textproduct: Medford

DISCUSSION

Four new daily high temperature records were set and one record was tied Tuesday as the strong ridge settled over northern California and southern Oregon. This ridge will remain unusually strong for this time of year. The Extreme Forecast Index(EFI) is showing widespread values of 1 today and again Friday, suggesting the ECMWF ensemble members are all exceeding the model climatology across the region. The 500 mb heights around 586dm are also in the extremes of climatology for this time of year in northern California. This will result in daytime temperatures pushing 15 to 25 degrees above normal for mid March.

Therefore, we'll break or come very close to breaking records at all our climate sites this afternoon, except for North Bend, as it will be covered in stratus and within the marine layer for part of the day.

Alturas' record of 73 will fall to a high around 80. Mount Shasta City's record of 74 will fall to a high around 83. Montague's record of 77 will probably fall to a high around 81. Medford's record of 80 could be tied or perhaps fall. Klamath Falls' record of 74 will fall to a high around 78. Roseburg's record of 80 could be tied or perhaps fall.

The upper air pattern doesn't change at all heading into Thursday, although troughing in the Pacific will help break down this ridge slightly by Friday. During this time, temperatures will just nudge down a bit in Oregon, although California still seems rather warm during Friday afternoon.

Eventually, a short wave will push through Oregon late Friday night into early Saturday morning. A dry cold front will accompany this short wave and we do have a slight chance of rain over locations west of the Cascades Friday night and Saturday morning. Conditions dry out to the south and east as this front progresses through Oregon.

Ahead of the front, low daytime humidities and gusty winds will lead to enhanced fire weather concerns eats of the Cascades, especially in Lake and eastern Klamath counties, where green up has yet to occur, and much of the fuels are dry. Conditions improve slightly Friday, but will remain a concern.

Temperatures will cool towards more seasonal values this weekend behind the front.

The weather around Tuesday and Wednesday is a little more uncertain. ECMWF ensemble members are showing a low of various strengths deepening in the Gulf of Alaska off the BC coastline. About 15% show a low around 950 to 960 mb while about 20% show 960 to 970mb with the others showing something significantly weaker and a minority showing nothing at all. We feel pretty confident the latest GFS is out to lunch as it much closer to shore compared to the rest of ensemble members. Overall, we'll likely see another cold front or perhaps an occluded front push through late Tuesday and Wednesday. The NBM is predicting probability of precipitation around 70 percent along the coast and 30 percent inland during Tuesday with snow levels dropping rapidly down to 4500 feet on Wednesday. The amount of snow could be nothing to a few inches in the Cascades with the weather mid week.

-Smith/BPN

AVIATION...18/18Z TAFs

VFR conditions will prevail across most of the area through the TAF period. The exception will be along the coast and over the coastal waters where a mix of LIFR and IFR conditions in marine stratus will retreat offshore this afternoon, then return into the coastal valleys early this evening into Thursday morning.

MARINE...Updated 200 PM PDT Wednesday, March 18, 2026

Conditions will remain below advisory levels through Friday evening. A thermal trough develops early Saturday, bringing gusty north winds with gales possible into Sunday, and steep to very steep seas possible into Monday. The outlook is for conditions to briefly improve Monday afternoon and evening, ahead of a cold front with rapidly building seas. Advisory strength winds are likely, and there is a chance of gales on Tuesday. The west swell dominated seas that follow may become high and steep to very steep Tuesday afternoon into Wednesday.

FIRE WEATHER...Updated 200 PM PDT Wednesday, March 18, 2026

An abnormally strong ridge remains in place today and tomorrow, then will retreat as a dry cold front approaches and passes through the area Friday into Saturday.

Under the ridge, very warm conditions continue, with near-record or record daily high temperatures expected again today, with low daytime humidities and moderate recoveries, poor over the ridges.

The mostly dry front approaches the area tomorrow into Friday before passing through the region Friday night into Saturday. This will produce breezy winds across the area, with gusty winds of 25 mph or more eats of the Cascades. These winds, combined with residual low humidities, will produce critical fire weather conditions in fire zones 625 and eastern 624, with dry and breezy conditions expected elsewhere east of the Cascades, including in Modoc and eastern Siskiyou counties. With the abnormally dry conditions, low snowpack, and pre-greenup fuels across the area of concern, a Red Flag Warning has been issued for Thursday afternoon for zones 625 and eastern 624. In these areas, there is a 50 to 70 percent probability of humidities below 15 percent occuring concurrent with wind gusts above 25 mph. These ensembles have a tendency to underestimate winds and overestimate humidities, so those probabilities may actually be higher within the Warning area. Details on the Red Flag Warning can be found in the PDXRFWMFR.

Conditions Friday afternoon will be similar, but slightly improved, although dry humidities and gusty winds are still expected, and will shift slightly east and south from those on Thursday.

Conditions cool to more seasonable values and humidities rise a bit this weekend behind the departing front, then wetter and cooler conditions are possible with a more active pattern by the middle of next week. -BPN

MFR WATCHES/WARNINGS/ADVISORIES

OR...Red Flag Warning from 2 PM to 8 PM PDT Thursday for ORZ624-625.

CA...None.

PACIFIC COASTAL WATERS...None.