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Forecast

February 20, 2019/pm report

February 20, 2019

Summary: As of the time of this writing, light showers were moving from northwest to southeast along the Coast Range and the Sierra Nevada with scattered light showers beginning to break out over Merced, San Bernardino, and western Fresno Counties.  The activity over the valley floor was moving southeastward at 35 MPH.

 

The coldest portion of this incoming low is still to our north.  As freezing levels lower during the course of the night, snow will begin falling over the foothills down to possibly as low as 500 feet.  Some snow flakes may even reach the valley floor late tonight and for a time Thursday morning, assuming there is any precipitation left.  The coldest air aloft by sunrise will be over extreme western Nevada into western sections of central California.  By Thursday evening, the low will slide into southern California, continuing snow showers at times over the Kern County mountains into Friday morning.  Snow could fall as low as 1,500 feet, meaning snow could reach the bottom of the Grapevine.

 

By Friday night and Saturday, the low and its very cold air will have moved into Arizona, however there will be a shallow layer of very cold layer for below freezing temperatures Friday and Saturday mornings.  This is discussed below.

 

From late Sunday through the middle of next week, an elongated low will stretch from the Dakotas westward through the Pacific Northwest and several hundred miles off shore.  That is where the active weather will be with showers spreading into northern California from time to time.  For now, though, it looks like the valley will remain dry for a change.  With a nice westerly flow aloft underneath the low, temperatures will get progressively warmer.  Some models are suggesting the valley floor may top 70 degrees by the middle of next week.  This is about 20 to 25 degrees warmer than we’ve been accustomed to.

 

On most models, a ridge of high pressure builds into the Pacific Northwest next Thursday and Friday for a continuation of mild, dry weather.  From next Saturday and through the first week in March, models are still leaning towards periodic waves of low pressure moving from west to east into California underneath a big low off the coast of the Pacific Northwest.  These would be mild systems with much higher snow levels which could potentially add significant precipitation to the region.

 

Forecast:  Partly to mostly cloudy tonight and Thursday morning with scattered, generally light showers.  There is about a 20% chance of snow reaching the valley floor late tonight and for a time Thursday morning.  Becoming partly cloudy Thursday afternoon with snow flurries continuing in the foothills and mountains.  Becoming mostly clear and cold Friday morning through Saturday night.  variable cloudiness Sunday through Wednesday with periods of mostly clear skies.

 

Short Term:                                                                        

Madera 35/51/28/53 Reedley 36/51/29/53 Dinuba 35/50/27/53
Porterville 35/51/28/54 Lindsay 36/51/27/54 Delano 37/51/29/55
Bakersfield 36/50/31/56 Taft 36/50/31/56 Arvin 35/50/29/55
Lamont 37/51/29/56 Pixley 35/51/28/54 Tulare 35/50/27/53
Woodlake 36/51/28/53 Hanford 36/51/29/54 Orosi 35/50/28/54

 

Winds: Winds tonight through Thursday will be mainly out of the northwest at 5 to 15 MPH, diminishing Thursday evening.  Winds will be generally less than 5 MPH after midnight Thursday night with periods of near calm conditions.  Winds Friday and Saturday will be generally at or less than 10 MPH afternoons and evenings and 6 MPH nights and mornings with periods of near calm conditions.

 

Rain:  There is quite a bit of light shower activity over the Coast Range and the Sierra Nevada with showers developing over Merced, Madera, and western Fresno Counties.  All this activity is moving southeastward at 35 MPH.  Periodic light showers, mainly widely scattered, will continue tonight and for a time Thursday morning.  As the freezing level drops during the course of the night, the snow level will drop into the lower foothills surrounding the valley with snow flakes possibly reaching the valley floor during the predawn hours through about nine or ten in the morning.  That’s assuming any precipitation is left on the valley floor.  There is a small chance of isolated showers Thursday afternoon, but most of the activity by then will be over the surrounding mountains.  We have had a small chance of showers late Sunday through Wednesday, but most of the latest modeling information indicates the chance of precipitation will affect only about the northern 1/3 of California, at best.  If this does occur, we should enjoy about a week’s worth of dry weather.  Beginning the first week in March, some models have been pretty consistent in trending towards a big low off the Pacific Northwest with a moist westerly flow moving into California.  Embedded waves of low pressure would result in periods of precipitation from time to time.  This pattern will result in much higher snow levels with the possibility of significant precipitation.

 

Frost Discussion: All locations will be above 32 degrees tonight but near to slightly above in the coldest low lying locations.  Friday and Saturday mornings will see us going right back into a freeze threat.  A very cold pool of air will arrive tonight and Thursday.  With clearing skies Thursday evening, many locations will drop to below freezing Friday morning.  Coldest locations will have the potential of dropping into the 27 to 31 degree range both Friday and Saturday mornings.  Sunday morning will be a turnaround day as, finally, a pattern change will occur.  The westerlies will break through from the Pacific Ocean, resulting in much warmer temperatures as we head into next week.  Some models show the valley topping the 70 degree mark by Wednesday.

 

Next report: Thursday morning/February 21