLEM MIXING DOWN THIS
AFTERNOON AND WOULD NOT BE SURPRISED IF A FEW GUSTS TOP 30 MPH
NEAR THE SCATTERED SHOWERS LATE TODAY.
MODELS AGREE THOUGH THAT A FAIRLY STRONG SHORTWAVE WILL SWING
THROUGH LATE TODAY WITH PERHAPS ANOTHER DECENT ONE TONIGHT. THIS
WILL STEEPEN LAPSE RATES WHICH ALONG WITH INCREASE IN MOISTURE
WITHIN LOWEST 10 KFT...SHOULD YIELD SCATTERED SHOWERS MAINLY IN
CENTRAL NEW YORK WITH NOMINAL AID OF GREAT LAKES MOISTURE. 850MB
TEMPERATURES DO NOT EVEN REACH MINUS-10 CELSIUS...SO AMOUNT OF
HELP FROM THE LAKES WILL BE LIMITED. WITH 925MB TEMPERATURES ALSO
DROPPING BELOW FREEZING...THE SCATTERED RAIN SHOWERS SHOULD MIX
WITH/CHANGE OVER TO SNOW SHOWERS. WHERE SNOW SHOWERS OCCUR THOUGH
AMOUNTS WILL BE VERY LIGHT...PERHAPS UP TO ABOUT AN INCH TOWARDS
TUG HILL IN NORTHERN ONEIDA COUNTY AND JUST TRACE TO FEW TENTHS
ELSEWHERE /MAINLY HIGH ELEVS/.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
355 AM UPDATE...
IT TAKES ALL DAY SUNDAY FOR 540 DECAMETER 1000-500MB THICKNESS
LINE TO PASS THROUGH THE AREA. COOL AND SOMEWHAT GUSTY WNW FLOW
WILL SUBSIDE BE LATE IN THE DAY AS SURFACE HIGH BUILDS IN. MODEL
SOUNDINGS SUGGEST ENOUGH MOISTURE TRAPPED UNDER DEVELOPING
SUBSIDENCE INVERSION...FOR AT LEAST SCATTERED CUMULUS DECK IF NOT
EVEN BROKEN. SO WHILE SOME SUNSHINE SHOULD OCCUR...IT WILL BE
TEMPERED BY FAIR AMOUNT OF CLOUDS. OVERALL...AFTER LOW CHANCE OF
MIXED SNOW/RAIN SHOWERS IN MAINLY THE NORTHEASTERN ZONES EARLY
SUNDAY MORNING...LOOKING AT A MAINLY DRY DAY WITH HIGHS FALLING
SHORT OF CLIMATOLOGY BY ROUGHLY 5 OR SO DEGREES. THAT BEING
SAID...THE PATTERN IS ABOUT TO TURN QUICKLY.
HIGH PRESSURE WILL SHIFT EAST SUNDAY NIGHT...AS ELEVATED WARM
FRONT ALOFT PASSES WITH A BAND OF CLOUDS /TOO MUCH DRY AIR IN LOW
LEVELS FOR PRECIPITATION/. UPPER RIDGE AXIS MOVES IN
MONDAY...WHILE AT THE SURFACE A BROAD WARM SOUTH-SOUTHEAST RETURN FLOW
WILL DEVELOP. USED MIX DOWN TOOL FROM 900MB ALONG WITH SOME BLEND
IN OF LATEST GUIDANCE NUMBERS TO DERIVE HIGHS NEAR 70 IN LAKE
PLAIN /HELPED BY DOWNSLOPING/ WITH MAINLY 60S ELSEWHERE. COOLEST
TEMPERATURES WILL ACTUALLY WITH THE UPSLOPE FLOW AGAINST THE
POCONOS AND CATSKILLS...INCLUDING SOME MARINE INFLUENCE...WITH SOME
PLACES NOT REACHING 60 DEGREES. REGARDLESS...QUITE A BIT WARMER
THAN TEMPERATURES THIS WEEKEND.
MODELS INDICATE FRONT APPROACHING FROM NORTHWEST AND SLOWING MONDAY
NIGHT...WILL HAVE A DIFFICULT TIME REACHING THE AREA. POPS FOR
THEN HAVE BEEN DELAYED AND LOWERED INTO SLIGHT TO LOW CHANCE
ACCORDINGLY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
3 PM FRIDAY UPDATE...
FOLLOWED WPC GUIDANCE WITH A PATTERN THAT LOOKS SIMILAR TO THIS
PAST WEEK. EARLY IN THE PERIOD RIDGING IN THE EAST AND A TROF OVER
THE DESERT SOUTHWEST WILL KEEP US WITH A WARM FLOW OF AIR WITH
850S AROUND 12C TUESDAY MORNING. EVENTUALLY BOTH THE EURO AND GFS
SHOW A COLD FRONT MOVING INTO OUR AREA THEN WAFFLING BACK AND
FORTH THROUGH THE WEEK. TIMING AND PLACEMENT DIFFERENCES EXIST BUT
THE OVERALL IDEA OF A WET AND UNSETTLED PATTERN LOOK SOLID. TEMPS
ARE GENERALLY IN THE 60S AND THIS IS A GOOD START FOR NOW. AS WE
GET CLOSER AND THE DETAILS GET IRONED OUT WE MAY AGAIN SEE LARGE
NORTH/SOUTH TEMPERATURE DIFFERENCES DUE TO THE FRONTAL POSITION.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
A PUSH OF DRY AIR ALONG A COLD FRONT HAS ARRIVED AT OUR NY
TERMINALS, BRINGING CEILINGS UP TO VFR. THE FRONT IS GETTING CLOSE
TO AVP, BUT IR SAT PROGS THE DRY AIR PUSH TO ARRIVE JUST PRIOR TO
7Z. FOR THIS REASON THE AVP TERMINAL IS FORECAST TO HAVE TEMPO IFR
CEILINGS FOR 1-2 HOURS.
SOME CONCERN THAT BGM/RME MAY FLIRT WITH IFR OVERNIGHT DUE TO LOW
TDD VALUES. HOWEVER THERE IS QUITE A BIT OF MIXING, AND LATEST
BUFKIT RAP DATA SHOWS NO IFR CLOUD POTENTIAL.
MVFR CLOUDS ARE PROGGED TO REFORM BETWEEN 10Z AND 14Z. CEILINGS
THIS AFTERNOON WILL BE BETWEEN 2500 AND 4000 FEET. MVFR
RESTRICTIONS IN SHOWER ACTIVITY ARE POSSIBLE TONIGHT.
.OUTLOOK...
SAT NGT TO SUN...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
SUN NGT TO MON...VFR.
MON NGT TO WED...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...MDP
LONG TERM...HEDEN
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
212 AM EDT SAT APR 13 2013
.SYNOPSIS...
THINGS WILL BE MAINLY DRY TO START OFF TODAY. HOWEVER...UPPER
LEVEL LOW PRESSURE WILL SHIFT FROM THE NORTHERN GREAT LAKES TO THE
NORTHEAST OVER THE COURSE OF THE WEEKEND. PASSING DISTURBANCES IN
THE VICINITY OF THIS SYSTEM WILL CAUSE SCATTERED RAIN AND SNOW SHOWERS
LATE TODAY THROUGH TONIGHT...BEFORE DIMINISHING SUNDAY MORNING.
AMOUNTS WILL BE LIGHT AND MAINLY IN CENTRAL NEW YORK. HIGH
PRESSURE WILL BUILD IN LATE SUNDAY...WITH WARMER WEATHER COMING FOR
THE FOLLOWING SEVERAL DAYS.
&&
.NEAR TERM /THROUGH TONIGHT/...
215 AM UPDATE...
WITH SHORTWAVE EXITING THE AREA AND MUCH DRIER AIR MASS MOVING
IN...SPOTTY SHOWERS AND DRIZZLE ARE QUICKLY COMING TO AN END FOR
THE REMAINDER OF THE PREDAWN HOURS. INCOMING AIR MASS WILL HAVE
PRECIPITABLE WATER VALUES OF ONLY BETWEEN A THIRD AND A HALF INCH
DURING THE DAY TODAY. I CUT BACK AND/OR DELAYED POPS SIGNIFICANTLY
FOR MOST OF TODAY...WHICH WILL BE MAINLY DRY YET STILL WITH FAIR
AMOUNT OF CLOUDS. INVERTED-V IN LOWER LEVELS OF SOUNDINGS
INDICATE THAT IN ADDITION TO COVERAGE OF SHOWERS BEING VERY
LIMITED UNTIL LATE TODAY /FROM HAVING TO FIGHT THE DRY
AIR/...20-25 MPH GUSTS SHOULD HAVE NO PROBLEM MIXING DOWN THIS
AFTERNOON AND WOULD NOT BE SURPRISED IF A FEW GUSTS TOP 30 MPH
NEAR THE SCATTERED SHOWERS LATE TODAY.
MODELS AGREE THOUGH THAT A FAIRLY STRONG SHORTWAVE WILL SWING
THROUGH LATE TODAY WITH PERHAPS ANOTHER DECENT ONE TONIGHT. THIS
WILL STEEPEN LAPSE RATES WHICH ALONG WITH INCREASE IN MOISTURE
WITHIN LOWEST 10 KFT...SHOULD YIELD SCATTERED SHOWERS MAINLY IN
CENTRAL NEW YORK FROM NOMINAL AID OF GREAT LAKES MOISTURE. 850MB
TEMPERATURES DO NOT EVEN REACH MINUS-10 CELSIUS...SO AMOUNT OF
HELP FROM THE LAKES WILL BE LIMITED. WITH 925MB TEMPERATURES ALSO
DROPPING BELOW FREEZING...THE SCATTERED RAIN SHOWERS SHOULD MIX
WITH/CHANGE OVER TO SNOW SHOWERS. AMOUNTS THOUGH WILL BE VERY
LIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
315 PM UPDATE...
SUNDAY WL LKLY RESULT IN HIGHS BLO CLIMO ACRS NY STATE WITH COLD
AIR FILTERING IN FM CANADA ON NRLY FLOW WITH SFC HIPRES BUILDING
IN FM THE WEST. H8 TEMPS EXPECTED TO DROP TO BTWN -6C AND -9C.
EXPECT WINDS TO BE OUT OF THE WEST BUT LITTLE CHC FOR LK EFFECT
OVR FAR NRN ZONES WITH DELTA T`S EARLY IN THE DAY ARND 12C AND HV
KEPT LO-SLGT CHC POPS THRU 18Z SUNDAY.
HIPRES WL END THE SHORT TERM WITH NO WX EXPECTED FM ABOUT SUN AFTN
THRU THE DAY MONDAY. TEMPS WL MODERATE THRU EARLY NEXT WEEK WITH
MAXES PROGGED TO BE IN THE 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 PM UPDATE...
FOLLOWED WPC GUIDANCE WITH A PATTERN THAT LOOKS SIMILAR TO THIS
PAST WEEK. EARLY IN THE PERIOD RIDGING IN THE EAST AND A TROF OVER
THE DESERT SOUTHWEST WILL KEEP US WITH A WARM FLOW OF AIR WITH
850S AROUND 12C TUESDAY MORNING. EVENTUALLY BOTH THE EURO AND GFS
SHOW A COLD FRONT MOVING INTO OUR AREA THEN WAFFLING BACK AND
FORTH THROUGH THE WEEK. TIMING AND PLACEMENT DIFFERENCES EXIST BUT
THE OVERALL IDEA OF A WET AND UNSETTLED PATTERN LOOK SOLID. TEMPS
ARE GENERALLY IN THE 60S AND THIS IS A GOOD START FOR NOW. AS WE
GET CLOSER AND THE DETAILS GET IRONED OUT WE MAY AGAIN SEE LARGE
NORTH/SOUTH TEMPERATURE DIFFERENCES DUE TO THE FRONTAL POSITION.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A PUSH OF DRY AIR ALONG A COLD FRONT HAS ARRIVED AT OUR NY
TERMINALS, BRINGING CEILINGS UP TO VFR. THE FRONT IS GETTING CLOSE
TO AVP, BUT IR SAT PROGS THE DRY AIR PUSH TO ARRIVE JUST PRIOR TO
7Z. FOR THIS REASON THE AVP TERMINAL IS FORECAST TO HAVE TEMPO IFR
CEILINGS FOR 1-2 HOURS.
SOME CONCERN THAT BGM/RME MAY FLIRT WITH IFR OVERNIGHT DUE TO LOW
TDD VALUES. HOWEVER THERE IS QUITE A BIT OF MIXING, AND LATEST
BUFKIT RAP DATA SHOWS NO IFR CLOUD POTENTIAL.
MVFR CLOUDS ARE PROGGED TO REFORM BETWEEN 10Z AND 14Z. CEILINGS
THIS AFTERNOON WILL BE BETWEEN 2500 AND 4000 FEET. MVFR
RESTRICTIONS IN SHOWER ACTIVITY ARE POSSIBLE TONIGHT.
.OUTLOOK...
SAT NGT TO SUN...MAINLY VFR BUT PSBL MVFR IN MIXED SHWRS.
SUN NGT TO MON...VFR.
MON NGT TO WED...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...PVN
LONG TERM...HEDEN
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
403 AM CDT SAT APR 13 2013
.SHORT TERM /TODAY THROUGH SUNDAY/...500MB LOW/TROUGH ACROSS
NORTHWEST MEXICO THIS MORNING WILL MOVE EASTWARD ACROSS NORTHERN
MEXICO THIS AFTERNOON AND EASTWARD ACROSS EAST TEXAS SUNDAY. AN
UPPER LEVEL JET ACROSS NORTHERN MEXICO WILL MOVE EASTWARD ACROSS
THE CWA THIS AFTERNOON INTO TONIGHT PROVIDING ENOUGH FORCING WITH
THE SHORTWAVE TROUGH TO PROVIDE A SLIGHT CHANCE OF CONVECTION
ACROSS THE AREA TONIGHT INTO EARLY SUNDAY BEFORE DRIER AIR AND
SUBSIDENCE INCREASES FROM THE WEST ON SUNDAY. RUC13 CONTINUES TO
INDICATE 850MB RELATIVE HUMIDITY INCREASING ACROSS THE RIO GRANDE
VALLEY TODAY AND THIS LIMIT DIURNAL HEATING TO AN EXTENT THIS
AFTERNOON. CLOUD COVER WILL INCREASE THIS AFTERNOON AND CONTINUE
TO INCREASE TONIGHT BEFORE CLEARING FROM WEST TO EAST SUNDAY.
TEMPERATURES WILL BE WARMER SUNDAY THAN TODAY WITH WINDS VEERING
TO THE SOUTH AND THE LACK OF CLOUDS...ESPECIALLY OUT WEST.
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...WEAK RIDGING WILL BE
BUILDING AT THE BEGINNING OF NEXT WEEK AS THE LATEST IMPULSE RACES
OFF TO THE EAST. DRIER LOWER LEVELS AND DRY SW FLOW ALOFT WILL
PRECLUDE PRECIPITATION THROUGH WEDNESDAY...WITH TEMPERATURES
GRADUALLY CLIMBING INTO THE MID TO UPPER 90S. THE NEXT LARGE-SCALE
WEATHER SYSTEM DIVES ACROSS THE ROCKIES AND INTO TEXAS WEDNESDAY
EVENING. THIS WILL DRIVE THE NEXT COLD FRONT THROUGH TEXAS
WEDNESDAY NIGHT. MODELS ARE STILL A BIT DIFFERENT ON LOCATING THE
CENTRAL SFC LOW ALONG THE ADVANCING FRONT...BUT ARE SIMILAR IN THE
FINAL TIMING OF THE FRONT. IT IS EXPECTED TO ARRIVE THURSDAY
MORNING...WITH SHOWER AND THUNDERSTORM ACTIVITY. THE FRONT WILL
MOVE THROUGH QUICKLY...WITH ONLY SOME RESIDUAL RAIN CHANCES
POSSIBLE FOR THE IMMEDIATE COASTAL AREAS THURSDAY AFTERNOON. DRIER
AIR WILL MOVE IN QUICKLY IN THE WAKE OF THE FRONT...WITH HIGH
THURSDAY ONLY EXPECTED TO REACH THE UPPER 70S TO LOWER 80S.
&&
.MARINE...
TODAY THROUGH SUNDAY...SEAS WERE NEAR 4 FEET WITH SOUTHEAST WINDS
NEAR 14 KNOTS AT BUOY020 EARLY THIS MORNING. MODERATE EAST TO
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY
BEFORE THE PRESSURE GRADIENT WEAKENS ACROSS THE WESTERN GULF OF
MEXICO TONIGHT. LIGHT EAST TO SOUTHEAST WINDS WILL PREVAIL TONIGHT
INTO SUNDAY AS HIGH PRESSURE ACROSS THE SOUTHEAST UNITED STATES
MOVES EASTWARD AND A FRONTAL SYSTEM MOVES INTO THE NORTH CENTRAL
U.S.
MONDAY THROUGH THURSDAY...SOUTHEAST WINDS WILL INCREASE STARTING
MONDAY AS THE SFC HIGH MOVES INTO THE SOUTHEASTERN US AND LOW
PRESSURE DRIFTS INTO THE TEXAS PANHANDLE. GRADIENT REMAINS
TIGHT...SO WINDS OF AT LEAST 15 KNOTS WILL CONTINUE THROUGH
WEDNESDAY. BREEZY CONDITIONS WILL LEAD TO GRADUALLY INCREASING
SEAS...REACHING 5 TO 6 FEET WEDNESDAY. THE NEXT FRONT IS EXPECTED
THURSDAY MORNING...SWITCHING WINDS TO THE NORTH AND INCREASING TO
20 TO 25 KNOTS...WITH SEAS REACHING 8 TO 10 FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 80 68 83 70 / 10 20 10 10
BROWNSVILLE 81 68 85 70 / 10 20 10 10
HARLINGEN 84 67 88 69 / 10 20 10 10
MCALLEN 85 69 91 70 / 10 20 10 10
RIO GRANDE CITY 86 67 94 70 / 10 20 10 10
SOUTH PADRE ISLAND 76 68 77 70 / 10 20 10 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
61/64
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1257 PM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 838 AM MDT SAT APR 13 2013
DENSE FOG CONTINUES ALONG AND JUST TO THE NORTH OF THE REPUBLICAN
RIVER VALLEY WITH MCK REPORTING LESS THAN A QUARTER MILE
VISIBILITIES. LOOKS LIKE THIS IS CONFINED TO NORTHERN RED WILLOW
AND NORTHEAST HITCHCOCK COUNTY...AND HAVE EXPANDED THE ADVISORY
FOR ANOTHER HOURS. GIVEN THE SMALL SCALE NATURE OF IT...SHOULD
BEGIN TO CLEAR OUT QUICKLY.
UPDATE ISSUED AT 608 AM MDT SAT APR 13 2013
UPDATED FOR A DENSE FOG ADVISORY FOR HITCHCOCK AND RED WILLOW.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 440 AM MDT SAT APR 13 2013
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION INTO THE
BEGINNING OF NEXT WEEK...FIRE WEATHER CONCERNS TODAY...AND WINDS
TODAY/TONIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN
FROM THE PACIFIC ACROSS NORTH AMERICA INTO THE ATLANTIC. CONTINUES TO
SHOW AN AMPLIFIED AND BLOCKY PATTERN FROM THE PACIFIC INTO EASTERN
NORTH AMERICA. VERY STRONG AND COLD SYSTEM IS DIGGING INTO SOUTHWEST
CANADA AND THE PACIFIC NORTHWEST. CURRENTLY WEST NORTHWEST TO
NORTHWEST RESIDES OVER THE REGION.
AT JET LEVEL...THE MODELS TENDED TO NOT HAVE THE JET AXIS THAT IS
PUNCHING INTO THE PACIFIC NORTHWEST TOO FAR NORTH AND EAST. THE NAM
AND GFS WERE DOING BEST ON THIS SEGMENT. THE MODELS TENDED TO HAVE
THE HEIGHT FIELD TOO FAR SOUTH AND EAST. OVERALL THE GFS...UKMET
AND CANADIAN WERE DOING THE BEST. THE RUC AND ECMWF WERE DOING
SLIGHTLY BETTER THAN THE NAM ON THE SURFACE WIND AND PRESSURE
FIELD. GFS AND CANADIAN WERE DOING A LITTLE BETTER THAN THE NAM ON
THE LOW LEVEL THERMAL FIELD.
PER THE INITIAL ANALYSIS AND THE PATTERN WE ARE IN...CHOSE THE
MID/UPPER LEVEL SOLUTIONS THAT WERE FURTHER SOUTH AND FASTER
INITIALLY FOLLOWED BY BEING FURTHER SOUTH AND WEST WITH THE INCOMING
LATER.
TODAY/TONIGHT...FIRST WHAT TO DO WITH THE FOG. MODELS...EVEN
MESOSCALE...HAVING DIFFICULTY GRABBING ONTO THE FOG. WHAT IS
COMPLICATING THINGS IS A CLOUD DECK ABOVE THIS THAT HAS BEEN CAUSING
VARIABILITY IN THE FOG FIELD. BASED ON LATEST TRENDS...CHOSE TO GO
AREAS OF FOG IN THE NORTHERN AND WESTERN SECTIONS AND PATCHY
ELSEWHERE. AS THE SUN COMES UP AND THE WINDS BEGIN TO INCREASE...
THE FOG SHOULD BURN OFF.
CROSS MOUNTAIN FLOW WILL CAUSE LEE TROUGH TO DEVELOP RAPIDLY. 3 HOUR
PRESSURE FALLS AND GRADIENT WOULD INDICATE AT LEAST BREEZY POSSIBLY
A LITTLE HIGHER CONDITIONS. THIS WILL HAVE AN AFFECT ON THE FIRE
WEATHER CONDITIONS. REFER TO THAT BELOW. GUIDANCE HAS BEEN COOL THE
LAST FEW DAYS AND NOT BY A LITTLE BIT...EVEN WITH CLOUDS AROUND. SO
TOOK THE WARMEST BIAS AND ADJUSTED IT WITH SOME BIAS/CHANGE IN
FORECAST 850 MB TEMPERATURE TO ARRIVE AT THE HIGHS.
MAIN JET AXIS STAYS NORTH AND WEST OF THE AREA. ALSO MAIN MID LEVEL
AND PV ANOMALY ARE STILL NORTH OF THE AREA. ALSO SOUNDINGS HAVE TOO
MUCH OF A DRY LAYER. THERE IS SOME SURFACE BASED INSTABILITY IN THE
AFTERNOON BUT THAT IS CAPPED. THERE IS NO ELEVATED INSTABILITY PLUS
IT IS CAPPED AS WELL EVEN IF THERE WAS ANY. SO WILL KEEP THIS
PERIOD DRY. HOWEVER...SOME KIND OF PRECIPITATION COULD GET CLOSE TO
THE FAR NORTHERN SECTION. CLOUD COVER AND WESTERLY WINDS/WARM AIR
ADVECTION IN ADVANCE OF THE COLD FRONT THAT ARRIVES LATER TONIGHT
WILL KEEP THE MINS RATHER MILD. THEY MAY NOT BE WARM ENOUGH. RATHER
SUNDAY/SUNDAY NIGHT...RATHER STRONG 3 HOUR PRESSURE RISE WILL CAUSE
BREEZY TO WINDY CONDITIONS BEHIND THE FRONT IN THE MORNING. LEFT
FRONT QUADRANT OF STRONG JET BEGINS TO AFFECT THE AREA AT THE
BEGINNING OF THE DAY AND THEN STARTS GRADUALLY LIFTING TO THE NORTH
AT THE END OF THE DAY. MID LEVEL COLD AIR ADVECTION/BAROCLINIC ZONE
ALONG WITH RATHER STRONG PV ANOMALY PUSHES ACROSS THE AREA AT THE
SAME WITH THE BEST LIFT AND MOISTURE OVER THE NORTHERN PORTION OF THE
AREA. SO EXPANDED POPS THROUGH THE DAY WITH THE HIGHEST IN THE
NORTHERN PORTION. COMBINATION OF CLOUD COVER/PRECIPITATION AND COLD
AIR ADVECTION WILL TEMPERATURES FROM RISING TOO MUCH AND WENT A
LITTLE BELOW GUIDANCE.
RIGHT REAR QUADRANT IS OVER THE AREA DURING THE NIGHT AND GETS
BETTER AS THE NIGHT WHERES ON AND AS THE MID LEVEL BAROCLINIC ZONE
REMAINS OVER THE AREA. PLUS ANOTHER SHORTWAVE TROUGH APPROACHES BY
LATER IN THE NIGHT. CURRENT FORECAST CAPTURES THIS SCENARIO NICELY
AND DID NOT CHANGE IT WITH GREATEST CHANCE OF PRECIPITATION
WILL BE IN THE NORTH WITH A CHANGEOVER OR MIXTURE OF PHASE EXPECTED
IN THE WEST.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF JET/JET AXIS REMAINS
OVER OR NEAR THE NORTHWEST HALF OF THE AREA THROUGH THE PERIOD.
LOW LEVEL UPSLOPE INCREASES THROUGH THE DAY AS STRONG MID LEVEL
SOUTHWEST FLOW ALOFT CAUSES LEE TROUGH TO STRENGTHEN. ALSO A COUPLE
OF SHORTWAVE TROUGHS MOVE THROUGH IN THIS FLOW. ALMOST EVERY
PARAMETER OF THE FORECAST FOR THIS PERIOD WILL BE PROBLEMATIC.
BECAUSE OF THE PROXIMITY OF THE JET AND MID LEVEL LIFT...KEPT THE
HIGHEST POPS IN THAT SECTION. HOWEVER...THERE IS A SHARP CUTOFF
BETWEEN A LOT OF CLOUDS/NO CLOUDS AND PRECIPITATION/NO
PRECIPITATION. SO ANY SUBTLE SHIFT NORTH OR SOUTH WILL GREATLY
AFFECT EVERY PARAMETER OF THE FORECAST. SO MADE ONLY MINOR
MODIFICATIONS. IF MODELS CONTINUE THE CURRENT TRENDS...THE
NORTHWEST HALF...ESPECIALLY THE CORNER...WILL NEED TO HAVE POPS
RAMPED UP CONSIDERABLY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT APR 13 2013
AN UPPER LEVEL TROUGH WILL DEEPEN OVER THE WESTERN CONUS TO START
OUT THE PERIOD. THE TROUGH WILL LINGER THERE THROUGH WEDNESDAY
BEFORE MOVING TOWARD THE AREA. WHILE THE UPPER LEVEL TROUGH REMAINS
SEMI STATIONARY LIFT FROM THE TROUGH WILL MOVE OVER THE AREA AND THE
ENVIRONMENT WILL BECOME SATURATED. THE BEST LIFT WILL MOVE OVER THE
AREA TUESDAY NIGHT AND WEDNESDAY. HAVE THE BEST PRECIP. CHANCES FOR
TUESDAY NIGHT DUE TO THE STRONGER FRONTOGENESIS OVER THE AREA
COMPARED TO WEDNESDAY.
ON WEDNESDAY THE MID LEVEL TROUGH MOVES OVER THE AREA AND WINDS
INCREASE AS AN ARCTIC COLD FRONT MOVES THROUGH. THE GUSTY WINDS MAY
CAUSE PATCHY BLOWING SNOW. DURING THE EVENING THE LIFT BEGINS TO
DECLINE AS THE MID LEVEL TROUGH MOVES TO THE EAST AND THE UPPER
LEVEL TROUGH AXIS BEGINS TO MOVE THROUGH THE AREA. PRECIP. COMES TO
AN END THURSDAY MORNING AS THE LAST OF THE LINGERING LIFT FROM THE
MID LEVEL TROUGH MOVES OUT OF THE AREA.
THERE IS STILL SOME UNCERTAINTY AS TO WHAT THE PHASE OF THE PRECIP.
WILL BE FOR PORTIONS OF THE FORECAST SINCE MODELS DISAGREE WITH THE
AMOUNT OF SATURATION ABOVE THE -10C LEVEL...SO HAVE CHOSEN TO GO WITH
A RAIN/SNOW MIX AT THIS TIME WHICH WILL NEGATIVELY AFFECT FORECASTED
SNOWFALL AMOUNTS. IF TEMPERATURES COOL FURTHER SNOW-TO-LIQUID
RATIOS WILL INCREASE WHICH WILL ALSO CAUSE THE SNOWFALL AMOUNTS TO
INCREASE. CURRENTLY HAVE 1-4 INCHES FORECAST ACROSS THE AREA...WITH
THE HIGHER AMOUNTS OVER THE WESTERN PART OF THE AREA WHERE THE
BETTER LIFT WILL BE.
TEMPERATURES FOR THE PERIOD WILL BE BELOW NORMAL...BUT LOW
TEMPERATURES WILL NEAR NORMAL VALUES BY THE END OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1255 PM MDT SAT APR 13 2013
...UPDATED...
SMALL PLUME OF BLOWING DIRT FROM CONSTRUCTION NEAR GLD RUNWAY IS
RESULTING IN A LOCALIZED AREA OF REDUCED VISIBILITIES IN BLOWING
DIRT. THIS SHOULD NOT BECOME WIDESPREAD NOR LONG LASTING.
OTHERWISE...VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS AS
A STRONG COLD FRONT MOVES ACROSS THE REGION. WINDS WILL SHIFT FROM
THE SOUTHWEST TO THE NORTHWEST AND INCREASE TO 25 TO 35 MPH
OVERNIGHT AND INTO THE MORNING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1142 AM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 838 AM MDT SAT APR 13 2013
DENSE FOG CONTINUES ALONG AND JUST TO THE NORTH OF THE REPUBLICAN
RIVER VALLEY WITH MCK REPORTING LESS THAN A QUARTER MILE
VISIBILITIES. LOOKS LIKE THIS IS CONFINED TO NORTHERN RED WILLOW
AND NORTHEAST HITCHCOCK COUNTY...AND HAVE EXPANDED THE ADVISORY
FOR ANOTHER HOURS. GIVEN THE SMALL SCALE NATURE OF IT...SHOULD
BEGIN TO CLEAR OUT QUICKLY.
UPDATE ISSUED AT 608 AM MDT SAT APR 13 2013
UPDATED FOR A DENSE FOG ADVISORY FOR HITCHCOCK AND RED WILLOW.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 440 AM MDT SAT APR 13 2013
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION INTO THE
BEGINNING OF NEXT WEEK...FIRE WEATHER CONCERNS TODAY...AND WINDS
TODAY/TONIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN
FROM THE PACIFIC ACROSS NORTH AMERICA INTO THE ATLANTIC. CONTINUES TO
SHOW AN AMPLIFIED AND BLOCKY PATTERN FROM THE PACIFIC INTO EASTERN
NORTH AMERICA. VERY STRONG AND COLD SYSTEM IS DIGGING INTO SOUTHWEST
CANADA AND THE PACIFIC NORTHWEST. CURRENTLY WEST NORTHWEST TO
NORTHWEST RESIDES OVER THE REGION.
AT JET LEVEL...THE MODELS TENDED TO NOT HAVE THE JET AXIS THAT IS
PUNCHING INTO THE PACIFIC NORTHWEST TOO FAR NORTH AND EAST. THE NAM
AND GFS WERE DOING BEST ON THIS SEGMENT. THE MODELS TENDED TO HAVE
THE HEIGHT FIELD TOO FAR SOUTH AND EAST. OVERALL THE GFS...UKMET
AND CANADIAN WERE DOING THE BEST. THE RUC AND ECMWF WERE DOING
SLIGHTLY BETTER THAN THE NAM ON THE SURFACE WIND AND PRESSURE
FIELD. GFS AND CANADIAN WERE DOING A LITTLE BETTER THAN THE NAM ON
THE LOW LEVEL THERMAL FIELD.
PER THE INITIAL ANALYSIS AND THE PATTERN WE ARE IN...CHOSE THE
MID/UPPER LEVEL SOLUTIONS THAT WERE FURTHER SOUTH AND FASTER
INITIALLY FOLLOWED BY BEING FURTHER SOUTH AND WEST WITH THE INCOMING
LATER.
TODAY/TONIGHT...FIRST WHAT TO DO WITH THE FOG. MODELS...EVEN
MESOSCALE...HAVING DIFFICULTY GRABBING ONTO THE FOG. WHAT IS
COMPLICATING THINGS IS A CLOUD DECK ABOVE THIS THAT HAS BEEN CAUSING
VARIABILITY IN THE FOG FIELD. BASED ON LATEST TRENDS...CHOSE TO GO
AREAS OF FOG IN THE NORTHERN AND WESTERN SECTIONS AND PATCHY
ELSEWHERE. AS THE SUN COMES UP AND THE WINDS BEGIN TO INCREASE...
THE FOG SHOULD BURN OFF.
CROSS MOUNTAIN FLOW WILL CAUSE LEE TROUGH TO DEVELOP RAPIDLY. 3 HOUR
PRESSURE FALLS AND GRADIENT WOULD INDICATE AT LEAST BREEZY POSSIBLY
A LITTLE HIGHER CONDITIONS. THIS WILL HAVE AN AFFECT ON THE FIRE
WEATHER CONDITIONS. REFER TO THAT BELOW. GUIDANCE HAS BEEN COOL THE
LAST FEW DAYS AND NOT BY A LITTLE BIT...EVEN WITH CLOUDS AROUND. SO
TOOK THE WARMEST BIAS AND ADJUSTED IT WITH SOME BIAS/CHANGE IN
FORECAST 850 MB TEMPERATURE TO ARRIVE AT THE HIGHS.
MAIN JET AXIS STAYS NORTH AND WEST OF THE AREA. ALSO MAIN MID LEVEL
AND PV ANOMALY ARE STILL NORTH OF THE AREA. ALSO SOUNDINGS HAVE TOO
MUCH OF A DRY LAYER. THERE IS SOME SURFACE BASED INSTABILITY IN THE
AFTERNOON BUT THAT IS CAPPED. THERE IS NO ELEVATED INSTABILITY PLUS
IT IS CAPPED AS WELL EVEN IF THERE WAS ANY. SO WILL KEEP THIS
PERIOD DRY. HOWEVER...SOME KIND OF PRECIPITATION COULD GET CLOSE TO
THE FAR NORTHERN SECTION. CLOUD COVER AND WESTERLY WINDS/WARM AIR
ADVECTION IN ADVANCE OF THE COLD FRONT THAT ARRIVES LATER TONIGHT
WILL KEEP THE MINS RATHER MILD. THEY MAY NOT BE WARM ENOUGH. RATHER
SUNDAY/SUNDAY NIGHT...RATHER STRONG 3 HOUR PRESSURE RISE WILL CAUSE
BREEZY TO WINDY CONDITIONS BEHIND THE FRONT IN THE MORNING. LEFT
FRONT QUADRANT OF STRONG JET BEGINS TO AFFECT THE AREA AT THE
BEGINNING OF THE DAY AND THEN STARTS GRADUALLY LIFTING TO THE NORTH
AT THE END OF THE DAY. MID LEVEL COLD AIR ADVECTION/BAROCLINIC ZONE
ALONG WITH RATHER STRONG PV ANOMALY PUSHES ACROSS THE AREA AT THE
SAME WITH THE BEST LIFT AND MOISTURE OVER THE NORTHERN PORTION OF THE
AREA. SO EXPANDED POPS THROUGH THE DAY WITH THE HIGHEST IN THE
NORTHERN PORTION. COMBINATION OF CLOUD COVER/PRECIPITATION AND COLD
AIR ADVECTION WILL TEMPERATURES FROM RISING TOO MUCH AND WENT A
LITTLE BELOW GUIDANCE.
RIGHT REAR QUADRANT IS OVER THE AREA DURING THE NIGHT AND GETS
BETTER AS THE NIGHT WHERES ON AND AS THE MID LEVEL BAROCLINIC ZONE
REMAINS OVER THE AREA. PLUS ANOTHER SHORTWAVE TROUGH APPROACHES BY
LATER IN THE NIGHT. CURRENT FORECAST CAPTURES THIS SCENARIO NICELY
AND DID NOT CHANGE IT WITH GREATEST CHANCE OF PRECIPITATION
WILL BE IN THE NORTH WITH A CHANGEOVER OR MIXTURE OF PHASE EXPECTED
IN THE WEST.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF JET/JET AXIS REMAINS
OVER OR NEAR THE NORTHWEST HALF OF THE AREA THROUGH THE PERIOD.
LOW LEVEL UPSLOPE INCREASES THROUGH THE DAY AS STRONG MID LEVEL
SOUTHWEST FLOW ALOFT CAUSES LEE TROUGH TO STRENGTHEN. ALSO A COUPLE
OF SHORTWAVE TROUGHS MOVE THROUGH IN THIS FLOW. ALMOST EVERY
PARAMETER OF THE FORECAST FOR THIS PERIOD WILL BE PROBLEMATIC.
BECAUSE OF THE PROXIMITY OF THE JET AND MID LEVEL LIFT...KEPT THE
HIGHEST POPS IN THAT SECTION. HOWEVER...THERE IS A SHARP CUTOFF
BETWEEN A LOT OF CLOUDS/NO CLOUDS AND PRECIPITATION/NO
PRECIPITATION. SO ANY SUBTLE SHIFT NORTH OR SOUTH WILL GREATLY
AFFECT EVERY PARAMETER OF THE FORECAST. SO MADE ONLY MINOR
MODIFICATIONS. IF MODELS CONTINUE THE CURRENT TRENDS...THE
NORTHWEST HALF...ESPECIALLY THE CORNER...WILL NEED TO HAVE POPS
RAMPED UP CONSIDERABLY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT APR 13 2013
AN UPPER LEVEL TROUGH WILL DEEPEN OVER THE WESTERN CONUS TO START
OUT THE PERIOD. THE TROUGH WILL LINGER THERE THROUGH WEDNESDAY
BEFORE MOVING TOWARD THE AREA. WHILE THE UPPER LEVEL TROUGH REMAINS
SEMI STATIONARY LIFT FROM THE TROUGH WILL MOVE OVER THE AREA AND THE
ENVIRONMENT WILL BECOME SATURATED. THE BEST LIFT WILL MOVE OVER THE
AREA TUESDAY NIGHT AND WEDNESDAY. HAVE THE BEST PRECIP. CHANCES FOR
TUESDAY NIGHT DUE TO THE STRONGER FRONTOGENESIS OVER THE AREA
COMPARED TO WEDNESDAY.
ON WEDNESDAY THE MID LEVEL TROUGH MOVES OVER THE AREA AND WINDS
INCREASE AS AN ARCTIC COLD FRONT MOVES THROUGH. THE GUSTY WINDS MAY
CAUSE PATCHY BLOWING SNOW. DURING THE EVENING THE LIFT BEGINS TO
DECLINE AS THE MID LEVEL TROUGH MOVES TO THE EAST AND THE UPPER
LEVEL TROUGH AXIS BEGINS TO MOVE THROUGH THE AREA. PRECIP. COMES TO
AN END THURSDAY MORNING AS THE LAST OF THE LINGERING LIFT FROM THE
MID LEVEL TROUGH MOVES OUT OF THE AREA.
THERE IS STILL SOME UNCERTAINTY AS TO WHAT THE PHASE OF THE PRECIP.
WILL BE FOR PORTIONS OF THE FORECAST SINCE MODELS DISAGREE WITH THE
AMOUNT OF SATURATION ABOVE THE -10C LEVEL...SO HAVE CHOSEN TO GO WITH
A RAIN/SNOW MIX AT THIS TIME WHICH WILL NEGATIVELY AFFECT FORECASTED
SNOWFALL AMOUNTS. IF TEMPERATURES COOL FURTHER SNOW-TO-LIQUID
RATIOS WILL INCREASE WHICH WILL ALSO CAUSE THE SNOWFALL AMOUNTS TO
INCREASE. CURRENTLY HAVE 1-4 INCHES FORECAST ACROSS THE AREA...WITH
THE HIGHER AMOUNTS OVER THE WESTERN PART OF THE AREA WHERE THE
BETTER LIFT WILL BE.
TEMPERATURES FOR THE PERIOD WILL BE BELOW NORMAL...BUT LOW
TEMPERATURES WILL NEAR NORMAL VALUES BY THE END OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1138 AM MDT SAT APR 13 2013
VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS AS A STRONG COLD
FRONT MOVES ACROSS THE REGION. WINDS WILL SHIFT FROM THE SOUTHWEST
TO THE NORTHWEST AND INCREASE TO 25 TO 35 MPH OVERNIGHT AND INTO
THE MORNING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
845 AM MDT SAT APR 13 2013
.UPDATE...
ISSUED AT 838 AM MDT SAT APR 13 2013
DENSE FOG CONTINUES ALONG AND JUST TO THE NORTH OF THE REPUBLICAN
RIVER VALLEY WITH MCK REPORTING LESS THAN A QUARTER MILE
VISIBILITIES. LOOKS LIKE THIS IS CONFINED TO NORTHERN RED WILLOW
AND NORTHEAST HITCHCOCK COUNTY...AND HAVE EXPANDED THE ADVISORY
FOR ANOTHER HOURS. GIVEN THE SMALL SCALE NATURE OF IT...SHOULD
BEGIN TO CLEAR OUT QUICKLY.
UPDATE ISSUED AT 608 AM MDT SAT APR 13 2013
UPDATED FOR A DENSE FOG ADVISORY FOR HITCHCOCK AND RED WILLOW.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 440 AM MDT SAT APR 13 2013
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION INTO THE
BEGINNING OF NEXT WEEK...FIRE WEATHER CONCERNS TODAY...AND WINDS
TODAY/TONIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN
FROM THE PACIFIC ACROSS NORTH AMERICA INTO THE ATLANTIC. CONTINUES TO
SHOW AN AMPLIFIED AND BLOCKY PATTERN FROM THE PACIFIC INTO EASTERN
NORTH AMERICA. VERY STRONG AND COLD SYSTEM IS DIGGING INTO SOUTHWEST
CANADA AND THE PACIFIC NORTHWEST. CURRENTLY WEST NORTHWEST TO
NORTHWEST RESIDES OVER THE REGION.
AT JET LEVEL...THE MODELS TENDED TO NOT HAVE THE JET AXIS THAT IS
PUNCHING INTO THE PACIFIC NORTHWEST TOO FAR NORTH AND EAST. THE NAM
AND GFS WERE DOING BEST ON THIS SEGMENT. THE MODELS TENDED TO HAVE
THE HEIGHT FIELD TOO FAR SOUTH AND EAST. OVERALL THE GFS...UKMET
AND CANADIAN WERE DOING THE BEST. THE RUC AND ECMWF WERE DOING
SLIGHTLY BETTER THAN THE NAM ON THE SURFACE WIND AND PRESSURE
FIELD. GFS AND CANADIAN WERE DOING A LITTLE BETTER THAN THE NAM ON
THE LOW LEVEL THERMAL FIELD.
PER THE INITIAL ANALYSIS AND THE PATTERN WE ARE IN...CHOSE THE
MID/UPPER LEVEL SOLUTIONS THAT WERE FURTHER SOUTH AND FASTER
INITIALLY FOLLOWED BY BEING FURTHER SOUTH AND WEST WITH THE INCOMING
LATER.
TODAY/TONIGHT...FIRST WHAT TO DO WITH THE FOG. MODELS...EVEN
MESOSCALE...HAVING DIFFICULTY GRABBING ONTO THE FOG. WHAT IS
COMPLICATING THINGS IS A CLOUD DECK ABOVE THIS THAT HAS BEEN CAUSING
VARIABILITY IN THE FOG FIELD. BASED ON LATEST TRENDS...CHOSE TO GO
AREAS OF FOG IN THE NORTHERN AND WESTERN SECTIONS AND PATCHY
ELSEWHERE. AS THE SUN COMES UP AND THE WINDS BEGIN TO INCREASE...
THE FOG SHOULD BURN OFF.
CROSS MOUNTAIN FLOW WILL CAUSE LEE TROUGH TO DEVELOP RAPIDLY. 3 HOUR
PRESSURE FALLS AND GRADIENT WOULD INDICATE AT LEAST BREEZY POSSIBLY
A LITTLE HIGHER CONDITIONS. THIS WILL HAVE AN AFFECT ON THE FIRE
WEATHER CONDITIONS. REFER TO THAT BELOW. GUIDANCE HAS BEEN COOL THE
LAST FEW DAYS AND NOT BY A LITTLE BIT...EVEN WITH CLOUDS AROUND. SO
TOOK THE WARMEST BIAS AND ADJUSTED IT WITH SOME BIAS/CHANGE IN
FORECAST 850 MB TEMPERATURE TO ARRIVE AT THE HIGHS.
MAIN JET AXIS STAYS NORTH AND WEST OF THE AREA. ALSO MAIN MID LEVEL
AND PV ANOMALY ARE STILL NORTH OF THE AREA. ALSO SOUNDINGS HAVE TOO
MUCH OF A DRY LAYER. THERE IS SOME SURFACE BASED INSTABILITY IN THE
AFTERNOON BUT THAT IS CAPPED. THERE IS NO ELEVATED INSTABILITY PLUS
IT IS CAPPED AS WELL EVEN IF THERE WAS ANY. SO WILL KEEP THIS
PERIOD DRY. HOWEVER...SOME KIND OF PRECIPITATION COULD GET CLOSE TO
THE FAR NORTHERN SECTION. CLOUD COVER AND WESTERLY WINDS/WARM AIR
ADVECTION IN ADVANCE OF THE COLD FRONT THAT ARRIVES LATER TONIGHT
WILL KEEP THE MINS RATHER MILD. THEY MAY NOT BE WARM ENOUGH. RATHER
SUNDAY/SUNDAY NIGHT...RATHER STRONG 3 HOUR PRESSURE RISE WILL CAUSE
BREEZY TO WINDY CONDITIONS BEHIND THE FRONT IN THE MORNING. LEFT
FRONT QUADRANT OF STRONG JET BEGINS TO AFFECT THE AREA AT THE
BEGINNING OF THE DAY AND THEN STARTS GRADUALLY LIFTING TO THE NORTH
AT THE END OF THE DAY. MID LEVEL COLD AIR ADVECTION/BAROCLINIC ZONE
ALONG WITH RATHER STRONG PV ANOMALY PUSHES ACROSS THE AREA AT THE
SAME WITH THE BEST LIFT AND MOISTURE OVER THE NORTHERN PORTION OF THE
AREA. SO EXPANDED POPS THROUGH THE DAY WITH THE HIGHEST IN THE
NORTHERN PORTION. COMBINATION OF CLOUD COVER/PRECIPITATION AND COLD
AIR ADVECTION WILL TEMPERATURES FROM RISING TOO MUCH AND WENT A
LITTLE BELOW GUIDANCE.
RIGHT REAR QUADRANT IS OVER THE AREA DURING THE NIGHT AND GETS
BETTER AS THE NIGHT WHERES ON AND AS THE MID LEVEL BAROCLINIC ZONE
REMAINS OVER THE AREA. PLUS ANOTHER SHORTWAVE TROUGH APPROACHES BY
LATER IN THE NIGHT. CURRENT FORECAST CAPTURES THIS SCENARIO NICELY
AND DID NOT CHANGE IT WITH GREATEST CHANCE OF PRECIPITATION
WILL BE IN THE NORTH WITH A CHANGEOVER OR MIXTURE OF PHASE EXPECTED
IN THE WEST.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF JET/JET AXIS REMAINS
OVER OR NEAR THE NORTHWEST HALF OF THE AREA THROUGH THE PERIOD.
LOW LEVEL UPSLOPE INCREASES THROUGH THE DAY AS STRONG MID LEVEL
SOUTHWEST FLOW ALOFT CAUSES LEE TROUGH TO STRENGTHEN. ALSO A COUPLE
OF SHORTWAVE TROUGHS MOVE THROUGH IN THIS FLOW. ALMOST EVERY
PARAMETER OF THE FORECAST FOR THIS PERIOD WILL BE PROBLEMATIC.
BECAUSE OF THE PROXIMITY OF THE JET AND MID LEVEL LIFT...KEPT THE
HIGHEST POPS IN THAT SECTION. HOWEVER...THERE IS A SHARP CUTOFF
BETWEEN A LOT OF CLOUDS/NO CLOUDS AND PRECIPITATION/NO
PRECIPITATION. SO ANY SUBTLE SHIFT NORTH OR SOUTH WILL GREATLY
AFFECT EVERY PARAMETER OF THE FORECAST. SO MADE ONLY MINOR
MODIFICATIONS. IF MODELS CONTINUE THE CURRENT TRENDS...THE
NORTHWEST HALF...ESPECIALLY THE CORNER...WILL NEED TO HAVE POPS
RAMPED UP CONSIDERABLY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT APR 13 2013
AN UPPER LEVEL TROUGH WILL DEEPEN OVER THE WESTERN CONUS TO START
OUT THE PERIOD. THE TROUGH WILL LINGER THERE THROUGH WEDNESDAY
BEFORE MOVING TOWARD THE AREA. WHILE THE UPPER LEVEL TROUGH REMAINS
SEMI STATIONARY LIFT FROM THE TROUGH WILL MOVE OVER THE AREA AND THE
ENVIRONMENT WILL BECOME SATURATED. THE BEST LIFT WILL MOVE OVER THE
AREA TUESDAY NIGHT AND WEDNESDAY. HAVE THE BEST PRECIP. CHANCES FOR
TUESDAY NIGHT DUE TO THE STRONGER FRONTOGENESIS OVER THE AREA
COMPARED TO WEDNESDAY.
ON WEDNESDAY THE MID LEVEL TROUGH MOVES OVER THE AREA AND WINDS
INCREASE AS AN ARCTIC COLD FRONT MOVES THROUGH. THE GUSTY WINDS MAY
CAUSE PATCHY BLOWING SNOW. DURING THE EVENING THE LIFT BEGINS TO
DECLINE AS THE MID LEVEL TROUGH MOVES TO THE EAST AND THE UPPER
LEVEL TROUGH AXIS BEGINS TO MOVE THROUGH THE AREA. PRECIP. COMES TO
AN END THURSDAY MORNING AS THE LAST OF THE LINGERING LIFT FROM THE
MID LEVEL TROUGH MOVES OUT OF THE AREA.
THERE IS STILL SOME UNCERTAINTY AS TO WHAT THE PHASE OF THE PRECIP.
WILL BE FOR PORTIONS OF THE FORECAST SINCE MODELS DISAGREE WITH THE
AMOUNT OF SATURATION ABOVE THE -10C LEVEL...SO HAVE CHOSEN TO GO WITH
A RAIN/SNOW MIX AT THIS TIME WHICH WILL NEGATIVELY AFFECT FORECASTED
SNOWFALL AMOUNTS. IF TEMPERATURES COOL FURTHER SNOW-TO-LIQUID
RATIOS WILL INCREASE WHICH WILL ALSO CAUSE THE SNOWFALL AMOUNTS TO
INCREASE. CURRENTLY HAVE 1-4 INCHES FORECAST ACROSS THE AREA...WITH
THE HIGHER AMOUNTS OVER THE WESTERN PART OF THE AREA WHERE THE
BETTER LIFT WILL BE.
TEMPERATURES FOR THE PERIOD WILL BE BELOW NORMAL...BUT LOW
TEMPERATURES WILL NEAR NORMAL VALUES BY THE END OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 552 AM MDT SAT APR 13 2013
INITIAL CONCERN WILL BE FOG AND STRATUS. AT THIS TIME LIFR
CONDITIONS ARE OCCURRING AT KMCK AND ARE EXPECTED TO CONTINUE
UNTIL 15Z. AT KGLD...STRATUS AND FOG ARE NOT CURRENTLY AFFECTING
THE SITE BUT ARE NOT THAT FAR AWAY AND WILL HAVE THE POTENTIAL TO
AFFECT THE SITES WITH MVFR CONDITIONS. AFTER THE FOG AND STRATUS
ARE GONE GUSTY SOUTHERLY WINDS ARE EXPECTED UNTIL EARLY EVENING.
THUNDERSTORMS LATER THIS EVENING AND OVERNIGHT APPEAR TO STAY
NORTH AT KMCK SO NO MENTION WAS MADE IN THE TAF. AFTER 06Z A
STRONG COLD FRONT WILL MOVE THROUGH AND CREATE GUSTY NORTHWEST
WINDS.
&&
.FIRE WEATHER...
ISSUED AT 440 AM MDT SAT APR 13 2013
CRITICAL FIRE WEATHER CONDITIONS WILL BE CLOSE IN CHEYENNE AND
KIT CARSON COUNTIES...ESPECIALLY THE WESTERN SECTIONS. CONDITIONS
WILL BE VERY CLOSE. IF THIS MORNINGS CLOUD COVER IS SLOW TO BURN
OFF THEN MIXING WILL BE SLOWER TO COMMENCE AS WELL. AT THIS TIME...
IT WILL BE CLOSE IF THE 3 HOUR REQUIREMENT WILL BE REALIZED. AT THIS
TIME CHOSE TO NOT ISSUE A HIGHLIGHT. BUT WILL CONTINUE TO MONITOR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR NEZ080-081.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
440 AM MDT SAT APR 13 2013
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 440 AM MDT SAT APR 13 2013
FORECAST CONCERNS WILL BE CHANCES OF PRECIPITATION INTO THE
BEGINNING OF NEXT WEEK...FIRE WEATHER CONCERNS TODAY...AND WINDS
TODAY/TONIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN
FROM THE PACIFIC ACROSS NORTH AMERICA INTO THE ATLANTIC. CONTINUES TO
SHOW AN AMPLIFIED AND BLOCKY PATTERN FROM THE PACIFIC INTO EASTERN
NORTH AMERICA. VERY STRONG AND COLD SYSTEM IS DIGGING INTO SOUTHWEST
CANADA AND THE PACIFIC NORTHWEST. CURRENTLY WEST NORTHWEST TO
NORTHWEST RESIDES OVER THE REGION.
AT JET LEVEL...THE MODELS TENDED TO NOT HAVE THE JET AXIS THAT IS
PUNCHING INTO THE PACIFIC NORTHWEST TOO FAR NORTH AND EAST. THE NAM
AND GFS WERE DOING BEST ON THIS SEGMENT. THE MODELS TENDED TO HAVE
THE HEIGHT FIELD TOO FAR SOUTH AND EAST. OVERALL THE GFS...UKMET
AND CANADIAN WERE DOING THE BEST. THE RUC AND ECMWF WERE DOING
SLIGHTLY BETTER THAN THE NAM ON THE SURFACE WIND AND PRESSURE
FIELD. GFS AND CANADIAN WERE DOING A LITTLE BETTER THAN THE NAM ON
THE LOW LEVEL THERMAL FIELD.
PER THE INITIAL ANALYSIS AND THE PATTERN WE ARE IN...CHOSE THE
MID/UPPER LEVEL SOLUTIONS THAT WERE FURTHER SOUTH AND FASTER
INITIALLY FOLLOWED BY BEING FURTHER SOUTH AND WEST WITH THE INCOMING
LATER.
TODAY/TONIGHT...FIRST WHAT TO DO WITH THE FOG. MODELS...EVEN
MESOSCALE...HAVING DIFFICULTY GRABBING ONTO THE FOG. WHAT IS
COMPLICATING THINGS IS A CLOUD DECK ABOVE THIS THAT HAS BEEN CAUSING
VARIABILITY IN THE FOG FIELD. BASED ON LATEST TRENDS...CHOSE TO GO
AREAS OF FOG IN THE NORTHERN AND WESTERN SECTIONS AND PATCHY
ELSEWHERE. AS THE SUN COMES UP AND THE WINDS BEGIN TO INCREASE...
THE FOG SHOULD BURN OFF.
CROSS MOUNTAIN FLOW WILL CAUSE LEE TROUGH TO DEVELOP RAPIDLY. 3 HOUR
PRESSURE FALLS AND GRADIENT WOULD INDICATE AT LEAST BREEZY POSSIBLY
A LITTLE HIGHER CONDITIONS. THIS WILL HAVE AN AFFECT ON THE FIRE
WEATHER CONDITIONS. REFER TO THAT BELOW. GUIDANCE HAS BEEN COOL THE
LAST FEW DAYS AND NOT BY A LITTLE BIT...EVEN WITH CLOUDS AROUND. SO
TOOK THE WARMEST BIAS AND ADJUSTED IT WITH SOME BIAS/CHANGE IN
FORECAST 850 MB TEMPERATURE TO ARRIVE AT THE HIGHS.
MAIN JET AXIS STAYS NORTH AND WEST OF THE AREA. ALSO MAIN MID LEVEL
AND PV ANOMALY ARE STILL NORTH OF THE AREA. ALSO SOUNDINGS HAVE TOO
MUCH OF A DRY LAYER. THERE IS SOME SURFACE BASED INSTABILITY IN THE
AFTERNOON BUT THAT IS CAPPED. THERE IS NO ELEVATED INSTABILITY PLUS
IT IS CAPPED AS WELL EVEN IF THERE WAS ANY. SO WILL KEEP THIS
PERIOD DRY. HOWEVER...SOME KIND OF PRECIPITATION COULD GET CLOSE TO
THE FAR NORTHERN SECTION. CLOUD COVER AND WESTERLY WINDS/WARM AIR
ADVECTION IN ADVANCE OF THE COLD FRONT THAT ARRIVES LATER TONIGHT
WILL KEEP THE MINS RATHER MILD. THEY MAY NOT BE WARM ENOUGH. RATHER
SUNDAY/SUNDAY NIGHT...RATHER STRONG 3 HOUR PRESSURE RISE WILL CAUSE
BREEZY TO WINDY CONDITIONS BEHIND THE FRONT IN THE MORNING. LEFT
FRONT QUADRANT OF STRONG JET BEGINS TO AFFECT THE AREA AT THE
BEGINNING OF THE DAY AND THEN STARTS GRADUALLY LIFTING TO THE NORTH
AT THE END OF THE DAY. MID LEVEL COLD AIR ADVECTION/BAROCLINIC ZONE
ALONG WITH RATHER STRONG PV ANOMALY PUSHES ACROSS THE AREA AT THE
SAME WITH THE BEST LIFT AND MOISTURE OVER THE NORTHERN PORTION OF THE
AREA. SO EXPANDED POPS THROUGH THE DAY WITH THE HIGHEST IN THE
NORTHERN PORTION. COMBINATION OF CLOUD COVER/PRECIPITATION AND COLD
AIR ADVECTION WILL TEMPERATURES FROM RISING TOO MUCH AND WENT A
LITTLE BELOW GUIDANCE.
RIGHT REAR QUADRANT IS OVER THE AREA DURING THE NIGHT AND GETS
BETTER AS THE NIGHT WHERES ON AND AS THE MID LEVEL BAROCLINIC ZONE
REMAINS OVER THE AREA. PLUS ANOTHER SHORTWAVE TROUGH APPROACHES BY
LATER IN THE NIGHT. CURRENT FORECAST CAPTURES THIS SCENARIO NICELY
AND DID NOT CHANGE IT WITH GREATEST CHANCE OF PRECIPITATION
WILL BE IN THE NORTH WITH A CHANGEOVER OR MIXTURE OF PHASE EXPECTED
IN THE WEST.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF JET/JET AXIS REMAINS
OVER OR NEAR THE NORTHWEST HALF OF THE AREA THROUGH THE PERIOD.
LOW LEVEL UPSLOPE INCREASES THROUGH THE DAY AS STRONG MID LEVEL
SOUTHWEST FLOW ALOFT CAUSES LEE TROUGH TO STRENGTHEN. ALSO A COUPLE
OF SHORTWAVE TROUGHS MOVE THROUGH IN THIS FLOW. ALMOST EVERY
PARAMETER OF THE FORECAST FOR THIS PERIOD WILL BE PROBLEMATIC.
BECAUSE OF THE PROXIMITY OF THE JET AND MID LEVEL LIFT...KEPT THE
HIGHEST POPS IN THAT SECTION. HOWEVER...THERE IS A SHARP CUTOFF
BETWEEN A LOT OF CLOUDS/NO CLOUDS AND PRECIPITATION/NO
PRECIPITATION. SO ANY SUBTLE SHIFT NORTH OR SOUTH WILL GREATLY
AFFECT EVERY PARAMETER OF THE FORECAST. SO MADE ONLY MINOR
MODIFICATIONS. IF MODELS CONTINUE THE CURRENT TRENDS...THE
NORTHWEST HALF...ESPECIALLY THE CORNER...WILL NEED TO HAVE POPS
RAMPED UP CONSIDERABLY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT APR 13 2013
AN UPPER LEVEL TROUGH WILL DEEPEN OVER THE WESTERN CONUS TO START
OUT THE PERIOD. THE TROUGH WILL LINGER THERE THROUGH WEDNESDAY
BEFORE MOVING TOWARD THE AREA. WHILE THE UPPER LEVEL TROUGH REMAINS
SEMI STATIONARY LIFT FROM THE TROUGH WILL MOVE OVER THE AREA AND THE
ENVIRONMENT WILL BECOME SATURATED. THE BEST LIFT WILL MOVE OVER THE
AREA TUESDAY NIGHT AND WEDNESDAY. HAVE THE BEST PRECIP. CHANCES FOR
TUESDAY NIGHT DUE TO THE STRONGER FRONTOGENESIS OVER THE AREA
COMPARED TO WEDNESDAY.
ON WEDNESDAY THE MID LEVEL TROUGH MOVES OVER THE AREA AND WINDS
INCREASE AS AN ARCTIC COLD FRONT MOVES THROUGH. THE GUSTY WINDS MAY
CAUSE PATCHY BLOWING SNOW. DURING THE EVENING THE LIFT BEGINS TO
DECLINE AS THE MID LEVEL TROUGH MOVES TO THE EAST AND THE UPPER
LEVEL TROUGH AXIS BEGINS TO MOVE THROUGH THE AREA. PRECIP. COMES TO
AN END THURSDAY MORNING AS THE LAST OF THE LINGERING LIFT FROM THE
MID LEVEL TROUGH MOVES OUT OF THE AREA.
THERE IS STILL SOME UNCERTAINTY AS TO WHAT THE PHASE OF THE PRECIP.
WILL BE FOR PORTIONS OF THE FORECAST SINCE MODELS DISAGREE WITH THE
AMOUNT OF SATURATION ABOVE THE -10C LEVEL...SO HAVE CHOSEN TO GO WITH
A RAIN/SNOW MIX AT THIS TIME WHICH WILL NEGATIVELY AFFECT FORECASTED
SNOWFALL AMOUNTS. IF TEMPERATURES COOL FURTHER SNOW-TO-LIQUID
RATIOS WILL INCREASE WHICH WILL ALSO CAUSE THE SNOWFALL AMOUNTS TO
INCREASE. CURRENTLY HAVE 1-4 INCHES FORECAST ACROSS THE AREA...WITH
THE HIGHER AMOUNTS OVER THE WESTERN PART OF THE AREA WHERE THE
BETTER LIFT WILL BE.
TEMPERATURES FOR THE PERIOD WILL BE BELOW NORMAL...BUT LOW
TEMPERATURES WILL NEAR NORMAL VALUES BY THE END OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM MDT FRI APR 12 2013
MOSTLY VFR CONDITIONS ARE EXPECTED AT MCK AND GLD. HOWEVER...
FOLLOWING THE RAIN THIS PAST EVENING...LOW LEVEL MOISTURE AND HIGHER
DEWPOINTS ARE BEING OBSERVED ACROSS THE REGION WITH AREAS OF LOW
CLOUDS AND FOG DEVELOPING AS THE WINDS ARE CURRENTLY CALM TO LIGHT
AND VARIABLE. SO UNTIL 14Z...CONDITIONS MAY VARY BETWEEN MVFR TO
LIFR. BY 14Z...WINDS ACROSS THE REGION SHOULD BEGIN TURNING TO THE
SOUTH AND INCREASE WITH DRYER AIR MOVING INTO THE REGION. AS THIS
OCCURS...EXPECT TO SEE A DECREASE IN THE AMOUNT OF FOG AND LOW CLOUDS
WITH SKIES BECOMING MOSTLY CLEAR BY MID DAY. BY 18Z...SOUTH WINDS
SHOULD ALSO BECOME GUSTY AND PERSIST INTO EARLY SATURDAY EVENING AS
HIGH CLOUDS BEGIN TO INCREASE ACROSS THE REGION AHEAD OF THE NEXT
APPROACHING LOW PRESSURE SYSTEM.
&&
.FIRE WEATHER...
ISSUED AT 440 AM MDT SAT APR 13 2013
CRITICAL FIRE WEATHER CONDITIONS WILL BE CLOSE IN CHEYENNE AND
KIT CARSON COUNTIES...ESPECIALLY THE WESTERN SECTIONS. CONDITIONS
WILL BE VERY CLOSE. IF THIS MORNINGS CLOUD COVER IS SLOW TO BURN
OFF THEN MIXING WILL BE SLOWER TO COMMENCE AS WELL. AT THIS TIME...
IT WILL BE CLOSE IF THE 3 HOUR REQUIREMENT WILL BE REALIZED. AT THIS
TIME CHOSE TO NOT ISSUE A HIGHLIGHT. BUT WILL CONTINUE TO MONITOR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...LOCKHART
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 PM EDT SAT APR 13 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 415 PM EDT SAT APR 13 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS CLOSED LO
CENTERED OVER ONTARIO TO THE S OF PERSISTENT BLOCKING RDG OVER NE
CANADA IN PREVAILING NEGATIVE NAO PATTERN. WITH DEEP MSTR SHOWN ON
12Z INL/GRB RAOBS...CYC FLOW...H85-7 COLD POCKET WITH H85 TEMPS AS
LO AS -10C TO -12C OVER THE WRN CWA...AND SHRTWVS ROTATING ARND THE
MAIN CLOSED LO...CLDS AND SHSN HAVE LINGERED OVER UPR MI...E
SPECIALLY ALONG SFC LO PRES TROF ASSOCIATED WITH ONE OF THESE
SHRTWVS THAT IS CROSSING THE CWA EARLY THIS AFTN. TEMPS REMAIN WELL
BLO NORMAL FOR MID APRIL. OVER FAR WRN MN INTO THE NRN PLAINS...A
SFC RDG AXIS AND DRY MID LVL AIR SHOWN ON THE 12Z BISMARCK RAOB ARE
CAUSING DRY WX EVEN THOUGH SOME LO CLDS LINGER WITH MSTR TRAPPED BLO
INVRN BASE AT H8 SHOWN ON THE BISMARCK SOUNDING. ANOTHER POWERFUL
SHRTWV IS MOVING ONSHORE INTO THE PAC NW WITH 00Z-12Z H3-5 HGT FALLS
UP TO 150-200M.
MAIN FCST CONCERNS THRU TNGT ARE FOCUSED ON SHSN/CLD TRENDS AS THE
UPR LO OVER ONTARIO SLOWLY FILLS AND SHIFTS TO THE E. FOCUS ON
SUN/SUN NGT SHIFTS TO TIMING AND IMPACT OF SHRTWV NOW MOVING INTO
THE PAC NW.
LATE TODAY/TNGT...AS UPR LO IN ONTARIO SLOWLY WEAKENS...H5 HGT IS
PROGGED TO RISE 120M OVER UPR MI BTWN 00Z-12Z SUN UNDER VIGOROUS
DEEP LYR QVECTOR DVGC. AS THE CYC NW FLOW WEAKENS...EXPECT LINGERING
SHSN LATE THIS AFTN/EVNG TO DIMINISH STEADILY THRU THE NGT AND END
IN THE EARLY MRNG HRS ON SUN. WITH SOME CLRG LATE AT LEAST OVER THE
W AND CENTRL AND LGT WINDS UNDER THE SFC RDG AXIS...EXPECT TEMPS TO
FALL INTO THE TEENS...WELL BLO NORMAL FOR THE SEASON. WITH CLDS/LLVL
MSTR LINGERING LONGER IN A PERSISTENT NW FLOW OVER THE E...THOSE
AREAS WL BE WARMER.
SUN/SUN NGT...EXPECT A DRY START TO THE DAY WITH SFC HI PRES RDG
SLOWLY DEPARTING TO THE E. BUT ANY MRNG SUNSHINE WL QUICKLY FADE
BEHIND INCRSG CLDS AS VIGOROUS ISENTROPIC ASCENT/DEEPER MSTR/SW FLOW
ALF BTWN THE DEPARTING HI AND INCRSG NEGATIVELY TILTED SHRTWV/SFC LO
MOVING THRU THE NRN PLAINS AND TOWARD MN LATE IN THE DAY OVERSPREADS
UPR MI. AS UPR DVGC/BAND OF H85-7 FGEN AHEAD OF ATTENDANT WARM FNT
MOVES IN AFT 18Z...EXPECT PCPN TO OVERSPREAD THE CWA BY 00Z MON...
ESPECIALLY OVER THE W HALF CLOSER TO SHARPER DYNAMICS AND WHERE
MOISTENING/H85 MSTR CNVGC IS MOST IMPRESSIVE. PTYPE WL BE A CONCERN
SUN AFTN/EVNG. NAM/GFS FCST SDNGS INDICATE SATURATED TEMP PROFILE WL
AT LEAST INITIALLY BE COMPLETELY SUB ZERO...BUT THEN SHOW ELEVATED
WARM LYR ABV SUB ZERO NEAR SFC LYR. WITH ELEVATED WARMING INITIALLY
LIFTING TEMPS ABV 0C IN THE H8-75 LYR...SUSPECT SLEET WL MIX WITH
THE SN. THESE FCST SDNGS ALSO SUG PCPN MAY BE AT LEAST MIXED WITH
SOME FZRA FOR A TIME LATE IN THE AFTN/EVNG OVER AT LEAST THE HIER
TERRAIN OF THE W HALF AS THE ELEVATED WARM LYR DEEPENS AND TEMPS IN
THE LOWER LYR WARM TOO MUCH FOR DROPS TO REFREEZE. BUT THESE SDNGS
ALSO APPEAR TO UNDERDO THE SFC WARMING IN THE AFTN FOLLOWING AT
LEAST SOME MRNG SUNSHINE. WITH SOME LINGERING LLVL DRY AIR...
EVAPORATIVE COOLING COULD MAINTAIN SUB 32 NEAR SFC WBLB TEMPS. BUT
THE FCST NEAR SFC SE FLOW IN THE ABSENCE OF HI PRES CENTER OVER
ONTARIO AS WELL AS ARRIVAL OF PCPN AT MAX HEATING TIME THIS LATE IN
THE SEASON WOULD ALSO TEND TO MINIMIZE THIS THREAT. HIER GFS MOS
TEMPS SEEM MORE APPROPRIATE FOR THE TEMPS FCST THAN RAW MODEL
GUIDANCE. FOR NOW...WL FCST A SN/SLEET MIX AT THE ONSET
TRANSITIONING TO RA SUN EVNG AS MUCH WARMER/MSTR LLVL AIR SURGES
INTO THE UPR LKS ON THE HEELS OF H85 SW WINDS FCST UP TO 60-70KTS BY
06Z MON. EXPECT LITTLE IF ANY FALL OF TEMPS SUN NGT. THE NW CWA WL
HAVE THE BEST CHC FOR SEEING A LONGER PERIOD OF WINTRY PCPN WITH
H85-75 TEMPS REMAINING BLO 0C THERE FOR A LONGER TIME. NOT OUT OF
THE QUESTION ADVY SN MAY FALL OVER THE HIER TERRAIN OF THE KEWEENAW
SUN AFTN/EVNG. NEGATIVELY TILTED APPEARANCE OF SHRTWV/VERY DIFFLUENT
SW FLOW ALF/MSTR SURGE WITH FCST PWAT 0.75 TO 1 INCH SUN EVNG...OR
UP TO 200 PCT OF NORMAL...INDICATE QPF NEAR 1 INCH IN SOME PLACES IS
ON TRACK. RUNOFF FM THIS RA IN THE PRESENCE OF LINGERING SN PILES
MAY CAUSE SOME PONDING OF WATER. ALTHOUGH FCST H85-5 LAPSE RATES ARE
NOT MUCH MORE UNSTABLE THAN MOIST ADIABATIC...DECIDED TO INCLUDE
MENTION OF ELEVATED TS UNDER THE MOST IMPRESSIVE MOISTENING/AXIS OF
H85 LLJ GIVEN IMPRESSIVE DYNAMICS/NEGATIVE TILT OF SHRTWV. ARRIVAL
OF DRY SLOT SUN NGT WL DIMINISH POPS SW-NE AFTER THE EVNG. IN
FACT...FCST SDNGS INDICATE THERE MAY BE SOME CLRG OVER THE SW LATE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 415 PM EDT SAT APR 13 2013
ACTIVE PATTERN ACROSS THE CONUS CONTINUES INTO NEXT WEEKEND AS A
LARGE SCALE UPPER TROUGH MOVES FROM THE W COAST MON TO THE CENTRAL
CONUS BY NEXT SAT...WITH PIECES OF SMALLER SCALE ENERGY EJECTING OFF
THE TROUGH THROUGH THE REGION.
STARTING THE PERIOD OFF 12Z MON...A STACKED CLOSED LOW WILL BE OVER
NRN MN WITH AN OCCLUDED FRONT FROM THE LOW TO NRN LAKE
SUPERIOR...AND THE ASSOCIATED WARM FRONT EXTENDING E FROM NRN LAKE
SUPERIOR INTO ONTARIO AND THE COLD FRONT FROM NRN LAKE SUPERIOR TO
FAR ERN UPPER MI. AT THIS POINT...THE PRECIP THAT MOVED OVER THE CWA
AHEAD OF THE COLD FRONT WILL BE MOSTLY E OF THE CWA. THE DRY SLOT
BEHIND THE COLD FRONT WILL BRING VERY DRY AIR INITIALLY THROUGH MOST
OF THE SOUNDING...BUT WRAP AROUND LOW LEVEL MOISTURE BELOW 800MB WILL
RETURN TO AT LEAST NW UPPER MI /MODELS DIFFER ON THE AREAL EXTENT OF
THE MOISTURE/ AS THE LOW MOVES N OF LAKE SUPERIOR TO JAMES BAY BY
12Z TUE. THIS MAY RESULT IN SOME CONVECTIVE WINTRY MIX SHOWERS WHERE
THERE IS SUFFICIENT LOW LEVEL MOISTURE TO TAP INTO STEEP LOW LEVEL
LAPSE RATES...MAINLY MON INTO EARLY MON NIGHT. WILL INTRODUCE SOME
LOW END POPS FOR THIS POSSIBILITY TO NW UPPER MI. WITH THE STEEP LOW
LEVEL LAPSE RATES...WE SHOULD SEE MIXING TO AROUND 800MB ON
MON...AND WITH SW 800-900MB WINDS AOA 40KTS...IT WILL MAKE FOR GUSTY
SFC WINDS. MAY END UP NEEDING A WIND ADVISORY IN SOME
LOCATIONS...BUT TOO EARLY TO SAY WHERE AT THIS POINT AS MODELS DO
VARY IN STRENGTH AND LOCATION OF BEST LOW LEVEL WINDS. COULD ALSO
SEE SOME DOWNSLOPE ENHANCEMENT OF THE WINDS...ESPECIALLY NEAR LAKE
SUPERIOR ON MARQUETTE COUNTY WITH THE SW WINDS.
EVEN THOUGH 850MB TEMPS DROP BY 7C OR MORE FROM SUN NIGHT INTO
MON...SHOULD STILL BE ABLE TO SEE TEMPS WARM INTO THE 40S /EVEN
AROUND 50 OVER THE SCENTRAL CWA/ MON AFTERNOON DUE TO GOOD LOW LEVEL
MIXING MIXING. THESE WARMER TEMPS AND GUSTY WINDS...COMBINED WITH
SUNSHINE /ESPECIALLY OVER THE CENTRAL AND ERN CWA/ AND RAIN SUN
NIGHT...COULD SEE SOME MELTING OF THE SNOWPACK MON. PROBABLY WILL
NOT LOSE TOO MUCH SNOW PACK...BUT SOME REDUCTION IS CERTAINLY
POSSIBLE.
THE FRONTAL ZONE STALLS WELL TO OUR S THROUGH TUE NIGHT AS UPPER
RIDGING BUILDS OVER THE CWA. THE NRN STREAM JET THEN PUSHES THROUGH
THE CWA TUE NIGHT AS THE UPPER TROUGH OVER THE WRN CONUS SHARPENS UP
AND MOVES TO THE INTERMOUNTAIN WEST. NRN AND SRN STREAM INTERACTION
ALONG THE SRN END OF THE TROUGH WILL CAUSE IT TO DEEPEN AND SHARPEN
UP FURTHER AS IT MOVES E FROM HUDSON BAY TO MN TO TX BY 00Z FRI AS
UPPER RIDGING BUILDS E OF THE CWA. BY LATE WED...WITH THE PRESSURE
GRADIENT TIGHTENING...THE NOW PHASED SRN AND NRN JET STREAM ARCING
FROM W TO N OF THE CWA WILLS STRENGTHEN TO AOA 120KTS. THIS LEADS TO
RAPID SFC CYCLOGENESIS ALONG THE FRONTAL ZONE OVER MO. THE 850MB
FRONTAL ZONE WILL MOVE N INTO THE CWA WED...AND WHEN COMBINED WITH
THE FORCING FROM THE RIGHT ENTRANCE REGION OF THE UPPER JET WILL
LEAD TO PRECIP BY WED AFTERNOON. THE EXACT PLACEMENT AND TYPE OF
PRECIP REMAINS IN QUESTION DUE TO MODEL DISAGREEMENT...BUT GENERALLY
EXPECT SNOW OVER THE NW CWA AND RAIN OVER THE SE CWA...AND THIS
PRECIP SHOULD BE RELATIVELY MINOR ACCUMULATION WISE. PRECIP AMOUNTS
THEN BECOME MORE OF A CONCERN WED NIGHT AND THU AS THE SFC LOW MOVES
ACROSS LAKE MI AND LOWER MI LATE WED NIGHT INTO THU. THE 12Z/13 GFS
AND 00Z/13 ECMWF AGREE PRETTY WELL ON BRINGING THE SFC LOW ACROSS
NRN LOWER MI...BUT THE ECMWF IS ABOUT 6 HOURS FASTER THAN THE GFS AND
NOT AS DEEP WITH THE SFC LOW. OVERALL...A MINOR DIFFERENCE THIS FAR
OUT WITH THE VOLATILE NATURE OF THIS TYPE OF SYSTEM. THINK THAT
MODELS ARE NOT SETTLED AND THINGS WILL CHANGE OVER THE NEXT FEW
DAYS...BUT THE GENERAL IDEA SEEMS GOOD. AT THIS POINT...THERMAL
FIELDS ARE SIMILAR BETWEEN THE MODELS...WITH TEMPS COLD ENOUGH FOR
MAINLY SNOW OVER THE NW CWA...AND MAINLY RAIN OVER THE SE CWA...AT
LEAST UNTIL COLD AIR ARRIVES LATE THU INTO THU NIGHT. SIGNIFICANT
PRECIP AMOUNTS WILL BE POSSIBLE AS MODELS SHOW BETWEEN 0.3 INCHES
AND AROUND 1 INCH OF QPF...BUT VARY ON THE EXACT PLACEMENT OF THIS
PRECIP. STILL SOMETHING TO KEEP A CLOSE EYE ON.
BY LATE THU INTO FRI...ADDITIONAL ENERGY ROUNDING THE BASE OF THE
UPPER TROUGH CAUSES THE SFC LOW TO STALL SOME /OR MORE REDEVELOP ON
THE SW SIDE/. THE MAIN IMPACT THIS HAS ON OUR WEATHER IS TO KEEP
BETTER MOISTURE AND A SFC TROUGH STRETCHED BACK ACROSS LAKE SUPERIOR
AS THE UPPER TROUGH AND MUCH COLDER AIR MOVES ACROSS THE CWA. IF
THIS DOES INDEED COME TO REALITY...LAKE EFFECT SNOW WOULD BE THE
RESULT AS 850MB TEMPS FALL TO AROUND -13C AHEAD OF THE UPPER TROUGH.
LES SHOULD THEN CONTINUE INTO AT LEAST PART OF SATURDAY...BUT
CONFIDENCE IN OVERALL PATTERN DECLINES RAPIDLY THROUGH THE DAY SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 147 PM EDT SAT APR 13 2013
LIGHT TO SOMETIMES MODERATE SNOW SHOWERS AFFECTING MAINLY IWD AND
SAW WILL DIMINISH THROUGHOUT THE AFTERNOON AS A TROUGH PASSES
THROUGH AND MOVE SOUTH OF THE AREA. EXPECT TEMPORARY VIS
RESTRICTIONS IN THE LIFR RANGE TO IMPROVE TO VFR VIS AT ALL SITES BY
LATER AFTERNOON. CLOUDS WILL START TO THIN OUT BY THIS
EVENING...THOUGH UPSLOPE FLOW AROUND CMX MAY KEEP A FEW HIGH-END
MVFR CLOUDS AROUND OVERNIGHT.
AN APPROACHING SYSTEM WILL BEGIN TO SPREAD MID-LEVEL CLOUDS ACROSS
UPPER MI LATE SUNDAY MORNING INTO THE AFTERNOON. IWD CAN EXPECT TO
SEE A MIX OF HEAVY SLEET...SNOW AND RAIN BY 21Z SUNDAY. CMX AND SAW
SHOULD SEE THE SAME BY 00Z MONDAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT SAT APR 13 2013
NW WINDS UP TO 20-25 KTS OVER THE E HALF THIS EVENING WILL BECOME
LIGHT INTO SUN MORNING WITH ARRIVAL/PASSAGE OF HI PRES RIDGE AXIS.
AS THE NEXT LO PRES SYSTEM MOVES FROM THE NORTHERN PLAINS ON SUN
THRU MN SUN NIGHT AND THE PRES GRADIENT TIGHTENS...A STRONGER E WIND
VEERING SE UP TO 30 KTS WILL DEVELOP. OPTED TO ISSUE A GALE WATCH
FOR THE FAR W AND PORTIONS OF THE NCENTRAL AND E FOR LATE SUN/SUN
NIGHT WHERE THE EXPECTED FLOW IS ENHANCED BY TERRAIN INFLUENCES.
AS THE LOW PRESSURE SYSTEM MOVES FROM NORTHERN MN MONDAY MORNING TO
JAMES BY BY TUESDAY MORNING...STRONG SOUTHWEST WINDS MAY GUST TO 35
KNOTS OVER THE WESTERN HALF OF LAKE SUPERIOR MONDAY INTO MONDAY
NIGHT. WINDS THEN DECREASE TUESDAY INTO WEDNESDAY BEFORE INCREASING
OUT OF THE N WEDNESDAY NIGHT INTO FRIDAY WHEN GALES MAY BE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY EVENING THROUGH LATE SUNDAY NIGHT FOR
LSZ264-266.
GALE WATCH FROM SUNDAY EVENING THROUGH LATE SUNDAY NIGHT FOR
LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...TK
MARINE...KC/TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
149 PM EDT SAT APR 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM EDT SAT APR 13 2013
LAKE ENHANCEMENT HAVING A TOUGH TIME STARTING EARLY THIS
MORNING...EXCEPT FOR A BAND JUST WEST OF IWD. SEEMS LIKE THE MAIN
PROBLEM WITH ORGANIZATION IS LACK OF ANY SIGNIFICANT LOW LEVEL
CONVERGENCE DUE THE VERY WEAK WIND FIELDS OVER THE LAND. AGAIN...THE
EXCEPTION TO THIS IS OVER THE WEST WHERE CYCLONIC NNE FLOW IS QUITE
FAVORABLE FOR THE IWD AREA. LOCAL HI RES NWP AND ALONG WITH THE RAP
AND HRRR SUGGEST THAT AS THE LES WILL BECOME A LITTLE MORE ORGANIZED
BETWEEN 09Z AND 12Z AS THE SFC TROUGH OVER THE LAKE MOVES SOUTH AND
THE INVERSION DEEPENS TO NEARLY 8000FT AS WEAK Q-VECTOR CONVERGENCE
ASSOCIATED WITH THE UPPER TROUGH AXIS MOVES ACROSS THE AREA.
STILL...DESPITE THE EXPECTED INCREASED COVERAGE OF SNOW THIS
MORNING...THE FACT REMAINS THAT THERE IS NOT MUCH SNOW ONGOING RIGHT
NOW OTHER THAN FAR WESTERN GOGEBIC COUNTY...AND ANY ADDITIONAL
ACCUMULATION IN THE KEWEENAW AND IN THE NORTH CENTRAL AREAS WILL
ONLY AMOUNT TO AN INCH OR TWO. AS SUCH...HAVE OPTED TO DROP THE
ADVISORY FOR THOSE AREAS BUT KEEP IT FOR THE GOGEBIC AND ONTONAGON
THROUGH 15Z. SINCE IT IS NOT REALLY SNOWING IN THE CURRENT ADVISORY
AREA EXCEPT ACROSS THE FAR WEST...IT JUST DOES NOT SEEM PRUDENT TO
KEEP THE ADVISORY AT THIS TIME FOR MQT/BARAGA AND THE KEWEENAW FOR
ONLY AN ADDITIONAL INCH OR TWO OF ADDITIONAL SNOW. WILL STILL
FORECAST 2 TO LOCALLY 4 INCHES IN THE IRONWOOD/PORCUPINE MTNS AREA
FOR THIS MORNING AS THE SOUNDINGS LOOK QUITE FAVORABLE FOR A BRIEF
PERIOD OF MODERATE SNOWFALL WITH THE RISING INVERSION AND BETTER
DENDRITIC SNOW GROWTH WITH THE TOP OF THE INVERSION AROUND -18C.
AS THE LOW PULLS OUT...RIDGING SHOULD SLOWLY BUILD IN FROM THE WEST
THIS AFTERNOON INTO TONIGHT. THIS SHOULD ALLOW THE LES TO END FROM
WEST TO EAST DURING THE DAY AND INTO THIS EVENING. ANY LES THIS
EVENING WOULD BE FOCUSED IN AREAS EAST OF MUNISING DUE TO THE NW PBL
FLOW. HOWEVER...DO NOT EXPECT THIS LES TO LAST TOO LONG DUE TO THE
RIDGE BUILDING AND AND RAPIDLY DIMINISHING MOISTURE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM EDT SAT APR 13 2013
NAM SHOWS A 500 MB SHORTWAVE RIDGE OVER THE UPPER GREAT LAKES 12Z
SUN WITH A CLOSED LOW OVER THE NORTHERN ROCKIES. THIS CLOSED LOW
QUICKLY MOVES INTO THE NORTHERN PLAINS LATE SUN AND AFFECTS THE
UPPER GREAT LAKES SUN NIGHT BEFORE IT HEADS NORTHEAST AND SHEARS OUT
TO THE NORTH ON MON. NAM BRINGS IN SOME DEEPER MOISTURE SUN
AFTERNOON ALONG WITH 850-500 MB Q-VECTOR CONVERGENCE WHICH REMAINS
THROUGH SUN NIGHT BEFORE AREA GETS DRY SLOTTED ON MON. NAM SHOWS
SOME STRONG ISENTROPIC LIFT ON I280K-I295K SURFACES WITH DEEP
MOISTURE SUN EVENING WITH THE LIFT MOVING OUT BY 12Z MON. GFS AND
ECMWF SHOW ABOUT THE SAME THING AS WELL. LOOKS LIKE MON THAT MOST OF
THE CWA GETS DRY SLOTTED AND SHOULD HAVE BREEZY CONDITIONS ON
MONDAY. WITH DRY SLOT MOVING THROUGH...THINK THERE WILL BE SOME
SUNSHINE WITH SW WINDS ALLOWING SOME DOWNSLOPING TO OCCUR. FOR THIS
REASON AND A BIT MORE SUNSHINE...RAISED SOME HIGH TEMPERATURES A BIT
AND COULD SEE A FEW 50S FOR HIGHS ON MONDAY.
LOOKED AT A FEW THINGS AND AGREE WITH PREVIOUS SHIFTS THINKING OF
HAVING SOME SLEET...RAIN AND SNOW MENTIONED FOR PCPN TYPE FOR SUN
AFTERNOON AND EVENING BEFORE WARMING TAKES PLACE TO SWITCH ALL THE
PCPN OVER TO ALL RAIN LATE SUN NIGHT INTO MONDAY. COULD SEE
0.50-0.90 OF QPF FROM THIS EVENT WHICH WILL EQUATE OUT TO LESS THAN
TWO INCHES OF TOTAL SNOW AS THINGS ARE WARMING. WITH PCPN HOLDING
OFF UNTIL SUNDAY AFTERNOON...THINGS WILL BE WARM ENOUGH TO NOT HAVE
THE PCPN BE ALL SNOW OR SLEET. KEPT CATEGORICAL POPS IN FOR SUNDAY
NIGHT AND THEN HAVE DRY SLOT MOVING INTO THE WEST AND CENTRAL AREAS
FOR MON.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB CLOSED LOW IN JAMES
BAY 12Z TUE WITH TROUGHING EXTENDING FROM THAT BACK TO THE NORTHERN
PLAINS AND SOUTHERN ROCKIES. TROUGHING SLOWLY MOVES EAST 12Z WED AND
OUT INTO THE PLAINS 12Z THU AND INTO THE UPPER GREAT LAKES 12Z FRI.
ACTIVE AND COLD WEATHER PATTERN LOOKS TO CONTINUE WITH TEMPERATURES
REMAINING WELL BELOW NORMAL AND WETTER THAN NORMAL CONDITIONS WILL
ALSO CONTINUE THIS FORECAST PERIOD. TUE AND TUE NIGHT LOOK DRY FOR
NOW BEFORE NEXT STRONG SYSTEM ARRIVES FOR WED INTO FRI. THIS NEXT
SYSTEM LOOKS LIKE A MESS FOR PCPN TYPE WITH RAIN/SNOW MIX WITH
MOSTLY SNOW FALLING AS COLDER AIR COMES IN BEHIND IT ESPECIALLY FOR
FRI WITH THE ECMWF SHOWING 850 MB TEMPERATURES FALLING TO -12C TO
-14C. CONTINUED HIGH CHANCE POPS TO LIKELYS FOR THIS SYSTEM LOOK
GOOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 147 PM EDT SAT APR 13 2013
LIGHT TO SOMETIMES MODERATE SNOW SHOWERS AFFECTING MAINLY IWD AND
SAW WILL DIMINISH THROUGHOUT THE AFTERNOON AS A TROUGH PASSES
THROUGH AND MOVE SOUTH OF THE AREA. EXPECT TEMPORARY VIS
RESTRICTIONS IN THE LIFR RANGE TO IMPROVE TO VFR VIS AT ALL SITES BY
LATER AFTERNOON. CLOUDS WILL START TO THIN OUT BY THIS
EVENING...THOUGH UPSLOPE FLOW AROUND CMX MAY KEEP A FEW HIGH-END
MVFR CLOUDS AROUND OVERNIGHT.
AN APPROACHING SYSTEM WILL BEGIN TO SPREAD MID-LEVEL CLOUDS ACROSS
UPPER MI LATE SUNDAY MORNING INTO THE AFTERNOON. IWD CAN EXPECT TO
SEE A MIX OF HEAVY SLEET...SNOW AND RAIN BY 21Z SUNDAY. CMX AND SAW
SHOULD SEE THE SAME BY 00Z MONDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EDT SAT APR 13 2013
BROAD LOW PRESSURE JUST EAST OF THE AREA WILL MOVE OUT TODAY. STILL
SOME GUSTY N-NW WINDS ACROSS THE WEST LAKE THIS MORNING...BUT THE
EXPECTATION IS THAT THESE WILL DIMINISH LATER THIS AFTERNOON INTO
THIS EVENING AS THE RIDGE OVER THE UPPER MISSISSIPPI VALLEY MOVES
ACROSS THE LAKE. AS LOW PRESSURE OVER THE PLAINS DEVELOPS TODAY AND
MOVES NORTH...EXPECT E-NE WINDS TO INCREASE SUNDAY AFTERNOON AND
NIGHT. COULD NOT RULE OUT NE GALES SUNDAY EVENING ACROSS THE
WEST...THEN SE GALES ACROSS THE EAST HALF LATE SUNDAY NIGHT INTO
EARLY MONDAY MORNING...BUT THEY WOULD LIKELY BE MARGINAL AND SHORT
LIVED. WINDS TURN SW BEHIND AN OCCLUDED FRONT ON MONDAY...THEN
GRADUALLY TURN W AND NW ON TUE AS HIGH PRESSURE BUILDS BACK IN. NE
WINDS RETURN WED AND PERHAPS ANOTHER STORM SYSTEM FOR LATE IN THE
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...07
AVIATION...TK
MARINE...MRD
AREA FORECAST DISCUSSION
NWS DULUTH MN
1241 PM CDT SAT APR 13 2013
.AVIATION...18Z TAFS
A MIX OF CEILINGS FROM 2500-3500FT COVERED THE NORTHLAND...DUE TO
A STRATOCUMULUS DECK THAT QUICKLY DEVELOPED THIS MORNING. WE
EXPECT CEILINGS CONTINUE TO SLOWLY RISE THIS AFTERNOON...BUT THERE
ALSO COULD BE A FEW SNOW SHOWERS THAT BRING MORE MVFR CONDITIONS
BRIEFLY. IT SHOULD BECOME MOSTLY VFR THIS EVENING...THEN AN
APPROACHING LOW PRESSURE SYSTEM WILL DROP CEILINGS AND EVENTUALLY
VSBYS AS PRECIPITATION MOVES NORTH. THE PRECIPITATION SHOULD START
AS MOSTLY SNOW...AND AFFECT KBRD FIRST...THEN KHYR/KDLH AND
EVENTUALLY KHIB/KINL. KHYR HAS THE BEST CHANCE AT SEEING A
MIXTURE.
WINDS WILL TURN OUT OF THE EAST LATER TONIGHT...AND INCREASE AND
BECOME GUSTY DURING THE DAY SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 1002 AM CDT SAT APR 13 2013/
UPDATE...
THE MAIN CHALLENGE FOR THIS UPDATE TO THE FORECAST IS THE
LINGERING SNOW IN NW WISCONSIN. OBSERVATIONS FROM
IRONWOOD AND ASHLAND...THE CURRENT RADAR...AND CALLS FROM
OBSERVERS SUGGEST THIS SNOW IS LINGERING LONGER THAN PREVIOUSLY
THOUGHT IT WOULD. THE SNOW IS REDUCING VISIBILITY QUITE A BIT AT
TIMES. THE LATEST NAM AND HRRR MODELS SHOW IT THE HEAVIER SNOW
BANDS LINGERING LONGER...SO I EXTENDED THE WINTER WEATHER ADVISORY
FOR IRON AND ASHLAND COUNTIES TILL NOON. I WOULD NOT BE SURPRISED
IF SOME AREAS GET AN ADDITIONAL 1 TO 2 INCHES NEAR AND ALONG THE
GOGEBIC RANGE.
OTHERWISE...THE REST OF THE FORECAST FOR TODAY IS RELATIVELY
QUIET. I LOWERED CLOUD COVER THIS MORNING IN SOME AREAS THAT HAVE
SOME PARTIAL CLEAR...BUT I THINK THE FORECAST AREA WILL MOSTLY
HAVE CLOUDY OR MOSTLY CLOUDY SKIES TODAY.
THE FOCUS WHEN I MAKE MY NEW FORECAST THIS AFTERNOON WILL OF
COURSE BE THE NEXT SPRINGTIME WINTER STORM THAT IS POISED TO
STRIKE THE NORTHLAND SUNDAY AND SUNDAY NIGHT. COMPARED TO WHAT I
SAW IN THE 12Z MODELS YESTERDAY...THE SNOWFALL ACROSS NE MINNESOTA
IN THE 00Z MODELS SNOWFALL SEEMS TO BE LOWER THAN YESTERDAY. IF
THE NEW 12Z MODELS REMAIN FAIRLY CONSISTENT AND AGREEABLE BETWEEN
EACH OTHER...THAN WE WILL PROBABLY ISSUE WINTER STORM WARNINGS AND
ADVISORIES FOR THIS NEXT ROUND OF SNOW.
PREV DISCUSSION... /ISSUED 711 AM CDT SAT APR 13 2013/
AVIATION.../12Z TAF ISSUANCE/
THE LARGE WINTER STORM THAT MOVED THROUGH OVER THE PAST FEW DAYS
WILL GRADUALLY PULL OUT OVER THE NEXT 24 HOURS. THE RESULT WILL BE
WIDELY VARYING CLOUD HEIGHTS AND VISIBILITIES AS THE LOW MOVES
EAST AND THE CLOUDS AND SNOW SHOWERS TRY TO BREAK UP. CONDITIONS
WILL VARY BETWEEN VFR AND MVFR AND LOCALLY IFR.
SHORT TERM...
CURRENT...VERTICALLY STACKED CIRCULATION OVER ERN LAKE SUPERIOR
IS MAINTAINING A MOIST CYCLONIC FLOW OVER CWA EARLY THIS MORNING.
ABUNDANCE OF CLOUDS WITH SOME WIND AND LIGHT PRECIP HAS KEPT
TEMPS ACROSS CWA FAIRLY UNIFORM. LOWEST READINGS ARE IN THE MN
ARROWHEAD WITH TEENS ...AND 20S ELSEWHERE.
TODAY...WIDESPREAD AREA OF LIGHT SNOW ACROSS MN ZONES WILL ADVECT
EASTWARD INTO WISC ZONES THROUGH REMAINDER OF MORNING. WILL LET WSW
EXPIRE IN BAYFIELD COUNTY AT 12Z AND EXTEND ASHLAND/IRON COUNTIES
TIL 15Z. ALTHOUGH CYCLONIC FLOW WILL PERSIST SFC/ALOFT TODAY...DEEP
LAYER RH IS EXPECTED TO GRADUALLY DIMINISH. LT SNOW/SNOW SHOWERS
WILL PERSIST THROUGH MID AFTN OVER MN ZONES..AND PERHAPS UNTIL LATE
AFN OVER WISC ZONES. MAX TEMPS REMAIN WELL BLO CLIMO WITH MID 30S
PREVAILING.
TONIGHT...PROGRESSIVE FLOW ALOFT WILL ALLOW MID LVL RIDGING TO PUSH
INTO CWA FROM THE SOUTHWEST OVERNIGHT. AN ELONGATED AREA OF LOW
PRESSURE AT THE SFC WILL STRETCH FROM CTRL SD TO ERN NEB BY 12Z
SUNDAY. CLOUDS WILL INCREASE OVER SWRN CWA WITH SNOW DEVELOPING
AROUND 09Z AS AN AREA OF WARM FRONTOGENESIS INCREASES.
TOMORROW...MDLS AGREE THAT A DUAL LOBE SFC PRESS PATTERN WILL
CONTINUE TO MOVE NORTHEAST. THE NRN LOW WILL MOVE TOWARDS THE ND/SD
BORDER BY 00Z WHILE THE SECONDARY LOW WILL MIGRATE TO SERN MN. AN
AREA OF STRONG 85H FRONTOGENESIS WILL BE RESPONSIBLE FOR AN AREA OF
MODERATE INTENSITY SNOWFALL MAKING ITS WAY ACROSS MOST OF MN ZONES
EXCEPT ERN ARROWHEAD. A GENERAL 3 TO 6 INCH SNOWFALL APPEARS
INCREASING LIKELY FROM THE BRAINERD LAKES REGION TO TWIN PORTS AND
POINTS NORTH AND WEST. A TRANSITION IN PTYPE SHOULD OCCUR IN THE SRN
THIRD OF THE CWA BY AFTN AS ICE PELLETS AND RAIN BEGIN TO DEVELOP.
WITH PROSPECT FOR ACCUMULATING SNOW TO CONTINUE BEYOND THIS PERIOD
WILL LET DAY SHIFT DECIDE IF AN ADVISORY OR WARNING WILL BE ISSUED
FOR SUNDAY/SUNDAY NIGHT EVENT.
PREV DISCUSSION... /ISSUED 332 AM CDT SAT APR 13 2013/
EXTENDED...SUNDAY NIGHT THROUGH SATURDAY...
THE STRONG LOW PRESSURE SYSTEM THAT WILL MOVE THROUGH LATE IN THE
WEEKEND WILL CONTINUE TO AFFECT THE NORTHLAND INTO SUNDAY NIGHT.
THERE WILL LIKELY STILL BE SOME ACCUMULATION INTO THE
NIGHT...ESPECIALLY ACROSS NE MN. A MIX IS EXPECTED FROM EC MN INTO
PORTIONS OF NW WI...WITH MAINLY RAIN ACROSS THE FAR SE. STRONG WINDS
WILL GRADUALLY SUBSIDE AS THE SURFACE LOW MOVES INTO NORTHERN
MN...BUT STRONG NW TO W WINDS WILL THEN DEVELOP ON THE BACKSIDE OF
THE LOW ON MONDAY...WITH WRAP AROUND SNOW SHOWERS CONTINUING.
ANOTHER STRONG SYSTEM WILL THEN AFFECT THE AREA TOWARD THE MIDDLE OF
NEXT WEEK...BUT THE MODELS HAVE BACKED OFF ON WIDESPREAD AND HEAVY
PRECIPITATION WITH THIS SYSTEM. STILL LOOKS LIKE IT COULD BRING SOME
ACCUMULATION...BUT THE GEM IS THE MODEL WITH THE HEAVIEST
PRECIPITATION. IN ALL...IT LOOKS LIKE GENERALLY COOLER THAN NORMAL
TEMPERATURES THROUGH THE EXTENDED TIME PERIOD. THE GFS DOES BRING A
SURFACE LOW ACROSS MN ON FRIDAY NIGHT AND SATURDAY...BUT THE ECMWF
HAS HIGH PRESSURE AT THE SAME TIME.
&&
.POINT TEMPS/POPS...
DLH 23 34 28 39 / 30 100 100 40
INL 16 38 28 38 / 0 90 100 60
BRD 25 36 27 40 / 90 100 70 40
HYR 20 38 30 42 / 50 100 90 10
ASX 19 37 31 42 / 10 100 100 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING
FOR MNZ010>012-018>021-026.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
MNZ025-033>036.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ037.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
147-148.
&&
$$
SHORT TERM...GROCHOCINSKI
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1002 AM CDT SAT APR 13 2013
.UPDATE...
THE MAIN CHALLENGE FOR THIS UPDATE TO THE FORECAST IS THE
LINGERING SNOW IN NW WISCONSIN. OBSERVATIONS FROM
IRONWOOD AND ASHLAND...THE CURRENT RADAR...AND CALLS FROM
OBSERVERS SUGGEST THIS SNOW IS LINGERING LONGER THAN PREVIOUSLY
THOUGHT IT WOULD. THE SNOW IS REDUCING VISIBILITY QUITE A BIT AT
TIMES. THE LATEST NAM AND HRRR MODELS SHOW IT THE HEAVIER SNOW
BANDS LINGERING LONGER...SO I EXTENDED THE WINTER WEATHER ADVISORY
FOR IRON AND ASHLAND COUNTIES TILL NOON. I WOULD NOT BE SURPRISED
IF SOME AREAS GET AN ADDITIONAL 1 TO 2 INCHES NEAR AND ALONG THE
GOGEBIC RANGE.
OTHERWISE...THE REST OF THE FORECAST FOR TODAY IS RELATIVELY
QUIET. I LOWERED CLOUD COVER THIS MORNING IN SOME AREAS THAT HAVE
SOME PARTIAL CLEAR...BUT I THINK THE FORECAST AREA WILL MOSTLY
HAVE CLOUDY OR MOSTLY CLOUDY SKIES TODAY.
THE FOCUS WHEN I MAKE MY NEW FORECAST THIS AFTERNOON WILL OF
COURSE BE THE NEXT SPRINGTIME WINTER STORM THAT IS POISED TO
STRIKE THE NORTHLAND SUNDAY AND SUNDAY NIGHT. COMPARED TO WHAT I
SAW IN THE 12Z MODELS YESTERDAY...THE SNOWFALL ACROSS NE MINNESOTA
IN THE 00Z MODELS SNOWFALL SEEMS TO BE LOWER THAN YESTERDAY. IF
THE NEW 12Z MODELS REMAIN FAIRLY CONSISTENT AND AGREEABLE BETWEEN
EACH OTHER...THAN WE WILL PROBABLY ISSUE WINTER STORM WARNINGS AND
ADVISORIES FOR THIS NEXT ROUND OF SNOW.
&&
.PREV DISCUSSION... /ISSUED 711 AM CDT SAT APR 13 2013/
AVIATION.../12Z TAF ISSUANCE/
THE LARGE WINTER STORM THAT MOVED THROUGH OVER THE PAST FEW DAYS
WILL GRADUALLY PULL OUT OVER THE NEXT 24 HOURS. THE RESULT WILL BE
WIDELY VARYING CLOUD HEIGHTS AND VISIBILITIES AS THE LOW MOVES
EAST AND THE CLOUDS AND SNOW SHOWERS TRY TO BREAK UP. CONDITIONS
WILL VARY BETWEEN VFR AND MVFR AND LOCALLY IFR.
SHORT TERM...
CURRENT...VERTICALLY STACKED CIRCULATION OVER ERN LAKE SUPERIOR
IS MAINTAINING A MOIST CYCLONIC FLOW OVER CWA EARLY THIS MORNING.
ABUNDANCE OF CLOUDS WITH SOME WIND AND LIGHT PRECIP HAS KEPT
TEMPS ACROSS CWA FAIRLY UNIFORM. LOWEST READINGS ARE IN THE MN
ARROWHEAD WITH TEENS ...AND 20S ELSEWHERE.
TODAY...WIDESPREAD AREA OF LIGHT SNOW ACROSS MN ZONES WILL ADVECT
EASTWARD INTO WISC ZONES THROUGH REMAINDER OF MORNING. WILL LET WSW
EXPIRE IN BAYFIELD COUNTY AT 12Z AND EXTEND ASHLAND/IRON COUNTIES
TIL 15Z. ALTHOUGH CYCLONIC FLOW WILL PERSIST SFC/ALOFT TODAY...DEEP
LAYER RH IS EXPECTED TO GRADUALLY DIMINISH. LT SNOW/SNOW SHOWERS
WILL PERSIST THROUGH MID AFTN OVER MN ZONES..AND PERHAPS UNTIL LATE
AFN OVER WISC ZONES. MAX TEMPS REMAIN WELL BLO CLIMO WITH MID 30S
PREVAILING.
TONIGHT...PROGRESSIVE FLOW ALOFT WILL ALLOW MID LVL RIDGING TO PUSH
INTO CWA FROM THE SOUTHWEST OVERNIGHT. AN ELONGATED AREA OF LOW
PRESSURE AT THE SFC WILL STRETCH FROM CTRL SD TO ERN NEB BY 12Z
SUNDAY. CLOUDS WILL INCREASE OVER SWRN CWA WITH SNOW DEVELOPING
AROUND 09Z AS AN AREA OF WARM FRONTOGENESIS INCREASES.
TOMORROW...MDLS AGREE THAT A DUAL LOBE SFC PRESS PATTERN WILL
CONTINUE TO MOVE NORTHEAST. THE NRN LOW WILL MOVE TOWARDS THE ND/SD
BORDER BY 00Z WHILE THE SECONDARY LOW WILL MIGRATE TO SERN MN. AN
AREA OF STRONG 85H FRONTOGENESIS WILL BE RESPONSIBLE FOR AN AREA OF
MODERATE INTENSITY SNOWFALL MAKING ITS WAY ACROSS MOST OF MN ZONES
EXCEPT ERN ARROWHEAD. A GENERAL 3 TO 6 INCH SNOWFALL APPEARS
INCREASING LIKELY FROM THE BRAINERD LAKES REGION TO TWIN PORTS AND
POINTS NORTH AND WEST. A TRANSITION IN PTYPE SHOULD OCCUR IN THE SRN
THIRD OF THE CWA BY AFTN AS ICE PELLETS AND RAIN BEGIN TO DEVELOP.
WITH PROSPECT FOR ACCUMULATING SNOW TO CONTINUE BEYOND THIS PERIOD
WILL LET DAY SHIFT DECIDE IF AN ADVISORY OR WARNING WILL BE ISSUED
FOR SUNDAY/SUNDAY NIGHT EVENT.
PREV DISCUSSION... /ISSUED 332 AM CDT SAT APR 13 2013/
EXTENDED...SUNDAY NIGHT THROUGH SATURDAY...
THE STRONG LOW PRESSURE SYSTEM THAT WILL MOVE THROUGH LATE IN THE
WEEKEND WILL CONTINUE TO AFFECT THE NORTHLAND INTO SUNDAY NIGHT.
THERE WILL LIKELY STILL BE SOME ACCUMULATION INTO THE
NIGHT...ESPECIALLY ACROSS NE MN. A MIX IS EXPECTED FROM EC MN INTO
PORTIONS OF NW WI...WITH MAINLY RAIN ACROSS THE FAR SE. STRONG WINDS
WILL GRADUALLY SUBSIDE AS THE SURFACE LOW MOVES INTO NORTHERN
MN...BUT STRONG NW TO W WINDS WILL THEN DEVELOP ON THE BACKSIDE OF
THE LOW ON MONDAY...WITH WRAP AROUND SNOW SHOWERS CONTINUING.
ANOTHER STRONG SYSTEM WILL THEN AFFECT THE AREA TOWARD THE MIDDLE OF
NEXT WEEK...BUT THE MODELS HAVE BACKED OFF ON WIDESPREAD AND HEAVY
PRECIPITATION WITH THIS SYSTEM. STILL LOOKS LIKE IT COULD BRING SOME
ACCUMULATION...BUT THE GEM IS THE MODEL WITH THE HEAVIEST
PRECIPITATION. IN ALL...IT LOOKS LIKE GENERALLY COOLER THAN NORMAL
TEMPERATURES THROUGH THE EXTENDED TIME PERIOD. THE GFS DOES BRING A
SURFACE LOW ACROSS MN ON FRIDAY NIGHT AND SATURDAY...BUT THE ECMWF
HAS HIGH PRESSURE AT THE SAME TIME.
&&
.POINT TEMPS/POPS...
DLH 36 23 34 28 / 30 30 100 80
INL 37 16 38 28 / 30 0 90 90
BRD 38 25 36 27 / 30 90 100 70
HYR 38 20 38 30 / 40 50 100 80
ASX 37 19 37 31 / 60 10 100 100
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING
FOR MNZ010>012-018>021-026.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
MNZ025-033>036.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ037.
WI...WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ003-004.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
147-148.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
116 PM CDT SAT APR 13 2013
.UPDATE...
ISSUED AT 116 PM CDT SAT APR 13 2013
NO MAJOR CHANGES PLANNED FOR THE EARLY AFTERNOON UPDATE. CLOUD
COVER IS SLOW TO DISSIPATE ACROSS NORTHWEST AND WEST CENTRAL
MN...AFFECTING TEMPERATURE RECOVERY. HOWEVER...AFTERNOON HIGHS
STILL REASONABLE AND WILL NOT CHANGE AT THIS TIME.
UPDATE ISSUED AT 955 AM CDT SAT APR 13 2013
1430 UTC WATER VAPOR LOOP SHOWS AN UPPER LOW SPINNING ACROSS LAKE
SUPERIOR AND A MUCH STRONGER VORTICITY MAXIMUM DIGGING ACROSS THE
PACIFIC NORTHWEST. IN-BETWEEN...SHORT WAVE RIDGING ALONG THE
MT/ND BORDER IS EXPECTED TO SLIDE EASTWARD TODAY FOR RELATIVELY
TRANQUIL WEATHER CONDITIONS. SURFACE RIDGE AXIS FROM THE DEVILS
LAKE BASIN DOWN THE JAMES RIVER VALLEY IS ALSO EXPECTED TO MOVE
INTO NORTHWEST MN THIS AFTERNOON AND EVENING...ALLOWING LIGHT AND
VARIABLE WIND TO INCREASE FROM THE EAST ACROSS EASTERN ND THIS
AFTERNOON. THIS SHOULD HELP DISSIPATE ANY REMAINING PATCHY FOG
FROM OVERNIGHT. LATEST RAP SUGGESTS MID-LEVEL CLOUD COVER SHOULD
SLOWLY DISSIPATE THROUGH THE DAY...BUT WITH LATEST IR SATELLITE
SHOWING CONSIDERABLE CLOUDINESS ACROSS MUCH OF THE FORECAST
AREA...WILL INCREASE CLOUD COVER THROUGH MID-AFTERNOON. FOR THOSE
AREAS NOT CURRENTLY SUNNY...EXPECT AT LEAST FILTERED SUNSHINE
ALONG AND EAST OF THE VALLEY BY LATE THIS AFTERNOON. FOR THE FAR
WESTERN FORECAST AREA...LOWERED AFTERNOON HIGHS A FEW DEGREES TO
ACCOUNT FOR CURRENT TEMPERATURES ONLY IN THE TEENS AND OVERCAST
SKIES WHICH WILL LIMIT OVERALL RECOVERY.
WILL NOT MAKE ANY CHANGES FOR NOW TO TONIGHT/TOMORROWS STORM AND
ASSOCIATED HEADLINES AND RE-EVALUATE WITH THIS AFTERNOON/S
FORECAST.
UPDATE ISSUED AT 620 AM CDT SAT APR 13 2013
WE WILL ISSUE A WINTER STORM WARNING FOR THE ENTIRE FORECAST AREA
WITH THIS UPDATE. CONFIDENCE IS HIGH WITH A MAJOR WINTER STORM FROM
LATE TONIGHT THROUGH SUNDAY NIGHT. EXPECT FAIRLY WIDESPREAD SNOW
TOTALS RANGING FROM 6 TO 10 INCHES IN THE NORTHERN 2/3 OF THE
REGION WITH LOWER TOTALS IN THE FAR SOUTH WHERE SOME FREEZING
RAIN/SLEET IS POSSIBLE LATE TONIGHT AND SUNDAY MORNING. SOME AREAS
COULD LOCALLY REACH 1 FOOT MAINLY FROM THE DEVILS LAKE BASING INTO
NORTHEAST ND AND NW ND WHERE THE DEFORMATION SNOW BAND SETS UP.
EXPECT THE MOST SIGNIFICANT IMPACTS LATE TONIGHT IN THE FAR
SOUTH...AND SUNDAY INTO SUNDAY EVENING FURTHER NORTH. WINDS WILL
ALSO INCREASE AND GUST OVER 35 MPH AT TIMES IN THE VALLEY...PRODUCING
CONSIDERABLE BLOWING AND DRIFTING SNOW AND REDUCED VSBYS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 340 AM CDT SAT APR 13 2013
THE MAIN CHALLENGE WILL BE UPCOMING STORM FOR LATE SATURDAY NIGHT
THROUGH SUNDAY NIGHT. MODELS ARE COMING INTO GOOD AGREEMENT
OVERALL...WITH STILL A FEW DETAILS TO IRON OUT.
FOR TODAY...EXPECT SOME LINGERING SNOW SHOWERS/FLURRIES MAINLY IN
THE FAR EAST THIS MORNING. OTHERWISE...SOME CLEARING IS EXPECTED
BY AFTERNOON BUT TEMPS WILL REMAIN WELL BELOW NORMAL.
FOR TONIGHT...EXPECT INCREASING CLOUDS AND PRECIP SHOULD QUICKLY
DEVELOP IN THE SOUTH AROUND OR SHORTLY AFTER 06Z. A DYNAMIC STORM
SYSTEM WILL SPREAD A BAND OF WAA INDUCED SNOW WITH SOME FREEZING
RAIN/SLEET IN THE FAR SOUTH.
ON SUNDAY...A WIDESPREAD BAND OF SNOW...HEAVY AT TIMES...WILL
DEVELOP/SPREAD SLOWLY NORTH AND EAST. THERE COULD STILL BE SOME
RAIN MIXING IN THE FAR SOUTH AND EAST. VERTICAL MOTION FIELDS ARE
STRONG...WITH DEEP LAYERED OMEGA THROUGH 400 MB WITH STRONG FGEN
IN THE MID LEVELS. HIGH MOISTURE VALUES WITH PWATS AROUND 0.75
WILL ALSO ADVECT INTO THE AREA AS 850MB WINDS INCREASE TO AROUND
50 KT. IT WILL ALSO BECOME WINDY IN THE NORTH...AND EXPECT BLOWING
SNOW AND REDUCED VSBYS AS WELL. THE MAIN QUESTION WILL BE HOW MUCH
SNOW ACCUMULATES GIVEN IT IS MID APRIL. THERE SHOULD BE HIGH
ENOUGH QPF RATES TO PRODUCE SNOW RATES OF AN INCH...MAYBE 2...PER
HOUR IN SOME AREAS BY SUNDAY AFTERNOON. TEMPS SHOULD HOVER NEAR
FREEZING FOR MOST AREAS...WITH SOME MELTING POSSIBLE ON PAVEMENT
AND HIGHER ACCUMS ON GRASSY AND SNOW SURFACES. THERE COULD BE
AREAS THAT GET UP TO 6 INCHES ON SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM CDT SAT APR 13 2013
FOR SUNDAY NIGHT INTO EARLY MONDAY...SFC LOW SHOULD TRACK INTO THE
E/NE FORECAST AREAS WITH WRAPAROUND DEFORMATION SNOW BAND TO THE
NW. THE HEAVIEST SNOW SHOULD FALL FROM THE DVL BASIN INTO NE
ND...WHERE ADDITIONAL AMOUNTS OF UP TO 4 INCHES ARE POSSIBLE.
STORM TOTAL SNOW AMOUNTS BY MONDAY MORNING COULD REACH UP TO A
FOOT IN SOME AREAS...WITH FAVORED LOCATIONS FROM CENTRAL ND INTO
THE DVL BASIN TO AROUND GRAND FORKS TO HALLOCK. FOR NOW WE WILL
CONTINUE WITH THE WINTER STORM WATCH FOR THE ENTIRE REGION SINCE
THE DRY SLOT COULD REDUCE QPF AMOUNTS IN THE SOUTH A BIT. THERE IS
STILL TIME TO IRON OUT DETAILS...WITH THE LARGEST IMPACTS LATE SAT
NIGHT AND SUNDAY. A MAJOR WINTER STORM APPEARS IMMINENT THOUGH FOR
MOST AREAS AT THIS TIME.
QUIETER WEATHER IS ON TAP FOR TUESDAY AS THE UPPER LOW CONTINUES TO
PUSH AWAY. SOUTHWEST FLOW ALOFT WILL OVERSPREAD THE PLAINS AS
SHORTWAVE ENERGY DIVES INTO THE DESERT SOUTHWEST...CARVING OUT A
BROAD LONGWAVE TROUGH OVER THE WESTERN US. UNCERTAINTY STILL REMAINS
HOW THIS SYSTEM WILL EVOLVE ACROSS THE PLAINS. 00Z MODELS GENERALLY
TAKE THE SFC LOW UP INTO THE SOUTHERN GREAT LAKES BY
THURSDAY...KEEPING THE MORE SIGNIFICANT PRECIP TO THE SOUTH AND
EAST. WILL KEEP SOME POPS WITH FOR MID-WEEK GIVEN LOW CONFIDENCE
THOUGH. OTHERWISE...TEMPS WILL CONTINUE TO REMAIN WELL BELOW NORMAL
WITH 850 MB BAROCLINIC DISPLACED WELL SOUTH. EXPECT HIGHS MAINLY IN
THE 30S WITH LOWS IN THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 116 PM CDT SAT APR 13 2013
A BIT OF LINGERING STRATUS OVER KDVL SHOULD DISSIPATE IN THE NEXT
FEW HOURS...LEAVING VFR CONDITIONS EVERYWHERE FOR THE REST OF THIS
AFTERNOON AND INTO THE EVENING. CIGS AND VIS WILL BEGIN TO
DETERIORATE AFTER 06Z TONIGHT AS SNOW BEGINS TO MOVE IN FROM THE
SOUTHWEST. KFAR AND THEN KDVL AND KGFK SHOULD GO DOWN TO MVFR
CEILINGS AND VIS AROUND 1SM OR LOWER WITH EASTERLY WINDS PICKING UP
INTO THE 20 TO 25 KT RANGE WITH HIGHER GUSTS. VIS OF 1/2 TO 1/4SM
ARE NOT OUT OF THE QUESTION TOWARDS THE END OF THE PERIOD UNDER THE
HEAVIEST SNOW BANDS...BUT STILL SOME UNCERTAINTY AS TO EXACTLY WHERE
AND WHEN SO WILL JUST KEEP VIS AROUND 1SM FOR NOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WARNING FROM 4 AM SUNDAY TO 7 AM CDT MONDAY FOR
NDZ028>030-038-039-049-052-053.
WINTER STORM WARNING FROM 10 AM SUNDAY TO 7 AM CDT MONDAY FOR
NDZ006>008-014>016-024-026-027-054.
MN...WINTER STORM WARNING FROM 4 AM SUNDAY TO 7 AM CDT MONDAY FOR
MNZ002-003-022>024-027>032-040.
WINTER STORM WARNING FROM 10 AM SUNDAY TO 7 AM CDT MONDAY FOR
MNZ001-004>009-013>017.
&&
$$
UPDATE...ROGERS
SHORT TERM...DK
LONG TERM...MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
955 AM CDT SAT APR 13 2013
.UPDATE...
ISSUED AT 955 AM CDT SAT APR 13 2013
1430 UTC WATER VAPOR LOOP SHOWS AN UPPER LOW SPINNING ACROSS LAKE
SUPERIOR AND A MUCH STRONGER VORTICITY MAXIMUM DIGGING ACROSS THE
PACIFIC NORTHWEST. IN-BETWEEN...SHORT WAVE RIDGING ALONG THE
MT/ND BORDER IS EXPECTED TO SLIDE EASTWARD TODAY FOR RELATIVELY
TRANQUIL WEATHER CONDITIONS. SURFACE RIDGE AXIS FROM THE DEVILS
LAKE BASIN DOWN THE JAMES RIVER VALLEY IS ALSO EXPECTED TO MOVE
INTO NORTHWEST MN THIS AFTERNOON AND EVENING...ALLOWING LIGHT AND
VARIABLE WIND TO INCREASE FROM THE EAST ACROSS EASTERN ND THIS
AFTERNOON. THIS SHOULD HELP DISSIPATE ANY REMAINING PATCHY FOG
FROM OVERNIGHT. LATEST RAP SUGGESTS MID-LEVEL CLOUD COVER SHOULD
SLOWLY DISSIPATE THROUGH THE DAY...BUT WITH LATEST IR SATELLITE
SHOWING CONSIDERABLE CLOUDINESS ACROSS MUCH OF THE FORECAST
AREA...WILL INCREASE CLOUD COVER THROUGH MID-AFTERNOON. FOR THOSE
AREAS NOT CURRENTLY SUNNY...EXPECT AT LEAST FILTERED SUNSHINE
ALONG AND EAST OF THE VALLEY BY LATE THIS AFTERNOON. FOR THE FAR
WESTERN FORECAST AREA...LOWERED AFTERNOON HIGHS A FEW DEGREES TO
ACCOUNT FOR CURRENT TEMPERATURES ONLY IN THE TEENS AND OVERCAST
SKIES WHICH WILL LIMIT OVERALL RECOVERY.
WILL NOT MAKE ANY CHANGES FOR NOW TO TONIGHT/TOMORROWS STORM AND
ASSOCIATED HEADLINES AND RE-EVALUATE WITH THIS AFTERNOON/S
FORECAST.
UPDATE ISSUED AT 620 AM CDT SAT APR 13 2013
WE WILL ISSUE A WINTER STORM WARNING FOR THE ENTIRE FORECAST AREA
WITH THIS UPDATE. CONFIDENCE IS HIGH WITH A MAJOR WINTER STORM FROM
LATE TONIGHT THROUGH SUNDAY NIGHT. EXPECT FAIRLY WIDESPREAD SNOW
TOTALS RANGING FROM 6 TO 10 INCHES IN THE NORTHERN 2/3 OF THE
REGION WITH LOWER TOTALS IN THE FAR SOUTH WHERE SOME FREEZING
RAIN/SLEET IS POSSIBLE LATE TONIGHT AND SUNDAY MORNING. SOME AREAS
COULD LOCALLY REACH 1 FOOT MAINLY FROM THE DEVILS LAKE BASING INTO
NORTHEAST ND AND NW ND WHERE THE DEFORMATION SNOW BAND SETS UP.
EXPECT THE MOST SIGNIFICANT IMPACTS LATE TONIGHT IN THE FAR
SOUTH...AND SUNDAY INTO SUNDAY EVENING FURTHER NORTH. WINDS WILL
ALSO INCREASE AND GUST OVER 35 MPH AT TIMES IN THE VALLEY...PRODUCING
CONSIDERABLE BLOWING AND DRIFTING SNOW AND REDUCED VSBYS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 340 AM CDT SAT APR 13 2013
THE MAIN CHALLENGE WILL BE UPCOMING STORM FOR LATE SATURDAY NIGHT
THROUGH SUNDAY NIGHT. MODELS ARE COMING INTO GOOD AGREEMENT
OVERALL...WITH STILL A FEW DETAILS TO IRON OUT.
FOR TODAY...EXPECT SOME LINGERING SNOW SHOWERS/FLURRIES MAINLY IN
THE FAR EAST THIS MORNING. OTHERWISE...SOME CLEARING IS EXPECTED
BY AFTERNOON BUT TEMPS WILL REMAIN WELL BELOW NORMAL.
FOR TONIGHT...EXPECT INCREASING CLOUDS AND PRECIP SHOULD QUICKLY
DEVELOP IN THE SOUTH AROUND OR SHORTLY AFTER 06Z. A DYNAMIC STORM
SYSTEM WILL SPREAD A BAND OF WAA INDUCED SNOW WITH SOME FREEZING
RAIN/SLEET IN THE FAR SOUTH.
ON SUNDAY...A WIDESPREAD BAND OF SNOW...HEAVY AT TIMES...WILL
DEVELOP/SPREAD SLOWLY NORTH AND EAST. THERE COULD STILL BE SOME
RAIN MIXING IN THE FAR SOUTH AND EAST. VERTICAL MOTION FIELDS ARE
STRONG...WITH DEEP LAYERED OMEGA THROUGH 400 MB WITH STRONG FGEN
IN THE MID LEVELS. HIGH MOISTURE VALUES WITH PWATS AROUND 0.75
WILL ALSO ADVECT INTO THE AREA AS 850MB WINDS INCREASE TO AROUND
50 KT. IT WILL ALSO BECOME WINDY IN THE NORTH...AND EXPECT BLOWING
SNOW AND REDUCED VSBYS AS WELL. THE MAIN QUESTION WILL BE HOW MUCH
SNOW ACCUMULATES GIVEN IT IS MID APRIL. THERE SHOULD BE HIGH
ENOUGH QPF RATES TO PRODUCE SNOW RATES OF AN INCH...MAYBE 2...PER
HOUR IN SOME AREAS BY SUNDAY AFTERNOON. TEMPS SHOULD HOVER NEAR
FREEZING FOR MOST AREAS...WITH SOME MELTING POSSIBLE ON PAVEMENT
AND HIGHER ACCUMS ON GRASSY AND SNOW SURFACES. THERE COULD BE
AREAS THAT GET UP TO 6 INCHES ON SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM CDT SAT APR 13 2013
FOR SUNDAY NIGHT INTO EARLY MONDAY...SFC LOW SHOULD TRACK INTO THE
E/NE FORECAST AREAS WITH WRAPAROUND DEFORMATION SNOW BAND TO THE
NW. THE HEAVIEST SNOW SHOULD FALL FROM THE DVL BASIN INTO NE
ND...WHERE ADDITIONAL AMOUNTS OF UP TO 4 INCHES ARE POSSIBLE.
STORM TOTAL SNOW AMOUNTS BY MONDAY MORNING COULD REACH UP TO A
FOOT IN SOME AREAS...WITH FAVORED LOCATIONS FROM CENTRAL ND INTO
THE DVL BASIN TO AROUND GRAND FORKS TO HALLOCK. FOR NOW WE WILL
CONTINUE WITH THE WINTER STORM WATCH FOR THE ENTIRE REGION SINCE
THE DRY SLOT COULD REDUCE QPF AMOUNTS IN THE SOUTH A BIT. THERE IS
STILL TIME TO IRON OUT DETAILS...WITH THE LARGEST IMPACTS LATE SAT
NIGHT AND SUNDAY. A MAJOR WINTER STORM APPEARS IMMINENT THOUGH FOR
MOST AREAS AT THIS TIME.
QUIETER WEATHER IS ON TAP FOR TUESDAY AS THE UPPER LOW CONTINUES TO
PUSH AWAY. SOUTHWEST FLOW ALOFT WILL OVERSPREAD THE PLAINS AS
SHORTWAVE ENERGY DIVES INTO THE DESERT SOUTHWEST...CARVING OUT A
BROAD LONGWAVE TROUGH OVER THE WESTERN US. UNCERTAINTY STILL REMAINS
HOW THIS SYSTEM WILL EVOLVE ACROSS THE PLAINS. 00Z MODELS GENERALLY
TAKE THE SFC LOW UP INTO THE SOUTHERN GREAT LAKES BY
THURSDAY...KEEPING THE MORE SIGNIFICANT PRECIP TO THE SOUTH AND
EAST. WILL KEEP SOME POPS WITH FOR MID-WEEK GIVEN LOW CONFIDENCE
THOUGH. OTHERWISE...TEMPS WILL CONTINUE TO REMAIN WELL BELOW NORMAL
WITH 850 MB BAROCLINIC DISPLACED WELL SOUTH. EXPECT HIGHS MAINLY IN
THE 30S WITH LOWS IN THE 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 955 AM CDT SAT APR 13 2013
PATCHY LOW CIGS AND VIS ALONG THE WESTERN FORECAST AREA WILL
CONTINUE TO IMPROVE FOR THE REST OF THE MORNING. FURTHER
EAST...CEILINGS WILL REMAIN MVFR TO LOW VFR WITH SOME BREAKS
PROVIDING A FEW CLEAR SPOTS AT TIMES. CONDITIONS SHOULD BE VFR AT
ALL TAF SITES BY THIS AFTERNOON AND EARLY EVENING...BUT SHOULD BEGIN
TO DETERIORATE AFTER 06Z TONIGHT AS CLOUDS AND PRECIP BEGIN TO MOVE
INTO THE REGION WITH THE NEXT STORM SYSTEM.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WARNING FROM 4 AM SUNDAY TO 7 AM CDT MONDAY FOR
NDZ028>030-038-039-049-052-053.
WINTER STORM WARNING FROM 10 AM SUNDAY TO 7 AM CDT MONDAY FOR
NDZ006>008-014>016-024-026-027-054.
MN...WINTER STORM WARNING FROM 4 AM SUNDAY TO 7 AM CDT MONDAY FOR
MNZ002-003-022>024-027>032-040.
WINTER STORM WARNING FROM 10 AM SUNDAY TO 7 AM CDT MONDAY FOR
MNZ001-004>009-013>017.
&&
$$
UPDATE...ROGERS
SHORT TERM...DK
LONG TERM...MAKOWSKI
AVIATION...DK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
138 PM EDT SAT APR 13 2013
.SYNOPSIS...
LOW PRESSURE OVER THE EASTERN GREAT LAKES WILL SLOWLY LIFT OUT
TODAY. HIGH PRESSURE FROM THE PLAINS STATES WILL MOVE TO THE OHIO
VALLEY TONIGHT AND THEN MOVE TO THE EAST COAST ON SUNDAY.A COLD
FRONT FROM THE WEST WILL APPROACH THE AREA LATE MONDAY OR TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HRRR AND RUC CONTINUE TO DEVELOP SCT SHRA ACROSS THE CWA BY MIDDAY
AND THIS SEEMS REASONABLE GIVEN THE UPPER TROFFING AND GOOD VORT MAX
THAT WILL ROTATE ACROSS THE AREA. HAVE DECIDED TO ADJUST WX
PARAMETER SO THAT RA/SN MIX WILL GO TO JUST RA FOR ANY TEMPS ABOVE
40 DEGREES AS TEMPS ALOFT JUST NOT COLD ENOUGH FOR SNOW IF BOUNDARY
GETS TOO WARM. WILL CONTINUE ALLOW FOR SOME HOLES IN THE CLOUDS TO
BEGIN TO OCCUR IN THE MID AND LATTER AFTERNOON HOURS...ESPECIALLY
FOR THE SW HALF OF THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL BUILD IN TONIGHT. AREAS THAT CAN CLEAR WILL SEE
CHILLY TEMPERATURES...DOWN AROUND FREEZING. CLOUDS COULD HANG ON
ACROSS EXTREME NE OH/NW PA MUCH OF THE NIGHT...AND HIGH CLOUDS
COULD ARRIVE BEFORE DAYBREAK SO THE FORECAST WILL NOT BE AS COLD
AS IT COULD BE.
LOTS OF RIDGING AT THE SURFACE AND ALOFT ON SUNDAY ALTHOUGH WARM
ADVECTION IS STRONG AND PATCHES OF MID AND HIGH CLOUDS ARE LIKELY.
IT MAY NOT BE SUNNY BUT IT SHOULD TURN OUT AT LEAST PARTLY
SUNNY. TEMPERATURES SHOULD REBOUND TO NEAR NORMAL FROM THE MID 50S
TO AROUND 60.
WILL BE WATCHING THE APPROACH OF THE NEXT COLD FRONT EARLY IN THE
WEEK. THE MODELS CONTINUE TO SUGGEST VARYING ARRIVAL TIMES. THE GFS
REMAINS THE FASTEST MODEL AND SEEMS TO HAVE TOO MUCH MOMENTUM ON
MONDAY ALTHOUGH THE FRONT COULD GET CLOSE TO TOLEDO BY THE END OF
THE DAY. A COMPROMISE OF THE MODELS WOULD SLIDE THE FRONT INTO THE
FORECAST AREA ON TUESDAY BUT LITTLE CONFIDENCE IN THE FORECAST AT
THIS TIME GIVEN THE VARIOUS SOLUTIONS. WILL SLOWLY INCREASE THE
POP MONDAY INTO TUESDAY AND MENTION THUNDER ON TUESDAY. WE SHOULD
GET A WARM DAY ON MONDAY. TUESDAY IS UP FOR GRABS DEPENDING ON THE
SPEED OF THE FRONT AND HOW MUCH CLOUDS AND SHOWERS DEVELOP. THE
FORECAST HIGHS ON TUESDAY WILL BE SOMEWHAT LOWER THAN MONDAY AS A
COMPROMISE BUT THE POTENTIAL TEMPERATURE RANGE IS WIDE ON TUESDAY
DEPENDING ON THE SPEED OF THE FRONTAL PASSAGE.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
LOOKING AT A FAMILIAR WX PATTERN FROM MID WEEK ON AS ANOTHER
QUASI-STATIONARY FRONT MOVES INTO OHIO. THE EXACT LOCATION OF THE
FRONT IS DIFFICULT TO DETERMINE AT THIS TIME...AND ITS PLACEMENT
WILL MAKE A SIGNIFICANT DIFFERENCE ON TEMPERATURES AND WEATHER. FOR
NOW WILL CONTINUE THE HIGH CHANCE POPS. BY THURSDAY MOST MODELS
AGREE THAT THE WARM FRONT WILL LIFT NORTH OF THE LAKE AS A STRONGER
LOW MOVES IN FROM THE PLAINS. THE INCREASE IN THE LL JET WILL
SUPPORT WARMER TEMPERATURES DESPITE EXPECTED CLOUD COVER. THIS WILL
LIKELY BE THE BEST CHANCE FOR STRONG CONVECTION. A COLD FRONT WILL
FOLLOW IN THE WAKE OF THE EXITING LOW ON FRIDAY WITH TEMPERATURES
FALLING DURING THE DAY. BY NEXT WEEKEND TEMPERATURES WILL COOL BACK
INTO THE 40S.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AN UPPER LOW OVER EASTERN CANADA WILL MOVE SLOWLY NORTHEAST
TONIGHT. IN THE MEANTIME WEAK IMPULSES IMPEDED IN THIS FLOW WILL
CAUSE SCATTERED LIGHT SHOWERS THROUGH EARLY TONIGHT. SOME OF THE
SHOWERS WILL HAVE MVFR CEILINGS AND VISIBILITIES. HIGH PRESSURE
AT THE SURFACE WILL BE BUILDING IN FROM THE SOUTHWEST TONIGHT AND
THAT SHOULD DECREASE THE CLOUDS. THE HIGH WILL MOVE EAST ON
SUNDAY. A WARM FRONT WILL MOVE ACROSS THE AREA ON SUNDAY CAUSING
MAINLY MID CLOUD AND LIGHT SHOWERS SPRINKLES.
.OUTLOOK...NON VFR AT TIMES LATE MONDAY INTO THURSDAY.
&&
.MARINE...
THE SOUTHWESTERLY FLOW WILL INCREASE TODAY AS AN AREA OF LOW
PRESSURE MOVES OFF TO OUR NORTH AND AN AREA OF HIGH PRESSURE BUILDS
IN FROM THE SOUTHWEST. THE GRADIENT WILL SUPPORT GUSTS OVER 25 KT
THROUGH THE OVERNIGHT WHICH WILL JUSTIFY A SMALL CRAFT ADVISORY. THE
HIGH WILL DOMINATE ON SUNDAY ALLOWING HEADLINES TO FALL OFF. THINGS
TURN AROUND NEXT WEEK AS AN ACTIVE WEATHER PATTERN SETS UP. RAIN AND
PERIODIC SMALL CRAFT WINDS ARE LIKELY FROM TUESDAY ON.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT SUNDAY FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
LEZ142>145.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KOSARIK
SHORT TERM...KOSARIK
LONG TERM...JAMISON
AVIATION...KIELTYKA
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
915 AM EDT SAT APR 13 2013
.SYNOPSIS...
LOW PRESSURE OVER THE EASTERN GREAT LAKES WILL SLOWLY LIFT OUT
TODAY. HIGH PRESSURE FROM THE PLAINS STATES WILL MOVE TO THE OHIO
VALLEY TONIGHT AND THEN MOVE TO THE EAST COAST ON SUNDAY.A COLD
FRONT FROM THE WEST WILL APPROACH THE AREA LATE MONDAY OR TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HRRR AND RUC CONTINUE TO DEVELOP SCT SHRA ACROSS THE CWA BY MIDDAY
AND THIS SEEMS REASONABLE GIVEN THE UPPER TROFFING AND GOOD VORT MAX
THAT WILL ROTATE ACROSS THE AREA. HAVE DECIDED TO ADJUST WX
PARAMETER SO THAT RA/SN MIX WILL GO TO JUST RA FOR ANY TEMPS ABOVE
40 DEGREES AS TEMPS ALOFT JUST NOT COLD ENOUGH FOR SNOW IF BOUNDARY
GETS TOO WARM. WILL CONTINUE ALLOW FOR SOME HOLES IN THE CLOUDS TO
BEGIN TO OCCUR IN THE MID AND LATTER AFTERNOON HOURS...ESPECIALLY
FOR THE SW HALF OF THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL BUILD IN TONIGHT. AREAS THAT CAN CLEAR WILL SEE
CHILLY TEMPERATURES...DOWN AROUND FREEZING. CLOUDS COULD HANG ON
ACROSS EXTREME NE OH/NW PA MUCH OF THE NIGHT...AND HIGH CLOUDS
COULD ARRIVE BEFORE DAYBREAK SO THE FORECAST WILL NOT BE AS COLD
AS IT COULD BE.
LOTS OF RIDGING AT THE SURFACE AND ALOFT ON SUNDAY ALTHOUGH WARM
ADVECTION IS STRONG AND PATCHES OF MID AND HIGH CLOUDS ARE LIKELY.
IT MAY NOT BE SUNNY BUT IT SHOULD TURN OUT AT LEAST PARTLY
SUNNY. TEMPERATURES SHOULD REBOUND TO NEAR NORMAL FROM THE MID 50S
TO AROUND 60.
WILL BE WATCHING THE APPROACH OF THE NEXT COLD FRONT EARLY IN THE
WEEK. THE MODELS CONTINUE TO SUGGEST VARYING ARRIVAL TIMES. THE GFS
REMAINS THE FASTEST MODEL AND SEEMS TO HAVE TOO MUCH MOMENTUM ON
MONDAY ALTHOUGH THE FRONT COULD GET CLOSE TO TOLEDO BY THE END OF
THE DAY. A COMPROMISE OF THE MODELS WOULD SLIDE THE FRONT INTO THE
FORECAST AREA ON TUESDAY BUT LITTLE CONFIDENCE IN THE FORECAST AT
THIS TIME GIVEN THE VARIOUS SOLUTIONS. WILL SLOWLY INCREASE THE
POP MONDAY INTO TUESDAY AND MENTION THUNDER ON TUESDAY. WE SHOULD
GET A WARM DAY ON MONDAY. TUESDAY IS UP FOR GRABS DEPENDING ON THE
SPEED OF THE FRONT AND HOW MUCH CLOUDS AND SHOWERS DEVELOP. THE
FORECAST HIGHS ON TUESDAY WILL BE SOMEWHAT LOWER THAN MONDAY AS A
COMPROMISE BUT THE POTENTIAL TEMPERATURE RANGE IS WIDE ON TUESDAY
DEPENDING ON THE SPEED OF THE FRONTAL PASSAGE.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
LOOKING AT A FAMILIAR WX PATTERN FROM MID WEEK ON AS ANOTHER
QUASI-STATIONARY FRONT MOVES INTO OHIO. THE EXACT LOCATION OF THE
FRONT IS DIFFICULT TO DETERMINE AT THIS TIME...AND ITS PLACEMENT
WILL MAKE A SIGNIFICANT DIFFERENCE ON TEMPERATURES AND WEATHER. FOR
NOW WILL CONTINUE THE HIGH CHANCE POPS. BY THURSDAY MOST MODELS
AGREE THAT THE WARM FRONT WILL LIFT NORTH OF THE LAKE AS A STRONGER
LOW MOVES IN FROM THE PLAINS. THE INCREASE IN THE LL JET WILL
SUPPORT WARMER TEMPERATURES DESPITE EXPECTED CLOUD COVER. THIS WILL
LIKELY BE THE BEST CHANCE FOR STRONG CONVECTION. A COLD FRONT WILL
FOLLOW IN THE WAKE OF THE EXITING LOW ON FRIDAY WITH TEMPERATURES
FALLING DURING THE DAY. BY NEXT WEEKEND TEMPERATURES WILL COOL BACK
INTO THE 40S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
WITH UPPER LOW ALOFT WILL SEE MOSTLY CLOUDY CONDITIONS WITH SPOTTY
RAIN SHOWER THIS AFTERNOON. ANY SHOWER ACTIVITY WILL BE BRIEF WITH
LITTLE RAINFALL OR REDUCED VISIBILITY. THE WINDS WILL PICK UP TO
15G25KT FOR THE BULK OF THE DAY AS AN AREA OF HIGH PRESSURE BUILDS
IN FROM THE SOUTHWEST AND PINCHES THE PRESSURE GRADIENT. WINDS WILL
SETTLE DOWN OVERNIGHT AS THE HIGH SLIDES OVER THE OHIO VALLEY.
.OUTLOOK...NON VFR DEVELOPING TUESDAY AND CONTINUING INTO
WEDNESDAY.
&&
.MARINE...
THE SOUTHWESTERLY FLOW WILL INCREASE TODAY AS AN AREA OF LOW
PRESSURE MOVES OFF TO OUR NORTH AND AN AREA OF HIGH PRESSURE BUILDS
IN FROM THE SOUTHWEST. THE GRADIENT WILL SUPPORT GUSTS OVER 25 KT
THROUGH THE OVERNIGHT WHICH WILL JUSTIFY A SMALL CRAFT ADVISORY. THE
HIGH WILL DOMINATE ON SUNDAY ALLOWING HEADLINES TO FALL OFF. THINGS
TURN AROUND NEXT WEEK AS AN ACTIVE WEATHER PATTERN SETS UP. RAIN AND
PERIODIC SMALL CRAFT WINDS ARE LIKELY FROM TUESDAY ON.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT SUNDAY FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
LEZ142>145.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KOSARIK/ADAMS
SHORT TERM...KOSARIK
LONG TERM...JAMISON
AVIATION...JAMISON
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
401 PM CDT SAT APR 13 2013
.SHORT-TERM (TONIGHT THROUGH SUNDAY NIGHT)...DESPITE A POTENT UPPER
LEVEL LOW CURRENTLY MVG ACROSS W TX WITH ENERGY ALOFT EXPECTED TO MV
ACROSS S TX TONIGHT...CONFIDENCE IS LOW THAT THE CWA WILL SEE ANY
BENIFICIAL RAIN. THE NAM AND RUC13 SHOW VERY LIGHT PRECIP ACROSS THE
NE CWA AND OVER THE WATERS BY EARLY SUNDAY MORNING. MODELS PROG THE
DEEPER MOISTURE TO BE ALONG THE RIO GRANDE AND EXTREME ERN CWA...BUT
MOISTURE IS VERY LIMITED. CIN VALUES ARE PROGD TO BE VERY HIGH ALONG
WITH LOW CAPE VALUES. MOS GUIDANCE POPS ARE ALL LESS THAN 20 PERCENT
WITH SOME LOCATIONS IN THE SINGLE DIGITS. ALL THE MODELS SHOW SOME
PRECIP EITHER N...S...E OR W OF THE CWA TONIGHT...AND WITH THE UPPER
SYSTEM PROGD TO MOVE ACROSS THE REGION TONIGHT...DID NOT WANT TO
COMPLETELY REMOVE POPS OR MENTION OF PRECIP. LOWERED 20 POPS TO 10
ACROSS THE LAND AREAS AND REMOVED TSRA`S FOR MOST OF THE AREA EXCEPT
THE FAR W WHERE STORMS OFF THE SIERRA MADRE COULD MOVE FAR ENOUGH E
TO REACH THE WRN CWA. RAIN CHCS DECREASE FROM W TO E THROUGH SUNDAY
MORNING AS THE UPPER LOW TRACKS E. PRESSURE GRADIENT ACROSS S TX
WILL RELAX THRU SUNDAY AS THE LOW PRESSURE SYSTEM EXITS THE REGION.
AIRMASS ABV THE SFC WILL BE DRIER ON SUNDAY LEADING TO WARMER TEMPS.
FAIRLY LIGHT WINDS...EXCEPT STRONGER ALONG THE RIO GRANDE...AND A
SHALLOW MOIST LAYER AT THE SFC COULD LEAD TO FOG SUNDAY NIGHT ACROSS
THE EASTERN CWA. FCST SOUNDINGS LOOK CONDUCIVE FOR RADIATIONAL FOG
DVLPMNT...POSSIBLY DENSE. SEA FOG COULD ALSO ADVECT INLAND SUNDAY
NIGHT DUE TO HIGHER DEWPOINTS OVER RELATIVELY COOLER SST.
&&
.MARINE...WEAK TO MODERATE EASTERLY FLOW WILL RELAX OVERNIGHT AND
VEER TO THE SE IN RESPONSE TO A LOW PRESSURE SYSTEM MOVE ACROSS THE
REGION AND EXITING TO THE E. ONSHORE FLOW WILL STRENGTHEN SLIGHTLY
SUNDAY NIGHT IN RESPONSE TO ANOTHER LOW PRESSURE SYSTEM DIGGING SWD
ALONG THE WEST COAST. PATCHY SEA FOG WILL BE POSSIBLE SUNDAY NIGHT
DUE TO DEWPOINTS IN THE UPPER 60S TO NEAR 70 MOVING ACROSS
RELATIVELY COOLER SST.
&&
.LONG TERM (MONDAY THROUGH SATURDAY NIGHT)...START OF PERIOD BEGINS
WITH ONSHORE FLOW AT THE SURFACE AND MOSTLY ZONAL FLOW ALOFT. MODELS
DEVELOP A DEEP UPPER LEVEL TROUGH/DISTURBANCE OVER THE ROCKIES THAT
WILL MOVE ACROSS THE CENTRAL CONUS AND REGION WEDNESDAY AND
THURSDAY. AHEAD OF THIS DISTURBANCE AND ASSOCIATED COLD FRONT EXPECT
ONSHORE FLOW TO INCREASE...AND SCEC TO SCA CONDITION TO DEVELOP
TUESDAY AFTERNOON THROUGH THURSDAY. PWAT VALUES INCREASE AHEAD OF
APPROACHING DISTURBANCE/SURFACE COLD FRONT TO 1.3 UP TO 1.5.
ANTICIPATE ISOLATED TO SHOWERS AND TSTMS AHEAD COLD FRONT ON
WEDNESDAY NIGHT/THURSDAY MORNING. TIMING DIFFERENCES WITH FROPA
STILL EXIST...WITH THE GFS A LITTLE SLOWER THAN THE ECMWF. EVEN
SO...EXPECT FRONT TO BE MOVING OFFSHORE AOA 18Z THURSDAY...AND
TEMPERATURES TO FALL THROUGH THE AFTERNOON. BEHIND THE FRONT WILL SEE
STRONG WINDS...ESPECIALLY OFFSHORE...AND SCA WILL DEVELOP ACROSS THE
GULF WATERS THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 65 85 69 84 70 / 10 10 10 10 10
VICTORIA 59 83 67 84 69 / 10 10 10 10 10
LAREDO 67 94 71 98 73 / 10 0 10 10 10
ALICE 64 88 68 90 69 / 10 10 10 10 10
ROCKPORT 66 78 69 76 69 / 10 10 10 10 10
COTULLA 62 91 67 96 69 / 10 0 10 10 10
KINGSVILLE 65 88 69 87 70 / 10 10 10 10 10
NAVY CORPUS 68 78 70 77 71 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TE/81...SHORT TERM
LK/84...LONG TERM
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1217 PM CDT SAT APR 13 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...LOW LEVEL STRATOCU DEVELOPING ACROSS NORTHERN MEXICO
AND DEEP SOUTH TEXAS AND THIS TREND WILL CONTINUE FOR THE NEXT 24
HOURS. CIG HEIGHTS ARE MAINLY VFR ACROSS THE AREA WITH
INTERMITTENT MVFR ACROSS NORTHERN MEXICO. BASED ON POINT SOUNDINGS
AND MIXING...CIGS WILL STAY VFR THROUGH THE EARLY EVENING. THIS
CLOUD DECK WILL LOWER INTO THE MVFR RANGE LATER THIS EVENING INTO
SUNDAY MORNING AS TEMPERATURES COOL. THERE IS AN OUTSIDE SHOT FOR
SHOWERS OVERNIGHT AS A MID LEVEL DISTURBANCE CROSS OVER THE AREA
BUT CONFIDENCE IS TOO LOW TO PLACE IN TAFS. WINDS WILL CONTINUE TO
BE GUSTY THIS AFTERNOON WITH SPEEDS DECREASING AFTER SUNSET.
&&
.PREV DISCUSSION... /ISSUED 623 AM CDT SAT APR 13 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE
MOSTLY MID TO HIGH LEVEL CLOUDS ACROSS THE CWA THIS MORNING.
CEILINGS WERE NEAR 300FT AT KHBV TO NEAR 2100FT AT KAPY. MVFR
CONDITIONS ARE A LOW PROBABILITY EARLY THIS MORNING WITH VFR
AFTER 15Z AS MIXING INCREASES. MVFR CEILINGS WILL LIKELY RETURN TONIGHT AS
LOW LEVEL MOISTURE INCREASES AHEAD OF A 500MB SHORTWAVE TROUGH
APPROACHING FROM THE WEST. ISOLATED SHOWERS MAY DEVELOP ACROSS THE
RIO GRANDE VALLEY TONIGHT WITH PATCHY FOG.
PREV DISCUSSION... /ISSUED 403 AM CDT SAT APR 13 2013/
SHORT TERM /TODAY THROUGH SUNDAY/...500MB LOW/TROUGH ACROSS
NORTHWEST MEXICO THIS MORNING WILL MOVE EASTWARD ACROSS NORTHERN
MEXICO THIS AFTERNOON AND EASTWARD ACROSS EAST TEXAS SUNDAY. AN
UPPER LEVEL JET ACROSS NORTHERN MEXICO WILL MOVE EASTWARD ACROSS
THE CWA THIS AFTERNOON INTO TONIGHT PROVIDING ENOUGH FORCING WITH
THE SHORTWAVE TROUGH TO PROVIDE A SLIGHT CHANCE OF CONVECTION
ACROSS THE AREA TONIGHT INTO EARLY SUNDAY BEFORE DRIER AIR AND
SUBSIDENCE INCREASES FROM THE WEST ON SUNDAY. RUC13 CONTINUES TO
INDICATE 850MB RELATIVE HUMIDITY INCREASING ACROSS THE RIO GRANDE
VALLEY TODAY AND THIS LIMIT DIURNAL HEATING TO AN EXTENT THIS
AFTERNOON. CLOUD COVER WILL INCREASE THIS AFTERNOON AND CONTINUE
TO INCREASE TONIGHT BEFORE CLEARING FROM WEST TO EAST SUNDAY.
TEMPERATURES WILL BE WARMER SUNDAY THAN TODAY WITH WINDS VEERING
TO THE SOUTH AND THE LACK OF CLOUDS...ESPECIALLY OUT WEST.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...WEAK RIDGING WILL BE
BUILDING AT THE BEGINNING OF NEXT WEEK AS THE LATEST IMPULSE RACES
OFF TO THE EAST. DRIER LOWER LEVELS AND DRY SW FLOW ALOFT WILL
PRECLUDE PRECIPITATION THROUGH WEDNESDAY...WITH TEMPERATURES
GRADUALLY CLIMBING INTO THE MID TO UPPER 90S. THE NEXT LARGE-SCALE
WEATHER SYSTEM DIVES ACROSS THE ROCKIES AND INTO TEXAS WEDNESDAY
EVENING. THIS WILL DRIVE THE NEXT COLD FRONT THROUGH TEXAS
WEDNESDAY NIGHT. MODELS ARE STILL A BIT DIFFERENT ON LOCATING THE
CENTRAL SFC LOW ALONG THE ADVANCING FRONT...BUT ARE SIMILAR IN THE
FINAL TIMING OF THE FRONT. IT IS EXPECTED TO ARRIVE THURSDAY
MORNING...WITH SHOWER AND THUNDERSTORM ACTIVITY. THE FRONT WILL
MOVE THROUGH QUICKLY...WITH ONLY SOME RESIDUAL RAIN CHANCES
POSSIBLE FOR THE IMMEDIATE COASTAL AREAS THURSDAY AFTERNOON. DRIER
AIR WILL MOVE IN QUICKLY IN THE WAKE OF THE FRONT...WITH HIGH
THURSDAY ONLY EXPECTED TO REACH THE UPPER 70S TO LOWER 80S.
MARINE...
TODAY THROUGH SUNDAY...SEAS WERE NEAR 4 FEET WITH SOUTHEAST WINDS
NEAR 14 KNOTS AT BUOY020 EARLY THIS MORNING. MODERATE EAST TO
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY
BEFORE THE PRESSURE GRADIENT WEAKENS ACROSS THE WESTERN GULF OF
MEXICO TONIGHT. LIGHT EAST TO SOUTHEAST WINDS WILL PREVAIL TONIGHT
INTO SUNDAY AS HIGH PRESSURE ACROSS THE SOUTHEAST UNITED STATES
MOVES EASTWARD AND A FRONTAL SYSTEM MOVES INTO THE NORTH CENTRAL
U.S.
MONDAY THROUGH THURSDAY...SOUTHEAST WINDS WILL INCREASE STARTING
MONDAY AS THE SFC HIGH MOVES INTO THE SOUTHEASTERN US AND LOW
PRESSURE DRIFTS INTO THE TEXAS PANHANDLE. GRADIENT REMAINS
TIGHT...SO WINDS OF AT LEAST 15 KNOTS WILL CONTINUE THROUGH
WEDNESDAY. BREEZY CONDITIONS WILL LEAD TO GRADUALLY INCREASING
SEAS...REACHING 5 TO 6 FEET WEDNESDAY. THE NEXT FRONT IS EXPECTED
THURSDAY MORNING...SWITCHING WINDS TO THE NORTH AND INCREASING TO
20 TO 25 KNOTS...WITH SEAS REACHING 8 TO 10 FEET.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55/60
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
623 AM CDT SAT APR 13 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE
MOSTLY MID TO HIGH LEVEL CLOUDS ACROSS THE CWA THIS MORNING.
CEILINGS WERE NEAR 300FT AT KHBV TO NEAR 2100FT AT KAPY. MVFR
CONDITIONS ARE A LOW PROBABILITY EARLY THIS MORNING WITH VFR
AFTER 15Z AS MIXING INCREASES. MVFR CEILINGS WILL LIKELY RETURN TONIGHT AS
LOW LEVEL MOISTURE INCREASES AHEAD OF A 500MB SHORTWAVE TROUGH
APPROACHING FROM THE WEST. ISOLATED SHOWERS MAY DEVELOP ACROSS THE
RIO GRANDE VALLEY TONIGHT WITH PATCHY FOG.
&&
.PREV DISCUSSION... /ISSUED 403 AM CDT SAT APR 13 2013/
SHORT TERM /TODAY THROUGH SUNDAY/...500MB LOW/TROUGH ACROSS
NORTHWEST MEXICO THIS MORNING WILL MOVE EASTWARD ACROSS NORTHERN
MEXICO THIS AFTERNOON AND EASTWARD ACROSS EAST TEXAS SUNDAY. AN
UPPER LEVEL JET ACROSS NORTHERN MEXICO WILL MOVE EASTWARD ACROSS
THE CWA THIS AFTERNOON INTO TONIGHT PROVIDING ENOUGH FORCING WITH
THE SHORTWAVE TROUGH TO PROVIDE A SLIGHT CHANCE OF CONVECTION
ACROSS THE AREA TONIGHT INTO EARLY SUNDAY BEFORE DRIER AIR AND
SUBSIDENCE INCREASES FROM THE WEST ON SUNDAY. RUC13 CONTINUES TO
INDICATE 850MB RELATIVE HUMIDITY INCREASING ACROSS THE RIO GRANDE
VALLEY TODAY AND THIS LIMIT DIURNAL HEATING TO AN EXTENT THIS
AFTERNOON. CLOUD COVER WILL INCREASE THIS AFTERNOON AND CONTINUE
TO INCREASE TONIGHT BEFORE CLEARING FROM WEST TO EAST SUNDAY.
TEMPERATURES WILL BE WARMER SUNDAY THAN TODAY WITH WINDS VEERING
TO THE SOUTH AND THE LACK OF CLOUDS...ESPECIALLY OUT WEST.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...WEAK RIDGING WILL BE
BUILDING AT THE BEGINNING OF NEXT WEEK AS THE LATEST IMPULSE RACES
OFF TO THE EAST. DRIER LOWER LEVELS AND DRY SW FLOW ALOFT WILL
PRECLUDE PRECIPITATION THROUGH WEDNESDAY...WITH TEMPERATURES
GRADUALLY CLIMBING INTO THE MID TO UPPER 90S. THE NEXT LARGE-SCALE
WEATHER SYSTEM DIVES ACROSS THE ROCKIES AND INTO TEXAS WEDNESDAY
EVENING. THIS WILL DRIVE THE NEXT COLD FRONT THROUGH TEXAS
WEDNESDAY NIGHT. MODELS ARE STILL A BIT DIFFERENT ON LOCATING THE
CENTRAL SFC LOW ALONG THE ADVANCING FRONT...BUT ARE SIMILAR IN THE
FINAL TIMING OF THE FRONT. IT IS EXPECTED TO ARRIVE THURSDAY
MORNING...WITH SHOWER AND THUNDERSTORM ACTIVITY. THE FRONT WILL
MOVE THROUGH QUICKLY...WITH ONLY SOME RESIDUAL RAIN CHANCES
POSSIBLE FOR THE IMMEDIATE COASTAL AREAS THURSDAY AFTERNOON. DRIER
AIR WILL MOVE IN QUICKLY IN THE WAKE OF THE FRONT...WITH HIGH
THURSDAY ONLY EXPECTED TO REACH THE UPPER 70S TO LOWER 80S.
MARINE...
TODAY THROUGH SUNDAY...SEAS WERE NEAR 4 FEET WITH SOUTHEAST WINDS
NEAR 14 KNOTS AT BUOY020 EARLY THIS MORNING. MODERATE EAST TO
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY
BEFORE THE PRESSURE GRADIENT WEAKENS ACROSS THE WESTERN GULF OF
MEXICO TONIGHT. LIGHT EAST TO SOUTHEAST WINDS WILL PREVAIL TONIGHT
INTO SUNDAY AS HIGH PRESSURE ACROSS THE SOUTHEAST UNITED STATES
MOVES EASTWARD AND A FRONTAL SYSTEM MOVES INTO THE NORTH CENTRAL
U.S.
MONDAY THROUGH THURSDAY...SOUTHEAST WINDS WILL INCREASE STARTING
MONDAY AS THE SFC HIGH MOVES INTO THE SOUTHEASTERN US AND LOW
PRESSURE DRIFTS INTO THE TEXAS PANHANDLE. GRADIENT REMAINS
TIGHT...SO WINDS OF AT LEAST 15 KNOTS WILL CONTINUE THROUGH
WEDNESDAY. BREEZY CONDITIONS WILL LEAD TO GRADUALLY INCREASING
SEAS...REACHING 5 TO 6 FEET WEDNESDAY. THE NEXT FRONT IS EXPECTED
THURSDAY MORNING...SWITCHING WINDS TO THE NORTH AND INCREASING TO
20 TO 25 KNOTS...WITH SEAS REACHING 8 TO 10 FEET.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
61
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 306 PM CDT SAT APR 13 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
SPINNING OVER SOUTHEAST ONTARIO WHILE A WEAK SURFACE RIDGE AXIS
EXTENDS FROM CENTRAL CANADA TO THE GULF COAST. EMBEDDED SHORTWAVE
TROUGH OVER NORTHWEST WISCONSIN AND STEEP LOW LEVEL LAPSE RATES ARE
CONTRIBUTING TO SCT SNOW SHOWERS OVER NORTHERN AND ALSO CENTRAL
WISCONSIN THIS AFTERNOON...THOUGH BETWEEN THESE AREAS OVER
EAST-CENTRAL WISCONSIN HAVE REMAINED DRY FOR MOST OF THE DAY. THESE
SNOW SHOWERS SHOULD CONTINUE THROUGH EARLY THIS EVENING.
MEANWHILE...THE NEXT STORM SYSTEM IS MOVING OVER THE NORTHERN
ROCKIES AND IS DUE TO IMPACT THE REGION TOMORROW. PRECIPITATION AND
IMPACTS FROM THIS SYSTEM ARE THE MAIN FORECAST CONCERNS.
TONIGHT...SHORTWAVE TROUGH MOVING THROUGH NORTHWEST WISCONSIN WILL
EXIT OVER NORTHERN LAKE MICHIGAN DURING THE EVENING. INCREASING
SUBSIDENCE AND NOCTURNAL COOLING BEHIND THE WAVE WILL END SNOW
SHOWER CHANCES...BUT STILL PLENTY OF CLOUD COVER UPSTREAM WITHIN LOW
LEVEL CONVERGENCE. SO WILL START SKY CONDITIONS AS MOSTLY CLOUDY
BEFORE TRANSITIONING TO PARTLY CLOUDY SKIES AS SURFACE RIDGE AXIS
BUILDS INTO THE REGION. THEN AFTER MIDNIGHT...CLOUDS WILL BE ON THE
INCREASE AS AN 850MB WARM FRONT LIFTS NE ACROSS THE MID-MISSISSIPPI
VALLEY. SOUTHWEST WINDS AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
OVER THE CENTRAL PLAINS WILL ADVECT GULF MOISTURE INTO SOUTHWEST
WISCONSIN BY DAYBREAK. THE INCREASE IN MOISTURE COMBINED WITH
INCREASING FORCING NORTH OF THE WARM FRONT WILL LEAD TO PRECIP
APPROACHING CENTRAL WISCONSIN LATE TONIGHT. PROGGED SOUNDINGS
INDICATE A SNOW/SLEET MIX LOOKS TO BE THE PTYPE AT ARRIVAL. LOW
TEMPS TO OCCUR EARLY OVERNIGHT...BEFORE CLOUDS THICKEN LATE.
SUNDAY...SURFACE LOW PRESSURE WILL MOVE NE ACROSS IOWA AND INTO
SOUTHERN OR CENTRAL MINNESOTA...WHILE THE 850MB WARM FRONT WILL LIFT
NORTH INTO NORTHERN WISCONSIN BY LATE AFTERNOON. 50KTS OF SW FLOW
AT 850MB WILL CAUSE AN FGEN INDUCED BAND OF PRECIPITATION TO LIFT
NORTH OVER THE COURSE OF THE MORNING THROUGH ABOUT MID-AFTERNOON.
ALTHOUGH AIR FROM THE RECEDING HIGH IS NOT AS COLD OR DRY AS THE
EVENT OVER THE PAST WEEK...IT STILL SHOULD BE SUFFICIENTLY COLD FOR
PRECIPITATION TYPE TO BE PREDOMINATELY SNOW AND SLEET FOR THE
MORNING...THOUGH SOME RAIN SHOULD MIX IN WITH THE FROZEN PRECIP BY
LATE MORNING OVER CENTRAL AND EAST-CENTRAL WISCONSIN AS SURFACE
TEMPS WARM. COULD SEE AN INCH OR TWO OF ACCUMULATION OVER CENTRAL
WISCONSIN DURING THE AM HOURS. AS TEMPS WARM FURTHER IN THE
AFTERNOON...PRECIP WILL CHANGE TO ALL RAIN OVER CENTRAL AND
NORTHEAST WISCONSIN...WHILE A MIX OF SNOW/SLEET/RAIN WILL CONTINUE
OVER NORTH-CENTRAL WISCONSIN. NORTH-CENTRAL WISCONSIN COULD ALSO
SEE A COUPLE INCHES OF ACCUMULATION. THOUGH PRECIP RATES COULD BE
BEEFY AT TIMES...AM COUNTING ON DAYTIME HEATING TO SUFFICIENTLY WARM
ROAD TEMPS ENOUGH TO PREVENT WIDESPREAD HAZARDOUS TRAVEL. TEMPS
SHOULD TOP OUT IN THE MID 30S NORTH TO LOW 40S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 306 PM CDT SAT APR 13 2013
UPPER LOW WILL LIFT NORTH ACROSS NORTHERN MINNESOTA SUNDAY NIGHT
AS OCCLUDED SURFACE FRONT MOVES THROUGH AND CAUSES THE RAIN TO
TAPER OFF TO SHOWERS. MONDAY WILL BE BLUSTERY BUT MILD AS 925MB
TEMPERATURES RISE A FEW DEGREES ABOVE FREEZING WITH DECENT MIXING
DESPITE MOSTLY CLOUDY SKIES. WENT A COUPLE OF DEGREES COLDER THAN
MOS GUIDANCE AS THERE WILL STILL BE SNOW ON THE GROUND OVER MUCH
OF THE AREA OR AT LEAST COLD AND WET GROUND. MONDAY NIGHT AND
TUESDAY SHOULD BE MOSTLY DRY AS BIG SURFACE HIGH OVER CANADA TRIES
TO EDGE INTO THE NORTHERN GREAT LAKES. MODELS AGREE THAT A SURFACE
WAVE WILL LIFT NORTH FROM THE SOUTHERN PLAINS TO LOWER MICHIGAN
WEDNESDAY AND WEDNESDAY NIGHT. THE TRACK IS A BIT TOO FAR WEST FOR
SIGNIFICANT SNOW BUT THERE SHOULD BE SOME AT THE START AND END
ESPECIALLY IN THE NORTH. THE SYSTEM IS STILL WAY UPSTREAM SO THAT
COULD CHANGE. MUCH COOLER AIR ARRIVES FRIDAY AND SATURDAY AS THE
SYSTEM GOES BY AND ARCTIC HIGH OVER CENTRAL CANADA MAKES A PUSH
TOWARDS THE SOUTH. SOME INSTABILITY SNOW AND RAIN SHOWERS LIKELY
FRIDAY WITH LAKE ENHANCEMENT IN VILAS COUNTY THURSDAY NIGHT AND
FRIDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1236 PM CDT SAT APR 13 2013
VARIABLE CIGS THIS AFTERNOON UNDER AN UPPER LEVEL LOW
PRESSURE SYSTEM. SOME SCT SNOW SHOWERS CAN BE EXPECTED ACROSS THE
REGION WHICH WILL HAVE POTENTIAL TO DROP VSBYS TO MVFR. SNOW
SHOWERS TO DIMINISH BY EARLY THIS EVENING AND WILL SEE A FEW HOURS
OF CLEARING. THEN A WARM FRONT WILL LIFT QUICKLY TO THE NE LATE
TONIGHT INTO SUNDAY THAT WILL QUICKLY LOWER CIGS AND BRING BACK
PRECIPITATION TO THE REGION BY MID-MORNING. LATEST MODEL SOUNDINGS
INDICATE PRECIPITATION STARTING OUT AS A SNOW/SLEET MIX BEFORE
CHANGING OVER TO RAIN/SLEET BY MIDDAY. CIGS/VSBYS TO APPROACH IFR IN THE
PRECIP.
&&
.HYDROLOGY...
FLOODING CONCERNS HAVE EASED AS COLDER AIR HAS SLOWED THE ONGOING
SNOWMELT. HOWEVER...ANOTHER SYSTEM IS FORECAST TO AFFECT THE
REGION ON SUNDAY AND SUNDAY NIGHT AND PROBABLY RESUME THE RISK OF
RIVER FLOODING AS MORE PCPN FALLS. WL RE-ISSUE THE ESF DETAILING
THE SITN. FLOODING CONCERNS COULD CONT LATER NEXT WEEK...AS YET
ANOTHER SYSTEM TAKES AIM ON NE WI. THERE ARE STILL QUESTIONS AS TO
THE EVENTUAL TRACK OF THE SFC LOW AND WHETHER THE ASSOCIATED PCPN
FALLS AS RAIN OR SNOW.
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
HYDROLOGY......MPC