031 

FXUS66 KMFR 010531

AFDMFR



Area Forecast Discussion

National Weather Service Medford OR

931 PM PST Sat Feb 28 2026



.UPDATED AVIATION AND MARINE DISCUSSION...





.DISCUSSION...A warm front lifting northward across SW Oregon is

producing weak isentropic lift and generating some light rain 

along it early this afternoon. Snow levels are way up there -- 

around 8000-9000 feet. Rainfall has been generally light, with

amounts ranging from a few hundredths to around 0.20 of an inch 

in areas that have had rain. A few spots along the SW Oregon 

coast and western Siskiyou County have had up to 0.25 of an inch. 



Meanwhile, a cut off low is spinning about 600 miles to the WSW of

Brookings currently. Satellite imagery shows the warm front well 

across SW Oregon, with a warm sector to the south across NorCal. 

Lightning has been observed in the warm sector across NW 

California, primarily in Trinity, Humboldt and Mendocino counties,

though also recently as of around noon, Shasta County and Plumas 

County. The warm sector will continue to advance north- 

northeastward this afternoon into this evening and a mid-level 

shortwave disturbance will move through. This will result in some 

healthy showers developing across our NorCal counties 

(Siskiyou/Modoc). Model guidance continues to peg this area as 

having the highest probability of lightning (25-40%) through this 

evening, but there is a slight chance (15-25%) all the way up to 

around the Rogue-Umpqua Divide in southern Oregon (including 

Grants Pass/Medford/Ashland) and also over south-central Oregon 

east of the Cascades as these showers move off to the east- 

northeast. CAMs show MUCAPE of about 250-500 J/KG, which is 

sufficient for lightning, isolated gusty winds and brief

downpours and we can't rule out some small hail either. But, 

parameters don't look impressive enough to be too concerned about 

severe weather. 



The convective activity is being supported by a 100-kt upper 

level jet, which will move off to the east of the area tonight. 

While instability won't go away completely, thunder chances should

diminish after 06Z (10pm). With the low offshore, we'll remain in

diffluent flow aloft, so PoPs will remain high (50-90%) with 

coverage of shower activity highest during Sunday 

afternoon/evening. There is just enough instability for a slight 

chance of thunderstorms then too (15-20%), mainly from NorCal up 

the Cascades (western Klamath County) and over the west side 

(mainly inland from the coast). 



The core of the closed low will move onshore Sunday night, then 

open up into a trough as it heads into the Great Basin on Monday. 

PoPs and coverage of showers should diminish during this time 

period with most areas inland from the coast drying out Monday 

afternoon/evening. We should note that there won't be much of an 

air mass change as this low moves onshore, but snow levels lower 

to around 6000-6500 feet. Shortwave upper ridging moves in Monday

night into Tuesday morning and the drier period will persist 

through Tuesday for inland areas. Rain chances increase along the

coast Tuesday as the next upper trough approaches the PacNW, but 

even there, rain could hold off until the night. Temperatures 

remain mild for early March with highs in the upper 50s/low 60s 

west of the Cascades and 55-60F over the East Side. 



WNW flow aloft will bring a fairly sharp upper trough through the

area Tuesday night into Wednesday. Expect a period of light to 

moderate precipitation to accompany the cold front (all areas - 

70-100% chance) with the focus along the coast and into the 

Cascades. Snow levels will drop during this event, down to 

4000-5000 feet by Wednesday evening, but this will still keep most

winter impacts confined to the higher terrain and Cascade passes.

There is a high 24-hr probability of 4 inches of snow or greater 

(85% chance) at Crater Lake National Park through Wednesday night,

but the probability diminishes to 40% at Lake of the Woods on 

Highway 140. Snowfall rates on Highway 62 south of Crater Lake, 

but also on Highway 230 and 138 around Diamond Lake could reach 1

inch per hour briefly early Wednesday morning. Snow amounts are 

shown to be 3-7 inches above 5000 feet in the Cascades (north of 

Howard Prairie) with higher amounts to 10 inches above 5500 feet. 

Snow amounts farther south in the Siskiyous only look to be an inc

or so. Behind the front, showers probably diminish by Wednesday 

evening for the Rogue Valley (and southeast of the Cascades), but 

onshore flow keeps them going along the coast, to around the 

Rogue-Umpqua Divide and over to the Cascades. Back side energy 

could still bring low chances (15-30%) of showers on Thursday 

across NW sections, with dry weather elsewhere. 



Late next week, recent guidance is showing more solutions favoring

amplification of an upper ridge offshore, which would direct the

best jet-related action to our north. Many ensemble solutions also

show the ridge "flopping over" into the PacNW Friday/Saturday, 

which would keep things largely dry. We've given it a broad-brush

for now given the uncertainty with the highest PoPs remaining 

along the coast and into the Cascades, but lower PoPs (and little 

to no precip) indicated south and east of the Cascades. There is

really no indication of any big precip producers on the horizon. 

-Spilde







&&



.AVIATION...01/06Z TAFS...Isolated to scattered showers will 

continue overnight, then showers will increase on Sunday and chances 

for thunderstorms will develop (10-20%) Sunday afternoon and evening 

(with highest chances inland of the coastal mountains). 



Overnight into Sunday morning, expect areas of MVFR and local 

IFR/LIFR in low clouds and patchy fog in valleys west of the 

Cascades tonight into Sunday morning, including Roseburg and 

Medford. Along the coast, expect widespread MVFR and areas of IFR to 

develop late tonight and Sunday morning, then persist through the 

TAF period. Shower activity will increase Sunday morning and 

afternoon over the area. Conditions will become mainly VFR for 

inland areas Sunday afternoon and evening but local MVFR is possible 

(20-30% chance) with heavier showers.  





&&



.MARINE...Updated 800 PM PST Saturday, February 28, 2026...Winds and 

seas will continue to trend lower tonight. Light south winds and 

relatively calm seas are expected Sunday through Monday night. Then 

winds increase and seas steepen Tuesday into Wednesday as a front 

moves through the area. Steep west seas follows through the end of 

the week, with winds becoming north Friday into next weekend.





&&



.MFR WATCHES/WARNINGS/ADVISORIES...

OR...None.



CA...None.



PACIFIC COASTAL WATERS...None.



&&



$$