area forecast discussion  fxus66 khnx 072201  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  301 pm pdt sat jul 7 2007  .discussion...marine air spilled into the valley overnight and  brought significantly cooler temperatures to the san joaquin  valley and foothills today. temperatures at 2 pm were running 8-13  degrees cooler than 24 hrs ago. cooling in the mountains and  desert was only 0-5 degrees. with the marine _layer_ remaining near  2500 feet deep...some marine air will continue to spill into the  valley tonight. will not see much additional cooling sunday. but  depending on where temperatures finally end up today...the  forecast may be a degree or two too warm for sunday.    the strong upper ridge that has been over the region for the past  few days has weakened slightly. the ridge will remain over the  desert southwest through the week while a weak upper level low  develops off the california coast sunday and remains off the  coast through thursday. an easterly wave will move across mexico  sunday and monday and then move northward through california  monday night and into tuesday. this will draw some monsoonal  moisture northward into southern california monday and into  central california monday night and tuesday. this warm...moist  airmass will bring the potential for thunderstorms over the  mountains and deserts starting monday night and continuing through  wednesday. can not rule out the possibility of nocturnal  thunderstorms...so have not limited them to afternoon and evening  hours. by thursday models are indicating less available  moisture. so any remaining threat of convection will be over the  southern sierra nevada crest thursday then dry on friday.  with only small fluctuations in heights and 850mb temperatures  monday through friday...do not expect to see any significant  warming or cooling trends.  &&  .aviation...vfr conditions will prevail through 00z monday. for  specific details...please refer to the tafs for kmce...kfat and  kbfl...and tweb routes 421 and 423.  &&  .air quality issues...  none  &&  .hnx watches/warnings/advisories...  none.  &&   __________________________________________________________________________  bean/bingham  weather.gov/hanford Boycott Internet Spam:  See <URL:http://spam.abuse.net/spam/ The National Weather Service data is made available courtesy of the National Science Foundation-funded UNIDATA Project and the University of Michigan.

area forecast discussion  fxus66 khnx 080454  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  954 pm pdt sat jul 7 2007  .discussion...an upper trough has weakened the ridge overhead and  pumped up the marine _layer_ to over 2000 feet. this has produced  highs this afternoon around 6 to 12 degrees lower than friday`s  highs and continues to provide temperatures generally 3 to 8  degrees below 24 hrs ago. expect lows tonight a few degrees  lower than last night and then a slight warmup beginning sunday as  the high rebuilds...but no return to the near record highs from  earlier in the week. overnight lows may end up a couple of degrees  below current forecast...otherwise tonight`s forecast looks ok.  &&  .aviation...vfr conditions will prevail through 06z monday. for  specific details...please refer to the tafs for kmce...kfat and  kbfl...and tweb routes 421 and 423.  &&  .air quality issues...  none  &&  .hnx watches/warnings/advisories...  none.  &&   __________________________________________________________________________  jeb/durfee  weather.gov/hanford Boycott Internet Spam:  See <URL:http://spam.abuse.net/spam/ The National Weather Service data is made available courtesy of the National Science Foundation-funded UNIDATA Project and the University of Michigan.

area forecast discussion  fxus66 khnx 080900  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  200 am pdt sun jul 8 2007  .discussion...  the coastal marine _layer_ deepened to around 2300 feet at fort ord    saturday morning...and was still around 2100 feet deep at 0534z.  marine air is spilling through pacheco pass this morning...with  gusts to 38 mph over the san luis reservoir at 0730z...and gusts to  19 kts at the los banos airport /klsn/. this marine air lowered  temperatures in the central and southern san joaquin valley  saturday by 9-11 degrees...breaking the string of 100+ degree days  at many locations.  there are a few forecast concerns this morning. the first is the  winds over the san luis reservoir. winds are currently at lake wind  advisory level...but slowly weakening over the past hour. the models  forecast the winds to subside by 12z and this is supported by the  weakening marine _layer_. will cover the gusty winds with nowcasts as  winds should fall below advisory criteria /sustained speed of 25 mph  for 3 hours/ by 11z. have mentioned local gusts to 35 mph over the  reservoir this morning to allow for model timing uncertainties.  the second concern is temperatures today. in the absence of a  mechanism to scour the marine air from the san joaquin valley...the  pool of marine air will keep temperatures similar to saturday...  with the south end of the valley running cooler. it is likely that  bakersfield will stay in the upper 90s today...and possibly monday  depending on how quickly the marine air mixes out.  concern number 3 is the potential for convection over the mountains  and deserts beginning monday night. the models continue to forecast  the development of an upper level low off the central california  coast  by this afternoon...with the low persisting through midweek  before lifting thursday and merging with an upper-level trough  dropping out of the gulf of alaska. with the low off the coast the  next several days..and the ridge center over the desert southwest...  there will be a southerly flow aloft over california. the gfs does  bring some mid-level monsoonal moisture into california with this  flow...so the current forecast of a slight chance of mountain/desert  thunderstorms monday night through wednesday night looks good. as the  low lifts north thursday...the flow aloft will turn southwest for a  drier airmass. this will end the convective threat for all but the  southern sierra nevada crest. dry weather will return to all areas  next friday and saturday.  temperatures will be slightly above normal through the period. the  dgex and gfs 850-mb temperatures over the hanford warning/forecast  area differ by as much as 3-4 c at times through the period...so  will make only minor changes to the day 3-7 temperatures for local  trending _base_d on day 1-2 adjustments.  &&  .aviation...vfr conditions will prevail through 12z monday. for  specific details...please refer to the tafs for kmce...kfat and  kbfl...and tweb routes 421 and 423.  &&  .air quality issues...  none.  &&  .hnx watches/warnings/advisories...  none.  &&   __________________________________________________________________________  sanger/ds  weather.gov/hanford Boycott Internet Spam:  See <URL:http://spam.abuse.net/spam/ The National Weather Service data is made available courtesy of the National Science Foundation-funded UNIDATA Project and the University of Michigan.

area forecast discussion  fxus66 khnx 081522  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  822 am pdt sun jul 8 2007  .update...have made some minor adjustments to temperatures this  morning _base_d on current trends and local data. rest of forecast  looks fine.  &&  .discussion...little change in the pattern this morning over the  forecast area as a dry southwest flow continues. water vapor  imagery shows a weak shortwave trough moving into california as  the center of high pressure remains over arizona. the net result  today is little change in overall temperatures as heights show  little change. _base_d on morning sounding data from fresno arb and  wind profilers at chowchilla and lost hills, it should be about  2-3 degrees cooler at many san joaquin valley locations and fresno  and bakersfield may not crack 100 degrees. have modified the grids  to reflect this subtle, but notable cooling trend.  &&  .aviation...vfr conditions will prevail through 12z monday. for  specific details...please refer to the tafs for kmce...kfat and  kbfl...and tweb routes 421 and 423.  &&  .air quality issues...  none  &&  .hnx watches/warnings/advisories...  none.  &&   __________________________________________________________________________  dudley/ds  weather.gov/hanford Boycott Internet Spam:  See <URL:http://spam.abuse.net/spam/ The National Weather Service data is made available courtesy of the National Science Foundation-funded UNIDATA Project and the University of Michigan.

area forecast discussion  fxus66 khnx 082119  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  219 pm pdt sun jul 8 2007  .discussion...temperatures continue to trend down 2-4 degrees this  afternoon over most locations. the exception is over merced county  where yesterday`s marine intrusion brought a sizable cool down and  readings are trending sharply up this afternoon. the dry southwest  flow continues over central california and skies are clear. it  appears that even the sierra crest will stay mainly clear this  afternoon. forecast models are in very good agreement in  projecting a pattern on tuesday and wednesday that is very  favorable for thunderstorms in the mountains and deserts as a low  pressure center is progged to form out along 130w while a large  high pressure center remains over arizona and southern nevada.  this set up will indeed combine to turn the mid and upper level  flow to the southeast and this should advect moisture from the  gulf of california into central california. by thursday, the gfs  model shifts the flow to a more southwesterly direction, however  the ecmwf models keeps the flow from the south. this difference is  subtle but important as southwest flow is usually dry and a  southerly flow can go either dry or wet. for the upcoming weekend,  both the gfs and ecmwf models agree in a drier southwest flow  aloft with heights remaining above 590 dm. expect slightly hotter than  normal temperatures but no extremes of heat as experienced this  past week.  &&  .aviation...vfr conditions will prevail through 00z tuesday. for  specific details...please refer to the tafs for kmce...kfat and  kbfl...and tweb routes 421 and 423.  &&  .air quality issues...  none  &&  .hnx watches/warnings/advisories...  none.  &&   __________________________________________________________________________  dudley/bingham  weather.gov/hanford Boycott Internet Spam:  See <URL:http://spam.abuse.net/spam/ The National Weather Service data is made available courtesy of the National Science Foundation-funded UNIDATA Project and the University of Michigan.

area forecast discussion  fxus66 khnx 090431  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  931 pm pdt sun jul 8 2007  .discussion...24 hr temperature trends are generally running up  a few degrees as heights are increasing slightly and the marine  air in place in the valley is gradually modified. the exception is  in the cooler air pooled in the south end of the valley...where  bakersfield is currently running down 2 degrees. expect only a  very slight warmup during the next day or so as an upper low  develops off the central california coast. as our flow aloft turns  southeasterly between the upper low and the high over the desert  southwest...expect sufficient moisture for some convection to  develop in the deserts and mountains monday night through  wednesday night. current forecast looks ok and no update is  planned for tonight.  &&  .aviation...vfr conditions will prevail through 06z tuesday. for  specific details...please refer to the tafs for kmce...kfat and  kbfl...and tweb routes 421 and 423.  &&  .air quality issues...  none  &&  .hnx watches/warnings/advisories...  none.  &&   __________________________________________________________________________  jeb/greiss  weather.gov/hanford Boycott Internet Spam:  See <URL:http://spam.abuse.net/spam/ The National Weather Service data is made available courtesy of the National Science Foundation-funded UNIDATA Project and the University of Michigan.