FORECAST DISCUSSION – From The Cal-U Weather Laboratory
Issued: 2035Z FRIDAY, OCTOBER 30, 2009

CURRENTLY AT CAL U WEATHER CENTER THERE ARE PARTLY CLOUDY SKIES WITH THE TEMPERATURE 75F WITH WINDS FROM THE EAST AT 2 MPH.  THE DEWPOINT IS 48F WITH THE PRESSURE FALLING AT 1012 MB. 

UPPER LEVEL ANALYSIS AT 250 MB AT 12Z SHOWS A MERIDONAL PATTERN WITH A TROUGH OVER THE MID-WEST AND A RIDGE IN THE EAST.  THERE IS A 150 KT JET STREAK OVER OK AND NE.  AT THE 500 MB LEVEL THE SAME PATTERN CONTIUNES AS AT 250 MB.  THERE IS A 120 KT JET STREAK OVER NB/IA BOARDER.  AT 700 MB AND 850 MB LEVELS THE TROUGH CONTOURS BECOME CLOSED OFF AND HAVE PROGRESSED EASTWARD.  THE PRESSURE GRADIENTS ARE TIGHT, MAKING THE WINDS STRONG OVER MUCH OF THE TROUGH REGIONS.  ISENTROPIC ANALYSIS SHOWS A MOIST TONGUE REGION OVER MUCH OF THE SE EXTENDING INTO THE GREAT LAKE REGIONS.  UPSLOPING IS ALSO IN THIS MOIST REGION, WITH DOWNSLOPING OVER THE MID-WEST. 

VIS SAT IMAGRY SHOWS SNOW COVER OVER MUCH OF THE ROCKY MOUNTAIN AND CENTRAL PLAINS.  THE OVERALL UPPER LEVEL PATTERN IS CONFIRMED IN VIS AND IR IMAGRY.  IR SHOWS THE COLD FRONT BOUNDARY AND THE HIGH CLOUDS ASSICOIATED WITH THE CONVECTION.  WV SHOWS A DRY SLOT BEHIND THE COLD FRONT, WHICH WILL AID IN WEAKENING THE SYSTEM.  COMPOSITE RADAR CONFIRMS FRONT LOCATION, INDICATING SNOW AND FREEZING RAIN IN THE NORTH CENTRAL CONUS AND RAIN AND THUNDERSTORM ACTIVITY ALONG THE FRONT. 

SURFACE ANALYSIS SHOWS A 984 MB LOW PRESSURE OVER MN AND CANADA BOARDER.  A 1024 MB HIGH PRESSURE OVER NV/CA/OR REGIONS.  THE TIGHT PRESSURE GRADIENT WITH THE LOW PRESSURE BRINGS STEADY GUSTS OVER MUCH OF THE CONUS WITH THE HIGHEST GUST REACHING 45 KT OVER IN.  STREAMLINES AT THE SURFACE CONFIRM THE CONFLUENCE AND DIFLUENCE ASSICIATED WITH THE HIGH AND LOW PRESSURE.  KPIT SKEW-T SHOWS MOIST CONDITIONS UP UNTIL 850 MB AND 450 MB WHERE THERE ARE LOCATOINS OF HYDROLAPSES.  THEN THE CONDITIONS BECOME SATURDATED AGAIN THROUGH THE REST OF THE ATMOSPHERE.  UPSTREAM AT KILN, SHOWS SATURATED CONDITIONS THROUGHOUT THE LEVELS WITH WINDS FROM THE WSW. 

FOR THE WEEKEND, TEMPERATURES SHOULD BE IN THE 50S WITH SHOWERS ENTERING THE FA TONIGHT INTO TOMORROW.  BY SUNDAY THE SYSTEM SHOULD MOVE OUT OF THE AREA.  NEXT WEEK WILL BRING MILD TEMPERATURES AND DRY CONDITIONS. 

NWS ADVISORIES/WATCHES/WARNINGS:  NONE

Prepared by: / REPASI / WELSH / WALKER / NEIDER / WARNICK /
The Cal-U Weather Laboratory