area forecast discussion  fxus66 khnx 102008  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  108 pm pdt tue jul 10 2007  .discussion...dry lightning event began just before noon over the  high sierra and moisture continues to take aim on central  california. thus far, extensive cloud cover has really squelched  the day time heating and it looks like most lower elevations will  only reach into the lower to mid 90s this afternoon. again the  main forecast concern is the continued threat of dry lightning  from thunderstorms over the very dry mountains of interior central  california. radar shows increasing coverage of cells and this will  likely continue through the afternoon into this evening as the  dynamics arrive from the south. as of 100 pm lightning data shows  cloud to ground rates of 20 per 5 minutes and this does not bode  well for fire concerns.  speaking of dynamics, water vapor  imagery shows the center of vorticity now moving into the la basin  and this is very close to this mornings models. current trajectory  brings the vort center north across central california this  afternoon and evening and then finally into northern california  overnight. an organized area of thunderstorms will likely develop  over the next few hours as afternoon heating combines with the  arriving dynamics. will keep the current scattered to isolated  pops intact for the afternoon package, keeping the chances going  overnight. as stated this morning, for wednesday residual moisture  will allow for another chance of thunderstorms over the mountains  before a drier southwesterly flow takes over for wednesday night  and thursday. on friday night and saturday, the gfs model  continues to project another vorticity center moving up from the  south however this appears to be much weaker than the current one  and moisture looks limited. will not add pops to the forecast  grids at this time as this needs to be looked at this evening in  more detail. for now, emphasis will remain on the short term  thunderstorm dry lightning situation.  &&  .aviation...vfr conditions will prevail through 00z thursday.  however isolated thunderstorms will be possible across tweb routes  through midnight tonight. thunderstorms for the most part will be  high _base_d and and no obstructions to vis or cigs are expected.  for specific details...please refer to the tafs for kmce...kfat  and kbfl...and tweb routes 421 and 423.  &&  .fire weather...isolated to scattered dry thunderstorms will be  possible in the southern sierra nevada...as well as the tehachapi  mountains. a deeper monsoon flow that was expected by this  afternoon has been delayed until later tonight or early wed. thus  have issued red flags for these areas and also included the sierra  foothills until 5am wed.  .air quality issues...  none  &&  .hnx watches/warnings/advisories...  red flag warning until 5 am pdt wednesday for caz293297.  &&   __________________________________________________________________________  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 110443  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  943 pm pdt tue jul 10 2007  .discussion...the monsoonal moisture arrived on schedule and  produced showers and some thunderstorms over the district during  the afternoon and continuing into the evening. one thunderstorm  over yosemite this afternoon prompted a warning...producing nickel  size hail before it weakened and moved north. the increased clouds  helped keep afternoon highs around 6-12 degrees lower than  yesterday. shower activity is continuing over the area...with  some indications of drying from the west as the upper low  elongates just offshore. forecast for tonight looks ok...with  precip lingering into the night and temperatures a couple of  degrees warmer than last night. models continue the drying trend  into tomorrow and convection will likely be confined to the higher  elevations. temperatures should recover that 6-12 degrees lost  toddy...as high pressure begins to rebuild a bit and skies clear  out.  &&  .fire weather...isolated to scattered dry thunderstorms remain  possible in the southern sierra nevada...as well as the tehachapi  mountains. the red flag warning remains in effect until 5am wed.  &&  .aviation...vfr conditions will prevail through 06z thursday.  however isolated thunderstorms will be possible across tweb routes  through around 10z tonight. thunderstorms for the most part will be  high _base_d and no obstructions to vis or cigs are expected. 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...  red flag warning until 5 am pdt wednesday for caz293297.  &&   __________________________________________________________________________  jeb/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 110946  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  246 am pdt wed jul 11 2007  .discussion...  plan to let the red flag warning expire at 5 am due to decreased  coverage of showers and isolated thunderstorms. however another  round of storms is possible...mainly along the crest of the sierra  this afternoon.  upper low off the central ca coast is slowly drifting around out  there and has become more east to west oriented as the main upper  vort lobe has swung through the central ca region and continues to  move nw. the wv imagery indicates plenty of dry air making its way  onshore overnight and will allow for clouds to decrease through  the day today from south to north across the region. the upper low  is expected to weaken and open up and lift north as an approaching  trough of low pressure moves into the pac nw by sunday. the upper  ridge will remain centered over the four corners region and allow  for hot temperatures to return by the weekend.  the remnants of tropical depression 4-e in the east pac has been  sheared apart and the moisture plume is lifting north. the models  do not have a very good handle on this feature and if the plume  makes it over the region today we could cooler temperatures that  forecast. right now we are anticipating the clouds to remain south  and east of the forecast area and do not expect much in the way of  dense cloud cover like that was seen over most of the cwa  yesterday...which cut max temps by as much as 8 degrees from what the  model guidance was expecting.  the forecast trough has some uncertainty with it for the early  part of next week. the gfs seems to be flip flopping on how deep  to make the trough and if another cut off low will develop. have  trended down temps for the extended and kept it dry through day 8.  &&  aviation...isolated thunderstorms are expected to develop during the  afternoon mainly over the higher elevations of the sierra.  otherwise vfr conditions will prevail through 12z thursday. 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...  red flag warning until 5 am pdt early this morning for  caz293297.  &&   __________________________________________________________________________  avn/fw...mv  public...jdb  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 111524  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  824 am pdt wed jul 11 2007  .update...minor update this morning to lower forecast highs and to  trend the thunderstorm threat to this afternoon over the mountains.  &&  .discussion...last of the organized convection is now lifting out  of yosemite and it looks like for the next few hours that the area  will be quiet. yesterday`s vorticity center has lifted up into  oregon as expected leaving central california with a drying, but  still unstable airmass over the sierra. even though the airmass  will be drying, daytime heating and residual moisture should be  enough to spark off some thunderstorms over especially the sierra  from about noon on. expect any thunderstorm that develops to have  sufficient available moisture for precipitation...and not be dry.  by this evening, with the loss of daytime heating convection  should end. thursday should be dry.  &&  .aviation...isolated thunderstorms are expected to develop during    the afternoon mainly over the higher elevations of the sierra.  otherwise vfr conditions will prevail through 18z thursday. 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/mv  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 112129  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  229 pm pdt wed jul 11 2007  .discussion...thus far, thunderstorms have been very isolated and  limited to initiation along and just east of the crest with a  rapid movement to the north. the cumulus field is even limited to  sequoia park northward and it may not develop at all over the  southern sierra and kern county mountains. will opt to limit the  threat this evening to the crest and nowhere else as drier  southwest flow prevails. for tonight it looks clear over the  region. with a rather long fetch of dry air noted on water vapor  imagery, the convective threat for thursday afternoon looks  limited. will opt, _base_d on gfs and the nam models which do  indicate some afternoon instability near yosemite, i will keep  slight chance pops near yosemite. a change in the forecast  thinking now for friday and saturday afternoons as the latest  models bring another surge of moisture in the mid levels up from  the south and into the mountains. will opt to include a slight  chance of afternoon and evening thunderstorms over these areas  both friday and saturday. from sunday through the middle of next  week, a dry southwest flow is progged for the area and the  forecast will remain dry.  as for temperatures, a relatively cool day today in the wake of  the trough lifting north. some marine air has infiltrated the san  joaquin valley and highs this afternoon will just reach into the  lower 90s at best. for thursday through saturday, a slow warming  trend should occur as heights increase and the marine influence in  the san joaquin valley comes to an end. for sunday through the  middle of next week forecast models keep a weak trough across the  west and push the 4 corners high well to the east. the net result  will be temperatures hovering around the century mark in the  warmest places and then falling to the 90s in lower elevations by  mid week.  &&  .aviation...vfr conditions will prevail through 00z friday. 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/bean  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 120440  afdhnx  area forecast discussion  national weather service san joaquin valley - hanford ca  940 pm pdt wed jul 11 2007  .discussion...skies are generally clear across the district as  convection and associated cloudiness continue to push off to the  north and east. just a few clouds along the crest from fresno  county north...and some high clouds streaking across...clipping  extreme northern portions of the district. moderate onshore  surface pressure gradients have developed...producing modest  northwest breezes in the valley. the marine _layer_ is pretty well  mixed out...but the nearby trough will help keep overnight lows a  couple of degrees below last night. the upper low will lift north  and heights will increase slightly tomorrow...bumping afternoon  highs up a bit from readings today...though cooler air lingering  in the valley may temper the warmup there. forecast for tonight  can be updated to remove evening thunderstorms...otherwise looks  ok.  &&  .aviation...vfr conditions will prevail through 06z friday.  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/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.