WxWatcher007 Posted August 18, 2023 Author Share Posted August 18, 2023 I will readily admit I’m out of my depth here. Tracking tropical for the desert southwest is like tracking a blizzard for Miami. 1 4 Link to comment Share on other sites More sharing options...
Kevin Reilly Posted August 18, 2023 Share Posted August 18, 2023 Looking at the water vapor map I would say peak intensity is over the next 24-36 hours then Hilary should move into an awful lot of dry air to the north as it moves in that direction unless it gets pulled up into the moisture evenelope. Link to comment Share on other sites More sharing options...
nycwinter Posted August 18, 2023 Share Posted August 18, 2023 23 minutes ago, WxWatcher007 said: I will readily admit I’m out of my depth here. Tracking tropical for the desert southwest is like tracking a blizzard for Miami. odds of a tropical system into the desert sw is much higher then any blizzard in miami.. Link to comment Share on other sites More sharing options...
nycwinter Posted August 18, 2023 Share Posted August 18, 2023 Just now, nycwinter said: odds of a tropical system into the desert sw is much higher then any blizzard in miami..a blizzard into miami will never happen.. we have had a tropical storm into arizona before.. 2 Link to comment Share on other sites More sharing options...
WxWatcher007 Posted August 18, 2023 Author Share Posted August 18, 2023 14 minutes ago, nycwinter said: Yeah I should have said snow rather than blizzards—that’s happened before. Being dramatic Link to comment Share on other sites More sharing options...
olafminesaw Posted August 18, 2023 Share Posted August 18, 2023 ERC well underway. Seems to be going rather smoothly. 1 Link to comment Share on other sites More sharing options...
Ed, snow and hurricane fan Posted August 18, 2023 Share Posted August 18, 2023 A 50 knot storm near San Diego will cause issues beyond just excessive rainfall Link to comment Share on other sites More sharing options...
olafminesaw Posted August 18, 2023 Share Posted August 18, 2023 Like like a plume of moisture (PRE? Atmospheric river?), could cause flash flooding well before Hillary arrives for the dry side of the divide Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 18, 2023 Share Posted August 18, 2023 Wonder what the navy base in San Diego is thinking right now. 1 Link to comment Share on other sites More sharing options...
WxWatcher007 Posted August 18, 2023 Author Share Posted August 18, 2023 An exceptionally rare D3 high risk now issued. Catastrophic flooding is certainly on the table for some areas of the SW. Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 358 AM EDT Fri Aug 18 2023 Day 3 Valid 12Z Sun Aug 20 2023 - 12Z Mon Aug 21 2023 ...A HIGH RISK OF EXCESSIVE RAINFALL EXISTS FOR THE PENINSULAR RANGES OF SOUTHERN CALIFORNIA... Portions of the West... The guidance is unanimous in merging Hilary with an upper low stuck near central CA. Normally for a tropical cyclone this would be a problem as convective lows would circle the periphery parallel to 1000-500 hPa thickness lines, which would otherwise turn it more north or north-northeast, but since Hilary should be strongly shearing while moving over cold waters and transitioning to a post-tropical or remnant low in the process, it should have diminishing convection in its vicinity, so this isn't the typical model bias (this time). A large area of precipitable water values of 1.75-2.5" will approach if not exceed all-time time records, so there will be moisture to spare. In the Southwest in particular, flow at 750 hPa is expected to reach or exceed 65 kts, so heavy upslope rains on the atypical sides of the southern Sierra Nevada and Peninsula Ranges of CA are anticipated. If the flow is more southerly than expected due to a slightly more westerly track of Hilary, there's a chance that both sides of the Peninsular Range get heavy rainfall. The NAEFS is indicating IVT values 14.8 sigmas above the mean. Even assuming a non-standard distribution, this is extreme. There is a very real potential for 3" amounts in an hour in this environment. Some of the guidance shows local amounts of 7"+, which would be exceeding rare for the region from a tropical cyclone, potentially unique for Nevada. The 100 year ARI is forecast to be exceeded. If a 7"+ maximum materialized over Mount Charleston Sunday into early Monday, it would challenge Nevada's 24 hour rainfall record, set in 2004. Given the overall uniqueness of this event, chose to upgrade to a High Risk for areas near and east of the Peninsular Ranges of Southern CA. Link to comment Share on other sites More sharing options...
olafminesaw Posted August 18, 2023 Share Posted August 18, 2023 6 minutes ago, WxWatcher007 said: An exceptionally rare D3 high risk now issued. Catastrophic flooding is certainly on the table for some areas of the SW. Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 358 AM EDT Fri Aug 18 2023 Day 3 Valid 12Z Sun Aug 20 2023 - 12Z Mon Aug 21 2023 ...A HIGH RISK OF EXCESSIVE RAINFALL EXISTS FOR THE PENINSULAR RANGES OF SOUTHERN CALIFORNIA... Portions of the West... The guidance is unanimous in merging Hilary with an upper low stuck near central CA. Normally for a tropical cyclone this would be a problem as convective lows would circle the periphery parallel to 1000-500 hPa thickness lines, which would otherwise turn it more north or north-northeast, but since Hilary should be strongly shearing while moving over cold waters and transitioning to a post-tropical or remnant low in the process, it should have diminishing convection in its vicinity, so this isn't the typical model bias (this time). A large area of precipitable water values of 1.75-2.5" will approach if not exceed all-time time records, so there will be moisture to spare. In the Southwest in particular, flow at 750 hPa is expected to reach or exceed 65 kts, so heavy upslope rains on the atypical sides of the southern Sierra Nevada and Peninsula Ranges of CA are anticipated. If the flow is more southerly than expected due to a slightly more westerly track of Hilary, there's a chance that both sides of the Peninsular Range get heavy rainfall. The NAEFS is indicating IVT values 14.8 sigmas above the mean. Even assuming a non-standard distribution, this is extreme. There is a very real potential for 3" amounts in an hour in this environment. Some of the guidance shows local amounts of 7"+, which would be exceeding rare for the region from a tropical cyclone, potentially unique for Nevada. The 100 year ARI is forecast to be exceeded. If a 7"+ maximum materialized over Mount Charleston Sunday into early Monday, it would challenge Nevada's 24 hour rainfall record, set in 2004. Given the overall uniqueness of this event, chose to upgrade to a High Risk for areas near and east of the Peninsular Ranges of Southern CA. The San Diego WFO has never been under a day 3 high risk. The last day 1 high risk was Feb 14 2019 1 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 18, 2023 Share Posted August 18, 2023 5 Link to comment Share on other sites More sharing options...
Ed, snow and hurricane fan Posted August 18, 2023 Share Posted August 18, 2023 6 minutes ago, Eskimo Joe said: Positive side of heavy rain in the desert, the resorts around the Salton Sea were abandoned in the 60s and 70s as the lake levels dropped, maybe it will bring back tourism. On the more serious side, I watch engineering disaster shows, and desert highway bridges over arroyos secos have a bad habit of collapsing in the ever more frequent once in a century flood. The stream beds often change course and wash out where protective 'rip rap' wasn't placed. Interstates like 5, 15 and 10, all vital routes, could be closed. Link to comment Share on other sites More sharing options...
NJwx85 Posted August 18, 2023 Share Posted August 18, 2023 3 hours ago, olafminesaw said: ERC well underway. Seems to be going rather smoothly. IR loop shows the eye constricting significantly over the last few hours. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 18, 2023 Share Posted August 18, 2023 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 18, 2023 Share Posted August 18, 2023 4 1 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 18, 2023 Share Posted August 18, 2023 2 Link to comment Share on other sites More sharing options...
KPITSnow Posted August 18, 2023 Share Posted August 18, 2023 There it is. A TS watch in California. The first time ever. 3 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 18, 2023 Share Posted August 18, 2023 Parts of the Imperial Valley are going to top out in the low 110° degree range today for air temperature. In a few days, they're going to get as much as 3 times their annual rainfall. What a wild time to be alive. 5 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 18, 2023 Share Posted August 18, 2023 2 Link to comment Share on other sites More sharing options...
Chinook Posted August 18, 2023 Share Posted August 18, 2023 Look at this huge cloud field! There are new things that happen in weather every day, but a tropical storm getting to San Diego and Los Angeles is something I have not seen. 4 Link to comment Share on other sites More sharing options...
WxWatcher007 Posted August 18, 2023 Author Share Posted August 18, 2023 Recon entering Hilary now. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 18, 2023 Share Posted August 18, 2023 3 minutes ago, WxWatcher007 said: Recon entering Hilary now. You able to do a play by play? Link to comment Share on other sites More sharing options...
SolidIcewx Posted August 18, 2023 Share Posted August 18, 2023 Hot damn this is insane. I’m quite hyped about this storm like I was with Patricia several years ago. Cloud field is definitely massive. Wonder if it will be able to overcome the dry air to an extent Link to comment Share on other sites More sharing options...
NJwx85 Posted August 18, 2023 Share Posted August 18, 2023 IR presentation has improved significantly in the past two hours. Waiting for confirmation but looks like ERC is complete. Link to comment Share on other sites More sharing options...
Ed, snow and hurricane fan Posted August 18, 2023 Share Posted August 18, 2023 Recon data usually updates fairly often on Cowan's Tropical Tidbits page. Looks like the plane has descended to mission altitude. https://www.tropicaltidbits.com/recon/ Link to comment Share on other sites More sharing options...
WxWatcher007 Posted August 18, 2023 Author Share Posted August 18, 2023 8 minutes ago, Eskimo Joe said: You able to do a play by play? Yeah, I’ll do my best. Recon descending in now. Two sites for those that want to follow. Didn’t think I’d be looking at EPAC recon before anything in the Atlantic. https://www.tropicaltidbits.com/recon/#AF300-0109E-HILARY http://tropicaleastpacific.com/recon/recon.cgi?aircraft_page=AF300 1 Link to comment Share on other sites More sharing options...
olafminesaw Posted August 18, 2023 Share Posted August 18, 2023 As much as it's disappointing to have missed the peak, this is vital data in terms of determining how quickly Hilary will regain strength. I suspect it's mixing out a bit of dry air ingested during the ERC and is just now starting to restrengthen, since the ERC completed several hours ago Link to comment Share on other sites More sharing options...
WxWatcher007 Posted August 18, 2023 Author Share Posted August 18, 2023 Recon down to about 10k feet. Entering from the NE quadrant and will likely conduct a NE to SW pass. Link to comment Share on other sites More sharing options...
WxWatcher007 Posted August 18, 2023 Author Share Posted August 18, 2023 Still on approach to the eye. Nothing surprising showing up yet. Spotty data coming in. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now