Severe Thunderstorm Warning 6, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
120 PM PDT MON JUL 3 2006

.DISCUSSION...12Z NGM/NAM/GFS IN.

THE MARINE STRATUS HAS NOW BURNED OFF TO NEAR THE COAST AND CUMULUS
IS NOW POPPING UP ALONG THE RIDGES EVERYWHERE BUT THE WEST SIDE AND
MODOC COUNTY.

THE 03/12Z MFR SOUNDING CONTINUES THE STABILIZING TREND OF THE PAST
FEW DAYS.  PW IS DOWN TO 1.06 INCHES...THE LI IS NOW -2.0...AND
CAPE HAS DROPPED TO 600 J/KG.

THE SYNOPTIC SCALE PATTERN WILL CHANGE LITTLE THROUGH WEDNESDAY WITH
A LONG WAVE TROUGH NEAR 140W AND AN UPPER HIGH OVER THE FOUR CORNERS
AREA.  SOUTHWEST FLOW ALOFT OVER THE MEDFORD CWA BECOMING SLIGHTLY
MORE SOUTHERLY WHEN EMBEDDED SHORT WAVES PASS OVER.  AT THIS TIME
IT APPEARS THE STRONGEST OF THESE SHORT WAVES WILL PASS THROUGH
TONIGHT.  EXPECT LITTLE CHANGE IN THE WEATHER PATTERN OF THE PAST
FEW DAYS...EXCEPT FOR A GRADUALLY INCREASE IN THE INLAND PENETRATION
OF THE MARINE LAYER IN THE LATE NIGHT AND MORNING HOURS.  WILL
CONTINUE THE SLIGHT CHANCE OF AFTERNOON/EVENING THUNDERSTORMS FROM
THE CASCADES EAST.

A CHANGE IN THE PATTERN WILL OCCUR THURSDAY AND THURSDAY NIGHT WHEN
THE OFFSHORE LONG WAVE TROUGH WILL MOVE ONSHORE.  SOUTHWEST FLOW
ALOFT WILL BE REPLACED BY STRONGER ZONAL FLOW.  THE ASSOCIATED
COLD FRONT WILL MOVE ONSHORE THURSDAY.  NOT BULLISH WITH THE CHANCE
OF PRECIPITATION WITH THIS SYSTEM...500 MB HEIGHTS REMAIN QUITE
HIGH AND CLIMATOLOGY ARGUES STRONGLY AGAINST IT.  EXPECT THE MODELS
TO TREND TOWARD WEAKENING THIS SYSTEM.  HOWEVER...A CHANCE OF
PRECIPITATION IS NOW IN THE FORECAST AND WILL HAVE TO COORDINATE
ANY CHANGES.  A STRONG MARINE PUSH LOOKS LIKELY THOUGH...PUSHING LOW
CLOUDS AND FOG AT LEAST INTO MOST OF THE UMPQUA VALLEY AND MAYBE
THE ROGUE AS WELL.

BY SATURDAY NIGHT...A PATTERN SIMILAR TO THE PRESENT ONE WILL SET
UP...BUT THIS TIME THE OFFSHORE TROUGH WILL BE CLOSER TO THE COAST
AND IT WILL REMAIN PROGRESSIVE...MOVING ONSHORE MONDAY.  AT THIS
TIME...WILL GO WITH A DRY FORECAST AS MONSOONAL MOISTURE WILL
LIKELY BE SHUNTED FARTHER EAST WITH THE STRONGER AND MORE
WESTERLY FLOW ALOFT.  MODEL LIS AND CAPES SUPPORT A DRY FORECAST AS
WELL.

&&

.AVIATION...INLAND...VFR CONDITIONS EXCEPT POSSIBLY NEAR
AFTERNOON/EVENING THUNDERSTORMS FROM THE CASCADES EAST.
COAST...ONSHORE FLOW WILL CONTINUE TO PRODUCE WIDESPREAD MVFR
CONDITIONS WITH AREAS OF IFR PRIMARILY IN THE LATE NIGHT THROUGH
MORNING HOURS.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
&&

STOCKTON