Area Forecast Discussion
Issued by NWS Medford, OR
Issued by NWS Medford, OR
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443 FXUS66 KMFR 172332 AFDMFR Area Forecast Discussion National Weather Service Medford OR 432 PM PDT Mon Jun 17 2024 ...New Aviation Section... .AVIATION (00Z TAFs)... Overall, we are looking at a mainly VFR forecast for the terminals; however, there will be a time period overnight where Roseburg (KRBG) could get down to MVFR/IFR. The thought behind this is the recent rainfall/moisture sticking around KRBG and the valley which may lead to low ceilings and/or visibilities. Will have to watch this potential (20%), but confidence was high enough to place a TEMPO group for this MVFR potential. If confidence increase, we will place a "from group" for more persistent conditions. -Guerrero && .PREV DISCUSSION... /Issued 209 PM PDT Mon Jun 17 2024/ SHORT TERM...A trough is swinging across the Pacific Northwest today. More locations west of the Cascades in the valleys and at the coast will see a warm up this afternoon, although temperatures will still be 10 to 15 degrees cooler than normal. A thermal trough has been building today, and this has brought breezy conditions to the coast with gusts near 25 mph possible this afternoon, especially on the Curry County coast. The next area of concern will be tonight with colder overnight temperatures. Tonight there is a 68% probability to reach 32 degrees at Klamath Falls. There is a 65% probability for Chemult to reach 26 degrees or lower tonight. A Freeze Watch was out for tonight with the concern of sub-freezing temperates as low as 24 degrees. This has been upgraded to a Freeze Warning which will be in effect from 1 AM through 8 AM Tuesday. This includes most of Klamath and Lake counties and portions of Siskiyou and Modoc counties near Macdoel and Alturas. Please see the NPWMFR for more information. There was a concern for a Frost Advisory in parts of Siskiyou County, but the probabilities are too low and isolated to bring about another product, so the Freeze Warning will be the only land product tonight. As the trough moves off to the east, higher heights will be present in Oregon on Tuesday, and this will be enough to bring a return to near normal temperatures. Tuesday night into Wednesday morning, temperatures east of the Cascades will be in the mid- /upper 30s, putting an end to the freeze risk in most spots. WEst side valleys will have lows in the mid-/upper 40s. Dry conditions will be favored in the coming days as well. -Hermansen LONG TERM...Wednesday through next Monday (June 19-24, 2024)... Things will start to warm up more Wednesday with a return to temperatures near 90F for the Rogue Valley. The Rogue Valley and western Siskiyou valleys will be under a moderate HeatRisk Wednesday/Thursday afternoons. In addition to the Rogue Valley, moderate HeatRisk will spread into more of the Umpqua Basin and Illinois Valley in the later part of the work week (Thu/Fri). The warmest day of the week will be Friday for west side valleys and Saturday for east side locations. High temperatures will peak in the low/mid 90s for the west side valleys and in the upper 80s to low 90s over the east side. The official forecast for Medford is for 96/95F for both Fri/Sat, respectively, with a low chance (~20%) of 100F. Best chance for >=100F (40-60%) will be in the lower Klamath and Salmon river valleys (Happy Camp/Somes Bar), and the Shasta and Scott valleys of western Siskiyou County. Breezy, but fairly typical, afternoon W-NW winds will be present each day, but will pick up into the weekend, especially east of the Cascades. These areas will have wind speeds of 15-25 mph and occasional gusts to 30 mph both Fri/Sat. A mostly dry front/marine push appears likely over the weekend. As mentioned, Saturday should be another very warm day over inland areas. The front will push onshore Saturday night into Sunday. This could deepen the marine layer just enough for some light rain or drizzle at the coast, especially north of Cape Blanco and perhaps into lower portions of the Umpqua Basin, but right now PoPs are less than 15% in these areas. This trough/front should at least drop temps back by a few degrees both Sun/Mon. Otherwise, dry conditions will prevail through the long term. -Hermansen/Spilde AVIATION...17/18Z TAFs...A large shield of cumulus is sliding down the coast and into the Umpqua Basin this morning. Ceilings within this cumulus are largely VFR, but occasional dips into MVFR are possible. This is especially true along the coast where low-topped showers not seen by radar may be embedded. These clouds should stay bottled up west of the Cascades and north of the Umpqua Divide today, with only pop-up fair weather cumulus elsewhere. Residual moisture may result in the return of stratus and fog in the Umpqua Basin (including KRBG) tonight, similar to this morning. But with the probability remaining relatively low (30% at most), have opted to exclude from their TAF for now. VFR conditions should prevail elsewhere tonight. -Wright MARINE...Updated 200 PM Monday, June 17, 2024...A thermal trough will remain along the coast through at least next weekend, and this will keep north winds and wind driven seas going through the period. Conditions will be worst south of Cape Blanco where winds and seas hazardous to small craft will persist. The thermal trough strengthens and expands northward a bit on Tuesday, and this will bring small craft advisory conditions to the waters north of Cape Blanco as well Tuesday afternoon into Wednesday morning. The thermal trough will strengthen further later this week into the weekend, and this may bring north gales to the waters south of Cape Blanco. Mariners would be wise to stay tuned to updates as we move through the week. -Wright && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Freeze Warning from 1 AM to 8 AM PDT Tuesday for ORZ029>031. CA...Freeze Warning from 1 AM to 8 AM PDT Tuesday for CAZ084-085. PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Friday for PZZ356-376. Small Craft Advisory from 2 PM Tuesday to 5 AM PDT Wednesday for PZZ350-370. && $$