FXUS61 KCLE 282000
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
300 PM EST SAT NOV 28 2009
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE AREA TONIGHT WILL GIVE WAY TO LOW
PRESSURE THAT WILL TRACK EAST TOWARDS THE AREA ON SUNDAY. THE LOW
PRESSURE AND ASSOCIATED COLD FRONT WILL CROSS THE REGION SUNDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST BEGINNING MONDAY
AND BECOME ESTABLISHED ACROSS THE ENTIRE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
HIGH PRESSURE OVER THE AREA TONIGHT WILL ALLOW FOR CLEAR SKIES WITH
NO SIGNIFICANT WEATHER PROBLEMS. WENT WITH A BLEND OF MAV AND MET
TEMPS ACROSS THE AREA. SOUTHERLY FLOW ALREADY ESTABLISHED ACROSS THE
REGION WILL CONTINUE THROUGH TONIGHT AHEAD OF APPROACHING LOW
PRESSURE. DIDN/T GO WITH TRADITIONAL DIURNAL TEMP PROFILES ACROSS
THE AREA. INITIAL THINKING SUPPORTED BY MOS GUIDANCE SHOWING TEMPS
OUT WEST DROPPING THROUGH THIS EVENING THEN LEVELING OFF LATER
OVERNIGHT WITH AN INCREASE IN DEWPOINTS ADVECTING NORTHEASTWARD.
SOUTHWESTERLY WINDS 5-10KT WILL ALSO HINDER RADIATING CONDITIONS.
FURTHER TO THE EAST THE CHANCES INCREASE FOR DECOUPLING AND
RADIATING ESPECIALLY ACROSS NE OH AND NW PA.
OTHER ITEM THAT WILL NEED SOME ATTENTION THROUGH THIS EVENING IS
FOG/STRATUS ISSUE ACROSS WESTERN ZONES. SOME GUIDANCE INDICATING
POSSIBILITY OF FOG FORMATION THROUGH TONIGHT BUT WITH WINDS KEEPING
UP THINK THAT IF ANYTHING LOW CLOUDS/STRATUS WOULD BE MORE
REASONABLE SOLUTION. MODELS SHOWING PLENTY OF LOW LEVEL MOISTURE
ACROSS WESTERN AREAS LATE TONIGHT. HOWEVER...UPSTREAM OBS THIS
MORNING ACROSS UPPER MIDWEST DIDN/T INDICATE THE FORMATION OF ANY
LOWER CLOUDS OR FOG. FOR NOW JUST INDICATED INCREASING CLOUDS IN
GRIDS ACROSS NORTHWEST OH TOWARDS 12Z SUN. HOWEVER...GIVEN HOW LATE
CLOUDS WILL BE INCREASING WORDING IN ZONES WILL SHOW MOSTLY CLEAR
FOR TONIGHT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
MODELS FAIRLY REASONABLE IN BRINGING COLD FRONT WITH RAIN SHOWERS
THROUGH THE AREA LATE SUNDAY AND SUN NIGHT. INTRODUCED CHC POPS
ACROSS THE AREA TOMORROW AFTERNOON THEN LIKELY FOR NIGHTTIME PERIOD.
PRECIPITATION WITH THE FRONT WILL MAINLY BE RAIN SHOWERS BUT THEN
THICKNESSES AND H850 TEMPS DROP OFF CONSIDERABLY AS UPPER TROUGH
SWINGS THROUGH THE AREA DURING THE DAY MONDAY. AS COLDER AIR ALOFT
BECOMES MORE ESTABLISHED OVER THE AREA CHANGED RAIN SHOWERS OVER TO
A MIX OF RAIN/SNOW...THEN ALL SNOW SHOWERS MONDAY NIGHT. TEMPS
DURING THIS TIME WILL ALSO BE TRICKY AS HIGHS FOR THE DAY MAY BE
EARLIER DURING THE MORNING HOURS...THEN A GRADUAL DROP IN TEMPS
THROUGH THE DAY. THROUGH MONDAY AFTERNOON AND MONDAY NIGHT EXPECTING
MORE SCATTERED PRECIPITATION BEHIND THE FRONT WITH NORTHWESTERLY
FLOW OFF THE LAKE SO FOR NOW INDICATED HIGHER CHANCE POPS FOR MUCH
OF THE AREA. FLOW BECOMES MORE WESTERLY COME TUESDAY WITH HIGH
PRESSURE BEGINNING TO RIDGE BACK INTO THE AREA. WITH
THAT...GRADUALLY CONFINED CHC POPS FOR SNOW SHOWERS MORE ACROSS
FAR NE OH AND NW PA BRINGING AN END TO THE PRECIP.
HIGH PRESSURE RIDGES OVER THE AREA TUESDAY NIGHT ALLOWING FOR A
BREAK IN PRECIPITATION. EXPECTING A MOSTLY DRY DAY ON WEDNESDAY BUT
BOTH GFS AND ECMWF SHOWING UPPER TROUGH DIGGING SOUTHEAST FROM THE
UPPER MIDWEST AND LOW PRESSURE INTENSIFYING OVER THE TENNESSEE
VALLEY. ECMWF TRACKING LOW MORE TO THE EAST COAST ON THURSDAY WHILE
GFS TRYING TO TRACK LOW NORTHWARD OVER OHIO VALLEY. FOR NOW WENT
WITH LOWER CHANCE POPS ACROSS THE AREA WITH GREATEST POPS OVER
SOUTHERN ZONES BY WEDNESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
SYNOPTIC LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE THROUGH THE OHIO
VALLEY THROUGH THE EXTENDED PERIOD. THE GFS AND ECMWF DIFFER ON THE
STORM. THE GFS IS SLIGHTLY STRONGER AND FURTHER EAST THAN THE
ECMWF. THEREFORE THE ECMWF IS SLIGHTLY WARMER THAN THE GFS. THIS
IS SIGNIFICANT SINCE THE GFS INDICATES THE PCPN TYPE COULD BE SNOW
WED NIGHT INTO THURSDAY WHILE THE ECMWF HAS RAIN CHANGING TO SNOW ON
THURSDAY. AT THIS TIME WITH THE UNCERTAINTY...I WILL KEEP A MIX OF
RAIN AND SNOW OVER THE REGION. ALL MODELS BRING MUCH COOLER AIR
OVER THE REGION THURSDAY NIGHT INTO FRIDAY. 850 MB TEMPS BELOW -10C
WILL ADVECT OVER THE LAKES. THIS SHOULD BRING WIDESPREAD LAKE
EFFECT SNOW SHOWERS FOR THE END OF NEXT WEEK.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CLEAR SKIES WILL CONTINUE TO BE THE TREND FOR THE REMAINDER OF THE
AFTERNOON AND EVENING. SC LAYER STILL REMAINS OVER NW PA BUT
SHOULD MOVE EAST BY 20Z. WINDS S-SW WEST AND FAIRLY LIGHT THIS
EVENING. MODELS ARE SUGGESTING SOME LATE NIGHT IFR/MVFR
CONDITIONS...PARTICULARLY OVER THE WESTERN AREAS. MODEL SOUNDINGS
SHOW A LOT OF LOW LEVEL MOISTURE OVER THE AREA BUT WIND FLOW
SHOULD KEEP BOUNDARY LAYER MIXED OVERNIGHT AND SOME HIGH CLOUDS IN
ADVANCE OF THE NEXT FRONT SHOULD ARRIVE BY 12Z. I WILL HINT AT
SOME IFR/MVFR VSBYS TOWARDS 09Z SUN HOWEVER I WILL NOT PRESS IFR
CONDITIONS AT THIS TIME. SOME HIGH MID CLOUDS WILL MOVE THE
REGION SUN IN ADVANCE OF THE FRONT. SOUTH WINDS 10-15 KNOTS MOST
OF THE DAY. I WILL HOLD OFF ON THE MENTION OF ANY PCPN SINCE IT
WILL BE LATE IN THE FORECAST PERIOD.
.OUTLOOK...MVFR SUN NIGHT INTO MONDAY AND EARLY TUE. VFR WILL
RETURN TUE NIGHT INTO WED.
&&
.MARINE...
SOUTHWEST WIND FINALLY DECREASING OVER THE EASTERN SECTIONS OF THE
LAKE. MOST LOCATIONS REPORTING WINDS FROM THE SOUTHWEST LESS THAN
15 KNOTS. I WILL REMOVE THE SMALL CRAFT ADVISORY FOR THE LAKE.
SOUTHWEST WIND WILL CONTINUE OVERNIGHT AS THE HIGH BUILDS INTO THE
REGION. SOUTHWEST WINDS WILL CONTINUE ON SUNDAY AND INCREASE IN
SPEED AS THE COLD FRONT APPROACHES. WINDS WILL SHIFT TO THE W AND
THEN NW SUNDAY NIGHT AS THE FRONT MOVES TO THE EAST. WINDS SPEEDS
WILL INCREASE AS COLD AIR ADVECTION MOVES OVER THE LAKE. SMALL CRAFT
ADVISORIES FOR THE NEARSHORE WILL MOST LIKELY BE NEEDED AGAIN SUNDAY
NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...GARNET
AVIATION...GARNET
MARINE...GARNET
