December 17, 2017
Summary: High pressure in the upper levels of the atmosphere is building into the Pacific Northwest while a fairly well defined low is over northwest Mexico. This has a good shot of cold air riding down from the north into our region, lowering dew points into the mid to upper 20s at most locations. This is generally 3 to 12 degrees lower than 24 hours ago. Wind conditions on the valley floor are also very light as an easterly flow has developed at the surface.
Tonight will be quite cold as a combination of low dew points…the lowest dew points we’ve seen so far this season…and a relatively cold air mass will bring widespread mid to upper 20s, and possibly a tad colder Tuesday morning. More is discussed below in the frost summary.
A strong area of low pressure will move through central California Wednesday. It’s possible a few light showers could occur, especially from Fresno County northward, but the chance remains low and any precip amounts would be very light. Behind this system will be the coldest air of the season so far. For now, it appears low 20s are possible in the coldest unprotected riverbottom and similar locations with widespread mid to upper 20s.
Saturday is when the pattern becomes very interesting as a high builds from southwest to northeast into western Canada with a low possibly developing off the northern and central coast. This configuration would result in a northeasterly flow aloft with modified Arctic air swinging down the west coast. However, if that low positions itself just off shore, cloud cover could possibly come into play, theoretically keeping temperatures up a bit. This low is expected to be somewhere off the west coast Christmas Day and a few days after, but that northeast flow will continue for potentially some very cold nights. If you think this sounds completely different from this morning’s forecast, you are correct as models are now portraying a different scenario this afternoon. Either way, as we move through the week, it appears each morning with the possible exception of Wednesday has the potential of being quite cold with a possible hard freeze Friday and Saturday mornings. With some luck, Thursday might be a bit milder than previously thought due to wind and possible cloud cover.
One model actually shows a chance of showers the day after Christmas, but currently it’s the odd model out. We’ll wait and see what modeling projections show tomorrow morning and see if there’s a need to adjust the forecast once again.
Forecast: Mostly clear with occasional high clouds through Tuesday night. variable cloudiness Wednesday and Wednesday evening with a slight chance of light showers. Clearing Wednesday night. becoming mostly clear Thursday through Friday. Possibly partly cloudy Friday night through Sunday.
Short Term:
| Madera 26/62/26/67 | Reedley 26/62/25/65 | Dinuba 25/61/25/64 | |
| Porterville 26/62/26/66 | Lindsay 25/62/25/66 | Delano 28/63/28/67 | |
| Bakersfield 31/63/32/67 | Arvin 27/64/28/67 | Taft 28/64/31/67 | |
| Lamont 28/64/28/67 | Pixley 26/63/26/67 | Tulare 24/62/25/65 | |
| Woodlake 26/61/26/64 | Hanford 27/63/27/65 | Orosi 25/62/26/66 | |
Winds: Winds will be generally less than 10 MPH with periods of near calm conditions through Tuesday night. Winds Wednesday along the west side will pick up out of the northwest at 15 to 30 MPH with stronger gusts with generally 5 to 15 MPH winds elsewhere. Winds Wednesday night will generally be in the 5 to 15 MPH range with stronger gusts along the west side with light winds elsewhere.
Rain: Expect dry weather for at least the next seven to ten days.
Frost Information: Dew points this afternoon are in the mid to upper 20s south of Madera and near 30 in Madera County. This is anywhere from 3 to as much as 12 degrees lower than 24 hours ago, so as you can see the air mass on the valley floor is once again very dry. In fact, these are some of the lowest dew points we’ve seen so far this early winter season.
Air temperatures are also down and are generally in the mid to upper 50s. Winds are light to near calm at most locations. All of this is ideal for a strong radiational cooling night with widespread mid to upper 20s expected with lows in unprotected low spots in the 22 to 24 degree range. Hillside terrain will generally be in the 29 to 34 degree range.
The inversion tonight will be a bit better than last night but certainly not strong with temperatures at 34 feet anywhere from 3 to 5 degrees warmer at most locations.
Tuesday morning’s conditions will be similar with very little, if any, modifications in the overall atmosphere. Wednesday morning’s conditions will depend on the arrival of clouds ahead of a strong but fairly dry low center. It’s possible we could even see some sprinkles or very light showers Wednesday. If clouds arrive early enough, they would certainly help modify conditions. The challenge for Thursday morning will be the exit time of cloud cover as well as possibly chaotic wind conditions.
If all goes as it looks now, there will be a hard freeze Friday with low 20s in low terrain and mid to upper 20s elsewhere. Conditions for Saturday and Sunday will depend on cloud cover as there is the possibility of a low being off shore, possibly close enough to fling some clouds over the area. Christmas Eve through the 26 and 27 remains very questionable as a completely different set of modeling projections showed up, yet again. They are again showing a big upper high flanked from southwest to northeast from the Pacific Ocean into northwest Canada. What’s really different this afternoon is the fact that a low center could possibly develop off the northern or even central California coast. In theory, this could bring some cloud cover to the region. But what concerns me the most is those northeast winds aloft which could fill the valley with a pool of cold air leading to a significant freeze event.
With different model solutions continuing, it has literally been a day by day forecast with adjustments having to be made each day. For now it appears it will remain that way.
Lows Tonight:
| Terra Bella
25 |
Porterville
26 |
Ivanhoe
27 |
Woodlake
26 |
| Strathmore
26 |
McFarland
25 |
Ducor
26 |
Tea Pot Dome
26 |
| Lindsay
25 |
Exeter
25 |
Famoso
27 |
Madera
26 |
| Belridge
26 |
Delano
28 |
North Bakersfield
27 |
Orosi
25 |
| Orange Cove
26 |
Lindcove
25 |
Lindcove Hillside
30 |
Sanger River Bottom
22 |
| Root Creek
25 |
Venice Hill
27 |
Rosedale
28 |
Jasmine
26 |
| Arvin
27 |
Lamont
28 |
Plainview
26 |
Mettler
29 |
| Edison
27 |
Maricopa
26 |
Holland Creek
29 |
Tivy Valley
26 |
| Kite Road South
28 |
Kite Road North
25 |
Next Report: Monday morning/December 18