North Ops Weather - 2024

[B2A5K6E6R]

From NWCG ~

***** High Risk for Lightning across Eastern PSA’s Sat and Sun*****

• The persistent high pressure ridge will continue to drift slowly eastward allowing marine layer onshore influences return to the coast and coastal valleys. Interior areas however remain very hot and dry running about 5-10 degrees above normal.

• Late in the week moisture moves north up the east side of the state and will combine with a weak upper low off the coast to bring high chances of scattered thunderstorms to the Sierra, N Mtns and the NE mtns Fri through Sun. Best chance for widespread thunderstorms occurs on Sat afternoon and evening across these areas while some uncertainty still exists regarding coverage across the NW mtns.

- Storms during the weekend will likely be quick moving from S-N and are trending on the dry side at least initially Fri/Sat. By Sun instability and moisture shifts eastward with favored areas across Eastern Modoc and the Far Eastside when storms may be little wetter.

- Generally light winds today across most areas west of the Sierra but breezy W winds of 15-25 mph do develop out of the Bay Area/Delta and Shasta Vly late this afternoon/evening. Westerlies pick up this evening across the Crest and Zephyr where gusts of 25-35 mph are anticipated.

• A similar wind pattern from Tue is expected for Wed as well with a little more gusty westerlies showing up along the Coastal Gaps Wed afternoon and evening…gusts of 20-30 mph. Gusty N-NW winds expected down the Shasta Valley Wed afternoon/evening with gusts of 20-35 mph.

• Afternoon mtn cumulus may begin to start showing up each afternoon/evening today through Thu with only very isolated showers and tstorms across the peripheral mtns surrounding the N Vly before activity picks up on Fri.

- Hot temperatures continue through the week and weekend along with very low RH both during the day and overnight across all interior PSAs. The extremely dry airmass will combine with the upcoming lighting, outflow winds and periods of gustier winds. Min RH values of 10-20% and max temps of 95-105 are likely.

[NSilver]

Forecast for Vacaville is return to three days 107 +. RH very low BUT no north wind. It could bring about another flurry of wild fire problems?

[B2A5K6E6R]

From NWCG~

***** High Risk for Wind N Sierras & Far E-side Today, NE CA Fri, & Sac Vly/Foothills Sat *****

***** High Risk for Heat N Sierras Fri *****

***** High Risk for Lightning Far Eastside Fri, N Sierras Sat, and Far E-side & NE CA both Sat & Sun *****

• Prolonged heat wave continues thru Sat except for areas along the immediate coast. Temps E of coastal ranges 10-25F above normal thru Sat. Temps then near normal coastal areas to 5-15F above normal inland next week.

• Marine layer likely to be similar in coverage thru Sat morning w/areas along & near the coast mostly clearing in the afternoons. Increase in marine layer is expected early next week.

- Poor-Mdt RH recoveries at mid-upper elevations, esp in the Sierras, will continue for the remainder of the week w/afternoon RH in the upper single digits to teens most inland valleys.

- Areas of breezy to locally windy westerlies afternoons-evenings, especially NE areas Thu & Fri w/SW gusts 20-30mph. W Sac Valley, Zephyr Wind area NE of Sierras, & N areas near OR border likely to gust 15-25mph most late afternoons to evenings.

• Expect some cumulus build-ups in the Trinity Alps to Mt Shasta area this afternoon-evening & in Lake Tahoe area later Thu, but conditions too dry for lightning.

- Moisture increases Fri bringing initial potential for isolated to scattered mostly dry T-storms w/potential for mdt-strong & gusty outflow winds to the Tahoe area of the N Sierras Fri afternoon-evening w/lesser more isolated potential Far Eastside.

*- Second moisture surge **Sat likely to affect a wider area from the Sierras NE-ward w/widely scattered T-storms.*Additional surge possible Sat-Sat night Sac Valley/Foothills to NW Mtns could bring mainly isolated T-storms there, but signals are currently weak for this feature so continue to monitor.

- T-storm potential Sun mainly in NE areas w/periods of dry & gusty winds early-mid next week.

- Currently, T-storms appear as if they will be high based w/mdt, mostly S-N storm motion, so are likely to be initially dry & then transition to a mix of wet & dry Sat-Sun.

[Flyron]

Northern California forecast: Record-breaking heat possible Thursday

[codagent]

Possible lightning event on Sunday. The GFS has indicated the event the last couple of runs with various amounts of PWAT and CAPE values. However, the NWS Sacramento ADF doesn’t give it much mention and nothing is in stone. I’m just an amateur weather nerd, so I could be wrong, but I think it’s worth mentioning

[23103a]

Euro model definitely shows mountain thunderstorms but not much over lower terrain. It doesn’t look like much rain will fall so that might be an issue after this heatwave. Saturday looks like the busiest day for storms.

[codagent]

Thanks. This is the first time I’ve seen the “Flash density”

[FireAF]

Nws mentioned yesterday storms would be mid to high based and would start out mostly dry with some storms producing a moderate amount of lightning

[anvilhead]

[anvilhead]

The mesoscale models are really upping the thunderstorm potential over the coming days on tonight’s runs. I would expect a mix of both dry and wet thunderstorms if they develop, because the upper level low is deepening and advecting deeper monsoonal moisture at the same time the ridge is weakening. It is not the case that there is so much folding in the upper troposphere from a ‘wrinkle’ in a very strong ridge that would ingest dry air into the thunderstorms from the stratosphere. The dry air is mainly under the boundary layer and will be mixing out, but there could be lightning strikes outside of rain cores with fast storm motion. The dry air as shown on the inverted V profile on soundings suggests storms will not be wet, initially.

Echoing some thoughts I just posted in the Oregon wx… I have significant concern about the next heatwave around the 19th-24th in that it will involve the ridge breaking down and bringing strong onshore winds with extremely hot and dry conditions at the surface, especially the interior. We really have not had a ridge break down this year thus far and are overdue.

“If the GFS verifies… Extreme heat wave coming up around the 19th-24th and possibly thereafter which will bring hot and dry conditions especially east of the Cascades. The gradient in temperature between the interior and coast will promote strong and gusty winds. This could bring an absolutely explosive fire regime to the Cascade crest and points east. This includes WA state. The ECMWF and it’s ensembles are a bit further south with the ridge. Even though relying on the extended GFS (more than 200 hours out) it is important to look at the overall pattern, at some point the ridge has to break down… and there has been run to run consistency. So I am very concerned about this time period.”

[wfapdude]

Something wicked this way comes! Odin, please send the rain! (preferably without lightning bolts OR tornadoes)

[Busy_B_46]

Felt it this am walking out in the Fresno area, had the look had the feel T storms are comin.

[B2A5K6E6R]

From NWCG ~

***** High Risk for Wind Today for NE CA *****

***** High Risk for Wind & Isolated Lightning Threat Sac Valley/Foothills Sat *****

***** High Risk for Lightning Far Eastside, N Sierras, & NE CA both Sat & Sun *****

- SW winds will gust 20-40mph w/RHs in the upper single digits & teens this afternoon-evening across NE CA including NE of Lassen & the Far E-side.

Areas of breezy to locally windy westerlies afternoons-evenings, especially Sierras to Far E-side today & E of Marble Mtns to NE CA Fri w/SW gusts 20-35mph.

• Isolated Dry T-storms possible far SE portions of N Sierras & Far E-side late this afternoon-evening, but passing mid-level clouds w/outflow gusts 25-35 mph.

• Prolonged heat wave continues thru Sat except for areas along the immediate coast. Temps E of coastal ranges 10-25F above normal thru Sat. Temps then near normal coastal areas to 5-15F above normal inland next week.

• Marine layer likely to be similar in coverage thru Sat morning w/areas along & near the coast mostly clearing in the afternoons. Increase in marine layer is expected early next week.

- Poor RH recoveries at mid-upper elevations, esp in the Sierras, will continue for the remainder of the week, become lower, & expand W to Sac Valley to the coastal ranges each night-morning thru Sat w/afternoon RH in the upper single digits to teens most inland valleys.

- Moisture increases Fri bringing initial potential for isolated dry T-storms w/mdt-strong & gusty outflow winds to the Tahoe area & Far E-side Fri afternoon-evening.

- Second moisture surge Sat likely to affect wider area from the Sierras NE-ward w/widely scattered T-storms. Sac Valley/Foothills to NW Mtns could be affected by mainly isolated T-storms Sat-early Sun. Widespread smoke in the area is likely to lessen T-storm development.

Southerly winds increase across the Sac Valley Sat w/gusts 15-35mph surging N in the afternoon-evening along w/RHs upper single digits to teens.

- T-storm potential Sun mainly in NE areas w/periods of dry & gusty winds early-mid next week.

- Currently, T-storms appear as if they will be high based w/mdt, mostly S-N storm motion, so are likely to be initially dry & then transition to a mix of wet & dry Sat-Sun.

[ECF28]

It’s booming just south of Tahoe

[Tybombero]

Considering the dense herbaceous fuel loading, current heat wave and subsequent fuel moistures, I think this is the point where fire season breaks wide open and it’s going to be PL4 for the rest of the year.

[23103a]

And none of the weather stations anywhere in the Sierra show more than .06” of rain today… granted some cells might have heavier rain, but seems like most are not even leaving a wetting rain.

[FireCapt]

Cal Fire just updated their staffing patterns for this - sent via email but stations had to verify over the radio.

Anybody know the staffing?

[Ballofire]

Much rumbling overhead in Reno. Followed by a gutter-flooder.
Didn’t see any downstrikes.
Rain welcome, both to suppress starts and to cool things off…at last.

[Flyron]

California on Fire Watch This Weekend With Dry Lightning Over Sierra Nevada |...

[B2A5K6E6R]

Good morning, today could get very interesting. From NWCG~

***** High Risk for Wind & Isolated Dry Lightning Sac Valley/Foothills Today *****

***** High Risk for Lightning w/Gusty Outflow Winds N Sierras Northeastward Today thru Sun *****

***** High Risk for Lightning Sac Valley/Foothills, Mid Coast to Mendo, & NW Mtns Tonight thru Sun *****

- High confidence in isolated to widely scattered mixed wet & dry T-storms along & near the Sierra Crest N & eastward this afternoon through tonight & lingering Sunday afternoon-evening will bring a high risk of new fire starts. Gusty outflow wind gusts of 30-60mph possible w/stronger cells.

- Poor RH recoverie-s this morning at mid-upper elevations, 10-30% in the Sierras & in the W foothills & mtns surrounding Sac Valley, will shift NW tonight & Sat night Sat resulting in longer burn periods across Mid Coast to Mendo & NW Mtns PSAs.

- Impulse likely to track over the E Bay area-NW Mtns Sat morning thru evening could bring isolated dry lightning to those areas as well as gusty outflow winds.

- Third impulse Sat night into Sun brings an isolated, mostly dry lightning threat w/wind gusts 20-40mph possible to the Sac Valley/Foothills & NW Mtns PSAs.

- Expect increased W-SW winds Sat afternoon-evening thru Sac River Delta & Mt Diablo area, Sac Valley, & E of the Marble Mtns to Shasta Valley w/RHs in teens.

• Prolonged heat wave continues thru Sat except for areas along the immediate coast. Temps E of coastal ranges 10-25F above normal thru Sat. Temps then near normal coastal areas to 5-15F above normal inland next week.

- Marine layer likely to be similar in coverage thru Sat morning w/areas along & near the coast mostly clearing in the afternoons. Increase in marine layer is expected early next week.