Ernesto Remnants

[Trugunzn]

Doesnt look due north at all. Looks like maybe a Chesepeak rider. Also GFSmakes it a Chesepeak rider.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... el_m.shtml

[wxman57]

The intensity of a storm isn't determined by knots but by MPH. MPH is 15% higher than the knot speed. If anything, it definitely is a WELL DEVELOPED tropical depression.....

Intensity is determined by wind speed, which can be measured in knots or mph. The hurricane center actually uses knots, but converts the knots to mph for the general public. 1 knot = 1.15 mph. Any closed circulation of tropical origin with a sustained wind of 39 mph/34 kts, or more is a tropical storm. Observations offshore and on the coast support TS strength, not depression strength.

[Stephanie]

Thanks for the clarification. I've always heard the "general public's" conversion of MPH.

[wxman57]

Here's a noon CDT plot. Wind speeds are in knots. Many land and marine stations reporting 35-45 kts (40-50 mph) sustained winds. This just doesn't make sense. What is going on at NHC?

http://myweb.cableone.net/nolasue/ernesto80.gif

[cycloneye]

wxman57,those strong winds I think are caused by the tight pressure gradient between the high to the north and the low pressure ex Ernesto.

[NFLDART]

I think NHC is done with ernesto

[wxman57]

wxman57,those strong winds I think are caused by the tight pressure gradient between the high to the north and the low pressure ex Ernesto.

It's the pressure gradient that determines the max sustained wind associated with any tropical cyclone. Now there is cooler/drier air flowing into Ernesto from the north, but the main culprit for the stong winds is Ernesto, not the high center. Note that winds across New Jersey to the north are only 20-25 kts.

I think we're going to re-classify Ernesto as a TS this afteroon so that we can put out accurate wind forecasts for clients. We have to define the wind field on a grid. If we put in 45 kt winds, then it's called a TS.

Just can't understand the erratic behavior at the NHC.

[Trugunzn]

This thing is still going EAST:

Way East off NHC track

Still no MET has answered why it is going East the last 6 hours.

[Brent]

Hmmmm. I'm beginning to wonder if this might get back over water and head up towards Long Island.

[Trugunzn]

not to far from the water:

[WxGuy1]

wxman57,those strong winds I think are caused by the tight pressure gradient between the high to the north and the low pressure ex Ernesto.

It's the pressure gradient that determines the max sustained wind associated with any tropical cyclone. Now there is cooler/drier air flowing into Ernesto from the north, but the main culprit for the stong winds is Ernesto, not the high center. Note that winds across New Jersey to the north are only 20-25 kts.

I think we're going to re-classify Ernesto as a TS this afteroon so that we can put out accurate wind forecasts for clients. We have to define the wind field on a grid. If we put in 45 kt winds, then it's called a TS.

Just can't understand the erratic behavior at the NHC.

It's a tough call. If that surface high was not there, would the winds associated with Ernesto be <39mph? So, I asking just about the pressure gradient caused by the low perturbation (i.e. the center of the cyclone) and the ambient, environmental pressure. If you run a weak TD straight into a strong high, you're going to get enhanced pressure gradient and associated winds in the "sandwich zone" between the high and the low/cyclone. However, these winds would be highly, highly asymmetric since they aren't necessarily a function of the cyclone itself -- they exist because of the presence of the cyclone AND the high. For most "normal" tropical cyclones, their winds aren't driven largely because of the interaction between the cyclone and another feature (e.g. a High), but, rather, due to the PGF (and cor. and centr. forces) between the cyclone and the ambient environmental pressure field. Another way of thinking about this -- if a 25kt tropical depression nears an area of already-high winds (say, 20-25kts), does it get upgraded to a TS? If you remove the High, would the grad(P) between the center of the cyclone and some (albeit somewhat arbitrary -- say "average" pressure near 1013mb) "ambient" pressure field of the cyclone caused winds above the TS/TD threshold?

The NHC has been saying for a couple days that strong winds are likely as the cyclone moves northeastward and increases the pressure gradient between it and the high pressure system across the northeastern US.

[Trugunzn]

interesting

[CronkPSU]

so is this headed straight out to sea or going for a noreaster?

[Trugunzn]

I dont know, but if it goes back over water it has a chance to organize again. Im not saying it will.Possible? But i dont. Where are the Mets?

[AnnularCane]

Maybe he will turn around and head to the GOM, sprouting wings in the process.

This is Ernie, after all!

[Stephanie]

Here's a noon CDT plot. Wind speeds are in knots. Many land and marine stations reporting 35-45 kts (40-50 mph) sustained winds. This just doesn't make sense. What is going on at NHC?

http://myweb.cableone.net/nolasue/ernesto80.gif

I don't understand it either. NHC STILL HAS the observations for the Atlantic City airport from around 8:00 am this morning. Did the computers blow up as well?

Ernie is currently in the mouth of the Chesapeake. We have rain right now and the winds are picking up in Atlantic City. So much for going north through NC and Raleigh.

[Derek Ortt]

There are Gale Warnings in effect, which warn for winds of 39-54 m.p.h.

I believe this is the combination of the two features causing these winds. The warnings are in place by the NWS to cover this situation

For the record, I favor Gale and Storm Warnings for tropical storms as well. Would be a good way to delineate between weak TS winds and strong TS winds

[Trugunzn]

looks like its about to go over the water :



Looks like NHC busted on the track

[milfordmawx]

There are Gale Warnings in effect, which warn for winds of 39-54 m.p.h.

There are currently lots of winds greater than 39 at the buoy's in the bay http://www.pdfamily.com/weather/buoy/CHBbuoy.php

[Trugunzn]

.NEAR TERM (TONIGHT AND SATURDAY)...
ERNESTO WILL CONTINUE TO WEAKEN AS IT HEADS NORTHWARD INTO EASTERN
VIRGINIA. HOWEVER...A STRONG 1032 MB HIGH PRESSURE SYSTEM WILL
CONTINUE TO BUILD SOUTHEASTWARD ACROSS NORTHERN NEW ENGLAND. HAVE
GENERALLY FOLLOWED THE GFS SOLUTION...COMPLETELY DISCOUNTING THE NAM.
GIVEN LATEST RADAR AND SATELLITE TRENDS AS WELL AS SURFACE PRESSURE
CHANGE ANALYSES...IT APPEARS THAT THE CENTER OF CIRCULATION WILL
CONTINUE TO HUG THE COAST...AND MAY NOT TURN NORTHWEST. THIS WILL
RESULT IN HIGHER WINDS ACROSS PORTIONS OF CONNECTICUT THAN
PREVIOUSLY EXPECTED...ALONG WITH HIGHER QPF AMOUNTS ACROSS
CONNECTICUT AND LONG ISLAND.
MAIN QUESTIONS FOR TONIGHT AND SATURDAY ARE: 1) WHEN DO ERNESTO'S
RAINS ARRIVE, 2) HOW HEAVY WILL THE RAINS BE, AND 3) HOW WINDY DOES
IT GET IN BETWEEN THE TWO PRESSURE SYSTEMS.

Looks like I wasnt crazy saying that its East of NHC track and close to coast.