####018002360#### FXUS63 KTOP 140925 AFDTOP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 325 AM CST SAT FEB 14 2009 .DISCUSSION... EARLY THIS MORNING...SYNOPTIC PATTERN FEATURED A WESTERLY 100KT UPPER LEVEL JET OVER THE CENTRAL PLAINS WITH A SHORTWAVE TROUGH LOCATED OVER THE CENTRAL INTERMOUNTAIN REGION. LOW LEVEL STRATUS WAS CONTINUING TO PUSH SOUTH/EAST THROUGH THE CWA...LEAVING MOSTLY CLEAR SKIES IN ITS WAKE. SCT/BKN MID LEVEL CLOUDINESS WILL OVERSPREAD THE AREA LATER TODAY IN ADVANCE OF THE APPROACHING SHORTWAVE TROUGH. EAST-NORTHEAST WINDS WILL PREVAIL AND CONTINUE THE WEAK CAA...WITH AFTERNOON READINGS REACHING THE LOWER 30S FAR NORTH TO THE LOWER 40S FAR SOUTH. AS THE AFOREMENTIONED TROUGH MOVES THROUGH THE CWA TONIGHT...AN INCREASE IN CLOUD COVER WILL BE NOTED BUT DRY AIR WITHIN THE H8-SFC LAYER SHOULD PROHIBIT PRECIPITATION CHANCES. A GRADUAL WARMUP IS EXPECTED SUNDAY THROUGH TUESDAY AS SFC HIGH PRESSURE SLIDES EAST OF THE CWA...RETURNING SOUTHERLY WINDS BY MONDAY MORNING. A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR BREEZY SOUTHERLY WINDS MONDAY INTO TUESDAY. AFTERNOON HIGHS ON MONDAY WILL REACH THE MIDDLE TO UPPER 40S...WITH HIGHS ON TUESDAY IN THE LOWER 50S TO NEAR 60. WITH THE BREEZY SFC FLOW...WARM TEMPERATURES AND CRITICAL FUELS...A HIGH FIRE DANGER POTENTIAL WILL EXIST ON TUESDAY AFTERNOON...ALBEIT NOT EXPECTED NEAR RED FLAG CRITERIA WITH INCREASING SFC MOISTURE ALLOWING FOR ~30% OR GREATER RH. A SFC LOW WILL MOVE ACROSS THE CWA TUESDAY EVENING DRAGGING A WEAK PACIFIC COLD FRONT THROUGH THE AREA. WITH THE NEAR-SFC LIFT IN ADDITION TO GOOD UPPER SUPPORT...WILL CONTINUE MENTION OF SLIGHT CHANCES FOR RAIN TUESDAY EVENING/NIGHT AS THE SYSTEM QUICKLY MOVES THROUGH. BEST CHANCES FOR PRECIPITATION WITH THIS SYSTEM ATTM LOOK TO BE JUST NORTH OF THE CWA. NO OTHER CHANGES MADE TO THE FAR EXTENDED. BLAIR && .AVIATION... STRATUS CLEARING THE TOP/FOE TERMINALS AT THIS WRITING...ALLOWING VFR CONDITIONS TO RULE THE TAFS. DRYING LOW LAYERS SHOULD KEEP ADDITIONAL CLOUDS LIMITED TO MID/HIGH LAYER WITH THE NEXT WEAK UPPER TROF. NORTH TO NORTHEAST WINDS ARE EXPECTED AS SURFACE LOW PRESSURE DEVELOPS TO THE EAST. 65 && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ####018001597#### FXCA62 TJSJ 140925 AFDSJU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 525 AM AST SAT FEB 14 2009 .DISCUSSION...THE DOPPLER AND SATELLITES IMAGES SHOWED A LIMITED SHOWER ACTIVITY ACROSS THE LOCAL FORECAST AREA THROUGH THE OVERNIGHT HOURS. DRY AND STABLE AIR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH EARLY NEXT WEEK. EXPECT ONLY ISOLATED PASSING SHOWERS MAINLY ACROSS THE EASTERN SECTIONS OF PUERTO RICO AS WELL ACROSS VIEQUES...CULEBRA AND THE U.S. VIRGIN ISLANDS DURING THE NIGHT AND EARLY MORNING HOURS AND ACROSS WESTERN AND INTERIOR SECTIONS OF PUERTO RICO DURING THE AFTERNOONS. A FRONTAL BOUNDARY IS EXPECTED TO MOVE CLOSE TO OUR LOCAL FORECAST AREA TOWARDS THE MID WEEK. THIS FEATURE WILL INCREASE THE CLOUD AND SHOWER COVERAGE ACROSS THE REGION ON TUESDAY AND WEDNESDAY. && .AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE LOCAL FLYING AREA AND ALL LOCAL TAF SITES. NO SIGNIFICANT OPERATIONAL IMPACT IS FORECAST THROUGH SUNDAY. && .MARINE...SEAS AND WINDS WILL CONTINUE TO DECREASE TODAY AND TONIGHT. ON SUNDAY...A MODERATE NORTHERLY SWELL WILL BEGIN TO AFFECT TO LOCAL WATERS. A BIGGER SWELL EVENT IS EXPECTED TO AFFECT THE LOCAL WATERS TUESDAY AND WEDNESDAY. WINDS ARE EXPECTED TO ALSO INCREASE ON TUESDAY...GENERATING CONFUSE SEAS THROUGH AT THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... SJU 84 72 84 72 / 20 20 20 10 STT 83 71 83 71 / 20 20 20 10 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. && $$ 93/10/ ####018003832#### FXUS63 KBIS 140927 AFDBIS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 325 AM CST SAT FEB 14 2009 .SHORT TERM...TODAY THROUGH MONDAY NIGHT... OUR UPPER AIR FLOW WILL TRANSITION FROM NORTHWESTERLY TO MAINLY WESTERLY LATER TODAY INTO MONDAY AS THE NORTHERN EDGE OF THE SOUTHERN JET STREAM SLOWLY ADVANCES INTO CENTRAL NORTH DAKOTA. THE WESTERLY FLOW IS A REFLECTION OF THE NORTHERN AND SOUTHERN STREAM CONSOLIDATING...BUT WILL BEGIN TO SEE THE NORTHERN STREAM PUSH SOUTH AGAIN AS LOWERING HEIGHTS BEGIN TO IMPINGE OVER THE CWA BY MONDAY NIGHT. THE LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE DOMINATING AND REMAINING NEARLY STATIONARY PAST 24HRS STRETCHING FROM ALBERTA TO SASKATCHEWAN AND INTO NORTHERN AND CENTRAL NORTH DAKOTA. THE FOG/STRATUS LOOP SHOWS PATCHY LOW CLOUDS AND SOME FREEZING FOG STRETCHING FROM WILLISTON TO DICKINSON AND SOUTH INTO BOWMAN AND HETTINGER THIS MORNING. EXPECT THIS WILL CONTINUE THROUGH MID MORNING AND PREVIOUS FORECAST GRIDS REFLECTED THIS TREND WELL. A BAROCLINIC ZONE WAS LOCATED OVER CENTRAL/SOUTHERN MONTANA WHICH SNAKED INTO WYOMING AND SOUTHERN SOUTH DAKOTA. THIS BAROCLINIC ZONE WILL GRADUALLY ADVANCE NORTHEAST THROUGH THE SHORT TERM AS THE LEADING EDGE OF A WARM FRONT...BRINGING CLOUDS AND A SLIGHT CHANCE OF SNOW FIRST OVER OUR SOUTHWEST CWA LATER TODAY AND TONIGHT...THEN SPREADING NORTHEAST OVER THE REST OF THE FORECAST AREA SUNDAY INTO MONDAY NIGHT. THE LATEST WATER VAPOR IMAGERY LOOP SHOWS A SHORTWAVE TROUGH STRETCHING FROM OREGON SOUTHEAST INTO NEVADA THIS MORNING. THIS WILL ADVANCE EAST TODAY AND REACH NORTH DAKOTA SUNDAY INTO SUNDAY NIGHT. IN DOING SO A SFC LOW AND AFOREMENTIONED BAROCLINIC ZONE/WARM FRONT WILL BECOME BETTER ORGANIZED TO OUR SOUTH AND SOUTHWEST. PER A BLEND OF THE 00Z GFS AND 00Z ECMWF...ISENTROPIC LIFT NORTH OF THE WARM FRONT WILL BEGIN TO AFFECT SOUTHWEST NORTH DAKOTA LATER THIS AFTERNOON AND TONIGHT BEFORE ADVANCING NORTHEAST SUNDAY INTO SUNDAY NIGHT OVER CENTRAL AND NORTHERN NORTH DAKOTA. THIS WILL AID IN INCREASING THE PROBABILITY OF PRECIPITATION FIELD FROM SLIGHT CHC TO CHANCE. THE ECMWF KEEPS THE LIFT/PRECIP OVER OUR NORTHWEST AND NORTH CENTRAL CWA...WHILE THE GFS IS MORE ROBUST OVER OUR CENTRAL AND NORTHEASTERN CWA. WILL TAKE A BLEND OF THE TWO SOLUTIONS AND INCREASE POPS FROM SLIGHT CHC TONIGHT INTO THE CHC CATEGORY OVER MOST OF THE CWA SUNDAY THROUGH SUNDAY NIGHT. AS THE SHORTWAVE TROUGH ALOFT AND SFC LOW BOTH MIGRATE EAST ON MONDAY POPS WILL DECREASE AGAIN INTO THE SLIGHT CHC CATEGORY. WILL SEE THE POTENTIAL FOR ONE TO TWO INCHES OF SNOW WITH THIS ENTIRE EVENT. HIGH TEMPERATURES WILL REMAIN BELOW NORMAL TODAY AND SUNDAY...THEN INCREASE CLOSER TO NORMAL ON MONDAY WITH THE WARM AIR ADVECTION REACHING ITS PEAK OVER CENTRAL AND SOUTHERN NORTH DAKOTA. .LONG TERM...TUESDAY THROUGH FRIDAY... REMNANTS OF REX BLOCK OFF THE WEST COAST WILL LEAVE GENERALLY LOWER H500 HEIGHTS OVER THE NORTHERN PLAINS IN THE EXTENDED PD. SHORTWAVE TROUGH MOVING THROUGH THE REGION TUESDAY AND TUESDAY NIGHT AND HAVE FOCUSED ON THIS PERIOD FOR SNOW. AFTER THIS...COOLER TEMPERATURES WILL SPREAD INTO THE REGION ON WEDNESDAY INTO THURSDAY. HAVE LOWERED TEMPERATURES WED AND THURS ABOUT 5 TO 10 DEGREES FROM PREV FCST. && .AVIATION...HIGH PRESSURE EXTENDING OVER CENTRAL NORTH DAKOTA WILL BRING VFR CONDITIONS TO ISN...MOT...BIS...AND JMS TODAY. TO THE SOUTHWEST...DIK HAS HAD DENSE FOG SINCE 05Z. I WILL KEEP DENSE FOG IN DIK FOR THE EARLY MORNING PERIOD BECAUSE THERE APPEARS NOTHING TO MOVE THIS OUT. I THINK CONDITIONS WILL IMPROVE TO MVFR CIGS AFTER 12-14Z. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ KS/WAA ####018004338#### FXUS63 KDVN 140929 AFDDVN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 329 AM CST SAT FEB 14 2009 .SYNOPSIS... WAVE THAT BROUGHT SEVERAL INCHES OF SNOW TO PORTIONS OF THE AREA YESTERDAY HAS NOW MOVED EAST LEAVING CHILLY AIR IN IT/S WAKE. HIGH PRESSURE TO BRING QUIET WEATHER THIS WEEKEND THROUGH MONDAY WITH A SLOW WARMING TREND. NEXT POTENT STORM SYSTEM SEEN ON SATELLITE OUT IN THE EASTERN PACIFIC ABOUT 1000 MILES NW OF KLAX. THIS STORM TO IMPACT THE REGION TUESDAY-WEDNESDAY WITH POTENTIAL FOR SIGNIFICANT WINTRY PRECIPITATION AND/OR RAIN DEPENDING ON THE TRACK OF THE CYCLONE. && .SHORT TERM...TODAY AND TONIGHT... SHORT WAVE COMBINED WITH INSTABILITY AND DEEPER MOISTURE THAN EXPECTED BROUGHT YESTERDAY/S HEAVIER CONVECTIVE SNOWFALL. A BAND OF 3-5 INCHES OF SNOW FELL ROUGHLY FROM THE MARENGO/VINTON AREAS THROUGH CEDAR RAPIDS TO THE DUBUQUE/FREEPORT AREAS. THIS SNOW DEPTH WILL PLAY A ROLE IN KEEPING TEMPERATURES AT LEAST SEVERAL DEGREES COLDER THAN SURROUNDING AREAS TODAY AND TONIGHT. IN THIS SNOW BAND WILL FORECAST MAX TEMPS IN THE UPPER 20S WITH REMAINDER OF THE CWA IN THE LOWER TO MID 30S. 850 MB TEMPS PROGGED IN THE -6 TO -8C RANGE TODAY WITH 850 MB TEMPS AS LOW AS -10C TONIGHT. MIN TEMPS TONIGHT SHOULD DROP TO AROUND 10 ABOVE IN THE SNOW BAND WITH TEENS MOST LOCATIONS WITH AROUND 20 IN OUR SE CWA. HOWEVER...THESE READINGS COULD END UP SOMEWHAT LOWER DEPENDING ON HOW MUCH SNOW COVER REMAINS. PLENTY OF LOW CLOUDS OVER THE DVN CWA EARLY THIS MORNING WITH BACK EDGE FROM ABOUT KDSM-KRST WITH AWIPS SPEED TOOL INDICATING CLOUDS MOVING SE AT 15 KNOTS. CLOUDS ERODING FROM THE NW AS DRIER AIR FILTERING SE OUT OF MN AND DAKOTAS AS HIGH PRESSURE BUILDS OUT OF THE DAKOTAS. CLEARING LINE SHOULD REACH EASTERN IA LATER THIS MORNING AND IL EARLY THIS AFTERNOON. ..HAASE.. .LONG TERM...SUNDAY THROUGH NEXT FRIDAY... THE LONG TERM WILL INITIALLY BE QUIET AND COOL AS WE WAIT FOR THE NEXT STRONG WAVE TO MOVE FROM THE WEST COAST AND OUT INTO THE PLAINS BY TUESDAY. THE OVER ALL FORECAST SUNDAY THROUGH MONDAY HAS BEEN CHANGED LITTLE...EXCEPT FOR SLIGHTLY LOWERING HIGHS NORTHWEST SUNDAY AND LOWS MONDAY MORNING DUE TO THE LIKELIHOOD OF GREATER THAN 1 INCH OF REMAINING SNOW PACK. AFTER HIGHS IN THE UPPER 20S TO LOWER 30S SUNDAY...WE SHOULD DROP UNDER LIGHT WINDS AND PARLY TO MOSTLY CLEAR SKIES TO 10 TO 15 OVER SNOW COVER...AND 15 TO 20 ELSEWHERE. MONDAY WILL SEE WINDS BECOME SOUTHERLY AS THE UPPER FLOW BECOMES ZONAL AND SURFACE PRESSURES BEGIN TO FALL IN THE PLAINS. WARM ADVECTION WILL INCREASE LATE IN THE DAY...LIKELY TOO LATER TO GAIN HIGHS MUCH WARMER THAN THE LOWER 30S IN THE NORTHWEST TO UPPER 30S ELSEWHERE. MONDAY NIGHT INCREASING CLOUDS AND SOUTH WINDS WILL HELP KEEP TEMPS UP IN THE MID 20S NORTH TO AROUND 30 SOUTH. THERE IS GOOD MODEL CONSENSUS IN BRINGING A STRONG UPPER WAVE AND SURFACE LOW OVER OR JUST SOUTH OF THE CWA TUESDAY NIGHT AND WEDNESDAY. AT THIS TIME...IT APPEARS WE ARE ON TARGET FOR A GOOD SHOT OF PCPN...LIKELY MAINLY RAIN SOUTH...AND SNOW OR RAIN SNOW MIX NORTH. BY WEDNESDAY ALL AREAS SHOULD CHANGE TO SNOW AS THE SYSTEM PASSES EAST. THIS SYSTEM APPEARS TIGHTLY FOCUSED...AND ANY TREND NORTH OR SOUTH MAY CAUSE PCPN TYPES AND AMOUNTS TO CHANGE SUBSTANTIALLY. HOWEVER...WITH 2 DAYS MODELS RUNS RUNNING THE LOW OVER SOUTHERN IOWA OR NORTHERN MISSOURI...WE ARE GAINING CONFIDENCE THAT THE SYSTEM WILL IMPACT THE DVN CWA WITH EITHER SIGNIFICANT RAIN OR A COMBINATION THAT COULD INCLUDE SIGNIFICANT SNOWFALL AS WELL. NO CHANGES MADE BEYOND WEDNESDAY. THE REMAIDER OF THE PERIOD IS TRENDING COLDER ON THE ECMWF...AND MAY REQUIRE ADDING POPS FOR LIGHT SNOW OR FLURRIES. ...ERVIN... && .AVIATION... MVFR CIGS/VIS WITH LOCAL IFR CIGS THIS MORNING. CLEARING LINE COMING FROM THE NW SHOULD REACH KCID/KDBQ ABOUT 16Z...KMLI/KBRL ABOUT 18Z. VFR CONDITIONS TONIGHT WITH AN INCREASE IN MID AND HIGH LEVEL CLOUDS. ..HAASE.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ HAASE/ERVIN